• IMMUNE NETWORK
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• v.22 no.2
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• pp.14.1-14.17
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• 2022

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-1β, 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.

• IMMUNE NETWORK
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• v.7 no.1
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• pp.39-47
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• 2007

Background: Stromal cell-derived factor (SDF)-1 is a potent chemoattractant for activated T cells into the inflamed Rheumatoid arthritis (RA) synovium. To determine the effect of macrophage migration inhibitory factor (MIF) on the production of SDF-1 in the inflamed RA synovium. Methods: The expression of SDF-1 and MIF in RA and Osteoarthritis (OA) synovium was examined by immunohistochemical staining. The SDF-1 was quantified by RT-PCR and ELISA after RA fibroblast like synoviocyte (FLS) were treated with MIF in the presence and absence of inhibitors of intracellular signal molecules. The synovial fluid (SF) and serum levels of MIF and SDF-1 in RA, OA and healthy control were measured by ELISA. Results: Expression of SDF-1 and MIF in synovium was higher in RA patients than in OA patients. The production of SDF-1 was enhanced in RA FLS by MIF stimulation. Such effect of MIF was blocked by the inhibitors of NF-${\kappa}B$. Concentrations of SDF-1 in the serum and SF were higher in RA patients than in OA patients and healthy control. SDF-1 and MIF was overexpressed in RA FLS, and MIF could up-regulate the production of SDF-1 in RA FLS via NF-${\kappa}B$-mediated pathways. Conclusion: These results suggest that an inhibition of interaction between MIF from T cells and SDF-1 of FLS may provide a new therapeutic approach in the treatment of RA.

• IMMUNE NETWORK
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• v.20 no.5
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• pp.39.1-39.13
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• 2020

Sjögren's syndrome (SS) is a chronic and systemic autoimmune disease characterized by lymphocytic infiltration in the exocrine glands. In SS, type I IFN has a pathogenic role, and recently, inflammasome activation has been observed in both immune and non-immune cells. However, the relationship between type I IFN and inflammasome-associated pyroptosis in SS has not been studied. We measured IL-18, caspase-1, and IFN-stimulated gene 15 (ISG15) in saliva and serum, and compared whether the expression levels of inflammasome and pyroptosis components, including absent in melanoma 2 (AIM2), NLR family pyrin domain containing 3 (NLRP3), apoptosis-associated speck-like protein (ASC), caspase-1, gasdermin D (GSDMD), and gasdermin E (GSDME), in minor salivary gland (MSG) are related to the expression levels of type I IFN signature genes. Expression of type I IFN signature genes was correlated with mRNA levels of caspase-1 and GSDMD in MSG. In confocal analysis, the expression of caspase-1 and GSDMD was higher in salivary gland epithelial cells (SGECs) from SS patients. In the type I IFN-treated human salivary gland epithelial cell line, the expression of caspase-1 and GSDMD was increased, and pyroptosis was accelerated in a caspase-dependent manner upon inflammasome activation. In conclusion, we demonstrate that type I IFN may contribute to inflammasome-associated pyroptosis of the SGECs of SS patients, suggesting another pathogenic role of type I IFN in SS in terms of target tissue -SGECs destruction.

• IMMUNE NETWORK
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• v.5 no.4
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• pp.221-231
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• 2005

Background: Immune regulatory dendritic cells (DCs) play an important role in maintaining self-tolerance. Recent evidences demonstrate that DCs expressing indoleamine 2,3-dioxygenase (IDO), which is involved in tryptophan catabolism, play an important role in immunoregulation and tolerance and induce T cell apoptosis. This study was devised to examine the role of IDO in the oral tolerance induction in collagen-induced arthritis (CIA) mouse model. Methods: Beginning 2 weeks before immunization, CII was fed six times to DBA/1 mice and the effect on arthritis was assessed. In tolerized mice, $CD11c^+$ DCs were isolated and stimulated with CII, IFN-${\gamma}$, and LPS with or without IDO inhibitor, 1-methyl-DL-tryptophan (1-MT) and IDO expression by $CD11c^+$ DCs was analyzed using FACS and RT-PCR. The expression of IDO, MHC II, CD80, and CD86 by $CD11c^+$ DCs were examined using confocal microscopy. Regulatory effect of $CD11c^+$ DCs on Ag-specific T cell proliferative response to CII was examined by mixed lymphocyte reaction (MLR) with or without 1-MT. Results: The proportion of IDO-expressing $CD11c^+$ DCs was slightly higher in tolerized mice than in CIA mice and significantly increased after stimulation with CII, IFN-${\gamma}$, and LPS in an IDO-dependent manner. On confocal microscopic examination, the expression of IDO was higher and those of MHC II and CD86 were lower in CD11c + DCs from tolerized mice compared to those from CIA mice. On MLR, $CD11c^+$ DCs from tolerized mice inhibited T cell proliferative response to CII in an IDO-dependent manner. Conclusion: Enhanced IDO expression by $CD11c^+$ DCs from tolerized mice may contribute to the regulation of proliferative response of CII-reactive T cells and could be involved in the induction of oral tolerance to CII.

• IMMUNE NETWORK
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• v.3 no.2
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• pp.136-144
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• 2003

Oral administration of antigen has long been considered as a promising alternative for the treatment of chronic autoimmune diseases including rheumatoid arthritis (RA), and oral application of type II collagen (CII) has been proven to improve pathogenic symptoms in RA patients without problematic side effects. To further current understandings about the immune suppression mechanisms mediated by orally administered antigens, we examined the changes in IgG subtypes, T-cell proliferative response, and proportion of interleukin (IL)-10 producing Th subsets in a time course study of collagen induced arthritis (CIA) animal models. We found that joint inflammation in CIA mouse peaked at 5 weeks after first immunization with CII, which was significantly subdued in mice pre-treated by repeated oral administration of CII. Orally tolerized mice also showed increase in their serum level of IgG1, while the level of IgG2a was decreased. T-cell proliferation upon CII stimulation was also suppressed in lymph nodes of mice given oral administration of CII compared to non-tolerized controls. When cultured in vitro in the presence of CII, T-cells isolated from orally tolerized mice presented higher proportion of $CD4^+IL-10^+$ subsets compared to non-tolerized controls. Interestingly, such increase in IL-10 producing cells were obvious first in Peyer's patch, then by 5 weeks after immunization, in mesenteric lymph node and spleen instead. This result indicates that a particular subset of T-cells with immune suppressive functions might have migrated from the original contact site with CII to inflamed joints via peripheral blood after 5 weeks post immunization.

• The Journal of Korean Medicine
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• v.16 no.1 s.29
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• pp.9-20
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• 1995

I would like to state my own opinion on arthralgia syndrome(痺病) through the literatural studies. First of all, arthralgia symdrome(痺病) must be classified into six type basically, which are migratory arthralgia(痺病(行痺)), arthritis of heat type(濕痺), arthritis due to blood stasis(瘀血痺) and deficient rheumatism(虛痺), and then could be considered to try the compound names of arthralgia syndrome. These can come from according to the rise and decline of causes in wind(風), cold(寒), damp(濕), heat(熱), blood stasis(瘀血) and qi-blood(氣血). For example, it would be possible to apply the wind-dampness rheymatism(風濕痺) of damp-heat rheumatism(濕熱痺) in terminology of arthralgia syndrome(痺病). As rheumatoid arthritis(歷節風), rheumatoid arthritis like white tiger bite (白虎歷節風) and gout (痛風) not to mean the gout in western medicine have been announced a kind of arthralgia syndromes(痺病) by many doctors since Ming dynasty(明代) and proved it to be true, it is reasonabie not to try it any longer. And tingling and deficiency of sensation(廢木 不仁) is a symptome showing the decline of muscle power including mainly the abnormal sensation of skin, it would be recommended to be classified into fliaccidity syndrome(?痺). And then the names rheumatism invoiving lendon and ligament(筋痺), rheumatism involving blood vessels(脈痺), rheumatism involving muscle(肌痺), numbness of skin (皮痺) and rheumatism involving bone(骨痺), which have been used as the classification title with the season be received bad-qi(邪氣), must be classlfied to the location appearing aymptomes. Though obstruction of the liver-qi(肝痺), obstruction of the heart-qi(心痺), stagnation of the spleen-qi(脾痺), stagnation of the lung-qi(肺痺), stagnation of the kidney-qi(腎痺) and dysfunction of the bladder(胞痺) that used visceral and bladder name, that stated a kind of arthralgia syndrome(痺病), but it must be classified into a different diseases from arthragia syndrome.

• IMMUNE NETWORK
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• v.3 no.4
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• pp.310-319
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• 2003

Inflammatory mediators has been recognized as an important role in the pathogenesis of rheumatoid arthritis (RA). IL-17 is increasingly recognized as an important regulator of immune and inflammatory responses, including induction of proinflammatory cytokines and osteoclastic bone resorption. Evidence of the expression and proinflammatory activity of IL-17 has been demonstrated in RA synovium and in animal models of RA. However, the signaling pathways that regulate IL-17 production remain unknown. In the present study, we investigated the role of the phosphatidylinositol 3 kinase (PI3K)-Akt pathway in the regulation of IL-17 production in RA. PBMC were separated from RA (n=24) patients, and stimulated with various agents (anti CD3, anti CD28, PHA, ConA, IL-15). IL-17 levels were determined by sandwich ELISA and RT-PCR. The production of IL-17 was significantly increased in cells treated with anti-CD3 antibody, PHA, IL-15 or MCP-1 (P<0.05). ConA also strongly induced IL-17 production (P<0.001), whereas TNF-alpha, IL-1beta, IL-18 or TGF-beta did not. IL-17 was detected in the PBMC of patients with osteoarthritis (OA) but their expression levels were much lower than those of RA PBMC. Anti-CD3 antibody activated the PI3K-Akt pathway and activation of the PI3K-Akt pathway resulted in a pronounced augmentation of nuclear factor kappaB ($NF-{\kappa}B$). IL-17 production by activated PBMC in RA is completely or partially blocked in the presence of $NF-{\kappa}B$ inhibitor PDTC and PI3K-Akt inhibitor, wortmannin and LY294002, respectively. Whereas the inhibition of AP-1 and extracellular signal-regulated kinase (ERK)1/2 did not affect IL-17 production. These results provide new insight into that PI3K/Akt and $NF-{\kappa}B$ dependent signal transduction pathway could be involved in the overproduction of key inflammatory cytokine, IL-17 in rheumatoid arthritis.

• IMMUNE NETWORK
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• v.7 no.3
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• pp.124-132
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• 2007

Background: Regulatory T cells (Tregs) have been investigated intensively for some decades. These cells regulate the immune system, prevent overactivated immune responses and can be used therapeutically. For rheumatoid arthritis (RA), understanding the functions and status of Tregs is an important step for understanding immune regulation in this autoimmune disease. Methods: We investigated the percentages, phenotypes and suppressive functions of $CD4^+CD25^+$ Tregs in peripheral blood (PB) of patients with RA. Results: The percentages were higher in the patients (n=12) than in healthy controls (n=10), and the cells expressed the $CD45RB^{low}$, CTLA-4 and CCR7 phenotypes. We also investigated the expression of Foxp3 and secretion of interleukin (IL)-10 induced $CD4^+CD25^+$ Tcells by anti-CD3 antibody treatment. A suppressive function of the patients' cells was shown through coculture with $CD4^+CD25^-$ T cells in vitro. Conclusion: We suggest that, despite their increased numbers and suppressive function, they manage the ongoing inflammation ineffectively. It might be possible to apply IL-10 to induce the proliferation of IL-10-producing Tregs as therapy for RA.

• IMMUNE NETWORK
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• v.24 no.3
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• pp.15.1-15.18
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• 2024

Osteoarthritis (OA) involves cartilage degeneration, thereby causing inflammation and pain. Cardiovascular diseases, such as dyslipidemia, are risk factors for OA; however, the mechanism is unclear. We investigated the effect of dyslipidemia on the development of OA. Treatment of cartilage cells with low-density lipoprotein (LDL) enhanced abnormal autophagy but suppressed normal autophagy and reduced the activity of transcription factor EB (TFEB), which is important for the function of lysosomes. Treatment of LDL-exposed chondrocytes with rapamycin, which activates TFEB, restored normal autophagy. Also, LDL enhanced the inflammatory death of chondrocytes, an effect reversed by rapamycin. In an animal model of hyperlipidemia-associated OA, dyslipidemia accelerated the development of OA, an effect reversed by treatment with a statin, an anti-dyslipidemia drug, or rapamycin, which activates TFEB. Dyslipidemia reduced the autophagic flux and induced necroptosis in the cartilage tissue of patients with OA. The levels of triglycerides, LDL, and total cholesterol were increased in patients with OA compared to those without OA. The C-reactive protein level of patients with dyslipidemia was higher than that of those without dyslipidemia after total knee replacement arthroplasty. In conclusion, oxidized LDL, an important risk factor of dyslipidemia, inhibited the activity of TFEB and reduced the autophagic flux, thereby inducing necroptosis in chondrocytes.

• IMMUNE NETWORK
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• v.7 no.1
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• pp.10-17
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• 2007

Autoimmune arthritis, such as rheumatoid arthritis (RA), is a chronic inflammatory disorder that primarily affects the joints and then results in their progressive destruction. Effector Th cells have been classified as Th1 and Th2 subsets based on their cytokine expression profiles and immune regulatory function. Another subset of T cells termed Th17 was recendy discovered and known to selectively produce IL-17. Also, Th17 was shown to be generated by TGF${\beta}$ and IL-6 and maintained by IL-23. IL-17 is a proinflammatory cytokine that is considered to involve the development of various inflammatory autoimmune diseases such as RA, asthma, lupus, and allograft rejection. IL-17 is present in the sera, synovial fluids and synovial biopsies of most RA patient. IL-17 activates RA synovial fibroblasts to synthesize IL-6, IL-8 and VEGF via PI3K/Akt and NF-${\kappa}B$ dependent pathway. IL-17 increases IL-6 production, collagen destruction and collagen synthesis. In addition, it not only causes bone resorption but also increases osteoclastogenesis and fetal cartilage destruction. Inhibition of the IL-17 production may contribute a novel therapeutic approach along with potent anti-inflammatory effect and with less immunosuppressive effect on host defenses.