249. Regulated expression of KIT protein in juvenile and adult germ cells of the rodent testis

2008 ◽  
Vol 20 (9) ◽  
pp. 49
Author(s):  
S. Mithraprabhu ◽  
C. W. Brown ◽  
M. M. Matzuk ◽  
K. L. Loveland
Keyword(s):  
Protein Expression ◽  
Germ Cells ◽  
Wild Type Mouse ◽  
Erythroid Differentiation ◽  
Activin A ◽  
Mrna Levels ◽  
Wild Type ◽  
Kit Receptor ◽  
Murine Erythroleukemia

KIT receptor is an established marker of differentiating spermatogonia and its activation is required to trigger spermatogonial maturation. KIT mRNA, however, can be detected in undifferentiated spermatogonia in the absence of protein expression, as previously established by us in the irradiated adult rat testes [1]. This differential regulation of mRNA and protein is presumably modulated by either local hormone action or by cues from the adult testicular microenvironment. Endogenous regulatory factors known to stimulate KIT synthesis in juvenile male germ cells in vitro are bone morphogenetic protein 4 (BMP4) and retinoic acid (RA), while factors known to suppress KIT at the onset of spermatogenesis have not yet been identified. Activin A, implicated in KIT downregulation in a murine erythroleukemia cell line [2], is produced within the juvenile mammalian testis and influences activities of spermatogonia and Sertoli cells. We hypothesised that activin acts to repress KIT expression in spermatogonia and therefore modulate spermatogonial behaviour. Evidence for this was first derived from Sertoli and germ cell co-cultures of day 8 wild type mouse testes in which exogenous activin addition caused a dose-dependent reduction of KIT mRNA. Whole testes mRNA analyses of two activin transgenic mouse models, the newborn Inhba−/− (lacking activin A) and postnatal InhbaBK/BK (decreased bioactive activin), revealed a significant elevation in KIT expression relative to wild type littermates. In the postnatal day 7 InhbaBK/BK testes, an elevated proportion of differentiated spermatogonia, increased cell surface KIT protein levels, enhanced mRNA levels of a known downstream target of KIT signalling pathway, cyclind3 and a meiotic marker, Sycp3, were observed. These data provide the first comprehensive evidence for activin modulation of KIT expression at spermatogenesis onset, in germ cells of the juvenile testis. This finding is of fundamental importance to other KIT-dependent processes. (1) Prabhu, S.M., et al. Expression of c-Kit receptor mRNA and protein in the developing, adult and irradiated rodent testis. Reproduction, 2006. 131(3): p. 489–99. (2) Hino, M., et al. Down-modulation of c-kit mRNA and protein expression by erythroid differentiation factor/activin A. FEBS Lett, 1995. 374(1): p. 69–71.

Truncated Human EpoR Causes Polycythemia in Fetal Erythropoiesis through Stat5 Hyperactivation.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 567-567 ◽  
Author(s):  
Donghoon Yoon ◽  
Stephanie S. Watowich ◽  
Josef T. Prchal
Keyword(s):  
Peripheral Blood ◽  
Fetal Liver ◽  
Wild Type Mouse ◽  
Erythroid Differentiation ◽  
T Test ◽  
Erythropoietin Receptor ◽  
Wild Type ◽  
Erythroid Progenitors ◽  
Fetal Erythropoiesis

Abstract Gain-of-function mutations causing truncations of the cytoplasmic domain of the human erythropoietin receptor (EPOR) result in a dominantly inherited disorder-primary familiar congenital polycythemia. The consequence of EpoR truncation is polycythemia and in vitro hypersensitivity of erythroid precursors to erythropoietin (Epo). We have replaced the murine EpoR gene with a wild-type human EPOR (whEPOR) gene or a mutant human EPOR gene (mthEPOR) that we initially identified in a family with polycythemia. This mutation produces a truncated EpoR mutant with deleted cytoplasmic C-terminal domain after the first tyrosine residue of the intracellular domain. We reported that the mice containing mthEPOR allele have polycythemia and the adult whEPOR mice have anemia. To study the effects of these genotypes on fetal erythropoiesis, we examined fetuses E14.5 homozygotes wild type mouse EpoR, and human EPOR alleles. Hematocrit results show: MthEPOR fetuses were polycythemic compared to mouse EpoR (mthEPOR vs mouse EpoR; 34.58 ± 1.24 % vs 27.49 ± 0.90 %, P<0.001 by t-test), and whEPOR were anemic (whEPOR vs mouse EpoR; 18.61 ± 0.79 % vs 27.49 ± 0.89 %, P<0.001 by t-test). To study the pathophysiology of these phenotypes, we analyzed the erythroid differentiation using differential expression of CD71 and TER119 surface antigens by FACS in the fetal liver cells (FLs). FLs from mthEPOR homozygote had increased population on early and late basophilic erythroblast stage compared to mouse EpoR, but the populations of differentiated erythroid progenitors from mthEPOR homozygote were significantly lower than mouse EpoR and whEPOR homozygotes. We proposed that the erythroid progenitors from mthEPOR exit fetal liver to fetal blood circulation prematurely. The peripheral blood from mthEPOR and mouse EpoR s was analyzed by morphology and FACS. We show that the majority of population in peripheral blood from mthEPOR homozygote were earlier erythroid progenitors (high CD71/low TER119 population in mthEPOR 47.53 %, vs 13.14 % mouse EpoR; high CD71/high TER119 population from mthEPOR 11.49 % vs 65.00 % mouse EpoR). To evaluate the Epo signal transduction we tested the kinetics and dose responses of Epo at Stat5 phosphorylation level. The mthEPOR expressing FLs showed a markedly increased and sustained Epo sensitivity compared to mouse EpoR expressing FLs. In contrast, in whEPOR expressing FLs, Stat5 phosphorylation was significantly lower even at the highest concentration of Epo. We conclude that mthEPOR causes fetal polycythemia and is associated with premature exit of early erythroid progenitors from fetal liver to fetal circulation. In contrast whEPOR is associated with more severe anemia than we observed in adult erythropoiesis. The degree of Epo induced Stat5 activation plays an important role in generation of anemic and polycythemic phenotypes.

scholarly journals Estrogen Up-Regulates Hepatic Expression of Suppressors of Cytokine Signaling-2 and -3 in Vivo and in Vitro

Endocrinology ◽  
2004 ◽  
Vol 145 (12) ◽  
pp. 5525-5531 ◽  
Author(s):  
Gary M. Leong ◽  
Sofia Moverare ◽  
Jesena Brce ◽  
Nathan Doyle ◽  
Klara Sjögren ◽  
...  
Keyword(s):  
Promoter Activity ◽  
Hepatoma Cells ◽  
Cytokine Signaling ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Wild Type ◽  
Hepatic Expression ◽  
Suppressors Of Cytokine Signaling

Abstract Suppressors of cytokine signaling (SOCS) are important negative regulators of cytokine action. We recently reported that estrogen stimulates SOCS-2 expression and inhibits GH signaling in kidney cells. The effects of estrogen on SOCS expression in other tissues are unclear. The aim of this study was to investigate in vivo and in vitro whether estrogen affected SOCS expression in the liver, a major target organ of GH. The in vivo hepatic effects of estrogen on ovariectomized mice lacking estrogen receptor (ER)-α, ERβ, or both and their wild-type littermates were examined by DNA microarray analysis. In vitro, the effects of estrogen on SOCS expression in human hepatoma cells were examined by reverse transcription quantitative PCR. Long-term (3 wk) estrogen treatment induced a 2- to 3-fold increase in hepatic expression of SOCS-2 and -3 in wild-type and ERβ knockout mice but not in those lacking ERα or both ER subtypes. Short-term treatment (at 24 h) increased the mRNA level of SOCS-3 but not SOCS-2. In cultured hepatoma cells, estrogen increased SOCS-2 and -3 mRNA levels by 2-fold in a time- and dose-dependent manner (P &lt; 0.05). Estrogen induced murine SOCS-3 promoter activity by 2-fold (P &lt; 0.05) in constructs containing a region between nucleotides −1862 and −855. Moreover, estrogen and GH had additive effects on the SOCS-3 promoter activity. In summary, estrogen, via ERα, up-regulated hepatic expression of SOCS-2 and -3, probably through transcriptional activation. This indicates a novel mechanism of estrogen regulation of cytokine action.

Transmembrane prolyl 4-hydroxylase is a fourth prolyl 4-hydroxylase regulating EPO production and erythropoiesis

Blood ◽  
2012 ◽  
Vol 120 (16) ◽  
pp. 3336-3344 ◽  
Author(s):  
Anu Laitala ◽  
Ellinoora Aro ◽  
Gail Walkinshaw ◽  
Joni M. Mäki ◽  
Maarit Rossi ◽  
...  
Keyword(s):  
Cultured Cells ◽  
Mrna Level ◽  
Hypoxia Inducible Factor ◽  
Mrna Levels ◽  
Wild Type ◽  
Α Subunit ◽  
Hepcidin Expression ◽  
In The Wild ◽  
Hepcidin Mrna

AbstractAn endoplasmic reticulum transmembrane prolyl 4-hydroxylase (P4H-TM) is able to hydroxylate the α subunit of the hypoxia-inducible factor (HIF) in vitro and in cultured cells, but nothing is known about its roles in mammalian erythropoiesis. We studied such roles here by administering a HIF-P4H inhibitor, FG-4497, to P4h-tm−/− mice. This caused larger increases in serum Epo concentration and kidney but not liver Hif-1α and Hif-2α protein and Epo mRNA levels than in wild-type mice, while the liver Hepcidin mRNA level was lower in the P4h-tm−/− mice than in the wild-type. Similar, but not identical, differences were also seen between FG-4497–treated Hif-p4h-2 hypomorphic (Hif-p4h-2gt/gt) and Hif-p4h-3−/− mice versus wild-type mice. FG-4497 administration increased hemoglobin and hematocrit values similarly in the P4h-tm−/− and wild-type mice, but caused higher increases in both values in the Hif-p4h-2gt/gt mice and in hematocrit value in the Hif-p4h-3−/− mice than in the wild-type. Hif-p4h-2gt/gt/P4h-tm−/− double gene-modified mice nevertheless had increased hemoglobin and hematocrit values without any FG-4497 administration, although no such abnormalities were seen in the Hif-p4h-2gt/gt or P4h-tm−/− mice. Our data thus indicate that P4H-TM plays a role in the regulation of EPO production, hepcidin expression, and erythropoiesis.

scholarly journals Effects of CREG1 on Age-Associated Metabolic Phenotypes and Renal Senescence in Mice

2021 ◽  
Vol 22 (3) ◽  
pp. 1276
Author(s):  
Michihiro Hashimoto ◽  
Ayumi Goto ◽  
Yuki Endo ◽  
Masataka Sugimoto ◽  
Jun Ueda ◽  
...  
Keyword(s):  
Renal Dysfunction ◽  
Body Weight Gain ◽  
Mrna Levels ◽  
Wild Type ◽  
Metabolic Phenotypes ◽  
Age Related ◽  
Secretory Phenotype ◽  
Filtering Function ◽  
Renal Senescence

Cellular repressor of E1A-stimulated genes 1 (CREG1) is a secreted glycoprotein that accelerates p16-dependent cellular senescence in vitro. We recently reported the ability of CREG1 to stimulate brown adipogenesis using adipocyte P2-CREG1-transgenic (Tg) mice; however, little is known about the effect of CREG1 on aging-associated phenotypes. In this study, we investigated the effects of CREG1 on age-related obesity and renal dysfunction in Tg mice. Increased brown fat formation was detected in aged Tg mice, in which age-associated metabolic phenotypes such as body weight gain and increases in blood glucose were improved compared with those in wild-type (WT) mice. Blood CREG1 levels increased significantly in WT mice with age, whereas the age-related increase was suppressed, and its levels were reduced, in the livers and kidneys of Tg mice relative to those in WT mice at 25 months. Intriguingly, the mRNA levels of Ink4a, Arf, and senescence-associated secretory phenotype (SASP)-related genes and p38MAPK activity were significantly lowered in the aged kidneys of Tg mice, in which the morphological abnormalities of glomeruli as well as filtering function seen in WT kidneys were alleviated. These results suggest the involvement of CREG1 in kidney aging and its potential as a target for improving age-related renal dysfunction.

P–803 Novel culture conditions for the improvement of the in vitro expansion of human male fetal germ cells

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
M Martin ◽  
M Ferreira ◽  
J Taelman ◽  
C Eguizabal ◽  
S M Chuv. d. Sous. Lopes
Keyword(s):  
Growth Factors ◽  
Germ Cells ◽  
Activin A ◽  
Culture Conditions ◽  
Media Culture ◽  
Germline Stem Cell ◽  
Growth Media ◽  
Human Male ◽  
In Vitro Expansion

Abstract Study question Do different ECMs/substrates and growth media culture conditions improve in vitro male human primordial germ cell (hPGC) expansion? Summary answer We achieved in vitro expansion improvement of male hPGCs with specific growth factors such as LIF, EGF, FGF2 and GDNF on gelatin- and vitronectin-coating cultures. What is known already PGCs are the precursors of male and female gametes, which are specified during early mammalian post-implantation embryonic development. PGCs undergo sequential cell divisions to differentiate into pro-spermatogonia (pSPG). In vitro propagation of pSPG could be important to understand the transition to spermatogonial stem cells (SSCs), important for fertility preservation in patients with infertility. Here, we aimed at performing a comparative analysis on in vitro feeder-free culture systems, based on different extracellular matrix (ECM) and growth media culture conditions, to support the expansion of the male germline stem cell populations using second trimester human male gonads as primary material. Study design, size, duration We collected human 2nd trimester male fetal gonads from elective abortions. Male gonads were dissected in saline solution (0.9% NaCl) and were either fixed overnight in 4% paraformaldehyde (PFA) for immunohistochemistry or disaggregated by enzymatic digestion for in vitro culture. Participants/materials, setting, methods After differential plating, fetal cells were cultured for 6 days. Disaggregated gonads were cultured with two different growing media (Medium 1 supplemented with LIF, EGF, FGF–2 and GDNF and Medium 2 supplemented with RA, BMP 4 and Activin A) on gelatin, laminin, vitronectin or matrigel coated plates. Cultured cells were immunostained, quantified for the expression of DDX4 and POU5F1 after 3 days (D3) and 6 days (D6) of culture. Main results and the role of chance We pursued to evaluate whether germ cells dissociated from a pool of male fetal gonads could propagate in vitro when cultured for D6 in different conditions. We observed that expansion of POU5F1-positive early PGCs and DDX4-positive late PGCs was only observed when cells were plated on gelatin or vitronectin and cultured with Medium 1, containing the growth factors LIF, EGF, FGF2 and GDNF. However, a reduced percentage of PGCs was observed in all four different coatings when grown with Medium 2, containing RA, BMP4 and Activin A. We analyzed the relative expression of the PGC markers POU5F1, DDX4 and MAGEA4 in histological sections of gonads from embryos at 18.5 weeks of gestation. Two populations of hPGCs were observed: ∼10–30% of the gonadal cells expressed solely DDX4 (late PGCs), whereas less than 10% of gonadal cells expressed POU5F1 (early PGCs). SOX9 and STARD1 expression was evaluated, confirming the presence of Sertoli cells and Leydig cells, respectively. Limitations, reasons for caution Due to the limited and difficulty to obtain human fetal tissue, a limited number of samples were used. Wider implications of the findings: We expanded human male fetal germ cells in vitro for D6 on gelatin and vitronectin coated plates with Medium 1, containing growth factors LIF, EGF, FGF2 and GDNF. Our findings provide a 2D culture system to expand hPGCs that could be useful to study propagation to pSPGs and eventually SSCs. Trial registration number Not applicable

Gap junction expression and cell proliferation in differentiating cultures of Cx43 KO mouse hepatocytes

2001 ◽  
Vol 281 (4) ◽  
pp. G1004-G1013 ◽  
Author(s):  
Takashi Kojima ◽  
Alfredo Fort ◽  
Mingyuan Tao ◽  
Masao Yamamoto ◽  
David C. Spray
Keyword(s):  
Lucifer Yellow ◽  
Primary Cultures ◽  
Mrna Levels ◽  
Wild Type ◽  
Dye Transfer ◽  
Gap Junctional Communication ◽  
Junctional Communication ◽  
Junctional Conductance ◽  
Mouse Hepatocytes

Primary cultures of adult mouse hepatocytes are shown here to reexpress differentiated hepatocyte features following treatment with 2% DMSO and 10−7 M glucagon. To examine the roles of gap junctional communication during hepatocyte growth and differentiation, we have compared treated and untreated hepatocytes from connexin (Cx)32-deficient [Cx32 knockout (KO)] and wild-type mice. In untreated cultures, DNA replication of Cx32 KO hepatocytes was markedly higher than of wild types. Although Cx26 mRNA levels remained high at all time points in wild-type and Cx32 KO hepatocytes, Cx32 mRNA and protein in wild-type hepatocytes underwent a marked decline, which recovered in 10-day treated cultures. Increased levels of Cx26 protein and junctional conductance were observed in Cx32 KO hepatocytes at 96 h in culture, a time when cell growth rate was high. Treatment with DMSO/glucagon highly reinduced Cx26 expression in Cx32 KO hepatocytes, and such treatment reinduced expression of both Cx32 and Cx26 expression in wild types. Dye transfer was not observed following Lucifer yellow injection into DMSO/glucagon-treated Cx32 KO hepatocytes, whereas the spread was extensive in wild types. Nevertheless, high junctional conductance values were observed in treated cells from both genotypes. These studies provide a method by which the differentiated phenotype can be obtained in cultured mouse hepatocytes and provide in vitro evidence that expression of gap junctions formed of Cx32 are involved in the regulation of growth of mouse hepatocytes.

scholarly journals Sestrin 2 Attenuates Rat Hepatic Stellate Cell (HSC) Activation and Liver Fibrosis via an mTOR/AMPK-Dependent Mechanism

2018 ◽  
Vol 51 (5) ◽  
pp. 2111-2122 ◽  
Author(s):  
Yi-Bing Hu ◽  
Xiao-Ting Ye ◽  
Qing-Qing Zhou ◽  
Rong-Quan Fu
Keyword(s):  
Liver Fibrosis ◽  
Protein Expression ◽  
Hepatic Fibrosis ◽  
Transforming Growth Factor ◽  
Histopathological Examination ◽  
Stellate Cell ◽  
Smooth Muscle Actin ◽  
Mrna Levels ◽  
Alpha Smooth Muscle Actin

Background/Aims: Sestrin 2 is associated with the pathophysiology of several diseases. The aim of this study was to investigate the effects and potential mechanisms of Sestrin 2 in rat hepatic stellate cells (HSCs) during liver fibrogenesis. Methods: In this study, Sestrin 2 protein expression was detected in rat HSC-T6 cells challenged with transforming growth factor-β (TGF-β) and in mice treated with carbon tetrachloride (CCl4), a well-known model of hepatic fibrosis. Next, HSC-T6 cells and fibrotic mice were transfected with lentivirus. The mRNA expression levels of markers of liver fibrosis [alpha-smooth muscle actin (α-SMA) and collagen 1A1 (Col1A1)] were analyzed by quantitative reverse transcription–polymerase chain reaction (RT-PCR). Cell death and proliferation were evaluated by the MTT assay, and biochemical markers of liver damage in serum [alanine transaminase (ALT) and aspartate transaminase (AST)] were also measured using a biochemical analyzer. Histopathological examination was used to evaluate the degree of liver fibrosis, and protein expression [phospho-adenosine monophosphate-activated protein kinase (p-AMPK), AMPK, phospho-mammalian target of rapamycin (p-mTOR), and mTOR] was determined by western blotting. Results: We found that Sestrin 2 was elevated in both the HSC-T6 cell and hepatic fibrosis models. In vitro, overexpression of Sestrin 2 attenuated the mRNA levels of α-SMA and Col1A1, suppressed α-SMA protein expression, and modulated HSC-T6 cell proliferation. In vivo, overexpression of Sestrin 2 reduced the ALT and AST levels as well as the α-SMA and Col1A1 protein expression in the CCl4 model of liver fibrosis. Moreover, the degree of liver fibrosis was ameliorated. Interestingly, overexpression of Sestrin 2 increased p-AMPK but decreased p-mTOR protein expression. Conclusion: Our findings indicate that Sestrin 2 may attenuate the activation of HSCs and ameliorate liver fibrosis, most likely via upregulation of AMPK phosphorylation and suppression of the mTOR signaling pathway.

scholarly journals 650 Target the activin receptor 1c on CD4+ T cells to achieve anti-tumor therapeutic effects

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A679-A679
Author(s):  
Ying Zheng ◽  
Andriana Lebid ◽  
Andrew Pardoll ◽  
Juan Fu ◽  
Chirag Patel ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Activin A ◽  
Pcr Analysis ◽  
Therapeutic Effects ◽  
Wild Type ◽  
Cd4 Cells ◽  
Activin Receptor ◽  
Tumor Bearing

BackgroundActivins, members of the transforming growth factor-ß (TGF-ß) superfamily, were isolated and identified in endocrine system, and have been widely studied in endocrine-related cancers,1 2 but not substantially in the context of immune system and endocrine-unrelated cancers.3–5 It has been reported that upon binding to the receptors, activins cause the intracellular recruitment and phosphorylation of smad proteins, which mediate the expression of Foxp3.6–9 Therefore, we hypothesized that the blockade of the interaction of activins and their receptors will inhibit the activins-mediated Foxp3 induction in CD4+ T cells, thus modify the immune suppressive tumor microenvironment and achieve the goal of cancer immunotherapy.MethodsELISA (enzyme-linked immunosorbent assay) has been performed to determine the plasma level of Activin A in tumor-bearing mice and cancer patients. In vitro iTreg (induced regulatory T cells) differentiation has been done to naïve CD4+ cells isolated from wild type mice in the presence or absence of Activin A, and the percentage of Foxp3+ cells was demonstrated by flow cytometric analysis. qRT-PCR analysis has been conducted to determine the mRNA level of activin receptor isotypes in the immune subpopulations sorted from Foxp3-YFP mice. In the end, in vivo subcutaneous transplanted tumor studies have been done to evaluate the anti-tumor therapeutic effects of activin-receptor 1c blockade.ResultsWe show here that tumor-bearing mice had elevated Activin A levels, which correlated directly with tumor burden. Likewise, cancer patients had elevated plasma Activin A compared to healthy controls. Importantly, our in vitro studies suggested that Activin A promoted differentiation of conventional CD4+ cells into Foxp3-expressing induced Tregs, especially when TGF-ß was limited. Database and qRT-PCR analysis of sorted major immune cell subsets in mice revealed that activin receptor 1C (Acvr1c) was uniquely expressed on Tregs and was highly upregulated during iTreg differentiation. Mice deficient in Acvr1c were more resistant to cancer progression compared to wild type mice. This phenotype correlated with reduced expression of the FoxP3 transcription factor in CD4+ cells. Similar phenomena were observed when we treated the mice with anti-Acvr1c antibody after tumor inoculation. This anti-tumor therapeutic effect was more significant when anti-Acvr1c antibody was administrated in combination with anti-PD-1 antibody.ConclusionsBlocking Activin A signaling through its receptor 1c is a promising and disease-specific strategy for preventing the accumulation of immunosuppressive iTregs in cancer. Hence it represents a potential candidate for cancer immunotherapy.AcknowledgementsThis research is supported by the Bloomberg-Kimmel Institute (Immunometabolism Program & Immune Modulation Program), the Melanoma Research Alliance, the NIH (RO1AI099300, RO1AI089830, and R01AI137046), and The DoD (PC130767).ReferencesRisbridger GP, Schmitt JF, Robertson DM. Activins and inhibins in endocrine and other tumors. Endocr Rev 2001;22(6):836–858.Cui X, et al. Perspectives of small molecule inhibitors of activin receptor-like kinase in anti-tumor treatment and stem cell differentiation (Review). Mol Med Rep 2019;19(6):5053–5062.Michael IP, et al. ALK7 signaling manifests a homeostatic tissue barrier that is abrogated during tumorigenesis and metastasis. Dev Cell 2019;49(3):409–424.Wu B, et al. The TGF-ß superfamily cytokine Activin-A is induced during autoimmune neuroinflammation and drives pathogenic Th17 cell differentiation. Immunity 2021;54(2):308–323.Antsiferova M, et al. Activin promotes skin carcinogenesis by attraction and reprogramming of macrophages. MBO Mol Med 2017;9(1):27–45.Tsuchida K, et al. Activin isoforms signal through type I receptor serine/threonine kinase ALK7. Mol Cell Endocrinol 2004;220(1–2):59–65.Khalil AM, et al. Differential binding activity of TGF-ß family proteins to select TGF-ß receptors. J Pharmacol Exp Ther 2016;358(3):423–430.Huber S, et al. Activin a promotes the TGF-beta-induced conversion of CD4+CD25- T cells into Foxp3+ induced regulatory T cells. J Immunol 2009;182(8):4633–4640.Iizuka-Koga M, et al. Induction and maintenance of regulatory T cells by transcription factors and epigenetic modifications. J Autoimmun 2017;83:113–121.Ethics ApprovalAll animal experiments were performed under protocols approved by the Johns Hopkins University Institutional Animal Care and Use Committee (IACUC).

scholarly journals The effect of calnexin deletion on the expression level of PDI in Saccharomyces cerevisiae under heat stress conditions

2008 ◽  
Vol 13 (1) ◽  
Author(s):  
Huili Zhang ◽  
Jianwei He ◽  
Yanyan Ji ◽  
Akio Kato ◽  
Youtao Song
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Growth Rate ◽  
Heat Stress ◽  
Protein Expression ◽  
Molecular Chaperone ◽  
Mrna Level ◽  
Stress Conditions ◽  
Mrna Levels ◽  
Wild Type ◽  
Wild Type Yeast

AbstractWe cultured calnexin-disrupted and wild-type Saccharomyces cerevisiae strains under conditions of heat stress. The growth rate of the calnexin-disrupted yeast was almost the same as that of the wild-type yeast under those conditions. However, the induced mRNA level of the molecular chaperone PDI in the ER was clearly higher in calnexin-disrupted S. cerevisiae relative to the wild type at 37°C, despite being almost the same in the two strains under normal conditions. The western blotting analysis for PDI protein expression in the ER yielded results that show a parallel in their mRNA levels in the two strains. We suggest that PDI may interact with calnexin under heat stress conditions, and that the induction of PDI in the ER can recover part of the function of calnexin in calnexin-disrupted yeast, and result in the same growth rate as in wild-type yeast.

Impaired mechanical stability, migration and contractile capacity in vimentin-deficient fibroblasts

1998 ◽  
Vol 111 (13) ◽  
pp. 1897-1907 ◽  
Author(s):  
B. Eckes ◽  
D. Dogic ◽  
E. Colucci-Guyon ◽  
N. Wang ◽  
A. Maniotis ◽  
...  
Keyword(s):  
Spatial Organization ◽  
Mechanical Stability ◽  
Wild Type Mouse ◽  
Wild Type ◽  
Cellular Functions ◽  
Primary Fibroblasts ◽  
In Vitro Systems ◽  
Filament Network ◽  
Collagen Lattices

Loss of a vimentin network due to gene disruption created viable mice that did not differ overtly from wild-type littermates. Here, primary fibroblasts derived from vimentin-deficient (-/-) and wild-type (+/+) mouse embryos were cultured, and biological functions were studied in in vitro systems resembling stress situations. Stiffness of -/- fibroblasts was reduced by 40% in comparison to wild-type cells. Vimentin-deficient cells also displayed reduced mechanical stability, motility and directional migration towards different chemo-attractive stimuli. Reorganization of collagen fibrils and contraction of collagen lattices were severely impaired. The spatial organization of focal contact proteins, as well as actin microfilament organization was disturbed. Thus, absence of a vimentin filament network does not impair basic cellular functions needed for growth in culture, but cells are mechanically less stable, and we propose that therefore they are impaired in all functions depending upon mechanical stability.

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