Adrenergic factors regulating cell division in the colonic crypt epithelium during carcinogenesis and in colonic adenoma and adenocarcinoma.

PubMed

Kennedy, M F; Tutton, P J; Barkla, D H

1985-09-01

Evidence exists implicating adrenergic factors in the control of intestinal epithelial cell proliferation in both normal and diseased states. In this report, attention is focussed on changes in the amine requirements of proliferating cells during the chemical induction of tumours in the colon of mouse. Cell proliferation rates were measured stathmokinetically. Tumours were induced by s.c. injection of dimethylhydrazine (DMH). Results with a series of adrenoceptor agonists and antagonists suggest that there is an alpha 2-adrenoceptor mediated excitatory effect in normal colon but an alpha 2 adrenoceptor mediated inhibitory effect in adenoma and carcinoma. Alpha 1 adrenoceptors, on the other hand, have an inhibitory effect in normal crypts and in adenomas, and an excitatory effect in carcinomas. Beta adrenoceptors have an inhibitory effect in the normal and DMH-treated crypt, and in adenomas, but not in carcinomas. In the crypt epithelium of DMH-treated mice, two regions on cell proliferation, with differing regulatory factors, could be identified. In the upper region of the carcinogen-exposed crypt is a zone where cell proliferation is stimulated by an alpha 2 adrenergic mechanism, thus resembling the basal region of the normal crypt. By contrast, in the basal region of these crypts, cell proliferation is stimulated by an alpha 1 mechanism, thus resembling a malignant tumour.

The chemopreventive activity of the histone deacetylase inhibitor tributyrin in colon carcinogenesis involves the induction of apoptosis and reduction of DNA damage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heidor, Renato; Advanced Research Center in Food Science and Nutrition; Furtado, Kelly Silva

2014-04-15

The chemopreventive activity of the histone deacetylase inhibitor (HDACi) tributyrin (TB), a prodrug of butyric acid (BA), was evaluated in a rat model of colon carcinogenesis. The animals were treated with TB (TB group: 200 mg/100 g of body weight, b.w.) or maltodextrin (MD isocaloric control group: 300 mg/100 g b.w.) daily for 9 consecutive weeks. In the 3rd and 4th weeks of treatment, the rats in the TB and MD groups were given DMH (40 mg/kg b.w.) twice a week. After 9 weeks, the animals were euthanized, and the distal colon was examined. Compared with the control group (MDmore » group), TB treatment reduced the total number of aberrant crypt foci (ACF; p < 0.05) as well as the ACF with ≥ 4 crypts (p < 0.05), which are considered more aggressive, but not inhibited the formation of DMH-induced O6-methyldeoxyguanosine DNA adducts. The TB group also showed a higher apoptotic index (p < 0.05) and reduced DNA damage (p < 0.05) compared with MD group. TB acted as a HDACi, as rats treated with the prodrug of BA had higher levels of histone H3K9 acetylation compared with the MD group (p < 0.05). TB administration resulted in increased colonic tissue concentrations of BA (p < 0.05) compared with the control animals. These results suggest that TB can be considered a promising chemopreventive agent for colon carcinogenesis because it reduced the number of ACF, including those that were more aggressive. Induction of apoptosis and reduction of DNA damage are cellular mechanisms that appear to be involved in the chemopreventive activity of TB. - Highlights: • Tributyrin is a chemopreventive agent for rat colon aberrant crypt foci. • Tributyrin increased apoptosis in an experimental rat colon carcinogenesis model. • Tributyrin treatment in a rat colon carcinogenesis model decreased DNA damage. • Tributyrin treatment induced H3K9 acetylation in a rat colon carcinogenesis model.« less

Chemopreventive potential of β-Sitosterol in experimental colon cancer model - an In vitro and In vivo study

PubMed Central

2010-01-01

Background Asclepias curassavica Linn. is a traditional medicinal plant used by tribal people in the western ghats, India, to treat piles, gonorrhoea, roundworm infestation and abdominal tumours. We have determined the protective effect of β-sitosterol isolated from A. curassavica in colon cancer, using in vitro and in vivo models. Methods The active molecule was isolated, based upon bioassay guided fractionation, and identified as β-sitosterol on spectral evidence. The ability to induce apoptosis was determined by its in vitro antiradical activity, cytotoxic studies using human colon adenocarcinoma and normal monkey kidney cell lines, and the expression of β-catenin and proliferating cell nuclear antigen (PCNA) in human colon cancer cell lines (COLO 320 DM). The chemopreventive potential of β-sitosterol in colon carcinogenesis was assessed by injecting 1,2-dimethylhydrazine (DMH, 20 mg/kg b.w.) into male Wistar rats and supplementing this with β-sitosterol throughout the experimental period of 16 weeks at 5, 10, and 20 mg/kg b.w. Results β-sitosterol induced significant dose-dependent growth inhibition of COLO 320 DM cells (IC50 266.2 μM), induced apoptosis by scavenging reactive oxygen species, and suppressed the expression of β-catenin and PCNA antigens in human colon cancer cells. β-sitosterol supplementation reduced the number of aberrant crypt and crypt multiplicity in DMH-initiated rats in a dose-dependent manner with no toxic effects. Conclusion We found doses of 10-20 mg/kg b.w. β-sitosterol to be effective for future in vivo studies. β-sitosterol had chemopreventive potential by virtue of its radical quenching ability in vitro, with minimal toxicity to normal cells. It also attenuated β-catenin and PCNA expression, making it a potential anticancer drug for colon carcinogenesis. PMID:20525330

Foci of aberrant crypts in the colons of mice and rats exposed to carcinogens associated with foods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tudek, B.; Bird, R.P.; Bruce, W.R.

1989-03-01

Aberrant crypt foci can be identified in the colons of rodents treated 3 wk earlier with azoxymethane, a known colon carcinogen. These crypts can easily be visualized in the unsectioned methylene blue-stained colons under light microscopy, where they are distinguished by their increased size, more prominent epithelial cells, and pericryptal space. They occur as single aberrant crypts or as two, three, or four aberrant crypts in a cluster. We compared the reported ability of carcinogens associated with the human diet to induce colon cancer with the measured rate of induction of aberrant crypts in female CF1 mice and Sprague-Dawley rats.more » The carcinogens used were 1,2-dimethylhydrazine, methyl nitrosourea, N-nitrosodimethylamine, benzo(a)pyrene, aflatoxin B1, 2-amino-6-methyldipyrido(1,2-alpha:3',2'-d)imidazole, 2-amino-3-methylimidazo(4,5-P)quinoline, 2-amino-3,4-dimethylimidazo(4,5-P)quinoline, and 3-amino-1-methyl-5H-pyrido(4,3-b)indole. Graded doses of these compounds were given to the animals by gavage twice with a 4-day interval, and the animals were terminated 3 wk later. All colon carcinogens induced aberrant crypts in a dose-related fashion. N-Nitrosodimethylamine and 3-amino-1-methyl-5H-pyrido(4,3-b)indole, carcinogenic compounds that do not induce colon cancer, did not induce them. The ability of the studied compounds to induce aberrant crypts was species specific; e.g., aflatoxin B1 and 2-amino-3,4-dimethylimidazo(4,5-P)quinoline induce about 20 times more in rats than mice. This relationship was consistent with their reported ability to induce colon cancer in these species. Results of the present study support the use of the aberrant crypt assays to screen colon-specific carcinogens and to study the process of colon carcinogenesis.« less

Effect of complex polyphenols on colon carcinogenesis.

PubMed

Caderni, G; Remy, S; Cheynier, V; Morozzi, G; Dolara, P

1999-06-01

Complex polyphenols and tannins from wine (WCPT) are being considered increasingly as potential cancer chemopreventive agents, since epidemiological studies suggest that populations consuming a high amount of polyphenols in the diet may have a lower incidence of some types of cancer. We studied the effect of WCPT on a series of parameters related to colon carcinogenesis in rats. WCPT were administered to F344 rats at a dose of 14 or 57 mg/kg/d, mixed with the diet. The higher dose is about ten times the exposure to polyphenols of a moderate drinker of red wine. In rats treated with WCPT, we measured fecal bile acids and long chain fatty acids, colon mucosa cell proliferation, apoptosis and, after administration of colon carcinogens, the number and size of aberrant crypt foci (ACF) and nuclear aberrations. Colon mucosa proliferation was not varied by chronic administration (90 d) of WCPT (14 or 57 mg/kg/d). The highest dose of WCPT decreased the number of cells in the colon crypts, but did not increase apoptosis. WCPT (57 mg/kg) administered before or after the administration of azoxymethane (AOM) did not vary the number or multiplicity of ACF in the colon. The number of nuclear aberrations (NA) in colon mucosa was studied after administration of 1,2-dimethylhydrazine (DMH) and 2-amino-3-methylimidazo (4,5-f)quinoline (IQ), colon-specific carcinogens which require metabolic activation. The effect of DMH and IQ was not varied by pre-feeding WCPT (57 mg/kg) for 10 d. Similarly, the levels of total, secondary bile acids and long chain fatty acids did not varied significantly in animals fed WCPT for 90 d. WCPT administration does not influence parameters related to colon carcinogenesis in the rat.

Inhibitory effects of crude alpha-mangostin, a xanthone derivative, on two different categories of colon preneoplastic lesions induced by 1, 2-dimethylhydrazine in the rat.

PubMed

Nabandith, Viengvansay; Suzui, Masumi; Morioka, Takamitsu; Kaneshiro, Tatsuya; Kinjo, Tatsuya; Matsumoto, Kenji; Akao, Yukihiro; Iinuma, Munekazu; Yoshimi, Naoki

2004-01-01

The purpose of this study was to examine whether crude alpha-mangostin (a major xanthone derivative in mangosteen pericarp (Garcinia mangostana)) has short-term chemopreventive effects on putative preneoplastic lesions involved in rat colon carcinogenesis. The crude preparation was obtained by simple recrystallization of an ethylacetate extract of mangosteen pericarps. A total of 33 five-week-old male F344 rats were randomly divided into 5 experimental groups. Rats in groups 1-3 were given a subcutaneous injection of 1,2-dimethylhydrazine (DMH)(40 mg/kg body weight) once a week for 2 weeks. Starting one week before the first injection of DMH, rats in groups 2 and 3 were fed a diet containing 0.02% and 0.05% crude alpha-mangostin, respectively, for 5 weeks. Rats in group 4 also received the diet containing 0.05% crude alpha-mangostin, while rats in group 5 served as untreated controls. The experiment was terminated 5 weeks after the start. Dietary administration of crude alpha-mangostin at both doses significantly inhibited the induction and/or development of aberrant crypt foci (ACF) (P<0.05 for 0.02% crude alpha-mangostin, P<0.01 for 0.05% crude alpha-mangostin), when compared to the DMH-treated group (group 1). Moreover, treatment of rats with 0.05% crude alpha-mangostin significantly decreased dysplastic foci (DF) (P<0.05) and beta-catenin accumulated crypts (BCAC) (P<0.05), to below the group 1 values. The proliferating cell nuclear antigen (PCNA) labeling indices of colon epithelium and focal lesions in groups 2 and 3 were also significantly lower than in group 1 and this effect occurred in a dose dependent manner of the crude alpha-mangostin. This finding that crude alpha-mangostin has potent chemopreventive effects in our short-term colon carcinogenesis bioassay system suggests that longer exposure might result in suppression of tumor development.

Impact of Novel Prebiotic Galacto-Oligosaccharides on Various Biomarkers of Colorectal Cancer in Wister Rats.

PubMed

Qamar, Tahir Rasool; Iqbal, Sanaullah; Syed, Fatima; Nasir, Muhammad; Rehman, Habib; Iqbal, Muhammad Aamir; Liu, Rui Hai

2017-08-31

Colorectal cancer (CRC) is one of the leading causes of cancer deaths around the globe. Bioactive food ingredients such as prebiotics have protective potential in colon cancer. Data on galacto-oligosaccharides (GalOS) against CRC are very limited and GalOS used in this study have β-1,6 and β-1,3 as major glycosidic linkages and, to our best knowledge, were never used before against any cancer treatment. This study aims to investigate the protective role of novel GalOS against various biomarkers of CRC including aberrant crypt foci (ACF), bacterial enzymes and short chain fatty acids (SCFA) in a rodent model induced with 1,2-dimethylhydrazine dihydrochloride (DMH). Inulin group was taken as positive control in present study to compare novel GalOS protective effects. GalOS doses of 76-151 mg and inulin doses of 114 mg were given to different groups treated with DMH. Results showed that ACF formation was significantly ( p ≤ 0.05) less in high dose GalOS group (27.3%). GalOS also had protective effects against DMH-induced body weight loss and showed higher level of cecal and fecal SCFA (acetate, propionate and butyrate). High doses of GalOS also resulted in significant ( p ≤ 0.05) reduction of bacterial enzymatic activities. Increased populations of beneficial bacteria (bifidobacteria and lactobacilli) and decreased concentrations of harmful bacteria were observed in all prebiotics treatment groups. It can be concluded that novel GalOS exhibit robust protective activity against ACF formation in vivo.

The influence of dibutyryl adenosine cyclic monophosphate on cell proliferation in the epithelium of the jejunal crypts, the colonic crypts and in colonic carcinomata of rat.

PubMed

Tutton, P J; Barkla, D H

1980-01-01

1. Cell proliferation in the jejunal crypts, the colonic crypts and in dimethylhydrazine (DMH)-induced adenocarcinomata of rat colon was measured using a stathmokinetic technique. 2. Dibutryl cyclic adneosine monophosphate (dibutyryl cAMP) was found to inhibit cell proliferation in colonic crypts and in colonic adenocarcinomata. 3. Dibutryl cAMP at very high doses was found to inhibit jejunal crypt cell proliferation but at lower doses was found to accelerate jejunal crypt cell proliferation. 4. Neither bilateral adrenalectomy nor chemical sympathectomy was found to abolish the ability of dibutryl cAMP to stimulate jejunal crypt cell proliferation. 5. The present results are difficult to interpret in terms of known hormonal influences on cell proliferation in the tissues examined and of established actions, of these hormones on cyclic nucleotide metabolism in other tissues.

Chemopreventive effect of Cynodon dactylon (L.) Pers. extract against DMH-induced colon carcinogenesis in experimental animals.

PubMed

Albert-Baskar, Arul; Ignacimuthu, Savarimuthu

2010-07-01

The present study was aimed at evaluating the chemopreventive property of Cynodon dactylon. The antioxidant, antiproliferative and apoptotic potentials of the plant were investigated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, nitric oxide radical scavenging activity (NO(-)) and MTT assay on four cancer cell lines (COLO 320 DM, MCH-7, AGS, A549) and a normal cell line (VERO). In vivo chemopreventive property of the plant extract was studied in DMH-induced colon carcinogenesis. The methanolic extract of C. dactylon was found to be antiproliferative and antioxidative at lower concentrations and induced apoptotic cell death in COLO 320 DM cells. Treatment with methanolic extract of C. dactylon increased the levels of antioxidant enzymes and reduced the number of dysplastic crypts in DMH-induced colon of albino rats. The present investigation revealed the anticancer potential of methanolic extract of C. dactylon in COLO 320 DM cells and experimentally induced colon carcinogenesis in rats.

Lactobacillus salivarius Ren prevent the early colorectal carcinogenesis in 1, 2-dimethylhydrazine-induced rat model.

PubMed

Zhu, J; Zhu, C; Ge, S; Zhang, M; Jiang, L; Cui, J; Ren, F

2014-07-01

The objective of this study was to investigate the impact of Lactobacillus salivarius Ren (LS) on modulating colonic micro flora structure and influencing host colonic health in a rat model with colorectal precancerous lesions. Male F344 rats were injected with 1, 2-dimethylhydrazine (DMH) and treated with LS of two doses (5 × 10(8) and 1 × 10(10) CFU kg(-1) body weight) for 15 weeks. The colonic microflora profiles, luminal metabolites, epithelial proliferation and precancerous lesions [aberrant crypt foci (ACF)] were determined. A distinct segregation of colonic microflora structures was observed in LS-treated group. The abundance of one Prevotella-related strain was increased, and the abundance of one Bacillus-related strain was decreased by LS treatment. These changes were accompanied by increased short-chain fatty acid levels and decreased azoreductase activity. LS treatment also reduced the number of ACF by c. 40% and suppressed epithelial proliferation. Lactobacillus salivarius Ren improved the colonic microflora structures and the luminal metabolisms in addition preventing the early colorectal carcinogenesis in DMH-induced rat model. Colonic microflora is an important factor in colorectal carcinogenesis. Modulating the structural shifts of microflora may provide a novel option for preventing colorectal carcinogenesis. This study suggested a potential probiotic-based approach to modulate the intestinal microflora in the prevention of colorectal carcinogenesis. © 2014 The Society for Applied Microbiology.

Prevention of DNA damage and anticarcinogenic activity of Activia® in a preclinical model.

PubMed

Limeiras, S M A; Ogo, F M; Genez, L A L; Carreira, C M; Oliveira, E J T; Pessatto, L R; Neves, S C; Pesarini, J R; Schweich, L C; Silva, R A; Cantero, W B; Antoniolli-Silva, A C M B; Oliveira, R J

2017-03-22

Colorectal cancer is a global public health issue. Studies have pointed to the protective effect of probiotics on colorectal carcinogenesis. Activia ® is a lacto probiotic product that is widely consumed all over the world and its beneficial properties are related, mainly, to the lineage of traditional yoghurt bacteria combined with a specific bacillus, DanRegularis, which gives the product a proven capacity to intestinal regulation in humans. The aim of this study was to evaluate the antigenotoxic, antimutagenic, and anticarcinogenic proprieties of the Activia product, in response to damage caused by 1,2-dimethylhydrazine (DMH) in Swiss mice. Activia does not have shown antigenotoxic activity. However, the percent of DNA damage reduction, evaluated by the antimutagenicity assay, ranged from 69.23 to 96.15% indicating effective chemopreventive action. Activia reduced up to 79.82% the induction of aberrant crypt foci by DMH. Facing the results, it is inferred that Activia facilitates the weight loss, prevents DNA damage and pre-cancerous lesions in the intestinal mucosa.

Combination of curcumin and green tea catechins prevents dimethylhydrazine-induced colon carcinogenesis.

PubMed

Xu, Gang; Ren, Guijie; Xu, Xia; Yuan, Huiqing; Wang, Zhenzheng; Kang, Ludong; Yu, Wenguang; Tian, Keli

2010-01-01

The chemopreventive effects of curcumin and green tea catechins individually and in combination on 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis were studied in male Wister rats following 32 weeks of dietary treatment. The incidence, number and size of colorectal cancer were measured. Colorectal aberrant crypt foci (ACF) were analyzed by methylene blue staining. Proliferation indices and apoptotic indices were determined by PCNA immunostaining and TUNEL assay, respectively. The results showed that dietary curcumin, catechins and combination administration significantly inhibited the total number of ACF per rat. The combination treatment displayed the most potent inhibitory effect, while there was no difference of inhibition between curcumin and catechins-treated groups. The incidence of colorectal cancer in the treated groups was significantly lower than that of positive control group. Compared with the positive control group, the proliferation index was significantly decreased and the apoptotic index was significantly increased in all treatment groups, while the effect of the combination was the greatest among the treated groups. Our findings suggest that the combination of curcumin and catechins may produce a synergistic colon cancer-preventative effect that would be more potent than each of the compounds alone. Copyright 2009 Elsevier Ltd. All rights reserved.

Dose response study of conjugated fatty acid derived from safflower oil on mammary and colon carcinogenesis pretreated with 7,12-dimethylbenz[a]anthracene (DMBA) and 1,2-dimethylhydrazine (DMH) in female Sprague-Dawley rats.

PubMed

Cheng, Jing Lei; Futakuchi, Mitsuru; Ogawa, Kumiko; Iwata, Toshio; Kasai, Masaaki; Tokudome, Shinkan; Hirose, Masao; Shirai, Tomoyuki

2003-07-10

To clarify the chemopreventive effects of conjugated fatty acid derived from safflower oil (CFA-S), rich in conjugated linoleic acid (CLA), on mammary and colon carcinogenesis, 6 week old female Sprague-Dawley (SD) rats received diet containing 0.01, 0.05, 0.1, 1, or 2% CFA-S subsequent to five times subcutaneous injections of 1,2-dimethyl-hydrazine (DMH) at a dose of 40 mg/kg b.w. and a single 50 mg/kg b.w. intragastric application of 7,12-dimethylbenz[a]anthracene (DMBA) during the first 11 days. The experiment was terminated at week 36. Numbers of mammary tumors, colon aberrant crypt foci (ACF), and proliferative indices of mammary tumors, and colon epithelium were analyzed. The 1% dose was found to be optimal for suppression of carcinogenesis in both target organs, a good correlation being noted with between data for cell proliferation. These results suggest that a diet containing appropriate levels of CFA-S may be useful for prevention of mammary and colon cancer.

Human aberrant crypt foci with carcinoma in situ from a patient with sporadic colon cancer.

PubMed

Konstantakos, A K; Siu, I M; Pretlow, T G; Stellato, T A; Pretlow, T P

1996-09-01

Aberrant crypt foci are putative preneoplastic lesions found in the colons of carcinogen-treated rodents and at an increased frequency in humans at increased risk for colon cancer. There is a strong association between aberrant crypt foci and colon cancer, including many shared phenotypic and genetic alterations. The aim of this study is to present further evidence of a relationship between aberrant crypt foci and colon cancer in humans. Multiple aberrant crypt foci from a single patient were identified in unembedded colonic mucosa. Histological sections of the aberrant crypt foci and adjacent mucosa were evaluated for dysplasia, proliferative activity, and pigment-laden macrophages that were characterized with histochemical techniques. The first patient with sporadic colon cancer identified with aberrant crypt foci with carcinoma in situ is described. It is interesting that this 99-year-old patient had multiple carcinomas in situ, pseudomelanosis coli, and two metachronous colon cancers. These data lend support to the hypothesis that aberrant crypt foci are precursors of some colon cancers.

Hypothalamic beta-endorphin neurons suppress preneoplastic and neoplastic lesions development in 1,2-dimethylhydrazine induced rat colon cancer model.

PubMed

Murugan, Sengottuvelan; Dave, Yatee; Rakhit, Ankush; Sarkar, Dipak K

2017-01-01

In recent years, experimental studies demonstrated negative impacts of impaired body stress response on colonic pathologies. In this study, we tested if reducing body stress response by the use of β-endorphin (BEP) neuronal transplants in the hypothalamus suppresses pre-neoplastic and neoplastic lesions. Colon cancer was induced by injecting 1,2-dimethylhydrazine (DMH) for sixteen weeks in Sprague Dawley rats with BEP neuron transplants or control neuron transplants, and their colonic histopathologies, colon tissue levels of pro-inflammatory cytokines and epithelial-mesenchymal transition (EMT) proteins and splenic levels of cytotoxic proteins were measured. Our results revealed that DMH induced tumors in colon at 100% incidence in control rats but failed to induce colonic tumors in 70% of animal with BEP neuronal transplants. The mean volume of tumor at the colon was smaller in BEP neurons transplanted rats than those in controls. Histopathologies of colon tissues revealed that BEP neurons transplanted animals had lesser tissue lesions such as aberrant crypt foci (ACF) and adenocarcinoma development in the colon than those in control groups. Immunohistochemical and western blot analyses identified reduced expression of Ki-67, TNF-α and NF-κB nuclear translocation in colonic tissues of BEP neurons transplanted rats than those in controls. BEP neurons transplanted rats also showed reduced expressions of transcription factors linked to EMT like Snail, Twist, and N-cadherin, but increased the levels of an epithelial cell marker E-cadherin in colon tissue. Furthermore, splenic NK cells cytolytic proteins such as perforin, granzyme B and IFN-γ levels in BEP neurons transplanted rats were higher than those in control rats. These data suggest that BEP neuron transplants suppress the growth and progression of colonic tumors possibly by decreasing inflammatory mileu and EMT via activation of innate immune responses.

The protective effects of fermented kefir milk on azoxymethane-induced aberrant crypt formation in mice colon.

PubMed

Melo, Aline Freitas de Paula; Mendonça, Monique Culturato Padilha; Rosa-Castro, Raquel de Mendonça

2018-06-01

Kefir is a probiotic fermented milk product produced from grains with a complex composition of bacteria and yeasts that live in a symbiotic association. Anti-proliferative, anti-inflammatory, and anti-mutagenic effects are some of the health beneficial properties of kefir grains. The present study was conducted to evaluate whether regular consumption of kefir milk would be capable of preventing the development of pre-neoplastic lesions induced by azoxymethane (AOM). Aberrant crypt foci were induced in BALB-c mice via 2 subcutaneous injections of azoxymethane (15 mg/kg) and kefir was administered by daily gavage for 8 weeks (5 ml/kg). Additionally, bacterial growth was monitored in pasteurized and ultra-high temperature (UHT) treated milk to compare different fermentation conditions. Our results showed that UHT milk presented better growth of Lactobacillus acidophilus colonies. The aberrant crypt foci were attenuated by approximately 43% (height) and 20% (width) in the kefir group compared to AOM group, suggesting that kefir treatment may contribute to prevent and control the growth of intestinal neoplastic cells. Copyright © 2018 Elsevier Ltd. All rights reserved.

Induction of colonic aberrant crypts in mice by feeding apparent N-nitroso compounds derived from hot dogs

PubMed Central

Davis, Michael E; Lisowyj, Michal P; Zhou, Lin; Wisecarver, James L; Gulizia, James M; Shostrom, Valerie K; Naud, Nathalie; Corpet, Denis E; Mirvish, Sidney S

2012-01-01

Nitrite-preserved meats (e.g., hot dogs) may help cause colon cancer because they contain N-nitroso compounds. We tested whether purified hot-dog-derived total apparent N-nitroso compounds (ANC) could induce colonic aberrant crypts, which are putative precursors of colon cancer. We purified ANC precursors in hot dogs and nitrosated them to produce ANC. In preliminary tests, CF1 mice received 1 or 3 i.p. injections of 5mg azoxymethane (AOM)/kg. In Experiments 1 and 2, female A/J mice received ANC in diet. In Experiment 1, ANC dose initially dropped sharply because the ANC precursors had mostly decomposed but, later in Experiment 1 and throughout Experiment 2, ANC remained at 85 nmol/g diet. Mice were killed after 8 (AOM tests) or 17–34 (ANC tests) wk. Median numbers of aberrant crypts in the distal 2 cm of the colon for 1 and 3 AOM injections, CF1 controls, ANC (Experiment 1), ANC (Experiment 2),and untreated A/J mice were 31, 74, 12, 20, 12, and 5–6, with P < 0.01 for both ANC tests. Experiment 2 showed somewhat increased numbers of colonic mucin-depleted foci in the ANC-treated group. We conclude that hot-dog-derived ANC induced significant numbers of aberrant crypts in the mouse colon. PMID:22293095

Origin of Aberrant Blood Pressure and Sympathetic Regulation in Diet-Induced Obesity.

PubMed

Lim, Kyungjoon; Barzel, Benjamin; Burke, Sandra L; Armitage, James A; Head, Geoffrey A

2016-08-01

High fat diet (HFD)-induced hypertension in rabbits is neurogenic and caused by the central action of leptin, which is thought to be dependent on activation of α-melanocortin-stimulating hormone (α-MSH) and neuropeptide Y-positive neurons projecting to the dorsomedial hypothalamus (DMH) and ventromedial hypothalamus (VMH). However, leptin may act directly in these nuclei. Here, we assessed the contribution of leptin, α-MSH, and neuropeptide Y signaling in the DMH and VMH to diet-induced hypertension. Male New Zealand white rabbits were instrumented with a cannula for drug injections into the DMH or VMH and a renal sympathetic nerve activity (RSNA) electrode. After 3 weeks of an HFD (13.3% fat; n=19), rabbits exhibited higher RSNA, mean arterial pressure (MAP), and heart rate compared with control diet-fed animals (4.2% fat; n=15). Intra-VMH injections of a leptin receptor antagonist or SHU9119, a melanocortin 3/4 receptor antagonist, decreased MAP, heart rate, and RSNA compared with vehicle in HFD rabbits (P<0.05) but not in control diet-fed animals. By contrast, α-MSH or neuropeptide Y injected into the VMH had no effect on MAP but produced sympathoexcitation in HFD rabbits (P<0.05) but not in control diet-fed rabbits. The effects of the leptin antagonist, α-MSH, or neuropeptide Y injections into the DMH on MAP or RSNA of HFD rabbits were not different from those after vehicle injection. α-MSH into the DMH of control diet-fed animals did increase MAP, heart rate, and RSNA. We conclude that the VMH is the likely origin of leptin-mediated sympathoexcitation and α-MSH hypersensitivity that contribute to obesity-related hypertension. © 2016 American Heart Association, Inc.

Colonic aberrant crypts may originate from impaired fissioning: relevance to increased risk of neoplasia.

PubMed

Kristt, D; Bryan, K; Gal, R

1999-12-01

Colonic aberrant crypt foci (ACF) can be identified on the unembedded mucosal surface as clusters of abnormal crypts with enlarged, surface opening. Because dysplasia is frequent, and may be a precursor of carcinoma, epithelial changes have been well studied. However, the basis for the distinctive changes in crypt architecture remain unclear. We hypothesized that some of the architectural alterations of aberrant crypts may reflect impaired fissioning during normal crypt duplication cycles. Fissioning begins at the crypt base. Using morphometric and immunocytochemical approaches, we examined 55 human ACF, both dysplastic and nondysplastic, for their architectural features. Non-ACF mucosa was compared. Microscopically, all lesions contained crypts that were attached, paired, dilated, and angulated. In 3 dimensions, these features related to multiple, individual complexes of connected crypts, referred to as connected crypt structures (CCSs). CCSs terminated in enlarged surface openings (2 to 5 x normal) which are morphometrically equivalent to the macroscopic aberrant crypts (P > .1). These openings trap marker dye. Support for an origin of CCSs in impaired basal fissioning is 3-fold. Crypt profiles in ACF are twice as frequent in basal mucosa as superficially (P < .001); in normal mucosa, the ratio is 1. In a CCS with vertically connected, co-planar crypts, the upper parent crypt diameter was the sum of diameters of inferiorly attached daughter crypts (P > .1). Proliferating cell marker, Ki-67, is not expressed at attachment points. In non-ACF mucosa, isolated CCSs consistently occur at foci of mechanical crypt distortion such as mucosal folds. We conclude that a CCS is a fundamental component of ACF of all histotypes. Impairment of normal crypt fissioning is probably a major factor in the histogenesis of CCSs, which often occurs in settings of mechanical distortion of the mucosa. The pathological significance of this process may be in the formation of enlarged crypt openings. The latter could trap dietary carcinogens as they trap dye, and thereby predispose the CCS to dysplasia.

THE EFFECTS OF A HIGH ANIMAL FAT DIET ON THE INDUCTION OF ABERRANT CRYPT FOCI IN THE COLONS OF MALE F344/N RATS EXPOSED TO TRIHALOMETHANES IN THE DRINKING WATER

EPA Science Inventory

The Effects of a High Animal Fat Diet on the Induction of Aberrant Crypt Foci in the Colons of Male F344/N Rats Exposed to Trihalomethanes in the Drinking Water

Abstract

Aberrant crypt foci (ACF), identified as the putative precursor lesion in the development of co...

Does senna extract promote growth of aberrant crypt foci and malignant tumors in rat colon?

PubMed

Mascolo, N; Mereto, E; Borrelli, F; Orsi, P; Sini, D; Izzo, A A; Massa, B; Boggio, M; Capasso, F

1999-11-01

Current evidence suggests that aberrant crypt foci (ACF) can be used to evaluate agents for their potential colon carcinogenic activity. The aim of the present study was to determine whether senna pod extract (SE) itself induces ACF and tumors in the rat colon or increases the development of ACF and tumors induced by azoxymethane (AOM). A daily administration of SE 10 mg/kg by mouth for 13-28 weeks produced a weak laxative effect but did not itself cause the appearance of ACF or tumors. The numbers of ACF and tumors induced by AOM were, however, increased by a dose of SE (100 mg/kg) able to induce chronic diarrhea over three months. These results suggest that SE does not cause the appearance of ACF or tumors in the rat colon nor does it have a promoting effect when given to rats at a dose that produces laxation (10 mg/kg), whereas a diarrhogenic dose (100 mg/kg) increases the appearance of tumors induced by AOM.

Plum polyphenols inhibit colorectal aberrant crypt foci formation in rats: potential role of the miR-143/protein kinase B/mammalian target of rapamycin axis.

PubMed

Banerjee, Nivedita; Kim, Hyemee; Talcott, Stephen T; Turner, Nancy D; Byrne, David H; Mertens-Talcott, Susanne U

2016-10-01

The nutritional prevention of aberrant crypt foci by polyphenols may be a crucial step to dietary cancer prevention. The objective of this study was to determine the underlying mechanisms that contribute to the anti-inflammatory and antitumorigenic properties of plum (Prunus salicina L.) polyphenols, including chlorogenic acid and neochlorogenic acid, in azoxymethane (AOM)-treated rats. The hypothesis was that plum polyphenolics suppress AOM-induced aberrant crypt foci formation through alterations in the protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway and relative micro-RNA expressions. Sprague-Dawley rats (n=10/group) received plum beverage (1346mg gallic acid equivalents/L) or a control beverage ad libitum for 10 weeks with subcutaneous injections of AOM (15mg/kg) at weeks 2 and 3. Results show that the consumption of the plum beverage decreased the number of dysplastic aberrant crypt foci by 48% (P<.05) and lowered proliferation of mucosal cells by 24% (P<.05). The plum beverage decreased the activity of glutathione peroxidase, superoxide dismutase, and catalase in mucosal scrapings, as well as the superoxide dismutase activity in serum. The results were accompanied by a down-regulation of proinflammatory enzymes nuclear factor κB, nitric oxide synthase, cyclooxygenase-2, and vascular cell adhesion molecule 1 messenger RNA. Plum inhibited the expression of AKT and mTOR messenger RNA, phosphorylated AKT, mTOR, and hypoxia-inducible factor-1α protein levels, and the ratio of the phosphorylated/total protein expression of mTOR. Also, the plum beverage increased the expression of miR-143, which is involved in the regulation of AKT. These results suggest that plum polyphenols may exhibit a chemopreventive potential against colon carcinogenesis by impacting the AKT/mTOR pathway and miR-143. Copyright © 2016 Elsevier Inc. All rights reserved.

Chemopreventive effects of Ku-jin tea against AOM-induced precancerous colorectal lesions in rats and metabolomic analysis.

PubMed

Bi, Wu; Liu, Haibo; Shen, Jie; Zhang, Ling-Hua; Li, Pei; Peng, Bing; Cao, Li; Zhang, Pengfei; He, Chunnian; Xiao, Peigen

2017-11-21

Ku-jin tea (KJT) is a health beverage prepared from the leaves of the plant Acer tataricum subsp. ginnala that has been consumed in some regions of China for thousands of years. KJT contains high levels of anti-inflammatory and antioxidative compounds such as ginnalins, but little is known about the chemopreventive effect of KJT on colon cancer. In this study, we investigated the preventive effects of KJT on colon carcinogenesis using the azoxymethane (AOM)-induced precancerous colorectal lesion model in rats. The results showed that the number of aberrant crypts, aberrant crypt foci (ACF) and crypts/focus in rats of the KJT + AOM group were significantly decreased compared with rats of the AOM group (p < 0.01). Further exploration of the prevention mechanism of KJT by UPLC-QTOF/MS-based urinary metabolomics showed that 5 metabolic pathways were modulated, including purine metabolism and amino acid metabolism, in the group with KJT. In addition, the levels of the immunomodulatory cytokines IL-1α and IL-10 were significantly decreased, and the levels of IL-2 in the serum of AOM rats increased after KJT treatment. Our present data suggest that KJT can inhibit AOM-induced colonic ACF formation and might be a useful chemopreventive agent against colorectal carcinogenesis.

WNT signaling controls expression of pro-apoptotic BOK and BAX in intestinal cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zeilstra, Jurrit; Joosten, Sander P.J.; Wensveen, Felix M.

Research highlights: {yields} Intestinal adenomas initiated by aberrant activation of the WNT pathway displayed an increased sensitivity to apoptosis. {yields} Expression profiling of apoptosis-related genes in Apc{sup Min/+} mice revealed the differential expression of pro-apoptotic Bok and Bax. {yields} APC-mutant adenomatous crypts in FAP patients showed strongly increased BAX immunoreactivity. {yields} Blocking of {beta}-catenin/TCF-4-mediated signaling in colon cancer cells reduced the expression of BOK and BAX. -- Abstract: In a majority of cases, colorectal cancer is initiated by aberrant activation of the WNT signaling pathway. Mutation of the genes encoding the WNT signaling components adenomatous polyposis coli or {beta}-catenin causesmore » constitutively active {beta}-catenin/TCF-mediated transcription, driving the transformation of intestinal crypts to cancer precursor lesions, called dysplastic aberrant crypt foci. Deregulated apoptosis is a hallmark of adenomatous colon tissue. However, the contribution of WNT signaling to this process is not fully understood. We addressed this role by analyzing the rate of epithelial apoptosis in aberrant crypts and adenomas of the Apc{sup Min/+} mouse model. In comparison with normal crypts and adenomas, aberrant crypts displayed a dramatically increased rate of apoptotic cell death. Expression profiling of apoptosis-related genes along the crypt-villus axis and in Apc mutant adenomas revealed increased expression of two pro-apoptotic Bcl-2 family members in intestinal adenomas, Bok and Bax. Analysis of the colon of familial adenomatous polyposis (FAP) patients along the crypt-to-surface axis, and of dysplastic crypts, corroborated this expression pattern. Disruption of {beta}-catenin/TCF-4-mediated signaling in the colorectal cancer cell line Ls174T significantly decreased BOK and BAX expression, confirming WNT-dependent regulation in intestinal epithelial cells. Our results suggest a feedback mechanism by which uncontrolled epithelial cell proliferation in the stem cell compartment can be counterbalanced by an increased propensity to undergo cell death.« less

PROMOTION OF TRIHALOMETHANE-INDUCED COLON, ABERRANT CRYPT FOCI (ACF) BY A HIGH FAT DIET

EPA Science Inventory

Abstract:

Bromodichloromethane (BOCM) and tribromomethane (TBM) enhanced neoplasia in the large intestine of rats when given by corn oil gavage; BOCM in the drinking water to male rats did not induce colon tumors, but did increase liver tumors. However, TBM and a mixture o...

Asymmetry in the control of cardiac performance by dorsomedial hypothalamus.

PubMed

Xavier, Carlos Henrique; Beig, Mirza Irfan; Ianzer, Danielle; Fontes, Marco Antônio Peliky; Nalivaiko, Eugene

2013-04-15

Dorsomedial hypothalamus (DMH) plays a key role in integrating cardiovascular responses to stress. We have recently reported greater heart rate responses following disinhibition of the right side of the DMH (R-DMH) in anesthetized rats and greater suppression of stress-induced tachycardia following inhibition of the R-DMH in conscious rats [both compared with similar intervention in the left DMH (L-DMH)], suggesting existence of right/left side asymmetry in controlling cardiac chronotropic responses by the DMH. The aim of the present study was to determine whether similar asymmetry is present for controlling cardiac contractility. In anesthetized rats, microinjections of the GABAA antagonist bicuculline methiodide (BMI; 40 pmol/100 nl) into the DMH-evoked increases in heart rate (HR), left ventricular pressure (LVP), myocardial contractility (LVdP/dt), arterial pressure, and respiratory rate. DMH disinhibition also precipitated multiple ventricular and supraventricular ectopic beats. DMH-induced increases in HR, LVP, LVdP/dt, and in the number of ectopic beats dependent on the side of stimulation, with R-DMH provoking larger responses. In contrast, pressor and respiratory responses did not depend on the side of stimulation. Newly described DMH-induced inotropic responses were rate-, preload- and (largely) afterload-independent; they were mediated by sympathetic cardiac pathway, as revealed by their sensitivity to β-adrenergic blockade. We conclude that recruitment of DMH neurons causes sympathetically mediated positive chronotropic and inotropic effects, and that there is an asymmetry, at the level of the DMH, in the potency to elicit these effects, with R-DMH > L-DMH.

Impact of novel sorghum bran diets on DSS-induced colitis

USDA-ARS?s Scientific Manuscript database

Background. Repeated bouts of inflammation are known to promote colon cancer. We have reported that polyphenol-rich sorghum bran diets decrease formation of colon aberrant crypt foci, however, little is known regarding their effect during colonic inflammation. Objective. We hypothesized that sorgh...

Assessment of K-Ras mutant frequency and micronucleus incidence in the mouse duodenum following 90-days of exposure to Cr(VI) in drinking water.

PubMed

O'Brien, Travis J; Ding, Hao; Suh, Mina; Thompson, Chad M; Parsons, Barbara L; Harris, Mark A; Winkelman, William A; Wolf, Jeffrey C; Hixon, J Gregory; Schwartz, Arnold M; Myers, Meagan B; Haws, Laurie C; Proctor, Deborah M

2013-06-14

Chronic exposure to high concentrations of hexavalent chromium [Cr(VI)] as sodium dichromate dihydrate (SDD) in drinking water induces duodenal tumors in mice, but the mode of action (MOA) for these tumors has been a subject of scientific debate. To evaluate the tumor-site-specific genotoxicity and cytotoxicity of SDD in the mouse small intestine, tissue pathology and cytogenetic damage were evaluated in duodenal crypt and villus enterocytes from B6C3F1 mice exposed to 0.3-520mg/L SDD in drinking water for 7 and 90 days. Allele-competitive blocker PCR (ACB-PCR) was used to investigate the induction of a sensitive, tumor-relevant mutation, specifically in vivo K-Ras codon 12 GAT mutation, in scraped duodenal epithelium following 90 days of drinking water exposure. Cytotoxicity was evident in the villus as disruption of cellular arrangement, desquamation, nuclear atypia and blunting. Following 90 days of treatment, aberrant nuclei, occurring primarily at villi tips, were significantly increased at ≥60mg/L SDD. However, in the crypt compartment, there were no dose-related effects on mitotic and apoptotic indices or the formation of aberrant nuclei indicating that Cr(VI)-induced cytotoxicity was limited to the villi. Cr(VI) caused a dose-dependent proliferative response in the duodenal crypt as evidenced by an increase in crypt area and increased number of crypt enterocytes. Spontaneous K-Ras codon 12 GAT mutations in untreated mice were higher than expected, in the range of 10(-2) to 10(-3); however no treatment-related trend in the K-Ras codon 12 GAT mutation was observed. The high spontaneous background K-Ras mutant frequency and Cr(VI) dose-related increases in crypt enterocyte proliferation, without dose-related increase in K-Ras mutant frequency, micronuclei formation, or change in mitotic or apoptotic indices, are consistent with a lack of genotoxicity in the crypt compartment, and a MOA involving accumulation of mutations late in carcinogenesis as a consequence of sustained regenerative proliferation. Published by Elsevier B.V.

Senna and the formation of aberrant crypt foci and tumors in rats treated with azoxymethane.

PubMed

Borrelli, F; Capasso, R; Aviello, G; Di Carlo, G; Izzo, A A; Mascolo, N; Capasso, F

2005-06-01

Chronic use of anthraquinone laxatives has been blamed for the induction of habituation and the development of colonic cancer, but there are no definitive studies which have demonstrated this. To evaluate the carcinogenic potential of anthraquinones, the effect of long-term senna pod extract (SE) treatment on either healthy rats or rats treated with an initiating tumor agent (azoxymethane--AOM) has been studied. SE (30 and 60mg/kg), administered for 110 weeks, did not induce the development of aberrant crypt foci (ACF) and tumors in healthy rats. The development of ACF and tumors in rats treated with AOM were significantly reduced by SE (30 and 60 mg/kg). These results suggest that a chronic SE use does not predispose to colon cancer. By contrast, SE might exert an anti-tumoral activity on rat colon carcinogenesis.

THE INDUCTION OF ABERRANT CRYPT FOCI IN THE COLONS OF MALE F344/N RATS EXPOSED TO THIHALOMETHANE MIXTURES IN THE DRINKING WATER

EPA Science Inventory

THE INDUCTION OF ABERRANT CRYPT FOCI IN THE COLONS OF MALE F344/N
RATS EXPOSED TO TRIHALOMETHANE MIXTURES IN THE DRINKING WATER

The trihalomethanes (THM), bromoform (TBM) and bromodichloromethane (BDCM), administered by corn oil gavage were found to increase large...

TRIBROMOMETHANE EXPOSURE AND DIETARY FOLATE DEFICIENCY IN THE FORMATION OF ABERRANT CRYPT FOCI IN THE COLONS OF F344/N RATS

EPA Science Inventory

TRIBROMOMETHANE EXPOSURE AND DIETARY FOLATE DEFICIENCY IN THE FORMATION OF ABERRANT CRYPT FOCI IN THE COLONS OF F344/N RATS

David R. Geter', Tanya M. Moore', Michael H. George', Steve R. Kilburn', Gloria Huggins-Clark', James W. Allen', and Anthony B. DeAngelo' 'National H...

Colonic aberrant crypt formation accompanies an increase of opportunistic pathogenic bacteria in C57BL/6 mice fed a high-fat diet

USDA-ARS?s Scientific Manuscript database

Background: The increasing worldwide incidence of colon cancer has been linked to obesity and consumption of a high-fat western diet, but the mechanism underlying this relationship remains to be determined. Objective: We tested the hypothesis that a high-fat diet promotes aberrant crypt (AC) format...

Beneficial influence of ellagic acid on biochemical indexes associated with experimentally induced colon carcinogenesis.

PubMed

Syed, Umesalma; Ganapasam, Sudhandiran

2017-01-01

To elucidate the key biochemical indexes associated with 1, 2-dimethylhydrazine (DMH)-induced colon carcinogenesis and the modulatory efficacy of a dietary polyphenol, ellagic acid (EA). Wistar rats were chosen to study objective, and were divided into 4 groups; Group 1-control rats; Group 2-rats received EA (60 mg/kg body weight/day, orally); rats in Group 3-induced with DMH (20 mg/kg body weight) subcutaneously for 15 weeks; DMH-induced Group 4 rats were initiated with EA treatment. We examined key citric acid cycle enzymes such as isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase, succinate dehydrogenase, malate dehydrogenase and the activities of respiratory chain enzymes NADH dehydrogenase and Cytochrome-C-oxidase and membrane-bound enzyme profiles (Na +/K + ATPase, Ca 2+ ATPase and Mg 2+ ATPase), activities of lysosomal proteases such as β-D-glucuronidase, β-galactosidase and N-acety-β-D-glucosaminidase and cellular thiols (oxidized glutathione, protein thiols, and total thiols). It was found that administration of DMH to rats decreased both mitochondrial and membrane-bound enzymes activities, increased activities of lysosomal enzymes and further modulates cellular thiols levels. Treatment with EA significantly restored the mitochondrial and ATPases levels and further reduced lysosomal enzymes to near normalcy thereby restoring harmful effects induced by DMH. EA treatment was able to effectively restore the detrimental effects induced by DMH, which proves the chemoprotective function of EA against DMH-induced experimental colon carcinogenesis.

VEHICLE AND MODE OF ADMINISTRATION EFFECTS ON THE INDUCTION OF ABERRANT CRYPT FOCI IN THE COLONS OF MALE F344/N RATS EXPOSED TO BROMODICHLOROMETHANE

EPA Science Inventory

Vehicle and Mode of Administration Effects on the Induction of Aberrant Crypt Foci in the Colons of Male F344/N Rats Exposed to Bromodichloromethane.

David R. Geter, Michael H. George, Tanya M. Moore, Steve Kilburn, Gloria Huggins-Clark, and Anthony B. DeAngelo. Submited ...

Aberrant crypt formation accompanies an increase of opportunistic pathogens/bacteria in the inflammatory gut of C57BL/6 mice fed a high-fat diet

USDA-ARS?s Scientific Manuscript database

Obesity and high fat diet are risk factors for colon cancer, but the mechanism of this relationship remains to be determined. We tested the hypothesis that a high fat diet promotes the formation of aberrant crypt foci (ACF, preneoplastic lesions) in a manner associated with changes in hindgut bacter...

Histaminergic and cholinergic neuron systems in the impairment of human thermoregulation during motion sickness.

PubMed

Nobel, Gerard; Tribukait, Arne; Mekjavic, Igor B; Eiken, Ola

2010-05-31

Motion sickness (MS) exaggerates body cooling during cold-water immersion. The aim of the present study was to investigate whether such MS-induced predisposition to hypothermia is influenced by two anti-MS drugs: the histamine-receptor blocker dimenhydrinate (DMH) and the muscarine-receptor blocker scopolamine (Scop). Nine healthy male subjects were immersed in 15 degrees C water for a maximum of 90min in five conditions: (1) control (CN): no medication, no MS provocation; (2) MS-control (MS-CN): no medication, MS provocation; (3) MS-placebo (MS-P): placebo DMH and placebo Scop, MS provocation; (4) MS-DMH: DMH and placebo Scop, MS provocation; (5) MS-Scop: Scop and placebo DMH, MS provocation. MS was induced by use of a rotating chair. Throughout the experiments rectal temperature (T(re)), the difference in temperature between the non-immersed right forearm and third finger (T(ff)) as an index of peripheral vasoconstriction, and oxygen uptake (VO(2)) as a measure of shivering thermogenesis, were recorded. DMH and Scop were similarly efficacious in ameliorating nausea. The fall in T(re) was greater in the MS-CN and MS-P conditions than in the CN condition. DMH, but not Scop, prevented the MS-induced increase in body-core cooling. MS attenuated the cold-induced vasoconstriction, an effect which was fully prevented by DMH but only partially by Scop. MS provocation did not affect VO(2) in any condition. The results suggest that the MS-induced predisposition to hypothermia is predominantly mediated by histaminergic mechanisms and that DMH might be useful in conjunction with maritime accidents or other scenarios where exposure to cold and MS are imminent features. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Two types of putative preneoplastic lesions identified by hexosaminidase activity in whole-mounts of colons from F344 rats treated with carcinogen.

PubMed

Pretlow, T P; O'Riordan, M A; Spancake, K M; Pretlow, T G

1993-06-01

Previous studies identified as putative preneoplastic lesions 1) enzyme-altered foci in sections of methacrylate-embedded colon and 2) aberrant crypts in methylene blue-stained unembedded (whole-mount) colon and established that aberrant crypts embedded in methacrylate had enzyme alterations. We have now studied histochemically demonstrable hexosaminidase activity in unembedded or whole-mount preparations of colons from carcinogen-treated rats. These preparations have revealed two populations of crypts that are enzyme-altered: those that are morphologically altered or aberrant and those that are morphologically normal. Both populations can be quantified rigorously in less than an hour with whole-mount preparations reacted for hexosaminidase. The demonstration of phenotypic characteristics with histochemical techniques in whole-mount preparations should have wide applicability to functional studies in many normal and diseased tissues.

15-Hydroxyprostaglandin dehydrogenase is an in vivo suppressor of colon tumorigenesis.

PubMed

Myung, Seung-Jae; Rerko, Ronald M; Yan, Min; Platzer, Petra; Guda, Kishore; Dotson, Angela; Lawrence, Earl; Dannenberg, Andrew J; Lovgren, Alysia Kern; Luo, Guangbin; Pretlow, Theresa P; Newman, Robert A; Willis, Joseph; Dawson, Dawn; Markowitz, Sanford D

2006-08-08

15-Hydroxyprostaglandin dehydrogenase (15-PGDH) is a prostaglandin-degrading enzyme that is highly expressed in normal colon mucosa but is ubiquitously lost in human colon cancers. Herein, we demonstrate that 15-PGDH is active in vivo as a highly potent suppressor of colon neoplasia development and acts in the colon as a required physiologic antagonist of the prostaglandin-synthesizing activity of the cyclooxygenase 2 (COX-2) oncogene. We first show that 15-PGDH gene knockout induces a marked 7.6-fold increase in colon tumors arising in the Min (multiple intestinal neoplasia) mouse model. Furthermore, 15-PGDH gene knockout abrogates the normal resistance of C57BL/6J mice to colon tumor induction by the carcinogen azoxymethane (AOM), conferring susceptibility to AOM-induced adenomas and carcinomas in situ. Susceptibility to AOM-induced tumorigenesis is mediated by a marked induction of dysplasia, proliferation, and cyclin D1 expression throughout microscopic aberrant crypt foci arising in 15-PGDH null colons and is concomitant with a doubling of prostaglandin E(2) in 15-PGDH null colonic mucosa. A parallel role for 15-PGDH loss in promoting the earliest steps of colon neoplasia in humans is supported by our finding of a universal loss of 15-PGDH expression in microscopic colon adenomas recovered from patients with familial adenomatous polyposis, including adenomas as small as a single crypt. These models thus delineate the in vivo significance of 15-PGDH-mediated negative regulation of the COX-2 pathway and moreover reveal the particular importance of 15-PGDH in opposing the neoplastic progression of colonic aberrant crypt foci.

Astaxanthin inhibits tumor invasion by decreasing extracellular matrix production and induces apoptosis in experimental rat colon carcinogenesis by modulating the expressions of ERK-2, NFkB and COX-2.

PubMed

Nagendraprabhu, Ponnuraj; Sudhandiran, Ganapasam

2011-04-01

Colon cancer is the third most malignant neoplasm in the world and it remains an important cause of mortality in Asian and Western countries. Astaxanthin (AST), a major component of carotenoids possesses attractive remedial features. The purpose of this study is to investigate the possible mechanism of action of astaxanthin against 1, 2 dimethyl hydrazine (DMH)-induced rat colon carcinogenesis. Wistar male rats were randomized into five groups, group 1 were control rats, group 2 were rats that received AST (15 mg/kg body wt p.o. everyday), rats in group 3 were induced with DMH (40 mg/kg body wt, s.c.), DMH-induced rats in groups 4 and 5 were either pre or post initiated with AST, respectively as in group 2. DMH-induced rats exhibited elevated expressions of Nuclear factor kappa B-p65 (NF-κB-p65), Cyclooxygenase-2 (COX-2), Matrixmetallo proteinases (MMP) 2/9, Proliferating cell nuclear antigen (PCNA), and Extracellular signal-regulated kinase-2 (ERK-2) as confirmed by immunofluorescence. Further, Westernblot analysis of MMPs-2/9, ERK-2 and Protein kinase B (Akt) revealed increased expressions of these proteins in DMH-induced groups of rats. AST-treatment decreased the expressions of all these vital proteins, involved in colon carcinogenesis. The ability of AST to induce apoptosis in the colon of DMH-induced rats was confirmed by Annexin-V/PI staining in a confocal microscopy, DNA fragmentation analysis and expression of caspase-3 by Western blotting. In conclusion, astaxanthin exhibits anti-inflammatory and anti-cancer effects by inducing apoptosis in DMH-induced rat colon carcinogenesis by modulating the expressions of NFkB, COX-2, MMPs-2/9, Akt and ERK-2.

Two types of putative preneoplastic lesions identified by hexosaminidase activity in whole-mounts of colons from F344 rats treated with carcinogen.

PubMed Central

Pretlow, T. P.; O'Riordan, M. A.; Spancake, K. M.; Pretlow, T. G.

1993-01-01

Previous studies identified as putative preneoplastic lesions 1) enzyme-altered foci in sections of methacrylate-embedded colon and 2) aberrant crypts in methylene blue-stained unembedded (whole-mount) colon and established that aberrant crypts embedded in methacrylate had enzyme alterations. We have now studied histochemically demonstrable hexosaminidase activity in unembedded or whole-mount preparations of colons from carcinogen-treated rats. These preparations have revealed two populations of crypts that are enzyme-altered: those that are morphologically altered or aberrant and those that are morphologically normal. Both populations can be quantified rigorously in less than an hour with whole-mount preparations reacted for hexosaminidase. The demonstration of phenotypic characteristics with histochemical techniques in whole-mount preparations should have wide applicability to functional studies in many normal and diseased tissues. Images Figure 1 PMID:8506941

Effects of beta-glucuronidase-deficient and lycopene-producing Escherichia coli strains on formation of azoxymethane-induced aberrant crypt foci in the rat colon.

PubMed

Arimochi, H; Kataoka, K; Kuwahara, T; Nakayama, H; Misawa, N; Ohnishi, Y

1999-08-27

We tried to inhibit the formation of azoxymethane-induced aberrant crypt foci (ACF) in the rat intestine by feeding a culture of a beta-glucuronidase-deficient Escherichia coli strain or a cell suspension of a lycopene-producing E. coli strain. Feeding of the former culture to F344 rats did not decrease fecal beta-glucuronidase activity or the number of ACF compared with the control beta-glucuronidase-proficient groups. However, a significant positive correlation between the fecal beta-glucuronidase activity and the ACF number was observed among groups treated with cultures of beta-glucuronidase-proficient and -deficient strains. In the group treated with lycopene-producing cells, the number of ACF was significantly lower than that in the control group. A vegetable juice containing a larger amount of lycopene than a cell suspension of the lycopene-producing E. coli also decreased the number of ACF to the same extent as a cell suspension of the lycopene-producing bacteria. These results suggest that feeding of the beta-glucuronidase-deficient E. coli is not very effective in preventing colon carcinogenesis, although activity of the fecal beta-glucuronidase is associated with AOM-induced ACF formation, and that lycopene-producing intestinal bacteria can effectively prevent colon carcinogenesis. Copyright 1999 Academic Press.

Chemopreventive Efficacy of Andrographis paniculata on Azoxymethane-Induced Aberrant Colon Crypt Foci In Vivo

PubMed Central

Al-Henhena, Nawal; Ying, Rozaida Poh Yuen; Ismail, Salmah; Najm, Wala; Khalifa, Shaden A. M.; El-Seedi, Hesham; Abdulla, Mahmood Ameen

2014-01-01

Andrographis paniculata is a grass-shaped medicinal herb, traditionally used in Southeast Asia. The aim of this study was to evaluate the chemoprotective effects of A. paniculata on colorectal cancer. A. paniculata ethanol extract was tested on azoxymethane (AOM)-induced aberrant crypt foci (ACF) in vivo and in vitro. A. paniculata treated groups showed a significant reduction in the number of ACF of the treated rats. Microscopically, ACF showed remarkably elongated and stratified cells, and depletion of the submucosal glands of AOM group compared to the treated groups. Histologically, staining showed slightly elevated masses above the surrounding mucosa with oval or slit-like orifices. Immunohistochemically, expression of proliferating cell nuclear antigen (PCNA) and β-catenin protein were down-regulated in the A. paniculata treated groups compared to the AOM group. When colon tissue was homogenized, malondialdehyde (MDA) and nitric oxide (NO) levels were significantly decreased, whereas superoxide dismutase (SOD) activity was increased in the treated groups compared to the AOM group. A. paniculata ethanol extract showed antioxidant and free radical scavenging activity, as elucidated by the measure of oxidative stress markers. Further, the active fractions were assessed against cell lines of CCD841 and HT29 colon cancer cells. PMID:25390042

Chemopreventive efficacy of Andrographis paniculata on azoxymethane-induced aberrant colon crypt foci in vivo.

PubMed

Al-Henhena, Nawal; Ying, Rozaida Poh Yuen; Ismail, Salmah; Najm, Walaa; Najm, Wala; Khalifa, Shaden A M; El-Seedi, Hesham; Ameen Abdulla, Mahmood; Abdulla, Mahmood Ameen

2014-01-01

Andrographis paniculata is a grass-shaped medicinal herb, traditionally used in Southeast Asia. The aim of this study was to evaluate the chemoprotective effects of A. paniculata on colorectal cancer. A. paniculata ethanol extract was tested on azoxymethane (AOM)-induced aberrant crypt foci (ACF) in vivo and in vitro. A. paniculata treated groups showed a significant reduction in the number of ACF of the treated rats. Microscopically, ACF showed remarkably elongated and stratified cells, and depletion of the submucosal glands of AOM group compared to the treated groups. Histologically, staining showed slightly elevated masses above the surrounding mucosa with oval or slit-like orifices. Immunohistochemically, expression of proliferating cell nuclear antigen (PCNA) and β-catenin protein were down-regulated in the A. paniculata treated groups compared to the AOM group. When colon tissue was homogenized, malondialdehyde (MDA) and nitric oxide (NO) levels were significantly decreased, whereas superoxide dismutase (SOD) activity was increased in the treated groups compared to the AOM group. A. paniculata ethanol extract showed antioxidant and free radical scavenging activity, as elucidated by the measure of oxidative stress markers. Further, the active fractions were assessed against cell lines of CCD841 and HT29 colon cancer cells.

[Chemoprotective effect of the alkaloid extract of Melocactus bellavistensis against colon cancer induced in rats using 1,2-dimethylhydrazine].

PubMed

Ríos-León, Karla; Fuertes-Ruiton, Cesar; Arroyo, Jorge; Ruiz, Julio

2017-01-01

To determine the toxicity and chemoprotective effect of the alkaloid extract of Melocactus bellavistensis against colon cancer induced in rats using 1,2-dimethylhydrazine (DMH). The alkaloid extract was obtained from the fleshy part of M. bellavistensis, and an acute toxicity test was then carried out on 30 mice of the Balb C57 strain. To assess its chemoprotective effect, colon cancer was induced in 45 Holtzman rats using DMH according to the following experimental design: one control group received 2 mL/kg sodium polysorbate, and four groups received 20 mg/kg DMH plus 0, 1, 5, or 10 mg/kg M. bellavistensis alkaloid extract. With a sample of 5 g of alkaloid extract, an LD50 greater than 1000 mg/mL was determined in the acute toxicity test. Histological indicators revealed that the 5 and 10 mg/kg doses had significant anti-tumor activity with 100% neoplasia inhibition against DMH- induced colon cancer in rats. Under experimental conditions, the alkaloid extract of M. bellavistensis has a chemoprotective effect against DMH-induced colon cancer in rats.

THE INDUCTION OF ABERRANT CRYPT FOCI (ACF) IN MALE AND FEMALE F344/N RATS BY BROMOCHLOROACETIC ACID (BCA) ADMINISTERED IN THE DRINKING WATER

EPA Science Inventory

The Induction of Aberrant Crypt Foci (ACF) in Male and Female F344/N Rats by Bromochloroacetic Acid (BCA) Administered in the Drinking Water.

M.H. George1, D. Delker1, D.R. Geter1, C.Herbert2, J. Roycroft3, R. Melnick3, D.W.
Rosenberg4, and A.B. DeAngelo1. 1USEPA, Resea...

Suppressive Effect of Zinc on the Formation of Colonic Preneoplastic Lesions in the Mouse Fed High Levels of Dietary Iron

PubMed Central

Park, Hyunji; Kang, Bong Su; Kim, Dang Young; Yoon, Ja Seon; Jeong, Jae-Hwang; Nam, Sang Yoon; Yun, Young Won

2012-01-01

We investigated the effect of zinc on the formation of colonic aberrant crypt foci induced by azoxymethane (AOM) followed by dextran sodium sulfate (DSS) in mice with high iron diet (HFe; 450 ppm iron). Sixweek old ICR mice were fed on high iron diets with combination of three different levels of zinc in diets, low-zinc (LZn; 0.01 ppm), medium-zinc (MZn; 0.1 ppm), and high-zinc (HZn; 1 ppm) for 12 weeks. Animals were received weekly intraperitoneal injections of AOM (10 mg/kg B.W. in saline) for 3 weeks followed by 2% DSS (molecular weight 36,000~50,000) in the drinking water for a week. To confirm the iron storage in the body, the hepatic iron concentration has been determine chemically and compared with histological assessment visualized by Prussian blue reaction. Aberrant crypt (AC) and aberrant crypt foci (ACF) were analyzed in the colonic mucosa of mouse fed high dietary iron. Superoxide dismutase (SOD) activity and thiobarbituric acid-reactive substances (TBARS) level were also investigated. Apoptosis in the preneoplastic lesion was determined by terminal deoxynucleotidyl transferase-mediated dUTP nickend labeling (TUNEL). In addition, immunohistochemistry of β-catenin was also performed on the mucous membrane of colon. The number of large ACF (≥ 4 AC/ACF), which possess greater tumorigenic potential, was significantly lower in MZn and HZn groups compared with LZn group. Cytosolic SOD activity in the liver was significantly higher in HZn group compared with LZn group. Hepatic MDA level was decreased significantly in HZn group compared with MZn and LZn groups. Apoptotic index was significantly higher in HZn group. Taken together, these findings indicate that dietary zinc might exert a protective effect against colonic preneoplastic lesion induced by AOM/DSS in ICR mice with high iron status, and suggest that dietary supplement of zinc might play a role in suppressing colon carcinogenesis in mice. PMID:24278588

Anti-inflammatory effects of the cannabidiol derivative dimethylheptyl-cannabidiol - studies in BV-2 microglia and encephalitogenic T cells.

PubMed

Juknat, Ana; Kozela, Ewa; Kaushansky, Nathali; Mechoulam, Raphael; Vogel, Zvi

2016-05-01

Dimethylheptyl-cannabidiol (DMH-CBD), a non-psychoactive, synthetic derivative of the phytocannabinoid cannabidiol (CBD), has been reported to be anti-inflammatory in RAW macrophages. Here, we evaluated the effects of DMH-CBD at the transcriptional level in BV-2 microglial cells as well as on the proliferation of encephalitogenic T cells. BV-2 cells were pretreated with DMH-CBD, followed by stimulation with the endotoxin lipopolysaccharide (LPS). The expression levels of selected genes involved in stress regulation and inflammation were determined by quantitative real-time PCR. In addition, MOG35-55-reactive T cells (TMOG) were cultured with antigen-presenting cells in the presence of DMH-CBD and MOG35-55 peptide, and cell proliferation was determined by measuring [3H]thymidine incorporation. DMH-CBD treatment downregulated in a dose-dependent manner the mRNA expression of LPS-upregulated pro-inflammatory genes (Il1b, Il6, and Tnf) in BV-2 microglial cells. The expression of these genes was also downregulated by DMH-CBD in unstimulated cells. In parallel, DMH-CBD upregulated the expression of genes related to oxidative stress and glutathione homeostasis such as Trb3, Slc7a11/xCT, Hmox1, Atf4, Chop, and p8 in both stimulated and unstimulated microglial cells. In addition, DMH-CBD dose-dependently inhibited MOG35-55-induced TMOG proliferation. The results show that DMH-CBD has similar anti-inflammatory properties to those of CBD. DMH-CBD downregulates the expression of inflammatory cytokines and protects the microglial cells by inducing an adaptive cellular response against inflammatory stimuli and oxidative injury. In addition, DMH-CBD decreases the proliferation of pathogenic activated TMOG cells.

Newly defined aberrant crypt foci as a marker for dysplasia in the rat colon

PubMed Central

Ochiai, Masako; Hippo, Yoshitaka; Izumiya, Masashi; Watanabe, Masatoshi; Nakagama, Hitoshi

2014-01-01

Dysplasia represents a preneoplastic status in multistep colon carcinogenesis. Whereas laborious preparation of thin sections is required for its diagnosis, we here show that newly defined aberrant crypt foci (ACF) simply mark the majority of the dysplasia on the whole colon. Specifically, decoloring of the azoxymethane-treated rat colon after scoring classical ACF (cACF) resulted in visualization of a subset of aberrant crypts that remained densely stained. They were morphologically classified into three subtypes, of which two with compressed luminal openings proved highly correlated with dysplasia. Accordingly, we designated those foci harboring either of the two crypt subtypes as dysplasia-associated ACF (dACF). By serially applying different detection methods for known preneoplastic lesions to the same colon, we showed that most dACF had already been identified as cACF, and a few newly identified dACF contained an entire population of more advanced lesions, such as flat ACF and mucin-depleted foci. Consequently, integrative scoring of cACF and dACF enabled capture of all early lesions of the colon. Furthermore, 94% of the dACF showed dysplasia and 90% of the dysplastic lesions proved to be dACF. Thus, dACF is a promising marker for dysplasia, likely facilitating precise identification of the early stages of colon carcinogenesis. PMID:24827115

(+)-Cannabidiol analogues which bind cannabinoid receptors but exert peripheral activity only.

PubMed

Fride, Ester; Feigin, Cfir; Ponde, Datta E; Breuer, Aviva; Hanus, Lumír; Arshavsky, Nina; Mechoulam, Raphael

2004-12-15

Delta9-Tetrahydrocannabinol (Delta9-THC) and (-)-cannabidiol are major constituents of the Cannabis sativa plant with different pharmacological profiles: (-)-Delta9-tetrahydrocannabinol, but not (-)-cannabidiol, activates cannabinoid CB1 and CB2 receptors and induces psychoactive and peripheral effects. We have tested a series of (+)-cannabidiol derivatives, namely, (+)-cannabidiol-DMH (DMH-1,1-dimethylheptyl-), (+)-7-OH-cannabidiol-DMH, (+)-7-OH- cannabidiol, (+)-7-COOH- cannabidiol and (+)-7-COOH-cannabidiol-DMH, for central and peripheral (intestinal, antiinflammatory and peripheral pain) effects in mice. Although all (+)-cannabidiols bind to cannabinoid CB1 and CB2 receptors, only (+)-7-OH-cannabidiol-DMH was centrally active, while all (+)-cannabidiol analogues completely arrested defecation. The effects of (+)-cannabidiol-DMH and (+)-7-OH-cannabidiol-DMH were partially antagonized by the cannabinoid CB1 receptor antagonist N-(piperidiny-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (SR141716), but not by the cannabinoid CB2 receptor antagonist N-[-(1S)-endo-1,3,3-trimethil bicyclo [2.2.1] heptan-2-yl-5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)-pyrazole-3-carboxamide (SR144528), and had no effect on CB1(-/-) receptor knockout mice. (+)-Cannabidiol-DMH inhibited the peripheral pain response and arachidonic-acid-induced inflammation of the ear. We conclude that centrally inactive (+)-cannabidiol analogues should be further developed as antidiarrheal, antiinflammatory and analgesic drugs for gastrointestinal and other peripheral conditions.

Intestinal Cell Proliferation and Senescence Are Regulated by Receptor Guanylyl Cyclase C and p21*

PubMed Central

Basu, Nirmalya; Saha, Sayanti; Khan, Imran; Ramachandra, Subbaraya G.; Visweswariah, Sandhya S.

2014-01-01

Guanylyl cyclase C (GC-C) is expressed in intestinal epithelial cells and serves as the receptor for bacterial heat-stable enterotoxin (ST) peptides and the guanylin family of gastrointestinal hormones. Activation of GC-C elevates intracellular cGMP, which modulates intestinal fluid-ion homeostasis and differentiation of enterocytes along the crypt-villus axis. GC-C activity can regulate colonic cell proliferation by inducing cell cycle arrest, and mice lacking GC-C display increased cell proliferation in colonic crypts. Activation of GC-C by administration of ST to wild type, but not Gucy2c−/−, mice resulted in a reduction in carcinogen-induced aberrant crypt foci formation. In p53-deficient human colorectal carcinoma cells, ST led to a transcriptional up-regulation of p21, the cell cycle inhibitor, via activation of the cGMP-responsive kinase PKGII and p38 MAPK. Prolonged treatment of human colonic carcinoma cells with ST led to nuclear accumulation of p21, resulting in cellular senescence and reduced tumorigenic potential. Our results, therefore, identify downstream effectors for GC-C that contribute to regulating intestinal cell proliferation. Thus, genomic responses to a bacterial toxin can influence intestinal neoplasia and senescence. PMID:24217248

Chemoprevention by Probiotics During 1,2-Dimethylhydrazine-Induced Colon Carcinogenesis in Rats.

PubMed

Walia, Sohini; Kamal, Rozy; Dhawan, D K; Kanwar, S S

2018-04-01

Probiotics are believed to have properties that lower the risk of colon cancer. However, the mechanisms by which they exert their beneficial effects are relatively unknown. To assess the impact of probiotics in preventing induction of colon carcinogenesis in rats. The rats were divided into six groups viz., normal control, Lactobacillus plantarum (AdF10)-treated, Lactobacillus rhamnosus GG (LGG)-treated, 1,2-dimethylhydrazine (DMH)-treated, L. plantarum (AdF10) + DMH-treated and L. rhamnosus GG (LGG) + DMH-treated. Both the probiotics were supplemented daily at a dose of 2 × 10 10 cells per day. DMH at a dose of 30 mg/kg body weight was administered subcutaneously twice a week for the first 4 weeks and then once every week for a duration of 16 weeks. Glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and catalase as protein expression of genes involved in apoptosis were assessed during DMH-induced colon carcinogenesis in rats. DMH treatment decreased the activity of GSH, GPx, GST, SOD and catalase. However, AdF10 and LGG supplementation to DMH-treated rats significantly increased the activity of these enzymes. Further, DMH treatment revealed alterations in the protein expressions of various genes involved in the p53-mediated apoptotic pathway such as p53, p21, Bcl-2, Bax, caspase-9 and caspase-3, which, however, were shifted towards normal control levels upon simultaneous supplementation with probiotics. The present study suggests that probiotics can provide protection against oxidative stress and apoptotic-related protein disregulation during experimentally induced colon carcinogenesis.

Synchrotron-based imaging of chromium and  γ-H2AX immunostaining in the duodenum following repeated exposure to Cr(VI) in drinking water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thompson, Chad M.; Seiter, Jennifer; Chappell, Mark A.

Current drinking water standards for chromium are for the combined total of both hexavalent and trivalent chromium (Cr(VI) and Cr(III)). However, recent studies have shown that Cr(III) is not carcinogenic to rodents, whereas mice chronically exposed to high levels of Cr(VI) developed duodenal tumors. These findings may suggest the need for environmental standards specific for Cr(VI). Whether the intestinal tumors arose through a mutagenic or non-mutagenic mode of action (MOA) greatly impacts how drinking water standards for Cr(VI) are derived. Herein, X-ray fluorescence (spectro)microscopy (µ-XRF) was used to image the Cr content in the villus and crypt regions of duodenamore » from B6C3F1 mice exposed to 180 mg/l Cr(VI) in drinking water for 13 weeks. DNA damage was also assessed by γ-H2AX immunostaining. Exposure to Cr(VI) induced villus blunting and crypt hyperplasia in the duodenum—the latter evidenced by lengthening of the crypt compartment by ~2-fold with a concomitant 1.5-fold increase in the number of crypt enterocytes. γ-H2AX immunostaining was elevated in villi, but not in the crypt compartment. µ-XRF maps revealed mean Cr levels >30 times higher in duodenal villi than crypt regions; mean Cr levels in crypt regions were only slightly above background signal. Despite the presence of Cr and elevated γ-H2AX immunoreactivity in villi, no aberrant foci indicative of transformation were evident. Lastly, these findings do not support a MOA for intestinal carcinogenesis involving direct Cr-DNA interaction in intestinal stem cells, but rather support a non-mutagenic MOA involving chronic wounding of intestinal villi and crypt cell hyperplasia.« less

Synchrotron-Based Imaging of Chromium and γ-H2AX Immunostaining in the Duodenum Following Repeated Exposure to Cr(VI) in Drinking Water

PubMed Central

Thompson, Chad M.; Seiter, Jennifer; Chappell, Mark A.; Tappero, Ryan V.; Proctor, Deborah M.; Suh, Mina; Wolf, Jeffrey C.; Haws, Laurie C.; Vitale, Rock; Mittal, Liz; Kirman, Christopher R.; Hays, Sean M.; Harris, Mark A.

2015-01-01

Current drinking water standards for chromium are for the combined total of both hexavalent and trivalent chromium (Cr(VI) and Cr(III)). However, recent studies have shown that Cr(III) is not carcinogenic to rodents, whereas mice chronically exposed to high levels of Cr(VI) developed duodenal tumors. These findings may suggest the need for environmental standards specific for Cr(VI). Whether the intestinal tumors arose through a mutagenic or non-mutagenic mode of action (MOA) greatly impacts how drinking water standards for Cr(VI) are derived. Herein, X-ray fluorescence (spectro)microscopy (µ-XRF) was used to image the Cr content in the villus and crypt regions of duodena from B6C3F1 mice exposed to 180 mg/l Cr(VI) in drinking water for 13 weeks. DNA damage was also assessed by γ-H2AX immunostaining. Exposure to Cr(VI) induced villus blunting and crypt hyperplasia in the duodenum—the latter evidenced by lengthening of the crypt compartment by ∼2-fold with a concomitant 1.5-fold increase in the number of crypt enterocytes. γ-H2AX immunostaining was elevated in villi, but not in the crypt compartment. µ-XRF maps revealed mean Cr levels >30 times higher in duodenal villi than crypt regions; mean Cr levels in crypt regions were only slightly above background signal. Despite the presence of Cr and elevated γ-H2AX immunoreactivity in villi, no aberrant foci indicative of transformation were evident. These findings do not support a MOA for intestinal carcinogenesis involving direct Cr-DNA interaction in intestinal stem cells, but rather support a non-mutagenic MOA involving chronic wounding of intestinal villi and crypt cell hyperplasia. PMID:25352572

Synchrotron-based imaging of chromium and  γ-H2AX immunostaining in the duodenum following repeated exposure to Cr(VI) in drinking water

DOE PAGES

Thompson, Chad M.; Seiter, Jennifer; Chappell, Mark A.; ...

2014-10-28

Current drinking water standards for chromium are for the combined total of both hexavalent and trivalent chromium (Cr(VI) and Cr(III)). However, recent studies have shown that Cr(III) is not carcinogenic to rodents, whereas mice chronically exposed to high levels of Cr(VI) developed duodenal tumors. These findings may suggest the need for environmental standards specific for Cr(VI). Whether the intestinal tumors arose through a mutagenic or non-mutagenic mode of action (MOA) greatly impacts how drinking water standards for Cr(VI) are derived. Herein, X-ray fluorescence (spectro)microscopy (µ-XRF) was used to image the Cr content in the villus and crypt regions of duodenamore » from B6C3F1 mice exposed to 180 mg/l Cr(VI) in drinking water for 13 weeks. DNA damage was also assessed by γ-H2AX immunostaining. Exposure to Cr(VI) induced villus blunting and crypt hyperplasia in the duodenum—the latter evidenced by lengthening of the crypt compartment by ~2-fold with a concomitant 1.5-fold increase in the number of crypt enterocytes. γ-H2AX immunostaining was elevated in villi, but not in the crypt compartment. µ-XRF maps revealed mean Cr levels >30 times higher in duodenal villi than crypt regions; mean Cr levels in crypt regions were only slightly above background signal. Despite the presence of Cr and elevated γ-H2AX immunoreactivity in villi, no aberrant foci indicative of transformation were evident. Lastly, these findings do not support a MOA for intestinal carcinogenesis involving direct Cr-DNA interaction in intestinal stem cells, but rather support a non-mutagenic MOA involving chronic wounding of intestinal villi and crypt cell hyperplasia.« less

Cold-Induced Thermogenesis and Inflammation-Associated Cold-Seeking Behavior Are Represented by Different Dorsomedial Hypothalamic Sites: A Three-Dimensional Functional Topography Study in Conscious Rats

PubMed Central

Shimansky, Yury P.; Oliveira, Daniela L.; Eales, Justin R.; Coimbra, Cândido C.

2017-01-01

In the past, we showed that large electrolytic lesions of the dorsomedial hypothalamus (DMH) promoted hypothermia in cold-exposed restrained rats, but attenuated hypothermia in rats challenged with a high dose of bacterial lipopolysaccharide (LPS) in a thermogradient apparatus. The goal of this study was to identify the thermoeffector mechanisms and DMH representation of the two phenomena and thus to understand how the same lesion could produce two opposite effects on body temperature. We found that the permissive effect of large electrolytic DMH lesions on cold-induced hypothermia was due to suppressed thermogenesis. DMH-lesioned rats also could not develop fever autonomically: they did not increase thermogenesis in response to a low, pyrogenic dose of LPS (10 μg/kg, i.v.). In contrast, changes in thermogenesis were uninvolved in the attenuation of the hypothermic response to a high, shock-inducing dose of LPS (5000 μg/kg, i.v.); this attenuation was due to a blockade of cold-seeking behavior. To compile DMH maps for the autonomic cold defense and for the cold-seeking response to LPS, we studied rats with small thermal lesions in different parts of the DMH. Cold thermogenesis had the highest representation in the dorsal hypothalamic area. Cold seeking was represented by a site at the ventral border of the dorsomedial nucleus. Because LPS causes both fever and hypothermia, we originally thought that the DMH contained a single thermoregulatory site that worked as a fever–hypothermia switch. Instead, we have found two separate sites: one that drives thermogenesis and the other, previously unknown, that drives inflammation-associated cold seeking. SIGNIFICANCE STATEMENT Cold-seeking behavior is a life-saving response that occurs in severe systemic inflammation. We studied this behavior in rats with lesions in the dorsomedial hypothalamus (DMH) challenged with a shock-inducing dose of bacterial endotoxin. We built functional maps of the DMH and found the strongest representation of cold-seeking behavior at the ventral border of the dorsomedial nucleus. We also built maps for cold-induced thermogenesis in unanesthetized rats and found the dorsal hypothalamic area to be its main representation site. Our work identifies the neural substrate of cold-seeking behavior in systemic inflammation and expands the functional topography of the DMH, a structure that modulates autonomic, endocrine, and behavioral responses and is a potential therapeutic target in anxiety and panic disorders. PMID:28630253

Cold-Induced Thermogenesis and Inflammation-Associated Cold-Seeking Behavior Are Represented by Different Dorsomedial Hypothalamic Sites: A Three-Dimensional Functional Topography Study in Conscious Rats.

PubMed

Wanner, Samuel P; Almeida, M Camila; Shimansky, Yury P; Oliveira, Daniela L; Eales, Justin R; Coimbra, Cândido C; Romanovsky, Andrej A

2017-07-19

In the past, we showed that large electrolytic lesions of the dorsomedial hypothalamus (DMH) promoted hypothermia in cold-exposed restrained rats, but attenuated hypothermia in rats challenged with a high dose of bacterial lipopolysaccharide (LPS) in a thermogradient apparatus. The goal of this study was to identify the thermoeffector mechanisms and DMH representation of the two phenomena and thus to understand how the same lesion could produce two opposite effects on body temperature. We found that the permissive effect of large electrolytic DMH lesions on cold-induced hypothermia was due to suppressed thermogenesis. DMH-lesioned rats also could not develop fever autonomically: they did not increase thermogenesis in response to a low, pyrogenic dose of LPS (10 μg/kg, i.v.). In contrast, changes in thermogenesis were uninvolved in the attenuation of the hypothermic response to a high, shock-inducing dose of LPS (5000 μg/kg, i.v.); this attenuation was due to a blockade of cold-seeking behavior. To compile DMH maps for the autonomic cold defense and for the cold-seeking response to LPS, we studied rats with small thermal lesions in different parts of the DMH. Cold thermogenesis had the highest representation in the dorsal hypothalamic area. Cold seeking was represented by a site at the ventral border of the dorsomedial nucleus. Because LPS causes both fever and hypothermia, we originally thought that the DMH contained a single thermoregulatory site that worked as a fever-hypothermia switch. Instead, we have found two separate sites: one that drives thermogenesis and the other, previously unknown, that drives inflammation-associated cold seeking. SIGNIFICANCE STATEMENT Cold-seeking behavior is a life-saving response that occurs in severe systemic inflammation. We studied this behavior in rats with lesions in the dorsomedial hypothalamus (DMH) challenged with a shock-inducing dose of bacterial endotoxin. We built functional maps of the DMH and found the strongest representation of cold-seeking behavior at the ventral border of the dorsomedial nucleus. We also built maps for cold-induced thermogenesis in unanesthetized rats and found the dorsal hypothalamic area to be its main representation site. Our work identifies the neural substrate of cold-seeking behavior in systemic inflammation and expands the functional topography of the DMH, a structure that modulates autonomic, endocrine, and behavioral responses and is a potential therapeutic target in anxiety and panic disorders. Copyright © 2017 Wanner et al.

Identification of flat dysplastic aberrant crypt foci in the colon of azoxymethane-treated A/J mice.

PubMed

Paulsen, Jan Erik; Knutsen, Helle; Ølstørn, Hege Benedikte; Løberg, Else Marit; Alexander, Jan

2006-02-01

The role of aberrant crypt foci (ACF) as preneoplastic lesions in colon carcinogenesis is not clear. In Min/+ mice and their wild-type littermates treated with azoxymethane (AOM), we previously identified a subgroup of flat ACF that seem more immediate precursors of tumors than the classical elevated ACF. In the present study, we identified a similar subgroup of flat ACF in AOM-treated A/J mice and compared them with nascent tumors and classical elevated ACF. At week 1 and 2 after birth, A/J mice were injected subcutaneously with AOM (10 mg/kg bw/injection). At weeks 7-14, we examined the luminal surface of unsectioned colon preparations stained with methylene blue in the inverse light microscope. The lesions were also examined by histopathology and immunohistochemistry. Surface examination revealed flat ACF, classical elevated ACF and nascent tumors. Since flat ACF were not observed as elevated structures, their bright blue appearance and compressed pit pattern of crypt openings seen with transillumination were used as criteria for their identification. Flat ACF and nascent tumors displayed a uniform picture of severe dysplasia, compressed pit pattern, overexpression of cytoplasmic/nuclear beta-catenin and nuclear overexpression of cyclin D1. Apparently, flat ACF and tumors represented the same type of dysplastic lesions at different stages of crypt multiplication. In contrast, classical elevated ACF did not seem to be as clearly related to tumorigenesis. They infrequently (1/20) possessed severe dysplasia, overexpression of cytoplasmic/nuclear beta-catenin, or nuclear overexpression of cyclin D1, and they did not have compressed crypt openings. Furthermore, flat ACF grew significantly faster than classical elevated ACF. In conclusion, our data indicate a development from flat ACF to adenoma characterized by aberrant activation of the Wnt signaling pathway and fast crypt multiplication. Classical elevated ACF do not seem to be as closely related to tumorigenesis. Copyright 2005 Wiley-Liss, Inc.

Dolastatin 15, a mollusk linear peptide, and Celecoxib, a selective cyclooxygenase-2 inhibitor, prevent preneoplastic colonic lesions and induce apoptosis through inhibition of the regulatory transcription factor NF-κB and an inflammatory protein, iNOS.

PubMed

Piplani, Honit; Vaish, Vivek; Sanyal, Sankar Nath

2012-11-01

The marine ecosystem is a unique and enormously rich source of natural products with potential chemopreventive applications in cancer. In the present study, we explored the chemopreventive role and the molecular mechanism of Dolastatin, a linear peptide from an Indian Ocean mollusk, and Celecoxib, a well-established cyclooxygenase-2 (COX-2) inhibitor in an individual as well as in a combination regimen in 1,2-dimethylhydrazine dihydrochloride (DMH)-induced colon carcinogenesis in a rat model. After a 6-week treatment with DMH, morphological analysis revealed a marked occurrence of preneoplastic features in the colonic mucosa, whereas histologically well-characterized dysplasia and hyperplasia were observed in DMH-treated animals. Simultaneous administration of Celecoxib and Dolastatin reduced these features significantly. DMH treatment affected the number of apoptotic cells in colonic enterocytes, which reverted to the normal level with the use of Celecoxib and Dolastatin. Inflammation remains the dominant molecular mechanism in the development of multiple plaque lesions, the carcinogenic lesions in a DMH-induced process that may be mediated by COX-2. Western blot and immunofluorescence analysis revealed a higher expression of COX-2 and nuclear factor-κB, the transcription factors responsible for proinflammatory proteins such as TNFα, and also the inducible nitric oxide synthase in the DMH group, which was further recovered significantly with the use of Celecoxib and Dolastatin. In-silico molecular docking analysis of Dolastatin as a ligand with various regulatory proteins suggests that although the peptide failed to dock to COX-2, it successfully did so with inducible nitric oxide synthase, thereby indicating the potential of this inflammatory protein as a molecular anticancer target in colon carcinogenesis.

Radioprotection of 1,2-dimethylhydrazine-initiated colon cancer in rats using low-dose γ rays by modulating multidrug resistance-1, cytokeratin 20, and β-catenin expression.

PubMed

Nabil, H M; Hassan, B N; Tohamy, A A; Waaer, H F; Abdel Moneim, A E

2016-03-01

Ionizing radiation is a widely used therapy for solid tumors. However, high-dose ionizing radiation causes apoptosis, transforms normal cells into tumor cells, and impairs immune functions, leading to the defects in the removal of damaged or tumor cells. In contrast, low-dose radiation has been reported to exert various beneficial effects in cells. This experimental study investigated the effect of γ rays at low dose on the development of colorectal tumor in a 1,2-dimethylhydrazine (DMH)-induced colon cancer. Colorectal tumor model was induced in Wistar rats by subcutaneous injection of DMH (20 mg/kg) once a week for 15 weeks. Starting from zero day of DMH injection, a single low dose of whole-body γ irradiation of 0.5 Gy/week was applied to the rats. A significant reduction in lipid peroxidation, nitric oxide, and elevation in the glutathione content and antioxidant enzyme activity (superoxide dismutase and catalase) were observed after γ irradiation comparing with DMH group. Moreover, γ ray reduced the expressions of multidrug resistance 1 (MDR1), β-catenin, and cytokeratin 20 (CK20) those increased in DMH-treated rats. However, survivin did not change with γ ray treatment. A histopathological examination of the DMH-injected rats revealed ulcerative colitis, dysplasia, anaplasia, and hyperchromasia. An improvement in the histopathological picture was seen in the colon of rats exposed to γ rays. In conclusion, the present results showed that low-dose γ ray significantly inhibited DMH-induced colon carcinogenesis in rats by modulating CK20, MDR1, and β-catenin expression but not survivin expression. © The Author(s) 2015.

Carborundum, a bulk similar to dietary fibers but chemically inert, does not decrease colon carcinogenesis.

PubMed

Corpet, D E; Taché, S; Peiffer, G

1997-03-19

Dietary fibers might lower the risk of colorectal cancer, maybe because of their bulking effect. We tested the protection afforded by an inert bulk against carcinogenesis. Thirty rats received an azoxymethane injection and were allocated to a control diet, or to a diet supplemented with 10% carborundum. After 100 days the colons were scored for aberrant crypt foci. Compared to controls, the fecal weight was doubled in carborundum-fed rats (P < 0.001), but the aberrant crypt foci multiplicity was not changed (P = 0.92). The results do not support the hypothesis that intestinal dilution by an inert bulk can protect against colon cancer.

Effects of dark chocolate on azoxymethane-induced colonic aberrant crypt foci.

PubMed

Hong, Mee Young; Nulton, Emily; Shelechi, Mahshid; Hernández, Lisa M; Nemoseck, Tricia

2013-01-01

Epidemiologic evidence supports that diets rich in polyphenols promote health and may delay the onset of colon cancer. Cocoa and chocolate products have some of the highest polyphenolic concentrations compared to other polyphenolic food sources. This study tested the hypothesis that a diet including dark chocolate can protect against colon cancer by inhibiting aberrant crypt foci (ACF) formation, downregulating gene expression of inflammatory mediators, and favorably altering cell kinetics. We also investigated whether bloomed dark chocolate retains the antioxidant capacity and protects against colon cancer. Forty-eight rats received either a diet containing control (no chocolate), regular dark chocolate, or bloomed dark chocolate and were injected subcutaneously with saline or azoxymethane. Relative to control, both regular and bloomed dark chocolate diets lowered the total number of ACF (P = 0.022). Chocolate diet-fed animals downregulated transcription levels of COX-2 (P = 0.035) and RelA (P = 0.045). Both chocolate diets lowered the proliferation index (P = 0.001). These results suggest that a diet including dark chocolate can reduce cell proliferation and some gene expression involving inflammation, which may explain the lower number of early preneoplastic lesions. These results provide new insight on polyphenol-rich chocolate foods and colon cancer prevention.

Characterization of Epithelial Progenitors in Normal Human Palatine Tonsils and Their HPV16 E6/E7-Induced Perturbation

PubMed Central

Kang, Sung Yoon Catherine; Kannan, Nagarajan; Zhang, Lewei; Martinez, Victor; Rosin, Miriam P.; Eaves, Connie J.

2015-01-01

Summary Human palatine tonsils are oropharyngeal lymphoid tissues containing multiple invaginations (crypts) in which the continuity of the outer surface epithelium is disrupted and the isolated epithelial cells intermingle with other cell types. We now show that primitive epithelial cells detectable in vitro in 2D colony assays and in a 3D culture system are CD44+NGFR+ and present in both surface and crypt regions. Transcriptome analysis indicated a high similarity between CD44+NGFR+ cells in both regions, although those isolated from the crypt contained a higher proportion of the most primitive (holo)clonogenic cells. Lentiviral transduction of CD44+NGFR+ cells from both regions with human papillomavirus 16-encoded E6/E7 prolonged their growth in 2D cultures and caused aberrant differentiation in 3D cultures. Our findings therefore reveal a shared, site-independent, hierarchical organization, differentiation potential, and transcriptional profile of normal human tonsillar epithelial progenitor cells. They also introduce a new model for investigating the mechanisms of their transformation. PMID:26527383

Loss of dorsomedial hypothalamic GLP-1 signaling reduces BAT thermogenesis and increases adiposity.

PubMed

Lee, Shin J; Sanchez-Watts, Graciela; Krieger, Jean-Philippe; Pignalosa, Angelica; Norell, Puck N; Cortella, Alyssa; Pettersen, Klaus G; Vrdoljak, Dubravka; Hayes, Matthew R; Kanoski, Scott; Langhans, Wolfgang; Watts, Alan G

2018-05-01

Glucagon-like peptide-1 (GLP-1) neurons in the hindbrain densely innervate the dorsomedial hypothalamus (DMH), a nucleus strongly implicated in body weight regulation and the sympathetic control of brown adipose tissue (BAT) thermogenesis. Therefore, DMH GLP-1 receptors (GLP-1R) are well placed to regulate energy balance by controlling sympathetic outflow and BAT function. We investigate this possibility in adult male rats by using direct administration of GLP-1 (0.5 ug) into the DMH, knocking down DMH GLP-1R mRNA with viral-mediated RNA interference, and by examining the neurochemical phenotype of GLP-1R expressing cells in the DMH using in situ hybridization. GLP-1 administered into the DMH increased BAT thermogenesis and hepatic triglyceride (TG) mobilization. On the other hand, Glp1r knockdown (KD) in the DMH increased body weight gain and adiposity, with a concomitant reduction in energy expenditure (EE), BAT temperature, and uncoupling protein 1 (UCP1) expression. Moreover, DMH Glp1r KD induced hepatic steatosis, increased plasma TG, and elevated liver specific de-novo lipogenesis, effects that collectively contributed to insulin resistance. Interestingly, DMH Glp1r KD increased neuropeptide Y (NPY) mRNA expression in the DMH. GLP-1R mRNA in the DMH, however, was found in GABAergic not NPY neurons, consistent with a GLP-1R-dependent inhibition of NPY neurons that is mediated by local GABAergic neurons. Finally, DMH Glp1r KD attenuated the anorexigenic effects of the GLP-1R agonist exendin-4, highlighting an important role of DMH GLP-1R signaling in GLP-1-based therapies. Collectively, our data show that DMH GLP-1R signaling plays a key role for BAT thermogenesis and adiposity. Copyright © 2018 The Authors. Published by Elsevier GmbH.. All rights reserved.

Activation of NF-κB: bridging the gap between inflammation and cancer in colitis-mediated colon carcinogenesis.

PubMed

Setia, Shruti; Nehru, Bimla; Sanyal, Sankar Nath

2014-02-01

Several studies have shown the anti-neoplastic effects of non-steroidal anti-inflammatory drugs (NSAIDs) on 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis, but how these drugs act in case of inflammation-augmented tumorigenesis is still not clear. The present study therefore designs an animal model of colitis-associated colon cancer where 3% Dextran sufate sodium (DSS) is used to develop ulcerative colitis and DMH treatment leads to colon carcinogenesis as early as in six weeks. Clinical symptoms for ulcerative colitis were studied using Disease Activity Index (DAI) while myeloperoxidase assay marked the neutrophil infiltration in DSS and DMH treated groups. The present results indicated the upregulation of the activity of inflammatory marker enzyme, cyclooxygenase-2 (cox-2) and pro-inflammatory cytokines such as TNF-α, IL-1β, IL-4 and IFN-γ with the treatment of DSS as well as DMH. The presence of cytokines in the inflammatory milieu might lead to the transformation of cytoplasmic inactive NF-κB (Nuclear Factor κB) to its active nuclear form, thereby leading to tumorigenesis. The administration of celecoxib along with DSS and DMH, revealed its chemopreventive efficacy in colitis as well as colon cancer. The effect of different doses of DMH on mouse colon was also investigated to obtain a minimum dose of DMH which can induce visible lesions in mice colons at a high incidence. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Leptin-receptor-expressing neurons in the dorsomedial hypothalamus and median preoptic area regulate sympathetic brown adipose tissue circuits.

PubMed

Zhang, Yan; Kerman, Ilan A; Laque, Amanda; Nguyen, Phillip; Faouzi, Miro; Louis, Gwendolyn W; Jones, Justin C; Rhodes, Chris; Münzberg, Heike

2011-02-02

Brown adipose tissue (BAT) thermogenesis is critical to maintain homoeothermia and is centrally controlled via sympathetic outputs. Body temperature and BAT activity also impact energy expenditure, and obesity is commonly associated with decreased BAT capacity and sympathetic tone. Severely obese mice that lack leptin or its receptor (LepRb) show decreased BAT capacity, sympathetic tone, and body temperature and thus are unable to adapt to acute cold exposure (Trayhurn et al., 1976). LepRb-expressing neurons are found in several hypothalamic sites, including the dorsomedial hypothalamus (DMH) and median preoptic area (mPOA), both critical sites to regulate sympathetic, thermoregulatory BAT circuits. Specifically, a subpopulation in the DMH/dorsal hypothalamic area (DHA) is stimulated by fever-inducing endotoxins or cold exposure (Dimicco and Zaretsky, 2007; Morrison et al., 2008). Using the retrograde, transsynaptic tracer pseudorabies virus (PRV) injected into the BAT of mice, we identified PRV-labeled LepRb neurons in the DMH/DHA and mPOA (and other sites), thus indicating their involvement in the regulation of sympathetic BAT circuits. Indeed, acute cold exposure induced c-Fos (as a surrogate for neuronal activity) in DMH/DHA LepRb neurons, and a large number of mPOA LepRb neurons project to the DMH/DHA. Furthermore, DMH/DHA LepRb neurons (and a subpopulation of LepRb mPOA neurons) project and synaptically couple to rostral raphe pallidus neurons, consistent with the current understanding of BAT thermoregulatory circuits from the DMH/DHA and mPOA (Dimicco and Zaretsky, 2007; Morrison et al., 2008). Thus, these data present strong evidence that LepRb neurons in the DMH/DHA and mPOA mediate thermoregulatory leptin action.

Brain circuits mediating baroreflex bradycardia inhibition in rats: an anatomical and functional link between the cuneiform nucleus and the periaqueductal grey

PubMed Central

Netzer, Florence; Bernard, Jean-François; Verberne, Anthony J M; Hamon, Michel; Camus, Françoise; Benoliel, Jean-Jacques; Sévoz-Couche, Caroline

2011-01-01

Abstract Defence responses triggered experimentally in rats by stimulation of the dorsomedial nucleus of the hypothalamus (DMH) and the dorsolateral periaqueductal grey matter (PAG) inhibit the cardiac baroreflex response (i.e. bradycardia). It has also been proposed that the midbrain cuneiform nucleus (CnF) is involved in active responses. Our aim was to identify the neurocircuitry involved in defence-induced baroreflex inhibition, with a particular focus on the link between DMH, CnF and dorsolateral PAG. Microinjection of the anterograde tracer Phaseolus vulgaris leucoaggutinin into the CnF revealed a dense projection to the dorsolateral PAG. Moreover, activation of neurons in the CnF induced increased expression of Fos protein in the dorsolateral PAG. Inhibition of neurons of the CnF or dorsolateral PAG prevented the inhibition of baroreflex bradycardia induced by DMH or CnF stimulation, respectively. These results provide a detailed description of the brain circuitry underlying acute baroreflex modulation by neurons of the DMH. Our data have shown for the first time that the CnF plays a key role in defence reaction-associated cardiovascular changes; its stimulation, from the DMH, activates the dorsolateral PAG, which, in turn, inhibits baroreflex bradycardia. PMID:21486808

Synchrotron-based imaging of chromium and γ-H2AX immunostaining in the duodenum following repeated exposure to Cr(VI) in drinking water.

PubMed

Thompson, Chad M; Seiter, Jennifer; Chappell, Mark A; Tappero, Ryan V; Proctor, Deborah M; Suh, Mina; Wolf, Jeffrey C; Haws, Laurie C; Vitale, Rock; Mittal, Liz; Kirman, Christopher R; Hays, Sean M; Harris, Mark A

2015-01-01

Current drinking water standards for chromium are for the combined total of both hexavalent and trivalent chromium (Cr(VI) and Cr(III)). However, recent studies have shown that Cr(III) is not carcinogenic to rodents, whereas mice chronically exposed to high levels of Cr(VI) developed duodenal tumors. These findings may suggest the need for environmental standards specific for Cr(VI). Whether the intestinal tumors arose through a mutagenic or non-mutagenic mode of action (MOA) greatly impacts how drinking water standards for Cr(VI) are derived. Herein, X-ray fluorescence (spectro)microscopy (µ-XRF) was used to image the Cr content in the villus and crypt regions of duodena from B6C3F1 mice exposed to 180 mg/l Cr(VI) in drinking water for 13 weeks. DNA damage was also assessed by γ-H2AX immunostaining. Exposure to Cr(VI) induced villus blunting and crypt hyperplasia in the duodenum--the latter evidenced by lengthening of the crypt compartment by ∼2-fold with a concomitant 1.5-fold increase in the number of crypt enterocytes. γ-H2AX immunostaining was elevated in villi, but not in the crypt compartment. µ-XRF maps revealed mean Cr levels >30 times higher in duodenal villi than crypt regions; mean Cr levels in crypt regions were only slightly above background signal. Despite the presence of Cr and elevated γ-H2AX immunoreactivity in villi, no aberrant foci indicative of transformation were evident. These findings do not support a MOA for intestinal carcinogenesis involving direct Cr-DNA interaction in intestinal stem cells, but rather support a non-mutagenic MOA involving chronic wounding of intestinal villi and crypt cell hyperplasia. © The Author 2014. Published by Oxford University Press on behalf of the Society of Toxicology.

Effects of Lactobacillus salivarius Ren on cancer prevention and intestinal microbiota in 1, 2-dimethylhydrazine-induced rat model.

PubMed

Zhang, Ming; Fan, Xing; Fang, Bing; Zhu, Chengzhen; Zhu, Jun; Ren, Fazheng

2015-06-01

Probiotics have been suggested as a prophylactic measure in colon cancer. The aim of this study was to investigate the impact of Lactobacillus salivarius Ren (Ren) in modulating colonic microbiota structure and colon cancer incidence in a rat model after injection with 1,2-dimethyl hydrazine (DMH). The results indicated that oral administration of Ren could effectively suppress DMH-induced colonic carcinogenesis. A significant decrease in cancer incidence (87.5% to 25%) was detected in rats fed with a dose of 5 × 10(10) CFU/kg bodyweight per day. Using denaturing gradient gel electrophoresis and Real-time PCR combined with multivariate statistical methods, we demonstrated that injection with DMH significantly altered the rat gut microbiota, while Ren counteracted these DMH-induced adverse effects and promoted reversion of the gut microbiota close to the healthy state. Tvalue biplots followed by band sequencing identified 21 bacterial strains as critical variables affected by DMH and Ren. Injection of DMH significantly increased the amount of Ruminococcus species (sp.) and Clostridiales bacteria, as well as decreasing the Prevotella sp. Administration of Ren reduced the amount of Ruminococcus sp., Clostridiales bacteria, and Bacteroides dorei, and increased the amount of Prevotella. Real-time PCR results were consistent with the results derived by t-value biplots. These findings suggested that Ren is a potential agent for colon cancer prevention. In conclusion, the results in the present study suggest a potential therapeutic approach based on the modulation of intestinal microflora by probiotics may be beneficial in the prevention of colorectal carcinogenesis.

Microinjection of muscimol into caudal periaqueductal gray lowers body temperature and attenuates increases in temperature and activity evoked from the dorsomedial hypothalamus.

PubMed

de Menezes, Rodrigo C A; Zaretsky, Dmitry V; Fontes, Marco A P; DiMicco, Joseph A

2006-05-30

Microinjection of the neuronal inhibitor muscimol into the midbrain lateral/dorsolateral periaqueductal gray (l/dlPAG) suppresses increases in heart rate (HR) and mean arterial pressure (MAP) evoked by microinjection of the GABA(A) receptor antagonist bicuculline methiodide (BMI) into the dorsomedial hypothalamus (DMH) in rats. Injection of BMI into the DMH also increases body temperature (Tco) and motor activity. Here, our goal was to extend previous findings by examining the effect of microinjection of muscimol into the PAG on these thermogenic and behavioral responses in conscious freely moving rats. Microinjection of muscimol (300 pmol and 1 nmol) alone into the l/dlPAG reduced baseline Tco without affecting activity, HR, or MAP. Similar injection of a dose that failed to alter baseline Tco (100 pmol) suppressed the increases in Tco evoked from the DMH and significantly attenuated DMH-induced increases in locomotor activity. Whereas microinjection of 1 nmol muscimol into the ldlPAG abolished the increases in Tco evoked from the DMH and in fact lowered body temperature to a degree similar to that seen after this dose of muscimol alone, 1 nmol muscimol at adjacent sites outside the targeted region of the PAG had no significant effect on DMH-induced increases in Tco or any other parameter. These results indicate a role for neuronal activity in the l/dlPAG in (1) the temperature and behavioral responses to disinhibition of neurons in the DMH, and (2) the maintenance of basal body temperature in conscious freely moving rats.

DMH1, a Highly Selective Small Molecule BMP Inhibitor Promotes Neurogenesis of hiPSCs: Comparison of PAX6 and SOX1 Expression during Neural Induction

PubMed Central

2012-01-01

Recent successes in deriving human-induced pluripotent stem cells (hiPSCs) allow for the possibility of studying human neurons derived from patients with neurological diseases. Concomitant inhibition of the BMP and TGF-β1 branches of the TGF-β signaling pathways by the endogenous antagonist, Noggin, and the small molecule SB431542, respectively, induces efficient neuralization of hiPSCs, a method known as dual-SMAD inhibition. The use of small molecule inhibitors instead of their endogenous counterparts has several advantages including lower cost, consistent activity, and the maintenance of xeno-free culture conditions. We tested the efficacy of DMH1, a highly selective small molecule BMP-inhibitor for its potential to replace Noggin in the neuralization of hiPSCs. We compare Noggin and DMH1-induced neuralization of hiPSCs by measuring protein and mRNA levels of pluripotency and neural precursor markers over a period of seven days. The regulation of five of the six markers assessed was indistinguishable in the presence of concentrations of Noggin or DMH1 that have been shown to effectively inhibit BMP signaling in other systems. We observed that by varying the DMH1 or Noggin concentration, we could selectively modulate the number of SOX1 expressing cells, whereas PAX6, another neural precursor marker, remained the same. The level and timing of SOX1 expression have been shown to affect neural induction as well as neural lineage. Our observations, therefore, suggest that BMP-inhibitor concentrations need to be carefully monitored to ensure appropriate expression levels of all transcription factors necessary for the induction of a particular neuronal lineage. We further demonstrate that DMH1-induced neural progenitors can be differentiated into β3-tubulin expressing neurons, a subset of which also express tyrosine hydroxylase. Thus, the combined use of DMH1, a highly specific BMP-pathway inhibitor, and SB431542, a TGF-β1-pathway specific inhibitor, provides us with the tools to independently regulate these two pathways through the exclusive use of small molecule inhibitors. PMID:22860217

Overnight Fasting Regulates Inhibitory Tone to Cholinergic Neurons of the Dorsomedial Nucleus of the Hypothalamus

PubMed Central

Groessl, Florian; Jeong, Jae Hoon; Talmage, David A.; Role, Lorna W.; Jo, Young-Hwan

2013-01-01

The dorsomedial nucleus of the hypothalamus (DMH) contributes to the regulation of overall energy homeostasis by modulating energy intake as well as energy expenditure. Despite the importance of the DMH in the control of energy balance, DMH-specific genetic markers or neuronal subtypes are poorly defined. Here we demonstrate the presence of cholinergic neurons in the DMH using genetically modified mice that express enhanced green florescent protein (eGFP) selectively in choline acetyltransferase (Chat)-neurons. Overnight food deprivation increases the activity of DMH cholinergic neurons, as shown by induction of fos protein and a significant shift in the baseline resting membrane potential. DMH cholinergic neurons receive both glutamatergic and GABAergic synaptic input, but the activation of these neurons by an overnight fast is due entirely to decreased inhibitory tone. The decreased inhibition is associated with decreased frequency and amplitude of GABAergic synaptic currents in the cholinergic DMH neurons, while glutamatergic synaptic transmission is not altered. As neither the frequency nor amplitude of miniature GABAergic or glutamatergic postsynaptic currents is affected by overnight food deprivation, the fasting-induced decrease in inhibitory tone to cholinergic neurons is dependent on superthreshold activity of GABAergic inputs. This study reveals that cholinergic neurons in the DMH readily sense the availability of nutrients and respond to overnight fasting via decreased GABAergic inhibitory tone. As such, altered synaptic as well as neuronal activity of DMH cholinergic neurons may play a critical role in the regulation of overall energy homeostasis. PMID:23585854

Increased choline kinase activity in 1,2-dimethylhydrazine-induced rat colon cancer.

PubMed

Nakagami, K; Uchida, T; Ohwada, S; Koibuchi, Y; Morishita, Y

1999-11-01

Cancer cells acquire particular characteristics that benefit their proliferation. We previously reported that human colon cancers examined had increased choline kinase activity and phosphocholine levels. The elevated phosphocholine levels were in part due to both activation of choline kinase and increased choline kinase alpha protein levels. In this report, we analyzed choline kinase, which catalyzes the phosphorylation of choline to produce phosphocholine, in rat 1,2-dimethylhydrazine (DMH)-induced colon cancer. This study is the first to demonstrate increased choline kinase alpha enzymatic activity, protein levels, and mRNA levels in DMH-induced colon cancer as well as human colon cancer, although phosphocholine was not increased in DMH-induced rat cancer. The increase in the mRNA level was partly due to an increase in the transcription of the choline kinase alpha gene. The increased choline kinase activity may be a specific characteristic acquired by cancer cells that benefits their proliferation.

Butyrate and bioactive proteolytic form of Wnt-5a regulate colonic epithelial proliferation and spatial development

PubMed Central

Uchiyama, Kazuhiko; Sakiyama, Toshio; Hasebe, Takumu; Musch, Mark W.; Miyoshi, Hiroyuki; Nakagawa, Yasushi; He, Tong-Chuan; Lichtenstein, Lev; Naito, Yuji; Itoh, Yoshito; Yoshikawa, Toshikazu; Jabri, Bana; Stappenbeck, Thaddeus; Chang, Eugene B.

2016-01-01

Proliferation and spatial development of colonic epithelial cells are highly regulated along the crypt vertical axis, which, when perturbed, can result in aberrant growth and carcinogenesis. In this study, two key factors were identified that have important and counterbalancing roles regulating these processes: pericrypt myofibroblast-derived Wnt-5a and the microbial metabolite butyrate. Cultured YAMC cell proliferation and heat shock protein induction were analzyed after butryate, conditioned medium with Wnt5a activity, and FrzB containing conditioned medium. In vivo studies to modulate Hsp25 employed intra-colonic wall Hsp25 encoding lentivirus. To silence Wnt-5a in vivo, intra-colonic wall Wnt-5a silencing RNA was used. Wnt-5a, secreted by stromal myofibroblasts of the lower crypt, promotes proliferation through canonical β-catenin activation. Essential to this are two key requirements: (1) proteolytic conversion of the highly insoluble ~40 kD Wnt-5a protein to a soluble 36 mer amino acid peptide that activates epithelial β-catenin and cellular proliferation, and (2) the simultaneous inhibition of butyrate-induced Hsp25 by Wnt-5a which is necessary to arrest the proliferative process in the upper colonic crypt. The interplay and spatial gradients of these factors insures that crypt epithelial cell proliferation and development proceed in an orderly fashion, but with sufficient plasticity to adapt to physiological perturbations including inflammation. PMID:27561676

Influence of dietary fiber from coconut kernel (Cocos nucifera) on the 1,2-dimethylhydrazine-induced lipid peroxidation in rats.

PubMed

Pillai, M G; Thampi, B S; Menon, V P; Leelamma, S

1999-09-01

The influence of dietary fiber from coconut kernel isolated by the neutral detergent fiber method on the antioxidant status in rats treated with the colon specific carcinogen 1,2-dimethylhydrazine (DMH) was studied in rats fed a high-fat diet for 15 weeks. The DMH-treated fiber group showed higher levels of lipid peroxides than the control group treated with DMH at the preneoplastic and neoplastic stages. Free fatty acid levels were found to decrease significantly in the DMH-treated control group, whereas it was near normal in the fiber groups. Superoxide dismutase and catalase activity also were found to be increased in the liver, intestine, proximal colon, and distal colon. Glutathione levels in all the tissues studied showed significant decreases in the fiber group. The results suggest that coconut kernel fiber can protect cells from loss of oxidative capacity with the administration of the procarcinogen DMH.

Lactobacillus rhamnosus ATCC 7469 exopolysaccharides synergizes with low level ionizing radiation to modulate signaling molecular targets in colorectal carcinogenesis in rats.

PubMed

Zahran, Walid E; Elsonbaty, Sawsan M; Moawed, Fatma S M

2017-08-01

Combination therapy that targets cellular signaling pathway represents an alternative therapy for the treatment of colon cancer (CRC). The present study was therefore aimed to investigate the probable interaction of Lactobacillus rhamnosus ATCC 7469 exopolysaccharides (EPS) with low level ionizing γ radiation (γ-R) exposure against dimethylhydrazine (DMH)- induced colorectal carcinogenesis in rats. Colon cancer was induced with 20mg DMH/kg BW. Rats received daily by gastric gavage 100mg EPS/Kg BW concomitant with 1Gy γ-R over two months. Colonic oxidative and inflammatory stresses were assessed. The change in the expression of p-p38 MAPK, p-STAT3, β-catenin, NF-kB, COX-2 and iNOS was evaluated by western blotting and q-PCR. It was found that DMH treatment significantly induced colon oxidative injury accompanied by inflammatory disturbance along with increased protein expression of the targeted signaling factors p-p38 MAPK, p-STAT3 and β-catenin. The mRNA gene expression of NF-kB, COX-2 and iNOS was significantly higher in DMH-treated animals. It's worthy to note that colon tissues with DMH treatment showed significant dysplasia and anaplasia of the glandular mucosal lining epithelium with loses of goblet cells formation, pleomorphism in the cells and hyperchromachia in nuclei. Interestingly, EPS treatment with γ-R exposure showed statistically significant amelioration of the oxidative and inflammatory biomarkers with modulated signaling molecular factors accompanied by improved histological structure against DMH-induced CRC. In conclusion, our findings showed that Lactobacillus rhamnosus ATCC 7469 EPS with low level γ-R in synergistic interaction are efficacious control against CRC progression throughout the modulation of key signaling growth factors associated with inflammation via antioxidant mediated anti-inflammatory and anti-proliferative activities. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Feeding of soy protein isolate to rats during pregnancy and lactation suppresses formation of aberrant crypt foci in their progeny's colons: interaction of diet with fetal alcohol exposure

PubMed Central

Linz, Amanda L; Xiao, Rijin; Parker, James G; Simpson, Pippa M; Badger, Thomas M; Simmen, Frank A

2004-01-01

Soy protein isolate (SPI) in the diet may inhibit colon tumorigenesis. We examined azoxymethane (AOM)-induced aberrant crypt foci (ACF) in male rats in relation to lifetime, pre-weaning, or post-weaning dietary exposure to SPI and also within the context of fetal alcohol exposure. Pregnant Sprague Dawley rats were fed AIN-93G diets containing casein (20%, the control diet) or SPI (20%) as the sole protein source starting on gestation day 4 (GD 4). Progeny were weaned on postnatal day (PND) 21 to the same diet as their dams and were fed this diet until termination of the experiment at PND 138. Rats received AOM on PND 89 and 96. Lifetime (GD 4 to PND 138) feeding of SPI led to reduced frequency of ACF with 4 or more crypts in the distal colon. Progeny of dams fed SPI only during pregnancy and lactation or progeny fed SPI only after weaning exhibited similarly reduced frequency of large ACF in distal colon. Number of epithelial cells, in the distal colon, undergoing apoptosis was unaffected by diet. SPI reduced weight gain and adiposity, but these were not correlated with fewer numbers of large ACF. Lifetime SPI exposure similarly inhibited development of large ACF in Sprague Dawley rats whose dams were exposed to ethanol during pregnancy. In summary, feeding of SPI to rat dams during pregnancy and lactation suppresses numbers of large ACF in their progeny, implying a long-term or permanent change elicited by the maternal diet. Moreover, results support the use of ACF as an intermediate endpoint for elucidating effects of SPI and its biochemical constituents in colon cancer prevention in rats. PMID:15488141

Chemoprevention of colon carcinogenesis by polyethylene glycol: suppression of epithelial proliferation via modulation of SNAIL/beta-catenin signaling.

PubMed

Roy, Hemant K; Kunte, Dhananjay P; Koetsier, Jennifer L; Hart, John; Kim, Young L; Liu, Yang; Bissonnette, Marc; Goldberg, Michael; Backman, Vadim; Wali, Ramesh K

2006-08-01

Polyethylene glycol (PEG) is one of the most potent chemopreventive agents against colorectal cancer; however, the mechanisms remain largely unexplored. In this study, we assessed the ability of PEG to target cyclin D1-beta-catenin-mediated hyperproliferation in the azoxymethane-treated rat model and the human colorectal cancer cell line, HT-29. Azoxymethane-treated rats were randomized to AIN-76A diet alone or supplemented with 5% PEG-8000. After 30 weeks, animals were euthanized and biopsies of aberrant crypt foci and uninvolved crypts were subjected to immunohistochemical and immunoblot analyses. PEG markedly suppressed both early and late markers of azoxymethane-induced colon carcinogenesis (fractal dimension by 80%, aberrant crypt foci by 64%, and tumors by 74%). In both azoxymethane-treated rats and HT-29 cells treated with 5% PEG-3350 for 24 hours, PEG decreased proliferation (45% and 52%, respectively) and cyclin D1 (78% and 56%, respectively). Because beta-catenin is the major regulator of cyclin D1 in colorectal cancer, we used the T-cell factor (Tcf)-TOPFLASH reporter assay to show that PEG markedly inhibited beta-catenin transcriptional activity. PEG did not alter total beta-catenin expression but rather its nuclear localization, leading us to assess E-cadherin expression (a major determinant of beta-catenin subcellular localization), which was increased by 73% and 71% in the azoxymethane-rat and HT-29 cells, respectively. We therefore investigated the effect of PEG treatment on levels of the negative regulator of E-cadherin, SNAIL, and observed a 50% and 75% decrease, respectively. In conclusion, we show, for the first time, a molecular mechanism through which PEG imparts its antiproliferative and hence profound chemopreventive effect.

Regulation of biokinetics of (65)Zn by curcumin and zinc in experimentally induced colon carcinogenesis in rats.

PubMed

Jain, Kinnri; Dhawan, Devinder K

2014-10-01

This study was conducted to investigate the role of curcumin and zinc on the biokinetics and biodistribution of (65)Zn during colon carcinogenesis. Male wistar rats were divided into five groups, namely normal control, 1,2-dimethylhydrazine (DMH) treated, DMH + curcumin treated, DMH + zinc treated, and DMH + curcumin + zinc treated. Weekly subcutaneous injections of DMH (30 mg/kg body weight) for 16 weeks initiated colon carcinogenesis. Curcumin (100 mg/kg body weight orally) and ZnSO4 (227 mg/L in drinking water) were supplemented for 16 weeks. This study revealed a significant depression in the fast (Tb1) and slow component (Tb2) of biological half-life of (65)Zn in the whole body of DMH-treated rats, whereas liver showed a significant elevation in these components. Further, DMH treatment showed a significant increase in the uptake values of (65)Zn in colon, small intestine, and kidneys. Subcellular distribution depicted a significant increase in (65)Zn uptake values in mitochondrial, microsomal, and postmicrosomal fractions of colon. However, curcumin and zinc supplementation when given separately or in combination reversed the trends and restored the uptake values close to normal range. Our study concludes that curcumin and zinc supplementation during colon carcinogenesis shall prove to be efficacious in regulating the altered zinc metabolism.

Overexpression of neuropeptide Y in the dorsomedial hypothalamus causes hyperphagia and obesity in rats.

PubMed

Zheng, Fenping; Kim, Yonwook J; Chao, Pei-Ting; Bi, Sheng

2013-06-01

We sought to determine a role for NPY overexpression in the dorsomedial hypothalamus (DMH) in obesity etiology using the rat model of adeno-associated virus (AAV)-mediated expression of NPY (AAVNPY) in the DMH. Rats received bilateral DMH injections of AAVNPY or control vector and were fed on regular chow. Five-week postviral injection, half the rats from each group were switched to access to a high-fat diet for another 11 weeks. We examined variables including body weight, food intake, energy efficiency, meal patterns, glucose tolerance, fat mass, plasma insulin, plasma leptin, and hypothalamic gene expression. Rats with DMH NPY overexpression had increased food intake and body weight and lowered metabolic efficiency. The hyperphagia was mediated through increased meal size during the dark. Although these rats had normal blood glucose, their plasma insulin levels were increased in both basal and glucose challenge conditions. While high-fat diet induced hyperphagia, obesity, and hyperinsulinemia, these effects were amplified in rats with DMH NPY overexpression. Arcuate Npy, agouti-related protein and proopiomelanocortin expression was appropriately regulated in response to positive energy balance. These results indicate that DMH NPY overexpression can cause hyperphagia and obesity and DMH NPY may have actions in glucose homeostasis. Copyright © 2013 The Obesity Society.

Aberrant epithelial GREM1 expression initiates colonic tumorigenesis from cells outside of the crypt base stem cell niche

PubMed Central

Bansal, Mukesh; Rafferty, Hannah; Boitsova, Tatjana; Bardella, Chiara; Jaeger, Emma; Lewis, Annabelle; Freeman-Mills, Luke; Giner, Francesc Castro; Rodenas-Cuadrado, Pedro; Mallappa, Sreelakshmi; Clark, Susan; Thomas, Huw; Jeffery, Rosemary; Poulsom, Richard; Rodriguez-Justo, Manuel; Novelli, Marco; Chetty, Runjan; Silver, Andrew; Sansom, Owen James; Greten, Florian R; Wang, Lai Mun; East, James Edward; Tomlinson, Ian; Leedham, Simon John

2015-01-01

Hereditary mixed polyposis syndrome (HMPS) is characterised by the development of mixed morphology colorectal tumours and is caused by a 40 kb duplication that results in aberrant epithelial expression of the mesenchymal Bone Morphogenetic Protein antagonist, GREM1. Here we use HMPS tissue and a mouse model of the disease to show that epithelial GREM1 disrupts homeostatic intestinal morphogen gradients, altering cell-fate, that is normally determined by position along the vertical epithelial axis. This promotes the persistence and/or reacquisition of stem-cell properties in Lgr5 negative (non-expressing) progenitor cells that have exited the stem-cell niche. These cells form ectopic crypts, proliferate, accumulate somatic mutations and can initiate intestinal neoplasia, indicating that the crypt base stem-cell is not the sole cell-of-origin of colorectal cancer. Furthermore, we show that epithelial expression of GREM1 also occurs in traditional serrated adenomas, sporadic pre-malignant lesions with a hitherto unknown pathogenesis and these lesions can be considered the sporadic equivalents of HMPS polyps. PMID:25419707

Planar cell polarity signaling in the uterus directs appropriate positioning of the crypt for embryo implantation

PubMed Central

Yuan, Jia; Cha, Jeeyeon; Deng, Wenbo; Bartos, Amanda; Sun, Xiaofei; Ho, Hsin-Yi Henry; Borg, Jean-Paul; Yamaguchi, Terry P.; Yang, Yingzi; Dey, Sudhansu K.

2016-01-01

Blastocyst implantation is a complex process requiring coordination of a dynamic sequence of embryo–uterine interactions. Blood vessels enter the uterus from the mesometrium, demarcating the uterus into mesometrial (M) and antimesometrial (AM) domains. Implantation occurs along the uterine longitudinal axis within specialized implantation chambers (crypts) that originate within the evaginations directed from the primary lumen toward the AM domain. The morphological orientation of crypts in rodent uteri was recognized more than a century ago, but the mechanism remained unknown. Here we provide evidence that planar cell polarity (PCP) signaling orchestrates directed epithelial evaginations to form crypts for implantation in mice. Uterine deletion of Vang-like protein 2, but not Vang-like protein 1, conferred aberrant PCP signaling, misdirected epithelial evaginations, defective crypt formation, and blastocyst attachment, leading to severely compromised pregnancy outcomes. The study reveals a previously unrecognized role for PCP in executing spatial cues for crypt formation and implantation. Because PCP is an evolutionarily conserved phenomenon, our study is likely to inspire implantation studies of this signaling pathway in humans and other species. PMID:27911818

Possible Protective Effects of Quercetin and Sodium Gluconate Against Colon Cancer Induction by Dimethylhydrazine in Mice.

PubMed

Saleem, T H; Attya, A M; Ahmed, E A; Ragab, S M M; Ali Abdallah, M A; Omar, H M

2015-01-01

Micronutrients in food have been found to have chemopreventive effects, supporting the conclusions from epidemiologie studies that consumption of fresh fruits and vegetables reduces cancer risk. The present study was carried out to evaluate the role of querctin (Q) and sodium gluconate (GNA) supplementation separately or in combination in ameliorating promotion of colon tumor development by dimethyl-hydrazine (DMH) in mice. Histopathological observation of colons in mice treated with DMH showed goblet cell dysplasia with inflammatory cell infiltration. This pathological finding was associated with significant alteration in oxidative stress markers in colon tissues and carcinoembryonic antigen (CEA) levels in plasma. Mice co-treated with GNA and Q showed mild changes of absorptive and goblet cells and inflammatory cell infiltration in lamina properia, with improvement in oxidative stress markers. In conclusion, findings of the present study indicate significant roles for reactive oxygen species (ROS) in pathogenesis of DMH-induced colon toxicity and initiation of colon cancer. Also, they suggest that Q, GNA or the combination of both have a positive beneficial effect against DMH induced colonic cancer induction in mice.

Efferent projections of NPY expressing neurons of the dorsomedial hypothalamus in chronic hyperphagic models

PubMed Central

Lee, Shin J.; Kirigiti, Melissa; Lindsley, Sarah R; Loche, Alberto; Madden, Christopher J.; Morrison, Shaun F.; Smith, M Susan; Grove, Kevin L.

2013-01-01

The dorsomedial hypothalamus (DMH) has long been implicated in feeding behavior and thermogenesis. The DMH contains orexigenic neuropeptide Y (NPY) neurons, but the role of these neurons in the control of energy homeostasis is not well understood. NPY expression in the DMH is low under normal conditions in adult rodents, but is significantly increased during chronic hyperphagic conditions such as lactation and diet-induced obesity (DIO). To better understand the role of DMH-NPY neurons, we characterized the efferent projections of DMH-NPY neurons using the anterograde tracer biotinylated dextran amine (BDA) in lactating rats and DIO mice. In both models, BDA and NPY co-labeled fibers were mainly limited to the hypothalamus including the paraventricular nucleus of the hypothalamus (PVH), lateral hypothalamus/perifornical area (LH/PFA), and anteroventral periventricular nucleus (AVPV). Specifically in lactating rats, BDA and NPY co-labeled axonal swellings were in close apposition to CART expressing neurons in the PVH and AVPV. Although the DMH neurons project to the rostral raphe pallidus (rRPa) these projections did not contain NPY immunoreactivity in either the lactating rat or DIO mouse. Instead, the majority of BDA-labeled fibers in the rRPa were orexin positive. Furthermore, DMH-NPY projections were not observed within the nucleus of the solitary tract (NTS), another brainstem site critical for the regulation of sympathetic outflow. The present data suggest that NPY expression in the DMH during chronic hyperphagic conditions plays important roles in feeding behavior and thermogenesis by modulating neuronal functions within the hypothalamus, but not in the brainstem. PMID:23172177

Dietary Ziziphus jujuba Fruit Influence on Aberrant Crypt Formation and Blood Cells in Colitis-Associated Colorectal Cancer in Mice.

PubMed

Periasamy, Srinivasan; Liu, Chung-Teng; Wu, Wang-Hung; Chien, Se-Ping; Liu, Ming-Yie

2015-01-01

Ziziphus jujuba (ZJ) fruit is rich in bioactive functional components such as polysaccharides, triterpenoid acid, flavonoids and oleamide. It has been commonly used in the treatment of various diseases including diabetes, digestive disorders, diarrhea, skin infections, liver and urinary complaints. However, dietary effects with regard to chemoprevention of colon cancer have not been studied. The present study was performed to evaluate the protective effects of dietary ZJ against colitis-associated colon carcinogenesis in azoxymethane (AOM)-dextran sodium sulphate (DSS)-treated mice. AOM was injected (10 mg/kg b.wt., i.p.) and three cycles of 2% DSS in drinking water for 7 days with 14 days of normal drinking water in-between were administered to induce colitis-associated colon cancer. ZJ fruit was supplemented into feed at levels of 5 and 10%. Dietary ZJ significantly attenuated aberrant crypt foci (ACF) formation and also decreased the progression of hyperplasia to dysplasia. In addition, it significantly reduced circulating white blood cells, lymphocytes, neutrophils, monocytes, eosinophils, basophils and platelets compared to colon cancer mice. We conclude that ZJ supplementation may delay the progression of colon cancer from hyperplasia to dysplasia and ultimately adenocarcinoma and cancer. In addition, it decreased circulating tumor-related leukocytes, main regulators of cancer inflammation. Dietary consumption of ZJ fruit attenuated the formation of ACF and delayed the progression of colon cancer.

Carvacrol exhibits anti-oxidant and anti-inflammatory effects against 1, 2-dimethyl hydrazine plus dextran sodium sulfate induced inflammation associated carcinogenicity in the colon of Fischer 344 rats.

PubMed

Arigesavan, Kaninathan; Sudhandiran, Ganapasam

2015-05-29

Chronic inflammation is one of the remarkable etiologic factors for various human ailments including cancer. The well known hypothesis is that persistent inflammation in colon can increase the risk of colorectal cancer (CRC). In this study, a pharmacological evaluation of carvacrol, a phenolic monoterpene constituent of essential oils produced from aromatic plant Oreganum vulgarea sp. on colitis associated colon cancer (CACC) induced by 1,2 Dimethylhydrazine (DMH) and dextran sodium sulfate (DSS) in male Fischer 344 rat model was studied. F344 rats were given three subcutaneous injections of DMH (40 mg/kg body wt) in the first week and were given free access to drinking water containing 1% DSS for the next one week followed by 7-14 days of water as three cycles. Carvacrol was administrated before and after tumor induction at a concentration of 50 mg/kg body weight (o.p). Carvacrol treated groups promotes the endogenous antioxidant system and suppress the inflammation in DMH/DSS induced animals. An increased antioxidant status and restoration of histological lesions in the inflamed colonic mucosa was observed in carvacrol treated rats. This effect was confirmed biochemically by reducing free-radical accumulation and suppressing expression of pro-inflammatory mediators. In this study, Carvacrol significantly increased the anti-oxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) glutathione (GSH) levels and reduced lipid peroxides (LPO), myeloperoxidase (MPO) and nitric oxide (NO) as compared to DMH/DSS induced rats. These dramatic changes facilitate the suppression of pro-inflammatory mediators such as inducible nitric oxide synthase (iNOS), and interleukin-1 beta (IL-1β) in CACC induced rats. Taken together, these findings suggest that Carvacrol may play a beneficial role in DMH/DSS induced experimental rat model and serve as an excellent dietary antioxidant as well as anti-inflammatory agent. It may represent novel therapeutic interventions against colon cancer triggered by chronic inflammation. Copyright © 2015 Elsevier Inc. All rights reserved.

Disinhibiting neurons in the dorsomedial hypothalamus delays the onset of exertional fatigue and exhaustion in rats exercising in a warm environment.

PubMed

Zaretsky, Dmitry V; Kline, Hannah; Zaretskaia, Maria V; Brown, Mary Beth; Durant, Pamela J; Alves, Nathan J; Rusyniak, Daniel E

2018-06-15

Stimulants cause hyperthermia, in part, by increasing heat generation through exercise. Stimulants also delay the onset of fatigue and exhaustion allowing animals to exercise longer. If used in a warm environment, this combination (increased exercise and decreased fatigue) can cause heat stroke. The dorsomedial hypothalamus (DMH) is involved in mediating locomotion from stimulants. Furthermore, inhibiting the DMH decreases locomotion and prevents hyperthermia in rats given stimulants in a warm environment. Whether the DMH is involved in mediating exercise-induced fatigue and exhaustion is not known. We hypothesized that disinhibiting neurons in the dorsomedial hypothalamus (DMH) would delay the onset of fatigue and exhaustion in animals exercising in a warm environment. To test this hypothesis, we used automated video tracking software to measure fatigue and exhaustion. In rats, using wearable mini-pumps, we demonstrated that disinhibiting the DMH, via bicuculline perfusion (5 µM), increased the duration of exercise in a warm environment as compared to control animals (25 ± 3 min vs 15 ± 2 min). Bicuculline-perfused animals also had higher temperatures at exhaustion (41.4 ± 0.2 °C vs 40.0 ± 0.4 °C). Disinhibiting neurons in the DMH also increased the time to fatigue. Our data show that the same region of the hypothalamus that is involved in mediating locomotion to stimulants, is also involved in controlling exhaustion and fatigue. These findings have implications for understanding the cause and treatment of stimulant-induced-hyperthermia. Copyright © 2018 Elsevier B.V. All rights reserved.

Blockade of TLR3 protects mice from lethal radiation-induced gastrointestinal syndrome

PubMed Central

Takemura, Naoki; Kawasaki, Takumi; Kunisawa, Jun; Sato, Shintaro; Lamichhane, Aayam; Kobiyama, Kouji; Aoshi, Taiki; Ito, Junichi; Mizuguchi, Kenji; Karuppuchamy, Thangaraj; Matsunaga, Kouta; Miyatake, Shoichiro; Mori, Nobuko; Tsujimura, Tohru; Satoh, Takashi; Kumagai, Yutaro; Kawai, Taro; Standley, Daron M.; Ishii, Ken J.; Kiyono, Hiroshi; Akira, Shizuo; Uematsu, Satoshi

2014-01-01

High-dose ionizing radiation induces severe DNA damage in the epithelial stem cells in small intestinal crypts and causes gastrointestinal syndrome (GIS). Although the tumour suppressor p53 is a primary factor inducing death of crypt cells with DNA damage, its essential role in maintaining genome stability means inhibiting p53 to prevent GIS is not a viable strategy. Here we show that the innate immune receptor Toll-like receptor 3 (TLR3) is critical for the pathogenesis of GIS. Tlr3−/− mice show substantial resistance to GIS owing to significantly reduced radiation-induced crypt cell death. Despite showing reduced crypt cell death, p53-dependent crypt cell death is not impaired in Tlr3−/− mice. p53-dependent crypt cell death causes leakage of cellular RNA, which induces extensive cell death via TLR3. An inhibitor of TLR3–RNA binding ameliorates GIS by reducing crypt cell death. Thus, we propose blocking TLR3 activation as a novel approach to treat GIS. PMID:24637670

Involvement of prelimbic medial prefrontal cortex in panic-like elaborated defensive behaviour and innate fear-induced antinociception elicited by GABAA receptor blockade in the dorsomedial and ventromedial hypothalamic nuclei: role of the endocannabinoid CB1 receptor.

PubMed

Freitas, Renato Leonardo de; Salgado-Rohner, Carlos José; Hallak, Jaime Eduardo Cecílio; Crippa, José Alexandre de Souza; Coimbra, Norberto Cysne

2013-09-01

It has been shown that GABAA receptor blockade in the dorsomedial and ventromedial hypothalamic nuclei (DMH and VMH, respectively) induces elaborated defensive behavioural responses accompanied by antinociception, which has been utilized as an experimental model of panic attack. Furthermore, the prelimbic (PL) division of the medial prefrontal cortex (MPFC) has been related to emotional reactions and the processing of nociceptive information. The aim of the present study was to investigate the possible involvement of the PL cortex and the participation of local cannabinoid CB1 receptors in the elaboration of panic-like reactions and in innate fear-induced antinociception. Elaborated fear-induced responses were analysed during a 10-min period in an open-field test arena. Microinjection of the GABAA receptor antagonist bicuculline into the DMH/VMH evoked panic-like behaviour and fear-induced antinociception, which was decreased by microinjection of the non-selective synaptic contact blocker cobalt chloride in the PL cortex. Moreover, microinjection of AM251 (25, 100 or 400 pmol), an endocannabinoid CB1 receptor antagonist, into the PL cortex also attenuated the defensive behavioural responses and the antinociception that follows innate fear behaviour elaborated by DMH/VMH. These data suggest that the PL cortex plays an important role in the organization of elaborated forward escape behaviour and that this cortical area is also involved in the elaboration of innate fear-induced antinociception. Additionally, CB1 receptors in the PL cortex modulate both panic-like behaviours and fear-induced antinociception elicited by disinhibition of the DMH/VMH through microinjection of bicuculline.

Effects of VPS extract of Coriolus versicolor on cancer of the large intestine using a serial sacrifice technique.

PubMed

Toth, Bela; Coles, Melissa; Lynch, James

2006-01-01

VPS, a hot water extract of the Coriolus versicolor mushroom, was given at a 2% dose level in the diet of female Swiss Webster CFW outbred mice in a serial sacrifice experiment. The mice were also administered either 1,2-dimethylhydrazine dihydrochloride (1,2-DMH) as ten weekly subcutaneous (s.c) injections of 20 microg/g body weight or physiological saline (PS) as ten weekly (s.c) injections of 0.01 ml/g body weight. The animals were sacrificed at 26 weeks or 35 weeks after the first injection of 1,2-DMH or PS. The number of mice with large intestinal tumors and the total number of these tumors were: Group I (1,2-DMH), 29 and 438; Group 2 (VPS + 1,2-DMH), 29 and 344; Group 3 (VPS + PS), 0 and 0; and Group 4 (PS), I and 1, in the mice sacrificed at 26 weeks. The corresponding tumor incidences in mice sacrificed at 35 weeks were: Group 1 (1,2-DMH), 30 and 323; Group 2 (VPS + 1,2-DMH), 29 and 521; Group 3 (VPS + PS), 1 and 2; and Group 4 (PS), 0 and 0. Histopathologically, the tumors were diagnosed as polypoid adenomas and adenocarcinomas of the cecum, colon and rectum. Contrary to expectations, the VPS treatment enhanced the development of large intestinal tumors induced by 1,2-DMH in animals sacrificed at 35 weeks after the first injection of the carcinogen.

The effectiveness of cyclooxygenase-2 inhibitors and evaluation of angiogenesis in the model of experimental colorectal cancer.

PubMed

Gungor, Hilal; Ilhan, Nevin; Eroksuz, Hatice

2018-06-01

Colorectal cancer (CRC) is an important cause of cancer-related deaths worldwide. Early diagnosis and treatment of CRCs are of importance for improving the survival. In the present study, we studied the effects of nonsteroidal anti-inflammatory drugs (NSAIDs)-induced chemopreventive effects on tumor development incidence and angiogenesis in experimental CRC rats. 1,2-Dimethylhydrazine dihydrochloride (DMH) was used as cancer-inducing agent and two NSAIDs (celecoxib and diclofenac) were given orally as chemopreventive agents. Histopathological and immuno histochemical evaluations were performed in colorectal tissue samples, whereas angiogenesis parameters were studied in blood samples. Histopathological examination showed that adenocarcinoma (62.5%), dysplastic changes (31.25%) and inflammattory changes (6.25%) were detected in DMH group, whereas no pathological change was observed in control rats. In treatment groups, there was marked decrease in adenocarcinoma rate (30% and 10%, respectively). A significant increase was detected in MMP-2, MMP-9 levels and MMP-2/TIMP-2 ratio in DMH group as compared with controls and treatment groups. In immunohistochemical evaluations, there was an increase in intensity and extent of staining of MMP-2 and MMP-9 in DMH group as compared to controls and treatment groups. The decrease in celecoxib group was more prominent. Overall, it was concluded that NSAIDs, particularly cyclooxygenase-2 (COX-2) inhibitors, might have a protective effect on CRC development and slow down progression of tumor in a DMH-induced experimental cancer model. One of the possible mechanisms in the chemoprevention of colon cancer seems to be inhibition of angiogenesis by diclofenac and celecoxib. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Modulation of expression of Programmed Death-1 by administration of probiotic Dahi in DMH-induced colorectal carcinogenesis in rats.

PubMed

Mohania, Dheeraj; Kansal, Vinod K; Kumar, Manoj; Nagpal, Ravinder; Yamashiro, Yuichiro; Marotta, Francesco

2013-09-01

Interaction of probiotic bacteria with the host immune system elicits beneficial immune modulating effects. Although, there are many published studies on interaction of probiotics with immune system focusing on activation of immune system by bacterial cell wall through the engagement of Toll-like receptor family; very few studies have focused on molecules involved in the T-cell activation, and not much work has been executed to study the correlation of probiotics and programmed death-1 in colorectal carcinogenesis in animal models. Hence, the present study was carried out to assess the effect of probiotic Dahi on expression of programmed death (PD-1) in colorectum of 1, 2-dimethylhydrazine treated Wistar rats. DMH was injected subcutaneously at the rate of 40 mg/kg body weight per animal twice a week for 2 weeks. A total of 168 male Wistar rats were randomly allocated to seven groups, each group having twenty-four animals. The rats were euthanized at the 8th, 16th and 32nd week of the experiment and examined for the expression of PD-1 in colorectal tissues by immunohistochemical staining. Expression of PD-1 was observed in colorectal tissues of normal and DMH-treated rats. Feeding rats with probiotic Dahi or the treatment with piroxicam decreased the expression of PD-1 in DMH-induced colorectal mucosa, and the combined treatment with probiotic Dahi and piroxicam was significantly more effective in reducing the expression of PD-1. PD-1 expressed independent of carcinogen administration in normal colonic mucosa and may play a role in modulation of immune response in DMH-induced colorectal carcinogenesis. The present study suggests that probiotic Dahi can be used as an effective chemopreventive agent in the management of colorectal cancer.

Circadian rhythms and food anticipatory behavior in Wfs1-deficient mice.

PubMed

Luuk, Hendrik; Fahrenkrug, Jan; Hannibal, Jens

2012-08-10

The dorsomedial hypothalamic nucleus (DMH) has been proposed as a candidate for the neural substrate of a food-entrainable oscillator. The existence of a food-entrainable oscillator in the mammalian nervous system was inferred previously from restricted feeding-induced behavioral rhythmicity in rodents with suprachiasmatic nucleus lesions. In the present study, we have characterized the circadian rhythmicity of behavior in Wfs1-deficient mice during ad libitum and restricted feeding. Based on the expression of Wfs1 protein in the DMH it was hypothesized that Wfs1-deficient mice will display reduced or otherwise altered food anticipatory activity. Wfs1 immunoreactivity in DMH was found almost exclusively in the compact part. Restricted feeding induced c-Fos immunoreactivity primarily in the ventral and lateral aspects of DMH and it was similar in both genotypes. Wfs1-deficiency resulted in significantly lower body weight and reduced wheel-running activity. Circadian rhythmicity of behavior was normal in Wfs1-deficient mice under ad libitum feeding apart from elongated free-running period in constant light. The amount of food anticipatory activity induced by restricted feeding was not significantly different between the genotypes. Present results indicate that the effects of Wfs1-deficiency on behavioral rhythmicity are subtle suggesting that Wfs1 is not a major player in the neural networks responsible for circadian rhythmicity of behavior. Copyright © 2012 Elsevier Inc. All rights reserved.

The effect of rosmarinic acid on 1,2-dimethylhydrazine induced colon carcinogenesis.

PubMed

Venkatachalam, Karthikkumar; Gunasekaran, Sivagami; Jesudoss, Victor Antony Santiago; Namasivayam, Nalini

2013-05-01

This study was carried out to investigate the chemopreventive potential of rosmarinic acid (RA) against 1,2-dimethylhydrazine (DMH) induced rat colon carcinogenesis by evaluating the effect of RA on tumour formation, antioxidant enzymes, cytochrome P450 content, p-nitrophenol hydroxylase and GST activities. Rats were divided into six groups and fed modified pellet diet for the entire experimental period. Group 1 served as control, group 2 received RA (10 mg/kgb.w.). Groups 3-6 were induced colon cancer by injecting DMH (20 mg/kgb.w.) subcutaneously once a week for the first four weeks (groups 3-6). In addition, RA was administered at the doses of 2.5, 5 and 10 mg/kgb.w. to groups 4-6 respectively. DMH treated rats showed large number of colonic tumours; decreased lipid peroxidation; decreased antioxidant status; elevated CYP450 content and PNPH activities; and decreased GST activity in the liver and colon. Supplementation with RA (5 mgkg/b.w.) to DMH treated rats significantly decreased the number of polyps (50%); reversed the markers of oxidative stress (21.0%); antioxidant status (38.55%); CYP450 content (29.41%); and PNPH activities (21.9%). RA at the dose of 5 mg/kgb.w. showed a most pronounced effect and could be used as a possible chemopreventive agent against colon cancer. Copyright © 2011 Elsevier GmbH. All rights reserved.

Neural Substrate of Cold-Seeking Behavior in Endotoxin Shock

PubMed Central

Almeida, Maria C; Steiner, Alexandre A; Branco, Luiz G S; Romanovsky, Andrej A

2006-01-01

Systemic inflammation is a leading cause of hospital death. Mild systemic inflammation is accompanied by warmth-seeking behavior (and fever), whereas severe inflammation is associated with cold-seeking behavior (and hypothermia). Both behaviors are adaptive. Which brain structures mediate which behavior is unknown. The involvement of hypothalamic structures, namely, the preoptic area (POA), paraventricular nucleus (PVH), or dorsomedial nucleus (DMH), in thermoregulatory behaviors associated with endotoxin (lipopolysaccharide [LPS])-induced systemic inflammation was studied in rats. The rats were allowed to select their thermal environment by freely moving in a thermogradient apparatus. A low intravenous dose of Escherichia coli LPS (10 µg/kg) caused warmth-seeking behavior, whereas a high, shock-inducing dose (5,000 µg/kg) caused cold-seeking behavior. Bilateral electrocoagulation of the PVH or DMH, but not of the POA, prevented this cold-seeking response. Lesioning the DMH with ibotenic acid, an excitotoxin that destroys neuronal bodies but spares fibers of passage, also prevented LPS-induced cold-seeking behavior; lesioning the PVH with ibotenate did not affect it. Lesion of no structure affected cold-seeking behavior induced by heat exposure or by pharmacological stimulation of the transient receptor potential (TRP) vanilloid-1 channel (“warmth receptor”). Nor did any lesion affect warmth-seeking behavior induced by a low dose of LPS, cold exposure, or pharmacological stimulation of the TRP melastatin-8 (“cold receptor”). We conclude that LPS-induced cold-seeking response is mediated by neuronal bodies located in the DMH and neural fibers passing through the PVH. These are the first two landmarks on the map of the circuitry of cold-seeking behavior associated with endotoxin shock. PMID:17183631

Dietary aloe vera gel powder and extract inhibit azoxymethane- induced colorectal aberrant crypt foci in mice fed a high- fat diet.

PubMed

Chihara, Takeshi; Shimpo, Kan; Kaneko, Takaaki; Beppu, Hidehiko; Higashiguchi, Takashi; Sonoda, Shigeru; Tanaka, Miyuki; Yamada, Muneo; Abe, Fumiaki

2015-01-01

Aloe vera gel exhibits protective effects against insulin resistance as well as lipid-lowering and anti-diabetic effects. The anti-diabetic compounds in this gel were identified as Aloe-sterols. Aloe vera gel extract (AVGE) containing Aloe-sterols has recently been produced using a new procedure. We previously reported that AVGE reduced large-sized intestinal polyps in Apc-deficient Min mice fed a high fat diet (HFD), suggesting that Aloe vera gel may protect against colorectal cancer. In the present study, we examined the effects of Aloe vera gel powder (AVGP) and AVGE on azoxymethane-induced colorectal preneoplastic aberrant crypt foci (ACF) in mice fed a HFD. Male C57BL/6J mice were given a normal diet (ND), HFD, HFD containing 0.5% carboxymethyl cellulose solution, which was used as a solvent for AVGE (HFDC), HFD containing 3% or 1% AVGP, and HFDC containing 0.0125% (H-) or 0.00375% (L-) AVGE. The number of ACF was significantly lower in mice given 3% AVGP and H-AVGE than in those given HFD or HFDC alone. Moreover, 3% AVGP, H-AVGE and L-AVGE significantly decreased the mean Ki-67 labeling index, assessed as a measure of cell proliferation in the colonic mucosa. In addition, hepatic phase II enzyme glutathione S-transferase mRNA levels were higher in the H-AVGE group than in the HFDC group. These results suggest that both AVGP and AVGE may have chemopreventive effects on colorectal carcinogenesis under the HFD condition. Furthermore, the concentration of Aloe-sterols was similar between 3% AVGP and H-AVGE, suggesting that Aloe-sterols were the main active ingredients in this experiment.

Colonic aberrant crypt formation accompanies an increase of opportunistic pathogenic bacteria in C57BL/6 mice fed a high-fat diet.

PubMed

Zeng, Huawei; Ishaq, Suzanne L; Liu, Zhenhua; Bukowski, Michael R

2018-04-01

The increasing worldwide incidence of colon cancer has been linked to obesity and consumption of a high-fat Western diet. To test the hypothesis that a high-fat diet (HFD) promotes colonic aberrant crypt (AC) formation in a manner associated with gut bacterial dysbiosis, we examined the susceptibility to azoxymethane (AOM)-induced colonic AC and microbiome composition in C57/BL6 mice fed a modified AIN93G diet (AIN, 16% fat, energy) or an HFD (45% fat, energy) for 14 weeks. Mice receiving the HFD exhibited increased plasma leptin, body weight, body fat composition and inflammatory cell infiltration in the ileum compared with those in the AIN group. Consistent with the gut inflammatory phenotype, we observed an increase in colonic AC, plasma interleukin-6, tumor necrosis factor-α, monocyte chemoattractant protein-1 and inducible nitric oxide synthase in the ileum of the HFD-AOM group compared with the AIN-AOM group. Although the HFD and AIN groups did not differ in bacterial species number, the HFD and AIN diets resulted in different bacterial community structures in the colon. The abundance of certain short-chain fatty acid (SCFA) producing bacteria (e.g., Barnesiella) and fecal SCFA (e.g., acetic acid) content were lower in the HFD-AOM group compared with the AIN and AIN-AOM groups. Furthermore, we identified a high abundance of Anaeroplasma bacteria, an opportunistic pathogen in the HFD-AOM group. Collectively, we demonstrate that an HFD promotes AC formation concurrent with an increase of opportunistic pathogenic bacteria in the colon of C57BL/6 mice. Published by Elsevier Inc.

Tetrahydrocurcumin is more effective than curcumin in preventing azoxymethane-induced colon carcinogenesis.

PubMed

Lai, Ching-Shu; Wu, Jia-Ching; Yu, Shih-Feng; Badmaev, Vladimir; Nagabhushanam, Kalyanam; Ho, Chi-Tang; Pan, Min-Hsiung

2011-12-01

Tetrahydrocurcumin (THC), a major metabolite of curcumin (CUR), has been demonstrated to be anti-cancerogenic and anti-angiogenic and prevents type II diabetes. In this present study, we investigated the chemopreventive effects and underlying molecular mechanisms of dietary administration of CUR and THC in azoxymethane (AOM)-induced colon carcinogenesis in mice. All mice were sacrificed at 6 and 23 wk, and colonic tissue was collected and examined. We found that dietary administration of both CUR and THC could reduce aberrant crypt foci and polyps formation, while THC showed a better inhibitory effect than CUR. At the molecular level, results from Western blot analysis and immunohistochemistry staining showed that dietary CUR and THC exhibited anti-inflammatory activity by decreasing the levels of inducible NOS and COX-2 through downregulation of ERK1/2 activation. In addition, both dietary CUR and THC significantly decreased AOM-induced Wnt-1 and β-catenin protein expression, as well as the phosphorylation of GSK-3β in colonic tissue. Moreover, dietary feeding with CUR and THC markedly reduced the protein level of connexin-43, an important molecule of gap junctions, indicating that both CUR and THC might interfer with the intercellular communication of crypt cells. Taken together, these results demonstrated for the first time the in vivo chemopreventive efficacy and molecular mechanisms of dietary THC against AOM-induced colonic tumorigenesis. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Food-grade TiO2 impairs intestinal and systemic immune homeostasis, initiates preneoplastic lesions and promotes aberrant crypt development in the rat colon.

PubMed

Bettini, Sarah; Boutet-Robinet, Elisa; Cartier, Christel; Coméra, Christine; Gaultier, Eric; Dupuy, Jacques; Naud, Nathalie; Taché, Sylviane; Grysan, Patrick; Reguer, Solenn; Thieriet, Nathalie; Réfrégiers, Matthieu; Thiaudière, Dominique; Cravedi, Jean-Pierre; Carrière, Marie; Audinot, Jean-Nicolas; Pierre, Fabrice H; Guzylack-Piriou, Laurence; Houdeau, Eric

2017-01-20

Food-grade titanium dioxide (TiO 2 ) containing a nanoscale particle fraction (TiO 2 -NPs) is approved as a white pigment (E171 in Europe) in common foodstuffs, including confectionary. There are growing concerns that daily oral TiO 2 -NP intake is associated with an increased risk of chronic intestinal inflammation and carcinogenesis. In rats orally exposed for one week to E171 at human relevant levels, titanium was detected in the immune cells of Peyer's patches (PP) as observed with the TiO 2 -NP model NM-105. Dendritic cell frequency increased in PP regardless of the TiO 2 treatment, while regulatory T cells involved in dampening inflammatory responses decreased with E171 only, an effect still observed after 100 days of treatment. In all TiO 2 -treated rats, stimulation of immune cells isolated from PP showed a decrease in Thelper (Th)-1 IFN-γ secretion, while splenic Th1/Th17 inflammatory responses sharply increased. E171 or NM-105 for one week did not initiate intestinal inflammation, while a 100-day E171 treatment promoted colon microinflammation and initiated preneoplastic lesions while also fostering the growth of aberrant crypt foci in a chemically induced carcinogenesis model. These data should be considered for risk assessments of the susceptibility to Th17-driven autoimmune diseases and to colorectal cancer in humans exposed to TiO 2 from dietary sources.

Food-grade TiO2 impairs intestinal and systemic immune homeostasis, initiates preneoplastic lesions and promotes aberrant crypt development in the rat colon

PubMed Central

Bettini, Sarah; Boutet-Robinet, Elisa; Cartier, Christel; Coméra, Christine; Gaultier, Eric; Dupuy, Jacques; Naud, Nathalie; Taché, Sylviane; Grysan, Patrick; Reguer, Solenn; Thieriet, Nathalie; Réfrégiers, Matthieu; Thiaudière, Dominique; Cravedi, Jean-Pierre; Carrière, Marie; Audinot, Jean-Nicolas; Pierre, Fabrice H.; Guzylack-Piriou, Laurence; Houdeau, Eric

2017-01-01

Food-grade titanium dioxide (TiO2) containing a nanoscale particle fraction (TiO2-NPs) is approved as a white pigment (E171 in Europe) in common foodstuffs, including confectionary. There are growing concerns that daily oral TiO2-NP intake is associated with an increased risk of chronic intestinal inflammation and carcinogenesis. In rats orally exposed for one week to E171 at human relevant levels, titanium was detected in the immune cells of Peyer’s patches (PP) as observed with the TiO2-NP model NM-105. Dendritic cell frequency increased in PP regardless of the TiO2 treatment, while regulatory T cells involved in dampening inflammatory responses decreased with E171 only, an effect still observed after 100 days of treatment. In all TiO2-treated rats, stimulation of immune cells isolated from PP showed a decrease in Thelper (Th)-1 IFN-γ secretion, while splenic Th1/Th17 inflammatory responses sharply increased. E171 or NM-105 for one week did not initiate intestinal inflammation, while a 100-day E171 treatment promoted colon microinflammation and initiated preneoplastic lesions while also fostering the growth of aberrant crypt foci in a chemically induced carcinogenesis model. These data should be considered for risk assessments of the susceptibility to Th17-driven autoimmune diseases and to colorectal cancer in humans exposed to TiO2 from dietary sources. PMID:28106049

Comparative DNA adduct formation and induction of colonic aberrant crypt foci in mice exposed to 2-amino-9H-pyrido[2,3-b]indole, 2-amino-3,4-dimethylimidazo[4,5-f]quinoline and azoxymethane

PubMed Central

Kim, Sangyub; Guo, Jingshu; O’Sullivan, M. Gerald; Gallaher, Daniel D.; Turesky, Robert J.

2015-01-01

Considerable evidence suggests that environmental factors, including diet and cigarette smoke, are involved in the pathogenesis of colon cancer. Carcinogenic nitroso compounds (NOC), such as N-nitrosodimethylamine (NDMA), are present in tobacco and processed red meat, and NOC have been implicated in colon cancer. Azoxymethane (AOM), commonly used for experimental colon carcinogenesis, is an isomer of NDMA, and it produces the same DNA adducts as does NDMA. Heterocyclic aromatic amines (HAAs) formed during the combustion of tobacco and high-temperature cooking of meats are also associated with an elevated risk of colon cancer. The most abundant carcinogenic HAA formed in tobacco smoke is 2-amino-9H-pyrido[2,3-b]indole (AαC), whereas 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ) is the most potent carcinogenic HAA formed during the cooking of meat and fish. However, the comparative tumor-initiating potential of AαC, MeIQ, and AOM is unknown. In this report, we evaluate the formation of DNA adducts as a measure of genotoxicity, and the induction of colonic aberrant crypt foci (ACF) and dysplastic ACF, as an early measure of carcinogenic potency of these compounds in the colon of male A/J mice. Both AαC and AOM induced a greater number of DNA adducts than MeIQ in the liver and colon. AOM induced a greater number of ACF and dysplastic ACF than either AαC or MeIQ. Conversely, based on adduct levels, MeIQ-DNA adducts were more potent than AαC- and AOM-DNA adducts at inducing ACF. Long-term feeding studies are required to relate levels of DNA adducts, induction of ACF, and colon cancer by these colon genotoxicants. PMID:26734915

The chemopreventive potential of Curcuma purpurascens rhizome in reducing azoxymethane-induced aberrant crypt foci in rats

PubMed Central

Rouhollahi, Elham; Moghadamtousi, Soheil Zorofchian; Al-Henhena, Nawal; Kunasegaran, Thubasni; Hasanpourghadi, Mohadeseh; Looi, Chung Yeng; Abd Malek, Sri Nurestri; Awang, Khalijah; Abdulla, Mahmood Ameen; Mohamed, Zahurin

2015-01-01

Curcuma purpurascens BI. rhizome, a member of the Zingiberaceae family, is a popular spice in Indonesia that is traditionally used in assorted remedies. Dichloromethane extract of C. purpurascens BI. rhizome (DECPR) has previously been shown to have an apoptosis-inducing effect on colon cancer cells. In the present study, we examined the potential of DECPR to prevent colon cancer development in rats treated with azoxymethane (AOM) (15 mg/kg) by determining the percentage inhibition in incidence of aberrant crypt foci (ACF). Starting from the day immediately after AOM treatment, three groups of rats were orally administered once a day for 2 months either 10% Tween 20 (5 mL/kg, cancer control), DECPR (250 mg/kg, low dose), or DECPR (500 mg/kg, high dose). Meanwhile, the control group was intraperitoneally injected with 5-fluorouracil (35 mg/kg) for 5 consecutive days. After euthanizing the rats, the number of ACF was enumerated in colon tissues. Bax, Bcl-2, and proliferating cell nuclear antigen (PCNA) protein expressions were examined using immunohistochemical and Western blot analyses. Antioxidant enzymatic activity was measured in colon tissue homogenates and associated with malondialdehyde level. The percentage inhibition of ACF was 56.04% and 68.68% in the low- and high-dose DECPR-treated groups, respectively. The ACF inhibition in the treatment control group was 74.17%. Results revealed that DECPR exposure at both doses significantly decreased AOM-induced ACF formation, which was accompanied by reduced expression of PCNA. Upregulation of Bax and downregulation of Bcl-2 suggested the involvement of apoptosis in the chemopreventive effect of DECPR. In addition, the oxidative stress resulting from AOM treatment was significantly attenuated after administration of DECPR, which was shown by the elevated antioxidant enzymatic activity and reduced malondialdehyde level. Taken together, the present data clearly indicate that DECPR significantly inhibits ACF formation in AOM-treated rats and may offer protection against colon cancer development. PMID:26251570

Doxycycline Promotes Carcinogenesis & Metastasis via Chronic Inflammatory Pathway: An In Vivo Approach

PubMed Central

Nanda, Neha; Dhawan, Devinder K.; Bhatia, Alka; Mahmood, Akhtar; Mahmood, Safrun

2016-01-01

Background Doxycycline (DOX) exhibits anti-inflammatory, anti-tumor, and pro-apoptotic activity and is being tested in clinical trials as a chemotherapeutic agent for several cancers, including colon cancer. Materials & Methods In the current study, the chemotherapeutic activity of doxycycline was tested in a rat model of colon carcinogenesis, induced by colon specific cancer promoter, 1,2, dimethylhydrazine (DMH) as well as study the effect of DOX-alone on a separate group of rats. Results Doxycycline administration in DMH-treated rats (DMH-DOX) unexpectedly increased tumor multiplicity, stimulated progression of colonic tumor growth from adenomas to carcinomas and revealed metastasis in small intestine as determined by macroscopic and histopathological analysis. DOX-alone treatment showed markedly enhanced chronic inflammation and reactive hyperplasia, which was dependent upon the dose of doxycycline administered. Moreover, immunohistochemical analysis revealed evidence of inflammation and anti-apoptotic action of DOX by deregulation of various biomarkers. Conclusion These results suggest that doxycycline caused chronic inflammation in colon, small intestine injury, enhanced the efficacy of DMH in tumor progression and provided a mechanistic link between doxycycline-induced chronic inflammation and tumorigenesis. Ongoing studies thus may need to focus on the molecular mechanisms of doxycycline action, which lead to its inflammatory and tumorigenic effects. PMID:26998758

HIV enteropathy: crypt stem and transit cell hyperproliferation induces villous atrophy in HIV/Microsporidia-infected jejunal mucosa.

PubMed

Batman, Philip A; Kotler, Donald P; Kapembwa, Moses S; Booth, Dawn; Potten, Christopher S; Orenstein, Jan M; Scally, Andrew J; Griffin, George E

2007-02-19

The study aim was to analyse the kinetics of stem and transit cells in the crypts of jejunal mucosa infected with HIV and Microsporidia. The size of villi, depth of crypts and proliferative activity of transit and stem cells in jejunal mucosa were measured using morphometric techniques. The surface area/volume ratio (S/V) of jejunal biopsies was estimated under light microscopy using a Weibel graticule. Crypt length was measured by counting enterocytes along the crypt side from the base to the villus junction, and the mean crypt length was calculated. The S/V and crypt lengths of the jejunal mucosa of 21 HIV and Microsporidia-infected test cases were compared with 14 control cases. The labelling index in relation to the crypt cell position of 10 of the test cases was analysed compared with 13 control cases. Differences were found in the S/V and crypt length, and there was a negative correlation between S/V and crypt length in test and control cases combined. Cell labelling indices fell into low and high proliferation groups. There were significant differences in labelling indices between low proliferation test cases and controls, between high proliferation test cases and controls, and between high and low proliferation test cases. Villous atrophy induced by HIV and Microsporidia is attributed to crypt cell hyperplasia and the encroachment of crypt cells onto villi. These infections induce crypt hypertrophy by stimulating cell mitosis predominantly in transit cells but also in stem cells. Increased stem cell proliferation occurs only in high proliferation cases.

Evidence for Time-of-Day Dependent Effect of Neurotoxic Dorsomedial Hypothalamic Lesions on Food Anticipatory Circadian Rhythms in Rats

PubMed Central

Landry, Glenn J.; Kent, Brianne A.; Patton, Danica F.; Jaholkowski, Mark; Marchant, Elliott G.; Mistlberger, Ralph E.

2011-01-01

The dorsomedial hypothalamus (DMH) is a site of circadian clock gene and immediate early gene expression inducible by daytime restricted feeding schedules that entrain food anticipatory circadian rhythms in rats and mice. The role of the DMH in the expression of anticipatory rhythms has been evaluated using different lesion methods. Partial lesions created with the neurotoxin ibotenic acid (IBO) have been reported to attenuate food anticipatory rhythms, while complete lesions made with radiofrequency current leave anticipatory rhythms largely intact. We tested a hypothesis that the DMH and fibers of passage spared by IBO lesions play a time-of-day dependent role in the expression of food anticipatory rhythms. Rats received intra-DMH microinjections of IBO and activity and body temperature (T b) rhythms were recorded by telemetry during ad-lib food access, total food deprivation and scheduled feeding, with food provided for 4-h/day for 20 days in the middle of the light period and then for 20 days late in the dark period. During ad-lib food access, rats with DMH lesions exhibited a lower amplitude and mean level of light-dark entrained activity and T b rhythms. During the daytime feeding schedule, all rats exhibited food anticipatory activity and T b rhythms that persisted during 2 days without food in constant dark. In some rats with partial or total DMH ablation, the magnitude of the anticipatory rhythm was weak relative to most intact rats. When mealtime was shifted to the late night, the magnitude of the food anticipatory activity rhythms in these cases was restored to levels characteristic of intact rats. These results confirm that rats can anticipate scheduled daytime or nighttime meals without the DMH. Improved anticipation at night suggests a modulatory role for the DMH in the expression of food anticipatory activity rhythms during the daily light period, when nocturnal rodents normally sleep. PMID:21912674

Optical coherence tomography imaging of colonic crypts in a mouse model of colorectal cancer

NASA Astrophysics Data System (ADS)

Welge, Weston A.; Barton, Jennifer K.

2016-03-01

Aberrant crypt foci (ACF) are abnormal epithelial lesions that precede development of colonic polyps. As the earliest morphological change in the development of colorectal cancer, ACF is a highly studied phenomenon. The most common method of imaging ACF is chromoendoscopy using methylene blue as a contrast agent. Narrow- band imaging is a contrast-agent-free modality for imaging the colonic crypts. Optical coherence tomography (OCT) is an attractive alternative to chromoendoscopy and narrow-band imaging because it can resolve the crypt structure at sufficiently high sampling while simultaneously providing depth-resolved data. We imaged in vivo the distal 15 mm of colon in the azoxymethane (AOM) mouse model of colorectal cancer using a commercial swept-source OCT system and a miniature endoscope designed and built in-house. We present en face images of the colonic crypts and demonstrate that different patterns in healthy and adenoma tissue can be seen. These patterns correspond to those reported in the literature. We have previously demonstrated early detection of colon adenoma using OCT by detecting minute thickening of the mucosa. By combining mucosal thickness measurement with imaging of the crypt structure, OCT can be used to correlate ACF and adenoma development in space and time. These results suggest that OCT may be a superior imaging modality for studying the connection between ACF and colorectal cancer.

Aberrant epithelial GREM1 expression initiates colonic tumorigenesis from cells outside the stem cell niche.

PubMed

Davis, Hayley; Irshad, Shazia; Bansal, Mukesh; Rafferty, Hannah; Boitsova, Tatjana; Bardella, Chiara; Jaeger, Emma; Lewis, Annabelle; Freeman-Mills, Luke; Giner, Francesc Castro; Rodenas-Cuadrado, Pedro; Mallappa, Sreelakshmi; Clark, Susan; Thomas, Huw; Jeffery, Rosemary; Poulsom, Richard; Rodriguez-Justo, Manuel; Novelli, Marco; Chetty, Runjan; Silver, Andrew; Sansom, Owen James; Greten, Florian R; Wang, Lai Mun; East, James Edward; Tomlinson, Ian; Leedham, Simon John

2015-01-01

Hereditary mixed polyposis syndrome (HMPS) is characterized by the development of mixed-morphology colorectal tumors and is caused by a 40-kb genetic duplication that results in aberrant epithelial expression of the gene encoding mesenchymal bone morphogenetic protein antagonist, GREM1. Here we use HMPS tissue and a mouse model of the disease to show that epithelial GREM1 disrupts homeostatic intestinal morphogen gradients, altering cell fate that is normally determined by position along the vertical epithelial axis. This promotes the persistence and/or reacquisition of stem cell properties in Lgr5-negative progenitor cells that have exited the stem cell niche. These cells form ectopic crypts, proliferate, accumulate somatic mutations and can initiate intestinal neoplasia, indicating that the crypt base stem cell is not the sole cell of origin of colorectal cancer. Furthermore, we show that epithelial expression of GREM1 also occurs in traditional serrated adenomas, sporadic premalignant lesions with a hitherto unknown pathogenesis, and these lesions can be considered the sporadic equivalents of HMPS polyps.

The Chemopotential Effect of Annona muricata Leaves against Azoxymethane-Induced Colonic Aberrant Crypt Foci in Rats and the Apoptotic Effect of Acetogenin Annomuricin E in HT-29 Cells: A Bioassay-Guided Approach

PubMed Central

Zorofchian Moghadamtousi, Soheil; Rouhollahi, Elham; Karimian, Hamed; Fadaeinasab, Mehran; Firoozinia, Mohammad; Ameen Abdulla, Mahmood; Abdul Kadir, Habsah

2015-01-01

Annona muricata has been used in folk medicine for the treatment of cancer and tumors. This study evaluated the chemopreventive properties of an ethyl acetate extract of A. muricata leaves (EEAML) on azoxymethane-induced colonic aberrant crypt foci (ACF) in rats. Moreover, the cytotoxic compound of EEAML (Annomuricin E) was isolated, and its apoptosis-inducing effect was investigated against HT-29 colon cancer cell line using a bioassay-guided approach. This experiment was performed on five groups of rats: negative control, cancer control, EEAML (250 mg/kg), EEAML (500 mg/kg) and positive control (5-fluorouracil). Methylene blue staining of colorectal specimens showed that application of EEAML at both doses significantly reduced the colonic ACF formation compared with the cancer control group. Immunohistochemistry analysis showed the down-regulation of PCNA and Bcl-2 proteins and the up-regulation of Bax protein after administration of EEAML compared with the cancer control group. In addition, an increase in the levels of enzymatic antioxidants and a decrease in the malondialdehyde level of the colon tissue homogenates were observed, suggesting the suppression of lipid peroxidation. Annomuricin E inhibited the growth of HT-29 cells with an IC50 value of 1.62 ± 0.24 μg/ml after 48 h. The cytotoxic effect of annomuricin E was further substantiated by G1 cell cycle arrest and early apoptosis induction in HT-29 cells. Annomuricin E triggered mitochondria-initiated events, including the dissipation of the mitochondrial membrane potential and the leakage of cytochrome c from the mitochondria. Prior to these events, annomuricin E activated caspase 3/7 and caspase 9. Upstream, annomuricin E induced a time-dependent upregulation of Bax and downregulation of Bcl-2 at the mRNA and protein levels. In conclusion, these findings substantiate the usage of A. muricata leaves in ethnomedicine against cancer and highlight annomuricin E as one of the contributing compounds in the anticancer activity of A. muricata leaves. PMID:25860620

Radiation-induced hyperproliferation of intestinal crypts results in elevated genome instability with inactive p53-related genomic surveillance.

PubMed

Zhou, Xin; Ma, Xiaofei; Wang, Zhenhua; Sun, Chao; Wang, Yupei; He, Yang; Zhang, Hong

2015-12-15

Radiation-induced hyperproliferation of intestinal crypts is well documented, but its potential tumorigenic effects remain elusive. Here we aim to determine the genomic surveillance process during crypt hyperproliferation, and its consequential outcome after ionizing radiation. Crypt regeneration in the intestine was induced by a single dose of 12Gy abdominal irradiation. γ-H2AX, 53BP1 and DNA-PKcs were used as DNA repair surrogates to investigate the inherent ability of intestinal crypt cells to recognize and repair double-strand breaks. Ki67 staining and the 5-bromo-2'-deoxyuridine incorporation assay were used to study patterns of cell proliferation in regenerating crypts. Staining for ATM, p53, Chk1 and Chk2 was performed to study checkpoint activation and release. Apoptosis was evaluated through H&E staining and terminal deoxynucleotidyl transferase (dUTP) nick-end labeling. The ATM-p53 pathway was immediately activated after irradiation. A second wave of DSBs in crypt cells was observed in regenerating crypts, accompanied with significantly increased chromosomal bridges. The p53-related genomic surveillance pathway was not active during the regeneration phase despite DSBs and chromosomal bridges in the cells of regenerating crypts. Non-homologous end joining (NHEJ) DSBs repair was involved in the DSBs repair process, as indicated by p-DNA-PKcs staining. Intestinal crypt cells retained hyperproliferation with inactive p53-related genomic surveillance system. NHEJ was involved in the resultant genomic instability during hyperproliferation. Copyright © 2015 Elsevier Inc. All rights reserved.

Interactive suppression of aberrant crypt foci induced by azoxymethane in rat colon by phytic acid and green tea.

PubMed

Challa, A; Rao, D R; Reddy, B S

1997-10-01

Several epidemiological studies point to a strong correlation between nutrient composition of the diet and cancer of the colon. Phytic acid, present in grains, has been credited with reducing the risk of cancer of the colon. A number of reports are available indicating the benefits of green tea consumption in reducing the risk of stomach, lung and skin cancer, but little data are available on the effect of green tea in reducing the risk of colon cancer. Also, there are no studies on the combined effect of these compounds on colon tumorigenesis. Thus the primary objective of this investigation was to elucidate the combined effects of green tea and phytic acid on colonic preneoplastic lesions and the Phase II enzyme glutathione S-transferase. Fisher 344 male weanling rats were divided into nine groups of 15 rats each and fed the experimental diet for 13 weeks. Rats received two s.c. injections of azoxymethane in saline at 16 mg/kg body wt at 7 and 8 weeks of age. Rats received three levels (0, 1 and 2%) of phytic acid with three levels (0, 1 and 2%) of green tea within each phytic acid level in a 3 x 3 factorial experiment. Results indicate that while green tea had a marginal effect (P < 0.14), phytic acid significantly reduced the incidence of aberrant crypt foci (P < 0.008). The interaction between green tea and phytic acid was significant (P < 0.029 for distal and < 0.0168 for entire colon) and positive, pointing to a synergistic effect of green tea and phytic acid.

Chemoprevention of Colonic Aberrant Crypt Foci by Novel Schiff Based Dichlorido(4-Methoxy-2-{[2-(Piperazin-4-Ium-1-Yl)Ethyl]Iminomethyl}Phenolate)Cd Complex in Azoxymethane-Induced Colorectal Cancer in Rats

PubMed Central

Hajrezaie, Maryam; Shams, Keivan; Moghadamtousi, Soheil Zorofchian; Karimian, Hamed; Hassandarvish, Pouya; Emtyazjoo, Mozhgan; Zahedifard, Maryam; Majid, Nazia Abdul; Ali, Hapipah Mohd; Abdulla, Mahmood Ameen

2015-01-01

Schiff-based complexes as a source of cancer chemotherapeutic compounds have been subjected to the variety of anticancer studies. The in-vitro analysis confirmed the CdCl2(C14H21N3O2) complex possess cytotoxicity and apoptosis induction properties in colon cancer cells, so lead to investigate the inhibitory efficiency of the compound on colonic aberrant crypt foci (ACF). Five groups of adult male rats were used in this study: Vehicle, cancer control, positive control groups and the groups treated with 25 and 50 mg/kg of complex for 10 weeks. The rats in vehicle group were injected subcutaneously with 15 mg/kg of sterile normal saline once a week for 2 weeks and orally administered with 5% Tween-20 (5 ml/kg) for 10 weeks, other groups were injected subcutaneously with 15 mg/kg azoxymethane once a week for 2 weeks. The rats in positive groups were injected intra-peritoneally with 35 mg/kg 5-Flourouracil four times in a month. Administration of the complex suppressed total colonic ACF formation up to 73.4% (P < 0.05). The results also showed that treatment with the complex significantly reduced the level of malondialdehyde while increasing superoxide dismutase and catalase activities. Furthermore, the down-regulation of PCNA and Bcl2 and the up-regulation of Bax was confirmed by immunohistochemical staining. PMID:26201720

Beneficial Biological Effects of Miso with Reference to Radiation Injury, Cancer and Hypertension

PubMed Central

Watanabe, Hiromitsu

2013-01-01

This review describes effects of miso with reference to prevention of radiation injury, cancer and hypertension with a twin focus on epidemiological and experimental evidence. Miso with a longer fermentation time increased crypt survival against radiation injury in mice. When evaluating different types of miso provided by different areas in Japan, miso fermented for a longer period increased the number of surviving crypts, and 180 days of fermentation was the most significant. Dietary administration of 180-day fermented miso inhibits the development of azoxymethane (AOM)-induced aberrant crypt foci (ACF) and rat colon cancers in F344 rats. Miso was also effective in suppression of lung tumors, breast tumors in rats and liver tumors in mice. The incidence of gastric tumors of groups of rats given NaCl was higher than those of the groups given miso fermented for longer periods. Moreover, the systolic blood pressure of the Dahl male rat on 2.3% NaCl was significantly increased but that of the SD rat was not. However, the blood pressures of the rats on a diet of miso or commercial control diet (MF) did not increase. Even though miso contains 2.3% NaCl, their blood pressures were as stable as those of rats fed commercial diet containing 0.3% salt. So we considered that sodium in miso might behave differently compared with NaCl alone. These biological effects might be caused by longer fermentation periods. PMID:23914051

Immunocytochemistry and Image Analysis of Beta-Catenin Redistribution in Normal Human Colon Cell Cultures Treated with Disinfection By-Products.

EPA Science Inventory

Epidemiological studies have shown an association between the consumption of chlorinated drinking water and increased risk for colon cancer. In vivo studies proved that rodents exposed to chlorination disinfection byproducts (DBPs) developed aberrant crypt foci (ACF) in t...

Direct pyrogenic input from prostaglandin EP3 receptor-expressing preoptic neurons to the dorsomedial hypothalamus

PubMed Central

Nakamura, Yoshiko; Nakamura, Kazuhiro; Matsumura, Kiyoshi; Kobayashi, Shigeo; Kaneko, Takeshi; Morrison, Shaun F.

2008-01-01

Fever is induced by the neuronal mechanism in the brain. Prostaglandin (PG) E2 acts as a pyrogenic mediator in the preoptic area (POA) probably through the EP3 subtype of PGE receptor expressed on GABAergic neurons, and this PGE2 action triggers neuronal pathways for sympathetic thermogenesis in peripheral effector organs including brown adipose tissue (BAT). To explore pyrogenic efferent pathways from the POA, we here determined projection targets of EP3 receptor-expressing POA neurons with a special focus on rat hypothalamic regions including the dorsomedial hypothalamic nucleus (DMH), which is known as a center for autonomic responses to stress. Among injections of cholera toxin b-subunit (CTb), a retrograde tracer, into hypothalamic regions at the rostrocaudal level of the DMH, injections into the DMH, lateral hypothalamic area (LH), and dorsal hypothalamic area (DH) resulted in EP3 receptor immunolabeling in substantial populations of CTb-labeled neurons in the POA. Bilateral microinjections of muscimol, a GABAA receptor agonist, into the DMH and a ventral region of the DH, but not those into the LH, inhibited thermogenic (BAT sympathetic nerve activity, BAT temperature, core body temperature, and expired CO2) and cardiovascular (arterial pressure and heart rate) responses to an intra-POA PGE2 microinjection. Further immunohistochemical observations revealed close association of POA-derived GABAergic axon swellings with DMH neurons projecting to the medullary raphe regions where sympathetic premotor neurons for febrile and thermoregulatory responses are localized. These results suggest that a direct projection of EP3 receptor-expressing POA neurons to the DMH/DH region mediates febrile responses via a GABAergic mechanism. PMID:16367780

Evidence that (-)-7-hydroxy-4'-dimethylheptyl-cannabidiol activates a non-CB(1), non-CB(2), non-TRPV1 target in the mouse vas deferens.

PubMed

Pertwee, Roger G; Thomas, Adèle; Stevenson, Lesley A; Maor, Yehoshua; Mechoulam, Raphael

2005-06-01

Previous experiments showed that R-(+)-WIN55212-induced inhibition of electrically-evoked contractions of mouse vasa deferentia could be antagonized by cannabidiol in a manner that appeared to be competitive but not to involve direct competition for established cannabinoid receptors. We have now discovered that (-)-7-hydroxy-4'-dimethylheptyl-cannabidiol (7-OH-DMH-CBD) inhibits electrically-evoked contractions of the vas deferens (EC(50)=13.3 nM). This it appeared to do by acting on prejunctional neurones as 100 nM 7-OH-DMH-CBD did not attenuate contractile responses to phenylephrine or beta,gamma-methylene-ATP. Although 7-OH-DMH-CBD was antagonized by SR141716A, it was less susceptible to antagonism by this CB(1) receptor antagonist than R-(+)-WIN55212. 7-OH-DMH-CBD was also antagonized by cannabidiol (1 microM; apparent K(B)=222.2 nM) but not by the CB(2) receptor antagonist, SR144528 (32 nM), or by naloxone (300 nM), ruthenium red (1 microM) or capsazepine (10 microM). Yohimbine (100 nM) enhanced the ability of 7-OH-DMH-CBD to inhibit electrically-evoked contractions. R-(+)-WIN55212 was also potentiated by 100 nM yohimbine, possibly reflecting ongoing sequestration of G(i/o) proteins from CB(1) receptors by alpha(2)-adrenoceptors. Our results suggest that 7-OH-DMH-CBD may activate a neuronal target in the vas deferens that is not a CB(1), CB(2), TRPV1, opioid or alpha(2)-adrenergic receptor but do not exclude the possibility that it also activates CB(1) receptors.

High fat diet induced-obesity facilitates anxiety-like behaviors due to GABAergic impairment within the dorsomedial hypothalamus in rats.

PubMed

de Noronha, Sylvana Rendeiro; Campos, Glenda Viggiano; Abreu, Aline Rezende; de Souza, Aline Arlindo; Chianca, Deoclécio A; de Menezes, Rodrigo C

2017-01-01

Overweight and obesity are conditions associated with an overall range of clinical health consequences, and they could be involved with the development of neuropsychiatric diseases, such as generalized anxiety disorder (GAD) and panic disorder (PD). A crucial brain nuclei involved on the physiological functions and behavioral responses, especially fear, anxiety and panic, is the dorsomedial hypothalamus (DMH). However, the mechanisms underlying the process whereby the DMH is involved in behavioral changes in obese rats still remains unclear. The current study further investigates the relation between obesity and generalized anxiety, by investigating the GABA A sensitivity to pharmacological manipulation within the DMH in obese rats during anxiety conditions. Male Wistar rats were divided in two experimental groups: the first was fed a control diet (CD; 11% w/w) and second was fed a high fat diet (HFD; 45% w/w). Animals were randomly treated with muscimol, a GABA A agonist and bicuculline methiodide (BMI), a GABA A antagonist. Inhibitory avoidance and escape behaviors were investigated using the Elevated T-Maze (ETM) apparatus. Our results revealed that the obesity facilitated inhibitory avoidance acquisition, suggesting a positive relation between obesity and the development of an anxiety-like state. The injection of muscimol (an anxiolytic drug), within the DMH, increased the inhibitory avoidance latency in obese animals (featuring an anxiogenic state). Besides, muscimol prolonged the escape latency and controlling the possible panic-like behavior in these animals. Injection of BMI into the DMH was ineffective to produce an anxiety-like effect in obese animals opposing the results observed in lean animals. These findings support the hypotheses that obese animals are susceptible to develop anxiety-like behaviors, probably through changes in the GABAergic neurotransmission within the DMH. Copyright © 2016 Elsevier B.V. All rights reserved.

Meat and cancer: haemoglobin and haemin in a low-calcium diet promote colorectal carcinogenesis at the aberrant crypt stage in rats

PubMed Central

Pierre, Fabrice; Taché, Sylviane; Petit, Claude R; Van Der Meer, Roelof; Corpet, Denis E

2003-01-01

High intake of red meat, but not of white meat, is associated with an increased risk of colon cancer. However, red meat does not promote cancer in rodents. Haemin, added to low-calcium diets, increases colonic proliferation, and haemoglobin, added to high-fat diets, increases the colon tumour incidence in rats, an effect possibly due to peroxyl radicals. We thus speculated that haem might be the promoting agent in meat, and that prevention strategies could use calcium and antioxidants. These hypotheses were tested in rats at the aberrant crypt foci (ACF) stage at 100 days. F344 rats (n=124) were given an injection of azoxymethane and were then randomised to 11 groups fed with low-calcium (20μmol/g) AIN76-based diets, containing 5% safflower oil. Haemin (0.25, 0.5 and 1.5μmol/g) or haemoglobin (1.5 and 3 μmol haem/g) was added to five experimental diets, compared to a control diet without haem. Three other high-haemin diets (1.5μmol/g) were supplemented with calcium (250μmol/g), antioxidant butylated hydroxyanisole and rutin (0.05% each), and olive oil, which replaced safflower oil. Faecal water was assayed for lipid peroxidation by thiobarbituric acid reactive substances (TBARs) test, and for cytolytic activity. Haemin strikingly increased the ACF size, dose-dependently, from 2.6 to 11.4 crypts/ACF (all p<0.001). The high-haemin diet also increased the number of ACF per colon (p<0.001). Promotion was associated with increased faecal water TBARs and cytotoxicity. Calcium, olive oil, and antioxidants each inhibited the haemin-induced ACF promotion, and normalised the faecal TBARs and cytotoxicity. The haemoglobin diets increased the number of ACF and faecal TBARs, but not the ACF size or the faecal cytotoxicity. In conclusion, dietary haemin is the most potent known ACF promoter. Haemoglobin is also a potent promoter of colorectal carcinogenesis. The results suggest that myoglobin in red meat could promote colon cancer. Diets high in calcium, or in oxidation-resistant fats, may prevent the possible cancer-promoting effect of red meat. PMID:12896910

Effect of Dietary-Resistant Starch on Inhibition of Colonic Preneoplasia and Wnt Signaling in Azoxymethane-Induced Rodent Models.

PubMed

Nelson, Bridget; Cray, Nicole; Ai, Yongfeng; Fang, Yinan; Liu, Peng; Whitley, Elizabeth M; Birt, Diane

2016-01-01

Dietary fiber has been reported to prevent preneoplastic colon lesions. The aim of this study was to determine the effect of resistant starches, novel dietary fibers, on the development of colonic preneoplasia and Wnt signaling in azoxymethane (AOM)-treated rats and mice fed resistant starches at 55% of the diet after AOM treatment. Another objective was to determine the effect of resistant starches on the development of preneoplasia in rats treated with antibiotics (Ab), administered between AOM treatment and resistant starch feeding. Diets containing resistant starches, high-amylose (HA7), high-amylose-octenyl succinic anhydride (OS-HA7), or high-amylose-stearic acid (SA-HA7) were compared with control cornstarch (CS). The resistant starch content of the diets did not alter the yield of colonic lesions but animals treated with AOM and fed the diet with the highest resistant starch content, SA-HA7 developed the highest average aberrant crypt foci (ACF) per animal. Mice fed the OS-HA7 diet had decreased expression of some upstream Wnt genes in the colonic crypts. This study suggests that further research is needed to determine if resistant starch impacts colon carcinogenesis in rodents.

Comet assay evaluation of six chemicals of known genotoxic potential in rats.

PubMed

Hobbs, Cheryl A; Recio, Leslie; Streicker, Michael; Boyle, Molly H; Tanaka, Jin; Shiga, Atsushi; Witt, Kristine L

2015-07-01

As a part of an international validation of the in vivo rat alkaline comet assay (comet assay) initiated by the Japanese Center for the Validation of Alternative Methods (JaCVAM) we examined six chemicals for potential to induce DNA damage: 2-acetylaminofluorene (2-AAF), N-nitrosodimethylamine (DMN), o-anisidine, 1,2-dimethylhydrazine dihydrochloride (1,2-DMH), sodium chloride, and sodium arsenite. DNA damage was evaluated in the liver and stomach of 7- to 9-week-old male Sprague Dawley rats. Of the five genotoxic carcinogens tested in our laboratory, DMN and 1,2-DMH were positive in the liver and negative in the stomach, 2-AAF and o-anisidine produced an equivocal result in liver and negative results in stomach, and sodium arsenite was negative in both liver and stomach. 1,2-DMH and DMN induced dose-related increases in hedgehogs in the same tissue (liver) that exhibited increased DNA migration. However, no cytotoxicity was indicated by the neutral diffusion assay (assessment of highly fragmented DNA) or histopathology in response to treatment with any of the tested chemicals. Therefore, the increased DNA damage resulting from exposure to DMN and 1,2-DMH was considered to represent a genotoxic response. Sodium chloride, a non-genotoxic non-carcinogen, was negative in both tissues as would be predicted. Although only two (1,2-DMH and DMN) out of five genotoxic carcinogens produced clearly positive results in the comet assay, the results obtained for o-anisidine and sodium arsenite in liver and stomach cells are consistent with the known mode of genotoxicity and tissue specificity exhibited by these carcinogens. In contrast, given the known genotoxic mode-of-action and target organ carcinogenicity of 2-AAF, it is unclear why this chemical failed to convincingly increase DNA migration in the liver. Thus, the results of the comet assay validation studies conducted in our laboratory were considered appropriate for five out of the six test chemicals. Copyright © 2015 Elsevier B.V. All rights reserved.

Comet assay evaluation of six chemicals of known genotoxic potential in rats

PubMed Central

Hobbs, Cheryl A.; Recio, Leslie; Streicker, Michael; Boyle, Molly H.; Tanaka, Jin; Shiga, Atsushi; Witt, Kristine L.

2015-01-01

As a part of an International validation of the in vivo rat alkaline comet assay (comet assay) initiated by the Japanese Center for the Validation of Alternative Methods (JaCVAM) we examined six chemicals for potential to induce DNA damage: 2-acetylaminofluorene (2-AAF), N-nitrosodimethylamine (DMN), o-anisidine, 1,2-dimethylhydrazine dihydrochloride (1,2-DMH), sodium chloride, and sodium arsenite. DNA damage was evaluated in the liver and stomach of 7- to 9-week-old male Sprague Dawley rats. Of the five genotoxic carcinogens tested in our laboratory, DMN and 1,2-DMH were positive in the liver and negative in the stomach, 2-AAF and o-anisidine produced an equivocal result in liver and negative results in stomach, and sodium arsenite was negative in both liver and stomach. 1,2-DMH and DMN induced dose-related increases in hedgehogs in the same tissue (liver) that exhibited increased DNA migration. However, no cytotoxicity was indicated by the neutral diffusion assay (assessment of highly fragmented DNA) or histopathology in response to treatment with any of the tested chemicals. Therefore, the increased DNA damage resulting from exposure to DMN and 1,2-DMH was considered to represent a genotoxic response. Sodium chloride, a non-genotoxic non-carcinogen, was negative in both tissues as would be predicted. Although only two (1,2-DMH and DMN) out of five genotoxic carcinogens produced clearly positive results in the comet assay, the results obtained for o-anisidine and sodium arsenite in liver and stomach cells are consistent with the known mode of genotoxicity and tissue specificity exhibited by these carcinogens. In contrast, given the known genotoxic mode-of-action and target organ carcinogenicity of 2-AAF, it is unclear why this chemical failed to convincingly increase DNA migration in the liver. Thus, the results of the comet assay validation studies conducted in our laboratory were considered appropriate for five out of the six test chemicals. PMID:26212309

Spontaneous Aberrant Crypt Foci in Apc1638N Mice with a Mutant Apc Allele

PubMed Central

Pretlow, Theresa P.; Edelmann, Winfried; Kucherlapati, Raju; Pretlow, Thomas G.; Augenlicht, Leonard H.

2003-01-01

The Apc1638N/+ mouse has a chain-terminating mutation in one allele of the adenomatous polyposis coli (Apc) gene that is similar to most mutations observed in the human familial adenomatous polyposis syndrome. Aberrant crypt foci (ACF), the earliest identified neoplastic lesions in the colon, are morphologically abnormal structures that are identifiedmicroscopically in the grossly normal colonic mucosas of rodents treated with colon carcinogens and of human patients. The colons and cecums of 62 Apc1638N/+ mice were evaluated for the spontaneous occurrence of ACF and tumors. Both male and female mice were killed at different times between 5 and 28 weeks of age. Wild-type littermates, ie, Apc+/+ mice, at 22 to 26 weeks of age served as controls. ACF were identified in 97% of the Apc1638N/+ mice starting at 5 weeks of age and not in any wild-type littermates. Although the number of ACF increased with age (P < 0.0001), the average number of crypts per focus of the ACF did not increase significantly. In addition, wild-type Apc protein was detected by immunohistochemistry in all 22 ACF evaluated. Together these data suggest that heterozygous loss of Apc may be sufficient to initiate ACF in these mice and that these mice may be suitable models to study the interaction of environmental factors with an inherited mutation of the Apc gene that is associated with colon cancer. PMID:14578176

Endocannabinoid signaling in hypothalamic circuits regulates arousal from general anesthesia in mice

PubMed Central

Zhong, Haixing; Tong, Li; Gu, Ning; Gao, Fang; Lu, Yacheng; Liu, Jingjing; Li, Xin; Bergeron, Richard; Pomeranz, Lisa E.; Wang, Feng; Luo, Chun-Xia; Ren, Yan; Wu, Sheng-Xi; Xie, Zhongcong; Xu, Lin; Li, Jinlian; Dong, Hailong; Xiong, Lize

2017-01-01

Consciousness can be defined by two major attributes: awareness of environment and self, and arousal, which reflects the level of awareness. The return of arousal after general anesthesia presents an experimental tool for probing the neural mechanisms that control consciousness. Here we have identified that systemic or intracerebral injection of the cannabinoid CB1 receptor (CB1R) antagonist AM281 into the dorsomedial nucleus of the hypothalamus (DMH) — but not the adjacent perifornical area (Pef) or the ventrolateral preoptic nucleus of the hypothalamus (VLPO) — accelerates arousal in mice recovering from general anesthesia. Anesthetics selectively activated endocannabinoid (eCB) signaling at DMH glutamatergic but not GABAergic synapses, leading to suppression of both glutamatergic DMH-Pef and GABAergic DMH-VLPO projections. Deletion of CB1R from widespread cerebral cortical or prefrontal cortical (PFC) glutamatergic neurons, including those innervating the DMH, mimicked the arousal-accelerating effects of AM281. In contrast, CB1R deletion from brain GABAergic neurons or hypothalamic glutamatergic neurons did not affect recovery time from anesthesia. Inactivation of PFC-DMH, DMH-VLPO, or DMH-Pef projections blocked AM281-accelerated arousal, whereas activation of these projections mimicked the effects of AM281. We propose that decreased eCB signaling at glutamatergic terminals of the PFC-DMH projection accelerates arousal from general anesthesia through enhancement of the excitatory DMH-Pef projection, the inhibitory DMH-VLPO projection, or both. PMID:28463228

THE INDUCTION OF ABERRANT CRYPT FOCI (ACF) IN THE COLONS OF RATS BY TRIHALOMETHANES ADMINISTERED IN THE DRINKING WATER

EPA Science Inventory

Bromodichloromethane (BDCM) and bromoform (TBM) had been demonstrated to be colon carcinogens in male and female F344/N rats following administration by corn oil gavage. Our chronic bioassay of BDCM administered in the drinking water failed to demonstrate an enhanced colon cance...

HIV enteropathy: HAART reduces HIV-induced stem cell hyperproliferation and crypt hypertrophy to normal in jejunal mucosa.

PubMed

Batman, Philip A; Kapembwa, Moses S; Belmonte, Liliana; Tudor, Gregory; Kotler, Donald P; Potten, Christopher S; Booth, Catherine; Cahn, Pedro; Griffin, George E

2014-01-01

To analyse the structural and kinetic response of small intestinal crypt epithelial cells including stem cells to highly active antiretroviral therapy (HAART). Crypt size and proliferative activity of transit and stem cells in jejunal mucosa were quantified using morphometric techniques. Crypt length was measured by counting the number of enterocytes along one side of a number of crypts in each biopsy specimen and the mean crypt length was calculated. Proliferating crypt cells were identified with MIB-1 monoclonal antibody, and the percentage of crypt cells in proliferation was calculated at each cell position along the length of the crypt (proliferation index). Data were obtained from 9 HIV-positive test patients co-infected with microsporidia, 34 HIV-positive patients receiving HAART and 13 control cases. Crypt length was significantly greater in test patients than in controls, but crypt length in patients receiving HAART was normal. The proliferation index was greater in test subjects than in controls in stem and transit cell compartments, and was decreased in patients treated with HAART only in the stem cell region of the crypt. Villous atrophy in HIV enteropathy is attributed to crypt hypertrophy and encroachment of crypt cells onto villi. HAART restores normal crypt structure by inhibition of HIV-driven stem cell hyperproliferation at the crypt bases.

Intestinal bacteria are necessary for doxorubicin-induced intestinal damage but not for doxorubicin-induced apoptosis.

PubMed

Rigby, Rachael J; Carr, Jacquelyn; Orgel, Kelly; King, Stephanie L; Lund, P Kay; Dekaney, Christopher M

2016-09-02

Doxorubicin (DOXO) induces significant, but transient, increases in apoptosis in the stem cell zone of the jejunum, followed by mucosal damage involving a decrease in crypt proliferation, crypt number, and villus height. The gastrointestinal tract is home to a vast population of commensal bacteria and numerous studies have demonstrated a symbiotic relationship between intestinal bacteria and intestinal epithelial cells (IEC) in maintaining homeostatic functions of the intestine. However, whether enteric bacteria play a role in DOXO-induced damage is not well understood. We hypothesized that enteric bacteria are necessary for induction of apoptosis and damage associated with DOXO treatment. Conventionally raised (CONV) and germ free (GF) mice were given a single injection of DOXO, and intestinal tissue was collected at 6, 72, and 120 h after treatment and from no treatment (0 h) controls. Histology and morphometric analyses quantified apoptosis, mitosis, crypt depth, villus height, and crypt density. Immunostaining for muc2 and lysozyme evaluated Paneth cells, goblet cells or dual stained intermediate cells. DOXO administration induced significant increases in apoptosis in jejunal epithelium regardless of the presence of enteric bacteria; however, the resulting injury, as demonstrated by statistically significant changes in crypt depth, crypt number, and proliferative cell number, was dependent upon the presence of enteric bacteria. Furthermore, we observed expansion of Paneth and goblet cells and presence of intermediate cells only in CONV and not GF mice. These findings provide evidence that manipulation and/or depletion of the enteric microbiota may have clinical significance in limiting chemotherapy-induced mucositis.

Liability of professional and volunteer mental health practitioners in the wake of disasters: a framework for further considerations.

PubMed

Abdel-Monem, Tarik; Bulling, Denise

2005-01-01

Qualified immunity from civil liability exists for acts of disaster mental health (DMH) practitioners responding to disasters or acts of terrorism. This article reviews current legal regimens dictating civil liability for potentially wrongful acts of DMH professionals and volunteers responding to disasters. Criteria are proposed to inform determinations of civil liability for DMH workers in disaster response, given current legal parameters and established tort law in relevant areas. Specific considerations are examined that potentially implicate direct liability of DMH professionals and volunteers, and vicarious liability of DMH supervisors for actions of volunteer subordinates. The relevance of pre-event DMH planning and operationalization of the plan post-event is linked to considerations of liability. This article concludes with recommendations to minimize liability exposure for DMH workers in response efforts.

Effective chemotherapy of heterogeneous and drug-resistant early colon cancers by intermittent dose schedules: a computer simulation study.

PubMed

Axelrod, David E; Vedula, Sudeepti; Obaniyi, James

2017-05-01

The effectiveness of cancer chemotherapy is limited by intra-tumor heterogeneity, the emergence of spontaneous and induced drug-resistant mutant subclones, and the maximum dose to which normal tissues can be exposed without adverse side effects. The goal of this project was to determine if intermittent schedules of the maximum dose that allows colon crypt maintenance could overcome these limitations, specifically by eliminating mixtures of drug-resistant mutants from heterogeneous early colon adenomas while maintaining colon crypt function. A computer model of cell dynamics in human colon crypts was calibrated with measurements of human biopsy specimens. The model allowed simulation of continuous and intermittent dose schedules of a cytotoxic chemotherapeutic drug, as well as the drug's effect on the elimination of mutant cells and the maintenance of crypt function. Colon crypts can tolerate a tenfold greater intermittent dose than constant dose. This allows elimination of a mixture of relatively drug-sensitive and drug-resistant mutant subclones from heterogeneous colon crypts. Mutants can be eliminated whether they arise spontaneously or are induced by the cytotoxic drug. An intermittent dose, at the maximum that allows colon crypt maintenance, can be effective in eliminating a heterogeneous mixture of mutant subclones before they fill the crypt and form an adenoma.

An APC:WNT Counter-Current-Like Mechanism Regulates Cell Division Along the Human Colonic Crypt Axis: A Mechanism That Explains How APC Mutations Induce Proliferative Abnormalities That Drive Colon Cancer Development

PubMed Central

Boman, Bruce M.; Fields, Jeremy Z.

2013-01-01

APC normally down-regulates WNT signaling in human colon, and APC mutations cause proliferative abnormalities in premalignant crypts leading to colon cancer, but the mechanisms are unclear at the level of spatial and functional organization of the crypt. Accordingly, we postulated a counter-current-like mechanism based on gradients of factors (APC;WNT) that regulate colonocyte proliferation along the crypt axis. During crypt renewal, stem cells (SCs) at the crypt bottom generate non-SC daughter cells that proliferate and differentiate while migrating upwards. The APC concentration is low at the crypt bottom and high at the top (where differentiated cells reside). WNT signaling, in contrast, is high at the bottom (where SCs reside) and low at the top. Given that WNT and APC gradients are counter to one another, we hypothesized that a counter-current-like mechanism exists. Since both APC and WNT signaling components (e.g., survivin) are required for mitosis, this mechanism establishes a zone in the lower crypt where conditions are optimal for maximal cell division and mitosis orientation (symmetric versus asymmetric). APC haploinsufficiency diminishes the APC gradient, shifts the proliferative zone upwards, and increases symmetric division, which causes SC overpopulation. In homozygote mutant crypts, these changes are exacerbated. Thus, APC-mutation-induced changes in the counter-current-like mechanism cause expansion of proliferative populations (SCs, rapidly proliferating cells) during tumorigenesis. We propose this mechanism also drives crypt fission, functions in the crypt cycle, and underlies adenoma development. Novel chemoprevention approaches designed to normalize the two gradients and readjust the proliferative zone downwards, might thwart progression of these premalignant changes. PMID:24224156

Neural control of colonic cell proliferation.

PubMed

Tutton, P J; Barkla, D H

1980-03-15

The mitotic rate in rat colonic crypts and in dimethylhydrazine-induced colonic carcinomas was measured using a stathmokinetic technique. In sympathectomized animals cell proliferation was retarded in the crypts but not in the tumors, whereas in animals treated with Metaraminol, a drug which releases norepinephrine from nerve terminals, crypt cell but not tumor cell proliferation was accelerated. Blockade of alpha-adrenoceptors also inhibited crypt cell proliferation. However, stimulation of beta-adrenoceptors inhibited and blockade of beta-adrenoceptors accelerated tumor cell proliferation without influencing crypt cell proliferation. Injection of either serotonin or histamine stimulated tumor but not crypt cell proliferation and blockade or serotonin receptors or histamine H2-receptors inhibited tumor cell proliferation. It is postulated that cell proliferation in the colonic crypts, like that in the jejunal crypts, is under both endocrine and autonomic neural control whereas colonic tumor cell division is subject to endocrine regulation alone.

Toll-like Receptor 4-mediated Endoplasmic Reticulum Stress in Intestinal Crypts Induces Necrotizing Enterocolitis*

PubMed Central

Afrazi, Amin; Branca, Maria F.; Sodhi, Chhinder P.; Good, Misty; Yamaguchi, Yukihiro; Egan, Charlotte E.; Lu, Peng; Jia, Hongpeng; Shaffiey, Shahab; Lin, Joyce; Ma, Congrong; Vincent, Garrett; Prindle, Thomas; Weyandt, Samantha; Neal, Matthew D.; Ozolek, John A.; Wiersch, John; Tschurtschenthaler, Markus; Shiota, Chiyo; Gittes, George K.; Billiar, Timothy R.; Mollen, Kevin; Kaser, Arthur; Blumberg, Richard; Hackam, David J.

2014-01-01

The cellular cues that regulate the apoptosis of intestinal stem cells (ISCs) remain incompletely understood, yet may play a role in diseases characterized by ISC loss including necrotizing enterocolitis (NEC). Toll-like receptor-4 (TLR4) was recently found to be expressed on ISCs, where its activation leads to ISC apoptosis through mechanisms that remain incompletely explained. We now hypothesize that TLR4 induces endoplasmic reticulum (ER) stress within ISCs, leading to their apoptosis in NEC pathogenesis, and that high ER stress within the premature intestine predisposes to NEC development. Using transgenic mice and cultured enteroids, we now demonstrate that TLR4 induces ER stress within Lgr5 (leucine-rich repeat-containing G-protein-coupled receptor 5)-positive ISCs, resulting in crypt apoptosis. TLR4 signaling within crypts was required, because crypt ER stress and apoptosis occurred in TLR4ΔIEC-OVER mice expressing TLR4 only within intestinal crypts and epithelium, but not TLR4ΔIEC mice lacking intestinal TLR4. TLR4-mediated ER stress and apoptosis of ISCs required PERK (protein kinase-related PKR-like ER kinase), CHOP (C/EBP homologous protein), and MyD88 (myeloid differentiation primary response gene 88), but not ATF6 (activating transcription factor 6) or XBP1 (X-box-binding protein 1). Human and mouse NEC showed high crypt ER stress and apoptosis, whereas genetic inhibition of PERK or CHOP attenuated ER stress, crypt apoptosis, and NEC severity. Strikingly, using intragastric delivery into fetal mouse intestine, prevention of ER stress reduced TLR4-mediated ISC apoptosis and mucosal disruption. These findings identify a novel link between TLR4-induced ER stress and ISC apoptosis in NEC pathogenesis and suggest that increased ER stress within the premature bowel predisposes to NEC development. PMID:24519940

Toll-like receptor 4-mediated endoplasmic reticulum stress in intestinal crypts induces necrotizing enterocolitis.

PubMed

Afrazi, Amin; Branca, Maria F; Sodhi, Chhinder P; Good, Misty; Yamaguchi, Yukihiro; Egan, Charlotte E; Lu, Peng; Jia, Hongpeng; Shaffiey, Shahab; Lin, Joyce; Ma, Congrong; Vincent, Garrett; Prindle, Thomas; Weyandt, Samantha; Neal, Matthew D; Ozolek, John A; Wiersch, John; Tschurtschenthaler, Markus; Shiota, Chiyo; Gittes, George K; Billiar, Timothy R; Mollen, Kevin; Kaser, Arthur; Blumberg, Richard; Hackam, David J

2014-04-04

The cellular cues that regulate the apoptosis of intestinal stem cells (ISCs) remain incompletely understood, yet may play a role in diseases characterized by ISC loss including necrotizing enterocolitis (NEC). Toll-like receptor-4 (TLR4) was recently found to be expressed on ISCs, where its activation leads to ISC apoptosis through mechanisms that remain incompletely explained. We now hypothesize that TLR4 induces endoplasmic reticulum (ER) stress within ISCs, leading to their apoptosis in NEC pathogenesis, and that high ER stress within the premature intestine predisposes to NEC development. Using transgenic mice and cultured enteroids, we now demonstrate that TLR4 induces ER stress within Lgr5 (leucine-rich repeat-containing G-protein-coupled receptor 5)-positive ISCs, resulting in crypt apoptosis. TLR4 signaling within crypts was required, because crypt ER stress and apoptosis occurred in TLR4(ΔIEC-OVER) mice expressing TLR4 only within intestinal crypts and epithelium, but not TLR4(ΔIEC) mice lacking intestinal TLR4. TLR4-mediated ER stress and apoptosis of ISCs required PERK (protein kinase-related PKR-like ER kinase), CHOP (C/EBP homologous protein), and MyD88 (myeloid differentiation primary response gene 88), but not ATF6 (activating transcription factor 6) or XBP1 (X-box-binding protein 1). Human and mouse NEC showed high crypt ER stress and apoptosis, whereas genetic inhibition of PERK or CHOP attenuated ER stress, crypt apoptosis, and NEC severity. Strikingly, using intragastric delivery into fetal mouse intestine, prevention of ER stress reduced TLR4-mediated ISC apoptosis and mucosal disruption. These findings identify a novel link between TLR4-induced ER stress and ISC apoptosis in NEC pathogenesis and suggest that increased ER stress within the premature bowel predisposes to NEC development.

Leptin Mediates the Increase in Blood Pressure Associated with Obesity

PubMed Central

Simonds, Stephanie E.; Pryor, Jack T.; Ravussin, Eric; Greenway, Frank L.; Dileone, Ralph; Allen, Andrew M.; Bassi, Jaspreet; Elmquist, Joel K.; Keogh, Julia M.; Henning, Elana; Myers, Martin G.; Licinio, Julio; Brown, Russell D.; Enriori, Pablo J.; O’Rahilly, Stephen; Sternson, Scott M.; Grove, Kevin L.; Spanswick, David C.; Farooqi, I. Sadaf; Cowley, Michael A.

2014-01-01

Summary Obesity is associated with increased blood pressure (BP), which in turn increases the risk of cardiovascular diseases. We found that the increase in leptin levels seen in diet-induced obesity (DIO) drives an increase in BP in rodents, an effect that was not seen in animals deficient in leptin or leptin receptors (LepR). Furthermore, humans with loss-of-function mutations in leptin and the LepR have low BP despite severe obesity. Leptin’s effects on BP are mediated by neuronal circuits in the dorsomedial hypothalamus (DMH), as blocking leptin with a specific antibody, antagonist, or inhibition of the activity of LepR-expressing neurons in the DMH caused a rapid reduction of BP in DIO mice, independent of changes in weight. Re-expression of LepRs in the DMH of DIO LepR-deficient mice caused an increase in BP. These studies demonstrate that leptin couples changes in weight to changes in BP in mammalian species. PMID:25480301

Celecoxib prevents colitis associated colon carcinogenesis: an upregulation of apoptosis.

PubMed

Setia, Shruti; Nehru, Bimla; Sanyal, Sankar N

2014-12-01

Uncontrolled cell proliferation and suppressed apoptosis are the critical events transforming a normal cell to a cancerous one wherein the inflammatory microenvironment supports this oncogenic transformation. The process of colon carcinogenesis may be aggravated in chronic inflammatory conditions such as ulcerative colitis where non-steroidal anti-inflammatory drugs (NSAIDs) may effectively prevent the cellular and molecular events. Western blots and immunofluorescent analysis of DNA mismatch repair enzymes, cell cycle regulators and pro- and anti-apoptotic proteins were performed in dextran sulfate sodium (DSS)-induced ulcerative colitis and 1,2-dimethyl benz(a)anthracene (DMH)-induced colon cancer. Also, apoptotic studies were done in isolated colonocytes using fluorescent staining and in paraffin sections using TUNEL assay. An upregulation of cell cycle regulators: cyclin D1/cdk4 and cyclin E/cdk2 and anti-apoptotic Bcl-2, along with the suppression of DNA repair enzymes: MLH1 and MSH2; tumour suppressors: p53, p21and Rb and pro-apoptotic proteins: Bax and Bad were observed in the DSS, DMH and DSS+DMH groups. Proliferating cell nuclear antigen (PCNA) was also overexpressed in these groups. The ultimate executioner of the apoptotic pathway; caspase-3, was suppressed in these groups. Apoptotic studies in colonocytes and paraffin sections revealed suppressed apoptosis in these groups. These effects were corrected with the administration of a second generation NSAID, celecoxib along with the treatment of DSS and DMH. The chemopreventive action of celecoxib in colitis mediated colon carcinogenesis may include the regulation of DNA mismatch repair enzymes, cell cycle check points, cell proliferation and apoptosis. Copyright © 2014 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

[Curcumin inhibited rat colorectal carcinogenesis by activating PPAR-γ: an experimental study].

PubMed

Liu, Liu-bin; Duan, Chang-nong; Ma, Zeng-yi; Xu, Gang

2015-04-01

To explore the chemopreventive effect of curcumin on DMH induced colorectal carcinogenesis and the underlining mechanism. Totally 40 Wistar rats were divided into the model group and the curcumin group by random digit table, 20 in each group. Meanwhile, a normal control group was set up (n =10). A colorectal cancer model was induced by subcutaneously injecting 20 mg/kg DMH. The tumor incidence and the inhibition rate were calculated. The effect of curcumin on the expression of peroxisome proliferator-activated receptor gamma (PPARγ) in rat colon mucosal tissues was observed using immunohistochemistry and Western blot. HT 29 cell line were cultured and divided into a control group, the curcumin + GW9662 (2-chloro-5-nitro-N-4-phenylbenzamide) intervention group, and the curcumin group. The inhibition of different concentrations curcumin on HT29 cell line was detected using MTT. The expression of curcumin on PPARy was also detected using Western blot. The tumor incidence was 80. 00% (12/15 cases) in the model group, obviously higher than that of the curcumin group (58. 82%, 10/17 cases, P <0. 05). The inhibition rate of curcumin on DMH induced colorected carcinoma reached 26. 46%. Compared with the normal control group, the expression of PPARγ protein was significantly increased in the curcumin group and the model group (P <0. 01). Compared with the model group at the same time point, the expression of PPARy protein was significantly enhanced in the curcumin group (P <0. 05). MTT analysis showed that curcumin could inhibit the proliferation of in vitro HT 29 cells in dose and time dependent manners. The expression of PPARy protein was significantly increased in the GW9662 group and the curcumin group, showing statistical difference when compared with the normal control group (P <0. 01). Compared with the GW9662 group, the expression of PPARγ protein was significantly increased in the curcumin group (P <0. 01). Curcumin could inhibit DMH-induced rat colorectal carcinogenesis and the growth of in vitro cultured HT 29 cell line, which might be achieved by activating PPARy signal transduction pathway.

INDUCTION OF TRANSTITIONAL CELL HYPERPLASIA IN THE URINARY BLADDER AND ABERRANT CRYPT FOCI IN THE COLON OF RATS TREATED WITH INDIVIDUAL AND A MIXTURE OF DRINKING WATER DISINFECTION BY-PRODUCTS

EPA Science Inventory

ABSTRACT

Cancer of the urinary bladder and colon are significant human health concerns. Epidemiological studies have suggested a correlation between these cancers and the chronic consumption of drinking water containing disinfection by-products (DBPs). The present study...

TRIBROMOMETHANE EXPOSURE AND DIETARY FOLATE DEFICIENCY IN THE FORMATION OF ABERRANT CRYPT FOCI IN THE COLONS OF F344/N RATS

EPA Science Inventory

Folate and folic acid are forms of the B vitamin that are involved in the synthesis, repair and functioning of DNA and are required for the production and maintenance of cells. Low levels of folate have been associated with several forms of cancer, including colon cancer. Aberran...

Leptin action in the dorsomedial hypothalamus increases sympathetic tone to brown adipose tissue in spite of systemic leptin resistance.

PubMed

Enriori, Pablo J; Sinnayah, Puspha; Simonds, Stephanie E; Garcia Rudaz, Cecilia; Cowley, Michael A

2011-08-24

Leptin regulates body weight in mice by decreasing appetite and increasing sympathetic nerve activity (SNA), which increases energy expenditure in interscapular brown adipose tissue (iBAT). Diet-induced obese mice (DIO) are resistant to the anorectic actions of leptin. We evaluated whether leptin still stimulated sympathetic outflow in DIO mice. We measured iBAT temperature as a marker of SNA. We found that obese hyperleptinemic mice have higher iBAT temperature than mice on regular diet. Conversely, obese leptin-deficient ob/ob mice have lower iBAT temperature. Additionally, leptin increased SNA in obese (DIO and ob/ob) and control mice, despite DIO mice being resistant to anorectic action of leptin. We demonstrated that neurons in the dorsomedial hypothalamus (DMH) of DIO mice mediate the thermogenic responses to hyperleptinemia in obese mammals because blockade of leptin receptors in the DMH prevented the thermogenic effects of leptin. Peripheral Melotan II (MTII) injection increased iBAT temperature, but it was blunted by blockade of DMH melanocortin receptors (MC4Rs) by injecting agouti-related peptide (AgRP) directly into the DMH, suggesting a physiological role of the DMH on temperature regulation in animals with normal body weight. Nevertheless, obese mice without a functional melanocortin system (MC4R KO mice) have an increased sympathetic outflow to iBAT compared with their littermates, suggesting that higher leptin levels drive sympathoexcitation to iBAT by a melanocortin-independent pathway. Because the sympathetic nervous system contributes in regulating blood pressure, heart rate, and hepatic glucose production, selective leptin resistance may be a crucial mechanism linking adiposity and metabolic syndrome.

The role of dorsomedial hypotalamus ionotropic glutamate receptors in the hypertensive and tachycardic responses evoked by Tityustoxin intracerebroventricular injection.

PubMed

Silva, F C; Guidine, Patrícia Alves Maia; Machado, Natalia Lima; Xavier, Carlos Henrique; de Menezes, R C; Moraes-Santos, Tasso; Moraes, Márcio Flávio; Chianca, Deoclécio Alves

2015-03-01

The scorpion envenoming syndrome is an important worldwide public health problem due to its high incidence and potential severity of symptoms. Some studies address the high sensitivity of the central nervous system to this toxin action. It is known that cardiorespiratory manifestations involve the activation of the autonomic nervous system. However, the origin of this modulation remains unclear. Considering the important participation of the dorsomedial hypotalamus (DMH) in the cardiovascular responses during emergencial situations, the aim of this work is to investigate the involvement of the DMH on cardiovascular responses induced by intracerebroventricular (icv) injection of Tityustoxin (TsTX, a α-type toxin extracted from the Tityus serrulatus scorpion venom). Urethane-anaesthetized male Wistar rats (n=30) were treated with PBS, muscimol or ionotropic glutamate receptor antagonists, bilaterally in DMH and later, with an icv injection of TsTX, or treated only with PBS in both regions. TsTX evoked a marked increase in mean arterial pressure and heart rate in all control rats. Interestingly, injection of muscimol, a GABAA receptor agonist, did not change the pressor and tachycardic responses evoked by TsTX. Remarkably, the injection ionotropic glutamate receptors antagonists in DMH abolished the pressor and the tachycardic response evoked by TsTX. Our data suggest that the central circuit recruited by TsTX, whose activation results in an array of physiological and behavioral alterations, depend on the activation of DMH ionotropic glutamate receptors. Moreover, our data provide new insights on the central mechanisms involved in the development of symptoms in the severe scorpion envenomation syndrome. Copyright © 2014 Elsevier Inc. All rights reserved.

Dose to mass for evaluation and optimization of lung cancer radiation therapy.

PubMed

Tyler Watkins, William; Moore, Joseph A; Hugo, Geoffrey D; Siebers, Jeffrey V

2017-11-01

To evaluate potential organ at risk dose-sparing by using dose-mass-histogram (DMH) objective functions compared with dose-volume-histogram (DVH) objective functions. Treatment plans were retrospectively optimized for 10 locally advanced non-small cell lung cancer patients based on DVH and DMH objectives. DMH-objectives were the same as DVH objectives, but with mass replacing volume. Plans were normalized to dose to 95% of the PTV volume (PTV-D95v) or mass (PTV-D95m). For a given optimized dose, DVH and DMH were intercompared to ascertain dose-to-volume vs. dose-to-mass differences. Additionally, the optimized doses were intercompared using DVH and DMH metrics to ascertain differences in optimized plans. Mean dose to volume, D v ‾, mean dose to mass, D M ‾, and fluence maps were intercompared. For a given dose distribution, DVH and DMH differ by >5% in heterogeneous structures. In homogeneous structures including heart and spinal cord, DVH and DMH are nearly equivalent. At fixed PTV-D95v, DMH-optimization did not significantly reduce dose to OARs but reduced PTV-D v ‾ by 0.20±0.2Gy (p=0.02) and PTV-D M ‾ by 0.23±0.3Gy (p=0.02). Plans normalized to PTV-D95m also result in minor PTV dose reductions and esophageal dose sparing (D v ‾ reduced 0.45±0.5Gy, p=0.02 and D M ‾ reduced 0.44±0.5Gy, p=0.02) compared to DVH-optimized plans. Optimized fluence map comparisons indicate that DMH optimization reduces dose in the periphery of lung PTVs. DVH- and DMH-dose indices differ by >5% in lung and lung target volumes for fixed dose distributions, but optimizing DMH did not reduce dose to OARs. The primary difference observed in DVH- and DMH-optimized plans were variations in fluence to the periphery of lung target PTVs, where low density lung surrounds tumor. Copyright © 2017 Elsevier B.V. All rights reserved.

Gamma-irradiation enhances apoptosis induced by cannabidiol, a non-psychotropic cannabinoid, in cultured HL-60 myeloblastic leukemia cells.

PubMed

Gallily, Ruth; Even-Chena, Tal; Katzavian, Galia; Lehmann, Dan; Dagan, Arie; Mechoulam, Raphael

2003-10-01

Two non-psychotropic cannabinoids, cannabidiol (CBD) and cannabidiol-dimethylheptyl (CBD-DMH), induced apoptosis in a human acute myeloid leukemia (AML) HL-60 cell line. Apoptosis was determined by staining with bisBenzimide and propidium iodide. A dose dependent increase of apoptosis was noted, reaching 61 and 43% with 8 microg/ml CBD and 15 microg/ml CBD-DMH, respectively, after a 24 h treatment. Prior exposure of the cells to gamma-irradiation (800 cGy) markedly enhanced apoptosis, reaching values of 93 and 95%, respectively. Human monocytes from normal individuals were resistant to either cannabinoids or gamma-irradiation. Caspase-3 activation was observed after the cannabinoid treatment, and may represent a mechanism for the apoptosis. Our data suggest a possible new approach to treatment of AML.

Autoradiographic study on healing process of cysteamine-induced duodenal ulcer in rat. Possible importance of Brunner's glands in ulcer healing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fuse, Y.; Tsuchihashi, Y.; Sugihara, H.

1988-09-01

The healing process of cysteamine-induced duodenal ulcer was studied by (/sup 3/H)thymidine autoradiography. After the development of ulcer in the duodenum, cell proliferation was markedly activated not only in the crypts but also in the Brunner's glands near the ulcer. In the initial stages of ulcer healing, they both contributed to form the surface covering regenerating epithelium. Granulation tissue also proliferated at the base of the ulcer. In later stages of ulcer healing, new crypts were formed in the floor of the ulcer. New villi regenerated from these crypts and Brunner's glands regenerated by proliferation in situ. The ulcer basemore » then was completely covered with new villi and granulation tissue was replaced by dense fibrous connective tissue. The present study suggested that the Brunner's glands, together with the crypts of Lieberkuehn, play an important role in the healing process of cysteamine-induced duodenal ulcer.« less

Central transthyretin acts to decrease food intake and body weight

PubMed Central

Zheng, Fenping; Kim, Yonwook J.; Moran, Timothy H.; Li, Hong; Bi, Sheng

2016-01-01

Transthyretin (TTR) is a blood and cerebrospinal fluid transporter of thyroxine and retinol. Gene expression profiling revealed an elevation of Ttr expression in the dorsomedial hypothalamus (DMH) of rats with exercise-induced anorexia, implying that central TTR may also play a functional role in modulating food intake and energy balance. To test this hypothesis, we have examined the effects of brain TTR on food intake and body weight and have further determined hypothalamic signaling that may underlie its feeding effect in rats. We found that intracerebroventricular (icv) administration of TTR in normal growing rats decreased food intake and body weight. This effect was not due to sickness as icv TTR did not cause a conditioned taste aversion. ICV TTR decreased neuropeptide Y (NPY) levels in the DMH and the paraventricular nucleus (P < 0.05). Chronic icv infusion of TTR in Otsuka Long-Evans Tokushima Fatty rats reversed hyperphagia and obesity and reduced DMH NPY levels. Overall, these results demonstrate a previously unknown anorectic action of central TTR in the control of energy balance, providing a potential novel target for treating obesity and its comorbidities. PMID:27053000

APIGENIN AND NARINGENIN SUPPRESS COLON CARCINOGENESIS THROUGH THE ABERRANT CRYPT STAGE IN AZOXYMETHANE-TREATED RATS1

PubMed Central

Leonardi, Tety; Vanamala, Jairam; Taddeo, Stella S.; Davidson, Laurie A.; Murphy, Mary E.; Patil, Bhimanagouda S.; Wang, Naisyin; Carroll, Raymond J.; Chapkin, Robert S.; Lupton, Joanne R.; Turner, Nancy D.

2010-01-01

Epidemiological evidence suggests that a diet abundant in fruits and vegetables may protect against colon cancer. Bioactive compounds, including flavonoids and limonoids, have been shown to possess anti-proliferative and anti-tumorigenic effects in various cancer models. This experiment investigated the effects of four citrus flavonoids and one limonoid mixture at the promotion stage of chemically induced colon cancer in rats. Male Sprague Dawley rats (n = 10 rats/group) were randomly allocated to one of six diets formulated to contain 0.1% apigenin, 0.02% naringenin, 0.1% hesperidin, 0.01% nobiletin, 0.035% limonin glucoside/obacunone glucoside mixture, or a control diet (0% flavonoid/limonoid). Rats received experimental diets for 10 wk and were injected with azoxymethane (15 mg/kg) at wk 3 and 4. Excised colons were evaluated for aberrant crypt foci (ACF) formation, colonocyte proliferation (PCNA assay), apoptosis (TUNEL assay), and expression of iNOS and COX-2 (immunoblotting). When compared to the control diet, apigenin lowered the number of high multiplicity ACF (HMACF > 4 AC/focus) by 57% (P < 0.05), while naringenin lowered both the number of HMACF by 51% (P < 0.05) and the proliferative index by 32% (P < 0.05). Both apigenin and naringenin increased apoptosis of luminal surface colonocytes (78% and 97%, respectively; P < 0.05) when compared to the control diet. Hesperidin, nobiletin, and the limonin glucoside/obacunone glucoside mixture did not affect these variables. The colonic mucosal protein levels of iNOS or COX-2 were not different among the six diet groups. The ability of dietary apigenin and naringenin to reduce HMACF, lower proliferation (naringenin only), and increase apoptosis may contribute toward colon cancer prevention. However, these effects were not due to mitigation of iNOS and COX-2 protein levels at the ACF stage of colon cancer. PMID:20511675

Pre- and Postnatal Determinants of Deciduous Molar Hypomineralisation in 6-Year-Old Children. The Generation R Study

PubMed Central

Elfrink, Marlies E. C.; Moll, Henriette A.; Kiefte-de Jong, Jessica C.; Jaddoe, Vincent W. V.; Hofman, Albert; ten Cate, Jacob M.; Veerkamp, Jaap S. J.

2014-01-01

Background Deciduous Molar Hypomineralisation (DMH) and Molar Incisor Hypomineralisation (MIH) are common developmental disturbances in pediatric dentistry. Their occurrence is related. The same determinants as suggested for MIH are expected for DMH, though somewhat earlier in life. Perinatal medical problems may influence the prevalence of DMH but this has not been studied sufficiently. Objective This study aimed to identify possible determinants of DMH in a prospective cohort study among 6-year-old children. Study Design This study was embedded in the Generation R Study, a population-based prospective cohort study from fetal life until young adulthood. The the data were used to identify the determinants of DMH. Clinical photographs of clean, moist teeth were taken with an intra-oral camera in 6690 children (mean age 6.2 years; 49.9% girls). Data on possible determinants that had occurred during pregnancy and/or the child's first year of life were on the basis of manual standardized measurements (like length and weight) and questionnaires. Multivariate analyse with backward and forward selection was performed. Results A number of factors in the pre-, peri- and postnatal phase were found to be associated with DMH. After multivariate logistic regression analyses, Dutch ethnic background, low birth weight, maternal alcohol consumption during pregnancy, and fever episodes in the first year of the child's life were found to play a role in the development of DMH in 6-year-old children. Conclusion This study shows that Dutch ethnicity, low birth weight, alcohol consumption by the mother during pregnancy and any fever in the first year of the child's life are associated with DMH. Not only childhood factors but also prenatal lifestyle factors need to be taken into account when studying determinants for DMH. PMID:24988443

The influence of surgical transection and anastomosis on the rate of cell proliferation in the colonic epithelium of normal and DMH-treated rats.

PubMed

Barkla, D H; Tutton, P M

1983-10-01

Normal and DMH-treated male rats aged 18-20 weeks underwent surgical transection and anastomosis of the transverse colon. Animals were subsequently killed at intervals of 14, 30 and 72 days. Three hours prior to sacrifice animals were injected with vinblastine sulphate and mitotic indices were subsequently estimated in histological sections. Possible differences between experimental and control groups were tested using a Student's t-test. The results show that the accumulated mitotic indices in normal and DMH-treated colon are statistically similar. The results also show that transection and anastomosis stimulates cell division in both normal and DMH-treated colon and that the increase is of greater amplitude and more prolonged duration in the DMH-treated rats. Carcinomas developed close to the line of anastomosis in DMH-treated but not in control rats. The results support the hypothesis that non-specific injury to hyperplastic colonic epithelium promotes carcinogenesis.

Hotspots of aberrant enhancer activity punctuate the colorectal cancer epigenome

PubMed Central

Cohen, Andrea J.; Saiakhova, Alina; Corradin, Olivia; Luppino, Jennifer M.; Lovrenert, Katreya; Bartels, Cynthia F.; Morrow, James J.; Mack, Stephen C.; Dhillon, Gursimran; Beard, Lydia; Myeroff, Lois; Kalady, Matthew F.; Willis, Joseph; Bradner, James E.; Keri, Ruth A.; Berger, Nathan A.; Pruett-Miller, Shondra M.; Markowitz, Sanford D.; Scacheri, Peter C.

2017-01-01

In addition to mutations in genes, aberrant enhancer element activity at non-coding regions of the genome is a key driver of tumorigenesis. Here, we perform epigenomic enhancer profiling of a cohort of more than forty genetically diverse human colorectal cancer (CRC) specimens. Using normal colonic crypt epithelium as a comparator, we identify enhancers with recurrently gained or lost activity across CRC specimens. Of the enhancers highly recurrently activated in CRC, most are constituents of super enhancers, are occupied by AP-1 and cohesin complex members, and originate from primed chromatin. Many activate known oncogenes, and CRC growth can be mitigated through pharmacologic inhibition or genome editing of these loci. Nearly half of all GWAS CRC risk loci co-localize to recurrently activated enhancers. These findings indicate that the CRC epigenome is defined by highly recurrent epigenetic alterations at enhancers which activate a common, aberrant transcriptional programme critical for CRC growth and survival. PMID:28169291

Uncovering Molecular Bases Underlying Bone Morphogenetic Protein Receptor Inhibitor Selectivity

PubMed Central

Alsamarah, Abdelaziz; LaCuran, Alecander E.; Oelschlaeger, Peter; Hao, Jijun; Luo, Yun

2015-01-01

Abnormal alteration of bone morphogenetic protein (BMP) signaling is implicated in many types of diseases including cancer and heterotopic ossifications. Hence, small molecules targeting BMP type I receptors (BMPRI) to interrupt BMP signaling are believed to be an effective approach to treat these diseases. However, lack of understanding of the molecular determinants responsible for the binding selectivity of current BMP inhibitors has been a big hindrance to the development of BMP inhibitors for clinical use. To address this issue, we carried out in silico experiments to test whether computational methods can reproduce and explain the high selectivity of a small molecule BMP inhibitor DMH1 on BMPRI kinase ALK2 vs. the closely related TGF-β type I receptor kinase ALK5 and vascular endothelial growth factor receptor type 2 (VEGFR2) tyrosine kinase. We found that, while the rigid docking method used here gave nearly identical binding affinity scores among the three kinases; free energy perturbation coupled with Hamiltonian replica-exchange molecular dynamics (FEP/H-REMD) simulations reproduced the absolute binding free energies in excellent agreement with experimental data. Furthermore, the binding poses identified by FEP/H-REMD led to a quantitative analysis of physical/chemical determinants governing DMH1 selectivity. The current work illustrates that small changes in the binding site residue type (e.g. pre-hinge region in ALK2 vs. ALK5) or side chain orientation (e.g. Tyr219 in caALK2 vs. wtALK2), as well as a subtle structural modification on the ligand (e.g. DMH1 vs. LDN193189) will cause distinct binding profiles and selectivity among BMP inhibitors. Therefore, the current computational approach represents a new way of investigating BMP inhibitors. Our results provide critical information for designing exclusively selective BMP inhibitors for the development of effective pharmacotherapy for diseases caused by aberrant BMP signaling. PMID:26133550

Activation of 5-HT1A receptors in the rat dorsomedial hypothalamus inhibits stress-induced activation of the hypothalamic-pituitary-adrenal axis.

PubMed

Stamper, Christopher E; Hassell, James E; Kapitz, Adam J; Renner, Kenneth J; Orchinik, Miles; Lowry, Christopher A

2017-03-01

Acute activation of the hypothalamic-pituitary-adrenal (HPA) axis, leading to the release of corticosteroid hormones into the circulation, is an adaptive response to perceived threats. Persistent activation of the HPA axis can lead to impaired physiological or behavioral function with maladaptive consequences. Thus, efficient control and termination of stress responses is essential for well-being. However, inhibitory control mechanisms governing the HPA axis are poorly understood. Previous studies suggest that serotonergic systems, acting within the medial hypothalamus, play an important role in inhibitory control of stress-induced HPA axis activity. To test this hypothesis, we surgically implanted chronic jugular cannulae in adult male rats and conducted bilateral microinjection of vehicle or the 5-HT 1A receptor agonist, 8-hydroxy-2-(di-n-propylamino) tetralin hydrobromide (8-OH-DPAT; 8 nmol, 0.2 μL, 0.1 μL/min, per side) into the dorsomedial hypothalamus (DMH) immediately prior to a 40 min period of restraint stress. Repeated blood sampling was conducted using an automated blood sampling system and plasma corticosterone concentrations were determined using enzyme-linked immunosorbent assay. Bilateral intra-DMH microinjections of 8-OH-DPAT suppressed stress-induced increases in plasma corticosterone within 10 min of the onset of handling prior to restraint and, as measured by area-under-the-curve analysis of plasma corticosterone concentrations, during the 40 min period of restraint. These data support an inhibitory role for serotonergic systems, acting within the DMH, on stress-induced activation of the HPA axis. Lay summary: Inhibitory control of the hypothalamic-pituitary-adrenal (HPA) stress hormone response is important for well-being. One neurochemical implicated in inhibitory control of the HPA axis is serotonin. In this study we show that activation of serotonin receptors, specifically inhibitory 5-HT 1A receptors in the dorsomedial hypothalamus, is sufficient to inhibit stress-induced HPA axis activity in rats.

Effects of 5-Amyno-4-(1,3-benzothyazol-2-yn)-1-(3-methoxyphenyl)-1,2-dihydro-3H-pyrrol-3-one Intake on Digestive System in a Rat Model of Colon Cancer.

PubMed

Kuznietsova, Halyna M; Luzhenetska, Valentyna K; Kotlyar, Iryna P; Rybalchenko, Volodymyr K

2015-01-01

Pyrrol derivate 5-amyno-4-(1,3-benzothyazol-2-yn)-1-(3-methoxyphenyl)-1,2-dihydro-3H-pyrrol-3-one (D1) has shown antiproliferative activities in vitro, so investigation of the impact of D1 intake on gut organs in rats that experienced colon cancer seems to be necessary. D1 at the dose of 2.3 mg/kg was administered per os daily for 27 (from the 1st day of experiment) or 7 (from the 21st week of experiment) weeks to rats that experienced 1,2-dimethylhydrazine (DMH)-induced colon cancer for 20 weeks. 5-Fluorouracil (5FU) was chosen as reference drug and was administered intraperitoneally weekly for 7 weeks (from the 21st week of experiment) at the dose of 45 mg/kg. Antitumor activity of D1 comparable with the 5FU one against DMH-induced colon cancer in rats was observed (decrease of tumor number and tumor total area up to 46%). D1 attenuated the inflammation of colon, gastric and jejunal mucosa, and the liver, caused by DMH, unlike 5FU, aggravating the latter. In addition, D1 partially normalized mucosa morphometric parameters suggesting its functional restore. D1 possesses, comparable with 5-fluorouracil antitumor efficacy, less damaging effects on the tissues beyond cancerous areas and contributes to partial morphological and functional gut organs recovery.

Colon cancer chemoprevention by a novel NO chimera that shows anti-inflammatory and antiproliferative activity in vitro and in vivo.

PubMed

Hagos, Ghenet K; Carroll, Robert E; Kouznetsova, Tatiana; Li, Qian; Toader, Violeta; Fernandez, Patricia A; Swanson, Steven M; Thatcher, Gregory R J

2007-08-01

Chemopreventive agents in colorectal cancer possess either antiproliferative or anti-inflammatory actions. Nonsteroidal anti-inflammatory drugs (NSAID) and cyclooxygenase-2 inhibitors have shown promise, but are compromised by side effects. Nitric oxide donor NSAIDs are organic nitrates conjugated via a labile linker to an NSAID, originally designed for use in pain relief, that have shown efficacy in colorectal cancer chemoprevention. The NO chimera, GT-094, is a novel nitrate containing an NSAID and disulfide pharmacophores, a lead compound for the design of agents specifically for colorectal cancer. GT-094 is the first nitrate reported to reduce aberrant crypt foci (by 45%) when administered after carcinogen in the standard azoxymethane rat model of colorectal cancer. Analysis of proximal and distal colon tissue from 8- and 28-week rat/azoxymethane studies showed that GT-094 treatment reduced colon crypt proliferation by 30% to 69%, reduced inducible NO synthase (iNOS) levels by 33% to 67%, reduced poly(ADP-ribose)polymerase-1 expression and cleavage 2- to 4-fold, and elevated levels of p27 in the distal colon 3-fold. Studies in cancer cell cultures recapitulated actions of GT-094: antiproliferative activity and transient G(2)-M phase cell cycle block were measured in Caco-2 cells; apoptotic activity was examined but not observed; anti-inflammatory activity was seen in the inhibition of up-regulation of iNOS and endogenous NO production in lipopolysaccharide (LPS)-induced RAW 264.7 cells. In summary, antiproliferative, anti-inflammatory, and cytoprotective activity observed in vivo and in vitro support GT-094 as a lead compound for the design of NO chimeras for colorectal cancer chemoprevention.

Pharmacokinetics of 2,4-di(alpha-methoxyethyl)deuteroporphyrin-IX (dimehin) and its complex with chitosan in mice with tumors

NASA Astrophysics Data System (ADS)

Ivanov, Andrei V.; Gradyushko, A. T.; Laptev, V. P.; Panferova, N. G.; Varlamov, V. P.; Klyashchitsky, B. A.; Reshetnickov, Andrei V.; Ponomarev, Gelii V.

1996-01-01

The kinetics of photosensitizer distribution and elimination have been studied using fluorescent methods in organs and tumors of A/Snell mice with embriocarcinoma inoculated into their thigh muscles for the porphyrin compound 2,4-di((alpha) -methoxyethyl)deuteroporphyrin-- IX (DMH, `Dimehin') and its complex with polysaccharide chitosan. DMH fluorescence differs in samples of liver and faeces which follows from the spectra comparison. DMH is metabolizable upon passing through liver into a form eliminated by the gastrointestinal tract as our pharmacokinetic data have shown. DMH has been found to be a short-term highly photodynamically efficient photosensitizer judging by combined analysis of our toxicological, pharmacokinetic and photodynamic research data. DMH-chitosan uptake and distribution studies have shown the complex's long-term persistence in blood circulation, high level accumulation in spleen and lungs, whereas there was no complex registered in tumors and other tissues following i.v. administration.

Dietary Pectin Increases Intestinal Crypt Stem Cell Survival following Radiation Injury.

PubMed

Sureban, Sripathi M; May, Randal; Qu, Dongfeng; Chandrakesan, Parthasarathy; Weygant, Nathaniel; Ali, Naushad; Lightfoot, Stan A; Ding, Kai; Umar, Shahid; Schlosser, Michael J; Houchen, Courtney W

2015-01-01

Gastrointestinal (GI) mucosal damage is a devastating adverse effect of radiation therapy. We have recently reported that expression of Dclk1, a Tuft cell and tumor stem cell (TSC) marker, 24h after high dose total-body gamma-IR (TBI) can be used as a surrogate marker for crypt survival. Dietary pectin has been demonstrated to possess chemopreventive properties, whereas its radioprotective property has not been studied. The aim of this study was to determine the effects of dietary pectin on ionizing radiation (IR)-induced intestinal stem cell (ISC) deletion, crypt and overall survival following lethal TBI. C57BL/6 mice received a 6% pectin diet and 0.5% pectin drinking water (pre-IR mice received pectin one week before TBI until death; post-IR mice received pectin after TBI until death). Animals were exposed to TBI (14 Gy) and euthanized at 24 and 84h post-IR to assess ISC deletion and crypt survival respectively. Animals were also subjected to overall survival studies following TBI. In pre-IR treatment group, we observed a three-fold increase in ISC/crypt survival, a two-fold increase in Dclk1+ stem cells, increased overall survival (median 10d vs. 7d), and increased expression of Dclk1, Msi1, Lgr5, Bmi1, and Notch1 (in small intestine) post-TBI in pectin treated mice compared to controls. We also observed increased survival of mice treated with pectin (post-IR) compared to controls. Dietary pectin is a radioprotective agent; prevents IR-induced deletion of potential reserve ISCs; facilitates crypt regeneration; and ultimately promotes overall survival. Given the anti-cancer activity of pectin, our data support a potential role for dietary pectin as an agent that can be administered to patients receiving radiation therapy to protect against radiation-induces mucositis.

Use of the cryptogein gene to stimulate the accumulation of Bacopa saponins in transgenic Bacopa monnieri plants.

PubMed

Majumdar, Sukanya; Garai, Saraswati; Jha, Sumita

2012-10-01

Genetic transformation of the Indian medicinal plant, Bacopa monnieri, using a gene encoding cryptogein, a proteinaceous elicitor, via Ri and Ti plasmids, were established and induced bioproduction of bacopa saponins in crypt-transgenic plants were obtained. Transformed roots obtained with A. rhizogenes strain LBA 9402 crypt on selection medium containing kanamycin (100 mg l(-1)) dedifferentiated forming callus and redifferentiated to roots which, spontaneously showed shoot bud induction. Ri crypt-transformed plants thus obtained showed integration and expression of rol genes as well as crypt gene. Ti crypt-transformed B. monnieri plants were established following transformation with disarmed A. tumefaciens strain harboring crypt. Transgenic plants showed significant enhancement in growth and bacopa saponin content. Bacopasaponin D (1.4-1.69 %) was maximally enhanced in transgenic plants containing crypt. In comparison to Ri-transformed plants, Ri crypt-transformed plants showed significantly (p ≤ 0.05) enhanced accumulation of bacoside A(3), bacopasaponin D, bacopaside II, bacopaside III and bacopaside V. Produced transgenic lines can be used for further research on elicitation in crypt-transgenic plants as well as for large scale production of saponins. Key message The cryptogein gene, which encodes a proteinaceous elicitor is associated with increase in secondary metabolite accumulation-either alone or in addition to the increases associated with transformation by A. rhizogenes.

Distinct cytoprotective roles of pyruvate and ATP by glucose metabolism on epithelial necroptosis and crypt proliferation in ischaemic gut

PubMed Central

Huang, Ching‐Ying; Kuo, Wei‐Ting; Huang, Chung‐Yen; Lee, Tsung‐Chun; Chen, Chin‐Tin; Peng, Wei‐Hao; Lu, Kuo‐Shyan; Yang, Chung‐Yi

2016-01-01

Key points Intestinal ischaemia causes epithelial death and crypt dysfunction, leading to barrier defects and gut bacteria‐derived septic complications.Enteral glucose protects against ischaemic injury; however, the roles played by glucose metabolites such as pyruvate and ATP on epithelial death and crypt dysfunction remain elusive.A novel form of necrotic death that involves the assembly and phosphorylation of receptor interacting protein kinase 1/3 complex was found in ischaemic enterocytes.Pyruvate suppressed epithelial cell death in an ATP‐independent manner and failed to maintain crypt function. Conversely, replenishment of ATP partly restored crypt proliferation but had no effect on epithelial necroptosis in ischaemic gut.Our data argue against the traditional view of ATP as the main cytoprotective factor by glucose metabolism, and indicate a novel anti‐necroptotic role of glycolytic pyruvate under ischaemic stress. Abstract Mesenteric ischaemia/reperfusion induces epithelial death in both forms of apoptosis and necrosis, leading to villus denudation and gut barrier damage. It remains unclear whether programmed cell necrosis [i.e. receptor‐interacting protein kinase (RIP)‐dependent necroptosis] is involved in ischaemic injury. Previous studies have demonstrated that enteral glucose uptake by sodium‐glucose transporter 1 ameliorated ischaemia/reperfusion‐induced epithelial injury, partly via anti‐apoptotic signalling and maintenance of crypt proliferation. Glucose metabolism is generally assumed to be cytoprotective; however, the roles played by glucose metabolites (e.g. pyruvate and ATP) on epithelial cell death and crypt dysfunction remain elusive. The present study aimed to investigate the cytoprotective effects exerted by distinct glycolytic metabolites in ischaemic gut. Wistar rats subjected to mesenteric ischaemia were enterally instilled glucose, pyruvate or liposomal ATP. The results showed that intestinal ischaemia caused RIP1‐dependent epithelial necroptosis and villus destruction accompanied by a reduction in crypt proliferation. Enteral glucose uptake decreased epithelial cell death and increased crypt proliferation, and ameliorated mucosal histological damage. Instillation of cell‐permeable pyruvate suppressed epithelial cell death in an ATP‐independent manner and improved the villus morphology but failed to maintain crypt function. Conversely, the administration of liposomal ATP partly restored crypt proliferation but did not reduce epithelial necroptosis and histopathological injury. Lastly, glucose and pyruvate attenuated mucosal‐to‐serosal macromolecular flux and prevented enteric bacterial translocation upon blood reperfusion. In conclusion, glucose metabolites protect against ischaemic injury through distinct modes and sites, including inhibition of epithelial necroptosis by pyruvate and the promotion of crypt proliferation by ATP. PMID:27121603

Combined changes in Wnt signaling response and contact inhibition induce altered proliferation in radiation-treated intestinal crypts

PubMed Central

Dunn, S.-J.; Osborne, J. M.; Appleton, P. L.; Näthke, I.

2016-01-01

Curative intervention is possible if colorectal cancer is identified early, underscoring the need to detect the earliest stages of malignant transformation. A candidate biomarker is the expanded proliferative zone observed in crypts before adenoma formation, also found in irradiated crypts. However, the underlying driving mechanism for this is not known. Wnt signaling is a key regulator of proliferation, and elevated Wnt signaling is implicated in cancer. Nonetheless, how cells differentiate Wnt signals of varying strengths is not understood. We use computational modeling to compare alternative hypotheses about how Wnt signaling and contact inhibition affect proliferation. Direct comparison of simulations with published experimental data revealed that the model that best reproduces proliferation patterns in normal crypts stipulates that proliferative fate and cell cycle duration are set by the Wnt stimulus experienced at birth. The model also showed that the broadened proliferation zone induced by tumorigenic radiation can be attributed to cells responding to lower Wnt concentrations and dividing at smaller volumes. Application of the model to data from irradiated crypts after an extended recovery period permitted deductions about the extent of the initial insult. Application of computational modeling to experimental data revealed how mechanisms that control cell dynamics are altered at the earliest stages of carcinogenesis. PMID:27053661

Neuroethological validation of an experimental apparatus to evaluate oriented and non-oriented escape behaviours: Comparison between the polygonal arena with a burrow and the circular enclosure of an open-field test.

PubMed

Biagioni, Audrey Francisco; dos Anjos-Garcia, Tayllon; Ullah, Farhad; Fisher, Isaac René; Falconi-Sobrinho, Luiz Luciano; de Freitas, Renato Leonardo; Felippotti, Tatiana Tocchini; Coimbra, Norberto Cysne

2016-02-01

Inhibition of GABAergic neural inputs to dorsal columns of the periaqueductal grey matter (dPAG), posterior (PH) and dorsomedial (DMH) hypothalamic nuclei elicits distinct types of escape behavioural reactions. To differentiate between the variety and intensity of panic-related behaviours, the pattern of defensive behaviours evoked by blockade of GABAA receptors in the DMH, PH and dPAG were compared in a circular open-field test and in a recently designed polygonal arena. In the circular open-field, the defensive behaviours induced by microinjection of bicuculline into DMH and PH were characterised by defensive alertness behaviour and vertical jumps preceded by rearing exploratory behaviour. On the other hand, explosive escape responses interspersed with horizontal jumps and freezing were observed after the blockade of GABAA receptors on dPAG neurons. In the polygonal arena apparatus, the escape response produced by GABAergic inhibition of DMH and PH neurons was directed towards the burrow. In contrast, the blockade of GABAA receptors in dPAG evoked non-oriented escape behaviour characterised by vigorous running and horizontal jumps in the arena. Our findings support the hypothesis that the hypothalamic nuclei organise oriented escape behavioural responses whereas non-oriented escape is elaborated by dPAG neurons. Additionally, the polygonal arena with a burrow made it easy to discriminate and characterise these two different patterns of escape behavioural responses. In this sense, the polygonal arena with a burrow can be considered a good methodological tool to discriminate between these two different patterns of escape behavioural responses and is very useful as a new experimental animal model of panic attacks. Copyright © 2015 Elsevier B.V. All rights reserved.

Chemopreventive effect of different ratios of fish oil and corn oil on prognostic markers, DNA damage and cell cycle in colon carcinogenesis.

PubMed

Sarotra, Pooja; Kansal, Shevali; Sandhir, Rajat; Agnihotri, Navneet

2012-03-01

Fish oil (FO) rich in n-3 polyunsaturated fatty acids (PUFAs) have a protective role in autoimmune disorders, type 2 diabetes, rheumatoid arthritis, and cancer, whereas corn oil (CO) rich in n-6 PUFAs has a proinflammatory and procarcinogenic effect. A balanced n-3/n-6 PUFA ratio in diet rather than absolute intake of either may be responsible for decreasing cancer incidence. This study was designed to evaluate the chemopreventive effect of different ratios of FO and CO on prognostic markers, DNA damage, and cell cycle distribution in colon carcinogenesis. Male Wistar rats were divided into control, N,N'-dimethylhydrazine dihydrochloride (DMH) treated, FO+CO(1 : 1)+DMH, and FO+CO(2.5 : 1)+DMH. All the groups, except control, received a weekly injection of DMH for 4 weeks. The animals were given modified AIN-76A diets and killed either 48 h later (initiation phase) or kept for 16 weeks (postinitiation phase). The animals treated with DMH in both the phases showed an increase in multiple plaque lesions, total sialic acid, lipid associated sialic acid, DNA damage and cell proliferation. However, levels of p53 in the postinitiation and cyclin D1 in both the phases were significantly elevated. FO+CO(2.5 : 1)+DMH treatment in both the phases led to a decrease in multiple plaque lesions, DNA damage, total sialic acid, lipid associated sialic acid as compared with the DMH treated group. There was a G1 arrest with a decrease in p53 and cyclin D1 levels in FO+CO(2.5 : 1) in both the phases whereas treatment with FO+CO(1 : 1)+DMH led to same results in the postinitiation phase only. This study suggests that FO+CO(2.5 : 1) is more effective in chemoprevention of experimental colon carcinogenesis.

Tales from the crypt: a parasitoid manipulates the behaviour of its parasite host

PubMed Central

Liu, Sean M.; Forbes, Andrew A.; Egan, Scott P.

2017-01-01

There are many examples of apparent manipulation of host phenotype by parasites, yet few examples of hypermanipulation—where a phenotype-manipulating parasite is itself manipulated by a parasite. Moreover, few studies confirm manipulation is occurring by quantifying whether the host's changed phenotype increases parasite fitness. Here we describe a novel case of hypermanipulation, in which the crypt gall wasp Bassettia pallida (a phenotypic manipulator of its tree host) is manipulated by the parasitoid crypt-keeper wasp Euderus set, and show that the host's changed behaviour increases parasitoid fitness. Bassettia pallida parasitizes sand live oaks and induces the formation of a ‘crypt’ within developing stems. When parasitized by E. set, B. pallida adults excavate an emergence hole in the crypt wall, plug the hole with their head and die. We show experimentally that this phenomenon benefits E. set, as E. set that need to excavate an emergence hole themselves are about three times more likely to die trapped in the crypt. In addition, we discuss museum and field data to explore the distribution of the crypt-keeping phenomena. PMID:28123089

Polycomb Repressive Complex 2 Enacts Wnt Signaling in Intestinal Homeostasis and Contributes to the Instigation of Stemness in Diseases Entailing Epithelial Hyperplasia or Neoplasia.

PubMed

Oittinen, Mikko; Popp, Alina; Kurppa, Kalle; Lindfors, Katri; Mäki, Markku; Kaikkonen, Minna U; Viiri, Keijo

2017-02-01

Canonical Wnt/β-catenin signaling regulates the homeostasis of intestinal epithelium by controlling the balance between intestinal stem cell self-renewal and differentiation but epigenetic mechanisms enacting the process are not known. We hypothesized that epigenetic regulator, Polycomb Repressive Complex-2 (PRC2), is involved in Wnt-mediated epithelial homeostasis on the crypt-villus axis and aberrancies therein are implicated both in celiac disease and in intestinal malignancies. We found that PRC2 establishes repressive crypt and villus specific trimethylation of histone H3 lysine 27 (H3K27me3) signature on genes responsible for, for example, nutrient transport and cell killing in crypts and, for example, proliferation and differentiation in mature villi, suggesting that PRC2 facilitates the Wnt-governed intestinal homeostasis. When celiac patients are on gluten-containing diet PRC2 is out-of-bounds active and consequently its target genes were found affected in intestinal epithelium. Significant set of effective intestinal PRC2 targets are also differentially expressed in colorectal adenoma and carcinomas. Our results suggest that PRC2 gives rise and maintains polar crypt and villus specific H3K27me3 signatures. As H3K27me3 is a mark enriched in developmentally important genes, identified intestinal PRC2 targets are possibly imperative drivers for enterocyte differentiation and intestinal stem cell maintenance downstream to Wnt-signaling. Our work also elucidates the mechanism sustaining the crypt hyperplasia in celiac disease and suggest that PRC2-dependent fostering of epithelial stemness is a common attribute in intestinal diseases in which epithelial hyperplasia or neoplasia prevails. Finally, this work demonstrates that in intestine PRC2 represses genes having both pro-stemness and pro-differentiation functions, fact need to be considered when designing epigenetic therapies including PRC2 as a drug target. Stem Cells 2017;35:445-457. © 2016 AlphaMed Press.

Novel 1,3,4-thiadiazoles inhibit colorectal cancer via blockade of IL-6/COX-2 mediated JAK2/STAT3 signals as evidenced through data-based mathematical modeling.

PubMed

Raj, Vinit; Bhadauria, Archana S; Singh, Ashok K; Kumar, Umesh; Rai, Amit; Keshari, Amit K; Kumar, Pranesh; Kumar, Dinesh; Maity, Biswanath; Nath, Sneha; Prakash, Anand; Ansari, Kausar M; Jat, Jawahar L; Saha, Sudipta

2018-03-23

We attempted a preclinical study using DMH-induced CRC rat model to evaluate the antitumor potential of our recently synthesized 1,3,4-thiadiazoles. The molecular insights were confirmed through ELISA, qRT-PCR and western blot analyses. The CRC condition was produced in response to COX-2 and IL-6 induced activation of JAK2/STAT3 which, in turn, was due to the enhanced phosphorylation of JAK2 and STAT3. The treatment with 1,3,4-thiadiazole derivatives (VR24 and VR27) caused the significant blockade of this signaling pathway. The behavior of STAT3 populations in response to IL-6 and COX-2 stimulations was further confirmed through data-based mathematical modeling using the quantitative western blot data. Finally, VR24 and VR27 restored the perturbed metabolites associated to DMH-induced CRC as evidenced through 1 H NMR based serum metabolomics. The tumor protecting ability of VR24 and VR27 was found comparable or to some degree better than the marketed chemotherapeutics, 5-flurouracil. Copyright © 2018 Elsevier Ltd. All rights reserved.

The Development of M Cells in Peyer’s Patches Is Restricted to Specialized Dome-Associated Crypts

PubMed Central

Gebert, Andreas; Fassbender, Susanne; Werner, Kerstin; Weissferdt, Annikka

1999-01-01

It is controversial whether the membranous (M) cells of the Peyer’s patches represent a separate cell line or develop from enterocytes under the influence of lymphocytes on the domes. To answer this question, the crypts that produce the dome epithelial cells were studied and the distribution of M cells over the domes was determined in mice. The Ulex europaeus agglutinin was used to detect M cells in mouse Peyer’s patches. Confocal microscopy with lectin-gold labeling on ultrathin sections, scanning electron microscopy, and laminin immuno-histochemistry were combined to characterize the cellular composition and the structure of the dome-associated crypts and the dome epithelium. In addition, the sites of lymphocyte invasion into the dome epithelium were studied after removal of the epithelium using scanning electron microscopy. The domes of Peyer’s patches were supplied with epithelial cells that derived from two types of crypt: specialized dome-associated crypts and ordinary crypts differing not only in shape, size, and cellular composition but also in the presence of M cell precursors. When epithelial cells derived from ordinary crypts entered the domes, they formed converging radial strips devoid of M cells. In contrast to the M cells, the sites where lymphocytes invaded the dome epithelium were not arranged in radial strips, but randomly distributed over the domes. M cell development is restricted to specialized dome-associated crypts. Only dome epithelial cells that derive from these specialized crypts differentiate into M cells. It is concluded that M cells represent a separate cell line that is induced in the dome-associated crypts by still unknown, probably diffusible lymphoid factors. PMID:10329609

Targeting of the MUC1-C Oncoprotein in Colitis-Associated Colorectal Cancer

DTIC Science & Technology

2014-11-01

separated by infiltrates of inflammatory cells and the presence of crypt abscess (lower left panel). With progression to dysplasia, the crypts are...Rajabi, H, et al., MUC1-C oncoprotein induces TCF7L2 activation and promotes cyclin D1 expression in human breast cancer cells. J Biol Chem, 2012

Induction of the tumor-suppressor p16(INK4a) within regenerative epithelial crypts in ulcerative colitis.

PubMed

Furth, Emma E; Gustafson, Karen S; Dai, Charlotte Y; Gibson, Steven L; Menard-Katcher, Paul; Chen, Tina; Koh, Jim; Enders, Greg H

2006-06-01

p16(INK4a) is a major tumor-suppressor protein, but its regulation and settings of fuction remain poorly understood. To explore the notion that p16 is induced in vivo in response to replicative stress, we examined p16 expression in tissues from human ulcerative colitis (UC; n = 25) and normal controls (n = 20). p16 was expressed strongly in UC-associated neoplasms (n = 17), as seen previously in sporadic colonic neoplasms. In non-neoplastic UC epithelium, p16 was expressed in 33% of crypts (the proliferative compartment) compared to < 1% of normal controls. p16 expression did not correlate with degree of inflammation but did correlate with the degree of crypt architecture distortion (P = .002)-a reflection of epithelial regeneration. In coimmunofluorescence studies with Ki67, p16 expression was associated with cell cycle arrest (P < .001). Both UC and normal crypts displayed evidence for the activation of the DNA damage checkpoint pathway, and p16 was induced in primary cultures of normal epithelial cells by ionizing irradiation (IR). However, induction by IR displayed delayed kinetics, implying that p16 is not an immediate target of the checkpoint pathway. These findings support a model in which p16 is induced as an "emergency brake" in cells experiencing sustained replicative stress.

Treadmill running restores MDMA-mediated hyperthermia prevented by inhibition of the dorsomedial hypothalamus

PubMed Central

Zaretsky, Dmitry V; Zaretskaia, Maria V; Durant, Pamela J; Rusyniak, Daniel E

2015-01-01

The contribution of exercise to hyperthermia mediated by MDMA is not known. We recently showed that inhibiting the dorsomedial hypothalamus (DMH) attenuated spontaneous locomotion and hyperthermia and prevented deaths in rats given MDMA in a warm environment. The goal of this study was to confirm that restoring locomotion through a treadmill would reverse these effects thereby confirming that locomotion mediated by the DMH contributes to MDMA-mediated hyperthermia. Rats were randomized to receive bilateral microinjections, into the region of the DMH, of muscimol (80 pmol/100nl) or artificial CSF followed by a systemic dose of either MDMA (7.5 mg/kg, i.v.) or saline. Immediately after the systemic injection, rats were placed on a motorized treadmill maintained at 32°C. Rats were exercised at a fixed speed (10 m/min) until their core temperature reached 41°C. Our results showed that a fixed exercise load abolished the decreases in temperature and mortality, seen previously with inhibition of the DMH in freely moving rats. Therefore, locomotion mediated by neurons in the DMH is critical to the development of hyperthermia from MDMA. PMID:25725382

Effect of complex polyphenols and tannins from red wine (WCPT) on chemically induced oxidative DNA damage in the rat.

PubMed

Casalini, C; Lodovici, M; Briani, C; Paganelli, G; Remy, S; Cheynier, V; Dolara, P

1999-08-01

Flavonoids are polyphenolic antioxidants occurring in vegetables and fruits as well as beverages such as tea and wine which have been thought to influence oxidative damage. We wanted to verify whether a complex mixture of wine tannins (wine complex polyphenols and tannins, WCPT) prevent chemically-induced oxidative DNA damage in vivo. Oxidative DNA damage was evaluated by measuring the ratio of 8-hydroxy-2'-deoxyguanosine (80HdG)/ 2-deoxyguanosine (2dG) x 10(-6) in hydrolyzed DNA using HPLC coupled with electrochemical and UV detectors. We treated rats with WCPT (57 mg/kg p.o.) for 14 d, a dose 10-fold higher than what a moderate wine drinker would be exposed to. WCPT administration significantly reduced the ratio of 80HdG/2dG x 10(-6) in liver DNA obtained from rats treated with 2-nitropropane (2NP) relative to controls administered 2NP only (33. 3 +/- 2.5 vs. 44.9 +/- 3.2 x 10(-6) 2dG; micro +/- SE; p<0.05). On the contrary, pretreatment with WCPT for 10 d did not protect the colon mucosa from oxidative DNA damage induced by 1, 2-dimethylhydrazine (DMH). 2NP and DMH are hepatic and colon carcinogens, respectively, capable of inducing oxidative DNA damage. WCPT have protective action against some types of chemically-induced oxidative DNA damage in vivo.

Azoxymethane protects intestinal stem cells and reduces crypt epithelial mitosis through a COX-1-dependent mechanism.

PubMed

Riehl, Terrence E; George, Robert J; Sturmoski, Mark A; May, Randal; Dieckgraefe, Brian; Anant, Shrikant; Houchen, Courtney W

2006-12-01

Azoxymethane (AOM) is a potent DNA-damaging agent and carcinogen that induces intestinal and colonic tumors in rodents. Evaluation of the stem cell population by colony formation assay reveals that, within 8 h after treatment, AOM (10 mg/kg) elicited a prosurvival response. In wild-type (WT) mice, AOM treatment induced a 2.5-fold increase in intestinal crypt stem cell survival. AOM treatment increased stem cell survival in cyclooxygenase (COX)-2(-/-) but not COX-1(-/-) mice, confirming a role of COX-1 in the AOM-induced increase in stem cell survival. COX-1 mRNA and protein expression as well as COX-1-derived PGE(2) synthesis were increased 8 h after AOM treatment. Immunohistochemical staining of COX-1 demonstrated expression of the enzyme in the crypt epithelial cells, especially in the columnar epithelial cells between the Paneth cells adjacent to the stem cell zone. WT mice receiving AOM exhibited increased intestinal apoptosis and a simultaneous reduction in crypt mitotic figures within 8 h of injection. There were no significant differences in baseline or AOM-induced intestinal epithelial apoptosis between WT and COX-1(-/-) mice, but there was a complete reversal of the AOM-mediated reduction in mitosis in COX-1(-/-) mice. This suggests that COX-1-derived PGE(2) may play a key role in the early phase of intestinal tumorigenesis in response to DNA damage and suggests that COX-1 may be a potential therapeutic target in this model of colon cancer.

Depletion of enteric bacteria diminishes leukocyte infiltration following doxorubicin-induced small intestinal damage in mice.

PubMed

Carr, Jacquelyn S; King, Stephanie; Dekaney, Christopher M

2017-01-01

While enteric bacteria have been shown to play a critical role in other forms of intestinal damage, their role in mediating the response to the chemotherapeutic drug Doxorubicin (Doxo) is unclear. In this study, we used a mouse model of intestinal bacterial depletion to evaluate the role enteric bacteria play in mediating Doxo-induced small intestinal damage and, more specifically, in mediating chemokine expression and leukocyte infiltration following Doxo treatment. An understanding of this pathway may allow for development of intervention strategies to reduce chemotherapy-induced small intestinal damage. Mice were treated with (Abx) or without (NoAbx) oral antibiotics in drinking water for four weeks and then with Doxo. Jejunal tissues were collected at various time points following Doxo treatment and stained and analyzed for apoptosis, crypt damage and restitution, and macrophage and neutrophil number. In addition, RNA expression of inflammatory markers (TNFα, IL1-β, IL-10) and cytokines (CCL2, CC7, KC) was assessed by qRT-PCR. In NoAbx mice Doxo-induced damage was associated with rapid induction of apoptosis in jejunal crypt epithelium and an increase weight loss and crypt loss. In addition, we observed an increase in immune-modulating chemokines CCL2, CCL7 and KC and infiltration of macrophages and neutrophils. In contrast, while still positive for induction of apoptosis following Doxo treatment, Abx mice showed neither the overall weight loss nor crypt loss seen in NoAbx mice nor the increased chemokine expression and leukocyte infiltration. Enteric bacteria play a critical role in Doxo-induced small intestinal damage and are associated with an increase in immune-modulating chemokines and cells. Manipulation of enteric bacteria or the damage pathway may allow for prevention or treatment of chemotherapy-induced small intestinal damage.

Evidence of functional cross talk between the Notch and NF-κB pathways in nonneoplastic hyperproliferating colonic epithelium.

PubMed

Ahmed, Ishfaq; Roy, Badal; Chandrakesan, Parthasarathy; Venugopal, Anand; Xia, Lijun; Jensen, Roy; Anant, Shrikant; Umar, Shahid

2013-02-15

The Notch and NF-κB signaling pathways regulate stem cell function and inflammation in the gut, respectively. We investigate whether a functional cross talk exists between the two pathways during transmissible murine colonic hyperplasia (TMCH) caused by Citrobacter rodentium (CR). During TMCH, NF-κB activity and subunit phosphorylation in colonic crypts of NIH Swiss mice at days 6 and 12 were associated with increases in downstream target CXC chemokine ligand (CXCL)-1/keratinocyte-derived chemokine (KC) expression. Blocking Notch signaling acutely for 5 days with the Notch blocker dibenzazepine (DBZ) failed to inhibit crypt NF-κB activity or CXCL-1/KC expression. Chronic DBZ administration for 10 days, however, blocked Notch and NF-κB signaling in the crypts and abrogated hyperplasia. Intriguingly, chronic Notch inhibition was associated with significant increases in IL-1α, granulocyte colony-stimulating factor, monocyte chemoattractant protein 1, macrophage inflammatory protein 2, and KC in the crypt-denuded lamina propria or whole distal colon, with concomitant increases in myeloperoxidase activity. In core-3(-/-) mice, which are defective in intestinal mucin, DBZ administration replicated the results of NIH Swiss mice; in Apc(Min/+) mice, which are associated with CR-induced elevation of NF-κB-p65(276) expression, DBZ reversed the increase in NF-κB-p65(276), which may have blocked rapid proliferation of the mutated crypts. DBZ further blocked reporter activities involving the NF-κB-luciferase reporter plasmid or the Toll-like receptor 4/NF-κB/SEAPorter HEK-293 reporter cell line, while ectopic expression of Notch-N(ICD) reversed the inhibitory effect. Dietary bael (Aegle marmelos) extract (4%) and curcumin (4%) restored Notch and NF-κB cross talk in NIH Swiss mice, inhibited CR/DBZ-induced apoptosis in the crypts, and promoted crypt regeneration. Thus functional cross talk between the Notch and NF-κB pathways during TMCH regulates hyperplasia and/or inflammation in response to CR infection.

Inhibitory effect of peptide Epitalon on colon carcinogenesis induced by 1,2-dimethylhydrazine in rats.

PubMed

Anisimov, Vladimir N; Khavinson, Vladimir Kh; Popovich, I G; Zabezhinski, Mark A

2002-09-08

The effect of synthetic pineal peptide Epitalon (Ala-Glu-Asp-Gly) on colon carcinogenesis was firstly studied in rats. Eighty 2-month-old outbred male LIO rats were subdivided into four groups and were weekly exposed to five subcutaneous injections of 1,2-dimethylhydrazine (DMH) at a single dose of 21 mg/kg body weight. Additionally, 5 days a week, some of the rats were given subcutaneous injections of saline at a dose of 0.1 ml during the whole experiment (group 1, control) or Epitalon at a single dose of 1 microg during the whole experiment (group 2), Epitalon after termination of carcinogen injections (group 3) or during the period of DMH exposure (group 4). Colon carcinomas developed in 90-100% of DMH-treated rats. The number of total colon tumors per rat was 4.1; 2.7; 3.7; 2.9 in groups 1, 2, 3, 4, respectively (the difference in groups 2 and 4 compared with group 1 is significant). In rats from group 2, colon tumors were smaller than in control animals. In group 2, the incidence, as well the multiplicity of tumors in ascending and descending colon, were significantly decreased in comparison with group 1. In group 4, the mean number of tumors per rat was significantly decreased, too. A trend to decrease the number of tumors in the rectum in rats from groups 2, 3 and 4, treated with Epitalon was found. Epitalon inhibited also the development of tumors in jejunum and ileum. Thus, our results demonstrated an inhibitory effect of Epitalon on chemically induced bowel carcinogenesis in rats.

Decreased Expression of Arginine-Phenylalanine-Amide-Related Peptide-3 Gene in Dorsomedial Hypothalamic Nucleus of Constant Light Exposure Model of Polycystic Ovarian Syndrome

PubMed Central

Shaaban, Zahra; Jafarzadeh Shirazi, Mohammad Reza; Nooranizadeh, Mohammad Hossein; Tamadon, Amin; Rahmanifar, Farhad; Ahmadloo, Somayeh; Ramezani, Amin; Zamiri, Mohammad Javad; Razeghian Jahromi, Iman; Sabet Sarvestani, Fatemeh; Hosseinabadi, Omid Koohi

2018-01-01

Background An abnormality in pulse amplitude and frequency of gonadotropin releasing hormone (GnRH) secretion is the most characteristics of polycystic ovarian syndrome (PCOS). On the other hand, arginine-phenylalanine-amide (RFamide)-related peptide-3 (RFRP3) inhibits the secretion of GnRH in mammalian hypothalamus. The current study performed in order to investigate the expression of RFRP3 mRNA in the dorsomedial hypothalamic nucleus (DMH) after the induction of PCOS in a rat model of constant light exposure, and the possible role of parity on occurrence of PCOS. Materials and Methods In the experimental study, female nulliparous (n=12) and primiparous (n=12) rats were randomly subdivided into control and PCOS subgroups (n=6). PCOS were induced by 90 days exposure to constant light. After 90 days, blood, brain, and ovaries were sampled. Serum levels of follicle stimulating hormone (FSH), luteinizing hormone (LH), and testosterone were evaluated. In addition, six adult female ovariectomized rats as a control of real-time polymerase chain reaction (PCR) tests were prepared and in the DMH of all rats, the relative mRNA expression of RFRP3 was assessed. Results Histological evaluation of ovaries represented the polycystic features. In addition, serum concentrations of testosterone in the PCOS subgroups were more than the controls (P<0.05). Furthermore, the relative expression of RFRP3 mRNA in PCOS subgroups was lower than the controls (P<0.05). Conclusion Constant light model of the PCOS-induced rats decreased the gene expression of RFRP3 in the DMH that suggests the decrease of RFRP3 may reduce its inhibitory effect on GnRH during the PCOS pathogenesis. This effect was stronger in the nulliparous rats than the primiparous. PMID:29334206

High dietary intake of sodium selenite does not affect gene mutation frequency in rat colon and liver.

PubMed

Zeng, Huawei; Uthus, Eric O; Ross, Sharon A; Davis, Cindy D

2009-10-01

Our previous studies have shown that selenium (Se) is protective against dimethylhydrazine (DMH)-induced preneoplastic colon cancer lesions, and protection against DNA damage has been hypothesized to be one mechanism for the anticancer effect of Se. The present study was designed to determine whether dietary selenite affects somatic mutation frequency in vivo. We used the Big Blue transgenic model to evaluate the in vivo mutation frequency of the cII gene in rats fed either a Se-deficient (0 microg Se/g diet) or Se-supplemented diet (0.2 or 2 microg Se/g diet; n = 3 rats/diet in experiment 1 and n = 5 rats/group in experiment 2) and injected with DMH (25 mg/kg body weight, i.p.). There were no significant differences in body weight between the Se-deficient and Se-supplemented (0.2 or 2 microg Se/g diet) rats, but the activities of liver glutathione peroxidase and thioredoxin reductase and concentration of liver Se were significantly lower (p < 0.0001) in Se-deficient rats compared to rats supplemented with Se. We found no effect of dietary Se on liver 8-hydroxy-2'-deoxyguanosine. Gene mutation frequency was significantly lower in liver (p < 0.001) than that of colon regardless of dietary Se. However, there were no differences in gene mutation frequency in DNA from colon mucosa or liver from rats fed the Se-deficient diet compared to those fed the Se-supplemented (0.2 or 2 microg Se/g diet) diet. Although gene mutations have been implicated in the etiology of cancer, our data suggest that decreasing gene mutation is not likely a key mechanism through which dietary selenite exerts its anticancer action against DMH-induced preneoplastic colon cancer lesions in a Big Blue transgenic rat model.

Changes in central sodium and not osmolarity or lactate induce panic-like responses in a model of panic disorder.

PubMed

Molosh, Andre I; Johnson, Philip L; Fitz, Stephanie D; Dimicco, Joseph A; Herman, James P; Shekhar, Anantha

2010-05-01

Panic disorder is a severe anxiety disorder characterized by recurrent panic attacks that can be consistently provoked with intravenous (i.v.) infusions of hypertonic (0.5 M) sodium lactate (NaLac), yet the mechanism/CNS site by which this stimulus triggers panic attacks is unclear. Chronic inhibition of GABAergic synthesis in the dorsomedial hypothalamus/perifornical region (DMH/PeF) of rats induces a vulnerability to panic-like responses after i.v. infusion of 0.5 M NaLac, providing an animal model of panic disorder. Using this panic model, we previously showed that inhibiting the anterior third ventricle region (A3Vr; containing the organum vasculosum lamina terminalis, the median preoptic nucleus, and anteroventral periventricular nucleus) attenuates cardiorespiratory and behavioral responses elicited by i.v. infusions of NaLac. In this study, we show that i.v. infusions of 0.5 M NaLac or sodium chloride, but not iso-osmolar D-mannitol, increased 'anxiety' (decreased social interaction) behaviors, heart rate, and blood pressure responses. Using whole-cell patch-clamp preparations, we also show that bath applications of NaLac (positive control), but not lactic acid (lactate stimulus) or D-mannitol (osmolar stimulus), increases the firing rates of neurons in the A3Vr, which are retrogradely labeled from the DMH/PeF and which are most likely glutamatergic based on a separate study using retrograde tracing from the DMH/PeF in combination with in situ hybridization for vesicular glutamate transporter 2. These data show that hypertonic sodium, but not hyper-osmolarity or changes in lactate, is the key stimulus that provokes panic attacks in panic disorder, and is consistent with human studies.

Duodenal crypt health following exposure to Cr(VI): Micronucleus scoring, γ-H2AX immunostaining, and synchrotron X-ray fluorescence microscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thompson, Chad M.; Wolf, Jeffrey C.; Elbekai, Reem H.

2015-08-01

Lifetime exposure to high concentrations of hexavalent chromium [Cr(VI)] in drinking water results in intestinal damage and an increase in duodenal tumors in B6C3F1 mice. To assess whether these tumors could be the result of a direct mutagenic or genotoxic mode of action, we conducted a GLP-compliant 7-day drinking water study to assess crypt health along the entire length of the duodenum. Mice were exposed to water (vehicle control), 1.4, 21, or 180 ppm Cr(VI) via drinking water for 7 consecutive days. Crypt enterocytes in Swiss roll sections were scored as normal, mitotic, apoptotic, karyorrhectic, or as having micronuclei. Amore » single oral gavage of 50 mg/kg cyclophosphamide served as a positive control for micronucleus induction. Exposure to 21 and 180 ppm Cr(VI) significantly increased the number of crypt enterocytes. Micronuclei and γ-H2AX immunostaining were not elevated in the crypts of Cr(VI)-treated mice. In contrast, treatment with cyclophosphamide significantly increased numbers of crypt micronuclei and qualitatively increased γ-H2AX immunostaining. Synchrotron-based X-ray fluorescence (XRF) microscopy revealed the presence of strong Cr fluorescence in duodenal villi, but negligible Cr fluorescence in the crypt compartment. Together, these data indicate that Cr(VI) does not adversely effect the crypt compartment where intestinal stem cells reside, and provide additional evidence that the mode of action for Cr(VI)-induced intestinal cancer in B6C3F1 mice involves chronic villous wounding resulting in compensatory crypt enterocyte hyperplasia.« less

Novel Regenerative Peptide TP508 Mitigates Radiation-Induced Gastrointestinal Damage By Activating Stem Cells and Preserving Crypt Integrity

PubMed Central

Kantara, Carla; Moya, Stephanie M.; Houchen, Courtney W.; Umar, Shahid; Ullrich, Robert L.; Singh, Pomila; Carney, Darrell H.

2015-01-01

In recent years, increasing threats of radiation exposure and nuclear disasters have become a significant concern for the United States and countries worldwide. Exposure to high doses of radiation triggers a number of potentially lethal effects. Among the most severe is the gastrointestinal (GI) toxicity syndrome caused by the destruction of the intestinal barrier, resulting in bacterial translocation, systemic bacteremia, sepsis and death. The lack of effective radioprotective agents capable of mitigating radiation-induced damage has prompted a search for novel countermeasures that can mitigate the effects of radiation post-exposure, accelerate tissue repair in radiation-exposed individuals, and prevent mortality. We report that a single injection of regenerative peptide TP508 (rusalatide acetate, Chrysalin®) 24h after lethal radiation exposure (9Gy, LD100/15) appears to significantly increase survival and delay mortality by mitigating radiation-induced intestinal and colonic toxicity. TP508 treatment post-exposure prevents the disintegration of gastrointestinal crypts, stimulates the expression of adherens junction protein E-cadherin, activates crypt cell proliferation, and decreases apoptosis. TP508 post-exposure treatment also up-regulates the expression of DCLK1 and LGR5 markers of stem cells that have been shown to be responsible for maintaining and regenerating intestinal crypts. Thus, TP508 appears to mitigate the effects of GI toxicity by activating radioresistant stem cells and increasing the stemness potential of crypts to maintain and restore intestinal integrity. These results suggest that TP508 may be an effective emergency nuclear countermeasure that could be delivered within 24h post-exposure to increase survival and delay mortality, giving victims time to reach clinical sites for advanced medical treatment. PMID:26280221

Induction of the Tumor-Suppressor p16INK4a within Regenerative Epithelial Crypts in Ulcerative Colitis1

PubMed Central

Furth, Emma E; Gustafson, Karen S; Dai, Charlotte Y; Gibson, Steven L; Menard-Katcher, Paul; Chen, Tina; Koh, Jim; Enders, Greg H

2006-01-01

Abstract p16INK4a is a major tumor-suppressor protein, but its regulation and settings of fuction remain poorly understood. To explore the notion that p16 is induced in vivo in response to replicative stress, we examined p16 expression in tissues from human ulcerative colitis (UC; n = 25) and normal controls (n = 20). p16 was expressed strongly in UC-associated neoplasms (n = 17), as seen previously in sporadic colonic neoplasms. In non-neoplastic UC epithelium, p16 was expressed in 33% of crypts (the proliferative compartment) compared to < 1% of normal controls. p16 expression did not correlate with degree of inflammation but did correlate with the degree of crypt architecture distortion (P = .002)—a reflection of epithelial regeneration. In coimmunofluorescence studies with Ki67, p16 expression was associated with cell cycle arrest (P < .001). Both UC and normal crypts displayed evidence for the activation of the DNA damage checkpoint pathway, and p16 was induced in primary cultures of normal epithelial cells by ionizing irradiation (IR). However, induction by IR displayed delayed kinetics, implying that p16 is not an immediate target of the checkpoint pathway. These findings support a model in which p16 is induced as an “emergency brake” in cells experiencing sustained replicative stress. PMID:16820088

Intestinal tuft cells regulate the ATM mediated DNA Damage response via Dclk1 dependent mechanism for crypt restitution following radiation injury.

PubMed

Chandrakesan, Parthasarathy; May, Randal; Weygant, Nathaniel; Qu, Dongfeng; Berry, William L; Sureban, Sripathi M; Ali, Naushad; Rao, Chinthalapally; Huycke, Mark; Bronze, Michael S; Houchen, Courtney W

2016-11-23

Crypt epithelial survival and regeneration after injury require highly coordinated complex interplay between resident stem cells and diverse cell types. The function of Dclk1 expressing tuft cells regulating intestinal epithelial DNA damage response for cell survival/self-renewal after radiation-induced injury is unclear. Intestinal epithelial cells (IECs) were isolated and purified and utilized for experimental analysis. We found that small intestinal crypts of Villin Cre ;Dclk1 f/f mice were hypoplastic and more apoptotic 24 h post-total body irradiation, a time when stem cell survival is p53-independent. Injury-induced ATM mediated DNA damage response, pro-survival genes, stem cell markers, and self-renewal ability for survival and restitution were reduced in the isolated intestinal epithelial cells. An even greater reduction in these signaling pathways was observed 3.5 days post-TBI, when peak crypt regeneration occurs. We found that interaction with Dclk1 is critical for ATM and COX2 activation in response to injury. We determined that Dclk1 expressing tuft cells regulate the whole intestinal epithelial cells following injury through paracrine mechanism. These findings suggest that intestinal tuft cells play an important role in regulating the ATM mediated DNA damage response, for epithelial cell survival/self-renewal via a Dclk1 dependent mechanism, and these processes are indispensable for restitution and function after severe radiation-induced injury.

Protective effect of an herbal preparation (HemoHIM) on radiation-induced intestinal injury in mice.

PubMed

Kim, Sung Ho; Lee, Hae June; Kim, Joong Sun; Moon, Changjong; Kim, Jong Choon; Park, Hae-Ran; Jung, Uhee; Jang, Jong Sik; Jo, Sung Kee

2009-12-01

The protective properties of an herbal preparation (HemoHIM) against intestinal damage were examined by evaluating its effects on jejunal crypt survival, morphological changes, and apoptosis in gamma-irradiated mice. The mice were whole-body irradiated with 12 Gy for the examination of jejunal crypt survival and any morphological changes and with 2 Gy for the detection of apoptosis and Ki-67 labeling. Irradiation was conducted using (60)Co gamma-rays. HemoHIM treatment was administered intraperitonially at a dosage of 50 mg/kg of body weight at 36 and 12 hours pre-irradiation and 30 minutes post-irradiation or orally at a dosage of 250 mg/kg of body weight/day for 7 or 11 days before necropsy. The HemoHIM-treated group displayed a significant increase in survival of jejunal crypts, when compared to the irradiation controls. HemoHIM treatment decreased intestinal morphological changes such as crypt depth, villus height, mucosal length, and basal lamina length of 10 enterocytes after irradiation. Furthermore, the administration of HemoHIM protected intestinal cells from irradiation-induced apoptosis. These results suggested that HemoHIM may be therapeutically useful to reduce intestinal injury following irradiation.

Microinjection of muscimol into the dorsomedial hypothalamus suppresses MDMA-evoked sympathetic and behavioral responses

PubMed Central

Rusyniak, Daniel E.; Zaretskaia, Maria V.; Zaretsky, Dmitry V.; DiMicco, Joseph A.

2008-01-01

When given systemically to rats and humans, the drug of abuse 3–4 methylenedioxymethamphetamine (ecstasy, MDMA) elicits hyperthermia, hyperactivity, tachycardia, and hypertension. Chemically stimulating the dorsomedial hypothalamus (DMH), a brain region known to be involved in thermoregulation and in stress responses, causes similar effects. We therefore tested the hypothesis that neuronal activity in the DMH plays a role in MDMA-evoked sympathetic and behavioral responses by microinjecting artificial CSF or muscimol, a neuronal inhibitor, into the DMH prior to intravenous infusion of saline or MDMA in conscious rats. Core temperature, heart rate, mean arterial pressure and locomotor activity were recorded by telemetry every minute for 120 minutes. In rats previously microinjected with CSF, MDMA elicited significant increases from baseline in core temperature (+1.3 ± 0.3°C), locomotion (+50 ± 6 counts/min), heart rate (+142 ± 16 beats/min), and mean arterial pressure (+26 ±3 mmHg). Microinjecting muscimol into the DMH prior to MDMA prevented increases in core temperature and locomotion and attenuated increases in heart rate and mean arterial pressure. These results indicate that neuronal activity in the DMH is necessary for the sympathetic and behavioral responses evoked by MDMA. PMID:18586013

Treadmill running restores MDMA-mediated hyperthermia prevented by inhibition of the dorsomedial hypothalamus.

PubMed

Zaretsky, Dmitry V; Zaretskaia, Maria V; Durant, Pamela J; Rusyniak, Daniel E

2015-05-22

The contribution of exercise to hyperthermia mediated by MDMA is not known. We recently showed that inhibiting the dorsomedial hypothalamus (DMH) attenuated spontaneous locomotion and hyperthermia and prevented deaths in rats given MDMA in a warm environment. The goal of this study was to confirm that restoring locomotion through a treadmill would reverse these effects thereby confirming that locomotion mediated by the DMH contributes to MDMA-mediated hyperthermia. Rats were randomized to receive bilateral microinjections, into the region of the DMH, of muscimol (80pmol/100nl) or artificial CSF followed by a systemic dose of either MDMA (7.5mg/kg, i.v.) or saline. Immediately after the systemic injection, rats were placed on a motorized treadmill maintained at 32°C. Rats were exercised at a fixed speed (10m/min) until their core temperature reached 41°C. Our results showed that a fixed exercise load abolished the decreases in temperature and mortality, seen previously with inhibition of the DMH in freely moving rats. Therefore, locomotion mediated by neurons in the DMH is critical to the development of hyperthermia from MDMA. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of meat (beef, chicken, and bacon) on rat colon carcinogenesis

PubMed Central

Parnaud, Géraldine; Peiffer, Ginette; Taché, Sylviane; Corpet, Denis E.

1998-01-01

High intake of red meat or processed meat is associated with increased risk of colon cancer. In contrast, consumption of white meat (chicken) is not associated with risk and might even reduce the occurrence of colorectal cancer. We speculated that a diet containing beef or bacon would increase and a diet containing chicken would decrease colon carcinogenesis in rats. One hundred female Fischer 344 rats were given a single injection of azoxymethane (20 mg/kg i.p.), then randomized to 10 different AIN-76-based diets. Five diets were adjusted to 14% fat and 23% protein and five other diets to 28% fat and 40% protein. Fat and protein were supplied by 1) lard and casein, 2) olive oil and casein, 3) beef, 4) chicken with skin, and 5) bacon. Meat diets contained 30% or 60% freeze-dried fried meat. The diets were given ad libitum for 100 days, then colon tumor promotion was assessed by the multiplicity of aberrant crypt foci [number of crypts per aberrant crypt focus (ACF)]. The ACF multiplicity was nearly the same in all groups, except bacon-fed rats, with no effect of fat and protein level or source (p = 0.7 between 8 groups by analysis of variance). In contrast, compared with lard- and casein-fed controls, the ACF multiplicity was reduced by 12% in rats fed a diet with 30% bacon and by 20% in rats fed a diet with 60% bacon (p < 0.001). The water intake was higher in bacon-fed rats than in controls (p < 0.0001). The concentrations of iron and bile acids in fecal water and total fatty acids in feces changed with diet, but there was no correlation between these concentrations and the ACF multiplicity. Thus the hypothesis that colonic iron, bile acids, or total fatty acids can promote colon tumors is not supported by this study. The results suggest that, in rats, beef does not promote the growth of ACF and chicken does not protect against colon carcinogenesis. A bacon-based diet appears to protect against carcinogenesis, perhaps because bacon contains 5% NaCl and increased the rats’ water intake. PMID:10050267

A water-soluble extract from cultured medium of Ganoderma lucidum (Reishi) mycelia attenuates the small intestinal injury induced by anti-cancer drugs

PubMed Central

KASHIMOTO, NAOKI; ISHII, SATOMI; MYOJIN, YUKI; USHIJIMA, MITSUYASU; HAYAMA, MINORU; WATANABE, HIROMITSU

2010-01-01

The present study investigated whether a water-soluble extract from the culture medium of Ganoderma lucidum (Reishi) mycelia (MAK) is able to protect the small intestine against damage induced by anti-cancer drugs. Six-week-old male B6C3F1/Crlj mice were fed a basal diet (MF) alone or with various doses of MAK or Agarics blazei Murrill (AGA) beginning one week before treatment with the anti-cancer drugs. Mice were sacrificed 3.5 days after injection of the anti-cancer drug, the small intestine was removed and tissue specimens were examined for the regeneration of small intestinal crypts. In experiment 1, the number of regenerative crypts after the administration of 5-fluorouracil (5FU) intravenously (250 mg/kg) or intraperitoneally (250 or 500 mg/kg) was compared after treatment with MAK or AGA. MAK protected against 5FU-induced small intestinal injury whereas AGA did not. In experiment 2, we investigated the protective effect of MAK against small intestinal injury induced by the anti-cancer drugs: UFT (tegafur with uracil; 1,000 mg/kg, orally), cisplatin (CDDP; 12.5 and 25 mg/kg, intraperitoneally), cyclophosphamide (CPA; 250 mg/kg, orally) and gefitinib (Iressa; 2,000 and 4,000 mg/kg, orally). UFT and CDDP decreased the number of regenerative crypts, but treatment with MAK attenuated the extent of UFT- or CDDP-induced small intestinal injury. CPA or Iressa plus MAK up-regulated crypt regeneration. The present results indicate that MAK ameliorates the small intestinal injury caused by several anti-cancer drugs, suggesting that MAK is a potential preventive agent against this common adverse effect of chemotherapy. PMID:22966257

Characterisation of colonic dysplasia-like epithelial atypia in murine colitis

PubMed Central

Randall-Demllo, Sarron; Fernando, Ruchira; Brain, Terry; Sohal, Sukhwinder Singh; Cook, Anthony L; Guven, Nuri; Kunde, Dale; Spring, Kevin; Eri, Rajaraman

2016-01-01

AIM To determine if exacerbation of pre-existing chronic colitis in Winnie (Muc2 mutant) mice induces colonic dysplasia. METHODS Winnie mice and C57BL6 as a genotype control, were administered 1% w/v dextran sulphate sodium (DSS) orally, followed by drinking water alone in week-long cycles for a total of three cycles. After the third cycle, mice were killed and colonic tissue collected for histological and immunohistochemical evaluation. Inflammation and severity of dysplasia in the colonic mucosa were assessed in H&E sections of the colon. Epithelial cell proliferation was assessed using Ki67 and aberrant β-catenin signalling assessed with enzyme-based immunohistochemistry. Extracted RNA from colonic segments was used for the analysis of gene expression using real-time quantitative PCR. Finally, the distribution of Cxcl5 was visualised using immunohistochemistry. RESULTS Compared to controls, Winnie mice exposed to three cycles of DSS displayed inflammation mostly confined to the distal-mid colon with extensive mucosal hyperplasia and regenerative atypia resembling epithelial dysplasia. Dysplasia-like changes were observed in 100% of Winnie mice exposed to DSS, with 55% of these animals displaying changes similar to high-grade dysplasia, whereas high-grade changes were absent in wild-type mice. Occasional penetration of the muscularis mucosae by atypical crypts was observed in 27% of Winnie mice after DSS. Atypical crypts however displayed no evidence of oncogenic nuclear β-catenin accumulation, regardless of histological severity. Expression of Cav1, Trp53 was differentially regulated in the distal colon of Winnie relative to wild-type mice. Expression of Myc and Ccl5 was increased by DSS treatment in Winnie only. Furthermore, increased Ccl5 expression correlated with increased complexity in abnormal crypts. While no overall difference in Cxcl5 mucosal expression was observed between treatment groups, epithelial Cxcl5 protein appeared to be diminished in the atypical epithelium. CONCLUSION Alterations to the expression of Cav1, Ccl5, Myc and Trp53 in the chronically inflamed Winnie colon may influence the transition to dysplasia. PMID:27729740

Towards successful Dissemination of Psychological First Aid: a study of provider training preferences.

PubMed

Hambrick, Erin P; Rubens, Sonia L; Vernberg, Eric M; Jacobs, Anne K; Kanine, Rebecca M

2014-04-01

Dissemination of Psychological First Aid (PFA) is challenging considering the complex nature of disaster response and the various disaster mental health (DMH) trainings available. To understand challenges to dissemination in community mental health centers (CMHCs), interviews were conducted with nine DMH providers associated with CMHCs. Consensual qualitative analysis was used to analyze data. Interviews were targeted toward understanding organizational infrastructure, DMH training requirements, and training needs. Results clarified challenges to DMH training in CMHCs and factors that may promote buy-in for trainings. For example, resources are limited and thus allocated for state and federal training requirements. Therefore, including PFA in these requirements could promote adoption. Additionally, a variety of training approaches that differ in content, style, and length would be useful. To conclude, a conceptual model for ways to promote buy-in for the PFA Guide is proposed.

[Glucagon-like peptide 2, a neurotransmitter with a newly discovered role in the regulation of food ingestion].

PubMed

Tang-Christensen, M; Larsen, P J; Thulesen, J; Nielsen, J R; Vrang, N

2001-01-15

We report here that glucagon-like peptide 2(GLP-2) and its receptor constitute a distinct projection system connecting the nucleus of the solitary tract with the dorsomedial hypothalamic nucleus (DMH). The DMH contains a dense plexus of GLP-2 immunoreactive fibres and is the only hypothalamic nucleus expressing GLP-2 receptor mRNA. Consistent with this, central application of GLP-2 activates the expression of neurones solely in the DMH. Furthermore, central administration of GLP-2 causes a dose-related, a pharmacologically and behaviourally specific inhibition of food intake in rats. Surprisingly, the alleged GLP-1 receptor antagonist, Exending (9-39), proved a functional antagonist of centrally applied GLP-2. These data implicate GLP-2 as an important neurotransmitter in the regulation of food intake and likely bodyweight. Our data therefore point to the DMH as a crossroad for endocrine and visceral information affecting feeding behaviour.

Inhibitory effects of astaxanthin on azoxymethane-induced colonic preneoplastic lesions in C57/BL/KsJ-db/db mice.

PubMed

Kochi, Takahiro; Shimizu, Masahito; Sumi, Takafumi; Kubota, Masaya; Shirakami, Yohei; Tanaka, Takuji; Moriwaki, Hisataka

2014-12-17

Obesity and related metabolic abnormalities, including excess oxidative stress and chronic inflammation, are associated with colorectal carcinogenesis. Astaxanthin, a xanthophyll carotenoid found in aquatic animals, is known to possess antioxidant, anti-inflammatory, and antineoplastic properties. The present study examined the effects of astaxanthin on the development of azoxymethane (AOM)-induced colonic premalignant lesions in C57BL/KsJ-db/db (db/db) obese mice. Male db/db mice were administered 4 weekly subcutaneous injections of AOM (15 mg/kg body weight) from 5 weeks of age and subsequently, from 1 week after the last injection of AOM, were fed a diet containing 200 ppm astaxanthin throughout the experiment (8 weeks). The development of colonic premalignant lesions, i.e., aberrant crypt foci and β-catenin accumulated crypts, was significantly inhibited in mice treated with astaxanthin than in mice fed the basal diet. Astaxanthin administration markedly reduced urinary levels of 8-OHdG and serum levels of d-ROMs, which are oxidative stress markers, while increasing the expression of mRNA for the antioxidant enzymes GPx1, SOD1, and CAT in the colonic mucosa of AOM-treated db/db mice. The expression levels of IL-1β, IL-6, F4/80, CCL2, and CXCL2 mRNA in the colonic mucosa of AOM-treated mice were significantly decreased by astaxanthin. Dietary feeding with astaxanthin also resulted in a reduction in the numbers of NF-κB- and PCNA-positive cells that were increased by AOM exposure, in the colonic epithelium. These findings suggest that astaxanthin inhibits the development of colonic premalignant lesions in an obesity-related colorectal carcinogenesis model by reducing oxidative stress, attenuating chronic inflammation, and inhibiting NF-κB activation and cell proliferation in the colonic mucosa. Astaxanthin, therefore, may be a potential candidate as a chemoprevention agent against colorectal carcinogenesis in obese individuals.

Chemopreventive evaluation of a Schiff base derived copper (II) complex against azoxymethane-induced colorectal cancer in rats.

PubMed

Hajrezaie, Maryam; Hassandarvish, Pouya; Moghadamtousi, Soheil Zorofchian; Gwaram, Nura Suleiman; Golbabapour, Shahram; Najihussien, Abdrabuh; Almagrami, Amel Abdullah; Zahedifard, Maryam; Rouhollahi, Elham; Karimian, Hamed; Fani, Somaye; Kamalidehghan, Behnam; Majid, Nazia Abdul; Ali, Hapipah Mohd; Abdulla, Mahmood Ameen

2014-01-01

Based on the potential of Schiff base compounds to act as sources for the development of cancer chemotherapeutic agents, this in vivo study was performed to investigate the inhibitory properties of the synthetic Schiff base compound Cu(BrHAP)2 on colonic aberrant crypt foci (ACF). This study involved five groups of male rats. The negative control group was injected with normal saline once a week for 2 weeks and fed 10% Tween 20 for 10 weeks, the cancer control group was subcutaneously injected with 15 mg/kg azoxymethane once per week for two consecutive weeks, the positive control group was injected with 15 mg/kg azoxymethane once per week for two consecutive weeks and 35 mg/kg 5-fluorouracil (injected intra-peritoneally) for 4 weeks, and the experimental groups were first injected with 15 mg/kg azoxymethane once per week for two consecutive weeks and then fed 2.5 or 5 mg/kg of the Schiff base compound once a day for 10 weeks. Application of the Schiff base compound suppressed total colonic ACF formation by up to 72% to 74% (P<0.05) when compared with the cancer control group. Analysis of colorectal specimens revealed that treatments with the Schiff base compound decreased the mean crypt scores in azoxymethane-treated rats. Significant elevations of superoxide dismutase, glutathione peroxidase and catalase activities and a reduction in the level of malondialdehyde were also observed. Histologically, all treatment groups exhibited significant decreases in dysplasia compared to the cancer control group (P<0.05). Immunohistochemical staining demonstrated down-regulation of the PCNA protein. Comparative western blot analysis revealed that COX-2 and Bcl2 were up-regulated and Bax was down-regulated compared with the AOM control group. The current study demonstrated that the Cu(BrHAP)2 compound has promising chemoprotective activities that are evidenced by significant decreases in the numbers of ACFs in azoxymethane-induced colon cancer.

Chemopreventive Evaluation of a Schiff Base Derived Copper (II) Complex against Azoxymethane-Induced Colorectal Cancer in Rats

PubMed Central

Hajrezaie, Maryam; Hassandarvish, Pouya; Moghadamtousi, Soheil Zorofchian; Gwaram, Nura Suleiman; Golbabapour, Shahram; NajiHussien, Abdrabuh; Almagrami, Amel Abdullah; Zahedifard, Maryam; Rouhollahi, Elham; Karimian, Hamed; Fani, Somaye; Kamalidehghan, Behnam; Majid, Nazia Abdul; Ali, Hapipah Mohd; Abdulla, Mahmood Ameen

2014-01-01

Background Based on the potential of Schiff base compounds to act as sources for the development of cancer chemotherapeutic agents, this in vivo study was performed to investigate the inhibitory properties of the synthetic Schiff base compound Cu(BrHAP)2 on colonic aberrant crypt foci (ACF). Methodology This study involved five groups of male rats. The negative control group was injected with normal saline once a week for 2 weeks and fed 10% Tween 20 for 10 weeks, the cancer control group was subcutaneously injected with 15 mg/kg azoxymethane once per week for two consecutive weeks, the positive control group was injected with 15 mg/kg azoxymethane once per week for two consecutive weeks and 35 mg/kg 5-fluorouracil (injected intra-peritoneally) for 4 weeks, and the experimental groups were first injected with 15 mg/kg azoxymethane once per week for two consecutive weeks and then fed 2.5 or 5 mg/kg of the Schiff base compound once a day for 10 weeks. Application of the Schiff base compound suppressed total colonic ACF formation by up to 72% to 74% (P<0.05) when compared with the cancer control group. Analysis of colorectal specimens revealed that treatments with the Schiff base compound decreased the mean crypt scores in azoxymethane-treated rats. Significant elevations of superoxide dismutase, glutathione peroxidase and catalase activities and a reduction in the level of malondialdehyde were also observed. Histologically, all treatment groups exhibited significant decreases in dysplasia compared to the cancer control group (P<0.05). Immunohistochemical staining demonstrated down-regulation of the PCNA protein. Comparative western blot analysis revealed that COX-2 and Bcl2 were up-regulated and Bax was down-regulated compared with the AOM control group. Conclusion The current study demonstrated that the Cu(BrHAP)2 compound has promising chemoprotective activities that are evidenced by significant decreases in the numbers of ACFs in azoxymethane-induced colon cancer. PMID:24618844

Protective versus promotional effects of white tea and caffeine on PhIP-induced tumorigenesis and β-catenin expression in the rat

PubMed Central

Wang, Rong; Dashwood, W. Mohaiza; Löhr, Christiane V.; Fischer, Kay A.; Pereira, Clifford B.; Louderback, Mandy; Nakagama, Hitoshi; Bailey, George S.; Williams, David E.; Dashwood, Roderick H.

2009-01-01

A 1 year carcinogenicity bioassay was conducted in rats treated with three short cycles of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)/high-fat (HF) diet, followed by 2% white tea (wt/vol), 0.05% epigallocatechin-3-gallate (EGCG) or 0.065% caffeine as sole source of fluid intake. Thirty-two percent of the PhIP/HF controls survived to 1 year, compared with 50, 48.7 and 18.2% in groups given white tea, EGCG and caffeine, respectively. After 1 year, PhIP/HF controls had tumors in the colon, skin, small intestine, Zymbal’s gland, salivary gland and pancreas. For all sites combined, excluding the colon, tumor incidence data were as follows: PhIP/HF 69.5%, PhIP/HF + EGCG 48.7%, PhIP/HF + white tea 46.9% and PhIP/HF + caffeine 13.3%. Unexpectedly, a higher incidence of colon tumors was detected in rats post-treated with white tea (69%) and caffeine (73%) compared with the 42% incidence in PhIP/HF controls. In the colon tumors, β-catenin mutations were detected at a higher frequency after caffeine posttreatment, and there was a shift toward more tumors harboring substitutions of Gly34 with correspondingly high protein and messenger RNA expression seen for both β-catenin and c-Myc. c-Myc expression exhibited concordance with tumor promotion, and there was a concomitant increase in cell proliferation versus apoptosis in colonic crypts. A prior report described suppression of PhIP-induced colonic aberrant crypts by the same test agents, but did not incorporate a HF diet. These findings are discussed in the context of epidemiological data which do not support an adverse effect of tea and coffee on colon tumor outcome—indeed, some such studies suggest a protective role for caffeinated beverages. PMID:18283038

Central pathway for spontaneous and prostaglandin E2-evoked cutaneous vasoconstriction.

PubMed

Rathner, Joseph A; Madden, Christopher J; Morrison, Shaun F

2008-07-01

A reduction of heat loss to the environment through increased cutaneous vasoconstrictor (CVC) sympathetic outflow contributes to elevated body temperature during fever. We determined the role of neurons in the dorsomedial hypothalamus (DMH) in increases in CVC sympathetic tone evoked by PGE2 into the preoptic area (POA) in chloralose/urethane-anesthetized rats. The frequency of axonal action potentials of CVC sympathetic ganglion cells recorded from the surface of the tail artery was increased by 1.8 Hz following nanoinjections of bicuculline (50 pmol) into the DMH. PGE2 nanoinjection into the POA elicited a similar excitation of tail CVC neurons (+2.1 Hz). Subsequent to PGE2 into the POA, muscimol (400 pmol/side) into the DMH did not alter the activity of tail CVC neurons. Inhibition of neurons in the rostral raphé pallidus (rRPa) eliminated the spontaneous discharge of tail CVC neurons but only reduced the PGE2-evoked activity. Residual activity was abolished by subsequent muscimol into the rostral ventrolateral medulla. Transections through the neuraxis caudal to the POA increased the activity of tail CVC neurons, which were sustained through transections caudal to DMH. We conclude that while activation of neurons in the DMH is sufficient to activate tail CVC neurons, it is not necessary for their PGE2-evoked activity. These results support a CVC component of increased core temperature elicited by PGE2 in POA that arises from relief of a tonic inhibition from neurons in POA of CVC sympathetic premotor neurons in rRPa and is dependent on the excitation of CVC premotor neurons from a site caudal to DMH.

Transient, heat-induced thermal resistance in the small intestine of mouse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hume, S.P.; Marigold, J.C.L.

Heat-induced thermal resistance has been investigated in mouse jejunum by assaying crypt survival 24 h after treatment. Hyperthermia was achieved by immersing an exteriorized loop of intestine in a bath of Krebs-Ringer solution. Two approaches have been used. In the first, thermal survival curves were obtained following single hyperthermal treatments at temperatures in the range 42 to 44/sup 0/C. Transient thermal resistance, inducted by a plateau in the crypt survival curve, developed during heating at temperatures around 42.5/sup 0/C after 60 to 80 min. In the second series of experiments, a priming heat treatment (40.0, 41.0, 41.5, or 42.0/sup 0/Cmore » for 60 min) was followed at varying intervals by a test treatment at 43.0/sup 0/C. A transient resistance to the second treatment was induced, the extent and time of development being dependent upon the priming treatment. Crypt survival curves for thermally resistant intestine showed an increase in thermal D/sub 0/ and a decrease in n compared with curves from previously unheated intestine.« less

Human Enteroids as a Model of Upper Small Intestinal Ion Transport Physiology and Pathophysiology.

PubMed

Foulke-Abel, Jennifer; In, Julie; Yin, Jianyi; Zachos, Nicholas C; Kovbasnjuk, Olga; Estes, Mary K; de Jonge, Hugo; Donowitz, Mark

2016-03-01

Human intestinal crypt-derived enteroids are a model of intestinal ion transport that require validation by comparison with cell culture and animal models. We used human small intestinal enteroids to study neutral Na(+) absorption and stimulated fluid and anion secretion under basal and regulated conditions in undifferentiated and differentiated cultures to show their functional relevance to ion transport physiology and pathophysiology. Human intestinal tissue specimens were obtained from an endoscopic biopsy or surgical resections performed at Johns Hopkins Hospital. Crypts were isolated, enteroids were propagated in culture, induced to undergo differentiation, and transduced with lentiviral vectors. Crypt markers, surface cell enzymes, and membrane ion transporters were characterized using quantitative reverse-transcription polymerase chain reaction, immunoblot, or immunofluorescence analyses. We used multiphoton and time-lapse confocal microscopy to monitor intracellular pH and luminal dilatation in enteroids under basal and regulated conditions. Enteroids differentiated upon withdrawal of WNT3A, yielding decreased crypt markers and increased villus-like characteristics. Na(+)/H(+) exchanger 3 activity was similar in undifferentiated and differentiated enteroids, and was affected by known inhibitors, second messengers, and bacterial enterotoxins. Forskolin-induced swelling was completely dependent on cystic fibrosis transmembrane conductance regulator and partially dependent on Na(+)/H(+) exchanger 3 and Na(+)/K(+)/2Cl(-) cotransporter 1 inhibition in undifferentiated and differentiated enteroids. Increases in cyclic adenosine monophosphate with forskolin caused enteroid intracellular acidification in HCO3(-)-free buffer. Cyclic adenosine monophosphate-induced enteroid intracellular pH acidification as part of duodenal HCO3(-) secretion appears to require cystic fibrosis transmembrane conductance regulator and electrogenic Na(+)/HCO3(-) cotransporter 1. Undifferentiated or crypt-like, and differentiated or villus-like, human enteroids represent distinct points along the crypt-villus axis; they can be used to characterize electrolyte transport processes along the vertical axis of the small intestine. The duodenal enteroid model showed that electrogenic Na(+)/HCO3(-) cotransporter 1 might be a target in the intestinal mucosa for treatment of secretory diarrheas. Copyright © 2016 AGA Institute. Published by Elsevier Inc. All rights reserved.

Digital holographic diagnostics of near-injector region

NASA Astrophysics Data System (ADS)

Lee, Jaiho

Study of primary breakup of liquid jets is important because it is motivated by the application to gas turbine fuel injectors, diesel fuel injectors, industrial cleaning and washing machine, medical spray, and inkjet printers, among others. When it comes to good injectors, a liquid jet has to be disintegrated into a fine spray near injector region during primary breakup. However the dense spray region near the injectors is optically obscure for Phase Doppler Interferometer like Phase Doppler Particle Analyzers (PDPA). Holography can provide three dimensional image of the dense spray and eliminate the problem of the small depth of focus associated with shadowgraphs. Traditional film-based holographic technique has long been used for three dimensional measurements in particle fields, but it is time consuming, expensive, chemically hazardous. With the development of the CCD sensor, holograms were recorded and reconstructed digitally. Digital microscopic holography (DMH) is similar to digital inline holography (DIH) except that no lens is used to collimate the object beam. The laser beams are expanded with an objective lens and a spatial filter. This eliminates two lenses from the typical optical path used for in-line holography, which results in a much cleaner hologram recording. The DMH was used for drop size and velocity measurements of the breakup of aerated liquid jets because it is unaffected by the non-spherical droplets that are encountered very close to the injector exit, which would cause problems for techniques such as Phase Doppler Particle Analyzer, otherwise. Large field of view was obtained by patching several high resolution holograms. Droplet velocities in three dimensions were measured by tracking their displacements in the streamwise and cross-stream direction and by tracking the change in the plane of focus in the spanwise direction. The uncertainty in spanwise droplet location and velocity measurements using single view DMH was large at least 33%. This large uncertainty in the spanwise direction, however, can be reduced to 2% by employing double view DMH. Double view DMH successfully tracked the three dimensional bending trajectories of polymer jets during electrospinning. The uncertainty in the spatial growth measurements of the bending instability was reduced using orthogonal double view DMH. Moreover, a commercial grade CCD was successfully used for single- and double-pulsed DMH of micro liquid jet breakup. Using a commercial grade CCD for the DMH, the cost of CCD sensor needed for recording holograms can be reduced.

Colon cancer cells adopt an invasive phenotype without mesenchymal transition in 3-D but not 2-D culture upon combined stimulation with EGF and crypt growth factors.

PubMed

Ludwig, Kirsten; Tse, Edison S; Wang, Jean Yj

2013-05-02

The intestinal crypt homeostasis is maintained by a combination of growth factors including Wnt, R-Spondin1, Noggin and the epidermal growth factor (EGF). In human colorectal cancer, the Wnt pathway is constitutively activated through genetic and epigenetic alterations in as many as 11 genes encoding components of this crypt stem-cell maintenance mechanism. Although the proliferation of colon cancer cells does not require Wnt, it is possible that colon cancer cells can still respond to the crypt growth factors in the colonic microenvironment. A number of studies have shown that epithelial cells behave differently in 3-D versus 2-D cultures. Because the 3-D conditions more closely mimic the in vivo environment, we examined the effects of Wnt and other crypt growth factors on colon cancer cell growth in 3-D culture. Colon cancer cells were grown in 3-D matrigel supplemented with different combinations of crypt growth factors and colonies were examined for morphology and pathways. When colon cancer cells were cultured in 3-D with EGF, they grew as round spheroid colonies. However, colon cancer cells also grew as flat, disc-like colonies when cultured with EGF plus Wnt, R-Spondin1 and Noggin. Disc colonies were found to have comparable levels of E-cadherin as the spheroid colonies, but showed decreased E-cadherin at the cell-matrix contact sites. Disc colonies also elaborated F-actin rich protrusions (FRP) at the cell-matrix edge, reminiscent of an invasive phenotype but without the expression of vimentin. These E-cadherin and F-actin alterations were not induced by the four growth factors in 2-D culture. Formation of the disc colonies was inhibited by the knockdown of β-catenin and by protein kinase inhibitors such as gefitinib, imatinib and MK-2206. Furthermore, withdrawal of the crypt growth factors was able to revert the disc colonies to spheroid growth, showing that the invasive phenotype was reversible dependent on the availability of growth factors. These findings show that colon cancer cells remain responsive to the growth factors in the crypt microenvironment and can be induced to undergo morphological transformation in the more physiologically relevant 3-D culture.

Evaluation of the structural, electronic, topological and vibrational properties of N-(3,4-dimethoxybenzyl)-hexadecanamide isolated from Maca (Lepidium meyenii) using different spectroscopic techniques

NASA Astrophysics Data System (ADS)

Chain, Fernando; Iramain, Maximiliano Alberto; Grau, Alfredo; Catalán, César A. N.; Brandán, Silvia Antonia

2017-01-01

N-(3,4-dimethoxybenzyl)-hexadecanamide (DMH) was characterized by using Fourier Transform infrared (FT-IR) and Raman (FT-Raman), Ultraviolet- Visible (UV-Visible) and Hydrogen and Carbon Nuclear Magnetic Resonance (1H and 13C NMR) spectroscopies. The structural, electronic, topological and vibrational properties were evaluated in gas phase and in n-hexane employing ONIOM and self-consistent force field (SCRF) calculations. The atomic charges, molecular electrostatic potentials, stabilization energies and topological properties of DMH were analyzed and compared with those calculated for N-(3,4-dimethoxybenzyl)-acetamide (DMA) in order to evaluate the effect of the side chain on the properties of DMH. The reactivity and behavior of this alkamide were predicted by using the gap energies and some descriptors. Force fields and the corresponding force constants were reported for DMA only in gas phase and n-hexane due to the high number of vibration normal modes showed by DMH, while the complete vibrational assignments are presented for DMA and both forms of DMH. The comparisons between the experimental FTIR, FT-Raman, UV-Visible and 1H and 13C NMR spectra with the corresponding theoretical ones showed a reasonable concordance.

Prolonged consumption of soy or fish-oil-enriched diets differentially affects the pattern of hypothalamic neuronal activation induced by refeeding in rats.

PubMed

Watanabe, Regina L H; Andrade, Iracema S; Zemdegs, Juliane C S; Albuquerque, Kelse T; Nascimento, Claudia M O; Oyama, Lila M; Carmo, Maria G T; Nogueira, Maria I; Ribeiro, Eliane B

2009-12-01

We used c-Fos immunoreactivity to estimate neuronal activation in hypothalamic feeding-regulatory areas of 3-month-old rats fed control or oil-enriched diets (soy or fish) since weaning. While no diet effect was observed in c-Fos immunoreactivity of 24-h fasted animals, the acute response to refeeding was modified by both hyperlipidic diets but with different patterns. Upon refeeding, control-diet rats had significantly increased c-Fos immunoreactivity only in the paraventricular hypothalamic nucleus (PVH, 142%). In soy-diet rats, refeeding with the soy diet increased c-Fos immunoreactivity in dorsomedial hypothalamic nucleus (DMH, 271%) and lateral hypothalamic area (LH, 303%). Refeeding fish-diet rats with the fish diet increased c-Fos immunoreactivity in PVH (161%), DMH (177%), VMH (81%), and ARC (127%). Compared to the fish-diet, c-Fos immunoreactivity was increased in LH by the soy-diet while it was decreased in ventromedial hypothalamic nucleus (VMH) and arcuate hypothalamic nucleus (ARC). Based on the known roles of the activated nuclei, it is suggested that, unlike the fish-diet, the soy-diet induced a potentially obesogenic profile, with high LH and low VMH/PVH activation after refeeding.

GABA receptors in the region of the dorsomedial hypothalamus of rats regulate anxiety in the elevated plus-maze test. II. Physiological measures.

PubMed

Shekhar, A; Sims, L S; Bowsher, R R

1993-11-05

In the previous report, we had shown that blockade and enhancement of GABAA receptors in the DMH of rats increased or decreased the level of anxiety, respectively, as measured by the elevated plus-maze test. The present study was conducted to assess the effects of enhancing GABAA neurotransmission in the DMH of rats on the physiological concomitants of anxiety such as increases in heart rate (HR), blood pressure (BP) and plasma norepinephrine (NE) levels while the animals were placed on the elevated plus-maze. Male Sprague-Dawley rats were equipped with arterial and venous catheters and stereotaxically implanted with microinjection cannulae in the cardiostimulatory region of the DMH where injection of bicuculline methiodide (BMI) elicited increases in heart rate under anesthesia. After recovery, rats were injected with either saline or the GABAA agonist muscimol and their HR, BP and plasma NE responses were measured when confined in the open or the closed arm of the elevated plus-maze. Injection of muscimol into the DMH reduced the increases seen in HR, BP and plasma NE when the rats were confined to either the closed or the open arms in addition to decreasing 'anxiety' in the plus-maze. Injection of muscimol into the areas of the hypothalamus surrounding the DMH did not significantly affect the changes in HR, BP and plasma NE in the plus-maze. Blocking the changes in HR and BP elicited by microinjecting GABAergic drugs into the DMH of rats, with systemic injections of a combination of atropine and the beta-blocker atenolol, did not block the behavioral effects of the GABAergic drugs in the plus-maze test.

The influence of arachidonic acid metabolites on cell division in the intestinal epithelium and in colonic tumors.

PubMed

Petry, F M; Tutton, P J; Barkla, D H

1984-09-01

Various metabolites of arachidonic acid are now known to influence cell division. In this paper the effects on cell proliferation of arachidonic acid, some inhibitors of arachidonic acid metabolism and some analogs of arachidonic acid metabolites is described. The epithelial cell proliferation rate in the jejunum, in the descending colon and in dimethylhydrazine-induced tumors of rat colon was measured using a stathmokinetic technique. Administration of arachidonic acid resulted in retardation of cell proliferation in each of the tissues examined. A cyclooxygenase inhibitor (Flurbiprofen) prevented this effect of arachidonic acid in the jejunal crypts and in colonic tumors, but not in colonic crypts. In contrast, inhibitors of both cyclooxygenase and lipoxygenase (Benoxaprofen and BW755c) prevented the effect of arachidonic acid in the colonic crypts and reduced its effect on colonic tumours but did not alter its effect on the jejunum. An inhibitor of thromoboxane A2 synthetase (U51,605) was also able to prevent the inhibitory effect of arachidonic acid on colonic tumors. Treatment with 16,16-dimethyl PGE2 inhibited cell proliferation in jejunal crypts and in colonic tumors, as did a thromboxane A2 mimicking agent, U46619. Nafazatrom, an agent that stimulates prostacyclin synthesis and inhibits lypoxygenase, promoted cell proliferation in the jejunal crypts and colonic crypts, but inhibited cell proliferation in colonic tumours.

Supplementation with branched-chain amino acids inhibits azoxymethane-induced colonic preneoplastic lesions in male C57BL/KsJ-db/db mice.

PubMed

Shimizu, Masahito; Shirakami, Yohei; Iwasa, Junpei; Shiraki, Makoto; Yasuda, Yoichi; Hata, Kazuya; Hirose, Yoshinobu; Tsurumi, Hisashi; Tanaka, Takuji; Moriwaki, Hisataka

2009-05-01

Obesity and related metabolic abnormalities, including insulin resistance and activation of the insulin-like growth factor (IGF)/IGF-I receptor (IGF-IR) axis, are risk factors for colon cancer. Supplementation with branched-chain amino acids (BCAA) reduces the risk of liver cancer in cirrhotic patients who are obese, and this has been associated with an improvement of insulin resistance. The present study examined the effects of BCAA on the development of azoxymethane (AOM)-initiated colonic premalignant lesions in C57BL/KsJ-db/db (db/db) mice that were obese and had hyperinsulinemia. Male db/db mice were given 4 weekly s.c. injections of AOM (15 mg/kg of body weight) and then they were fed a diet containing 3.0% BCAA or casein, a nitrogenc content-matched control diet, for 7 weeks. Feeding with BCAA caused a significant reduction in the number of total aberrant crypt foci and beta-catenin accumulated crypts, both of which are premalignant lesions of the colon, compared with the control diet-fed groups. BCAA supplementation caused a marked decrease in the expression of IGF-IR, the phosphorylated form of IGF-IR, phosphorylated glycogen synthase kinase 3beta, phosphorylated Akt, and cyclooxygenase-2 proteins on the colonic mucosa of AOM-treated mice. The serum levels of insulin, IGF-I, IGF-II, triglyceride, total cholesterol, and leptin were also decreased by supplementation with BCAA. BCAA supplementation in diet improves insulin resistance and inhibits the activation of the IGF/IGF-IR axis, thereby preventing the development of colonic premalignancies in an obesity-related colon cancer model that was also associated with hyperlipidemia and hyperinsulinemia. BCAA, therefore, may be a useful chemoprevention modality for colon cancer in obese people.

Different Populations of Prostaglandin EP3 Receptor-Expressing Preoptic Neurons Project to Two Fever-Mediating Sympathoexcitatory Brain Regions

PubMed Central

Nakamura, Y.; Nakamura, K.; Morrison, S. F.

2010-01-01

The central mechanism of fever induction is triggered by an action of prostaglandin E2 (PGE2) on neurons in the preoptic area (POA) through the EP3 subtype of prostaglandin E receptor. EP3 receptor (EP3R)-expressing POA neurons project directly to the dorsomedial hypothalamus (DMH) and to the rostral raphe pallidus nucleus (rRPa), key sites for the control of thermoregulatory effectors. Based on physiological findings, we hypothesize that the febrile responses in brown adipose tissue (BAT) and those in cutaneous vasoconstrictors are controlled independently by separate neuronal pathways: PGE2 pyrogenic signaling is transmitted from EP3R-expressing POA neurons via a projection to the DMH to activate BAT thermogenesis and via another projection to the rRPa to increase cutaneous vasoconstriction. In this case, DMH-projecting and rRPa-projecting neurons would constitute segregated populations within the EP3R-expressing neuronal group in the POA. Here, we sought direct anatomical evidence to test this hypothesis with a double-tracing experiment in which two types of the retrograde tracer, cholera toxin b-subunit (CTb), conjugated with different fluorophores were injected into the DMH and the rRPa of rats and the resulting retrogradely labeled populations of EP3R-immunoreactive neurons in the POA were identified with confocal microscopy. We found substantial numbers of EP3R-immunoreactive neurons in both the DMH-projecting and the rRPa-projecting populations. However, very few EP3R-immunoreactive POA neurons were labeled with both the CTb from the DMH and that from the rRPa, although a substantial number of neurons that were not immunoreactive for EP3R were double-labeled with both CTbs. The paucity of the EP3R-expressing neurons that send collaterals to both the DMH and the rRPa suggests that pyrogenic signals are sent independently to these caudal brain regions from the POA and that such pyrogenic outputs from the POA reflect different control mechanisms for BAT thermogenesis and for cutaneous vasoconstriction by distinct sets of POA neurons. PMID:19327390

Glutamate receptors of the A5 region modulate cardiovascular responses evoked from the dorsomedial hypothalamic nucleus and perifornical area.

PubMed

López-González, M V; Díaz-Casares, A; González-García, M; Peinado-Aragonés, C A; Barbancho, M A; Carrillo de Albornoz, M; Dawid-Milner, M S

2018-05-01

To assess the possible function of glutamate in the interaction between the dorsomedial hypothalamic nucleus-perifornical area (DMH-PeF) and the A5 pontine region (A5), cardiovascular and respiratory changes were studied in response to electrical stimulation of the DMH-PeF (1 ms pulses, 30-50 μA given at 100 Hz for 5 s) before and after the microinjection of kynurenic acid (non-specific glutamate receptor antagonist; 50 nl, 5 nmol), MK-801 (NMDA receptor antagonist; 50 nl, 50 nmol), CNQX (non-NMDA receptor antagonist; 50 nl, 50 nmol) or MCPG (metabotropic glutamate receptor antagonist; 50 nl, 5 nmol) within the A5 region. DMH-PeF electrical stimulation elicited a pressor (p < 0.001) and tachycardic response (p < 0.001) which was accompanied by an inspiratory facilitation characterised by an increase in respiratory rate (p < 0.001) due to a decrease in expiratory time (p < 0.01). Kynurenic acid within the A5 region decreased the tachycardia (p < 0.001) and the intensity of the blood pressure response (p < 0.001) to DMH-PeF stimulation. After the microinjection of MK-801 and CNQX into the A5 region, the magnitude of the tachycardia and the pressor response were decreased (p < 0.05 and p < 0.01; p < 0.001 and p < 0.05, respectively). After MCPG microinjection into the A5 region, a decrease in the tachycardia (p < 0.001) with no changes in the pressor response was observed during DMH-PeF stimulation. The respiratory response elicited by DMH-PeF stimulation was not changed after the microinjection of kynurenic acid, MK-801, CNQX or MCPG within the A5 region. These results suggest that A5 region glutamate receptors play a role in the cardiovascular response elicited from the DMH-PeF. The possible mechanisms involved in these interactions are discussed.

User’s Manual for Strategic Satellite System Terminal Segment Life Cycle Cost Model. Volume 1

DTIC Science & Technology

1981-03-01

the depot pipeline, given by: NFD(I) = EFAIL (I,NS)*TNB(NS) NS *1 [LRU(I) + RTS(NHI(1))]*NRTS(I)*DRCT(LO(NS)) + NRTS(NHI(i))*(l - COND(I))*DADI where... EFAIL (I,NS)*TNB(NS)* [(LRU(I) + RTS(NHI(I)))*NRTS(I) NS + NRTS(NHI(I))*(l-COND(I))] *DMH(I)*DMF where DMH(I) = averaRP marnours to perform depot...XJC - RSCA(I) + 12*PIUP* EFAIL (I,NS)*TNB(NS)* NS {(LRUCI)+RTS(NHI(I)))* (CR(I)*BIIH(I)*BMF*BLR + CN(I)*(DMH(I)*DMF*DLR + 2*CPPD(LOCNS))*WT(I)) + CC

Smad3 contributes to positioning of proliferating cells in colonic crypts by inducing EphB receptor protein expression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Furukawa, Kiyoshi; Sato, Toru; Katsuno, Tatsuro, E-mail: katsuno@faculty.chiba-u.jp

2011-02-25

Research highlights: {yields} Smad3{sup -/-} mice showed an increased number of proliferating epithelial cells in colonic crypts. {yields} Proliferating epithelial cells showed activated Wnt/{beta}-catenin pathway. {yields} Smad3{sup -/-} mice also showed intermingling of proliferating cells with differentiated cells. {yields} Loss of EphB receptor expression was observed in the colonic crypts of Smad3{sup -/-} mice. {yields} Loss of EphB receptor expression is likely responsible for cell intermingling. -- Abstract: Deficiency of Smad3, an intracellular mediator of TGF-{beta}, was shown to significantly accelerate re-epithelialization of the colonic mucosa. This study was performed to investigate the molecular mechanisms by which Smad3 controls colonicmore » epithelial cell proliferation and crypt formation. Smad3{sup ex8/ex8} C57BL/6 mice were used in this study and wild-type littermates served as controls. The number of proliferating cells in the isolated colonic epithelium of Smad3{sup -/-} mice was significantly increased compared to that in wild-type littermates. Protein levels of the cell cycle inhibitors p21 and p27 were significantly decreased, while that of c-Myc was increased in the isolated colonic epithelium from Smad3{sup -/-} mice. In the colonic tissue of wild-type mice, cell proliferation was restricted to the bottom of the crypts in accordance with nuclear {beta}-catenin staining, whereas proliferating cells were located throughout the crypts in Smad3{sup -/-} mice in accordance with nuclear {beta}-catenin staining, suggesting that Smad3 is essential for locating proliferating cells at the bottom of the colonic crypts. Notably, in Smad3{sup -/-} mice, there was loss of EphB2 and EphB3 receptor protein expression, critical regulators of proliferating cell positioning, while EphB receptor protein expression was confirmed at the bottom of the colonic crypts in wild-type mice. These observations indicated that disturbance of the EphB/ephrin B system brings about mispositioning of proliferating cells in the colonic crypts of Smad3{sup -/-} mice. In conclusion, Smad3 is essential for controlling number and positioning of proliferating cells in the colonic crypts and contributes to formation of a 'proliferative zone' at the bottom of colonic crypts in the normal colon.« less

Oleuropein Prevents Azoxymethane-Induced Colon Crypt Dysplasia and Leukocytes DNA Damage in A/J Mice.

PubMed

Sepporta, Maria Vittoria; Fuccelli, Raffaela; Rosignoli, Patrizia; Ricci, Giovanni; Servili, Maurizio; Fabiani, Roberto

2016-08-19

Previous studies have shown that the precursor of olive oil secoiridoids, Oleuropein (OL) has several in vitro chemopreventive properties. OL inhibits proliferation and induces apoptosis in breast, thyroid, prostate, and colorectal cancer (CRC) cells. Much less is known about the effects of OL on animal models of carcinogenesis. In this study, we investigated the ability of OL to prevent the azoxymethane (AOM)-induced colon cancer upset and DNA damage in mice. Animals, fed with a basal diet either enriched or not with OL (125 mg/kg), were injected with AOM (10 mg/kg, once a week for 6 weeks) and sacrificed after either 7 weeks for histological analysis of colon crypt dysplasia and evaluation of DNA damage in leukocytes or 17 weeks for counting the macroscopically observable colon tumors. An OL-enriched diet prevented the AOM-induced preneoplastic lesions in different colon segments, reducing the severity of crypt dysplasia and DNA damage in peripheral leukocytes. In addition, OL significantly reduced the AOM-induced tumor incidence from 57% to 14% (P < .05, chi-square test) in the medial colon segment. This study shows that OL is able to prevent CRC and DNA damage in mice treated with the carcinogen AOM. These results stimulate further human cancer prevention studies with OL-enriched food supplements that are actually available on the market.

μ-Opioid and 5-HT1A receptors in the dorsomedial hypothalamus interact for the regulation of panic-related defensive responses.

PubMed

Roncon, Camila Marroni; Yamashita, Paula Shimene de Melo; Frias, Alana Tercino; Audi, Elisabeth Aparecida; Graeff, Frederico Guilherme; Coimbra, Norberto Cysne; Zangrossi, Helio

2017-06-01

The dorsomedial hypothalamus (DMH) and the dorsal periaqueductal gray (DPAG) have been implicated in the genesis and regulation of panic-related defensive behaviors, such as escape. Previous results point to an interaction between serotonergic and opioidergic systems within the DPAG to inhibit escape, involving µ-opioid and 5-HT1A receptors (5-HT1AR). In the present study we explore this interaction in the DMH, using escape elicited by electrical stimulation of this area as a panic attack index. The obtained results show that intra-DMH administration of the non-selective opioid receptor antagonist naloxone (0.5 nmol) prevented the panicolytic-like effect of a local injection of serotonin (20 nmol). Pretreatment with the selective μ-opioid receptor (MOR) antagonist CTOP (1 nmol) blocked the panicolytic-like effect of the 5-HT1AR agonist 8-OHDPAT (8 nmol). Intra-DMH injection of the selective MOR agonist DAMGO (0.3 nmol) also inhibited escape behavior, and a previous injection of the 5-HT1AR antagonist WAY-100635 (0.37 nmol) counteracted this panicolytic-like effect. These results offer the first evidence that serotonergic and opioidergic systems work together within the DMH to inhibit panic-like behavior through an interaction between µ-opioid and 5-HT1A receptors, as previously described in the DPAG.

Normal Bone Mineral Density Associates with Duodenal Mucosa Healing in Adult Patients with Celiac Disease on a Gluten-Free Diet.

PubMed

Larussa, Tiziana; Suraci, Evelina; Imeneo, Maria; Marasco, Raffaella; Luzza, Francesco

2017-01-31

Impairment of bone mineral density (BMD) is frequent in celiac disease (CD) patients on a gluten-free diet (GFD). The normalization of intestinal mucosa is still difficult to predict. We aim to investigate the relationship between BMD and duodenal mucosa healing (DMH) in CD patients on a GFD. Sixty-four consecutive CD patients on a GFD were recruited. After a median period of a 6-year GFD (range 2-33 years), patients underwent repeat duodenal biopsy and dual-energy X-ray absorptiometry (DXA) scan. Twenty-four patients (38%) displayed normal and 40 (62%) low BMD, 47 (73%) DMH, and 17 (27%) duodenal mucosa lesions. All patients but one with normal BMD (23 of 24, 96%) showed DMH, while, among those with low BMD, 24 (60%) did and 16 (40%) did not. At multivariate analysis, being older (odds ratio (OR) 1.1, 95% confidence interval (CI) 1.03-1.18) and having diagnosis at an older age (OR 1.09, 95% CI 1.03-1.16) were associated with low BMD; in turn, having normal BMD was the only variable independently associated with DMH (OR 17.5, 95% CI 1.6-192). In older CD patients and with late onset disease, BMD recovery is not guaranteed, despite a GFD. A normal DXA scan identified CD patients with DMH; thus, it is a potential tool in planning endoscopic resampling.

The influence of serotonin on the mitotic rate in the colonic crypt epithelium and in colonic adenocarcinoma in rats.

PubMed

Tutton, P J; Barkla, D H

1978-01-01

1. The mitotic rate in the crypts of Lieberkühn of the descending colon and in dimethylhydrazine-induced adenocarcinomata of the descending colon of rat was measured using a stathmokinetic technique. 2. Intraperitoneal injection of a small dose (10 microgram/kg) of serotonin resulted in an increase in the tumour cell mitotic rate. 3. Blockade of serotonin receptors by 2-bromolysergic acid diethylamide and depletion of tissue serotonin levels following injection of DL-6-fluorotryptophan both result in a decrease in the tumour cell mitotic rate. 4. Treatment with serotonin, 2-bromolysergic acid diethylamide and DL-6-fluorotryptophan were all without effect on the colonic crypt cell mitotic rate.

Role of hindbrain adenosine 5'-monophosphate-activated protein kinase (AMPK) in hypothalamic AMPK and metabolic neuropeptide adaptation to recurring insulin-induced hypoglycemia in the male rat.

PubMed

Mandal, Santosh K; Shrestha, Prem K; Alenazi, Fahaad S H; Shakya, Manita; Alhamami, Hussain; Briski, Karen P

2017-12-01

Glucose counter-regulatory dysfunction correlates with impaired activation of the hypothalamic metabolic sensor adenosine 5'-monophosphate-activated protein kinase (AMPK). Hypothalamic AMPK is controlled by hindbrain energy status; we examined here whether hindbrain AMPK regulates hypothalamic AMPK and metabolic neurotransmitter maladaptation to recurring insulin-induced hypoglycemia (RIIH). Brain tissue was harvested after single versus serial insulin (I) dosing for Western blot analysis of AMPK, phospho-AMPK (pAMPK), and relevant biosynthetic enzyme/neuropeptide expression in micro-punch dissected arcuate (ARH), ventromedial (VMH), dorsomedial (DMH) nuclei and lateral hypothalamic area (LHA) tissue. The AMPK inhibitor compound c (Cc) or vehicle was administered to the caudal fourth ventricle ahead of antecedent I injections. RIIH caused site-specific elevation (ARH, VMH, LHA) or reduction (DMH) of total AMPK protein versus acute hypoglycemia; Cc respectively exacerbated or attenuated this response in the ARH and VMH. Hindbrain AMPK correspondingly inhibited or stimulated LHA and DMH pAMPK expression during RIIH. RIIH elicited Cc-reversible augmentation of VMH glutamate decarboxylase profiles, but stimulated (ARH pro-opiomelanocortin; LHA orexin-A) or decreased (VMH nitric oxide synthase) other metabolic neurotransmitters without hindbrain sensor involvement. Results demonstrate acclimated up-regulation of total AMPK protein expression in multiple hypothalamic loci during RIIH, and document hindbrain sensor contribution to amplification of this protein profile in the VMH. Concurrent lack of net change in ARH and VMH tissue pAMPK implies adaptive reductions in local sensor activity, which may/may not reflect positive gain in energy state. It remains unclear if 'glucose-excited' VMH GABAergic and/or ARH pro-opiomelanocortin neurons exhibit AMPK habituation to RIIH, and whether diminished sensor activation in these and other mediobasal hypothalamic neurotransmitter populations may contribute to HAAF. Copyright © 2017 Elsevier Ltd. All rights reserved.

Amelioration of azoxymethane induced-carcinogenesis by reducing oxidative stress in rat colon by natural extracts

PubMed Central

2014-01-01

Background Azoxymethane (AOM) is a potent carcinogenic agent commonly used to induce colon cancer in rats; the cytotoxicity of AOM is considered to mediate oxidative stress. This study investigated the chemopreventive effect of three natural extracts [pomegranate peel extract (PomPE), papaya peel extract (PapPE) and seaweed extract (SE)] against AOM-induced oxidative stress and carcinogenesis in rat colon. Methods Eighty Sprague–Dawley rats (aged 4 weeks) were randomly divided into 8 groups (10 rats/group). Control group was fed a basal diet; AOM-treated group was fed a basal diet and received AOM intraperitonial injections for two weeks at a dose of 15 mg/kg bodyweight, whereas the other six groups were received oral supplementation of PomPE, PapPE or SE, in the presence or absence of AOM injection. All animals were continuously fed ad-libitum until aged 16 weeks, then all rats were sacrificed and the colon tissues were examined microscopically for pathological changes and aberrant crypt foci (ACF) development, genotoxicity (induced micronuclei (MN) cells enumeration), and glutathione and lipid peroxidation. Results Our results showed that AOM-induced ACF development and pathological changes in the colonic mucosal tissues, increased bone marrow MN cells and oxidative stress (glutathione depletion, lipid peroxidation) in rat colonic cells. The concomitant treatment of AOM with PomPE, PapPE or SE significantly ameliorated the cytotoxic effects of AOM. Conclusions The results of this study provide in-vivo evidence that PomPE, PapPE and SE reduced the AOM-induced colon cancer in rats, through their potent anti-oxidant activities. PMID:24533833

Evaluation of Agaricus blazei in vivo for antigenotoxic, anticarcinogenic, phagocytic and immunomodulatory activities.

PubMed

Ishii, Priscila Lumi; Prado, Carolina Kato; Mauro, Mariana de Oliveira; Carreira, Clísia Mara; Mantovani, Mário Sérgio; Ribeiro, Lúcia Regina; Dichi, Jane Bandeira; Oliveira, Rodrigo Juliano

2011-04-01

The development of various types of cancer results from the interaction among endogenous, environmental and hormonal factors, where the most notable of these factors is diet. The aim of the present study was to determine the antigenotoxic, anticarcinogenic, phagocytic and immunomodulatory activities of Agaricus blazei. The test antigenotoxicity (Comet Assay) and anticarcinogenic (Test of Aberrant Crypt Foci) assess changes in DNA and/or intestinal mucosa that correlate to cancer development. Tests of phagocytosis in the spleen and differential count in blood cells allow the inference of modulation of the immune system as well as to propose a way of eliminating cells with DNA damage. Supplementation with the mushroom was carried out under pre-treatment, simultaneous treatment, post-treatment and pre-treatment+continuous conditions. Statistical analysis demonstrated that the mushroom did not have genotoxic activity but showed antigenotoxic activity. Supplementation caused an increase in the number of monocytes and in phagocytic activity, suggesting that supplementation increases a proliferation of monocytes, consequently increasing phagocytic capacity especially in the groups pre-treatment, simultaneous and pre-treatment+continuous. The data suggest that A. blazei could act as a functional food capable of promoting immunomodulation which can account for the destruction of cells with DNA alterations that correlate with the development of cancer, since this mushroom was demonstrated to have a preventive effect against pre-neoplastic colorectal lesions evaluated by the aberrant crypt foci assay. According to these results and the literature, it is believed that supplementation with A. blazei can be an efficient method for the prevention of cancer as well as possibly being an important coadjuvant treatment in chemotherapy. Copyright © 2011 Elsevier Inc. All rights reserved.

Nonlinear susceptibility and dynamic hysteresis loops of magnetic nanoparticles with biaxial anisotropy

NASA Astrophysics Data System (ADS)

Ouari, Bachir; Titov, Serguey V.; El Mrabti, Halim; Kalmykov, Yuri P.

2013-02-01

The nonlinear ac susceptibility and dynamic magnetic hysteresis (DMH) of a single domain ferromagnetic particle with biaxial anisotropy subjected to both external ac and dc fields of arbitrary strength and orientation are treated via Brown's continuous diffusions model [W. F. Brown, Jr., Phys. Rev. 130, 1677 (1963)] of magnetization orientations. The DMH loops and nonlinear ac susceptibility strongly depend on the dc and ac field strengths, the polar angle between the easy axis of the particle, the external field vectors, temperature, and damping. In contrast to uniaxial particles, the nonlinear ac stationary response and DMH strongly depend on the azimuthal direction of the ac field and the biaxiality parameter Δ.

Genetic-deletion of Cyclooxygenase-2 Downstream Prostacyclin Synthase Suppresses Inflammatory Reactions but Facilitates Carcinogenesis, unlike Deletion of Microsomal Prostaglandin E Synthase-1.

PubMed

Sasaki, Yuka; Kamiyama, Shuhei; Kamiyama, Azusa; Matsumoto, Konomi; Akatsu, Moe; Nakatani, Yoshihito; Kuwata, Hiroshi; Ishikawa, Yukio; Ishii, Toshiharu; Yokoyama, Chieko; Hara, Shuntaro

2015-11-27

Prostacyclin synthase (PGIS) and microsomal prostaglandin E synthase-1 (mPGES-1) are prostaglandin (PG) terminal synthases that function downstream of inducible cyclooxygenase (COX)-2 in the PGI2 and PGE2 biosynthetic pathways, respectively. mPGES-1 has been shown to be involved in various COX-2-related diseases such as inflammatory diseases and cancers, but it is not yet known how PGIS is involved in these COX-2-related diseases. Here, to clarify the pathophysiological role of PGIS, we investigated the phenotypes of PGIS and mPGES-1 individual knockout (KO) or double KO (DKO) mice. The results indicate that a thioglycollate-induced exudation of leukocytes into the peritoneal cavity was suppressed by the genetic-deletion of PGIS. In the PGIS KO mice, lipopolysaccharide-primed pain nociception (as assessed by the acetic acid-induced writhing reaction) was also reduced. Both of these reactions were suppressed more effectively in the PGIS/mPGES-1 DKO mice than in the PGIS KO mice. On the other hand, unlike mPGES-1 deficiency (which suppressed azoxymethane-induced colon carcinogenesis), PGIS deficiency up-regulated both aberrant crypt foci formation at the early stage of carcinogenesis and polyp formation at the late stage. These results indicate that PGIS and mPGES-1 cooperatively exacerbate inflammatory reactions but have opposing effects on carcinogenesis, and that PGIS-derived PGI2 has anti-carcinogenic effects.

Interactive Effects of Dorsomedial Hypothalamic Nucleus and Time-Restricted Feeding on Fractal Motor Activity Regulation.

PubMed

Lo, Men-Tzung; Chiang, Wei-Yin; Hsieh, Wan-Hsin; Escobar, Carolina; Buijs, Ruud M; Hu, Kun

2016-01-01

One evolutionary adaptation in motor activity control of animals is the anticipation of food that drives foraging under natural conditions and is mimicked in laboratory with daily scheduled food availability. Food anticipation is characterized by increased activity a few hours before the feeding period. Here we report that 2-h food availability during the normal inactive phase of rats not only increases activity levels before the feeding period but also alters the temporal organization of motor activity fluctuations over a wide range of time scales from minutes up to 24 h. We demonstrate this multiscale alteration by assessing fractal patterns in motor activity fluctuations-similar fluctuation structure at different time scales-that are robust in intact animals with ad libitum food access but are disrupted under food restriction. In addition, we show that fractal activity patterns in rats with ad libitum food access are also perturbed by lesion of the dorsomedial hypothalamic (DMH)-a neural node that is involved in food anticipatory behavior. Instead of further disrupting fractal regulation, food restriction restores the disrupted fractal patterns in these animals after the DMH lesion despite the persistence of the 24-h rhythms. This compensatory effect of food restriction is more clearly pronounced in the same animals after the additional lesion of the suprachiasmatic nucleus (SCN)-the central master clock in the circadian system that generates and orchestrates circadian rhythms in behavior and physiological functions in synchrony with day-night cycles. Moreover, all observed influences of food restriction persist even when data during the food anticipatory and feeding period are excluded. These results indicate that food restriction impacts dynamics of motor activity at different time scales across the entire circadian/daily cycle, which is likely caused by the competition between the food-induced time cue and the light-entrained circadian rhythm of the SCN. The differential impacts of food restriction on fractal activity control in intact and DMH-lesioned animals suggest that the DMH plays a crucial role in integrating these different time cues to the circadian network for multiscale regulation of motor activity.

Epitalon and colon carcinogenesis in rats: proliferative activity and apoptosis in colon tumors and mucosa.

PubMed

Kossoy, George; Zandbank, Judit; Tendler, Eugenie; Anisimov, Vladimir; Khavinson, Vladimir; Popovich, Irina; Zabezhinski, Mark; Zusman, Itshak; Ben-Hur, Herzl

2003-10-01

The effect of the synthetic pineal peptide Epitalon (Ala-Glu-Asp-Gly) on proliferative activity in colon tumors, and in mucosal epithelial cells adjacent to and located far from tumors was studied in rats. To evaluate the effect of Epitalon on different stages of carcinogenesis, different treatment regimens were used: during the tumor initiation stage, during the tumor-promotion stage, or during the entire process of tumor development. Eighty 2-month-old male LIO rats were exposed weekly to five subcutaneous injections of 1,2-dimethylhydrazine (DMH) at a single dose of 21 mg/kg body weight. Rats were divided into four groups. Control rats (group 1) received saline at a dose of 0.1 ml during the entire experiment. Rats in group 2 were treated with Epitalon at a dose of 1 micro g, five times a week, for 6 months, from the first injection of DMH till the end of the experiment. Rats in group 3 were treated with Epitalon after termination of the carcinogen injections. Rats in group 4 were treated with Epitalon only during the period of DMH exposure (for the first 5 weeks of the experiment). DMH induced proliferation of the secretory epithelium, and this phenomenon was accompanied by a decrease in the size of the stromal area and the area of lymph infiltration in colon tumors and in the colon mucosa adjacent to the tumors (group 1). Epitalon attenuated this effect, especially when the treatment was continued throughout the experiment (group 2). It increased the stromal areas, as well as that of lymphoid infiltration in the colon mucosa adjacent to the tumors. The intensity of lymphoid infiltration was activated in both the colon mucosa adjacent to a tumor and in the tumor. Mitotic activity of tumor cells was significantly inhibited by Epitalon when the treatment was given throughout the experiment (group 2). In parallel, a high level of apoptosis was seen in the same group. Thus, the strongest inhibitory effect of Epitalon on carcinogenesis in the colon mucosa was manifested when the treatment was continued throughout the experiment.

Exercise reduces inflammation and cell proliferation in rat colon carcinogenesis.

PubMed

Demarzo, Marcelo Marcos Piva; Martins, Lisandra Vanessa; Fernandes, Cleverson Rodrigues; Herrero, Fábio Augusto; Perez, Sérgio Eduardo de Andrade; Turatti, Aline; Garcia, Sérgio Britto

2008-04-01

There is evidence that the risk of colon cancer is reduced by appropriate levels of physical exercise. Nevertheless, the mechanisms involved in this protective effect of exercise remain largely unknown. Inflammation is emerging as a unifying link between a range of environment exposures and neoplastic risk. The carcinogen dimethyl-hydrazine (DMH) induces an increase in epithelial cell proliferation and in the expression of the inflammation-related enzyme cyclooxigenase-2 (COX-2) in the colon of rats. Our aim was to verify whether these events could be attenuated by exercise. Four groups of eight Wistar rats were used in the experiment. The groups G1 and G3 were sedentary (controls), and the groups G2 and G4 were submitted to 8 wk of swimming training, 5 d.wk. The groups G3 and G4 were given subcutaneous injections of DMH immediately after the exercise protocols. Fifteen days after the neoplasic induction, the rats were sacrificed and the colon was processed for histological examination and immunohistochemistry staining of proliferating cell nuclear antigen (PCNA) and COX-2. We found a significant increase in the PCNA-labeling index in both DMH-treated groups of rats. However, this increase was significantly attenuated in the training group G4 (P < 0.01). Similar results were observed in relation to the COX-2 expression. From our findings, we conclude that exercise training exerts remarkable antiproliferative and antiinflammatory effects in the rat colonic mucosa, suggesting that this may be an important mechanism to explain how exercise protects against colonic cancer.

Postsynaptic Depolarization Enhances GABA Drive to Dorsomedial Hypothalamic Neurons through Somatodendritic Cholecystokinin Release.

PubMed

Crosby, Karen M; Baimoukhametova, Dinara V; Bains, Jaideep S; Pittman, Quentin J

2015-09-23

Somatodendritically released peptides alter synaptic function through a variety of mechanisms, including autocrine actions that liberate retrograde transmitters. Cholecystokinin (CCK) is a neuropeptide expressed in neurons in the dorsomedial hypothalamic nucleus (DMH), a region implicated in satiety and stress. There are clear demonstrations that exogenous CCK modulates food intake and neuropeptide expression in the DMH, but there is no information on how endogenous CCK alters synaptic properties. Here, we provide the first report of somatodendritic release of CCK in the brain in male Sprague Dawley rats. CCK is released from DMH neurons in response to repeated postsynaptic depolarizations, and acts in an autocrine fashion on CCK2 receptors to enhance postsynaptic NMDA receptor function and liberate the retrograde transmitter, nitric oxide (NO). NO subsequently acts presynaptically to enhance GABA release through a soluble guanylate cyclase-mediated pathway. These data provide the first demonstration of synaptic actions of somatodendritically released CCK in the hypothalamus and reveal a new form of retrograde plasticity, depolarization-induced potentiation of inhibition. Significance statement: Somatodendritic signaling using endocannabinoids or nitric oxide to alter the efficacy of afferent transmission is well established. Despite early convincing evidence for somatodendritic release of neurohypophysial peptides in the hypothalamus, there is only limited evidence for this mode of release for other peptides. Here, we provide the first evidence for somatodendritic release of the satiety peptide cholecystokinin (CCK) in the brain. We also reveal a new form of synaptic plasticity in which postsynaptic depolarization results in enhancement of inhibition through the somatodendritic release of CCK. Copyright © 2015 the authors 0270-6474/15/3513160-11$15.00/0.

77 FR 51615 - DMH Trust fbo Martha M. Head-Acquisition of Control Exemption-Twin Cities & Western Railroad...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-24

... Martha M. Head--Acquisition of Control Exemption-- Twin Cities & Western Railroad Company, Minnesota Prairie Line, Inc. and Sisseton Milbank Railroad Company DMH Trust fbo Martha M. Head (the Trust), a... Class III rail carriers. \\1\\ MPL and SMRC are wholly owned subsidiaries of TCW. According to the Trust...

77 FR 47493 - DMH Trust fbo Martha M. Head-Acquisition of Control Exemption-Red River Valley & Western Railroad...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-08

... Martha M. Head--Acquisition of Control Exemption-- Red River Valley & Western Railroad and Rutland Line, Inc. DMH Trust fbo Martha M. Head (the Trust), a noncarrier, has filed a verified notice of exemption...\\ both Class III rail carriers. \\1\\ RLI is a wholly owned subsidiary of RRVW. According to the Trust...

Refractive Changes Induced by Spherical Aberration in Laser Correction Procedures: An Adaptive Optics Study.

PubMed

Amigó, Alfredo; Martinez-Sorribes, Paula; Recuerda, Margarita

2017-07-01

To study the effect on vision of induced negative and positive spherical aberration within the range of laser vision correction procedures. In 10 eyes (mean age: 35.8 years) under cyclopegic conditions, spherical aberration values from -0.75 to +0.75 µm in 0.25-µm steps were induced by an adaptive optics system. Astigmatism and spherical refraction were corrected, whereas the other natural aberrations remained untouched. Visual acuity, depth of focus defined as the interval of vision for which the target was still perceived acceptable, contrast sensitivity, and change in spherical refraction associated with the variation in pupil diameter from 6 to 2.5 mm were measured. A refractive change of 1.60 D/µm of induced spherical aberration was obtained. Emmetropic eyes became myopic when positive spherical aberration was induced and hyperopic when negative spherical aberration was induced (R 2 = 81%). There were weak correlations between spherical aberration and visual acuity or depth of focus (R 2 = 2% and 3%, respectively). Contrast sensitivity worsened with the increment of spherical aberration (R 2 = 59%). When pupil size decreased, emmetropic eyes became hyperopic when preexisting spherical aberration was positive and myopic when spherical aberration was negative, with an average refractive change of 0.60 D/µm of spherical aberration (R 2 = 54%). An inverse linear correlation exists between the refractive state of the eye and spherical aberration induced within the range of laser vision correction. Small values of spherical aberration do not worsen visual acuity or depth of focus, but positive spherical aberration may induce night myopia. In addition, the changes in spherical refraction when the pupil constricts may worsen near vision when positive spherical aberration is induced or improve it when spherical aberration is negative. [J Refract Surg. 2017;33(7):470-474.]. Copyright 2017, SLACK Incorporated.

Changes in cell proliferation and morphology in the large intestine of normal and DMH-treated rats following colostomy.

PubMed

Barkla, D H; Tutton, P J

1987-04-01

Colostomies were formed in the midcolon of normal and DMH-treated rats. Changes in cell proliferation in the mucosa adjacent to the colostomy and in the defunctioned distal segment were measured at seven, 14, 30, and 72 days using a stathmokinetic technique. Animals were given intraperitoneal injections of vinblastine and sacrificed three hours later; counts of mitotic and nonmitotic cells were made in tissue sections, and three-hour accumulated mitotic indexes were estimated. The results show that, except at seven days in DMH-treated rats, cell proliferation was unchanged in the colon proximal to the colostomy. Morphologic evidence of hyperplasia was seen in some animals at seven and 14 days. The defunctioned segment showed rapid atrophy of both mucosa and muscularis and a gradual but progressive decrease in cell proliferation. The morphology of the mucosa adjacent to the suture line in both functioning and defunctioned segments in normal and DMH-treated rats was abnormal in many animals. Abnormalities that were seen included collections of dysplastic epithelial cells in the submucosa, focal adenomatous changes, and intramural carcinoma formation. Aggregates of lymphoid tissue often were associated with carcinomas.

Structural Stability of Human Fibroblast Growth Factor-1 Is Essential for Protective Effects Against Radiation-Induced Intestinal Damage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakayama, Fumiaki, E-mail: f_naka@nirs.go.jp; Umeda, Sachiko; Yasuda, Takeshi

2013-02-01

Purpose: Human fibroblast growth factor-1 (FGF1) has radioprotective effects on the intestine, although its structural instability limits its potential for practical use. Several stable FGF1 mutants were created increasing stability in the order, wild-type FGF1, single mutants (Q40P, S47I, and H93G), Q40P/S47I, and Q40P/S47I/H93G. This study evaluated the contribution of the structural stability of FGF1 to its radioprotective effect. Methods and Materials: Each FGF1 mutant was administered intraperitoneally to BALB/c mice in the absence of heparin 24 h before or after total body irradiation (TBI) with {gamma}-rays at 8-12 Gy. Several radioprotective effects were examined in the jejunum. Results: Q40P/S47I/H93Gmore » could activate all subtypes of FGF receptors in vitro much more strongly than the wild-type without endogenous or exogenous heparin. Preirradiation treatment with Q40P/S47I/H93G significantly increased crypt survival more than wild-type FGF1 after TBI at 10 or 12 Gy, and postirradiation treatment with Q40P/S47I/H93G was effective in promoting crypt survival after TBI at 10, 11, or 12 Gy. In addition, crypt cell proliferation, crypt depth, and epithelial differentiation were significantly promoted by postirradiation treatment with Q40P/S47I/H93G. The level of stability of FGF1 mutants correlated with their mitogenic activities in vitro in the absence of heparin; however, preirradiation treatment with the mutants increased the crypt number to almost the same level as Q40P/S47I/H93G. When given 24 h after TBI at 10 Gy, all FGF1 mutants increased crypt survival more than wild-type FGF1, and Q40P/S47I/H93G had the strongest mitogenic effects in intestinal epithelial cells after radiation damage. Moreover, Q40P/S47I/H93G prolonged mouse survival after TBI because of the repair of intestinal damage. Conclusion: These findings suggest that the structural stability of FGF1 can contribute to the enhancement of protective effects against radiation-induced intestinal damage. Therefore, Q40P/S47I/H93G is pharmacologically one of the most promising candidates for clinical applications for radiation-induced gastrointestinal syndrome.« less

Experiment K-6-17. Structural changes and cell turnover in the rats small intestine induced by spaceflight

NASA Technical Reports Server (NTRS)

Phillips, R. W.; Sawyer, H. R.; Smirnov, K. V.

1990-01-01

The purpose of this project was to test the hypothesis that the generalized, whole body decrease in synthetic activity associated with microgravity conditions of space flight as evidenced by negative nitrogen balance and muscle atrophy (Nicogossian and Parker, 1982; Oganov, 1981), as well as inhibited lymphocyte proliferation (Bechler and Cogoli, 1986), would be evident in cells characterized by a rapid rate of turnover. As a model, researchers chose to study the turnover of mucosal cells lining the jejunum of the small intestine, since these cells are among the most rapidly proliferating in the body. Under normal conditions, epithelial cells that line the small intestine are continually produced in the crypts of Lieberkuhn. These cells migrate out of the crypts onto intestinal villi, are progressively pushed up the villus as new crypt cells are formed, and ultimately reach the tip of villi where they are then descquamated. In rats, the entire process, from initial proliferation in crypts to desquamation, takes approximately 2 days (Cairnie et al., 1965; Lipkin, 1973). In this study, researchers determined the mitotic index for mucosal cells lining the proximal, middle, and distal regions of the jejunum in rats from three treatment groups (synchronous control, vivarium control and flight), and measured the depth of the crypts of Lieberkuhn and the length of villi present in each of the three jejunal regions sampled.

Mast cell regulation of Na-glutamine co-transporters B0AT1 in villus and SN2 in crypt cells during chronic intestinal inflammation.

PubMed

Singh, Soudamani; Arthur, Subha; Talukder, Jamilur; Palaniappan, Balasubramanian; Coon, Steven; Sundaram, Uma

2015-04-15

In the chronically inflamed rabbit small intestine, brush border membrane (BBM) Na-glutamine co-transport is inhibited in villus cells (mediated by B0AT1), while it is stimulated in crypt cells (mediated by SN2/SNAT5). How mast cells, known to be enhanced in the chronically inflamed intestine, may regulate B0AT1 in villus and SN2/SNAT5 in crypt cell is unknown. Thus, the aim of the present study is to determine the regulation of B0AT1 and SN2/SNAT5 by mast cells during chronic enteritis. Chronic intestinal inflammation was induced in male rabbits with intra-gastric inoculation of Eimeria magna oocytes. Rabbits with chronic inflammation were treated with ketotifen (10 mg/day) or saline (Placebo) for 2 days. Villus and crypts cells were isolated from the rabbit intestine using the Ca++ chelation technique. Na/K-ATPase activity was measured as Pi from cellular homogenate. BBM vesicles (BBMV) were prepared from villus and crypt cells and uptake studies were performed using rapid filtration technique with (3)H-Glutamine. Western blot analyses were done using B0AT1 and SN2 specific antibodies. In villus cells, Na-glutamine co-transport inhibition observed during inflammation was completely reversed by ketotifen, a mast cell stabilizer. In contrast, in crypt cells, Na-glutamine co-transport stimulation was reversed to normal levels by ketotifen. Kinetic studies demonstrated that ketotifen reversed the inhibition of B0AT1 in villus cells by restoring co-transporter numbers in the BBM, whereas the stimulation of SN2/SNAT5 in crypts cells was reversed secondary to restoration of affinity of the co-transporter. Western blot analysis showed that ketotifen restored immune-reactive levels of B0AT1 in villus cells, while SN2/SNAT5 levels from crypts cell remained unchanged. In the present study we demonstrate that mast cells likely function as a common upstream immune pathway regulator of the Na-dependent glutamine co-transporters, B0AT1 in villus cells and SN2 in crypts cells that are uniquely altered in the chronically inflamed small intestine.

Mesenchymal stem cells cancel azoxymethane-induced tumor initiation.

PubMed

Nasuno, Masanao; Arimura, Yoshiaki; Nagaishi, Kanna; Isshiki, Hiroyuki; Onodera, Kei; Nakagaki, Suguru; Watanabe, Shuhei; Idogawa, Masashi; Yamashita, Kentaro; Naishiro, Yasuyoshi; Adachi, Yasushi; Suzuki, Hiromu; Fujimiya, Mineko; Imai, Kohzoh; Shinomura, Yasuhisa

2014-04-01

The role of mesenchymal stem cells (MSCs) in tumorigenesis remains controversial. Therefore, our goal was to determine whether exogenous MSCs possess intrinsic antineoplastic or proneoplastic properties in azoxymethane (AOM)-induced carcinogenesis. Three in vivo models were studied: an AOM/dextran sulfate sodium colitis-associated carcinoma model, an aberrant crypt foci model, and a model to assess the acute apoptotic response of a genotoxic carcinogen (AARGC). We also performed in vitro coculture experiments. As a result, we found that MSCs partially canceled AOM-induced tumor initiation but not tumor promotion. Moreover, MSCs inhibited the AARGC in colonic epithelial cells because of the removal of O(6)-methylguanine (O(6) MeG) adducts through O(6) MeG-DNA methyltransferase activation. Furthermore, MSCs broadly affected the cell-cycle machinery, potentially leading to G1 arrest in vivo. Coculture of IEC-6 rat intestinal cells with MSCs not only arrested the cell cycle at the G1 phase, but also induced apoptosis. The anti-carcinogenetic properties of MSCs in vitro required transforming growth factor (TGF)-β signaling because such properties were completely abrogated by absorption of TGF-β under indirect coculture conditions. MSCs inhibited AOM-induced tumor initiation by preventing the initiating cells from sustaining DNA insults and subsequently inducing G1 arrest in the initiated cells that escaped from the AARGC. Furthermore, tumor initiation perturbed by MSCs might potentially dysregulate WNT and TGF-β-Smad signaling pathways in subsequent tumorigenesis. Obtaining a better understanding of MSC functions in colon carcinogenesis is essential before commencing the broader clinical application of promising MSC-based therapies for cancer-prone patients with inflammatory bowel disease. © AlphaMed Press.

C/EBPδ deficiency sensitizes mice to ionizing radiation-induced hematopoietic and intestinal injury.

PubMed

Pawar, Snehalata A; Shao, Lijian; Chang, Jianhui; Wang, Wenze; Pathak, Rupak; Zhu, Xiaoyan; Wang, Junru; Hendrickson, Howard; Boerma, Marjan; Sterneck, Esta; Zhou, Daohong; Hauer-Jensen, Martin

2014-01-01

Knowledge of the mechanisms involved in the radiation response is critical for developing interventions to mitigate radiation-induced injury to normal tissues. Exposure to radiation leads to increased oxidative stress, DNA-damage, genomic instability and inflammation. The transcription factor CCAAT/enhancer binding protein delta (Cebpd; C/EBPδ is implicated in regulation of these same processes, but its role in radiation response is not known. We investigated the role of C/EBPδ in radiation-induced hematopoietic and intestinal injury using a Cebpd knockout mouse model. Cebpd-/- mice showed increased lethality at 7.4 and 8.5 Gy total-body irradiation (TBI), compared to Cebpd+/+ mice. Two weeks after a 6 Gy dose of TBI, Cebpd-/- mice showed decreased recovery of white blood cells, neutrophils, platelets, myeloid cells and bone marrow mononuclear cells, decreased colony-forming ability of bone marrow progenitor cells, and increased apoptosis of hematopoietic progenitor and stem cells compared to Cebpd+/+ controls. Cebpd-/- mice exhibited a significant dose-dependent decrease in intestinal crypt survival and in plasma citrulline levels compared to Cebpd+/+ mice after exposure to radiation. This was accompanied by significantly decreased expression of γ-H2AX in Cebpd-/- intestinal crypts and villi at 1 h post-TBI, increased mitotic index at 24 h post-TBI, and increase in apoptosis in intestinal crypts and stromal cells of Cebpd-/- compared to Cebpd+/+ mice at 4 h post-irradiation. This study uncovers a novel biological function for C/EBPδ in promoting the response to radiation-induced DNA-damage and in protecting hematopoietic and intestinal tissues from radiation-induced injury.

Effects of glucocorticoid hormones on cell proliferation in dimethylhydrazine-induced tumours in rat colon.

PubMed

Tutton, P J; Barkla, D H

1981-01-01

Adrenocortical hormones have previously been shown to influence cell proliferation in many tissues. In this report, their influence on cell proliferation in the colonic crypt epithelium and in colonic adenocarcinomata is compared. Colonic tumour cell proliferation was found to be retarded following adrenalectomy and this retardation was reversible by administration of hydrocortisone, or by administration of synthetic steroids with predominantly glucocorticoid activity. Tumour cell proliferation in adrenalectomized rats was not promoted by the mineralocorticoid hormone aldosterone. Neither adrenalectomy, nor adrenocortical hormone treatment, significantly influenced colonic crypt cell proliferation.

77 FR 43146 - Twin Cities & Western Railroad Company, the Estate of Douglas M. Head, and the DMH Trust fbo...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-23

... & Western Railroad Company, the Estate of Douglas M. Head, and the DMH Trust fbo Martha M. Head--Continuance... Class III rail carrier, and the Estate of Douglas M. Head (the Estate), a noncarrier, to continue in control of Sisseton Milbank Railroad Company (SMRC) upon SMRC's becoming a Class III rail carrier in a...

Up-regulation of p53 and mitochondrial signaling pathway in apoptosis by a combination of COX-2 inhibitor, Celecoxib and Dolastatin 15, a marine mollusk linear peptide in experimental colon carcinogenesis.

PubMed

Piplani, Honit; Vaish, Vivek; Rana, Chandan; Sanyal, Sankar N

2013-11-01

Programmed cell death, also known as apoptosis, is an active process occurring in eukaryotic cells and it depends on various sets of pro and anti-apoptotic proteins. Chemoprevention of colorectal cancer can be achieved by inducing apoptosis using synthetic compound, Celecoxib and natural peptide, Dolastatin 15 in an effective manner. But the apoptotic signaling by these two drugs remain unclear. The present study was thus focused on the role of Bcl2 family of proteins and their interplay with p53 in rats during the chemoprevention by these two drugs. After treatment for 6 wk with 1, 2-dimethylhydrazine (DMH), animals showed a marked occurrence of multiple plaque lesions. However, a simultaneous treatment with Celecoxib and Dolastatin 15 decreases such number to a significant level. DMH treatment also decreases the number of apoptotic cells in the colonic enterocytes which were corrected to the normal level by Celecoxib and Dolastatin 15. An increased expression of Bcl2 while other proteins like Bax, Apaf-1, cyt c, and caspases in the apoptotic pathway, and the tumor suppressor proteins, p53 and p21 get down-regulated after DMH treatment which were reverted back to normal with Celecoxib and Dolastatin 15. Also, cells having high mitochondrial membrane potential had been seen to increase to significant levels which were reduced after the administration of these anti-inflammatory drugs. In silico molecular docking studies also showed that Dolastatin 15 and Celecoxib may bind to the active site pocket of Bcl2 , thus revealing the direct target of Dolastatin 15 and Celecoxib apart from binding to COX-2. © 2012 Wiley Periodicals, Inc.

Lack of promotion of colon carcinogenesis by high-oleic safflower oil.

PubMed

Takeshita, M; Ueda, H; Shirabe, K; Higuchi, Y; Yoshida, S

1997-04-15

The nonpromoting effect of olive oil on colon carcinogenesis has been attributed to its high oleic acid content, whereas a positive association of monounsaturated fat in beef tallow with colon tumors has been reported. The effect of constituents other than fatty acids could not be neglected in these experiments. In order to minimize the effects of minor constituents in the oils, the authors compared conventional safflower oil with oil from a mutant strain of safflower that is rich in oleic acid. ICR mice were treated with 1,2-dimethylhydrazine (DMH, 20 mg/kg body weight every week for 12 weeks) and then were fed either a high-fat diet (23.5% by weight), containing safflower oil (HF-LA) or high-oleic safflower oil (HF-OA), or a low-fat diet (5% by weight), containing safflower oil (LF-LA) or high-oleic safflower oil (LF-OA). The test diets were continued until termination of the experiment at 30 weeks after the first administration of DMH. Fatty acid composition of colon phospholipids was determined by gas-liquid chromatography-mass spectrometry. Tumor multiplicity in animals fed the HF-OA diet was indistinguishable from that in animals fed LF-LA or LF-OA. In contrast, animals fed the HF-LA diet had a significantly higher incidence of colon tumors (mostly adenocarcinomas) than the other groups. Fatty acid profiles of colon phospholipids reflected those of the diet. Animals fed a HF-LA diet showed a marked decrease of nervonic acid (C24:1, n-9) in the colon sphingomyelin. These data indicate that oleic acid does not enhance DMH-induced colon carcinogenesis in mice, even when they are fed a high-fat diet.

Magnolol and Honokiol Attenuate Apoptosis of Enterotoxigenic Escherichia Coli-Induced Intestinal Epithelium by Maintaining Secretion and Absorption Homeostasis and Protecting Mucosal Integrity.

PubMed

Deng, Yanli; Han, Xuefeng; Tang, Shaoxun; Li, Chengjian; Xiao, Wenjun; Tan, Zhiliang

2018-05-21

BACKGROUND The cortex of Magnolia officinalis has long been used as an element of traditional Chinese medicine for the treatment of anxiety, chronic bronchitis, and gastrointestinal dysfunction. This study aimed to elucidate the underlying mechanism of its functional ingredients (magnolol and honokiol) in modifying the secretion and absorption homeostasis and protecting mucosal integrity in an Enterotoxigenic Escherichia coli (ETEC)-induced diarrhea mouse model. MATERIAL AND METHODS This study established a diarrhea mouse model infected by ETEC at a dosage of 0.02 ml/g live body weight (BW) in vivo. Magnolol or honokiol was followed by an intraperitoneal administration at dosages of 100, 300, and 500 mg/kg BW according to a 3×3 factorial arrangement. The useful biomarkers for evaluating the integrity of intestinal tract and histologic injury were analyzed and morphological development (including villus height, crypt depth, and ratio of villus height to crypt depth) and the expressions of inflammatory cytokines were determined by real-time PCR. RESULTS The results showed that magnolol and honokiol (500 mg/kg BW) reduced the concentrations of NO, DAO, and DLA, and iNOS activity, and the mRNA expressions of the interferon gamma (IFN-γ) and interleukin 10 (IL-10), and inhibited intestinal epithelial cell apoptosis. Magnolol and honokiol (300 mg/kg BW) elongated the villus height and crypt depth and decreased the number of goblet cells and the ratio of villus height to crypt depth. CONCLUSIONS The current results indicate that magnolol and honokiol enhance the intestinal anti-inflammatory capacities, elongate the villus height and crypt depth, and reduce goblet cell numbers to inhibit the intestinal epithelium apoptosis and effectively protect the intestinal mucosa. These results show that magnolol and honokiol protect the intestinal mucosal integrity and regulate gastrointestinal dysfunction.

Characterization of the cell polarity gene crumbs during the early development and maintenance of the squid-vibrio light organ symbiosis.

PubMed

Peyer, Suzanne M; Heath-Heckman, Elizabeth A C; McFall-Ngai, Margaret J

2017-11-01

The protein Crumbs is a determinant of apical-basal cell polarity and plays a role in apoptosis of epithelial cells and their protection against photodamage. Using the squid-vibrio system, a model for development of symbiotic partnerships, we examined the modulation of the crumbs gene in host epithelial tissues during initiation and maintenance of the association. The extracellular luminous symbiont Vibrio fischeri colonizes the apical surfaces of polarized epithelia in deep crypts of the Euprymna scolopes light organ. During initial colonization each generation, symbiont harvesting is potentiated by the biochemical and biophysical activity of superficial ciliated epithelia, which are several cell layers from the crypt epithelia where the symbionts reside. Within hours of crypt colonization, the symbionts induce the cell death mediated regression of the remote superficial ciliated fields. However, the crypt cells directly interacting with the symbiont are protected from death. In the squid host, we characterized the gene and encoded protein during light organ morphogenesis and in response to symbiosis. Features of the protein sequence and structure, phylogenetic relationships, and localization patterns in the eye supported assignment of the squid protein to the Crumbs family. In situ hybridization revealed that the crumbs transcript shows opposite expression at the onset of symbiosis in the two different regions of the light organ: elevated levels in the superficial epithelia were attenuated whereas low levels in the crypt epithelia were turned up. Although a rhythmic association in which the host controls the symbiont population over the day-night cycle begins in the juvenile upon colonization, cycling of crumbs was evident only in the adult organ with peak expression coincident with maximum symbiont population and luminescence. Our results provide evidence that crumbs responds to symbiont cues that induce developmental apoptosis and to symbiont population dynamics correlating with luminescence-based stress throughout the duration of the host-microbe association.

Temporal and regional onset of leptin resistance in diet-induced obese mice.

PubMed

Rizwan, M Z; Mehlitz, S; Grattan, D R; Tups, A

2017-10-01

In common forms of obesity, leptin fails to convey its regulatory effect. This so called "leptin resistance" is not well understood, and solving this puzzle is a key to understanding how obesity develops. In the present study, we investigated the temporal and regional onset of leptin resistance in response to a diet enriched with long-chain saturated fatty acids (high-fat diet; HFD) in mice. Mice were exposed to either a low-fat diet (LFD) or a HFD for 4 hours, 24 hours, 10 days and 28 days. Mice in each group received an i.p. injection of either phosphate-buffered saline or leptin and the number of phosphorylated signal transducer and activator of transcription-3 (pSTAT3) immunoreactive (-IR) cells in the arcuate nucleus (ARC), ventromedial nucleus of the hypothalamus (VMH) and dorsomedial nucleus of the hypothalamus (DMH) was analysed 30 or 120 minutes after treatment. In the ARC, as soon as 24 hours of HFD, the molecular leptin response was reduced by 40% (P≤.01). Compared to at 24 hours, after 10 days, the number of leptin-induced pSTAT3-IR cells was elevated after 120 minutes, suggesting a sustained response and a partial return of leptin sensitivity. After 28 days, leptin failed to induce the number of pSTAT3-IR over control levels, suggesting a markedly reduced sensitivity to leptin. In the VMH after 24 hours, we observed a 50% reduction in leptin-induced pSTAT-3-IR cells, followed by a further decline after 10 days. However, after 28 days, there was a significant increase in pSTAT-3-IR cells (P≤.05), indicating partial recovery of leptin sensitivity. By contrast to these two regions, in the DMH, no loss of leptin sensitivity was observed at any time-point. These findings demonstrate that a loss of sensitivity to leptin occurs rapidly after exposure to HFD in the ARC and VMH but not the DMH. However, there appears to be a biphasic pattern of leptin responsiveness, with a partial return of leptin sensitivity occurring after 10 days in the arcuate nucleus, and after 28 days in the VMH. By 28 days, the response to leptin in the arcuate nucleus was completely lost. These findings suggest that the molecular responses to leptin are altered after high-fat feeding in a time- and region-specific manner. © 2017 British Society for Neuroendocrinology.

Chemical and Molecular Biological Aspects of Alkylhydrazine-Induced Carcinogenesis in Human Cells in Vitro. Revised

DTIC Science & Technology

1984-04-01

weights using the following phage DNA markers : lambda, T2 and T7. The number of alkaline labile sites (breaks due to apurinic sites and phosphotriesters...exhibit cell invasiveness in chick embryo skin, human malignancy specific cell- surface antigenic determinants (19), and produce tumors in pre...they eluted from the column, were identified by co-chromatographed markers , (Chart 2). When randomly proliferating cells were treated with either 1,1-DMH

Distraction induced enterogenesis: a unique mouse model using polyethylene glycol.

PubMed

Okawada, Manabu; Maria, Haytham Mustafa; Teitelbaum, Daniel H

2011-09-01

Recent studies have demonstrated that the small intestine can be lengthened by applying mechanical forces to the bowel lumen-distraction-induced enterogenesis. However, the mechanisms which account for this growth are unknown, and might be best examined using a mouse model. The purpose of this study is to establish the feasibility of developing distractive-induced small bowel growth in mouse. Twelve-week old C57BL/6J mice had a jejunal segment taken out of continuity, and distended with polyethylene glycol (PEG: 3350 KDa); this group was compared with a control group without stretching. Segment length and diameter were measured intra-operatively and after 5 d. Villus height, crypt depth, and muscle thickness in the isolated segment were assessed. Rate of epithelial cell proliferation (5-bromo-2-deoxyuridine: BrdU incorporation) in crypts were also examined. The mucosal mRNA expression of targeted factors was performed to investigate potential mechanisms which might lead to distraction-induced enterogenesis. At harvest, the PEG-stretched group showed a significant increase in length and diameter versus controls. Villus height, crypt depth, and muscular layer thickness increased in the PEG group. The PEG group also showed significantly increased rates of epithelial cell proliferation versus controls. Real-time PCR showed a trend toward higher β-catenin and c-myc mRNA expression in the PEG-stretched group; however, this difference was not statistically significant. Radial distraction-induced enterogenesis with PEG is a viable method for increasing small intestinal length and diameter. This model may provide a new method for studying the mechanisms leading to distraction-induced enterogenesis. Copyright © 2011 Elsevier Inc. All rights reserved.

Kenaf seed supercritical fluid extract reduces aberrant crypt foci formation in azoxymethane-induced rats.

PubMed

Ghafar, Siti Aisyah Abd; Yazan, Latifah Saiful; Tahir, Paridah Md; Ismail, Maznah

2012-03-01

Kenaf (Hibiscus cannabinus) a plant of the family Malvaceae, is a valuable fiber plant native to India and Africa. Kenaf seeds contain alpha-linolenic acid, phytosterol such as β-sitosterol, vitamin E and other antioxidants with chemopreventive properties. In the present study we examined the hypothesis that kenaf seed 'supercritical fluid extract' (SFE) extract could suppress the early colon carcinogenesis in vivo by virtue of its bioactive compounds. To accomplish this goal, 60 male rats were randomly assigned to 5 groups which were (1) negative control group [not induced with azoxymethane (AOM)]; (2) positive control group (induced with AOM but received no treatment); (3) group treated with 500 mg/kg kenaf seed SFE extract; (4) group treated with 1000 mg/kg kenaf seed SFE extract; (5) group treated with 1500 mg/kg kenaf seed SFE extract. At 7 weeks of age, all rats except the negative control group received 15 mg/kg of AOM injection subcutaneously once a week for 2 weeks. Rats were euthanized at 13 weeks of the experiment. Number of ACF (mean±SD) ranged from 84.4±4.43 to 179.5±12.78 in group 2, 3, 4, 5. ACF reductions compared with the untreated group were 45.3, 51.4 and 53.1% in rats fed with 500, 1000 and 1500 mg/kg body weight, respectively. There were no significant differences in weight gain among groups. Our finding indicates that kenaf seed SFE extract reduced AOM-induced ACF in Sprague-Dawley male rats. Copyright © 2010 Elsevier GmbH. All rights reserved.

Aberrant Epithelial-Mesenchymal Hedgehog Signaling Characterizes Barrett's Metaplasia

PubMed Central

Wang, David H.; Clemons, Nicholas J.; Miyashita, Tomoharu; Dupuy, Adam J.; Zhang, Wei; Szczepny, Anette; Corcoran-Schwartz, Ian M.; Wilburn, Daniel L.; Montgomery, Elizabeth A.; Wang, Jean S.; Jenkins, Nancy A.; Copeland, Neal A.; Harmon, John W.; Phillips, Wayne A.; Watkins, D. Neil

2010-01-01

Background & Aims The molecular mechanism underlying epithelial metaplasia in Barrett's esophagus remains unknown. Recognizing that Hedgehog signaling is required for early esophageal development, we sought to determine if the Hedgehog pathway is reactivated in Barrett's esophagus, and if genes downstream of the pathway could promote columnar differentiation of esophageal epithelium. Methods Immunohistochemistry, immunofluorescence, and quantitative real-time PCR were used to analyze clinical specimens, human esophageal cell lines, and mouse esophagi. Human esophageal squamous epithelial (HET-1A) and adenocarcinoma (OE33) cells were subjected to acid treatment and used in transfection experiments. Swiss Webster mice were used in a surgical model of bile reflux injury. An in vivo transplant culture system was created using esophageal epithelium from Sonic hedgehog transgenic mice. Results Marked upregulation of Hedgehog ligand expression, which can be induced by acid or bile exposure, occurs frequently in Barrett's epithelium and is associated with stromal expression of the Hedgehog target genes PTCH1 and BMP4. BMP4 signaling induces expression of SOX9, an intestinal crypt transcription factor, which is highly expressed in Barrett's epithelium. We further show that expression of DMBT1, the human homologue of the columnar cell factor Hensin, occurs in Barrett's epithelium and is induced by SOX9. Finally, transgenic expression of Sonic hedgehog in mouse esophageal epithelium induces expression of stromal Bmp4, epithelial Sox9 and columnar cytokeratins. Conclusions Epithelial Hedgehog ligand expression may contribute to the initiation of Barrett's esophagus through induction of stromal BMP4, which triggers reprogramming of esophageal epithelium in favor of a columnar phenotype. PMID:20138038

Inhibition of beta-catenin and KRAS expressions by Piper betle in azoxymethane-induced colon cancer of male Fischer 344 rats.

PubMed

Esa, Faezah; Ngah, Wan Zurinah Wan; Jamal, A Rahman A; Mohd Yusof, Yasmin Anum

2013-12-01

To investigate the chemopreventive effect of Piper betle (PB) on preneoplastic lesions (aberrant crypt foci [ACF]) induced by azoxymethane (AOM) in rats and its effect on colorectal cancer biomarkers (beta-catenin, KRAS, p53 and p21). A total of 32 male Fischer 344 rats were divided into phase 1 and phase 2 groups (8 and 24 weeks of AOM administration, respectively). Each phase was divided into 4 groups: control or normal saline (NS) (1 mL/kg), AOM (15 mg/kg body weight, once weekly for 2 weeks), PB (75 mg/kg body weight) and AOM + PB. PB was force-fed to rats a week after the second dose of AOM and NS. The colon was cut open longitudinally for methylene blue and immunohistochemistry staining. AOM administration showed formation of ACF at 8 and 24 weeks. PB, however, did not reduce ACF formation at either week, but it managed to reduce beta-catenin expression and KRAS found highly expressed in the AOM group of phase 1 rats. No immunoreactivities of p53 and p21 were detected in phase 2 rats, but instead inflammatory cells were visible in between the lesions. PB may act as a potential chemopreventive agent in the early stage of colon carcinogenesis by suppressing the expressions of beta-catenin and KRAS.

The AOM/DSS murine model for the study of colon carcinogenesis: From pathways to diagnosis and therapy studies

PubMed Central

Robertis, Mariangela De; Massi, Emanuela; Poeta, Maria Luana; Carotti, Simone; Morini, Sergio; Cecchetelli, Loredana; Signori, Emanuela; Fazio, Vito Michele

2011-01-01

Colorectal cancer (CRC) is a major health problem in industrialized countries. Although inflammation-linked carcinogenesis is a well accepted concept and is often observed within the gastrointestinal tract, the underlying mechanisms remain to be elucidated. Inflammation can indeed provide initiating and promoting stimuli and mediators, generating a tumour-prone microenvironment. Many murine models of sporadic and inflammation-related colon carcinogenesis have been developed in the last decade, including chemically induced CRC models, genetically engineered mouse models, and xenoplants. Among the chemically induced CRC models, the combination of a single hit of azoxymethane (AOM) with 1 week exposure to the inflammatory agent dextran sodium sulphate (DSS) in rodents has proven to dramatically shorten the latency time for induction of CRC and to rapidly recapitulate the aberrant crypt foci–adenoma–carcinoma sequence that occurs in human CRC. Because of its high reproducibility and potency, as well as the simple and affordable mode of application, the AOM/DSS has become an outstanding model for studying colon carcinogenesis and a powerful platform for chemopreventive intervention studies. In this article we highlight the histopathological and molecular features and describe the principal genetic and epigenetic alterations and inflammatory pathways involved in carcinogenesis in AOM/DSS–treated mice; we also present a general overview of recent experimental applications and preclinical testing of novel therapeutics in the AOM/DSS model. PMID:21483655

Role of Anthocyanin-enriched Purple-fleshed Sweet Potato P40 in Colorectal Cancer Prevention

PubMed Central

Lim, Soyoung; Xu, Jianteng; Kim, Jaeyong; Chen, Tzu-Yu; Su, Xiaoyu; Standard, Joseph; Carey, Edward; Griffin, Jason; Herndon, Betty; Katz, Benjamin; Tomich, John; Wang, Weiqun

2013-01-01

Scope Anthocyanins, the natural pigments in plant foods, have been associated with cancer prevention. However, the content of anthocyanins in staple foods is typically low and the mechanisms by which they exert anti-cancer activity is not yet fully defined. Methods and results We selected an anthocyanin-enriched purple-fleshed sweet potato clone, P40, and investigated its potential anti-cancer effect in both in vitro cell culture and in vivo animal model. In addition to a high level of total phenolics and antioxidant capacity, P40 possesses a high content of anthocyanins at 7.5 mg/g dry matter. Treatment of human colonic SW480 cancer cells with P40 anthocyanin extracts at 0–40 μM of peonidin-3-glucoside equivalent resulted in a dose-dependent decrease in cell number due to cytostatic arrest of cell cycle at G1 phase but not cytotoxicity. Furthermore, dietary P40 at 10–30% significantly suppressed azoxymethane-induced formation of aberrant crypt foci in the colons of CF-1 mice in conjunction with, at least in part, a lesser proliferative PCNA and a greater apoptotic caspase-3 expression in the colon mucosal epithelial cells. Conclusion These observations, coupled with both in vitro and in vivo studies reported here, suggest anthocyanin-enriched sweet potato P40 may protect against colorectal cancer by inducing cell cycle arrest, anti-proliferative and apoptotic mechanisms. PMID:23784800

MET Signaling Mediates Intestinal Crypt-Villus Development, Regeneration, and Adenoma Formation and Is Promoted by Stem Cell CD44 Isoforms.

PubMed

Joosten, Sander P J; Zeilstra, Jurrit; van Andel, Harmen; Mijnals, R Clinton; Zaunbrecher, Joost; Duivenvoorden, Annet A M; van de Wetering, Marc; Clevers, Hans; Spaargaren, Marcel; Pals, Steven T

2017-10-01

Resistance of metastatic human colorectal cancer cells to drugs that block epidermal growth factor (EGF) receptor signaling could be caused by aberrant activity of other receptor tyrosine kinases, activating overlapping signaling pathways. One of these receptor tyrosine kinases could be MET, the receptor for hepatocyte growth factor (HGF). We investigated how MET signaling, and its interaction with CD44 (a putative MET coreceptor regulated by Wnt signaling and highly expressed by intestinal stem cells [ISCs] and adenomas) affects intestinal homeostasis, regeneration, and adenoma formation in mini-gut organoids and mice. We established organoid cultures from ISCs stimulated with HGF or EGF and assessed intestinal differentiation by immunohistochemistry. Mice with total epithelial disruption of MET (Ah Cre /Met fl/fl /LacZ) or ISC-specific disruption of MET (Lgr5 Creert2 /Met fl/fl /LacZ) and control mice (Ah Cre /Met +/+ /LacZ, Lgr5 Creert2 /Met +/+ /LacZ) were exposed to 10 Gy total body irradiation; intestinal tissues were collected, and homeostasis and regeneration were assessed by immunohistochemistry. We investigated adenoma organoid expansion stimulated by HGF or EGF using adenomas derived from Lgr5 Creert2 /Met fl/fl /Apc fl/fl and Lgr5 Creert2 /Met +/+ /Apc fl/fl mice. The same mice were evaluated for adenoma prevalence and size. We also quantified adenomas in Ah Cre /Met fl/fl /Apc fl/+ mice compared with Ah Cre /Met +/+ /Apc fl/+ control mice. We studied expansion of organoids generated from crypts and adenomas, stimulated by HGF or EGF, that were derived from mice expressing different CD44 splice variants (Cd44 +/+ , Cd44 -/- , Cd44 s/s , or Cd44 v4-10/v4-10 mice). Crypts incubated with EGF or HGF expanded into self-organizing mini-guts with similar levels of efficacy and contained all differentiated cell lineages. MET-deficient mice did not have defects in intestinal homeostasis. Total body irradiation reduced numbers of proliferating crypts in Ah Cre /Met fl/fl /LacZ mice. Lgr5 Creert2 /Met fl/fl /LacZ mice had impaired regeneration of MET-deficient ISCs. Adenoma organoids stimulated with EGF or HGF expanded to almost twice the size of nonstimulated organoids. MET-deficient adenoma organoids did not respond to HGF stimulation, but did respond to EGF. ISC-specific disruption of Met (Lgr5 Creert2 /Met fl/fl /Apc fl/fl mice) caused a twofold increase in apoptosis in microadenomas, resulting in an approximately 50% reduction of microadenoma numbers and significantly reduced average adenoma size. Total epithelial disruption of Met (Ah Cre /Met fl/fl /Apc fl/+ mice) resulted in an approximate 50% reduction in (micro)adenoma numbers. Intestinal crypts from Cd44 -/- mice did not expand to the same extent as crypts from Cd44 +/+ mice on stimulation with HGF, but had the same response to EGF. The negative effect on HGF-mediated growth was overcome by expression of CD44v4-10, but not by CD44s. Similarly, HGF-mediated expansion of adenoma organoids required CD44v4-10. In studies of intestinal organoid cultures and mice with inducible deletion of MET, we found HGF receptor signaling to regulate intestinal homeostasis and regeneration, as well as adenoma formation. These activities of MET are promoted by the stem cell CD44 isoform CD44v4-10. Our findings provide rationale for targeting signaling via MET and CD44 during anti-EGF receptor therapy of patients with colorectal cancer or in patients resistant to EGF receptor inhibitors. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

Protective effect of agaro-oligosaccharides on gut dysbiosis and colon tumorigenesis in high-fat diet-fed mice.

PubMed

Higashimura, Yasuki; Naito, Yuji; Takagi, Tomohisa; Uchiyama, Kazuhiko; Mizushima, Katsura; Ushiroda, Chihiro; Ohnogi, Hiromu; Kudo, Yoko; Yasui, Madoka; Inui, Seina; Hisada, Takayoshi; Honda, Akira; Matsuzaki, Yasushi; Yoshikawa, Toshikazu

2016-03-15

High-fat diet (HFD)-induced alteration in the gut microbial composition, known as dysbiosis, is increasingly recognized as a major risk factor for various diseases, including colon cancer. This report describes a comprehensive investigation of the effect of agaro-oligosaccharides (AGO) on HFD-induced gut dysbiosis, including alterations in short-chain fatty acid contents and bile acid metabolism in mice. C57BL/6N mice were fed a control diet or HFD, with or without AGO. Terminal restriction fragment-length polymorphism (T-RFLP) analysis produced their fecal microbiota profiles. Profiles of cecal organic acids and serum bile acids were determined, respectively, using HPLC and liquid chromatography-tandem mass spectrometry systems. T-RFLP analyses showed that an HFD changed the gut microbiota significantly. Changes in the microbiota composition induced by an HFD were characterized by a decrease in the order Lactobacillales and by an increase in the Clostridium subcluster XIVa. These changes of the microbiota community generated by HFD treatment were suppressed by AGO supplementation. As supported by the data of the proportion of Lactobacillales order, the concentration of lactic acid increased in the HFD + AGO group. Data from the serum bile acid profile showed that the level of deoxycholic acid, a carcinogenic secondary bile acid produced by gut bacteria, was increased in HFD-receiving mice. The upregulation tended to be suppressed by AGO supplementation. Finally, results show that AGO supplementation suppressed the azoxymethane-induced generation of aberrant crypt foci in the colon derived from HFD-treated mice. Our results suggest that oral intake of AGO prevents HFD-induced gut dysbiosis, thereby inhibiting colon carcinogenesis. Copyright © 2016 the American Physiological Society.

Influence of a highly purified senna extract on colonic epithelium.

PubMed

van Gorkom, B A; Karrenbeld, A; van Der Sluis, T; Koudstaal, J; de Vries, E G; Kleibeuker, J H

2000-01-01

Chronic use of sennoside laxatives often causes pseudomelanosis coli. A recent study suggested that pseudomelanosis coli is associated with an increased colorectal cancer risk. A single high dose of highly purified senna extract increased proliferation rate and reduced crypt length in the sigmoid colon compared to historical controls. To evaluate in a controlled study the effects of highly purified senna extract on cell proliferation and crypt length in the entire colon and on p53 and bcl-2 expression. Addition of a senna extract to colonic lavage was studied in 184 consecutive outpatients. From 32 randomised patients, 15 with sennosides (Sen), 17 without (NSen), biopsies were taken. Proliferative activity was studied in 4 areas of the colon, using 5-bromo-2'-deoxyuridine labelling and immunohistochemistry (labelling index, LI). Expression of p53 and bcl-2 in the sigmoid colon was determined immunohistochemically. Crypts were shorter in Sen than in NSen in the transverse and sigmoid colon. LI was higher in Sen than in NSen in the entire colon. No difference in p53 expression was seen. Bcl-2 expression was higher in both groups when crypts were shorter and/or proliferation was increased. Sennosides induce acute massive cell loss probably by apoptosis, causing shorter crypts, and increased cell proliferation and inhibition of apoptosis to restore cellularity. These effects may reflect the mechanism for the suggested cancer-promoting effect of chronic sennoside use. Copyright 2000 S. Karger AG, Basel

Regional Differences in Stem and Transit Cell Proliferation and Apoptosis in the Terminal Ileum and Colon of Mice After 12 Gy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gandara, Ricardo M.C.; Mahida, Yashwant R., E-mail: yash.mahida@nottingham.ac.uk; Potten, Christopher S.

2012-03-01

Purpose: The intestinal epithelium has a high rate of cell turnover, which is regulated by stem cells located near the base of crypts. We aimed to investigate stem cell-dependent characteristics of cell proliferation, apoptosis, and crypt size in terminal ileum and different regions of the colon. Methods and Materials: Mice were studied under steady-state conditions and after radiation-induced stem cell apoptosis. Percentage of proliferating or apoptotic cells at a particular cell position (cp) along the crypt axis was expressed as labeling or apoptotic index. Results: Under steady-state conditions: crypt size was smallest in the ascending colon. In contrast to othermore » regions of the colon, the distribution profile of proliferating cells in ascending colon showed some similarity to that in the terminal ileum. Postirradiation: apoptotic cells were prominent at the bottom of the crypt of mid- and descending colon but in the ascending colon, they were seen with similar frequency from cp 1 to 4. During regeneration, a constant proliferative capacity was seen above Paneth cells in the terminal ileum. In the ascending (but not mid- or descending) colon, the profile of proliferating cells over the first 4 days after irradiation showed a similarity to that in the terminal ileum. Conclusions: Profiles of proliferating epithelial cells (under steady-state conditions and postirradiation) and apoptotic cells (postirradiation) suggest similarities in the location of stem cells in the ascending colon and terminal ileum.« less

A Hypothalamic Switch for REM and Non-REM Sleep.

PubMed

Chen, Kai-Siang; Xu, Min; Zhang, Zhe; Chang, Wei-Cheng; Gaj, Thomas; Schaffer, David V; Dan, Yang

2018-03-07

Rapid eye movement (REM) and non-REM (NREM) sleep are controlled by specific neuronal circuits. Here we show that galanin-expressing GABAergic neurons in the dorsomedial hypothalamus (DMH) comprise separate subpopulations with opposing effects on REM versus NREM sleep. Microendoscopic calcium imaging revealed diverse sleep-wake activity of DMH GABAergic neurons, but the galanin-expressing subset falls into two distinct groups, either selectively activated (REM-on) or suppressed (REM-off) during REM sleep. Retrogradely labeled, preoptic area (POA)-projecting galaninergic neurons are REM-off, whereas the raphe pallidus (RPA)-projecting neurons are primarily REM-on. Bidirectional optogenetic manipulations showed that the POA-projecting neurons promote NREM sleep and suppress REM sleep, while the RPA-projecting neurons have the opposite effects. Thus, REM/NREM switch is regulated antagonistically by DMH galaninergic neurons with intermingled cell bodies but distinct axon projections. Copyright © 2018 Elsevier Inc. All rights reserved.

Hyperphagia and obesity in OLETF rats lacking CCK-1 receptors

PubMed Central

Moran, Timothy H; Bi, Sheng

2006-01-01

The brain–gut peptide cholecystokinin (CCK) inhibits food intake following peripheral or site directed central administration. Peripheral exogenous CCK inhibits food intake by reducing the size and duration of a meal. Antagonist studies have demonstrated that the actions of the exogenous peptide mimic those of endogenous CCK. Antagonist administration results in increased meal size and meal duration. The feeding inhibitory actions of CCK are mediated through interactions with CCK-1 receptors. The recent identification of the Otsuka–Long–Evans–Tokushima Fatty (OLETF) rat as a spontaneous CCK-1 receptor knockout model has allowed a more comprehensive evaluation of the feeding actions of CCK. OLETF rats become obese and develop non-insulin dependent diabetes mellitus (NIDDM). Consistent with the absence of CCK-1 receptors, OLETF rats do not respond to exogenous CCK. OLETF rats are hyperphagic and their increased food intake is characterized by a large increase in meal size with a decrease in meal frequency that is not sufficient to compensate for the meal size increase. Deficits in meal size control are evident in OLETF rats as young as 2 days of age. OLETF obesity is secondary to the increased food intake. Pair feeding to amounts consumed by intact control rats normalizes body weight, body fat and elevated insulin and glucose levels. Hypothalamic arcuate nucleus peptide mRNA expression in OLETF rats is appropriate to their obesity and is normalized by pair feeding. In contrast, pair fed and young pre-obese OLETF rats have greatly elevated dorsomedial hypothalamic (DMH) neuropeptide Y (NPY) mRNA expression. Elevated DMH NPY in OLETF rats appears to be a consequence of the absence of CCK-1 receptors. In intact rats NPY and CCK-1 receptors colocalize to neurons within the compact subregion of the DMH and local CCK administration reduces food intake and decreases DMH NPY mRNA expression. We have proposed that the absence of DMH CCK-1 receptors significantly contributes to the OLETF's inability to compensate for their meal size control deficit leading to their overall hyperphagia. Access to a running wheel and the resulting exercise normalizes food intake and body weight in OLETF rats. When given access to running wheels for 6 weeks shortly after weaning, OLETF rats do not gain weight to the same degree as sedentary OLETF rats and do not develop NIDDM. Exercise also prevents elevated levels of DMH NPY mRNA expression, suggesting that exercise exerts an alternative, non-CCK mediated, control on DMH NPY. The OLETF rat is a valuable model for characterizing actions of CCK in energy balance and has provided novel insights into interactions between exercise and food intake. PMID:16815799

Critical role of microbiota within cecal crypts on the regenerative capacity of the intestinal epithelium following surgical stress.

PubMed

Zaborin, Alexander; Krezalek, Monika; Hyoju, Sanjiv; Defazio, Jennifer R; Setia, Namrata; Belogortseva, Natalia; Bindokas, Vytautas P; Guo, Qiti; Zaborina, Olga; Alverdy, John C

2017-02-01

Cecal crypts represent a unique niche that are normally occupied by the commensal microbiota. Due to their density and close proximity to stem cells, microbiota within cecal crypts may modulate epithelial regeneration. Here we demonstrate that surgical stress, a process that invariably involves a short period of starvation, antibiotic exposure, and tissue injury, results in cecal crypt evacuation of their microbiota. Crypts devoid of their microbiota display pathophysiological features characterized by abnormal stem cell activation as judged by leucine-rich repeat-containing G protein-coupled receptor 5 (Lgr5) staining, expansion of the proliferative zone toward the tips of the crypts, and an increase in apoptosis. In addition, crypts devoid of their microbiota display loss of their regenerative capacity as assessed by their ability to form organoids ex vivo. When a four-member human pathogen community isolated from the stool of a critically ill patient is introduced into the cecum of mice with empty crypts, crypts become occupied by the pathogens and further disruption of crypt homeostasis is observed. Fecal microbiota transplantation restores the cecal crypts' microbiota, normalizes homeostasis within crypts, and reestablishes crypt regenerative capacity. Taken together, these findings define an emerging role for the microbiota within cecal crypts to maintain epithelial cell homeostasis in a manner that may enhance recovery in response to the physiological stress imposed by the process of surgery. This study provides novel insight into the process by which surgical injury places the intestinal epithelium at risk for colonization by pathogenic microbes and impairment of its regenerative capacity via loss of its microbiota. We show that fecal transplant restores crypt homeostasis in association with repopulation of the microbiota within cecal crypts. Copyright © 2017 the American Physiological Society.

Dietary milk fat globule membrane reduces the incidence of aberrant crypt foci in Fischer-344 rats.

PubMed

Snow, Dallin R; Jimenez-Flores, Rafael; Ward, Robert E; Cambell, Jesse; Young, Michael J; Nemere, Ilka; Hintze, Korry J

2010-02-24

Milk fat globule membrane (MFGM) is a biopolymer composed primarily of membrane proteins and lipids that surround the fat globules in milk. Although it is considered to have potential as a bioactive ingredient, few feeding studies have been conducted to measure its potential benefits. The aim of this investigation was to determine if dietary MFGM confers protection against colon carcinogenesis compared to diets containing corn oil (CO) or anhydrous milk fat (AMF). Male, weanling Fischer-344 rats were randomly assigned to one of three dietary treatments that differed only in the fat source: (1) AIN-76A diet, corn oil; (2) AIN-76A diet, AMF; and (3) AIN-76A diet, 50% MFGM, 50% AMF. Each diet contained 50 g/kg diet of fat. With the exception of the fat source, diets were formulated to be identical in macro and micro nutrient content. Animals were injected with 1,2-dimethylhydrazine once per week at weeks 3 and 4, and fed experimental diets for a total of 13 weeks. Over the course of the study dietary treatment did not affect food consumption, weight gain or body composition. After 13 weeks animals were sacrificed, colons were removed and aberrant crypt foci (ACF) were counted by microscopy. Rats fed the MFGM diet (n = 16) had significantly fewer ACF (20.9 +/- 5.7) compared to rats fed corn oil (n = 17) or AMF (n = 16) diets (31.3 +/- 9.5 and 29.8 +/- 11.4 respectively; P < 0.05). Gene expression analysis of colonic mucosa did not reveal differential expression of candidate colon cancer genes, and the sphingolipid profile of the colonic mucosa was not affected by diet. While there were notable and significant differences in plasma and red blood cell lipids, there was no relationship to the cancer protection. These results support previous findings that dietary sphingolipids are protective against colon carcinogenesis yet extend this finding to MFGM, a milk fat fraction available as a food ingredient.

Complete genome sequence of Lactobacillus salivarius Ren, a probiotic strain with anti-tumor activity.

PubMed

Sun, Erna; Ren, Fazheng; Liu, Songling; Ge, Shaoyang; Zhang, Ming; Guo, Huiyuan; Jiang, Lu; Zhang, Hao; Zhao, Liang

2015-09-20

Lactobacillus salivarius Ren (LsR) (CGMCC No. 3606) is a probiotic strain that was isolated from the feces of a healthy centenarian living in Bama, Guangxi, China. Previous studies have shown that this strain decreases 4-nitroquinoline 1-oxide (4-NQO)-induced genotoxicity in vitro. It also suppresses 4-NQO-induced oral carcinogenesis and 1,2-dimethylhydrazine (DMH)-induced colorectal carcinogenesis, and therefore may be used as an adjuvant therapeutic agent for cancer. Here, we report the complete genome sequence of LsR that consists of a circular chromosome of 1751,565 bp and two plasmids (pR1, 176,951 bp; pR2, 49,848 bp). Copyright © 2015 Elsevier B.V. All rights reserved.

The PI3K/Akt pathway in colitis associated colon cancer and its chemoprevention with celecoxib, a Cox-2 selective inhibitor.

PubMed

Setia, Shruti; Nehru, Bimla; Sanyal, Sankar Nath

2014-07-01

Oncogenesis and angiogenesis are the two major pathways involved in tumorigenesis. Oncogenesis involves the PI3K/Akt and Wnt/β-catenin pathways, both of which are upregulated in several types of cancers. We established animal model of ulcerative colitis, colon cancer and colitis associated colon cancer by the incorporation of dextran sufate sodium (DSS) and dimethyl hydrazine (DMH), alone as well as in combination. Apart from the gross morphological analysis, we presently explored the role of various components of the oncogenic pathways, including PI3K, p-Akt, PTEN, PDK1, mTOR, GSK-3β, Wnt and β-catenin and found the elevated levels of these proteins, except the tumor suppressors PTEN and GSK-3β, whose levels were downregulated in both inflammatory and carcinogenic conditions. We also studied the protein expression of some major angiogenic agents, such as Vegf, MMP-2, MMP-9 and iNOS. The angiogenic pathway was also upregulated presently in the DSS, DMH and DSS+DMH groups. Also, the reactive oxygen and nitrogen species, which lead to oxidative stress, were found to be elevated in these groups. All these effects were brought towards normal by the co-administration of celecoxib, a second generation non-steroidal anti-inflammatory drug (NSAID), with DSS, DMH and their combinatorial group. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Bright metal coatings from sustainable electrolytes: the effect of molecular additives on electrodeposition of nickel from a deep eutectic solvent.

PubMed

Abbott, Andrew P; Ballantyne, Andrew; Harris, Robert C; Juma, Jamil A; Ryder, Karl S

2017-01-25

Organic and inorganic additives are often added to nickel electroplating solutions to improve surface finish, reduce roughness and promote uniform surface morphology of the coatings. Such additives are usually small molecules and often referred to as brighteners or levellers. However, there have been limited investigations into the effect of such additives on electrodeposition from ionic liquids (ILs) and deep eutectic solvents (DESs). Here we study the effect of four additives on electrolytic nickel plating from an ethyleneglycol based DES; these are nicotinic acid (NA), methylnicotinate (MN), 5,5-dimethylhydantoin (DMH) and boric acid (BA). The additives show limited influence on the bulk Ni(ii) speciation but have significant influence on the electrochemical behaviour of Ni deposition. Small concentrations (ca. 15 mM) of NA and MN show inhibition of Ni(ii) reduction whereas high concentrations of DMH and BA are required for a modest difference in behaviour from the additive free system. NA and MN also show that they significantly alter the nucleation and growth mechanism when compared to the additive free system and those with DMH and BA. Each of the additive systems had the effect of producing brighter and flatter bulk electrodeposits with increased coating hardness but XRD shows that NA and MN direct crystal growth to the [111] orientation whereas DMH and BA direct crystal growth to the [220] orientation.

The influence of androgens, anti-androgens, and castration on cell proliferation in the jejunal and colonic crypt epithelia, and in dimethylhydrazine-induced adenocarcinoma of rat colon.

PubMed

Tutton, P J; Barkla, D H

1982-01-01

Androgenic hormones have previously been shown to promote cell proliferation in the small intestine of rat and androgen receptors have been demonstrated in carcinomata of the large intestine of rat. In this study the influence of testosterone and of castration on epithelial cell proliferation in the small intestine, the large intestine and in dimethylhydrazine-induced colonic tumours is compared. Cell proliferation in the small intestine and in colonic tumours was accelerated by testosterone treatment, and cell proliferation in colonic tumours, but not in the small intestine, was retarded following castration. Cell proliferation in colonic tumours was also inhibited by the anti-androgenic drug, Flutamide. Testosterone and castration each failed to influence cell proliferation in the colonic crypt epithelium of both normal and carcinogen-treated animals.

Sodium Selenite Radiosensitizes Hormone-Refractory Prostate Cancer Xenograft Tumors but Not Intestinal Crypt Cells In Vivo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tian Junqiang; Ning Shouchen; Knox, Susan J., E-mail: sknox@stanford.ed

Purpose: We have previously shown that sodium selenite (SSE) increases radiation-induced cell killing of human prostate carcinoma cells in vitro. In this study we further evaluated the in vivo radiosensitizing effect of SSE in prostate cancer xenograft tumors and normal radiosensitive intestinal crypt cells. Methods and Materials: Immunodeficient (SCID) mice with hormone-independent LAPC-4 (HI-LAPC-4) and PC-3 xenograft tumors (approximately 200 mm{sup 3}) were divided into four groups: control (untreated), radiation therapy (XRT, local irradiation), SSE (2 mg/kg, intraperitoneally, 3 times/week), and XRT plus SSE. The XRT was given at the beginning of the regimen as a single dose of 5more » Gy for HI-LAPC-4 tumors and a single dose of 7 Gy followed by a fractional dose of 3 Gy/d for 5 days for PC-3 tumors. The tumor volume was measured 3 times per week. The radiosensitizing effect of SSE on normal intestinal epithelial cells was assessed by use of a crypt cell microcolony assay. Results: In the efficacy study, SSE alone significantly inhibited the tumor growth in HI-LAPC-4 tumors but not PC-3 tumors. Sodium selenite significantly enhanced the XRT-induced tumor growth inhibition in both HI-LAPC-4 and PC-3 tumors. In the toxicity study, SSE did not affect the intestinal crypt cell survival either alone or in combination with XRT. Conclusions: Sodium selenite significantly enhances the effect of radiation on well-established hormone-independent prostate tumors and does not sensitize the intestinal epithelial cells to radiation. These results suggest that SSE may increase the therapeutic index of XRT for the treatment of prostate cancer.« less

GM-CSF produced by non-hematopoietic cells is required for early epithelial cell proliferation and repair of injured colonic mucosa1,2

PubMed Central

Egea, Laia; McAllister, Christopher S.; Lakhdari, Omar; Minev, Ivelina; Shenouda, Steve; Kagnoff, Martin F.

2012-01-01

GM-CSF is a growth factor that promotes the survival and activation of macrophages and granulocytes, and dendritic cell (DC) differentiation and survival in vitro. The mechanism by which exogenous GM-CSF ameliorates the severity of Crohn’s disease in humans and colitis in murine models has been considered mainly to reflect its activity on myeloid cells. We used GM-CSF deficient (GM-CSF−/−) mice to probe the functional role of endogenous host-produced GM-CSF in a colitis model induced after injury to the colon epithelium. Dextran sodium sulfate (DSS) at doses that resulted in little epithelial damage and mucosal ulceration in wild type (WT) mice resulted in marked colon ulceration and delayed ulcer healing in GM-CSF−/− mice. Colon crypt epithelial cell proliferation in vivo was significantly decreased in GM-CSF−/− mice at early times after DSS injury. This was paralleled by decreased expression of crypt epithelial cell genes involved in cell cycle, proliferation, and wound healing. Decreased crypt cell proliferation and delayed ulcer healing in GM-CSF−/− mice were rescued by exogenous GM-CSF, indicating the lack of a developmental abnormality in the epithelial cell proliferative response in those mice. Non-hematopoietic cells and not myeloid cells produced the GM-CSF important for colon epithelial proliferation after DSS-induced injury as revealed by bone marrow chimera and DC depletion experiments, with colon epithelial cells being the cellular source of GM-CSF. Endogenous epithelial cell produced GM-CSF has a novel non-redundant role in facilitating epithelial cell proliferation and ulcer healing in response to injury of the colon crypt epithelium. PMID:23325885

Proteomic changes during intestinal cell maturation in vivo

PubMed Central

Chang, Jinsook; Chance, Mark R.; Nicholas, Courtney; Ahmed, Naseem; Guilmeau, Sandra; Flandez, Marta; Wang, Donghai; Byun, Do-Sun; Nasser, Shannon; Albanese, Joseph M.; Corner, Georgia A.; Heerdt, Barbara G.; Wilson, Andrew J.; Augenlicht, Leonard H.; Mariadason, John M.

2008-01-01

Intestinal epithelial cells undergo progressive cell maturation as they migrate along the crypt-villus axis. To determine molecular signatures that define this process, proteins differentially expressed between the crypt and villus were identified by 2D-DIGE and MALDI-MS. Forty-six differentially expressed proteins were identified, several of which were validated by immunohistochemistry. Proteins upregulated in the villus were enriched for those involved in brush border assembly and lipid uptake, established features of differentiated intestinal epithelial cells. Multiple proteins involved in glycolysis were also upregulated in the villus, suggesting increased glycolysis is a feature of intestinal cell differentiation. Conversely, proteins involved in nucleotide metabolism, and protein processing and folding were increased in the crypt, consistent with functions associated with cell proliferation. Three novel paneth cell markers, AGR2, HSPA5 and RRBP1 were also identified. Notably, significant correlation was observed between overall proteomic changes and corresponding gene expression changes along the crypt-villus axis, indicating intestinal cell maturation is primarily regulated at the transcriptional level. This proteomic profiling analysis identified several novel proteins and functional processes differentially induced during intestinal cell maturation in vivo. Integration of proteomic, immunohistochemical, and parallel gene expression datasets demonstrate the coordinated manner in which intestinal cell maturation is regulated. PMID:18824147

Mask-induced aberration in EUV lithography

NASA Astrophysics Data System (ADS)

Nakajima, Yumi; Sato, Takashi; Inanami, Ryoichi; Nakasugi, Tetsuro; Higashiki, Tatsuhiko

2009-04-01

We estimated aberrations using Zernike sensitivity analysis. We found the difference of the tolerated aberration with line direction for illumination. The tolerated aberration of perpendicular line for illumination is much smaller than that of parallel line. We consider this difference to be attributable to the mask 3D effect. We call it mask-induced aberration. In the case of the perpendicular line for illumination, there was a difference in CD between right line and left line without aberration. In this report, we discuss the possibility of pattern formation in NA 0.25 generation EUV lithography tool. In perpendicular pattern for EUV light, the dominant part of aberration is mask-induced aberration. In EUV lithography, pattern correction based on the mask topography effect will be more important.

Chemoprevention studies of the flavonoids quercetin and rutin in normal and azoxymethane-treated mouse colon.

PubMed

Yang, K; Lamprecht, S A; Liu, Y; Shinozaki, H; Fan, K; Leung, D; Newmark, H; Steele, V E; Kelloff, G J; Lipkin, M

2000-09-01

In this study we investigated the chemopreventive effects of quercetin and rutin when added to standard AIN-76A diet and fed to normal and azoxymethane (AOM)-treated mice. Early changes in colonic mucosa were analyzed, including colonic cell proliferation, apoptotic cell death, cyclin D(1) expression and focal areas of dysplasia (FAD). The findings show that the number of colonic epithelial cells per crypt column increased (P: < 0.01) in each normal mouse group fed the flavonoids; AOM administration increased colonic crypt cell proliferation and resulted in a marked rise of bromodeoxyuridine-labeled cells in the lower proliferative zone of the crypt. Both supplementary dietary quercetin and rutin increased the apoptotic index and caused a redistribution of apoptotic cells along the crypt axis in normal mice fed a standard AIN-76A diet. The number of apoptotic cells/column and apoptotic indices markedly increased (P: < 0.01) in the AOM-treated group compared with untreated animals; apoptotic cells expanded throughout the colonic crypts after flavonoid supplementation and AOM administration. Positive cyclin D(1) expression was detected in mice on diets supplemented either with quercetin (P: < 0.01) or rutin (P: < 0.05). AOM administration resulted in the formation of FAD. Both the number of mice exhibiting FAD and the total numer of FAD observed were significantly reduced (P: < 0.01) in AOM-treated animals fed flavonoids compared with mice maintained on the standard AIN-76A diet. Surprisingly, however, quercetin alone was able to induce FAD in 22% of normal mice fed the standard AIN-76A diet.

Influence of prostaglandin analogues on epithelial cell proliferation and xenograft growth.

PubMed Central

Tutton, P. J.; Barkla, D. H.

1980-01-01

The influence of two prostaglandin (PG) analogues, 16,16-dimethyl PG E2 and 16,16-dimethyl PG F2 alpha and of the cyclo-oxygenase inhibitor, flurbiprofen, on epithelial cell proliferation was assessed using a stathmokinetic technique. The epithelia examined were those of the jejunal crypts, the colonic crypts and that of dimethylhydrazine-induced adenocarcinomas of rat colon. The influence of the two prostaglandin analogues, and of flurbiprofen, on the growth of a human colorectal tumour propagated as xenografts in immune-deprived mice was also assessed. The PG E2 analogue transiently inhibited xenograft growth, but was without effect on the mitotic rate in the rat tissues. The PG F2 alpha analogue was also found to inhibit xenograft growth but, unlike the PG E2 analogue, it was found to be a strong inhibitor of cell proliferation in rat colonic tumours, and an accelerator of proliferation in jejunal-crypt cells. The only statistically significant effect of flurbiprofen was to accelerate cell division in the rat colonic tumours. PMID:7362778

Influence of prostaglandin analogues on epithelial cell proliferation and xenograft growth.

PubMed

Tutton, P J; Barkla, D H

1980-01-01

The influence of two prostaglandin (PG) analogues, 16,16-dimethyl PG E2 and 16,16-dimethyl PG F2 alpha and of the cyclo-oxygenase inhibitor, flurbiprofen, on epithelial cell proliferation was assessed using a stathmokinetic technique. The epithelia examined were those of the jejunal crypts, the colonic crypts and that of dimethylhydrazine-induced adenocarcinomas of rat colon. The influence of the two prostaglandin analogues, and of flurbiprofen, on the growth of a human colorectal tumour propagated as xenografts in immune-deprived mice was also assessed. The PG E2 analogue transiently inhibited xenograft growth, but was without effect on the mitotic rate in the rat tissues. The PG F2 alpha analogue was also found to inhibit xenograft growth but, unlike the PG E2 analogue, it was found to be a strong inhibitor of cell proliferation in rat colonic tumours, and an accelerator of proliferation in jejunal-crypt cells. The only statistically significant effect of flurbiprofen was to accelerate cell division in the rat colonic tumours.

Sources of the monochromatic aberrations induced in human eyes after laser refractive surgery

NASA Astrophysics Data System (ADS)

Porter, Jason

Laser in-situ keratomileusis (LASIK) procedures correct the eye's defocus and astigmatism but also introduce higher order monochromatic aberrations. Little is known about the origins of these induced aberrations. The advent of wavefront sensor technology has made it possible to measure accurately and quickly the aberrations of normal and postoperative LASIK eyes. The goal of this thesis was to exploit this technology to better understand some of the potential mechanisms by which aberrations could be introduced during LASIK. A first step towards investigating these sources was to characterize the aberration changes in post-LASIK eyes. Higher order rms wavefront error increased after conventional and customized LASIK surgery. On average, spherical aberration approximately doubled, and significant changes in vertical and horizontal coma were observed. We examined two sources of postoperative aberrations: the creation of a microkeratome flap and the subsequent laser ablation. Higher order rms increased slightly and there was a wide variation in the response of individual Zernike modes after cutting a flap. The majority of induced spherical aberration was due to the laser ablation and not the flap-cut. Aberrations are also induced by static and dynamic decentrations of the patient's pupil. We found that ablations were typically decentered in the superotemporal direction due to shifts in pupil center location between aberration measurement (dilated) and surgical (undilated) conditions in customized LASIK eyes. There was a weak correlation between the horizontal coma theoretically induced by this offset and that measured postoperatively. Finally, dynamic eye movements during the procedure induce higher order aberrations. We found that the most problematic decentrations during LASIK are relatively slow drifts in eye position. An eye-tracking system with a 2-Hz closed-loop bandwidth could compensate for most eye movements during LASIK. One solution for reducing the aberrations induced by static and dynamic shifts in pupil center location is to reference the aberration measurement and treatment with respect to fixed features on the eye. Several other sources of aberration induction in LASIK, such as the efficiency of laser pulses striking the cornea perpendicularly versus obliquely, must still be investigated to optimize postoperative optical quality after LASIK.

Post-irradiation somatic mutation and clonal stabilisation time in the human colon.

PubMed Central

Campbell, F; Williams, G T; Appleton, M A; Dixon, M F; Harris, M; Williams, E D

1996-01-01

BACKGROUND: Colorectal crypts are clonal units in which somatic mutation of marker genes in stem cells leads to crypt restricted phenotypic conversion initially involving part of the crypt, later the whole crypt. Studies in mice show that the time taken for the great majority of mutated crypts to be completely converted, the clonal stabilisation time, is four weeks in the colon and 21 weeks in the ileum. Differences in the clonal stabilisation time between tissues and species are thought to reflect differences in stem cell organisation and crypt kinetics. AIM: To study the clonal stabilisation time in the human colorectum. METHODS: Stem cell mutation can lead to crypt restricted loss of O-acetylation of sialomucins in subjects heterozygous for O-acetyltransferase gene activity. mPAS histochemistry was used to visualise and quantify crypts partially or wholly involved by the mutant phenotype in 21 informative cases who had undergone colectomy up to 34 years after radiotherapy. RESULTS: Radiotherapy was followed by a considerable increase in the discordant crypt frequency that remained significantly increased for many years. The proportion of discordant crypts showing partial involvement was initially high but fell to normal levels about 12 months after irradiation. CONCLUSIONS: Crypts wholly involved by a mutant phenotype are stable and persistent while partially involved crypts are transient. The clonal stabilisation time is approximately one year in the human colon compared with four weeks in the mouse. The most likely reason for this is a difference in the number of stem cells in a crypt stem cell niche, although differences in stem cell cycle time and crypt fission may also contribute. These findings are of relevance to colorectal gene therapy and carcinogenesis in stem cell systems. PMID:8944567

Cannabinoid agonists and antagonists modulate lithium-induced conditioned gaping in rats.

PubMed

Parker, Linda A; Mechoulam, Raphael

2003-01-01

Considerable evidence indicates that conditioned gaping in rats reflects nausea in this species that does not vomit. A series of experiments evaluated the potential of psychoactive cannabinoid agonists, delta-9-THC and HU-210, and non-psychoactive cannabinoids, Cannabidiol (CBD) and its dimethylheptyl homolog (CBD-dmh), to interfere with the establishment and the expression of conditioned gaping in rats. All agents attenuated both the establishment and the expression of conditioned gaping. Furthermore, the CB1 antagonist, SR-141716, reversed the suppressive effect of HU-210 on conditioned gaping. Finally, SR-141716 potentiated lithium-induced conditioned gaping, suggesting that the endogenous cannabinoid system plays a role in the control of nausea.

Anticarcinogenic efficacy of phytic acid extracted from rice bran on azoxymethane-induced colon carcinogenesis in rats.

PubMed

Norazalina, S; Norhaizan, M E; Hairuszah, I; Norashareena, M S

2010-05-01

This study is carried out to determine the potential of phytic acid extracted from rice bran in the suppression of colon carcinogenesis induced by azoxymethane (AOM) in rats. Seventy-two male Sprague-Dawley rats were divided into 6 groups with 12 rats in each group. The intended rats for cancer treatment received two intraperitoneal injections of AOM in saline (15mg/kg bodyweight) over a 2-week period. The treatments of phytic acid were given in two concentrations: 0.2% (w/v) and 0.5% (w/v) during the post-initiation phase of carcinogenesis phase via drinking water. The colons of the animals were analyzed for detection and quantification of aberrant crypt foci (ACF) after 8 weeks of treatment. The finding showed treatment with 0.2% (w/v) extract phytic acid (EPA) gave the greatest reduction in the formation of ACF. In addition, phytic acid significantly suppressed the number of ACF in the distal, middle and proximal colon as compared to AOM alone (p<0.05). For the histological classification of ACF, treatment with 0.5% (w/v) commercial phytic acid (CPA) had the highest percentage (71%) of non-dysplastic ACF followed by treatment with 0.2% (w/v) EPA (61%). Administration of phytic acid also reduced the incidence and multiplicity of total tumors even though there were no significant differences between groups. In conclusion, this study found the potential value of phytic acid extracted from rice bran in reducing colon cancer risk in rats.

Chemopreventive and Antioxidant Effect of Polyphenol Free Spirulina maxima and Its Hydrolyzed Protein Content: Investigation on Azoxymethane Treated Mice.

PubMed

Martínez-Palma, Nikte Y; Dávila-Ortiz, Gloria; Jiménez-Martínez, Cristian; Madrigal-Bujaidar, Eduardo; Álvarez-González, Isela

2017-07-01

Spirulina maxima (Sm) is known to have nutritive value as well as a number of potentially useful biomedical properties. The initial purpose of this report was to evaluate the inhibitory effect of the alga (without its polyphenol content), on the induction of azoxymethane (AOM)-induced colon aberrant crypts (AC) in mouse. Besides, we hydrolyzed the protein content of such mixture. Our second aim was to determine the inhibitory potential of this last plant mixture on the AOM-induced colon AC in mouse. Moreover, we also determined the effect of the two indicated Sm samples on the oxidative damage caused by AOM in the colon and liver of treated mice. The experiment lasted 5 weeks. At the end, we registered the level of AC, nitric oxide, and the lipid and protein oxidation. Our results showed the following: (1) the carcinogen increased more than 18 times the amount of the AC found in the control group. (2) On the contrary, the two tested mixtures of Sm produced a significant reduction over this damage (about 45%). (3) The two tested Sm mixtures were generally able to reduce the oxidative stress markers although with variable effects which go from 59% to 100% with respect to the control mice. Therefore, the present report established that the tested Sm fractions have mouse colon anticarcinogenic potential, partially related with their antioxidant capacity. Our report also suggested the need to further evaluate specific Sm chemicals as chemopreventive agents.

Multi-scale modeling of APC and [Formula: see text]-catenin regulation in the human colonic crypt.

PubMed

Emerick, Brooks; Schleiniger, Gilberto; Boman, Bruce M

2018-06-01

Stem cell renewal and differentiation in the human colonic crypt are linked to the [Formula: see text]-catenin pathway. The spatial balance of Wnt factors in proliferative cells within the crypt maintain an appropriate level of cellular reproduction needed for normal crypt homeostasis. Mutational events at the gene level are responsible for deregulating the balance of Wnt factors along the crypt, causing an overpopulation of proliferative cells, a loss of structure of the crypt domain, and the initiation of colorectal carcinomas. We formulate a PDE model describing cell movement and reproduction in a static crypt domain. We consider a single cell population whose proliferative capabilities are determined by stemness, a quantity defined by intracellular levels of adenomatous polyposis coli (APC) scaffold protein and [Formula: see text]-catenin. We fit APC regulation parameters to biological data that describe normal protein gradients in the crypt. We also fit cell movement and protein flux parameters to normal crypt characteristics such as renewal time, total cell count, and proportion of proliferating cells. The model is used to investigate abnormal crypt dynamics when subjected to a diminished APC gradient, a scenario synonymous to mutations in the APC gene. We find that a 25% decrease in APC synthesis leads to a fraction of 0.88 proliferative, which is reflective of normal-appearing FAP crypts. A 50% drop in APC activity yields a fully proliferative crypt showing a doubling of the level of stemness, which characterizes the initial stages of colorectal cancer development. A sensitivity analysis of APC regulation parameters shows the perturbation of factors that is required to restore crypt dynamics to normal in the case of APC mutations.

Correcting spherical aberrations induced by an unknown medium through determination of its refractive index and thickness.

PubMed

Iwaniuk, Daniel; Rastogi, Pramod; Hack, Erwin

2011-09-26

In imaging and focusing applications, spherical aberration induces axial broadening of the point spread function (PSF). A transparent medium between lens and object of interest induces spherical aberration. We propose a method that first obtains both the physical thickness and the refractive index of the aberration inducing medium in situ by measuring the induced focal shifts for paraxial and large angle rays. Then, the fourth order angle dependence of the optical path difference inside the medium is used to correct the spherical aberration using a phase-only spatial light modulator. The obtained measurement accuracy of 3% is sufficient for a complete compensation as demonstrated in a model microscope with NA 0.3 with glass plate induced axial broadening of the PSF by a factor of 5. © 2011 Optical Society of America

Sperm storage in the human cervix: a quantitative study.

PubMed

Insler, V; Glezerman, M; Zeidel, L; Bernstein, D; Misgav, N

1980-03-01

Twenty-five women scheduled for hysterectomy for nonmalignant disease participated in the study. Sperm storage in endocervical crypts was examined in three groups of patients: nine women pretreated with estrogen and inseminated with normal semen, nine women pretreated with gestagen and inseminated with normal semen, and seven women pretreated with estrogen and inseminated with abnormal semen. The number of crypts containing spermatozoa (colonized crypts) and the sperm density per crypt were examined in serially sectioned cervices. In estrogen-pretreated cervices both the percentage of colonized crypts and the sperm density were significantly higher than in gestagen-pretreated cervices. Large and giant crypts proved to be the main storage facility for spermatozoa. The localization of crypts along the endocervical canal did not influence sperm storage. The quality of semen appeared to be of critical importance to sperm storage. The percentage of colonized crypts and sperm density were severly reduced in patients inseminated with abnormal semen.

The chemopreventive action of bromelain, from pineapple stem (Ananas comosus L.), on colon carcinogenesis is related to antiproliferative and proapoptotic effects.

PubMed

Romano, Barbara; Fasolino, Ines; Pagano, Ester; Capasso, Raffaele; Pace, Simona; De Rosa, Giuseppe; Milic, Natasa; Orlando, Pierangelo; Izzo, Angelo A; Borrelli, Francesca

2014-03-01

Colorectal cancer is an important health problem across the world. Here, we investigated the possible antiproliferative/proapoptotic effects of bromelain (from the pineapple stem Ananas comosus L., family Bromeliaceae) in a human colorectal carcinoma cell line and its potential chemopreventive effect in a murine model of colon cancer. Proliferation and apoptosis were evaluated in human colon adenocarcinoma (Caco-2) cells by the (3) H-thymidine incorporation assay and caspase 3/7 activity measurement, respectively. Extracellular signal-related kinase (ERK) and Akt expression were evaluated by Western blot analysis, reactive oxygen species production by a fluorimetric method. In vivo, bromelain was evaluated using the azoxymethane murine model of colon carcinogenesis. Bromelain reduced cell proliferation and promoted apoptosis in Caco-2 cells. The effect of bromelain was associated to downregulation of pERK1/2/total, ERK, and pAkt/Akt expression as well as to reduction of reactive oxygen species production. In vivo, bromelain reduced the development of aberrant crypt foci, polyps, and tumors induced by azoxymethane. Bromelain exerts antiproliferative and proapoptotic effects in colorectal carcinoma cells and chemopreventive actions in colon carcinogenesis in vivo. Bromelain-containing foods and/or bromelain itself may represent good candidates for colorectal cancer chemoprevention. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Generation, Characterization and Application of Antibodies Directed against HERV-H Gag Protein in Colorectal Samples.

PubMed

Mullins, Christina S; Hühns, Maja; Krohn, Mathias; Peters, Sven; Cheynet, Valérie; Oriol, Guy; Guillotte, Michèle; Ducrot, Sandrine; Mallet, François; Linnebacher, Michael

2016-01-01

A substantial part of the human genome originates from transposable elements, remnants of ancient retroviral infections. Roughly 8% of the human genome consists of about 400,000 LTR elements including human endogenous retrovirus (HERV) sequences. Mainly, the interplay between epigenetic and post-transcriptional mechanisms is thought to silence HERV expression in most physiological contexts. Interestingly, aberrant reactivation of several HERV-H loci appears specific to colorectal carcinoma (CRC). The expression of HERV-H Gag proteins (Gag-H) was assessed using novel monoclonal mouse anti Gag-H antibodies. In a flow cytometry screen four antibody clones were tested on a panel of primary CRC cell lines and the most well performing ones were subsequently validated in western blot analysis. Finally, Gag-H protein expression was analyzed by immune histology on cell line cytospins and on clinical samples. There, we found a heterogeneous staining pattern with no background staining of endothelial, stromal and infiltrating immune cells but diffuse staining of the cytoplasm for positive tumor and normal crypt cells of the colonic epithelium. Taken together, the Gag-H antibody clone(s) present a valuable tool for staining of cells with colonic origin and thus form the basis for future more detailed investigations. The observed Gag-H protein staining in colonic epithelium crypt cells demands profound analyses of a potential role for Gag-H in the normal physiology of the human gut.

Nanoproteomic analysis of extracellular receptor kinase-1/2 post-translational activation in microdissected human hyperplastic colon lesions.

PubMed

Drew, David A; Devers, Thomas; Horelik, Nicole; Yang, Shi; O'Brien, Michael; Wu, Rong; Rosenberg, Daniel W

2013-05-01

Oncogenic activation resulting in hyperproliferative lesions within the colonic mucosa has been identified in putative precancerous lesions, aberrant crypt foci (ACF). KRAS and BRAF mutation status was determined in 172 ACF identified in the colorectum of screening subjects by in situ high-definition, magnifying chromoendoscopy. Lesions were stratified according to histology (serrated vs. distended). Due to their limiting size, however, it was not technically feasible to examine downstream signaling consequences of these oncogenic mutations. We have combined ultraviolet-infrared (UV/IR) microdissection with an ultrasensitive nanofluidic proteomic immunoassay (NIA) to enable accurate quantification of posttranslational modifications to mitogen-activated protein kinase (MAPK) in total protein lysates isolated from hyperproliferative crypts and adjacent normal mucosa. Using this approach, levels of singly and dually (activated) phosphorylated isoforms of extracellular receptor kinase(ERK)-1 and ERK-2 were quantified in samples containing as little as 16 ng of total protein recovered from <200 cells. ERK activation is responsible for observed hyperplasia found in these early lesions, but is not directly dependent on KRAS and/or BRAF mutation status. This study describes the novel use of a sensitive nanofluidic platform to measure oncogene-driven proteomic changes in diminutive lesions and highlights the advantage of this approach over classical immunohistochemistry-based analyses. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Occult progression by Apc-deficient intestinal crypts as a target for chemoprevention

PubMed Central

Liskay, R.Michael

2014-01-01

Although Apc mutation is widely considered an initiating event in colorectal cancer, little is known about the earliest stages of tumorigenesis following sporadic Apc loss. Therefore, we have utilized a novel mouse model that facilitates the sporadic inactivation of Apc via frameshift reversion of Cre in single, isolated cells and subsequently tracks the fates of Apc-deficient intestinal cells. Our results suggest that consistent with Apc being a ‘gatekeeper’, loss of Apc early in life during intestinal growth leads to adenomas or increased crypt fission, manifested by fields of mutant but otherwise normal-appearing crypts. In contrast, Apc loss occurring later in life has minimal consequences, with mutant crypts being less prone to either increased crypt fission or adenoma formation. Using the stem cell-specific Lgr5-CreER mouse, we generated different sized fields of Apc-deficient crypts via independent recombination events and found that field size correlates with progression to adenoma. To evaluate this early stage prior to adenoma formation as a therapeutic target, we examined the chemopreventive effects of sulindac on Apc-deficient occult crypt fission. We found that sulindac treatment started early in life inhibits the morphologically occult spread of Apc-deficient crypts and thus reduces adenoma numbers. Taken together these results suggest that: (i) earlier Apc loss promotes increased crypt fission, (ii) a field of Apc-deficient crypts, which can form via occult crypt fission or independent neighboring events, is an important intermediate between loss of Apc and adenoma formation and (iii) normal-appearing Apc-deficient crypts are potential unappreciated targets for cancer screening and chemoprevention. PMID:23996931

Assessment of the mode of action underlying development of rodent small intestinal tumors following oral exposure to hexavalent chromium and relevance to humans

PubMed Central

Proctor, Deborah M.; Suh, Mina; Haws, Laurie C.; Kirman, Christopher R.; Harris, Mark A.

2013-01-01

Chronic exposure to high concentrations of hexavalent chromium (Cr(VI)) in drinking water causes intestinal adenomas and carcinomas in mice, but not in rats. Cr(VI) causes damage to intestinal villi and crypt hyperplasia in mice after only one week of exposure. After two years of exposure, intestinal damage and crypt hyperplasia are evident in mice (but not rats), as are intestinal tumors. Although Cr(VI) has genotoxic properties, these findings suggest that intestinal tumors in mice arise as a result of chronic mucosal injury. To better understand the mode of action (MOA) of Cr(VI) in the intestine, a 90-day drinking water study was conducted to collect histological, biochemical, toxicogenomic and pharmacokinetic data in intestinal tissues. Using MOA analyses and human relevance frameworks proposed by national and international regulatory agencies, the weight of evidence supports a cytotoxic MOA with the following key events: (a) absorption of Cr(VI) from the intestinal lumen, (b) toxicity to intestinal villi, (c) crypt regenerative hyperplasia and (d) clonal expansion of mutations within the crypt stem cells, resulting in late onset tumorigenesis. This article summarizes the data supporting each key event in the MOA, as well as data that argue against a mutagenic MOA for Cr(VI)-induced intestinal tumors. PMID:23445218

N-acetylcysteine improves redox status, mitochondrial dysfunction, mucin-depleted crypts and epithelial hyperplasia in dextran sulfate sodium-induced oxidative colitis in mice.

PubMed

Amrouche-Mekkioui, Ilhem; Djerdjouri, Bahia

2012-09-15

The effect of N-acetylcysteine (NAC), a pharmacological antioxidant was investigated in a murine model of chronic colitis. Male NMRI mice were given 5% dextran sulfate sodium (DSS) in drinking water for 5 days followed by 10 days of water, three times. Compared to control mice given water, DSS-treated mice displayed severe imbalanced redox status with decreased glutathione and catalase, but increased malondialdehyde, protein carbonyls, nitric oxide and myeloperoxidase levels, at days 35th (active colitis) and 45th (recovery period). It also resulted in mitochondrial dysfunction, mucosal ulcers, mucin-depleted crypts and epithelial cell apoptosis. Crypt abscesses and glandular hyperplasia occurred selectively in distal colon. NAC (150 mg/kg) given in drinking water for 45 days along with 3 DSS cycles improved the hallmarks of DSS-colitis. Interestingly, the moderate impact of NAC on lipids and proteins oxidation correlated with myeloperoxidase and nitric oxide levels.NAC as a mucoregulator and a thiol restoring agent is protective on oxidative crypt alterations, mucin depletion, epithelial cell hyperplasia and apoptosis. Taken together, our results highlight the role of NAC as a scavenger of phagocytes-derived reactive oxygen species in mice DDS-colitis, suggesting that a long term NAC diet might be beneficial in inflammatory bowel diseases and colorectal cancer. Copyright © 2012 Elsevier B.V. All rights reserved.

α-fetoprotein involvement during glucocorticoid-induced precocious maturation in rat colon

PubMed Central

Chen, Min; Sun, Peng; Liu, Xiao-Yan; Dong, Dan; Du, Jun; Gu, Luo; Ge, Ying-Bin

2011-01-01

AIM: To investigate the role of α-fetoprotein (AFP), a cancer-associated fetal glycoprotein, in glucocorticoid-induced precocious maturation in rat colon. METHODS: Colons from suckling Sprague-Dawley rats were used in this study. Corticosterone acetate at a dose of 100 μg/g body weight was given to normal pups on days 7, 9 and 11 after birth to induce hypercorticoidism. Control animals were injected with identical volumes of normal saline. Some rats receiving corticosterone 7 d after birth were also treated with mifepristone (RU38486), a glucocorticoid cytoplasm receptor antagonist to investigate the effects of glucocorticoids (GCs). The morphological changes of the crypt depth and villous height of the villous zone in colon were observed as indices of colon maturation. Expression levels of AFP in colons were detected by reverse transcriptase polymerase chain reaction and Western blotting. To identify the cellular localization of AFP in developing rat colons, double-immunofluorescent staining was performed using antibodies to specific mesenchymal cell marker and AFP. RESULTS: Corticosterone increased the crypt depth and villous height in the colon of 8- and 10-d-old rats with hypercorticoidism compared with that in the control animals (120% in 8-d-old rats and 118% in 10-d-old rats in villous height, P = 0.021; 145% in 8-d-old rats and 124% in 10-d-old rats in crypt depth, P = 0.017). These increases were accompanied by an increase of AFP expression in both mRNA and protein (2.5-folds in 8-d-old and 2.5-folds in 10-d-old rats higher than in control animals, P = 0.035; 1.8-folds in 8-d-old and 1.3-folds in 10-d-old rats higher than in control animals, P = 0.023). Increased crypt depth and villous height and increased expression of AFP in the colon of rats with hypercorticoidism were blocked by mifepristone. Both had positive staining for AFP or vimentin, and overlapped in mesenchymal cells at each tested colon. CONCLUSION: GCs promote the development of rat colon. AFP appears to be involved, in part, in mediating the effects of GCs in the developmental colon. PMID:21734804

Lactobacillus rhamnosus GG protects the intestinal epithelium from radiation injury through release of lipoteichoic acid, macrophage activation and the migration of mesenchymal stem cells.

PubMed

Riehl, Terrence E; Alvarado, David; Ee, Xueping; Zuckerman, Aaron; Foster, Lynn; Kapoor, Vaishali; Thotala, Dinesh; Ciorba, Matthew A; Stenson, William F

2018-06-22

Lactobacillus rhamnosus GG (LGG), a probiotic, given by gavage is radioprotective of the mouse intestine. LGG-induced radioprotection is toll-like receptor 2 (TLR2) and cyclooxygenase-2 (COX-2)-dependent and is associated with the migration of COX-2+mesenchymal stem cells (MSCs) from the lamina propria of the villus to the lamina propria near the crypt epithelial stem cells. Our goals were to define the mechanism of LGG radioprotection including identification of the TLR2 agonist, and the mechanism of the MSC migration and to determine the safety and efficacy of this approach in models relevant to clinical radiation therapy. Intestinal radioprotection was modelled in vitro with cell lines and enteroids as well as in vivo by assaying clinical outcomes and crypt survival. Fractionated abdominal and single dose radiation were used along with syngeneic CT26 colon tumour grafts to assess tumour radioprotection. LGG with a mutation in the processing of lipoteichoic acid (LTA), a TLR2 agonist, was not radioprotective, while LTA agonist and native LGG were. An agonist of CXCR4 blocked LGG-induced MSC migration and LGG-induced radioprotection. LGG given by gavage induced expression of CXCL12, a CXCR4 agonist, in pericryptal macrophages and depletion of macrophages by clodronate liposomes blocked LGG-induced MSC migration and radioprotection. LTA effectively protected the normal intestinal crypt, but not tumours in fractionated radiation regimens. LGG acts as a 'time-release capsule' releasing radioprotective LTA. LTA then primes the epithelial stem cell niche to protect epithelial stem cells by triggering a multicellular, adaptive immune signalling cascade involving macrophages and PGE2 secreting MSCs. NCT01790035; Pre-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

The influence of physical activity in 1,2 dimethylhydrazine induced colon carcinogenesis in the rat.

PubMed

Andrianopoulos, G; Nelson, R L; Bombeck, C T; Souza, G

1987-01-01

Recent epidemiologic findings indicate that relative risk of colon cancer is augmented with increasing proportion of time spent on sedentary occupations, and reduced with occupations requiring high levels of work-related physical activity. Therefore, the influence of exercise on experimental colon carcinogenesis was investigated. Spontaneous running wheel activity was related to incidence of 1,2 dimethylhydrazine (DMH) colon tumor induction. Colon tumor incidence was significantly reduced in animals that were allowed spontaneous wheel activity throughout the period of DMH tumor induction vs standard housed controls (p less than 0.05), indicating that, in the rat, physical activity protects against colon tumorigenesis. Further comparisons reveal a mild positive association (p = 0.07) between activity and incidence of tumors in the left colon. These results are in accord with epidemiologic findings indicating reduced colon cancer risk with increased physical activity. Possible mechanisms for the protective influence of physical activity on tumorigenesis include reduction in fecal pH, body weight and increased antioxidant enzyme activity. To the extent that epidemiologic associations between colon cancer and activity are inclusive of the multidimensional nature of physical activity, animal models such as that utilized in this experiment can be utilized for investigating the etiologic potential, or strength of association in variables that have been epidemiologically associated with colon cancer risk.

Downregulation of telomerase activity by diclofenac and curcumin is associated with cell cycle arrest and induction of apoptosis in colon cancer.

PubMed

Rana, Chandan; Piplani, Honit; Vaish, Vivek; Nehru, Bimla; Sanyal, S N

2015-08-01

Uncontrolled cell proliferation is the hallmark of cancer, and cancer cells have typically acquired damage to genes that directly regulate their cell cycles. The synthesis of DNA onto the end of chromosome during the replicative phase of cell cycle by telomerase may be necessary for unlimited proliferation of cells. Telomerase, a ribonucleoprotein enzyme is considered as a universal therapeutic target of cancer because of its preferential expression in cancer cells and its presence in 90 % of tumors. We studied the regulation of telomerase and telomerase reverse transcriptase catalytic subunit (TERT) by diclofenac and curcumin, alone and also in combination, in 1, 2-dimethylhydrazine dihydrochloride-induced colorectal cancer in rats. The relationship of telomerase activity with tumors suppressor proteins (p51, Rb, p21), cell cycle machinery, and apoptosis was also studied. Telomerase is highly expressed in DMH group and its high activity is associated with increased TERT expression. However, telomerase is absent or is present at lower levels in normal tissue. CDK4, CDK2, cyclin D1, and cyclin E are highly expressed in DMH as assessed by RT-PCR, qRT-PCR, Western blot, and immunofluorescence analysis. Diclofenac and curcumin overcome these carcinogenic effects by downregulating telomerase activity, diminishing the expression of TERT, CDK4, CDK2, cyclin D1, and cyclin E. The anticarcinogenic effects shown after the inhibition of telomerase activity by diclofenac and curcumin may be associated with upregulation of tumor suppressor proteins p51, Rb, and p21, whose activation induces the cells cycle arrest and apoptosis.

Structural and numerical chromosome aberration inducers in liver micronucleus test in rats with partial hepatectomy.

PubMed

Itoh, Satoru; Hattori, Chiharu; Nagata, Mayumi; Sanbuissho, Atsushi

2012-08-30

The liver micronucleus test is an important method to detect pro-mutagens such as active metabolites not reaching bone marrow due to their short lifespan. We have already reported that dosing of the test compound after partial hepatectomy (PH) is essential to detect genotoxicity of numerical chromosome aberration inducers in mice [Mutat. Res. 632 (2007) 89-98]. In naive animals, the proportion of binucleated cells in rats is less than half of that in mice, which suggests a species difference in the response to chromosome aberration inducers. In the present study, we investigated the responses to structural and numerical chromosome aberration inducers in the rat liver micronucleus test. Two structural chromosome aberretion inducers (diethylnitrosamine and 1,2-dimethylhydrazine) and two numerical chromosome aberration inducers (colchicine and carbendazim) were used in the present study. PH was performed a day before or after the dosing of the test compound in 8-week old male F344 rats and hepatocytes were isolated 4 days after the PH. As a result, diethylnitrosamine and 1,2-dimethylhydrazine, structural chromosome aberration inducers, exhibited significant increase in the incidence of micronucleated hepatocyte (MNH) when given either before and after PH. Colchicine and carbendazim, numerical chromosome aberration inducers, did not result in any toxicologically significant increase in MNH frequency when given before PH, while they exhibited MNH induction when given after PH. It is confirmed that dosing after PH is essential in order to detect genotoxicity of numerical chromosome aberration inducers in rats as well as in mice. Regarding the species difference, a different temporal response to colchicine was identified. Colchicine increased the incidence of MNH 4 days after PH in rats, although such induction in mice was observed 8-10 days after PH. Copyright © 2012 Elsevier B.V. All rights reserved.

Crypt dysplasia in Barrett's oesophagus shows clonal identity between crypt and surface cells.

PubMed

Khan, Shabuddin; McDonald, Stuart A C; Wright, Nicholas A; Graham, Trevor A; Odze, Robert D; Rodriguez-Justo, Manuel; Zeki, Sebastian

2013-09-01

Epithelial dysplasia is an important histological diagnosis signifying the presence of pre-invasive disease, usually needing intervention. However, the specific genetic changes responsible for the induction of this phenotypic change are unknown. Moreover, recent reports indicate that the dysplastic phenotype may not be immutable: in basal crypt dysplasia (CD), unequivocal dysplastic changes are seen in the crypts in Barrett's oesophagus and other pre-invasive lesions in the gastrointestinal tract, but the upper crypts and surface epithelium associated with these dysplastic crypts show the definitive morphology of a differentiated epithelium. The genotypic relationship between CD and the differentiated surface epithelium is presently unclear. We obtained 17 examples of CD: the lower and upper crypts and surface epithelium were differentially laser-microdissected from formalin-fixed, paraffin-embedded sections and mutations were sought in tumour suppressor genes frequently associated with progression in Barrett's oesophagus. We found two patients who both showed a c. C238T mutation in the CDKN2A (CDKN2AInk4A) gene and where the precise microanatomical relationships could be discerned: this mutation was present in both the CD at the crypt base and in the upper crypt and surface epithelium. We conclude that, in CD, the dysplastic basal crypt epithelium and the upper crypt and surface epithelium show clonal CDKN2A mutations, thus showing definitively that the surface epithelium is derived from the dysplastic crypt epithelium: the dysplastic phenotype is therefore not fixed and can be reversed. The mechanism of this change is unclear but may be related to the possibility that dysplastic cells can, probably early in their progression, respond to differentiation signals. However, it is also clear that a heavy mutational burden can be borne by crypts in the gastrointestinal tract without the development of phenotypic dysplasia. We are evidently some way from understanding the plasticity and the genotypic correlates of the dysplastic phenotype. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Hyperfiltration and effect of nitric oxide inhibition on renal and endothelial function in humans with uncomplicated type 1 diabetes mellitus

PubMed Central

Reich, Heather N.; Jiang, Shan; Har, Ronnie; Nasrallah, Rania; Hébert, Richard L.; Lai, Vesta; Scholey, James W.; Sochett, Etienne B.

2012-01-01

Studies of experimental diabetes mellitus (DM) suggest that increased nitric oxide (NO) bioactivity contributes to renal hyperfiltration. However, the role of NO in mediating hyperfiltration has not been fully elucidated in humans. Our aim was to examine the effect of NO synthase inhibition on renal and peripheral vascular function in normotensive subjects with uncomplicated type 1 DM. Renal function and brachial artery flow-mediated vasodilatation (FMD) were measured before and after an intravenous infusion of the NO synthase inhibitor NG-nitro-l-arginine methyl ester (l-NMMA) in 21 healthy control and 37 type 1 DM patients. Measurements in DM participants were made under clamped euglycemic conditions. The effect of l-NMMA on circulating and urinary NO metabolites (NOx) and cGMP and on urinary prostanoids was also determined. Baseline characteristics were similar in the two groups. For analysis, the DM patients were divided into those with hyperfiltration (DM-H, n = 18) and normal glomerular filtration rate (GFR) levels (DM-N, n = 19). Baseline urine NOx and cGMP were highest in DM-H. l-NMMA led to a decline in GFR in DM-H (152 ± 16 to 140 ± 11 ml·min−1·1.73 m−2) but not DM-N or healthy control participants. The decline in effective renal plasma flow in response to l-NMMA (806 ± 112 to 539 ± 80 ml·min−1·1.73 m−2) in DM-H was also exaggerated compared with the other groups (repeated measures ANOVA, P < 0.05), along with declines in urinary NOx metabolites and cGMP. Baseline FMD was lowest in DM-H compared with the other groups and did not change in response to l-NMMA. l-NMMA reduced FMD and plasma markers of NO bioactivity in the healthy control and DM-N groups. In patients with uncomplicated type 1 DM, renal hyperfiltration is associated with increased NO bioactivity in the kidney and reduced NO bioactivity in the systemic circulation, suggesting a paradoxical state of high renal and low systemic vascular NO bioactivity. PMID:22855276

Fermented dairy products modulate Citrobacter rodentium-induced colonic hyperplasia.

PubMed

Collins, James W; Chervaux, Christian; Raymond, Benoit; Derrien, Muriel; Brazeilles, Rémi; Kosta, Artemis; Chambaud, Isabelle; Crepin, Valerie F; Frankel, Gad

2014-10-01

We evaluated the protective effects of fermented dairy products (FDPs) in an infection model, using the mouse pathogen Citrobacter rodentium (CR). Treatment of mice with FDP formulas A, B, and C or a control product did not affect CR colonization, organ specificity, or attaching and effacing lesion formation. Fermented dairy product A (FDP-A), but neither the supernatant from FDP-A nor β-irradiated (IR) FDP-A, caused a significant reduction in colonic crypt hyperplasia and CR-associated pathology. Profiling the gut microbiota revealed that IR-FDP-A promoted higher levels of phylotypes belonging to Alcaligenaceae and a decrease in Lachnospiraceae (Ruminococcus) during CR infection. Conversely, FDP-A prevented a decrease in Ruminococcus and increased Turicibacteraceae (Turicibacter). Importantly, loss of Ruminococcus and Turicibacter has been associated with susceptibility to dextran sodium sulfate-induced colitis. Our results demonstrate that viable bacteria in FDP-A reduced CR-induced colonic crypt hyperplasia and prevented the loss of key bacterial genera that may contribute to disease pathology. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America.

Painting Analysis of Chromosome Aberrations Induced by Energetic Heavy Ions in Human Cells

NASA Technical Reports Server (NTRS)

Wu, Honglu

2006-01-01

FISH, mFISH, mBAND, telomere and centromere probes have been used to study chromosome aberrations induced in human cells exposed to low-and high-LET radiation in vitro. High-LET induced damages are mostly a single track effect. Unrejoined chromosome breaks (incomplete exchanges) and complex type aberrations were higher for high-LET. Biosignatures may depend on the method the samples are collected. Recent mBAND analysis has revealed more information about the nature of intra-chromosome exchanges. Whether space flight/microgravity affects radiation-induced chromosome aberration frequencies is still an open question.

Excitatory amino acid receptors in the dorsomedial hypothalamus mediate prostaglandin-evoked thermogenesis in brown adipose tissue.

PubMed

Madden, C J; Morrison, S F

2004-02-01

We determined whether the dorsomedial hypothalamus (DMH) plays a role in the thermogenic, metabolic, and cardiovascular effects evoked by centrally administered PGE2. Microinjection of PGE2 (170 pmol/60 nl) into the medial preoptic area of the hypothalamus in urethane-chloralose-anesthetized, artificially ventilated rats increased brown adipose tissue (BAT) sympathetic nerve activity (SNA; +207 +/- 18% of control), BAT temperature (1.5 +/- 0.2 degrees C), expired CO2 (0.9 +/- 0.1%), heart rate (HR; 106 +/- 12 beats/min), and mean arterial pressure (22 +/- 4 mmHg). Within 5 min of subsequent bilateral microinjections of the GABAA receptor agonist muscimol (120 pmol.60 nl-1.side-1) or the ionotropic excitatory amino acid antagonist kynurenate (6 nmol.60 nl-1.side-1) into the DMH, the PGE2-evoked increases were, respectively, attenuated by 91 +/- 3% and 108 +/- 7% for BAT SNA, by 73 +/- 12% and 102 +/- 28% for BAT temperature, by 100 +/- 4% and 125 +/- 21% for expired CO2, by 72 +/- 11% and 70 +/- 16% for HR, and by 84 +/- 19% and 113 +/- 16% for mean arterial pressure. Microinjections outside the DMH within the dorsal hypothalamic area adjacent to the mamillothalamic tracts or within the ventromedial hypothalamus were less effective for attenuating the PGE2-evoked thermogenic, metabolic, and cardiovascular responses. These results demonstrate that activation of excitatory amino acid receptors within the DMH is necessary for the thermogenic, metabolic, and cardiovascular responses evoked by microinjection of PGE2 into the medial preoptic area.

Wave aberrations in rhesus monkeys with vision-induced ametropias

PubMed Central

Ramamirtham, Ramkumar; Kee, Chea-su; Hung, Li-Fang; Qiao-Grider, Ying; Huang, Juan; Roorda, Austin; Smith, Earl L.

2007-01-01

The purpose of this study was to investigate the relationship between refractive errors and high-order aberrations in infant rhesus monkeys. Specifically, we compared the monochromatic wave aberrations measured with a Shack-Hartman wavefront sensor between normal monkeys and monkeys with vision-induced refractive errors. Shortly after birth, both normal monkeys and treated monkeys reared with optically induced defocus or form deprivation showed a decrease in the magnitude of high-order aberrations with age. However, the decrease in aberrations was typically smaller in the treated animals. Thus, at the end of the lens-rearing period, higher than normal amounts of aberrations were observed in treated eyes, both hyperopic and myopic eyes and treated eyes that developed astigmatism, but not spherical ametropias. The total RMS wavefront error increased with the degree of spherical refractive error, but was not correlated with the degree of astigmatism. Both myopic and hyperopic treated eyes showed elevated amounts of coma and trefoil and the degree of trefoil increased with the degree of spherical ametropia. Myopic eyes also exhibited a much higher prevalence of positive spherical aberration than normal or treated hyperopic eyes. Following the onset of unrestricted vision, the amount of high-order aberrations decreased in the treated monkeys that also recovered from the experimentally induced refractive errors. Our results demonstrate that high-order aberrations are influenced by visual experience in young primates and that the increase in high-order aberrations in our treated monkeys appears to be an optical byproduct of the vision-induced alterations in ocular growth that underlie changes in refractive error. The results from our study suggest that the higher amounts of wave aberrations observed in ametropic humans are likely to be a consequence, rather than a cause, of abnormal refractive development. PMID:17825347

SND1, a component of RNA-induced silencing complex, is up-regulated in human colon cancers and implicated in early stage colon carcinogenesis.

PubMed

Tsuchiya, Naoto; Ochiai, Masako; Nakashima, Katsuhiko; Ubagai, Tsuneyuki; Sugimura, Takashi; Nakagama, Hitoshi

2007-10-01

Colon cancers have been shown to develop after accumulation of multiple genetic and epigenetic alterations with changes in global gene expression profiles, contributing to the establishment of widely diverse phenotypes. Transcriptional and posttranscriptional regulation of gene expression by small RNA species, such as the small interfering RNA and microRNA and the RNA-induced silencing complex (RISC), is currently drawing major interest with regard to cancer development. SND1, also called Tudor-SN and p100 and recently reported to be a component of RISC, is among the list of highly expressed genes in human colon cancers. In the present study, we showed remarkable up-regulation of SND1 mRNA in human colon cancer tissues, even in early-stage lesions, and also in colon cancer cell lines. When mouse Snd1 was stably overexpressed in IEC6 rat intestinal epithelial cells, contact inhibition was lost and cell growth was promoted, even after the cells became confluent. Intriguingly, IEC6 cells with high levels of Snd1 also showed an altered distribution of E-cadherin from the cell membrane to the cytoplasm, suggesting loss of cellular polarity. Furthermore, the adenomatous polyposis coli (Apc) protein was coincidentally down-regulated, with no significant changes in the Apc mRNA level. Immunohistochemical analysis using chemically induced colonic lesions developed in rats revealed overexpression of Snd1 not only in colon cancers but also in aberrant crypt foci, putative precancerous lesions of the colon. Up-regulation of SND1 may thus occur at a very early stage in colon carcinogenesis and contribute to the posttranscriptional regulation of key players in colon cancer development, including APC and beta-catenin.

Lack of prevention of large intestinal cancer by VPS, an extract of Coriolus versicolor mushroom.

PubMed

Coles, Melissa; Toth, Bela

2005-01-01

Cancer prevention studies were conducted with VPS, a hot water extract of the Coriolus versicolor (CV) mushroom, in female Swiss mice. The extract was administered in the diet for life to the animals. Three groups of mice received the following treatments: a). 1,2-dimethylhydrazine dihydrochloride (1,2-DMH) was administered as 10 weekly subcutaneous injections of 20 microg/g body weight, starting at 9 weeks of age; b). VPS was given at a 2% dose level starting at 7 weeks of age followed by 1,2-DMH, as described in group a; c). 1,2-DMH was administered as described in group a followed by VPS at a 2% dose level starting at 21 weeks of age. The number of animals with large intestinal tumors and the total number of these tumors were: a). 30,321; b). 29,359; and c). 28,415. These differences are not statistically significant. Because extracts of the CV mushroom are used by cancer patients as nutritional supplements in the U.S., and particularly in the Orient, the present negative result should caution its users.

Optimality in the Development of Intestinal Crypts

PubMed Central

Itzkovitz, Shalev; Blat, Irene C.; Jacks, Tyler; Clevers, Hans; van Oudenaarden, Alexander

2012-01-01

SUMMARY Intestinal crypts in mammals are comprised of long-lived stem cells and shorter-lived progenies. These two populations are maintained in specific proportions during adult life. Here, we investigate the design principles governing the dynamics of these proportions during crypt morphogenesis. Using optimal control theory, we show that a proliferation strategy known as a “bang-bang” control minimizes the time to obtain a mature crypt. This strategy consists of a surge of symmetric stem cell divisions, establishing the entire stem cell pool first, followed by a sharp transition to strictly asymmetric stem cell divisions, producing nonstem cells with a delay. We validate these predictions using lineage tracing and single-molecule fluorescence in situ hybridization of intestinal crypts in infant mice, uncovering small crypts that are entirely composed of Lgr5-labeled stem cells, which become a minority as crypts continue to grow. Our approach can be used to uncover similar design principles in other developmental systems. PMID:22304925

Optimality in the Development of Intestinal Crypts

NASA Astrophysics Data System (ADS)

van Oudenaarden, Alexander

2012-02-01

Intestinal crypts in mammals are comprised of long-lived stem cells and shorter-lived progenies, maintained under tight proportions during adult life. Here we ask what are the design principles that govern the dynamics of these proportions during crypt morphogenesis. We use optimal control theory to show that a stem cell proliferation strategy known as a `bang-bang' control minimizes the time to obtain a mature crypt. This strategy consists of a surge of symmetric stem cell divisions, establishing the entire stem cell pool first, followed by a sharp transition to strictly asymmetric stem cell divisions, producing non-stem cells with a delay. We validate these predictions using lineage tracing and single molecule fluorescent in-situ hybridization of intestinal crypts in newborn mice and find that small crypts are entirely composed of Lgr5 stem cells, which become a minority as crypts further grow. Our approach can be used to uncover similar design principles in other developmental systems.

Chronic low vitamin intake potentiates cisplatin-induced intestinal epithelial cell apoptosis in WNIN rats

PubMed Central

Vijayalakshmi, Bodiga; Sesikeran, Boindala; Udaykumar, Putcha; Kalyanasundaram, Subramaniam; Raghunath, Manchala

2006-01-01

AIM: To investigate if cisplatin alters vitamin status and if VR modulates cisplatin induced intestinal apoptosis and oxidative stress in Wistar/NIN (WNIN) male rats. METHODS: Weanling, WNIN male rats (n = 12 per group) received adlibitum for 17 wk: control diet (20% protein) or the same with 50% vitamin restriction. They were then sub-divided into two groups of six rats each and administered cisplatin (2.61 mg/kg bodyweight) once a week for three wk or PBS (vehicle control). Intestinal epithelial cell (IEC) apoptosis was monitored by morphometry, Annexin-V binding, M30 cytodeath assay and DNA fragmentation. Structural and functional integrity of the villus were assessed by villus height / crypt depth ratio and activities of alkaline phosphatase, lys, ala-dipeptidyl amino-peptidase, respectively. To assess the probable mechanism(s) of altered apoptosis, oxidative stress parameters, caspase-3 activity, and expression of Bcl-2 and Bax were determined. RESULTS: Cisplatin per se decreased plasma vitamin levels and they were the lowest in VR animals treated with cisplatin. As expected VR increased only villus apoptosis, whereas cisplatin increased stem cell apoptosis in the crypt. However, cisplatin treatment of VR rats increased apoptosis both in villus and crypt regions and was associated with higher levels of TBARS, protein carbonyls and caspase-3 activity, but lower GSH concentrations. VR induced decrease in Bcl-2 expression was further lowered by cisplatin. Bax expression, unaffected by VR was increased on cisplatin treatment. Mucosal functional integrity was severely compromised in cisplatin treated VR-rats. CONCLUSION: Low intake of vitamins increases the sensitivity of rats to cisplatin and promotes intestinal epithelial cell apoptosis. PMID:16534849

Comparison of the circadian variation in cell proliferation in normal and neoplastic colonic epithelial cells.

PubMed

Kennedy, M F; Tutton, P J; Barkla, D H

1985-09-15

Circadian variations in cell proliferation in normal tissues have been recognised for many years but comparable phenomena in neoplastic tissues appear not to have been reported. Adenomas and carcinomas were induced in mouse colon by injection of dimethylhydrazine (DMH) and cell proliferation in these tumors was measured stathmokinetically. In normal intestine cell proliferation is fastest at night whereas in both adenomas and carcinomas it was found to be slower at night than in the middle of the day. Chemical sympathectomy was found to abolish the circadian variation in tumor cell proliferation.

THE RELATION BETWEEN DNA SYNTHESIS AND CHROMOSOME STRUCTURE AS RESOLVED BY X-RAY DAMAGE

PubMed Central

Evans, H. J.; Savage, J. R. K.

1963-01-01

Vicia faba root tip cells were treated for short periods with tritiated thymidine, either immediately before or after exposure of roots to x-rays, and autoradiograph preparations were analysed in an attempt to test the hypothesis that chromatid type (B') aberrations are induced only in those chromosome regions that have synthesized DNA prior to x-irradiation, whereas chromosome type (B'') aberrations are induced only in unduplicated chromosome regions. Studying the relation between presence or absence of label at loci involved in aberrations, in cells irradiated at different development stages, and the pattern of labelling in cells carrying both types of aberration leads to the conclusion that B'' aberrations are induced only in unreplicated chromosome regions. Following replication, only B' aberrations are induced, but these aberrations are also induced in chromosome regions preparing to incorporate DNA. It is suggested that the doubled response of the chromosome to x-rays prior to DNA incorporation might reflect a physical separation of replicating units prior to replication. The aberration yields in damaged cells which were irradiated in G 1 S, and early G 2 were in the ratio of 1.0:2.0:3.2. The data indicate that the increased yield of B' in early G 2 relative to S cells may be a consequence of changes in the spatial distribution of the chromosomes within the nucleus. PMID:14064107

Investigation of computer-aided colonic crypt pattern analysis

NASA Astrophysics Data System (ADS)

Qi, Xin; Pan, Yinsheng; Sivak, Michael V., Jr.; Olowe, Kayode; Rollins, Andrew M.

2007-02-01

Colorectal cancer is the second leading cause of cancer-related death in the United States. Approximately 50% of these deaths could be prevented by earlier detection through screening. Magnification chromoendoscopy is a technique which utilizes tissue stains applied to the gastrointestinal mucosa and high-magnification endoscopy to better visualize and characterize lesions. Prior studies have shown that shapes of colonic crypts change with disease and show characteristic patterns. Current methods for assessing colonic crypt patterns are somewhat subjective and not standardized. Computerized algorithms could be used to standardize colonic crypt pattern assessment. We have imaged resected colonic mucosa in vitro (N = 70) using methylene blue dye and a surgical microscope to approximately simulate in vivo imaging with magnification chromoendoscopy. We have developed a method of computerized processing to analyze the crypt patterns in the images. The quantitative image analysis consists of three steps. First, the crypts within the region of interest of colonic tissue are semi-automatically segmented using watershed morphological processing. Second, crypt size and shape parameters are extracted from the segmented crypts. Third, each sample is assigned to a category according to the Kudo criteria. The computerized classification is validated by comparison with human classification using the Kudo classification criteria. The computerized colonic crypt pattern analysis algorithm will enable a study of in vivo magnification chromoendoscopy of colonic crypt pattern correlated with risk of colorectal cancer. This study will assess the feasibility of screening and surveillance of the colon using magnification chromoendoscopy.

Effects of Ginger Supplementation on Cell Cycle Biomarkers in the Normal-Appearing Colonic Mucosa of Patients at Increased Risk for Colorectal Cancer: Results from a Pilot, Randomized, Controlled Trial

PubMed Central

Citronberg, Jessica; Bostick, Roberd; Ahearn, Thomas; Turgeon, D. Kim; Ruffin, Mack T.; Djuric, Zora; Sen, Ananda; Brenner, Dean E.; Zick, Suzanna M.

2013-01-01

To estimate the effects of ginger on apoptosis, proliferation, and differentiation in the normal-appearing colonic mucosa, we randomized 20 people at increased risk for colorectal cancer to 2.0 g of ginger or placebo daily for 28 days in a pilot trial. Overall expression and distributions of Bax, Bcl-2, p21, hTERT and MIB-1 (Ki-67) in colorectal crypts in rectal mucosa biopsies were measured using automated immunohistochemistry and quantitative image analysis. Relative to placebo, Bax expression in the ginger group decreased 15.6% (p = 0.78) in the whole crypts, 6.6% (p = 0.95) in the upper 40% (differentiation zone) of crypts, and 21.7% (p = 0.67) in the lower 60% (proliferative zone) of crypts; however, there was a 19% increase (p = 0.14) in Bax expression in the upper 40% relative to the whole crypt. While p21 and Bcl-2 expression remained relatively unchanged, hTERT expression in the whole crypts decreased by 41.2% (p = 0.05); the estimated treatment effect on hTERT expression was larger in the upper 40% of crypts (−47.9%; p = 0.04). In the ginger group, MIB-1 expression decreased in the whole crypts, upper 40% of crypts, and lower 60% of crypts by 16.9% (p = 0.39), 46.8% (p = 0.39), and 15.3% (p = 0.41), respectively. These pilot study results suggest that ginger may reduce proliferation in the normal-appearing colorectal epithelium and increase apoptosis and differentiation relative to proliferation—especially in the differentiation zone of the crypts, and support a larger study to further investigate these results. PMID:23303903

An individual based computational model of intestinal crypt fission and its application to predicting unrestrictive growth of the intestinal epithelium.

PubMed

Pin, Carmen; Parker, Aimee; Gunning, A Patrick; Ohta, Yuki; Johnson, Ian T; Carding, Simon R; Sato, Toshiro

2015-02-01

Intestinal crypt fission is a homeostatic phenomenon, observable in healthy adult mucosa, but which also plays a pathological role as the main mode of growth of some intestinal polyps. Building on our previous individual based model for the small intestinal crypt and on in vitro cultured intestinal organoids, we here model crypt fission as a budding process based on fluid mechanics at the individual cell level and extrapolated predictions for growth of the intestinal epithelium. Budding was always observed in regions of organoids with abundant Paneth cells. Our data support a model in which buds are biomechanically initiated by single stem cells surrounded by Paneth cells which exhibit greater resistance to viscoelastic deformation, a hypothesis supported by atomic force measurements of single cells. Time intervals between consecutive budding events, as simulated by the model and observed in vitro, were 2.84 and 2.62 days, respectively. Predicted cell dynamics was unaffected within the original crypt which retained its full capability of providing cells to the epithelium throughout fission. Mitotic pressure in simulated primary crypts forced upward migration of buds, which simultaneously grew into new protruding crypts at a rate equal to 1.03 days(-1) in simulations and 0.99 days(-1) in cultured organoids. Simulated crypts reached their final size in 4.6 days, and required 6.2 days to migrate to the top of the primary crypt. The growth of the secondary crypt is independent of its migration along the original crypt. Assuming unrestricted crypt fission and multiple budding events, a maximal growth rate of the intestinal epithelium of 0.10 days(-1) is predicted and thus approximately 22 days are required for a 10-fold increase of polyp size. These predictions are in agreement with the time reported to develop macroscopic adenomas in mice after loss of Apc in intestinal stem cells.

Secretagogue stimulation enhances NBCe1 (electrogenic Na(+)/HCO(3)(-) cotransporter) surface expression in murine colonic crypts.

PubMed

Yu, Haoyang; Riederer, Brigitte; Stieger, Nicole; Boron, Walter F; Shull, Gary E; Manns, Michael P; Seidler, Ursula E; Bachmann, Oliver

2009-12-01

A Na(+)/HCO(3)(-) cotransporter (NBC) is located in the basolateral membrane of the gastrointestinal epithelium, where it imports HCO(3)(-) during stimulated anion secretion. Having previously demonstrated secretagogue activation of NBC in murine colonic crypts, we now asked whether vesicle traffic and exocytosis are involved in this process. Electrogenic NBCe1-B was expressed at significantly higher levels than electroneutral NBCn1 in colonic crypts as determined by QRT-PCR. In cell surface biotinylation experiments, a time-dependent increase in biotinylated NBCe1 was observed, which occurred with a peak of +54.8% after 20 min with forskolin (P < 0.05) and more rapidly with a peak of +59.8% after 10 min with carbachol (P < 0.05) and which corresponded well with the time course of secretagogue-stimulated colonic bicarbonate secretion in Ussing chamber experiments. Accordingly, in isolated colonic crypts pretreated with forskolin and carbachol for 10 min, respectively, and subjected to immunohistochemistry, the NBCe1 signal showed a markedly stronger colocalization with the E-cadherin signal, which was used as a membrane marker, compared with the untreated control. Cytochalasin D did not change the observed increase in membrane abundance, whereas colchicine alone enhanced NBCe1 membrane expression without an additional increase after carbachol or forskolin, and LY294002 had a marked inhibitory effect. Taken together, our results demonstrate a secretagogue-induced increase of NBCe1 membrane expression. Vesicle traffic and exocytosis might thus represent a novel mechanism of intestinal NBC activation by secretagogues.

Stimulation of cell proliferation by histamine H2 receptors in dimethylhdrazine-induced adenocarcinomata.

PubMed

Tutton, P J; Barkla, D H

1978-03-01

Cell proliferation in dimethylhydrazine-induced colonic carcinomata was stimulated by histamine and by the histamine H2 receptor agonist dimaprit and inhibited by the histamine H2 receptor antagonists Metiamide and Cimetidine but not by the histamine H1 receptor antagonist Mepyramine. In contrast histamine had no effect on colonic crypt cell proliferation in normal or dimethylhydrazine-treated rats.

Effect of transforming growth factor-alpha on enterocyte apoptosis is correlated with EGF receptor expression along the villus-crypt axis during methotrexate-induced intestinal mucositis in a rat.

PubMed

Sukhotnik, Igor; Shteinberg, Dan; Ben Lulu, Shani; Bashenko, Yulia; Mogilner, Jorge G; Ure, Benno M; Shaoul, Ron; Coran, Arnold G

2008-11-01

The purpose of the present study was to evaluate the effect of transforming-growth factor-alpha (TGF-alpha) on enterocyte apoptosis following methotrexate (MTX) induced intestinal mucositis in a rat and in Caco-2 cells. Non-pretreated and pretreated with MTX Caco-2 cells were incubated with increasing concentrations of TGF-alpha. Cell apoptosis was determined by FACS cytometry. Adult rats were divided into four groups: Control, Control-TGF-alpha, MTX, and MTX- TGF-alpha rats. Three days later rats were sacrificed. Enterocyte apoptosis were measured at sacrifice. RT-PCR and Western Blotting was used to determine the level of Bax and Bcl-2 mRNA and protein. Real time PCR was used to measure epidermal growth factor receptor (EGFr) expression along the villus-crypt axis. The in vitro experiment has shown that treatment with TGF-alpha of Caco-2 cells results in a significant inhibition of cell apoptosis in a dose-dependent manner. In vivo experiment, a decreased levels of apoptosis in MTX- TGF-alpha rats corresponded with the decrease in Bax and with the increase in Bcl-2 at both mRNA and protein levels. The inhibiting effect of TGF-alpha on enterocyte apoptosis was strongly correlated with EGFr expression along the villus-crypt axis. In conclusion, treatment with TGF-alpha inhibits enterocyte apoptosis following MTX- injury in the rat.

Determination of aberration center of Ronchigram for automated aberration correctors in scanning transmission electron microscopy.

PubMed

Sannomiya, Takumi; Sawada, Hidetaka; Nakamichi, Tomohiro; Hosokawa, Fumio; Nakamura, Yoshio; Tanishiro, Yasumasa; Takayanagi, Kunio

2013-12-01

A generic method to determine the aberration center is established, which can be utilized for aberration calculation and axis alignment for aberration corrected electron microscopes. In this method, decentering induced secondary aberrations from inherent primary aberrations are minimized to find the appropriate axis center. The fitness function to find the optimal decentering vector for the axis was defined as a sum of decentering induced secondary aberrations with properly distributed weight values according to the aberration order. Since the appropriate decentering vector is determined from the aberration values calculated at an arbitrary center axis, only one aberration measurement is in principle required to find the center, resulting in /very fast center search. This approach was tested for the Ronchigram based aberration calculation method for aberration corrected scanning transmission electron microscopy. Both in simulation and in experiments, the center search was confirmed to work well although the convergence to find the best axis becomes slower with larger primary aberrations. Such aberration center determination is expected to fully automatize the aberration correction procedures, which used to require pre-alignment of experienced users. This approach is also applicable to automated aperture positioning. Copyright © 2013 Elsevier B.V. All rights reserved.

Structural centrosome aberrations sensitize polarized epithelia to basal cell extrusion.

PubMed

Ganier, Olivier; Schnerch, Dominik; Nigg, Erich A

2018-06-01

Centrosome aberrations disrupt tissue architecture and may confer invasive properties to cancer cells. Here we show that structural centrosome aberrations, induced by overexpression of either Ninein-like protein (NLP) or CEP131/AZI1, sensitize polarized mammalian epithelia to basal cell extrusion. While unperturbed epithelia typically dispose of damaged cells through apical dissemination into luminal cavities, certain oncogenic mutations cause a switch in directionality towards basal cell extrusion, raising the potential for metastatic cell dissemination. Here we report that NLP-induced centrosome aberrations trigger the preferential extrusion of damaged cells towards the basal surface of epithelial monolayers. This switch in directionality from apical to basal dissemination coincides with a profound reorganization of the microtubule cytoskeleton, which in turn prevents the contractile ring repositioning that is required to support extrusion towards the apical surface. While the basal extrusion of cells harbouring NLP-induced centrosome aberrations requires exogenously induced cell damage, structural centrosome aberrations induced by excess CEP131 trigger the spontaneous dissemination of dying cells towards the basal surface from MDCK cysts. Thus, similar to oncogenic mutations, structural centrosome aberrations can favour basal extrusion of damaged cells from polarized epithelia. Assuming that additional mutations may promote cell survival, this process could sensitize epithelia to disseminate potentially metastatic cells. © 2018 The Authors.

Impact of diet-induced obesity on intestinal stem cells: hyperproliferation but impaired intrinsic function that requires insulin/IGF1.

PubMed

Mah, Amanda T; Van Landeghem, Laurianne; Gavin, Hannah E; Magness, Scott T; Lund, P Kay

2014-09-01

Nutrient intake regulates intestinal epithelial mass and crypt proliferation. Recent findings in model organisms and rodents indicate nutrient restriction impacts intestinal stem cells (ISC). Little is known about the impact of diet-induced obesity (DIO), a model of excess nutrient intake on ISC. We used a Sox9-EGFP reporter mouse to test the hypothesis that an adaptive response to DIO or associated hyperinsulinemia involves expansion and hyperproliferation of ISC. The Sox9-EGFP reporter mouse allows study and isolation of ISC, progenitors, and differentiated lineages based on different Sox9-EGFP expression levels. Sox9-EGFP mice were fed a high-fat diet for 20 weeks to induce DIO and compared with littermates fed low-fat rodent chow. Histology, fluorescence activated cell sorting, and mRNA analyses measured impact of DIO on jejunal crypt-villus morphometry, numbers, and proliferation of different Sox9-EGFP cell populations and gene expression. An in vitro culture assay directly assessed functional capacity of isolated ISC. DIO mice exhibited significant increases in body weight, plasma glucose, insulin, and insulin-like growth factor 1 (IGF1) levels and intestinal Igf1 mRNA. DIO mice had increased villus height and crypt density but decreased intestinal length and decreased numbers of Paneth and goblet cells. In vivo, DIO resulted in a selective expansion of Sox9-EGFP(Low) ISC and percentage of ISC in S-phase. ISC expansion significantly correlated with plasma insulin levels. In vitro, isolated ISC from DIO mice formed fewer enteroids in standard 3D Matrigel culture compared to controls, indicating impaired ISC function. This decreased enteroid formation in isolated ISC from DIO mice was rescued by exogenous insulin, IGF1, or both. We conclude that DIO induces specific increases in ISC and ISC hyperproliferation in vivo. However, isolated ISC from DIO mice have impaired intrinsic survival and growth in vitro that can be rescued by exogenous insulin or IGF1.

Dimethylthiourea pretreatment inhibits endotoxin-induced compound exocytosis in goblet cells and plasma leakage of rat small intestine.

PubMed

Liu, Shang-Pin; Chang, Chien-Yu; Huang, Wen-Hung; Fu, Yaw-Syan; Chao, David; Huang, Hung-Tu

2010-01-01

Intravenous application of a high dose of endotoxin, also called lipopoly-saccharide (LPS), results in endotoxemia in animals, that induces production of cytokines and free radicals, systemic inflammation and mucin discharge from mucous tissues. The present study was to investigate (1) whether LPS application increased goblet cell secretion by compound exocytotic activity in mucosal villi and crypts of rat small intestine, and (2) whether hydroxyl radicals were involved in LPS-induced compound exocytosis in goblet cells and plasma leakage. Scanning electron microscopy showed that the numbers of goblet cells undergoing compound exocytosis (cavitated goblet cells) per mm(2) of ileal villus epithelium in rats 5 and 30 min after LPS (15 mg kg(-1)) were 693 +/- 196 (N = 6) and 547 +/- 213 (N = 6), respectively, which were 5.1 and 8.4 times (P < 0.05) the number of saline control. The percentage of villus cavitated goblet cell numbers, in both duodenum and ileum 5 min after LPS and in the ileum 30 min after LPS, increased significantly (P < 0.05). Pretreatment with dimethylthiourea (DMTU), a hydroxyl radical scavenger, decreased the number of cavitated goblet cells to saline control (P > 0.05). Morphometric analysis showed that the percentage of crypt epithelial area in the duodenum and ileum occupied by goblet cell mucin stores in the duodenum and ileum 30 min after LPS were 3.8 +/- 0.2% (N = 6) and 6.9 +/- 0.5 (N = 6), respectively reducing to one half the amount of control (P < 0.01). When DMTU was given prior to LPS the crypt goblet cell mucin stores and the amount of plasma leakage returned to the level of control. It is concluded that hydroxyl radicals were involved in the LPS-induced increase in compound exocytotic activity of goblet cells and the increase in plasma leakage during acute phases of inflammatory response in rat small intestine.

Chemopreventive and Antioxidant Effect of Polyphenol Free Spirulina maxima and Its Hydrolyzed Protein Content: Investigation on Azoxymethane Treated Mice

PubMed Central

Martínez-Palma, Nikte Y.; Dávila-Ortiz, Gloria; Jiménez-Martínez, Cristian; Madrigal-Bujaidar, Eduardo; Álvarez-González, Isela

2017-01-01

Background: Spirulina maxima (Sm) is known to have nutritive value as well as a number of potentially useful biomedical properties. Objectives: The initial purpose of this report was to evaluate the inhibitory effect of the alga (without its polyphenol content), on the induction of azoxymethane (AOM)-induced colon aberrant crypts (AC) in mouse. Besides, we hydrolyzed the protein content of such mixture. Our second aim was to determine the inhibitory potential of this last plant mixture on the AOM-induced colon AC in mouse. Moreover, we also determined the effect of the two indicated Sm samples on the oxidative damage caused by AOM in the colon and liver of treated mice. Materials and Methods: The experiment lasted 5 weeks. At the end, we registered the level of AC, nitric oxide, and the lipid and protein oxidation. Results: Our results showed the following: (1) the carcinogen increased more than 18 times the amount of the AC found in the control group. (2) On the contrary, the two tested mixtures of Sm produced a significant reduction over this damage (about 45%). (3) The two tested Sm mixtures were generally able to reduce the oxidative stress markers although with variable effects which go from 59% to 100% with respect to the control mice. Conclusion: Therefore, the present report established that the tested Sm fractions have mouse colon anticarcinogenic potential, partially related with their antioxidant capacity. Our report also suggested the need to further evaluate specific Sm chemicals as chemopreventive agents. PMID:28808375

Mitogenic action of tumour necrosis factor-alpha and interleukin-8 on explants of human duodenal mucosa.

PubMed

Zachrisson, K; Neopikhanov, V; Wretlind, B; Uribe, A

2001-08-07

Our aim is to examine whether tumour necrosis factor-alpha (TNF-alpha) and interleukin affect the mitotic activity in explants of human duodenal mucosa and to estimate the release of cytokines from explants incubated with TNF-alpha. Biopsy specimens of normal duodenal mucosa were taken from 19 subjects that underwent upper endoscopy for investigation of dyspeptic symptoms or chronic gastrointestinal bleeding. The specimens were processed following guidelines for organ culture technique. Paired biopsy specimens from 12 subjects were cultured for 23 h to achieve steady state and thereafter the explants were incubated 25 h with 10(-13)-10(-9) M of TNF-alpha or IL-8. Mitoses were arrested in the metaphase by adding vincristine sulphate for the last three hours. The explants were then fixed and processed for microdissection. Fifteen crypts were microdissected and the total number of metaphases was determined using the whole crypt as reference volume. The number of metaphases per crypt was also estimated in explants incubated with 10(-10) M TNF-alpha in the presence of anti-IL-8 antibodies. Additional duodenal explants from seven subjects were incubated with 10(-10) M TNF-alpha for 25 h. Thereafter the release of IL-1-beta, IL-6, IL-8 and interferon gamma (IFN-gamma) into the culture medium was measured by enzyme immunoassay and expressed as pg/mg protein. TNF-alpha and IL-8 significantly increased the number of metaphases/crypts (P<0.0001). The addition of anti-IL-8 slightly reduced the number of metaphases/crypt compared to the values observed in the explants incubated with 10(-10) M TNF-alpha alone (P<0.0001). The number of metaphases/crypt in the explants incubated with 10(-10) M TNF-alpha in the presence of anti-IL-8 antibodies was, however, markedly and significantly higher than that of the controls (P<0.000). TNF-alpha induced the release of IL-8 (P<0.01) and IL-6 (P<0.05) from the duodenal explants. TNF-alpha and IL-8 are potent mitogens to human small intestinal crypts. The mitogenic action of TNF-alpha is primarily a direct effect of the cytokine and only to a minor extent mediated by a secondary production of IL-8 in the duodenal explant. Our findings indicate that TNF-alpha and IL-8 may participate in the regulation of cell proliferation in the human small intestinal epithelium. Copyright 2001 Academic Press.

Structural centrosome aberrations promote non-cell-autonomous invasiveness.

PubMed

Ganier, Olivier; Schnerch, Dominik; Oertle, Philipp; Lim, Roderick Yh; Plodinec, Marija; Nigg, Erich A

2018-05-02

Centrosomes are the main microtubule-organizing centers of animal cells. Although centrosome aberrations are common in tumors, their consequences remain subject to debate. Here, we studied the impact of structural centrosome aberrations, induced by deregulated expression of ninein-like protein (NLP), on epithelial spheres grown in Matrigel matrices. We demonstrate that NLP-induced structural centrosome aberrations trigger the escape ("budding") of living cells from epithelia. Remarkably, all cells disseminating into the matrix were undergoing mitosis. This invasive behavior reflects a novel mechanism that depends on the acquisition of two distinct properties. First, NLP-induced centrosome aberrations trigger a re-organization of the cytoskeleton, which stabilizes microtubules and weakens E-cadherin junctions during mitosis. Second, atomic force microscopy reveals that cells harboring these centrosome aberrations display increased stiffness. As a consequence, mitotic cells are pushed out of mosaic epithelia, particularly if they lack centrosome aberrations. We conclude that centrosome aberrations can trigger cell dissemination through a novel, non-cell-autonomous mechanism, raising the prospect that centrosome aberrations contribute to the dissemination of metastatic cells harboring normal centrosomes. © 2018 The Authors. Published under the terms of the CC BY NC ND 4.0 license.

Quantification of Crypt and Stem Cell Evolution in the Normal and Neoplastic Human Colon

PubMed Central

Baker, Ann-Marie; Cereser, Biancastella; Melton, Samuel; Fletcher, Alexander G.; Rodriguez-Justo, Manuel; Tadrous, Paul J.; Humphries, Adam; Elia, George; McDonald, Stuart A.C.; Wright, Nicholas A.; Simons, Benjamin D.; Jansen, Marnix; Graham, Trevor A.

2014-01-01

Summary Human intestinal stem cell and crypt dynamics remain poorly characterized because transgenic lineage-tracing methods are impractical in humans. Here, we have circumvented this problem by quantitatively using somatic mtDNA mutations to trace clonal lineages. By analyzing clonal imprints on the walls of colonic crypts, we show that human intestinal stem cells conform to one-dimensional neutral drift dynamics with a “functional” stem cell number of five to six in both normal patients and individuals with familial adenomatous polyposis (germline APC−/+). Furthermore, we show that, in adenomatous crypts (APC−/−), there is a proportionate increase in both functional stem cell number and the loss/replacement rate. Finally, by analyzing fields of mtDNA mutant crypts, we show that a normal colon crypt divides around once every 30–40 years, and the division rate is increased in adenomas by at least an order of magnitude. These data provide in vivo quantification of human intestinal stem cell and crypt dynamics. PMID:25127143

Modelling Spatially Regulated β-Catenin Dynamics and Invasion in Intestinal Crypts

PubMed Central

Murray, Philip J.; Kang, Jun-Won; Mirams, Gary R.; Shin, Sung-Young; Byrne, Helen M.; Maini, Philip K.; Cho, Kwang-Hyun

2010-01-01

Experimental data (e.g., genetic lineage and cell population studies) on intestinal crypts reveal that regulatory features of crypt behavior, such as control via morphogen gradients, are remarkably well conserved among numerous organisms (e.g., from mouse and rat to human) and throughout the different regions of the small and large intestines. In this article, we construct a partial differential equation model of a single colonic crypt that describes the spatial distribution of Wnt pathway proteins along the crypt axis. The novelty of our continuum model is that it is based upon assumptions that can be directly related to processes at the cellular and subcellular scales. We use the model to predict how the distributions of Wnt pathway proteins are affected by mutations. The model is then extended to investigate how mutant cell populations can invade neighboring crypts. The model simulations suggest that cell crowding caused by increased proliferation and decreased cell loss may be sufficient for a mutant cell population to colonize a neighboring healthy crypt. PMID:20682248

Generation, Characterization and Application of Antibodies Directed against HERV-H Gag Protein in Colorectal Samples

PubMed Central

Mullins, Christina S.; Hühns, Maja; Krohn, Mathias; Peters, Sven; Cheynet, Valérie; Oriol, Guy; Guillotte, Michèle; Ducrot, Sandrine; Mallet, François; Linnebacher, Michael

2016-01-01

Introduction A substantial part of the human genome originates from transposable elements, remnants of ancient retroviral infections. Roughly 8% of the human genome consists of about 400,000 LTR elements including human endogenous retrovirus (HERV) sequences. Mainly, the interplay between epigenetic and post-transcriptional mechanisms is thought to silence HERV expression in most physiological contexts. Interestingly, aberrant reactivation of several HERV-H loci appears specific to colorectal carcinoma (CRC). Results The expression of HERV-H Gag proteins (Gag-H) was assessed using novel monoclonal mouse anti Gag-H antibodies. In a flow cytometry screen four antibody clones were tested on a panel of primary CRC cell lines and the most well performing ones were subsequently validated in western blot analysis. Finally, Gag-H protein expression was analyzed by immune histology on cell line cytospins and on clinical samples. There, we found a heterogeneous staining pattern with no background staining of endothelial, stromal and infiltrating immune cells but diffuse staining of the cytoplasm for positive tumor and normal crypt cells of the colonic epithelium. Conclusion Taken together, the Gag-H antibody clone(s) present a valuable tool for staining of cells with colonic origin and thus form the basis for future more detailed investigations. The observed Gag-H protein staining in colonic epithelium crypt cells demands profound analyses of a potential role for Gag-H in the normal physiology of the human gut. PMID:27119520

Exhaustive physical exercise increases the number of colonic preneoplastic lesions in untrained rats treated with a chemical carcinogen.

PubMed

Demarzo, Marcelo Marcos Piva; Garcia, Sérgio Britto

2004-12-08

Aberrant crypt foci (ACF) have been used for early detection of factors that influence colorectal carcinogenesis in rats. It has been observed that exhaustive exercise increases free radical DNA oxidative damage and depresses immune function, events also related to the increased risk for cancer development. Fifteen days after a single exhaustive swimming bout in untrained rats treated with a colon carcinogen, we observed a statistically significant increased number of ACF when compared to the non-exercised group. Thus, we concluded that exhaustive exercise increased the susceptibility for colon cancer in rats. From our finding and literature data, we hypothesize that, similarly to the suggested relationship between exercise and infections, exercise could be protective against cancer or it could increase the risk for this disease depending on its type, dose and duration.

Gametocidal chromosomes enhancing chromosome aberration in common wheat induced by 5-azacytidine.

PubMed

Su, W-Y; Cong, W-W; Shu, Y-J; Wang, D; Xu, G-H; Guo, C-H

2013-07-08

The gametocidal (Gc) chromosome from Aegilops spp induces chromosome mutation, which is introduced into common wheat as a tool of chromosome manipulation for genetic improvement. The Gc chromosome functions similar to a restriction-modification system in bacteria, in which DNA methylation is an important regulator. We treated root tips of wheat carrying Gc chromosomes with the hypomethylation agent 5-azacytidine; chromosome breakage and micronuclei were observed in these root tips. The frequency of aberrations differed in wheat containing different Gc chromosomes, suggesting different functions inducing chromosome breakage. Gc chromosome 3C caused the greatest degree of chromosome aberration, while Gc chromosome 3C(SAT) and 2C caused only slight chromosome aberration. Gc chromosome 3C induced different degrees of chromosome aberration in wheat varieties Triticum aestivum var. Chinese Spring and Norin 26, demonstrating an inhibition function in common wheat.

Effect of natural honey from Ilam and metformin for improving glycemic control in streptozotocin-induced diabetic rats

PubMed Central

Nasrolahi, Ozra; Heidari, Reza; Rahmani, Fatima; Farokhi, Farah

2012-01-01

Objective(s): Diabetes mellitus is a public health problem and one of the five leading causes of death globally. In the present study, the effect of Metformin with natural honey was investigated on glycemia in the Streptozotocin-induced diabetic rats. Materials and Methods: Thirty Wistar male rats were randomly divided into six groups including C: non diabetic rats received distilled water, CH: non diabetic rats received honey, CD: diabetic rats administered with distilled water, DM: Metformin treated diabetic rats, DH: honey treated diabetic rats, and DMH: diabetic rats treated with a combination of Metformin and natural honey. Diabetes was induced by a single dose of Streptozotocin (65 mg/kg; i.p.). The animals were treated by oral gavage once daily for four weeks. At the end of the treatment period, the animals were sacrificed and their blood samples collected. Amount of glucose, triglyceride (TG), total cholesterol (TC), HDL cholesterol, LDL cholesterol, VLDL cholesterol, total bilirubin, and albumin were determined in serum. Results: Group CD: showed hyperglycemia (252.2±4.1 mg/dl), while level of blood glucose was significantly (p<0.01) reduced in groups DH (124.2±2.7 mg/dl), DM (108.0±3.4 mg/dl), and DMH (115.4±2.1 mg/dl). Honey in combination with Metformin significantly (p<0.01) reduced level of bilirubin but Metformin alone did not reduce bilirubin. Honey alone and in combination with Metformin also significantly reduced triglycerides, total cholesterol, LDL, VLDL and increased HDL, but Metformin did not reduced triglycerides and increased HDL. Conclusion: The results of the present study demonstrated that consuming natural honey with Metformin improves glycemic control and is more useful than consuming Metformin alone. The higher therapeutic effect of Ilam honey on lipid abnormalities than Tualang honey was also evident. PMID:25050251

Fluorescent labelling of intestinal epithelial cells reveals independent long-lived intestinal stem cells in a crypt

DOE Office of Scientific and Technical Information (OSTI.GOV)

Horita, Nobukatsu; Tsuchiya, Kiichiro, E-mail: kii.gast@tmd.ac.jp; Hayashi, Ryohei

Highlights: • Lentivirus mixed with Matrigel enables direct infection of intestinal organoids. • Our original approach allows the marking of a single stem cell in a crypt. • Time-lapse imaging shows the dynamics of a single stem cell. • Our lentivirus transgene system demonstrates plural long-lived stem cells in a crypt. - Abstract: Background and aims: The dynamics of intestinal stem cells are crucial for regulation of intestinal function and maintenance. Although crypt stem cells have been identified in the intestine by genetic marking methods, identification of plural crypt stem cells has not yet been achieved as they are visualisedmore » in the same colour. Methods: Intestinal organoids were transferred into Matrigel® mixed with lentivirus encoding mCherry. The dynamics of mCherry-positive cells was analysed using time-lapse imaging, and the localisation of mCherry-positive cells was analysed using 3D immunofluorescence. Results: We established an original method for the introduction of a transgene into an organoid generated from mouse small intestine that resulted in continuous fluorescence of the mCherry protein in a portion of organoid cells. Three-dimensional analysis using confocal microscopy showed a single mCherry-positive cell in an organoid crypt that had been cultured for >1 year, which suggested the presence of long-lived mCherry-positive and -negative stem cells in the same crypt. Moreover, a single mCherry-positive stem cell in a crypt gave rise to both crypt base columnar cells and transit amplifying cells. Each mCherry-positive and -negative cell contributed to the generation of organoids. Conclusions: The use of our original lentiviral transgene system to mark individual organoid crypt stem cells showed that long-lived plural crypt stem cells might independently serve as intestinal epithelial cells, resulting in the formation of a completely functional villus.« less

Human colonic crypts in culture: segregation of immunochemical markers in normal versus adenoma-derived.

PubMed

Dame, Michael K; Jiang, Yan; Appelman, Henry D; Copley, Kelly D; McClintock, Shannon D; Aslam, Muhammad Nadeem; Attili, Durga; Elmunzer, B Joseph; Brenner, Dean E; Varani, James; Turgeon, D Kim

2014-02-01

In order to advance a culture model of human colonic neoplasia, we developed methods for the isolation and in vitro maintenance of intact colonic crypts from normal human colon tissue and adenomas. Crypts were maintained in three-dimensional Matrigel culture with a simple, serum-free, low Ca(2+) (0.15 mM) medium. Intact colonic crypts from normal human mucosa were viably maintained for 3-5 days with preservation of the in situ crypt-like architecture, presenting a distinct base and apex. Abnormal structures from adenoma tissue could be maintained through multiple passages (up to months), with expanding buds/tubules. Immunohistochemical markers for intestinal stem cells (Lgr5), growth (Ki67), differentiation (E-cadherin, cytokeratin 20 (CK20) and mucin 2 (MUC2)) and epithelial turnover (Bax, cleaved Caspase-3), paralleled the changes in function. The epithelial cells in normal crypts followed the physiological sequence of progression from proliferation to differentiation to dissolution in a spatially and temporally appropriate manner. Lgr5 expression was seen in a few basal cells of freshly isolated crypts, but was not detected after 1-3 days in culture. After 24 h in culture, crypts from normal colonic tissue continued to show strong Ki67 and MUC2 expression at the crypt base, with a gradual decrease over time such that by days 3-4 Ki67 was not expressed. The differentiation marker CK20 increased over the same period, eventually becoming intense throughout the whole crypt. In adenoma-derived structures, expression of markers for all stages of progression persisted for the entire time in culture. Lgr5 showed expression in a few select cells after months in culture. Ki67 and MUC2 were largely associated with the proliferative budding regions while CK20 was localized to the parent structure. This ex vivo culture model of normal and adenomatous crypts provides a readily accessible tool to help understand the growth and differentiation process in human colonic epithelium.

Scap is required for sterol synthesis and crypt growth in intestinal mucosa.

PubMed

McFarlane, Matthew R; Cantoria, Mary Jo; Linden, Albert G; January, Brandon A; Liang, Guosheng; Engelking, Luke J

2015-08-01

SREBP cleavage-activating protein (Scap) is an endoplasmic reticulum membrane protein required for cleavage and activation of sterol regulatory element-binding proteins (SREBPs), which activate the transcription of genes in sterol and fatty acid biosynthesis. Liver-specific loss of Scap is well tolerated; hepatic synthesis of sterols and fatty acids is reduced, but mice are otherwise healthy. To determine whether Scap loss is tolerated in the intestine, we generated a mouse model (Vil-Scap(-)) in which tamoxifen-inducible Cre-ER(T2), a fusion protein of Cre recombinase with a mutated ligand binding domain of the human estrogen receptor, ablates Scap in intestinal mucosa. After 4 days of tamoxifen, Vil-Scap(-) mice succumb with a severe enteropathy and near-complete collapse of intestinal mucosa. Organoids grown ex vivo from intestinal crypts of Vil-Scap(-) mice are readily killed when Scap is deleted by 4-hydroxytamoxifen. Death is prevented when culture medium is supplemented with cholesterol and oleate. These data show that, unlike the liver, the intestine requires Scap to sustain tissue integrity by maintaining the high levels of lipid synthesis necessary for proliferation of intestinal crypts. Copyright © 2015 by the American Society for Biochemistry and Molecular Biology, Inc.

GLUT-5 expression in neonatal rats: crypt-villus location and age-dependent regulation.

PubMed

Jiang, L; David, E S; Espina, N; Ferraris, R P

2001-09-01

The rat fructose transporter normally appears after completion of weaning but can be precociously induced by early feeding of a high-fructose diet. In this study, the crypt-villus site, the metabolic nature of the signal, and the age dependence of induction were determined. In weaning rats fed high-glucose pellets, GLUT-5 mRNA expression was modest, localized mainly in the upper three-fourths of the villus, and there was little expression in the villus base. When fed high-fructose pellets, GLUT-5 mRNA expression was two to three times greater in all regions except the villus base. Intestinal perfusion in vivo of a nonmetabolizable fructose analog, 3-O-methylfructose, tended to increase fructose uptake rate and moderately increased GLUT-5 mRNA abundance but had no effect on glucose uptake rates and SGLT1 mRNA abundance. Gavage feeding of high-fructose, but not high-glucose, solutions enhanced fructose uptake only in pups > or =14 days, suggesting that GLUT-5 regulation is markedly age dependent. Fructose or its metabolites upregulate GLUT-5 expression in all enterocytes, except those in the crypt and villus base and in pups <14 days old.

Dynamic magnetic hysteresis and nonlinear susceptibility of antiferromagnetic nanoparticles

NASA Astrophysics Data System (ADS)

Kalmykov, Yuri P.; Ouari, Bachir; Titov, Serguey V.

2016-08-01

The nonlinear ac stationary response of antiferromagnetic nanoparticles subjected to both external ac and dc fields of arbitrary strength and orientation is investigated using Brown's continuous diffusion model. The nonlinear complex susceptibility and dynamic magnetic hysteresis (DMH) loops of an individual antiferromagnetic nanoparticle are evaluated and compared with the linear regime for extensive ranges of the anisotropy, the ac and dc magnetic fields, damping, and the specific antiferromagnetic parameter. It is shown that the shape and area of the DMH loops of antiferromagnetic particles are substantially altered by applying a dc field that permits tuning of the specific magnetic power loss in the nanoparticles.

N-halamine-based rechargeable antimicrobial and biofilm-controlling polyurethane

PubMed Central

Sun, Xinbo; Cao, Zhengbing; Porteous, Nuala; Sun, Yuyu

2012-01-01

An N-halamine precursor, 5, 5-dimethyl hydantoin (DMH), was covalently linked to the surface of polyurethane (PU) with 1,6-hexamethylene diisocyanate (HDI) as a coupling agent. The reaction pathways were investigated using propyl isocyanate (PI) as a model compound, and the results suggested that the imide and amide groups of DMH had very similar reactivity toward the isocyanate groups on PU surfaces activated with HDI. After bleach treatment, the covalently bound DMH moieties were transformed into N-halamines. The new N-halmaine-based PU provided potent antimicrobial effects against Staphylococcus aureus (S. aureus, Gram-positive), Escherichia coli (E. coli, Gram-negative), methicillin-resistant staphylococcus aureus (MRSA, drug resistant Gram-positive bacteria), vancomycin-resistant enterococcus (VRE, drug resistant Gram-positive bacteria), and Candida albicans (C. ablicans, fungi), and successfully prevented bacterial and fungal biofilm formation. The antimicrobial and biofilm-controlling effects were stable for longer than 6 months under normal storage in open air. Furthermore, if the functions were lost due to prolonged use, they could be recharged by another chlorination treatment. The recharging could be repeated as needed to achieve long-term protection against microbial contamination and biofilm-formation. PMID:22244984

Cell organisation in the colonic crypt: a theoretical comparison of the pedigree and niche concepts.

PubMed

van der Wath, Richard C; Gardiner, Bruce S; Burgess, Antony W; Smith, David W

2013-01-01

The intestinal mucosa is a monolayer of rapidly self-renewing epithelial cells which is not only responsible for absorption of water and nutrients into the bloodstream but also acts as a protective barrier against harmful microbes entering the body. New functional epithelial cells are produced from stem cells, and their proliferating progeny. These stem cells are found within millions of crypts (tubular pits) spaced along the intestinal tract. The entire intestinal epithelium is replaced every 2-3 days in mice (3-5 days in humans) and hence cell production, differentiation, migration and turnover need to be tightly regulated. Malfunctions in this regulation are strongly linked to inflammatory bowel diseases and to the formation of adenomas and ultimately cancerous tumours. Despite a great deal of biological experimentation and observation, precisely how colonic crypts are regulated to produce mature colonocytes remains unclear. To assist in understanding how cell organisation in crypts is achieved, two very different conceptual models of cell behaviour are developed here, referred to as the 'pedigree' and the 'niche' models. The pedigree model proposes that crypt cells are largely preprogrammed and receive minimal prompting from the environment as they move through a routine of cell differentiation and proliferation to become mature colonocytes. The niche model proposes that crypt cells are primarily influenced by the local microenvironments along the crypt, and that predetermined cell behaviour plays a negligible role in their development. In this paper we present a computational model of colonic crypts in the mouse, which enables a comparison of the quality and controllability of mature coloncyte production by crypts operating under these two contrasting conceptual models of crypt regulation.

Cell Organisation in the Colonic Crypt: A Theoretical Comparison of the Pedigree and Niche Concepts

PubMed Central

van der Wath, Richard C.; Gardiner, Bruce S.; Burgess, Antony W.; Smith, David W.

2013-01-01

The intestinal mucosa is a monolayer of rapidly self-renewing epithelial cells which is not only responsible for absorption of water and nutrients into the bloodstream but also acts as a protective barrier against harmful microbes entering the body. New functional epithelial cells are produced from stem cells, and their proliferating progeny. These stem cells are found within millions of crypts (tubular pits) spaced along the intestinal tract. The entire intestinal epithelium is replaced every 2–3 days in mice (3–5 days in humans) and hence cell production, differentiation, migration and turnover need to be tightly regulated. Malfunctions in this regulation are strongly linked to inflammatory bowel diseases and to the formation of adenomas and ultimately cancerous tumours. Despite a great deal of biological experimentation and observation, precisely how colonic crypts are regulated to produce mature colonocytes remains unclear. To assist in understanding how cell organisation in crypts is achieved, two very different conceptual models of cell behaviour are developed here, referred to as the ‘pedigree’ and the ‘niche’ models. The pedigree model proposes that crypt cells are largely preprogrammed and receive minimal prompting from the environment as they move through a routine of cell differentiation and proliferation to become mature colonocytes. The niche model proposes that crypt cells are primarily influenced by the local microenvironments along the crypt, and that predetermined cell behaviour plays a negligible role in their development. In this paper we present a computational model of colonic crypts in the mouse, which enables a comparison of the quality and controllability of mature coloncyte production by crypts operating under these two contrasting conceptual models of crypt regulation. PMID:24069177

Emodin protects mice against radiation-induced mortality and intestinal injury via inhibition of apoptosis and modulation of p53.

PubMed

Wang, Jing; Zhang, Yue; Zhu, Qiuzhen; Liu, Yulan; Cheng, Hao; Zhang, Yuefan; Li, Tiejun

2016-09-01

The aim of this study was to explore the protective effect of emodin, a plant-derived anthraquinone, against gamma radiation-induced mortality and intestinal injury in mice, and to investigate the radioprotective molecular mechanism. C57BL/6 male mice were pre-treated with emodin for 7days via oral gavage before gamma radiation. We found that pretreatment with emodin prolonged mice survival time after 9Gy total body irradiation (TBI). Mice were sacrificed at 1 week after 7Gy TBI, we found that emodin attenuated intestinal morphological changes and increased villus height, crypt numbers, and reduced villus and crypt apoptosis as well as inhibited the expression of p53. MTT assay, flow cytometry, Hoechst 33258 staining, real-time PCR, and Western blotting indicated that emodin pretreatment can effectively increase human umbilical venous endothelial cells (HUVECs) viability and attenuate cell apoptosis; it also inhibited the expression of p53, Bax, and Caspase3 in HUVECs after irradiation. In summary, these results suggest the potential of emodin as an effective radioprotectant against radiation-induced intestinal injury. Copyright © 2016 Elsevier B.V. All rights reserved.

Bardoxolone Methyl Prevents High-Fat Diet-Induced Colon Inflammation in Mice

PubMed Central

Dinh, Chi H. L.; Yu, Yinghua; Szabo, Alexander; Zhang, Qingsheng; Zhang, Peng; Huang, Xu-Feng

2016-01-01

Obesity induces chronic, low-grade inflammation, which increases the risk of colon cancer. We investigated the preventive effects of Bardoxolone methyl (BARD) on high-fat diet (HFD)-induced inflammation in a mouse colon. Male C57BL/6J mice (n=7) were fed a HFD (HFD group), HFD plus BARD (10 mg/kg) in drinking water (HFD/BARD group), or normal laboratory chow diet (LFD group) for 21 weeks. In HFD mice, BARD reduced colon thickness and decreased colon weight per length. This was associated with an increase in colon crypt depth and the number of goblet cells per crypt. BARD reduced the expression of F4/80 and CD11c but increased CD206 and IL-10, indicating an anti-inflammatory effect. BARD prevented an increase of the intracellular pro-inflammatory biomarkers (NF-қB, p NF-қB, IL-6, TNF-α) and cell proliferation markers (Cox2 and Ki67). BARD prevented fat deposition in the colon wall and prevented microbial population changes. Overall, we report the preventive effects of BARD on colon inflammation in HFD-fed mice through its regulation of macrophages, NF-қB, cytokines, Cox2 and Ki67, fat deposition and microflora. PMID:26920068

Nodal aberration theory applied to freeform surfaces

NASA Astrophysics Data System (ADS)

Fuerschbach, Kyle; Rolland, Jannick P.; Thompson, Kevin P.

2014-12-01

When new three-dimensional packages are developed for imaging optical systems, the rotational symmetry of the optical system is often broken, changing its imaging behavior and making the optical performance worse. A method to restore the performance is to use freeform optical surfaces that compensate directly the aberrations introduced from tilting and decentering the optical surfaces. In order to effectively optimize the shape of a freeform surface to restore optical functionality, it is helpful to understand the aberration effect the surface may induce. Using nodal aberration theory the aberration fields induced by a freeform surface in an optical system are explored. These theoretical predications are experimentally validated with the design and implementation of an aberration generating telescope.

Interleukin-22 drives nitric oxide-dependent DNA damage and dysplasia in a murine model of colitis-associated cancer

PubMed Central

Sheh, A; Muthupalani, S; Bryant, EM; Puglisi, DA; Holcombe, H; Conaway, EA; Parry, NAP; Bakthavatchalu, V; Short, SP; Williams, CS; Wogan, GN; Tannenbaum, SR; Fox, JG; Horwitz, BH

2017-01-01

The risk of colon cancer is increased in patients with Crohn's disease and ulcerative colitis. Inflammation-induced DNA damage could be an important link between inflammation and cancer, although the pathways that link inflammation and DNA damage are incompletely defined. RAG2-deficient mice infected with Helicobacter hepaticus (Hh) develop colitis that progresses to lower bowel cancer. This process depends on nitric oxide (NO), a molecule with known mutagenic potential. We have previously hypothesized that production of NO by macrophages could be essential for Hh-driven carcinogenesis, however, whether Hh-infection induces DNA damage in this model and whether this depends on NO has not been determined. Here, we demonstrate that Hh infection of RAG2-deficient mice rapidly induces expression of iNOS and the development of DNA double-stranded breaks (DSBs) specifically in proliferating crypt epithelial cells. Generation of DSBs depended on iNOS activity, and further, induction of iNOS, the generation of DSBs, and the subsequent development of dysplasia were inhibited by depletion of the Hh-induced cytokine IL-22. These results demonstrate a strong association between Hh-induced DNA damage and the development of dysplasia, and further suggest that IL-22 dependent induction of iNOS within crypt epithelial cells rather than macrophages is a driving force in this process. PMID:28198364

Murine P-glycoprotein deficiency alters intestinal injury repair and blunts lipopolysaccharide-induced radioprotection.

PubMed

Staley, Elizabeth M; Yarbrough, Vanisha R; Schoeb, Trenton R; Daft, Joseph G; Tanner, Scott M; Steverson, Dennis; Lorenz, Robin G

2012-09-01

P-glycoprotein (P-gp) has been reported to increase stem cell proliferation and regulate apoptosis. Absence of P-gp results in decreased repair of intestinal epithelial cells after chemical injury. To further explore the mechanisms involved in the effects of P-gp on intestinal injury and repair, we used the well-characterized radiation injury model. In this model, injury repair is mediated by production of prostaglandins (PGE(2)) and lipopolysaccharide (LPS) has been shown to confer radioprotection. B6.mdr1a(-/-) mice and wild-type controls were subjected to 12 Gy total body X-ray irradiation and surviving crypts in the proximal jejunum and distal colon were evaluated 3.5 days after irradiation. B6.mdr1a(-/-) mice exhibited normal baseline stem cell proliferation and COX dependent crypt regeneration after irradiation. However, radiation induced apoptosis was increased and LPS-induced radioprotection was blunted in the C57BL6.mdr1a(-/-) distal colon, compared to B6 wild-type controls. The LPS treatment induced gene expression of the radioprotective cytokine IL-1α, in B6 wild-type controls but not in B6.mdr1a(-/-) animals. Lipopolysaccharid-induced radioprotection was absent in IL-1R1(-/-) animals, indicating a role for IL-1α in radioprotection, and demonstrating that P-gp deficiency interferes with IL-1α gene expression in response to systemic exposure to LPS.

Using crypts as iris minutiae

NASA Astrophysics Data System (ADS)

Shen, Feng; Flynn, Patrick J.

2013-05-01

Iris recognition is one of the most reliable biometric technologies for identity recognition and verification, but it has not been used in a forensic context because the representation and matching of iris features are not straightforward for traditional iris recognition techniques. In this paper we concentrate on the iris crypt as a visible feature used to represent the characteristics of irises in a similar way to fingerprint minutiae. The matching of crypts is based on their appearances and locations. The number of matching crypt pairs found between two irises can be used for identity verification and the convenience of manual inspection makes iris crypts a potential candidate for forensic applications.

M-BAND Study of Radiation-Induced Chromosome Aberrations in Human Epithelial Cells: Radiation Quality and Dose Rate Effects

NASA Technical Reports Server (NTRS)

Hada, Megumi; Cucinotta, Francis; Wu, Honglu

2009-01-01

The advantage of the multicolor banding in situ hybridization (mBAND) technique is its ability to identify both inter- (translocation to unpainted chromosomes) and intra- (inversions and deletions within a single painted chromosome) chromosome aberrations simultaneously. To study the detailed rearrangement of low- and high-LET radiation induced chromosome aberrations in human epithelial cells (CH184B5F5/M10) in vitro, we performed a series of experiments with Cs-137 gamma rays of both low and high dose rates, neutrons of low dose rate and 600 MeV/u Fe ions of high dose rate, with chromosome 3 painted with multi-binding colors. We also compared the chromosome aberrations in both 2- and 3-dimensional cell cultures. Results of these experiments revealed the highest chromosome aberration frequencies after low dose rate neutron exposures. However, detailed analysis of the radiation induced inversions revealed that all three radiation types induced a low incidence of simple inversions. Most of the inversions in gamma-ray irradiated samples were accompanied by other types of intra-chromosomal aberrations but few inversions were accompanied by inter-chromosomal aberrations. In contrast, neutrons and Fe ions induced a significant fraction of inversions that involved complex rearrangements of both inter- and intrachromosomal exchanges. The location of the breaks involved in chromosome exchanges was analyzed along the painted chromosome. The breakpoint distribution was found to be randomly localized on chromosome 3 after neutron or Fe ion exposure, whereas non-random distribution with clustering breakpoints was observed after -ray exposure. Our comparison of chromosome aberration yields between 2- and 3-dimensional cell cultures indicated a significant difference for gamma exposures, but not for Fe ion exposures. These experimental results indicated that the track structure of the radiation and the cellular/chromosome structure can both affect radiation-induced chromosome aberrations.

Modelling spatially regulated beta-catenin dynamics and invasion in intestinal crypts.

PubMed

Murray, Philip J; Kang, Jun-Won; Mirams, Gary R; Shin, Sung-Young; Byrne, Helen M; Maini, Philip K; Cho, Kwang-Hyun

2010-08-04

Experimental data (e.g., genetic lineage and cell population studies) on intestinal crypts reveal that regulatory features of crypt behavior, such as control via morphogen gradients, are remarkably well conserved among numerous organisms (e.g., from mouse and rat to human) and throughout the different regions of the small and large intestines. In this article, we construct a partial differential equation model of a single colonic crypt that describes the spatial distribution of Wnt pathway proteins along the crypt axis. The novelty of our continuum model is that it is based upon assumptions that can be directly related to processes at the cellular and subcellular scales. We use the model to predict how the distributions of Wnt pathway proteins are affected by mutations. The model is then extended to investigate how mutant cell populations can invade neighboring crypts. The model simulations suggest that cell crowding caused by increased proliferation and decreased cell loss may be sufficient for a mutant cell population to colonize a neighboring healthy crypt. 2010 Biophysical Society. Published by Elsevier Inc. All rights reserved.

c-Myb is required for progenitor cell homeostasis in colonic crypts

PubMed Central

Malaterre, Jordane; Carpinelli, Marina; Ernst, Matthias; Alexander, Warren; Cooke, Michael; Sutton, Susan; Dworkin, Sebastian; Heath, Joan K.; Frampton, Jon; McArthur, Grant; Clevers, Hans; Hilton, Douglas; Mantamadiotis, Theo; Ramsay, Robert G.

2007-01-01

The colonic crypt is the functional unit of the colon mucosa with a central role in ion and water reabsorption. Under steady-state conditions, the distal colonic crypt harbors a single stem cell at its base that gives rise to highly proliferative progenitor cells that differentiate into columnar, goblet, and endocrine cells. The role of c-Myb in crypt homeostasis has not been elucidated. Here we have studied three genetically distinct hypomorphic c-myb mutant mouse strains, all of which show reduced colonic crypt size. The mutations target the key domains of the transcription factor: the DNA binding, transactivation, and negative regulatory domains. In vivo proliferation and cell cycle marker studies suggest that these mice have a progenitor cell proliferation defect mediated in part by reduced Cyclin E1 expression. To independently assess the extent to which c-myb is required for colonic crypt homeostasis we also generated a novel tissue-specific mouse model to allow the deletion of c-myb in adult colon, and using these mice we show that c-Myb is required for crypt integrity, normal differentiation, and steady-state proliferation. PMID:17360438

Origin of silicic crust by rifting and bimodal plume volcanism in the Afar Depression

NASA Astrophysics Data System (ADS)

Ghatak, A.; Basu, A. R.; Ebinger, C. J.

2010-12-01

The youngest mantle plume province worldwide occurs at the seismically and volcanically active East African - Red Sea - Gulf of Aden (Afar) triple junction, where one or more upwellings has impinged the thick cratonic lithosphere since ~45 Ma. A spectacular example of magmatism in the Afar depression is seen in the present to < 2 Ma old bimodal fissural mafic and peralkaline silicic eruptions in the ~60 km-long Dabbahu-Manda Hararo (DMH) Rift. In this study we report major, trace elements, and Nd-Sr-Pb isotopes in recent basaltic and silicic rocks originating from the center of the DMH rift segment, exposed along the rift axis and flanks of this segment. The rare earth element (REE) patterns of the silicic rocks and basalts are different in two significant ways: (1) the silicic rocks show a prominent positive Ce-anomaly that is extremely rare in volcanic rocks; and (2) this positive Ce-anomaly is accompanied by a strong negative Eu-anomaly. These anomalies are absent in the basaltic rocks. The positive Ce-anomaly is probably due to interaction in a magma chamber, similar in composition to the basalts, with deep saline aquifer or brines that typically show positive Ce-anomaly. The REE patterns of the two lava groups are interpreted to be due to fractional crystallization of plagioclase in a magma chamber similar in REE composition as the basalts that erupted in the DMH segments. We interpret the silicic rocks to be residues after ~20% fractional crystallization of plagioclase in the DMH basalts. The Nd-Pb isotopic composition of the basalts and rhyolites of the DMH are similar to the Ethiopian plume as defined by the ~30 Ma old Ethiopian flood basalts. Based on their high 3He/4He ratios (R/RA ~30) and Nd-Sr-Pb isotopic data, the source of the Ethiopian plume is generally believed to be in the lower mantle. Therefore, the similarity of the Nd-Pb and Pb-Pb isotopic variations between the Ethiopian plume and the DMH lavas indicates that these lavas were sourced from the lower mantle, and this source zone showed little variation over the past 30 Ma. Some of the silicic lavas fall distinctly outside the plume field toward more radiogenic 87Sr/86Sr at relatively restricted Nd and Pb isotopic compositions. This excursion in Sr-isotopic ratios of the silicic lavas, in concert with their positive Ce-anomaly, is interpreted to be due to mixing of the Afar plume derived basaltic magma with fluids from saline aquifers. We conclude that the bimodal lavas are consanguineous, the silicic lavas being generated by fractional crystallization of plagioclase in a lower mantle plume-derived basaltic magma-chamber, caused by the interaction with saline aquifers. The generation of bimodal volcanism from parental primitive basalts without any contribution from pre-existing continental crust in Dabbahu may explain other similar intraplate magmatism including early Archean-Hadean continental crust formation prior to onset of arc-volcanism.

Early and Late Chromosome Damages in Human Lymphocytes Induced by Gamma Rays and Fe Ions

NASA Technical Reports Server (NTRS)

Sunagawa, Mayumi; Zhang, Ye; Yeshitla, Samrawit; Kadhim, Munira; Wilson, Bobby; Wu, Honglu

2014-01-01

Chromosomal translocations and inversions are considered stable, and cells containing these types of chromosome aberrations can survive multiple cell divisions. An efficient method to detect an inversion is multi-color banding fluorescent in situ hybridization (mBAND) which allows identification of both inter- and intrachromosome aberrations simultaneously. Post irradiation, chromosome aberrations may also arise after multiple cell divisions as a result of genomic instability. To investigate the stable or late-arising chromosome aberrations induced after radiation exposure, we exposed human lymphocytes to gamma rays and Fe ions ex vivo, and cultured the cells for multiple generations. Chromosome aberrations were analyzed in cells collected at first mitosis and at several time intervals during the culture period post irradiation. With gamma irradiation, about half of the damages observed at first mitosis remained after 7 day- and 14 day- culture, suggesting the transmissibility of damages to the surviving progeny. Detailed analysis of chromosome break ends participating in exchanges revealed a greater fraction of break ends involved in intrachromosome aberrations in the 7- and 14-day samples in comparison to the fraction at first mitosis. In particular, simple inversions were found at 7 and 14 days, but not at the first mitosis, suggesting that some of the aberrations might be formed days post irradiation. In contrast, at the doses that produced similar frequencies of gamma-induced chromosome aberrations as observed at first mitosis, a significantly lower yield of aberrations remained at the same population doublings after Fe ion exposure. At these equitoxic doses, more complex type aberrations were observed for Fe ions, indicating that Fe ion-induced initial chromosome damages are more severe and may lead to cell death. Comparison between low and high doses of Fe ion irradiation in the induction of late damages will also be discussed.

Human alpha defensin 5 is a candidate biomarker to delineate inflammatory bowel disease

PubMed Central

Williams, Amanda D.; Korolkova, Olga Y.; Sakwe, Amos M.; Geiger, Timothy M.; James, Samuel D.; Muldoon, Roberta L.; Herline, Alan J.; Goodwin, J. Shawn; Izban, Michael G.; Washington, Mary K.; Smoot, Duane T.; Ballard, Billy R.; Gazouli, Maria

2017-01-01

Inability to distinguish Crohn's colitis from ulcerative colitis leads to the diagnosis of indeterminate colitis. This greatly effects medical and surgical care of the patient because treatments for the two diseases vary. Approximately 30 percent of inflammatory bowel disease patients cannot be accurately diagnosed, increasing their risk of inappropriate treatment. We sought to determine whether transcriptomic patterns could be used to develop diagnostic biomarker(s) to delineate inflammatory bowel disease more accurately. Four patients groups were assessed via whole-transcriptome microarray, qPCR, Western blot, and immunohistochemistry for differential expression of Human α-Defensin-5. In addition, immunohistochemistry for Paneth cells and Lysozyme, a Paneth cell marker, was also performed. Aberrant expression of Human α-Defensin-5 levels using transcript, Western blot, and immunohistochemistry staining levels was significantly upregulated in Crohn's colitis, p< 0.0001. Among patients with indeterminate colitis, Human α-Defensin-5 is a reliable differentiator with a positive predictive value of 96 percent. We also observed abundant ectopic crypt Paneth cells in all colectomy tissue samples of Crohn's colitis patients. In a retrospective study, we show that Human α-Defensin-5 could be used in indeterminate colitis patients to determine if they have either ulcerative colitis (low levels of Human α-Defensin-5) or Crohn's colitis (high levels of Human α-Defensin-5). Twenty of 67 patients (30 percent) who underwent restorative proctocolectomy for definitive ulcerative colitis were clinically changed to de novo Crohn's disease. These patients were profiled by Human α-Defensin-5 immunohistochemistry. All patients tested strongly positive. In addition, we observed by both hematoxylin and eosin and Lysozyme staining, a large number of ectopic Paneth cells in the colonic crypt of Crohn's colitis patient samples. Our experiments are the first to show that Human α-Defensin-5 is a potential candidate biomarker to molecularly differentiate Crohn's colitis from ulcerative colitis, to our knowledge. These data give us both a potential diagnostic marker in Human α-Defensin-5 and insight to develop future mechanistic studies to better understand crypt biology in Crohn's colitis. PMID:28817680

Role of serotonin in the intestinal mucosal epithelium barrier in weaning mice undergoing stress-induced diarrhea.

PubMed

Dong, Yulan; Wang, Zixu; Qin, Zhuoming; Cao, Jing; Chen, Yaoxing

2018-02-01

Stress-induced diarrhea is a frequent and challenging threat to humans and domestic animals. Serotonin (5-HT) has been shown to be involved in the pathological process of stress-induced diarrhea. However, the role of 5-HT in stress-induced diarrhea remains unclear. A stress-induced diarrhea model was established in 21-day-old ICR weaning mice through an intragastric administration of 0.25 mL of 0.4 g/mL folium sennae and restraint of the hind legs with adhesive tape for 4 h to determine whether 5-HT regulates the mucosal barrier to cause diarrhea. Mice with decreased levels of 5-HT were pretreated with an intraperitoneal injection of 300 mg/kg p-chlorophenylalanine (PCPA), a 5-HT synthesis inhibitor. After 5 days of treatment, the stress level, body weight and intestinal mucosal morphology indexes were measured. Compared to the controls, the mice with stress-induced diarrhea displayed a stress reaction, with increased corticosterone levels, as well as increased 5-HT-positive cells. However, the mice with stress-induced diarrhea exhibited decreased body weights, villus height to crypt depth ratios (V/C), and Occludin and Claudin1 expression. The PCPA injection reversed these effects in mice with different degrees of stress-induced diarrhea. Based on these findings, inhibition of 5-HT synthesis relieved the stress response and improved the health of the intestinal tract, including both the intestinal absorption capacity, as determined by the villus height and crypt depth, and the mucosal barrier function, as determined by the tight junction proteins of epithelial cell.

A calibrated agent-based computer model of stochastic cell dynamics in normal human colon crypts useful for in silico experiments.

PubMed

Bravo, Rafael; Axelrod, David E

2013-11-18

Normal colon crypts consist of stem cells, proliferating cells, and differentiated cells. Abnormal rates of proliferation and differentiation can initiate colon cancer. We have measured the variation in the number of each of these cell types in multiple crypts in normal human biopsy specimens. This has provided the opportunity to produce a calibrated computational model that simulates cell dynamics in normal human crypts, and by changing model parameter values, to simulate the initiation and treatment of colon cancer. An agent-based model of stochastic cell dynamics in human colon crypts was developed in the multi-platform open-source application NetLogo. It was assumed that each cell's probability of proliferation and probability of death is determined by its position in two gradients along the crypt axis, a divide gradient and in a die gradient. A cell's type is not intrinsic, but rather is determined by its position in the divide gradient. Cell types are dynamic, plastic, and inter-convertible. Parameter values were determined for the shape of each of the gradients, and for a cell's response to the gradients. This was done by parameter sweeps that indicated the values that reproduced the measured number and variation of each cell type, and produced quasi-stationary stochastic dynamics. The behavior of the model was verified by its ability to reproduce the experimentally observed monocolonal conversion by neutral drift, the formation of adenomas resulting from mutations either at the top or bottom of the crypt, and by the robust ability of crypts to recover from perturbation by cytotoxic agents. One use of the virtual crypt model was demonstrated by evaluating different cancer chemotherapy and radiation scheduling protocols. A virtual crypt has been developed that simulates the quasi-stationary stochastic cell dynamics of normal human colon crypts. It is unique in that it has been calibrated with measurements of human biopsy specimens, and it can simulate the variation of cell types in addition to the average number of each cell type. The utility of the model was demonstrated with in silico experiments that evaluated cancer therapy protocols. The model is available for others to conduct additional experiments.

Long-term culture-induced phenotypic difference and efficient cryopreservation of small intestinal organoids by treatment timing of Rho kinase inhibitor.

PubMed

Han, Sung-Hoon; Shim, Sehwan; Kim, Min-Jung; Shin, Hye-Yun; Jang, Won-Suk; Lee, Sun-Joo; Jin, Young-Woo; Lee, Seung-Sook; Lee, Seung Bum; Park, Sunhoo

2017-02-14

To investigate a suitable long-term culture system and optimal cryopreservation of intestinal organoid to improve organoid-based therapy by acquiring large numbers of cells. Crypts were isolated from jejunum of C57BL/6 mouse. Two hundred crypts were cultured in organoid medium with either epidermal growth factor/Noggin/R-spondin1 (ENR) or ENR/CHIR99021/VPA (ENR-CV). For subculture, organoids cultured on day 7 were passaged using enzyme-free cell dissociation buffer (STEMCELL Technologies). The passage was performed once per week until indicated passage. For cryopreservation, undissociated and dissociated organoids were resuspended in freezing medium with or without Rho kinase inhibitor subjected to different treatment times. The characteristics of intestinal organoids upon extended passage and freeze-thaw were analyzed using EdU staining, methyl thiazolyl tetrazolium assay, qPCR and time-lapse live cell imaging. We established a three-dimensional culture system for murine small intestinal organoids using ENR and ENR-CV media. Both conditions yielded organoids with a crypt-villus architecture exhibiting Lgr5 + cells and differentiated intestinal epithelial cells as shown by morphological and biochemical analysis. However, during extended passage (more than 3 mo), a comparative analysis revealed that continuous passaging under ENR-CV conditions, but not ENR conditions induced phenotypic changes as observed by morphological transition, reduced numbers of Lgr5 + cells and inconsistent expression of markers for differentiated intestinal epithelial cell types. We also found that recovery of long-term cryopreserved organoids was significantly affected by the organoid state, i.e ., whether dissociation was applied, and the timing of treatment with the Rho-kinase inhibitor Y-27632. Furthermore, the retention of typical morphological characteristics of intestinal organoids such as the crypt-villus structure from freeze-thawed cells was observed by live cell imaging. The maintenance of the characteristics of intestinal organoids upon extended passage is mediated by ENR condition, but not ENR-CV condition. Identified long-term cryopreservation may contribute to the establishment of standardized cryopreservation protocols for intestinal organoids for use in clinical applications.

Dynamic accommodation with simulated targets blurred with high order aberrations

PubMed Central

Gambra, Enrique; Wang, Yinan; Yuan, Jing; Kruger, Philip B.; Marcos, Susana

2010-01-01

High order aberrations have been suggested to play a role in determining the direction of accommodation. We have explored the effect of retinal blur induced by high order aberrations on dynamic accommodation by measuring the accommodative response to sinusoidal variations in accommodative demand (1–3 D). The targets were blurred with 0.3 and 1 μm (for a 3-mm pupil) of defocus, coma, trefoil and spherical aberration. Accommodative gain decreased significantly when 1-μm of aberration was induced. We found a strong correlation between the relative accommodative gain (and phase lag) and the contrast degradation imposed on the target at relevant spatial frequencies. PMID:20600230

Influence of incorporated bromodeoxyuridine on the induction of chromosomal alterations by ionizing radiation and long-wave UV in CHO cells.

PubMed

Zwanenburg, T S; van Zeeland, A A; Natarajan, A T

1985-01-01

Incorporation of BrdUrd into nuclear DNA sensitizes CHO cells (1) to the induction of chromosomal aberrations by X-rays and 0.5 MeV neutrons and (2) to induction of chromosomal aberrations and SCEs by lw-UV. We have attempted to establish a correlation between induced chromosomal alterations and induced single- or double-strand breaks in DNA. The data show that while DSBs correlate very well with X-ray-induced aberrations, no clear correlation could be established between lw-UV induced SSBs (including alkali-labile sites) and chromosomal alterations. In addition the effect of 3-aminobenzamide (3AB) on the induction of chromosomal aberrations and SCEs induced by lw-UV has been determined. It is shown that 3AB is without any effect when lw-UV-irradiated cells are posttreated with this inhibitor. The significance of these results is discussed.

Chronic Nicotine Mitigates Aberrant Inhibitory Motor Learning Induced by Motor Experience under Dopamine Deficiency

PubMed Central

Krok, Anne C.; Xu, Jian; Contractor, Anis; McGehee, Daniel S.; Zhuang, Xiaoxi

2016-01-01

Although dopamine receptor antagonism has long been associated with impairments in motor performance, more recent studies have shown that dopamine D2 receptor (D2R) antagonism, paired with a motor task, not only impairs motor performance concomitant with the pharmacodynamics of the drug, but also impairs future motor performance once antagonism has been relieved. We have termed this phenomenon “aberrant motor learning” and have suggested that it may contribute to motor symptoms in movement disorders such as Parkinson's disease (PD). Here, we show that chronic nicotine (cNIC), but not acute nicotine, treatment mitigates the acquisition of D2R-antagonist-induced aberrant motor learning in mice. Although cNIC mitigates D2R-mediated aberrant motor learning, cNIC has no effect on D1R-mediated motor learning. β2-containing nicotinic receptors in dopamine neurons likely mediate the protective effect of cNIC against aberrant motor learning, because selective deletion of β2 nicotinic subunits in dopamine neurons reduced D2R-mediated aberrant motor learning. Finally, both cNIC treatment and β2 subunit deletion blunted postsynaptic responses to D2R antagonism. These results suggest that a chronic decrease in function or a downregulation of β2-containing nicotinic receptors protects the striatal network against aberrant plasticity and aberrant motor learning induced by motor experience under dopamine deficiency. SIGNIFICANCE STATEMENT Increasingly, aberrant plasticity and aberrant learning are recognized as contributing to the development and progression of movement disorders. Here, we show that chronic nicotine (cNIC) treatment or specific deletion of β2 nicotinic receptor subunits in dopamine neurons mitigates aberrant motor learning induced by dopamine D2 receptor (D2R) blockade in mice. Moreover, both manipulations also reduced striatal dopamine release and blunt postsynaptic responses to D2R antagonists. These results suggest that chronic downregulation of function and/or receptor expression of β2-containing nicotinic receptors alters presynaptic and postsynaptic striatal signaling to protect against aberrant motor learning. Moreover, these results suggest that cNIC treatment may alleviate motor symptoms and/or delay the deterioration of motor function in movement disorders by blocking aberrant motor learning. PMID:27170121

Computational Models Reveal a Passive Mechanism for Cell Migration in the Crypt

PubMed Central

Dunn, Sara-Jane; Näthke, Inke S.; Osborne, James M.

2013-01-01

Cell migration in the intestinal crypt is essential for the regular renewal of the epithelium, and the continued upward movement of cells is a key characteristic of healthy crypt dynamics. However, the driving force behind this migration is unknown. Possibilities include mitotic pressure, active movement driven by motility cues, or negative pressure arising from cell loss at the crypt collar. It is possible that a combination of factors together coordinate migration. Here, three different computational models are used to provide insight into the mechanisms that underpin cell movement in the crypt, by examining the consequence of eliminating cell division on cell movement. Computational simulations agree with existing experimental results, confirming that migration can continue in the absence of mitosis. Importantly, however, simulations allow us to infer mechanisms that are sufficient to generate cell movement, which is not possible through experimental observation alone. The results produced by the three models agree and suggest that cell loss due to apoptosis and extrusion at the crypt collar relieves cell compression below, allowing cells to expand and move upwards. This finding suggests that future experiments should focus on the role of apoptosis and cell extrusion in controlling cell migration in the crypt. PMID:24260407

Effect of antisecretory agents and vagotomy on healing of chronic cysteamine-induced duodenal ulcers in rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poulsen, S.S.; Raaberg, L.; Therkelsen, K.

1986-07-01

Penetrated cysteamine-induced duodenal ulcers in rats have a very prolonged course of healing. In this study, it was investigated how much the healing of these ulcers is accelerated by some treatments. The treatments included omeprazole, cimetidine, and truncal vagotomy. In addition, the effect of omeprazole and cimetidine on gastric acid secretion was investigated in chronic gastric fistula rats. After 25 days of treatment, significantly more rats in the treated groups had healed ulcers than in the control group. There was little further improvement up to 100 days of treatment, and the difference between treated and untreated groups decreased. The morphologymore » of healing ulcers in treated and untreated rats was also compared. In controls, there was a simultaneous regeneration of mucosa and the submucosal Brunner's glands from the edges of the ulcer, the slow proliferation rate of the latter probably being decisive for the prolonged healing. In the treated rats, the mucosa first regenerated with formation of crypts and low villi and subsequently, the Brunner's glands were formed by proliferation from the bottom of the crypts.« less

mBAND Analysis of Late Chromosome Aberrations in Human Lymphocytes Induced by Gamma Rays and Fe Ions

NASA Technical Reports Server (NTRS)

Sunagawa, Mayumi; Zhang, Ye; Yeshitla, Samrawit; Kadhim, Munira; Wilson, Bobby; Wu, Honglu

2014-01-01

Chromosomal translocations and inversions are considered stable, and cells containing these types of chromosome aberrations can survive multiple cell divisions. An efficient method to detect an inversion is multi-color banding fluorescent in situ hybridization (mBAND) which allows identification of both inter- and intrachromosome aberrations simultaneously. Post irradiation, chromosome aberrations may also arise after multiple cell divisions as a result of genomic instability. To investigate the stable or late-arising chromosome aberrations induced after radiation exposure, we exposed human lymphocytes to gamma rays and Fe ions ex vivo, and cultured the cells for multiple generations. Chromosome aberrations were analyzed in cells collected at first mitosis and at several time intervals during the culture period post irradiation. With gamma irradiation, about half of the damages observed at first mitosis remained after 7 day- and 14 day- culture, suggesting the transmissibility of damages to the surviving progeny. Detailed analysis of chromosome break ends participating in exchanges revealed a greater fraction of break ends involved in intrachromosome aberrations in the 7- and 14-day samples in comparison to the fraction at first mitosis. In particular, simple inversions were found at 7 and 14 days, but not at the first mitosis, suggesting that some of the aberrations might be formed days post irradiation. In contrast, at the doses that produced similar frequencies of gamma-induced chromosome aberrations as observed at first mitosis, a significantly lower yield of aberrations remained at the same population doublings after Fe ion exposure. At these equitoxic doses, more complex type aberrations were observed for Fe ions, indicating that Fe ion-induced initial chromosome damages are more severe and may lead to cell death. Comparison between low and high doses of Fe ion irradiation in the induction of late damages will also be discussed.

Resistant starch: a functional food that prevents DNA damage and chemical carcinogenesis.

PubMed

Navarro, S D; Mauro, M O; Pesarini, J R; Ogo, F M; Oliveira, R J

2015-03-06

Resistant starch is formed from starch and its degradation products and is not digested or absorbed in the intestine; thus, it is characterized as a fiber. Because fiber intake is associated with the prevention of DNA damage and cancer, the potential antigenotoxic, antimutagenic, and anticarcinogenic capabilities of resistant starch from green banana flour were evaluated. Animals were treated with 1,2-dimethylhydrazine and their diet was supplemented with 10% green banana flour according to the following resistant starch protocols: pretreatment, simultaneous treatment, post-treatment, and pre + continuous treatment. The results demonstrated that resistant starch is not genotoxic, mutagenic, or carcinogenic. The results suggest that resistant starch acts through desmutagenesis and bio-antimutagenesis, as well as by reducing aberrant crypt foci, thereby improving disease prognosis. These findings imply that green banana flour has therapeutic properties that should be explored for human dietary applications.

Modelling the spatio-temporal cell dynamics reveals novel insights on cell differentiation and proliferation in the small intestinal crypt.

PubMed

Pin, Carmen; Watson, Alastair J M; Carding, Simon R

2012-01-01

We developed a slow structural relaxation model to describe cellular dynamics in the crypt of the mouse small intestine. Cells are arranged in a three dimensional spiral the size of which dynamically changes according to cell production demands of adjacent villi. Cell differentiation and proliferation is regulated through Wnt and Notch signals, the strength of which depends on the local cell composition. The highest level of Wnt activity is associated with maintaining equipotent stem cells (SC), Paneth cells and common goblet-Paneth cell progenitors (CGPCPs) intermingling at the crypt bottom. Low levels of Wnt signalling area are associated with stem cells giving rise to secretory cells (CGPCPs, enteroendocrine or Tuft cells) and proliferative absorptive progenitors. Deciding between these two fates, secretory and stem/absorptive cells, depends on Notch signalling. Our model predicts that Notch signalling inhibits secretory fate if more than 50% of cells they are in contact with belong to the secretory lineage. CGPCPs under high Wnt signalling will differentiate into Paneth cells while those migrating out from the crypt bottom differentiate into goblet cells. We have assumed that mature Paneth cells migrating upwards undergo anoikis. Structural relaxation explains the localisation of Paneth cells to the crypt bottom in the absence of active forces. The predicted crypt generation time from one SC is 4-5 days with 10-12 days needed to reach a structural steady state. Our predictions are consistent with experimental observations made under altered Wnt and Notch signalling. Mutations affecting stem cells located at the crypt floor have a 50% chance of being propagated throughout the crypt while mutations in cells above are rarely propagated. The predicted recovery time of an injured crypt losing half of its cells is approximately 2 days.

CPT-11-Induced Delayed Diarrhea Develops via Reduced Aquaporin-3 Expression in the Colon

PubMed Central

Kon, Risako; Tsubota, Yuika; Minami, Moe; Kato, Saki; Matsunaga, Yukari; Kimura, Hiroshi; Murakami, Yuta; Fujikawa, Tetsuya; Sakurai, Ryoya; Tomimoto, Rei; Machida, Yoshiaki; Ikarashi, Nobutomo; Sugiyama, Kiyoshi

2018-01-01

While irinotecan (CPT-11) has a potent anti-cancer effect, it also causes serious diarrhea as an adverse reaction. In this study, we analyzed the pathogenic mechanism of CPT-11-induced delayed diarrhea by focusing on water channel aquaporin-3 (AQP3) in the colon. When rats received CPT-11, the expression level of AQP3 was reduced during severe diarrhea. It was found that the expression levels of inflammatory cytokines and the loss of crypt cells were increased in the colon when CPT-11 was administered. When celecoxib, an anti-inflammatory drug, was concomitantly administered, both the diarrhea and the reduced expression of AQP3 induced by CPT-11 were suppressed. The inflammation in the rat colon during diarrhea was caused via activated macrophage by CPT-11. These results showed that when CPT-11 is administered, the expression level of AQP3 in the colon is reduced, resulting in delayed diarrhea by preventing water transport from the intestinal tract. It was also suggested that the reduced expression of AQP3 might be due to the inflammation that occurs following the loss of colonic crypt cells and to the damage caused by the direct activation of macrophages by CPT-11. Therefore, it was considered that anti-inflammatory drugs that suppress the reduction of AQP3 expression could prevent CPT-11-induced delayed diarrhea. PMID:29316651

CPT-11-Induced Delayed Diarrhea Develops via Reduced Aquaporin-3 Expression in the Colon.

PubMed

Kon, Risako; Tsubota, Yuika; Minami, Moe; Kato, Saki; Matsunaga, Yukari; Kimura, Hiroshi; Murakami, Yuta; Fujikawa, Tetsuya; Sakurai, Ryoya; Tomimoto, Rei; Machida, Yoshiaki; Ikarashi, Nobutomo; Sugiyama, Kiyoshi

2018-01-06

While irinotecan (CPT-11) has a potent anti-cancer effect, it also causes serious diarrhea as an adverse reaction. In this study, we analyzed the pathogenic mechanism of CPT-11-induced delayed diarrhea by focusing on water channel aquaporin-3 (AQP3) in the colon. When rats received CPT-11, the expression level of AQP3 was reduced during severe diarrhea. It was found that the expression levels of inflammatory cytokines and the loss of crypt cells were increased in the colon when CPT-11 was administered. When celecoxib, an anti-inflammatory drug, was concomitantly administered, both the diarrhea and the reduced expression of AQP3 induced by CPT-11 were suppressed. The inflammation in the rat colon during diarrhea was caused via activated macrophage by CPT-11. These results showed that when CPT-11 is administered, the expression level of AQP3 in the colon is reduced, resulting in delayed diarrhea by preventing water transport from the intestinal tract. It was also suggested that the reduced expression of AQP3 might be due to the inflammation that occurs following the loss of colonic crypt cells and to the damage caused by the direct activation of macrophages by CPT-11. Therefore, it was considered that anti-inflammatory drugs that suppress the reduction of AQP3 expression could prevent CPT-11-induced delayed diarrhea.

SU-G-BRC-08: Evaluation of Dose Mass Histogram as a More Representative Dose Description Method Than Dose Volume Histogram in Lung Cancer Patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, J; Eldib, A; Ma, C

2016-06-15

Purpose: Dose-volume-histogram (DVH) is widely used for plan evaluation in radiation treatment. The concept of dose-mass-histogram (DMH) is expected to provide a more representative description as it accounts for heterogeneity in tissue density. This study is intended to assess the difference between DVH and DMH for evaluating treatment planning quality. Methods: 12 lung cancer treatment plans were exported from the treatment planning system. DVHs for the planning target volume (PTV), the normal lung and other structures of interest were calculated. DMHs were calculated in a similar way as DVHs expect that the voxel density converted from the CT number wasmore » used in tallying the dose histogram bins. The equivalent uniform dose (EUD) was calculated based on voxel volume and mass, respectively. The normal tissue complication probability (NTCP) in relation to the EUD was calculated for the normal lung to provide quantitative comparison of DVHs and DMHs for evaluating the radiobiological effect. Results: Large differences were observed between DVHs and DMHs for lungs and PTVs. For PTVs with dense tumor cores, DMHs are higher than DVHs due to larger mass weighing in the high dose conformal core regions. For the normal lungs, DMHs can either be higher or lower than DVHs depending on the target location within the lung. When the target is close to the lower lung, DMHs show higher values than DVHs because the lower lung has higher density than the central portion or the upper lung. DMHs are lower than DVHs for targets in the upper lung. The calculated NTCPs showed a large range of difference between DVHs and DMHs. Conclusion: The heterogeneity of lung can be well considered using DMH for evaluating target coverage and normal lung pneumonitis. Further studies are warranted to quantify the benefits of DMH over DVH for plan quality evaluation.« less

Thymoquinone potentiates chemoprotective effect of Vitamin D3 against colon cancer: a pre-clinical finding

PubMed Central

Mohamed, Amr M; Refaat, Bassem A; El-Shemi, Adel G; Kensara, Osama A; Ahmad, Jawwad; Idris, Shakir

2017-01-01

Prevention of colon cancer among high-risk group has been long lasting research goal. Emerging data have evidenced the anticancer activities of Vitamin D3 (Vit.D) and Thymoquinone (TQ). The aim of the current study was to evaluate the synergistic potential of Thymoquinone and Vitamin D3 in the control of colon cancer progression using azoxymethane-induced rat model. Vit.D and TQ were given individually or in combination 4 week prior to induction and continued for a total of 20 week. At the end of the study, all animals were euthanized and their resected colons were examined macroscopically and microscopically for tumor growth. Colonic tissue preparations were used for measuring gene expression and/or protein levels of selected pro and anti-tumor biomarkers using quantitative RT-PCR, ELISA and immunohistochemistry. Compared with their individual supplementation, combined Vit.D/TQ showed prominent anti-tumor effect manifested by significant reduction (P < 0.05) of the numbers of grown tumors and large aberrant crypts foci. Mechanistically, gene expression and/or protein quantification studies revealed that combined Vit.D/TQ supplementation induced significant reduction (P < 0.01 and P < 0.05) of pro-cancerous molecules (Wnt, β-catenin, NF-κB, COX-2, iNOS, VEGF and HSP-90) as well as significant increase (P < 0.01 and P < 0.05, respectively) of anti-tumorigenesis biomarkers (DKK-1, CDNK-1A, TGF-β1, TGF-β/RII and smad4) as compared to un-supplemented or individually supplemented groups, respectively. In conclusion, TQ augmented the chemopreventive effect of Vit.D during the initiation phase of colon cancer in rat model, with the potential to suppress progression of pre-neoplastic lesions in colon carcinogenesis. PMID:28337306

Combined inadequacies of multiple B vitamins amplify colonic Wnt signaling and promote intestinal tumorigenesis in BAT-LacZ×Apc1638N mice

PubMed Central

Liu, Zhenhua; Ciappio, Eric D.; Crott, Jimmy W.; Brooks, Ryan S.; Nesvet, Jared; Smith, Donald E.; Choi, Sang-Woon; Mason, Joel B.

2011-01-01

The Wnt pathway is a pivotal signaling cascade in colorectal carcinogenesis. The purpose of this work is to determine whether depletion of folate and other metabolically related B vitamins induces in vivo activation of intestinal Wnt signaling and whether this occurs in parallel with increased tumorigenesis. A hybrid mouse was created by crossing a Wnt-reporter animal (BAT-LacZ) with a model of colorectal cancer (Apc1638N). A mild depletion of folate and vitamins B2, B6, and B12 was induced over 16 wk, and the control animals in each instance were pair fed a diet containing the basal requirement of these nutrients. The multiplicity of macroscopic tumors and aberrant crypt foci both increased by ∼50% in the hybrid mice fed the depletion diet (P<0.05). A 4-fold elevation in Wnt signaling was produced by the depletion diet (P<0.05) and was accompanied by significant changes in the expression of a number of Wnt-related genes in a pattern consistent with its activation. Proliferation and apoptosis of the colonic mucosa both changed in a protransformational direction (P<0.05). In summary, mild depletion of multiple B vitamins produces in vivo activation of colonic Wnt signaling, implicating it as a key pathway by which B-vitamin inadequacies enhance intestinal tumorigenesis.—Liu, Z., Ciappio, E. D., Crott, J. W., Brooks, R. S., Nesvet, J., Smith, D. E., Choi, S.-W., Mason, J. B. Combined inadequacies of multiple B vitamins amplify colonic Wnt signaling and promote intestinal tumorigenesis in BAT-LacZ×Apc1638N mice. PMID:21646397

CHEMOPREVENTIVE EFFICACY OF NAPROXEN AND NO-NAPROXEN IN RODENT MODELS OF COLON, URINARY BLADDER, AND MAMMARY CANCERS

PubMed Central

Steele, Vernon E.; Rao, Chinthalapally V.; Zhang, Yuting; Patlolla, Jagan; Boring, Daniel; Kopelovich, Levy; Juliana, M. Margaret; Grubbs, Clinton J.; Lubet, Ronald A.

2009-01-01

Nonsteroidal anti-inflammatory drugs (NSAIDs) have been highly effective in preventing colon, urinary bladder, and skin cancer preclinically; and also in clinical trials of colon adenoma formation. However, certain NSAIDs cause gastrointestinal (GI) ulceration and may increase cardiovascular (CV) events. Naproxen appears to cause the lowest CV events of the common NSAIDs other than aspirin. NO-naproxen was tested based on the finding that adding a nitric oxide (NO) group to NSAIDs may help alleviate GI toxicity. In the azoxymethane (AOM)-induced rat colon aberrant crypt foci (ACF) model, naproxen administered at 200 and 400 ppm in the diet reduced mean ACFs in the colon by about 45–60%, respectively. NO-naproxen was likewise administered in the diet at roughly equimolar doses (300 and 600 ppm), and reduced total ACF by 20–40%, respectively. In the hydroxybutyl (butyl) nitrosamine (OH-BBN) rat urinary bladder cancer model, NO-naproxen was given at 183 ppm or 550 ppm in the diet, and naproxen at 128 ppm. The NO-naproxen groups had 77% and 73% decreases, respectively, in the development of large urinary bladder tumors, while the 128 ppm naproxen group also showed a strong decrease (69%). If treatments were started three months after OH-BBN, NO-naproxen (550 ppm) and naproxen (400 ppm) were also highly effective (86–94% decreases). In the methylnitrosourea (MNU)-induced mammary cancer model in rats, NO-naproxen and naproxen showed non-significant inhibitions (12 and 24%) at 550 and 400 ppm, respectively. These data show that both naproxen and NO-naproxen are effective agents against urinary bladder and colon, but not mammary, carcinogenesis. PMID:19892664

Inhibition of colon carcinogenesis by a standardized Cannabis sativa extract with high content of cannabidiol.

PubMed

Romano, Barbara; Borrelli, Francesca; Pagano, Ester; Cascio, Maria Grazia; Pertwee, Roger G; Izzo, Angelo A

2014-04-15

Colon cancer is a major public health problem. Cannabis-based medicines are useful adjunctive treatments in cancer patients. Here, we have investigated the effect of a standardized Cannabis sativa extract with high content of cannabidiol (CBD), here named CBD BDS, i.e. CBD botanical drug substance, on colorectal cancer cell proliferation and in experimental models of colon cancer in vivo. Proliferation was evaluated in colorectal carcinoma (DLD-1 and HCT116) as well as in healthy colonic cells using the MTT assay. CBD BDS binding was evaluated by its ability to displace [(3)H]CP55940 from human cannabinoid CB1 and CB2 receptors. In vivo, the effect of CBD BDS was examined on the preneoplastic lesions (aberrant crypt foci), polyps and tumours induced by the carcinogenic agent azoxymethane (AOM) as well as in a xenograft model of colon cancer in mice. CBD BDS and CBD reduced cell proliferation in tumoral, but not in healthy, cells. The effect of CBD BDS was counteracted by selective CB1 and CB2 receptor antagonists. Pure CBD reduced cell proliferation in a CB1-sensitive antagonist manner only. In binding assays, CBD BDS showed greater affinity than pure CBD for both CB1 and CB2 receptors, with pure CBD having very little affinity. In vivo, CBD BDS reduced AOM-induced preneoplastic lesions and polyps as well as tumour growth in the xenograft model of colon cancer. CBD BDS attenuates colon carcinogenesis and inhibits colorectal cancer cell proliferation via CB1 and CB2 receptor activation. The results may have some clinical relevance for the use of Cannabis-based medicines in cancer patients. Copyright © 2013 Elsevier GmbH. All rights reserved.

Acidic polysaccharide of Panax ginseng regulates the mitochondria/caspase-dependent apoptotic pathway in radiation-induced damage to the jejunum in mice.

PubMed

Bing, So Jin; Kim, Min Ju; Ahn, Ginnae; Im, Jaehak; Kim, Dae Seung; Ha, Danbee; Cho, Jinhee; Kim, Areum; Jee, Youngheun

2014-04-01

Owing to its susceptibility to radiation, the small intestine of mice is valuable for studying radioprotective effects. When exposed to radiation, intestinal crypt cells immediately go through apoptosis, which impairs swift differentiation necessary for the regeneration of intestinal villi. Our previous studies have elucidated that acidic polysaccharide of Panax ginseng (APG) protects the mouse small intestine from radiation-induced damage by lengthening villi with proliferation and repopulation of crypt cells. In the present study, we identified the molecular mechanism involved. C57BL/6 mice were irradiated with gamma-rays with or without APG and the expression levels of apoptosis-related molecules in the jejunum were investigated using immunohistochemistry. APG pretreatment strongly decreased the radiation-induced apoptosis in the jejunum. It increased the expression levels of anti-apoptotic proteins (Bcl-2 and Bcl-XS/L) and dramatically reduced the expression levels of pro-apoptotic proteins (p53, BAX, cytochrome c and caspase-3). Therefore, APG attenuated the apoptosis through the intrinsic pathway, which is controlled by p53 and Bcl-2 family members. Results presented in this study suggest that APG protects the mouse small intestine from irradiation-induced apoptosis through inhibition of the p53-dependent pathway and the mitochondria/caspase pathway. Thus, APG may be a potential agent for preventing radiation induced injuries in intestinal cells during radio-therapy such as in cancer treatment. Copyright © 2013 Elsevier GmbH. All rights reserved.

Murine P-glycoprotein Deficiency Alters Intestinal Injury Repair and Blunts Lipopolysaccharide-Induced Radioprotection

PubMed Central

Staley, Elizabeth M.; Yarbrough, Vanisha R.; Schoeb, Trenton R.; Daft, Joseph G.; Tanner, Scott M.; Steverson, Dennis; Lorenz, Robin G.

2012-01-01

P-glycoprotein (P-gp) has been reported to increase stem cell proliferation and regulate apoptosis. Absence of P-gp results in decreased repair of intestinal epithelial cells after chemical injury. To further explore the mechanisms involved in the effects of P-gp on intestinal injury and repair, we used the well-characterized radiation injury model. In this model, injury repair is mediated by production of prostaglandins (PGE2) and lipopolysaccharide (LPS) has been shown to confer radioprotection. B6.mdr1a−/− mice and wild-type controls were subjected to 12 Gy total body X-ray irradiation and surviving crypts in the proximal jejunum and distal colon were evaluated 3.5 days after irradiation. B6.mdr1a−/−mice exhibited normal baseline stem cell proliferation and COX dependent crypt regeneration after irradiation. However, radiation induced apoptosis was increased and LPS-induced radioprotection was blunted in the C57BL6.mdr1a−/−distal colon, compared to B6 wild-type controls. The LPS treatment induced gene expression of the radioprotective cytokine IL-1α, in B6 wild-type controls but not in B6.mdr1a−/− animals. Lipopolysaccharid-induced radioprotection was absent in IL-1R1−/− animals, indicating a role for IL-1α in radioprotection, and demonstrating that P-gp deficiency interferes with IL-1α gene expression in response to systemic exposure to LPS. PMID:22780103

Intermittent fasting prompted recovery from dextran sulfate sodium-induced colitis in mice.

PubMed

Okada, Toshihiko; Otsubo, Takeshi; Hagiwara, Teruki; Inazuka, Fumika; Kobayashi, Eiko; Fukuda, Shinji; Inoue, Takuya; Higuchi, Kazuhide; Kawamura, Yuki I; Dohi, Taeko

2017-09-01

Fasting-refeeding in mice induces transient hyperproliferation of colonic epithelial cells, which is dependent on the lactate produced as a metabolite of commensal bacteria. We attempted to manipulate colonic epithelial cell turnover with intermittent fasting to prompt recovery from acute colitis. Acute colitis was induced in C57BL/6 mice by administration of dextran sulfate sodium in the drinking water for 5 days. From day 6, mice were fasted for 36 h and refed normal bait, glucose powder, or lactylated high-amylose starch. On day 9, colon tissues were subjected to analysis of histology and cytokine expression. The effect of lactate on the proliferation of colonocytes was assessed by enema in vivo and primary culture in vitro . Intermittent fasting resulted in restored colonic crypts and less expression of interleukin-1β and interleukin-17 in the colon than in mice fed ad libitum . Administration of lactate in the colon at refeeding time by enema or by feeding lactylated high-amylose starch increased the number of regenerating crypts. Addition of lactate but not butyrate or acetate supported colony formation of colonocytes in vitro . In conclusion, intermittent fasting in the resolution phase of acute colitis resulted in better recovery of epithelial cells and reduced inflammation.

Bardoxolone Methyl Prevents High-Fat Diet-Induced Colon Inflammation in Mice.

PubMed

Dinh, Chi H L; Yu, Yinghua; Szabo, Alexander; Zhang, Qingsheng; Zhang, Peng; Huang, Xu-Feng

2016-04-01

Obesity induces chronic, low-grade inflammation, which increases the risk of colon cancer. We investigated the preventive effects of Bardoxolone methyl (BARD) on high-fat diet (HFD)-induced inflammation in a mouse colon. Male C57BL/6J mice (n=7) were fed a HFD (HFD group), HFD plus BARD (10 mg/kg) in drinking water (HFD/BARD group), or normal laboratory chow diet (LFD group) for 21 weeks. In HFD mice, BARD reduced colon thickness and decreased colon weight per length. This was associated with an increase in colon crypt depth and the number of goblet cells per crypt. BARD reduced the expression of F4/80 and CD11c but increased CD206 and IL-10, indicating an anti-inflammatory effect. BARD prevented an increase of the intracellular pro-inflammatory biomarkers (NF-қB, p NF-қB, IL-6, TNF-α) and cell proliferation markers (Cox2 and Ki67). BARD prevented fat deposition in the colon wall and prevented microbial population changes. Overall, we report the preventive effects of BARD on colon inflammation in HFD-fed mice through its regulation of macrophages, NF-қB, cytokines, Cox2 and Ki67, fat deposition and microflora. © 2016 The Histochemical Society.

Intermittent fasting prompted recovery from dextran sulfate sodium-induced colitis in mice

PubMed Central

Okada, Toshihiko; Otsubo, Takeshi; Hagiwara, Teruki; Inazuka, Fumika; Kobayashi, Eiko; Fukuda, Shinji; Inoue, Takuya; Higuchi, Kazuhide; Kawamura, Yuki I.; Dohi, Taeko

2017-01-01

Fasting-refeeding in mice induces transient hyperproliferation of colonic epithelial cells, which is dependent on the lactate produced as a metabolite of commensal bacteria. We attempted to manipulate colonic epithelial cell turnover with intermittent fasting to prompt recovery from acute colitis. Acute colitis was induced in C57BL/6 mice by administration of dextran sulfate sodium in the drinking water for 5 days. From day 6, mice were fasted for 36 h and refed normal bait, glucose powder, or lactylated high-amylose starch. On day 9, colon tissues were subjected to analysis of histology and cytokine expression. The effect of lactate on the proliferation of colonocytes was assessed by enema in vivo and primary culture in vitro. Intermittent fasting resulted in restored colonic crypts and less expression of interleukin-1β and interleukin-17 in the colon than in mice fed ad libitum. Administration of lactate in the colon at refeeding time by enema or by feeding lactylated high-amylose starch increased the number of regenerating crypts. Addition of lactate but not butyrate or acetate supported colony formation of colonocytes in vitro. In conclusion, intermittent fasting in the resolution phase of acute colitis resulted in better recovery of epithelial cells and reduced inflammation. PMID:28955126

Lipopolysaccharide from Crypt-Specific Core Microbiota Modulates the Colonic Epithelial Proliferation-to-Differentiation Balance.

PubMed

Naito, Tomoaki; Mulet, Céline; De Castro, Cristina; Molinaro, Antonio; Saffarian, Azadeh; Nigro, Giulia; Bérard, Marion; Clerc, Mélanie; Pedersen, Amy B; Sansonetti, Philippe J; Pédron, Thierry

2017-10-17

We identified a crypt-specific core microbiota (CSCM) dominated by strictly aerobic, nonfermentative bacteria in murine cecal and proximal colonic (PC) crypts and hypothesized that, among its possible functions, it may affect epithelial regeneration. In the present work, we isolated representative CSCM strains using selective media based upon our initial 16S rRNA-based molecular identification (i.e., Acinetobacter , Delftia , and Stenotrophomonas ). Their tropism for the crypt was confirmed, and their influence on epithelial regeneration was demonstrated in vivo by monocolonization of germfree mice. We also showed that lipopolysaccharide (LPS), through its endotoxin activity, was the dominant bacterial agonist controlling proliferation. The relevant molecular mechanisms were analyzed using colonic crypt-derived organoids exposed to bacterial sonicates or highly purified LPS as agonists. We identified a Toll-like receptor 4 (TLR4)-dependent program affecting crypts at different stages of epithelial differentiation. LPS played a dual role: it repressed cell proliferation through RIPK3-mediated necroptosis of stem cells and cells of the transit-amplifying compartment and concurrently enhanced cell differentiation, particularly the goblet cell lineage. IMPORTANCE The LPS from crypt-specific core microbiota controls intestinal epithelium proliferation through necroptosis of stem cells and enhances cell differentiation, mainly the goblet cell lineage. Copyright © 2017 Naito et al.

Extracellular pH regulation in microdomains of colonic crypts: effects of short-chain fatty acids.

PubMed Central

Chu, S; Montrose, M H

1995-01-01

It has been suggested that transepithelial gradients of short-chain fatty acids (SCFAs; the major anions in the colonic lumen) generate pH gradients across the colonic epithelium. Quantitative confocal microscopy was used to study extracellular pH in mouse distal colon with intact epithelial architecture, by superfusing tissue with carboxy SNARF-1 (a pH-sensitive fluorescent dye). Results demonstrate extracellular pH regulation in two separate microdomains surrounding colonic crypts: the crypt lumen and the subepithelial tissue adjacent to crypt colonocytes. Apical superfusion with (i) a poorly metabolized SCFA (isobutyrate), (ii) an avidly metabolized SCFA (n-butyrate), or (iii) a physiologic mixture of acetate/propionate/n-butyrate produced similar results: alkalinization of the crypt lumen and acidification of subepithelial tissue. Effects were (i) dependent on the presence and orientation of a transepithelial SCFA gradient, (ii) not observed with gluconate substitution, and (iii) required activation of sustained vectorial acid/base transport by SCFAs. Results suggest that the crypt lumen functions as a pH microdomain due to slow mixing with bulk superfusates and that crypts contribute significant buffering capacity to the lumen. In conclusion, physiologic SCFA gradients cause polarized extracellular pH regulation because epithelial architecture and vectorial transport synergize to establish regulated microenvironments. Images Fig. 1 Fig. 3 PMID:7724557

Central circuitries for body temperature regulation and fever.

PubMed

Nakamura, Kazuhiro

2011-11-01

Body temperature regulation is a fundamental homeostatic function that is governed by the central nervous system in homeothermic animals, including humans. The central thermoregulatory system also functions for host defense from invading pathogens by elevating body core temperature, a response known as fever. Thermoregulation and fever involve a variety of involuntary effector responses, and this review summarizes the current understandings of the central circuitry mechanisms that underlie nonshivering thermogenesis in brown adipose tissue, shivering thermogenesis in skeletal muscles, thermoregulatory cardiac regulation, heat-loss regulation through cutaneous vasomotion, and ACTH release. To defend thermal homeostasis from environmental thermal challenges, feedforward thermosensory information on environmental temperature sensed by skin thermoreceptors ascends through the spinal cord and lateral parabrachial nucleus to the preoptic area (POA). The POA also receives feedback signals from local thermosensitive neurons, as well as pyrogenic signals of prostaglandin E(2) produced in response to infection. These afferent signals are integrated and affect the activity of GABAergic inhibitory projection neurons descending from the POA to the dorsomedial hypothalamus (DMH) or to the rostral medullary raphe region (rMR). Attenuation of the descending inhibition by cooling or pyrogenic signals leads to disinhibition of thermogenic neurons in the DMH and sympathetic and somatic premotor neurons in the rMR, which then drive spinal motor output mechanisms to elicit thermogenesis, tachycardia, and cutaneous vasoconstriction. Warming signals enhance the descending inhibition from the POA to inhibit the motor outputs, resulting in cutaneous vasodilation and inhibited thermogenesis. This central thermoregulatory mechanism also functions for metabolic regulation and stress-induced hyperthermia.

Linear phase conjugation for atmospheric aberration compensation

NASA Astrophysics Data System (ADS)

Grasso, Robert J.; Stappaerts, Eddy A.

1998-01-01

Atmospheric induced aberrations can seriously degrade laser performance, greatly affecting the beam that finally reaches the target. Lasers propagated over any distance in the atmosphere suffer from a significant decrease in fluence at the target due to these aberrations. This is especially so for propagation over long distances. It is due primarily to fluctuations in the atmosphere over the propagation path, and from platform motion relative to the intended aimpoint. Also, delivery of high fluence to the target typically requires low beam divergence, thus, atmospheric turbulence, platform motion, or both results in a lack of fine aimpoint control to keep the beam directed at the target. To improve both the beam quality and amount of laser energy delivered to the target, Northrop Grumman has developed the Active Tracking System (ATS); a novel linear phase conjugation aberration compensation technique. Utilizing a silicon spatial light modulator (SLM) as a dynamic wavefront reversing element, ATS undoes aberrations induced by the atmosphere, platform motion or both. ATS continually tracks the target as well as compensates for atmospheric and platform motion induced aberrations. This results in a high fidelity, near-diffraction limited beam delivered to the target.

Influence of coma aberration on aperture averaged scintillations in oceanic turbulence

NASA Astrophysics Data System (ADS)

Luo, Yujuan; Ji, Xiaoling; Yu, Hong

2018-01-01

The influence of coma aberration on aperture averaged scintillations in oceanic turbulence is studied in detail by using the numerical simulation method. In general, in weak oceanic turbulence, the aperture averaged scintillation can be effectively suppressed by means of the coma aberration, and the aperture averaged scintillation decreases as the coma aberration coefficient increases. However, in moderate and strong oceanic turbulence the influence of coma aberration on aperture averaged scintillations can be ignored. In addition, the aperture averaged scintillation dominated by salinity-induced turbulence is larger than that dominated by temperature-induced turbulence. In particular, it is shown that for coma-aberrated Gaussian beams, the behavior of aperture averaged scintillation index is quite different from the behavior of point scintillation index, and the aperture averaged scintillation index is more suitable for characterizing scintillations in practice.

Sepsis reveals compartment-specific responses in intestinal proliferation and apoptosis in transgenic mice whose enterocytes re-enter the cell cycle.

PubMed

Lyons, John D; Klingensmith, Nathan J; Otani, Shunsuke; Mittal, Rohit; Liang, Zhe; Ford, Mandy L; Coopersmith, Craig M

2017-12-01

Cell production and death are tightly regulated in the rapidly renewing gut epithelium, with proliferation confined to crypts and apoptosis occurring in villi and crypts. This study sought to determine how stress alters these compartmentalized processes. Wild-type mice made septic via cecal ligation and puncture had decreased crypt proliferation and increased crypt and villus apoptosis. Fabpi -TAg mice expressing large T-antigen solely in villi had ectopic enterocyte proliferation with increased villus apoptosis in unmanipulated animals. Septic fabpi -TAg mice had an unexpected increase in villus proliferation compared with unmanipulated littermates, whereas crypt proliferation was decreased. Cell cycle regulators cyclin D1 and cyclin D2 were decreased in jejunal tissue in septic transgenic mice. In contrast, villus and crypt apoptosis were increased in septic fabpi -TAg mice. To examine the relationship between apoptosis and proliferation in a compartment-specific manner, fabpi -TAg mice were crossed with fabpl -Bcl-2 mice, resulting in expression of both genes in the villus but Bcl-2 alone in the crypt. Septic bi-transgenic animals had decreased crypt apoptosis but had a paradoxical increase in villus apoptosis compared with septic fabpi -TAg mice, associated with decreased proliferation in both compartments. Thus, sepsis unmasks compartment-specific proliferative and apoptotic regulation that is not present under homeostatic conditions.-Lyons, J. D., Klingensmith, N. J., Otani, S., Mittal, R., Liang, Z., Ford, M. L., Coopersmith, C. M. Sepsis reveals compartment-specific responses in intestinal proliferation and apoptosis in transgenic mice whose enterocytes re-enter the cell cycle. © FASEB.

DNA mismatch repair protein deficient non-neoplastic colonic crypts: a novel indicator of Lynch syndrome.

PubMed

Pai, Rish K; Dudley, Beth; Karloski, Eve; Brand, Randall E; O'Callaghan, Neil; Rosty, Christophe; Buchanan, Daniel D; Jenkins, Mark A; Thibodeau, Stephen N; French, Amy J; Lindor, Noralane M; Pai, Reetesh K

2018-06-08

Lynch syndrome is the most common form of hereditary colorectal carcinoma. However, establishing the diagnosis of Lynch syndrome is challenging, and ancillary studies that distinguish between sporadic DNA mismatch repair (MMR) protein deficiency and Lynch syndrome are needed, particularly when germline mutation studies are inconclusive. The aim of this study was to determine if MMR protein-deficient non-neoplastic intestinal crypts can help distinguish between patients with and without Lynch syndrome. We evaluated the expression of MMR proteins in non-neoplastic intestinal mucosa obtained from colorectal surgical resection specimens from patients with Lynch syndrome-associated colorectal carcinoma (n = 52) and patients with colorectal carcinoma without evidence of Lynch syndrome (n = 70), including sporadic MMR protein-deficient colorectal carcinoma (n = 30), MMR protein proficient colorectal carcinoma (n = 30), and "Lynch-like" syndrome (n = 10). MMR protein-deficient non-neoplastic colonic crypts were identified in 19 of 122 (16%) patients. MMR protein-deficient colonic crypts were identified in 18 of 52 (35%) patients with Lynch syndrome compared to only 1 of 70 (1%) patients without Lynch syndrome (p < 0.001). This one patient had "Lynch-like" syndrome and harbored two MSH2-deficient non-neoplastic colonic crypts. MMR protein-deficient non-neoplastic colonic crypts were not identified in patients with sporadic MMR protein-deficient or MMR protein proficient colorectal carcinoma. Our findings suggest that MMR protein-deficient colonic crypts are a novel indicator of Lynch syndrome, and evaluation for MMR protein-deficient crypts may be a helpful addition to Lynch syndrome diagnostics.

Lipopolysaccharide from Crypt-Specific Core Microbiota Modulates the Colonic Epithelial Proliferation-to-Differentiation Balance

PubMed Central

Naito, Tomoaki; Mulet, Céline; De Castro, Cristina; Molinaro, Antonio; Saffarian, Azadeh; Nigro, Giulia; Bérard, Marion; Clerc, Mélanie; Pedersen, Amy B.; Pédron, Thierry

2017-01-01

ABSTRACT We identified a crypt-specific core microbiota (CSCM) dominated by strictly aerobic, nonfermentative bacteria in murine cecal and proximal colonic (PC) crypts and hypothesized that, among its possible functions, it may affect epithelial regeneration. In the present work, we isolated representative CSCM strains using selective media based upon our initial 16S rRNA-based molecular identification (i.e., Acinetobacter, Delftia, and Stenotrophomonas). Their tropism for the crypt was confirmed, and their influence on epithelial regeneration was demonstrated in vivo by monocolonization of germfree mice. We also showed that lipopolysaccharide (LPS), through its endotoxin activity, was the dominant bacterial agonist controlling proliferation. The relevant molecular mechanisms were analyzed using colonic crypt-derived organoids exposed to bacterial sonicates or highly purified LPS as agonists. We identified a Toll-like receptor 4 (TLR4)-dependent program affecting crypts at different stages of epithelial differentiation. LPS played a dual role: it repressed cell proliferation through RIPK3-mediated necroptosis of stem cells and cells of the transit-amplifying compartment and concurrently enhanced cell differentiation, particularly the goblet cell lineage. PMID:29042502

Chromosomal aberrations and delays in cell progression induced by x-rays in Tradescantia clone 02 meristems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geard, C.R.

1983-01-01

In root meristems of Tradescantia clone 02 (developed by Sparrow and his colleagues for mutation studies), X-rays interfere with the progression of cells through the cell cycle and induce chromosomal aberrations in a dose-dependent manner consistent with linear-quadratic kinetics. Sequential mitotic cell accumulations after irradiation indicate that sensitivity to aberration induction is probably greatest in cells from late S to early G2, with chromatid interchanges the most frequent aberration type and all aberrations consistent with initiation from the interaction between two lesions. The ratio of the coefficients in the linear (..cap alpha..) and the quadratic (..beta..) terms (..cap alpha../..beta..) ismore » equal to the dose average of specific energy produced by individual particles in the site where interaction takes place. The ratio ..cap alpha../..beta.. for chromosomal aberrations is similar to that previously found for X-ray-induced mutation in Tradescantia stamen hairs, supporting the proposal that radiation-induced mutational events are due to chromosomal aberrations with interaction distances of about 1..mu..m. Abrahamson and co-workers have noted that both ..cap alpha../..beta.. ratios appear to be related to nuclear target size and are similar for chromosomal and mutational endpoints in the same organism. These findings support this concept; however, it is apparent that any situation which diminishes yield at high doses (e.g., mitotic delay) will probably affect the ..beta.. component. 23 references, 5 figures, 2 tables.« less

Endocrine cells in the denervated intestine

PubMed Central

Santos, Gilda C; Zucoloto, Sérgio; Garcia, Sérgio B

2000-01-01

This study deals with the effects of myenteric denervation of the proximal jejunum on endocrine cell population of the crypt-villus unit, 5 months after treatment with benzalkonium chloride (BAC). Male Wistar albino rats weighing on average 100 g were allocated to two groups: the BAC group − the proximal jejunal serosa was treated with 2 mm BAC for 30 min, and the control group − treated with saline solution (0,9% NaCl). There was a significant reduction in neurone number in the jejunal myenteric plexus of the BAC group and the endocrine cell population (serotoninergic and argyrophilic cells) was significantly increased in this intestine segment. In conclusion, the present findings provide further evidence that the myenteric denervation induced by BAC may lead to the development of a local imbalance of the neurotransmitters, with a consequent induction of enteroendocrine cell (argyrophilic and serotoninergic cells) hyperplasia in the crypt and villus. PMID:10971748

Yerba mate tea and mate saponins prevented azoxymethane-induced inflammation of rat colon through suppression of NF-κB p65ser(311) signaling via IκB-α and GSK-3β reduced phosphorylation.

PubMed

Puangpraphant, Sirima; Dia, Vermont P; de Mejia, Elvira Gonzalez; Garcia, Guadalupe; Berhow, Mark A; Wallig, Matthew A

2013-01-01

Yerba mate tea (YMT) has a chemopreventive role in a variety of inflammatory diseases. The objective was to determine the capability of YMT and mate saponins to prevent azoxymethane (AOM)-induced colonic inflammation in rats. YMT (2% dry leaves, w/v, as a source of drinking fluid) (n = 15) and mate saponins (0.01% in the diet, at a concentration present in one cup of YMT) (n = 15) were given ad libitum to rats 2 weeks prior to AOM-injection until the end of the study; while control rats (n = 15) received a basal diet and drinking water. After 8-weeks of study, total colonic mucosa was scraped (n = 3 rats/group) and the remaining colons (n =12 rats/group) were cut into three equal sections and aberrant crypt foci (ACF) were analyzed. YMT reduced ACF formation from 113 (control group) to 89 (P < 0.05). YMT and mate saponins reduced the expression of proinflammatory molecules COX-2 and iNOS with concomitant reduction in p-p65 (P < 0.05). Immunohistochemical analysis of the formalin-fixed middle colons showed that YMT and mate saponins reduced the expression of p-p65(ser311) by 45.7% and 43.1%, respectively, in comparison to the control (P < 0.05). In addition, the expression of molecules upstream of NF-κB such as p-IκB-α and p-GSK-3β(Y216) was downregulated by YMT 24.7% and 24.4%, respectively (P < 0.05). Results suggest the mechanism involved in the chemopreventive effect of YMT and mate saponin consumption in AOM induced-colonic inflammation in rats is through inhibition of NF-κB. Copyright © 2012 International Union of Biochemistry and Molecular Biology, Inc.

Chromatin Folding, Fragile Sites, and Chromosome Aberrations Induced by Low- and High- LET Radiation

NASA Technical Reports Server (NTRS)

Zhang, Ye; Cox, Bradley; Asaithamby, Aroumougame; Chen, David J.; Wu, Honglu

2013-01-01

We previously demonstrated non-random distributions of breaks involved in chromosome aberrations induced by low- and high-LET radiation. To investigate the factors contributing to the break point distribution in radiation-induced chromosome aberrations, human epithelial cells were fixed in G1 phase. Interphase chromosomes were hybridized with a multicolor banding in situ hybridization (mBAND) probe for chromosome 3 which distinguishes six regions of the chromosome in separate colors. After the images were captured with a laser scanning confocal microscope, the 3-dimensional structure of interphase chromosome 3 was reconstructed at multimega base pair scale. Specific locations of the chromosome, in interphase, were also analyzed with bacterial artificial chromosome (BAC) probes. Both mBAND and BAC studies revealed non-random folding of chromatin in interphase, and suggested association of interphase chromatin folding to the radiation-induced chromosome aberration hotspots. We further investigated the distribution of genes, as well as the distribution of breaks found in tumor cells. Comparisons of these distributions to the radiation hotspots showed that some of the radiation hotspots coincide with the frequent breaks found in solid tumors and with the fragile sites for other environmental toxins. Our results suggest that multiple factors, including the chromatin structure and the gene distribution, can contribute to radiation-induced chromosome aberrations.

Dietary arginine supplementation alleviates intestinal mucosal disruption induced by Escherichia coli lipopolysaccharide in weaned pigs.

PubMed

Liu, Yulan; Huang, Jingjing; Hou, Yongqing; Zhu, Huiling; Zhao, Shengjun; Ding, Binying; Yin, Yulong; Yi, Ganfeng; Shi, Junxia; Fan, Wei

2008-09-01

This study evaluated whether arginine (Arg) supplementation could attenuate gut injury induced by Escherichia coli lipopolysaccharide (LPS) challenge through an anti-inflammatory role in weaned pigs. Pigs were allotted to four treatments including: (1) non-challenged control; (2) LPS-challenged control; (3) LPS+0.5 % Arg; (4) LPS+1.0 % Arg. On day 16, pigs were injected with LPS or sterile saline. At 6 h post-injection, pigs were killed for evaluation of small intestinal morphology and intestinal gene expression. Within 48 h of challenge, 0.5 % Arg alleviated the weight loss induced by LPS challenge (P = 0.025). In all three intestinal segments, 0.5 or 1.0 % Arg mitigated intestinal morphology impairment (e.g. lower villus height and higher crypt depth) induced by LPS challenge (P < 0.05), and alleviated the decrease of crypt cell proliferation and the increase of villus cell apoptosis after LPS challenge (P < 0.01). The 0.5 % Arg prevented the elevation of jejunal IL-6 mRNA abundance (P = 0.082), and jejunal (P = 0.030) and ileal (P = 0.039) TNF-alpha mRNA abundance induced by LPS challenge. The 1.0 % Arg alleviated the elevation of jejunal IL-6 mRNA abundance (P = 0.053) and jejunal TNF-alpha mRNA abundance (P = 0.003) induced by LPS challenge. The 0.5 % Arg increased PPARgamma mRNA abundance in all three intestinal segments (P < 0.10), and 1.0 % Arg increased duodenal PPARgamma mRNA abundance (P = 0.094). These results indicate that Arg supplementation has beneficial effects in alleviating gut mucosal injury induced by LPS challenge. Additionally, it is possible that the protective effects of Arg on the intestine are associated with decreasing the expression of intestinal pro-inflammatory cytokines through activating PPARgamma expression.

Culturing and Characterization of Gut Symbiont Burkholderia spp. from the Southern Chinch Bug, Blissus insularis (Hemiptera: Blissidae)

PubMed Central

Buss, Eileen A.; Boucias, Drion G.

2016-01-01

ABSTRACT The phloem-feeding Southern chinch bug, Blissus insularis, harbors a high density of the exocellular bacterial symbiont Burkholderia in the lumen of specialized midgut crypts. Here we developed an organ culture method that initially involved incubating the B. insularis crypts in osmotically balanced insect cell culture medium. This approach enabled the crypt-inhabiting Burkholderia spp. to make a transition to an in vitro environment and to be subsequently cultured in standard bacteriological media. Examinations using ribotyping and BOX-PCR fingerprinting techniques demonstrated that most in vitro-produced bacterial cultures were identical to their crypt-inhabiting Burkholderia counterparts. Genomic and physiological analyses of gut-symbiotic Burkholderia spp. that were isolated individually from two separate B. insularis laboratory colonies revealed that the majority of individual insects harbored a single Burkholderia ribotype in their midgut crypts, resulting in a diverse Burkholderia community within each colony. The diversity was also exhibited by the phenotypic and genotypic characteristics of these Burkholderia cultures. Access to cultures of crypt-inhabiting bacteria provides an opportunity to investigate the interaction between symbiotic Burkholderia spp. and the B. insularis host. Furthermore, the culturing method provides an alternative strategy for establishing in vitro cultures of other fastidious insect-associated bacterial symbionts. IMPORTANCE An organ culture method was developed to establish in vitro cultures of a fastidious Burkholderia symbiont associated with the midgut crypts of the Southern chinch bug, Blissus insularis. The identities of the resulting cultures were confirmed using the genomic and physiological features of Burkholderia cultures isolated from B. insularis crypts, showing that host insects maintained the diversity of Burkholderia spp. over multiple generations. The availability of characterized gut-symbiotic Burkholderia cultures provides a resource for genetic manipulation of these bacteria and for examination of the mechanisms underlying insect-bacterium symbiosis. PMID:27016568

Effects of calcium and vitamin D supplementation on crypt morphology in normal colon mucosa: A randomized clinical trial.

PubMed

Shen, Huafeng; Ahearn, Thomas U; Bostick, Roberd M

2015-03-01

Calcium and vitamin D modify the molecular phenotypic profiles of colon crypts in the normal colorectal mucosa of colorectal adenoma patients, but their effects on crypt morphology (length, perimeter, and area) are unknown. We analyzed data from a previously conducted pilot, randomized, double-blind, placebo-controlled 2 × 2 factorial chemoprevention clinical trial of supplemental calcium 2000 mg/d and vitamin D3 800 IU/d, alone and in combination, versus placebo over 6 mo. Colorectal crypt length, perimeter, and area in the normal-appearing rectal mucosa were quantified by image analysis. The mean crypt length increased by 1% (P=0.92) in the calcium group, and decreased by 2% (P=0.69) and 4% (P=0.40) in the vitamin D and calcium plus vitamin D groups, respectively, relative to the placebo group. The mean crypt perimeter decreased by 2% (P=0.70) and 4% (P=0.40) in the vitamin D and calcium plus vitamin D groups, respectively, relative to the placebo group, but did not change appreciably in the calcium group. The mean crypt area decreased by 2% (P=0.74), 5% (P=0.41) and 7% (P=0.30) in the calcium, vitamin D and calcium plus vitamin D groups, respectively, relative to the placebo group. Calcium and/or vitamin D3 supplementation do not appear to appreciably change crypt morphology in the normal colorectal mucosa of sporadic adenoma patients. These results, taken together with previous findings, support the use of molecular phenotypic over morphologic pre-neoplastic biomarkers of risk for colorectal neoplasms. © 2013 Wiley Periodicals, Inc.

Adaptive optics full-field OCT: a resolution almost insensitive to aberrations (Conference Presentation)

NASA Astrophysics Data System (ADS)

Xiao, Peng; Fink, Mathias; Boccara, A. Claude

2016-03-01

A Full-Field OCT (FFOCT) setup coupled to a compact transmissive liquid crystal spatial light modulator (LCSLM) is used to induce or correct aberrations and simulate eye examinations. To reduce the system complexity, strict pupil conjugation was abandoned. During our work on quantifying the effect of geometrical aberrations on FFOCT images, we found that the image resolution is almost insensitive to aberrations. Indeed if the object channel PSF is distorted, its interference with the reference channel conserves the main feature of an unperturbed PSF with only a reduction of the signal level. This unique behavior is specific to the use of a spatially incoherent illumination. Based on this, the FFOCT image intensity was used as the metric for our wavefront sensorless correction. Aberration correction was first conducted on an USAF resolution target with the LSCLM as both aberration generator and corrector. A random aberration mask was induced, and the low-order Zernike Modes were corrected sequentially according to the intensity metric function optimization. A Ficus leaf and a fixed mouse brain tissue slice were also imaged to demonstrate the correction of sample self-induced wavefront distortions. After optimization, more structured information appears for the leaf imaging. And the high-signal fiber-like myelin fiber structures were resolved much more clearly after the whole correction process for mouse brain imaging. Our experiment shows the potential of this compact AO-FFOCT system for aberration correction imaging. This preliminary approach that simulates eyes aberrations correction also opens the path to a simple implementation of FFOCT adaptive optics for retinal examinations.

Histopathological studies on the cystic formation of the human urothelium.

PubMed

Noda, S; Eto, K

1990-01-01

Histopathological examination of pyeloureteritis cystica and cystitis cystica revealed the mechanisms for the cystic formation of the urothelium. Chronic stimulation with inflammation or physical stimulation with crystals or calculi causes the urothelium to form an inflammatory crypt. The crypt is isolated as a result of an adhesive occlusion of the urothelium at the orifice of the crypt. This crypt is an immature cyst that cannot be clinically detected. A von Brunn's cell nest represents a cut surface of the immature cyst. The inflammatory cyst isolated from the urinary tract, i.e., the immature cyst, gradually grows into a complete cyst, i.e., a clinically visible mature cyst, because of a hydrodynamic flow between the surrounding tissue and neogenetic capillaries, and inflammation. These findings indicate that von Brunn's cell nest, and glandular and cystic formation, occur during development from an inflammatory crypt to an immature cyst and then, a mature cyst.

Wavefront correction for static and dynamic aberrations to within 1 second of the system shot in the NIF Beamlet demonstration facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hartley, R.; Kartz, M.; Behrendt, W.

1996-10-01

The laser wavefront of the NIF Beamlet demonstration system is corrected for static aberrations with a wavefront control system. The system operates closed loop with a probe beam prior to a shot and has a loop bandwidth of about 3 Hz. However, until recently the wavefront control system was disabled several minutes prior to the shot to allow time to manually reconfigure its attenuators and probe beam insertion mechanism to shot mode. Thermally-induced dynamic variations in gas density in the Beamlet main beam line produce significant wavefront error. After about 5-8 seconds, the wavefront error has increased to a new,more » higher level due to turbulence- induced aberrations no longer being corrected- This implies that there is a turbulence-induced aberration noise bandwidth of less than one Hertz, and that the wavefront controller could correct for the majority of turbulence-induced aberration (about one- third wave) by automating its reconfiguration to occur within one second of the shot, This modification was recently implemented on Beamlet; we call this modification the t{sub 0}-1 system.« less

BMP4 and BMP7 Suppress StAR and Progesterone Production via ALK3 and SMAD1/5/8-SMAD4 in Human Granulosa-Lutein Cells.

PubMed

Zhang, Han; Klausen, Christian; Zhu, Hua; Chang, Hsun-Ming; Leung, Peter C K

2015-11-01

Adequate production of progesterone by the corpus luteum is critical to the successful establishment of pregnancy. In animal models, bone morphogenetic protein (BMP) 4 and BMP7 have been shown to suppress either basal or gonadotropin-induced progesterone production, depending on the species examined. However, the effects of BMP4 and BMP7 on progesterone production in human granulosa cells are unknown. In the present study, we used immortalized (SVOG) and primary human granulosa-lutein cells to investigate the effects of BMP4 and BMP7 on steroidogenic acute regulatory protein (StAR) expression and progesterone production and to examine the underlying molecular mechanism. Treatment of primary and immortalized human granulosa cells with recombinant BMP4 or BMP7 decreased StAR expression and progesterone accumulation. In SVOG cells, the suppressive effects of BMP4 and BMP7 on StAR expression were blocked by pretreatment with inhibitors of activin receptor-like kinase (ALK)2/3/6 (dorsomorphin) or ALK2/3 (DMH1) but not ALK4/5/7 (SB-431542). Moreover, small interfering RNA-mediated depletion of ALK3, but not ALK2 or ALK6, reversed the effects of BMP4 and BMP7 on StAR expression. Likewise, BMP4- and BMP7-induced phosphorylation of SMAD 1/5/8 was reversed by treatment with DMH1 or small interfering RNA targeting ALK3. Knockdown of SMAD4, the essential common SMAD for BMP/TGF-β signaling, abolished the effects of BMP4 and BMP7 on StAR expression. Our results suggest that BMP4 and BMP7 down-regulate StAR and progesterone production via ALK3 and SMAD1/5/8-SMAD4 signaling in human granulosa-lutein cells.

Prostaglandin D2 regulates human colonic ion transport via the DP1 receptor.

PubMed

Medani, M; Collins, D; Mohan, H M; Walsh, E; Winter, D C; Baird, A W

2015-02-01

Prostaglandin D2 is released by mast cells and is important in allergies. Its role in gastrointestinal function is not clearly defined. This study aimed to determine the effect of exogenous PGD2 on ion transport in ex vivo normal human colonic mucosa. Mucosal sheets were mounted in Ussing chambers and voltage clamped to zero electric potential. Ion transport was quantified as changes in short-circuit current. In separate experiments epithelial monolayers or colonic crypts, isolated by calcium chelation, were treated with PGD2 and cAMP levels determined by ELISA or calcium levels were determined by fluorimetry. PGD2 caused a sustained, concentration-dependent rise in short-circuit current by increasing chloride secretion (EC50=376nM). This effect of PGD2 is mediated by the DP1 receptor, as the selective DP1 receptor antagonist BW A686C inhibited PGD2-induced but not PGE2-induced rise in short-circuit current. PGD2 also increased intracellular cAMP in isolated colonic crypts with no measurable influence on cytosolic calcium. PGD2 induces chloride secretion in isolated human colonic mucosa in a concentration-dependent manner with concomitant elevation of cytoplasmic cAMP in epithelial cells. The involvement of DP2 receptor subtypes has not previously been considered in regulation of ion transport in human intestine. Since inflammatory stimuli may induce production of eicosanoids, selective regulation of these pathways may be pivotal in determining therapeutic strategies and in understanding disease. Copyright © 2014. Published by Elsevier Inc.

Mesalamine inhibits epithelial beta-catenin activation in chronic ulcerative colitis.

PubMed

Brown, Jeffrey B; Lee, Goo; Managlia, Elizabeth; Grimm, Gery R; Dirisina, Ramanarao; Goretsky, Tatiana; Cheresh, Paul; Blatner, Nichole R; Khazaie, Khashayarsha; Yang, Guang-Yu; Li, Linheng; Barrett, Terrence A

2010-02-01

Mesalamine is a mainstay therapeutic agent in chronic ulcerative colitis (CUC) in which condition it reverses crypt architectural changes and reduces colitis-associated cancer (CAC). The present study addressed the possibility that mesalamine reduces beta-catenin-associated progenitor cell activation, Akt-phosphorylated beta-catenin(Ser552) (P-beta-catenin), and colitis-induced dysplasia (CID). Effects of mesalamine on P-beta-catenin staining and function were assessed by immunohistochemistry and quantitative reverse-transcription polymerase chain reaction (qRT-PCR) in biopsy specimens of CUC in mild or "refractory" severe mucosal inflammation. Effects of mesalamine on epithelial proliferation and activation of Akt and beta-catenin were assessed in interleukin (IL)-10(-/-) colitis and CID by immunohistochemistry and Western blotting. Dysplasia was assessed by counting the number and lengths of lesions per colon. Data from IL-10(-/-) and human colitis samples show that mesalamine reduced Akt activation and P-beta-catenin levels in the middle and upper crypt. Reductions in P-beta-catenin in CUC biopsy specimens with severe inflammation suggested that mesalamine reduced P-beta-catenin levels in tissue refractory to mesalamine's anti-inflammatory effects. In IL-10(-/-) mice, mesalamine reduced CID concordant with inhibition of crypt Akt and beta-catenin signaling. The results are consistent with the model that mesalamine contributes to chemoprevention in CAC by reducing beta-catenin signaling within intestinal progenitors.

Chicken astrovirus as an aetiological agent of runting-stunting syndrome in broiler chickens.

PubMed

Kang, Kyung-Il; Linnemann, Erich; Icard, Alan H; Durairaj, Vijay; Mundt, Egbert; Sellers, Holly S

2018-04-01

Despite descriptions of runting-stunting syndrome (RSS) in broiler chickens dating back over 40 years, the aetiology has not yet been described. A novel chicken astrovirus (CkAstV) was isolated in an LMH liver cell line from the intestines of chickens affected with RSS. Clinical RSS is characterized by retarded growth and cystic crypt lesions in the small intestine. In 1-day-old broiler chickens infected with the CkAstV isolate, virus was only detected in the intestinal epithelial cells during the first few days after infection. Notably, the preferred host cells are the crypt epithelial cells following initial replication in the villous epithelial cells, thus implying viral preference for immature intestinal cells. Nevertheless, the CkAstV isolate did not induce remarkable pathological changes, despite the presence of the virus in situ. Serial chicken-to-chicken passages of the virus induced increased virulence, as displayed by decreased weight gain and the presence of cystic lesions in the small intestine reproducing clinical RSS in chickens. The analysis of the full-length genome sequences from the isolated CkAstV and the CkAstV from the bird-to-bird passages showed >99 % similarity. The data obtained in this study suggest that the CkAstV isolate is capable of inducing RSS following serial bird-to-bird passages in broilers and is as an aetiological agent of the disease.

Central Control of Circadian Phase in Arousal-Promoting Neurons

PubMed Central

Mahoney, Carrie E.; McKinley Brewer, Judy; Bittman, Eric L.

2013-01-01

Cells of the dorsomedial/lateral hypothalamus (DMH/LH) that produce hypocretin (HCRT) promote arousal in part by activation of cells of the locus coeruleus (LC) which express tyrosine hydroxylase (TH). The suprachiasmatic nucleus (SCN) drives endogenous daily rhythms, including those of sleep and wakefulness. These circadian oscillations are generated by a transcriptional-translational feedback loop in which the Period (Per) genes constitute critical components. This cell-autonomous molecular clock operates not only within the SCN but also in neurons of other brain regions. However, the phenotype of such neurons and the nature of the phase controlling signal from the pacemaker are largely unknown. We used dual fluorescent in situ hybridization to assess clock function in vasopressin, HCRT and TH cells of the SCN, DMH/LH and LC, respectively, of male Syrian hamsters. In the first experiment, we found that Per1 expression in HCRT and TH oscillated in animals held in constant darkness with a peak phase that lagged that in AVP cells of the SCN by several hours. In the second experiment, hamsters induced to split their locomotor rhythms by exposure to constant light had asymmetric Per1 expression within cells of the middle SCN at 6 h before activity onset (AO) and in HCRT cells 9 h before and at AO. We did not observe evidence of lateralization of Per1 expression in the LC. We conclude that the SCN communicates circadian phase to HCRT cells via lateralized neural projections, and suggests that Per1 expression in the LC may be regulated by signals of a global or bilateral nature. PMID:23826226

Effect of an inhibitor of noradrenaline uptake, desipramine, on cell proliferation in the intestinal crypt epithelium.

PubMed

Tutton, P J; Barkla, D H

1989-01-01

The intestinal mucosa receives an adrenergic innervation for which there is no commonly accepted function. However, in recent years, cell kinetic studies have raised the possibility that this innervation may be an important regulator of crypt cell proliferation. The effects of noradrenaline released from adrenergic nerves is terminated principally by re-uptake of the amine into the nerve and this process can be inhibited by the antidepressant drug, desipramine. In this report desipramine is shown to accelerate crypt cell proliferation in intact, but not in chemically sympathectomized rats, thus adding support to the notion that regulation of crypt cell division is an important function of the sympathetic nervous system.

Stochastic modelling for biodosimetry: Predicting the chromosomal response to radiation at different time points after exposure

NASA Astrophysics Data System (ADS)

Deperas-Standylo, Joanna; Gudowska-Nowak, Ewa; Ritter, Sylvia

2014-07-01

Cytogenetic data accumulated from the experiments with peripheral blood lymphocytes exposed to densely ionizing radiation clearly demonstrate that for particles with linear energy transfer (LET) >100 keV/ μm the derived relative biological effectiveness (RBE) will strongly depend on the time point chosen for the analysis. A reasonable prediction of radiation-induced chromosome damage and its distribution among cells can be achieved by exploiting Monte Carlo methodology along with the information about the radius of the penetrating ion-track and the LET of the ion beam. In order to examine the relationship between the track structure and the distribution of aberrations induced in human lymphocytes and to clarify the correlation between delays in the cell cycle progression and the aberration burden visible at the first post-irradiation mitosis, we have analyzed chromosome aberrations in lymphocytes exposed to Fe-ions with LET values of 335 keV/ μm and formulated a Monte Carlo model which reflects time-delay in mitosis of aberrant cells. Within the model the frequency distributions of aberrations among cells follow the pattern of local energy distribution and are well approximated by a time-dependent compound Poisson statistics. The cell-division cycle of undamaged and aberrant cells and chromosome aberrations are modelled as a renewal process represented by a random sum of (independent and identically distributed) random elements S N = ∑ N i=0 X i . Here N stands for the number of particle traversals of cell nucleus, each leading to a statistically independent formation of X i aberrations. The parameter N is itself a random variable and reflects the cell cycle delay of heavily damaged cells. The probability distribution of S N follows a general law for which the moment generating function satisfies the relation Φ S N = Φ N ( Φ X i ). Formulation of the Monte Carlo model which allows to predict expected fluxes of aberrant and non-aberrant cells has been based on several input information: (i) experimentally measured mitotic index in the population of irradiated cells; (ii) scored fraction of cells in first cell cycle; (iii) estimated average number of particle traversals per cell nucleus. By reconstructing the local dose distribution in the biological target, the relevant amount of lesions induced by ions is estimated from the biological effect induced by photons at the same dose level. Moreover, the total amount of aberrations induced within the entire population has been determined. For each subgroup of intact (non-hit) and aberrant cells the cell-division cycle has been analyzed reproducing correctly an expected correlation between mitotic delay and the number of aberrations carried by a cell. This observation is of particular importance for the proper estimation of the biological efficiency of ions and for the estimation of health risks associated with radiation exposure.

Transepithelial SCFA fluxes link intracellular and extracellular pH regulation of mouse colonocytes.

PubMed

Chu, S; Montrose, M H

1997-10-01

We have studied pH regulation in both intracellular and extracellular compartments of mouse colonic crypts, using distal colonic mucosa with intact epithelial architecture. In this work, we question how transepithelial SCFA gradients affect intracellular pH (pHi) and examine interactions between extracellular pH (pHo) and pHi regulation in crypts of distal colonic epithelium from mouse. We studied pH regulation in three adjacent compartments of distal colonic epithelium (crypt lumen, crypt epithelial cell cytosol, and lamina propria) with SNARF-1 (a pH sensitive fluorescent dye), digital imaging microscopy (for pHi), and confocal microscopy (for pHo). Combining results from the three compartments allows us to find how pHi and pHo are regulated and related under the influence of physiological transepithelial SCFA gradients, and develop a better understanding of pH regulation mechanisms in colonic crypts. Results suggest a complex interdependency between SCFA fluxes and pHo values, which can directly affect how strongly SCFAs acidify colonocytes.

Chromosomal aberrations and delays in cell progression induced by x-rays in Tradescantia clone 02 meristems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geard, C.R.

1983-01-01

In root meristems of Tradescantia clone 02 (developed by Sparrow and his colleagues for mutation studies), X-rays interfere with the progression of cells through the cell cycle and induce chromosomal aberrations in a dose-dependent manner consistent with linear-quadratic kinetics. Sequential mitotic cell accumulations after irradiation indicate that sensitivity to aberrration induction is probably greatest in cells from late S to early G2, with chromatid interchanges the most frequent aberration type and all aberrations consistent with intiation from the interaction between two lesions. The ratio of the coefficients in the linear (..cap alpha..) and the quadratic (..beta..) terms (..cap alpha../..beta..) ismore » equal to the dose average of specific energy produced by individual particles in the site where interaction takes place. The ratio ..cap alpha../..beta.. for chromosomal aberrations is similar to that previously found for X-ray-induced mutation in Tradescantia stamen hairs, supporting the proposal that radiation-induced mutational events are due to chromosomal aberrations with interaction distances of about 1 ..mu..m. Abrahmson and co-workers have noted that both ..cap alpha../..beta.. ratios appear to be related to nuclear target size and are similar for chromosomal and mutational endpoints in the same organism. These findings support this concept; however, it is apparent that any situation which diminishes yield at high doses (e.g., mitotic delay) will primarily affect the ..beta.. component, resulting in low assessments of interaction site diameters.« less

Primary aberrations in focused radially polarized vortex beams

NASA Astrophysics Data System (ADS)

Biss, David P.; Brown, T. G.

2004-02-01

We study the effect of primary aberrations on the 3-D polarization of the electric field in a focused lowest order radially polarized beam. A full vector diffraction treatment of the focused beams is used. Attention is given to the effects of primary spherical, astigmatic, and comatic aberrations on the local polarization, Strehl ratio, and aberration induced degradation of the longitudinal field at focus

Temporal Dependence of Chromosomal Aberration on Radiation Quality and Cellular Genetic Background

NASA Technical Reports Server (NTRS)

Lu, Tao; Zhang, Ye; Krieger, Stephanie; Yeshitla, Samrawit; Goss, Rosalin; Bowler, Deborah; Kadhim, Munira; Wilson, Bobby; Wu, Honglu

2017-01-01

Radiation induced cancer risks are driven by genetic instability. It is not well understood how different radiation sources induce genetic instability in cells with different genetic background. Here we report our studies on genetic instability, particularly chromosome instability using fluorescence in situ hybridization (FISH), in human primary lymphocytes, normal human fibroblasts, and transformed human mammary epithelial cells in a temporal manner after exposure to high energy protons and Fe ions. The chromosome spread was prepared 48 hours, 1 week, 2 week, and 1 month after radiation exposure. Chromosome aberrations were analyzed with whole chromosome specific probes (chr. 3 and chr. 6). After exposure to protons and Fe ions of similar cumulative energy (??), Fe ions induced more chromosomal aberrations at early time point (48 hours) in all three types of cells. Over time (after 1 month), more chromosome aberrations were observed in cells exposed to Fe ions than in the same type of cells exposed to protons. While the mammary epithelial cells have higher intrinsic genetic instability and higher rate of initial chromosome aberrations than the fibroblasts, the fibroblasts retained more chromosomal aberration after long term cell culture (1 month) in comparison to their initial frequency of chromosome aberration. In lymphocytes, the chromosome aberration frequency at 1 month after exposure to Fe ions was close to unexposed background, and the chromosome aberration frequency at 1 month after exposure to proton was much higher. In addition to human cells, mouse bone marrow cells isolated from strains CBA/CaH and C57BL/6 were irradiated with proton or Fe ions and were analyzed for chromosome aberration at different time points. Cells from CBA mice showed similar frequency of chromosome aberration at early and late time points, while cells from C57 mice showed very different chromosome aberration rate at early and late time points. Our results suggest that relative biological effectiveness (RBE) of radiation are different for different radiation sources, for different cell types, and for the same cell type with different genetic background at different times after radiation exposure. Caution must be taken in using RBE value to estimate biological effects from radiation exposure.

Salience attribution and its relationship to cannabis-induced psychotic symptoms.

PubMed

Bloomfield, M A P; Mouchlianitis, E; Morgan, C J A; Freeman, T P; Curran, H V; Roiser, J P; Howes, O D

2016-12-01

Cannabis is a widely used drug associated with increased risk for psychosis. The dopamine hypothesis of psychosis postulates that altered salience processing leads to psychosis. We therefore tested the hypothesis that cannabis users exhibit aberrant salience and explored the relationship between aberrant salience and dopamine synthesis capacity. We tested 17 cannabis users and 17 age- and sex-matched non-user controls using the Salience Attribution Test, a probabilistic reward-learning task. Within users, cannabis-induced psychotic symptoms were measured with the Psychotomimetic States Inventory. Dopamine synthesis capacity, indexed as the influx rate constant K i cer , was measured in 10 users and six controls with 3,4-dihydroxy-6-[18F]fluoro-l-phenylalanine positron emission tomography. There was no significant difference in aberrant salience between the groups [F 1,32 = 1.12, p = 0.30 (implicit); F 1,32 = 1.09, p = 0.30 (explicit)]. Within users there was a significant positive relationship between cannabis-induced psychotic symptom severity and explicit aberrant salience scores (r = 0.61, p = 0.04) and there was a significant association between cannabis dependency/abuse status and high implicit aberrant salience scores (F 1,15 = 5.8, p = 0.03). Within controls, implicit aberrant salience was inversely correlated with whole striatal dopamine synthesis capacity (r = -0.91, p = 0.01), whereas this relationship was non-significant within users (difference between correlations: Z = -2.05, p = 0.04). Aberrant salience is positively associated with cannabis-induced psychotic symptom severity, but is not seen in cannabis users overall. This is consistent with the hypothesis that the link between cannabis use and psychosis involves alterations in salience processing. Longitudinal studies are needed to determine whether these cognitive abnormalities are pre-existing or caused by long-term cannabis use.

Radioprotective effects of miso (fermented soy bean paste) against radiation in B6C3F1 mice: increased small intestinal crypt survival, crypt lengths and prolongation of average time to death.

PubMed

Ohara, M; Lu, H; Shiraki, K; Ishimura, Y; Uesaka, T; Katoh, O; Watanabe, H

2001-12-01

The radioprotective effect of miso, a fermentation product from soy bean, was investigated with reference to the survival time, crypt survival and jejunum crypt length in male B6C3F1 mice. Miso at three different fermentation stages (early-, medium- and long-term fermented miso) was mixed in MF diet into biscuits at 10% and was administered from 1 week before irradiation. Animal survival in the long-term fermented miso group was significantly prolonged as compared with the short-term fermented miso and MF cases after 8 Gy of 60Co-gamma-ray irradiation at a dose rate of 2Gy min(-1). Delay in mortality was evident in all three miso groups, with significantly increased survival. At doses of 10 and 12 Gy X-irradiation at a dose rate of 4 Gy min(-1), the treatment with long-term fermented miso significantly increased crypt survival. Also the protective influence against irradiation in terms of crypt lengths in the long-term fermented miso group was significantly greater than in the short-term or medium-term fermented miso and MF diet groups. Thus, prolonged fermentation appears to be very important for protection against radiation effects.

Culturing and Characterization of Gut Symbiont Burkholderia spp. from the Southern Chinch Bug, Blissus insularis (Hemiptera: Blissidae).

PubMed

Xu, Yao; Buss, Eileen A; Boucias, Drion G

2016-06-01

The phloem-feeding Southern chinch bug, Blissus insularis, harbors a high density of the exocellular bacterial symbiont Burkholderia in the lumen of specialized midgut crypts. Here we developed an organ culture method that initially involved incubating the B. insularis crypts in osmotically balanced insect cell culture medium. This approach enabled the crypt-inhabiting Burkholderia spp. to make a transition to an in vitro environment and to be subsequently cultured in standard bacteriological media. Examinations using ribotyping and BOX-PCR fingerprinting techniques demonstrated that most in vitro-produced bacterial cultures were identical to their crypt-inhabiting Burkholderia counterparts. Genomic and physiological analyses of gut-symbiotic Burkholderia spp. that were isolated individually from two separate B. insularis laboratory colonies revealed that the majority of individual insects harbored a single Burkholderia ribotype in their midgut crypts, resulting in a diverse Burkholderia community within each colony. The diversity was also exhibited by the phenotypic and genotypic characteristics of these Burkholderia cultures. Access to cultures of crypt-inhabiting bacteria provides an opportunity to investigate the interaction between symbiotic Burkholderia spp. and the B. insularis host. Furthermore, the culturing method provides an alternative strategy for establishing in vitro cultures of other fastidious insect-associated bacterial symbionts. An organ culture method was developed to establish in vitro cultures of a fastidious Burkholderia symbiont associated with the midgut crypts of the Southern chinch bug, Blissus insularis The identities of the resulting cultures were confirmed using the genomic and physiological features of Burkholderia cultures isolated from B. insularis crypts, showing that host insects maintained the diversity of Burkholderia spp. over multiple generations. The availability of characterized gut-symbiotic Burkholderia cultures provides a resource for genetic manipulation of these bacteria and for examination of the mechanisms underlying insect-bacterium symbiosis. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

mBAND Analysis of Early and Late Damages in the Chromosome of Human Lymphocytes after Exposures to Gamma Rays and Fe Ions

NASA Technical Reports Server (NTRS)

Sunagawa, Mayumi; Zhang, Ye; Yeshitla, Samrawit; Kadhim, Munira; Wilson, Bobby; Wu, Honglu

2013-01-01

Stable type chromosome aberrations that survive multiple generations of cell division include translocation and inversions. An efficient method to detect an inversion is multi-color banding fluorescent in situ hybridization (mBAND) which allows identification of both inter- and intrachromosome aberrations simultaneously. Post irradiation, chromosome aberrations may also arise after multiple cell divisions as a result of genomic instability. To investigate the stable or late-arising chromosome aberrations induced after radiation exposure, we exposed human lymphocytes to gamma rays and Fe ions ex vivo, and cultured the cells for multiple generations. Chromosome aberrations were analyzed in cells collected at first mitosis and at several time intervals during the culture period post irradiation. With gamma irradiation, about half of the damages observed at first mitosis remained after 7 day- and 14 day- culture, suggesting the transmissibility of damages to the surviving progeny. At the doses that produced similar frequencies of gamma-induced chromosome aberrations as observed at first mitosis, a significantly lower yield of aberrations remained at the same population doublings after Fe ion exposure. At these equitoxic doses, more complex type aberrations were observed for Fe ions, indicating that Fe ion-induced initial chromosome damages are more severe and may lead to cell death. Detailed analysis of breaks participating in total chromosome exchanges within the first cell cycle post irradiation revealed a common hotspot located in the 3p21 region, which is a known fragile site corresponding to the band 6 in the mBand analysis. The breakpoint distribution in chromosomes collected at 7 days, but not at 14 days, post irradiation appeared similar to the distribution in cells collected within the first cell cycle post irradiation. The breakpoint distribution for human lymphocytes after radiation exposure was different from the previously published distribution for human mammary epithelial cells, indicating that interphase chromatin folding structures play a role in the distribution of radiation-induced breaks.

Full-wave acoustic and thermal modeling of transcranial ultrasound propagation and investigation of skull-induced aberration correction techniques: a feasibility study.

PubMed

Kyriakou, Adamos; Neufeld, Esra; Werner, Beat; Székely, Gábor; Kuster, Niels

2015-01-01

Transcranial focused ultrasound (tcFUS) is an attractive noninvasive modality for neurosurgical interventions. The presence of the skull, however, compromises the efficiency of tcFUS therapy, as its heterogeneous nature and acoustic characteristics induce significant distortion of the acoustic energy deposition, focal shifts, and thermal gain decrease. Phased-array transducers allow for partial compensation of skull-induced aberrations by application of precalculated phase and amplitude corrections. An integrated numerical framework allowing for 3D full-wave, nonlinear acoustic and thermal simulations has been developed and applied to tcFUS. Simulations were performed to investigate the impact of skull aberrations, the possibility of extending the treatment envelope, and adverse secondary effects. The simulated setup comprised an idealized model of the ExAblate Neuro and a detailed MR-based anatomical head model. Four different approaches were employed to calculate aberration corrections (analytical calculation of the aberration corrections disregarding tissue heterogeneities; a semi-analytical ray-tracing approach compensating for the presence of the skull; two simulation-based time-reversal approaches with and without pressure amplitude corrections which account for the entire anatomy). These impact of these approaches on the pressure and temperature distributions were evaluated for 22 brain-targets. While (semi-)analytical approaches failed to induced high pressure or ablative temperatures in any but the targets in the close vicinity of the geometric focus, simulation-based approaches indicate the possibility of considerably extending the treatment envelope (including targets below the transducer level and locations several centimeters off the geometric focus), generation of sharper foci, and increased targeting accuracy. While the prediction of achievable aberration correction appears to be unaffected by the detailed bone-structure, proper consideration of inhomogeneity is required to predict the pressure distribution for given steering parameters. Simulation-based approaches to calculate aberration corrections may aid in the extension of the tcFUS treatment envelope as well as predict and avoid secondary effects (standing waves, skull heating). Due to their superior performance, simulationbased techniques may prove invaluable in the amelioration of skull-induced aberration effects in tcFUS therapy. The next steps are to investigate shear-wave-induced effects in order to reliably exclude secondary hot-spots, and to develop comprehensive uncertainty assessment and validation procedures.

Is the presence of 6 or fewer crypt apoptotic bodies sufficient for diagnosis of graft versus host disease? A decade of experience at a single institution.

PubMed

Lin, Jingmei; Fan, Rong; Zhao, Zijin; Cummings, Oscar W; Chen, Shaoxiong

2013-04-01

Histopathology assessment is crucial for the diagnosis of graft versus host disease (GVHD), as the presence of crypt apoptosis is the cardinal criterion required. However, crypt apoptosis is not limited to GVHD; it also occurs in other conditions such as infection, drug reaction, or inflammatory reactions unrelated to GVHD. To better determine whether the presence of 6 or fewer apoptotic bodies is sufficient for the diagnosis of GVHD, we retrospectively reviewed 78 colon biopsies from 66 patients who received either hematopoietic stem cell (HSCT) or cord blood cell transplantation and whose colon biopsies exhibited apoptotic bodies. Among them, 41 cases contained 6 or fewer apoptotic bodies in the colon biopsy. These biopsies were compared with 141 colon biopsy controls that showed no significant pathologic changes as well as 16 colon biopsies with cytomegalovirus colitis from patients without a history of bone marrow transplantation. Among the 41 cases reviewed, 7 patients had coexisting GVHD in other organs (skin or liver). However, gastrointestinal symptoms of at least 4 HSCT patients whose colon biopsies contained 6 or fewer apoptotic bodies completely resolved in the absence of further intervention for GVHD. The discrepancy between pathologic findings and the clinical course may be due to confounding factors, such as infection or medication-induced injury. Our data suggest that identifying 6 or fewer crypt apoptotic bodies in colon biopsies from HSCT patients is worth reporting in order to alert the clinicians of the possibility of GVHD but not sufficient to render a diagnosis on the pathologic grounds alone. The colon biopsies containing 6 or fewer apoptotic bodies represent a heterogenous group. We suggest this group to be classified as indeterminate for GVHD, instead of diagnosing GVHD outright. Synthesis of all clinical, endoscopic, and pathologic information, including the status of infection, coexisting GVHD involvement in the other organs, and medication, is essential for confirmation of the diagnosis of GVHD.

Melatonin and pineal gland peptides are able to correct the impairment of reproductive cycles in rats.

PubMed

Arutjunyan, Alexander; Kozina, Ljudmila; Milyutina, Yulia; Korenevsky, Andrew; Stepanov, Michael; Arutyunov, Vladimir

2012-12-01

Catecholamines play an important role in the hypothalamic regulation of the synthesis and secretion of gonadotropin- releasing hormone, or gonadoliberin. We have shown that melatonin and the pineal gland peptides (epithalamine and epitalon) exert a correcting influence on the diurnal dynamics of norepinephrine (NE) in the medial preoptic area (MPA) and of dopamine (DA) in the median eminence with arcuate nuclei (ME-Arc) disturbed by single administration of the neurotoxic xenobiotic 1,2-dimethylhydrazine (DMH) in female rats. It has been found that experiments with DMH administration can be used as an animal model of female reproductive system premature aging. The investigation of epithalamine (a polypeptide preparation from the bovine pineal gland) effect on circadian rhythms disturbed by the neurotoxic compound DMH has shown a recovery of the diurnal dynamics of NE in MPA. In addition, NE was found to decrease from 9:30 till 11 o'clock, Circadian Time (CT), which was typical of control animals. Epitalon (Ala-Glu-Asp-Gly) proved to be more effective in ME-Arc. This peptide prevents the xenobiotic caused disturbance of DA diurnal rhythm, keeping this metabolite low at 5 o'clock (CT) with it having increased by 11 o'clock (CT). The data obtained suggest that the pineal gland is important for the circadian signal normalization needed for gonadoliberin surge on the day of proestrus. Melatonin and peptides of the pineal gland can be considered as effective protectors of female reproductive system from xenobiotics and premature aging.

Protective effect of vilva juice on glycoconjugate levels in experimentally induced constipation in rats.

PubMed

Padmini, R; Sabitha, K E; Devi, C S Shyamala

2004-10-01

Efficacy of vilva, a polyherbal formulation was evaluated in morphine induced constipated rats. Vilva juice, at a dose of 1.5 ml/100 g body wt was given orally for a period of 7 days. Morphine sulfate was injected to induce constipation on 8th day, 45 min before the experiments. Protein bound glycoconjungates were estimated in intestinal tissue. Altered levels of glycoconjugates were maintained at near normalcy when pretreated with vilva juice in morphine induced rats. Histological changes were observed in the colon tissue. The damage to crypts of Liberkunn in constipated rats were found to be reduced in vilva pretreated rats. Vilva, thus, offered significant protection against morphine induced constipation by way of augmenting mucus secretion.

Genotoxicity of mercury used in chromosome aberration tests.

PubMed

Akiyama, M; Oshima, H; Nakamura, M

2001-01-01

The purpose of this study was to investigate the genotoxic effects of Hg released from dental amalgams. The chromosome aberration test was conducted using original extracts and their diluted solutions of conventional type amalgam and high copper amalgam. The concentrations of Hg, Cu and Ag in the original extract of high copper amalgam were 17.64, 7.97 and 43.90 microM, respectively. Those in the original extract of conventional type amalgam were 20.63, 7.87 and 14.79 microM, respectively. 10 and 30 microM Hg(2+) were also used for comparison. The frequency of chromosome aberrations was below 5% with 0 microM Hg(2+) and with a triple dilution of high copper amalgam extract, containing 5.88 microM Hg, 14.63 microM Cu and 2.65 microM Ag. However, 9.5% of the cells showed chromosome aberrations with a quadruple dilution of conventional type amalgam, containing 5.15 microM Hg, 3.69 microM Cu and 1.96 microM Ag. The amount of Hg in the quadruple dilution of conventional type amalgam was less than that in the triple dilution of high copper amalgam extract and 10 microM Hg(2+). A concentration of 30 microM Hg(2+) caused 34.5% of the cells to show chromosome aberrations while with a two-thirds dilution of high copper amalgam extract, containing 11.76 microM Hg, 29.26 microM Cu and 5.31 microM Ag, 58.5% of the cells showed chromosome aberrations. A two-thirds dilution of high copper amalgam extract induced more chromosome aberrations than 30 microM Hg(2+), although the amount of Hg was less than 30 microM Hg(2+). A triple dilution of conventional type amalgam extract, original extracts of conventional type amalgam and high copper amalgam and 100 microM Hg(2+) were induced few metaphases. It was revealed that the conventional type amalgam induced chromosome aberrations with quadruple dilution where cell viability was about 80% and that the high copper amalgam induced a high level of chromosome aberrations with the two-thirds dilution. The effects of low level Hg on humans are not clear.

The effect of hyperthermia on the radiation response of crypt cells in mouse jejunum

NASA Technical Reports Server (NTRS)

Wilson, J. D.

1978-01-01

The effect of hyperthermia and/or gamma-radiation on the survival of intestinal crypt cells was studied in BDF sub 1 mice using a microcolony assay. Hyperthermia treatments, which in themselves caused no detectable cell lethality, inhibited the capacity of crypt cells to repair sublethal radiation damage. In addition, heat applied either before or after single radiation exposures potentiated lethal damage to crypt cells; the degree of enhancement was dependent on the time interval between treatments. At the levels of heating employed, DNA synthesis in the intestinal epithelium was significantly reduced immediately following exposure, but returned rapidly to normal levels. No further disturbances in cellular kinetics were observed for up to 10 days after heating.

Parameter dimension of turbulence-induced phase errors and its effects on estimation in phase diversity

NASA Technical Reports Server (NTRS)

Thelen, Brian J.; Paxman, Richard G.

1994-01-01

The method of phase diversity has been used in the context of incoherent imaging to estimate jointly an object that is being imaged and phase aberrations induced by atmospheric turbulence. The method requires a parametric model for the phase-aberration function. Typically, the parameters are coefficients to a finite set of basis functions. Care must be taken in selecting a parameterization that properly balances accuracy in the representation of the phase-aberration function with stability in the estimates. It is well known that over parameterization can result in unstable estimates. Thus a certain amount of model mismatch is often desirable. We derive expressions that quantify the bias and variance in object and aberration estimates as a function of parameter dimension.

Induction of chromosome aberrations in human cells by charged particles

NASA Technical Reports Server (NTRS)

Wu, H.; Durante, M.; George, K.; Yang, T. C.

1997-01-01

Chromosome aberrations induced by high-energy charged particles in normal human lymphocytes and human fibroblasts have been investigated. The charged particles included 250 MeV/nucleon protons, 290 MeV/nucleon carbon ions and 1 GeV/nucleon iron ions. The energies of the charged particles were higher than in most of the studies reported in the literature. Lymphocytes were stimulated to grow immediately after irradiation, while fibroblasts were incubated at 37 degrees C for 24 h for repair. Chromosomes were collected at the first mitosis after irradiation and chromosome aberrations were scored using the fluorescence in situ hybridization (FISH) technique with a whole-chromosome 4 probe. Chromosome aberrations were classified as reciprocal exchanges, incomplete exchanges, deletions and complex exchanges. The relative biological effectiveness (RBE) for each type of aberration was calculated by dividing a dose of 4 Gy by the dose of the charged particles producing the same effect as 4 Gy of gamma rays. Results of this study showed that complex aberrations have the highest RBE for radiation of high linear energy transfer (LET) for human lymphocytes, but for fibroblasts, the greatest effect was for incomplete exchanges. For both lymphocytes and fibroblasts, iron ions induced a similar fraction of aberrant cells.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, Lin; Department of Pharmacology, University of Nantong, Nantong; Chen, Yeru

Butylated hydroxyanisole (BHA) is widely used as an antioxidant and preservative in food, food packaging and medicines. Its chemopreventive properties are attributing to its ability to activate the transcription factor NF-E2 p45-related factor 2 (Nrf2), which directs central genetic programs of detoxification and protection against oxidative stress. This study was to investigate the histological changes of Nrf2 and its regulated phase II enzymes Nqo1, AKR1B8, and Ho-1 in wild-type (WT) and Nrf2{sup −/−} mice induced by BHA. The mice were given a 200 mg/kg oral dose of BHA daily for three days. Immunohistochemistry revealed that, in the liver from WTmore » mice, BHA increased Nqo1 staining in hepatocytes, predominately in the pericentral region. In contrast, the induction of AKR1B8 appeared mostly in hepatocytes in the periportal region. The basal and inducible Ho-1 was located almost exclusively in Kupffer cells. In the small intestine from WT mice, the inducible expression patterns of Nqo1 and AKR1B8 were nearly identical to that of Nrf2, with more intense staining in the villus than that the crypt. Conversely, Keap1 was more highly expressed in the crypt, where the proliferative cells reside. Our study demonstrates that BHA elicited differential expression patterns of phase II-detoxifying enzymes in the liver and small intestine from WT but not Nrf2{sup −/−} mice, demonstrating a cell type specific response to BHA in vivo. - Highlights: • Histological view of basal and inducible Nrf2 and its targets in vivo • Induction of detoxification enzymes by BHA is cell-type dependent. • BHA induces the expression of HO-1 in Kupffer cells.« less

Aged garlic extract protects against methotrexate-induced apoptotic cell injury of IEC-6 cells.

PubMed

Horie, Toshiharu; Li, Tiesong; Ito, Kousei; Sumi, Shin-ichiro; Fuwa, Toru

2006-03-01

Gastrointestinal toxicity is one of the most serious side effects of methotrexate (MTX) treatment. The side effects often disrupt the cancer chemotherapy. We previously reported that aged garlic extract (AGE) protects the small intestine of rats from MTX-induced damage. In this study, the protection of AGE against MTX-induced damage of IEC-6 cells originating from the rat jejunum crypt was investigated. MTX decreased the viability of IEC-6 cells, but this effect was prevented by AGE (0.5%). The MTX-induced apoptosis of IEC-6 cells was depressed by AGE. These results indicated that AGE protects IEC-6 cells from the MTX-induced damage. AGE may be useful in cancer chemotherapy with MTX because it reduces MTX-induced intestinal damage.

Persistence of radiation-induced chromosome aberrations in a long-term cell culture.

PubMed

Duran, Assumpta; Barquinero, Joan Francesc; Caballín, María Rosa; Ribas, Montserrat; Barrios, Leonardo

2009-04-01

The aim of the present study was to evaluate the persistence of chromosome aberrations induced by X rays. FISH painting and mFISH techniques were applied to long-term cultures of irradiated cells. With painting, at 2 Gy the frequency of apparently simple translocations remained almost invariable during all the culture, whereas at 4 Gy a rapid decline was observed between the first and the second samples, followed by a slight decrease until the end of the culture. Apparently simple dicentrics and complex aberrations disappeared after the first sample at 2 and 4 Gy. By mFISH, at 2 Gy the frequency of complete plus one-way translocations remained invariable between the first and last sample, but at 4 Gy a 60% decline was observed. True incomplete simple translocations disappeared at 2 and 4 Gy, indicating that incompleteness could be a factor to consider when the persistence of translocations is analyzed. The analysis by mFISH showed that the frequency of complex aberrations and their complexity increased with dose and tended to disappear in the last sample. Our results indicate that the influence of dose on the decrease in the frequency of simple translocations with time postirradiation cannot be fully explained by the disappearance of true incomplete translocations and complex aberrations. The chromosome involvement was random for radiation-induced exchange aberrations and non-random for total aberrations. Chromosome 7 showed the highest deviations from expected, being less and more involved than expected in the first and last samples, respectively. Some preferential chromosome-chromosome associations were observed, including a coincidence with a cluster from radiogenic chromosome aberrations described in other studies.

DNA-based watermarks using the DNA-Crypt algorithm.

PubMed

Heider, Dominik; Barnekow, Angelika

2007-05-29

The aim of this paper is to demonstrate the application of watermarks based on DNA sequences to identify the unauthorized use of genetically modified organisms (GMOs) protected by patents. Predicted mutations in the genome can be corrected by the DNA-Crypt program leaving the encrypted information intact. Existing DNA cryptographic and steganographic algorithms use synthetic DNA sequences to store binary information however, although these sequences can be used for authentication, they may change the target DNA sequence when introduced into living organisms. The DNA-Crypt algorithm and image steganography are based on the same watermark-hiding principle, namely using the least significant base in case of DNA-Crypt and the least significant bit in case of the image steganography. It can be combined with binary encryption algorithms like AES, RSA or Blowfish. DNA-Crypt is able to correct mutations in the target DNA with several mutation correction codes such as the Hamming-code or the WDH-code. Mutations which can occur infrequently may destroy the encrypted information, however an integrated fuzzy controller decides on a set of heuristics based on three input dimensions, and recommends whether or not to use a correction code. These three input dimensions are the length of the sequence, the individual mutation rate and the stability over time, which is represented by the number of generations. In silico experiments using the Ypt7 in Saccharomyces cerevisiae shows that the DNA watermarks produced by DNA-Crypt do not alter the translation of mRNA into protein. The program is able to store watermarks in living organisms and can maintain the original information by correcting mutations itself. Pairwise or multiple sequence alignments show that DNA-Crypt produces few mismatches between the sequences similar to all steganographic algorithms.

Association of iris crypts with acute primary angle closure.

PubMed

Koh, Victor; Chua, Jacqueline; Shi, Yuan; Thakku, Sri Gowtham; Lee, Ryan; Nongpiur, Monisha E; Baskaran, Mani; Kumar, Rajesh S; Perera, Shamira; Aung, Tin; Cheng, Ching-Yu

2017-10-01

To determine the relationship between iris surface features and acute primary angle closure (APAC) in eyes with angle closure. Case-control study involving Asian patients diagnosed with previous APAC, primary angle closure suspect (PACS), primary angle closure (PAC) and primary angle closure glaucoma (PACG) at an eye centre in Singapore between August 2012 and January 2015. Participants underwent ophthalmic examination and digital slit-lamp iris photography. Iris surface features were graded based on crypts, furrows and colour. Fellow eyes of APAC were compared with PACS and PAC/PACG eyes with regard to their iris surface features. Occurrence of APAC. A total of 309 patients (71 APAC, 139 PACS, 47 PAC and 52 PACG) were included (mean age: 67.7±7.2 years and 36.6% male). Compared with PACS, higher crypt grade was significantly associated with lower odds of APAC (OR=0.58 for one grade higher in crypt grade; p=0.027, adjusted for age, gender, ethnicity and pupil diameter). The results remained similar when compared with PAC/PACG group (OR=0.58 for one grade higher in crypt grade; p=0.043). We did not observe any significant associations between iris furrows or colour with presence of APAC. Our study comprising Asian eyes with angle closure suggests that the presence of a higher crypt grading may be protective for APAC. As such, assessing iris surface architecture for crypts could be a new measure for risk stratification of developing APAC in eyes with angle closure. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

DNA-based watermarks using the DNA-Crypt algorithm

PubMed Central

Heider, Dominik; Barnekow, Angelika

2007-01-01

Background The aim of this paper is to demonstrate the application of watermarks based on DNA sequences to identify the unauthorized use of genetically modified organisms (GMOs) protected by patents. Predicted mutations in the genome can be corrected by the DNA-Crypt program leaving the encrypted information intact. Existing DNA cryptographic and steganographic algorithms use synthetic DNA sequences to store binary information however, although these sequences can be used for authentication, they may change the target DNA sequence when introduced into living organisms. Results The DNA-Crypt algorithm and image steganography are based on the same watermark-hiding principle, namely using the least significant base in case of DNA-Crypt and the least significant bit in case of the image steganography. It can be combined with binary encryption algorithms like AES, RSA or Blowfish. DNA-Crypt is able to correct mutations in the target DNA with several mutation correction codes such as the Hamming-code or the WDH-code. Mutations which can occur infrequently may destroy the encrypted information, however an integrated fuzzy controller decides on a set of heuristics based on three input dimensions, and recommends whether or not to use a correction code. These three input dimensions are the length of the sequence, the individual mutation rate and the stability over time, which is represented by the number of generations. In silico experiments using the Ypt7 in Saccharomyces cerevisiae shows that the DNA watermarks produced by DNA-Crypt do not alter the translation of mRNA into protein. Conclusion The program is able to store watermarks in living organisms and can maintain the original information by correcting mutations itself. Pairwise or multiple sequence alignments show that DNA-Crypt produces few mismatches between the sequences similar to all steganographic algorithms. PMID:17535434

Association of iris surface features with iris parameters assessed by swept-source optical coherence tomography in Asian eyes.

PubMed

Tun, Tin A; Chua, Jacqueline; Shi, Yuan; Sidhartha, Elizabeth; Thakku, Sri Gowtham; Shei, William; Tan, Marcus Chiang Lee; Quah, Joanne Hui Min; Aung, Tin; Cheng, Ching-Yu

2016-12-01

To characterise the association of iris surface features (crypts, furrows and colour) with iris volume and curvature assessed by swept-source optical coherence tomography (SSOCT) in Asian eyes. Iris crypts (by number and size) and furrows (by number and circumferential extent) were graded from iris photographs. Iris colour was measured by a customised algorithm written on MATLAB (MathWorks, Natick, Massachusetts, USA). The iris was imaged by SSOCT (SS-1000, CASIA, Tomey, Nagoya, Japan). The associations of surface features with iris parameters were analysed using a generalised estimating equation. A total of 1704 subjects (3297 eyes) were included in the analysis. The majority was Chinese (86.4%), and 63.2% were females, and their mean age (±SD) was 61.4±6.6 years. After adjusting for age, sex, ethnicity, pupil size and corneal arcus, higher iris crypt grade was independently associated with smaller iris volume (β=-0.54, p<0.001), whereas darker irides and higher iris furrow grade were associated with larger iris volume (β=-0.041, p<0.001) and (β=0.233, p<0.001), respectively. Lighter coloured irides with more crypts and/or more furrows were also associated with less convexity (crypts: β=-0.003, p=0.03; furrows: β=-0.004, p=0.007; and colour: β=-0.001, p=0.005). Iris surface features were highly correlated with iris volume and curvature. Irides with more crypts have a smaller volume; and darker irides with more furrows have a larger volume. Lighter irides with more crypts and/or furrows have less convexity. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Cellular chloride and bicarbonate retention alters intracellular pH regulation in Cftr KO crypt epithelium

PubMed Central

Walker, Nancy M.; Liu, Jinghua; Stein, Sydney R.; Stefanski, Casey D.; Strubberg, Ashlee M.

2015-01-01

Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR), an anion channel providing a major pathway for Cl− and HCO3− efflux across the apical membrane of the epithelium. In the intestine, CF manifests as obstructive syndromes, dysbiosis, inflammation, and an increased risk for gastrointestinal cancer. Cftr knockout (KO) mice recapitulate CF intestinal disease, including intestinal hyperproliferation. Previous studies using Cftr KO intestinal organoids (enteroids) indicate that crypt epithelium maintains an alkaline intracellular pH (pHi). We hypothesized that Cftr has a cell-autonomous role in downregulating pHi that is incompletely compensated by acid-base regulation in its absence. Here, 2′,7′-bis(2-carboxyethyl)-5(6)-carboxyfluorescein microfluorimetry of enteroids showed that Cftr KO crypt epithelium sustains an alkaline pHi and resistance to cell acidification relative to wild-type. Quantitative real-time PCR revealed that Cftr KO enteroids exhibit downregulated transcription of base (HCO3−)-loading proteins and upregulation of the basolateral membrane HCO3−-unloader anion exchanger 2 (Ae2). Although Cftr KO crypt epithelium had increased Ae2 expression and Ae2-mediated Cl−/HCO3− exchange with maximized gradients, it also had increased intracellular Cl− concentration relative to wild-type. Pharmacological reduction of intracellular Cl− concentration in Cftr KO crypt epithelium normalized pHi, which was largely Ae2-dependent. We conclude that Cftr KO crypt epithelium maintains an alkaline pHi as a consequence of losing both Cl− and HCO3− efflux, which impairs pHi regulation by Ae2. Retention of Cl− and an alkaline pHi in crypt epithelium may alter several cellular processes in the proliferative compartment of Cftr KO intestine. PMID:26542396

{beta}-Catenin stabilization imparts crypt progenitor phenotype to hyperproliferating colonic epithelia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sellin, Joseph H.; Wang Yu; Singh, Pomila

2009-01-01

Utilizing the Citrobacter rodentium (CR)-induced transmissible murine colonic hyperplasia (TMCH) model, we provide mechanistic basis of changes in {beta}-catenin/APC/CKI{epsilon} leading to progression and/or regression of hyperplasia in vivo. In response to CR-induced TMCH, crypt lengths increased significantly between days 6-27 post-infection, followed by a steep decline by day 34. {beta}-Cat{sup 45}/total {beta}-catenin were elevated on day 1 post-infection, preceding changes in crypt length, and persisted for 27 days before declining by day 34. Importantly, cellular CKI{epsilon} and {beta}-catenin co-immunoprecipitated and exhibited remarkable parallel changes in kinetics during hyperplasia/regression phases. {beta}-catenin, phosphorylated at Ser33,37 and Thr41 ({beta}-cat{sup 33,37/41}), was low tillmore » day 12, followed by gradual increase until day 27 before declining by day 34. GSK-3{beta} exhibited significant Ser{sup 9}-phosphorylation/inactivation at days 6-12 with partial recovery at days 27-34. Wild type (wt) APC (p312) levels increased at day 6 with transient proteolysis/truncation to p130 form between days 12 and 15; p312 reappeared by day 19 and returned to baseline by day 34. The kinetics of {beta}-Cat{sup 45}/{beta}-catenin nuclear accumulation and acetylation (Ac-{beta}-Cat{sup Lys49}) from days 6 to 27, followed by loss of phosphorylation/acetylation by day 34 was almost identical; Tcf-4 co-immunoprecipitated with {beta}-Cat{sup 45}/{beta}-catenin and localized immunohistochemically to {beta}-Cat{sup 41/45}-positive regions leading to elevated cyclin D1 expression, during the hyperproliferative, but not regression phases of TMCH. CKI{epsilon} mediated phosphorylation of {beta}-Cat{sup 45}, resulting in stabilization/nuclear translocation of {beta}-Cat{sup 45} may be critical for maintaining proliferation at days 6-27. Reversal of GSK-3{beta} phosphorylation and APC changes may be equally critical during the regression phase from days 27 to 34.« less

Injection of celiac disease patient sera or immunoglobulins to mice reproduces a condition mimicking early developing celiac disease.

PubMed

Kalliokoski, Suvi; Caja, Sergio; Frias, Rafael; Laurila, Kaija; Koskinen, Outi; Niemelä, Onni; Mäki, Markku; Kaukinen, Katri; Korponay-Szabó, Ilma R; Lindfors, Katri

2015-01-01

Typical features of celiac disease are small-bowel villus atrophy, crypt hyperplasia, and inflammation which develop gradually concomitant with ingestion of gluten. In addition, patients have anti-transglutaminase 2 (TG2) autoantibodies in their serum and tissues. The aim of this study was to establish whether celiac disease can be passively transferred to mice by serum or immunoglobulins. Serum aliquots or purified immunoglobulins (Ig) were intraperitoneally injected into Hsd:Athymic Nude-Foxn1nu mice for 8 or 27 days. As mice do not have proper IgA transport from peritoneum to blood, sera with a high content of IgG class anti-TG2 antibodies from untreated IgA-deficient celiac patients were used. Mouse sera were tested for celiac disease-specific autoantibodies, and several tissues were analyzed for autoantibody deposits targeted to TG2. Morphological assessment was made of the murine small intestinal mucosa. Injection of celiac disease patient sera or total IgG led to a significant delay in weight gain and mild diarrhea in a subset of mice. The mice injected with celiac patient sera or IgG had significantly decreased villus height crypt depth (Vh/CrD) ratios and celiac disease-specific autoantibody deposits targeted to TG2 in several tissues, including the small intestine. None of these features were observed in control mice. We conclude that administration of IgA-deficient celiac disease patient serum or total IgG induces both deterioration of the intestinal mucosa and clinical features of celiac disease in mice. The experimentally induced condition in the mice injected with patient serum or IgG resembles early developing celiac disease in humans. Celiac disease patient sera or total IgG was injected into athymic mice. A significant delay in weight gain and mild diarrhea was observed. Mice evinced significantly decreased villus height crypt depth ratios. Celiac disease-specific autoantibody deposits were present in several tissues. The condition in mice resembles early stage celiac disease in humans.

Effect of dietary seaweed extracts and fish oil supplementation in sows on performance, intestinal microflora, intestinal morphology, volatile fatty acid concentrations and immune status of weaned pigs.

PubMed

Leonard, S G; Sweeney, T; Bahar, B; Lynch, B P; O'Doherty, J V

2011-02-01

A 2x2 factorial experiment (ten sows per treatment) was conducted to investigate the effect of maternal dietary supplementation with a seaweed extract (SWE; 0 v. 10·0 g/d) and fish oil (FO; 0 v. 100 g/d) inclusion from day 109 of gestation until weaning (day 26) on pig performance post-weaning (PW) and intestinal morphology, selected microflora and immune status of pigs 9 d PW. The SWE contained laminarin (10 %), fucoidan (8 %) and ash (82 %) and the FO contained 40 % EPA and 25 % DHA. Pigs weaned from SWE-supplemented sows had higher daily gain (P=0·063) between days 0 and 21 PW and pigs weaned from FO-supplemented sows had higher daily gain (P<0·05) and gain to feed ratio (P<0·01) between days 7 and 14 PW. There was an interaction between maternal SWE and FO supplementation on caecal Escherichia coli numbers (P<0·05) and the villous height to crypt depth ratio in the ileum (P<0·01) and jejunum (P<0·05) in pigs 9 d PW. Pigs weaned from SWE-supplemented sows had lower caecal E. coli and a higher villous height to crypt depth ratio in the ileum and jejunum compared with non-SWE-supplemented sows (P<0·05). There was no effect of SWE on E. coli numbers and villous height to crypt depth ratio with FO inclusion. Maternal FO supplementation induced an increase in colonic mRNA abundance of IL-1α and IL-6 (P<0·05), while SWE supplementation induced an increase in ileal TNF-α (P<0·01) and colonic TFF3 mRNA expression (P<0·05). In conclusion, these results demonstrate that SWE and FO supplementation to the maternal diet influenced the gastrointestinal environment and performance of the weaned pig.

Regulators of Intestinal Epithelial Migration in Sepsis.

PubMed

Meng, Mei; Klingensmith, Nathan J; Liang, Zhe; Lyons, John D; Fay, Katherine T; Chen, Ching-Wen; Ford, Mandy L; Coopersmith, Craig M

2018-02-08

The gut is a continuously renewing organ, with cell proliferation, migration and death occurring rapidly under basal conditions. Since the impact of critical illness on cell movement from crypt base to villus tip is poorly understood, the purpose of this study was to determine how sepsis alters enterocyte migration. Wild type, transgenic and knockout mice were injected with 5-bromo-2'deoxyuridine (BrdU) to label cells in S phase before and after the onset of cecal ligation and puncture and were sacrificed at pre-determined endpoints to determine distance proliferating cells migrated up the crypt-villus unit. Enterocyte migration rate was decreased from 24-96 hours following sepsis. BrdU was not detectable on villi 6 days after sham laparotomy, meaning all cells had migrated the length of the gut and been exfoliated into its lumen. However, BrdU positive cells were detectable on villi 10 days after sepsis. Multiple components of gut integrity altered enterocyte migration. Sepsis decreased crypt proliferation, which further slowed enterocyte transit as mice injected with BrdU after the onset of sepsis (decreased proliferation) had slower migration than mice injected with BrdU prior to the onset of sepsis (normal proliferation). Decreasing intestinal apoptosis via gut-specific overexpression of Bcl-2 prevented sepsis-induced slowing of enterocyte migration. In contrast, worsened intestinal hyperpermeability by genetic deletion of JAM-A increased enterocyte migration. Sepsis therefore significantly slows enterocyte migration, and intestinal proliferation, apoptosis and permeability all affect migration time, which can potentially be targeted both genetically and pharmacologically.

Activation of AMPK Inhibits Cholera Toxin Stimulated Chloride Secretion in Human and Murine Intestine

PubMed Central

Hoekstra, Nadia; Collins, Danielle; Collaco, Anne; Baird, Alan W.; Winter, Desmond C.; Ameen, Nadia; Geibel, John P.; Kopic, Sascha

2013-01-01

Increased intestinal chloride secretion through chloride channels, such as the cystic fibrosis transmembrane conductance regulator (CFTR), is one of the major molecular mechanisms underlying enterotoxigenic diarrhea. It has been demonstrated in the past that the intracellular energy sensing kinase, the AMP-activated protein kinase (AMPK), can inhibit CFTR opening. We hypothesized that pharmacological activation of AMPK can abrogate the increased chloride flux through CFTR occurring during cholera toxin (CTX) mediated diarrhea. Chloride efflux was measured in isolated rat colonic crypts using real-time fluorescence imaging. AICAR and metformin were used to activate AMPK in the presence of the secretagogues CTX or forskolin (FSK). In order to substantiate our findings on the whole tissue level, short-circuit current (SCC) was monitored in human and murine colonic mucosa using Ussing chambers. Furthermore, fluid accumulation was measured in excised intestinal loops. CTX and forskolin (FSK) significantly increased chloride efflux in isolated colonic crypts. The increase in chloride efflux could be offset by using the AMPK activators AICAR and metformin. In human and mouse mucosal sheets, CTX and FSK increased SCC. AICAR and metformin inhibited the secretagogue induced rise in SCC, thereby confirming the findings made in isolated crypts. Moreover, AICAR decreased CTX stimulated fluid accumulation in excised intestinal segments. The present study suggests that pharmacological activation of AMPK effectively reduces CTX mediated increases in intestinal chloride secretion, which is a key factor for intestinal water accumulation. AMPK activators may therefore represent a supplemental treatment strategy for acute diarrheal illness. PMID:23935921

The fate of epithelial cells in the human large intestine.

PubMed

Barkla, D H; Gibson, P R

1999-08-01

One hundred and forty biopsies of the colon and rectum, collected during routine colonoscopies of 51 patients aged 19 to 74 years, were examined using light microscopy and transmission and scanning electron microscopy. The results indicated that surface epithelial cells undergo apoptosis, passing through fenestrations in the basement membrane to where they enter the lamina propria and are taken up by macrophages; and it is hypothesized that apoptotic cells are carried through the fenestrations on a current of fluid. The study also found that epithelial cells positioned over the crypts are better attached and more robust than those more distant from the crypt opening; and it is further hypothesized that, after reaching the top of the crypts, some goblet cells cease secreting mucus and pass onto the surface compartment of absorptive cells. An unexpected finding was that the lower regions of the crypts commonly contain isolated necrotic colonocytes. Apoptotic cells were rarely observed in the crypt epithelium. The findings of this study support the "recycling" model of epithelial cell death in the surface compartment of the human colon.

SNOM Imaging of a Crypt-Like Feature in Adenocarcinoma Associated with Barrett's Oesophagus

DOE PAGES

Craig, Timothy; Smith, Andrew D.; Holder, Gareth M.; ...

2018-01-05

The development of more accurate and sensitive diagnostic techniques is a key factor in efforts to improve cancer survival rates. The technique of infrared aperture fibre scanning near-field optical microscopy (IR-SNOM),together with radiation from the infrared free-electron laser (IR-FEL) on ALICEat Daresbury Laboratory (UK), has been used to obtain IR images of a crypt-like feature and the surrounding tissue; the tissue was taken from a patient with oesophageal adenocarcinoma and with a history of Barrett’s oesophagus. We have shown that the DNA signal is enhanced relative to other contributions in the region of the crypt, and the glycoprotein signal showsmore » a less pronounced increase in the region of the crypt. The Amide II signal is found to be anti-correlated with the DNA and glycoprotein profiles. The absorbance of the Amide II signal is found to differ for three different types of cancer tissue. In conclusion, high-resolution IR images of the crypt reveal additional structure that would not be resolved in diffraction-limited techniques.« less

Orphan Gpr182 suppresses ERK-mediated intestinal proliferation during regeneration and adenoma formation

PubMed Central

Kechele, Daniel O.; Blue, R. Eric; Zwarycz, Bailey; Espenschied, Scott T.; Mah, Amanda T.; Siegel, Marni B.; Perou, Charles M.; Ding, Shengli; Magness, Scott T.; Lund, P. Kay

2017-01-01

Orphan GPCRs provide an opportunity to identify potential pharmacological targets, yet their expression patterns and physiological functions remain challenging to elucidate. Here, we have used a genetically engineered knockin reporter mouse to map the expression pattern of the Gpr182 during development and adulthood. We observed that Gpr182 is expressed at the crypt base throughout the small intestine, where it is enriched in crypt base columnar stem cells, one of the most active stem cell populations in the body. Gpr182 knockdown had no effect on homeostatic intestinal proliferation in vivo, but led to marked increases in proliferation during intestinal regeneration following irradiation-induced injury. In the ApcMin mouse model, which forms spontaneous intestinal adenomas, reductions in Gpr182 led to more adenomas and decreased survival. Loss of Gpr182 enhanced organoid growth efficiency ex vivo in an EGF-dependent manner. Gpr182 reduction led to increased activation of ERK1/2 in basal and challenge models, demonstrating a potential role for this orphan GPCR in regulating the proliferative capacity of the intestine. Importantly, GPR182 expression was profoundly reduced in numerous human carcinomas, including colon adenocarcinoma. Together, these results implicate Gpr182 as a negative regulator of intestinal MAPK signaling–induced proliferation, particularly during regeneration and adenoma formation. PMID:28094771

Analysis of Radiation-Induced Chromosomal Aberrations on a Cell-by-Cell Basis after Alpha-Particle Microbeam Irradiation: Experimental Data and Simulations.

PubMed

Testa, Antonella; Ballarini, Francesca; Giesen, Ulrich; Gil, Octávia Monteiro; Carante, Mario P; Tello, John; Langner, Frank; Rabus, Hans; Palma, Valentina; Pinto, Massimo; Patrono, Clarice

2018-06-01

There is a continued need for further clarification of various aspects of radiation-induced chromosomal aberration, including its correlation with radiation track structure. As part of the EMRP joint research project, Biologically Weighted Quantities in Radiotherapy (BioQuaRT), we performed experimental and theoretical analyses on chromosomal aberrations in Chinese hamster ovary cells (CHO-K1) exposed to α particles with final energies of 5.5 and 17.8 MeV (absorbed doses: ∼2.3 Gy and ∼1.9 Gy, respectively), which were generated by the microbeam at the Physikalisch-Technische Bundesanstalt (PTB) in Braunschweig, Germany. In line with the differences in linear energy transfer (approximately 85 keV/μm for 5.5 MeV and 36 keV/μm for 17.8 MeV α particles), the 5.5 MeV α particles were more effective than the 17.8 MeV α particles, both in terms of the percentage of aberrant cells (57% vs. 33%) and aberration frequency. The yield of total aberrations increased by a factor of ∼2, although the increase in dicentrics plus centric rings was less pronounced than in acentric fragments. The experimental data were compared with Monte Carlo simulations based on the BIophysical ANalysis of Cell death and chromosomal Aberrations model (BIANCA). This comparison allowed interpretation of the results in terms of critical DNA damage [cluster lesions (CLs)]. More specifically, the higher aberration yields observed for the 5.5 MeV α particles were explained by taking into account that, although the nucleus was traversed by fewer particles (nominally, 11 vs. 25), each particle was much more effective (by a factor of ∼3) at inducing CLs. This led to an increased yield of CLs per cell (by a factor of ∼1.4), consistent with the increased yield of total aberrations observed in the experiments.

Fluorescence contrast-enhanced proliferative lesion imaging by enema administration of indocyanine green in a rat model of colon carcinogenesis

PubMed Central

Onda, Nobuhiko; Mizutani-Morita, Reiko; Yamashita, Susumu; Nagahara, Rei; Matsumoto, Shinya; Yoshida, Toshinori; Shibutani, Makoto

2017-01-01

The fluorescent contrast agent indocyanine green (ICG) is approved by the Food and Drug Administration for clinical applications. We previously reported that cultured human colon tumor cells preferentially take up ICG by endocytic activity in association with disruption of their tight junctions. The present study explored ICG availability in fluorescence imaging of the colon to identify proliferative lesions during colonoscopy. The cellular uptake of ICG in cultured rat colon tumor cells was examined using live-cell imaging. Colon lesions in rats administered an ICG-containing enema were further assessed in rats with azoxymethane-induced colon carcinogenesis, using in vivo endoscopy, ex vivo microscopy, and immunofluorescence microscopy. The uptake of ICG by the cultured cells was temperature-dependent. The intracellular retention of the dye in the membrane trafficking system suggested endocytosis as the uptake mechanism. ICG administered via enema accumulated in colon proliferative lesions ranging from tiny aberrant crypt foci to adenomas and localized in proliferating cells. Fluorescence endoscopy detected these ICG-positive colonic proliferative lesions in vivo. The immunoreactivity of the tight-junction molecule occludin was altered in the proliferative lesions, suggesting the disruption of the integrity of tight junctions. These results suggest that fluorescence contrast-enhanced imaging following the administration of an ICG-containing enema can enhance the detection of mucosal proliferative lesions of the colon during colonoscopy. The tissue preference of ICG in the rat model evaluated in this study can be attributed to the disruption of tight junctions, which in turn promotes endocytosis by proliferative cells and the cellular uptake of ICG. PMID:29163827

Enantiomeric cannabidiol derivatives: synthesis and binding to cannabinoid receptors.

PubMed

Hanus, Lumír O; Tchilibon, Susanna; Ponde, Datta E; Breuer, Aviva; Fride, Ester; Mechoulam, Raphael

2005-03-21

(-)-Cannabidiol (CBD) is a major, non psychotropic constituent of cannabis. It has been shown to cause numerous physiological effects of therapeutic importance. We have reported that CBD derivatives in both enantiomeric series are of pharmaceutical interest. Here we describe the syntheses of the major CBD metabolites, (-)-7-hydroxy-CBD and (-)-CBD-7-oic acid and their dimethylheptyl (DMH) homologs, as well as of the corresponding compounds in the enantiomeric (+)-CBD series. The starting materials were the respective CBD enantiomers and their DMH homologs. The binding of these compounds to the CB(1) and CB(2) cannabinoid receptors are compared. Surprisingly, contrary to the compounds in the (-) series, which do not bind to the receptors, most of the derivatives in the (+) series bind to the CB(1) receptor in the low nanomole range. Some of these compounds also bind weakly to the CB(2) receptor.

Highly selectively monitoring heavy and transition metal ions by a fluorescent sensor based on dipeptide.

PubMed

Neupane, Lok Nath; Thirupathi, Ponnaboina; Jang, Sujung; Jang, Min Jung; Kim, Jung Hwa; Lee, Keun-Hyeung

2011-09-15

Fluorescent sensor (DMH) based on dipeptide was efficiently synthesized in solid phase synthesis. The dipeptide sensor shows sensitive response to Ag(I), Hg(II), and Cu(II) among 14 metal ions in 100% aqueous solution. The fluorescent sensor differentiates three heavy metal ions by response type; turn on response to Ag(I), ratiometric response to Hg(II), and turn off detection of Cu(II). The detection limits of the sensor for Ag(I) and Cu(II) were much lower than the EPA's drinking water maximum contaminant levels (MCL). Specially, DMH penetrated live cells and detected intracellular Ag(+) by turn on response. We described the fluorescent change, binding affinity, detection limit for the metal ions. The study of a heavy metal-responsive sensor based on dipeptide demonstrates its potential utility in the environment field. Copyright © 2011 Elsevier B.V. All rights reserved.

Individual crypt genetic heterogeneity and the origin of metaplastic glandular epithelium in human Barrett’s oesophagus

PubMed Central

Leedham, S J; Preston, S L; McDonald, S A C; Elia, G; Bhandari, P; Poller, D; Harrison, R; Novelli, M R; Jankowski, J A; Wright, N A

2008-01-01

Objectives: Current models of clonal expansion in human Barrett’s oesophagus are based upon heterogenous, flow-purified biopsy analysis taken at multiple segment levels. Detection of identical mutation fingerprints from these biopsy samples led to the proposal that a mutated clone with a selective advantage can clonally expand to fill an entire Barrett’s segment at the expense of competing clones (selective sweep to fixation model). We aimed to assess clonality at a much higher resolution by microdissecting and genetically analysing individual crypts. The histogenesis of Barrett’s metaplasia and neo-squamous islands has never been demonstrated. We investigated the oesophageal gland squamous ducts as the source of both epithelial sub-types. Methods: Individual crypts across Barrett’s biopsy and oesophagectomy blocks were dissected. Determination of tumour suppressor gene loss of heterozygosity patterns, p16 and p53 point mutations were carried out on a crypt-by-crypt basis. Cases of contiguous neo-squamous islands and columnar metaplasia with oesophageal squamous ducts were identified. Tissues were isolated by laser capture microdissection and genetically analysed. Results: Individual crypt dissection revealed mutation patterns that were masked in whole biopsy analysis. Dissection across oesophagectomy specimens demonstrated marked clonal heterogeneity, with multiple independent clones present. We identified a p16 point mutation arising in the squamous epithelium of the oesophageal gland duct, which was also present in a contiguous metaplastic crypt, whereas neo-squamous islands arising from squamous ducts were wild-type with respect to surrounding Barrett’s dysplasia. Conclusions: By studying clonality at the crypt level we demonstrate that Barrett’s heterogeneity arises from multiple independent clones, in contrast to the selective sweep to fixation model of clonal expansion previously described. We suggest that the squamous gland ducts situated throughout the oesophagus are the source of a progenitor cell that may be susceptible to gene mutation resulting in conversion to Barrett’s metaplastic epithelium. Additionally, these data suggest that wild-type ducts may be the source of neo-squamous islands. PMID:18305067

Radiation-induced chromosomal instability in BALB/c and C57BL/6 mice: the difference is as clear as black and white

NASA Technical Reports Server (NTRS)

Ponnaiya, B.; Cornforth, M. N.; Ullrich, R. L.

1997-01-01

Genomic instability has been proposed to be the earliest step in radiation-induced tumorigenesis. It follows from this hypothesis that individuals highly susceptible to induction of tumors by radiation should exhibit enhanced radiation-induced instability. BALB/c white mice are considerably more sensitive to radiation-induced mammary cancer than C57BL/6 black mice. In this study, primary mammary epithelial cell cultures from these two strains were examined for the "delayed" appearance of chromosomal aberrations after exposure to 137Cs gamma radiation, as a measure of radiation-induced genomic instability. As expected, actively dividing cultures from both strains showed a rapid decline of initial asymmetrical aberrations with time postirradiation. However, after 16 population doublings, cells from BALB/c mice exhibited a marked increase in the frequency of chromatid-type breaks and gaps which remained elevated throughout the time course of the experiment (28 doublings). No such effect was observed for the cells of C57BL/6 mice; after the rapid clearance of initial aberrations, the frequency of chromatid-type aberrations in the irradiated population remained at or near those of nonirradiated controls. These results demonstrate a correlation between the latent expression of chromosomal damage in vitro and susceptibility for mammary tumors, and provide further support for the central role of radiation-induced instability in the process of tumorigenesis.

Social Isolation Modulates CLOCK Protein and Beta-Catenin Expression Pattern in Gonadotropin-Inhibitory Hormone Neurons in Male Rats.

PubMed

Teo, Chuin Hau; Soga, Tomoko; Parhar, Ishwar S

2017-01-01

Postweaning social isolation reduces the amplitude of the daily variation of CLOCK protein in the brain and induces lower reproductive activity. Gonadotropin-inhibitory hormone (GnIH) acts as an inhibitor in the reproductive system and has been linked to stress. Social isolation has been shown to lower neuronal activity of GnIH-expressing neurons in the dorsomedial hypothalamus (DMH). The exact mechanism by which social isolation may affect GnIH is still unclear. We investigated the impact of social isolation on regulatory cellular mechanisms in GnIH neurons. We examined via immunohistochemistry the expression of CLOCK protein at four different times throughout the day in GnIH cells tagged with enhanced fluorescent green protein (EGFP-GnIH) in 9-week-old adult male rats that have been raised for 6 weeks under postweaning social isolation and compared them with group-raised control rats of the same age. We also studied the expression of β-catenin-which has been shown to be affected by circadian proteins such as Bmal1-in EGFP-GnIH neurons to determine whether it could play a role in linking CLOCK in GnIH neurons. We found that social isolation modifies the pattern of CLOCK expression in GnIH neurons in the DMH. Socially isolated rats displayed greater CLOCK expression in the dark phase, while control rats displayed increased CLOCK expression in the light phase. Furthermore, β-catenin expression pattern in GnIH cells was disrupted by social isolation. This suggests that social isolation triggers changes in CLOCK and GnIH expression, which may be associated with an increase in nuclear β-catenin during the dark phase.

A Monte-Carlo Model for the Formation of Radiation-induced Chromosomal Aberrations

NASA Technical Reports Server (NTRS)

Ponomarev, Artem L.; Cornforth, Michael N.; Loucas, Brad D.; Cucinotta, Francis A.

2009-01-01

Purpose: To simulate radiation-induced chromosome aberrations in mammalian cells (e.g., rings, translocations, and dicentrics) and to calculate their frequency distributions following exposure to DNA double strand breaks (DSBs) produced by high-LET ions. Methods: The interphase genome was assumed to be comprised of a collection of 2 kbp rigid-block monomers following the random-walk geometry. Additional details for the modeling of chromosomal structure, such as chromosomal domains and chromosomal loops, were included. A radial energy profile for heavy ion tracks was used to simulate the high-LET pattern of induced DSBs. The induced DSB pattern depended on the ion charge and kinetic energy, but always corresponded to the DSB yield of 25 DSBs/cell/Gy. The sum of all energy contributions from Poisson-distributed particle tracks was taken to account for all possible one-track and multi-track effects. The relevant output of the model was DNA fragments produced by DSBs. The DSBs, or breakpoints, were defined by (x, y, z, l) positions, where x, y, z were the Euclidian coordinates of a DSB, and where l was the relative position along the genome. Results: The code was used to carry out Monte Carlo simulations for DSB rejoinings at low doses. The resulting fragments were analyzed to estimate the frequencies of specific types of chromosomal aberrations. Histograms for relative frequencies of chromosomal aberrations and P.D.F.s (probability density functions) of a given aberration type were produced. The relative frequency of dicentrics to rings was compared to empirical data to calibrate rejoining probabilities. Of particular interest was the predicted distribution of ring sizes, irrespective of their frequencies relative to other aberrations. Simulated ring sizes were . 4 kbp, which are far too small to be observed experimentally (i.e., by microscopy) but which, nevertheless, are conjectured to exist. Other aberrations, for example, inversions, translocations, as well as multi-centrics were also recorded. Conclusion: High-LET DNA damage affects the frequencies of chromosomal aberrations. The ratio of rings to dicentrics is correct for the genomic size cut-offs corresponding to available experimental data. The present work predicts a relative abundance of small rings following irradiation by heavy ions.

Urokinase and the intestinal mucosa: evidence for a role in epithelial cell turnover

PubMed Central

Gibson, P; Birchall, I; Rosella, O; Albert, V; Finch, C; Barkla, D; Young, G

1998-01-01

Background—The functions of urokinase in intestinal epithelia are unknown. 
Aims—To determine the relation of urokinase expressed by intestinal epithelial cells to their position in the crypt-villus/surface axis and of mucosal urokinase activity to epithelial proliferative kinetics in the distal colon. 
Methods—Urokinase expression was examined immunohistochemically in human intestinal mucosa. Urokinase activity was measured colorimetrically in epithelial cells isolated sequentially from the crypt-villus axis of the rat small intestine. In separate experiments, urokinase activity and epithelial kinetics (measured stathmokinetically) were measured in homogenates of distal colonic mucosa of 14 groups of eight rats fed diets known to alter epithelial turnover. 
Results—From the crypt base, an ascending gradient of expression and activity of urokinase was associated with the epithelial cells. Median mucosal urokinase activities in each of the dietary groups of rats correlated positively with autologous median number of metaphase arrests per crypt (r=0.68; p<0.005) and per 100 crypt cells (r=0.75; p<0.001), but not with crypt column height. 
Conclusions—Localisation of an enzyme capable of leading to digestion of cell substratum in the region where cells are loosely attached to their basement membrane, and the association of its activity with indexes of cell turnover, suggest a role for urokinase in facilitating epithelial cell loss in the intestine. 

 Keywords: urokinase; intestinal epithelium; colon; epithelial proliferation PMID:9824347

Genotoxicity evaluation of buprofezin, petroleum oil and profenofos in somatic and germ cells of male mice.

PubMed

Fahmy, M A; Abdalla, E F

1998-01-01

The two pest control agents, buprofezin and petroleum oil (Super Royal), were tested to evaluate their potential mutagenicity, in comparison with the organophosphorus insecticide profenofos. Chromosomal aberration analysis was used in both somatic and germ cells of male mice. Single oral treatment at three different dose levels (1/16, 1/8 and 1/4 LD50) for each insecticide induced an increase in the percentage of chromosomal aberrations in bone-marrow cells 24 h post-treatment, indicating a dose-dependent relationship. The percentage of chromosomal aberrations reached 23 +/- 0.73, 10.5 +/- 0.64 and 15 +/- 1.4 after treatment with the highest tested dose of profenofos, buprofezin and Super Royal, respectively. Such percentages did not exceed the corresponding value of the positive control, mitomycin C (29.2 +/- 0.69). The percentage of chromosomal aberrations induced by the different doses of profenofos was still highly significant even after excluding gaps. The same trend of results was noticed only at the highest tested dose of buprofezin and Super Royal. With respect to germ cells, profenofos is also a potent inducer of chromosomal aberrations in 1ry spermatocytes, giving percentages of 14 +/- 1.3 and 19 +/- 1.6 at the two higher doses of 4.25 and 8.5 mg kg(-1) body wt., respectively. Buprofezin and Super Royal had no significant effect on mouse spermatocytes at the tested concentrations. The various types of induced aberrations were examined and recorded in both somatic and germ cells. In conclusion, the present investigation indicates that the two pest control agents buprofezin and Super Royal are relatively much safer compounds than the conventional organophosphorus insecticides.

Deficient Pms2, ERCC1, Ku86, CcOI in field defects during progression to colon cancer.

PubMed

Nguyen, Huy; Loustaunau, Cristy; Facista, Alexander; Ramsey, Lois; Hassounah, Nadia; Taylor, Hilary; Krouse, Robert; Payne, Claire M; Tsikitis, V Liana; Goldschmid, Steve; Banerjee, Bhaskar; Perini, Rafael F; Bernstein, Carol

2010-07-28

In carcinogenesis, the "field defect" is recognized clinically because of the high propensity of survivors of certain cancers to develop other malignancies of the same tissue type, often in a nearby location. Such field defects have been indicated in colon cancer. The molecular abnormalities that are responsible for a field defect in the colon should be detectable at high frequency in the histologically normal tissue surrounding a colonic adenocarcinoma or surrounding an adenoma with advanced neoplasia (well on the way to a colon cancer), but at low frequency in the colonic mucosa from patients without colonic neoplasia. Using immunohistochemistry, entire crypts within 10 cm on each side of colonic adenocarcinomas or advanced colonic neoplasias were found to be frequently reduced or absent in expression for two DNA repair proteins, Pms2 and/or ERCC1. Pms2 is a dual role protein, active in DNA mismatch repair as well as needed in apoptosis of cells with excess DNA damage. ERCC1 is active in DNA nucleotide excision repair. The reduced or absent expression of both ERCC1 and Pms2 would create cells with both increased ability to survive (apoptosis resistance) and increased level of mutability. The reduced or absent expression of both ERCC1 and Pms2 is likely an early step in progression to colon cancer. DNA repair gene Ku86 (active in DNA non-homologous end joining) and Cytochrome c Oxidase Subunit I (involved in apoptosis) had each been reported to be decreased in expression in mucosal areas close to colon cancers. However, immunohistochemical evaluation of their levels of expression showed only low to modest frequencies of crypts to be deficient in their expression in a field defect surrounding colon cancer or surrounding advanced colonic neoplasia. We show, here, our method of evaluation of crypts for expression of ERCC1, Pms2, Ku86 and CcOI. We show that frequency of entire crypts deficient for Pms2 and ERCC1 is often as great as 70% to 95% in 20 cm long areas surrounding a colonic neoplasia, while frequency of crypts deficient in Ku86 has a median value of 2% and frequency of crypts deficient in CcOI has a median value of 16% in these areas. The entire colon is 150 cm long (about 5 feet) and has about 10 million crypts in its mucosal layer. The defect in Pms2 and ERCC1 surrounding a colon cancer thus may include 1 million crypts. It is from a defective crypt that colon cancer arises.

Effects of Two Traditional Chinese Cooking Oils, Canola and Pork, on pH and Cholic Acid Content of Faeces and Colon Tumorigenesis in Kunming Mice.

PubMed

He, Xiao-Qiong; Duan, Jia-Li; Zhou, Jin; Song, Zhong-Yu; Cichello, Simon Angelo

2015-01-01

Faecal pH and cholate are two important factors that can affect colon tumorigenesis, and can be modified by diet. In this study, the effects of two Chinese traditional cooking oils (pork oil and canola/rapeseed oil) on the pH and the cholic acid content in feces, in addition to colon tumorigenesis, were studied in mice. Kunming mice were randomized into various groups; negative control group (NCG), azoxymethane control group (ACG), pork oil group (POG), and canola oil Ggroup (COG). Mice in the ACG were fed a basic rodent chow; mice in POG and COG were given 10% cooking oil rodent chow with the respective oil type. All mice were given four weekly AOM (azoxymethane) i.p. injections (10 mg/kg). The pH and cholic acid of the feces were examined every two weeks. Colon tumors, aberrant crypt foci and organ weights were examined 32 weeks following the final AOM injection. The results showed that canola oil significantly decreased faecal pH in female mice (P<0.05), but had no influence on feces pH in male mice (P>0.05). Pork oil significantly increased the feces pH in both male and female mice (P<0.05). No significant change was found in feces cholic acid content when mice were fed 10% pork oil or canola oil compared with the ACG. Although Kunming mice were not susceptible to AOM-induced tumorigenesis in terms of colon tumor incidence, pork oil significantly increased the ACF number in male mice. Canola oil showed no influence on ACF in either male or female mice. Our results indicate that cooking oil effects faecal pH, but does not affect the faecal cholic acid content and thus AOM-induced colon neoplastic ACF is modified by dietary fat.

Methanolic extract of white asparagus shoots activates TRAIL apoptotic death pathway in human cancer cells and inhibits colon carcinogenesis in a preclinical model

PubMed Central

BOUSSEROUEL, SOUAD; LE GRANDOIS, JULIE; GOSSÉ, FRANCINE; WERNER, DALAL; BARTH, STEPHAN W.; MARCHIONI, ERIC; MARESCAUX, JACQUES; RAUL, FRANCIS

2013-01-01

Shoots of white asparagus are a popular vegetable dish, known to be rich in many bioactive phytochemicals reported to possess antioxidant, and anti-inflammatory and antitumor activities. We evaluated the anticancer mechanisms of a methanolic extract of Asparagus officinalis L. shoots (Asp) on human colon carcinoma cells (SW480) and their derived metastatic cells (SW620), and Asp chemopreventive properties were also assessed in a model of colon carcinogenesis. SW480 and SW620 cell proliferation was inhibited by 80% after exposure to Asp (80 μg/ml). We demonstrated that Asp induced cell death through the activation of TRAIL DR4/DR5 death receptors leading to the activation of caspase-8 and caspase-3 and to cell apoptosis. By specific blocking agents of DR4/DR5 receptors we were able to prevent Asp-triggered cell death confirming the key role of DR4/DR5 receptors. We found also that Asp (80 μg/ml) was able to potentiate the effects of the cytokine TRAIL on cell death even in the TRAIL-resistant metastatic SW620 cells. Colon carcinogenesis was initiated in Wistar rats by intraperitoneal injections of azoxymethane (AOM), once a week for two weeks. One week after (post-initiation) rats received daily Asp (0.01%, 14 mg/kg body weight) in drinking water. After 7 weeks of Asp-treatment the colon of rats exhibited a 50% reduction of the number of preneoplastic lesions (aberrant crypt foci). In addition Asp induced inhibition of several pro-inflammatory mediators, in association with an increased expression of host-defense mediators. In the colonic mucosa of Asp-treated rats we also confirmed the pro-apoptotic effects observed in vitro including the activation of the TRAIL death-receptor signaling pathway. Taken together, our data highlight the chemopreventive effects of Asp on colon carcinogenesis and its ability to promote normal cellular homeostasis. PMID:23754197

Whey proteins protect more than red meat against azoxymethane induced ACF in Wistar rats.

PubMed

Belobrajdic, D P; McIntosh, G H; Owens, J A

2003-07-30

Protein type and density have been shown to influence colon cancer risk using a carcinogen-induced rat model. It is suggested that red meat may promote colon cancer risk more than whey proteins. The aim of this study was to evaluate the influence of red meat, whey protein and their density in the diet on the number of aberrant crypt foci (ACF), preneoplastic markers in Wistar rats. The sources of protein, red meat as barbecued kangaroo muscle meat, and whey protein concentrate were fed to rats to provide 8, 16 and 32% protein by weight in a modified AIN-93 diet with low fiber, low calcium and high polyunsaturated fat. Adult Wistar rats (13 weeks of age) were fed these diets for 4 weeks and then two s.c. injections of azoxymethane, 15 mg/kg BW, were administered 1 week apart. Diets were fed for a further 8 weeks, rats were then killed, their colons fixed in formalin saline and stained with methylene blue to quantify ACF number. Fecal samples were collected and the fecal water was isolated for quantification of heme and thiobarbituric acid reactive substances. Increasing red meat density correlated positively, while increasing dairy protein density correlated negatively with rate of weight gain (p<0.05). Dietary intake was not significantly affected by protein type or density. The 32% whey protein group had significantly less ACF in the proximal colon in comparison to the 16 and 32% red meat groups (p<0.05). This reduction in ACF number in the whey protein group may be caused by hormones associated with the reduction in weight gain, and/or by components of whey protein concentrate such as cysteine, lactose and conjugated linoleic acid which have been shown to have anti-cancer effects. Using ACF number as an index, whey protein appeared to be more protective than red meat.

Genomic Instability and Radiation Risk in Molecular Pathways to Colon Cancer

PubMed Central

Kaiser, Jan Christian; Meckbach, Reinhard; Jacob, Peter

2014-01-01

Colon cancer is caused by multiple genomic alterations which lead to genomic instability (GI). GI appears in molecular pathways of microsatellite instability (MSI) and chromosomal instability (CIN) with clinically observed case shares of about 15–20% and 80–85%. Radiation enhances the colon cancer risk by inducing GI, but little is known about different outcomes for MSI and CIN. Computer-based modelling can facilitate the understanding of the phenomena named above. Comprehensive biological models, which combine the two main molecular pathways to colon cancer, are fitted to incidence data of Japanese a-bomb survivors. The preferred model is selected according to statistical criteria and biological plausibility. Imprints of cell-based processes in the succession from adenoma to carcinoma are identified by the model from age dependences and secular trends of the incidence data. Model parameters show remarkable compliance with mutation rates and growth rates for adenoma, which has been reported over the last fifteen years. Model results suggest that CIN begins during fission of intestinal crypts. Chromosomal aberrations are generated at a markedly elevated rate which favors the accelerated growth of premalignant adenoma. Possibly driven by a trend of Westernization in the Japanese diet, incidence rates for the CIN pathway increased notably in subsequent birth cohorts, whereas rates pertaining to MSI remained constant. An imbalance between number of CIN and MSI cases began to emerge in the 1980s, whereas in previous decades the number of cases was almost equal. The CIN pathway exhibits a strong radio-sensitivity, probably more intensive in men. Among young birth cohorts of both sexes the excess absolute radiation risk related to CIN is larger by an order of magnitude compared to the MSI-related risk. Observance of pathway-specific risks improves the determination of the probability of causation for radiation-induced colon cancer in individual patients, if their exposure histories are known. PMID:25356998

Preterm infant gut microbiota affects intestinal epithelial development in a humanized microbiome gnotobiotic mouse model.

PubMed

Yu, Yueyue; Lu, Lei; Sun, Jun; Petrof, Elaine O; Claud, Erika C

2016-09-01

Development of the infant small intestine is influenced by bacterial colonization. To promote establishment of optimal microbial communities in preterm infants, knowledge of the beneficial functions of the early gut microbiota on intestinal development is needed. The purpose of this study was to investigate the impact of early preterm infant microbiota on host gut development using a gnotobiotic mouse model. Histological assessment of intestinal development was performed. The differentiation of four epithelial cell lineages (enterocytes, goblet cells, Paneth cells, enteroendocrine cells) and tight junction (TJ) formation was examined. Using weight gain as a surrogate marker for health, we found that early microbiota from a preterm infant with normal weight gain (MPI-H) induced increased villus height and crypt depth, increased cell proliferation, increased numbers of goblet cells and Paneth cells, and enhanced TJs compared with the changes induced by early microbiota from a poor weight gain preterm infant (MPI-L). Laser capture microdissection (LCM) plus qRT-PCR further revealed, in MPI-H mice, a higher expression of stem cell marker Lgr5 and Paneth cell markers Lyz1 and Cryptdin5 in crypt populations, along with higher expression of the goblet cell and mature enterocyte marker Muc3 in villus populations. In contrast, MPI-L microbiota failed to induce the aforementioned changes and presented intestinal characteristics comparable to a germ-free host. Our data demonstrate that microbial communities have differential effects on intestinal development. Future studies to identify pioneer settlers in neonatal microbial communities necessary to induce maturation may provide new insights for preterm infant microbial ecosystem therapeutics. Copyright © 2016 the American Physiological Society.

Radioprotective potential of histamine on rat small intestine and uterus

PubMed Central

Carabajal, E.; Massari, N.; Croci, M.; Martinel Lamas, D.; Prestifilippo, J.P.; Ciraolo, P.; Bergoc, R.M.; Rivera, E.S.; Medina, V.A.

2012-01-01

The aim of this study was to improve knowledge about histamine radioprotective potential investigating its effect on reducing ionising radiation-induced injury and genotoxic damage on the rat small intestine and uterus. Forty 10-week-old male and 40 female Sprague-Dawley rats were divided into 4 groups. Histamine and histamine-5Gy groups received a daily subcutaneous histamine injection (0.1 mg/kg) starting 24 h before irradiation. Histamine-5Gy and untreated-5Gy groups were irradiated with a dose of whole-body Cesium-137 irradiation. Three days after irradiation animals were sacrificed and tissues were removed, fixed, and stained with haematoxylin and eosin, and histological characteristics were evaluated. Proliferation, apoptosis and oxidative DNA markers were studied by immunohistochemistry, while micronucleus assay was performed to evaluate chromosomal damage. Histamine treatment reduced radiation-induced mucosal atrophy, oedema and vascular damage produced by ionising radiation, increasing the number of crypts per circumference (239±12 vs 160±10; P<0.01). This effect was associated with a reduction of radiation-induced intestinal crypts apoptosis. Additionally, histamine decreased the frequency of micronuclei formation and also significantly attenuated 8-OHdG immunoreactivity, a marker of DNA oxidative damage. Furthermore, radiation induced flattening of the endometrial surface, depletion of deep glands and reduced mitosis, effects that were completely blocked by histamine treatment. The expression of a proliferation marker in uterine luminal and glandular cells was markedly stimulated in histamine treated and irradiated rats. The obtained evidences indicate that histamine is a potential candidate as a safe radio-protective agent that might increase the therapeutic index of radiotherapy for intra-abdominal and pelvic cancers. However, its efficacy needs to be carefully investigated in prospective clinical trials. PMID:23361244

Model-Based Phenotypic Signatures Governing the Dynamics of the Stem and Semi-differentiated Cell Populations in Dysplastic Colonic Crypts.

PubMed

Nikolov, Svetoslav; Santos, Guido; Wolkenhauer, Olaf; Vera, Julio

2018-02-01

Mathematical modeling of cell differentiated in colonic crypts can contribute to a better understanding of basic mechanisms underlying colonic tissue organization, but also its deregulation during carcinogenesis and tumor progression. Here, we combined bifurcation analysis to assess the effect that time delay has in the complex interplay of stem cells and semi-differentiated cells at the niche of colonic crypts, and systematic model perturbation and simulation to find model-based phenotypes linked to cancer progression. The models suggest that stem cell and semi-differentiated cell population dynamics in colonic crypts can display chaotic behavior. In addition, we found that clinical profiling of colorectal cancer correlates with the in silico phenotypes proposed by the mathematical model. Further, potential therapeutic targets for chemotherapy resistant phenotypes are proposed, which in any case will require experimental validation.

The use of WaveLight® Contoura to create a uniform cornea: the LYRA Protocol. Part 1: the effect of higher-order corneal aberrations on refractive astigmatism

PubMed Central

Motwani, Manoj

2017-01-01

Purpose To demonstrate how higher-order corneal aberrations can cancel out, modify, or induce lower-order corneal astigmatism. Patients and methods Six representative eyes are presented that show different scenarios in which higher-order aberrations interacting with corneal astigmatism can affect the manifest refraction. WaveLight® Contoura ablation maps showing the higher-order aberrations are shown, as are results of correction with full measured correction using the LYRA (Layer Yolked Reduction of Astigmatism) Protocol. Results Higher-order corneal aberrations such as trefoil, quadrafoil, and coma can create ovalization of the central cornea, which can interact with the ovalization caused by lower-order astigmatism to either induce, cancel out, or modify the manifest refraction. Contoura processing successfully determines the linkage of these interactions resulting in full astigmatism removal. Purely lenticular astigmatism appears to be rare, but a case is also demonstrated. The author theorizes that all aberrations require cerebral compensatory processing and can be removed, supported by the facts that full removal of aberrations and its linkage with lower-order astigmatism with the LYRA Protocol has not resulted in worse or unacceptable vision for any patients. Conclusion Higher-order aberrations interacting with lower-order astigmatism is the main reason for the differences between manifest refraction and Contoura measured astigmatism, and the linkage between these interactions can be successfully treated using Contoura and the LYRA Protocol. Lenticular astigmatism is relatively rare. PMID:28553069

The use of WaveLight® Contoura to create a uniform cornea: the LYRA Protocol. Part 1: the effect of higher-order corneal aberrations on refractive astigmatism.

PubMed

Motwani, Manoj

2017-01-01

To demonstrate how higher-order corneal aberrations can cancel out, modify, or induce lower-order corneal astigmatism. Six representative eyes are presented that show different scenarios in which higher-order aberrations interacting with corneal astigmatism can affect the manifest refraction. WaveLight ® Contoura ablation maps showing the higher-order aberrations are shown, as are results of correction with full measured correction using the LYRA (Layer Yolked Reduction of Astigmatism) Protocol. Higher-order corneal aberrations such as trefoil, quadrafoil, and coma can create ovalization of the central cornea, which can interact with the ovalization caused by lower-order astigmatism to either induce, cancel out, or modify the manifest refraction. Contoura processing successfully determines the linkage of these interactions resulting in full astigmatism removal. Purely lenticular astigmatism appears to be rare, but a case is also demonstrated. The author theorizes that all aberrations require cerebral compensatory processing and can be removed, supported by the facts that full removal of aberrations and its linkage with lower-order astigmatism with the LYRA Protocol has not resulted in worse or unacceptable vision for any patients. Higher-order aberrations interacting with lower-order astigmatism is the main reason for the differences between manifest refraction and Contoura measured astigmatism, and the linkage between these interactions can be successfully treated using Contoura and the LYRA Protocol. Lenticular astigmatism is relatively rare.

An animal model of panic vulnerability with chronic disinhibition of the dorsomedial/perifornical hypothalamus

PubMed Central

Johnson, Philip L.; Shekhar, Anantha

2013-01-01

Panic disorder (PD) is a severe anxiety disorder characterized by susceptibility to induction of panic attacks by subthreshold interoceptive stimuli such as sodium lactate infusions or hypercapnia induction. Here we review a model of panic vulnerability in rats involving chronic inhibition of GABAergic tone in the dorsomedial/ perifornical hypothalamic (DMH/PeF) region that produces enhanced anxiety and freezing responses in fearful situations, as well as a vulnerability to displaying acute panic-like increases in cardioexcitation, respiration activity and “flight” associated behavior following subthreshold interoceptive stimuli that do not elicit panic responses in control rats. This model of panic vulnerability was developed over 15 years ago and has provided an excellent preclinical model with robust face, predictive and construct validity. The model recapitulates many of the phenotypics features of panic attacks associated with human panic disorder (face validity) including greater sensitivity to panicogenic stimuli demonstrated by sudden onset of anxiety and autonomic activation following an administration of a sub-threshold (i.e., do not usually induce panic in healthy subjects) stimulus such as sodium lactate, CO2, or yohimbine. The construct validity is supported by several key findings; DMH/PeF neurons regulate behavioral and autonomic components of a normal adaptive panic response, as well as being implicated in eliciting panic-like responses in humans. Additionally, Patients with PD have deficits in central GABA activity and pharmacological restoration of central GABA activity prevents panic attacks, consistent with this model. The model’s predictive validity is demonstrated by not only showing panic responses to several panic-inducing agents that elicit panic in patients with PD, but also by the positive therapeutic responses to clinically used agents such as alprazolam and antidepressants that attenuate panic attacks in patients. More importantly, this model has been utilized to discover novel drugs such as group II metabotropic glutamate agonists and a new class of translocator protein enhancers of GABA, both of which subsequently showed anti-panic properties in clinical trials. All of these data suggest that this preparation provides a strong preclinical model of some forms of human panic disorders. PMID:22484112

A dose error evaluation study for 4D dose calculations

NASA Astrophysics Data System (ADS)

Milz, Stefan; Wilkens, Jan J.; Ullrich, Wolfgang

2014-10-01

Previous studies have shown that respiration induced motion is not negligible for Stereotactic Body Radiation Therapy. The intrafractional breathing induced motion influences the delivered dose distribution on the underlying patient geometry such as the lung or the abdomen. If a static geometry is used, a planning process for these indications does not represent the entire dynamic process. The quality of a full 4D dose calculation approach depends on the dose coordinate transformation process between deformable geometries. This article provides an evaluation study that introduces an advanced method to verify the quality of numerical dose transformation generated by four different algorithms. The used transformation metric value is based on the deviation of the dose mass histogram (DMH) and the mean dose throughout dose transformation. The study compares the results of four algorithms. In general, two elementary approaches are used: dose mapping and energy transformation. Dose interpolation (DIM) and an advanced concept, so called divergent dose mapping model (dDMM), are used for dose mapping. The algorithms are compared to the basic energy transformation model (bETM) and the energy mass congruent mapping (EMCM). For evaluation 900 small sample regions of interest (ROI) are generated inside an exemplary lung geometry (4DCT). A homogeneous fluence distribution is assumed for dose calculation inside the ROIs. The dose transformations are performed with the four different algorithms. The study investigates the DMH-metric and the mean dose metric for different scenarios (voxel sizes: 8 mm, 4 mm, 2 mm, 1 mm 9 different breathing phases). dDMM achieves the best transformation accuracy in all measured test cases with 3-5% lower errors than the other models. The results of dDMM are reasonable and most efficient in this study, although the model is simple and easy to implement. The EMCM model also achieved suitable results, but the approach requires a more complex programming structure. The study discloses disadvantages for the bETM and for the DIM. DIM yielded insufficient results for large voxel sizes, while bETM is prone to errors for small voxel sizes.

A dose error evaluation study for 4D dose calculations.

PubMed

Milz, Stefan; Wilkens, Jan J; Ullrich, Wolfgang

2014-11-07

Previous studies have shown that respiration induced motion is not negligible for Stereotactic Body Radiation Therapy. The intrafractional breathing induced motion influences the delivered dose distribution on the underlying patient geometry such as the lung or the abdomen. If a static geometry is used, a planning process for these indications does not represent the entire dynamic process. The quality of a full 4D dose calculation approach depends on the dose coordinate transformation process between deformable geometries. This article provides an evaluation study that introduces an advanced method to verify the quality of numerical dose transformation generated by four different algorithms.The used transformation metric value is based on the deviation of the dose mass histogram (DMH) and the mean dose throughout dose transformation. The study compares the results of four algorithms. In general, two elementary approaches are used: dose mapping and energy transformation. Dose interpolation (DIM) and an advanced concept, so called divergent dose mapping model (dDMM), are used for dose mapping. The algorithms are compared to the basic energy transformation model (bETM) and the energy mass congruent mapping (EMCM). For evaluation 900 small sample regions of interest (ROI) are generated inside an exemplary lung geometry (4DCT). A homogeneous fluence distribution is assumed for dose calculation inside the ROIs. The dose transformations are performed with the four different algorithms.The study investigates the DMH-metric and the mean dose metric for different scenarios (voxel sizes: 8 mm, 4 mm, 2 mm, 1 mm; 9 different breathing phases). dDMM achieves the best transformation accuracy in all measured test cases with 3-5% lower errors than the other models. The results of dDMM are reasonable and most efficient in this study, although the model is simple and easy to implement. The EMCM model also achieved suitable results, but the approach requires a more complex programming structure. The study discloses disadvantages for the bETM and for the DIM. DIM yielded insufficient results for large voxel sizes, while bETM is prone to errors for small voxel sizes.

Protection of Radiation-Induced Damage to the Hematopoietic System, Small Intestine and Salivary Glands in Rats by JNJ7777120 Compound, a Histamine H4 Ligand

PubMed Central

Martinel Lamas, Diego J.; Carabajal, Eliana; Prestifilippo, Juan P.; Rossi, Luis; Elverdin, Juan C.; Merani, Susana; Bergoc, Rosa M.; Rivera, Elena S.; Medina, Vanina A.

2013-01-01

Based on previous data on the histamine radioprotective effect on highly radiosensitive tissues, in the present work we aimed at investigating the radioprotective potential of the H4R ligand, JNJ7777120, on ionizing radiation-induced injury and genotoxic damage in small intestine, salivary glands and hematopoietic tissue. For that purpose, rats were divided into 4 groups. JNJ7777120 and JNJ7777120-irradiated groups received a daily subcutaneous JNJ7777120 injection (10 mg/kg) starting 24 h before irradiation. Irradiated groups received a single dose of 5 Gy on whole-body using Cesium-137 source and were sacrificed 3 or 30 days after irradiation. Tissues were removed, fixed, stained with hematoxylin and eosin or PAS staining and histological characteristics were evaluated. Proliferative and apoptotic markers were studied by immunohistochemistry, while micronucleus assay was performed to evaluate DNA damage. Submandibular gland (SMG) function was evaluated by methacholine-induced salivation. Results indicate that JNJ7777120 treatment diminished mucosal atrophy and preserved villi and the number of crypts after radiation exposure (240±8 vs. 165±10, P<0.01). This effect was associated to a reduced apoptosis and DNA damage in intestinal crypts. JNJ7777120 reduced radiation-induced aplasia, preserving medullar components and reducing formation of micronucleus and also it accelerated bone marrow repopulation. Furthermore, it reduced micronucleus frequency in peripheral blood (27±8 vs. 149±22, in 1,000 erythrocytes, P<0.01). JNJ7777120 completely reversed radiation-induced reduced salivation, conserving glandular mass with normal histological appearance and reducing apoptosis and atrophy of SMG. JNJ7777120 exhibits radioprotective effects against radiation-induced cytotoxic and genotoxic damages in small intestine, SMG and hematopoietic tissues and, thus, could be of clinical value for patients undergoing radiotherapy. PMID:23922686

Impact of Primary Spherical Aberration, Spatial Frequency and Stiles Crawford Apodization on Wavefront determined Refractive Error: A Computational Study

PubMed Central

Xu, Renfeng; Bradley, Arthur; Thibos, Larry N.

2013-01-01

Purpose We tested the hypothesis that pupil apodization is the basis for central pupil bias of spherical refractions in eyes with spherical aberration. Methods We employed Fourier computational optics in which we vary spherical aberration levels, pupil size, and pupil apodization (Stiles Crawford Effect) within the pupil function, from which point spread functions and optical transfer functions were computed. Through-focus analysis determined the refractive correction that optimized retinal image quality. Results For a large pupil (7 mm), as spherical aberration levels increase, refractions that optimize the visual Strehl ratio mirror refractions that maximize high spatial frequency modulation in the image and both focus a near paraxial region of the pupil. These refractions are not affected by Stiles Crawford Effect apodization. Refractions that optimize low spatial frequency modulation come close to minimizing wavefront RMS, and vary with level of spherical aberration and Stiles Crawford Effect. In the presence of significant levels of spherical aberration (e.g. C40 = 0.4 µm, 7mm pupil), low spatial frequency refractions can induce −0.7D myopic shift compared to high SF refraction, and refractions that maximize image contrast of a 3 cycle per degree square-wave grating can cause −0.75D myopic drift relative to refractions that maximize image sharpness. Discussion Because of small depth of focus associated with high spatial frequency stimuli, the large change in dioptric power across the pupil caused by spherical aberration limits the effective aperture contributing to the image of high spatial frequencies. Thus, when imaging high spatial frequencies, spherical aberration effectively induces an annular aperture defining that portion of the pupil contributing to a well-focused image. As spherical focus is manipulated during the refraction procedure, the dimensions of the annular aperture change. Image quality is maximized when the inner radius of the induced annulus falls to zero, thus defining a circular near paraxial region of the pupil that determines refraction outcome. PMID:23683093

A correction method for the axial maladjustment of transmission-type optical system based on aberration theory

NASA Astrophysics Data System (ADS)

Xu, Chunmei; Huang, Fu-yu; Yin, Jian-ling; Chen, Yu-dan; Mao, Shao-juan

2016-10-01

The influence of aberration on misalignment of optical system is considered fully, the deficiencies of Gauss optical correction method is pointed, and a correction method for transmission-type misalignment optical system is proposed based on aberration theory. The variation regularity of single lens aberration caused by axial displacement is analyzed, and the aberration effect is defined. On this basis, through calculating the size of lens adjustment induced by the image position error and the magnifying rate error, the misalignment correction formula based on the constraints of the aberration is deduced mathematically. Taking the three lens collimation system for an example, the test is carried out to validate this method, and its superiority is proved.

Inducible Intestine-specific Deletion Of Krüppel-Like Factor 5 Is Characterized By A Regenerative Response In Adult Mouse Colon

PubMed Central

Nandan, Mandayam O.; Ghaleb, Amr M.; Liu, Yang; Bialkowska, Agnieszka B.; McConnell, Beth B.; Shroyer, Kenneth R.; Robine, Sylvie

2014-01-01

Krüppel-like factor 5 (KLF5) is a pro-proliferative transcriptional regulator primarily expressed in the intestinal crypt epithelial cells. Constitutive intestine-specific deletion of Klf5 is neonatal lethal suggesting a crucial role for KLF5 in intestinal development and homeostasis. We have previously shown Klf5 to play an active role regulating intestinal tumorigenesis. Here we examine the effect of inducible intestine-specific deletion of Klf5 in adult mice. Klf5 is lost from the intestine beginning at day 3 after the start of a 5-day treatment with the inducer tamoxifen. Although the mice have no significant weight loss or lethality, the colonic tissue shows signs of epithelial distress starting at day 3 following induction. Accompanying the morphological changes is a significant loss of proliferative crypt epithelial cells as revealed by BrdU or Ki67 staining at days 3 & 5 after start of tamoxifen. We also observed a loss of goblet cells from the colon and Paneth cells from the small intestine upon induced deletion of Klf5. In addition, loss of Klf5 from the colonic epithelium is accompanied by a regenerative response that coincides with an expansion in the zone of Sox9 expression along the crypt axis. At day 11, both proliferation and Sox9 expression return to baseline levels. Microarray and quantitative PCR analyses reveal an upregulation of several regeneration-associated genes (Reg1A, Reg3G and Reg3B) and down-regulation of many Klf5 targets (Ki-67, cyclin B, Cdc2 and cyclin D1). Sox9 and Reg1A protein levels are also increased upon Klf5 loss. Lentiviral-mediated knockdown of KLF5 and exogenous expression of KLF5 in colorectal cancer cell lines confirm that Sox9 expression is negatively regulated by KLF5. Furthermore, ChIP assays reveal a direct association of KLF5 with both the Sox9 and Reg1A promoters. We have shown that disruption of epithelial homeostasis due to Klf5 loss from the adult colon is followed by a regenerative response led by Sox9 and the Reg family of proteins. Our study demonstrates that adult mouse colonic tissue undergoes acute physiological changes to accommodate the loss of Klf5 withstanding epithelial damage further signifying importance of Klf5 in colonic homeostasis. PMID:24440658

Evaluation of chromosomal aberrations induced by 188Re-dendrimer nanosystem on B16f1 melanoma cells.

PubMed

Tassano, Marcos; Oddone, Natalia; Fernández, Marcelo; Porcal, Williams; García, María Fernanda; Martínez-López, Wilner; Benech, Juan Claudio; Cabral, Pablo

2018-06-19

To study the rhenium-188 labeling of polyamidoamine (PAMAM) generation 4 (G4) dendrimer and its evaluation on biodistribution and chromosomal aberrations in melanoma cells induced by ionizing radiation as potential treatment agent. Dendrimers were first conjugated with Suc-HYNIC (succinimidyl 6-hydrazinopyridine-3-carboxylic acid hydrochloride). Dendrimer-HYNIC was then incubated with 188 ReO 4 - . Biodistribution was performed administrating 188 Re-dendrimer to normal (NM) or melanoma-bearing mice (MBM). Chromosome aberration test was conducted in order to measure treatment capacity of 188 Re-dendrimer in melanoma cells. Radiolabeling yield of dendrimer was approx. 70%. Biodistribution studies in NM showed blood clearance with hepatic and renal depuration. MBM showed a similar pattern of biodistribution with tumor uptake of 6% of injected dose. Aberrant metaphases quantified in control cells were 7%, increasing to 29.5% in cells treated with 15μCi (0.555 MBq) of 188 Re-dendrimer for 24 h. 188 Re-dendrimer can produce double-stranded breaks in DNA induced by ionizing radiation in melanoma cells in vitro.

γδ T-cell-deficient mice show alterations in mucin expression, glycosylation, and goblet cells but maintain an intact mucus layer

PubMed Central

Kober, Olivia I.; Ahl, David; Pin, Carmen; Holm, Lena; Carding, Simon R.

2014-01-01

Intestinal homeostasis is maintained by a hierarchy of immune defenses acting in concert to minimize contact between luminal microorganisms and the intestinal epithelial cell surface. The intestinal mucus layer, covering the gastrointestinal tract epithelial cells, contributes to mucosal homeostasis by limiting bacterial invasion. In this study, we used γδ T-cell-deficient (TCRδ−/−) mice to examine whether and how γδ T-cells modulate the properties of the intestinal mucus layer. Increased susceptibility of TCRδ−/− mice to dextran sodium sulfate (DSS)-induced colitis is associated with a reduced number of goblet cells. Alterations in the number of goblet cells and crypt lengths were observed in the small intestine and colon of TCRδ−/− mice compared with C57BL/6 wild-type (WT) mice. Addition of keratinocyte growth factor to small intestinal organoid cultures from TCRδ−/− mice showed a marked increase in crypt growth and in both goblet cell number and redistribution along the crypts. There was no apparent difference in the thickness or organization of the mucus layer between TCRδ−/− and WT mice, as measured in vivo. However, γδ T-cell deficiency led to reduced sialylated mucins in association with increased gene expression of gel-secreting Muc2 and membrane-bound mucins, including Muc13 and Muc17. Collectively, these data provide evidence that γδ T cells play an important role in the maintenance of mucosal homeostasis by regulating mucin expression and promoting goblet cell function in the small intestine. PMID:24503767

γδ T-cell-deficient mice show alterations in mucin expression, glycosylation, and goblet cells but maintain an intact mucus layer.

PubMed

Kober, Olivia I; Ahl, David; Pin, Carmen; Holm, Lena; Carding, Simon R; Juge, Nathalie

2014-04-01

Intestinal homeostasis is maintained by a hierarchy of immune defenses acting in concert to minimize contact between luminal microorganisms and the intestinal epithelial cell surface. The intestinal mucus layer, covering the gastrointestinal tract epithelial cells, contributes to mucosal homeostasis by limiting bacterial invasion. In this study, we used γδ T-cell-deficient (TCRδ(-/-)) mice to examine whether and how γδ T-cells modulate the properties of the intestinal mucus layer. Increased susceptibility of TCRδ(-/-) mice to dextran sodium sulfate (DSS)-induced colitis is associated with a reduced number of goblet cells. Alterations in the number of goblet cells and crypt lengths were observed in the small intestine and colon of TCRδ(-/-) mice compared with C57BL/6 wild-type (WT) mice. Addition of keratinocyte growth factor to small intestinal organoid cultures from TCRδ(-/-) mice showed a marked increase in crypt growth and in both goblet cell number and redistribution along the crypts. There was no apparent difference in the thickness or organization of the mucus layer between TCRδ(-/-) and WT mice, as measured in vivo. However, γδ T-cell deficiency led to reduced sialylated mucins in association with increased gene expression of gel-secreting Muc2 and membrane-bound mucins, including Muc13 and Muc17. Collectively, these data provide evidence that γδ T cells play an important role in the maintenance of mucosal homeostasis by regulating mucin expression and promoting goblet cell function in the small intestine.

A microengineered collagen scaffold for generating a polarized crypt-villus architecture of human small intestinal epithelium.

PubMed

Wang, Yuli; Gunasekara, Dulan B; Reed, Mark I; DiSalvo, Matthew; Bultman, Scott J; Sims, Christopher E; Magness, Scott T; Allbritton, Nancy L

2017-06-01

The human small intestinal epithelium possesses a distinct crypt-villus architecture and tissue polarity in which proliferative cells reside inside crypts while differentiated cells are localized to the villi. Indirect evidence has shown that the processes of differentiation and migration are driven in part by biochemical gradients of factors that specify the polarity of these cellular compartments; however, direct evidence for gradient-driven patterning of this in vivo architecture has been hampered by limitations of the in vitro systems available. Enteroid cultures are a powerful in vitro system; nevertheless, these spheroidal structures fail to replicate the architecture and lineage compartmentalization found in vivo, and are not easily subjected to gradients of growth factors. In the current work, we report the development of a micropatterned collagen scaffold with suitable extracellular matrix and stiffness to generate an in vitro self-renewing human small intestinal epithelium that replicates key features of the in vivo small intestine: a crypt-villus architecture with appropriate cell-lineage compartmentalization and an open and accessible luminal surface. Chemical gradients applied to the crypt-villus axis promoted the creation of a stem/progenitor-cell zone and supported cell migration along the crypt-villus axis. This new approach combining microengineered scaffolds, biophysical cues and chemical gradients to control the intestinal epithelium ex vivo can serve as a physiologically relevant mimic of the human small intestinal epithelium, and is broadly applicable to model other tissues that rely on gradients for physiological function. Copyright © 2017 Elsevier Ltd. All rights reserved.

Lineage tracing reveals multipotent stem cells maintain human adenomas and the pattern of clonal expansion in tumor evolution

PubMed Central

Humphries, Adam; Cereser, Biancastella; Gay, Laura J.; Miller, Daniel S. J.; Das, Bibek; Gutteridge, Alice; Elia, George; Nye, Emma; Jeffery, Rosemary; Poulsom, Richard; Novelli, Marco R.; Rodriguez-Justo, Manuel; McDonald, Stuart A. C.; Wright, Nicholas A.; Graham, Trevor A.

2013-01-01

The genetic and morphological development of colorectal cancer is a paradigm for tumorigenesis. However, the dynamics of clonal evolution underpinning carcinogenesis remain poorly understood. Here we identify multipotential stem cells within human colorectal adenomas and use methylation patterns of nonexpressed genes to characterize clonal evolution. Numerous individual crypts from six colonic adenomas and a hyperplastic polyp were microdissected and characterized for genetic lesions. Clones deficient in cytochrome c oxidase (CCO−) were identified by histochemical staining followed by mtDNA sequencing. Topographical maps of clone locations were constructed using a combination of these data. Multilineage differentiation within clones was demonstrated by immunofluorescence. Methylation patterns of adenomatous crypts were determined by clonal bisulphite sequencing; methylation pattern diversity was compared with a mathematical model to infer to clonal dynamics. Individual adenomatous crypts were clonal for mtDNA mutations and contained both mucin-secreting and neuroendocrine cells, demonstrating that the crypt contained a multipotent stem cell. The intracrypt methylation pattern was consistent with the crypts containing multiple competing stem cells. Adenomas were epigenetically diverse populations, suggesting that they were relatively mitotically old populations. Intratumor clones typically showed less diversity in methylation pattern than the tumor as a whole. Mathematical modeling suggested that recent clonal sweeps encompassing the whole adenoma had not occurred. Adenomatous crypts within human tumors contain actively dividing stem cells. Adenomas appeared to be relatively mitotically old populations, pocketed with occasional newly generated subclones that were the result of recent rapid clonal expansion. Relative stasis and occasional rapid subclone growth may characterize colorectal tumorigenesis. PMID:23766371

Lineage tracing reveals multipotent stem cells maintain human adenomas and the pattern of clonal expansion in tumor evolution.

PubMed

Humphries, Adam; Cereser, Biancastella; Gay, Laura J; Miller, Daniel S J; Das, Bibek; Gutteridge, Alice; Elia, George; Nye, Emma; Jeffery, Rosemary; Poulsom, Richard; Novelli, Marco R; Rodriguez-Justo, Manuel; McDonald, Stuart A C; Wright, Nicholas A; Graham, Trevor A

2013-07-02

The genetic and morphological development of colorectal cancer is a paradigm for tumorigenesis. However, the dynamics of clonal evolution underpinning carcinogenesis remain poorly understood. Here we identify multipotential stem cells within human colorectal adenomas and use methylation patterns of nonexpressed genes to characterize clonal evolution. Numerous individual crypts from six colonic adenomas and a hyperplastic polyp were microdissected and characterized for genetic lesions. Clones deficient in cytochrome c oxidase (CCO(-)) were identified by histochemical staining followed by mtDNA sequencing. Topographical maps of clone locations were constructed using a combination of these data. Multilineage differentiation within clones was demonstrated by immunofluorescence. Methylation patterns of adenomatous crypts were determined by clonal bisulphite sequencing; methylation pattern diversity was compared with a mathematical model to infer to clonal dynamics. Individual adenomatous crypts were clonal for mtDNA mutations and contained both mucin-secreting and neuroendocrine cells, demonstrating that the crypt contained a multipotent stem cell. The intracrypt methylation pattern was consistent with the crypts containing multiple competing stem cells. Adenomas were epigenetically diverse populations, suggesting that they were relatively mitotically old populations. Intratumor clones typically showed less diversity in methylation pattern than the tumor as a whole. Mathematical modeling suggested that recent clonal sweeps encompassing the whole adenoma had not occurred. Adenomatous crypts within human tumors contain actively dividing stem cells. Adenomas appeared to be relatively mitotically old populations, pocketed with occasional newly generated subclones that were the result of recent rapid clonal expansion. Relative stasis and occasional rapid subclone growth may characterize colorectal tumorigenesis.

Pharmacologic ATM but not ATR kinase inhibition abrogates p21-dependent G1 arrest and promotes gastrointestinal syndrome after total body irradiation.

PubMed

Vendetti, Frank P; Leibowitz, Brian J; Barnes, Jennifer; Schamus, Sandy; Kiesel, Brian F; Abberbock, Shira; Conrads, Thomas; Clump, David Andy; Cadogan, Elaine; O'Connor, Mark J; Yu, Jian; Beumer, Jan H; Bakkenist, Christopher J

2017-02-01

We show that ATM kinase inhibition using AZ31 prior to 9 or 9.25 Gy total body irradiation (TBI) reduced median time to moribund in mice to 8 days. ATR kinase inhibition using AZD6738 prior to TBI did not reduce median time to moribund. The striking finding associated with ATM inhibition prior to TBI was increased crypt loss within the intestine epithelium. ATM inhibition reduced upregulation of p21, an inhibitor of cyclin-dependent kinases, and blocked G1 arrest after TBI thereby increasing the number of S phase cells in crypts in wild-type but not Cdkn1a(p21 CIP/WAF1 )-/- mice. In contrast, ATR inhibition increased upregulation of p21 after TBI. Thus, ATM activity is essential for p21-dependent arrest while ATR inhibition may potentiate arrest in crypt cells after TBI. Nevertheless, ATM inhibition reduced median time to moribund in Cdkn1a(p21 CIP/WAF1 )-/- mice after TBI. ATM inhibition also increased cell death in crypts at 4 h in Cdkn1a(p21 CIP/WAF1 )-/-, earlier than at 24 h in wild-type mice after TBI. In contrast, ATR inhibition decreased cell death in crypts in Cdkn1a(p21 CIP/WAF1 )-/- mice at 4 h after TBI. We conclude that ATM activity is essential for p21-dependent and p21-independent mechanisms that radioprotect intestinal crypts and that ATM inhibition promotes GI syndrome after TBI.

Comparison of the ocular wavefront aberration between pharmacologically-induced and stimulus-driven accommodation.

PubMed

Plainis, S; Plevridi, E; Pallikaris, I G

2009-05-01

To compare the ocular wavefront aberration between pharmacologically- and stimulus-driven accommodation in phakic eyes of young subjects. The aberration structure of the tested eye when accommodating was measured using the Complete Ophthalmic Analysis System (COAS; AMO WaveFront Sciences, Albuquerque, NM, USA). It was used in conjunction with a purposely-modified Badal optometer to allow blur-driven accommodation to be stimulated by a high contrast letter E with a vergence range between +0.84 D and -8.00 D. Pharmacological accommodation was induced with one drop of pilocarpine 4%. Data from six subjects (age range: 23-36 years) with dark irides were collected. No correlation was found between the maximal levels of accommodative response achieved with an 8 D blur-driven stimulus and pharmacological stimulation. Pharmacological accommodation varied considerably among subjects: maximum accommodation, achieved within 38-85 min following application of pilocarpine, ranged from 2.7 D to 10.0 D. Furthermore, although the changes of spherical aberration and coma as a function of accommodation were indistinguishable between the two methods for low levels of response, a characteristic break in the pattern of aberration occurred at higher levels of pilocarpine-induced accommodation. This probably resulted from differences in the time course of biometric changes occurring with the two methods. Measuring the pilocarpine-induced accommodative response at only one time point after its application may lead to misleading results. The considerable inter-individual differences in the time course of drug-induced accommodative response and its magnitude may lead to overestimation or underestimation of the corresponding amplitude of normal, blur-driven accommodation. Stimulating accommodation by topical application of pilocarpine is inappropriate for evaluating the efficacy of 'accommodating' IOLs.

Small intestine histomorphometry of beef cattle with divergent feed efficiency

PubMed Central

2013-01-01

Background The provision of feed is a major cost in beef production. Therefore, the improvement of feed efficiency is warranted. The direct assessment of feed efficiency has limitations and alternatives are needed. Small intestine micro-architecture is associated with function and may be related to feed efficiency. The objective was to verify the potential histomorphological differences in the small intestine of animals with divergent feed efficiency. Methods From a population of 45 feedlot steers, 12 were selected with low-RFI (superior feed efficiency) and 12 with high-RFI (inferior feed efficiency) at the end of the finishing period. The animals were processed at 13.79 ± 1.21 months of age. Within 1.5 h of slaughter the gastrointestinal tract was collected and segments from duodenum and ileum were harvested. Tissue fragments were processed, sectioned and stained with hematoxylin and eosin. Photomicroscopy images were taken under 1000x magnification. For each animal 100 intestinal crypts were imaged, in a cross section view, from each of the two intestinal segments. Images were analyzed using the software ImageJ®. The measurements taken were: crypt area, crypt perimeter, crypt lumen area, nuclei number and the cell size was indirectly calculated. Data were analyzed using general linear model and correlation procedures of SAS®. Results Efficient beef steers (low-RFI) have a greater cellularity (indicated by nuclei number) in the small intestinal crypts, both in duodenum and ileum, than less efficient beef steers (high-RFI) (P < 0.05). The mean values for the nuclei number of the low-RFI and high-RFI groups were 33.16 and 30.30 in the duodenum and 37.21 and 33.65 in the ileum, respectively. The average size of the cells did not differ between feed efficiency groups in both segments (P ≥ 0.10). A trend was observed (P ≤ 0.10) for greater crypt area and crypt perimeter in the ileum for cattle with improved feed efficiency. Conclusion Improved feed efficiency is associated with greater cellularity and no differences on average cell size in the crypts of the small intestine in the bovine. These observations are likely to lead to an increase in the energy demand by the small intestine regardless of the more desirable feed efficiency. PMID:23379622

Expression of apical Na(+)-L-glutamine co-transport activity, B(0)-system neutral amino acid co-transporter (B(0)AT1) and angiotensin-converting enzyme 2 along the jejunal crypt-villus axis in young pigs fed a liquid formula.

PubMed

Yang, Chengbo; Yang, Xiaojian; Lackeyram, Dale; Rideout, Todd C; Wang, Zirong; Stoll, Barbara; Yin, Yulong; Burrin, Douglas G; Fan, Ming Z

2016-06-01

Gut apical amino acid (AA) transport activity is high at birth and during suckling, thus being essential to maintain luminal nutrient-dependent mucosal growth through providing AA as essential metabolic fuel, substrates and nutrient stimuli for cellular growth. Because system-B(0) Na(+)-neutral AA co-transporter (B(0)AT1, encoded by the SLC6A19 gene) plays a dominant role for apical uptake of large neutral AA including L-Gln, we hypothesized that high apical Na(+)-Gln co-transport activity, and B(0)AT1 (SLC6A19) in co-expression with angiotensin-converting enzyme 2 (ACE2) were expressed along the entire small intestinal crypt-villus axis in young animals via unique control mechanisms. Kinetics of Na(+)-Gln co-transport activity in the apical membrane vesicles, prepared from epithelial cells sequentially isolated along the jejunal crypt-villus axis from liquid formula-fed young pigs, were measured with the membrane potential being clamped to zero using thiocyanate. Apical maximal Na(+)-Gln co-transport activity was much higher (p < 0.05) in the upper villus cells than in the middle villus (by 29 %) and the crypt (by 30 %) cells, whereas Na(+)-Gln co-transport affinity was lower (p < 0.05) in the upper villus cells than in the middle villus and the crypt cells. The B(0)AT1 (SLC6A19) mRNA abundance was lower (p < 0.05) in the crypt (by 40-47 %) than in the villus cells. There were no significant differences in B(0)AT1 and ACE2 protein abundances on the apical membrane among the upper villus, the middle villus and the crypt cells. Our study suggests that piglet fast growth is associated with very high intestinal apical Na(+)-neutral AA uptake activities via abundantly co-expressing B(0)AT1 and ACE2 proteins in the apical membrane and by transcribing the B(0)AT1 (SLC6A19) gene in the epithelia along the entire crypt-villus axis.

Characterization of intersex production in Trichogramma kaykai infected with parthenogenesis-inducing Wolbachia

NASA Astrophysics Data System (ADS)

Tulgetske, Genet M.; Stouthamer, Richard

2012-02-01

Sexually aberrant individuals, displaying both male and female characteristics, are rare in occurrence but are documented throughout the animal kingdom. In parasitoid wasps of the genus Trichogramma, such individuals typically appear as a result of rearing Wolbachia-infected thelytokous wasps at high temperatures. Sexually aberrant Trichogramma have been referred to interchangeably in the literature as gynandromorphs, sexual mosaics and intersexes. However, accurately used, the terms "gynandromorph" and "sexual mosaic" describe an individual composed of a mixture of genetically distinct tissues corresponding to the sexual phenotypes observed, while "intersex" refers to an individual having a uniform genetic constitution but with some tissues exhibiting sexual phenotypes conflicting with the associated genotype. Here, we investigate the heat-induced production of sexually aberrant offspring by thelytokous Trichogramma kaykai. Aberrant individuals were rare, but each was characterized as one of 11 morphotypes ranging from very feminine to very masculine. Overall, the production of aberrant individuals increased with time from the onset of maternal oviposition. However, while the production of males also increased with time, the degree of masculinity of aberrant individuals did not; the different morphotypes appeared to be produced haphazardly. We conclude that the aberrant individuals produced by T. kaykai are actually intersexes and not gynandromorphs. The wasp's close association with Wolbachia and the absence of intersexes in uninfected populations allow us to discuss a possible origin of the condition.

Interspecies communication between plant and mouse gut host cells through edible plant derived exosome-like nanoparticles.

PubMed

Mu, Jingyao; Zhuang, Xiaoying; Wang, Qilong; Jiang, Hong; Deng, Zhong-Bin; Wang, Baomei; Zhang, Lifeng; Kakar, Sham; Jun, Yan; Miller, Donald; Zhang, Huang-Ge

2014-07-01

Exosomes, small vesicles participating in intercellular communication, have been extensively studied recently; however, the role of edible plant derived exosomes in interspecies communication has not been investigated. Here, we investigate the biological effects of edible plant derived exosome-like nanoparticles (EPDENs) on mammalian cells. In this study, exosome-like nanoparticles from four edible plants were isolated and characterized. We show that these EPDENs contain proteins, lipids, and microRNA. EPDENs are taken up by intestinal macrophages and stem cells. The results generated from EPDEN-transfected macrophages indicate that ginger EPDENs preferentially induce the expression of the antioxidation gene, heme oxygenase-1 and the anti-inflammatory cytokine, IL-10; whereas grapefruit, ginger, and carrot EPDENs promote activation of nuclear factor like (erythroid-derived 2). Furthermore, analysis of the intestines of canonical Wnt-reporter mice, i.e. B6.Cg-Tg(BAT-lacZ)3Picc/J mice, revealed that the numbers of β-galactosidase(+) (β-Gal) intestinal crypts are increased, suggesting that EPDEN treatment of mice leads to Wnt-mediated activation of the TCF4 transcription machinery in the crypts. The data suggest a role for EPDEN-mediated interspecies communication by inducing expression of genes for anti-inflammation cytokines, antioxidation, and activation of Wnt signaling, which are crucial for maintaining intestinal homeostasis. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Pre-treatment with Bifidobacterium breve UCC2003 modulates Citrobacter rodentium-induced colonic inflammation and organ specificity.

PubMed

Collins, James W; Akin, Ali R; Kosta, Artemis; Zhang, Ning; Tangney, Mark; Francis, Kevin P; Frankel, Gad

2012-11-01

Citrobacter rodentium, which colonizes the gut mucosa via formation of attaching and effacing (A/E) lesions, causes transmissible colonic hyperplasia. The aim of this study was to evaluate whether prophylactic treatment with Bifidobacterium breve UCC2003 can improve the outcome of C. rodentium infection. Six-week-old albino C57BL/6 mice were pre-treated for 3 days with B. breve, challenged with bioluminescent C. rodentium and administered B. breve or PBS-C for 8 days post-infection; control mice were either administered B. breve and mock-infected with PBS, or mock-treated with PBS-C and mock-infected with PBS. C. rodentium colonization was monitored by bacterial enumeration from faeces and by a combination of both 2D bioluminescence imaging (BLI) and composite 3D diffuse light imaging tomography with µCT imaging (DLIT-µCT). At day 8 post-infection, colons were removed and assessed for crypt hyperplasia, histology by light microscopy, bacterial colonization by immunofluorescence, and A/E lesion formation by electron microscopy. Prophylactic administration of B. breve did not prevent C. rodentium colonization or A/E lesion formation. However, this treatment did alter C. rodentium distribution within the large intestine and significantly reduced colonic crypt hyperplasia at the peak of bacterial infection. These results show that B. breve could not competitively exclude C. rodentium, but reduced pathogen-induced colonic inflammation.

Interspecies communication between plant and mouse gut host cells through edible plant derived exosome-like nanoparticles

PubMed Central

Mu, Jingyao; Zhuang, Xiaoying; Wang, Qilong; Jiang, Hong; Deng, Zhong-Bin; Wang, Baomei; Zhang, Lifeng; Kakar, Sham; Jun, Yan; Miller, Donald; Zhang, Huang-Ge

2015-01-01

Scope Exosomes, small vesicles participating in intercellular communication have been extensively studied recently; however, the role of edible plant derived exosomes in interspecies communication has not been investigated. Here, we investigate the biological effects of edible plant derived exosome-like nanoparticles (EPDEN) on mammalian cells. Methods and results In this study, exosome-like nanoparticles from four edible plants were isolated and characterized. We show that these EPDENs contain proteins, lipids and microRNA. EPDENs are taken up by intestinal macrophages and stem cells. The results generated from EPDEN transfected macrophages indicate that ginger EPDENs preferentially induce the expression of the anti-oxidation gene, heme oxygenase-1 (HO-1) and the anti-inflammatory cytokine, IL-10; whereas grapefruit, ginger, and carrot EPDENs promote activation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2). Furthermore, analysis of the intestines of canonical Wnt reporter mice, i.e., B6.Cg-Tg(BAT-lacZ)3Picc/J mice, revealed that the numbers of β-galactosidase+ (β-Gal) intestinal crypts are increased, suggesting that EPDEN treatment of mice leads to Wnt mediated activation of the Tcf4 transcription machinery in the crypts. Conclusion The data suggest a role for EPDEN mediated interspecies communication by inducing expression of genes for anti-inflammation cytokines, anti-oxidation and activation of Wnt signaling, which are crucial for maintaining intestinal homeostasis. PMID:24842810

Correction of cell-induced optical aberrations in a fluorescence fluctuation microscope

PubMed Central

Leroux, Charles-Edouard; Grichine, Alexei; Wang, Irène; Delon, Antoine

2013-01-01

We describe the effect of optical aberrations on fluorescence fluctuations microscopy (FFM), when focusing through a single living cell. FFM measurements are performed in an aqueous fluorescent solution, and prove to be a highly sensitive tool to assess the optical aberrations introduced by the cell. We demonstrate an adaptive optics (AO) system to remove the aberration-related bias in the FFM measurements. Our data show that AO is not only useful when imaging deep in tissues, but also when performing FFM measurements through a single cellular layer. PMID:23939061

Substance-P alleviates dextran sulfate sodium-induced intestinal damage by suppressing inflammation through enrichment of M2 macrophages and regulatory T cells.

PubMed

Hong, Hyun Sook; Hwang, Dae Yeon; Park, Ju Hyeong; Kim, Suna; Seo, Eun Jung; Son, Youngsook

2017-02-01

Intestinal inflammation alters immune responses in the mucosa and destroys colon architecture, leading to serious diseases such as inflammatory bowel disease (IBD). Thus, regulation of inflammation is regarded as the ultimate therapy for intestinal disease. Substance-P (SP) is known to mediate proliferation, migration, and cellular senescence in a variety of cells. SP was found to mobilize stem cells from bone marrow to the site of injury and to suppress inflammatory responses by inducing regulatory T cells (Tregs) and M2 macrophages. In this study, we explored the effects of SP in a dextran sodium sulfate (DSS)-induced intestine damage model. The effects of SP were evaluated by analyzing crypt structures, proliferating cells within the colon, cytokine secretion profiles, and immune cells population in the spleen/mesenteric lymph nodes in vivo. DSS treatment provoked an inflammatory response with loss of crypts in the intestines of experimental mice. This response was associated with high levels of inflammatory cytokines such as TNF-α and IL-17, and low levels of Tregs and M2 macrophages, leading to severely damaged tissue structure. However, SP treatment inhibited inflammatory responses by modulating cytokine production as well as the balance of Tregs/Th 17 cells and the M1/M2 transition in lymphoid organs, leading to accelerated tissue repair. Collectively, our data indicate that SP can promote the regeneration of tissue following damage by DSS treatment, possibly by modulating immune response. Our results propose SP as a candidate therapeutic for intestine-related inflammatory diseases. Copyright © 2016 Elsevier Ltd. All rights reserved.

Na-glutamine co-transporters B(0)AT1 in villus and SN2 in crypts are differentially altered in chronically inflamed rabbit intestine.

PubMed

Saha, Prosenjit; Arthur, Subha; Kekuda, Ramesh; Sundaram, Uma

2012-03-01

Glutamine is a major nutrient utilized by the intestinal epithelium and is primarily assimilated via Na-glutamine co-transport (NGcT) on the brush border membrane (BBM) of enterocytes. Recently we reported that B(0)AT1 (SLC6A19) mediates glutamine absorption in villus while SN2 (SLC38A5) does the same in crypt cells. However, how B(0)AT1 and SN2 are affected during intestinal inflammation is unknown. In the present study it was shown that during chronic enteritis NGcT was inhibited in villus cells, however, it was stimulated in crypt cells. Our studies also demonstrated that the mechanism of inhibition of NGcT during chronic enteritis was secondary to a reduction in the number of B(0)AT1 co-transporters in the villus cell BBM without a change in the affinity of the co-transporter. In contrast, stimulation of NGcT in crypt cells was secondary to an increase in the affinity of SN2 for glutamine without an alteration in the number of co-transporters. Thus, glutamine assimilation which occurs via distinct transporters in crypt and villus cells is altered in the chronically inflamed intestine. Copyright © 2011 Elsevier B.V. All rights reserved.

The Influence of the Aspheric Profiles for Transition Zone on Optical Performance of Human Eye After Conventional Ablation

NASA Astrophysics Data System (ADS)

Fang, L.

2014-12-01

The analysis in the impact of transition zone on the optical performance of human eye after laser refractive surgery is important for improving visual correction technology. By designing the ablation profiles of aspheric transition zone and creating the ablation profile for conventional refractive surgery in optical zone, the influence of aspheric transition zone on residual aberrations was studied. The results indicated that the ablation profiles of transition zone had a significant influence on the residual wavefront aberrations. For a hyperopia correction, the profile #9 shows a larger induced coma and spherical aberration when the translation of the centre of pupil remains constant. However, for a myopia astigmatism correction, the induced coma and spherical aberration in profile #1 shows relatively larger RMS values than those in other profiles. Therefore, the residual higher order aberrations may be decreased by optimizing ablation profiles of transition zone, but they cannot be eliminated. In order to achieve the best visual performance, the design of ablation pattern of transition zone played a crucial role.

Clustering Properties of Emission Line Selected Galaxies over the past 12.5 Gyrs

NASA Astrophysics Data System (ADS)

Khostovan, Ali Ahmad; Sobral, David; Mobasher, Bahram; Best, Philip N.; Smail, Ian; Matthee, Jorryt; Darvish, Behnam; Nayyeri, Hooshang; Hemmati, Shoubaneh; Stott, John P.

2018-01-01

In this talk, I will present my latest results on the clustering and dark matter halo (DMH) mass properties of ~7000 narrowband-selected [OIII] and [OII] emitters. I will briefly describe the past work that has been done with our samples (e.g., luminosity functions, evolution of equivalent widths) as motivation of using [OIII] and [OII] emitters to study clustering/halo properties. My talk will focus on our findings regarding the line luminosity and stellar mass dependencies with DMH mass. We find strongly increasing and redshift-independent trends between line luminosity and DMH mass with evidence for a shallower slope at the bright end consistent with halo masses of ~ 1012.5-13 M⊙. Similar, but weaker, trends between stellar mass and halo mass have also been found. We investigate the inter-dependencies of these trends on halo mass and find that the correlation with line luminosity is stronger than with stellar mass. This suggest that active galaxies may be connected with their host DMHs simply based on their emission line luminosity. If time permits, I will briefly present our most recent results using our sample of ~4000 Lyα emitters, where we find similar trends to that seen with the [OIII] and [OII] samples, as well as previous Hα measurements, which suggests galaxies selected based on emission lines may be tracing the same subpopulation of star forming galaxies. I will conclude my talk with an interpretation of this connection and suggest that the shallower slope seen for the brightest emitters is evidence for a transitional halo mass as suggested in models where quenching mechanisms truncate star formation activity and reduce the fraction of star forming galaxies with increasing halo mass.

Oral physiology, nutrition and quality of life in diabetic patients associated or not with hypertension and beta-blockers therapy.

PubMed

Pereira, L J; Foureaux, R C; Pereira, C V; Alves, M C; Campos, C H; Rodrigues Garcia, R C M; Andrade, E F; Gonçalves, T M S V

2016-07-01

The relationship between type 2 diabetes oral physiology, nutritional intake and quality of life has not been fully elucidated. We assessed the impact of type 2 diabetes - exclusive or associated with hypertension with beta-blockers treatment - on oral physiology, mastication, nutrition and quality of life. This cross-sectional study was performed with 78 complete dentate subjects (15 natural teeth and six masticatory units minimum; without removable or fixed prostheses), divided into three groups: diabetics (DM) (n = 20; 45·4 ± 9·5 years), diabetics with hypertension and receiving beta-blockers treatment (DMH) (n = 19; 41·1 ± 5·1 years) and controls (n = 39; 44·5 ± 11·7 years) matched for gender, age and socioeconomic status. Blood glucose, masticatory performance, swallowing threshold, taste, food intake, stimulated and unstimulated salivary flow, pH and buffering capacity of saliva were assessed. Glycemia was higher in DM than in controls (P < 0·01). No differences were observed between DM and controls for nutrition and quality of life. Both stimulated and unstimulated salivary flow rate were lower in DMH (P < 0·01), which also presented the lowest number of teeth and masticatory units (P < 0·0001), and reduction in the number of chewing cycles (P < 0·01). Controls showed lower Decayed Missing Filled Teeth index (DMFT) scores in comparison with DMH (P = 0·021). Masticatory performance and saliva buffering capacity were similar among groups. Exclusive type 2 diabetes did not alter oral physiology, nutrition or quality of life. However, when hypertension and beta-blockers treatment were associated with diabetes, the salivary flow rate, chewing cycles and number of teeth decreased. © 2016 John Wiley & Sons Ltd.

SMILE and Wavefront-Guided LASIK Out-Compete Other Refractive Surgeries in Ameliorating the Induction of High-Order Aberrations in Anterior Corneal Surface

PubMed Central

2016-01-01

Purpose. To compare the change of anterior corneal higher-order aberrations (HOAs) after laser in situ keratomileusis (LASIK), wavefront-guided LASIK with iris registration (WF-LASIK), femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK), and small incision lenticule extraction (SMILE). Methods. In a prospective study, 82 eyes underwent LASIK, 119 eyes underwent WF-LASIK, 88 eyes underwent FS-LASIK, and 170 eyes underwent SMILE surgery. HOAs were measured with Pentacam device preoperatively and 6 months after surgery. The aberrations were described as Zernike polynomials, and analysis focused on total HOAs, spherical aberration (SA), horizontal coma, and vertical coma over 6 mm diameter central corneal zone. Results. Six months postoperatively, all procedures result in increase of anterior corneal total HOAs and SA. There were no significant differences in the induced HOAs between LASIK and FS-LASIK, while SMILE induced fewer total HOAs and SA compared with LASIK and FS-LASIK. Similarly, WF-LASIK also induced less total HOAs than LASIK and FS-LASIK, but only fewer SA than FS-LASIK (P < 0.05). No significant difference could be detected in the induced total HOAs and SA between SMILE and WF-LASIK, whereas SMILE induced more horizontal coma and vertical coma compared with WF-LASIK (P < 0.05). Conclusion. FS-LASIK and LASIK induced comparable anterior corneal HOAs. Compared to LASIK and FS-LASIK, both SMILE and WF-LASIK showed advantages in inducing less total HOAs. In addition, SMILE also possesses better ability to reduce the induction of SA in comparison with LASIK and FS-LASIK. However, SMILE induced more horizontal coma and vertical coma compared with WF-LASIK, indicating that the centration of SMILE procedure is probably less precise than WF-LASIK. PMID:27818792

Aberration measurement of projection optics in lithographic tools based on two-beam interference theory.

PubMed

Ma, Mingying; Wang, Xiangzhao; Wang, Fan

2006-11-10

The degradation of image quality caused by aberrations of projection optics in lithographic tools is a serious problem in optical lithography. We propose what we believe to be a novel technique for measuring aberrations of projection optics based on two-beam interference theory. By utilizing the partial coherent imaging theory, a novel model that accurately characterizes the relative image displacement of a fine grating pattern to a large pattern induced by aberrations is derived. Both even and odd aberrations are extracted independently from the relative image displacements of the printed patterns by two-beam interference imaging of the zeroth and positive first orders. The simulation results show that by using this technique we can measure the aberrations present in the lithographic tool with higher accuracy.

Induction of chromosome aberrations and mitotic arrest by cytomegalovirus in human cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

AbuBakar, S.; Au, W.W.; Legator, M.S.

1988-01-01

Human cytomegalovirus (CMV) is potentially an effective but often overlooked genotoxic agent in humans. We report here evidence that indicates that infection by CMV can induce chromosome alterations and mitotic inhibition. The frequency of chromosome aberrations induced was dependent on the input multiplicity of infection (m.o.i.) for human lung fibroblasts (LU), but not for human peripheral blood lymphocytes (PBLs) when both cell types were infected at the GO phase of the cell cycle. The aberrations induced by CMV were mostly chromatid breaks and chromosome pulverizations that resembled prematurely condensed S-phase chromatin. Pulverized chromosomes were not observed in LU cells infectedmore » with virus stocks that had been rendered nonlytic by UV-irradiation at 24,000 ergs/mm2 or from infection of human lymphocytes. In LU cells infected with UV-irradiated CMV, the frequency of aberrations induced was inversely dependent on the extent of the exposure of the CMV stock to the UV-light. In permissive CMV infection of proliferating LU cells at 24 hr after subculture, a high percentage (greater than 40%) of the metaphase cells were arrested at their first metaphase and displayed severely condensed chromosomes when harvested 48 hr later. A significant increase (p less than 0.05) in the chromosome aberration frequency was also observed. Our study shows that CMV infection is genotoxic to host cells. The types and extent of damage are dependent on the viral genome expression and on the cell cycle stage of the cells at the time of infection. The possible mechanisms for induction of chromosome damage by CMV are discussed.« less

Generalized Doppler and aberration kernel for frequency-dependent cosmological observables

NASA Astrophysics Data System (ADS)

Yasini, Siavash; Pierpaoli, Elena

2017-11-01

We introduce a frequency-dependent Doppler and aberration transformation kernel for the harmonic multipoles of a general cosmological observable with spin weight s , Doppler weight d and arbitrary frequency spectrum. In the context of cosmic microwave background (CMB) studies, the frequency-dependent formalism allows to correct for the motion-induced aberration and Doppler effects on individual frequency maps with different masks. It also permits to deboost background radiations with non-blackbody frequency spectra, like extragalactic foregrounds and CMB spectra with primordial spectral distortions. The formalism can also be used to correct individual E and B polarization modes and account for motion-induced E/B mixing of polarized observables with d ≠1 at different frequencies. We apply the generalized aberration kernel on polarized and unpolarized specific intensity at 100 and 217 GHz and show that the motion-induced effects typically increase with the frequency of observation. In all-sky CMB experiments, the frequency-dependence of the motion-induced effects for a blackbody spectrum are overall negligible. However in a cut-sky analysis, ignoring the frequency dependence can lead to percent level error in the polarized and unpolarized power spectra over all angular scales. In the specific cut-sky used in our analysis (b >4 5 ° ,fsky≃14 % ), and for the dipole-inferred velocity β =0.00123 typically attributed to our peculiar motion, the Doppler and aberration effects can change polarized and unpolarized power spectra of specific intensity in the CMB rest frame by 1 - 2 % , but we find the polarization cross-leakage between E and B modes to be negligible.

Comparative Analysis of the Antineoplastic Activity of C60 Fullerene with 5-Fluorouracil and Pyrrole Derivative In Vivo

NASA Astrophysics Data System (ADS)

Lynchak, O. V.; Prylutskyy, Yu I.; Rybalchenko, V. K.; Kyzyma, O. A.; Soloviov, D.; Kostjukov, V. V.; Evstigneev, M. P.; Ritter, U.; Scharff, P.

2017-01-01

The antitumor activity of pristine C60 fullerene aqueous solution (C60FAS) compared to 5-fluorouracil (5-FU) and pyrrole derivative 1-(4-Cl-benzyl)-3-Cl-4-(CF3-fenylamino)-1H-pyrrol-2.5-dione (MI-1) cytostatic drugs was investigated and analyzed in detail using the model of colorectal cancer induced by 1.2-dimethylhydrazine (DMH) in rats. The number, size, and location of the tumors were measured, and the pathology was examined. It was found that the number of tumors and total lesion area decreased significantly under the action of C60FAS and MI-1. Because these drugs have different mechanisms of action, their simultaneous administration can potentially increase the effectiveness and significantly reduce the side effects of antitumor therapy.

Is resistant starch protective against colorectal cancer via modulation of the WNT signalling pathway?

PubMed

Malcomson, Fiona C; Willis, Naomi D; Mathers, John C

2015-08-01

Epidemiological and experimental evidence suggests that non-digestible carbohydrates (NDC) including resistant starch are protective against colorectal cancer. These anti-neoplastic effects are presumed to result from the production of the SCFA, butyrate, by colonic fermentation, which binds to the G-protein-coupled receptor GPR43 to regulate inflammation and other cancer-related processes. The WNT pathway is central to the maintenance of homeostasis within the large bowel through regulation of processes such as cell proliferation and migration and is frequently aberrantly hyperactivated in colorectal cancers. Abnormal WNT signalling can lead to irregular crypt cell proliferation that favours a hyperproliferative state. Butyrate has been shown to modulate the WNT pathway positively, affecting functional outcomes such as apoptosis and proliferation. Butyrate's ability to regulate gene expression results from epigenetic mechanisms, including its role as a histone deacetylase inhibitor and through modulating DNA methylation and the expression of microRNA. We conclude that genetic and epigenetic modulation of the WNT signalling pathway may be an important mechanism through which butyrate from fermentation of resistant starch and other NDC exert their chemoprotective effects.

RasGRP1 opposes proliferative EGFR–SOS1–Ras signals and restricts intestinal epithelial cell growth

PubMed Central

Depeille, Philippe; Henricks, Linda M.; van de Ven, Robert A. H.; Lemmens, Ed; Wang, Chih-Yang; Matli, Mary; Werb, Zena; Haigis, Kevin M.; Donner, David; Warren, Robert; Roose, Jeroen P.

2015-01-01

The character of EGFR signals can influence cell fate but mechanistic insights into intestinal EGFR-Ras signalling are limited. Here we show that two distinct Ras nucleotide exchange factors, RasGRP1 and SOS1, lie downstream of EGFR but act in functional opposition. RasGRP1 is expressed in intestinal crypts where it restricts epithelial growth. High RasGRP1 expression in colorectal cancer (CRC) patient samples correlates with a better clinical outcome. Biochemically, we find that RasGRP1 creates a negative feedback loop that limits proliferative EGFR–SOS1–Ras signals in CRC cells. Genetic Rasgrp1 depletion from mice with either an activating mutation in KRas or with aberrant Wnt signalling due to a mutation in Apc resulted in both cases in exacerbated Ras–ERK signalling and cell proliferation. The unexpected opposing cell biological effects of EGFR–RasGRP1 and EGFR–SOS1 signals in the same cell shed light on the intricacy of EGFR-Ras signalling in normal epithelium and carcinoma. PMID:26005835

Differential protective effects of red wine polyphenol extracts (RWEs) on colon carcinogenesis.

PubMed

Mazué, Frédéric; Delmas, Dominique; Murillo, Genoveva; Saleiro, Diana; Limagne, Emeric; Latruffe, Norbert

2014-04-01

Various epidemiological studies have shown that a regular and moderate consumption of red wine is correlated with a decreased relative risk of developing coronary heart disease and cancer. These health benefits are commonly attributed to high contents of polyphenols, particularly resveratrol, representing important sources of antioxidants. However, resveratrol does not seem to be the only bioactive compound present in the wine which contains numerous other polyphenols. The present study investigates the efficiency of red wine extracts (RWEs), containing different polyphenols, on colon cancer cell proliferation in vitro and on colonic aberrant crypt foci (ACF) in vivo. Proliferation, cell cycle analysis and incidence of ACF were monitored to examine the effects of RWEs. RWEs derived from a long vinification process exhibit superior anti-proliferative activity in colon cancer cells and prevent the appearance of ACF in mice. Interestingly, quercetin and resveratrol, representing two major bio-active polyphenols, exhibit synergistic anti-proliferative effects. These data suggest that the efficacy of RWEs on colon carcinogenesis may depend on the polyphenolic content, synergistic interaction of bio-active polyphenols and modulation of cellular uptake of polyphenols.

Increased variability in ApcMin/+ intestinal tissue can be measured with microultrasound

NASA Astrophysics Data System (ADS)

Fatehullah, A.; Sharma, S.; Newton, I. P.; Langlands, A. J.; Lay, H.; Nelson, S. A.; McMahon, R. K.; McIlvenny, N.; Appleton, P. L.; Cochran, S.; Näthke, I. S.

2016-07-01

Altered tissue structure is a feature of many disease states and is usually measured by microscopic methods, limiting analysis to small areas. Means to rapidly and quantitatively measure the structure and organisation of large tissue areas would represent a major advance not just for research but also in the clinic. Here, changes in tissue organisation that result from heterozygosity in Apc, a precancerous situation, are comprehensively measured using microultrasound and three-dimensional high-resolution microscopy. Despite its normal appearance in conventionally examined cross-sections, both approaches revealed a significant increase in the variability of tissue organisation in Apc heterozygous tissue. These changes preceded the formation of aberrant crypt foci or adenoma. Measuring these premalignant changes using microultrasound provides a potential means to detect microscopically abnormal regions in large tissue samples, independent of visual examination or biopsies. Not only does this provide a powerful tool for studying tissue structure in experimental settings, the ability to detect and monitor tissue changes by microultrasound could be developed into a powerful adjunct to screening endoscopy in the clinic.

Zinc Transporter SLC39A7/ZIP7 Promotes Intestinal Epithelial Self-Renewal by Resolving ER Stress

PubMed Central

Ohashi, Wakana; Kimura, Shunsuke; Iwanaga, Toshihiko; Furusawa, Yukihiro; Irié, Tarou; Izumi, Hironori; Watanabe, Takashi; Hara, Takafumi; Ohara, Osamu; Koseki, Haruhiko; Sato, Toshiro; Robine, Sylvie; Mori, Hisashi; Hattori, Yuichi; Mishima, Kenji; Ohno, Hiroshi; Hase, Koji; Fukada, Toshiyuki

2016-01-01

Zinc transporters play a critical role in spatiotemporal regulation of zinc homeostasis. Although disruption of zinc homeostasis has been implicated in disorders such as intestinal inflammation and aberrant epithelial morphology, it is largely unknown which zinc transporters are responsible for the intestinal epithelial homeostasis. Here, we show that Zrt-Irt-like protein (ZIP) transporter ZIP7, which is highly expressed in the intestinal crypt, is essential for intestinal epithelial proliferation. Mice lacking Zip7 in intestinal epithelium triggered endoplasmic reticulum (ER) stress in proliferative progenitor cells, leading to significant cell death of progenitor cells. Zip7 deficiency led to the loss of Olfm4+ intestinal stem cells and the degeneration of post-mitotic Paneth cells, indicating a fundamental requirement for Zip7 in homeostatic intestinal regeneration. Taken together, these findings provide evidence for the importance of ZIP7 in maintenance of intestinal epithelial homeostasis through the regulation of ER function in proliferative progenitor cells and maintenance of intestinal stem cells. Therapeutic targeting of ZIP7 could lead to effective treatment of gastrointestinal disorders. PMID:27736879

Measurement technique for in situ characterizing aberrations of projection optics in lithographic tools.

PubMed

Wang, Fan; Wang, Xiangzhao; Ma, Mingying

2006-08-20

As the feature size decreases, degradation of image quality caused by wavefront aberrations of projection optics in lithographic tools has become a serious problem in the low-k1 process. We propose a novel measurement technique for in situ characterizing aberrations of projection optics in lithographic tools. Considering the impact of the partial coherence illumination, we introduce a novel algorithm that accurately describes the pattern displacement and focus shift induced by aberrations. Employing the algorithm, the measurement condition is extended from three-beam interference to two-, three-, and hybrid-beam interferences. The experiments are performed to measure the aberrations of projection optics in an ArF scanner.

Complex chromosome aberrations persist in individuals many years after occupational exposure to densely ionizing radiation: an mFISH study.

PubMed

Hande, M Prakash; Azizova, Tamara V; Burak, Ludmilla E; Khokhryakov, Valentin F; Geard, Charles R; Brenner, David J

2005-09-01

Long-lived, sensitive, and specific biomarkers of particular mutagenic agents are much sought after and potentially have broad applications in the fields of cancer biology, epidemiology, and prevention. Many clastogens induce a spectrum of chromosome aberrations, and some of them can be exploited as biomarkers of exposure. Densely ionizing radiation, for example, alpha particle radiation (from radon or plutonium) and neutron radiation, preferentially induces complex chromosome aberrations, which can be detected by the 24-color multifluor fluorescence in situ hybridization (mFISH) technique. We report the detection and quantification of stable complex chromosome aberrations in lymphocytes of healthy former nuclear-weapons workers, who were exposed many years ago to plutonium, gamma rays, or both, at the Mayak weapons complex in Russia. We analyzed peripheral-blood lymphocytes from these individuals for the presence of persistent complex chromosome aberrations. A significantly elevated frequency of complex chromosome translocations was detected in the highly exposed plutonium workers but not in the group exposed only to high doses of gamma radiation. No such differences were found for simple chromosomal aberrations. The results suggest that stable complex chromosomal translocations represent a long-lived, quantitative, low-background biomarker of densely ionizing radiation for human populations exposed many years ago. (c) 2005 Wiley-Liss, Inc.

Optical aberrations induced by subclinical decentrations of the ablation pattern

NASA Astrophysics Data System (ADS)

Mrochen, Michael; Kaemmerer, Maik; Riedel, Peter; Mierdel, Peter; Krinke, Hans-Eberhard; Seiler, Theo

2000-06-01

Purpose: The aim of this work was to study the effect of currently used ablation profiles along with eccentric ablations on the increase of higher order aberrations observed after PRK. Material and Methods: The optical aberrations of 10 eyes were tested before and after PRK. Refractive surgery was performed using a ArF-excimer laser system. In all cases, the ablation zone was 6 mm or larger. The spherical equivalent of the correction was ranging from -2.5 D to -6.0 D. The measured wavefront error was compared to numerical simulations done with the reduced eye model and currently used ablation profiles as well as compared with experimental results obtained from ablation on PMMA balls. Results: The aberration measurements result in a considerable change of the spherical- and coma-like wavefront errors. This result was in good correlation with the numerical simulations and the experimental results. Furthermore, it has been derived that the major contribution on the induced higher order aberrations are a result of the small decentration (less than 1.0 mm) of the ablation zone. Conclusions: Higher order spherical- and coma-like aberrations after PRK are mainly determined by the decentration of the ablation zone during laser refractive surgery. However, future laser systems should use efficient eye-tracking systems and aspherical ablation profiles to overcome this problem.

A comparison of mode of attachment and histopathogenicity of four tapeworm species representing two orders infecting the spiral intestine of the nurse shark, Ginglymostoma cirratum.

PubMed

Borucinska, J; Caira, J N

1993-04-01

This study was undertaken to compare 2 species of Tetraphyllidea and 2 species of Trypanorhyncha with regard to the relationship between attachment structure morphology, mode of attachment, and tapeworm size, to damage at the sites of attachment in the Atlantic nurse shark, Ginglymostoma cirratum. Regions of the spiral intestine with worms attached were removed from 8 nurse sharks and sectioned according to conventional techniques. Sections of 5-50 specimens of each tapeworm species were examined. Regions of the spiral intestine devoid of worms were processed for characterization of the normal mucosa. The normal mucosa was found to consist of a folded surface covered with round-to-oval primary mucosal crypts. In the first 7 or 8 chambers of the spiral intestine the mucosal surface was thrown into secondary folds, forming ridges and secondary crypts. The primary mucosal crypts were lined with a single layer of columnar epithelium resting on a basement membrane. A highly cellular lamina propria and submucosa were found between the crypts and the muscularis mucosa. The small tetraphyllidean Pedibothrium brevispine was found with its scolex lying within the primary mucosal crypts with its hooks embedded in the basement membrane. Epithelial denudation was evident. The large tetraphyllidean Pedibothrium globicephalum was found with its bothridia engulfing large portions of the mucosa and its hooks embedded into the lamina propria. It was associated with moderate to severe mucosal necrosis. The small trypanorhynch Prochristianella tenuispine was found lying between the mucosal ridges in the secondary crypts with its tentacles either penetrating the epithelium, or occasionally, the lamina propria.(ABSTRACT TRUNCATED AT 250 WORDS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoon, Se-Chul; Park, Jeong-Mi; Jang, Hong-Seok

Captopril, an inhibitor of angiotensin I converting enzyme, has been shown to modify radiation damage and prevent radiation injury of normal tissue in rats and pigs. The present study was carried out to determine whether captopril would reduce radiation changes in the proximal small bowel in mice. Mice were subjected to whole body irradiation with 9 Gy or 15 Gy. Captopril was administered in drinking water at a regimen of 62.5 mg/kg/day (captopril group I) and 125 mg/kg/day (captopril group II), continuously from 7 days before irradiation to the end of each designed experiment. The jejunal damage was evaluated microscopicallymore » by crypt count per circumference and by histologic damage grading. Crypt number in the sham-irradiated control was 133 {plus_minus} 6.8/circumference. In both captopril group I and II, crypt numbers and histologic scores were not significantly different from those in the normal group. The 9 Gy and 15 Gy radiation alone groups showed significantly lower crypt counts and histologic scores compared with the sham-irradiated control group (p<0.05). The groups exposed to 9 Gy radiation plus captopril I and II showed significantly higher crypt counts and lower histologic damage scores on the third day, and lower histologic damage scores on the fifth day compared with the 9 Gy radiation alone group (p<0.05). The 15 Gy radiation plus captopril I and II groups had significantly higher crypt counts and lower histologic damage scores on the third day than those of the 15 Gy radiation alone group (p<0.05). All mice of the 15 Gy radiation group succumbed to intestinal radiation death. Our results suggest that captopril provides protection from acute radiation damage to the jejunal mucosa in mice. 28 refs., 5 figs., 4 tabs.« less

A kinetic model to study the regulation of β-catenin, APC, and Axin in the human colonic crypt.

PubMed

Emerick, Brooks; Schleiniger, Gilberto; Boman, Bruce M

2017-11-01

The Wnt/[Formula: see text]-catenin pathway plays a crucial role in stem cell renewal and differentiation in the normal human colonic crypt. The balance between [Formula: see text]-catenin and APC along the crypt axis determines its normal functionality. The mechanism that deregulates this balance may give insight into the initiation of colorectal cancer. This is significant because the spatial dysregulation of [Formula: see text]-catenin by the mutated tumor suppressor gene/protein APC in human colonic crypts is responsible for the initiation and growth of colorectal cancer. We consider a regulatory function that promotes APC synthesis within the cell and its effect on the accumulation of the Wnt target protein, [Formula: see text]-catenin. It is evident that an APC gradient exists along the crypt axis; however, the mechanism by which APC expression is regulated within the cell is not well known. We investigate the dynamics of an APC regulatory mechanism with an increased level of Axin at the subcellular level. Model output shows an increase of APC for a diminished Wnt signal, which explains the APC gradient along the crypt. We find that the dynamic interplay between [Formula: see text]-catenin, APC, and Axin produces oscillatory behavior, which is controlled by the Wnt stimulus. In the presence of reduced functional APC, the oscillations are amplified, which suggests that the cell remains in a more proliferative state for longer periods of time. Increased Axin levels (typical of mammalian cells) reduce oscillatory behavior and minimize the levels of [Formula: see text]-catenin within the cell while raising the levels of APC.

Unique regulation of Na-glutamine cotransporter SN2/SNAT5 in rabbit intestinal crypt cells during chronic enteritis.

PubMed

Singh, Soudamani; Arthur, Subha; Sundaram, Uma

2018-03-01

The only Na-nutrient cotransporter described in mammalian small intestinal crypt cells is SN2/SNAT5, which facilitates glutamine uptake. In a rabbit model of chronic intestinal inflammation, SN2 stimulation is secondary to an increase in affinity of the cotransporter for glutamine. However, the immune regulation of SN2 in the crypt cells during chronic intestinal inflammation is unknown. We sought to determine the mechanism of regulation of Na-nutrient cotransporter SN2 by arachidonic acid metabolites in crypt cells. The small intestines of New Zealand white male rabbits were inflamed via inoculation with Eimeria magna oocytes. After 2-week incubation, control and inflamed rabbits were subjected to intramuscular injections of arachidonyl trifluoromethyl ketone (ATK), piroxicam and MK886 for 48 hrs. After injections, the rabbits were euthanized and crypt cells from small intestines were harvested and used. Treatment of rabbits with ATK prevented the release of AA and reversed stimulation of SN2. Inhibition of cyclooxygenase (COX) with piroxicam did not affect stimulation of SN2. However, inhibition of lipoxygenase (LOX) with MK886, thus reducing leukotriene formation during chronic enteritis, reversed the stimulation of SN2. Kinetic studies showed that the mechanism of restoration of SN2 by ATK or MK886 was secondary to the restoration of the affinity of the cotransporter for glutamine. For all treatment conditions, Western blot analysis revealed no change in SN2 protein levels. COX inhibition proved ineffective at reversing the stimulation of SN2. Thus, this study provides evidence that SN2 stimulation in crypt cells is mediated by the leukotriene pathway during chronic intestinal inflammation. © 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

A Combined Theoretical and Experimental Study for Silver Electroplating

PubMed Central

Liu, Anmin; Ren, Xuefeng; An, Maozhong; Zhang, Jinqiu; Yang, Peixia; Wang, Bo; Zhu, Yongming; Wang, Chong

2014-01-01

A novel method combined theoretical and experimental study for environmental friendly silver electroplating was introduced. Quantum chemical calculations and molecular dynamic (MD) simulations were employed for predicting the behaviour and function of the complexing agents. Electronic properties, orbital information, and single point energies of the 5,5-dimethylhydantoin (DMH), nicotinic acid (NA), as well as their silver(I)-complexes were provided by quantum chemical calculations based on density functional theory (DFT). Adsorption behaviors of the agents on copper and silver surfaces were investigated using MD simulations. Basing on the data of quantum chemical calculations and MD simulations, we believed that DMH and NA could be the promising complexing agents for silver electroplating. The experimental results, including of electrochemical measurement and silver electroplating, further confirmed the above prediction. This efficient and versatile method thus opens a new window to study or design complexing agents for generalized metal electroplating and will vigorously promote the level of this research region. PMID:24452389

Painting Analysis of Chromosome Aberrations Induced by Energetic Heavy Ions in Human Cells

NASA Technical Reports Server (NTRS)

Wu, Honglu; Hada, Megumi; Cucinotta, Francis

2007-01-01

This viewgraph presentation reviews some of the techniques used to analyze the damage done to chromosome from ion radiation. Fluorescence in situ hybridization (FISH), mFISH, mBAND, telomere and centromereprobes have been used to study chromosome aberrations induced in human cells exposed to low-and high-LET radiation in vitro. There is some comparison of the different results from the various techniques. The results of the study are summarized.

Crypt dynamics and colorectal cancer: advances in mathematical modelling.

PubMed

van Leeuwen, I M M; Byrne, H M; Jensen, O E; King, J R

2006-06-01

Mathematical modelling forms a key component of systems biology, offering insights that complement and stimulate experimental studies. In this review, we illustrate the role of theoretical models in elucidating the mechanisms involved in normal intestinal crypt dynamics and colorectal cancer. We discuss a range of modelling approaches, including models that describe cell proliferation, migration, differentiation, crypt fission, genetic instability, APC inactivation and tumour heterogeneity. We focus on the model assumptions, limitations and applications, rather than on the technical details. We also present a new stochastic model for stem-cell dynamics, which predicts that, on average, APC inactivation occurs more quickly in the stem-cell pool in the absence of symmetric cell division. This suggests that natural niche succession may protect stem cells against malignant transformation in the gut. Finally, we explain how we aim to gain further understanding of the crypt system and of colorectal carcinogenesis with the aid of multiscale models that cover all levels of organization from the molecular to the whole organ.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Craig, Timothy; Smith, Andrew D.; Holder, Gareth M.

The development of more accurate and sensitive diagnostic techniques is a key factor in efforts to improve cancer survival rates. The technique of infrared aperture fibre scanning near-field optical microscopy (IR-SNOM),together with radiation from the infrared free-electron laser (IR-FEL) on ALICEat Daresbury Laboratory (UK), has been used to obtain IR images of a crypt-like feature and the surrounding tissue; the tissue was taken from a patient with oesophageal adenocarcinoma and with a history of Barrett’s oesophagus. We have shown that the DNA signal is enhanced relative to other contributions in the region of the crypt, and the glycoprotein signal showsmore » a less pronounced increase in the region of the crypt. The Amide II signal is found to be anti-correlated with the DNA and glycoprotein profiles. The absorbance of the Amide II signal is found to differ for three different types of cancer tissue. In conclusion, high-resolution IR images of the crypt reveal additional structure that would not be resolved in diffraction-limited techniques.« less

Maternal Methyl Donor Supplementation during Gestation Counteracts the Bisphenol A-Induced Impairment of Intestinal Morphology, Disaccharidase Activity, and Nutrient Transporters Gene Expression in Newborn and Weaning Pigs

PubMed Central

Liu, Hong; Wang, Jun; Mou, Daolin; Che, Lianqiang; Fang, Zhengfeng; Feng, Bin; Lin, Yan; Xu, Shengyu; Li, Jian; Wu, De

2017-01-01

This study was conducted to explore whether exposure to bisphenol A (BPA) during pregnancy could change intestinal digestion and absorption function in offspring using pigs as a model, and whether methyl donor (MET) could counteract the BPA-induced impacts. Fifty Landrace × Yorkshire sows were divided into four dietary groups throughout gestation: control diet (CON); control diet supplemented with BPA (50 mg/kg); control diet supplemented with MET (3 g/kg betaine, 400 mg/kg choline, 150 μg/kg vitamin B12, and 15 mg/kg folic acid); and control diet with BPA and MET supplementation (BPA + MET). Intestine samples were collected from pigs’ offspring at birth and weaning. Maternal BPA exposure during pregnancy significantly reduced the ratio of jejunum villus height to crypt depth, decreased the jejunum sucrase activity, down-regulated the mRNA expression of jejunum peptide transporter 1 (Pept1) and DNA methyl transferase 3a (DNMT3a), and decreased the DNA methylation level of jejunum Pept1 in offspring (p < 0.05). Maternal MET supplementation significantly raised the ratio of villus height to crypt depth in jejunum and ileum, improved the jejunum lactase activity, up-regulated the mRNA expression of jejunum Pept1, lactase (LCT), DNMT1, DNMT3a, and methylenetetrahydrofolate reductase (MTHFR), and increased the DNA methylation level of jejunum Pept1 in offspring (p < 0.05). However, the ratio of jejunum villus height to crypt depth was higher in BPA + MET treatment compared with CON and BPA treatment (p < 0.05). Meanwhile, there was no difference in the jejunum sucrase activity, the mRNA expression of jejunum Pept1 and DNMT3a, and the DNA methylation level of jejunum Pept1 between CON and BPA + MET treatment. These results indicated that maternal exposure to BPA during gestation might suppress offspring’s intestinal digestion and absorption function, whereas supplementation of MET could counteract these damages, which might be associated with DNA methylation. PMID:28445388

Chromosome damage evolution after low and high LET irradiation

NASA Astrophysics Data System (ADS)

Andreev, Sergey; Eidelman, Yuri

Ionizing radiation induces DNA and chromatin lesions which are converted to chromosome lesions detected in the first post-irradiation mitosis by classic cytogenetic techniques as chromosomal aberrations (CAs). These techniques allow to monitor also delayed aberrations observed after many cell generations post-irradiation - the manifestation of chromosomal instability phenotype (CIN). The problem discussed is how to predict time evolution from initial to delayed DNA/chromosome damage. To address this question, in the present work a mechanistic model of CIN is elaborated which integrates pathways of (*) DNA damage induction and its conversion to chromosome lesions (aberrations), (**) lesion transmission and generation through cell cycles. Delayed aberrations in subsequent cycles are formed in the model owing to two pathways, DNA damage generation de novo as well as CA transmission from previous cycles. DNA damage generation rate is assumed to consist of bystander and non-bystander components. Bystander signals impact all cells roughly equally, whereas non-bystander DSB generation rate differs for the descendants of unirradiated and irradiated cells. Monte Carlo simulation of processes underlying CIN allows to predict the time evolution of initial radiation-induced damage - kinetics curve for delayed unstable aberrations (dicentrics) together with dose response and RBE as a function of time after high vs low LET irradiation. The experimental data for radiation-induced CIN in TK6 lymphoblastoid cells and human lymphocytes irradiated with low (gamma) and high (Fe, C) LET radiation are analyzed on the basis of the proposed model. One of the conclusions is that without bystander signaling, just taking into account the initial DNA damage and non-bystander DSB generation, it is impossible to describe the available experimental data for high-LET-induced CIN. The exact contribution of bystander effects for high vs low LET remains unknown, but the relative contribution may be assessed at large times after initial acute irradiation. RBE for delayed aberrations depends on LET, time and cell line, which probably reflects a genetic background for bystander component. The proposed modeling approach creates a basis for integration of complex network of bystander/inflammatory signaling in systems-level platform for quantification of radiation induced CIN.

Capture and 3D culture of colonic crypts and colonoids in a microarray platform.

PubMed

Wang, Yuli; Ahmad, Asad A; Shah, Pavak K; Sims, Christopher E; Magness, Scott T; Allbritton, Nancy L

2013-12-07

Crypts are the basic structural and functional units of colonic epithelium and can be isolated from the colon and cultured in vitro into multi-cell spheroids termed "colonoids". Both crypts and colonoids are ideal building blocks for construction of an in vitro tissue model of the colon. Here we proposed and tested a microengineered platform for capture and in vitro 3D culture of colonic crypts and colonoids. An integrated platform was fabricated from polydimethylsiloxane which contained two fluidic layers separated by an array of cylindrical microwells (150 μm diameter, 150 μm depth) with perforated bottoms (30 μm opening, 10 μm depth) termed "microstrainers". As fluid moved through the array, crypts or colonoids were retained in the microstrainers with a >90% array-filling efficiency. Matrigel as an extracellular matrix was then applied to the microstrainers to generate isolated Matrigel pockets encapsulating the crypts or colonoids. After supplying the essential growth factors, epidermal growth factor, Wnt-3A, R-spondin 2 and noggin, 63 ± 13% of the crypts and 77 ± 8% of the colonoids cultured in the microstrainers over a 48-72 h period formed viable 3D colonoids. Thus colonoid growth on the array was similar to that under standard culture conditions (78 ± 5%). Additionally the colonoids displayed the same morphology and similar numbers of stem and progenitor cells as those under standard culture conditions. Immunofluorescence staining confirmed that the differentiated cell-types of the colon, goblet cells, enteroendocrine cells and absorptive enterocytes, formed on the array. To demonstrating the utility of the array in tracking the colonoid fate, quantitative fluorescence analysis was performed on the arrayed colonoids exposed to reagents such as Wnt-3A and the γ-secretase inhibitor LY-411575. The successful formation of viable, multi-cell type colonic tissue on the microengineered platform represents a first step in the building of a "colon-on-a-chip" with the goal of producing the physiologic structure and organ-level function of the colon for controlled experiments.

Dietary l-threonine supplementation attenuates lipopolysaccharide-induced inflammatory responses and intestinal barrier damage of broiler chickens at an early age.

PubMed

Chen, Yueping; Zhang, Hao; Cheng, Yefei; Li, Yue; Wen, Chao; Zhou, Yanmin

2018-06-01

This study was conducted to investigate the protective effects of l-threonine (l-Thr) supplementation on growth performance, inflammatory responses and intestinal barrier function of young broilers challenged with lipopolysaccharide (LPS). A total of 144 1-d-old male chicks were allocated to one of three treatments: non-challenged broilers fed a basal diet (control group), LPS-challenged broilers fed a basal diet without l-Thr supplementation and LPS-challenged broilers fed a basal diet supplemented with 3·0 g/kg l-Thr. LPS challenge was performed intraperitoneally at 17, 19 and 21 d of age, whereas the control group received physiological saline injection. Compared with the control group, LPS challenge impaired growth performance of broilers, and l-Thr administration reversed LPS-induced increase in feed/gain ratio. LPS challenge elevated blood cell counts related to inflammation, and pro-inflammatory cytokine concentrations in serum (IL-1β and TNF-α), spleen (IL-1β and TNF-α) and intestinal mucosa (jejunal interferon-γ (IFN-γ) and ileal IL-1β). The concentrations of intestinal cytokines in LPS-challenged broilers were reduced by l-Thr supplementation. LPS administration increased circulating d-lactic acid concentration, whereas it reduced villus height, the ratio between villus height and crypt depth and goblet density in both jejunum and ileum. LPS-induced decreases in jejunal villus height, intestinal villus height:crypt depth ratio and ileal goblet cell density were reversed with l-Thr supplementation. Similarly, LPS-induced alterations in the intestinal mRNA abundances of genes related to intestinal inflammation and barrier function (jejunal toll-like receptor 4, IFN- γ and claudin-3, and ileal IL-1 β and zonula occludens-1) were normalised with l-Thr administration. It can be concluded that l-Thr supplementation could attenuate LPS-induced inflammatory responses and intestinal barrier damage of young broilers.

Conditional knockout of the leptin receptor in the colonic epithelium revealed the local effects of leptin receptor signaling in the progression of colonic tumors in mice.

PubMed

Higurashi, Takuma; Endo, Hiroki; Uchiyama, Takashi; Uchiyama, Shiori; Yamada, Eiji; Ohkubo, Hidenori; Sakai, Eiji; Takahashi, Hirokazu; Maeda, Shin; Wada, Koichiro; Natsumeda, Yutaka; Hippo, Yoshitaka; Nakajima, Atsushi; Nakagama, Hitoshi

2014-09-01

Leptin, secreted by the adipose tissue and known to be related to obesity, is considered to be involved in the onset and progression of colorectal cancer. However, the exact role of leptin in colorectal carcinogenesis is still unclear, as several controversial reports have been published on the various systemic effects of leptin. The aim of this study was to clarify the local and precise roles of leptin receptor (LEPR)-mediated signaling in colonic carcinogenesis using intestinal epithelium-specific LEPRb conditional knockout (cKO) mice. We produced and used colonic epithelium-specific LEPRb cKO mice to investigate the carcinogen-induced formation of aberrant crypt foci (ACF) and tumors in the colon, using their littermates as control. There were no differences in the body weight or systemic condition between the control and cKO mice. The tumor sizes and number of large-sized tumors were significantly lower in the cKO mice as compared with those in the control mice. On the other hand, there was no significant difference in the proliferative activity of the normal colonic epithelial cells or ACF formation between the control and cKO mice. In the control mice, marked increase of the LEPRb expression level was observed in the colonic tumors as compared with that in the normal epithelium; furthermore, signal transducer and activator of transcription (STAT3) was activated in the tumor cells. These findings suggest that STAT3 is one of the important molecules downstream of LEPRb, and LEPRb/STAT3 signaling controls tumor cell proliferation. We demonstrated the importance of local/regional LEPR-mediated signaling in colorectal carcinogenesis. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.