Probucol mediates vascular remodeling after percutaneous transluminal angioplasty via down-regulation of the ERK1/2 signaling pathway

Decreased ZMIZ1 suppresses melanogenesis in vitiligo by regulating mTOR/AKT/GSK-3β-mediated glucose uptake

The loss of epidermal melanocytes is a distinguishing feature of vitiligo (VIT), a prevalent and long-lasting skin ailment. While various hypotheses exist to explain the cause of VIT, the precise mechanisms leading to this disease remain unclear. Zinc finger MIZ-type containing 1 (ZMIZ1) has a strong link with the development and occurrence of VIT. However, the exact role of ZMIZ1 and its underlying mechanisms in VIT are not well understood. Our study aims to illustrate that targeting ZMIZ1 is an effective therapeutic and prophylactic strategy for treating VIT. We obtained the RNA expression profile of VIT samples using RNA-seq and determined the locations and expression of ZMIZ1 in these samples via immunochemistry. Glucose uptake was analyzed through immunofluorescence and glucose uptake assay. We evaluated mRNA levels using qPCR and used plasmids transfection to knock down ZMIZ1 in PIG1 and PIG3V cell lines. The activation of the mTOR/AKT/GSK-3β signalling pathway was assessed using Western blotting analysis. We found that ZMIZ1 expression was decreased in VIT samples. Decreased ZMIZ1 expression inhibits the proliferation, migration, and invasion of melanocytes in vitro. Moreover, we revealed that decreased ZMIZ1 could also inhibit the glucose uptake of melanocytes in vitro. Decreased ZMIZ1 expression inhibits the activation of the mTOR/AKT/GSK-3β pathway and the expression of melanin synthesis-related proteins in melanocytes. Finally, we demonstrated that decreased ZMIZ1 may inhibit the cell viability of melanocytes and the synthesis of melanin by mTOR/AKT/GSK-3β-mediated oxidative stress in vitro. In conclusion, our study suggests that decreased ZMIZ1 suppresses melanogenesis in vitiligo by regulating the mTOR/AKT/GSK-3β-mediated glucose uptake in vitro, making ZMIZ1 an attractive therapeutic target for the treatment of VIT.

Microporous surface as a new solution for stent surface modification: A review

The introduction of coronary stents into clinical practice has reduced repeated patient visits compared with balloon angioplasty alone. Also, drug-eluting stents substantially reduced the restenosis incidence. Therefore, later complications related to the implantation of a stent coated with a cytostatic-containing polymer became more relevant. The mechanism of late stent complications is multifactorial. It is mainly due to the body's response to the prolonged indwelling of the drug carrier polymer on the coronary stent's surface. There is a trend towards the return of polymer-free drug coating technologies, which are implemented through certain modifications of stent surfaces for better drug retention and proper drug distribution. It is mainly achieved using drug depots in various reservoirs: grooves, nanoparticles in the matrix compound, micropores, through and blind micro reservoirs, etc. New promising technologies for crystallizing cytostatic drugs or depositing them in specially designed reservoirs show good preclinical and clinical results, comparable or even superior to approved coronary stents. Micropores as carriers for antiproliferative agents on the stent surface are a promising direction to rejecting the use of polymers in stents.

Wnt5a/Ror2 pathway contributes to the regulation of cholesterol homeostasis and inflammatory response in atherosclerosis

Atherosclerosis (AS) is characterized by lipids metabolism disorder and inflammatory response. Accumulating evidence has demonstrated that Wingless type 5a (Wnt5a) is implicated in cardiovascular diseases through non-canonical Wnt cascades. However, its precise role during the pathogenesis of AS is still unclear. Therefore, the present study aims to investigate the role and the underlying mechanism of Wnt5a/receptor tyrosine kinase-like orphan receptor 2 (Ror2) pathways in the promotion of AS process through affecting lipid accumulation and inflammation. In atherosclerotic clinical samples, Wnt5a levels were measured by using enzyme-linked immunosorbent assay (ELISA) assay. In vivo experiments were conducted by using apolipoprotein E knockout (apoE^-/-) mice model. Vascular smooth muscle cells (VSMCs) were applied for in vitro studies. Wnt5a was highly expressed in both of atherosclerotic clinical samples and apoE^-/- mice. The knockdown of Wnt5a significantly inhibited cholesterol accumulation and inflammatory response. Additionally, the lipopolysaccharide (LPS)-induced inflammation aggravated the cholesterol accumulation and decreased adenosine triphosphate (ATP)-binding cassette transporter A1 (ABCA1) expression in VSMCs. Depletion of intracellular cholesterol by β-cyclodextrin (β-CD) led to the upregulation of ABCA1 and the inhibition of inflammation. Conversely, the overexpression of Wnt5a inhibited ABCA1 expression, facilitated cholesterol accumulation, impared cholesterol efflux, promoted NF-κB nuclear translocation and the inflammatory cytokines secretion. Moreover, the knockdown of Ror2 increased ABCA1 expression and reduced Wnt5a-induced cholesterol accumulation and inflammatory responses. Furthermore, the knockdown of ABCA1 enhanced cholesterol accumulation and inflammatory response. Therefore, Wnt5a/Ror2 pathway was critical in regulating cholesterol homeostasis and inflammatory response, which might be a promising therapeutic target for AS therapy.

Anti-inflammatory activity of ezetimibe by regulating NF-κB/MAPK pathway in THP-1 macrophages

Inflammation plays a crucial role in atherosclerosis. Monocytes/macrophages are involved in the inflammatory process during atherogenesis. Here, we performed daily gavage of ezetimibe in apolipoprotein E-deficient mice fed with a high-fat diet and found that ezetimibe administration decreased the level of C-reactive protein significantly. To investigate the potential molecular mechanism, we employed microarray analysis on the cultured macrophages treated with Chol:MβCD in the presence or absence of ezetimibe. We found that ezetimibe dramatically down-regulated the expression of the tumor necrosis factor-α (TNF-α) gene. Consistent with the microarray results, TNF-α protein levels were inhibited by ezetimibe. Moreover, ezetimibe suppressed the promoter activity of TNF-α but not TNF-α lacking the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) binding domain in THP-1 cells treated with phorbol myristate acetate and Chol:MβCD. Furthermore, treatment of THP-1 macrophages with ezetimibe resulted in the degradation of IκB and subsequently inhibited nuclear translocation of NF-κB and its transcriptional activity. Inhibition of the mitogen-activated protein kinase (MAPK) pathway using PD98059 attenuated the reduction effect of ezetimibe on the expression of NF-κB. Collectively, our results demonstrated that the anti-inflammatory properties of ezetimibe in THP-1 macrophages are, at least in part, through suppression of NF-κB activation via the MAPK pathway. These data provide direct evidence for the potential application of ezetimibe in the prevention and treatment of inflammatory diseases.

Mice deficient in Mkp-1 develop more severe pulmonary hypertension and greater lung protein levels of arginase in response to chronic hypoxia

The mitogen-activated protein (MAP) kinases are involved in cellular responses to many stimuli, including hypoxia. MAP kinase signaling is regulated by a family of phosphatases that include MAP kinase phosphatase-1 (MKP-1). We hypothesized that mice lacking the Mkp-1 gene would have exaggerated chronic hypoxia-induced pulmonary hypertension. Wild-type (WT) and Mkp-1(-/-) mice were exposed to either 4 wk of normoxia or hypobaric hypoxia. Following chronic hypoxia, both genotypes demonstrated elevated right ventricular pressures, right ventricular hypertrophy as demonstrated by the ratio of the right ventricle to the left ventricle plus septum weights [RV(LV + S)], and greater vascular remodeling. However, the right ventricular systolic pressures, the RV/(LV + S), and the medial wall thickness of 100- to 300-microm vessels was significantly greater in the Mkp-1(-/-) mice than in the WT mice following 4 wk of hypobaric hypoxia. Chronic hypoxic exposure caused no detectable change in eNOS protein levels in the lungs in either genotype; however, Mkp-1(-/-) mice had lower levels of eNOS protein and lower lung NO production than did WT mice. No iNOS protein was detected in the lungs by Western blotting in any condition in either genotype. Both arginase I and arginase II protein levels were greater in the lungs of hypoxic Mkp-1(-/-) mice than those in hypoxic WT mice. Lung levels of proliferating cell nuclear antigen were greater in hypoxic Mkp-1(-/-) than in hypoxic WT mice. These data are consistent with the concept that MKP-1 acts to restrain hypoxia-induced arginase expression and thereby reduces vascular remodeling and the severity of pulmonary hypertension.

CHANGES IN microRNA (miR) profile and effects of miR-320 in insulin-resistant 3T3-L1 adipocytes

1. MicroRNAs (miRNAs) play essential roles in many biological processes. It is known that aberrant miRNA expression contributes to some pathological conditions. However, it is not known whether miRNAs play any role in the development of insulin resistance in adipocytes, a key pathophysiological link between obesity and diabetes. 2. To investigate the function of miRNAs in the development of insulin resistance, using miRNA microarray analysis we compared miRNA expression profiles between normal insulinsensitive 3T3-L1 adipocytes and 3T3-L1 adipocytes rendered insulin resistant following treatment with high glucose (25mmol/L) and high insulin (1 mol/L). Furthermore, adipocytes were transfected with specific antisense oligonucleotides against miRNA-320 (anti-miR-320 oligo) and the effects on the development of insulin resistance were evaluated. 3. We identified 50 upregulated and 29 downregulated miRNAs in insulin-resistant (IR) adipocytes, including a 50-fold increase in miRNA-320 (miR-320) expression. Using bioinformatic techniques, the p85 subunit of phosphatidylinositol 3-kinase (PI3-K) was found to be a potential target of miR-320. In experiments with anti-miR-320 oligo, insulin sensitivity was increased in IR adipocytes, as evidenced by increases in p85 expression, phosphorylation of Akt and the protein expression of the glucose transporter GLUT-4, as well as insulin-stimulated glucose uptake. These beneficial effects of anti-miR-320 oligo were observed only in IR adipocytes and not in normal adipocytes. 4. In conclusion, the miRNA profile changes in IR adipocytes compared with normal 3T3-L1 adipocytes. Anti-miR-320 oligo was found to regulate insulin resistance in adipocytes by improving insulin–PI3-K signalling pathways. The findings provide information regarding a potentially new therapeutic strategy to control insulin resistance.

Effects and underlying mechanisms of curcumin on the proliferation of vascular smooth muscle cells induced by Chol:MbetaCD

Proliferation of vascular smooth muscle cells (VSMCs) contributes to the development of various cardiovascular diseases. Curcumin, extracted from Curcumae longae, has been shown a variety of beneficial effects on human health, including anti-atherosclerosis by mechanisms poorly understood. In the present study, we attempted to investigate whether curcumin has any effect on VSMCs proliferation and the potential mechanisms involved. Our data showed curcumin concentration-dependently abrogated the proliferation of primary rat VSMCs induced by Chol:MbetaCD. To explore the underlying cellular and molecular mechanisms, we found that curcumin was capable of restoring caveolin-1 expression which was reduced by Chol:MbetaCD treatment. Moreover, curcumin abrogated the increment of phospho-ERK1/2 and nuclear accumulation of ERK1/2 in primary rat VSMCs induced by Chol:MbetaCD, which led to a suppression of AP-1 promoter activity stimulated by Chol:MbetaCD. In addition, curcumin was able to reverse cell cycle progression induced by Chol:MbetaCD, which was further supported by its down-regulation of cyclinD1 and E2F promoter activities in the presence of Chol:MbetaCD. Taking together, our data suggest curcumin inhibits Chol:MbetaCD-induced VSMCs proliferation via restoring caveolin-1 expression that leads to the suppression of over-activated ERK signaling and causes cell cycle arrest at G1/S phase. These novel findings support the beneficial potential of curcumin in cardiovascular disease.

Homeobox genes in normal and abnormal vasculogenesis

Homeobox containing genes are a family of transcription factors regulating normal development and controlling primary cellular processes (cell identity, cell division and differentiation) recently enriched by the discovery of their interaction with miRNAs and ncRNAs. Class I human homeobox genes (HOX genes) are characterized by a unique genomic network organization: four compact chromosomal loci where 39 sequence corresponding genes can be aligned with each other in 13 antero-posterior paralogous groups. The cardiovascular system is the first mesoderm organ-system to be generated during embryonic development; subsequently it generates the blood and lymphatic vascular systems. Cardiovascular remodelling is involved through homeobox gene regulation and deregulation in adult physiology (menstrual cycle and wound healing) and pathology (atherosclerosis, arterial restenosis, tumour angiogenesis and lymphangiogenesis). Understanding the role played by homeobox genes in endothelial and smooth muscle cell phenotype determination will be crucial in identifying the molecular processes involved in vascular cell differentiation, as well as to support future therapeutic strategies. We report here on the current knowledge of the role played by homeobox genes in normal and abnormal vasculogenesis and postulate a common molecular mechanism accounting for the involvement of homeobox genes in the regulation of the nuclear export of specific transcripts potentially capable of generating endothelial phenotype modification involved in new vessel formation.

Effects of rosiglitazone on the proliferation of vascular smooth muscle cell induced by high glucose

AIM

To investigate the effects of the sensitizer rosiglitazone on the proliferation of vascular smooth muscle cell (VSMC) induced by high glucose administration.

METHODS

VSMCs were isolated from rat thoracic aortas and cultured in 10% fetal bovine serum (FBS). VSMC proliferation was evaluated by methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay and cell counting. The cell cycle was examined by flow cytometry. The protein expressions of proliferating cell nuclear antigen (PCNA) and matrix metalloproteinases-2 (MMP-2) were evaluated by Western blotting. MMP-2 mRNA expression was analyzed by reverse transcription-polymerase chain reaction (RT-PCR) and gelatinolytic activity was determined by zymography.

RESULTS

Promoted VSMC proliferation significantly increased the number of VSMCs in the S phase, the expressions of PCNA and MMP-2, and MMP-2 activity, as well as decreased the proportion of VSMCs in the G(0)/G(1) phase. Rosiglitazone at a concentration of 10 mumol/L markedly inhibited glucose-induced VSMC proliferation (1.869 +/- 0.22 vs 0.820 +/- 0.15, P < 0.01). Concomitantly, rosiglitazone inhibited PCNA expression (0.96 +/- 0.07 vs 0.75 +/- 0.06, P < 0.05) and cell cycle progression from G(0)/G(1) to S phase (the proportion of VSMCs in the G(0)/G(1) and S phase were 69.6 +/- 3.96% vs 84.3 +/- 1.73% and 25.2 +/- 1.73% vs 10.1 +/- 1.42% (P < 0.01), respectively). Furthermore, rosiglitazone significantly decreased MMP-2 mRNA expression (0.98 +/- 0.08 vs 0.71 +/- 0.05, P < 0.05), protein expression (0.80 +/- 0.04 vs 0.64 +/- 0.03, P < 0.05) and MMP-2 activity (320 +/- 25% vs 248 +/- 21%, P < 0.05).

CONCLUSION

Rosiglitazone significantly inhibited VSMC proliferation, at least in part by inhibiting high glucose-induced G(1)-->S phase transition, PCNA expression and MMP-2 synthesis.

Asymmetric dimethylarginine induces TNF-alpha production via ROS/NF-kappaB dependent pathway in human monocytic cells and the inhibitory effect of reinioside C

Asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase (NOS) inhibitor, has been implicated in vascular inflammation through induction of reactive oxygen species (ROS) and proinflammatory genes in endothelial cells. However, relatively few attentions have been paid to the effect of ADMA on monocytes, one of the important cells throughout all stages of atherosclerosis. In the present study, we found that reinioside C, the main component extracted from Polygala fallax Hemsl., dose-dependently inhibited tumor necrosis factor-alpha (TNF-alpha) production induced by ADMA in monocytes, Furthermore, reinioside C attenuated ADMA-induced generation of reactive oxygen species and activation of nuclear factor-kappaB (NF-kappaB) activity in monocytes in a dose-dependent manner, this effect was inhibited by l-arginine (NOS substrate) and PDTC (inhibitor of NF-kappaB). These data suggest that reinioside C could attenuate the increase of TNF-alpha induced by exogenous ADMA through inhibition ROS/NF-kappaB pathway in monocytes.