scholarly journals Regulation of the C/EBP-related gene gadd153 by glucose deprivation.

1993 ◽  
Vol 13 (8) ◽  
pp. 4736-4744 ◽  
Author(s):  
S G Carlson ◽  
T W Fawcett ◽  
J D Bartlett ◽  
M Bernier ◽  
N J Holbrook
Keyword(s):  
Glucose Utilization ◽  
Glucose Deprivation ◽  
Negative Regulator ◽  
Mrna Levels ◽  
Hormonal Stimulation ◽  
Differentiation Protocol ◽  
Enhancer Binding Protein ◽  
Functional Dna ◽  
Gadd153 Expression

gadd153 encodes a CCAAT/enhancer-binding protein (C/EBP)-related protein that lacks a functional DNA-binding domain. Since the gadd153 protein is capable of heterodimerizing with other C/EBPs, gadd153 may function as a negative regulator of these transcription factors. Here we examined the role of glucose in regulating gadd153 expression. We found that glucose deprivation markedly induces gadd153 mRNA levels in both HeLa and 3T3-L1 cells and that addition of D-(+)-glucose resulted in a rapid decrease of gadd153 mRNA. Similar induction and reversal of gadd153 expression were observed at the protein level. Because C/EBP alpha appears to play an important role in regulating genes involved in adipogenesis and energy metabolism, we examined gadd153 expression during the differentiation of 3T3-L1 preadipocytes and as a function of glucose utilization in differentiated adipocytes. Using a standard differentiation protocol that consisted of hormonal stimulation for 2 days followed by medium changes every 2 days thereafter, we observed that both C/EBP alpha and gadd153 mRNAs were elevated. However, C/EBP alpha induction occurred on day 3, while gadd153 expression was not seen until day 4, when the cells were fully differentiated. Frequent addition of fresh medium to the cells during the differentiation process, as well as supplementation of medium with glucose, reduced gadd153 expression without preventing C/EBP alpha expression or interfering with cellular differentiation. Thus, gadd153 expression is not essential for the process of adipocyte differentiation but is significantly influenced by the availability of glucose to the cell.

Regulation of the C/EBP-related gene gadd153 by glucose deprivation

1993 ◽  
Vol 13 (8) ◽  
pp. 4736-4744
Author(s):  
S G Carlson ◽  
T W Fawcett ◽  
J D Bartlett ◽  
M Bernier ◽  
N J Holbrook
Keyword(s):  
Glucose Utilization ◽  
Glucose Deprivation ◽  
Negative Regulator ◽  
Mrna Levels ◽  
Hormonal Stimulation ◽  
Differentiation Protocol ◽  
Enhancer Binding Protein ◽  
Functional Dna ◽  
Gadd153 Expression

gadd153 encodes a CCAAT/enhancer-binding protein (C/EBP)-related protein that lacks a functional DNA-binding domain. Since the gadd153 protein is capable of heterodimerizing with other C/EBPs, gadd153 may function as a negative regulator of these transcription factors. Here we examined the role of glucose in regulating gadd153 expression. We found that glucose deprivation markedly induces gadd153 mRNA levels in both HeLa and 3T3-L1 cells and that addition of D-(+)-glucose resulted in a rapid decrease of gadd153 mRNA. Similar induction and reversal of gadd153 expression were observed at the protein level. Because C/EBP alpha appears to play an important role in regulating genes involved in adipogenesis and energy metabolism, we examined gadd153 expression during the differentiation of 3T3-L1 preadipocytes and as a function of glucose utilization in differentiated adipocytes. Using a standard differentiation protocol that consisted of hormonal stimulation for 2 days followed by medium changes every 2 days thereafter, we observed that both C/EBP alpha and gadd153 mRNAs were elevated. However, C/EBP alpha induction occurred on day 3, while gadd153 expression was not seen until day 4, when the cells were fully differentiated. Frequent addition of fresh medium to the cells during the differentiation process, as well as supplementation of medium with glucose, reduced gadd153 expression without preventing C/EBP alpha expression or interfering with cellular differentiation. Thus, gadd153 expression is not essential for the process of adipocyte differentiation but is significantly influenced by the availability of glucose to the cell.

Role of glucocorticoids in activation of hepatic PEPCK gene transcription during exercise

1994 ◽  
Vol 266 (4) ◽  
pp. E560-E566 ◽  
Author(s):  
J. E. Friedman
Keyword(s):  
Transgenic Mice ◽  
Gene Transcription ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Mrna Levels ◽  
Camp Response Element ◽  
Carbohydrate Diet ◽  
High Carbohydrate ◽  
Enhancer Binding Protein ◽  
Response To Exercise

The objective of these studies was to determine the molecular basis for the activation of phosphoenolpyruvate carboxykinase (PEPCK) gene transcription during prolonged submaximal exercise. Mice were fed a high-carbohydrate diet for 1 wk and exercised continuously by swimming for up to 120 min. The level of hepatic PEPCK mRNA increased progressively during exercise, reaching 510% above control, whereas transcription of the PEPCK gene increased 1,000%, before decreasing to control levels within 60 min of recovery. In transgenic mice carrying a chimeric gene consisting of the PEPCK promoter linked to a reporter gene for bovine growth hormone (bGH), PEPCK(-460)-bGH, the level of hepatic bGH mRNA increased by 490% in response to exercise, similar to the increase in the expression of the native PEPCK gene. However, in transgenic mice with a deletion of the glucocorticoid regulatory unit, PEPCK(-355)-bGH, bGH mRNA did not increase above control values. In transgenic mice with a block mutation in adenosine 3',5'-cyclic monophosphate (cAMP) regulatory regions -90/-82 and -250/-234, PEPCK cAMP response element 1 (CRE-1)/P3(1)-bGH, exercise increased bGH mRNA 260% above controls. Adrenalectomy (Adx) had no effect on PEPCK mRNA levels in nonexercised mice, whereas in adrenalectomized (Adx)-exercised mice, PEPCK mRNA increased only 80% above basal, and, in Adx mice injected with dexamethasone, PEPCK mRNA increased with exercise 570% above controls. Exercise was also associated with a large increase in transcription of the gene for the transcription factor CCAAT/enhancer-binding protein beta (C/EBP-beta) and a smaller rise in transcription of c-jun gene, both of which returned to control levels during recovery.(ABSTRACT TRUNCATED AT 250 WORDS)

XIAP mRNA levels but not XAF1 or XIAP/XAF1 mRNA levels predict pathological response in bladder cancer patients treated with neoadjuvant chemotherapy

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 20030-20030
Author(s):  
M. B. Pinho ◽  
J. Sellos ◽  
F. Costas ◽  
D. Herchenhorn ◽  
F. A. Peixoto ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Mrna Expression ◽  
Cancer Patients ◽  
Pathological Response ◽  
Negative Regulator ◽  
Inhibitor Of Apoptosis ◽  
Mrna Levels ◽  
Bivariate Correlation ◽  
Xiap Expression

20030 Background: The relation between apoptosis-related molecules and chemosensitivity has been extensively studied. In recent years, attention has shifted to a new family of inhibitor of apoptosis proteins (IAPs). XIAP (X- linked inhibitor of apoptosis) is the most versatile and potent member of the IAP family. To date, the overexpression of XIAP has been detected in various cancers. XAF1 (X-linked inhibitor of apoptosis associated factor 1) is a new protein identified for its ability to interact with XIAP. Neither XIAP nor XAF1 or XIAP/XAF1 mRNA expression have been studied in bladder cancer patients. Methods: The expression of XIAP and XAF1 mRNA was analyzed by a real time quantitative fluorogenic PCR method in a group of 17 patients with locally advanced bladder cancer treated with a combination of neoadjuvant Gemcitabine and Cisplatin. The prognostic significance of XIAP and XAF1 mRNA expression and the correlation with several clinicopathological variables was evaluated. Results: XIAP and XAF1 mRNA expression was detected in all 17 (100%) case samples. The levels of XIAP mRNA expression showed a moderate variation among samples. In contrast, XAF1 and XIAP/XAF1 mRNA levels showed significant variation among samples. Bivariate correlation analyses revealed a significant positive Spearman direct correlation coefficient between the XIAP expression and the pathological response. No significant correlation was found for XAF1 expression as well as for the XIAP/XAF1 ratio and clinical and pathological response. Conclusions: This is first study to address the role of XIAP, its negative regulator XAF1, and the XIAP/XAF1 ratio in bladder cancer patients. The positive correlation between the XIAP mRNA expression and the pathological response is in line with a previous study from our group in which a correlation was found between XIAP expression and survival. All these observations point to a complex role of XIAP in tumor biology. XAF1 mRNA expression in bladder carcinomas did not achieve significance as an independent predictive and prognostic factor in a bivariate analysis. Further studies are necessary in order to better assess a possible clinical value for XIAP and XAF1 as predictive and prognostic markers in cancer patients. No significant financial relationships to disclose.

scholarly journals A Novel Role of Numb as A Regulator of Pro-inflammatory Cytokine Production in Macrophages in Response to Toll-like Receptor 4

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Patipark Kueanjinda ◽  
Sittiruk Roytrakul ◽  
Tanapat Palaga
Keyword(s):  
Notch Signaling ◽  
P38 Mapk ◽  
Inflammatory Responses ◽  
Notch Signaling Pathway ◽  
Negative Regulator ◽  
Mrna Levels ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Murine Bone Marrow

Abstract Activation of macrophages triggers the release of pro-inflammatory cytokines leading to inflammation. Numb is a negative regulator of Notch signaling, but the role of Numb in macrophages is not fully understood. In this study, the role of Numb as a regulator of inflammatory responses in macrophages was investigated. Murine bone marrow-derived macrophages, in which expression of Numb was silenced, secreted significantly less TNFα, IL-6 and IL-12 and more IL-10 upon activation by lipopolysaccharide (LPS), a ligand for Toll-like receptor 4 (TLR4), despite increased Notch signaling. The Tnfα mRNA levels both in Numb-deficient and wild-type macrophages were not significantly different, unlike those of Il6 and Il12-p40. In Numb-deficient macrophages, the Tnfα mRNAs were degraded at faster rate, compared to those in control macrophages. Activation of p38 MAPK and NF-κΒ p65 were compromised in activated Numb deficient macrophages. Numb was found to interact with the E3 ubiquitin ligase, Itch, which reportedly regulates p38 MAPK. In addition, blocking the Notch signaling pathway in activated, Numb-deficient macrophages did not further reduce TNFα levels, suggesting a Notch-independent role for Numb. A proteomics approach revealed a novel funciton for Numb in regulating complex signaling cascades downstream of TLRs, partially involving Akt/NF-κB p65/p38 MAPK in macrophages.

scholarly journals Silencing the Honey Bee (Apis mellifera) Naked Cuticle Gene (nkd) Improves Host Immune Function and Reduces Nosema ceranae Infections

2016 ◽  
Vol 82 (22) ◽  
pp. 6779-6787 ◽  
Author(s):  
Wenfeng Li ◽  
Jay D. Evans ◽  
Qiang Huang ◽  
Cristina Rodríguez-García ◽  
Jie Liu ◽  
...  
Keyword(s):  
Apis Mellifera ◽  
Immune Function ◽  
Honey Bee ◽  
Honey Bees ◽  
Nosema Ceranae ◽  
Negative Regulator ◽  
Mrna Levels ◽  
Content Type ◽  
Bee Disease

ABSTRACTNosema ceranaeis a new and emerging microsporidian parasite of European honey bees,Apis mellifera, that has been implicated in colony losses worldwide. RNA interference (RNAi), a posttranscriptional gene silencing mechanism, has emerged as a potent and specific strategy for controlling infections of parasites and pathogens in honey bees. While previous studies have focused on the silencing of parasite/pathogen virulence factors, we explore here the possibility of silencing a host factor as a mechanism for reducing parasite load. Specifically, we used an RNAi strategy to reduce the expression of a honey bee gene,naked cuticle(nkd), which is a negative regulator of host immune function. Our studies found thatnkdmRNA levels in adult bees were upregulated byN. ceranaeinfection (and thus, the parasite may use this mechanism to suppress host immune function) and that ingestion of double-stranded RNA (dsRNA) specific tonkdefficiently silenced its expression. Furthermore, we found that RNAi-mediated knockdown ofnkdtranscripts inNosema-infected bees resulted in upregulation of the expression of several immune genes (Abaecin,Apidaecin,Defensin-1, andPGRP-S2), reduction ofNosemaspore loads, and extension of honey bee life span. The results of our studies clearly indicate that silencing the hostnkdgene can activate honey bee immune responses, suppress the reproduction ofN. ceranae, and improve the overall health of honey bees. This study represents a novel host-derived therapeutic for honey bee disease treatment that merits further exploration.IMPORTANCEGiven the critical role of honey bees in the pollination of agricultural crops, it is urgent to develop strategies to prevent the colony decline induced by the infection of parasites/pathogens. Targeting parasites and pathogens directly by RNAi has been proven to be useful for controlling infections in honey bees, but little is known about the disease impacts of RNAi silencing of host factors. Here, we demonstrate that knocking down the honey bee immune repressor-encodingnkdgene can suppress the reproduction ofN. ceranaeand improve the overall health of honey bees, which highlights the potential role of host-derived and RNAi-based therapeutics in controlling the infections in honey bees. The information obtained from this study will have positive implications for honey bee disease management practices.

scholarly journals Downregulated KLF2 in PV and ET May Induce Prothrombotic Gene Expression

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 13-14
Author(s):  
Jihyun Song ◽  
Jahnavi Gollamudi ◽  
Soo Jin Kim ◽  
Radhika Gangaraju ◽  
Tsewang Tashi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Tissue Factor ◽  
Research Funding ◽  
Interleukin 1 ◽  
Negative Regulator ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Inherited Disorders ◽  
History Of

Polycythemia vera (PV) and essential thrombocythemia (ET) patients have a higher risk of arterial and venous thrombosis than healthy individuals; thromboses are their principal cause of morbidity and mortality. We reported increased transcription of prothrombotic and inflammatory genes in granulocytes and platelets of PV and ET. There were differences in the expression of prothrombotic genes between platelets and granulocytes, suggesting that these cells have cell-specific contributions to thrombosis in PV and ET. Some of these prothrombotic genes are regulated by hypoxia inducible factors (HIFs) (PMID: 32203583). However, the molecular mechanism of thrombosis in PV and ET remains unknown. KLF2 (Kruppel like factor 2) is a transcription factor regulating primitive erythropoiesis and inflammation. Knockdown of KLF2 in cultured endothelial cells increases prothrombotic gene expression and reduces blood clotting time and flow rates (PMID: 15718498). Targeted deletion of KLF2 in neutrophils increases thrombosis by inducing the expression and activity of tissue factor (Blood, 2018, 132:75). To study the role of KLF2 in PV and ET thrombosis, we measured KLF2 mRNA in granulocytes from 53 PV and ET patients (25 with a history of thrombosis) and in platelets from 40 patients (21 with a history of thrombosis). We also measured KLF2 mRNA in granulocytes from 38 controls and platelets from 18 controls. Althrough the role of KLF2 in thrombosis has been studied in neutrophils, we also tested KLF2 mRNA in platelets since we previously observed a different pattern of expression of prothrombotic genes between granulocytes and platelets in PV and ET. We found lower KLF2 mRNA in both granulocytes and platelets of PV and ET patients compared to the controls (Fig. 1A and B). Compared to patients without thrombosis, those with thrombosis had lower KLF2 mRNA in platelets but not granulocytes. KLF2 mRNA in these cells correlated inversely with JAK2V617F allele burden in granulocytes (Fig. 1C and D). We then measured mRNA of prothrombotic genes: F3 (tissue factor), SELP (P-selectin), IRAK1 (interleukin 1 receptor associated kinase 1), IL1RAP (interleukin 1 receptor accessory protein), VEGFA (vascular endothelial growth factor-A), THSB1 (thrombospondin 1), SERPINE1 (encoding plasminogen activator inhibitor 1 [PAI-1]). The mRNA levels of these prothrombotic genes correlated inversely with KLF2 mRNA in platelets while SELP and THSB1 transcripts correlated inversely with KLF2 mRNA in granulocytes. KLF2 and HIFs are reported to interact (PMID: 19491109, PMID: 21565532). In order to elucidate the regulatory machanism of KLF2 in thrombosis, we measured KLF2 mRNA in patients with two inherited disorders of hypoxia sensing characterized by thrombosis: 1) Chuvash erythrocytosis (CE) due to homozygous mutation of VHLR200W (13 patients) and 2) erythrocytosis due to gain-of-function mutation of HIF-2a (two patients with HIF2AM535V and two patients HIF2AE548K). KLF2 mRNA levels did not differ in granulocytes and platelets between these patients and controls. However, two CE patients and two patients with HIF2AM535V with a history of thrombosis had lower KLF2 mRNA levels compared to patients without thrombosis (ASH this meeting, 2020 Song J). In conclusion, we report here that KLF2 transcripts are down regulated in both granulocytes and platelets from PV and ET patients and they correlate inversely with the transcripts of prothrombotic genes and JAK2V617F allelic burden, suggesting that KLF2 might be a negative regulator of thrombotic gene expression in PV and ET. Here we did not detect any changes of KLF2 transcripts in congential disorders with elevated HIFs. However, two CE patients and 2 patients with HIF2AM535V with thrombosis had less KLF2 expression compared to those without thrombosis. These results suggest that, by inference from findings in congenital disorders with elevated HIFs, KLF2 in PV and ET granulocytes and platelets may be regulated in a HIF-independent manner but that thrombosis may be regulated in a HIF-dependent manner. Thus, KLF2 may be a novel therapeutic target to prevent thrombosis in PV and ET, but confirmation by further studies is needed. The upstream regulation of KLF2 in PV and ET granulocytes and platelets needs to be elucidated. *PT &JTP contributed equally Disclosures Gangaraju: Sanofi Genzyme, Consultant for Cold Agglutinin Disease: Consultancy. Gordeuk:CSL Behring: Consultancy, Research Funding; Global Blood Therapeutics: Consultancy, Research Funding; Imara: Research Funding; Ironwood: Research Funding; Novartis: Consultancy.

Evidence for PTEN Deficiency in Juvenile Myelomonocytic Leukemia.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3428-3428
Author(s):  
Y. Lucy Liu ◽  
Likang Xu ◽  
Robert P. Castleberry ◽  
Peter Dean Emanuel
Keyword(s):  
Bone Marrow ◽  
Negative Regulator ◽  
Juvenile Myelomonocytic Leukemia ◽  
Ras Signaling ◽  
Mrna Levels ◽  
Pten Protein ◽  
Gm Csf ◽  
The Status ◽  
Myelomonocytic Leukemia

Abstract Juvenile myelomonocytic leukemia (JMML) is a myelodysplastic/myeloproliferative disorder (MDS/MPD) of young children. It is characterized by monocytosis, leukocytosis, elevated fetal hemoglobin, hypersensitivity to granulocyte-macrophage colony-stimulating factor (GM-CSF), low percentage of myeloblasts in bone marrow, and absence of the Philadelphia chromosome. The pathogenesis of JMML has been linked to dysregulated signal transduction through the NF1/RAS signaling pathway and PTPN11. This dysregulation results in JMML cells demonstrating selective hypersensitivity to GM-CSF in vitro dose-response assays. PTEN, a major negative regulator of the PI3-kinase pathway by virtue of its PIP3 phosphatase activity, was initially isolated as a tumor suppressor in a variety of malignancies. In order to evaluate the role of PTEN in the pathogenesis of JMML, we examined the status of PTEN in JMML patient samples. Peripheral blood or bone marrow was collected from 40 patients. Mononuclear cells (MNCs) were isolated and lysed in lysis buffer at a concentration of 107/ml. Total RNA was extracted from MNCs of patients and 17 normal individuals. Protein and mRNA levels of PTEN were evaluated by Western-blot and relative-quantitative real-time RT-PCR, respectively. We found that PTEN protein was decreased in 18 of 30 (60%) JMML patients, and the patients had significantly lower RNA expression of PTEN than normal controls (p=0.015). With the available samples we also evaluated AKT activity and MAP kinase (MAPK) levels. We found that MAPK levels were correlated well with the status of the PTEN in 12 of 27(44%), and AKT activity in 13 of 25 patients (52%). Our data indicates that PTEN is significantly deficient in JMML patients, and the low PTEN protein level is related to its low transcription of RNA in JMML patients. The role of PTEN in regulation of MAPK and AKT activities in JMML is under further evaluation by studying the upstream status of the RAS pathway prior to PTEN. This is the first investigation of PTEN deficiency in JMML patients, and additional investigations may help to further understand the pathogenetic mechanisms in JMML, as well as to guide the development of targeted therapeutics for JMML.

scholarly journals Hippo Pathway mediator TAZ acts as a negative regulator of the sodium iodide symporter

2016 ◽  
Vol 62 (5) ◽  
pp. 51-52
Author(s):  
Celia Fernández-Méndez ◽  
Pilar Santisteban
Keyword(s):  
Thyroid Carcinoma ◽  
Sodium Iodide ◽  
Hippo Pathway ◽  
Negative Regulator ◽  
Nuclear Accumulation ◽  
Mrna Levels ◽  
Partial Recovery ◽  
Sodium Iodide Symporter ◽  
Thyroid Cells

Background. TAZ/WWTR1 (transcriptional coactivator with a PDZ-binding domain) is a transcriptional cofactor involved in the Hippo Signalling pathway, which is described to have a key role in the control of cell proliferation, apoptosis, the inhibition of cell-cell contact, stem cell self-renewal and tissue regeneration. TAZ has been reported to regulate these processes through the transactivation of transcription factors in the nucleus, where it has also been shown to interact with Smad2/3-Smad4 complexes favouring nuclear accumulation under TGFβ stimulation. TAZ co-activates Pax8, a master gene of thyroid differentiation, within the thyroglobulin promoter. Furthermore, Pax8 is the main positive regulator of sodium iodide symporter (NIS) expression and it has been reported to interact with Smad3 causing NIS transcriptional repression mediated by TGFβ.Aim. Therefore, the aim of this work was to study the involvement of TAZ in the expression of NIS, since it is an important protein not only for the correct function of the thyroid gland, but also for radioiodide treatment in thyroid cancer.Methods and Results. Strikingly, we observed that TAZ negatively regulates the transcriptional activity of Pax8 within the NIS promoter. Furthermore, we provided evidence that TAZ could play an important role in the downregulation of NIS expression by TGFβ; we detected that TAZ protein is mainly located in the nucleus under treatment with this cytokine and its silencing induces a partial recovery of NIS protein and mRNA levels. Our results also demonstrated an increased expression of TAZ in thyroid carcinoma cell lines, in which NIS levels are typically decreased. Specifically, TAZ nuclear translocation is increased in those thyroid carcinoma cells with mutated BRAFV600E or when this oncogene is conditionally activated. Since we have described that this mutation increases the secretion of TGFβ, this could be connected with the decreased levels of NIS in these cells.Conclusion. This study has shed light on the important role of the Hippo pathway in the regulation of NIS expression in thyroid cells, repressing Pax8 activity and impaired thyroid differentiation. Given that this protein has been identified to be overexpressed in thyroid carcinoma, future research of the role of TAZ in thyroid tumorogenesis will enable development of new strategies to treat thyroid cancer.

Opposite regulation of connexin33 and connexin43 by LPS and IL-1α in spermatogenesis

2006 ◽  
Vol 290 (3) ◽  
pp. C733-C740 ◽  
Author(s):  
Celine Fiorini ◽  
Xavier Decrouy ◽  
Norah Defamie ◽  
Dominique Segretain ◽  
Georges Pointis
Keyword(s):  
Gap Junction ◽  
Sertoli Cell ◽  
Negative Regulator ◽  
Seminiferous Tubules ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Cx43 Expression ◽  
Gap Junction Communication ◽  
Cx43 Mrna

The gap junction proteins, connexins (Cxs), are present in the testis, and among them, Cx43 play an essential role in spermatogenesis. In the present study, we investigated the testicular expression and regulation of another Cx, Cx33, previously described as a negative regulator of gap junction communication. Cx33 mRNA was present in testis and undetectable in heart, liver, ovary, and uterus. In the mature testis, Cx33 was specifically immunolocalized in the basal compartment of the seminiferous tubules, whereas Cx43 was present in both seminiferous tubule and interstitial compartments. During stages IX and X of spermatogenesis, characterized by Sertoli cell phagocytosis of residual bodies, Cx43 was poorly expressed within seminiferous tubules, while Cx33 signal was strong. To evaluate the role of phagocytosis in the control of Cx33 and Cx43 expression, the effect of LPS was analyzed in the Sertoli cell line 42GPA9. We show herein that phagocytosis activation by LPS concomitantly stimulated Cx33 and inhibited Cx43 mRNA levels. These effects appear to have been mediated through IL-1α, because the exposure of Sertoli cells to the IL-1 receptor antagonist partly reversed these effects. IL-1α enhanced and reduced, respectively, the levels of Cx33 and Cx43 mRNA in a time- and dose-dependent manner. These data reveal that Cx33 and Cx43 genes are controlled differently within the testis and suggest that these two Cxs may exert opposite and complementary effects on spermatogenesis.

scholarly journals The role of Trx/TBP-2 in oxidative stress induced autophagy in human lens epithelial cells

2019 ◽  
Author(s):  
Jianghua Hu ◽  
Lifang Shen ◽  
Chengshou Zhang ◽  
Ke Yao ◽  
Yibo Yu
Keyword(s):  
Oxidative Stress ◽  
Epithelial Cells ◽  
Cellular Response ◽  
Negative Regulator ◽  
Cell Counting ◽  
Human Lens ◽  
Lens Epithelial Cells ◽  
Mrna Levels ◽  
Human Lens Epithelial Cells

Abstract Background: Oxidative stress plays an important role in age-related cataract development. The cellular antioxidant protein thioredoxin (Trx) and its negative regulator, thioredoxin binding protein-2 (TBP-2), maintain the intracellular redox balance upon oxidative stress. The aim of this study is to investigate role of Trx and TBP-2 in human lens epithelial cells (LECs) under oxidative stress. Methods: LECs were treated with 50 μM of H2O2 serum-free medium for different duration, and the mRNA and protein levels of Trx-1, Trx-2 and TBP-2 were measured by reverse transcription-polymerase chain reaction and Western blot. Trx-1 activity was evaluated by Thioredoxin Activity Fluorescent Assay. The subcellular localization of Trx-1, Trx-2 and TBP-2 was evaluated by cellular immunofluorescence. The cell viability was detected by Cell Counting Kit-8 (CCK-8) and the LC3-II protein level was detected to evaluate the autophagy level. The interaction between Trx-2 and TBP-2 was examined by Co-Immunoprecipitation (Co-IP). Results: The results showed that the mRNA levels of the Trx-1, Trx-2 and TBP-2 were kinetically changed after treatment with 50 μM of H2O2 for different duration. Exposure to H2O2 increased the expression of Trx-2 and TBP-2 but not Trx-1, while the exposure inhibited Trx-1 activity. TBP-2 was co-localized with Trx-1 and Trx-2, exposure to H2O2 enriched co-localization of TBP-2 to Trx-1 but not Trx-2, and increased the interaction between TBP-2 and Trx-1. Under normal circumstances, Trx-1 over-expression enhanced autophagic response and mainly regulates autophagy in the initiation. Conclusions: This study demonstrates differential roles of Trx-1 and Trx-2 in cellular response to oxidative stress, and oxidative stress increased Trx-1 interacting to TBP-2 and Trx-1 regulating autophagic response.

Sign in / Sign up

Export Citation Format

Share Document