人颈动脉粥样硬化斑块环氧化物酶-2及Ⅰ型前列腺素合成酶的表达

目的探讨环氧化物酶-2(cyclooxygenase type 2,COX-2)及Ⅰ型前列腺素合成酶(membrane associated prostaglandin E-1,mPGES-1)在人颈动脉粥样硬化斑块中的表达变化及作用机制。方法收集24例人颈动脉粥样硬化斑块标本和10例肠系膜动脉标本做对照组,应用免疫组织化学及逆转录PCR方法测定COX-2及mPGES-1mRNA表达水平,Western印记方法检测COX-2及mPGES-1的蛋白表达水平。比较不同程度动脉粥样硬化组织间COX-2、mPGES-1 mRNA表达水平及蛋白表达水平。结果颈动脉粥样硬化斑块组的免疫组织化学染色检测COX-2和mPGES-1呈阳性表达,斑块组COX-2 mRNA和mPGES-1 mRNA表达与对照组相比上调,差异有统计学意义(P<0.05);COX-2及mPGES-1 mRNA上调水平相关(P<0.05);颈动脉粥样硬化斑块的COX-2蛋白表达上调水平与对照组相比差异有统计学意义(P<0.05);颈动脉粥样硬化斑块COX-2、mPGES-1 mRNA及蛋白表达水平与病理损害程度有关,差异有统计学意义(P<0.05)。结论COX-2及mPGES-1基因表达水平上调可能是进展性动脉粥样硬化损害的关键因素。     

人颈动脉粥样硬化斑块环氧化物酶-2及I型前列腺素合成酶的表达

目的探讨环氧化物酶-2（cyclooxygenase type2，COX-2）及I型前列腺素合成酶（membrane associated prostaglandin E-1，mPGES-1）在人颈动脉粥样硬化斑块中的表达变化及作用机制。方法收集24例人颈动脉粥样硬化斑块标本和10例肠系膜动脉标本做对照组，应用免疫组织化学及逆转录PCR方法测定COX-2及mPGES-1mRNA表达水平，Western印记方法检测COX-2及mPGES-1的蛋白表达水平。比较不同程度动脉粥样硬化组织间COX-2、mPGES-1 mRNA表达水平及蛋白表达水平。结果颈动脉粥样硬化斑块组的免疫组织化学染色检测COX-2和mPGES-1呈阳性表达，斑块组COX-2 mRNA和mPGES-1 mRNA表达与对照组相比上调，差异有统计学意义（P〈0．05）；COX-2及mPGES-1 mRNA上调水平相关（P〈0．05）：颈动脉粥样硬化斑块的COX-2蛋白表达上调水平与对照组相比差异有统计学意义（P〈0．05）；颈动脉粥样硬化斑块COX-2、mPGES-1 mRNA及蛋白表达水平与病理损害程度有关，差异有统计学意义（P〈0．05）。结论COX-2及mPGES-1基因表达水平上调可能是进展性动脉粥样硬化损害的关键因素。     

Continuous ambulatory peritoneal dialysis patients show high prevalence of carotid artery calcification which is associated with a higher left ventricular mass index

This study examined intima-media thickness and arterial plaque occurrence in the carotid and brachial arteries in continuous ambulatory peritoneal dialysis (CAPD) patients. The study compared 25 CAPD patients with 25 normotensive age- and sex-matched controls. Intima-media thickness and presence of plaque in carotid and brachial artery were measured three times using high-resolution B-mode echocardiography. Left ventricular mass was calculated using the Penn Convection equation. Blood samples were obtained to assess levels of phosphorus, total calcium, serum albumin, C-reactive protein, and lipid profiles. Compared to the control group, CAPD patients had greater mean carotid and brachial intima-media thickness, and a higher proportion of subjects with calcified plaques. The left ventricular mass index was higher in CAPD patients with carotid artery calcified plaques compared to CAPD patients without carotid artery calcified plaques. CAPD patients with such plaque were significantly associated with diabetes mellitus, higher C-reactive protein levels and a lower 2-yr survival rate. The present study showed an high prevalence of carotid calcification in CAPD patients and those with such calcification had a greater incidence of diabetes mellitus, higher C-reactive protein levels and left ventricular mass index, and a lower survival rate.     

The impact of antimalarial agents on traditional and non-traditional subclinical atherosclerosis biomarkers in systemic lupus erythematosus: A systematic review and meta-analysis

ObjectiveCardiovascular (CV) morbidity is a well-established problem in systemic lupus erythematosus (SLE). Antimalarial (AM) therapy has been seen as a potential atheroprotective agent. The aim was to assess the impact of AM therapy on traditional and novel atherosclerosis (AT) biomarkers in patients with SLE.MethodsA search of MEDLINE, EMbase, and Cochrane library for studies evaluating the impact of AM on AT biomarkers in SLE was conducted. Data extraction included serum, functional and structural traditional and novel biomarkers. A narrative synthesis of the findings and a meta-analysis with random effects was conducted estimating mean differences (MD), OR, HR and 95% CIs.ResultsThe search strategy produced 148 articles, of which 64 were extracted for analysis. The MD in VLDL-cholesterol (?10.29, 95% CI -15.35, 5.24), triglycerides (?15.68, 95% CI -27.51, ?3.86), and diastolic BP (?3.42, 95% CI -5.62, ?1.23) differed significantly in patients on AM therapy compared with those without AM therapy. Patients on AM had a lower prevalence and incidence of diabetes mellitus than patients not on AM (HR: 0.39, 95% CI 0.17, 0.88). HCQ use was associated with lower blood pressure (BP) variability. Structural markers like carotid intima-media thickness (IMT), carotid plaque (CP) and coronary artery calcification (CAC) were not influenced by AM. For functional markers like endothelial and arterial stiffness the benefit was unclear. The GRADE approach showed a very low-to-low quality of evidence (QoE) per outcome.ConclusionsThere is some evidence on the associations between AM therapy and some AT markers. However, the data on which this conclusion was based was of low to very low evidence.     

Gene profiling of cathepsin K deficiency in atherogenesis: profibrotic but lipogenic

Recently, we showed that cathepsin K deficiency reduces atherosclerotic plaque progression, induces plaque fibrosis, but aggravates macrophage foam cell formation in the ApoE -/- mouse. To obtain more insight into the molecular mechanisms by which cathepsin K disruption evokes the observed phenotypic changes, we used microarray analysis for gene expression profiling of aortic arches of CatK -/-/ApoE -/- and ApoE -/- mice on a mouse oligo microarray. Out of 20 280 reporters, 444 were significantly differentially expressed (p-value of < 0.05, fold change of > or = 1.4 or < or = - 1.4, and intensity value of > 2.5 times background in at least one channel). Ingenuity Pathway Analysis and GenMAPP revealed upregulation of genes involved in lipid uptake, trafficking, and intracellular storage, including caveolin - 1, - 2, - 3 and CD36, and profibrotic genes involved in transforming growth factor beta (TGFbeta) signalling, including TGFbeta2, latent TGFbeta binding protein-1 (LTBP1), and secreted protein, acidic and rich in cysteine (SPARC), in CatK -/-/ApoE -/- mice. Differential gene expression was confirmed at the mRNA and protein levels. In vitro modified low density lipoprotein (LDL) uptake assays, using bone marrow derived macrophages preincubated with caveolae and scavenger receptor inhibitors, confirmed the importance of caveolins and CD36 in increasing modified LDL uptake in the absence of cathepsin K. In conclusion, we suggest that cathepsin K deficiency alters plaque phenotype not only by decreasing proteolytic activity, but also by stimulating TGFbeta signalling. Besides this profibrotic effect, cathepsin K deficiency has a lipogenic effect owing to increased lipid uptake mediated by CD36 and caveolins.     

Calcification Locates to Transglutaminases in Advanced Human Atherosclerotic Lesions

Transglutaminases play an important role in vascular smooth muscle cell-induced calcification in vitro. In this study, we determined whether these enzymes are also involved in human atherosclerotic calcification using nine carotid artery specimens obtained at endarterectomy. Sections of the carotid artery specimens were registered to micro-computed tomography images and stained for tissue-type transglutaminase, plasma transglutaminase factor XIIIA (FXIIIA), the N^ε(γ-glutamyl)lysine cross-link, and the macrophage marker CD68. Ex vivo micro-computed tomography revealed extensive calcification, which significantly correlated with the cross-link. FXIIIA was found to be the dominant transglutaminase, rather than tissue-type transglutaminase, although staining of both transglutaminases correlated with the cross-link. Staining for FXIIIA colocalized with CD68 at both the cellular and tissue level. In conclusion, areas of calcification locate to the presence and activity of transglutaminases in human atherosclerotic arteries. FXIIIA seems to be the dominant transglutaminase and may be derived from local macrophages. These results are consistent with the hypothesis that transglutaminases participate in the calcification process of human atherosclerotic arteries.Vascular calcification is considered a tightly regulated process of matrix deposition by osteoblast-like cells.¹ These cells may be derived from stem cells or differentiate from smooth muscle cells or pericytes. Recent work from Johnson et al² suggests a role for transglutaminases in the process of arterial calcification. On the basis of in vitro experiments on cultured healthy arterial segments and smooth muscle cells, these authors proposed a novel mechanism of arterial calcification, for which tissue-type transglutaminase (TG2) is central in the chondro-osseous differentiation and calcification of smooth muscle cells. Transglutaminases form a class of enzymes with pleiotropic function³ that consists of nine known members. Among these, TG2 is expressed in endothelial cells, smooth muscle cells, and monocytes/macrophages. The plasma transglutaminase, factor XIIIA (FXIIIA) is expressed in monocytes/macrophages.⁴ TG2 has been implicated in an animal model for atherosclerotic lesion formation,⁵ whereas both TG2 and FXIIIA are involved in vascular remodeling.^6,7 TG2 and FXIIIA are also involved in normal bone formation, where they act in concert to promote chondrocyte maturation.⁸ Although these data suggest an important role of transglutaminases in the development of atherosclerotic calcification, evidence of their role in human atherosclerotic lesion development is lacking. Therefore, we investigated the presence of transglutaminases, ie, TG2 and FXIIIA, the transglutaminase-induced cross-link and macrophages in human atherosclerotic carotid arteries. These markers were correlated to calcified areas that were detected ex vivo with micro-computed tomography (μCT) imaging.     

Identification of differential protein expression associated with development of unstable human carotid plaques

Rupture-prone unstable arterial plaques develop concomitantly with the appearance of intraplaque hemorrhage and tissue ulceration, in association with deregulation of smooth muscle cell mitogenesis and leakage of newly formed blood vessels. Using microarray technology, we have identified novel protein deregulation associated with unstable carotid plaque regions. Overexpression of proapoptotic proteins caspase-9 and TRAF4 was seen in endothelial cells and smooth muscle cells from unstable hemorrhagic and ulcerated plaque regions. Topoisomerase-II-alpha (TOPO-II-alpha), which is associated with DNA repair mechanisms, was also overexpressed by these cells. Cell signaling molecules c-src, G-protein-coupled receptor kinase-interacting protein (GIT1), and c-jun N-terminal kinase (JNK) were up-regulated in endothelial cells from the same areas, whereas an increase in expression of junctional adhesion molecule-1 (JAM-1) in blood vessels and infiltrating macrophages from inflammatory regions might form part of a leukocyte rolling response, increasing the plaque volume. Grb2-like adaptor protein (Gads), responsible for differentiation of monocytes into macrophages, was expressed by macrophages from unstable plaques, suggesting a potential mechanism through which increased scavenging could occur in rupture-prone areas. We conclude that modulation of novel cell signaling intermediates, such as those described here, could be useful in the therapy of angiogenesis and apoptosis, designed to reduce unstable plaque formation.     

Identification of epithelial-mesenchymal transition-related circRNA-miRNA-mRNA ceRNA regulatory network in breast cancer

BackgroundCircular RNAs (circRNAs) have attracted lots of attention in tumorigenesis and progression. However, circRNAs as crucial regulators in epithelial-mesenchymal transition have not been systematically identified in breast cancer. The purpose of our research was to investigate the circRNA network associated with epithelial-mesenchymal transition in breast cancer.MethodsExpression profiling data of circRNAs were identified by circRNA microarray in transfected ZEB1 and control breast cancer cells. The differentially expressed circRNAs, miRNAs, and mRNAs were determined via fold change filtering. The competing endogenous RNAs (ceRNAs) network was established on the foundation of the relationship between circular RNAs, miRNAs and mRNAs. The CytoHubba was used to determine the hub genes from the protein-protein interaction (PPI) regulatory network. The GEPIA database was used to observe the expression of the hub genes mRNA between breast cancer tissues and normal tissues. The HPA database was applied to investigate the expression of six hub genes at the protein level. Morever, we further used Kaplan–Meier plotter to perform survival analysis of these hub genes.ResultsThe top three up-regulated differential expressed circRNAs were identified by circRNA microarray. Following the Real-time PCR validation of the three circRNAs, two circRNAs (hsa_circRNA_002082 and hsa_circRNA_400031) were selected for further analysis. After the predicted target miRNA, ten circRNA-miRNA interactions including two circRNAs and ten miRNAs were determined. Furthermore, the Venn diagram was used to intersect the predicted target genes and the differentially expressed genes, and screened 174 overlapped genes. Subsequently, we constructed a PPI network, and selecting six hub genes, containing KIF4A, CENPF, OIP5, ZWINT, DEPDC1, BUB1B. The mRNA expression levels of the six hub genes were obviously up-regulated in breast cancer. The protein expression levels of KIF4A, CENPF, OIP5, and DEPDC1 were significantly increased in breast cancer tissues. Moreover, the survival analysis results revealed that high expression of the six hub genes were obviously correlated with poor prognosis of breast cancer patients.ConclusionsOur study constructed and analyzed a circRNA-associated ceRNA regulatory network and discovered that hsa_circRNA_002082 and hsa_circRNA_400031 may mechanism as ceRNAs to serve key roles in breast cancer epithelial-mesenchymal transition.     

Hemodynamic and ventilatory response to different levels of hypoxia and hypercapnia in carotid body-denervated rats

OBJECTIVE:

Chemoreceptors play an important role in the autonomic modulation of circulatory and ventilatory responses to changes in arterial O₂ and/or CO₂. However, studies evaluating hemodynamic responses to hypoxia and hypercapnia in rats have shown inconsistent results. Our aim was to evaluate hemodynamic and respiratory responses to different levels of hypoxia and hypercapnia in conscious intact or carotid body-denervated rats.

METHODS:

Male Wistar rats were submitted to bilateral ligature of carotid body arteries (or sham-operation) and received catheters into the left femoral artery and vein. After two days, each animal was placed into a plethysmographic chamber and, after baseline measurements of respiratory parameters and arterial pressure, each animal was subjected to three levels of hypoxia (15, 10 and 6% O₂) and hypercapnia (10% CO₂).

RESULTS:

The results indicated that 15% O₂ decreased the mean arterial pressure and increased the heart rate (HR) in both intact (n = 8) and carotid body-denervated (n = 7) rats. In contrast, 10% O₂ did not change the mean arterial pressure but still increased the HR in intact rats, and it decreased the mean arterial pressure and increased the heart rate in carotid body-denervated rats. Furthermore, 6% O₂ increased the mean arterial pressure and decreased the HR in intact rats, but it decreased the mean arterial pressure and did not change the HR in carotid body-denervated rats. The 3 levels of hypoxia increased pulmonary ventilation in both groups, with attenuated responses in carotid body-denervated rats. Hypercapnia with 10% CO₂ increased the mean arterial pressure and decreased HR similarly in both groups. Hypercapnia also increased pulmonary ventilation in both groups to the same extent.

CONCLUSION:

This study demonstrates that the hemodynamic and ventilatory responses varied according to the level of hypoxia. Nevertheless, the hemodynamic and ventilatory responses to hypercapnia did not depend on the activation of the peripheral carotid chemoreceptors.     

Inhibition of NLRP3 inflammasome: a new protective mechanism of cinnamaldehyde in endotoxin poisoning of mice

Context: Cinnamaldehyde (CA) has a protective effect in endotoxin poisoning of mice, but there is no direct evidence for the protective effect of CA through inhibition of NLRP3 inflammasome activation in endotoxin poisoning of mice.

Objective: We aimed to investigate the protective mechanism of CA in endotoxin poisoned mice through NLRP3 inflammasome.

Materials and methods: First, we evaluated the anti-inflammatory effect of CA in phorbol-12-myristate acetate–differentiated THP-1 cells through the NLRP3 inflammasome. Second, in a mouse model of lipopolysaccharide (LPS)-induced endotoxin poisoning, CA was administrated for 5 d (once a day) before the 15?mg/kg LPS challenge. Then, the levels of IL-1β in serum were measured, and the effect of CA on the NLRP3 inflammasome activation and the expression of cathepsin B and P2X7R proteins in lung were explored.

Results: In vitro, CA decreased the levels of p20, pro-IL-1β and IL-1β in cell culture supernatants, as well as the expression of NLRP3 and IL-1β mRNA in cells. In vivo, CA decreased IL-1β production in serum. Furthermore, CA suppressed LPS-induced NLRP3, p20, Pro-IL-1β, P2X7 receptor (P2X7R) and cathepsin B protein expression in lung, as well as the expression of NLRP3 and IL-1β mRNA.

Conclusions: CA has a protective effect in the endotoxin poisoned mice through the inhibition of NLRP3 inflammasome activation. Furthermore, CA suppresses the NLRP3 inflammasome activation by inhibiting the expression of cathepsin B and P2X7R protein expression. CA can be considered as a potential therapeutic candidate for diseases involved in endotoxin poisoning such as sepsis.     

The association of breast arterial calcification and metabolic syndrome

OBJECTIVES:We investigated the relationship between metabolic syndrome and breast arterial calcification detected via mammography in a cohort of postmenopausal subjects.METHODS:Among 837 patients referred to our radiology department for mammographic screening, 310 postmenopausal females (105 patients with and 205 patients without breast arterial calcification) aged 40 to 73 (mean 55.9±8.4) years were included in this study. The groups were compared with respect to clinical characteristics and metabolic syndrome criteria. Univariate and multivariate analyses identified the factors related to breast arterial calcification.RESULTS:Age, postmenopausal duration and the frequencies of diabetes mellitus, hypertension and metabolic syndrome were significantly higher in the subjects with breast arterial calcification than in those without (p<0.05). Multivariate analysis indicated that age (OR = 1.3, 95% CI = 1.1–1.6, p = 0.001) and metabolic syndrome (OR = 4.0, 95% CI = 1.5−10.4, p = 0.005) were independent predictors of breast arterial calcification detected via mammography. The independent predictors among the features of metabolic syndrome were low levels of high-density lipoproteins (OR = 8.1, 95% CI = 1.0−64.0, p = 0.047) and high blood pressure (OR = 8.7, 95% CI = 1.5−49.7, p = 0.014).CONCLUSIONS:The likelihood of mammographic detection of breast arterial calcification increases with age and in the presence of hypertension or metabolic syndrome. For patients undergoing screening mammography who present with breast arterial calcification, the possibility of metabolic syndrome should be considered. These patients should be informed of their cardiovascular risk factors and counseled on appropriate lifestyle changes.     

Coronary atherosclerotic lesions in human immunodeficiency virus–infected patients: a histopathologic study

BackgroundStudies suggest human immunodeficiency virus–positive (HIV+) patients have an increased risk of coronary artery disease (CAD), yet little is known about the histopathology, severity, or distribution of lesions.MethodsThe coronary arteries of 66 deceased AIDS patients and 19 HIV controls (age <55) were dissected and graded for percent luminal stenosis by intimal lesions, percent of intima involved with lipid, and extent of intimal calcification on a scale of 0 to 3. Medical histories, antiretroviral therapies, and CAD risk factors were reviewed.ResultsHIV+ patients were older than controls (P=.06), and more were male (P=.02). Thirty-five percent of HIV+ patients had stenosis ≥75% of at least one artery. Compared to controls, HIV+ patients had three times greater odds of stenosis ≥75%, controlling for age and sex (one-sided P=.03). Older age and male sex were also risk factors (one-sided P<.001). HIV seropositivity was associated with increased plaque lipid content (one-sided P=.02) and calcification (one-sided P=.08). Duration of HIV infection, antiretroviral therapy, and immune status did not predict severe disease in multivariate analyses. Previously unreported patterns of dystrophic calcification were observed in HIV+ patients and older controls.ConclusionsYoung to middle-aged patients dying from advanced AIDS have atherosclerotic CAD that may result in luminal narrowing, heavy calcification, and high plaque lipid content. The pattern of disease, location of lesions, and plaque composition are typical of atherosclerosis in HIV-negative patients. No relationship between antiretroviral therapies and atherosclerosis was seen in this small study of heavily treated patients.     

Adventitial lymphocytic inflammation in human coronary arteries with intimal atherosclerosis

BackgroundThe relationship between adventitial inflammation, plaque type, and culprit plaque morphology in the epicardial arterial circulation has not been studied in detail.MethodsWe studied semiserial sections of coronary arteries at autopsy from patients dying with severe coronary disease, 81 men (age 50±12 years) and 13 women (age 52±13 years). Lesions were classified at 3- to 5-mm segments according to modified AHA criteria. Adventitial lymphocyte aggregates were assessed at every 5-mm interval and graded semiquantitatively. Macrophage density in the adventitial fat and intima was assessed with anti-CD68 staining.ResultsAdventitial lymphocytic inflammation increased with percent stenosis (P<.0001) and not calcification (P>.2). Hemorrhage into late core, rupture, erosion, and thin caps all had greater adventitial lymphocytic inflammation independent of percent stenosis (P<.0001). Peri-adventitial adipose macrophage density was increased in plaques with atheromas (206±22 mm² vs. 121±15 mm² in fibrous plaques; P=.02) and correlated positively with adventitial lymphocytes (P<.0001) and intimal macrophage content (P<.0001).ConclusionsFeatures associated with plaque instability are associated with significantly greater degrees of adventitial lymphocytic inflammation, both as lymphocyte aggregates and as adipocyte-derived macrophages. Further study is required to determine the nature of the association between intimal and adventitial lymphocytic inflammation.     

基因芯片筛选Bardct-Bicdl综合征患者外周血差异表达基因

目的 采用基因表达谱芯片研究Bardet-Biedl综合征(Bardet-Biedl syndrome,BBS)患者外周血单个核细胞差异基因表达谱.方法 抽取3例BBS先证者及4名年龄、性别匹配的健康对照者静脉血,分离外周血单个核细胞,用Trizol一步法提取总RNA并进行扩增和标记,然后与Affymetrix U133 Plus 2.0芯片进行杂交,扫描芯片并将图像信号转化为数字信号,GCOS1.4软件读取、处理数据.将患者与正常对照基因表达谱进行比较,最后以表达差异≥2倍(P＜0.05)为标准来确定差异表达基因.结果 BBS患者与正常对照相比,有30个基因表达有显著差异,包括15个上调基因及15个下调基因.通过GO分析,有12个基因与信号传导及细胞周期有关.结论 筛选到的差异基因与纤毛的功能或结构相关性及在BBS发生及发展中的作用有待研究.     

Inflammatory Bone Loss in Experimental Periodontitis Induced by Aggregatibacter actinomycetemcomitans in Interleukin-1 Receptor Antagonist Knockout Mice

The interleukin-1 receptor antagonist (IL-1Ra) binds to IL-1 receptors and inhibits IL-1 activity. However, it is not clear whether IL-1Ra plays a protective role in periodontal disease. This study was undertaken to compare experimental periodontitis induced by Aggregatibacter actinomycetemcomitans in IL-1Ra knockout (KO) mice and wild-type (WT) mice. Computed tomography (CT) analysis and hematoxylin-and-eosin (H&E) and tartrate-resistant acid phosphatase (TRAP) staining were performed. In addition, osteoblasts were isolated; the mRNA expression of relevant genes was assessed by real-time quantitative PCR (qPCR); and calcification was detected by Alizarin Red staining. Infected IL-1Ra KO mice exhibited elevated (P, <0.05) levels of antibody against A. actinomycetemcomitans, bone loss in furcation areas, and alveolar fenestrations. Moreover, protein for tumor necrosis factor alpha (TNF-α) and IL-6, mRNA for macrophage colony-stimulating factor (M-CSF), and receptor activator of NF-κB ligand (RANKL) in IL-1Ra KO mouse osteoblasts stimulated with A. actinomycetemcomitans were increased (P, <0.05) compared to in WT mice. Alkaline phosphatase (ALP), bone sialoprotein (BSP), osteocalcin (OCN)/bone gla protein (BGP), and runt-related gene 2 (Runx2) mRNA levels were decreased (P, <0.05). IL-1α mRNA expression was increased, and calcification was not observed, in IL-1 Ra KO mouse osteoblasts. In brief, IL-1Ra deficiency promoted the expression of inflammatory cytokines beyond IL-1 and altered the expression of genes involved in bone resorption in A. actinomycetemcomitans-infected osteoblasts. Alterations consistent with rapid bone loss in infected IL-Ra KO mice were also observed for genes expressed in bone formation and calcification. In short, these data suggest that IL-1Ra may serve as a potential therapeutic drug for periodontal disease.     

Human Serine Protease HTRA1 Positively Regulates Osteogenesis of Human Bone Marrow-derived Mesenchymal Stem Cells and Mineralization of Differentiating Bone-forming Cells Through the Modulation of Extracellular Matrix Protein

Mammalian high-temperature requirement serine protease A1 (HTRA1) is a secreted member of the trypsin family of serine proteases which can degrade a variety of bone matrix proteins and as such has been implicated in musculoskeletal development. In this study, we have investigated the role of HTRA1 in mesenchymal stem cell (MSC) osteogenesis and suggest a potential mechanism through which it controls matrix mineralization by differentiating bone-forming cells. Osteogenic induction resulted in a significant elevation in the expression and secretion of HTRA1 in MSCs isolated from human bone marrow-derived MSCs (hBMSCs), mouse adipose-derived stromal cells (mASCs), and mouse embryonic stem cells. Recombinant HTRA1 enhanced the osteogenesis of hBMSCs as evidenced by significant changes in several osteogenic markers including integrin-binding sialoprotein (IBSP), bone morphogenetic protein 5 (BMP5), and sclerostin, and promoted matrix mineralization in differentiating bone-forming osteoblasts. These stimulatory effects were not observed with proteolytically inactive HTRA1 and were abolished by small interfering RNA against HTRA1. Moreover, loss of HTRA1 function resulted in enhanced adipogenesis of hBMSCs. HTRA1 Immunofluorescence studies showed colocalization of HTRA1 with IBSP protein in osteogenic mASC spheroid cultures and was confirmed as being a newly identified HTRA1 substrate in cell cultures and in proteolytic enzyme assays. A role for HTRA1 in bone regeneration in vivo was also alluded to in bone fracture repair studies where HTRA1 was found localized predominantly to areas of new bone formation in association with IBSP. These data therefore implicate HTRA1 as having a central role in osteogenesis through modification of proteins within the extracellular matrix. STEM Cells2012;30:2271-2282.