Effect of CTRP3 on activation of adventitial fibroblasts induced by TGF-β1 from rat aorta in vitro

CTRP3, discovered as novel adipokines, is a member of the C1q tumor necrosis factor (TNF) related protein (CTRP) super-family. CTRP3 is found to function as adipokines that display diverse biological activities in metabolic and cardiovascular diseases. Recent study demonstrated that CTRP3 was protective against pathological cardiac remodeling in mice. Nevertheless, the effect of CTRP3 on vascular remodeling remains undefined. Our present study aimed to explore the effects of adipokine CTRP3 on the activation of adventitial fibroblasts (AFs) induced by TGF-β1. Immunofluorescent staining, real-time PCR and Western blot were conducted to evaluate the expression of α-smooth muscle-actin (α-SMA) and collagen I. The expression of CTGF was evaluated by enzymelinked immunosorbent assay (ELISA), while the proliferation and migration of adventitial fibroblasts were detected by using cell counting kit-8 (CCK-8) assay and Transwell technique, respectively. Functional analysis showed that CTRP3 inhibited TGF-β1 inducing AFs phenotypic conversion, collagen synthesis, proliferation and migration. The secretion of CTGF was also inhibited by CTRP3. Our findings suggest that CTRP3 may be beneficial to the prevention of cardiovascular diseases and provide a promising therapeutic strategy to attenuate vascular remodeling.     

Hemocoagulase atrox reduces vascular modeling in rabbit carotid artery adventitia

Objective: This study aimed to compare the effects of hemocoagulase atrox and cauterization hemostasis on intimal hyperplasia and explore the effect of hemocoagulase atrox on vascular modeling in rabbit carotid artery adventitia. Methods: A total of 27 rabbits were randomly divided into 3 groups (0d, 14d, 28d). They were anaesthetized using an intramuscular injection of phenobarbital sodium (1 ml/kg). The left and right common carotid arteries were exposed and capillary hemorrhaged after blunt dissection of the adventitia layers of common carotid arteries. Nine rabbits in each group were again randomly divided into 3 groups, in which animals were respectively treated with hemocoagulase (2 U/ml), cauterization (power = 40 w) and saline (as control). Groups of animals were euthanized at 0, 14 and 28 days after surgery. The samples were equally divided in the middle of the adventitia removal section to obtain equal parts for histologic, immunohistochemical and molecular biologic analysis. The vascular repair after adventitial stripping was observed by HE staining, Masson staining and transmission electron microscopy. The expression of carotid MCP-1, PCNA, TGF-β1, α-SMA and VEGF were measured at different time points by RT-PCR and immunohistochemical staining. Results: HE staining and Masson staining showed that hemocoagulase atrox had a significantly stronger effect on reducing intimal hyperplasia than the cauterization after 14 and 28 days. The results of RT-PCR showed that the expression of MCP-1, TGF-β1, α-SMA and VEGF in hemocoagulase atrox-treated animals were lower than that of cauterization-treated animals. Conclusion: Our results suggested that hemocoagulase atrox as a topical hemostatic is safety and efficiently and it can accelerate adventitia restoration and decrease intimal proliferation.     

Effect of angiotensin-(1-7) and angiotensin II on the proliferation and activation of human endometrial stromal cells in vitro

Recent studies have shown that angiotensin II (Ang II) or angiotensin-(1-7) [Ang-(1-7)] has effect on the proliferation and activation of a variety of cells, however, the exact mechanisms that the role of Ang II or Ang-(1-7) in human endometrial stromal cell (ESCs) remains elusive. Here we demonstrated that Ang II could promote proliferation and activation of ESCs, up-regulated the expression of a-SMA, TGF-β1 and IGF-I, increased the secretion of extracellular matrix [Type I collagen (Col I) and fibronectin (FN)] of ESCs; Ang-(1-7) could inhibit Ang II induced the proliferation and activation of ESCs, down-regulated the expression of a-SMA, TGF-β1 and IGF-I, decreased the secretion of extracellular matrix (Col I and FN) of ESCs. These findings suggest that Ang-(1-7) can inhibits Ang II induced the proliferation of ESCs, Ang-(1-7) can inhibits the Ang II induced activation of ESCs and decreases secretion of Col I and FN by suppressing TGF-β1 and IGF-I expression.     

Lipopolysaccharide activated TLR4/NF-κB signaling pathway of fibroblasts from uterine fibroids

Uterine fibroids (UF) are the most common benign tumor of the female reproductive tract. The aim of this study was to explore the role of lipopolysaccharide (LPS)-induced activation of TLR4/NF-κB signaling pathway on stromal fibroblasts in the pathogenesis of UF. Here, TLR4/NF-κB signaling pathway was more activated in UF, and UF cells (UFC) and UF derived fibroblasts (TAF) than in smooth muscle tissues, smooth muscle cell (SMC) and myometrial fibroblasts (fib) respectively. After lipopolysaccharide (LPS) stimulation, the activity of fib was enhanced, characterized by the increased expression of fibroblast activation protein (FAP), and increased secretion of collagen I and transforming growth factor-β (TGF-β). Moreover, TLR4 inhibitor (VIPER) and siTLR4 can represses LPS-activated fibroblasts and TLR4/NF-κB signaling transduction pathways in fib and UFC cells. Co-cultured with LPS-activated fibroblast enhanced fibroblast activation and TLR4/NF-κB signaling. In conclusion, LPS treatment activated TLR4/NF-κB signaling pathway on fibroblasts, which may involve in the development of UF. Our study indicated reproductive tract infection may be associated with fibroid pathogenesis through TLR4/NF-κB signaling. Targeting NF-κB with inhibitors may hold promises of treating uterine fibroid.     

Nuclear factor-κB mediates the phenotype switching of airway smooth muscle cells in a murine asthma model

Airway smooth muscle cells (ASMCs) phenotype modulation, characterized by reversible switching between contractile and proliferative phenotypes, is considered to contribute to airway proliferative diseases such as allergic asthma. Nuclear Factor-κB (NF-κB) has been reported as a key regulator for the occurrence and development of asthma. However, little is known regarding its role in ASM cell phenotypic modulation. To elucidate the role of NF-κB in regulating ASM cells phenotypic modulation, we investigated the effects of NF-κB on ASM cells contractile marker protein expression, and its impact on proliferation and apoptosis. We found that chronic asthma increased the activation of NF-κB in the primary murine ASM cells with a concomitant marked decrease in the expression of contractile phenotypic marker protein including smooth muscle alpha-actin (α-SMA). Additionally, we used the normal ASM cells under different processing to build the phenotype switching when we found the activation of NF-κB. Meanwhile, the expression of α-SMA in asthma was significantly increased by the NF-κB blocker. NF-κB blocker also suppressed asthma mouse ASM cell proliferation and promoted apoptosis. These findings highlight a novel role for the NF-κB in murine ASM cell phenotypic modulation and provide a potential target for therapeutic intervention for asthma.     

Molecular biological characteristics of the recruitment of hematopoietic stem cells from bone marrow niche in chronic myeloid leukemia

Chronic myeloid leukemia (CML) can be contextualized as a disease of unregulated self-renewal of stem cells which exist in a quiescent state and are instructed to differentiate and mobilize to circulation under pathologic circumstances leading to tumor invasion and metastasis. Here we found that matrix metalloproteinase-9 (MMP-9), induced by TGF-β1, upregulated s-KitL and s-ICAM-1, permitting the transfer of c-kit⁺ hematopoietic stem cells (HSCs) from the quiescent to proliferative niche in CML. Further study showed that this MMP-9 production was raised by CML specific BCR/ABL⁺ oncogene mediated TGF-β1. Besides, phosphatidylinositol-3 kinase (PI3K)/Akt/nuclear factor (NF)-κB signaling pathway was evidenced to govern this stem cell recruitment in CML pathogenesis. Overall, our observations defined a novel critical role for TGF-β1 induced PI3K/Akt/NF-κB signaling pathway in the recruitment of the malignant cells in CML by releasing s-KitL and s-ICAM-1 and this was through a distinct PI3K/Akt/NF-κB signaling pathway.     

Berberine regulates proliferation,collagen synthesis and cytokine secretion of cardiac fibroblasts via AMPK-mTOR-p70S6K signaling pathway

Objective: The traditional Chinese medicinal berberine has long been used to treat cardiovascular diseases; however, the mechanism underlying its effects remains unclear. Here, this study would to investigate the effects of berberine on proliferation, collagen synthesis and cytokine secretion of cardiac fibroblasts. Methods: We assessed proliferation, collagen synthesis and cytokine secretion in cardiac fibroblasts subjected to angiotensin II (Ang II) subsequent to the consumption of berberine or a control treatment. And then we detected the role of AMPK/mTOR signaling pathway in berberine treatment of cardiac fibroblasts. Results: In the present study, the cellular behaviors of cardiac fibroblasts induced by Ang II were significantly activated including proliferation, transformation into myofibroblasts and collagen synthesis. Additionally, the ability of cytokine secretion was enhanced obviously. It was demonstrated that treatment of cardiac fibroblasts with berberine resulted in deceased proliferation, and attenuated fibroblast α-smooth muscle actin expression and collagen synthesis. And the protein secretion of TGFβ1 was inhibited; however, the protein secretion of IL-10 was increased in cardiac fibroblasts with berberine treatment. Mechanistically, the phosphorylation level of AMPK was increased; and the phosphorylation levels of mTOR and p70S6K were decreased in berberine treatment group. Conclusion: These results illustrated that the protective effects of berberine on cellular behaviors of cardiac fibroblasts were at least in part due to activate AMPK signaling pathway and downregulate mTOR/p70S6K signaling pathway. Berberine might become a new strategy for treating cardiac fibrosis in the future.     

Effects of NF-κB and hypoxia on the biological behavior of Y79 retinoblastoma cells

We aimed to investigate the influence of nuclear factor-κB (NF-κB) on the biological behavior of Y79 retinoblastoma cells exposed to hypoxia and its possible mechanism. The cells were administrated with hypoxia, and/or 5 μM pyrrolidine dithiocarbamate (PDTC) (a selective NF-κB inhibitor) to inhibit the NF-κB activity, expressions of NF-κB was measured by western blot, and the translocation of NF-κB was detected. To examine the proliferation of Y79 cells, MTT assay was applied. Transwell assay was used to detect the invasion and migration ability of cells. The expressions of molecules involved in invasion was analyzed including HIF-1α, MMP-2, 9, and VEGF. We found that hypoxia significantly activated NF-κB activity. While once the NF-κB was inhibited, the proliferation, invasion and migration ability of Y79 cells were also blocked. Interestingly, the expressions of invasion-involved molecules elevated by hypoxia induction were also decreased when NF-κB was inhibited. Hypoxia could significantly change the adhesive and invasive ability of Y79 retinoblastoma cells, NF-κB signal might be one of the main mediators for these hypoxia induced cell changes of biological behavior via downregulation of HIF-1α and the invasion related molecules, and the mechanism still needs further investigation.     

血管紧张素Ⅱ对血管外膜成纤维细胞亚群转化的影响

目的:探讨血管紧张素Ⅱ(Ang Ⅱ)对大鼠胸主动脉血管外膜成纤维细胞亚群转化的影响。方法:采用克隆环法进行血管外膜成纤维细胞的单克隆培养,逆转录聚合酶链反应(RT-PCR)和免疫荧光染色方法鉴定细胞纯度;随机分为对照组和Ang Ⅱ(10~1 000 nmol/L)组,采用荧光定量聚合酶链式反应(FQ-PCR)、免疫荧光染色和Western blot法检测α-平滑肌肌动蛋白(α-SMA)的表达情况。结果:克隆环法获得血管外膜成纤维细胞2个亚群:圆形细胞亚群和纺锤形细胞亚群。自分型后,从第3代至第8代,纺锤形细胞亚群的α-SMA表达量有减少趋势,而圆形细胞亚群的α-SMA表达量显著增多。在Ang Ⅱ诱导下,纺锤形细胞亚群和圆形细胞亚群的α-SMA表达量均增多,且圆形细胞亚群随Ang Ⅱ浓度(10~1 000 nmol/L)的增加,α-SMA的表达量显著增多(P0.01)。Western blot实验结果显示,Ang Ⅱ能刺激圆形细胞亚群更多地转化为肌成纤维细胞。结论:Ang Ⅱ能不同程度地影响外膜成纤维细胞亚群的分化能力,进一步揭示出2个细胞亚群在血管重构过程中扮演不同角色。     

Transforming growth factor-beta regulates in vitro heart valve repair by activated valve interstitial cells

The regulation of valve interstitial cell (VIC) function in response to tissue injury and valve disease is not well understood. Because transforming growth factor-β (TGF-β) has been implicated in tissue repair, we tested the hypothesis that TGF-β is a regulator of VIC activation and associated cell responses that occur during early repair processes. We used a well-characterized wound model that was created by mechanical denudation of a confluent VIC monolayer to study activation and repair 24 hours after wounding. VIC activation was demonstrated by immunofluorescent localization of α-smooth muscle actin (α-SMA), and α-SMA mRNA levels were quantified by real-time polymerase chain reaction. Proliferation and apoptosis were quantified by bromodeoxyuridine staining and terminal deoxynucleotidyl transferase dUTP nick end labeling, respectively. Repair was quantified by measuring VIC extension into the wound, and TGF-β expression was shown by immunofluorescent localization of intracellular TGF-β. Compared with nonwounded monolayers, VICs at the wound edge showed α-SMA staining, increased α-SMA mRNA content, elongation into the wound with stress fibers, proliferation, and apoptosis. VICs at the wound edge also showed increased TGF-β and pSmad2/3 staining with co-expression of α-SMA. Addition of TGF-β neutralizing antibody to the wound decreased VIC activation, α-SMA mRNA content, proliferation, apoptosis, wound closure rate, and stress fibers. Conversely, exogenous addition of TGF-β to the wound increased VIC activation, proliferation, wound closure rate, and stress fibers. Thus, wounding activates VICs, and TGF-β signaling modulates VIC response to injury.     

Prolonged NF-κB Activation by a Macrophage Inhibitory Cytokine 1-Linked Signal in Enteropathogenic Escherichia coli-Infected Epithelial Cells

Intestinal epithelial activation of nuclear factor kappa B (NF-κB) exerts both detrimental and beneficial functions in response to various luminal insults, including ones associated with mucosa-associated pathogens. Gastrointestinal infection with enteropathogenic Escherichia coli (EPEC) causes severe injuries in epithelial integrity and leads to watery diarrhea. The present study was conducted to investigate the prolonged epithelial responses to persistent EPEC infection via NF-κB activation. EPEC infection led to sustained activation of NF-κB signal in mouse intestinal epithelial cells in vivo and in vitro, which was positively associated with a type III secretion system, whereas early NF-κB is regulated. Moreover, prolonged NF-κB activation was found to be a part of macrophage inhibitory cytokine 1 (MIC-1)-mediated signaling activation, a novel link between NF-κB signaling and infection-associated epithelial stress. EPEC infection induced gene expression of MIC-1, a member of the transforming growth factor β (TGF-β) superfamily, which then activated TGF-β-activated kinase 1 and consequently led to NF-κB activation. Functionally, both EPEC-induced MIC-1 and NF-κB signaling mediated epithelial survival by enhancing the expression of cyclin D1, a target of NF-κB. In summary, the results of the present study suggest that MIC-1 serves as a mediator of prolonged NF-κB activation, which is critical in maintaining gut epithelial integrity in response to infection-induced injuries.     

Knockdown of elF3a inhibits collagen synthesis in renal fibroblasts via Inhibition of transforming growth factor-β1/Smad signaling pathway

Renal fibrosis is characterized by an exacerbated accumulation of deposition of the extracellular matrix (ECM). The eukaryotic translation initiation factor (eIF) 3a is the largest subunit of the eIF3 complex and has been involved in pulmonary fibrosis. However, the role of eIF3a in rental fibrosis is still unclear. Therefore, in this study, we investigated the role of eIF3a in rental fibrosis and explored the underlying mechanism. Our study found that eIF3a was up-regulated in renal fibrotic tissues and transforming growth factor (TGF)-β1-treated HK-2 cells. In addition, knockdown of eIF3a significantly inhibited TGF-β1-induced expression levels of α-smooth muscle actin (α-SMA) and collagen I. Furthermore, knockdown of eIF3a attenuated TGF-β1-induced Smad3 activation in HK-2 cells. Taken together, these results suggest that knockdown of eIF3a inhibits collagen synthesis in renal fibroblasts via inhibition of TGF-β1/Smad signaling pathway, and eIF3a may be a potential molecular target for the treatment of renal fibrosis.     

Mechanism of IFN-γ in regulating OPN/Th17 pathway during vascular collagen remodeling of hypertension induced by ANG II

More and more researches show that hypertensive vascular remodeling is closely related to the imbalance of immune system in recent years. IFN-γ is natural protein with the function of immune regulation and has resistance effect on vascular remodeling. However, the mechanism of IFN-γ is to be defined. This paper is to explore the mechanism of IFN-γ in regulating OPN/Th17 pathway. In this research, animal models of vascular collagen remodeling were established by inducing hypertensive mice with ANG II. There was no statistical significance when the systolic blood pressures and the percentages of wall thickness/lumen diameter in both groups of WT + AngII + IFN-γ and WT + PBS were compared (P=0.219>0.05, P=0.118>0.05). The concentration of serum precollagen-type I and III and their ratio in WT + AngII + IFN-γ group were decreased after the IFN-γ being given (P<0.01). Expression of OPN within tissue in WT + Ang II group was relatively high, but lowered after treated by IFN-γ. Th17 cell ratio was decreased in WT + AngII + IFN-γ group (P<0.01). Expressions of RORα and RORγt mRNA within Th17 cell were decreased (P<0.01). The content of IL-23 in WT + AngII + IFN-γ group was increased, while IL-10 and TGF-β decreased. It has proved that IFN-γ can regulate the hypertensive vascular collagen remodeling induced by ANG II, lower the systolic pressure and reduce the pathological damage of vascular collagen remodeling and the collagen synthesis. The mechanism may that the differentiation of Th17 is inhibited by suppressing the OPN expression and regulating the secretion of inflammatory cytokines.     

血管成形术后血管外膜α-SMA、PCNA和OPN表达变化及意义

目的探讨大鼠胸主动脉血管成形术后血管平滑肌肌动蛋白(α-SMA)、增殖细胞核抗原(PCNA)和骨桥蛋白(OPN)表达的变化与血管外膜增殖的关系。方法6周龄健康、清洁纯系雄性SD(Sprague-Dawley)大鼠32只,体质量为(200±20)g;随机将其分为实验组和对照组,实验组大鼠用6 F人冠状动脉快速交换球囊扩张及剥脱胸腹主动脉内膜,对照组大鼠行胸腹主动脉假手术处理,术后第2周取胸主动脉,进行α-SMA、PCNA及OPN免疫组织化学检查;第6周取胸主动脉做组织形态学检查,并进行对比分析。结果对照组胸主动脉见α-SMA外膜和内膜极少量表达及中膜均匀表达;PCNA外膜和内膜极微量表达及外膜OPN阳性表达。实验组胸主动脉外膜和新生内膜α-SMA、PCNA及OPN阳性表达较对照组明显增强,而中膜α-SMA表达明显减弱。实验组胸主动脉外膜厚度和细胞数量及细胞增殖指数较对照组明显增加(P<0.05)。结论血管成形术后,血管外膜成纤维细胞被激活、增殖,向肌成纤维细胞表型转变,外膜OPN表达增多,外膜增厚,参与血管收缩性重塑。     

Mast cell chymase in keloid induces profibrotic response via transforming growth factor-β1/Smad activation in keloid fibroblasts

This study was to examine whether mast cell chymase exists in human keloids and exerts its profibrotic effect via transforming growth factor-β₁/Smad signaling pathway. The number of mast cells and the expression levels of chymase in keloids and normal skin were examined by immunohistochemistry assays. The mRNA expression and activity changes of chymase in keloids and normal skin were determined by real-time quantitative PCR and radioimmunoassay. After keloid fibroblasts were treated with different concentrations of chymase (0, 15, 30, 60, and 120 ng/mL) for various time periods, the proliferation of keloid fibroblasts, collagen synthesis, mRNA and protein expression of TGF-β₁, and the protein expression of phosphorylated Smad2/3, Smad2/3 and Smad7 were investigated using MTT assay, ELISA and Western blotting. Mast cells and chymase exist in keloid. Gene expression and activity of mast cell chymase in keloid are significantly higher than those in normal skin. Chymase promotes keloid fibroblast proliferation and collagen synthesis by activating TGF-β₁. The activation of Smad protein signaling pathway by chymase is related to the elevated P-Smad protein expression in keloid fibroblasts. Our data demonstrated that mast cell chymase plays an important role in keloid formation through TGF-β₁/Smad signaling pathway.     

Protective roles of pulmonary rehabilitation mixture in experimental pulmonary fibrosis in vitro and in vivo

Abnormal high mobility group protein B1 (HMGB1) activation is involved in the pathogenesis of pulmonary fibrosis. Pulmonary rehabilitation mixture (PRM), which combines extracts from eight traditional Chinese medicines, has very good lung protection in clinical use. However, it is not known if PRM has anti-fibrotic activity. In this study, we investigated the effects of PRM on transforming growth factor-β1 (TGF-β1)-mediated and bleomycin (BLM)-induced pulmonary fibrosis in vitro and in vivo. The effects of PRM on TGF-β1-mediated epithelial-mesenchymal transition (EMT) in A549 cells, on the proliferation of human lung fibroblasts (HLF-1) in vitro, and on BLM-induced pulmonary fibrosis in vivo were investigated. PRM treatment resulted in a reduction of EMT in A549 cells that was associated with attenuating an increase of vimentin and a decrease of E-cadherin. PRM inhibited the proliferation of HLF-1 at an IC₅₀ of 0.51 µg/mL. PRM ameliorated BLM-induced pulmonary fibrosis in rats, with reduction of histopathological scores and collagen deposition, and a decrease in α-smooth muscle actin (α-SMA) and HMGB1 expression. An increase in receptor for advanced glycation end-product (RAGE) expression was found in BLM-instilled lungs. PRM significantly decreased EMT and prevented pulmonary fibrosis through decreasing HMGB1 and regulating RAGE in vitro and in vivo. PRM inhibited TGF-β1-induced EMT via decreased HMGB1 and vimentin and increased RAGE and E-cadherin levels. In summary, PRM prevented experimental pulmonary fibrosis by modulating the HMGB1/RAGE pathway.     

Inflammation induced by increased frequency of intermittent hypoxia is attenuated by tempol administration

The levels of serum inflammatory cytokines and the activation of nuclear factor kappa B (NF-κB) and hypoxia inducible factor-1α (HIF-1α) in heart tissues in response to different frequencies of intermittent hypoxia (IH) and the antioxidant tempol were evaluated. Wistar rats (64 males, 200-220 g) were randomly divided into 6 experimental groups and 2 control groups. Four groups were exposed to IH 10, 20, 30, or 40 times/h. The other 2 experimental groups were challenged with IH (30 times/h) plus tempol, either beginning on day 0 (IH30T0) or on day 29 (IH30T29). After 6 weeks of challenge, serum levels of tumor necrosis factor (TNF)-α, intracellular adhesion molecule (ICAM)-1, and interleukin-10 were measured, and western blot analysis was used to detect NF-κB p65 and HIF-1α in myocardial tissues. Serum levels of TNF-α and ICAM-1 and myocardial expression of NF-κB p65 and HIF-1α were all significantly higher in IH rats than in controls (P<0.001). Increased IH frequency resulted in more significant changes. Administration of tempol in IH rats significantly reduced levels of TNF-α, ICAM-1, NF-κB and HIF-1α compared with the non-tempol-treated group (F=16.936, P<0.001). IH induced an inflammatory response in a frequency-dependent manner. Additionally, HIF-1α and NF-κB were increased following IH administration. Importantly, tempol treatment attenuated this effect.