Mevalonate pathway is a novel target for hypertension

Ibandronate promotes autophagy by inhibiting Rac1–mTOR signaling pathway in vitro and in vivo

We previously reported that ibandronate (IBAN) could improve endothelial function in spontaneously hypertensive rats. However, the mechanism by which IBAN improves endothelial function is unclear. The IBAN-induced autophagic process in vitro experiments were determined by detection of LC3, Beclin1, and P62 protein levels via western blotting. The autophagy flux was detected by confocal microscopy and transmission electron microscopy. For in vivo experiments, spontaneously hypertensive rats were orally administered with IBAN. Utilizing angiotensin II (Ang II) to stimulate the human umbilical vein endothelial cells (HUVECs) and human pulmonary microvascular endothelial cells (HPMECs) as a model of endothelial cell injury in hypertension, we found that IBAN promoted autophagy and protected cell viability in Ang II-treated-endothelial cells while these effects could be reversed by autophagy inhibitor. In terms of mechanism, IBAN treatment decreased the levels of Rac1 and mammalian target of rapamycin (mTOR) pathway. Activating either Rac1 or mTOR could reverse IBAN-induced autophagy. Furthermore, the in vivo experiments also indicated that IBAN promotes autophagy by downregulating Rac1-mTOR. Taken together, our results firstly revealed that IBAN enhances autophagy via inhibiting Rac1-mTOR signaling pathway, and thus alleviates Ang II-induced injury in endothelial cells.

Effects of pitavastatin on cardiac structure and function and on prevention of atrial fibrillation in elderly hypertensive patients: a prospective study of 2-years' follow-up

BACKGROUND

The aim of this prospective study was to determine whether statin therapy (pitavastatin) has a beneficial effect on the prevention of new-onset atrial fibrillation (AF) in elderly patients with hypertension (HTN) and to evaluate the relationships among statin treatment, the development of AF, and left atrial (LA) and ventricular (LV) structure and function.

METHODS AND RESULTS

We enrolled eligible elderly patients (≥65 years old) with HTN and LV hypertrophy until the number of patients reached 110 in both groups. The 110 patients with HTN who needed statin therapy (HTN with statin group) were started on pitavastatin (1-2 mg/day), and both groups continued with appropriate medication for HTN. LV and LA structure and function were examined by conventional and speckle-tracking echocardiography at baseline and after 1 year. LA volume and function in the HTN with statin group improved more than in the HTN without statin group. There was a significant difference in survival free of new-onset AF in the patients with and without statin therapy during the 2-year follow-up (hazard ratio: 0.32, P=0.027).

CONCLUSIONS

Pitavastatin had a beneficial effect on LV diastolic function and LA structure and function in elderly patients with HTN. Pitavastatin treatment may be associated with a lower incidence of new-onset AF.