ORAI channels in cellular remodeling of cardiorespiratory disease

Cardiorespiratory disease, which includes systemic arterial hypertension, restenosis, atherosclerosis, pulmonary arterial hypertension, asthma, and chronic obstructive pulmonary disease (COPD) are highly prevalent and devastating diseases with limited therapeutic modalities. A common pathophysiological theme to these diseases is cellular remodeling, which is contributed by changes in expression and activation of ion channels critical for either excitability or growth. Calcium (Ca²⁺) signaling and specifically ORAI Ca²⁺ channels have emerged as significant regulators of smooth muscle, endothelial, epithelial, platelet, and immune cell remodeling. This review details the dysregulation of ORAI in cardiorespiratory diseases, and how this dysregulation of ORAI contributes to cellular remodeling.     

The nucleotide analogue 3-deazaadenosine prevents neointima-formation after balloon injury

We have recently shown that 3-deazaadenosine (c3Ado) inhibits atherogenesis in mice. We studied whether its anti-inflammatory capacity would also affect neointima-formation after balloon injury. Sprague Dawley rats underwent balloon angioplasty. C3Ado was administered orally, starting 5 days prior to the balloon injury and continued for 2 weeks. Fourteen days after balloon injury the intima/media ratio in the c3Ado-treated group was reduced by 67% (p < 0.001) and luminal stenosis by 50% (p < 0.001). Neointimal cellular density was decreased by 25% (p < 0.001) and the induction of c-Jun and ki67 was markedly lower. The reduction of the intima/media ratio was still observed 3 months after balloon injury. Furthermore, a c3Ado-dependent inhibition of PDGF-mediated ERK-activation and proliferation could be demonstrated.Short-term administration of C3Ado inhibits neointima-formation in rats for at least 3 months after injury. The present findings implicate that c3Ado may be useful as an inhibitor of restenosis-formation after balloon angioplasty in humans.     

Vascular smooth muscle cell proliferation as a therapeutic target. Part 2: Natural products inhibiting proliferation

Many natural products have been so far tested regarding their potency to inhibit vascular smooth muscle cell proliferation, a process involved in atherosclerosis, pulmonary hypertension and restenosis. Compounds studied in vitro and in vivo as VSMC proliferation inhibitors include, for example indirubin-3′-monoxime, resveratrol, hyperoside, plumericin, pelargonidin, zerumbone and apamin. Moreover, taxol and rapamycin, the most prominent compounds applied in drug-eluting stents to counteract restenosis, are natural products. Numerous studies show that natural products have proven to yield effective inhibitors of vascular smooth muscle cell proliferation and ongoing research effort might result in the discovery of further clinically relevant compounds.     

PolarCath cryoplasty enhances smooth muscle cell apoptosis in a rabbit iliac artery model: an experimental in vivo controlled study

Purpose

To in vivo investigate the histological response after single and double cryoplasty therapy in a rabbit iliac artery model.

Materials and methods

In total, 40 New Zealand White rabbits underwent percutaneous transluminal angioplasty of the iliac artery using either PolarCath balloon or a conventional angioplasty balloon of equal diameter. Arterial injury, inflammatory response and smooth muscle cells (SMC) apoptosis with the TUNEL (Terminal deoxynucleotidyl transferase dUTP Nick End Labeling) immunohistochemical assay were analyzed. Rabbits were divided between single or double balloon inflation and histological results were compared between cryoplasty and control angioplasty both at 30 min and 72 h.

Results

Arterial injury and wall inflammation scores were low and similar between cryoplasty and control groups after single and double balloon inflation. Compared to conventional balloon angioplasty, Polarcath cryoplasty demonstrated superior SMC apoptosis after single inflation at 30 min [12.0 ± 1.2 cells/(0.025 mm)2 vs 7.0 ± 1.5 cells/(0.025 mm)², p = 0.002], single inflation at 72 h [9.0 ± 1.0 cells/(0.025 mm)² vs 5.4 ± 1.4 cells/(0.025 mm)², p = 0.001], double inflation at 30 min [11.6 ± 1.5 cells/(0.025 mm)² vs 6.8 ± 1.4 cells/(0.025 mm)², p = 0.001] and double inflation at 72 h [9.2 ± 0.8 cells/(0.025 mm)² vs 5.0 ± 0.7 cells/(0.025 mm)², p = 0.001]. There were no significant differences in apoptosis between single and double cryoplasty application at 30 min and 72 h.

Conclusion

Cryoplasty demonstrated superior rates of SMC apoptosis at 30 min and 72 h and was associated to relatively low arterial injury and inflammation scores. An immediate second PolarCath inflation did not achieve superior apoptosis.     

Critical role of nucleotide-binding oligomerization domain-like receptor 3 in vascular repair

Vascular remodeling characterized by hyperproliferative neointima formation is an unfavorable repair process that is triggered by vascular damage. This process is characterized by an increased local inflammatory and proliferative response that critically involves the pro-inflammatory cytokine interleukin-1β (IL-1β). IL-1β is expressed and cytosolically retained as a procytokine that requires additional processing prior to exerting its pro-inflammatory function. Maturation and release of pro IL-1β is governed by a cytosolic protein scaffold that is known as the inflammasome.Here we show that NLRP3 (NOD-like receptor family, pryin domain containing 3), an important activating component of the inflammasome, is involved in neointima formation after vascular injury. NLRP3 deficiency itself does not affect the functional cardiovascular phenotype and does not alter peripheral differential blood counts. However, neointima development following wire injury of the carotid artery was significantly decreased in NLRP3-deficient mice as compared to wild-type controls. In all, NLRP3 plays a non-redundant role in vascular damage mediated neointima formation.Our data establish NLRP3 as a key player in the response to vascular damage, which could open new avenues to therapeutic intervention.     

Isoeugenodilol inhibits smooth muscle cell proliferation and neointimal thickening after balloon injury via inactivation of ERK1/2 pathway

The purpose of this study was to determine the efficacy and the possible mechanism of action of the synthesized drug isoeugenodilol (a new third-generation β-adrenoceptor blocker) on the growth factor-induced proliferation of cultured rat vascular smooth muscle cells (VSMCs) and neointimal formation in a rat carotid arterial balloon injury model. Isoeugenodilol significantly inhibited 10% FBS, 20 ng/ml PDGF-BB, and 20 ng/ml vascular endothelial growth factor (VEGF)-induced proliferation. In accordance with these findings, isoeugenodilol revealed blocking of the FBS-inducible progression through the G₀/G₁ to the S phase of the cell cycle in synchronized cells. Neointimal formation, measured 14 days after injury, was reduced by the oral administration of isoeugenodilol (10 mg/kg/day). In an in vitro assay, isoeugenodilol inhibited the migration of VSMCs stimulated by PDGF-BB. These findings indicate that isoeugenodilol shows an inhibitory potency on neointimal formation due to inhibition of both migration and proliferation of VSMCs. In addition, isoeugenodilol in concentration-dependent manner decreased the levels of phosphorylated ERK1/2 in both VSMCs and balloon-injured carotid arteries. The levels of phosphorylated MEK1/2 and Pyk2 as well as intracellular Ca²⁺ and reactive oxygen species (ROS) were in concentration-dependent manner reduced by isoeugenodilol. Taken together, these results indicate that isoeugenodilol may suppress mitogen-stimulated proliferation and migration partially through inhibiting cellular ROS and calcium, and hence, through activation of the Pyk2-ERK1/2 signal pathway. This suggests that isoeugenodilol has potential for the prevention of atherosclerosis and restenosis.     

Profound negative regulatory effects by resveratrol on vascular smooth muscle cells: a role of p53-p21(WAF1/CIP1) pathway

We investigated the role of resveratrol, a polyphenol rich in red wine, in cell cycle progression and apoptosis of vascular smooth muscle cells (VSMCs). Resveratrol inhibited the growth of human aortic VSMCs at concentrations as low as 1 microM. This was due to the profound dose-dependent inhibition of DNA synthesis by resveratrol. DNA synthesis was more effectively inhibited when cells were pretreated with resveratrol. Resveratrol caused a dose-dependent increase in intracellular p53 and p21(WAF1/CIP1) levels. At lower concentrations (6.25-12.5 microM), resveratrol effectively blocked cell cycle progression of serum-stimulated VSMCs without inducing apoptosis, while the higher concentration of resveratrol (25 microM) selectively induced apoptosis in the same VSMCs. Intriguingly, however, the same high concentration of resveratrol could not induce apoptosis in quiescent VSMCs. These differential biological effects of resveratrol on quiescent and proliferating VSMCs suggest that resveratrol may be capable of selectively eliminating abnormally proliferating VSMCs of the arterial walls in vivo.     

Geometric design improvements for femoral graft-artery junctions mitigating restenosis

The present study is based on the hypothesis that nonuniform hemodynamics, represented by large time-averaged wall shear stress gradients, trigger abnormal biological processes leading to rapid restenosis, i.e. excessive tissue overgrowth and renewed plaque formation, and hence early graft failure. It implies that this problem may be significantly mitigated by finding graft-artery bypass configurations for which the wall shear stress gradient is approximately zero and hence nearly uniform hemodynamics is achieved. These fluid flow and geometric design considerations are applied to four different end-to-side anastomoses for the distal end of a femoral artery bypass with an appropriate test input pulse and a typical 20–80 flow division. A validated finite-volume code has been used to compute the transient three-dimensional velocity vector fields, wall shear stress distributions and surface contours of the wall shear stress gradients. It is shown that large anastomotic flow areas, small continuously changing bifurcation angles, and smooth junction wall curvatures reduce local time-averaged wall shear stress gradients significantly and hence should mitigate restenosis.     

血管成形术后原癌基因c－fos、c－myc表达的研究

ｃ－ｆｏｓ、ｃ－ｍｙｃ是两种参与细胞增殖的原癌基因。动脉血管成形术（ＰＴＡ）后的血管再狭窄,是由于血管壁平滑肌细胞增生所致。利用大白兔建立的试验动物模型,提取ＰＴＡ后不同时间间隔的动脉壁总ＲＮＡ,并用斑点杂交法分析两种原癌基因的表达情况,发现了ｃ－ｆｏｓ和ｃ－ｍｙｃ的基因分别在术后１５分钟内转录活性提高,并分别在３０分钟和第２小时达到高峰。