MiR-34a ameliorates arterial blood flow in rats with lower limb arteriosclerosis obliterans via Sirt1 signaling pathway

In this study, we investigated the impact of microRNA-34a (miR-34a) on lower limb arteriosclerosis obliterans in rats through the Sirtuin 1 (Sirt1) signaling pathway. Thirty-six Sprague-Dawley rats were divided into normal, model, and miR-34a mimics groups. Rats in the normal group were raised normally, while the model group underwent lower limb arteriosclerosis obliterans induction and received saline injections. The miR-34a mimics group also underwent arteriosclerosis obliterans modeling but received miR-34a mimics injections. Immunohistochemistry revealed significantly increased vascular endothelial growth factor (VEGF) expression in both model and miR-34a mimics groups compared to the normal group, with the miR-34a mimics group showing higher levels. Western blotting indicated elevated Sirt1 protein expression in both non-normal groups, with the miR-34a mimics group exhibiting significantly higher levels. Quantitative polymerase chain reaction (qPCR) demonstrated higher levels of miR-34a, VEGF mRNA, and Sirt1 mRNA in the model group compared to the normal group, but significantly lower levels than the miR-34a mimics group. Enzyme-linked immunosorbent assay (ELISA) showed increased VEGF content in the model group compared to the normal group but decreased compared to the miR-34a mimics group. Hemorrheological detection revealed a reduced PU index in both non-normal groups compared to the normal group, with a significant increase in the miR-34a mimics group compared to the model group. Overall, miR-34a upregulation enhanced VEGF expression in rat blood vessels, ameliorating arterial blood flow in lower limb arteriosclerosis obliterans through the Sirt1 signaling pathway.

MicroRNA-30a-3p: a potential noncoding RNA target for the treatment of arteriosclerosis obliterans

An increasing number of studies have shown that noncoding RNAs are involved in cardiovascular diseases. Our study shows that the expression of microRNA-30a-3p (miR-30a-3p) in patients with arteriosclerosis obliterans (ASO) of the lower extremities is significantly decreased after endovascular treatment, but its role is unclear. This study aims to explore the role of microRNA-30a-3p in ASO and its related mechanisms. Immunofluorescence and in situ hybridization costaining indicated that microRNA-30a-3p mostly exists in vascular smooth muscle cells (VSMCs). Furthermore, after transfection into VSMCs, microRNA-30a-3p inhibited VSMC proliferation, migration and phenotype switching. In addition, luciferase reporter and western blot analyses indicated that ROCK2 (Rho-related spiral coil 2 containing protein kinase) is a microRNA-30a-3p target gene, and participates in the microRNA-30a-3p mediated cell inhibitory effect. At last, the rat carotid artery was infected by lentivirus after balloon injury, which increased microRNA-30a-3p levels and apparently suppressed the formation of neointima in vivo. Overall, exogenous introduction of microRNA-30a-3p, a noncoding RNA with unlimited potential, may be a new approach to treat ASO.

miR-29a Regulates the Proliferation and Migration of Human Arterial Smooth Muscle Cells in Arteriosclerosis Obliterans of the Lower Extremities

BACKGROUND

The molecular mechanisms underlying the contribution of human arterial smooth muscle cells (HASMCs), one of the most important components of the arterial wall, to the pathogenesis of arteriosclerosis obliterans (ASO) remain elusive.

METHODS

The expression levels of miR-29a in arterial walls were analyzed via real-time-polymerase chain reaction. An ASO cell model was established to investigate the expression of miR-29a on HASMCs. The interaction between miR-29a and platelet-derived growth factor receptor B (PDGFRB) was detected by luciferase reporter assay, and the alteration of the expression of PDGFRB was determined in platelet-derived growth factor‑BB (PDGF-BB)-stimulated HASMCs transfected with miR-NC, miR-29a mimics, and miR-29a inhibitors. Further, HASMCs cell proliferation was investigated by cell counting kit-8 and EdU assays, and cell migrations were evaluated by Transwell and wound closure assays.

RESULTS

The expression of miR-29a was remarkably downregulated in the arterial walls of ASO patients compared with normal arterial walls. Furthermore, expression of miR-29a in HASMCs under PDGF-BB stimulation was lower than vehicle control. PDGFRB was identified as a target of miR-29a in HASMCs, and miR-29a inhibited the proliferation and migration in PDGF-BB-induced HASMCs, via regulating the expression of PDGFRB.

CONCLUSION

This study showed that miR-29a is downregulated in the arterial wall of ASO patients, as well as in the PDGF-BB-stimulated HASMCs. This alteration of miR-29a could upregulate target genes PDGFRB and inhibits the proliferation and migration of HASMCs. These findings discovered new mechanisms of ASO pathogenesis, and the miR-29a/PDGFRB axis could serve as potential therapy target of ASO.

Investigating the Role of the Posttranscriptional Gene Regulator MiR-24- 3p in the Proliferation, Migration and Apoptosis of Human Arterial Smooth Muscle Cells in Arteriosclerosis Obliterans

AIMS

To explore the expression of miR-24-3p in human arteries with arteriosclerosis obliterans (ASO) as well as the role of miR-24-3p in the pathogenesis of ASO.

METHODS

We used quantitative real-time PCR (qRT-PCR) and in situ hybridization to monitor miR-24-3p expression in human arteries. To investigate the effect of miR-24-3p on human arterial smooth muscle cells (HASMCs), we applied cell counting and EdU assays to monitor proliferation and transwell and wound healing assays to investigate migration and flow cytometry to investigate apoptosis. Furthermore, we applied 3'-untranslated region (3'-UTR) luciferase assays to investigate the role of miR-24-3p in targeting platelet-derived growth factor receptor B (PDGFRB) and c-Myc.

RESULTS

MiR-24-3p was mainly located in the media of arteries and was downregulated in ASO arteries compared with normal arteries. Platelet-derived growth factor BB (PDGF-BB) treatment reduced the expression of miR-24-3p in primary cultured HASMCs. MiR-24-3p mimic oligos inhibited the proliferation and migration, and promotes apoptosis of HASMCs. Our 3'-UTR luciferase assays confirmed that PDGFRB and c-Myc were targets of miR-24-3p.

CONCLUSION

The results suggest that miR-24-3p regulates the proliferation and migration of HASMCs by targeting PDGFRB and c-Myc. The PDGF/miR-24-3p/PDGFRB and PDGF/miR-24-3p/c-Myc pathways may play critical roles in the pathogenesis of ASO. These findings highlight the potential for new therapeutic targets for ASO.

MiR-142-3p attenuates the migration of CD4⁺ T cells through regulating actin cytoskeleton via RAC1 and ROCK2 in arteriosclerosis obliterans

The migration of CD4⁺ T cells plays an important role in arteriosclerosis obliterans (ASO). However, the molecular mechanisms involved in CD4⁺ T cell migration are still unclear. The current study is aimed to determine the expression change of miR-142-3p in CD4⁺ T cells from patients with ASO and investigate its role in CD4⁺ T cell migration as well the potential mechanisms involved. We identified by qRT-PCR and in situ hybridization that the expression of miR-142-3p in CD4⁺ T cells was significantly down-regulated in patients with ASO. Chemokine (C-X-C motif) ligand 12 (CXCL12), a common inflammatory chemokine under the ASO condition, was able to down-regulate the expression of miR-142-3p in cultured CD4⁺ T cells. Up-regulation of miR-142-3p by lentivirus-mediated gene transfer had a strong inhibitory effect on CD4⁺ T cell migration both in cultured human cells in vitro and in mouse aortas and spleens in vivo. RAC1 and ROCK2 were identified to be the direct target genes in human CD4⁺ T cells, which are further confirmed by dual luciferase assay. MiR-142-3p had strong regulatory effects on actin cytoskeleton as shown by the actin staining in CD4⁺ T cells. The results suggest that the expression of miR-142-3p is down-regulated in CD4⁺ T cells from patients with ASO. The down-regulation of miR-142-3p could increase the migration of CD4⁺ T cells to the vascular walls by regulation of actin cytoskeleton via its target genes, RAC1 and ROCK2.

[Haemodynamic role of blood-plasma circulating cell-free DNA and contained therein high-molecular-weight CpG-rich fraction in pathogenesis of arterial hypertension and atherosclerosis obliterans of carotid arteries]

The hydrodynamic resistance (HR) of blood is one of the components of the total peripheral resistance. High-molecular-weight DNA appears to decrease the HR in accordance with the Toms's effect. The present study was undertaken to investigate the HR and properties of cell-free DNA circulating in the blood plasma (hereinafter referred to as pDNA) of the control donors, patients suffering from either arterial hypertension (AH) alone or that combined with atherosclerotic lesions of the carotid arteries (CAs). Within the normal concentrations of pDNA, we revealed an inverse dependence of the HR thereupon and upon the content in pDNA of the high-molecular-weight CpG-rich fraction (CpG-DNA), i. e., a transcribed region of the ribosomal repeat (rDNA). A decrease or an increase in the pDNA concentration in all the patients examined was accompanied by an elevation of the rDNA concentration in the blood plasma. Exceeding a certain level thereof appeared to give rise to an increase in both the HR and arterial pressure (AP). Patients presenting with degree I essential AH were found to have a decreased endonuclease activity of the blood plasma, with the pDNA concentration being more than two-fold higher with no change in the rDNA content. Their HR appeared to be increased (p<0.01). Patients diagnosed as having degree II AH were characterized by a normal or decreased level of pDNA and an elevated content of pDNA, with the HR being slightly lowered. In patients presenting with atherosclerosis obliterans of the ACs, the initial manifestations of the lesions of the carotid arteries were typically revealed on the background of a lowered HR (p<0.05). All patients suffering from atherosclerotic lesions of the ACs could be subdivided into two groups, which in our opinion is probably associated with different various mechanisms of destructive damage to the arterial intima. In some of them, the pDNA concentration does not differ from the normal values, but in its composition, there is an increased content of rDNA, elevating as obliteration of the vessels' lumen increases, with the HR being decreased. The majority of them have degree II AH. In others, the pDNA concentration is by an order of magnitude higher than the normal values, while the rDNA content in pDNA is decreased, with the HR being elevated. Most of them have degree III AH. Pronounced and rough stenoses take an asymptomatic course in patients with decreased values of the HR and a slightly elevated level of pDNA and/or rDNA in the blood plasma. A higher level thereof leads to a rise in the HR and to the appearance of neurological symptomatology. Hence, CpG-DNA circulating in the composition of pDNA is a constantly acting endogenous blood factor decreasing the HR (the Toms's effect) and normalizing AP under physiological conditions, being however a cause of their increase and impairment of blood circulation in the pathogenesis of AH and atherosclerosis obliterans of the CAs.

Genetic analysis of HLA, NA and HPA typing in type 2 diabetes and ASO

We examined the genetic status of human leucocyte antigens (HLA), human platelet alloantigens (HPA) and neutrophil-specific antigens (NA) in patients with type 2 diabetes mellitus and diabetic arteriosclerosis obliterans (ASO). To our knowledge, the present study is the first report showing the relationship among three genetic factors in type 2 diabetes mellitus and ASO patients. HLA typing was performed by the polymerase chain reaction (PCR)-restriction fragment length polymorphism method. HPA-typing and NA-typing were by a PCR-sequence-specific primer method. The incidence of HLA-DRB1*1501 was found to be significant in type 2 diabetes and non-diabetic, particularly ASO-positive patients, compared to control subjects. There were no differences in NA1/NA2 between the control and diabetic or non-diabetic ASO groups. However, the frequency of NA2/NA2 in ASO-positive diabetes and non-diabetic ASO patients was significantly higher than controls. The a/b genotype of HPA-5a/5b was significantly lower in type 2 diabetes and non-diabetic ASO-positive patients than in controls. These findings suggest that genetic studies of HLA, NA and HPA could be useful to understand the pathogenesis of type 2 diabetes and ASO.

Risk-factor profile in severe, generalized, obliterating vascular disease

A 74-year-old woman had a history over 25 years of endarterectomy of both renal arteries, iliac venous thrombosis, pulmonary embolism, left internal carotid artery endarterectomy, coronary angioplasty, aortocoronary bypass grafting, occlusion of the right axillary artery, lower-limb claudication due to common iliac artery aneurysm, external iliac artery stenosis, multiple femoral artery stenoses, bifurcational stent grafting, occlusion of the left brachial artery and the right external iliac artery, and stroke. Assessment of the risk-factor profile revealed an absence of classic risk factors but the presence of the factor V Leiden mutation, the methylenetetrahydrofolate reductase AI298C mutation, the HFE C282Y mutation, plasminogen activator inhibitor-1 gene mutation, the -455 G/A fibrinogen gene polymorphism, the epsilon3/epsilon4 apolipoprotein E -675 4G gene polymorphism, and hyperhomocysteinemia. This case shows that severe, generalized, occlusive vascular disease may be due to the combination of various genetic risk factors for atherosclerosis and venous thromboembolism.

[In situ detection of EGF receptor mRNA in arteriosclerotic lesions in man: implications for the proliferative activity of smooth muscle cells]

Growth factors and growth factor receptors are considered to be key elements in the pathogenesis of arteriosclerosis and restenosis formation. To study the local expression of epidermal growth factor (EGF) receptor, plaque tissue specimens from advanced lesions (10 coronary, two femoral, seven carotid) of 19 patients were taken for in situ hybridization studies using an EGF-specific cDNA probe. In serial vascular sections of three lesions with increased focal cellularity, autoradiographic silver grains were clearly localized to intimal cells adjacent to the internal elastic lamina. EGF mRNA transcripts were not observed in the fibrous cap, the plaque shoulders, necrotic intimal areas, or in the media. In smooth muscle cells (SMCs) cultured from human plaque tissue, EGF increased SMC proliferative activity in a dose-dependent manner (ED50: 3-6 ng of EGF/ml). Proliferative responsiveness to EGF (10 ng/ml) was found to be significantly (p < 0.01) enhanced in coronary SMCs derived from restenotic lesions as compared to those from primary stenoses. The expression of EGF receptor mRNA in human atheromatous lesions could be of prognostic value to predict an increased SMC proliferative response to stimulatory growth factors.