Yaou Zhou

MicroRNA Expression Abnormalities in Limited Cutaneous Scleroderma and Diffuse Cutaneous Scleroderma

Scleroderma (systemic sclerosis, SSc) is a complex autoimmune disease caused by progressive fibrotic replacement of normal tissue architecture, a progressive and ultimately fatal process that currently has no cure. Although dysregulation of microRNAs (miRNAs) is known to be involved in a variety of pathophysiologic processes, the role of miRNAs in SSc is unclear. In comparison with the normal skin tissues, miRNAs were aberrantly expressed in limited cutaneous scleroderma and diffuse cutaneous scleroderma skin tissues. We also identified miRNAs whose expressions were correlated with SSc fibrosis: miR-21, miR-31, miR-146, miR-503, miR-145, and miR-29b were predicted to be involved. This study further confirmed that miR-21 was increased whereas miR-145 and miR-29b were decreased both in the skin tissues and fibroblasts. As predicted target genes, SMAD7, SAMD3, and COL1A1 were regulated by these miRNAs. After stimulation with transforming growth factor β, the expression of miR-21 was increased and that of SMAD7 mRNA was decreased. MiR-145 was upregulated whereas the mRNA level of SMAD3 was downregulated. The downregulation of miR-29b was correlated with the upregulation of COL1A1 mRNA. MiRNAs might play an important role in the pathogenesis of SSc and suggest a potential therapy.

MicroRNA-21 in Scleroderma Fibrosis and its Function in TGF-β- Regulated Fibrosis-Related Genes Expression

Uncontrolled fibrosis in multiple organs is the main cause of death in systemic sclerosis (SSc), and transforming growth factor-β (TGF-β) activation plays a fundamental role in the process. Our previous study demonstrated that miR-21 was significantly up-regulated in SSc fibroblasts. Here, we found that TGF-β regulated the expression of miR-21 and fibrosis-related genes, and decreased Smad7 expression. Over-expression of miR-21 in fibroblasts decreased the levels of Smad7, whereas knockdown of miR-21 increased its expression. Further study using a reporter gene assay demonstrated Smad7 was a direct target of miR-21. Similar to human SSc, the expression of miR-21 increased in the bleomycin induced skin fibrosis. Inhibition of fibrosis by treatment with anti-fibrosis drug bortezomib restored the levels of miR-21 and Smad7. MiR-21 may function in an amplifying circuit to enhance TGF-β signaling events in SSc fibrosis, and suggesting that miR-21 may act as a potential therapeutic target.Uncontrolled fibrosis in multiple organs is the main cause of death in systemic sclerosis (SSc), and transforming growth factor-β (TGF-β) activation plays a fundamental role in the process. Our previous study demonstrated that miR-21 was significantly up-regulated in SSc fibroblasts. Here, we found that TGF-β regulated the expression of miR-21 and fibrosis-related genes, and decreased Smad7 expression. Over-expression of miR-21 in fibroblasts decreased the levels of Smad7, whereas knockdown of miR-21 increased its expression. Further study using a reporter gene assay demonstrated Smad7 was a direct target of miR-21. Similar to human SSc, the expression of miR-21 increased in the bleomycin induced skin fibrosis. Inhibition of fibrosis by treatment with anti-fibrosis drug bortezomib restored the levels of miR-21 and Smad7. MiR-21 may function in an amplifying circuit to enhance TGF-β signaling events in SSc fibrosis, and suggesting that miR-21 may act as a potential therapeutic target.

Extracellular heat shock protein 70 inhibits tumour necrosis factor-α induced proinflammatory mediator production in fibroblast-like synoviocytes

IntroductionIt was recently suggested that heat shock protein (HSP)70, an intracellular protein, is a potential mediator of inflammatory disease when it is released into the extracellular compartment. Although elevated HSP70 levels have been identified in rheumatoid arthritis (RA) synovial tissues and RA synovial fluid compared with patients with osteoarthritis and healthy individuals, it remains unclear what role extracellular HSP70 plays in the pathogenesis of RA. This study was conducted to investigate the effects of extracellular HSP70 on the production of RA-associated cytokines in fibroblast-like synoviocytes from patients with RA and to elucidate the mechanisms involved.MethodsIL-6, IL-8 and monocyte chemoattractant protein (MCP)-1 levels in culture supernatants were measured using enzyme-linked immunosorbent assays. Activation of mitogen-activated protein kinases (MAPKs), such as extracellular signal-regulated protein kinases (ERKs), c-Jun amino-terminal kinase (JNK) and p38 MAPK, was detected using Western blotting. Nuclear translocation of nuclear factor-κB (NF-κB) and degradation of the inhibitory protein IκBα were examined using immunohistochemistry and Western blotting.ResultsHuman HSP70 downregulated IL-6, IL-8 and MCP-1 production in RA fibroblast-like synoviocytes induced by tumour necrosis factor (TNF)-α in a concentration dependent manner. HSP70 inhibited the activation of ERK, JNK and p38 MAPK in fibroblast-like synoviocytes stimulated by TNF-α. Furthermore, HSP70 also significantly inhibited nuclear translocation of nuclear factor-κB and degradation of IκBα induced by TNF-α.ConclusionExtracellular HSP70 has an anti-inflammatory effect on RA by downregulating production of IL-6, IL-8 and MCP-1 in fibroblast-like synoviocytes, which is mediated through inhibited activation of the MAPKs and NF-κB signal pathways.

Release of heat shock protein 70 and the effects of extracellular heat shock protein 70 on the production of IL-10 in fibroblast-like synoviocytes

It has recently been suggested that heat shock protein (Hsp) 70, an intracellular protein, can be released into the extracellular compartment and exert important immunomodulatory functions. Although elevated Hsp70 has been found in synovial fluid from patients with rheumatoid arthritis (RA), its sources and extracellular functions remain unclear. In this study, we explored whether stress response such as heat stress or exposure to tumor necrosis factor-α (TNF-α) could induce Hsp70 release from RA fibroblast-like synoviocytes (FLSs) and whether extracellular Hsp70 would stimulate cytokine production in RA FLSs. Cultured FLSs were obtained from patients with RA. The expression of intracellular Hsp70 was studied by Western blot. Hsp70 release and the production of interleukin (IL)-6, IL-8, and IL-10 by RA FLSs were studied by specific enzyme-linked immunosorbent assays. The levels of Toll-like receptor (TLR) 2 and 4 mRNA and protein in FLSs were analyzed using reverse transcription-polymerase chain reaction and Western blotting. Treatment with sublethal heat shock or TNF-α results in the up-regulation of intracellular Hsp70 in FLSs and Hsp70 release from RA FLSs. In vitro studies show that extracellular Hsp70 can induce anti-inflammatory cytokine IL-10 production in FLSs. The mRNA and protein expression of TLR2 and TLR4 was demonstrated in FLSs, and TLR4 blocking abrogated the up-regulatory effects of Hsp70 on IL-10 production. Thus, these results lend support to the hypothesis that Hsp70 is actively released from FLSs in response to heat shock or TNF-α and Hsp70 may be a major paracrine/autocrine inducer of IL-10 production in FLSs via TLR4.

Treatment with Recombinant Hsp72 Suppresses Collagen-Induced Arthritis in Mice

Although the level of heat shock protein (Hsp72) has been shown to be enhanced in rheumatoid arthritis (RA) synovial tissues and RA synovial fluid, it remains unclear what role extracellular Hsp72 plays in the pathogenesis of RA. This study was conducted to investigate the effects of recombinant human Hsp72 on collagen-induced arthritis (CIA) when administered therapeutically and elucidate its underlying mechanism. We demonstrated that recombinant Hsp72 significantly reduced disease severity. Hsp72-treated animals displayed significantly less cartilage and bone destruction than that in the controls. Hsp72 treatment also reduced the expression of tumor necrosis factor alpha and interleukin 6 in the sera. Furthermore, Hsp72 treatment significantly inhibited activation of nuclear factor kappa B (NF-κB) in synovial tissues of CIA mice. These findings suggest that recombinant Hsp72 effectively suppressed synovial inflammation and the development and progress of CIA, which is mediated through the reduction of production of proinflammatory cytokines and the suppression of activation of NF-κB pathway.

Activation of the cholinergic anti-inflammatory system by nicotine attenuates arthritis via suppression of macrophage migration

Activation of the cholinergic anti-inflammatory pathway (CAP), which relies on the alpha-7 nicotinic acetylcholine receptor, has been reported to reduce proinflammatory cytokine levels in experimental arthritis. To gain more insight regarding the role of the CAP in the pathogenesis of arthritis, the present study focused on the modulation of macrophage infiltration. In a mouse model of collagen-induced arthritis (CIA), nicotine and vagotomy were used to stimulate and inhibit the CAP, respectively. Subsequently, arthritic scores were measured and histopathological assessment of joint sections was conducted. Cluster of differentiation (CD)11b-positive macrophages in the synovium were studied by immunofluorescence histochemistry. The serum levels of chemokines, including macrophage inflammatory protein (MIP)-1α, monocyte chemoattractant protein (MCP)-1 and MIP-2 were evaluated by ELISA. Furthermore, the expression levels of C-C chemokine receptor (CCR)2 and intercellular adhesion molecule (ICAM)-1 in the synovium were evaluated by immunohistochemical staining. The results indicated that treatment with nicotine significantly attenuated the clinical and histopathological changes associated with arthritis, reduced CD11b-positive macrophages in the synovium, and downregulated the serum expression levels of MIP-1α and MCP-1. Conversely, vagotomy aggravated arthritis and upregulated the expression levels of MCP-1. However, MIP-2 expression did not differ among the control, CIA, vagotomy and nicotine groups. In addition, the expression levels of CCR2 were reduced in the nicotine group; however, they were increased in the vagotomy group compared with in the untreated CIA group. The expression levels of ICAM-1 in the synovium were also influenced by activation of the CAP. Taken together, the present results indicated that nicotine-induced activation of the CAP in mice with CIA may reduce the number of macrophages in the synovium, which may serve a role in alleviating arthritis in mice.

Tumor necrosis factor antagonists in the treatment of multicentric reticulohistiocytosis: Current clinical evidence.

Multicentric reticulohistiocytosis (MRH) is a rare and debilitating systemic disorder characterized by cutaneous nodules and destructive polyarthritis. Due to its unknown etiology, the treatment of MRH varies with different rates of success, which causes treatment options to be rather independent and empirical. In the present study, a case of a 48-year-old woman with a 12-month history of polyarthralgia and skin nodules was reported. Biopsy samples, which were obtained from her skin eruption exhibited dermal infiltration with histiocytes and multinucleated giant cells. Immunohistochemical staining indicated positivity for CD68. The patient was diagnosed with MRH and treated with a combination therapy of infliximab, prednisolone and methotrexate. Her symptoms improved markedly within 2 weeks. Following the results of this case study, a systematic review of 17 cases of MRH treated with tumor necrosis factor (TNF) antagonists was performed, and the efficacy of anti-TNF treatment in MRH was analyzed.

Regulatory effect of nicotine on the differentiation of Th1, Th2 and Th17 lymphocyte subsets in patients with rheumatoid arthritis

Abstract Previous research has demonstrated that nicotine have protective role in rheumatoid arthritis (RA). However, the immunologic mechanisms of nicotines effect have not been fully elucidated. Herein, the effects of nicotine on the differentiation of Th1, Th2, and Th17 cells were assessed. Peripheral blood mononuclear cells (PBMCs) and CD4+T cells were separated from patients with RA. PBMCs were stimulated with anti‐CD3/anti‐CD28 in the absence or presence of nicotine. CD4+T cells were cultured in the Th cell differentiation condition in the absence of nicotine or nicotine and alpha‐ bungarotoxin (&agr;Bgt) (the antagonist of nicotine) combined. Levels of T cell cytokines were detected with ELISA and flow cytometry. The expression of specific transcription factors (retinoic orphan re‐ ceptor c (RORc), T‐box transcription factor (T‐bet), and GATA Binding Protein 3 (GATA‐3)) and signaling molecules (P‐ERK1/2 and T‐ERK1/2) were determined by Western blot. The results showed nicotine reduced IL‐17A and increased IL‐4 produced by stimulated PBMCs. During Th17 differentiation conditions, nicotine reduced the levels of IL‐17A and RORc, induced the phosphorylation of ERK1/2. Meanwhile, nicotine increased the levels of IL‐4 and GATA3 during Th2 differentiation. &agr;‐Bgt blocked the effects of nicotine on Th2 and Th17 differentiation. However, nicotine had no effect on the expression of IFN‐&ggr; and T‐bet in CD4+T cells during Th1differentiation. These results demonstrate that nicotine suppresses Th17 differentiation, promotes Th2 differentiation and improves Th1/Th2 imbalance in RA patients, providing a new justification for its application in the treatment of rheumatoid arthritis.

The coexistence of autoimmune rheumatic diseases and thymomas

BACKGROUND Autoimmune rheumatic diseases (ARDs), involving immune disturbances resulting from auto-inflammatory mechanisms, are a group of diseases characterized by autoimmunity and autoimmunemediated organ damage. Thymoma, whose mechanism is also associated with immune abnormalities, is the most common neoplasm of the anterior mediastinum. But thymoma with ARDs is relatively less frequent. The clinical characteristics of the coexistence of ARDs and thymomas are still not very clear. And the therapeutic strategy for ARDs combined with thymomas varies, with an uncertain outcome. OBJECTIVES The aim of this study was to investigate the clinical characteristics of the coexistence of ARDs and thymomas in order to speculate whether a thymectomy is effective for ARDs combined with thymomas, and to seek the proper therapeutic strategy for treating ARDs combined with thymomas. MATERIAL AND METHODS We presented 2 cases of the coexistence of ARDs and thymomas. Then, we summarized 20 cases (including our 2 cases) in which the ARD was diagnosed concurrently with, or prior to, the thymoma. RESULTS Pure red cell aplastic anemia (PRCA) might be associated with an ARD and a thymoma, and a thymectomy may lead to the appearance, exacerbation, or remission of ARDs. CONCLUSIONS Searching for a thymoma is necessitated if a patient with ARDs experiences PRCA and the effects of thymectomy in ARDs combined with thymomas may be associated with the onset sequence of ARDs and thymomas.

Investigation into the cause of mortality in 49 cases of idiopathic inflammatory myopathy: A single center study.

Idiopathic inflammatory myopathy (IIM) is an autoimmune disease characterized by chronic muscle weakness and myositis with unknown etiology. IIM may affect the function of multiple organs and has a poor prognosis. In the present study, the causes of mortality in patients with IIM admitted to the Xiangya Hospital during the last 14 years were investigated. The investigation included an analysis of frequent causes of IIM, and of infections and associated complications. A cohort study was conducted on 676 patients with IIM that were admitted to Xiangya Hospital from January, 2001 to January, 2015. There were 49 patient mortalities (7.2% of the total cases), of which 34 mortalities were infection-associated and 15 were not infection-associated. The proportion of infection-associated IIM mortalities had increased since 2001. Of the 34 infection-associated mortalities, 31 cases (63.3%) were of fungal and bacterial infections, most frequently infecting the lungs and the blood. Klebsiella pneumoniae and Acinetobacter baumannii were the most commonly isolated pathogens, and co-infection with the two pathogens was observed in the majority of cases. In the IIM mortalities not associated with infection, there were 2 acute myocardial infarction cases, 2 acute interstitial lung disease cases, 4 malignancies and 1 case of each of the following: Arrhythmia, pneumothorax, ventilator weakness, pulmonary artery hypertension, gastrointestinal bleeding, liver failure and renal failure. Three mortalities were secondary to viral hepatitis in the present study. Pathogenic infection was the most frequent cause of mortality in patients with IIM. The remaining causes of mortality included secondary to heart failure, lung dysfunction and malignancy. Following the ubiquitous application of glucocorticoids and immunosuppressants, the proportion of infection-associated mortalities increased in patients with IIM. Thus, in addition to focusing on the primary disease, infection should receive increased attention during clinical practice.