Attenuation of the Activation of NLRP3 Inflammasome in Fibroblast Like Synoviocytes of Rheumatoid Arthritis by Baicalin through Regulating the Let-7i-3p/PI3K/Akt/NF-κB Signaling Axis

[Objectives]To study the effect and mechanism of baicalin on the activation of NLRP3 inflammasome in human fibroblast like synoviocytes of rheumatoid arthritis(HFLS-RA).[Methods]To confirm that baicalin alleviated the activation of NLRP3 inflammasome in HFLS-RA,the expression of NLRP3 before and after baicalin treatment was observed by immunofluorescence.Western blot was used to detect the protein expression of p-PI3K,p-Akt,NF-κB p65,NLRP3,ASC and caspase-1 after baicalin treatment for 48 h,and the contents of IL-1 and IL-18 in the supernatents were detected by ELISA.In order to explore the mechanism of baicalin alleviating the activation of NLRP3 inflammasome,the corresponding relationship between let-7i-3p and PIK3CA was verified by double luciferin and Westen blot analysis.The expression of let-7i-3p and PI3K before and after baicalin intervention was detected by RT-qPCR.let-7i-3p interference was used to verify whether baicalin mitigated the activation of enhanced NLRP3 inflammasome.[Results]Baicalin(50 and 100 mg/L)significantly reduced the activation of NLRP3 inflammasome,inhibited the protein expressions of p-PI3K,p-Akt,NF-κB p65,NLRP3,ASC and caspase-1,and the secretion of IL-1 and IL-18.let-7i-3p and PIK3CA had a targeted correspondence,and baicalin up-regulated the expression of let-7i-3p and down-regulated the expression of PIK3CA.Baicalin attenuated the activation of NLRP3 inflammasome enhanced by let-7i-3p interference.[Conclusions]Baicalin can up-regulate let-7i-3p expression,inhibit PI3K/Akt/NF-κB signal transduction,and thus reduce the activation of NLRP3 inflammasome in HFLS-RA.

Tetrandrine inhibits migration and invasion of rheumatoid arthritis fibroblast-like synoviocytes through down-regulating the expressions of Rac1, Cdc42, and Rho A GTPases and activation of the PI3K/Akt and JNK signaling pathways

Tetrandrine(Tet), the main active constituent of Stephania tetrandra root, has been demonstrated to alleviate adjuvant-induced arthritis in rats. The present study was designed to investigate the effects of Tet on the migration and invasion of rheumatoid arthritis fibroblast-like synoviocytes(RA-FLS) and explore the underlying mechanisms. By using cultures of primary FLS isolated from synoviums of RA patients and cell line MH7 A, Tet(0.3, 1 μmol·L-1) was proven to significantly impede migration and invasion of RA-FLS, but not cell proliferation. Tet also greatly reduced the activation and expressions of matrix degrading enzymes MMP-2/9, the expression of F-actin and the activation of FAK, which controlled the morphologic changes in migration process of FLS. To identify the key signaling pathways by which Tet exerts anti-migration effect, the specific inhibitors of multiple signaling pathways LY294002, Triciribine, SP600125, U0126, SB203580, and PDTC(against PI3 K, Akt, JNK, ERK, p38 MAPK and NF-κB-p65, respectively) were used. Among them, LY294002, Triciribine, and SP600125 were shown to obviously inhibit the migration of MH7 A cells. Consistently, Tet was able to down-regulate the activation of Akt and JNK as demonstrated by Western blotting assay. Moreover, Tet could reduce the expressions of migration-related proteins Rho GTPases Rac1, Cdc42, and Rho A in MH7 A cells. In conclusion, Tet can impede the migration and invasion of RA-FLS, which provides a plausible explanation for its protective effect on RA. The underlying mechanisms involve the reduction of the expressions of Rac1, Cdc42, and Rho A, inhibition of the activation of Akt and JNK, and subsequent down-regulation of activation and/or expressions of MMP-2/9, F-actin, and FAK.

Protective effects of Dioscin on TNF-α-induced collagen-induced arthritis rat fibroblast-like synoviocytes involves in regulating the LTB4/BLT pathway

Background and Objective:LTB4 has been shown to be involved in rheumatoid arthritis(RA)pathogenesis.The effect of Dioscin(Dio)on the LTB4 pathway of RA have not been reported yet.This study aimed at further exploring whether Dioscin’s effects on TNF-αinduced collagen-induced arthritis(CIA)rat fibroblast-like synoviocytes(FLS)connected with the LTB4 and its receptor pathway.Materials&Methods:In this experiment,control group,TNF-αgroup,and different concentrations of Dioscin groups were established.Cell viability was evaluated using MTT assay.The levels of LTB4 in the samples of above groups were measured using ELISA.The mRNA expression levels of LTA4H,BLT1,and BLT2 were detected by quantitative real time PCR,while the expression level of LTA4H proteins were detected using western blot.The distribution of LTA4H was assessed by immunofluorescence assay.Results:the LTB4 level of TNF-αgroup in sample supernatant was higher than both control group and Dioscin groups with decreased LTB4 levels(p<0.05).Compared with the control group,the expression of LTA4H was significantly increased in TNF-αgroup(p<0.05),whereas LTA4H expressions were significantly decreased in all Dioscin groups when compared to TNF-αgroup(p<0.05).The mRNA expressions of BLT1 and BLT2 were markedly higher in TNF-αgroup than those in control group while Dioscin treatment significantly inhibited the increased expressions of BLT1 and BLT2 induced by TNF-α(p<0.05).Conclusions:These results firstly demonstrate that the protective effect of Dioscin on TNF-αinduced FLS may involve in its reducing LTB4 production by down-regulating LTA4H expression,and may inhibit its downstream pathway by decreasing LTB4 receptors levels.This findings suggest that dioscin produces a potential therapeutic effects for RA via its influencing LTA4H/LTB4/BLT pathway.

Paeoniflorin-6′-O-benzene sulfonate ameliorates progression of adjuvant-induced arthritis by inhibiting interaction between Ahr and GRK2 of fibroblast-like synoviocytes

OBJECTIVE Aryl hydrocarbon receptor(Ahr)is thought to be a crucial factor that regulates immune responses,which may be involved in the pathogenesis of autoimmune inflammation including rheumatoid arthritis(RA).The results of our group in recent years have shown that CP-25,a novel ester derivative of paeoniflorin,has a good effect on improving RA animal models.However,whether the anti-arthritis effect of CP-25 is related to Ahr remains unclear.METHODS CP-25 treatment ameliorated adjuvant-induced arthritis(AA),a mouse model of RA,by inhibiting Ahr-related activities in fibroblasts like synoviocytes(FLS).AA rats were treated with CP-25 or paroxetine from day 17 to 33 after immunization.RESULTS CP-25 alleviated arthritis symptoms and the pathological changes,decreased the expression of Ahr in the synovium and FLS of AA rats.Besides,treatment with CP-25 reduced the proliferation and migration of MH7A caused by Ahr activation.In addition,we also demonstrated that CP-25 down-regulated the co-expression and co-localization of Ahr and G protein-coupled receptor kinase 2(GRK2)in MH7A.CONCLUSION The data presented here demonstrated that CP-25 suppressed FLS dysfunction in rats with AA,which were associated with reduced Ahr activation and the interaction between Ahr and GRK2.

GRK2 mediated degradation of SAV1 initiates hyperplasia of fibroblast-like synoviocytes in rheumatoid arthritis

Hyperplasia and migration of fibroblast-like synoviocytes(FLSs)are the key drivers in the pathogenesis of rheumatoid arthritis(RA)and joint destruction.Abundant Yes-associated protein(YAP),which is a powerful transcription co-activator for proliferative genes,was observed in the nucleus of inflammatory FLSs with unknown upstream mechanisms.Using Gene Expression Omnibus database analysis,it was found that Salvador homolog-1(SAV1),the pivotal negative regulator of the Hippo-YAP pathway,was slightly downregulated in RA synovium.However,SAV1 protein expression is extremely reduced.Subsequently,it was revealed that SAV1 is phosphorylated,ubiquitinated,and degraded by interacting with an important serine-threonine kinase,G protein-coupled receptor(GPCR)kinase 2(GRK2),which was predominately upregulated by GPCR activation induced by ligands such as prostaglandin E2(PGE2)in RA.This process further contributes to the decreased phosphorylation,nuclear translocation,and transcriptional potency of YAP,and leads to aberrant FLSs proliferation.Genetic depletion of GRK2 or inhibition of GRK2 by paroxetine rescued SAV1 expression and restored YAP phosphorylation and finally inhibited RA FLSs proliferation and migration.Similarly,paroxetine treatment effectively reduced the abnormal proliferation of FLSs in a rat model of collagen-induced arthritis which was accompanied by a significant improvement in clinical manifestations.Collectively,these results elucidate the significance of GRK2 regulation of Hippo-YAP signaling in FLSs proliferation and migration and the potential application of GRK2 inhibition in the treatment of FLSs-driven joint destruction in RA.

Nuciferine alleviates collagen-induced arthritic in rats by inhibiting the proliferation and invasion of human arthritis-derived fibroblast-like synoviocytes and rectifying Th17/Treg imbalance

Rheumatoid arthritis(RA)is a chronic autoimmune disorder marked by persistent synovial inflammation and joint degradation,posing challenges in the development of effective treatments.Nuciferine,an alkaloid found in lotus leaf,has shown promising anti-inflammatory and anti-tumor effects,yet its efficacy in RA treatment remains unexplored.This study investigated the antiproliferative effects of nuciferine on the MH7A cell line,a human RA-derived fibroblast-like synoviocyte,revealing its ability to inhibit cell proliferation,promote apoptosis,induce apoptosis,and cause G1/S phase arrest.Additionally,nuciferine significantly reduced the migration and invasion capabilities of MH7A cells.The therapeutic potential of nuciferine was further evaluated in a collagen-induced arthritis(CIA)rat model,where it markedly alleviated joint swelling,synovial hyperplasia,cartilage injury,and inflammatory infiltration.Nuciferine also improved collagen-induced bone erosion,decreased pro-inflammatory cytokines and serum immunoglobulins(IgG,IgG1,IgG2a),and restored the balance between T helper(Th)17 and regulatory T cells in the spleen of CIA rats.These results indicate that nuciferine may offer therapeutic advantages for RA by decreasing the proliferation and invasiveness of FLS cells and correcting the Th17/Treg cell imbalance in CIA rats.

Madecassoside impedes invasion of rheumatoid fibroblast-like synoviocyte from adjuvant arthritis rats via inhibition of NF-κB-mediated matrix metalloproteinase-13 expression

Fibroblast-like synoviocytes(FLS) play a pivotal role in Rheumatoid arthritis(RA) pathogenesis through aggressive migration and invasion. Madecassoside(Madec), a triterpenoid saponin present in Centella asiatica herbs, has a potent anti-inflammatory effect. In the present study, Madec exerted an obvious therapeutic effect in reversing the histological lesions in adjuvant-induced arthritis(AIA) rats. To recognize the anti-rheumatoid potentials of Madec, we further investigated whether Madec interfered with FLS invasion and metalloproteinase(MMP) expression. In cultures of primary FLS isolated from the AIA rats, Madec(10 and 30 μmol·L–1) was proven to considerably inhibit migration and invasion of FLS induced by interleukin 1β(IL-1β), but exhibiting no obvious effect on cell proliferation. Madec repressed IL-1β-triggered FLS invasion by prohibiting the expression of MMP-13. Additionally, Madec suppressed MMP-13 transcription via inhibiting the MMP-13 promoter-binding activity of NF-κB. Our results further showed that Madec down-regulated the translocation and phosphorylation of NF-κB as demonstrated by Western blotting and immunofluorescence assays. In conclusion, our results suggest that Madec exerts anti-RA activity via inhibiting the NF-κB/MMP-13 pathway.

uPAR promotes tumor-like biologic behaviors of fibroblast-like synoviocytes through PI3K/Akt signaling pathway in patients with rheumatoid arthritis

Urokinase-type plasminogen activator receptor(uPAR),is a multifunctional receptor on cell surface,widely present in endothelial cells,fibroblasts,and a variety of malignant cells.Current studies have suggested that uPAR overexpressed on synovial tissues or in synovial fluid or plasma in patients with rheumatoid arthritis(RA).However,there are limited researches regarding the role of uPAR on fibroblast-like synoviocytes of rheumatoid arthritis(RA-FLSs)and its underlying mechanisms.Here,our studies show that the expression of uPAR protein was significantly higher in fibroblast-like synoviocytes(FLSs)from RA than those from osteoarthritis or traumatic injury patients.uPAR gene silencing significantly inhibited RA-FLSs cell proliferation,restrained cell transformation from the G0/G1 phase to S phase,aggravated cell apoptosis,interfered with RA-FLSs cell migration and invasion,and reduced activation of the PI3K/Akt signaling pathway,which may be associated withβ1-integrin.Cell supernatants from uPAR gene-silenced RA-FLSs markedly inhibited the migration and tubule formation ability of the HUVECs(a human endothelial cell line).Therefore,we demonstrate that uPAR changes the biological characteristics of RA-FLSs,and affects neoangiogenesis of synovial tissues in patients with RA.All of these may be associated with theβ1-integrin/PI3K/Akt signaling pathway.These results imply that targeting uPAR and its downstream signal pathway may provide therapeutic effects in RA.

Activity of fibroblast-like synoviocytes in rheumatoid arthritis was impaired by dickkopf-1 targeting siRNA

Background:Fibroblast-like synoviocytes(FLSs),resident mesenchymal cells of synovial joints,play an important role in the pathogenesis of rheumatoid arthritis(RA).Dickkopf-1(DKK-1)has been proposed to be a master regulator of bone remodeling in inflammatory arthritis.Here,potential impairation on the activity of FLSs derived from RA to small interfering RNAs(siRNAs)targeting DKK-1 was investigated.Methods:siRNAs targeting DKK-1 were transfected into FLSs of patients with RA.Interleukin(IL)-1β,IL-6,IL-8,matrix metalloproteinase(MMP)2,MMP3,MMP9,transforming growth factor(TGF)-pi,TGF-β2 and monocyte chemoattractant protein(MCP)-1 levels in the cell culture supernatant were detected by enzyme-linked immunosorbent assay(ELISA).Invasion assay and 3H incorporation assay were utilized to investigate the effects of siRNAs targeting DKK-1 on FLSs invasion and cell proliferation,respectively.Western blotting was performed to analyze the expression of nuclear factor(NF)-kB,interleukin-1 receptor-associared kinase(IRAK)1,extracellular regulated protein kinases(ERK)1,Jun N-terminal kinase(JNK)and p-catenin in FLSs.Results:DKK-1 targeting siRNAs inhibited the expression of DKK-1 in FLSs(P<0.01).siRNAs induced a significant reduction of the levels of IL-6,IL-8,MMP2,MMP3 and MMP9 in FLSs compared to the control group(P<0.05).DKK-1 targeting siRNAs inhibited the proliferation and invasion of FLSs(P<0.05).Important molecules of pro-inflammatory signaling in FLSs,including IRAKI and ERK1,were decreased by the inhibition of DKK-1 in FLSs.In contrast,β-catenin,a pivotal downstream molecule of the Wnt signaling pathway was increased.Conclusions:By inhibiting DKK-1,we were able to inhibit the proliferation,invasion and pro-inflammatory cytokine secretion of FLSs derived from RA,which was mediated by the ERK or the IRAK-1 signaling pathway.These data indicate the application of DKK-1 silencing could be a potential therapeutic approach to RA.

Activation of human fibroblast-like synoviocytes by uric acid crystals in rheumatoid arthritis

Hyperuricemia-mediated uric acid crystal formation may cause joint inflammation and provoke the destruction of joints through the activation of inflammasome-mediated innate immune responses.However,the immunopathological effects and underlying intracellular regulatory mechanisms of uric acid crystal-mediated activation of fibroblast-like synoviocytes(FLS)in rheumatoid arthritis(RA)have not been elucidated.Therefore,we investigated the in vitro effects of monosodium urate crystals,alone or in combination with the inflammatory cytokines tumor-necrosis factor(TNF)-a or interleukin(IL)-1b,on the activation of human FLS from RA patients and normal control subjects and the underlying intracellular signaling mechanisms of treatment with these crystals.Monosodium urate crystals were able to significantly increase the release of the inflammatory cytokine IL-6,the chemokine CXCL8 and the matrix metalloproteinase(MMP)-1 from both normal and RA-FLS(all P,0.05).Moreover,the additive or synergistic effect on the release of IL-6,CXCL8 and MMP-1 from both normal and RA-FLS was observed following the combined treatment with monosodium urate crystals and TNF-a or IL-1b.Further experiments showed that the release of the measured inflammatory cytokine,chemokine and MMP-1 stimulated by monosodium urate crystals were differentially regulated by the intracellular activation of extracellular signal-regulated kinase and c-Jun N-terminal kinase pathways but not the p38 mitogen-activated protein kinase pathway.Our results therefore provide a new insight into the uric acid crystal-activated immunopathological mechanisms mediated by distinct intracellular signal transduction pathways leading to joint inflammation in RA.

Targeted inhibition of GRK2 kinase domain by CP-25 to reverse fibroblast-like synoviocytes dysfunction and improve collagen-induced arthritis in rats

Rheumatoid arthritis(RA)is an autoimmune disease and is mainly characterized by abnormal proliferation of fibroblast-like synoviocytes(FLS).The up-regulated cellular membrane expression of G protein coupled receptor kinase 2(GRK2)of FLS plays a critical role in RA progression,the increase of GRK2 translocation activity promotes dysfunctional prostaglandin E4 receptor(EP4)signaling and FLS abnormal proliferation.Recently,although our group found that paeoniflorin-6’-O-benzene sulfonate(CP-25),a novel compound,could reverse FLS dysfunction via GRK2,little is known as to how GRK2 translocation activity is suppressed.Our findings revealed that GRK2 expression up-regulated and EP4 expression down-regulated in synovial tissues of RA patients and collagen-induced arthritis(CIA)rats,and prostaglandin E2(PGE2)level increased in arthritis.CP-25 could down-regulate GRK2 expression,up-regulate EP4 expression,and improve synovitis of CIA rats.CP-25 and GRK2 inhibitors(paroxetine or GSK180736 A)inhibited the abnormal proliferation of FLS in RA patients and CIA rats by down-regulating GRK2 translocation to EP4 receptor.The results of microscale thermophoresis(MST),cellular thermal shift assay,and inhibition of kinase activity assay indicated that CP-25 could directly target GRK2,increase the protein stability of GRK2 in cells,and inhibit GRK2 kinase activity.The docking of CP-25 and GRK2 suggested that the kinase domain of GRK2 might be an important active pocket for CP-25.G201,K220,K230,A321,and D335 in kinase domain of GRK2 might form hydrogen bonds with CP-25.Site-directed mutagenesis and co-immunoprecipitation assay further revealed that CP-25 down-regulated the interaction of GRK2 and EP4 via controlling the key amino acid residue of Ala321 of GRK2.Our data demonstrate that FLS proliferation is regulated by GRK2 translocation to EP4.Targeted inhibition of GRK2 kinase domain by CP-25 improves FLS function and represents an innovative drug for the treatment of RA by targeting GRK2.

Paeoniflorin-6＇-O-benzene sulfonate, a novel compound, protects against autoimmune arthritis by modulating inflammation and bone damage

Aim Paeoniflorin （Pae） is the principal bioactive component of total glucosides of peony （TGP）, which has been widely used in therapy for rheumatoid arthritis （RA）. Paeoniflorin-6＇-O-benzene sulfonate （code： CP-25） , a novel compound that is a newly ester derivatives of Pae, was evaluated in rats with adjuvant-induced ar- thritis （AA） to study its potential anti-arthritic activity. Methods AA rats were randomly divided into different groups and then treated with CP-25 （25, 50, 100 mg· kg^-1） and methotrexate （0. 5 mg · kg^-1）, from day 16 to day 32 after immunization. Arthritis severity was evaluated by clinical manifestation and histopathological examina- tion. The cells proliferation was determined by CCK-8 assay. Activities of IL-1β, IL-6, IL-17, IL-10, TGF-β1, TNF-oL, IIANKL and OPG were assessed by ELISA. The subsets of CD4 ＋T cells were assayed by flow cytometry. Results CP-25 treatment effectively reduced clinical severity scores and blinded histopathological scores compared with AA groups. CP-25-treated rats exhibited a decrease in the pro-inflammatory cytokines （IL-1β, IL-6, IL-17, and TNF-α） , coupled with an increase in the anti-inflammatory cytokines IL-10 and TGF-β1 in serum and macro- phages of AA rats. The flow cytometry analyses of CD4 ＋T cells dramatically demonstrated the immunomodulatory effects of CP-25 on abnormal immune dysfunction. Apart from the anti-inflammatory activity, treatment with CP-25 inhibited the fibroblast-like synoviocyte （FLS） activation and function. Furthermore, CP-25 treatment of AA rats restored the balance between RANKL and OPG in favor of its anti-osteoclastic effects. Conclusions Data presen- ted here demonstrated that administration of CP-25 significantly inhibited the progression of rat AA, with reductions both in arthritic inflammation and bone damage. The protective effects of CP-25 in AA highlight an attribute that is potential as an ideal new anti-arthritic agent for the treatment with human RA.

miR-let-7d-HMGA2通路调控缺氧诱导的类风湿关节炎滑膜成纤维样细胞增殖

目的 研究缺氧在类风湿关节炎(rheumatoid arthritis,RA)滑膜成纤维样细胞(fibroblast-like synoviocytes,FLS)增殖中的作用及机制。方法 采用HE染色法检测RA和对照骨关节炎(osteoarthritis,OA)滑膜组织FLS增生情况。分离原代RA-FLS并采用流式细胞术鉴定;将RA-FLS置于常氧(21%O_(2))或缺氧环境(3%O_(2))中培养,CCK-8法检测细胞增殖水平的变化,RT-PCR检测miR-let-7d表达的变化。通过类似物或抑制物改变miR-let-7d的表达,观察其对RA-FLS增殖、凋亡的影响;探究miR-let-7d靶基因在缺氧诱导的RA-FLS增殖中的作用。结果 FLS在RA滑膜中增生明显,在缺氧环境下RA-FLS增殖加快,miR-let-7d表达水平降低;过表达miR-let-7d抑制RA-FLS增殖,但对细胞凋亡水平无明显影响;进一步的研究证实miR-let-7d靶基因HMGA2参与缺氧诱导的RA-FLS增殖。结论 miR-let-7d-HMGA2通路调控缺氧诱导的RA-FLS增殖。

针刀疏筋解结术对类风湿关节炎家兔滑膜炎症的影响及作用机制研究

目的观察针刀疏筋解结术对类风湿关节炎(RA)模型家兔膝关节滑膜组织NF-κB/Bcl-2通路活性及肿瘤坏死因子-α(TNF-α)、白细胞介素(IL)-1β、IL-6、Bax、caspase-3表达的影响,探讨其抑制RA滑膜炎症的作用机制。方法24只新西兰白兔随机分为正常组、模型组、药物组和针刀组,每组6只,除正常组外,其余组采用卵蛋白+弗氏完全佐剂膝关节腔注射复制RA模型,分别予相应干预,连续18 d。测定家兔膝关节痛阈、膝关节周径,超声观察关节腔积液、滑膜厚度及内部血流信号,HE染色观察膝关节滑膜组织形态,TUNEL染色观察滑膜组织成纤维样滑膜细胞(FLS)凋亡情况,免疫组化检测滑膜组织TNF-α、IL-1β、IL-6表达,RT-PCR检测滑膜组织核因子(NF)-κBp65、Bcl-2mRNA表达,Westernblot检测滑膜组织NF-κBp65、p-NF-κBp65、Bcl-2、Bax、caspase-3蛋白表达。结果与正常组比较,模型组家兔膝关节痛阈降低、膝关节周径增加,超声评分和滑膜组织病理评分增加;滑膜组织FLS凋亡率降低,TNF-α、IL-1β、IL-6表达升高,NF-κBp65、Bcl-2 mRNA和蛋白及p-NF-κBp65蛋白表达升高,Bax、caspase-3蛋白表达降低,差异均有统计学意义(P<0.05)。与模型组比较,药物组和针刀组家兔膝关节痛阈增加、膝关节周径减小,超声评分和滑膜组织病理评分减少;滑膜组织FLS凋亡率升高,TNF-α、IL-1β、IL-6表达降低,NF-κBp65、Bcl-2m RNA和蛋白及p-NF-κBp65蛋白表达降低,Bax、caspase-3蛋白表达升高,差异均有统计学意义(P<0.05)。结论针刀疏筋解结术可能通过降低滑膜组织NF-κB/Bcl-2通路活性,促进FLS凋亡,减少TNF-α、IL-1β、IL-6产生,抑制RA滑膜炎症,减轻膝关节肿胀、提升痛阈。

Inhibition of smoothened decreases proliferation of Synoviocytes in rheumatoid arthritis

Fibroblast-like synoviocytes （FLSs） contribute to synovial hyperplasia in rheumatoid arthritis （RA）. Smoothened （Smo） is a key component of sonic hedgehog （Shh） signaling and contributes to tumor cell proliferation. The objective of this study was to investigate the role of Smo in RA synoviocyte proliferation. FLSs were isolated from RA synovium. Shh signaling was studied using a Smo antagonist （GDC-0449） and small interfering RNA （siRNA） targeting the Smo gene in FLSs. Cell proliferation was quantified by using kit-8 assay and cell cycle distribution and apoptosis were evaluated by flow cytometry. Cell cycle-related genes and proteins were detected by real-time PCR and western blot. FLSs treated with GDC-0449 or Smo-siRNA showed significantly decreased proliferation compared to controls （P〈0.05）. Incubation with GDC-0449 or transfection with Smo-siRNA resulted in a significant increase of G1 phase cells compared to controls （P 〈 0.05）. Cell cycle arrest was validated by the significant increase in cyclin D1 and E1 mRNA expression, decrease in cyclin-dependent kinase p21 mRNA expression in Smo-siRNA transfected cells （P 〈 0.05）. Protein expression of cyclin D1 was also downregulated after Smo gene knockdown （P 〈0.05）.The results suggest that Shh signaling plays an important role in RA-FLSs proliferation in a Smo-dependent manner and may contribute to synovial hyperplasia. Targeting Shh signaling may help control joint damage in patients with RA.

Expression of C5aR ( CD88) of synoviocytes isolated from patients with rheumatoid arthritis and osteoarthritis

Objective To investigate the expression of anaphylatoxin receptor C5aR (CD88) in synoviocytes from patients with rheumatoid arthritis (RA) and osteoarthritis (OA).Methods The expression of C5aR was assessed in synoviocytes isolated from 27 RA and 12 OA patients using reverse transcription-polymerase chain reactions (RT-PCR), flow cytometry, and immunofluorescence analysis. The effects of C5a on the release of tumor necrosis factor a (TNFα) from synoviocytes were assayed using enzyme-linked immunosorbent assays (ELISA).Results C5aR mRNA was detected in 24 of 27 samples from RA patients, and 10 of 12 samples from OA patients. Flow cytometric analysis and immunofluorescence study demonstrated the cell surface expression of C5aR in a significant proportion of synoviocytes from both RA and OA patients, and the level of C5aR expression in synoviocytes was significantly correlated with joint swelling, erythrocyte sedimentation rate ( ESR) and C-reactive protein ( CRP) in RA patients. Finally, interaction of C5aR with its ligand C5a was shown to enhance lipopolysaccharide (LPS) -induced TNFa release from synoviocytes.Conclusions The expression of C5aR in synoviocytes from inflammatory joint diseases and also the induction of TNFa release in activated synovicytes by the interaction of C5a and C5aR suggest that the C5a/C5aR system may play an important role in joint inflammation process.

汉黄芩素对胶原诱导性关节炎大鼠关节炎症影响的内质网应激途径

背景:类风湿关节炎是一种炎性疾病,已有多项研究表明汉黄芩素具有较好的抗炎作用,但其对类风湿关节炎的确切疗效和具体作用机制尚待阐明。目的:探讨汉黄芩素通过调节内质网应激途径改善胶原诱导性关节炎大鼠关节炎症的作用机制。方法:①动物水平:雌性Wistar大鼠分为健康对照组、关节炎模型组、汉黄芩素治疗组,通过皮下注射牛Ⅱ型胶原与弗式佐剂构建胶原诱导性关节炎大鼠模型,治疗组在成功造模后给予连续28 d汉黄芩素灌胃治疗;在此期间,每隔7 d对各组大鼠进行体质量、关节炎评分和踝关节肿胀度测量;实验结束后,观察关节病理变化,qRT-PCR和Western Blot、免疫组化检测关节中内质网应激通路GRP78、CHOP mRNA和蛋白表达水平。②细胞水平:CCK-8检测汉黄芩素对胶原诱导性关节炎大鼠成纤维样滑膜细胞的细胞毒作用;不同浓度汉黄芩素处理毒胡萝卜素诱导的成纤维样滑膜细胞,ELISA检测细胞上清白细胞介素1β、肿瘤坏死因子α水平,DCFH-DA探针法测定各组细胞内活性氧簇,qRT-PCR和Western Blot检测GRP78、IRE1α、XBP1s、CHOP mRNA和蛋白水平。结果与结论:①与健康对照组相比,关节炎模型组关节炎指数评分、踝关节肿胀度升高(P<0.01),病理切片可见滑膜增生及炎症细胞浸润、软骨破坏和骨质侵蚀,踝关节GRP78、CHOP mRNA和蛋白表达显著增多(P<0.01),主要定位在滑膜组织和关节面;与关节炎模型组相比,汉黄芩素治疗组关节炎指数评分、踝关节肿胀度降低(P<0.05),滑膜增生及炎症细胞减少,软骨破坏和骨质侵蚀减轻,踝关节GRP78、CHOP mRNA和蛋白表达减少(P<0.05),在滑膜组织和关节面显著降低;3组大鼠体质量无显著差别(P>0.05)。②细胞实验中,200μmol/L汉黄芩素组可明显降低成纤维样滑膜细胞存活率(P<0.01);与空白对照组相比,毒胡萝卜素组细胞上清白细胞介素1β、肿瘤坏死因子α水平、活性氧含量、GRP78、IRE1α、XBP1s、CHOP mRNA及蛋白表达显著增多(P<0.05);与毒胡萝卜素组相比,50μmol/L和100μmol/L汉黄芩素组可降低细胞上清白细胞介素1β、肿瘤坏死因子α水平(P<0.05,P<0.01),100μmol/L汉黄芩素组可明显减少活性氧含量(P<0.01)、下调GRP78、IRE1α、XBP1s、CHOP mRNA及蛋白表达水平(P<0.05)。③结果提示汉黄芩素可以有效改善胶原诱导性关节炎大鼠的关节炎症反应,且内质网应激途径可能是其干预的关键靶点。

低强度脉冲超声通过p38/JNK-白细胞介素-6抑制类风湿性关节炎滑膜成纤维细胞增殖的研究

目的:探讨低强度脉冲超声(low-intensity pulsed ultrasound,LIPUS)对类风湿性关节炎滑膜成纤维细胞(fibroblastlike synoviocytes in rheumatoid arthritis,RA-FLS)异常细胞表型的抑制作用及可能机制。方法:酶消化法分离滑膜细胞,显微镜下观察细胞形态,同时用免疫荧光检测Vimentin蛋白表达来鉴定RA-FLS。将细胞进行体外培养并分为4组:对照组、LIPUS组、肿瘤坏死因子-α(tumor necrosis factor,TNF-α)组和TNF-α+LIPUS组或3组:对照组、白细胞介素-6(interleukin-6,IL-6)组和IL-6+LIPUS组。CCK8和EDU实验分别检测LIPUS对RA-FLS细胞活性和增殖的作用,划痕实验和Transwell迁移实验观察LIPUS对RA-FLS迁移能力的影响,RT-q PCR检测RA-FLS中重要的细胞因子、趋化因子和基质金属蛋白酶(matrix metalloproteinases,MMPs)的基因表达,ELISA进一步检测LIPUS对RA-FLS中关键效应分子IL-6蛋白水平的作用,Western Blot检测LIPUS对RAFLS中丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)信号通路的影响。结果:分离得到较纯净的RA-FLS。在体外培养的RA-FLS中,首先,LIPUS可以抑制TNF-α诱导的细胞活性(P<0.001)和增殖(P=0.007),但它对其迁移及迁移相关MMPs(MMP2和MMP9)转录水平的作用在组间无显著性差异(P>0.05)。在TNF-α诱导的炎性环境下,LIPUS能够抑制IL-6和白细胞介素-8(interleukin-8,IL-8)在m RNA水平上的高表达(P<0.001),但其对白细胞介素-1β(interleukin-1β,IL-1β)、MMP1和MMP13的抑制作用在组间无显著性差异(P>0.05)。与未处理组相比,LIPUS抑制TNF-α诱导的RA-FLS中IL-6的分泌(P<0.001),同时也抑制IL-6诱导的RA-FLS增殖(P=0.003)。LIPUS能够抑制MAPK信号通路中p38 MAPK(P=0.033)的磷酸化和c-Jun氨基末端激酶(c-Jun N-terminal kinase,JNK)的磷酸化(P=0.019),但其对细胞外信号调节激酶1/2(extracellular signalregulated kinas 1/2,ERK1/2)蛋白的磷酸化则无显著作用(P>0.05)。结论:LIPUS能够减少炎性状态下RA-FLS的异常增殖而不作用于其迁移,该作用可能与p38/JNK-IL-6信号通路的抑制有关。

红景天苷调控miR-20a-5p/TIMP2轴对类风湿关节炎成纤维样滑膜细胞增殖和迁移的影响

目的探讨红景天苷调控miR-20a-5p/金属蛋白酶组织抑制剂-2(TIMP2)轴对人类风湿关节炎成纤维样滑膜细胞(HFLS-RA)功能和活化的影响。方法以HFLS-RA细胞为研究对象,将HFLS-RA细胞分为肿瘤坏死因子-α(TNF-α)组、对照组、红景天苷组、miR-20a-5p抑制物阴性对照(inhibitor NC)组、miR-20a-5p抑制物组、红景天苷+miR-20a-5p模拟物阴性对照(mimic NC)组、红景天苷+miR-20a-5p模拟物组。实时荧光定量聚合酶链反应(qRT-PCR)检测HFLS-RA细胞中miR-20a-5p表达;酶联免疫吸附试验(ELISA)检测HFLS-RA细胞上清液中白细胞介素(IL)-1β、IL-6水平;细胞计数试剂盒8(CCK-8)法、5-乙炔基-2’-脱氧尿苷(EdU)染色检测HFLS-RA细胞增殖;划痕实验检测HFLS-RA细胞迁移;免疫印迹实验(Western blot)检测HFLS-RA细胞中TIMP2、细胞周期素D1(CyclinD1)、基质金属蛋白酶(MMP)-9蛋白表达;双荧光素酶验证miR-20a-5p与TIMP2的关系。结果与对照组比较,TNF-α组miR-20a-5p表达、IL-1β、IL-6水平、吸光度(OD_(450))值、EdU阳性细胞率、划痕愈合率及CyclinD1、MMP-9蛋白上调,TIMP2蛋白下调(P<0.05);与TNF-α组相比,红景天苷组miR-20a-5p表达、IL-1β、IL-6水平、OD_(450)值、EdU阳性细胞率、划痕愈合率及CyclinD1、MMP-9蛋白下调,TIMP2蛋白上调(P<0.05);与inhibitor NC组、TNF-α组相比比较,miR-20a-5p抑制物组miR-20a-5p表达、IL-1β、IL-6水平、OD_(450)值、EdU阳性细胞率、划痕愈合率及CyclinD1、MMP-9蛋白下调,TIMP2蛋白上调(P<0.05);与红景天苷+mimic NC组、红景天苷组相比,红景天苷+miR-20a-5p模拟物组miR-20a-5p表达、IL-1β、IL-6水平、OD_(450)值、EdU阳性细胞率、划痕愈合率及CyclinD1、MMP-9蛋白表达升高,TIMP2蛋白表达降低(P<0.05)。miR-20a-5p与TIMP2存在靶向调控关系。结论红景天苷可能通过调控miR-20a-5p/TIMP2抑制TNF-α诱导的HFLS-RA细胞增殖、迁移及炎症反应。

LYVE1+巨噬细胞在RA患者关节滑膜组织中表达变化及对RA-FLS细胞迁移、侵袭、FMT的抑制作用

目的观察淋巴管内皮受体-1(LYVE1)+巨噬细胞在类风湿性关节炎(RA)患者关节滑膜组织中的表达变化及对RA成纤维样滑膜细胞(RA-FLS)迁移、侵袭、向肌成纤维细胞转化(FMT)的抑制作用。方法采用免疫荧光染色法对45例RA患者及45例骨关节炎(OA)患者滑膜组织LYVE1、CD68进行定性、定量检测。取对数生长期人单核白血病细胞THP-1,在培养液中加入LYVE1过表达慢病毒,培养48 h获得表达LYVE1的THP-1细胞,在表达LYVE1的THP-1细胞中加入100 ng/mL的佛波酯(PMA)诱导培养48 h,获得LYVE1+巨噬细胞;另取部分THP-1细胞,仅加入100 ng/mL的PMA诱导培养48 h获得LYVE1-巨噬细胞。取对数生长期人类风湿性关节炎成纤维细胞MH7A分为LYVE1+巨噬细胞组、LYVE1-巨噬细胞组,分别加入LYVE1+巨噬细胞、LYVE1-巨噬细胞,另将仅含培养基的小室设为空白对照组,采用划痕实验观察各组细胞的迁移能力。取MH7A细胞分为A组、B组,分别加入LYVE1+巨噬细胞、LYVE1-巨噬细胞,将仅含培养基小室设为C组,采用Transwell侵袭实验观察各组细胞的侵袭能力。取MH7A细胞分为一组、二组,分别加入LYVE1+巨噬细胞、LYVE1-巨噬细胞,将仅含培养基小室设为空白组,培养48 h时采用实时定量PCR法检测各组MH7A细胞FMT相关基因(COL1A1、fibronectin、α-SMA)的mRNA。结果RA与OA患者滑膜组织中LYVE1、CD68表达位置基本重叠;RA与OA患者滑膜组织LYVE1相对表达量分别为0.319±0.033、1.000±0.159,二者比较,P<0.05。与LYVE1-巨噬细胞组、空白对照组比较,培养24、48 h时LYVE1+巨噬细胞组细胞划痕愈合比低(P均<0.05);与B组、C组比较,培养24 h时A组细胞穿膜细胞数少(P均<0.05);与二组、空白组比较,培养48 h时一组细胞COL1A1 mRNA、fibronectin mRNA、α-SMA mRNA相对表达量少(P均<0.05)。结论RA患者关节滑膜组织中LYVE1+巨噬细胞低表达。LYVE1+巨噬细胞可抑制RA-FLS的迁移、侵袭及FMT。