SP1-stimulated miR-208a-5p aggravates sepsis-induced myocardial injury via targeting XIAP.

The development of sepsis can lead to many organ dysfunction and even death. Myocardial injury is one of the serious complications of sepsis leading to death. New evidence suggests that microRNAs (miRNAs) play a critical role in infection myocardial injury. However, the mechanism which miR-208a-5p regulates sepsis-induced myocardial injury remains unclear. To mimic sepsis-induced myocardial injury in vitro, rat primary cardiomyocytes were treated with LPS. Cell viability and apoptosis were tested by CCK-8 and flow cytometry, respectively. The secretion of inflammatory factors was analyzed by ELISA. mRNA and protein levels were detected by RT-qPCR and Western blotting. The interaction among SP1, XIAP and miR-208a-5p was detected using dual luciferase report assay. Ultrasonic analysis and HE staining was performed to observe the effect of miR-208a-5p in sepsis-induced rats. Our findings indicated that miR-208a-5p expression in primary rat cardiomyocytes was increased by LPS. MiR-208a-5p inhibitor reversed LPS-induced cardiomyocytes injury through inhibiting the apoptosis. Furthermore, the inflammatory injury in cardiomyocytes was induced by LPS, which was rescued by miR-208a-5p inhibitor. In addition, downregulation of miR-208a-5p improved LPS-induced sepsis myocardial injury in vivo. Mechanistically, XIAP might be a target gene of miR-208a-5p. SP1 promoted transcription of miR-208a by binding to the miR-208a promoter region. Moreover, silencing of XIAP reversed the regulatory of miR-208a-5p inhibitor on cardiomyocytes injury. To sum up, those findings revealed silencing of miR-208a-5p could alleviate sepsis-induced myocardial injury, which would grant a new process for the treatment of sepsis.

Reduction of SIRT1-Mediated Epigenetic Upregulation of Nav1.7 Contributes to Oxaliplatin-Induced Neuropathic Pain.

BACKGROUND: Clinically, neuropathic pain is a severe side effect of oxaliplatin chemotherapy, which usually leads to dose reduction or cessation of treatment. Due to the unawareness of detailed mechanisms of oxaliplatin-induced neuropathic pain, it is difficult to develop an effective therapy and limits its clinical use. OBJECTIVES: The aim of the present study was to identify the role of sirtuin 1 (SIRT1) reduction in epigenetic regulation of the expression of voltage-gated sodium channels 1.7 (Nav1.7) in the dorsal root ganglion (DRG) during oxaliplatin-induced neuropathic pain. STUDY DESIGN: Controlled animal study. SETTING: University laboratory. METHODS: The von Frey test was performed to evaluate pain behavior in rats. Real-time quantitative polymerase chain reaction, western blotting, electrophysiological recording, chromatin immunoprecipitation, and small interfering RNA (siRNA) were used to illustrate the mechanisms. RESULTS: In the present study, we found that both the activity and expression of SIRT1 were significantly decreased in rat DRG following oxaliplatin treatment. The activator of SIRT1, resveratrol, not only increased the activity and expression of SIRT1, but also attenuated the mechanical allodynia following oxaliplatin treatment. In addition, local knockdown of SIRT1 by intrathecal injection of SIRT1 siRNA caused mechanical allodynia in naive rats. Besides, oxaliplatin treatment enhanced the action potential firing frequency of DRG neurons and the expression of Nav1.7 in DRG and activation of SIRT1 by resveratrol reversed this effect. Furthermore, blocking Nav1.7 by ProTx II (a selective Nav1.7 channel blocker) reversed oxaliplatin-induced mechanical allodynia. In addition, histone H3 hyperacetylation at the Nav1.7 promoter in DRG of rats following oxaliplatin treatment was significantly suppressed by activation of SIRT1 with resveratrol. Moreover, both the expression of Nav1.7 and histone H3 acetylation at the Nav1.7 promoter were upregulated in the DRG by local knockdown of SIRT1 with SIRT1 siRNA in naive rats. LIMITATIONS: More underlying mechanism(s) of SIRT1 reduction after oxaliplatin treatment needs to be explored in future research. CONCLUSIONS: These findings suggest that reduction of SIRT1-mediated epigenetic upregulation of Nav1.7 in the DRG contributes to the development of oxaliplatin-induced neuropathic pain in rats. The intrathecal drug delivery treatment of activating SIRT1 might be a novel therapeutic option for oxaliplatin-induced neuropathic pain.

Reduction of SIRT1 Mediates Monosodium Iodoacetate-Induced Osteoarthritic Pain by Upregulating p53 Expression in Rats.

BACKGROUND: Clinically, chronic pain is the most common and disabling symptom of osteoarthritis (OA). OA pain is associated with OA lesion of the knee and the plastic changes in the peripheral and central nervous systems. However, the central mechanisms involved at the spinal cord level are not fully understood. OBJECTIVES: The aim of this study was to identify the mechanism underlying the role of spinal cord Sirtuin 1 (SIRT1) in OA pain induced by intraarticular injection of monosodium iodoacetate (MIA) in rats. STUDY DESIGN: Controlled animal study. METHODS: MIA was injected intraarticularly into the rat knee joint for the induction of OA. The OA lesion of the knee was assessed by histopathological examination. The mechanical allodynia were measured over 21 days post-injection by von Frey filaments. The messenger RNA and protein levels of SIRT1 and p53 were determined by real-time quantitative polymerase chain reaction and western blotting, respectively. Involvement of SIRT1-mediated p53 expression in the development of MIA-persistent pain was studied using intrathecal (i.t.) injection of the SIRT1-activating molecule resveratrol and intraperitoneal (i.p.) injection of the p53 inhibitor pifithrin-mu (PTF-µ). RESULTS: MIA induced mechanical allodynia, decreased the expression of SIRT1, and upregulated the expression of p53 in the spinal dorsal horn. Consecutive i.t. injection of resveratrol or i.p. injection of PTF-µ alleviated the MIA-induced mechanical allodynia. Upregulation of dorsal horn SIRT1 expression by i.t. injection of resveratrol also inhibited the increase of dorsal horn p53 induced by MIA. Moreover, silencing of dorsal horn SIRT1 expression by i.t. administration of small interfering RNA SIRT1 into normal rats induced the mechanical allodynia and upregulation of p53 expression in the dorsal horn. LIMITATIONS: More underlying mechanism(s) of the role of p53 signaling pathway in OA pain need to be explored in future research. CONCLUSIONS: These findings suggest that the reduction of dorsal horn SIRT1 mediated upregulation of p53 expression, which plays a critical role in persistent pain induced by OA. The i.t. drug delivery treatments targeting the spinal cord SIRT1/p53 pathway might be novel therapeutic options for OA-induced persistent pain.

Individual and combined effects of GSTM1, GSTT1, and GSTP1 polymorphisms on lung cancer risk: A meta-analysis and re-analysis of systematic meta-analyses.

ABSTRACT: Thirty-five previous meta-analyses have been reported on the individual glutathione S-transferase M1 (GSTM1) present/null, glutathione S-transferase T1 (GSTT1) present/null, and glutathione S-transferase P1 (GSTP1) IIe105Val polymorphisms with lung cancer (LC) risk. However, they did not appraise the credibility and explore the combined effects between the 3 genes and LC risk.We performed a meta-analysis and re-analysis of systematic previous meta-analyses to solve the above problems.Meta-analyses of Observational Studies in Epidemiology guidelines were used. Moreover, we employed false-positive report probability (FPRP), Bayesian false discovery probability (BFDP), and the Venice criteria to verify the credibility of current and previous meta-analyses.Significantly increased LC risk was considered as "highly credible" or "positive" for GSTM1 null genotype in Japanese (odds ratio (OR) = 1.30, 95% confidence interval (CI) = 1.17-1.44, I2 = 0.0%, statistical power = 0.997, FPRP = 0.008, BFDP = 0.037, and Venice criteria: AAB), for GSTT1 null genotype in Asians (OR = 1.23, 95% CI = 1.12-1.36, I2 = 49.1%, statistical power = 1.000, FPRP = 0.051, BFDP = 0.771, and Venice criteria: ABB), especially Chinese populations (OR = 1.31, 95% CI = 1.16-1.49, I2 = 48.9%, Statistical power = 0.980, FPRP = 0.039, BFDP = 0.673, and Venice criteria: ABB), and for GSTP1 IIe105Val polymorphism in Asians (Val vs IIe: OR = 1.28, 95% CI = 1.17-1.42, I2 = 30.3%, statistical power = 0.999, FPRP = 0.003, BFDP = 0.183, and Venice criteria: ABB). Significantly increased lung adenocarcinoma (AC) risk was also considered as "highly credible" or "positive" in Asians for the GSTM1 (OR = 1.35, 95% CI = 1.22-1.48, I2 = 25.5%, statistical power = 0.988, FPRP < 0.001, BFDP < 0.001, and Venice criteria: ABB) and GSTT1 (OR = 1.36, 95% CI = 1.17-1.58, I2 = 30.2%, statistical power = 0.900, FPRP = 0.061, BFDP = 0.727, and Venice criteria: ABB) null genotype.This study indicates that GSTM1 null genotype is associated with increased LC risk in Japanese and lung AC risk in Asians; GSTT1 null genotype is associated with increased LC risk in Chinese, and GSTP1 IIe105Val polymorphism is associated with increased LC risk in Asians.

Yangfei Kongliu Formula, a compound Chinese herbal medicine, combined with cisplatin, inhibits growth of lung cancer cells through transforming growth factor-ß1 signaling pathway.

OBJECTIVE: To investigate the tumor inhibition effect of Yangfei Kongliu Formula (YKF), a compound Chinese herbal medicine, combined with cisplatin (DDP) and its action mechanisms. METHODS: C57BL/6 mice with Lewis lung carcinoma were divided into six groups: control group (C), DDP group (2 mg/kg, DDP), low-dose YKF group (2.43 g/kg, L), high-dose YKF group (24.3 g/kg, H), low-dose YKF combined with DDP group (L + DDP) and high-dose YKF combined with DDP group (H + DDP). Transforming growth factor-ß1 (TGF-ß1), mothers against decapentaplegic homolog 3 (Smad3) and Smad7 levels were measured with quantitative real-time polymerase chain reaction (qPCR), Western blotting and immunohistochemistry. An enzyme-linked immunosorbent assay was used to analyze the expressions of interleukin-2 (IL-2) and tumor necrosis factor-α (TNF-α). RESULTS: YKF combined with DDP significantly inhibited the growth and metastasis of tumors relative to the control group, and YKF groups (P < 0.05). There was no significant difference between high-dose YKF group and low-dose YKF group (P > 0.05). We also found that the expression levels of TGF-ß1 and Smad3 were both significantly decreased by YKF relative to the control group (P < 0.05). Furthermore, after treatment with YKF combined with DDP, the expression levels of TGF-ß1 and Smad3 were decreased but the expression level of Smad7 was increased relative to the DDP group (P < 0.05). Compared to the DDP group, the combination of YKF and DDP enhanced the effect of tumor inhibition (P < 0.05), showing obvious synergy between YKF and DDP. Treatment with DDP or YKF decreased serum levels of IL-2 and TNF-α relative to the control group (P < 0.05). Furthermore, the expression levels of IL-2 and TNF-α were significantly decreased when treated with YKF in combination with DDP. Co-treatment with YKF and DDP significantly inhibited tumor growth, decreased the expressions of TGF-ß1, Smad3, IL-2 and TNF-α and increased the expression of Smad7; these differences were significant relative to both YKF groups and the control group (P < 0.05). CONCLUSION: YKF can inhibit tumor growth synergistically with DDP, mainly through the TGF-ß1 signaling pathway.