Macrophage Dectin-1 mediates Ang II renal injury through neutrophil migration and TGF-ß1 secretion.

Macrophage activation has been shown to play an essential role in renal fibrosis and dysfunction in hypertensive chronic kidney disease. Dectin-1 is a pattern recognition receptor that is also involved in chronic noninfectious diseases through immune activation. However, the role of Dectin-1 in Ang II-induced renal failure is still unknown. In this study, we found that Dectin-1 expression on CD68 + macrophages was significantly elevated in the kidney after Ang II infusion. We assessed the effect of Dectin-1 on hypertensive renal injury using Dectin-1-deficient mice infused by Angiotensin II (Ang II) at 1000 ng/kg/min for 4 weeks. Ang II-induced renal dysfunction, interstitial fibrosis, and immune activation were significantly attenuated in Dectin-1-deficient mice. A Dectin-1 neutralizing antibody and Syk inhibitor (R406) were used to examine the effect and mechanism of Dectin-1/Syk signaling axle on cytokine secretion and renal fibrosis in culturing cells. Blocking Dectin-1 or inhibiting Syk significantly reduced the expression and secretion of chemokines in RAW264.7 macrophages. The in vitro data showed that the increase in TGF-ß1 in macrophages enhanced the binding of P65 and its target promotor via the Ang II-induced Dectin-1/Syk pathway. Secreted TGF-ß1 caused renal fibrosis in kidney cells through Smad3 activation. Thus, macrophage Dectin-1 may be involved in the activation of neutrophil migration and TGF-ß1 secretion, thereby promoting kidney fibrosis and dysfunction.

Schisandrin C targets Keap1 and attenuates oxidative stress by activating Nrf2 pathway in Ang II-challenged vascular endothelium.

Vascular endothelial dysfunction plays a crucial role in the pathogenesis of cardiovascular diseases. Oxidative stress is a key pathophysiological mechanism underpinning endothelial dysfunction. Schisandrin C (Sch C), a dibenzocyclooctadiene derivative of Schisandra chinensis, has antioxidative properties. Here, we report the use of Sch C as a novel therapeutic for the treatment of angiotensin II (Ang II)-induced endothelial deficits and explore the underlying mechanisms and the target of Sch C. Our results demonstrated that Sch C treatment prevents aorta oxidative stress and improves relaxation in mice, challenged with subcutaneous infusion of Ang II. In addition, Sch C significantly ameliorates Ang II-induced oxidative stress in rat aortic endothelial cells. We then discovered that these antioxidative effects of Sch C are mediated through the induction of nuclear factor (erythroid-derived 2)-like 2 (Nrf2). Using an expression plasmid and molecular docking, we identified that Kelch-like ECH-associated protein-1 (Keap1), a negative regulator of Nrf2, is a target of Sch C. These findings provide evidence for the potential use of Sch C as an antioxidative agent for treatment of vascular endothelial deficits.

miRNA­92a inhibits vascular smooth muscle cell phenotypic modulation and may help prevent in­stent restenosis.

The modulation of vascular smooth muscle cell (VSMC) phenotype during cellular proliferation and migration may represent a potential therapeutic approach for vascular intimal hyperplasia prevention. However, the precise role of this process in VSMC biology and remodeling remains unclear. In the present study, western blotting, PCR, MTT and Transwell assays were used to analyze related protein and mRNA expression, cell viability and cell migration, respectively. It was demonstrated that miR­92a modulated VSMCs into a synthetic phenotype via the Kruppel­like factor 4 (KLF4) pathway. Targeting microRNA (miRNA/miR)­92a in VSMCs using a KLF4 inhibitor suppressed the synthetic phenotype and inhibited VSMC proliferation and migration. To further confirm this finding, the expression levels of miR­92a were measured in patients undergoing coronary artery intervention. The serum miR­92a expression levels were significantly higher in patients with in­stent restenosis (ISR) compared with those in patients without ISR, whereas KLF4 expression was significantly reduced in the non­ISR group. Bioinformatic analysis and promoter­luciferase reporter assays were used to examine the regulatory mechanisms underlying KLF4 expression. KLF4 was demonstrated to be transcriptionally upregulated by miR­92a in VSMCs. miRNA transfection was also performed to regulate the level of miR­92a expression. miR­92a overexpression inhibited VSMC proliferation and migration, and also increased the mRNA and protein expression levels of certain differentiated VSMC­related genes. Finally, miR­92a inhibition promoted the proliferation and migration of VSMCs, which could be reversed using a KLF4 inhibitor. Collectively, these results indicated that the local delivery of a KLF4 inhibitor may act as a novel therapeutic option for the prevention of ISR.

DL-3-n-Butylphthalide Attenuates Myocardial Hypertrophy by Targeting Gasdermin D and Inhibiting Gasdermin D Mediated Inflammation.

Pressure overload leads to a hypertrophic milieu that produces deleterious cardiac dysfunction. Inflammation is a key pathophysiological mechanism underpinning myocardial hypertrophy. DL-3-n-butylphthalide (NBP), a neuroprotective agent, also has potent cardioprotective effects. In this study, the potential of NBP to antagonize myocardial hypertrophy was evaluated in C57BL/6 mice in vivo and in rat primary cardiomyocytes in vitro. In mice, NBP treatment reduced cardiac hypertrophy and dysfunction in a transverse aortic constriction (TAC)-induced pressure overload model. In angiotensin (Ang) II-challenged cardiomyocytes, NBP prevents cell size increases and inhibits gasdermin D (GSDMD)-mediated inflammation. Furthermore, overexpression of GSDMD-N reduced the protective effects of NBP against Ang II-induced changes. Using molecular docking and MD simulation, we found that the GSDMD-N protein may be a target of NBP. Our study shows that NBP attenuates myocardial hypertrophy by targeting GSDMD and inhibiting GSDMD-mediated inflammation.

Schisandrin B protects against angiotensin II-induced endotheliocyte deficits by targeting Keap1 and activating Nrf2 pathway.

INTRODUCTION: Schisandrin B (SchB), the main active constituent in Schisandra chinensis, has antioxidant activities. Endothelial dysfunction leads to various cardiovascular diseases. Oxidative stress is a crucial pathophysiological mechanism underpinning endothelial dysfunction. METHODS: We elucidated the role and underlying mechanisms of SchB in angiotensin II-induced rat aortic endothelial-cell deficits and explored targets of SchB through siRNA analysis and molecular docking. We measured apoptosis by TUNEL and oxidative stress by dihydroethidium (DHE) and 2',7' -dichlorofluorescin diacetate (DCF) staining. RESULTS: Our results demonstrated that SchB significantly ameliorated oxidative stress, mitochondrial membrane-potential depolarization and apoptosis in angiotensin II-challenged rat aortic endothelial cells. We further discovered that these antioxidative effects of SchB were mediated through induction of Nrf2. Importantly, using molecular docking and molecular dynamic simulation, we identified that Keap1, an adaptor for the degradation of Nrf2, was a target of SchB. CONCLUSION: These findings support the potential use of SchB as a Keap1 inhibitor for attenuating oxidative stress, and Keap1 might serve as a therapeutic target in the treatment of cardiovascular diseases.