Role of heme oxygenase in modulating endothelial function in mesenteric small resistance arteries of spontaneously hypertensive rats.

It has been proposed that endothelial dysfunction is due to the excessive degradation of nitric oxide (NO) by oxidative stress. The enzyme heme-oxygenase (HO) seems to exert a protective effect on oxidative stress in the vasculature, both in animal models and in humans. The objective of this study is to evaluate the effects of inhibition or activation of HO on endothelial function in mesenteric small resistance arteries of spontaneously hypertensive rats (SHR). Six SHR were treated with cobalt protoporphyrin IX 50 mg/Kg (CoPP), an activator of HO; six SHR with stannous mesoporphyrin 30 mg/Kg (SnMP), an inhibitor of HO, and six SHR with saline. As controls, six Wistar-Kyoto rats (WKY) were treated with CoPP, six WKY with SnMP, and six WKY with saline. Drugs were injected in the peritoneum once a week for 2 weeks. Systolic blood pressure (SBP) was measured (tail cuff method) before and after treatment. Mesenteric small resistance arteries were mounted on a micromyograph. Endothelial function was evaluated as a cumulative concentration-response curve to acetylcholine (ACH), before and after pre-incubation with N(G)-methyl-L-arginine (L-NMMA, inhibitor of NO synthase), and to bradykinin (BK). In SHR treatment with CoPP, improved ACH-and BK-induced vasodilatation (ANOVA p < 0.001) and this improvement was abolished by L-NMMA (ANOVA p < 0.001). SnMP was devoid of effects on endothelial function. In WKY, both activation and inhibition of HO did not substantially affect endothelium-mediated vasodilatation. The stimulation of HO seems to induce an improvement of endothelial dysfunction in SHR by possibly reducing oxidative stress and increasing NO availability

Effect of antihypertensive treatments on insulin signalling in lympho-monocytes of essential hypertensive patients: a pilot study.

It was previously demonstrated that metabolic syndrome in humans is associated with an impairment of insulin signalling in circulating mononuclear cells. At least in animal models of hypertension, angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARB) may correct alterations of insulin signalling in the skeletal muscle. In the first study, we investigated the effects of a 3-month treatment with an ARB with additional PPARγ agonist activity, telmisartan, or with a dihydropyridine calcium channel blocker, nifedipine, on insulin signalling in patients with mild-moderate essential hypertension. Insulin signalling was evaluated in mononuclear cells by isolating them through Ficoll-Paque density gradient centrifugation and protein analysis by Western Blot. An increased expression of mTOR and of phosphorylated (active) mTOR (p-mTOR) was observed in patients treated with telmisartan, but not in those treated with nifedipine, while both treatments increased the cellular expression of glucose transporter type 4 (GLUT-4). We also investigated the effects of antihypertensive treatment with two drug combinations on insulin signalling and oxidative stress. Twenty essential hypertensive patients were included in the study and treated for 4 weeks with lercanidipine. Then they were treated for 6 months with lercanidipine + enalapril or lercanidipine + hydrochlorothiazide. An increased expression of insulin receptor, GLUT-4 and an increased activation of p70S6K1 were observed during treatment with lercanidipine + enalapril but not with lercanidipine + hydrochlorothiazide. In conclusion, telmisartan and nifedipine are both effective in improving insulin signalling in human hypertension; however, telmisartan seems to have broader effects. The combination treatment lercanidipine + enalapril seems to be more effective than lercanidipine + hydrochlorothiazide in activating insulin signalling in human lympho-monocytes

Reduction of High Cholesterol Levels by a Preferably Fixed-Combination Strategy as the First Step in the Treatment of Hypertensive Patients with Hypercholesterolemia and High/Very High Cardiovascular Risk: A Consensus Document by the Italian Society of Hypertension

The primary and secondary prevention strategies of atherosclerotic cardiovascular disease (ASCVD) largely rely on the management of arterial hypertension and hypercholesterolemia, two major risk factors possibly linked in pathophysiological terms by the renin-angiotensin system activation and that often coexist in the same patient synergistically increasing cardiovascular risk. The classic pharmacologic armamentarium to reduce hypercholesterolemia has been based in the last two decades on statins, ezetimibe, and bile acid sequestrants. More recently numerous novel, additive resources targeting different pathways in LDL cholesterol metabolism have emerged. They include drugs targeting the proprotein convertase subtilisin/kexin type 9 (PCSK9) (inhibitory antibodies; small-interfering RNAs), the angiopoietin-like protein 3 (inhibitory antibodies), and the ATP-citrate lyase (the inhibitory oral prodrug, bempedoic acid), with PCSK9 inhibitors and bempedoic acid already approved for clinical use. With the potential of at least halving LDL cholesterol levels faster and more effectively with the addition of ezetimibe than with high-intensity statin alone, and even more with the addition of the novel available drugs, this document endorsed by the Italian Society of Hypertension proposes a novel paradigm for the treatment of the hypertensive patient with hypercholesterolemia at high and very high ASCVD risk. Our proposal is based on the use as a first-line of a preferably fixed combination of lipid-lowering drugs, under the motto “Our goal: achieve control. No setback: combine and check”

Decomposition cross-correlation for analysis of collagen matrix deformation by single smooth muscle cells

Microvascular remodeling is known to depend on cellular interactions with matrix tissue. However, it is difficult to study the role of specific cells or matrix elements in an in vivo setting. The aim of this study is to develop an automated technique that can be employed to obtain and analyze local collagen matrix remodeling by single smooth muscle cells. We combined a motorized microscopic setup and time-lapse video microscopy with a new cross-correlation based image analysis algorithm to enable automated recording of cell-induced matrix reorganization. This method rendered 60–90 single cell studies per experiment, for which collagen deformation over time could be automatically derived. Thus, the current setup offers a tool to systematically study different components active in matrix remodeling

Modulation of vascular reactivity by perivascular adipose tissue (PVAT)

Purpose of Review: In this review we discuss the role of perivascular adipose tissue (PVAT) in the modulation of vascular contractility and arterial pressure, focusing on the role of the renin-angiotensin-aldosterone system and oxidative stress/inflammation. Recent Findings: PVAT possesses an relevant endocrine-paracrine activity, which may be altered in several pathophysiological and clinical conditions. During the last two decades it has been shown PVAT may modulate vascular reactivity. It has also been previously demonstrated that inflammation in adipose tissue may be implicated in vascular dysfunction. In particular, adipocytes secrete a number of adipokines with various functions, as well as several vasoactive factors, together with components of the renin-angiotensin system which may act at local or at systemic level. It has been shown that the anticontractile effect of PVAT is lost in obesity, probably as a consequence of the development of adipocyte hypertrophy, inflammation, and oxidative stress. Summary: Adipose tissue dysfunction is interrelated with inflammation and oxidative stress, thus contributing to endothelial dysfunction observed in several pathological and clinical conditions such as obesity and hypertension. Decreased local adiponectin level, macrophage recruitment and infiltration, and activation of renin-angiotensin-aldosterone system could play an important role in this regards