Ginkgo biloba extract ameliorates skin fibrosis in a bleomycin-induced mouse model of systemic sclerosis.

Systemic sclerosis (SSc) is a chronic autoimmune disease characterized by skin and internal organ fibrosis and obliterative vasculopathy. Few effective treatments are currently available for fibrosis in SSc, therefore, demand persists for novel therapies. Although use of Ginkgo biloba extract (GBE) has been reported to improve blood circulation and alleviate liver and lung fibrosis, its effect on skin fibrosis in SSc remains unclear. In this study, the effects and underlying mechanisms of GBE on skin fibrosis in bleomycin (BLM)-induced mouse model of SSc was investigated. GBE significantly reduced dermal thickness and protein levels of profibrotic factors in the BLM-induced SSc mouse model. Moreover, GBE inhibited the gene expression of profibrotic factors, such as COL1A1, α-SMA, and connective tissue growth factor (CTGF), in fibroblasts by suppressing transforming growth factor (TGF)-ß signaling. Furthermore, GBE inhibited the transdifferentiation of adipocytes into myofibroblasts. Thus, our findings suggest that GBE is a promising therapeutic candidate for the treatment of SSc.

FAT10 differentially stabilizes MYPT2 isoforms.

Myosin phosphatase (MP) is an enzyme complex that regulates muscle contraction and plays important roles in various physiological and pathological conditions. Myosin phosphatase targeting subunit (MYPT) 2, a subunit of MP, interacts with protein phosphatase 1c to regulate its phosphatase activity. MYPT2 exists in various isoforms that differ in the composition of essential motifs that contribute to its function. However, regulatory mechanisms underlying these isoforms are poorly understood. Human leukocyte antigen-F adjacent transcript 10 (FAT10) is a ubiquitin-like modifier that not only targets proteins for proteasomal degradation but also stabilizes its interacting proteins. In this study, we investigated the effect of the interaction between FAT10 and MYPT2 isoform a (the canonical full-length form of MYPT2) or MYPT2 isoform f (the natural truncated form of MYPT2). FAT10 interacted with both MYPT2 isoforms a and f; however, only MYPT2 isoform f was increased by FAT10, whereas MYPT2 isoform a remained unaffected by FAT10. We further confirmed that, in contrast to MYPT2 isoform a, MYPT2 isoform f undergoes rapid degradation via the ubiquitin-proteasome pathway and that FAT10 stabilizes MYPT2 isoform f by inhibiting its ubiquitination. Therefore, our findings suggest that the interaction between FAT10 and MYPT2 isoforms leads to distinct stabilization effects on each isoform, potentially modulating MP activity.

Glucose metabolic reprogramming in autoimmune diseases.

Autoimmune diseases are conditions in which the immune system mistakenly targets and damages healthy tissue in the body. In recent decades, the incidence of autoimmune diseases has increased, resulting in a significant disease burden. The current autoimmune therapies focus on targeting inflammation or inducing immunosuppression rather than addressing the underlying cause of the diseases. The activity of metabolic pathways is elevated in autoimmune diseases, and metabolic changes are increasingly recognized as important pathogenic processes underlying these. Therefore, metabolically targeted therapies may represent an important strategy for treating autoimmune diseases. This review provides a comprehensive overview of the evidence surrounding glucose metabolic reprogramming and its potential applications in drug discovery and development for autoimmune diseases, such as type 1 diabetes, multiple sclerosis, systemic lupus erythematosus, rheumatoid arthritis, and systemic sclerosis.

N-benzyl-N-methyldecan-1-amine and its derivative mitigate 2,4- dinitrobenzenesulfonic acid-induced colitis and collagen-induced rheumatoid arthritis.

As our previous study revealed that N-benzyl-N-methyldecan-1-amine (BMDA), a new molecule originated from Allium sativum, exhibits anti-neoplastic activities, we herein explored other functions of the compound and its derivative [decyl-(4-methoxy-benzyl)-methyl-amine; DMMA] including anti-inflammatory and anti-oxidative activities. Pretreatment of THP-1 cells with BMDA or DMMA inhibited tumor necrosis factor (TNF)-α and interleukin (IL)-1ß production, and blocked c-jun terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), MAPKAP kinase (MK)2 and NF-κΒ inflammatory signaling during LPS stimulation. Rectal treatment with BMDA or DMMA reduced the severity of colitis in 2,4-dinitrobenzenesulfonic acid (DNBS)-treated rat. Consistently, administration of the compounds decreased myeloperoxidase (MPO) activity (representing neutrophil infiltration in colonic mucosa), production of inflammatory mediators such as cytokine-induced neutrophil chemoattractant (CINC)-3 and TNF-α, and activation of JNK and p38 MAPK in the colon tissues. In addition, oral administration of these compounds ameliorated collagen-induced rheumatoid arthritis (RA) in mice. The treatment diminished the levels of inflammatory cytokine transcripts, and protected connective tissues through the expression of anti-oxidation proteins such as nuclear factor erythroid-related factor (Nrf)2 and heme oxygenase (HO)1. Additionally, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels did not differ between the BMDA- or DMMA-treated and control animals, indicating that the compounds do not possess liver toxicity. Taken together, these findings propose that BMDA and DMMA could be used as new drugs for curing inflammatory bowel disease (IBD) and RA.

FAT10 Induces cancer cell migration by stabilizing phosphorylated ABI3/NESH.

The WAVE regulatory complex (WRC) is involved in various cellular processes by regulating actin polymerization. The dysregulation of WRC components is associated with cancer development. ABI family member 3 (ABI3)/new molecule including SH3 (NESH) is one of the WRC components and it has been reported that ABI3 phosphorylation can affect WRC function. Although several residues of ABI3 have been reported to be possible phosphorylation sites, it is still unclear which residues are important for the function of ABI3. Furthermore, it is unclear how the phosphorylated form of ABI3 is regulated. Here, we demonstrate that ABI3 is stabilized by its interaction with human leukocyte antigen-F adjacent transcript 10 (FAT10). Using phospho-dead or phospho-mimetic mutants of ABI3, we showed that serine 213 and 216 are important phosphorylation sites of ABI3. In particular, FAT10 has a higher affinity for the phosphorylated form of ABI3 than the non-phosphorylated form, and it stabilizes the phosphorylated form more than the non-phosphorylated form through this differential affinity. The interaction between FAT10 and the phosphorylated form of ABI3 promoted cancer cell migration. Therefore, our results suggest that FAT10 stabilizes the phosphorylated form of ABI3, which may lead to WRC activation, thereby promoting cancer cell migration.

Extracellular histones aggravate autoimmune arthritis by lytic cell death.

Although recent studies have demonstrated a proinflammatory effect of extracellular histones in sepsis via endothelial cytotoxicity, little is known about their contribution to autoimmune arthritis. Therefore, we investigated the role of extracellular histones in autoimmune arthritis and their cytotoxic effect on synoviocytes and macrophages. We measured histones in the synovial fluid of patients with rheumatoid arthritis (RA) and evaluated arthritis severity in a serum-transfer arthritis (STA) mouse model with intraperitoneal histone injection. Histone-induced cytotoxicity was measured using SYTOX green staining in the synoviocyte cell line MH7A and macrophages differentiated from the monocytic cell line THP-1, and the production of damage-associated molecular patterns (DAMPs) was measured by HMGB1 and ATP. Furthermore, we performed RNA-seq analysis of THP-1 cells stimulated with H2B-α1 peptide or with its citrullinated form. The levels of histones were elevated in RA synovial fluid, and histones aggravated arthritis in the STA model. Histones induced cytotoxicity and DAMP production in synoviocytes and macrophages. Chondroitin sulfate reduced histone-induced cytotoxicity, while lipopolysaccharides aggravated cytotoxicity. Moreover, the cytotoxicity decreased when the arginines in H2B-α1 were replaced with citrullines, which demonstrated its electrostatic nature. In transcriptome analysis, H2B-α1 changed the gene expression pattern of THP-1 cells involving chemokines, interleukin-1, -4, -10, -13, and toll-like receptor (TLR) signaling pathways. Extracellular histones were increased in RA synovial fluid and aggravated synovitis in STA. They induced lytic cell death through electrostatic interaction with synoviocytes and macrophages, leading to the secretion of DAMPs. These findings suggest that histones play a central role in autoimmune arthritis.

Myeloid IPMK promotes the resolution of serum transfer-induced arthritis in mice.

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by widespread joint inflammation, which leads to joint damage, disability, and mortality. Among the several types of immune cells, myeloid cells such as macrophages are critical for controlling the pathogenesis of RA. Inositol phosphates are water-soluble signaling molecules, which are synthesized by a series of enzymes including inositol phosphate kinases. Previous studies revealed actions of inositol phosphates and their metabolic enzymes in the modulation of inflammation such as Toll-like receptor-triggered innate immunity. However, the physiological roles of inositol polyphosphate (IP) metabolism in the regulation of RA remain largely uncharacterized. Therefore, our study sought to determine the role of inositol polyphosphate multikinase (IPMK), a key enzyme for IP metabolism and various cellular signaling control mechanisms, in mediating RA. Using myeloid cell-specific IPMK knockout (KO) mice, arthritis was induced via intraperitoneal K/BxN serum injection, after which disease severity was evaluated. Both wild-type and IPMK KO mice developed similar RA phenotypes; however, conditional deletion of IPMK in myeloid cells led to elevated arthritis scores during the resolution phase, suggesting that IPMK deficiency in myeloid cells impairs the resolution of inflammation. Bone marrow-derived IPMK KO macrophages exhibited no apparent defects in immunoglobulin Fc receptor (FcR) activation, osteoclast differentiation, or resolvin signaling. Taken together, our findings suggest that myeloid IPMK is a key determinant of RA resolution.

Mirodenafil ameliorates skin fibrosis in bleomycin-induced mouse model of systemic sclerosis.

Systemic sclerosis (SSc) is a chronic autoimmune disease characterized by fibrosis of the skin and internal organs. Despite the recent advances in the pathogenesis and treatment of SSc, effective therapies for fibrosis caused by SSc have not yet been established. In this study, we investigated the potential role of mirodenafil, a potent phosphodiesterase 5 (PDE5) inhibitor, in the treatment of fibrosis in SSc. We used a bleomycin (BLM)-induced SSc mouse model to mimic the typical features of fibrosis in human SSc and examined the dermal thickness to assess the degree of skin fibrosis after staining with hematoxylin and eosin or Masson's trichrome stains. The effect of mirodenafil on the expression of profibrotic genes was also analyzed by treating fibroblasts with transforming growth factor (TGF)-ß and mirodenafil. We showed that mirodenafil ameliorated dermal fibrosis and downregulated the protein levels of fibrosis markers including COL1A1 and α-SMA in the BLM-induced SSc mouse model. Further, using mouse embryonic fibroblasts and human lung fibroblasts, we demonstrated that the expression of collagen and profibrotic genes was reduced by treatment with mirodenafil. Finally, we showed that mirodenafil inhibited TGF-ß-induced phosphorylation of Smad2/3 in fibroblasts, which suggested that this drug may ameliorate fibrosis by suppressing the TGF-ß/Smad signaling pathway. Our findings suggest that mirodenafil possesses a therapeutic potential for treating fibrosis in SSc.

Protein phosphatase magnesium-dependent 1A induces inflammation in rheumatoid arthritis.

Rheumatoid arthritis (RA) is a highly inflammatory autoimmune disease. Although proinflammatory cytokines, including tumor necrosis factor (TNF) and interleukin (IL)-6, play a key role in the pathogenesis of RA, the causes of chronic inflammation are not fully understood. Here, we report that protein phosphatase magnesium-dependent 1A (PPM1A) levels were increased in RA synovial fluid compared with osteoarthritis (OA) synovial fluid and positively correlated with TNF levels. In addition, PPM1A expression was increased in synovial tissue from RA patients and joint tissue from a mouse model of arthritis. Finally, extracellular PPM1A induced inflammation by stimulating macrophages to produce TNF through toll-like receptor 4 (TLR4) and myeloid differentiation primary response protein 88 (MyD88) signaling pathway. Our findings suggest that extracellular PPM1A may contribute to the pathogenesis of RA by functioning as a damage-associated molecular pattern (DAMP) to induce inflammation.

DYSF expression in clear cell renal cell carcinoma: A retrospective study of 2 independent cohorts.

OBJECTIVE: Renal cell carcinoma (RCC) is the most typical type of kidney cancer in adults. Hypercalcemia is a well known paraneoplastic syndrome associated with RCC and recent studies have reported that hypercalcemia is closely related to the poor prognosis of RCC patients. Clear cell RCC (ccRCC) is the most common and aggressive subtype of RCC. Although the histological classification of RCC is important for determination of appropriate treatment strategies, effective biomarkers for predicting prognosis of ccRCC have not yet been identified. Since calcium levels affect the prognosis of RCC patients, we evaluated whether the calcium-sensing genes on the plasma membrane, including those encoding calcium channels, CaSR, GPRC6a, and DYSF, could be used as biomarkers to predict the prognosis of ccRCC patients. METHODS: Information from 537 patients from The Cancer Genome Atlas (TCGA; n = 446) and International Cancer Genome Consortium (ICGC; n = 91) was used in this study. Among these genes, DYSF was the only gene whose expression correlated with overall survival of both TGCA and ICGC patients. RESULTS: Although DYSF gene expression was higher in ccRCC tissue than in normal kidney tissue, Kaplan-Meier curves showed that the survival rate of ccRCC patients with high DYSF expression was significantly higher than that of patients with low DYSF expression (TCGA, P < 0.0001; ICGC, P = 0.0011). We also validated the potential of DYSF as a prognostic biomarker for ccRCC by conducting a time-dependent area under the curve (AUC) analysis and 5-years receiver operating characteristic curve analysis. Finally, multivariate regression analysis revealed that the expression of DYSF is independent of other prognostic parameters (TCGA, P = 0.017; ICGC, P = 0.006). CONCLUSIONS: These results suggested that DYSF may play a suppressive role in the progression of ccRCC and could act as a promising prognostic biomarker for predicting the survival of ccRCC patients.

VNN3 is a potential novel biomarker for predicting prognosis in clear cell renal cell carcinoma.

Although pathological observations provide approximate prognoses, it is difficult to achieve prognosis in patients with existing prognostic factors. Therefore, it is very important to find appropriate biomarkers to achieve accurate cancer prognosis. Renal cell carcinoma (RCC) has several subtypes, the discrimination of which is crucial for proper treatment. Here, we present a novel biomarker, VNN3, which is used to prognose clear cell renal cell carcinoma (ccRCC), the most common and aggressive subtype of kidney cancer. Patient information analyzed in our study was extracted from The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) cohorts. VNN3 expression was considerably higher in stages III and IV than in stages I and II. Moreover, Kaplan-Meier curves associated high VNN3 expression with poor prognoses (TCGA, p < .0001; ICGC, p = .00076), confirming that ccRCC prognosis can be predicted via VNN3 expression patterns. Consistent with all patient results, the prognosis of patients with higher VNN3 expression was worse in both low stage (I and II) and high stage (III and IV) (TCGA, p < 0.0001 in stage I and II; ICGC, p = 0.028 in stage I and II; TCGA, p = 0.005 in stage III and IV). Area under the curve and receiver operating characteristic curves supported our results that highlighted VNN3 expression as a suitable ccRCC biomarker. Multivariate analysis also verified the prognostic performance of VNN3 expression (TCGA, p < .001; ICGC, p = .017). Altogether, we suggest that VNN3 is applicable as a new biomarker to establish prognosis in patients with ccRCC.