Although the innate immune response to induce postischemic inflammation is considered as an essential step in the progression of cerebral ischemia injury, the role of innate immunity mediator NLRP3 in the pathogenesis of ischemic stroke is unknown. In this study, focal ischemia was induced by middle cerebral artery occlusion in NLRP3(-/-), NOX2(-/-), or wild-type (WT) mice. By magnetic resonance imaging (MRI), Evans blue permeability, and electron microscopic analyses, we found that NLRP3 deficiency ameliorated cerebral injury in mice after ischemic stroke by reducing infarcts and blood-brain barrier (BBB) damage. We further showed that the contribution of NLRP3 to neurovascular damage was associated with an autocrine/paracrine pattern of NLRP3-mediated interleukin-1β (IL-1β) release as evidenced by increased brain microvessel endothelial cell permeability and microglia-mediated neurotoxicity. Finally, we found that NOX2 deficiency improved outcomes after ischemic stroke by mediating NLRP3 signaling. This study for the first time shows the contribution of NLRP3 to neurovascular damage and provides direct evidence that NLRP3 as an important target molecule links NOX2-mediated oxidative stress to neurovascular damage in ischemic stroke. Pharmacological targeting of NLRP3-mediated inflammatory response at multiple levels may help design a new approach to develop therapeutic strategies for prevention of deterioration of cerebral function and for the treatment of stroke.

Studies have highlighted the importance of histone deacetylase (HDAC)-mediated epigenetic processes in the development of diabetic complications. Inhibitors of HDAC are a novel class of therapeutic agents in diabetic nephropathy, but currently available inhibitors are mostly nonselective inhibit multiple HDACs, and different HDACs serve very distinct functions. Therefore, it is essential to determine the role of individual HDACs in diabetic nephropathy and develop HDAC inhibitors with improved specificity. First, we identified the expression patterns of HDACs and found that, among zinc-dependent HDACs, HDAC2/4/5 were upregulated in the kidney from streptozotocin-induced diabetic rats, diabetic db/db mice, and in kidney biopsies from diabetic patients. Podocytes treated with high glucose, advanced glycation end products, or transforming growth factor-β (common detrimental factors in diabetic nephropathy) selectively increased HDAC4 expression. The role of HDAC4 was evaluated by in vivo gene silencing by intrarenal lentiviral gene delivery and found to reduce renal injury in diabetic rats. Podocyte injury was associated with suppressing autophagy and exacerbating inflammation by HDAC4-STAT1 signaling in vitro. Thus, HDAC4 contributes to podocyte injury and is one of critical components of a signal transduction pathway that links renal injury to autophagy in diabetic nephropathy.

An increasing number of clinical and animal model studies indicate that activation of the innate immune system and inflammatory mechanisms are important in the pathogenesis of diabetic nephropathy. Nucleotide-binding oligomerization domain containing 2 (NOD2), a member of the NOD-like receptor family, plays an important role in innate immune response. Here we explore the contribution of NOD2 to the pathogenesis of diabetic nephropathy and found that it was upregulated in kidney biopsies from diabetic patients and high-fat diet/streptozotocin-induced diabetic mice. Further, NOD2 deficiency ameliorated renal injury in diabetic mice. In vitro, NOD2 induced proinflammatory response and impaired insulin signaling and insulin-induced glucose uptake in podocytes. Moreover, podocytes treated with high glucose, advanced glycation end-products, tumor necrosis factor-α, or transforming growth factor-β (common detrimental factors in diabetic nephropathy) significantly increased NOD2 expression. NOD2 knockout diabetic mice were protected from the hyperglycemia-induced reduction in nephrin expression. Further, knockdown of NOD2 expression attenuated high glucose-induced nephrin downregulation in vitro, supporting an essential role of NOD2 in mediating hyperglycemia-induced podocyte dysfunction. Thus, NOD2 is one of the critical components of a signal transduction pathway that links renal injury to inflammation and podocyte insulin resistance in diabetic nephropathy.

SignificanceLiver steatosis, or fatty liver, is the most common liver disease in the world, affecting up to 25% of all Americans. There is currently no approved drug available for this condition, which may progress to serious disease, including steatohepatitis, fibrosis, and cirrhosis. Here, we show in rodent and human models of metabolic syndrome that steatosis can be prevented by a simple dietary approach. Inorganic nitrate, present in green leafy vegetables, is converted in vivo to nitric oxide (NO) in a process involving symbiotic host bacteria. NO then induces key metabolic regulatory pathways to ultimately reduce oxidative stress and improve cardiometabolic functions. Clinical trials would be helpful to tell if dietary nitrate is useful in treatment and prevention of fatty liver disease.

Background The triglyceride-glucose (TyG) index is an alternative marker of insulin resistance (IR) and is closely associated with the prevalence and prognosis of atherosclerotic cardiovascular disease (ASCVD). However, the association between the TyG index and in-stent restenosis (ISR) after drug-eluting stent (DES) implantation in patients with acute coronary syndrome (ACS) remains unknown. Methods The present study retrospectively recruited patients who were admitted for ACS and underwent coronary angiography at 6 to 24 months after successful DES-based percutaneous coronary intervention (PCI). In addition, we calculated the TyG index with the following formula: Ln(fasting triglyceride [mg/dL] × fasting blood glucose [mg/dL]/2) and divided patients into 3 groups according to the tertile of the TyG index. Most importantly, multivariate logistic regression analysis models were also constructed to assess the association between the TyG index and DES-ISR in patients with ACS. Results A total of 1574 patients with ACS (58.4 ± 9.4 years, 77.4% male) were included in this study. At the median follow-up time of 12 (9–14) months, the prevalence of DES-ISR increased stepwise with the increasing tertile of the TyG index (11.6% vs 17.3% vs 19.4%, p = 0.002), and the TyG index was also higher in the ISR group than in the non-ISR group (9.00 ± 0.58 vs 8.84 ± 0.61, p < 0.001). In addition, the positive association between the TyG index and the prevalence of DES-ISR was also determined in the fully adjusted model (TyG, per 1-unit increase: OR 1.424, 95% CI 1.116 to 1.818, p = 0.005; tertile of TyG, the OR (95% CI) values for tertile 2 and tertile 3 were 1.454 (1.013 to 2.087) and 1.634 (1.125 to 2.374), respectively, with tertile 1 as a reference). The association was also reflected in most subgroups. Moreover, adding the TyG index to the predictive model for DES-ISR in patients with ACS could contribute to an increase in C-statistics (0.675 vs 0.659, p = 0.010), categorical net reclassification improvement (0.090, p < 0.001), and integrated discrimination improvement (0.004, p = 0.040). Conclusion An elevated TyG index was independently and positively associated with DES-ISR in patients with ACS who underwent PCI. However, the incremental predictive value of the TyG index for DES-ISR was slight. To further confirm our findings, future studies are needed.