Small heterodimer partner interacting leucine zipper protein (SMILE) ameliorates autoimmune arthritis via AMPK signaling pathway and the regulation of B cell activation.

Rheumatoid arthritis (RA) is an autoimmune disease that causes joint swelling and inflammation and can involve the entire body. RA is characterized by the increase of pro-inflammatory cytokines such as interleukin (IL) and tumor necrosis factor, and the over-activation of T lymphocytes and B lymphocytes, which may lead to severe chronic inflammation of joints. However, despite numerous studies the pathogenesis and treatment of RA remain unresolved. This study investigated the use of small heterodimer partner-interacting leucine zipper protein (SMILE) overexpression to treat a mouse model of RA. SMILE is an insulin-inducible corepressor through adenosine monophosphate-activated kinase (AMPK) signaling pathway. The injection of a SMILE overexpression vector to mice with collagen induced-arthritis resulted in a milder clinical pathology and a reduced incidence of arthritis, less joint tissue damage, and lower levels of Th17 cells and plasma B cells in the spleen. Immunohistochemistry of the joint tissue showed that SMILE decreased B-cell activating factor (BAFF) receptor (BAFF-R), mTOR, and STAT3 expression but increased AMPK expression. In SMILE-overexpressing transgenic mice with collagen antibody-induced arthritis (CAIA), a decrease in the arthritis score and reductions in tissue damage, the number of B cells, and antibody production were observed. The treatment of immune cells in vitro with curcumin, a known SMILE-inducing agent, led to decreases in plasma B cells, germinal center B cells, IL-17-producing B cells, and BAFF-R-positive B cells. Taken together, our findings demonstrate the therapeutic potential of SMILE in RA, based on its inhibition of B cell activation mediated by the AMPK/mTOR and STAT3 signaling pathway and BAFF-R expression. Video abstract.

Tannic acid, an IL-1ß-direct binding compound, ameliorates IL-1ß-induced inflammation and cartilage degradation by hindering IL-1ß-IL-1R1 interaction.

Interleukin-1ß (IL-1ß) is one of the most potent pro-inflammatory cytokines implicated in a wide range of autoinflammatory, autoimmune, infectious, and degenerative diseases. Therefore, many researchers have focused on developing therapeutic molecules that inhibit IL-1ß-IL-1 receptor 1 (IL-1R1) interaction for the treatment of IL-1-related diseases. Among IL-1-related diseases, osteoarthritis (OA), is characterized by progressive cartilage destruction, chondrocyte inflammation, and extracellular matrix (ECM) degradation. Tannic acid (TA) has been proposed to have multiple beneficial effects, including anti-inflammatory, anti-oxidant, and anti-tumor activities. However, it is unclear whether TA plays a role in anti-IL-1ß activity by blocking IL-1ß-IL-1R1 interaction in OA. In this study, we report the anti-IL-1ß activity of TA in the progression of OA in both in vitro human OA chondrocytes and in vivo rat OA models. Herein, using-ELISA-based screening, natural compound candidates capable of inhibiting the IL-1ß-IL-1R1 interaction were identified. Among selected candidates, TA showed hindering IL-1ß-IL-1R1 interaction by direct binding to IL-1ß using surface plasmon resonance (SPR) assay. In addition, TA inhibited IL-1ß bioactivity in HEK-Blue IL-1-dependent reporter cell line. TA also inhibited IL-1ß-induced expression of inducible nitric oxide synthase (NOS2), cyclooxygenase-2 (COX-2), IL-6, tumor necrosis factor-alpha (TNF-α), nitric oxide (NO), and prostaglandin E2 (PGE2) in human OA chondrocytes. Moreover, TA downregulated IL-1ß-stimulated matrix metalloproteinase (MMP)3, MMP13, ADAM metallopeptidase with thrombospondin type 1 motif (ADAMTS)4, and ADAMTS5, while upregulating collagen type II (COL2A1) and aggrecan (ACAN). Mechanistically, we confirmed that TA suppressed IL-1ß-induced MAPK and NF-κB activation. The protective effects of TA were also observed in a monosodium iodoacetamide (MIA)-induced rat OA model by reducing pain and cartilage degradation and inhibiting IL-1ß-mediated inflammation. Collectively, our results provide evidence that TA plays a potential role in OA and IL-1ß-related diseases by hindering IL-1ß-IL-1R1 interaction and suppressing IL-1ß bioactivity.

Induction of liver transplant immune tolerance in an outbred rat strain model using tacrolimus.

BACKGROUND: Orthotopic liver transplantation is the only option for patients with end-stage liver disease and hepatocellular carcinoma. Post-transplant immunosuppressive therapy is important to prevent graft failure. We investigated the effectiveness of tacrolimus (FK506) and their mechanisms for liver transplant immune tolerance in an outbred rat LT model. RESULTS: To investigate the therapeutic effect of the FK506 on outbred rat LT model, FK506 and postoperative therapy were administered subcutaneously once or twice daily to transplanted rats. Histopathological and immunohistochemical analyses were conducted for all groups. The regulation of inflammatory cytokine signaling in the spleen was analyzed by flow cytometry. FK506 attenuated allograft rejection and increased survival in rat orthotopic liver transplantation models. The FK506-treated group had reduced serum levels of alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase. Furthermore, FK506 decreased the expression of inflammatory cytokines and the activation of pathogenic Th1 and Th17 cells in the liver. CONCLUSIONS: Taken together, we revealed that FK506 ameliorated strong allograft rejection in outbred liver transplantation model by anti-inflammatory effect and inhibitory peroperty of pathogenic T cells.

Rebamipide treatment ameliorates obesity phenotype by regulation of immune cells and adipocytes.

Obesity is a medical term used to describe an over-accumulation of adipose tissue. It causes abnormal physiological and pathological processes in the body. Obesity is associated with systemic inflammation and abnormalities in immune cell function. Rebamipide, an amino acid derivative of 2-(1H)-quinolinone, has been used as a therapeutic for the protection from mucosal damage. Our previous studies have demonstrated that rebamipide treatment regulates lipid metabolism and inflammation, leading to prevention of weight gain in high-fat diet mice. In this study, mice were put on a high calorie diet for 11 weeks while receiving injections of rebamipide. Rebamipide treatment reduced the body weight, liver weight and blood glucose levels compared to control mice and reduced both glucose and insulin resistance. Fat accumulation has been shown to cause pro-inflammatory activity in mice. Treatment with rebamipide decreased the prevalence of inflammatory cells such as Th2, Th17 and M1 macrophages and increased anti-inflammatory Treg and M2 macrophages in epididymal fat tissue. Additionally, rebamipide addition inhibited adipocyte differentiation in 3T3-L1 cell lines. Taken together, our study demonstrates that rebamipide treatment is a novel and effective method to prevent diet-induced obesity.

Lactobacillus (LA-1) and butyrate inhibit osteoarthritis by controlling autophagy and inflammatory cell death of chondrocytes.

Osteoarthritis (OA) reduces the quality of life as a result of the pain caused by continuous joint destruction. Inactivated Lactobacillus (LA-1) ameliorated osteoarthritis and protected cartilage by modulating inflammation. In this study, we evaluated the mechanism by which live LA-1 ameliorated OA. To investigate the effect of live LA-1 on OA progression, we administered LA-1 into monosodium iodoacetate (MIA)-induced OA animals. The pain threshold, cartilage damage, and inflammation of the joint synovial membrane were improved by live LA-1. Furthermore, the analysis of intestinal tissues and feces in the disease model has been shown to affect the systems of the intestinal system and improve the microbiome environment. Interestingly, inflammation of the intestinal tissue was reduced, and the intestinal microbiome was altered by live LA-1. Live LA-1 administration led to an increase in the level of Faecalibacterium which is a short-chain fatty acid (SCFA) butyrate-producing bacteria. The daily supply of butyrate, a bacterial SCFA, showed a tendency to decrease necroptosis, a type of abnormal cell death, by inducing autophagy and reversing impaired autophagy by the inflammatory environment. These results suggest that OA is modulated by changes in the gut microbiome, suggesting that activation of autophagy can reduce aberrant cell death. In summary, live LA-1 or butyrate ameliorates OA progression by modulating the gut environment and autophagic flux. Our findings suggest the regulation of the gut microenvironment as a therapeutic target for OA.

Ezetimibe ameliorates clinical symptoms in a mouse model of ankylosing spondylitis associated with suppression of Th17 differentiation.

Ankylosing spondylitis (AS) is a chronic inflammatory disease that causes spinal inflammation and fusion. Although the cause of AS is unknown, genetic factors (e.g., HLA-B27) and environmental factors (e.g., sex, age, and infection) increase the risk of AS. Current treatments for AS are to improve symptoms and suppress disease progression. There is no way to completely cure it. High blood cholesterol and lipid levels aggravate the symptoms of autoimmune diseases. We applied hyperlipidemia drugs ezetimibe and rosuvastatin to AS mice and to PBMCs from AS patients. Ezetimibe and rosuvastatin was administered for 11 weeks to AS model mice on the SKG background. Then, the tissues and cells of mice were performed using flow cytometry, computed tomography, immunohistochemistry, and immunofluorescence. Also, the normal mouse splenocytes were cultured in Th17 differentiation conditions for in vitro analysis such as flow cytometry, ELISA and RNA sequencing. The 10 AS patients' PBMCs were treated with ezetimibe and rosuvastatin. The patients' PBMC were analyzed by flow cytometry and ELISA for investigation of immune cell type modification. Ezetimibe caused substantial inhibition for AS. The present study showed that ezetimibe inhibits Th17 cell function, thereby slowing the progression of AS. It is well known that statins are more effective in reducing blood lipid concentrations than ezetimibe, however, our results that ezetimibe had a better anti-inflammatory effect than rosuvastatin in AS. This data suggests that ezetimibe has an independent anti-inflammatory effect independent of blood lipid reduction. To investigate whether ezetimibe has its anti-inflammatory effect through which signaling pathway, various in vitro experiments and RNA sequencing have proceeded. Here, this study suggests that ezetimibe can be an effective treatment for AS patients by inhibiting Th17 differentiation-related genes such as IL-23R and IL-1R. Thus, this study suggests that ezetimibe has therapeutic potential for AS through inhibition of Th17 differentiation and the production of pro-inflammatory cytokines.

Vitamin D Attenuates Pain and Cartilage Destruction in OA Animals via Enhancing Autophagic Flux and Attenuating Inflammatory Cell Death.

Osteoarthritis (OA) is the most common form of arthritis associated with ageing. Vitamin D has diverse biological effect on bone and cartilage, and observational studies have suggested it potential benefit in OA progression and inflammation process. However, the effect of vitamin D on OA is still contradictory. Here, we investigated the therapeutic potential of vitamin D in OA. Six-week-old male Wistar rats were injected with monosodium iodoacetate (MIA) to induce OA. Pain severity, cartilage destruction, and inflammation were measured in MIA-induced OA rats. Autophagy activity and mitochondrial function were also measured. Vitamin-D (1,25(OH)2D3) and celecoxib were used to treat MIA-induced OA rats and OA chondrocytes. Oral supplementation of vitamin D resulted in significant attenuations in OA pain, inflammation, and cartilage destruction. Interestingly, the expressions of MMP-13, IL-1ß, and MCP-1 in synovial tissues were remarkably attenuated by vitamin D treatment, suggesting its potential to attenuate synovitis in OA. Vitamin D treatment in OA chondrocytes resulted in autophagy induction in human OA chondrocytes and increased expression of TFEB, but not LC3B, caspase-1 and -3, in inflamed synovium. Vitamin D and celecoxib showed a synergistic effect on antinociceptive and chondroprotective properties in vivo. Vitamin D showed the chondroprotective and antinociceptive property in OA rats. Autophagy induction by vitamin D treatment may be a promising treatment strategy in OA patients especially presenting vitamin D deficiency. Autophagy promoting strategy may attenuate OA progression through protecting cells from damage and inflammatory cell death.

Soluble CCR2 gene therapy controls joint inflammation, cartilage damage, and the progression of osteoarthritis by targeting MCP-1 in a monosodium iodoacetate (MIA)-induced OA rat model.

BACKGROUND: Osteoarthritis (OA) is the most common type of degenerative arthritis and affects the entire joint, causing pain, joint inflammation, and cartilage damage. Various risk factors are implicated in causing OA, and in recent years, a lot of research and interest have been directed toward chronic low-grade inflammation in OA. Monocyte chemoattractant protein-1 (MCP-1; also called CCL2) acts through C-C chemokine receptor type 2 (CCR2) in monocytes and is a chemotactic factor of monocytes that plays an important role in the initiation of inflammation. The targeting of CCL2-CCR2 is being studied as part of various topics including the treatment of OA. METHODS: In this study, we evaluated the potential therapeutic effects the sCCR2 E3 gene may exert on OA. The effects of sCCR2 E3 were investigated in animal experiments consisting of intra-articular injection of sCCR2 E3 in a monosodium iodoacetate (MIA)-induced OA rat model. The effects after intra-articular injection of sCCR2 E3 (fusion protein encoding 20 amino acids of the E3 domain of the CCL2 receptor) in a monosodium iodoacetate-induced OA rat model were compared to those in rats treated with empty vector (mock treatment) and full-length sCCR2. RESULTS: Pain improved with expression of the sCCR2 gene. Improved bone resorption upon sCCR2 E3 gene activation was confirmed via bone analyses using micro-computed tomography. Histologic analyses showed that the sCCR2 E3 gene exerted protective effects against cartilage damage and anti-inflammatory effects on joints and the intestine. CONCLUSIONS: These results show that sCCR2 E3 therapy is effective in reducing pain severity, inhibiting cartilage destruction, and suppressing intestinal damage and inflammation. Thus, sCCR2 E3 may be a potential therapy for OA.

A decrease in functional microbiomes represented as Faecalibacterium affects immune homeostasis in long-term stable liver transplant patients.

ABBREVIATIONS: LT, liver transplantation; HCC, hepatocellular carcinoma; IS, immunosuppressants; DC, dendritic cells; Treg, regulatory T; Th17, T helper 17; AST, aspartate transaminase; ALT, alanine transaminase; OUT, operational taxonomic unit; LEfSe, linear discriminant analysis effect size; LDA, linear discriminant analysis; IL, interleukin; TGF, transforming growth factor; GM-CSF, granulocyte-macrophage colony-stimulating factor; IFN, interferon; TNF-α, tumor necrosis factor-α; MIP-1α, macrophage inflammatory protein-1α; IP-10, interferon γ-induced protein; MCP-1, monocyte chemoattractant protein-1; ACR, acute cellular rejection; NF-κB, nuclear factor κB; PT INR, prothrombin time; QC, quality check; PBMC, peripheral blood mononuclear cells; PBS, phosphate-buffered saline; ELISA, enzyme-linked immunosorbent assay.

IL-17 Induces Autophagy Dysfunction to Promote Inflammatory Cell Death and Fibrosis in Keloid Fibroblasts via the STAT3 and HIF-1α Dependent Signaling Pathways.

Keloid is an abnormal fibrotic disease after cutaneous injury characterized by exaggerated scar tissue formation, which often extends beyond the boundaries of the original wound. Although chronic inflammation is known to be associated with the excessive inflammation in keloid tissue, there are few studies on the role of autophagy in the pathogenesis of keloid. In this study, we evaluated the pattern of autophagy in keloid fibroblasts (KF) and normal fibroblasts (NF). Expression of HIF-1α, STAT3 and autophagic flux markers were evaluated in KF and NF. Defective autophagy caused by IL-17 was evaluated, and the relationship between defective autophagy and necroptosis was also examined. The expression of IL-17, HIF-1α and STAT3 was significantly increased in keloid tissue, and autophagosome-to autophagolysosome conversion was defective in KF. IL-17 treatment significantly elevated the expression of STAT3 and HIF-1α in NF and caused defective autophagy, which was reversed by HIF-1α inhibitor. In addition, the defective autophagy was associated with the increased necroptosis and fibrosis. In keloid tissue, the elevated necroptosis marker was confirmed, and with the HIF-1α inhibitor, the defective autophagy, necroptosis and fibrosis was decreased in KF. In conclusion, autophagy was defective in keloid tissue, which was associated with increased necroptosis and fibrosis. The IL-17-STAT3-HIF-1α axis was involved in defective autophagy in KF, and this suggests that targeting the axis could alleviate chronic inflammation in keloid disease.

Coenzyme Q10 encapsulated in micelles ameliorates osteoarthritis by inhibiting inflammatory cell death.

BACKGROUND: Osteoarthritis (OA) is the most common degenerative joint disease and is characterized by breakdown of joint cartilage. Coenzyme Q10 (CoQ10) exerts diverse biological effects on bone and cartilage; observational studies have suggested that CoQ10 may slow OA progression and inflammation. However, any effect of CoQ10 on OA remains unclear. Here, we investigated the therapeutic utility of CoQ10-micelles. METHODS: Seven-week-old male Wistar rats were injected with monosodium iodoacetate (MIA) to induce OA. CoQ10-micelles were administered orally to MIA-induced OA rats; celecoxib served as the positive control. Pain, tissue destruction, and inflammation were measured. The expression levels of catabolic and inflammatory cell death markers were assayed in CoQ10-micelle-treated chondrocytes. RESULTS: Oral supplementation with CoQ10-micelles attenuated OA symptoms remarkably, including pain, tissue destruction, and inflammation. The expression levels of the inflammatory cytokines IL-1ß, IL-6, and MMP-13, and of the inflammatory cell death markers RIP1, RIP3, and pMLKL in synovial tissues were significantly reduced by CoQ10-micelle supplementation, suggesting that CoQ10-micelles might attenuate the synovitis of OA. CoQ10-micelle addition to cultured OA chondrocytes reduced the expression levels of catabolic and inflammatory cell death markers. CONCLUSIONS: CoQ10-micelles might usefully treat OA.

Sphingosylphosphorylcholine ameliorates experimental sjögren's syndrome by regulating salivary gland inflammation and hypofunction, and regulatory B cells.

Sjögren syndrome (SS) is an autoimmune disease in which immune cells infiltrate the exocrine gland. Since SS is caused by a disorder of the immune system, treatments should regulate the immune response. Sphingosylphosphorylcholine (SPC) is a sphingolipid that mediates cellular signaling. In immune cells, SPC has several immunomodulatory functions. Accordingly, this study verifies the immunomodulatory ability and therapeutic effect of SPC in SS. To understand the function of SPC in SS, we treated SPC in female NOD/ShiJcl (NOD) mice. The mice were monitored for 10 weeks, and inflammation in the salivary glands was checked. After SPC treatment, we detected the expression of regulatory B (Breg) cells in mouse splenocytes and the level of salivary secretion-related genes in human submandibular gland (HSG) cells. Salivary flow rate was maintained in the SPC-treated group compared to the vehicle-treated group, and inflammation in the salivary gland tissues was relieved by SPC. SPC treatment in mouse cells and HSG cells enhanced Breg cells and salivary secretion markers, respectively. This study revealed that SPC can be considered as a new therapeutic agent against SS.

Mitochondrial Transplantation Ameliorates the Development and Progression of Osteoarthritis.

Osteoarthritis (OA) is a common degenerative joint disease characterized by breakdown of joint cartilage. Mitochondrial dysfunction of the chondrocyte is a risk factor for OA progression. We examined the therapeutic potential of mitochondrial transplantation for OA. Mitochondria were injected into the knee joint of monosodium iodoacetate-induced OA rats. Chondrocytes from OA rats or patients with OA were cultured to examine mitochondrial function in cellular pathophysiology. Pain, cartilage destruction, and bone loss were improved in mitochondrial transplanted-OA rats. The transcript levels of IL-1ß, TNF-α, matrix metallopeptidase 13, and MCP-1 in cartilage were markedly decreased by mitochondrial transplantation. Mitochondrial function, as indicated by membrane potential and oxygen consumption rate, in chondrocytes from OA rats was improved by mitochondrial transplantation. Likewise, the mitochondrial function of chondrocytes from OA patients was improved by coculture with mitochondria. Furthermore, inflammatory cell death was significantly decreased by coculture with mitochondria. Mitochondrial transplantation ameliorated OA progression, which is caused by mitochondrial dysfunction. These results suggest the therapeutic potential of mitochondrial transplantation for OA.

Methotrexate-loaded nanoparticles ameliorate experimental model of autoimmune arthritis by regulating the balance of interleukin-17-producing T cells and regulatory T cells.

BACKGROUND: Rheumatoid arthritis (RA) is a progressive systemic autoimmune disease that is characterized by infiltration of inflammatory cells into the hyperplastic synovial tissue, resulting in subsequent destruction of adjacent articular cartilage and bone. Methotrexate (MTX), the first conventional disease-modifying antirheumatic drug (DMARD), could alleviate articular damage in RA and is implicated in humoral and cellular immune responses. However, MTX has several side effects, so efficient delivery of low-dose MTX is important. METHODS: To investigate the efficacy of MTX-loaded nanoparticles (MTX-NPs) against experimental model of RA, free MTX or MTX-NPs were administered as subcutaneous route to mice with collagen-induced arthritis (CIA) at 3 weeks after CII immunization. The levels of inflammatory factors in tissues were determined by immunohistochemistry, confocal microscopy, real-time PCR, and flow cytometry. RESULTS: MTX-NPs ameliorated arthritic severity and joint destruction in collagen-induced arthritis (CIA) mice compared to free MTX-treated CIA mice. The levels of inflammatory cytokines, including interleukin (IL)-1ß, tumor necrosis factor-α, and vascular endothelial growth factor, were reduced in MTX-NPs-treated mice. Number of CD4 + IL-17 + cells decreased whereas the number of CD4 + CD25 + Foxp3 + cells increased in spleens from MTX- NPs-treated CIA mice compared to MTX-treated CIA mice. The frequency of CD19 + CD25 + Foxp3 + regulatory B cells increased in ex vivo splenocytes from MTX-loaded NPs-treated CIA mice compared to MTX-treated CIA mice. CONCLUSION: The results suggest that MTX-loaded NPs have therapeutic potential for RA.

Therapeutic Potential of a Novel Bifidobacterium Identified Through Microbiome Profiling of RA Patients With Different RF Levels.

The potential therapeutic effects of probiotic bacteria in rheumatoid arthritis (RA) remain controversial. Thus, this study aimed to discover potential therapeutic bacteria based on the relationship between the gut microbiome and rheumatoid factor (RF) in RA. Bacterial genomic DNA was extracted from the fecal samples of 93 RA patients and 16 healthy subjects. Microbiota profiling was conducted through 16S rRNA sequencing and bioinformatics analyses. The effects of Bifidobacterium strains on human peripheral blood mononuclear cells and collagen-induced arthritis (CIA) mice were assessed. Significant differences in gut microbiota composition were observed in patients with different RF levels. The relative abundance of Bifidobacterium and Collinsella was lower in RF-high than in RF-low and RF-negative RA patients, while the relative abundance of Clostridium of Ruminococcaceae family was higher in RF-high than in RF-low and RF-negative patients. Among 10 differentially abundant Bifidobacterium, B. longum RAPO exhibited the strongest ability to inhibit IL-17 secretion. Oral administration of B. longum RAPO in CIA mice, obese CIA, and humanized avatar model significantly reduced RA incidence, arthritis score, inflammation, bone damage, cartilage damage, Th17 cells, and inflammatory cytokine secretion. Additionally, B. longum RAPO significantly inhibited Th17 cells and Th17-related genes-IL-17A, IRF4, RORC, IL-21, and IL-23R-in the PBMCs of rheumatoid arthritis patients. Our findings suggest that B. longum RAPO may alleviate RA by inhibiting the production of IL-17 and other proinflammatory mediators. The safety and efficacy of B. longum RAPO in patients with RA and other autoimmune disorders merit further investigation.

A green-lipped mussel reduces pain behavior and chondrocyte inflammation and attenuated experimental osteoarthritis progression.

The green-lipped mussel (GLM) contains novel omega-3 polyunsaturated fatty acids, which exhibit anti-inflammatory and joint-protecting properties. Osteoarthritis (OA) is a degenerative joint disease characterized by a progressive loss of cartilage; oxidative stress plays a role in the pathogenesis of OA. The objectives of this study were to investigate the in vivo effects of the GLM on pain severity and cartilage degeneration using an experimental rat OA model, and to explore the mode of action of GLM. OA was induced in rats by intra-articular injection of monosodium iodoacetate (MIA) into the knee. Oral GLM was initiated on the day after 3dyas of MIA injection. Limb nociception was assessed by measuring the paw withdrawal latency and threshold. Samples were analyzed both macroscopically and histologically. Immunohistochemistry was used to investigate the expression of interleukin-1ß (IL-1ß), IL-6, nitrotyrosine, and inducible nitric oxide synthase (iNOS) in knee joints. Also, the GLM was applied to OA chondrocyte, and the expression on catabolic marker and necroptosis factor were evaluated by real-time polymerase chain reaction. Administration of the GLM improved pain levels by preventing cartilage damage and inflammation. GLM significantly attenuated the expression levels of mRNAs encoding matrix metalloproteinase-3 (MMP-3), MMP-13, and ADAMTS5 in IL-1ß-stimulated human OA chondrocytes. GLM decreased the expression levels of the necroptosis mediators RIPK1, RIPK3, and the mixed lineage kinase domain-like protein (MLKL) in IL-1ß-stimulated human OA chondrocytes. Thus, GLM reduced pain and cartilage degeneration in rats with experimentally induced OA. The chondroprotective properties of GLM included suppression of oxidative damage and inhibition of catabolic factors implicated in the pathogenesis of OA cartilage damage. We suggest that GLM may usefully treat human OA.

Metformin-Inducible Small Heterodimer Partner Interacting Leucine Zipper Protein Ameliorates Intestinal Inflammation.

Small heterodimer partner interacting leucine zipper protein (SMILE) is an orphan nuclear receptor and a member of the bZIP family of proteins. We investigated the mechanism by which SMILE suppressed the development of inflammatory bowel disease (IBD) using a DSS-induced colitis mouse model and peripheral blood mononuclear cells (PBMCs) from patients with ulcerative colitis (UC). Metformin, an antidiabetic drug and an inducer of AMPK, upregulated the level of SMILE in human intestinal epithelial cells and the number of SMILE-expressing cells in colon tissues from DSS-induced colitis mice compared to control mice. Overexpression of SMILE using a DNA vector reduced the severity of DSS-induced colitis and colitis-associated intestinal fibrosis compared to mock vector. Furthermore, SMILE transgenic mice showed ameliorated DSS-induced colitis compared with wild-type mice. The mRNA levels of SMILE and Foxp3 were downregulated and SMILE expression was positively correlated with Foxp3 in PBMCs from patients with UC and an inflamed mucosa. Metformin increased the levels of SMILE, AMPK, and Foxp3 but decreased the number of interleukin (IL)-17-producing T cells among PBMCs from patients with UC. These data suggest that SMILE exerts a therapeutic effect on IBD by modulating IL-17 production.

Oral Administration of Lactobacillus rhamnosus Ameliorates the Progression of Osteoarthritis by Inhibiting Joint Pain and Inflammation.

Osteoarthritis (OA) is the most common form of arthritis and age-related degenerative joint disorder, which adversely affects quality of life and causes disability. However, the pathogenesis of OA remains unclear. This study was performed to examine the effects of Lactobacillus rhamnosus in OA progression. OA was induced in 6-week-old male Wistar rats by monosodium iodoacetate (MIA) injection, and the effects of oral administration of L. rhamnosus were examined in this OA rat model. Pain severity, cartilage destruction, and inflammation were measured in MIA-induced OA rats. The small intestines were isolated from OA rats, and the intestinal structure and inflammation were measured. Protein expression in the dorsal root ganglion was analyzed by immunohistochemistry. The effects of L. rhamnosus on mRNA and protein expression in chondrocytes stimulated with interleukin (IL)-1ß and lipopolysaccharide (LPS) were analyzed by real-time polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). Pain severity was decreased in L. rhamnosus-treated MIA-induced OA rats. The levels of expression of MCP-1, a potential inflammatory cytokine, and its receptor, CCR2, were decreased, and GABA and PPAR-γ expression were increased in L. rhamnosus-treated OA rats. The inflammation, as determined by IL-1ß, and cartilage destruction, as determined by MMP3, were also significantly decreased by L. rhamnosus in OA rats. Additionally, intestinal damage and inflammation were improved by L. rhamnosus. In human OA chondrocytes, TIMP1, TIMP3, SOX9, and COL2A1 which are tissue inhibitors of MMP, and IL-10, an anti-inflammatory cytokine, were increased by L. rhamnosus. L. rhamnosus treatment led to decreased pain severity and cartilage destruction in a rat model of OA. Intestinal damage and inflammation were also decreased by L. rhamnosus treatment. Our findings suggested the therapeutic potential of L. rhamnosus in OA.

Metformin Attenuates Monosodium-Iodoacetate-Induced Osteoarthritis via Regulation of Pain Mediators and the Autophagy-Lysosomal Pathway.

Osteoarthritis (OA) is the most common degenerative arthritis associated with pain and cartilage destruction in the elderly; it is known to be involved in inflammation as well. A drug called celecoxib is commonly used in patients with osteoarthritis to control pain. Metformin is used to treat type 2 diabetes but also exhibits regulation of the autophagy pathway. The purpose of this study is to investigate whether metformin can treat monosodium iodoacetate (MIA)-induced OA in rats. Metformin was administered orally every day to rats with OA. Paw-withdrawal latency and threshold were used to assess pain severity. Cartilage damage and pain mediators in dorsal root ganglia were evaluated by histological analysis and a scoring system. Relative mRNA expression was measured by real-time PCR. Metformin reduced the progression of experimental OA and showed both antinociceptive properties and cartilage protection. The combined administration of metformin and celecoxib controlled cartilage damage more effectively than metformin alone. In chondrocytes from OA patients, metformin reduced catabolic factor gene expression and inflammatory cell death factor expression, increased LC3Ⅱb, p62, and LAMP1 expression, and induced an autophagy-lysosome fusion phenotype. We investigated if metformin treatment reduces cartilage damage and inflammatory cell death of chondrocytes. The results suggest the potential for the therapeutic use of metformin in OA patients based on its ability to suppress pain and protect cartilage.

Liposome/gold hybrid nanoparticle encoded with CoQ10 (LGNP-CoQ10) suppressed rheumatoid arthritis via STAT3/Th17 targeting.

Coenzyme Q10 (CoQ10), also known as ubiquinone, is a fat-soluble antioxidant. Although CoQ10 has not been approved as medication by the Food and Drug Administration, it is widely used in dietary supplements. Some studies have shown that CoQ10 has anti-inflammatory effects on various autoimmune disorders. In this study, we investigated the anti-inflammatory effects of liposome/gold hybrid nanoparticles encoded with CoQ10 (LGNP-CoQ10). Both CoQ10 and LGNP-CoQ10 were administered orally to mice with collagen-induced arthritis (CIA) for 10 weeks. The inflammation pathology of joint tissues of CIA mice was then analyzed using hematoxylin and eosin and Safranin O staining, as well as immunohistochemistry analysis. We obtained immunofluorescence staining images of spleen tissues using confocal microscopy. We found that pro-inflammatory cytokines were significantly decreased in LGNP-CoQ10 injected mice. Th17 cell and phosphorylated STAT3-expressed cell populations were also decreased in LGNP-CoQ10 injected mice. When human peripheral blood mononuclear cells (PBMCs) were treated with CoQ10 and LGNP-CoQ10, the IL-17 expression of PBMCs in the LGNP-CoQ10-treated group was significantly reduced. Together, these results suggest that LGNP-CoQ10 has therapeutic potential for the treatment of rheumatoid arthritis.