Trichloroethylene induces immune renal tubular injury through SIRT 1/HSP 70/TLR 4 pathway in BALBc mice

Trichloroethylene (TCE) is a volatile chlorinated solvent widely used for cleaning and degreasing industrial metal parts. Due to the widespread use and improper disposal of TCE, exposure to TCE causes a variety of adverse effects on human and animal health. However, the underlying mechanism of the damage remains unclear. The purpose of this study is to investigate the role of Sirtuin-1 (SIRT 1) in TCE-induced immune renal tubular injury. 6-8-week-old female BALB/c mice were used to construct a TCE sensitized mouse model. SIRT 1 activator, SRT 1720 (0.1 ml, 5 mg/kg) and toll like receptor 4 (TLR 4) inhibitor, TAK-242 (0.1 ml, 3 mg/kg) were used for treatment. Results show that SIRT 1 and heat shock protein 70 (HSP 70) levels are significantly down-regulated in renal tubules, serum and urine HSP 70 levels are significantly increased, and inflammatory cytokines levels are significantly increased in renal tubules in TCE-sensitized positive mice. After SRT 1720 treatment, intracellular HSP 70 level is significantly increased and extracellular HSP 70 level is decreased, and inflammatory cytokines levels get alleviated. In addition, HSP 70 and Toll-like Receptor 4 (TLR 4) proteins exist an interaction that can be significantly attenuated by SIRT 1. Subsequently, inflammation of the renal tubules mediated by SIRT 1 downregulation is attenuated after TAK-242 treatment. In conclusion, SIRT 1 alleviates renal tubular epithelial cells immune injury by inhibiting the release of HSP 70 and thereby weakening interaction with HSP 70 and TLR 4.

Mitoquinone intravitreal injection ameliorates retinal ischemia-reperfusion injury in rats involving SIRT1/Notch1/NADPH axis

Retinal ischemia-reperfusion injury (RIRI) is an important pathological process of many ocular diseases. Mitoquinone (MitoQ), a mitochondrial targeted antioxidant, is a potential compound for therapeutic development of RIRI. This study observed the effect of MitoQ on RIRI, and further explored its possible molecular mechanism. Temporary increase in intraocular pressure was used to establish rat model of RIRI to observe the effect of MitoQ treatment on retinal function, pathological injury, oxidative stress, inflammation and apoptosis. Immunohistochemistry and Western blot were used to detect expressions of cleaved caspase 3, B cell leukemia/lymphoma 2 associated X (Bax), nicotinamide adenine dinucleotide phosphate oxidase (NOX1), NOX4, cleaved-Notch 1, hairy and enhancer of split 1 (Hes1), and sirtuin 1 (SIRT 1) in retina were detected by immunohistochemistry and Western blot. MitoQ treatment significantly improved retinal function and pathological injury, inhibited the over-production of reactive oxygen species, increased the expression of superoxide dismutase 1 (SOD 1), suppressed the releases of inflammatory cytokines, and inhibited retinal cells apoptosis. MitoQ also down-regulated the expressions of cleaved caspase 3, Bax, NOX 1, NOX 4, cleaved-Notch 1, and Hes 1, increased the expression of SIRT 1 protein and its activity. These effects were significantly reversed by SIRT1 inhibitor EX527. Our data suggests that MitoQ, as a potentially effective drug for improving RIRI, may act through the SIRT1/Notch1/NADPH signal axis.

Electroacupuncture Alleviates Cerebral Ischemia/Reperfusion Injury in Rats by Histone H4 Lysine 16 Acetylation-Mediated Autophagy

Background: Electroacupuncture (EA) treatment in ischemic stroke has been highlighted recently; however, the specific mechanism is still elusive. Autophagy is considered a new target for cerebral ischemia/reperfusion (I/R), but whether it plays a role of protecting or causing rapid cell apoptosis remains unclear. Studies have reported that the reduction in lysine 16 of histone H4 acetylation coheres with autophagy induction. The primary purpose of the study was to explore whether EA could alleviate I/R via autophagy-mediated histone H4 lysine 16 acetylation in the middle cerebral artery occlusion (MCAO) rat model. Methods: One hundred and twenty male Sprague-Dawley rats were divided into five groups: control group, MCAO group, MCAO+EA group, MCAO+EA+hMOF siRNA group, and MCAO+EA+Sirt1 inhibitor group. EA was applied to "Baihui" (Du20) and "Renzhong" (Du26) at 5 min after modeling and 16 h after the first EA intervention. The structure and molecular markers of the rat brain were evaluated. Results: EA significantly alleviated I/R injury by upregulating the expressions of Sirt1, Beclin1, and LC3-II and downregulating the expressions of hMOF and H4K16ac. In contrast, the Sirt1 inhibitor lowered the increase in Sirt1, Beclin1, and LC3-II and enhanced the level of hMOF and H4K16ac expressions associated with EA treatment. Besides, ChIP assay revealed that the binding of H4K16ac in the Beclin1 promoter region of the autophagy target gene was significantly raised in the MCAO+EA group and MCAO+EA+hMOF siRNA group. Conclusions: EA treatment inhibited the H4K16ac process, facilitated autophagy, and alleviated I/R injury. These findings suggested that regulating histone H4 lysine 16 acetylation-mediated autophagy may be a key mechanism of EA at Du20 and Du26 to treat I/R.