Prevention of gastrointestinal lead poisoning using recombinant Lactococcus lactis expressing human metallothionein-I fusion protein.

PubMed

Xiao, Xue; Zhang, Changbin; Liu, Dajun; Bai, Weibin; Zhang, Qihao; Xiang, Qi; Huang, Yadong; Su, Zhijian

2016-04-05

Low-level lead poisoning is an insidious disease that affects millions of children worldwide, leading to biochemical and neurological dysfunctions. Blocking lead uptake via the gastrointestinal tract is an important prevention strategy. With this in mind, we constructed the recombinant Lactococcus lactis strain pGSMT/MG1363, which constitutively expressed the fusion protein glutathione S-transferase (GST)-small molecule ubiquitin-like modifier protein (SUMO)-metallothionein-I (GST-SUMO-MT). The thermodynamic data indicated that the average number of lead bound to a GST-SUMO-MT molecule was 3.655 and this binding reaction was a spontaneous, exothermic and entropy-increasing process. The total lead-binding capacity of pGSMT/MG1363 was 4.11 ± 0.15 mg/g dry mass. Oral administration of pGSMT/MG1363 (1 × 10(10) Colony-Forming Units) to pubertal male rats that were also treated with 5 mg/kg of lead acetate daily significantly inhibited the increase of blood lead levels, the impairment of hepatic function and the decrease of testosterone concentration in the serum, which were all impaired in rats treated by lead acetate alone. Moreover, the administration of pGSMT/MG1363 for 6 weeks did not affect the serum concentration of calcium, magnesium, potassium or sodium ions. This study provides a convenient and economical biomaterial for preventing lead poisoning via the digestive tract.

Modulation of nitric oxide-mediated metal release from metallothionein by the redox state of glutathione in vitro.

PubMed

Khatai, Leila; Goessler, Walter; Lorencova, Helena; Zangger, Klaus

2004-06-01

Metallothioneins (MTs) release bound metals when exposed to nitric oxide. At inflammatory sites, both metallothionein and inducible nitric oxide synthase (iNOS) are induced by the same factors and the zinc released from metallothionein by NO suppresses both the induction and activity of iNOS. In a search for a possible modulatory mechanism of this coexpression of counteracting proteins, we investigated the role of the glutathione redox state in vitro because the oxidation state of thiols is involved in the metal binding in Cd-S or Zn-S clusters found in metallothioneins, and NO also binds to reduced glutathione via S-nitrosation. Using a variety of techniques, we found that NO and also ONOO(-)-mediated metal release from purified MTs is suppressed by reduced glutathione (GSH), but not by oxidized glutathione. Considering the millimolar concentrations of GSH present in mammalian cells, the metal release from MTs by NO should play no role in living systems. Therefore, the fact that it has been observed in vivo points to a hitherto unknown mechanism or additional compound(s) being involved in this physiologically relevant reaction and as long as this additional factor is not found experimental results on the MT-NO interaction should be treated with caution. Contrary to the peroxynitrite-induced activation of guanylyl cyclase, where GSH is needed, we found that the metal release from metallothionein by peroxynitrite is not enhanced, but also suppressed by reduced glutathione. In addition, we show that zinc, the major natural metal ligand in mammalian MTs and suppressor of iNOS, is released more readily under the influence of NO than cadmium, but in contrast to the MT isoform 1, the amount of metal released from the beta-domain of MT-2 is comparable to that from the alpha-domain.

Metallothionein blocks oxidative DNA damage induced by acute inorganic arsenic exposure

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

Qu, Wei, E-mail: qu@niehs.nih.gov; Waalkes, Michael P.

We studied how protein metallothionein (MT) impacts arsenic-induced oxidative DNA damage (ODD) using cells that poorly express MT (MT-I/II double knockout embryonic cells; called MT-null cells) and wild-type (WT) MT competent cells. Arsenic (as NaAsO{sub 2}) was less cytolethal over 24 h in WT cells (LC{sub 50} = 11.0 ± 1.3 μM; mean ± SEM) than in MT-null cells (LC{sub 50} = 5.6 ± 1.2 μM). ODD was measured by the immuno-spin trapping method. Arsenic (1 or 5 μM; 24 h) induced much less ODD in WT cells (121% and 141% of control, respectively) than in MT-null cells (202% andmore » 260%). In WT cells arsenic caused concentration-dependent increases in MT expression (transcript and protein), and in the metal-responsive transcription factor-1 (MTF-1), which is required to induce the MT gene. In contrast, basal MT levels were not detectable in MT-null cells and unaltered by arsenic exposure. Transfection of MT-I gene into the MT-null cells markedly reduced arsenic-induced ODD levels. The transport genes, Abcc1 and Abcc2 were increased by arsenic in WT cells but either showed no or very limited increases in MT-null cells. Arsenic caused increases in oxidant stress defense genes HO-1 and GSTα2 in both WT and MT-null cells, but to much higher levels in WT cells. WT cells appear more adept at activating metal transport systems and oxidant response genes, although the role of MT in these responses is unclear. Overall, MT protects against arsenic-induced ODD in MT competent cells by potential sequestration of scavenging oxidant radicals and/or arsenic. - Highlights: • Metallothionein blocks arsenic toxicity. • Metallothionein reduces arsenic-induced DNA damage. • Metallothionein may bind arsenic or radicals produced by arsenic.« less

Roles of zinc and metallothionein-3 in oxidative stress-induced lysosomal dysfunction, cell death, and autophagy in neurons and astrocytes.

PubMed

Lee, Sook-Jeong; Koh, Jae-Young

2010-10-26

Zinc dyshomeostasis has been recognized as an important mechanism for cell death in acute brain injury. An increase in the level of free or histochemically reactive zinc in astrocytes and neurons is considered one of the major causes of death of these cells in ischemia and trauma. Although zinc dyshomeostasis can lead to cell death via diverse routes, the major pathway appears to involve oxidative stress.Recently, we found that a rise of zinc in autophagic vacuoles, including autolysosomes, is a prerequisite for lysosomal membrane permeabilization and cell death in cultured brain cells exposed to oxidative stress conditions. The source of zinc in this process is likely redox-sensitive zinc-binding proteins such as metallothioneins, which release zinc under oxidative conditions. Of the metallothioneins, metallothionein-3 is especially enriched in the central nervous system, but its physiologic role in this tissue is not well established. Like other metallothioneins, metallothionein-3 may function as metal detoxicant, but is also known to inhibit neurite outgrowth and, sometimes, promote neuronal death, likely by serving as a source of toxic zinc release. In addition, metallothionein-3 regulates lysosomal functions. In the absence of metallothionein-3, there are changes in lysosome-associated membrane protein-1 and -2, and reductions in certain lysosomal enzymes that result in decreased autophagic flux. This may have dual effects on cell survival. In acute oxidative injury, zinc dyshomeostasis and lysosomal membrane permeabilization are diminished in metallothionein-3 null cells, resulting in less cell death. But over the longer term, diminished lysosomal function may lead to the accumulation of abnormal proteins and cause cytotoxicity.The roles of zinc and metallothionein-3 in autophagy and/or lysosomal function have just begun to be investigated. In light of evidence that autophagy and lysosomes may play significant roles in the pathogenesis of various neurological

Metallothionein-3 Increases Triple-Negative Breast Cancer Cell Invasiveness via Induction of Metalloproteinase Expression

PubMed Central

Suchanski, Jaroslaw; Olbromski, Mateusz; Gomulkiewicz, Agnieszka; Owczarek, Tomasz; Kruczak, Anna; Ambicka, Aleksandra; Rys, Janusz; Ugorski, Maciej; Podhorska-Okolow, Marzena; Dziegiel, Piotr

2015-01-01

It has been recently found that metallothionein-3 (MT3) enhances the invasiveness and tumorigenesis of prostate cancer cells. This finding is in contrast to those of earlier studies, which indicated that overexpression of MT3 in breast cancer and prostate cancer cell lines inhibits their growth in vitro. Therefore, to clarify the role of MT3 in breast cancer progression, we analyzed the effect of MT3-overexpression on proliferation, invasiveness, migration, and tumorigenesis of breast cancer MDA-MB-231/BO2 cells. It was found that MDA-MB-231/BO2 cells overexpressing MT3 were characterized by increased invasiveness in vitro, compared to the control cells. Interestingly, this increased invasiveness correlated with a highly increased concentration of MMP3 in the culture supernatants (p<0.0001). Our data suggest that MT3 may regulate breast cancer cell invasiveness by modulating the expression of MMP3. These experimental results, obtained using triple-negative MDA-MB-231/BO2 cells, were further supported by clinical data. It was found that, in triple-negative breast cancer (TNBC), nuclear MT3 immunoreactivity in cancer cells tended to be associated with patients’ shorter disease-specific survival, suggesting that nuclear MT3 expression may be a potential marker of poor prognosis of triple-negative TNBC cases. PMID:25933064

Prevention of gastrointestinal lead poisoning using recombinant Lactococcus lactis expressing human metallothionein-I fusion protein

PubMed Central

Xiao, Xue; Zhang, Changbin; Liu, Dajun; Bai, Weibin; Zhang, Qihao; Xiang, Qi; Huang, Yadong; Su, Zhijian

2016-01-01

Low-level lead poisoning is an insidious disease that affects millions of children worldwide, leading to biochemical and neurological dysfunctions. Blocking lead uptake via the gastrointestinal tract is an important prevention strategy. With this in mind, we constructed the recombinant Lactococcus lactis strain pGSMT/MG1363, which constitutively expressed the fusion protein glutathione S-transferase (GST)–small molecule ubiquitin-like modifier protein (SUMO)–metallothionein-I (GST-SUMO-MT). The thermodynamic data indicated that the average number of lead bound to a GST-SUMO-MT molecule was 3.655 and this binding reaction was a spontaneous, exothermic and entropy-increasing process. The total lead-binding capacity of pGSMT/MG1363 was 4.11 ± 0.15 mg/g dry mass. Oral administration of pGSMT/MG1363 (1 × 1010 Colony-Forming Units) to pubertal male rats that were also treated with 5 mg/kg of lead acetate daily significantly inhibited the increase of blood lead levels, the impairment of hepatic function and the decrease of testosterone concentration in the serum, which were all impaired in rats treated by lead acetate alone. Moreover, the administration of pGSMT/MG1363 for 6 weeks did not affect the serum concentration of calcium, magnesium, potassium or sodium ions. This study provides a convenient and economical biomaterial for preventing lead poisoning via the digestive tract. PMID:27045906

Overexpression of spinach non-symbiotic hemoglobin in Arabidopsis resulted in decreased NO content and lowered nitrate and other abiotic stresses tolerance

PubMed Central

Bai, Xuegui; Long, Juan; He, Xiaozhao; Yan, Jinping; Chen, Xuanqin; Tan, Yong; Li, Kunzhi; Chen, Limei; Xu, Huini

2016-01-01

A class 1 non-symbiotic hemoglobin family gene, SoHb, was isolated from spinach. qRT-PCR showed that SoHb was induced by excess nitrate, polyethylene glycol, NaCl, H2O2, and salicylic acid. Besides, SoHb was strongly induced by application of nitric oxide (NO) donor, while was suppressed by NO scavenger, nitrate reductase inhibitor, and nitric oxide synthase inhibitor. Overexpression of SoHb in Arabidopsis resulted in decreased NO level and sensitivity to nitrate stress, as shown by reduced root length, fresh weight, the maximum photosystem II quantum ratio of variable to maximum fluorescence (Fv/Fm), and higher malondialdehyde contents. The activities and gene transcription of superoxide dioxidase, and catalase decreased under nitrate stress. Expression levels of RD22, RD29A, DREB2A, and P5CS1 decreased after nitrate treatment in SoHb-overexpressing plants, while increased in the WT plants. Moreover, SoHb-overexpressing plants showed decreased tolerance to NaCl and osmotic stress. In addition, the SoHb-overexpression lines showed earlier flower by regulating the expression of SOC, GI and FLC genes. Our results indicated that the decreasing NO content in Arabidopsis by overexpressing SoHb might be responsible for lowered tolerance to nitrate and other abiotic stresses. PMID:27211528

Blockade of Metallothioneins 1 and 2 Increases Skeletal Muscle Mass and Strength

PubMed Central

Summermatter, Serge; Bouzan, Anais; Pierrel, Eliane; Melly, Stefan; Stauffer, Daniela; Gutzwiller, Sabine; Nolin, Erin; Dornelas, Christina; Fryer, Christy; Leighton-Davies, Juliet; Glass, David J.

2016-01-01

ABSTRACT Metallothioneins are proteins that are involved in intracellular zinc storage and transport. Their expression levels have been reported to be elevated in several settings of skeletal muscle atrophy. We therefore investigated the effect of metallothionein blockade on skeletal muscle anabolism in vitro and in vivo. We found that concomitant abrogation of metallothioneins 1 and 2 results in activation of the Akt pathway and increases in myotube size, in type IIb fiber hypertrophy, and ultimately in muscle strength. Importantly, the beneficial effects of metallothionein blockade on muscle mass and function was also observed in the setting of glucocorticoid addition, which is a strong atrophy-inducing stimulus. Given the blockade of atrophy and the preservation of strength in atrophy-inducing settings, these results suggest that blockade of metallothioneins 1 and 2 constitutes a promising approach for the treatment of conditions which result in muscle atrophy. PMID:27956698

Differential metallothionein expression in oral lichen planus and amalgam-associated oral lichenoid lesions

PubMed Central

Mendes, Gabriela-Geraldo; Servato, João-Paulo-Silva; Borges, Fabiana-Custódio; Rosa, Roberta-Rezende; Siqueira, Carla-Silva; de Faria, Paulo-Rogério; Loyola, Adriano-Mota

2018-01-01

Background Oral lichen planus (OLP) is a chronic inflammatory disease mediated by T cells, which manifests as reticular (white) or erosive (red) lesions, that are eventually painful. Oral lichenoid lesion (OLL) are distinguished from OLP by the presence of precipitating factors. The aim of this study was to evaluate whether the presence of metallothionein, which is involved in anti-apoptotic pathways and the anti-oxidative response, could serve as a differential diagnostic for OLP and OLL. Material and Methods We evaluated the expression of metallothionein in 40 cases of OLP and 20 cases of OLL using immunohistochemistry. Results and Conclusions White OLP has higher concentrations of metallothionein than red OLP in basal and parabasal layers. Moreover, metallothionein was more frequently observed in the cytoplasm and nuclei of basal cells in OLP patients compared to the same regions of OLL cases. Metallothionein levels are related to OLP severity and may contribute to a differential diagnosis between OLP and OLL. Key words:Oral lichen planus, oral lichenoid lesions, autoimmune disorders, metallothionein, immunohistochemistry. PMID:29680841

Overexpression of the class I homeodomain transcription factor TaHDZipI-5 increases drought and frost tolerance in transgenic wheat.

PubMed

Yang, Yunfei; Luang, Sukanya; Harris, John; Riboni, Matteo; Li, Yuan; Bazanova, Natalia; Hrmova, Maria; Haefele, Stephan; Kovalchuk, Nataliya; Lopato, Sergiy

2018-06-01

Characterization of the function of stress-related genes helps to understand the mechanisms of plant responses to environmental conditions. The findings of this work defined the role of the wheat TaHDZipI-5 gene, encoding a stress-responsive homeodomain-leucine zipper class I (HD-Zip I) transcription factor, during the development of plant tolerance to frost and drought. Strong induction of TaHDZipI-5 expression by low temperatures, and the elevated TaHDZipI-5 levels of expression in flowers and early developing grains in the absence of stress, suggests that TaHDZipI-5 is involved in the regulation of frost tolerance at flowering. The TaHDZipI-5 protein behaved as an activator in a yeast transactivation assay, and the TaHDZipI-5 activation domain was localized to its C-terminus. The TaHDZipI-5 protein homo- and hetero-dimerizes with related TaHDZipI-3, and differences between DNA interactions in both dimers were specified at 3D molecular levels. The constitutive overexpression of TaHDZipI-5 in bread wheat significantly enhanced frost and drought tolerance of transgenic wheat lines with the appearance of undesired phenotypic features, which included a reduced plant size and biomass, delayed flowering and a grain yield decrease. An attempt to improve the phenotype of transgenic wheat by the application of stress-inducible promoters with contrasting properties did not lead to the elimination of undesired phenotype, apparently due to strict spatial requirements for TaHDZipI-5 overexpression. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

Propylthiouracil, Perchlorate, and Thyroid-Stimulating Hormone Modulate High Concentrations of Iodide Instigated Mitochondrial Superoxide Production in the Thyroids of Metallothionein I/II Knockout Mice

PubMed Central

Duan, Qi; Wang, Tingting; Zhang, Na; Perera, Vern; Liang, Xue; Abeysekera, Iruni Roshanie

2016-01-01

Background Increased oxidative stress has been suggested as one of the underlying mechanisms in iodide excess-induced thyroid disease. Metallothioneins (MTs) are regarded as scavengers of reactive oxygen species (ROS) in oxidative stress. Our aim is to investigate the effects of propylthiouracil (PTU), a thyroid peroxidase inhibitor, perchlorate (KClO4), a competitive inhibitor of iodide transport, and thyroid stimulating hormone (TSH) on mitochondrial superoxide production instigated by high concentrations of iodide in the thyroids of MT-I/II knockout (MT-I/II KO) mice. Methods Eight-week-old 129S7/SvEvBrd-Mt1tm1Bri Mt2tm1Bri/J (MT-I/II KO) mice and background-matched wild type (WT) mice were used. Results By using a mitochondrial superoxide indicator (MitoSOX Red), lactate dehydrogenase (LDH) release, and methyl thiazolyl tetrazolium (MTT) assay, we demonstrated that the decreased relative viability and increased LDH release and mitochondrial superoxide production induced by potassium iodide (100 µM) can be relieved by 300 µM PTU, 30 µM KClO4, or 10 U/L TSH in the thyroid cell suspensions of both MT-I/II KO and WT mice (P<0.05). Compared to the WT mice, a significant decrease in the relative viability along with a significant increase in LDH release and mitochondrial superoxide production were detected in MT-I/II KO mice(P<0.05). Conclusion We concluded that PTU, KClO4, or TSH relieved the mitochondrial oxidative stress induced by high concentrations of iodide in the thyroids of both MT-I/II KO and WT mice. MT-I/II showed antioxidant effects against high concentrations of iodide-induced mitochondrial superoxide production in the thyroid. PMID:26754589

Differential metallothionein expression in oral lichen planus and amalgam-associated oral lichenoid lesions.

PubMed

Mendes, G-G; Servato, J-P-S; Borges, F-C; Rosa, R-R; Siqueira, C-S; de Faria, P-R; Loyola, A-M; Cardoso, S-V

2018-05-01

Oral lichen planus (OLP) is a chronic inflammatory disease mediated by T cells, which manifests as reticular (white) or erosive (red) lesions, that are eventually painful. Oral lichenoid lesion (OLL) are distinguished from OLP by the presence of precipitating factors. The aim of this study was to evaluate whether the presence of metallothionein, which is involved in anti-apoptotic pathways and the anti-oxidative response, could serve as a differential diagnostic for OLP and OLL. We evaluated the expression of metallothionein in 40 cases of OLP and 20 cases of OLL using immunohistochemistry. White OLP has higher concentrations of metallothionein than red OLP in basal and parabasal layers. Moreover, metallothionein was more frequently observed in the cytoplasm and nuclei of basal cells in OLP patients compared to the same regions of OLL cases. Metallothionein levels are related to OLP severity and may contribute to a differential diagnosis between OLP and OLL.

A Family Knockout of All Four Drosophila Metallothioneins Reveals a Central Role in Copper Homeostasis and Detoxification†

PubMed Central

Egli, Dieter; Yepiskoposyan, Hasmik; Selvaraj, Anand; Balamurugan, Kuppusamy; Rajaram, Rama; Simons, Andreas; Multhaup, Gerd; Mettler, Simone; Vardanyan, Alla; Georgiev, Oleg; Schaffner, Walter

2006-01-01

Metallothioneins are ubiquitous, small, cysteine-rich proteins with the ability to bind heavy metals. In spite of their biochemical characterization, their in vivo function remains elusive. Here, we report the generation of a metallothionein gene family knockout in Drosophila melanogaster by targeted disruption of all four genes (MtnA to -D). These flies are viable if raised in standard laboratory food. During development, however, they are highly sensitive to copper, cadmium, and (to a lesser extent) zinc load. Metallothionein expression is particularly important for male viability; while copper load during development affects males and females equally, adult males lacking metallothioneins display a severely reduced life span, possibly due to copper-mediated oxidative stress. Using various reporter gene constructs, we find that different metallothioneins are expressed with virtually the same tissue specificity in larvae, notably in the intestinal tract at sites of metal accumulation, including the midgut's “copper cells.” The same expression pattern is observed with a synthetic minipromoter consisting only of four tandem metal response elements. From these and other experiments, we conclude that tissue specificity of metallothionein expression is a consequence, rather than a cause, of metal distribution in the organism. The bright orange luminescence of copper accumulated in copper cells of the midgut is severely reduced in the metallothionein gene family knockout, as well as in mutants of metal-responsive transcription factor 1 (MTF-1), the main regulator of metallothionein expression. This indicates that an in vivo metallothionein-copper complex forms the basis of this luminescence. Strikingly, metallothionein mutants show an increased, MTF-1-dependent induction of metallothionein promoters in response to copper, cadmium, silver, zinc, and mercury. We conclude that free metal, but not metallothionein-bound metal, triggers the activation of MTF-1 and that

METALLOTHIONEIN GENE TRANSCRIPTION AS AN INDICATOR OF METAL EXPOSURE IN FATHEAD MINNOWS

EPA Science Inventory

Metallothionein is a cysteine rich, low molecular weight, metal binding protein. Basal levels of endogenous metallothioneins (MT) have been reported in all eucaryotes. MT has been shown to play an essential role in regulating physiological requirements of essential metals such a...

Cartilage constructs engineered from chondrocytes overexpressing IGF-I improve the repair of osteochondral defects in a rabbit model.

PubMed

Madry, H; Kaul, G; Zurakowski, D; Vunjak-Novakovic, G; Cucchiarini, M

2013-04-16

Tissue engineering combined with gene therapy is a promising approach for promoting articular cartilage repair. Here, we tested the hypothesis that engineered cartilage with chondrocytes overexpressing a human insulin-like growth factor I (IGF-I) gene can enhance the repair of osteochondral defects, in a manner dependent on the duration of cultivation. Genetically modified chondrocytes were cultured on biodegradable polyglycolic acid scaffolds in dynamic flow rotating bioreactors for either 10 or 28 d. The resulting cartilaginous constructs were implanted into osteochondral defects in rabbit knee joints. After 28 weeks of in vivo implantation, immunoreactivity to ß-gal was detectable in the repair tissue of defects that received lacZ constructs. Engineered cartilaginous constructs based on IGF-I-overexpressing chondrocytes markedly improved osteochondral repair compared with control (lacZ) constructs. Moreover, IGF-I constructs cultivated for 28 d in vitro significantly promoted osteochondral repair vis-à-vis similar constructs cultivated for 10 d, leading to significantly decreased osteoarthritic changes in the cartilage adjacent to the defects. Hence, the combination of spatially defined overexpression of human IGF-I within a tissue-engineered construct and prolonged bioreactor cultivation resulted in most enhanced articular cartilage repair and reduction of osteoarthritic changes in the cartilage adjacent to the defect. Such genetically enhanced tissue engineering provides a versatile tool to evaluate potential therapeutic genes in vivo and to improve our comprehension of the development of the repair tissue within articular cartilage defects. Insights gained with additional exploration using this model may lead to more effective treatment options for acute cartilage defects.

Overexpression of a glyoxalase gene, OsGly I, improves abiotic stress tolerance and grain yield in rice (Oryza sativa L.).

PubMed

Zeng, Zhengming; Xiong, Fangjie; Yu, Xiaohong; Gong, Xiaoping; Luo, Juntao; Jiang, Yudong; Kuang, Haochi; Gao, Bijun; Niu, Xiangli; Liu, Yongsheng

2016-12-01

Glyoxalase I (Gly I) is a component of the glyoxalase system which is involved in the detoxification of methylglyoxal, a byproduct of glycolysis. In the present study, a gene of rice (Oryza sativa L., cv. Nipponbare) encoding Gly I was cloned and characterized. The quantitative real-time PCR analysis indicated that rice Gly I (OsGly I) was ubiquitously expressed in root, stem, leaf, leaf sheath and spikelet with varying abundance. OsGly I was markedly upregulated in response to NaCl, ZnCl 2 and mannitol in rice seedlings. For further functional investigation, OsGly I was overexpressed in rice using Agrobacterium-mediated transformation. Transgenic rice lines exhibited increased glyoxalase enzyme activity, decreased methylglyoxal level and improved tolerance to NaCl, ZnCl 2 and mannitol compared to wild-type plants. Enhancement of stress tolerance in transgenic lines was associated with reduction of malondialdehyde content which was derived from cellular lipid peroxidation. In addition, the OsGly I-overexpression transgenic plants performed higher seed setting rate and yield. Collectively, these results indicate the potential of bioengineering the Gly I gene in crops. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Yeast and Mammalian Metallothioneins Functionally Substitute for Yeast Copper-Zinc Superoxide Dismutase

NASA Astrophysics Data System (ADS)

Tamai, Katherine T.; Gralla, Edith B.; Ellerby, Lisa M.; Valentine, Joan S.; Thiele, Dennis J.

1993-09-01

Copper-zinc superoxide dismutase catalyzes the disproportionation of superoxide anion to hydrogen peroxide and dioxygen and is thought to play an important role in protecting cells from oxygen toxicity. Saccharomyces cerevisiae strains lacking copper-zinc superoxide dismutase, which is encoded by the SOD1 gene, are sensitive to oxidative stress and exhibit a variety of growth defects including hypersensitivity to dioxygen and to superoxide-generating drugs such as paraquat. We have found that in addition to these known phenotypes, SOD1-deletion strains fail to grow on agar containing the respiratory carbon source lactate. We demonstrate here that expression of the yeast or monkey metallothionein proteins in the presence of copper suppresses the lactate growth defect and some other phenotypes associated with SOD1-deletion strains, indicating that copper metallothioneins substitute for copper-zinc superoxide dismutase in vivo to protect cells from oxygen toxicity. Consistent with these results, we show that yeast metallothionein mRNA levels are dramatically elevated under conditions of oxidative stress. Furthermore, in vitro assays demonstrate that yeast metallothionein, purified or from whole-cell extracts, exhibits copper-dependent antioxidant activity. Taken together, these data suggest that both yeast and mammalian metallothioneins may play a direct role in the cellular defense against oxidative stress by functioning as antioxidants.

Unexpected Interactions of the Cyanobacterial Metallothionein SmtA with Uranium.

PubMed

Acharya, Celin; Blindauer, Claudia A

2016-02-15

Molecules for remediating or recovering uranium from contaminated environmental resources are of high current interest, with protein-based ligands coming into focus recently. Metallothioneins either bind or redox-silence a range of heavy metals, conferring protection against metal stress in many organisms. Here, we report that the cyanobacterial metallothionein SmtA competes with carbonate for uranyl binding, leading to formation of heterometallic (UO2)(n)Zn4SmtA species, without thiol oxidation, zinc loss, or compromising secondary or tertiary structure of SmtA. In turn, only metalated and folded SmtA species were found to be capable of uranyl binding. (1)H NMR studies and molecular modeling identified Glu34/Asp38 and Glu12/C-terminus as likely adventitious, but surprisingly strong, bidentate binding sites. While it is unlikely that these interactions correspond to an evolved biological function of this metallothionein, their occurrence may offer new possibilities for designing novel multipurpose bacterial metallothioneins with dual ability to sequester both soft metal ions including Cu(+), Zn(2+), Cd(2+), Hg(2+), and Pb(2+) and hard, high-oxidation state heavy metals such as U(VI). The concomitant protection from the chemical toxicity of uranium may be valuable for the development of bacterial strains for bio-remediation.

Shapes of Differential Pulse Voltammograms and Level of Metallothionein at Different Animal Species.

PubMed

Adam, Vojtech; Beklova, Miroslava; Pikula, Jiri; Hubalek, Jaromir; Trnkova, Libuse; Kizek, Rene

2007-10-19

Metallothioneins play a key role in maintaining homeostasis of essential metalsand in protecting of cells against metal toxicity as well as oxidative damaging. Exceptinghumans, blood levels of metallothionein have not yet been reported from any animalspecies. Blood plasma samples of 9 animal species were analysed by the adsorptive transferstripping technique to obtain species specific voltammograms. Quite distinct records wereobtained from the Takin (Budorcas taxicolor), while other interesting records were observedin samples from the European Bison (Bison bonasus bonasus) and the Red-eared Slider(Trachemys scripta elegans). To quantify metallothionein the catalytic peak Cat2 was used,well developed in the Domestic Fowl (Gallus gallus f. domestica) and showing a very lowsignal in the Red Deer (Cervus elaphus). The highest levels of metallothionein reachingover 20 μM were found in the Domestic Fowl. High levels of MT were also found in theBearded Dragon (Pogona vitticeps) and the Grey Wolf (Canis lupus lupus). The lowestvalues of about 1-3 μM were determined in the Red-eared Slider, Takin and Red Deer. Employing a simple electrochemical detection it was possible to examine variation in blood metallothionein in different species of vertebrates.

Overexpression of IGF-I in skeletal muscle of transgenic mice does not prevent unloading-induced atrophy

NASA Technical Reports Server (NTRS)

Criswell, D. S.; Booth, F. W.; DeMayo, F.; Schwartz, R. J.; Gordon, S. E.; Fiorotto, M. L.

1998-01-01

This study examined the association between local insulin-like growth factor I (IGF-I) overexpression and atrophy in skeletal muscle. We hypothesized that endogenous skeletal muscle IGF-I mRNA expression would decrease with hindlimb unloading (HU) in mice, and that transgenic mice overexpressing human IGF-I (hIGF-I) specifically in skeletal muscle would exhibit less atrophy after HU. Male transgenic mice and nontransgenic mice from the parent strain (FVB) were divided into four groups (n = 10/group): 1) transgenic, weight-bearing (IGF-I/WB); 2) transgenic, hindlimb unloaded (IGF-I/HU); 3) nontransgenic, weight-bearing (FVB/WB); and 4) nontransgenic, hindlimb unloaded (FVB/HU). HU groups were hindlimb unloaded for 14 days. Body mass was reduced (P < 0.05) after HU in both IGF-I (-9%) and FVB mice (-13%). Contrary to our hypothesis, we found that the relative abundance of mRNA for the endogenous rodent IGF-I (rIGF-I) was unaltered by HU in the gastrocnemius (GAST) muscle of wild-type FVB mice. High-level expression of hIGF-I peptide and mRNA was confirmed in the GAST and tibialis anterior (TA) muscles of the transgenic mice. Nevertheless, masses of the GAST and TA muscles were reduced (P < 0.05) in both FVB/HU and IGF-I/HU groups compared with FVB/WB and IGF-I/WB groups, respectively, and the percent atrophy in mass of these muscles did not differ between FVB and IGF-I mice. Therefore, skeletal muscle atrophy may not be associated with a reduction of endogenous rIGF-I mRNA level in 14-day HU mice. We conclude that high local expression of hIGF-I mRNA and peptide in skeletal muscle alone cannot attenuate unloading-induced atrophy of fast-twitch muscle in mice.

Cardiac I-1c overexpression with reengineered AAV improves cardiac function in swine ischemic heart failure.

PubMed

Ishikawa, Kiyotake; Fish, Kenneth M; Tilemann, Lisa; Rapti, Kleopatra; Aguero, Jaume; Santos-Gallego, Carlos G; Lee, Ahyoung; Karakikes, Ioannis; Xie, Chaoqin; Akar, Fadi G; Shimada, Yuichi J; Gwathmey, Judith K; Asokan, Aravind; McPhee, Scott; Samulski, Jade; Samulski, Richard Jude; Sigg, Daniel C; Weber, Thomas; Kranias, Evangelia G; Hajjar, Roger J

2014-12-01

Cardiac gene therapy has emerged as a promising option to treat advanced heart failure (HF). Advances in molecular biology and gene targeting approaches are offering further novel options for genetic manipulation of the cardiovascular system. The aim of this study was to improve cardiac function in chronic HF by overexpressing constitutively active inhibitor-1 (I-1c) using a novel cardiotropic vector generated by capsid reengineering of adeno-associated virus (BNP116). One month after a large anterior myocardial infarction, 20 Yorkshire pigs randomly received intracoronary injection of either high-dose BNP116.I-1c (1.0 × 10(13) vector genomes (vg), n = 7), low-dose BNP116.I-1c (3.0 × 10(12) vg, n = 7), or saline (n = 6). Compared to baseline, mean left ventricular ejection fraction increased by 5.7% in the high-dose group, and by 5.2% in the low-dose group, whereas it decreased by 7% in the saline group. Additionally, preload-recruitable stroke work obtained from pressure-volume analysis demonstrated significantly higher cardiac performance in the high-dose group. Likewise, other hemodynamic parameters, including stroke volume and contractility index indicated improved cardiac function after the I-1c gene transfer. Furthermore, BNP116 showed a favorable gene expression pattern for targeting the heart. In summary, I-1c overexpression using BNP116 improves cardiac function in a clinically relevant model of ischemic HF.

Cardiac I-1c Overexpression With Reengineered AAV Improves Cardiac Function in Swine Ischemic Heart Failure

PubMed Central

Ishikawa, Kiyotake; Fish, Kenneth M; Tilemann, Lisa; Rapti, Kleopatra; Aguero, Jaume; Santos-Gallego, Carlos G; Lee, Ahyoung; Karakikes, Ioannis; Xie, Chaoqin; Akar, Fadi G; Shimada, Yuichi J; Gwathmey, Judith K; Asokan, Aravind; McPhee, Scott; Samulski, Jade; Samulski, Richard Jude; Sigg, Daniel C; Weber, Thomas; Kranias, Evangelia G; Hajjar, Roger J

2014-01-01

Cardiac gene therapy has emerged as a promising option to treat advanced heart failure (HF). Advances in molecular biology and gene targeting approaches are offering further novel options for genetic manipulation of the cardiovascular system. The aim of this study was to improve cardiac function in chronic HF by overexpressing constitutively active inhibitor-1 (I-1c) using a novel cardiotropic vector generated by capsid reengineering of adeno-associated virus (BNP116). One month after a large anterior myocardial infarction, 20 Yorkshire pigs randomly received intracoronary injection of either high-dose BNP116.I-1c (1.0 × 1013 vector genomes (vg), n = 7), low-dose BNP116.I-1c (3.0 × 1012 vg, n = 7), or saline (n = 6). Compared to baseline, mean left ventricular ejection fraction increased by 5.7% in the high-dose group, and by 5.2% in the low-dose group, whereas it decreased by 7% in the saline group. Additionally, preload-recruitable stroke work obtained from pressure–volume analysis demonstrated significantly higher cardiac performance in the high-dose group. Likewise, other hemodynamic parameters, including stroke volume and contractility index indicated improved cardiac function after the I-1c gene transfer. Furthermore, BNP116 showed a favorable gene expression pattern for targeting the heart. In summary, I-1c overexpression using BNP116 improves cardiac function in a clinically relevant model of ischemic HF. PMID:25023328

Endothelium-specific GTP cyclohydrolase I overexpression accelerates refractory wound healing by suppressing oxidative stress in diabetes

PubMed Central

Tie, Lu; Li, Xue-Jun; Wang, Xian; Channon, Keith M.; Chen, Alex F.

2009-01-01

Refractory wound is a severe complication that leads to limb amputation in diabetes. Endothelial nitric oxide synthase (eNOS) plays a key role in normal wound repair but is uncoupled in streptozotocin (STZ)-induced type 1 diabetes because of reduced cofactor tetrahydrobiopterin (BH4). We tested the hypothesis that overexpression of GTP cyclohydrolase I (GTPCH I), the rate-limiting enzyme for de novo BH4 synthesis, retards NOS uncoupling and accelerates wound healing in STZ mice. Blood glucose levels were significantly increased in both male endothelium-specific GTPCH I transgenic mice (Tg-GCH; via a tie-2 promoter) and wild-type (WT) littermates 5 days after STZ regimen. A full-thickness excisional wound was created on mouse dorsal skin by a 4-mm punch biopsy. Wound closure was delayed in STZ mice, which was rescued in STZ Tg-GCH mice. Cutaneous BH4 level was significantly reduced in STZ mice vs. WT mice, which was maintained in STZ Tg-GCH mice. In STZ mice, constitutive NOS (cNOS) activity and nitrite levels were decreased compared with WT mice, paralleled by increased superoxide anion (O2−) level and inducible NOS (iNOS) activity. In STZ Tg-GCH mice, nitrite level and cNOS activity were potentiated and O2− level and iNOS activity were suppressed compared with STZ mice. Thus endothelium-specific BH4 overexpression accelerates wound healing in type 1 diabetic mice by enhancing cNOS activity and suppressing oxidative stress. PMID:19336662

The transcription factor MTF-1 is essential for basal and heavy metal-induced metallothionein gene expression.

PubMed

Heuchel, R; Radtke, F; Georgiev, O; Stark, G; Aguet, M; Schaffner, W

1994-06-15

We have described and cloned previously a factor (MTF-1) that binds specifically to heavy metal-responsive DNA sequence elements in the enhancer/promoter region of metallothionein genes. MTF-1 is a protein of 72.5 kDa that contains six zinc fingers and multiple domains for transcriptional activation. Here we report the disruption of both alleles of the MTF-1 gene in mouse embryonic stem cells by homologous recombination. The resulting null mutant cell line fails to produce detectable amounts of MTF-1. Moreover, due to the loss of MTF-1, the endogenous metallothionein I and II genes are silent, indicating that MTF-1 is required for both their basal and zinc-induced transcription. In addition to zinc, other heavy metals, including cadmium, copper, nickel and lead, also fail to activate metal-responsive promoters in null mutant cells. However, cotransfection of an MTF-1 expression vector and metal-responsive reporter genes yields strong basal transcription that can be further boosted by zinc treatment of cells. These results demonstrate that MTF-1 is essential for metallothionein gene regulation. Finally, we present evidence that MTF-1 itself is a zinc sensor, which exhibits increased DNA binding activity upon zinc treatment.

Partial purification, characterization and translation in vitro of rat liver metallothionein messenger ribonucleic acid.

PubMed Central

Andersen, R D; Weser, U

1978-01-01

Poly(A)+ (polyadenylated) mRNA coding for metallothioneins was purified 13-fold from rat liver polyribosomes and was identified by its ability to direct the biosynthesis of these proteins in a wheat-germ cell-free system. The carboxymethylated products of the protein-synthesizing system in vitro were analysed with sodium dodecyl sulphate/20% polyacrylamide-gel electrophoresis. The labelled compounds [3H]serine and [35S]cysteine were incorporated at high specific radioactivity into proteins that co-migrated with authentic metallothioneins. No [3H]leucine incorporation was found, in agreement with the amino acid composition of the metallothioneins. Metallothionein mRNA had a sedimentation coefficient of 9 S and carried a maximum of four ribosomes. At 5 h after a subcutaneous injection of ZnCl2 or CdCl2 (10 mumol/kg body wt.), the amount of this mRNA increased approx. 2- and 4-fold respectively, on the basis of translation in vitro. The increase in metallothionein mRNA (defined by translation in the wheat-germ system) was transient and, after CdCl2 treatment, fell back to control values by 17 h. Metallothioneins constituted a maximum of 0.8% of the total protein products synthesized in the wheat-germ system by total mRNA isolated from rat liver after CdCl2 treatment. Images Fig. 5. Fig. 6. PMID:743237

Shapes of Differential Pulse Voltammograms and Level of Metallothionein at Different Animal Species

PubMed Central

Adam, Vojtech; Beklova, Miroslava; Pikula, Jiri; Hubalek, Jaromir; Trnkova, Libuse; Kizek, Rene

2007-01-01

Metallothioneins play a key role in maintaining homeostasis of essential metals and in protecting of cells against metal toxicity as well as oxidative damaging. Excepting humans, blood levels of metallothionein have not yet been reported from any animal species. Blood plasma samples of 9 animal species were analysed by the adsorptive transfer stripping technique to obtain species specific voltammograms. Quite distinct records were obtained from the Takin (Budorcas taxicolor), while other interesting records were observed in samples from the European Bison (Bison bonasus bonasus) and the Red-eared Slider (Trachemys scripta elegans). To quantify metallothionein the catalytic peak Cat2 was used, well developed in the Domestic Fowl (Gallus gallus f. domestica) and showing a very low signal in the Red Deer (Cervus elaphus). The highest levels of metallothionein reaching over 20 µM were found in the Domestic Fowl. High levels of MT were also found in the Bearded Dragon (Pogona vitticeps) and the Grey Wolf (Canis lupus lupus). The lowest values of about 1-3 µM were determined in the Red-eared Slider, Takin and Red Deer. Employing a simple electrochemical detection it was possible to examine variation in blood metallothionein in different species of vertebrates. PMID:28903235

Neurobehavioral changes and alteration of gene expression in the brains of metallothionein-I/II null mice exposed to low levels of mercury vapor during postnatal development.

PubMed

Yoshida, Minoru; Honda, Masako; Watanabe, Chiho; Satoh, Masahiko; Yasutake, Akira

2011-10-01

This study examined the neurobehavioral changes and alteration in gene expression in the brains of metallothionein (MT)-I/II null mice exposed to low-levels of mercury vapor (Hg(0)) during postnatal development. MT-I/II null and wild-type mice were repeatedly exposed to Hg(0) at 0.030 mg/m(3) (range: 0.023-0.043 mg/m(3)), which was similar to the current threshold value (TLV), for 6 hr per day until the 20th day postpartum. The behavioral effects were evaluated with locomotor activity in the open field (OPF), learning ability in the passive avoidance response (PA) and spatial learning ability in the Morris water maze (MM) at 12 weeks of age. Hg(0)-exposed MT-I/II null mice showed a significant decrease in total locomotor activity in females, though learning ability and spatial learning ability were not affected. Immediately after Hg(0) exposure, mercury concentrations in the brain did not exceed 0.5 µg/g in any animals. Hg(0) exposure resulted in significant alterations in gene expression in the brains of both strains using DNA microarray analysis. The number of altered genes in MT-I/II null mice was higher than that in wild-type mice and calcium-calmodulin kinase II (Camk2a) involved in learning and memory in down-regulated genes was detected. These results provide useful information to elucidate the development of behavioral toxicity following low-level exposure to Hg(0).

Metallothionein provides zinc-mediated protective effects against methamphetamine toxicity in SK-N-SH cells.

PubMed

Ajjimaporn, Amornpan; Swinscoe, John; Shavali, Shaik; Govitrapong, Piyarat; Ebadi, Manuchair

2005-11-30

Methamphetamine (METH) is a drug of abuse and neurotoxin that induces Parkinson's-like pathology after chronic usage by targeting dopaminergic neurons. Elucidation of the intracellular mechanisms that underlie METH-induced dopaminergic neuron toxicity may help in understanding the mechanism by which neurons die in Parkinson's disease. In the present study, we examined the role of reactive oxygen species (ROS) in the METH-induced death of human dopaminergic SK-N-SH cells and further assessed the neuroprotective effects of zinc and metallothionein (MT) against METH-induced toxicity in culture. METH significantly increased the production of reactive oxygen species, decreased intracellular ATP levels and reduced the cell viability. Pre-treatment with zinc markedly prevented the loss of cell viability caused by METH treatment. Zinc pre-treatment mainly increased the expression of metallothionein and prevented the generation of reactive oxygen species and ATP depletion caused by METH. Chelation of zinc by CaEDTA caused a significant decrease in MT expression and loss of protective effects of MT against METH toxicity. These results suggest that zinc-induced MT expression protects dopaminergic neurons via preventing the accumulation of toxic reactive oxygen species and halting the decrease in ATP levels. Furthermore, MT may prevent the loss of mitochondrial functions caused by neurotoxins. In conclusion, our study suggests that MT, a potent scavenger of free radicals is neuroprotective against dopaminergic toxicity in conditions such as drug of abuse and in Parkinson's disease.

Overexpression of Dyrk1A, a Down Syndrome Candidate, Decreases Excitability and Impairs Gamma Oscillations in the Prefrontal Cortex.

PubMed

Ruiz-Mejias, Marcel; Martinez de Lagran, Maria; Mattia, Maurizio; Castano-Prat, Patricia; Perez-Mendez, Lorena; Ciria-Suarez, Laura; Gener, Thomas; Sancristobal, Belen; García-Ojalvo, Jordi; Gruart, Agnès; Delgado-García, José M; Sanchez-Vives, Maria V; Dierssen, Mara

2016-03-30

The dual-specificity tyrosine phosphorylation-regulated kinase DYRK1A is a serine/threonine kinase involved in neuronal differentiation and synaptic plasticity and a major candidate of Down syndrome brain alterations and cognitive deficits. DYRK1A is strongly expressed in the cerebral cortex, and its overexpression leads to defective cortical pyramidal cell morphology, synaptic plasticity deficits, and altered excitation/inhibition balance. These previous observations, however, do not allow predicting how the behavior of the prefrontal cortex (PFC) network and the resulting properties of its emergent activity are affected. Here, we integrate functional, anatomical, and computational data describing the prefrontal network alterations in transgenic mice overexpressingDyrk1A(TgDyrk1A). Usingin vivoextracellular recordings, we show decreased firing rate and gamma frequency power in the prefrontal network of anesthetized and awakeTgDyrk1Amice. Immunohistochemical analysis identified a selective reduction of vesicular GABA transporter punctae on parvalbumin positive neurons, without changes in the number of cortical GABAergic neurons in the PFC ofTgDyrk1Amice, which suggests that selective disinhibition of parvalbumin interneurons would result in an overinhibited functional network. Using a conductance-based computational model, we quantitatively demonstrate that this alteration could explain the observed functional deficits including decreased gamma power and firing rate. Our results suggest that dysfunction of cortical fast-spiking interneurons might be central to the pathophysiology of Down syndrome. DYRK1Ais a major candidate gene in Down syndrome. Its overexpression results into altered cognitive abilities, explained by defective cortical microarchitecture and excitation/inhibition imbalance. An open question is how these deficits impact the functionality of the prefrontal cortex network. Combining functional, anatomical, and computational approaches, we identified

[Enhanced nisin production by overexpression of nisin immunity gene nisI in the nisin-producing strain].

PubMed

Hu, Hongmei; Jiang, Like; Lin, Yuheng; Huan, Liandong; Zhong, Jin

2010-10-01

Our aim was to enhance nisin production by overexpression of nisin immunity gene nisI in nisin-producing strains. Nisin immunity gene nisI with a strong promoter P59 was cloned into vector pHJ201 and introduced into Lacotococcus lactis NZ9800, resulting in a recombinant strain L. lactis NZ9800/pHMI. Then the differences between the recombinant strain and the control strain L. lactis NZ9800/pHJ201 were analyzed in several aspects, including their growth curves, nisin resistance level and antibacterial activity against indicator strain Microccus flavus NCIB 8166. The overexpression of nisI had no significant difference in growth rate between recombinant strain and contrast strain. However, it promoted recombinant strain tolerance 25% higer nisin resistance level and stronger antibacterial activity against M. flavus NCIB 8166, which was increased by 32% and 25% when fermented for 6 and 8 hours, respectively. These results indicated that overexpression of nisI gene in the nisin producing strain can effectively enhance nisin resistence level and thus improve nisin production.

Characterization of mercury bioremediation by transgenic bacteria expressing metallothionein and polyphosphate kinase.

PubMed

Ruiz, Oscar N; Alvarez, Derry; Gonzalez-Ruiz, Gloriene; Torres, Cesar

2011-08-12

The use of transgenic bacteria has been proposed as a suitable alternative for mercury remediation. Ideally, mercury would be sequestered by metal-scavenging agents inside transgenic bacteria for subsequent retrieval. So far, this approach has produced limited protection and accumulation. We report here the development of a transgenic system that effectively expresses metallothionein (mt-1) and polyphosphate kinase (ppk) genes in bacteria in order to provide high mercury resistance and accumulation. In this study, bacterial transformation with transcriptional and translational enhanced vectors designed for the expression of metallothionein and polyphosphate kinase provided high transgene transcript levels independent of the gene being expressed. Expression of polyphosphate kinase and metallothionein in transgenic bacteria provided high resistance to mercury, up to 80 μM and 120 μM, respectively. Here we show for the first time that metallothionein can be efficiently expressed in bacteria without being fused to a carrier protein to enhance mercury bioremediation. Cold vapor atomic absorption spectrometry analyzes revealed that the mt-1 transgenic bacteria accumulated up to 100.2 ± 17.6 μM of mercury from media containing 120 μM Hg. The extent of mercury remediation was such that the contaminated media remediated by the mt-1 transgenic bacteria supported the growth of untransformed bacteria. Cell aggregation, precipitation and color changes were visually observed in mt-1 and ppk transgenic bacteria when these cells were grown in high mercury concentrations. The transgenic bacterial system described in this study presents a viable technology for mercury bioremediation from liquid matrices because it provides high mercury resistance and accumulation while inhibiting elemental mercury volatilization. This is the first report that shows that metallothionein expression provides mercury resistance and accumulation in recombinant bacteria. The high accumulation of

Characterization of mercury bioremediation by transgenic bacteria expressing metallothionein and polyphosphate kinase

PubMed Central

2011-01-01

Background The use of transgenic bacteria has been proposed as a suitable alternative for mercury remediation. Ideally, mercury would be sequestered by metal-scavenging agents inside transgenic bacteria for subsequent retrieval. So far, this approach has produced limited protection and accumulation. We report here the development of a transgenic system that effectively expresses metallothionein (mt-1) and polyphosphate kinase (ppk) genes in bacteria in order to provide high mercury resistance and accumulation. Results In this study, bacterial transformation with transcriptional and translational enhanced vectors designed for the expression of metallothionein and polyphosphate kinase provided high transgene transcript levels independent of the gene being expressed. Expression of polyphosphate kinase and metallothionein in transgenic bacteria provided high resistance to mercury, up to 80 μM and 120 μM, respectively. Here we show for the first time that metallothionein can be efficiently expressed in bacteria without being fused to a carrier protein to enhance mercury bioremediation. Cold vapor atomic absorption spectrometry analyzes revealed that the mt-1 transgenic bacteria accumulated up to 100.2 ± 17.6 μM of mercury from media containing 120 μM Hg. The extent of mercury remediation was such that the contaminated media remediated by the mt-1 transgenic bacteria supported the growth of untransformed bacteria. Cell aggregation, precipitation and color changes were visually observed in mt-1 and ppk transgenic bacteria when these cells were grown in high mercury concentrations. Conclusion The transgenic bacterial system described in this study presents a viable technology for mercury bioremediation from liquid matrices because it provides high mercury resistance and accumulation while inhibiting elemental mercury volatilization. This is the first report that shows that metallothionein expression provides mercury resistance and accumulation in recombinant bacteria

The unique C- and N-terminal sequences of Metallothionein isoform 3 mediate growth inhibition and Vectorial active transport in MCF-7 cells.

PubMed

Voels, Brent; Wang, Liping; Sens, Donald A; Garrett, Scott H; Zhang, Ke; Somji, Seema

2017-05-25

The 3rd isoform of the metallothionein (MT3) gene family has been shown to be overexpressed in most ductal breast cancers. A previous study has shown that the stable transfection of MCF-7 cells with the MT3 gene inhibits cell growth. The goal of the present study was to determine the role of the unique C-terminal and N-terminal sequences of MT3 on phenotypic properties and gene expression profiles of MCF-7 cells. MCF-7 cells were transfected with various metallothionein gene constructs which contain the insertion or the removal of the unique MT3 C- and N-terminal domains. Global gene expression analysis was performed on the MCF-7 cells containing the various constructs and the expression of the unique C- and N- terminal domains of MT3 was correlated to phenotypic properties of the cells. The results of the present study demonstrate that the C-terminal sequence of MT3, in the absence of the N-terminal sequence, induces dome formation in MCF-7 cells, which in cell cultures is the phenotypic manifestation of a cell's ability to perform vectorial active transport. Global gene expression analysis demonstrated that the increased expression of the GAGE gene family correlated with dome formation. Expression of the C-terminal domain induced GAGE gene expression, whereas the N-terminal domain inhibited GAGE gene expression and that the effect of the N-terminal domain inhibition was dominant over the C-terminal domain of MT3. Transfection with the metallothionein 1E gene increased the expression of GAGE genes. In addition, both the C- and the N-terminal sequences of the MT3 gene had growth inhibitory properties, which correlated to an increased expression of the interferon alpha-inducible protein 6. Our study shows that the C-terminal domain of MT3 confers dome formation in MCF-7 cells and the presence of this domain induces expression of the GAGE family of genes. The differential effects of MT3 and metallothionein 1E on the expression of GAGE genes suggests unique roles of

Metallothionein induction in aquatic oligochaete tubifex tubifex exposed to herbicide isoproturon.

PubMed

Mosleh, Y Y; Paris-Palacios, S; Arnoult, F; Couderchet, M; Biagianti-Risbourg, S; Vernet, G

2004-02-01

Metallothioneins (MTs) are low-molecular-weight proteins mainly involved in metal ion detoxification. Recently it has been demonstrated that MTs participate in several cellular functions such as regulation of growth and antioxidative defenses. Moreover, pesticides can induce their synthesis. The aim of the current work was to determine the effects of isoproturon, either pure or formulated as Matin (suspension containing an isoproturon concentration of 500 g. L(-1)), on the metallothionein and total protein contents of the aquatic worm Tubifex tubifex. MT levels in exposed worms increased significantly after 7 and 15 days of exposure to a concentration of the herbicide of 50 mg. L(-1). Isoproturon reduced the metal (Cu, Zn, and Cd) content of metallothioneins, and it also increased the total protein content of the worms. These results suggest that MT induction may not be considered a specific biomarker of metal exposure but that it can be used as a nonspecific biomarker of the effect of isoproturon effect in aquatic worms. Copyright 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 88-93, 2004.

Molecular control of copper homeostasis in filamentous fungi: increased expression of a metallothionein gene during aging of Podospora anserina.

PubMed

Averbeck, N B; Borghouts, C; Hamann, A; Specke, V; Osiewacz, H D

2001-01-01

The lifespan of the ascomycete Podospora anserina was previously demonstrated to be significantly increased in a copper-uptake mutant, suggesting that copper is a potential stressor involved in degenerative processes. In order to determine whether changes in copper stress occur in the cells during normal aging of cultures, we cloned and characterized a gene coding for a component of the molecular machinery involved in the control of copper homeostasis. This gene, PaMt1, is a single-copy gene that encodes a metallothionein of 26 amino acids. The coding sequence of PaMt1 is interrupted by a single intron. The deduced amino acid sequence shows a high degree of sequence identity to metallothioneins of the filamentous ascomycete Neurospora crassa and the basidiomycete Agaricus bisporus, and to the N-terminal portion of mammalian metallothioneins. Levels of PaMt1 transcript increase in response to elevated amounts of copper in the growth medium and during aging of wild-type cultures. In contrast, in the long-lived mutant grisea, transcript levels first increase but then decrease again. The ability of wild-type cultures to respond to exogenous copper stress via the induction of PaMt1 transcription is not affected as they grow older.

Effects of cadmium and zinc on solar-simulated light-irradiated cells: potential role of zinc-metallothionein in zinc-induced genoprotection.

PubMed

Jourdan, Eric; Emonet-Piccardi, Nathalie; Didier, Christine; Beani, Jean-Claude; Favier, Alain; Richard, Marie-Jeanne

2002-09-15

Zinc is an essential oligoelement for cell growth and cell survival and has been demonstrated to protect cells from oxidative stress induced by UVA or from genotoxic stress due to UVB. In a recent work we demonstrated that the antioxidant role of zinc could be related to its ability to induce metallothioneins (MTs). In this study we identified the mechanism of zinc protection against solar-simulated light (SSL) injury. Cultured human keratinocytes (HaCaT) were used to examine MTs expression and localization in response to solar-simulated radiation. We found translocation to the nucleus, with overexpression of MTs in irradiated cells, a novel observation. The genoprotective effect of zinc was dependent on time and protein synthesis. DNA damage was significantly decreased after 48 h of ZnCl(2) (100 microM) treatment and is inhibited by actinomycin D. ZnCl(2) treatment (100 microM) led to an intense induction, redistribution, and accumulation of MT in the nucleus of irradiated cells. MT expression correlated with the time period of ZnCl(2) treatment. CdCl(2), a potent MT inducer, did not show any genoprotection, although the MTs were expressed in the nucleus. Overall our findings demonstrate that MTs could be a good candidate for explaining the genoprotection mediated by zinc on irradiated cells.

Evidence for nuclear interaction of a cytoskeleton protein (OsIFL) with metallothionein and its role in salinity stress tolerance

PubMed Central

Soda, Neelam; Sharan, Ashutosh; Gupta, Brijesh K.; Singla-Pareek, Sneh L.; Pareek, Ashwani

2016-01-01

Soil salinity is being perceived as a major threat to agriculture. Plant breeders and molecular biologist are putting their best efforts to raise salt-tolerant crops. The discovery of the Saltol QTL, a major QTL localized on chromosome I, responsible for salt tolerance at seedling stage in rice has given new hopes for raising salinity tolerant rice genotypes. In the present study, we have functionally characterized a Saltol QTL localized cytoskeletal protein, intermediate filament like protein (OsIFL), of rice. Studies related to intermediate filaments are emerging in plants, especially with respect to their involvement in abiotic stress response. Our investigations clearly establish that the heterologous expression of OsIFL in three diverse organisms (bacteria, yeast and tobacco) provides survival advantage towards diverse abiotic stresses. Screening of rice cDNA library revealed OsIFL to be strongly interacting with metallothionein protein. Bimolecular fluorescence complementation assay further confirmed this interaction to be occurring inside the nucleus. Overexpression of OsIFL in transgenic tobacco plants conferred salinity stress tolerance by maintaining favourable K+/Na+ ratio and thus showed protection from salinity stress induced ion toxicity. This study provides the first evidence for the involvement of a cytoskeletal protein in salinity stress tolerance in diverse organisms. PMID:27708383

Phase I Trial of Anti-MET Monoclonal Antibody in MET-Overexpressed Refractory Cancer.

PubMed

Lee, Jeeyun; Kim, Seung Tae; Park, Sungju; Lee, Sujin; Park, Se Hoon; Park, Joon Oh; Lim, Ho Yeong; Ahn, Hongmo; Bok, Haesook; Kim, Kyoung-Mee; Ahn, Myung Ju; Kang, Won Ki; Park, Young Suk

2018-06-01

Samsung Advance Institute of Technology-301 (SAIT301) is a human immunoglobulin G2 antibody that can specifically target mesenchymal epithelial transition factor (c-MET). This novel antibody has higher priority over hepatocyte growth factors when binding to the Sema domain of c-MET and accelerates the internalization and degradation of c-MET, proving its powerful antitumor activities in intra- as well as extracellular areas. SAIT301 was administered intravenously once every 3 weeks in c-MET overexpressed solid tumor patients, focusing on metastatic colorectal cancer (CRC) according to common clinical phase I criteria. Dose escalation was performed according to a modified Fibonacci design, following the conventional 3+3 design. The purpose of this phase I study was to assess the safety profile, to establish the recommended dose for clinical phase II studies and to assess potential anticancer activity of the compound. Sixteen patients with a median age of 56 (range, 39-69) years were enrolled in the study. The most common adverse events were decreased appetite (50.0%), hypophosphatemia, fatigue and dizziness (25.0%, respectively), and diarrhea, blood alkaline phosphatase increased and dyspnea (18.8%, respectively). For tumor response, no patients achieved complete response. One (9.1%) CRC patient had a partial response in the 1.23 mg/kg group, 4 (36.4%) patients achieved stable disease (2 in the 0.41 mg/kg group, 2 in the 1.23 mg/kg group, 0 in the 3.69 mg/kg group, and 1 in the 8.61 mg/kg group). Because of the increase in dose-limiting toxicities (DLTs) at 8.61 mg/kg, the 3.69 mg/kg dose was considered the maximum tolerated dose and selected for further assessment in phase II. We successfully completed a phase I trial with MET antibody in a MET-overexpressed patient population focusing on CRC, and found that the DLTs were alkaline phosphatase elevation or hypophosphatemia. The recommended dose of SAIT301 for phase II is the dose of 3.69 mg/kg. Copyright © 2018

In vivo examination of (188)Re(I)-tricarbonyl-labeled trastuzumab to target HER2-overexpressing breast cancer.

PubMed

Chen, Kuo-Ting; Lee, Te-Wei; Lo, Jem-Mau

2009-05-01

Trastuzumab (Herceptin), a humanized IgG1 monoclonal antibody directed against the extracellular domain of the HER2 protein, acts as an immunotherapeutic agent for HER2-overexpressing human breast cancers. Radiolabeled trastuzumab with beta- or alpha emitters can be used as radioimmunotherapeutic agent for the similar purpose but with additional radiation effect. In this study, trastuzumab was labeled with (188)Re for radioimmunotherapy of HER2/neu-positive breast cancer. (188)Re(I)-tricarbonyl ion, [(188)Re(OH(2))(3)(CO)(3)](+), was employed as a precursor for directly labeling the monoclonal antibody with (188)Re. The immunoreactivity of (188)Re(I)-trastuzumab was estimated by competition receptor-binding assay using HER2/neu-overexpressive BT-474 human breast cancer cells. The localization properties of (188)Re(I)-trastuzumab within both tumor and normal tissues of athymic mice bearing BT-474 human breast cancer xenografts (HER2/neu-overexpressive) and similar mice bearing MCF-7 human breast cancer xenografts (HER2/neu-low expressive) were investigated. When incubated with human serum albumin and histidine at 25 degrees C, (188)Re(I)-trastuzumab was found to be stable within 24 h. The IC(50) of (188)Re(I)-trastuzumab was found to be 22.63+/-4.57 nM. (188)Re(I)-trastuzumab was shown to accumulate specifically in BT-474 tumor tissue in in vivo biodistribution studies. By microSPECT/CT, the image of (188)Re localized BT-474 tumor was clearly visualized within 24 h. In contrast, (188)Re(I)-trastuzumab uptake in HER2-low-expressing MCF-7 tumor was minimal, and the (188)Re image at the localization of the tumor was dim. These results reveal that (188)Re(I)-trastuzumab could be an appropriate radioimmunotherapeutic agent for the treatment of HER2/neu-overexpressing cancers.

Dietary cadmium and benzo(a)pyrene increased intestinal metallothionein expression in the fish Fundulus heteroclitus

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

Roesijadi, Guritno; Rezvankhah, Saeid; Perez-Matus, Alejandro

2008-10-17

To test the effect of dietary exposure to cadmium and benzo(a)pyrene on induction of metallothionein mRNA in the Fundulus heteroclitus, fish were individually fed a pelletized gel food containing cadmium, benzo(a)pyrene, or a combination of the two over a period of seven days, then analyzed for relative levels of metallothionein mRNA in the intestine, liver, and gill using real-time RT-qPCR. An initial experiment with only cadmium exposure showed an apparent 10-fold induction in the intestine, but no induction in liver or gill. Ingestion of contaminated pellets varied in individual fish, and because it was possible to monitor individual ingestion ratesmore » with our method, individual cadmium doses were estimated from the amount of ingested cadmium. When the levels of metallothionein mRNA were related to the dose to each fish, a linear dose-response relationship was observed for the intestine, but not the other organs, which showed no induction. In a second experiment, dose was controlled by placing the entire daily cadmium dose into a single contaminated pellet that was fed first (thereby, effectively controlling the effect of variable ingestion rates), and the interaction between cadmium and benzo(a)pyrene was also investigated. The intestine was again the primary organ for metallothionein induction by cadmium, with a 20-fold increase in metallothionein mRNA over control levels. When benzo(a)pyrene was administered together with cadmium, induction of metallothionein was potentiated by the presence of benzo(a)pyrene, with the main effect seen in the intestine, where already high levels of induction by cadmium alone increased by 1.74-fold when benzo(a)pyrene was present.« less

SIRT1 overexpression decreases cisplatin-induced acetylation of NF-{kappa}B p65 subunit and cytotoxicity in renal proximal tubule cells

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

Jung, Yu Jin; Lee, Jung Eun; Lee, Ae Sin

2012-03-09

Highlights: Black-Right-Pointing-Pointer Cisplatin increases acetylation of NF-{kappa}B p65 subunit in HK2 cells. Black-Right-Pointing-Pointer SIRT1 overexpression decreases cisplatin-induced p65 acetylation and -cytotoxicity. Black-Right-Pointing-Pointer Resveratrol decreased cisplatin-induced cell viability through deacetylation of p65. -- Abstract: As the increased acetylation of p65 is linked to nuclear factor-{kappa}B (NF-{kappa}B) activation, the regulation of p65 acetylation can be a potential target for the treatment of inflammatory injury. Cisplatin-induced nephrotoxicity is an important issue in chemotherapy of cancer patients. SIRT1, nicotinamide adenine dinucleotide (NAD{sup +})-dependent protein deacetylase, has been implicated in a variety of cellular processes such as inflammatory injury and the control of multidrug resistancemore » in cancer. However, there is no report on the effect of SIRT1 overexpression on cisplatin-induced acetylation of p65 subunit of NF-{kappa}B and cell injury. To investigate the effect of SIRT1 in on cisplatin-induced acetylation of p65 subunit of NF-{kappa}B and cell injury, HK2 cells were exposed with SIRT1 overexpression, LacZ adenovirus or dominant negative adenovirus after treatment with cisplatin. While protein expression of SIRT1 was decreased by cisplatin treatment compared with control buffer treatment, acetylation of NF-{kappa}B p65 subunit was significantly increased after treatment with cisplatin. Overexpression of SIRT1 ameliorated the increased acetylation of p65 of NF-{kappa}B during cisplatin treatment and cisplatin-induced cytotoxicity. Further, treatment of cisplatin-treated HK2 cells with resveratrol, a SIRT1 activator, also decreased acetylation of NF-{kappa}B p65 subunit and cisplatin-induced increase of the cell viability in HK2 cells. Our findings suggests that the regulation of acetylation of p65 of NF-{kappa}B through SIRT1 can be a possible target to attenuate cisplatin-induced renal cell damage.« less

Lipopolysaccharide-induced overproduction of nitric oxide and overexpression of iNOS and interleukin-1β proteins in zinc-deficient rats.

PubMed

Miyazaki, Takashi; Takenaka, Tsuneo; Inoue, Tsutomu; Sato, Makiko; Miyajima, Yuka; Nodera, Makoto; Hanyu, Mayuko; Ohno, Yoichi; Shibazaki, Satomi; Suzuki, Hiromichi

2012-03-01

Zinc deficiency leads to decreased cellular immune responses. The overproduction of nitrogen species derived from inducible nitric oxide synthase (iNOS), its enzyme, and interleukine-1 beta (IL-1β), and inflammatory cytokine have been implicated in immune responses. The goal of this study was to investigate the effects of lipopolysaccharide (LPS)-induced changes in NO metabolites, iNOS, and IL-1β protein expression in the lungs of zinc-deficient rats. Male Sprague-Dawley rats (body weight, 100 g) were divided into two groups and were fed either a zinc-deficient diet (ZnD) or a zinc-containing diet (Cont). After 4 weeks on these diets, rats received a 10-mg/kg dose of LPS injected via the tail vein and were then maintained for an additional 72 h. To determine total NO concentrations in the blood, serum zinc concentration, iNOS protein expression, IL-1β, and iNOS immunohistochemistry, blood and lung samples were obtained at pre-LPS injection, 5, 24, and 72 h after injection. Total NO levels were significantly increased at 5, at 24, and at 72 h after LPS injection compared with pre-LPS injection level in ZnD group; significant changes in total NO levels was elevated at 5 h from at pre-LPS level but not significant changes from basal level at 24 and 72 h in the control group. Based on western blot analyses and immunohistochemistry, clear bands indicating iNOS and IL-1β protein expression and iNOS antibody-stained inflammatory cells were detected at 5 and 24 h in the ZnD group and 5 h in the Cont group, not observed at 24 and 72 h in the control group. These results suggest that zinc deficiency induces overexpression of iNOS and IL-1β proteins from inflammatory cells around the alveolar blood vessels, resulting in overproduction of total NO and persisted inflammatory response in the zinc-deficient rat lung. Taken together, overexpression of LPS-induced iNOS, overproduction of iNOS-derived NO, and overexpression of IL-1β may induce nitrosative and oxidative

Let-7i attenuates human brain microvascular endothelial cell damage in oxygen glucose deprivation model by decreasing toll-like receptor 4 expression.

PubMed

Xiang, Wei; Tian, Canhui; Peng, Shunli; Zhou, Liang; Pan, Suyue; Deng, Zhen

2017-11-04

The let-7 family of microRNAs (miRNAs) plays an important role on endothelial cell function. However, there have been few studies on their role under ischemic conditions. In this study, we demonstrate that let-7i, belonging to the let-7 family, rescues human brain microvascular endothelial cells (HBMECs) in an oxygen-glucose deprivation (OGD) model. Our data show that the expression of let-7 family miRNAs was downregulated after OGD. Overexpression of let-7i significantly alleviated cell death and improved survival of OGD-treated HBMECs. Let-7i also protected permeability in an in vitro blood brain barrier (BBB) model. Further, let-7i downregulated the expression of toll-like receptor 4 (TLR4), an inflammation trigger. Moreover, overexpression of let-7i decreased matrix metallopeptidase 9 (MMP9) and inducible nitric oxide synthase (iNOS) expression under OGD. Upon silencing TLR4 expression in HBMECs, the anti-inflammatory effect of let-7i was abolished. Our research suggests that let-7i promotes OGD-induced inflammation via downregulating TLR4 expression. Copyright © 2017 Elsevier Inc. All rights reserved.

Cadium pathways during gestation and lactation in control vs. metallothionein 1,2-knockout mice.

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

Brako, E. E.; Wilson, A. K.; Jonah, M. M.

2003-01-01

Effects of metallothionein (MT) on cadmium absorption and transfer pathways during gestation and lactation in mice were investigated. Female 129/SvJ metallothionein-knockout (MT1,2KO) and metallothionein-normal (MTN) mice received drinking water containing trace amounts of {sup 109}CdCl{sub 2} (0.15 ng Cd/ml; 0.074 {mu}Ci {sup 109}Cd/ml). {sup 109}Cd and MT in maternal, fetal, and pup tissues were measured on gestation days 7, 14, and 17 and lactation day 11. In dams, MT influenced both the amount of {sup 109}Cd transferred from intestine into body (two- to three-fold higher in MT1,2KO than MTN dams) and tissue-specific {sup 109}Cd distribution (higher liver/kidney ratio in MT1,2KOmore » dams). Placental {sup 109}Cd concentrations in MT1,2KO dams were three- and seven-fold higher on gestation days 14 and 17, respectively, than in MTN dams. Fetal {sup 109}Cd levels were low in both mouse types, but at least 10-fold lower in MTN fetuses. MT had no effect on the amount of {sup 109}Cd transferred to pups via milk; furthermore, 85--90% of total pup {sup 109}Cd was recovered in gastrointestinal tracts of both types, despite high duodenal MT only in MTN pups. A relatively large percentage of milk-derived intestinal {sup 109}Cd was transferred to other pup tissues in both MT1,2KO and MTN pups (14 and 10%, respectively). These results demonstrate that specific sequestration of cadmium by both maternal and neonatal intestinal tract does not require MT. Although MT decreased oral cadmium transfer from intestine to body tissues at low cadmium exposure levels, MT did not play a major role in restricting transfer of cadmium from dam to fetus via placenta and to neonate via milk.« less

Comparison of minichromosome maintenance proteins (MCM-3, MCM-7) and metallothioneins (MT-I/II, MT-III) expression in relation to clinicopathological data in ovarian cancer.

PubMed

Kobierzycki, Christopher; Pula, Bartosz; Skiba, Mateusz; Jablonska, Karolina; Latkowski, Krzysztof; Zabel, Maciej; Nowak-Markwitz, Ewa; Spaczynski, Marek; Kedzia, Witold; Podhorska-Okolow, Marzena; Dziegiel, Piotr

2013-12-01

Despite great progress in the understanding of ovarian cancer biology, clinicopathological data (i.e. grade, stage, histological type and residual disease after surgery) seem to be the most important prognostic factors. The present study aimed to investigate the relationship between expression of minichromosome maintenance proteins (MCM-3, MCM-7), metallothioneins (MT-I/II, MT-III), and Ki-67 in 103 ovarian cancer cases, mostly of the serous histological type. Statistical analysis revealed strong positive correlations in the expression of MCM-3 vs. Ki-67 (r=0.492), MCM-7 vs. Ki-67 (r=0.651), and MCM-3 vs. MCM-7 (r=0.515) (all p<0.0001). The Kruskal-Wallis test showed an association of increased expression of MCM-3 and Ki-67 with increasing grade of histological malignancy (p=0.0011, p=0.029, respectively). Regarding clinical progression, cytoplasmic MT-I/II expression was significantly higher in more advanced disease stages (III+IV vs. I+II; p=0.0247). Due to the correlations shown here, the determination of MCM proteins as proliferation markers of ovarian cancer, should be strongly considered.

Dietary Supplementation of Blueberry Juice Enhances Hepatic Expression of Metallothionein and Attenuates Liver Fibrosis in Rats

PubMed Central

Wang, Yuping; Cheng, Mingliang; Zhang, Baofang; Nie, Fei; Jiang, Hongmei

2013-01-01

Aim To investigate the effect of blueberry juice intake on rat liver fibrosis and its influence on hepatic antioxidant defense. Methods Rabbiteye blueberry was used to prepare fresh juice to feed rats by daily gastric gavage. Dan-shao-hua-xian capsule (DSHX) was used as a positive control for liver fibrosis protection. Liver fibrosis was induced in male Sprague-Dawley rats by subcutaneous injection of CCl4 and feeding a high-lipid/low-protein diet for 8 weeks. Hepatic fibrosis was evaluated by Masson staining. The expression of α-smooth muscle actin (α-SMA) and collagen III (Col III) were determined by immunohistochemical techniques. The activities of superoxide dismutase (SOD) and malondialdehyde (MDA) in liver homogenates were determined. Metallothionein (MT) expression was detected by real-time RT-PCR and immunohistochemical techniques. Results Blueberry juice consumption significantly attenuates CCl4-induced rat hepatic fibrosis, which was associated with elevated expression of metallothionein (MT), increased SOD activity, reduced oxidative stress, and decreased levels of α-SMA and Col III in the liver. Conclusion Our study suggests that dietary supplementation of blueberry juice can augment antioxidative capability of the liver presumably via stimulating MT expression and SOD activity, which in turn promotes HSC inactivation and thus decreases extracellular matrix collagen accumulation in the liver, and thereby alleviating hepatic fibrosis. PMID:23554912

A decrease in ubiquitination and resulting prolonged life-span of KIT underlies the KIT overexpression-mediated imatinib resistance of KIT mutation-driven canine mast cell tumor cells.

PubMed

Kobayashi, Masato; Kuroki, Shiori; Kurita, Sena; Miyamoto, Ryo; Tani, Hiroyuki; Tamura, Kyoichi; Bonkobara, Makoto

2017-10-01

Overexpression of KIT is one of the mechanisms that contributes to imatinib resistance in KIT mutation-driven tumors. Here, the mechanism underlying this overexpression of KIT was investigated using an imatinib-sensitive canine mast cell tumor (MCT) line CoMS, which has an activating mutation in KIT exon 11. A KIT-overexpressing imatinib-resistant subline, rCoMS1, was generated from CoMS cells by their continuous exposure to increasing concentrations of imatinib. Neither a secondary mutation nor upregulated transcription of KIT was detected in rCoMS1 cells. A decrease in KIT ubiquitination, a prolonged KIT life-span, and KIT overexpression were found in rCoMS1 cells. These events were suppressed by withdrawal of imatinib and were re-induced by re‑treatment with imatinib. These findings suggest that imatinib elicited overexpression of KIT via suppression of its ubiquitination. These results also indicated that imatinib-induced overexpression of KIT in rCoMS1 cells was not a permanently acquired feature but was a reversible response of the cells. Moreover, the pan deubiquitinating enzyme inhibitor PR619 prevented imatinib induction of KIT overexpression, suggesting that the imatinib-induced decrease in KIT ubiquitination could be mediated by upregulation and/or activation of deubiquitinating enzyme(s). It may be possible that a similar mechanism of KIT overexpression underlies the acquisition of imatinib resistance in some human tumors that are driven by KIT mutation.

Review on methods for determination of metallothioneins in aquatic organisms.

PubMed

Shariati, Fatemeh; Shariati, Shahab

2011-06-01

One aspect of environmental degradation in coastal areas is pollution from toxic metals, which are persistent and are bioaccumulated by marine organisms, with serious public health implications. A conventional monitoring system of environmental metal pollution includes measuring the level of selected metals in the whole organism or in respective organs. However, measuring only the metal content in particular organs does not give information about its effect at the subcellular level. Therefore, the evaluation of biochemical biomarker metallothionein may be useful in assessing metal exposure and the prediction of potential detrimental effects induced by metal contamination. There are some methods for the determination of metallothioneins including spectrophotometric method, electrochemical methods, chromatography, saturation-based methods, immunological methods, electrophoresis, and RT-PCR. In this paper, different methods are discussed briefly and the comparison between them will be presented.

Metallothionein-1 and nitric oxide expression are inversely correlated in a murine model of Chagas disease

PubMed Central

Gonzalez-Mejia, Martha Elba; Torres-Rasgado, Enrique; Porchia, Leonardo M; Salgado, Hilda Rosas; Totolhua, José-Luis; Ortega, Arturo; Hernández-Kelly, Luisa Clara Regina; Ruiz-Vivanco, Guadalupe; Báez-Duarte, Blanca G; Pérez-Fuentes, Ricardo

2014-01-01

Chagas disease, caused by Trypanosoma cruzi, represents an endemic among Latin America countries. The participation of free radicals, especially nitric oxide (NO), has been demonstrated in the pathophysiology of seropositive individuals with T. cruzi. In Chagas disease, increased NO contributes to the development of cardiomyopathy and megacolon. Metallothioneins (MTs) are efficient free radicals scavengers of NO in vitro and in vivo. Here, we developed a murine model of the chronic phase of Chagas disease using endemic T. cruzi RyCH1 in BALB/c mice, which were divided into four groups: infected non-treated (Inf), infected N-monomethyl-L-arginine treated (Inf L-NAME), non-infected L-NAME treated and non-infected vehicle-treated. We determined blood parasitaemia and NO levels, the extent of parasite nests in tissues and liver MT-I expression levels. It was observed that NO levels were increasing in Inf mice in a time-dependent manner. Inf L-NAME mice had fewer T. cruzi nests in cardiac and skeletal muscle with decreased blood NO levels at day 135 post infection. This affect was negatively correlated with an increase of MT-I expression (r = -0.8462, p < 0.0001). In conclusion, we determined that in Chagas disease, an unknown inhibitory mechanism reduces MT-I expression, allowing augmented NO levels. PMID:24676665

The aryl hydrocarbon receptor and glucocorticoid receptor interact to activate human metallothionein 2A

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

Sato, Shoko, E-mail: satosho@rs.tus.ac.jp; Shirakawa, Hitoshi, E-mail: shirakah@m.tohoku.ac.jp; Tomita, Shuhei, E-mail: tomita@med.tottori-u.ac.jp

2013-11-15

Although the aryl hydrocarbon receptor (AHR) and glucocorticoid receptor (GR) play essential roles in mammalian development, stress responses, and other physiological events, crosstalk between these receptors has been the subject of much debate. Metallothioneins are classic glucocorticoid-inducible genes that were reported to increase upon treatment with AHR agonists in rodent tissues and cultured human cells. In this study, the mechanism of human metallothionein 2A (MT2A) gene transcription activation by AHR was investigated. Cotreatment with 3-methylcholanthrene and dexamethasone, agonists of AHR and GR respectively, synergistically increased MT2A mRNA levels in HepG2 cells. MT2A induction was suppressed by RNA interference against AHRmore » or GR. Coimmunoprecipitation experiments revealed a physical interaction between AHR and GR proteins. Moreover, chromatin immunoprecipitation assays indicated that AHR was recruited to the glucocorticoid response element in the MT2A promoter. Thus, we provide a novel mechanism whereby AHR modulates expression of human MT2A via the glucocorticoid response element and protein–protein interactions with GR. - Highlights: • Aryl hydrocarbon receptor forms a complex with glucocorticoid receptor in cells. • Human metallothionein gene is regulated by the AHR and GR interaction. • AHR–GR complex binds to glucocorticoid response element in metallothionein gene. • We demonstrated a novel transcriptional mechanism via AHR and GR interaction.« less

Improved n-butanol production via co-expression of membrane-targeted tilapia metallothionein and the clostridial metabolic pathway in Escherichia coli.

PubMed

Chin, Wei-Chih; Lin, Kuo-Hsing; Liu, Chun-Chi; Tsuge, Kenji; Huang, Chieh-Chen

2017-04-11

N-Butanol has favorable characteristics for use as either an alternative fuel or platform chemical. Bio-based n-butanol production using microbes is an emerging technology that requires further development. Although bio-industrial microbes such as Escherichia coli have been engineered to produce n-butanol, reactive oxygen species (ROS)-mediated toxicity may limit productivity. Previously, we show that outer-membrane-targeted tilapia metallothionein (OmpC-TMT) is more effective as an ROS scavenger than human and mouse metallothioneins to reduce oxidative stress in the host cell. The host strain (BUT1-DE) containing the clostridial n-butanol pathway displayed a decreased growth rate and limited n-butanol productivity, likely due to ROS accumulation. The clostridial n-butanol pathway was co-engineered with inducible OmpC-TMT in E. coli (BUT3-DE) for simultaneous ROS removal, and its effect on n-butanol productivity was examined. The ROS scavenging ability of cells overexpressing OmpC-TMT was examined and showed an approximately twofold increase in capacity. The modified strain improved n-butanol productivity to 320 mg/L, whereas the control strain produced only 95.1 mg/L. Transcriptomic analysis revealed three major KEGG pathways that were significantly differentially expressed in the BUT3-DE strain compared with their expression in the BUT1-DE strain, including genes involved in oxidative phosphorylation, fructose and mannose metabolism and glycolysis/gluconeogenesis. These results indicate that OmpC-TMT can increase n-butanol production by scavenging ROS. The transcriptomic analysis suggested that n-butanol causes quinone malfunction, resulting in oxidative-phosphorylation-related nuo operon downregulation, which would diminish the ability to convert NADH to NAD + and generate proton motive force. However, fructose and mannose metabolism-related genes (fucA, srlE and srlA) were upregulated, and glycolysis/gluconeogenesis-related genes (pfkB, pgm) were

A cadmium metallothionein gene of ridgetail white prawn Exopalaemon carinicauda (Holthuis, 1950) and its expression

NASA Astrophysics Data System (ADS)

Zhang, Jiquan; Wang, Jing; Xiang, Jianhai

2013-11-01

Metallothioneins (MTs) are a group of low molecular weight cysteine-rich proteins capable of binding heavy metal ions. A cadmium metallothionein ( EcMT — Cd) cDNA with a 189 bp open reading frame (ORF) that encoded a 62 amino acid protein was obtained from Exopalaemon carinicauda. Seventeen cysteines were in the deduced amino acid sequence, and the cysteine (Cys)-rich characteristic was revealed in different metallothioneins in other species. In addition, the deduced amino acid sequence did not contain any aromatic amino acid residues, such as tyrosine (Tyr), tryptophan (Trp), and phenylalanine (Phe). EcMT—Cd mRNA was expressed in all tested tissues (the ovary, muscle, stomach, and hepatopancreas), and its expression profiles in the hepatopancreas were very different when shrimps were exposed to seawater containing either 50 μmol/L CuSO4 or 2.5 μmol/L CdCl 2. The expression of EcMT-Cd was significantly up-regulated in shrimp exposed to CuSO4 for 12 h and down-regulated in shrimps exposed to CdCl2 for 12 h. After 24 h exposure to both metals, its expression was down-regulated. By contrast, at 48 h the EcMT-Cd was up-regulated in test shrimps exposed to CdCl2. The transcript of EcMT-Cd was very low or even absent before the zoea stage, and the expression of EcMT-Cd was detected from mysis larvae-I, then its expression began to rise. In conclusion, a cadmium MT exists in E. carinicauda that is expressed in different tissues and during different developmental stages, and responds to the challenge with heavy metal ions, which provides a clue to understanding the function of cadmium MT.

Overexpression of synapsin Ia in the rat calyx of Held accelerates short-term plasticity and decreases synaptic vesicle volume and active zone area

PubMed Central

Vasileva, Mariya; Renden, Robert; Horstmann, Heinz; Gitler, Daniel; Kuner, Thomas

2013-01-01

Synapsins are synaptic vesicle (SV) proteins organizing a component of the reserve pool of vesicles at most central nervous system synapses. Alternative splicing of the three mammalian genes results in multiple isoforms that may differentially contribute to the organization and maintenance of the SV pools. To address this, we first characterized the expression pattern of synapsin isoforms in the rat calyx of Held. At postnatal day 16, synapsins Ia, Ib, IIb and IIIa were present, while IIa—known to sustain repetitive transmission in glutamatergic terminals—was not detectable. To test if the synapsin I isoforms could mediate IIa-like effect, and if this depends on the presence of the E-domain, we overexpressed either synapsin Ia or synapsin Ib in the rat calyx of Held via recombinant adeno-associated virus-mediated gene transfer. Although the size and overall structure of the perturbed calyces remained unchanged, short-term depression and recovery from depression were accelerated upon overexpression of synapsin I isoforms. Using electron microscopic three-dimensional reconstructions we found a redistribution of SV clusters proximal to the active zones (AZ) alongside with a decrease of both AZ area and SV volume. The number of SVs at individual AZs was strongly reduced. Hence, our data indicate that the amount of synapsin Ia expressed in the calyx regulates the rate and extent of short-term synaptic plasticity by affecting vesicle recruitment to the AZ. Finally, our study reveals a novel contribution of synapsin Ia to define the surface area of AZs. PMID:24391547

BMP signaling and podocyte markers are decreased in human diabetic nephropathy in association with CTGF overexpression.

PubMed

Turk, Tamara; Leeuwis, Jan Willem; Gray, Julia; Torti, Suzy V; Lyons, Karen M; Nguyen, Tri Q; Goldschmeding, Roel

2009-07-01

Diabetic nephropathy is characterized by decreased expression of bone morphogenetic protein-7 (BMP-7) and decreased podocyte number and differentiation. Extracellular antagonists such as connective tissue growth factor (CTGF; CCN-2) and sclerostin domain-containing-1 (SOSTDC1; USAG-1) are important determinants of BMP signaling activity in glomeruli. We studied BMP signaling activity in glomeruli from diabetic patients and non-diabetic individuals and from control and diabetic CTGF(+/+) and CTGF(+/-) mice. BMP signaling activity was visualized by phosphorylated Smad1, -5, and -8 (pSmad1/5/8) immunostaining, and related to expression of CTGF, SOSTDC1, and the podocyte differentiation markers WT1, synaptopodin, and nephrin. In control and diabetic glomeruli, pSmad1/5/8 was mainly localized in podocytes, but both number of positive cells and staining intensity were decreased in diabetes. Nephrin and synaptopodin were decreased in diabetic glomeruli. Decrease of pSmad1/5/8 was only partially explained by decrease in podocyte number. SOSTDC1 and CTGF were expressed exclusively in podocytes. In diabetic glomeruli, SOSTDC1 decreased in parallel with podocyte number, whereas CTGF was strongly increased. In diabetic CTGF(+/-) mice, pSmad1/5/8 was preserved, compared with diabetic CTGF(+/+) mice. In conclusion, in human diabetic nephropathy, BMP signaling activity is diminished, together with reduction of podocyte markers. This might relate to concomitant overexpression of CTGF but not SOSTDC1.

Transcription patterns of genes encoding four metallothionein homologs in Daphnia pulex exposed to copper and cadmium are time- and homolog- dependent

PubMed Central

Asselman, Jana; Shaw, Joseph R.; Glaholt, Stephen P.; Colbourne, John K.; De Schamphelaere, Karel AC.

2013-01-01

Metallothioneins are proteins that play an essential role in metal homeostasis and detoxification in nearly all organisms studied to date. Yet discrepancies between outcomes of chronic and acute exposure experiments hamper the understanding of the regulatory mechanisms of their isoforms following metal exposure. Here, we investigated transcriptional differences among four identified homologs (mt1–mt4) in Daphnia pulex exposed across time to copper and cadmium relative to a control. Transcriptional upregulation of mt1 and mt3 was detected on day four following exposure to cadmium, whereas that of mt2 and mt4 was detected on day two and day eight following exposure to copper. These results confirm temporal and metal-specific differences in the transcriptional induction of genes encoding metallothionein homologs upon metal exposure which should be considered in ecotoxicological monitoring programs of metal-contaminated water bodies. Indeed, the mRNA expression patterns observed here illustrate the complex regulatory system associated with metallothioneins, as these patterns are not only dependent on the metal, but also on exposure time and the homolog studied. Further phylogenetic analysis and analysis of regulatory elements in upstream promoter regions revealed a high degree of similarity between metallothionein genes of Daphnia pulex and Daphnia magna, a species belonging to the same genus. These findings, combined with a limited amount of available expression data for D. magna metallothionein genes, tentatively suggest a potential generalization of the metallothionein response system between these Daphnia species. PMID:24113165

Genetic improvement of butanol tolerance in Escherichia coli by cell surface expression of fish metallothionein.

PubMed

Lin, Kuo Hsing; Chin, Wei Chih; Lee, Ang Hsuan; Huang, Chieh Chen

2011-01-01

Cysteine-rich metallothioneins (MTs) have been reported to possess the capacity to scavenge reactive oxygen species in vitro and in vivo. Recombinant strains of Escherichia coli expressing outer membrane protein C (OmpC) fused with MTs from human, mouse and tilapia displayed the ability for such surface-localized MTs to scavenge extracellular free radicals, but the benefits of the possible applications of this capacity have not yet been demonstrated. Because the intrinsic butanol tolerance of microbes has become an impediment for biological butanol production, we examined whether surface-displayed MTs could contribute to butanol tolerance. The results show that strains expressing OmpC-MT fusion proteins had higher butanol tolerance than strains with cytoplasmically expressed MTs. Furthermore, the OmpC-tilapia MT fusion protein enhanced butanol tolerance more strongly than other recombinant constructs. Although the enhanced level of tolerance was not as high as that provided by OmpC-tilapia MT, over-expression of OmpC was also found to contribute to butanol tolerance. These results suggest that free-radical scavenging by MT and OmpC-related osmoregulation enhance butanol tolerance. Our results shed new light on methods for engineering bacteria with higher butanol tolerance. © 2011 Landes Bioscience

BMP Signaling and Podocyte Markers Are Decreased in Human Diabetic Nephropathy in Association With CTGF Overexpression

PubMed Central

Turk, Tamara; Leeuwis, Jan Willem; Gray, Julia; Torti, Suzy V.; Lyons, Karen M.; Nguyen, Tri Q.; Goldschmeding, Roel

2009-01-01

Diabetic nephropathy is characterized by decreased expression of bone morphogenetic protein-7 (BMP-7) and decreased podocyte number and differentiation. Extracellular antagonists such as connective tissue growth factor (CTGF; CCN-2) and sclerostin domain-containing-1 (SOSTDC1; USAG-1) are important determinants of BMP signaling activity in glomeruli. We studied BMP signaling activity in glomeruli from diabetic patients and non-diabetic individuals and from control and diabetic CTGF+/+ and CTGF+/− mice. BMP signaling activity was visualized by phosphorylated Smad1, -5, and -8 (pSmad1/5/8) immunostaining, and related to expression of CTGF, SOSTDC1, and the podocyte differentiation markers WT1, synaptopodin, and nephrin. In control and diabetic glomeruli, pSmad1/5/8 was mainly localized in podocytes, but both number of positive cells and staining intensity were decreased in diabetes. Nephrin and synaptopodin were decreased in diabetic glomeruli. Decrease of pSmad1/5/8 was only partially explained by decrease in podocyte number. SOSTDC1 and CTGF were expressed exclusively in podocytes. In diabetic glomeruli, SOSTDC1 decreased in parallel with podocyte number, whereas CTGF was strongly increased. In diabetic CTGF+/− mice, pSmad1/5/8 was preserved, compared with diabetic CTGF+/+ mice. In conclusion, in human diabetic nephropathy, BMP signaling activity is diminished, together with reduction of podocyte markers. This might relate to concomitant overexpression of CTGF but not SOSTDC1. (J Histochem Cytochem 57:623–631, 2009) PMID:19255250

Quantitative immunodetection of metallothioneins in relation to metals concentration in spiders from variously polluted areas.

PubMed

Babczyńska, Agnieszka; Wilczek, Grażyna; Szulińska, Elżbieta; Franiel, Izabella

2011-09-01

Spiders inhabiting post industrial environments, such as waste heaps or ore-bearing areas, are exposed to high concentrations of metals, accumulated in the body of their prey and transferred along food chains. Therefore spiders are pressed to develop metal-neutralization strategies. Low-molecular, multifunction proteins: metallothioneins (MTs), often postulated as biomarkers of metal exposure, are known to bind metals and thus protect organisms against their toxic effects. Yet the proteins are still not well recognized in spiders. The aim of this study was to assess, by immunodetection method, ELISA, the concentration of metallothioneins in adult females of three web building spider species: Araneus diadematus (Araneidae), Agelena labyrinthica (Agelenidae) and Linyphia triangularis (Linyphiidae) from three variously polluted areas in southern Poland: Olkusz, ore-bearing post industrial site; Katowice-WeŁnowiec: post metallurgic waste heap, Pilica: the reference, rural, area. The concentration of metallothioneins has been analyzed in relation to the metal concentration in spiders body. The study gives the evidence that metallothioneins are reliably detectable by means of ELISA technique. The analysis of results obtained shows a strong species-dependence of the MTs level. Positive correlations between MTs concentration and metal body burden (mainly Zn and Pb) were found. This suggests that the proteins play an important role in the neutralization and regulation of metal ions in spiders. The same correlation indicate the possibility to consider MTs in spiders as biomarkers of metal exposure and effects. However, the species specificity as well as metal characteristics should be taken under account. Copyright © 2011 Elsevier Inc. All rights reserved.

Overexpression of IGF-I receptor in HeLa cells enhances in vivo radioresponse

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

Kaneko, Haruna; Yu, Dong; Miura, Masahiko

2007-11-30

Insulin-like growth factor I receptor (IGF-IR) is a transmembrane receptor tyrosine kinase whose activation strongly promotes cell growth and survival. We previously reported that IGF-IR activity confers intrinsic radioresistance in mouse embryo fibroblasts in vitro. However, it is still unclear whether tumor cells overexpressing IGF-IR exhibit radioresistance in vivo. For this purpose, we established HeLa cells that overexpress IGF-IR (HeLa-R), subcutaneously transplanted these cells into nude mice, and examined radioresponse in the resulting solid tumors. HeLa-R cells exhibited typical in vitro phenotypes generally observed in IGF-IR-overexpressing cells, as well as significant intrinsic radioresistance in vitro compared with parent cells. Asmore » expected, the transplanted HeLa-R tumors grew at a remarkably higher rate than parent tumors. Histological analysis revealed that HeLa-R tumors expressed more VEGF and had a higher density of tumor vessels. Unexpectedly, a marked growth delay was observed in HeLa-R tumors following 10 Gy of X-irradiation. Immunostaining of HeLa-R tumors for the hypoxia marker pimonidazole revealed a significantly lower level of hypoxic cells. Moreover, clamp hypoxia significantly increased radioresistance in HeLa-R tumors. Tumor microenvironments in vivo generated by the IGF-IR expression thus could be a major factor in determining the tumor radioresponse in vivo.« less

Secretory overexpression and isotopic labeling of the chimeric relaxin family peptide R3/I5 in Pichia pastoris.

PubMed

Guo, Yu-Qi; Wu, Qing-Ping; Shao, Xiao-Xia; Shen, Ting; Liu, Ya-Li; Xu, Zeng-Guang; Guo, Zhan-Yun

2015-06-01

Relaxin family peptides are a group of peptide hormones with divergent biological functions. Mature relaxin family peptides are typically composed of two polypeptide chains with three disulfide linkages, rendering their preparation a challenging task. In the present study, we established an efficient approach for preparation of the chimeric relaxin family peptide R3/I5 through secretory overexpression in Pichia pastoris and in vitro enzymatic maturation. A designed single-chain R3/I5 precursor containing the B-chain of human relaxin-3 and the A-chain of human INSL5 was overexpressed in PichiaPink strain 1 by high-density fermentation in a two-liter fermenter, and approximately 200 mg of purified precursor was obtained from one liter of the fermentation supernatant. We also developed an economical approach for preparation of the uniformly (15)N-labeled R3/I5 precursor by culturing in shaking flasks, and approximately 15 mg of purified (15)N-labeled precursor was obtained from one liter of the culture supernatant. After purification by cation ion-exchange chromatography and reverse-phase high performance liquid chromatography, the R3/I5 precursor was converted to the mature two-chain form by sequential treatment with endoproteinase Lys-C and carboxypeptidase B. The mature R3/I5 peptide had an α-helix-dominated conformation and retained full receptor-binding and receptor activation activities. Thus, Pichia overexpression was an efficient approach for sample preparation and isotopic labeling of the chimeric R3/I5 peptide. This approach could also be extended to the preparation of other relaxin family peptides in future studies.

Diet-Induced Over-Expression of Flightless-I Protein and Its Relation to Flightlessness in Mediterranean Fruit Fly, Ceratitis capitata

PubMed Central

Cho, Il Kyu; Chang, Chiou Ling; Li, Qing X.

2013-01-01

The Mediterranean fruit fly (medfly), Ceratitis capitata is among the most economically important pests worldwide. Understanding nutritional requirement helps rearing healthy medfly for biocontrol of its population in fields. Flight ability is a high priority criterion. Two groups of medfly larvae were reared with two identical component diets except one with fatty acids (diet A) and another without it (diet B). Adults from larvae reared on diet B demonstrated 20±8% of normal flight ability, whereas those from larvae reared on diet A displayed full flight ability of 97±1%. Proteomes were profiled to compare two groups of medfly pupae using shotgun proteomics to study dietary effects on flight ability. When proteins detected in pupae A were compared with those in pupae B, 233 and 239 proteins were, respectively, under- and over-expressed in pupae B, while 167 proteins were overlapped in both pupae A and B. Differential protein profiles indicate that nutritional deficiency induced over-expression of flightless-I protein (fli-I) in medfly. All proteins were subjected to Ingenuity Pathway Analysis (IPA) to create 13 biological networks and 17 pathways of interacting protein clusters in human ortholog. Fli-I, leucine-rich repeat (LRR)-containing G protein-coupled receptor 2, LRR protein soc-2 and protein wings apart-like were over-expressed in pupae B. Inositol-1,4,5-trisphosphate receptor, protocadherin-like wing polarity protein stan and several Wnt pathway proteins were under-expressed in pupae B. These results suggest down-regulation of the Wnt/wingless signaling pathway, which consequently may result in flightlessness in pupae B. The fli-I gene is known to be located within the Smith-Magenis syndrome (SMS) region on chromosome 17, and thus, we speculate that nutritional deficiency might induce over-expression of fli-I (or fli-I gene) and be associated with human SMS. However, more evidence would be needed to confirm our speculation. PMID:24312525

SIRT1 Overexpression Maintains Cell Phenotype and Function of Endothelial Cells Derived from Induced Pluripotent Stem Cells.

PubMed

Jiang, Bin; Jen, Michele; Perrin, Louisiane; Wertheim, Jason A; Ameer, Guillermo A

2015-12-01

Endothelial cells (ECs) that are differentiated from induced pluripotent stem cells (iPSCs) can be used in establishing disease models for personalized drug discovery or developing patient-specific vascularized tissues or organoids. However, a number of technical challenges are often associated with iPSC-ECs in culture, including instability of the endothelial phenotype and limited cell proliferative capacity over time. Early senescence is believed to be the primary mechanism underlying these limitations. Sirtuin1 (SIRT1) is an NAD(+)-dependent deacetylase involved in the regulation of cell senescence, redox state, and inflammatory status. We hypothesize that overexpression of the SIRT1 gene in iPSC-ECs will maintain EC phenotype, function, and proliferative capacity by overcoming early cell senescence. SIRT1 gene was packaged into a lentiviral vector (LV-SIRT1) and transduced into iPSC-ECs at passage 4. Beginning with passage 5, iPSC-ECs exhibited a fibroblast-like morphology, whereas iPSC-ECs overexpressing SIRT1 maintained EC cobblestone morphology. SIRT1 overexpressing iPSC-ECs also exhibited a higher percentage of canonical markers of endothelia (LV-SIRT1 61.8% CD31(+) vs. LV-empty 31.7% CD31(+), P < 0.001; LV-SIRT1 46.3% CD144(+) vs. LV-empty 20.5% CD144(+), P < 0.02), with a higher nitric oxide synthesis, lower β-galactosidase production indicating decreased senescence (3.4% for LV-SIRT1 vs. 38.6% for LV-empty, P < 0.001), enhanced angiogenesis, increased deacetylation activity, and higher proliferation rate. SIRT1 overexpressing iPSC-ECs continued to proliferate through passage 9 with high purity of EC-like characteristics, while iPSC-ECs without SIRT1 overexpression became senescent after passage 5. Taken together, SIRT1 overexpression in iPSC-ECs maintains EC phenotype, improves EC function, and extends cell lifespan, overcoming critical hurdles associated with the use of iPSC-ECs in translational research.

Partial contribution of the Keap1–Nrf2 system to cadmium-mediated metallothionein expression in vascular endothelial cells

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

Shinkai, Yasuhiro; Kimura, Tomoki; Itagaki, Ayaka

Cadmium is an environmental electrophile that modifies protein reactive thiols such as Kelch-like ECH-associated protein 1 (Keap1), a negative regulator of nuclear factor-erythroid 2-related factor 2 (Nrf2). In the present study, we investigated a role of the Keap1–Nrf2 system in cellular response to cadmium in vascular endothelial cells. Exposure of bovine aortic endothelial cells to cadmium resulted in modification of Keap1 and Nrf2 activation, thereby up-regulating not only its typical downstream proteins but also metallothionein-1/2. Experiments with siRNA-mediated knockdown of Nrf2 or Keap1 supported participation of the Keap1–Nrf2 system in the modulation of metallothionein-1/2 expression. Furthermore, chromatin immunoprecipitation assay showedmore » that Nrf2 was recruited to the antioxidant response element of the promoter region of the bovine metallothionein-2 gene in the presence of cadmium. These results suggest that the transcription factor Nrf2 plays, at least in part, a role in the changes in metallothionein expression mediated by exposure to cadmium. - Highlights: • Role of the Keap1–Nrf2 system in cellular response to cadmium was examined. • We used bovine aortic endothelial cells as a model of the vascular endothelium. • Exposure of cells to cadmium resulted in modification of Keap1 and Nrf2 activation. • Keap1–Nrf2 system participated in the modulation of metallothionein-1/2 expression. • Nrf2 was recruited to the antioxidant response element of MT2 promoter region.« less

Overexpression of the Transcription Factor Sp1 Activates the OAS-RNAse L-RIG-I Pathway

PubMed Central

Dupuis-Maurin, Valéryane; Brinza, Lilia; Baguet, Joël; Plantamura, Emilie; Schicklin, Stéphane; Chambion, Solène; Macari, Claire; Tomkowiak, Martine; Deniaud, Emmanuelle; Leverrier, Yann

2015-01-01

Deregulated expression of oncogenes or transcription factors such as specificity protein 1 (Sp1) is observed in many human cancers and plays a role in tumor maintenance. Paradoxically in untransformed cells, Sp1 overexpression induces late apoptosis but the early intrinsic response is poorly characterized. In the present work, we studied increased Sp1 level consequences in untransformed cells and showed that it turns on an early innate immune transcriptome. Sp1 overexpression does not activate known cellular stress pathways such as DNA damage response or endoplasmic reticulum stress, but induces the activation of the OAS-RNase L pathway and the generation of small self-RNAs, leading to the upregulation of genes of the antiviral RIG-I pathway at the transcriptional and translational levels. Finally, Sp1-induced intrinsic innate immune response leads to the production of the chemokine CXCL4 and to the recruitment of inflammatory cells in vitro and in vivo. Altogether our results showed that increased Sp1 level in untransformed cells constitutes a novel danger signal sensed by the OAS-RNase L axis leading to the activation of the RIG-I pathway. These results suggested that the OAS-RNase L-RIG-I pathway may be activated in sterile condition in absence of pathogen. PMID:25738304

Impact of intracellular metallothionein on metal biouptake and partitioning dynamics at bacterial interfaces.

PubMed

Présent, Romain M; Rotureau, Elise; Billard, Patrick; Pagnout, Christophe; Sohm, Bénédicte; Flayac, Justine; Gley, Renaud; Pinheiro, José P; Duval, Jérôme F L

2017-11-08

Genetically engineered microorganisms are alternatives to physicochemical methods for remediation of metal-contaminated aquifers due to their remarkable bioaccumulation capacities. The design of such biosystems would benefit from the elaboration of a sound quantitative connection between performance in terms of metal removal from aqueous solution and dynamics of the multiscale processes leading to metal biouptake. In this work, this elaboration is reported for Escherichia coli cells modified to overexpress intracellular metallothionein (MTc), a strong proteinaceous metal chelator. Depletion kinetics of Cd(ii) from bulk solution following biouptake and intracellular accumulation is addressed as a function of cell volume fraction using electroanalytical probes and ligand exchange-based analyses. It is shown that metal biouptake in the absence and presence of MTc is successfully interpreted on the basis of a formalism recently developed for metal partitioning dynamics at biointerfaces with integration of intracellular metal speciation. The analysis demonstrates how fast sequestration of metals by intracellular MTc bypasses metal excretion (efflux) and enhances the rate of metal depletion to an extent such that complete removal is achieved at sufficiently large cell volume fractions. The magnitude of the stability constant of nanoparticulate metal-MTc complexes, as derived from refined analysis of macroscopic bulk metal depletion data, is further confirmed by independent electrochemical measurement of metal binding by purified MTc extracts.

Metallothionein deficiency aggravates depleted uranium-induced nephrotoxicity

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

Hao, Yuhui; Huang, Jiawei; Gu, Ying

Depleted uranium (DU) has been widely used in both civilian and military activities, and the kidney is the main target organ of DU during acute high-dose exposures. In this study, the nephrotoxicity caused by DU in metallothionein-1/2-null mice (MT −/−) and corresponding wild-type (MT +/+) mice was investigated to determine any associations with MT. Each MT −/− or MT +/+ mouse was pretreated with a single dose of DU (10 mg/kg, intraperitoneal injection) or an equivalent volume of saline. After 4 days of DU administration, kidney changes were assessed. After DU exposure, serum creatinine and serum urea nitrogen in MTmore » −/− mice significantly increased than in MT +/+ mice, with more severe kidney pathological damage. Moreover, catalase and superoxide dismutase (SOD) decreased, and generation of reactive oxygen species and malondialdehyde increased in MT −/− mice. The apoptosis rate in MT −/− mice significantly increased, with a significant increase in both Bax and caspase 3 and a decrease in Bcl-2. Furthermore, sodium-glucose cotransporter (SGLT) and sodium-phosphate cotransporter (NaPi-II) were significantly reduced after DU exposure, and the change of SGLT was more evident in MT −/− mice. Finally, exogenous MT was used to evaluate the correlation between kidney changes induced by DU and MT doses in MT −/− mice. The results showed that, the pathological damage and cell apoptosis decreased, and SOD and SGLT levels increased with increasing dose of MT. In conclusion, MT deficiency aggravated DU-induced nephrotoxicity, and the molecular mechanisms appeared to be related to the increased oxidative stress and apoptosis, and decreased SGLT expression. - Highlights: • MT −/− and MT +/+ mice were used to evaluate nephrotoxicity of DU. • Renal damage was more evident in the MT −/− mice after exposure to DU. • Exogenous MT also protects against DU-induced nephrotoxicity. • MT deficiency induced more ROS and apoptosis after

Metallothionein Gene Duplications and Metal Tolerance in Natural Populations of Drosophila melanogaster

PubMed Central

Maroni, G.; Wise, J.; Young, J. E.; Otto, E.

1987-01-01

A search for duplications of the Drosophila melanogaster metallothionein gene (Mtn) yielded numerous examples of this type of chromosomal rearrangement. These duplications are distributed widely—we found them in samples from four continents, and they are functional—larvae carrying Mtn duplications produce more Mtn RNA and tolerate increased cadmium and copper concentrations. Six different duplication types were characterized by restriction-enzyme analyses using probes from the Mtn region. The restriction maps show that in four cases the sequences, ranging in size between 2.2 and 6.0 kb, are arranged as direct, tandem repeats; in two other cases, this basic pattern is modified by the insertion of a putative transposable element into one of the repeated units. Duplications of the D. melanogaster metallothionein gene such as those that we found in natural populations may represent early stages in the evolution of a gene family. PMID:2828157

Response of phase I and II detoxification enzymes, glutathione, metallothionein and acetylcholine esterase to mercury and dimethoate in signal crayfish (Pacifastacus leniusculus).

PubMed

Gunderson, Mark P; Nguyen, Brandon T; Cervantes Reyes, Juan C; Holden, Laura L; French, John M T; Smith, Brandon D; Lineberger, Connor

2018-05-30

Metals and pesticides are common pollutants and the modulation of biomarkers can indicate sub-lethal influences on the physiology of organisms inhabiting impacted aquatic systems. We examined the effects of mercury and the organophosphate pesticide dimethoate on EROD, MROD, glutathione S-transferase (GST), acetylcholine esterase (AChE), metallothionein (MT) and glutathione (GSH) in the signal crayfish (Pacifastacus leniusculus). Crayfish were injected with mercury chloride or dimethoate (0.3, 0.6, 0.9 μg kg -1 ) and dissected after 72 h. EROD activity in the hepatopancreas did not change in response to mercury chloride treatment but exhibited a dose dependent decrease at all concentrations of dimethoate tested. MROD (hepatopancreas) exhibited a significant decrease at the 0.9 μg kg -1 treatment for both chemicals. GST (hepatopancreas) demonstrated a significant dose dependent decrease at all concentrations of both mercury chloride and dimethoate. AChE (tail muscle) decreased at the 0.6 and 0.9 μg kg -1 concentrations of dimethoate and 0.9 μg kg -1 mercury chloride. In gill tissue, MT increased in response to 0.3 and 0.6 μg kg -1 of mercury chloride but no effect was observed at the 0.9 μg kg -1 concentration of mercury chloride or any concentrations of dimethoate tested. MT did not change in response to mercury or dimethoate in tail tissue. Furthermore, neither chemical modulated GSH concentrations. Our results indicate that, apart from GSH, these markers are sensitive to the pollutants tested and that animals exposed in the wild are potentially compromised in their ability to detoxify environmental contaminants and carry out normal cellular processes. Copyright © 2018 Elsevier Ltd. All rights reserved.

Evaluation of cadmium, lead and metallothionein contents in the tissues of mussels (Mytilus galloprovincialis) from the Campania coast (Italy): levels and seasonal trends.

PubMed

Scudiero, Rosaria; Cretì, Patrizia; Trinchella, Francesca; Grazia Esposito, Maria

2014-01-01

The biological effect of seasonality on cadmium, lead and metallothionein contents was assessed in mussels Mytilus galloprovincialis from natural banks located along the coastline of the Gulf of Naples (Campania, Italy). Heavy metals and metallothionein concentrations were measured in digestive and reproductive glands. The results showed a clear correlation between metallothionein content and the reproductive gland status determined during the seasons; on the contrary, no correlation was found between metallothionein and metal contents. Data allow us to hypothesize that metallothionein functions go beyond metal detoxification, thus opening new scenarios for these proteins in invertebrates. The effect of seasons on metals concentration in mussel tissues showed similar seasonal patterns between the sites, regardless of their anthropogenic impacts. Cadmium content was not strictly related to seasonal periods, whereas lead content was significantly lower in summer. The results also indicate that the metal contents in mussels from the Gulf of Naples do not represent a risk to human health, even in the period of their maximum accumulation, and that the relaying of mussels before marketing could improve the animal stress conditions, but having a slight effect on metal excretion. Copyright © 2014 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Bile acid receptor TGR5 overexpression is associated with decreased intestinal mucosal injury and epithelial cell proliferation in obstructive jaundice.

PubMed

Ji, Chen-Guang; Xie, Xiao-Li; Yin, Jie; Qi, Wei; Chen, Lei; Bai, Yun; Wang, Na; Zhao, Dong-Qiang; Jiang, Xiao-Yu; Jiang, Hui-Qing

2017-04-01

Bile acids stimulate intestinal epithelial proliferation in vitro. We sought to investigate the role of the bile acid receptor TGR5 in the protection of intestinal epithelial proliferation in obstructive jaundice. Intestinal tissues and serum samples were obtained from patients with malignant obstructive jaundice and from bile duct ligation (BDL) rats. Intestinal permeability and morphological changes in the intestinal mucosa were observed. The functions of TGR5 in cell proliferation in intestinal epithelial injury were determined by overexpression or knockdown studies in Caco-2 and FHs 74 Int cells pretreated with lipopolysaccharide (LPS). Internal biliary drainage was superior to external biliary drainage in recovering intestinal permeability and mucosal histology in patients with obstructive jaundice. In BDL rats, feeding of chenodeoxycholic acid (CDCA) decreased intestinal mucosa injury. The levels of PCNA, a marker of proliferation, increased in response to CDCA feeding and were paralleled by elevated TGR5 expression. CDCA upregulated TGR5 expression and promoted proliferation in Caco-2 and FHs 74 Int cells pretreated with LPS. Overexpression of TGR5 resulted in increased PCNA, cell viability, EdU incorporation, and the proportion of cells in S phase, whereas knockdown of TGR5 had the opposite effect. Our data indicate that bile acids promote intestinal epithelial cell proliferation and decrease mucosal injury by upregulating TGR5 expression in obstructive jaundice. Copyright © 2016 Elsevier Inc. All rights reserved.

Mitochondrial electron transport is inhibited by disappearance of metallothionein in human bronchial epithelial cells following exposure to silver nitrate.

PubMed

Miyayama, Takamitsu; Arai, Yuta; Suzuki, Noriyuki; Hirano, Seishiro

2013-03-08

Silver (Ag) possesses antibacterial activity and has been used in wound dressings and deodorant powders worldwide. However, the metabolic behavior and biological roles of Ag in mammals have not been well characterized. In the present study, we exposed human bronchial epithelial cells (BEAS-2B) to AgNO3 and investigated uptake and intracellular distribution of Ag, expression of metallothionein (MT), generation of reactive oxygen species (ROS), and changes in mitochondrial respiration. The culture medium concentration of Ag decreased with time and stabilized at 12h. The concentration of both Ag and MT in the soluble cellular fraction increased up to 3h and then decreased, indicating that cytosolic Ag relocated to the insoluble fraction of the cells. The levels of mRNAs for the major human MT isoforms MT-I and MT-II paralleled with the protein levels of Ag-MT. The intensity of fluorescence derived from ROS was elevated in the mitochondrial region at 24h. Ag decreased mitochondrial oxygen consumption in a dose-dependent manner and the activity of mitochondrial complex I-IV enzymes was significantly inhibited following exposure to Ag. In a separate experiment, we found that hydrogen peroxide (H2O2) at concentrations as low as 0.001% (equivalent to the concentration of H2O2 in Ag-exposed cells) removed Ag from MT. These results suggest MT was decomposed by cytosolic H2O2, and then Ag released from MT relocated to insoluble cellular fractions and inhibited electron chain transfer of mitochondrial complexes, which eventually led to cell damage. Crown Copyright © 2013. Published by Elsevier Ireland Ltd. All rights reserved.

Changes in Metallothionein Level in Rat Hepatic Tissue after Administration of Natural Mouldy Wheat

PubMed Central

Vasatkova, Anna; Krizova, Sarka; Adam, Vojtech; Zeman, Ladislav; Kizek, Rene

2009-01-01

Mycotoxins are secondary metabolites produced by microfungi that are capable of causing disease and death in humans and other animals. This work was aimed at investigation of influence of mouldy wheat contaminated by pathogenic fungi producing mycotoxins on metallothionein levels in hepatic tissue of rats. The rats were administrating feed mixtures with different contents of vitamins or naturally mouldy wheat for 28 days. It was found that the wheat contained deoxynivalenol (80 ± 5 μg per kg of mouldy wheat), zearalenone (56 ± 3 μg/kg), T2-toxin (20 ± 2 μg/kg) and aflatoxins as a sum of B1, B2, G1 and G2 (3.9 ± 0.2 μg/kg). Rats were fed diets containing 0, 33, 66 and 100% naturally moulded wheat. Control group 0, 33, 66 and 100% contained vitamins according to Nutrient Requirements of Rats (NRC). Other four groups (control group with vitamins, vit33, vit66 and vit100%) were fed on the same levels of mouldy wheat, also vitamins at levels 100% higher than the previous mixtures. We determined weight, feed conversion and performed dissection to observe pathological processes. Changes between control group and experimental groups exposed to influence of mouldy wheat and experimental groups supplemented by higher concentration of vitamins and mouldy wheat were not observed. Livers were sampled and did not demonstrate significant changes in morphology compared to control either. In the following experiments the levels of metallothionein as a marker of oxidative stress was determined. We observed a quite surprising trend in metallothionein levels in animals supplemented with increased concentration of vitamins. Its level enhanced with increasing content of mouldy wheat. It was possible to determine a statistically significant decline (p<0.05) between control group and groups of animals fed with 33, 66 and 100% mouldy wheat. It is likely that some mycotoxins presented in mouldy wheat are able to block the mechanism of metallothionein synthesis. PMID:19399242

Radionuclide therapy using ¹³¹I-labeled anti-epidermal growth factor receptor-targeted nanoparticles suppresses cancer cell growth caused by EGFR overexpression.

PubMed

Li, Wei; Liu, Zhongyun; Li, Chengxia; Li, Ning; Fang, Lei; Chang, Jin; Tan, Jian

2016-03-01

Anti-epidermal growth factor receptor (EGFR)-targeted nanoparticles can be used to deliver a therapeutic and imaging agent to EGFR-overexpressing tumor cells. (131)I-labeled anti-EGFR nanoparticles derived from cetuximab were used as a tumor-targeting vehicle in radionuclide therapy. This paper describes the construction of the anti-EGFR nanoparticle EGFR-BSA-PCL. This nanoparticle was characterized for EGFR-targeted binding and cellular uptake in EGFR-overexpressing cancer cells by using flow cytometry and confocal microscopy. Anti-EGFR and non-targeted nanoparticles were labeled with (131)I using the chloramine-T method. Analyses of cytotoxicity and targeted cell killing with (131)I were performed using the MTT assay. The time-dependent cellular uptake of (131)I-labeled anti-EGFR nanoparticles proved the slow-release effects of nanoparticles. A radioiodine therapy study was also performed in mice. The EGFR-targeted nanoparticle EGFR-BSA-PCL and the non-targeted nanoparticle BSA-PCL were constructed; the effective diameters were approximately 100 nm. The results from flow cytometry and confocal microscopy revealed significant uptake of EGFR-BSA-PCL in EGFR-overexpressing tumor cells. Compared with EGFR-BSA-PCL, BSA-PCL could also bind to cells, but tumor cell retention was minimal and weak. In MTT assays, the EGFR-targeted radioactive nanoparticle (131)I-EGFR-BSA-PCL showed greater cytotoxicity and targeted cell killing than the non-targeted nanoparticle (131)I-BSA-PCL. The radioiodine uptake of both (131)I-labeled nanoparticles, (131)I-EGFR-BSA-PCL and (131)I-BSA-PCL, was rapid and reached maximal levels 4 h after incubation, but the (131)I uptake of (131)I-EGFR-BSA-PCL was higher than that of (131)I-BSA-PCL. On day 15, the average tumor volumes of the (131)I-EGFR-BSA-PCL and (131)I-BSA-PCL groups showed a slow growth relationship compared with that of the control group. The EGFR-targeted nanoparticle EGFR-BSA-PCL demonstrated superior cellular binding and uptake

Immunohistochemical expression of metallothionein in normal human colorectal mucosa, in adenomas and in adenocarcinomas and their associated metastases.

PubMed

Giuffrè, G; Barresi, G; Sturniolo, G C; Sarnelli, R; D'Incà, R; Tuccari, G

1996-10-01

The immunohistochemical distribution pattern of metallothionein, a low molecular weight protein with strong affinity for divalent heavy metal ions, has been investigated in normal and neoplastic conditions of the large bowel. Utilizing a monoclonal mouse antibody the following formalin-fixed paraffin-embedded surgical or biopsy samples were studied: tubulo-villous adenomas (8 cases); adenocarcinomas with various degree of differentiation (85), nine of which were mucinous-type; synchronous tubular or tubulo-villous adenomas separate from carcinomas (30); transitional mucosa (45); metastases in lymph nodes (43); and distant metastases (45). Twenty biopsies from the right and left colon of 10 patients affected by irritable bowel syndrome were also analyzed. Normal colonic mucosa as well as transitional mucosa showed metallothionein immunopositivity in enterocytes at the luminal surface and crypts. Evident nuclear and cytoplasmic staining was encountered in tubulo-villous adenomas; the same reactivity was noted in the basal glandular component of colorectal carcinomas-synchronous adenomas, while less intense staining was noted in the apical villous portions. A variable metallothionein immunostaining was observed in adenocarcinomas (62.3%), in lymph node (55.8%) and distant hepatic (17.2%) and omental (43.8%) metastases, although it was not always concordant with that reported in the corresponding primary tumour. Whether the metallothionein positivity observed in normal and neoplastic cells is the result of expression of a stable form of the protein or an accumulation in the nucleus and cytoplasm remains to be clarified.

Alterations of tissue metallothionein and vitellogenin concentrations in tropical cup oysters (Saccostrea sp.) following short-term (96h) exposure to cadmium.

PubMed

Moncaleano-Niño, Angela M; Barrios-Latorre, Sergio A; Poloche-Hernández, Javier F; Becquet, Vanessa; Huet, Valérie; Villamil, Luisa; Thomas-Guyon, Hélène; Ahrens, Michael J; Luna-Acosta, Andrea

2017-04-01

Metallothioneins and vitellogenins are low molecular weight proteins that have been used widely in environmental monitoring as biomarkers of exposure and damage to metals and estrogenic compounds, respectively. In the present study, the responses of metallothionein and vitellogenin tissue concentrations were measured following acute (96h) aqueous exposures to cadmium in Saccostrea sp., a tropical cup oyster native to the Western Pacific Ocean that has recently established itself in the Caribbean Sea. Adult oysters (1.5-5.0cm shell length) collected from the municipal marina of Santa Marta, Colombia (Caribbean Sea) and acclimated for 5days in the laboratory, were exposed to Cd at five concentrations (0, 1, 10, 100 and 1000μg/L) and their tissues (gills, digestive gland and adductor muscle) were analyzed in pools of 5 individuals (3 replicates per concentration). Metallothioneins in digestive glands of oysters exposed to Cd concentrations≥100μg/L showed a significant increase, from 8.0 to 14.8μg MT/mg total protein, whereas metallothionein concentrations in gills increased to lesser extent, and no differences were observed in adductor muscle. Metallothionein concentrations in digestive gland and gills correlated directly with whole soft tissue Cd concentrations (ranging from 2 to 297μg/g dw Cd). Vitellogenin in homogenates of oyster gonad tissue, after 96h of exposure to 1000μg/L Cd, were significantly lower (0.04mg P/g gonad) compared to control oysters (0.68mg P/g gonad), suggestive of an anti-estrogenic effect of Cd at high concentrations, whereas no significant changes in vitellogenin concentrations were observed at intermediate Cd exposure concentrations. This study confirms acute responses of metallothionein and vitellogenin concentrations in tissues of Saccostrea sp. exposed to high concentrations of cadmium (Cd≥100μg/L, 96h). The present results are first step towards validating the use of these two proteins as biomarkers of metal exposure in this

Phase I study of nanoparticle albumin-bound paclitaxel, carboplatin and trastuzumab in women with human epidermal growth factor receptor 2-overexpressing breast cancer

PubMed Central

Tezuka, Kenji; Takashima, Tsutomu; Kashiwagi, Shinichiro; Kawajiri, Hidemi; Tokunaga, Shinya; Tei, Seika; Nishimura, Shigehiko; Yamagata, Shigehito; Noda, Satoru; Nishimori, Takeo; Mizuyama, Yoko; Sunami, Takeshi; Ikeda, Katsumi; Ogawa, Yoshinari; Onoda, Naoyoshi; Ishikawa, Tetsuro; Kudoh, Shinzoh; Takada, Minoru; Hirakawa, Kosei

2017-01-01

Although the concurrent use of anthracycline-containing chemotherapy and taxane with trastuzumab are considered the treatment of choice for the primary systemic therapy of human epidermal growth factor receptor 2 (HER2)-overexpressing early breast cancer, non-anthracycline regimens, such as concurrent administration of docetaxel and carboplatin with trastuzumab, exhibited similar efficacies in a previous study. In addition, tri-weekly treatment with nanoparticle albumin-bound paclitaxel (nab-paclitaxel) resulted in significantly higher response rates and a favorable safety profile compared with standard paclitaxel for metastatic breast cancer patients in another phase III study. Based on these results, a phase I study of combination therapy with nab-paclitaxel, carboplatin and trastuzumab was planned, in order to estimate its efficacy and safety for HER2-overexpressing locally advanced breast cancer. The present study was designed to determine the dose-limiting toxicity (DLT), maximum tolerated dose and recommended dose of this combination treatment in women with HER2-overexpressing locally advanced breast cancer. The starting dose of nab-paclitaxel was 220 mg/m2 (level 1), and the dose was escalated to 260 mg/m2 (level 2). Nab-paclitaxel was administered with carboplatin (area under the curve, 6 mg/ml/min) and trastuzumab tri-weekly. A total of 6 patients were enrolled. Although no DLT was observed during the first cycle, 4 patients developed grade 4 thrombocytopenia, 2 had grade 4 neutropenia and 3 exhibited a grade 4 decrease in hemoglobin levels. In the present phase I study, although no patients experienced DLTs, this regimen was associated with severe hematological toxicities and it was not well tolerated. However, considering the high efficacy and lower risk of cardiotoxicity and secondary carcinogenesis with taxane, platinum and trastuzumab combination therapy, further evaluation of another regimen including weekly administration or a more accurate dose

Potential role of alpha-synuclein and metallothionein in lead-induced inclusion body formation.

PubMed

Zuo, Peijun; Qu, Wei; Cooper, Ryan N; Goyer, Robert A; Diwan, Bhalchandra A; Waalkes, Michael P

2009-09-01

Lead (Pb) produces aggresome-like inclusion bodies (IBs) in target cells as a toxic response. Our prior work shows metallothionein (MT) is required for this process. We used MT-I/II double knockout (MT-null) and parental wild-type (WT) cell lines to further explore the formation process of Pb-induced IBs. Unlike WT cells, MT-null cells did not form IBs after Pb exposure. Western blot of cytosol showed soluble MT protein in WT cells was lost during Pb exposure as IBs formed. Transfection of MT-I into MT-null cells allowed IBs formation after Pb exposure. Considering Pb-induced IBs may be like disease-related aggresomes, which often contain alpha-synuclein (Scna), we investigated Scna expression in cells capable (WT) and incapable (MT-null) of producing IBs after Pb exposure. Scna protein showed poor basal expression in MT-null cells. Pb exposure increased Scna expression only in WT cells. MT transfection increased Scna transcript to WT levels. In WT or MT-transfected MT-null cells, Pb-induced Scna expression rapidly increased and then decreased over 48 h as Pb-induced IBs were formed. A direct interaction between Scna and MT was confirmed ex vivo by antibody pulldown assay where the proteins coprecipitated with an antibody to MT. Pb exposure caused increased colocalization of MT and Scna proteins with time only in WT cells. In WT mice after chronic Pb exposure Scna was localized in renal cells containing forming IBs, whereas MT-null mice did not form IBs. Thus, Scna could be component of Pb-induced IBs and, with MT, may play a role in IBs formation.

Overexpression of Activin Receptor-like Kinase 7 in Breast Cancer Cells Is Associated with Decreased Cell Growth and Adhesion.

PubMed

Hu, Tingting; Su, Fengxi; Jiang, Wenguo; Dart, D Alwyn

2017-07-01

To examine the expression and function of activin receptor-like kinase 7 (ALK7) in breast cancer, its association with disease prognosis, and its impact on breast cancer cell function. A cohort of patients with breast cancer were examined for ALK7 expression in association with pathological and clinical aspects. In vitro cell assays of ALK7 were investigated using an expression plasmid. Overall higher levels of ALK7 transcripts were seen in the breast cancer samples vs. normal tissue. However, within the cancer cohort, lower levels of ALK7 transcript were associated with poor prognosis. Patients with lower expression of ALK7 also had shorter survival. Overexpression of ALK7 reduced proliferation and adhesion of breast cancer cells in vitro. We found that overexpressed ALK7 had complex effects on the MCF-7 cell sensitivity to chemotherapy drugs. Decreased expression of ALK7 in breast cancer is correlated with poor prognosis. ALK7 is a negative regulator of adhesion and proliferation of breast cancer cells. This suggests that ALK7 is a potential tumor suppressor in breast cancer. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Age-related changes of metallothionein 1/2 and metallothionein 3 expression in rat brain.

PubMed

Scudiero, Rosaria; Cigliano, Luisa; Verderame, Mariailaria

2017-01-01

Neurodegeneration is one of the main physiological consequences of aging on brain. Metallothioneins (MTs), low molecular weight, cysteine-rich proteins that bind heavy-metal ions and oxygen-free radicals, are commonly expressed in various tissues of mammals. MTs are involved in the regulation of cell proliferation and protection, and may be engaged in aging. Expression of the ubiquitous MTs (1 and 2) and the brain specific MT3 have been studied in many neurodegenerative disorders. The research results indicate that MTs may play important, although not yet fully known, roles in brain diseases; in addition, data lack the ability to identify the MT isoforms functionally involved. The aim of this study was to analyse the level of gene expression of selected MT isoforms during brain aging. By using real-time PCR analysis, we determined the MT1/2 and MT3 expression profiles in cerebral cortex and hippocampus of adolescent (2months), adult (4 and 8months), and middle-aged (16months) rats. We show that the relative abundance of all types of MT transcripts changes during aging in both hippocampus and cortex; the first effect is a generalized decrease in the content of MTs transcripts from 2- to 8-months-old rats. After passing middle age, at 16months, we observe a huge increase in MT3 transcripts in both cortical and hippocampal areas, while the MT1/2 mRNA content increases slightly, returning to the levels measured in adolescent rats. These findings demonstrate an age-related expression of the MT3 gene. A possible link between the increasing amount of MT3 in brain aging and its different metal-binding behaviour is discussed. Copyright © 2016 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Nmdmc overexpression extends Drosophila lifespan and reduces levels of mitochondrial reactive oxygen species

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

Yu, Suyeun; Jang, Yeogil; Paik, Donggi

NAD-dependent methylenetetrahydrofolate dehydrogenase-methenyltetrahydrofolate cyclohydrolase (NMDMC) is a bifunctional enzyme involved in folate-dependent metabolism and highly expressed in rapidly proliferating cells. However, Nmdmc physiological roles remain unveiled. We found that ubiquitous Nmdmc overexpression enhanced Drosophila lifespan and stress resistance. Interestingly, Nmdmc overexpression in the fat body was sufficient to increase lifespan and tolerance against oxidative stress. In addition, these conditions coincided with significant decreases in the levels of mitochondrial ROS and Hsp22 as well as with a significant increase in the copy number of mitochondrial DNA. These results suggest that Nmdmc overexpression should be beneficial for mitochondrial homeostasis and increasing lifespan.more » - Highlights: • Ubiquitous Nmdmc overexpression enhanced lifespan and stress tolerance. • Nmdmc overexpression in the fat body extended longevity. • Fat body-specific Nmdmc overexpression increased oxidative stress resistance. • Nmdmc overexpression decreased Hsp22 transcript levels and ROS. • Nmdmc overexpression increased mitochondrial DNA copy number.« less

Determination of dietary cadmium-induced metallothioneins in rabbit kidneys and cadmium in metallothioneins by anion-exchange high-performance liquid chromatography coupled with graphite furnace atomic absorption spectrometry.

PubMed

Peng, S; Shan, X Q; Zheng, Y; Jin, L Z; Xu, W B

1991-12-06

A rapid method is described for the determination of dietary cadmium-induced metallothioneins (MTs) in rabbit kidneys by anion-exchange high-performance liquid chromatography. Rabbit kidney MT-I and MT-II were eluted at ca. 15.0 and 18.8 min, respectively, from a DEAE-5PW anion-exchange column with a Tris-HCl buffer (0.01-0.25 M, pH 8.6) and detected by ultraviolet absorbance at 254 nm. A standard calibration curve was constructed using purified standard MT isoforms, which demonstrated an excellent linear correlation between UV absorbance peak heights and the amounts of MT isoforms. Feeding a dose of cadmium for some days resulted in an increase in MT concentrations in rabbit kidneys, but not in the livers. The cadmium concentrations in MT-I and MT-II elutions were determined by graphite furnace atomic absorption spectrometry. MT-I and MT-II showed some differences associated with the oral intake of cadmium. Dietary cadmium also caused zinc to accumulate in kidneys to some extent. The effects of dietary oleic acid on the synthesis of MTs were also studied. Based on the method of standard additions, the recovery of MTs exceeded 93% and replicated injection of samples yielded a relative standard deviation of 2.4% at an MT level of 280 micrograms/g.

The over-expression of the β2 catalytic subunit of the proteasome decreases homologous recombination and impairs DNA double-strand break repair in human cells.

PubMed

Collavoli, Anita; Comelli, Laura; Cervelli, Tiziana; Galli, Alvaro

2011-01-01

By a human cDNA library screening, we have previously identified two sequences coding two different catalytic subunits of the proteasome which increase homologous recombination (HR) when overexpressed in the yeast Saccharomyces cerevisiae. Here, we investigated the effect of proteasome on spontaneous HR and DNA repair in human cells. To determine if the proteasome has a role in the occurrence of spontaneous HR in human cells, we overexpressed the β2 subunit of the proteasome in HeLa cells and determined the effect on intrachromosomal HR. Results showed that the overexpression of β2 subunit decreased HR in human cells without altering the cell proteasome activity and the Rad51p level. Moreover, exposure to MG132 that inhibits the proteasome activity reduced HR in human cells. We also found that the expression of the β2 subunit increases the sensitivity to the camptothecin that induces DNA double-strand break (DSB). This suggests that the β2 subunit has an active role in HR and DSB repair but does not alter the intracellular level of the Rad51p.

The Over-expression of the β2 Catalytic Subunit of the Proteasome Decreases Homologous Recombination and Impairs DNA Double-Strand Break Repair in Human Cells

PubMed Central

Collavoli, Anita; Comelli, Laura; Cervelli, Tiziana; Galli, Alvaro

2011-01-01

By a human cDNA library screening, we have previously identified two sequences coding two different catalytic subunits of the proteasome which increase homologous recombination (HR) when overexpressed in the yeast Saccharomyces cerevisiae. Here, we investigated the effect of proteasome on spontaneous HR and DNA repair in human cells. To determine if the proteasome has a role in the occurrence of spontaneous HR in human cells, we overexpressed the β2 subunit of the proteasome in HeLa cells and determined the effect on intrachromosomal HR. Results showed that the overexpression of β2 subunit decreased HR in human cells without altering the cell proteasome activity and the Rad51p level. Moreover, exposure to MG132 that inhibits the proteasome activity reduced HR in human cells. We also found that the expression of the β2 subunit increases the sensitivity to the camptothecin that induces DNA double-strand break (DSB). This suggests that the β2 subunit has an active role in HR and DSB repair but does not alter the intracellular level of the Rad51p. PMID:21660142

CARTILAGE CONSTRUCTS ENGINEERED FROM CHONDROCYTES OVEREXPRESSING IGF-I IMPROVE THE REPAIR OF OSTEOCHONDRAL DEFECTS IN A RABBIT MODEL

PubMed Central

Madry, Henning; Kaul, Gunter; Zurakowski, David; Vunjak-Novakovic, Gordana; Cucchiarini, Magali

2015-01-01

Tissue engineering combined with gene therapy is a promising approach for promoting articular cartilage repair. Here, we tested the hypothesis that engineered cartilage with chondrocytes over expressing a human insulin-like growth factor I (IGF-I) gene can enhance the repair of osteochondral defects, in a manner dependent on the duration of cultivation. Genetically modified chondrocytes were cultured on biodegradable polyglycolic acid scaffolds in dynamic flow rotating bioreactors for either 10 or 28 d. The resulting cartilaginous constructs were implanted into osteochondral defects in rabbit knee joints. After 28 weeks of in vivo implantation, immunoreactivity to ß-gal was detectable in the repair tissue of defects that received lacZ constructs. Engineered cartilaginous constructs based on IGF-I-over expressing chondrocytes markedly improved osteochondral repair compared with control (lacZ) constructs. Moreover, IGF-I constructs cultivated for 28 d in vitro significantly promoted osteochondral repair vis-à-vis similar constructs cultivated for 10 d, leading to significantly decreased osteoarthritic changes in the cartilage adjacent to the defects. Hence, the combination of spatially defined overexpression of human IGF-I within a tissue-engineered construct and prolonged bioreactor cultivation resulted in most enhanced articular cartilage repair and reduction of osteoarthritic changes in the cartilage adjacent to the defect. Such genetically enhanced tissue engineering provides a versatile tool to evaluate potential therapeutic genes in vivo and to improve our comprehension of the development of the repair tissue within articular cartilage defects. Insights gained with additional exploration using this model may lead to more effective treatment options for acute cartilage defects. PMID:23588785

Neuroglobin Overexpression Inhibits AMPK Signaling and Promotes Cell Anabolism

PubMed Central

Cai, Bin; Li, Wenjun; Mao, XiaoOu; Winters, Ali; Ryou, Myoung-Gwi; Liu, Ran; Greenberg, David A.; Wang, Ning; Jin, Kunlin; Yang, Shao-Hua

2017-01-01

Neuroglobin (Ngb) is a recently discovered globin with preferential localization to neurons. Growing evidence indicates that Ngb has distinct physiological functions separate from the oxygen storage and transport roles of other globins, such as hemoglobin and myoglobin. We found increased ATP production and decreased glycolysis in Ngb-overexpressing immortalized murine hippocampal cell line (HT-22), in parallel with inhibition of AMPK signaling and activation of acetyl-CoA carboxylase (ACC). In addition, lipid and glycogen content was increased in Ngb-overexpressing HT-22 cells. AMPK signaling was also inhibited in brain and heart from Ngb-overexpressing transgenic mice. Although Ngb overexpression did not change glycogen content in whole brain, glycogen synthase was activated in cortical neurons of Ngb overexpressing mouse brain and Ngb overexpression primary neurons. Moreover, lipid and glycogen content was increased in hearts derived from Ngb-overexpressing mice. These findings suggest that Ngb functions as a metabolic regulator and enhances cellular anabolism through the inhibition of AMPK signaling. PMID:25616953

Neuroglobin Overexpression Inhibits AMPK Signaling and Promotes Cell Anabolism.

PubMed

Cai, Bin; Li, Wenjun; Mao, XiaoOu; Winters, Ali; Ryou, Myoung-Gwi; Liu, Ran; Greenberg, David A; Wang, Ning; Jin, Kunlin; Yang, Shao-Hua

2016-03-01

Neuroglobin (Ngb) is a recently discovered globin with preferential localization to neurons. Growing evidence indicates that Ngb has distinct physiological functions separate from the oxygen storage and transport roles of other globins, such as hemoglobin and myoglobin. We found increased ATP production and decreased glycolysis in Ngb-overexpressing immortalized murine hippocampal cell line (HT-22), in parallel with inhibition of AMP-activated protein kinase (AMPK) signaling and activation of acetyl-CoA carboxylase (ACC). In addition, lipid and glycogen content was increased in Ngb-overexpressing HT-22 cells. AMPK signaling was also inhibited in the brain and heart from Ngb-overexpressing transgenic mice. Although Ngb overexpression did not change glycogen content in whole brain, glycogen synthase was activated in cortical neurons of Ngb-overexpressing mouse brain and Ngb overexpression primary neurons. Moreover, lipid and glycogen content was increased in hearts derived from Ngb-overexpressing mice. These findings suggest that Ngb functions as a metabolic regulator and enhances cellular anabolism through the inhibition of AMPK signaling.

Ribozyme-mediated cleavage of c-fos mRNA reduces gene expression of DNA synthesis enzymes and metallothionein.

PubMed Central

Scanlon, K J; Jiao, L; Funato, T; Wang, W; Tone, T; Rossi, J J; Kashani-Sabet, M

1991-01-01

The c-fos gene product Fos has been implicated in many cellular processes, including signal transduction, DNA synthesis, and resistance to antineoplastic agents. A fos ribozyme (catalytic RNA) was designed to evaluate the effects of suppressing Fos protein synthesis on expression of enzymes involved in DNA synthesis, DNA repair, and drug resistance. DNA encoding the fos ribozyme (fosRb) was cloned into the pMAMneo expression plasmid, and the resultant vector was transfected into A2780DDP cells resistant to the chemotherapeutic agent cisplatin. The parental drug-sensitive A2780S cells were transfected with the pMMV vector containing the c-fos gene. Morphological alterations were accompanied by significant changes in pharmacological sensitivity in both c-fos- and fosRb-transfected cells. pMAMneo fosRb transfectants revealed decreased c-fos gene expression, concomitant with reduced thymidylate (dTMP) synthase, DNA polymerase beta, topoisomerase I, and metallothionein IIA mRNAs. In contrast, c-myc expression was elevated after fos ribozyme action. Insertion of a mutant ribozyme, mainly capable of antisense activity, into A2780DDP cells resulted in smaller reductions in c-fos gene expression and in cisplatin resistance than the active ribozyme. These studies establish a role for c-fos in drug resistance and in mediating DNA synthesis and repair processes by modulating expression of genes such as dTMP synthase, DNA polymerase beta, and topoisomerase I. These studies also suggest the utility of ribozymes in the analysis of cellular gene expression. Images PMID:1660142

Zinc or copper deficiency-induced impaired inflammatory response to brain trauma may be caused by the concomitant metallothionein changes.

PubMed

Penkowa, M; Giralt, M; Thomsen, P S; Carrasco, J; Hidalgo, J

2001-04-01

The role of zinc- and copper-deficient diets on the inflammatory response to traumatic brain injury (TBI) has been evaluated in adult rats. As expected, zinc deficiency decreased food intake and body weight gain, and the latter effect was higher than that observed in pair-fed rats. In noninjured brains, zinc deficiency only affected significantly lectin (increasing) and glial fibrillary acidic protein (GFAP) and Cu,Zn-superoxide dismutase (Cu,Zn-SOD) (decreasing) immunoreactivities (irs). In injured brains, a profound gliosis was observed in the area surrounding the lesion, along with severe damage to neurons as indicated by neuron specific enolase (NSE) ir, and the number of cells undergoing apoptosis (measured by TUNEL) was dramatically increased. Zinc deficiency significantly altered brain response to TBI, potentiating the microgliosis and reducing the astrogliosis, while increasing the number of apoptotic cells. Metallothioneins (MTs) are important zinc- and copper-binding proteins in the CNS, which could influence significantly the brain response to TBI because of their putative roles in metal homeostasis and antioxidant defenses. MT-I+II expression was dramatically increased by TBI, and this response was significantly blunted by zinc deficiency. The MT-III isoform was moderately increased by both TBI and zinc deficiency. TBI strongly increased oxidative stress levels, as demonstrated by malondialdehyde (MDA), protein tyrosine nitration (NITT), and nuclear factor kappaB (NF-kappaB) levels irs, all of which were potentiated by zinc deficiency. Further analysis revealed unbalanced expression of prooxidant and antioxidant proteins besides MT, since the levels of inducible nitric oxide synthase (iNOS) and Cu,Zn-SOD were increased and decreased, respectively, by zinc deficiency. All these effects were attributable to zinc deficiency, since pair-fed rats did not differ from normally fed rats. In general, copper deficiency caused a similar pattern of responses

Overexpression of stress-inducible OsBURP16, the β subunit of polygalacturonase 1, decreases pectin content and cell adhesion and increases abiotic stress sensitivity in rice

PubMed Central

Liu, Huanhuan; Ma, Yan; Chen, Na; Guo, Siyi; Liu, Huili; Guo, Xiaoyu; Chong, Kang; Xu, Yunyuan

2014-01-01

Polygalacturonase (PG), one of the hydrolases responsible for cell wall pectin degradation, is involved in organ consenescence and biotic stress in plants. PG1 is composed of a catalytic subunit, PG2, and a non-catalytic PG1β subunit. OsBURP16 belongs to the PG1β-like subfamily of BURP-family genes and encodes one putative PG1β subunit precursor in rice (Oryza sativa L.). Transcription of OsBURP16 is induced by cold, salinity and drought stresses, as well as by abscisic acid (ABA) treatment. Analysis of plant survival rates, relative ion leakage rates, accumulation levels of H2O2 and water loss rates of leaves showed that overexpression of OsBURP16 enhanced sensitivity to cold, salinity and drought stresses compared with controls. Young leaves of Ubi::OsBURP16 transgenic plants showed reduced cell adhesion and increased cuticular transpiration rate. Mechanical strength measurement of Ubi::OsBURP16 plants showed that reduced force was required to break leaves as compared with wild type. Transgenic rice showed enhanced PG activity and reduced pectin content. All these results suggested that overexpression of OsBURP16 caused pectin degradation and affected cell wall integrity as well as transpiration rate, which decreased tolerance to abiotic stresses. The cell wall is a barrier against biotic and abiotic stresses. Overexpression of stress-inducible OsBURP16, the beta-subunit of polygalacturonase 1, decreases pectin contents and cell adhesion in rice. Analyses of plant survival, ion leakage, H2O2 levels, and leaf water loss showed that these effects of overexpression were accompanied by enhanced sensitivity to cold, salinity and drought compared to the wild-type. Our data therefore provide new information on links between polygalacturonase activity and abiotic stress resistance in rice. PMID:24237159

Relative roles of synthesis and degradation in regulating metallothionein accretion

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

Laurin, D.E.

1989-01-01

Decay kinetics of {sup 35}S-cysteine (cys) in metallothionein (MT) were used to simultaneously measure rates of MT synthesis and degradation in a HD11 chicken-macrophage cell-line. A reverse-phase (RP) high-performance liquid-chromatography procedure was used to purify 2 MT-isoforms from cytosols with approximately 94% purity. The medium that the macrophages were incubated in was validated to ensure that it contained enough unlabeled cys to adequately chase {sup 35}S-cys released by the degradation of labeled protein. The addition of Zn{sup 2+} and unlabeled cys to the medium did not change the fractional-rates of MT synthesis (FRS) and degradation (FRD). These measurements were alsomore » validated by showing that the measured fractional-rate of MT accretion closely approximated the difference between FRS and FRD. When macrophages were incubated in medium supplemented with 50 or 25 {mu}M Zn{sup 2+} the absolute-rate of MT synthesis (ARS) and FRD increased and decreases, respectively. When macrophages were incubated in medium supplemented with 20 or 10 {mu}M Cd{sup 2+}, the ARS increased but the FDR was not changed.« less

Overexpressed human heme Oxygenase-1 decreases adipogenesis in pigs and porcine adipose-derived stem cells.

PubMed

Park, Eun Jung; Koo, Ok Jae; Lee, Byeong Chun

2015-11-27

Adipose-derived mesenchymal stem cells (ADSC) are multipotent, which means they are able to differentiate into several lineages in vivo and in vitro under proper conditions. This indicates it is possible to determine the direction of differentiation of ADSC by controlling the microenvironment. Heme oxygenase 1 (HO-1), a type of antioxidant enzyme, attenuates adipogenicity and obesity. We produced transgenic pigs overexpressing human HO-1 (hHO-1-Tg), and found that these animals have little fatty tissue when autopsied. To determine whether overexpressed human HO-1 suppresses adipogenesis in pigs, we analyzed body weight increases of hHO-1-Tg pigs and wild type (WT) pigs of the same strain, and induced adipogenic differentiation of ADSC derived from WT and hHO-1-Tg pigs. The hHO-1-Tg pigs had lower body weights than WT pigs from 16 weeks of age until they died. In addition, hHO-1-Tg ADSC showed reduced adipogenic differentiation and expression of adipogenic molecular markers such as PPARγ and C/EBPα compared to WT ADSC. These results suggest that HO-1 overexpression reduces adipogenesis both in vivo and in vitro, which could support identification of therapeutic targets of obesity and related metabolic diseases. Copyright © 2015 Elsevier Inc. All rights reserved.

Deletion of metallothionein exacerbates intermittent hypoxia-induced oxidative and inflammatory injury in aorta.

PubMed

Zhou, Shanshan; Wang, Yonggang; Tan, Yi; Cai, Xiaohong; Cai, Lu; Cai, Jun; Zheng, Yang

2014-01-01

The present study was to explore the effect of metallothionein (MT) on intermittent hypoxia (IH) induced aortic pathogenic changes. Markers of oxidative damages, inflammation, and vascular remodeling were observed by immunohistochemical staining after 3 days and 1, 3, and 8 weeks after IH exposures. Endogenous MT was induced after 3 days of IH but was significantly decreased after 8 weeks of IH. Compared with the wild-type mice, MT knock-out mice exhibited earlier and more severe pathogenic changes of oxidative damages, inflammatory responses, and cellular apoptosis, as indicated by the significant accumulation of collagen, increased levels of connective tissue growth factor, transforming growth factor β1, tumor necrosis factor-alpha, vascular cell adhesion molecule 1,3-nitrotyrosine, and 4-hydroxy-2-nonenal in the aorta. These findings suggested that chronic IH may lead to aortic damages characterized by oxidative stress and inflammation, and MT may play a pivotal role in the above pathogenesis process.

Cadmium modulates adipocyte functions in metallothionein-null mice

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

Kawakami, Takashige; Nishiyama, Kaori; Kadota, Yoshito

2013-11-01

Our previous study has demonstrated that exposure to cadmium (Cd), a toxic heavy metal, causes a reduction of adipocyte size and the modulation of adipokine expression. To further investigate the significance of the Cd action, we studied the effect of Cd on the white adipose tissue (WAT) of metallothionein null (MT{sup −/−}) mice, which cannot form atoxic Cd–MT complexes and are used for evaluating Cd as free ions, and wild type (MT{sup +/+}) mice. Cd administration more significantly reduced the adipocyte size of MT{sup −/−} mice than that of MT{sup +/+} mice. Cd exposure also induced macrophage recruitment to WATmore » with an increase in the expression level of Ccl2 (MCP-1) in the MT{sup −/−} mice. The in vitro exposure of Cd to adipocytes induce triglyceride release into culture medium, decrease in the expression levels of genes involved in fatty acid synthesis and lipid hydrolysis at 24 h, and at 48 h increase in phosphorylation of the lipid-droplet-associated protein perilipin, which facilitates the degradation of stored lipids in adipocytes. Therefore, the reduction in adipocyte size by Cd may arise from an imbalance between lipid synthesis and lipolysis. In addition, the expression levels of leptin, adiponectin and resistin decreased in adipocytes. Taken together, exposure to Cd may induce unusually small adipocytes and modulate the expression of adipokines differently from the case of physiologically small adipocytes, and may accelerate the risk of developing insulin resistance and type 2 diabetes. - Highlights: • Cd causes a marked reduction in adipocyte size in MT-null mice. • Cd enhances macrophage migration into adipose tissue and disrupt adipokine secretion. • MT gene alleviates Cd-induced adipocyte dysfunctions. • Cd enhances the degradation of stored lipids in adipocytes, mediated by perilipin. • Cd induces unusually small adipocytes and the abnormal expression of adipokines.« less

Gene Overexpression/Suppression Analysis of Candidate Virulence Factors of Candida albicans▿

PubMed Central

Fu, Yue; Luo, Guanpingsheng; Spellberg, Brad J.; Edwards, John E.; Ibrahim, Ashraf S.

2008-01-01

We developed a conditional overexpression/suppression genetic strategy in Candida albicans to enable simultaneous testing of gain or loss of function in order to identify new virulence factors. The strategy involved insertion of a strong, tetracycline-regulated promoter in front of the gene of interest. To validate the strategy, a library of genes encoding glycosylphosphatidylinositol (GPI)-anchored surface proteins was screened for virulence phenotypes in vitro. During the screening, overexpression of IFF4 was found to increase the adherence of C. albicans to plastic and to human epithelial cells, but not endothelial cells. Consistent with the in vitro results, IFF4 overexpression modestly increased the tissue fungal burden during murine vaginal candidiasis. In addition to the in vitro screening tests, IFF4 overexpression was found to increase C. albicans susceptibility to neutrophil-mediated killing. Furthermore, IFF4 overexpression decreased the severity of hematogenously disseminated candidiasis in normal mice, but not in neutropenic mice, again consistent with the in vitro phenotype. Overexpression of 12 other GPI proteins did not affect normal GPI protein cell surface accumulation, demonstrating that the overexpression strategy did not affect the cell capacity for making such proteins. These data indicate that the same gene can increase or decrease candidal virulence in distinct models of infection, emphasizing the importance of studying virulence genes in different anatomical contexts. Finally, these data validate the use of a conditional overexpression/suppression genetic strategy to identify candidal virulence factors. PMID:18178776

Expression of metallothionein and α-tubulin in heavy metal-tolerant Anopheles gambiae sensu stricto (Diptera: Culicidae)

PubMed Central

Mireji, Paul O.; Keating, Joseph; Hassanali, Ahmed; Impoinvil, Daniel E.; Mbogo, Charles M.; Njeri, Martha; Nyambaka, Hudson; Kenya, Eucharia; Githure, John I; Beier, John C.

2009-01-01

Anopheles mosquitoes have been shown to adapt to heavy metals in their natural habitats. In this study we explored the possibility of using Anopheles gambiae sensu stricto as bio-reporters for environmental heavy metal pollution through expressions of their metal responsive metallothionein and α-tubulin genes. The study was undertaken with third instar larvae after selection by cadmium, copper, or lead at LC30 through five successive generations. Expression levels were determined in the fifth generation by semi quantitative RT-PCR on the experimental and control populations. The data were analyzed using one-way ANOVA. The highest metallothionein (F3, 11= 4.574, P = 0.038) and α-tubulin (F3,11= 12.961, P = 0.002) responses were observed in cadmium-tolerant treatments. There was significantly higher expression of metallothionein in cadmium or copper treatments relative to the control (P = 0.012), and in cadmium than in lead treatments (P = 0.044). Expressions of α-tubulin were significantly higher in cadmium than in control treatments (P = 0.008). These results demonstrate capacity of An. gambiae s.s. to develop tolerance to increased levels of heavy metal challenge. The results also confirm the potential of heavy metal responsive genes in mosquitoes as possible bio-indicators of heavy metal environmental pollution. How the tolerance and expressions relate to An. gambiae s.s. fitness and vectorial capacity in the environment remains to be elucidated. PMID:19735939

Metallothionein--a promising tool for cancer diagnostics.

PubMed

Krizkova, S; Fabrik, I; Adam, V; Hrabeta, J; Eckschlager, T; Kizek, R

2009-01-01

The latest research outcomes indicate that metallothionein (MT) levels in peripheral blood and serum from cancer patients can provide many interesting information about type or clinical stage of the disease, or response to therapy. MT plays a key role in transport of essential heavy metals, detoxification of toxic metals and protection of cells against oxidation stress. Serum MT levels of cancer patients are three times higher than control patients (0.5 microM). The elevated MT levels in cancer cells are probably related to their increased proliferation and protection against apoptosis. Automated electrochemical detection of MT allows its serial analysis in a very small volume with excellent sensitivity, reliability and reproducibility and therefore it can be considered as a new tool for cancer diagnosis (Fig. 4, Ref. 55). Full Text (Free, PDF) www.bmj.sk.

Mammalian Metallothionein-2A and Oxidative Stress

PubMed Central

Ling, Xue-Bin; Wei, Hong-Wei; Wang, Jun; Kong, Yue-Qiong; Wu, Yu-You; Guo, Jun-Li; Li, Tian-Fa; Li, Ji-Ke

2016-01-01

Mammalian metallothionein-2A (MT2A) has received considerable attention in recent years due to its crucial pathophysiological role in anti-oxidant, anti-apoptosis, detoxification and anti-inflammation. For many years, most studies evaluating the effects of MT2A have focused on reactive oxygen species (ROS), as second messengers that lead to oxidative stress injury of cells and tissues. Recent studies have highlighted that oxidative stress could activate mitogen-activated protein kinases (MAPKs), and MT2A, as a mediator of MAPKs, to regulate the pathogenesis of various diseases. However, the molecule mechanism of MT2A remains elusive. A deeper understanding of the functional, biochemical and molecular characteristics of MT2A would be identified, in order to bring new opportunities for oxidative stress therapy. PMID:27608012

Overexpression of MutL homolog 1 and MutS homolog 2 proteins have reversed prognostic implications for stage I-II colon cancer patients.

PubMed

Huang, Shih-Chiang; Huang, Shiu-Feng; Chen, Ya-Ting; Chang, Yu; Chiu, Yu-Ting; Chang, Il-Chi; Wu, Hong-Dar Isaac; Chen, Jinn-Shiun

2017-02-01

The outcome of colon cancer patients without lymph node metastasis is heterogeneous. Searching for new prognostic markers is warranted. One hundred twenty stage I-II colon cancer patients who received complete surgical excision during 1995-2004 were selected for this biomarker study. Immunohistochemical method was used to assess p53, epidermal growth factor receptor, MLH1, and MSH2 status. KRAS mutation was examined by direct sequencing. Thirty three patients (27.5%) developed metachronous metastasis during follow up. By multivariate analysis, only female gender (p = 0.03), high serum carcinoembryonic antigen (CEA) level (≧5 ng/ml) (p = 0.04), and MLH1 overexpression (p = 0.003) were associated with the metastasis group. The 5-year-survival rate were also significantly lower for female gender (71.7% versus 88.9%, p = 0.025), high CEA level (64.9% versus 92.4%, p < 0.001), and MLH1 overexpression (77.5% versus 94.4%, p = 0.039). In contrast, MSH2 overexpression was associated with better survival, 95.1% versus 75.5% (p = 0.024). The reversed prognostic implications in the overexpression of MLH1 and MSH2 for stage I-II colon cancer patients is a novel finding and worthy of further confirmation. Copyright © 2017 Chang Gung University. Published by Elsevier B.V. All rights reserved.

Overexpression of B-cell lymphoma 6 alters gene expression profile in a myeloma cell line and is associated with decreased DNA damage response.

PubMed

Tahara, Kenichi; Takizawa, Makiko; Yamane, Arito; Osaki, Yohei; Ishizaki, Takuma; Mitsui, Takeki; Yokohama, Akihiko; Saitoh, Takayuki; Tsukamoto, Norifumi; Matsumoto, Morio; Murakami, Hirokazu; Nojima, Yoshihisa; Handa, Hiroshi

2017-08-01

B-cell lymphoma 6 (BCL6) attenuates DNA damage response (DDR) through gene repression and facilitates tolerance to genomic instability during immunoglobulin affinity maturation in germinal center (GC) B cells. Although BCL6 expression is repressed through normal differentiation of GC B cells into plasma cells, a recent study showed the ectopic expression of BCL6 in primary multiple myeloma (MM) cells. However, the functional roles of BCL6 in MM cells are largely unknown. Here, we report that overexpression of BCL6 in a MM cell line, KMS12PE, induced transcriptional repression of ataxia telangiectasia mutated (ATM), a DDR signaling kinase, which was associated with a reduction in γH2AX formation after DNA damage. In contrast, transcription of known targets of BCL6 in GC B cells was not affected, suggesting a cell type-specific function of BCL6. To further investigate the effects of BCL6 overexpression on the MM cell line, we undertook mRNA sequence analysis and found an upregulation in the genomic mutator activation-induced cytidine deaminase (AID) with alteration in the gene expression profile, which is suggestive of de-differentiation from plasma cells. Moreover, interleukin-6 exposure to KMS12PE led to upregulation of BCL6 and AID, downregulation of ATM, and attenuation of DDR, which were consistent with the effects of BCL6 overexpression in this MM cell line. Taken together, these results indicated that overexpression of BCL6 alters gene expression profile and confers decreased DDR in MM cells. This phenotypic change could be reproduced by interleukin-6 stimulation, suggesting an important role of external stimuli in inducing genomic instability, which is a hallmark of MM cells. © 2017 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

Concurrent overexpression of ornithine decarboxylase and spermidine/spermine N(1)-acetyltransferase further accelerates the catabolism of hepatic polyamines in transgenic mice.

PubMed Central

Suppola, S; Heikkinen, S; Parkkinen, J J; Uusi-Oukari, M; Korhonen, V P; Keinänen, T; Alhonen, L; Jänne, J

2001-01-01

We have generated a hybrid transgenic mouse line overexpressing both ornithine decarboxylase (ODC) and spermidine/spermine N(1)-acetyltransferase (SSAT) under the control of the mouse metallothionein (MT) I promoter. In comparison with singly transgenic animals overexpressing SSAT, the doubly transgenic mice unexpectedly displayed much more striking signs of activated polyamine catabolism, as exemplified by a massive putrescine accumulation and an extreme reduction of hepatic spermidine and spermine pools. Interestingly, the profound depletion of the higher polyamines in the hybrid animals occurred in the presence of strikingly high ODC activity and tremendous putrescine accumulation. Polyamine catabolism in the doubly transgenic mice could be enhanced further by administration of zinc or the polyamine analogue N(1),N(11)-diethylnorspermine. In tracer experiments with [(14)C]spermidine we found that, in comparison with syngenic animals, both MT-ODC and MT-SSAT mice possessed an enhanced efflux mechanism for hepatic spermidine. In the MT-ODC animals this mechanism apparently operated in the absence of measurable SSAT activity. In the hybrid animals, spermidine efflux was stimulated further in comparison with the singly transgenic animals. In spite of a dramatic accumulation of putrescine and a profound reduction of the spermidine and spermine pools, only marginal changes were seen in the level of ODC antizyme. Even though the hybrid animals showed no liver or other organ-specific overt toxicity, except an early and permanent loss of hair, their life span was greatly reduced. These results can be understood from the perspective that catabolism is the overriding regulatory mechanism in the metabolism of the polyamines and that, even under conditions of severe depletion of spermidine and spermine, extremely high tissue pools of putrescine are not driven further to replenish the pools of the higher polyamines. PMID:11513732

Overexpression of RBM5 induces autophagy in human lung adenocarcinoma cells.

PubMed

Su, Zhenzhong; Wang, Ke; Li, Ranwei; Yin, Jinzhi; Hao, Yuqiu; Lv, Xuejiao; Li, Junyao; Zhao, Lijing; Du, Yanwei; Li, Ping; Zhang, Jie

2016-02-29

Dysfunctions in autophagy and apoptosis are closely interacted and play an important role in cancer development. RNA binding motif 5 (RBM5) is a tumor suppressor gene, which inhibits tumor cells' growth and enhances chemosensitivity through inducing apoptosis in our previous studies. In this study, we investigated the relationship between RBM5 overexpression and autophagy in human lung adenocarcinoma cells. Human lung adenocarcinoma cancer (A549) cells were cultured in vitro and were transiently transfected with a RBM5 expressing plasmid (GV287-RBM5) or plasmid with scrambled control sequence. RBM5 expression was determined by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and Western blot. Intracellular LC-3 I/II, Beclin-1, lysosome associated membrane protein-1 (LAMP1), Bcl-2, and NF-κB/p65 protein levels were detected by Western blot. Chemical staining with monodansylcadaverine (MDC) and acridine orange (AO) was applied to detect acidic vesicular organelles (AVOs). The ultrastructure changes were observed under transmission electron microscope (TEM). Then, transplanted tumor models of A549 cells on BALB/c nude mice were established and treated with the recombinant plasmids carried by attenuated Salmonella to induce RBM5 overexpression in tumor tissues. RBM5, LC-3, LAMP1, and Beclin1 expression was determined by immunohistochemistry staining in plasmids-treated A549 xenografts. Our study demonstrated that overexpression of RBM5 caused an increase in the autophagy-related proteins including LC3-I, LC3-II, LC3-II/LC3-I ratio, Beclin1, and LAMP1 in A549 cells. A large number of autophagosomes with double-membrane structure and AVOs were detected in the cytoplasm of A549 cells transfected with GV287-RBM5 at 24 h. We observed that the protein level of NF-κB/P65 was increased and the protein level of Bcl-2 decreased by RBM5 overexpression. Furthermore, treatment with an autophagy inhibitor, 3-MA, enhanced RBM5-induced cell death and

Overexpression of CB2 cannabinoid receptors decreased vulnerability to anxiety and impaired anxiolytic action of alprazolam in mice.

PubMed

García-Gutiérrez, María S; Manzanares, Jorge

2011-01-01

Mice overexpressing CB2r (CB2xP) were exposed to open field (OF), light-dark box (LDB) and elevated plus maze (EPM) tests. Corticotropin-releasing factor (CRF) and pro-opiomelanocortin (POMC) mRNA were measured in paraventricular (PVN) and arcuate (ARC) nuclei of the hypothalamus after 30 minutes of restraint stress (RS). Anxiolytic effects of alprazolam (45 or 70 µg/kg, ip) were evaluated. GABA(A)α(2) and GABA(A)γ(2) mRNA were measured in the hippocampus (HIPP) and amygdala (AMY) of CB2xP and wild type (WT) mice. No differences were observed in the total distance travelled by CB2xP and WT mice in OF. Central and peripheral distances travelled significantly increased and decreased in CB2xP mice. Overexpression of CB2r reduced anxiety-like behaviours in LDB and EPM. In WT mice, RS increased CRF (82%) and POMC (42%) mRNA in the PVN and ARC nuclei, respectively. In CB2xP mice, RS also increased POMC (22%) mRNA in the ARC nucleus, but had no effect on CRF mRNA in the PVN nucleus. Administration of alprazolam was without effect in CB2xP mice. An increase of GABA(A)α(2) and GABA(A)γ(2) mRNA in the hippocampus and amygdala of CB2xP mice was observed. Our findings revealed that increased expression of CB2r significantly reduced anxiogenic-related behaviours, modified the response to stress and impaired the action of anxiolytic drugs.

A Simple Metallothionein-Based Biosensor for Enhanced Detection of Arsenic and Mercury

PubMed Central

Irvine, Gordon W.; Tan, Swee Ngin; Stillman, Martin J.

2017-01-01

Metallothioneins (MTs) are a family of cysteine-rich proteins whose biological roles include the regulation of essential metal ions and protection against the harmful effects of toxic metals. Due to its high affinity for many toxic, soft metals, recombinant human MT isoform 1a was incorporated into an electrochemical-based biosensor for the detection of As3+ and Hg2+. A simple design was chosen to maximize its potential in environmental monitoring and MT was physically adsorbed onto paper discs placed on screen-printed carbon electrodes (SPCEs). This system was tested with concentrations of arsenic and mercury typical of contaminated water sources ranging from 5 to 1000 ppb. The analytical performance of the MT-adsorbed paper discs on SPCEs demonstrated a greater than three-fold signal enhancement and a lower detection limit compared to blank SPCEs, 13 ppb for As3+ and 45 ppb for Hg2+. While not being as low as some of the recommended drinking water limits, the sensitivity of the simple MT-biosensor would be potentially useful in monitoring of areas of concern with a known contamination problem. This paper describes the ability of the metal binding protein metallothionein to enhance the effectiveness of a simple, low-cost electrochemical sensor. PMID:28335390

GENETIC BACKGROUND BUT NOT METALLOTHIONEIN PHENOTYPE DICTATES SENSITIVITY TO CADMIUM-INDUCED TESTICULAR INJURY IN MICE

EPA Science Inventory

Genetic Background but not Metallothionein Phenotype Dictates Sensitivity to
Cadmium-Induced Testicular Injury in Mice

Jie Liu1,2, Chris Corton3, David J. Dix4, Yaping Liu1, Michael P. Waalkes2
and Curtis D. Klaassen1

ABSTRACT

Parenteral administrati...

Hand1 overexpression inhibits medulloblastoma metastasis

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

Asuthkar, Swapna; Guda, Maheedhara R.; Martin, Sarah E.

2016-08-19

Medulloblastoma (MB) is the most frequent malignant pediatric brain tumor. Current treatment includes surgery, radiation and chemotherapy. However, ongoing treatment in patients is further classified according to the presence or absence of metastasis. Since metastatic medulloblastoma are refractory to current treatments, there is need to identify novel biomarkers that could be used to reduce metastatic potential, and more importantly be targeted therapeutically. Previously, we showed that ionizing radiation-induced uPAR overexpression is associated with increased accumulation of β-catenin in the nucleus. We further demonstrated that uPAR protein act as cytoplasmic sequestration factor for a novel basic helix-loop-helix transcription factor, Hand1. Amongmore » the histological subtypes classical and desmoplastic subtypes account for the majority while large cell/anaplastic variant is most commonly associated with metastatic disease. In this present study using immunohistochemical approach and patient data mining for the first time, we demonstrated that Hand1 expression is observed to be downregulated in all the subtypes of medulloblastoma. Previously we showed that Hand1 overexpression regulated medulloblastoma angiogenesis and here we investigated the role of Hand1 in the context of Epithelial-Mesenchymal Transition (EMT). Moreover, UW228 and D283 cells overexpressing Hand1 demonstrated decreased-expression of mesenchymal markers (N-cadherin, β-catenin and SOX2); metastatic marker (SMA); and increased expression of epithelial marker (E-cadherin). Strikingly, human pluripotent stem cell antibody array showed that Hand1 overexpression resulted in substantial decrease in pluripotency markers (Nanog, Oct3/4, Otx2, Flk1) suggesting that Hand1 expression may be essential to attenuate the EMT and our findings underscore a novel role for Hand1 in medulloblastoma metastasis. - Highlights: • Hand1 expression is downregulated in Medulloblastoma. • Hand1 over

Persistent IGF-I overexpression in skeletal muscle transiently enhances DNA accretion and growth.

PubMed

Fiorotto, Marta L; Schwartz, Robert J; Delaughter, M Craig

2003-01-01

Adult transgenic mice with muscle-specific overexpression of insulin-like growth factor (IGF)-I have enlarged skeletal muscles. In this study, we; 1) characterized the development of muscle hypertrophy with respect to fiber type, age, and sex; 2) determined the primary anabolic process responsible for development of hypertrophy; and 3) identified secondary effects of muscle hypertrophy on body composition. Transgene expression increased with age and was present only in fibers expressing type IIB fast myosin heavy chain. Muscle masses were greater by 5 wk of age, and by 10 wk of age the differences were maximal despite continued transgene expression. Total DNA and RNA contents of the gastrocnemius muscle were greater for transgenic mice than for nontransgenic littermates. The differences were maximal by 5 wk of age and preceded the increase in protein mass. The accelerated protein deposition ceased when the protein/DNA ratio attained the same value as in nontransgenic controls. Despite localization of IGF-I expression to muscle without changes in plasma IGF-I concentrations, genotype also modified the normal age and sex effects on fat deposition and organ growth. Thus, enhanced DNA accretion by IGF-I was primarily responsible for stimulating muscle growth. In turn, secondary effects on body composition were incurred that likely reflect the impact of muscle mass on whole body metabolism.

AgFNS overexpression increase apigenin and decrease anthocyanins in petioles of transgenic celery.

PubMed

Tan, Guo-Fei; Ma, Jing; Zhang, Xin-Yue; Xu, Zhi-Sheng; Xiong, Ai-Sheng

2017-10-01

Apigenin and anthocyanin biosyntheses share common precursors in plants. Flavone synthase (FNS) converts naringenin into apigenin in higher plants. Celery is an important edible and medical vegetable crop that contains apigenin in its tissues. However, the effect of high AgFNS gene expression on the apigenin and anthocyanins contents of purple celery remains to be elucidated. In this study, the AgFNS gene was cloned from purple celery ('Nanxuan liuhe purple celery') and overexpressed in this purple celery to determine its influence on anthocyanins and apigenin contents. Results showed that the AgFNS gene was 1068bp, which encodes 355 amino acid residues. Evolution analysis showed that the AgFNS protein belongs to the FSN I type. In AgFNS transgenic celery, the anthocyanins content in petioles was lower than that wild-type celery plants. Apigenin content increased in the petioles of AgFNS transgenic celery. The transcript levels of the AgPAL, AgC4H, AgCHS, and AgCHI genes were up-regulated, whereas those of the AgF3H, AgF3'H, AgDFR, AgANS, and Ag3GT genes were down-regulated in the petioles of AgFNS transgenic plants compared with wild-type celery plants. This work provides basic knowledge about the function of the AgFNS gene in the anthocyanin and apigenin biosyntheses of celery. Copyright © 2017 Elsevier B.V. All rights reserved.

CARMA3 is overexpressed in colon cancer and regulates NF-{kappa}B activity and cyclin D1 expression

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

Miao, Zhifeng; Zhao, Tingting; Wang, Zhenning

2012-09-07

Highlights: Black-Right-Pointing-Pointer CARMA3 expression is elevated in colon cancers. Black-Right-Pointing-Pointer CARMA3 promotes proliferation and cell cycle progression in colon cancer cells. Black-Right-Pointing-Pointer CARMA3 upregulates cyclinD1 through NF-{kappa}B activation. -- Abstract: CARMA3 was recently reported to be overexpressed in cancers and associated with the malignant behavior of cancer cells. However, the expression of CARMA3 and its biological roles in colon cancer have not been reported. In the present study, we analyzed the expression pattern of CARMA3 in colon cancer tissues and found that CARMA3 was overexpressed in 30.8% of colon cancer specimens. There was a significant association between CARMA3 overexpression andmore » TNM stage (p = 0.0383), lymph node metastasis (p = 0.0091) and Ki67 proliferation index (p = 0.0035). Furthermore, knockdown of CARMA3 expression in HT29 and HCT116 cells with high endogenous expression decreased cell proliferation and cell cycle progression while overexpression of CARMA3 in LoVo cell line promoted cell proliferation and facilitated cell cycle transition. Further analysis showed that CARMA3 knockdown downregulated and its overexpression upregulated cyclin D1 expression and phospho-Rb levels. In addition, we found that CARMA3 depletion inhibited p-I{kappa}B levels and NF-{kappa}B activity and its overexpression increased p-I{kappa}B expression and NF-{kappa}B activity. NF-{kappa}B inhibitor BAY 11-7082 reversed the role of CARMA3 on cyclin D1 upregulation. In conclusion, our study found that CARMA3 is overexpressed in colon cancers and contributes to malignant cell growth by facilitating cell cycle progression through NF-{kappa}B mediated upregulation of cyclin D1.« less

Transcriptional responses of metallothionein gene to different stress factors in Pacific abalone (Haliotis discus hannai).

PubMed

Lee, Sang Yoon; Nam, Yoon Kwon

2016-11-01

A novel metallothionein (MT) gene from the Pacific abalone H. discus hannai was characterized and its mRNA expression patterns (tissue distribution, developmental expression and differential expression in responsive to various in vivo stimulatory treatments) were examined. Abalone MT shares conserved structural features with previously known gastropod orthologs at both genomic (i.e., tripartite organization) and amino acid (conserved Cys motifs) levels. The 5'-flanking regulatory region of abalone MT gene displayed various transcription factor binding motifs particularly including ones related with metal regulation and stress/immune responses. Tissue distribution and basal expression patterns of MT mRNAs indicated a potential association between ovarian MT expression and sexual maturation. Developmental expression pattern suggested the maternal contribution of MT mRNAs to embryonic and early larval developments. Abalone MT mRNAs could be significantly induced by various heavy metals in different tissues (gill, hepatopancreas, muscle and hemocyte) in a tissue- and/or metal-dependent fashion. In addition, the abalone MT gene was highly modulated in responsive to other non-metal, stimulatory treatments such as immune challenge (LPS, polyI:C and bacterial injections), hypoxia (decrease from normoxia 8 ppm-2 ppm), thermal elevation (increase from 20 °C to 30 °C), and xenobiotic exposure (250 ppb of 17α-ethynylestradiol and 0.25 ppb of 2,3,7,8-tetrachlorodibenzodioxin) where differential expression patterns were toward either up- or down-regulation depending on types of stimulations and tissues examined. Taken together, our results highlight that MT is a multifunctional effector playing in wide criteria of cellular pathways especially associated with development and stress responses in this abalone species. Copyright © 2016 Elsevier Ltd. All rights reserved.

Isolation of metallothionein from cells derived from aggressive form of high-grade prostate carcinoma using paramagnetic antibody-modified microbeads off-line coupled with electrochemical and electrophoretic analysis.

PubMed

Masarik, Michal; Gumulec, Jaromir; Sztalmachova, Marketa; Hlavna, Marian; Babula, Petr; Krizkova, Sona; Ryvolova, Marketa; Jurajda, Michal; Sochor, Jiri; Adam, Vojtech; Kizek, Rene

2011-12-01

Prostate cancer with altered zinc(II) cell metabolism is the second most frequently diagnosed cancer in developed countries. The alterations of zinc(II) metabolism can influence metabolism of other metal ions and can also be associated with the expression and translation of metal-binding proteins including metallothioneins. The aim of this article was to optimize immunoseparation protocol based on paramagnetic beads conjugated with protein G for the isolation of metallothionein. Isolated metallothionein was determined by differential pulse voltammetry Brdicka reaction and SDS-PAGE. Optimal conditions: antigen-binding time - 60 min, temperature - 70°C, and buffer composition and pH - acetate buffer, pH 4.3, were determined. Under the optimized conditions, lysates from 22Rv1 prostate cancer cells treated with various concentrations of cadmium(II) and copper(II) ions were analyzed. We observed strong correlation in all experimental groups and all lysate types (r>0.83 at p<0.041) between metallothionein concentration related to viability and concentration of copper(II) ions and cadmium(II) ions in medium. Moreover, the results were compared with standard sample preparation as heat treatment and SDS-PAGE analysis. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Regulation, overexpression, and target gene identification of Potato Homeobox 15 (POTH15) – a class-I KNOX gene in potato

PubMed Central

Mahajan, Ameya S.; Kondhare, Kirtikumar R.; Rajabhoj, Mohit P.; Kumar, Amit; Ghate, Tejashree; Ravindran, Nevedha; Habib, Farhat; Siddappa, Sundaresha; Banerjee, Anjan K.

2016-01-01

Potato Homeobox 15 (POTH15) is a KNOX-I (Knotted1-like homeobox) family gene in potato that is orthologous to Shoot Meristemless (STM) in Arabidopsis. Despite numerous reports on KNOX genes from different species, studies in potato are limited. Here, we describe photoperiodic regulation of POTH15, its overexpression phenotype, and identification of its potential targets in potato (Solanum tuberosum ssp. andigena). qRT-PCR analysis showed a higher abundance of POTH15 mRNA in shoot tips and stolons under tuber-inducing short-day conditions. POTH15 promoter activity was detected in apical and axillary meristems, stolon tips, tuber eyes, and meristems of tuber sprouts, indicating its role in meristem maintenance and leaf development. POTH15 overexpression altered multiple morphological traits including leaf and stem development, leaflet number, and number of nodes and branches. In particular, the rachis of the leaf was completely reduced and leaves appeared as a bouquet of leaflets. Comparative transcriptomic analysis of 35S::GUS and two POTH15 overexpression lines identified more than 6000 differentially expressed genes, including 2014 common genes between the two overexpression lines. Functional analysis of these genes revealed their involvement in responses to hormones, biotic/abiotic stresses, transcription regulation, and signal transduction. qRT-PCR of selected candidate target genes validated their differential expression in both overexpression lines. Out of 200 randomly chosen POTH15 targets, 173 were found to have at least one tandem TGAC core motif, characteristic of KNOX interaction, within 3.0kb in the upstream sequence of the transcription start site. Overall, this study provides insights to the role of POTH15 in controlling diverse developmental processes in potato. PMID:27217546

Hand1 overexpression inhibits medulloblastoma metastasis.

PubMed

Asuthkar, Swapna; Guda, Maheedhara R; Martin, Sarah E; Antony, Reuben; Fernandez, Karen; Lin, Julian; Tsung, Andrew J; Velpula, Kiran K

2016-08-19

Medulloblastoma (MB) is the most frequent malignant pediatric brain tumor. Current treatment includes surgery, radiation and chemotherapy. However, ongoing treatment in patients is further classified according to the presence or absence of metastasis. Since metastatic medulloblastoma are refractory to current treatments, there is need to identify novel biomarkers that could be used to reduce metastatic potential, and more importantly be targeted therapeutically. Previously, we showed that ionizing radiation-induced uPAR overexpression is associated with increased accumulation of β-catenin in the nucleus. We further demonstrated that uPAR protein act as cytoplasmic sequestration factor for a novel basic helix-loop-helix transcription factor, Hand1. Among the histological subtypes classical and desmoplastic subtypes account for the majority while large cell/anaplastic variant is most commonly associated with metastatic disease. In this present study using immunohistochemical approach and patient data mining for the first time, we demonstrated that Hand1 expression is observed to be downregulated in all the subtypes of medulloblastoma. Previously we showed that Hand1 overexpression regulated medulloblastoma angiogenesis and here we investigated the role of Hand1 in the context of Epithelial-Mesenchymal Transition (EMT). Moreover, UW228 and D283 cells overexpressing Hand1 demonstrated decreased-expression of mesenchymal markers (N-cadherin, β-catenin and SOX2); metastatic marker (SMA); and increased expression of epithelial marker (E-cadherin). Strikingly, human pluripotent stem cell antibody array showed that Hand1 overexpression resulted in substantial decrease in pluripotency markers (Nanog, Oct3/4, Otx2, Flk1) suggesting that Hand1 expression may be essential to attenuate the EMT and our findings underscore a novel role for Hand1 in medulloblastoma metastasis. Copyright © 2016 Elsevier Inc. All rights reserved.

Isolation and characterization of metallothioneins in calves ingesting Zn toxic diets

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

Graham, T.W.; Clegg, M.S.; Lonnerdal, B.

1986-03-05

The authors have recently described an outbreak of Zn toxicosis in 95 Holstein bull calves which occurred as a result of an accidental over-supplementation of the diet with Zn. Signs of Zn toxicosis including anorexia, polydipsia, polyphagia, polyurea and diarrhea, began to appear 23 days after initiation of the diet. Liver, kidney, muscle and brain were collected from animals that died or were euthanized. Multielement analysis indicated that liver had the highest concentration of Zn (362 ..mu..g Zn/g wet wt.) followed by kidney (233 ..mu..g Zn/g wet wt.), muscle (22 ..mu..g Zn/g wet wt.) and brain (10 ..mu..g Zn/g wetmore » wt.). To examine the toxic effects of Zn at the molecular level, liver was fractionated by conventional molecular sieve (Sephadex G75) and anion exchange chromatography (DEAE Sephadex A-25). In addition, Fast Protein Liquid Chromatography (FPLC) was used to verify the results obtained by conventional methods. The principle advantages of FPLC are that the molecular sieve (Superose 12) and anion (Mono Q) steps are performed in 1 h as opposed to several hours, thus substantially minimizing artifacts resulting from oxidative degradation of labile proteins. Zn was primarily associated with two peaks, designated metallothionein (MT) I and MT II, in a ratio of 10 to 1. The results show that one effect of Zn toxicity in calves can be a preferential induction of MT I.« less

Decreased Cocaine Motor Sensitization and Self-Administration in Mice Overexpressing Cannabinoid CB2 Receptors

PubMed Central

Aracil-Fernández, Auxiliadora; Trigo, José M; García-Gutiérrez, María S; Ortega-Álvaro, Antonio; Ternianov, Alexander; Navarro, Daniela; Robledo, Patricia; Berbel, Pere; Maldonado, Rafael; Manzanares, Jorge

2012-01-01

The potential involvement of the cannabinoid CB2 receptors (CB2r) in the adaptive responses induced by cocaine was studied in transgenic mice overexpressing the CB2r (CB2xP) and in wild-type (WT) littermates. For this purpose, the acute and sensitized locomotor responses to cocaine, conditioned place preference, and cocaine intravenous self-administration were evaluated. In addition, we assessed whether CB2r were localized in neurons and/or astrocytes, and whether they colocalized with dopamine D1 and D2 receptors (D1Dr and D2Dr). Dopamine (DA) extracellular levels in the nucleus accumbens (NAcc), and gene expression of tyrosine hydroxylase (TH) and DA transporter (DAT) in the ventral tegmental area (VTA), and μ-opioid and cannabinoid CB1 receptors in the NAcc were also studied in both genotypes. CB2xP mice showed decreased motor response to acute administration of cocaine (10–20 mg/kg) and cocaine-induced motor sensitization compared with WT mice. CB2xP mice presented cocaine-induced conditioned place aversion and self-administered less cocaine than WT mice. CB2r were found in neurons and astrocytes and colocalized with D2Dr in the VTA and NAcc. No significant differences in extracellular DA levels in the NAcc were observed between genotypes after cocaine administration. Under baseline conditions, TH and DAT gene expression was higher and μ-opioid receptor gene expression was lower in CB2xP than in WT mice. However, both genotypes showed similar changes in TH and μ-opioid receptor gene expression after cocaine challenge independently of the pretreatment received. Importantly, the cocaine challenge decreased DAT gene expression to a lesser extent in cocaine-pretreated CB2xP than in cocaine-pretreated WT mice. These results revealed that CB2r are involved in cocaine motor responses and cocaine self-administration, suggesting that this receptor could represent a promising target to develop novel treatments for cocaine addiction. PMID:22414816

Anchoring plant metallothioneins to the inner face of the plasma membrane of Saccharomyces cerevisiae cells leads to heavy metal accumulation.

PubMed

Ruta, Lavinia Liliana; Lin, Ya-Fen; Kissen, Ralph; Nicolau, Ioana; Neagoe, Aurora Daniela; Ghenea, Simona; Bones, Atle M; Farcasanu, Ileana Cornelia

2017-01-01

In this study we engineered yeast cells armed for heavy metal accumulation by targeting plant metallothioneins to the inner face of the yeast plasma membrane. Metallothioneins (MTs) are cysteine-rich proteins involved in the buffering of excess metal ions, especially Cu(I), Zn(II) or Cd(II). The cDNAs of seven Arabidopsis thaliana MTs (AtMT1a, AtMT1c, AtMT2a, AtMT2b, AtMT3, AtMT4a and AtMT4b) and four Noccaea caerulescens MTs (NcMT1, NcMT2a, NcMT2b and NcMT3) were each translationally fused to the C-terminus of a myristoylation green fluorescent protein variant (myrGFP) and expressed in Saccharomyces cerevisiae cells. The myrGFP cassette introduced a yeast myristoylation sequence which allowed directional targeting to the cytosolic face of the plasma membrane along with direct monitoring of the intracellular localization of the recombinant protein by fluorescence microscopy. The yeast strains expressing plant MTs were investigated against an array of heavy metals in order to identify strains which exhibit the (hyper)accumulation phenotype without developing toxicity symptoms. Among the transgenic strains which could accumulate Cu(II), Zn(II) or Cd(II), but also non-canonical metal ions, such as Co(II), Mn(II) or Ni(II), myrGFP-NcMT3 qualified as the best candidate for bioremediation applications, thanks to the robust growth accompanied by significant accumulative capacity.

Overexpression of BAX INHIBITOR-1 Links Plasma Membrane Microdomain Proteins to Stress.

PubMed

Ishikawa, Toshiki; Aki, Toshihiko; Yanagisawa, Shuichi; Uchimiya, Hirofumi; Kawai-Yamada, Maki

2015-10-01

BAX INHIBITOR-1 (BI-1) is a cell death suppressor widely conserved in plants and animals. Overexpression of BI-1 enhances tolerance to stress-induced cell death in plant cells, although the molecular mechanism behind this enhancement is unclear. We recently found that Arabidopsis (Arabidopsis thaliana) BI-1 is involved in the metabolism of sphingolipids, such as the synthesis of 2-hydroxy fatty acids, suggesting the involvement of sphingolipids in the cell death regulatory mechanism downstream of BI-1. Here, we show that BI-1 affects cell death-associated components localized in sphingolipid-enriched microdomains of the plasma membrane in rice (Oryza sativa) cells. The amount of 2-hydroxy fatty acid-containing glucosylceramide increased in the detergent-resistant membrane (DRM; a biochemical counterpart of plasma membrane microdomains) fraction obtained from BI-1-overexpressing rice cells. Comparative proteomics analysis showed quantitative changes of DRM proteins in BI-1-overexpressing cells. In particular, the protein abundance of FLOTILLIN HOMOLOG (FLOT) and HYPERSENSITIVE-INDUCED REACTION PROTEIN3 (HIR3) markedly decreased in DRM of BI-1-overexpressing cells. Loss-of-function analysis demonstrated that FLOT and HIR3 are required for cell death by oxidative stress and salicylic acid, suggesting that the decreased levels of these proteins directly contribute to the stress-tolerant phenotypes in BI-1-overexpressing rice cells. These findings provide a novel biological implication of plant membrane microdomains in stress-induced cell death, which is negatively modulated by BI-1 overexpression via decreasing the abundance of a set of key proteins involved in cell death. © 2015 American Society of Plant Biologists. All Rights Reserved.

Hyaluronic Acid is Overexpressed in Fibrotic Lung Tissue and Promotes Collagen Expression

DTIC Science & Technology

2009-04-01

inflammation, and fibrosis (i.e. the overexpression of collagen). Lung fibrosis is the major cause of morbidity and mortality in scleroderma and is...References……………………………………………………………………………. 8 Appendices…………………………………………………………………………… 9 INTRODUCTION Systemic scleroderma is a... scleroderma . The overexpression of collagen I in fibrotic lung tissue is accompanied by the overexpression of other ECM molecules (e.g. the proteins

Association of metallothionein-III with oligodendroglial cytoplasmic inclusions in multiple system atrophy.

PubMed

Pountney, D L; Dickson, T C; Power, J H T; Vickers, J C; West, A J; Gai, W P

2011-01-01

Multiple system atrophy (MSA) is an adult-onset neurodegenerative disease characterised by Parkinsonian and autonomic symptoms and by widespread intracytoplasmic inclusion bodies in oligodendrocytes. These glial cytoplasmic inclusions (GCIs) are comprised of 9-10 nm filaments rich in the protein alpha-synuclein, also found in neuronal inclusion bodies associated with Parkinson's disease. Metallothioneins (MTs) are a class of low-molecular weight (6-7 kDa), cysteine-rich metal-binding proteins the expression of which is induced by heavy metals, glucocorticoids, cytokines and oxidative stress. Recent studies have shown a role for the ubiquitously expressed MT-I/II isoforms in the brain following a variety of stresses, whereas, the function of the brain-specific MT isoform, MT-III, is less clear. MT-III and MT-I/II immunostaining of post-mortem tissue in MSA and normal control human brains showed that the number of MT-III-positive cells is significantly increased in MSA in visual cortex, whereas MT-I/II isoforms showed no significant difference in the distribution of immunopositive cells in MSA compared to normal tissue. GCIs were immunopositive for MT-III, but were immunonegative for the MT-I/II isoforms. Immunofluorescence double labelling showed the co-localisation of alpha-synuclein and MT-III in GCIs in MSA tissue. In isolated GCIs, transmission electron microscopy demonstrated MT-III immunogold labelling of the amorphous material surrounding alpha-synuclein filaments in GCIs. High-molecular weight MT-III species in addition to MT-III monomer were detected in GCIs by Western analysis of the detergent-solubilised proteins of purified GCIs. These results show that MT-III, but not MT-I/II, is a specific component of GCIs, present in abnormal aggregated forms external to the alpha-synuclein filaments.

Effect of metallothionein core promoter region polymorphism on cadmium, zinc and copper levels in autopsy kidney tissues from a Turkish population

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

Kayaalti, Zeliha, E-mail: kayaalti@medicine.ankara.edu.t; Mergen, Goerkem; Soeylemezoglu, Tuelin

2010-06-01

Metallothioneins (MTs) are metal-binding, low molecular weight proteins and are involved in pathophysiological processes like metabolism of essential metals, metal ion homeostasis and detoxification of heavy metals. Metallothionein expression is induced by various heavy metals especially cadmium, mercury and zinc; MTs suppress toxicity of heavy metals by binding themselves to these metals. The aim of this study was to investigate the association between the - 5 A/G metallothionein 2A (MT2A) single nucleotide polymorphism (SNP) and Cd, Zn and Cu levels in the renal cortex from autopsy cases. MT2A core promoter region - 5 A/G SNP was analyzed by PCR-RFLP methodmore » using 114 autopsy kidney tissues and the genotype frequencies of this polymorphism were found as 87.7% homozygote typical (AA), 11.4% heterozygote (AG) and 0.9% homozygote atypical (GG). In order to assess the Cd, Zn and Cu levels in the same autopsy kidney tissues, a dual atomic absorption spectrophotometer system was used and the average levels of Cd, Zn and Cu were measured as 95.54 {+-} 65.58 {mu}g/g, 181.20 {+-} 87.72 {mu}g/g and 17.14 {+-} 16.28 {mu}g/g, respectively. As a result, no statistical association was found between the - 5 A/G SNP in the MT2A gene and the Zn and Cu levels in the renal cortex (p > 0.05), but considerably high accumulation of Cd was monitored for individuals having AG (151.24 {+-} 60.21 {mu}g/g) and GG genotypes (153.09 {mu}g/g) compared with individuals having AA genotype (87.72 {+-} 62.98 {mu}g/g) (p < 0.05). These results show that the core promoter region polymorphism of metallothionein 2A increases the accumulation of Cd in human renal cortex.« less

5 CFR 894.510 - When may I decrease my type of enrollment?

Code of Federal Regulations, 2013 CFR

2013-01-01

... 5 Administrative Personnel 2 2013-01-01 2013-01-01 false When may I decrease my type of enrollment? 894.510 Section 894.510 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL... Changing Enrollment § 894.510 When may I decrease my type of enrollment? (a) You may decrease your type of...

In vivo-folded metal-metallothionein 3 complexes reveal the Cu-thionein rather than Zn-thionein character of this brain-specific mammalian metallothionein.

PubMed

Artells, Ester; Palacios, Oscar; Capdevila, Mercè; Atrian, Sílvia

2014-03-01

Metallothionein-3 (MT3) is one of the four mammalian metallothioneins (MT), and is constitutively synthesized in the brain. MT3 acts both intracellularly and extracellularly in this organ, performing functions related to neuronal growth and physiological metal (Zn and Cu) handling. It appears to be involved in the prevention of neurodegenerative disorders caused by insoluble Cu-peptide aggregates, as it triggers a Zn-Cu swap that may counteract the deleterious presence of copper in neural tissues. The literature data on MT3 coordination come from studies either on apo-MT3 reconstitution or the reaction of Zn-MT3 with Cu(2+) , an ion that is hardly present inside cells. To ascertain the MT3 metal-binding features in a scenario closer to the reductive cell cytoplasm, a study of the recombinant Zn(2+) , Cd(2+) and Cu(+) complexes of MT3, βMT3, and αMT3, as well as the in vitro Zn(2+) -Cd(2+) and Zn(2+) -Cu(+) replacement processes, is presented here. We conclude that MT3 has a Cu-thionein character that is stronger than that of the MT1 and MT2 isoforms - also present in the mammalian brain - which is mainly contributed by its β domain. In contrast, the α domain retains a high capacity to bind Zn(2+) ions, and, consequently, the entire MT3 peptide shows a peculiar dual ability to handle both metal ions. The nature of the formed Cu(+) -MT3 complexes oscillates from heterometallic Cu6 Zn4 -MT3 to homometallic Cu10 -MT3 major species, in a narrow Cu concentration range. Therefore, the entire MT3 peptide shows a high capacity to bind Cu(+) , provided that this occurs in a nonoxidative milieux. This reflects a peculiar property of this MT isoform, which accurately senses different Cu contents in the environment in which it is synthesized. © 2014 FEBS.

A copper-induced metallothionein gene from Exopalaemon carinicauda and its response to heavy metal ions.

PubMed

Zhang, Jiquan; Wang, Jing; Gui, Tianshu; Sun, Zheng; Xiang, Jianhai

2014-09-01

A full-length copper-induced metallothionein (EcMT-Cu) cDNA was obtained from Exopalaemon carinicauda (Holthuis) and it contained a 198 bp open reading frame that encoded a peptide with 65 amino acid residues. Twenty-one cysteines were found in deduced amino acid sequence and the cysteine (Cys)-rich characteristic was also reported in different types of metallothioneins from other species. EcMT-Cu mRNA expression profile showed that it is the hepatopancreas specific gene. The expression of EcMT-Cu was extremely different when shrimp were exposed to seawater containing 50 μM CuSO4 or 2.5 μM CdCl2. The expression of EcMT-Cu in shrimp was significantly up-regulated at 12 and 24 h after exposure to CuSO4, however, its expression was not induced compared to that of pretreatment (p>0.05) when shrimp were exposed to CdCl2. The transcript of EcMT-Cu was found to be extremely low at gastrula and nauplius stage and expression of EcMT-Cu could be detected from egg protozoa stage. Copyright © 2014 Elsevier B.V. All rights reserved.

Targeted Overexpression of Inducible 6-Phosphofructo-2-kinase in Adipose Tissue Increases Fat Deposition but Protects against Diet-induced Insulin Resistance and Inflammatory Responses*

PubMed Central

Huo, Yuqing; Guo, Xin; Li, Honggui; Xu, Hang; Halim, Vera; Zhang, Weiyu; Wang, Huan; Fan, Yang-Yi; Ong, Kuok Teong; Woo, Shih-Lung; Chapkin, Robert S.; Mashek, Douglas G.; Chen, Yanming; Dong, Hui; Lu, Fuer; Wei, Lai; Wu, Chaodong

2012-01-01

Increasing evidence demonstrates the dissociation of fat deposition, the inflammatory response, and insulin resistance in the development of obesity-related metabolic diseases. As a regulatory enzyme of glycolysis, inducible 6-phosphofructo-2-kinase (iPFK2, encoded by PFKFB3) protects against diet-induced adipose tissue inflammatory response and systemic insulin resistance independently of adiposity. Using aP2-PFKFB3 transgenic (Tg) mice, we explored the ability of targeted adipocyte PFKFB3/iPFK2 overexpression to modulate diet-induced inflammatory responses and insulin resistance arising from fat deposition in both adipose and liver tissues. Compared with wild-type littermates (controls) on a high fat diet (HFD), Tg mice exhibited increased adiposity, decreased adipose inflammatory response, and improved insulin sensitivity. In a parallel pattern, HFD-fed Tg mice showed increased hepatic steatosis, decreased liver inflammatory response, and improved liver insulin sensitivity compared with controls. In both adipose and liver tissues, increased fat deposition was associated with lipid profile alterations characterized by an increase in palmitoleate. Additionally, plasma lipid profiles also displayed an increase in palmitoleate in HFD-Tg mice compared with controls. In cultured 3T3-L1 adipocytes, overexpression of PFKFB3/iPFK2 recapitulated metabolic and inflammatory changes observed in adipose tissue of Tg mice. Upon treatment with conditioned medium from iPFK2-overexpressing adipocytes, mouse primary hepatocytes displayed metabolic and inflammatory responses that were similar to those observed in livers of Tg mice. Together, these data demonstrate a unique role for PFKFB3/iPFK2 in adipocytes with regard to diet-induced inflammatory responses in both adipose and liver tissues. PMID:22556414

Metallothionein expression in chloroplasts enhances mercury accumulation and phytoremediation capability.

PubMed

Ruiz, Oscar N; Alvarez, Derry; Torres, Cesar; Roman, Laura; Daniell, Henry

2011-06-01

Genetic engineering to enhance mercury phytoremediation has been accomplished by expression of the merAB genes that protects the cell by converting Hg[II] into Hg[0] which volatilizes from the cell. A drawback of this approach is that toxic Hg is released back into the environment. A better phytoremediation strategy would be to accumulate mercury inside plants for subsequent retrieval. We report here the development of a transplastomic approach to express the mouse metallothionein gene (mt1) and accumulate mercury in high concentrations within plant cells. Real-time PCR analysis showed that up to 1284 copies of the mt1 gene were found per cell when compared with 1326 copies of the 16S rrn gene, thereby attaining homoplasmy. Past studies in chloroplast transformation used qualitative Southern blots to evaluate indirectly transgene copy number, whereas we used real-time PCR for the first time to establish homoplasmy and estimate transgene copy number and transcript levels. The mt1 transcript levels were very high with 183,000 copies per ng of RNA or 41% the abundance of the 16S rrn transcripts. The transplastomic lines were resistant up to 20 μm mercury and maintained high chlorophyll content and biomass. Although the transgenic plants accumulated high concentrations of mercury in all tissues, leaves accumulated up to 106 ng, indicating active phytoremediation and translocation of mercury. Such accumulation of mercury in plant tissues facilitates proper disposal or recycling. This study reports, for the first time, the use of metallothioneins in plants for mercury phytoremediation. Chloroplast genetic engineering approach is useful to express metal-scavenging proteins for phytoremediation. © 2011 The Authors. Plant Biotechnology Journal © 2011 Society for Experimental Biology, Association of Applied Biologists and Blackwell Publishing Ltd.

Pirfenidone inhibits TGF-β1-induced over-expression of collagen type I and heat shock protein 47 in A549 cells

PubMed Central

2012-01-01

Background Pirfenidone is a novel anti-fibrotic and anti-inflammatory agent that inhibits the progression of fibrosis in animal models and in patients with idiopathic pulmonary fibrosis (IPF). We previously showed that pirfenidone inhibits the over-expression of collagen type I and of heat shock protein (HSP) 47, a collagen-specific molecular chaperone, in human lung fibroblasts stimulated with transforming growth factor (TGF)-β1 in vitro. The increased numbers of HSP47-positive type II pneumocytes as well as fibroblasts were also diminished by pirfenidone in an animal model of pulmonary fibrosis induced by bleomycin. The present study evaluates the effects of pirfenidone on collagen type I and HSP47 expression in the human alveolar epithelial cell line, A549 cells in vitro. Methods The expression of collagen type I, HSP47 and E-cadherin mRNAs in A549 cells stimulated with TGF-β1 was evaluated by Northern blotting or real-time PCR. The expression of collagen type I, HSP47 and fibronectin proteins was assessed by immunocytochemical staining. Results TGF-β1 stimulated collagen type I and HSP47 mRNA and protein expression in A549 cells, and pirfenidone significantly inhibited this process. Pirfenidone also inhibited over-expression of the fibroblast phenotypic marker fibronectin in A549 cells induced by TGF-β1. Conclusion We concluded that the anti-fibrotic effects of pirfenidone might be mediated not only through the direct inhibition of collagen type I expression but also through the inhibition of HSP47 expression in alveolar epithelial cells, which results in reduced collagen synthesis in lung fibrosis. Furthermore, pirfenidone might partially inhibit the epithelial-mesenchymal transition. PMID:22694981

Biglycan Overexpression on Tooth Enamel Formation in Transgenic Mice

PubMed Central

Wen, Xin; Zou, YanMing; Luo, Wen; Goldberg, Michel; Moats, Rex; Conti, Peter S.; Snead, Malcolm L.; Paine, Michael L.

2008-01-01

Previously it was shown that the volume of forming enamel of molar teeth in biglycan-null mice was greater than in genetically matched wild-type mice. This phenotypic change appeared to result from an increase in amelogenin expression, implying that biglycan directly influences amelogenin synthesis. To determine whether biglycan over-expression resulted in decreased amelogenin expression, we engineered transgenic mice to over-express biglycan in the enamel organ epithelium. Biglycan over-expression did not significantly affect the amelogenin expression in incisor and molar teeth in 3-day transgenic mice. In the transgenic animals we observed that the immature and mature enamel appeared normal. These results suggested that increasing the biglycan expression, in the cells that synthesize the precursor protein matrix for enamel, has a negligible influence on amelogenesis. PMID:18727043

SIRT1 overexpression ameliorates a mouse model of SOD1-linked amyotrophic lateral sclerosis via HSF1/HSP70i chaperone system.

PubMed

Watanabe, Seiji; Ageta-Ishihara, Natsumi; Nagatsu, Shinji; Takao, Keizo; Komine, Okiru; Endo, Fumito; Miyakawa, Tsuyoshi; Misawa, Hidemi; Takahashi, Ryosuke; Kinoshita, Makoto; Yamanaka, Koji

2014-08-29

Dominant mutations in superoxide dismutase 1 (SOD1) cause degeneration of motor neurons in a subset of inherited amyotrophic lateral sclerosis (ALS). The pathogenetic process mediated by misfolded and/or aggregated mutant SOD1 polypeptides is hypothesized to be suppressed by protein refolding. This genetic study is aimed to test whether mutant SOD1-mediated ALS pathology recapitulated in mice could be alleviated by overexpressing a longevity-related deacetylase SIRT1 whose substrates include a transcription factor heat shock factor 1 (HSF1), the master regulator of the chaperone system. We established a line of transgenic mice that chronically overexpress SIRT1 in the brain and spinal cord. While inducible HSP70 (HSP70i) was upregulated in the spinal cord of SIRT1 transgenic mice (PrP-Sirt1), no neurological and behavioral alterations were detected. To test hypothetical benefits of SIRT1 overexpression, we crossbred PrP-Sirt1 mice with two lines of ALS model mice: A high expression line that exhibits a severe phenotype (SOD1G93A-H) or a low expression line with a milder phenotype (SOD1G93A-L). The Sirt1 transgene conferred longer lifespan without altering the time of symptomatic onset in SOD1G93A-L. Biochemical analysis of the spinal cord revealed that SIRT1 induced HSP70i expression through deacetylation of HSF1 and that SOD1G93A-L/PrP-Sirt1 double transgenic mice contained less insoluble SOD1 than SOD1G93A-L mice. Parallel experiments showed that Sirt1 transgene could not rescue a more severe phenotype of SOD1G93A-H transgenic mice partly because their HSP70i level had peaked out. The genetic supplementation of SIRT1 can ameliorate a mutant SOD1-linked ALS mouse model partly through the activation of the HSF1/HSP70i chaperone system. Future studies shall include testing potential benefits of pharmacological enhancement of the deacetylation activity of SIRT1 after the onset of the symptom.

Studies of insulin secretory responses and of arachidonic acid incorporation into phospholipids of stably transfected insulinoma cells that overexpress group VIA phospholipase A2 (iPLA2beta ) indicate a signaling rather than a housekeeping role for iPLA2beta.

PubMed

Ma, Z; Ramanadham, S; Wohltmann, M; Bohrer, A; Hsu, F F; Turk, J

2001-04-20

A cytosolic 84-kDa group VIA phospholipase A(2) (iPLA(2)beta) that does not require Ca(2+) for catalysis has been cloned from several sources, including rat and human pancreatic islet beta-cells and murine P388D1 cells. Many potential iPLA(2)beta functions have been proposed, including a signaling role in beta-cell insulin secretion and a role in generating lysophosphatidylcholine acceptors for arachidonic acid incorporation into P388D1 cell phosphatidylcholine (PC). Proposals for iPLA(2)beta function rest in part on effects of inhibiting iPLA(2)beta activity with a bromoenol lactone (BEL) suicide substrate, but BEL also inhibits phosphatidate phosphohydrolase-1 and a group VIB phospholipase A(2). Manipulation of iPLA(2)beta expression by molecular biologic means is an alternative approach to study iPLA(2)beta functions, and we have used a retroviral construct containing iPLA(2)beta cDNA to prepare two INS-1 insulinoma cell clonal lines that stably overexpress iPLA(2)beta. Compared with parental INS-1 cells or cells transfected with empty vector, both iPLA(2)beta-overexpressing lines exhibit amplified insulin secretory responses to glucose and cAMP-elevating agents, and BEL substantially attenuates stimulated secretion. Electrospray ionization mass spectrometric analyses of arachidonic acid incorporation into INS-1 cell PC indicate that neither overexpression nor inhibition of iPLA(2)beta affects the rate or extent of this process in INS-1 cells. Immunocytofluorescence studies with antibodies directed against iPLA(2)beta indicate that cAMP-elevating agents increase perinuclear fluorescence in INS-1 cells, suggesting that iPLA(2)beta associates with nuclei. These studies are more consistent with a signaling than with a housekeeping role for iPLA(2)beta in insulin-secreting beta-cells.

Overexpression of a wheat (Triticum aestivum L.) bZIP transcription factor gene, TabZIP6, decreased the freezing tolerance of transgenic Arabidopsis seedlings by down-regulating the expression of CBFs.

PubMed

Cai, Wangting; Yang, Yaling; Wang, Weiwei; Guo, Guangyan; Liu, Wei; Bi, Caili

2018-03-01

The basic leucine zipper (bZIP) proteins play important roles against abiotic stress in plants, including cold stress. However, most bZIPs involved in plant freezing tolerance are positive regulators. Only a few bZIPs function negatively in cold stress response. In this study, TabZIP6, a Group C bZIP transcription factor gene from common wheat (Triticum aestivum L.), was cloned and characterized. The transcript of TabZIP6 was strongly induced by cold treatment (4 °C). TabZIP6 is a nuclear-localized protein with transcriptional activation activity. Arabidopsis plants overexpressing TabZIP6 showed decreased tolerance to freezing stress. Microarray as well as quantitative real-time PCR (qRT-PCR) analysis showed that CBFs and some key COR genes, including COR47 and COR15B, were down-regulated by cold treatment in TabZIP6-overexpressing Arabidopsis lines. TabZIP6 was capable of binding to the G-box motif and the CBF1 and CBF3 promoters in yeast cells. A yeast two-hybrid assay revealed that TabZIP6, as well as the other two Group S bZIP proteins involved in cold stress tolerance in wheat, Wlip19 and TaOBF1, can form homodimers by themselves and heterodimers with each other. These results suggest that TabZIP6 may function negatively in the cold stress response by binding to the promoters of CBFs, and thereby decreasing the expression of downstream COR genes in TabZIP6-overexpressing Arabidopsis seedlings. Copyright © 2018. Published by Elsevier Masson SAS.

Bioimaging of metallothioneins in ocular tissue sections by laser ablation-ICP-MS using bioconjugated gold nanoclusters as specific tags.

PubMed

Cruz-Alonso, María; Fernandez, Beatriz; Álvarez, Lydia; González-Iglesias, Héctor; Traub, Heike; Jakubowski, Norbert; Pereiro, Rosario

2017-12-18

An immunohistochemical method is described to visualize the distribution of metallothioneins 1/2 (MT 1/2) and metallothionein 3 (MT 3) in human ocular tissue. It is making use of (a) antibodies conjugated to gold nanoclusters (AuNCs) acting as labels, and (b) laser ablation (LA) coupled to inductively coupled plasma - mass spectrometry (ICP-MS). Water-soluble fluorescent AuNCs (with an average size of 2.7 nm) were synthesized and then conjugated to antibody by carbodiimide coupling. The surface of the modified AuNCs was then blocked with hydroxylamine to avoid nonspecific interactions with biological tissue. Immunoassays for MT 1/2 and MT 3 in ocular tissue sections (5 μm thick) from two post mortem human donors were performed. Imaging studies were then performed by fluorescence using confocal microscopy, and LA-ICP-MS was performed in the retina to measure the signal for gold. Signal amplification by the >500 gold atoms in each nanocluster allowed the antigens (MT 1/2 and MT 3) to be imaged by LA-ICP-MS using a laser spot size as small as 4 μm. The image patterns found in retina are in good agreement with those obtained by conventional fluorescence immunohistochemistry which was used as an established reference method. Graphical abstract Gold nanoclusters (AuNCs) conjugated to a primary specific antibody serve as a label for amplified bioimaging of metallothioneins (MTs) by laser ablation coupled to inductively coupled plasma - mass spectrometry (ICP-MS) in human ocular tissue sections.

Overexpression of Catalase Diminishes Oxidative Cysteine Modifications of Cardiac Proteins

PubMed Central

Yao, Chunxiang; Behring, Jessica B.; Shao, Di; Sverdlov, Aaron L.; Whelan, Stephen A.; Elezaby, Aly; Yin, Xiaoyan; Siwik, Deborah A.; Seta, Francesca; Costello, Catherine E.; Cohen, Richard A.; Matsui, Reiko; Colucci, Wilson S.; McComb, Mark E.; Bachschmid, Markus M.

2015-01-01

Reactive protein cysteine thiolates are instrumental in redox regulation. Oxidants, such as hydrogen peroxide (H2O2), react with thiolates to form oxidative post-translational modifications, enabling physiological redox signaling. Cardiac disease and aging are associated with oxidative stress which can impair redox signaling by altering essential cysteine thiolates. We previously found that cardiac-specific overexpression of catalase (Cat), an enzyme that detoxifies excess H2O2, protected from oxidative stress and delayed cardiac aging in mice. Using redox proteomics and systems biology, we sought to identify the cysteines that could play a key role in cardiac disease and aging. With a ‘Tandem Mass Tag’ (TMT) labeling strategy and mass spectrometry, we investigated differential reversible cysteine oxidation in the cardiac proteome of wild type and Cat transgenic (Tg) mice. Reversible cysteine oxidation was measured as thiol occupancy, the ratio of total available versus reversibly oxidized cysteine thiols. Catalase overexpression globally decreased thiol occupancy by ≥1.3 fold in 82 proteins, including numerous mitochondrial and contractile proteins. Systems biology analysis assigned the majority of proteins with differentially modified thiols in Cat Tg mice to pathways of aging and cardiac disease, including cellular stress response, proteostasis, and apoptosis. In addition, Cat Tg mice exhibited diminished protein glutathione adducts and decreased H2O2 production from mitochondrial complex I and II, suggesting improved function of cardiac mitochondria. In conclusion, our data suggest that catalase may alleviate cardiac disease and aging by moderating global protein cysteine thiol oxidation. PMID:26642319

Improvement of n-butanol tolerance in Escherichia coli by membrane-targeted tilapia metallothionein

PubMed Central

2013-01-01

Background Though n-butanol has been proposed as a potential transportation biofuel, its toxicity often causes oxidative stress in the host microorganism and is considered one of the bottlenecks preventing its efficient mass production. Results To relieve the oxidative stress in the host cell, metallothioneins (MTs), which are known as scavengers for reactive oxygen species (ROS), were engineered in E. coli hosts for both cytosolic and outer-membrane-targeted (osmoregulatory membrane protein OmpC fused) expression. Metallothioneins from human (HMT), mouse (MMT), and tilapia fish (TMT) were tested. The host strain expressing membrane-targeted TMT showed the greatest ability to reduce oxidative stresses induced by n-butanol, ethanol, furfural, hydroxymethylfurfural, and nickel. The same strain also allowed for an increased growth rate of recombinant E. coli under n-butanol stress. Further experiments indicated that the TMT-fused OmpC protein could not only function in ROS scavenging but also regulate either glycine betaine (GB) or glucose uptake via osmosis, and the dual functional fusion protein could contribute in an enhancement of the host microorganism’s growth rate. Conclusions The abilities of scavenging intracellular or extracellular ROS by these engineering E. coli were examined, and TMT show the best ability among three MTs. Additionally, the membrane-targeted fusion protein, OmpC-TMT, improved host tolerance up to 1.5% n-butanol above that of TMT which is only 1%. These results presented indicate potential novel approaches for engineering stress tolerant microorganism strains. PMID:24020941

Improvement of n-butanol tolerance in Escherichia coli by membrane-targeted tilapia metallothionein.

PubMed

Chin, Wei-Chih; Lin, Kuo-Hsing; Chang, Jui-Jen; Huang, Chieh-Chen

2013-09-11

Though n-butanol has been proposed as a potential transportation biofuel, its toxicity often causes oxidative stress in the host microorganism and is considered one of the bottlenecks preventing its efficient mass production. To relieve the oxidative stress in the host cell, metallothioneins (MTs), which are known as scavengers for reactive oxygen species (ROS), were engineered in E. coli hosts for both cytosolic and outer-membrane-targeted (osmoregulatory membrane protein OmpC fused) expression. Metallothioneins from human (HMT), mouse (MMT), and tilapia fish (TMT) were tested. The host strain expressing membrane-targeted TMT showed the greatest ability to reduce oxidative stresses induced by n-butanol, ethanol, furfural, hydroxymethylfurfural, and nickel. The same strain also allowed for an increased growth rate of recombinant E. coli under n-butanol stress. Further experiments indicated that the TMT-fused OmpC protein could not only function in ROS scavenging but also regulate either glycine betaine (GB) or glucose uptake via osmosis, and the dual functional fusion protein could contribute in an enhancement of the host microorganism's growth rate. The abilities of scavenging intracellular or extracellular ROS by these engineering E. coli were examined, and TMT show the best ability among three MTs. Additionally, the membrane-targeted fusion protein, OmpC-TMT, improved host tolerance up to 1.5% n-butanol above that of TMT which is only 1%. These results presented indicate potential novel approaches for engineering stress tolerant microorganism strains.

Metal ion release from metallothioneins: proteolysis as an alternative to oxidation.

PubMed

Peroza, Estevão A; dos Santos Cabral, Augusto; Wan, Xiaoqiong; Freisinger, Eva

2013-09-01

Metallothioneins (MTs) are among others involved in the cellular regulation of essential Zn(II) and Cu(I) ions. However, the high binding affinity of these proteins requires additional factors to promote metal ion release under physiological conditions. The mechanisms and efficiencies of these processes leave many open questions. We report here a comprehensive analysis of the Zn(II)-release properties of various MTs with special focus on members of the four main subfamilies of plant MTs. Zn(II) competition experiments with the metal ion chelator 4-(2-pyridylazo)resorcinol (PAR) in the presence of the cellular redox pair glutathione (GSH)/glutathione disulfide (GSSG) show that plant MTs from the subfamilies MT1, MT2, and MT3 are remarkably more affected by oxidative stress than those from the Ec subfamily and the well-characterized human MT2 form. In addition, we evaluated proteolytic digestion with trypsin and proteinase K as an alternative mechanism for selective promotion of metal ion release from MTs. Also here the observed percentage of liberated metal ions depends strongly on the MT form evaluated. Closer evaluation of the data additionally allowed deducing the thermodynamic and kinetic properties of the Zn(II) release processes. The Cu(I)-form of chickpea MT2 was used to exemplify that both oxidation and proteolysis are also effective ways to increase the transfer of copper ions to other molecules. Zn(II) release experiments with the individual metal-binding domains of Ec-1 from wheat grain reveal distinct differences from the full-length protein. This triggers the question about the roles of the long cysteine-free peptide stretches typical for plant MTs.

Kinetic model of cadmium accumulation and elimination and metallothionein response in Ruditapes decussatus.

PubMed

Serafim, Angela; Bebianno, Maria João

2007-05-01

The aim of the present study was to determine the response of metallothionein (MT) during Cd accumulation and elimination in different tissues of the estuarine bivalve Ruditapes decussatus exposed to two nominal Cd concentrations (4 and 40 microg/L) for 40 d, followed by a depuration period of 50 d. Cadmium was accumulated in all tissues of R. decussatus at both exposure concentrations, and the accumulation was tissue dependent. Use of the kinetic model showed that in the gills and remaining tissues, Cd was assimilated faster at the beginning of the exposure and decreased with time, possibly limited by the diffusion rate of this metal within the cell. In the digestive gland, however, the Cd was continuously accumulated. This could reflect that the Cd uptake rate is considerably higher than the loss rate and, therefore, that this tissue has a higher capacity to accumulate Cd compared to the other two tissues. Moreover, the application of this kinetic model in the different subcellular fractions showed that the bioconcentration factor was significantly higher in the low-molecular-weight fraction (where MT is found), suggesting that this fraction binds Cd faster, with a high uptake rate (K(u) = 32/d), and eliminates this metal more slowly (K(1) = 0.005/d). During the depuration phase, MT decreased simultaneously with Cd elimination in all tissues, although with a shorter half-life. In conclusion, the MT response prevented Cd in the tissues of R. decussatus from interfering in the normal clam metabolism; therefore, MT acts as a detoxification mechanism of Cd.

Reactive oxygen species and fatigue-induced prolonged low-frequency force depression in skeletal muscle fibres of rats, mice and SOD2 overexpressing mice.

PubMed

Bruton, Joseph D; Place, Nicolas; Yamada, Takashi; Silva, José P; Andrade, Francisco H; Dahlstedt, Anders J; Zhang, Shi-Jin; Katz, Abram; Larsson, Nils-Göran; Westerblad, Håkan

2008-01-01

Skeletal muscle often shows a delayed force recovery after fatiguing stimulation, especially at low stimulation frequencies. In this study we focus on the role of reactive oxygen species (ROS) in this fatigue-induced prolonged low-frequency force depression. Intact, single muscle fibres were dissected from flexor digitorum brevis (FDB) muscles of rats and wild-type and superoxide dismutase 2 (SOD2) overexpressing mice. Force and myoplasmic free [Ca(2+)] ([Ca(2+)](i)) were measured. Fibres were stimulated at different frequencies before and 30 min after fatigue induced by repeated tetani. The results show a marked force decrease at low stimulation frequencies 30 min after fatiguing stimulation in all fibres. This decrease was associated with reduced tetanic [Ca(2+)](i) in wild-type mouse fibres, whereas rat fibres and mouse SOD2 overexpressing fibres instead displayed a decreased myofibrillar Ca(2+) sensitivity. The SOD activity was approximately 50% lower in wild-type mouse than in rat FDB muscles. Myoplasmic ROS increased during repeated tetanic stimulation in rat fibres but not in wild-type mouse fibres. The decreased Ca(2+) sensitivity in rat fibres could be partially reversed by application of the reducing agent dithiothreitol, whereas the decrease in tetanic [Ca(2+)](i) in wild-type mouse fibres was not affected by dithiothreitol or the antioxidant N-acetylcysteine. In conclusion, we describe two different causes of fatigue-induced prolonged low-frequency force depression, which correlate to differences in SOD activity and ROS metabolism. These findings may have clinical implications since ROS-mediated impairments in myofibrillar function can be counteracted by reductants and antioxidants, whereas changes in SR Ca(2+) handling appear more resistant to interventions.

Characterization of the rubber tree metallothionein family reveals a role in mitigating the effects of reactive oxygen species associated with physiological stress.

PubMed

Huang, Yacheng; Fang, Yongjun; Long, Xiangyu; Liu, Linya; Wang, Jia; Zhu, Jinheng; Ma, Yanyan; Qin, Yunxia; Qi, Jiyan; Hu, Xinwen; Tang, Chaorong

2018-06-01

Metallothioneins (MTs) as reactive oxygen species (ROS) scavengers play important roles in stress response and heavy metal homeostasis. In Hevea brasiliensis (the para rubber tree that is the source of commercial natural rubber) and in other trees, the functions of MTs are not well understood. Latex exudes when the rubber tree is tapped. The flow of latex and its regeneration can be enhanced by tapping, wounding and ethylene treatment, all of which produce ROS as a by-product. Here, we show the presence of four MT genes in H. brasiliensis, comprising three Type 2 (HbMT2, -2a and -2b) and one Type 3 (HbMT3L) isoforms, representing one of the smallest MT gene families among angiosperms. The four HbMTs exhibited distinct tissue expression patterns: HbMT2 and HbMT3L mainly in leaves, HbMT2a specifically in flowers and HbMT2b in diverse tissues. The expression of HbMT2b, an isoform present in latex, decreased significantly in the latex following the stress-inducing treatments of tapping, wounding and ethephon (an ethylene generator). The expressions of the leaf-abundant isoforms, HbMT2 and -3L were up-regulated following pathogenic fungus infection and high-temperature stress, but down-regulated by low-temperature stress. These reactions were consistent with multiple defense- and hormone-responsive cis-acting elements in the HbMT promoters. Nine transcription factors were shown to implicate in the high-temperature responsiveness of HbMT2 and -3L in leaves. Overexpression of HbMT2 in Escherichia coli enhanced the bacterium's tolerance to heavy metals and ROS, consistent with its predicted role as an ROS scavenger. Taken together, our results, along with other relevant studies, suggest an important role of HbMTs in latex regeneration as well as species adaptation via the regulation of ROS homeostasis.

The production of nitric oxide in EL4 lymphoma cells overexpressing growth hormone.

PubMed

Arnold, Robyn E; Weigent, Douglas A

2003-01-01

Growth hormone (GH) is produced by immunocompetent cells and has been implicated in the regulation of a multiplicity of functions in the immune system involved in growth and activation. However, the actions of endogenous or lymphocyte GH and its contribution to immune reactivity when compared with those of serum or exogenous GH are still unclear. In the present study, we overexpressed lymphocyte GH in EL4 lymphoma cells, which lack the GH receptor (GHR), to determine the role of endogenous GH in nitric oxide (NO) production and response to genotoxic stress. Western blot analysis demonstrated that the levels of GH increased approximately 40% in cells overexpressing GH (GHo) when compared with cells with vector alone. The results also show a substantial increase in NO production in cells overexpressing GH that could be blocked by N(G)-monomethyl-L-arginine (L-NMMA), an L-arginine analogue that competitively inhibits all three isoforms of nitric oxide synthase (NOS). No evidence was obtained to support an increase in peroxynitrite in cells overexpressing GH. Overexpression of GH increased NOS activity, inducible nitric oxide synthase (iNOS) promoter activity, and iNOS protein expression, whereas endothelial nitric oxide synthase and neuronal nitric oxide synthase protein levels were essentially unchanged. In addition, cells overexpressing GH showed increased arginine transport ability and intracellular arginase activity when compared with control cells. GH overexpression appeared to protect cells from the toxic effects of the DNA alkylating agent methyl methanesulfonate. This possibility was suggested by maintenance of the mitochondrial transmembrane potential in cells overexpressing GH when compared with control cells that could be blocked by L-NMMA. Taken together, the data support the notion that lymphocyte GH, independently of the GH receptor, may play a key role in the survival of lymphocytes exposed to stressful stimuli via the production of NO.

A rapid identification system for metallothionein proteins using expert system

PubMed Central

Praveen, Bhoopathi; Vincent, Savariar; Murty, Upadhyayula Suryanarayana; Krishna, Amirapu Radha; Jamil, Kaiser

2005-01-01

Metallothioneins (MT) are low molecular weight proteins mostly rich in cysteine residues with high metal content. Generally, MT proteins are responsible for regulating the intracellular supply of biologically essential metal ions and they protect cells from the deleterious effects of non-essential polarizable transition and post-transition metal ions. Due to their biological importance, proper characterization of MT is necessary. Here we describe a computer program (ID3 algorithm, a part of Artificial Intelligence) developed using available data for the rapid identification of MT. Tissue samples contains several low molecular weight proteins with different physical, chemical and biological characteristics. The described software solution proposes to categorize MT proteins without aromatic amino acids and high metal content. The proposed solution can be expanded to other types of proteins with specific known characteristics. PMID:17597844

The Stoichiometric Transition from Zn6Cu1-Metallothionein to Zn7-Metallothionein Underlies the Up-regulation of Metallothionein (MT) Expression

PubMed Central

Alvarez, Lydia; Gonzalez-Iglesias, Hector; Garcia, Montserrat; Ghosh, Sikha; Sanz-Medel, Alfredo; Coca-Prados, Miguel

2012-01-01

We examined the profiling of gene expression of metallothioneins (MTs) in human tissues from cadaver eyes with microarray-based analysis. All MT1 isoforms, with the exception of MT1B, were abundantly expressed in lens and corneal tissue. Along with MT1B, MT4 was not detected in any tissues. Antibodies to MT1/2 labeled the corneal epithelial and endothelial cells, whereas MT3 label the retinal ganglion cells. We studied the effects of zinc and cytokines on the gene expression of MT isoforms in a corneal epithelial cell line (HCEsv). Zinc exerted an up-regulation of the expression of MT isoforms, and this effect was further potentiated in the presence of IL1α or TNFα. Zinc also elicited a strong down-regulation of the expression of inflammatory cytokines, and this effect was blocked in the presence of TNFα or IL1α. The concentration of MTs, bound zinc, and the metal stoichiometry of MTs in cultured HCEsv were determined by mass spectrometry. The total concentration of MTs was 0.24 ± 0.03 μm and, after 24 h of zinc exposure, increased to 0.96 ± 0.01 μm. The combination of zinc and IL1α further enhanced the level of MTs to 1.13 ± 0.03 μm. The average metal stoichiometry of MTs was Zn6Cu1-MT, and after exposure to the different treatments, it changed to Zn7-MT. Actinomycin D blocked transcription, and cycloheximide attenuated synthesis of MTs in the presence or absence of zinc, suggesting transcriptional regulation. Overall the data provide molecular and analytical evidence on the interplay between zinc, MTs, and proinflammatory cytokines in HCEsv cells, with potential implications on cell-based inflammatory eye diseases. PMID:22722935

Cell Surface Display of Four Types of Solanum nigrum Metallothionein on Saccharomyces cerevisiae for Biosorption of Cadmium.

PubMed

Wei, Qinguo; Zhang, Honghai; Guo, Dongge; Ma, Shisheng

2016-05-28

We displayed four types of Solanum nigrum metallothionein (SMT) for the first time on the surface of Saccharomyces cerevisiae using an α-agglutinin-based display system. The SMT genes were amplified by RT-PCR. The plasmid pYES2 was used to construct the expression vector. Transformed yeast strains were confirmed by PCR amplification and custom sequencing. Surface-expressed metallothioneins were indirectly indicated by the enhanced cadmium sorption capacity. Flame atomic absorption spectrophotometry was used to examine the concentration of Cd(2+) in this study. The transformed yeast strains showed much higher resistance ability to Cd(2+) compared with the control. Strikingly, their Cd(2+) accumulation was almost twice as much as that of the wild-type yeast cells. Furthermore, surface-engineered yeast strains could effectively adsorb ultra-trace cadmium and accumulate Cd(2+) under a wide range of pH levels, from 3 to 7, without disturbing the Cu(2+) and Hg(2+). Four types of surfaceengineered Saccharomyces cerevisiae strains were constructed and they could be used to purify Cd(2+)-contaminated water and adsorb ultra-trace cadmium effectively. The surface-engineered Saccharomyces cerevisiae strains would be useful tools for the bioremediation and biosorption of environmental cadmium contaminants.

Expression pattern of a type-2 metallothionein gene in a wild population of the psammophyte Silene nicaeensis.

PubMed

Cozza, Radiana; Bruno, Leonardo; Bitonti, Maria Beatrice

2013-02-01

Silene nicaeensis is a wild Mediterranean grass often restricted to sandy sea shore and exhibiting an excellent tolerance to drought and salinity. Within Silene genus, several heavy metal-tolerant ecotypes have been identified, but information on molecular basis of such metal tolerance is still limited. Conceivably, salt-tolerant plants may represent a powerful tool for the remediation of heavy metal contaminated sites in saline environment. Here, a gene encoding a metallothionein protein was isolated from S. nicaeensis. Sequence analysis identified the motifs characteristic of type II metallothionein and designated as SnMT2. SnMT2 expression was investigated in plants collected from two sites differing in Metal Pollution Index (MPI). SnMT2 expression by polymerase chain reaction-based semi-quantitative transcript analysis showed a high accumulation in the leaves; in situ hybridization showed a steady localization of SnMT2 mRNA in the vascular bundle and in proliferating tissues. Moreover, an increase of SnMT2 was observed in the root of plants collected from area with higher MPI. The putative role of SnMT2 in metal tolerance is discussed.

Enhancement of geraniol resistance of Escherichia coli by MarA overexpression.

PubMed

Shah, Asad Ali; Wang, Chonglong; Chung, Young-Ryun; Kim, Jae-Yean; Choi, Eui-Sung; Kim, Seon-Won

2013-03-01

Improvement of a microorganism's tolerance against organic solvents is required for a microbial factory producing terpenoid based biofuels. The bacterial genes, marA, imp, cls and cti have been found to increase organic solvent tolerance. Thus, the tolerance against the following terpenoids (isopentenol, geraniol, myrcene, and farnesol) was studied with overexpression of marA, imp, cls and cti genes in Escherichia coli. The marA overexpression significantly enhanced the tolerance of E. coli against geraniol, whereas there was no tolerance improvement against the terpenoids by overexpression of cls and cti genes. The imp overexpression even yielded sensitive phenotype to the tested solvents. The colony forming efficiency of the marA overexpressing E. coli was increased by 10(4)-fold in plate overlay of geraniol compared to that of wild type E. coli and a two-fold decrease of intracellular geraniol accumulation was also observed in liquid culture of geraniol. Single knock-out mutations of marA, or one of the following genes (acrA, acrB and tolC) encoding AcrAB-TolC efflux pump made E. coli hypersensitive to geraniol. The geraniol tolerance conferred by marA overexpression was attributed to the AcrAB-TolC efflux pump that is activated by MarA. Copyright © 2012 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Zinc and Metallothionein in the Development and Progression of Dental Caries.

PubMed

Rahman, Mohammad Tariqur; Hossain, Ashfaque; Pin, Chew Hooi; Yahya, Noor Azlin

2018-05-09

Chronic oxidative stress and reactive oxygen species (ROS) in oral cavity as well as acidic pH on dental enamel surface due to the metabolic activities of bacterial plaque are the major contributors in the development and progression of dental caries. Along with other factors, deposition or dissolution Ca and Mg mostly determines the re- or demineralization of dental enamel. Zn plays an important role for both Ca and Mg bioavailability in oral cavity. Metallothionein (MT), a group of small molecular weight, cysteine-rich proteins (~ 7 kDa), is commonly induced by ROS, bacterial infection, and Zn. In the current review, we evaluated MT at the junction between the progression of dental caries and its etiologies that are common in MT biosynthesis.

Hyaluronan synthase 3 (HAS3) overexpression downregulates MV3 melanoma cell proliferation, migration and adhesion

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

Takabe, Piia, E-mail: piia.takabe@uef.fi; Bart, Geneviève; Ropponen, Antti

2015-09-10

Malignant skin melanoma is one of the most deadly human cancers. Extracellular matrix (ECM) influences the growth of malignant tumors by modulating tumor cells adhesion and migration. Hyaluronan is an essential component of the ECM, and its amount is altered in many tumors, suggesting an important role for hyaluronan in tumorigenesis. Nonetheless its role in melanomagenesis is not understood. In this study we produced a MV3 melanoma cell line with inducible expression of the hyaluronan synthase 3 (HAS3) and studied its effect on the behavior of the melanoma cells. HAS3 overexpression expanded the cell surface hyaluronan coat and decreased melanomamore » cell adhesion, migration and proliferation by cell cycle arrest at G1/G0. Melanoma cell migration was restored by removal of cell surface hyaluronan by Streptomyces hyaluronidase and by receptor blocking with hyaluronan oligosaccharides, while the effect on cell proliferation was receptor independent. Overexpression of HAS3 decreased ERK1/2 phosphorylation suggesting that inhibition of MAP-kinase signaling was responsible for these suppressive effects on the malignant phenotype of MV3 melanoma cells. - Highlights: • Inducible HAS3-MV3 melanoma cell line was generated using Lentiviral transduction. • HAS3 overexpression inhibits MV3 cell migration via hyaluronan–receptor interaction. • HAS3 overexpression decreases MV3 melanoma cell proliferation and adhesion. • ERK1/2 phosphorylation is downregulated by 50% in HAS3 overexpressing cells. • The results suggest that hyaluronan has anti-cancer like effects in melanoma.« less

Neuroprotective effects of metallothionein against rotenone-induced myenteric neurodegeneration in parkinsonian mice.

PubMed

Murakami, Shinki; Miyazaki, Ikuko; Sogawa, Norio; Miyoshi, Ko; Asanuma, Masato

2014-10-01

Parkinson's disease (PD) is a neurodegenerative disease with motor symptoms as well as non-motor symptoms that precede the onset of motor symptoms. Mitochondrial complex I inhibitor, rotenone, has been widely used to reproduce PD pathology in the central nervous system (CNS) and enteric nervous system (ENS). We reported previously that metallothioneins (MTs) released from astrocytes can protect dopaminergic neurons against oxidative stress. The present study examined the changes in MT expression by chronic systemic rotenone administration in the striatum and colonic myenteric plexus of C57BL mice. In addition, we investigated the effects of MT depletion on rotenone-induced neurodegeneration in CNS and ENS using MT-1 and MT-2 knockout (MT KO) mice, or using primary cultured neurons from MT KO mice. In normal C57BL mice, subcutaneous administration of rotenone for 6 weeks caused neurodegeneration, increased MT expression with astrocytes activation in the striatum and myenteric plexus. MT KO mice showed more severe myenteric neuronal damage by rotenone administration after 4 weeks than wild-type mice, accompanied by reduced astroglial activation. In primary cultured mesencephalic neurons from MT KO mice, rotenone exposure induced neurotoxicity in dopaminergic neurons, which was complemented by addition of recombinant protein. The present results suggest that MT seems to provide protection against neurodegeneration in ENS of rotenone-induced PD model mice.

Knockdown of metallothionein 1 and 2 does not affect atrophy or oxidant activity in a novel in vitro model.

PubMed

Hyldahl, Robert D; O'Fallon, Kevin S; Schwartz, Lawrence M; Clarkson, Priscilla M

2010-11-01

Skeletal muscle atrophy is a significant health problem that results in decreased muscle size and function and has been associated with increases in oxidative stress. The molecular mechanisms that regulate muscle atrophy, however, are largely unknown. The metallothioneins (MT), a family of genes with antioxidant properties, have been found to be consistently upregulated during muscle atrophy, although their function during muscle atrophy is unknown. Therefore, we hypothesized that MT knockdown would result in greater oxidative stress and an enhanced atrophy response in C(2)C(12) myotubes subjected to serum reduction (SR), a novel atrophy-inducing stimulus. Forty-eight hours before SR, myotubes were transfected with small interfering RNA (siRNA) sequences designed to decrease MT expression. Muscle atrophy and oxidative stress were then measured at baseline and for 72 h following SR. Muscle atrophy was quantified by immunocytochemistry and myotube diameter measurements. Oxidative stress was measured using the fluorescent probe 5-(and-6)-carboxy-2',7'-dichlorodihydrofluorescein. SR resulted in a significant increase in oxidative stress and a decrease in myotube size and protein content. However, there were no differences observed in the extent of muscle atrophy or oxidant activity following MT knockdown. We therefore conclude that the novel SR model results in a strong atrophy response and an increase in oxidant activity in cultured myotubes and that knockdown of MT does not affect that response.

Immobilization of metallothionein to carbon paste electrode surface via anti-MT antibodies and its use for biosensing of silver.

PubMed

Trnkova, Libuse; Krizkova, Sona; Adam, Vojtech; Hubalek, Jaromir; Kizek, Rene

2011-01-15

In this paper, heavy metal biosensor based on immobilization of metallothionein (MT) to the surface of carbon paste electrode (CPE) via anti-MT-antibodies is reported. First, the evaluation of MT electroactivity was done. The attention was focused on the capturing of MT to the CPE surface. Antibodies incorporated and mixed into carbon paste were stable; even after two weeks the observed changes in signal height were lower than 5%. Further, the interaction of MT with polyclonal chicken antibodies incorporated in carbon paste electrode was determined by square-wave voltammetry. In the voltammogram, two signals--labelled as cys(MT) and W(a)--were observed. The cys(MT) corresponded to -SH moieties of MT and W(a) corresponded to tryptophan residues of chicken antibodies. Time of interaction (300 s) and MT concentration (125 μg/ml) were optimized to suggest a silver(I) ions biosensor. Biosensor (CPE modified with anti-MT antibody) prepared under the optimized conditions was then used for silver(I) ions detection. The detection limit (3 S/N) for silver(I) ions was estimated as 0.5 nM. The proposed biosensor was tested by detection spiking of silver(I) ions in various water samples (from very pure distilled water to rainwater). Recoveries varied from 74 to 104%. Copyright © 2010 Elsevier B.V. All rights reserved.

Evaluation of metallothionein formation as a proxy for zinc absorption in an in vitro digestion/caco-2 cell culture model

USDA-ARS?s Scientific Manuscript database

Caco-2 cell metallothionein (MT) formation was studied to determine if MT could be used as a proxy for zinc (Zn) absorption in a cell culture model. MT intracellular concentration was determined by using a cadmium/hemoglobin affinity assay. Cellular Zn uptake was determined in acid digests (5% HNO3)...

Arsenic trioxide (ATO) influences the gene expression of metallothioneins in human glioblastoma cells.

PubMed

Falnoga, Ingrid; Zelenik Pevec, Andreja; Šlejkovec, Zdenka; Žnidarič, Magda Tušek; Zajc, Irena; Mlakar, Simona Jurković; Marc, Janja

2012-12-01

Arsenic trioxide (As(2)O(3); ATO, TRISENOX®) is used to treat patients with refractory or relapsed acute promyelocytic leukaemia while its application for treatment of solid cancers like glioblastoma is still under evaluation. In the present study, we investigated the interaction of arsenic trioxide with metallothionein (MT) isoforms as a possible (protective response) resistance of glioblastoma cells to arsenic-induced cytotoxicity. Special attention was focused on MT3, the isoform expressed mainly in the brain. MT3 has low metal inducibility, fast metal binding/releasing properties and outstanding neuronal inhibitory activity. The human astrocytoma (glioblastoma) cell line U87 MG was treated with 0.6, 2 and 6-7 μM arsenic (equivalent to 0.3, 1 and 3-3.5 μM As(2)O(3)) for 12, 24 or 48 h and gene expression for different MT isoforms, namely MT2A, MT1A, MT1F, MT1X, MT1E and MT3, was measured by real time qPCR using SYBR Green I and Taqman® gene expression assays. TfR, 18S rRNA, GAPDH and AB were tested as reference genes, and the last two evaluated to be appropriate in conditions of low (GAPDH) and high (AB) arsenic exposure. The gene expression of MT3 gene was additionally tested and confirmed by restriction enzyme analysis with PvuII. In the given conditions the mRNAs of six MT isoforms were identified in human glioblastoma cell line U87 MG. Depending on arsenic exposure conditions, an increase or decrease of MT gene expression was observed for each isoform, with the highest increase for isoforms MT1X, MT1F and MT2A mRNA (up to 13-fold) and more persistent decreases for MT1A, MT1E and MT3 mRNA. Despite the common assumption of the noninducibility of MT3, the evident MT3 mRNA increase was observed during high As exposure (up to 4-fold). In conclusion, our results clearly demonstrate the influence of As on MT isoform gene expression. The MT1X, MT1F and MT2A increase could represent brain tumour acquired resistance to As cytotoxicity while the MT3 increase is

Overexpression of hTERT increases stem-like properties and decreases spontaneous differentiation in human mesenchymal stem cell lines

PubMed Central

2010-01-01

To overcome loss of stem-like properties and spontaneous differentiation those hinder the expansion and application of human mesenchymal stem cells (hMSCs), we have clonally isolated permanent and stable human MSC lines by ectopic overexpression of primary cell cultures of hMSCs with HPV 16 E6E7 and human telomerase reverse transcriptase (hTERT) genes. These cells were found to have a differentiation potential far beyond the ordinary hMSCs. They expressed trophoectoderm and germline specific markers upon differentiation with BMP4 and retinoic acid, respectively. Furthermore, they displayed higher osteogenic and neural differentiation efficiency than primary hMSCs or hMSCs expressed HPV16 E6E7 alone with a decrease in methylation level as proven by a global CpG island methylation profile analysis. Notably, the demethylated CpG islands were highly associated with development and differentiation associated genes. Principal component analysis further pointed out the expression profile of the cells converged toward embryonic stem cells. These data demonstrate these cells not only are a useful tool for the studies of cell differentiation both for the mesenchymal and neurogenic lineages, but also provide a valuable source of cells for cell therapy studies in animal models of skeletal and neurological disorders. PMID:20670406

Overexpression of xeroderma pigmentosum group C decreases the chemotherapeutic sensitivity of colorectal carcinoma cells to cisplatin.

PubMed

Zhang, Yi; Cao, Jia; Meng, Yanni; Qu, Chunying; Shen, Feng; Xu, Leiming

2018-05-01

Xeroderma pigmentosum group C (XPC) is a DNA-damage-recognition gene active at the early stage of DNA repair. XPC also participates in regulation of cell-cycle checkpoint and DNA-damage-induced apoptosis. In the present study, the expression levels of genes involved in nucleotide excision repair (NER) were assessed in human colorectal cancer (CRC) tissue. This analysis revealed that expression of XPC mRNA significantly increased in colorectal carcinoma tissues compared with matched normal controls. Expression of XPC gradually increased along with the degree of progression of CRC. In vitro , an XTT assay demonstrated that small interfering RNA (siRNA) targeting XPC significantly increased the sensitivity of CRC SW480 cells to cisplatin, whereas cells transfected with a XPC-overexpression plasmid became more resistant to cisplatin. Furthermore, flow cytometry revealed that the proportion of apoptotic cells significantly increased in XPC-knockdown cells upon cisplatin treatment. However, the overexpression XPC significantly increased the resistance of cells to cisplatin. In vivo , tumor growth was significantly reduced in tumor-bearing mice when the XPC gene was knocked down. Upregulation of the expression of pro-apoptotic Bcl-associated X and downregulation of the anti-apoptotic B-cell lymphoma 2 proteins was observed in the implanted tumor tissue. In conclusion, XPC serves a key role in chemotherapeutic sensitivity of CRC to cisplatin, meaning that it may be a potential target for chemotherapy of CRC.

Overexpression of miR-133 decrease primary endothelial cells proliferation and migration via FGFR1 targeting.

PubMed

Zomorrod, Mina Soufi; Kouhkan, Fatemeh; Soleimani, Masoud; Aliyan, Amir; Tasharrofi, Nooshin

2018-03-30

Angiogenesis is one of the essential hallmarks of cancer that is controlled by the balance between positive and negative regulators. FGFR1 signaling is crucial for the execution of bFGF-induced proliferation, migration, and tube formation of endothelial cells (ECs) and onset of angiogenesis on tumors. The purpose of this study is to identify whether or not miR-133 regulates FGFR1 expression and accordingly hypothesize if it plays a crucial role in modulating bFGF/FGFR1 activity in ECs and blocking tumor angiogenesis through targeting FGFR1. The influences of miR-133 overexpression on bFGF stimulated endothelial cells were assessed by cell growth curve, MTT assaying, tube formation, and migration assays. Forced expression of miR-133 caused significant reductions in bFGF-induced proliferation and migratory ability of ECs. MiR-133 Expression was negatively correlated with both mRNA and protein levels of FGFR1 in the transfected ECs isolated from peripheral blood. Moreover, overexpression of miR-133 drastically reduced the rate of cell division and disturbed capillary network formation of transfected ECs. These findings suggest that miR-133 plays an important function in bFGF-induced angiogenesis processes in ECs and provides a rationale for new therapeutic approaches to suppress tumor angiogenesis and cancer. Copyright © 2018. Published by Elsevier Inc.

Toscana Virus NSs Protein Inhibits the Induction of Type I Interferon by Interacting with RIG-I

PubMed Central

Gori-Savellini, Gianni; Valentini, Melissa

2013-01-01

Toscana virus (TOSV) is a phlebovirus, of the Bunyaviridae family, that is responsible for central nervous system (CNS) injury in humans. Previous data have shown that the TOSV NSs protein is a gamma interferon (IFN-β) antagonist when transiently overexpressed in mammalian cells, inhibiting IRF-3 induction (G. Gori Savellini, F. Weber, C. Terrosi, M. Habjan, B. Martorelli, and M. G. Cusi, J. Gen. Virol. 92:71–79, 2011). In this study, we investigated whether an upstream sensor, which has a role in the signaling cascade leading to the production of type I IFN, was involved. We found a significant decrease in RIG-I protein levels in cells overexpressing TOSV NSs, suggesting that the nonstructural protein interacts with RIG-I and targets it for proteasomal degradation. In fact, the MG-132 proteasome inhibitor was able to restore IFN-β promoter activation in cells expressing NSs, demonstrating the existence of an evasion mechanism based on inhibition of the RIG-I sensor. Furthermore, a C-terminal truncated NSs protein (ΔNSs), although able to interact with RIG-I, did not affect the RIG-I-mediated IFN-β promoter activation, suggesting that the NSs domains responsible for RIG-I-mediated signaling and interaction with RIG-I are mapped on different regions. These results contribute to identify a novel mechanism for bunyaviruses by which TOSV NSs counteracts the early IFN response. PMID:23552410

Toscana virus NSs protein inhibits the induction of type I interferon by interacting with RIG-I.

PubMed

Gori-Savellini, Gianni; Valentini, Melissa; Cusi, Maria Grazia

2013-06-01

Toscana virus (TOSV) is a phlebovirus, of the Bunyaviridae family, that is responsible for central nervous system (CNS) injury in humans. Previous data have shown that the TOSV NSs protein is a gamma interferon (IFN-β) antagonist when transiently overexpressed in mammalian cells, inhibiting IRF-3 induction (G. Gori Savellini, F. Weber, C. Terrosi, M. Habjan, B. Martorelli, and M. G. Cusi, J. Gen. Virol. 92:71-79, 2011). In this study, we investigated whether an upstream sensor, which has a role in the signaling cascade leading to the production of type I IFN, was involved. We found a significant decrease in RIG-I protein levels in cells overexpressing TOSV NSs, suggesting that the nonstructural protein interacts with RIG-I and targets it for proteasomal degradation. In fact, the MG-132 proteasome inhibitor was able to restore IFN-β promoter activation in cells expressing NSs, demonstrating the existence of an evasion mechanism based on inhibition of the RIG-I sensor. Furthermore, a C-terminal truncated NSs protein (ΔNSs), although able to interact with RIG-I, did not affect the RIG-I-mediated IFN-β promoter activation, suggesting that the NSs domains responsible for RIG-I-mediated signaling and interaction with RIG-I are mapped on different regions. These results contribute to identify a novel mechanism for bunyaviruses by which TOSV NSs counteracts the early IFN response.

Short-term exposure of mice to gasoline vapor increases the metallothionein expression in the brain, lungs and kidney.

PubMed

Grebić, D; Jakovac, H; Mrakovcić-Sutić, I; Tomac, J; Bulog, A; Micović, V; Radosević-Stasić, B

2007-06-01

Environmental airborne pollution has been repeatedly shown to affect multiple aspects of brain and cardiopulmonary function, leading to cognitive and behavioral changes and to the pronounced inflammatory response in the respiratory airways. Since in the cellular defense system the important role might have stress proteins-metallothionein (MT)-I and MT-II, which are involved in sequestration and dispersal of metal ions, regulation of the biosynthesis and activities of zinc-dependent transcription factors, as well as in cellular protection from reactive oxygen species, genotoxicity and apoptosis, in this study we investigated their expression in the brain, lungs and kidney, following intermittent exposure of mice to gasoline vapor. Control groups consisted of intact mice and of those closed in the metabolic chamber and ventilated with fresh air. The data obtained by immunohistochemistry showed that gasoline inhalation markedly upregulated the MTs expression in tissues which were directly or indirectly exposed to toxic components, significantly increasing the number of MT I+II positive cells in CNS (the entorhinal cortex, ependymal cells, astroglial cells in subventricular zone and inside the brain parenchyma, subgranular and CA1-CA3 zone of the dentate gyrus in hippocampus and macrophages-like cells in perivascular spaces), in the lungs (pneumocytes type I and type II) and in the kidneys (parietal wall of Bowman capsule, proximal and distal tubules). The data point to the protective and growth-regulatory effects of MT I + II on places of injuries, induced by inhalation of gasoline vapor.

Regulation of zinc homeostasis by inducible NO synthase-derived NO: nuclear metallothionein translocation and intranuclear Zn2+ release.

PubMed

Spahl, Daniela U; Berendji-Grün, Denise; Suschek, Christoph V; Kolb-Bachofen, Victoria; Kröncke, Klaus-D

2003-11-25

Zn2+ is critical for the functional and structural integrity of cells and contributes to a number of important processes including gene expression. It has been shown that NO exogenously applied via NO donors resulting in nitrosative stress leads to cytoplasmic Zn2+ release from the zinc storing protein metallothionein (MT) and probably other proteins that complex Zn2+ via cysteine thiols. We show here that, in cytokine-activated murine aortic endothelial cells, NO derived from the inducible NO synthase (iNOS) induces a transient nuclear release of Zn2+. This nuclear Zn2+ release depends on the presence of MT as shown by the lack of this effect in activated endothelial cells from MT-deficient mice and temporally correlates with nuclear MT translocation. Data also show that NO is an essential but not sufficient signal for MT-mediated Zn2+ trafficking from the cytoplasm into the nucleus. In addition, we found that, endogenously via iNOS, synthesized NO increases the constitutive mRNA expression of both MT-1 and MT-2 genes and that nitrosative stress exogenously applied via an NO donor increases constitutive MT mRNA expression via intracellular Zn2+ release. In conclusion, we here provide evidence for a signaling mechanism based on iNOS-derived NO through the regulation of intracellular Zn2+ trafficking and homeostasis.

Regulation of zinc homeostasis by inducible NO synthase-derived NO: Nuclear metallothionein translocation and intranuclear Zn2+ release

PubMed Central

Spahl, Daniela U.; Berendji-Grün, Denise; Suschek, Christoph V.; Kolb-Bachofen, Victoria; Kröncke, Klaus-D.

2003-01-01

Zn2+ is critical for the functional and structural integrity of cells and contributes to a number of important processes including gene expression. It has been shown that NO exogenously applied via NO donors resulting in nitrosative stress leads to cytoplasmic Zn2+ release from the zinc storing protein metallothionein (MT) and probably other proteins that complex Zn2+ via cysteine thiols. We show here that, in cytokine-activated murine aortic endothelial cells, NO derived from the inducible NO synthase (iNOS) induces a transient nuclear release of Zn2+. This nuclear Zn2+ release depends on the presence of MT as shown by the lack of this effect in activated endothelial cells from MT-deficient mice and temporally correlates with nuclear MT translocation. Data also show that NO is an essential but not sufficient signal for MT-mediated Zn2+ trafficking from the cytoplasm into the nucleus. In addition, we found that, endogenously via iNOS, synthesized NO increases the constitutive mRNA expression of both MT-1 and MT-2 genes and that nitrosative stress exogenously applied via an NO donor increases constitutive MT mRNA expression via intracellular Zn2+ release. In conclusion, we here provide evidence for a signaling mechanism based on iNOS-derived NO through the regulation of intracellular Zn2+ trafficking and homeostasis. PMID:14617770

Protection against vascular leak in neprilysin transgenic mice with complex overexpression pattern.

PubMed

Wick, Marilee J; Loomis, Zoe L; Harral, Julie W; Le, Mysan; Wehling, Carol A; Miller, York E; Dempsey, Edward C

2016-12-01

Neprilysin (NEP) is a cell surface metallopeptidase found in many tissues. Based mostly on pharmacological manipulations, NEP has been thought to protect blood vessels from plasma extravasation. We have suggested that NEP may protect against pulmonary vascular injury. However, these prior studies did not utilize mice which overexpress NEP. The aims of the present investigation were to develop and characterize doubly transgenic (DT) mice that overexpress NEP universally and conditionally, and to investigate the protective effect that overexpressed NEP may have against plasma extravasation in the vasculature. The duodenum, which is often used to assess vascular permeability, and in which the NEP protein was overexpressed in our DT mice two-fold, was selected as our experimental preparation. We found that substance P-induced plasma extravasation was decreased substantially (3.5-fold) in the duodenums of our doxycycline-treated DT mice, giving independent evidence of NEP's protective effects against plasma extravasation. Transgenic lung NEP protein was not stably expressed in the DT mice, so we were not able to test the effect of NEP overexpression in the lung. Although initially overexpressed nearly nine-fold at that site, pulmonary NEP protein overexpression eventually dissipated. Surprisingly, at a time when there was no lung transgenic NEP protein overexpression, lung NEP mRNA expression was still increased 23-fold, indicating that the expression defect probably is not transcriptional. These studies help to characterize our complex transgenic model of NEP overexpression and further demonstrate NEP's protective effects against plasma extravasation.

Notch3 overexpression enhances progression and chemoresistance of urothelial carcinoma.

PubMed

Zhang, Heng; Liu, Limei; Liu, Chungang; Pan, Jinhong; Lu, Gensheng; Zhou, Zhansong; Chen, Zhiwen; Qian, Cheng

2017-05-23

Abnormal activation of Notch signaling is involved in the etiology of various diseases, including cancer, but the association between Notch3 expression in urothelial cancer and clinical outcome remains unclear, and the molecular mechanisms underlying Notch3 signaling activation are not well defined. In this study we examined 59 urothelial cancer patients and found that Notch3 was more highly expressed in human urothelial cancer tissues than in non-tumorous bladder tissue samples, with Notch3 overexpression being associated with poor clinical outcome. Notch3 knockdown resulted in decreased proliferation of urothelial cancer cells in vitro and decreased xenograft tumor growth in vivo. In addition, Notch3 knockdown rendered urothelial cancer cells more sensitive to cisplatin. Furthermore, suberoylanilide hydroxamic acid (SAHA, a histone deacetylase [HDAC] inhibitor) induced acetylation of NOTCH3, downregulated Notch 3, prevented urothelial cancer cell proliferation, and induced cell cycle arrest. Taken together, these data suggested that Notch 3 overexpression promotes growth and chemoresistance in urothelial cancer.

Notch3 overexpression enhances progression and chemoresistance of urothelial carcinoma

PubMed Central

Zhang, Heng; Liu, Limei; Liu, Chungang; Pan, Jinhong; Lu, Gensheng; Zhou, Zhansong; Chen, Zhiwen; Qian, Cheng

2017-01-01

Abnormal activation of Notch signaling is involved in the etiology of various diseases, including cancer, but the association between Notch3 expression in urothelial cancer and clinical outcome remains unclear, and the molecular mechanisms underlying Notch3 signaling activation are not well defined. In this study we examined 59 urothelial cancer patients and found that Notch3 was more highly expressed in human urothelial cancer tissues than in non-tumorous bladder tissue samples, with Notch3 overexpression being associated with poor clinical outcome. Notch3 knockdown resulted in decreased proliferation of urothelial cancer cells in vitro and decreased xenograft tumor growth in vivo. In addition, Notch3 knockdown rendered urothelial cancer cells more sensitive to cisplatin. Furthermore, suberoylanilide hydroxamic acid (SAHA, a histone deacetylase [HDAC] inhibitor) induced acetylation of NOTCH3, downregulated Notch 3, prevented urothelial cancer cell proliferation, and induced cell cycle arrest. Taken together, these data suggested that Notch 3 overexpression promotes growth and chemoresistance in urothelial cancer. PMID:28416766

Structural consequences of metallothionein dimerization: solution structure of the isolated Cd4-alpha-domain and comparison with the holoprotein dimer.

PubMed

Ejnik, John W; Muñoz, Amalia; DeRose, Eugene; Shaw, C Frank; Petering, David H

2003-07-22

The NMR determination of the structure of Cd(7)-metallothionein was done previously using a relatively large protein concentration that favors dimer formation. The reactivity of the protein is also affected under this condition. To examine the influence of protein concentration on metallothionein conformation, the isolated Cd(4)-alpha-domain was prepared from rabbit metallothionein-2 (MT 2), and its three-dimensional structure was determined by heteronuclear, (1)H-(111)Cd, and homonuclear, (1)H-(1)H NMR, correlation experiments. The three-dimensional structure was refined using distance and angle constraints derived from these two-dimensional NMR data sets and a distance geometry/simulated annealing protocol. The backbone superposition of the alpha-domain from rabbit holoprotein Cd(7)-MT 2 and the isolated rabbit Cd(4)-alpha was measured at a RMSD of 2.0 A. Nevertheless, the conformations of the two Cd-thiolate clusters were distinctly different at two of the cadmium centers. In addition, solvent access to the sulfhydryl ligands of the isolated Cd(4)-alpha cluster was 130% larger due to this small change in cluster geometry. To probe whether these differences were an artifact of the structure calculation, the Cd(4)-alpha-domain structure in rabbit Cd(7)-MT 2 was redetermined, using the previously defined set of NOEs and the present calculation protocol. All calculations employed the same ionic radius for Cd(2+) and same cadmium-thiolate bond distance. The newly calculated structure matched the original with an RMSD of 1.24 A. It is hypothesized that differences in the two alpha-domain structures result from a perturbation of the holoprotein structure because of head-to-tail dimerization under the conditions of the NMR experiments.

Overexpression of HvHGGT Enhances Tocotrienol Levels and Antioxidant Activity in Barley.

PubMed

Chen, Jianshu; Liu, Cuicui; Shi, Bo; Chai, Yuqiong; Han, Ning; Zhu, Muyuan; Bian, Hongwu

2017-06-28

Vitamin E is a potent lipid-soluble antioxidant and essential nutrient for human health. Tocotrienols are the major form of vitamin E in seeds of most monocots. It has been known that homogentisate geranylgeranyl transferase (HGGT) catalyzes the committed step of tocotrienol biosynthesis. In the present study, we generated transgenic barley overexpressing HvHGGT under endogenous D-Hordein promoter (proHor). Overexpression of HvHGGT increased seed size and seed weight in transgenic barley. Notably, total tocotrienol content increased by 10-15% in seeds of transgenic lines, due to the increased levels of δ-, β-, and γ-tocotrienol, but not α-tocotrienol. Total tocopherol content decreased by 14-18% in transgenic lines, compared to wild type. The antioxidant activity of seeds was determined by using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), and lipid peroxidation assays. Compared to wild type, radical scavenging activity of seed extracts was enhanced by 17-18% in transgenic lines. Meanwhile, the lipid peroxidation level was decreased by about 20% in transgenic barley seeds. Taken together, overexpression of HvHGGT enhanced the tocotrienol levels and antioxidant capacity in barley seeds.

Regulation of Intracellular Copper by Induction of Endogenous Metallothioneins Improves the Disease Course in a Mouse Model of Amyotrophic Lateral Sclerosis.

PubMed

Tokuda, Eiichi; Watanabe, Shunsuke; Okawa, Eriko; Ono, Shin-ichi

2015-04-01

Mutations in SOD1 cause amyotrophic lateral sclerosis (ALS), an incurable motor neuron disease. The pathogenesis of the disease is poorly understood, but intracellular copper dyshomeostasis has been implicated as a key process in the disease. We recently observed that metallothioneins (MTs) are an excellent target for the modification of copper dyshomeostasis in a mouse model of ALS (SOD1(G93A)). Here, we offer a therapeutic strategy designed to increase the level of endogenous MTs. The upregulation of endogenous MTs by dexamethasone, a synthetic glucocorticoid, significantly improved the disease course and rescued motor neurons in SOD1(G93A) mice, even if the induction was initiated when peak body weight had decreased by 10%. Neuroprotection was associated with the normalization of copper dyshomeostasis, as well as with decreased levels of SOD1(G93A) aggregates. Importantly, these benefits were clearly mediated in a MT-dependent manner, as dexamethasone did not provide any protection when endogenous MTs were abolished from SOD1(G93A) mice. In conclusion, the upregulation of endogenous MTs represents a promising strategy for the treatment of ALS linked to mutant SOD1.

Monitoring in real time the effect of TLX overexpression on proliferation and migration of C6 cells.

PubMed

Li, G L; Fang, S H; Xu, B

2017-01-01

Orphan nuclear receptor TLX has been shown to play an essential role in regulating the self-renewal and proliferation of neural stem cells (NSCs). However, TLX overexpression in NSCs induces long-term NSC expansion and further leads to glioma initiation in mouse when combined with p53 mutations. Whether overexpression of TLX plays a role in glioma stem cell (GSC) proliferation and migration still remains largely unknown. In this study, we infected C6 cells, a special glioma cell line which is mainly composed of cancer stem cells(CSCs), with lentiviruses expressing GFP(LV-GFP) or GFP-T2A-TLX(LV-TLX) and then monitored cell proliferation and migration using the real-time analyzer system (RTCA, xCELLigence, Roche). We found that the cell index (CI) observed for the TLX overexpressing C6 cells showed a lower value than that of the LV-GFP transduced cells. And the MTT results correlated highly with the RTCA proliferation assessments. Furthermore, the expression of p21 was decreased while other downstream genes PTEN and p53 were not significantly changed in TLX overexpressing C6 cells . These findings strongly indicate that TLX overexpression has the ability to decrease the proliferating and migratory properties of C6 cells by targeting p21. Further, our results suggest that TLX overexpression may also have a similar inhibitory effect on GSC proliferation and migration.

Overexpression of xeroderma pigmentosum group C decreases the chemotherapeutic sensitivity of colorectal carcinoma cells to cisplatin

PubMed Central

Zhang, Yi; Cao, Jia; Meng, Yanni; Qu, Chunying; Shen, Feng; Xu, Leiming

2018-01-01

Xeroderma pigmentosum group C (XPC) is a DNA-damage-recognition gene active at the early stage of DNA repair. XPC also participates in regulation of cell-cycle checkpoint and DNA-damage-induced apoptosis. In the present study, the expression levels of genes involved in nucleotide excision repair (NER) were assessed in human colorectal cancer (CRC) tissue. This analysis revealed that expression of XPC mRNA significantly increased in colorectal carcinoma tissues compared with matched normal controls. Expression of XPC gradually increased along with the degree of progression of CRC. In vitro, an XTT assay demonstrated that small interfering RNA (siRNA) targeting XPC significantly increased the sensitivity of CRC SW480 cells to cisplatin, whereas cells transfected with a XPC-overexpression plasmid became more resistant to cisplatin. Furthermore, flow cytometry revealed that the proportion of apoptotic cells significantly increased in XPC-knockdown cells upon cisplatin treatment. However, the overexpression XPC significantly increased the resistance of cells to cisplatin. In vivo, tumor growth was significantly reduced in tumor-bearing mice when the XPC gene was knocked down. Upregulation of the expression of pro-apoptotic Bcl-associated X and downregulation of the anti-apoptotic B-cell lymphoma 2 proteins was observed in the implanted tumor tissue. In conclusion, XPC serves a key role in chemotherapeutic sensitivity of CRC to cisplatin, meaning that it may be a potential target for chemotherapy of CRC. PMID:29616110

Overexpression of TRPV3 Correlates with Tumor Progression in Non-Small Cell Lung Cancer.

PubMed

Li, Xiaolei; Zhang, Qianhui; Fan, Kai; Li, Baiyan; Li, Huifeng; Qi, Hanping; Guo, Jing; Cao, Yonggang; Sun, Hongli

2016-03-24

(1) BACKGROUND: Transient receptor potential vanilloid 3 (TRPV3) is a member of the TRP channels family of Ca(2+)-permeant channels. The proteins of some TRP channels are highly expressed in cancer cells. This study aimed to assess the clinical significance and biological functions of TRPV3 in non-small cell lung cancer (NSCLC); (2) METHODS: Immunohistochemistry was used to detect the expression of TRPV3 in NSCLC tissues and adjacent noncancerous lung tissues. Western blot was used to detect the protein expressions of TRPV3, CaMKII, p-CaMKII, CyclinA, CyclinD, CyclinE1, CDK2, CDK4, and P27. Small interfering RNA was used to deplete TRPV3 expression. A laser scanning confocal microscope was used to measure intracellular calcium concentration ([Ca(2+)]i). Flow cytometry was used to analyze cell cycle; (3) RESULTS: TRPV3 was overexpressed in 65 of 96 (67.7%) human lung cancer cases and correlated with differentiation (p = 0.001) and TNM stage (p = 0.004). Importantly, TRPV3 expression was associated with short overall survival. In addition, blocking or knockdown of TRPV3 could inhibit lung cancer cell proliferation. Moreover, TRPV3 inhibition could decrease [Ca(2+)]i of lung cancer cells and arrest cell cycle at the G1/S boundary. Further results revealed that TRPV3 inhibition decreased expressions of p-CaMKII, CyclinA, CyclinD1, CyclinE, and increased P27 level; (4) CONCLUSIONS: Our findings demonstrate that TRPV3 was overexpressed in NSCLC and correlated with lung cancer progression. TRPV3 activation could promote proliferation of lung cancer cells. TRPV3 might serve as a potential companion drug target in NSCLC.

Overexpression of TRPV3 Correlates with Tumor Progression in Non-Small Cell Lung Cancer

PubMed Central

Li, Xiaolei; Zhang, Qianhui; Fan, Kai; Li, Baiyan; Li, Huifeng; Qi, Hanping; Guo, Jing; Cao, Yonggang; Sun, Hongli

2016-01-01

(1) Background: Transient receptor potential vanilloid 3 (TRPV3) is a member of the TRP channels family of Ca2+-permeant channels. The proteins of some TRP channels are highly expressed in cancer cells. This study aimed to assess the clinical significance and biological functions of TRPV3 in non-small cell lung cancer (NSCLC); (2) Methods: Immunohistochemistry was used to detect the expression of TRPV3 in NSCLC tissues and adjacent noncancerous lung tissues. Western blot was used to detect the protein expressions of TRPV3, CaMKII, p-CaMKII, CyclinA, CyclinD, CyclinE1, CDK2, CDK4, and P27. Small interfering RNA was used to deplete TRPV3 expression. A laser scanning confocal microscope was used to measure intracellular calcium concentration ([Ca2+]i). Flow cytometry was used to analyze cell cycle; (3) Results: TRPV3 was overexpressed in 65 of 96 (67.7%) human lung cancer cases and correlated with differentiation (p = 0.001) and TNM stage (p = 0.004). Importantly, TRPV3 expression was associated with short overall survival. In addition, blocking or knockdown of TRPV3 could inhibit lung cancer cell proliferation. Moreover, TRPV3 inhibition could decrease [Ca2+]i of lung cancer cells and arrest cell cycle at the G1/S boundary. Further results revealed that TRPV3 inhibition decreased expressions of p-CaMKII, CyclinA, CyclinD1, CyclinE, and increased P27 level; (4) Conclusions: Our findings demonstrate that TRPV3 was overexpressed in NSCLC and correlated with lung cancer progression. TRPV3 activation could promote proliferation of lung cancer cells. TRPV3 might serve as a potential companion drug target in NSCLC. PMID:27023518

Intraperitoneal implant of recombinant encapsulated cells overexpressing alpha-L-iduronidase partially corrects visceral pathology in mucopolysaccharidosis type I mice.

PubMed

Baldo, Guilherme; Mayer, Fabiana Quoos; Martinelli, Barbara; Meyer, Fabiola Schons; Burin, Maira; Meurer, Luise; Tavares, Angela Maria Vicente; Giugliani, Roberto; Matte, Ursula

2012-08-01

Mucopolysaccharidosis type I (MPS I) is characterized by deficiency of the enzyme alpha-L-iduronidase (IDUA) and storage of glycosaminoglycans (GAG) in several tissues. Current available treatments present limitations, thus the search for new therapies. Encapsulation of recombinant cells within polymeric structures combines gene and cell therapy and is a promising approach for treating MPS I. We produced alginate microcapsules containing baby hamster kidney (BHK) cells overexpressing IDUA and implanted these capsules in the peritoneum of MPS I mice. An increase in serum and tissue IDUA activity was observed at early time-points, as well as a reduction in GAG storage; however, correction in the long term was only partially achieved, with a drop in the IDUA activity being observed a few weeks after the implant. Analysis of the capsules obtained from the peritoneum revealed inflammation and a pericapsular fibrotic process, which could be responsible for the reduction in IDUA levels observed in the long term. In addition, treated mice developed antibodies against the enzyme. The results suggest that the encapsulation process is effective in the short term but improvements must be achieved in order to reduce the immune response and reach a stable correction.

Acute and subacute pulmonary toxicity caused by a single intratracheal instillation of colloidal silver nanoparticles in mice: pathobiological changes and metallothionein responses.

PubMed

Kaewamatawong, Theerayuth; Banlunara, Wijit; Maneewattanapinyo, Pattwat; Thammachareon, Chuchaat; Ekgasit, Sanong

2014-01-01

To study the acute and subacute pulmonary toxicity of colloidal silver nanoparticles (Ag-NPs), 0 or 100 ppm of Ag-NPs were instilled intratracheally in mice. Cellular and biochemical parameters in bronchoalveolar lavage fluid (BALF) and histological alterations were determined 1, 3, 7, 15, and 30 days after instillation. Ag-NPs induced moderate pulmonary inflammation and injury on BALF indices during the acute period; however, these changes gradually regressed in a time-dependent manner. Concomitant histopathological and laminin immunohistochemical findings generally correlated to BALF data. Superoxide dismutase and metallothionein expression occurred in particle-laden macrophages and alveolar epithelial cells, which correlated to lung lesions in mice treated with Ag-NPs. These findings suggest that instillation of Ag-NPs causes transient moderate acute lung inflammation and tissue damage. Oxidative stress may underlie the induction of injury to lung tissue. Moreover, the expression of metallothionein in tissues indicated the protective response to exposure to Ag-NPs.

CREB Overexpression Ameliorates Age-related Behavioral and Biophysical Deficits

NASA Astrophysics Data System (ADS)

Yu, Xiao-Wen

Age-related cognitive deficits are observed in both humans and animals. Yet, the molecular mechanisms underlying these deficits are not yet fully elucidated. In aged animals, a decrease in intrinsic excitability of pyramidal neurons from the CA1 sub-region of hippocampus is believed to contribute to age-related cognitive impairments, but the molecular mechanism(s) that modulate both these factors has yet to be identified. Increasing activity of the transcription factor cAMP response element-binding protein (CREB) in young adult rodents has been shown to facilitate cognition, and increase intrinsic excitability of their neurons. However, how CREB changes with age, and how that impacts cognition in aged animals, is not clear. Therefore, we first systematically characterized age- and training-related changes in CREB levels in dorsal hippocampus. At a remote time point after undergoing behavioral training, levels of total CREB and activated CREB (phosphorylated at S133, pCREB) were measured in both young and aged rats. We found that pCREB, but not total CREB was significantly reduced in dorsal CA1 of aged rats. Importantly, levels of pCREB were found to be positively correlated with short-term spatial memory in both young and aged rats i.e. higher pCREB in dorsal CA1 was associated with better spatial memory. These findings indicate that an age-related deficit in CREB activity may contribute to the development of age-related cognitive deficits. However, it was still unclear if increasing CREB activity would be sufficient to ameliorate age-related cognitive, and biophysical deficits. To address this question, we virally overexpressed CREB in CA1, where we found the age-related deficit. Young and aged rats received control or CREB virus, and underwent water maze training. While control aged animals exhibited deficits in long-term spatial memory, aged animals with CREB overexpression performed at levels comparable to young animals. Concurrently, aged neurons

Overexpression of cypin alters dendrite morphology, single neuron activity, and network properties via distinct mechanisms

NASA Astrophysics Data System (ADS)

Rodríguez, Ana R.; O'Neill, Kate M.; Swiatkowski, Przemyslaw; Patel, Mihir V.; Firestein, Bonnie L.

2018-02-01

Objective. This study investigates the effect that overexpression of cytosolic PSD-95 interactor (cypin), a regulator of synaptic PSD-95 protein localization and a core regulator of dendrite branching, exerts on the electrical activity of rat hippocampal neurons and networks. Approach. We cultured rat hippocampal neurons and used lipid-mediated transfection and lentiviral gene transfer to achieve high levels of cypin or cypin mutant (cypinΔPDZ PSD-95 non-binding) expression cellularly and network-wide, respectively. Main results. Our analysis revealed that although overexpression of cypin and cypinΔPDZ increase dendrite numbers and decrease spine density, cypin and cypinΔPDZ distinctly regulate neuronal activity. At the single cell level, cypin promotes decreases in bursting activity while cypinΔPDZ reduces sEPSC frequency and further decreases bursting compared to cypin. At the network level, by using the Fano factor as a measure of spike count variability, cypin overexpression results in an increase in variability of spike count, and this effect is abolished when cypin cannot bind PSD-95. This variability is also dependent on baseline activity levels and on mean spike rate over time. Finally, our spike sorting data show that overexpression of cypin results in a more complex distribution of spike waveforms and that binding to PSD-95 is essential for this complexity. Significance. Our data suggest that dendrite morphology does not play a major role in cypin action on electrical activity.

Hyaluronic Acid is Overexpressed in Fibrotic Lung Tissue and Promotes Collagen Expression

DTIC Science & Technology

2008-04-01

cause of morbidity and mortality in scleroderma . The overexpression of collagen is accompanied by the overexpression of other extracellular matrix...7 Appendices…………………………………………………………………………… 7 3 INTRODUCTION Systemic scleroderma is a debilitating disease...excessive accumulation of extracellular matrix [ECM] proteins, particularly collagen I) is the major cause of morbidity and mortality in scleroderma . The

The inhibition of superoxide production in EL4 lymphoma cells overexpressing growth hormone.

PubMed

Arnold, Robyn E; Weigent, Douglas A

2003-05-01

A substantial body of research exists to support the production of growth hormone by cells of the immune system. However, the function and mechanism of action of lymphocyte-derived growth hormone remain largely unelucidated. Since, it has been found that exogenous growth hormone (GH) primes neutrophils for the production of reactive oxygen intermediates (ROI) and in particular superoxide (O2-), we investigated the role of GH on the production of O2- in T cells. Furthermore, we examined whether endogenous and exogenous GH act similarly. Our studies show that overexpression of GH in EL4, a T-cell lymphoma cell line, results in a decrease in the production of O2- compared to control cells, as detected using the fluorescent dye, dihydroethidium. O2- production in control cells was not affected by treatment with inhibitors of xanthine oxidase or a non-specific NADPH-oxidase inhibitor. However, treatment with diallyl sulfide, an inhibitor of cytochrome P450 2E1 mimicked the reduction in O2- production seen in cells overexpressing GH. Although no significant change could be detected in CYP2E1 protein levels, CYP2E1 activity was found to be greater in control EL4 than in cells overexpressing GH. Both the decrease in O2- production and the lower CYP2E1 activity in GH overexpressing cells could be abrogated by treatment with N(G)-monomethyl-L-arginine, an inhibitor of nitric oxide synthase. The overexpression of GH protects cells from apoptosis induced by isoniazid, a CYP2E1 inducer, suggesting a role for nitric oxide as a mediator in the regulation of xenobiotic metabolism and apoptosis-protection by lymphocyte GH.

Effects of CD44 and E-cadherin overexpression on the proliferation, adhesion and invasion of ovarian cancer cells.

PubMed

Mao, Meiya; Zheng, Xiaojiao; Jin, Bohong; Zhang, Fubin; Zhu, Linyan; Cui, Lining

2017-12-01

CD44 is a prognostic indicator of shorter survival time in ovarian cancer. E-cadherin fragmentation promotes the progression of ovarian cancer. However, the effects of CD44 and E-cadherin overexpression on ovarian cancer cells have remained elusive. The present study aimed to investigate the effects of overexpression of CD44 and E-cadherin on cell proliferation, adhesion and invasion of SKOV-3 and OVCAR-3 ovarian cancer cells. Overexpression of CD44 and E-cadherin was achieved by transfecting SKOV-3 and OVCAR-3 cells with viruses carrying the CD44 or E-cadherin gene, respectively. Expression of CD44 and E-cadherin was detected by western blot analysis. The proliferation of SKOV-3 and OVCAR-3 cells was measured by a Cell Counting Kit-8 at 0, 24 and 48 h after viral transfection. The adhesion ability of SKOV-3 and OVCAR-3 cells to the endothelial layer was detected. A Transwell invasion assay was utilized to assess the invasion ability of the cells. Overexpression of CD44 and E-cadherin in SKOV-3 and OVCAR-3 cells was confirmed by western blot. Compared with the blank or negative control groups, the CD44 overexpression groups of SKOV-3 and OVCAR-3 cells exhibited an increased cell proliferation rate at 24 and 48 h, whereas overexpression of E-cadherin did not alter the proliferation of these cells. Furthermore, compared with the blank and negative control groups, the cell adhesion and invasion ability in the CD44 overexpression groups of SKOV-3 and OVCAR-3 cells was markedly higher. There were no significant differences in adhesion ability between the E-cadherin overexpression group and the blank/negative control group. Of note, overexpression of E-cadherin decreased the invasive ability of SKOV-3 and OVCAR-3 cells. In conclusion, Overexpression of CD44 increased the proliferation, adhesion and invasion of ovarian cancer cells, while overexpression of E-cadherin decreased the invasion of ovarian cancer cells.

Effect of SOCS1 overexpression on RPE cell activation by proinflammatory cytokines.

PubMed

Bazewicz, Magdalena; Draganova, Dafina; Makhoul, Maya; Chtarto, Abdel; Elmaleh, Valerie; Tenenbaum, Liliane; Caspers, Laure; Bruyns, Catherine; Willermain, François

2016-09-06

The purpose of this study was to investigate the in vitro effect of Suppressor Of Cytokine Signaling 1 (SOCS1) overexpression in retinal pigment epithelium (RPE) cells on their activation by pro-inflammatory cytokines IFNγ, TNFα and IL-17. Retinal pigment epithelium cells (ARPE-19) were stably transfected with the control plasmid pIRES2-AcGFP1 or the plasmid pSOCS1-IRES2-AcGFP1. They were stimulated by IFNγ (150ng/ml), TNFα (30ng/ml) or IL-17 (100ng/ml). The levels of SOCS1 mRNA were measured by real-time PCR. Signal Transducer and Activator of Transcription 1 (STAT1) phosphorylation and IκBα expression were analysed by western Blot (WB). IL-8 secretion was analysed by ELISA and expression of MHCII molecules and ICAM-1/CD54 by flow cytometry. Our data show that SOCS1 mRNA overexpression in RPE cells prevents IFNγ-induced SOCS1 mRNA increase and IFNγ-mediated STAT1 phosphorylation. Moreover, SOCS1 overexpression in RPE cells inhibits IFNγ-induced decrease of IL-8 secretion and prevents IFNγ-induced MHC II and ICAM1/CD54 upregulation. However, SOCS1 overexpression does not affect TNFα-induced IκBα degradation nor block TNFα-induced or IL-17-induced IL-8 secretion. On the contrary, IL-17-induced secretion is increased by SOCS1 overexpression. In conclusion, SOCS1 overexpression in RPE cells inhibits some IFNγ-mediated responses that lead to uveitis development. This notion raises the possibility that SOCS1 overexpression could be a novel target for treating non-infectious uveitis. However, some proinflammatory effects of TNFα and IL-17 stimulation on RPE are not blocked by SOCS1 overexpression. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Characterization of calcineurin-dependent response element binding protein and its involvement in copper-metallothionein gene expression in Neurospora

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

Kumar, Kalari Satish; Ravi Kumar, B.; Siddavattam, Dayananda

2006-07-07

In continuation of our recent observations indicating the presence of a lone calcineurin-dependent response element (CDRE) in the -3730 bp upstream region of copper-induced metallothionein (CuMT) gene of Neurospora [K.S. Kumar, S. Dayananda, C. Subramanyam, Copper alone, but not oxidative stress, induces copper-metallothionein gene in Neurospora crassa, FEMS Microbiol. Lett. 242 (2005) 45-50], we isolated and characterized the CDRE-binding protein. The cloned upstream region of CuMT gene was used as the template to specifically amplify CDRE element, which was immobilized on CNBr-activated Sepharose 4B for use as the affinity matrix to purify the CDRE binding protein from nuclear extracts obtainedmore » from Neurospora cultures grown in presence of copper. Two-dimensional gel electrophoresis of the affinity purified protein revealed the presence of a single 17 kDa protein, which was identified and characterized by MALDI-TOF. Peptide mass finger printing of tryptic digests and analysis of the 17 kDa protein matched with the regulatory {beta}-subunit of calcineurin (Ca{sup 2+}-calmodulin dependent protein phosphatase). Parallel identification of nuclear localization signals in this protein by in silico analysis suggests a putative role for calcineurin in the regulation of CuMT gene expression.« less

Overexpression of protein kinase C ɛ improves retention and survival of transplanted mesenchymal stem cells in rat acute myocardial infarction.

PubMed

He, H; Zhao, Z-H; Han, F-S; Liu, X-H; Wang, R; Zeng, Y-J

2016-01-21

We assessed the effects of protein kinase C ɛ (PKCɛ) for improving stem cell therapy for acute myocardial infarction (AMI). Primary mesenchymal stem cells (MSCs) were harvested from rat bone marrow. PKCɛ-overexpressed MSCs and control MSCs were transplanted into infarct border zones in a rat AMI model. MSCs and PKCɛ distribution and expression of principal proteins involved in PKCɛ signaling through the stromal cell-derived factor 1 (SDF-1)/CXC chemokine receptor type 4 (CXCR4) axis and the phosphatidylinositol 3 kinase (PI3K)/protein kinase B (AKT) pathway were analyzed by immunofluorescence and western blot 1 day after transplantation. Echocardiographic measurements and histologic studies were performed at 4 weeks after transplantation, and MSC survival, expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), transforming growth factor β (TGFβ), cardiac troponin I (cTnI), von Willebrand factor (vWF), smooth muscle actin (SMA) and factor VIII and apoptosis in infarct border zones were assessed. Rat heart muscles retained more MSCs and SDF-1, CXCR4, PI3K and phosphorylated AKT increased with PKCɛ overexpression 1 day after transplantation. MSC survival and VEGF, bFGF, TGFβ, cTnI, vWF, SMA and factor VIII expression increased in animals with PKCɛ-overexpressed MSCs at 4 weeks after transplantation and cardiac dysfunction and remodeling improved. Infarct size and apoptosis decreased as well. Inhibitory actions of CXCR4 or PI3K partly attenuated the effects of PKCɛ. Activation of PKCɛ may improve retention, survival and differentiation of transplanted MSCs in myocardia. Augmentation of PKCɛ expression may enhance the therapeutic effects of stem cell therapy for AMI.

Foot-and-mouth disease virus leader proteinase inhibits dsRNA-induced type I interferon transcription by decreasing interferon regulatory factor 3/7 in protein levels

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

Wang, Dang; Fang, Liurong; Luo, Rui

2010-08-13

Research highlights: {yields} FMDV L{sup pro} inhibits poly(I:C)-induced IFN-{alpha}1/{beta} mRNA expression. {yields} L{sup pro} inhibits MDA5-mediated activation of the IFN-{alpha}1/{beta} promoter. {yields} L{sup pro} significantly reduced the transcription of multiple IRF-responsive genes. {yields} L{sup pro} inhibits IFN-{alpha}1/{beta} promoter activation by decreasing IRF-3/7 in protein levels. {yields} The ability to process eIF-4G of L{sup pro} is not necessary to inhibit IFN-{alpha}1/{beta} activation. -- Abstract: The leader proteinase (L{sup pro}) of foot-and-mouth disease virus (FMDV) has been identified as an interferon-{beta} (IFN-{beta}) antagonist that disrupts the integrity of transcription factor nuclear factor {kappa}B (NF-{kappa}B). In this study, we showed that the reductionmore » of double stranded RNA (dsRNA)-induced IFN-{alpha}1/{beta} expression caused by L{sup pro} was also associated with a decrease of interferon regulatory factor 3/7 (IRF-3/7) in protein levels, two critical transcription factors for activation of IFN-{alpha}/{beta}. Furthermore, overexpression of L{sup pro} significantly reduced the transcription of multiple IRF-responsive genes including 2',5'-OAS, ISG54, IP-10, and RANTES. Screening L{sup pro} mutants indicated that the ability to process eIF-4G of L{sup pro} is not required for suppressing dsRNA-induced activation of the IFN-{alpha}1/{beta} promoter and decreasing IRF-3/7 expression. Taken together, our results demonstrate that, in addition to disrupting NF-{kappa}B, L{sup pro} also decreases IRF-3/7 expression to suppress dsRNA-induced type I IFN production, suggesting multiple strategies used by FMDV to counteract the immune response to viral infection.« less

Overexpression of stress-inducible OsBURP16, the β subunit of polygalacturonase 1, decreases pectin content and cell adhesion and increases abiotic stress sensitivity in rice.

PubMed

Liu, Huanhuan; Ma, Yan; Chen, Na; Guo, Siyi; Liu, Huili; Guo, Xiaoyu; Chong, Kang; Xu, Yunyuan

2014-05-01

Polygalacturonase (PG), one of the hydrolases responsible for cell wall pectin degradation, is involved in organ consenescence and biotic stress in plants. PG1 is composed of a catalytic subunit, PG2, and a non-catalytic PG1β subunit. OsBURP16 belongs to the PG1β-like subfamily of BURP-family genes and encodes one putative PG1β subunit precursor in rice (Oryza sativa L.). Transcription of OsBURP16 is induced by cold, salinity and drought stresses, as well as by abscisic acid (ABA) treatment. Analysis of plant survival rates, relative ion leakage rates, accumulation levels of H2 O2 and water loss rates of leaves showed that overexpression of OsBURP16 enhanced sensitivity to cold, salinity and drought stresses compared with controls. Young leaves of Ubi::OsBURP16 transgenic plants showed reduced cell adhesion and increased cuticular transpiration rate. Mechanical strength measurement of Ubi::OsBURP16 plants showed that reduced force was required to break leaves as compared with wild type. Transgenic rice showed enhanced PG activity and reduced pectin content. All these results suggested that overexpression of OsBURP16 caused pectin degradation and affected cell wall integrity as well as transpiration rate, which decreased tolerance to abiotic stresses. © 2013 The Authors. Plant, Cell & Environment published by John Wiley & Sons Ltd.

Overexpression of plastidial thioredoxins f and m differentially alters photosynthetic activity and response to oxidative stress in tobacco plants

PubMed Central

Rey, Pascal; Sanz-Barrio, Ruth; Innocenti, Gilles; Ksas, Brigitte; Courteille, Agathe; Rumeau, Dominique; Issakidis-Bourguet, Emmanuelle; Farran, Inmaculada

2013-01-01

Plants display a remarkable diversity of thioredoxins (Trxs), reductases controlling the thiol redox status of proteins. The physiological function of many of them remains elusive, particularly for plastidial Trxs f and m, which are presumed based on biochemical data to regulate photosynthetic reactions and carbon metabolism. Recent reports revealed that Trxs f and m participate in vivo in the control of starch metabolism and cyclic photosynthetic electron transfer around photosystem I, respectively. To further delineate their in planta function, we compared the photosynthetic characteristics, the level and/or activity of various Trx targets and the responses to oxidative stress in transplastomic tobacco plants overexpressing either Trx f or Trx m. We found that plants overexpressing Trx m specifically exhibit altered growth, reduced chlorophyll content, impaired photosynthetic linear electron transfer and decreased pools of glutathione and ascorbate. In both transplastomic lines, activities of two enzymes involved in carbon metabolism, NADP-malate dehydrogenase and NADP-glyceraldehyde-3-phosphate dehydrogenase are markedly and similarly altered. In contrast, plants overexpressing Trx m specifically display increased capacity for methionine sulfoxide reductases, enzymes repairing damaged proteins by regenerating methionine from oxidized methionine. Finally, we also observed that transplastomic plants exhibit distinct responses when exposed to oxidative stress conditions generated by methyl viologen or exposure to high light combined with low temperature, the plants overexpressing Trx m being notably more tolerant than Wt and those overexpressing Trx f. Altogether, these data indicate that Trxs f and m fulfill distinct physiological functions. They prompt us to propose that the m type is involved in key processes linking photosynthetic activity, redox homeostasis and antioxidant mechanisms in the chloroplast. PMID:24137166

Capsule Depolymerase Overexpression Reduces Bacillus anthracis Virulence

DTIC Science & Technology

2010-01-01

protein that autocatalytically forms a heterodimer consisting of 35 kDa and 15 kDa subunits. CapD shares 32 % identity with the Bacillus subtilis GGT and 35...Immun 49, 291–297. Kimura, K., Tran, L. S., Uchida, I. & Itoh, Y. (2004). Characterization of Bacillus subtilis gamma-glutamyltransferase and its...Capsule depolymerase overexpression reduces Bacillus anthracis virulence Angelo Scorpio,3 Donald J. Chabot, William A. Day,4 Timothy A. Hoover and

Increasing the starch content and grain weight of common wheat by overexpression of the cytosolic AGPase large subunit gene.

PubMed

Kang, Guozhang; Liu, Guoqin; Peng, Xiaoqi; Wei, Liting; Wang, Chenyang; Zhu, YunJi; Ma, Ying; Jiang, Yumei; Guo, Tiancai

2013-12-01

ADP-glucose pyrophosphorylase (AGPase) catalyzes the first committed step of starch synthesis. AGPase is a heterotetramer composed of two large subunits and two small subunits, has cytosolic and plastidial isoforms, and is detected mainly in the cytosol of endosperm in cereal crops. To investigate the effects of AGPase cytosolic large subunit gene (LSU I) on starch biosynthesis in higher plant, in this study, a TaLSU I gene from wheat was overexpressed under the control of an endosperm-specific promoter in a wheat cultivar (Yumai 34). PCR, Southern blot, and real-time RT-PCR analyses indicated that the transgene was integrated into the genome of transgenic plants and was overexpressed in their progeny. The overexpression of the TaLSU I gene remarkably enhanced AGPase activity, endosperm starch weight, grain number per spike, and single grain weight. Therefore, we conclude that overexpression of the TaLSU I gene enhances the starch biosynthesis in endosperm of wheat grains, having potential applications in wheat breeding to develop a high-yield wheat cultivar with high starch weight and kernel weight. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Overexpression of TIMP3 Protects Against Cardiac Ischemia/Reperfusion Injury by Inhibiting Myocardial Apoptosis Through ROS/Mapks Pathway.

PubMed

Liu, Hui; Jing, Xibo; Dong, Aiqiao; Bai, Baobao; Wang, Haiyan

2017-01-01

Myocardial ischemia/reperfusion (I/R) injury remains a great challenge in clinical therapy. Tissue inhibitor of metalloproteinases 3 (TIMP3) plays a crucial role in heart physiological and pathophysiological processes. However, the effects of TIMP3 on I/R injury remain unknown. C57BL/6 mice were infected with TIMP3 adenovirus by local delivery in myocardium followed by I/R operation or doxorubicin treatment. Neonatal rat cardiomyocytes were pretreated with TIMP3 adenovirus prior to anoxia/reoxygenation (A/R) treatment in vitro. Histology, echocardiography, in vivo phenotypical analysis, flow cytometry and western blotting were used to investigate the altered cardiac function and underlying mechanisms. The results showed that upregulation of TIMP3 in myocardium markedly inhibited myocardial infarct areas and the cardiac dysfunction induced by I/R or by doxorubicin treatment. TUNEL staining revealed that TIMP3 overexpression attenuated I/R-induced myocardial apoptosis, accompanied by decreased Bax/Bcl-2 ratio, Cleaved Caspase-3 and Cleaved Caspase-9 expression. In vitro, A/R-induced cardiomyocyte apoptosis was abrogated by pharmacological inhibition of reactive oxygen species (ROS) production or MAPKs signaling. Attenuation of ROS production reversed A/R-induced MAPKs activation, whereas MAPKs inhibitors showed on effect on ROS production. Furthermore, in vivo or in vitro overexpression of TIMP3 significantly inhibited I/R- or A/R-induced ROS production and MAPKs activation. Our findings demonstrate that TIMP3 upregulation protects against cardiac I/R injury through inhibiting myocardial apoptosis. The mechanism may be related to inhibition of ROS-initiated MAPKs pathway. This study suggests that TIMP3 may be a potential therapeutic target for the treatment of I/R injury. © 2017 The Author(s). Published by S. Karger AG, Basel.

Alkaloids in plants and root cultures of Atropa belladonna overexpressing putrescine N-methyltransferase.

PubMed

Rothe, Grit; Hachiya, Akira; Yamada, Yasuyuki; Hashimoto, Takashi; Dräger, Birgit

2003-09-01

Putrescine N-methyltransferase (PMT) is the first alkaloid-specific enzyme for nicotine and tropane alkaloid formation. The pmt gene from Nicotiana tabacum was fused to the CaMV 35S promoter and integrated into the Atropa belladonna genome. Transgenic plants and derived root cultures were analysed for gene expression and for levels of alkaloids and their precursors. Scopolamine, hyoscyamine, tropine, pseudotropine, tropinone, and calystegines were found unaltered or somewhat decreased in pmt-overexpressing lines compared to controls. When root cultures were treated with 5% sucrose, calystegine levels were elevated in control roots, but were not affected in pmt-overexpressing roots. 1 microM auxin reduced calystegine levels in control roots, while in pmt-overexpressing roots all alkaloids remained unaltered. Expression level of pmt alone is apparently not limiting for tropane alkaloid formation in A. belladonna.

Interferon-alpha-induced changes in metallothionein expression in liver biopsies from patients with chronic hepatitis C.

PubMed

Nagamine, Takeaki; Suzuki, Keiji; Kondo, Toshihiko; Nakazato, Kyomi; Kakizaki, Satoru; Takagi, Hitoshi; Nakajima, Katuyuki

2005-08-01

An association between reactive oxygen species and liver damage has been postulated in the course of hepatitis C virus (HCV) infection. Metallothionein (MT), induced by HCV core protein and interferon (IFN), plays a role in scavenging free radicals. MT expression in liver biopsies obtained from 21 patients with chronic HCV infection before and after IFN-alpha therapy was investigated. Changes in Knodell histological activity index (HAI) scores, MT protein levels (immunohistochemistry), MT-I and MT-II messenger (m)RNA expression levels (in situ hybridization) and proliferating cell nuclear antigen (PCNA) labelling index were determined and compared in serial liver specimens. MT staining was clustered around the portal tracts with inflammatory cells and fibrosis. The pattern of MT protein before IFN-alpha therapy was similar in all patients, but was higher in IFN-sustained responders than in nonresponders after IFN-alpha therapy. HAI scores and PCNA labelling indexes were significantly reduced after IFN-alpha therapy. MT-II mRNA expression correlated positively with PCNA index before therapy and with HAI scores after therapy (P<0.05). No correlation was found between MT-I mRNA and HAI scores or PCNA index. The findings indicate that IFN-alpha-induced hepatic MT may participate in the therapeutic effects of IFN-alpha for HCV. In addition, MT-II mRNA expression may be involved in cell proliferation in the livers of patients with chronic HCV infection.

A plasmid containing the human metallothionein II gene can function as an antibody-assisted electrophoretic biosensor for heavy metals.

PubMed

Wooten, Dennis C; Starr, Clarise R; Lyon, Wanda J

2016-01-01

Different forms of heavy metals affect biochemical systems in characteristic ways that cannot be detected with typical metal analysis methods like atomic absorption spectrometry. Further, using living systems to analyze interaction of heavy metals with biochemical systems can be laborious and unreliable. To generate a reliable easy-to-use biologically-based biosensor system, the entire human metallothionein-II (MT-II) gene was incorporated into a plasmid (pUC57-MT) easily replicated in Escherichia coli. In this system, a commercial polyclonal antibody raised against human metal-responsive transcription factor-1 protein (MTF-1 protein) could modify the electrophoretic migration patterns (i.e. cause specific decreases in agarose gel electrophoretic mobility) of the plasmid in the presence or absence of heavy metals other than zinc (Zn). In the study here, heavy metals, MTF-1 protein, and polyclonal anti-MTF-1 antibody were used to assess pUC57-MT plasmid antibody-assisted electrophoretic mobility. Anti-MTF-1 antibody bound both MTF-1 protein and pUC57-MT plasmid in a non-competitive fashion such that it could be used to differentiate specific heavy metal binding. The results showed that antibody-inhibited plasmid migration was heavy metal level-dependent. Zinc caused a unique mobility shift pattern opposite to that of other metals tested, i.e. Zn blocked the antibody ability to inhibit plasmid migration, despite a greatly increased affinity for DNA by the antibody when Zn was present. The Zn effect was reversed/modified by adding MTF-1 protein. Additionally, antibody inhibition of plasmid mobility was resistant to heat pre-treatment and trypsinization, indicating absence of residual DNA extraction-resistant bacterial DNA binding proteins. DNA binding by anti-DNA antibodies may be commonly enhanced by xenobiotic heavy metals and elevated levels of Zn, thus making them potentially effective tools for assessment of heavy metal bioavailability in aqueous solutions and

Leukocyte Overexpression of Intracellular NAMPT Attenuates Atherosclerosis by Regulating PPARγ-Dependent Monocyte Differentiation and Function.

PubMed

Bermudez, Beatriz; Dahl, Tuva Borresdatter; Medina, Indira; Groeneweg, Mathijs; Holm, Sverre; Montserrat-de la Paz, Sergio; Rousch, Mat; Otten, Jeroen; Herias, Veronica; Varela, Lourdes M; Ranheim, Trine; Yndestad, Arne; Ortega-Gomez, Almudena; Abia, Rocio; Nagy, Laszlo; Aukrust, Pal; Muriana, Francisco J G; Halvorsen, Bente; Biessen, Erik Anna Leonardus

2017-06-01

Extracellular nicotinamide phosphoribosyltransferase (eNAMPT) mediates inflammatory and potentially proatherogenic effects, whereas the role of intracellular NAMPT (iNAMPT), the rate limiting enzyme in the salvage pathway of nicotinamide adenine dinucleotide (NAD) + generation, in atherogenesis is largely unknown. Here we investigated the effects of iNAMPT overexpression in leukocytes on inflammation and atherosclerosis. Low-density lipoprotein receptor-deficient mice with hematopoietic overexpression of human iNAMPT (iNAMPT hi ), on a western type diet, showed attenuated plaque burden with features of lesion stabilization. This anti-atherogenic effect was caused by improved resistance of macrophages to apoptosis by attenuated chemokine (C-C motif) receptor 2-dependent monocyte chemotaxis and by skewing macrophage polarization toward an anti-inflammatory M2 phenotype. The iNAMPT hi phenotype was almost fully reversed by treatment with the NAMPT inhibitor FK866, indicating that iNAMPT catalytic activity is instrumental in the atheroprotection. Importantly, iNAMPT overexpression did not induce any increase in eNAMPT, and eNAMPT had no effect on chemokine (C-C motif) receptor 2 expression and promoted an inflammatory M1 phenotype in macrophages. The iNAMPT-mediated effects at least partly involved sirtuin 1-dependent molecular crosstalk of NAMPT and peroxisome proliferator-activated receptor γ. Finally, iNAMPT and peroxisome proliferator-activated receptor γ showed a strong correlation in human atherosclerotic, but not healthy arteries, hinting to a relevance of iNAMPT/peroxisome proliferator-activated receptor γ pathway also in human carotid atherosclerosis. This study highlights the functional dichotomy of intracellular versus extracellular NAMPT, and unveils a critical role for the iNAMPT-peroxisome proliferator-activated receptor γ axis in atherosclerosis. © 2017 American Heart Association, Inc.

Mathematical modeling physiological effects of the overexpression of β2-adrenoceptors in mouse ventricular myocytes.

PubMed

Rozier, Kelvin; Bondarenko, Vladimir E

2018-03-01

Transgenic (TG) mice overexpressing β 2 -adrenergic receptors (β 2 -ARs) demonstrate enhanced myocardial function, which manifests in increased basal adenylyl cyclase activity, enhanced atrial contractility, and increased left ventricular function in vivo. To gain insights into the mechanisms of these effects, we developed a comprehensive mathematical model of the mouse ventricular myocyte overexpressing β 2 -ARs. We found that most of the β 2 -ARs are active in control conditions in TG mice. The simulations describe the dynamics of major signaling molecules in different subcellular compartments, increased basal adenylyl cyclase activity, modifications of action potential shape and duration, and the effects on L-type Ca 2+ current and intracellular Ca 2+ concentration ([Ca 2+ ] i ) transients upon stimulation of β 2 -ARs in control, after the application of pertussis toxin, upon stimulation with a specific β 2 -AR agonist zinterol, and upon stimulation with zinterol in the presence of pertussis toxin. The model also describes the effects of the β 2 -AR inverse agonist ICI-118,551 on adenylyl cyclase activity, action potential, and [Ca 2+ ] i transients. The simulation results were compared with experimental data obtained in ventricular myocytes from TG mice overexpressing β 2 -ARs and with simulation data on wild-type mice. In conclusion, a new comprehensive mathematical model was developed that describes multiple experimental data on TG mice overexpressing β 2 -ARs and can be used to test numerous hypotheses. As an example, using the developed model, we proved the hypothesis of the major contribution of L-type Ca 2+ current to the changes in the action potential and [Ca 2+ ] i transient upon stimulation of β 2 -ARs with zinterol. NEW & NOTEWORTHY We developed a new mathematical model for transgenic mouse ventricular myocytes overexpressing β 2 -adrenoceptors that describes the experimental findings in transgenic mice. The model reveals mechanisms of the

Calpain I Activation Causes GLUT3 Proteolysis and Downregulation of O-GlcNAcylation in Alzheimer's Disease Brain.

PubMed

Gu, Jianlan; Jin, Nana; Ma, Denglei; Chu, Dandan; Iqbal, Khalid; Gong, Cheng-Xin; Liu, Fei

2018-01-01

Impairment of cerebral glucose uptake/metabolism in individuals with Alzheimer's disease (AD) is believed to lead to downregulation of protein O-GlcNAcylation, which contributes to tau pathogenesis through tau hyperphosphorylation. Level of glucose transporter 3 (GLUT3), a neuronal specific glucose transporter, is decreased in AD brain, which may contribute to impaired brain glucose uptake/metabolism. However, what causes the reduction of GLUT3 in AD brain is not fully understood. Here, we report 1) that decrease of GLUT3 is associated with the reduction of protein O-GlcNAcylation in AD brain, 2) that GLUT3 level is negatively correlated with calpain I activation in human brain, 3) that calpain I proteolyzes GLUT3 at the N-terminus in vitro, and 4) that activation of calpain I is negatively correlated with protein O-GlcNAcylation in AD brain. Furthermore, we found that overexpression of GLUT3 enhances protein O-GlcNAcylation in N2a cells. Overexpression of calpain I suppresses protein O-GlcNAcylation in these cells. These findings suggest a novel mechanism by which calpain I overactivation leads to GLUT3 degradation and the consequent down-regulation of protein O-GlcNAcylation in AD brain.

YorkieCA overexpression in the posterior silk gland improves silk yield in Bombyx mori.

PubMed

Zhang, Panli; Liu, Shumin; Song, Hong-Sheng; Zhang, Guozheng; Jia, Qiangqiang; Li, Sheng

2017-07-01

The traditional hybrid breeding techniques can no longer meet the increasing demands for silk production by the silkworm, Bombyx mori, and further improvement of the silk yield will depend on modern molecular breeding techniques. Here, we report improved silk yield in transgenic silkworms overexpressing the oncogene Yorkie CA specifically in the posterior silk gland (PSG). The Yorkie CA cDNA was ligated downstream of the hr3 enhancer and the fibroin L-chain (Fil) promoter, then inserted into a piggyBac vector for transgene. Overexpression of Yorkie CA in the PSG significantly increased the weight of the PSG, and also increased the weight of the cocoon, larval body, and pupal body to decreasing degrees. Overexpression of Yorkie CA up-regulated the Yorkie target genes resulting in increased cell size, endomitosis, the number of protein synthesis organelles, the expression of fibroin genes in the PSG, and eventually silk yield. Additionally, as we reported previously using the binary GAL4/UAS system, transgenic silkworms overexpressing Ras1 CA with the hr3 enhancer and the Fil promoter also showed improved silk yield. Unfortunately, the hybrid progeny of Yorkie CA -overexpressing silkworms and Ras1 CA -overexpressing silkworms did not show overlapping improved silk yield due to the failure to increase expression of both Yorkie and Ras1. Copyright © 2017. Published by Elsevier Ltd.

O-GlcNAcase overexpression reverses coronary endothelial cell dysfunction in type 1 diabetic mice.

PubMed

Makino, Ayako; Dai, Anzhi; Han, Ying; Youssef, Katia D; Wang, Weihua; Donthamsetty, Reshma; Scott, Brian T; Wang, Hong; Dillmann, Wolfgang H

2015-11-01

Cardiovascular disease is the primary cause of morbidity and mortality in diabetes, and endothelial dysfunction is commonly seen in these patients. Increased O-linked N-acetylglucosamine (O-GlcNAc) protein modification is one of the central pathogenic features of diabetes. Modification of proteins by O-GlcNAc (O-GlcNAcylation) is regulated by two key enzymes: β-N-acetylglucosaminidase [O-GlcNAcase (OGA)], which catalyzes the reduction of protein O-GlcNAcylation, and O-GlcNAc transferase (OGT), which induces O-GlcNAcylation. However, it is not known whether reducing O-GlcNAcylation can improve endothelial dysfunction in diabetes. To examine the effect of endothelium-specific OGA overexpression on protein O-GlcNAcylation and coronary endothelial function in diabetic mice, we generated tetracycline-inducible, endothelium-specific OGA transgenic mice, and induced OGA by doxycycline administration in streptozotocin-induced type 1 diabetic mice. OGA protein expression was significantly decreased in mouse coronary endothelial cells (MCECs) isolated from diabetic mice compared with control MCECs, whereas OGT protein level was markedly increased. The level of protein O-GlcNAcylation was increased in diabetic compared with control mice, and OGA overexpression significantly decreased the level of protein O-GlcNAcylation in MCECs from diabetic mice. Capillary density in the left ventricle and endothelium-dependent relaxation in coronary arteries were significantly decreased in diabetes, while OGA overexpression increased capillary density to the control level and restored endothelium-dependent relaxation without changing endothelium-independent relaxation. We found that connexin 40 could be the potential target of O-GlcNAcylation that regulates the endothelial functions in diabetes. These data suggest that OGA overexpression in endothelial cells improves endothelial function and may have a beneficial effect on coronary vascular complications in diabetes. Copyright © 2015 the

Overexpression of TGF-alpha increases lung tissue hysteresivity in transgenic mice.

PubMed

Pillow, J J; Korfhagen, T R; Ikegami, M; Sly, P D

2001-12-01

Increased transforming growth factor (TGF)-alpha has been observed in neonatal chronic lung disease. Lungs of transgenic mice that overexpress TGF-alpha develop enlarged air spaces and pulmonary fibrosis compared with wild-type mice. We hypothesized that these pathological changes may alter the mechanical coupling of viscous and elastic forces within lung parenchyma. Respiratory impedance was measured in open-chested, tracheostomized adult wild-type and TGF-alpha mice by using the forced oscillation technique (0.25-19.63 Hz) delivered by flexiVent (Scireq, Montreal, PQ). Estimates of airway resistance (Raw), inertance (I), and the coefficients of tissue damping (G(L)) and tissue elastance (H(L)) were obtained by fitting a model to each impedance spectrum. Hysteresivity (eta) was calculated as G(L)/H(L). There was a significant increase in eta (P < 0.01) and a trend to a decrease in H(L) (P = 0.07) of TGF-alpha mice compared with the wild-type group. There was no significant change in Raw, I, or G(L). Structural abnormality present in the lungs of adult TGF-alpha mice alters viscoelastic coupling of the tissues, as evidenced by a change in eta.

Serum Metallothioneins in Childhood Tumours—A Potential Prognostic Marker

PubMed Central

Kruseova, Jarmila; Hynek, David; Adam, Vojtech; Kizek, Rene; Prusa, Richard; Hrabeta, Jan; Eckschlager, Tomas

2013-01-01

Metallothioneins (MT) are low molecular weight, cysteine-rich proteins maintaining metal ions homeostasis. They play a role in carcinogenesis and may also cause chemoresistance. The aim of the study was to explore the importance of MT serum levels in children suffering from malignant tumours. This prospective study involves examination of 865 samples from 172 patients with malignant tumours treated from 2008 to 2011 at University Hospital Motol. MT serum levels were determined using differential pulse voltammetry–Brdicka reaction. Mean MT level was 2.7 ± 0.5 μM. There was no statistically significant difference between MT levels in different tumours. We also did not find any correlation between MT levels and response to therapy or clinical stages. However, we found a positive correlation between MT levels and age (p = 0.009) and a negative correlation with absolute lymphocyte number (p = 0.001). The fact that patients who had early disease recurrence had lower MT levels during the treatment (complete remission 2.67 vs. recurring 2.34, p = 0.001) seems to be important for clinical practice. Accordingly we believe that there is benefit in further studies of serum MT levels in tumours. PMID:23743828

Overexpressing of OsAMT1-3, a High Affinity Ammonium Transporter Gene, Modifies Rice Growth and Carbon-Nitrogen Metabolic Status

PubMed Central

Bao, Aili; Liang, Zhijun; Zhao, Zhuqing; Cai, Hongmei

2015-01-01

AMT1-3 encodes the high affinity NH4+ transporter in rice roots and is predominantly expressed under nitrogen starvation. In order to evaluate the effect of AMT1-3 gene on rice growth, nitrogen absorption and metabolism, we generated AMT1-3-overexpressing plants and analyzed the growth phenotype, yield, carbon and nitrogen metabolic status, and gene expression profiles. Although AMT1-3 mRNA accumulated in transgenic plants, these plants displayed significant decreases in growth when compared to the wild-type plants. The nitrogen uptake assay using a 15N tracer revealed poor nitrogen uptake ability in AMT1-3-overexpressing plants. We found significant decreases in AMT1-3-overexpressing plant leaf carbon and nitrogen content accompanied with a higher leaf C/N ratio. Significant changes in soluble proteins and carbohydrates were also observed in AMT1-3-overexpressing plants. In addition, metabolite profile analysis demonstrated significant changes in individual sugars, organic acids and free amino acids. Gene expression analysis revealed distinct expression patterns of genes that participate in carbon and nitrogen metabolism. Additionally, the correlation between the metabolites and gene expression patterns was consistent in AMT1-3-overexpressing plants under both low and high nitrogen growth conditions. Therefore, we hypothesized that the carbon and nitrogen metabolic imbalance caused by AMT1-3 overexpressing attributed to the poor growth and yield of transgenic plants. PMID:25915023

Induction of metallothionein synthesis in transplanted murine tumors by X irradiation

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

Kiyoshi, Shibuya; Masahiko Satoh; Yuzo, Watanabe

1995-07-01

Although recent studies have shown that radiation can induce metallothionein (MT) synthesis in normal tissues, the induction of tumor MT synthesis by irradiation has not been reported. We examined the accumulation of MT in the Meth-A tumor (mouse fibrosarcoma cells) transplanted into mice exposed to whole-body X irradiation. In the present study, the MT content in the tumor cells was increased by X irradiation in a dose-dependent manner. The MT level induced in the tumor cells by X irradiation was elevated not only after a single exposure but also after repeated exposures. Several studies have shown that MT is onemore » of the important cellular factors in resistance to various anti-cancer drugs and ionizing radiation. Thus our results suggest that the radiation-induced MT in the tumor cells may have to be taken into consideration when designing protocols for radio-and chemotherapy. 29 refs., 3 figs.« less

Overexpression of Indian hedgehog partially rescues short stature homeobox 2-overexpression-associated congenital dysplasia of the temporomandibular joint in mice

PubMed Central

LI, XIHAI; LIANG, WENNA; YE, HONGZHI; WENG, XIAPING; LIU, FAYUAN; LIN, PINGDONG; LIU, XIANXIANG

2015-01-01

The role of short stature homeobox 2 (shox2) in the development and homeostasis of the temporomandibular joint (TMJ) has been well documented. Shox2 is known to be expressed in the progenitor cells and perichondrium of the developing condyle. A previous study by our group reported that overexpression of shox2 leads to congenital dysplasia of the TMJ via downregulation of the Indian hedgehog (Ihh) signaling pathway, which is essential for embryonic disc primordium formation and mandibular condylar growth. To determine whether overexpression of Ihh may rescue the overexpression of shox2 leading to congenital dysplasia of the TMJ, a mouse model in which Ihh and shox2 were overexpressed (Wnt1-Cre; pMes-stop shox2; pMes-stop Ihh mice) was utilized to assess the consequences of this overexpression on TMJ development during post-natal life. The results showed that the developmental process and expression levels of runt-related transcription factor 2 and sex determining region Y-box 9 in the TMJ of the Wnt1-Cre; pMes-stop shox2; pMes-stop Ihh mice were similar to those in wild-type mice. Overexpression of Ihh rescued shox2 overexpression-associated reduction of extracellular matrix components. However, overexpression of Ihh did not inhibit the shox2 overexpression-associated increase of matrix metalloproteinases (MMPs) MMP9, MMP13 and apoptosis in the TMJ. These combinatory cellular and molecular defects appeared to account for the observed congenital dysplasia of TMJ, suggesting that overexpression of Ihh partially rescued shox2 overexpression-associated congenital dysplasia of the TMJ in mice. PMID:26096903

Reduced 123I-BMIPP uptake implies decreased myocardial flow reserve in patients with chronic stable angina.

PubMed

Kageyama, Hiroyuki; Morita, Koichi; Katoh, Chietsugu; Tsukamoto, Takahiro; Noriyasu, Kazuyuki; Mabuchi, Megumi; Naya, Masanao; Kawai, Yuko; Tamaki, Nagara

2006-01-01

Long-chain fatty acid (LCFA) is the main energy source for normal myocardium at rest, but in ischemic myocardium, the main energy substrate shifts from LCFA to glucose. 123I-BMIPP is a radiolabeled LCFA analog. In chronic stable angina without previous infarction, we suppose that reduced 123I-BMIPP uptake is related to the substrate shift in myocardium with decreased myocardial flow reserve (MFR). The purpose of this study was to relate 123I-BMIPP uptake to rest myocardial blood flow (MBF), hyperemic MBF, and MFR assessed with 15O-water positron emission tomography (PET). We enrolled 21 patients with chronic stable angina without previous infarction, all of whom underwent 123I-BMIPP single-photon emission computed tomography (SPECT) and 15O-water PET. The left ventricle was divided into 13 segments. In each segment, rest MBF and hyperemic MBF were measured by PET. 123I-BMIPP uptake was evaluated as follows: score 0=normal, 1=slightly decreased uptake, 2=moderately decreased uptake, 3=severely decreased uptake, and 4=complete defect. 123I-BMIPP uptake was compared with rest MBF, hyperemic MBF, and MFR. The numbers of segments with 123I-BMIPP scores 0, 1, 2, 3, and 4 were 178, 40, 25, 24, and 0, respectively. The rest MBFs for scores 0, 1, 2, and 3 were 0.93+/-0.25, 0.86+/-0.21, 0.97+/-0.30, and 0.99+/-0.37 ml/min/g, respectively. The hyperemic MBFs for scores 0, 1, 2, and 3 were 2.76+/-1.29, 1.84+/-0.74, 1.37+/-0.39, and 1.08+/-0.40 ml/min/g, respectively. The MFRs for scores 0, 1, 2, and 3 were 3.01+/-1.38, 2.20+/-0.95, 1.44+/-0.22, and 1.10+/-0.26, respectively. As 123I-BMIPP uptake declined, hyperemic MBF and MFR decreased. In chronic stable angina without previous infarction, reduced 123I-BMIPP uptake implies decreased MFR.

Botulinum toxin decreases hyperalgesia and inhibits P2X3 receptor over-expression in sensory neurons induced by ventral root transection in rats.

PubMed

Xiao, Lizu; Cheng, Jianguo; Dai, Juanli; Zhang, Deren

2011-09-01

We aim to determine the effects of Botulinum toxin type A (BTX-A) on neuropathic pain behavior and the expression of P2X(3) receptor in dorsal root ganglion (DRG) in rats with neuropathic pain induced by L5 ventral root transection (L5 VRT). Neuropathic pain was induced by L5 VRT in male Sprague-Dawley rats. Either saline or BTX-A was administered to the plantar surface. Behavioral tests were conducted preoperatively and at predefined postoperative days. The expression of P2X(3) receptors in DRG neurons was detected by immunoreactivity at postoperative days 3, 7, 14, and 21. The number of positive P2X(3) neurons in the ipsilateral L5 DRG increased significantly after L5 VRT (P<0.001). This increase persisted for at least 3 weeks after the operation. No significant changes in P2X(3) expression were detected in the contralateral L5, or in the L4 DRGs bilaterally. Subcutaneous administration of BTX-A, performed on the left hindpaw at days 4, 8, or 16 post VRT surgery, significantly reduced mechanical allodynia bilaterally and inhibited P2X(3) over-expression induced by L5 VRT. L5 VRT led to over-expression of P2X(3) receptors in the L5 DRG and bilateral mechanical allodynia in rats. Subcutaneous injection of BTX-A significantly reversed the neuropathic pain behavior and the over-expression of P2X(3) receptor in nociceptive neurons. These data not only show over-expression of purinergic receptors in the VRT model of neuropathic pain but also reveal a novel mechanism of botulinum toxin action on nociceptive neurons. Wiley Periodicals, Inc.

Overexpression of Latent TGFβ Binding Protein 4 in Muscle Ameliorates Muscular Dystrophy through Myostatin and TGFβ

PubMed Central

Gardner, Brandon B.; Gao, Quan Q.; Hadhazy, Michele; Vo, Andy H.; Wren, Lisa; Molkentin, Jeffery D.; McNally, Elizabeth M.

2016-01-01

Latent TGFβ binding proteins (LTBPs) regulate the extracellular availability of latent TGFβ. LTBP4 was identified as a genetic modifier of muscular dystrophy in mice and humans. An in-frame insertion polymorphism in the murine Ltbp4 gene associates with partial protection against muscular dystrophy. In humans, nonsynonymous single nucleotide polymorphisms in LTBP4 associate with prolonged ambulation in Duchenne muscular dystrophy. To better understand LTBP4 and its role in modifying muscular dystrophy, we created transgenic mice overexpressing the protective murine allele of LTBP4 specifically in mature myofibers using the human skeletal actin promoter. Overexpression of LTBP4 protein was associated with increased muscle mass and proportionally increased strength compared to age-matched controls. In order to assess the effects of LTBP4 in muscular dystrophy, LTBP4 overexpressing mice were bred to mdx mice, a model of Duchenne muscular dystrophy. In this model, increased LTBP4 led to greater muscle mass with proportionally increased strength, and decreased fibrosis. The increase in muscle mass and reduction in fibrosis were similar to what occurs when myostatin, a related TGFβ family member and negative regulator of muscle mass, was deleted in mdx mice. Supporting this, we found that myostatin forms a complex with LTBP4 and that overexpression of LTBP4 led to a decrease in myostatin levels. LTBP4 also interacted with TGFβ and GDF11, a protein highly related to myostatin. These data identify LTBP4 as a multi-TGFβ family ligand binding protein with the capacity to modify muscle disease through overexpression. PMID:27148972

Overexpression of Latent TGFβ Binding Protein 4 in Muscle Ameliorates Muscular Dystrophy through Myostatin and TGFβ.

PubMed

Lamar, Kay-Marie; Bogdanovich, Sasha; Gardner, Brandon B; Gao, Quan Q; Miller, Tamari; Earley, Judy U; Hadhazy, Michele; Vo, Andy H; Wren, Lisa; Molkentin, Jeffery D; McNally, Elizabeth M

2016-05-01

Latent TGFβ binding proteins (LTBPs) regulate the extracellular availability of latent TGFβ. LTBP4 was identified as a genetic modifier of muscular dystrophy in mice and humans. An in-frame insertion polymorphism in the murine Ltbp4 gene associates with partial protection against muscular dystrophy. In humans, nonsynonymous single nucleotide polymorphisms in LTBP4 associate with prolonged ambulation in Duchenne muscular dystrophy. To better understand LTBP4 and its role in modifying muscular dystrophy, we created transgenic mice overexpressing the protective murine allele of LTBP4 specifically in mature myofibers using the human skeletal actin promoter. Overexpression of LTBP4 protein was associated with increased muscle mass and proportionally increased strength compared to age-matched controls. In order to assess the effects of LTBP4 in muscular dystrophy, LTBP4 overexpressing mice were bred to mdx mice, a model of Duchenne muscular dystrophy. In this model, increased LTBP4 led to greater muscle mass with proportionally increased strength, and decreased fibrosis. The increase in muscle mass and reduction in fibrosis were similar to what occurs when myostatin, a related TGFβ family member and negative regulator of muscle mass, was deleted in mdx mice. Supporting this, we found that myostatin forms a complex with LTBP4 and that overexpression of LTBP4 led to a decrease in myostatin levels. LTBP4 also interacted with TGFβ and GDF11, a protein highly related to myostatin. These data identify LTBP4 as a multi-TGFβ family ligand binding protein with the capacity to modify muscle disease through overexpression.

Overexpression of VMAT-2 and DT-diaphorase protects substantia nigra-derived cells against aminochrome neurotoxicity

PubMed Central

Muñoz, Patricia; Paris, Irmgard; Sanders, Laurie H.; Greenamyre, J. Timothy; Segura-Aguilar, Juan

2013-01-01

We tested the hypothesis that both VMAT-2 and DT-diaphorase are an important cellular defense against aminochrome-dependent neurotoxicity during dopamine oxidation. A cell line with VMAT-2 and DT-diaphorase over-expressed was created. The transfection of RCSN-3 cells with a bicistronic plasmid coding for VMAT-2 fused with GFP-IRES-DT-diaphorase cDNA induced a significant increase in protein expression of VMAT-2 (7-fold; P<0.001) and DT-diaphorase (9-fold; P<0.001), accompanied by a 4- and 5.5-fold significant increase in transport and enzyme activity, respectively. Studies with synaptic vesicles from rat substantia nigra revealed that VMAT-2 uptake of 3H-aminochrome 6.3 ± 0.4nmol/min/mg was similar to dopamine uptake 6.2 ± 0.3 nmol/min/mg that which were dependent on ATP. Interestingly, aminochrome uptake was inhibited by 2 μM lobeline but not reserpine (1 and 10 μM). Incubation of cells overexpressing VMAT-2 and DT-diaphorase with 20 μM aminochrome resulted in (i) a significant decrease in cell death (6-fold, P<0.001); (ii) normal ultra structure determined by transmission electron microscopy contrasting with a significant increase of autophagosome and a dramatic remodeling of the mitochondrial inner membrane in wild type cells; (iii) normal level of ATP (256 ± 11 μM) contrasting with a significant decrease in wild type cells (121 ± 11 μM, P<0.001); and (iv) a significant decrease in DNA laddering (21 ± 8 pixels, P<0.001) cells in comparison with wild type cells treated with 20 μM aminochrome (269 ± 9). These results support our hypothesis that VMAT-2 and DT-diaphorase are an important defense system against aminochrome formed during dopamine oxidation. PMID:22483869

Expression, purification of metallothionein genes from freshwater crab (Sinopotamon yangtsekiense) and development of an anti-metallothionein ELISA

PubMed Central

Zhang, Hao; Zhou, Hui

2017-01-01

Using the phoA-fusion technology, the recombinant metallothionein (MT) from freshwater crab (Sinopotamon yangtsekiense) has been successfully produced in Escherichia coli. MT purified from the bacterial suspension showed one polypeptide with a molecular weight of 7 kDa by tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis (Tricine-SDS-PAGE). Western-blotting confirmed the polypeptides had a specific reactivity with mouse polyclonal MT anti-serum. Based on the purified MT and MT anti-serum, the reaction parameters for an enzyme-linked immunosorbent assay (ELISA) were developed. The direct coating ELISA showed a higher linear relationship compared to antibody sandwich coating ELISA. The optimal dilution rates of purified MT anti-serum and coating period were shown to be 1:160,000 and 12 hours at 4°C. At 37°C, the appropriate reaction duration of the first antibody and the second antibody were 2 hours and 1 hour, respectively. According to these optimal parameters, the standard linear equation, y = 0.0032x + 0.1769 (R2 = 0.9779, x, y representing MT concentration and OD450 value), was established for the determination of MT concentration with a valid range of 3.9–500 ng/ml. In verification experiments, the mean coefficients of variation of the intra-assay and inter-assay were 3.260% and 3.736%, respectively. According to the result of MT recovery, ELISA with an approaching 100% MT recovery was more reliable and sensitive than the Cd saturation assay. In conclusion, the newly developed ELISA of this study was precise, stable and repeatable, and could be used as a biomarker tool to monitor pollution by heavy metals. PMID:28350826

A synthetic cadmium metallothionein gene (PMCd1syn) of Paramecium species: expression, purification and characteristics of metallothionein protein.

PubMed

Dar, Saira; Shuja, Rukhsana N; Shakoori, Abdul Rauf

2013-02-01

Metallothioneins (MTs) are metal binding proteins that are rich in cysteine residues constituting 10-30 % of the total protein, and in which the thiol groups bind to the metal ions. The increasing amount of metal ions in the medium have shown increased production of MTs by different organisms such as bacteria, protozoa and mammals like humans. PMCd1 is the first gene ever discovered in Paramecium, a ciliated protozoan, that could produce this MT in response to cadmium. In this study the PMCd1syn gene has been cloned in pET41a expression vector and expressed in an Escherichia coli BL21-codonplus strain for the first time. Since the gene PMCd1 amplified from Paramecium contained 10 codons, which could act as stop codons during expression in E. coli, this gene of 612 bps was synthesized to substitute these (stop) codons for the Paramecium sp. specific amino acids. For stability of the expressed protein, glutathione-S-transferase gene was fused with PMCd1syn gene and coexpressed. The cells expressing PMCd1syn demonstrated increased accumulation of cadmium. This is the first report of cadmium MT protein expressed from Paramecium species, particularly from synthetic MT gene (PMCd1syn). This fusion protein, the molecular weight of which has been confirmed to be 53.03 kDa with MALDI analysis, is rich in cysteine residues, and has been shown for the first time in this ciliate to bind to and sequester Cd(2+)-ions.

Bmi1 overexpression in the cerebellar granule cell lineage of mice affects cell proliferation and survival without initiating medulloblastoma formation

PubMed Central

Behesti, Hourinaz; Bhagat, Heeta; Dubuc, Adrian M.; Taylor, Michael D.; Marino, Silvia

2013-01-01

SUMMARY BMI1 is a potent inducer of neural stem cell self-renewal and neural progenitor cell proliferation during development and in adult tissue homeostasis. It is overexpressed in numerous human cancers – including medulloblastomas, in which its functional role is unclear. We generated transgenic mouse lines with targeted overexpression of Bmi1 in the cerebellar granule cell lineage, a cell type that has been shown to act as a cell of origin for medulloblastomas. Overexpression of Bmi1 in granule cell progenitors (GCPs) led to a decrease in cerebellar size due to decreased GCP proliferation and repression of the expression of cyclin genes, whereas Bmi1 overexpression in postmitotic granule cells improved cell survival in response to stress by altering the expression of genes in the mitochondrial cell death pathway and of Myc and Lef-1. Although no medulloblastomas developed in ageing cohorts of transgenic mice, crosses with Trp53−/− mice resulted in a low incidence of medulloblastoma formation. Furthermore, analysis of a large collection of primary human medulloblastomas revealed that tumours with a BMI1high TP53low molecular profile are significantly enriched in Group 4 human medulloblastomas. Our data suggest that different levels and timing of Bmi1 overexpression yield distinct cellular outcomes within the same cellular lineage. Importantly, Bmi1 overexpression at the GCP stage does not induce tumour formation, suggesting that BMI1 overexpression in GCP-derived human medulloblastomas probably occurs during later stages of oncogenesis and might serve to enhance tumour cell survival. PMID:23065639

Ameliorating replicative senescence of human bone marrow stromal cells by PSMB5 overexpression

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

Lu, Li, E-mail: luli7300@126.com; Song, Hui-Fang; Wei, Jiao-Long

2014-01-24

Highlights: • PSMB5 overexpression restores the differentiation potential of aged hBMSCs. • PSMB5 overexpression enhances the proteasomal activity of late-stage hBMSCs. • PSMB5 overexpression inhibits replicative senescence and improved cell viability. • PSMB5 overexpression promotes cell growth by upregulating the Cyclin D1/CDK4 complex. - Abstract: Multipotent human bone marrow stromal cells (hBMSCs) potentially serve as a source for cell-based therapy in regenerative medicine. However, in vitro expansion was inescapably accompanied with cell senescence, characterized by inhibited proliferation and compromised pluripotency. We have previously demonstrated that this aging process is closely associated with reduced 20S proteasomal activity, with down-regulation of rate-limitingmore » catalytic β-subunits particularly evident. In the present study, we confirmed that proteasomal activity directly contributes to senescence of hBMSCs, which could be reversed by overexpression of the β5-subunit (PSMB5). Knocking down PSMB5 led to decreased proteasomal activity concurrent with reduced cell proliferation in early-stage hBMSCs, which is similar to the senescent phenotype observed in late-stage cells. In contrast, overexpressing PSMB5 in late-stage cells efficiently restored the normal activity of 20S proteasomes and promoted cell growth, possibly via upregulating the Cyclin D1/CDK4 complex. Additionally, PSMB5 could enhance cell resistance to oxidative stress, as evidenced by the increased cell survival upon exposing senescent hBMSCs to hydrogen peroxide. Furthermore, PSMB5 overexpression retained the pluripotency of late-stage hBMSCs by facilitating their neural differentiation both in vitro and in vivo. Collectively, our work reveals a critical role of PSMB5 in 20S proteasome-mediated protection against replicative senescence, pointing to a possible strategy for maintaining the integrity of culture-expanded hBMSCs by manipulating the expression of PSMB5.« less

Fascin Overexpression Promotes Cholangiocarcinoma RBE Cell Proliferation, Migration, and Invasion.

PubMed

Zhao, Haiying; Yang, Fuquan; Zhao, Wenyan; Zhang, Chunjv; Liu, Jingang

2016-04-01

Fascin is overexpressed in various tumor tissues and is closely related to tumor metastasis and invasion. However, the role of fascin in cholangiocarcinoma RBE cells has not been clearly reported. This study aimed to establish a cholangiocarcinoma cell line with stable and high expression of fascin to observe the effect of fascin on cell proliferation, migration, and invasion. A fascin overexpression vector, pcDNA3.1-Fascin, was constructed and transfected into the human cholangiocarcinoma RBE cell line. The results of real-time polymerase chain reaction, Western blot, and immunofluorescence indicated that fascin was steadily and highly expressed in RBE cells. The results of 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide and colony formation assay indicated that upregulated fascin expression could enhance cholangiocarcinoma cell proliferation. The results of wound healing assay and transwell assay indicated that fascin could promote cholangiocarcinoma cell migration and invasion, and a further study found that the nuclear factor-κB signaling pathway was activated after upregulation of fascin, whereas E-cadherin expression in these cells was significantly decreased. Additionally, E-cadherin expression was significantly increased after inhibiting nuclear factor-κB activity using inhibitor or small interfering RNA, and E-cadherin expression was decreased by fascin overexpression after nuclear factor-κB inhibition, suggesting that nuclear factor-κB signaling pathway was not involved in the regulation of E-cadherin by fascin. In summary, the results of this study demonstrated that fascin effectively promoted cholangiocarcinoma RBE cell proliferation, migration, and invasion. This study provides evidence for fascin as a potential target in the treatment of cholangiocarcinoma. © The Author(s) 2015.

Differential Expression of Metallothionein Isoforms in Terrestrial Snail Embryos Reflects Early Life Stage Adaptation to Metal Stress

PubMed Central

Baurand, Pierre-Emmanuel; Pedrini-Martha, Veronika; de Vaufleury, Annette; Niederwanger, Michael; Capelli, Nicolas; Scheifler, Renaud; Dallinger, Reinhard

2015-01-01

The aim of this study was to analyze the expression of three metallothionein (MT) isoform genes (CdMT, CuMT and Cd/CuMT), already known from adults, in the Early Life Stage (ELS) of Cantareus aspersus. This was accomplished by detection of the MT isoform-specific transcription adopting Polymerase Chain Reaction (PCR) amplification and quantitative Real Time (qRT)-PCR of the three MT genes. Freshly laid eggs were kept for 24 hours under control conditions or exposed to three cadmium (Cd) solutions of increasing concentration (5, 10, and 15 mg Cd/L). The transcription of the three MT isoform genes was detected via PCR in 1, 6 and 12-day-old control or Cd-exposed embryos. Moreover, the transcription of this isoform genes during development was followed by qRT-PCR in 6 and 12-day-old embryos. Our results showed that the CdMT and Cd/CuMT genes, but not the CuMT gene, are expressed in embryos at the first day of development. The transcription of the 3 MT genes in control embryos increased with development time, suggesting that the capacities of metal regulation and detoxification may have gradually increased throughout embryogenesis. However in control embryos, the most highly expressed MT gene was that of the Cd/CuMT isoform, whose transcription levels greatly exceeded those of the other two MT genes. This contrasts with the minor significance of this gene in adult snails and suggests that in embryos, this isoform may play a comparatively more important role in metal physiology compared to adult individuals. This function in adult snails appears not to be related to Cd detoxification. Instead, snail embryos responded to Cd exposure by over-expression of the CdMT gene in a concentration-dependent manner, whereas the expression of the Cd/CuMT gene remained unaffected. Moreover, our study demonstrates the ability of snail embryos to respond very early to Cd exposure by up-regulation of the CdMT gene. PMID:25706953

Nuclear overexpression of the overexpressed in lung cancer 1 predicts worse prognosis in gastric adenocarcinoma.

PubMed

Wang, Jue; Shen, Hongchang; Fu, Guobin; Zhao, Dandan; Wang, Weibo

2017-02-07

We have performed this retrospective study to elucidate whether elevated expression of the overexpressed in lung cancer 1 (OLC1) was related to the clinicopathological parameters and prognosis of patients with gastric adenocarcinoma. Additionally, different effects of various subcellular OLC1 expression on gastric adeno-carcinogenesis were focused on in our study. Both overall and subcellular expression of OLC1 was evaluated by immunohistochemistry(IHC) via tissue microarrays from total 393 samples. The Kaplan-Meier method and Cox's proportional hazard model were exerted to further explore the correlation between OLC1 and prognosis. Total overexpression of OLC1 was significantly associated with stage (P = 0.004) and differentiation (P = 0.009), and only the strong total expression could predict a poor prognosis (HR = 1.31, P = 0.04). There were significant associations found between nuclear overexpression and tumor invasion depth(P = 0.002), lymph node (P < 0.001), stage (P = 0.004), differentiation (P < 0.001) and smoking history (P = 0.045). Furthermore, over-expressed nuclear OLC1 protein could be an independent risk factor for gastric adenocarcinoma (univariate: HR = 1.43, P = 0.003; multivariate: HR = 1.39, P = 0.011). In general, both total and nuclear overexpression of OLC1 could be the signs of gastric adeno-carcinogenesis, which might be served as the biomarkers for diagnosis at an early stage, even at the onset of tumorigenesis. Rather than the total expression, nuclear overexpression of OLC1 was correlated with most clinicopathological parameters and could predict a poor overall survival as an independent factor for prognosis, which made it a more effective and sensitive biomarker for gastric adenocarcinoma.

CYP2E1 overexpression inhibits microsomal Ca2+-ATPase activity in HepG2 cells.

PubMed

Caro, Andres A; Evans, Kerry L; Cederbaum, Arthur I

2009-01-31

Cytochrome P450 2E1 (CYP2E1) is a microsomal enzyme that generates reactive oxygen species during its catalytic cycle. We previously found an important role for calcium in CYP2E1-potentiated injury in HepG2 cells. The possibility that CYP2E1 may oxidatively damage and inactivate the microsomal Ca2+-ATPase in intact liver cells was evaluated, in order to explain why calcium is elevated during CYP2E1 toxicity. Microsomes were isolated by differential centrifugation from two liver cell line: E47 cells (HepG2 cells transfected with the pCI neo expression vector containing the human CYP2E1 cDNA, which overexpress active microsomal CYP2E1), and control C34 cells (HepG2 cells transfected with the pCI neo expression vector alone, which do not express significantly any cytochrome P450). The Ca2+-dependent ATPase activity was determined by measuring the accumulation of inorganic phosphate from ATP hydrolysis. CYP2E1 overexpression produced a 45% decrease in Ca2+-dependent ATPase activity (8.6 nmol Pi/min/mg protein in C34 microsomes versus 4.7 nmol Pi/min/mg protein in microsomes). Saturation curves with Ca2+ or ATP showed that CYP2E1 overexpression produced a decrease in Vmax but did not affect the Km for either Ca2+ or ATP. The decrease in activity was not associated with a decrease in SERCA protein levels. The ATP-dependent microsomal calcium uptake was evaluated by fluorimetry using fluo-3 as the fluorogenic probe. Calcium uptake rate in E47 microsomes was 28% lower than in C34 microsomes. Treatment of E47 cells with 2mM N-acetylcysteine prevented the decrease in microsomal Ca2+-ATPase found in E47 cells. These results suggest that CYP2E1 overexpression produces a decrease in microsomal Ca2+-ATPase activity in HepG2 cells mediated by reactive oxygen species. This may contribute to elevated cytosolic calcium and to CYP2E1-potentiated injury.

Metallothionein-3 modulates the amyloid β endocytosis of astrocytes through its effects on actin polymerization.

PubMed

Lee, Sook-Jeong; Seo, Bo-Ra; Koh, Jae-Young

2015-12-04

Astrocytes may play important roles in the pathogenesis of Alzheimer's disease (AD) by clearing extracellular amyloid beta (Aβ) through endocytosis and degradation. We recently showed that metallothionein 3 (Mt3), a zinc-binding metallothionein that is enriched in the central nervous system, contributes to actin polymerization in astrocytes. Because actin is likely involved in the endocytosis of Aβ, we investigated the possible role of Mt3 in Aβ endocytosis by cortical astrocytes in this study. To assess the route of Aβ uptake, we exposed cultured astrocytes to fluorescently labeled Aβ1-40 or Aβ1-42 together with chloropromazine (CP) or methyl-beta-cyclodextrin (MβCD), inhibitors of clathrin- and caveolin-dependent endocytosis, respectively. CP treatment almost completely blocked Aβ1-40 and Aβ1-42 endocytosis, whereas exposure to MβCD had no significant effect. Actin disruption with cytochalasin D (CytD) or latrunculin B also completely blocked Aβ1-40 and Aβ1-42 endocytosis. Because the absence of Mt3 also results in actin disruption, we examined Aβ1-40 and Aβ1-42 uptake and expression in Mt3 (-/-) astrocytes. Compared with wild-type (WT) cells, Mt3 (-/-) cells exhibited markedly reduced Aβ1-40 and Aβ1-42 endocytosis and expression of Aβ1-42 monomers and oligomers. A similar reduction was observed in CytD-treated WT cells. Finally, actin disruption and Mt3 knockout each increased the overall levels of clathrin and the associated protein phosphatidylinositol-binding clathrin assembly protein (PICALM) in astrocytes. Our results suggest that the absence of Mt3 reduces Aβ uptake in astrocytes through an abnormality in actin polymerization. In light of evidence that Mt3 is downregulated in AD, our findings indicate that this mechanism may contribute to the extracellular accumulation of Aβ in this disease.

Dimethylarginine Dimethylaminohydrolase Overexpression enhances Insulin Sensitivity

PubMed Central

Sydow, Karsten; Mondon, Carl E.; Schrader, Joerg; Konishi, Hakuoh; Cooke, John P.

2011-01-01

Objective Previous studies suggest that nitric oxide (NO) may modulate insulin-induced uptake of glucose in insulin-sensitive tissues. Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of NO synthase (NOS). We hypothesized that a reduction in endogenous ADMA would increase NO synthesis and thereby enhance insulin sensitivity. Methods and Results To test this hypothesis we employed a transgenic mouse in which we overexpressed human dimethylarginine dimethylaminohydrolase (DDAH-I). The DDAH-I mice had lower plasma ADMA at all ages (22–70 weeks) by comparison to wild-type (WT) littermates. With a glucose challenge, WT mice showed a prompt increase in ADMA, whereas DDAH-I mice had a blunted response. Furthermore, DDAH-I mice had a blunted increase in plasma insulin and glucose levels after glucose challenge, with a 50% reduction in the insulin resistence index, consistent with enhanced sensitivity to insulin. In liver, we observed an increased Akt phosphorylation in the DDAH-I mice after i.p. glucose challenge. Incubation of skeletal muscle from WT mice ex vivo with ADMA (2μM) markedly suppressed insulin-induced glycogen synthesis in fast-twitch but not slow-twitch muscle. Conclusions These findings suggest that the endogenous NOS inhibitor ADMA reduces insulin sensitivity, consistent with previous observations that NO plays a role in insulin sensitivity. PMID:18239148

Targeted overexpression of mitochondrial catalase prevents radiation-induced cognitive dysfunction.

PubMed

Parihar, Vipan K; Allen, Barrett D; Tran, Katherine K; Chmielewski, Nicole N; Craver, Brianna M; Martirosian, Vahan; Morganti, Josh M; Rosi, Susanna; Vlkolinsky, Roman; Acharya, Munjal M; Nelson, Gregory A; Allen, Antiño R; Limoli, Charles L

2015-01-01

Radiation-induced disruption of mitochondrial function can elevate oxidative stress and contribute to the metabolic perturbations believed to compromise the functionality of the central nervous system. To clarify the role of mitochondrial oxidative stress in mediating the adverse effects of radiation in the brain, we analyzed transgenic (mitochondrial catalase [MCAT]) mice that overexpress human catalase localized to the mitochondria. Compared with wild-type (WT) controls, overexpression of the MCAT transgene significantly decreased cognitive dysfunction after proton irradiation. Significant improvements in behavioral performance found on novel object recognition and object recognition in place tasks were associated with a preservation of neuronal morphology. While the architecture of hippocampal CA1 neurons was significantly compromised in irradiated WT mice, the same neurons in MCAT mice did not exhibit extensive and significant radiation-induced reductions in dendritic complexity. Irradiated neurons from MCAT mice maintained dendritic branching and length compared with WT mice. Protected neuronal morphology in irradiated MCAT mice was also associated with a stabilization of radiation-induced variations in long-term potentiation. Stabilized synaptic activity in MCAT mice coincided with an altered composition of the synaptic AMPA receptor subunits GluR1/2. Our findings provide the first evidence that neurocognitive sequelae associated with radiation exposure can be reduced by overexpression of MCAT, operating through a mechanism involving the preservation of neuronal morphology. Our article documents the neuroprotective properties of reducing mitochondrial reactive oxygen species through the targeted overexpression of catalase and how this ameliorates the adverse effects of proton irradiation in the brain.

GPX2 overexpression indicates poor prognosis in patients with hepatocellular carcinoma.

PubMed

Liu, Ting; Kan, Xue-Feng; Ma, Charlie; Chen, Li-Li; Cheng, Tian-Tian; Zou, Zhen-Wei; Li, Yong; Cao, Feng-Jun; Zhang, Wen-Jie; Yao, Jing; Li, Pin-Dong

2017-06-01

Glutathione peroxidase 2 has important role of tumor progression in lots of carcinomas, yet little is known about the prognosis of glutathione peroxidase 2 in hepatocellular carcinoma. Glutathione peroxidase 2 expression was assessed by immunohistochemistry in hepatocellular carcinoma tissues. The association between glutathione peroxidase 2 expression with clinicopathological/prognostic value was examined. Glutathione peroxidase 2 overexpression was correlated with alpha-fetoprotein level, larger tumor, BCLC stage, and tumor recurrence. Kaplan-Meier analysis showed that glutathione peroxidase 2 was an independent predictor for overall survival and time to recurrence. glutathione peroxidase 2 overexpression was correlated with poor prognosis in patient subgroups stratified by tumor size, differentiation, tumor-node-metastasis, and BCLC stage. Moreover, stratified analysis showed that tumor-node-metastasis stage-I patients with high glutathione peroxidase 2 expression had poor prognosis than those with low glutathione peroxidase 2 expression. Additionally, combination of glutathione peroxidase 2 and serum alpha-fetoprotein was correlated with prognosis in hepatocellular carcinoma. In conclusion, glutathione peroxidase 2 overexpression contributes to poor prognosis of hepatocellular carcinoma patients and helps to identify the high-risk hepatocellular carcinoma patients.

Skeletal Muscle-Specific Overexpression of PGC-1α Induces Fiber-Type Conversion through Enhanced Mitochondrial Respiration and Fatty Acid Oxidation in Mice and Pigs.

PubMed

Zhang, Lin; Zhou, Ying; Wu, Wangjun; Hou, Liming; Chen, Hongxing; Zuo, Bo; Xiong, Yuanzhu; Yang, Jinzeng

2017-01-01

Individual skeletal muscles in the animal body are heterogeneous, as each is comprised of different fiber types. Type I muscle fibers are rich with mitochondria, and have high oxidative metabolisms while type IIB fibers have few mitochondria and high glycolytic metabolic capacity. Peroxisome proliferator-activated receptor gamma coactivator 1α (PGC-1α), a transcriptional co-activator that regulates mitochondrial biogenesis and respiratory function, is implicated in muscle fiber-type switching. Over-expression of PGC-1α in transgenic mice increased the proportion of red/oxidative type I fiber. During pig muscle growth, an increased number of type I fibers can give meat more red color. To explore the roles of PGC-1α in regulation of muscle fiber type conversion, we generated skeletal muscle-specific PGC-1α transgenic mice and pig. Ectopic over-expression of PGC-1α was detected in both fast and slow muscle fibers. The transgenic animals displayed a remarkable amount of red/oxidative muscle fibers in major skeletal muscle tissues. Skeletal muscles from transgenic mice and pigs have increased expression levels of oxidative fiber markers such as MHC1, MHC2x, myoglobin and Tnni1, and decreased expressions of glycolytic fiber genes (MHC2a, MHC2b, CASQ-1 and Tnni2). The genes responsible for the TCA cycle and oxidative phosphorylation, cytochrome coxidase 2 and 4, and citrate synthase were also increased in the transgenic mice and pigs. These results suggested that transgenic over-expressed PGC-1α significantly increased muscle mitochondrial biogenesis, resulting in qualitative changes from glycolytic to oxidative energy generation. The transgenic animals also had elevated levels of PDK4 and PPARγ proteins in muscle tissue, which can lead to increased glycogen deposition and fatty acid oxidation. Therefore, the results support a significant role of PGC-1α in conversion of fast glycolytic fibers to slow and oxidative fiber through enhanced mitochondrial respiration

Induction of Metallothionein Expression After Exposure to Conventional Cigarette Smoke but Not Electronic Cigarette (ECIG)-Generated Aerosol in Caenorhabditis elegans

PubMed Central

Cobb, Eric; Hall, Julie; Palazzolo, Dominic L.

2018-01-01

Aim: With the invention of electronic cigarettes (ECIG), many questions have been raised regarding their safety as an alternative to smoking conventional cigarettes. Conventional cigarette smoke contains a variety of toxicants including heavy metals. However, ECIG-generated aerosol contains only trace amounts of metals, adding to the argument for it being a safer alternative. In response to heavy metal exposure, metallothioneins are induced in cells to help store the metal, detoxify the body, and are also known responders to oxidative stress. In an attempt to add to the evaluation of the safety of ECIGs, metallothionein expression was quantified using the nematode Caenorhabditis elegans as an assessment of stress induced cellular damage caused by exposure. Methods: Adult nematodes were exposed to either ECIG aerosol or conventional cigarette smoke at doses of 15, 30, and 45 puffs, the equivalent of one, two, and three cigarettes, respectively. Movement, survival, and stress-induced sleep were assessed for up to 24 h after exposure. Relative expression levels for mtl-1 and mtl-2, C. elegans metallothionein genes, were analyzed after 1, 5, and 24 h post exposure using quantitative RT-PCR. Results: Nematodes exposed to conventional cigarette smoke underwent stress-induced sleep in a dose dependent manner with animals recovering to values within the range of air control after 5 h post exposure. Those exposed to ECIG aerosol did not undergo stress-induced sleep and were indistinguishable from controls. The expression of mtl-1 increased in a dose and time dependent manner in C. elegans exposed to conventional cigarette smoke, with a maximum expression observed at 5 h post exposure of 45 puffs. No induction of mtl-2 was observed in any animals. Additionally, ECIG aerosol did not induce expression of mtl-1 and mtl-2 at levels different than those of untreated. Conclusion: ECIG aerosol failed to induce a stress response in C. elegans. In contrast, conventional cigarette

Glucose Limitation Alters Glutamine Metabolism in MUC1-Overexpressing Pancreatic Cancer Cells.

PubMed

Gebregiworgis, Teklab; Purohit, Vinee; Shukla, Surendra K; Tadros, Saber; Chaika, Nina V; Abrego, Jaime; Mulder, Scott E; Gunda, Venugopal; Singh, Pankaj K; Powers, Robert

2017-10-06

Pancreatic cancer cells overexpressing Mucin 1 (MUC1) rely on aerobic glycolysis and, correspondingly, are dependent on glucose for survival. Our NMR metabolomics comparative analysis of control (S2-013.Neo) and MUC1-overexpressing (S2-013.MUC1) cells demonstrates that MUC1 reprograms glutamine metabolism upon glucose limitation. The observed alteration in glutamine metabolism under glucose limitation was accompanied by a relative decrease in the proliferation of MUC1-overexpressing cells compared with steady-state conditions. Moreover, glucose limitation induces G1 phase arrest where S2-013.MUC1 cells fail to enter S phase and synthesize DNA because of a significant disruption in pyrimidine nucleotide biosynthesis. Our metabolomics analysis indicates that glutamine is the major source of oxaloacetate in S2-013.Neo and S2-013.MUC1 cells, where oxaloacetate is converted to aspartate, an important metabolite for pyrimidine nucleotide biosynthesis. However, glucose limitation impedes the flow of glutamine carbons into the pyrimidine nucleotide rings and instead leads to a significant accumulation of glutamine-derived aspartate in S2-013.MUC1 cells.

[Overexpression of LaeA enhances mevastatin production and reduces sporulation of Penicillium citrinum].

PubMed

Zheng, Yueliang; Cao, Shuang; Huang, Yuqi; Liao, Guojian; Hu, Changhua

2014-12-04

To study the regulation of laeA overexpression on mevastatin production and sporulation in Penicillium citrinum. We cloned the laeA gene from Penicillium citrinum and constructed the vector pGiHTGi-laeA. The plasmid pGiHTGi-laeA was transformed in Penicillium citrinum by agrobacterium tumefaciens-mediated transformation. Positive transformants were detected by cloning the hygromycin gene. The mevastatin production of the wild type and OE:: laeA was compared by HPLC. The conidia number was counted by blood counting chamber. The biosynthetic gene cluster expression quantity of mevastatin in the wild type and OE: :laeA were analyzed by qRT-PCR. We constructed the plasmid pGiHTGi-laeA, and screened the positive transformants that overexpress the laeA in Penicillium citrinum. With the overexpression of laeA, the mevastatin production was increased from (0.69 ± 0.12) mg/g to (4.02 ± 0.50) mg/g dry cell weight. Compared to the wild type strain, the laeA expression quantity in the OE :: laeA strain increased 29%, and the mlcB expression increased 72%, the mlcR expression increased 153%. Moreover, the overexpression of laeA would decrease the conidia number. Overexpression of LaeA enhances mevastatin production and reduces sporulation of Penicillium citrinum, with increases expression of pathway-regulator mlcR, and biosynthetic gene MlcR. These results could guide global regulatory mechanism of mevastatin biosynthesis and the exploitation of high-production strain.

Heterologous expression of a rice metallothionein isoform (OsMTI-1b) in Saccharomyces cerevisiae enhances cadmium, hydrogen peroxide and ethanol tolerance.

PubMed

Ansarypour, Zahra; Shahpiri, Azar

Metallothioneins are a superfamily of low-molecular-weight, cysteine (Cys)-rich proteins that are believed to play important roles in protection against metal toxicity and oxidative stress. The main purpose of this study was to investigate the effect of heterologous expression of a rice metallothionein isoform (OsMTI-1b) on the tolerance of Saccharomyces cerevisiae to Cd 2+ , H 2 O 2 and ethanol stress. The gene encoding OsMTI-1b was cloned into p426GPD as a yeast expression vector. The new construct was transformed to competent cells of S. cerevisiae. After verification of heterologous expression of OsMTI-1b, the new strain and control were grown under stress conditions. In comparison to control strain, the transformed S. cerevisiae cells expressing OsMTI-1b showed more tolerance to Cd 2+ and accumulated more Cd 2+ ions when they were grown in the medium containing CdCl 2 . In addition, the heterologous expression of GST-OsMTI-1b conferred H 2 O 2 and ethanol tolerance to S. cerevisiae cells. The results indicate that heterologous expression of plant MT isoforms can enhance the tolerance of S. cerevisiae to multiple stresses. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Preservation of Intestinal Structural Integrity by Zinc Is Independent of Metallothionein in Alcohol-Intoxicated Mice

PubMed Central

Lambert, Jason C.; Zhou, Zhanxiang; Wang, Lipeng; Song, Zhenyuan; McClain, Craig J.; Kang, Y. James

2004-01-01

Intestinal-derived endotoxins are importantly involved in alcohol-induced liver injury. Disruption of intestinal barrier function and endotoxemia are common features associated with liver inflammation and injury due to acute ethanol exposure. Zinc has been shown to inhibit acute alcohol-induced liver injury. This study was designed to determine the inhibitory effect of zinc on alcohol-induced endotoxemia and whether the inhibition is mediated by metallothionein (MT) or is independent of MT. MT knockout (MT-KO) mice were administered three oral doses of zinc sulfate (2.5 mg zinc ion/kg body weight) every 12 hours before being administered a single dose of ethanol (6 g/kg body weight) by gavage. Ethanol administration caused liver injury as determined by increased serum transaminases, parenchymal fat accumulation, necrotic foci, and an elevation of tumor necrosis factor (TNF-α). Increased plasma endotoxin levels were detected in ethanol-treated animals whose small intestinal structural integrity was compromised as determined by microscopic examination. Zinc supplementation significantly inhibited acute ethanol-induced liver injury and suppressed hepatic TNF-α production in association with decreased circulating endotoxin levels and a significant protection of small intestine structure. As expected, MT levels remained undetectable in the MT-KO mice under the zinc treatment. These results thus demonstrate that zinc preservation of intestinal structural integrity is associated with suppression of endotoxemia and liver injury induced by acute exposure to ethanol and the zinc protection is independent of MT. PMID:15161632

Reducing diacetyl production of wine by overexpressing BDH1 and BDH2 in Saccharomyces uvarum.

PubMed

Li, Ping; Guo, Xuewu; Shi, Tingting; Hu, Zhihui; Chen, Yefu; Du, Liping; Xiao, Dongguang

2017-11-01

As a byproduct of yeast valine metabolism during fermentation, diacetyl can produce a buttery aroma in wine. However, high diacetyl concentrations generate an aromatic off-flavor and poor quality in wine. 2,3-Butanediol dehydrogenase encoded by BDH1 can catalyze the two reactions of acetoin from diacetyl and 2,3-butanediol from acetoin. BDH2 is a gene adjacent to BDH1, and these genes are regulated reciprocally. In this study, BDH1 and BDH2 were overexpressed in Saccharomyces uvarum to reduce the diacetyl production of wine either individually or in combination. Compared with those in the host strain WY1, the diacetyl concentrations in the recombinant strains WY1-1 with overexpressed BDH1, WY1-2 with overexpressed BDH2 alone, and WY1-12 with co-overexpressed BDH1 and BDH2 were decreased by 39.87, 33.42, and 46.71%, respectively. BDH2 was only responsible for converting diacetyl into acetoin, but not for the metabolic pathway of acetoin to 2,3-butanediol in S. uvarum. This study provided valuable insights into diacetyl reduction in wine.

VEGF Receptor-2 (Flk-1) Overexpression in Mice Counteracts Focal Epileptic Seizures

PubMed Central

Nikitidou, Litsa; Kanter-Schlifke, Irene; Dhondt, Joke; Carmeliet, Peter; Lambrechts, Diether; Kokaia, Mérab

2012-01-01

Vascular endothelial growth factor (VEGF) was first described as an angiogenic agent, but has recently also been shown to exert various neurotrophic and neuroprotective effects in the nervous system. These effects of VEGF are mainly mediated by its receptor, VEGFR-2, which is also referred to as the fetal liver kinase receptor 1 (Flk-1). VEGF is up-regulated in neurons and glial cells after epileptic seizures and counteracts seizure-induced neurodegeneration. In vitro, VEGF administration suppresses ictal and interictal epileptiform activity caused by AP4 and 0 Mg2+ via Flk-1 receptor. We therefore explored whether increased VEGF signaling through Flk-1 overexpression may regulate epileptogenesis and ictogenesis in vivo. To this extent, we used transgenic mice overexpressing Flk-1 postnatally in neurons. Intriguingly, Flk-1 overexpressing mice were characterized by an elevated threshold for seizure induction and a decreased duration of focal afterdischarges, indicating anti-ictal action. On the other hand, the kindling progression in these mice was similar to wild-type controls. No significant effects on blood vessels or glia cells, as assessed by Glut1 and GFAP immunohistochemistry, were detected. These results suggest that increased VEGF signaling via overexpression of Flk-1 receptors may directly affect seizure activity even without altering angiogenesis. Thus, Flk-1 could be considered as a novel target for developing future gene therapy strategies against ictal epileptic activity. PMID:22808185

Disturbed alternative splicing of FIR (PUF60) directed cyclin E overexpression in esophageal cancers.

PubMed

Ogura, Yukiko; Hoshino, Tyuji; Tanaka, Nobuko; Ailiken, Guzhanuer; Kobayashi, Sohei; Kitamura, Kouichi; Rahmutulla, Bahityar; Kano, Masayuki; Murakami, Kentarou; Akutsu, Yasunori; Nomura, Fumio; Itoga, Sakae; Matsubara, Hisahiro; Matsushita, Kazuyuki

2018-05-01

Overexpression of alternative splicing of far upstream element binding protein 1 (FUBP1) interacting repressor (FIR; poly(U) binding splicing factor 60 [PUF60]) and cyclin E were detected in esophageal squamous cell carcinomas (ESCC). Accordingly, the expression of FBW7 was examined by which cyclin E is degraded as a substrate via the proteasome system. Expectedly, FBW7 expression was decreased significantly in ESCC. Conversely, c-myc gene transcriptional repressor FIR (alias PUF60; U2AF-related protein) and its alternative splicing variant form (FIRΔexon2) were overexpressed in ESCC. Further, anticancer drugs (cis-diaminedichloroplatinum/cisplatin [CDDP] or 5-fluorouracil [5-FU]) and knockdown of FIR by small interfering RNA (siRNA) increased cyclin E while knockdown of FIRΔexon2 by siRNA decreased cyclin E expression in ESCC cell lines (TE1, TE2, and T.Tn) or cervical SCC cells (HeLa cells). Especially, knockdown of SAP155 (SF3b1), a splicing factor required for proper alternative splicing of FIR pre-mRNA, decreased cyclin E. Therefore, disturbed alternative splicing of FIR generated FIR/FIRΔexon2 with cyclin E overexpression in esophageal cancers, indicating that SAP155 siRNA potentially rescued FBW7 function by reducing expression of FIR and/or FIRΔexon2. Remarkably, Three-dimensional structure analysis revealed the hypothetical inhibitory mechanism of FBW7 function by FIR/FIRΔexon2, a novel mechanism of cyclin E overexpression by FIR/FIRΔexon2-FBW7 interaction was discussed. Clinically, elevated FIR expression potentially is an indicator of the number of lymph metastases and anti-FIR/FIRΔexon2 antibodies in sera as cancer diagnosis, indicating chemical inhibitors of FIR/FIRΔexon2-FBW7 interaction could be potential candidate drugs for cancer therapy. In conclusion, elevated cyclin E expression was, in part, induced owing to potential FIR/FIRΔexon2-FBW7 interaction in ESCC.

Overexpression of Tobacco GCN2 Stimulates Multiple Physiological Changes Associated With Stress Tolerance

PubMed Central

Li, Ning; Zhang, Song-jie; Zhao, Qi; Long, Yue; Guo, Hao; Jia, Hong-fang; Yang, Yong-xia; Zhang, Hong-ying; Ye, Xie-feng; Zhang, Song-tao

2018-01-01

General control non-derepressible-2 (GCN2) is a ubiquitous protein kinase that phosphorylates the α subunit of the eukaryotic initiation factor, eIF2, preventing the initiation of a new cycle of protein synthesis, subsequently reducing the global protein biosynthesis. GCN2 can also regulate the response of plants to biotic and abiotic stresses. In this study, two GCN2 homologs, NtGCN2-1 and NtGCN2-2, were cloned from Nicotiana tabacum, and were predicted to have been derived from their progenitors in N. tomentosiformis and N. sylvestris, respectively. The phosphorylation of NteIF2α could be activated by promoting the expression of NtGCN2 with plant hormones, including salicylic acid (SA), azelaic acid (AZA), methyl jasmonate (MeJA), and by imposition of different stresses (Bemisia tabaci infection, drought, and cold), indicating that NtGCN2 is involved in the response of plants to multiple biotic and abiotic stresses. We also observed that the overexpression of NtGCN2-1 significantly influenced different physiological processes. It promoted seed germination and root elongation. The content of total soluble sugars and reducing sugars were decreased, whereas those of chlorophyll a and b were increased in the GCN2 overexpressing plants. In addition, the overexpressing plants had lower content of reactive oxygen species and exhibited higher antioxidant activities. These physiological alterations could be attributed to the changes in the endogenous phytohormones, decrease in the SA and abscisic acid content, and accumulation of MeJA and AZA. It indicated that the overexpression of NtGCN2 in tobacco, stimulated the plant defense responses via phosphorylation of NteIF2α and regulation of plant hormones, and changes in the antioxidant ability and plant nutrient status. PMID:29910821

Absence of Metallothionein 3 Expression in Breast Cancer is a Rare, But Favorable Marker of Outcome that is Under Epigenetic Control

PubMed Central

Somji, Seema; Garrett, Scott H.; Zhou, Xu Dong; Zheng, Yun; Sens, Donald A.; Sens, Mary Ann

2010-01-01

Cadmium (Cd+2), a known carcinogen mimics the effects of estrogen in the uterus and mammary gland suggesting its possible involvement in the development and progression of breast cancer. This lab showed through analysis of a small set of archival human diagnostic specimens that the third isoform of the classic Cd+2 binding protein metallothionein (MT-3), is not expressed in normal breast tissue, but is expressed in some breast cancers and that expression tends to correlate with a poor disease outcome. The goals of the present study were to verify that overexpression of MT-3 in a large set of archival human diagnostic specimens tends to correlate with poor disease outcome and define the mechanism of MT-3 gene regulation in the normal breast epithelial cell. The results showed that MT-3 was expressed in approximately 90% of all breast cancers and was absent in normal breast epithelium. The lack of MT-3 staining in some cancers correlated with a favorable patient outcome. High frequency of MT-3 staining was also found for in situ breast cancer suggesting that MT-3 might be an early biomarker for breast cancer. The study also demonstrated that the MCF-10A cell line, an immortalized, non-tumorigenic model of human breast epithelial cells, displayed no basal expression of MT-3, nor was it induced by Cd+2. Treatment of the MCF-10A cells with the demethylation agent, 5-Aza-2′-deoxycytidine, or the histone deacetylase inhibitor, MS-275, restored MT-3 mRNA expression. It was also shown that the MT-3 metal regulatory elements are potentially active binders of protein factors following treatment with these inhibitors suggesting that MT-3 expression may be subject to epigenetic regulation. PMID:21170156

LncRNA CCAT2 promotes tumorigenesis by over-expressed Pokemon in non-small cell lung cancer.

PubMed

Zhao, Zhihong; Wang, Ju; Wang, Shengfa; Chang, Hao; Zhang, Tiewa; Qu, Junfeng

2017-03-01

Non-small cell lung cancer (NSCLC) remains one of the most important death-related diseases, with poor effective diagnosis and less therapeutic biomarkers. LncRNA colon cancer-associated transcript 2 (CCAT2) was identified as an oncogenic lncRNA and over-expressed in many tumor cells. The aims of this study were to detect the correlation between CCAT2 and its regulatory genes and then explore the potential mechanism between them in NSCLC. In this study, qRT-PCR was used to detect CCAT2, Pokemon and p21 expression. Western-blot was used to detect protein levels of Pokemon and p21. CCK-8 assay and Transwell chambers were used to assess cell viability and invasion. CCAT2 and Pokemon were over-expressed in NSCLC tissue and cells. In NSCLC cells, CCAT2 knockdown significantly decreased cell viability and invasion as well as Pokemon expression, but increased the expression of p21; then CCAT2 overexpression revealed an opposite result. In addition, over-expressed Pokemon reversed the results that induced by si-CCAT2, while down-regulation of Pokemon significantly reversed the results that induced by CCAT2 overexpression. The results indicated that CCAT2 promotes tumorigenesis by over-expression of Pokemon, and the potential mechanism might relate to the Pokemon related gene p21. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Metallothionein turnover in mammalian cell lines: implications in drug resistance

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

Monia, B.P.; Butt, T.R.; Ecker, D.J.

1986-05-01

Metallothioneins (MT) are low molecular weight, cysteine-rich proteins believed to participate in metal detoxification. A wide variety of cells in culture have been shown to accumulate MT in response to metal administration. These metal-induced increases in MT levels result from an increased rate of MT gene transcription, MT mRNA accumulation, and MT synthesis. Turnover of Cd-, Zn- and Au-induced MT was studied in a Chinese Hamster Ovary (CHO) cell line which was resistant to Cd and the Au-containing drug Auranofin (AF). Cd, Zn and Au were potent inducers of MT mRNA and accumulated approximately equal amounts of mRNA under themore » conditions employed in this study. Pulse-chase studies utilizing (/sup 35/S)cysteine revealed that the half-life of Au-, Zn- and Cd-induced MT was 0.75, 10 and 24 hrs. respectively. The reported differences in the tertiary structure of Au-MT from that of Cd-MT lead us to propose that the differences in half-lives observed reflect differences in subceptibility to intracellular proteolysis, which in turn, may effect the ability of MT to confer resistance to various metals.« less

Disrupting CCT-β : β-tubulin selectively kills CCT-β overexpressed cancer cells through MAPKs activation

PubMed Central

Liu, Yan-Jin; Kumar, Vathan; Lin, Yuan-Feng; Liang, Po-Huang

2017-01-01

We have previously demonstrated the ability of I-Trp to disrupt the protein–protein interaction of β-tubulin with chaperonin-containing TCP-1β (CCT-β). This caused more severe apoptosis in multidrug-resistant MES-SA/Dx5, compared to MES-SA, due to its higher CCT-β overexpression. In this study, we screened a panel of cancer cell lines, finding CCT-β overexpression in the triple-negative breast cancer cell line MDA-MB-231, colorectal cancer cell lines Colo205 and HCT116, and a gastric cancer cell line MKN-45. Thus, I-Trp killed these cancers with sub- to low-μM EC50, whereas it was non-toxic to MCF-10A. We then synthesized analogs of I-Trp and evaluated their cytotoxicity. Furthermore, apoptotic mechanism investigations revealed the activation of both protein ubiquitination/degradation and ER-associated protein degradation pathways. These pathways proceeded through activation of MAPKs at the onset of CCT-β : β-tubulin complex disruption. We thus establish an effective strategy to treat CCT-β overexpressed cancers by disrupting the CCT-β : β-tubulin complex. PMID:28906489

Overexpression of Catalase in Vascular Smooth Muscle Cells Prevents the Formation of Abdominal Aortic Aneurysms

PubMed Central

Parastatidis, Ioannis; Weiss, Daiana; Joseph, Giji; Taylor, W Robert

2013-01-01

Objective Elevated levels of oxidative stress have been reported in abdominal aortic aneurysms (AAA), but which reactive oxygen species (ROS) promotes the development of AAA remains unclear. Here we investigate the effect of the hydrogen peroxide (H2O2) degrading enzyme catalase on the formation of AAA. Approach and Results AAA were induced with the application of calcium chloride (CaCl2) on mouse infrarenal aortas. The administration of PEG-catalase, but not saline, attenuated the loss of tunica media and protected against AAA formation (0.91±0.1 mm vs. 0.76±0.09 mm). Similarly, in a transgenic mouse model, catalase over-expression in the vascular smooth muscle cells (VSMC) preserved the thickness of tunica media and inhibited aortic dilatation by 50% (0.85±0.14 mm vs. 0.57±0.08 mm). Further studies showed that injury with CaCl2 decreased catalase expression and activity in the aortic wall. Pharmacologic administration or genetic over-expression of catalase restored catalase activity and subsequently decreased matrix metalloproteinase activity. In addition, a profound reduction in inflammatory markers and VSMC apoptosis was evident in aortas of catalase over-expressing mice. Interestingly, as opposed to infusion of PEG-catalase, chronic over-expression of catalase in VSMC did not alter the total aortic H2O2 levels. Conclusions The data suggest that a reduction in aortic wall catalase activity can predispose to AAA formation. Restoration of catalase activity in the vascular wall enhances aortic VSMC survival and prevents AAA formation primarily through modulation of matrix metalloproteinase activity. PMID:23950141

Overexpression of bone sialoprotein leads to an uncoupling of bone formation and bone resorption in mice.

PubMed

Valverde, Paloma; Zhang, Jin; Fix, Amanda; Zhu, Ji; Ma, Wenli; Tu, Qisheng; Chen, Jake

2008-11-01

The purpose of this study was to determine the effects of bone sialoprotein (BSP) overexpression in bone metabolism in vivo by using a homozygous transgenic mouse line that constitutively overexpresses mouse BSP cDNA driven by the cytomegalovirus (CMV) promoter. CMV-BSP transgenic (TG) mice and wildtype mice were weighed, and their length, BMD, and trabecular bone volume were measured. Serum levels of RANKL, osteocalcin, osteoprotegerin (OPG), TRACP5b, and PTH were determined. Bone histomorphometry, von Kossa staining, RT-PCR analysis, Western blot, MTS assay, in vitro mineralization assay, and TRACP staining were also performed to delineate phenotypes of this transgenic mouse line. Compared with wildtype mice, adult TG mice exhibit mild dwarfism, lower values of BMD, and lower trabecular bone volume. TG mice serum contained increased calcium levels and decreased PTH levels, whereas the levels of phosphorus and magnesium were within normal limits. TG mice serum also exhibited lower levels of osteoblast differentiation markers and higher levels of markers, indicating osteoclastic activity and bone resorption. H&E staining, TRACP staining, and bone histomorphometry showed that adult TG bones were thinner and the number of giant osteoclasts in TG mice was higher, whereas there were no significant alterations in osteoblast numbers between TG mice and WT mice. Furthermore, the vertical length of the hypertrophic zone in TG mice was slightly enlarged. Moreover, ex vivo experiments indicated that overexpression of BSP decreased osteoblast population and increased osteoclastic activity. Partly because of its effects in enhancing osteoclastic activity and decreasing osteoblast population, BSP overexpression leads to an uncoupling of bone formation and resorption, which in turn results in osteopenia and mild dwarfism in mice. These findings are expected to help the development of therapies to metabolic bone diseases characterized by high serum level of BSP.

Overexpression of Bone Sialoprotein Leads to an Uncoupling of Bone Formation and Bone Resorption in Mice

PubMed Central

Valverde, Paloma; Zhang, Jin; Fix, Amanda; Zhu, Ji; Ma, Wenli; Tu, Qisheng; Chen, Jake

2008-01-01

The purpose of this study was to determine the effects of bone sialoprotein (BSP) overexpression in bone metabolism in vivo by using a homozygous transgenic mouse line that constitutively overexpresses mouse BSP cDNA driven by the cytomegalovirus (CMV) promoter. CMV-BSP transgenic (TG) mice and wildtype mice were weighed, and their length, BMD, and trabecular bone volume were measured. Serum levels of RANKL, osteocalcin, osteoprotegerin (OPG), TRACP5b, and PTH were determined. Bone histomorphometry, von Kossa staining, RT-PCR analysis, Western blot, MTS assay, in vitro mineralization assay, and TRACP staining were also performed to delineate phenotypes of this transgenic mouse line. Compared with wildtype mice, adult TG mice exhibit mild dwarfism, lower values of BMD, and lower trabecular bone volume. TG mice serum contained increased calcium levels and decreased PTH levels, whereas the levels of phosphorus and magnesium were within normal limits. TG mice serum also exhibited lower levels of osteoblast differentiation markers and higher levels of markers, indicating osteoclastic activity and bone resorption. H&E staining, TRACP staining, and bone histomorphometry showed that adult TG bones were thinner and the number of giant osteoclasts in TG mice was higher, whereas there were no significant alterations in osteoblast numbers between TG mice and WT mice. Furthermore, the vertical length of the hypertrophic zone in TG mice was slightly enlarged. Moreover, ex vivo experiments indicated that overexpression of BSP decreased osteoblast population and increased osteoclastic activity. Partly because of its effects in enhancing osteoclastic activity and decreasing osteoblast population, BSP overexpression leads to an uncoupling of bone formation and resorption, which in turn results in osteopenia and mild dwarfism in mice. These findings are expected to help the development of therapies to metabolic bone diseases characterized by high serum level of BSP. PMID:18597627

Overexpression of Arabidopsis thaliana brassinosteroid-related acyltransferase 1 gene induces brassinosteroid-deficient phenotypes in creeping bentgrass

PubMed Central

Han, Yun-Jeong; Kim, Young Soon; Hwang, Ok-Jin; Roh, Jeehee; Ganguly, Keya; Kim, Seong-Ki; Hwang, Ildoo

2017-01-01

Brassinosteroids (BRs) are naturally occurring steroidal hormones that play diverse roles in various processes during plant growth and development. Thus, genetic manipulation of endogenous BR levels might offer a way of improving the agronomic traits of crops, including plant architecture and stress tolerance. In this study, we produced transgenic creeping bentgrass (Agrostis stolonifera L.) overexpressing a BR-inactivating enzyme, Arabidopsis thaliana BR-related acyltransferase 1 (AtBAT1), which is known to catalyze the conversion of BR intermediates to inactive acylated conjugates. After putative transgenic plants were selected using herbicide resistance assay, genomic integration of the AtBAT1 gene was confirmed by genomic PCR and Southern blot analysis, and transgene expression was validated by northern blot analysis. The transgenic creeping bentgrass plants exhibited BR-deficient phenotypes, including reduced plant height with shortened internodes (i.e., semi-dwarf), reduced leaf growth rates with short, wide, and thick architecture, high chlorophyll contents, decreased numbers of vascular bundles, and large lamina joint bending angles (i.e., erect leaves). Subsequent analyses showed that the transgenic plants had significantly reduced amounts of endogenous BR intermediates, including typhasterol, 6-deoxocastasterone, and castasterone. Moreover, the AtBAT1 transgenic plants displayed drought tolerance as well as delayed senescence. Therefore, the results of the present study demonstrate that overexpression of an Arabidopsis BR-inactivating enzyme can reduce the endogenous levels of BRs in creeping bentgrass resulting in BR-deficient phenotypes, indicating that the AtBAT1 gene from a dicot plant is also functional in the monocot crop. PMID:29084267

Decreased RECQL5 correlated with disease progression of osteosarcoma

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

Wu, Junlong; Zhi, Liqiang; Dai, Xin

Human RecQ helicase family, consisting of RECQL, RECQL4, RECQL5, BLM and WRN, has critical roles in genetic stability and tumorigenesis. Although RECQL5 has been reported to correlate with the susceptibility to malignances including osteosarcoma, the specific effect on tumor genesis and progression is not yet clarified. Here we focused on the relationship between RECQL5 expression and osteosarcoma disease progression, and further investigated the function of RECQL5 on MG-63 cell proliferation and apoptosis. By immunohistochemical analysis, qRT-PCR and western blot, we found that RECQL5 expression was downregulated in osteosarcoma tissues and cells. Patients with advanced tumor stage and low grade expressedmore » lower RECQL5. To construct a stable RECQL5 overexpression osteosarcoma cell line (MG-63-RECQL5), RECQL5 gene was inserted into the human AAVS1 safe harbor by CRISPR/Cas9 system. The overexpression of RECQL5 was verified by qRT-PCR and western blot. Cell proliferation, cell cycle and apoptosis assay revealed that RECQL5 overexpression inhibited proliferation, induced G1-phase arrest and promoted apoptosis in MG-63 cells. Collectively, our results suggested RECQL5 as a tumor suppressor in osteosarcoma and may be a potential therapeutic target for osteosarcoma treatment. - Highlights: • The expression of RECQL5 was downregulated in osteosarcoma tissues and cells. • Decreased RECQL5 correlated with osteosarcoma Enneking surgical classification. • We constructed a stable RECQL5 overexpression cell line by CRISPR/Cas9 system. • RECQL5 overexpression inhibited proliferation of MG-63 cells. • RECQL5 overexpression promoted apoptosis of MG-63 cells.« less

L-Endoglin Overexpression Increases Renal Fibrosis after Unilateral Ureteral Obstruction

PubMed Central

Arévalo, Miguel; Núñez-Gómez, Elena; Pérez-Roque, Lucía; Pericacho, Miguel; González-Núñez, María; Langa, Carmen; Martínez-Salgado, Carlos; Perez-Barriocanal, Fernando; Bernabeu, Carmelo; Lopez-Novoa, José M.

2014-01-01

Transforming growth factor-β (TGF-β) plays a pivotal role in renal fibrosis. Endoglin, a 180 KDa membrane glycoprotein, is a TGF-β co-receptor overexpressed in several models of chronic kidney disease, but its function in renal fibrosis remains uncertain. Two membrane isoforms generated by alternative splicing have been described, L-Endoglin (long) and S-Endoglin (short) that differ from each other in their cytoplasmic tails, being L-Endoglin the most abundant isoform. The aim of this study was to assess the effect of L-Endoglin overexpression in renal tubulo-interstitial fibrosis. For this purpose, a transgenic mouse which ubiquitously overexpresses human L-Endoglin (L-ENG+) was generated and unilateral ureteral obstruction (UUO) was performed in L-ENG+ mice and their wild type (WT) littermates. Obstructed kidneys from L-ENG+ mice showed higher amounts of type I collagen and fibronectin but similar levels of α-smooth muscle actin (α-SMA) than obstructed kidneys from WT mice. Smad1 and Smad3 phosphorylation were significantly higher in obstructed kidneys from L-ENG+ than in WT mice. Our results suggest that the higher increase of renal fibrosis observed in L-ENG+ mice is not due to a major abundance of myofibroblasts, as similar levels of α-SMA were observed in both L-ENG+ and WT mice, but to the higher collagen and fibronectin synthesis by these fibroblasts. Furthermore, in vivo L-Endoglin overexpression potentiates Smad1 and Smad3 pathways and this effect is associated with higher renal fibrosis development. PMID:25313562

Targeted Overexpression of Mitochondrial Catalase Prevents Radiation-Induced Cognitive Dysfunction

PubMed Central

Parihar, Vipan K.; Allen, Barrett D.; Tran, Katherine K.; Chmielewski, Nicole N.; Craver, Brianna M.; Martirosian, Vahan; Morganti, Josh M.; Rosi, Susanna; Vlkolinsky, Roman; Acharya, Munjal M.; Nelson, Gregory A.; Allen, Antiño R.

2015-01-01

Abstract Aims: Radiation-induced disruption of mitochondrial function can elevate oxidative stress and contribute to the metabolic perturbations believed to compromise the functionality of the central nervous system. To clarify the role of mitochondrial oxidative stress in mediating the adverse effects of radiation in the brain, we analyzed transgenic (mitochondrial catalase [MCAT]) mice that overexpress human catalase localized to the mitochondria. Results: Compared with wild-type (WT) controls, overexpression of the MCAT transgene significantly decreased cognitive dysfunction after proton irradiation. Significant improvements in behavioral performance found on novel object recognition and object recognition in place tasks were associated with a preservation of neuronal morphology. While the architecture of hippocampal CA1 neurons was significantly compromised in irradiated WT mice, the same neurons in MCAT mice did not exhibit extensive and significant radiation-induced reductions in dendritic complexity. Irradiated neurons from MCAT mice maintained dendritic branching and length compared with WT mice. Protected neuronal morphology in irradiated MCAT mice was also associated with a stabilization of radiation-induced variations in long-term potentiation. Stabilized synaptic activity in MCAT mice coincided with an altered composition of the synaptic AMPA receptor subunits GluR1/2. Innovation: Our findings provide the first evidence that neurocognitive sequelae associated with radiation exposure can be reduced by overexpression of MCAT, operating through a mechanism involving the preservation of neuronal morphology. Conclusion: Our article documents the neuroprotective properties of reducing mitochondrial reactive oxygen species through the targeted overexpression of catalase and how this ameliorates the adverse effects of proton irradiation in the brain. Antioxid. Redox Signal. 22, 78–91. PMID:24949841

Overexpression of SIRT1 in Mouse Forebrain Impairs Lipid/Glucose Metabolism and Motor Function

PubMed Central

Wu, Dongmei; Qiu, Yifu; Gao, Xiang; Yuan, Xiao-Bing; Zhai, Qiwei

2011-01-01

SIRT1 plays crucial roles in glucose and lipid metabolism, and has various functions in different tissues including brain. The brain-specific SIRT1 knockout mice display defects in somatotropic signaling, memory and synaptic plasticity. And the female mice without SIRT1 in POMC neuron are more sensitive to diet-induced obesity. Here we created transgenic mice overexpressing SIRT1 in striatum and hippocampus under the control of CaMKIIα promoter. These mice, especially females, exhibited increased fat accumulation accompanied by significant upregulation of adipogenic genes in white adipose tissue. Glucose tolerance of the mice was also impaired with decreased Glut4 mRNA levels in muscle. Moreover, the SIRT1 overexpressing mice showed decreased energy expenditure, and concomitantly mitochondria-related genes were decreased in muscle. In addition, these mice showed unusual spontaneous physical activity pattern, decreased activity in open field and rotarod performance. Further studies demonstrated that SIRT1 deacetylated IRS-2, and upregulated phosphorylation level of IRS-2 and ERK1/2 in striatum. Meanwhile, the neurotransmitter signaling in striatum and the expression of endocrine hormones in hypothalamus and serum T3, T4 levels were altered. Taken together, our findings demonstrate that SIRT1 in forebrain regulates lipid/glucose metabolism and motor function. PMID:21738790

Overexpression of Mafb in Podocytes Protects against Diabetic Nephropathy

PubMed Central

Yoh, Keigyou; Ojima, Masami; Okamura, Midori; Nakamura, Megumi; Hamada, Michito; Shimohata, Homare; Moriguchi, Takashi; Yamagata, Kunihiro; Takahashi, Satoru

2014-01-01

We previously showed that the transcription factor Mafb is essential for podocyte differentiation and foot process formation. Podocytes are susceptible to injury in diabetes, and this injury leads to progression of diabetic nephropathy. In this study, we generated transgenic mice that overexpress Mafb in podocytes using the nephrin promoter/enhancer. To examine a potential pathogenetic role for Mafb in diabetic nephropathy, Mafb transgenic mice were treated with either streptozotocin or saline solution. Diabetic nephropathy was assessed by renal histology and biochemical analyses of urine and serum. Podocyte-specific overexpression of Mafb had no effect on body weight or blood glucose levels in either diabetic or control mice. Notably, albuminuria and changes in BUN levels and renal histology observed in diabetic wild-type animals were ameliorated in diabetic Mafb transgenic mice. Moreover, hyperglycemia-induced downregulation of Nephrin was mitigated in diabetic Mafb transgenic mice, and reporter assay results suggested that Mafb regulates Nephrin directly. Mafb transgenic glomeruli also overexpressed glutathione peroxidase, an antioxidative stress enzyme, and levels of the oxidative stress marker 8-hydroxydeoxyguanosine decreased in the urine of diabetic Mafb transgenic mice. Finally, Notch2 expression increased in diabetic glomeruli, and this effect was enhanced in diabetic Mafb transgenic glomeruli. These data indicate Mafb has a protective role in diabetic nephropathy through regulation of slit diaphragm proteins, antioxidative enzymes, and Notch pathways in podocytes and suggest that Mafb could be a therapeutic target. PMID:24722438

Overexpression of Mafb in podocytes protects against diabetic nephropathy.

PubMed

Morito, Naoki; Yoh, Keigyou; Ojima, Masami; Okamura, Midori; Nakamura, Megumi; Hamada, Michito; Shimohata, Homare; Moriguchi, Takashi; Yamagata, Kunihiro; Takahashi, Satoru

2014-11-01

We previously showed that the transcription factor Mafb is essential for podocyte differentiation and foot process formation. Podocytes are susceptible to injury in diabetes, and this injury leads to progression of diabetic nephropathy. In this study, we generated transgenic mice that overexpress Mafb in podocytes using the nephrin promoter/enhancer. To examine a potential pathogenetic role for Mafb in diabetic nephropathy, Mafb transgenic mice were treated with either streptozotocin or saline solution. Diabetic nephropathy was assessed by renal histology and biochemical analyses of urine and serum. Podocyte-specific overexpression of Mafb had no effect on body weight or blood glucose levels in either diabetic or control mice. Notably, albuminuria and changes in BUN levels and renal histology observed in diabetic wild-type animals were ameliorated in diabetic Mafb transgenic mice. Moreover, hyperglycemia-induced downregulation of Nephrin was mitigated in diabetic Mafb transgenic mice, and reporter assay results suggested that Mafb regulates Nephrin directly. Mafb transgenic glomeruli also overexpressed glutathione peroxidase, an antioxidative stress enzyme, and levels of the oxidative stress marker 8-hydroxydeoxyguanosine decreased in the urine of diabetic Mafb transgenic mice. Finally, Notch2 expression increased in diabetic glomeruli, and this effect was enhanced in diabetic Mafb transgenic glomeruli. These data indicate Mafb has a protective role in diabetic nephropathy through regulation of slit diaphragm proteins, antioxidative enzymes, and Notch pathways in podocytes and suggest that Mafb could be a therapeutic target. Copyright © 2014 by the American Society of Nephrology.

Neuron-specific caveolin-1 overexpression improves motor function and preserves memory in mice subjected to brain trauma.

PubMed

Egawa, Junji; Schilling, Jan M; Cui, Weihua; Posadas, Edmund; Sawada, Atsushi; Alas, Basheer; Zemljic-Harpf, Alice E; Fannon-Pavlich, McKenzie J; Mandyam, Chitra D; Roth, David M; Patel, Hemal H; Patel, Piyush M; Head, Brian P

2017-08-01

Studies in vitro and in vivo demonstrate that membrane/lipid rafts and caveolin (Cav) organize progrowth receptors, and, when overexpressed specifically in neurons, Cav-1 augments neuronal signaling and growth and improves cognitive function in adult and aged mice; however, whether neuronal Cav-1 overexpression can preserve motor and cognitive function in the brain trauma setting is unknown. Here, we generated a neuron-targeted Cav-1-overexpressing transgenic (Tg) mouse [synapsin-driven Cav-1 (SynCav1 Tg)] and subjected it to a controlled cortical impact model of brain trauma and measured biochemical, anatomic, and behavioral changes. SynCav1 Tg mice exhibited increased hippocampal expression of Cav-1 and membrane/lipid raft localization of postsynaptic density protein 95, NMDA receptor, and tropomyosin receptor kinase B. When subjected to a controlled cortical impact, SynCav1 Tg mice demonstrated preserved hippocampus-dependent fear learning and memory, improved motor function recovery, and decreased brain lesion volume compared with wild-type controls. Neuron-targeted overexpression of Cav-1 in the adult brain prevents hippocampus-dependent learning and memory deficits, restores motor function after brain trauma, and decreases brain lesion size induced by trauma. Our findings demonstrate that neuron-targeted Cav-1 can be used as a novel therapeutic strategy to restore brain function and prevent trauma-associated maladaptive plasticity.-Egawa, J., Schilling, J. M., Cui, W., Posadas, E., Sawada, A., Alas, B., Zemljic-Harpf, A. E., Fannon-Pavlich, M. J., Mandyam, C. D., Roth, D. M., Patel, H. H., Patel, P. M., Head, B. P. Neuron-specific caveolin-1 overexpression improves motor function and preserves memory in mice subjected to brain trauma. © FASEB.

Inhibition of CDK-mediated phosphorylation of Smad3 results in decreased oncogenesis in triple negative breast cancer cells

PubMed Central

Tarasewicz, Elizabeth; Rivas, Lisbi; Hamdan, Randala; Dokic, Danijela; Parimi, Vamsi; Bernabe, Beatriz Penalver; Thomas, Alexandra; Shea, Lonnie D; Jeruss, Jacqueline S

2014-01-01

Breast cancer onset and disease progression have been linked to members of the TGFβ superfamily and their downstream signaling components, the Smads. Alterations in Smad3 signaling are associated with the dichotomous role of TGFβ in malignancy, mediating both tumor suppressant and pro-metastatic behaviors. Overexpression of cell cycle regulators, cyclins D and E, renders cyclin-dependent kinases (CDKs) 4/2 hyperactive. Noncanonical phosphorylation of Smad3 by CDK4/2 inhibits tumor suppressant actions of Smad3. We hypothesized that CDK inhibition (CDKi) would restore Smad3 action and help promote cancer cell regression. Treatment of triple-negative breast cancer (TNBC) cell lines (MDA-MB-231, MDA-MB-436, Hs578T) with CDK2i or CDK4i resulted in increased Smad3 activity and decreased cell migration. Transfection with a 5M Smad3 construct containing inhibitory mutations in 5 CDK phosphorylation sites also resulted in decreased TNBC cell migration and invasion. MDA-MB-231 cells treated with CDK2i or CDK4i resulted in decreased Smad3 protein phosphorylation at the CDK phosphorylation T179 site, decreased MMP2 and c-myc expression, and increased p15 and p21 expression. Using a novel transfected cell array, we found that CDK2i treatment decreased activity of the epithelial-to-mesenchymal transition related transcription factors Snail and Twist. In vivo studies in an MDA-MB-231 tumor model showed that individual and combination treatment with paclitaxel and CDK2i resulted in decreased tumor volume and Ki67 staining. Collectively, these data support further investigation of targeted CDK inhibitors as a promising therapeutic strategy for TNBC, a breast cancer subtype with limited treatment options. PMID:25485498

Overexpression of S-adenosylmethionine decarboxylase (SAMDC) in early Xenopus embryos induces cell dissociation and inhibits transition from the blastula to gastrula stage.

PubMed

Shibata, M; Shinga, J; Yasuhiko, Y; Kai, M; Miura, K; Shimogori, T; Kashiwagi, K; Igarashi, K; Shiokawa, K

1998-07-01

Xenopus early embryos contain relatively low levels of S-adenosyl-methionine decarboxylase (SAMDC) and its mRNA. When SAMDC mRNA was injected into Xenopus embryos, it was preserved until the blastula stage and induced a large increase in SAMDC activity. The SAMDC-overexpressed embryos developed normally until the blastula stage but at the early gastrula stage cells which received the mRNA, dissociated autonomously and stopped synthesizing protein. In a hypotonic medium, the dissociated cells, and hence whole embryos, autolyzed. However, in isotonic media dissociated cells did not autolyze, although they did not divide and their DNA and RNA synthesis activity was greatly inhibited. The effects of SAMDC overexpression were abolished by coinjection of ethylglyoxal-bis(guanylhydrazone) (EGBG), a specific inhibitor of SAMDC. In SAMDC-overexpressed embryos the level of putrescine decreased and that of spermidine increased, though to limited extents, resulting in a considerable decrease in the putrescine/spermidine ratio. However, direct injection of spermidine did not mimic the effect of SAMDC overexpression, and putrescine coinjected with SAMDC mRNA to maintain the normal putrescine/spermidine ratio did not rescue the embryos. Conversely, the level of S-adenosylmethionine (SAM) greatly decreased and coinjection of SAM, which restored the level of SAM, rescued the embryos. We concluded that in SAMDC-overexpressed embryos a SAM-deficient state was induced and this caused cell dissociation and inhibition of transition from the blastula to gastrula stage. We suggest that the SAM-deficient embryos obtained in the present study provide a unique system for studying the cellular control mechanism underlying the blastula-gastrula transition.

Hepatic NPC1L1 overexpression ameliorates glucose metabolism in diabetic mice via suppression of gluconeogenesis.

PubMed

Kurano, Makoto; Hara, Masumi; Satoh, Hiroaki; Tsukamoto, Kazuhisa

2015-05-01

Inhibition of intestinal NPC1L1 by ezetimibe has been demonstrated to improve glucose metabolism in rodent models; however, the role of hepatic NPC1L1 in glucose metabolism has not been elucidated. In this study, we analyzed the effects of hepatic NPC1L1 on glucose metabolism. We overexpressed NPC1L1 in the livers of lean wild type mice, diet-induced obesity mice and db/db mice with adenoviral gene transfer. We found that in all three mouse models, hepatic NPC1L1 overexpression lowered fasting blood glucose levels as well as blood glucose levels on ad libitum; in db/db mice, hepatic NPC1L1 overexpression improved blood glucose levels to almost the same as those found in lean wild type mice. A pyruvate tolerance test revealed that gluconeogenesis was suppressed by hepatic NPC1L1 overexpression. Further analyses revealed that hepatic NPC1L1 overexpression decreased the expression of FoxO1, resulting in the reduced expression of G6Pase and PEPCK, key enzymes in gluconeogenesis. These results indicate that hepatic NPC1L1 might have distinct properties of suppressing gluconeogenesis via inhibition of FoxO1 pathways. Copyright © 2015 Elsevier Inc. All rights reserved.

SPARC Overexpression Inhibits Cell Proliferation in Neuroblastoma and Is Partly Mediated by Tumor Suppressor Protein PTEN and AKT

PubMed Central

Bhoopathi, Praveen; Gorantla, Bharathi; Sailaja, G. S.; Gondi, Christopher S.; Gujrati, Meena; Klopfenstein, Jeffrey D.; Rao, Jasti S.

2012-01-01

Secreted protein acidic and rich in cysteine (SPARC) is also known as BM-40 or Osteonectin, a multi-functional protein modulating cell–cell and cell–matrix interactions. In cancer, SPARC is not only linked with a highly aggressive phenotype, but it also acts as a tumor suppressor. In the present study, we sought to characterize the function of SPARC and its role in sensitizing neuroblastoma cells to radio-therapy. SPARC overexpression in neuroblastoma cells inhibited cell proliferation in vitro. Additionally, SPARC overexpression significantly suppressed the activity of AKT and this suppression was accompanied by an increase in the tumor suppressor protein PTEN both in vitro and in vivo. Restoration of neuroblastoma cell radio-sensitivity was achieved by overexpression of SPARC in neuroblastoma cells in vitro and in vivo. To confirm the role of the AKT in proliferation inhibited by SPARC overexpression, we transfected neuroblastoma cells with a plasmid vector carrying myr-AKT. Myr-AKT overexpression reversed SPARC-mediated PTEN and increased proliferation of neuroblastoma cells in vitro. PTEN overexpression in parallel with SPARC siRNA resulted in decreased AKT phosphorylation and proliferation in vitro. Taken together, these results establish SPARC as an effector of AKT-PTEN-mediated inhibition of proliferation in neuroblastoma in vitro and in vivo. PMID:22567126

Epigenetic regulation of NFE2 overexpression in myeloproliferative neoplasms.

PubMed

Peeken, Jan C; Jutzi, Jonas S; Wehrle, Julius; Koellerer, Christoph; Staehle, Hans F; Becker, Heiko; Schoenwandt, Elias; Seeger, Thalia S; Schanne, Daniel H; Gothwal, Monika; Ott, Christopher J; Gründer, Albert; Pahl, Heike L

2018-05-03

The transcription factor "nuclear factor erythroid 2" (NFE2) is overexpressed in the majority of patients with myeloproliferative neoplasms (MPNs). In murine models, elevated NFE2 levels cause an MPN phenotype with spontaneous leukemic transformation. However, both the molecular mechanisms leading to NFE2 overexpression and its downstream targets remain incompletely understood. Here, we show that the histone demethylase JMJD1C constitutes a novel NFE2 target gene. JMJD1C levels are significantly elevated in polycythemia vera (PV) and primary myelofibrosis patients; concomitantly, global H3K9me1 and H3K9me2 levels are significantly decreased. JMJD1C binding to the NFE2 promoter is increased in PV patients, decreasing both H3K9me2 levels and binding of the repressive heterochromatin protein-1α (HP1α). Hence, JMJD1C and NFE2 participate in a novel autoregulatory loop. Depleting JMJD1C expression significantly reduced cytokine-independent growth of an MPN cell line. Independently, NFE2 is regulated through the epigenetic JAK2 pathway by phosphorylation of H3Y41. This likewise inhibits HP1α binding. Treatment with decitabine lowered H3Y41ph and augmented H3K9me2 levels at the NFE2 locus in HEL cells, thereby increasing HP1α binding, which normalized NFE2 expression selectively in JAK2 V617F -positive cell lines. © 2018 by The American Society of Hematology.

Overexpression of Hif-1α in Mesenchymal Stem Cells Affects Cell-Autonomous Angiogenic and Osteogenic Parameters.

PubMed

Lampert, F M; Kütscher, C; Stark, G B; Finkenzeller, G

2016-03-01

Reconstruction of large bone defects still represents a major medical challenge. In recent years tissue engineering has developed techniques based on adult mesenchymal stem cells (MSCs) that could represent an attractive therapeutical option to treat large bone defects in the future. It has been demonstrated in various animal models that ex vivo expanded MSCs are capable of promoting the regeneration of skeletal defects after implantation. However, for the efficient regeneration of bone in tissue engineering applications, a rapid vascularization of implanted grafts is essential to ensure the survival of cells in the early post-implantational phase. A promising strategy to enhance vascularization of MSC-containing implants could consist of overexpression of the angiogenic master transcription factor Hypoxia-inducible factor 1 (Hif-1) in the MSCs in order to induce angiogenesis and support osteogenesis. In the present study, we overexpressed Hif-1α in MSCs by using recombinant adenoviruses and investigated cell-autonomous effects. Overexpression of Hif-1α enhanced proliferation, migration, cell survival and expression of pro-angiogenic genes. Other parameters such as expression of the osteogenic markers BMP-2 and RunX2 were decreased. Hif-1α overexpression had no effect on invasion, senescence and osteogenic differentiation of MSCs. Our experiments revealed multifarious effects of Hif-1α overexpression on cell-autonomous parameters. Therefore, Hif-1α overexpression may represent a therapeutic option to improve cellular functions of MSCs to treat critical sized bone defects. © 2015 Wiley Periodicals, Inc.

Overexpression of p53 mRNA in colorectal cancer and its relationship to p53 gene mutation.

PubMed Central

el-Mahdani, N.; Vaillant, J. C.; Guiguet, M.; Prévot, S.; Bertrand, V.; Bernard, C.; Parc, R.; Béréziat, G.; Hermelin, B.

1997-01-01

We analysed the frequency of p53 mRNA overexpression in a series of 109 primary colorectal carcinomas and its association with p53 gene mutation, which has been correlated with short survival. Sixty-nine of the 109 cases (63%) demonstrated p53 mRNA overexpression, without any correlation with stage or site of disease. Comparison with p53 gene mutation indicated that, besides cases in which p53 gene mutation and p53 mRNA overexpression were either both present (40 cases) or both absent (36 cases), there were also cases in which p53 mRNA was overexpressed in the absence of any mutation (29 cases) and those with a mutant gene in which the mRNA was not overexpressed (four cases). Moreover, the mutant p53 tumours exhibited an increase of p53 mRNA expression, which was significantly higher in tumours expressing the mutated allele alone than in tumours expressing both wild- and mutated-type alleles. These data (1) show that p53 mRNA overexpression is a frequent event in colorectal tumours and is not predictive of the status of the gene, i.e. whether or not a mutation is present; (2) provide further evidence that p53 protein overexpression does not only result from an increase in the half-life of mutated p53 and suggest that inactivation of the p53 function in colorectal cancers involves at least two distinct mechanisms, including p53 overexpression and/or mutation; and (3) suggest that p53 mRNA overexpression is an early event, since it is not correlated with Dukes stage. PMID:9052405

Overexpression of hypoxia-inducible factor-1 alpha improves vasculogenesis-related functions of endothelial progenitor cells.

PubMed

Kütscher, Christian; Lampert, Florian M; Kunze, Mirjam; Markfeld-Erol, Filiz; Stark, G Björn; Finkenzeller, Günter

2016-05-01

Postnatal vasculogenesis is mediated by mobilization of endothelial progenitor cells (EPCs) from bone marrow and homing to ischemic tissues. This feature emphasizes this cell type for cell-based therapies aiming at the improvement of neovascularization in tissue engineering applications and regenerative medicine. In animal models, it was demonstrated that implantation of EPCs from cord blood (cbEPCs) led to the formation of a complex functional neovasculature, whereas EPCs isolated from adult peripheral blood (pbEPCs) showed a limited vasculogenic potential, which may be attributed to age-related dysfunction. Recently, it was demonstrated that activation of hypoxia-inducible factor-1α (Hif-1α) improves cell functions of progenitor cells of mesenchymal and endothelial origin. Thus, we hypothesized that overexpression of Hif-1α may improve the vasculogenesis-related phenotype of pbEPCs. In the present study, we overexpressed Hif-1α in pbEPCs and cbEPCs by using recombinant adenoviruses and investigated effects on stem cell- and vasculogenesis-related cell parameters. Overexpression of Hif-1α enhanced proliferation, invasion, cell survival and in vitro capillary sprout formation of both EPC populations. Migration was increased in cbEPCs upon Hif-1α overexpression, but not in pbEPCs. Cellular senescence was decreased in pbEPCs, while remained in cbEPCs, which showed, as expected, intrinsically a dramatically lower senescent phenotype in relation to pbEPCs. Similarly, the colony-formation capacity was much higher in cbEPCs in comparison to pbEPCs and was further increased by Hif-1α overexpression, whereas Hif-1α transduction exerted no significant influence on colony formation of pbEPCs. In summary, our experiments illustrated multifarious effects of Hif-1α overexpression on stem cell and vasculogenic parameters. Therefore, Hif-1α overexpression may represent a therapeutic option to improve cellular functions of adult as well as postnatal EPCs. Copyright �

Clinical trial to evaluate safety and immunogenicity of an oral inactivated enterotoxigenic Escherichia coli prototype vaccine containing CFA/I overexpressing bacteria and recombinantly produced LTB/CTB hybrid protein.

PubMed

Lundgren, A; Leach, S; Tobias, J; Carlin, N; Gustafsson, B; Jertborn, M; Bourgeois, L; Walker, R; Holmgren, J; Svennerholm, A-M

2013-02-06

We have developed a new oral vaccine against enterotoxigenic Escherichia coli (ETEC) diarrhea containing killed recombinant E. coli bacteria expressing increased levels of ETEC colonization factors (CFs) and a recombinant protein (LCTBA), i.e. a hybrid between the binding subunits of E. coli heat labile toxin (LTB) and cholera toxin (CTB). We describe a randomized, comparator controlled, double-blind phase I trial in 60 adult Swedish volunteers of a prototype of this vaccine. The safety and immunogenicity of the prototype vaccine, containing LCTBA and an E. coli strain overexpressing the colonization factor CFA/I, was compared to a previously developed oral ETEC vaccine, consisting of CTB and inactivated wild type ETEC bacteria expressing CFA/I (reference vaccine). Groups of volunteers were given two oral doses of either the prototype or the reference vaccine; the prototype vaccine was administered at the same or a fourfold higher dosage than the reference vaccine. The prototype vaccine was found to be safe and equally well-tolerated as the reference vaccine at either dosage tested. The prototype vaccine induced mucosal IgA (fecal secretory IgA and intestine-derived IgA antibody secreting cell) responses to both LTB and CFA/I, as well as serum IgA and IgG antibody responses to LTB. Immunization with LCTBA resulted in about twofold higher mucosal and systemic IgA responses against LTB than a comparable dose of CTB. The higher dose of the prototype vaccine induced significantly higher fecal and systemic IgA responses to LTB and fecal IgA responses to CFA/I than the reference vaccine. These results demonstrate that CF over-expression and inclusion of the LCTBA hybrid protein in an oral inactivated ETEC vaccine does not change the safety profile when compared to a previous generation of such a vaccine and that the prototype vaccine induces significant dose dependent mucosal immune responses against CFA/I and LTB. Copyright © 2013 Elsevier Ltd. All rights reserved.

Generation of Osteosarcomas from a Combination of Rb Silencing and c‐Myc Overexpression in Human Mesenchymal Stem Cells

PubMed Central

Wang, Jir‐You; Wu, Po‐Kuei; Chen, Paul Chih‐Hsueh; Lee, Chia‐Wen

2016-01-01

Abstract Osteosarcoma (OS) was a malignant tumor occurring with unknown etiology that made prevention and early diagnosis difficult. Mesenchymal stem cells (MSCs), which were found in bone marrow, were claimed to be a possible origin of OS but with little direct evidence. We aimed to characterize OS cells transformed from human MSCs (hMSCs) and identify their association with human primary OS cells and patient survival. Genetic modification with p53 or retinoblastoma (Rb) knockdown and c‐Myc or Ras overexpression was applied for hMSC transformation. Transformed cells were assayed for proliferation, differentiation, tumorigenecity, and gene expression profile. Only the combination of Rb knockdown and c‐Myc overexpression successfully transformed hMSCs derived from four individual donors, with increasing cell proliferation, decreasing cell senescence rate, and increasing ability to form colonies and spheres in serum‐free medium. These transformed cells lost the expression of certain surface markers, increased in osteogenic potential, and decreased in adipogenic potential. After injection in immunodeficient mice, these cells formed OS‐like tumors, as evidenced by radiographic analyses and immunohistochemistry of various OS markers. Microarray with cluster analysis revealed that these transformed cells have gene profiles more similar to patient‐derived primary OS cells than their normal MSC counterparts. Most importantly, comparison of OS patient tumor samples revealed that a combination of Rb loss and c‐Myc overexpression correlated with a decrease in patient survival. This study successfully transformed human MSCs to OS‐like cells by Rb knockdown and c‐Myc overexpression that may be a useful platform for further investigation of preventive and target therapy for human OS. Stem Cells Translational Medicine 2017;6:512–526 PMID:28191765

Light Intensity-Dependent Modulation of Chlorophyll b Biosynthesis and Photosynthesis by Overexpression of Chlorophyllide a Oxygenase in Tobacco1[C][OA

PubMed Central

Biswal, Ajaya K.; Pattanayak, Gopal K.; Pandey, Shiv S.; Leelavathi, Sadhu; Reddy, Vanga S.; Govindjee; Tripathy, Baishnab C.

2012-01-01

Chlorophyll b is synthesized by the oxidation of a methyl group on the B ring of a tetrapyrrole molecule to a formyl group by chlorophyllide a oxygenase (CAO). The full-length CAO from Arabidopsis (Arabidopsis thaliana) was overexpressed in tobacco (Nicotiana tabacum) that grows well at light intensities much higher than those tolerated by Arabidopsis. This resulted in an increased synthesis of glutamate semialdehyde, 5-aminolevulinic acid, magnesium-porphyrins, and chlorophylls. Overexpression of CAO resulted in increased chlorophyll b synthesis and a decreased chlorophyll a/b ratio in low light-grown as well as high light-grown tobacco plants; this effect, however, was more pronounced in high light. The increased potential of the protochlorophyllide oxidoreductase activity and chlorophyll biosynthesis compensated for the usual loss of chlorophylls in high light. Increased chlorophyll b synthesis in CAO-overexpressed plants was accompanied not only by an increased abundance of light-harvesting chlorophyll proteins but also of other proteins of the electron transport chain, which led to an increase in the capture of light as well as enhanced (40%–80%) electron transport rates of photosystems I and II at both limiting and saturating light intensities. Although the quantum yield of carbon dioxide fixation remained unchanged, the light-saturated photosynthetic carbon assimilation, starch content, and dry matter accumulation increased in CAO-overexpressed plants grown in both low- and high-light regimes. These results demonstrate that controlled up-regulation of chlorophyll b biosynthesis comodulates the expression of several thylakoid membrane proteins that increase both the antenna size and the electron transport rates and enhance carbon dioxide assimilation, starch content, and dry matter accumulation. PMID:22419827

Hepatic Overexpression of Endothelial Lipase Lowers HDL (High-Density Lipoprotein) but Maintains Reverse Cholesterol Transport in Mice: Role of SR-BI (Scavenger Receptor Class B Type I)/ABCA1 (ATP-Binding Cassette Transporter A1)-Dependent Pathways.

PubMed

Takiguchi, Shunichi; Ayaori, Makoto; Yakushiji, Emi; Nishida, Takafumi; Nakaya, Kazuhiro; Sasaki, Makoto; Iizuka, Maki; Uto-Kondo, Harumi; Terao, Yoshio; Yogo, Makiko; Komatsu, Tomohiro; Ogura, Masatsune; Ikewaki, Katsunori

2018-05-10

Reverse cholesterol transport (RCT) is a major mechanism by which HDL (high-density lipoprotein) protects against atherosclerosis. Endothelial lipase (EL) reportedly reduces HDL levels, which, in theory, would increase atherosclerosis. However, it remains unclear whether EL affects RCT in vivo. Adenoviral vectors expressing EL or luciferase were intravenously injected into mice, and a macrophage RCT assay was performed. As expected, hepatic EL overexpression markedly reduced HDL levels. In parallel, plasma 3 H-cholesterol counts from the EL-expressing mice decreased by 85% compared with control. Surprisingly, there was no difference in fecal 3 H-cholesterol excretion between the groups. Kinetic studies revealed increased catabolism/hepatic uptake of 3 HDL-cholesteryl ether, resulting in no change in fecal HDL-cholesteryl ester excretion in the mice. To explore underlying mechanisms for the preservation of RCT despite low HDL levels in the EL-expressing mice, we investigated the effects of hepatic SR-BI (scavenger receptor class B type I) knockdown. RCT assay revealed that knockdown of SR-BI alone reduced fecal excretion of macrophage-derived 3 H-cholesterol. Interestingly, hepatic EL overexpression under SR-BI inhibition further attenuated fecal tracer counts as compared with control. Finally, we observed that EL overexpression enhanced in vivo RCT under pharmacological inhibition of hepatic ABCA1 (ATP-binding cassette transporter A1) by probucol. Hepatic EL expression compensates for reduced macrophage-derived cholesterol efflux to plasma because of low HDL levels by promoting cholesterol excretion to bile/feces via an SR-BI pathway, maintaining overall RCT in vivo. In contrast, EL-modified HDL might negatively regulate RCT via hepatic ABCA1. Despite extreme hypoalphalipoproteinemia, RCT is maintained in EL-expressing mice via SR-BI/ABCA1-dependent pathways. © 2018 American Heart Association, Inc.

HOXB7 overexpression in lung cancer is a hallmark of acquired stem-like phenotype.

PubMed

Monterisi, Simona; Lo Riso, Pietro; Russo, Karin; Bertalot, Giovanni; Vecchi, Manuela; Testa, Giuseppe; Di Fiore, Pier Paolo; Bianchi, Fabrizio

2018-03-26

HOXB7 is a homeodomain (HOX) transcription factor involved in regional body patterning of invertebrates and vertebrates. We previously identified HOXB7 within a ten-gene prognostic signature for lung adenocarcinoma, where increased expression of HOXB7 was associated with poor prognosis. This raises the question of how HOXB7 overexpression can influence the metastatic behavior of lung adenocarcinoma. Here, we analyzed publicly available microarray and RNA-seq lung cancer expression datasets and found that HOXB7-overexpressing tumors are enriched in gene signatures characterizing adult and embryonic stem cells (SC), and induced pluripotent stem cells (iPSC). Experimentally, we found that HOXB7 upregulates several canonical SC/iPSC markers and sustains the expansion of a subpopulation of cells with SC characteristics, through modulation of LIN28B, an emerging cancer gene and pluripotency factor, which we discovered to be a direct target of HOXB7. We validated this new circuit by showing that HOXB7 enhances reprogramming to iPSC with comparable efficiency to LIN28B or its target c-MYC, which is a canonical reprogramming factor.

Responses of hybrid aspen over-expressing a PIP2;5 aquaporin to low root temperature.

PubMed

Ranganathan, Kapilan; El Kayal, Walid; Cooke, Janice E K; Zwiazek, Janusz J

2016-03-15

Aquaporins mediate the movement of water across cell membranes. Plasma membrane intrinsic protein 2;5 from Populus trichocarpa×deltoides (PtdPIP2;5) was previously demonstrated to be a functionally important water conducting aquaporin. To study the relevance of aquaporin-mediated root water transport at low temperatures, we generated transgenic Populus tremula×alba over-expressing PtdPIP2;5 under control of the maize ubiquitin promoter, and compared the physiological responses and water transport properties of the PtdPIP2;5 over-expressing lines (PtdPIP2;5ox) with wild-type plants. We hypothesized that over-expression of PtdPIP2;5 would reduce temperature sensitivity of root water transport and gas exchange. Decreasing root temperatures to 10 and 5°C significantly decreased hydraulic conductivities (Lp) in wild-type plants, but had no significant effect on Lp in PtdPIP2;5ox plants. Recovery of Lp in the transgenic lines returned to 20°C from 5°C was faster than in the wild-type plants. Low root temperature did not induce major changes in transcript levels for other PIPs. When roots were exposed to 5°C in solution culture and shoots were exposed to 20°C, wild-type plants had significantly lower net photosynthetic and transpiration rates compared to PtdPIP2;5ox plants. Taken together, our results demonstrate that over-expression of PtdPIP2;5 in P. tremula×alba was effective in alleviating the effects of low root temperature on Lp and gas exchange. Copyright © 2016 Elsevier GmbH. All rights reserved.

SLP-2 overexpression is associated with tumour distant metastasis and poor prognosis in pulmonary squamous cell carcinoma.

PubMed

Chang, Dong; Ma, Kai; Gong, Min; Cui, Yong; Liu, Zhi-hua; Zhou, Xiao-ge; Zhou, Chuan-nong; Wang, Tian-you

2010-03-01

To investigate the role of stomatin-like protein 2 (SLP-2), a novel cancer-related gene, in pulmonary squamous cell carcinoma (PSCC) and its implications. Immunohistochemical detection of SLP-2 was performed on 96 cases of PSCC with a tissue microarray. SLP-2 was overexpressed in lung cancer compared with normal lung tissue (p <0.001). High-level SLP-2 expression was significantly correlated with distant metastasis (p = 0.025), decreased overall survival (p = 0.018) and disease-free survival (p = 0.017). SLP-2 overexpression was an independent prognostic factor in multivariate analysis using the Cox regression model (p <0.05). SLP-2 overexpression is associated with tumour distant metastasis and poor prognosis in PSCC. SLP-2 could be regarded as a new significant prognostic biomarker for patients with PSCC.

Overexpression of GmHsp90s, a Heat Shock Protein 90 (Hsp90) Gene Family Cloning from Soybean, Decrease Damage of Abiotic Stresses in Arabidopsis thaliana

PubMed Central

Xue, Dong; Zhao, Jinming; Gai, Junyi; Guo, Na; Xing, Han

2013-01-01

Hsp90 is one of the most conserved and abundant molecular chaperones and is an essential component of the protective stress response; however, its roles in abiotic stress responses in soybean (Glycine max) remain obscure. Here, 12 GmHsp90 genes from soybean were identified and found to be expressed and to function differentially under abiotic stresses. The 12 GmHsp90 genes were isolated and named GmHsp90A1–GmHsp90A6, GmHsp90B1, GmHsp90B2, GmHsp90C1.1, GmHsp90C1.2, GmHsp90C2.1 and GmHsp90C2.2 based on their characteristics and high homology to other Hsp90s according to a new nomenclature system. Quantitative real-time PCR expression data revealed that all the genes exhibited higher transcript levels in leaves and could be strongly induced under heat, osmotic and salt stress but not cold stress. Overexpression of five typical genes (GmHsp90A2, GmHsp90A4, GmHsp90B1, GmHsp90C1.1 and GmHsp90C2.1) in Arabidopsis thaliana provided useful evidences that GmHsp90 genes can decrease damage of abiotic stresses. In addition, an abnormal accumulation of proline was detected in some transgenic Arabidopsis plants suggested overexpressing GmHsp90s may affect the synthesis and response system of proline. Our work represents a systematic determination of soybean genes encoding Hsp90s, and provides useful evidence that GmHsp90 genes function differently in response to abiotic stresses and may affect the synthesis and response system of proline. PMID:23936107

Central administration of insulin-like growth factor-I decreases depressive-like behavior and brain cytokine expression in mice

PubMed Central

2011-01-01

Exogenous administration of insulin-like growth factor (IGF)-I has anti-depressant properties in rodent models of depression. However, nothing is known about the anti-depressant properties of IGF-I during inflammation, nor have mechanisms by which IGF-I alters behavior following activation of the innate immune system been clarified. We hypothesized that central IGF-I would diminish depressive-like behavior on a background of an inflammatory response and that it would do so by inducing expression of the brain-derived neurotrophic factor (BDNF) while decreasing pro-inflammatory cytokine expression in the brain. IGF-I (1,000 ng) was administered intracerebroventricularly (i.c.v.) to CD-1 mice. Mice were subsequently given lipopolysaccharide i.c.v. (LPS, 10 ng). Sickness and depressive-like behaviors were assessed followed by analysis of brain steady state mRNA expression. Central LPS elicited typical transient signs of sickness of mice, including body weight loss, reduced feed intake and decreased social exploration toward a novel juvenile. Similarly, LPS increased time of immobility in the tail suspension test (TST). Pretreatment with IGF-I or antidepressants significantly decreased duration of immobility in the TST in both the absence and presence of LPS. To elucidate the mechanisms underlying the anti-depressant action of IGF-I, we quantified steady-state mRNA expression of inflammatory mediators in whole brain using real-time RT-PCR. LPS increased, whereas IGF-I decreased, expression of inflammatory markers interleukin-1ß (IL-1ß), tumor necrosis factor-(TNF)α, inducible nitric oxide synthase (iNOS) and glial fibrillary acidic protein (GFAP). Moreover, IGF-I increased expression of BDNF. These results indicate that IGF-I down regulates glial activation and induces expression of an endogenous growth factor that shares anti-depressant activity. These actions of IGF-I parallel its ability to diminish depressive-like behavior. PMID:21306618

MicroRNA-29c overexpression inhibits proliferation and promotes apoptosis and differentiation in P19 embryonal carcinoma cells.

PubMed

Liu, Ming; Chen, Yumei; Song, Guixian; Chen, Bin; Wang, Lihua; Li, Xing; Kong, Xiangqing; Shen, Yahui; Qian, Lingmei

2016-01-15

Compared to healthy controls, microRNA-29c (miR-29c) is highly expressed in the heart during progression towards ventricular septal defect. However, studies on miR-29c function in heart development are scarce. We investigated the role of miR-29c in P19 cell proliferation, apoptosis, and differentiation and the underlying mechanisms. We evaluated proliferation and cell cycle progression, detected morphological changes; apoptosis rate; BAX, BCL2, GATA binding protein 4 (GATA4), cardiac troponin T (cTnT), and myocyte enhancer factor 2C (MEF2C) expression; and caspase-3, -8, and -9 activity in miR-29c-overexpressing P19 cells, and investigated whether WNT4 was a miR-29c target. MiR-29c-overexpressing cells had decreased proliferation, increased G1 cells, and significantly higher apoptotic rate than the controls. Expression of the apoptosis-related BAX and BCL2 genes and caspase-3, -8, and -9 activity were significantly increased in miR-29c-overexpressing cells. Expression of the cardiac-specific markers GATA4, cTnT, and MEF2C revealed promoted differentiation in miR-29c-overexpressing cells compared to the controls. Luciferase assay confirmed that WNT4 is a miR-29c target. Wnt4 and β-catenin expression was decreased in miR-29c-overexpressing cells. MiR-29c inhibits P19 cell proliferation and promotes apoptosis and differentiation, possibly by suppressing Wnt4 signaling, whose deregulation contributes to congenital heart disease development. Copyright © 2015 Elsevier B.V. All rights reserved.

The Pim kinase inhibitor SGI-1776 decreases cell surface expression of P-glycoprotein (ABCB1) and breast cancer resistance protein (ABCG2) and drug transport by Pim-1-dependent and -independent mechanisms

PubMed Central

Natarajan, Karthika; Bhullar, Jasjeet; Shukla, Suneet; Burcu, Mehmet; Chen, Zhe-Sheng; Ambudkar, Suresh V.; Baer, Maria R.

2013-01-01

Overexpression of the ATP-binding cassette (ABC) drug efflux proteins P-glycoprotein (ABCB1) and breast cancer resistance protein (ABCG2) on malignant cells is associated with inferior chemotherapy outcomes. Both, ABCB1 and ABCG2, are substrates of the serine/threonine kinase Pim-1; Pim-1 knockdown decreases their cell surface expression, but SGI-1776, the first clinically tested Pim inhibitor, was shown to reverse drug resistance by directly inhibiting ABCB1-mediated transport. We sought to characterize Pim-1-dependent and -independent effects of SGI-1776 on drug resistance. SGI-1776 at the Pim-1-inhibitory and non-cytotoxic concentration of 1 μM decreased the IC50s of the ABCG2 and ABCB1 substrate drugs in cytotoxicity assays in resistant cells, with no effect on the IC50 of non-substrate drug, nor in parental cells. SGI-1776 also increased apoptosis of cells overexpressing ABCG2 or ABCB1 exposed to substrate chemotherapy drugs and decreased their colony formation in the presence of substrate, but not non-substrate, drugs, with no effect on parental cells. SGI-1776 decreased ABCB1 and ABCG2 surface expression on K562/ABCB1 and K562/ABCG2 cells, respectively, with Pim-1 overexpression, but not HL60/VCR and 8226/MR20 cells, with lower-level Pim-1 expression. Finally, SGI-1776 inhibited uptake of ABCG2 and ABCB1 substrates in a concentration-dependent manner irrespective of Pim-1 expression, inhibited ABCB1 and ABCG2 photoaffinity labeling with the transport substrate [125I]iodoarylazidoprazosin ([125I]IAAP) and stimulated ABCB1 and ABCG2 ATPase activity. Thus SGI-1776 decreases cell surface expression of ABCB1 and ABCG2 and inhibits drug transport by Pim-1-dependent and -independent mechanisms, respectively. Decrease in ABCB1 and ABCG2 cell surface expression mediated by Pim-1 inhibition represents a novel mechanism of chemosensitization. PMID:23261525

The Pim kinase inhibitor SGI-1776 decreases cell surface expression of P-glycoprotein (ABCB1) and breast cancer resistance protein (ABCG2) and drug transport by Pim-1-dependent and -independent mechanisms.

PubMed

Natarajan, Karthika; Bhullar, Jasjeet; Shukla, Suneet; Burcu, Mehmet; Chen, Zhe-Sheng; Ambudkar, Suresh V; Baer, Maria R

2013-02-15

Overexpression of the ATP-binding cassette (ABC) drug efflux proteins P-glycoprotein (ABCB1) and breast cancer resistance protein (ABCG2) on malignant cells is associated with inferior chemotherapy outcomes. Both, ABCB1 and ABCG2, are substrates of the serine/threonine kinase Pim-1; Pim-1 knockdown decreases their cell surface expression, but SGI-1776, the first clinically tested Pim inhibitor, was shown to reverse drug resistance by directly inhibiting ABCB1-mediated transport. We sought to characterize Pim-1-dependent and -independent effects of SGI-1776 on drug resistance. SGI-1776 at the Pim-1-inhibitory and non-cytotoxic concentration of 1 μM decreased the IC(50)s of the ABCG2 and ABCB1 substrate drugs in cytotoxicity assays in resistant cells, with no effect on the IC(50) of non-substrate drug, nor in parental cells. SGI-1776 also increased apoptosis of cells overexpressing ABCG2 or ABCB1 exposed to substrate chemotherapy drugs and decreased their colony formation in the presence of substrate, but not non-substrate, drugs, with no effect on parental cells. SGI-1776 decreased ABCB1 and ABCG2 surface expression on K562/ABCB1 and K562/ABCG2 cells, respectively, with Pim-1 overexpression, but not HL60/VCR and 8226/MR20 cells, with lower-level Pim-1 expression. Finally, SGI-1776 inhibited uptake of ABCG2 and ABCB1 substrates in a concentration-dependent manner irrespective of Pim-1 expression, inhibited ABCB1 and ABCG2 photoaffinity labeling with the transport substrate [(125)I]iodoarylazidoprazosin ([(125)I]IAAP) and stimulated ABCB1 and ABCG2 ATPase activity. Thus SGI-1776 decreases cell surface expression of ABCB1 and ABCG2 and inhibits drug transport by Pim-1-dependent and -independent mechanisms, respectively. Decrease in ABCB1 and ABCG2 cell surface expression mediated by Pim-1 inhibition represents a novel mechanism of chemosensitization. Copyright © 2012 Elsevier Inc. All rights reserved.

Metallothionein expression in canine and feline mammary and melanotic tumours.

PubMed

Dincer, Z; Jasani, B; Haywood, S; Mullins, J E; Fuentealba, I C

2001-01-01

Moderate to strong immunohistochemical metallothionein (MT) positivity (MT expression) is associated with a poor prognosis in some human tumours. The aim of this study was to determine MT expression in mammary tumours and cutaneous melanomas in dogs and cats. Canine (67) and feline (47) mammary tumours, and cutaneous melanomas (canine 40, feline 26) were immunolabelled with MT monoclonal antibody E9. The overall incidence of MT expression of these tumours was similar to that observed in various human neoplasms. However, a striking interspecies difference was detected. In dogs, MT expression occurred in 100% of benign and 57% of malignant mammary tumours. In cats, however, 30% of malignant mammary tumours expressed MT but benign mammary tumours and cases of fibroadenomatous hyperplasia did not. Moderate to strong MT immunoreactivity was detected in 30% of benign and 25% of malignant cutaneous melanomas in dogs, and in 6% of malignant melanomas in cats. The findings in feline mammary tumours resembled findings reported in human breast cancer, but the cause of tumour-associated MT expression is unknown. Studies are in progress to determine whether the MT state (apo [metal-free] or holo [metal-bound]) accounts for the paradoxical association of MT expression with individual types of tumours and the animal species in which they arise. Copyright Harcourt Publishers Ltd.

Polyphenol-rich beverages enhance zinc uptake and metallothionein expression in Caco-2 cells.

PubMed

Sreenivasulu, Kilari; Raghu, Pullakhandam; Nair, K Madhavan

2010-05-01

The effect of red wine (RW), red grape juice (RGJ), green tea (GT), and representative polyphenols on Caco-2 cell (65)Zn uptake was explored. RW, RGJ, and GT enhanced the uptake of zinc from rice matrix. Fractionation of RW revealed that enhancing activity of zinc uptake was exclusively resided in the polyphenol fraction. Among the polyphenols tested, only tannic acid and quercitin stimulated the uptake of zinc while others did not influence the uptake. In tune with these results, only tannic acid and quercitin competed with zinquin (a zinc selective fluorophore) for zinc in vitro. Although all the polyphenols tested appear to enhance the expression of metallothionein (MT), the induction was higher with tannic acid, quercitin, and RW extract. Furthermore, phytic acid abrogated the tannic acid-induced MT expression. These results suggest that polyphenol-rich beverages, tannic acid, and quercitin bind and stimulate the zinc uptake and MT expression in Caco-2 cells.

IL-10-overexpressing B cells regulate innate and adaptive immune responses.

PubMed

Stanic, Barbara; van de Veen, Willem; Wirz, Oliver F; Rückert, Beate; Morita, Hideaki; Söllner, Stefan; Akdis, Cezmi A; Akdis, Mübeccel

2015-03-01

Distinct human IL-10-producing B-cell subsets with immunoregulatory properties have been described. However, the broader spectrum of their direct cellular targets and suppressive mechanisms has not been extensively studied, particularly in relation to direct and indirect IL-10-mediated functions. The aim of the study was to investigate the effects of IL-10 overexpression on the phenotype and immunoregulatory capacity of B cells. Primary human B cells were transfected with hIL-10, and IL-10-overexpressing B cells were characterized for cytokine and immunoglobulin production by means of specific ELISA and bead-based assays. Antigen presentation, costimulation capacity, and transcription factor signatures were analyzed by means of flow cytometry and quantitative RT-PCR. Effects of IL-10-overexpresing B cells on Toll-like receptor-triggered cytokine release from PBMCs, LPS-triggered maturation of monocyte-derived dendritic cells, and tetanus toxoid-induced PBMC proliferation were assessed in autologous cocultures. IL-10-overexpressing B cells acquired a prominent immunoregulatory profile comprising upregulation of suppressor of cytokine signaling 3 (SOCS3), glycoprotein A repetitions predominant (GARP), the IL-2 receptor α chain (CD25), and programmed cell death 1 ligand 1 (PD-L1). Concurrently, their secretion profile was characterized by a significant reduction in levels of proinflammatory cytokines (TNF-α, IL-8, and macrophage inflammatory protein 1α) and augmented production of anti-inflammatory IL-1 receptor antagonist and vascular endothelial growth factor. Furthermore, IL-10 overexpression was associated with a decrease in costimulatory potential. IL-10-overexpressing B cells secreted less IgE and potently suppressed proinflammatory cytokines in PBMCs, maturation of monocyte-derived dendritic cells (rendering their profile to regulatory phenotype), and antigen-specific proliferation in vitro. Our data demonstrate an essential role for IL-10 in inducing an

Overexpression of isocitrate dehydrogenase mutant proteins renders glioma cells more sensitive to radiation.

PubMed

Li, Sichen; Chou, Arthur P; Chen, Weidong; Chen, Ruihuan; Deng, Yuzhong; Phillips, Heidi S; Selfridge, Julia; Zurayk, Mira; Lou, Jerry J; Everson, Richard G; Wu, Kuan-Chung; Faull, Kym F; Cloughesy, Timothy; Liau, Linda M; Lai, Albert

2013-01-01

Mutations in isocitrate dehydrogenase 1 (IDH1) or 2 (IDH2) are found in a subset of gliomas. Among the many phenotypic differences between mutant and wild-type IDH1/2 gliomas, the most salient is that IDH1/2 mutant glioma patients demonstrate markedly improved survival compared with IDH1/2 wild-type glioma patients. To address the mechanism underlying the superior clinical outcome of IDH1/2 mutant glioma patients, we investigated whether overexpression of the IDH1(R132H) protein could affect response to therapy in the context of an isogenic glioma cell background. Stable clonal U87MG and U373MG cell lines overexpressing IDH1(WT) and IDH1(R132H) were generated, as well as U87MG cell lines overexpressing IDH2(WT) and IDH2(R172K). In vitro experiments were conducted to characterize baseline growth and migration and response to radiation and temozolomide. In addition, reactive oxygen species (ROS) levels were measured under various conditions. U87MG-IDH1(R132H) cells, U373MG-IDH1(R132H) cells, and U87MG-IDH2(R172K) cells demonstrated increased sensitivity to radiation but not to temozolomide. Radiosensitization of U87MG-IDH1(R132H) cells was accompanied by increased apoptosis and accentuated ROS generation, and this effect was abrogated by the presence of the ROS scavenger N-acetyl-cysteine. Interestingly, U87MG-IDH1(R132H) cells also displayed decreased growth at higher cell density and in soft agar, as well as decreased migration. Overexpression of IDH1(R132H) and IDH2(R172K) mutant protein in glioblastoma cells resulted in increased radiation sensitivity and altered ROS metabolism and suppression of growth and migration in vitro. These findings provide insight into possible mechanisms contributing to the improved outcomes observed in patients with IDH1/2 mutant gliomas.

[Overexpressed miRNA-134b inhibits proliferation and invasion of CD133+ U87 glioma stem cells].

PubMed

Liu, Yifeng; Zhang, Baochao; Wen, Changming; Wen, Gongling; Zhou, Guoping; Zhang, Jingwei; He, Haifa; Wang, Ning; Li, Wei

2017-05-01

Objective To investigate the role of microRNA-134b (miR-134b) in the tumorigenesis of glioma stem cells (GSCs) and the possible molecular mechanism. Methods Real-time quantitative PCR (qRT-PCR) was used to evalate the expression of miR-134b in CD133 + and CD133 - U87 GSCs. A lentiviral vector overexpressing miR-134b in U87 GSCs was constructed, and the effect of miR-134b overexpression on matrix metalloproteinase-2 (MMP-2), MMP-9 and MMP-12 expressions at both mRNA and protein levels were detected by qRT-PCR and Western blotting, respectively. Transwell TM assay was performed to determine the effect of miR-134b overexpression on GSCs invasion ability. Tumor xenograft models in nude mice were established to evaluate the effect of miR-134b overexpression on tumorgenesis in vivo. Results The qRT-PCR showed that, compared with CD133 - cells, miR-134b was significantly down-regulated in CD133 + cells. Cell line over-expressing miR-134b was successfully established, and miR-134b was up-regulated significantly compared with empty vector control. Overexpression of miR-134b remarkably inhibited the invasion of U87 GSCs and the expression of MMP-12. However, overexpression of miR-134b did not affect MMP-2 and MMP-9 expressions. miR-134b also suppressed U87 GSCs xenograft growth in vivo. Tumor volume in tumor xenograft model group was significantly lower than that in control group, and tumor weight decreased by 42% in the former group. Conclusion Overexpression of miR-134b inhibits the growth and invasion of CD133 + GSCs.

Enhancing cellulase production by overexpression of xylanase regulator protein gene, xlnR, in Talaromyces cellulolyticus cellulase hyperproducing mutant strain.

PubMed

Okuda, Naoyuki; Fujii, Tatsuya; Inoue, Hiroyuki; Ishikawa, Kazuhiko; Hoshino, Tamotsu

2016-10-01

We obtained strains with the xylanase regulator gene, xlnR, overexpressed (HXlnR) and disrupted (DXlnR) derived from Talaromyces cellulolyticus strain C-1, which is a cellulase hyperproducing mutant. Filter paper degrading enzyme activity and cellobiohydrolase I gene expression was the highest in HXlnR, followed by C-1 and DXlnR. These results indicate that the enhancement of cellulase productivity was succeeded by xlnR overexpression.

A decrease in intact parathyroid hormone (iPTH) levels is associated with higher mortality in prevalent hemodialysis patients

PubMed Central

Villa-Bellosta, Ricardo; Rodriguez-Osorio, Laura; Mas, Sebastian; Abadi, Younes; Rubert, Mercedes; de la Piedra, Concepción; Gracia-Iguacel, Carolina; Mahillo, Ignacio; Ortiz, Alberto; Egido, Jesús; González-Parra, Emilio

2017-01-01

Background The mortality of dialysis patients is 10- to 100-fold higher than in the general population. Baseline serum PTH levels, and more recently, changes in serum PTH levels (ΔPTH) over time, have been associated to mortality in dialysis patients. Methods We explored the relationship between ΔPTH over 1 year with mortality over the next year in a prospective cohort of 115 prevalent hemodialysis patients from a single center that had median baseline iPTH levels within guideline recommendations. Results Median baseline iPTH levels were 205 (116.5, 400) pg/ml. ΔiPTH between baseline and 1 year was 85.2 ± 57.1 pg/ml. During the second year of follow-up, 27 patients died. ΔiPTH was significantly higher in patients who survived (+157.30 ± 25.82 pg/ml) than in those who died (+39.03 ± 60.95 pg/ml), while baseline iPTH values were not significantly different. The highest mortality (48%) was observed in patients with a decrease in ΔiPTH (ΔiPTH quartile 1, negative ΔiPTH) and the lowest (12%) mortality in quartile 3 ΔiPTH (ΔiPTH increase 101–300 pg/ml). In a logistic regression model, ΔiPTH was associated with mortality with an odds ratio (OR) of 0.998 (95% CI 0.996–0999, p = 0.038). In multivariable analysis, mortality risk was 73% and 88% lower for patients with ΔiPTH 0–100 pg/ml and 101–300 pg/ml, respectively, than for those with a decrease in ΔiPTH. In patients with a decrease in ΔiPTH, the OR for death was 4.131 (1.515–11.27)(p = 0.006). Conclusions In prevalent hemodialysis patients with median baseline iPTH values within the guideline recommended range, a decrease in ΔiPTH was associated with higher mortality. Further studies are required to understand the mechanisms and therapeutic implications of this observation that challenges current clinical practice. PMID:28339474

Expression of insulin-like growth factor-2 receptors on EL4 lymphoma cells overexpressing growth hormone.

PubMed

Farmer, John T; Weigent, Douglas A

2007-01-01

In the present study, we report the upregulation of functional IGF-2Rs in cells overexpressing growth hormone (GH). EL4 lymphoma cells stably transfected with an rGH cDNA overexpression vector (GHo) exhibited an increase in the binding of (125)I-IGF-2 with no change in the binding affinity compared to vector alone controls. An increase in the expression of the insulin-like growth factor-2 receptor (IGF-2R) in cells overexpressing GH was confirmed by Western blot analysis and IGF-2R promoter luciferase assays. EL4 cells produce insulin-like growth factor-2 (IGF-2) as detected by the reverse transcription-polymerase chain reaction (RT-PCR); however, no IGF-2 protein was detected by Western analysis. The increase in the expression of the IGF-2R resulted in greater levels of IGF-2 uptake in GHo cells compared to vector alone controls. The data suggest that one of the consequences of the overexpression of GH is an increase in the expression of the IGF-2R.

Overexpression of Tet3 in donor cells enhances goat somatic cell nuclear transfer efficiency.

PubMed

Han, Chengquan; Deng, Ruizhi; Mao, Tingchao; Luo, Yan; Wei, Biao; Meng, Peng; Zhao, Lu; Zhang, Qing; Quan, Fusheng; Liu, Jun; Zhang, Yong

2018-05-23

Ten-eleven translocation 3 (TET3) mediates active DNA demethylation of paternal genomes during mouse embryonic development. However, the mechanism of DNA demethylation in goat embryos remains unknown. In addition, aberrant DNA methylation reprogramming prevalently occurs in embryos cloned by somatic cell nuclear transfer (SCNT). In this study, we reported that TET3 is a key factor in DNA demethylation in goat pre-implantation embryos. Knockdown of Tet3 hindered DNA demethylation at the two- to four-cell stage in goat embryos and decreased Nanog expression in blastocysts. Overexpression of Tet3 in somatic cells can initiate DNA demethylation, reduce 5-methylcytosine level, increase 5-hydroxymethylcytosine level and promote the expression of key pluripotency genes. After SCNT, overexpression of Tet3 in donor cells corrected abnormal DNA hypermethylation of cloned embryos and significantly enhanced in vitro and in vivo developmental rate (P < 0.05). We conclude that overexpression of Tet3 in donor cells significantly improves goat SCNT efficiency. © 2018 Federation of European Biochemical Societies.

Overexpression of the base excision repair NTHL1 glycosylase causes genomic instability and early cellular hallmarks of cancer

PubMed Central

Limpose, Kristin L; Trego, Kelly S; Li, Zhentian; Leung, Sara W; Sarker, Altaf H; Shah, Jason A; Ramalingam, Suresh S; Werner, Erica M; Dynan, William S; Cooper, Priscilla K; Corbett, Anita H; Doetsch, Paul W

2018-01-01

Abstract Base excision repair (BER), which is initiated by DNA N-glycosylase proteins, is the frontline for repairing potentially mutagenic DNA base damage. The NTHL1 glycosylase, which excises DNA base damage caused by reactive oxygen species, is thought to be a tumor suppressor. However, in addition to NTHL1 loss-of-function mutations, our analysis of cancer genomic datasets reveals that NTHL1 frequently undergoes amplification or upregulation in some cancers. Whether NTHL1 overexpression could contribute to cancer phenotypes has not yet been explored. To address the functional consequences of NTHL1 overexpression, we employed transient overexpression. Both NTHL1 and a catalytically-dead NTHL1 (CATmut) induce DNA damage and genomic instability in non-transformed human bronchial epithelial cells (HBEC) when overexpressed. Strikingly, overexpression of either NTHL1 or CATmut causes replication stress signaling and a decrease in homologous recombination (HR). HBEC cells that overexpress NTHL1 or CATmut acquire the ability to grow in soft agar and exhibit loss of contact inhibition, suggesting that a mechanism independent of NTHL1 catalytic activity contributes to acquisition of cancer-related cellular phenotypes. We provide evidence that NTHL1 interacts with the multifunctional DNA repair protein XPG suggesting that interference with HR is a possible mechanism that contributes to acquisition of early cellular hallmarks of cancer. PMID:29522130

Ubiquilin overexpression reduces GFP-polyalanine-induced protein aggregates and toxicity

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

Wang Hongmin; Monteiro, Mervyn J.

2007-08-01

Several human disorders are associated with an increase in a continuous stretch of alanine amino acids in proteins. These so-called polyalanine expansion diseases share many similarities with polyglutamine-related disorders, including a length-dependent reiteration of amino acid induction of protein aggregation and cytotoxicity. We previously reported that overexpression of ubiquilin reduces protein aggregates and toxicity of expanded polyglutamine proteins. Here, we demonstrate a similar role for ubiquilin toward expanded polyalanine proteins. Overexpression of ubiquilin-1 in HeLa cells reduced protein aggregates and the cytotoxicity associated with expression of a transfected nuclear-targeted GFP-fusion protein containing 37-alanine repeats (GFP-A37), in a dose dependent manner.more » Ubiquilin coimmunoprecipitated more with GFP proteins containing a 37-polyalanine tract compared to either 7 (GFP-A7), or no alanine tract (GFP). Moreover, overexpression of ubiquilin suppressed the increased vulnerability of HeLa cell lines stably expressing the GFP-A37 fusion protein to oxidative stress-induced cell death compared to cell lines expressing GFP or GFP-A7 proteins. By contrast, siRNA knockdown of ubiquilin expression in the GFP-A37 cell line was associated with decreased cellular proliferation, and increases in GFP protein aggregates, nuclear fragmentation, and cell death. Our results suggest that boosting ubiquilin levels in cells might provide a universal and attractive strategy to prevent toxicity of proteins containing reiterative expansions of amino acids involved in many human diseases.« less

Overexpression of 20-Oxidase Confers a Gibberellin-Overproduction Phenotype in Arabidopsis

PubMed Central

Huang, Shihshieh; Raman, Anuradha S.; Ream, Joel E.; Fujiwara, Hideji; Cerny, R. Eric; Brown, Sherri M.

1998-01-01

In the gibberellin (GA) biosynthesis pathway, 20-oxidase catalyzes the oxidation and elimination of carbon-20 to give rise to C19-GAs. All bioactive GAs are C19-GAs. We have overexpressed a cDNA encoding 20-oxidase isolated from Arabidopsis seedlings in transgenic Arabidopsis plants. These transgenic plants display a phenotype that may be attributed to the overproduction of GA. The phenotype includes a longer hypocotyl, lighter-green leaves, increased stem elongation, earlier flowering, and decreased seed dormancy. However, the fertility of the transgenic plants is not affected. Increased levels of endogenous GA1, GA9, and GA20 were detected in seedlings of the transgenic line examined. GA4, which is thought to be the predominantly active GA in Arabidopsis, was not present at increased levels in this line. These results suggest that the overexpression of this 20-oxidase increases the levels of some endogenous GAs in transgenic seedlings, which causes the GA-overproduction phenotype. PMID:9808721

TGF-beta1 expression in EL4 lymphoma cells overexpressing growth hormone.

PubMed

Farmer, John T; Weigent, Douglas A

2006-03-01

Our previous studies show that growth hormone overexpression (GHo) upregulates the expression of the IGF-1R and IGF-2R resulting in the protection of the EL4 lymphoma cell line from apoptosis. In this study, we report that GHo also increases TGF-beta1 protein expression measured by luciferase promoter assay, Western analysis, and ELISA. Further, the data show that antibody to TGF-betaR2 decreases TGF-beta1 promoter activity to the level of vector alone control cells. GHo cells treated with (125)I-rh-latent TGF-beta1 showed increased activation of latent TGF-beta1 as measured by an increase in the active 24kDa, TGF-beta1 compared to vector alone control cells. The ability of endogenous GH to increase TGF-beta1 expression is blocked in EL4 cells by antisense but not sense oligodeoxynucleotides or in cells cultured with antibody to growth hormone (GH). The data suggest that endogenous GH may protect from apoptosis through the IGF-1R receptor while limiting cellular growth through increased expression and activation of TGF-beta1.

Overexpression of angiotensin II type 2 receptor promotes apoptosis and impairs insulin secretion in rat insulinoma cells.

PubMed

Liu, Min; Jing, Danqing; Wang, Yan; Liu, Yu; Yin, Shinan

2015-02-01

Angiotensin II (Ang II), the major effector hormone of renin-angiotensin system, acts as a promoter of insulin resistance and diabetes mellitus type 2 pathogenesis. Activation of Ang II type 2 receptor (AT2R) has been examined as a potential therapeutic strategy. However, there are conflicting findings regarding the role of AT2R. In the current study, we evaluated the effects of overexpressing AT2R by viral vector transduction on the apoptosis and function of pancreatic β-islet cells. The rat insulinoma cell line, INS-1, was transduced with a recombinant adenoviral vector expressing AT2R (Ad-G-AT2R-EGFP). AT2R overexpression resulted in significantly reduced cell viability and subsequently impaired glucose-stimulated insulin secretion (GSIS) function in INS-1 cells. Down-regulated expressions of GSIS pathway components, insulin, glucose transporter 2, and glucokinase were associated with AT2R overexpression. Further analysis determined that overexpression of AT2R induced G1-phase cell cycle arrest and Ang II-independent apoptotic cell death as indicated by increased Annexin V staining. To understand the apoptosis signaling triggered by AT2R overexpression, levels of caspase proteins were measured. Overexpression of AT2R significantly induced caspase-8, caspase-9, and caspase-3 cleavage, and decreased Bcl-2, pAkt, and pERK expression levels. AT2R-induced cell apoptosis was successfully blocked by the caspase inhibitor Z-VAD-FMK. Our findings suggested that AT2R overexpression triggers the apoptosis of INS-1 cells and dysfunction in insulin secretion. In conclusion, more careful design and consideration are required when applying AT2R-related therapies in treating diabetes.

Expression of cytoprotective proteins, heat shock protein 70and metallothioneins, in tissues ofOstrea edulis exposed to heat andheavy metals

PubMed Central

Piano, Annamaria; Valbonesi, Paola; Fabbri, Elena

2004-01-01

Heat shock proteins (Hsps) are constitutively expressed in cells and involved in protein folding, assembly, degradation, intracellular localization, etc, acting as molecular chaperones. However, their overexpression represents a ubiquitous molecular mechanism to cope with stress. Hsps are classified into families, and among them the Hsp70 family appears to be the most evolutionary preserved and distributed in animals. In this study, the expression of Hsp70 and the related messenger ribonucleic acid (mRNA) has been studied in Ostrea edulis after exposure to heat and heavy metals; moreover, levels of metallothioneins (MTs), another class of stress-induced proteins, have contemporaneously been assessed in the same animals. Thermal stress caused the expression of a 69-kDa inducible isoform in gills of O edulis but not in the digestive gland. Northern dot blot analysis confirmed that the transcription of Hsp69-mRNA occurs within 3 hours of stress recovery after oyster exposure at 32 and 35°C. Hsp69-mRNA transcripts were not present in the gills of animals exposed to 38°C after 3 hours of poststress recovery, but they were detected after 24 hours. The expression of the 69-kDa protein in O edulis exposed to 38°C was rather low or totally absent, suggesting that the biochemical machinery at the base of the heat shock response is compromised. Together with the expected increase in MT content, the oysters exposed to Cd showed a significant enhancement of Hsp70, although there was no clear appearance of Hsp69. Interestingly, the levels of MT were significantly increased in the tissues of individuals exposed to thermal stress. Unlike oysters, heat did not provoke the expression of inducible Hsp isoforms in Mytilus galloprovincialis, Tapes philippinarum, and Scapharca inaequivalvis, although it significantly enhanced the expression of constitutive proteins of the 70-kDa family. The expression of newly synthesized Hsp70 isoforms does not seem therefore a common feature in

Overexpressing Ferredoxins in Chlamydomonas reinhardtii Increase Starch and Oil Yields and Enhance Electric Power Production in a Photo Microbial Fuel Cell

PubMed Central

Huang, Li-Fen; Lin, Ji-Yu; Pan, Kui-You; Huang, Chun-Kai; Chu, Ying-Kai

2015-01-01

Ferredoxins (FDX) are final electron carrier proteins in the plant photosynthetic pathway, and function as major electron donors in diverse redox-driven metabolic pathways. We previously showed that overexpression of a major constitutively expressed ferredoxin gene PETF in Chlamydomonas decreased the reactive oxygen species (ROS) level and enhanced tolerance to heat stress. In addition to PETF, an endogenous anaerobic induced FDX5 was overexpressed in transgenic Chlamydomonas lines here to address the possible functions of FDX5. All the independent FDX transgenic lines showed decreased cellular ROS levels and enhanced tolerance to heat and salt stresses. The transgenic Chlamydomonas lines accumulated more starch than the wild-type line and this effect increased almost three-fold in conditions of nitrogen depletion. Furthermore, the lipid content was higher in the transgenic lines than in the wild-type line, both with and without nitrogen depletion. Two FDX-overexpressing Chlamydomonas lines were assessed in a photo microbial fuel cell (PMFC); power density production by the transgenic lines was higher than that of the wild-type cells. These findings suggest that overexpression of either PETF or FDX5 can confer tolerance against heat and salt stresses, increase starch and oil production, and raise electric power density in a PMFC. PMID:26287179

Type 1 Deiodinase Regulates ApoA-I Gene Expression and ApoA-I Synthesis Independent of Thyroid Hormone Signaling

PubMed Central

Liu, Jing; Hernandez-Ono, Antonio; Graham, Mark J.; Galton, Valerie Anne; Ginsberg, Henry N.

2016-01-01

Objective Plasma levels of high density lipoprotein cholesterol (HDLC) and apolipoprotein A-I (ApoA-I) are reduced in individuals with defective insulin signaling. Initial studies using liver-specific insulin receptor (InsR) knockout mice (LIRKO) identified reduced expression of Type 1 Deiodinase (Dio1) as a potentially novel link between defective hepatic insulin signaling and reduced expression of the ApoA-I gene. Our objective was to examine the regulation of ApoA-I expression by Dio1. Approach and Results Acute inactivation of InsR by adenoviral delivery of Cre recombinase to InsR floxed mice reduced HDLC and expression of both ApoA-I and Dio1. Overexpression of Dio1 in LIRKO restored HDLC and ApoA-I levels and increased the expression of ApoA-I. Dio1 knockout (D1KO) mice had very low expression of ApoA-I and reduced serum levels of HDLC and ApoA-I. Treatment of C57BL/6J mice with anti-sense to Dio1 reduced ApoA-I mRNA, HDLC, and serum ApoA-I. Hepatic 3,5,3′-triiodothyronine (T3) content was normal or elevated in LIRKO or D1KO mice. Knockdown of either InsR or Dio1 by siRNA in HepG2 cells decreased expression of ApoA-I as well as ApoA-I synthesis and secretion. siRNA knockdown of InsR or Dio1 decreased activity of a region of the ApoA-I promoter lacking thyroid hormone response elements (TREs) (Region B). Electrophoretic mobility shift assay demonstrated that reduced Dio1 expression decreased the binding of nuclear proteins to Region B. Conclusions Reductions in Dio1 expression reduce expression of ApoA-I in a T3/TRE independent manner. PMID:27150392

Type 1 Deiodinase Regulates ApoA-I Gene Expression and ApoA-I Synthesis Independent of Thyroid Hormone Signaling.

PubMed

Liu, Jing; Hernandez-Ono, Antonio; Graham, Mark J; Galton, Valerie Anne; Ginsberg, Henry N

2016-07-01

Plasma levels of high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A-I (ApoA-I) are reduced in individuals with defective insulin signaling. Initial studies using liver-specific insulin receptor (InsR) knockout mice identified reduced expression of type 1 deiodinase (Dio1) as a potentially novel link between defective hepatic insulin signaling and reduced expression of the ApoA-I gene. Our objective was to examine the regulation of ApoA-I expression by Dio1. Acute inactivation of InsR by adenoviral delivery of Cre recombinase to InsR floxed mice reduced HDL-C and expression of both ApoA-I and Dio1. Overexpression of Dio1 in InsR knockout mice restored HDL-C and ApoA-I levels and increased the expression of ApoA-I. Dio1 knockout mice had low expression of ApoA-I and reduced serum levels of HDL-C and ApoA-I. Treatment of C57BL/6J mice with antisense to Dio1 reduced ApoA-I mRNA, HDL-C, and serum ApoA-I. Hepatic 3,5,3'-triiodothyronine content was normal or elevated in InsR knockout mice or Dio1 knockout mice. Knockdown of either InsR or Dio1 by siRNA in HepG2 cells decreased the expression of ApoA-I and ApoA-I synthesis and secretion. siRNA knockdown of InsR or Dio1 decreased activity of a region of the ApoA-I promoter lacking thyroid hormone response elements (region B). Electrophoretic mobility shift assay demonstrated that reduced Dio1 expression decreased the binding of nuclear proteins to region B. Reductions in Dio1 expression reduce the expression of ApoA-I in a 3,5,3'-triiodothyronine-/thyroid hormone response element-independent manner. © 2016 American Heart Association, Inc.

NDRG2 overexpression suppresses hepatoma cells survival during metabolic stress through disturbing the activation of fatty acid oxidation

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

Pan, Tao; Xi'an Medical University, Xi'an, Shaanxi Province; Zhang, Mei

Because of the high nutrient consumption and inadequate vascularization, solid tumor constantly undergoes metabolic stress during tumor development. Oncogenes and tumor suppressor genes participated in cancer cells' metabolic reprogramming. N-Myc downstream regulated gene 2 (NDRG2) is a recently identified tumor suppressor gene, but its function in cancer metabolism, particularly during metabolic stress, remains unclear. In this study, we found that NDRG2 overexpression significantly reduced hepatoma cell proliferation and enhanced cell apoptosis under glucose limitation. Moreover, NDRG2 overexpression aggravated energy imbalance and oxidative stress by decreasing the intracellular ATP and NADPH generation and increasing ROS levels. Strikingly, NDRG2 inhibited the activationmore » of fatty acid oxidation (FAO), which preserves ATP and NADPH purveyance in the absence of glucose. Finally, mechanistic investigation showed that NDRG2 overexpression suppressed the glucose-deprivation induced AMPK/ACC pathway activation in hepatoma cells, whereas the expression of a constitutively active form of AMPK abrogated glucose-deprivation induced AMPK activation and cell apoptosis. Thus, as a negative regulator of AMPK, NDRG2 disturbs the induction of FAO genes by glucose limitation, leading to dysregulation of ATP and NADPH, and thus reduces the tolerance of hepatoma cells to glucose limitation. - Highlights: • NDRG2 overexpression reduces the tolerance of hepatoma cells to glucose limitation. • NDRG2 overexpression aggravates energy imbalance and oxidative stress under glucose deprivation. • NDRG2 overexpression disturbs the activation of FAO in hepatoma cells under glucose limitation. • NDRG2 overexpression inhibits the activation of AMPK/ACC pathway in hepatoma cells during glucose starvation.« less

Overexpression of BMP3 in the developing skeleton alters endochondral bone formation resulting in spontaneous rib fractures.

PubMed

Gamer, Laura W; Cox, Karen; Carlo, Joelle M; Rosen, Vicki

2009-09-01

Bone morphogenetic protein-3 (BMP) has been identified as a negative regulator in the skeleton as mice lacking BMP3 have increased bone mass. To further understand how BMP3 mediates bone formation, we created transgenic mice overexpressing BMP3 using the type I collagen promoter. BMP3 transgenic mice displayed spontaneous rib fractures that were first detected at E17.0. The fractures were due to defects in differentiation of the periosteum and late hypertrophic chondrocytes resulting in thinner cortical bone with decreased mineralization. As BMP3 modulates BMP and activin signaling through ActRIIB, we examined the ribs of ActRIIB receptor knockout mice and found they had defects in late chondrogenesis and mineralization similar to BMP3 transgenic mice. These data suggest that BMP3 exerts its effects in the skeleton by altering signaling through ActRIIB in chondrocytes and the periosteum, and this results in defects in bone collar formation and late hypertrophic chondrocyte maturation leading to decreased mineralization and less bone. 2009 Wiley-Liss, Inc.

Zinc and dexamethasone induce metallothionein accumulation by endothelial cells

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

Briske-Anderson, M.; Bobilya, D.J.; Reeves, P.G.

1991-03-11

Several tissues increase their metallothionein (MT) concentration when exposed to elevated amounts of plasma Zn. Endothelial cells form the blood vessels that supply all tissues and constitute a barrier between cells of tissues and the blood. This study examined the ability of endothelial cells to synthesize MT and accumulate Zn in response to high amounts of Zn and dexamethasone. Bovine pulmonary endothelial cells were grown to confluence in Minimum Essential Medium with Earle's salts and 10% fetal calf serum. The monolayer was maintained for 2 d prior to use in medium containing EDTA-dialyzed serum. This low Zn medium was replacedmore » with one containing 1, 6, 25, 50, 100, 150, or 200 {mu}M Zn and incubated for 24 hr before harvesting the cells. MT was quantified by the cadmium binding assay. Cellular Zn concentrations were analyzed by atomic absorption after a nitric acid digestion. The MT concentration was elevated in response to Zn concentrations of 100 {mu}M or more. Cellular Zn concentration was elevated when media Zn was 25 {mu}M or more. MT and cellular Zn concentrations were positively correlated. In another study, inclusion of 0.1 {mu}M dexamethasone in the media increased concentration at all Zn concentrations studied. However, the inclusion of 0.3 {mu}M cis-platinum had no effect. In conclusion, endothelial cells in culture respond to elevated amounts of Zn and dexamethasone in the media by accumulating Zn and MT.« less

The role of metallothionein in oncogenesis and cancer treatment.

PubMed

Bizoń, Anna; Jędryczko, Kinga; Milnerowicz, Halina

2017-02-14

Metallothionein is cysteine-rich low molecular mass protein. The involvement of MT in many physiological and pathophysiological processes such as apoptosis, proliferation, angiogenesis, and the detoxification of heavy metals suggested participation of this protein in carcinogenesis and tumor therapy. Depending on the type of tissue and classification of carcinoma various it was observed relation between MT expression and tumor type, stage, grade, poor prognosis and body resistance to radiotherapy and chemotherapy. MT in tumor cell plays important role in defense mechanism against the effect of radiation by inhibiting the processes that lead to the apoptosis. A number of studies have shown an increased expression of MT in various human tumors of larynx, pancreas, kidney, uterus and breast, whereas lower MT expression was detected in liver tumors. Variable MT expression was detected in case of thyroid, prostate, lung, stomach and central nervous system tumors. Also MT plays crucial role in the cytostatics treatment. MT can bind cis-platinum compounds and removes them from the cells, which may lead to multidrug resistance. However, the same functions of MT protect against the negative effects of chemotherapeutic treatment. It is especially important in case of heart cells. Analysis of MT expression in tumor cells may be useful in choosing method of treatment. It is difficult to determine whether increased expression of MT is only a inducing factor of the development of the carcinogenesis, its malignances and multidrug resistance, or it is a factor inhibiting the induction and development of cancer.

Overexpression of IRM1 Enhances Resistance to Aphids in Arabidopsis thaliana

PubMed Central

Chen, Xi; Zhang, Zhao; Visser, Richard G. F.; Broekgaarden, Colette; Vosman, Ben

2013-01-01

Aphids are insects that cause direct damage to crops by the removal of phloem sap, but more importantly they spread devastating viruses. Aphids use their sophisticated mouthpart (i.e. stylet) to feed from the phloem sieve elements of the host plant. To identify genes that affect host plant resistance to aphids, we previously screened an Arabidopsis thaliana activation tag mutant collection. In such mutants, tagged genes are overexpressed by a strong 35S enhancer adjacent to the natural promoter, resulting in a dominant gain-of-function phenotype. We previously identified several of these mutants on which the aphid Myzus persicae showed a reduced population development compared with wild type. In the present study we show that the gene responsible for the phenotype of one of the mutants is At5g65040 and named this gene Increased Resistance to Myzus persicae 1 (IRM1). Overexpression of the cloned IRM1 gene conferred a phenotype identical to that of the original mutant. Conversely, an IRM1 knockout mutant promoted aphid population development compared to the wild type. We performed Electrical Penetration Graph analysis to investigate how probing and feeding behaviour of aphids was affected on plants that either overexpressed IRM1 or contained a knockout mutation in this gene. The EPG results indicated that the aphids encounter resistance factors while reaching for the phloem on the overexpressing line. This resistance mechanism also affected other aphid species and is suggested to be of mechanical nature. Interestingly, genetic variation for IRM1 expression in response to aphid attack was observed. Upon aphid attack the expression of IRM1 was initially (after 6 hours) induced in ecotype Wassilewskija followed by suppression. In Columbia-0, IRM1 expression was already suppressed six hours after the start of the infestation. The resistance conferred by the overexpression of IRM1 in A. thaliana trades off with plant growth. PMID:23951039

Thermodynamics of Pb(ii) and Zn(ii) binding to MT-3, a neurologically important metallothionein.

PubMed

Carpenter, M C; Shami Shah, A; DeSilva, S; Gleaton, A; Su, A; Goundie, B; Croteau, M L; Stevenson, M J; Wilcox, D E; Austin, R N

2016-06-01

Isothermal titration calorimetry (ITC) was used to quantify the thermodynamics of Pb(2+) and Zn(2+) binding to metallothionein-3 (MT-3). Pb(2+) binds to zinc-replete Zn7MT-3 displacing each zinc ion with a similar change in free energy (ΔG) and enthalpy (ΔH). EDTA chelation measurements of Zn7MT-3 and Pb7MT-3 reveal that both metal ions are extracted in a tri-phasic process, indicating that they bind to the protein in three populations with different binding thermodynamics. Metal binding is entropically favoured, with an enthalpic penalty that reflects the enthalpic cost of cysteine deprotonation accompanying thiolate ligation of the metal ions. These data indicate that Pb(2+) binding to both apo MT-3 and Zn7MT-3 is thermodynamically favourable, and implicate MT-3 in neuronal lead biochemistry.

[Effects of stable ANO1 overexpression on biological behaviors of human laryngeal squamous cell carcinoma Hep-2 cells in vitro].

PubMed

Li, Yadong; Zhang, Jinsong; Yang, Kai; Zhang, Fujun; Chen, Rui; Chen, Dan

2014-02-01

To detect the effects of ANO1 overexpression on the biological behaviors of human laryngeal squamous cell carcinoma Hep-2 cells. A Hep-2 cell line stably overexpressing ANO1 were examined with flow cytometry, soft agar assay, wound healing assay, siRNA experiments, and chloride channel block with DIDS to observe the effect of ANO1 overexpression on the growth, migration and invasion of the cells. Flow cytometry revealed a comparable cell percentage in G0/G1 phase between ANO1-overexpressing cells and the control cells (P>0.05). The two cells showed no significant difference in soft agar assay (P>0.05), but in wound healing experiments, ANO1-overexpressing cells showed significantly accelerated migration (P<0.05), whereas siRNA-mediated silencing of ANO1 significantly inhibited the cell migration (P<0.05). Treatment with DIDS resulted in an effective block of the ANO1 chloride channel activity and obviously decreased the migration speed of Hep-2 cells. ANO1 overexpression does not significantly affect the proliferation of cancer cells, but can enhance the migration ability of head and neck squamous cell carcinoma, suggesting the value of ANO1 as a new gene therapy target for head and neck squamous cell carcinoma.

Overexpression of FOXO4 induces apoptosis of clear-cell renal carcinoma cells through downregulation of Bim.

PubMed

Wang, Wei; Zhou, Pang-Hu; Hu, Wei

2016-03-01

Forkhead box O4 (FOXO4) has been reported to be a novel tumor suppressor gene in gastrointestinal cancers; however, its role in clear‑cell renal carcinoma cells (ccRCC) has remained largely elusive. The present study assessed the expression levels of FOXO4 in RCC tissues and cells. Furthermore, the effects of vector‑mediated overexpression of FOXO4 on the apoptotic rate of the 786‑0 and Caki‑1 cell lines and the role of Bim in this process were investigated. The results demonstrated that the protein and mRNA expression levels of FOXO4 were decreased in renal cancer tissues and cell lines compared with those in normal tissues and cell lines. FOXO4 overexpression significantly increased the apoptotic rate of ccRCC cells in vitro, along with increased protein expression levels of Bim, cleaved‑caspase 3, B‑cell lymphoma 2 (Bcl‑2)‑associated X protein (Bax) and cytochrome c, as well as a decrease in Bcl‑2 expression. Of note, the apoptotic effects of FOXO4 overexpression in 786‑0 cells were inhibited by small interfering RNA‑mediated knockdown of Bim. The results of the present study indicated that FOXO4 has an inhibitory effect in ccRCC, at least in part through inducing apoptosis via upregulation of Bim in the mitochondria-dependent pathway.

Does Variation of the Inter-Domain Linker Sequence Modulate the Metal Binding Behaviour of Helix pomatia Cd-Metallothionein?

PubMed Central

Gil-Moreno, Selene; Jiménez-Martí, Elena; Palacios, Òscar; Zerbe, Oliver; Dallinger, Reinhard; Capdevila, Mercè; Atrian, Sílvia

2015-01-01

Snail metallothioneins (MTs) constitute an ideal model to study structure/function relationships in these metal-binding polypeptides. Helix pomatia harbours three MT isoforms: the highly specific CdMT and CuMT, and an unspecific Cd/CuMT, which represent paralogous proteins with extremely different metal binding preferences while sharing high sequence similarity. Preceding work allowed assessing that, although, the Cys residues are responsible for metal ion coordination, metal specificity or preference is achieved by diversification of the amino acids interspersed between them. The metal-specific MT polypeptides fold into unique, energetically-optimized complexes of defined metal content, when binding their cognate metal ions, while they produce a mixture of complexes, none of them representing a clear energy minimum, with non-cognate metal ions. Another critical, and so far mostly unexplored, region is the stretch linking the individual MT domains, each of which represents an independent metal cluster. In this work, we have designed and analyzed two HpCdMT constructs with substituted linker segments, and determined their coordination behavior when exposed to both cognate and non-cognate metal ions. Results unequivocally show that neither length nor composition of the inter-domain linker alter the features of the Zn(II)- and Cd(II)-complexes, but surprisingly that they influence their ability to bind Cu(I), the non-cognate metal ion. PMID:26703589

Muscle fiber-type conversion in the transgenic pigs with overexpression of PGC1α gene in muscle.

PubMed

Ying, Fei; Zhang, Liang; Bu, Guowei; Xiong, Yuanzhu; Zuo, Bo

2016-11-25

The peroxisome proliferator-activated receptor gamma, co-activator 1 alpha(PGC1α) effectively induced the biosynthesis of the mitochondria and the energy metabolism, and also regulated the muscle fiber-type shift. Overexpression of PGC1α gene in mice led to higher oxidative muscle fiber composition in muscle. However, no researches about the significant differences of muscle fiber phenotype in pigs after PGC1α overexpression had been reported. The composition of muscle fiber-types which were distinguished by four myosin heavy chain(MYHC) isoforms, can significantly affect the muscle functions. In our study, we generated the transgenic pigs to investigate the effect of overexpression of PGC1α gene on muscle fiber-type conversion. The results showed that the number of oxidative muscle fiber(type1 muscle fiber) was increased and the number of glycolytic muscle fiber(type2b muscle fiber) was decreased in the transgenic pigs. Furthermore, we found that PGC1α overexpression up-regulated the expression of MYHC1 and MYHC2a and down-regulated the expression of MYHC2b.The analysis of genes expression demonstrated the main differentially expressed genes were MSTN, Myog and FOXO1. In conclusion, the overexpression of PGC1α gene can promote the glycolytic muscle fiber transform to the oxidative muscle fiber in pigs. Copyright © 2016 Elsevier Inc. All rights reserved.

Muscle fiber-type conversion in the transgenic pigs with overexpression of PGC1α gene in muscle

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

Ying, Fei; Zhang, Liang; Bu, Guowei

The peroxisome proliferator-activated receptor gamma, co-activator 1 alpha(PGC1α) effectively induced the biosynthesis of the mitochondria and the energy metabolism, and also regulated the muscle fiber-type shift. Overexpression of PGC1α gene in mice led to higher oxidative muscle fiber composition in muscle. However, no researches about the significant differences of muscle fiber phenotype in pigs after PGC1α overexpression had been reported. The composition of muscle fiber-types which were distinguished by four myosin heavy chain(MYHC) isoforms, can significantly affect the muscle functions. In our study, we generated the transgenic pigs to investigate the effect of overexpression of PGC1α gene on muscle fiber-typemore » conversion. The results showed that the number of oxidative muscle fiber(type1 muscle fiber) was increased and the number of glycolytic muscle fiber(type2b muscle fiber) was decreased in the transgenic pigs. Furthermore, we found that PGC1α overexpression up-regulated the expression of MYHC1 and MYHC2a and down-regulated the expression of MYHC2b.The analysis of genes expression demonstrated the main differentially expressed genes were MSTN, Myog and FOXO1. In conclusion, the overexpression of PGC1α gene can promote the glycolytic muscle fiber transform to the oxidative muscle fiber in pigs.« less

Over-expression of Trxo1 increases the viability of tobacco BY-2 cells under H2O2 treatment

PubMed Central

Ortiz-Espín, Ana; Locato, Vittoria; Camejo, Daymi; Schiermeyer, Andreas; De Gara, Laura; Sevilla, Francisca; Jiménez, Ana

2015-01-01

Background and Aims Reactive oxygen species (ROS), especially hydrogen peroxide, play a critical role in the regulation of plant development and in the induction of plant defence responses during stress adaptation, as well as in plant cell death. The antioxidant system is responsible for controlling ROS levels in these processes but redox homeostasis is also a key factor in plant cell metabolism under normal and stress situations. Thioredoxins (Trxs) are ubiquitous small proteins found in different cell compartments, including mitochondria and nuclei (Trxo1), and are involved in the regulation of target proteins through reduction of disulphide bonds, although their role under oxidative stress has been less well studied. This study describes over-expression of a Trxo1 for the first time, using a cell-culture model subjected to an oxidative treatment provoked by H2O2. Methods Control and over-expressing PsTrxo1 tobacco (Nicotiana tabacum) BY-2 cells were treated with 35 mm H2O2 and the effects were analysed by studying the growth dynamics of the cultures together with oxidative stress parameters, as well as several components of the antioxidant systems involved in the metabolism of H2O2. Analysis of different hallmarks of programmed cell death was also carried out. Key Results Over-expression of PsTrxo1 caused significant differences in the response of TBY-2 cells to high concentrations of H2O2, namely higher and maintained viability in over-expressing cells, whilst the control line presented a severe decrease in viability and marked indications of oxidative stress, with generalized cell death after 3 d of treatment. In over-expressing cells, an increase in catalase activity, decreases in H2O2 and nitric oxide contents and maintenance of the glutathione redox state were observed. Conclusions A decreased content of endogenous H2O2 may be responsible in part for the delayed cell death found in over-expressing cells, in which changes in oxidative parameters and

Over-expression of Trxo1 increases the viability of tobacco BY-2 cells under H2O2 treatment.

PubMed

Ortiz-Espín, Ana; Locato, Vittoria; Camejo, Daymi; Schiermeyer, Andreas; De Gara, Laura; Sevilla, Francisca; Jiménez, Ana

2015-09-01

Reactive oxygen species (ROS), especially hydrogen peroxide, play a critical role in the regulation of plant development and in the induction of plant defence responses during stress adaptation, as well as in plant cell death. The antioxidant system is responsible for controlling ROS levels in these processes but redox homeostasis is also a key factor in plant cell metabolism under normal and stress situations. Thioredoxins (Trxs) are ubiquitous small proteins found in different cell compartments, including mitochondria and nuclei (Trxo1), and are involved in the regulation of target proteins through reduction of disulphide bonds, although their role under oxidative stress has been less well studied. This study describes over-expression of a Trxo1 for the first time, using a cell-culture model subjected to an oxidative treatment provoked by H2O2. Control and over-expressing PsTrxo1 tobacco (Nicotiana tabacum) BY-2 cells were treated with 35 mm H2O2 and the effects were analysed by studying the growth dynamics of the cultures together with oxidative stress parameters, as well as several components of the antioxidant systems involved in the metabolism of H2O2. Analysis of different hallmarks of programmed cell death was also carried out. Over-expression of PsTrxo1 caused significant differences in the response of TBY-2 cells to high concentrations of H2O2, namely higher and maintained viability in over-expressing cells, whilst the control line presented a severe decrease in viability and marked indications of oxidative stress, with generalized cell death after 3 d of treatment. In over-expressing cells, an increase in catalase activity, decreases in H2O2 and nitric oxide contents and maintenance of the glutathione redox state were observed. A decreased content of endogenous H2O2 may be responsible in part for the delayed cell death found in over-expressing cells, in which changes in oxidative parameters and antioxidants were less extended after the oxidative

c-Myc dependent expression of pro-apoptotic Bim renders HER2-overexpressing breast cancer cells dependent on anti-apoptotic Mcl-1.

PubMed

Campone, Mario; Noël, Bélinda; Couriaud, Cécile; Grau, Morgan; Guillemin, Yannis; Gautier, Fabien; Gouraud, Wilfried; Charbonnel, Catherine; Campion, Loïc; Jézéquel, Pascal; Braun, Frédérique; Barré, Benjamin; Coqueret, Olivier; Barillé-Nion, Sophie; Juin, Philippe

2011-09-07

Anti-apoptotic signals induced downstream of HER2 are known to contribute to the resistance to current treatments of breast cancer cells that overexpress this member of the EGFR family. Whether or not some of these signals are also involved in tumor maintenance by counteracting constitutive death signals is much less understood. To address this, we investigated what role anti- and pro-apoptotic Bcl-2 family members, key regulators of cancer cell survival, might play in the viability of HER2 overexpressing breast cancer cells. We used cell lines as an in vitro model of HER2-overexpressing cells in order to evaluate how anti-apoptotic Bcl-2, Bcl-xL and Mcl-1, and pro-apoptotic Puma and Bim impact on their survival, and to investigate how the constitutive expression of these proteins is regulated. Expression of the proteins of interest was confirmed using lysates from HER2-overexpressing tumors and through analysis of publicly available RNA expression data. We show that the depletion of Mcl-1 is sufficient to induce apoptosis in HER2-overexpressing breast cancer cells. This Mcl-1 dependence is due to Bim expression and it directly results from oncogenic signaling, as depletion of the oncoprotein c-Myc, which occupies regions of the Bim promoter as evaluated in ChIP assays, decreases Bim levels and mitigates Mcl-1 dependence. Consistently, a reduction of c-Myc expression by inhibition of mTORC1 activity abrogates occupancy of the Bim promoter by c-Myc, decreases Bim expression and promotes tolerance to Mcl-1 depletion. Western blot analysis confirms that naïve HER2-overexpressing tumors constitutively express detectable levels of Mcl-1 and Bim, while expression data hint on enrichment for Mcl-1 transcripts in these tumors. This work establishes that, in HER2-overexpressing tumors, it is necessary, and maybe sufficient, to therapeutically impact on the Mcl-1/Bim balance for efficient induction of cancer cell death.

Genetic variation in metallothionein and metal-regulatory transcription factor 1 in relation to urinary cadmium, copper, and zinc

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

Adams, Scott V., E-mail: sadams@fhcrc.org; Barrick, Brian; Christopher, Emily P.

Background: Metallothionein (MT) proteins play critical roles in the physiological handling of both essential (Cu and Zn) and toxic (Cd) metals. MT expression is regulated by metal-regulatory transcription factor 1 (MTF1). Hence, genetic variation in the MT gene family and MTF1 might influence excretion of these metals. Methods: 321 women were recruited in Seattle, WA and Las Cruces, NM and provided demographic information, urine samples for measurement of metal concentrations by mass spectrometry and creatinine, and blood or saliva for extraction of DNA. Forty-one single nucleotide polymorphisms (SNPs) within the MTF1 gene region and the region of chromosome 16 encodingmore » the MT gene family were selected for genotyping in addition to an ancestry informative marker panel. Linear regression was used to estimate the association of SNPs with urinary Cd, Cu, and Zn, adjusted for age, urinary creatinine, smoking history, study site, and ancestry. Results: Minor alleles of rs28366003 and rs10636 near the MT2A gene were associated with lower urinary Cd, Cu, and Zn. Minor alleles of rs8044719 and rs1599823, near MT1A and MT1B, were associated with lower urinary Cd and Zn, respectively. Minor alleles of rs4653329 in MTF1 were associated with lower urinary Cd. Conclusions: These results suggest that genetic variation in the MT gene region and MTF1 influences urinary Cd, Cu, and Zn excretion. - Highlights: • Genetic variation in metallothionein (MT) genes was assessed in two diverse populations. • Single nucleotide polymorphisms (SNPs) in MT genes were associated with mean urinary Cd, Cu and Zn. • Genetic variation may influence biomarkers of exposure, and associations of exposure with health.« less

Expression analysis of metallothioneins and mineral contents in tomato (Lycopersicon esculentum) under heavy metal stress.

PubMed

Kısa, Dursun; Öztürk, Lokman; Doker, Serhat; Gökçe, İsa

2017-04-01

Heavy metals are considered to be the most important pollutants in the contamination of soils; they adversely affect plant growth and development and cause some physiological and molecular changes. The contamination of agricultural soils by heavy metals has changed the mineral element content of vegetables. Plant metallothioneins (MTs) are thought to have the functional role in heavy metal homeostasis, and they are used as the biomarkers for evaluating environmental pollution. We aimed to evaluate the expression of MT isoforms (MT1, 2, 3 and 4) and some mineral element composition of tomato roots, leaves and fruits exposed to copper and lead. Heavy metal applications increased MT1 and MT2 gene expressions compared to the control in the tissues of tomato. The highest level of MT1 and MT2 transcripts was found in roots and leaves, respectively. The expression of MT3 is induced in roots, leaves and fruits except for Pb treatment in roots. MT4 expression increased in fruits; however, other tissues did not show a clear change. Our results indicated that Cu content was higher than Pb in all tissues of tomato. The lower doses of Cu (10 ppm) increased the content of Mg, Fe, Ca and Mn in roots. Pb generally increased the level of minerals in leaves and fruits, but it decreased Mg, Mn and Fe contents in roots. Both heavy metals not only moved to aerial parts but also caused alterations to mineral element levels. These results show that MT transcripts are regulated by Cu and Pb, and expression pattern changes to MT isoforms and tissue types. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Examining the specific contributions of individual Arabidopsis metallothioneins to copper distribution and metal tolerance.

PubMed

Guo, Woei-Jiun; Meetam, Metha; Goldsbrough, Peter B

2008-04-01

Metallothioneins (MTs) are small cysteine-rich proteins found in various eukaryotes. Plant MTs are classified into four types based on the arrangement of cysteine residues. To determine whether all four types of plant MTs function as metal chelators, six Arabidopsis (Arabidopsis thaliana) MTs (MT1a, MT2a, MT2b, MT3, MT4a, and MT4b) were expressed in the copper (Cu)- and zinc (Zn)-sensitive yeast mutants, Deltacup1 and Deltazrc1 Deltacot1, respectively. All four types of Arabidopsis MTs provided similar levels of Cu tolerance and accumulation to the Deltacup1 mutant. The type-4 MTs (MT4a and MT4b) conferred greater Zn tolerance and higher accumulation of Zn than other MTs to the Deltazrc1 Deltacot1 mutant. To examine the functions of MTs in plants, we studied Arabidopsis plants that lack MT1a and MT2b, two MTs that are expressed in phloem. The lack of MT1a, but not MT2b, led to a 30% decrease in Cu accumulation in roots of plants exposed to 30 mum CuSO(4). Ectopic expression of MT1a RNA in the mt1a-2 mt2b-1 mutant restored Cu accumulation in roots. The mt1a-2 mt2b-1 mutant had normal metal tolerance. However, when MT deficiency was combined with phytochelatin deficiency, growth of the mt1a-2 mt2b-1 cad1-3 triple mutant was more sensitive to Cu and cadmium compared to the cad1-3 mutant. Together these results provide direct evidence for functional contributions of MTs to plant metal homeostasis. MT1a, in particular, plays a role in Cu homeostasis in the roots under elevated Cu. Moreover, MTs and phytochelatins function cooperatively to protect plants from Cu and cadmium toxicity.

Inhibition of connective tissue growth factor overexpression decreases growth of hepatocellular carcinoma cells in vitro and in vivo.

PubMed

Jia, Xiao-Qin; Cheng, Hai-Qing; Li, Hong; Zhu, Yan; Li, Yu-Hua; Feng, Zhen-Qing; Zhang, Jian-Ping

2011-11-01

We have previously found that connective tissue growth factor (CTGF) is highly expressed in a rat model of liver cancer. Here, we examined expression of CTGF in human hepatocellular carcinoma (HCC) cells and its effect on cell growth. Real-time PCR was used to observe expression of CTGF in human HCC cell lines HepG2, SMMC-7721, MHCC-97H and LO2. siRNA for the CTGF gene was designed, synthesized and cloned into a Plk0.1-GFP-SP6 vector to construct a lentivirus-mediated shRNA/CTGF. CTGF mRNA and protein expression in HepG2 cells treated by CTGF-specific shRNA was evaluated by real-time PCR and Western blotting. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was utilized to evaluate the growth effect, and a colony formation assay was used for observing clonogenic growth. In vivo, tumor cell proliferation was evaluated in a nude mouse model of xenotransplantation. Statistical significance was determined by t test for comparison between two groups, or analysis of variance (ANOVA) for multiple groups. Immunohistochemical staining of CTGF was seen in 35 of 40 HCC samples (87.5%). CTGF was overexpressed 5-fold in 20 HCC tissues, compared with surrounding non-tumor liver tissue. CTGF mRNA level was 5 - 8-fold higher in HepG2, SMMC-7721 and MHCC-97H than in LO2 cells. This indicated that the inhibition rate of cell growth was 43% after knockdown of CTGF expression (P < 0.05). Soft agar colony formation assay showed that siRNA mediated knockdown of CTGF inhibited colony formation in soft agar of HepG2 cells (P < 0.05). The volume of tumors from CTGF-shRNA-expressing cells only accounted for 35% of the tumors from the scrambled control-infected HepG2 cells (P < 0.05). CTGF was overexpressed in human HCC cells and downregulation of CTGF inhibited HCC growth in vitro and in vivo. Knockdown of CTGF may be a potential therapeutic strategy for treatment of HCC.

Enhanced leavening ability of baker's yeast by overexpression of SNR84 with PGM2 deletion.

PubMed

Lin, Xue; Zhang, Cui-Ying; Bai, Xiao-Wen; Xiao, Dong-Guang

2015-06-01

Dough-leavening ability is one of the main aspects considered when selecting a baker's yeast strain for baking industry. Generally, modification of maltose metabolic pathway and known regulatory networks of maltose metabolism were used to increase maltose metabolism to improve leavening ability in lean dough. In this study, we focus on the effects of PGM2 (encoding for the phosphoglucomutase) and SNR84 (encoding for the H/ACA snoRNA) that are not directly related to both the maltose metabolic pathway and known regulatory networks of maltose metabolism on the leavening ability of baker's yeast in lean dough. The results show that the modifications on PGM2 and/or SNR84 are effective ways in improving leavening ability of baker's yeast in lean dough. Deletion of PGM2 decreased cellular glucose-1-phosphate and overexpression of SNR84 increased the maltose permease activity. These changes resulted in 11, 19 and 21% increases of the leavening ability for PGM2 deletion, SNR84 overexpression and SNR84 overexpression combining deleted PGM2, respectively.

Parkin Mutations Reduce the Complexity of Neuronal Processes in iPSC-derived Human Neurons

PubMed Central

Ren, Yong; Jiang, Houbo; Hu, Zhixing; Fan, Kevin; Wang, Jun; Janoschka, Stephen; Wang, Xiaomin; Ge, Shaoyu; Feng, Jian

2015-01-01

Parkinson’s disease (PD) is characterized by the degeneration of nigral dopaminergic (DA) neurons and non-DA neurons in many parts of the brain. Mutations of parkin, an E3 ubiquitin ligase that strongly binds to microtubules, are the most frequent cause of recessively inherited Parkinson’s disease. The lack of robust PD phenotype in parkin knockout mice suggests a unique vulnerability of human neurons to parkin mutations. Here, we show that the complexity of neuronal processes as measured by total neurite length, number of terminals, number of branch points and Sholl analysis, was greatly reduced in induced pluripotent stem cell (iPSC)-derived TH+ or TH− neurons from PD patients with parkin mutations. Consistent with these, microtubule stability was significantly decreased by parkin mutations in iPSC-derived neurons. Overexpression of parkin, but not its PD-linked mutant nor GFP, restored the complexity of neuronal processes and the stability of microtubules. Consistent with these, the microtubule-depolymerizing agent colchicine mimicked the effect of parkin mutations by decreasing neurite length and complexity in control neurons while the microtubule-stabilizing drug taxol mimicked the effect of parkin overexpression by enhancing the morphology of parkin-deficient neurons. The results suggest that parkin maintains the morphological complexity of human neurons by stabilizing microtubules. PMID:25332110

Metallothionein-Like Proteins and Energy Reserve Levels after Ni and Pb Exposure in the Pacific White Prawn Penaeus vannamei

PubMed Central

Nunez-Nogueira, Gabriel; Mouneyrac, Catherine; Muntz, Alice; Fernandez-Bringas, Laura

2010-01-01

This study analyzed the changes in metallothionein-like proteins (MTLPs) and Energy Reserves (ERs) in hepatopancreas and abdominal muscle of the white prawn Penaeus vannamei. Realistic metal concentration exposure for 10 days to Ni and Pb in solution revealed that juvenile prawns partially induce MTLP in hepatopancreas after Pb exposure. Ni was distributed equally between soluble and insoluble fractions, while Pb was present only in the insoluble fraction, suggesting different detoxification strategy. No changes in lipids and glycogen concentration were detected under these experimental conditions in both tissues analyzed. MTLP could not be considered as a suitable indicator for lead exposure in hepatopancreas. PMID:20862200

Transgenic overexpression of uncoupling protein 2 attenuates salt-induced vascular dysfunction by inhibition of oxidative stress.

PubMed

Ma, Shuangtao; Wang, Qiang; Zhang, Yan; Yang, Dachun; Li, De; Tang, Bing; Yang, Yongjian

2014-03-01

Ablation of uncoupling protein 2 (UCP2) has been involved in the enhancement of salt sensitivity associated with increased superoxide level and decreased nitric oxide (NO) bioavailability. However, the role of overexpression of UCP2 in salt-induced vascular dysfunction remains elusive. UCP2 transgenic (TG) and wild-type (WT) mice were placed on either a normal-salt (NS, 0.5%) or a high-salt (HS, 8%) diet for 12 weeks. Blood pressure (BP) and hypotensive responses were measured, and the vascular tone, superoxide level, and NO bioavailability in aortas were measured in each group. The TG mice had increased expression and function of UCP2 in vascular smooth muscle cells. The acetylcholine (ACh)- and nitroglycerin (NTG)-induced hypotensive responses and aortic relaxations were significantly blunted in WT mice fed with an HS diet compared with an NS diet. These harmful effects were prevented in UCP2 TG mice. The impairments of ACh- and NTG-induced relaxation in aorta were inhibited by the endothelial NO synthase (eNOS) inhibitor L-NAME and mitochondrial antioxidant MitoQ, respectively. The HS intake led to a significant increase in superoxide production and a comparable decrease in NO bioavailability in aortas, and these effects were blunted in UCP2 TG mice. The expression of UCP2 was slightly increased in the HS group. However, the expression and phosphorylation of eNOS were not affected by an HS diet and overexpression of UCP2. These findings suggest that overexpression of UCP2 can ameliorate salt-induced vascular dysfunction. This beneficial effect of UCP2 is mediated by decreased superoxide and reserved NO bioavailability.

Single-cell RNA sequencing reveals metallothionein heterogeneity during hESC differentiation to definitive endoderm.

PubMed

Lu, Junjie; Baccei, Anna; Lummertz da Rocha, Edroaldo; Guillermier, Christelle; McManus, Sean; Finney, Lydia A; Zhang, Cheng; Steinhauser, Matthew L; Li, Hu; Lerou, Paul H

2018-04-01

Differentiation of human pluripotent stem cells towards definitive endoderm (DE) is the critical first step for generating cells comprising organs such as the gut, liver, pancreas and lung. This in-vitro differentiation process generates a heterogeneous population with a proportion of cells failing to differentiate properly and maintaining expression of pluripotency factors such as Oct4. RNA sequencing of single cells collected at four time points during a 4-day DE differentiation identified high expression of metallothionein genes in the residual Oct4-positive cells that failed to differentiate to DE. Using X-ray fluorescence microscopy and multi-isotope mass spectrometry, we discovered that high intracellular zinc level corresponds with persistent Oct4 expression and failure to differentiate. This study improves our understanding of the cellular heterogeneity during in-vitro directed differentiation and provides a valuable resource to improve DE differentiation efficiency. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Potent hydroxyl radical-scavenging activity of drought-induced type-2 metallothionein in wild watermelon.

PubMed

Akashi, Kinya; Nishimura, Noriyuki; Ishida, Yoshinori; Yokota, Akiho

2004-10-08

Wild watermelon (Citrullus lanatus sp.) has the ability to tolerate severe drought/high light stress conditions despite carrying out normal C3-type photosynthesis. Here, mRNA differential display was employed to isolate drought-responsive genes in the leaves of wild watermelon. One of the isolated genes, CLMT2, shared significant homology with type-2 metallothionein (MT) sequences from other plants. The second-order rate constant for the reaction between a recombinant CLMT2 protein and hydroxyl radicals was estimated to be 1.2 x 10(11) M(-1) s(-1), demonstrating that CLMT2 had an extraordinary high activity for detoxifying hydroxyl radicals. Moreover, hydroxyl radical-catalyzed degradation of watermelon genomic DNA was effectively suppressed by CLMT2 in vitro. This is the first demonstration of a plant MT with antioxidant properties. The results suggest that CLMT2 induction contributes to the survival of wild watermelon under severe drought/high light stress conditions. Copyright 2004 Elsevier Inc.

Effects of camptothecin or TOP1 overexpression on genetic stability in Saccharomyces cerevisiae.

PubMed

Sloan, Roketa; Huang, Shar-Yin Naomi; Pommier, Yves; Jinks-Robertson, Sue

2017-11-01

Topoisomerase I (Top1) removes DNA torsional stress by nicking and resealing one strand of DNA, and is essential in higher eukaryotes. The enzyme is frequently overproduced in tumors and is the sole target of the chemotherapeutic drug camptothecin (CPT) and its clinical derivatives. CPT stabilizes the covalent Top1-DNA cleavage intermediate, which leads to toxic double-strand breaks (DSBs) when encountered by a replication fork. In the current study, we examined genetic instability associated with CPT treatment or with Top1 overexpression in the yeast Saccharomyces cerevisiae. Two types of instability were monitored: Top1-dependent deletions in haploid strains, which do not require processing into a DSB, and instability at the repetitive ribosomal DNA (rDNA) locus in diploid strains, which reflects DSB formation. Three 2-bp deletion hotspots were examined and mutations at each were elevated either when a wild-type strain was treated with CPT or when TOP1 was overexpressed, with the mutation frequency correlating with the level of TOP1 overexpression. Under both conditions, deletions at novel positions were enriched. rDNA stability was examined by measuring loss-of-heterozygosity and as was observed previously upon CPT treatment of a wild-type strain, Top1 overexpression destabilized rDNA. We conclude that too much, as well as too little of Top1 is detrimental to eukaryotic genomes, and that CPT has destabilizing effects that extend beyond those associated with DSB formation. Copyright © 2017 Elsevier B.V. All rights reserved.

Overexpression of SARAF Ameliorates Pressure Overload-Induced Cardiac Hypertrophy Through Suppressing STIM1-Orai1 in Mice.

PubMed

Dai, Fengdan; Zhang, Yan; Wang, Qiang; Li, De; Yang, Yongjian; Ma, Shuangtao; Yang, Dachun

2018-01-01

Activation of stromal interaction molecule 1 (STIM1) and Orai1 participates in the development of cardiac hypertrophy. Store-operated Ca2+ entry-associated regulatory factor (SARAF) is an intrinsic inhibitor of STIM1-Orai1 interaction. Thus, we hypothesized that SARAF could prevent cardiac hypertrophy. Male C57BL/6 mice, aged 8 weeks, were randomly divided into sham and abdominal aortic constriction surgery groups and were infected with lentiviruses expressing SARAF and GFP (Lenti-SARAF) or GFP alone (Lenti-GFP) via intramyocardial injection. At 4 weeks after aortic constriction, left ventricular structure and function were assessed by echocardiography and hemodynamic assays. The gene and protein expressions of SARAF, STIM1, and Orai1 were measured by quantitative PCR and Western blot, respectively. Gene and protein expressions of SARAF were significantly decreased, while STIM1 and Orai1 were increased in the heart tissue compared with sham group. Overexpression of SARAF in the heart prevented the upregulation of STIM1 and Orai1, and importantly, attenuated aortic constriction-induced decrease in maximal rate of left ventricular pressure decay and increases in thickness of interventricular septum and left ventricular posterior wall, heart weight/body weight ratio, and size of cardiomyocytes. Blood pressure detected through the carotid artery and left ventricular systolic function were not affected by SARAF overexpression. In addition, overexpression of SARAF also attenuated angiotensin II-induced upregulation of STIM1 and Orai1 and hypertrophy of cultured cardiomyocytes. Overexpression of SARAF in the heart prevents cardiac hypertrophy, probably through suppressing the upregulation of STIM1/Orai1. © 2018 The Author(s). Published by S. Karger AG, Basel.

Muscle uncoupling protein 3 overexpression mimics endurance training and reduces circulating biomarkers of incomplete β-oxidation

PubMed Central

Aguer, Céline; Fiehn, Oliver; Seifert, Erin L.; Bézaire, Véronic; Meissen, John K.; Daniels, Amanda; Scott, Kyle; Renaud, Jean-Marc; Padilla, Marta; Bickel, David R.; Dysart, Michael; Adams, Sean H.; Harper, Mary-Ellen

2013-01-01

Exercise substantially improves metabolic health, making the elicited mechanisms important targets for novel therapeutic strategies. Uncoupling protein 3 (UCP3) is a mitochondrial inner membrane protein highly selectively expressed in skeletal muscle. Here we report that moderate UCP3 overexpression (roughly 3-fold) in muscles of UCP3 transgenic (UCP3 Tg) mice acts as an exercise mimetic in many ways. UCP3 overexpression increased spontaneous activity (∼40%) and energy expenditure (∼5–10%) and decreased oxidative stress (∼15–20%), similar to exercise training in wild-type (WT) mice. The increase in complete fatty acid oxidation (FAO; ∼30% for WT and ∼70% for UCP3 Tg) and energy expenditure (∼8% for WT and 15% for UCP3 Tg) in response to endurance training was higher in UCP3 Tg than in WT mice, showing an additive effect of UCP3 and endurance training on these two parameters. Moreover, increases in circulating short-chain acylcarnitines in response to acute exercise in untrained WT mice were absent with training or in UCP3 Tg mice. UCP3 overexpression had the same effect as training in decreasing long-chain acylcarnitines. Outcomes coincided with a reduction in muscle carnitine acetyltransferase activity that catalyzes the formation of acylcarnitines. Overall, results are consistent with the conclusions that circulating acylcarnitines could be used as a marker of incomplete muscle FAO and that UCP3 is a potential target for the treatment of prevalent metabolic diseases in which muscle FAO is affected.—Aguer, C., Fiehn, O., Seifert, E. L., Bézaire, V., Meissen, J. K., Daniels, A., Scott, K., Renaud, J.-M., Padilla, M., Bickel, D. R., Dysart, M., Adams, S. H., Harper, M.-E. Muscle uncoupling protein 3 overexpression mimics endurance training and reduces circulating biomarkers of incomplete β-oxidation. PMID:23825224

Metallothionein-like multinuclear clusters of mercury(II) and sulfur in peat

USGS Publications Warehouse

Nagy, K.L.; Manceau, A.; Gasper, J.D.; Ryan, J.N.; Aiken, G.R.

2011-01-01

Strong mercury(II)-sulfur (Hg-SR) bonds in natural organic matter, which influence mercury bioavailability, are difficult to characterize. We report evidence for two new Hg-SR structures using X-ray absorption spectroscopy in peats from the Florida Everglades with added Hg. The first, observed at a mole ratio of organic reduced S to Hg (Sred/Hg) between 220 and 1140, is a Hg4Sx type of cluster with each Hg atom bonded to two S atoms at 2.34 ?? and one S at 2.53 ??, and all Hg atoms 4.12 ?? apart. This model structure matches those of metal-thiolate clusters in metallothioneins, but not those of HgS minerals. The second, with one S atom at 2.34 ?? and about six C atoms at 2.97 to 3.28 ??, occurred at S red/Hg between 0.80 and 4.3 and suggests Hg binding to a thiolated aromatic unit. The multinuclear Hg cluster indicates a strong binding environment to cysteinyl sulfur that might impede methylation. Along with a linear Hg(SR)2 unit with Hg - S bond lengths of 2.34 ?? at Sred/Hg of about 10 to 20, the new structures support a continuum in Hg-SR binding strength in natural organic matter. ?? 2011 American Chemical Society.

Overexpression of Polysialylated Neural Cell Adhesion Molecule Improves the Migration Capacity of Induced Pluripotent Stem Cell-Derived Oligodendrocyte Precursors

PubMed Central

Czepiel, Marcin; Leicher, Lasse; Becker, Katja; Boddeke, Erik

2014-01-01

Cell replacement therapy aiming at the compensation of lost oligodendrocytes and restoration of myelination in acquired or congenital demyelination disorders has gained considerable interest since the discovery of induced pluripotent stem cells (iPSCs). Patient-derived iPSCs provide an inexhaustible source for transplantable autologous oligodendrocyte precursors (OPCs). The first transplantation studies in animal models for demyelination with iPSC-derived OPCs demonstrated their survival and remyelinating capacity, but also revealed their limited migration capacity. In the present study, we induced overexpression of the polysialylating enzyme sialyltransferase X (STX) in iPSC-derived OPCs to stimulate the production of polysialic acid-neuronal cell adhesion molecules (PSA-NCAMs), known to promote and facilitate the migration of OPCs. The STX-overexpressing iPSC-derived OPCs showed a normal differentiation and maturation pattern and were able to downregulate PSA-NCAMs when they became myelin-forming oligodendrocytes. After implantation in the demyelinated corpus callosum of cuprizone-fed mice, STX-expressing iPSC-derived OPCs demonstrated a significant increase in migration along the axons. Our findings suggest that the reach and efficacy of iPSC-derived OPC transplantation can be improved by stimulating the OPC migration potential via specific gene modulation. PMID:25069776

Anti-cell death engineering of CHO cells: co-overexpression of Bcl-2 for apoptosis inhibition, Beclin-1 for autophagy induction.

PubMed

Lee, Jae Seong; Ha, Tae Kwang; Park, Jin Hyoung; Lee, Gyun Min

2013-08-01

Genetic engineering approaches to inhibit cell death in Chinese hamster ovary (CHO) cell cultures have been limited primarily to anti-apoptosis engineering. Recently, autophagy has received attention as a new anti-cell death engineering target in addition to apoptosis. In order to achieve a more efficient protection of cells from the stressful culture conditions, the simultaneous targeting of anti-apoptosis and pro-autophagy in CHO cells (DG44) was attempted by co-overexpressing an anti-apoptotic protein, Bcl-2, and a key regulator of autophagy pathway, Beclin-1, respectively. Co-overexpression of Bcl-2 and Beclin-1 exhibited a longer culture period as well as higher viability during serum-free suspension culture, compared with the control (without co-overexpression of Bcl-2 and Beclin-1) and Bcl-2 overexpression only. In addition to the efficient inhibition of apoptosis by Bcl-2 overexpression, Beclin-1 overexpression successfully induced the increase in the autophagic marker protein, LC3-II, and autophagosome formation with the decrease in mTOR activity. Co-immunoprecipitation and qRT-PCR experiments revealed that the enforced expression of Beclin-1 increased Ulk1 expression and level of free-Beclin-1 that did not bind to the Bcl-2 despite the Bcl-2 overexpression. Under other stressful culture conditions such as treatment with sodium butyrate and hyperosmolality, co-overexpression of Bcl-2 and Beclin-1 also protected the cells from cell death more efficiently than Bcl-2 overexpression only, implying the potential of autophagy induction. Taken together, the data obtained here provide the evidence that pro-autophagy engineering together with anti-apoptosis engineering yields a synergistic effect and successfully enhances the anti-cell death engineering of CHO cells. Copyright © 2013 Wiley Periodicals, Inc.

Overexpression of an Arabidopsis heterogeneous nuclear ribonucleoprotein gene, AtRNP1, affects plant growth and reduces plant tolerance to drought and salt stresses

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

Wang, Zhenyu, E-mail: wzy72609@163.com; Zhao, Xiuyang, E-mail: xiuzh@psb.vib-ugent.be; Wang, Bing, E-mail: wangbing@ibcas.ac.cn

Heterogeneous nuclear ribonucleoproteins (hnRNPs) participate in diverse regulations of plant growth and environmental stress responses. In this work, an Arabidopsis hnRNP of unknown function, AtRNP1, was investigated. We found that AtRNP1 gene is highly expressed in rosette and cauline leaves, and slightly induced under drought, salt, osmotic and ABA stresses. AtRNP1 protein is localized to both the nucleus and cytoplasm. We performed homologous overexpression of AtRNP1 and found that the transgenic plants showed shortened root length and plant height, and accelerated flowering. In addition, the transgenic plants also showed reduced tolerance to drought, salt, osmotic and ABA stresses. Further studiesmore » revealed that under both normal and stress conditions, the proline contents in the transgenic plants are markedly decreased, associated with reduced expression levels of a proline synthase gene and several stress-responsive genes. These results suggested that the overexpression of AtRNP1 negatively affects plant growth and abiotic stress tolerance. - Highlights: • AtRNP1 is a widely expressed gene and its expression is slightly induced under abiotic stresses. • AtRNP1 protein is localized to both the nucleus and cytoplasm. • Overexpression of AtRNP1 affects plant growth. • Overexpression of AtRNP1 reduces plant tolerance to drought and salt stresses. • AtRNP1 overexpression plants show decreased proline accumulation and stress-responsive gene expressions.« less

Increased α-tocotrienol content in seeds of transgenic rice overexpressing Arabidopsis γ-tocopherol methyltransferase.

PubMed

Zhang, Gui-Yun; Liu, Ru-Ru; Xu, Geng; Zhang, Peng; Li, Yin; Tang, Ke-Xuan; Liang, Guo-Hua; Liu, Qiao-Quan

2013-02-01

Vitamin E comprises a group of eight lipid soluble antioxidant compounds that are an essential part of the human diet. The α-isomers of both tocopherol and tocotrienol are generally considered to have the highest antioxidant activities. γ-tocopherol methyltransferase (γ-TMT) catalyzes the final step in vitamin E biosynthesis, the methylation of γ- and δ-isomers to α- and β-isomers. In present study, the Arabidopsis γ-TMT (AtTMT) cDNA was overexpressed constitutively or in the endosperm of the elite japonica rice cultivar Wuyujing 3 (WY3) by Agrobacterium-mediated transformation. HPLC analysis showed that, in brown rice of the wild type or transgenic controls with empty vector, the α-/γ-tocotrienol ratio was only 0.7, much lower than that for tocopherol (~19.0). In transgenic rice overexpressing AtTMT driven by the constitutive Ubi promoter, most of the γ-isomers were converted to α-isomers, especially the γ- and δ-tocotrienol levels were dramatically decreased. As a result, the α-tocotrienol content was greatly increased in the transgenic seeds. Similarly, over-expression of AtTMT in the endosperm also resulted in an increase in the α-tocotrienol content. The results showed that the α-/γ-tocopherol ratio also increased in the transgenic seeds, but there was no significant effect on α-tocopherol level, which may reflect the fact that γ-tocopherol is present in very small amounts in wild type rice seeds. AtTMT overexpression had no effect on the absolute total content of either tocopherols or tocotrienols. Taken together, these results are the first demonstration that the overexpression of a foreign γ-TMT significantly shift the tocotrienol synthesis in rice, which is one of the world's most important food crops.

TRIM29 Overexpression Promotes Proliferation and Survival of Bladder Cancer Cells through NF-κB Signaling.

PubMed

Tan, Shu-Tao; Liu, Sheng-Ye; Wu, Bin

2016-10-01

TRIM29 overexpression has been reported in several human malignancies and showed correlation with cancer cell malignancy. The aim of the current study is to examine its clinical significance and biological roles in human bladder cancer tissues and cell lines. A total of 102 cases of bladder cancer tissues were examined for TRIM29 expression by immunohistochemistry. siRNA and plasmid transfection were performed in 5637 and BIU-87 cell lines. Cell Counting Kit-8, flow cytometry, western blot, and real-time polymerase chain reaction were performed to examine its biological roles and mechanism in bladder cancer cells. We found that TRIM29 overexpression showed correlation with invading depth (p=0.0087). Knockdown of TRIM29 expression in bladder cancer cell line 5637 inhibited cell growth rate and cell cycle transition while its overexpression in BIU-87 cells accelerated cell proliferation and cell cycle progression. TRIM29 overexpression also inhibited cell apoptosis induced by cisplatin. In addition, we demonstrated that TRIM29 depletion decreased while its overexpression led to upregulated expression of cyclin D1, cyclin E, and Bcl-2. We also showed that TRIM29 knockdown inhibited protein kinase C (PKC) and nuclear factor κB (NF-κB) signaling while its overexpression stimulated the PKC and NF-κB pathways. BAY 11-7082 (NF-κB inhibitor) partly attenuated the effect of TRIM29 on expression of cyclin and Bcl-2. Treatment with PKC inhibitor staurosporine resulted in ameliorated TRIM29 induced activation of NF-κB. The current study demonstrated that TRIM29 upregulates cyclin and Bcl family proteins level to facilitate malignant cell growth and inhibit drug-induced apoptosis in bladder cancer, possibly through PKC-NF-κB signaling pathways.

Overexpression of connexin 43 reduces melanoma proliferative and metastatic capacity

PubMed Central

Tittarelli, A; Guerrero, I; Tempio, F; Gleisner, M A; Avalos, I; Sabanegh, S; Ortíz, C; Michea, L; López, M N; Mendoza-Naranjo, A; Salazar-Onfray, F

2015-01-01

Background: Alterations in connexin 43 (Cx43) expression and/or gap junction (GJ)-mediated intercellular communication are implicated in cancer pathogenesis. Herein, we have investigated the role of Cx43 in melanoma cell proliferation and apoptosis sensitivity in vitro, as well as metastatic capability and tumour growth in vivo. Methods: Connexin 43 expression levels, GJ coupling and proliferation rates were analysed in four different human melanoma cell lines. Furthermore, tumour growth and lung metastasis of high compared with low Cx43-expressing FMS cells were evaluated in vivo using a melanoma xenograft model. Results: Specific inhibition of Cx43 channel activity accelerated melanoma cell proliferation, whereas overexpression of Cx43 increased GJ coupling and reduced cell growth. Moreover, Cx43 overexpression in FMS cells increased basal and tumour necrosis factor-α-induced apoptosis and resulted in decreased melanoma tumour growth and lower number and size of metastatic foci in vivo. Conclusions: Our findings reveal an important role for Cx43 in intrinsically controlling melanoma growth, death and metastasis, and emphasise the potential use of compounds that selectively enhance Cx43 expression on melanoma in the future chemotherapy and/or immunotherapy protocols. PMID:26135897

Overexpression of the VSSC-associated CAM, β-2, enhances LNCaP cell metastasis associated behavior.

PubMed

Jansson, Keith H; Lynch, Jill E; Lepori-Bui, Nadia; Czymmek, Kirk J; Duncan, Randall L; Sikes, Robert A

2012-07-01

Prostate cancer (PCa) is the second-leading cause of cancer death in American men. This is due largely to the "silent" nature of the disease until it has progressed to a highly metastatic and castrate resistant state. Voltage sensitive sodium channels (VSSCs) are multimeric transmembrane protein complexes comprised of a pore-forming α subunit and one or two β subunits. The β-subunits modulate surface expression and gating kinetics of the channels but also have inherent cell adhesion molecule (CAM) functions. We hypothesize that PCa cells use VSSC β-subunits as CAMs during PCa progression and metastasis. We overexpressed the beta-2 isoform as a C-terminal fusion protein with enhanced cyan fluorescence protein (ECFP) in the weakly metastatic LNCaP cells. The effect of beta-2 overexpression on cell morphology was examined using confocal microscopy while metastasis-associated behavior was tested by performing several in vitro metastatic functional assays and in vivo subcutaneous tumor studies. We found that cells overexpressing beta-2 (2BECFP) converted to a bipolar fibroblastic morphology. 2BECFP cells were more adhesive than control (ECFP) to vitronectin (twofold) and Matrigel® (1.3-fold), more invasive through Matrigel® (3.6-fold in 72 hr), and had enhanced migration (2.1-fold in 96 hr) independent of proliferation in wound-healing assays. In contrast, 2BECFP cells have a reduced tumor-take and tumor volume in vivo even though the overexpression of beta-2 was maintained. Functional overexpression of VSSC β-subunits in PCa may be one mechanism leading to increased metastatic behavior while decreasing the ability to form localized tumor masses. Copyright © 2011 Wiley Periodicals, Inc.

PNPLA3 overexpression results in reduction of proteins predisposing to fibrosis.

PubMed

Pingitore, Piero; Dongiovanni, Paola; Motta, Benedetta Maria; Meroni, Marica; Lepore, Saverio Massimo; Mancina, Rosellina Margherita; Pelusi, Serena; Russo, Cristina; Caddeo, Andrea; Rossi, Giorgio; Montalcini, Tiziana; Pujia, Arturo; Wiklund, Olov; Valenti, Luca; Romeo, Stefano

2016-12-01

Liver fibrosis is a pathological scarring response to chronic hepatocellular injury and hepatic stellate cells (HSCs) are key players in this process. PNPLA3 I148M is a common variant robustly associated with liver fibrosis but the mechanisms underlying this association are unknown. We aimed to examine a) the effect of fibrogenic and proliferative stimuli on PNPLA3 levels in HSCs and b) the role of wild type and mutant PNPLA3 overexpression on markers of HSC activation and fibrosis.Here, we show that PNPLA3 is upregulated by the fibrogenic cytokine transforming growth factor-beta (TGF-β), but not by platelet-derived growth factor (PDGF), and is involved in the TGF-β-induced reduction in lipid droplets in primary human HSCs. Furthermore, we show that retinol release from human HSCs ex vivo is lower in cells with the loss-of-function PNPLA3 148M compared with 148I wild type protein. Stable overexpression of PNPLA3 148I wild type, but not 148M mutant, in human HSCs (LX-2 cells) induces a reduction in the secretion of matrix metallopeptidase 2 (MMP2), tissue inhibitor of metalloproteinase 1 and 2 (TIMP1 and TIMP2), which is mediated by retinoid metabolism. In conclusion, we show a role for PNPLA3 in HSC activation in response to fibrogenic stimuli. Moreover, we provide evidence to indicate that PNPLA3-mediated retinol release may protect against liver fibrosis by inducing a specific signature of proteins involved in extracellular matrix remodelling. © The Author 2016. Published by Oxford University Press.

PNPLA3 overexpression results in reduction of proteins predisposing to fibrosis

PubMed Central

Pingitore, Piero; Dongiovanni, Paola; Motta, Benedetta Maria; Meroni, Marica; Lepore, Saverio Massimo; Mancina, Rosellina Margherita; Pelusi, Serena; Russo, Cristina; Caddeo, Andrea; Rossi, Giorgio; Montalcini, Tiziana; Pujia, Arturo; Wiklund, Olov; Valenti, Luca; Romeo, Stefano

2016-01-01

Abstract Liver fibrosis is a pathological scarring response to chronic hepatocellular injury and hepatic stellate cells (HSCs) are key players in this process. PNPLA3 I148M is a common variant robustly associated with liver fibrosis but the mechanisms underlying this association are unknown. We aimed to examine a) the effect of fibrogenic and proliferative stimuli on PNPLA3 levels in HSCs and b) the role of wild type and mutant PNPLA3 overexpression on markers of HSC activation and fibrosis. Here, we show that PNPLA3 is upregulated by the fibrogenic cytokine transforming growth factor-beta (TGF-β), but not by platelet-derived growth factor (PDGF), and is involved in the TGF-β-induced reduction in lipid droplets in primary human HSCs. Furthermore, we show that retinol release from human HSCs ex vivo is lower in cells with the loss-of-function PNPLA3 148M compared with 148I wild type protein. Stable overexpression of PNPLA3 148I wild type, but not 148M mutant, in human HSCs (LX-2 cells) induces a reduction in the secretion of matrix metallopeptidase 2 (MMP2), tissue inhibitor of metalloproteinase 1 and 2 (TIMP1 and TIMP2), which is mediated by retinoid metabolism. In conclusion, we show a role for PNPLA3 in HSC activation in response to fibrogenic stimuli. Moreover, we provide evidence to indicate that PNPLA3-mediated retinol release may protect against liver fibrosis by inducing a specific signature of proteins involved in extracellular matrix remodelling. PMID:27742777

Cytotoxic Effect Associated with Overexpression of QNR Proteins in Escherichia coli.

PubMed

Machuca, Jesús; Diaz de Alba, Paula; Recacha, Esther; Pascual, Álvaro; Rodriguez-Martinez, José Manuel

2017-10-01

The objective was to evaluate the cytotoxic effect associated with overexpression of multiple Qnr-like plasmid-mediated quinolone resistance (PMQR) mechanisms in Escherichia coli. Coding regions of different PMQR genes (qnrA1, qnrB1, qnrC, qnrD1, qnrS1, and qepA2) and efsqnr were cloned into pET29a(+) vector and overexpressed in E. coli BL21. E. coli BL21 with and without an empty pET29a(+) vector were used as controls. The cytotoxic effect associated with PMQR mechanism overexpression was determined by transmission electron microscopy and viability assays. Overexpressed qnr genes produced loss of bacterial viability in the range of 77-97% compared with the controls, comparable with loss of viability associated with EfsQnr overexpression (97%). No loss of viability was observed in E. coli overexpressing QepA2. In transmission electron microscopy assays, signs of cytotoxicity were observed in E. coli cells overexpressing EfsQnr and Qnr proteins (30-45% of the bacterial population showed morphological changes). Morphological changes were observed in less than 5% of bacterial populations from the control strains and E. coli overexpressing QepA2. Overexpression of qnr genes produces a cytotoxic cellular and structural effect in E. coli, the magnitude of which varies depending on the family of Qnr proteins.

Metallothionein - immunohistochemical cancer biomarker: a meta-analysis.

PubMed

Gumulec, Jaromir; Raudenska, Martina; Adam, Vojtech; Kizek, Rene; Masarik, Michal

2014-01-01

Metallothionein (MT) has been extensively investigated as a molecular marker of various types of cancer. In spite of the fact that numerous reviews have been published in this field, no meta-analytical approach has been performed. Therefore, results of to-date immunohistochemistry-based studies were summarized using meta-analysis in this review. Web of science, PubMed, Embase and CENTRAL databases were searched (up to April 30, 2013) and the eligibility of individual studies and heterogeneity among the studies was assessed. Random and fixed effects model meta-analysis was employed depending on the heterogeneity, and publication bias was evaluated using funnel plots and Egger's tests. A total of 77 studies were included with 8,015 tissue samples (4,631 cases and 3,384 controls). A significantly positive association between MT staining and tumors (vs. healthy tissues) was observed in head and neck (odds ratio, OR 9.95; 95% CI 5.82-17.03) and ovarian tumors (OR 7.83; 1.09-56.29), and a negative association was ascertained in liver tumors (OR 0.10; 0.03-0.30). No significant associations were identified in breast, colorectal, prostate, thyroid, stomach, bladder, kidney, gallbladder, and uterine cancers and in melanoma. While no associations were identified between MT and tumor staging, a positive association was identified with the tumor grade (OR 1.58; 1.08-2.30). In particular, strong associations were observed in breast, ovarian, uterine and prostate cancers. Borderline significant association of metastatic status and MT staining were determined (OR 1.59; 1.03-2.46), particularly in esophageal cancer. Additionally, a significant association between the patient prognosis and MT staining was also demonstrated (hazard ratio 2.04; 1.47-2.81). However, a high degree of inconsistence was observed in several tumor types, including colorectal, kidney and prostate cancer. Despite the ambiguity in some tumor types, conclusive results are provided in the tumors of head and

Meta-analysis of the effect of overexpression of CBF/DREB family genes on drought stress response

USDA-ARS?s Scientific Manuscript database

Transcription factors C-repeat/dehydration-responsive element binding proteins (CBF/DREB) play an important role in plant response to abiotic stresses. Over-expression of various CBF/DREB genes in diverse plants have been reported, but inconsistency of gene donor, recipient genus, parameters used i...

PACAP/VIP and receptor characterization in micturition pathways in mice with overexpression of NGF in urothelium.

PubMed

Girard, Beatrice M; Malley, Susan E; Braas, Karen M; May, Victor; Vizzard, Margaret A

2010-11-01

Urothelium-specific overexpression of nerve growth factor (NGF) in the urinary bladder of transgenic mice stimulates neuronal sprouting or proliferation in the urinary bladder, produces urinary bladder hyperreflexia, and results in increased referred somatic hypersensitivity. Additional NGF-mediated changes might contribute to the urinary bladder hyperreflexia and pelvic hypersensitivity observed in these transgenic mice such as upregulation of neuropeptide/receptor systems. Chronic overexpression of NGF in the urothelium was achieved through the use of a highly urothelium-specific, uroplakin II promoter. In the present study, we examined pituitary adenylate cyclase activating polypeptide (PACAP), vasoactive intestinal polypeptide (VIP), and associated receptor (PAC1, VPAC1, VPAC2) transcripts or protein expression in urothelium and detrusor smooth muscle and lumbosacral dorsal root ganglia in NGF-overexpressing and littermate wildtype mice using real-time quantitative reverse transcription-polymerase chain reaction and immunohistochemical approaches. Results demonstrate upregulation of PAC1 receptor transcript and PAC1-immunoreactivity in urothelium of NGF-OE mice whereas PACAP transcript and PACAP-immunoreactivity were decreased in urothelium of NGF-OE mice. In contrast, VPAC1 receptor transcript was decreased in both urothelium and detrusor smooth muscle of NGF-OE mice. VIP transcript expression and immunostaining was not altered in urinary bladder of NGF-OE mice. Changes in PACAP, VIP, and associated receptor transcripts and protein expression in micturition pathways resemble some, but not all, changes observed after induction of urinary bladder inflammation known to involve NGF production.

Redox susceptibility of SOD1 mutants is associated with the differential response to CCS over-expression in vivo.

PubMed

Son, Marjatta; Fu, Qiao; Puttaparthi, Krishna; Matthews, Christina M; Elliott, Jeffrey L

2009-04-01

Over-expression of CCS in G93A SOD1 mice accelerates neurological disease and enhances mitochondrial pathology. We studied the effect of CCS over-expression in transgenic mice expressing G37R, G86R or L126Z SOD1 mutations in order to understand factors which influence mitochondrial dysfunction. Over-expression of CCS markedly decreased survival and produced mitochondrial vacuolation in G37R SOD1 mice but not in G86R or L126Z SOD1 mice. Moreover, CCS/G37R SOD1 spinal cord showed specific reductions in mitochondrial complex IV subunits consistent with an isolated COX deficiency, while no such reductions were detected in CCS/G86R or CCS/L126Z SOD1 mice. CCS over-expression increased the ratio of reduced to oxidized SOD1 monomers in the spinal cords of G37R SOD1 as well as G93A SOD1 mice, but did not influence the redox state of G86R or L126Z SOD1 monomers. The effects of CCS on disease are SOD1 mutation dependent and correlate with SOD1 redox susceptibility.

Overexpression of the rubisco activase gene improves growth and low temperature and weak light tolerance in Cucumis sativus.

PubMed

Bi, Huangai; Liu, Peipei; Jiang, Zhensheng; Ai, Xizhen

2017-10-01

Rubisco activase (RCA) is an important enzyme that can catalyze the carboxylation and oxygenation activities of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), which is involved in the photosynthetic carbon reduction cycle. Here, we studied the effects of changes in RCA activity on photosynthesis, growth and development, as well as the low temperature and weak light tolerance of RCA overexpressing transgenic cucumber (Cucumis sativus) plants. CsRCA overexpression increased the plant height, leaf area and dry matter, and decreased the root/top ratio in transgenic cucumber plants compared with the wild-type (WT) plants. Low temperature and low light stress led to decreases in the CsRCA expression and protein levels, the photosynthetic rate (Pn) and the stomatal conductance (Gs), but an increase in the intercellular CO 2 (Ci) concentration in cucumber leaves. The actual photochemical efficiency and maximal photochemical efficiency of photosystem II in cucumber seedlings also declined, but the initial fluorescence increased during low temperature and weak light stress. Transgenic plants showed a lower decrease in the CsRCA expression level and actual and maximal photochemical efficiencies, as well as increases in the Ci and initial fluorescence relative to the WT plants. Low temperature and low light stress resulted in a significant increase in the malondialdehyde (MDA) content; however, this increase was reduced in transgenic plants compared with that in WT plants. Thus, the overexpression of CsRCA may promote the growth and low temperature and low light tolerance of cucumber plants in solar greenhouses. © 2017 Scandinavian Plant Physiology Society.

Over-Expression of the Mycobacterial Trehalose-Phosphate Phosphatase OtsB2 Results in a Defect in Macrophage Phagocytosis Associated with Increased Mycobacterial-Macrophage Adhesion

PubMed Central

Li, Hao; Wu, Mei; Shi, Yan; Javid, Babak

2016-01-01

Trehalose-6-phosphate phosphatase (OtsB2) is involved in the OtsAB trehalose synthesis pathway to produce free trehalose and is strictly essential for mycobacterial growth. We wished to determine the effects of OtsB2 expression on mycobacterial phenotypes such as growth, phagocytosis and survival in macrophages. Mycobacterium bovis-bacillus calmette-guerin (BCG) over-expressing OtsB2 were able to better survive in stationary phase. Over-expression of OtsB2 led to a decrease in phagocytosis but not survival in THP-1 macrophage-like cells, and this was not due to a decrease in general macrophage phagocytic activity. Surprisingly, when we investigated macrophage–mycobacterial interactions by flow cytometry and atomic force microscopy, we discovered that BCG over-expressing OtsB2 have stronger binding to THP-1 cells than wild-type BCG. These results suggest that altering OtsB2 expression has implications for mycobacterial host–pathogen interactions. Macrophage–mycobacteria phagocytic interactions are complex and merit further study. PMID:27867377

Atrial SERCA2a Overexpression Has No Affect on Cardiac Alternans but Promotes Arrhythmogenic SR Ca2+ Triggers

PubMed Central

Nassal, Michelle M. J.; Wan, Xiaoping; Laurita, Kenneth R.; Cutler, Michael J.

2015-01-01

Background Atrial fibrillation (AF) is the most common arrhythmia in humans, yet; treatment has remained sub-optimal due to poor understanding of the underlying mechanisms. Cardiac alternans precede AF episodes, suggesting an important arrhythmia substrate. Recently, we demonstrated ventricular SERCA2a overexpression suppresses cardiac alternans and arrhythmias. Therefore, we hypothesized that atrial SERCA2a overexpression will decrease cardiac alternans and arrhythmias. Methods Adult rat isolated atrial myocytes where divided into three treatment groups 1) Control, 2) SERCA2a overexpression (Ad.SERCA2a) and 3) SERCA2a inhibition (Thapsigargin, 1μm). Intracellular Ca2+ was measured using Indo-1AM and Ca2+ alternans (Ca-ALT) was induced with a standard ramp pacing protocol. Results As predicted, SR Ca2+ reuptake was enhanced with SERCA2a overexpression (p< 0.05) and reduced with SERCA2a inhibition (p<0.05). Surprisingly, there was no difference in susceptibility to Ca-ALT with either SERCA2a overexpression or inhibition when compared to controls (p = 0.73). In contrast, SERCA2a overexpression resulted in increased premature SR Ca2+ (SCR) release compared to control myocytes (28% and 0%, p < 0.05) and concomitant increase in SR Ca2+ load (p<0.05). Based on these observations we tested in-vivo atrial arrhythmia inducibility in control and Ad.SERCA2a animals using an esophageal atrial burst pacing protocol. There were no inducible atrial arrhythmias in Ad.GFP (n = 4) animals though 20% of Ad.SERCA2a (n = 5) animals had inducible atrial arrhythmias (p = 0.20). Conclusions Our findings suggest that unlike the ventricle, SERCA2a is not a key regulator of cardiac alternans in the atrium. Importantly, SERCA2a overexpression in atrial myocytes can increase SCR, which may be arrhythmogenic. PMID:26352986

Comparison of the response of serum ceruloplasmin and cholesterol, and of tissue ascorbic acid, metallothionein, and nonprotein sulfhydryl in rats to the dietary level of cystine and cysteine.

PubMed

Yang, B S; Yamazaki, M; Wan, Q; Kato, N

1996-12-01

The effects were compared of the addition of graded levels of L-cystine and of L-cysteine (0.3, 3, or 5%) to a 10% casein diet on several metabolic parameters in rats. The growth-promoting effect of cystine was equivalent to that of cysteine. Supplementation of these two amino acids elevated serum cholesterol, liver ascorbic acid, liver nonprotein sulfhydryl (SH) and kidney metallothionein, and reduced the activity of serum ceruloplasmin. The responses of serum cholesterol, liver nonprotein SH, and serum ceruloplasmin to cystine were greater than of those to cysteine. When the basal diet was supplemented with 0.3% of these amino acids, the elevation of liver ascorbic acid by cystine supplementation was less than that by cysteine supplementation. However, when supplemented with 5% of these amino acids, the elevation of liver ascorbic acid by cystine was greater than that by cysteine. There was no difference in the influence of cystine and cysteine on kidney metallothionein. This study demonstrates that dietary cystine and cysteine had the same influence on growth, but had a differential influence on such metabolic parameters as liver nonprotein SH, serum ceruloplasmin, serum cholesterol, and tissue ascorbic acid.

Decreased expression of microRNA-29 family in leiomyoma contributes to increased major fibrillar collagen production.

PubMed

Marsh, Erica E; Steinberg, Marissa L; Parker, J Brandon; Wu, Ju; Chakravarti, Debabrata; Bulun, Serdar E

2016-09-01

To determine the expression and function of the microRNA-29 family (miRNA-29a, miRNA-29b, miRNA-29c) in human leiomyoma and myometrium. Basic science experimental design. Academic medical center. Women undergoing surgery for symptomatic uterine fibroids. Overexpression and knockdown of miRNA-29a, miRNA-29b, and miRNA-29c in primary leiomyoma and myometrial cells. [1] Expression of the miRNA-29 family members in vivo in leiomyoma versus myometrium; [2] Major fibrillar collagen (I, II, III) expression in leiomyoma and myometrial cells with manipulation of miRNA-29 species. Members of the miRNA-29 family (29a, 29b, 29c) are all down-regulated in leiomyoma versus myometrium in vivo. The expression of the miRNA-29 family can be successfully modulated in primary leiomyoma and myometrial cells. Overexpression of the miRNA-29 family in leiomyoma cells results in down-regulation of the major fibrillar collagens. Down-regulation of the miRNA-29 species in myometrium results in an increase in collagen type III deposition. The miRNA-29 family is consistently down-regulated in leiomyoma compared to matched myometrial tissue. This down-regulation contributes to the increased collagen seen in leiomyomas versus myometrium. When miRNA-29 members are overexpressed in leiomyoma cells, protein levels of all of the major fibrillar collagens decrease. The miRNA-29 members are potential therapeutic targets in this highly prevalent condition. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Overexpression of inducible 70-kDa heat shock protein in mouse improves structural and functional recovery of skeletal muscles from atrophy.

PubMed

Miyabara, Elen H; Nascimento, Tabata L; Rodrigues, Débora C; Moriscot, Anselmo S; Davila, Wilmer F; AitMou, Younss; deTombe, Pieter P; Mestril, Ruben

2012-04-01

Heat shock proteins play a key regulatory role in cellular defense. To investigate the role of the inducible 70-kDa heat shock protein (HSP70) in skeletal muscle atrophy and subsequent recovery, soleus (SOL) and extensor digitorum longus (EDL) muscles from overexpressing HSP70 transgenic mice were immobilized for 7 days and subsequently released from immobilization and evaluated after 7 days. Histological analysis showed that there was a decrease in cross-sectional area of type II myofiber from EDL and types I and II myofiber from SOL muscles at 7-day immobilization in both wild-type and HSP70 mice. At 7-day recovery, EDL and SOL myofibers from HSP70 mice, but not from wild-type mice, recovered their size. Muscle tetanic contraction decreased only in SOL muscles from wild-type mice at both 7-day immobilization and 7-day recovery; however, it was unaltered in the respective groups from HSP70 mice. Although no effect in a fatigue protocol was observed among groups, we noticed a better contractile performance of EDL muscles from overexpressing HSP70 groups as compared to their matched wild-type groups. The number of NCAM positive-satellite cells reduced after immobilization and recovery in both EDL and SOL muscles from wild-type mice, but it was unchanged in the muscles from HSP70 mice. These results suggest that HSP70 improves structural and functional recovery of skeletal muscle after disuse atrophy, and this effect might be associated with preservation of satellite cell amount.

Glutamate Excitotoxicity Linked to Spermine Oxidase Overexpression.

PubMed

Pietropaoli, Stefano; Leonetti, Alessia; Cervetto, Chiara; Venturini, Arianna; Mastrantonio, Roberta; Baroli, Giulia; Persichini, Tiziana; Colasanti, Marco; Maura, Guido; Marcoli, Manuela; Mariottini, Paolo; Cervelli, Manuela

2018-02-03

Excitotoxic stress has been associated with several different neurological disorders, and it is one of the main causes of neuronal degeneration and death. To identify new potential proteins that could represent key factors in excitotoxic stress and to study the relationship between polyamine catabolism and excitotoxic damage, a novel transgenic mouse line overexpressing spermine oxidase enzyme in the neocortex (Dach-SMOX) has been engineered. These transgenic mice are more susceptible to excitotoxic injury and display a higher oxidative stress, highlighted by 8-Oxo-2'-deoxyguanosine increase and activation of defense mechanisms, as demonstrated by the increase of nuclear factor erythroid 2-related factor 2 (Nrf-2) in the nucleus. In Dach-SMOX astrocytes and neurons, an alteration of the phosphorylated and non-phosphorylated subunits of glutamate receptors increases the kainic acid response in these mice. Moreover, a decrease in excitatory amino acid transporters and an increase in the system x c - transporter, a Nrf-2 target, was observed. Sulfasalazine, a system x c - transporter inhibitor, was shown to revert the increased susceptibility of Dach-SMOX mice treated with kainic acid. We demonstrated that astrocytes play a crucial role in this process: neuronal spermine oxidase overexpression resulted in an alteration of glutamate excitability, in glutamate uptake and efflux in astrocytes involved in the synapse. Considering the involvement of oxidative stress in many neurodegenerative diseases, Dach-SMOX transgenic mouse can be considered as a suitable in vivo genetic model to study the involvement of spermine oxidase in excitotoxicity, which can be considered as a possible therapeutic target.

NF-E2 Overexpression Delays Erythroid Maturation and Increases Erythrocyte Production

PubMed Central

Mutschler, Manuel; Magin, Angela S.; Buerge, Martina; Roelz, Roland; Schanne, Daniel H.; Will, Britta; Pilz, Ingo H.; Migliaccio, Anna Rita; Pahl, Heike L.

2009-01-01

Summary The transcription factor Nuclear Factor-Erythroid 2 (NF-E2) is overexpressed in the vast majority of patients with polycythaemia vera (PV). In murine models, NF-E2 overexpression increases proliferation and promotes cellular viability in the absence of erythropoietin (EPO). EPO-independent growth is a hallmark of PV. We therefore hypothesized that NF-E2 overexpression contributes to erythrocytosis, the pathognomonic feature of PV. Consequently, we investigated the effect of NF-E2 overexpression in healthy CD34+ cells. NF-E2 overexpression led to a delay in erythroid maturation, manifested by a belated appearance of glycophorin A-positive erythroid precursors. Maturation delay was similarly observed in primary PV patient erythroid cultures compared to healthy controls. Protracted maturation led to a significant increase in the accumulated number of erythroid cells both in PV cultures and in CD34+ cells overexpressing NF-E2. Similarly, NF-E2 overexpression altered erythroid colony formation, leading to an increase in BFU-E formation. These data indicate that NF-E2 overexpression delays the early phase of erythroid maturation, resulting in an expansion of erythroid progenitors, thereby increasing the number of erythrocytes derived from one CD34+ cell. These data propose a role for NF-E2 in mediating the erythrocytosis of PV. PMID:19466964

Overexpression of antioxidant enzymes in diaphragm muscle does not alter contraction-induced fatigue or recovery

PubMed Central

McClung, Joseph M.; DeRuisseau, Keith C.; Whidden, Melissa A.; Van Remmen, Holly; Richardson, Arlan; Song, Wook; Vrabas, Ioannis S.; Powers, Scott K.

2010-01-01

Low levels of reactive oxygen species (ROS) production are necessary to optimize muscle force production in unfatigued muscle. In contrast, sustained high levels of ROS production have been linked to impaired muscle force production and contraction-induced skeletal muscle fatigue. Using genetically engineered mice, we tested the hypothesis that the independent transgenic overexpression of catalase (CAT), copper/zinc superoxide dismutase (CuZnSOD; SOD1) or manganese superoxide dismutase (MnSOD; SOD2) antioxidant enzymes would negatively affect force production in unfatigued diaphragm muscle but would delay the development of muscle fatigue and enhance force recovery after fatiguing contractions. Diaphragm muscle from wild-type littermates (WT) and from CAT, SOD1 and SOD2 overexpressing mice were subjected to an in vitro contractile protocol to investigate the force–frequency characteristics, the fatigue properties and the time course of recovery from fatigue. The CAT, SOD1 and SOD2 overexpressors produced less specific force (in N cm−2) at stimulation frequencies of 20–300 Hz and produced lower maximal tetanic force than WT littermates. The relative development of muscle fatigue and recovery from fatigue were not influenced by transgenic overexpression of any antioxidant enzyme. Morphologically, the mean cross-sectional area (in μm2) of diaphragm myofibres expressing myosin heavy chain type IIA was decreased in both CAT and SOD2 transgenic animals, and the percentage of non-contractile tissue increased in diaphragms from all transgenic mice. In conclusion, our results do not support the hypothesis that overexpression of independent antioxidant enzymes protects diaphragm muscle from contraction-induced fatigue or improves recovery from fatigue. Moreover, our data are consistent with the concept that a basal level of ROS is important to optimize muscle force production, since transgenic overexpression of major cellular antioxidants is associated with

Overexpression of SepJ alters septal morphology and heterocyst pattern regulated by diffusible signals in Anabaena.

PubMed

Mariscal, Vicente; Nürnberg, Dennis J; Herrero, Antonia; Mullineaux, Conrad W; Flores, Enrique

2016-09-01

Filamentous, N2 -fixing, heterocyst-forming cyanobacteria grow as chains of cells that are connected by septal junctions. In the model organism Anabaena sp. strain PCC 7120, the septal protein SepJ is required for filament integrity, normal intercellular molecular exchange, heterocyst differentiation, and diazotrophic growth. An Anabaena strain overexpressing SepJ made wider septa between vegetative cells than the wild type, which correlated with a more spread location of SepJ in the septa as observed with a SepJ-GFP fusion, and contained an increased number of nanopores, the septal peptidoglycan perforations that likely accommodate septal junctions. The septa between heterocysts and vegetative cells, which are narrow in wild-type Anabaena, were notably enlarged in the SepJ-overexpressing mutant. Intercellular molecular exchange tested with fluorescent tracers was increased for the SepJ-overexpressing strain specifically in the case of calcein transfer between vegetative cells and heterocysts. These results support an association between calcein transfer, SepJ-related septal junctions, and septal peptidoglycan nanopores. Under nitrogen deprivation, the SepJ-overexpressing strain produced an increased number of contiguous heterocysts but a decreased percentage of total heterocysts. These effects were lost or altered in patS and hetN mutant backgrounds, supporting a role of SepJ in the intercellular transfer of regulatory signals for heterocyst differentiation. © 2016 John Wiley & Sons Ltd.

The Functions of Metamorphic Metallothioneins in Zinc and Copper Metabolism.

PubMed

Krężel, Artur; Maret, Wolfgang

2017-06-09

Recent discoveries in zinc biology provide a new platform for discussing the primary physiological functions of mammalian metallothioneins (MTs) and their exquisite zinc-dependent regulation. It is now understood that the control of cellular zinc homeostasis includes buffering of Zn 2+ ions at picomolar concentrations, extensive subcellular re-distribution of Zn 2+ , the loading of exocytotic vesicles with zinc species, and the control of Zn 2+ ion signalling. In parallel, characteristic features of human MTs became known: their graded affinities for Zn 2+ and the redox activity of their thiolate coordination environments. Unlike the single species that structural models of mammalian MTs describe with a set of seven divalent or eight to twelve monovalent metal ions, MTs are metamorphic. In vivo, they exist as many species differing in redox state and load with different metal ions. The functions of mammalian MTs should no longer be considered elusive or enigmatic because it is now evident that the reactivity and coordination dynamics of MTs with Zn 2+ and Cu⁺ match the biological requirements for controlling-binding and delivering-these cellular metal ions, thus completing a 60-year search for their functions. MT represents a unique biological principle for buffering the most competitive essential metal ions Zn 2+ and Cu⁺. How this knowledge translates to the function of other families of MTs awaits further insights into the specifics of how their properties relate to zinc and copper metabolism in other organisms.

Crambescin C1 Exerts a Cytoprotective Effect on HepG2 Cells through Metallothionein Induction

PubMed Central

Roel, María; Rubiolo, Juan A.; Ternon, Eva; Thomas, Olivier P.; Vieytes, Mercedes R.; Botana, Luis M.

2015-01-01

The Mediterranean marine sponge Crambe crambe is the source of two families of guanidine alkaloids known as crambescins and crambescidins. Some of the biological effects of crambescidins have been previously reported while crambescins have undergone little study. Taking this into account, we performed comparative transcriptome analysis to examine the effect of crambescin-C1 (CC1) on human tumor hepatocarcinoma cells HepG2 followed by validation experiments to confirm its predicted biological activities. We report herein that, while crambescin-A1 has a minor effect on these cells, CC1 protects them against oxidative injury by means of metallothionein induction even at low concentrations. Additionally, at high doses, CC1 arrests the HepG2 cell cycle in G0/G1 and thus inhibits tumor cell proliferation. The findings presented here provide the first detailed approach regarding the different effects of crambescins on tumor cells and provide a basis for future studies on other possible cellular mechanisms related to these bioactivities. PMID:26225985

Cyclophilin A Is Overexpressed in Hepatocellular Carcinoma and Is Associated with the Cell Cycle.

PubMed

Gong, Zhaohua; Chi, Cheng; Huang, Xiaojuan; Chu, Hongjin; Wang, Jiahui; Du, Fengcai; Jiang, Lixin; Chen, Jian

2017-08-01

To investigate the expression of cyclophilin A (CypA) in human hepatocellular carcinoma (HCC) and explore the effects of CypA on the cell cycle in HCC. CypA expression was assessed by immunohistochemistry in 48 cases of HCC tissues and paired adjacent tissues. CypA plasmid was transfected into HCC cells and the cell cycle was analyzed. Positivity for CypA was higher in HCC tissues than in adjacent tissues (79.1% vs. 12.5%, p<0.05). Positivity for CypA was significantly higher in stage III and IV HCC than in stage I and II (p<0.05). Elevated CypA induced an increase of the percentage of S-phase cells (from 34.79% to 42.14%) and a decrease of G 0 -G 1 phase cells (from 58.10% to 50.64%). CypA is overexpressed in HCC and is associated with TNM stage. CypA also appears to promote the transition of the cell cycle from G 1 to S phase. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

CENPI is overexpressed in colorectal cancer and regulates cell migration and invasion.

PubMed

Ding, Na; Li, Rongxin; Shi, Wenhao; He, Cui

2018-06-21

Centromere protein I (CENPI),an important member of centromere protein family, has been suggest to serve as a oncogene in breast cancer, but the clinical significance and biological function of CENPI in colorectal cancer (CRC) is still unclear. In our results, we found CENPI was overexpressed in CRC tissues and cells, and associated with clinical stage, tumor depth, lymph node metastasis, distant metastasis and differentiation in CRC patients. However, there was no significant association between CENPI protein expression and overall survival time in colon cancer patients and rectal cancer patients through analyzing TCGA survival data. Moreover, CENPI mRNA and protein were increased in metastatic lymph nodes compared with primary CRC tissues. Down-regulation of CENPI expression suppresses CRC cell migration, invasion and epithelial mesenchymal transition process. In conclusion, CENPI is overexpressed in CRC and functions as oncogene in modulating CRC cell migration, invasion and EMT process. Copyright © 2018. Published by Elsevier B.V.

β-catenin nuclear translocation induced by HIF-1α overexpression leads to the radioresistance of prostate cancer

PubMed Central

Luo, Yong; Li, Mingchuan; Zuo, Xuemei; Basourakos, Spyridon P.; Zhang, Jiao; Zhao, Jiahui; Han, Yili; Lin, Yunhua; Wang, Yongxing; Jiang, Yongguang; Lan, Ling

2018-01-01

Hypoxia-inducible factor-1α (HIF-1α) is known to play crucial roles in tumor radioresistance; however, the molecular mechanisms responsible for the promotion of tumor radioresistance by HIF-1α remain unclear. β-catenin is known to be involved in the metastatic potential of prostate cancer (PCa). In this study, to investigate the role of HIF-1α and β-catenin in the radioresistance of PCa, two PCa cell lines, LNCaP and C4-2B, were grouped as follows: Negative control (no treatment), HIF-1α overexpression group (transfected with HIF-1α overexpression plasmid) and β-catenin silenced group (transfected with HIF-1α plasmids and β-catenin-shRNA). Cell proliferation, cell cycle, cell invasion and radiosensitivity were examined under normal or hypoxic conditions. In addition, radiosensitivity was examined in two mouse PCa models (the LNCaP orthotopic BALB/c-nu mice model and the C4-2B subcutaneous SCID mice model). Our results revealed that in both the LNCaP and C4-2B cells, transfection with HIF-1α overexpression plasmid led to an enhanced β-catenin nuclear translocation, while β-catenin silencing inhibited β-catenin nuclear translocation. The enhanced β-catenin nuclear translocation induced by HIF-1α overexpression resulted in an enhanced cell proliferation and cell invasion, an altered cell cycle distribution, decreased apoptosis, and improved non-homologous end joining (NHEJ) repair under normal and irradiation conditions. Similar results were observed in the animal models. HIF-1α overexpression enhanced β-catenin nuclear translocation, which led to the activation of the β-catenin/NHEJ signaling pathway and increased cell proliferation, cell invasion and DNA repair. These results thus suggest that HIF-1α overexpression promotes the radioresistance of PCa cells. PMID:29658569

Overexpression of the PP2A regulatory subunit Tap46 leads to enhanced plant growth through stimulation of the TOR signalling pathway

PubMed Central

Ahn, Chang Sook; Ahn, Hee-Kyung; Pai, Hyun-Sook

2015-01-01

Tap46, a regulatory subunit of protein phosphatase 2A (PP2A), plays an essential role in plant growth and development through a functional link with the Target of Rapamycin (TOR) signalling pathway. Here, we have characterized the molecular mechanisms behind a gain-of-function phenotype of Tap46 and its relationship with TOR to gain further insights into Tap46 function in plants. Constitutive overexpression of Tap46 in Arabidopsis resulted in overall growth stimulation with enlarged organs, such as leaves and siliques. Kinematic analysis of leaf growth revealed that increased cell size was mainly responsible for the leaf enlargement. Tap46 overexpression also enhanced seed size and viability under accelerated ageing conditions. Enhanced plant growth was also observed in dexamethasone (DEX)-inducible Tap46 overexpression Arabidopsis lines, accompanied by increased cellular activities of nitrate-assimilating enzymes. DEX-induced Tap46 overexpression and Tap46 RNAi resulted in increased and decreased phosphorylation of S6 kinase (S6K), respectively, which is a sensitive indicator of endogenous TOR activity, and Tap46 interacted with S6K in planta based on bimolecular fluorescence complementation and co-immunoprecipitation. Furthermore, inactivation of TOR by estradiol-inducible RNAi or rapamycin treatment decreased Tap46 protein levels, but increased PP2A catalytic subunit levels. Real-time quantitative PCR analysis revealed that Tap46 overexpression induced transcriptional modulation of genes involved in nitrogen metabolism, ribosome biogenesis, and lignin biosynthesis. These findings suggest that Tap46 modulates plant growth as a positive effector of the TOR signalling pathway and Tap46/PP2Ac protein abundance is regulated by TOR activity. PMID:25399018

SWATH™- and iTRAQ-based quantitative proteomic analyses reveal an overexpression and biological relevance of CD109 in advanced NSCLC.

PubMed

Zhang, Fanglin; Lin, Hechun; Gu, Aiqin; Li, Jing; Liu, Lei; Yu, Tao; Cui, Yongqi; Deng, Wei; Yan, Mingxia; Li, Jinjun; Yao, Ming

2014-05-06

To identify cancer-related proteins, we used isobaric tags in a relative and absolute quantitation (iTRAQ) proteomic approach and SWATH™ quantification approach to analyze the secretome of an isogenic pair of highly metastatic and low metastatic non-small-cell lung cancer (NSCLC) cell lines. In addition, we compared two groups of pooled serum samples (12 early-stage and 12 late-stage patients) to mine data for candidates screened by iTRAQ-labeled proteomic analysis. A total of 110 proteins and 71 proteins were observed to be significantly differentially expressed in the cell line secretome and NSCLC sera, respectively. Among these proteins, CD109 was found to be highly expressed in both the highly metastatic cell line secretome and the group of late-stage patients. A sandwich ELISA assay also demonstrated an elevation of serum CD109 levels in individual NSCLC patients (n=30) compared with healthy subjects (n=19). Furthermore, CD109 displayed higher expression in lung cancer tissues compared with their matched noncancerous lung tissues (n=72). In addition, the knockdown of CD109 influenced several NSCLC cell bio-functions, for instance, depressing cell growth, affecting cell cycle phases. These phenomena suggest that CD109 plays a critical role in NSCLC progression. We simultaneously applied two quantitative proteomic approaches-iTRAQ-labeling and SWATH™-to analyze the secretome of metastatic cell lines, in order to explore the cancer-associated proteins in conditioned media. In this study, our results indicate that CD109 plays a critical role in non-small-cell lung cancer (NSCLC) progression, and is overexpressed in advanced NSCLC. Copyright © 2014 Elsevier B.V. All rights reserved.

B-cell translocation gene 3 overexpression inhibits proliferation and invasion of colorectal cancer SW480 cells via Wnt/β-catenin signaling pathway.

PubMed

Mao, D; Qiao, L; Lu, H; Feng, Y

2016-01-01

Increasing evidences have shown that B-cell translocation gene 3 (BTG3) inhibits metastasis of multiple cancer cells. However, the role of BTG3 in colorectal cancer (CRC) and its possible mechanism have not yet been reported. In our study, we evaluated BTG3 expression in several CRC cell lines. Then, pcDNA3.1-BTG3 was transfected into SW480 cells. We found that BTG3 was upregulated in SW480 cells after overexpression plasmid transfection. BTG3 overexpression significantly inhibited cell growth and decreased PCNA (proliferating cell nuclear antigen) and Ki67 levels. BTG3 overexpression markedly downregulated Cyclin D1 and Cyclin E1 levels, whereas elevated p27. Overexpression of BTG3 arrested the cell cycle at G1 phase, which was abrogated by p27 silencing. Furthermore, migration, invasion and EMT of SW480 cells were significantly suppressed by BTG3 overexpression. Further investigations showed the inhibition of Wnt/β-catenin signaling pathway. We then used GSK3β specific inhibitor SB-216763 to activate the Wnt/β-catenin signaling pathway. We found that Wnt/β-catenin signaling pathway activation reversed the effect of BTG3 overexpression on cell proliferation, cell cycle progression, invasion and EMT. In conclusion, BTG3 overexpression inhibited cell growth, induced cell cycle arrest and suppressed the metastasis of SW480 cells via the Wnt/β-catenin signaling pathway. BTG3 may be considered as a therapeutic target in CRC treatment.

Evaluating the influence of National Research Council levels of copper, iron, manganese, and zinc using organic (Bioplex) minerals on resulting tissue mineral concentrations, metallothionein, and liver antioxidant enzymes in grower-finisher swine diets.

PubMed

Gowanlock, D W; Mahan, D C; Jolliff, J S; Hill, G M

2015-03-01

Graded levels of a trace mineral premix containing an organic (Bioplex) source of Cu, Fe, Mn, and Zn was evaluated with additional treatments containing organic Zn or Fe. Grower-finisher pigs were fed from 25 to 115 kg BW. The number of pigs in the experiment, the breeding/genetics of the pigs, the management, and the average age of the pigs were previously reported. The experiment was conducted as a randomized complete block design in 7 replicates. Treatments were 1) basal diet without supplemental Cu, Fe, Mn, and Zn; 2) basal diet + 2.5 mg/kg Cu, 50 mg/kg Fe, 1.5 mg/kg Mn, and 40 mg/kg Zn (50% NRC); 3) basal diet + 5 mg/kg Cu, 100 mg/kg Fe, 3 mg/kg Mn, and 80 mg/kg Zn (100% NRC); 4) basal diet + 25 mg Zn/kg; 5) basal diet + 50 mg Zn/kg; and 6) basal diet + 50 mg Fe/kg. Selenium and I were added to all diets at 0.3 and 0.14 mg/kg, respectively. Diets were composed of corn-soybean meal, dicalcium phosphate, and limestone with phytase added to enhance mineral availability. Three pigs per pen were bled at 55, 80, and 115 kg BW and plasma was analyzed for microminerals. When the average replicate BW was 115 kg, 3 pigs per pen of an equal gender ratio were killed. The liver, kidney, and heart were removed and analyzed for microminerals. Liver, duodenum, and jejunal metallothionein and the antioxidant enzymes in the liver containing these microminerals were determined. The results demonstrated that plasma minerals were unaffected at the 3 BW intervals. Liver and duodenum metallothionein protein were greater ( < 0.05) as dietary micromineral levels increased but jejunum metallothionein did not change as microminerals increased. The activity of Cu/Zn superoxide dismutase (SOD) was not affected as the levels of the micromineral increased, whereas the activity of Mn SOD increased slightly ( < 0.05) to the 50% NRC treatment level. Liver Zn (relative and total) increased ( < 0.05) as dietary micromineral levels increased and also when Zn was added singly to the diet. Liver

Doxorubicin induces ZAKα overexpression with a subsequent enhancement of apoptosis and attenuation of survivability in human osteosarcoma cells.

PubMed

Fu, Chien-Yao; Tseng, Yan-Shen; Chen, Ming-Cheng; Hsu, Hsi-Hsien; Yang, Jaw-Ji; Tu, Chuan-Chou; Lin, Yueh-Min; Viswanadha, Vijaya Padma; Kuo, Wei-Wen; Huang, Chih-Yang

2018-02-01

Human osteosarcoma (OS) is a malignant cancer of the bone. It exhibits a characteristic malignant osteoblastic transformation and produces a diseased osteoid. A previous study demonstrated that doxorubicin (DOX) chemotherapy decreases human OS cell proliferation and might enhance the relative RNA expression of ZAK. However, the impact of ZAKα overexpression on the OS cell proliferation that is inhibited by DOX and the molecular mechanism underlying this effect are not yet known. ZAK is a protein kinase of the MAPKKK family and functions to promote apoptosis. In our study, we found that ZAKα overexpression induced an apoptotic effect in human OS cells. Treatment of human OS cells with DOX enhanced ZAKα expression and decreased cancer cell viability while increasing apoptosis of human OS cells. In the meantime, suppression of ZAKα expression using shRNA and inhibitor D1771 both suppressed the DOX therapeutic effect. These findings reveal a novel molecular mechanism underlying the DOX effect on human OS cells. Taken together, our findings demonstrate that ZAKα enhances the apoptotic effect and decreases cell viability in DOX-treated human OS cells. © 2017 Wiley Periodicals, Inc.

Resolving the role of plant glutamate dehydrogenase: II. Physiological characterization of plants overexpressing the two enzyme subunits individually or simultaneously.

PubMed

Tercé-Laforgue, Thérèse; Bedu, Magali; Dargel-Grafin, Céline; Dubois, Frédéric; Gibon, Yves; Restivo, Francesco M; Hirel, Bertrand

2013-10-01

Glutamate dehydrogenase (GDH; EC 1.4.1.2) is able to carry out the deamination of glutamate in higher plants. In order to obtain a better understanding of the physiological function of GDH in leaves, transgenic tobacco (Nicotiana tabacum L.) plants were constructed that overexpress two genes from Nicotiana plumbaginifolia (GDHA and GDHB under the control of the Cauliflower mosiac virus 35S promoter), which encode the α- and β-subunits of GDH individually or simultaneously. In the transgenic plants, the GDH protein accumulated in the mitochondria of mesophyll cells and in the mitochondria of the phloem companion cells (CCs), where the native enzyme is normally expressed. Such a shift in the cellular location of the GDH enzyme induced major changes in carbon and nitrogen metabolite accumulation and a reduction in growth. These changes were mainly characterized by a decrease in the amount of sucrose, starch and glutamine in the leaves, which was accompanied by an increase in the amount of nitrate and Chl. In addition, there was an increase in the content of asparagine and a decrease in proline. Such changes may explain the lower plant biomass determined in the GDH-overexpressing lines. Overexpressing the two genes GDHA and GDHB individually or simultaneously induced a differential accumulation of glutamate and glutamine and a modification of the glutamate to glutamine ratio. The impact of the metabolic changes occurring in the different types of GDH-overexpressing plants is discussed in relation to the possible physiological function of each subunit when present in the form of homohexamers or heterohexamers.

Functional Analysis With a Barcoder Yeast Gene Overexpression System

PubMed Central

Douglas, Alison C.; Smith, Andrew M.; Sharifpoor, Sara; Yan, Zhun; Durbic, Tanja; Heisler, Lawrence E.; Lee, Anna Y.; Ryan, Owen; Göttert, Hendrikje; Surendra, Anu; van Dyk, Dewald; Giaever, Guri; Boone, Charles; Nislow, Corey; Andrews, Brenda J.

2012-01-01

Systematic analysis of gene overexpression phenotypes provides an insight into gene function, enzyme targets, and biological pathways. Here, we describe a novel functional genomics platform that enables a highly parallel and systematic assessment of overexpression phenotypes in pooled cultures. First, we constructed a genome-level collection of ~5100 yeast barcoder strains, each of which carries a unique barcode, enabling pooled fitness assays with a barcode microarray or sequencing readout. Second, we constructed a yeast open reading frame (ORF) galactose-induced overexpression array by generating a genome-wide set of yeast transformants, each of which carries an individual plasmid-born and sequence-verified ORF derived from the Saccharomyces cerevisiae full-length EXpression-ready (FLEX) collection. We combined these collections genetically using synthetic genetic array methodology, generating ~5100 strains, each of which is barcoded and overexpresses a specific ORF, a set we termed “barFLEX.” Additional synthetic genetic array allows the barFLEX collection to be moved into different genetic backgrounds. As a proof-of-principle, we describe the properties of the barFLEX overexpression collection and its application in synthetic dosage lethality studies under different environmental conditions. PMID:23050238

Sleep Dysfunction and EEG Alterations in Mice Overexpressing Alpha-Synuclein

PubMed Central

McDowell, Kimberly A.; Shin, David; Roos, Kenneth P.; Chesselet, Marie-Françoise

2018-01-01

Background: Sleep disruptions occur early and frequently in Parkinson’s disease (PD). PD patients also show a slowing of resting state activity. Alpha-synuclein is causally linked to PD and accumulates in sleep-related brain regions. While sleep problems occur in over 75% of PD patients and severely impact the quality of life of patients and caregivers, their study is limited by a paucity of adequate animal models. Objective: The objective of this study was to determine whether overexpression of wildtype alpha-synuclein could lead to alterations in sleep patterns reminiscent of those observed in PD by measuring sleep/wake activity with rigorous quantitative methods in a well-characterized genetic mouse model. Methods: At 10 months of age, mice expressing human wildtype alpha-synuclein under the Thy-1 promoter (Thy1-aSyn) and wildtype littermates underwent the subcutaneous implantation of a telemetry device (Data Sciences International) for the recording of electromyograms (EMG) and electroencephalograms (EEG) in freely moving animals. Surgeries and data collection were performed without knowledge of mouse genotype. Results: Thy1-aSyn mice showed increased non-rapid eye movement sleep during their quiescent phase, increased active wake during their active phase, and decreased rapid eye movement sleep over a 24-h period, as well as a shift in the density of their EEG power spectra toward lower frequencies with a significant decrease in gamma power during wakefulness. Conclusions: Alpha-synuclein overexpression in mice produces sleep disruptions and altered oscillatory EEG activity reminiscent of PD, and this model provides a novel platform to assess mechanisms and therapeutic strategies for sleep dysfunction in PD. PMID:24867919

Targeted Delivery of Pulmonary Arterial Endothelial Cells Overexpressing Interleukin-8 Receptors Attenuates Monocrotaline-Induced Pulmonary Vascular Remodeling

PubMed Central

Fu, Jinyan; Chen, Yiu-Fai; Zhao, Xiangmin; Creighton, Judy; Guo, Yuan-Yuan; Hage, Fadi G.; Oparil, Suzanne; Xing, Daisy D.

2014-01-01

Objective Interleukin-8 (IL8) receptors IL8RA and IL8RB (ILRA/B) on neutrophil membranes bind to IL8 with high affinity and play a critical role in neutrophil recruitment to sites of injury and/or inflammation. This study tested the hypothesis that administration of rat pulmonary arterial endothelial cells (ECs) overexpressing IL8RA/B can accelerate the adhesion of ECs to the injured lung and inhibit monocrotaline (MCT)-induced pulmonary inflammation, arterial thickening and hypertension, and right ventricular (RV) hypertrophy. Approach and Results The treatment groups included 10-wk-old ovariectomized Sprague-Dawley rats that received s.c. injection of phosphate-buffered-saline (Vehicle); a single injection of MCT (MCT alone, 60 mg/kg, s.c.); MCT followed by i.v. transfusion of ECs transduced with the empty adenoviral vector (Null-EC); and MCT followed by i.v. transfusion of ECs overexpressing IL8RA/B (IL8RA/B-EC, 1.5×106 cells/rat). Two days or 4 wks after MCT treatment, eNOS, iNOS, CINC-2β (IL8 equivalent in rat) and MCP-1 expression; neutrophil and macrophage infiltration into pulmonary arterioles, and arteriolar and alveolar morphology were measured by histological and immunohistochemical techniques. Pro-inflammatory cytokine/chemokine protein levels were measured by Multiplexed rat specific magnetic beads based sandwich immunoassay in total lung homogenates. Transfusion of IL8RA/B-ECs significantly reduced MCT-induced neutrophil infiltration and pro-inflammatory mediator (IL-8, MCP-1, iNOS, CINC and MIP-2) expression in lungs and pulmonary arterioles and alveoli, pulmonary artery pressure, and pulmonary arteriole and RV hypertrophy and remodeling. Conclusion These provocative findings suggest that targeted delivery of ECs overexpressing IL8RA/B is effective in repairing the injured pulmonary vasculature. PMID:24790141

Overexpression of BAG3 Attenuates Hypoxia-Induced Cardiomyocyte Apoptosis by Inducing Autophagy.

PubMed

Zhang, Jiankai; He, Zhangyou; Xiao, Wenjian; Na, Qingqing; Wu, Tianxiu; Su, Kaixin; Cui, Xiaojun

2016-01-01

Hypoxia is a well-known factor in the promotion of apoptosis, which contributes to the development of numerous cardiac diseases, such as heart failure and myocardial infarction. Inhibiting apoptosis is an important therapeutic strategy for the treatment of related heart diseases caused by ischemia/hypoxic injury. Previous studies have demonstrated that BAG3 plays an important role in cardiomyocyte apoptosis and survival. However, the role of BAG3 in hypoxia-induced cardiomyocyte apoptosis remains to be clarified. Here, we demonstrate that BAG3 is induced by hypoxia stimuli in cultured cardiomyocytes. BAG3 expression level was measured in H9c2 cells treated with hypoxia for 48 h. Cell proliferation and apoptosis were tested using MTT assay and Annexin V FITC-PI staining assay, respectively. The mRNA or protein expression level of BAG3, LC3-I, LC3-II, Atg5, NF-x03BA;B p65 and phosphorylated NF-x03BA;B p65 were assessed by qRT-PCR and western blot assay, respectively. Resluts: Overexpression of BAG3 inhibited cell apoptosis and promoted proliferation in hypoxia-injured H9c2 cells. Furthermore, autophagy and NF-x03BA;B were activated by BAG3 overexpression, and the NF-x03BA;B inhibitor PDTC could inhibit the activation of autophagy induced by BAG3 overexpression. In addition, the autophagy inhibitor 3-MA partly impeded the inhibitory effect of BAG3 on hypoxia-induced cardiomyocyte apoptosis. these results suggested that overexpression of BAG3 promoted cell proliferation and inhibited apoptosis by activating autophagy though the NF-x03BA;B signaling pathway in hypoxia-injured cardiomyocytes. © 2016 The Author(s) Published by S. Karger AG, Basel.

Overexpression of YB1 C-terminal domain inhibits proliferation, angiogenesis and tumorigenicity in a SK-BR-3 breast cancer xenograft mouse model.

PubMed

Shi, Jian-Hong; Cui, Nai-Peng; Wang, Shuo; Zhao, Ming-Zhi; Wang, Bing; Wang, Ya-Nan; Chen, Bao-Ping

2016-01-01

Y-box-binding protein 1 (YB1) is a multifunctional transcription factor with vital roles in proliferation, differentiation and apoptosis. In this study, we have examined the role of its C-terminal domain (YB1 CTD) in proliferation, angiogenesis and tumorigenicity in breast cancer. Breast cancer cell line SK-BR-3 was infected with GFP-tagged YB1 CTD adenovirus expression vector. An 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) proliferation assay showed that YB1 CTD decreased SK-BR-3 cell proliferation, and down-regulated cyclin B1 and up-regulated p21 levels in SK-BR-3 cells. YB1 CTD overexpression changed the cytoskeletal organization and slightly inhibited the migration of SK-BR-3 cells. YB1 CTD also inhibited secreted VEGF expression in SK-BR-3 cells, which decreased SK-BR-3-induced EA.hy926 endothelial cell angiogenesis in vitro. YB1 CTD overexpression attenuated the ability of SK-BR-3 cells to form tumours in nude mice, and decreased in vivo VEGF levels and angiogenesis in the xenografts in SK-BR-3 tumour-bearing mice. Taken together, our findings demonstrate the vital role of YB1 CTD overexpression in inhibiting proliferation, angiogenesis and tumorigenicity of breast cancer cell line SK-BR-3.

Overexpression of tropinone reductases alters alkaloid composition in Atropa belladonna root cultures.

PubMed

Richter, Ute; Rothe, Grit; Fabian, Anne-Katrin; Rahfeld, Bettina; Dräger, Birgit

2005-02-01

The medicinally applied tropane alkaloids hyoscyamine and scopolamine are produced in Atropa belladonna L. and in a small number of other Solanaceae. Calystegines are nortropane alkaloids that derive from a branching point in the tropane alkaloid biosynthetic pathway. In A. belladonna root cultures, calystegine molar concentration is 2-fold higher than that of hyoscyamine and scopolamine. In this study, two tropinone reductases forming a branching point in the tropane alkaloid biosynthesis were overexpressed in A. belladonna. Root culture lines with strong overexpression of the transcripts contained more enzyme activity of the respective reductase and enhanced enzyme products, tropine or pseudotropine. High pseudotropine led to an increased accumulation of calystegines in the roots. Strong expression of the tropine-forming reductase was accompanied by 3-fold more hyoscyamine and 5-fold more scopolamine compared with control roots, and calystegine levels were decreased by 30-90% of control. In some of the transformed root cultures, an increase of total tropane alkaloids was observed. Thus, transformation with cDNA of tropinone reductases successfully altered the ratio of tropine-derived alkaloids versus pseudotropine-derived alkaloids.

Muscle uncoupling protein 3 overexpression mimics endurance training and reduces circulating biomarkers of incomplete β-oxidation.

PubMed

Aguer, Céline; Fiehn, Oliver; Seifert, Erin L; Bézaire, Véronic; Meissen, John K; Daniels, Amanda; Scott, Kyle; Renaud, Jean-Marc; Padilla, Marta; Bickel, David R; Dysart, Michael; Adams, Sean H; Harper, Mary-Ellen

2013-10-01

Exercise substantially improves metabolic health, making the elicited mechanisms important targets for novel therapeutic strategies. Uncoupling protein 3 (UCP3) is a mitochondrial inner membrane protein highly selectively expressed in skeletal muscle. Here we report that moderate UCP3 overexpression (roughly 3-fold) in muscles of UCP3 transgenic (UCP3 Tg) mice acts as an exercise mimetic in many ways. UCP3 overexpression increased spontaneous activity (∼40%) and energy expenditure (∼5-10%) and decreased oxidative stress (∼15-20%), similar to exercise training in wild-type (WT) mice. The increase in complete fatty acid oxidation (FAO; ∼30% for WT and ∼70% for UCP3 Tg) and energy expenditure (∼8% for WT and 15% for UCP3 Tg) in response to endurance training was higher in UCP3 Tg than in WT mice, showing an additive effect of UCP3 and endurance training on these two parameters. Moreover, increases in circulating short-chain acylcarnitines in response to acute exercise in untrained WT mice were absent with training or in UCP3 Tg mice. UCP3 overexpression had the same effect as training in decreasing long-chain acylcarnitines. Outcomes coincided with a reduction in muscle carnitine acetyltransferase activity that catalyzes the formation of acylcarnitines. Overall, results are consistent with the conclusions that circulating acylcarnitines could be used as a marker of incomplete muscle FAO and that UCP3 is a potential target for the treatment of prevalent metabolic diseases in which muscle FAO is affected.

Metallothionein as potential biomarker of cadmium exposure in Persian sturgeon (Acipenser persicus).

PubMed

Shariati, Fatemeh; Esaili Sari, Abbas; Mashinchian, Ali; Pourkazemi, Mohammad

2011-10-01

Metallothionein (MT) concentration in gills, liver, and kidney tissues of Persian sturgeon (Acipenser persicus) were determined following exposure to sublethal levels of waterborne cadmium (Cd) (50, 400, and 1,000 μg l(-1)) after 1, 2, 4, and 14 days. The increases of MT from background levels were 4.6-, 3-, and 2.8-fold for kidney, liver, and gills, respectively. The results showed that MT level change in the kidney is time and concentration dependent. Also, cortisol measurement revealed elevation at the day 1 of exposure and followed by MT increase in the liver. Cd concentrations in the cytosol of experimental tissues were measured, and the results indicated that Cd levels in the cytosol of liver, kidney, and gills increased 240.71-, 32.05-, and 40.16-fold, respectively, 14 days after exposure to 1,000 μg l(-1) Cd. The accumulation of Cd in cytosol of tissues is in the order of liver > gills > kidney. Pearson correlation coefficients showed that the MT content in kidney is correlated with Cd concentration, the value of which is more than in liver and gills. Thus, kidney can be considered as a tissue indicator in A. persicus for waterborne Cd contamination.

Metallothionein: a Potential Link in the Regulation of Zinc in Nutritional Immunity.

PubMed

Rahman, Mohammad Tariqur; Karim, Muhammad Manjurul

2018-03-01

Nutritional immunity describes mechanisms for withholding essential transition metals as well as directing the toxicity of these metals against infectious agents. Zinc is one of these transition elements that are essential for both humans and microbial pathogens. At the same time, Zn can be toxic both for man and microbes if its concentration is higher than the tolerance limit. Therefore a "delicate" balance of Zn must be maintained to keep the immune cells surveilling while making the level of Zn either to starve or to intoxicate the pathogens. On the other hand, the invading pathogens will exploit the host Zn pool for its survival and replication. Apparently, different sets of protein in human and bacteria are involved to maintain their Zn need. Metallothionein (MT)-a group of low molecular weight proteins, is well known for its Zn-binding ability and is expected to play an important role in that Zn balance at the time of active infection. However, the differences in structural, functional, and molecular control of biosynthesis between human and bacterial MT might play an important role to determine the proper use of Zn and the winning side. The current review explains the possible involvement of human and bacterial MT at the time of infection to control and exploit Zn for their need.

Parkin overexpression protects retinal ganglion cells against glutamate excitotoxicity.

PubMed

Hu, Xinxin; Dai, Yi; Sun, Xinghuai

2017-01-01

To investigate the role of parkin in regulating mitochondrial homeostasis of retinal ganglion cells (RGCs) under glutamate excitotoxicity. Rat RGCs were purified from dissociated retinal tissue with a modified two-step panning protocol. Cultured RGCs were transfected with parkin using an adenovirus system. The distribution and morphology of mitochondria in the RGCs were assessed with MitoTracker. The expression and distribution of parkin and optineurin proteins were measured with western blot analysis and immunofluorescence. Cytotoxicity of RGCs was evaluated by measuring lactate dehydrogenase (LDH) activity. Mitochondrial membrane potential was determined with the JC-1 assay. The expression of Bax and Bcl-2 were measured with western blot analysis. In the presence of glutamate-induced excitotoxicity, the number of mitochondria in the axons of the RGCs was predominantly increased, and the mitochondrial membrane potential in RGCs was depolarized. The expression of the parkin and optineurin proteins was upregulated and distributed mostly in the axons of the RGCs. Overexpression of parkin stabilized the mitochondrial membrane potential of RGCs, decreased cytotoxicity and apoptosis, attenuated the expression of Bax, and promoted the expression of optineurin under glutamate excitotoxicity. Overexpression of parkin exerted a significant protective effect on cultured RGCs against glutamate excitotoxicity. Interventions to alter the parkin-mediated mitochondria pathway may be useful in protecting RGCs against excitotoxic RGC damage.

The influence of biological and environmental factors on metallothionein concentration in the blood.

PubMed

Kowalska, Katarzyna; Bizoń, Anna; Zalewska, Marta; Milnerowicz, Halina

2015-01-01

The concentration of metallothionein (MT), a low-molecular-weight protein, is regulated by many factors, primarily metals (zinc, cadmium, copper), cytokines, glucocorticoides and free radicals. These factors are determined by such aspects of human biology as gender, pregnancy and age, as well as by environmental factors including the use of oral contraceptives and cigarette smoking, all which may affect MT levels in the body. The aim of this study was to investigate the influence of these biological and environmental factors on MT concentrations in erythrocyte lysate and in plasma. MT concentrations were determined by a two-step direct enzyme-linked immunosorbent assay. Evaluation of exposure to cigarette smoking was performed by checking cotinine levels in the plasma of subjects. The studies showed higher MT concentrations in both the erythrocyte lysate and plasma of women when compared to men. Furthermore, pregnancy causes an increase of MT concentration in plasma, while oral contraceptives cause an elevated concentration of MT in erythrocyte lysate. Age impacts plasma MT concentrations in men, whereas it does not affect concentrations of MT in erythrocyte lysate. Copyright © 2014 Elsevier GmbH. All rights reserved.

Dual-mode enhancement of metallothionein protein with cell transduction and retention peptide fusion.

PubMed

Lim, Kwang Suk; Lim, Myoung-Hwa; Won, Young-Wook; Kim, Jang Kyoung; Kang, Young Cheol; Park, Eun Jeong; Chae, Ji-Won; Kim, So-Mi; Ryu, Seong-Eon; Pak, Youngmi Kim; Kim, Yong-Hee

2013-10-28

Protein transduction domains (PTDs), also known as cell-penetrating peptides (CPPs), have been developed as effective systems for delivering bio-active cargos such as proteins, genes and particles. Further improvements on cell-specific targeting, intracellular organelle targeting and intracellular retention are still necessary to enhance the therapeutic effect of PTD fusion proteins. In order to enhance the cell transduction and retention of anti-oxidative metallothionein protein (MT), MT was recombinantly fused with transcriptional activator (Tat) with or without a short peptide (sMTS) derived from mitochondria malate dehydrogenase (mMDH). Cellular uptake and retention time of fusion protein were significantly increased in the H9c2 cell by sMTS. The Tat-sMTS-MT (TMM) fusion protein protected H9c2 cells more effectively against hypoxia, hyperglycemia and combination compared with Tat-MT (TM) by reducing intracellular ROS level. It maintained the normal blood glucose level over an extended period of time in a streptozotocin-induced diabetic mouse model. PTD-sMTS-MT fusion protein has a potential to be used as a therapeutic protein for the treatment or prevention of diabetes and diabetic complications. © 2013.

Neuroprotective effects of Bcl-2 overexpression on nerve cells of rats with acute cerebral infarction.

PubMed

Zhang, H R; Peng, J H; Zhu, G Y; Xu, R X

2015-07-13

We aimed to investigate the influence of lentiviral-mediated Bcl-2 overexpression in cerebral tissues of rats with acute cerebral infarction. Forty-five rats were randomly divided into sham, model, and treatment groups. The sham and model groups were administered a control lentiviral vector via the intracranial arteries 10 days before surgery, while the treatment group received lentivirus encoding a Bcl-2 overexpression vector. We induced cerebral artery infarction using a suture-occlusion method and analyzed the cerebral expression levels of apoptosis-related genes (caspase-3, Bax), total cerebral apoptosis, range of cerebral tissue infarction, and changes in nerve cell function after 72 h. The Bcl-2-encoding lentivirus was well expressed in rat cerebral tissues. The treatment group had significantly higher expression levels of Bcl-2 than the other two groups. After cerebral infarction, the model group had significantly increased expression levels of caspase-3 and Bax protein in cerebral tissues than the sham (P < 0.05). Expression of these apoptosis-related proteins in the treatment group was obviously lower than that in the model group (P < 0.05), but significantly higher than in the sham group (P < 0.05). Compared to sham, neuronal apoptosis levels and infarction range of cerebral tissues was increased in the model and treatment groups; however, these values in the treatment group were significantly lower than that in the model group (P < 0.05). Importantly, the treatment group had significantly decreased neurological impairment scores (P < 0.05). In conclusion, Bcl-2 over-expression can decrease neuronal apoptosis in rat cerebral tissue, and thus is neuroprotective after cerebral ischemia.

Overexpression of copper transporter CTR1 in the brain barrier of North Ronaldsay sheep: implications for the study of neurodegenerative disease.

PubMed

Haywood, S; Vaillant, C

2014-01-01

Age-related regulatory failure of the brain barrier towards the influx of redox metals such as copper and iron may be associated with the pathological changes that characterize dementias such as Alzheimer's diseases (ADs) and amyotrophic lateral sclerosis (ALS). The integrity of the brain barrier to regulate copper in the brain is maintained by the complex interplay of membrane-located transporters, of which copper transporter 1 (CTR1) exerts a defining role. North Ronaldsay (NR) sheep are a primitive breed that have adapted to a copper-deficient environment by an enhanced uptake of the metal, resulting in copper overload in the liver and brain. This study reports that CTR1 is overexpressed in both the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (BCB) of adult NR sheep when compared with a domesticated breed. The excess copper is stored ultimately in astrocytes as non-injurious copper-metallothionein (MT). NR sheep have apparently retained an immature regulatory setting for CTR1 in the BBB, promoting facilitated copper uptake into the brain. This putative failure of maturation of CTR1 allows insight into the regulatory control of brain copper homeostasis, whereby the BBB and BCB act in concert to sequester excess copper and protect neurons from injury. The elevated copper content of the ageing human brain may derive from a dysregulation of CTR1 at the brain barrier, with a return to the default (immature) setting and implications for neurodegenerative disease. Copyright © 2013 Elsevier Ltd. All rights reserved.

Osteoblast Specific Overexpression of Human Interleukin-7 Rescues the Bone Mass Phenotype of Interleukin-7 Deficient Female Mice

PubMed Central

Aguila, Hector L.; Mun, Se Hwan; Kalinowski, Judith; Adams, Douglas J.; Lorenzo, Joseph A.; Lee, Sun-Kyeong

2012-01-01

Interleukin-7 is a critical cytokine for lymphoid development and a direct inhibitor of in vitro osteoclastogenesis in murine bone marrow cultures. To explore the role of IL-7 in bone, we generated transgenic mouse lines bearing the 2.3 Kb rat collagen 1A1 promoter driving the expression of human IL-7 specifically in osteoblasts. In addition we crossed these mice with IL-7 deficient mice to determine if the alterations in lymphopoiesis, bone mass and osteoclast formation observed in the IL-7 KO mice could be rescued by osteoblast-specific overexpression of IL-7. Here we show that mice overexpressing human IL-7 in the osteoblast lineage demonstrated increased trabecular bone volume in vivo by µCT and decreased osteoclast formation in vitro. Furthermore, targeted overexpression of IL-7 in osteoblasts rescued the osteopenic bone phenotype and B cell development of IL-7 KO mice but did not have an effect on T lymphopoiesis, which occurs in the periphery. The bone phenotypes in IL-7 KO mice and targeted IL-7 overexpressing mouse models were observed only in females. These results likely reflect both a direct inhibitory effects of IL-7 on osteoclastogenesis in vivo and gender specific differences in responses to IL-7. PMID:22258693

Overexpression of {alpha}-catenin increases osteoblastic differentiation in mouse mesenchymal C3H10T1/2 cells

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

Kim, Dohee; Yang, Jae-Yeon; Shin, Chan Soo, E-mail: csshin@snu.ac.kr

2009-05-15

{alpha}- and {beta}-Catenin link cadherins to the actin-based cytoskeleton at adherens junctions and regulate cell-cell adhesion. Although roles of cadherins and canonical Wnt-/{beta}-catenin-signaling in osteoblastic differentiation have been extensively studied, the role of {alpha}-catenin is not known. Murine embryonic mesenchymal stem cells, C3H10T1/2 cells, were transduced with retrovirus encoding {alpha}-catenin (MSCV-{alpha}-catenin-HA-GFP). In the presence of Wnt-3A conditioned medium or osteogenic medium ({beta}-glycerol phosphate and ascorbic acid), cells overexpressing {alpha}-catenin showed enhanced osteoblastic differentiation as measured by alkaline phosphatase (ALP) staining and ALP activity assay compared to cells transduced with empty virus (MSCV-GFP). In addition, mRNA expression of osteocalcin and Runx2more » was significantly increased compared to control. Cell aggregation assay revealed that {alpha}-catenin overexpression has significantly increased cell-cell aggregation. However, cellular {beta}-catenin levels (total, cytoplasmic-nuclear ratio) and {beta}-catenin-TCF/LEF transcriptional activity did not change by overexpression of {alpha}-catenin. Knock-down of {alpha}-catenin using siRNA decreased osteoblastic differentiation as measured by ALP assay. These results suggest that {alpha}-catenin overexpression increases osteoblastic differentiation by increasing cell-cell adhesion rather than Wnt-/{beta}-catenin-signaling.« less

Overexpression of Protochlorophyllide Oxidoreductase C Regulates Oxidative Stress in Arabidopsis

PubMed Central

Pattanayak, Gopal K.; Tripathy, Baishnab C.

2011-01-01

Light absorbed by colored intermediates of chlorophyll biosynthesis is not utilized in photosynthesis; instead, it is transferred to molecular oxygen, generating singlet oxygen (1O2). As there is no enzymatic detoxification mechanism available in plants to destroy 1O2, its generation should be minimized. We manipulated the concentration of a major chlorophyll biosynthetic intermediate i.e., protochlorophyllide in Arabidopsis by overexpressing the light-inducible protochlorophyllide oxidoreductase C (PORC) that effectively phototransforms endogenous protochlorophyllide to chlorophyllide leading to minimal accumulation of the photosensitizer protochlorophyllide in light-grown plants. In PORC overexpressing (PORCx) plants exposed to high-light, the 1O2 generation and consequent malonedialdehyde production was minimal and the maximum quantum efficiency of photosystem II remained unaffected demonstrating that their photosynthetic apparatus and cellular organization were intact. Further, PORCx plants treated with 5-aminolevulinicacid when exposed to light, photo-converted over-accumulated protochlorophyllide to chlorophyllide, reduced the generation of 1O2 and malonedialdehyde production and reduced plasma membrane damage. So PORCx plants survived and bolted whereas, the 5-aminolevulinicacid-treated wild-type plants perished. Thus, overexpression of PORC could be biotechnologically exploited in crop plants for tolerance to 1O2-induced oxidative stress, paving the use of 5-aminolevulinicacid as a selective commercial light-activated biodegradable herbicide. Reduced protochlorophyllide content in PORCx plants released the protochlorophyllide-mediated feed-back inhibition of 5-aminolevulinicacid biosynthesis that resulted in higher 5-aminolevulinicacid production. Increase of 5-aminolevulinicacid synthesis upregulated the gene and protein expression of several downstream chlorophyll biosynthetic enzymes elucidating a regulatory net work of expression of genes involved in 5

SOD1 overexpression prevents acute hyperglycemia-induced cerebral myogenic dysfunction: relevance to contralateral hemisphere and stroke outcomes

PubMed Central

Coucha, Maha; Li, Weiguo; Hafez, Sherif; Abdelsaid, Mohammed; Johnson, Maribeth H.; Fagan, Susan C.

2014-01-01

Admission hyperglycemia (HG) amplifies vascular injury and neurological deficits in acute ischemic stroke, but the mechanisms remain controversial. We recently reported that ischemia-reperfusion (I/R) injury impairs the myogenic response in both hemispheres via increased nitration. However, whether HG amplifies contralateral myogenic dysfunction and whether loss of tone in the contralateral hemisphere contributes to stroke outcomes remain to be determined. Our hypothesis was that contralateral myogenic dysfunction worsens stroke outcomes after acute hyperglycemic stroke in an oxidative stress-dependent manner. Male wild-type or SOD1 transgenic rats were injected with saline or 40% glucose solution 10 min before surgery and then subjected to 30 min of ischemia/45 min or 24 h of reperfusion. In another set of animals (n = 5), SOD1 was overexpressed only in the contralateral hemisphere by stereotaxic adenovirus injection 2–3 wk before I/R. Myogenic tone and neurovascular outcomes were determined. HG exacerbated myogenic dysfunction in contralateral side only, which was associated with infarct size expansion, increased edema, and more pronounced neurological deficit. Global and selective SOD1 overexpression restored myogenic reactivity in ipsilateral and contralateral sides, respectively, and enhanced neurovascular outcomes. In conclusion, our results show that SOD1 overexpression nullified the detrimental effects of HG on myogenic tone and stroke outcomes and that the contralateral hemisphere may be a novel target for the management of acute hyperglycemic stroke. PMID:25552308

Identification of Two Metallothioneins as Novel Inhalative Coffee Allergens Cof a 2 and Cof a 3

PubMed Central

Peters, Ulrike; Frenzel, Karsten; Brettschneider, Reinhold; Oldenburg, Marcus; Bittner, Cordula

2015-01-01

Background Dust of green coffee beans is known to be a relevant cause for occupational allergic disorders in coffee industry workers. Recently, we described the first coffee allergen (Cof a 1) establishing an allergenic potential of green coffee dust. Objective Our aim was to identify allergenic components of green coffee in order to enhance inhalative coffee allergy diagnosis. Methods A Coffea arabica pJuFo cDNA phage display library was created and screened for IgE binding with sera from allergic coffee workers. Two further coffee allergens were identified by sequence analysis, expressed in E. coli, and evaluated by Western blots. The prevalence of sensitization to recombinant Cof a 1, Cof a 2, and Cof a 3 and to commercially available extract was investigated by ELISA (enzyme-linked immunosorbent assay) respectively CAP (capacity test) screening in 18 sera of symptomatic coffee workers. Results In addition to the previously described chitinase Cof a 1, two Coffea arabica cysteine-rich metallothioneins of 9 and 7 kDa were identified and included in the IUIS Allergen Nomenclature as Cof a 2 and Cof a 3. Serum IgE antibodies to at least one of the recombinant allergens were found in 8 out of 18 symptomatic coffee workers (44%). Only 2 of the analysed sera (11%) had reacted previously to the commercial allergy test. Conclusions In addition to the previously described Cof a 1 we have identified two further coffee proteins to be type I coffee allergens (Cof a 2 and Cof a 3) which may have a relevant potential for the specific diagnosis and/or therapy of coffee allergy. PMID:25962169

β-Cell-Specific Mafk Overexpression Impairs Pancreatic Endocrine Cell Development

PubMed Central

Abdellatif, Ahmed M.; Oishi, Hisashi; Itagaki, Takahiro; Jung, Yunshin; Shawki, Hossam H.; Okita, Yukari; Hasegawa, Yoshikazu; Suzuki, Hiroyuki; El-Morsy, Salah E.; El-Sayed, Mesbah A.; Shoaib, Mahmoud B.; Sugiyama, Fumihiro; Takahashi, Satoru

2016-01-01

The MAF family transcription factors are homologs of v-Maf, the oncogenic component of the avian retrovirus AS42. They are subdivided into 2 groups, small and large MAF proteins, according to their structure, function, and molecular size. MAFK is a member of the small MAF family and acts as a dominant negative form of large MAFs. In previous research we generated transgenic mice that overexpress MAFK in order to suppress the function of large MAF proteins in pancreatic β-cells. These mice developed hyperglycemia in adulthood due to impairment of glucose-stimulated insulin secretion. The aim of the current study is to examine the effects of β-cell-specific Mafk overexpression in endocrine cell development. The developing islets of Mafk-transgenic embryos appeared to be disorganized with an inversion of total numbers of insulin+ and glucagon+ cells due to reduced β-cell proliferation. Gene expression analysis by quantitative RT-PCR revealed decreased levels of β-cell-related genes whose expressions are known to be controlled by large MAF proteins. Additionally, these changes were accompanied with a significant increase in key β-cell transcription factors likely due to compensatory mechanisms that might have been activated in response to the β-cell loss. Finally, microarray comparison of gene expression profiles between wild-type and transgenic pancreata revealed alteration of some uncharacterized genes including Pcbd1, Fam132a, Cryba2, and Npy, which might play important roles during pancreatic endocrine development. Taken together, these results suggest that Mafk overexpression impairs endocrine development through a regulation of numerous β-cell-related genes. The microarray analysis provided a unique data set of differentially expressed genes that might contribute to a better understanding of the molecular basis that governs the development and function of endocrine pancreas. PMID:26901059

MicroRNA-133 overexpression promotes the therapeutic efficacy of mesenchymal stem cells on acute myocardial infarction.

PubMed

Chen, Yueqiu; Zhao, Yunfeng; Chen, Weiqian; Xie, Lincen; Zhao, Zhen-Ao; Yang, Junjie; Chen, Yihuan; Lei, Wei; Shen, Zhenya

2017-11-25

Our study aim was to evaluate the therapeutic efficacy and mechanisms of miR-133-overexpressing mesenchymal stem cells (MSCs) on acute myocardial infarction. Rat MSCs were isolated and purified by whole bone marrow adherent culturing. After transfection with the agomir or antagomir of miR-133, MSCs were collected for assay of cell vitality, apoptosis, and cell cycle progression. At the same time, exosomes were isolated from the supernatant to analyze the paracrine miR-133. For in-vivo studies, constitutive activation of miR-133 in MSCs was achieved by lentivirus-mediated miR-133 overexpression. A rat myocardial infarction model was created by ligating the left anterior descending coronary artery, while control MSCs (vector-MSCs) or miR-133-overexpressed MSCs (miR-133-MSCs) were injected into the zone around the myocardial infarction. Subsequently, myocardial function was evaluated by echocardiography on days 7 and 28 post infarction. Finally the infarcted hearts were collected on days 7 and 28 for myocardial infarct size measurement and detection of snail 1 expression. Hypoxia-induced apoptosis of MSCs obviously reduced, along with enhanced expression of total poly ADP-ribose polymerase protein, after miR-133 agomir transfection, while the apoptosis rate increased in MSCs transfected with miR-133 antagomir. However, no change in cell viability and cell-cycle distribution was observed in control, miR-133-overexpressed, and miR-133-interfered MSCs. Importantly, rats transplanted with miR-133-MSCs displayed more improved cardiac function after acute myocardial infarction, compared with those that received vector-MSC injection. Further studies indicated that cardiac expression of snail 1 was significantly repressed by adjacent miR-133-overexpressing MSCs, and both the inflammatory level and the infarct size decreased in miR-133-MSC-injected rat hearts. miR-133-MSCs obviously improved cardiac function in a rat model of myocardial infarction. Transplantation of miR-133

Overexpression of prefoldin from the hyperthermophilic archaeum Pyrococcus horikoshii OT3 endowed Escherichia coli with organic solvent tolerance.

PubMed

Okochi, Mina; Kanie, Kei; Kurimoto, Masaki; Yohda, Masafumi; Honda, Hiroyuki

2008-06-01

Prefoldin is a jellyfish-shaped hexameric chaperone that captures a protein-folding intermediate and transfers it to the group II chaperonin for correct folding. In this work, we characterized the organic solvent tolerance of Escherichia coli cells that overexpress prefoldin and group II chaperonin from a hyperthermophilic archeaum, Pyrococcus horikoshii OT3. The colony-forming efficiency of E. coli cells overexpressing prefoldin increased by 1,000-fold and decreased the accumulation of intracellular organic solvent. The effect was impaired by deletions of the region responsible for the chaperone function of prefoldin. Therefore, we concluded that prefoldin endows E. coli cells by preventing accumulation of intracellular organic solvent through its molecular chaperone activity.

Nrf2-Dependent Induction of NQO1 in Mouse Aortic Endothelial Cells Overexpressing Catalase

PubMed Central

Lin, Xinghua; Yang, Hong; Zhou, LiChun; Guo, ZhongMao

2011-01-01

Overexpression of catalase has been shown to accelerate benzo(a)pyrene (BaP) detoxification in mouse aortic endothelial cells (MAECs ). NAD(P)H:quinone oxidoreductase1 (NQO1) is an enzyme that catalyzes BaP-quinone detoxification. Aryl hydrocarbon receptor (AhR) and nuclear factor erythroid 2-related factor-2 (Nrf2) are transcription factors that control NQO1 expression. Here, we investigated the effect of catalase overexpression on NQO1, Nrf2 and AhR expressions. The levels of NQO1 mRNA and protein were comparable in MAECs isolated from wild-type and transgenic mice that overexpress human catalase (hCatTg). BaP treatment increased NQO1 mRNA and protein levels in both groups, with a significantly greater induction in hCatTg MAECs than in wild-type cells. BaP-induced NQO1 promoter activity was dramatically higher in hCatTg MAECs than in wild-type cells. Our data also showed that the basal level of AhR and the BaP-induced level of Nrf2 were significantly higher in hCatTg MAECs than in wild-type cells. Inhibition of specificity protein-1 (Sp1) binding to the AhR promoter region by mithramycin A reversed the enhanced effect of catalase overexpression on AhR expression. Knockdown of AhR by RNA interference diminished BaP-induced expression of Nrf2 and NQO1. Knockdown of Nrf2 significantly decreased NQO1 mRNA and protein levels in cells with or without BaP treatment. NQO1 promoter activity was abrogated by mutation of the Nrf2-binding site in this promoter. In contrast, mutation of the AhR-binding site in NQO1 promoter did not affect the promoter activity. These results suggest that catalase overexpression upregulates BaP-induced NQO1 expression via enhancing the Sp1-AhR-Nrf2 signaling cascade. PMID:21569840

CCNG2 Overexpression Mediated by AKT Inhibits Tumor Cell Proliferation in Human Astrocytoma Cells.

PubMed

Zhang, Danfeng; Wang, Chunhui; Li, Zhenxing; Li, Yiming; Dai, Dawei; Han, Kaiwei; Lv, Liquan; Lu, Yicheng; Hou, Lijun; Wang, Junyu

2018-01-01

The cyclin family protein CCNG2 has an important inhibitory role in cancer initiation and progression, but the exact mechanism is still unknown. In this study, we examined the relationship between CCNG2 and the malignancy of astrocytomas and whether the AKT pathway, which is upregulated in astrocytomas, may inhibit CCNG2 expression. CCNG2 expression was found to be negatively associated with the pathological grade and proliferative activity of astrocytomas, as the highest expression was found in control brain tissue ( N  = 31), whereas the lowest expression was in high-grade glioma tissue ( N  = 31). Additionally, CCNG2 overexpression in glioma cell lines, T98G and U251 inhibited proliferation and arrested cells in the G0/G1 phase. Moreover, CCNG2 overexpression could increase glioma cells apoptosis. In contrast, AKT activity increased in glioma cells that had low CCNG2 expression. Expression of CCNG2 was higher in cells treated with the AKT kinase inhibitor MK-2206 indicating that the presence of phosphorylated AKT may inhibit the expression of CCNG2. Inhibition of AKT also led to decreased colony formation in T98G and U251 cells and knocked down of CCNG2 reversed the result. Finally, overexpression of CCNG2 in glioma cells reduced tumor volume in a murine model. To conclude, low expression of CCNG2 correlated with the severity astrocytoma and CCNG2 overexpression could induce apoptosis and inhibit proliferation. Inhibition of AKT activity increased the expression of CCNG2. The present study highlights the regulatory consequences of CCNG2 expression and AKT activity in astrocytoma tumorigenesis and the potential use of CCNG2 in anticancer treatment.

Macrophage-specific nanotechnology-driven CD163 overexpression in human macrophages results in an M2 phenotype under inflammatory conditions.

PubMed

Alvarado-Vazquez, Perla Abigail; Bernal, Laura; Paige, Candler A; Grosick, Rachel L; Moracho Vilrriales, Carolina; Ferreira, David Wilson; Ulecia-Morón, Cristina; Romero-Sandoval, E Alfonso

2017-08-01

M1 macrophages release proinflammatory factors during inflammation. They transit to an M2 phenotype and release anti-inflammatory factors to resolve inflammation. An imbalance in the transition from M1 to M2 phenotype in macrophages contributes to the development of persistent inflammation. CD163, a member of the scavenger receptor cysteine-rich family, is an M2 macrophage marker. The functional role of CD163 during the resolution of inflammation is not completely known. We postulate that CD163 contributes to the transition from M1 to M2 phenotype in macrophages. We induced CD163 gene in THP-1 and primary human macrophages using polyethylenimine nanoparticles grafted with a mannose ligand (Man-PEI). This nanoparticle specifically targets cells of monocytic origin via mannose receptors. Cells were challenged with a single or a double stimulation of lipopolysaccharide (LPS). A CD163 or empty plasmid was complexed with Man-PEI nanoparticles for cell transfections. Quantitative RT-PCR, immunocytochemistry, and ELISAs were used for molecular assessments. CD163-overexpressing macrophages displayed reduced levels of tumor necrosis factor-alpha (TNF)-α and monocytes chemoattractant protein (MCP)-1 after a single stimulation with LPS. Following a double stimulation paradigm, CD163-overexpressing macrophages showed an increase of interleukin (IL)-10 and IL-1ra and a reduction of MCP-1. This anti-inflammatory phenotype was partially blocked by an anti-CD163 antibody (effects on IL-10 and IL-1ra). A decrease in the release of TNF-α, IL-1β, and IL-6 was observed in CD163-overexpressing human primary macrophages. The release of IL-6 was blocked by an anti-CD163 antibody in the CD163-overexpressing group. Our data show that the induction of the CD163 gene in human macrophages under inflammatory conditions produces changes in cytokine secretion in favor of an anti-inflammatory phenotype. Targeting macrophages to induce CD163 using cell-directed nanotechnology is an attractive

Overexpression of PHRF1 attenuates the proliferation and tumorigenicity of non-small cell lung cancer cells.

PubMed

Wang, Yadong; Wang, Haiyu; Pan, Teng; Li, Li; Li, Jiangmin; Yang, Haiyan

2016-09-27

The aim of this study was to investigate the potential role of PHRF1 in lung tumorigenesis. Western blot analysis was used to detect the expression of proteins. Quantitative reverse transcriptase polymerase chain reaction, immunohistochemistry, soft agar assay and tumor formation assay in nude mice were applied. Cell cycle distribution was analyzed by flow cytometry. The lower level of PHRF1 mRNA was observed in human lung cancer tissues than that in paracancerous tissues. The decreased expression of PHRF1 protein was observed in H1299 and H1650 cell lines than that in 16HBE and BEAS-2B cell lines. The decreased expression of PHRF1 protein was observed in malignant 16HBE cells compared to control cells. The reduced expression of PHRF1 protein was observed in mice lung tissues treated with BaP than that in control group. Overexpression of PHRF1 inhibited H1299 cell proliferation, colony formation in vitro and growth of tumor xenograft in vivo, and arrested cell cycle in G1 phase. The decreased expression of TGIF and c-Myc proteins and the increased expression of p21 protein were observed in H1299-PHRF1 cells compared with H1299-pvoid cells. In conclusion, our findings suggest that overexpression of PHRF1 attenuated the proliferation and tumorigenicity of non-small cell lung cancer cell line of H1299.

Vitamin E confers cytoprotective effects on cardiomyocytes under conditions of heat stress by increasing the expression of metallothionein.

PubMed

Wang, Xiaowu; Dong, Wenpeng; Yuan, Binbin; Yang, Yongchao; Yang, Dongpeng; Lin, Xi; Chen, Changfu; Zhang, Weida

2016-05-01

Heat stress (HS) is commonly used to refer to the heat load that an individual is subjected to due to either metabolic heat, or environmental factors, including high temperatures and high humidity levels. HS has been reported to affect and even damage the functioning of various organs; overexposure to high temperatures and high humidity may lead to accidental deaths. It has been suggested that the cardiovascular system is primarily targeted by exposure to HS conditions; the HS-induced dysfunction of cardiomyocytes, which is characterized by mitochondrial dysfunction, may result in the development of cardiovascular diseases. The excessive production of reactive oxygen species (ROS) also participates in mitochondrial dysfunction. However, effective methods for the prevention and treatment of mitochondrial and cardiovascular dysfunction induced by exposure to HS are lacking. In the present study, we hypothesized that vitamin E (VE), an antioxidant, is capable of preventing oxidative stress and mitochondrial injury in cardiomyocytes induced by exposure to HS. The results revealed that pre‑treatment with VE increased the expression of metallothionein (MT), which has previously been reported to confer cytoprotective effects, particularly on the cardiovascular system. Pre-treatment with VE restored mitochondrial function in cardiomyocytes under conditions of HS by increasing the expression of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), nuclear respiratory factor 1 (NRF-1) and mitochondrial transcription factor A (TFAM), and by increasing adenosine triphosphate (ATP) levels. Furthermore, pre-treatment with VE decreased the production of ROS, which was induced by exposure to HS and thus exerted antioxidant effects. In addition, pre-treatment with VE attenuated oxidative stress induced by exposure to HS, as demonstrated by the increased levels of antioxidant enzymes [superoxide dismutase (SOD) and glutathione (GSH)], and by the decreased levels

Overexpression of Robo2 causes defects in the recruitment of metanephric mesenchymal cells and ureteric bud branching morphogenesis

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

Ji, Jiayao; Medical College of NanKai University, Tianjin; Li, Qinggang

2012-05-11

Highlights: Black-Right-Pointing-Pointer Overexpression of Robo2 caused reduced UB branching and glomerular number. Black-Right-Pointing-Pointer Fewer MM cells surrounding the UB after overexpression of Robo2 in vitro. Black-Right-Pointing-Pointer No abnormal Epithelial Morphology of UB or apoptosis of mm cells in the kidney. Black-Right-Pointing-Pointer Overexpression of Robo2 affected MM cells migration and caused UB deficit. Black-Right-Pointing-Pointer The reduced glomerular number can also be caused by fewer MM cells. -- Abstract: Roundabout 2 (Robo2) is a member of the membrane protein receptor family. The chemorepulsive effect of Slit2-Robo2 signaling plays vital roles in nervous system development and neuron migration. Slit2-Robo2 signaling is also importantmore » for maintaining the normal morphogenesis of the kidney and urinary collecting system, especially for the branching of the ureteric bud (UB) at the proper site. Slit2 or Robo2 mouse mutants exhibit multilobular kidneys, multiple ureters, and dilatation of the ureter, renal pelvis, and collecting duct system, which lead to vesicoureteral reflux. To understand the effect of Robo2 on kidney development, we used microinjection and electroporation to overexpress GFP-Robo2 in an in vitro embryonic kidney model. Our results show reduced UB branching and decreased glomerular number after in vitro Robo2 overexpression in the embryonic kidneys. We found fewer metanephric mesenchymal (MM) cells surrounding the UB but no abnormal morphology in the branching epithelial UB. Meanwhile, no significant change in MM proliferation or apoptosis was observed. These findings indicate that Robo2 is involved in the development of embryonic kidneys and that the normal expression of Robo2 can help maintain proper UB branching and glomerular morphogenesis. Overexpression of Robo2 leads to reduced UB branching caused by fewer surrounding MM cells, but MM cell apoptosis is not involved in this effect. Our study demonstrates

The IGF-I system component concentrations that decrease with ageing are lower in obesity in relationship to body mass index and body fat.

PubMed

Gómez, José Manuel; Maravall, Francisco Javier; Gómez, Núria; Navarro, Miguel Angel; Casamitjana, Roser; Soler, Juan

2004-04-01

The aim of this study was to investigate the GH-IGF-I axis in healthy adults and its relationship to obesity. We studied 268 subjects: 134 men and 134 women, and determined anthropometric and body composition variables. Serum total IGF-I was measured by radioimmunoassay, serum free IGF-I concentrations by enzyme linked immunosorbant assay and serum IGFBP3 concentrations by radioimmunoassay. In men, we observed a decrease in total IGF-I, free IGF-I and IGFBP-3 throughout decades. In women, the body mass index and fat mass were higher throughout decades, and we observed a similar decrease to that in men in total IGF-I, free IGF-I and IGFBP3. In men with obesity, as measured by body fat, free IGF-I concentrations were lower than those without obesity; in women with obesity, total IGF-I concentrations and free IGF-I concentrations were lower than in those with obesity. These changes were observed in relationship to obesity when the subjects were adjusted for differences in age. We showed that in controls randomly selected, the GH-IGF-I axis component concentrations that decrease with increasing age are lower in obesity, especially in women, and that this decrease is related to body mass index and body fat.

β‑catenin nuclear translocation induced by HIF‑1α overexpression leads to the radioresistance of prostate cancer.

PubMed

Luo, Yong; Li, Mingchuan; Zuo, Xuemei; Basourakos, Spyridon P; Zhang, Jiao; Zhao, Jiahui; Han, Yili; Lin, Yunhua; Wang, Yongxing; Jiang, Yongguang; Lan, Ling

2018-06-01

Hypoxia-inducible factor‑1α (HIF‑1α) is known to play crucial roles in tumor radioresistance; however, the molecular mechanisms responsible for the promotion of tumor radioresistance by HIF‑1α remain unclear. β‑catenin is known to be involved in the metastatic potential of prostate cancer (PCa). In this study, to investigate the role of HIF‑1α and β‑catenin in the radioresistance of PCa, two PCa cell lines, LNCaP and C4‑2B, were grouped as follows: Negative control (no treatment), HIF‑1α overexpression group (transfected with HIF‑1α overexpression plasmid) and β‑catenin silenced group (transfected with HIF‑1α plasmids and β‑catenin-shRNA). Cell proliferation, cell cycle, cell invasion and radiosensitivity were examined under normal or hypoxic conditions. In addition, radiosensitivity was examined in two mouse PCa models (the LNCaP orthotopic BALB/c-nu mice model and the C4‑2B subcutaneous SCID mice model). Our results revealed that in both the LNCaP and C4‑2B cells, transfection with HIF‑1α overexpression plasmid led to an enhanced β‑catenin nuclear translocation, while β‑catenin silencing inhibited β‑catenin nuclear translocation. The enhanced β‑catenin nuclear translocation induced by HIF‑1α overexpression resulted in an enhanced cell proliferation and cell invasion, an altered cell cycle distribution, decreased apoptosis, and improved non‑homologous end joining (NHEJ) repair under normal and irradiation conditions. Similar results were observed in the animal models. HIF‑1α overexpression enhanced β‑catenin nuclear translocation, which led to the activation of the β‑catenin/NHEJ signaling pathway and increased cell proliferation, cell invasion and DNA repair. These results thus suggest that HIF‑1α overexpression promotes the radioresistance of PCa cells.

Elevated levels of insulin-like growth factor (IGF)-I in serum rescue the severe growth retardation of IGF-I null mice.

PubMed

Wu, Yingjie; Sun, Hui; Yakar, Shoshana; LeRoith, Derek

2009-09-01

IGF-I plays a vital role in growth and development and acts in an endocrine and an autocrine/paracrine fashion. The purpose of the current study was to clarify whether elevated levels of IGF-I in serum can rescue the severe growth retardation and organ development and function of igf-I null mice. To address that, we overexpressed a rat igf-I transgene specifically in the liver of igf-I null mice. We found that in the total absence of tissue IGF-I, elevated levels of IGF-I in serum can support normal body size at puberty and after puberty but are insufficient to fully support the female reproductive system (evident by irregular estrous cycle, impaired development of ovarian corpus luteum, reduced number of uterine glands and endometrial hypoplasia, all leading to decreased number of pregnancies and litter size). We conclude that most autocrine/paracrine actions of IGF-I that determine organ growth and function can be compensated by elevated levels of endocrine IGF-I. However, in mice, full compensatory responses are evident later in development, suggesting that autocrine/paracrine IGF-I is critical for neonatal development. Furthermore, we show that tissue IGF-I is necessary for the development of the female reproductive system and cannot be compensated by elevated levels of serum IGF-I.

Overexpression of the active diacylglycerol acyltransferase variant transforms Saccharomyces cerevisiae into an oleaginous yeast.

PubMed

Kamisaka, Yasushi; Kimura, Kazuyoshi; Uemura, Hiroshi; Yamaoka, Masakazu

2013-08-01

Lipid production by Saccharomyces cerevisiae was improved by overexpression of the yeast diacylglycerol acyltransferase Dga1p lacking the N-terminal 29 amino acids (Dga1∆Np), which was previously found to be an active form in the ∆snf2 mutant. Overexpression of Dga1∆Np in the ∆snf2 mutant, however, did not increase lipid content as expected, which prompted us to search for a more suitable strain in which to study the role of Dga1∆Np in lipid accumulation. We found that the overexpression of Dga1∆Np in the ∆dga1 mutant effectively increased the lipid content up to about 45 % in the medium containing 10 % glucose. The high lipid content of the transformant was dependent on glucose concentration, nitrogen limitation, and active leucine biosynthesis. To better understand the effect of dga1 disruption on the ability of Dga1∆Np to stimulate lipid accumulation, the ∆dga1-1 mutant, in which the 3'-terminal 36 bp of the dga1 open reading frame (ORF) remained, and the ∆dga1-2 mutant, in which the 3'-terminal 36 bp were also deleted, were prepared with URA3 disruption cassettes. Surprisingly, the overexpression of Dga1∆Np in the ∆dga1-1 mutant had a lower lipid content than the original ∆dga1 mutant, whereas overexpression in the ∆dga1-2 mutant led to a high lipid content of about 45 %. These results indicated that deletion of the 3' terminal region of the dga1 ORF, rather than abrogation of genomic Dga1p expression, was crucial for the effect of Dga1∆Np on lipid accumulation. To investigate whether dga1 disruption affected gene expression adjacent to DGA1, we found that the overexpression of Esa1p together with Dga1∆Np in the ∆dga1 mutant reverted the lipid content to the level of the wild-type strain overexpressing Dga1∆Np. In addition, RT-qPCR analysis revealed that ESA1 mRNA expression in the ∆dga1 mutant was decreased compared to the wild-type strain at the early stages of culture, suggesting that lowered Esa1p expression is

TC-1 Overexpression Promotes Cell Proliferation in Human Non-Small Cell Lung Cancer that Can Be Inhibited by PD173074

PubMed Central

Zhang, Na; Bai, Guangzhen; Zhong, Daixing; Su, Kai; Liu, Boya; Li, Xiaofei; Wang, Yunjie; Wang, Xiaoping

2014-01-01

Thyroid cancer-1 (TC-1), a natively disordered protein, is widely expressed in vertebrates and overexpressed in many kinds of tumors. However, its exact role and regulation mechanism in human non-small cell lung cancer (NSCLC) are still unclear. In the present study, we found that TC-1 is highly expressed in NSCLC and that its aberrant expression is strongly associated with NSCLC cell proliferation. Exogenous TC-1 overexpression promotes cell proliferation, accelerates the cell G1-to-S-phase transition, and reduces apoptosis in NSCLC. The knockdown of TC-1, however, inhibits NSCLC cell proliferation, cycle transition, and apoptosis resistance. Furthermore, we also demonstrated that PD173074, which functions as an inhibitor of the TC-1 in NSCLC, decreases the expression of TC-1 and inhibits TC-1 overexpression mediated cell proliferation in vitro and in vivo. Nevertheless, the inhibition function of PD173074 on NSCLC cell proliferation was eliminated in cells with TC-1 knockdown. These results suggest that PD173074 plays a significant role in TC-1 overexpression mediated NSCLC cell proliferation and may be a potential intervention target for the prevention of cell proliferation in NSCLC. PMID:24941347

Overexpression of the growth arrest-specific homeobox gene Gax inhibits proliferation, migration, cell cycle progression, and apoptosis in serum-induced vascular smooth muscle cells.

PubMed

Zheng, H; Xue, S; Hu, Z L; Shan, J G; Yang, W G

2014-03-24

The Gax gene has been implicated in a variety of cell-developmental and biological processes, and aberrant Gax expression is linked to many diseases. In this study, to provide important insights for Gax-based gene therapy in vein graft restenosis and its anti-restenotic mechanism, we used rabbit vascular smooth muscle cells (VSMCs) to investigate the effects of Gax overexpression on proliferation, migration, cell cycle, and apoptosis in a serum-stimulated culture. Rabbit VSMC lines that stably overexpressed Gax were established by transfection with recombinant adenoviral vector Ad5-Gax. The effect of Gax overexpression on in vitro serum-induced VSMCs proliferation, migration, cell cycle, and apoptosis was assessed by MTT, wound healing, and flow cytometry assays, respectively. To investigate the effect of Gax overexpression on PCNA and MMP-2 in serum-induced VSMCs, immunocytochemistry, RT-PCR, and gelatin zymography were performed. The results clearly showed that Gax overexpression decreases PCNA expression in serum-induced VSMCs. Gax overexpression also significantly inhibited cell proliferation by blocking entry into the S-phase of the cell cycle, promoted cell apoptosis, and reduced cell migration activity by downregulating MMP-2 release and activity. These findings indicate that Gax would be an optimal target gene for gene therapy to treat vein graft restenosis.

Increased abscisic acid levels in transgenic maize overexpressing AtLOS5 mediated root ion fluxes and leaf water status under salt stress

PubMed Central

Zhang, Juan; Yu, Haiyue; Zhang, Yushi; Wang, Yubing; Li, Maoying; Zhang, Jiachang; Duan, Liusheng; Zhang, Mingcai; Li, Zhaohu

2016-01-01

Abscisic acid (ABA) is a vital cellular signal in plants, and effective ABA signalling is pivotal for stress tolerance. AtLOS5 encoding molybdenum cofactor sulphurase is a key regulator of ABA biosynthesis. Here, transgenic AtLOS5 plants were generated to explore the role of AtLOS5 in salt tolerance in maize. AtLOS5 overexpression significantly up-regulated the expression of ZmVp14-2, ZmAO, and ZmMOCO, and increased aldehyde oxidase activities, which enhanced ABA accumulation in transgenic plants under salt stress. Concurrently, AtLOS5 overexpression induced the expression of ZmNHX1, ZmCBL4, and ZmCIPK16, and enhanced the root net Na+ efflux and H+ influx, but decreased net K+ efflux, which maintained a high cytosolic K+/Na+ ratio in transgenic plants under salt stress. However, amiloride or sodium orthovanadate could significantly elevate K+ effluxes and decrease Na+ efflux and H+ influx in salt-treated transgenic roots, but the K+ effluxes were inhibited by TEA, suggesting that ion fluxes regulated by AtLOS5 overexpression were possibly due to activation of Na+/H+ antiport and K+ channels across the plasma membrane. Moreover, AtLOS5 overexpression could up-regulate the transcripts of ZmPIP1:1, ZmPIP1:5, and ZmPIP2:4, and enhance root hydraulic conductivity. Thus transgenic plants had higher leaf water potential and turgor, which was correlated with greater biomass accumulation under salt stress. Thus AtLOS5 overexpression induced the expression of ABA biosynthetic genes to promote ABA accumulation, which activated ion transporter and PIP aquaporin gene expression to regulate root ion fluxes and water uptake, thus maintaining high cytosolic K+ and Na+ homeostasis and better water status in maize exposed to salt stress. PMID:26743432

Overexpression of O-polysaccharide chain length regulators in Gram-negative bacteria using the Wzx-/Wzy-dependent pathway enhances production of defined modal length O-polysaccharide polymers for use as haptens in glycoconjugate vaccines.

PubMed

Hegerle, N; Bose, J; Ramachandran, G; Galen, J E; Levine, M M; Simon, R; Tennant, S M

2018-03-30

O-polysaccharide (OPS) molecules are protective antigens for several bacterial pathogens, and have broad utility as components of glycoconjugate vaccines. Variability in the OPS chain length is one obstacle towards further development of these vaccines. Introduction of sizing steps during purification of OPS molecules of suboptimal or of mixed lengths introduces additional costs and complexity while decreasing the final yield. The overall goal of this study was to demonstrate the utility of engineering Gram-negative bacteria to produce homogenous O-polysaccharide populations that can be used as the basis of carbohydrate vaccines by overexpressing O-polysaccharide chain length regulators of the Wzx-/Wzy-dependent pathway. The O-polysaccharide chain length regulators wzzB and fepE from Salmonella Typhimurium I77 and wzz2 from Pseudomonas aeruginosa PAO1 were cloned and expressed in the homologous organism or in other Gram-negative bacteria. Overexpression of these Wzz proteins in the homologous organism significantly increased the proportion of long or very long chain O-polysaccharides. The same observation was made when wzzB was overexpressed in Salmonella Paratyphi A and Shigella flexneri, and wzz2 was overexpressed in two other strains of P. aeruginosa. Overexpression of Wzz proteins in Gram-negative bacteria using the Wzx/Wzy-dependant pathway for lipopolysaccharide synthesis provides a genetic method to increase the production of an O-polysaccharide population of a defined size. The methods presented herein represent a cost-effective and improved strategy for isolating preferred OPS vaccine haptens, and could facilitate the further use of O-polysaccharides in glycoconjugate vaccine development. © 2018 The Society for Applied Microbiology.

YB-1 overexpression promotes a TGF-β1-induced epithelial–mesenchymal transition via Akt activation

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

Ha, Bin; Lee, Eun Byul; Cui, Jun

2015-03-06

The Y-box binding protein-1 (YB-1) is a transcription/translation regulatory protein, and the expression thereof is associated with cancer aggressiveness. In the present study, we explored the regulatory effects of YB-1 during the transforming growth factor-β1 (TGF-β1)-induced epithelial-to-mesenchymal transition (EMT) in lung adenocarcinoma cells. Downregulation of YB-1 increased E-cadherin promoter activity, and upregulation of YB-1 decreased promoter activity, suggesting that the YB-1 level may be correlated with the EMT. TGF-β1 induced YB-1 expression, and TGF-β1 translocated cytosolic YB-1 into the nucleus. YB-1 overexpression promoted TGF-β1-induced downregulation of epithelial markers, upregulation of mesenchymal markers, and cell migration. Moreover, YB-1 overexpression enhanced themore » expression of E-cadherin transcriptional repressors via TGF-β1-induced Akt activation. Our findings afford new insights into the role played by YB-1 in the TGF-β1 signaling pathway. - Highlights: • YB-1 regulates E-cadherin expression in A549 cells. • TGF-β1 induces upregulating and nuclear localization of YB-1. • YB-1 overexpression accelerates TGF-β1-induced EMT and cell migration. • YB-1 regulates Snail and Slug expression via Akt activation.« less

CTT1 overexpression increases life span of calorie-restricted Saccharomyces cerevisiae deficient in Sod1.

PubMed

Rona, Germana; Herdeiro, Ricardo; Mathias, Cristiane Juliano; Torres, Fernando Araripe; Pereira, Marcos Dias; Eleutherio, Elis

2015-06-01

Studies using different organisms revealed that reducing calorie intake, without malnutrition, known as calorie restriction (CR), increases life span, but its mechanism is still unkown. Using the yeast Saccharomyces cerevisiae as eukaryotic model, we observed that Cu, Zn-superoxide dismutase (Sod1p) is required to increase longevity, as well as to confer protection against lipid and protein oxidation under CR. Old cells of sod1 strain also presented a premature induction of apoptosis. However, when CTT1 (which codes for cytosolic catalase) was overexpressed, sod1 and WT strains showed similar survival rates. Furthermore, CTT1 overexpression decreased lipid peroxidation and delayed the induction of apoptotic process. Superoxide is rapidly converted to hydrogen peroxide by superoxide dismutase, but it also undergoes spontaneous dismutation albeit at a slower rate. However, the quantity of peroxide produced from superoxide in this way is two-fold higher. Peroxide degradation, catalyzed by catalase, is of vital importance, because in the presence of a reducer transition metal peroxide is reduced to the highly reactive hydroxyl radical, which reacts indiscriminately with most cellular constituents. These findings might explain why overexpression of catalase was able to overcome the deficiency of Sod1p, increasing life span in response to CR.

Lifespan and Stress Resistance in Drosophila with Overexpressed DNA Repair Genes

PubMed Central

Shaposhnikov, Mikhail; Proshkina, Ekaterina; Shilova, Lyubov; Zhavoronkov, Alex; Moskalev, Alexey

2015-01-01

DNA repair declines with age and correlates with longevity in many animal species. In this study, we investigated the effects of GAL4-induced overexpression of genes implicated in DNA repair on lifespan and resistance to stress factors in Drosophila melanogaster. Stress factors included hyperthermia, oxidative stress, and starvation. Overexpression was either constitutive or conditional and either ubiquitous or tissue-specific (nervous system). Overexpressed genes included those involved in recognition of DNA damage (homologs of HUS1, CHK2), nucleotide and base excision repair (homologs of XPF, XPC and AP-endonuclease-1), and repair of double-stranded DNA breaks (homologs of BRCA2, XRCC3, KU80 and WRNexo). The overexpression of different DNA repair genes led to both positive and negative effects on lifespan and stress resistance. Effects were dependent on GAL4 driver, stage of induction, sex, and role of the gene in the DNA repair process. While the constitutive/neuron-specific and conditional/ubiquitous overexpression of DNA repair genes negatively impacted lifespan and stress resistance, the constitutive/ubiquitous and conditional/neuron-specific overexpression of Hus1, mnk, mei-9, mus210, and WRNexo had beneficial effects. This study demonstrates for the first time the effects of overexpression of these DNA repair genes on both lifespan and stress resistance in D. melanogaster. PMID:26477511

Metallothionein as a Scavenger of Free Radicals - New Cardioprotective Therapeutic Agent or Initiator of Tumor Chemoresistance?

PubMed

Heger, Zbynek; Rodrigo, Miguel Angel Merlos; Krizkova, Sona; Ruttkay-Nedecky, Branislav; Zalewska, Marta; Del Pozo, Elena Maria Planells; Pelfrene, Aurelie; Pourrut, Bertrand; Stiborova, Marie; Eckschlager, Tomas; Emri, Gabriella; Kizek, Rene; Adam, Vojtech

2016-01-01

Cardiotoxicity is a serious complication of anticancer therapy by anthracycline antibiotics. Except for intercalation into DNA/RNA structure, inhibition of DNA-topoisomerase and histone eviction from chromatin, the main mechanism of their action is iron-mediated formation of various forms of free radicals, which leads to irreversible damage to cancer cells. The most serious adverse effect of anthracyclines is, thus, cardiomyopathy leading to congestive heart failure, which is caused by the same mechanisms. Here, we briefly summarize the basic types of free radicals formed by anthracyclines and the main processes how to scavenge them. From these, the main attention is paid to metallothioneins. These low-molecular cysteine-rich proteins are introduced and their functions and properties are reviewed. Further, their role in detoxification of metals and drugs is discussed. Based on these beneficial roles, their use as a new therapeutic agent against oxidative stress and for cardioprotection is critically evaluated with respect to their ability to increase chemoresistance against some types of commonly used cytostatics.

Limb-bud and Heart Overexpression Inhibits the Proliferation and Migration of PC3M Cells.

PubMed

Liu, Qicai; Li, Ermao; Huang, Long; Cheng, Minsheng; Li, Li

2018-01-01

Background: The limb-bud and heart gene ( LBH ) was discovered in the early 21st century and is specifically expressed in the mouse embryonic limb and heart development. Increasing evidences have indicated that LBH not only plays an important role in embryo development, it is also closely correlated with the occurance and progression of many tumors. However, its function in prostate cancer (PCa) is still not well understood. Here, we explored the effects of LBH on the proliferation and migration of the PCa cell line PC3M. Methods: LBH expression in tissues and cell lines of PCa was detected by immunohistochemistry and Western blotting. Lentivirus was used to transduct the LBH gene into the PC3M cells. Stable LBH-overexpressing PC3M-LBH cells and PC3M-NC control cells were obtained via puromycin screening. Cell proliferation was examined using the 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Cell cycle distribution and apoptosis rate were investigated using flow cytometry. Cell migration was studied using the Transwell assay. Results: LBH expression level was down-regulated in 3 different PCa cell lines, especially in PC3M cells, compared with the normal prostate epithelial cells(RWPE-1). Cell lines of LBH-upregulated PC3M-LBH and PC3M-NC control were successfully constructed. Significantly increased LBH expression level and decreased cyclin D1 and cyclin E2 expression level was found in PC3M-LBH cells as compared to the PC3M-NC cells. The overexpression of LBH significantly inhibited PC3M cell proliferation in vitro and tumor growth in nude mice. LBH overexpression in PC3M cell, also induced cell cycle G0/G1 phase arrest and decreased the migration of PC3M cells. Conclusions : Our results reveal that LBH expression is down-regulated in the tissue and cell lines of PCa. LBH overexpression inhibits PC3M cell proliferation and tumor growth by inducing cell cycle arrest through down-regulating cyclin D1and cyclin E2 expression. LBH might

Metallothionein Isoform Expression in Benign and Malignant Thyroid Lesions.

PubMed

Wojtczak, Beata; Pula, Bartosz; Gomulkiewicz, Agnieszka; Olbromski, Mateusz; Podhorska-Okolow, Marzena; Domoslawski, Paweł; Bolanowski, Marek; Daroszewski, Jacek; Dziegiel, Piotr

2017-09-01

Metallothioneins (MTs) are involved in numerous cell processes such as binding and transport of zinc and copper ions, differentiation, proliferation and apoptosis, therefore contributing to carcinogenesis. Scarce data exist on their expression in benign and malignant lesions of the thyroid. mRNA expression of functional isoforms of MT genes (MT1A, MT1B, MT1E, MT1F, MT1G, MT1H, MT1X, MT2A, MT4) was studied in 17 nodular goiters (NG), 12 follicular adenomas (FA) and 26 papillary thyroid carcinomas (PTC). One-way ANOVA revealed significant differences in mRNA expression levels of MT1A (p<0.05), MT1E (p<0.005), MT1F (p<0.0001), MT1G (p<0.005), MT1X (p<0.0005) and MT2A (p<0.005) in the analyzed samples. Post hoc analysis confirmed a significantly lower expression of MT1A mRNA in PTC compared to NG (p<0.05). Significant down-regulation was also noted for other MT isoforms in PTC in comparison to NG: MT1E (p<0.05), MT1F (p<0.0001), MT1G (p<0.005), MT1X (p<0.0005) and MT2A (p<0.05). In addition, significant down-regulation of MT1F and MT1G in FA compared to NG was observed (p<0.005 and p<0.05, respectively). Expression of functional MT isoforms may contribute to thyroid carcinogenesis and potentially serve as a diagnostic marker in distinguishing benign and malignant lesions. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Rhenium and technetium tricarbonyl, {M(CO)3} (+) (M = Tc, Re), binding to mammalian metallothioneins: new insights into chemical and radiopharmaceutical implications.

PubMed

Lecina, Joan; Palacios, Òscar; Atrian, Sílvia; Capdevila, Mercè; Suades, Joan

2015-04-01

This paper deals with the binding of the four mammalian metallothioneins (MTs) to the organometallic metal fragment {fac-M(CO)3}(+) (M = (99)Tc, Re), which is highly promising for the preparation of second-generation radiopharmaceuticals. The study of the transmetallation reaction between zinc and rhenium in Zn7-MT1 by means of UV-vis and CD spectroscopy demonstrated the incorporation of the {fac-Re(CO)3}(+) fragment to the MTs. This reaction should be performed at 70 °C to accelerate the reaction rate, a result that is consistent with the reported reactivity of the rhenium fragment. ESI-TOF MS demonstrated the formation of mixed-metal species as Zn6,{Re(CO)3}-MT, Zn6,{Re(CO)3}2-MT, and Zn5,{Re(CO)3}3-MT, as well as the different reactivity of the four MT isoforms. Hence, Zn-MT3 showed the highest reactivity, in agreement with its high Cu-thionein character, whereas Zn-MT2 exhibited the lowest reactivity, in line with its high Zn-thionein character. The reactivity of the Zn-loaded forms of MT1 and MT4 is intermediate between those of MT3 and MT2. The study of the binding of the {fac-(99)Tc(CO)3}(+) fragment to MTs showed a significant and very interesting different reactivity in relation to rhenium. The transmetallation reaction is much more effective with technetium than with rhenium and significant amounts of mixed Zn x ,{(99)Tc(CO)3} y -MT species were formed with the four MT isoforms whereas only MT3 rendered similar amounts of rhenium derivatives. The results obtained in this study support the possible use of technetium for labelling mammalian metallothioneins and also for possible radiopharmaceutical applications.

Overexpression of Telomerase Reverse Transcriptase Induces Autism-like Excitatory Phenotypes in Mice.

PubMed

Kim, Ki Chan; Rhee, Jeehae; Park, Jong-Eun; Lee, Dong-Keun; Choi, Chang Soon; Kim, Ji-Woon; Lee, Han-Woong; Song, Mi-Ryoung; Yoo, Hee Jeong; Chung, ChiHye; Shin, Chan Young

2016-12-01

In addition to its classical role as a regulator of telomere length, recent reports suggest that telomerase reverse transcriptase (TERT) plays a role in the transcriptional regulation of gene expression such as β-catenin-responsive pathways. Silencing or over-expression of TERT in cultured NPCs demonstrated that TERT induced glutamatergic neuronal differentiation. During embryonic brain development, expression of transcription factors involved in glutamatergic neuronal differentiation was increased in mice over-expressing TERT (TERT-tg mice). We observed increased expression of NMDA receptor subunits and phosphorylation of α-CaMKII in TERT-tg mice. TERT-tg mice showed autism spectrum disorder (ASD)-like behavioral phenotypes as well as lowered threshold against electrically induced seizure. Interestingly, the NMDA receptor antagonist memantine restored behavioral abnormalities in TERT-tg mice. Consistent with the alteration in excitatory/inhibitory (E/I) ratio, TERT-tg mice showed autism-like behaviors, abnormal synaptic organization, and function in mPFC suggesting the role of altered TERT activity in the manifestation of ASD, which is further supported by the significant association of certain SNPs in Korean ASD patients.

Long-term insulin-like growth factor-I expression in skeletal muscles attenuates the enhanced in vitro proliferation ability of the resident satellite cells in transgenic mice

NASA Technical Reports Server (NTRS)

Chakravarthy, M. V.; Fiorotto, M. L.; Schwartz, R. J.; Booth, F. W.

2001-01-01

Insulin-like growth factor-I (IGF-I) overexpression for 1-month in mouse skeletal muscle increases satellite cell proliferation potential. However, it is unknown whether this beneficial enhancement by IGF-I expression would persist over a longer-term duration in aged mice. This is an important issue to address if a prolonged course of IGF-I is to be used clinically in muscle-wasting conditions where satellite cells may become limiting. Using the IGF-I transgenic (IGF-I Tg) mouse that selectively expresses the IGF-I transgene in striated muscles, we found that 18-months of continuous IGF-I overexpression led to a loss in the enhanced in vitro proliferative capacity of satellite cells from Tg skeletal muscles. Also 18-month-old IGF-I Tg satellite cells lost the enhanced BrdU incorporation, greater pRb and Akt phosphorylations, and decreased p27(Kip1) levels initially observed in cells from 1-month-old IGF-I Tg mice. The levels of those biochemical markers reverted to similar values seen in the 18-months WT littermates. These findings, therefore, suggest that there is no further beneficial effect on enhancing satellite cell proliferation ability with persistent long-term expression of IGF-I in skeletal muscles of these transgenic mice.

Over-expression of mammalian sialidase NEU3 reduces Newcastle disease virus entry and propagation in COS7 cells.

PubMed

Anastasia, Luigi; Holguera, Javier; Bianchi, Anna; D'Avila, Francesca; Papini, Nadia; Tringali, Cristina; Monti, Eugenio; Villar, Enrique; Venerando, Bruno; Muñoz-Barroso, Isabel; Tettamanti, Guido

2008-03-01

The paramyxovirus Newcastle Disease Virus (NDV) binds to sialic acid-containing glycoconjugates, sialoglycoproteins and sialoglycolipids (gangliosides) of host cell plasma membrane through its hemagglutinin-neuraminidase (sialidase) HN glycoprotein. We hypothesized that the modifications of the cell surface ganglioside pattern determined by over-expression of the mammalian plasma-membrane associated, ganglioside specific, sialidase NEU3 would affect the virus-host cell interactions. Using COS7 cells as a model system, we observed that over-expression of the murine MmNEU3 did not affect NDV binding but caused a marked reduction in NDV infection and virus propagation through cell-cell fusion. Moreover, since GD1a was greatly reduced in COS7 cells following NEU3-over-expression, we added [(3)H]-labelled GD1a to COS7 cells under conditions that block intralysosomal metabolic processing, and we observed a marked increase of GD1a cleavage to GM1 during NDV infection, indicating a direct involvement of the virus sialidase and host cell GD1a in NDV infectivity. Therefore, the decrease of GD1a in COS7 cell membrane upon MmNEU3 over-expression is likely to be instrumental to NDV reduced infection. Evidence was also provided for the preferential association of NDV-HN at 4 degrees C to detergent resistant microdomains (DRMs) of COS7 cells plasma membranes.

RAC1b overexpression stimulates proliferation and NF-kB-mediated anti-apoptotic signaling in thyroid cancer cells

PubMed Central

Faria, Márcia; Matos, Paulo; Pereira, Teresa; Cabrera, Rafael; Cardoso, Bruno A.; Bugalho, Maria João

2017-01-01

Overexpression of tumor-associated RAC1b has been recently highlighted as one of the most promising targets for therapeutic intervention in colon, breast, lung and pancreatic cancer. RAC1b is a hyperactive variant of the small GTPase RAC1 and has been recently shown to be overexpressed in a subset of papillary thyroid carcinomas associated with unfavorable outcome. Using the K1 PTC derived cell line as an in vitro model, we observed that both RAC1 and RAC1b were able to induce a significant increase on NF-kB and cyclin D1 reporter activity. A clear p65 nuclear localization was found in cells transfected with RAC1b-WT, confirming NF-kB canonical pathway activation. Consistently, we observed a RAC1b-mediated decrease in IκBα (NF-kB inhibitor) protein levels. Moreover, we show that RAC1b overexpression stimulates G1/S progression and protects thyroid cells against induced apoptosis, the latter through a process involving the NF-kB pathway. Present data support previous findings suggesting an important role for RAC1b in the development of follicular cell-derived thyroid malignancies and point out NF-kB activation as one of the molecular mechanisms associated with the pro-tumorigenic advantage of RAC1b overexpression in thyroid carcinomas. PMID:28234980

Overexpression and deletion of phospholipid transfer protein reduce HDL mass and cholesterol efflux capacity but not macrophage reverse cholesterol transport[S

PubMed Central

Kuwano, Takashi; Bi, Xin; Cipollari, Eleonora; Yasuda, Tomoyuki; Lagor, William R.; Szapary, Hannah J.; Tohyama, Junichiro; Millar, John S.; Billheimer, Jeffrey T.; Lyssenko, Nicholas N.; Rader, Daniel J.

2017-01-01

Phospholipid transfer protein (PLTP) may affect macrophage reverse cholesterol transport (mRCT) through its role in the metabolism of HDL. Ex vivo cholesterol efflux capacity and in vivo mRCT were assessed in PLTP deletion and PLTP overexpression mice. PLTP deletion mice had reduced HDL mass and cholesterol efflux capacity, but unchanged in vivo mRCT. To directly compare the effects of PLTP overexpression and deletion on mRCT, human PLTP was overexpressed in the liver of wild-type animals using an adeno-associated viral (AAV) vector, and control and PLTP deletion animals were injected with AAV-null. PLTP overexpression and deletion reduced plasma HDL mass and cholesterol efflux capacity. Both substantially decreased ABCA1-independent cholesterol efflux, whereas ABCA1-dependent cholesterol efflux remained the same or increased, even though preβ HDL levels were lower. Neither PLTP overexpression nor deletion affected excretion of macrophage-derived radiocholesterol in the in vivo mRCT assay. The ex vivo and in vivo assays were modified to gauge the rate of cholesterol efflux from macrophages to plasma. PLTP activity did not affect this metric. Thus, deviations in PLTP activity from the wild-type level reduce HDL mass and ex vivo cholesterol efflux capacity, but not the rate of macrophage cholesterol efflux to plasma or in vivo mRCT. PMID:28137768

Overexpression of NGF ameliorates ethanol neurotoxicity in the developing cerebellum.

PubMed

Heaton, M B; Mitchell, J J; Paiva, M

2000-11-05

Transgenic mice overexpressing NGF in the central nervous system under the control of the glial fibrillary acidic protein (GFAP) promoter were exposed to ethanol via vapor inhalation on postnatal days 4 and 5 (P4-5), the period of maximal cerebellar Purkinje cell sensitivity to ethanol. Wild-type controls were exposed in a similar manner. There were no differences in body weight or size following these procedures, but the transgenic brain weights at this age were significantly greater than wild-type controls. In the wild-type animals, a significant 33.3% ethanol-mediated loss of Purkinje cells in lobule I was detected via unbiased three-dimensional stereological counting on P5. In the GFAP-NGF transgenic animals, however, the 17.6% difference in Purkinje cell number in control and ethanol-exposed animals was not significant. There was a similar difference in Purkinje cell density in both groups, which did reach statistical significance (-32.7% in wild-type ethanol-treated animals, -17% in transgenic ethanol-exposed animals). These results suggest that endogenous overexpression of neurotrophic factors, which have previously been shown to protect against ethanol neurotoxicity in culture, can serve a similar protective function in the intact animal. Copyright 2000 John Wiley & Sons, Inc.

Metallothionein quantification in clams by reversed-phase high-performance liquid chromatography coupled to fluorescence detection after monobromobimane derivatization.

PubMed

Alhama, José; Romero-Ruiz, Antonio; López-Barea, Juan

2006-02-24

In this paper, we describe a highly specific, sensitive and reliable method for total metallothionein (MT) quantification by RP-HPLC coupled to fluorescence detection following reaction with monobromobimane of thiols from metal-depleted MT after heat-denaturation of extracts in the presence of sodium dodecyl sulphate (SDS). SDS-polyacrylamide gel electrophoresis (SDS-PAGE) confirmed the identity of the peak resolved (t(R)=16.44) with MT: a highly fluorescent protein of approximately 8.3 kDa, in agreement with the high thiol content and low MT size. Other heat-resistant and Cys-containing proteins of 35 kDa were efficiently separated. The new method was successfully used to quantify MT content in digestive gland of clams from southern Spanish coastal sites with different metal levels, and is proposed as a tool for using MTs as biomarker in monitoring programmes.

Trace-elements, methylmercury and metallothionein levels in Magellanic penguin (Spheniscus magellanicus) found stranded on the Southern Brazilian coast.

PubMed

Kehrig, Helena A; Hauser-Davis, Rachel A; Seixas, Tércia G; Fillmann, Gilberto

2015-07-15

Magellanic penguins have been reported as good biomonitors for several types of pollutants, including trace-elements. In this context, selenium (Se), total mercury, methylmercury, inorganic mercury (Hg(inorg)), cadmium (Cd) and lead (Pb), as well as metallothionein (MT) levels, were evaluated in the feathers, liver and kidney of juvenile Magellanic penguins found stranded along the coast of Southern Brazil. The highest concentrations of all trace-elements and methylmercury were found in internal organs. Concentrations of Cd and Se in feathers were extremely low in comparison with their concentrations in soft tissues. The results showed that both Se and MT are involved in the detoxification of trace-elements (Cd, Pb and Hg(inorg)) since statistically significant relationships were found in liver. Conversely, hepatic Se was shown to be the only detoxifying agent for methylmercury. Copyright © 2015 Elsevier Ltd. All rights reserved.

Isocitrate dehydrogenase 1 is downregulated during early skin tumorigenesis which can be inhibited by overexpression of manganese superoxide dismutase.

PubMed

Robbins, Delira; Wittwer, Jennifer A; Codarin, Sarah; Circu, Magdalena L; Aw, Tak Yee; Huang, Ting-Ting; Van Remmen, Holly; Richardson, Arlan; Wang, David B; Witt, Stephan N; Klein, Ronald L; Zhao, Yunfeng

2012-08-01

Isocitrate dehydrogenase 1 (IDH1), a cytosolic enzyme that converts isocitrate to alpha-ketoglutarate, has been shown to be dysregulated during tumorigenesis. However, at what stage of cancer development IDH1 is dysregulated and how IDH1 may affect cell transformation and tumor promotion during early stages of cancer development are unclear. We used a skin cell transformation model and mouse skin epidermal tissues to study the role of IDH1 in early skin tumorigenesis. Our studies demonstrate that both the tumor promoter TPA and UVC irradiation decreased expression and activity levels of IDH1, not IDH2, in the tumor promotable JB6 P+ cell model. Skin epidermal tissues treated with dimethylbenz[α]anthracene/TPA also showed decreases in IDH1 expression and activity. In non-promotable JB6 P-cells, IDH1 was upregulated upon TPA treatment, whereas IDH2 was maintained at similar levels with TPA treatment. Interestingly, IDH1 knockdown enhanced, whereas IDH1 overexpression suppressed, TPA-induced cell transformation. Finally, manganese superoxide dismutase overexpression suppressed tumor promoter induced decreases in IDH1 expression and mitochondrial respiration, while intracellular alpha-ketoglutarate levels were unchanged. These results suggest that decreased IDH1 expression in early stage skin tumorigenesis is highly correlated with tumor promotion. In addition, oxidative stress might contribute to IDH1 inactivation, because manganese superoxide dismutase, a mitochondrial antioxidant enzyme, blocked decreases in IDH1 expression and activity. © 2012 Japanese Cancer Association.

DKK3 Overexpression Increases the Malignant Properties of Head and Neck Squamous Cell Carcinoma Cells.

PubMed

Katase, Naoki; Nishimatsu, Shin-Ichiro; Yamauchi, Akira; Yamamura, Masahiro; Terada, Kumiko; Itadani, Masumi; Okada, Naoko; Hassan, Nur Mohammad Monsur; Nagatsuka, Hitoshi; Ikeda, Tohru; Nohno, Tsutomu; Fujita, Shuichi

2018-01-19

DKK3, a member of the dickkopf Wnt signaling pathway inhibitor family, is believed to be a tumor suppressor because of its reduced expression in cancer cells. However, our previous studies have revealed that DKK3 expression is predominantly observed in head and neck/oral squamous cell carcinoma (HNSCC/OSCC). Interestingly, HNSCC/OSCC patients with DKK3 expression showed a high rate of metastasis and poorer survival, and siRNA-mediated knockdown of DKK3 in HNSCC-derived cancer cell lines resulted in reduced cellular migration and invasion. From these data, it was hypothesized that DKK3 might exert an oncogenic function specific to HNSCC. In the present research, the DKK3 overexpression model was established, and its influences were investigated, together with molecular mechanism studies. The DKK3 expression profile in cancer cell lines was investigated, including HNSCC/OSCC, esophageal, gastric, colorectal, pancreatic, prostatic, and lung cancers. DKK3 overexpression was performed in HNSCC-derived cells by transfection of expression plasmid. The effects of DKK3 overexpression were assessed on cellular proliferation, migration, invasion, and in vivo tumor growth. The molecular mechanism of DKK3 overexpression was investigated by Western blotting and microarray analysis. DKK3 overexpression significantly elevated cellular proliferation, migration, and invasion, as well as increased mRNA expression of cyclin D1 and c-myc. However, reporter assays did not show TCF/LEF activation, suggesting that the increased malignant property of cancer cells was not driven by the Wnt/β-catenin pathway. For the investigation of the pathways/molecules in DKK3-mediated signals, the Western blot analyses revealed that phosphorylation of Akt (S473) and c-Jun (Ser63) was elevated. The application of a PI3K kinase inhibitor, LY294002, on HSC-3 DKK3 cells significantly decreased tumor cell proliferation, migration, and invasion. From these results, we demonstrated that DKK3 might contribute

Ursodeoxycholic acid inhibits overexpression of P-glycoprotein induced by doxorubicin in HepG2 cells.

PubMed

Komori, Yuki; Arisawa, Sakiko; Takai, Miho; Yokoyama, Kunihiro; Honda, Minako; Hayashi, Kazuhiko; Ishigami, Masatoshi; Katano, Yoshiaki; Goto, Hidemi; Ueyama, Jun; Ishikawa, Tetsuya; Wakusawa, Shinya

2014-02-05

The hepatoprotective action of ursodeoxycholic acid (UDCA) was previously suggested to be partially dependent on its antioxidative effect. Doxorubicin (DOX) and reactive oxygen species have also been implicated in the overexpression of P-glycoprotein (P-gp), which is encoded by the MDR1 gene and causes antitumor multidrug resistance. In the present study, we assessed the effects of UDCA on the expression of MDR1 mRNA, P-gp, and intracellular reactive oxygen species levels in DOX-treated HepG2 cells and compared them to those of other bile acids. DOX-induced increases in reactive oxygen species levels and the expression of MDR1 mRNA were inhibited by N-acetylcysteine, an antioxidant, and the DOX-induced increase in reactive oxygen species levels and DOX-induced overexpression of MDR1 mRNA and P-gp were inhibited by UDCA. Cells treated with UDCA showed improved rhodamine 123 uptake, which was decreased in cells treated with DOX alone. Moreover, cells exposed to DOX for 24h combined with UDCA accumulated more DOX than that of cells treated with DOX alone. Thus, UDCA may have inhibited the overexpression of P-gp by suppressing DOX-induced reactive oxygen species production. Chenodeoxycholic acid (CDCA) also exhibited these effects, whereas deoxycholic acid and litocholic acid were ineffective. In conclusion, UDCA and CDCA had an inhibitory effect on the induction of P-gp expression and reactive oxygen species by DOX in HepG2 cells. The administration of UDCA may be beneficial due to its ability to prevent the overexpression of reactive oxygen species and acquisition of multidrug resistance in hepatocellular carcinoma cells. Copyright © 2013 Elsevier B.V. All rights reserved.

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

Hoadley, J.E.; Leinart, A.S.; Cousins, R.J.

Intestinal 65Zn transport and metallothionein levels were examined in rats fed zinc-adequate and zinc-deficient diets and in rats subjected to an overnight fast. 65Zn uptake by intestines perfused with 1.5 microM 65Zn was greater in both zinc-deficient and fasted groups than in the control group. Mucosal retention of 65Zn was also greater in the zinc-deficient group but not in the fasted group. The greater 65Zn uptake in the fasted group was associated with a compartment that readily released 65Zn back into the lumen. Kinetic analysis of the rate of 65Zn transfer to the vascular space (absorption) showed that 65Zn absorptionmore » involved approximately 3% of mucosal 65Zn in a 40-min perfusion period. The half-life (t1/2) of this mucosal 65Zn rapid transport pool corresponded directly to changes in intestinal metallothionein levels. Both metallothionein and t1/2 were higher in the fasted group and lower in the zinc-deficient group than in controls. While the rate of 65Zn transport from this rapid transport pool decreased with increasing metallothionein level, the predicted pool size increased when the metallothionein level was elevated by fasting. These results indicate that the rate of zinc absorption is inversely related to intestinal metallothionein levels, but the portion of mucosal 65Zn available for absorption is directly related to intestinal metallothionein.« less

Metabolic Compensation of Fitness Costs Is a General Outcome for Antibiotic-Resistant Pseudomonas aeruginosa Mutants Overexpressing Efflux Pumps.

PubMed

Olivares Pacheco, Jorge; Alvarez-Ortega, Carolina; Alcalde Rico, Manuel; Martínez, José Luis

2017-07-25

It is generally assumed that the acquisition of antibiotic resistance is associated with a fitness cost. We have shown that overexpression of the MexEF-OprN efflux pump does not decrease the fitness of a resistant Pseudomonas aeruginosa strain compared to its wild-type counterpart. This lack of fitness cost was associated with a metabolic rewiring that includes increased expression of the anaerobic nitrate respiratory chain when cells are growing under fully aerobic conditions. It was not clear whether this metabolic compensation was exclusive to strains overexpressing MexEF-OprN or if it extended to other resistant strains that overexpress similar systems. To answer this question, we studied a set of P. aeruginosa mutants that independently overexpress the MexAB-OprM, MexCD-OprJ, or MexXY efflux pumps. We observed increased expression of the anaerobic nitrate respiratory chain in all cases, with a concomitant increase in NO 3 consumption and NO production. These efflux pumps are proton/substrate antiporters, and their overexpression may lead to intracellular H + accumulation, which may in turn offset the pH homeostasis. Indeed, all studied mutants showed a decrease in intracellular pH under anaerobic conditions. The fastest way to eliminate the excess of protons is by increasing oxygen consumption, a feature also displayed by all analyzed mutants. Taken together, our results support metabolic rewiring as a general mechanism to avoid the fitness costs derived from overexpression of P. aeruginosa multidrug efflux pumps. The development of drugs that block this metabolic "reaccommodation" might help in reducing the persistence and spread of antibiotic resistance elements among bacterial populations. IMPORTANCE It is widely accepted that the acquisition of resistance confers a fitness cost in such a way that in the absence of antibiotics, resistant populations will be outcompeted by susceptible ones. Based on this assumption, antibiotic cycling regimes have been

The Functions of Metallothionein and ZIP and ZnT Transporters: An Overview and Perspective

PubMed Central

Kimura, Tomoki; Kambe, Taiho

2016-01-01

Around 3000 proteins are thought to bind zinc in vivo, which corresponds to ~10% of the human proteome. Zinc plays a pivotal role as a structural, catalytic, and signaling component that functions in numerous physiological processes. It is more widely used as a structural element in proteins than any other transition metal ion, is a catalytic component of many enzymes, and acts as a cellular signaling mediator. Thus, it is expected that zinc metabolism and homeostasis have sophisticated regulation, and elucidating the underlying molecular basis of this is essential to understanding zinc functions in cellular physiology and pathogenesis. In recent decades, an increasing amount of evidence has uncovered critical roles of a number of proteins in zinc metabolism and homeostasis through influxing, chelating, sequestrating, coordinating, releasing, and effluxing zinc. Metallothioneins (MT) and Zrt- and Irt-like proteins (ZIP) and Zn transporters (ZnT) are the proteins primarily involved in these processes, and their malfunction has been implicated in a number of inherited diseases such as acrodermatitis enteropathica. The present review updates our current understanding of the biological functions of MTs and ZIP and ZnT transporters from several new perspectives. PMID:26959009

Overexpression of human kynurenine-3-monooxygenase protects against 3-hydroxykynurenine-mediated apoptosis through bidirectional nonlinear feedback.

PubMed

Wilson, K; Auer, M; Binnie, M; Zheng, X; Pham, N T; Iredale, J P; Webster, S P; Mole, D J

2016-04-14

Kynurenine 3-monooxygenase (KMO) is a critical regulator of inflammation. The preferred KMO substrate, kynurenine, is converted to 3-hydroxykynurenine (3HK), and this product exhibits cytotoxicity through mechanisms that culminate in apoptosis. Here, we report that overexpression of human KMO with orthotopic localisation to mitochondria creates a metabolic environment during which the cell exhibits increased tolerance for exogenous 3HK-mediated cellular injury. Using the selective KMO inhibitor Ro61-8048, we show that KMO enzyme function is essential for cellular protection. Pan-caspase inhibition with Z-VAD-FMK confirmed apoptosis as the mode of cell death. By defining expression of pathway components upstream and downstream of KMO, we observed alterations in other key kynurenine pathway components, particularly tryptophan-2,3-dioxygenase upregulation, through bidirectional nonlinear feedback. KMO overexpression also increased expression of inducible nitric oxide synthase (iNOS). These changes in gene expression are functionally relevant, because siRNA knockdown of the pathway components kynureninase and quinolinate phosphoribosyl transferase caused cells to revert to a state of susceptibility to 3HK-mediated apoptosis. In summary, KMO overexpression, and importantly KMO activity, have metabolic repercussions that fundamentally affect resistance to cell stress.

Overexpression of human kynurenine-3-monooxygenase protects against 3-hydroxykynurenine-mediated apoptosis through bidirectional nonlinear feedback

PubMed Central

Wilson, K; Auer, M; Binnie, M; Zheng, X; Pham, N T; Iredale, J P; Webster, S P; Mole, D J

2016-01-01

Kynurenine 3-monooxygenase (KMO) is a critical regulator of inflammation. The preferred KMO substrate, kynurenine, is converted to 3-hydroxykynurenine (3HK), and this product exhibits cytotoxicity through mechanisms that culminate in apoptosis. Here, we report that overexpression of human KMO with orthotopic localisation to mitochondria creates a metabolic environment during which the cell exhibits increased tolerance for exogenous 3HK-mediated cellular injury. Using the selective KMO inhibitor Ro61-8048, we show that KMO enzyme function is essential for cellular protection. Pan-caspase inhibition with Z-VAD-FMK confirmed apoptosis as the mode of cell death. By defining expression of pathway components upstream and downstream of KMO, we observed alterations in other key kynurenine pathway components, particularly tryptophan-2,3-dioxygenase upregulation, through bidirectional nonlinear feedback. KMO overexpression also increased expression of inducible nitric oxide synthase (iNOS). These changes in gene expression are functionally relevant, because siRNA knockdown of the pathway components kynureninase and quinolinate phosphoribosyl transferase caused cells to revert to a state of susceptibility to 3HK-mediated apoptosis. In summary, KMO overexpression, and importantly KMO activity, have metabolic repercussions that fundamentally affect resistance to cell stress. PMID:27077813

MicroRNA268 Overexpression Affects Rice Seedling Growth under Cadmium Stress.

PubMed

Ding, Yanfei; Wang, Yi; Jiang, Zhihua; Wang, Feijuan; Jiang, Qiong; Sun, Junwei; Chen, Zhixiang; Zhu, Cheng

2017-07-26

MicroRNAs (miRNAs) are 21-24-nucleotide-long RNAs that function as ubiquitous post-transcriptional regulators of gene expression in plants and animals. Increasing evidence points to the important role of miRNAs in plant responses to abiotic and biotic stresses. Cadmium (Cd) is a nonessential heavy metal highly toxic to plants. Although many genes encoding metal transporters have been characterized, the mechanisms for the regulation of the expression of the heavy-metal transporter genes are largely unknown. In this study, we found that the expression of miR268 in rice was significantly induced under Cd stress. By contrast, expression of natural resistance-associated macrophage protein 3 (NRAMP3), a target gene of miR268, was dramatically decreased by Cd treatment. Overexpression of miR268 inhibited rice seedling growth under Cd stress. The transgenic miR268-overexpressing plant leaves contained increased levels of hydrogen peroxide and malondialdehyde, and their seedlings accumulated increased levels of Cd when compared to those in wild-type plants. These results indicate that miR268 acts as a negative regulator of rice's tolerance to Cd stress. Thus, miRNA-guided regulation of gene expression plays an important role in plant responses to heavy-metal stress.

The HGF Receptor c-Met Is Overexpressed in Esophageal Adenocarcinoma1

PubMed Central

Herrera, Luis J; El-Hefnawy, Talal; Queiroz de Oliveira, Pierre E; Raja, Siva; Finkelstein, Sydney; Gooding, William; Luketich, James D; Godfrey, Tony E; Hughes, Steven J

2005-01-01

Abstract The hepatocyte growth factor (HGF) receptor, Met, has established oncogenic properties; however, its expression and function in esophageal adenocarcinoma (EA) remain poorly understood. We aimed to determine the expression and potential alterations in Met expression in EA. Met expression was investigated in surgical specimens of EA, Barrett's esophagus (BE), and normal esophagus (NE) using immunohistochemistry (IHC) and quantitative reverse transcriptase polymerase chain reaction. Met expression, phosphorylation, and the effect of COX-2 inhibition on expression were examined in EA cell lines. IHC demonstrated intense Met immunoreactivity in all (100%) EA and dysplastic BE specimens. In contrast, minimal immunostaining was observed in BE without dysplasia or NE specimens. Met mRNA and protein levels were increased in three EA cell lines, and Met protein was phosphorylated in the absence of serum. Sequence analysis found the kinase domain of c-met to be wild type in all three EA cell lines. HGF mRNA expression was identified in two EA cell lines. In COX-2-overexpressing cells, COX-2 inhibition decreased Met expression. Met is consistently overexpressed in EA surgical specimens and in three EA cell lines. Met dysregulation occurs early in Barrett's dysplasia to adenocarcinoma sequence. Future study of Met inhibition as a potential biologic therapy for EA is warranted. PMID:15720819

Intestine-specific overexpression of IL-10 improves survival in polymicrobial sepsis.

PubMed

Rajan, Saju; Vyas, Dinesh; Clark, Andrew T; Woolsey, Cheryl A; Clark, Jessica A; Hotchkiss, Richard S; Buchman, Timothy G; Coopersmith, Craig M

2008-04-01

Targeted IL-10 therapy improves survival in preclinical models of critical illness, and intestine-specific IL-10 decreases inflammation in models of chronic Inflammatory disease. We therefore sought to determine whether intestine-specific overexpression of IL-10 would improve survival in sepsis. Transgenic mice that overexpress IL-10 in their gut epithelium (Fabpi-IL-10 mice) and wild-type (WT) littermates (n = 127) were subjected to cecal ligation and puncture with a 27-gauge needle. The 7-day survival rate was 45% in transgenic animals and 30% in WT animals (P < or = 0.05). Systemic levels of IL-10 were undetectable in both groups of animals under basal conditions and were elevated to a similar degree in septic animals regardless of whether they expressed the transgene. Local parameter of injury, including gut epithelial apoptosis, intestinal permeability, peritoneal lavage cytokines, and stimulated cytokines from intraepithelial lymphocytes, were similar between transgenic and WT mice. However, in stimulated splenocytes, proinflammatory cytokines monocyte chemoattractant protein 1 (189 +/- 43 vs. 40 +/- 8 pg/mL) and IL-6 (116 +/- 28 vs. 34 +/- 9 pg/mL) were lower in Fabpi-IL-10 mice than WT littermates despite the intestine-specific nature of the transgene (P < 0.05). Cytokine levels were similar in blood and bronchoalveolar lavage fluid between the 2 groups, as were circulating LPS levels. Transgenic mice also had lower white blood cell counts associated with lower absolute neutrophil counts (0.5 +/- 0.1 vs. 1.0 +/- 0.2 10(3)/mm3; P < 0.05). These results indicate that gut-specific overexpression of IL-10 improves survival in a murine model of sepsis, and interactions between the intestinal epithelium and the systemic immune system may play a role in conferring this survival advantage.

Intestine-specific overexpression of IL-10 improves survival in polymicrobial sepsis

PubMed Central

Rajan, Saju; Vyas, Dinesh; Clark, Andrew T; Woolsey, Cheryl A; Clark, Jessica A; Hotchkiss, Richard S; Buchman, Timothy G; Coopersmith, Craig M

2007-01-01

Targeted Interleukin (IL)-10 therapy improves survival in preclinical models of critical illness, and intestine-specific IL-10 decreases inflammation in models of chronic inflammatory disease. We therefore sought to determine whether intestine-specific overexpression of IL-10 would improve survival in sepsis. Transgenic mice that overexpress IL-10 in their gut epithelium (Fabpi-IL-10 mice) and wild type (WT) littermates (n=127) were subjected to cecal ligation and puncture with a 27-gauge needle. Seven-day survival was 45% in transgenic animals and 30% in WT animals (p≤0.05). Systemic levels of IL-10 were undetectable in both groups of animals under basal conditions and were elevated to a similar degree in septic animals, regardless of whether they expressed the transgene. Local parameters of injury including gut epithelial apoptosis, intestinal permeability, peritoneal lavage cytokines and stimulated cytokines from intraepithelial lymphocytes were similar between transgenic and wildtype mice. However, in stimulated splenocytes, pro-inflammatory cytokines MCP-1 (189 ± 43 pg/ml vs. 40 ± 8 pg/ml) and IL-6 (116 ± 28 pg/ml vs. 34 ± 9 pg/ml) were lower in Fabpi-IL-10 mice than WT littermates despite the intestine-specific nature of the transgene (p<0.05). Cytokine levels were similar in blood and bronchoalveolar lavage fluid between the two groups as were circulating LPS levels. Transgenic mice also had lower white blood cell counts, associated with lower absolute neutrophil counts (0.5 ± 0.1 103/mm3 vs. 1.0 ± 0.2 103/mm3, p<0.05). These results indicate that gut-specific overexpression of IL-10 improves survival in a murine model of sepsis, and interactions between the intestinal epithelium and the systemic immune system may play a role in conferring this survival advantage. PMID:17998890

Overexpression of membrane metalloendopeptidase inhibits substance P stimulation of cholangiocarcinoma growth.

PubMed

Meng, Fanyin; DeMorrow, Sharon; Venter, Julie; Frampton, Gabriel; Han, Yuyan; Francis, Heather; Standeford, Holly; Avila, Shanika; McDaniel, Kelly; McMillin, Matthew; Afroze, Syeda; Guerrier, Micheleine; Quezada, Morgan; Ray, Debolina; Kennedy, Lindsey; Hargrove, Laura; Glaser, Shannon; Alpini, Gianfranco

2014-05-01

Substance P (SP) promotes cholangiocyte growth during cholestasis by activating its receptor, NK1R. SP is a proteolytic product of tachykinin (Tac1) and is deactivated by membrane metalloendopeptidase (MME). This study aimed to evaluate the functional role of SP in the regulation of cholangiocarcinoma (CCA) growth. NK1R, Tac1, and MME expression and SP secretion were assessed in human CCA cells and nonmalignant cholangiocytes. The proliferative effects of SP (in the absence/presence of the NK1R inhibitor, L-733,060) and of L-733,060 were evaluated. In vivo, the effect of L-733,060 treatment or MME overexpression on tumor growth was evaluated by using a xenograft model of CCA in nu/nu nude mice. The expression of Tac1, MME, NK1R, PCNA, CK-19, and VEGF-A was analyzed in the resulting tumors. Human CCA cell lines had increased expression of Tac1 and NK1R, along with reduced levels of MME compared with nonmalignant cholangiocytes, resulting in a subsequent increase in SP secretion. SP treatment increased CCA cell proliferation in vitro, which was blocked by L-733,060. Treatment with L-733,060 alone inhibited CCA proliferation in vitro and in vivo. Xenograft tumors derived from MME-overexpressed human Mz-ChA-1 CCA cells had a slower growth rate than those derived from control cells. Expression of PCNA, CK-19, and VEGF-A decreased, whereas MME expression increased in the xenograft tumors treated with L-733,060 or MME-overexpressed xenograft tumors compared with controls. The study suggests that SP secreted by CCA promotes CCA growth via autocrine pathway. Blockade of SP secretion and NK1R signaling may be important for the management of CCA.

Overexpression of a type-I isopentenyl pyrophosphate isomerase of Artemisia annua in the cytosol leads to high arteannuin B production and artemisinin increase.

PubMed

Ma, Dongming; Li, Gui; Alejos-Gonzalez, Fatima; Zhu, Yue; Xue, Zhen; Wang, Aimin; Zhang, Hui; Li, Xing; Ye, Hechun; Wang, Hong; Liu, Benye; Xie, De-Yu

2017-08-01

We recently characterized a gene-terpene network that is associated with artemisinin biosynthesis in self-pollinated (SP) Artemisia annua, an effective antimalarial plant. We hypothesize that an alteration of gene expression in the network may improve the production of artemisinin and its precursors. In this study, we cloned an isopentenyl pyrophosphate isomerase (IPPI) cDNA, AaIPPI1, from Artemisia annua (Aa). The full-length cDNA encodes a type-I IPPI containing a plastid transit peptide (PTP) at its amino terminus. After the removal of the PTP, the recombinant truncated AaIPPI1 isomerized isopentenyl pyrophosphate (IPP) to dimethyl allyl pyrophosphate (DMAPP) and vice versa. The steady-state equilibrium ratio of IPP/DMAPP in the enzymatic reactions was approximately 1:7. The truncated AaIPPI1 was overexpressed in the cytosol of the SP A. annua variety. The leaves of transgenic plants produced approximately 4% arteannuin B (g g -1 , dry weight, dw) and 0.17-0.25% artemisinin (g g -1 , dw), the levels of which were significantly higher than those in the leaves of wild-type plants. In addition, transgenic plants showed an increase in artemisinic acid production of more than 1% (g g -1 , dw). In contrast, isoprene formation was significantly reduced in transgenic plants. These results provide evidence that overexpression of AaIPPI1 in the cytosol can lead to metabolic alterations of terpenoid biosynthesis, and show that these transgenic plants have the potential to yield high production levels of arteannuin B as a new precursor source for artemisinin. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

Chorein interacts with α-tubulin and histone deacetylase 6, and overexpression preserves cell viability during nutrient deprivation in human embryonic kidney 293 cells.

PubMed

Sasaki, Natsuki; Nakamura, Masayuki; Kodama, Akiko; Urata, Yuka; Shiokawa, Nari; Hayashi, Takehiro; Sano, Akira

2016-11-01

The autophagy pathway has recently been implicated in several neurodegenerative diseases. Recently, it was reported that chorein-depleted cells showed accumulation of autophagic markers and impaired autophagic flux. Here, we demonstrate that chorein overexpression preserves cell viability from starvation-induced cell death in human embryonic kidney 293 (HEK293) cells. Subsequent coimmunoprecipitation and reverse coimmunoprecipitation assays using extracts from chorein that stably overexpressed HEK293 cells revealed that chorein interacts with α-tubulin and histone deacetylase 6, a known α-tubulin deacetylater and central component of basal autophagy. Indeed, acetylated α-tubulin immunoreactivity was significantly decreased in chorein that stably overexpressed HEK293 cells. These results suggest that chorein/histone deacetylase 6/α-tubulin interactions may play an important role in starvation-induced cell stress, and their disruption may be one of the molecular pathogenic mechanisms of chorea-acanthocytosis.-Sasaki, N., Nakamura, M., Kodama, A., Urata, Y., Shiokawa, N., Hayashi, T., Sano, A. Chorein interacts with α-tubulin and histone deacetylase 6, and overexpression preserves cell viability during nutrient deprivation in human embryonic kidney 293 cells. © FASEB.

Escitalopram alters gene expression and HPA axis reactivity in rats following chronic overexpression of corticotropin-releasing factor from the central amygdala

PubMed Central

Flandreau, Elizabeth I.; Bourke, Chase H.; Ressler, Kerry J.; Vale, Wylie W.; Nemeroff, Charles B.; Owens, Michael J.

2013-01-01

Summary We have previously demonstrated that viral-mediated overexpression of corticotropin-releasing factor (CRF) within the central nucleus of the amygdala (CeA) reproduces many of the behavioral and endocrine consequences of chronic stress. The present experiment sought to determine whether administration of the selective serotonin reuptake inhibitor (SSRI) escitalopram reverses the adverse effects of CeA CRF overexpression. In a 2 × 2 design, adult male rats received bilateral infusions of a control lentivirus or a lentivirus in which a portion of the CRF promoter is used to drive increased expression of CRF peptide. Four weeks later, rats were then implanted with an Alzet minipump to deliver vehicle or 10 mg/kg/day escitalopram for a 4-week period of time. The defensive withdrawal (DW) test of anxiety and the sucrose-preference test (SPT) of anhedonia were performed both before and after pump implantation. Additional post-implant behavioral tests included the elevated plus maze (EPM) and social interaction (SI) test. Following completion of behavioral testing, the dexamethasone/CRF test was performed to assess HPA axis reactivity. Brains were collected and expression of HPA axis-relevant transcripts were measured using in situ hybridization. Amygdalar CRF overexpression increased anxiety-like behavior in the DW test at week eight, which was only partially prevented by escitalopram. In both CRF-overexpressing and control groups, escitalopram decreased hippocampal CRF expression while increasing hypothalamic and hippocampal expression of the glucocorticoid receptor (GR). These gene expression changes were associated with a significant decrease in HPA axis reactivity in rats treated with escitalopram. Interestingly, escitalopram increased the rate of weight gain only in rats overexpressing CRF. Overall these data support our hypothesis that amygdalar CRF is critical in anxiety-like behavior; because the antidepressant was unable to reverse behavioral

Overexpression of the muscle-specific protein, melusin, protects from cardiac ischemia/reperfusion injury.

PubMed

Penna, Claudia; Brancaccio, Mara; Tullio, Francesca; Rubinetto, Cristina; Perrelli, Maria-Giulia; Angotti, Carmelina; Pagliaro, Pasquale; Tarone, Guido

2014-07-01

Melusin is a muscle-specific protein which interacts with β1 integrin cytoplasmic domain and acts as chaperone protein. Its overexpression induces improved resistance to cardiac overload delaying left ventricle dilation and reducing the occurrence of heart failure. Here, we investigated possible protective effect of melusin overexpression against acute ischemia/reperfusion (I/R) injury with or without Postconditioning cardioprotective maneuvers. Melusin transgenic (Mel-TG) mice hearts were subjected to 30-min global ischemia followed by 60-min reperfusion. Interestingly, infarct size was reduced in Mel-TG mice hearts compared to wild-type (WT) hearts (40.3 ± 3.5 % Mel-TG vs. 59.5 ± 3.8 % WT hearts; n = 11 animals/group; P < 0.05). The melusin protective effect was also demonstrated by measuring LDH release, which was 50 % lower in Mel-TG compared to WT. Mel-TG hearts had a higher baseline level of AKT, ERK1/2 and GSK3β phosphorylation, and displayed increased phospho-kinases level after I/R compared to WT mice. Post-ischemic Mel-TG hearts displayed also increased levels of the anti-apoptotic factor phospho-BAD. Importantly, pharmacological inhibition of PI3K/AKT (Wortmannin) and ERK1/2 (U0126) pathways abrogated the melusin protective effect. Notably, HSP90, a chaperone known to protect heart from I/R injury, showed high levels of expression in the heart of Mel-TG mice suggesting a possible collaboration of this molecule with AKT/ERK/GSK3β pathways in the melusin-induced protection. Postconditioning, known to activate AKT/ERK/GSK3β pathways, significantly reduced IS and LDH release in WT hearts, but had no additive protective effects in Mel-TG hearts. These findings implicate melusin as an enhancer of AKT and ERK pathways and as a novel player in cardioprotection from I/R injury.

Overexpression of Klotho suppresses liver cancer progression and induces cell apoptosis by negatively regulating wnt/β-catenin signaling pathway.

PubMed

Sun, Huidong; Gao, Yanchao; Lu, Kemei; Zhao, Guimei; Li, Xuehua; Li, Zhu; Chang, Hong

2015-10-24

Klotho is a discovered aging suppressor gene, and its overexpression in mice extends the life span of the animal. Recently, Klotho is also identified as a tumor suppressor gene in variety of tumors; however, the potential role and the antitumor mechanism remain unclarified in liver cancers. RT-PCR and western blotting analysis were used to detect the expression of Klotho, β-catenin, C-myc, and Cyclin D1. MTT assay was used to detect the survival rates of HepG2 and SMMC-7721 cells. Colony formation assay was used to test the proliferation ability in Klotho transfected cells. FACS was used to detect the cell apoptosis rate in different groups. The results showed that lower expression of Klotho were found in liver cancer cell lines than the immortalized liver cell L02. Also, MTT assay results found that overexpression or recombinant Klotho administration suppressed the proliferation of liver cancer cells HepG2 and SMMC-7721. Moreover, the colony formation assay results showed that the number of colonies was significantly lower in the cells with transfection with pCMV-Klotho than the controls. Thus, functional analysis demonstrated that Klotho expression inhibited the proliferation of liver cancer cells and Klotho worked as an important antitumor gene in tumor progression. Next, the mechanism was partly clarified that Klotho expression induced cell apoptosis in HepG2 and SMMC-7721 cells, and this phenomenon was mainly involved in the Wnt/β-catenin signaling pathway. The western blotting analysis revealed that overexpression or recombinant administration of Klotho obviously decreased the expression levels of β-catenin, C-myc, and Cyclin D1 in HepG2 cells. Most importantly, the antitumor mechanism for Klotho due to that overexpression of Klotho not only decreased the endogenous β-catenin levels but also inhibited the nuclear translocation of β-catenin to delay the cell cycle progression. Klotho was a tumor suppressor gene, and overexpression of Klotho suppressed the

Mic60/Mitofilin Overexpression Alters Mitochondrial Dynamics and Attenuates Vulnerability of Dopaminergic Cells to Dopamine and Rotenone

PubMed Central

Van Laar, Victor S.; Berman, Sarah B.; Hastings, Teresa G.

2017-01-01

Mitochondrial dysfunction has been implicated in Parkinson’s disease (PD) neuropathology. Mic60, also known as mitofilin, is a protein of the inner mitochondrial membrane and a key component of the mitochondrial contact site and cristae junction organizing system (MICOS). Mic60 is critical for maintaining mitochondrial membrane structure and function. We previously demonstrated that mitochondrial Mic60 protein is susceptible to both covalent modification and loss in abundance following exposure to dopamine quinone. In this study, we utilized neuronally-differentiated SH-SY5Y and PC12 dopaminergic cell lines to examine the effects of altered Mic60 levels on mitochondrial function and cellular vulnerability in response to PD-relevant stressors. Short hairpin RNA (shRNA)-mediated knockdown of endogenous Mic60 protein in neuronal SH-SY5Y cells significantly potentiated dopamine-induced cell death, which was rescued by co-expressing shRNA-insensitive Mic60. Conversely, in PC12 and SH-SY5Y cells, Mic60 overexpression significantly attenuated both dopamine- and rotenone-induced cell death as compared to controls. Mic60 overexpression in SH-SY5Y cells was also associated with increased mitochondrial respiration, and, following rotenone exposure, increased spare respiratory capacity. Mic60 knockdown cells exhibited suppressed respiration and, following rotenone treatment, decreased spare respiratory capacity. Mic60 overexpression also affected mitochondrial fission/fusion dynamics. PC12 cells overexpressing Mic60 exhibited increased mitochondrial interconnectivity. Further, both PC12 cells and primary rat cortical neurons overexpressing Mic60 displayed suppressed mitochondrial fission and increased mitochondrial length in neurites. These results suggest that altering levels of Mic60 in dopaminergic neuronal cells significantly affects both mitochondrial homeostasis and cellular vulnerability to the PD-relevant stressors dopamine and rotenone, carrying implications for PD

Overexpression of Jatropha Gibberellin 2-oxidase 6 (JcGA2ox6) Induces Dwarfism and Smaller Leaves, Flowers and Fruits in Arabidopsis and Jatropha

PubMed Central

Hu, Ying-Xiong; Tao, Yan-Bin; Xu, Zeng-Fu

2017-01-01

Gibberellins (GAs) are plant hormones that play fundamental roles in plant growth and development. Gibberellin 2-oxidase (GA2ox) plays a direct role in determining the levels of bioactive GAs by catalyzing bioactive GAs or their immediate precursors to inactive forms. In this study, a GA2ox gene, designated JcGA2ox6, was isolated from Jatropha curcas. JcGA2ox6 is expressed in all tissues of adult Jatropha, with the highest expression level in male flowers and the lowest expression level in young leaves. Overexpression of JcGA2ox6 in Arabidopsis resulted in a typical dwarf phenotype, along with late flowering, smaller leaves and flowers, shorter siliques and smaller seeds. Similarly, when JcGA2ox6 was overexpressed in Jatropha, the transgenic plants exhibited a dwarf phenotype with dark-green leaves and smaller inflorescences, flowers, fruits and seeds. However, the flowering time of Jatropha was not affected by overexpression of JcGA2ox6, unlike that in the transgenic Arabidopsis. Moreover, the number of flowers per inflorescence, the weight of 10 seeds and the seed oil content were significantly decreased in transgenic Jatropha. The results indicated that overexpression of JcGA2ox6 had a great impact on the vegetative and reproductive growth of transgenic Jatropha. Furthermore, we found that the dwarf phenotype of transgenic Jatropha was caused by a decrease in endogenous bioactive GA4, which was correlated with the degree of dwarfism. PMID:29312375

Transplantation of mesenchymal stem cells overexpressing IL10 attenuates cardiac impairments in rats with myocardial infarction.

PubMed

Meng, Xin; Li, Jianping; Yu, Ming; Yang, Jian; Zheng, Minjuan; Zhang, Jinzhou; Sun, Chao; Liang, Hongliang; Liu, Liwen

2018-01-01

Mesenchymal stem cell (MSC) has been well known to exert therapeutic potential for patients with myocardial infarction (MI). In addition, interleukin-10 (IL10) could attenuate MI through suppressing inflammation. Thus, the combination of MSC implantation with IL10 delivery may extend health benefits to ameliorate cardiac injury after MI. Here we established overexpression of IL10 in bone marrow-derived MSC through adenoviral transduction. Cell viability, apoptosis, and IL10 secretion under ischemic challenge in vitro were examined. In addition, MSC was transplanted into the injured hearts in a rat model of MI. Four weeks after the MI induction, MI, cardiac functions, apoptotic cells, and inflammation cytokines were assessed. In response to in vitro oxygen-glucose deprivation (OGD), IL10 overexpression in MSC (Ad.IL10-MSC) enhanced cell viability, decreased apoptosis, and increased IL10 secretion. Consistently, the implantation of Ad.IL10-MSCs into MI animals resulted in more reductions in myocardial infarct size, cardiac impairment, and cell apoptosis, compared to the individual treatments of either MSC or IL10 administration. Moreover, the attenuation of both systemic and local inflammations was most prominent for Ad.IL10-MSC treatment. IL10 overexpression and MSC may exert a synergistic anti-inflammatory effect to alleviate cardiac injury after MI. © 2017 Wiley Periodicals, Inc.

Overexpression of Arabidopsis FLOWERING LOCUS T (FT) gene improves floral development in cassava (Manihot esculenta, Crantz).

PubMed

Adeyemo, O Sarah; Chavarriaga, Paul; Tohme, Joe; Fregene, Martin; Davis, Seth J; Setter, Tim L

2017-01-01

Cassava is a tropical storage-root crop that serves as a worldwide source of staple food for over 800 million people. Flowering is one of the most important breeding challenges in cassava because in most lines flowering is late and non-synchronized, and flower production is sparse. The FLOWERING LOCUS T (FT) gene is pivotal for floral induction in all examined angiosperms. The objective of the current work was to determine the potential roles of the FT signaling system in cassava. The Arabidopsis thaliana FT gene (atFT) was transformed into the cassava cultivar 60444 through Agrobacterium-mediated transformation and was found to be overexpressed constitutively. FT overexpression hastened flower initiation and associated fork-type branching, indicating that cassava has the necessary signaling factors to interact with and respond to the atFT gene product. In addition, overexpression stimulated lateral branching, increased the prolificacy of flower production and extended the longevity of flower development. While FT homologs in some plant species stimulate development of vegetative storage organs, atFT inhibited storage-root development and decreased root harvest index in cassava. These findings collectively contribute to our understanding of flower development in cassava and have the potential for applications in breeding.

Overexpression of Arabidopsis FLOWERING LOCUS T (FT) gene improves floral development in cassava (Manihot esculenta, Crantz)

PubMed Central

Adeyemo, O. Sarah; Chavarriaga, Paul; Tohme, Joe; Fregene, Martin; Davis, Seth J.

2017-01-01

Cassava is a tropical storage-root crop that serves as a worldwide source of staple food for over 800 million people. Flowering is one of the most important breeding challenges in cassava because in most lines flowering is late and non-synchronized, and flower production is sparse. The FLOWERING LOCUS T (FT) gene is pivotal for floral induction in all examined angiosperms. The objective of the current work was to determine the potential roles of the FT signaling system in cassava. The Arabidopsis thaliana FT gene (atFT) was transformed into the cassava cultivar 60444 through Agrobacterium-mediated transformation and was found to be overexpressed constitutively. FT overexpression hastened flower initiation and associated fork-type branching, indicating that cassava has the necessary signaling factors to interact with and respond to the atFT gene product. In addition, overexpression stimulated lateral branching, increased the prolificacy of flower production and extended the longevity of flower development. While FT homologs in some plant species stimulate development of vegetative storage organs, atFT inhibited storage-root development and decreased root harvest index in cassava. These findings collectively contribute to our understanding of flower development in cassava and have the potential for applications in breeding. PMID:28753668

Metallothionein expression in chloroplasts enhances mercury accumulation and phytoremediation capability

PubMed Central

Ruiz, Oscar N.; Alvarez, Derry; Torres, Cesar; Roman, Laura; Daniell, Henry

2015-01-01

Summary Genetic engineering to enhance mercury phytoremediation has been accomplished by expression of the merAB genes that protects the cell by converting Hg[II] into Hg[0] which volatilizes from the cell. A drawback of this approach is that toxic Hg is released back into the environment. A better phytoremediation strategy would be to accumulate mercury inside plants for subsequent retrieval. We report here the development of a transplastomic approach to express the mouse metallothionein gene (mt1) and accumulate mercury in high concentrations within plant cells. Real-time PCR analysis showed that up to 1284 copies of the mt1 gene were found per cell when compared with 1326 copies of the 16S rrn gene, thereby attaining homoplasmy. Past studies in chloroplast transformation used qualitative Southern blots to evaluate indirectly transgene copy number, whereas we used real-time PCR for the first time to establish homoplasmy and estimate transgene copy number and transcript levels. The mt1 transcript levels were very high with 183 000 copies per ng of RNA or 41% the abundance of the 16S rrn transcripts. The transplastomic lines were resistant up to 20 μm mercury and maintained high chlorophyll content and biomass. Although the transgenic plants accumulated high concentrations of mercury in all tissues, leaves accumulated up to 106 ng, indicating active phytoremediation and translocation of mercury. Such accumulation of mercury in plant tissues facilitates proper disposal or recycling. This study reports, for the first time, the use of metallothioniens in plants for mercury phytoremediation. Chloroplast genetic engineering approach is useful to express metal-scavenging proteins for phytoremediation. PMID:21518240

Overexpressed cyclophilin B suppresses apoptosis associated with ROS and Ca2+ homeostasis after ER stress.

PubMed

Kim, Jinhwan; Choi, Tae Gyu; Ding, Yan; Kim, Yeonghwan; Ha, Kwon Soo; Lee, Kyung Ho; Kang, Insug; Ha, Joohun; Kaufman, Randal J; Lee, Jinhwa; Choe, Wonchae; Kim, Sung Soo

2008-11-01

Prolonged accumulation of misfolded proteins in the endoplasmic reticulum (ER) results in ER stress-mediated apoptosis. Cyclophilins are protein chaperones that accelerate the rate of protein folding through their peptidyl-prolyl cis-trans isomerase (PPIase) activity. In this study, we demonstrated that ER stress activates the expression of the ER-localized cyclophilin B (CypB) gene through a novel ER stress response element. Overexpression of wild-type CypB attenuated ER stress-induced cell death, whereas overexpression of an isomerase activity-defective mutant, CypB/R62A, not only increased Ca(2+) leakage from the ER and ROS generation, but also decreased mitochondrial membrane potential, resulting in cell death following exposure to ER stress-inducing agents. siRNA-mediated inhibition of CypB expression rendered cells more vulnerable to ER stress. Finally, CypB interacted with the ER stress-related chaperones, Bip and Grp94. Taken together, we concluded that CypB performs a crucial function in protecting cells against ER stress via its PPIase activity.

Metal dealing at the origin of the Chordata phylum: the metallothionein system and metal overload response in amphioxus.

PubMed

Guirola, Maria; Pérez-Rafael, Sílvia; Capdevila, Mercè; Palacios, Oscar; Atrian, Sílvia

2012-01-01

Non-vertebrate chordates, specifically amphioxus, are considered of the utmost interest for gaining insight into the evolutionary trends, i.e. differentiation and specialization, of gene/protein systems. In this work, MTs (metallothioneins), the most important metal binding proteins, are characterized for the first time in the cephalochordate subphylum at both gene and protein level, together with the main features defining the amphioxus response to cadmium and copper overload. Two MT genes (BfMT1 and BfMT2) have been identified in a contiguous region of the genome, as well as several ARE (antioxidant response element) and MRE (metal response element) located upstream the transcribed region. Their corresponding cDNAs exhibit identical sequence in the two lancelet species (B. floridae and B. lanceolatum), BfMT2 cDNA resulting from an alternative splicing event. BfMT1 is a polyvalent metal binding peptide that coordinates any of the studied metal ions (Zn, Cd or Cu) rendering complexes stable enough to last in physiological environments, which is fully concordant with the constitutive expression of its gene, and therefore, with a metal homeostasis housekeeping role. On the contrary, BfMT2 exhibits a clear ability to coordinate Cd(II) ions, while it is absolutely unable to fold into stable Cu (I) complexes, even as mixed species. This identifies it as an essential detoxification agent, which is consequently only induced in emergency situations. The cephalochordate MTs are not directly related to vertebrate MTs, neither by gene structure, protein similarity nor metal-binding behavior of the encoded peptides. The closest relative is the echinoderm MT, which confirm proposed phylogenetic relationships between these two groups. The current findings support the existence in most organisms of two types of MTs as for their metal binding preferences, devoted to different biological functions: multivalent MTs for housekeeping roles, and specialized MTs that evolve either as Cd

Metal Dealing at the Origin of the Chordata Phylum: The Metallothionein System and Metal Overload Response in Amphioxus

PubMed Central

Capdevila, Mercè; Palacios, Òscar; Atrian, Sílvia

2012-01-01

Non-vertebrate chordates, specifically amphioxus, are considered of the utmost interest for gaining insight into the evolutionary trends, i.e. differentiation and specialization, of gene/protein systems. In this work, MTs (metallothioneins), the most important metal binding proteins, are characterized for the first time in the cephalochordate subphylum at both gene and protein level, together with the main features defining the amphioxus response to cadmium and copper overload. Two MT genes (BfMT1 and BfMT2) have been identified in a contiguous region of the genome, as well as several ARE (antioxidant response element) and MRE (metal response element) located upstream the transcribed region. Their corresponding cDNAs exhibit identical sequence in the two lancelet species (B. floridae and B. lanceolatum), BfMT2 cDNA resulting from an alternative splicing event. BfMT1 is a polyvalent metal binding peptide that coordinates any of the studied metal ions (Zn, Cd or Cu) rendering complexes stable enough to last in physiological environments, which is fully concordant with the constitutive expression of its gene, and therefore, with a metal homeostasis housekeeping role. On the contrary, BfMT2 exhibits a clear ability to coordinate Cd(II) ions, while it is absolutely unable to fold into stable Cu (I) complexes, even as mixed species. This identifies it as an essential detoxification agent, which is consequently only induced in emergency situations. The cephalochordate MTs are not directly related to vertebrate MTs, neither by gene structure, protein similarity nor metal-binding behavior of the encoded peptides. The closest relative is the echinoderm MT, which confirm proposed phylogenetic relationships between these two groups. The current findings support the existence in most organisms of two types of MTs as for their metal binding preferences, devoted to different biological functions: multivalent MTs for housekeeping roles, and specialized MTs that evolve either as Cd

MDM4 overexpression contributes to synoviocyte proliferation in patients with rheumatoid arthritis

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

Xu, Nanwei; Wang, Yuji, E-mail: yujiwang@sohu.com; State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai 200433

Research highlights: {yields} Elevated MDM4 mRNA and protein levels in FLS from patients with RA and OA. {yields} Strong MDM4 staining in synovial cells of inflammatory synovium. {yields} MDM4 knockdown increased p53 and p21 levels, and inhibited the proliferation of RA FLS. {yields} MDM4 overexpression increased p53 while decreased p21 levels, and promoted the growth of RA FLS. -- Abstract: Rheumatoid arthritis (RA) is a chronic autoimmune disease with features of inflammatory cell infiltration, synovial cell invasive proliferation, and ultimately, irreversible joint destruction. It has been reported that the p53 pathway is involved in RA pathogenesis. MDM4/MDMX is a majormore » negative regulator of p53. To determine whether MDM4 contributes to RA pathogenesis, MDM4 mRNA and protein expression were assessed in fibroblast-like synoviocytes (FLS) by real-time PCR, western blotting, and in synovial tissues by immunohistochemistry. Furthermore, MDM4 was knocked down and overexpressed by lentivirus-mediated expression, and the proliferative capacity of FLS was determined by MTS assay. We found that cultured FLS from RA and osteoarthritis (OA) patients exhibited higher levels of MDM4 mRNA and protein expression than those from trauma controls. MDM4 protein was highly expressed in the synovial lining and sublining cells from both types of arthritis. Finally, MDM4 knockdown inhibited the proliferation of RA FLS by enhancing functional p53 levels while MDM4 overexpression promoted the growth of RA FLS by inhibiting p53 effects. Taken together, our results suggest that the abundant expression of MDM4 in FLS may contribute to the hyperplasia phenotype of RA synovial tissues.« less

Endothelial Nitric Oxide Synthase Overexpression Restores the Efficiency of Bone Marrow Mononuclear Cell-Based Therapy

PubMed Central

Mees, Barend; Récalde, Alice; Loinard, Céline; Tempel, Dennie; Godinho, Marcia; Vilar, José; van Haperen, Rien; Lévy, Bernard; de Crom, Rini; Silvestre, Jean-Sébastien

2011-01-01

Bone marrow-derived mononuclear cells (BMMNCs) enhance postischemic neovascularization, and their therapeutic use is currently under clinical investigation. However, cardiovascular risk factors, including diabetes mellitus and hypercholesterolemia, lead to the abrogation of BMMNCs proangiogenic potential. NO has been shown to be critical for the proangiogenic function of BMMNCs, and increased endothelial NO synthase (eNOS) activity promotes vessel growth in ischemic conditions. We therefore hypothesized that eNOS overexpression could restore both the impaired neovascularization response and decreased proangiogenic function of BMMNCs in clinically relevant models of diabetes and hypercholesterolemia. Transgenic eNOS overexpression in diabetic, atherosclerotic, and wild-type mice induced a 1.5- to 2.3-fold increase in postischemic neovascularization compared with control. eNOS overexpression in diabetic or atherosclerotic BMMNCs restored their reduced proangiogenic potential in ischemic hind limb. This effect was associated with an increase in BMMNC ability to differentiate into cells with endothelial phenotype in vitro and in vivo and an increase in BMMNCs paracrine function, including vascular endothelial growth factor A release and NO-dependent vasodilation. Moreover, although wild-type BMMNCs treatment resulted in significant progression of atherosclerotic plaque in ischemic mice, eNOS transgenic atherosclerotic BMMNCs treatment even had antiatherogenic effects. Cell-based eNOS gene therapy has both proangiogenic and antiatherogenic effects and should be further investigated for the development of efficient therapeutic neovascularization designed to treat ischemic cardiovascular disease. PMID:21224043

Data set of the protein expression profiles of Luminal A, Claudin-low and overexpressing HER2+ breast cancer cell lines by iTRAQ labelling and tandem mass spectrometry

PubMed Central

Calderón-González, Karla Grisel; Valero Rustarazo, Ma Luz; Labra-Barrios, Maria Luisa; Bazán-Méndez, César Isaac; Tavera-Tapia, Alejandra; Herrera-Aguirre, Marí;aEsther; Sánchez del Pino, Manuel M.; Gallegos-Pérez, José Luis; González-Márquez, Humberto; Hernández-Hernández, Jose Manuel; León-Ávila, Gloria; Rodríguez-Cuevas, Sergio; Guisa-Hohenstein, Fernando; Luna-Arias, Juan Pedro

2015-01-01

Breast cancer is the most common and the leading cause of mortality in women worldwide. There is a dire necessity of the identification of novel molecules useful in diagnosis and prognosis. In this work we determined the differentially expression profiles of four breast cancer cell lines compared to a control cell line. We identified 1020 polypeptides labelled with iTRAQ with more than 95% in confidence. We analysed the common proteins in all breast cancer cell lines through IPA software (IPA core and Biomarkers). In addition, we selected the specific overexpressed and subexpressed proteins of the different molecular classes of breast cancer cell lines, and classified them according to protein class and biological process. Data in this article is related to the research article “Determination of the protein expression profiles of breast cancer cell lines by Quantitative Proteomics using iTRAQ Labelling and Tandem Mass Spectrometry” (Calderón-González et al. [1] in press). PMID:26217805

Vascular lysyl oxidase over-expression alters extracellular matrix structure and induces oxidative stress.

PubMed

Varona, Saray; García-Redondo, Ana B; Martínez-González, Jose; Salaices, Mercedes; Briones, Ana M; Rodríguez, Cristina

Lysyl oxidase (LOX) participates in the assembly of collagen and elastin fibres. The impact of vascular LOX over-expression on extracellular matrix (ECM) structure and its contribution to oxidative stress has been analysed. Studies were conducted on mice over-expressing LOX (Tg), specifically in smooth muscle cells (VSMC). Gene expression was assessed by real-time PCR analysis. Sirius Red staining, H 2 O 2 production and NADPH oxidase activity were analysed in different vascular beds. The size and number of fenestra of the internal elastic lamina were determined by confocal microscopy. LOX activity was up-regulated in VSMC of transgenic mice compared with cells from control animals. At the same time, transgenic cells deposited more organised elastin fibres and their supernatants induced a stronger collagen assembly in in vitro assays. Vascular collagen cross-linking was also higher in Tg mice, which showed a decrease in the size of fenestrae and an enhanced expression of Fibulin-5. Interestingly, higher H 2 O 2 production and NADPH oxidase activity was detected in the vascular wall from transgenic mice. The H 2 O 2 scavenger catalase attenuated the stronger deposition of mature elastin fibres induced by LOX transgenesis. LOX over-expression in VSMC was associated with a change in the structure of collagen and elastin fibres. LOX could constitute a novel source of oxidative stress that might participate in elastin changes and contribute to vascular remodelling. Copyright © 2017 Sociedad Española de Arteriosclerosis. Publicado por Elsevier España, S.L.U. All rights reserved.

Behavioral, neurochemical and morphological changes induced by the overexpression of munc18-1a in brain of mice: relevance to schizophrenia

PubMed Central

Urigüen, L; Gil-Pisa, I; Munarriz-Cuezva, E; Berrocoso, E; Pascau, J; Soto-Montenegro, M L; Gutiérrez-Adán, A; Pintado, B; Madrigal, J L M; Castro, E; Sánchez-Blázquez, P; Ortega, J E; Guerrero, M J; Ferrer-Alcon, M; García-Sevilla, J A; Micó, J A; Desco, M; Leza, J C; Pazos, Á; Garzón, J; Meana, J J

2013-01-01

Overexpression of the mammalian homolog of the unc-18 gene (munc18-1) has been described in the brain of subjects with schizophrenia. Munc18-1 protein is involved in membrane fusion processes, exocytosis and neurotransmitter release. A transgenic mouse strain that overexpresses the protein isoform munc18-1a in the brain was characterized. This animal displays several schizophrenia-related behaviors, supersensitivity to hallucinogenic drugs and deficits in prepulse inhibition that reverse after antipsychotic treatment. Relevant brain areas (that is, cortex and striatum) exhibit reduced expression of dopamine D1 receptors and dopamine transporters together with enhanced amphetamine-induced in vivo dopamine release. Magnetic resonance imaging demonstrates decreased gray matter volume in the transgenic animal. In conclusion, the mouse overexpressing brain munc18-1a represents a new valid animal model that resembles functional and structural abnormalities in patients with schizophrenia. The animal could provide valuable insights into phenotypic aspects of this psychiatric disorder. PMID:23340504

Activin C Antagonizes Activin A in Vitro and Overexpression Leads to Pathologies in Vivo

PubMed Central

Gold, Elspeth; Jetly, Niti; O'Bryan, Moira K.; Meachem, Sarah; Srinivasan, Deepa; Behuria, Supreeti; Sanchez-Partida, L. Gabriel; Woodruff, Teresa; Hedwards, Shelley; Wang, Hong; McDougall, Helen; Casey, Victoria; Niranjan, Birunthi; Patella, Shane; Risbridger, Gail

2009-01-01

Activin A is a potent growth and differentiation factor whose synthesis and bioactivity are tightly regulated. Both follistatin binding and inhibin subunit heterodimerization block access to the activin receptor and/or receptor activation. We postulated that the activin-βC subunit provides another mechanism regulating activin bioactivity. To test our hypothesis, we examined the biological effects of activin C and produced mice that overexpress activin-βC. Activin C reduced activin A bioactivity in vitro; in LNCaP cells, activin C abrogated both activin A-induced Smad signaling and growth inhibition, and in LβT2 cells, activin C antagonized activin A-mediated activity of an follicle-stimulating hormone-β promoter. Transgenic mice that overexpress activin-βC exhibited disease in testis, liver, and prostate. Male infertility was caused by both reduced sperm production and impaired sperm motility. The livers of the transgenic mice were enlarged because of an imbalance between hepatocyte proliferation and apoptosis. Transgenic prostates showed evidence of hypertrophy and epithelial cell hyperplasia. Additionally, there was decreased evidence of nuclear Smad-2 localization in the testis, liver, and prostate, indicating that overexpression of activin-βC antagonized Smad signaling in vivo. Underlying the significance of these findings, human testis, liver, and prostate cancers expressed increased activin-βC immunoreactivity. This study provides evidence that activin-βC is an antagonist of activin A and supplies an impetus to examine its role in development and disease. PMID:19095948

Zinc rescues obesity-induced cardiac hypertrophy via stimulating metallothionein to suppress oxidative stress-activated BCL10/CARD9/p38 MAPK pathway.

PubMed

Wang, Shudong; Gu, Junlian; Xu, Zheng; Zhang, Zhiguo; Bai, Tao; Xu, Jianxiang; Cai, Jun; Barnes, Gregory; Liu, Qiu-Ju; Freedman, Jonathan H; Wang, Yonggang; Liu, Quan; Zheng, Yang; Cai, Lu

2017-06-01

Obesity often leads to obesity-related cardiac hypertrophy (ORCH), which is suppressed by zinc-induced inactivation of p38 mitogen-activated protein kinase (p38 MAPK). In this study, we investigated the mechanisms by which zinc inactivates p38 MAPK to prevent ORCH. Mice (4-week old) were fed either high fat diet (HFD, 60% kcal fat) or normal diet (ND, 10% kcal fat) containing variable amounts of zinc (deficiency, normal and supplement) for 3 and 6 months. P38 MAPK siRNA and the p38 MAPK inhibitor SB203580 were used to suppress p38 MAPK activity in vitro and in vivo, respectively. HFD activated p38 MAPK and increased expression of B-cell lymphoma/CLL 10 (BCL10) and caspase recruitment domain family member 9 (CARD9). These responses were enhanced by zinc deficiency and attenuated by zinc supplement. Administration of SB203580 to HFD mice or specific siRNA in palmitate-treated cardiomyocytes eliminated the HFD and zinc deficiency activation of p38 MAPK, but did not significantly impact the expression of BCL10 and CARD9. In cultured cardiomyocytes, inhibition of BCL10 expression by siRNA prevented palmitate-induced increased p38 MAPK activation and atrial natriuretic peptide (ANP) expression. In contrast, inhibition of p38 MAPK prevented ANP expression, but did not affect BCL10 expression. Deletion of metallothionein abolished the protective effect of zinc on palmitate-induced up-regulation of BCL10 and phospho-p38 MAPK. HFD and zinc deficiency synergistically induce ORCH by increasing oxidative stress-mediated activation of BCL10/CARD9/p38 MAPK signalling. Zinc supplement ameliorates ORCH through activation of metallothionein to repress oxidative stress-activated BCL10 expression and p38 MAPK activation. © 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

The role of metallothioneins, selenium and transfer to offspring in mercury detoxification in Franciscana dolphins (Pontoporia blainvillei).

PubMed

Romero, M B; Polizzi, P; Chiodi, L; Das, K; Gerpe, M

2016-08-15

The concentrations of mercury (Hg), selenium (Se) and metallothioneins (MT) were evaluated in fetuses, calves, juveniles and adults of the endangered coastal Franciscana dolphin (Pontoporia blainvillei) from Argentina. Mercury concentrations varied among analyzed tissues (liver, kidney, muscle and brain), with liver showing the higher concentrations in all specimens. An age-dependent accumulation was found in liver, kidney and brain. No significant relationship between Hg and MT concentrations was found for all tissues analyzed. Hepatic Hg molar concentrations were positively correlated with those of Se, indicating a great affinity between these two elements. Furthermore, dark granules of HgSe were observed in Kupffer cells in the liver by electron microscopy, suggesting the role of this macrophage in the detoxification of Hg. A transfer of Hg through placenta was proved. The presence of Hg in brain in all age classes did not show concentrations associated with neurotoxicity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Electrophysiology and metabolism of caveolin-3 overexpressing mice

PubMed Central

Schilling, Jan M.; Horikawa, Yousuke T.; Zemljic-Harpf, Alice E.; Vincent, Kevin P.; Tyan, Leonid; Yu, Judith K.; McCulloch, Andrew D.; Balijepalli, Ravi C.; Patel, Hemal H.; Roth, David M.

2017-01-01

Caveolin-3 (Cav-3) plays a critical role in organizing signaling molecules and ion channels involved in cardiac conduction and metabolism. Mutations in Cav-3 are implicated in cardiac conduction abnormalities and myopathies. Additionally, cardiac specific overexpression of Cav-3 (Cav-3 OE) is protective against ischemic and hypertensive injury suggesting a potential role for Cav-3 in basal cardiac electrophysiology and metabolism involved in stress adaptation. We hypothesized that overexpression of Cav-3 may alter baseline cardiac conduction and metabolism. We examined: 1) ECG telemetry recordings at baseline and during pharmacological interventions, 2) ion channels involved in cardiac conduction with immunoblotting and computational modeling, and 3) baseline metabolism in Cav-3 OE and transgene negative littermate control mice. Cav-3 OE mice had decreased heart rates, prolonged PR intervals, and shortened QTc intervals with no difference in activity compared to control mice. Dobutamine or propranolol did not cause significant changes between experimental groups in maximal (dobutamine) or minimal (propranolol) heart rate. Cav-3 OE mice had an overall lower chronotropic response to atropine. Expression of Kv1.4 and Kv4.3 channels, Nav1.5 channels and connexin 43 were increased in Cav-3 OE mice. A computational model integrating the immunoblotting results indicated shortened action potential duration in Cav-3 OE mice linking the change in channel expression to the observed electrophysiology phenotype. Metabolic profiling showed no gross differences in VO2, VCO2, respiratory exchange ratio, and heat generation, feeding or drinking. In conclusion, Cav-3 OE mice have changes in ECG intervals, heart rates, and cardiac ion channel expression. These findings give novel mechanistic insights into previously reported Cav-3 dependent cardioprotection. PMID:27023865

c-Ski overexpression promotes tumor growth and angiogenesis through inhibition of transforming growth factor-beta signaling in diffuse-type gastric carcinoma.

PubMed

Kiyono, Kunihiko; Suzuki, Hiroshi I; Morishita, Yasuyuki; Komuro, Akiyoshi; Iwata, Caname; Yashiro, Masakazu; Hirakawa, Kosei; Kano, Mitsunobu R; Miyazono, Kohei

2009-10-01

c-Ski, originally identified as a proto-oncogene product, is an important negative regulator of transforming growth factor (TGF)-beta family signaling through interaction with Smad2, Smad3, and Smad4. High expression of c-Ski has been found in some cancers, including gastric cancer. We previously showed that disruption of TGF-beta signaling by dominant-negative TGF-beta type II receptor in a diffuse-type gastric carcinoma model accelerated tumor growth through induction of tumor angiogenesis by decreased expression of the anti-angiogenic factor thrombospondin (TSP)-1. Here, we examined the function of c-Ski in human diffuse-type gastric carcinoma OCUM-2MLN cells. Overexpression of c-Ski inhibited TGF-beta signaling in OCUM-2MLN cells. Interestingly, c-Ski overexpression resulted in extensive acceleration of the growth of subcutaneous xenografts in BALB/c nu/nu female mice (6 weeks of age). Similar to tumors expressing dominant-negative TGF-beta type II receptor, histochemical studies revealed less fibrosis and increased angiogenesis in xenografted tumors expressing c-Ski compared to control tumors. Induction of TSP-1 mRNA by TGF-beta was attenuated by c-Ski in vitro, and expression of TSP-1 mRNA was decreased in tumors expressing c-Ski in vivo. These findings suggest that c-Ski overexpression promotes the growth of diffuse-type gastric carcinoma through induction of angiogenesis.

Overexpression of phosphoserine aminotransferase PSAT1 stimulates cell growth and increases chemoresistance of colon cancer cells

PubMed Central

Vié, Nadia; Copois, Virginie; Bascoul-Mollevi, Caroline; Denis, Vincent; Bec, Nicole; Robert, Bruno; Fraslon, Caroline; Conseiller, Emmanuel; Molina, Franck; Larroque, Christian; Martineau, Pierre; Del Rio, Maguy; Gongora, Céline

2008-01-01

Background Colorectal cancer (CRC) is one of the most common causes of cancer death throughout the world. In this work our aim was to study the role of the phosphoserine aminotransferase PSAT1 in colorectal cancer development. Results We first observed that PSAT1 is overexpressed in colon tumors. In addition, we showed that after drug treatment, PSAT1 expression level in hepatic metastases increased in non responder and decreased in responder patients. In experiments using human cell lines, we showed that ectopic PSAT1 overexpression in colon carcinoma SW480 cell line resulted in an increase in its growth rate and survival. In addition, SW480-PSAT1 cells presented a higher tumorigenic potential than SW480 control cells in xenografted mice. Moreover, the SW480-PSAT1 cell line was more resistant to oxaliplatin treatment than the non-transfected SW480 cell line. This resistance resulted from a decrease in the apoptotic response and in the mitotic catastrophes induced by the drug treatment. Conclusion These results show that an enzyme playing a role in the L-serine biosynthesis could be implicated in colon cancer progression and chemoresistance and indicate that PSAT1 represents a new interesting target for CRC therapy. PMID:18221502

Overexpression of FurA in Anabaena sp. PCC 7120 reveals new targets for this regulator involved in photosynthesis, iron uptake and cellular morphology.

PubMed

González, Andrés; Bes, M Teresa; Barja, François; Peleato, M Luisa; Fillat, María F

2010-11-01

Previous genomic analyses of the filamentous nitrogen-fixing cyanobacterium Anabaena sp. PCC 7120 have identified three ferric uptake regulator (Fur) homologs with low sequence identities and probably different functions in the cell. FurA is a constitutive protein that shares the highest homology with Fur from heterotrophic bacteria and appears to be essential for in vitro growth. In this study, we have analysed the effects of FurA overexpression on the Anabaena sp. phenotype and investigated which of the observed alterations were directly operated by FurA. Overexpression of the regulator led to changes in cellular morphology, resulting in shorter filaments with rounded cells of different sizes. The furA-overexpressing strain showed a slower photoautotrophic growth and a marked decrease in the oxygen evolution rate. Overexpression of the regulator also decreased both catalase and superoxide dismutase activities, but did not lead to an increase in the levels of intracellular reactive oxygen species. By combining phenotypic studies, reverse transcription-PCR analyses and electrophoretic mobility shift assays, we identified three novel direct targets of FurA, including genes encoding a siderophore outer membrane transporter (schT), bacterial actins (mreBCD) and the PSII reaction center protein D1 (psbA). The affinity of FurA for these novel targets was markedly affected by the absence of divalent metal ions, confirming previous evidence of a critical role for the metal co-repressor in the function of the regulator in vivo. The results unravel new cellular processes modulated by FurA, supporting its role as a global transcriptional regulator in Anabaena sp. PCC 7120.

Overexpression of erg1 gene in Trichoderma harzianum CECT 2413: effect on the induction of tomato defence-related genes.

PubMed

Cardoza, R E; Malmierca, M G; Gutiérrez, S

2014-09-01

To investigate the effect of the overexpression of erg1 gene of Trichoderma harzianum CECT 2413 (T34) on the Trichoderma-plant interactions and in the biocontrol ability of this fungus. Transformants of T34 strain overexpressing erg1 gene did not show effect on the ergosterol level, although a drastic decrease in the squalene level was observed in the transformants at 96 h of growth. During interaction with plants, the erg1 overexpression resulted in a reduction of the priming ability of several tomato defence-related genes belonging to the salicylate pathway, and also of the TomLoxA gene, which is related to the jasmonate pathway. Interestingly, other jasmonate-related genes, such as PINI and PINII, were slightly induced. The erg1 overexpressed transformants also showed a reduced ability to colonize tomato roots. The ergosterol biosynthetic pathway might play an important role in regulating Trichoderma-plant interactions, although this role does not seem to be restricted to the final product; instead, other intermediates such as squalene, whose role in the Trichoderma-plant interaction has not been characterized, would also play an important role. The functional analysis of genes involved in the synthesis of ergosterol could provide additional strategies to improve the ability of biocontrol of the Trichoderma strains and their interaction with plants. © 2014 The Society for Applied Microbiology.

A novel strategy to improve protein secretion via overexpression of the SppA signal peptide peptidase in Bacillus licheniformis.

PubMed

Cai, Dongbo; Wang, Hao; He, Penghui; Zhu, Chengjun; Wang, Qin; Wei, Xuetuan; Nomura, Christopher T; Chen, Shouwen

2017-04-24

Signal peptide peptidases play an important role in the removal of remnant signal peptides in the cell membrane, a critical step for extracellular protein production. Although these proteins are likely a central component for extracellular protein production, there has been a lack of research on whether protein secretion could be enhanced via overexpression of signal peptide peptidases. In this study, both nattokinase and α-amylase were employed as prototypical secreted target proteins to evaluate the function of putative signal peptide peptidases (SppA and TepA) in Bacillus licheniformis. We observed dramatic decreases in the concentrations of both target proteins (45 and 49%, respectively) in a sppA deficient strain, while the extracellular protein yields of nattokinase and α-amylase were increased by 30 and 67% respectively in a strain overexpressing SppA. In addition, biomass, specific enzyme activities and the relative gene transcriptional levels were also enhanced due to the overexpression of sppA, while altering the expression levels of tepA had no effect on the concentrations of the secreted target proteins. Our results confirm that SppA, but not TepA, plays an important functional role for protein secretion in B. licheniformis. Our results indicate that the sppA overexpression strain, B. licheniformis BL10GS, could be used as a promising host strain for the industrial production of heterologous secreted proteins.

Process development for a recombinant Chinese hamster ovary (CHO) cell line utilizing a metal induced and amplified metallothionein expression system.

PubMed

Huang, Edwin P; Marquis, Christopher P; Gray, Peter P

2004-11-20

The suspension Chinese Hamster Ovary cell line, 13-10-302, utilizing the metallothionein (MT) expression system producing recombinant human growth hormone (hGH) was studied in a serum-free and cadmium-free medium at different fermentation scales and modes of operation. Initial experiments were carried out to optimize the concentration of metal addition to induce the MT promoter. Subsequently, the cultivation of the 13-10-302 cell line was scaled up from spinner flasks into bioreactors, and the cultivation duration was extended with fed-batch and perfusion strategies utilizing 180 microM zinc to induce the promoter controlling expression of recombinant hGH. It was shown that a fed-batch process could increase the maximum cell numbers twofold, from 3.3 to 6.3 x 10(6) cell/mL, over those obtained in normal batch fermentations, and this coupled with extended fermentation times resulted in a fourfold increase in final hGH titer, from 135 +/- 15 to 670 +/- 70 mg/L at a specific productivity q(hGH) value of 12 pg cell(-1)d(-1). The addition of sodium butyrate increased the specific productivity of hGH in cells to a value of approximately 48 pg cell(-1)d(-1), resulting in a final hGH titer of over a gram per liter during fed-batch runs. A BioSep acoustic cell recycler was used to retain the cells in the bioreactor during perfusion operation. It was necessary to maintain the specific feeding rates (SFR) above a value of 0.2 vvd/(10(6) cell/mL) to maintain the viability and productivity of the 13-10-302 cells; under these conditions the viable cell number increased to over 10(7) cell/mL and resulted in a volumetric productivity of over 120 mg(hGH) L(-1)d(-1). Process development described in this work demonstrates cultivation at various scales and sustained high levels of productivity under cadmium free condition in a CHO cell line utilizing an inducible metallothionein expression system. (c) 2004 Wiley Periodicals, Inc

Role of ARF6 in internalization of metal-binding proteins, metallothionein and transferrin, and cadmium-metallothionein toxicity in kidney proximal tubule cells

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

Wolff, Natascha A.; Lee, Wing-Kee; Abouhamed, Marouan

2008-07-01

Filtered metal-protein complexes, such as cadmium-metallothionein-1 (CdMT-1) or transferrin (Tf) are apically endocytosed partly via megalin/cubilin by kidney proximal tubule (PT) cells where CdMT-1 internalization causes apoptosis. Small GTPase ARF (ADP-ribosylation factor) proteins regulate endocytosis and vesicular trafficking. We investigated roles of ARF6, which has been shown to be involved in internalization of ligands and endocytic trafficking in PT cells, following MT-1/CdMT-1 and Tf uptake by PT cells. WKPT-0293 Cl.2 cells derived from rat PT S1 segment were transfected with hemagglutinin-tagged wild-type (ARF6-WT) or dominant negative (ARF6-T27N) forms of ARF6. Using immunofluorescence, endogenous ARF6 was associated with the plasma membranemore » (PM) as well as juxtanuclear and co-localized with Rab5a and Rab11 involved in early and recycling endosomal trafficking. Immunofluorescence staining of megalin showed reduced surface labelling in ARF6 dominant negative (ARF6-DN) cells. Intracellular Alexa Fluor 546-conjugated MT-1 uptake was reduced in ARF6-DN cells and CdMT-1 (14.8 {mu}M for 24 h) toxicity was significantly attenuated from 27.3 {+-} 3.9% in ARF6-WT to 11.1 {+-} 4.0% in ARF6-DN cells (n = 6, P < 0.02). Moreover, reduced Alexa Fluor 546-conjugated Tf uptake was observed in ARF-DN cells (75.0 {+-} 4.6% versus 3.9 {+-} 3.9% of ARF6-WT cells, n = 3, P < 0.01) and/or remained near the PM (89.3 {+-} 5. 6% versus 45.2 {+-} 14.3% of ARF6-WT cells, n = 3, P < 0.05). In conclusion, the data support roles for ARF6 in receptor-mediated endocytosis and trafficking of MT-1/Tf to endosomes/lysosomes and CdMT-1 toxicity of PT cells.« less

Overexpression of SIRT1 Protects Pancreatic β-Cells Against Cytokine Toxicity by Suppressing the Nuclear Factor-κB Signaling Pathway