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Previous studies have suggested that the Janus kinase (JAK)/signal transducers and activators of transcription (STAT) pathway is involved in hyperglycemia‑induced lung injury. The present study aimed to investigate the roles of suppressor of cytokine signaling3 (SOCS3) in the regulation of JAK2/STAT3 activation following high glucose (HG) treatment in A549 human pulmonary epithelial cells. Cell viability was evaluated using Cell Counting Kit-8 and lactate dehydrogenase assays. HG‑induced inflammatory injury in A549 cells was assessed through the evaluation of interleukin‑6 (IL‑6) and tumor necrosis factor‑α (TNF‑α) levels using ELISA. The protein expression levels of SOCS3, JAK2, STAT3, phosphorylated (p)‑JAK2 and p‑STAT3 were determined using western blot analysis. Cellular viability was significantly decreased, whereas IL‑6 and TNF‑α levels were significantly increased, following HG stimulation of A549 cells. In addition, the protein levels of SOCS3, p‑JAK2 and p‑STAT3 were significantly increased in HG‑treated cells. Treatment with the JAK2/STAT3 inhibitor tyrphostin AG490, or SOCS3 overexpression, appeared to prevent the HG‑induced alterations in protein expression. Furthermore, cellular viability was enhanced, whereas the levels of proinflammatory cytokines were suppressed. These finding suggested the involvement of the SOCS3/JAK2/STAT3 signaling pathway in HG‑induced responses in lung cells. Therefore, it may be hypothesized that the inhibition of the JAK2/STAT3 pathway through SOCS3 overexpression may prevent hyperglycemia‑induced lung injury, and may have therapeutic potential for the treatment of patients with diabetic lung injury.

Although the mechanism remains unclear, ischemic post‑conditioning (IPO) is a promising approach to combat myocardial ischemia reperfusion (IR) injury; however, it has been proven ineffective in diabetes. The present study aimed to identify whether hyperglycemia‑induced AMP‑activated protein kinase (AMPK) inhibition contributes to the ineffectiveness of IPO via autophagy attenuation in diabetic hearts. Diabetic and non‑diabetic rats were subjected to myocardial IR and/or IPO with/without treatment with the AMPK activator A‑769662 and/or autophagy inhibitor 3‑methyladenine (3‑MA). Rat cardiomyocyte H9c2 cells were pretreated with A‑769662 and/or 3‑MA, and subjected to hypoxia reoxygenation (HR) or hypoxia post‑conditioning (HPO). The degree of injury to the myocardium/cells, oxidative stress, AMPK/mammalian target of rapamycin (mTOR) signaling and autophagy status were analyzed. In diabetic rats the myocardial infarct size, and creatine kinase‑MB and malondialdehyde release, were increased compared with non‑diabetic rats, concomitant with increased cardiac dysfunction and decreased cardiac superoxide dismutase activity, AMPK phosphorylation and autophagy following IR. IPO attenuated myocardial infarct size, increased AMPK phosphorylation and enhanced autophagy in non‑diabetic animals. A‑769662 (6.0 mg/kg) restored IPO cardioprotection in diabetic rats. In vitro, HPO combined with A‑769662 decreased HR injury in H9c2 cells exposed to high glucose, as evidenced by decreased lactic dehydrogenase expression and oxidative stress, accompanied by increased cell viability and autophagy. The A‑769662‑mediated restoration of IPO/HPO cardioprotection was completely reversed by treatment with the autophagy inhibitor 3‑MA. In conclusion, AMPK inhibition, by decreasing autophagy, may be a mechanism through which diabetic hearts are rendered unresponsive to IPO cardioprotection.

Objective In this study, the neuroprotective mechanism of 2-arachidonoylglycerol 2-AG against non-caspase-dependent apoptosis in mice hippocampal neurons following MCAO was investigated. Method One hundred and fifty healthy clean male C57BL/6 mice were randomly divided into 3 groups: sham group, model group and 2-AG treatment group, 50 mice in each group. A modified Zea Longa method was used to establish a model of middle cerebral artery occlusion (MCAO) in mice. The apoptosis rate and mitochondrial membrane potential of hippocampal nerve cells were measured by flow cytometry. The mRNA expressions of AIF, Endo G and BNIP3 in hippocampal tissues were determined by qPCR. Western blot was used to determine the protein expressions of AIF, Endo G and BNIP3 in the mitochondria of hippocampal tissue. Results The apoptosis rate of hippocampal neurons in the group treated with 2-AG was significantly lower than that of the model (P

Long non-coding (lncRNA) MALAT1 can be increased by hypoxia or ischemic limbs. Also, downregulation of MALAT1 contributes to reduction of cardiomyocyte apoptosis. However, the functional involvement of MALAT1 in myocardial ischemia-reperfusion (I/R) injury has not been defined. This study investigated the functional involvement of lncRNA-MALAT1 in cardioprotective effects of fentanyl. HL-1, a cardiac muscle cell line from the AT-1 mouse atrial cardiomyocyte tumor lineage was pre-treated with fentanyl and generated cell model of hypoxia-reoxygenation (H/R). Relative expression of MALAT1, miR-145, and Bnip3 mRNA in cells was determined by quantitative real-time PCR. Cardiomyocyte H/R injury was indicated by lactate dehydrogenase (LDH) release and cell apoptosis. The results showed that fentanyl abrogates expression of responsive gene for H/R and induces downregulation of MALAT1 and Bnip3 and upregulation of miR-145. We found that miR-145/Bnip3 pathway was negatively regulated by MALAT1 in H/R-HL-1 cell with or without fentanyl treatment. Moreover, both MALAT1 overexpression and miR-145 knockdown reverse cardioprotective effects of fentanyl, as indicated by increase in LDH release and cell apoptosis. The reversal effect of MALAT1 for fentanyl is confirmed in cardiac ischemia/reperfusion (I/R) mice. In summary, lncRNA-MALAT1 is sensitive to H/R injury and abrogates cardioprotective effects of Fentanyl by negatively regulating miR-145/Bnip3 pathway.

Glomerular matrix accumulation is a hallmark of diabetic renal disease. Serine/threonine kinase PKC-β1 mediates glucose-induced Akt S473 phosphorylation, RhoA activation, and transforming growth factor (TGF)-β1 upregulation and finally leads to matrix upregulation in mesangial cells (MCs). It has been reported that glucose-induced PKC-β1 activation is dependent on caveolin-1 and the presence of intact caveolae in MCs; however, whether activated PKC-β1 regulates caveolin-1 expression and phosphorylation are unknown. Here, we showed that, although the caveolin-1 protein level had no significant change, the PKC-β-specific inhibitor LY-333531 blocked caveolin-1 Y14 phosphorylation in high glucose (HG)-treated MCs and in the renal cortex of diabetic rats. The Src-specific inhibitor SU-6656 prevented the HG-induced association between PKC-β1 and caveolin-1 and PKC-β1 membrane translocation, whereas PKC-β1 small interfering RNA failed to block Src activation, indicating that Src kinase is upstream of PKC-β1 activation. Although LY-333531 blocked PKC-β1 membrane translocation, it had no effect on the PKC-β1/caveolin-1 association, suggesting that PKC-β1 activation requires the interaction of caveolin-1 and PKC-β1. PKC-β1-mediated Akt S473 phosphorylation, RhoA activation, and fibronectin upregulation in response to HG were prevented by SU-6656 and nonphosphorylatable mutant caveolin-1 Y14A. In conclusion, Src activation by HG mediates the PKC-β1/caveolin-1 association and PKC-β1 activation, which assists in caveolin-1 Y14 phosphorylation by Src kinase. The downstream effects, including Akt S473 phosphorylation, RhoA activation, and fibronectin upregulation, require caveolin-1 Y14 phosphorylation. Caveolin-1 is thus an important mediator of the profibrogenic process in diabetic renal disease.