ABSTRACT
Sepsis-induced myocardial dysfunction (SIMD) has become one of the most lethal complications of sepsis, while the treatment was limited by a shortage of pertinent drugs. Epigallocatechin-3-gallate (EGCG) is the highest content of active substances in green tea, and its application in cardiovascular diseases has broad prospects. This study was conducted to test the hypothesis that EGCG was able to inhibit lipopolysaccharide (LPS) induced myocardial dysfunction and investigate the underlying molecular mechanisms. The cardiac systolic function was assessed by echocardiography. The cardiomyocyte apoptosis was determined by TUNEL staining. The expression of inflammatory factors and apoptosis-related protein, cardiac markers were examined by Western Blot and qRT-PCR. EGCG effectively improve LPS-induced cardiac function damage, enhance left ventricular systolic function, and restore myocardial cell vitality. It can effectively inhibit the upregulation of TLR4 expression induced by LPS and inhibit IκB α/NF- κB/p65 signaling pathway, thereby inhibiting cardiomyocyte apoptosis and improving myocarditis. In conclusion, EGCG protects against SIMD through anti-inflammatory and anti-apoptosis effects; it was mediated by the inhibition of the TLR4/NF-κB signal pathway. Our results demonstrated that EGCG might be a possible medicine for SIMD prevention and treatment.
ABSTRACT
Diabetic macular edema, resulting from increased microvascular permeability, is the most prevalent cause of vision loss in diabetes. The mechanisms underlying this complication remain poorly understood. In the current study, diabetic vascular permeability (blood-retinal barrier breakdown) is demonstrated to result from a leukocyte-mediated Fas-FasL-dependent apoptosis of the retinal vasculature. Following the onset of streptozotocin-induced diabetes, FasL expression was increased in rat neutrophils (P<0.005) and was accompanied by a simultaneous increase in Fas expression in the retinal vasculature. Static adhesion assays demonstrated that neutrophils from diabetic, but not control, rats induced endothelial cell apoptosis in vitro (P<0.005). The latter was inhibited via an antibody-based FasL blockade (P<0.005). In vivo, the inhibition of FasL potently reduced retinal vascular endothelial cell injury, apoptosis, and blood-retinal barrier breakdown (P<0.0001) but did not diminish leukocyte adhesion to the diabetic retinal vasculature. Taken together, these data are the first to identify leukocyte-mediated Fas-FasL-dependent retinal endothelial cell apoptosis as a major cause of blood-retinal barrier breakdown in early diabetes. These data imply that the targeting of the Fas-FasL pathway may prove beneficial in the treatment of diabetic retinopathy.
