Oxidized-LDL inhibits testosterone biosynthesis by affecting mitochondrial function and the p38 MAPK/COX-2 signaling pathway in Leydig cells

This study was carried out to investigate whether ADM can modulate LPS-induced inflammation and apoptosis in rat Leydig cells. Leydig cells were treated with ADM before LPS-induced cytotoxicity. We determined the concentrations of ROS, MDA, GSH, LDH, and testosterone and the MMP. The mRNA levels of IL-1, IL-6, iNOS, and COX-2 were obtained, and the concentrations of IL-1, IL-6, NO, and PGE2 were determined. Apoptosis was assessed by TUNEL and detection of DNA fragmentation. The levels of mRNA and protein were determined for Bcl-2, Bax, caspase-3, and PARP. The protein contents for total and p-Akt were measured. ADM pretreatment significantly elevated the MMP and testosterone concentration and reduced the levels of ROS, MDA, GSH, and LDH. ADM pretreatment significantly decreased the mRNA levels of IL-1, IL-6, iNOS, and COX-2 and the concentrations of IL-1, IL-6, NO, and PGE2. LPS-induced TUNEL-positive Leydig cells were significantly decreased by ADM pretreatment, a result further confirmed by decreased DNA fragmentation. ADM pretreatment decreased apoptosis by significantly promoting Bcl-2 and inhibiting Bax, caspase-3, and PARP expressions. The LPS activity that reduced p-Akt level was significantly inhibited by ADM pretreatment. ADM protected rat Leydig cells from LPS-induced inflammation and apoptosis, which might be associated with PI3K/Akt mitochondrial signaling pathway.

Download Full-text

Dehydroepiandrosterone-Regulated Testosterone Biosynthesis via Activation of the ERK1/2 Signaling Pathway in Primary Rat Leydig Cells

Cellular Physiology and Biochemistry ◽

10.1159/000430150 ◽

2015 ◽

Vol 36 (5) ◽

pp. 1778-1792 ◽

Cited By ~ 6

Author(s):

Lin Liu ◽

Jian Kang ◽

Xiao Ding ◽

Di Chen ◽

Yingqiao Zhou ◽

...

Keyword(s):

Protein Expression ◽

Signaling Pathway ◽

Leydig Cells ◽

Expression Level ◽

Target Cells ◽

Protein Expression Level ◽

Expression Levels ◽

Creb Protein ◽

Protein Levels ◽

Testosterone Biosynthesis

Background: Dehydroepiandrosterone decreases with age and this reduction has been shown to be associated with physical health in human. Some studies have suggested that the effects of DHEA are exerted after it is biotransformed into more biologically-active hormones in peripheral target cells. This study investigated the effects of DHEA on the testosterone biosynthesis and possible signaling pathway mechanism underlying these DHEA effects were also explored in primary rat Leydig cells. Methods: Primary Leydig cells were treated with DHEA and then detected testosterone content by RIA and steroidogenic enzymes, ERK1/2 signal pathway factors protein expression level by Western blot. Results: Incubation of primary Leydig cells with DHEA significantly increased testosterone content and 3β-HSD and 17β-HSD protein expression levels, while aromatase protein expression levels were decreased. Compared with the control group, p-ERK1/2 and p-CREB protein levels were significantly increased in DHEA-treated groups. Testosterone content was significantly decreased in the DHEA-treated group pre-incubated with U0126 (p-ERK1/2 inhibitor). Additionally, the rise in p-ERK1/2, 3β-HSD and 17β-HSD protein levels induced by DHEA was reversed when cells were pre-incubated with U0126. Interestingly, no significant difference was found in aromatase protein expression level in cells pretreated with U0126. Conclusion: These findings demonstrate that (a) exogenous DHEA might preferentially convert to testosterone rather than estradiol due to the up-regulation of 3β-HSD and 17β-HSD protein levels and the down-regulation of aromatase protein level in primary Leydig cells, and (b) the action of DHEA is at least partly associated with the elevation of p-ERK1/2 and p-CREB protein levels.

Download Full-text

Attenuation of High Glucose-Induced Damage in RPE Cells through p38 MAPK Signaling Pathway Inhibition

Frontiers in Pharmacology ◽

10.3389/fphar.2021.684680 ◽

2021 ◽

Vol 12 ◽

Author(s):

Grazia Maugeri ◽

Claudio Bucolo ◽

Filippo Drago ◽

Settimio Rossi ◽

Michelino Di Rosa ◽

...

Keyword(s):

Signaling Pathway ◽

P38 Mapk ◽

High Glucose ◽

Retinal Pigment ◽

Mapk Signaling ◽

Mapk Signaling Pathway ◽

Rpe Cells ◽

Cox 2

This study aimed to investigate the high glucose damage on human retinal pigment epithelial (RPE) cells, the role of p38 MAPK signaling pathway and how dimethyl fumarate can regulate that. We carried out in vitro studies on ARPE-19 cells exposed to physiological and high glucose (HG) conditions, to evaluate the effects of DMF on cell viability, apoptosis, and expression of inflammatory and angiogenic biomarkers such as COX-2, iNOS, IL-1β, and VEGF. Our data have demonstrated that DMF treatment attenuated HG-induced apoptosis, as confirmed by reduction of BAX/Bcl-2 ratio. Furthermore, in RPE cells exposed to HG we observed a significant increase of iNOS, COX-2, and IL-1β expression, that was reverted by DMF treatment. Moreover, DMF reduced the VEGF levels elicited by HG, inhibiting p38 MAPK signaling pathway. The present study demonstrated that DMF provides a remarkable protection against high glucose-induced damage in RPE cells through p38 MAPK inhibition and the subsequent down-regulation of VEGF levels, suggesting that DMF is a small molecule that represents a good candidate for diabetic retinopathy treatment and warrants further in vivo and clinical evaluation.

Download Full-text

Adrenomedullin Rescues Testicular Steroidogenesis of Leydig Cells by Suppressing TGF-β1 via PI3K/Akt-Dependent Activation of GSK-3β/β-Catenin Signaling Pathway

SSRN Electronic Journal ◽

10.2139/ssrn.3667643 ◽

2020 ◽

Author(s):

Wei Hu ◽

Xia-lian Zhu ◽

Chang-geng Xu ◽

Ming-yong Li ◽

Wei Wang ◽

...

Keyword(s):

Signaling Pathway ◽

Leydig Cells ◽

Testicular Steroidogenesis ◽

Gsk 3Β ◽

Tgf Β1

Download Full-text

The PD ‐1 / PD‐L1 binding inhibitor BMS ‐202 suppresses the synthesis and secretion of gonadotropins and enhances apoptosis via p38 MAPK signaling pathway

Drug Development Research ◽

10.1002/ddr.21857 ◽

2021 ◽

Author(s):

Ying Jiang ◽

Jinglin Zhang ◽

Jingtao Qiu ◽

Sheng Cui

Keyword(s):

Signaling Pathway ◽

P38 Mapk ◽

Mapk Signaling ◽

Mapk Signaling Pathway

Download Full-text

Involvement of the p38 MAPK signaling pathway in S-phase cell-cycle arrest induced by Furazolidone in human hepatoma G2 cells

Journal of Applied Toxicology ◽

10.1002/jat.2829 ◽

2012 ◽

Vol 33 (12) ◽

pp. 1500-1505 ◽

Cited By ~ 6

Author(s):

Yu Sun ◽

Shusheng Tang ◽

Xi Jin ◽

Chaoming Zhang ◽

Wenxia Zhao ◽

...

Keyword(s):

Cell Cycle ◽

Cell Cycle Arrest ◽

Signaling Pathway ◽

P38 Mapk ◽

Mapk Signaling ◽

S Phase ◽

Mapk Signaling Pathway ◽

Phase Cell ◽

Human Hepatoma ◽

Cycle Arrest

Download Full-text

Expression of VEGF-A Signaling Pathway in Cartilage of ACLT-induced Osteoarthritis Mouse Model

Journal of Orthopaedic Surgery and Research ◽

10.1186/s13018-021-02528-w ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

Jia-jia Qian ◽

Qi Xu ◽

Wei-min Xu ◽

Ren Cai ◽

Gui-cheng Huang

Keyword(s):

Signaling Pathway ◽

Cruciate Ligament ◽

Time Dependent ◽

Pathological Changes ◽

The Matrix ◽

Vegfr2 Signaling ◽

Cox 2 ◽

Anterior Cruciate ◽

A Disintegrin And Metalloproteinase ◽

Safranin O

Abstract Background Anterior cruciate ligament transection surgery (ACLT)-induced OA model was often used to investigate the molecular mechanism of knee osteoarthritis (KOA). Researches have shown that vascular endothelial growth factor (VEGF) played an important role in OA. The present study aimed to investigate the pathological changes after ACLT surgery and reveal the expression characteristics of the VEGF-A/VEGFR2 signaling pathway in this model. Methods Moderate KOA model was established by ACLT, and 1, 2, 4, 8, and 12 weeks after surgery, hematoxylin-eosin (HE) and Safranin-O(S-O) staining were used to detect the pathological changes in mouse knee cartilage, and the matrix biomarkers A Disintegrin and Metalloproteinase with Thrombospondin Motifs 5(ADAMTS5), Collagen II (COL-II) were detected using immunohistochemistry (IHC), CD31 was detected by immunofluorescence (IF) to show the vascular invasion in cartilage, and proteins expression of VEGF-A pathway were detected by Western blot (WB). Meanwhile, the inflammatory biomarkers cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in cartilage were detected by WB. Results ACLT surgery can lead to degeneration of cartilage in mice, and the characteristics of the lesion were time-dependent. The ADAMTS5-positive cells increased while COL-II decreased in OA cartilage with time, and new blood vessels labeled by CD31 can be seen from 1 week in OA cartilage, and increased in 8 and 12 weeks. The expression of VEGF-A, VEGFR2, COX-2, and iNOS were higher than control groups, which were basically consistent with the degree of osteoarthritis. Conclusions The degenerative degree of articular cartilage was time-dependent; angiogenesis and inflammation were important pathological changes of cartilage in KOA. The expression of the VEGF-A/VEGFR2 signaling pathway was basically correlated with the degree of KOA.

Download Full-text

Lipopolysaccharide activates innate immune responses in murine intestinal myofibroblasts through multiple signaling pathways

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00022.2008 ◽

2009 ◽

Vol 296 (3) ◽

pp. G601-G611 ◽

Cited By ~ 65

Author(s):

Kristen L. W. Walton ◽

Lisa Holt ◽

R. Balfour Sartor

Keyword(s):

Immune Responses ◽

Signaling Pathways ◽

P38 Mapk ◽

Western Blotting ◽

Pi3 Kinase ◽

Innate Immune ◽

Innate Immune Responses ◽

Fold Induction ◽

Cox 2 ◽

Multiple Signaling

Myofibroblasts (MF) play an important role in intestinal wound healing. A compromised epithelial barrier exposes intestinal subepithelial MF to luminal bacterial products. However, responses of murine intestinal MF to bacterial adjuvants and potential roles of intestinal MF in innate immune responses are not well defined. Our aims in this study were to determine innate immune responses and intracellular signaling pathways of intestinal MF exposed to LPS, a prototypic Toll-like receptor (TLR) ligand. Expression of TLR4 in primary murine intestinal MF cultures was confirmed by RT-PCR and Western blotting. LPS-induced secretion of prostaglandin E2 (PGE2), interleukin (IL)-6, and keratinocyte-derived chemokines (KC) was measured by ELISA. Intracellular responses to LPS were assessed by Western blotting for NF-κB p65, Iκ-Bα, Akt, p38 MAP kinase, and cyclooxygenase-2 (COX-2). LPS induced rapid phosphorylation of NF-κB p65, Akt, and p38 MAPK and degradation of Iκ-Bα. LPS induced expression of COX-2 and secretion of PGE2 (2.0 ± 0.8-fold induction vs. unstimulated cells), IL-6 (6.6 ± 0.4-fold induction), and KC (12.5 ± 0.4-fold induction). Inhibition of phosphoinositide-3 (PI3)-kinase, p38 MAPK, or NF-κB pathways reduced LPS-induced PGE2, IL-6, and KC secretion. These studies show that primary murine intestinal MF respond to LPS, evidenced by activation of NF-κB, PI3-kinase, and MAPK signaling pathways and secretion of proinflammatory molecules. Inhibition of these pathways attenuated LPS-dependent PGE2, IL-6, and KC production, indicating that LPS activates MF by multiple signaling pathways. These data support the hypothesis that MF are a component of the innate immune system and may exert paracrine effects on adjacent epithelial and immune cells by responding to luminal bacterial adjuvants.

Download Full-text