Marfan syndrome (MFS), caused by mutations in the FBN1 gene, predisposes individuals to thoracic aortic aneurysm (TAA), a life-threatening complication. Recent studies ha... More
Marfan syndrome (MFS), caused by mutations in the FBN1 gene, predisposes individuals to thoracic aortic aneurysm (TAA), a life-threatening complication. Recent studies have suggested that dysregulated mechanosignaling in aortic smooth muscle cells (SMCs) plays a pivotal role in TAA pathogenesis in MFS. However, the key molecular drivers remain largely undefined. Here we identify fibroblast growth factor 12 (FGF12) as a novel mediator of aberrant mechanosignaling in aortic SMCs during TAA formation in MFS. FGF12 is markedly upregulated in aortic SMCs of thoracic aneurysmal aortas from Fbn1C1039G/+ MFS mice and from patients with MFS. Mechanistically, FGF12 expression is induced by transforming growth factor-β/SMAD signaling and by cyclic mechanical stretch in aortic SMCs. FGF12 upregulates the expression of angiotensin II (AngII) and AngII type 1 receptor (AT1R), thereby activating the AngII/AT1R signaling pathway. FGF12-induced AT1R activation promotes aberrant mechanosignaling, as indicated by increased RhoA-GTP levels, stress fiber formation, focal adhesion assembly and focal adhesion kinase phosphorylation, ultimately leading to increased aortic SMC stiffness. In vivo studies using Fgf12 heterozygous (Fgf12+/−) mice reveal that Fgf12 haploinsufficiency significantly ameliorates AngII/β-aminopropionitrile-induced TAA formation, accompanied by reduced AT1R signaling and attenuation of aberrant mechanosignaling in the thoracic aortas. Furthermore, in Fbn1C1039G/+ MFS mice, Fgf12 haploinsufficiency (Fgf12+/−Fbn1C1039G/+) substantially mitigates TAA progression and arterial stiffening, while alleviating dysregulated mechanosignaling in thoracic aortic SMCs. Collectively, these findings identify FGF12 as a critical regulator of aberrant mechanosignaling in aortic SMCs and a key contributor to TAA formation in MFS. Less
Objective Previous studies have revealed associations between hyperuricemia and microvascular diseases, but the
Urotensin II (UII) is a potent vasoactive peptide and mitogenic agent to induce proliferation of various cells including vascular smooth muscle cells (VSMCs). In this stu... More
Urotensin II (UII) is a potent vasoactive peptide and mitogenic agent to induce proliferation of various cells including vascular smooth muscle cells (VSMCs). In this study, we examined the effects of a novel UII receptor (UT) antagonist, KR-36676, on vasoconstriction of aorta and proliferation of aortic SMCs. In rat aorta, UII-induced vasoconstriction was significantly inhibited by KR-36676 in a concentration-dependent manner. In primary human aortic SMCs (hAoSMCs), UII-induced cell proliferation was significantly inhibited by KR-36676 in a concentration-dependent manner. In addition, KR-36676 decreased UII-induced phosphorylation of ERK, and UII-induced cell proliferation was also significantly inhibited by a known ERK inhibitor U0126. In mouse carotid ligation model, intimal thickening of carotid artery was dramatically suppressed by oral treatment with KR-36676 (30 mg/ kg/day) for 4 weeks compared to vehicle-treated group. From these results, it is indicated that KR-36676 suppress UII-induced proliferation of VSMCs at least partially through inhibition of ERK activation, and that it also attenuates UII-induced vasoconstriction and vascular neointima formation. Our study suggest that KR-36676 may be an attractive candidate for the pharmacological management of vascular dysfunction.
Keywords: ERK; KR-36676; Proliferation; Smooth muscle; Urotensin II; Urotensin II receptor antagonist. Less
Angelica sinensis has been used to attenuate cold-induced cutaneous vasospasm syndrome, such as Raynaud’s disease and frostbite, in China for many years. Ferulic acid (... More
Angelica sinensis has been used to attenuate cold-induced cutaneous vasospasm syndrome, such as Raynaud’s disease and frostbite, in China for many years. Ferulic acid (PubChem CID: 445858) and Z-ligustilide (PubChem CID: 529865), two major components extracted from Angelica sinensis, had been reported to inhibit vasoconstriction induced by vasoconstrictors. In this study, the pharmacological interaction in regulating cold-induced vascular smooth muscle cell contraction via cold-sensing protein TRPM8 and TRPA1 was analyzed between ferulic acid and Z-ligustilide. Pharmacological interaction on inhibiting [Ca2+]i influx evoked by TRPM8 agonist WS-12 or TRPA1 agonist ASP 7663 as well as cold-induced upregulation of TRPM8 was determined using isobolographic analysis. The isobolograms demonstrated that the combinations investigated in this study produced a synergistic interaction. Combination effect of two components in inhibiting RhoA activation and phosphorylation of MLC20 induced by WS-12 or ASP 7663 was also being quantified. These findings suggest that the therapeutic effect of Angelica sinensis on cold-induced vasospasm may be partially attributed to combinational effect, via TRPM8 and TPRA1 way, between ferulic acid and Z-ligustilide. Less
The root of Cynanchum wilfordii (C. wilfordii) contains several biologically active compounds which have been used as traditional medicines in Asia. In the present study,... More
The root of Cynanchum wilfordii (C. wilfordii) contains several biologically active compounds which have been used as traditional medicines in Asia. In the present study, we evaluated the anti-inflammatory effects of an ethanol root extract of C. wilfordii (CWE) on tumor necrosis factor (TNF)-α-stimulated human aortic smooth muscle cells (HASMCs). The inhibitory effects of CWE on vascular cell adhesion molecule (VCAM)-1 expression under an optimum extraction condition were examined. CWE suppressed the expression of VCAM-1 and ICAM-1 and the adhesion of THP-1 monocytes to the TNF-α-stimulated HASMCs. Consistent with the in vitro observations, CWE inhibited the aortic expression of ICAM-1 and VCAM-1 in atherogenic diet-fed mice. CWE also downregulated the expression of nuclear factor-κB (NF-κB p65) and its uclear translocation in the stimulated HASMCs. In order to identify the active components in CWE, we re-extracted CWE using several solvents, and found that the ethyl acetate fraction was the most effective in suppressing the expression of VCAM-1 and ICAM-1. Four major acetophenones were purified from the ethyl acetate fraction, and two components, p-hydroxyacetophenone and cynandione A, potently inhibited the expression of ICAM-1 and VCAM-1 in the stimulated HASMCs. We assessed and determined the amounts of these two active components from CWE, and our results suggested that the root of C. wilfordii and its two bioactive acetophenones may be used for the prevention and treatment of atherosclerosis and vascular inflammatory diseases. Less
Vascular injury after chronic hypoxia leads to endothelial injury and structural damage to tight junctions (TJs), thereby resulting in a variety of cardiovascular disease... More
Vascular injury after chronic hypoxia leads to endothelial injury and structural damage to tight junctions (TJs), thereby resulting in a variety of cardiovascular diseases. Thus, attenuating hypoxia-induced damage has great significance for the prevention and treatment of cardiovascular disease. The aim of this study was to investigate whether the endothelial protection conferred by tongxinluo (TXL), a traditional Chinese medicinal compound, is related to its regulation of TJ protein expression. In vivo, we found that TXL could promote hypoxia-induced angiogenesis in lung and liver tissue. In vitro, we found that CoCl2 treatment significantly reduced the expression of the TJ proteins occludin, claudin-1, VE-cadherin, and beta-catenin in cultured human cardiac microvascular endothelial cells. TXL pretreatment abrogated the CoCl2-induced downregulation of these TJ proteins. Conversely, overexpression of Krüppel-like factor 4 (KLF4) inhibited the expression of TJ proteins in human cardiac microvascular endothelial cells, an effect that was reversed by TXL pretreatment. Further experiments showed that TXL could promote endothelial cell proliferation by increasing KLF4 phosphorylation, thereby reversing the effect of KLF4 on the expression of TJ proteins. These findings provide a new molecular mechanism for the TXL-induced increase in TJ protein expression Less
Background Illicium verum Hook. fil. Illiciaceae (Illicium v.) has been traditionally used in herbal medicine for treating many inflammatory diseases, including skin infl... More
Background Illicium verum Hook. fil. Illiciaceae (Illicium v.) has been traditionally used in herbal medicine for treating many inflammatory diseases, including skin inflammation and rheumatism. We investigated its use as a preventive agent against inflammatory and vascular diseases in a murine model of atherosclerosis using apolipoprotein E-knockout (ApoE−/−) mice fed on a high-fat diet (HFD). Methods We investigated the effect of Illicium v. on cytotoxicity, NF-κB activity, and adhesion molecule expression in TNF-α – stimulated HASMCs (Human Aortic smooth muscle cells). ApoE−/−mice, fed a HFD and treated daily for 12 weeks by oral administration of either Illicium v. (100 or 200 mg/kg) or atorvastatin (10 mg/kg), were evaluated for atherosclerotic lesions and inflammatory responses by performing Oil red O and iNOS staining, respectively. Expression of inflammatory cytokines (i.e., NF-κB, TNF-α, IL-1β, COX, IκB-α, Iκκ-α/β) and adhesion molecules in the aorta were measured by western blot analysis. Results In TNF-α-stimulated HASMCs, Illicium v. treatment decreased NF-κB transcriptional activity, and NF-κB protein levels were reduced in a dose-dependent manner over a range of 10–100 μg/mL Illicium v. Also, Illicium v. attenuated the expression of adhesion molecules that are responsible for inflammation in these cells. In animal experiments, treatment with Illicium v. or atorvastatin counteracted the characteristic changes in body weight, blood pressure, and lipid levels seen in HFD-fed ApoE−/− mice. In addition, Illicium v. treatment reduced aortic atherosclerotic plaque lesions and the immunoreactivity of iNOS activation. The aortic expression of inflammatory adhesion molecules and cytokines (TNF-α, IL-1β, NF-κB, COX, IκB-α, Iκκ-α/β), which is characteristic of HFD-fed ApoE−/− mice, was attenuated by 12-week treatment with daily oral administration of Illicium v. or atorvastatin, and the most potent effect was seen with the herbal tincture. Conclusions The beneficial effects of Illicium v. are consistent with a significant decrease in the iNOS-mediated inflammatory response, resulting in reduction of inflammation-associated gene expression. Treatment with Illicium v. may be the basis of a novel therapeutic strategy for hyperlipidemia-atherosclerosis. Less
We investigated transcriptional control of gene expression in human abdominal aortic aneurysm (AAA). We previously identified 3274 differentially expressed genes in human... More
We investigated transcriptional control of gene expression in human abdominal aortic aneurysm (AAA). We previously identified 3274 differentially expressed genes in human AAA tissue compared to non-aneurysmal controls. Four expressed transcription factors (ELF1, ETS2, STAT5 and RUNX1) were selected for genome-wide chromatin immunoprecipitation. Transcription factor binding was enriched in 4760 distinct genes (FDR < 0.05), of which 713 were differentially expressed in AAA. Functional classification using Gene Ontology (GO), KEGG, and Network Analysis revealed enrichment in several biological processes including “leukocyte migration” (FDR = 3.09 × 10−05) and “intracellular protein kinase cascade” (FDR = 6.48 × 10−05). In the control aorta, the most significant GO categories differed from those in the AAA samples and included “cytoskeleton organization” (FDR = 1.24 × 10−06) and “small GTPase mediated signal transduction” (FDR = 1.24 × 10−06). Genes up-regulated in AAA tissue showed a highly significant enrichment for GO categories “leukocyte migration” (FDR = 1.62 × 10−11), “activation of immune response” (FDR = 8.44 × 10−11), “T cell activation” (FDR = 4.14 × 10−10) and “regulation of lymphocyte activation” (FDR = 2.45 × 10−09), whereas the down-regulated genes were enriched in GO categories “cytoskeleton organization” (FDR = 7.84 × 10−05), “muscle cell development” (FDR = 1.00 × 10−04), and “organ morphogenesis” (FDR = 3.00 × 10−04). Quantitative PCR assays confirmed a sub-set of the transcription factor binding sites including those in MTMR11, DUSP10, ITGAM, MARCH1, HDAC8, MMP14, MAGI1, THBD and SPOCK1. Less
Autophagy, a type II programmed cell death, is essential for cell survival under stress, e.g. lung injury, and bone marrow-derived mesenchymal stem cells (BM-MSCs) have g... More
Autophagy, a type II programmed cell death, is essential for cell survival under stress, e.g. lung injury, and bone marrow-derived mesenchymal stem cells (BM-MSCs) have great potential for cell therapy. However, the mechanisms underlying the BM-MSC activation of autophagy to provide a therapeutic effect in ischaemia/reperfusion-induced lung injury (IRI) remain unclear. Thus, we investigate the activation of autophagy in IRI following transplantation with BM-MSCs. Seventy mice were pre-treated with BM-MSCs before they underwent lung IRI surgery in vivo. Human pulmonary micro-vascular endothelial cells (HPMVECs) were pre-conditioned with BM-MSCs by oxygen-glucose deprivation/reoxygenation (OGD) in vitro. Expression markers for autophagy and the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) signalling pathway were analysed. In IRI-treated mice, administration of BM-MSCs significantly attenuated lung injury and inflammation, and increased the level of autophagy. In OGD-treated HPMVECs, co-culture with BM-MSCs attenuated endothelial permeability by decreasing the level of cell death and enhanced autophagic activation. Moreover, administration of BM-MSCs decreased the level of PI3K class I and p-Akt while the expression of PI3K class III was increased. Finally, BM-MSCs-induced autophagic activity was prevented using the inhibitor LY294002. Administration of BM-MSCs attenuated lung injury by improving the autophagy level via the PI3K/Akt signalling pathway. These findings provide further understanding of the mechanisms related to BM-MSCs and will help to develop new cell-based therapeutic strategies in lung injury. Less
The aim of this study was to investigate and characterize the efficacy and mechanism of action of asiaticoside in combination with rapamycin in the inhibition of in-stent... More
The aim of this study was to investigate and characterize the efficacy and mechanism of action of asiaticoside in combination with rapamycin in the inhibition of in-stent restenosis (ISR). The effects of asiaticoside combined with rapamycin on cell proliferation in vitro were evaluated by MTT assay. The mRNA expression was analyzed by quantitative polymerase chain reaction (qPCR). Enzyme-linked immunosorbent assay (ELISA) was used to confirm protein synthesis. The cell growth inhibition rate in the combination group was significantly higher compared with those in the asiaticoside and rapamycin groups for human aortic fibroblasts (HAFs; 63.50±3.83, 53.06±8.10 and 60.34±4.9%, respectively) and human aortic smooth muscle cells (HASMCs; 33.12±1.35, 26.21±7.59 and 28.27±4.92, respectively; P<0.05). However, for human coronary artery endothelial cells (HCAECs), the cell growth inhibition rates in the combination, asiaticoside and rapamycin groups were 11.09±1.17, 26.22±4.24 and 34.80±2.80%, respectively (P<0.05), as detected by MTT assay. The qPCR assay showed that in the combination group the level of von Willebrand factor (vWF) mRNA was downregulated, while platelet endothelial cell adhesion molecule (PECAM-1) and endothelial nitric oxide synthase (eNOS) mRNAs were upregulated in HCAECs compared with the rapamycin group (P<0.05). Transforming growth factor (TGF)-β1 and TIMP1 mRNAs were downregulated while Smad7 and matrix metalloproteinase 1 (MMP1) mRNAs were upregulated in HAFs compared with the rapamycin and AT groups (P<0.05). The ELISA showed that the type I collagen level was significantly reduced in HASMCs and HAFs (P<0.05). The data suggest that asiaticoside combined with rapamycin may be effective in the reduction of ISR. Keywords: in-stent restenosis, asiaticoside, rapamycin, Smad7 Less
Aims: High glucose promotes macrophage-derived foam cell formation involved in increased influx or reduced efflux of lipids. The aim of this study is to investigate the i... More
Aims: High glucose promotes macrophage-derived foam cell formation involved in increased influx or reduced efflux of lipids. The aim of this study is to investigate the influence of hyperglycaemia on foam cell transformation of vascular smooth muscle cells (VSMCs) and possible mechanisms contributing to these effects. Methods and results: The results showed that high glucose increased the expression of CD36, a regulator of lipid influx, and suppressed the expression and activity of the adenosine triphosphate-binding cassette (ABC) transporter ABCG1, a regulator of cholesterol efflux to high-density lipoprotein, in a dose- and time-dependent manner. However, cholesterol efflux to lipid-free apoAI was not impaired. VSMCs exposed to high glucose readily developed into lipid-loaded cells, as demonstrated by Oil Red O staining and cholesterol content analysis. In addition, high glucose-induced down-regulation of ABCG1 was reversed by nuclear factor-kappaB (NF-kappaB) inhibitors BAY 11-7085 and tosyl-phenylalanine chloromethyl ketone and by the antioxidant N-acetyl-L-cysteine (NAC). This reversal was accompanied by reduced cellular lipid content. Also, NAC and NF-kappaB inhibitors can effectively block the high glucose-induced activity of NF-kappaB binding to DNA and/or peroxide production. Conclusion: These results suggested that hyperglycaemia-induced foam cell formation in VSMCs was related to the imbalanced lipid flux by increasing CD36-mediated modified low-density lipoprotein uptake and reducing ABCG1-regulated cellular cholesterol efflux. Moreover, this effect was associated with increased oxidative stress and activated NF-kappaB pathway signalling. Less
In this paper, we investigate the effect and the possible mechanism of high glucose levels on the calcification of human aortic smooth muscle cells (HASMCs). HASMCs were ... More
In this paper, we investigate the effect and the possible mechanism of high glucose levels on the calcification of human aortic smooth muscle cells (HASMCs). HASMCs were divided into four groups: normal glucose group (NG), osmolality control group (OC), high glucose group (HG, HASMCs culture medium containing 30 mmol/L glucose), and high glucose plus recombinant human Noggin protein (bone morphogenetic protein-2 (BMP-2) antagonist) group (HN). The mRNA levels and the protein expressions of BMP-2 and core binding factor alpha-1 (Cbfα-1) were measured by real-time quantitative polymerase chain reaction (PCR) and Western blot. After induced by 10 mmol/L β-glycerol phosphoric acid, cells were harvested for assessments of alkaline phosphatase (ALP) activities at Days 1, 2, and 3, and intracellular calcium contents at Days 7 and 14, respectively. High glucose levels increased the mRNA levels and the protein expressions of BMP-2 and Cbfα-1 (P<0.05). The expression of Cbfα-1 was partially blocked by Noggin protein (P<0.05), while BMP-2 was not (P>0.05). After being induced by β-glycerol phosphoric acid, high glucose levels increased the ALP activity [(48.63±1.03) vs. (41.42±2.28) U/mg protein, Day 3; P<0.05] and the intracellular calcium content [(2.76±0.09) vs. (1.75±0.07) μmol/mg protein, Day 14; P<0.05] in a time-dependent manner when compared with the NG group, while the ALP activity could not be blocked by Noggin protein [(48.63±1.03) vs. (47.37±0.97) U/mg protein, Day 3; P>0.05]. These results show that high glucose levels can evoke the calcification of HASMCs by inducing osteoblastic trans-differentiation and intracellular calcium deposition via the BMP-2/Cbfα-1 pathway, which can be partially blocked by Noggin protein. Keywords: Bone morphogenetic protein (BMP), Core binding factor alpha-1 (Cbfα-1), Vascular smooth muscle cell, Noggin protein Less
Angiotensin II plays a critical role in hypertrophy of vascular smooth muscle cells, however, the molecular underpinnings remain unclear. The present study indicated that... More
Angiotensin II plays a critical role in hypertrophy of vascular smooth muscle cells, however, the molecular underpinnings remain unclear. The present study indicated that AT1/PKC/PKD pathway was able to regulate downstream ERK5, affecting pro-hypertrophic responses to Ang II. Ang II-stimulated phosphorylation of ERK5 in a time- and dose-dependent manner in human aortic smooth muscle cells (HASMCs). The pharmacological inhibitors for AT1 and PKCs significantly inhibited Ang II-induced ERK5 activation, suggesting the involvement of the AT1/PKC pathway. In particular, PKD was critical for Ang II-induced ERK5 activation since silencing PKD by siRNA markedly inhibited Ang II-induced ERK5 activation. Consequently, we found that Losartan, Gö 6983 and PKD siRNA significantly attenuated ERK5 activated translocation and hypertrophy of HASMCs by Ang II. Taken together, we demonstrated for the first time that Ang II activates ERK5 via the AT1/PKC/PKD pathway and revealed a critical role of ERK5 in Ang II-induced HASMCs hypertrophy. Less
Objectives: The goal of this study was to investigate the expression of early growth response-1 (Egr-1), a vascular pathogenic transcription factor, and its potential rel... More
Objectives: The goal of this study was to investigate the expression of early growth response-1 (Egr-1), a vascular pathogenic transcription factor, and its potential relationship with tissue factor (TF), a key player during the thrombus formation in the abdominal aortic aneurysm (AAA) wall. Background: Although intraluminal thrombus is a common finding in human AAA, the molecular mechanism of the thrombus formation has not been studied. Methods: During the elective AAA repair, specimens were taken from the thrombus-covered and thrombus-free portions of the aneurysmal wall in each of 16 patients with AAA and analyzed to assess the differential expression of Egr-1 and TF. The proinflammatory and prothrombogenic activities of Egr-1 in vasculature were evaluated in vitro and in vivo by overexpressing it using adenovirus. Results: The expression of both Egr-1 and TF was significantly increased in the thrombus-covered wall compared with the thrombus-free wall, in which their up-regulation in the thrombus-covered wall was strongly correlated with each other (p < 0.005, r = 0.717). Adenoviral overexpression of Egr-1 in human vascular smooth muscle and endothelial cells was found to up-regulate the expression of TF and inflammation-related genes. Moreover, Egr-1 overexpression in endothelial cells increased their adhesiveness to monocytes and also substantially promoted the intravascular thrombus formation in vivo, as shown in the inferior vena cava ligation experiment of the rat. Conclusions: The present study demonstrates the differential up-regulation of Egr-1 in the thrombus-covered wall of human AAA and also suggests its possible contribution to the thrombogenic and inflammatory pathogenesis in human AAA. Less
Human aortic endothelial (HAEC) and human coronary artery smooth muscle cell (HCASMC) responses on electrospun silk fibroin scaffolds were studied to evaluate potential f... More
Human aortic endothelial (HAEC) and human coronary artery smooth muscle cell (HCASMC) responses on electrospun silk fibroin scaffolds were studied to evaluate potential for vascular tissue engineering. Cell proliferation studies supported the utility of this biomaterial matrix by both HAECs and HCASMCs. Alignment and elongation of HCASMCs on random non-woven nanofibrous silk scaffolds was observed within 5 days after seeding based on SEM and confocal microscopy. Short cord-like structures formed from HAECs on the scaffolds by day 4, and a complex interconnecting network of capillary tubes with identifiable lumens was demonstrated by day 7. The preservation of cell phenotype on the silk fibroin scaffolds was confirmed by the presence of cell-specific markers, including CD146, VE-cadherin, PECAM-1 and vWF for HAECs, and SM-MHC2 and SM-actin for HCASMCs at both protein and transcription levels using immunocytochemistry and real-time RT-PCR, respectively. Formation of ECM was also demonstrated for the HCASMCs, based on the quantification of collagen type I expression at protein and transcription levels. The results indicate a favorable interaction between vascular cells and electrospun silk fibroin scaffolds. When these results are factored into the useful mechanical properties and slow degradability of this protein biomaterial matrix, potential utility in tissue-engineered blood vessels can be envisioned. Less
Inflammation is an important event in the development of vascular diseases such as hypertension, atherosclerosis, and restenosis. In addition, the stimulation of Toll-lik... More
Inflammation is an important event in the development of vascular diseases such as hypertension, atherosclerosis, and restenosis. In addition, the stimulation of Toll-like receptor 4 (TLR4) by lipopolysaccharide (LPS) induces the release of critical proinflammatory cytokines that activate potent immune responses. In this study, LPS was found to induce TLR4 expression and increased nitric oxide (NO) production by increasing the expression of inducible nitric oxide synthase (iNOS). Furthermore, LPS was found to induce interleukin (IL)-8 and vascular endothelial growth factor (VEGF) production, as well as intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) expression. Taken together, these results indicate that LPS induces inflammatory responses in HASMC. Moreover, NOS inhibitor (L-NAME) and anti-TLR 4mAb reduced the LPS-induced NO, IL-8 and VEGF production and ICAM-1 expression. Additionally, TLR4 expression was reduced by NOS inhibitor. Taken together, these results indicate that LPS-induced inflammatory responses are regulated by TLR4 expression and NO production. Less
Background and objectives: In asthma, airway smooth muscle cell (ASMC) hyperplasia plays an important role in airway remodelling. Increased expression of matrix metallopr... More
Background and objectives: In asthma, airway smooth muscle cell (ASMC) hyperplasia plays an important role in airway remodelling. Increased expression of matrix metalloproteinases-9 (MMP-9), a disintegrin and metalloprotease 33 (ADAM33) in ASMCs are also relevant to asthmatic airway remodelling. 1,25-dihydroxyvitamin D(3) (1,25-(OH)(2)D(3)) has potent antiproliferative properties in vitro in various cell types; however, its role in ASMCs is not well understood. This study investigated the effect of 1,25-(OH)(2)D(3) on passively sensitized human bronchial (airway) smooth muscle cell (HASMC) proliferation and MMP-9 and ADAM33 expressions. Methods: The effect of 1,25-(OH)(2)D(3) on cell proliferation was examined by 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium-bromide colorimetry assay; cell cycle analysis by flow cytometry; and immunocytochemical staining for proliferating cell nuclear antigen (PCNA). The expression of MMP-9 and ADAM33 in HASMCs was investigated by real-time quantitative PCR and Western Blot analysis. Results: 1,25-(OH)(2)D(3) effectively suppressed passively sensitized HASMC proliferation, proliferating cell nuclear antigen expression and G(1)/S transition in HASMCs passively sensitized with asthmatic serum. Further analysis showed that 1,25-(OH)(2)D(3) significantly down-regulated the expressions of protein for MMP-9 and ADAM33, as well as their mRNA levels in passively sensitized HASMCs. Conclusions: 1,25-(OH)(2)D(3) has direct inhibitory effects on passively sensitized HASMCs in vitro, including inhibition of cell proliferation and expression of MMP-9 and ADAM33, suggesting a possible beneficial role for 1,25-(OH)(2)D(3) in preventing and treating asthmatic airway remodelling. Less