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Sample records for induced differential effect

  1. [Effect of mitogen-activated protein kinases on ATRA-induced differentiation of NB4 cells].

    PubMed

    Wang, Su; Liu, Yun-Peng; Hou, Ke-Zuo; Wang, Yan; Luo, Ying

    2008-12-01

    The aim of this study was to observe the effect of p38MAPK inhibitor SB203580 on ATRA-induced differentiation of NB4 cells. The proliferation activity of cells was assayed by MTT method, the cell cycle was detected by flow cytometry, the differentiation of NB4 cells into granulocytes was measured by test of NBT reduction, the activity of extracellular signal-regulated kinase (ERK) was detected by substrate phosphorylation. The results showed that the ATRA in 0.01-01 micromol/L inhibited the proliferation of NB4 cells in time-and dose-dependent manner and induced the differentiation of NB4 cells into myeloid; the ATRA stimulated ERK activity in this process; ERK inhibitor PD98059 could partially block ATRA effect, specific inhibitor of p38MAPK, SB203580, combined with ATRA also could partially block the effects of ATRA on inhibition of NB4 growth and induction of differentiation. It is concluded that the ATRA stimulates ERK and p38MAPK pathway in the process inducing differentiation of NB4 cells, the ERK and P38MAPK may be necessary for the ATRA-induced differentiation in NB4 cells.

  2. Differential effects of pannexins on noise-induced hearing loss.

    PubMed

    Abitbol, Julia M; Kelly, John J; Barr, Kevin; Schormans, Ashley L; Laird, Dale W; Allman, Brian L

    2016-12-15

    Hearing loss, including noise-induced hearing loss, is highly prevalent and severely hinders an individual's quality of life, yet many of the mechanisms that cause hearing loss are unknown. The pannexin (Panx) channel proteins, Panx1 and Panx3, are regionally expressed in many cell types along the auditory pathway, and mice lacking Panx1 in specific cells of the inner ear exhibit hearing loss, suggesting a vital role for Panxs in hearing. We proposed that Panx1 and/or Panx3 null mice would exhibit severe hearing loss and increased susceptibility to noise-induced hearing loss. Using the auditory brainstem response, we surprisingly found that Panx1(-/-) and Panx3(-/-) mice did not harbor hearing or cochlear nerve deficits. Furthermore, while Panx1(-/-) mice displayed no protection against loud noise-induced hearing loss, Panx3(-/-) mice exhibited enhanced 16- and 24-kHz hearing recovery 7 days after a loud noise exposure (NE; 12 kHz tone, 115 dB sound pressure level, 1 h). Interestingly, Cx26, Cx30, Cx43, and Panx2 were up-regulated in Panx3(-/-) mice compared with wild-type and/or Panx1(-/-) mice, and assessment of the auditory tract revealed morphological changes in the middle ear bones of Panx3(-/-) mice. It is unclear if these changes alone are sufficient to provide protection against loud noise-induced hearing loss. Contrary to what we expected, these data suggest that Panx1 and Panx3 are not essential for baseline hearing in mice tested, but the therapeutic targeting of Panx3 may prove protective against mid-high-frequency hearing loss caused by loud NE.

  3. Effects of extremely low frequency magnetic fields on NGF induced neuronal differentiation of PC12 cells.

    PubMed

    Jung, In-Soo; Kim, Hyun-Jung; Noh, Ran; Kim, Soo-Chan; Kim, Chan-Wha

    2014-10-01

    Extremely low-frequency magnetic fields (ELF-MFs) affect various cellular processes and systems, such as cell proliferation, differentiation and metabolic pathways. The present study investigated ELF-MFs effect on nerve growth factor (NGF) induced neuronal differentiation of PC12 cells using proteomic applications to understand its role in the enhancement of neuronal differentiation. After 50 Hz, 1 mT ELF-MFs 5-day exposure on NGF induced PC12 cells, it was observed to increase neurite length as well as an increase in the number of neurite bearing cells. It was also discovered that there was a decrease in proliferation activity, which is associated with an increase in differentiated cells. Neuronal differentiation related mRNA levels and protein levels were increased in NGF induced PC12 cells. Compared with NGF induced group, ELF-MFs stimulated PC12 cells had different protein expression as measured with two-dimensional electrophoresis (2-DE) gels. Consequently six differentially expressed spots were detected between the 2-DE maps, which were identified by electrospray ionization quadrupole time-of-flight tandem mass spectrometry (ESI-Q-TOF LC/MS/MS) as: peripherin, neurosecretory protein nerve growth factor inducible (VGF8a) precursor, dnaK-type molecular chaperone sp72-ps1 (HSP72-psI), low molecular weight (Mr) phosphotyrosine protein phosphatase isoenzyme AcP1 (LMW-PTP/ACP1), Tubulin alpha-1A (TUBA1A) chain, outcome predictor in acute leukemia 1 homolog (OPA1L). The identification of these proteins provides clues to the mechanism of ELF-MFs stimulation on NGF induced PC12 cells that occur during neuronal differentiation and may contribute to the development novel treatments for neurodegenerative diseases.

  4. Identification of Centella asiatica's Effective Ingredients for Inducing the Neuronal Differentiation

    PubMed Central

    Jiang, Hui; Zheng, Guoshuai; Lv, Junwei; Chen, Heyu; Lin, Jinjin; Li, Yiyang; Fan, Guorong

    2016-01-01

    Centella asiatica, commonly known as Gotu kola, has been widely used as a traditional herb for decades. Yet, the study on which compounds or compound combinations actually lead to its brain benefits remains scarce. To study the neuroprotection effects of Centella asiatica, neuronal differentiation of PC12 cells was applied. In our pilot study, we isolated 45 Centella asiatica fractions and tested their abilities for inducing neuronal differentiation on PC12 cells. The most effective fraction showed robust induction in neurite outgrowth and neurofilament expression. LC-MS fingerprint analysis of this fraction revealed asiatic acid and madecassic acid as the dominant components. A further investigation on the pure combination of these two compounds indicated that the combination of these two compounds extensively promoted nerve differentiation in vitro. Application of PD98059, a protein MEK inhibitor, attenuated combination-induced neurofilament expression, indicating the combination-induced nerve differentiation through activation of MEK signaling pathway. Our results support the use of combination of asiatic acid and madecassic acid as an effective mean to intervene neurodegenerative diseases in which neurotrophin deficiency is involved. PMID:27446228

  5. Murine bone cell lines as models for spaceflight induced effects on differentiation and gene expression

    NASA Astrophysics Data System (ADS)

    Lau, P.; Hellweg, C. E.; Baumstark-Khan, C.; Reitz, G.

    Critical health factors for space crews especially on long-term missions are radiation exposure and the absence of gravity DNA double strand breaks DSB are presumed to be the most deleterious DNA lesions after radiation as they disrupt both DNA strands in close proximity Besides radiation risk the absence of gravity influences the complex skeletal apparatus concerning muscle and especially bone remodelling which results from mechanical forces exerting on the body Bone is a dynamic tissue which is life-long remodelled by cells from the osteoblast and osteoclast lineage Any imbalance of this system leads to pathological conditions such as osteoporosis or osteopetrosis Osteoblastic cells play a crucial role in bone matrix synthesis and differentiate either into bone-lining cells or into osteocytes Premature terminal differentiation has been reported to be induced by a number of DNA damaging or cell stress inducing agents including ionising and ultraviolet radiation as well as treatment with mitomycin C In the present study we compare the effects of sequential differentiation by adding osteoinductive substances ss -glycerophosphate and ascorbic acid Radiation-induced premature differentiation was investigated regarding the biosynthesis of specific osteogenic marker molecules and the differentiation dependent expression of marker genes The bone cell model established in our laboratory consists of the osteocyte cell line MLO-Y4 the osteoblast cell line OCT-1 and the subclones 4 and 24 of the osteoblast cell line MC3T3-E1 expressing several

  6. Effect of amorphous silica nanoparticles on in vitro RANKL-induced osteoclast differentiation in murine macrophages

    PubMed Central

    2011-01-01

    Amorphous silica nanoparticles (nSP) have been used as a polishing agent and/or as a remineralization promoter for teeth in the oral care field. The present study investigates the effects of nSP on osteoclast differentiation and the relationship between particle size and these effects. Our results revealed that nSP exerted higher cytotoxicity in macrophage cells compared with submicron-sized silica particles. However, tartrate-resistant acid phosphatase (TRAP) activity and the number of osteoclast cells (TRAP-positive multinucleated cells) were not changed by nSP treatment in the presence of receptor activator of nuclear factor κB ligand (RANKL) at doses that did not induce cytotoxicity by silica particles. These results indicated that nSP did not cause differentiation of osteoclasts. Collectively, the results suggested that nanosilica exerts no effect on RANKL-induced osteoclast differentiation of RAW264.7 cells, although a detailed mechanistic examination of the nSP70-mediated cytotoxic effect is needed. PMID:21777482

  7. Effect of siRNA PERK on fluoride-induced osteoblastic differentiation in OS732 cells.

    PubMed

    Lü, Peng; Li, Xining; Ruan, Lihong; Xu, Hui; Liu, Qinyi

    2014-06-01

    The purpose of this work is to study the action of fluoride on osteoblastic function through knocking down double-stranded RNA-activated protein kinase (PKR)-like ER kinase (PERK) mRNA in OS732 cells (human osteoblast-like cell line). The previous researches had demonstrated that fluoride induced endoplasmic reticulum (ER) stresses in other cells or tissues. PERK as one branch of UPR to combat ER stress played a role in mediating the proliferation and differentiation of osteoblast. The mechanism of skeletal fluorosis by which fluoride regulated osteoblast was not fully defined. We used the real-time PCR and small interfering RNA techniques to determine the expression PERK signaling and osteoblastic and osteoclastic differentiation-related factors and investigated the role of PERK signaling in fluoride-stimulated osteoblastic function. Cells transfected with 50 nM small interfering RNA (siRNA)-PERK showed effectively decreased protein and gene expression of PERK and reduced protein expression of nuclear factor erythroid 2-related factor 2 (Nrf2). Meantime, cells transfected with siRNA significantly decreased the protein level of alkaline phosphatase (ALP) and nuclear factor kappa B ligand (RANKL) in cells under fluoride exposure. It suggested that knockdown of PERK expression hardly stimulated osteoblastic and osteoclastic early differentiation induced by fluoride. Conversely, there were littler effect of siRNA PERK on expression of Runt-related transcription factor 2 (RUNX2) and osteoprotegerin (OPG) in cells, but fluoride exposure markedly stimulated their expression. This study proved that the mechanism underlying fluoride induced osteoblastic and osteoclastic differentiation possible was due to activation of ALP and RANKL mediated by PERK in OS732 cells.

  8. Dose-dependent effects of differential rearing on amphetamine-induced hyperactivity.

    PubMed

    Cain, Mary E; Mersmann, Marian G; Gill, Margaret J; Pittenger, Steven T

    2012-12-01

    Differential rearing decreases psychostimulant-induced hyperactivity. In general, environmental enrichment decreases the locomotor response to low unit doses of psychostimuluants, whereas isolation increases the response. It is not clear whether the changes in locomotor activity are due to an enrichment-induced decrease or an isolation-induced increase. Therefore, the current experiments examined the ability of enrichment rearing, as compared with isolation and standard rearing, to attenuate amphetamine-induced hyperactivity following acute administration, repeated administration, and sensitization of a low (0.3 mg/kg) and moderate (1.0 mg/kg) dose of amphetamine. Rats were reared under enriched, isolated, or standard conditions. Enrichment slowed the acquisition of amphetamine-induced hyperactivity and attenuated the expression of amphetamine-induced sensitization, but only at the low unit dose. Enrichment did not protect against the expression of conditioned hyperactivity at either of the doses tested. The behavior of standard condition rats was generally closer to that of isolated condition rats than enriched condition rats, suggesting that the enrichment attenuates the response to amphetamine as opposed to isolation rearing increasing the response to amphetamine. These results suggest that the effects of enrichment are because of enrichment manipulation and not simply a contrast from the effects of isolation.

  9. The inhibitory effect of vitamin K on RANKL-induced osteoclast differentiation and bone resorption.

    PubMed

    Wu, Wei-Jie; Kim, Min Seuk; Ahn, Byung-Yong

    2015-10-01

    To further understand the correlation between vitamin K and bone metabolism, the effects of vitamins K1, menaquinone-4 (MK-4), and menaquinone-7 (MK-7) on RANKL-induced osteoclast differentiation and bone resorption were comparatively investigated. Vitamin K2 groups (MK-4 and MK-7) were found to significantly inhibit RANKL-medicated osteoclast cell formation of bone marrow macrophages (BMMs) in a dose-dependent manner, without any evidence of cytotoxicity. The mRNA expression of specific osteoclast differentiation markers, such as c-Fos, NFATc1, OSCAR, and TRAP, as well as NFATc1 protein expression and TRAP activity in RANKL-treated BMMs were inhibited by vitamin K2, although MK-4 exhibited a significantly greater efficiency compared to MK-7. In contrast, the same dose of vitamin K1 had no inhibitory effect on RANKL-induced osteoclast cell formation, but increased the expression of major osteoclastogenic genes. Interestingly, vitamins K1, MK-4 and MK-7 all strongly inhibited osteoclastic bone resorption (p < 0.01) in a dose dependent manner. These results suggest that vitamins K1, MK-4 and MK-7 have anti-osteoporotic properties, while their regulation effects on osteoclastogenesis are somewhat different.

  10. Effect of Lycium bararum polysaccharides on methylmercury-induced abnormal differentiation of hippocampal stem cells

    PubMed Central

    Tian, Jian-Ying; Chen, Wei-Wei; Cui, Jing; Wang, Hao; Chao, Ci; Lu, Zhi-Yan; Bi, Yong-Yi

    2016-01-01

    The aim of the present study was to observe the effects of a general extract of Lycium bararum polysaccharides (LBPs) on methylmercury (MeHg)-induced damage in hippocampus neural stem cells (hNSCs). The hippocampal tissues of embryonic day 16 Sprague-Dawley rats were extracted for the isolation, purification and cloning of hNSCs. Following passage and proliferation for 10 days, the cells were allocated at random into the following groups: Control, LBPs, MeHg and MeHg + LBPs. MTT and microtubule-associated protein 2 (MAP-2)/glial fibrillary acidic protein/Hoechst immunofluorescence tests were performed to detect the differentiation and growth of hNSCs in the various groups. The differentiation rate of MeHg-treated hNSCs and the perimeter of MAP-2-positive neurons were 3.632±0.63% and 62.36±5.58 µm, respectively, significantly lower compared with the control group values of 6.500±0.81% and 166±8.16 µm (P<0.05). Furthermore, the differentiation rate and the perimeter of MAP-2-positive neurons in LBPs groups cells was 7.75±0.59% and 253.3±11.21 µm, respectively, significantly higher compared with the control group (P<0.05). The same parameters in the MeHg + LBPs group were 5.92±0.98% and 111.9±6.07 µm, respectively, significantly higher than the MeHg group (P<0.05). The astrocyte differentiation rates in the MeHg and MeHg + LBPs group were 41.19±2.14 and 34.58±1.70, respectively (P<0.05). These results suggest that LBPs may promote the generation and development of new neurons and inhibit the MeHg-induced abnormal differentiation of astrocytes. Thus, LBPs may be considered to be a potential new treatment for MeHg-induced neurotoxicity in hNSCs. PMID:27446261

  11. Effects of Melatonin on Differentiation Potential of Ito Cells in Mice with Induced Fibrosis of the Liver.

    PubMed

    Nalobin, D S; Suprunenko, E A; Golichenkov, V A

    2016-10-01

    We studied the effects of melatonin on differentiation potential of Ito cells during atypical regeneration of mouse liver under conditions of CCl4-induced fibrosis. The dynamics of fibrosis was traced at the histological level and the effects of melatonin on the differentiation potential of mouse Ito cells were evaluated. Melatonin alleviated fibrotic changes in the liver tissue and reduced differentiation of Ito cells into myofibroblasts under conditions of atypical regeneration of the liver in induced fibrosis. The hepatoprotective role of melatonin was shown.

  12. Effects of nano tantalum implants on inducing osteoblast proliferation and differentiation

    PubMed Central

    Liu, Xinyu; Song, Xiaobin; Zhang, Peng; Zhu, Zhenkun; Xu, Xin

    2016-01-01

    In the present study, we examined the effects of nano tantalum (Ta) dental implants on inducing osteoblast proliferation and differentiation. The MG-63 osteoblasts were divided into 3 groups after recovery, passage and storage: i) Osteoblast culturing group (control group); ii) osteoblast and titanium (Ti) implant co-culturing group (Ti group); and iii) osteoblast and Ta implant co-culturing group (Ta group). After 7 days, a scanning electron microscope was used to observe the growth status, number and morphological changes of the cells on the surfaces of the materials. An MTT assay was used to detect cell proliferation after culturing for 1, 3 and 7 days. ELISA assay was used to detect the levels of alkaline phosphatase (ALP) after 1, 3 and 7 days. Western blot analysis was used to detect the expression levels of collagen type I (Col-1) and osteocalcin after 1, 3 and 7 days. There was significant cell spreading on the surfaces of Ti and of Ta after 7 days, flat and with many pseudopodia. Additionally, there were more cell components in the Ta group. Concurrently, cell proliferation in the Ti and Ta groups increased. There was also an increase in the level of ALP and the expression level of Col-1 over time. The indexes of the Ta group were more apparent than those of the Ti group at each time-point, and the differences were statistically significant (p<0.05). In conclusion, compared with Ti implants, Ta implants induced more osteoblast proliferation and differentiation. PMID:28101149

  13. Differential Genetic Effects on Statin-Induced Changes Across Low-Density Lipoproprotein Related Measures

    PubMed Central

    Chu, Audrey Y.; Giulianini, Franco; Barratt, Bryan J.; Ding, Bo; Nyberg, Fredrik; Mora, Samia; Ridker, Paul M.; Chasman, Daniel I.

    2015-01-01

    Background Statin therapy influences not only low-density lipoprotein-cholesterol (LDL-C) levels, but also LDL-related biomarkers including non-high-density lipoprotein cholesterol (non-HDL-C), apolipoprotein B (apo B), total number of LDL particles (LDL-P), and mean LDL particle size (LDL-size). Recent studies have identified many genetic loci influencing circulating lipid levels and statin-induced LDL-C reduction. However, it is unknown how these genetic variants influence statin-induced change in LDL subfractions and non-HDL-C. Methods and Results One hundred and sixty candidate SNPs for effects on circulating lipid levels or statin-induced LDL-C lowering were tested for association with response of LDL subfractions and non-HDL-C to rosuvastatin or placebo over 1 year among 7,046 participants from the JUPITER trial. Of the 51 SNPs associated with statin response for one or more of the LDL subfractions, or non-HDL-C, 20 SNPs could be clustered according to effects predominantly on LDL-size, predominantly on LDL particle number, and on apo B but not LDL-C or non-HDL-C. Conclusions These differential associations point to pathways of LDL response to statin therapy and possibly to mechanisms of statin dependent CVD risk reduction. PMID:26273092

  14. Current-induced forces: a new mechanism to induce negative differential resistance and current-switching effect in molecular junctions.

    PubMed

    Gu, Lei; Fu, Hua-Hua

    2015-12-04

    Current-induced forces can excite molecules, polymers and other low-dimensional materials, which in turn leads to an effective gate voltage through Holstein interaction. Here, by taking a short asymmetric DNA junction as an example, and using the Langevin approach, we find that when suppression of charge transport by the effective gate voltage surpasses the current increase from an elevated voltage bias, the current-voltage (I-V) curves display strong negative differential resistance (NDR) and perfect current-switching characteristics. The asymmetric DNA chain differs in mechanical stability under inverse voltages and the I-V curve is asymmetric about inverse biases, which can be used to understand recent transport experiments on DNA chains, and meanwhile provides a new strategy to realize NDR in molecular junctions and other low-dimensional quantum systems.

  15. Different types of exercise induce differential effects on neuronal adaptations and memory performance.

    PubMed

    Lin, Tzu-Wei; Chen, Shean-Jen; Huang, Tung-Yi; Chang, Chia-Yuan; Chuang, Jih-Ing; Wu, Fong-Sen; Kuo, Yu-Min; Jen, Chauying J

    2012-01-01

    Different exercise paradigms show differential effects on various forms of memory. We hypothesize that the differential effects of exercises on memory performance are caused by different neuroplasticity changes in relevant brain regions in response to different exercise trainings. We examined the effects of treadmill running (TR) and wheel running (WR) on the Pavlovian fear conditioning task that assesses learning and memory performance associated with the amygdala (cued conditioning) and both the amygdala and hippocampus (contextual conditioning). The skeletal muscle citrate synthase activity, an indicator of aerobic capacity, was elevated in rats received 4 w of TR, but not WR. While both TR and WR elevated the contextual conditional response, only TR facilitated the cued conditional response. Using a single-neuron labeling technique, we found that while both TR and MR enlarged the dendritic field and increased the spine density in hippocampal CA3 neurons, only TR showed these effects in basolateral amygdalar neurons. Moreover, both types of exercise upregulated synaptic proteins (i.e., TrkB and SNAP-25) in the hippocampus; however only TR showed similar effects in the amygdala. Injection of K252a, a TrkB kinase inhibitor, in the dorsal hippocampus or basolateral amygdala abolished the exercise-facilitated contextual or cued fear learning and memory performance, respectively, regardless of the types of exercise. In summary, our results supported that different types of exercise affect the performance of learning and memory via BDNF-TrkB signaling and neuroplasticity in specific brain regions. The brain region-specific neuronal adaptations are possibly induced by various levels of intensity/stress elicited by different types of exercise.

  16. Differential Effects of Stress-induced Cortisol Responses on Recollection and Familiarity-based Recognition Memory

    PubMed Central

    McCullough, Andrew M.; Ritchey, Maureen; Ranganath, Charan; Yonelinas, Andrew

    2015-01-01

    Stress-induced changes in cortisol can impact memory in various ways. However, the precise relationship between cortisol and recognition memory is still poorly understood. For instance, there is reason to believe that stress could differentially affect recollection-based memory, which depends on the hippocampus, and familiarity-based recognition, which can be supported by neocortical areas alone. Accordingly, in the current study we examined the effects of stress-related changes in cortisol on the processes underlying recognition memory. Stress was induced with a cold-pressor test after incidental encoding of emotional and neutral pictures, and recollection and familiarity-based recognition memory were measured one day later. The relationship between stress-induced cortisol responses and recollection was non-monotonic, such that subjects with moderate stress-related increases in cortisol had the highest levels of recollection. In contrast, stress-related cortisol responses were linearly related to increases in familiarity. In addition, measures of cortisol taken at the onset of the experiment showed that individuals with higher levels of pre-learning cortisol had lower levels of both recollection and familiarity. The results are consistent with the proposition that hippocampal-dependent memory processes such as recollection function optimally under moderate levels of stress, whereas more cortically-based processes such as familiarity are enhanced even with higher levels of stress. These results indicate that whether post-encoding stress improves or disrupts recognition memory depends on the specific memory process examined as well as the magnitude of the stress-induced cortisol response. PMID:25930175

  17. Differential effects of stress-induced cortisol responses on recollection and familiarity-based recognition memory.

    PubMed

    McCullough, Andrew M; Ritchey, Maureen; Ranganath, Charan; Yonelinas, Andrew

    2015-09-01

    Stress-induced changes in cortisol can impact memory in various ways. However, the precise relationship between cortisol and recognition memory is still poorly understood. For instance, there is reason to believe that stress could differentially affect recollection-based memory, which depends on the hippocampus, and familiarity-based recognition, which can be supported by neocortical areas alone. Accordingly, in the current study we examined the effects of stress-related changes in cortisol on the processes underlying recognition memory. Stress was induced with a cold-pressor test after incidental encoding of emotional and neutral pictures, and recollection and familiarity-based recognition memory were measured one day later. The relationship between stress-induced cortisol responses and recollection was non-monotonic, such that subjects with moderate stress-related increases in cortisol had the highest levels of recollection. In contrast, stress-related cortisol responses were linearly related to increases in familiarity. In addition, measures of cortisol taken at the onset of the experiment showed that individuals with higher levels of pre-learning cortisol had lower levels of both recollection and familiarity. The results are consistent with the proposition that hippocampal-dependent memory processes such as recollection function optimally under moderate levels of stress, whereas more cortically-based processes such as familiarity are enhanced even with higher levels of stress. These results indicate that whether post-encoding stress improves or disrupts recognition memory depends on the specific memory process examined as well as the magnitude of the stress-induced cortisol response.

  18. Differentiation-inducing effects of betamethasone on human glioma cell line U251.

    PubMed

    Jin, T; Wang, Y X; Fan, K; Tao, D B; Dong, X; Shen, J S

    2015-07-14

    We studied the differentiation-inducing effect of beta-methasone on human glioma cell line U251 cultured in vitro, and the underlying mechanism. U251 cells were divided into two groups: control group cells, cultured in Dulbecco's Modified Eagle's medium containing 10% fetal bovine serum; and medication group cells, treated with 15 μM betamethasone. Morphological cell changes were observed by inverted microscope, cell cycle changes were ascertained by flow cytometry, and vimentin expression was checked by immunocytochemistry. The expression levels of extracellular signal-regulated protein ki-nase (ERK), phosphorylated ERK (pERK), and glial fibrillary acidic protein (GFAP) were assessed by western blot. Compared with the control group, U251 cell processes increased significantly, but declined 96 h after betamethasone took effect. After 48 h, the percentage of S-phase cells decreased significantly (28.77 to 20.42%; P = 0.014); the percent-age of strongly positive vimentin cells decreased significantly (91 to 51%; P = 0.0092); and the ratio of expression of GFAP protein to the internal control β-actin increased significantly (0.24 to 0.53; P = 0.1). The level of ERK protein did not change significantly 48 and 96 h after the action of betamethasone, and the pERK/ERK ratios were 0.37 and 0.23, respectively, which were significantly reduced compared with the control group (P = 0.028 and 0.006). Betamethasone has a significant effect on the induction and differentiation of U251 cells, and its mechanism may be related to the inhibition of the abnormal activation of the ERK signal pathway.

  19. Differential inhibitory effect on human nociceptive skin senses induced by local stimulation of thin cutaneous fibers.

    PubMed

    Nilsson, H J; Schouenborg, J

    1999-03-01

    It is known that stimulation of thin cutaneous nerve fibers can induce long lasting analgesia through both supraspinal and segmental mechanisms, the latter often exhibiting restricted receptive fields. On this basis, we recently developed a new method, termed cutaneous field stimulation (CFS), for localized stimulation of A delta and C fibers in the superficial part of the skin. In the present study, we have evaluated the effects of CFS on non-nociceptive and nociceptive skin senses. We compared the effects of CFS with those of conventional transcutaneous electrical nerve stimulation (TENS), known to preferentially activate coarse myelinated fibers. A battery of sensory tests were made on the right volar forearm of 20 healthy subjects. CFS (16 electrodes, 4 Hz per electrode, 1 ms, up to 0.8 mA) and TENS (100 Hz, 0.2 ms, up to 26 mA) applied either on the right volar forearm (homotopically), or on the lower right leg (heterotopically) were used as conditioning stimulation for 25 min. The tactile threshold was not affected by either homo- or heterotopical CFS or TENS. The mean thresholds for detecting warming or cooling of the skin were increased by 0.4-0.9 degrees C after homo- but not heterotopical CFS and TENS. Regarding nociceptive skin senses, homo- but not heterotopical CFS, markedly reduced CO2-laser evoked A delta- and C fiber mediated heat pain to 75 and 48% of control, respectively, and mechanically evoked pain to 73% of control. Fabric evoked prickle, was not affected by CFS. Neither homo- nor heterotopical TENS induced any marked analgesic effects. It is concluded that different qualities of nociception can be differentially controlled by CFS.

  20. Inhibitory effect of leptin on rosiglitazone-induced differentiation of primary adipocytes prepared from TallyHO/Jng mice

    SciTech Connect

    Kim, Ki Young; Kim, Joo Young; Sung, Yoon-Young; Jung, Won Hoon; Kim, Hee-Youn; Park, Ji Seon; Cheon, Hyae Gyeong; Rhee, Sang Dal

    2011-03-25

    Research highlights: {yields} In this study, we investigated the effects of leptin on adipocyte differentiation prepared from subcutaneous fat of TallyHo mice. {yields} Leptin inhibited the adipocytes differentiation at physiological concentration via inhibition of PPAR{gamma} expression. {yields} Inhibitors of ERK and STAT1 restored the leptin's inhibitory activity both in vitro and in vivo. -- Abstract: The effects of leptin on rosiglitazone-induced adipocyte differentiation were investigated in the primary adipocytes prepared from subcutaneous fat of TallyHO/Jng (TallyHO) mouse, a recently developed model animal for type 2 diabetes mellitus (T2DM). The treatment of leptin inhibited the rosiglitazone-induced adipocyte differentiation with a decreased expression of peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}) a key adipogenic transcription factor, both in mRNA and protein levels. Leptin (10 nM) was sufficient to inhibit the adipocyte differentiation, which seemed to come from increased expression of leptin receptor genes in the fat of TallyHO mice. The inhibition of adipogenesis by leptin was restored by the treatment of inhibitors for extracellular-signal-regulated kinase (ERK) (PD98059) and signal transducer and activator of transcription-1 (STAT1) (fludarabine). Furthermore, in vivo intraperitoneal administration of PD98059 and fludarabine increased the PPAR{gamma} expression in the subcutaneous fat of TallyHO mice. These data suggest that leptin could inhibit the PPAR{gamma} expression and adipocyte differentiation in its physiological concentration in TallyHO mice.

  1. PED/PEA-15 induces autophagy and mediates TGF-beta1 effect on muscle cell differentiation.

    PubMed

    Iovino, S; Oriente, F; Botta, G; Cabaro, S; Iovane, V; Paciello, O; Viggiano, D; Perruolo, G; Formisano, P; Beguinot, F

    2012-07-01

    TGF-beta1 has been shown to induce autophagy in certain cells but whether and how this action is exerted in muscle and whether this activity relates to TGF-beta1 control of muscle cell differentiation remains unknown. Here, we show that expression of the autophagy-promoting protein phosphoprotein enriched in diabetes/phosphoprotein enriched in astrocytes (PED/PEA-15) progressively declines during L6 and C2C12 skeletal muscle cell differentiation. PED/PEA-15 underwent rapid induction upon TGF-beta1 exposure of L6 and C2C12 myoblasts, accompanied by impaired differentiation into mature myotubes. TGF-beta1 also induced autophagy in the L6 and C2C12 cells through a PP2A/FoxO1-mediated mechanism. Both the TGF-beta1 effect on differentiation and that on autophagy were blocked by specific PED/PEA-15 ShRNAs. Myoblasts stably overexpressing PED/PEA-15 did not differentiate and showed markedly enhanced autophagy. In these same cells, the autophagy inhibitor 3-methyladenine rescued TGF-beta1 effect on both autophagy and myogenesis, indicating that PED/PEA-15 mediates TGF-beta1 effects in muscle. Muscles from transgenic mice overexpressing PED/PEA-15 featured a significant number of atrophic fibers, accompanied by increased light chain 3 (LC3)II to LC3I ratio and reduced PP2A/FoxO1 phosphorylation. Interestingly, these mice showed significantly impaired locomotor activity compared with their non-transgenic littermates. TGF-beta1 causes transcriptional upregulation of the autophagy-promoting gene PED/PEA-15, which in turn is capable to induce atrophic responses in skeletal muscle in vivo.

  2. Differential effects of hypoxic and hyperoxic stress-induced hypertrophy in cultured chick fetal cardiac myocytes.

    PubMed

    Greco, Allison A; Gomez, George

    2014-02-01

    The adult heart responds to contraction demands by hypertrophy, or enlargement, of cardiac myocytes. Adaptive hypertrophy can occur in response to hyperoxic conditions such as exercise, while pathological factors that result in hypoxia ultimately result in heart failure. The difference in the outcomes produced by pathologically versus physiologically induced hypertrophy suggests that the cellular signaling pathways or conditions of myocytes may be different at the cellular level. The structural and functional changes in myocytes resulting from hyperoxia (simulated using hydrogen peroxide) and hypoxia (using oxygen deprivation) were tested on fetal chick cardiac myocytes grown in vitro. Structural changes were measured using immunostaining for α-sarcomeric actin or MyoD, while functional changes were assessed using immunostaining for calcium/calmodulin-dependent kinase (CaMKII) and by measuring intracellular calcium fluxes using live cell fluorescence imaging. Both hypoxic and hyperoxic stress resulted in an upregulation of actin and MyoD expression. Similarly, voltage-gated channels governing myocyte depolarization and the regulation of CaMK were unchanged by hyperoxic or hypoxic conditions. However, the dynamic features of calcium fluxes elicited by caffeine or epinephrine were different in cells subjected to hypoxia versus hyperoxia, suggesting that these different conditions differentially affect components of ligand-activated signaling pathways that regulate calcium. Our results suggest that changes in signaling pathways, rather than structural organization, may mediate the different outcomes associated with hyperoxia-induced versus hypoxia-induced hypertrophy, and these changes are likely initiated at the cellular level.

  3. The effects of Lycii Radicis Cortex on RANKL-induced osteoclast differentiation and activation in RAW 264.7 cells

    PubMed Central

    KIM, JAE-HYUN; KIM, EUN-YOUNG; LEE, BINA; MIN, JU-HEE; SONG, DEA-UK; LIM, JEONG-MIN; EOM, JI WHAN; YEOM, MIJUNG; JUNG, HYUK-SANG; SOHN, YOUNGJOO

    2016-01-01

    Post-menopausal osteoporosis is a serious age-related disease. After the menopause, estrogen deficiency is common, and excessive osteoclast activity causes osteoporosis. Osteoclasts are multinucleated cells generated from the differentiation of monocyte/macrophage precursor cells such as RAW 264.7 cells. The water extract of Lycii Radicis Cortex (LRC) is made from the dried root bark of Lycium chinense Mill. and is termed 'Jigolpi' in Korea. Its effects on osteoclastogenesis and post-menopausal osteoporosis had not previously been tested. In the present study, the effect of LRC on receptor activator of nuclear factor-κB (NF-κB) ligand (RANKL)-induced osteoclast differentiation was demonstrated using a tartrate-resistant acid phosphatase (TRAP) assay and pit formation assay. Moreover, in order to analyze molecular mechanisms, we studied osteoclastogenesis-related markers such as nuclear factor of activated T-cells cytoplasmic 1 (NFATc1), c-Fos, receptor activator of NF-κB (RANK), TRAP, cathepsin K (CTK), matrix metallopeptidase-9 (MMP-9), calcitonin receptor (CTR) and carbonic anhydrase II (CAII) using RT-qPCR and western blot analysis. Additionally, we also determined the effect of LRC on an ovariectomized (OVX) rat model. We noted that LRC inhibited RANKL-induced osteoclast differentiation via suppressing osteoclastogenesis-related markers. It also inhibited osteoporosis in the OVX rat model by decreasing loss of bone density and trabecular area. These results suggest that LRC exerts a positive effect on menopausal osteoporosis. PMID:26848104

  4. Effect of copper-induced oxidative stress on sclerotial differentiation and antioxidants contents of Penicillium thomii Q1.

    PubMed

    Zhao, Wen-Jing; An, Cui-Hong; Long, Dan-Dan; Zhang, Zhe-Qing; Han, Jian-Rong

    2014-12-01

    Penicillium thomii Q1 strain was able to form abundant orange, sand-shaped sclerotia in which carotenoids were accumulated. The aim of this work was to determine the effects of copper-induced oxidative stress on the sclerotial differentiation, biosynthesis of some endogenous antioxidants, and the activities of some antioxidative enzymes of Q1 strain. The results showed that the oxidative stress induced by copper was clearly dependent on the CuSO4 concentrations in media, and characterized by the initiation of lipid peroxidation. Under the copper-induced oxidative stress conditions, the time of exudates initiation, sclerotial initiation and sclerotial maturation of Q1 strain were advanced in 1-2 days. The analytical results of sclerotial biomass, carotenoids, and ascorbate contents showed that copper-induced oxidative stress favored the sclerotial differentiation and biosynthesis of carotenoids and ascorbate. The oxidative stress induced by a lower amount of CuSO4 in media could enhance significantly the superoxide dismutase and catalase activities of Q1 strain.

  5. Nanopit-induced osteoprogenitor cell differentiation: The effect of nanopit depth

    PubMed Central

    Davison, Martin J; McMurray, Rebecca J; Smith, Carol-Anne; Dalby, Matthew J; Meek, RM Dominic

    2016-01-01

    We aimed to assess osteogenesis in osteoprogenitor cells by nanopits and to assess optimal feature depth. Topographies of depth 80, 220 and 333 nm were embossed onto polycaprolactone discs. Bone marrow–derived mesenchymal stromal cells were seeded onto polycaprolactone discs, suspended in media and incubated. Samples were fixed after 3 and 28 days. Cells were stained for the adhesion molecule vinculin and the osteogenic transcription factor RUNX2 after 3 days. Adhesion was lowest on planar controls and it was the shallowest, and 80-nm-deep pits supported optimal adhesion formation. Deep pits (80 and 220 nm) induced most RUNX2 accumulation. After 28 days, osteocalcin and osteopontin expression were used as markers of osteoblastic differentiation. Deep pits (220 nm) produced cells with the highest concentrations of osteopontin and osteocalcin. All topographies induced higher expression levels than controls. We demonstrated stimulation of osteogenesis in a heterogeneous population of mesenchymal stromal cells. All nanopit depths gave promising results with an optimum depth of 220 nm after 28 days. Nanoscale modification of implant surfaces could optimise fracture union or osteointegration. PMID:27298716

  6. Differential effects of radical scavengers on X-ray-induced mutation and cytotoxicity in human cells

    SciTech Connect

    Corn, B.W.; Liber, H.L.; Little, J.B.

    1987-01-01

    The cytotoxic and mutagenic effects of X irradiation on a human lymphoblast cell line were examined in the presence of two radioprotective agents which modulate damage to DNA. The cells were treated with X rays alone or in the presence of either dimethyl sulfoxide or cysteamine. Surviving fraction and mutation to trifluorothymidine resistance (tk locus) and to 6-thioguanine resistance (hgprt locus) were measured. Survival was enhanced when the cells were irradiated in the presence of dimethyl sulfoxide; the D0 rose from 58 to 107 rad. However, at both genetic loci the induced mutant fractions were identical in the presence or absence of dimethyl sulfoxide. Survival was enhanced to a greater degree when the cells were irradiated in the presence of cysteamine; the D0 rose from 58 to 200 rad. Cysteamine also protected the cells from X-ray-induced mutation; the frequencies of X-ray-induced mutation at both the tk and hgprt loci were reduced by 50-75%. No protective effects were observed unless dimethyl sulfoxide or cysteamine was present during irradiation. These findings are discussed in terms of the hypothesis that, unlike for cell killing, radiation-induced mutagenesis in human lymphoblast cells is not mediated by the actions of aqueous free radicals, but rather by the direct effects of ionizing radiation.

  7. Differential effects of propranolol on conditioned hyperactivity and locomotor sensitization induced by morphine in rats.

    PubMed

    Wei, Shuguang; Li, Xinwang

    2014-01-21

    According to memory reconsolidation theory, when long-term memory is reactivated by relevant clues, the memory traces become labile, which can be altered by pharmacological manipulations. Accumulating evidence reveals that memory related to drug abuse can be erased by disrupting reconsolidation process. We used an animal model that could simultaneously measure conditioned hyperactivity and locomotor sensitization induced by morphine. β-Adrenoceptor antagonist propranolol or saline were administered following conditioned stimuli (CS) or a small dose of morphine reactivation. The results showed that the conditioned hyperactivity could be disrupted by propranolol treatment following CS reactivation. However, the expression of locomotor sensitization could not be disrupted by propranolol administration following CS or morphine reactivation. Furthermore, morphine injection and propranolol intervention enhanced the locomotor sensitization effect. These data suggest that blocking the reconsolidation process can disrupt the conditioned hyperactivity induced by environmental cues associated with morphine treatment, but not morphine-induced locomotor sensitization.

  8. Differential effects of amphetamines-induced neurotoxicity on appetitive and aversive Pavlovian conditioning in mice.

    PubMed

    Achat-Mendes, Cindy; Ali, Syed F; Itzhak, Yossef

    2005-06-01

    The abuse of substituted amphetamines such as methamphetamine (METH) and 3,4-methylenedioxymethamphetamine (MDMA/Ecstasy) can result in neurotoxicity, manifested as the depletion of dopamine (DA) and 5-hydroxytriptamine (5-HT; serotonin) axon terminal markers in humans and animal models. Human METH and MDMA users exhibit impairments in memory and executive functions, which may be a direct consequence of the neurotoxic potential of amphetamines. The objective of this study was to investigate the influence of amphetamines-induced neurotoxicity on Pavlovian learning. Using mouse models of selective DA neurotoxicity (METH; 5 mg/kg x 3), selective 5-HT neurotoxicity (fenfluramine /FEN; 25 mg/kg x 4) and dual DA and 5-HT neurotoxicity (MDMA; 15 mg/kg x 4), appetitive and aversive conditioning were investigated. Dopaminergic neurotoxicity significantly impaired METH and cocaine conditioned place preference (CPP), but had no effect on LiCl-induced conditioned place aversion (CPA). In contrast, serotonergic neurotoxicity significantly enhanced CPP, and had no effect on CPA. Dual dopaminergic/serotonergic neurotoxicity had no apparent effect on CPP; however, CPA was significantly attenuated. Postmortem analysis revealed that significantly diminished levels of DA and 5-HT markers persisted in the striatum, frontal cortex, hippocampus, and amygdala. These findings suggest that amphetamines-induced dopaminergic and serotonergic neurotoxicity exert opposing influences on the affective state produced by subsequent drug reward, while dual dopaminergic/serotonergic neurotoxicity impairs associative learning of aversive conditioning. Furthermore, results revealed that amphetamines-induced DA and 5-HT neurotoxicity modulates appetitive Pavlovian conditioning similar to other DA and 5-HT neurotoxins. Modulation of Pavlovian conditioning by amphetamines-induced neurotoxicity may be relevant to compulsive drug-seeking behavior in METH and MDMA abusers.

  9. Differential effects of the ascorbyl and tocopheryl derivative on the methamphetamine-induced toxic behavior and toxicity.

    PubMed

    Ito, Shinobu; Mori, Tomohisa; Kanazawa, Hideko; Sawaguchi, Toshiko

    2007-10-30

    A previous study showed that high doses of methamphetamine induce self-injurious behavior (SIB) in rodents. Furthermore, the combination of methamphetamine and morphine increased lethality in mice. We recently surmised that the rise in SIB and mortality induced by methamphetamine and/or morphine may be related to oxidative stress. The present study was designed to determine whether an antioxidant could inhibit SIB or mortality directly induced by methamphetamine and/or morphine. The SIB induced by 20mg/kg of methamphetamine was abolished by the administration of Na L-ascorbyl-2-phosphate (APS: 300 mg/kg), but not Na DL-alpha-tocopheryl phosphate (TPNa: 200mg/kg). In contrast, APS (300 mg/kg) and TPNa (200mg/kg) each significantly attenuated the lethality induced by methamphetamine and morphine. The present study showed that the signal intensity of superoxide adduct was increased by 20mg/kg of methamphetamine in the heart and lungs, and methamphetamine plus morphine tended to increase superoxide adduct in all of the tissues measured by ESR spin trap methods. Adduct signal induced in brain by methamphetamine administration increased in significance, but in mouse administrated methamphetamine plus morphine. There are differential effects of administration of methamphetamine and coadministration of methamphetamine plus morphine on adduct signal. These results suggest that APS and TPNa are effective for reducing methamphetamine-induced toxicity and/or toxicological behavior. While APS and TPNa each affected methamphetamine- and/or morphine-induced toxicology and/or toxicological behavior, indicating that both drugs have antioxidative effects, their effects differed.

  10. SCH 58261 differentially influences quinolinic acid-induced effects in striatal and in hippocampal slices.

    PubMed

    Tebano, Maria Teresa; Domenici, Maria Rosaria; Popoli, Patrizia

    2002-08-30

    The influence of the adenosine A(2A) receptor antagonist SCH 58261 (7-(2-phenylethyl)-5-amino-2-(2-furyl)-pyrazolo-[4,3-e]-1,2,4-trizolo[1,5-c] pyrimidine) (50, 200 nM, 1 microM) on quinolinic acid effects has been studied in rat striatal and hippocampal slices. Quinolinic acid induced disappearance of field potentials at concentrations of 500 microM and 2 mM in hippocampal and corticostriatal slices, respectively. We found that 1 microM SCH 58261 prevented quinolinic acid-induced field potential disappearance in corticostriatal but not in hippocampal slices. This finding demonstrates that the peculiar binding profile of SCH 58261 and the predominance in the hippocampus of "atypical" adenosine A(2A) receptor population (not recognized by SCH 58261) could have a functional relevance in the occurrence of region-specific neuroprotective effects.

  11. Differential effects of microsomal enzyme inducers on in vitro thyroxine (T(4)) and triiodothyronine (T(3)) glucuronidation.

    PubMed

    Hood, A; Klaassen, C D

    2000-05-01

    Microsomal enzyme inducers that increase UDP-glucuronosyltransferase (UDP-GT) activity are suspected to affect the thyroid gland by increasing the glucuronidation of T(4), which reduces serum thyroxine (T(4)). In response to reduced serum T(4), serum thyroid-stimulating hormone (TSH) increases. However, not all microsomal enzyme inducers that reduce serum T(4) produce an increase in serum TSH. We have shown that serum TSH is increased the most in rats treated with the microsomal enzyme inducers phenobarbital (PB) or pregnenolone-16alpha-carbonitrile (PCN), whereas TSH is affected less in rats treated with 3-methylcholanthrene (3MC) and Aroclor 1254 (PCB). It is unclear why serum TSH is differentially affected by various microsomal enzyme inducers. We propose that the glucuronidation of T(3) might be the reason serum TSH is increased by some microsomal enzyme inducers but not by others. Male Sprague-Dawley rats were fed either a basal diet or a diet containing PB (at 300, 600, 1200, or 2400 ppm), PCN (at 200, 400, 800, or 1600 ppm), 3MC (at 50, 100, 200, or 400 ppm), or PCB (at 25, 50, 100, or 200 ppm) for 7 days; and T(4) and T(3) UDP-GT activities were then determined. T(4) UDP-GT activity was increased in rats treated with PB (120%), PCN (250 to 400%), 3MC (400 to 600%), or PCB (300 to 430%). In contrast, T(3) UDP-GT activity was increased in rats treated with PB (90%) or PCN (120 to 200%), whereas 3MC and PCB treatments did not have an appreciable effect. In conclusion, differential effects on T(3) glucuronosyltransferase activity were found in rats treated with microsomal enzyme inducers.

  12. The effect of magnetic nanoparticles on neuronal differentiation of induced pluripotent stem cell-derived neural precursors

    PubMed Central

    Jiráková, Klára; Šeneklová, Monika; Jirák, Daniel; Turnovcová, Karolína; Vosmanská, Magda; Babič, Michal; Horák, Daniel; Veverka, Pavel; Jendelová, Pavla

    2016-01-01

    Introduction Magnetic resonance (MR) imaging is suitable for noninvasive long-term tracking. We labeled human induced pluripotent stem cell-derived neural precursors (iPSC-NPs) with two types of iron-based nanoparticles, silica-coated cobalt zinc ferrite nanoparticles (CZF) and poly-l-lysine-coated iron oxide superparamagnetic nanoparticles (PLL-coated γ-Fe2O3) and studied their effect on proliferation and neuronal differentiation. Materials and methods We investigated the effect of these two contrast agents on neural precursor cell proliferation and differentiation capability. We further defined the intracellular localization and labeling efficiency and analyzed labeled cells by MR. Results Cell proliferation was not affected by PLL-coated γ-Fe2O3 but was slowed down in cells labeled with CZF. Labeling efficiency, iron content and relaxation rates measured by MR were lower in cells labeled with CZF when compared to PLL-coated γ-Fe2O3. Cytoplasmic localization of both types of nanoparticles was confirmed by transmission electron microscopy. Flow cytometry and immunocytochemical analysis of specific markers expressed during neuronal differentiation did not show any significant differences between unlabeled cells or cells labeled with both magnetic nanoparticles. Conclusion Our results show that cells labeled with PLL-coated γ-Fe2O3 are suitable for MR detection, did not affect the differentiation potential of iPSC-NPs and are suitable for in vivo cell therapies in experimental models of central nervous system disorders. PMID:27920532

  13. Sox9 potentiates BMP2-induced chondrogenic differentiation and inhibits BMP2-induced osteogenic differentiation.

    PubMed

    Liao, Junyi; Hu, Ning; Zhou, Nian; Lin, Liangbo; Zhao, Chen; Yi, Shixiong; Fan, Tingxu; Bao, Wei; Liang, Xi; Chen, Hong; Xu, Wei; Chen, Cheng; Cheng, Qiang; Zeng, Yongming; Si, Weike; Yang, Zhong; Huang, Wei

    2014-01-01

    Bone morphogenetic protein 2 (BMP2) is one of the key chondrogenic growth factors involved in the cartilage regeneration. However, it also exhibits osteogenic abilities and triggers endochondral ossification. Effective chondrogenesis and inhibition of BMP2-induced osteogenesis and endochondral ossification can be achieved by directing the mesenchymal stem cells (MSCs) towards chondrocyte lineage with chodrogenic factors, such as Sox9. Here we investigated the effects of Sox9 on BMP2-induced chondrogenic and osteogenic differentiation of MSCs. We found exogenous overexpression of Sox9 enhanced the BMP2-induced chondrogenic differentiation of MSCs in vitro. Also, it inhibited early and late osteogenic differentiation of MSCs in vitro. Subcutaneous stem cell implantation demonstrated Sox9 potentiated BMP2-induced cartilage formation and inhibited endochondral ossification. Mouse limb cultures indicated that BMP2 and Sox9 acted synergistically to stimulate chondrocytes proliferation, and Sox9 inhibited BMP2-induced chondrocytes hypertrophy and ossification. This study strongly suggests that Sox9 potentiates BMP2-induced MSCs chondrogenic differentiation and cartilage formation, and inhibits BMP2-induced MSCs osteogenic differentiation and endochondral ossification. Thus, exogenous overexpression of Sox9 in BMP2-induced mesenchymal stem cells differentiation may be a new strategy for cartilage tissue engineering.

  14. The effect of an alendronate-eluting titanium system to induce osteogenic differentiation in human buccal fat cells (HBFCs)

    NASA Astrophysics Data System (ADS)

    Kim, Sung Eun; Lee, Su-Young; Yun, Young-Pil; Lee, Jae Yong; Park, Kyeongsoon; Lee, Deok-Won; Song, Hae-Ryong

    2012-10-01

    The purpose of this study was to develop alendronate (Aln)-eluting Ti substrates to induce osteogenic differentiation of human buccal fat cells (HBFCs). The surface of pristine Ti was modified by dopamine (DOPA) and then heparin was grafted onto the aminated Ti surfaces to achieve the Aln-eluting Ti system. Aln was subsequently immobilized on the surface of heparinized Ti (Hep-Ti). Pristine Ti and surface-modified-Ti were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and contact angle. Osteogenic differentiation of HBFCs on the surface of pristine-Ti, Hep-Ti, Aln (1 mg)/Hep-Ti, and Aln (5 mg)/Hep-Ti was demonstrated by alkaline phosphatase (ALP) activity, calcium deposition, and osteocalcin and osteopontin mRNA expression. Successful immobilization of Aln on Hep-Ti was confirmed by XPS and contact angle. Aln/Hep-Ti showed the sustained release for up to 28 days. Additionally, HBFCs cultured on Aln/Hep-Ti substrates showed significantly induced ALP activity, calcium deposition, and osteocalcin and osteopontin mRNA expression. These results suggest that Aln-eluting Ti substrates have a potential effect on osteogenic differentiation of HBFCs and will be a promising material for bone regeneration.

  15. Differential effects of multiplicity of infection on Helicobacter pylori-induced signaling pathways and interleukin-8 gene transcription.

    PubMed

    Ritter, Birgit; Kilian, Petra; Reboll, Marc Rene; Resch, Klaus; DiStefano, Johanna Kay; Frank, Ronald; Beil, Winfried; Nourbakhsh, Mahtab

    2011-02-01

    Interleukin-8 (IL-8) plays a central role in the pathogenesis of Helicobacter pylori infection. We used four different H. pylori strains isolated from patients with gastritis or duodenal ulcer disease to examine their differential effects on signaling pathways and IL-8 gene response in gastric epithelial cells. IL-8 mRNA level is elevated in response to high (100) multiplicity of infection (MOI) independent of cagA, vacA, and dupA gene characteristics. By lower MOIs (1 or 10), only cagA ( + ) strains significantly induce IL-8 gene expression. This is based on differential regulation of IL-8 promoter activity. Analysis of intracellular signaling pathways indicates that H. pylori clinical isolates induce IL-8 gene transcription through NF-κB p65, but by a MOI-dependent differential activation of MAPK pathways. Thus, the major virulence factors of H. pylori CagA, VacA, and DupA might play a minor role in the level of IL-8 gene response to a high bacterial load.

  16. Tamoxifen enhances the differentiation-inducing and growth-inhibitory effects of all-trans retinoic acid in acute promyelocytic leukemia cells.

    PubMed

    Adachi, Koji; Honma, Yoshio; Miyake, Takaaki; Kawakami, Koshi; Takahashi, Tsutomu; Suzumiya, Junji

    2016-03-01

    All-trans retinoic acid (ATRA) is valuable in differentiation therapy for acute promyelocytic leukemia (APL). However, ATRA has had limited success as a single agent, due to the development of resistance. We found that tamoxifen effectively enhanced the differentiation-inducing effect of ATRA. Tamoxifen alone inhibited the proliferation of myeloid leukemia cell lines while only slightly increasing morphologic differentiation. Tamoxifen effectively enhanced the growth-inhibiting actions of various differentiation-inducing agents. ATRA in the presence of tamoxifen increased NBT reduction and the expression of CD11b in HL-60 cells more effectively than ATRA alone. Tamoxifen also enhanced the differentiation induced by the other inducers tested. ATRA induced the differentiation of APL cell lines NB4 and HT93 and APL cells in primary culture, and this differentiation was also enhanced by tamoxifen. Tamoxifen is one of the most widely used drugs for the treatment of cancer and has few side effects. The combination of ATRA and tamoxifen might be considered for the treatment of APL patients in whom it can be difficult to apply arsenic trioxide or anthracyclines.

  17. Differential Effectiveness of Clinically-Relevant Analgesics in a Rat Model of Chemotherapy-Induced Mucositis

    PubMed Central

    Whittaker, Alexandra L.; Lymn, Kerry A.; Wallace, Georgia L.; Howarth, Gordon S.

    2016-01-01

    Chemotherapy-induced intestinal mucositis is characterized by pain and a pro-inflammatory tissue response. Rat models are frequently used in mucositis disease investigations yet little is known about the presence of pain in these animals, the ability of analgesics to ameliorate the condition, or the effect that analgesic administration may have on study outcomes. This study investigated different classes of analgesics with the aim of determining their analgesic effects and impact on research outcomes of interest in a rat model of mucositis. Female DA rats were allocated to 8 groups to include saline and chemotherapy controls (n = 8). Analgesics included opioid derivatives (buprenorphine; 0.05mg/kg and tramadol 12.5mg/kg) and NSAID (carprofen; 15mg/kg) in combination with either saline or 5-Fluorouracil (5-FU; 150mg/kg). Research outcome measures included daily clinical parameters, pain score and gut histology. Myeloperoxidase assay was performed to determine gut inflammation. At the dosages employed, all agents had an analgesic effect based on behavioural pain scores. Jejunal myeloperoxidase activity was significantly reduced by buprenorphine and tramadol in comparison to 5-FU control animals (53%, p = 0.0004 and 58%, p = 0.0001). Carprofen had no ameliorating effect on myeloperoxidase levels. None of the agents reduced the histological damage caused by 5-FU administration although tramadol tended to increase villus length even when administered to healthy animals. These data provide evidence that carprofen offers potential as an analgesic in this animal model due to its pain-relieving efficacy and minimal effect on measured parameters. This study also supports further investigation into the mechanism and utility of opioid agents in the treatment of chemotherapy-induced mucositis. PMID:27463799

  18. Methyllycaconitine- and scopolamine-induced cognitive dysfunction: differential reversal effect by cognition-enhancing drugs

    PubMed Central

    Andriambeloson, Emile; Huyard, Bertrand; Poiraud, Etienne; Wagner, Stéphanie

    2014-01-01

    There is a growing body of evidence pointing to the pivotal role of alpha-7 nicotinic acetylcholine receptor (α7 nAchR) dysfunction in cognitive disorders such as Alzheimer’s disease or schizophrenia. This study was undertaken to establish and characterize an in vivo model for cognitive disorder secondary to the blockade of α7 nAChR by its specific antagonist, methyllycaconitine (MLA). The results show that MLA elicited cognitive dysfunction as assessed by reduced spontaneous alternation of mice in the T-maze. The maximal effect of MLA produced 25–30% reduction in the spontaneous alternation of mice, a level comparable with that induced by the muscarinic antagonism of scopolamine. Donepezil and galantamine fully reversed both MLA and scopolamine-induced cognitive dysfunction. However, the ED50 of donepezil and galantamine was significantly shifted to the left in the MLA- compared to scopolamine-treated mice (0.0005 and 0.002 mg/kg for donepezil; 0.0003 and 0.7 mg/kg for galantamine). Moreover, memantine elicited marked reversion of cognitive dysfunction (up to 70%) in MLA-treated mice while only a weak reversal effect at high dose of memantine (less than 20%) was observed in scopolamine-treated mice. The above findings indicate that MLA-induced cognitive dysfunction in the mouse is highly sensitive and more responsive to the current procognitive drugs than the traditional scopolamine-based assay. Thus, it can be of value for the preclinical screening and profiling of cognition-enhancing drugs. PMID:25505596

  19. IL-27 controls the development of inducible regulatory T cells and Th17 cells via differential effects on STAT1.

    PubMed

    Neufert, Clemens; Becker, Christoph; Wirtz, Stefan; Fantini, Massimo C; Weigmann, Benno; Galle, Peter R; Neurath, Markus F

    2007-07-01

    IL-27 is an IL-12-related cytokine frequently present at sites of inflammation that can promote both anti- and pro-inflammatory immune responses. Here, we have analyzed the mechanisms how IL-27 may drive such divergent immune responses. While IL-27 suppressed the development of proinflammatory Th17 cells, a novel role for this cytokine in inhibiting the development of anti-inflammatory, inducible regulatory T cells (iTreg) was identified. In fact, IL-27 suppressed the development of adaptive, TGF-beta-induced Forkhead box transcription factor p3-positive (Foxp3(+)) Treg. Whereas the blockade of Th17 development was dependent on the transcription factor STAT1, the suppression of iTreg development was STAT1 independent, suggesting that IL-27 utilizes different signaling pathways to shape T cell-driven immune responses. Our data thus demonstrate that IL-27 controls the development of Th17 and iTreg cells via differential effects on STAT1.

  20. PRELIMINARY OBSERVATIONS OF ATRAZINE-INDUCED EFFECTS UPON GONADAL DIFFERENTIATION IN RIVULUS MARMORATUS, A NATURALLY HERMAPHRODITIC FISH

    EPA Science Inventory

    The commonly used agricultural herbicide atrazine has been recognized as an endocrine disrupting chemical. In amphibians and reptiles, atrazine has been reported to alter sexual differentiation and induce secondary sexual characteristics that have been attributed to enhanced arom...

  1. Therapeutic Effects of Erythroid Differentiation Regulator 1 on Imiquimod-Induced Psoriasis-Like Skin Inflammation.

    PubMed

    Kim, Kyung Eun; Houh, Younkyung; Park, Hyun Jeong; Cho, Daeho

    2016-02-17

    Psoriasis is a common skin disease accompanied by chronic inflammation. In previous studies, erythroid differentiation regulator 1 (ERDR1) was shown to have a negative correlation with proinflammatory cytokine IL-18. However, the role of ERDR1 in the inflammatory skin disease psoriasis has not been evaluated. In this study, to investigate the role of ERDR1 in psoriasis, recombinant ERDR1 was injected intraperitoneally into a psoriasis mouse model. Recombinant ERDR1 (rERDR1) significantly alleviated the symptoms of psoriasis-like skin inflammation and reduced the mRNA of various psoriasis-related markers, including keratin 14, S100A8, and Th17-related cytokines IL-17 and IL-22, suggesting that rERDR1 exerts therapeutic effects on psoriasis via the regulation of Th17 functions. Additionally, the expression of CCL20, a well-known Th17 attracting chemokine, was determined. CCL20 expression significantly decreased in the rERDR1-injected group compared with the vehicle (PBS)-injected group. CCR6 expression in the psoriatic lesional skin was also decreased by rERDR1 administration, implying the inhibition of CCR6-expressing Th17 cell chemotaxis via the downregulation of CCL20. Taken together, this study provides the first evidence that ERDR1 may be a potential therapeutic target for psoriasis.

  2. Differential effects of luminol, nickel, and arsenite on the rejoining of ultraviolet light and alkylation-induced DNA breaks

    SciTech Connect

    Lee-Chen, S.F.; Yu, C.T.; Wu, D.R.

    1994-12-31

    When Chinese hamster ovary cells were treated with ultraviolet (UV) light or methyl methane-sulfonate (MMS), a large number of DNA strand breaks could be detected by alkaline elution. These strand breaks gradually disappeared if the treated cells were allowed to recover in a drug-free medium. The presence of nickel or arsenite during the recovery incubation retarded the disappearance of UV-induced strand breaks, whereas the disappearance of MMS-induced strand breaks was retarded by the presence of arsenite or of luminol, a new inhibit for poly(ADP-ribose) synthetase. Luminol, however, had no apparent effect on the repair of UV-induced DNA strand breaks, and nickel had no effect on the repair of MMS-induced DNA strand breaks. When UV- or MMS-treated cells were incubated in cytosine arabinofuranoside (AraC) plus hydroxyurea (HU), a large amount of low molecular weight DNA was detected by alkaline sucrose sedimentation. The molecular weight of these DNAs increased if the cells were further incubated in a drug-free medium. This rejoining of breaks in cells pretreated with UV plus AraC and HU was inhibited by nickel and by arsenite, but not by luminol. The rejoining of breaks in cells pretreated with MMS plus AraC and HU was inhibited by luminol and by arsenite, but not by nickel. These results suggest that different enzymes may be used in DNA resynthesis and/or ligation during the repairing of UV- and MMS-induced DNA strand breaks, and that nickel, luminol, and arsenite may have differential inhibitory effects on these enzymes. 29 refs., 4 figs., 1 tab.

  3. Differential Effects of Furnidipines’ Metabolites on Reperfusion-Induced Arrhythmias in Rats In Vivo

    PubMed Central

    Mitrega, Katarzyna A.; Porc, Maurycy; Krzeminski, Tadeusz F.

    2014-01-01

    We previously established that furnidipine (FUR) and oxy dihydropyridines prevent rats mortality by strong reduction of the lethal arrhythmias in reperfusion. Therefore we decided to study the influence of three main metabolites (M-2, M-3, M-8) of FUR on ischemia-and reperfusion- induced arrhythmias and hemodynamic parameters in rat model to examine their independent activity. The metabolites (M-2, M-3, M-8) were given orally 20 mg/kg (24 and 1 h before ischemia). Mortality was significantly diminished in M-2 and M-3 treated groups with M-3 preventing animal mortality entirely. All three examined substances significantly reduced the duration and incidence of ventricular fibrillation (VF) with M-3, once again, completely preventing VF. Moreover, only M-3 significantly decreased the duration of ventricular tachycardia but had no influence on their incidence. Through the occlusion and reperfusion periods, M-2 and M-3 were markedly less hypotensive than M-8 and did not influence on heart rate. We conclude that two tested metabolites of FUR, M-3 and M-2 exhibited the most pronounced anti-arrhythmic effect being at the same time the most normotensive and therefore caused the most beneficial effects. PMID:24586808

  4. The role of COX-2 in mediating the effect of PTEN on BMP9 induced osteogenic differentiation in mouse embryonic fibroblasts.

    PubMed

    Huang, Jun; Yuan, Shuang-Xue; Wang, Dong-Xu; Wu, Qiu-Xiang; Wang, Xing; Pi, Chang-Jun; Zou, Xiang; Chen, Liang; Ying, Liang-Jun; Wu, Ke; Yang, Jun-Qing; Sun, Wen-Juan; Deng, Zhong-Liang; He, Bai-Cheng

    2014-12-01

    Mouse embryonic fibroblasts (MEFs) are multi-potent progenitor cells (MPCs), can differentiate into different lineages, such as osteogenic, and adipogenic. PTEN, a tumor suppressor, may be involved in regulating bone development through interacting with COX-2. BMP9, the most potent osteogenic BMPs, can up-regulate COX-2 in MPCs. Whether PTEN is involved in BMP9 induced osteogenic differentiation in MPCs remains unknown. The goal of this investigation is to identify the effect of PTEN on BMP9-induced osteogenic differentiation in MPCs and dissect the possible mechanism underlay this. We found that BMP9 down-regulates PTEN, and PTEN inhibitor (VO) effectively increases different osteogenic markers induced by BMP9 in MEFs. Exogenous expression of PTEN inhibits BMP9 induced ectopic bone formation apparently. Mechanistically, we found that VO can enhance BMP9 induced BMPs/Smads signaling prominently without no substantial effects on cell cycle. Further analysis indicates that VO can promote BMP9-induced expression of COX-2 in MEFs, which can be eliminated by PI3K inhibitor. Additionally, COX-2 knockdown abolishes the effect of VO on BMP9-induced ALP activities in MEFs. Our findings suggest that PTEN plays an important role in regulating BMP9 induced osteogenic differentiation in MPCs, which may be mediated by PTEN/PI3K/Akt signaling to modulate the expression of COX-2.

  5. EB 1089, a novel vitamin D analog with strong antiproliferative and differentiation-inducing effects on target cells.

    PubMed

    Hansen, C M; Mäenpää, P H

    1997-12-01

    The physiologically active form of vitamin D, 1alpha,25-dihydroxyvitamin D3, plays an important role not only in the establishment and maintenance of calcium metabolism, but also in regulating cell growth and differentiation. As the clinical usefulness of 1alpha,25-dihydroxyvitamin D3 is limited by its tendency to cause hypercalcemia, new analogs with a better therapeutic profile have been synthesized. One of these new synthetic vitamin D analogs is EB 1089, which is characterized by an altered side chain structure featuring 26,27-dimethyl groups and two double bonds. This analog has been shown to be more potent than 1,25-dihydroxyvitamin D3 in inhibiting proliferation, stimulating differentiation, and inducing apoptosis in a number of different cell types, including cancer cells. Despite being more potent than 1alpha,25-dihydroxyvitamin D3 with respect to its cell regulatory effects, EB 1089 displays weaker calcemic side-effects. These characteristics make EB 1089 a potentially useful compound for the treatment of a diversity of clinical disorders, including cancer and metabolic bone diseases. A promising phase I study with EB 1089 in patients with advanced breast and colon cancer has already been carried out, and more clinical trials evaluating the clinical effectiveness of EB 1089 in other types of cancer are in progress.

  6. Isoliquiritigenin-induced effects on Nrf2 mediated antioxidant defence in the HL-60 cell monocytic differentiation.

    PubMed

    Chen, Hongmei; Zhang, Bo; Yuan, Xuan; Yao, Ying; Zhao, Hong; Sun, Xiling; Zheng, Quisheng

    2013-11-01

    To evaluate the role of redox homeostasis in differentiation in human promyelocytic leukemia cells (HL-60) induced by isoliquiritigenin (ISL) through modulation of the nuclear erythroid-related factor 2/antioxidant responsive element (Nrf2/ARE) pathway. Morphological changes, cell surface markers CD11b/CD14, and nitroblue tetrazolium (NBT)-reducing ability were used to determine the differentiation of HL-60, and 2,7-dichlorofluorescein was used to detect the level of intracellular reactive oxygen species (ROS). Thiobarbituric acid test was utilised to determine the levels of malondialdehyde production in ISL-treated HL-60. The study determines and presents the redox state of the ratio of reduced/oxidised glutathione as a consequence of progression from differentiation in HL-60. Expression levels of the Nrf2/ARE downstream target genes were determined by quantitative polymerase chain reaction. Nicotinamide adenine dinucleotide phosphate-oxidase (NADPH oxidase) inhibitors, apocynin (APO), and diphenyleneiodonium (DPI) were used for the preliminary study to determine the potential downstream targets regulated by NADPH oxidase in ISL-induced HL-60 differentiation. The data showed a strong dose-response relationship between ISL exposure and the characteristics of HL-60 differentiation, namely, morphology changes, NBT reductive activities, and expression levels of surface antigens CD11b/CD14. Intercellular redox homeostasis changes toward oxidation during drug exposure are necessary to support ISL-induced differentiation. The unique expression levels of the Nrf2/ARE downstream target genes in the differentiation of HL-60 recorded a statistically significant and dose-dependent increase (P < 0.05), which were suppressed by NADPH oxidase inhibitor, APO, and DPI. ISL as a differentiation-inducing agent with mechanisms involved in the Nrf2/ARE pathway to modulate intercellular redox homeostasis, and thus, facilitate differentiation.

  7. Effect of anthocyanidins on myogenic differentiation in induced and non-induced primary myoblasts from rainbow trout (Oncorhynchus mykiss).

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted to test whether an anthocyanidin mixture (peonidin, cyanidin and pelargonidin chloride) modulates myogenesis in both induced and non-induced myogenic cells from juvenile rainbow trout (Oncorhynchus mykiss). We evaluated three different anthocyanidin concentrations (1X, 2.5X and...

  8. Differential effects of gram-positive and gram-negative bacterial products on morphine induced inhibition of phagocytosis

    PubMed Central

    Jana, Ninkovic; Vidhu, Anand; Raini, Dutta; Zhang, Li; Saluja, Anuj; Meng, Jingjing; Lisa, Koodie; Santanu, Banerjee; Sabita, Roy

    2016-01-01

    Opioid drug abusers have a greater susceptibility to gram positive (Gram (+)) bacterial infections. However, the mechanism underlying opioid modulation of Gram (+) versus Gram (−) bacterial clearance has not been investigated. In this study, we show that opioid treatment resulted in reduced phagocytosis of Gram (+), when compared to Gram (−) bacteria. We further established that LPS priming of chronic morphine treated macrophages leads to potentiated phagocytosis and killing of both Gram (+) and Gram (−) bacteria in a P-38 MAP kinase dependent signaling pathway. In contrast, LTA priming lead to inhibition of both phagocytosis and bacterial killing. This study demonstrates for the first time the differential effects of TLR4 and TLR2 agonists on morphine induced inhibition of phagocytosis. Our results suggest that the incidence and severity of secondary infections with Gram (+) bacteria would be higher in opioid abusers. PMID:26891899

  9. Differential effects of gram-positive and gram-negative bacterial products on morphine induced inhibition of phagocytosis.

    PubMed

    Ninkovic, Jana; Jana, Ninkovic; Anand, Vidhu; Vidhu, Anand; Dutta, Raini; Raini, Dutta; Zhang, Li; Saluja, Anuj; Meng, Jingjing; Koodie, Lisa; Lisa, Koodie; Banerjee, Santanu; Santanu, Banerjee; Roy, Sabita; Sabita, Roy

    2016-02-19

    Opioid drug abusers have a greater susceptibility to gram positive (Gram (+)) bacterial infections. However, the mechanism underlying opioid modulation of Gram (+) versus Gram (-) bacterial clearance has not been investigated. In this study, we show that opioid treatment resulted in reduced phagocytosis of Gram (+), when compared to Gram (-) bacteria. We further established that LPS priming of chronic morphine treated macrophages leads to potentiated phagocytosis and killing of both Gram (+) and Gram (-) bacteria in a P-38 MAP kinase dependent signaling pathway. In contrast, LTA priming lead to inhibition of both phagocytosis and bacterial killing. This study demonstrates for the first time the differential effects of TLR4 and TLR2 agonists on morphine induced inhibition of phagocytosis. Our results suggest that the incidence and severity of secondary infections with Gram (+) bacteria would be higher in opioid abusers.

  10. MicroRNA-1 effectively induces differentiation of myocardial cells from mouse bone marrow mesenchymal stem cells.

    PubMed

    Zhao, Xiao-Ling; Yang, Bo; Ma, Li-Na; Dong, Yan-Hua

    2016-11-01

    In this research, bone marrow mesenchymal stem cells (BMSCs) were isolated from mouse, and induced differentiation into myocardial cells in vitro after overexpression of miR-1a. The results showed that the BMSCs could induce differentiation into myocardial cells under the special condition medium, but when the miR-1a was over-expressed in BMSCs, the differentiation efficiency and induction time of myocardial cells from BMSCs could be promoted. This reason was demonstrated that Delta-like 1 (Dll-1) was a transcriptional repressor of myocardium gene expression during myocardium differentiation, miR-1a reduced Dll-1 levels, leading to the accumulation of myocardium gene mRNA and a dramatic increase in myocardium gene protein.

  11. Troglitazone induces differentiation in Trypanosoma brucei

    SciTech Connect

    Denninger, Viola; Figarella, Katherine; Schoenfeld, Caroline; Brems, Stefanie; Busold, Christian; Lang, Florian; Hoheisel, Joerg; Duszenko, Michael . E-mail: michael.duszenko@uni-tuebingen.de

    2007-05-15

    Trypanosoma brucei, a protozoan parasite causing sleeping sickness, is transmitted by the tsetse fly and undergoes a complex lifecycle including several defined stages within the insect vector and its mammalian host. In the latter, differentiation from the long slender to the short stumpy form is induced by a yet unknown factor of trypanosomal origin. Here we describe that some thiazolidinediones are also able to induce differentiation. In higher eukaryotes, thiazolidinediones are involved in metabolism and differentiation processes mainly by binding to the intracellular receptor peroxisome proliferator activated receptor {gamma}. Our studies focus on the effects of troglitazone on bloodstream form trypanosomes. Differentiation was monitored using mitochondrial markers (membrane potential, succinate dehydrogenase activity, inhibition of oxygen uptake by KCN, amount of cytochrome transcripts), morphological changes (Transmission EM and light microscopy), and transformation experiments (loss of the Variant Surface Glycoprotein coat and increase of dihydroliponamide dehydrogenase activity). To further investigate the mechanisms responsible for these changes, microarray analyses were performed, showing an upregulation of expression site associated gene 8 (ESAG8), a potential differentiation regulator.

  12. Collective effect of personal behavior induced preventive measures and differential rate of transmission on spread of epidemics

    NASA Astrophysics Data System (ADS)

    Sagar, Vikram; Zhao, Yi

    2017-02-01

    In the present work, the effect of personal behavior induced preventive measures is studied on the spread of epidemics over scale free networks that are characterized by the differential rate of disease transmission. The role of personal behavior induced preventive measures is parameterized in terms of variable λ, which modulates the number of concurrent contacts a node makes with the fraction of its neighboring nodes. The dynamics of the disease is described by a non-linear Susceptible Infected Susceptible model based upon the discrete time Markov Chain method. The network mean field approach is generalized to account for the effect of non-linear coupling between the aforementioned factors on the collective dynamics of nodes. The upper bound estimates of the disease outbreak threshold obtained from the mean field theory are found to be in good agreement with the corresponding non-linear stochastic model. From the results of parametric study, it is shown that the epidemic size has inverse dependence on the preventive measures (λ). It has also been shown that the increase in the average degree of the nodes lowers the time of spread and enhances the size of epidemics.

  13. [Activation of endoplasmic reticulum stress and its effect on osteogenic differentiation induced by micropit/nanotube topography].

    PubMed

    Shi, M Q; Song, W; Han, T X; Chang, B; Zhang, Y M

    2017-02-09

    Objective: To explore the activation of endoplasmic reticulum stress (ERS) in bone marrow mesenchymal stem cell (BMMSC) and its effect on osteogenic differentiation induced by micropit/nanotube topography (MNT), so as to provide guidance for the topography design of biomaterials. Methods: Four sample groups were fabricated: polishing control group (polished titanium, PT, no treatment), thapsigargin treatment (TG, 0.1 μmol/L TG treated for 9 h), MNT5 and MNT20 (anodized at 5 V and 20 V after acid etching). Scanning electron microscope (SEM) was used to observe the topography of Ti samples. The alkaline phosphatase (ALP) production, collagen secretion and extracellular matrix (ECM) mineralization of BMMSC (osteogenic induced for 7, 14 and 21 d) on Ti samples were detected to evaluate the osteogenic differentiation. After 12 h incubation, the shape and size of ER was examined using a transmission electron microscope (TEM), and ERS-related genes including immunoglobulin heavy chain binding protein (BiP), protein kinase RNA-like endoplasmic reticulum kinase (PERK) and activating transcription factor 4 (ATF4) were detected by quantitative real-time PCR (qRT-PCR). Results: After 7, 14 and 21 d of induction, the ALP production, collagen secretion and ECM mineralization in TG and MNT20 all significantly increased compared to PT (P<0.05). The cells grown on TG, MNT5 and MNT20 surfaces displayed gross distortions of the ER. Compared to PT, BiP, PERK, ATF4 mRNA expression in TG was respectively 1.87±0.10, 2.24±0.35, 1.85±0.14; BiP, ATF4 mRNA expression in MNT5 were respectively 1.27±0.09, 1.25±0.04; BiP, PERK, ATF4 mRNA expression in MNT20 were respectively 1.44±0.09, 2.40±0.60, 1.48±0.05 (P<0.05). Conclusions: MNT triggered different degree of ERS, and the activated ERS may promote MNT-induced osteogenic differentiation.

  14. HOXC9-Induced Differentiation in Neuroblastoma Development

    DTIC Science & Technology

    2013-10-01

    Award Number: W81XWH-12-1-0613 TITLE: HOXC9-Induced Differentiation in Neuroblastoma Development...3. DATES COVERED (From - To) 09/30/2012 – 09/29/2013 4. TITLE AND SUBTITLE HOXC9-­‐Induced  Differentiation  in   Neuroblastoma ...determining the differentiation states of neuroblastoma tumors, with higher levels of HOXC9 promoting differentiation. At the cellular level, HOXC9

  15. Therapeutic effect of erythroid differentiation regulator 1 (Erdr1) on collagen-induced arthritis in DBA/1J mouse

    PubMed Central

    Kim, Kyung Eun; Kim, Sungryung; Park, Sunyoung; Houh, Younkyung; Yang, Yoolhee; Park, Seung Beom; Kim, Sangyoon; Kim, Daejin; Hur, Dae Young; Kim, Seonghan

    2016-01-01

    Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease, and multiple inflammatory cytokines are involved in RA pathogenesis. Interleukin (IL)-18, in particular, has a significant positive correlation with RA. In this study, we investigated the effect of erythroid differentiation regulator 1 (Erdr1), which is negatively regulated by IL-18, in an animal model of inflammatory arthritis, collagen-induced arthritis (CIA) in DBA/1J mice. Treatment of mice with recombinant (r)Erdr1 significantly suppressed the severity of arthritis, histologic features of arthritic tissue, and serum levels of anti-collagen autoantibodies (IgG, IgG1, IgG2a and IgM) in CIA. In addition, IL-18 expression was reduced in the affected synovium of rErdr1-treated mice. Interestingly, Erdr1 treatment suppressed migration in contrast to the pro-migratory effect of IL-18, indicating the therapeutic effects of Erdr1 on CIA through inhibiting synovial fibroblast migration. In addition, Erdr1 inhibited activation of ERK1/2, a key signaling pathway in migration of various cell types. Taken together, these data show that rErdr1 exerts therapeutic effects on RA by inhibiting synovial fibroblast migration, suggesting that rErdr1 treatment might be an effective therapeutic approach for RA. PMID:27823968

  16. Aldose reductase induced by hyperosmotic stress mediates cardiomyocyte apoptosis: differential effects of sorbitol and mannitol.

    PubMed

    Galvez, Anita S; Ulloa, Juan Alberto; Chiong, Mario; Criollo, Alfredo; Eisner, Verónica; Barros, Luis Felipe; Lavandero, Sergio

    2003-10-03

    Cells adapt to hyperosmotic conditions by several mechanisms, including accumulation of sorbitol via induction of the polyol pathway. Failure to adapt to osmotic stress can result in apoptotic cell death. In the present study, we assessed the role of aldose reductase, the key enzyme of the polyol pathway, in cardiac myocyte apoptosis. Hyperosmotic stress, elicited by exposure of cultured rat cardiac myocytes to the nonpermeant solutes sorbitol and mannitol, caused identical cell shrinkage and adaptive hexose uptake stimulation. In contrast, only sorbitol induced the polyol pathway and triggered stress pathways as well as apoptosis-related signaling events. Sorbitol resulted in activation of the extracellular signal-regulated kinase (ERK), p54 c-Jun N-terminal kinase (JNK), and protein kinase B. Furthermore, sorbitol treatment resulting in induction and activation of aldose reductase, decreased expression of the antiapoptotic protein Bcl-xL, increased DNA fragmentation, and glutathione depletion. Apoptosis was attenuated by aldose reductase inhibition with zopolrestat and also by glutathione replenishment with N-acetylcysteine. In conclusion, our data show that hypertonic shrinkage of cardiac myocytes alone is not sufficient to induce cardiac myocyte apoptosis. Hyperosmolarity-induced cell death is sensitive to the nature of the osmolyte and requires induction of aldose reductase as well as a decrease in intracellular glutathione levels.

  17. Cisplatin Induces Differentiation of Breast Cancer Cells

    PubMed Central

    Prabhakaran, Praseetha; Hassiotou, Foteini; Blancafort, Pilar; Filgueira, Luis

    2013-01-01

    Breast tumors are heterogeneous including cells with stem cell properties and more differentiated cells. This heterogeneity is reflected into the molecular breast cancer subtypes. Breast cancer stem cells are resistant to chemotherapy, thus recent efforts are focusing on identifying treatments that shift them toward a more differentiated phenotype, making them more susceptible to chemotherapy. We examined whether the drug cisplatin induces differentiation in breast cancer cell lines that represent different breast cancer subtypes. We used three cell lines representing triple-negative breast cancers, BT-549 and MDA-MB-231 (claudin-low), and MDA-MB-468 (basal-like), along with estrogen and progesterone receptor positive MCF-7 cells (luminal). Cisplatin was applied at 2.5, 5, 10, and 20 μM, and cell viability and proliferation were measured using MTS and BrdU assays, respectively. The effect of cisplatin on the cellular hierarchy was examined by flow cytometry, immunofluorescence and qRT-PCR. Cisplatin treatment of 10 and 20 μM reduced cell viability by 36–51% and proliferation capacity by 36–67%. Treatment with cisplatin resulted in 12–67% down-regulation of stem cell markers (CD49f, SSEA4) and 10–130% up-regulation of differentiation markers (CK18, SMA, β-tubulin). At the mRNA level, CD49f was down-regulated whilst β-tubulin was up-regulated in the claudin-low cell lines. SSEA4 protein expression decreased upon cisplatin treatment, but SSEA4 mRNA expression increased indicating a differential regulation of cisplatin at the post-transcriptional level. It is concluded that cisplatin reduces breast cancer cell survival and induces differentiation of stem/progenitor cell subpopulations within breast cancer cell lines. These effects indicate the potential of this drug to target specific chemotherapy-resistant cells within a tumor. PMID:23761858

  18. Proteomic responses reveal the differential effects induced by cadmium in mussels Mytilus galloprovincialis at early life stages.

    PubMed

    Xu, Lanlan; Peng, Xiao; Yu, Deliang; Ji, Chenglong; Zhao, Jianmin; Wu, Huifeng

    2016-08-01

    Cadmium (Cd) has become an important metal contaminant and posed severe risk on the organisms in the coastal environments of the Bohai Sea. Marine mussel Mytilus galloprovincialis is widely distributed along the Bohai coast and consumed as seafood by local residents. Evidences indicate that the early stages of marine organisms are more sensitive to metal contaminants. In this study, we applied two-dimensional electrophoresis-based proteomics to characterize the biological effects of Cd (50 μg L(-1)) in the early life stages (D-shape larval and juvenile) of mussels. The different proteomic responses demonstrated the differential responsive mechanisms to Cd exposure in these two early life stages of mussels. In details, results indicated that Cd mainly induced immune and oxidative stresses in both D-shape larval and juvenile mussels via different pathways. In addition, the significant up-regulation of triosephosphate isomerase and metallothionein confirmed the enhanced energy demand and mobilized detoxification mechanism in D-shape larval mussels exposed to Cd. In juvenile mussels, Cd exposure also induced clear apoptosis. Overall, this work suggests that Cd is a potential immune toxicant to mussel M. galloprovincialis at early life stages.

  19. Effect of angiotensin II on proliferation and differentiation of mouse induced pluripotent stem cells into mesodermal progenitor cells

    SciTech Connect

    Ishizuka, Toshiaki; Goshima, Hazuki; Ozawa, Ayako; Watanabe, Yasuhiro

    2012-03-30

    Highlights: Black-Right-Pointing-Pointer Treatment with angiotensin II enhanced LIF-induced DNA synthesis of mouse iPS cells. Black-Right-Pointing-Pointer Angiotensin II may enhance the DNA synthesis via induction of superoxide. Black-Right-Pointing-Pointer Treatment with angiotensin II significantly increased JAK/STAT3 phosphorylation. Black-Right-Pointing-Pointer Angiotensin II enhanced differentiation into mesodermal progenitor cells. Black-Right-Pointing-Pointer Angiotensin II may enhance the differentiation via activation of p38 MAPK. -- Abstract: Previous studies suggest that angiotensin receptor stimulation may enhance not only proliferation but also differentiation of undifferentiated stem/progenitor cells. Therefore, in the present study, we determined the involvement of the angiotensin receptor in the proliferation and differentiation of mouse induced pluripotent stem (iPS) cells. Stimulation with angiotensin II (Ang II) significantly increased DNA synthesis in mouse iPS cells cultured in a medium with leukemia inhibitory factor (LIF). Pretreatment of the cells with either candesartan (a selective Ang II type 1 receptor [AT{sub 1}R] antagonist) or Tempol (a cell-permeable superoxide scavenger) significantly inhibited Ang II-induced DNA synthesis. Treatment with Ang II significantly increased JAK/STAT3 phosphorylation. Pretreatment with candesartan significantly inhibited Ang II- induced JAK/STAT3 phosphorylation. In contrast, induction of mouse iPS cell differentiation into Flk-1-positive mesodermal progenitor cells was performed in type IV collagen (Col IV)- coated dishes in a differentiation medium without LIF. When Col IV-exposed iPS cells were treated with Ang II for 5 days, the expression of Flk-1 was significantly increased compared with that in the cells treated with the vehicle alone. Pretreatment of the cells with both candesartan and SB203580 (a p38 MAPK inhibitor) significantly inhibited the Ang II- induced increase in Flk-1 expression

  20. Thermospermine suppresses auxin-inducible xylem differentiation in Arabidopsis thaliana.

    PubMed

    Yoshimoto, Kaori; Noutoshi, Yoshiteru; Hayashi, Ken-ichiro; Shirasu, Ken; Takahashi, Taku; Motose, Hiroyasu

    2012-08-01

    Thermospermine, a structural isomer of spermine, is synthesized by a thermospermine synthase designated ACAULIS5 (ACL5). Thermospermine-deficient acl5 mutant of Arabidopsis thaliana shows severe dwarfism and excessive xylem differentiation. By screening for compounds that affect xylem differentiation in the acl5 mutant, we identified auxin analogs that remarkably enhanced xylem vessel differentiation in the acl5 mutant but not in the wild type. The xylem-inducing effect of auxin analogs was clearly suppressed by thermospermine, indicating that auxin-inducible xylem differentiation is normally limited by thermospermine. Here, we further characterized xylem-inducing effect of auxin analogs in various organs. Auxin analogs promoted protoxylem differentiation in roots and cotyledons in the acl5 mutant. Our results indicate that the opposite action between thermospermine and auxin in xylem differentiation is common in different organs and also suggest that thermospermine might be required for the suppression of protoxylem differentiation.

  1. Lasting Differential Effects on Plasticity Induced by Prenatal Stress in Dorsal and Ventral Hippocampus

    PubMed Central

    Grigoryan, Gayane; Segal, Menahem

    2016-01-01

    Early life adversaries have a profound impact on the developing brain structure and functions that persist long after the original traumatic experience has vanished. One of the extensively studied brain structures in relation to early life stress has been the hippocampus because of its unique association with cognitive processes of the brain. While the entire hippocampus shares the same intrinsic organization, it assumes different functions in its dorsal and ventral sectors (DH and VH, resp.), based on different connectivity with other brain structures. In the present review, we summarize the differences between DH and VH and discuss functional and structural effects of prenatal stress in the two sectors, with the realization that much is yet to be explored in understanding the opposite reactivity of the DH and VH to stressful stimulation. PMID:26881096

  2. Sevoflurane-induced isoelectric EEG and burst suppression: differential and antagonistic effect of added nitrous oxide.

    PubMed

    Niu, B; Xiao, J Y; Fang, Y; Zhou, B Y; Li, J; Cao, F; Tian, Y K; Mei, W

    2017-03-08

    The objective of this study was to investigate whether nitrous oxide influenced the ED50 of sevoflurane for induction of isoelectric electroencephalogram (ED50isoelectric ) differently from its influence on the ED50 of sevoflurane for electroencephalogram burst suppression (ED50burst ). In a prospective, randomised, double-blind, parallel group, up-down sequential allocation study, 77 ASA physical status 1 and 2 patients received sevoflurane induction and, after tracheal intubation, were randomly allocated to receive sevoflurane with either 40% oxygen in air (control group) or 60% nitrous oxide in oxygen mixture (nitrous group). The ED50isoelectric in the two groups was determined using Dixon's up and down method, starting at 2.5% with 0.2% step size of end-tidal sevoflurane. The electroencephalogram was considered as isoelectric when a burst suppression ratio of 100% lasted > 1 min. The subsequent concentrations of sevoflurane administered were determined by the presence or absence of isoelectric electroencephalogram in the previous patient in the same group. The ED50isoelectric in the nitrous group 4.08 (95%CI, 3.95-4.38)% was significantly higher than that in the control group 3.68 (95%CI, 3.50-3.78)% (p < 0.0001). The values for ED50burst were 3.05 (95%CI, 2.66-3.90)% and 3.02 (95%CI, 3.00-3.05)% in nitrous group and control group, respectively (p = 0.52). The addition of 60% nitrous oxide increases ED50isoelectric , but not the ED50burst of sevoflurane. Neither result indicates an additive effect of anaesthetic agents, as might be expected, and possible reasons for this are discussed.

  3. Combined effects of flow-induced shear stress and electromagnetic field on neural differentiation of mesenchymal stem cells.

    PubMed

    Mascotte-Cruz, Juan Uriel; Ríos, Amelia; Escalante, Bruno

    2016-01-01

    Differentiation of bone marrow-derived mesenchymal stem cells (MSCs) into neural phenotype has been induced by either flow-induced shear stress (FSS) or electromagnetic fields (EMF). However, procedures are still expensive and time consuming. In the present work, induction for 1 h with the combination of both forces showed the presence of the neural precursor nestin as early as 9 h in culture after treatment and this result lasted for the following 6 d. In conclusion, the use of a combination of FSS and EMF for a short-time renders in neurite-like cells, although further investigation is required to analyze cell functionality.

  4. Dose dependent effect of C-type natriuretic peptide signaling in glycosaminoglycan synthesis during TGF-β1 induced chondrogenic differentiation of mesenchymal stem cells.

    PubMed

    Tezcan, Berna; Serter, Sema; Kiter, Esat; Tufan, A Cevik

    2010-10-01

    Recent investigations credited important roles to C-type natriuretic peptide (CNP) signaling during chondrogenesis. This study investigated the putative role of CNP in transforming growth factor (TGF)-β1 induced in vitro chondrogenic differentiation of mesenchymal stem cells (MSCs) in pellet culture. MSCs were derived from human trabecular bone and were characterized on the basis of their cell surface antigens and adipogenic, osteogenic, and chondrogenic differentiation potential. TGF-β1 induced chondrogenic differentiation and glycosaminoglycan (GAG) synthesis was analyzed on the basis of basic histology, collagen type II, Sox 9 and aggrecan expressions, and Alcian blue staining. Results revealed that human trabecular bone-derived MSCs express CNP and NPR-B analyzed on the basis of RT-PCR and immunohistochemistry. In pellet cultures of MSCs TGF-β1 successfully induced chondrogenic differentiation and GAG synthesis. RT-PCR analyses of both CNP and NPR-B during this process revealed an activation of this signaling pathway in response to TGF-β1. Similar cultures induced with TGF-β1 and treated with different doses of CNP showed that CNP supplementation at 10(-8) and 10(-7) M concentrations significantly increased GAG synthesis in a dose dependent manner, whereas at 10(-6) M concentration this stimulatory effect was diminished. In conclusion, CNP/NPR-B signaling pathway is activated during TGF-β1 induced chondrogenic differentiation of human trabecular bone-derived MSCs and may strongly be involved in GAG synthesis during this process. This effect is likely to be a dose-dependent effect.

  5. Induced Pluripotent Stem Cells Can Effectively Differentiate into Multiple Functional Lymphocyte Lineages In Vivo with Negligible Bias.

    PubMed

    Lan, Tianshu; Wang, Libin; Xu, Lin; Jin, Ning; Yan, Guoliang; Xia, Junjie; Wang, Hailong; Zhuang, Guohong; Gao, Chang; Meng, Luxi; Du, Feifei; Zhou, Qi; Qi, Zhongquan

    2016-03-15

    Lymphohematopoietic stem cells (L-HSCs) generated from self-somatic cell-derived induced pluripotent stem cells (iPSCs) are a potential source of cells for the treatment of hematological disorders. However, the generation of truly functional L-HSCs from iPSCs has yet to be achieved. Thus, whether iPSCs have the inherent potential to generate a normal differentiated phenotype and functional population of multiple lineages of terminally differentiated lymphocytes needs to be assessed. Here, we used tetraploid embryo complementation to provide a normal environment for the differentiation of hematopoietic cells from iPSCs and embryonic stem cells (ESCs). We then evaluated the characteristics, populations, and functions of lymphocytes derived from iPSCs, ESCs, and naïve isogenic C57BL/6 mice. The results showed that iPSC-derived lymphocytes (iPSLs) expressed normal levels of major histocompatibility complex-I (MHC-I) and exhibited a fully pluripotent capacity to differentiate into CD4(+) T, CD8(+) T, regulatory T, B, and natural killer cells. Following in vitro stimulation with either concanavalin A or an alloantigen, iPSLs exhibited the same capacities for proliferation and cytokine secretion as ESC-derived or isogenic lymphocytes. Furthermore, iPSC-derived bone marrow cells could differentiate into multiple lymphocyte lineages that reconstituted the lymphocyte population in syngeneic lethally irradiated recipient animals. Our results demonstrated that iPSCs have the inherent potential to differentiate into multiple lineages of functional lymphocytes without bias, and further support the practical application of iPSC-based treatments to hematological disorders.

  6. Dual-Blocking of PI3K and mTOR Improves Chemotherapeutic Effects on SW620 Human Colorectal Cancer Stem Cells by Inducing Differentiation

    PubMed Central

    Kim, Buyun

    2016-01-01

    Cancer stem cells (CSCs) have tumor initiation, self-renewal, metastasis and chemo-resistance properties in various tumors including colorectal cancer. Targeting of CSCs may be essential to prevent relapse of tumors after chemotherapy. Phosphatidylinositol-3-kinase (PI3K) and mammalian target of rapamycin (mTOR) signals are central regulators of cell growth, proliferation, differentiation, and apoptosis. These pathways are related to colorectal tumorigenesis. This study focused on PI3K and mTOR pathways by inhibition which initiate differentiation of SW620 derived CSCs and investigated its effect on tumor progression. By using rapamycin, LY294002, and NVP-BEZ235, respectively, PI3K and mTOR signals were blocked independently or dually in colorectal CSCs. Colorectal CSCs gained their differentiation property and lost their stemness properties most significantly in dual-blocked CSCs. After treated with anti-cancer drug (paclitaxel) on the differentiated CSCs cell viability, self-renewal ability and differentiation status were analyzed. As a result dual-blocking group has most enhanced sensitivity for anti-cancer drug. Xenograft tumorigenesis assay by using immunodeficiency mice also shows that dual-inhibited group more effectively increased drug sensitivity and suppressed tumor growth compared to single-inhibited groups. Therefore it could have potent anti-cancer effects that dual-blocking of PI3K and mTOR induces differentiation and improves chemotherapeutic effects on SW620 human colorectal CSCs. PMID:26955235

  7. [Effect of APN/CD13 on bestatin enhancing all-trans-retinoic acid-inducing differentiation in NB4 cells].

    PubMed

    Qian, Xi-Jun; Lin, Mao-Fang

    2011-10-01

    This study was purposed to investigate the effect of aminopeptidase N/CD13 on bestatin enhancing all-trans-retinoic acid (ATRA)-inducing differentiation in NB4 cells. The nitroblue-tetrazolium (NBT) reduction assay was performed to determine the differentiation of NB4 cells, MR2 cells and primary APL blasts. The expression of P38 MAPK protein and the phosphorylation of P38 MAPK protein in NB4, MR2 and K562 cells were detected by Western blot. The results showed that pre-incubation with 5 µg/ml WM-15 blocked the enhancement effect of bestatin on differentiation of NB4 cells induced by ATRA. 5 µg/ml CD13 antibody WM-15 partly blocked the inhibition of bestatin on the phosphorylation of P38 MAPK in NB4 cells. 100 µg/ml bestatin inhibited the phosphorylation of P38 MAPK in NB4 cells and MR2 cells in a time-dependent manner. 100 µg/ml bestatin had no effect on the phosphorylation of P38 MAPK in K562 cells with low level of CD13. Bestatin could not restore the sensitivity to ATRA in ATRA-resistant primary APL blasts and MR2 cells. It is concluded that aminopeptidase N/CD13 inhibitor bestatin may enhance the differentiation-inducing activity of ATRA through inhibiting the phosphorylation of P38 MAPK in NB4 cells mediated by the cell surface APN/CD13.

  8. The Effect of Bone Marrow Mesenchymal Stem Cells on Vitamin D3 Induced Monocytic Differentiation of U937 Cells

    PubMed Central

    Molaeipour, Zahra; Shamsasanjan, Karim; Movassaghpour, Ali Akbari; Akbarzadehlaleh, Parvin; Sabaghi, Fatemeh; Saleh, Mahshid

    2016-01-01

    Purpose: Mesenchymal stem cells (MSCs) are key components of the hematopoietic stem cells (HSCs) niche. They control the process of hematopoiesis by secreting regulatory cytokines, growth factors and expression of important cell adhesion molecules for cell-tocell interactions. In this research, we have investigated the effect of bone marrow derived MSCs on monocytic differentiation of U937 cells line. Methods: U937 cells were cultured in both direct co-culture with MSCs and MSCs conditioned medium (C.M) driven. This study used 1,25-dihydroxyvitamin D3(VitD3) as inductor of monocytic differentiation and U937 cells treated with VitD3 morphology was examined by Wright Giemsa staining. CD14 monocytic differentiation marker was measured by flow cytometry and monocytic gene expression was assessed by real time polymerase chain reaction (RT PCR). Results: The results of flow cytometric analysis showed that CD14 expression of U937 increased. The higher effect of MSCs co-culture on CD14 expression in U937 cells was observed, compared to the conditioned medium. Among ten monocytic related genes which were screened that was observed increase in 5 genes in which CXCR4 and CSF2RA showed significant increase. Conclusion: The results obtained show that MSCs have supportive effect on the monocytic differentiation of U937 cells. However, a distinct mechanism of that remains unclear. PMID:27123414

  9. Differential Response and Priming Dose Effect on the Proteome of Human Fibroblast and Stem Cells Induced by Exposure to Low Doses of Ionizing Radiation.

    PubMed

    Hauptmann, Monika; Haghdoost, Siamak; Gomolka, Maria; Sarioglu, Hakan; Ueffing, Marius; Dietz, Anne; Kulka, Ulrike; Unger, Kristian; Babini, Gabriele; Harms-Ringdahl, Mats; Ottolenghi, Andrea; Hornhardt, Sabine

    2016-03-01

    It has been suggested that a mechanistic understanding of the cellular responses to low dose and dose rate may be valuable in reducing some of the uncertainties involved in current risk estimates for cancer- and non-cancer-related radiation effects that are inherited in the linear no-threshold hypothesis. In this study, the effects of low-dose radiation on the proteome in both human fibroblasts and stem cells were investigated. Particular emphasis was placed on examining: 1. the dose-response relationships for the differential expression of proteins in the low-dose range (40-140 mGy) of low-linear energy transfer (LET) radiation; and 2. the effect on differential expression of proteins of a priming dose given prior to a challenge dose (adaptive response effects). These studies were performed on cultured human fibroblasts (VH10) and human adipose-derived stem cells (ADSC). The results from the VH10 cell experiments demonstrated that low-doses of low-LET radiation induced unique patterns of differentially expressed proteins for each dose investigated. In addition, a low priming radiation dose significantly changed the protein expression induced by the subsequent challenge exposure. In the ADSC the number of differentially expressed proteins was markedly less compared to VH10 cells, indicating that ADSC differ in their intrinsic response to low doses of radiation. The proteomic results are further discussed in terms of possible pathways influenced by low-dose irradiation.

  10. Retrovirus-induced osteopetrosis in mice. Effects of viral infection on osteogenic differentiation in skeletoblast cell cultures.

    PubMed Central

    Schmidt, J.; Casser-Bette, M.; Murray, A. B.; Luz, A.; Erfle, V.

    1987-01-01

    Newborn female strain NMRI mice were injected with a mouse retrovirus (OA MuLV) known to induce osteopetrosis. Primary skeletoblast cell cultures were established from humeri and calvaria of 3-day-old, 7-day-old, and 28-day-old animals. Infectious ecotropic MuLV was found in all humerus cultures from infected animals and in 7-day and 28-day calvaria cell cultures. Levels of alkaline phosphatase activity were markedly higher in cultures of calvaria and humeri from infected mice than in those from controls. In vitro infection of undifferentiated periosteal cells was followed by a decrease in cell growth and an increase in alkaline phosphatase activity. In contrast, differentiated osteoblast-like cells were barely susceptible to OA MuLV infection, and the virus did not influence their cell growth or differentiation. Electron-microscopic studies of skeletal tissue from infected old osteopetrotic mice showed virus particles associated with and budding from osteocytes and accumulated in devitalized osteocyte lacunae. The results indicate that progenitor cells of the osteoblastic lineage represent the target cells for OA MuLV in bone tissue, that virus infection induces an increase in osteoblastic activity, and that infected cells produce virus until full development of the disease. Images Figure 1 Figure 2 Figure 5 PMID:2827489

  11. Neuroprotective Effect of Puerarin on Glutamate-Induced Cytotoxicity in Differentiated Y-79 Cells via Inhibition of ROS Generation and Ca2+ Influx

    PubMed Central

    Wang, Ke; Zhu, Xue; Zhang, Kai; Wu, Zhifeng; Sun, Song; Zhou, Fanfan; Zhu, Ling

    2016-01-01

    Glutamate toxicity is estimated to be the key cause of photoreceptor degeneration in the pathogenesis of retinal degenerative diseases. Oxidative stress and Ca2+ influx induced by glutamate are responsible for the apoptosis process of photoreceptor degeneration. Puerarin, a primary component of Kudzu root, has been widely used in the clinical treatment of retinal degenerative diseases in China for decades; however, the detailed molecular mechanism underlying this effect remains unclear. In this study, the neuroprotective effect of puerarin against glutamate-induced cytotoxicity in the differentiated Y-79 cells was first investigated through cytotoxicity assay. Then the molecular mechanism of this effect regarding anti-oxidative stress and Ca2+ hemostasis was further explored with indirect immunofluorescence, flow cytometric analysis and western blot analysis. Our study showed that glutamate induced cell viability loss, excessive reactive oxygen species (ROS) generation, calcium overload and up-regulated cell apoptosis in differentiated Y-79 cells, which effect was significantly attenuated with the pre-treatment of puerarin in a dose-dependent manner. Furthermore, our data indicated that the neuroprotective effect of puerarin was potentially mediated through the inhibition of glutamate-induced activation of mitochondrial-dependent signaling pathway and calmodulin-dependent protein kinase II (CaMKII)-dependent apoptosis signal-regulating kinase 1(ASK-1)/c-Jun N-terminal kinase (JNK)/p38 signaling pathway. The present study supports the notion that puerarin may be a promising neuroprotective agent in the prevention of retinal degenerative diseases. PMID:27409614

  12. The Src family tyrosine kinases src and yes have differential effects on inflammation-induced apoptosis in human pulmonary microvascular endothelial cells.

    PubMed

    Nelin, Leif D; White, Hilary A; Jin, Yi; Trittmann, Jennifer K; Chen, Bernadette; Liu, Yusen

    2016-05-01

    Endothelial cells are essential for normal lung function: they sense and respond to circulating factors and hemodynamic alterations. In inflammatory lung diseases such as acute respiratory distress syndrome, endothelial cell apoptosis is an inciting event in pathogenesis and a prominent pathological feature. Endothelial cell apoptosis is mediated by circulating inflammatory factors, which bind to receptors on the cell surface, activating signal transduction pathways, leading to caspase-3-mediated apoptosis. We hypothesized that yes and src have differential effects on caspase-3 activation in human pulmonary microvascular endothelial cells (hPMVEC) due to differential downstream signaling effects. To test this hypothesis, hPMVEC were treated with siRNA against src (siRNAsrc), siRNA against yes (siRNAyes), or their respective scramble controls. After recovery, the hPMVEC were treated with cytomix (LPS, IL-1β, TNF-α, and IFN-γ). Treatment with cytomix induced activation of the extracellular signal-regulated kinase (ERK) pathway and caspase-3-mediated apoptosis. Treatment with siRNAsrc blunted cytomix-induced ERK activation and enhanced cleaved caspase-3 levels, while treatment with siRNAyes enhanced cytomix-induced ERK activation and attenuated levels of cleaved caspase-3. Inhibition of the ERK pathway using U0126 enhanced cytomix-induced caspase-3 activity. Treatment of hPMVEC with cytomix induced Akt activation, which was inhibited by siRNAsrc. Inhibition of the phosphatidylinositol 3-kinase/Akt pathway using LY294002 prevented cytomix-induced ERK activation and augmented cytomix-induced caspase-3 cleavage. Together, our data demonstrate that, in hPMVEC, yes activation blunts the ERK cascade in response to cytomix, resulting in greater apoptosis, while cytomix-induced src activation induces the phosphatidylinositol 3-kinase pathway, which leads to activation of Akt and ERK and attenuation of apoptosis.

  13. EB 1089, a novel vitamin D analogue, has strong antiproliferative and differentiation inducing effects on cancer cells.

    PubMed

    Mathiasen, I S; Colston, K W; Binderup, L

    1993-09-01

    EB 1089 is a novel vitamin D analogue which in vitro strongly inhibits the proliferation of U937 histiocytic lymphoma cells and MCF-7 breast cancer cells, with a potency of 50 to 100 times that of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3]. Studies of c-myc and c-fos expression in MCF-7 cells and of differentiation markers in U937 cells show that growth inhibition by EB 1089 is accompanied by induction of differentiation. The ability of EB 1089 to affect calcium metabolism in vivo in rats is decreased, compared to 1,25(OH)2D3. This low calcemic effect combined with the strong biological effect on cancer cells in vitro, makes EB 1089 an interesting candidate for treatment of cancer.

  14. Paracrine Effects of Adipose-Derived Stem Cells on Matrix Stiffness-Induced Cardiac Myofibroblast Differentiation via Angiotensin II Type 1 Receptor and Smad7.

    PubMed

    Yong, Kar Wey; Li, Yuhui; Liu, Fusheng; Bin Gao; Lu, Tian Jian; Wan Abas, Wan Abu Bakar; Wan Safwani, Wan Kamarul Zaman; Pingguan-Murphy, Belinda; Ma, Yufei; Xu, Feng; Huang, Guoyou

    2016-10-05

    Human mesenchymal stem cells (hMSCs) hold great promise in cardiac fibrosis therapy, due to their potential ability of inhibiting cardiac myofibroblast differentiation (a hallmark of cardiac fibrosis). However, the mechanism involved in their effects remains elusive. To explore this, it is necessary to develop an in vitro cardiac fibrosis model that incorporates pore size and native tissue-mimicking matrix stiffness, which may regulate cardiac myofibroblast differentiation. In the present study, collagen coated polyacrylamide hydrogel substrates were fabricated, in which the pore size was adjusted without altering the matrix stiffness. Stiffness is shown to regulate cardiac myofibroblast differentiation independently of pore size. Substrate at a stiffness of 30 kPa, which mimics the stiffness of native fibrotic cardiac tissue, was found to induce cardiac myofibroblast differentiation to create in vitro cardiac fibrosis model. Conditioned medium of hMSCs was applied to the model to determine its role and inhibitory mechanism on cardiac myofibroblast differentiation. It was found that hMSCs secrete hepatocyte growth factor (HGF) to inhibit cardiac myofibroblast differentiation via downregulation of angiotensin II type 1 receptor (AT1R) and upregulation of Smad7. These findings would aid in establishment of the therapeutic use of hMSCs in cardiac fibrosis therapy in future.

  15. Paracrine Effects of Adipose-Derived Stem Cells on Matrix Stiffness-Induced Cardiac Myofibroblast Differentiation via Angiotensin II Type 1 Receptor and Smad7

    PubMed Central

    Yong, Kar Wey; Li, Yuhui; Liu, Fusheng; Bin Gao; Lu, Tian Jian; Wan Abas, Wan Abu Bakar; Wan Safwani, Wan Kamarul Zaman; Pingguan-Murphy, Belinda; Ma, Yufei; Xu, Feng; Huang, Guoyou

    2016-01-01

    Human mesenchymal stem cells (hMSCs) hold great promise in cardiac fibrosis therapy, due to their potential ability of inhibiting cardiac myofibroblast differentiation (a hallmark of cardiac fibrosis). However, the mechanism involved in their effects remains elusive. To explore this, it is necessary to develop an in vitro cardiac fibrosis model that incorporates pore size and native tissue-mimicking matrix stiffness, which may regulate cardiac myofibroblast differentiation. In the present study, collagen coated polyacrylamide hydrogel substrates were fabricated, in which the pore size was adjusted without altering the matrix stiffness. Stiffness is shown to regulate cardiac myofibroblast differentiation independently of pore size. Substrate at a stiffness of 30 kPa, which mimics the stiffness of native fibrotic cardiac tissue, was found to induce cardiac myofibroblast differentiation to create in vitro cardiac fibrosis model. Conditioned medium of hMSCs was applied to the model to determine its role and inhibitory mechanism on cardiac myofibroblast differentiation. It was found that hMSCs secrete hepatocyte growth factor (HGF) to inhibit cardiac myofibroblast differentiation via downregulation of angiotensin II type 1 receptor (AT1R) and upregulation of Smad7. These findings would aid in establishment of the therapeutic use of hMSCs in cardiac fibrosis therapy in future. PMID:27703175

  16. Differential effects of p53 on bystander phenotypes induced by gamma ray and high LET heavy ion radiation.

    PubMed

    He, Mingyuan; Dong, Chen; Konishi, Teruaki; Tu, Wenzhi; Liu, Weili; Shiomi, Naoko; Kobayashi, Alisa; Uchihori, Yukio; Furusawa, Yoshiya; Hei, Tom K; Dang, Bingrong; Shao, Chunlin

    2014-04-01

    High LET particle irradiation has several potential advantages over γ-rays such as p53-independent response. The purpose of this work is to disclose the effect of p53 on the bystander effect induced by different LET irradiations and underlying mechanism. Lymphocyte cells of TK6 (wild type p53) and HMy2.CIR (mutated p53) were exposed to either low or high LET irradiation, then their mitochondrial dysfunction and ROS generation were detected. The micronuclei (MN) induction in HL-7702 hepatocytes co-cultured with irradiated lymphocytes was also measured. It was found that the mitochondrial dysfunction, p66(Shc) activation, and intracellular ROS were enhanced in TK6 but not in HMy2.CIR cells after γ-ray irradiation, but all of them were increased in both cell lines after carbon and iron irradiation. Consistently, the bystander effect of MN formation in HL-7702 cells was only triggered by γ-irradiated TK6 cells but not by γ-irradiated HMy2.CIR cells. But this bystander effect was induced by both lymphocyte cell lines after heavy ion irradiation. PFT-μ, an inhibitor of p53, only partly inhibited ROS generation and bystander effect induced by 30 keV/μm carbon-irradiated TK6 cells but failed to suppress the bystander effect induced by the TK6 cells irradiated with either 70 keV/μm carbon or 180 keV/μm iron. The mitochondrial inhibitors of rotenone and oligomycin eliminated heavy ion induced ROS generation in TK6 and HMy2.CIR cells and hence diminished the bystander effect on HL-7702 cells. These results clearly demonstrate that the bystander effect is p53-dependent for low LET irradiation, but it is p53-independent for high LET irradiation which may be because of p53-independent ROS generation due to mitochondrial dysfunction.

  17. Differential effects of p53 on bystander phenotypes induced by gamma ray and high LET heavy ion radiation

    NASA Astrophysics Data System (ADS)

    He, Mingyuan; Dong, Chen; Konishi, Teruaki; Tu, Wenzhi; Liu, Weili; Shiomi, Naoko; Kobayashi, Alisa; Uchihori, Yukio; Furusawa, Yoshiya; Hei, Tom K.; Dang, Bingrong; Shao, Chunlin

    2014-04-01

    High LET particle irradiation has several potential advantages over γ-rays such as p53-independent response. The purpose of this work is to disclose the effect of p53 on the bystander effect induced by different LET irradiations and underlying mechanism. Lymphocyte cells of TK6 (wild type p53) and HMy2.CIR (mutated p53) were exposed to either low or high LET irradiation, then their mitochondrial dysfunction and ROS generation were detected. The micronuclei (MN) induction in HL-7702 hepatocytes co-cultured with irradiated lymphocytes was also measured. It was found that the mitochondrial dysfunction, p66Shc activation, and intracellular ROS were enhanced in TK6 but not in HMy2.CIR cells after γ-ray irradiation, but all of them were increased in both cell lines after carbon and iron irradiation. Consistently, the bystander effect of MN formation in HL-7702 cells was only triggered by γ-irradiated TK6 cells but not by γ-irradiated HMy2.CIR cells. But this bystander effect was induced by both lymphocyte cell lines after heavy ion irradiation. PFT-μ, an inhibitor of p53, only partly inhibited ROS generation and bystander effect induced by 30 keV/μm carbon-irradiated TK6 cells but failed to suppress the bystander effect induced by the TK6 cells irradiated with either 70 keV/μm carbon or 180 keV/μm iron. The mitochondrial inhibitors of rotenone and oligomycin eliminated heavy ion induced ROS generation in TK6 and HMy2.CIR cells and hence diminished the bystander effect on HL-7702 cells. These results clearly demonstrate that the bystander effect is p53-dependent for low LET irradiation, but it is p53-independent for high LET irradiation which may be because of p53-independent ROS generation due to mitochondrial dysfunction.

  18. Diet-induced obesity has a differential effect on adipose tissue and macrophage inflammatory responses of young and old mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Obesity and aging are both associated with increased inflammation in adipose tissue. In this study, we investigated the effect of diet-induced obesity on inflammatory status in young and old mice. Young (2-mo) and old (19-mo) C57BL/6 mice were fed a low fat (10 percent LF) or high fat (60 percent, H...

  19. Differential effects of eugenol against hepatic inflammation and overall damage induced by ischemia/re-perfusion injury.

    PubMed

    Abd El Motteleb, Dalia M; Selim, Sally A; Mohamed, Ahmed M

    2014-01-01

    Liver injuries, liver tumor resection, and liver transplantation are known to be responsible for ischemia/reperfusion (I/R) injury that, in turn, gives rise to liver damage. This study was undertaken to investigate the possible protective effect of eugenol against the damage induced by I/R in rat livers as well as to explore possible mechanisms of action. Male rats were divided into four groups: sham-operated, I/R only, and two groups that received 10 or 100 mg eugenol/kg/day (Eug10 and Eug100, respectively) for 15 days by gavage and were then subjected to I/R, i.e. an ischemia induced for 45 min followed by re-perfusion for 6 h. The rats were euthanized and liver tissues and blood collected for examination. The results showed that I/R induced massive hepatic structural and functional damage. Eug10-treated rats had improvement in both liver function and structure, and inhibition of I/R-induced increases in serum myeloperoxidase (MPO), tumor necrosis factor (TNF)-α, as well as hepatic nuclear factor-κB (NF-κB) p65 and caspase-3 expression. Eug10 treatment also inhibited the degree of loss in reduced glutathione (GSH) and of rise in malondialdehyde (MDA) levels in liver tissues induced by I/R. In contrast, augmentation of liver damage induced by I/R was noted in Eug100-treated rats, with these hosts displaying significant increases in oxidant, inflammatory, and apoptotic markers relative to levels seen in I/R-only rats. The results of the present study provide the first evidence that a low dose of eugenol may protect the liver against I/R injury in part by decreasing levels of lipid peroxidation, down-regulating inflammatory mediators, and inhibiting apoptosis, and that a larger dose amplifies the liver injury via oxidant and inflammatory effects.

  20. Heat Stress and Hormetin-Induced Hormesis in Human Cells: Effects on Aging, Wound Healing, Angiogenesis, and Differentiation

    PubMed Central

    Rattan, Suresh I. S.; Fernandes, Ricardo A.; Demirovic, Dino; Dymek, Barbara; Lima, Cristovao F.

    2009-01-01

    Accumulation of molecular damage and increased molecular heterogeneity are hallmarks of cellular aging. Mild stress-induced hormesis can be an effective way for reducing the accumulation of molecular damage, and thus slowing down aging from within. We have shown that repeated mild heat stress (RMHS) has anti-aging effects on growth and various other cellular and biochemical characteristics of normal human skin fibroblasts and keratinocytes undergoing aging in vitro. RMHS given to human cells increased the basal levels of various chaperones, reduced the accumulation of damaged proteins, stimulated proteasomal activities, increased the cellular resistance to other stresses, enhanced the levels of various antioxidant enzymes, enhanced the activity and amounts of sodium-potassium pump, and increased the phosphorylation-mediated activities of various stress kinases. We have now observed novel hormetic effects of mild heat stress on improving the wound healing capacity of skin fibroblasts and on enhancing the angiogenic ability of endothelial cells. We have also tested potential hormetins, such as curcumin and rosmarinic acid in bringing about their beneficial effects in human cells by inducing stress response pathways involving heat shock proteins and hemeoxygenase HO-1. These data further support the view that mild stress-induced hormesis can be applied for the modulation, intervention and prevention of aging and age-related impairments. PMID:19343114

  1. Voluntary exercise and tail shock have differential effects on amphetamine-induced dopaminergic toxicity in adult BALB/c mice.

    PubMed

    Carlson, Kirsten M; Wagner, George C

    2006-09-01

    Exercise exerts neuroprotective effects and facilitates neural recovery in animal models of Parkinson's disease. In the present studies, effects of exercise on amphetamine-induced dopaminergic toxicity were assessed in mice housed individually either with or without access to run wheels. Mice in run wheel cages ran approximately 20 000 revolutions/day (over 10 km/day). Some mice received amphetamine (18.5 mg/kg x 4 injections) whereas controls received saline. Amphetamine caused a 90% dopamine depletion in mice housed either with or without run wheels. A precipitous drop was seen in run wheel activity following amphetamine, lasting at least 7 days. A significant decrease in food intake, water intake and body weight also occurred. The opportunity to exercise did not facilitate behavioral or neurochemical recovery at 1, 2 or 3 days, or 2 weeks after injections. Therefore, shock stress, a component of some forced exercise studies, was evaluated to determine whether stress without exercise provided neuroprotection against amphetamine. Results indicate that shock stress exerted neuroprotective effects, reducing the amphetamine-induced dopamine depletion. It is concluded that voluntary running does not afford either behavioral or neuroprotection nor facilitate recovery from amphetamine-induced dopaminergic toxicity; rather, elevated glucocorticoid levels following shock stress were associated with a reduction in the dopamine depletion.

  2. Differential effects of grape juice on gastric emptying and renal function from cisplatin-induced acute adverse toxicity.

    PubMed

    Ko, J-L; Tsai, C-H; Liu, T-C; Lin, M-Y; Lin, H-L; Ou, C-C

    2016-08-01

    Grape skin and seeds contain large amounts of phytochemicals such as polyphenols, resveratrol, and proanthocyanidins, which possess antioxidant activities. Cisplatin is widely used in the treatment of cancer. High doses of cisplatin have also been known to produce acute adverse effects. The aim of this study was to investigate the protective effects of antioxidant properties of whole grape juice (with skin and seeds) on cisplatin-induced acute gastrointestinal tract disorders and nephrotoxicity in Wistar rats. Gastric emptying is significantly increased in whole grape juice-pretreated rats when compared to cisplatin treatment alone. The expression of ghrelin mRNA of stomach is increased in rats with whole grape juice. However, pretreatment with whole grape juice did not reduce renal function markers in acute renal toxicity. No significant changes were recorded in the oxidative stress/antioxidant status parameters of any study group. In contrast, pretreatment with whole grape juice slightly improved tubular cell vacuolization, tubular dilatation, and cast formation in renal tubules. These results show that consumption of whole grape juice induces somewhat beneficial effects in preventing cisplatin-mediated dyspepsia but does not offer protection against cisplatin-induced acute renal toxicity.

  3. Statins in lymphangioleiomyomatosis. Simvastatin and atorvastatin induce differential effects on tuberous sclerosis complex 2-null cell growth and signaling.

    PubMed

    Atochina-Vasserman, Elena N; Goncharov, Dmitry A; Volgina, Alla V; Milavec, Megan; James, Melane L; Krymskaya, Vera P

    2013-11-01

    Mutations of the tumor suppressor genes tuberous sclerosis complex (TSC)1 and TSC2 cause pulmonary lymphangioleiomyomatosis (LAM) and tuberous sclerosis (TS). Current rapamycin-based therapies for TS and LAM have a predominantly cytostatic effect, and disease progression resumes with therapy cessation. Evidence of RhoA GTPase activation in LAM-derived and human TSC2-null cells suggests that 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor statins can be used as potential adjuvant agents. The goal of this study was to determine which statin (simvastatin or atorvastatin) is more effective in suppressing TSC2-null cell growth and signaling. Simvastatin, but not atorvastatin, showed a concentration-dependent (0.5-10 μM) inhibitory effect on mouse TSC2-null and human LAM-derived cell growth. Treatment with 10 μM simvastatin induced dramatic disruption of TSC2-null cell monolayer and cell rounding; in contrast, few changes were observed in cells treated with the same concentration of atorvastatin. Combined treatment of rapamycin with simvastatin but not with atorvastatin showed a synergistic growth-inhibitory effect on TSC2-null cells. Simvastatin, but not atorvastatin, inhibited the activity of prosurvival serine-threonine kinase Akt and induced marked up-regulation of cleaved caspase-3, a marker of cell apoptosis. Simvastatin, but not atorvastatin, also induced concentration-dependent inhibition of p42/p44 Erk and mTORC1. Thus, our data show growth-inhibitory and proapoptotic effects of simvastatin on TSC2-null cells compared with atorvastatin. These findings have translational significance for combinatorial therapeutic strategies of simvastatin to inhibit TSC2-null cell survival in TS and LAM.

  4. Differential modulation of a radiation-induced bystander effect in glioblastoma cells by pifithrin-α and wortmannin

    NASA Astrophysics Data System (ADS)

    Shao, Chunlin; Zhang, Jianghong; Prise, Kevin M.

    2010-03-01

    The implication of radiation-induced bystander effect (RIBE) for both radiation protection and radiotherapy has attracted significant attention, but a key question is how to modulate the RIBE. The present study found that, when a fraction of glioblastoma cells in T98G population were individually targeted with precise helium particles through their nucleus, micronucleus (MN) were induced and its yield increased non-linearly with radiation dose. After co-culturing with irradiated cells, additional MN could be induced in the non-irradiated bystander cells and its yield was independent of irradiation dose, giving direct evidence of a RIBE. Further results showed that the RIBE could be eliminated by pifithrin-α (p53 inhibitor) but enhanced by wortmannin (PI3K inhibitor). Moreover, it was found that nitric oxide (NO) contributed to this RIBE, and the levels of NO of both irradiated cells and bystander cells could be extensively diminished by pifithrin-α but insignificantly reduced by wortmannin. Our results indicate that RIBE can be modulated by p53 and PI3K through a NO-dependent and NO-independent pathway, respectively.

  5. Effects of atomic bomb radiation on the differentiation of B lymphocytes and on the function of concanavalin A-induced suppressor T lymphocytes.

    PubMed

    Yamada, Y; Neriishi, S; Ishimaru, T; Shimba, N; Hamilton, H B; Ohgushi, Y; Koyanagi, M; Ichimaru, M

    1985-02-01

    The differentiation of peripheral blood B lymphocytes into immunoglobulin-producing cells (Ig-PC) by pokeweed mitogen (PWM) and the function of concanavalin A (Con A)-induced suppressor T lymphocytes were examined to elucidate the late effects of atomic bomb radiation. A total of 140 individuals, 70 with an exposure dose of 100 rad or more and an equal number with an exposure dose of 0 rad matched by sex and age, were selected from the Nagasaki Adult Health Study (AHS) sample. Both the differentiation of peripheral blood B lymphocytes into Ig-PC by PWM and the function of Con A-induced suppressor T lymphocytes tended to be more depressed in the exposed group than in the control group, but a statistically significant difference could not be observed between the two groups. The function of Con A-induced suppressor T lymphocytes tended to decrease with age, but a statistical significance was detected only for percentage suppression against IgM-PC.

  6. Localization of the Energy States of Lead Inducing the Effect of Rectification and Negative Differential Resistance Predicted by First-Principles Study

    NASA Astrophysics Data System (ADS)

    Min, Y.; Fang, J. H.; Zhong, C. G.; Dong, Z. C.; Chen, C. P.; Yao, K. L.

    2013-07-01

    The first-principles calculations of the transport characteristics of 4-(5-(2-(5-(4-mercaptophenyl)thiophene-2-yl)ethyl)pyridin-2-yl)benzenethiol sandwiched between two gold leads are performed. The effect of rectification and negative differential resistance (NDR) are obtained, which promise the potential applications in the field of molecular electronics. The rectification effect is 4.49. The peak/valley ratio of the NDR effect is as large as 4.51 for the forward bias and 12.09 for the reverse bias. The strong coupling between gold lead and molecule through thiolate results in the localization of the energy states of gold lead, which may induce the effect of rectification and NDR.

  7. Differential effects of histone deacetylase inhibitors on phorbol ester- and TGF-beta1 induced murine tissue inhibitor of metalloproteinases-1 gene expression.

    PubMed

    Young, David A; Billingham, Olivia; Sampieri, Clara L; Edwards, Dylan R; Clark, Ian M

    2005-04-01

    Expression of the tissue inhibitor of metalloproteinases-1 (Timp-1) gene can be induced by either phorbol myristate acetate (PMA) or transforming growth factor beta1 (TGF-beta1), although the signalling pathways involved are not clearly defined. Canonically, histone deacetylase inhibitors (HDACi) such as trichostatin A (TSA) or sodium butyrate (NaB) increase total cellular histone acetylation and activate expression of susceptible genes. Remarkably, PMA and TGF-beta1 stimulation of Timp-1 show a differential response to TSA or NaB. TSA or NaB potentiate PMA-induced Timp-1 expression but repress TGF-beta1-induced Timp-1 expression. The repression of TGF-beta1-induced Timp-1 by TSA was maximal at 5 ng.mL(-1), while for the superinduction of PMA-induced Timp-1 expression, the maximal dose is > 500 ng x mL(-1) TSA. A further HDACi, valproic acid, did not block TGF-beta1-induced Timp-1 expression, demonstrating that different HDACs impact on the induction of Timp-1. For either PMA or TGF-beta1 to induce Timp-1 expression, new protein synthesis is required, and the induction of AP-1 factors closely precedes that of Timp-1. The effects of the HDACi can be reiterated in transient transfection using Timp-1 promoter constructs. Mutation or deletion of the AP-1 motif (-59/-53) in the Timp-1 promoter diminishes PMA-induction of reporter constructs, however, the further addition of TSA still superinduces the reporter. In c-Jun-/- cells, PMA still stimulates Timp-1 expression, but TSA superinduction is lost. Transfection of a series of Timp-1 promoter constructs identified three regions through which TSA superinduces PMA-induced Timp-1 and we have demonstrated specific protein binding to two of these regions which contain either an avian erythroblastosis virus E26 (v-ets) oncogene homologue (Ets) or Sp1 binding motif.

  8. Differential effects of environment-induced changes in body temperature on modafinil's actions against methamphetamine-induced striatal toxicity in mice.

    PubMed

    Raineri, Mariana; González, Betina; Rivero-Echeto, Celeste; Muñiz, Javier A; Gutiérrez, María Laura; Ghanem, Carolina I; Cadet, Jean Lud; García-Rill, Edgar; Urbano, Francisco J; Bisagno, Veronica

    2015-01-01

    Methamphetamine (METH) exposure can produce hyperthermia that might lead to toxicity and death. Modafinil is a wake-promoting compound that is also been prescribed off-label to treat METH dependence. Modafinil has shown neuroprotective properties against METH harmful effects in animal models. The goal of the present study was to test if the prevention of hyperthermia might play a role on the neuroprotective actions of modafinil against METH toxicity using various ambient temperatures. METH was administered to female C57BL/6 mice in a binge regimen: 4 × 5 mg/kg, 2 h apart; modafinil (90 mg/kg) was injected twice, 1 h before first and fourth METH injections. Drugs were given at cold ambient temperature (14 °C) or hot ambient temperature (29 °C). Body temperature was measured during treatments. Brains were dissected out 6 days after treatments and processed for tyrosine hydroxylase (TH), dopamine transporter (DAT), GFAP and c-Fos immunohistochemistry. Exposure to hot ambient temperature exacerbated METH toxicity evidenced by striatal reductions in TH and DAT and increased GFAP immmunoreactivity. Modafinil counteracted reductions in TH and DAT, but failed to block astroglial activation. At both ambient temperatures tested modafinil did induce increments in GFAP, but the magnitude was significantly lower than the one induced by METH. Both drugs induced increases in c-Fos positive nuclei; modafinil did not block this effect. Our results suggest that protective effects of modafinil against METH-induced neurotoxicity may be dependent, in part, to its hypothermic effects. Nevertheless, modafinil maintained some protective properties on METH-induced alterations in the striatum at different ambient temperatures.

  9. Serotonin and sudden death: differential effects of serotonergic drugs on seizure-induced respiratory arrest in DBA/1 mice.

    PubMed

    Faingold, Carl L; Kommajosyula, Srinivasa P; Long, X; Plath, Kristin; Randall, Marcus

    2014-08-01

    In the DBA/1 mouse model of sudden unexpected death in epilepsy (SUDEP), administration of a selective serotonin (5-HT) reuptake inhibitor (SSRI), fluvoxamine, completely suppressed seizure-induced respiratory arrest (S-IRA) at 30 min after administration (i.p.) in a dose-related manner without blocking audiogenic seizures (AGSz), but another SSRI, paroxetine, reduced S-IRA but with a delayed (24 h) onset and significant toxicity. A serotonin-norepinephrine reuptake inhibitor, venlafaxine, reduced S-IRA incidence, but higher doses were ineffective. A selective 5-HT7 agonist, AS-19, was totally ineffective in reducing S-IRA. In developing DBA/1 mice that had not previously experienced AGSz, administration of a nonselective 5-HT antagonist, cyproheptadine, induced a significantly greater incidence of S-IRA than that of saline. This study confirms that certain drugs that enhance the activation of 5-HT receptors are able to prevent S-IRA, but not all serotonergic drugs are equally effective, which may be relevant to the potential use of these drugs for SUDEP prevention. Serotonergic antagonists may be problematic in patients with epilepsy.

  10. Effect of Glutamate and Riluzole on Manganese-Induced Apoptotic Cell Signaling in Neuronally Differentiated Mouse P19 Cells

    PubMed Central

    Roth, Jerome A.; Sridhar, Swetha; Singleton, Steven T.

    2012-01-01

    Excess exposure to Mn causes a neurological disorder known as manganism which is similar to dystonic movements associated with Parkinson’s disease. Manganism is largely restricted to occupations in which high atmospheric levels are prevalent which include Mn miners, welders and those employed in the ferroalloy processing or related industrial settings. T1 weighted MRI images reveal that Mn is deposited to the greatest extent in the globus pallidus, an area of the brain that is presumed to be responsible for the major CNS associated symptoms. Neurons within the globus pallidus receive glutamatergic input from the subthalamic nuclei which has been suggested to be involved in the toxic actions of Mn. The neurotoxic actions of Mn and glutamate are similar in that they both affect calcium accumulation in the mitochondria leading to apoptotic cell death. In this paper we demonstrate that the combination of Mn and glutamate potentiates toxicity of neuronally differentiated P19 cells over that observed with either agent alone. Apoptotic signals ROS, caspase 3 and JNK were increased in an additive fashion when the two neurotoxins were combined. The anti-glutamatergic drug, riluzole, was shown to attenuate these apoptotic signals and prevent P19 cell death. Results of this study confirm, for the first time, that Mn toxicity is potentiated in the presence of glutamate and that riluzole is an effective antioxidant which protects against both Mn and glutamate toxicity. PMID:22543103

  11. Differential effects of beta-naphthoflavone and pregnenolone-16alpha-carbonitrile on dimethylnitrosamine-induced hepatocarcinogenesis.

    PubMed

    Argus, M F; Hoch-Ligeti, C; Arcos, J C; Conney, A H

    1978-08-01

    The effect of administration of beta-naphthoflavone (beta-NF) or pregnenolone-16alpha-carbonitrile (PCN) on the hepatocarcinogenicity of dimethylnitrosamine (DMN) in male SD rats was explored. Both beta-NF and PCN are potent repressors of the low Michaelis constant enzymatic form of DMN-demethylase, a mixed-function oxidase that catalyzes DMN demethylation. DMN-induced hepatocarcinogenesis was inhibited by PCN and was enhanced by beta-NF. Seven liver tumors were found in 45 rats fed DMN plus PCN compared to 14 liver tumors in 43 rats fed DMN alone; 32 liver tumors were found in 43 rats fed DMN plus beta-NF. No liver tumors were detected in rats that received only PCN, beta-NF, or the administration vehicles. Of the 53 liver tumors observed, 53% were angiosarcomas; this type of tumor was found in all 3 groups of rats that received DMN.

  12. Hypoxia-inducible factor-2α: effect on radiation sensitivity and differential regulation by an mTOR inhibitor

    PubMed Central

    Bhatt, Rupal S.; Landis, Daniel M.; Zimmer, Michael; Torregrossa, Joelle; Chen, Shaoyong; Sukhatme, Vikas P.; Iliopoulos, Othon; Balk, Steve; Bubley, Glenn J.

    2014-01-01

    OBJECTIVE To determine the role of hypoxia-inducible factor-2α (HIF2α) on the sensitivity of renal cell carcinoma (RCC) cell lines to ionizing radiation and to determine if the mTOR antagonist, rapamycin, could decrease HIF2α protein levels. MATERIALS AND METHODS Cell lines expressing stable short-hairpin RNAs (shRNAs) encoding HIF2α shRNAs or an empty vector were transfected with a hypoxia responsive element (HRE)-driven firefly luciferase reporter gene. Two separate paired cell lines were assayed for their response to increasing doses of ionizing radiation. Proliferation and cell cycle kinetics were compared for cell lines expressing HIF2α shRNAs and empty vectors. The effect of an mTOR antagonist, rapamycin on HIF1α and HIF2α proteins levels was also assessed. RESULTS We confirmed that the 786-O RCC lines with stably integrated shRNAs against HIF2α had decreased activation of a plasmid with a HRE-driven firefly luciferase reporter gene. Lines from two separate cell clones with decreased HIF2α levels showed a significant increase in radiation sensitivity and an increase in G2 cell cycle arrest. Rapamycin, while effective in decreasing HIF1α protein levels, did not affect HIF2α levels in either of the RCC cell lines. CONCLUSIONS These results show that decreasing levels of HIF2α leads to an increased sensitivity to ionizing radiation. This finding may explain in part, the known resistance of RCC to radiation therapy. Although mTOR antagonists are approved for the treatment of RCC, these agents do not decrease HIF2α levels and therefore might not be effective in enhancing the radio-sensitivity of these tumours. PMID:18394010

  13. Effect of the PI3K/AKT signaling pathway on hypoxia-induced proliferation and differentiation of bone marrow-derived mesenchymal stem cells

    PubMed Central

    Sheng, Lingling; Mao, Xiyuan; Yu, Qingxiong; Yu, Dong

    2017-01-01

    Bone marrow-derived mesenchymal stem cell (BM-MSC) transplantation has been demonstrated to be an effective way of augmenting angiogenesis of ischemic tissue. The low oxygen conditions in ischemic tissue directly affect the biological behavior of engrafted cells. However, to date, the mechanism through which hypoxia regulates self-renewal, differentiation and paracrine function of BM-MSCs remains unclear. Clarification of this mechanism would be beneficial to the use of stem cell-based therapy. The PI3K/AKT pathway has been extensively investigated for its role in cell proliferation, cell transformation, paracrine function and angiogenesis. The present study aimed to analyze the role of PI3K/AKT pathway in hypoxia-induced proliferation of BM-MSCs and their differentiation into endothelial cells in vitro by the application of LY294002, a PI3K/AKT pathway inhibitor, with cells cultured in normoxia serving as a control. The results showed that rat BM-MSCs at passage 3 and 4 displayed only few phenotypical differences in the expression of surface antigens as detected by flow cytometry. When compared with the cells treated in normoxia, the proliferation of BM-MSCs in hypoxia was promoted, a greater number of cells expressed CD31 and a higher expression of vascular endothelial growth factor was observed after culture in hypoxic conditions. However, by inhibiting with LY294002, these changes induced by hypoxia were partly inhibited. In conclusion, the present study showed that the PI3K/AKT pathway served an important role in hypoxia-enhanced in vitro proliferation of BM-MSCs and their differentiation into endothelial cells and paracrine vascular endothelial growth factor. PMID:28123468

  14. Kinetics of CO binding to the haem domain of murine inducible nitric oxide synthase: differential effects of haem domain ligands.

    PubMed Central

    Stevenson, T H; Gutierrez, A F; Alderton, W K; Lian , L; Scrutton, N S

    2001-01-01

    The binding of CO to the murine inducible nitric oxide synthase (iNOS) oxygenase domain has been studied by laser flash photolysis. The effect of the (6R)-5,6,7,8-tetrahydro-L-biopterin (BH(4)) cofactor L-arginine and several Type I L-arginine analogues/ligands on the rates of CO rebinding has been evaluated. The presence of BH(4) in the iNOS active site has little effect on the rebinding of protein-caged haem-CO pairs (geminate recombination), but decreases the bimolecular association rates 2-fold. Addition of L-arginine to the BH(4)-bound complex completely abolishes geminate recombination and results in a further 80-fold decrease in the overall rate of bimolecular association. Three of the Type I ligands, S-ethylisothiourea, L-canavanine and 2,5-lutidine, displaced the CO from the haem iron upon addition to the iNOS oxygenase domain. The Type I ligands significantly decreased the rate of bimolecular binding of CO to the haem iron after photolysis. Most of these ligands also completely abolished geminate recombination. These results are consistent with a relatively open distal pocket that allows CO to bind unhindered in the active site of murine iNOS in the absence of L-arginine or BH(4). In the presence of BH(4) and L-arginine, however, the enzyme adopts a more closed structure that can greatly reduce ligand access to the haem iron. These observations are discussed in terms of the known structure of iNOS haem domain and solution studies of ligand binding in iNOS and neuronal NOS isoenzymes. PMID:11485568

  15. Differential effects of prenatal stress on metabolic programming in diet-induced obese and dietary-resistant rats

    PubMed Central

    Balasubramanian, Priya; Varde, Pratibha A.; Abdallah, Simon Labib; Najjar, Sonia M.; MohanKumar, P. S.

    2015-01-01

    Stress during pregnancy is a known contributing factor for the development of obesity in the offspring. Since maternal obesity is on the rise, we wanted to identify the effects of prenatal stress in the offspring of diet-induced obese (DIO) rats and compare them with the offspring of dietary-resistant (DR) rats. We hypothesized that prenatal stress would make both DIO and DR offspring susceptible to obesity, but the effect would be more pronounced in DIO rats. Pregnant DIO and DR rats were divided into two groups: nonstressed controls (control) and prenatal stress (subjected to restraint stress, three times/day from days 14 to 21 of gestation). After recording birth weight and weaning weight, male offspring were weaned onto a chow diet for 9 wk and shifted to a high-fat (HF) diet for 1 wk. At the end of the 10th wk the animals were euthanized, and visceral adipose mass, blood glucose, serum insulin, and C-peptide levels were measured. Prenatal stress resulted in hyperinsulinemia and higher C-peptide levels without altering caloric intake, body weight gain, or fat mass in the DIO offspring after 1 wk of HF intake, but not in DR offspring. To determine the mechanism underlying the hyperinsulinemia, we measured the levels of CEACAM1 that are responsible for insulin clearance. CEACAM1 levels in the liver were reduced in prenatally stressed DIO offspring after the HF challenge, suggesting that preexisting genetic predisposition in combination with prenatal stress increases the risk for obesity in adulthood, especially when offspring are fed a HF diet. PMID:26219866

  16. Ethanol-Induced ADH Activity in Zebrafish: Differential Concentration-Dependent Effects on High- Versus Low-Affinity ADH Enzymes.

    PubMed

    Tran, Steven; Nowicki, Magda; Facciol, Amanda; Chatterjee, Diptendu; Gerlai, Robert

    2016-04-01

    Zebrafish express enzymes that metabolize ethanol in a manner comparable to that of mammals, including humans. We previously demonstrated that acute ethanol exposure increases alcohol dehydrogenase (ADH) activity in an inverted U-shaped dose-dependent manner. It was hypothesized that the biphasic dose-response was due to the increased activity of a high-affinity ADH isoform following exposure to low concentrations of ethanol and increased activity of a low-affinity ADH isoform following exposure to higher concentrations of ethanol. To test this hypothesis, we exposed zebrafish to different concentrations of ethanol (0%, 0.25%, 0.5%, and 1.0% v/v) for 30 min and measured the total ADH activity in the zebrafish liver. However, we also repeated this enzyme activity assay using a low concentration of the substrate (ethanol) to determine the activity of high-affinity ADH isoforms. We found that total ADH activity in response to ethanol induces an inverted U-shaped dose-response similar to our previous study. Using a lower substrate level in our enzyme assay targeting high-affinity isozymes, we found a similar dose-response. However, the difference in activity between the high and low substrate assays (high substrate activity - low substrate activity), which provide an index of activity for low-affinity ADH isoforms, revealed no significant effect of ethanol exposure. Our results suggest that the inverted U-shaped dose-response for total ADH activity in response to ethanol is driven primarily by high-affinity isoforms of ADH.

  17. Celiac anti-type 2 transglutaminase antibodies induce differential effects in fibroblasts from celiac disease patients and from healthy subjects.

    PubMed

    Paolella, Gaetana; Lepretti, Marilena; Barone, Maria Vittoria; Nanayakkara, Merlin; Di Zenzo, Marina; Sblattero, Daniele; Auricchio, Salvatore; Esposito, Carla; Caputo, Ivana

    2017-03-01

    Type 2 transglutaminase (TG2) has an important pathogenic role in celiac disease (CD), an inflammatory intestinal disease that is caused by the ingestion of gluten-containing cereals. Indeed, TG2 deamidates specific gliadin peptides, thus enhancing their immunogenicity. Moreover, the transamidating activity seems to provoke an autoimmune response, where TG2 is the main autoantigen. Many studies have highlighted a possible pathogenetic role of anti-TG2 antibodies, because they modulate TG2 enzymatic activity and they can interact with cell-surface TG2, triggering a wide range of intracellular responses. Autoantibodies also alter the uptake of the alpha-gliadin peptide 31-43 (p31-43), responsible of the innate immune response in CD, thus partially protecting cells from p31-43 damaging effects in an intestinal cell line. Here, we investigated whether anti-TG2 antibodies protect cells from p31-43-induced damage in a CD model consisting of primary dermal fibroblasts. We found that the antibodies specifically reduced the uptake of p31-43 by fibroblasts derived from healthy subjects but not in those derived from CD patients. Analyses of TG2 expression and enzymatic activity did not reveal any significant difference between fibroblasts from healthy and celiac subjects, suggesting that other features related to TG2 may be responsible of such different behaviors, e.g., trafficking or subcellular distribution. Our findings are in line with the concept that a "celiac cellular phenotype" exists and that TG2 may contribute to this phenotype. Moreover, they suggest that the autoimmune response to TG2, which alone may damage the celiac mucosa, also fails in its protective role in celiac cells.

  18. Investigation of the effect of α-melanocyte-stimulating hormone on proliferation and early stages of differentiation of human induced pluripotent stem cells.

    PubMed

    Novosadova, E V; Manuilova, E S; Arsenyeva, E L; Andreeva, L A; Lebedeva, O S; Grivennikov, I A; Myasoedov, N F

    2016-03-01

    We have studied the influence of α-melanocyte-stimulating hormone (α-MSH) on proliferation and early stages of differentiation of human induced pluripotent stem cells (iPSc). We have demonstrated that α-MSH receptor genes are expressed in undifferentiated iPSc. The expression levels of MCR1, MCR2, and MCR3 increased at the embryoid body (EB) formation stage. The formation of neural progenitors was accompanied by elevation of MCR2, MCR3, and MCR4 expression. α-MSH had no effect on EB generation and iPSc proliferation at concentrations ranging from 1 nM to 10 μM. At the same time, α-MSH increased the generation of neural rosettes in human iPSc cultures more than twice.

  19. The hippocampus and cingulate cortex differentially mediate the effects of nicotine on learning versus on ethanol-induced learning deficits through different effects at nicotinic receptors.

    PubMed

    Gulick, Danielle; Gould, Thomas J

    2009-08-01

    The current study examined the effects of nicotine infusion into the dorsal hippocampus or anterior cingulate on fear conditioning and on ethanol-induced deficits in fear conditioning, and whether these effects involved receptor activation or inactivation. Conditioning consisted of two white noise (30 s, 85 dB)-foot-shock (2 s, 0.57 mA) pairings. Saline or ethanol was administered to C57BL/6 mice 15 min before training and saline or nicotine was administered 5 min before training or before training and testing. The ability of the high-affinity nicotinic acetylcholinergic receptor (nAChR) antagonist dihydro-beta-erythroidine (DHbetaE) to modulate the effects of ethanol and nicotine was also tested; saline or DHbetaE was administered 25 (injection) or 15 (infusion) minutes before training or before training and testing. Infusion of nicotine into the hippocampus enhanced contextual fear conditioning but had no effect on ethanol-induced learning deficits. Infusion of nicotine into the anterior cingulate ameliorated ethanol-induced deficits in contextual and cued fear conditioning but had no effect on learning in ethanol-naive mice. DHbetaE blocked the effects of nicotine on ethanol-induced deficits; interestingly, DHbetaE alone and co-administration of subthreshold doses of DHbetaE and nicotine also ameliorated ethanol-induced deficits but failed to enhance learning. Finally, DHbetaE failed to ameliorate ethanol-induced deficits in beta2 nAChR subunit knockout mice. These results suggest that nicotine acts in the hippocampus to enhance contextual learning, but acts in the cingulate to ameliorate ethanol-induced learning deficits through inactivation of high-affinity beta2 subunit-containing nAChRs.

  20. Half-metallic properties, single-spin negative differential resistance, and large single-spin Seebeck effects induced by chemical doping in zigzag-edged graphene nanoribbons.

    PubMed

    Yang, Xi-Feng; Zhou, Wen-Qian; Hong, Xue-Kun; Liu, Yu-Shen; Wang, Xue-Feng; Feng, Jin-Fu

    2015-01-14

    Ab initio calculations combining density-functional theory and nonequilibrium Green's function are performed to investigate the effects of either single B atom or single N atom dopant in zigzag-edged graphene nanoribbons (ZGNRs) with the ferromagnetic state on the spin-dependent transport properties and thermospin performances. A spin-up (spin-down) localized state near the Fermi level can be induced by these dopants, resulting in a half-metallic property with 100% negative (positive) spin polarization at the Fermi level due to the destructive quantum interference effects. In addition, the highly spin-polarized electric current in the low bias-voltage regime and single-spin negative differential resistance in the high bias-voltage regime are also observed in these doped ZGNRs. Moreover, the large spin-up (spin-down) Seebeck coefficient and the very weak spin-down (spin-up) Seebeck effect of the B(N)-doped ZGNRs near the Fermi level are simultaneously achieved, indicating that the spin Seebeck effect is comparable to the corresponding charge Seebeck effect.

  1. Half-metallic properties, single-spin negative differential resistance, and large single-spin Seebeck effects induced by chemical doping in zigzag-edged graphene nanoribbons

    SciTech Connect

    Yang, Xi-Feng; Zhou, Wen-Qian; Hong, Xue-Kun; Liu, Yu-Shen Feng, Jin-Fu; Wang, Xue-Feng

    2015-01-14

    Ab initio calculations combining density-functional theory and nonequilibrium Green’s function are performed to investigate the effects of either single B atom or single N atom dopant in zigzag-edged graphene nanoribbons (ZGNRs) with the ferromagnetic state on the spin-dependent transport properties and thermospin performances. A spin-up (spin-down) localized state near the Fermi level can be induced by these dopants, resulting in a half-metallic property with 100% negative (positive) spin polarization at the Fermi level due to the destructive quantum interference effects. In addition, the highly spin-polarized electric current in the low bias-voltage regime and single-spin negative differential resistance in the high bias-voltage regime are also observed in these doped ZGNRs. Moreover, the large spin-up (spin-down) Seebeck coefficient and the very weak spin-down (spin-up) Seebeck effect of the B(N)-doped ZGNRs near the Fermi level are simultaneously achieved, indicating that the spin Seebeck effect is comparable to the corresponding charge Seebeck effect.

  2. Half-metallic properties, single-spin negative differential resistance, and large single-spin Seebeck effects induced by chemical doping in zigzag-edged graphene nanoribbons

    NASA Astrophysics Data System (ADS)

    Yang, Xi-Feng; Zhou, Wen-Qian; Hong, Xue-Kun; Liu, Yu-Shen; Wang, Xue-Feng; Feng, Jin-Fu

    2015-01-01

    Ab initio calculations combining density-functional theory and nonequilibrium Green's function are performed to investigate the effects of either single B atom or single N atom dopant in zigzag-edged graphene nanoribbons (ZGNRs) with the ferromagnetic state on the spin-dependent transport properties and thermospin performances. A spin-up (spin-down) localized state near the Fermi level can be induced by these dopants, resulting in a half-metallic property with 100% negative (positive) spin polarization at the Fermi level due to the destructive quantum interference effects. In addition, the highly spin-polarized electric current in the low bias-voltage regime and single-spin negative differential resistance in the high bias-voltage regime are also observed in these doped ZGNRs. Moreover, the large spin-up (spin-down) Seebeck coefficient and the very weak spin-down (spin-up) Seebeck effect of the B(N)-doped ZGNRs near the Fermi level are simultaneously achieved, indicating that the spin Seebeck effect is comparable to the corresponding charge Seebeck effect.

  3. Inhibitory effects of psychotomimetic sigma ligands on nicotine-induced K+ flux from differentiated PC12 cells.

    PubMed

    Yamamoto, H; Sagi, N; Yamamoto, T; Goji, Y; Okuwa, M; Yoshii, M; Moroji, T

    1992-11-23

    In NGF-treated PC12 cells, nicotine-induced K+ release was measured with a K(+)-sensitive microelectrode. The K+ outflow via nicotinic ACh receptor cation channels was inhibited by various psychotomimetic sigma ligands in the sequence of PCP, dextromethorphan > DTG, MK 801, (+)SKF10047 > (+)3-PPP. The K+ release was not affected by the neuroleptic sigma ligand haloperidol nor by the calcium antagonist nifedipine. The results suggest that psychotomimetic sigma ligands inhibit nicotine-stimulated K+ flux by interacting with nicotinic, rather than via sigma 2 receptors.

  4. Methamphetamine-, d-Amphetamine-, and p-Chloroamphetamine-Induced Neurotoxicity Differentially Effect Impulsive Responding on the Stop-Signal Task in Rats.

    PubMed

    Furlong, Teri M; Leavitt, Lee S; Keefe, Kristen A; Son, Jong-Hyun

    2016-05-01

    Abused amphetamines, such as d-amphetamine (AMPH) and methamphetamine (METH), are highly addictive and destructive to health and productive lifestyles. The abuse of these drugs is associated with impulsive behavior, which is likely to contribute to addiction. The amphetamines also differentially damage dopamine (DA) and serotonin (5-HT) systems, which regulate impulsive behavior; therefore, exposure to these drugs may differentially alter impulsive behavior to effect the progression of addiction. We examined the impact of neurotoxicity induced by three amphetamines on impulsive action using a stop-signal task in rats. Animals were rewarded with a food pellet after lever pressing (i.e., a go trial), unless an auditory cue was presented and withholding lever press gained reward (i.e., a stop trial). Animals were trained on the task and then exposed to a neurotoxic regimen of either AMPH, p-chloroamphetamine (PCA), or METH. These regimens preferentially reduced DA transporter levels in striatum, 5-HT transporter levels in prefrontal cortex, or both, respectively. Assessment of performance on the stop-signal task beginning 1 week after the treatment revealed that AMPH produced a deficit in go-trial performance, whereas PCA did not alter performance on either trial type. In contrast, METH produced a deficit in stop-trial performance (i.e., impulsive action) but not go-trial performance. These findings suggest that the different neurotoxic consequences of substituted amphetamines are associated with different effects on inhibitory control over behavior. Thus, the course of addiction and maladaptive behavior resulting from exposure to these substances is likely to differ.

  5. Differential effects and glucocorticoid potentiation of bone morphogenetic protein action during rat osteoblast differentiation in vitro.

    PubMed

    Boden, S D; McCuaig, K; Hair, G; Racine, M; Titus, L; Wozney, J M; Nanes, M S

    1996-08-01

    Bone morphogenetic proteins (BMPs) induce cartilage and bone differentiation in vivo and promote osteoblast differentiation from calvarial and marrow stromal cell preparations. Functional differences between BMP-2, -4, and -6 are not well understood. Recent investigations find that these three closely related osteoinductive proteins may exert different effects in primary rat calvarial cell cultures, suggesting the possibility of unique functions in vivo. In this study, we use a fetal rat secondary calvarial cell culture system to examine the differential effects of BMP-2, -4, and -6 on early osteoblast differentiation. These cells do not spontaneously differentiate into osteoblasts, as do cells in primary calvarial cultures, but rather require exposure to a differentiation initiator such as glucocorticoid or BMP. We determined that BMP-6 is a 2- to 2.5-fold more potent inducer of osteoblast differentiation than BMP-2 or -4. BMP-6 induced the formation of more and larger bone nodules as well as increased osteocalcin secretion. The effects of all three of these BMPs were potentiated up to 10-fold by cotreatment or pretreatment with the glucocorticoid triamcinolone (Trm). The Trm effects were synergistic with those of BMP-2 or -4, suggesting that this glucocorticoid may increase the cell responsiveness to these BMPs. Finally, BMP-6 did not require either cotreatment or pretreatment with Trm to achieve greater amounts of osteoblast differentiation than seen with BMP-2 or BMP-4 treatment, suggesting that BMP-6 may act at an earlier stage of cell differentiation.

  6. Enhanced D1 and D2 inhibitions induced by low-frequency trains of conditioning stimuli: differential effects on H- and T-reflexes and possible mechanisms.

    PubMed

    Mezzarane, Rinaldo André; Magalhães, Fernando Henrique; Chaud, Vitor Martins; Elias, Leonardo Abdala; Kohn, André Fabio

    2015-01-01

    Mechanically evoked reflexes have been postulated to be less sensitive to presynaptic inhibition (PSI) than the H-reflex. This has implications on investigations of spinal cord neurophysiology that are based on the T-reflex. Preceding studies have shown an enhanced effect of PSI on the H-reflex when a train of ~10 conditioning stimuli at 1 Hz was applied to the nerve of the antagonist muscle. The main questions to be addressed in the present study are if indeed T-reflexes are less sensitive to PSI and whether (and to what extent and by what possible mechanisms) the effect of low frequency conditioning, found previously for the H-reflex, can be reproduced on T-reflexes from the soleus muscle. We explored two different conditioning-to-test (C-T) intervals: 15 and 100 ms (corresponding to D1 and D2 inhibitions, respectively). Test stimuli consisted of either electrical pulses applied to the posterior tibial nerve to elicit H-reflexes or mechanical percussion to the Achilles tendon to elicit T-reflexes. The 1 Hz train of conditioning electrical stimuli delivered to the common peroneal nerve induced a stronger effect of PSI as compared to a single conditioning pulse, for both reflexes (T and H), regardless of C-T-intervals. Moreover, the conditioning train of pulses (with respect to a single conditioning pulse) was proportionally more effective for T-reflexes as compared to H-reflexes (irrespective of the C-T interval), which might be associated with the differential contingent of Ia afferents activated by mechanical and electrical test stimuli. A conceivable explanation for the enhanced PSI effect in response to a train of stimuli is the occurrence of homosynaptic depression at synapses on inhibitory interneurons interposed within the PSI pathway. The present results add to the discussion of the sensitivity of the stretch reflex pathway to PSI and its functional role.

  7. Activation of adenosine₁ receptors induces antidepressant-like, anti-impulsive effects on differential reinforcement of low-rate 72-s behavior in rats.

    PubMed

    Marek, Gerard J

    2012-05-01

    Stress and psychiatric illness have been associated with a dysregulation of glutamatergic neurotransmission. Recently, positive allosteric modulators (PAMs) of the metabotropic glutamate 2 (mGlu₂) receptor have been found to exert antidepressant-like activity in rats performing under a differential reinforcement of low rate (DRL) 72-s schedule. An autoreceptor role at glutamatergic synapses is the most salient physiological role played by the mGlu₂ receptor. Adenosine A₁ receptors play a heteroreceptor role at many of the same forebrain synapses where mGlu₂ autoreceptors are found. Agonists and/or PAMs of mGlu₂ receptors act similarly to adenosine A₁ receptor agonists with respect to a wide range of electrophysiological, biochemical, and behavioral responses mediated by limbic circuitry thought to play a role in the pathophysiology of neuropsychiatric disease and to mediate therapeutic drug effects. Therefore, the role of adenosine A₁ receptor activation on rat DRL 72-s behavior was explored to provide preclinical evidence consistent or inconsistent with potential antidepressant effects. The adenosine A₁ receptor agonist N⁶-cyclohexyladenosine (CHA) increased the reinforcement rate, decreased the response rate, and induced a rightward shift in inter-response time distributions in a dose-dependent fashion similar to most known antidepressant drugs. The adenosine A₁ receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) blocked these antidepressant-like effects. These novel observations with CHA and DPCPX suggest that activation of adenosine A₁ receptors could contribute to antidepressant effects, in addition to previous preclinical reports of anxiolytic and antipsychotic effects. By implication, targeting a dysregulated glutamatergic system may be an important principle in discovering novel antidepressant agents that may also possess anti-impulsive activity.

  8. UV-B induced differential effect on growth and nitrogen metabolism in two cyanobacteria under copper toxicity.

    PubMed

    Singh, V P; Srivastava, P K; Prasad, S M

    2012-12-22

    In the present study, impact of low (UV-B(L): 0.1 μmol m(-2) s(-1)) and high (UV-BH: 1.0 μmol m(-2) s(-1)) fluence rates of ultraviolet-B on growth and nitrogen metabolism in two cyanobacteria: Phormidium foveolarum and Nostoc muscorum under copper toxicity (2 and 5 μM) was investigated after 24 and 72 h of experiments. Copper and UV-BH treatment suppressed growth but more in N. muscorum which was accompanied by significant accumulation of Cu. Nitrate and nitrite uptake rates and activities of nitrogen assimilating enzymes i.e. nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS) and glutamate synthase (GOGAT) except glutamate dehydrogenase activity (GDH; aminating) were decreased following treatments of Cu and UV-BH, and under combined treatments the effect was greater. On contrary, UV-BL declined Cu toxicity significantly. The study concludes that Cu and UV-BH suppressed the activity of NR, NiR, GS and GOGAT (except GDH) hence decreased growth. However, UV-BL showed cross tolerance in test organisms against Cu toxicity up to certain extent. Phormidium foveolarum is comparatively less sensitive against UV-BH and excess Cu, a situation likely exists in nature, hence it may be used as a biofertilizer for sustainable agriculture.

  9. Differential effect of restraint procedure on incidence of restraint-stress-induced rib fusion in CD-1 mice.

    PubMed

    Rasco, J F; Hood, R D

    1994-04-01

    In an investigation of the effects of specific maternal stressors on development of the conceptus, pregnant mice were exposed to restraint stress on gestation day 9 (plug = day 1). Mated females were either unrestrained (C), unrestrained and food/water deprived (FWD), or restrained with surgical tape in a supine position for 12 h by one of two methods: I. 1-inch wide tape reaching from each shoulder across the body to the opposite thigh, or II. 1-inch wide tape placed over one shoulder, across the thorax, and over the opposite shoulder and similar tape placed over each thigh and across the intervening pelvic area. For both methods, an additional tape was placed across the tail and a 2-inch wide tape secured the upper abdominal area. There were 32 to 62 litters in each treatment group, and all fetuses were examined on day 18 for gross and skeletal defects. With regard to rib fusion, the percentage of affected fetuses and litters was increased (P < or = 0.05) by Method I (3.5% and 27%, respectively) vs. Method II. (0.5% and 4%), C (0.1% and 1%), or FWD (0%). Incidences of supernumerary ribs, however, did not differ between the restrained groups but were higher in both such groups than in the FWD and C groups. These results suggest that different methods of restraint may result in differences in incidence of rib fusion. Such data suggest that development of the offspring of stressed dams may be significantly influenced by what might appear to be minor differences in the stress techniques used.

  10. Differential effect of nimodipine in attenuating iron-induced toxicity in brain- and blood-brain barrier-associated cell types.

    PubMed

    Lockman, J A; Geldenhuys, W J; Bohn, K A; Desilva, S F; Allen, D D; Van der Schyf, C J

    2012-01-01

    Metal homeostasis is increasingly being evaluated as a therapeutic target in stroke and neurodegenerative diseases. Metal dysregulation has been shown to lead to protein aggregation, plaque formation and neuronal death. In 2007, we first reported that voltage-gated calcium channels act as a facile conduit for the entry of free ferrous (Fe(2+)) ions into neurons. Herein, we evaluate differential iron toxicity to central nervous system cells and assess the ability of the typical L-type voltage-gated calcium channel blocker nimodipine to attenuate iron-induced toxicity. The data demonstrate that iron sulfate induces a dose-dependent decrease in cell viability in rat brain endothelial cells (RBE4; LC(50) = 150 μM), neuronal cells (Neuro-2α neuroblastoma; LC(50) = 400 μM), and in astrocytes (DI TNC1; LC(50) = 1.1 mM). Pre-treatment with nimodipine prior to iron sulfate exposure provided a significant (P < 0.05) increase in viable cell numbers for RBE4 (2.5-fold), Neuro2-α (~2-fold), and nearly abolished toxicity in primary neurons. Astrocytes were highly resistant to iron toxicity compared to the other cell types tested and nimodipine had no (P > 0.05) protective effect in these cells. The data demonstrate variable susceptibility to iron overload conditions in different cell types of the brain and suggest that typical L-type voltage-gated calcium channel blockers (here represented by nimodipine), may serve as protective agents in conditions involving iron overload, particularly in cell types highly susceptible to iron toxicity.

  11. Differential effects of buffer pH on Ca2+-induced ROS emission with inhibited mitochondrial complexes I and III

    PubMed Central

    Lindsay, Daniel P.; Camara, Amadou K. S.; Stowe, David F.; Lubbe, Ryan; Aldakkak, Mohammed

    2015-01-01

    Excessive mitochondrial reactive oxygen species (ROS) emission is a critical component in the etiology of ischemic injury. Complex I and complex III of the electron transport chain are considered the primary sources of ROS emission during cardiac ischemia and reperfusion (IR) injury. Several factors modulate ischemic ROS emission, such as an increase in extra-matrix Ca2+, a decrease in extra-matrix pH, and a change in substrate utilization. Here we examined the combined effects of these factors on ROS emission from respiratory complexes I and III under conditions of simulated IR injury. Guinea pig heart mitochondria were suspended in experimental buffer at a given pH and incubated with or without CaCl2. Mitochondria were then treated with either pyruvate, a complex I substrate, followed by rotenone, a complex I inhibitor, or succinate, a complex II substrate, followed by antimycin A, a complex III inhibitor. H2O2 release rate and matrix volume were compared with and without adding CaCl2 and at pH 7.15, 6.9, or 6.5 with pyruvate + rotenone or succinate + antimycin A to simulate conditions that may occur during in vivo cardiac IR injury. We found a large increase in H2O2 release with high [CaCl2] and pyruvate + rotenone at pH 6.9, but not at pHs 7.15 or 6.5. Large increases in H2O2 release rate also occurred at each pH with high [CaCl2] and succinate + antimycin A, with the highest levels observed at pH 7.15. The increases in H2O2 release were associated with significant mitochondrial swelling, and both H2O2 release and swelling were abolished by cyclosporine A, a desensitizer of the mitochondrial permeability transition pore (mPTP). These results indicate that ROS production by complex I and by complex III is differently affected by buffer pH and Ca2+ loading with mPTP opening. The study suggests that changes in the levels of cytosolic Ca2+ and pH during IR alter the relative amounts of ROS produced at mitochondrial respiratory complex I and complex III. PMID

  12. Particulate matter phagocytosis induces tissue factor in differentiating macrophages.

    PubMed

    Milano, M; Dongiovanni, P; Artoni, A; Gatti, S; Rosso, L; Colombo, F; Bollati, V; Maggioni, M; Mannucci, P M; Bertazzi, P A; Fargion, S; Valenti, L

    2016-01-01

    Airborne exposure to particulate matter with diameter < 10 mcM (PM10) has been linked to an increased risk of thromboembolic events, but the mechanisms are not completely understood. The aim of this study was to evaluate the effect of PM10 phagocytosis on the release of procoagulant molecules in human differentiating macrophages, and that of PM10 inhalation in an experimental model in rats. Human monocytes were separated from the peripheral blood by the lymphoprep method, differentiated in vitro and treated with standard PM10 or vehicle. Sprague-Dawley rats were instilled intratracheally with PM10 or vehicle alone. The outcome was expression of proinflammatory genes and of tissue factor (TF). In human differentiating macrophages, PM10 exposure upregulated inflammatory genes, but most consistently induced TF mRNA and protein levels, but not TF protein inhibitor, resulting in increased TF membrane expression and a procoagulant phenotype. Differentiation towards the anti-inflammatory M2 phenotype inhibited PM10 -mediated TF expression. TF induction required phagocytosis of PM10 , whereas phagocytosis of inert particles was less effective. PM10 phagocytosis was associated with a gene expression profile consistent with intracellular retention of iron, inducing oxidative stress. Both PM10 and iron activated the stress kinases ERK1/2 pathway, involved in the induction of TF expression. In rats, alveolar exposure to PM10 was associated with pulmonary recruitment of inflammatory cells and resulted in local, but not systemic, induction of TF expression, which was sufficient to increase circulating TF levels. In conclusion, TF induction by differentiating lung macrophages, activated following phagocytosis, contributes to the increased risk of thromboembolic complications associated with PM10 exposure.

  13. Single Low-Dose Radiation Induced Regulation of Keratinocyte Differentiation in Calcium-Induced HaCaT Cells

    PubMed Central

    Hahn, Hyung Jin; Youn, Hae Jeong; Cha, Hwa Jun; Kim, Karam; An, Sungkwan

    2016-01-01

    Background We are continually exposed to low-dose radiation (LDR) in the range 0.1 Gy from natural sources, medical devices, nuclear energy plants, and other industrial sources of ionizing radiation. There are three models for the biological mechanism of LDR: the linear no-threshold model, the hormetic model, and the threshold model. Objective We used keratinocytes as a model system to investigate the molecular genetic effects of LDR on epidermal cell differentiation. Methods To identify keratinocyte differentiation, we performed western blots using a specific antibody for involucrin, which is a precursor protein of the keratinocyte cornified envelope and a marker for keratinocyte terminal differentiation. We also performed quantitative polymerase chain reaction. We examined whether LDR induces changes in involucrin messenger RNA (mRNA) and protein levels in calcium-induced keratinocyte differentiation. Results Exposure of HaCaT cells to LDR (0.1 Gy) induced p21 expression. p21 is a key regulator that induces growth arrest and represses stemness, which accelerates keratinocyte differentiation. We correlated involucrin expression with keratinocyte differentiation, and examined the effects of LDR on involucrin levels and keratinocyte development. LDR significantly increased involucrin mRNA and protein levels during calcium-induced keratinocyte differentiation. Conclusion These studies provide new evidence for the biological role of LDR, and identify the potential to utilize LDR to regulate or induce keratinocyte differentiation. PMID:27489424

  14. Differential expression analysis of genes involved in high-temperature induced sex differentiation in Nile tilapia.

    PubMed

    Li, Chun Ge; Wang, Hui; Chen, Hong Ju; Zhao, Yan; Fu, Pei Sheng; Ji, Xiang Shan

    2014-01-01

    Nowadays, high temperature effects on the molecular pathways during sex differentiation in teleosts need to be deciphered. In this study, a systematic differential expression analysis of genes involved in high temperature-induced sex differentiation was done in the Nile tilapia gonad and brain. Our results showed that high temperature caused significant down-regulation of CYP19A1A in the gonad of both sexes in induction group, and FOXL2 in the ovary of the induction group. The expressions of GTHα, LHβ and ERα were also significantly down-regulated in the brain of both sexes in the induction and recovery groups. On the contrary, the expression of CYP11B2 was significantly up-regulated in the ovary, but not in the testis in both groups. Spearman rank correlation analysis showed that there are significant correlations between the expressions of CYP19A1A, FOXL2, or DMRT1 in the gonads and the expression of some genes in the brain. Another result in this study showed that high temperature up-regulated the expression level of DNMT1 in the testis of the induction group, and DNMT1 and DNMT3A in the female brain of both groups. The expression and correlation analysis of HSPs showed that high temperature action on tilapia HSPs might indirectly induce the expression changes of sex differentiation genes in the gonads. These findings provide new insights on TSD and suggest that sex differentiation related genes, heat shock proteins, and DNA methylation genes are new candidates for studying TSD in fish species.

  15. Polar/apolar compounds induce leukemia cell differentiation by modulating cell-surface potential.

    PubMed Central

    Arcangeli, A; Carlà, M; Del Bene, M R; Becchetti, A; Wanke, E; Olivotto, M

    1993-01-01

    The mechanism of action of polar/apolar inducers of cell differentiation, such as dimethyl sulfoxide and hexamethylene-bisacetamide, is still obscure. In this paper evidence is provided that their effects on murine erythroleukemia cells are modulated by various extracellular cations as a precise function of the cation effects on membrane surface potential. The interfacial effects of the inducers were directly measured on the charged electrode, showing that both dimethyl sulfoxide and hexamethylene-bisacetamide, at the effective concentrations for cell differentiation and within the physiological range of charge density, adsorb at the charged surface and produce a potential shift. A linear correlation was found between this shift and the inducer effects on cell differentiation. Besides offering a different interpretation of the mechanism of action of the inducers, these findings indicate that surface potential has a signaling function. They may also be relevant to cancer treatments based on tumor-cell commitment to terminal differentiation. Images Fig. 1 PMID:8516337

  16. Differential toxicological effects induced by mercury in gills from three pedigrees of Manila clam Ruditapes philippinarum by NMR-based metabolomics.

    PubMed

    Liu, Xiaoli; Zhang, Linbao; You, Liping; Yu, Junbao; Zhao, Jianmin; Li, Lianzhen; Wang, Qing; Li, Fei; Li, Chenghua; Liu, Dongyan; Wu, Huifeng

    2011-01-01

    Mercury is a hazardous pollutant in the Bohai marine environments due to its high toxicity to the marine organisms and subsequent ecological risk. Manila clam Ruditapes philippinarum is one of important sentinel organisms in 'Mussel Watch Program' launched in China and therefore used as a bioindicator in marine and coastal ecotoxicology. There are dominantly distributed three pedigrees of clam (White, Liangdao Red and Zebra) in Yantai population endowed with different tolerances to environmental stressors. In this study, gill tissues were collected from both untreated and mercury exposed White, Liangdao Red and Zebra clams, and the extracts were analyzed by NMR-based metabolomics to compare the original metabolomes and the toxicological effects induced by mercury exposure in three pedigrees. The major abundant metabolites in White clam sample were branched-chain amino acids, lactate, alanine, arginine, acetoacetate, glutamate, succinate, citrate, malonate and taurine, while the metabolite profile of Liangdao Red clam sample comprises relative high levels of alanine, arginine, glutamate, succinate and glycogen. For Zebra clam sample, the metabolite profile exhibited relatively high amount of aspartate, acetylcholine and homarine. After 48 h exposure of 20 μg l(-1) Hg(2+), the metabolic profiles from all the three pedigrees of clams commonly showed significant increases in alanine, arginine, glutamate, aspartate, α-ketoglutarate, glycine and ATP/ADP, and decreases in citrate, taurine and homarine. The unique metabolic differences between the metabolomes of gill tissues from Hg(2+)-exposed White, Liangdao Red and Zebra clams were found, including elevated acetylcholine and branched-chain amino acids in White clams, and the declined succinate in both White and Liangdao Red samples as well as the declined betaine in Zebra and White clams. Overall, our findings showed the differential toxicological responses to mercury exposure and that White clams could be a

  17. Clozapine modifies the differentiation program of human adipocytes inducing browning

    PubMed Central

    Kristóf, E; Doan-Xuan, Q-M; Sárvári, A K; Klusóczki, Á; Fischer-Posovszky, P; Wabitsch, M; Bacso, Z; Bai, P; Balajthy, Z; Fésüs, L

    2016-01-01

    Administration of second-generation antipsychotic drugs (SGAs) often leads to weight gain and consequent cardio-metabolic side effects. We observed that clozapine but not six other antipsychotic drugs reprogrammed the gene expression pattern of differentiating human adipocytes ex vivo, leading to an elevated expression of the browning marker gene UCP1, more and smaller lipid droplets and more mitochondrial DNA than in the untreated white adipocytes. Laser scanning cytometry showed that up to 40% of the differentiating single primary and Simpson–Golabi–Behmel syndrome (SGBS) adipocytes had the characteristic morphological features of browning cells. Furthermore, clozapine significantly upregulated ELOVL3, CIDEA, CYC1, PGC1A and TBX1 genes but not ZIC1 suggesting induction of the beige-like and not the classical brown phenotype. When we tested whether browning induced by clozapine can be explained by its known pharmacological effect of antagonizing serotonin (5HT) receptors, it was found that browning cells expressed 5HT receptors 2A, 1D, 7 and the upregulation of browning markers was diminished in the presence of exogenous 5HT. Undifferentiated progenitors or completely differentiated beige or white adipocytes did not respond to clozapine administration. The clozapine-induced beige cells displayed increased basal and oligomycin-inhibited (proton leak) oxygen consumption, but these cells showed a lower response to cAMP stimulus as compared with control beige adipocytes indicating that they are less capable to respond to natural thermogenic anti-obesity cues. Our data altogether suggest that novel pharmacological stimulation of these masked beige adipocytes can be a future therapeutic target for the treatment of SGA-induced weight gain. PMID:27898069

  18. Antimutagenic; differentiation-inducing; and antioxidative effects of fragrant ingredients in Katsura-uri (Japanese pickling melon; Cucumis melo var. conomon).

    PubMed

    Nakamura, Yasushi; Watanabe, Shinpei; Kageyama, Minami; Shirota, Keiko; Shirota, Koji; Amano, Hisashi; Kashimoto, Tadahiro; Matsuo, Tomoaki; Okamoto, Shigehisa; Park, Eun Young; Sato, Kenji

    2010-12-21

    Six fragrant ingredients were identified in fully-ripened Katsura-uri (Japanese pickling melon; Cucumis melo var. conomon). Four of them were sulfur-containing compounds [methylthioacetic acid ethyl ester (MTAE), acetic acid 2-methylthio ethyl ester (AMTE), 3-methylthiopropionic acid ethyl ester (MTPE), and acetic acid 3-methylthio propyl ester (AMTP)]; and the others were benzyl acetate and eugenol. The newly identified MTAE and AMTP possessed antimutagenic activity as determined by their ability to inhibit the UV-induced mutation in repair-proficient E. coli B/r WP2. MTAE and MTPE (esters with thiocarbonic acid and alkyl alcohol) induced the differentiation of human colon cancer cells (RCM-1 cells), but AMTE and AMTP (esters with carbonic acid and thioalkyl alcohol) did not. A specific thioester motif containing a thiocarbonic acid and alkyl alcohol correlated with these compounds ability to induce differentiation. AMTE, MTPE, AMTP, and eugenol had higher oxygen radical absorbing capacity than the antioxidative vitamin, ascorbic acid. The quantity of MTPE, AMTP and eugenol increased 49-fold, >1175-fold and 11-fold, respectively, in the fully-ripened fruit as compared to the mid-ripened fruit.

  19. Neuroprotective effects of dimerumic acid and deferricoprogen from Monascus purpureus NTU 568-fermented rice against 6-hydroxydopamine-induced oxidative stress and apoptosis in differentiated pheochromocytoma PC-12 cells.

    PubMed

    Tseng, Wei-Ting; Hsu, Ya-Wen; Pan, Tzu-Ming

    2016-08-01

    Context Oxidative stress plays a key role in neurodegenerative disorders, including Parkinson's disease (PD). Rice fermented with Monascus purpureus Went (Monascaceae) NTU 568 (red mould rice) was found to contain antioxidants, including dimerumic acid (DMA) and deferricoprogen (DFC). Objective The effects of DMA and DFC on 6-hydroxydopamine (6-OHDA)-induced cytotoxicity and potential protective mechanisms in differentiated PC-12 pheochromocytoma cells were investigated. Materials and methods DMA (0-60 μM) or DFC (0-10 μM) was co-treated with 6-OHDA (200 μM, 24 h exposure) in differentiated PC-12 cells. Cell viability and intercellular reactive oxygen species (ROS) were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and 2',7'-dichlorofluorescein-diacetate (DCFH-DA) assays, respectively. Cell apoptosis was determined by DNA fragmentation analysis and propidium iodide staining by flow cytometry. Western blot analysis was used to measure the levels of cell protein expression. Results DMA and DFC significantly increased cell viability to 72% and 81% in 6-OHDA-induced differentiated PC-12 cell cultures, respectively. Furthermore, DMA and DFC reduced 6-OHDA-induced formation of extracellular and intercellular ROS by 25% and 20%, respectively, and decreased NADPH oxidase-2 expression in differentiated PC-12 cells. DMA and DFC inhibited 6-OHDA-induced apoptosis and decreased activation of caspase-3 via regulation of Bcl-2-associated X protein (Bax) and Bcl-2 protein expression in differentiated PC-12 cells. Conclusion DMA and DFC may protect against 6-OHDA toxicity by inhibiting ROS formation and apoptosis. These results showed that the metabolites from M. purpureus NTU 568 fermentation were potential therapeutic agents for PD induced by oxidative damage and should be encouraged for further research.

  20. Effect of Yi Guan Jian decoction on differentiation of bone marrow mesenchymalstem cells into hepatocyte-like cells in dimethylnitrosamine-induced liver cirrhosis in mice.

    PubMed

    Xiang, Yan; Pang, Bing-Yao; Zhang, Yuan; Xie, Qiao-Ling; Zhu, Ying; Leng, Ai-Jing; Lu, Long-Qing; Chen, Hai-Long

    2017-02-01

    Yi Guan Jian decoction (YGD) may induce the differentiation of bone marrow mesenchymal stem cells (BMSCs) into hepatocyte-like cells (HLCs); however, the underlying mechanisms remain to be elucidated. The present study aimed to investigate this process. To do this, a dimethylnitrosamine (DMN)-induced liver cirrhosis mouse model was established. The mice from the model group were randomly divided into three subgroups: i) Negative control, ii) hepatocyte growth factor and iii) YGD. The overall health, liver function and histological alterations were monitored. The expression of α‑smooth muscle actin (α‑SMA), C‑X‑C chemokine receptor type 4 (CXCR4), extracellular signal‑regulated kinase (ERK1/2), nuclear factor κB p65 subunit (NF‑κB p65) and β‑catenin were measured by immunohistochemistry, western blotting and reverse transcription‑quantitative polymerase chain reaction. Following administration of DMN, the overall health of the mice significantly decreased, with an increase in pathological developments and liver damage resulting in a decrease in liver function. Immunohistochemistry revealed that the expression of α‑SMA, CXCR4, ERK1/2, NF‑κB p65 and β‑catenin was upregulated. Following treatment with YGD, the overall health, liver function and pathology improved. The mRNA and protein expression levels of CXCR4 and ERK1/2 were upregulated, where as α‑SMA, NF‑κB p65 and β‑catenin levels were downregulated. The results demonstrated that YGD may induce the differentiation of BMSCs into HLCs to reverse DMN‑induced liver cirrhosis; this may be achieved via an upregulation of the SDF‑1/CXCR4 axis to activate the mitogen activated protein kinase/ERK1/2 signaling pathway.

  1. Sodium hydrogen sulfide inhibits nicotine and lipopolysaccharide-induced osteoclastic differentiation and reversed osteoblastic differentiation in human periodontal ligament cells.

    PubMed

    Lee, Sun-Kyung; Chung, Jong-Hyuk; Choi, Sung-Chul; Auh, Q-Schick; Lee, Young-Man; Lee, Sang-Im; Kim, Eun-Cheol

    2013-05-01

    Although previous studies have demonstrated that hydrogen sulfide (H(2)S) stimulated or inhibited osteoclastic differentiation, little is known about the effects of H(2)S on the differentiation of osteoblasts and osteoclasts. To determine the possible bioactivities of H(2)S on bone metabolism, we investigated the in vitro effects of H(2)S on cytotoxicity, osteoblastic, and osteoclastic differentiation as well as the underlying mechanism in lipopolysaccharide (LPS) and nicotine-stimulated human periodontal ligament cells (hPDLCs). The H(2)S donor, NaHS, protected hPDLCs from nicotine and LPS-induced cytotoxicity and recovered nicotine- and LPS-downregulated osteoblastic differentiation, such as alkaline phosphatase (ALP) activity, mRNA expression of osteoblasts, including ALP, osteopontin (OPN), and osteocalcin (OCN), and mineralized nodule formation. Concomitantly, NaHS inhibited the differentiation of tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts in mouse bone marrow cells and blocked nicotine- and LPS-induced osteoclastogenesis regulatory molecules, such as RANKL, OPG, M-CSF, MMP-9, TRAP, and cathepsin K mRNA. NaHS blocked nicotine and LPS-induced activation of p38, ERK, MKP-1, PI3K, PKC, and PKC isoenzymes, and NF-κB. The effects of H(2)S on nicotine- and LPS-induced osteoblastic and osteoclastic differentiation were remarkably reversed by MKP-1 enzyme inhibitor (vanadate) and expression inhibitor (triptolide). Taken together, we report for the first time that H(2)S inhibited cytotoxicity and osteoclastic differentiation and recovered osteoblastic differentiation in a nicotine- and periodontopathogen-stimulated hPDLCs model, which has potential therapeutic value for treatment of periodontal and inflammatory bone diseases.

  2. Analysis of Differentially Expressed Genes Associated with Coronatine-Induced Laticifer Differentiation in the Rubber Tree by Subtractive Hybridization Suppression.

    PubMed

    Zhang, Shi-Xin; Wu, Shao-Hua; Chen, Yue-Yi; Tian, Wei-Min

    2015-01-01

    The secondary laticifer in the secondary phloem is differentiated from the vascular cambia of the rubber tree (Hevea brasiliensis Muell. Arg.). The number of secondary laticifers is closely related to the rubber yield potential of Hevea. Pharmacological data show that jasmonic acid and its precursor linolenic acid are effective in inducing secondary laticifer differentiation in epicormic shoots of the rubber tree. In the present study, an experimental system of coronatine-induced laticifer differentiation was developed to perform SSH identification of genes with differential expression. A total of 528 positive clones were obtained by blue-white screening, of which 248 clones came from the forward SSH library while 280 clones came from the reverse SSH library. Approximately 215 of the 248 clones and 171 of the 280 clones contained cDNA inserts by colony PCR screening. A total of 286 of the 386 ESTs were detected to be differentially expressed by reverse northern blot and sequenced. Approximately 147 unigenes with an average length of 497 bp from the forward and 109 unigenes with an average length of 514 bp from the reverse SSH libraries were assembled and annotated. The unigenes were associated with the stress/defense response, plant hormone signal transduction and structure development. It is suggested that Ca2+ signal transduction and redox seem to be involved in differentiation, while PGA and EIF are associated with the division of cambium initials for COR-induced secondary laticifer differentiation in the rubber tree.

  3. The effect of combined regulation of the expression of peroxisome proliferator-activated receptor-γ and calcitonin gene-related peptide on alcohol-induced adipogenic differentiation of bone marrow mesenchymal stem cells.

    PubMed

    Li, Jinfeng; Wang, Yisheng; Li, Yuebai; Sun, Junkui; Zhao, Guoqiang

    2014-07-01

    Studies have shown that alcohol can upregulate the expression of peroxisome proliferator-activated receptor-γ (PPARγ) gene in bone marrow mesenchymal stem cells (BMSCs). High expression of PPARγ can promote adipogenic differentiation of BMSCs, and reduce their osteogenic differentiation. Abnormal proliferation of adipocytes and fatty accumulation in osteocytes can result in high intraosseous pressure and disturbance of blood circulation in the femoral head, which induces osteonecrosis of the femoral head (ONFH). Downregulation of PPARγ is efficient in inhibiting adipogenesis and maintaining osteogenesis of BMSCs, which might potentially reduce the incidence of ONFH. Calcitonin gene-related peptide (CGRP) is a neuropeptide gene which has been closely associated with bone regeneration. In this study, we aimed to observe the effect of combined regulation of the expression of PPARγ and CGRP genes on alcohol-induced adipogenic differentiation of BMSCs. Our results demonstrated that simultaneous downregulation of PPARγ and upregulation of CGRP was efficient in suppressing adipogenic differentiation of BMSCs and promoting their osteogenic differentiation. These findings might enlighten a novel approach for the prevention of ONFH.

  4. Identification of H7 as a novel peroxiredoxin I inhibitor to induce differentiation of leukemia cells

    PubMed Central

    Qin, Dongjun; Chen, Yingyi; Liu, Chuanxu; Xia, Li; Wang, Tongdan; Lei, Hu; Yu, Yun; Huang, Min; Tong, Yin; Xu, Hanzhang; Gao, Fenghou

    2016-01-01

    Identifying novel targets to enhance leukemia-cell differentiation is an urgent requirment. We have recently proposed that inhibiting the antioxidant enzyme peroxiredoxin I (Prdx I) may induce leukemia-cell differentiation. However, this concept remains to be confirmed. In this work, we identified H7 as a novel Prdx I inhibitor through virtual screening, in vitro activity assay, and surface plasmon resonance assay. Cellular thermal shift assay showed that H7 directly bound to Prdx I but not to Prdxs II–V in cells. H7 treatment also increased reactive oxygen species (ROS) level and cell differentiation in leukemia cells, as reflected by the upregulation of the cell surface differentiation marker CD11b/CD14 and the morphological maturation of cells. The differentiation-induction effect of H7 was further observed in some non-acute promyelocytic leukemia (APL) and primary leukemia cells apart from APL NB4 cells. Moreover, the ROS scavenger N-acetyl cysteine significantly reversed the H7-induced cell differentiation. We demonstrated as well that H7-induced cell differentiation was associated with the activation of the ROS-Erk1/2-C/EBPβ axis. Finally, we showed H7 treatment induced cell differentiation in an APL mouse model. All of these data confirmed that Prdx I was novel target for inducing leukemia-cell differentiation and that H7 was a novel lead compound for optimizing Prdx I inhibition. PMID:26716647

  5. Protein palmitoylation regulates osteoblast differentiation through BMP-induced osterix expression.

    PubMed

    Leong, Wai Fook; Zhou, Tielin; Lim, Gek Liang; Li, Baojie

    2009-01-01

    Osteoporosis is one of the most common diseases and can be treated by either anti-resorption drugs, anabolic drugs, or both. To search for anabolic drug targets for osteoporosis therapy, it is crucial to understand the biology of bone forming cells, osteoblasts, in terms of their proliferation, differentiation, and function. Here we found that protein palmitoylation participates in signaling pathways that control osterix expression and osteoblast differentiation. Mouse calvarial osteoblasts express most of the 24 palmitoyl transferases, with some being up-regulated during differentiation. Inhibition of protein palmitoylation, with a substrate-analog inhibitor, diminished osteoblast differentiation and mineralization, but not proliferation or survival. The decrease in differentiation capacity is associated with a reduction in osterix, but not Runx2 or Atf4. Inhibition of palmitoyl transferases had little effect in p53(-/-) osteoblasts that show accelerated differentiation due to overexpression of osterix, suggesting that osterix, at least partially, mediated the effect of inhibition of palmitoyl transferases on osteoblast differentiation. BMPs are the major driving force of osteoblast differentiation in the differentiation assays. We found that inhibition of palmitoyl transferases also compromised BMP2-induced osteoblast differentiation through down-regulating osterix induction. However, palmitoyl transferases inhibitor did not inhibit Smad1/5/8 activation. Instead, it compromised the activation of p38 MAPK, which are known positive regulators of osterix expression and differentiation. These results indicate that protein palmitoylation plays an important role in BMP-induced MAPK activation, osterix expression, and osteoblast differentiation.

  6. Hypoxia-inducible factor-1alpha blocks differentiation of malignant gliomas.

    PubMed

    Lu, Huimin; Li, Yan; Shu, Minfeng; Tang, Jianjun; Huang, Yijun; Zhou, Yuxi; Liang, Yingjie; Yan, Guangmei

    2009-12-01

    Aberrant differentiation is a characteristic feature of neoplastic transformation, while hypoxia in solid tumors is believed to be linked to aggressive behavior and poor prognosis. However, the possible relationship between hypoxia and differentiation in malignancies remains poorly defined. Here we show that rat C6 and primary human malignant glioma cells can be induced to differentiate into astrocytes by the well-known adenylate cyclase activator forskolin. However, hypoxia-inducible factor-1alpha expression stimulated by the hypoxia mimetics cobalt chloride or deferoxamine blocks this differentiation and this effectiveness is reversible upon withdrawal of the hypoxia mimetics. Importantly, knockdown of hypoxia inducible factor-1alpha by RNA interference restores the differentiation capabilities of the cells, even in the presence of cobalt chloride, whereas stabilization of hypoxia-inducible factor-1alpha through retarded ubiquitination by von Hippel-Lindau tumor suppressor gene silence abrogates the induced differentiation. Moreover, targeting of HIF-1 using chetomin, a disrupter of HIF-1 binding to its transcriptional co-activator CREB-binding protein (CBP)/p300, abolishes the differentiation-inhibitory effect of hypoxia-inducible factor-1alpha. Administration of chetomin in combination with forskolin significantly suppresses malignant glioma growth in an in vivo xenograft model. Analysis of 95 human glioma tissues revealed an increase of hypoxia-inducible factor-1alpha protein expression with progressing tumor grade. Taken together, these findings suggest a key signal transduction pathway involving hypoxia-inducible factor-1alpha that contributes to a differentiation defect in malignant gliomas and sheds new light on the differentiation therapy of solid tumors by targeting hypoxia-inducible factor-1alpha.

  7. BMP2 induces chondrogenic differentiation, osteogenic differentiation and endochondral ossification in stem cells.

    PubMed

    Zhou, Nian; Li, Qi; Lin, Xin; Hu, Ning; Liao, Jun-Yi; Lin, Liang-Bo; Zhao, Chen; Hu, Zhen-Ming; Liang, Xi; Xu, Wei; Chen, Hong; Huang, Wei

    2016-10-01

    Bone morphogenetic protein 2 (BMP2), a member of the transforming growth factor-β (TGF-β) super-family, is one of the main chondrogenic growth factors involved in cartilage regeneration. BMP2 is known to induce chondrogenic differentiation in various types of stem cells in vitro. However, BMP2 also induces osteogenic differentiation and endochondral ossification in mesenchymal stem cells (MSCs). Although information regarding BMP2-induced chondrogenic and osteogenic differentiation within the same system might be essential for cartilage tissue engineering, few studies concerning these issues have been conducted. In this study, BMP2 was identified as a regulator of chondrogenic differentiation, osteogenic differentiation and endochondral bone formation within the same system. BMP2 was used to regulate chondrogenic and osteogenic differentiation in stem cells within the same culture system in vitro and in vivo. Any changes in the differentiation markers were assessed. BMP2 was found to induce chondrogenesis and osteogenesis in vitro via the expression of Sox9, Runx2 and its downstream markers. According to the results of the subcutaneous stem cell implantation studies, BMP2 not only induced cartilage formation but also promoted endochondral ossification during ectopic bone/cartilage formation. In fetal limb cultures, BMP2 promoted chondrocyte hypertrophy and endochondral ossification. Our data reveal that BMP2 can spontaneously induce chondrogenic differentiation, osteogenic differentiation and endochondral bone formation within the same system. Thus, BMP2 can be used in cartilage tissue engineering to regulate cartilage formation but has to be properly regulated for cartilage tissue engineering in order to retain the cartilage phenotype.

  8. Dextran induces differentiation of circulating endothelial progenitor cells

    PubMed Central

    Obi, Syotaro; Masuda, Haruchika; Akimaru, Hiroshi; Shizuno, Tomoko; Yamamoto, Kimiko; Ando, Joji; Asahara, Takayuki

    2014-01-01

    Abstract Endothelial progenitor cells (EPCs) have been demonstrated to be effective for the treatment of cardiovascular diseases. However, the differentiation process from circulation to adhesion has not been clarified because circulating EPCs rarely attached to dishes in EPC cultures previously. Here we investigated whether immature circulating EPCs differentiate into mature adhesive EPCs in response to dextran. When floating‐circulating EPCs derived from ex vivo expanded human cord blood were cultured with 5% and 10% dextran, they attached to fibronectin‐coated dishes and grew exponentially. The bioactivities of adhesion, proliferation, migration, tube formation, and differentiated type of EPC colony formation increased in EPCs exposed to dextran. The surface protein expression rate of the endothelial markers vascular endothelial growth factor (VEGF)‐R1/2, VE‐cadherin, Tie2, ICAM1, VCAM1, and integrin αv/β3 increased in EPCs exposed to dextran. The mRNA levels of VEGF‐R1/2, VE‐cadherin, Tie2, endothelial nitric oxide synthase, MMP9, and VEGF increased in EPCs treated with dextran. Those of endothelium‐related transcription factors ID1/2, FOXM1, HEY1, SMAD1, FOSL1, NFkB1, NRF2, HIF1A, EPAS1 increased in dextran‐treated EPCs; however, those of hematopoietic‐ and antiangiogenic‐related transcription factors TAL1, RUNX1, c‐MYB, GATA1/2, ERG, FOXH1, HHEX, SMAD2/3 decreased in dextran‐exposed EPCs. Inhibitor analysis showed that PI3K/Akt, ERK1/2, JNK, and p38 signal transduction pathways are involved in the differentiation in response to dextran. In conclusion, dextran induces differentiation of circulating EPCs in terms of adhesion, migration, proliferation, and vasculogenesis. The differentiation mechanism in response to dextran is regulated by multiple signal transductions including PI3K/Akt, ERK1/2, JNK, and p38. These findings indicate that dextran is an effective treatment for EPCs in regenerative medicines. PMID:24760515

  9. Differential effect of cyclo-oxygenase inhibition on antigen- and ionophore-induced release of slow reacting substance from fragmented guinea-pig lung.

    PubMed Central

    Krell, R. D.; Kusner, E. J.

    1984-01-01

    The nonsteroidal anti-inflammatory drugs (NSAID) indomethacin and mefenamic acid, at concentrations ranging from 3 microM to 18 microM, enhanced antigen-induced slow reacting substance of anaphylaxis (SRS-A) release from sensitized fragmented guinea-pig lung. In contrast, these agents had no effect on SRS-A release from nonsensitized guinea-pig lung induced by several concentrations of the calcium ionophore, A23187. Neither increasing preincubation time with the NSAID nor the use of sensitized tissue resulted in an enhancement of A23187-induced SRS-A release by indomethacin. NSAID did not alter histamine release by either stimulus. These results suggest that antigen and A23187 induce SRS-A release from different sources or by different mechanisms in guinea-pig lung. PMID:6434013

  10. Methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA) and 3,4-methylenedioxypyrovalerone (MDPV) induce differential cytotoxic effects in bovine brain microvessel endothelial cells.

    PubMed

    Rosas-Hernandez, Hector; Cuevas, Elvis; Lantz, Susan M; Rice, Kenner C; Gannon, Brenda M; Fantegrossi, William E; Gonzalez, Carmen; Paule, Merle G; Ali, Syed F

    2016-08-26

    Designer drugs such as synthetic psychostimulants are indicative of a worldwide problem of drug abuse and addiction. In addition to methamphetamine (METH), these drugs include 3,4-methylenedioxy-methamphetamine (MDMA) and commercial preparations of synthetic cathinones including 3,4-methylenedioxypyrovalerone (MDPV), typically referred to as "bath salts." These psychostimulants exert neurotoxic effects by altering monoamine systems in the brain. Additionally, METH and MDMA adversely affect the integrity of the blood-brain barrier (BBB): there are no current reports on the effects of MDPV on the BBB. The aim of this study was to compare the effects of METH, MDMA and MDPV on bovine brain microvessel endothelial cells (bBMVECs), an accepted in vitro model of the BBB. Confluent bBMVEC monolayers were treated with METH, MDMA and MDPV (0.5mM-2.5mM) for 24h. METH and MDMA increased lactate dehydrogenase release only at the highest concentration (2.5mM), whereas MDPV induced cytotoxicity at all concentrations. MDMA and METH decreased cellular proliferation only at 2.5mM, with similar effects observed after MDPV exposures starting at 1mM. Only MDPV increased reactive oxygen species production at all concentrations tested whereas all 3 drugs increased nitric oxide production. Morphological analysis revealed different patterns of compound-induced cell damage. METH induced vacuole formation at 1mM and disruption of the monolayer at 2.5mM. MDMA induced disruption of the endothelial monolayer from 1mM without vacuolization. On the other hand, MDPV induced monolayer disruption at doses ≥0.5mM without vacuole formation; at 2.5mM, the few remaining cells lacked endothelial morphology. These data suggest that even though these synthetic psychostimulants alter monoaminergic systems, they each induce BBB toxicity by different mechanisms with MDPV being the most toxic.

  11. Statins induce differentiation and cell death in neurons and astroglia.

    PubMed

    März, Pia; Otten, Uwe; Miserez, André R

    2007-01-01

    Statins are potent inhibitors of the hydroxy-methyl-glutaryl-coenzyme A reductase, the rate limiting enzyme for cholesterol biosynthesis. Experimental and clinical studies with statins suggest that they have beneficial effects on neurodegenerative disorders. Thus, it was of interest to characterize the direct effects of statins on CNS neurons and glial cells. We have treated defined cultures of neurons and astrocytes of newborn rats with two lipophilic statins, atorvastatin and simvastatin, and analyzed their effects on morphology and survival. Treatment of astrocytes with statins induced a time- and dose-dependent stellation, followed by apoptosis. Similarly, statins elicited programmed cell death of cerebellar granule neurons but with a higher sensitivity. Analysis of different signaling cascades revealed that statins fail to influence classical pathways such as Akt or MAP kinases, known to be activated in CNS cells. In addition, astrocyte stellation triggered by statins resembled dibutryl-cyclic AMP (db-cAMP) induced morphological differentiation. However, in contrast to db-cAMP, statins induced upregulation of low-density lipoprotein receptors, without affecting GFAP expression, indicating separate underlying mechanisms. Analysis of the cholesterol biosynthetic pathway revealed that lack of mevalonate and of its downstream metabolites, mainly geranylgeranyl-pyrophosphate (GGPP), is responsible for the statin-induced apoptosis of neurons and astrocytes. Moreover, astrocytic stellation triggered by statins was inhibited by mevalonate and GGPP. Interestingly, neuronal cell death was significantly reduced in astrocyte/neuron co-cultures treated with statins. We postulate that under these conditions signals provided by astrocytes, e.g., isoprenoids play a key role in neuronal survival.

  12. Chemically induced bidirectional differentiation of embryonal carcinoma cells in vitro.

    PubMed Central

    Speers, W. C.; Birdwell, C. R.; Dixon, F. J.

    1979-01-01

    N,N-dimethylacetamide, hexamethylene bisacetamide, and Polybrene induced rapid and extensive differentiation in vitro in an otherwise slowly differentiating subline of embryonal carcinoma cells. The type of differentiated cell induced was dependent on the spatial organization of the stem cells during drug treatment. In monalayer culture "epithelial" cells were produced exclusively. However, treatment of aggregated suspension cultures yielded predominantly "fibroblast-like" cells. The undifferentiated embryonal carcinoma cells and the two differentiated cell types were morphologically distinct when examined by light microscopy, scanning electron microscopy, and transmission electron microscopy; and they had differences in cell surface antigens. Both differential cell types produced large amounts of fibronectin, whereas the embryonal carcinoma cells produced only minimal amounts. This system provides a convenient way to induce relatively synchronous differentiation of embryonal carcinoma cells into specific differentiated cell types. Images Figure 5 Figure 6 Figure 1 Figure 2 Figure 3 Figure 4 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 PMID:507191

  13. A label-free, impedance-based real time assay to identify drug-induced toxicities and differentiate cytostatic from cytotoxic effects.

    PubMed

    Kustermann, S; Boess, F; Buness, A; Schmitz, M; Watzele, M; Weiser, T; Singer, T; Suter, L; Roth, A

    2013-08-01

    Cell-based assays are key tools in drug safety assessment. However, they usually provide only limited information about time-kinetics of a toxic effect and implementing multiple measurements is often complex. To overcome these issues we established an impedance-based approach which is able to differentiate cytostatic from cytotoxic drugs by recording time-kinetics of compound-effects on cells. NIH 3T3 fibroblasts were seeded on xCELLigence® E-plates and impedance was continuously measured over 5 days. The obtained results reflected cytotoxicity and cell proliferation, as confirmed by neutral red uptake in vitro. Based on known toxicants, we established an algorithm able to discriminate cytostatic, cytotoxic and non-toxic compounds based on the shape of the impedance curves. Analyzing impedance curve patterns of additional 37 compounds allowed the identification and differentiation of these distinct effects as results correlated well with previous in vivo findings. We show that impedance-based real-time cell analysis is a convenient tool to characterize and discriminate effects of compounds on cells in a time-dependent and label-free manner. The presented impedance assay could be used to further characterize toxicities observed in vivo or in vitro. Due to the ease of performance it may also be a suitable screening tool.

  14. Differential Effects of Kupffer Cell Inactivation on Inflammation and The Liver Sieve Following Caecal-Ligation and Puncture-Induced Sepsis in Mice.

    PubMed

    Gaddam, Ravinder Reddy; Fraser, Robin; Badiei, Alireza; Chambers, Stephen; Cogger, Victoria C; Le Couteur, David G; Bhatia, Madhav

    2017-04-01

    Sepsis remains a common clinical problem with significant mortality. Activation of the Kupffer cells during sepsis is associated with systemic inflammatory response and multiple organ failure. Kupffer cell activation also leads to structural changes in the liver sinusoidal endothelial cells (LSECs) during endotoxemia. However, these effects remain to be elucidated in caecal-ligation and puncture (CLP)-induced polymicrobial sepsis. To investigate the role of Kupffer cells on LSECs fenestrae and inflammation during CLP-induced sepsis, sepsis was induced by CLP and mice were treated with gadolinium chloride (GdCl3) before CLP-induced sepsis, to inactivate Kupffer cells. Mice were sacrificed after 8 h. Blood, liver, and lung tissues were collected and processed to measure LSECs fenestration, myeloperoxidase (MPO) activity, alanine transaminase (ALT) and aspartate aminotransferase (AST) activity, histological examination, and various cytokines/chemokines levels. LSECs fenestrae was studied using scanning electron micrographs of the LSECs. Strikingly, CLP mice treated with GdCl3 were protected against liver injury as evidenced by decreased LSECs defenestration and damage, MPO, ALT and AST activities, liver tissue damage, and inflammatory cytokines TNF-α, IL-6 and IL-1β, and chemokines MCP-1 and MIP-2α. However, CLP mice treated with GdCl3 had no protection against increased lung MPO activity, tissue damage, inflammatory cytokines, and chemokines. Treatment with GdCl3 also had no effect on the systemic inflammatory response as shown by no change in the circulatory inflammatory cytokines and chemokines following CLP-induced sepsis. Collectively, these data suggest that inactivation of Kupffer cells by GdCl3 protects the liver but had no effect on lung injury or inflammation and systemic inflammatory response following CLP-induced sepsis.

  15. Differential Effects of Sodium Butyrate and Lithium Chloride on Rhesus Monkey Trophoblast Differentiation

    PubMed Central

    Kumar, Priyadarsini; Thirkill, Twanda L.; Ji, Jennifer; Monte, Louise H.; Douglas, Gordon C.

    2015-01-01

    Trophoblast differentiation during early placental development is critical for successful pregnancy and aberrant differentiation causes preeclampsia and early pregnancy loss. During the first trimester, cytotrophoblasts are exposed to low oxygen tension (equivalent to~2%-3% O2) and differentiation proceeds along an extravillous pathway (giving rise to invasive extravillous cytotrophoblasts) and a villous pathway (giving rise to multinucleated syncytiotrophoblast). Interstitial extravillous cytotrophoblasts invade the decidua, while endovascular extravillous cytotrophoblasts are involved in re-modelling uterine spiral arteries. We tested the idea that sodium butyrate (an epigenetic modulator) induces trophoblast differentiation in early gestation rhesus monkey trophoblasts through activation of the Wnt/β-catenin pathway. The results show that syncytiotrophoblast formation was increased by butyrate, accompanied by nuclear accumulation of β-catenin, and increased expression of EnvV2 and galectin-1 (two factors thought to be involved in trophoblast fusion). Surprisingly, the expression of GCM1 and syncytin-2 was not affected by sodium butyrate. When trophoblasts were incubated with lithium chloride, a GSK3 inhibitor that mimics Wnt activation, nuclear accumulation of β-catenin also occurred but differentiation into syncytiotrophoblast was not observed. Instead the cells differentiated to mononucleated spindle-shaped cells and showed molecular and behavioral characteristics of endovascular trophoblasts. Another highly specific inhibitor of GSK3, CHIR99021, failed to induce endovascular trophoblast characteristics. These observations suggest that activation of the Wnt/β-catenin pathway correlates with both trophoblast differentiation pathways, but that additional factors determine specific cell fate decisions. Other experiments suggested that the differential effects of sodium butyrate and lithium chloride might be explained by their effects on TNFα production. The

  16. Parathyroid hormone 1-34 reduces dexamethasone-induced terminal differentiation in human articular chondrocytes.

    PubMed

    Chang, Ling-Hua; Wu, Shun-Cheng; Chen, Chung-Hwan; Wang, Gwo-Jaw; Chang, Je-Ken; Ho, Mei-Ling

    2016-08-10

    Intra-articular injection of dexamethasone (Dex) is occasionally used to relieve pain and inflammation in osteoarthritis (OA) patients. Dex induces terminal differentiation of chondrogenic mesenchymal stem cells in vitro and causes impaired longitudinal skeletal growth in vivo. Parathyroid hormone 1-34 (PTH 1-34) has been shown to reverse terminal differentiation of osteoarthritic articular chondrocytes. We hypothesized that Dex induces terminal differentiation of articular chondrocytes and that this effect can be mitigated by PTH 1-34 treatment. We tested the effect of Dex on terminal differentiation in human articular chondrocytes and further tested if PTH 1-34 reverses the effects. We found that Dex treatment downregulated chondrogenic-induced expressions of SOX-9, collagen type IIa1 (Col2a1), and aggrecan and reduced synthesis of cartilaginous matrix (Col2a1 and sulfated glycosaminoglycan) synthesis. Dex treatment upregulated chondrocyte hypertrophic markers of collagen type X and alkaline phosphatase at mRNA and protein levels, and it increased the cell size of articular chondrocytes and induced cell death. These results indicated that Dex induces terminal differentiation of articular chondrocytes. To test whether PTH 1-34 treatment reverses Dex-induced terminal differentiation of articular chondrocytes, PTH 1-34 was co-administered with Dex. Results showed that PTH 1-34 treatment reversed both changes of chondrogenic and hypertrophic markers in chondrocytes induced by Dex. PTH 1-34 also decreased Dex-induced cell death. PTH 1-34 treatment reduces Dex-induced terminal differentiation and apoptosis of articular chondrocytes, and PTH 1-34 treatment may protect articular cartilage from further damage when received Dex administration.

  17. X-radiation-induced differentiation of xenotransplanted human undifferentiated rhabdomyosarcoma

    SciTech Connect

    Takizawa, T.; Matsui, T.; Maeda, Y.; Okabe, S.; Mochizuki, M.; Tanaka, A.; Kawaguchi, K.; Fukayama, M.; Funata, N.; Koike, M.

    1989-01-01

    A serially xenotransplantable strain of undifferentiated embryonal rhabdomyosarcoma originating from the nasal cavity of a 42-year-old woman has been established in our laboratory. After radiotherapy for the tumor donor, distinct rhabdomyoblastic differentiation of the undifferentiated sarcoma cells appeared in the primary lesion, and it is a reasonable assumption that X-irradiation has a certain potentiality to induce morphologic differentiation of tumor cells. To study this possibility, tissue fragments of undifferentiated embryonal rhabdomyosarcoma that had grown to more than 10 mm after being transplanted to nude mice were selectively irradiated in situ. The degree of rhabdomyoblastic differentiation according to radiation dose was evaluated by light and electron microscopy and by immunostainability for myoglobin, creatine phosphokinase-MM, and desmin. Distinct morphologic differentiation of undifferentiated sarcoma cells could be induced by repeated X-irradiations at several-week intervals.

  18. Effect of olanzapine on scopolamine induced deficits in differential reinforcement of low rate 72s (DRL-72s) schedule in rats: involvement of the serotonergic receptors in restoring the deficits.

    PubMed

    Jayarajan, Pradeep; Nirogi, Ramakrishna; Shinde, Anil

    2013-11-15

    Scopolamine, a non-selective muscarinic receptor antagonist has widespread central nervous system effects. Muscarinic receptors located in the central nervous system play a vital role in the modulation of impulsivity. The objective of the current study was to evaluate the effect of scopolamine on impulsivity using differential-reinforcement-of-low-rate 72-s schedule (DRL-72s) and to demonstrate the involvement of serotonergic receptors in mediating the effect of olanzapine (atypical antipsychotic) on scopolamine induced impulsivity. Scopolamine impaired the performance of the rats trained under DRL-72s schedule. Olanzapine reversed the deficits induced by scopolamine. We evaluated the effect of donepezil (cholinesterase inhibitor), SB-742457 (5-HT6 and 5-HT2a antagonist), and haloperidol (typical antipsychotic) in rats challenged with scopolamine in the DRL-72s schedule to identify the receptor(s) involved in reversing the deficits. SB-742457 partially reversed the deficits, but donepezil and haloperidol did not show any effects on the deficits induced by scopolamine. Olanzapine and SB-742457 shifted the peak location (PkL) towards longer IRT duration, indicating a decrease in motor impulsivity. Modulation of scopolamine-induced impulsivity by olanzapine could be partly due to its antagonistic action at 5-HT2a and 5-HT6 receptors, respectively. Superior effects of olanzapine on impulsivity in schizophrenic patients may be mediated through the antagonism of 5-HT2a and 5-HT6 receptors.

  19. All-trans retinoic acid shifts rosiglitazone-induced adipogenic differentiation to osteogenic differentiation in mouse embryonic fibroblasts.

    PubMed

    Shao, Ying; Chen, Qian-Zhao; Zeng, Yu-Hua; Li, Yang; Ren, Wen-Yan; Zhou, Lin-Yun; Liu, Rong-Xin; Wu, Ke; Yang, Jun-Qing; Deng, Zhong-Liang; Yu, Yu; Sun, Wen-Juan; He, Bai-Cheng

    2016-12-01

    Rosiglitazone (RSG) is a potent drug used in the treatment of insulin resistance; however, it is associated with marked skeletal toxicity. RSG-induced osteoporosis may contribute to the promotion of adipogenic differentiation at the expense of osteogenic differentiation in bone marrow stromal cells. The aim of this study was to investigate whether RSG-induced bone toxicity can be reversed by combined treatment with all-trans retinoic acid (ATRA). We examined different osteogenic markers in mouse embryonic fibroblasts (MEFs) following treatment with RSG, ATRA, or RSG and ATRA in combination. We examined the effects of RSG and/or ATRA on ectopic bone formation, and dissected the possible molecular mechanisms underlying this process. We found that ATRA or RSG both induced alkaline phosphatase (ALP) activity in the MEFs, and that the ATRA-induced ALP activity was enhanced by RSG and vice versa. However, only the combination of RSG and ATRA increased the expression of osteopontin and osteocalcin, promoted matrix mineralization, and induced ectopic ossification in MEFs. Mechanistically, we found that the osteogenic differentiation induced by the combination of RSG and ATRA may be mediated partly by suppressing RSG-induced adipogenic differentiation and activating bone morphogenetic protein (BMP)/Smad signaling. On the whole, our findings demonstrate that RSG in combination with ATRA promotes the commitment of MEFs to the osteoblast lineage. Thus, the combination of these two agents may prove to be a promising and novel therapeutic regimen for insulin resistance without skeletal toxicity. It may also be a better strategy with which to prevent RSG-induced osteoporosis.

  20. All-trans retinoic acid shifts rosiglitazone-induced adipogenic differentiation to osteogenic differentiation in mouse embryonic fibroblasts

    PubMed Central

    Shao, Ying; Chen, Qian-Zhao; Zeng, Yu-Hua; Li, Yang; Ren, Wen-Yan; Zhou, Lin-Yun; Liu, Rong-Xin; Wu, Ke; Yang, Jun-Qing; Deng, Zhong-Liang; Yu, Yu; Sun, Wen-Juan; He, Bai-Cheng

    2016-01-01

    Rosiglitazone (RSG) is a potent drug used in the treatment of insulin resistance; however, it is associated with marked skeletal toxicity. RSG-induced osteoporosis may contribute to the promotion of adipogenic differentiation at the expense of osteogenic differentiation in bone marrow stromal cells. The aim of this study was to investigate whether RSG-induced bone toxicity can be reversed by combined treatment with all-trans retinoic acid (ATRA). We examined different osteogenic markers in mouse embryonic fibroblasts (MEFs) following treatment with RSG, ATRA, or RSG and ATRA in combination. We examined the effects of RSG and/or ATRA on ectopic bone formation, and dissected the possible molecular mechanisms underlying this process. We found that ATRA or RSG both induced alkaline phosphatase (ALP) activity in the MEFs, and that the ATRA-induced ALP activity was enhanced by RSG and vice versa. However, only the combination of RSG and ATRA increased the expression of osteopontin and osteocalcin, promoted matrix mineralization, and induced ectopic ossification in MEFs. Mechanistically, we found that the osteogenic differentiation induced by the combination of RSG and ATRA may be mediated partly by suppressing RSG-induced adipogenic differentiation and activating bone morphogenetic protein (BMP)/Smad signaling. On the whole, our findings demonstrate that RSG in combination with ATRA promotes the commitment of MEFs to the osteoblast lineage. Thus, the combination of these two agents may prove to be a promising and novel therapeutic regimen for insulin resistance without skeletal toxicity. It may also be a better strategy with which to prevent RSG-induced osteoporosis. PMID:27779644

  1. Schwann cells induce neuronal differentiation of bone marrow stromal cells.

    PubMed

    Zurita, Mercedes; Vaquero, Jesús; Oya, Santiago; Miguel, Miriam

    2005-04-04

    Bone marrow stromal cells are multipotent stem cells that have the potential to differentiate into bone, cartilage, fat and muscle. Recently, bone marrow stromal cells have been shown to have the capacity to differentiate into neurons under specific experimental conditions, using chemical factors. We now describe how bone marrow stromal cells can be induced to differentiate into neuron-like cells when they are co-cultured with Schwann cells. When compared with chemical differentiation, expression of neuronal differentiation markers begins later, but one week after beginning co-culture, most bone marrow stromal cells showed a typical neuronal morphology. Our present findings support the transdifferentiation of bone marrow stromal cells, and the potential utility of these cells for the treatment of degenerative and acquired disorders of the nervous system.

  2. Laser-induced differential fluorescence for cancer diagnosis without biopsy

    SciTech Connect

    Vo-Dinh, T.; Panjehpour, M.; Overholt, B.F.; Buckley III, P.

    1997-01-01

    An optical diagnostic procedure based on laser-induced fluorescence was developed for direct {ital in vivo} cancer diagnosis without requiring biopsy. The methodology was applied in a clinical study involving over 100 patients in order to differentiate normal tissue from malignant tumors of the esophagus. Endogenous fluorescence of normal and malignant tissues was measured directly with the use of a fiber-optic probe inserted through an endoscope. The measurements were performed {ital in vivo} during routine endoscopy. Detection of the fluorescence signal from the tissue was performed with the use of laser excitation. This report describes the differential normalized fluorescence (DNF) procedure using the amplified spectral differences between the normalized fluorescence of malignant tissue and normal mucosa. The results of this DNF approach were compared with histopathology results of the biopsy samples and indicated excellent agreement in the classification of normal tissue and malignant tumors for the samples investigated. Data related to various grades of Barrett{close_quote}s esophagus are discussed. The DNF procedure could lead to the development of a rapid and cost-effective technique for cancer diagnosis. {copyright} {ital 1997} {ital Society for Applied Spectroscopy}

  3. Differential Effects of Fatigue on Movement Variability

    PubMed Central

    Cortes, N.; Onate, J.; Morrison, S.

    2014-01-01

    When individuals perform purposeful actions to fatigue, there is typically a general decline in their movement performance. This study was designed to investigate the effects exercise-induced fatigue has on lower limb kinetics and kinematics during a side-step cutting task. In particular, it was of interest to determine what changes could be seen in mean amplitude and all metrics of signal variability with fatigue. The results of the study revealed that post-fatigue there was an overall decrease in absolute force production as reflected by a decline in mean amplitude and variability (SD) of the ground reaction forces (GRFV and GRFML). A decrease in mean and SD of the knee moments were also observed post-exercise. Interestingly, this trend was not mirrored by similar changes in time-dependent properties of these signals. Instead, there was an increase in the SampEn values (reflecting a more variable, irregular signal) for GRF force profiles, knee kinematics and moments following the exercise-induced fatigue. These results illustrate that fatigue can have differential effects on movement variability, resulting in a both an increase and decrease in movement variability, depending on the variable selected. Thus, the impact of fatigue is not simply restricted to a decline in force producing capacity of the system but more importantly it demonstrates that the ability of the person to perform a smooth and controlled action is limited due to fatigue. PMID:24370441

  4. Differential effects of fatigue on movement variability.

    PubMed

    Cortes, N; Onate, J; Morrison, S

    2014-03-01

    When individuals perform purposeful actions to fatigue, there is typically a general decline in their movement performance. This study was designed to investigate the effects exercise-induced fatigue has on lower limb kinetics and kinematics during a side-step cutting task. In particular, it was of interest to determine what changes could be seen in mean amplitude and all metrics of signal variability with fatigue. The results of the study revealed that post-fatigue there was an overall decrease in absolute force production as reflected by a decline in mean amplitude and variability (SD) of the ground reaction forces (GRFV and GRFML). A decrease in mean and SD of the knee moments were also observed post-exercise. Interestingly, this trend was not mirrored by similar changes in time-dependent properties of these signals. Instead, there was an increase in the SampEn values (reflecting a more variable, irregular signal) for GRF force profiles, knee kinematics and moments following the exercise-induced fatigue. These results illustrate that fatigue can have differential effects on movement variability, resulting in a both an increase and decrease in movement variability, depending on the variable selected. Thus, the impact of fatigue is not simply restricted to a decline in force producing capacity of the system but more importantly it demonstrates that the ability of the person to perform a smooth and controlled action is limited due to fatigue.

  5. Differential effect of the inhibition of Grb2-SH3 interactions in platelet activation induced by thrombin and by Fc receptor engagement.

    PubMed Central

    Saci, Abdelhafid; Liu, Wang-Qing; Vidal, Michel; Garbay, Christiane; Rendu, Francine; Bachelot-Loza, Christilla

    2002-01-01

    The adaptor protein Grb2 (growth factor receptor-bound protein 2) is involved in cell proliferation via the Ras signalling pathway. In order to study the role of Grb2 in blood platelet responses, we used a peptide containing two proline-rich sequences derived from Sos (peptidimer), which binds to Grb2-Src homology 3 domain (SH3) with a high affinity, and hence inhibits Grb2-SH3-mediated protein interactions. Platelet aggregation and 5-hydroxytryptamine (serotonin) release measured in the presence of the peptidimer were: (i) significantly decreased when induced by thrombin; and (ii) potentiated when induced by the engagement of the Fc receptor. In thrombin-activated platelets, the Grb2-SH2 domain formed an association with the beta3 subunit of the alphaIIb-beta3 integrin (GPIIb-IIIa), Shc, Syk, Src and SHP1 (SH2-containing phosphotyrosine phosphatase 1), whereas these associations did not occur after the engagement of the receptor for the Fc domain of IgG (FcgammaRIIa) or in resting platelets. Grb2-SH3 domains formed an association with the proline-rich sequences of Sos and Cbl in both resting and activated platelets, since the peptidimer abolished these associations. Inhibition of both fibrinogen binding and platelet aggregation by the peptide RGDS (Arg-Gly-Asp-Ser) had no effect on thrombin-induced Grb2-SH2 domain association with the aforementioned signalling molecules, indicating that these associations occurred during thrombin-induced 'inside-out' signalling. Platelet aggregation induced by direct activation via alphaIIb-beta3 ('outside-in' signalling) was potentiated by the peptidimer. The results show that inhibition of Grb2-SH3 interactions with signal-transduction proteins down-regulates thrombin-induced platelet activation, but also potentiates Fc receptor- and alphaIIb-beta3-mediated platelet activation. PMID:11964172

  6. Differential effects of blockade of dopamine D1-family receptors in nucleus accumbens core or shell on reinstatement of heroin seeking induced by contextual and discrete cues.

    PubMed

    Bossert, Jennifer M; Poles, Gabriela C; Wihbey, Kristina A; Koya, Eisuke; Shaham, Yavin

    2007-11-14

    In humans, exposure to environmental contexts previously associated with heroin intake can provoke drug relapse, but the neuronal mechanisms mediating this relapse are unknown. Using a drug relapse model, we found previously that reexposing rats to heroin-associated contexts, after extinction of drug-reinforced responding in different contexts, reinstates heroin seeking. This effect is attenuated by inhibition of glutamate transmission in the ventral tegmental area and medial accumbens shell, components of the mesolimbic dopamine system. Here, we explored the role of dopamine of the accumbens in context-induced reinstatement by using the D1-family receptor antagonist SCH 23390 [R(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine hydrochloride]. Rats were trained to self-administer heroin for 12 d; drug infusions were paired with a discrete tone-light cue. Subsequently, the heroin-reinforced lever pressing was extinguished in the presence of the discrete cue in a context that differed from the drug self-administration context in terms of visual, auditory, tactile, and circadian cues. When tested in the original drug self-administration context, systemic and medial or lateral accumbens shell SCH 23390 injections attenuated context-induced reinstatement of heroin seeking, whereas accumbens core SCH 23390 injections were ineffective. In contrast, core but not lateral or medial shell SCH 23390 injections attenuated discrete-cue-induced reinstatement in a nondrug context after extinction of lever presses without this cue. Results indicate that activation of medial and lateral accumbens shell D1-family dopamine receptors mediate context-induced reinstatement of heroin seeking and provide the first demonstration for a role of lateral shell dopamine in conditioned drug effects. Results also demonstrate novel dissociable roles of accumbens core and shell in context- versus discrete-cue-induced reinstatement of heroin seeking.

  7. Resveratrol induces human K562 cell apoptosis, erythroid differentiation, and autophagy.

    PubMed

    Yan, Hui-Wen; Hu, Wei-Xin; Zhang, Jie-Ying; Wang, Ye; Xia, Kun; Peng, Min-Yuan; Liu, Jing

    2014-06-01

    Resveratrol (Res) is a naturally occurring phytoalexin with apoptotic and inducing-glob effects in leukemic cells, but the potential induction of erythroid differentiation in cells is not fully understood. Here, we investigated the effects of Res on human erythro-megakaryoblastic leukemia cell line K562. Among the treated cells, proliferation was inhibited and the occurrence of cell apoptosis and cell death were detected. Erythroid differentiation assay was explored, and we found that Res could increase the expression of glycophorin A (GPA), HBA1, HBB, and γ-globin genes and enforced the expression of GPA, CD71, and Band3 proteins. Res also induced K562 cell autophagy when the concentration of Res was increased up to 50 or 100 μM. Our findings suggested that Res possesses the potency not only inducing apoptosis but also inducing erythroid differentiation and autophagy in K562 cells. These results provide that Res may be a therapeutic candidate for chronic myelogenous leukemia treatment.

  8. Identification of differentiation-inducing activity produced by human bone marrow stromal cell line LP101.

    PubMed

    Hiramoto, Masaki; Kawakami, Yutaka; Nabeshima, Ryusuke; Shima, Daisuke; Handa, Hiroshi; Aizawa, Shin

    2004-11-01

    We have previously reported that human promyelocytic leukemia HL-60 cells can be induced to differentiate into mature granulocytes when HL-60 co-cultivated with human bone marrow stromal LP101 cells. In the present study, we investigated which factors produced by LP101 cells induce HL-60 cells to differentiate into mature granulocytes. The expression of the cell surface antigen CD11b on HL-60 cells was increased after a 72-h culture with the conditioned medium (CM) obtained from LP101 cells. LP101 cells were observed to produce various cytokines, including TNF-alpha, GM-CSF and IL-6. The neutralizing antibodies against these cytokines partially suppressed the CM-induced differentiation of HL-60 cells. Recombinant TNF-alpha induced the differentiation of HL-60 cells, and GM-CSF and IL-6 additionally enhanced the effect of TNF-alpha. When the CM was divided into a low molecular weight (LMW) fraction and a high molecular weight (HMW) fraction by ultrafiltration, the LMW fraction synergistically enhanced the differentiation inducible activity of TNF-alpha. These results demonstrate that LP101 cells induce the differentiation of HL-60 cells by producing various cytokines including TNF-alpha, IL-6, and GM-CSF, and that unknown low molecular weight factors also participate.

  9. The "Effectiveness" of Differential Supervision

    ERIC Educational Resources Information Center

    Harris, Patricia M.; Gingerich, Raymond; Whittaker, Tiffany A.

    2004-01-01

    This article presents an evaluation of the Client Management Classification System (CMC), a method for assessment and differential supervision of offenders that embodies the principle of responsivity. As in prior evaluations of the CMC, probationers whose officers were trained in CMC techniques experienced lower rates of revocation compared with…

  10. Differential effects of black raspberry and strawberry extracts on BaPDE-induced activation of transcription factors and their target genes.

    PubMed

    Li, Jingxia; Zhang, Dongyun; Stoner, Gary D; Huang, Chuanshu

    2008-04-01

    The chemopreventive properties of edible berries have been demonstrated both in vitro and in vivo, however, the specific molecular mechanisms underlying their anti-cancer effects are largely unknown. Our previous studies have shown that a methanol extract fraction of freeze-dried black raspberries inhibits benzoapyrene (BaP)-induced transformation of Syrian hamster embryo cells. This fraction also blocks activation of activator protein-1 (AP-1) and nuclear factor kappaB (NF-kappaB) induced by benzoapyrene diol-epoxide (BaPDE) in mouse epidermal JB6 Cl 41 cells. To determine if different berry types exhibit specific mechanisms for their anti-cancer effects, we compared the effects of extract fractions from both black raspberries and strawberries on BaPDE-induced activation of various signaling pathways in Cl 41 cells. Black raspberry fractions inhibited the activation of AP-1, NF-kappaB, and nuclear factor of activated T cells (NFAT) by BaPDE as well as their upstream PI-3K/Akt-p70(S6K) and mitogen-activated protein kinase pathways. In contrast, strawberry fractions inhibited NFAT activation, but did not inhibit the activation of AP-1, NF-kappaB or the PI-3K/Akt-p70(S6K) and mitogen-activated protein kinase pathways. Consistent with the effects on NFAT activation, tumor necrosis factor-alpha (TNF-alpha) induction by BaPDE was blocked by extract fractions of both black raspberries and strawberries, whereas vascular endothelial growth factor (VEGF) expression, which depends on AP-1 activation, was suppressed by black raspberry fractions but not strawberry fractions. These results suggest that black raspberry and strawberry components may target different signaling pathways in exerting their anti-carcinogenic effects.

  11. Resistance of glia-like central and peripheral neural stem cells to genetically induced mitochondrial dysfunction--differential effects on neurogenesis.

    PubMed

    Díaz-Castro, Blanca; Pardal, Ricardo; García-Flores, Paula; Sobrino, Verónica; Durán, Rocío; Piruat, José I; López-Barneo, José

    2015-11-01

    Mitochondria play a central role in stem cell homeostasis. Reversible switching between aerobic and anaerobic metabolism is critical for stem cell quiescence, multipotency, and differentiation, as well as for cell reprogramming. However, the effect of mitochondrial dysfunction on neural stem cell (NSC) function is unstudied. We have generated an animal model with homozygous deletion of the succinate dehydrogenase subunit D gene restricted to cells of glial fibrillary acidic protein lineage (hGFAP-SDHD mouse). Genetic mitochondrial damage did not alter the generation, maintenance, or multipotency of glia-like central NSCs. However, differentiation to neurons and oligodendrocytes (but not to astrocytes) was impaired and, hence, hGFAP-SDHD mice showed extensive brain atrophy. Peripheral neuronal populations were normal in hGFAP-SDHD mice, thus highlighting their non-glial (non hGFAP(+)) lineage. An exception to this was the carotid body, an arterial chemoreceptor organ atrophied in hGFAP-SDHD mice. The carotid body contains glia-like adult stem cells, which, as for brain NSCs, are resistant to genetic mitochondrial damage.

  12. Resistance of glia-like central and peripheral neural stem cells to genetically induced mitochondrial dysfunction—differential effects on neurogenesis

    PubMed Central

    Díaz-Castro, Blanca; Pardal, Ricardo; García-Flores, Paula; Sobrino, Verónica; Durán, Rocío; Piruat, José I; López-Barneo, José

    2015-01-01

    Mitochondria play a central role in stem cell homeostasis. Reversible switching between aerobic and anaerobic metabolism is critical for stem cell quiescence, multipotency, and differentiation, as well as for cell reprogramming. However, the effect of mitochondrial dysfunction on neural stem cell (NSC) function is unstudied. We have generated an animal model with homozygous deletion of the succinate dehydrogenase subunit D gene restricted to cells of glial fibrillary acidic protein lineage (hGFAP-SDHD mouse). Genetic mitochondrial damage did not alter the generation, maintenance, or multipotency of glia-like central NSCs. However, differentiation to neurons and oligodendrocytes (but not to astrocytes) was impaired and, hence, hGFAP-SDHD mice showed extensive brain atrophy. Peripheral neuronal populations were normal in hGFAP-SDHD mice, thus highlighting their non-glial (non hGFAP+) lineage. An exception to this was the carotid body, an arterial chemoreceptor organ atrophied in hGFAP-SDHD mice. The carotid body contains glia-like adult stem cells, which, as for brain NSCs, are resistant to genetic mitochondrial damage. PMID:26392570

  13. Differential effect of pH upon cyclic-ADP-ribose and nicotinate-adenine dinucleotide phosphate-induced Ca2+ release systems.

    PubMed Central

    Chini, E N; Liang, M; Dousa, T P

    1998-01-01

    We investigated the pH dependence and the effects of thimerosal and dithiothreitol (DTT) upon the Ca2+ release induced by cADP-ribose (cADPR) and nicotinate-adenine dinucleotide phosphate (NAADP) in sea urchin egg homogenates. Both Ca2+ release triggered by cADPR and the binding of [3H]cADPR to sea urchin egg homogenates were decreased by alkalization of the assay media from pH 7.2 to 8.9. In contrast, NAADP-triggered Ca2+ release was not influenced by changes in pH. The Ca2+ release induced by cADPR was potentiated by thimerosal and inhibited by DTT, but neither thimerosal nor DTT had any effect upon the Ca2+ release induced by NAADP. We conclude that cADPR-sensitive Ca2+-release mechanisms are dependent on pH of the assay media and are sensitive to thiol group modification. On the other hand, these functional properties are not shared by NAADP-regulated Ca2+ channels. PMID:9794787

  14. Chemical inducers of differentiation in a long-term renal cell line.

    PubMed Central

    Lever, J E

    1989-01-01

    The long-term renal epithelial cell line LLC-PK1 expresses at confluence several differentiated characteristics of renal proximal tubule including Na/glucose cotransport and several brush border membrane hydrolases. The differentiation-inducing chemical hexamethylene bisacetamide (HMBA) triggers a dramatic induction of Na+/glucose symport, trehalase and maltase, expressed as an increase in the number of cells in the culture that express the differentiated phenotype. Characteristics of the induction response are reviewed in terms of proposed mechanisms of inducer action. New evidence suggests that in addition to elevation of intracellular Na levels mediated by partial inhibition of the sodium pump, HMBA treatment also alters polyamine levels via effects on ornithine decarboxylase. These responses may be mediated by HMBA effects on protein kinase C activity. The possible role of polyamine fluctuations and DNA demethylation in mediating HMBA effects on differentiated gene expression is currently being investigated. Images FIGURE 2. FIGURE 3. PMID:2647478

  15. Behavioral modulation of neuronal calcium/calmodulin-dependent protein kinase II activity: differential effects on nicotine-induced spinal and supraspinal antinociception in mice.

    PubMed

    Damaj, M Imad

    2007-10-15

    Recent studies have implicated the involvement of Ca(2+)-dependent mechanisms, in particular calcium/calmodulin-dependent protein kinase II (CaM kinase II) in nicotine-induced antinociception using the tail-flick test. The spinal cord was suggested as a possible site of this involvement. The present study was undertaken to investigate the hypothesis that similar mechanisms exist for nicotine-induced antinociception in the hot-plate test, a response thought to be centrally mediated. In order to assess these mechanisms, i.c.v. administered CaM kinase II inhibitors were evaluated for their effects on antinociception produced by either i.c.v. or s.c. administration of nicotine in both tests. In addition, nicotine's analgesic effects were tested in mice lacking half of their CaM kinase II (CaM kinase II heterozygous) and compare it to their wild-type counterparts. Our results showed that although structurally unrelated CaM kinase II inhibitors blocked nicotine's effects in the tail-flick test in a dose-related manner, they failed to block the hot-plate responses. In addition, the antinociceptive effects of systemic nicotine in the tail-flick but not the hot-plate test were significantly reduced in CaM kinase II heterozygous mice. These observations indicate that in contrast to the tail-flick response, the mechanism of nicotine-induced antinociception in the hot-plate test is not mediated primarily via CaM kinase II-dependent mechanisms at the supraspinal level.

  16. Wnt signaling pathway participates in valproic acid-induced neuronal differentiation of neural stem cells.

    PubMed

    Wang, Li; Liu, Yuan; Li, Sen; Long, Zai-Yun; Wu, Ya-Min

    2015-01-01

    Neural stem cells (NSCs) are multipotent cells that have the capacity for differentiation into the major cell types of the nervous system, i.e. neurons, astrocytes and oligodendrocytes. Valproic acid (VPA) is a widely prescribed drug for seizures and bipolar disorder in clinic. Previously, a number of researches have been shown that VPA has differential effects on growth, proliferation and differentiation in many types of cells. However, whether VPA can induce NSCs from embryonic cerebral cortex differentiate into neurons and its possible molecular mechanism is also not clear. Wnt signaling is implicated in the control of cell growth and differentiation during CNS development in animal model, but its action at the cellular level has been poorly understood. In this experiment, we examined neuronal differentiation of NSCs induced by VPA culture media using vitro immunochemistry assay. The neuronal differentiation of NSCs was examined after treated with 0.75 mM VPA for three, seven and ten days. RT-PCR assay was employed to examine the level of Wnt-3α and β-catenin. The results indicated that there were more β-tublin III positive cells in NSCs treated with VPA medium compared to the control group. The expression of Wnt-3α and β-catenin in NSCs treated with VPA medium was significantly greater compared to that of control media. In conclusion, these findings indicated that VPA could induce neuronal differentiation of NSCs by activating Wnt signal pathway.

  17. CADASIL-associated Notch3 mutations have differential effects both on ligand binding and ligand-induced Notch3 receptor signaling through RBP-Jk.

    PubMed

    Peters, Nils; Opherk, Christian; Zacherle, Simone; Capell, Anja; Gempel, Petra; Dichgans, Martin

    2004-10-01

    Mutations in the NOTCH3 gene are the cause of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), a hereditary angiopathy leading to strokes and dementia. Pathogenic mutations remove or insert cysteine residues within epidermal growth factor (EGF) repeats in the extracellular domain of the Notch3 receptor (N3ECD). Vascular smooth muscle cells (VSMC) are the predominant site of Notch3 expression in adults. In CADASIL patients, VSMC degenerate and N3ECD is deposited within the vasculature. However, the mechanisms underlying VSMC degeneration and N3ECD accumulation are still unknown. In this study, we investigated the consequences of three pathogenic Notch3 mutations on the biological activity of the receptor by analyzing ligand (Delta-/Jagged-)-induced signaling via RBP-Jk. Two mutations (R133C and C183R) that are located outside the putative ligand binding domain (LBD) of the receptor were found to result in normal Jagged1-induced signaling in A7r5 VSMC, whereas the third mutation (C455R located within the putative LBD) showed strongly reduced signaling activity. Ligand binding assays with soluble Delta1 and Jagged1 revealed that C455R interferes with ligand binding through disruption of the LBD which, as we show here, is located in EGF repeats 10/11 of Notch3. All mutant receptors including Notch3C455R were targeted to the cell surface but showed an elevated ratio between the unprocessed full-length 280-kDa receptor and S1-cleaved receptor fragments. Taken together, these data indicate that CADASIL-associated Notch3 mutations differ with respect to their consequences both on ligand binding and ligand-induced signaling through RBP-Jk, whereas they have similar effects on receptor maturation. Moreover, the data suggest that ligand-induced receptor shedding may not be required for N3ECD deposition in CADASIL.

  18. Interleukin-34 induces monocytic-like differentiation in leukemia cell lines.

    PubMed

    Booker, Burthia E; Clark, Ryan S; Pellom, Samuel T; Adunyah, Samuel E

    2015-01-01

    Interleukin-34 (IL-34) is a cytokine consisting of a 39kD homodimer, shown to be a ligand for both the Macrophage Colony Stimulating Factor (M-CSF/CSF-1) receptor and the Receptor-like protein tyrosine phosphatase-zeta (RPTP-ƺ). IL-34 has been shown to promote monocyte viability and proliferation as well as the differentiation of bone marrow cells into macrophage progenitors. Published work on IL-34 involves its effects on normal hematopoietic and osteoclast progenitors. However, it is not known whether IL-34 has biologic effects in cancer, including leukemia. Here we report that the biological effects of IL-34 include induction of differential expression of Interleukins-1α and -1β as well as induction of differentiation of U937, HL-60 and THP-1 leukemia cell lines demonstrating monocyte-like characteristics. The ability of IL-34 to induce monocytic-like differentiation is supported by strong morphological and functional evidence. Cell surface markers of myeloid lineage, CD64 and CD86, remain constant while the levels of CD11b and CD71 decline with IL-34 treatment. IL-34 also induced increases in CD14 and CD68 expression, further supporting maturation toward monocytic character. IL-34-induced differentiated U937 and THP-1 cell lines exhibited biological functions such as endocytosis and respiratory burst activities. Collectively, we conclude that while IL-34 does not induce cell growth or proliferation, it is able to induce differentiation of leukemia cell lines from monoblastic precursor cells towards monocyte- and macrophage-like cells, mediated through the JAK/STAT and PI3K/Akt pathways. To our knowledge, this is the first report that IL-34 induces differentiation in human leukemic cells, let alone any cancer model.

  19. Valproic acid induces apoptosis and cell cycle arrest in poorly differentiated thyroid cancer cells.

    PubMed

    Catalano, Maria G; Fortunati, Nicoletta; Pugliese, Mariateresa; Costantino, Lucia; Poli, Roberta; Bosco, Ornella; Boccuzzi, Giuseppe

    2005-03-01

    Poorly differentiated thyroid carcinoma is an aggressive human cancer that is resistant to conventional therapy. Histone deacetylase inhibitors are a promising class of drugs, acting as antiproliferative agents by promoting differentiation, as well as inducing apoptosis and cell cycle arrest. Valproic acid (VPA), a class I selective histone deacetylase inhibitor widely used as an anticonvulsant, promotes differentiation in poorly differentiated thyroid cancer cells by inducing Na(+)/I(-) symporter and increasing iodine uptake. Here, we show that it is also highly effective at suppressing growth in poorly differentiated thyroid cancer cell lines (N-PA and BHT-101). Apoptosis induction and cell cycle arrest are the underlying mechanisms of VPA's effect on cell growth. It induces apoptosis by activating the intrinsic pathway; caspases 3 and 9 are activated but not caspase 8. Cell cycle is selectively arrested in G(1) and is associated with the increased expression of p21 and the reduced expression of cyclin A. Both apoptosis and cell cycle arrest are induced by treatment with 1 mm VPA, a dose that promotes cell redifferentiation and that is slightly above the serum concentration reached in patients treated for epilepsy. These multifaceted properties make VPA of clinical interest as a new approach to treating poorly differentiated thyroid cancer.

  20. Tart cherry juice induces differential dose-dependent effects on apoptosis, but not cellular proliferation, in MCF-7 human breast cancer cells.

    PubMed

    Martin, Keith R; Wooden, Alissa

    2012-11-01

    Consumption of polyphenol-rich fruits, for example, tart cherries, is associated with a lower risk of cardiovascular disease and cancer. This is due, in large part, to the diverse myriad bioactive agents, that is, polyphenol anthocyanins, present in fruits. Anthocyanin-rich tart cherries purportedly modulate numerous cellular processes associated with oncogenesis such as apoptosis, cellular proliferation (CP), and cell cycle progression, although the effective concentrations eliciting these effects are unclear. We hypothesized that several dose-dependent effects over a large concentration range of 100% tart cherry juice (TCJ) would exist and affect these processes differentially with the potential for cellular protection and cellular death either by apoptosis or by necrosis. In this in vitro study, we tested the dose response of TCJ on CP and cell death in MCF-7 human breast cancer cells. TCJ was added at 0.03-30% (v/v) to cells and incubated overnight with the medium alone or with increasing TCJ. Bromodeoxyuridine incorporation was significantly reduced by 20% at ≥10% (v/v) TCJ and associated with necrosis, but was not different between the control and treatment groups at <10% TCJ. MTT reduction was also significantly reduced by 27% and 80% at 10% and 30% TCJ, respectively, and associated with necrosis. Apoptosis, but not necrosis, was increased ∼63% at 3% TCJ (∼307 nM monomeric anthocyanins), yet significantly decreased (P<.05) by 20% at 1% TCJ (920 nM) both of which were physiologically relevant concentrations of anthocyanins. The data support a biphasic effect on apoptosis and no effect on proliferation.

  1. Differential effect of dark rearing on long-term potentiation induced by layer IV and white matter stimulation in rat visual cortex.

    PubMed

    Salami, M; Fathollahi, Y; Semnanian, S; Atapour, N

    2000-12-01

    In the earlier work, we showed that primed-burst stimulation (PBs) is an effective protocol to induce long-term potentiation (LTP) in layer II/III of adult rat visual cortex in vitro. In the present study, we investigated effects of dark rearing on potentiation of layer II/III responses to stimulation of layer IV or the underlying white matter in the visual cortex in vitro. Long-term potentiation was induced by PBs applied to white matter or layer IV of the cortex in light and dark reared rats. Regardless of the stimulation site, layer II/III field potentials consisted of two components. In general, the latency of responses in dark reared rats was shorter than that in light reared ones. Whereas PBs of layer IV produced LTP of two components in both the groups, that of white matter induced an appreciable potentiation of the second component in both groups and the first component only in dark reared rats. These results indicate that PBs of either white matter or layer IV can gain access to the modifiable synapses that are related to the second component of layer II/III responses in light and dark reared visual cortex, but accessibility of the modifiable synapses that are related to first component depends on the tetanization site. The dark rearing enhances accessibility of the modifiable synapses that are related to the first component following PBs of the white matter. It is suggested that the immaturity of inhibitory circuits and/or better function of excitatory ones in the visual cortex of dark reared rats may contribute to the enhanced accessibility of the first component.

  2. Differential effects of Bcl-2 and caspases on mitochondrial permeabilization during endogenous or exogenous reactive oxygen species-induced cell death: a comparative study of H₂O₂, paraquat, t-BHP, etoposide and TNF-α-induced cell death.

    PubMed

    Rincheval, Vincent; Bergeaud, Marie; Mathieu, Lise; Leroy, Jacqueline; Guillaume, Arnaud; Mignotte, Bernard; Le Floch, Nathalie; Vayssière, Jean-Luc

    2012-08-01

    In this study, we have compared several features of cell death triggered by classical inducers of apoptotic pathways (etoposide and tumour necrosis factor (TNF)-α) versus exogenous reactive oxygen species (ROS; hydrogen peroxide (H₂O₂), tert-butyl hydroperoxide (t-BHP)) or a ROS generator (paraquat). Our aim was to characterize relationships that exist between ROS, mitochondrial perturbations, Bcl-2 and caspases, depending on source and identity of ROS. First, we have found that these five inducers trigger oxidative stress, mitochondrial membrane permeabilization (MMP), cytochrome c (cyt c) release from mitochondria and cell death. In each case, cell death could be inhibited by several antioxidants, showing that it is primarily ROS dependent. Second, we have highlighted that during etoposide or TNF-α treatments, intracellular ROS level, MMP and cell death are all regulated by caspases and Bcl-2, with caspases acting early in the process. Third, we have demonstrated that H₂O₂-induced cell death shares many of these characteristics with etoposide and TNF-α, whereas t-BHP induces both caspase-dependent and caspase-independent cell death. Surprisingly, paraquat-induced cell death, which harbours some characteristics of apoptosis such as cyt c release and caspase-3 activation, is not modulated by Bcl-2 and caspase inhibitors, suggesting that paraquat also triggers non-apoptotic cell death signals. On the one hand, these results show that endogenous or exogenous ROS can trigger multiple cell death pathways with Bcl-2 and caspases acting differentially. On the other hand, they suggest that H₂O₂ could be an important mediator of etoposide and TNF-α-dependent cell death since these inducers trigger similar phenotypes.

  3. Differential effects of endothelins on histological and ultrastructural changes and trypsinogen activation in the secretagogue-induced acute pancreatitis in rats.

    PubMed

    Andrzejewska, Anna; Dlugosz, Jan W

    2011-05-01

    The role of endothelins in acute pancreatitis remains obscure. To assess the effects of endothelins (ETs) in early (4 h) caerulein-induced acute pancreatitis (AP) in rats, ET-1, ET-2 and ET-3 (0.5 or 1.0 nmol/kg) were applied twice with i.p. caerulein (2×40 μg/kg) at 1h interval. Histological and ultrastructural examinations of pancreases and the assay of trypsinogen activation in whole homogenate were performed. All ETs, especially ET-1 at the higher dose, decreased inflammatory cell infiltration despite an increase in the edema score. The vacuolization and necrosis of acinar cells were slightly increased after the lower dose of ET-1 and ET-2. Ultrastructural changes were generally improved after the higher dose of ETs. Trypsinogen activation increased from 4.8±1.3% in control to 18.4±3.8% in AP (p<0.01). It was attenuated to 6.4±1.3% (p<0.01) by the higher dose of ET-1 and to 8.8±1.5% (p<0.05) by the lower dose of ET-3. In summary, ETs, especially ET-1 at the higher dose, were found to have some beneficial effects on morphological changes and trypsinogen activation in the pancreas in early caerulein-induced AP.

  4. Differential responses to blood pressure and oxidative stress in streptozotocin-induced diabetic Wistar-Kyoto rats and spontaneously hypertensive rats: effects of antioxidant (honey) treatment.

    PubMed

    Erejuwa, Omotayo O; Sulaiman, Siti A; Wahab, Mohd Suhaimi Ab; Sirajudeen, Kuttulebbai N S; Salleh, Md Salzihan Md; Gurtu, Sunil

    2011-01-01

    Oxidative stress is implicated in the pathogenesis and/or complications of hypertension and/or diabetes mellitus. A combination of these disorders increases the risk of developing cardiovascular events. This study investigated the effects of streptozotocin (60 mg/kg; ip)-induced diabetes on blood pressure, oxidative stress and effects of honey on these parameters in the kidneys of streptozotocin-induced diabetic Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). Diabetic WKY and SHR were randomized into four groups and received distilled water (0.5 mL) and honey (1.0 g/kg) orally once daily for three weeks. Control SHR had reduced malondialdehyde (MDA) and increased systolic blood pressure (SBP), catalase (CAT) activity, and total antioxidant status (TAS). SBP, activities of glutathione peroxidase (GPx) and glutathione reductase (GR) were elevated while TAS was reduced in diabetic WKY. In contrast, SBP, TAS, activities of GPx and GR were reduced in diabetic SHR. Antioxidant (honey) treatment further reduced SBP in diabetic SHR but not in diabetic WKY. It also increased TAS, GSH, reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio, activities of GPx and GR in diabetic SHR. These data suggest that differences in types, severity, and complications of diseases as well as strains may influence responses to blood pressure and oxidative stress.

  5. Silver nanoparticles impede phorbol myristate acetate-induced monocyte-macrophage differentiation and autophagy

    NASA Astrophysics Data System (ADS)

    Xu, Yingying; Wang, Liming; Bai, Ru; Zhang, Tianlu; Chen, Chunying

    2015-09-01

    Monocytes/macrophages are important constituents of the innate immune system. Monocyte-macrophage differentiation is not only crucial for innate immune responses, but is also related to some cardiovascular diseases. Silver nanoparticles (AgNPs) are one of the most widely used nanomaterials because of their broad-spectrum antimicrobial properties. However, the effect of AgNPs on the functions of blood monocytes is scarcely reported. Here, we report the impedance effect of AgNPs on THP-1 monocyte differentiation, and that this effect was mediated by autophagy blockade and lysosomal impairment. Firstly, AgNPs inhibit phorbol 12-myristate 13-acetate (PMA)-induced monocyte differentiation by down-regulating both expression of surface marker CD11b and response to lipopolysaccharide (LPS) stimulation. Secondly, autophagy is activated during PMA-induced THP-1 monocyte differentiation, and the autophagy inhibitor chloroquine (CQ) can inhibit this process. Thirdly, AgNPs block the degradation of the autophagy substrate p62 and induce autophagosome accumulation, which demonstrates the blockade of autophagic flux. Fourthly, lysosomal impairments including alkalization and decrease of lysosomal membrane stability were observed in AgNP-treated THP-1 cells. In conclusion, we demonstrate that the impedance of monocyte-macrophage differentiation by AgNPs is mediated by autophagy blockade and lysosomal dysfunction. Our results suggest that crosstalk exists in different biological effects induced by AgNPs.

  6. Pyranocoumarins isolated from Peucedanum praeruptorum as differentiation inducers in human leukemic HL-60 cells.

    PubMed

    Zhang, Jin-Xia; Fong, Wang-Fun; Wu, Jimmy Yiu-Cheong; Yang, Mengsu; Cheung, Hon-Yeung

    2003-03-01

    Differentiation therapy for myeloid leukemia offers great potential as a supplement to the current treatment modalities. In the present report, we investigated if the pyranocoumarins, (+/-)-4'- O-acetyl-3'- O-angeloyl- cis-khellactone (or angular pyranocoumarin, APC) isolated from the medicinal plant Peucedanum praeruptorum Dunn, could induce human acute myeloid leukemic HL-60 cells to differentiate and elucidated the molecular mechanism(s) involved. The ability of HL-60 cells to reduce nitroblue tetrazolium (NBT) was significantly increased after APC treatment for 72 h. In these differentiating HL-60 cells, cell surface differentiation markers CD11b (for myeloid cells) and CD14 (for monocytic cells) were detected in 90.3 % and 70.1 % of the cells, respectively. The differentiation inducing effect of APC was time- and dose-dependent. Treatment with 20 microg/mL APC for 72 h inhibited cell growth by 90 % and cell cycle analysis revealed an increase in the proportion of G1 phase cells. In these growth-inhibited cells the expression of the cyclin-dependent kinase inhibitor p27 kip1, but not p21 WAF1, was up-regulated as shown by Western blotting. Differentiation inducing signal pathways were investigated and it was shown that phospho-MEK and phospho-ERK were elevated shortly after the addition of APC. Pre-incubation of the cells with MEK1 inhibitor PD98059 blocked this APC-induced differentiation. Our results suggest that APC are potent inducers of HL-60 cell differentiation along both the myelocytic and monocytic lineages and are potential agents for differentiation-treatment of leukemia.

  7. Differential effects of isoflurane and CO2 inhalation on plasma levels of inflammatory markers associated with collagen-induced arthritis in DBA mice.

    PubMed

    Lawrance, Christopher C; Lucas, Edralin A; Clarke, Stephen L; Smith, Brenda J; Kuvibidila, Solo

    2009-07-01

    Inhalation of CO2 or isoflurane is a commonly used method of euthanasia with mice, but information related to their effects on serum inflammatory markers in chronic models of inflammation is limited. In the current study, nineteen-week old DBA female mice with (n = 53) or without (n = 51) collagen-induced arthritis were randomly assigned to euthanization with CO2 (n = 55) or isoflurane (n = 49. Plasma was collected for the measurement of soluble intercellular adhesion molecule-1 (sICAM-1), tumor necrosis factor alpha (TNF-alpha), and interleukin-6 (IL-6) by ELISA. When mice without and with collagen-induced arthritis were pooled, compared to CO2, administration of isoflurane was associated with lower production of the pro-inflammatory cytokines TNF-alpha (pg/ml, mean +/- SEM) (26.1 +/- 2.82 versus 48.1 +/- 7.99) and IL-6 (25.18 +/- 2.73 versus 48.1 +/- 6.82) (ANOVA, p < 0.05). In contrast to TNF-alpha and IL-6, administration of CO2 decreased the plasma sICAM-1 level (1170+/- 50 versus 758 +/- 24 for CO2) (p < 0.00001). When data were analyzed as a function of collagen-induced arthritis, the differences between CO2 and isoflurane persisted. Low plasma sICAM-1 levels found in CO2 euthanasia group may be due to degradation. Since mice are the most common animal model for studying inflammation, researchers should be aware of these iatrogenic experimental variables before interpreting their data.

  8. Differential effect of manool--a diterpene from Salvia officinalis, on genotoxicity induced by methyl methanesulfonate in V79 and HepG2 cells.

    PubMed

    Nicolella, Heloiza Diniz; de Oliveira, Pollyanna Francielli; Munari, Carla Carolina; Costa, Gizela Faleiros Dias; Moreira, Monique Rodrigues; Veneziani, Rodrigo Cassio Sola; Tavares, Denise Crispim

    2014-10-01

    Salvia officinalis (sage) is a perennial woody subshrub native to the Mediterranean region that is commonly used as a condiment and as an anti-inflammatory, antioxidant and antimicrobial agent due to its biological activities. Manool is the most abundant micro-metabolite found in Salvia officinalis essential oils and extracts. We therefore decided to evaluate the cytotoxic, genotoxic and antigenotoxic potential of manool in Chinese hamster lung fibroblasts (V79) and human hepatoma cells (HepG2). Cytotoxicity was assessed by the colony-forming assay in V79 cells and toxic effects were observed at concentrations of up to 8.0 μg/mL. The micronucleus test was used to evaluate the genotoxicity and antigenotoxicity of manool in V79 and HepG2 cells at concentrations of 0.5-6.0 μg/mL and 0.5-8.0 μg/mL, respectively. For evaluation of antigenotoxicity, the concentrations of manool were combined with methyl methanesulfonate (MMS, 44 μg/mL). The results showed a significant increase in the frequency of micronuclei in cultures of both cell lines treated with the highest concentration tested, demonstrating a genotoxic effect. On the other hand, manool exhibited a protective effect against chromosome damage induced by MMS in HepG2 cells, but not in V79 cells. These data suggest that some manool metabolite may be responsible for the antigenotoxic effect observed in HepG2 cells.

  9. Did 26Al and impact-induced heating differentiate Mercury?

    NASA Astrophysics Data System (ADS)

    Bhatia, G. K.; Sahijpal, S.

    2017-02-01

    Numerical models dealing with the planetary scale differentiation of Mercury are presented with the short-lived nuclide, 26Al, as the major heat source along with the impact-induced heating during the accretion of planets. These two heat sources are considered to have caused differentiation of Mars, a planet with size comparable to Mercury. The chronological records and the thermal modeling of Mars indicate an early differentiation during the initial 1 million years (Ma) of the formation of the solar system. We theorize that in case Mercury also accreted over an identical time scale, the two heat sources could have differentiated the planets. Although unlike Mars there is no chronological record of Mercury's differentiation, the proposed mechanism is worth investigation. We demonstrate distinct viable scenarios for a wide range of planetary compositions that could have produced the internal structure of Mercury as deduced by the MESSENGER mission, with a metallic iron (Fe-Ni-FeS) core of radius 2000 km and a silicate mantle thickness of 400 km. The initial compositions were derived from the enstatite and CB (Bencubbin) chondrites that were formed in the reducing environments of the early solar system. We have also considered distinct planetary accretion scenarios to understand their influence on thermal processing. The majority of our models would require impact-induced mantle stripping of Mercury by hit and run mechanism with a protoplanet subsequent to its differentiation in order to produce the right size of mantle. However, this can be avoided if we increase the Fe-Ni-FeS contents to 71% by weight. Finally, the models presented here can be used to understand the differentiation of Mercury-like exoplanets and the planetary embryos of Venus and Earth.

  10. Airway arginase expression and Nω-hydroxy-nor-arginine effect on methacholine-induced bronchoconstriction differentiate Lewis and Fischer rat strains.

    PubMed

    Risse, Paul-André; Lavoie-Lamoureux, Anouk; Jo, Taisuke; Tsuchiya, Kimitake; Siddiqui, Sana; Martin, James G

    2014-03-15

    Innate airway hyperresponsiveness (AHR) is well modeled by two strains of rat, the hyperresponsive Fischer 344 rat and the normoresponsive Lewis rat. Arginase has been implicated in AHR associated with allergic asthma models. We addressed the role of arginase in innate AHR using the Fischer-Lewis model. In vivo arginase inhibition with N(ω)-hydroxy-nor-arginine (nor-NOHA) was evaluated on methacholine-induced bronchoconstriction in the Fischer and the Lewis rats. Arginase activity and mRNA expression were quantified in structural and resident cells of the proximal airway tree. The effect of nor-NOHA was evaluated on cultured tracheal smooth muscle proliferation. Fischer rats exhibited significantly greater changes in respiratory resistance and elastance in response to methacholine compared with Lewis rats. nor-NOHA reduced the methacholine-induced bronchoconstriction in the central airways of Lewis rats, while it did not change the innate AHR of Fischer rats. Lewis rats exhibited greater arginase activity in tracheal smooth muscle but a lower proliferation rate compared with Fischer rats. Smooth muscle proliferation was not affected by nor-NOHA in either strain of rats. The strain-specific arginase expression in the smooth muscle may contribute to the differences in sensitivity of the methacholine challenged airways of Lewis and Fischer rats to inhibition of arginase.

  11. Metformin induces differentiation in acute promyelocytic leukemia by activating the MEK/ERK signaling pathway

    SciTech Connect

    Huai, Lei; Wang, Cuicui; Zhang, Cuiping; Li, Qihui; Chen, Yirui; Jia, Yujiao; Li, Yan; Xing, Haiyan; Tian, Zheng; Rao, Qing; Wang, Min; Wang, Jianxiang

    2012-06-08

    Highlights: Black-Right-Pointing-Pointer Metformin induces differentiation in NB4 and primary APL cells. Black-Right-Pointing-Pointer Metformin induces activation of the MEK/ERK signaling pathway in APL cells. Black-Right-Pointing-Pointer Metformin synergizes with ATRA to trigger maturation of NB4 and primary APL cells. Black-Right-Pointing-Pointer Metformin induces the relocalization and degradation of the PML-RAR{alpha} fusion protein. Black-Right-Pointing-Pointer The study may be applicable for new differentiation therapy in cancer treatment. -- Abstract: Recent studies have shown that metformin, a widely used antidiabetic agent, may reduce the risk of cancer development. In this study, we investigated the antitumoral effect of metformin on both acute myeloid leukemia (AML) and acute promyelocytic leukemia (APL) cells. Metformin induced apoptosis with partial differentiation in an APL cell line, NB4, but only displayed a proapoptotic effect on several non-M3 AML cell lines. Further analysis revealed that a strong synergistic effect existed between metformin and all-trans retinoic acid (ATRA) during APL cell maturation and that metformin induced the hyperphosphorylation of extracellular signal-regulated kinase (ERK) in APL cells. U0126, a specific MEK/ERK activation inhibitor, abrogated metformin-induced differentiation. Finally, we found that metformin induced the degradation of the oncoproteins PML-RAR{alpha} and c-Myc and activated caspase-3. In conclusion, these results suggest that metformin treatment may contribute to the enhancement of ATRA-induced differentiation in APL, which may deepen the understanding of APL maturation and thus provide insight for new therapy strategies.

  12. Effect of nanogroove geometry on adipogenic differentiation

    NASA Astrophysics Data System (ADS)

    Kim, M. S.; Kim, A. Y.; Jang, K. J.; Kim, J. H.; Kim, J. B.; Suh, K. Y.

    2011-12-01

    We present the effect of nanotopographically defined surfaces on adipocyte differentiation using various nanogroove patterns. Parallel nanogroove arrays with equal inter-groove distance (400, 550, 800 nm width) and varying distances (550 nm width with three different spacings of 550, 1100, and 2750 nm) were fabricated by UV-assisted capillary force lithography (CFL) on 18 mm diameter glass coverslips using biocompatible polyurethane (PU)-based material. After coating with fibronectin and subsequent culture of 3T3-L1 preadipocytes, the degree of adipocyte differentiation was determined by Oil Red O staining and adipogenic gene expression. We observed that adipocyte differentiation was slightly but substantially affected by culture on various nanogrooved surfaces. In particular, the cell crawling into nanogrooves contributed substantially to an enhanced level of differentiation with higher contact guidance, suggesting that cell-to-surface interactions would play a role for the adipocyte differentiation.

  13. Involvement of PIKE in icariin induced cardiomyocyte differentiation from murine embryonic stem cells.

    PubMed

    Zhou, Limin; Zheng, Bei; Tang, Leilei; Huang, Yujie; Zhu, Danyan

    2014-03-01

    Icariin (ICA) has demonstrated to induce cardiomyocyte differentiation from murine embryonic stem (ES) cells in vitro, however, the mechanisms have not been fully elucidated. In the present study, we investigated whether phosphatidylinositol 3-kinase enhancer (PIKE) was involved in ICA induced cardiomyocyte differentiation of ES cells. Small interfering RNA (siRNA) of PIKE was applied to investigate the role of PIKE in ICA induced cardiomyocyte differentiation. The cardiomyocytes derived from ES cells were verified using immunofluorescence. The expressions of Troponin T, PIKE, phosphatidylinositol 3-kinase (PI3K), and nuclear factor-kappaB (NF-kappaB) were detected by western blot. The change of reactive oxygen species (ROS) generation was estimated using the fluorescent dye 2', 7' - dichlorodihydrofluorescein diacetate. The results showed that PIKE expression increased during cardiomyocyte differentiation. ICA markedly enhanced PIKE and PI3K expression in a time-dependent manner. Knockdown of PIKE by siRNAs blocked the differentiation of ES cells into cardiomyocytes expressing alpha-actinin for cardiac sarcomeric structures. Moreover, reduced ROS generation and NF-kappaB nuclear translocation were responsible for the inhibitory effect of si-PIKE. In conclusion, PIKE was involved in ICA induced cardiomyocyte differentiation, and ROS generation and NF-kappaB nuclear translocation were associated with PIKE activation.

  14. Neuroprotective effect of asiatic acid on rotenone-induced mitochondrial dysfunction and oxidative stress-mediated apoptosis in differentiated SH-SYS5Y cells.

    PubMed

    Nataraj, Jagatheesan; Manivasagam, Thamilarasan; Justin Thenmozhi, Arokiasamy; Essa, Musthafa Mohamed

    2016-02-08

    Parkinson's disease (PD) is a chronic neurodegenerative disease, manifested due to the loss of dopaminergic neurons, which ultimately leads to impaired movement in elderly populations. The pathogenesis of PD is associated with numerous factors including oxidative stress, mitochondrial dysfunction and apoptosis. There is no effective therapy available to cure or halt the progression of this disease still now. Asiatic acid (AA) is a triterpene extracted from Centella asiatica has been reported as an antioxidant and anti-inflammatory agent, that offers neuroprotection against glutamate toxicity. Therefore, in this study, we have investigated the effect of AA in a rotenone (an inhibitor of mitochondrial complex I) induced in vitro model of PD. Following the exposure of SH-SY5Y cells to rotenone, there was a marked overproduction of ROS, mitochondrial dysfunction (as indexed by the decrease in mitochondrial membrane potential) and apoptosis (Hoechst and dual staining, comet assay; expressions of pro-apoptotic and anti-apoptotic indices). Pre-treatment with AA reversed these changes might be due to its antioxidant, mitoprotective and anti-apoptotic properties. However further extensive studies on in vivo models of PD are warranted to prove AA neuroprotective effect before entering into the clinical trial.

  15. Angiotensin II induces differential insulin action in rat skeletal muscle.

    PubMed

    Surapongchai, Juthamard; Prasannarong, Mujalin; Bupha-Intr, Tepmanas; Saengsirisuwan, Vitoon

    2017-03-01

    Angiotensin II (ANGII) is reportedly involved in the development of skeletal muscle insulin resistance. The present investigation evaluated the effects of two ANGII doses on the phenotypic characteristics of insulin resistance syndrome and insulin action and signaling in rat skeletal muscle. Male Sprague-Dawley rats were infused with either saline (SHAM) or ANGII at a commonly used pressor dose (100 ng/kg/min; ANGII-100) or a higher pressor dose (500 ng/kg/min; ANGII-500) via osmotic minipumps for 14 days. We demonstrated that ANGII-100-infused rats exhibited the phenotypic features of non-obese insulin resistance syndrome, including hypertension, impaired glucose tolerance and insulin resistance of glucose uptake in the soleus muscle, whereas ANGII-500-treated rats exhibited diabetes-like symptoms, such as post-prandial hyperglycemia, impaired insulin secretion and hypertriglyceridemia. At the cellular level, insulin-stimulated glucose uptake in the soleus muscle of the ANGII-100 group was 33% lower (P < 0.05) than that in the SHAM group and was associated with increased insulin-stimulated IRS-1 Ser(307) and decreased Akt Ser(473) and AS160 Thr(642) phosphorylation and GLUT-4 expression. However, ANGII-500 infusion did not induce skeletal muscle insulin resistance or impair insulin signaling elements as initially anticipated. Moreover, we found that insulin-stimulated glucose uptake in the ANGII-500 group was accompanied by the enhanced expression of ACE2 and MasR proteins, which are the key elements in the non-classical pathway of the renin-angiotensin system. Collectively, this study demonstrates for the first time that chronic infusion with these two pressor doses of ANGII induced differential metabolic responses at both the systemic and skeletal muscle levels.

  16. Magnetic field induced differential neutron phase contrast imaging

    SciTech Connect

    Strobl, M.; Treimer, W.; Walter, P.; Keil, S.; Manke, I.

    2007-12-17

    Besides the attenuation of a neutron beam penetrating an object, induced phase changes have been utilized to provide contrast in neutron and x-ray imaging. In analogy to differential phase contrast imaging of bulk samples, the refraction of neutrons by magnetic fields yields image contrast. Here, it will be reported how double crystal setups can provide quantitative tomographic images of magnetic fields. The use of magnetic air prisms adequate to split the neutron spin states enables a distinction of field induced phase shifts and these introduced by interaction with matter.

  17. Phenylacetate synergizes with retinoic acid in inducing the differentiation of human neuroblastoma cells.

    PubMed

    Sidell, N; Wada, R; Han, G; Chang, B; Shack, S; Moore, T; Samid, D

    1995-02-08

    Phenylacetate, a natural metabolite of phenylalanine which was originally described as a plant growth hormone, has recently gained attention as a possible differentiation inducer for a variety of human tumor cell types. This interest prompted us to assess the ability of sodium phenylacetate (NaPA) to promote the differentiation of human neuroblastoma cells, both alone and in combination with retinoic acid (RA), a known inducer of neuroblastoma differentiation and maturation. Using the LA-N-5 cell line, we have determined that NaPA can stimulate the differentiation of neuroblastoma cells, as evidenced by dose-dependent inhibition of cell proliferation, neurite outgrowth, increased acetylcholinesterase activity and reduction of N-myc expression. Furthermore, NaPA and RA synergized in inducing differentiation, in that combination treatment resulted in cessation of cell growth along with morphologic and biochemical changes indicative of the loss of malignant properties. We have determined that NaPA can markedly enhance mRNA levels of the nuclear RA receptor-beta (RAR beta) in LA-N-5 cells prior to morphologic or other phenotypic changes induced by this compound. This effect appeared to be distinct from the ability of NaPA to alter tumor cell lipid metabolism via inhibition of protein isoprenylation. Thus among its varied effects on LA-N-5 cells, NaPA appears to interact with the RA pathway at the nuclear level by up-regulating RAR beta expression.

  18. Isorhamnetin, A Flavonol Aglycone from Ginkgo biloba L., Induces Neuronal Differentiation of Cultured PC12 Cells: Potentiating the Effect of Nerve Growth Factor.

    PubMed

    Xu, Sherry L; Choi, Roy C Y; Zhu, Kevin Y; Leung, Ka-Wing; Guo, Ava J Y; Bi, Dan; Xu, Hong; Lau, David T W; Dong, Tina T X; Tsim, Karl W K

    2012-01-01

    Flavonoids, a group of compounds mainly derived from vegetables and herbal medicines, share a chemical resemblance to estrogen, and indeed some of which have been used as estrogen substitutes. In searching for possible functions of flavonoids, the neuroprotective effect in brain could lead to novel treatment, or prevention, for neurodegenerative diseases. Here, different subclasses of flavonoids were analyzed for its inductive role in neurite outgrowth of cultured PC12 cells. Amongst the tested flavonoids, a flavonol aglycone, isorhamnetin that was isolated mainly from the leaves of Ginkgo biloba L. showed robust induction in the expression of neurofilament, a protein marker for neurite outgrowth, of cultured PC12 cells. Although isorhamnetin by itself did not show significant inductive effect on neurite outgrowth of cultured PC12 cells, the application of isorhamnetin potentiated the nerve growth factor- (NGF-)induced neurite outgrowth. In parallel, the expression of neurofilaments was markedly increased in the cotreatment of NGF and isorhamnetin in the cultures. The identification of these neurite-promoting flavonoids could be very useful in finding potential drugs, or food supplements, for treating various neurodegenerative diseases, including Alzheimer's disease and depression.

  19. Effects of dehydration on light-induced conformational changes in bacterial photosynthetic reaction centers probed by optical and differential FTIR spectroscopy.

    PubMed

    Malferrari, Marco; Mezzetti, Alberto; Francia, Francesco; Venturoli, Giovanni

    2013-03-01

    Following light-induced electron transfer between the primary donor (P) and quinone acceptor (Q(A)) the bacterial photosynthetic reaction center (RC) undergoes conformational relaxations which stabilize the primary charge separated state P(+)Q(A)(-). Dehydration of RCs from Rhodobacter sphaeroides hinders these conformational dynamics, leading to acceleration of P(+)Q(A)(-) recombination kinetics [Malferrari et al., J. Phys. Chem. B 115 (2011) 14732-14750]. To clarify the structural basis of the conformational relaxations and the involvement of bound water molecules, we analyzed light-induced P(+)Q(A)(-)/PQ(A) difference FTIR spectra of RC films at two hydration levels (relative humidity r=76% and r=11%). Dehydration reduced the amplitude of bands in the 3700-3550cm(-1) region, attributed to water molecules hydrogen bonded to the RC, previously proposed to stabilize the charge separation by dielectric screening [Iwata et al., Biochemistry 48 (2009) 1220-1229]. Other features of the FTIR difference spectrum were affected by partial depletion of the hydration shell (r=11%), including contributions from modes of P (9-keto groups), and from NH or OH stretching modes of amino acidic residues, absorbing in the 3550-3150cm(-1) range, a region so far not examined in detail for bacterial RCs. To probe in parallel the effects of dehydration on the RC conformational relaxations, we analyzed by optical absorption spectroscopy the kinetics of P(+)Q(A)(-) recombination following the same photoexcitation used in FTIR measurements (20s continuous illumination). The results suggest a correlation between the observed FTIR spectral changes and the conformational rearrangements which, in the hydrated system, strongly stabilize the P(+)Q(A)(-) charge separated state over the second time scale.

  20. Metformin inhibits angiotensin II-induced differentiation of cardiac fibroblasts into myofibroblasts.

    PubMed

    Bai, Jian; Zhang, Na; Hua, Ying; Wang, Bingjian; Ling, Lin; Ferro, Albert; Xu, Biao

    2013-01-01

    Differentiation of cardiac fibroblasts into myofibroblasts is a critical event in the progression of cardiac fibrosis that leads to pathological cardiac remodeling. Metformin, an antidiabetic agent, exhibits a number of cardioprotective properties. However, much less is known regarding the effect of metformin on cardiac fibroblast differentiation. Thus, in the present study, we examined the effect of metformin on angiotensin (Ang) II-induced differentiation of cardiac fibroblasts into myofibroblasts and its underlying mechanism. Adult rat cardiac fibroblasts were stimulated with Ang II (100 nM) in the presence or absence of metformin (10-200 µM). Ang II stimulation induced the differentiation of cardiac fibroblasts into myofibroblasts, as indicated by increased expression of α-smooth muscle actin (α-SMA) and collagen types I and III, and this effect of Ang II was inhibited by pretreatment of cardiac fibroblasts with metformin. Metformin also decreased Ang II-induced reactive oxygen species (ROS) generation in cardiac fibroblasts via inhibiting the activation of the PKC-NADPH oxidase pathway. Further experiments using PKC inhibitor calphostin C and NADPH oxidase inhibitor apocynin confirmed that inhibition of the PKC-NADPH oxidase pathway markedly attenuated Ang II-induced ROS generation and myofibroblast differentiation. These data indicate that metformin inhibits Ang II-induced myofibroblast differentiation by suppressing ROS generation via the inhibition of the PKC-NADPH oxidase pathway in adult rat cardiac fibroblasts. Our results provide new mechanistic insights regarding the cardioprotective effects of metformin and provide an efficient therapeutic strategy to attenuate cardiac fibrosis.

  1. Toddaculin, a natural coumarin from Toddalia asiatica, induces differentiation and apoptosis in U-937 leukemic cells.

    PubMed

    Vázquez, Ramiro; Riveiro, María E; Vermeulen, Mónica; Mondillo, Carolina; Coombes, Philip H; Crouch, Neil R; Ismail, Fathima; Mulholland, Dulcie A; Baldi, Alberto; Shayo, Carina; Davio, Carlos

    2012-06-15

    Chemotherapeutics represent the main approach for the treatment of leukemia. However, the occurrence of adverse side effects and the complete lack of effectiveness in some cases make it necessary to develop new drugs. As part of our screening program to evaluate the potential chemotherapeutic effect of natural coumarins, we investigated the anti-leukemic activities of a series of six prenylated coumarins isolated from the stem bark of Toddalia asiatica (Rutaceae). Among these, 6-(3-methyl-2-butenyl)-5,7-dimethoxycoumarin (toddaculin) displayed the most potent cytotoxic and anti-proliferative effects in U-937 cells. To determine whether these effects resulted from induction of cell death or differentiation, we further evaluated the expression of several apoptosis and maturation markers. Interestingly, while toddaculin at 250 μM was able to induce apoptosis in U-937 cells, involving decreased phosphorylation levels of ERK and Akt, 50 μM toddaculin exerted differentiating effects, inducing both the capacity of U-937 cells to reduce NBT and the expression of differentiation markers CD88 and CD11b, but no change in p-Akt or p-ERK levels. Taken together, these findings indicate that toddaculin displays a dual effect as a cell differentiating agent and apoptosis inducer in U-937 cells, suggesting it may serve as a pharmacological prototype for the development of novel anti-leukemic agents.

  2. Differential anti-inflammatory and anti-oxidative effects of dexamethasone and N-acetylcysteine in endotoxin-induced lung inflammation

    PubMed Central

    Rocksén, D; Lilliehöök, B; Larsson, R; Johansson, T; Bucht, A

    2000-01-01

    Inhalation of bacterial endotoxin induces an acute inflammation in the lower respiratory tract. In this study, the anti-inflammatory effects of the anti-oxidant N-acetylcysteine (NAC) and the glucocorticoid dexamethasone were investigated in mice exposed to aerosolized endotoxin (lipopolysaccharide (LPS)). Powerful reduction of neutrophils in bronchoalveolar lavage fluid (BALF) was obtained by a single i.p. injection of dexamethasone (10 mg/kg), whereas treatment with NAC only resulted in reduction of neutrophils when administered at a high dose (500 mg/kg). Measurement of cytokine and chemokine expression in lung tissue revealed a significant decrease of tumour necrosis factor-alpha, IL-1α, IL-1β, IL-6, IL-12p40, and MIP-1α mRNA when mice where treated with dexamethasone but not when treated with NAC. Analysis of oxidative burst demonstrated a remarkable reduction of oxygen radicals in BALF neutrophils after treatment with dexamethasone, whereas the effect of NAC was not significantly different from that in untreated animals. In conclusion, dexamethasone exerted both anti-inflammatory and anti-oxidative effects in acute airway inflammation, probably by blocking early events in the inflammatory cascade. In contrast, treatment with NAC resulted in a weak reduction of the inflammatory response but no inhibition of proinflammatory cytokines or reduction of oxidative burst in neutrophils. These results demonstrate dramatic differences in efficiency and also indicate that the two drugs have different actions. Combined treatment with NAC and dexamethasone revealed an additive action but no synergy was observed. PMID:11091282

  3. Monocyte cell surface glycosaminoglycans positively modulate IL-4-induced differentiation toward dendritic cells.

    PubMed

    den Dekker, Els; Grefte, Sander; Huijs, Tonnie; ten Dam, Gerdy B; Versteeg, Elly M M; van den Berk, Lieke C J; Bladergroen, Bellinda A; van Kuppevelt, Toin H; Figdor, Carl G; Torensma, Ruurd

    2008-03-15

    IL-4 induces the differentiation of monocytes toward dendritic cells (DCs). The activity of many cytokines is modulated by glycosaminoglycans (GAGs). In this study, we explored the effect of GAGs on the IL-4-induced differentiation of monocytes toward DCs. IL-4 dose-dependently up-regulated the expression of DC-specific ICAM-3-grabbing nonintegrin (DC-SIGN), CD80, CD206, and CD1a. Monocytes stained positive with Abs against heparan sulfate (HS) and chondroitin sulfate (CS) B (CSB; dermatan sulfate), but not with Abs that recognize CSA, CSC, and CSE. Inhibition of sulfation of monocyte/DC cell surface GAGs by sodium chlorate reduced the reactivity of sulfate-recognizing single-chain Abs. This correlated with hampered IL-4-induced DC differentiation as evidenced by lower expression of DC-SIGN and CD1a and a decreased DC-induced PBL proliferation, suggesting that sulfated monocyte cell surface GAGs support IL-4 activity. Furthermore, removal of cell surface chondroitin sulfates by chondroitinase ABC strongly impaired IL-4-induced STAT6 phosphorylation, whereas removal of HS by heparinase III had only a weak inhibitory effect. IL-4 bound to heparin and CSB, but not to HS, CSA, CSC, CSD, and CSE. Binding of IL-4 required iduronic acid, an N-sulfate group (heparin) and specific O sulfates (CSB and heparin). Together, these data demonstrate that monocyte cell surface chondroitin sulfates play an important role in the IL-4-driven differentiation of monocytes into DCs.

  4. Feeding and Reward Are Differentially Induced by Activating GABAergic Lateral Hypothalamic Projections to VTA

    PubMed Central

    Barbano, M. Flavia; Wang, Hui-Ling; Morales, Marisela

    2016-01-01

    Electrical stimulation of the lateral hypothalamus (LH) has two motivational effects: long trains of stimulation induce drive-like effects such as eating, and short trains are rewarding. It has not been clear whether a single set of activated fibers subserves the two effects. Previous optogenetic stimulation studies have confirmed that reinforcement and induction of feeding can each be induced by selective stimulation of GABAergic fibers originating in the bed nucleus of the LH and projecting to the ventral tegmental area (VTA). In the present study we determined the optimal stimulation parameters for each of the two optogenetically induced effects in food-sated mice. Stimulation-induced eating was strongest with 5 Hz and progressively weaker with 10 and 20 Hz. Stimulation-induced reward was strongest with 40 Hz and progressively weaker with lower or higher frequencies. Mean preferred duration for continuous 40 Hz stimulation was 61.6 s in a “real-time” place preference task; mean preferred duration for 5 Hz stimulation was 45.6 s. The differential effects of high- and low-frequency stimulation of this pathway seem most likely to be due to differential effects on downstream targets. SIGNIFICANCE STATEMENT Our study reports that the eating and the reward induced by optogenetic stimulation of a previously identified GABAergic projection from the lateral hypothalamus to the ventral tegmental area are differentially affected by low- and high-frequency stimulation, respectively. This suggests a way that stimulation of the same pathway can have very different motivational effects on behavior, inducing a drive state (usually thought to be aversive) under one condition and inducing the rewarding state under another. This offers an insight into what has been called the “drive-reward paradox”: why would an animal work for stimulation that established an apparent drive state? PMID:26961951

  5. Resistance of differentiating spermatogonia to radiation-induced apoptosis and loss in p53-deficient mice.

    PubMed

    Hasegawa, M; Zhang, Y; Niibe, H; Terry, N H; Meistrich, M L

    1998-03-01

    The effect of the p53 gene on the survival of mouse testicular cells was evaluated by analysis of degenerating and terminal transferase-mediated end labeling (TUNEL)-positive cells and the subsequent production of further differentiated progeny. In p53 null mice, in contrast to wild-type mice, radiation induced negligible levels of degenerating or TUNEL-positive differentiating spermatogonia within 24 h. This was correlated with higher production of differentiated progeny of the differentiating spermatogonia in p53 null mice. Contrary to the differentiating spermatogonia, the stem spermatogonia of p53 null mice produced fewer differentiated progeny after irradiation than did the stem cells of wild-type mice. We conclude that, because the degeneration and TUNEL positivity of the differentiating spermatogonia in mice of different genotypes were correlated with each other and were dependent on p53, this process is indeed apoptosis. In the differentiating spermatogonia, p53-dependent apoptosis accounted for the bulk of the loss of their progeny after irradiation. Furthermore, whereas the differentiating spermatogonia died by apoptosis that was dependent on p53, the stem spermatogonia, which are more radioresistant, did not.

  6. [Inhibition of NHE1 promotes hypoxia-induced differentiation of K562 leukemic cells].

    PubMed

    Jin, Wei-Na; Wang, Jian; Chang, Guo-Qiang; Lin, Ya-Ni; Wang, Li-Hong; Li, Hua-Wen; Gao, Wei; Li, Qing-Hua; Pang, Tian-Xiang

    2011-06-01

    This study was purposed to investigate the effect of hypoxia microenvironment on K562 leukemic cell differentiation, and characteristics of NHE1 involvement in this process. The K562 cells were treated with hypoxia-mimical agent CoCl₂ or under actual hypoxia culture, and the specific NHE1 inhibitor Cariporide was used to inhibit NHE1 activity. The fluorescent probe BCECF was used for pH(i) measurements. Gene expression was analyzed by RT-PCR. The morphological characteristics was determined by Wright's staining. Signaling pathways were detected by Western blot using phosphospecific antibodies. The results indicated that the hypoxia or mimetic hypoxia favored K562 cells differentiation with up-regulation of C/EBPα. Moreover, treatment with Cariporide under hypoxia synergistically enhanced leukemia cell differentiation. Treatment with Cariporide increased levels of phosphorylated ERK5 and P38 mitogen-activated protein kinase (MAPK). It is concluded that the hypoxia or mimetic hypoxia can induce the differentiation of K562 cells, the inhibition of NHE1 activity can promote the hypoxia-induced K562 cell differentiation. The enhancement of hypoxia-induced K562 differentiation by Cariporide via MAPK signal pathway suggests a possible therapeutic target of NHE1 under hypoxia microenvironment in the treatment of leukemias.

  7. Adverse effects of differential parental attention1

    PubMed Central

    Sajwaj, Thomas E.; Pinkston, Susan; Cordua, Glenn; Jackson, Carolyn; Herbert, Emily W.; Pinkston, Elsie M.; Hayden, M. Loeman

    1973-01-01

    In two independent parent training projects (Kansas and Mississippi), mothers of deviant young children were observed to follow almost all child behaviors with attention. The mothers were then trained to use differential attention procedures to increase their child's appropriate behaviors and to decrease deviant behaviors. Contrary to expectations, the differential attention procedure produced substantial increases in deviant behavior for four of the children. This adverse effect was maintained over many sessions and was replicated in single organism, reversal designs. A fifth child showed no change. A sixth child showed some improvement. However, this effect was not recovered in a second application of differential attention, and the child became worse. The results underline the importance of subject generality in applied behavior analysis and strongly suggest that service programs using operant techniques must carefully evaluate their effects on behavior. PMID:16795386

  8. Laser-induced differential normalized fluorescence method for cancer diagnosis

    DOEpatents

    Vo-Dinh, T.; Panjehpour, M.; Overholt, B.F.

    1996-12-03

    An apparatus and method for cancer diagnosis are disclosed. The diagnostic method includes the steps of irradiating a tissue sample with monochromatic excitation light, producing a laser-induced fluorescence spectrum from emission radiation generated by interaction of the excitation light with the tissue sample, and dividing the intensity at each wavelength of the laser-induced fluorescence spectrum by the integrated area under the laser-induced fluorescence spectrum to produce a normalized spectrum. A mathematical difference between the normalized spectrum and an average value of a reference set of normalized spectra which correspond to normal tissues is calculated, which provides for amplifying small changes in weak signals from malignant tissues for improved analysis. The calculated differential normalized spectrum is correlated to a specific condition of a tissue sample. 5 figs.

  9. Laser-induced differential normalized fluorescence method for cancer diagnosis

    DOEpatents

    Vo-Dinh, Tuan; Panjehpour, Masoud; Overholt, Bergein F.

    1996-01-01

    An apparatus and method for cancer diagnosis are disclosed. The diagnostic method includes the steps of irradiating a tissue sample with monochromatic excitation light, producing a laser-induced fluorescence spectrum from emission radiation generated by interaction of the excitation light with the tissue sample, and dividing the intensity at each wavelength of the laser-induced fluorescence spectrum by the integrated area under the laser-induced fluorescence spectrum to produce a normalized spectrum. A mathematical difference between the normalized spectrum and an average value of a reference set of normalized spectra which correspond to normal tissues is calculated, which provides for amplifying small changes in weak signals from malignant tissues for improved analysis. The calculated differential normalized spectrum is correlated to a specific condition of a tissue sample.

  10. Phenotypic differentiation of Streptococcus pyogenes populations is induced by recombination-driven gene-specific sweeps

    PubMed Central

    Bao, Yun-Juan; Shapiro, B. Jesse; Lee, Shaun W.; Ploplis, Victoria A.; Castellino, Francis J.

    2016-01-01

    Genomic recombination plays an important role in driving adaptive evolution and population differentiation in bacteria. However, controversy exists as to the effects of recombination on population diversity and differentiation, i.e., recombination is frequent enough to sweep through the population at selected gene loci (gene-specific sweeps), or the recombination rate is low without interfering genome-wide selective sweeps. Observations supporting either view are sparse. Pathogenic bacteria causing infectious diseases are promising candidates to provide observations of recombination. However, phenotype-associated differentiations are usually vague among them due to diverse disease manifestations. Here we report a population genomic study of the group A Streptococcus pyogenes (GAS), a human pathogen with highly recombining genomes. By employing a genome-wide association study on single nucleotide polymorphisms (SNPs), we demonstrate a phenotypic differentiation of GAS, represented by separate clustering of two sublineages associated with niche-specific infections, i.e., skin infection and pharyngitis-induced acute rheumatic fever. By quantifying SNPs associated with the differentiation in a statistical and phylogenetic context, we propose that the phenotype-associated differentiation arose through recombination-driven gene-specific sweeps, rather than genome-wide sweeps. Our work provides a novel paradigm of phenotype-associated differentiation induced by gene-specific sweeps in a human pathogen and has implications for understanding of driving forces of bacterial evolution. PMID:27821851

  11. Blockade of rapid versus prolonged extracellularly regulated kinase 1/2 activation has differential effects on insulin-induced gene expression.

    PubMed

    Keeton, Adam B; Bortoff, Katherine D; Franklin, J Lee; Messina, Joseph L

    2005-06-01

    In the present work, insulin's regulation of expression of activating transcription factor 3 (ATF-3), the putative transcription factor proline-rich induced protein (Pip)92, and insulin-inducible gene-1 (Insig-1) (an ER resident protein involved in regulation of sterol-responsive element-binding protein 1 activation) have been examined in a liver-derived cell line (rat H4IIE hepatoma cells). We report that: 1) insulin-induced transcription of ATF-3, Pip92, and Insig-1 required MEK-ERK activation; 2) insulin-induced transcription of ATF-3 and Pip92 reached maximum levels within 15 min and was blocked by wortmannin but not LY294002; 3) in contrast, the maximum level of insulin-induced transcription of Insig-1 was delayed and was not blocked by either wortmannin or LY294002; 4) insulin activated ERK1/2 in two distinct phases, a rapid peak and a later plateau; 5) the delayed plateau phase of insulin-induced ERK1/2 activation was partially phosphatidylinositol 3-OH-kinase dependent; and 6) however, the rapid, insulin-induced peak of ERK1/2 activation was blocked by wortmannin but not LY294002.

  12. Cytokine-induced macrophage differentiation: a tale of 2 genes.

    PubMed

    Winston, B W; Krein, P M; Mowat, C; Huang, Y

    1999-12-01

    Macrophages are versatile cells found in every tissue in the body. They must perform a number of diverse cellular functions that allow them to kill invading micro-organisms and neoplastic cells as well as produce growth factors involved in wound healing. Macrophages that develop these diverse functions arise from a common precursor. By a process of selective adaptation, the common precursor monocyte/macrophage differentiates into a distinctive macrophage with a different and specific phenotype, characterized by the expression of a specific set of gene products. The local environment plays a critical role in shaping or directing the pattern or pathway of macrophage differentiation. The authors have focused on 2 specific macrophage differentiation pathways in a murine bone marrow-derived macrophage model. One pathway is believed to play a role in wound repair and is characterized by the induction of insulin-like growth factor-1 (IGF-I). The second pathway is involved in macrophage cytocidal activation and is characterized by the induction of the inducible form of nitric oxide synthase (iNOS). The pleotropic cytokine tumour necrosis factor-alpha (TNF-alpha) appears to mediate macrophage differentiation along both of these pathways. Interferon-gamma (IFN-gamma), however, appears to act as a molecular switch. In the presence of IFN-gamma, stimulation of macrophages with TNF-alpha results in macrophage differentiation along a pathway in which iNOS is expressed, whereas, in the absence of IFN-gamma, stimulation of macrophages with TNF-alpha results in differentiation along a pathway in which IGF-I is expressed. The authors focus on some of the molecular events involved in TNF-alpha and IFN-gamma signal transduction and the regulation of iNOS and IGF-I genes in macrophages.

  13. Combined activity of interleukin-1 alpha or TNF-alpha and doxorubicin on multidrug resistant cell lines: evidence that TNF and DXR have synergistic antitumor and differentiation-inducing effects.

    PubMed

    Borsellino, N; Crescimanno, M; Flandina, C; Flugy, A; D'Alessandro, N

    1994-01-01

    We report on the antiproliferative effects that interleukin-1 alpha (IL-1) or TNF-alpha (TNF) in combination with doxorubicin (DXR) exert on DXR-sensitive (B16 melanoma, Friend, K562 and CCRF/CEM leukemias) and -resistant (B16-DXR, FLC-DXR, K562-DXR) cell lines in vitro. Multidrug resistance (MDR) of the latter lines entails cross-resistance to vincristine and overexpression of P-glycoprotein. Il-1 showed only a very marginal growth inhibitory activity and the effects of its combination with DXR were essentially additive in all the cell lines, except in chemosensitive B16, where a slight synergism occurred. TNF demonstrated greater antiproliferative activity in the MDR B16 and Friend tumors than in their parent variants. The combination of TNF and DXR produced synergistic growth inhibition in B16, K562 and, particularly, also in the MDR sublines of these two tumors. In addition, TNF and DXR induced synergistically erythroid differentiation in K562 and multidirectional differentiation in K562-DXR. The synergism was critically schedule-dependent in that it was achieved only when DXR application preceded or was simultaneous with that of TNF. Finally, TNF did not modify drug accumulation and retention in the cells. Our present findings stress especially the fact that DXR and TNF may exert useful antitumor synergism even in MDR lines; however, it is not likely that their interaction will occur at the specific MDR process level.

  14. The Inhibitory Effect of Angelica tenuissima Water Extract on Receptor Activator of Nuclear Factor-Kappa-B Ligand-Induced Osteoclast Differentiation and Bone Resorbing Activity of Mature Osteoclasts.

    PubMed

    Ahn, Sung-Jun; Baek, Jong Min; Cheon, Yoon-Hee; Park, Sun-Hyang; Lee, Myeung Su; Oh, Jaemin; Kim, Ju-Young

    2015-01-01

    Angelica tenuissima has been traditionally used in oriental medicine for its therapeutic effects in headache, toothache, and flu symptoms. It also exerts anti-inflammatory activity via the inhibition of the expression of cyclooxygenase-2 (COX-2). However, the effect of Angelica tenuissima on osteoclast differentiation has not been identified until recently. In this study, we first confirmed that Angelica tenuissima water extract (ATWE) significantly interrupted the formation of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells (MNCs) in a dose-dependent manner without any cytotoxicity. Next, we clarified the underlying mechanisms linking the suppression effects of ATWE on the receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis. At the molecular level, ATWE induced the dephosphorylation of c-Jun N-terminal kinase (JNK) and Akt and decreased the degradation of IκB in RANKL-dependent early signaling pathways. Subsequently, ATWE caused impaired activation of the protein and mRNA levels of c-Fos and nuclear factor of activated T cell c1 (NFATc1). Moreover, the disassembly of filamentous actin (F-actin) ring and anti-resorptive activity of mature osteoclasts were triggered by ATWE treatment. Although ATWE did not enhance osteogenesis in primary osteoblasts, our results showed that ATWE is a potential candidate for anti-resorptive agent in osteoporosis, a common metabolic bone disorder.

  15. Endurance exercise regimens induce differential effects on brain-derived neurotrophic factor, synapsin-I and insulin-like growth factor I after focal ischemia.

    PubMed

    Ploughman, M; Granter-Button, S; Chernenko, G; Tucker, B A; Mearow, K M; Corbett, D

    2005-01-01

    The optimal amount of endurance exercise required to elevate proteins involved in neuroplasticity during stroke rehabilitation is not known. This study compared the effects of varying intensities and durations of endurance exercise using both motorized and voluntary running wheels after endothelin-I-induced focal ischemia in rats. Hippocampal levels of brain-derived neurotrophic factor, insulin-like growth factor I and synapsin-I were elevated in the ischemic hemisphere even in sedentary animals suggesting an intrinsic restorative response 2 weeks after ischemia. In the sensorimotor cortex and the hippocampus of the intact hemisphere, one episode of moderate walking exercise, but not more intense running, resulted in the greatest increases in levels of brain-derived neurotrophic factor and synapsin-I. Exercise did not increase brain-derived neurotrophic factor, insulin-like growth factor I or synapsin-I in the ischemic hemisphere. In voluntary running animals, both brain and serum insulin-like growth factor I appeared to be intensity dependent and were associated with decreasing serum levels of insulin-like growth factor I and increasing hippocampal levels of insulin-like growth factor I in the ischemic hemisphere. This supports the notion that exercise facilitates the movement of insulin-like growth factor I across the blood-brain barrier. Serum corticosterone levels were elevated by all exercise regimens and were highest in rats exposed to motorized running of greater speed or duration. The elevation of corticosterone did not seem to alter the expression of the proteins measured, however, graduated exercise protocols may be indicated early after stroke. These findings suggest that relatively modest exercise intervention can increase proteins involved in synaptic plasticity in areas of the brain that likely subserve motor relearning after stroke.

  16. Inhibitory effect of Phalaenopsis orchid extract on WNT1-induced immature melanocyte precursor differentiation in a novel in vitro solar lentigo model.

    PubMed

    Yamada, Takaaki; Hasegawa, Seiji; Inoue, Yu; Kunita, Mayumi; Ohsumi, Kazuhisa; Sakaida, Tsutomu; Yashiro, Youichi; Nakata, Satoru

    2016-07-01

    Recently, it has been reported that increased expression of WNT1 accelerates the differentiation of melanocyte stem cells (McSCs) in solar lentigines (SLs), hyperpigmented maculae commonly seen on sun-exposed areas of the skin. In this study, to establish an in vitro SL model, human epidermal squamous carcinoma cell line HSC-1, which expresses higher levels of WNT1 than normal human epidermal keratinocytes, was co-cultured with early passage normal human epidermal melanocytes (NHEMs) as an in vitro McSC model. As a result, mRNA expression levels of melanocyte differentiation-related genes MITF and TYR in NHEMs were significantly increased by co-culturing with HSC-1 cells. Furthermore, Phalaenopsis orchid extract (Phex) inhibited McSCs differentiation by suppressing WNT1 expression via down-regulation of DLX2, a transcriptional activator of WNT1, in HSC-1 cells. Therefore, our finding suggested that extracts such as Phex, which suppresses WNT1 expression, may be useful as a novel treatment of SLs.

  17. Regulation of RANKL-induced osteoclastic differentiation by vascular cells.

    PubMed

    Tintut, Yin; Abedin, Moeen; Cho, John; Choe, Andrea; Lim, Jina; Demer, Linda L

    2005-08-01

    Vascular calcification is a regulated process of biomineralization resembling osteogenesis. Many bone-related factors, including resorptive osteoclast-like cells, although in low abundance, have been found in calcified atherosclerotic lesions. The regulatory mechanisms governing them in the vasculature, however, are not clear. Previously, we found that calcifying vascular cells (CVC), a subpopulation of bovine aortic smooth muscle cells (BASMC), undergo osteoblastic differentiation and form mineralized nodules. Since osteoblasts and marrow stromal preosteoblasts regulate osteoclastic differentiation in bone, we hypothesized that vascular cells also regulate differentiation of osteoclastic precursors in the artery wall. Peripheral blood monocytes, which are osteoclast precursors, were co-cultured with CVC or BASMC. Results showed that monocytes co-cultured with both of the vascular cells yielded fewer resorption pits than monocytes cultured alone. Furthermore, monocytes co-cultured with CVC had fewer resorption pits than those co-cultured with BASMC. Conditioned media from the vascular cells also inhibited resorptive activity of monocytes suggesting that the inhibitory effect was mediated in part by soluble factors. Compared with BASMC, CVC had lower mRNA expression for osteopontin, which promotes osteoclast attachment, but greater mRNA expression for the soluble inhibitory cytokine, IL-18. Increased osteoclastic differentiation was observed when neutralizing antibody to IL-18 receptor was added to the cultures of preosteoclasts with CVC conditioned media. Osteoprotegerin, another osteoclast inhibitory cytokine, was expressed at similar levels in both cultures. These results suggest that vascular cells inhibit osteoclastic differentiation, and that CVC have greater inhibitory effects than BASMC.

  18. Differential effects of fibroblast growth factor and tumor promoters on the initiation and maintenance of adipocyte differentiation

    PubMed Central

    1989-01-01

    Fibroblast growth factor (FGF) has been shown to inhibit the differentiation of myogenic and adipogenic cell lines without inducing a proliferative response. We have previously shown that agents capable of activating protein kinase C (PKC), such as FGF and the phorbol ester tetradecanoyl phorbol-13-acetate (TPA), inhibit the differentiation of the adipogenic cell line TA1, as measured by the rapid loss of adipocyte-specific RNAs. We report here that the treatment of fully differentiated TA1 adipocytes with FGF at 10 ng/ml induces the reversal of adipocyte differentiation, even in cells where PKC activity has been down-regulated by TPA pretreatment. In contrast, TPA or lower concentrations of FGF (1 ng/ml), both effective inducers of c-fos RNA in adipocytes, fail to reverse adipocyte differentiation. The adipocytes, however, will extinguish differentiation-specific functions in response to TPA by the addition of a calcium ionophore. Therefore, we propose that there are two FGF-sensitive pathways in TA1 cells: one responsible for the initiation of differentiation (TPA sensitive) and another required for maintenance of the adipose phenotype (TPA insensitive). These results suggest that activation of two distinct signaling pathways--one PKC and calcium dependent, the other FGF activated but PKC independent--are capable of inhibiting the biochemical events responsible for the maintenance of adipocyte differentiation. PMID:2507555

  19. Differential effects of lenalidomide during plasma cell differentiation

    PubMed Central

    Jourdan, Michel; Cren, Maïlys; Schafer, Peter; Robert, Nicolas; Duperray, Christophe; Vincent, Laure; Ceballos, Patrice; Cartron, Guillaume; Rossi, Jean-François; Moreaux, Jérôme; Chopra, Rajesh; Klein, Bernard

    2016-01-01

    Thalidomide, lenalidomide and pomalidomide have greatly improved the outcome of patients with multiple myeloma. However, their effects on plasma cells, the healthy counterpart of myeloma cells, are unknown. Here, we investigated lenalidomide effects on normal human plasma cell generation using an in vitro model. Lenalidomide inhibited the generation of pre-plasmablasts and early plasma cells, while it moderately affected plasmablast production. It also reduced the expression level of Ikaros, Aiolos, and IRF4 transcription factors, in plasmablasts and early plasma cells. This suggests that their differential sensitivity to lenalidomide is not due to a difference in Ikaros or Aiolos degradation. Lenalidomide also inhibited long-lived plasma cell generation, but did not impair their long-term survival once generated. This last observation is in agreement with the finding that lenalidomide treatment for 3-18 months did not affect the bone marrow healthy plasma cell count in allografted patients with multiple myeloma. Our findings should prompt to investigate whether lenalidomide resistance in patients with multiple myeloma could be associated with the emergence of malignant plasmablasts or long-lived plasma cells that are less sensitive to lenalidomide. PMID:27057635

  20. Differential effects of lenalidomide during plasma cell differentiation.

    PubMed

    Jourdan, Michel; Cren, Maïlys; Schafer, Peter; Robert, Nicolas; Duperray, Christophe; Vincent, Laure; Ceballos, Patrice; Cartron, Guillaume; Rossi, Jean-François; Moreaux, Jérôme; Chopra, Rajesh; Klein, Bernard

    2016-05-10

    Thalidomide, lenalidomide and pomalidomide have greatly improved the outcome of patients with multiple myeloma. However, their effects on plasma cells, the healthy counterpart of myeloma cells, are unknown. Here, we investigated lenalidomide effects on normal human plasma cell generation using an in vitro model. Lenalidomide inhibited the generation of pre-plasmablasts and early plasma cells, while it moderately affected plasmablast production. It also reduced the expression level of Ikaros, Aiolos, and IRF4 transcription factors, in plasmablasts and early plasma cells. This suggests that their differential sensitivity to lenalidomide is not due to a difference in Ikaros or Aiolos degradation. Lenalidomide also inhibited long-lived plasma cell generation, but did not impair their long-term survival once generated. This last observation is in agreement with the finding that lenalidomide treatment for 3-18 months did not affect the bone marrow healthy plasma cell count in allografted patients with multiple myeloma. Our findings should prompt to investigate whether lenalidomide resistance in patients with multiple myeloma could be associated with the emergence of malignant plasmablasts or long-lived plasma cells that are less sensitive to lenalidomide.

  1. Differential diagnosis of food protein-induced enterocolitis syndrome

    PubMed Central

    Fiocchi, Alessandro; Claps, Alessia; Dahdah, Lamia; Brindisi, Giulia; Dionisi-Vici, Carlo; Martelli, Alberto

    2014-01-01

    Purpose of review To assess all the possible differential diagnosis of food protein-induced enterocolitis syndrome (FPIES), both in acute and chronic presentation, reviewing the data reported in published studies. Recent findings There is an increase of reported cases of FPIES in recent years. As the disease presents with nonspecific symptoms, it can be misunderstood in many ways. The differential diagnosis includes, in acute presentations, the following: sepsis, other infectious diseases, acute gastrointestinal episodes, surgical emergencies, food allergies. In its chronic forms, FPIES may mimic malabsorption syndromes, metabolic disorders, primary immunodeficiencies, neurological conditions, coagulation defects, and other types of non-IgE-mediated food allergy. Summary A thorough clinical evaluation, including symptoms, signs, and laboratory findings, is necessary to lead the clinicians toward the diagnosis of FPIES. The major reason for delayed diagnosis appears to be the lack of knowledge of the disease. PMID:24739227

  2. Effects of Induced Astigmatism.

    ERIC Educational Resources Information Center

    Schubert, Delwyn G.; Walton, Howard N.

    1968-01-01

    The relationship of astigmatism to reading and the possible detrimental effects it might have on reading were investigated. The greatest incidence of astigmatism was for the with-the-rule type ranging from .50 to 1.00 diopter. This type of astigmatism was induced in 35 seniors from the Los Angeles College of Optometry by placing cylindrical lenses…

  3. Differential Effects of Science Study Questions.

    ERIC Educational Resources Information Center

    Holliday, William G.; And Others

    The purpose of this study was to investigate the differential effects on low and high verbal students of verbatim study questions adjunct to a text describing science concepts. The sample consisted of 217 eighth grade students enrolled in twelve Calgary (Alberta, Canada) schools. Materials developed for the study included an introduction to the…

  4. Substrate Induced Osteoblast-Like Differentiation of Stromal Stem Cells

    NASA Astrophysics Data System (ADS)

    Belizar, Jacqueline; Glaser, Reena; Hung, Matthew; Simon, Marcia; Jurukovski, Vladimir; Rafailovich, Miriam; Shih, Alice

    2009-03-01

    We have demonstrated that Adipose-derived stem cells (ASCs) can be induced to biomineralize on a polybutadiene (PB) coated Si substrate. The cells began to generate calcium phosphate deposits after a five-day incubation period in the absence of dexamethasone. Control cells plated on tissue culture PS culture dish (TCP) did not biomineralize. In addition, the biomineralizing culture retained proliferative cells In order to determine whether the induction was transient, we transferred the cells exposed to polybutadiene after 14 and 28-day incubation periods to TCP dishes. These cells continued to biominerlize. Genetic testing is underway which will determine whether differentiation is maintained after transfer.

  5. Ethacrynic acid and 1 alpha,25-dihydroxyvitamin D3 cooperatively inhibit proliferation and induce differentiation of human myeloid leukemia cells.

    PubMed

    Makishima, M; Honma, Y

    1996-09-01

    The active form of vitamin D, 1 alpha,25-dihydroxyvitamin D3 (VD3), inhibits proliferation and induces differentiation of leukemia cells, but its clinical use is limited by the adverse effect of hypercalcemia. In this study we found that the loop diuretic ethacrynic acid, which is used to treat hypercalcemia, enhanced the differentiation of human leukemia cells induced by VD3. Ethacrynic acid alone inhibited the proliferation of human promyelocytic HL-60 cells while only slightly increasing differentiation markers such as nitroblue tetrazolium (NBT)-reducing and lysozyme activities. Ethacrynic acid effectively enhanced the growth-inhibiting action of VD3. In the presence of ethacrynic acid, VD3 increased the NBT-reducing and lysozyme activities and the CD11b expression of HL-60 cells more effectively than VD3 alone. Other loop diuretics, furosemide and bumetanide, also enhanced the differentiation of HL-60 cells induced by VD3, but to a lesser extent than ethacrynic acid. The differentiation of HL-60 cells induced by all-trans retinoic acid, dimethyl sulfoxide or phorbol-12-myristate 13-acetate was also enhanced by ethacrynic acid with increasing NBT-reducing and lysozyme activities and the expression of CD11b or CD14 surface antigen. Morphologically, ethacrynic acid enhanced the monocytic differentiation of HL-60 cells induced by VD3 and phorbol ester and the granulocytic differentiation by retinoic acid and dimethyl sulfoxide. Other human myelomonocytic leukemia ML-1, U937, P39/TSU and P31/FUJ cells were induced to differentiate by VD3 and this was also enhanced by ethacrynic acid. The long-term culture of HL-60 cells showed that ethacrynic acid plus VD3 induced the complete growth arrest of HL-60 cells. Therefore ethacrynic acid, which is used to treat hypercalcemia, enhanced the proliferation-inhibiting and differentiation-inducing activities of VD3 and the combination of ethacrynic acid and VD3 may be useful in therapy for myeloid leukemia.

  6. Differential effects of chronic overload-induced muscle hypertrophy on mTOR and MAPK signaling pathways in adult and aged rats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We examined activation of the mammalian target of rapamycin (mTOR) and mitogen-activated protein kinase (MAPK) signaling pathways in adult (Y; 6 mo old; n = 16) and aged (O; 30 mo old; n = 16) male rats (Fischer 344 x Brown Norway) subjected to chronic overload-induced muscle hypertrophy of the plan...

  7. Effect of resveratrol on proliferation and differentiation of embryonic cardiomyoblasts

    SciTech Connect

    Leong, C.-W.; Wong, C.H.; Lao, S.-C.; Leong, Emilia Conceicao; Lao, Iok Fong; Law, Patrick Tik Wan; Fung, Kwok Pui; Tsang, Kam Sze; Waye, Mary Miu-Yee; Tsui, Stephen Kwok-Wing; Wang Yitao . E-mail: YTWang@umac.mo; Lee, Simon Ming-Yuen . E-mail: simonlee@umac.mo

    2007-08-17

    Resveratrol (trans-3,5,4'-trihydroxystilbene), a polyphenolic compound found largely in the skins of red grapes, has been used as a nutritional supplement or an investigational new drug for prevention of cardiovascular diseases. Previous reports showed that resveratrol had a protective effect against oxidative agent-induced cell injury. Our studies indicate that resveratrol plays a role in the differentiation of cardiomyoblasts. The cardiomyoblast cell line, H9c2, was exposed to 30-120 {mu}M resveratrol for up to 5 days. Resveratrol inhibits cardiomyoblast proliferation without causing cells injury. Moreover, resveratrol treatment modulated the differentiation of morphological characteristics including elongation and cell fusion in cardiomyoblasts. Proliferation and differentiation of H9c2 cells were further revealed by measurement of the mRNA expression of a cell cycle marker (CDK2), a differentiation marker (myogenin), and a contractile apparatus protein (MLC-2). Gene expression analysis revealed that resveratrol promoted entry into cell cycle arrest but extended the myogenic differentiation progress. These results have implications for the role of resveratrol in modulating cell cycle control and differentiation in cardiomyoblasts.

  8. Inducing endoderm differentiation by modulating mechanical properties of soft substrates.

    PubMed

    Jaramillo, Maria; Singh, Satish S; Velankar, Sachin; Kumta, Prashant N; Banerjee, Ipsita

    2015-01-01

    Early embryonic stem cell (ESC) differentiation is marked by the formation of three germ layers from which all tissues types arise. Conventionally, ESCs are differentiated by altering their chemical microenvironment. Recently however, it was established that a mechanical microenvironment can also contribute towards cellular phenotype commitment. In this study, we report how the cellular mechanical microenvironment of soft substrates affects the differentiation and phenotypic commitment of ESCs. Mouse ESCs were cultured in a fibrin hydrogel matrix in 2D and 3D cultures. The gelation characteristics of the substrates were modulated by systematically altering the fibrinogen concentration and the fibrinogen-thrombin crosslinking ratio. Analysis of the ESCs cultured on different substrate conditions clearly illustrated the strong influence that substrate physical characteristics assert on cellular behaviours. Specifically, it was found that ESCs had a higher proliferation rate in gels of lower stiffness. Early differentiation events were studied by analyzing the gene and protein expression levels of early germ layer markers. Our results revealed that lower substrate stiffness elicited stronger upregulation of endoderm related genes Sox17, Afp and Hnf4 compared to stiffer substrates. While both 2D and 3D cultures showed a similar response, the effects were much stronger in 3D culture. These results suggest that physical cues can be used to modulate ESC differentiation into clinically relevant tissues such as liver and pancreas.

  9. Vincristine-resistant erythroleukemia cell line has marked increased sensitivity to hexamethylenebisacetamide-induced differentiation.

    PubMed Central

    Melloni, E; Pontremoli, S; Damiani, G; Viotti, P; Weich, N; Rifkind, R A; Marks, P A

    1988-01-01

    Hexamethylenebisacetamide (HMBA)-induced murine erythroleukemia (MEL) differentiation is a multistep process. Commitment is the capacity to express terminal cell division and characteristics of the differentiated phenotype even after the cells are removed from culture with inducer. Culture of MEL cell line 745A.DS19 (DS19) with HMBA causes commitment to terminal differentiation after a latent period of about 10-12 hr. Previous studies have shown that during this latent period, HMBA causes a number of metabolic changes, including modulation in expression of certain protooncogenes. We now report the development of a MEL cell line (designated V3.17) derived from DS19 that is resistant to vincristine and is (i) markedly more sensitive to HMBA, (ii) induced to commitment without a detectable latent period, and (iii) resistant to the effects of phorbol ester and dexamethasone, which are potent inhibitors of HMBA-mediated DS19 differentiation. We suggest that this V3.17 MEL cell line may express a factor that circumvents HMBA-mediated early events, which prepare the cells for commitment to terminal differentiation. Images PMID:3163801

  10. Smurf1 plays a role in EGF inhibition of BMP2-induced osteogenic differentiation

    SciTech Connect

    Lee, Hye-Lim; Park, Hyun-Jung; Kwon, Arang; Baek, Kyunghwa; Woo, Kyung Mi; Ryoo, Hyun-Mo; Kim, Gwan-Shik; Baek, Jeong-Hwa

    2014-05-01

    It has been demonstrated that epidermal growth factor (EGF) plays a role in supporting the proliferation of bone marrow stromal cells in bone but inhibits their osteogenic differentiation. However, the mechanism underlying EGF inhibition of osteoblast differentiation remains unclear. Smurf1 is an E3 ubiquitin ligase that targets Smad1/5 and Runx2, which are critical transcription factors for bone morphogenetic protein 2 (BMP2)-induced osteoblast differentiation. In this study, we investigated the effect of EGF on the expression of Smurf1, and the role of Smurf1 in EGF inhibition of osteogenic differentiation using C2C12 cells, a murine myoblast cell line. EGF increased Smurf1 expression, which was blocked by inhibiting the activity of either JNK or ERK. Chromatin immunoprecipitation and Smurf1 promoter assays demonstrated that c-Jun and Runx2 play roles in the EGF induction of Smurf1 transcription. EGF suppressed BMP2-induced expression of osteogenic marker genes, which were rescued by Smurf1 knockdown. EGF downregulated the protein levels of Runx2 and Smad1 in a proteasome-dependent manner. EGF decreased the transcriptional activity of Runx2 and Smurf1, which was partially rescued by Smurf1 silencing. Taken together, these results suggest that EGF increases Smurf1 expression via the activation of JNK and ERK and the subsequent binding of c-Jun and Runx2 to the Smurf1 promoter and that Smurf1 mediates the inhibitory effect of EGF on BMP2-induced osteoblast differentiation. - Highlights: • EGF increases the expression level of Smurf1 in mesenchymal precursor cells. • EGF reduces the protein levels and transcriptional activity of Runx2 and Smad1. • EGF suppresses BMP2-induced osteogenic differentiation, which is rescued by Smurf1 knockdown.

  11. Protection from MPTP-induced neurotoxicity in differentiating mouse N2a neuroblastoma cells.

    PubMed

    De Girolamo, L A; Hargreaves, A J; Billett, E E

    2001-02-01

    We have shown previously that subcytotoxic concentrations of MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) inhibit axon outgrowth and are associated with increased neurofilament heavy chain (NF-H) phosphorylation in differentiating mouse N2a neuroblastoma cells while higher doses (> 100 microM) cause cell death. In this work we assessed the ability of potential neuroprotective agents to alleviate both MPTP-induced cell death (cytotoxicity) and MPTP-induced NF-H phosphorylation/reduction in axon outgrowth (neurotoxicity) in N2a cells induced to differentiate by dbcAMP. The neurotoxic effects of MPTP occurred in the absence of significant alterations in energy status or mitochondrial membrane potential. The hormone oestradiol (100 microM) reduced the cytotoxic effect of MPTP, but blocked di-butyryl cyclic AMP (dbcAMP)-induced differentiation, i.e. axon outgrowth. Both the cytotoxic and neurotoxic effects of MPTP were reduced by the monoamine oxidase (MAO) inhibitors deprenyl and, to a lesser extent, clorgyline. Alleviation of both neurotoxicity and cytotoxicity was also achieved by conditioned medium derived from rat C6 glioma cells. In contrast, whilst the p38 MAP kinase inhibitor, SB202190, protected cells against MPTP-induced neurotoxicity, it could not maintain cell viability at high MPTP exposures. In each case neuroprotection involved maintenance of the differentiating phenotype linked with attenuation of NF-H hyper-phosphorylation; the latter may represent a mechanism by which neuronal cells can moderate MPTP-induced neurotoxicity. The use of a simplified neuronal cell model, which expresses subtle biochemical changes following neurotoxic insult, could therefore provide a valuable tool for the identification of potential neuroprotective agents.

  12. Rejuvenation of Appalachian topography due to subsidence induced differential erosion

    NASA Astrophysics Data System (ADS)

    Liu, L.

    2014-12-01

    In ancient orogens, such as the Appalachian Mountains in the eastern United States, the difference between the high and low points—topographic relief—can continue to increase long after the tectonic forces that created the range have become inactive. Climatic forcing and mantle-induced dynamic uplift are proposed to drive formation of relief, but clear evidence is lacking in the Appalachian Mountains. Here I use a numerical simulation of dynamic topography in North America, combined with reconstructions of the sedimentation history from the Gulf of Mexico, to show that rejuvenation of topographic relief in the Appalachian Mountains since the Palaeogene period could have been caused by mantle-induced dynamic subsidence associated with sinking of the subducted Farallon slab. Specifically, I show that patterns of continental erosion and the eastward migration of sediment deposition centres in the Gulf of Mexico closely follow the locus of predicted dynamic subsidence. Furthermore, pulses of rapid sediment deposition in the Gulf of Mexico and western Atlantic correlate with enhanced erosion in the Appalachian Mountains during the Miocene epoch, caused by dynamic tilting of the continent. Calculations show that such subsidence-induced differential erosion caused flexural-isostatic adjustments of Appalachian topography that led to the development of both relief and elevation. I propose that dynamically induced continental tilting may provide a mechanism for topographic rejuvenation in ancient orogens.

  13. Ketamine-Induced Toxicity in Neurons Differentiated from Neural Stem Cells.

    PubMed

    Slikker, William; Liu, Fang; Rainosek, Shuo W; Patterson, Tucker A; Sadovova, Natalya; Hanig, Joseph P; Paule, Merle G; Wang, Cheng

    2015-10-01

    Ketamine is used as a general anesthetic, and recent data suggest that anesthetics can cause neuronal damage when exposure occurs during development. The precise mechanisms are not completely understood. To evaluate the degree of ketamine-induced neuronal toxicity, neural stem cells were isolated from gestational day 16 rat fetuses. On the eighth day in culture, proliferating neural stem cells were exposed for 24 h to ketamine at 1, 10, 100, and 500 μM. To determine the effect of ketamine on differentiated stem cells, separate cultures of neural stem cells were maintained in transition medium (DIV 6) for 1 day and kept in differentiation medium for another 3 days. Differentiated neural cells were exposed for 24 h to 10 μM ketamine. Markers of cellular proliferation and differentiation, mitochondrial health, cell death/damage, and oxidative damage were monitored to determine: (1) the effects of ketamine on neural stem cell proliferation and neural stem cell differentiation; (2) the nature and degree of ketamine-induced toxicity in proliferating neural stem cells and differentiated neural cells; and (3) to provide information regarding receptor expression and possible mechanisms underlying ketamine toxicity. After ketamine exposure at a clinically relevant concentration (10 μM), neural stem cell proliferation was not significantly affected and oxidative DNA damage was not induced. No significant effect on mitochondrial viability (3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay) in neural stem cell cultures (growth medium) was observed at ketamine concentrations up to 500 μM. However, quantitative analysis shows that the number of differentiated neurons was substantially reduced in 10 μM ketamine-exposed cultures in differentiation medium, compared with the controls. No significant changes in the number of GFAP-positive astrocytes and O4-positive oligodendrocytes (in differentiation medium) were detected from ketamine-exposed cultures

  14. C(5) modified uracil derivatives showing antiproliferative and erythroid differentiation inducing activities on human chronic myelogenous leukemia K562 cells

    PubMed Central

    Brognara, Eleonora; Lampronti, Ilaria; Breveglieri, Giulia; Accetta, Alessandro; Corradini, Roberto; Manicardi, Alex; Borgatti, Monica; Canella, Alessandro; Multineddu, Chiara; Marchelli, Rosangela; Gambari, Roberto

    2011-01-01

    The K562 cell line has been proposed as a useful experimental system to identify anti-tumor compounds acting by inducing terminal erythroid differentiation. K562 cells exhibit a low proportion of hemoglobin-synthesizing cells under standard cell growth conditions, but are able to undergo terminal erythroid differentiation when treated with a variety of anti-tumor compounds. In this paper we report a screening study on a set of different modified C(5) uracil derivatives for the evaluation of their antiproliferative effect in connection with erythroid differentiation pathways, and for defining a new class of drug candidates for the treatment of chronic myelogenous leukemia. Activity of the derivatives tested can be classified in two effect: an antiproliferative effect linked to a high level of erythroid differentiation activity and an antiproliferative effect without activation of gamma globin genes The highest antiproliferative effect and erythroid induction was shown by compound 9, a thymine derivative bearing a n-octyl chain on nitrogen N(1), whereas thymine did not show any effect, suggesting the importance of the linear alkyl chain in position N(1). To our knowledge this compound should be considered among the most efficient inducers of erythroid differentiation of K562 cells. This work is the starting point for the quest of more effective and specific drugs for the induction of terminal erythroid differentiation, for leading new insights in the treatment of neoplastic diseases with molecules acting by inducing differentiation rather than by simply exerting cytotoxic effects. PMID:21958870

  15. Detection of Explosives Using Differential Laser-Induced Perturbation Spectroscopy with a Raman-based Probe.

    PubMed

    Oztekin, Erman K; Burton, Dallas J; Hahn, David W

    2016-04-01

    Explosives detection is carried out with a novel spectral analysis technique referred to as differential laser-induced perturbation spectroscopy (DLIPS) on thin films of TNT, RDX, HMX, and PETN. The utility of Raman spectroscopy for detection of explosives is enhanced by inducing deep ultraviolet laser perturbation on molecular structures in combination with a differential Raman sensing scheme. Principal components analysis (PCA) is used to quantify the DLIPS method as benchmarked against a traditional Raman scattering probe, and the related photo-induced effects on the molecular structure of the targeted explosives are discussed in detail. Finally, unique detection is observed with TNT samples deposited on commonly available background substrates of nylon and polyester. Overall, the data support DLIPS as a noninvasive method that is promising for screening explosives in real-world environments and backgrounds.

  16. The effect of dehydroleucodine in adipocyte differentiation.

    PubMed Central

    Galvis, Adriana; Marcano, Adriana; Stefancin, Chad; Villaverde, Nicole; Priestap, Horacio A.; Tonn, Carlos E.; Lopez, Luis A.; Barbieri, Manuel A.

    2012-01-01

    Dehydroleucodine (DhL) is a sesquiterpene lactone of the guaianolide group with gastric citoprotective activity. Recent studies have also demonstrated that DhL inhibits the proliferation of vascular smooth muscle cells. In this study we examined the effect of DhL in the differentiation 3T3-L1 preadipocytes. The addition of DhL significantly inhibited the differentiation 3T3-L1 preadipocytes along with significant decrease in the accumulation of lipid content by a dramatic down regulation of the expression of adipogenic-specific transcriptional factors PPARγ and C-EBPα. However, phosphorylation of AMPKα, Erk1/2 and Akt1 was not inhibited by DhL treatment. Interestingly, we also found that 11,13-dihydro-dehydroleucodine, a derivative of DhL with inactivated α-methylene-γ-lactone function, also inhibited the differentiation 3T3-L1 preadipocytes. Taken together, these data suggest DhL has an important inhibitory effect in cellular pathways regulating adipocyte differentiation by modulating the PPARγ expression, which is known to play a pivotal role during adipogenesis. PMID:21963454

  17. Curcumin Inhibits Transforming Growth Factor β Induced Differentiation of Mouse Lung Fibroblasts to Myofibroblasts

    PubMed Central

    Liu, Daishun; Gong, Ling; Zhu, Honglan; Pu, Shenglan; Wu, Yang; Zhang, Wei; Huang, Guichuan

    2016-01-01

    Transforming growth factor β (TGF-β) induced differentiation of lung fibroblasts to myofibroblasts is a key event in the pathogenesis of pulmonary fibrosis. This study aimed to evaluate the effect of curcumin on TGF-β induced differentiation of lung fibroblasts to myofibroblasts and explore the underlying mechanism. Mouse lung fibroblasts were cultured and treated with TGF-β2 and curcumin or rosiglitazone. Cell vitality was examined by MTT assay. The secretion of collagen-1 was assessed by ELISA. α smooth muscle actin (α-SMA) was visualized by immunofluorescence technique. The expression of peroxisome proliferator activated receptor γ (PPAR-γ) and platelet derived growth factor R β (PDGFR-β) was detected by PCR and Western blot analysis. We found that curcumin and rosiglitazone inhibited the proliferation and TGF-β induced differentiation of mouse lung fibroblasts. In addition, curcumin and rosiglitazone inhibited collagen-1 secretion and α-SMA expression in mouse lung fibroblasts. Furthermore, curcumin and rosiglitazone upregulated PPAR-γ and downregulated PDGFR-β expression in mouse lung fibroblasts. In conclusion, our study reveals novel mechanism by which curcumin inhibits TGF-β2 driven differentiation of lung fibroblasts to myofibroblasts. Curcumin could potentially be used for effective treatment of pulmonary fibrosis. PMID:27877129

  18. A new method to induce molecular low bias negative differential resistance with multi-peaks

    NASA Astrophysics Data System (ADS)

    Min, Y.; Zhong, C. G.; Dong, Z. C.; Zhao, Z. Y.; Zhou, P. X.; Yao, K. L.

    2016-02-01

    According to a first-principles study of the transport properties of two thiolated anthracene-9,10-diono molecules sandwiching ethyl, a new method to induce molecular low bias negative differential resistance with multi-peaks for strong n- or p-type molecules is proposed. The anthracene-9,10-diono molecule shows strong n-type characteristics when in contact with Au and Ag electrodes via a thiolate. The multiple negative differential resistance effect originated from the molecule-electrode couple is different between Ag and Au electrodes. Our investigations may promise potential for applications in molecular devices with low power dissipation and multifunction in the future.

  19. Glyphosate Inhibits PPAR Gamma Induction and Differentiation of Preadipocytes and is able to Induce Oxidative Stress.

    PubMed

    Martini, Claudia N; Gabrielli, Matías; Brandani, Javier N; Vila, María Del C

    2016-08-01

    Glyphosate-based herbicides (GF) are extensively used for weed control. Thus, it is important to investigate their putative toxic effects. We have reported that GF at subagriculture concentrations inhibits proliferation and differentiation to adipocytes of 3T3-L1 fibroblasts. In this investigation, we evaluated the effect of GF on genes upregulated during adipogenesis. GF was able to inhibit the induction of PPAR gamma, the master gene in adipogenesis but not C/EBP beta, which precedes PPAR gamma activation. GF also inhibited differentiation and proliferation of another model of preadipocyte: mouse embryonic fibroblasts. In exponentially growing 3T3-L1 cells, GF increased lipid peroxidation and the activity of the antioxidant enzyme, superoxide dismutase. We also found that proliferation was inhibited with lower concentrations of GF when time of exposure was extended. Thus, GF was able to inhibit proliferation and differentiation of preadipocytes and to induce oxidative stress, which is indicative of its ability to alter cellular physiology.

  20. Differentiation-inducing factor-1 induces cyclin D1 degradation through the phosphorylation of Thr{sup 286} in squamous cell carcinoma

    SciTech Connect

    Mori, Jun; Takahashi-Yanaga, Fumi . E-mail: yanaga@clipharm.med.kyushu-u.ac.jp; Miwa, Yoshikazu; Watanabe, Yutaka; Hirata, Masato; Morimoto, Sachio; Shirasuna, Kanemitsu; Sasaguri, Toshiyuki

    2005-11-01

    Differentiation-inducing factors (DIFs) are morphogens which induce cell differentiation in Dictyostelium. We reported that DIF-1 and DIF-3 inhibit proliferation and induce differentiation in mammalian cells. In this study, we investigated the effect of DIF-1 on oral squamous cell carcinoma cell lines NA and SAS, well differentiated and poorly differentiated cell lines, respectively. Although DIF-1 did not induce the expression of cell differentiation makers in these cell lines, it inhibited the proliferation of NA and SAS in a dose-dependent manner by restricting the cell cycle in the G{sub 0}/G{sub 1} phase. DIF-1 induced cyclin D1 degradation, but this effect was prevented by treatment with lithium chloride and SB216763, the inhibitors of glycogen synthase kinase-3{beta} (GSK-3{beta}). Depletion of endogenous GSK-3{beta} by RNA interference also attenuated the effect of DIF-1 on cyclin D1 degradation. Therefore, we investigated the effect of DIF-1 on GSK-3{beta} and found that DIF-1 dephosphorylated GSK-3{beta} on Ser{sup 9} and induced the nuclear translocation of GSK-3{beta}, suggesting that DIF-1 activated GSK-3{beta}. Then, we examined the effect of DIF-1 on cyclin D1 mutants (Thr286Ala, Thr288Ala, and Thr286/288Ala). We revealed that Thr286Ala and Thr286/288Ala mutants were highly resistant to DIF-1-induced degradation compared with wild-type cyclin D1, indicating that the phosphorylation of Thr{sup 286} was critical for cyclin D1 degradation induced by DIF-1. These results suggest that DIF-1 induces degradation of cyclin D1 through the GSK-3{beta}-mediated phosphorylation of Thr{sup 286}.

  1. Resveratrol Induces Vascular Smooth Muscle Cell Differentiation through Stimulation of SirT1 and AMPK

    PubMed Central

    Thompson, Anne Marie; Martin, Kathleen A.; Rzucidlo, Eva M.

    2014-01-01

    Phenotypic plasticity in vascular smooth muscle cells (VSMC) is necessary for vessel maintenance, repair and adaptation to vascular changes associated with aging. De-differentiated VSMC contribute to pathologies including atherosclerosis and intimal hyperplasia. As resveratrol has been reported to have cardio- protective effects, we investigated its role in VSMC phenotypic modulation. We demonstrated the novel finding that resveratrol promoted VSMC differentiation as measured by contractile protein expression, contractile morphology and contraction in collagen gels. Resveratrol induced VSMC differentiation through stimulation of SirT1 and AMPK. We made the novel finding that low or high dose resveratrol had an initially different mechanism on induction of differentiation. We found that low dose resveratrol stimulated differentiation through SirT1-mediated activation of AKT, whereas high dose resveratrol stimulated differentiation through AMPK-mediated inhibition of the mTORC1 pathway, allowing activation of AKT. The health effects of resveratrol in cardiovascular diseases, cancer and longevity are an area of active research. We have demonstrated a supplemental avenue where-by resveratrol may promote health by maintaining and enhancing plasticity of the vasculature. PMID:24416418

  2. Alternative splicing of CARMA2/CARD14 transcripts generates protein variants with differential effect on NF-κB activation and endoplasmic reticulum stress-induced cell death.

    PubMed

    Scudiero, Ivan; Zotti, Tiziana; Ferravante, Angela; Vessichelli, Mariangela; Vito, Pasquale; Stilo, Romania

    2011-12-01

    The caspase recruitment domain (CARD)-containing proteins CARMA1-3 share high degree of sequence, structure and functional homology. Whereas CARMA1 and CARMA3 have been identified as crucial components of signal transduction pathways that lead to activation of NF-κB transcription factor, little is known about the function of CARMA2. Here we report the identification of two splice variants of CARMA2. One transcript, named CARMA2short (CARMA2sh), is predicted to encode for a CARMA2 polypeptide containing the CARD, coiled coil, and a PDZ domains, but lacking the SH3 and the GuK domains. The second variant, CARMA2cardless (CARMA2cl), encodes for a polypeptide lacking the CARD domain and containing only a portion of the coiled coil domain and a linker region. Expression analysis confirmed the presence of the CARMA2 alternatively spliced transcripts in both human cell lines and tissues. Fluorescence microscopy data show that both splice variants localize in the cytosol. Biochemical experiments indicate that CARMA2sh interacts with TRAF2 and activates NF-κB in a TRAF2-dependent manner. Finally, CARMA2sh variant protects cells from apoptosis induced by different stimuli. Taken together, these results demonstrate that multiple transcripts encoding several CARMA2 isoforms exist in vivo and regulate NF-κB activation and apoptosis.

  3. Alternative Splicing of CARMA2/CARD14 Transcripts Generates Protein Variants With Differential Effect on NF-κB Activation and Endoplasmic Reticulum Stress-Induced Cell Death

    PubMed Central

    Scudiero, Ivan; Zotti, Tiziana; Ferravante, Angela; Vessichelli, Mariangela; Vito, Pasquale; Stilo, Romania

    2011-01-01

    The caspase recruitment domain (CARD)-containing proteins CARMA1-3 share high degree of sequence, structure and functional homology. Whereas CARMA1 and CARMA3 have been identified as crucial components of signal transduction pathways that lead to activation of NF-κB transcription factor, little is known about the function of CARMA2. Here we report the identification of two splice variants of CARMA2. One transcript, named CARMA2short (CARMA2sh), is predicted to encode for a CARMA2 polypeptide containing the CARD, coiled coil, and a PDZ domains, but lacking the SH3 and the GuK domains. The second variant, CARMA2cardless (CARMA2cl), encodes for a polypeptide lacking the CARD domain and containing only a portion of the coiled coil domain and a linker region. Expression analysis confirmed the presence of the CARMA2 alternatively spliced transcripts in both human cell lines and tissues. Fluorescence microscopy data show that both splice variants localize in the cytosol. Biochemical experiments indicate that CARMA2sh interacts with TRAF2 and activates NF-κB in a TRAF2-dependent manner. Finally, CARMA2sh variant protects cells from apoptosis induced by different stimuli. Taken together, these results demonstrate that multiple transcripts encoding several CARMA2 isoforms exist in vivo and regulate NF-κB activation and apoptosis. J. Cell. Physiol. 226: 3121–3131, 2011. © 2011 Wiley Periodicals, Inc. PMID:21302310

  4. Bisphenol A and Bisphenol S Induce Distinct Transcriptional Profiles in Differentiating Human Primary Preadipocytes

    PubMed Central

    Boucher, Jonathan G.; Gagné, Rémi; Rowan-Carroll, Andrea; Boudreau, Adèle; Yauk, Carole L.; Atlas, Ella

    2016-01-01

    Bisphenol S (BPS) is increasingly used as a replacement plasticizer for bisphenol A (BPA) but its effects on human health have not been thoroughly examined. Recent evidence indicates that both BPA and BPS induce adipogenesis, although the mechanisms leading to this effect are unclear. In an effort to identify common and distinct mechanisms of action in inducing adipogenesis, transcriptional profiles of differentiating human preadipocytes exposed to BPA or BPS were compared. Human subcutaneous primary preadipocytes were differentiated in the presence of either 25 μM BPA or BPS for 2 and 4 days. Poly-A RNA-sequencing was used to identify differentially expressed genes (DEGs). Functional analysis of DEGs was undertaken in Ingenuity Pathway Analysis. BPA-treatment resulted in 472 and 176 DEGs on days 2 and 4, respectively, affecting pathways such as liver X receptor (LXR)/retinoid X receptor (RXR) activation, hepatic fibrosis and cholestasis. BPS-treatment resulted in 195 and 51 DEGs on days 2 and 4, respectively, revealing enrichment of genes associated with adipogenesis and lipid metabolism including the adipogenesis pathway and cholesterol biosynthesis. Interestingly, the transcription repressor N-CoR was identified as a negative upstream regulator in both BPA- and BPS-treated cells. This study presents the first comparison of BPA- and BPS-induced transcriptional profiles in human differentiating preadipocytes. While we previously showed that BPA and BPS both induce adipogenesis, the results from this study show that BPS affects adipose specific transcriptional changes earlier than BPA, and alters the expression of genes specifically related to adipogenesis and lipid metabolism. The findings provide insight into potential BPS and BPA-mediated mechanisms of action in inducing adipogenesis in human primary preadipocytes. PMID:27685785

  5. PDGF-induced PI3K-mediated signaling enhances the TGF-β-induced osteogenic differentiation of human mesenchymal stem cells in a TGF-β-activated MEK-dependent manner.

    PubMed

    Yokota, Jun; Chosa, Naoyuki; Sawada, Shunsuke; Okubo, Naoto; Takahashi, Noriko; Hasegawa, Tomokazu; Kondo, Hisatomo; Ishisaki, Akira

    2014-03-01

    Transforming growth factor-β (TGF-β) is a critical regulator of osteogenic differentiation and the platelet-derived growth factor (PDGF) is a chemoattractant or mitogen of osteogenic mesenchymal cells. However, the combined effects of these regulators on the osteogenic differentiation of mesenchymal cells remains unknown. In this study, we investigated the effects of TGF-β and/or PDGF on the osteogenic differentiation of human mesenchymal stem cells (hMSCs). The TGF-β-induced osteogenic differentiation of UE7T-13 cells, a bone marrow-derived hMSC line, was markedly enhanced by PDGF, although PDGF alone did not induce differentiation. TGF-β induced extracellular signal-regulated kinase (ERK) phosphorylation and PDGF induced Akt phosphorylation. In addition, the mitogen-activated protein kinase (MAPK)/ERK kinase (MEK) inhibitor, U0126, suppressed the osteogenic differentiation induced by TGF-β alone. Moreover, U0126 completely suppressed the osteogenic differentiation synergistically induced by TGF-β and PDGF, whereas the phosphoinositide-3-kinase (PI3K) inhibitor, LY294002, only partially suppressed this effect. These results suggest that the enhancement of TGF-β-induced osteogenic differentiation by PDGF-induced PI3K/Akt-mediated signaling depends on TGF-β-induced MEK activity. Thus, PDGF positively modulates the TGF-β-induced osteogenic differentiation of hMSCs through synergistic crosstalk between MEK- and PI3K/Akt-mediated signaling.

  6. DIFFERENTIAL EFFECTS OF SELECTIVE ADENOSINE ANTAGONISTS ON THE EFFORT-RELATED IMPAIRMENTS INDUCED BY DOPAMINE D1 AND D2 ANTAGONISM

    PubMed Central

    Nunes, Eric J.; Randall, Patrick A.; Santerre, Jessica L.; Given, Ashby B.; Sager, Thomas N.; Correa, Merce; Salamone, John D.

    2010-01-01

    Mesolimbic dopamine (DA) is a critical component of the brain circuitry regulating behavioral activation and effort-related processes. Rats with impaired DA transmission reallocate their instrumental behavior away from food-reinforced tasks with high response requirements, and instead select less effortful food-seeking behaviors. Previous work showed that adenosine A2A antagonists can reverse the effects of DA D2 antagonists on effort-related choice. However, less is known about the effects of adenosine A1 antagonists. Despite anatomical data showing that A1 and D1 receptors are co-localized on the same striatal neurons, it is uncertain if A1 antagonists can reverse the effects DA D1 antagonists. The present work systematically compared the ability of adenosine A1 and A2A receptor antagonists to reverse the effects of DA D1 and D2 antagonists on a concurrent lever pressing/feeding choice task. With this procedure, rats can choose between responding on a fixed ratio 5 lever-pressing schedule for a highly preferred food (i.e., high carbohydrate pellets) vs. approaching and consuming a less preferred rodent chow. The D1 antagonist ecopipam (0.2 mg/kg IP) and the D2 antagonist eticlopride (0.08 mg/kg IP) altered choice behavior, reducing lever pressing and increasing lab chow intake. Co-administration of the adenosine A1 receptor antagonists DPCPX (0.375, 0.75, and 1.5 mg/kg IP), and CPT (3.0, 6.0, 12.0 mg/kg IP) failed to reverse the effects of either the D1 or D2 antagonist. In contrast, the adenosine A2A antagonist KW-6002 (0.125, 0.25 and 0.5 mg/kg IP) was able to produce a robust reversal of the effects of eticlopride, as well as a mild partial reversal of the effects of ecopipam. Adenosine A2A and DA D2 receptors interact to regulate effort-related choice behavior, which may have implications for the treatment of psychiatric symptoms such as psychomotor slowing, fatigue or anergia that can be observed in depression and other disorders. PMID:20600675

  7. Deletion of Alox5 gene decreases osteogenic differentiation but increases adipogenic differentiation of mouse induced pluripotent stem cells.

    PubMed

    Wu, Yanru; Sun, Hualing; Song, Fangfang; Huang, Cui; Wang, Jiawei

    2014-10-01

    Induced pluripotent stem cells (iPSCs) have great potential in bone tissue engineering to repair large bone defects. Before their clinical application, investigations are needed to discover the genes and osteoconductive scaffolds that influence their differentiation toward an osteogenic lineage. Alox5 plays controversial and complex roles in the regulation of bone and fat metabolism. To detect the effect of Alox5 on osteogenic and adipogenic differentiation of iPSCs, both Alox5 knockout mouse iPSCs (Alox5-KO-iPSCs) and wild-type mouse iPSCs (Wild-iPSCs) were developed. The mRNA levels of many osteogenic markers in Alox5-KO-iPSCs were significantly reduced, while many adipogenic markers were enhanced. Furthermore, when implanted in rat cranial critical-sized defects with collagen/chitosan/hydroxyapatite scaffolds (CCHS), Alox5-KO-iPSCs produced significantly less new bone than Wild-iPSCs and both cell-scaffold groups had no tumor formation. There was a significant difference in the expression of Cox2 during the osteogenic and adipogenic differentiation between the two kinds of iPSCs in vitro. In conclusion, firstly, Alox5 knockout reduced the osteogenic but increased the adipogenic differentiation potential of mouse iPSCs. These disorders might be related to the change of Cox2 expression. Secondly, combined with iPSCs, CCHS can serve as a potential substrate to repair critical-sized bony defects. However, more studies are required to confirm the mechanisms through which Alox5 affects the osteogenic and adipogenic abilities of iPSCs in vivo and the effect of Cox2 inhibition in this system.

  8. Topography of methylphenidate (ritalin)-induced gene regulation in the striatum: differential effects on c-fos, substance P and opioid peptides.

    PubMed

    Yano, Motoyo; Steiner, Heinz

    2005-05-01

    Dopamine action alters gene regulation in striatal neurons. Methylphenidate increases extracellular levels of dopamine. We investigated the effects of acute methylphenidate treatment on gene expression in the striatum of adult rats. Molecular changes were mapped in 23 striatal sectors mostly defined by their predominant cortical inputs in order to determine the functional domains affected. Acute administration of 5 and 10 mg/kg (i.p.) of methylphenidate produced robust increases in the expression of the transcription factor c-fos and the neuropeptide substance P. Borderline effects were found with 2 mg/kg, but not with 0.5 mg/kg. For 5 mg/kg, c-fos mRNA levels peaked at 40 min and returned to baseline by 3 h after injection, while substance P mRNA levels peaked at 40-60 min and were back near control levels by 24 h. These molecular changes occurred in most sectors of the caudate-putamen, but were maximal in dorsal sectors that receive sensorimotor and medial agranular cortical inputs, on middle to caudal levels. In rostral and ventral striatal sectors, changes in c-fos and substance P expression were weaker or absent. No effects were seen in the nucleus accumbens, with the exception of c-fos induction in the lateral part of the shell. In contrast to c-fos and substance P, acute methylphenidate treatment had minimal effects on the opioid peptides dynorphin and enkephalin. These results demonstrate that acute methylphenidate alters the expression of c-fos and substance P preferentially in the sensorimotor striatum. These molecular changes are similar, but not identical, to those produced by other psychostimulants.

  9. High dose and low dose Lactobacilli acidophilus exerted differential immune modulating effects on T cell immune responses induced by an oral human rotavirus vaccine in gnotobiotic pigs

    PubMed Central

    Wen, Ke; Li, Guohua; Bui, Tammy; Liu, Fangning; Li, Yanru; Kocher, Jacob; Lin, Lin; Yang, Xingdong; Yuan, Lijuan

    2011-01-01

    Background Strain-specific effects of probiotics in pro- or anti-inflammatory immune responses have been well recognized. Several proinflammatory Lactobacillus strains have been shown to act as adjuvants to enhance the immunogenicity of vaccines. However, dose effects of probiotics in modulating immune responses are not clearly understood. This study examined the dose effects of Lactobacillus acidophilus (LA) NCFM strain on T cell immune responses to rotavirus vaccination in a gnotobiotic (Gn) pig model. Methods Frequencies of IFN-γ producing CD4+ and CD8+ T cell and IL-10 and TGF-β producing CD4+CD25+ and CD4+CD25- regulatory T (Treg) cell responses were determined in the intestinal and systemic lymphoid tissues of Gn pigs vaccinated with an oral human rotavirus vaccine in conjunction with low dose (5 feedings; up to 106 colony forming units [CFU]/dose) or high dose (14 feedings; up to 109 CFU/dose) or without LA feeding. Results Low dose LA significantly promoted IFN-γ producing T cell responses and down-regulated Treg cell responses and their TGF-β and IL-10 productions in all the tissues compared to the high dose LA and control groups. To the contrary, high dose LA increased the frequencies of Treg cells in most of the tissues compared to the control groups. The dose effects of LA on IFN-γ producing T cell and CD4+CD25- Treg cell immune responses were similar in the intestinal and systemic lymphoid tissues and were independent from the vaccination. Conclusion Thus the same probiotic strain in different doses can either promote or suppress IFN-γ producing T cell or Treg cell immune responses. These findings have significant implications in the use of probiotic lactobacilli as immunostimulatory versus immunoregulatory agents. Probiotics can be ineffective or even detrimental if not used at the optimal dosage for the appropriate purposes. PMID:22178726

  10. Effects of Hypogravity on Osteoblast Differentiation

    NASA Technical Reports Server (NTRS)

    Globus, Ruth; Doty, Steven

    1997-01-01

    Weightbearing is essential for normal skeletal function. Without weightbearing, the rate of bone formation by osteoblasts decreases in the growing rat. Defective formation may account for the decrease in the maturation, strength and mass of bone that is caused by spaceflight. These skeletal defects may be mediated by a combination of physiologic changes triggered by spaceflight, including skeletal unloading, fluid shifts, and stress-induced endocrine factors. The fundamental question of whether the defects in osteoblast function due to weightlessness are mediated by localized skeletal unloading or by systemic physiologic adaptations such as fluid shifts has not been answered. Furthermore, bone-forming activity of osteoblasts during unloading may be affected by paracrine signals from vascular, monocytic, and neural cells that also reside in skeletal tissue. Therefore we proposed to examine whether exposure of cultured rat osteoblasts to spaceflight inhibits cellular differentiation and impairs mineralization when isolated from the influence of both systemic factors and other skeletal cells.

  11. Differential effects of detergents on keratinocyte gene expression.

    PubMed

    van Ruissen, F; Le, M; Carroll, J M; van der Valk, P G; Schalkwijk, J

    1998-04-01

    We have studied the effect of various detergents on keratinocyte gene expression in vitro, using an anionic detergent (sodium dodecyl sulfate), a cationic detergent cetyltrimethylammoniumbromide (CTAB), and two nonionic detergents, Nonidet P-40 and Tween-20. We measured the effect of these detergents on direct cellular toxicity (lactate dehydrogenase release), on the expression of markers for normal differentiation (cytokeratin 1 and involucrin expression), and on disturbed keratinocyte differentiation (SKALP) by northern blot analysis. As reported in other studies, large differences were noted in direct cellular toxicity. In a culture model that mimics normal epidermal differentiation we found that low concentrations of sodium dodecyl sulfate could induce the expression of SKALP, a proteinase inhibitor that is not normally expressed in human epidermis but is found in hyperproliferative skin. Sodium dodecyl sulfate caused upregulation of involucrin and downregulation of cytokeratin 1 expression, which is associated with the hyperproliferative/inflammatory epidermal phenotype found in psoriasis, wound healing, and skin irritation. These changes were not induced after treatment of cultures with CTAB, Triton X-100, and Nonidet-P40. This effect appeared to be specific for the class of anionic detergents because sodium dodecyl benzene sulfonate and sodium laurate also induced SKALP expression. These in vitro findings showed only a partial correlation with the potential of different detergents to induce clinical, biophysical, and cell biologic changes in vivo in human skin. Both sodium dodecyl sulfate and CTAB were found to cause induction and upregulation of SKALP and involucrin at low doses following a 24 h patch test, whereas high concentrations of Triton X-100 did not. Sodium dodecyl sulfate induced higher rates of transepidermal water loss, whereas CTAB treated skin showed more signs of cellular toxicity. We conclude that the action of anionic detergents on

  12. Therapeutic effects of proteoliposomes on X-linked chronic granulomatous disease: proof of concept using macrophages differentiated from patient-specific induced pluripotent stem cells

    PubMed Central

    Brault, Julie; Vaganay, Guillaume; Le Roy, Aline; Lenormand, Jean-Luc; Cortes, Sandra; Stasia, Marie José

    2017-01-01

    Chronic granulomatous disease (CGD) is a rare inherited immunodeficiency due to dysfunction of the phagocytic nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex leading to severe and recurrent infections in early childhood. The main genetic form is the X-linked CGD leading to the absence of cytochrome b558 composed of NOX2 and p22phox, the membrane partners of the NADPH oxidase complex. The first cause of death of CGD patients is pulmonary infections. Recombinant proteoliposome-based therapy is an emerging and innovative approach for membrane protein delivery, which could be an alternative local, targeted treatment to fight lung infections in CGD patients. We developed an enzyme therapy using recombinant NOX2/p22phox liposomes to supply the NADPH oxidase activity in X0-linked CGD (X0-CGD) macrophages. Using an optimized prokaryotic cell-free protein synthesis system, a recombinant cytochrome b558 containing functional hemes was produced and directly inserted into the lipid bilayer of specific liposomes. The size of the NOX2/p22phox liposomes was estimated to be around 700 nm. These proteoliposomes were able to generate reactive oxygen species (ROS) in an activated reconstituted cell-free NADPH oxidase activation assay in the presence of recombinant p47phox, p67phox and Rac, the cytosolic components of the NADPH oxidase complex. Furthermore, using flow cytometry and fluorescence microscopy, we demonstrated that cytochrome b558 was successfully delivered to the plasma membrane of X0-CGD-induced pluripotent stem cell (iPSC)-derived macrophages. In addition, NADPH oxidase activity was restored in X0-CGD iPSC-derived macrophages treated with NOX2/p22phox liposomes for 8 h without any toxicity. In conclusion, we confirmed that proteoliposomes provide a new promising technology for the delivery of functional proteins to the membrane of targeted cells. This efficient liposomal enzyme replacement therapy will be useful for future treatment of pulmonary

  13. Folate antagonist, methotrexate induces neuronal differentiation of human embryonic stem cells transplanted into nude mouse retina.

    PubMed

    Hara, Akira; Taguchi, Ayako; Aoki, Hitomi; Hatano, Yuichiro; Niwa, Masayuki; Yamada, Yasuhiro; Kunisada, Takahiro

    2010-06-25

    Transplanted embryonic stem (ES) cells can be integrated into the retinas of adult mice as well-differentiated neuroretinal cells. However, the transplanted ES cells also have a tumorigenic activity as they have the ability for multipotent differentiation to various types of tissues. In the present study, human ES (hES) cells were transplanted into adult nude mouse retinas by intravitreal injections 20 h after intravitreal N-methyl-D-aspartate (NMDA) administration. After the transplantation of hES cells, the folate antagonist, methotrexate (MTX) was administrated in order to control the differentiation of the transplanted hES cells. Neuronal differentiation and teratogenic potential of hES cells were examined immunohistochemically 5 weeks after transplantation. The proliferative activity of transplanted cells was determined by both the mitotic index and the Ki-67 proliferative index. Disappearance of Oct-4-positive hES cells showing undifferentiated morphology was observed after intraperitoneal MTX treatment daily, for 15 days. Decreased mitotic and Ki-67 proliferative indices, and increased neuronal differentiation were detected in the surviving hES cells after the MTX treatment. These results suggest two important effects of intraperitoneal MTX treatment for hES cells transplanted into nude mouse retina: (1) MTX treatment following transplantation induces neuronal differentiation, and (2) MTX decreases proliferative activity and tumorigenic potential.

  14. Differential effects of cobalt and mercury on lipid metabolism in the white adipose tissue of high-fat diet-induced obesity mice

    SciTech Connect

    Kawakami, Takashige Hanao, Norihide; Nishiyama, Kaori; Kadota, Yoshito; Inoue, Masahisa; Sato, Masao; Suzuki, Shinya

    2012-01-01

    Metals and metalloid species are involved in homeostasis in energy systems such as glucose metabolism. Enlarged adipocytes are one of the most important causes of obesity-associated diseases. In this study, we studied the possibility that various metals, namely, CoCl{sub 2}, HgCl{sub 2}, NaAsO{sub 2} and MnCl{sub 2} pose risk to or have beneficial effects on white adipose tissue (WAT). Exposure to the four metals resulted in decreases in WAT weight and the size of enlarged adipocytes in mice fed a high-fat diet (HFD) without changes in liver weight, suggesting that the size and function of adipocytes are sensitive to metals. Repeated administration of CoCl{sub 2} significantly increased serum leptin, adiponectin and high-density lipoprotein (HDL) cholesterol levels and normalized glucose level and adipose cell size in mice fed HFD. In contrast, HgCl{sub 2} treatment significantly decreased serum leptin level with the down-regulation of leptin mRNA expression in WAT and a reduction in adipocyte size. Next, we tried to investigate possible factors that affect adipocyte size. Repeated exposure to HgCl{sub 2} significantly decreased the expression levels of factors upon the regulation of energy such as the PPARα and PPARγ mRNA expression levels in adipocytes, whereas CoCl{sub 2} had little effect on those genes expressions compared with that in the case of the mice fed HFD with a vehicle. In addition, repeated administration of CoCl{sub 2} enhanced AMPK activation in a dose-dependent manner in the liver, skeletal muscle and WAT; HgCl{sub 2} treatment also enhanced AMPK activation in the liver. Thus, both Co and Hg reduced WAT weight and the size of enlarged adipocytes, possibly mediated by AMKP activation in the mice fed HFD. However, inorganic cobalt may have a preventive role in obesity-related diseases through increased leptin, adiponectin and HDL-cholesterol levels, whereas inorganic mercury may accelerate the development of such diseases. These results may lead

  15. Retinoic acid induces Sertoli cell paracrine signals for spermatogonia differentiation but cell autonomously drives spermatocyte meiosis.

    PubMed

    Raverdeau, Mathilde; Gely-Pernot, Aurore; Féret, Betty; Dennefeld, Christine; Benoit, Gérard; Davidson, Irwin; Chambon, Pierre; Mark, Manuel; Ghyselinck, Norbert B

    2012-10-09

    Direct evidence for a role of endogenous retinoic acid (RA), the active metabolite of vitamin A in the initial differentiation and meiotic entry of spermatogonia, and thus in the initiation of spermatogenesis is still lacking. RA is synthesized by dedicated enzymes, the retinaldehyde dehydrogenases (RALDH), and binds to and activates nuclear RA receptors (RARA, RARB, and RARG) either within the RA-synthesizing cells or in the neighboring cells. In the present study, we have used a combination of somatic genetic ablations and pharmacological approaches in vivo to show that during the first, prepubertal, spermatogenic cycle (i) RALDH-dependent synthesis of RA by Sertoli cells (SC), the supporting cells of the germ cell (GC) lineage, is indispensable to initiate differentiation of A aligned into A1 spermatogonia; (ii) RARA in SC mediates the effects of RA, possibly through activating Mafb expression, a gene whose Drosophila homolog is mandatory to GC differentiation; (iii) RA synthesized by premeiotic spermatocytes cell autonomously induces meiotic initiation through controlling the RAR-dependent expression of Stra8. Furthermore, we show that RA of SC origin is no longer necessary for the subsequent spermatogenic cycles but essential to spermiation. Altogether, our data establish that the effects of RA in vivo on spermatogonia differentiation are indirect, via SC, but direct on meiotic initiation in spermatocytes, supporting thereby the notion that, contrary to the situation in the female, RA is necessary to induce meiosis in the male.

  16. Scoparone attenuates RANKL-induced osteoclastic differentiation through controlling reactive oxygen species production and scavenging

    SciTech Connect

    Lee, Sang-Hyun; Jang, Hae-Dong

    2015-02-15

    Scoparone, one of the bioactive components of Artemisia capillaris Thunb, has various biological properties including immunosuppressive, hepatoprotective, anti-allergic, anti-inflammatory, and antioxidant effects. This study aims at evaluating the anti-osteoporotic effect of scoparone and its underlying mechanism in vitro. Scoparone demonstrated potent cellular antioxidant capacity. It was also found that scoparone inhibited the receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation and suppressed cathepsin K and tartrate-resistant acid phosphatase (TRAP) expression via c-jun N-terminal kinase (JNK)/extracellular signal-regulated kinase (ERK)/p38-mediated c-Fos–nuclear factor of activated T cells, cytoplasmic 1 (NFATc1) signaling pathway. During osteoclast differentiation, the production of general reactive oxygen species (ROS) and superoxide anions was dose-dependently attenuated by scoparone. In addition, scoparone diminished NADPH (nicotinamide adenine dinucleotide phosphate) oxidase 1 (Nox1) expression and activation via the tumor necrosis factor receptor-associated factor 6 (TRAF6)–cSrc–phosphatidylinositol 3-kinase (PI3k) signaling pathway and prevented the disruption of mitochondrial electron transport chain system. Furthermore, scoparone augmented the expression of superoxide dismutase 1 (SOD1) and catalase (CAT). The overall results indicate that the inhibitory effect of scoparone on RANKL-induced osteoclast differentiation is attributed to the suppressive effect on ROS and superoxide anion production by inhibiting Nox1 expression and activation and protecting the mitochondrial electron transport chain system and the scavenging effect of ROS resulting from elevated SOD1 and CAT expression. - Highlights: • Scoparone dose-dependently inhibited RANKL-induced osteoclast differentiation. • Scoparone diminished general ROS and superoxide anions in a dose-dependent manner. • Scoparone inhibited Nox1 expression and

  17. Electroosmotically induced hydraulic pumping on microchips: differential ion transport

    PubMed

    Culbertson; Ramsey; Ramsey

    2000-05-15

    The theory behind and operation of an electroosmotically induced hydraulic pump for microfluidic devices is reported. This microchip functional element consists of a tee intersection with one inlet channel and two outlet channels. The inlet channel is maintained at high voltage while one outlet channel is kept at ground and the other channel has no electric potential applied. A pressure-induced flow of buffer is created in both outlet channels of the tee by reducing electroosmosis in the ground channel relative to that of the inlet channel. Spatially selective reduction of electroosmosis is accomplished by coating the walls of the ground channel with a viscous polymer. The pump is shown to differentially transport ions down the two outlet channels. This ion discrimination ability of the pump is examined as a function of an analyte's electrophoretic velocity. In addition, we demonstrate that an anion can be rejected from the ground channel and made to flow only into the field-free channel if the electrophoretic velocity of the anion is greater than the pressure-generated flow in the ground channel. The velocity threshold at which anion rejection occurs can be selectively tuned by changing the flow resistance in the field-free channel relative to the ground channel.

  18. A generalized differential effective medium theory

    NASA Astrophysics Data System (ADS)

    Norris, A. N.; Callegari, A. J.; Sheng, P.

    A GENERALIZATION of the Differential Effective Medium approximation (DEM) is discussed. The new scheme is applied to the estimation of the effective permittivity of a two phase dielectric composite. Ordinary DEM corresponds to a realizable microgeometry in which the composite is built up incrementally through a process of homogenization, with one phase always in dilute suspension and the other phase associated with the percolating backbone. The generalization of DEM assumes a third phase which acts as a backbone. The other two phases are progressively added to the backbone such that each addition is in an effectively homogeneous medium. A canonical ordinary differential equation is derived which describes the change in material properties as a function of the volume concentration φ of the added phases in the composite. As φ→ 1, the Effective Medium Approximation (EMA) is obtained. For φ < 1, the result depends upon the backbone and the mixture path that is followed. The approach to EMA for φ ≊ 1 is analysed and a generalization of Archie's law for conductor-insulator composites is described. The conductivity mimics EMA above the percolation threshold and DEM as the conducting phase vanishes.

  19. Effects of the fish spawning inducer ovaprim on vasotocin receptor gene expression in brain and ovary of the catfish Heteropneustes fossilis with a note on differential transcript expression in ovarian follicles.

    PubMed

    Rawat, A; Chaube, R; Joy, K P

    2017-01-15

    Ovaprim (OVP), a commercial formulation of a salmon GnRH analogue and the dopamine receptor-2 blocker domperidone, is a successful spawning inducer for fish breeding. It induces a preovulatory surge in LH, which stimulates the synthesis of a maturation-inducing steroid (MIS, 17,20β-dihydroxy-4-pregnen-3-one) that initiates germinal vesicle breakdown (GVBD) and ovulation. Coincidently, the OVP treatment also stimulates vasotocin (VT) secretion in the brain and ovary of the catfish Heteropneustes fossilis that also stimulates the synthesis of the MIS. VT mediates its effect through V1- and V2-type receptors. In the present study in the catfish, we report that OVP stimulates the expression of VT receptor genes v1a1, v1a2 and v2a in the brain and ovary. A single intraperitoneal administration of OVP (0.5μL/g body weight) or incubation of post-vitellogenic ovarian follicles with 5μL/mL OVP, for 0, 4, 8, 12, 16, and 24h stimulated ovulation and GVBD, respectively, in a time-dependent manner. The OVP treatment in vivo stimulated brain VT receptor transcript levels 4h onwards. The peak expression was noticed at 12h (v1a1), 8 and 12h (v1a2), and 8, 12 and 16h (v2a), coinciding with FOM and ovulation. The VT receptor genes are expressed in the ovarian follicles compartmentally; both v1a1 and v1a2 are expressed in the isolated follicular layer (theca and granulosa) but absent in denuded oocytes. V2a is expressed in the denuded oocytes and not in the follicular layer. The OVP injection stimulated the v1a1 and v1a2 expression from 4h onwards in both intact follicle and isolated follicular layer, the peak expression was observed at 16h. The v2a expression was up-regulated in both intact follicles and denuded oocytes at 4h (denuded oocytes) or 8h (intact follicle) onwards with the peak expression at 12h and 16h (denuded oocytes) or at 16h (intact follicles). Under in vitro conditions, the OVP incubations elicited similar pattern of changes with the peak stimulation at 16h for

  20. Radiation-induced glioblastoma signaling cascade regulates viability, apoptosis and differentiation of neural stem cells (NSC).

    PubMed

    Ivanov, Vladimir N; Hei, Tom K

    2014-12-01

    Ionizing radiation alone or in combination with chemotherapy is the main treatment modality for brain tumors including glioblastoma. Adult neurons and astrocytes demonstrate substantial radioresistance; in contrast, human neural stem cells (NSC) are highly sensitive to radiation via induction of apoptosis. Irradiation of tumor cells has the potential risk of affecting the viability and function of NSC. In this study, we have evaluated the effects of irradiated glioblastoma cells on viability, proliferation and differentiation potential of non-irradiated (bystander) NSC through radiation-induced signaling cascades. Using media transfer experiments, we demonstrated significant effects of the U87MG glioblastoma secretome after gamma-irradiation on apoptosis in non-irradiated NSC. Addition of anti-TRAIL antibody to the transferred media partially suppressed apoptosis in NSC. Furthermore, we observed a dramatic increase in the production and secretion of IL8, TGFβ1 and IL6 by irradiated glioblastoma cells, which could promote glioblastoma cell survival and modify the effects of death factors in bystander NSC. While differentiation of NSC into neurons and astrocytes occurred efficiently with the corresponding differentiation media, pretreatment of NSC for 8 h with medium from irradiated glioblastoma cells selectively suppressed the differentiation of NSC into neurons, but not into astrocytes. Exogenous IL8 and TGFβ1 increased NSC/NPC survival, but also suppressed neuronal differentiation. On the other hand, IL6 was known to positively affect survival and differentiation of astrocyte progenitors. We established a U87MG neurosphere culture that was substantially enriched by SOX2(+) and CD133(+) glioma stem-like cells (GSC). Gamma-irradiation up-regulated apoptotic death in GSC via the FasL/Fas pathway. Media transfer experiments from irradiated GSC to non-targeted NSC again demonstrated induction of apoptosis and suppression of neuronal differentiation of NSC. In

  1. Sphingosine 1-phosphate receptor activation enhances BMP-2-induced osteoblast differentiation

    SciTech Connect

    Sato, Chieri; Iwasaki, Tsuyoshi; Kitano, Sachie; Tsunemi, Sachi; Sano, Hajime

    2012-06-22

    Highlights: Black-Right-Pointing-Pointer We investigated the role of S1P signaling for osteoblast differentiation. Black-Right-Pointing-Pointer Both S1P and FTY enhanced BMP-2-stimulated osteoblast differentiation by C2C12 cells. Black-Right-Pointing-Pointer S1P signaling enhanced BMP-2-stimulated Smad and ERK phosphorylation by C2C12 cells. Black-Right-Pointing-Pointer MEK/ERK signaling is a pathway underlying S1P signaling for osteoblast differentiation. -- Abstract: We previously demonstrated that sphingosine 1-phosphate (S1P) receptor-mediated signaling induced proliferation and prostaglandin productions by synovial cells from rheumatoid arthritis (RA) patients. In the present study we investigated the role of S1P receptor-mediated signaling for osteoblast differentiation. We investigated osteoblast differentiation using C2C12 myoblasts, a cell line derived from murine satellite cells. Osteoblast differentiation was induced by the treatment of bone morphogenic protein (BMP)-2 in the presence or absence of either S1P or FTY720 (FTY), a high-affinity agonist of S1P receptors. Osteoblast differentiation was determined by osteoblast-specific transcription factor, Runx2 mRNA expression, alkaline phosphatase (ALP) activity and osteocalcin production by the cells. Smad1/5/8 and extracellular signal-regulated kinase (ERK) 1/2 phosphorylation was examined by Western blotting. Osteocalcin production by C2C12 cells were determined by ELISA. Runx2 expression and ALP activity by BMP-2-stimulated C2C12 cells were enhanced by addition of either S1P or FTY. Both S1P and FTY enhanced BMP-2-induced ERK1/2 and Smad1/5/8 phosphorylation. The effect of FTY was stronger than that of S1P. S1P receptor-mediated signaling on osteoblast differentiation was inhibited by addition of mitogen-activated protein kinase/ERK kinase (MEK) 1/2 inhibitor, indicating that the S1P receptor-mediated MEK1/2-ERK1/2 signaling pathway enhanced BMP-2-Smad signaling. These results indicate that S1P

  2. Differential effects of glucocorticoids on energy homeostasis in Syrian hamsters.

    PubMed

    Solomon, Matia B; Sakai, Randall R; Woods, Stephen C; Foster, Michelle T

    2011-08-01

    Syrian hamsters, like many humans, increase food intake and body adiposity in response to stress. We hypothesized that glucocorticoids (cortisol and corticosterone) mediate these stress-induced effects on energy homeostasis. Because Syrian hamsters are dual secretors of cortisol and corticosterone, differential effects of each glucocorticoid on energy homeostasis were investigated. First, adrenal intact hamsters were injected with varying physiological concentrations of cortisol, corticosterone, or vehicle to emulate our previously published defeat regimens (i.e., 1 injection/day for 5 days). Neither food intake nor body weight was altered following glucocorticoid injections. Therefore, we investigated the effect of sustained glucocorticoid exposure on energy homeostasis. This was accomplished by implanting hamsters with supraphysiological steady-state pellets of cortisol, corticosterone, or cholesterol as a control. Cortisol, but not corticosterone, significantly decreased food intake, body mass, and lean and fat tissue compared with controls. Despite decreases in body mass and adiposity, cortisol significantly increased circulating free fatty acids, triglyceride, cholesterol, and hepatic triglyceride concentrations. Although corticosterone did not induce alterations in any of the aforementioned metabolic end points, Syrian hamsters were responsive to the effects of corticosterone since glucocorticoids both induced thymic involution and decreased adrenal mass. These findings indicate that cortisol is the more potent glucocorticoid in energy homeostasis in Syrian hamsters. However, the data suggest that cortisol alone does not mediate stress-induced increases in food intake or body mass in this species.

  3. Betulinic Acid Induces Apoptosis in Differentiated PC12 Cells Via ROS-Mediated Mitochondrial Pathway.

    PubMed

    Wang, Xi; Lu, Xiaocheng; Zhu, Ronglan; Zhang, Kaixin; Li, Shuai; Chen, Zhongjun; Li, Lixin

    2017-01-25

    Betulinic acid (BA), a pentacyclic triterpene of natural origin, has been demonstrated to have varied biologic activities including anti-viral, anti-inflammatory, and anti-malarial effects; it has also been found to induce apoptosis in many types of cancer. However, little is known about the effect of BA on normal cells. In this study, the effects of BA on normal neuronal cell apoptosis and the mechanisms involved were studied using differentiated PC12 cells as a model. Treatment with 50 μM BA for 24 h apparently induced PC12 cell apoptosis. In the early stage of apoptosis, the level of intracellular reactive oxygen species (ROS) increased. Afterwards, the loss of the mitochondrial membrane potential, the release of cytochrome c and the activation of caspase-3 occurred. Treatment with antioxidants could significantly reduce BA-induced PC12 cell apoptosis. In conclusion, we report for the first time that BA induced the mitochondrial apoptotic pathway in differentiated PC12 cells through ROS.

  4. Pattern formation induced by a differential shear flow

    NASA Astrophysics Data System (ADS)

    Stucchi, L.; Vasquez, Desiderio A.

    2013-02-01

    Fluid flow advecting one substance while others are immobilized can generate an instability in a homogeneous steady state of a reaction-diffusion-advection system. This differential-flow instability leads to the formation of steady spatial patterns in a moving reference frame. We study the effects of shear flow on this instability by considering two layers of fluid moving independently from each other, but allowing the substances to diffuse along and across the layers. We find that shear flow can generate instabilities even if the average flow velocity is zero for both substances. These instabilities are strongly dependent on which substance is advected by the shear flow. We explain these effects using the results of Taylor dispersion, where an effective diffusivity is enhanced by shear flow.

  5. Impaired neural differentiation potency by retinoic acid receptor-α pathway defect in induced pluripotent stem cells.

    PubMed

    Hou, Pei-Shan; Huang, Wen-Chin; Chiang, Wei; Lin, Wei-Che; Chien, Chung-Liang

    2014-12-01

    Induced pluripotent stem cells (iPSCs) are reprogrammed from somatic cells via ectopic gene expression and, similarly to embryonic stem cells (ESCs), possess powerful abilities to self-renew and differentiate into cells of various lineages. However, the neural differentiation potency of iPSCs remains unknown. In this study, we demonstrated the neural differentiation ability of iPSCs compared with ESCs using an retinoic acid (RA) induction system. The neural differentiation efficiency of iPSCs was obviously lower than that of ESCs. Retinoic acid receptor-α (RARα) was critical in the RA-induced neural differentiation of iPSCs, and the effect of RARα was confirmed by applying a specific RARα antagonist ER50891 to ESCs. These findings indicate that iPSCs do not possess the complete properties that ESCs have.

  6. NDRG1 contributes to retinoic acid-induced differentiation of leukemic cells.

    PubMed

    Chen, Su; Han, Yu-Hui; Zheng, Ying; Zhao, Meng; Yan, Hua; Zhao, Qiao; Chen, Guo-Qiang; Li, Dao

    2009-08-01

    N-Myc downstream-regulated gene 1 (NDRG1) protein has been shown to be up-regulated during leukemic cell differentiation induced by some differentiation-inducing agents such as all-trans retinoic acid (ATRA). However, the potential role of up-regulated NDRG1 in the event is greatly unknown. In this work, we show that inducible NDRG1 expression can drive leukemic U937 cells to undergo differentiation, while the knock-down of NDRG1 expression by specific small interfering RNA significantly antagonizes ATRA-induced differentiation of leukemic cells, proposing the role of NDRG1 in leukemic cell differentiation. Furthermore, our work shows that CCAAT/enhancer-binding protein beta (C/EBPbeta) and PU.1, which are important hematopoiesis-related transcription factors, may act as downstream effectors of NDRG1 in leukemic cell differentiation. Taking together, this study provides direct evidence for the role of NDRG1 protein in myeloid leukemic cell differentiation.

  7. Effect of Cuscuta chinensis glycoside on the neuronal differentiation of rat pheochromocytoma PC12 cells.

    PubMed

    Jian-Hui, Liu; Bo, Jiang; Yong-Ming, Bao; Li-Jia, An

    2003-08-01

    Exposure of rat pheochromocytoma PC12 cells to Cuscuta chinensis glycoside induced neuronal differentiation with resulting outgrowth of neurites and increase of acetylcholinesterase activity. A specific inhibitor of mitogen-activated protein kinase (MAPK) kinase, PD98059, prevented this effect of C. chinensis on PC12 cells. These results suggested that C. chinensis glycoside induced neuronal differentiation in PC12 cells linked to the mitogen-activated protein kinase signaling cascade.

  8. Steroid sex hormone dynamics during estradiol-17β induced gonadal differentiation in Paralichthys olivaceus (Teleostei)

    NASA Astrophysics Data System (ADS)

    Sun, Peng; You, Feng; Liu, Mengxia; Wu, Zhihao; Wen, Aiyun; Li, Jun; Xu, Yongli; Zhang, Peijun

    2010-03-01

    Steroid sex hormones, such as estradiol-17β (E2) and testosterone (T), are important regulators of sex change in fish. In this study, we examined the effects of E2 treatment on the dynamics of E2 and T during gonadal differentiation in the olive flounder Paralichthys olivaceus using histology and radioimmunoassay (RIA). Flounder larvae were divided into five groups (G0-G4), and fed with 0 (control), 0.2, 2, 20 and 100 mg E2/kg feed from 35 to 110 day post hatching (dph). Fish growth in the G1 and G2 groups was not significantly different from that of the control group ( P>0.05), while fish in the G3 and G4 groups were less active and showed growth depression and high mortality. The gonads of fish in the G3 and G4 groups were smaller and surrounded by hyperplastic connective tissue. The frequency of females in the G0-G4 groups was 54.5%, 75.0%, 100%, 100% and 93.3%, respectively. The RIA analyses of E2 and T showed that T levels decreased during gonadal differentiation, and increased slightly at the onset of ovarian differentiation, while E2 levels increased gradually and peaked at the onset of ovarian differentiation in the control group. In the E2-treated groups, T levels decreased before the onset of ovarian differentiation. E2 levels were high on the 48 dph, but declined to a lower level on the 54 dph, and then increased gradually during gonadal differentiation. And a sharp increase of E2 levels were observed in all E2-treated groups at the onset of ovarian differentiation. The data suggest that T and E2 play important roles during gonadal differentiation, and an E2 dose of 2 mg/kg feed could induce sex reversal in P. olivaceus.

  9. Mechanical forces induce odontoblastic differentiation of mesenchymal stem cells on three-dimensional biomimetic scaffolds.

    PubMed

    Miyashita, Shunro; Ahmed, Nermeen El Motaz Bellah; Murakami, Masashi; Iohara, Koichiro; Yamamoto, Tokunori; Horibe, Hiroshi; Kurita, Kenichi; Takano-Yamamoto, Teruko; Nakashima, Misako

    2017-02-01

    The mechanical induction of cell differentiation is well known. However, the effect of mechanical compression on odontoblastic differentiation remains to be elucidated. Thus, we first determined the optimal conditions for the induction of human dental pulp stem cells (hDPSCs) into odontoblastic differentiation in response to mechanical compression of three-dimensional (3D) scaffolds with dentinal tubule-like pores. The odontoblastic differentiation was evaluated by gene expression and confocal laser microscopy. The optimal conditions, which were: cell density, 4.0 × 10(5) cells/cm(2) ; compression magnitude, 19.6 kPa; and loading time, 9 h, significantly increased expression of the odontoblast-specific markers dentine sialophosphoprotein (DSPP) and enamelysin and enhanced the elongation of cellular processes into the pores of the membrane, a typical morphological feature of odontoblasts. In addition, upregulation of bone morphogenetic protein 7 (BMP7) and wingless-type MMTV integration site family member 10a (Wnt10a) was observed. Moreover, the phosphorylation levels of mitogen-activated protein kinases (MAPKs), extracellular signal-regulated kinase 1/2 (ERK1/2) and p38 were also enhanced by mechanical compression, indicating the involvement of the MAPK signalling pathway. It is noteworthy that human mesenchymal stem cells (MSCs) derived from bone marrow and amnion also differentiated into odontoblasts in response to the optimal mechanical compression, demonstrating the importance of the physical structure of the scaffold in odontoblastic differentiation. Thus, odontoblastic differentiation of hDPSCs is promoted by optimal mechanical compression through the MAPK signalling pathway and expression of the BMP7 and Wnt10a genes. The 3D biomimetic scaffolds with dentinal tubule-like pores were critical for the odontoblastic differentiation of MSCs induced by mechanical compression. Copyright © 2014 John Wiley & Sons, Ltd.

  10. Ouabain-Induced Signaling and Cell Survival in SK-N-SH Neuroblastoma Cells Differentiated by Retinoic Acid

    PubMed Central

    Akkuratov, Evgeny E.; Wu, Jian; Sowa, David; Shah, Zahoor A.; Liu, Lijun

    2015-01-01

    Ouabain stimulates activation of various signaling cascades such as protein kinase B (Akt) and Extracellular-signaling-regulated kinase 1/2 (ERK 1/2) in various cell lines. Retinoic acid (RA) is commonly used to induce neuroblastoma differentiation in cultures. Upon RA administration, human neuroblastoma cell line, SK-N-SH demonstrated neurite extensions, which is an indicator of neuronal cell differentiation. Here we report that ouabain-induced signaling is altered under the action of 1 μM RA in human neuroblastoma SK-N-SH cells. RA increased the expression of p110α subunit of phosphoinositide 3-kinase (PI3K), Akt and β1 subunit of Na+/K+-ATPase. Ouabain activated Akt and ERK 1/2 in differentiated SK-N-SH cells; this effect was not observed in non-differentiated SK-N-SH cells. Long-term incubation of non-differentiated SK-N-SH with 1 μM ouabain led to a decrease in the number of cells; this effect was reduced in differentiated SK-N-SH cells. Taken together, these results suggest that ouabain leads to cell death in neuroblastoma cells rather than neuronal cells due to the different response to ouabain manifested by activation of Akt and ERK 1/2. Highlights • RA increases the expression of p110α subunit of PI3K, Akt and β1 subunit of Na+/K+-ATPase • Ouabain induces activation of Akt and ERK 1/2 in differentiated SK-N-SH cells but not in non-differentiated cells • 1 μM ouabain leads to a decrease in the number of cells in non-differentiated SK-N-SH • Reduction of ouabain-induced cell death in differentiated SK-N-SH

  11. Experimental study of millimeter wave-induced differentiation of bone marrow mesenchymal stem cells into chondrocytes.

    PubMed

    Wu, Guang-Wen; Liu, Xian-Xiang; Wu, Ming-Xia; Zhao, Jin-Yan; Chen, Wen-Lie; Lin, Ru-Hui; Lin, Jiu-Mao

    2009-04-01

    Low power millimeter wave irradiation is widely used in clinical medicine. We describe the effects of this treatment on cultured mesenchymal stem cells (MSCs) and attempted to identify the underlying mechanism. Cells cultured using the whole marrow attachment culture method proliferated dispersedly or in clones. Flow cytometric analyses showed that the MSCs were CD90 positive, but negative for CD45. The negative control group (A) did not express detectable levels of Cbfa1 or Sox9 mRNA at any time point, while cells in the millimeter wave-induced groups (B and C) increasingly expressed both genes after the fourth day post-induction. Statistical analysis showed that starting on the fourth day post-induction, there were very significant differences in the expression of Cbfa1 and Sox9 mRNA between groups A and B as well as A and C at any given time point, between treated groups B and C after identical periods of induction, and within each treated group at different induction times. Transition electron microscopy analysis showed that the rough endoplasmic reticulum of cells in the induced groups was richer and more developed than in cells of the negative control group, and that the shape of cells shifted from long-spindle to near ellipse. Toluidine blue staining revealed heterochromia in the cytoplasm and extracellular matrix of cells in the induced groups, whereas no obvious heterochromia was observed in negative control cells. Induced cells also exhibited positive immunohistochemical staining of collagen II, in contrast to the negative controls. These results show that millimeter wave treatment successfully induced MSCs to differentiate as chondrocytes and the extent of differentiation increased with treatment duration. Our findings suggest that millimeter wave irradiation can be employed as a novel non-drug inducing method for the differentiation of MSCs into chondrocytes.

  12. Activated Wnt signaling induces myofibroblast differentiation of mesenchymal stem cells, contributing to pulmonary fibrosis.

    PubMed

    Sun, Zhaorui; Wang, Cong; Shi, Chaowen; Sun, Fangfang; Xu, Xiaomeng; Qian, Weiping; Nie, Shinan; Han, Xiaodong

    2014-05-01

    Acute lung injury may lead to fibrogenesis. However, no treatment is currently available. This study was conducted to determine the effects of bone marrow-derived mesenchymal stem cells (MSCs) in a model of HCl-induced acute lung injury in Sprague-Dawley (SD) rats. Stromal cell-derived factor (SDF)-1 and its receptor CXC chemokine receptor (CXCR)4 have been shown to participate in mobilizing MSCs. Adenovirus carrying the CXCR4 gene was used to transfect MSCs in order to increase the engraftment numbers of MSCs at injured sites. Histological examination data demonstrated that the engraftment of MSCs did not attenuate lung injury and pulmonary fibrosis. The results showed that engraftment of MSCs almost differentiated into myofibroblasts, but rarely differentiated into lung epithelial cells. Additionally, it was demonstrated that activated canonical Wnt/β-catenin signaling in injured lung tissue regulated the myofibroblast differentiation of MSCs in vivo. The in vitro study results demonstrated that activation of the Wnt/β-catenin signaling stimulated MSCs to express myofibroblast markers; however, this process was attenuated by Wnt antagonist DKK1. Therefore, the results demonstrated that the aberrant activation of Wnt signaling induces the myofibroblast differentiation of engrafted MSCs, thus contributing to pulmonary fibrosis following lung injury.

  13. Gene expression profiling of human neural progenitor cells following the serum-induced astrocyte differentiation.

    PubMed

    Obayashi, Shinya; Tabunoki, Hiroko; Kim, Seung U; Satoh, Jun-ichi

    2009-05-01

    Neural stem cells (NSC) with self-renewal and multipotent properties could provide an ideal cell source for transplantation to treat spinal cord injury, stroke, and neurodegenerative diseases. However, the majority of transplanted NSC and neural progenitor cells (NPC) differentiate into astrocytes in vivo under pathological environments in the central nervous system, which potentially cause reactive gliosis. Because the serum is a potent inducer of astrocyte differentiation of rodent NPC in culture, we studied the effect of the serum on gene expression profile of cultured human NPC to identify the gene signature of astrocyte differentiation of human NPC. Human NPC spheres maintained in the serum-free culture medium were exposed to 10% fetal bovine serum (FBS) for 72 h, and processed for analyzing on a Whole Human Genome Microarray of 41,000 genes, and the microarray data were validated by real-time RT-PCR. The serum elevated the levels of expression of 45 genes, including ID1, ID2, ID3, CTGF, TGFA, METRN, GFAP, CRYAB and CSPG3, whereas it reduced the expression of 23 genes, such as DLL1, DLL3, PDGFRA, SOX4, CSPG4, GAS1 and HES5. Thus, the serum-induced astrocyte differentiation of human NPC is characterized by a counteraction of ID family genes on Delta family genes. Coimmunoprecipitation analysis identified ID1 as a direct binding partner of a proneural basic helix-loop-helix (bHLH) transcription factor MASH1. Luciferase assay indicated that activation of the DLL1 promoter by MASH1 was counteracted by ID1. Bone morphogenetic protein 4 (BMP4) elevated the levels of ID1 and GFAP expression in NPC under the serum-free culture conditions. Because the serum contains BMP4, these results suggest that the serum factor(s), most probably BMP4, induces astrocyte differentiation by upregulating the expression of ID family genes that repress the proneural bHLH protein-mediated Delta expression in human NPC.

  14. Human mesenchymal stromal cell-secreted lactate induces M2-macrophage differentiation by metabolic reprogramming

    PubMed Central

    Civini, Sara; Pacelli, Consiglia; Dieng, Mame Massar; Lemieux, William; Jin, Ping; Bazin, Renée; Patey, Natacha; Marincola, Francesco M.; Moldovan, Florina; Zaouter, Charlotte; Trudeau, Louis-Eric; Benabdhalla, Basma; Louis, Isabelle; Beauséjour, Christian; Stroncek, David; Le Deist, Françoise; Haddad, Elie

    2016-01-01

    Human mesenchymal stromal cells (MSC) have been shown to dampen immune response and promote tissue repair, but the underlying mechanisms are still under investigation. Herein, we demonstrate that umbilical cord-derived MSC (UC-MSC) alter the phenotype and function of monocyte-derived dendritic cells (DC) through lactate-mediated metabolic reprogramming. UC-MSC can secrete large quantities of lactate and, when present during monocyte-to-DC differentiation, induce instead the acquisition of M2-macrophage features in terms of morphology, surface markers, migratory properties and antigen presentation capacity. Microarray expression profiling indicates that UC-MSC modify the expression of metabolic-related genes and induce a M2-macrophage expression signature. Importantly, monocyte-derived DC obtained in presence of UC-MSC, polarize naïve allogeneic CD4+ T-cells into Th2 cells. Treatment of UC-MSC with an inhibitor of lactate dehydrogenase strongly decreases lactate concentration in culture supernatant and abrogates the effect on monocyte-to-DC differentiation. Metabolic analysis further revealed that UC-MSC decrease oxidative phosphorylation in differentiating monocytes while strongly increasing the spare respiratory capacity proportional to the amount of secreted lactate. Because both MSC and monocytes are recruited in vivo at the site of tissue damage and inflammation, we propose the local increase of lactate concentration induced by UC-MSC and the consequent enrichment in M2-macrophage generation as a mechanism to achieve immunomodulation. PMID:27070086

  15. Cholesterol starvation induces differentiation of the intestinal parasite Giardia lamblia.

    PubMed Central

    Luján, H D; Mowatt, M R; Byrd, L G; Nash, T E

    1996-01-01

    Giardia lamblia, like most human intestinal parasitic protozoa, sustains fundamental morphological and biochemical changes to survive outside the small intestine of its mammalian host by differentiating into an infective cyst. However, the stimulus that triggers this differentiation remains totally undefined. In this work, we demonstrate the induction of cyst formation in vitro when trophozoites are starved for cholesterol. Expression of cyst wall proteins was detected within encystation-specific secretory vesicles 90 min after the cells were placed in lipoprotein-deficient TYI-S-33 medium. Four cloned lines derived from two independent Giardia isolates were tested, and all formed cysts similarly. Addition of cholesterol, low density or very low density lipoproteins to the lipoprotein-deficient culture medium, inhibited the expression of cyst wall proteins, the generation of encystation-specific vesicles, and cyst wall biogenesis. In contrast, high density lipoproteins, phospholipids, bile salts, or fatty acids had little or no effect. These results indicate that cholesterol starvation is necessary and sufficient for the stimulation of Giardia encystation in vitro and, likely, in the intestine of mammalian hosts. Images Fig. 1 Fig. 4 Fig. 5 PMID:8755526

  16. Statins activate GATA-6 and induce differentiated vascular smooth muscle cells

    SciTech Connect

    Wada, Hiromichi Abe, Mitsuru; Ono, Koh; Morimoto, Tatsuya; Kawamura, Teruhisa; Takaya, Tomohide; Satoh, Noriko; Fujita, Masatoshi; Kita, Toru; Shimatsu, Akira; Hasegawa, Koji

    2008-10-03

    The beneficial effects of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) beyond cholesterol lowering involve their direct actions on vascular smooth muscle cells (VSMCs). However, the effects of statins on phenotypic modulation of VSMCs are unknown. We herein show that simvastatin (Sm) and atorvastatin (At) inhibited DNA synthesis in human aortic VSMCs dose-dependently, while cell toxicity was not observed below the concentration of 1 {mu}M of Sm or 100 nM of At. Stimulating proliferative VSMCs with Sm or At induced the expression of SM-{alpha}-actin and SM-MHC, highly specific markers of differentiated phenotype. Sm up-regulated the binding activity of GATA-6 to SM-MHC GATA site and activated the transfected SM-MHC promoter in proliferative VSMCs, while mutating the GATA-6 binding site abolished this activation. Geranylgeranylpyrophosphate (10 {mu}M), an inhibitor of Rho family proteins, abolished the statin-mediated induction of the differentiated phenotype in VSMCs. These findings suggest that statins activate GATA-6 and induce differentiated VSMCs.

  17. Dendritic cells enhance UHMWPE wear particle-induced osteoclast differentiation of macrophages.

    PubMed

    Cang, Dingwei; Guo, Kaijin; Zhao, Fengchao

    2015-10-01

    Ultra-high molecular weight polyethylene (UHMWPE) has been widely used in large joint replacement. Osteolysis induced by the UHMWPE wear particles is one of the main causes of replacement failure. This study aims to elucidate whether dendritic cells play a role in UHMWPE particle-induced osteolysis. An in vitro Raw 264.7 and DC 2.4 coculture system was employed to examine the effects of dendritic cells on the inflammatory and osteoclastogenic responses of Raw 264.7 toward UHMWPE particles. The expression of cytokines, NF-κB, and osteoclast marker genes was analyzed by ELISA, western blot, or quantitative PCR. The osteoclast differentiation was measured by TRAP staining and flow cytometry. UHMWPE particles induced Raw 264.7 cells to differentiate into osteoclasts, which was enhanced by coculturing with DC 2.4 cells. DC 2.4 cells augmented UHMWPE particle-elicited activation of NF-κB signaling, higher levels of TNF-α and MCP-1, and an increased expression of MMP-9, Calcr, and Ctsk, though DC 2.4 coculture alone did not significantly cause the aforementioned changes. These results suggest that dendritic cells, among other immune cells recruited by UHMWPE particle induced inflammation, could further exacerbate inflammation and osteolysis.

  18. The Dictyostelium prestalk inducer differentiation-inducing factor-1 (DIF-1) triggers unexpectedly complex global phosphorylation changes

    PubMed Central

    Sugden, Chris; Urbaniak, Michael D.; Araki, Tsuyoshi; Williams, Jeffrey G.

    2015-01-01

    Differentiation-inducing factor-1 (DIF-1) is a polyketide that induces Dictyostelium amoebae to differentiate as prestalk cells. We performed a global quantitative screen for phosphorylation changes that occur within the first minutes after addition of DIF-1, using a triple-label SILAC approach. This revealed a new world of DIF-1–controlled signaling, with changes in components of the MAPK and protein kinase B signaling pathways, components of the actinomyosin cytoskeletal signaling networks, and a broad range of small GTPases and their regulators. The results also provide evidence that the Ca2+/calmodulin–dependent phosphatase calcineurin plays a role in DIF-1 signaling to the DimB prestalk transcription factor. At the global level, DIF-1 causes a major shift in the phosphorylation/dephosphorylation equilibrium toward net dephosphorylation. Of interest, many of the sites that are dephosphorylated in response to DIF-1 are phosphorylated in response to extracellular cAMP signaling. This accords with studies that suggest an antagonism between the two inducers and also with the rapid dephosphorylation of the cAMP receptor that we observe in response to DIF-1 and with the known inhibitory effect of DIF-1 on chemotaxis to cAMP. All MS data are available via ProteomeXchange with identifier PXD001555. PMID:25518940

  19. Effects of parabens on adipocyte differentiation.

    PubMed

    Hu, Pan; Chen, Xin; Whitener, Rick J; Boder, Eric T; Jones, Jeremy O; Porollo, Aleksey; Chen, Jiangang; Zhao, Ling

    2013-01-01

    Parabens are a group of alkyl esters of p-hydroxybenzoic acid that include methylparaben, ethylparaben, propylparaben, butylparaben, and benzylparaben. Paraben esters and their salts are widely used as preservatives in cosmetics, toiletries, food, and pharmaceuticals. Humans are exposed to parabens through the use of such products from dermal contact, ingestion, and inhalation. However, research on the effects of parabens on health is limited, and the effects of parabens on adipogenesis have not been systematically studied. Here, we report that (1) parabens promote adipogenesis (or adipocyte differentiation) in murine 3T3-L1 cells, as revealed by adipocyte morphology, lipid accumulation, and mRNA expression of adipocyte-specific markers; (2) the adipogenic potency of parabens is increased with increasing length of the linear alkyl chain in the following potency ranking order: methyl- < ethyl- < propyl- < butylparaben. The extension of the linear alkyl chain with an aromatic ring in benzylparaben further augments the adipogenic ability, whereas 4-hydroxybenzoic acid, the common metabolite of all parabens, and the structurally related benzoic acid (without the OH group) are inactive in promoting 3T3-L1 adipocyte differentiation; (3) parabens activate glucocorticoid receptor and/or peroxisome proliferator-activated receptor γ in 3T3-L1 preadipocytes; however, no direct binding to, or modulation of, the ligand binding domain of the glucocorticoid receptor by parabens was detected by glucocorticoid receptor competitor assays; and lastly, (4) parabens, butyl- and benzylparaben in particular, also promote adipose conversion of human adipose-derived multipotent stromal cells. Our results suggest that parabens may contribute to obesity epidemic, and the role of parabens in adipogenesis in vivo needs to be examined further.

  20. K(ATP) channel block prevents proteasome inhibitor-induced apoptosis in differentiated PC12 cells.

    PubMed

    Nam, Yoon Jeong; Lee, Da Hee; Lee, Min Sung; Lee, Chung Soo

    2015-10-05

    Dysfunction of the proteasome system has been suggested to be implicated in neuronal degeneration. Modulation of KATP channels appears to affect the viability of neuronal cells exposed to toxic insults. However, the effect of KATP channel blockers on the neuronal cell death mediated by proteasome inhibition has not been studied. The present study investigated the effect of KATP channel blockers on proteasome inhibitor-induced apoptosis in differentiated PC12 cells and SH-SY5Y cells. 5-Hydroxydecanoate (a selective KATP channel blocker) and glibenclamide (a cell surface and mitochondrial KATP channel inhibitor) reduced the proteasome inhibitor-induced apoptosis. Addition of the KATP channel blockers attenuated the proteasome inhibitor-induced changes in the levels of apoptosis-related proteins, the loss of the mitochondrial transmembrane potential, the increase in the formation of reactive oxygen species and the depletion of glutathione in both cell lines. The results show that KATP channel blockers may attenuate proteasome inhibitor-induced apoptosis in PC12 cells by suppressing activation of the mitochondrial pathway and of the caspase-8- and Bid-dependent pathways. The preventive effect appears to be associated with the inhibition of the formation of reactive oxygen species and the depletion of glutathione. KATP channel blockade appears to prevent proteasome inhibition-induced neuronal cell death.

  1. Neurogenic differentiation factor NeuroD confers protection against radiation-induced intestinal injury in mice

    PubMed Central

    Li, Ming; Du, Aonan; Xu, Jing; Ma, Yanchao; Cao, Han; Yang, Chao; Yang, Xiao-Dong; Xing, Chun-Gen; Chen, Ming; Zhu, Wei; Zhang, Shuyu; Cao, Jianping

    2016-01-01

    The gastrointestinal tract, especially the small intestine, is particularly sensitive to radiation, and is prone to radiation-induced injury as a result. Neurogenic differentiation factor (NeuroD) is an evolutionarily-conserved basic helix-loop-helix (bHLH) transcription factor. NeuroD contains a protein transduction domain (PTD), which allows it to be exogenously delivered across the membrane of mammalian cells, whereupon its transcription activity can be unleashed. Whether NeuroD has therapeutic effects for radiation-induced injury remains unclear. In the present study, we prepared a NeuroD-EGFP recombinant protein, and explored its protective effects on the survival and intestinal damage induced by ionizing radiation. Our results showed that NeuroD-EGFP could be transduced into small intestine epithelial cells and tissues. NeuroD-EGFP administration significantly increased overall survival of mice exposed to lethal total body irradiation (TBI). This recombinant NeuroD also reduced radiation-induced intestinal mucosal injury and apoptosis, and improved crypt survival. Expression profiling of NeuroD-EGFP-treated mice revealed upregulation of tissue inhibitor of metalloproteinase 1 (TIMP-1), a known inhibitor of apoptosis in mammalian cells. In conclusion, NeuroD confers protection against radiation-induced intestinal injury, and provides a novel therapeutic clinical option for the prevention of intestinal side effects of radiotherapy and the treatment of victims of incidental exposure. PMID:27436572

  2. Basal cell induced differentiation of noncancerous prostate epithelial cells (RWPE-1) by glycitein.

    PubMed

    Clubbs, Elizabeth A; Bomser, Joshua A

    2009-01-01

    Increased consumption of soy and soy isoflavones is associated with a reduced risk for prostate cancer (PCa). PCa progression is characterized, in part, by a loss of luminal/basal epithelial differentiation; however, the effects of soy isoflavones on cellular differentiation in the prostate are unknown. The present study examined the effects of the soy isoflavone glycitein on cellular differentiation in prostate epithelial cells (RWPE-1, WPE1-NB14, and RWPE-2). Glycitein significantly inhibited RWPE-1 cellular proliferation at concentrations ranging from 0.4 to 50 microM. Expression of the luminal epithelial cell marker cytokeratin 18 was not affected by glycitein treatment in the WPE1-NB14 and RWPE-2 cell lines. However, expression of cytokeratin 18 and prostate specific antigen (PSA) was decreased in the RWPE-1 cell line in response to glycitein treatment, whereas the expression of the basal epithelial cell markers p63 and cytokeratin 5 remained unchanged. These data suggest that glycitein may induce basal cell differentiation in the RWPE-1 cell line.

  3. Differential effect of weight loss with low-fat diet or high-fat diet restriction on inflammation in the liver and adipose tissue of mice with diet-induced obesity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We studied the effects of weight loss induced by either a low-fat normal diet or restriction of high-fat diet on hepatic steatosis, inflammation in the liver and adipose tissue, and blood monocytes of obese mice. In mice with high-fat diet-induced obesity, weight loss was achieved by switching from ...

  4. ERK2-Pyruvate Kinase Axis Permits Phorbol 12-Myristate 13-Acetate-induced Megakaryocyte Differentiation in K562 Cells*

    PubMed Central

    Chaman, Noor; Iqbal, Mohammad Askandar; Siddiqui, Farid Ahmad; Gopinath, Prakasam; Bamezai, Rameshwar N. K.

    2015-01-01

    Metabolic changes that contribute to differentiation are not well understood. Overwhelming evidence shows the critical role of glycolytic enzyme pyruvate kinase (PK) in directing metabolism of proliferating cells. However, its role in metabolism of differentiating cells is unclear. Here we studied the role of PK in phorbol 12-myristate 13-acetate (PMA)-induced megakaryocytic differentiation in human leukemia K562 cells. We observed that PMA treatment decreased cancer-type anabolic metabolism but increased ATP production, along with up-regulated expression of two PK isoforms (PKM2 and PKR) in an ERK2-dependent manner. Interestingly, silencing of PK (PKM2 and PKR) inhibited PMA-induced megakaryocytic differentiation, as revealed by decreased expression of megakaryocytic differentiation marker CD61 and cell cycle behavior. Further, PMA-induced ATP production reduced greatly upon PK silencing, suggesting that PK is required for ATP synthesis. In addition to metabolic effects, PMA treatment also translocated PKM2, but not PKR, into nucleus. ERK1/2 knockdowns independently and together suggested the role of ERK2 in the up-regulation of both the isoforms of PK, proposing a role of ERK2-PK isoform axis in differentiation. Collectively, our findings unravel ERK2 guided PK-dependent metabolic changes during PMA induction, which are important in megakaryocytic differentiation. PMID:26269597

  5. ERK2-Pyruvate Kinase Axis Permits Phorbol 12-Myristate 13-Acetate-induced Megakaryocyte Differentiation in K562 Cells.

    PubMed

    Chaman, Noor; Iqbal, Mohammad Askandar; Siddiqui, Farid Ahmad; Gopinath, Prakasam; Bamezai, Rameshwar N K

    2015-09-25

    Metabolic changes that contribute to differentiation are not well understood. Overwhelming evidence shows the critical role of glycolytic enzyme pyruvate kinase (PK) in directing metabolism of proliferating cells. However, its role in metabolism of differentiating cells is unclear. Here we studied the role of PK in phorbol 12-myristate 13-acetate (PMA)-induced megakaryocytic differentiation in human leukemia K562 cells. We observed that PMA treatment decreased cancer-type anabolic metabolism but increased ATP production, along with up-regulated expression of two PK isoforms (PKM2 and PKR) in an ERK2-dependent manner. Interestingly, silencing of PK (PKM2 and PKR) inhibited PMA-induced megakaryocytic differentiation, as revealed by decreased expression of megakaryocytic differentiation marker CD61 and cell cycle behavior. Further, PMA-induced ATP production reduced greatly upon PK silencing, suggesting that PK is required for ATP synthesis. In addition to metabolic effects, PMA treatment also translocated PKM2, but not PKR, into nucleus. ERK1/2 knockdowns independently and together suggested the role of ERK2 in the up-regulation of both the isoforms of PK, proposing a role of ERK2-PK isoform axis in differentiation. Collectively, our findings unravel ERK2 guided PK-dependent metabolic changes during PMA induction, which are important in megakaryocytic differentiation.

  6. Chloroquine enhances cobalt chloride-induced leukemic cell differentiation via the suppression of autophagy at the late phase.

    PubMed

    Yan, Zhao-Wen; Hou, Jia-Kai; He, Wei; Fan, Li; Huang, Ying

    2013-01-18

    We previously reported that moderate hypoxia and hypoxia-mimetic agents including cobalt chloride (CoCl(2)) induce differentiation of human acute myeloid leukemia (AML) cells through hypoxia-inducible factor-1 α (HIF-1 α), which interacts with and enhances transcriptional activity of CCAAT-enhancer binding factor alpha and Runx1/AML1, two important transcriptional factors for hematopoietic cell differentiation. Here, we show that autophagy inhibitor chloroquine (CQ) increases HIF-1 α accumulation, thus potentiating CoCl(2)-induced growth arrest and differentiation of leukemic cells. Furthermore, the increased effect of CQ on differentiation induction is dependent of the inhibition of autophagosome maturation and degradation, since this sensitization could be mimicked by the suppression of expression of both lysosome-associated membrane proteins 1 and 2 (LAMP1 and LAMP2). These findings not only provide the evidence that CQ is a sensitizer for CoCl(2)-induced differentiation of leukemic cells but also possibly propose the new therapeutic strategy for differentiation induction of AML.

  7. VINCLOZOLIN (V) TREATMENT INDUCES REPRODUCTIVE MALFORMATIONS AND INFERTILITY IN F1 MALE RATS WHEN ADMINISTERED DURING SEXUAL BUT NOT GONADAL DIFFERENTIATION. THE EFFECTS ARE NOT TRANSMITTED TO THE SUBSEQUENT GENERATIONS.

    EPA Science Inventory

    V produces adverse reproductive effects in male rats when administered during sexual differentiation by acting as an androgen-antagonist. It was recently reported that four generations of SD rats, derived from dams dosed via ip injection GD8-15 with 100 mg V/kg/day, displayed pro...

  8. Proteomics unveil corticoid-induced S100A11 shuttling in keratinocyte differentiation

    SciTech Connect

    Dezitter, Xavier; Hammoudi, Fatma; Belverge, Nicolas; Deloulme, Jean-Christophe; Drobecq, Herve; Masselot, Bernadette; Formstecher, Pierre; Mendy, Denise; Idziorek, Thierry . E-mail: thierry.idziorek@lille.inserm.fr

    2007-08-31

    Unlike classical protein extraction techniques, proteomic mapping using a selective subcellular extraction kit revealed S100A11 as a new member of the S100 protein family modulated by glucocorticoids in keratinocytes. Glucocorticoids (GC)-induced S100A11 redistribution in the 'organelles and membranes' compartment. Microscopic examination indicated that glucocorticoids specifically routed cytoplasmic S100A11 toward perinuclear compartment. Calcium, a key component of skin terminal differentiation, directed S100A11 to the plasma membrane as previously reported. When calcium was added to glucocorticoids, minor change was observed at the proteomic level while confocal microscopy revealed a rapid and dramatic translocation of S100A11 toward plasma membrane. This effect was accompanied by strong nuclear condensation, loss of mitochondrial potential and DNA content, and increased high molecular weight S100A11 immunoreactivity, suggesting corticoids accelerate calcium-induced terminal differentiation. Finally, our results suggest GC-induced S100A11 relocalization could be a key step in both keratinocyte homeostasis and glucocorticoids side effects in human epidermis.

  9. Identification of Pathways Mediating Growth Differentiation Factor5-Induced Tenogenic Differentiation in Human Bone Marrow Stromal Cells.

    PubMed

    Tan, Sik-Loo; Ahmad, Tunku Sara; Ng, Wuey-Min; Azlina, Amir Abbas; Azhar, Mahmood Merican; Selvaratnam, Lakshmi; Kamarul, Tunku

    2015-01-01

    To date, the molecular signalling mechanisms which regulate growth factors-induced MSCs tenogenic differentiation remain largely unknown. Therefore, a study to determine the global gene expression profile of tenogenic differentiation in human bone marrow stromal cells (hMSCs) using growth differentiation factor 5 (GDF5) was conducted. Microarray analyses were conducted on hMSCs cultures supplemented with 100 ng/ml of GDF5 and compared to undifferentiated hMSCs and adult tenocytes. Results of QuantiGene® Plex assay support the use and interpretation of the inferred gene expression profiles and pathways information. From the 27,216 genes assessed, 873 genes (3.21% of the overall human transcriptome) were significantly altered during the tenogenic differentiation process (corrected p<0.05). The genes identified as potentially associated with tenogenic differentiation were ARHGAP29, CCL2, integrin alpha 8 and neurofilament medium polypeptides. These genes, were mainly associated with cytoskeleton reorganization (stress fibers formation) signaling. Pathway analysis demonstrated the potential molecular pathways involved in tenogenic differentiation were: cytoskeleton reorganization related i.e. keratin filament signaling and activin A signaling; cell adhesion related i.e. chemokine and adhesion signaling; and extracellular matrix related i.e. arachidonic acid production signaling. Further investigation using atomic force microscopy and confocal laser scanning microscopy demonstrated apparent cytoskeleton reorganization in GDF5-induced hMSCs suggesting that cytoskeleton reorganization signaling is an important event involved in tenogenic differentiation. Besides, a reduced nucleostemin expression observed suggested a lower cell proliferation rate in hMSCs undergoing tenogenic differentiation. Understanding and elucidating the tenogenic differentiation signalling pathways are important for future optimization of tenogenic hMSCs for functional tendon cell-based therapy and

  10. Identification of Pathways Mediating Growth Differentiation Factor5-Induced Tenogenic Differentiation in Human Bone Marrow Stromal Cells

    PubMed Central

    Tan, Sik-Loo; Ahmad, Tunku Sara; Ng, Wuey-Min; Azlina, Amir Abbas; Azhar, Mahmood Merican; Selvaratnam, Lakshmi; Kamarul, Tunku

    2015-01-01

    To date, the molecular signalling mechanisms which regulate growth factors-induced MSCs tenogenic differentiation remain largely unknown. Therefore, a study to determine the global gene expression profile of tenogenic differentiation in human bone marrow stromal cells (hMSCs) using growth differentiation factor 5 (GDF5) was conducted. Microarray analyses were conducted on hMSCs cultures supplemented with 100 ng/ml of GDF5 and compared to undifferentiated hMSCs and adult tenocytes. Results of QuantiGene® Plex assay support the use and interpretation of the inferred gene expression profiles and pathways information. From the 27,216 genes assessed, 873 genes (3.21% of the overall human transcriptome) were significantly altered during the tenogenic differentiation process (corrected p<0.05). The genes identified as potentially associated with tenogenic differentiation were ARHGAP29, CCL2, integrin alpha 8 and neurofilament medium polypeptides. These genes, were mainly associated with cytoskeleton reorganization (stress fibers formation) signaling. Pathway analysis demonstrated the potential molecular pathways involved in tenogenic differentiation were: cytoskeleton reorganization related i.e. keratin filament signaling and activin A signaling; cell adhesion related i.e. chemokine and adhesion signaling; and extracellular matrix related i.e. arachidonic acid production signaling. Further investigation using atomic force microscopy and confocal laser scanning microscopy demonstrated apparent cytoskeleton reorganization in GDF5-induced hMSCs suggesting that cytoskeleton reorganization signaling is an important event involved in tenogenic differentiation. Besides, a reduced nucleostemin expression observed suggested a lower cell proliferation rate in hMSCs undergoing tenogenic differentiation. Understanding and elucidating the tenogenic differentiation signalling pathways are important for future optimization of tenogenic hMSCs for functional tendon cell-based therapy and

  11. Electrospun biomaterial scaffolds with varied topographies for neuronal differentiation of human-induced pluripotent stem cells.

    PubMed

    Mohtaram, Nima Khadem; Ko, Junghyuk; King, Craig; Sun, Lin; Muller, Nathan; Jun, Martin Byung-Guk; Willerth, Stephanie M

    2015-08-01

    In this study, we investigated the effect of micro and nanoscale scaffold topography on promoting neuronal differentiation of human induced pluripotent stem cells (iPSCs) and directing the resulting neuronal outgrowth in an organized manner. We used melt electrospinning to fabricate poly (ε-caprolactone) (PCL) scaffolds with loop mesh and biaxial aligned microscale topographies. Biaxial aligned microscale scaffolds were further functionalized with retinoic acid releasing PCL nanofibers using solution electrospinning. These scaffolds were then seeded with neural progenitors derived from human iPSCs. We found that smaller diameter loop mesh scaffolds (43.7 ± 3.9 µm) induced higher expression of the neural markers Nestin and Pax6 compared to thicker diameter loop mesh scaffolds (85 ± 4 µm). The loop mesh and biaxial aligned scaffolds guided the neurite outgrowth of human iPSCs along the topographical features with the maximum neurite length of these cells being longer on the biaxial aligned scaffolds. Finally, our novel bimodal scaffolds also supported the neuronal differentiation of human iPSCs as they presented both physical and chemical cues to these cells, encouraging their differentiation. These results give insight into how physical and chemical cues can be used to engineer neural tissue.

  12. Induced differentiation of erythroleukemia cells by hexamethylene bisacetamide: a model for cytodifferentiation of transformed cells.

    PubMed Central

    Marks, P A; Rifkind, R A

    1989-01-01

    There is considerable evidence that malignant transformation need not eliminate the potential for a cell to express its developmental capabilities. This review explores the process whereby polar compounds, hexamethylene bisacetamide (HMBA) in particular, induce murine erythroid leukemoid cells (MELC) to express the differentiated erythroid phenotype, including hemoglobin production and cessation of cell division. This is a multi-step process which, although the mechanisms of action of HMBA are not yet fully understood, is amenable to experimental definition and analysis. Early effects, including changes in protein kinase C activity, in ion transport, and in expression of certain nuclear proto-oncogenes, have been examined in relation to the onset of terminal cell differentiation. This experimental experience has formed the context for initiating preliminary clinical studies designed to examine the pharmacology of HMBA and to explore its potential for modifying the natural history of cancer. PMID:2647479

  13. The prelamin A pre-peptide induces cardiac and skeletal myoblast differentiation

    SciTech Connect

    Brodsky, Gary L. . E-mail: Gary.Brodsky@uchsc.edu; Bowersox, Jeffrey A.; Fitzgerald-Miller, Lisa; Miller, Leslie A.; Maclean, Kenneth N.

    2007-05-18

    Prelamin A processing is unique amongst mammalian proteins and results in the production of a farnesylated and carboxymethylated peptide. We examined the effect of pathogenic LMNA mutations on prelamin A processing, and of the covalently modified peptide on cardiac and skeletal myoblast differentiation. Here we report a mutation associated with dilated cardiomyopathy prevents prelamin A peptide production. In addition, topical application of the covalently modified C-terminal peptide to proliferating skeletal and cardiac myoblasts induced myotube and striated tissue formation, respectively. Western blot analysis revealed that skeletal and cardiac myoblasts are the first cell lines examined to contain unprocessed prelamin A, and immunostaining of peptide-treated cells revealed a previously unidentified role for prelamin A in cytoskeleton formation and intercellular organization. These results demonstrate a direct role for prelamin A in myoblast differentiation and indicate the prelamin A peptide may have therapeutic potential.

  14. Rethinking Differentiation--Using Teachers' Time Most Effectively

    ERIC Educational Resources Information Center

    Marshall, Kim

    2016-01-01

    The goals of differentiation are laudable, but in recent years, many question whether it is really possible for a teacher to tailor instruction for 20 to 30 different students and whether it's desirable to differentiate by learning styles. Differentiation is just one factor in effective instruction. Supervisors who walk into a classroom looking…

  15. Lipopolysaccharide induces proliferation and osteogenic differentiation of adipose-derived mesenchymal stromal cells in vitro via TLR4 activation.

    PubMed

    Herzmann, Nicole; Salamon, Achim; Fiedler, Tomas; Peters, Kirsten

    2017-01-01

    Multipotent mesenchymal stromal cells (MSC) are capable of multi-lineage differentiation and support regenerative processes. In bacterial infections, resident MSC can come intocontact with and need to react to bacterial components. Lipopolysaccharide (LPS), a typical structure of Gram-negative bacteria, increases the proliferation and osteogenic differentiation of MSC. LPS is usually recognized by the toll-like receptor (TLR) 4 and induces pro-inflammatory reactions in numerous cell types. In this study, we quantified the protein expression of TLR4 and CD14 on adipose-derived MSC (adMSC) in osteogenic differentiation and investigated the effect of TLR4 activation by LPS on NF-κB activation, proliferation and osteogenic differentiation of adMSC. We found that TLR4 is expressed on adMSC whereas CD14 is not, and that osteogenic differentiation induced an increase of the amount of TLR4 protein whereas LPS stimulation did not. Moreover, we could show that NF-κB activation via TLR4 occurs upon LPS treatment. Furthermore, we were able to show that competitive inhibition of TLR4 completely abolished the stimulatory effect of LPS on the proliferation and osteogenic differentiation of adMSC. In addition, the inhibition of TLR4 leads to the complete absence of osteogenic differentiation of adMSC, even when osteogenically stimulated. Thus, we conclude that LPS induces proliferation and osteogenic differentiation of adMSC in vitro through the activation of TLR4 and that the TLR4 receptor seems to play a role during osteogenic differentiation of adMSC.

  16. Lead-induced catalase activity differentially modulates behaviors induced by short-chain alcohols.

    PubMed

    Correa, M; Pascual, M; Sanchis-Segura, C; Guerri, C; Aragon, C M G

    2005-11-01

    Acute lead administration produces a transient increase in brain catalase activity. This effect of lead has been used to assess the involvement of brain ethanol metabolism, and therefore centrally formed acetaldehyde, in the behavioral actions of ethanol. In mice, catalase is involved in ethanol and methanol metabolism, but not in the metabolism of other alcohols such as 1-propanol or tert-butanol. In the present study, we assessed the specificity of the effects of lead acetate on catalase-mediated metabolism of alcohols, and the ability of lead to modulate the locomotion and loss of the righting reflex (LRR) induced by 4 different short-chain alcohols. Animals were pretreated i.p. with lead acetate (100 mg/kg) or saline, and 7 days later were injected i.p. with ethanol (2.5 or 4.5 g/kg), methanol (2.5 or 6.0 g/kg), 1-propanol (0.5 or 2.5 g/kg) or tert-butanol (0.5 or 2.0 g/kg) for locomotion and LRR, respectively. Locomotion induced by ethanol was significantly potentiated in lead-treated mice, while methanol-induced locomotion was reduced by lead treatment. The loss of righting reflex induced by ethanol was shorter in lead-treated mice, and lead produced the opposite effect in methanol-treated mice. There was no effect of lead on 1-propanol or tert-butanol-induced behaviors. Lead treatment was effective in inducing catalase activity and protein both in liver and brain. These results support the hypothesis that the effects of lead treatment on ethanol-induced behaviors are related to changes in catalase activity, rather than some nonspecific effect that generalizes to all alcohols.

  17. PI3K/AKT and ERK regulate retinoic acid-induced neuroblastoma cellular differentiation

    SciTech Connect

    Qiao, Jingbo; Paul, Pritha; Lee, Sora; Qiao, Lan; Josifi, Erlena; Tiao, Joshua R.; Chung, Dai H.

    2012-08-03

    Highlights: Black-Right-Pointing-Pointer Retinoic acid (RA) induces neuroblastoma cells differentiation, which is accompanied by G0/G1 cell cycle arrest. Black-Right-Pointing-Pointer RA resulted in neuroblastoma cell survival and inhibition of DNA fragmentation; this is regulated by PI3K pathway. Black-Right-Pointing-Pointer RA activates PI3K and ERK1/2 pathway; PI3K pathway mediates RA-induced neuroblastoma cell differentiation. Black-Right-Pointing-Pointer Upregulation of p21 is necessary for RA-induced neuroblastoma cell differentiation. -- Abstract: Neuroblastoma, the most common extra-cranial solid tumor in infants and children, is characterized by a high rate of spontaneous remissions in infancy. Retinoic acid (RA) has been known to induce neuroblastoma differentiation; however, the molecular mechanisms and signaling pathways that are responsible for RA-mediated neuroblastoma cell differentiation remain unclear. Here, we sought to determine the cell signaling processes involved in RA-induced cellular differentiation. Upon RA administration, human neuroblastoma cell lines, SK-N-SH and BE(2)-C, demonstrated neurite extensions, which is an indicator of neuronal cell differentiation. Moreover, cell cycle arrest occurred in G1/G0 phase. The protein levels of cyclin-dependent kinase inhibitors, p21 and p27{sup Kip}, which inhibit cell proliferation by blocking cell cycle progression at G1/S phase, increased after RA treatment. Interestingly, RA promoted cell survival during the differentiation process, hence suggesting a potential mechanism for neuroblastoma resistance to RA therapy. Importantly, we found that the PI3K/AKT pathway is required for RA-induced neuroblastoma cell differentiation. Our results elucidated the molecular mechanism of RA-induced neuroblastoma cellular differentiation, which may be important for developing novel therapeutic strategy against poorly differentiated neuroblastoma.

  18. Differential effects of planktonic and biofilm MRSA on human fibroblasts.

    PubMed

    Kirker, Kelly R; James, Garth A; Fleckman, Philip; Olerud, John E; Stewart, Philip S

    2012-01-01

    Bacteria colonizing chronic wounds often exist as biofilms, yet their role in chronic wound pathogenesis remains unclear. Staphylococcus aureus biofilms induce apoptosis in dermal keratinocytes, and given that chronic wound biofilms also colonize dermal tissue, it is important to investigate the effects of bacterial biofilms on dermal fibroblasts. The effects of a predominant wound pathogen, methicillin-resistant S. aureus, on normal, human, dermal fibroblasts were examined in vitro. Cell-culture medium was conditioned with equivalent numbers of either planktonic or biofilm methicillin-resistant S. aureus and then fed to fibroblast cultures. Fibroblast response was evaluated using scratch, viability, and apoptosis assays. The results suggested that fibroblasts experience the same fate when exposed to the soluble products of either planktonic or biofilm methicillin-resistant S. aureus, namely limited migration followed by death. Enzyme-linked immunosorbent assays demonstrated that fibroblast production of cytokines, growth factors, and proteases were differentially affected by planktonic and biofilm-conditioned medium. Planktonic-conditioned medium induced more interleukin-6, interleukin-8, vascular endothelial growth factor, transforming growth factor-β1, heparin-bound epidermal growth factor, matrix metalloproteinase-1, and metalloproteinase-3 production in fibroblasts than the biofilm-conditioned medium. Biofilm-conditioned medium induced more tumor necrosis factor-α production in fibroblasts compared with planktonic-conditioned medium, and suppressed metalloproteinase-3 production compared with controls.

  19. Functional immobilization of interferon-gamma induces neuronal differentiation of neural stem cells.

    PubMed

    Leipzig, Nic D; Xu, Changchang; Zahir, Tasneem; Shoichet, Molly S

    2010-05-01

    Stem cell transplantation provides significant promise to regenerative strategies after injury in the central nervous system. Neural stem/progenitor cells (NSPCs) have been studied in terms of their regenerative capacity and their ability to differentiate into neurons when exposed to various soluble factors. In this study, interferon-gamma (IFN-gamma) was compared with brain-derived neurotrophic factor (BDNF) and erythropoietin and was shown to be the best single growth factor for inducing neuronal differentiation from adult rat brain-derived NSPCs. Next, IFN-gamma was surface immobilized to a methacrylamide chitosan (MAC) scaffold that was specifically designed to match the modulus of brain tissue and neuronal differentiation of NSPCs was examined in vitro by immunohistochemistry. Bioactive IFN-gamma was successfully immobilized and quantified by ELISA. Both soluble and immobilized IFN-gamma on MAC surfaces showed dose dependent neuronal differentiation with soluble saturation occurring at 100 ng/mL and the most effective immobilized IFN-gamma dose at 37.5 ng/cm(2), where significantly more neurons resulted compared with controls including soluble IFN-gamma.

  20. RRD-251 enhances all-trans retinoic acid (RA)-induced differentiation of HL-60 myeloblastic leukemia cells

    PubMed Central

    Bunaciu, Rodica P.; Yen, Andrew

    2016-01-01

    All-trans-retinoic acid (RA) is known to induce terminal granulocytic differentiation and cell cycle arrest of HL-60 cells. Responding to an RA-induced cytosolic signaling machine, c-Raf translocates to the nucleus, providing propulsion for RA-induced differentiation. This novel mechanism is not understood, but presumably reflects c-Raf binding with nuclear gene regulatory proteins. RRD-251 is a small molecule that prevents the interaction of c-Raf and RB, the retinoblastoma tumor suppressor protein. The involvement of c-Raf and RB in RA-induced differentiation motivates interest in the effects of combined RA and RRD-251 treatment on leukemic cell differentiation. We demonstrate that RRD-251 enhances RA-induced differentiation. Mechanistically, we find that nuclear translocated c-Raf associates with pS608 RB. RA causes loss of pS608 RB, where cells with hypophosphorylated S608 RB are G0/G1 restricted. Corroborating the pS608 RB hypophosphorylation, RB sequestration of E2F increased with concomitant loss of cdc6 expression, which is known to be driven by E2F. Hypophosphorylation of S608 RB releases c-Raf from RB sequestration to bind other nuclear targets. Release of c-Raf from RB sequestration results in enhanced association with GSK-3 which is phosphorylated at its S21/9 inhibitory sites. c-Raf binding to GSK-3 is associated with dissociation of GSK-3 and RARα, thereby relieving RARα of GSK-3 inhibition. RRD-251 amplifies each of these RA-induced events. Consistent with the posited enhancement of RARα transcriptional activity by RRD-251, RRD-251 increases the RARE-driven CD38 expression per cell. The RA/c-Raf/GSK-3/RARα axis emerges as a novel differentiation regulatory mechanism susceptible to RRD-251, suggesting enhancing RA-effects with RRD-251 in therapy. PMID:27331409

  1. 10e12z CLA alters adipocyte differentiation and adipocyte cytokine expression and induces macrophage proliferation.

    PubMed

    Belda, Benjamin J; Thompson, Jerry T; Eser, Pinar O; Vanden Heuvel, John P

    2012-05-01

    The trans-10, cis-12 (10e12z) conjugated linoleic acid (CLA) isomer of CLA is responsible for loss of lipid storage or adipose tissue in vitro or in vivo. This isomer also induces inflammatory signaling in both mouse and human adipocytes in vitro. However, when these events occur and whether they are significant enough to affect other cell types are unclear. In these experiments, the 3T3-L1 cell line has been used to examine the interaction between inflammatory signaling and decreased differentiation or lipid storage induced by 10e12z CLA. In assays measuring both lipid accumulation and gene expression, differentiating 3T3-L1 cells exhibit concurrent induction of inflammatory signaling, as measured by cyclooxygenase-2 expression, and a decrease in adipocyte marker gene expression. Furthermore, in fully differentiated adipocytes, as identified in microarray assays and confirmed with real-time polymerase chain reaction, 10e12z CLA also significantly affected expression of both matrix metalloprotein-3 (MMP-3), collagen VI α 3 ColVI alpha 3 (VIα3) and the cytokine epiregulin, demonstrating that the effects of 10e12z broadly impact adipocyte function. In agreement with other experimental systems, 10e12z CLA inhibited RAW 264.7 cell proliferation; however, in response to adipocyte-conditioned media, 10e12z-CLA-treated adipocytes induced proliferation of this cell line, suggesting that the effect of 10e12z CLA is context dependent. These results are largely consistent with the known activation of the inflammatory mediator nuclear factor-κB in adipocytes in vitro and in vivo by 10e12z CLA treatment and demonstrate that adipose is an important target tissue of this isomer that impacts other cell types.

  2. Spirulina phycocyanin induces differential protein expression and apoptosis in SKOV-3 cells.

    PubMed

    Pan, Ruowang; Lu, Rongmao; Zhang, Ying; Zhu, Mei; Zhu, Wen; Yang, Rongrong; Zhang, Enyong; Ying, Jun; Xu, Teng; Yi, Huiguang; Li, Jinsong; Shi, Mengru; Zhou, Li; Xu, Zuyuan; Li, Peizhen; Bao, Qiyu

    2015-11-01

    The present study was designed to determine the effects of phycocyanin (PC) on Human ovarian cancer SKOV-3 cells and the underlying molecular mechanisms of action. The inhibitory effects of PC on the cell proliferation were detected by MTT assay. The IC50 values of PC were 182.0μM and 133.6μM for 24h and 48h exposure, respectively. PC induced apoptosis in SKOV-3 cells was observed by electron microscopy and flow cytometry. The apoptosis rate was increased from 1.6% to 19.8% after PC exposure. The fluorescence intensity of ROS and the activities of Caspase-3, Caspase-8, and Caspase-9 were increased. Differentiated expression protein spots were selected and identified using proteomic techniques. There were 698±73 and 683±79 protein spots resolved in untreated and PC-treated cells, respectively. Forty five differential protein spots were analyzed by MALDI-TOF-MS, including mtSSB, PSME3, and nucleolin. The mRNA expression profiles determined by RT-PCR were consistent with that of the two-dimensional electrophoresis. The decreased proteins such as HSP60, nucleolin, PPase, peroxiredoxin-4 and the increased protein (mtSSB) were identified in SKOV-3 cells after PC treatment, indicating that the effects of PC on tumor cell apoptosis may be relate to multiple target proteins. And the mitochondrial pathway may be the main pathway for PC-induced apoptosis.

  3. Olive (Olea europaea) leaf extract induces apoptosis and monocyte/macrophage differentiation in human chronic myelogenous leukemia K562 cells: insight into the underlying mechanism.

    PubMed

    Samet, Imen; Han, Junkyu; Jlaiel, Lobna; Sayadi, Sami; Isoda, Hiroko

    2014-01-01

    Differentiation therapy is an attractive approach aiming at reversing malignancy and reactivating endogenous differentiation programs in cancer cells. Olive leaf extract, known for its antioxidant activity, has been demonstrated to induce apoptosis in several cancer cells. However, its differentiation inducing properties and the mechanisms involved are still poorly understood. In this study, we investigated the effect of Chemlali Olive Leaf Extract (COLE) for its potential differentiation inducing effect on multipotent leukemia K562 cells. Results showed that COLE inhibits K562 cells proliferation and arrests the cell cycle at G0/G1, and then at G2/M phase over treatment time. Further analysis revealed that COLE induces apoptosis and differentiation of K562 cells toward the monocyte lineage. Microarray analysis was conducted to investigate the underlying mechanism of COLE differentiation inducing effect. The differentially expressed genes such as IFI16, EGR1, NFYA, FOXP1, CXCL2, CXCL3, and CXCL8 confirmed the commitment of K562 cells to the monocyte/macrophage lineage. Thus our results provide evidence that, in addition to apoptosis, induction of differentiation is one of the possible therapeutic effects of olive leaf in cancer cells.

  4. Contaminant effect on cellular metabolic differential pressure curves.

    PubMed

    Milani, Marziale; Ballerini, Monica; Ferraro, L; Zabeo, M; Barberis, M; Cannone, M; Faraone, V

    2004-01-01

    The possibility of a pressure monitoring system by differential pressure sensors to detect contaminant effects on cellular cultures metabolic activity is discussed using Saccharomyces cerevisiae, lymphocyte, and AHH1 cell cultures. Metabolic (aerobic and anaerobic) processes in cells are accompanied by CO(2) production that induces changes in pressure values when cells are cultured in sealed vessels. These values are subsequently converted in voltage units and plotted pressure dynamics versus time. This procedure leads to a standard curve, typical of the cellular line, which characterizes cellular metabolism when all parameters are controlled, such as temperature and nutrients. Different phases appear in the S. cerevisiae differential pressure curve: an initial growth up to a maximum, followed by a decrement that leads to a typical "depression" (pressure values inside the test-tubes are lower than the initial one) after about 35 h from the beginning. The S. cerevisiae differential pressure curve is successfully used to test the effects of chemical (Amuchina, trieline) and physical (UV radiation, blue light, magnetic fields) contaminants. The same technique is applied to lymphocytes and AHH1 cultures to investigate the effects generated by a 72-h exposure to a 50-Hz, 60-microT electromagnetic field. Lymphocyte samples, cultured in a PHA medium, grow less than control ones, but exhibit a greater metabolic activity: changes in the exposure system configuration influence neither sample growth differences nor metabolic response variations between control and irradiated samples, while all the other irradiation parameters remain constant. Control and irradiated lymphocyte samples, without PHA in culture medium, show the same behavior both during irradiation and metabolic test. AHH1 control and irradiated samples show no difference both in growth percentage during irradiation and in metabolic activity. Different cell cultures respond to the same stimulus in different

  5. BMP‐9‐induced osteogenic differentiation of mesenchymal progenitors requires functional canonical Wnt/β‐catenin signalling

    PubMed Central

    Tang, Ni; Song, Wen‐Xin; Luo, Jinyong; Luo, Xiaoji; Chen, Jin; Sharff, Katie A.; Bi, Yang; He, Bai‐Cheng; Huang, Jia‐Yi; Zhu, Gao‐Hui; Su, Yu‐Xi; Jiang, Wei; Tang, Min; He, Yun; Wang, Yi; Chen, Liang; Zuo, Guo‐Wei; Shen, Jikun; Pan, Xiaochuan; Reid, Russell R.; Luu, Hue H.; Haydon, Rex C.

    2008-01-01

    Abstract Bone morphogenetic protein 9 (BMP‐9) is a member of the transforming growth factor (TGF)‐β/BMP superfamily, and we have demonstrated that it is one of the most potent BMPs to induce osteoblast differentiation of mesenchymal stem cells (MSCs). Here, we sought to investigate if canonical Wnt/β‐catenin signalling plays an important role in BMP‐9‐induced osteogenic differentiation of MSCs. Wnt3A and BMP‐9 enhanced each other’s ability to induce alkaline phosphatase (ALP) in MSCs and mouse embryonic fibroblasts (MEFs). Wnt antagonist FrzB was shown to inhibit BMP‐9‐induced ALP activity more effectively than Dkk1, whereas a secreted form of LPR‐5 or low‐density lipoprotein receptor‐related protein (LRP)‐6 exerted no inhibitory effect on BMP‐9‐induced ALP activity. β‐Catenin knockdown in MSCs and MEFs diminished BMP‐9‐induced ALP activity, and led to a decrease in BMP‐9‐induced osteocalcin reporter activity and BMP‐9‐induced expression of late osteogenic markers. Furthermore, β‐catenin knockdown or FrzB overexpression inhibited BMP‐9‐induced mineralization in vitro and ectopic bone formation in vivo, resulting in immature osteogenesis and the formation of chondrogenic matrix. Chromatin immunoprecipitation (ChIP) analysis indicated that BMP‐9 induced recruitment of both Runx2 and β‐catenin to the osteocalcin promoter. Thus, we have demonstrated that canonical Wnt signalling, possibly through interactions between β‐catenin and Runx2, plays an important role in BMP‐9‐induced osteogenic differentiation of MSCs. PMID:19175684

  6. Sonic Hedgehog Activation Is Implicated in Diosgenin-Induced Megakaryocytic Differentiation of Human Erythroleukemia Cells

    PubMed Central

    Ghezali, Lamia; Liagre, Bertrand; Limami, Youness; Beneytout, Jean-Louis; Leger, David Yannick

    2014-01-01

    Differentiation therapy is a means to treat cancer and is induced by different agents with low toxicity and more specificity than traditional ones. Diosgenin, a plant steroid, is able to induce megakaryocytic differentiation or apoptosis in human HEL erythroleukemia cells in a dose-dependent manner. However, the exact mechanism by which diosgenin induces megakaryocytic differentiation has not been elucidated. In this study, we studied the involvement of Sonic Hedgehog in megakaryocytic differentiation induced by diosgenin in HEL cells. First, we showed that different elements of the Hedgehog pathway are expressed in our model by qRT-PCR. Then, we focused our interest on key elements in the Sonic Hedgehog pathway: Smoothened receptor, GLI transcription factor and the ligand Sonic Hedgehog. We showed that Smoothened and Sonic Hedgehog were overexpressed in disogenin-treated cells and that GLI transcription factors were activated. Then, we showed that SMO inhibition using siSMO or the GLI antagonist GANT-61, blocked megakaryocytic differentiation induced by diosgenin in HEL cells. Furthermore, we demonstrated that Sonic Hedgehog pathway inhibition led to inhibition of ERK1/2 activation, a major physiological pathway involved in megakaryocytic differentiation. In conclusion, our study reports, for the first time, a crucial role for the Sonic Hedgehog pathway in diosgenin-induced megakaryocytic differentiation in HEL cells. PMID:24740159

  7. Sonic Hedgehog activation is implicated in diosgenin-induced megakaryocytic differentiation of human erythroleukemia cells.

    PubMed

    Ghezali, Lamia; Liagre, Bertrand; Limami, Youness; Beneytout, Jean-Louis; Leger, David Yannick

    2014-01-01

    Differentiation therapy is a means to treat cancer and is induced by different agents with low toxicity and more specificity than traditional ones. Diosgenin, a plant steroid, is able to induce megakaryocytic differentiation or apoptosis in human HEL erythroleukemia cells in a dose-dependent manner. However, the exact mechanism by which diosgenin induces megakaryocytic differentiation has not been elucidated. In this study, we studied the involvement of Sonic Hedgehog in megakaryocytic differentiation induced by diosgenin in HEL cells. First, we showed that different elements of the Hedgehog pathway are expressed in our model by qRT-PCR. Then, we focused our interest on key elements in the Sonic Hedgehog pathway: Smoothened receptor, GLI transcription factor and the ligand Sonic Hedgehog. We showed that Smoothened and Sonic Hedgehog were overexpressed in disogenin-treated cells and that GLI transcription factors were activated. Then, we showed that SMO inhibition using siSMO or the GLI antagonist GANT-61, blocked megakaryocytic differentiation induced by diosgenin in HEL cells. Furthermore, we demonstrated that Sonic Hedgehog pathway inhibition led to inhibition of ERK1/2 activation, a major physiological pathway involved in megakaryocytic differentiation. In conclusion, our study reports, for the first time, a crucial role for the Sonic Hedgehog pathway in diosgenin-induced megakaryocytic differentiation in HEL cells.

  8. Differential susceptibility of naive and differentiated PC-12 cells to methylglyoxal-induced apoptosis: influence of cellular redox.

    PubMed

    Okouchi, Masahiro; Okayama, Naotsuka; Aw, Tak Yee

    2005-01-01

    Neuropathologies have been associated with neuronal de-differentiation and oxidative susceptibility. To address whether cellular states determines their oxidative vulnerability, we have challenged naive (undifferentiated) and nerve growth factor-induced differentiated pheochromocytoma (PC12) with methylglyoxal (MG), a model of carbonyl stress. MG dose-dependently induced greater apoptosis (24 h) in naive (nPC12) than differentiated (dPC12) cells. This enhanced nPC12 susceptibility was correlated with a high basal oxidized cellular glutathione-to-glutathione disulfide (GSH/GSSG) redox and an MG-induced GSH-to-Disulfide (GSSG plus protein-bound SSG) imbalance. The loss of redox balance occurred at 30 min post-MG exposure, and was prevented by N-acetylcysteine (NAC) that was unrelated to de novo GSH synthesis. NAC was ineffective when added at 1h post-MG, consistent with an early window of redox signaling. This redox shift was kinetically linked to decreased BcL-2, increased Bax, and release of mitochondrial cytochrome c which preceded caspase-9 and -3 activation and poly ADP-ribose polymerase (PARP) cleavage (1-2 h), consistent with mitochondrial apoptotic signaling. The blockade of apoptosis by cyclosporine A supported an involvement of the mitochondrial permeability transition pore. The enhanced vulnerability of nPC12 cells to MG and its relationship to cellular redox shifts will have important implications for understanding differential oxidative vulnerability in various cell types and their transition states.

  9. Creating an Animal Model of Tendinopathy by Inducing Chondrogenic Differentiation with Kartogenin.

    PubMed

    Yuan, Ting; Zhang, Jianying; Zhao, Guangyi; Zhou, Yiqin; Zhang, Chang-Qing; Wang, James H-C

    2016-01-01

    Previous animal studies have shown that long term rat treadmill running induces over-use tendinopathy, which manifests as proteoglycan accumulation and chondrocytes-like cells within the affected tendons. Creating this animal model of tendinopathy by long term treadmill running is however time-consuming, costly and may vary among animals. In this study, we used a new approach to develop an animal model of tendinopathy using kartogenin (KGN), a bio-compound that can stimulate endogenous stem/progenitor cells to differentiate into chondrocytes. KGN-beads were fabricated and implanted into rat Achilles tendons. Five weeks after implantation, chondrocytes and proteoglycan accumulation were found at the KGN implanted site. Vascularity as well as disorganization in collagen fibers were also present in the same site along with increased expression of the chondrocyte specific marker, collagen type II (Col. II). In vitro studies confirmed that KGN was released continuously from KGN-alginate in vivo beads and induced chondrogenic differentiation of tendon stem/progenitor cells (TSCs) suggesting that chondrogenesis after KGN-bead implantation into the rat tendons is likely due to the aberrant differentiation of TSCs into chondrocytes. Taken together, our results showed that KGN-alginate beads can be used to create a rat model of tendinopathy, which, at least in part, reproduces the features of over-use tendinopathy model created by long term treadmill running. This model is mechanistic (stem cell differentiation), highly reproducible and precise in creating localized tendinopathic lesions. It is expected that this model will be useful to evaluate the effects of various topical treatments such as NSAIDs and platelet-rich plasma (PRP) for the treatment of tendinopathy.

  10. EFFECTS OF TOXICANTS ON NEURAL DIFFERENTIATION

    EPA Science Inventory

    This manuscript describes in vitro measures of neural differentiation. This overview provides the background and literature review for measures that could be employed in both screening assays and mechanistic studies. this chapter also reviews data from key endpoints like neurite ...

  11. Electrical Stimulation Promotes Cardiac Differentiation of Human Induced Pluripotent Stem Cells

    PubMed Central

    Hernández, Damián; Millard, Rodney; Sivakumaran, Priyadharshini; Wong, Raymond C. B.; Crombie, Duncan E.; Hewitt, Alex W.; Liang, Helena; Hung, Sandy S. C.; Pébay, Alice; Shepherd, Robert K.; Dusting, Gregory J.; Lim, Shiang Y.

    2016-01-01

    Background. Human induced pluripotent stem cells (iPSCs) are an attractive source of cardiomyocytes for cardiac repair and regeneration. In this study, we aim to determine whether acute electrical stimulation of human iPSCs can promote their differentiation to cardiomyocytes. Methods. Human iPSCs were differentiated to cardiac cells by forming embryoid bodies (EBs) for 5 days. EBs were then subjected to brief electrical stimulation and plated down for 14 days. Results. In iPS(Foreskin)-2 cell line, brief electrical stimulation at 65 mV/mm or 200 mV/mm for 5 min significantly increased the percentage of beating EBs present by day 14 after plating. Acute electrical stimulation also significantly increased the cardiac gene expression of ACTC1, TNNT2, MYH7, and MYL7. However, the cardiogenic effect of electrical stimulation was not reproducible in another iPS cell line, CERA007c6. Beating EBs from control and electrically stimulated groups expressed various cardiac-specific transcription factors and contractile muscle markers. Beating EBs were also shown to cycle calcium and were responsive to the chronotropic agents, isoproterenol and carbamylcholine, in a concentration-dependent manner. Conclusions. Our results demonstrate that brief electrical stimulation can promote cardiac differentiation of human iPS cells. The cardiogenic effect of brief electrical stimulation is dependent on the cell line used. PMID:26788064

  12. Porcine tooth germ cell conditioned medium can induce odontogenic differentiation of human dental pulp stem cells.

    PubMed

    Wang, Yin-Xiong; Ma, Zhao-Feng; Huo, Na; Tang, Liang; Han, Chun; Duan, Yin-Zhong; Jin, Yan

    2011-05-01

    It is suggested that the differentiation of tooth-derived stem cells is modulated by the local microenvironment in which they reside. Previous studies have indicated that tooth germ cell-conditioned medium (TGC-CM) holds the potential to induce dental pulp stem cells (DPSCs) to differentiate into the odontogenic lineage. Nevertheless, human TGC-CM (hTGC-CM) is not feasible in practical application, so we conjectured that xenogenic TGC-CM might exert a similar influence on human dental stem cells. In this study, we chose swine as the xenogenic origin and compared the effect of porcine tooth germ cell-conditioned medium (pTGC-CM) with its human counterpart on human DPSCs. Morphological appearance, colony-forming assay, in vitro multipotential ability, protein and gene expression of the odontogenic phenotype and the in vivo differentiation capacity of DPSCs were evaluated. The results showed that pTGC-CM exerted a similar effect to hTGC-CM in inducing human DPSCs to present odontogenic changes, which were indicated by remarkable morphological changes, higher multipotential capability and the expression of some odontogenic markers in gene and protein levels. Besides, the in vivo results showed that pTGC-CM-treated DPSCs, similar to hTGC-CM-treated DPSCs, could form a more regular dentine-pulp complex. Our data provided the first evidence that pTGC-CM is able to exert almost the same effect on DPSCs with hTGC-CM. The observations suggest that the application of xenogenic TGC-CM may facilitate generating bioengineered teeth from tooth-derived stem cells in future.

  13. Myogenic differentiation induces taurine transporter in association with taurine-mediated cytoprotection in skeletal muscles.

    PubMed

    Uozumi, Yoriko; Ito, Takashi; Hoshino, Yuki; Mohri, Tomomi; Maeda, Makiko; Takahashi, Kyoko; Fujio, Yasushi; Azuma, Junichi

    2006-03-15

    Skeletal muscle homoeostasis is maintained by a variety of cytoprotective mechanisms. Since ablation of the TauT (taurine transporter) gene results in susceptibility to exercise-induced muscle weakness in vivo, it has been suggested that TauT is essential for skeletal muscle function. However, the regulatory mechanisms of TauT expression remain to be elucidated. In the present study, we demonstrated that TauT was up-regulated during myogenesis in C2C12 cells. Treatment with bFGF (basic fibroblast growth factor), which inhibited muscle differentiation, abrogated myogenic induction of TauT. The promoter activities of TauT were up-regulated during muscle differentiation in C2C12 cells. Database analyses identified an MEF2 (myocyte enhancer binding factor 2) consensus sequence at -844 in the rat TauT gene. Truncation of the promoter region containing the MEF2 site significantly reduced the promoter activity, demonstrating the functional importance of the MEF2 site. Electrophoretic mobility-shift assays confirmed that MEF2 bound to the MEF2 consensus sequence and that DNA-protein complex levels were increased during differentiation. Promoter analyses using mutated promoter-reporter plasmids demonstrated that this site was functional. Importantly, transfection with a MyoD expression vector markedly enhanced TauT promoter activity in the (non-myogenic) 10T1/2 cells. Moreover, co-transfection with an MEF2 expression vector augmented MyoD-induced TauT promoter activity, suggesting that MEF2 is required for full activation of TauT expression. Finally, we examined the effects of taurine on myotube atrophy to clarify the biological significance of the up-regulation of TauT, and demonstrated that taurine attenuated muscle atrophy induced by dexamethasone. TauT expression is regulated under the control of the myogenic programme, and we propose that this is the mechanism for taurine-mediated resistance to muscle atrophy.

  14. The endocrine disruptor diethylstilbestrol induces adipocyte differentiation and promotes obesity in mice

    SciTech Connect

    Hao, Chan-Juan; Cheng, Xue-Jia; Xia, Hong-Fei Ma, Xu

    2012-08-15

    Epidemiology studies indicate that exposure to endocrine disruptors during developmental “window” contributes to adipogenesis and the development of obesity. Implication of endocrine disruptor such as diethylstilbestrol (DES) on adipose tissue development has been poorly investigated. Here we evaluated the effects of DES on adipocyte differentiation in vitro and in vivo, and explored potential mechanism involved in its action. DES induced 3T3-L1 preadipocyte differentiation in a dose-dependent manner, and activated the expression of estrogen receptor (ER) and peroxisome proliferator-acivated receptor (PPAR) γ as well as its target genes required for adipogenesis in vitro. ER mediated the enhancement of DES-induced PPARγ activity. Moreover, DES perturbed key regulators of adipogenesis and lipogenic pathway in vivo. In utero exposure to low dose of DES significantly increased body weight, liver weight and fat mass in female offspring at postnatal day (PND) 60. In addition, serum triglyceride and glucose levels were also significantly elevated. These results suggest that perinatal exposure to DES may be expected to increase the incidence of obesity in a sex-dependent manner and can act as a potential chemical stressor for obesity and obesity-related disorders. -- Highlights: ► DES induced adipocyte differentiation in a dose-dependent manner in 3T3-L1 cells. ► DES activated adipogenic critical regulators and markers in vitro and in vivo. ► Perinatal exposure to DES led to the obese phenotype in female offspring. ► DES might be a potential chemical stressor for obesity and obesity-related disorders.

  15. Total saponins of Panax ginseng induces K562 cell differentiation by promoting internalization of the erythropoietin receptor.

    PubMed

    Zuo, Guowei; Guan, Tao; Chen, Dilong; Li, Chunli; Jiang, Rong; Luo, Chunyan; Hu, Xiaoshu; Wang, Yaping; Wang, Jianwei

    2009-01-01

    Ginseng is a commonly used herbal medicine with a wide range of therapeutic benefits. Total saponins of Panax ginseng (TSPG) is one of the main effective components of ginseng. Our previous studies have shown that TSPG could promote the production of normal blood cells and inhibition of the leukemia cell proliferation. However, whether ginseng can induce the differentiation of leukemia cells is still unclear. This study was to examine the effect of TSPG or the combination of erythropoietin (EPO) and TSPG on the erythroid differentiation of K562 cells, and their corresponding mechanisms regarding erythropoietin receptor (EPOR) expression. Under light and electron microscopes, the TSPG- or TSPG + EPO-treated K562 cells showed a tendency to undergo erythroid differentiation; early and intermediate erythroblast-like cells were observed. Hemoglobin and HIR2 expressions were significantly increased. As determined by Western blotting analysis, the EPOR protein level in the K562 cytoplasmic membrane was significantly decreased after TSPG treatment, while its cytoplasm level increased in a dose-dependent manner. However, the total cellular EPOR level was unchanged. These results indicate that TSPG-induced erythroid differentiation of K562 cells may be accompanied by the internalization of EPOR. Thus, our study suggests that treatment with a combination of TSPG and EPO may induce erythroid differentiation of K562 cells at least in part through induction of EPOR internalization.

  16. Differential effect of visual motion adaption upon visual cortical excitability.

    PubMed

    Lubeck, Astrid J A; Van Ombergen, Angelique; Ahmad, Hena; Bos, Jelte E; Wuyts, Floris L; Bronstein, Adolfo M; Arshad, Qadeer

    2017-03-01

    The objectives of this study were 1) to probe the effects of visual motion adaptation on early visual and V5/MT cortical excitability and 2) to investigate whether changes in cortical excitability following visual motion adaptation are related to the degree of visual dependency, i.e., an overreliance on visual cues compared with vestibular or proprioceptive cues. Participants were exposed to a roll motion visual stimulus before, during, and after visual motion adaptation. At these stages, 20 transcranial magnetic stimulation (TMS) pulses at phosphene threshold values were applied over early visual and V5/MT cortical areas from which the probability of eliciting a phosphene was calculated. Before and after adaptation, participants aligned the subjective visual vertical in front of the roll motion stimulus as a marker of visual dependency. During adaptation, early visual cortex excitability decreased whereas V5/MT excitability increased. After adaptation, both early visual and V5/MT excitability were increased. The roll motion-induced tilt of the subjective visual vertical (visual dependence) was not influenced by visual motion adaptation and did not correlate with phosphene threshold or visual cortex excitability. We conclude that early visual and V5/MT cortical excitability is differentially affected by visual motion adaptation. Furthermore, excitability in the early or late visual cortex is not associated with an increase in visual reliance during spatial orientation. Our findings complement earlier studies that have probed visual cortical excitability following motion adaptation and highlight the differential role of the early visual cortex and V5/MT in visual motion processing.NEW & NOTEWORTHY We examined the influence of visual motion adaptation on visual cortex excitability and found a differential effect in V1/V2 compared with V5/MT. Changes in visual excitability following motion adaptation were not related to the degree of an individual's visual dependency.

  17. Breast Cancer Prevention by Fatty Acid Binding Protein MRG-Induced Pregnancy Like Mammary Gland Differentiation

    DTIC Science & Technology

    2005-08-01

    Annual Summary 3. DATES COVERED (From - To) 1 AUG 2004 - 31 JUL 2005 4. TITLE AND SUBTITLE Breast Cancer Prevention by Fatty Acid Binding Protein...differentiation. Overexpression of MRG in human breast cancer cells induced differentiation with changes in cellular morphology and a significant increase

  18. Beta-mecaptoethanol suppresses inflammation and induces adipogenic differentiation in 3T3-F442A murine preadipocytes.

    PubMed

    Guo, Wen; Li, Yahui; Liang, Wentao; Wong, Siu; Apovian, Caroline; Kirkland, James L; Corkey, Barbara E

    2012-01-01

    Preadipocytes are present in adipose tissues throughout adult life that can proliferate and differentiate into mature adipocytes in response to environmental cues. Abnormal increase in adipocyte number or size leads to fat tissue expansion. However, it is now recognized that adipocyte hypertrophy is a greater risk factor for metabolic syndrome whereas fat tissue that continues to produce newer and smaller fat cells through preadipocyte differentiation is "metabolically healthy". Because adipocyte hypertrophy is often associated with increased oxidant stress and low grade inflammation, both are linked to disturbed cellular redox, we tested how preadipocyte differentiation may be regulated by beta-mercaptoethanol (BME), a pharmacological redox regulator and radical scavenger, using murine 3T3-F442A preadipocytes as the cell model. Effects of BME on adipogenesis were measured by microphotography, real-time PCR, and Western analysis. Our data demonstrated that preadipocyte differentiation could be regulated by extracellular BME. At an optimal concentration, BME enhanced expression of adipogenic gene markers and lipid accumulation. This effect was associated with BME-mediated down-regulation of inflammatory cytokine expression during early differentiation. BME also attenuated TNFalpha-induced activation of NFkappaB in differentiating preadipocytes and partially restored TNFalpha-mediated suppression on adipogenesis. Using a non-adipogenic HEK293 cell line transfected with luciferase reporter genes, we demonstrated that BME reduced basal and TNFalpha-induced NFkappaB activity and increased basal and ciglitazone-induced PPARgamma activity; both may contribute to the pro-adipogenic effect of BME in differentiating F442A preadipocytes.

  19. Different effect of prostaglandin E2 on B-cell activation by two distinct B-cell differentiation factors, B151-TRF1/IL-5 and B151-TRF2: selective inhibition of B151-TRF2-induced antibody response through increases in intracellular cyclic AMP levels

    PubMed Central

    Ishihara, K.; Ono, S.; Takahama, Y.; Hirayama, F.; Hirano, H.; Itoh, K.; Dobashi, K.; Murakami, S.; Katoh, Y.; Yamaguchi, M.; Hamaoka, T.

    1989-01-01

    Effects of prostaglandin E2 (PGE2) on murine B-cell activation induced by two distinct B-cell differentiation factors, B151-TRF1/IL-5 and B151-TRF2, were examined. A final differentiation of unprimed B cells into IgM-producing cells induced by B151-TRF2 was markedly inhibited by PGE2 at physiological concentrations (around 10-8 M), whereas B151-TRF1/IL-5-induced antibody responses of unprimed as well as activated B cells were not affected by PGE2, even at 10-6 M. B-cell responses induced by B151-TRF2-like factors from autoimmune-prone MRL/1pr mice were also inhibited by PGE2. Biphasic increases in intracellular cyclic AMP (cAMP) levels were induced by culturing B cells with 10-6 or 10-8 M PGE2: rapid increases within 8 min and delayed increases around 16 hr. The direct addition of dibutyryl cAMP to cultures of B cells resulted in marked inhibition of antibody responses when stimulated with B151-TRF2 but not with B151-TRF1/IL-5. The B151-TRF2-induced antibody responses were also inhibited by cAMP-elevating reagents such as forskolin, cholera toxin and theophyline. Furthermore, 2′, 5′-dideoxyadenosine, which is an inhibitor of adenylate cyclase, prevented the PGE2-mediated cAMP accumulation in unprimed B cells as well as the PGE2-mediated inhibition of B151-TRF2-induced B-cell responses when added at the initiation of culture. These results suggest that PGE2 inhibits B151-TRF2-induced antibody responses through the activation of adenylate cyclase and subsequent accumulation of intracellular cAMP, whereas B151-TRF1/IL-5-responsive B cells are resistant to the inhibitory effect of PGE2 and cAMP. PMID:2553585

  20. Graphene induces spontaneous cardiac differentiation in embryoid bodies

    NASA Astrophysics Data System (ADS)

    Ahadian, Samad; Zhou, Yuanshu; Yamada, Shukuyo; Estili, Mehdi; Liang, Xiaobin; Nakajima, Ken; Shiku, Hitoshi; Matsue, Tomokazu

    2016-03-01

    Graphene was embedded into the structure of mouse embryoid bodies (EBs) using the hanging drop technique. The inclusion of 0.2 mg per mL graphene in the EBs did not affect the viability of the stem cells. However, the graphene decreased the stem cell proliferation, probably by accelerating cell differentiation. The graphene also enhanced the mechanical properties and electrical conductivity of the EBs. Interestingly, the cardiac differentiation of the EB-graphene was significantly greater than that of the EBs at day 5 of culture, as confirmed by high-throughput gene analysis. Electrical stimulation (voltage, 4 V; frequency, 1 Hz; and duration, 10 ms for 2 continuous days) further enhanced the cardiac differentiation of the EBs, as demonstrated by analyses of the cardiac protein and gene expression and the beating activity of the EBs. Taken together, the results demonstrated that graphene played a major role in directing the cardiac differentiation of EBs, which has potential cell therapy and tissue regeneration applications.Graphene was embedded into the structure of mouse embryoid bodies (EBs) using the hanging drop technique. The inclusion of 0.2 mg per mL graphene in the EBs did not affect the viability of the stem cells. However, the graphene decreased the stem cell proliferation, probably by accelerating cell differentiation. The graphene also enhanced the mechanical properties and electrical conductivity of the EBs. Interestingly, the cardiac differentiation of the EB-graphene was significantly greater than that of the EBs at day 5 of culture, as confirmed by high-throughput gene analysis. Electrical stimulation (voltage, 4 V; frequency, 1 Hz; and duration, 10 ms for 2 continuous days) further enhanced the cardiac differentiation of the EBs, as demonstrated by analyses of the cardiac protein and gene expression and the beating activity of the EBs. Taken together, the results demonstrated that graphene played a major role in directing the cardiac

  1. Evaluating Differential Effects Using Regression Interactions and Regression Mixture Models

    ERIC Educational Resources Information Center

    Van Horn, M. Lee; Jaki, Thomas; Masyn, Katherine; Howe, George; Feaster, Daniel J.; Lamont, Andrea E.; George, Melissa R. W.; Kim, Minjung

    2015-01-01

    Research increasingly emphasizes understanding differential effects. This article focuses on understanding regression mixture models, which are relatively new statistical methods for assessing differential effects by comparing results to using an interactive term in linear regression. The research questions which each model answers, their…

  2. [Differentiation of human promyelocytic leukemia HL-60 cells induced by proanthocyanidin and its mechanism].

    PubMed

    Xie, Zhao-Yang; Wu, Bin-Hua; Yang, Zhi-Gang; Chen, Xiao-Fang; Chen, Qiu-Shen

    2013-08-01

    This study was purposed to investigate the proliferation, differentiation and apoptosis of human promyelocytic leukemia HL-60 cells induced by proanthocyanidin (PAC). HL-60 cells were incubated with 20 mg/L PAC for 24 h, the cell growth was evaluated by CCK-8 assay. the effect of PAC on HL-60 cells was evaluated and the cells morphology was observed by optical microscopy. Expression of CD14 and CD11b, and cell cycle were analyzed by flow cytometry. The results showed that the growth of HL-60 cells was inhibited after treatment with PAC of different concentration in a dose-dependent manner (P < 0.05). 20 mg/L PAC displayed significant effect on HL-60 cells with inhibition ratio (72.3 ± 1.8)% for 24 h. Microscopy displayed that some cells differentiated to relative mature cells after treating for 48 h. Expression of CD14 increased and the expression of CD11b increased a little after treating with 20 mg/L PAC for 24 h, the ratio of cells in G0/G1 phase increased, but the ratio of cells in S phase decreased. The mRNA and protein expression of P21 gene increased, but the protein expression of CDK4 and Cyclin D1 decreased. It is concluded that PAC may inhibit the proliferation of HL-60 cells in vitro, induces the differentiation of HL-60 cells, and arrests the cells in G0/G1 phase. The possible mechanism may be related to up-regulation of P21 gene expression and down-regulation of the protein expression of CDK4 and Cyclin D1.

  3. Inhibitory effect of simulated microgravity on differentiating preosteoblasts

    NASA Astrophysics Data System (ADS)

    Hu, L. F.; Qian, A. R.; Wang, Y.; Di, S. M.; Shang, P.

    2013-01-01

    The bone loss induced by microgravity is partly due to the decrease of mature osteoblasts. In the present study, we employed the random positioning machine (RPM) to simulate microgravity and investigated the acute effects of simulated microgravity on the differentiation of 2T3 preosteoblasts. Following 7 days' culture under normal (1 g) condition, cells were exposed to simulated microgravity for 24 h. The results showed that 24 h treatment of simulated microgravity significantly decreased alkaline phosphatase (ALP) activity without changing the cell morphology. In addition, the mRNA expressions of osteogenic genes, including runt-related gene 2 (Runx2), osterix, osteocalcin (OC), type I collagen (Col I) and bone morphogenetic protein (BMP), were dramatically downregulated. Moreover, western blot analysis of total extracellular signal-regulated kinase (Erk) and phosphorylated Erk (p-Erk) indicated that p-Erk level, which represents the Erk activation status, was increased. Taken together, our results suggested that acute exposure to simulated microgravity inhibited osteoblast differentiation through modulating the expression of osteogenic genes and the Erk activity. These findings provide new insight for bone loss due to microgravity and unloading.

  4. Pycnogenol induces differentiation and apoptosis in human promyeloid leukemia HL-60 cells.

    PubMed

    Huang, W W; Yang, J S; Lin, C F; Ho, W J; Lee, M R

    2005-06-01

    Pycnogenol, rich of many phytochemicals of medical value, is a commercialized nutrient supplement extracted from the bark of European coastal pine. In this study, we investigated the anti-tumor effects of Pycnogenol on HL-60, U937 and K562 human leukemia cell lines. We found that Pycnogenol inhibited cell proliferation dose- and time-dependently, and the IC(50)s of Pycnogenol on HL-60, U937 and K562 cells were 150, 40 and 100 microg/ml, respectively. When HL-60 cells were incubated with low concentrations of Pycnogenol (50, 100 and 125 microg/ml) for 24 h, a prominent G0/G1 arrest was observed, followed by gradual accumulation of sub-G0/G1 nuclei. At 48 h of treatment, 50-70% of HL-60 cells differentiated, as evidenced by morphological changes, NBT reduction, induction of NSE activity, and increases of cell surface expression of CD11b. However, results from Annexin V/PI staining, DAPI staining and DNA fragmentation assay indicated that Pycnogenol induced HL-60, U937 and K562 cell apoptosis at their respective IC(50)s after 24 h of treatments. Pretreatment of z-DEVD-fmk, a caspase-3 specific inhibitor, not only decreased caspase-3 activity but also reduced the percentage of apoptotic cells induced by Pycnogenol. This indicated that caspase-3 activation was involved in Pycnogenol induced-apoptosis. In conclusion, Pycnogenol induced differentiation and apoptosis in leukemia cells. Our data suggest that Pycnogenol could serve as a potent cancer chemopreventive or chemotherapeutic agent for human leukemia.

  5. Differential outcome of TRIF-mediated signaling in TLR4 and TLR3 induced DC maturation.

    PubMed

    Hu, Wei; Jain, Aakanksha; Gao, Yajing; Dozmorov, Igor M; Mandraju, Rajakumar; Wakeland, Edward K; Pasare, Chandrashekhar

    2015-11-10

    Recognition of pathogen-associated molecular patterns by Toll-like receptors (TLRs) on dendritic cells (DCs) leads to DC maturation, a process involving up-regulation of MHC and costimulatory molecules and secretion of proinflammatory cytokines. All TLRs except TLR3 achieve these outcomes by using the signaling adaptor myeloid differentiation factor 88. TLR4 and TLR3 can both use the Toll-IL-1 receptor domain-containing adaptor inducing IFN-β (TRIF)-dependent signaling pathway leading to IFN regulatory factor 3 (IRF3) activation and induction of IFN-β and -α4. The TRIF signaling pathway, downstream of both of these TLRs, also leads to DC maturation, and it has been proposed that the type I IFNs act in cis to induce DC maturation and subsequent effects on adaptive immunity. The present study was designed to understand the molecular mechanisms of TRIF-mediated DC maturation. We have discovered that TLR4-TRIF-induced DC maturation was independent of both IRF3 and type I IFNs. In contrast, TLR3-mediated DC maturation was completely dependent on type I IFN feedback. We found that differential activation of mitogen-activated protein kinases by the TLR4- and TLR3-TRIF axes determined the type I IFN dependency for DC maturation. In addition, we found that the adjuvanticity of LPS to induce T-cell activation is completely independent of type I IFNs. The important distinction between the TRIF-mediated signaling pathways of TLR4 and TLR3 discovered here could have a major impact in the design of future adjuvants that target this pathway.

  6. Dimethyl fumarate–induced lymphopenia in MS due to differential T-cell subset apoptosis

    PubMed Central

    Ghadiri, Mahtab; Rezk, Ayman; Li, Rui; Evans, Ashley; Luessi, Felix; Zipp, Frauke; Giacomini, Paul S.; Antel, Jack

    2017-01-01

    Objective: To examine the mechanism underlying the preferential CD8+ vs CD4+ T-cell lymphopenia induced by dimethyl fumarate (DMF) treatment of MS. Methods: Total lymphocyte counts and comprehensive T-cell subset analyses were performed in high-quality samples obtained from patients with MS prior to and serially following DMF treatment initiation. Random coefficient mixed-effects analysis was used to model the trajectory of T-cell subset losses in vivo. Survival and apoptosis of distinct T-cell subsets were assessed following in vitro exposure to DMF. Results: Best-fit modeling indicated that the DMF-induced preferential reductions in CD8+ vs CD4+ T-cell counts nonetheless followed similar depletion kinetics, suggesting a similar rather than distinct mechanism involved in losses of both the CD8+ and CD4+ T cells. In vitro, DMF exposure resulted in dose-dependent reductions in T-cell survival, which were found to reflect apoptotic cell death. This DMF-induced apoptosis was greater for CD8+ vs CD4+, as well as for memory vs naive, and conventional vs regulatory T-cell subsets, a pattern which mirrored preferential T-cell subset losses that we observed during in vivo treatment of patients. Conclusions: Differential apoptosis mediated by DMF may underlie the preferential lymphopenia of distinct T-cell subsets, including CD8+ and memory T-cell subsets, seen in treated patients with MS. This differential susceptibility of distinct T-cell subsets to DMF-induced apoptosis may contribute to both the safety and efficacy profiles of DMF in patients with MS. PMID:28377940

  7. Graphene induces spontaneous cardiac differentiation in embryoid bodies.

    PubMed

    Ahadian, Samad; Zhou, Yuanshu; Yamada, Shukuyo; Estili, Mehdi; Liang, Xiaobin; Nakajima, Ken; Shiku, Hitoshi; Matsue, Tomokazu

    2016-04-07

    Graphene was embedded into the structure of mouse embryoid bodies (EBs) using the hanging drop technique. The inclusion of 0.2 mg per mL graphene in the EBs did not affect the viability of the stem cells. However, the graphene decreased the stem cell proliferation, probably by accelerating cell differentiation. The graphene also enhanced the mechanical properties and electrical conductivity of the EBs. Interestingly, the cardiac differentiation of the EB-graphene was significantly greater than that of the EBs at day 5 of culture, as confirmed by high-throughput gene analysis. Electrical stimulation (voltage, 4 V; frequency, 1 Hz; and duration, 10 ms for 2 continuous days) further enhanced the cardiac differentiation of the EBs, as demonstrated by analyses of the cardiac protein and gene expression and the beating activity of the EBs. Taken together, the results demonstrated that graphene played a major role in directing the cardiac differentiation of EBs, which has potential cell therapy and tissue regeneration applications.

  8. Exogenous Gas6 attenuates silica-induced inflammation on differentiated THP-1 macrophages.

    PubMed

    Shen, Yan; Cui, Xiuqing; Rong, Yi; Zhang, Zhihong; Xiao, Lili; Zhou, Ting; Chen, Weihong

    2016-07-01

    Growth arrest specific 6 (Gas6) has been reported to be related to the modulation of innate immunity. To investigate the potential effect of Gas6 on the regulation of inflammations induced by silica, differentiated THP-1 macrophages were exposed to different concentrations of silica for 6h and 24h. Additionally, silica-activated macrophages were treated with Gas6 antibody and Gas6 respectively. Expression levels of Gas6 and inflammatory cytokines (TNF-α, IL-1β and IL-6) were measured. Our results showed that both cell viability and Gas6 expression were suppressed by silica in dose-dependent manners. After pretreatment with Gas6 antibody, silica induced a significant decrease in cell viability and a significant increase in inflammatory cytokines at two time points. Moreover, addition of Gas6 significantly suppressed silica induced TNF-α, IL-1β and IL-6 levels in negative dose-dependent manners, not only in mRNA levels but also in protein levels. Our results suggested that exogenous Gas6 might attenuate inflammations induced by silica on macrophages.

  9. Exocrine pancreas ER stress is differentially induced by different fatty acids.

    PubMed

    Danino, Hila; Ben-Dror, Karin; Birk, Ruth

    2015-12-10

    Exocrine pancreas acinar cells have a highly developed endoplasmic reticulum (ER), accommodating their high protein production rate. Overload of dietary fat (typical to obesity) is a recognized risk factor in pancreatitis and pancreatic cancer. Dietary fat, especially saturated fat, has been suggested by others and us to induce an acinar lipotoxic effect. The effect of different dietary fatty acids on the ER stress response is unknown. We studied the effect of acute (24h) challenge with different fatty acids (saturated, mono and poly-unsaturated) at different concentrations (between 200 and 500µM, typical to normal and obese states, respectively), testing fat accumulation, ER stress indicators, X-box binding protein 1 (Xbp1) splicing and nuclear translocation, as well as unfolded protein response (UPR) transcripts and protein levels using exocrine pancreas acinar AR42J and primary cells. Acute exposure of AR42J cells to different fatty acids caused increased accumulation of triglycerides, dependent on the type of fat. Different FAs had different effects on ER stress: most notably, saturated palmitic acid significantly affected the UPR response, as demonstrated by altered Xbp1 splicing, elevation in transcript levels of UPR (Xbp, CHOP, Bip) and immune factors (Tnfα, Tgfβ), and enhanced Xbp1 protein levels and Xbp1 time-dependent nuclear translocation. Poly-unsaturated FAs caused milder elevation of ER stress markers, while mono-unsaturated oleic acid attenuated the ER stress response. Thus, various fatty acids differentially affect acinar cell fat accumulation and, apart from oleic acid, induce ER stress. The differential effect of the various fatty acids could have potential nutritional and therapeutic implications.

  10. Isolation of furocoumarins from bergamot fruits as HL-60 differentiation-inducing compounds.

    PubMed

    Kawaii, S; Tomono, Y; Katase, E; Ogawa, K; Yano, M

    1999-10-01

    The HL-60 differentiation-inducing compounds in bergamot fruits were isolated with column chromatography and identified as bergamottin, bergapten, and citropten by (1)H and (13)C NMR. Their HL-60 differentiation-inducing activity was measured by examining nitro blue tetrazolium (NBT) reducing, nonspecific acid esterase (NSE), specific esterase (SE), and phagocytic activities, and bergamottin showed the strongest activity among the coumarins isolated from bergamot fruits. The structure-activity relationship obtained from HL-60 differentiation assay suggests that hydrophobicity of furocoumarins is correlated with their activity.

  11. Differentiation-inducing activity of lupeol, a lupane-type triterpene from Chinese dandelion root (Hokouei-kon), on a mouse melanoma cell line.

    PubMed

    Hata, K; Ishikawa, K; Hori, K; Konishi, T

    2000-08-01

    We examined the differentiation-inducing effects of extracts of 49 wild plants, 25 types of seaweed and 26 mushrooms in Akita on the human leukemia cell line HL60 and a B16 mouse melanoma-derived sub-clone with high differentiation capability (B16 2F2). Differentiation inducers of HL60 cells such as retinoic acid, showed no effects on the differentiation of B16 2F2 cells. Furthermore, chemical compounds known to be inducers of B16 cells, did not induce differentiation of HL60 cells. Screening tests showed that the differentiation of HL60 cells was induced by extracts of 28 wild plants, 10 types of seaweed and 2 mushrooms, and melanogenesis of B16 2F2 cells was increased by extracts of 21 wild plants, 8 types of seaweed and 7 mushrooms. All of the alcoholic extracts of plants belonging to the subfamily Cichorioideae of the family Compositae caused cell differentiation of the melanoma cell line. The extracts of Chinese dandelion root, also inhibited cell growth and induced melanogenesis of B16 2F2 cells. We isolated the active compound from ethanol extracts of the crude drug. Chemical and physical data for the active compound were identical with those for lupeol, a lupane-type triterpene.

  12. NGF induces adult stem Leydig cells to proliferate and differentiate during Leydig cell regeneration

    SciTech Connect

    Zhang, Lei; Wang, Huaxi; Yang, Yan; Liu, Hui; Zhang, Qihao; Xiang, Qi; Ge, Renshan; Su, Zhijian; Huang, Yadong

    2013-06-28

    Highlights: •Nerve growth factor has shown significant changes on mRNA levels during Adult Leydig cells regeneration. •We established the organ culture model of rat seminiferous tubules with ethane dimethyl sulphonate (EDS) treatment. •Nerve growth factor has shown proliferation and differentiation-promoting effects on Adult stem Leydig cells. •Nerve growth factor induces progenitor Leydig cells to proliferate and differentiate and immature Leydig cells to proliferate. -- Abstract: Nerve growth factor (NGF) has been reported to be involved in male reproductive physiology. However, few reports have described the activity of NGF during Leydig cell development. The objective of the present study was to examine the role of NGF during stem-Leydig-cell (SLC) regeneration. We investigated the effects of NGF on Leydig-cell (LC) regeneration by measuring mRNA levels in the adult rat testis after ethane dimethanesulfonate (EDS) treatment. Furthermore, we used the established organ culture model of rat seminiferous tubules to examine the regulation of NGF during SLC proliferation and differentiation using EdU staining, real-time PCR and western blotting. Progenitor Leydig cells (PLCs) and immature Leydig cells (ILCs) were also used to investigate the effects of NGF on LCs at different developmental stages. NGF mRNA levels changed significantly during Leydig-cell regeneration in vivo. In vitro, NGF significantly promoted the proliferation of stem Leydig cells and also induced steroidogenic enzyme gene expression and 3β-HSD protein expression. The data from PLCs and ILCs showed that NGF could increase Cyclin D1 and Hsd 17b3 mRNA levels in PLCs and Cyclin D1 mRNA levels in ILCs. These results indicate that NGF may play an important role during LC regeneration by regulating the proliferation and differentiation of LCs at different developmental stages, from SLCs to PLCs and from PLCs to ILCs. The discovery of this effect of NGF on Leydig cells will provide useful

  13. Selection of the Inducer for the Differentiation of Chicken Embryonic Stem Cells into Male Germ Cells In Vitro

    PubMed Central

    Zhang, Yani; Wang, Yingjie; Zuo, Qisheng; Wang, Xiaoyan; Li, Dong; Tang, Beibei; Li, Bichun

    2016-01-01

    Several inducers have been used to differentiate embryonic stem cells (ESCs) into male germ cells but the induction process has been inefficient. To solve the problem of low efficiency of inducer for ESCs differentiation into male germ cells, all-trans retinoic acid (ATRA), Am80(the retinoic acid receptor agonist), and estradiol (E2) was used to induce ESCs to differentiate into male germ cells in vitro. ESCs were cultured in media containing ATRA, Am80, or E2 respectively which can differentiate ESCs into a germ cell lineage. In process of ATRA and Am80 induction Group, germ cell-like cells can be observed in 10 days; but have no in E2 induction Group. The marker genes of germ cell: Dazl, Stra8, C-kit, Cvh, integrinα6, and integrinβ1 all showed a significant up-regulation in the expression level. The ATRA-induction group showed high expression of C-kit and Cvh around 4 days, and integrinα6 and integrinβ1 were activated on day 10, respectively, while the E2-,Am80- induction group showed a high expression of C-kit as early as 4 days immunocytochemistry results shown that, integrinα6 and integrinβ1 could be detected in the ATRA-, Am80-, and E2-induction group, Positive clones in the ATRA group were greater in number than those in the other two groups. we conclued that ATRA, Am80, and E2 can promote the expression of the corresponding genes of germ cells, and had different effect on the differentiation of ESCs into male germ cells. ATRA was the most effective inducer of germ cell differentiation. PMID:27741318

  14. Differential activities of glucocorticoid-induced leucine zipper protein isoforms.

    PubMed

    Soundararajan, Rama; Wang, Jian; Melters, Daniël; Pearce, David

    2007-12-14

    Glucocorticoid-induced leucine zipper protein (GILZ) is expressed in both epithelial and immune tissues and modulates a variety of cellular functions, including proliferation and epithelial sodium channel (ENaC) activity. A number of reports have described various GILZ activities, focusing on a single isoform with molecular mass of approximately 17 kDa, now termed GILZ1. In GILZ immunoblots using a newly developed antiserum, we detected multiple species in extracts from cultured kidney cells. Mass spectrometric analysis revealed that one of these represented a previously uncharacterized distinct isoform of GILZ, GILZ2. Rapid amplification of cDNA ends was used to clone cDNAs corresponding to four isoforms, which, in addition to GILZ1 and GILZ2, included new isoforms GILZ3 and GILZ4. Heterologous expression of these four GILZ isoforms in cultured cells revealed striking functional differences. Notably, GILZ1 was the only isoform that significantly stimulated ENaC-mediated Na+ current in a kidney collecting duct cell line, although GILZ2 and GILZ3 also stimulated ENaC surface expression in HEK 293 cells. GILZ1 and GILZ3, and to a lesser extent GILZ2, inhibited ERK phosphorylation. Interestingly, GILZ4, which had no effect on either ENaC or ERK, potently suppressed cellular proliferation, as did GILZ1, but not GILZ2 or GILZ3. Finally, rat and mouse tissues all expressed multiple GILZ species but varied in the relative abundance of each. These data suggest that multiple GILZ isoforms are expressed in most cells and tissues and that these play distinct roles in regulating key cellular functions, including proliferation and ion transport. Furthermore, GILZ inhibition of ERK appears to play an essential role in stimulation of cell surface ENaC but not in inhibition of proliferation.

  15. Development of a rapid culture method to induce adipocyte differentiation of human bone marrow-derived mesenchymal stem cells

    SciTech Connect

    Ninomiya, Yuichi; Sugahara-Yamashita, Yzumi; Nakachi, Yutaka; Tokuzawa, Yoshimi; Okazaki, Yasushi; Nishiyama, Masahiko

    2010-04-02

    Human mesenchymal stem cells (hMSCs) derived from bone marrow are multipotent stem cells that can regenerate mesenchymal tissues such as adipose, bone or muscle. It is thought that hMSCs can be utilized as a cell resource for tissue engineering and as human models to study cell differentiation mechanisms, such as adipogenesis, osteoblastogenesis and so on. Since it takes 2-3 weeks for hMSCs to differentiate into adipocytes using conventional culture methods, the development of methods to induce faster differentiation into adipocytes is required. In this study we optimized the culture conditions for adipocyte induction to achieve a shorter cultivation time for the induction of adipocyte differentiation in bone marrow-derived hMSCs. Briefly, we used a cocktail of dexamethasone, insulin, methylisobutylxanthine (DIM) plus a peroxisome proliferator-activated receptor {gamma} agonist, rosiglitazone (DIMRo) as a new adipogenic differentiation medium. We successfully shortened the period of cultivation to 7-8 days from 2-3 weeks. We also found that rosiglitazone alone was unable to induce adipocyte differentiation from hMSCs in vitro. However, rosiglitazone appears to enhance hMSC adipogenesis in the presence of other hormones and/or compounds, such as DIM. Furthermore, the inhibitory activity of TGF-{beta}1 on adipogenesis could be investigated using DIMRo-treated hMSCs. We conclude that our rapid new culture method is very useful in measuring the effect of molecules that affect adipogenesis in hMSCs.

  16. Ornithine decarboxylase, polyamines and CD11b expression in HL-60 cells during differentiation induced by retinoic acid.

    PubMed

    Stabellini, Giordano; Brugnoli, F; Calastrini, C; Vizzotto, L; Vertemati, M; Baroni, T; Caramelli, E; Marinucci, L; Pellati, A; Bertagnolo, V

    2004-01-01

    Polyamines (PA) and retinoic acid affect mammalian cell growth, differentiation and apoptosis. Retinoic acid induces granulocytic differentiation of mieloid cell lines and, during this process, is responsible for the expression of CD11b, a surface antigen. In this study we investigate the effects of retinoic acid on HL-60 cells, monitoring ornithine decarboxylase (ODC) activity (enzyme rate of PA), putrescine (PUT), spermidine (SPD), spermine (SPM) levels, CD11b myeloid surface marker differentiation, cell cycle, and apoptosis. ODC activity and PUT levels are correlated with mieloid cell differentiation induced by retinoic acid treatment. Only the ODC/PUT ratio is connected with retinoic acid treated HL-60 cells. Treated cultures show a decrease of proliferation and a cell block in the G0/G1 phase, with consequent diminished S phase. The G0/G1 and S phases are significantly related to ODC activity and to PUT and SPD behavior, whereas in differentiating condition only the decrease of PUT is related to the S phase. CD11b expression, stimulated by retinoic acid treatment, is associated with the SPM trend. Total PA behavior agrees with apoptotic cell increase after 96 h of stimulation. Our data show that retinoic acid treatment modifies ODC activity and the turnover of PA. PUT, SPD and SPM, therefore, have a different role, and may be involved in the differentiative/apoptotic program of retinoic acid treated HL-60 cells.

  17. Neuroprotection from diazinon-induced toxicity in differentiating murine N2a neuroblastoma cells.

    PubMed

    Harris, Wayne; Sachana, Magda; Flaskos, John; Hargreaves, Alan J

    2009-11-01

    In previous work, the outgrowth of axon-like processes by differentiating mouse N2a neuroblastoma cells was shown to be inhibited by exposure to 10 microM diazinon. In the present work, N2a cells were induced to differentiate for 24 h in the presence and absence of 10 microM diazinon and 20% (v/v) conditioned medium derived from differentiating rat C6 glioma cells. Cells were then stained or lysed for morphological and biochemical analyses, respectively. The data showed that co-treatment with conditioned medium prevented the neurite inhibitory effect of diazinon. Furthermore, a significant recovery was also observed in the reduced levels of neurofilament heavy chain (NFH), heat shock protein-70 (HSP-70) and growth-associated protein-43 (GAP-43) observed as a result of diazinon treatment in the absence of conditioned medium, as seen by densitometric analysis of Western blots of cell lysates probed with monoclonal antibodies N52, BRM-22 and GAP-7B10. By contrast, no significant change was noted in the reactivity of cell lysates with antibodies against alpha- and beta-tubulin under any condition tested. After pre-incubation with a polyclonal anti-glial cell line-derived neurotrophic factor (GDNF) antibody, conditioned medium derived from rat C6 glioma cells lost its ability to protect N2a cells against the neurite inhibitory effects of diazinon. In conclusion, these data demonstrate that C6 conditioned medium protects N2a cells from the neurite inhibitory effects of diazinon by blocking molecular events leading to axon damage and that GDNF is implicated in these effects.

  18. Diverse effects of cyclic AMP variants on osteogenic and adipogenic differentiation of human mesenchymal stromal cells.

    PubMed

    Doorn, Joyce; Leusink, Maarten; Groen, Nathalie; van de Peppel, Jeroen; van Leeuwen, Johannes P T M; van Blitterswijk, Clemens A; de Boer, Jan

    2012-07-01

    Osteogenic differentiation of human mesenchymal stromal cells (hMSCs) may potentially be used in cell-based bone tissue-engineering applications to enhance the bone-forming potential of these cells. Osteogenic differentiation and adipogenic differentiation are thought to be mutually exclusive, and although several signaling pathways and cues that induce osteogenic or adipogenic differentiation, respectively, have been identified, there is no general consensus on how to optimally differentiate hMSCs into the osteogenic lineage. Some pathways have also been reported to be involved in both adipogenic and osteogenic differentiation, as for example, the protein kinase A (PKA) pathway, and the aim of this study was to investigate the role of cAMP/PKA signaling in differentiation of hMSCs in more detail. We show that activation of this pathway with dibutyryl-cAMP results in enhanced alkaline phosphatase expression, whereas another cAMP analog induces adipogenesis in long-term mineralization cultures. Adipogenic differentiation, induced by 8-bromo-cAMP, was accompanied by stronger PKA activity and higher expression of cAMP-responsive genes, suggesting that stronger activation correlates with adipogenic differentiation. In addition, a whole-genome expression analysis showed an increase in expression of adipogenic genes in 8-br-cAMP-treated cells. Furthermore, by means of quantitative polymerase chain reaction, we show differences in peroxisome proliferator-activated receptor-γ activation, either alone or in combination with dexamethasone, thus demonstrating differential effects of the PKA pathway, most likely depending on its mode of activation.

  19. Differential effects of protoporphyrin and uroporphyrin on murine mast cells

    SciTech Connect

    Lim, H.W.; Gigli, I.; Wasserman, S.I.

    1987-03-01

    To investigate the mechanisms responsible for the distinct cutaneous manifestations of erythropoietic protoporphyria and porphyria cutanea tarda, the effects of protoporphyrin (PP) and uroporphyrin (URO), the predominant porphyrins in the respective disease, on mast cells were examined. Release of preformed and generated mediators was assessed by the release of radioactivity from cells labeled with (/sup 3/H)serotonin and (/sup 14/C)arachidonic acid, respectively. Clinically relevant doses of PP (25-500 ng/ml) and 396-407 nm irradiation (3-16 X 10(2)J/m2) induced maximal net release of preformed mediators ,f 44.52 +/- 6.6 to 58.01 +/- 4.0% (mean +/- SE). In contrast, irradiation in the presence of URO (50-5000 ng/ml) resulted in less than 5% net release. (3H)Serotonin release induced by PP and irradiation was calcium-independent, and was not enhanced by phorbol 12-myristate 13-acetate, a known activator of protein kinase C. This release was suppressed by catalase, a scavenger of hydrogen peroxide. Furthermore, irradiation in the presence of PP, but not in the presence of URO, resulted in perturbation of cell membrane. Irradiation in the presence of PP also resulted in a maximal net release of generated mediators of 9.98 +/- 3.5% (mean +/- SE), whereas similar treatment in the presence of URO induced less than 0.5% net release. These results suggested that the burning, stinging, erythema, and edema experienced by patients with erythropoietic protoporphyria following sun exposure, and the lack of such findings in patients with porphyria cutanea tarda, may be explained, at least in part, by the differential effects of PP and URO on mast cells.

  20. Docosahexaenoic acid ester of phloridzin inhibit lipopolysaccharide-induced inflammation in THP-1 differentiated macrophages.

    PubMed

    Sekhon-Loodu, Satvir; Ziaullah; Rupasinghe, H P Vasantha

    2015-03-01

    Phloridzin or phlorizin (PZ) is a predominant phenolic compound found in apple and also used in various natural health products. Phloridzin shows poor absorption and cellular uptake due to its hydrophilic nature. The aim was to investigate and compare the effect of docosahexaenoic acid (DHA) ester of PZ (PZ-DHA) and its parent compounds (phloridzin and DHA), phloretin (the aglycone of PZ) and cyclooxygenase inhibitory drugs (diclofenac and nimesulide) on production of pro-inflammatory biomarkers in inflammation-induced macrophages by lipopolysaccharide (LPS)-stimulation. Human THP-1 monocytes were seeded in 24-well plates (5×10(5)/well) and treated with phorbol 12-myristate 13-acetate (PMA, 0.1μg/mL) for 48h to induce macrophage differentiation. After 48h, the differentiated macrophages were washed with Hank's buffer and treated with various concentrations of test compounds for 4h, followed by the LPS-stimulation (18h). Pre-exposure of PZ-DHA ester was more effective in reducing tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and cyclooxygenase-2 (COX-2) protein levels compared to DHA and nimesulide. However, diclofenac was the most effective in reducing prostaglandin (PGE2) level by depicting a dose-dependent response. However, PZ-DHA ester and DHA were the most effective in inhibiting the activation of nuclear factor-kappa B (NF-κB) among other test compounds. Our results suggest that PZ-DHA ester might possess potential therapeutic activity to treat inflammation related disorders such as type 2 diabetes, asthma, atherosclerosis and inflammatory bowel disease.

  1. The role of prolyl hydroxylase domain protein (PHD) during rosiglitazone-induced adipocyte differentiation.

    PubMed

    Kim, Juyoung; Kwak, Hyun Jeong; Cha, Ji-Young; Jeong, Yun-Seung; Rhee, Sang Dahl; Cheon, Hyae Gyeong

    2014-01-31

    Rosiglitazone, a well known insulin sensitizer, stimulates adipocyte differentiation via the activation of peroxisome proliferator-activated receptor γ (PPARγ). Previous two-dimensional proteomics studies using C3H10T1/2 murine mesenchymal pluripotent stem cells revealed that prolyl hydroxylase domain protein (PHD) levels significantly increased during rosiglitazone-induced adipocyte differentiation (RIAD). In this study, we investigated the functional role played by PHD during RIAD. Three PHD isoforms (PHD1, 2, and 3) were found to be up-regulated in C3H10T1/2 cells during RIAD, whereas PHD knockdown and treatment with PHD inhibitors (dimethyloxalyl glycine or ethyl-3,4-dihydroxybenzoate) blocked RIAD. PHD inhibition was found to be associated with increases in the levels of anti-adipogenic proteins such as GATA-3, KLF-2, and transcriptional coactivator with PDZ binding motif (TAZ), with their reduced ubiquitination, suggesting that PHDs evoke the ubiquitination/proteasomal degradation of anti-adipogenic proteins. On the other hand, MG-132 (a proteasomal inhibitor) prevented the degradation of anti-adipogenic proteins and retarded RIAD. PPARγ antagonists (bisphenol A diglycidyl ether or GW9662) blunted the effects of rosiglitazone on PHD regulation. Furthermore, putative PPARγ binding sites were identified in the promoter region of PHDs by ChIP-PCR, implying that rosiglitazone may induce PHD up-regulation directly by PPARγ activation. Consistent with in vitro results, oral administration of rosiglitazone to ob/ob mice for 2 weeks increased adipose PHD levels and decreased anti-adipogenic protein levels by increasing their ubiquitination. These results suggest that rosiglitazone increases PHD expression in a PPARγ-dependent manner and that this leads to the commitment of anti-adipogenic proteins to the ubiquitination-proteasomal pathway and to the subsequent induction of adipocyte differentiation.

  2. Analysis of the erythroid differentiation effect of flavonoid apigenin on K562 human chronic leukemia cells.

    PubMed

    Isoda, Hiroko; Motojima, Hideko; Onaga, Shoko; Samet, Imen; Villareal, Myra O; Han, Junkyu

    2014-09-05

    The erythroid differentiation-inducing effect of apigenin and its derivatives on human chronic myeloid leukemia K562 has been reported but the functional group in its structure responsible for the effect has not yet been elucidated. Here, we determined the moiety responsible for the erythroid differentiation induction effect of apigenin by using different flavonoids to represent the functional groups in its structure. In addition, we compared apigenin and apigetrin, a flavonoid similar in structure to apigenin except for the glycoside in its structure. Morphological changes as well as expressions of specific markers in K562 cells treated with apigenin were compared with those treated with apigetrin, flavone, 7-hydroxyflavone, chrysin, luteolin, or naringenin. The anti-proliferative and erythroid differentiation-inducing effect of apigenin and the five flavonoids were then investigated and their effects on the α, β, and γ globin genes expressions were compared using real-time PCR. Results of the comparison between apigenin and apigetrin revealed that the glycoside part of apigetrin does not have a role in the induction of cell differentiation. Based on glycophorin A expression, the potency of the other flavonoids for induction of differentiation, was: apigenin>chrysin>flavone/7-hydroxyflavone>luteolin/naringenin. Results of the analysis of the relationship between the structure and function of the flavonoids suggest that the apigenin-induced K562 cell differentiation was due to the 2-3 double bond and hydroxyl groups in its structure. This is the first study that identified the specific functional group in apigenin that impact the erythroid differentiation effect in K562 cells.

  3. Promoting effect of lactoferrin on barrier function and epithelial differentiation of human keratinocytes.

    PubMed

    Uchida, Ryo; Aoki, Reiji; Aoki-Yoshida, Ayako; Tajima, Atsushi; Takayama, Yoshiharu

    2017-02-01

    The purpose of this study was to elucidate the effects of bovine lactoferrin on keratinocyte differentiation and barrier function. Addition of bovine lactoferrin to differentiating HaCaT human keratinocytes led to increased transepithelial electrical resistance (TER), a marker of epithelial barrier function. This elevation was followed by upregulation of two differentiation markers, involucrin and filaggrin. The expression level of sterol regulatory element-binding protein-1 was also enhanced by bovine lactoferrin. The lactoferrin-induced upregulation of involucrin and filaggrin expression were confirmed in normal human epidermal keratinocytes (NHEK). Treatment with SB203580, a p38 mitogen-activated protein kinase (MAPK) α inhibitor, impaired the upregulation of involucrin and filaggrin expression in response to lactoferrin. The elevation of p38 MAPK phosphorylation was further enhanced by lactoferrin in the initial stage of differentiation of HaCaT keratinocytes. The findings suggest that bovine lactoferrin promotes epithelial differentiation by a p38-MAPK-dependent mechanism.

  4. The transcription factor osterix (SP7) regulates BMP6-induced human osteoblast differentiation.

    PubMed

    Zhu, Fengchang; Friedman, Michael S; Luo, Weijun; Woolf, Peter; Hankenson, Kurt D

    2012-06-01

    The transcription factor osterix (Sp7) is essential for osteoblastogenesis and bone formation in mice. Genome wide association studies have demonstrated that osterix is associated with bone mineral density in humans; however, the molecular significance of osterix in human osteoblast differentiation is poorly described. In this study we have characterized the role of osterix in human mesenchymal progenitor cell (hMSC) differentiation. We first analyzed temporal microarray data of primary hMSC treated with bone morphogenetic protein-6 (BMP6) using clustering to identify genes that are associated with osterix expression. Osterix clusters with a set of osteoblast-associated extracellular matrix (ECM) genes, including bone sialoprotein (BSP) and a novel set of proteoglycans, osteomodulin (OMD), osteoglycin, and asporin. Maximum expression of these genes is dependent upon both the concentration and duration of BMP6 exposure. Next we overexpressed and repressed osterix in primary hMSC using retrovirus. The enforced expression of osterix had relatively minor effects on osteoblastic gene expression independent of exogenous BMP6. However, in the presence of BMP6, osterix overexpression enhanced expression of the aforementioned ECM genes. Additionally, osterix overexpression enhanced BMP6 induced osteoblast mineralization, while inhibiting hMSC proliferation. Conversely, osterix knockdown maintained hMSC in an immature state by decreasing expression of these ECM genes and decreasing mineralization and hMSC proliferation. Overexpression of the osterix regulated gene OMD with retrovirus promoted mineralization of hMSC. These results suggest that osterix is necessary, but not sufficient for hMSC osteoblast differentiation. Osterix regulates the expression of a set of ECM proteins which are involved in terminal osteoblast differentiation.

  5. Lithium Reversibly Inhibits Schwann Cell Proliferation and Differentiation Without Inducing Myelin Loss.

    PubMed

    Piñero, Gonzalo; Berg, Randall; Andersen, Natalia Denise; Setton-Avruj, Patricia; Monje, Paula Virginia

    2016-12-05

    This study was undertaken to examine the bioactivity, specificity, and reversibility of lithium's action on the growth, survival, proliferation, and differentiation of cultured Schwann cells (SCs). In isolated SCs, lithium promoted a state of cell cycle arrest that featured extensive cell enlargement and c-Jun downregulation in the absence of increased expression of myelin-associated markers. In addition, lithium effectively prevented mitogen-induced S-phase entry without impairing cell viability. When lithium was administered together with differentiating concentrations of cyclic adenosine monophosphate (cAMP) analogs, a dramatic inhibition of the expression of the master regulator of myelination Krox-20 was observed. Likewise, lithium antagonized the cAMP-dependent expression of various myelin markers such as protein zero, periaxin, and galactocerebroside and allowed SCs to maintain high levels of expression of immature SC markers even in the presence of high levels of cAMP and low levels of c-Jun. Most importantly, the inhibitory action of lithium on SC proliferation and differentiation was shown to be dose dependent, specific, and reversible upon removal of lithium compounds. In SC-neuron cultures, lithium suppressed myelin sheath formation while preserving axonal integrity, SC-axon contact, and basal lamina formation. Lithium was unique in its ability to prevent the onset of myelination without promoting myelin degradation or SC dedifferentiation. To conclude, our results underscored an unexpected antagonistic action of lithium on SC mitogenesis and myelin gene expression. We suggest that lithium represents an attractive pharmacological agent to safely and reversibly suppress the onset of SC proliferation, differentiation, and myelination while maintaining the integrity of pre-existing myelinated fibers.

  6. Gallium nitride induces neuronal differentiation markers in neural stem/precursor cells derived from rat cerebral cortex.

    PubMed

    Chen, Chi-Ruei; Li, Yi-Chen; Young, Tai-Horng

    2009-09-01

    In the present study, gallium nitride (GaN) was used as a substrate to culture neural stem/precursor cells (NSPCs), isolated from embryonic rat cerebral cortex, to examine the effect of GaN on the behavior of NSPCs in the presence of basic fibroblast growth factor (bFGF) in serum-free medium. Morphological studies showed that neurospheres maintained their initial shape and formed many long and thick processes with the fasciculate feature on GaN. Immunocytochemical characterization showed that GaN could induce the differentiation of NSPCs into neurons and astrocytes. Compared to poly-d-lysine (PDL), the most common substrate used for culturing neurons, there was considerable expression of synapsin I for differentiated neurons on GaN, suggesting GaN could induce the differentiation of NSPCs towards the mature differentiated neurons. Western blot analysis showed that the suppression of glycogen synthase kinase-3beta (GSK-3beta) activity was one of the effects of GaN-promoted NSPC differentiation into neurons. Finally, compared to PDL, GaN could significantly improve cell survival to reduce cell death after long-term culture. These results suggest that GaN potentially has a combination of electric characteristics suitable for developing neuron and/or NSPC chip systems.

  7. Honeycomb-shaped surface topography induces differentiation of human mesenchymal stem cells (hMSCs): uniform porous polymer scaffolds prepared by the breath figure technique.

    PubMed

    Kawano, Takahito; Sato, Madoka; Yabu, Hiroshi; Shimomura, Masatsugu

    2013-11-29

    Polystyrene honeycomb scaffolds with different pore sizes were successfully fabricated by casting a polymer solution under humid conditions in order to investigate the effect of porous microtopography on hMSC differentiation. We have used honeycomb scaffolds to achieve the microtopography-induced differentiation of hMSCs. Honeycomb scaffolds led hMSCs to osteospecific and myospecific differentiations depending on the size of pores. This selective differentiation suggested that surface microtopography alone may be effective for using hMSCs in regenerative medicine and tissue engineering.

  8. Periodic solutions for ordinary differential equations with sublinear impulsive effects

    NASA Astrophysics Data System (ADS)

    Qian, Dingbian; Li, Xinyu

    2005-03-01

    The continuation method of topological degree is used to investigate the existence of periodic solutions for ordinary differential equations with sublinear impulsive effects. The applications of the abstract approach include the generalizations of some classical nonresonance theorem for impulsive equations, for instance, the existence theorem for asymptotically positively homogeneous differential systems and the existence theorem for second order equations with Landesman-Lazer conditions.

  9. Shockwaves induce osteogenic differentiation of human mesenchymal stem cells through ATP release and activation of P2X7 receptors.

    PubMed

    Sun, Dahui; Junger, Wolfgang G; Yuan, Changji; Zhang, Wenyan; Bao, Yi; Qin, Daming; Wang, Chengxue; Tan, Lei; Qi, Baochang; Zhu, Dong; Zhang, Xizheng; Yu, Tiecheng

    2013-06-01

    Shockwave treatment promotes bone healing of nonunion fractures. In this study, we investigated whether this effect could be due to adenosine 5'-triphosphate (ATP) release-induced differentiation of human mesenchymal stem cells (hMSCs) into osteoprogenitor cells. Cultured bone marrow-derived hMSCs were subjected to shockwave treatment and ATP release was assessed. Osteogenic differentiation and mineralization of hMSCs were evaluated by examining alkaline phosphatase activity, osteocalcin production, and calcium nodule formation. Expression of P2X7 receptors and c-fos and c-jun mRNA was determined with real-time reverse transcription polymerase chain reaction and Western blotting. P2X7-siRNA, apyrase, P2 receptor antagonists, and p38 MAPK inhibitors were used to evaluate the roles of ATP release, P2X7 receptors, and p38 MAPK signaling in shockwave-induced osteogenic hMSCs differentiation. Shockwave treatment released significant amounts (≈ 7 μM) of ATP from hMSCs. Shockwaves and exogenous ATP induced c-fos and c-jun mRNA transcription, p38 MAPK activation, and hMSC differentiation. Removal of ATP with apyrase, targeting of P2X7 receptors with P2X7-siRNA or selective antagonists, or blockade of p38 MAPK with SB203580 prevented osteogenic differentiation of hMSCs. Our findings indicate that shockwaves release cellular ATP that activates P2X7 receptors and downstream signaling events that caused osteogenic differentiation of hMSCs. We conclude that shockwave therapy promotes bone healing through P2X7 receptor signaling, which contributes to hMSC differentiation.

  10. The Apoplastic Copper AMINE OXIDASE1 Mediates Jasmonic Acid-Induced Protoxylem Differentiation in Arabidopsis Roots1

    PubMed Central

    Ghuge, Sandip A.; Carucci, Andrea; Rodrigues-Pousada, Renato A.; Tisi, Alessandra; Franchi, Stefano; Tavladoraki, Paraskevi; Cona, Alessandra

    2015-01-01

    Polyamines are involved in key developmental processes and stress responses. Copper amine oxidases oxidize the polyamine putrescine (Put), producing an aldehyde, ammonia, and hydrogen peroxide (H2O2). The Arabidopsis (Arabidopsis thaliana) amine oxidase gene At4g14940 (AtAO1) encodes an apoplastic copper amine oxidase expressed at the early stages of vascular tissue differentiation in roots. Here, its role in root development and xylem differentiation was explored by pharmacological and forward/reverse genetic approaches. Analysis of the AtAO1 expression pattern in roots by a promoter::green fluorescent protein-β-glucuronidase fusion revealed strong gene expression in the protoxylem at the transition, elongation, and maturation zones. Methyl jasmonate (MeJA) induced AtAO1 gene expression in vascular tissues, especially at the transition and elongation zones. Early protoxylem differentiation was observed upon MeJA treatment along with Put level decrease and H2O2 accumulation in wild-type roots, whereas Atao1 loss-of-function mutants were unresponsive to the hormone. The H2O2 scavenger N,N1-dimethylthiourea reversed the MeJA-induced early protoxylem differentiation in wild-type seedlings. Likewise, Put, which had no effect on Atao1 mutants, induced early protoxylem differentiation in the wild type, this event being counteracted by N,N1-dimethylthiourea treatment. Consistently, AtAO1-overexpressing plants showed lower Put levels and early protoxylem differentiation concurrent with H2O2 accumulation in the root zone where the first protoxylem cells with fully developed secondary wall thickenings are found. These results show that the H2O2 produced via AtAO1-driven Put oxidation plays a role in MeJA signaling leading to early protoxylem differentiation in root. PMID:25883242

  11. Androgens induce sebaceous differentiation in sebocyte cells expressing a stable functional androgen receptor.

    PubMed

    Barrault, Christine; Garnier, Julien; Pedretti, Nathalie; Cordier-Dirikoc, Sevda; Ratineau, Emeline; Deguercy, Alain; Bernard, François-Xavier

    2015-08-01

    Androgens act through non-genomic and androgen receptor (AR)-dependent genomic mechanisms. AR is expressed in the sebaceous gland and the importance of androgens in the sebaceous function is well established. However, the in vitro models used to date have failed to evidence a clear genomic effect (e.g., modification of gene expression profile) of androgens on human sebocyte cells. In order to study the impact of active androgens in sebocytes, we constructed a stable human sebocyte cell line derived from SEBO662 [17] constitutively expressing a fully functional AR. In these SEBO662 AR+ cells, dihydrotestosterone (DHT) induced AR nuclear translocation and the strong modulation of a set of transcripts (RASD1, GREB1...) known to be androgen-sensitive in other androgenic cells and tissues. Moreover, we observed that DHT precociously down-regulated markers for immature follicular cells (KRT15, TNC) and for hair lineage (KRT75, FST) and up-regulated the expression of genes potentially related to sebocyte differentiation (MUC1/EMA, AQP3, FADS2). These effects were fully confirmed at the protein level. In addition, DHT-stimulated SEBO662 AR+, cultured in a low-calcium defined keratinocyte medium without serum or any complement, neosynthesize lipids, including sebum lipids, and store increased amounts of triglycerides in lipid droplets. DHT also induces morphological changes, increases cell size, and treatments over 7 days lead to a time-dependent increase in the population of apoptotic DNA-fragmented cells. Taken together, these results show for the first time that active androgens alone can engage immature sebocytes in a clear lipogenic differentiation process (Graphical abstract). These effects depend on the expression of a functional AR in these cells. This model should be of interest for revisiting the mechanisms of the sebaceous function in vitro and for the design of relevant pharmacological models for drug or compound testing.

  12. Inhibition of astroglia-induced endothelial differentiation by inorganic lead: a role for protein kinase C.

    PubMed Central

    Laterra, J; Bressler, J P; Indurti, R R; Belloni-Olivi, L; Goldstein, G W

    1992-01-01

    Microvascular endothelial function in developing brain is particularly sensitive to lead toxicity, and it has been hypothesized that this results from the modulation of protein kinase C (PKC) by lead. We examined the effects of inorganic lead on an in vitro model of central nervous system endothelial differentiation in which astroglial cells induce central nervous system endothelial cells to form capillary-like structures. Capillary-like structure formation within C6 astroglial-endothelial cocultures was inhibited by lead acetate with 50% maximal inhibition at 0.5 microM total lead. Inhibition was independent of effects on cell viability or growth. Under conditions that inhibited capillary-like structure formation, we found that lead increased membrane-associated PKC in both C6 astroglial and endothelial cells. Prolonged exposure of C6 cells to 5 microM lead for up to 16 h resulted in a time-dependent increase in membranous PKC as determined by immunoblot analysis. Membranous PKC increased after 5-h exposures to as little as 50 nM lead and was maximal at approximately 1 microM. Phorbol esters were used to determine whether PKC modulation was causally related to the inhibition of endothelial differentiation by lead. Phorbol 12-myristate 13-acetate (10 nM) inhibited capillary-like structure formation by 65 +/- 5%, whereas 4 alpha-phorbol 12,13-didecanoate was without effect. These findings suggest that inorganic lead induces cerebral microvessel dysfunction by interfering with PKC modulation in microvascular endothelial or perivascular astroglial cells. Images PMID:1438272

  13. Dexamethasone-dependent inhibition of differentiation of C2 myoblasts bearing steroid-inducible N-ras oncogenes

    PubMed Central

    1988-01-01

    ras proteins are localized to the plasma membrane where they are postulated to interact with growth factor receptors and other proximal elements in intracellular cascades triggered by growth factors. The molecular events associated with terminal differentiation of certain skeletal myoblasts are inhibited by specific polypeptide growth factors and by constitutive expression of transforming ras oncogenes. To determine whether the inhibitory effects of ras on myogenic differentiation were reversible and to investigate whether muscle- specific genes remained susceptible to ras-dependent repression in terminally differentiated myotubes, the murine myoblast cell line, C2, was transfected with a plasmid containing a mutationally activated human N-ras oncogene under transcriptional control of the steroid- sensitive promoter of the mouse mammary tumor virus long terminal repeat. Addition of dexamethasone to myoblasts bearing steroid- inducible ras oncogenes prevented myotube formation and induction of muscle creatine kinase and acetylcholine receptors. Inhibition of differentiation by dexamethasone occurred in a dose-dependent manner and was a titratable function of ras expression. In the presence of dexamethasone, myoblasts bearing steroid-inducible ras genes retained their dependence on exogenous growth factors to divide and exhibited contact inhibition of growth at confluent densities, indicating that the inhibitory effects of ras on differentiation were independent of cell proliferation. Removal of dexamethasone from N-ras-transfected myoblasts led to fusion and induction of muscle-specific gene products in a manner indistinguishable from control C2 cells. Examination of the effects of culture media conditioned by ras-transfected myoblasts on differentiation of normal C2 cells yielded no evidence for inhibition of differentiation via an autocrine mechanism. In contrast to the ability of N-ras to prevent up-regulation of muscle-specific gene products in myoblasts

  14. FGF1 Mediates Overnutrition-Induced Compensatory β-Cell Differentiation

    PubMed Central

    Page-McCaw, Patrick

    2016-01-01

    Increased insulin demand resulting from insulin resistance and/or overnutrition induces a compensatory increase in β-cell mass. The physiological factors responsible for the compensation have not been fully characterized. In zebrafish, overnutrition rapidly induces compensatory β-cell differentiation through triggering the release of a paracrine signal from persistently activated β-cells. We identified Fgf1 signaling as a key component of the overnutrition-induced β-cell differentiation signal in a small molecule screen. Fgf1 was confirmed as the overnutrition-induced β-cell differentiation signal, as inactivation of fgf1 abolished the compensatory β-cell differentiation. Furthermore, expression of human FGF1 solely in β-cells in fgf1−/− animals rescued the compensatory response, indicating that β-cells can be the source of FGF1. Additionally, constitutive secretion of FGF1 with an exogenous signal peptide increased β-cell number in the absence of overnutrition. These results demonstrate that fgf1 is necessary and FGF1 expression in β-cells is sufficient for the compensatory β-cell differentiation. We further show that FGF1 is secreted during prolonged activation of cultured mammalian β-cells and that endoplasmic reticulum stress acts upstream of FGF1 release. Thus, the recently discovered antidiabetes function of FGF1 may act partially through increasing β-cell differentiation. PMID:26420862

  15. Eosinophils from Murine Lamina Propria Induce Differentiation of Naïve T Cells into Regulatory T Cells via TGF-β1 and Retinoic Acid.

    PubMed

    Chen, Hong-Hu; Sun, Ai-Hua; Ojcius, David M; Hu, Wei-Lin; Ge, Yu-Mei; Lin, Xu'ai; Li, Lan-Juan; Pan, Jian-Ping; Yan, Jie

    2015-01-01

    Treg cells play a crucial role in immune tolerance, but mechanisms that induce Treg cells are poorly understood. We here have described eosinophils in lamina propria (LP) that displayed high aldehyde dehydrogenase (ALDH) activity, a rate-limiting step during all-trans retinoic acid (ATRA) synthesis, and expressed TGF-β1 mRNA and high levels of ATRA. Co-incubation assay confirmed that LP eosinophils induced the differentiation of naïve T cells into Treg cells. Differentiation promoted by LP eosinophils were inhibited by blocked either TGF-β1 or ATRA. Peripheral blood (PB) eosinophils did not produce ATRA and could not induce Treg differentiation. These data identifies LP eosinophils as effective inducers of Treg cell differentiation through a mechanism dependent on TGF-β1 and ATRA.

  16. Half-filled energy bands induced negative differential resistance in nitrogen-doped graphene.

    PubMed

    Li, Xiao-Fei; Lian, Ke-Yan; Qiu, Qi; Luo, Yi

    2015-03-07

    Nitrogen-doping brings novel properties and promising applications into graphene, but the underlying mechanism is still in debate. To determine the key factor in motivating the negative differential resistance (NDR) behaviour of nitrogen-doped graphene, the electronic structure and transport properties of an 11-dimer wide nitrogen-doped armchair graphene nanoribbon (N-AGNR) were systematically studied by first principles calculations. Both the effect of interaction between N-dopants and the effect of doping-sublattice on the NDR were examined for the first time. Taking into account the two effects, N-AGNR becomes metallic or semiconducting depending on the doping configuration, and its Fermi level varies in a large range. NDR was firmly verified not to be intrinsic for N-AGNRs. However, it is totally determined by whether nitrogen-doping induces half-filled energy bands (HFEBs) because it is HFEBs that cross the Fermi level and determine the transport properties of N-AGNR under low biases. With the bias increasing, the transmission spectrum near the Fermi level showed a flag shape, and therefore, the corresponding transport channel is totally suppressed at a certain bias, resulting in the NDR behaviour with a configuration-dependent peak-to-valley current ratio (PVCR) up to 10(4). Our findings give new insights into the microscopic mechanism of chemical doping induced NDR behaviour and will be useful in building NDR-based nanodevices in the future.

  17. Insulin-like Growth Factor 2 (IGF-2) Potentiates BMP-9-Induced Osteogenic Differentiation and Bone Formation

    PubMed Central

    Chen, Liang; Jiang, Wei; Huang, Jiayi; He, Bai-Cheng; Zuo, Guo-Wei; Zhang, Wenli; Luo, Qing; Shi, Qiong; Zhang, Bing-Qiang; Wagner, Eric R; Luo, Jinyong; Tang, Min; Wietholt, Christian; Luo, Xiaoji; Bi, Yang; Su, Yuxi; Liu, Bo; Kim, Stephanie H; He, Connie J; Hu, Yawen; Shen, Jikun; Rastegar, Farbod; Huang, Enyi; Gao, Yanhong; Gao, Jian-Li; Zhou, Jian-Zhong; Reid, Russell R; Luu, Hue H; Haydon, Rex C; He, Tong-Chuan; Deng, Zhong-Liang

    2010-01-01

    Efficient osteogenic differentiation and bone formation from mesenchymal stem cells (MSCs) should have clinical applications in treating nonunion fracture healing. MSCs are adherent bone marrow stromal cells that can self-renew and differentiate into osteogenic, chondrogenic, adipogenic, and myogenic lineages. We have identified bone morphogenetic protein 9 (BMP-9) as one of the most osteogenic BMPs. Here we investigate the effect of insulin-like growth factor 2 (IGF-2) on BMP-9-induced bone formation. We have found that endogenous IGF-2 expression is low in MSCs. Expression of IGF-2 can potentiate BMP-9-induced early osteogenic marker alkaline phosphatase (ALP) activity and the expression of later markers. IGF-2 has been shown to augment BMP-9-induced ectopic bone formation in the stem cell implantation assay. In perinatal limb explant culture assay, IGF-2 enhances BMP-9-induced endochondral ossification, whereas IGF-2 itself can promote the expansion of the hypertropic chondrocyte zone of the cultured limb explants. Expression of the IGF antagonists IGFBP3 and IGFBP4 leads to inhibition of the IGF-2 effect on BMP-9-induced ALP activity and matrix mineralization. Mechanistically, IGF-2 is further shown to enhance the BMP-9-induced BMPR-Smad reporter activity and Smad1/5/8 nuclear translocation. PI3-kinase (PI3K) inhibitor LY294002 abolishes the IGF-2 potentiation effect on BMP-9-mediated osteogenic signaling and can directly inhibit BMP-9 activity. These results demonstrate that BMP-9 crosstalks with IGF-2 through PI3K/AKT signaling pathway during osteogenic differentiation of MSCs. Taken together, our findings suggest that a combination of BMP-9 and IGF-2 may be explored as an effective bone-regeneration agent to treat large segmental bony defects, nonunion fracture, and/or osteoporotic fracture. © 2010 American Society for Bone and Mineral Research. PMID:20499340

  18. Facilitated Anion Transport Induces Hyperpolarization of the Cell Membrane That Triggers Differentiation and Cell Death in Cancer Stem Cells.

    PubMed

    Soto-Cerrato, Vanessa; Manuel-Manresa, Pilar; Hernando, Elsa; Calabuig-Fariñas, Silvia; Martínez-Romero, Alicia; Fernández-Dueñas, Víctor; Sahlholm, Kristoffer; Knöpfel, Thomas; García-Valverde, María; Rodilla, Ananda M; Jantus-Lewintre, Eloisa; Farràs, Rosa; Ciruela, Francisco; Pérez-Tomás, Ricardo; Quesada, Roberto

    2015-12-23

    Facilitated anion transport potentially represents a powerful tool to modulate various cellular functions. However, research into the biological effects of small molecule anionophores is still at an early stage. Here we have used two potent anionophore molecules inspired in the structure of marine metabolites tambjamines to gain insight into the effect induced by these compounds at the cellular level. We show how active anionophores, capable of facilitating the transmembrane transport of chloride and bicarbonate in model phospholipid liposomes, induce acidification of the cytosol and hyperpolarization of plasma cell membranes. We demonstrate how this combined effect can be used against cancer stem cells (CSCs). Hyperpolarization of cell membrane induces cell differentiation and loss of stemness of CSCs leading to effective elimination of this cancer cell subpopulation.

  19. [(Sp)-8-chloroadenosine 3',5'-cyclophosphate induced differentiation on human leukemia HL-60 cells].

    PubMed

    Su, J; Yang, X B; Wang, L X; Xu, B; Zhang, L H

    1996-01-01

    (Sp)-octyl 8-chloroadenosine 3',5'-cyclophosphate(OCC), a newly synthesized cAMP analog, strongly induced growth inhibition and differentiation in human leukemia HL-60 cells. The effects were dose- and time-dependent and irreversible. In flow cytometry, OCC brought about a block at the G1 phase of HL-60 cell cycle. Determined by incorporation assay, OCC was shown to strongly inhibit DNA synthesis without affecting the synthesis of RNA and protein in HL-60 cells. OCC activated the protein kinase A(PKA) in the cytosol of HL-60 cells and inhibited its binding to cAMP. The activities of PKA in the cytosol of HL-60 cells treated with OCC were more significantly increased than those in control cells. It can be concluded that OCC binds itself to PKA in competition with cAMP and, as a result, activates PKA.

  20. Insulin and growth hormone-releasing peptide-6 (GHRP-6) have differential beneficial effects on cell turnover in the pituitary, hypothalamus and cerebellum of streptozotocin (STZ)-induced diabetic rats.

    PubMed

    Granado, Miriam; García-Cáceres, Cristina; Tuda, María; Frago, Laura M; Chowen, Julie A; Argente, Jesús

    2011-04-30

    Poorly controlled type1 diabetes is associated with hormonal imbalances and increased cell death in different tissues, including the pituitary, hypothalamus and cerebellum. In the pituitary, lactotrophs are the cell population with the greatest increase in cell death, whereas in the hypothalamus and cerebellum astrocytes are most highly affected. Insulin treatment can delay, but does not prevent, diabetic complications. As ghrelin and growth hormone (GH) secretagogues are reported to prevent apoptosis in different tissues, and to modulate glucose homeostasis, a combined hormonal treatment may be beneficial. Hence, we analyzed the effect of insulin and GH-releasing peptide 6 (GHRP-6) on diabetes-induced apoptosis in the pituitary, hypothalamus and cerebellum of diabetic rats. Adult male Wistar rats were made diabetic by streptozotocin injection (65 mg/kg ip) and divided into four groups from diabetes onset: those receiving a daily sc injection of saline (1 ml/kg/day), GHRP-6 (150 μg/kg/day), insulin (1-8U/day) or insulin plus GHRP-6 for 8 weeks. Control non-diabetic rats received saline (1 ml/kg/day). Diabetes increased cell death in the pituitary, hypothalamus and cerebellum (P<0.05). In the pituitary, insulin treatment prevented diabetes-induced apoptosis (P<0.01), as well as the decline in prolactin and GH mRNA levels (P<0.05). In the hypothalamus, neither insulin nor GHRP-6 decreased diabetes-induced cell death. However, the combined treatment of insulin+GHRP-6 prevented the diabetes induced-decrease in glial fibrillary acidic protein (GFAP) levels (P<0.05). In the cerebellum, although insulin treatment increased GFAP levels (P<0.01), only the combined treatment of insulin+ GHRP-6 decreased diabetes-induced apoptosis (P<0.05). In conclusion, insulin and GHRP-6 exert tissue specific effects in STZ-diabetic rats and act synergistically on some processes. Indeed, insulin treatment does not seem to be effective on preventing some of the diabetes-induced alterations

  1. Differential vascularization of nematode-induced feeding sites

    PubMed Central

    Hoth, Stefan; Stadler, Ruth; Sauer, Norbert; Hammes, Ulrich Z.

    2008-01-01

    Sedentary nematodes are destructive plant pathogens that cause significant yield losses. In the roots of their host plants, cyst nematodes (CNs) and root-knot nematodes (RKNs) induce different, highly specialized feeding sites—syncytia or giant cells (GCs), respectively—to optimize nutrient uptake. We compared the mechanisms by which nutrients are delivered from the model host plant, Arabidopsis, to GCs induced by the RKN Meloidogyne incognita or to syncytia induced by the CN Heterodera schachtii. From previous work, syncytia were known to be symplastically connected to newly formed host phloem composed of sieve elements (SEs) and companion cells. Here we studied the formation of plasmodesmata (PD) during GC and syncytia development by monitoring a viral movement protein that targets branched PD and the development of host phloem during GC formation by applying confocal laser scanning microscopy and immunocytochemistry. Analyses of plants expressing soluble or membrane-anchored green fluorescent protein in their phloem demonstrated symplastic isolation of GCs. GCs were found to be embedded in a tissue that consists exclusively of SEs. These de novo-formed SEs, contained nuclei and were interconnected by secondary PD. A similar interconnection of SEs was observed around syncytia. However, these secondary PD were also present at the SE–syncytium interface, demonstrating the postulated symplastic connection. Our results show that CNs and RKNs, despite their close phylogenetic relatedness, employ fundamentally different strategies to withdraw nutrients from host plants. PMID:18711135

  2. SRY alone can induce normal male sexual differentiation

    SciTech Connect

    Lopez, M.; Torres, L.; Cervantes, A.

    1995-01-30

    Most individuals with the rare 46,XX male {open_quotes}syndrome{close_quotes} arise due to an unequal interchange between Xp and Yp termini during paternal meiosis. The pattern of Y-sequences in these patients varies considerably, but very few cases have been reported showing only SRY. The phenotype in these patients is also variable ranging from severe impairment of the external genitalia through hypospadias and/or cryptorchidism to occasional normal male phenotype. We report a Mexican 46,XX male patient without genital ambiguities in whom DNA analysis showed the presence of SRY and the absence of ZFY. We conclude that in this case SRY alone was enough for complete male sexual differentiation. 25 refs., 1 fig.

  3. Differentiation of murine embryonic stem and induced pluripotent stem cells to renal lineage in vitro

    SciTech Connect

    Morizane, Ryuji; Monkawa, Toshiaki; Itoh, Hiroshi

    2009-12-25

    Embryonic stem (ES) cells which have the unlimited proliferative capacity and extensive differentiation potency can be an attractive source for kidney regeneration therapies. Recent breakthroughs in the generation of induced pluripotent stem (iPS) cells have provided with another potential source for the artificially-generated kidney. The purpose of this study is to know how to differentiate mouse ES and iPS cells into renal lineage. We used iPS cells from mouse fibroblasts by transfection of four transcription factors, namely Oct4, Sox2, c-Myc and Klf4. Real-time PCR showed that renal lineage markers were expressed in both ES and iPS cells after the induction of differentiation. It also showed that a tubular specific marker, KSP progressively increased to day 18, although the differentiation of iPS cells was slower than ES cells. The results indicated that renal lineage cells can be differentiated from both murine ES and iPS cells. Several inducing factors were tested whether they influenced on cell differentiation. In ES cells, both of GDNF and BMP7 enhanced the differentiation to metanephric mesenchyme, and Activin enhanced the differentiation of ES cells to tubular cells. Activin also enhanced the differentiation of iPS cells to tubular cells, although the enhancement was lower than in ES cells. ES and iPS cells have a potential to differentiate to renal lineage cells, and they will be an attractive resource of kidney regeneration therapy. This differentiation is enhanced by Activin in both ES and iPS cells.

  4. Nitric oxide synthase mediates PC12 differentiation induced by the surface topography of nanostructured TiO2

    PubMed Central

    2013-01-01

    Background Substrate nanoscale topography influences cell proliferation and differentiation through mechanisms that are at present poorly understood. In particular the molecular mechanism through which cells 'sense’ and adapt to the substrate and activate specific intracellular signals, influencing cells survival and behavior, remains to be clarified. Results To characterize these processes at the molecular level we studied the differentiation of PC12 cells on nanostructured TiO2 films obtained by supersonic cluster beam deposition. Our findings indicate that, in PC12 cells grown without Nerve Growth Factor (NGF), the roughness of nanostructured TiO2 triggers neuritogenesis by activating the expression of nitric oxide synthase (NOS) and the phospho-extracellular signal-regulated kinase 1/2 (pERK1/2) signaling. Differentiation is associated with an increase in protein nitration as observed in PC12 cells grown on flat surfaces in the presence of NGF. We demonstrate that cell differentiation and protein nitration induced by topography are not specific for PC12 cells but can be regarded as generalized effects produced by the substrate on different neuronal-like cell types, as shown by growing the human neuroblastoma SH-SY5Y cell line on nanostructured TiO2. Conclusion Our data provide the evidence that the nitric oxide (NO) signal cascade is involved in the differentiation process induced by nanotopography, adding new information on the mechanism and proteins involved in the neuritogenesis triggered by the surface properties. PMID:24119372

  5. Dexamethasone Induces Cardiomyocyte Terminal Differentiation via Epigenetic Repression of Cyclin D2 Gene.

    PubMed

    Gay, Maresha S; Dasgupta, Chiranjib; Li, Yong; Kanna, Angela; Zhang, Lubo

    2016-08-01

    Dexamethasone treatment of newborn rats inhibited cardiomyocyte proliferation and stimulated premature terminal differentiation of cardiomyocytes in the developing heart. Yet mechanisms remain undetermined. The present study tested the hypothesis that the direct effect of glucocorticoid receptor-mediated epigenetic repression of cyclin D2 gene in the cardiomyocyte plays a key role in the dexamethasone-mediated effects in the developing heart. Cardiomyocytes were isolated from 2-day-old rats. Cells were stained with a cardiomyocyte marker α-actinin and a proliferation marker Ki67. Cyclin D2 expression was evaluated by Western blot and quantitative real-time polymerase chain reaction. Promoter methylation of CcnD2 was determined by methylated DNA immunoprecipitation (MeDIP). Overexpression of Cyclin D2 was conducted by transfection of FlexiCcnD2 (+CcnD2) construct. Treatment of cardiomyocytes isolated from newborn rats with dexamethasone for 48 hours significantly inhibited cardiomyocyte proliferation with increased binucleation and decreased cyclin D2 protein abundance. These effects were blocked with Ru486 (mifepristone). In addition, the dexamethasone treatment significantly increased cyclin D2 gene promoter methylation in newborn rat cardiomyocytes. 5-Aza-2'-deoxycytidine inhibited dexamethasone-mediated promoter methylation, recovered dexamethasone-induced cyclin D2 gene repression, and blocked the dexamethasone-elicited effects on cardiomyocyte proliferation and binucleation. In addition, the overexpression of cyclin D2 restored the dexamethasone-mediated inhibition of proliferation and increase in binucleation in newborn rat cardiomyocytes. The results demonstrate that dexamethasone acting on glucocorticoid receptors has a direct effect and inhibits proliferation and stimulates premature terminal differentiation of cardiomyocytes in the developing heart via epigenetic repression of cyclin D2 gene.

  6. Amentoflavone protects against high fat-induced metabolic dysfunction: Possible role of the regulation of adipogenic differentiation.

    PubMed

    Chen, Guangyong; Han, Yangdong; He, Wang; Liang, Feng

    2016-12-01

    In the present study, we evaluated the protective effects of amentoflavone (AMF) against high-fat (HF) diet-induced metabolic dysfunction and focused on the influence of AMF on adipogenic differentiation during 3T3-L1 adipocyte differentiation. For this purpose, male Wistar rats were fed a HF diet or a HF diet with AMF (10 or 50 mg/kg). We found that AMF protected against HF diet-induced metabolic dysfunction in a dose-dependent manner, as evidenced by a decrease in the fasting blood glucose levels, fasting insulin levels and the homeostatic model assessment-insulin resistance index (HOMA‑IR), as well as by a decrease in the glucose level, as shown by the intraperitoneal glucose tolerance test and intraperitoneal insulin tolerance test. Moreover, the results revealed that AMF significantly inhibited the increase in body weight, the weight of perirenal adipose tissues and the serum triglyceride (TG) content of the rats fed the HF diet in a dose-dependent manner. AMF also inhibited the accumulation of oil droplets in differentiated 3T3-L1 adipocytes in a concentration-dependent manner. The incubation of the cells with AMF for 0-8, 0-2, 2-4, or 4-8 days markedly inhibited adipogenesis. During the early phase of the adipocyte differentiation of 3T3-L1 cells, AMF decreased CCAAT/enhancer-binding protein (C/EBP) β expression in a concentration-dependent manner, leading to the inhibition of mitotic clonal expansion (MCE). Moreover, our results demonstrated that AMF significantly increased reactive oxygen species (ROS) generation in the cells and the antioxidant, N-acetylcysteine (NAC), markedly attenuated the inhibitory effects of AMF on adipogenesis. AMF also inhibited the expression of peroxisome proliferator-activated receptor γ (PPARγ) and C/EBPα and the expression of downstream targets in a concentration-dependent manner. The overexpression of PPARγ and C/EBPα  (by transfection with respective overexpression plasmids) attentuated the

  7. Amentoflavone protects against high fat-induced metabolic dysfunction: Possible role of the regulation of adipogenic differentiation

    PubMed Central

    Chen, Guangyong; Han, Yangdong; He, Wang; Liang, Feng

    2016-01-01

    In the present study, we evaluated the protective effects of amentoflavone (AMF) against high-fat (HF) diet-induced metabolic dysfunction and focused on the influence of AMF on adipogenic differentiation during 3T3-L1 adipocyte differentiation. For this purpose, male Wistar rats were fed a HF diet or a HF diet with AMF (10 or 50 mg/kg). We found that AMF protected against HF diet-induced metabolic dysfunction in a dose-dependent manner, as evidenced by a decrease in the fasting blood glucose levels, fasting insulin levels and the homeostatic model assessment-insulin resistance index (HOMA-IR), as well as by a decrease in the glucose level, as shown by the intraperitoneal glucose tolerance test and intraperitoneal insulin tolerance test. Moreover, the results revealed that AMF significantly inhibited the increase in body weight, the weight of perirenal adipose tissues and the serum triglyceride (TG) content of the rats fed the HF diet in a dose-dependent manner. AMF also inhibited the accumulation of oil droplets in differentiated 3T3-L1 adipocytes in a concentration-dependent manner. The incubation of the cells with AMF for 0–8, 0–2, 2–4, or 4–8 days markedly inhibited adipogenesis. During the early phase of the adipocyte differentiation of 3T3-L1 cells, AMF decreased CCAAT/enhancer-binding protein (C/EBP) β expression in a concentration-dependent manner, leading to the inhibition of mitotic clonal expansion (MCE). Moreover, our results demonstrated that AMF significantly increased reactive oxygen species (ROS) generation in the cells and the antioxidant, N-acetylcysteine (NAC), markedly attenuated the inhibitory effects of AMF on adipogenesis. AMF also inhibited the expression of peroxisome proliferator-activated receptor γ (PPARγ) and C/EBPα and the expression of downstream targets in a concentration-dependent manner. The overexpression of PPARγ and C/EBPα (by transfection with respective overexpression plasmids) attentuated the inhibitory effects

  8. Polarization of an electroactive functional film on titanium for inducing osteogenic differentiation

    PubMed Central

    Zhou, Zhengnan; Li, Weiping; He, Tianrui; Qian, Lei; Tan, Guoxin; Ning, Chengyun

    2016-01-01

    To enhance the surface bioactivity of titanium (Ti) prostheses, an electroactive polyvinylidene fluoride (PVDF) film was prepared on a Ti substrate to provide a mimetic of the electrical microenvironment, which facilitated the performance of cell functions. The results of cell proliferation and differentiation assays indicated that polarization of the PVDF-Ti (PTi) altered its surface charge, thus inducing adhesion, proliferation and osteogenic differentiation of cells. The polarized PVDF-Ti (PPTi) may therefore find applications in bone regeneration. PMID:27762318

  9. Polarization of an electroactive functional film on titanium for inducing osteogenic differentiation

    NASA Astrophysics Data System (ADS)

    Zhou, Zhengnan; Li, Weiping; He, Tianrui; Qian, Lei; Tan, Guoxin; Ning, Chengyun

    2016-10-01

    To enhance the surface bioactivity of titanium (Ti) prostheses, an electroactive polyvinylidene fluoride (PVDF) film was prepared on a Ti substrate to provide a mimetic of the electrical microenvironment, which facilitated the performance of cell functions. The results of cell proliferation and differentiation assays indicated that polarization of the PVDF-Ti (PTi) altered its surface charge, thus inducing adhesion, proliferation and osteogenic differentiation of cells. The polarized PVDF-Ti (PPTi) may therefore find applications in bone regeneration.

  10. Cyclic adenosine monophosphate (cAMP)-induced histone hyperacetylation contributes to its antiproliferative and differentiation-inducing activities.

    PubMed

    Yoo, Seungwan; Lee, Yong Gyu; Kim, Ji Hye; Byeon, Se Eun; Rho, Ho Sik; Cho, Jae Youl; Hong, Sungyoul

    2012-01-01

    Histone acetylation is linked to the control of chromatin remodeling, which is involved in cell growth, proliferation, and differentiation. It is not fully understood whether cyclic adenosine monophosphate (cAMP), a representative differentiation-inducing molecule, is able to modulate histone acetylation as part of its anticancer activity. In the present study, we aimed to address this issue using cell-permeable cAMP, i.e. dibutyryl cAMP (dbcAMP) and C6 glioma cells. As reported previously, under the conditions of our studies, treatment with dbcAMP clearly arrested C6 cell proliferation and altered their morphology. Its antiproliferative and differentiation-inducing activity in C6 glioma cells involved upregulation of p219WAF/CIP), p27(kip1), glial fibrillary acidic protein (GFAP), and Cx43, as well as downregulation of vimentin. Furthermore, dbcAMP modulated the phosphorylation of ERK and Akt in a time-dependent manner and altered the colocalization pattern of phospho-Src and the actin cytoskeleton. Interestingly, dbcAMP upregulated the enzyme activity of histone acetyltransferase (HAT) and, in parallel, enhanced cellular acetyllysine levels. Finally, the hyperacetylation-inducing compound, sodium butyrate (NaB), a histone deacetylase (HDAC) inhibitor, displayed similar anticancer activity to dbcAMP. Therefore, our data suggest that antiproliferative and differentiation-inducing activities of dbcAMP may be generated by its enhanced hyperacetylation function.

  11. Direct hepatic differentiation of mouse embryonic stem cells induced by valproic acid and cytokines

    PubMed Central

    Dong, Xue-Jun; Zhang, Guo-Rong; Zhou, Qing-Jun; Pan, Ruo-Lang; Chen, Ye; Xiang, Li-Xin; Shao, Jian-Zhong

    2009-01-01

    AIM: To develop a protocol for direct hepatic lineage differentiation from early developmental progenitors to a population of mature hepatocytes. METHODS: Hepatic progenitor cells and then mature hepatocytes from mouse embryonic stem (ES) cells were obtained in a sequential manner, induced by valproic acid (VPA) and cytokines (hepatocyte growth factor, epidermal growth factor and insulin). Morphological changes of the differentiated cells were examined by phase-contrast microscopy and electron microscopy. Reverse transcription polymerase chain reaction and immunocytochemical analyses were used to evaluate the gene expression profiles of the VPA-induced hepatic progenitors and the hepatic progenitor-derived hepatocytes. Glycogen storage, cytochrome P450 activity, transplantation assay, differentiation of bile duct-like structures and tumorigenic analyses were performed for the functional identification of the differentiated cells. Furthermore, FACS and electron microscopy were used for the analyses of cell cycle profile and apoptosis in VPA-induced hepatic differentiated cells. RESULTS: Based on the combination of VPA and cytokines, mouse ES cells differentiated into a uniform and homogeneous cell population of hepatic progenitor cells and then matured into functional hepatocytes. The progenitor population shared several characteristics with ES cells and hepatic stem/progenitor cells, and represented a novel progenitor cell between ES and hepatic oval cells in embryonic development. The differentiated hepatocytes from progenitor cells shared typical characteristics with mature hepatocytes, including the patterns of gene expression, immunological markers, in vitro hepatocyte functions and in vivo capacity to restore acute-damaged liver function. In addition, the differentiation of hepatic progenitor cells from ES cells was accompanied by significant cell cycle arrest and selective survival of differentiating cells towards hepatic lineages. CONCLUSION: Hepatic cells

  12. A Cell-Based High-Throughput Screening for Inducers of Myeloid Differentiation

    PubMed Central

    Radomska, Hanna S.; Jernigan, Finith; Nakayama, Sohei; Jorge, Susan E.; Sun, Lijun; Tenen, Daniel G.; Kobayashi, Susumu S.

    2015-01-01

    Recent progress of genetic studies has dramatically unveiled pathogenesis of acute myeloid leukemia (AML). However, overall survival of AML still remains unsatisfactory and development of novel therapeutics is required. CCAAT/Enhancer Binding Protein α (C/EBPα) is one of crucial transcription factors that induce granulocytic differentiation and its activity is perturbed in human myeloid leukemias. As its re-expression can induce differentiation and subsequent apoptosis of leukemic cells in vitro, we hypothesized that chemical compounds that restore C/EBPα expression and/or activity would lead to myeloid differentiation of leukemic cells. Using a cell-based high-throughput screening, we identified 2-[(E)-2-(3,4-dihydroxyphenyl)vinyl]-3-(2-methoxyphenyl)-4(3H)-quinazolinone as a potent inducer of C/EBPα and myeloid differentiation. Leukemia cell lines and primary blast cells isolated from human AML patients treated with ICCB280 demonstrated evidence of morphological and functional differentiation, as well as massive apoptosis. We performed conformational analyses of the high-throughput screening hit compounds to postulate the spatial requirements for high potency. Our results warrant a development of novel differentiation therapies and significantly impact care of AML patients with unfavorable prognosis in the near future. PMID:26109609

  13. Identification of an IL-4-Inducible Gene Expressed in Differentiating Lymphocytes and Male Germ Cells

    PubMed Central

    Nabavi, Nasrin; Grusby, Michael J.; Finn, Patricia W.; Wolgemuth, Debra J.; Glimcher, Laurie H.

    1990-01-01

    Interleukin 4 (IL-4) is a cytokine that is involved in the differentiation of B and T lymphocytes. In this report, we describe the identification of a novel gene, N.52, which was cloned from the murine pre-B cell line R8205 grown in the presence of IL-4 for 48 hr. Although N.52 expression is detectable at low levels in unstimulated R8205 cells, the level of N.52 dramatically increases after only .4 hr exposure to IL-4 and remains at a high .level up to 48 hr. Although N.52 expression is low or absent in normal spleen B and T cells, its expression can be induced by the differentiation signals delivered by LPS in B cells and by Con A in T-cell hybrids. While N.52 mRNA is absent in all highly differentiated organs, it is detectable in stem cell harboring lymphoid tissues such as bone marrow, fetal liver, and thymus. Furthermore, N.52 mRNA is expressed at strikingly high levels in the testis, specifically in differentiating male germ cells. It is induced by differentiation signals triggered by the combination of cyclic AMP and retinoic acid in teratocarcinoma F9 cells. Taken together, these data suggest that N.52 is a developmentally regulated gene whose expression in cells of the immune and reproductive systems may be controlled by stimuli that induce differentiation. PMID:2136202

  14. Derivation, expansion and differentiation of induced pluripotent stem cells in continuous suspension cultures

    PubMed Central

    Fluri, David A.; Tonge, Peter D.; Song, Hannah; Baptista, Ricardo P.; Shakiba, Nika; Shukla, Shreya; Clarke, Geoffrey; Nagy, Andras; Zandstra, Peter W.

    2016-01-01

    We demonstrate derivation of induced pluripotent stem cells (iPSCs) from terminally differentiated mouse cells in serum- and feeder-free stirred suspension cultures. Temporal analysis of global gene expression revealed high correlations between cells reprogrammed in suspension and cells reprogrammed in adhesion-dependent conditions. Suspension (S) reprogrammed iPSCs (SiPSCs) could be differentiated into all three germ layers in vitro and contributed to chimeric embryos in vivo. SiPSC generation allowed for efficient selection of reprogramming factor expressing cells based on their differential survival and proliferation in suspension. Seamless integration of SiPSC reprogramming and directed differentiation enabled the scalable production of functionally and phenotypically defined cardiac cells in a continuous single cell- and small aggregate-based process. This method is an important step towards the development of a robust PSC generation, expansion and differentiation technology. PMID:22447133

  15. In vivo differentiation of induced pluripotent stem cells into neural stem cells by chimera formation

    PubMed Central

    Choi, Hyun Woo; Hong, Yean Ju; Kim, Jong Soo; Song, Hyuk; Cho, Ssang Gu; Bae, Hojae; Kim, Changsung; Byun, Sung June; Do, Jeong Tae

    2017-01-01

    Like embryonic stem cells, induced pluripotent stem cells (iPSCs) can differentiate into all three germ layers in an in vitro system. Here, we developed a new technology for obtaining neural stem cells (NSCs) from iPSCs through chimera formation, in an in vivo environment. iPSCs contributed to the neural lineage in the chimera, which could be efficiently purified and directly cultured as NSCs in vitro. The iPSC-derived, in vivo-differentiated NSCs expressed NSC markers, and their gene-expression pattern more closely resembled that of fetal brain-derived NSCs than in vitro-differentiated NSCs. This system could be applied for differentiating pluripotent stem cells into specialized cell types whose differentiation protocols are not well established. PMID:28141814

  16. Hypoxia-inducible factor-1α induces ErbB4 signaling in the differentiating mammary gland.

    PubMed

    Paatero, Ilkka; Seagroves, Tiffany N; Vaparanta, Katri; Han, Wen; Jones, Frank E; Johnson, Randall S; Elenius, Klaus

    2014-08-08

    Conditional knock-out of Hif1a in the mouse mammary gland impairs lobuloalveolar differentiation during lactation. Here, we demonstrate that expression of ErbB4 was reduced in the lobulalveoli of mice with mammary gland-specific deletion of Hif1a. Erbb4 was not, however, a direct target gene for transcriptional regulation by HIF-1α in vitro. HIF-1α overexpression or HIF accumulating prolyl hydroxylase inhibitors reduced ErbB4 endocytosis, promoted transcriptional co-regulatory activity of ErbB4, and stimulated ErbB4-induced differentiation of mammary carcinoma cells. Consistently, RNA interference-mediated down-regulation of HIF-1α resulted in reduced ErbB4 protein amount and reduced mammary carcinoma cell differentiation. These findings indicate that HIF-1α is a physiologically relevant regulator of ErbB4 and that ErbB4 is involved in HIF-regulated differentiation of the mammary gland.

  17. Differential magnetometer method applied to measurement of geomagnetically induced currents in Southern African power networks

    NASA Astrophysics Data System (ADS)

    Matandirotya, Electdom; Cilliers, Pierre. J.; Van Zyl, Robert R.; Oyedokun, David T.; Villiers, Jean

    2016-03-01

    Geomagnetically induced currents (GICs) in conductors connected to the Earth are driven by an electric field produced by a time-varying magnetic field linked to magnetospheric-ionospheric current perturbations during geomagnetic storms. The GIC measurements are traditionally done on the neutral-to-ground connections of power transformers. A method of inferring the characteristics of GIC in power lines using differential magnetic field measurements is presented. Measurements of the GIC in the power lines connected to a particular power transformer are valuable in the verification of the modeling of GIC in the power transmission network. The differential magnetometer method (DMM) is an indirect method used to estimate the GIC in a power line. With the DMM, low-frequency GIC in the power line is estimated from the difference between magnetic field recordings made directly underneath the power line and at some distance away, where the magnetic field of the GIC in the transmission line has negligible effect. Results of the first application of the DMM to two selected sites of the Southern African power transmission network are presented. The results show that good quality GIC measurements are achieved through the DMM using Commercially-Off-The-Shelf magnetometers.

  18. Transforming growth factor alpha induces collagen degradation and cell migration in differentiating human epidermal raft cultures.

    PubMed Central

    Turksen, K; Choi, Y; Fuchs, E

    1991-01-01

    When cultured on plastic and treated with transforming growth factor alpha (TGF alpha), human keratinocytes exhibit an increase in proliferation at the colony periphery, apparently as a consequence of enhanced cell migration (Barrandon and Green, 1987). To investigate the effects of TGF alpha on a differentiating stratified squamous epithelium and to begin to examine the molecular basis mediating this influence, we cultured human epidermal cells on a gelled lattice of collagen and fibroblasts, floating on the air-liquid interface. Under these conditions, raft cultures differentiate and exhibit morphological and biochemical features of human skin in vivo (Asselineau et al., 1986; Kopan et al., 1987). When 3-wk-old raft cultures were treated with TGF alpha, basal cells showed a marked increase in cell proliferation. At elevated concentrations of TGF alpha, the organization of cells within the artificial tissue changed and islands of basal cells entered the collagen matrix. Biochemical analysis of the response revealed that type I collagenase and gelatinase were induced by keratinocytes within 12 h after TGF alpha treatment. In contrast, invasion of basal cells into the collagen matrix was not significant until 48-72 h post-treatment, suggesting that collagenase and gelatinase production may be a prerequisite to this phenomenon. These results have important implications for the possible role of TGF alpha in squamous cell carcinoma and tumor invasion. Images PMID:1663788

  19. Effects of pulsed electromagnetic field frequencies on the osteogenic differentiation of human mesenchymal stem cells.

    PubMed

    Luo, Fei; Hou, Tianyong; Zhang, Zehua; Xie, Zhao; Wu, Xuehui; Xu, Jianzhong

    2012-04-01

    The purpose of this study was to evaluate the effect of different frequencies of pulsed electromagnetic fields on the osteogenic differentiation of human mesenchymal stem cells. Third-generation human mesenchymal stem cells were irradiated with different frequencies of pulsed electromagnetic fields, including 5, 25, 50, 75, 100, and 150 Hz, with a field intensity of 1.1 mT, for 30 minutes per day for 21 days. Changes in human mesenchymal stem cell morphology were observed using phase contrast microscopy. Alkaline phosphatase activity and osteocalcin expression were also determined to evaluate human mesenchymal stem cell osteogenic differentiation.Different effects were observed on human mesenchymal stem cell osteoblast induction following exposure to different pulsed electromagnetic field frequencies. Levels of human mesenchymal stem cell differentiation increased when the pulsed electromagnetic field frequency was increased from 5 hz to 50 hz, but the effect was weaker when the pulsed electromagnetic field frequency was increased from 50 Hz to 150 hz. The most significant effect on human mesenchymal stem cell differentiation was observed at of 50 hz.The results of the current study show that pulsed electromagnetic field frequency is an important factor with regard to the induction of human mesenchymal stem cell differentiation. Furthermore, a pulsed electromagnetic field frequency of 50 Hz was the most effective at inducing human mesenchymal stem cell osteoblast differentiation in vitro.

  20. Micro-RNA-21 regulates TGF-β-induced myofibroblast differentiation by targeting PDCD4 in tumor-stroma interaction.

    PubMed

    Yao, Qin; Cao, Siyu; Li, Chun; Mengesha, Asferd; Kong, Beihua; Wei, Mingqian

    2011-04-15

    Transforming growth factor-β1 (TGF-β1) induces stromal fibroblast-to-myofibroblast transdifferentiation in the tumor-stroma interactive microenvironment via modulation of multiple phenotypic and functional genes, which plays a critical role in tumor progression. Up to now, the involvement of micro-RNAs (miRNAs) and their roles in TGF-β1-induced myofibroblast differentiation in tumor-stroma interaction are unclear. Using quantitative real-time RT-PCR, we demonstrated that the expression of micro-RNA-21 (miR-21) was upregulated in activated fibroblasts after treatment with TGF-β1 or conditioned medium from cancer cells. To determine the potential roles of miR-21 in TGF-β1-mediated gene regulation during myofibroblast conversion, we showed that miR-21 expression was downregulated by miR-21 inhibitor and upregulated by miR-21 mimic. Interestingly, downregulation of miR-21 with the inhibitor effectively inhibited TGF-β1-induced myofibroblast differentiation while upregulation of miR-21 with a mimic significantly promoted myofibroblast differentiation. We further demonstrated that MiR-21 directly targeted and downregulated programmed cell death 4 (PDCD4) gene, which in turn acted as a negative regulator of several phenotypic and functional genes of myofibroblasts. Taken together, these results suggested that miR-21 participated in TGF-β1-induced myofibroblast transdifferentiation in cancer stroma by targeting PDCD4.

  1. Dendrobium moniliforme Exerts Inhibitory Effects on Both Receptor Activator of Nuclear Factor Kappa-B Ligand-Mediated Osteoclast Differentiation in Vitro and Lipopolysaccharide-Induced Bone Erosion in Vivo.

    PubMed

    Baek, Jong Min; Kim, Ju-Young; Ahn, Sung-Jun; Cheon, Yoon-Hee; Yang, Miyoung; Oh, Jaemin; Choi, Min Kyu

    2016-03-01

    Dendrobium moniliforme (DM) is a well-known plant-derived extract that is widely used in Oriental medicine. DM and its chemical constituents have been reported to have a variety of pharmacological effects, including anti-oxidative, anti-inflammatory, and anti-tumor activities; however, no reports discuss the beneficial effects of DM on bone diseases such as osteoporosis. Thus, we investigated the relationship between DM and osteoclasts, cells that function in bone resorption. We found that DM significantly reduced receptor activator of nuclear factor kappa-B ligand (RANKL)-induced tartrate-resistant acid phosphatase (TRAP)-positive osteoclast formation; DM directly induced the down-regulation of c-Fos and nuclear factor of activated T cells c1 (NFATc1) without affecting other RANKL-dependent transduction pathways. In the later stages of osteoclast maturation, DM negatively regulated the organization of filamentous actin (F-actin), resulting in impaired bone-resorbing activity by the mature osteoclasts. In addition, micro-computed tomography (μ-CT) analysis of the murine model revealed that DM had a beneficial effect on lipopolysaccharide (LPS)-mediated bone erosion. Histological analysis showed that DM attenuated the degradation of trabecular bone matrix and formation of TRAP-positive osteoclasts in bone tissues. These results suggest that DM is a potential candidate for the treatment of metabolic bone disorders such as osteoporosis.

  2. Voltage-Gated K+ Channel, Kv3.3 Is Involved in Hemin-Induced K562 Differentiation.

    PubMed

    Song, Min Seok; Choi, Seon Young; Ryu, Pan Dong; Lee, So Yeong

    2016-01-01

    Voltage-gated K+ (Kv) channels are well known to be involved in cell proliferation. However, even though cell proliferation is closely related to cell differentiation, the relationship between Kv channels and cell differentiation remains poorly investigated. This study demonstrates that Kv3.3 is involved in K562 cell erythroid differentiation. Down-regulation of Kv3.3 using siRNA-Kv3.3 increased hemin-induced K562 erythroid differentiation through decreased activation of signal molecules such as p38, cAMP response element-binding protein, and c-fos. Down-regulation of Kv3.3 also enhanced cell adhesion by increasing integrin β3 and this effect was amplified when the cells were cultured with fibronectin. The Kv channels, or at least Kv3.3, appear to be associated with cell differentiation; therefore, understanding the mechanisms of Kv channel regulation of cell differentiation would provide important information regarding vital cellular processes.

  3. Rehmannia glutinosa oligosaccharide induces differentiation of bone marrow mesenchymal stem cells into cardiomyocyte-like cells.

    PubMed

    Wang, X H; Du, H W; Guo, X H; Wang, S W; Zhou, R B; Li, Y; Li, Z B; Zhao, Y S; Zhu, Q L

    2016-10-17

    The aim of this study was to observe the effect of Rehmannia glutinosa oligosaccharide (RGO) on differentiation of bone marrow mesenchymal stem cells (MSCs) into cardiomyocyte-like cells . Rat MSCs were isolated, treated, and grouped as follows: RGO treatment group, 5-azacytidine (5-aza) treatment group, RGO + 5-aza treatment group, and control group. Following a four-week induction period, cardiac troponin I (cTnI) levels in MSCs were quantified by chemiluminescence, and the levels of myocardial enzymes creatine kinase (CK) and creatine kinase isoenzyme-MB (CK-MB) were measured using a dry chemistry analyzer. The cTnI- and connexin 43 (Cx43)-positive MSC population was identified by immunofluorescence, and expression levels of cTnI and Cx43 were analyzed by western blots. Following induction, cTnI, CK, and CK-MB levels were significantly higher in the RGO + 5-aza group as compared with the RGO and 5-aza groups (P < 0.05). In addition, fluorescence intensity of cTnI and Cx43 was higher in the RGO + 5-aza group as compared with the RGO and 5-aza groups. No cTnI- or Cx43-positive cells were detected in the control group. Western blot analysis further confirmed that cTnI and Cx43 were not expressed in the control group, while cTnI and Cx43 was higher in the RGO + 5-aza group than in the RGO and 5-aza groups. These results suggest that MSCs can be induced by RGO to differentiate into cardiomyocyte-like cells in vitro, and that RGO in combination with 5-aza enhance differentiation of MSCs.

  4. Evaluating differential effects using regression interactions and regression mixture models

    PubMed Central

    Van Horn, M. Lee; Jaki, Thomas; Masyn, Katherine; Howe, George; Feaster, Daniel J.; Lamont, Andrea E.; George, Melissa R. W.; Kim, Minjung

    2015-01-01

    Research increasingly emphasizes understanding differential effects. This paper focuses on understanding regression mixture models, a relatively new statistical methods for assessing differential effects by comparing results to using an interactive term in linear regression. The research questions which each model answers, their formulation, and their assumptions are compared using Monte Carlo simulations and real data analysis. The capabilities of regression mixture models are described and specific issues to be addressed when conducting regression mixtures are proposed. The paper aims to clarify the role that regression mixtures can take in the estimation of differential effects and increase awareness of the benefits and potential pitfalls of this approach. Regression mixture models are shown to be a potentially effective exploratory method for finding differential effects when these effects can be defined by a small number of classes of respondents who share a typical relationship between a predictor and an outcome. It is also shown that the comparison between regression mixture models and interactions becomes substantially more complex as the number of classes increases. It is argued that regression interactions are well suited for direct tests of specific hypotheses about differential effects and regression mixtures provide a useful approach for exploring effect heterogeneity given adequate samples and study design. PMID:26556903

  5. Targeting Vaccine-Induced Extrafollicular Pathway of B Cell Differentiation Improves Rabies Postexposure Prophylaxis.

    PubMed

    Haley, Shannon L; Tzvetkov, Evgeni P; Meuwissen, Samantha; Plummer, Joseph R; McGettigan, James P

    2017-04-15

    Vaccine-induced B cells differentiate along two pathways. The follicular pathway gives rise to germinal centers (GCs) that can take weeks to fully develop. The extrafollicular pathway gives rise to short-lived plasma cells (PCs) that can rapidly secrete protective antibodies within days of vaccination. Rabies virus (RABV) postexposure prophylaxis (PEP) requires rapid vaccine-induced humoral immunity for protection. Therefore, we hypothesized that targeting extrafollicular B cell responses for activation would improve the speed and magnitude of RABV PEP. To test this hypothesis, we constructed, recovered, and characterized a recombinant RABV-based vaccine expressing murine B cell activating factor (BAFF) (rRABV-mBAFF). BAFF is an ideal molecule to improve early pathways of B cell activation, as it links innate and adaptive immunity, promoting potent B cell responses. Indeed, rRABV-mBAFF induced a faster, higher antibody response in mice and enhanced survivorship in PEP settings compared to rRABV. Interestingly, rRABV-mBAFF and rRABV induced equivalent numbers of GC B cells, suggesting that rRABV-mBAFF augmented the extrafollicular B cell pathway. To confirm that rRABV-mBAFF modulated the extrafollicular pathway, we used a signaling lymphocytic activation molecule (SLAM)-associated protein (SAP)-deficient mouse model. In response to antigen, SAP-deficient mice form extrafollicular B cell responses but do not generate GCs. rRABV-mBAFF induced similar anti-RABV antibody responses in SAP-deficient and wild-type mice, demonstrating that BAFF modulated immunity through the extrafollicular and not the GC B cell pathway. Collectively, strategies that manipulate pathways of B cell activation may facilitate the development of a single-dose RABV vaccine that replaces current complicated and costly RABV PEP.IMPORTANCE Effective RABV PEP is currently resource- and cost-prohibitive in regions of the world where RABV is most prevalent. In order to diminish the requirements for

  6. Coxsackievirus B3 Directly Induced Th17 Cell Differentiation by Inhibiting Nup98 Expression in Patients with Acute Viral Myocarditis

    PubMed Central

    Long, Qi; Liao, Yu-Hua; Xie, Yu; Liang, Wei; Cheng, Xiang; Yuan, Jing; Yu, Miao

    2016-01-01

    Th17 cells play a key role in the progression of coxsackievirus B3 (CVB3)-induced acute viral myocarditis (AVMC). However, the direct effect of virus on Th17 cell differentiation is still unknown. Recently, nucleoporin (Nup) 98 has been proved to be associated with lymphocyte differentiation. Therefore, we investigated whether Nup98 mediated Th17 cell differentiation in AVMC. In our study, patients with AVMC and healthy controls were recruited. The results showed that CVB3 could enter into the CD4+ T cells in AVMC patients and healthy controls. After transfecting purified CD4+ T cells with CVB3 in vitro, the Th17 cell frequency, IL-17 secretion, and RORγT synthesis were increased while the Nup98 levels were decreased. Furthermore, down-regulating Nup98 expression by siRNA-Nup98 in CD4+ T cells resulted in the elevated Th17 cell frequency and IL-17 secretion, along with enhanced levels of RORγT, dissociative p300/CBP, and acetylated Stat3. Up-regulation of Nup98 expression by pcDNA3.1-Nup98 showed the opposite effects. Our results suggested that CVB3 directly induced CD4+ T cell differentiation into Th17 cells by inhibiting Nup98 expression, representing a therapeutic target in AVMC. PMID:28018858

  7. p-Hydroxylcinnamaldehyde induces the differentiation of oesophageal carcinoma cells via the cAMP-RhoA-MAPK signalling pathway

    PubMed Central

    Ma, Ming; Zhao, Lian-mei; Yang, Xing-xiao; Shan, Ya-nan; Cui, Wen-xuan; Chen, Liang; Shan, Bao-en

    2016-01-01

    p-Hydroxylcinnamaldehyde (CMSP) has been identified as an inhibitor of the growth of various cancer cells. However, its function in oesophageal squamous cell carcinoma (ESCC) and the underlying mechanism remain unclear. The aim of the present study was to characterize the differentiation effects of CMSP, as well as its mechanism in the differentiation of ESCC Kyse30 and TE-13 cells. The function of CMSP in the viability, colony formation, migration and invasion of Kyse30 and TE-13 cells was determined by MTS, colony-formation, wound healing and transwell assays. Western blotting and pull-down assays were used to investigate the effect of CMSP on the expression level of malignant markers of ESCC, as well as the activity of MAPKs, RhoA and GTP-RhoA in Kyse30 and TE-13 cells. We found that CMSP could inhibit proliferation and migration and induce Kyse30 and TE-13 cell differentiation, characterized by dendrite-like outgrowth, decreased expression of tumour-associated antigens, as well as the decreased expression of malignant markers. Furthermore, increased cAMP, p-P38 and decreased activities of ERK, JNK and GTP-RhoA, were detected after treatment with CMSP. These results indicated that CMSP induced the differentiation of Kyse30 and TE-13 cells through mediating the cAMP-RhoA-MAPK axis, which might provide new potential strategies for ESCC treatment. PMID:27501997

  8. 3-methylcholanthrene induces differential recruitment of aryl hydrocarbon receptor to human promoters.

    PubMed

    Pansoy, Andrea; Ahmed, Shaimaa; Valen, Eivind; Sandelin, Albin; Matthews, Jason

    2010-09-01

    The aryl hydrocarbon receptor (AHR) is a ligand-activated protein that mediates the toxic actions of polycyclic aromatic and halogenated compounds. Identifying genes directly regulated by AHR is important in understanding the pathways regulated by this receptor. Here we used the techniques of chromatin immunoprecipitation and DNA microarrays (ChIP-chip) to detect AHR-bound genomic regions after 3-methylcholanthrene (3MC) treatment of T-47D human breast cancer cells. We identified 241 AHR-3MC-bound regions, and transcription factor-binding site analysis revealed a strong overrepresentation of the AHR-responsive element. Conventional ChIP confirmed recruitment of AHR to 26 regions with target gene responses to 3MC varying from activation to inhibition to having no effect. A comparison of identified AHR-3MC-bound regions with AHR-2,3,7,8-tetrchlorodibenzo-p-dioxin (TCDD)-bound regions from our previous study (Ahmed, S., Valen, E., Sandelin, A., and Matthews, J. (2009). Toxicol. Sci. 111, 254-266) revealed that 127 regions were common between the data sets. Time course ChIPs for six of the regions showed that 3MC induced gene-specific changes in histone H3 acetylation and methylation and induced differential oscillatory binding of AHR, with a periodicity between 1.5 and 2 h. Re-treatment of cells with 3MC failed to alter the oscillatory binding profiles of AHR or aryl hydrocarbon receptor nuclear translocator. Cells became responsive to 3MC but not TCDD after 24 h of exposure to 3MC, highlighting important differences in AHR responsiveness between the two ligands. Our results reveal a number of novel AHR-bound promoter regions and target genes that exhibit differential kinetic binding profiles and regulation by AHR.

  9. Polar/apolar chemical inducers of differentiation of transformed cells: strategies to improve therapeutic potential.

    PubMed Central

    Marks, P A; Breslow, R; Rifkind, R A; Ngo, L; Singh, R

    1989-01-01

    N,N'-Hexamethylenebisacetamide (HMBA) induces transformed cells to differentiate, accompanied by suppression of oncogenicity. Clinical trials have shown that HMBA can cause positive therapeutic responses in some cancer patients, but clinical efficacy may be limited, in part, by dose-related toxicity. Potential improvements in efficacy may be accomplished by changes in the chemical structure of inducing agents and by increasing the sensitivity of tumor cells to inducers of differentiation. We have previously described an approach to improving tumor cell responsiveness to inducing agents. Transformed cell lines that have acquired low levels of resistance to vincristine display a markedly increased sensitivity to HMBA. We now report on a series of hybrid polar/apolar compounds--some of which are as active as HMBA and several of which are significantly more active than HMBA in vitro--whose chemical structures make it likely that they have different pharmacokinetics. Vincristine-resistant murine erythroleukemia cells also are shown to have marked increased sensitivity to these hybrid polar/apolar compounds. Thus these findings suggest potentially useful strategies for the application of polar/apolar inducers of differentiation to the treatment of cancers. These studies also provide approaches to further understanding of the biological process of terminal differentiation. PMID:2762329

  10. Differential roles of hydrogen peroxide and hydroxyl radical in cisplatin-induced cell death in renal proximal tubular epithelial cells.

    PubMed

    Baek, Su Mi; Kwon, Chae Hwa; Kim, Jae Ho; Woo, Jae Suk; Jung, Jin Sup; Kim, Yong Keun

    2003-09-01

    Reactive oxygen species (ROS) have been suggested as important mediators of cisplatin-induced acute renal failure in vivo. However, our previous studies have shown that cisplatin-induced cell death in vitro could not be prevented by scavengers of hydrogen peroxide and hydroxyl radical in rabbit renal cortical slices. This discrepancy may be attributed to differential roles of ROS in necrotic and apoptotic cell death. We therefore examined, in this study, the roles of ROS in necrosis and apoptosis induced by cisplatin in primary cultured rabbit proximal tubule. Cisplatin induced necrosis at high concentrations over a few hours and apoptosis at much lower concentrations over longer periods. Necrosis induced by high concentration of cisplatin was prevented by a cell-permeable superoxide scavenger (tiron), hydrogen peroxide scavengers (catalase and pyruvate), and antioxidants (Trolox and deferoxamine), whereas hydroxyl radical scavengers (dimethythiourea and thiourea) did not affect the cisplatin-induced necrosis. However, apoptosis induced by lower concentration of cisplatin was partially prevented by tiron and hydroxyl radical scavengers but not by hydrogen peroxide scavengers and antioxidants. Cisplatin-induced apoptosis was mediated by the signaling pathway that is associated with cytochrome c release from mitochondria and caspase-3 activation. These effects were prevented by tiron and dimethylthiourea but not by catalase. Dimethylthiourea produced a significant protection against cisplatin-induced acute renal failure, and the effect was associated with an inhibition of apoptosis. These results suggest that hydrogen peroxide is involved in the cisplatin-induced necrosis, whereas hydroxyl radical is responsible for the cisplatin-induced apoptosis. The protective effects of hydroxyl radical scavengers are associated with an inhibition of cytochrome c release and caspase activation.

  11. Differential Tomato Transcriptomic Responses Induced by Pepino Mosaic Virus Isolates with Differential Aggressiveness1[W][OA

    PubMed Central

    Hanssen, Inge M.; Peter van Esse, H.; Ballester, Ana-Rosa; Hogewoning, Sander W.; Parra, Nelia Ortega; Paeleman, Anneleen; Lievens, Bart; Bovy, Arnaud G.; Thomma, Bart P.H.J.

    2011-01-01

    Pepino mosaic virus (PepMV) is a highly infectious potexvirus and a major disease of greenhouse tomato (Solanum lycopersicum) crops worldwide. Damage and economic losses caused by PepMV vary greatly and can be attributed to differential symptomatology caused by different PepMV isolates. Here, we used a custom-designed Affymetrix tomato GeneChip array with probe sets to interrogate over 22,000 tomato transcripts to study transcriptional changes in response to inoculation of tomato seedlings with a mild and an aggressive PepMV isolate that share 99.4% nucleotide sequence identity. The two isolates induced a different transcriptomic response, despite accumulating to similar viral titers. PepMV inoculation resulted in repression of photosynthesis. In addition, defense responses were stronger upon inoculation with the aggressive isolate, in both cases mediated by salicylic acid signaling rather than by jasmonate signaling. Our results furthermore show that PepMV differentially regulates the RNA silencing pathway, suggesting a role for a PepMV-encoded silencing suppressor. Finally, perturbation of pigment biosynthesis, as shown by differential regulation of the flavonoid and lycopene biosynthesis pathways, was monitored. Metabolite analyses on mature fruits of PepMV-infected tomato plants, which showed typical fruit marbling, revealed a decrease in carotenoids, likely responsible for the marbled phenotype, and an increase in alkaloids and phenylpropanoids that are associated with pathogen defense in the yellow sectors of the fruit. PMID:21427280

  12. Sorafenib inhibition of Mcl-1 accelerates ATRA induced apoptosis in differentiation responsive AML cells

    PubMed Central

    Wang, Rui; Xia, Lijuan; Gabrilove, Janice; Waxman, Samuel; Jing, Yongkui

    2015-01-01

    Purpose All trans retinoic acid (ATRA) is successful in treating acute promyelocytic leukemia (APL) by inducing terminal differentiation-mediated cell death, but it has limited activity in non-APL acute myeloid leukemia (AML). We aim to improve ATRA therapy of AML by enhancing apoptosis through repression of the anti-apoptotic proteins Bcl-2 and Mcl-1. Experimental Design APL and AML cell lines, as well as primary AML samples, were used to explore the mechanisms regulating differentiation and apoptosis during ATRA treatment. Stable transfection and gene silencing with siRNA were used to identify the key factors that inhibit apoptosis during induction of differentiation and drugs that accelerate apoptosis. Results In differentiation responsive AML cells, ATRA treatment induces long-lasting repression of Bcl-2 while first up-modulating and then reducing the Mcl-1 level. The Mcl-1 level appears to serve as a gatekeeper between differentiation and apoptosis. During differentiation induction, activation of MEK/ERK and PI3K/Akt pathways by ATRA leads to activation of p90RSK and inactivation of glycogen synthase kinase 3β (GSK3β), which increase Mcl-1 levels by increasing its translation and stability. Sorafenib blocks ATRA-induced Mcl-1 increase by reversing p90RSK activation and GSK3β inactivation, maintains the repressed Bcl-2 level, and enhances ATRA induced apoptosis in non-APL AML cell lines and in primary AML cells. Conclusion Inhibition of Mcl-1 is required for apoptosis induction in ATRA differentiation responsive AML cells. ATRA and Sorafenib can be developed as a novel drug combination therapy for AML patients because this drug combination augments apoptosis by inhibiting Bcl-2 and Mcl-1. PMID:26459180

  13. Co-stimulation with bone morphogenetic protein-9 and FK506 induces remarkable osteoblastic differentiation in rat dedifferentiated fat cells.

    PubMed

    Nakamura, Toshiaki; Shinohara, Yukiya; Momozaki, Sawako; Yoshimoto, Takehiko; Noguchi, Kazuyuki

    2013-10-18

    Dedifferentiated fat (DFAT) cells, which are isolated from mature adipocytes using the ceiling culture method, exhibit similar characteristics to mesenchymal stem cells, and possess adipogenic, osteogenic, chondrogenic, and myogenic potentials. Bone morphogenetic protein (BMP)-2 and -9, members of the transforming growth factor-β superfamily, exhibit the most potent osteogenic activity of this growth factor family. However, the effects of BMP-2 and BMP-9 on the osteogenic differentiation of DFAT remain unknown. Here, we examined the effects of BMP-2 and BMP-9 on osteoblastic differentiation of rat DFAT (rDFAT) cells in the presence or absence of FK506, an immunosuppressive agent. Co-stimulation with BMP-9 and FK506 induced gene expression of runx2, osterix, and bone sialoprotein, and ALP activity compared with BMP-9 alone, BMP-2 alone and BMP-2+FK506 in rDFAT cells. Furthermore, it caused mineralization of cultures and phosphorylation of smad1/5/8, compared with BMP-9 alone. The ALP activity induced by BMP-9+FK506 was not influenced by addition of noggin, a BMP antagonist. Our data suggest that the combination of BMP-9 and FK506 potently induces osteoblastic differentiation of rDFAT cells.

  14. BMP4 Cooperates with Retinoic Acid to Induce the Expression of Differentiation Markers in Cultured Mouse Spermatogonia.

    PubMed

    Yang, Yongguang; Feng, Yanmin; Feng, Xue; Liao, Shangying; Wang, Xiuxia; Gan, Haiyun; Wang, Lixian; Lin, Xiwen; Han, Chunsheng

    2016-01-01

    Spermatogenesis is sustained by the proliferation and differentiation of spermatogonial stem cells (SSCs). However, the molecules controlling these processes remain largely unknown. Here, we developed a simplified high concentration serum-containing system for the culture of mouse SSCs. Analysis of SSCs markers and transplantation results revealed that the cultured spermatogonia retained stem cell characteristics after long-term in vitro propagation. Using this culture system, the expression and function of bone morphogenetic protein 4 (BMP4) were explored. Immunostaining showed that BMP4 was predominantly expressed in germ cells and that its level increased as spermatogenesis progresses. BMP4 receptors BMPR1A and BMPRII were present in spermatogonia, spermatocytes, and round spermatids. Moreover, despite the mRNAs of these two genes being present in mouse Sertoli cells, only BMPRII was detected by using Western blotting assays. While exogenous BMP4 by itself did not induce the expression of Stra8 and c-Kit, two marker genes of differentiating spermatogonia, a significant cooperative effect of BMP4 and retinoic acid (RA) was observed. Moreover, pretreatment of cultured spermatogonia with the BMP4 antagonist Noggin could inhibit RA-induced expression of these two marker genes. In conclusion, BMP4 may exert autocrine effects and act cooperatively with RA to induce the differentiation of spermatogonia in vivo.

  15. BMP4 Cooperates with Retinoic Acid to Induce the Expression of Differentiation Markers in Cultured Mouse Spermatogonia

    PubMed Central

    Feng, Yanmin; Feng, Xue; Wang, Xiuxia; Gan, Haiyun; Wang, Lixian; Lin, Xiwen

    2016-01-01

    Spermatogenesis is sustained by the proliferation and differentiation of spermatogonial stem cells (SSCs). However, the molecules controlling these processes remain largely unknown. Here, we developed a simplified high concentration serum-containing system for the culture of mouse SSCs. Analysis of SSCs markers and transplantation results revealed that the cultured spermatogonia retained stem cell characteristics after long-term in vitro propagation. Using this culture system, the expression and function of bone morphogenetic protein 4 (BMP4) were explored. Immunostaining showed that BMP4 was predominantly expressed in germ cells and that its level increased as spermatogenesis progresses. BMP4 receptors BMPR1A and BMPRII were present in spermatogonia, spermatocytes, and round spermatids. Moreover, despite the mRNAs of these two genes being present in mouse Sertoli cells, only BMPRII was detected by using Western blotting assays. While exogenous BMP4 by itself did not induce the expression of Stra8 and c-Kit, two marker genes of differentiating spermatogonia, a significant cooperative effect of BMP4 and retinoic acid (RA) was observed. Moreover, pretreatment of cultured spermatogonia with the BMP4 antagonist Noggin could inhibit RA-induced expression of these two marker genes. In conclusion, BMP4 may exert autocrine effects and act cooperatively with RA to induce the differentiation of spermatogonia in vivo. PMID:27795714

  16. Celastrol inhibits lung infiltration in differential syndrome animal models by reducing TNF-α and ICAM-1 levels while preserving differentiation in ATRA-induced acute promyelocytic leukemia cells.

    PubMed

    Xu, Li-min; Zheng, Yue-juan; Wang, Ying; Yang, Yang; Cao, Fan-fan; Peng, Bin; Xu, Xiong-fei; An, Hua-zhang; Zheng, Ao-xiang; Zhang, Deng-hai; Uzan, Georges; Yu, Yi-zhi

    2014-01-01

    All-trans retinoic acid (ATRA) is a revolutionary agent for acute promyelocytic leukemia (APL) treatment via differentiation induction. However, ATRA treatment also increases cytokine, chemokine, and adhesive molecule (mainly ICAM-1) expression, which can cause clinical complications, including a severe situation known as differentiation syndrome (DS) which can cause death. Therefore, it is of clinical significance to find a strategy to specifically blunt inflammatory effects while preserving differentiation. Here we report that the natural compound, celastrol, could effectively block lung infiltrations in DS animal models created by loading ATRA-induced APL cell line NB4. In ATRA-treated NB4 cells, celastrol could potently inhibit ICAM-1 elevation and partially reduce TNF-α and IL-1β secretion, though treatment showed no effects on IL-8 and MCP-1 levels. Celastrol's effect on ICAM-1 in ATRA-treated NB4 was related to reducing MEK1/ERK1 activation. Strikingly and encouragingly, celastrol showed no obvious effects on ATRA-induced NB4 differentiation, as determined by morphology, enzymes, and surface markers. Our results show that celastrol is a promising and unique agent for managing the side effects of ATRA application on APL, and suggest that hyper-inflammatory ability is accompanied by, but not necessary for, APL differentiation. Thus we offered an encouraging novel strategy to further improve differentiation therapy.

  17. Differential Effect of Plant Lipids on Membrane Organization

    PubMed Central

    Grosjean, Kevin; Mongrand, Sébastien; Beney, Laurent; Simon-Plas, Françoise; Gerbeau-Pissot, Patricia

    2015-01-01

    The high diversity of the plant lipid mixture raises the question of their respective involvement in the definition of membrane organization. This is particularly the case for plant plasma membrane, which is enriched in specific lipids, such as free and conjugated forms of phytosterols and typical phytosphingolipids, such as glycosylinositolphosphoceramides. This question was here addressed extensively by characterizing the order level of membrane from vesicles prepared using various plant lipid mixtures and labeled with an environment-sensitive probe. Fluorescence spectroscopy experiments showed that among major phytosterols, campesterol exhibits a stronger ability than β-sitosterol and stigmasterol to order model membranes. Multispectral confocal microscopy, allowing spatial analysis of membrane organization, demonstrated accordingly the strong ability of campesterol to promote ordered domain formation and to organize their spatial distribution at the membrane surface. Conjugated sterol forms, alone and in synergy with free sterols, exhibit a striking ability to order membrane. Plant sphingolipids, particularly glycosylinositolphosphoceramides, enhanced the sterol-induced ordering effect, emphasizing the formation and increasing the size of sterol-dependent ordered domains. Altogether, our results support a differential involvement of free and conjugated phytosterols in the formation of ordered domains and suggest that the diversity of plant lipids, allowing various local combinations of lipid species, could be a major contributor to membrane organization in particular through the formation of sphingolipid-sterol interacting domains. PMID:25575593

  18. BMP4-induced differentiation of a rat spermatogonial stem cell line causes changes in its cell adhesion properties.

    PubMed

    Carlomagno, Gianfranco; van Bragt, Maaike P A; Korver, Cindy M; Repping, Sjoerd; de Rooij, Dirk G; van Pelt, Ans M M

    2010-11-01

    Spermatogonial stem cells (SSCs) are at the basis of the spermatogenic process and are essential for the continuous lifelong production of spermatozoa. Although several factors that govern SSC self-renewal and differentiation have been investigated, the direct effect of such factors on SSCs has not yet been studied, mainly because of the absence of markers to identify SSCs and the lack of effective methods to obtain and culture a pure population of SSCs. We now have used a previously established rat SSC cell line (GC-6spg) to elucidate the role of BMP4 in SSC differentiation. We found that GC-6spg cells cultured in the presence of BMP4 upregulate KIT expression, which is an early marker for differentiating spermatogonia. GC-6spg cells were found to express three BMP4 receptors and the downstream SMAD1/5/8 proteins were phosphorylated during BMP4-induced differentiation. A time-course DNA micro-array analysis revealed a total of 529 differentially regulated transcripts (≥2-fold), including several known downstream targets of BMP4 such as Id2 and Gata2. Pathway analysis revealed that the most affected pathways were those involved in adherens junctions, focal junctions, gap junctions, cell adhesion molecules, and regulation of actin cytoskeleton. Interestingly, among the genes belonging to the most strongly affected adhesion pathways was Cdh1 (known as E-cadherin), an adhesion molecule known to be expressed by a subpopulation of spermatogonia including SSCs. Overall, our results suggest that BMP4 induces early differentiation of SSCs in a direct manner by affecting cell adhesion pathways.

  19. Lapatinib induces autophagic cell death and differentiation in acute myeloblastic leukemia

    PubMed Central

    Chen, Yu-Jen; Fang, Li-Wen; Su, Wen-Chi; Hsu, Wen-Yi; Yang, Kai-Chien; Huang, Huey-Lan

    2016-01-01

    Lapatinib is an oral-form dual tyrosine kinase inhibitor of epidermal growth factor receptor (EGFR or ErbB/Her) superfamily members with anticancer activity. In this study, we examined the effects and mechanism of action of lapatinib on several human leukemia cells lines, including acute myeloid leukemia (AML), chronic myeloid leukemia (CML), and acute lymphoblastic leukemia (ALL) cells. We found that lapatinib inhibited the growth of human AML U937, HL-60, NB4, CML KU812, MEG-01, and ALL Jurkat T cells. Among these leukemia cell lines, lapatinib induced apoptosis in HL-60, NB4, and Jurkat cells, but induced nonapoptotic cell death in U937, K562, and MEG-01 cells. Moreover, lapatinib treatment caused autophagic cell death as shown by positive acridine orange staining, the massive formation of vacuoles as seen by electronic microscopy, and the upregulation of LC3-II, ATG5, and ATG7 in AML U937 cells. Furthermore, autophagy inhibitor 3-methyladenine and knockdown of ATG5, ATG7, and Beclin-1 using short hairpin RNA (shRNA) partially rescued lapatinib-induced cell death. In addition, the induction of phagocytosis and ROS production as well as the upregulation of surface markers CD14 and CD68 was detected in lapatinib-treated U937 cells, suggesting the induction of macrophagic differentiation in AML U937 cells by lapatinib. We also noted the synergistic effects of the use of lapatinib and cytotoxic drugs in U937 leukemia cells. These results indicate that lapatinib may have potential for development as a novel antileukemia agent. PMID:27499639

  20. Differential microbial transformation of nitrosamines by an inducible propane monooxygenase.

    PubMed

    Homme, Carissa L; Sharp, Jonathan O

    2013-07-02

    The toxicity of N-nitrosamines, their presence in drinking and environmental water supplies, and poorly understood recalcitrance collectively necessitate a better understanding of their potential for bioattenuation. Here, we show that the bacterial strain Rhodococcus jostii RHA1 can biotransform N-nitrosodiethylamine (NDEA), N-nitrosodi-n-propylamine (NDPA), N-nitrosopyrrolidine (NPYR), and possibly N-nitrosomorpholine (NMOR) in addition to N-nitrosodimethylamine (NDMA). Growth of cells on propane as the sole carbon source greatly enhanced degradation rates when contrasted with cells grown on complex organics. Propane-induced rates in order of fastest to slowest were NDMA > NDEA > NDPA > NPYR > NMOR at concentrations <2000 μg/L. Removal rates for linear functional groups scaled inversely with mass and cyclic nitrosamines were more recalcitrant than linear nitrosamines. Controls demonstrated significant NDEA and NDPA losses independent of biomass, suggesting abiotic processes may play a role in attenuation of these two compounds under experimental conditions tested here. In contrast to NDMA, a transition from first to zero order kinetics was not observed for the other nitrosamines included in this study over a concentration range of 20-2000 μg/L. A genetic knockout for the propane monooxygenase enzyme (PrMO) confirmed the role of this enzyme in the biotransformation of NDEA and NPYR. This study furthers our understanding of environmental nitrosamine attenuation by revealing an enzymatic mechanism for the biotransformation of multiple nitrosamines, their relative recalcitrance to transformation, and potential for abiotic loss.

  1. Knockdown of SALL4 Protein Enhances All-trans Retinoic Acid-induced Cellular Differentiation in Acute Myeloid Leukemia Cells*

    PubMed Central

    Liu, Li; Liu, Liang; Leung, Lai-Han; Cooney, Austin J.; Chen, Changyi; Rosengart, Todd K.; Ma, Yupo; Yang, Jianchang

    2015-01-01

    All-trans retinoic acid (ATRA) is a differentiation agent that revolutionized the treatment of acute promyelocytic leukemia. However, it has not been useful for other types of acute myeloid leukemia (AML). Here we explored the effect of SALL4, a stem cell factor, on ATRA-induced AML differentiation in both ATRA-sensitive and ATRA-resistant AML cells. Aberrant SALL4 expression has been found in nearly all human AML cases, whereas, in normal bone marrow and peripheral blood cells, its expression is only restricted to hematopoietic stem/progenitor cells. We reason that, in AMLs, SALL4 activation may prevent cell differentiation and/or protect self-renewal that is seen in normal hematopoietic stem/progenitor cells. Indeed, our studies show that ATRA-mediated myeloid differentiation can be largely blocked by exogenous expression of SALL4, whereas ATRA plus SALL4 knockdown causes significantly increased AML differentiation and cell death. Mechanistic studies indicate that SALL4 directly associates with retinoic acid receptor α and modulates ATRA target gene expression. SALL4 is shown to recruit lysine-specific histone demethylase 1 (LSD1) to target genes and alter the histone methylation status. Furthermore, coinhibition of LSD1 and SALL4 plus ATRA treatment exhibited the strongest anti-AML effect. These findings suggest that SALL4 plays an unfavorable role in ATRA-based regimes, highlighting an important aspect of leukemia therapy. PMID:25737450

  2. Polydatin, a natural precursor of resveratrol, induces cell cycle arrest and differentiation of human colorectal Caco-2 cell

    PubMed Central

    2013-01-01

    Background Human colon adenocarcinoma cells are resistant to chemotherapeutic agents, such as anthracyclines, that induce death by increasing the reactive oxygen species. A number of studies have been focused on chemo-preventive use of resveratrol as antioxidant against cardiovascular diseases, aging and cancer. While resveratrol cytotoxic action was due to its pro-oxidant properties. In this study, we investigate whether the Resveratrol (trans-3,5,49-trihydroxystilbene) and its natural precursor Polydatin (resveratrol-3-O-b-mono- D-glucoside, the glycoside form of resveratrol) combination, might have a cooperative antitumor effect on either growing or differentiated human adenocarcinoma colon cancer cells. Methods The polydatin and resveratrol pharmacological interaction was evaluated in vitro on growing and differentiated Caco-2 cell lines by median drug effect analysis calculating a combination index with CalcuSyn software. We have selected a synergistic combination and we have evaluated its effect on the biological and molecular mechanisms of cell death. Results Simultaneous exposure to polydatin and resveratrol produced synergistic antiproliferative effects compared with single compound treatment. We demonstrated that polydatin alone or in combination with resveratrol at 3:1 molar ratio synergistically modulated oxidative stress, cell cycle, differentiation and apoptosis. Worthy of note treatment with polydatin induced a nuclear localization and decreased expression of heat shock protein 27, and vimentin redistributed within the cell. Conclusions From morphological, and biochemical outcome we obtained evidences that polydatin induced a transition from a proliferative morphology to cell-specific differentiated structures and caused human CaCo-2 cell death by induction of apoptosis. Our data suggest the potential use of polydatin in combination chemotherapy for human colon cancer. PMID:24138806

  3. Differential inhibitory effects of 2-azafluorenones on PI-PLC activation but not on PC-PLC- or PC-PLD-activation induced by histamine, PAF, PMA or A23187 in C6 glioma cells.

    PubMed

    Wang, Hai-Long; Wang, Li-Chuan; Wei, Jiann-Wu

    2013-02-28

    In this study, C6 glioma cells were used to test the effects of 2-azafluorenone and its related compounds on membrane phosphatidylinositol (PI) and phosphatidylcholine (PC) turnover. An increase of [³H]-labeled inositol phosphate (IP1) formation by histamine (100 μM) or A23187 (100 nM) via the activation of phosphatidylinositol-specific phospholipase C (PI-PLC) to breakdown labeled substrate was observed, and this effect could be partially blocked by about half at 100 μM of 2-azafluorenones. Histamine induced the increase of IP1 formation, but failed to cause an increase in extracellularly releasing of [3H]choline metabolites, or intracellular accumulation of [³H]phosphscholine. However, platelet activation factor (PAF) from 0.2 to 1 μM, and phorbol 12-myristate-13-acetate (PMA) at 1 μM caused an increase in extracellularly releasing of [³H]choline metabolites, and intracellular accumulation of [³H]phosphocholine via the activation on phosphatidylcholine (PC)-PLC. These responses of PAF and PMA were not affected by 2-azafluorenone or 4-methyl-2-azafluorenone even at high concentration (10⁻⁴ M). A23187 induced an increase of intracellular [³H]choline release via the activation of PCphospholipase D (PLD). This increasing effect of 100 nM A23187 was not affected by 2-azafluorenone or 4-methyl-2-azafluorenone even at a high concentration of 10⁻⁴ M. In summary, the inhibitory effect of 2-azafluorenone and its related compound 4-methyl-2-azafluorenone was observed selectively on PIPLC, but not on PC-PLC or PC-PLD based on changes of products after the activation of these enzymes.

  4. Propulsion Induced Effects Test Program

    NASA Technical Reports Server (NTRS)

    Cappuccio, Gelsomina; Won, Mark; Bencze, Dan

    1999-01-01

    The objective of this milestone is to assess the propulsion/airframe integration characteristics of the Technology Concept Airplane and design variations through computational analysis and experimental subsonic through supersonic wind tunnel testing. The Milestone will generate a comprehensive CFD and wind tunnel data base of the baseline, and design variations. Emphasis will be placed on establishing the propulsion induced effects on the flight performance of the Technology Concept Airplane with all appropriate wind tunnel corrections.

  5. Ram ion scattering caused by Space Shuttle v x B induced differential charging

    NASA Technical Reports Server (NTRS)

    Katz, I.; Davis, V. A.

    1987-01-01

    Observations of secondary, high-inclination ions streams have been reported in the literature. The authors of these previous papers attributed the source of the secondary ions to a disturbed region in the plasma about 10 m from the Space Shuttle Orbiter. A new theory has been developed which shows how v x B induced differential charging on the plasma diagnostics package (PDP) can scatter the ram ion flux. Some of these ions are reflected back to the PDP and may be the sorce of the observed ion distributions. The effect is unique to large spacecraft; it occurs only when the magnitude of the induced v x B potentials are much larger than the electron thermal energy and of the order of the ion ram energy. That the ion streams observed at large angles must have been reflected from the PDP surface is demonstrated with three-dimensional sheath and particle trajectory calculations using the low earth orbit version of the NASA Charging Analyzer Program (NASCAP/LEO).

  6. Granzymes A and K differentially potentiate LPS-induced cytokine response

    PubMed Central

    Wensink, Annette C; Kok, Helena M; Meeldijk, Jan; Fermie, Job; Froelich, Christopher J; Hack, C Erik; Bovenschen, Niels

    2016-01-01

    Granzymes are serine proteases that, upon release from cytotoxic cells, induce apoptosis in tumor cells and virally infected cells. In addition, a role of granzymes in inflammation is emerging. Recently, we have demonstrated that extracellular granzyme K (GrK) potentiates lipopolysaccharide (LPS)-induced cytokine response from monocytes. GrK interacts with LPS, disaggregates LPS micelles, and stimulates LPS-CD14 binding and Toll-like receptor signaling. Here we show that human GrA also potentiates cytokine responses in human monocytes initiated by LPS or Gram-negative bacteria. Similar to GrK, this effect is independent of GrA catalytic activity. Unlike GrK, however, GrA does not bind to LPS, has little influence on LPS micelle disaggregation, and does not augment LPS-CD14 complex formation. We conclude that GrA and GrK differentially modulate LPS-Toll-like receptor signaling in monocytes, suggesting functional redundancy among cytotoxic lymphocyte proteases in the anti-bacterial innate immune response. PMID:28028441

  7. Triptolide Inhibited Cytotoxicity of Differentiated PC12 Cells Induced by Amyloid-Beta25–35 via the Autophagy Pathway

    PubMed Central

    Xu, Pengjuan; Li, Zhigui; Wang, Hui; Zhang, Xiaochen; Yang, Zhuo

    2015-01-01

    Evidence shows that an abnormal deposition of amyloid beta-peptide25–35 (Aβ25–35) was the primary cause of the pathogenesis of Alzheimer’s disease (AD). And the elimination of Aβ25–35 is considered an important target for the treatment of AD. Triptolide (TP), isolated from Tripterygium wilfordii Hook.f. (TWHF), has been shown to possess a broad spectrum of biological profiles, including neurotrophic and neuroprotective effects. In our study investigating the effect and potential mechanism of triptolide on cytotoxicity of differentiated rat pheochromocytoma cell line (the PC12 cell line is often used as a neuronal developmental model) induced by Amyloid-Beta25–35 (Aβ25–35), we used 3-(4, 5-dimethylthiazol-2-yl)-2, 5- diphenyltetrazolium bromide (MTT) assay, flow cytometry, Western blot, and acridine orange staining to detect whether triptolide could inhibit Aβ25–35–induced cell apoptosis. We focused on the potential role of the autophagy pathway in Aβ25–35-treated differentiated PC12 cells. Our experiments show that cell viability is significantly decreased, and the apoptosis increased in Aβ25–35-treated differentiated PC12 cells. Meanwhile, Aβ25–35 treatment increased the expression of microtubule-associated protein light chain 3 II (LC3 II), which indicates an activation of autophagy. However, triptolide could protect differentiated PC12 cells against Aβ25–35-induced cytotoxicity and attenuate Aβ25–35-induced differentiated PC12 cell apoptosis. Triptolide could also suppress the level of autophagy. In order to assess the effect of autophagy on the protective effects of triptolide in differentiated PC12 cells treated with Aβ25–35, we used 3-Methyladenine (3-MA, an autophagy inhibitor) and rapamycin (an autophagy activator). MTT assay showed that 3-MA elevated cell viability compared with the Aβ25–35-treated group and rapamycin inhibits the protection of triptolide. These results suggest that triptolide will repair the

  8. Expression of osterix inhibits bone morphogenetic protein-induced chondrogenic differentiation of mesenchymal progenitor cells.

    PubMed

    Tominaga, Hiroyuki; Maeda, Shingo; Miyoshi, Hiroyuki; Miyazono, Kohei; Komiya, Setsuro; Imamura, Takeshi

    2009-01-01

    Osteoblasts and chondrocytes arise from common bipotential mesenchymal progenitor cells. Although the differentiation of these two cell lineages can be induced by treatment with bone morphogenetic proteins (BMPs), the responses of mesenchymal progenitors to BMP differ from cell line to cell line. Here we demonstrate that C3H/10T1/2 cells preferred chondrogenic differentiation, primary bone marrow stroma cells (MSCs) tended to convert to osteoblasts, and ST-2 cells differentiated into both the osteoblastic and chondrocytic lineages simultaneously, suggesting that a molecular switch functions to select cell fate. Osterix, the secondary master regulator of osteoblastogenesis, was induced by BMP at high and low levels in MSCs and ST-2 cells, respectively; in contrast, C3H/10T1/2 cells demonstrated only faint expression. As osterix has been suggested as a negative regulator of chondrogenesis, we hypothesized that the intense chondrocyte differentiation of C3H/10T1/2 cells may have resulted from an absence of osterix. We therefore restored osterix gene expression in C3H/10T1/2 cells using an adenovirus vector. Following BMP treatment, infection with an osterix-encoding virus dramatically inhibited the chondrocytic differentiation of C3H/10T1/2 cells, resulting instead in prominent osteoblast differentiation. These results indicate the chondrogenic potential of C3H/10T1/2 cells was abrogated by osterix expression. Chondrocyte differentiation of MSCs, however, was not enhanced by silencing the osterix gene using lentivirus-mediated shRNA, despite successful suppression of osteoblast differentiation. These results suggest that the low levels of osterix expression remaining after knockdown are sufficient to block chondrogenesis, whereas higher expression may be required to promote osteoblastic differentiation.

  9. Differentiation of human foreskin fibroblast-derived induced pluripotent stem cells into hepatocyte-like cells.

    PubMed

    Wang, Jianjun; Zhao, Ping; Wan, Zhihong; Jin, Xueyuan; Cheng, Yongqian; Yan, Tao; Qing, Song; Ding, Ning; Xin, Shaojie

    2016-10-01

    The aim of this study was to investigate the differentiation potential of induced pluripotent stem cells (iPSCs) derived from human foreskin fibroblasts (HFFs) into hepatocyte-like cells (HLCs). The iPSCs were firstly induced by transduction of OCT4, SOX2, KLF4, and c-MYC into HFFs using retrovirus. Afterwards, expressions of pluripotency factors were identified by semiquantitative reverse transcription-polymerase chain reaction and immunofluorescence staining, and karyotype, embryoid, and teratoma were observed by microscope. Then, iPSCs were gradually differentiated into endoderm cells, hepatic progenitor cells, and mature HLCs by special culture medium. During this process, differentiation efficiency into each kind of cells was evaluated by detecting SOX17, HNF4a, and ALB using flow cytometry, respectively. Besides, enzyme-linked immunosorbent assay was conducted to detect the secretion of ALB in iPSC-induced HLCs and quantitative reverse transcription-polymerase chain reaction was performed to detect the expression levels of hepatocyte-specific genes. The iPSCs were successfully induced by HFFs, which exhibited typical embryonic stem cells morphology, positive alkaline phosphatase staining, normal diploid karyotype, and positive expression of various pluripotency factors. Meanwhile, spherical embryoid and teratoma with 3 germ layers were formed by iPSCs. The iPSCs were consecutively induced into endoderm cells, hepatic progenitor cells and mature HLCs, and the differentiation efficiency was 55.7 ± 2.9%, 45.7 ± 4.8%, and 35.0 ± 3.9%, respectively. Besides, the secretion of ALB and expression of various hepatocyte-specific genes was highly detected in iPSC-induced HLCs. The iPSCs were successfully derived from HFFs and then differentiated into HLCs, which proved a new source for hepatocyte transplantation.

  10. Differential Sympathetic Vasomotor Activation Induced by Liver Cirrhosis in Rats

    PubMed Central

    Bergamaschi, Cássia T.; Campos, Ruy R.

    2016-01-01

    We tested the hypothesis that there is a topographical sympathetic activation in rats submitted to experimental cirrhosis. Baseline renal (rSNA) and splanchnic (sSNA) sympathetic nerve activities were evaluated in anesthetized rats. In addition, we evaluated main arterial pressure (MAP), heart rate (HR), and baroreceptor reflex sensitivity (BRS). Cirrhotic Wistar rats were obtained by bile duct ligation (BDL). MAP and HR were measured in conscious rats, and cardiac BRS was assessed by changes in blood pressure induced by increasing doses of phenylephrine or sodium nitroprusside. The BRS and baseline for the control of sSNA and rSNA were also evaluated in urethane-anesthetized rats. Cirrhotic rats had increased baseline sSNA (BDL, 102 vs control, 58 spikes/s; p<0.05), but no baseline changes in the rSNA compared to controls. These data were accompanied by increased splanchnic BRS (p<0.05) and decreased cardiac (p<0.05) and renal BRS (p<0.05). Furthermore, BDL rats had reduced basal MAP (BDL, 93 vs control, 101 mmHg; p<0.05) accompanied by increased HR (BDL, 378 vs control, 356; p<0.05). Our data have shown topographical sympathetic activation in rats submitted to experimental cirrhosis. The BDL group had increased baseline sSNA, independent of dysfunction in the BRS and no changes in baseline rSNA. However, an impairment of rSNA and HR control by arterial baroreceptor was noted. We suggest that arterial baroreceptor impairment of rSNA and HR is an early marker of cardiovascular dysfunction related to liver cirrhosis and probably a major mechanism leading to sympathoexcitation in decompensated phase. PMID:27055088

  11. Differentiated properties of hepatocytes induced from pancreatic cells.

    PubMed

    Tosh, David; Shen, Chia-Ning; Slack, Jonathan M W

    2002-09-01

    Transdifferentiation of pancreas to liver is a well-recognized phenomenon and has been described in animal experiments and human pathology. We recently produced an in vitro model for the transdifferentiation (or conversion) of the pancreatic cell line AR42J-B13 to hepatocytes based on culture with dexamethasone (Dex). To determine whether the hepatocytes express markers of hepatic intermediary metabolism and detoxification, we investigated the patterns of expression of glucokinase, cytochrome P450s CYP3A1 and CYP2B1/2, testosterone/4-nitrophenol uridine diphosphate glucuronosyltransferase (UDPGT), and aryl sulfotransferase. All were expressed. We also determined the expression of 2 enzymes involved in ammonia detoxification: carbamoylphosphate synthetase I (CPS I) and glutamine synthetase (GS). These enzymes are normally strictly compartmentalized in liver in a wide periportal pattern and the last downstream perivenous hepatocytes, respectively. Following culture with Dex, CPS I and GS are expressed in 2 different cell populations, suggesting that both periportal and perivenous hepatocytes are induced. We also produced a reporter assay based on the activation of green fluorescent protein (GFP) by the transthyretin (TTR) promoter or glucose-6-phosphatase (G6Pase) promoter. After culture with Dex, transfected cells begin to express GFP, showing that hepatic promoters are activated in concert with the induction of the hepatocyte phenotype. Lastly, we examined the stability of the hepatic phenotype and found that some cells still express liver markers (transferrin or albumin) up to 14 days after removal of Dex. In conclusion, these results suggest that pancreatic hepatocytes produced by this method may offer an alternative model to primary cultures of hepatocytes for the study of liver function.

  12. ATOH1 Can Regulate the Tumorigenicity of Gastric Cancer Cells by Inducing the Differentiation of Cancer Stem Cells

    PubMed Central

    Han, Myoung-Eun; Baek, Su-Jin; Kim, Seon-Young; Kang, Chi-Dug; Oh, Sae-Ock

    2015-01-01

    Cancer stem cells (CSCs) have been shown to mediate tumorigenicity, chemo-resistance, radio-resistance and metastasis, which suggest they be considered therapeutic targets. Because their differentiated daughter cells are no longer tumorigenic, to induce the differentiation of CSCs can be one of strategies which can eradicate CSCs. Here we show that ATOH1 can induce the differentiation of gastric cancer stem cells (GCSCs). Real time PCR and western blot analysis showed that ATOH1 was induced during the differentiation of GCSCs. Furthermore, the lentivirus-induced overexpression of ATOH1 in GCSCs and in gastric cancer cell lines significantly induced differentiation, reduced proliferation and sphere formation, and reduced in vivo tumor formation in the subcutaneous injection and liver metastasis xenograft models. These results suggest ATOH1 be considered for the development of a differentiation therapy for gastric cancer. PMID:25950549

  13. The mysterious human epidermal cell cycle, or an oncogene-induced differentiation checkpoint

    PubMed Central

    Gandarillas, Alberto

    2012-01-01

    Fifteen years ago, we reported that proto-oncogene MYC promoted differentiation of human epidermal stem cells, a finding that was surprising to the MYC and the skin research communities. MYC was one of the first human oncogenes identified, and it had been strongly associated with proliferation. However, it was later shown that MYC could induce apoptosis under low survival conditions. Currently, the notion that MYC promotes epidermal differentiation is widely accepted, but the cell cycle mechanisms that elicit this function remain unresolved. We have recently reported that keratinocytes respond to cell cycle deregulation and DNA damage by triggering terminal differentiation. This mechanism might constitute a homeostatic protection face to cell cycle insults. Here, I discuss recent and not-so-recent evidence suggesting the existence of a largely unexplored oncogene-induced differentiation response (OID) analogous to oncogene-induced apoptosis (OIA) or senescence (OIS). In addition, I propose a model for the role of the cell cycle in skin homeostasis maintenance and for the dual role of MYC in differentiation. PMID:23114621

  14. Interleukin 6 induces myeloid differentiation of a human biphenotypic leukemic cell line.

    PubMed

    Cohen, A; Petsche, D; Grunberger, T; Freedman, M H

    1992-08-01

    The human leukemic cell line B1, is characterized by a specific 4;11 chromosomal translocation, immature myeloid/pre-B biphenotypic features, expression of multiple cytokine receptors and IL-1-dependent autocrine growth regulation [Cohen et al. (1991) Blood 78, 94]. Exposure of B1 cells to low concentrations of IL-6 abolished the leukemic cells ability to form colonies in semi-solid medium and slowed down their proliferation rate in suspension. Associated with these changes in growth characteristics, the B1 cells differentiated along the myeloid lineage as judged by the induction of the myeloid-specific surface antigens CD33, CD13 and CD11b, as well as histochemical and morphological changes characteristic of myeloid cells. The induction of differentiation was specific to IL-6 since none of the other cytokines which inhibited B1 cell growth (IL-7, gamma IFN and TNF alpha) were able to induce myeloid or lymphoid differentiation in these cells. The IL-6-induced differentiation was completed over a two week period and was essentially irreversible. Together with the phenotypic changes, IL-6 induced the expression of the protein tyrosine phosphatase (CD45) which may be associated with altered growth observed in IL-6-treated cells. Induction of terminal differentiation of leukemic cells by recombinant bioregulators has therapeutic implications and merits further study.

  15. Nicotinamide induces differentiation of embryonic stem cells into insulin-secreting cells

    SciTech Connect

    Vaca, Pilar; Berna, Genoveva; Araujo, Raquel; Carneiro, Everardo M.; Bedoya, Francisco J.; Soria, Bernat; Martin, Franz

    2008-03-10

    The poly(ADP-ribose) polymerase (PARP) inhibitor, nicotinamide, induces differentiation and maturation of fetal pancreatic cells. In addition, we have previously reported evidence that nicotinamide increases the insulin content of cells differentiated from embryonic stem (ES) cells, but the possibility of nicotinamide acting as a differentiating agent on its own has never been completely explored. Islet cell differentiation was studied by: (i) X-gal staining after neomycin selection; (ii) BrdU studies; (iii) single and double immunohistochemistry for insulin, C-peptide and Glut-2; (iv) insulin and C-peptide content and secretion assays; and (v) transplantation of differentiated cells, under the kidney capsule, into streptozotocin (STZ)-diabetic mice. Here we show that undifferentiated mouse ES cells treated with nicotinamide: (i) showed an 80% decrease in cell proliferation; (ii) co-expressed insulin, C-peptide and Glut-2; (iii) had values of insulin and C-peptide corresponding to 10% of normal mouse islets; (iv) released insulin and C-peptide in response to stimulatory glucose concentrations; and (v) after transplantation into diabetic mice, normalized blood glucose levels over 7 weeks. Our data indicate that nicotinamide decreases ES cell proliferation and induces differentiation into insulin-secreting cells. Both aspects are very important when thinking about cell therapy for the treatment of diabetes based on ES cells.

  16. Antioxidant defense and apoptotic effectors in ascorbic acid and β-glycerophosphate-induced osteoblastic differentiation.

    PubMed

    Chaves Neto, Antonio Hernandes; Machado, Daisy; Yano, Cláudia Lumy; Ferreira, Carmen Veríssima

    2011-01-01

    MC3T3-E1 cells grown in the presence of ascorbic acid and β-glycerophosphate (AA/β-GP) express alkaline phosphatase and produce an extensive collagenous extracellular matrix. Differentiated MC3T3-E1 cells are more sensitive to hydrogen peroxide-induced oxidative stress than undifferentiated cells. In this study, we compared the profile of antioxidant enzymes and molecular markers of apoptosis in undifferentiated and differentiated MC3T3-E1 cells (cell differentiation was induced by treatment with AA/β-GP). Differentiated osteoblasts showed lower expression and activity of catalase, glutathione S-transferase and glutathione peroxidase. The total superoxide dismutase activity and the expression of Cu/Zn superoxide dismutase were also lower, while the expression of Mn superoxide dismutase was higher in differentiated osteoblasts. The level of malondialdehyde, a widely used marker for oxidative stress, was lower in the AA/β-GP group compared with control cells, but this difference was not significant. Western blotting showed that treatment with AA/β-GP increased the Bax/Bcl-2 ratio used as an index of cellular vulnerability to apoptosis. In addition, the activities of caspases 3, 8 and 9 and cleaved poly (ADP) ribose polymerase were significantly higher in differentiated cells. These findings provide new insights into how changes in the activities of major antioxidant enzymes and in the signaling pathways associated with apoptosis may influence the susceptibility of bone cells to oxidative stress.

  17. Differential Effects of Two T Group Styles

    ERIC Educational Resources Information Center

    Boller, Jon D.

    1974-01-01

    This article presents a rationale for examining the effects of the T group on introverts and extroverts. Results indicate that the sensory awareness group is more profitable to both personality types and that there is a direct relationship between personality type and profit in a T group. (Author)

  18. The Effect of Spaceflight on Cartilage Cell Cycle and Differentiation

    NASA Technical Reports Server (NTRS)

    Doty, Stephen B.; Stiner, Dalina; Telford, William G.

    2000-01-01

    In vivo studies have shown that spaceflight results in loss of bone and muscle. In an effort to understand the mechanisms of these changes, cell cultures of cartilage, bone and muscle have been subjected to spaceflight to study the microgravity effects on differentiated cells. However it now seems possible that the cell differentiation process itself may be the event(s) most affected by spaceflight. For example, osteoblast-like cells have been shown to have reduced cellular activity in microgravity due to an underdifferentiated state (Carmeliet, et al, 1997). And reduced human lymphocyte growth in spaceflight was related to increased apoptosis (Lewis, et al, 1998). Which brings us to the question of whether reduced cellular activity in space is due to an effect on the differentiated cell, an effect on the cell cycle and cell proliferation, or an effect on cell death. This question has not been specifically addressed on previous flights and was the question behind die present study.

  19. Involvement of the histamine H4 receptor in clozapine-induced hematopoietic toxicity: Vulnerability under granulocytic differentiation of HL-60 cells.

    PubMed

    Goto, Aya; Mouri, Akihiro; Nagai, Tomoko; Yoshimi, Akira; Ukigai, Mako; Tsubai, Tomomi; Hida, Hirotake; Ozaki, Norio; Noda, Yukihiro

    2016-09-01

    Clozapine is an effective antipsychotic for treatment-resistant schizophrenia, but can cause fatal hematopoietic toxicity as agranulocytosis. To elucidate the mechanism of hematopoietic toxicity induced by clozapine, we developed an in vitro assay system using HL-60 cells, and investigated the effect on hematopoiesis. HL-60 cells were differentiated by all-trans retinoic acid (ATRA) into three states according to the following hematopoietic process: undifferentiated HL-60 cells, those undergoing granulocytic ATRA-differentiation, and ATRA-differentiated granulocytic cells. Hematopoietic toxicity was evaluated by analyzing cell survival, cell proliferation, granulocytic differentiation, apoptosis, and necrosis. In undifferentiated HL-60 cells and ATRA-differentiated granulocytic cells, both clozapine (50 and 100μM) and doxorubicin (0.2µM) decreased the cell survival rate, but olanzapine (1-100µM) did not. Under granulocytic differentiation for 5days, clozapine, even at a concentration of 25μM, decreased survival without affecting granulocytic differentiation, increased caspase activity, and caused apoptosis rather than necrosis. Histamine H4 receptor mRNA was expressed in HL-60 cells, whereas the expression decreased under granulocytic ATRA-differentiation little by little. Both thioperamide, a histamine H4 receptor antagonist, and DEVD-FMK, a caspase-3 inhibitor, exerted protection against clozapine-induced survival rate reduction, but not of live cell counts. 4-Methylhistamine, a histamine H4 receptor agonist, decreased the survival rate and live cell counts, as did clozapine. HL-60 cells under granulocytic differentiation are vulnerable under in vitro assay conditions to hematopoietic toxicity induced by clozapine. Histamine H4 receptor is involved in the development of clozapine-induced hematopoietic toxicity through apoptosis, and may be a potential target for preventing its occurrence through granulocytic differentiation.

  20. Ferroelectric Field-Effect Transistor Differential Amplifier Circuit Analysis

    NASA Technical Reports Server (NTRS)

    Phillips, Thomas A.; MacLeod, Todd C.; Ho, Fat D.

    2008-01-01

    There has been considerable research investigating the Ferroelectric Field-Effect Transistor (FeFET) in memory circuits. However, very little research has been performed in applying the FeFET to analog circuits. This paper investigates the use of FeFETs in a common analog circuit, the differential amplifier. The two input Metal-Oxide-Semiconductor (MOS) transistors in a general MOS differential amplifier circuit are replaced with FeFETs. Resistors are used in place of the other three MOS transistors. The FeFET model used in the analysis has been previously reported and was based on experimental device data. Because of the FeFET hysteresis, the FeFET differential amplifier has four different operating modes depending on whether the FeFETs are positively or negatively polarized. The FeFET differential amplifier operation in the different modes was analyzed by calculating the amplifier voltage transfer and gain characteristics shown in figures 2 through 5. Comparisons were made between the FeFET differential amplifier and the standard MOS differential amplifier. Possible applications and benefits of the FeFET differential amplifier are discussed.

  1. Lactic Acid is Elevated in Idiopathic Pulmonary Fibrosis and Induces Myofibroblast Differentiation Via pH-Dependent Activation of Transforming Growth Factor-β

    SciTech Connect

    Kottman, R. M.; Kulkarni, Ajit A.; Smolnycki, Katie A.; Lyda, Elizabeth; Dahanayake, Thinesh; Salibi, Rami; Honnons, Sylvie; Jones, Carolyn; Isern, Nancy G.; Hu, Jian Z.; Nathan, Steven D.; Grant, Geraldine; Phipps, Richard P.; Sime, Patricia J.

    2012-10-15

    Rationale: Idiopathic pulmonary fibrosis (IPF) is a complex disease for which the pathogenesis is poorly understood. In this study, we identified lactic acid as a metabolite that is elevated in the lung tissue of patients with IPF. Objectives: This study examines the effect of lactic acid on myofibroblast differentiation and pulmonary fibrosis. Methods:We used metabolomic analysis to examine cellular metabolism in lung tissuefrom patients with IPFanddeterminedthe effects of lactic acid and lactate dehydrogenase-5 (LDH5) overexpression on myofibroblast differentiation and transforming growth factor (TGF)-b activation in vitro. Measurements and Main Results: Lactic acid concentrations from healthy and IPF lung tissue were determined by nuclear magnetic resonance spectroscopy; a-smooth muscle actin, calponin, and LDH5 expression were assessed by Western blot of cell culture lysates. Lactic acid and LDH5 were significantly elevated in IPF lung tissue compared with controls. Physiologic concentrations of lactic acid induced myofibroblast differentiation via activation of TGF-b. TGF-b induced expression of LDH5 via hypoxia-inducible factor 1a (HIF1a). Importantly, overexpression of both HIF1a and LDH5 in human lung fibroblasts induced myofibroblast differentiation and synergized with low dose TGF-b to induce differentiation. Furthermore, inhibition of both HIF1a and LDH5 inhibited TGF-b–induced myofibroblast differentiation. Conclusions: We have identified the metabolite lactic acid as an important mediator of myofibroblast differentiation via a pHdependent activation of TGF-b. We propose that the metabolic milieu of the lung, and potentially other tissues, is an important driving force behind myofibroblast differentiation and potentially the initiation and progression of fibrotic disorders.

  2. How-to-Do-It: Cytokinin Induced Cell Division & Differentiation Using Intact Plants.

    ERIC Educational Resources Information Center

    Bohnsack, Charles W.

    1989-01-01

    Presents a procedure by which cytokinins are used to induce a population of dividing and differentiating cells on the cut surface of the roots of an intact plant. Includes the method used, results, and suggestions for a variety of variables that may be tested. (RT)

  3. Secreted Cyclic Di-GMP Induces Stalk Cell Differentiation in the Eukaryote Dictyostelium discoideum.

    PubMed

    Chen, Zhi-hui; Schaap, Pauline

    2016-01-01

    Cyclic di-GMP (c-di-GMP) is currently recognized as the most widely used intracellular signal molecule in prokaryotes, but roles in eukaryotes were only recently discovered. In the social amoeba Dictyostelium discoideum, c-di-GMP, produced by a prokaryote-type diguanylate cyclase, induces the differentiation of stalk cells, thereby enabling the formation of spore-bearing fruiting bodies. In this review, we summarize the currently known mechanisms that control the major life cycle transitions of Dictyostelium and focus particularly on the role of c-di-GMP in stalk formation. Stalk cell differentiation has characteristics of autophagic cell death, a process that also occurs in higher eukaryotes. We discuss the respective roles of c-di-GMP and of another signal molecule, differentiation-inducing factor 1, in autophagic cell death in vitro and in stalk formation in vivo.

  4. Maintenance and Neuronal Differentiation of Chicken Induced Pluripotent Stem-Like Cells

    PubMed Central

    Rossello, Ricardo; Chen, Chun-chun; Kessler, Joeran; Davison, Ian; Jarvis, Erich D.

    2014-01-01

    Pluripotent stem cells have the potential to become any cell in the adult body, including neurons and glia. Avian stem cells could be used to study questions, like vocal learning, that would be difficult to examine with traditional mouse models. Induced pluripotent stem cells (iPSCs) are differentiated cells that have been reprogrammed to a pluripotent stem cell state, usually using inducing genes or other molecules. We recently succeeded in generating avian iPSC-like cells using mammalian genes, overcoming a limitation in the generation and use of iPSCs in nonmammalian species (Rosselló et al., 2013). However, there were no established optimal cell culture conditions for avian iPSCs to establish long-term cell lines and thus to study neuronal differentiation in vitro. Here we present an efficient method of maintaining chicken iPSC-like cells and for differentiating them into action potential generating neurons. PMID:25610469

  5. Maintenance and neuronal differentiation of chicken induced pluripotent stem-like cells.

    PubMed

    Dai, Rui; Rossello, Ricardo; Chen, Chun-Chun; Kessler, Joeran; Davison, Ian; Hochgeschwender, Ute; Jarvis, Erich D

    2014-01-01

    Pluripotent stem cells have the potential to become any cell in the adult body, including neurons and glia. Avian stem cells could be used to study questions, like vocal learning, that would be difficult to examine with traditional mouse models. Induced pluripotent stem cells (iPSCs) are differentiated cells that have been reprogrammed to a pluripotent stem cell state, usually using inducing genes or other molecules. We recently succeeded in generating avian iPSC-like cells using mammalian genes, overcoming a limitation in the generation and use of iPSCs in nonmammalian species (Rosselló et al., 2013). However, there were no established optimal cell culture conditions for avian iPSCs to establish long-term cell lines and thus to study neuronal differentiation in vitro. Here we present an efficient method of maintaining chicken iPSC-like cells and for differentiating them into action potential generating neurons.

  6. Differentiation state affects morphine induced cell regulation in neuroblastoma cultured cells.

    PubMed

    Fiore, Giovina; Ghelardini, Carla; Bruni, Giancarlo; Guarna, Massimo; Bianchi, Enrica

    2013-10-25

    Neuroblastoma (NB) is the most common extracranial solid cancer in childhood and the most common cancer in infancy. Our purpose was to investigate in vitro how cancer cell survival occurs in presence of morphine in undifferentiated and differentiated SHSY-5Y human neuroblastoma cultured cell line. Exposure of differentiated cells to morphine dose-dependently induced apoptosis in these cells through c-Jun N-terminal kinase (JNK)/caspase pathway. Otherwise, morphine induced activation for mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathway, caused positive regulation of cell survival in undifferentiated cells. Therefore, cell differentiation state bimodally affects the cellular regulation activity triggered by morphine in isolated cultured neuroblastoma cells raising concerns about the application of morphine to this type of cancer patients.

  7. Epigallocatechin-3-gallate Protects against Hydrogen Peroxide-Induced Inhibition of Osteogenic Differentiation of Human Bone Marrow-Derived Mesenchymal Stem Cells

    PubMed Central

    Wang, Dawei; Wang, Yonghui; Xu, Shihong; Wang, Fu; Wang, Bomin; Han, Ke; Sun, Daqing; Li, Lianxin

    2016-01-01

    Oxidative stress induces bone loss and osteoporosis, and epigallocatechin-3-gallate (EGCG) may be used to combat these diseases due to its antioxidative property. Herein, oxidative stress in human bone marrow-derived mesenchymal stem cells (BM-MSCs) was induced by H2O2, resulting in an adverse effect on their osteogenic differentiation. However, this H2O2-induced adverse effect was nullified when the cells were treated with EGCG. In addition, treatment of BM-MSCs with EGCG alone also resulted in the enhancement of osteogenic differentiation of BM-MSCs. After EGCG treatment, expressions of β-catenin and cyclin D1 were upregulated, suggesting that the Wnt pathway was involved in the effects of EGCG on the osteogenic differentiation of BM-MSCs. This was also confirmed by the fact that the Wnt pathway inhibitor, Dickkopf-1 (DKK-1), can nullify the EGCG-induced enhancement effect on BM-MSC's osteogenic differentiation. Hence, our results suggested that EGCG can reduce the effects of oxidative stress on Wnt pathway in osteogenic cells, which supported a potentially promising therapy of bone disorders induced by oxidative stress. Considering its positive effects on BM-MSCs, EGCG may also be beneficial for stem cell-based bone repair. PMID:26977159

  8. Flavanonol taxifolin attenuates proteasome inhibition-induced apoptosis in differentiated PC12 cells by suppressing cell death process.

    PubMed

    Nam, Yoon Jeong; Lee, Da Hee; Shin, Yong Kyoo; Sohn, Dong Suep; Lee, Chung Soo

    2015-03-01

    The proteasomal dysfunction and mitochondrial impairment has been implicated in neuronal degeneration. Taxifolin has antioxidant and anti-inflammatory effects. However, the effect of taxifolin on the neuronal cell death induced by proteasome inhibition has not been studied. Therefore, in the respect of cell death process, we assessed the effect of taxifolin on the proteasome inhibition-induced apoptosis in neuronal cell injury using differentiated PC12 cells. The proteasome inhibitors MG132 and MG115 induced a decrease in Bid, Bcl-2, and survivin protein levels, an increase in Bax, loss of the mitochondrial transmembrane potential, cytochrome c release, activation of caspases(-8, -9 and -3), an increase in the tumor suppressor p53 levels and cleavage of PARP-1. The addition of taxifolin attenuated the proteasome inhibitor-induced changes in the apoptosis-related protein levels, formation of reactive oxygen species, depletion and oxidation of GSH, formations of malondialdehyde and carbonyls, and cell death. The results show that taxifolin may attenuate the proteasome inhibitor-induced apoptosis in PC12 cells by suppressing the activation of the mitochondrial pathway and the caspase-8- and Bid-dependent pathways. The preventive effect of taxifolin appears to be attributed to its inhibitory effect on the formation of reactive oxygen species, and depletion and oxidation of GSH.

  9. Electrospun tilapia collagen nanofibers accelerating wound healing via inducing keratinocytes proliferation and differentiation.

    PubMed

    Zhou, Tian; Wang, Nanping; Xue, Yang; Ding, Tingting; Liu, Xin; Mo, Xiumei; Sun, Jiao

    2016-07-01

    The development of biomaterials with the ability to induce skin wound healing is a great challenge in biomedicine. In this study, tilapia skin collagen sponge and electrospun nanofibers were developed for wound dressing. The collagen sponge was composed of at least two α-peptides. It did not change the number of spleen-derived lymphocytes in BALB/c mice, the ratio of CD4(+)/CD8(+) lymphocytes, and the level of IgG or IgM in Sprague-Dawley rats. The tensile strength and contact angle of collagen nanofibers were 6.72±0.44MPa and 26.71±4.88°, respectively. They also had good thermal stability and swelling property. Furthermore, the nanofibers could significantly promote the proliferation of human keratinocytes (HaCaTs) and stimulate epidermal differentiation through the up-regulated gene expression of involucrin, filaggrin, and type I transglutaminase in HaCaTs. The collagen nanofibers could also facilitate rat skin regeneration. In the present study, electrospun biomimetic tilapia skin collagen nanofibers were succesfully prepared, were proved to have good bioactivity and could accelerate rat wound healing rapidly and effectively. These biological effects might be attributed to the biomimic extracellular matrix structure and the multiple amino acids of the collagen nanofibers. Therefore, the cost-efficient tilapia collagen nanofibers could be used as novel wound dressing, meanwhile effectively avoiding the risk of transmitting animal disease in the future clinical apllication.

  10. Anxiety response and restraint-induced stress differentially affect ethanol intake in female adolescent rats.

    PubMed

    Acevedo, María Belén; Fabio, Maria Carolina; Fernández, Macarena Soledad; Pautassi, Ricardo Marcos

    2016-10-15

    Anxiety disorders are more likely to occur in women than in men, usually emerge during adolescence and exhibit high comorbidity with alcohol use disorders (AUD). Adolescents with high levels of anxiety or heightened reactivity to stress may be at-risk for developing AUD. An approach to analyze if high levels of inborn anxiety predict greater ethanol drinking is to assess the latter variable in subjects classified as high- or low-anxiety responders. The present study assessed ethanol drinking in adolescent, female Wistar, rats classified as high-, low- or average-anxiety responders and exposed or not to restraint stress (RS, Exp. 1). Classification was made through a multivariate index derived from testing anxiety responses in an elevated plus maze and a light-dark box tests. RS was applied after animals had been initiated to ethanol drinking. Intake of sweetened ethanol was unaffected by level of anxiety response. Adolescents with high levels of inborn anxiety exhibited significantly higher intake of unsweetened ethanol than counterparts with standard levels of anxiety, yet this effect was inhibited by RS exposure. Experiment 2 assessed FOS immunoreactivity after RS. Stress induced a significant increase in FOS immunoreactivity at the paraventricular nucleus, yet this effect was unaffected by level of anxiety response. Female adolescents with high levels of basal anxiety may be at-risk for exhibiting increased predisposition for ethanol intake and preference. The study also indicates that stress may exert differential effects on adolescent ethanol intake as a function of the level of anxiety response.

  11. Valproic acid induces differentiation and transient tumor regression, but spares leukemia-initiating activity in mouse models of APL.

    PubMed

    Leiva, M; Moretti, S; Soilihi, H; Pallavicini, I; Peres, L; Mercurio, C; Dal Zuffo, R; Minucci, S; de Thé, H

    2012-07-01

    Aberrant histone acetylation was physiopathologically associated with the development of acute myeloid leukemias (AMLs). Reversal of histone deacetylation by histone deacetylase inhibitor (HDACis) activates a cell death program that allows tumor regression in mouse models of AMLs. We have used several models of PML-RARA-driven acute promyelocytic leukemias (APLs) to analyze the in vivo effects of valproic acid, a well-characterized HDACis. Valproic acid (VPA)-induced rapid tumor regression and sharply prolonged survival. However, discontinuation of treatment was associated to an immediate relapse. In vivo, as well as ex vivo, VPA-induced terminal granulocytic differentiation. Yet, despite full differentiation, leukemia-initiating cell (LIC) activity was actually enhanced by VPA treatment. In contrast to all-trans retinoic acid (ATRA) or arsenic, VPA did not degrade PML-RARA. However, in combination with ATRA, VPA synergized for PML-RARA degradation and LIC eradication in vivo. Our studies indicate that VPA triggers differentiation, but spares LIC activity, further uncouple differentiation from APL clearance and stress the importance of PML-RARA degradation in APL cure.

  12. Normal Human Lung Epithelial Cells Inhibit Transforming Growth Factor-β Induced Myofibroblast Differentiation via Prostaglandin E2

    PubMed Central

    Epa, Amali P.; Thatcher, Thomas H.; Pollock, Stephen J.; Wahl, Lindsay A.; Lyda, Elizabeth; Kottmann, R. M.; Phipps, Richard P.; Sime, Patricia J.

    2015-01-01

    Introduction Idiopathic pulmonary fibrosis (IPF) is a chronic progressive disease with very few effective treatments. The key effector cells in fibrosis are believed to be fibroblasts, which differentiate to a contractile myofibroblast phenotype with enhanced capacity to proliferate and produce extracellular matrix. The role of the lung epithelium in fibrosis is unclear. While there is evidence that the epithelium is disrupted in IPF, it is not known whether this is a cause or a result of the fibroblast pathology. We hypothesized that healthy epithelial cells are required to maintain normal lung homeostasis and can inhibit the activation and differentiation of lung fibroblasts to the myofibroblast phenotype. To investigate this hypothesis, we employed a novel co-culture model with primary human lung epithelial cells and fibroblasts to investigate whether epithelial cells inhibit myofibroblast differentiation. Measurements and Main Results In the presence of transforming growth factor (TGF)-β, fibroblasts co-cultured with epithelial cells expressed significantly less α-smooth muscle actin and collagen and showed marked reduction in cell migration, collagen gel contraction, and cell proliferation compared to fibroblasts grown without epithelial cells. Epithelial cells from non-matching tissue origins were capable of inhibiting TGF-β induced myofibroblast differentiation in lung, keloid and Graves’ orbital fibroblasts. TGF-β promoted production of prostaglandin (PG) E2 in lung epithelial cells, and a PGE2 neutralizing antibody blocked the protective effect of epithelial cell co-culture. Conclusions We provide the first direct experimental evidence that lung epithelial cells inhibit TGF-β induced myofibroblast differentiation and pro-fibrotic phenotypes in fibroblasts. This effect is not restricted by tissue origin, and is mediated, at least in part, by PGE2. Our data support the hypothesis that the epithelium plays a crucial role in maintaining lung homeostasis

  13. Rosmarinic acid potentiates ATRA-induced macrophage differentiation in acute promyelocytic leukemia NB4 cells.

    PubMed

    Heo, Sook-Kyoung; Noh, Eui-Kyu; Yoon, Dong-Joon; Jo, Jae-Cheol; Koh, SuJin; Baek, Jin Ho; Park, Jae-Hoo; Min, Young Joo; Kim, Hawk

    2015-01-15

    Rosmarinic acid (RA, an ester of caffeic acid and 3,4-dihydroxyphenyllactic acid) has a number of biological activities, but little is known about anti-leukemic activities of RA combined with all-trans retinoic acid (ATRA) against acute promyelocytic leukemia (APL) cells. We examined the differentiation marker, CD11b, in bone marrow cells (BMC) of an APL patient, in NB4 cells (APL cell line), and in normal BMC and peripheral blood mononuclear cells (PBMC) of healthy subjects by flow cytometric analysis. ATRA/RA induced expression of CD11b in the BMC of the APL patient and in NB4 cells, but not in normal BMC or PBMC. Therefore, we realized that RA potentiated ATRA-induced macrophage differentiation in APL cells. Further characterization of the induced macrophages showed that they exhibited morphological changes and were able to phagocytose and generate reactive oxygen species. Th also had typical expression of C-C chemokine receptor type 1 (CCR1), CCR2, and intercellular adhesion molecule-1 (ICAM-1). Moreover, the expression of CD11b(+) and CD14(+) cells depended on ERK-NF-κB axis activation. Together, these results indicate that RA potentiates ATRA-induced macrophage differentiation in APL cells. Thus, RA may play an important role as an appurtenant differentiation agent for functional macrophage differentiation in APL. Additionally, the differentiated macrophages might have a normal life span and, they could die. These data indicate that co-treatment with RA and ATRA has potential as an anti-leukemic therapy in APL.

  14. Effect of Differential Item Functioning on Test Equating

    ERIC Educational Resources Information Center

    Kabasakal, Kübra Atalay; Kelecioglu, Hülya

    2015-01-01

    This study examines the effect of differential item functioning (DIF) items on test equating through multilevel item response models (MIRMs) and traditional IRMs. The performances of three different equating models were investigated under 24 different simulation conditions, and the variables whose effects were examined included sample size, test…

  15. 25-Hydroxyvitamin D3 induces osteogenic differentiation of human mesenchymal stem cells

    PubMed Central

    Lou, Yan-Ru; Toh, Tai Chong; Tee, Yee Han; Yu, Hanry

    2017-01-01

    25-Hydroxyvitamin D3 [25(OH)D3] has recently been found to be an active hormone. Its biological actions are demonstrated in various cell types. 25(OH)D3 deficiency results in failure in bone formation and skeletal deformation. Here, we investigated the effect of 25(OH)D3 on osteogenic differentiation of human mesenchymal stem cells (hMSCs). We also studied the effect of 1α,25-dihydroxyvitamin D3 [1α,25-(OH)2D3], a metabolite of 25(OH)D3. One of the vitamin D responsive genes, 25(OH)D3-24-hydroxylase (cytochrome P450 family 24 subfamily A member 1) mRNA expression is up-regulated by 25(OH)D3 at 250–500 nM and by 1α,25-(OH)2D3 at 1–10 nM. 25(OH)D3 and 1α,25-(OH)2D3 at a time-dependent manner alter cell morphology towards osteoblast-associated characteristics. The osteogenic markers, alkaline phosphatase, secreted phosphoprotein 1 (osteopontin), and bone gamma-carboxyglutamate protein (osteocalcin) are increased by 25(OH)D3 and 1α,25-(OH)2D3 in a dose-dependent manner. Finally, mineralisation is significantly increased by 25(OH)D3 but not by 1α,25-(OH)2D3. Moreover, we found that hMSCs express very low level of 25(OH)D3-1α-hydroxylase (cytochrome P450 family 27 subfamily B member 1), and there is no detectable 1α,25-(OH)2D3 product. Taken together, our findings provide evidence that 25(OH)D3 at 250–500 nM can induce osteogenic differentiation and that 25(OH)D3 has great potential for cell-based bone tissue engineering. PMID:28211493

  16. Vitamin D induces myogenic differentiation in skeletal muscle derived stem cells.

    PubMed

    Braga, Melissa; Simmons, Zena; Norris, Keith C; Ferrini, Monica G; Artaza, Jorge N

    2017-04-01

    Skeletal muscle wasting is a serious disorder associated with health conditions such as aging, chronic kidney disease and AIDS. Vitamin D is most widely recognized for its regulation of calcium and phosphate homeostasis in relation to bone development and maintenance. Recently, vitamin D supplementation has been shown to improve muscle performance and reduce the risk of falls in vitamin D deficient older adults. However, little is known of the underlying molecular mechanism(s) or the role it plays in myogenic differentiation. We examined the effect of 1,25-D3 on myogenic cell differentiation in skeletal muscle derived stem cells. Primary cultures of skeletal muscle satellite cells were isolated from the tibialis anterior, soleus and gastrocnemius muscles of 8-week-old C57/BL6 male mice and then treated with 1,25-D3 The efficiency of satellite cells isolation determined by PAX7+ cells was 81%, and they expressed VDR. Incubation of satellite cells with 1,25-D3 induces increased expression of: (i) MYOD, (ii) MYOG, (iii) MYC2, (iv) skeletal muscle fast troponin I and T, (v) MYH1, (vi) IGF1 and 2, (vii) FGF1 and 2, (viii) BMP4, (ix) MMP9 and (x) FST. It also promotes myotube formation and decreases the expression of MSTN. In conclusion, 1,25-D3 promoted a robust myogenic effect on satellite cells responsible for the regeneration of muscle after injury or muscle waste. This study provides a mechanistic justification for vitamin D supplementation in conditions characterized by loss of muscle mass and also in vitamin D deficient older adults with reduced muscle mass and strength, and increased risk of falls.

  17. Inhibition of p38 MAPK Phosphorylation Is Critical for Bestatin to Enhance ATRA-Induced Cell Differentiation in Acute Promyelocytic Leukemia NB4 Cells.

    PubMed

    Qian, Xijun; He, Jingsong; Zhao, Yi; Lin, Maofang

    2016-01-01

    Bestatin has been known as an immunomodulating agent in anti-leukemia treatment. The mechanism by which Bestatin enhances all-trans retinoic acid (ATRA)-induced cell differentiation of acute promyelocytic leukemia (APL) cells is generally attributed to inhibition of cell surface CD13/aminopeptidase N activity. Bestatin also exerts its biological activities besides its ability to inhibit aminopeptidase N enzymatic activity. This article provides data to support an alternative mechanism regarding an important role of inhibition of p38 mitogen-activated protein kinase (MAPK) signal pathway in Bestatin's anti-leukemia effect. Bestatin enhanced ATRA-induced differentiation and inhibited ATRA-driven phosphorylation of p38 MAPK in ATRA-sensitive APL NB4 cells. In contrast, Bestatin could not reverse the differentiation block in ATRA-resistant APL MR2 cells, in which ATRA was unable to induce phosphorylation of p38 MAPK. Moreover, CD13 ligation with anti-CD13 antibody WM-15 resulted in phosphorylation of p38 MAPK, reduced the inhibition of Bestatin on the phosphorylation of p38 MAPK, and completely abolished the enhancement of Bestatin on ATRA-inducing differentiation in NB4 cells. This study shows that inhibition of p38 MAPK phosphorylation is critical for Bestatin to enhance ATRA-induced cell differentiation in ATRA-sensitive APL NB4 cells. Results suggested that pharmacological inhibition of the p38 MAPK pathway might enhance ATRA-dependent differentiation.

  18. Pro-differentiating effects of a synthetic flavagline on human teratocarcinomal cancer stem-like cells.

    PubMed

    Emhemmed, Fathi; Ali Azouaou, Sarah; Zhao, Qian; Appert-Collin, Aline; Bennasroune, Amar; Schini-Kerth, Valérie B; Muller, Christian D; Désaubry, Laurent; Fuhrmann, Guy

    2016-12-15

    As initiators of the carcinogenic process, cancer stem cells (CSCs) are considered as new targets for anti-cancer therapies. However, these cells are hidden in the cancer bulk and remain relatively insensitive to chemotherapy, which targets their proliferative capacities. Alternatively, growing evidences have pointed out that a differentiation therapy could adversely affect these cells, which consequently should lose their self-renewal properties and become less aggressive. In order to evaluate the differentiation potential of an emerging class of anti-cancer drugs, we used the poorly differentiated teratocarcinomal cell as a model of Oct4-expressing CSC and determined the molecular mechanisms induced by the highly active flavagline FL3. The drug, administrated at sublethal concentration and for long period, was able to downregulate the expression levels of the stemness factors Oct4 and Nanog at both transcriptional and translational levels, concomitantly with a decrease of clonogenicity. The appearance of specific neural markers further demonstrated the differentiation properties of FL3. Interestingly, an expression of active caspase-3 and an upregulation of the expression of the germ cell nuclear factor were observed in treated cells; this suggests that the suppression of Oct4 expression required for the induction of differentiation involves overlapping mechanisms of protein degradation and gene repression. Finally, this study shows that FL3, like all-trans retinoic acid (ATRA), acts as a differentiation inducer of teratocarcinomal cells. Thus, FL3 offers an alternative possibility for cancer treatment since it could target the carcinogenic process by inducing the differentiation of ATRA-resistant and Oct4-expressing CSCs, without toxic side effects on normal cells.

  19. Rhus javanica Gall Extract Inhibits the Differentiation of Bone Marrow-Derived Osteoclasts and Ovariectomy-Induced Bone Loss

    PubMed Central

    Kim, Tae-Ho; Park, Eui Kyun; Huh, Man-Il; Kim, Hong Kyun; Kim, Shin-Yoon; Lee, Sang-Han

    2016-01-01

    Inhibition of osteoclast differentiation and bone resorption is a therapeutic strategy for the management of postmenopausal bone loss. This study investigated the effects of Rhus javanica (R. javanica) extracts on bone marrow cultures to develop agents from natural sources that may prevent osteoclastogenesis. Extracts of R. javanica (eGr) cocoons spun by Rhus javanica (Bell.) Baker inhibited the osteoclast differentiation and bone resorption. The effects of aqueous extract (aeGr) or 100% ethanolic extract (eeGr) on ovariectomy- (OVX-) induced bone loss were investigated by various biochemical assays. Furthermore, microcomputed tomography (µCT) was performed to study bone remodeling. Oral administration of eGr (30 mg or 100 mg/kg/day for 6 weeks) augmented the inhibition of femoral bone mineral density (BMD), bone mineral content (BMC), and other factors involved in bone remodeling when compared to OVX controls. Additionally, eGr slightly decreased bone turnover markers that were increased by OVX. Therefore, it may be suggested that the protective effects of eGr could have originated from the suppression of OVX-induced increase in bone turnover. Collectively, the findings of this study indicate that eGr has potential to activate bone remodeling by inhibiting osteoclast differentiation and bone loss. PMID:27313644

  20. Effects of endocrine modulators on sex differentiation in birds.

    PubMed

    Brunström, Björn; Axelsson, Jeanette; Halldin, Krister

    2003-01-01

    This mini-review focuses on sexual differentiation of the reproductive organs and the brain in birds and the effects of endocrine modulators on these processes. Sex determination in birds is genetically controlled, but the genetic events implicated are largely unknown. Female birds have one Z and one W sex chromosome, while males have two Z sex chromosomes. It is not clear whether it is the presence of the W chromosome in females, the double dose of the Z chromosome in males vis-à-vis females, or both of these characteristics that are crucial for the determination of sex in birds. Oestradiol directs sexual differentiation in birds during critical periods of development. Consequently, exogenous compounds that interfere with the endogenous oestrogen balance can disrupt sexual differentiation of the reproductive organs and the brain. Therefore, sexual differentiation in birds provides a good model for studying the effects of endocrine modulators at various biological levels from gene expression to behaviour. Some compounds known to be present in the environment can alter endocrine function and have adverse effects when administered during development, resulting in alterations in gonads, accessory sexual organs, and behaviour. Data reviewed in this paper are mostly from laboratory studies on endocrine modulators with oestrogenic activity, whereas evidence for adverse effects of pollutants on sexual differentiation in avian wildlife is scarce.

  1. α-Tocopherol induces hematopoietic stem/progenitor cell expansion and ERK1/2-mediated differentiation.

    PubMed

    Nogueira-Pedro, Amanda; Barbosa, Christiano M V; Segreto, Helena Regina Comodo; Lungato, Lisandro; D'Almeida, Vania; Moraes, Andrea Aparecida F S; Miranda, Antonio; Paredes-Gamero, Edgar Julian; Ferreira, Alice Teixeira

    2011-12-01

    Tocopherols promote or inhibit growth in different cell types. In the hematopoietic system, the radioprotective property of tocopherols is thought to act through the expansion of primitive hematopoietic cells. However, the mechanisms activated by tocopherols and which HPs are affected remain poorly understood. To better address these questions, mice were treated with α-tocopherol, and its effects were investigated in the BM microenvironment. α-Tocopherol induced increased proliferation in HSC/HP cells, leading to BM hyperplasia. In addition, differentiation to the granulocytic/monocytic lineage was enhanced by α-tocopherol treatment. α-Tocopherol treatment resulted in decreased basal phosphorylation of ERK1/2, PKC, and STAT-5 in HSC/HP cells. In contrast, α-tocopherol enhanced ERK1/2 activation in response to IL-3 stimulation in HSC/HP cells without altering the expression of IL-3Rs. Moreover, α-tocopherol-induced differentiation and ERK1/2 activation were abolished in mice pretreated with a MEK inhibitor (PD98059); however, pretreatment with PD98059 did not reduce the α-tocopherol-mediated increase in HSC/HP cells but instead, further enhanced their proliferation. Therefore, α-tocopherol induces expansion of HSC/HP cells by a nonidentified intracellular pathway and granulocytic/monocytic differentiation through ERK1/2 activation.

  2. Effect of microcystin-LR on human placental villous trophoblast differentiation in vitro.

    PubMed

    Douglas, Gordon C; Thirkill, Twanda L; Kumar, Priyadarsini; Loi, Minerva; Hilborn, Elizabeth D

    2016-04-01

    Microcystin-LR is a cyanobacterial toxin found in surface and recreational waters that inhibits protein phosphatases and may disrupt the cytoskeleton. Microcystins induce apoptosis in hepatocytes at ≤ 2.0 µM. Nothing is known about the effects of microcystins on human placental trophoblast differentiation and function. The differentiation of villous trophoblasts to form syncytiotrophoblast occurs throughout pregnancy and is essential for normal placental and fetal development. To investigate the effects of microcystin, villous cytotrophoblasts were isolated from term placentas using an established method and exposed to microcystin-LR. Microcystin-LR below the cytotoxic dose of 25 µM did not cause cell rounding or detachment, had no effect on apoptosis, and no effect on the morphological differentiation of mononucleated cytotrophoblasts to multinucleated syncytiotrophoblast. However, secretion of human chorionic gonadotropin (hCG) increased in a microcystin-LR dose-dependent manner. When incubated with l-buthionine sulphoximine (BSO) to deplete glutathione levels, trophoblast morphological differentiation proceeded normally in the presence of microcystin-LR. Microcystin-LR did not disrupt the trophoblast microtubule cytoskeleton, which is known to play a role in trophoblast differentiation. Immunofluorescence studies showed that trophoblasts express organic anion transport protein 1B3 (OATP1B3), a known microcystin transport protein. In comparison to hepatocytes, trophoblasts appear to be more resistant to the toxic effects of microcystin-LR. The physiological implications of increased hCG secretion in response to microcystin-LR exposure remain to be determined.

  3. Differentiation of mouse induced pluripotent stem cells into neurons using conditioned medium of dorsal root ganglia.

    PubMed

    Kitazawa, Ayako; Shimizu, Norio

    2011-07-01

    Mouse induced pluripotent stem (iPS) cells are known to have the ability to differentiate into various cell lineages including neurons in vitro. We have reported that chick dorsal root ganglion (DRG)-conditioned medium (CM) promoted the differentiation of mouse embryonic stem (ES) cells into motor neurons. We investigated the formation of undifferentiated iPS cell colonies and the differentiation of iPS cells into neurons using DRG-CM. When iPS cells were cultured in DMEM containing leukemia inhibitory factor (LIF), the iPS cells appeared to be maintained in an undifferentiated state for 19 passages. The number of iPS cell colonies (200 μm in diameter) was maximal at six days of cultivation and the colonies were maintained in an undifferentiated state, but the iPS cell colonies at ten days of cultivation had hollows inside the colonies and were differentiated. By contrast, the number of ES cell colonies (200 μm in diameter) was maximal at ten days of cultivation. The iPS cells were able to proliferate and differentiate easily into various cell lineages, compared to ES cells. When iPS cell colonies were cultured in a manner similar to ES cells with DMEM/F-12K medium supplemented with DRG-CM, the iPS cells mainly differentiated into motor and sensory neurons. These results suggested that the differentiation properties of iPS cells differ from those of ES cells.

  4. KDM5A controls bone morphogenic protein 2-induced osteogenic differentiation of bone mesenchymal stem cells during osteoporosis

    PubMed Central

    Wang, Chuandong; Wang, Jing; Li, Jiao; Hu, Guoli; Shan, Shengzhou; Li, Qingfeng; Zhang, Xiaoling

    2016-01-01

    Bone morphogenetic protein 2 (BMP2) has been used to induce bone regeneration by promoting osteogenic differentiation of bone marrow-derived mesenchymal stem cells (MSCs). However, its effect is attenuated in osteoporotic conditions by unknown mechanisms. In this study, we investigated the molecular mechanisms of reduced osteogenic effect of BMP2 in osteoporotic conditions. By interrogating the microarray data from osteoporosis patients, we revealed an upregulation of the epigenetic modifying protein lysine (K)-specific demethylase 5A (KDM5A) and decreased Runt-related transcription factor 2 (RUNX2) expression. Further studies were focused on the role of KDM5A in osteoporosis. We first established ovariectomized (OVX) mouse model and found that the BMP2-induced osteogenic differentiation of osteoporotic MSCs was impaired. The elevated level of KDM5A was confirmed in osteoporotic MSCs. Overexpression of KDM5A in normal MSCs inhibited BMP2-induced osteogenesis. Moreover, osteogenic differentiation of osteoporotic MSCs was restored by specific KDM5A short hairpin RNA or inhibitor. Furthermore, by chromatin immunoprecipitation assay we demonstrated that KDM5A functions as endogenous modulator of osteogenic differentiation by decreasing H3K4me3 levels on promoters of Runx2, depend on its histone methylation activity. More importantly, we found an inhibitory role of KDM5A in regulating bone formation in osteoporotic mice, and pretreatment with KDM5A inhibitor partly rescued the bone loss during osteoporosis. Our results show, for the first time, that KDM5A-mediated H3K4me3 modification participated in the etiology of osteoporosis and may provide new strategies to improve the clinical efficacy of BMP2 in osteoporotic conditions. PMID:27512956

  5. Capsaicin Induces “Brite” Phenotype in Differentiating 3T3-L1 Preadipocytes

    PubMed Central

    Baboota, Ritesh K.; Singh, Dhirendra P.; Sarma, Siddhartha M.; Kaur, Jaspreet; Sandhir, Rajat; Boparai, Ravneet K.; Kondepudi, Kanthi K.; Bishnoi, Mahendra

    2014-01-01

    Objective Targeting the energy storing white adipose tissue (WAT) by pharmacological and dietary means in order to promote its conversion to energy expending “brite” cell type holds promise as an anti-obesity approach. Present study was designed to investigate/revisit the effect of capsaicin on adipogenic differentiation with special reference to induction of “brite” phenotype during differentiation of 3T3-L1 preadipocytes. Methods Multiple techniques such as Ca2+ influx assay, Oil Red-O staining, nutrigenomic analysis in preadipocytes and matured adipocytes have been employed to understand the effect of capsaicin at different doses. In addition to in-vitro experiments, in-vivo studies were carried out in high-fat diet (HFD) fed rats treated with resiniferatoxin (RTX) (a TRPV1 agonist) and in mice administered capsaicin. Results TRPV1 channels are expressed in preadipocytes but not in adipocytes. In preadipocytes, both capsaicin and RTX stimulate Ca2+ influx in dose-dependent manner. This stimulation may be prevented by capsazepine, a TRPV1 antagonist. At lower doses, capsaicin inhibits lipid accumulation and stimulates TRPV1 gene expression, while at higher doses it enhances accumulation of lipids and suppresses expression of its receptor. In doses of 0.1–100 µM, capsaicin promotes expression of major pro-adipogenic factor PPARγ and some of its downstream targets. In concentrations of 1 µM, capsaicin up-regulates anti-adipogenic genes. Low-dose capsaicin treatment of 3T3-L1 preadipocytes differentiating into adipocytes results in increased expression of brown fat cell marker genes. In white adipose of mice, capsaicin administration leads to increase in browning-specific genes. Global TRPV1 ablation (i.p. by RTX administration) leads to increase in locomotor activity with no change in body weight. Conclusion Our findings suggest the dual modulatory role of capsaicin in adipogenesis. Capsaicin inhibits adipogenesis in 3T3-L1 via TRPV1 activation and

  6. Curl flux induced drift in stochastic differential equations in the zero-mass limit

    NASA Astrophysics Data System (ADS)

    Wang, Jinhua; Yuan, Bo

    2016-11-01

    We consider the nonlinear stochastic dynamics of dissipative Hamiltonian systems with state-dependent friction and diffusion connected by the fluctuation-dissipation relation in high dimensions. The system under study has a close connection to Ao's framework in constructing a dynamical potential for non-equilibrium processes without detailed balance. We study the limiting case where the mass approaches zero and give a new and complete derivation of effective stochastic differential equations. Using the Ito stochastic integral convention, we show that the limiting effective Langevin equations have a new drift term. This extra term happens to be identical to the corresponding anti-Ito (or isothermal) integral (requiring constant temperature) in one dimension. We, however, cannot obtain this additional drift term using conventional stochastic integrals in high dimension. It is interesting to note that in a high-dimensional system, a curl flux induced drift may appear even if the diffusion matrix is constant. Our findings are supported by numerical simulations. We further analyze and discuss the role of this new drift term in calculating the classic escape time. For the first time, to our knowledge, the relation between the escape rate and the anti-Ito integral is presented. We also demonstrate that the derived diffusion equations give a new sampling algorithm which can increase convergence speed in a simple two-dimensional example.

  7. Genistein as an inducer of tumor cell differentiation : possible mechanisms of action.

    SciTech Connect

    Constantinou, A.; Huberman, E.; Center for Mechanistic Biology and Biotechnology; Univ. of Illinois at Chicago

    1995-01-01

    Decreased activity of either topoisomerases or tyrosine kinases has been implicated in the differentiation of a number of cell types. It is therefore conceivable that genistein, because of its reported ability to inhibit these activities in vitro, may be an inducer of cellular differentiation. We investigated this possibility in human promyelocytic HL-60 and erythroid K-562 leukemia cells and in human SK-MEL-131 melanoma cells. Our results indicated that genistein, in a dose-dependent manner, inhibited cell multiplication and induced cell differentiation. The maturing HL-60 cells acquired granulocytic and monocytic markers. The differentiating K-562 cells stained positively with benzidine, which indicates the production of hemoglobin, an erythroid marker. Following genistein treatment, maturing SK-MEL-131 melanoma cells formed dendrite-like structures and exhibited increased tyrosinase activity and melanin content. Experiments were designed to identify the molecular mechanism of genistein's action. Data from our laboratory suggest that this isoflavone triggers the pathway that leads to cellular differentiation by stabilizing protein-linked DNA strand breakage. Other possible mechanisms reported in the literature are discussed.

  8. Sphingomyelin metabolism is involved in the differentiation of MDCK cells induced by environmental hypertonicity

    PubMed Central

    Favale, Nicolás Octavio; Santacreu, Bruno Jaime; Pescio, Lucila Gisele; Marquez, Maria Gabriela; Sterin-Speziale, Norma Beatriz

    2015-01-01

    Sphingolipids (SLs) are relevant lipid components of eukaryotic cells. Besides regulating various cellular processes, SLs provide the structural framework for plasma membrane organization. Particularly, SM is associated with detergent-resistant microdomains. We have previously shown that the adherens junction (AJ) complex, the relevant cell-cell adhesion structure involved in cell differentiation and tissue organization, is located in an SM-rich membrane lipid domain. We have also demonstrated that under hypertonic conditions, Madin-Darby canine kidney (MDCK) cells acquire a differentiated phenotype with changes in SL metabolism. For these reasons, we decided to evaluate whether SM metabolism is involved in the acquisition of the differentiated phenotype of MDCK cells. We found that SM synthesis mediated by SM synthase 1 is involved in hypertonicity-induced formation of mature AJs, necessary for correct epithelial cell differentiation. Inhibition of SM synthesis impaired the acquisition of mature AJs, evoking a disintegration-like process reflected by the dissipation of E-cadherin and β- and α-catenins from the AJ complex. As a consequence, MDCK cells did not develop the hypertonicity-induced differentiated epithelial cell phenotype. PMID:25670801

  9. BMP-TAK1 (MAP3K7) Induces Adipocyte Differentiation Through PPARγ Signaling.

    PubMed

    Zhang, Yongchun; O'Keefe, Regis J; Jonason, Jennifer H

    2017-01-01

    BMPs have been shown to promote adipocyte differentiation through SMAD-dependent signaling. However, the role of TGF-β-activated kinase 1 (TAK1) in non-canonical BMP signaling in adipocyte differentiation remains unclear. Here, we show that TAK1 inhibition decreases lipid accumulation in C3H10T1/2 mesenchymal stem cells (MSCs) induced to differentiate into adipocytes. TAK1 knockdown by siRNA further confirms that TAK1 is required for adipocyte commitment of MSCs. Additionally, TAK1 knockdown inhibits adipogenesis of 3T3-L1 preadipocytes, indicating that TAK1 is not only needed for adipocyte commitment, but also required for adipocyte terminal differentiation. Furthermore, TAK1 ablation specifically in adipocytes reduced high fat diet-induced weight gain and improved glucose tolerance. Mechanistically, we demonstrate that TAK1 is required for PPARγ transactivation and promotes PPARγ transcriptional activity synergistically with TAK1 binding protein 1 (TAB1). Collectively, our results demonstrate that TAK1 plays a critical role in BMP-mediated adipocyte differentiation. J. Cell. Biochem. 118: 204-210, 2017. © 2016 Wiley Periodicals, Inc.

  10. XIAP inhibitors induce differentiation and impair clonogenic capacity of acute myeloid leukemia stem cells

    PubMed Central

    Moreno-Martínez, Daniel; Nomdedeu, Meritxell; Lara-Castillo, María Carmen; Etxabe, Amaia; Pratcorona, Marta; Tesi, Niccolò; Díaz-Beyá, Marina; Rozman, María; Montserrat, Emili; Urbano-Ispizua, Álvaro; Esteve, Jordi; Risueño, Ruth M.

    2014-01-01

    Acute myeloid leukemia (AML) is a neoplasia characterized by the rapid expansion of immature myeloid blasts in the bone marrow, and marked by poor prognosis and frequent relapse. As such, new therapeutic approaches are required for remission induction and prevention of relapse. Due to the higher chemotherapy sensitivity and limited life span of more differentiated AML blasts, differentiation-based therapies are a promising therapeutic approach. Based on public available gene expression profiles, a myeloid-specific differentiation-associated gene expression pattern was defined as the therapeutic target. A XIAP inhibitor (Dequalinium chloride, DQA) was identified in an in silico screening searching for small molecules that induce similar gene expression regulation. Treatment with DQA, similarly to Embelin (another XIAP inhibitor), induced cytotoxicity and differentiation in AML. XIAP inhibition differentially impaired cell viability of the most primitive AML blasts and reduced clonogenic capacity of AML cells, sparing healthy mature blood and hematopoietic stem cells. Taken together, these results suggest that XIAP constitutes a potential target for AML treatment and support the evaluation of XIAP inhibitors in clinical trials. PMID:24952669

  11. Protective effect of Clostridium tyrobutyricum in acute dextran sodium sulphate-induced colitis: differential regulation of tumour necrosis factor-α and interleukin-18 in BALB/c and severe combined immunodeficiency mice

    PubMed Central

    Hudcovic, T; Kolinska, J; Klepetar, J; Stepankova, R; Rezanka, T; Srutkova, D; Schwarzer, M; Erban, V; Du, Z; Wells, J M; Hrncir, T; Tlaskalova-Hogenova, H; Kozakova, H

    2012-01-01

    One of the promising approaches in the therapy of ulcerative colitis is administration of butyrate, an energy source for colonocytes, into the lumen of the colon. This study investigates the effect of butyrate producing bacterium Clostridium tyrobutyricum on dextran sodium sulphate (DSS)-induced colitis in mice. Immunocompetent BALB/c and immunodeficient severe combined immunodeficiency (SCID) mice reared in specific-pathogen-free (SPF) conditions were treated intrarectally with C. tyrobutyricum 1 week prior to the induction of DSS colitis and during oral DSS treatment. Administration of DSS without C. tyrobutyricum treatment led to an appearance of clinical symptoms – bleeding, rectal prolapses and colitis-induced increase in the antigen CD11b, a marker of infiltrating inflammatory cells in the lamina propria. The severity of colitis was similar in BALB/c and SCID mice as judged by the histological damage score and colon shortening after 7 days of DSS treatment. Both strains of mice also showed a similar reduction in tight junction (TJ) protein zonula occludens (ZO)-1 expression and of MUC-2 mucin depression. Highly elevated levels of cytokine tumour necrosis factor (TNF)-α in the colon of SCID mice and of interleukin (IL)-18 in BALB/c mice were observed. Intrarectal administration of C. tyrobutyricum prevented appearance of clinical symptoms of DSS-colitis, restored normal MUC-2 production, unaltered expression of TJ protein ZO-1 and decreased levels of TNF-α and IL-18 in the descending colon of SCID and BALB/c mice, respectively. Some of these features can be ascribed to the increased production of butyrate in the lumen of the colon and its role in protection of barrier functions and regulation of IL-18 expression. PMID:22236013

  12. Moesin signalling induces F9 teratocarcinoma cells to differentiate into primitive extraembryonic endoderm.

    PubMed

    Krawetz, Roman; Kelly, Gregory M

    2008-01-01

    The mouse F9 teratocarcinoma cell line is a model that can be manipulated to imitate one of the earliest epithelial-mesenchymal transitions in mouse development. When cells are treated with Retinoic Acid they differentiate into primitive endoderm and into parietal endoderm with the addition of dibutyryl cAMP. Parietal endoderm also develops when undifferentiated cells express a constitutively active (CA) form of Galpha13(Q226L). Differentiation is accompanied by a translocation of beta-catenin to the nucleus and considerable changes to the cytoskeleton and cell morphology. ERM proteins facilitate rearrangements to the F-actin cytoskeleton, and at least one, moesin, is essential for cell survival. In this study we found that moesin translocated to the nucleus during RA-induced differentiation, and sequence analysis identified putative nuclear localization signals in the protein. In the absence of RA, transient over-expression of rat moesin or the distantly related zebrafish homologue in F9 cells induced primitive endoderm. Furthermore, no apparent beta-catenin was seen in the nucleus of cells over-expressing zebrafish moesin. Our previous results have shown that depleting F9 cells of moesin using an antisense morpholino strategy caused them to detach from the substrate unless they expressed CA-Galpha13(Q226L). This CA-Galpha13 signalling maintained cell survival, but at the expense of differentiation. We now report that over-expressing zebrafish moesin in mouse moesin-depleted F9 cells not only ensured cell survival, but also induced differentiation to primitive endoderm. Together, the results suggest a new role for moesin, acting in a signalling pathway facilitating the differentiation of extraembryonic endoderm.

  13. Human TNF-α induces differential protein phosphorylation in Schistosoma mansoni adult male worms.

    PubMed

    Oliveira, Katia C; Carvalho, Mariana L P; Bonatto, José Matheus C; Schechtman, Debora; Verjovski-Almeida, Sergio

    2016-02-01

    Schistosoma mansoni and its vertebrate host have a complex and intimate connection in which several molecular stimuli are exchanged and affect both organisms. Human tumor necrosis factor alpha (hTNF-α), a pro-inflammatory cytokine, is known to induce large-scale gene expression changes in the parasite and to affect several parasite biological processes such as metabolism, egg laying, and worm development. Until now, the molecular mechanisms for TNF-α activity in worms are not completely understood. Here, we aimed at exploring the effect of hTNF-α on S. mansoni protein phosphorylation by 2D gel electrophoresis followed by a quantitative analysis of phosphoprotein staining and protein identification by mass spectrometry. We analyzed three biological replicates of adult male worms exposed to hTNF-α and successfully identified 32 protein spots with a statistically significant increase in phosphorylation upon in vitro exposure to hTNF-α. Among the differentially phosphorylated proteins, we found proteins involved in metabolism, such as glycolysis, galactose metabolism, urea cycle, and aldehyde metabolism, as well as proteins related to muscle contraction and to cytoskeleton remodeling. The most differentially phosphorylated protein (30-fold increase in phosphorylation) was 14-3-3, whose function is known to be modulated by phosphorylation, belonging to a signal transduction protein family that regulates a variety of processes in all eukaryotic cells. Further, 75% of the identified proteins are known in mammals to be related to TNF-α signaling, thus suggesting that TNF-α response may be conserved in the parasite. We propose that this work opens new perspectives to be explored in the study of the molecular crosstalk between host and pathogen.

  14. Arachidonic acid enhances TPA-induced differentiation in human leukemia HL-60 cells via reactive oxygen species-dependent ERK activation.

    PubMed

    Chien, Chih-Chiang; Wu, Ming-Shun; Shen, Shing-Chuan; Yang, Liang-Yo; Wu, Wen-Shin; Chen, Yen-Chou

    2013-04-01

    The phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA), is a potent stimulator of differentiation in human leukemia cells; however, the effects of arachidonic acid (AA) on TPA-induced differentiation are still unclear. In the present study, we investigated the contribution of AA to TPA-induced differentiation of human leukemia HL-60 cells. We found that treatment of HL-60 cells with TPA resulted in increases in cell attachment and nitroblue tetrazolium (NBT)-positive cells, which were significantly enhanced by the addition of AA. Stimulation of TPA-induced intracellular reactive oxygen species (ROS) production by AA was detected in HL-60 cells via a DCHF-DA analysis, and the addition of the antioxidant, N-acetyl-cysteine (NAC), was able to reduce TPA+AA-induced differentiation in accordance with suppression of intracellular peroxide elevation by TPA+AA. Furthermore, activation of extracellular-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) by TPA+AA was identified in HL-60 cells, and the ERK inhibitor, PD98059, but not the JNK inhibitor, SP600125, inhibited TPA+AA-induced NBT-positive cells. Suppression of TPA+AA-induced ERK protein phosphorylation by PD98059 and NAC was detected, and AA enhanced ERK protein phosphorylation by TPA was in HL-60 cells. AA clearly increased TPA-induced HL-60 cell differentiation, as evidenced by a marked increase in CD11b expression, which was inhibited by NAC and PD98059 addition. Eicosapentaenoic acid (EPA) as well as AA showed increased intracellular peroxide production and differentiation of HL-60 cells elicited by TPA. Evidence of AA potentiation of differentiation by TPA in human leukemia cells HL-60 via activation of ROS-dependent ERK protein phosphorylation was first demonstrated herein.

  15. Application of Green Tea Catechin for Inducing the Osteogenic Differentiation of Human Dedifferentiated Fat Cells in Vitro.

    PubMed

    Kaida, Koji; Honda, Yoshitomo; Hashimoto, Yoshiya; Tanaka, Masahiro; Baba, Shunsuke

    2015-11-25

    Despite advances in stem cell biology, there are few effective techniques to promote the osteogenic differentiation of human primary dedifferentiated fat (DFAT) cells. We attempted to investigate whether epigallocatechin-3-gallate (EGCG), the main component of green tea catechin, facilitates early osteogenic differentiation and mineralization on DFAT cells in vitro. DFAT cells were treated with EGCG (1.25-10 μM) in osteogenic medium (OM) with or without 100 nM dexamethasone (Dex) for 12 days (hereafter two osteogenic media were designated as OM(Dex) and OM). Supplementation of 1.25 μM EGCG to both the media effectively increased the mRNA expression of collagen 1 (COL1A1) and runt-related transcription factor 2 (RUNX2) and also increased proliferation and mineralization. Compared to OM(Dex) with EGCG, OM with EGCG induced earlier expression for COL1A1 and RUNX2 at day 1 and higher mineralization level at day 12. OM(Dex) with 10 μM EGCG remarkably hampered the proliferation of the DFAT cells. These results suggest that OM(without Dex) with EGCG might be a preferable medium to promote proliferation and to induce osteoblast differentiation of DFAT cells. Our findings provide an insight for the combinatory use of EGCG and DFAT cells for bone regeneration and stem cell-based therapy.

  16. Application of Green Tea Catechin for Inducing the Osteogenic Differentiation of Human Dedifferentiated Fat Cells in Vitro

    PubMed Central

    Kaida, Koji; Honda, Yoshitomo; Hashimoto, Yoshiya; Tanaka, Masahiro; Baba, Shunsuke

    2015-01-01

    Despite advances in stem cell biology, there are few effective techniques to promote the osteogenic differentiation of human primary dedifferentiated fat (DFAT) cells. We attempted to investigate whether epigallocatechin-3-gallate (EGCG), the main component of green tea catechin, facilitates early osteogenic differentiation and mineralization on DFAT cells in vitro. DFAT cells were treated with EGCG (1.25–10 μM) in osteogenic medium (OM) with or without 100 nM dexamethasone (Dex) for 12 days (hereafter two osteogenic media were designated as OM(Dex) and OM). Supplementation of 1.25 μM EGCG to both the media effectively increased the mRNA expression of collagen 1 (COL1A1) and runt-related transcription factor 2 (RUNX2) and also increased proliferation and mineralization. Compared to OM(Dex) with EGCG, OM with EGCG induced earlier expression for COL1A1 and RUNX2 at day 1 and higher mineralization level at day 12. OM(Dex) with 10 μM EGCG remarkably hampered the proliferation of the DFAT cells. These results suggest that OM(without Dex) with EGCG might be a preferable medium to promote proliferation and to induce osteoblast differentiation of DFAT cells. Our findings provide an insight for the combinatory use of EGCG and DFAT cells for bone regeneration and stem cell-based therapy. PMID:26602917

  17. Cisplatin Induces Resistance by Triggering Differentiation of Testicular Embryonal Carcinoma Cells

    PubMed Central

    Abada, Paolo B.; Howell, Stephen B.

    2014-01-01

    Although testicular germ cell tumors are generally quite responsive to treatment with cisplatin, a small fraction of them acquire resistance during therapy. Even when cisplatin treatment is successful the patient is often left with a residual teratoma at the site of the primary tumor suggesting that cisplatin may trigger differentiation in some tumors. Using the human embryonal carcinoma cell line NTera2/D1, we confirmed that exposure to the differentiating agent retinoic acid produced a reduction in pluripotency markers NANOG and POU5F1 (Oct3/4) and an acute concentration-dependent increase in resistance to both cisplatin and paclitaxel that reached as high as 18-fold for cisplatin and 61-fold for paclitaxel within four days. A two day exposure to cisplatin also produced a concentration-dependent decrease in the expression of the NANOG and POU5F1 and increased expression of three markers whose levels increase with differentiation including Nestin, SCG10 and Fibronectin. In parallel, exposure to cisplatin induced up to 6.2-fold resistance to itself and 104-fold resistance to paclitaxel. Paclitaxel did not induce differentiation or resistance to either itself or cisplatin. Neither retinoic acid nor cisplatin induced resistance in cervical or prostate cancer cell lines or other germ cell tumor lines in which they failed to alter the expression of NANOG and POU5F1. Forced expression of NANOG prevented the induction of resistance to cisplatin by retinoic acid. We conclude that cisplatin can acutely induce resistance to itself and paclitaxel by triggering a differentiation response in pluripotent germ cell tumor cells. PMID:24475288

  18. Cisplatin induces resistance by triggering differentiation of testicular embryonal carcinoma cells.

    PubMed

    Abada, Paolo B; Howell, Stephen B

    2014-01-01

    Although testicular germ cell tumors are generally quite responsive to treatment with cisplatin, a small fraction of them acquire resistance during therapy. Even when cisplatin treatment is successful the patient is often left with a residual teratoma at the site of the primary tumor suggesting that cisplatin may trigger differentiation in some tumors. Using the human embryonal carcinoma cell line NTera2/D1, we confirmed that exposure to the differentiating agent retinoic acid produced a reduction in pluripotency markers NANOG and POU5F1 (Oct3/4) and an acute concentration-dependent increase in resistance to both cisplatin and paclitaxel that reached as high as 18-fold for cisplatin and 61-fold for paclit