Effects Of Endothelin-1 On Intracellular Tetrahydrobiopterin Levels In Vascular Tissue

Samchulkunbi-Tang Alleviates Vascular Endothelial Disorder and Renal Dysfunction in Nitric Oxide-Deficient Hypertensive Rats

Samchulkunbi-tang (SCT, Shen Zhu Jian pi tang in Chinese) is said to have been first recorded by Zheng Zhi Zhun Sheng during the Ming Dynasty in China. Records of SCT in Korea are known to have been cited in Donguibogam (Dong Yi Bao Jian in Chinese), Uibang Hwaltu (Yi Fang Huo Tao in Chinese), and Bang Yak Hapyeon (Fang Yao He Bian in China). Although SCT is widely used in treating chronic gastritis and gastric ulcers, the beneficial effect on renal vascular function is unknown. Hypertension is a risk factor for cardiovascular disease and endothelial dysfunction in humans and experimental animal models of arterial hypertension. In addition, kidney dysfunction is characterized by hypertension diseases. This study was conducted to evaluate the effect of SCT on the vascular function in vitro (human umbilical cord endothelial cells, HUVECs) and in vivo (N^G‐nitro‐L‐arginine methyl ester, L-NAME-induced hypertensive rats). The phosphorylation of protein kinase B (Akt) and endothelial nitric oxide synthase (eNOS) is closely related to nitric oxide (NO) production in HUVECs, and SCT in this study significantly increased these. For three weeks, hypertensive rat models were induced by L-NAME administration (40 mg/kg/day) with portable water. It was followed by oral administration with 100 and 200 mg/kg/day for two weeks to confirm the effectiveness of SCT. As a result, systolic blood pressure decreased in the SCT-treated groups, compared with that in the L-NAME-induced hypertensive group. SCT treatment restored vasorelaxation by stimulating acetylcholine and cGMP production in the thoracic aorta. In addition, SCT treatment decreased intima-media thickness, attenuated the reduction of eNOS expression, and increased endothelin-1 expression. It also increased p-Akt and p-eNOS expression in hypertensive rat aorta. Furthermore, regarding renal function parameters, SCT ameliorated urine osmolality, urine albumin level, serum creatinine, and blood urea nitrogen levels. These results demonstrate that the oriental medicine SCT exerts potent vascular and renal protective effects on nitric oxide-deficient hypertensive rats and HUVECs

ET-1 regulates the human umbilical vein endothelial cell cycle by adjusting the ERβ/FOXN1 signaling pathway

Background

Atherosclerosis (AS) is a chronic and progressive disease primarily induced by inflammation of the arterial blood vessel wall. Investigating the function and molecular regulation mechanisms of ET-1, ERβ, and FOXN1 in disease models will provide new targets and means for clinical treatment.

Methods

The effects of ET-1 on oxidative stress in HUVEC were verified through quantitative polymerase chain reaction (qPCR), western blot, flow cytometry, as well as dual luciferase reporter gene and biochemical assays.

Results

Compared with the ET-1+ negative control (NC) group, the ERβ messenger ribonucleic acid (mRNA) expression level was significantly reduced, and the FOXN1 mRNA expression level increased markedly in the ET-1 + ERβ small interfering ribonucleic acid (siRNA) group. Meanwhile, the FOXN1 mRNA expression level was significantly reduced in the ET-1 + FOXN1 siRNA group. FOXN1 promoter luciferase reporter gene activity was notably enhanced in the ERβ siRNA group compared with the siRNA control group. Compared with the ET-1 + NC group, the levels of reaction oxygen species (ROS) in the ET-1 + ERβ siRNA group increased considerably, the superoxide dismutase (SOD) level was significantly reduced, and the G0/G1 phase cell ratio was reduced. In addition, the protein expression of ERβ and cyclin B1 (CCNB1) was markedly reduced, whereas the protein expression of cyclin A2 (CCNA2), cyclin D1 (CCND1), and cyclin E1 (CCNE1) increased substantially. The opposite result was observed in the ET-1 + FOXN1 siRNA group.

Conclusions

ET-1 can contribute to the expression of ERβ and FOXN1. ERβ can inhibit the expression of FOXN1 by regulating promoter activity. The ET-1/ERβ/FOXN1 signaling pathway is involved in the regulation of oxidative stress and cycle progression in HUVEC. This study provides a new mechanism for the regulation of umbilical vein endothelial cells. The ET-1/ERβ/FOXN1 signaling pathway may provide novel therapeutic targets and strategies for the treatment of atherosclerosis.

Molecular mechanism involved in cyclophosphamide-induced cardiotoxicity: Old drug with a new vision

Cyclophosphamide (CP) is an important anticancer drug which belongs to the class of alkylating agent. Cyclophosphamide is mostly used in bone marrow transplantation, rheumatoid arthritis, lupus erythematosus, multiple sclerosis, neuroblastoma and other types of cancer. Dose-related cardiotoxicity is a limiting factor for its use. CP-induced cardiotoxicity ranges from 7 to 28% and mortality ranges from 11 to 43% at the therapeutic dose of 170-180 mg/kg, i.v. CP undergoes hepatic metabolism that results in the production of aldophosphamide. Aldophosphamide decomposes into phosphoramide mustard & acrolein. Phosphoramide is an active neoplastic agent, and acrolein is a toxic metabolite which acts on the myocardium and endothelial cells. This is the first review article that talks about cyclophosphamide-induced cardiotoxicity and the different signaling pathways involved in its pathogenicity. Based on the available literature, CP is accountable for cardiomyocytes energy pool alteration by affecting the heart fatty acid binding proteins (H-FABP). CP has been found associated with cardiomyocytes apoptosis, inflammation, endothelial dysfunction, calcium dysregulation, endoplasmic reticulum damage, and mitochondrial damage. Molecular mechanism of cardiotoxicity has been discussed in detail through crosstalk of Nrf2/ARE, Akt/GSK-3β/NFAT/calcineurin, p53/p38MAPK, NF-kB/TLR-4, and Phospholamban/SERCA-2a signaling pathway. Based on the available literature we support the fact that metabolites of CP are responsible for cardiotoxicity due to depletion of antioxidants/ATP level, altered contractility, damaged endothelium and enhanced pro-inflammatory/pro-apoptotic activities resulting into cardiomyopathy, myocardial infarction, and heart failure. Dose adjustment, elimination/excretion of acrolein and maintenance of endogenous antioxidant pool could be the therapeutic approach to mitigate the toxicities.