Hyperbilirubinemia Induces Pro-Apoptotic Effects and Aggravates Renal Ischemia Reperfusion Injury.

AIMS: Hyperbilirubinemia is associated with postoperative acute kidney injury in patients undergoing cardiac surgeries. A high concentration of bilirubin could induce oxidative stress and cell apoptosis. The aim of this study was to investigate whether hyperbilirubinemia aggravated the renal tubule cells injury and the pro-apoptotic potential of bilirubin on renal ischemia reperfusion injury (RIRI). METHODS: The human proximal tubular epithelial cell line HK-2 cells were challenged with a gradient concentration of bilirubin for 24 h. Cell injury was assessed by flow cytometry and MTT assay. Bilirubin was injected intraperitoneally into male Sprague-Dawley rats once every 12 h (100 mg/kg), 3 times in total. The same solvent volume without bilirubin powder was used as vehicle in non-bilirubin injection groups. The RIRI surgical procedure was a bilateral renal pedicles clamping (45 min) followed by 30 h reperfusion. The rats were divided into 4 groups: negative control (NC), similar surgical procedures without clamping; Bil, bilirubin injection for 36 h, then rats were sacrificed; RIRI, RIRI surgical procedures; Bil + RIRI, RIRI applied 6 h later than the first bilirubin injection, rats were sacrificed after another 30 h. RESULTS: In vitro, bilirubin induced cell apoptosis and significantly decreased the cell viability of HK-2 cells. Bilirubin induced the active caspase 3 and phosphorylation of p38 in HK-2 cells. In vivo, serum creatinine was higher in Bil + RIRI compared with RIRI (p < 0.01). The tubular injury scores of hematoxylin and eosin and tubular necrosis scores of periodic acid-Schiff were higher in Bil + RIRI than these in RIRI (All p < 0.05). The number of Tunel-positive nuclei was higher in Bil + RIRI compared to RIRI (p < 0.001). The active caspase 3 and phosphorylation of p38 were higher and the Bcl2 was lower in Bil + RIRI compared to RIRI. Moreover, the apoptosis level was higher in Bil compared to NC. CONCLUSIONS: Our results reveal that the hyperbilirubinemia induces pro-apoptotic effects and aggravates RIRI.

Correlation between Histone Deacetylase 9 and Regulatory T Cell in Patients with Chronic Heart Failure.

Heart failure (HF) is the end stage of various kinds of cardiovascular diseases and leads to a high mortality worldwide. Numerous studies have demonstrated that frequencies of CD4+CD25+Foxp3+ regulatory T cells (Tregs) are reduced in HF patients and properly expanding Tregs attenuates HF progression. Histone deacetylase (HDAC) 9 has been revealed to contribute to several cardiovascular and cerebrovascular diseases. Plenty of studies showed that HDAC9 negatively regulated the number and function of Tregs. Thus, we aim to investigate the expression of HDAC 9 in patients with chronic heart failure (CHF) and the relationship among HDAC9, Tregs and CHF. Our research showed a reduced number of Tregs and an increased expression of HDAC9 mRNA in CHF patients. Patients with CHF were divided into two groups by heart function grade of New York Heart Association (NYHA), we found that the HDAC9 mRNA expression level in NYHA grade II-III group were lower than that in NYHA grade IV group. More importantly, the correlation study suggested that the expression of HDAC9 mRNA was negatively correlated to Tregs frequency and left ventricular ejection fraction (LVEF), whereas positively correlated to larger left ventricular end-diastolic dimension (LVEDD) and B-type natriuretic peptide (BNP) in patients with CHF. The correlation studies also showed a positive correlation between HDAC9 and the severity of CHF. Our research suggests that HDAC9 may be a new indicator for assessing CHF and it may offer a new direction for research of CHF.

Baicalin and geniposide inhibit the development of atherosclerosis by increasing Wnt1 and inhibiting dickkopf-related protein-1 expression.

BACKGROUND: Our previous study showed that the combined Chinese herbs containing scutellaria baicalensis georgi and gardenia jasminoids ellis inhibited atherosclerosis. In this study, we sought to determine if baicalin and geniposide could inhibit atherosclerosis through Wnt1 and dickkopf-related protein-1 (DKK1). METHODS: The wild-type and ApoE-/- mice were treated with baicalin, geniposide, and baicalin plus geniposide daily by gavage for 12 weeks. Blood lipid levels were measured with an automatic biochemistry analyzer. Aortic atherosclerotic lesion areas were analyzed with Image-ProPlus software. The mRNA and protein expression of DKK1, Wnt1 and nuclear factor-κB (NF-κB) were measured with RT-PCR and Western Blot. Serum levels of interleukin-12 (IL-12) were quantified with ELISA. RESULTS: The baicalin or geniposide monotherapy as well as combination therapy inhibited the development of atherosclerotic lesions, increased Wnt1 and decreased DKK1 expression and elevated the ratio of Wnt1/DKK1 compared with high-lipid diet group. However, only baicalin or geniposide monotherapy decreased NF-κB expression. Moreover, baicalin and geniposide mono- or combination therapy lowered IL-12 levels. Geniposide reduced both serum total cholesterol and low density lipoprotein levels, while baicalin either alone or in combination with geniposide did not affect serum lipid levels. In human, umbilical vein endothelial cells stimulated by oxidized low density lipoprotein, baicalin and geniposide also increased Wnt1 and decreased DKK1 expression and elevated the ratio of Wnt1/DKK1. CONCLUSIONS: Baicalin and geniposide exert inflammation-regulatory effects and may prevent atherosclerotic lesions through enhancing Wnt1 and inhibiting DKK1 expression.