Mechanism of paeoniflorin inhibiting apoptosis of hippocampal neurons of rats induced by lead acetate / 中华劳动卫生职业病杂志

Objective: To investigate the effect and underlying mechanism of paeoniflorin on hippocampal neuron apoptosis induced by lead acetate. Methods: In September 2020, primary hippocampal neuronal cells were isolated and cultured from fetal rats, and identified using cellular immunofluorescent. MTT assay was used to measure the cell viability to determine the concentration and time of lead acetate-induced hippocampal neuron apoptosis. MTT was also used to evaluate the effect of paeoniflorin concentration on the apoptosis of hippocampal neurons induced by lead acetate. According to the results, different concentrations of paeoniflorin were selected to intervene hippocampal neuron cells, after 24 h, lead acetate was added to the cells, meanwhile, blank and model groups were set up, the content of reactive oxygen species (ROS) , superoxide dismutase (SOD) , lactate dehydrogenase (LDH) , malondialdehyde (MDA) and Caspase-3 were measured. Extracellular signal regulated kinase (ERK) , phosphorylated ERK (p-ERK) , p38 mitogen -activated protein kinases (p38MAPK) , phosphorylated p38MAPK (p-p38MAPK) , c-Jun N-terminal kinase (JNK) and phosphorylated JNK (p-JNK) protein expression in hippocampal neuronal cells were determined by Western blotting. Results: The isolated and cultured hippocampal neurons were identified by immunofluorescence chemical staining and then treated with lead acetate, MTT results showed that lead acetate had the best toxicity effect when treated for 24 h at a concentration of 25 μmol/L. Paeoniflorin showed no cytotoxic effect on hippocampal neuronal cells when the concentrations below 80 μmol/L. Compared with the model group, the activity of hippocampal neuronal cells was significantly increased after treating with 20, 40 or 80 μmol/L paeoniflorin (P<0.05) . Compared with the blank group, the ROS activity, LDH release level, MDA content and caspase-3 content were significantly increased (P<0.01) , and the SOD activity was significantly decreased (P< 0.01) in the hippocampal neuronal cells of the model group. Compared with the model group, the ROS activity, LDH release level, MDA content and caspase-3 content were obviously decreased (P<0.05) , SOD activity was significantly increased (P <0.01) after hippocampal neuronal cells were treated with 40 or 80 μmol/L paeoniflorin. Relative to the model group, the ratio of p-ERK/ERK were significantly up-regulated (P<0.01) , while the ratios of p-p38MAPK/p38MAPK and p-JNK/JNK were significantly down-regulated after hippocampal neuronal cells were treated with 40 or 80 μmol/L paeoniflorin (P<0.05) . Conclusion: Paeoniflorin may down-regulate the expression of p-p38MAPK and p-JNK protein, up-regulate the expression of p-ERK protein, and inhibit the apoptosis of hippocampal neurons induced by lead acetate through the MAPK signaling pathway.

Ca mobilization and signaling pathways induced by rRgpB in human gingival fibroblast / 浙江大学学报·医学版

: To assess the () recombinant gingivalis gingipain R2 (rRgpB)-induced Ca mobilization in human gingival fibroblast (HGF) mediated by protease-activated receptor (PAR) and its downstream signal transduction pathways. : Flow cytometry was used to detect the expression of PAR in HGF. The proliferation of HGF was measured by CCK-8. The dynamic changes of intracellular Ca concentration in HGF induced by rRgpB and the blocking effect of PAR-1 antagonist were observed by laser confocal microscopy. Western blot was performed to determine the phosphorylation levels of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK) 1/2, p38 mitogen-activated protein kinase (p38 MAPK) and p65 in HGF. : PAR-1 and PAR-3 were expressed in HGF, and the rRgpB could promote the proliferation of HGF. rRgpB caused a transient increase in [Ca], which could be completely suppressed by vorapaxar, a PAR-1 antagonist. The phosphorylation levels of JNK, ERK1/2 and p65 were significantly up-regulated after the induction of rRgpB for and (all <0.05), which was completely inhibited by vorapaxar. However, the phosphorylation level of p38 MAPK had no significant change after rRgpB stimulation. : rRgpB causes an increase in [Ca] in HGF mediated by PAR-1. JNK, ERK1/2 and nuclear factor-κB may be involved in intracellular signal transduction after PAR-1 activation.

Involvement of HSP90 in ischemic postconditioning-induced cardioprotection by inhibition of the complement system, JNK and inflammation

Abstract Purpose To investigate whether heat shock protein 90 (HSP90) is involved in complement regulation in ischemic postconditioning (IPC). Methods The left coronary artery of rats underwent 30 min of occlusion, followed by 120 min of reperfusion and treatment with IPC via 3 cycles of 30s reperfusion and 30s occlusion. The rats were injected intraperitoneally with 1 mg/kg HSP90 inhibitor geldanamycin (GA) after anesthesia. Eighty rats were randomly divided into four groups: sham, ischemia-reperfusion (I/R), IPC and IPC + GA. Myocardial infarct size, apoptosis index and the expression of HSP90, C3, C5a, tumor necrosis factor (TNF)-alpha, interleukin (IL)-1β and c-Jun N-terminal kinase (JNK) were assessed. Results Compared with the I/R injury, the IPC treatment significantly reduced infarct size, release of troponin T, creatine kinase-MB, and lactate dehydrogenase, and cardiomyocyte apoptosis. These beneficial effects were accompanied by a decrease in TNF-α, IL-1β, C3, C5a and JNK expression levels. However, all these effects were abrogated by administration of the HSP90 inhibitor GA. Conclusion HSP90 exerts a profound effect on IPC cardioprotection, and may be linked to the inhibition of the complement system and JNK, ultimately attenuating I/R-induced myocardial injury and apoptosis.

N-acetyl-l-cysteine controls osteoclastogenesis through regulating Th17 differentiation and RANKL in rheumatoid arthritis

BACKGROUND/AIMS: This study aimed to determine the regulatory role of N-acetyl-l-cysteine (NAC), an antioxidant, in interleukin 17 (IL-17)-induced osteoclast differentiation in rheumatoid arthritis (RA). METHODS: After RA synovial fibroblasts were stimulated by IL-17, the expression and production of receptor activator of nuclear factor κ-B ligand (RANKL) was determined by real-time polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA). Osteoclastogenesis was also determined after co-cultures of IL-17-stimulated RA synovial fibroblasts, Th17 cells and various concentrations of NAC with monocytes. After human peripheral CD4⁺ T cells were cultured with NAC under Th17 condition, IL-17, interferon γ, IL-4, Foxp3, RANKL, and IL-2 expression and production was determined by flow cytometry or ELISA. RESULTS: When RA synovial fibroblasts were stimulated by IL-17, IL-17 stimulated the production of RANKL, and NAC reduced the IL-17-induced RANKL production in a dose-dependent manner. NAC decreased IL-17-activated phosphorylation of mammalian target of rapamycin, c-Jun N-terminal kinase, and inhibitor of κB. When human peripheral blood CD14⁺ monocytes were cultured with macrophage colony-stimulating factor and IL-17 or RANKL, osteoclasts were differentiated, and NAC reduced the osteoclastogenesis. After human peripheral CD4⁺ T cells were co-cultured with IL-17-pretreated RA synovial fibroblasts or Th17 cells, NAC reduced their osteoclastogenesis. Under Th17 polarizing condition, NAC decreased Th17 cell differentiation and IL-17 and RANKL production. CONCLUSIONS: NAC inhibits the IL-17-induced RANKL production in RA synovial fibroblasts and IL-17-induced osteoclast differentiation. NAC also reduced Th17 polarization. NAC could be a supplementary therapeutic option for inflammatory and bony destructive processes in RA.

Role of JNK and ERK1/2 MAPK signaling pathway in testicular injury of rats induced by di-N-butyl-phthalate (DBP)

BACKGROUND: Di-N-butyl-phthalate (DBP) is an endocrine disrupting substance. We investigated the adverse effect of DBP on testis of male rat and reveal its potential mechanism of MAPK signaling pathway involved this effect in vivo and in vitro. Gonadal hormone, sperm quality, morphological change and the activation status of JNK, ERK1/2 and p38 was determined in vivo. Primary Sertoli cell was established and cultivated with JNK, ERK1/2 inhibitors, then determine the cell viability, apoptosis and the expression of p-JNK, p-ERK1/2. Data in this study were presented as mean ± SD and determined by one-way analysis of variance (ANOVA) followed by Bonferroni's test. Difference was considered statistically significant at P < 0.05. RESULTS: In vivo experiment, DBP impaired the normal structure of testicular tissue, reduced testosterone levels in blood serum, decreased sperm count and increased sperm abnormality, p-ERK1/2 and p-JNK in rat testicular tissue increased in a dose-dependent manner. In vitro studies, DBP could decrease the viability of Sertoli cells and increase p-ERK1/2 and p-JNK. Cell apoptosis in SP600125 + DBP group was significantly lower than in DBP group (P < 0.05). p-JNK was not significantly decreased in SP600125 + DBP group, while p-ERK1/2 was significantly decreased in U0126 + DBP group. CONCLUSIONS: These results suggest that DBP can lead to testicular damage and the activation of ERK1/2 and JNK pathways, the JNK signaling pathway may be primarily associated with its effect.

Effects of MD2 gene silencing on high glucose-induced proliferation inhibition, apoptosis and inflammation in rat cardiomyocytes / 中国应用生理学杂志

OBJECTIVE@#To investigate the effects of myeloid differentiation-2 (MD2) gene silencing on high glucose-induced proliferation inhibition, apoptosis and inflammation in rat cardiomyocytes.@*METHODS@#The immortalized rat cardiomyocyte cell line H9C2 were transfected with MD2 small interfering RNA (si-MD2) and negative control for 24 h, then stimulated with high glucose (HG) for 48 h. RT-qPCR was performed to detect the mRNA levels of MD2 and inflammatory factors TNF-α, IL-1β and IL-6. MTS and flow cytometry were used to evaluate cell proliferation, cell cycle and apoptosis rate. Western blot was used to detect protein expression levels and phosphorylation levels.@*RESULTS@#The mRNA and protein levels of MD2 in H9C2 cells were dramatically decreased after transfected with si-MD2 (P＜0.01). After stimulation of high glucose, the mRNA levels of inflammatory factors, the cells in G0/G1 phase , the cell apoptosis rate and the protein level of cleaved Caspase-3 were significantly increased, while the cell proliferation ability was decreased (P＜0.01). MD2 gene silencing antagonized the effects of high glucose on cell proliferation, cell cycle, cell apoptosis and the mRNA levels of TNF-α, IL-1β , IL-6(P＜0.05). Western blot analysis showed that the phosphorylation levels of extracellular signal-regulated kinase(ERK1/2), P38 mitogen-activated protein kinase(P38 MAPK) and C-Jun N-terminal kinase(JNK) protein were increased significantly in H9C2 cells treated with high glucose, which could be reversed by silencing of MD2 (P＜0.01).@*CONCLUSION@#This study demonstrates that MD2 gene silencing reverses high glucose-induced myocardial inflammation, apoptosis and proliferation inhibition via the mechanisms involving suppression of ERK, P38 MAPK, JNK signaling pathway.

Baicalein Treatment Promotes Osteoblast Proliferation and Osteogenic Differentiation through Activation of Immediate Early Response 3 / 치위생과학회지

BACKGROUND: The primary aims of periodontal disease treatment is to remove dental plaque and calculus, the main causes of tooth loss, and restore periodontal tissue destroyed by inflammation. Periodontal disease treatment should also help maintain the alveolar bone, alleviate inflammation, and promote periodontal ligament cell proliferation, which is essential for tissue regeneration. Conventional antibiotics and anti-inflammatories have adverse side effects, especially during long-term use, so there is a need for adjunct treatment agents derived from natural products. The purpose of this study was to investigate whether the herbal flavone baicalein has the osteogenic activity under inflammatory conditions, and assess the involvement of osteoblast immediate early response 3 (IER3) expression.METHODS: Human osteoblastic MG-63 cells were cultured with the pro-inflammatory cytokines tumor necrosis factor α and interleukin 1β in the presence and absence of baicalein. Proliferation was assessed using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay, and expression of IER3 mRNA was assessed using real-time polymerase chain reaction. The expression of IER3 protein levels and activation of associated signal transduction pathways were assessed using western blotting.RESULTS: Baicalein increased IER3 mRNA and protein expression synergistically. In addition, baicalein reversed the suppression of cell proliferation, and the downregulation of osteogenic transcription factor runt-related transcription factor 2 and osterix induced by pro-inflammatory cytokines. Baicalein also upregulated the phosphorylation of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK 1/2). The upregulation of IER3 by pro-inflammatory cytokines was blocked by pretreatment with inhibitors of AKT, p38, JNK, and ERK 1/2.CONCLUSION: Baicalein mitigates the deleterious responses of osteoblasts to pro-inflammatory cytokines. Further, IER3 enhanced the effect of baicalein via activation of AKT, p38, JNK, and ERK pathways.

Propofol protects human cardiac AC16 cells from CoCl2-induced hypoxic injury / 中南大学学报(医学版)

To explore the effect of propofol on human cardiac AC16 cells under CoCl2-induced hypoxic injury and the possible mechanisms.
 Methods: Human AC16 cardiomyocytes were treated with cobalt chloride (CoCl2) to mimic hypoxic condition in cultured cardiomyocytes. The AC16 cells were divided into 3 groups: a control group, a CoCl2 hypoxia group (CoCl2 group), and a propofol+CoCl2 group (propofol+ CoCl2 group). The cell viability was assessed by cell counting kit-8 (CCK-8). Cell apoptosis ratio (AR) and the mitochondrial membrane potential (Δψm) were detected by flow cytometry. The reactive oxygen species (ROS) production in AC16 cells were determined with the ROS-sensitive fluorescent probe. Meanwhile, total intracellular levels of malondialdehyde (MDA) and superoxide dismutase (SOD) in AC16 cells were detected with commercially available kits. Western blot was used to evaluate the activation of c-Jun N-terminal kinase (JNK) and p38 signaling pathways.
 Results: 1) Compared with the control group, AC16 cell viability was decreased significantly in the CoCl2 group following the treatment with 500 μmol/L CoCl2 (P<0.01); 2) Compared with the control group, AR value in AC16 cells was increased significantly in the CoCl2 group, while Δψm was decreased significantly (all P<0.01). Compared with the CoCl2 group, AR value in AC16 cells was decreased significantly in the propofol+CoCl2 group, while Δψm was increased significantly (both P<0.05); 3) Compared with the control group, the levels of ROS and MDA were increased significantly, and the level of SOD was significantly decreased in the CoCl2 group (all P<0.01). Compared with the CoCl2 group, the ROS and MDA levels in the propofol+CoCl2 group were increased significantly and the SOD levels were decreased significantly (all P<0.05); 4) Compared with the control group, the phosphorylation levels of JNK and p38 were increased significantly (both P<0.05) in the CoCl2 group. Compared with the CoCl2 group, the phosphorylation levels of JNK and p38 were decreased significantly in the propofol+CoCl2 group (both P<0.05).
 Conclusion: The pretreatment with propofol may protect human cardiac AC16 cells from the chemical hypoxia-induced injury through regulation of JNK and p38 signaling pathways.

7,8,4′-Trihydroxyisoflavone, a Metabolized Product of Daidzein, Attenuates 6-Hydroxydopamine-Induced Neurotoxicity in SH-SY5Y Cells

Daidzein isolated from soybean (Glycine max) has been widely studied for its antioxidant and anti-inflammatory activities. However, the protective effects of 7,8,4′-trihydroxyisoflavone (THIF), a major metabolite of daidzein, on 6-hydroxydopamine (OHDA)-induced neurotoxicity are not well understood. In the current study, 7,8,4′-THIF significantly inhibited neuronal cell death and lactate dehydrogenase (LDH) release induced by 6-OHDA in SH-SY5Y cells, which were used as an in vitro model of Parkinson's disease (PD). Moreover, pretreatment with 7,8,4′-THIF significantly increased the levels of superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) and decreased malondialdehyde (MDA) activity in 6-OHDA-induced SH-SY5Y cells. In addition, 7,8,4′-THIF significantly recovered 6-OHDA-induced cleaved caspase-3, cleaved caspase-9, cleaved poly-ADP-ribose polymerase (PARP), increased Bax, and decreased Bcl-2 levels. Additionally, 7,8,4′-THIF significantly restored the expression levels of phosphorylated c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase 1/2 (ERK 1/2), phosphatidylinositol 3-kinases (PI3K)/Akt, and glycogen synthase kinase-3 beta (GSK-3β) in 6-OHDA-induced SH-SY5Y cells. Further, 7,8,4′-THIF significantly increased the reduced tyrosine hydroxylase (TH) level induced by 6-OHDA in SH-SY5Y cells. Collectively, these results suggest that 7,8,4′-THIF protects against 6-OHDA-induced neuronal cell death in cellular PD models. Also, these effects are mediated partly by inhibiting activation of the MAPK and PI3K/Akt/GSK-3β pathways.

Cyclosporin A aggravates hydrogen peroxide-induced cell death in kidney proximal tubule epithelial cells / 대한해부학회지

Cyclosporin A (CsA) does not only exert a toxic effect on kidney parenchymal cells, but also protects them against necrotic cell death by inhibiting opening of mitochondrial permeability transition pore. However, whether CsA plays a role in hydrogen peroxide-induced kidney proximal tubular cell death is currently unclear. In the present study, treatment with CsA further increased apoptosis and necrosis in HK-2 human kidney proximal tubule epithelial cells during exposure to hydrogen peroxide. In addition, hydrogen peroxide-induced p53 activation and BH3 interacting-domain death agonist (BID) expression were higher in CsA-treated cells than those in non-treated cells, whereas hydrogen peroxide-induced activation of mitogen-activated protein kinases including p38, c-Jun N-terminal kinase, and extracellular signal-regulated kinase and activation of protein kinase B were not significantly altered by treatment with CsA. In oxidant-antioxidant system, reactive oxygen species (ROS) production induced by hydrogen peroxide was further enhanced by treatment with CsA. However, expression levels of antioxidant enzymes including manganese superoxide dismutase, copper/zinc superoxide dismutase, and catalase were not altered by treatment with hydrogen peroxide or CsA. Treatment with CsA further enhanced mitochondrial membrane potential induced by exposure to hydrogen peroxide, although it did not alter endoplasmic reticulum stress based on expression of glucose-regulated protein 78 and 94. Taken together, these data suggest that CsA can aggravate hydrogen peroxide-induced cell death through p53 activation, BID expression, and ROS production.

Mannosylerythritol lipids ameliorate ultraviolet A-induced aquaporin-3 downregulation by suppressing c-Jun N-terminal kinase phosphorylation in cultured human keratinocytes

Mannosylerythritol lipids (MELs) are glycolipids and have several pharmacological efficacies. MELs also show skin-moisturizing efficacy through a yet-unknown underlying mechanism. Aquaporin-3 (AQP3) is a membrane protein that contributes to the water homeostasis of the epidermis, and decreased AQP3 expression following ultraviolet (UV)-irradiation of the skin is associated with reduced skin moisture. No previous study has examined whether the skin-moisturizing effect of MELs might act through the modulation of AQP3 expression. Here, we report for the first time that MELs ameliorate the UVA-induced downregulation of AQP3 in cultured human epidermal keratinocytes (HaCaT keratinocytes). Our results revealed that UVA irradiation decreases AQP3 expression at the protein and messenger RNA (mRNA) levels, but that MEL treatment significantly ameliorated these effects. Our mitogen-activated protein kinase inhibitor analysis revealed that phosphorylation of c-Jun N-terminal kinase (JNK), but not extracellular signal-regulated kinase or p38, mediates UVA-induced AQP3 downregulation, and that MEL treatment significantly suppressed the UVA-induced phosphorylation of JNK. To explore a possible mechanism, we tested whether MELs could regulate the expression of peroxidase proliferator-activated receptor gamma (PPAR-γ), which acts as a potent transcription factor for AQP3 expression. Interestingly, UVA irradiation significantly inhibited the mRNA expression of PPAR-γ in HaCaT keratinocytes, whereas a JNK inhibitor and MELs significantly rescued this effect. Taken together, these findings suggest that MELs ameliorate UVA-induced AQP3 downregulation in HaCaT keratinocytes by suppressing JNK activation to block the decrease of PPAR-γ. Collectively, our findings suggest that MELs can be used as a potential ingredient that modulates AQP3 expression to improve skin moisturization following UVA irradiation-induced damage.

Compound K Inhibits Interleukin-1β-induced Expression of Inflammatory Mediators and Matrix Metalloproteinases by Inhibiting Mitogen-activated Protein Kinase Activation in Chondrocytes

OBJECTIVE: This study examined the anti-inflammatory and chondroprotective effects of compound K (CK), a ginsenoside metabolite, on chondrocytes from osteoarthritis (OA) patients following stimulation with interleukin (IL)-1β. METHODS: Articular cartilage samples were obtained from six OA patients undergoing total knee replacement surgery. Nitric oxide (NO) production was measured by the Griess reaction. Subsequently, the mRNA and protein levels of matrix metalloproteinases (MMPs), inducible NO synthase (iNOS), and mitogen-activated protein kinases (MAPKs) were examined by a reverse transcription-polymerase chain reaction and western blot analysis. Cartilage degradation was assessed using a glycosaminoglycan (GAG) assay. RESULTS: CK inhibited IL-1β-induced NO production and iNOS expression in a dose-dependent manner. In addition, it inhibited the IL-1 β-stimulated release of MMP-1, -3, and -13 and tissue inhibitor of matrix metalloproteinase-1 from OA patient chondrocytes. In addition, CK effectively suppressed the IL-1β-induced phosphorylation of p38, extracellular signal-regulated kinase-1/2, and c-Jun N-terminal kinase MAPKs. Moreover, the IL-1β-mediated release of GAG was inhibited by CK in a dose-dependent manner. CONCLUSION: CK inhibited the IL-1β-induced expression of inflammatory mediators and MMPs by, at least in part, inhibiting MAPK activation, and has potential as a therapeutic agent for the treatment of OA.

Expression of Fibroblast Growth Factor 21 and β-Klotho Regulates Hepatic Fibrosis through the Nuclear Factor-κB and c-Jun N-Terminal Kinase Pathways

BACKGROUND/AIMS: Fibroblast growth factor (FGF) 21 is associated with hepatic inflammation and fibrosis. However, little is known regarding the effects of inflammation and fibrosis on the β-Klotho and FGF21 pathway in the liver. METHODS: Enrolled patients had biopsy-confirmed viral or alcoholic hepatitis. FGF19, FGF21 and β-Klotho levels were evaluated using enzyme-linked immunosorbent assay, real-time polymerase chain reaction, and Western blotting. Furthermore, we explored the underlying mechanisms for this process by evaluating nuclear factor-κB (NF-κB) and c-Jun N-terminal kinase (JNK) pathway involvement in Huh-7 cells. RESULTS: We observed that the FGF19 and FGF21 serum and mRNA levels in the biopsied liver tissue gradually increased and were correlated with fibrosis stage. Inflammatory markers (interleukin 1β [IL-1β], IL-6, and tumor necrosis factor-α) were positively correlated, while β-Klotho expression was negatively correlated with the degree of fibrosis. In Huh-7 cells, IL-1β increased FGF21 levels and decreased β-Klotho levels. NF-κB and JNK inhibitors abolished the effect of IL-1β on both FGF21 and β-Klotho expression. FGF21 protected IL-1β-induced growth retardation in Huh-7 cells. CONCLUSIONS: These results indicate that the inflammatory response during fibrogenesis increases FGF21 levels and suppresses β-Klotho via the NF-κB and JNK pathway. In addition, FGF21 likely protects hepatocytes from hepatic inflammation and fibrosis.

Beneficial Role of Hydrogen Sulfide in Renal Ischemia Reperfusion Injury in Rats

PURPOSE: Hydrogen sulfide (H2S) is an endogenous gaseous molecule with important physiological roles. It is synthesized from cysteine by cystathionine γ-lyase (CGL) and cystathionine β-synthase (CBS). The present study examined the benefits of exogenous H2S on renal ischemia reperfusion (IR) injury, as well as the effects of CGL or CBS inhibition. Furthermore, we elucidated the mechanism underlying the action of H2S in the kidneys. MATERIALS AND METHODS: Thirty male Sprague-Dawley rats were randomly assigned to five groups: a sham, renal IR control, sodium hydrosulfide (NaHS) treatment, H2S donor, and CGL or CBS inhibitor administration group. Levels of blood urea nitrogen (BUN), serum creatinine (Cr), renal tissue malondialdehyde (MDA), and superoxide dismutase (SOD) were estimated. Histological changes, apoptosis, and expression of mitogen-activated protein kinase (MAPK) family members (extracellular signal-regulated kinase, c-Jun N-terminal kinase, and p38) were also evaluated. RESULTS: NaHS attenuated serum BUN and Cr levels, as well as histological damage caused by renal IR injury. Administration of NaHS also reduced oxidative stress as evident from decreased MDA, preserved SOD, and reduced apoptotic cells. Additionally, NaHS prevented renal IR-induced MAPK phosphorylation. The CGL or CBS group showed increased MAPK family activity; however, there was no significant difference in the IR control group. CONCLUSION: Exogenous H2S can mitigate IR injury-led renal damage. The proposed beneficial effect of H2S is, in part, because of the anti-oxidative stress associated with modulation of the MAPK signaling pathways.

Astragalus polysaccharides decrease proliferation, migration, and invasion but increase apoptosis of human osteosarcoma cells by up-regulation of microRNA-133a

Osteosarcoma (OS) has a high incidence, malignity, and frequency of recurrence and metastasis. In this study, we aimed to explore the potential anti-cancer effects of Astragalus polysaccharides (APS) on human OS MG63 cells as well as underlying mechanisms. Viability of MG63 cells was assessed by CCK-8 assay to determine the adequate concentration of APS. Then, effects of APS on MG63 cell proliferation, cell cycle distribution, apoptosis, and migration and invasion were analyzed by BrdU incorporation, PI staining, flow cytometry, and transwell assays, respectively. The expression levels of proteins involved in these physiological processes were assessed by western blot analysis. Afterwards, miR-133a level in APS-treated cells was determined by qRT-PCR, and whether APS affected MG63 cells through regulation of miR-133a was determined. Finally, the activation of c-Jun N-terminal protein kinase (JNK) pathway was detected. We found that APS treatment suppressed the viability, proliferation, migration, and invasion of MG63 cells, as well as induced cell apoptosis. Moreover, APS enhanced the expression of miR-133a in MG63 cells. Knockdown of miR-133a reversed the APS treatment-induced MG63 cell proliferation, migration and invasion inhibition, as well as cell apoptosis. Furthermore, APS inactivated JNK pathway in MG63 cells. Knockdown of miR-133a reversed the APS treatment-induced inactivation of JNK pathway in MG63 cells. To conclude, APS repressed proliferation, migration, and invasion while induced apoptosis of OS MG63 cells by up-regulating miR-133a and then inactivating JNK pathway.

MAPK signaling pathway and erectile dysfunction / 中华男科学杂志

The MAPK signaling pathway plays a key role in the differentiation, proliferation and apoptosis of cells, and its family members mainly include extracellular signal-regulated kinase (ERK), stress-activated protein kinase (JNK), and p38 mitogen-activated protein kinase (p38MAPK). Recent studies have shown that the ERK, JNK and p38MAPK signaling pathways are closely associated with the development and progression of erectile dysfunction (ED). This review focuses on the correlation between the MAPK signaling pathway and ED.

Atorvastatin inhibits osteoclast differentiation by suppressing NF-κB and MAPK signaling during IL-1β-induced osteoclastogenesis

BACKGROUND/AIMS: To define the effect of statins on interleukin 1β (IL-1β)-induced osteoclastogenesis and elucidate the underlying mechanisms. METHODS: Bone marrow cells were obtained from 5-week-old male ICR (Institute for Cancer Research) mice, and they were cultured to differentiate them into osteoclasts with macrophage colony-stimulating factor and the receptor activator of nuclear factor (NF)-κB ligand in the presence or absence of IL-1β or atorvastatin. The formation of osteoclasts was evaluated by tartrate-resistant acid phosphatase (TRAP) staining and resorption pit assay with dentine slice. The molecular mechanisms of the effects of atorvastatin on osteoclastogenesis were investigated using reverse transcription polymerase chain reaction and immunoblotting for osteoclast specific molecules. RESULTS: Atorvastatin significantly reduced the number of TRAP-positive multinucleated cells as well as the bone resorption area. Atorvastatin also downregulated the expression of the NF of activated T-cell c1 messenger RNA and inhibited the expression of osteoclast-specific genes. A possible underlying mechanism may be that atorvastatin suppresses the degradation of the inhibitors of NF-κB and blocks the activation of the c-Jun N-terminal kinase, extracellular signal-regulated kinase, and p38; thus, implicating the NF-κB and mitogen-activated protein kinases pathway in this process. CONCLUSIONS: Atorvastatin is a strong inhibitor of inflammation-induced osteoclastogenesis in inflammatory joint diseases.

PDK2 promotes chondrogenic differentiation of mesenchymal stem cells by upregulation of Sox6 and activation of JNK/MAPK/ERK pathway

This study was undertaken to clarify the role and mechanism of pyruvate dehydrogenase kinase isoform 2 (PDK2) in chondrogenic differentiation of mesenchymal stem cells (MSCs). MSCs were isolated from femurs and tibias of Sprague-Dawley rats, weighing 300-400 g (5 females and 5 males). Overexpression and knockdown of PDK2 were transfected into MSCs and then cell viability, adhesion and migration were assessed. Additionally, the roles of aberrant PDK2 in chondrogenesis markers SRY-related high mobility group-box 6 (Sox6), type ΙΙ procollagen gene (COL2A1), cartilage oligomeric matrix protein (COMP), aggrecan (AGC1), type ΙX procollagen gene (COL9A2) and collagen type 1 alpha 1 (COL1A1) were measured by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). The expressions of c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK) and extracellular regulated protein kinase (ERK) were measured. Overexpressing PDK2 promoted cell viability, adhesion and inhibited cell migration in MSCs (all P<0.05). qRT-PCR assay showed a potent increase in the mRNA expressions of all chondrogenesis markers in response to overexpressing PDK2 (P<0.01 or P<0.05). PDK2 overexpression also induced a significant accumulation in mRNA and protein expressions of JNK, p38MAPK and ERK in MSCs compared to the control (P<0.01 or P<0.05). Meanwhile, silencing PDK2 exerted the opposite effects on MSCs. This study shows a preliminary positive role and potential mechanisms of PDK2 in chondrogenic differentiation of MSCs. It lays the theoretical groundwork for uncovering the functions of PDK2 and provides a promising basis for repairing cartilage lesions in osteoarthritis.

A High-fat Diet Induces a Loss of Midbrain Dopaminergic Neuronal Function That Underlies Motor Abnormalities

Movement defects in obesity are associated with peripheral muscle defects, arthritis, and dysfunction of motor control by the brain. Although movement functionality is negatively correlated with obesity, the brain regions and downstream signaling pathways associated with movement defects in obesity are unclear. A dopaminergic neuronal pathway from the substantia nigra (SN) to the striatum is responsible for regulating grip strength and motor initiation through tyrosine hydroxylase (TH) activity-dependent dopamine release. We found that mice fed a high-fat diet exhibited decreased movement in open-field tests and an increase in missteps in a vertical grid test compared with normally fed mice. This motor abnormality was associated with a significant reduction of TH in the SN and striatum. We further found that phosphorylation of c-Jun N-terminal kinase (JNK), which modulates TH expression in the SN and striatum, was decreased under excess-energy conditions. Our findings suggest that high calorie intake impairs motor function through JNK-dependent dysregulation of TH in the SN and striatum.

Expressions of JNK and p-JNK in advanced prostate cancer and their clinical implications / 中华男科学杂志

Objective@#To investigate the expressions of JNK and p-JNK in advanced prostate cancer (PCa) and benign prostatic hyperplasia (BPH) and their implications.@*METHODS@#Using immunohistochemistry, we detected the expressions of JNK and p-JNK proteins in 40 cases of paraffin wax-embedded PCa and 21 cases of BPH tissues and analyzed their relationships with advanced PCa and BPH as well as with the pathologic features of advanced PCa.@*RESULTS@#Statistically significant differences were not found in the positive expression rate of the JNK protein between BPH and PCa (42.86% vs 52.50%, P>0.05), non-metastatic and metastatic PCa (53.85% vs 51.85%, P >0.05), Gleason ≤7 and Gleason >7 (58.82% vs 47.82%, P >0.05), PSA ≤20 μg/L and PSA >20 μg/L (57.14% vs 51.52%, P >0.05), or survival >5 yr and survival ≤5 yr (60.00% vs 45.00%, P >0.05), nor in the expression level of p-JNK between BPH and PCa (33.33% vs 35.00%, P >0.05), non-metastatic and metastatic PCa (30.77% vs 37.03%, P >0.05), Gleason ≤7 and Gleason >7 (35.29% vs 34.78%, P >0.05), or PSA ≤20 μg/L and PSA >20 μg/L (43.75% vs 10.93%, P >0.05). However, the expression of p-JNK was significantly higher in the survival >5 yr than in the survival ≤5 yr group of the PCa patients (50.00% vs 20.00%, P <0.05).@*CONCLUSIONS@#PCa patients with highly expressed p-JNK have a longer survival time and the high positive rate of p-JNK is associated with the prognosis of PCa.