Hypoxia stimulates proliferation of rat neural stem cells with influence on the expression of cyclin D1 and c-Jun N-terminal protein kinase signaling pathway in vitro

Chen, X.; Tian, Yi; Yao, Libo; Zhang, J.; Liu, Y.

doi:10.1016/j.neuroscience.2009.11.007

Cited by 56 publications

(49 citation statements)

References 57 publications

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“…It has been suggested that RhoA activation regulates cardiac contractility and gene expression through the MAPK superfamily [28,37] . Recent studies [12,38,39] demonstrated that JNK is an important mediator of the fibrotic process. As a downstream target of JNK, c-Jun acts as transcription factor for numerous genes, and overexression of these genes is often associated with organ fibrosis.…”

Section: Discussionmentioning

confidence: 99%

Involvement of RhoA/ROCK in myocardial fibrosis in a rat model of type 2 diabetes

Zhou

Wang

et al. 2011

Acta Pharmacol Sin

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Aim: To investigate whether activation of RhoA/Rho kinase (ROCK) is involved in myocardial fibrosis in diabetic hearts. Methods: A rat model of type 2 diabetes was established using high fat diet combined with streptozotocin (30 mg/kg, ip). Animals were randomly divided into 3 groups: control rats, untreated diabetic rats that received vehicle and treated diabetic rats that received Rhokinase inhibitor fasudil hydrochloride hydrate (10 mg·kg -1 ·d -1 , ip, for 14 weeks). Cardiac contractile function was evaluated in vivo. The morphological features of cardiac fibrosis were observed using immunohistochemistry and TEM. The mRNA expression of JNK, TGFβ1, type-I, and type-III procollagen was assessed with RT-PCR. The phosphorylation of MYPT1, JNK and Smad2/3, as well as the protein levels of TGFβ1 and c-Jun, were evaluated using Western blotting. Results: In untreated diabetic rats, myocardial fibrosis was developed and the heart contractility was significantly reduced as compared to the control rats. In the hearts of untreated diabetic rats, the mRNA expression level and activity of JNK were upregulated; the expression of TGFβ1 and phosphorylation of Smad2/3 were increased. In the hearts of treated diabetic rat, activation of JNK and TGFβ/Smad was significantly decreased, myocardial fibrosis was reduced, and cardiac contractile function improved. Conclusion: The data suggest that fasudil hydrochloride hydrate ameliorates myocardial fibrosis in rats with type 2 diabetes at least in part through inhibiting the JNK and TGFβ/Smad pathways. Inhibition of RhoA/ROCK may be a novel therapeutic target for prevention of diabetic cardiomyopathy.

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Section: Discussionmentioning

confidence: 99%

Involvement of RhoA/ROCK in myocardial fibrosis in a rat model of type 2 diabetes

Zhou

Wang

et al. 2011

Acta Pharmacol Sin

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“…Lowering the O 2 level in cell culture has been shown to increase the proliferation rate of NSCs, but the final levels of O 2 and the kinetics of equilibration of the gaseous atmosphere and the culture medium were not carefully controlled or reported (12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23). Tanks with premeasured amounts of O 2 at 0.1, 1, or 20% were used to perfuse sealed incubator chambers.…”

Section: Measurement Of O 2 Levels In the Medium Of Nsc Cultures-mentioning

confidence: 99%

“…The lung alveoli and bloodstream typically hold ϳ14% (4, 5) and 11.5% (6 -8) O 2 , respectively, and O 2 levels in various areas of the brain range from 0.1 to 9% (5, 7, 9 -12). Recent studies have shown that the use of lower O 2 levels in culture results in increased rates of proliferation of neural stem/progenitor cells (NSCs) 2 from various embryonic or adult brain regions (12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23), virally immortalized human NSCs (23), and embryonic stem (ES) cells (3,24,25) and that these O 2 levels can also influence the differentiation of NSCs (9 -16).…”

mentioning

confidence: 99%

Matrix Metalloproteinase (MMP)-9 Induced by Wnt Signaling Increases the Proliferation and Migration of Embryonic Neural Stem Cells at Low O2 Levels

Ingraham

Park

Makarenkova

et al. 2011

Journal of Biological Chemistry

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Recent studies have shown that various neural and embryonic stem cells cultured in 1-8% oxygen (O 2 ), levels lower than those typically used in cell culture (20.9%), displayed increased rates of proliferation; however, the molecular mechanisms underlying these changes are largely undefined. In this study, using rigorously controlled O 2 levels, we found that neural stem cells (NSCs) from embryonic day 15 rat cortex increased their rate of proliferation and migration in 1% O 2 relative to 20% O 2 without changes in viability. We sought to identify molecular changes in NSCs grown in 1% O 2 that might account for these increases. In 1% O 2 , levels of the hypoxia-inducible transcription factor HIF-1␣ were transiently increased. Reduced adherence of NSCs in 1% O 2 to basement membrane-coated plates was observed, and quantitative RT-PCR analysis confirmed that the levels of mRNA for an assortment of cell adhesion and extracellular matrix molecules were altered. Most notable was a 5-fold increase in matrix metalloproteinase (MMP)-9 mRNA. Specific inhibition of MMP-9 activity, verified using a fluorescent substrate assay, prevented the increase in proliferation and migration in 1% O 2 . The canonical Wnt pathway was recently shown to be activated in stem cells in low O 2 via HIF-1␣. Inhibition of Wnt signaling by DKK-1 also prevented the increase in proliferation, migration, and MMP-9 expression. Thus, MMP-9 is a key molecular effector, downstream of HIF-1␣ and Wnt activation, responsible for increased rates of NSC proliferation and migration in 1% O 2 .A frequently overlooked variable for the in vitro expansion of stem/progenitor cells is the level of O 2 in cell culture (1-3). In fact, the level of O 2 (20.9% O 2 ) used for in vitro culture is hyperoxic for cells in vivo. The lung alveoli and bloodstream typically hold ϳ14% (4, 5) and 11.5% (6 -8) O 2 , respectively, and O 2 levels in various areas of the brain range from 0.1 to 9% (5, 7, 9 -12). Recent studies have shown that the use of lower O 2 levels in culture results in increased rates of proliferation of neural stem/progenitor cells (NSCs) 2 from various embryonic or adult brain regions (12-23), virally immortalized human NSCs (23), and embryonic stem (ES) cells (3,24,25) and that these O 2 levels can also influence the differentiation of NSCs (9 -16).A large body of work has described hypoxia-inducible transcription factors as key components of the O 2 -sensing machinery that responds to lowered O 2 in cells and organisms (5,10,26,27). It has been shown that levels of HIF-1␣ protein can vary significantly over physiological ranges of O 2 (28). Although HIF-1␣ is constitutively expressed, when O 2 levels are high, the protein is hydroxylated by a family of prolyl hydroxylase enzymes, catalyzing a modification that targets HIF-1␣ for proteasomal degradation. At lower O 2 levels, the HIF-1␣ protein undergoes less hydroxylation, is stabilized, and can then translocate to the nucleus where it activates several genes that modulate the cellular response to decreas...

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“…The culture system was used to conduct the following experiments. To identify H 2 O 2 -induced NSC injury, MTT assay was carried out as previously described [17]. As expected, H 2 O 2 significantly damaged cell viability in cultured NSCs in time-and concentration-dependent manners (Fig.…”

Section: Activation Of Mglur4 Increased Nscs Viability Upon H 2 O 2 Imentioning

confidence: 84%

“…Rat cortical NSCs were prepared from E15.5 SpragueDawley rat embryos as previously described and with minor modification [17]. Briefly, the cortex was carefully dissected in chilled sterile phosphate-buffered saline (PBS) and incubated with 0.05% trypsin and 200 mM EDTA in PBS at 37°C for 10 min.…”

Section: Rat Cortical Nsc Culturementioning

confidence: 99%

Activation of Type 4 Metabotropic Glutamate Receptor Attenuates Oxidative Stress-Induced Death of Neural Stem Cells with Inhibition of JNK and p38 MAPK Signaling

Zhang

Wang

et al. 2015

Stem Cells and Development

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1Promoting both endogenous and exogenous neural stem cells' (NSCs) survival in the hostile host environments is essential to cell replacement therapy for central nervous system (CNS) disorders. Type 4 metabotropic glutamate receptor (mGluR4), one of the members of mGluRs, has been shown to protect neurons from acute and chronic excitotoxic insults in various brain damages. The present study investigated the preventive effects of mGluR4 on NSC injury induced by oxidative stress. Under challenge with H 2 O 2 , loss of cell viability was observed in cultured rat NSCs, and treatment with selective mGluR4 agonist VU0155041 conferred protective effects against the loss of cellular viability in a concentration-dependent manner, as shown by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Pretreatment of VU0155041 (30 mM) also inhibited the excessive NSC death induced by H 2 O 2 , and group III mGluRs antagonist (RS)-a-methylserine-O-phosphate (MSOP) or gene-targeted knockdown abolished the protective action of mGluR4, indicated by propidium iodide-Hoechst and terminal deoxynucleotidyl transferase-mediated UTP nick end labeling (TUNEL) staining. Western blot assay demonstrated that mGluR4 activation reversed the decreased procaspase-8/9/3and the destructed Bcl-2/Bax expressing balance, and likewise, MSOP and mGluR4 knockdown abrogated the action of mGluR4 activity. Furthermore, inhibition of JNK and p38 mitogen-activated protein kinases (MAPKs) were observed after mGluR4 activation, and as paralleling control, JNK-specific inhibitor SP600125 and p38-specific inhibitor SB203580 significantly rescued the H 2 O 2 -mediated NSC apoptosis and cleavage of procaspase-3. We suggest that activation of mGluR4 prevents oxidative stress-induced NSC death and apoptotic-associated protein activities with involvement of inhibiting the JNK and p38 pathways in cell culture. Our findings may help to develop strategies for enhancing the resided and transplanted NSC survival after oxidative stress insult of CNS.

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Hypoxia stimulates proliferation of rat neural stem cells with influence on the expression of cyclin D1 and c-Jun N-terminal protein kinase signaling pathway in vitro

Cited by 56 publications

References 57 publications

Involvement of RhoA/ROCK in myocardial fibrosis in a rat model of type 2 diabetes

Involvement of RhoA/ROCK in myocardial fibrosis in a rat model of type 2 diabetes

Matrix Metalloproteinase (MMP)-9 Induced by Wnt Signaling Increases the Proliferation and Migration of Embryonic Neural Stem Cells at Low O2 Levels

Activation of Type 4 Metabotropic Glutamate Receptor Attenuates Oxidative Stress-Induced Death of Neural Stem Cells with Inhibition of JNK and p38 MAPK Signaling

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