AMPK activation by metformin protects against pulmonary hypertension in rats and relaxes isolated human pulmonary artery

Resveratrol attenuates cyclosporin A-induced upregulation of the thromboxane A2 receptor and hypertension via the AMPK/SIRT1 and MAPK/NF-κB pathways in the rat mesenteric artery

Cyclosporin A, an immunosuppressive agent, is extensively utilized for the prevention of transplant rejection and treat autoimmune disease in the clinic, despite its association with a high risk of hypertension development among patients. Resveratrol is a kind of non-flavonoid phenolic compound that widely exists in many plants. The aim of the present study was to investigate the mechanism by which resveratrol ameliorates cyclosporin A-induced hypertension. The arterial rings of the mesentery were incubated with cyclosporin A and resveratrol in vitro. Rats were administered cyclosporin A and/or resveratrol for 3 weeks in vivo. Blood pressure was measured via the tail arteries. Vasoconstriction curves were recorded using a sensitive myograph. The protein expression was evaluated through Western blotting. This study demonstrated that resveratrol mitigated the cyclosporin A-induced increase in blood pressure in rats. Furthermore, resveratrol markedly inhibited the cyclosporin A-induced upregulation of thromboxane A2 receptor-mediated vasoconstriction in the rat mesenteric artery both in vitro and in vivo. Moreover, resveratrol activated AMPK/SIRT1 and inhibited the MAPK/NF-κB signaling pathway. In conclusion, resveratrol restored the cyclosporin A-induced upregulation of the thromboxane A2 receptor and hypertension via the AMPK/SIRT1 and MAPK/NF-κB pathways in rats.

Canagliflozin inhibits PASMCs proliferation via regulating SGLT1/AMPK signaling and attenuates artery remodeling in MCT-induced pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) was a devastating disease characterized by artery remodeling, ultimately resulting in right heart failure. The aim of this study was to investigate the effects of canagliflozin (CANA), a sodium-glucose cotransporter 2 inhibitor (SGLT2i) with mild SGLT1 inhibitory effects, on rats with PAH, as well as its direct impact on pulmonary arterial smooth muscle cells (PASMCs). PAH rats were induced by injection of monocrotaline (MCT) (40 mg/kg), followed by four weeks of treatment with CANA (30 mg/kg/day) or saline alone. Pulmonary artery and right ventricular (RV) remodeling and dysfunction in PAH were alleviated with CANA, as assessed by echocardiography. Hemodynamic parameters and structural of pulmonary arteriole, including vascular wall thickness and wall area, were reduced by CANA. RV hypertrophy index, cardiomyocyte hypertrophy, and fibrosis were decreased with CANA treatment. PASMCs proliferation was inhibited by CANA under stimulation by platelet-derived growth factor (PDGF)-BB or hypoxia. Activation of AMP kinase (AMPK) was induced by CANA treatment in cultured PASMCs in a time- and concentration-dependent manner. These effects of CANA were attenuated when treatment with compound C, an AMPK inhibitor. Abundant expression of SGLT1 was observed in PASMCs and pulmonary arteries, while SGLT2 expression was undetectable. SGLT1 increased in response to PDGF-BB or hypoxia stimulation, while PASMCs proliferation was inhibited and beneficial effects of CANA were counteracted by knockdown of SGLT1. Our research demonstrated for the first time that CANA inhibited the proliferation of PASMCs by regulating SGLT1/AMPK signaling and thus exerted an anti-proliferative effect on MCT-induced PAH.

Current Management and Future Directions for Pulmonary Arterial Hypertension Associated with Congenital Heart Disease

Current management of patients with congenital heart disease has increased their survival into adulthood. This is accompanied by potential cardiac complications, including pulmonary hypertension associated with congenital heart disease (PAH-CHD). PAH-CHD constitutes a challenging subgroup of pulmonary hypertension and requires expert management to improve quality of life and prognosis. Novel agents have shown a significant improvement in morbidity and mortality in patients with pulmonary arterial hypertension. However, the long-term effects of these medications on PAH-CHD patients remain somewhat uncertain, necessitating treatment plans largely founded on the clinical experience of the healthcare providers. The aim of this review is to summarize the current evidence and future perspectives regarding treatment strategies for PAH-CHD to help better guide management of this complex disease.

Maternal exercise represses Nox4 via SIRT1 to prevent vascular oxidative stress and endothelial dysfunction in SHR offspring

Maternal exercise during pregnancy has emerged as a potentially promising approach to protect offspring from cardiovascular disease, including hypertension. Although endothelial dysfunction is involved in the pathophysiology of hypertension, limited studies have characterized how maternal exercise influences endothelial function of hypertensive offspring. In this study, pregnant spontaneously hypertensive rats and Wistar-Kyoto rats were assigned either to a sedentary lifestyle or to swimming training daily, and fetal histone deacetylase-mediated epigenetic modification and offspring vascular function of mesenteric arteries were analyzed. Maternal exercise ameliorated the impairment of acetylcholine-induced vasodilation without affecting sodium nitroprusside-induced vasodilation in mesenteric arteries from the hypertensive offspring. In accordance, maternal exercise reduced NADPH oxidase-4 (Nox4) protein to prevent the loss of nitric oxide generation and increased reactive oxygen species production in mesenteric arteries of hypertensive offspring. We further found that maternal exercise during pregnancy upregulated vascular SIRT1 (sirtuin 1) expression, leading to a low level of H3K9ac (histone H3 lysine 9 acetylation), resulting in the transcriptional downregulation of Nox4 in mesenteric arteries of hypertensive fetuses. These findings show that maternal exercise alleviates oxidative stress and the impairment of endothelium-dependent vasodilatation via SIRT1-regulated deacetylation of Nox4, which might contribute to improved vascular function in hypertensive offspring.