Fibrosis related inflammatory mediators: Role of the IL-10 cytokine family

Importance of chronic fibroproliferative diseases (FDs) including pulmonary fibrosis, chronic kidney diseases, inflammatory bowel disease, and cardiovascular or liver fibrosis is rapidly increasing and they have become a major public health problem. According to some estimates about 45% of all deaths are attributed to FDs in the developed world. Independently of their etiology the common hallmark of FDs is chronic inflammation. Infiltrating immune cells, endothelial, epithelial, and other resident cells of the injured organ release an orchestra of inflammatory mediators, which stimulate the proliferation and excessive extracellular matrix (ECM) production of myofibroblasts, the effector cells of organ fibrosis. Abnormal amount of ECM disturbs the original organ architecture leading to the decline of function. Although our knowledge is rapidly expanding, we still have neither a diagnostic tool to detect nor a drug to specifically target fibrosis. Therefore, there is an urgent need for the more comprehensive understanding of the pathomechanism of fibrosis and development of novel diagnostic and therapeutic strategies. In the present review we provide an overview of the common key mediators of organ fibrosis highlighting the role of interleukin-10 (IL-10) cytokine family members (IL-10, IL-19, IL-20, IL-22, IL-24, and IL-26), which recently came into focus as tissue remodeling-related inflammatory cytokines

Role of IL-24 in the mucosal remodeling of children with coeliac disease

Background Recently, involvement of IL-19, IL-20 and IL-24 has been reported in inflammatory diseases associated with tissue remodeling. However, their impact on the pathomechanism of coeliac disease (CD) is still completely unknown. Methods Expression of IL19, IL20 and IL24 was measured by real-time RT-PCR, protein amount of IL-24, α smooth muscle actin (α-SMA) and fibronectin (FN) was determined by Western-blot analysis in the duodenal biopsies of therapy naive children with CD and controls. Localization of IL-24 and IL-20RB was investigated by immunofluorescent staining in the duodenal mucosa. Effect of recombinant IL-1β, TNF-α, TGF-β and IL-17 treatment on the expression of IL19, IL20, IL24 and their receptors was investigated by real-time RT-PCR in small intestinal epithelial cells (FHs74Int), in primary duodenal myofibroblasts (pdMFs) and in peripheral blood mononuclear cells (PBMCs). Effect of IL-24 on H2O2 treated FHs74Int cells and on pdMFs was measured by MTT, LDH, Annexin V assays, real-time RT-PCR and by fluorescent microscopy. Results We found increased level of IL-24 (3.3×, p < 0.05), α-SMA (2.4×, p < 0.05) and FN (2.3×, p < 0.05) in the duodenal mucosa and increased expression of IL19 (3.6×, p < 0.05) and IL24 (5.2×, p < 0.05) in the PBMCs of children with CD compared to that of controls. IL-1β was a strong inducer of IL24 expression of FHs74Int cells (9.9×, p < 0.05), pdMFs (552.9×, p < 0.05) or PBMCs (17.2×, p < 0.05), as well. IL-24 treatment reduced the number of apoptotic cells (0.5×, p < 0.05) and decreased the expression of inflammatory factors, including IL1A, IL6 and TNF of H2O2-treated FHs74Int cells. IL-24 decreased the proliferation (0.6×, p < 0.05) of PDGF-B treated pdMFs. Moreover, IL-24 treatment altered the morphology of pdMFs by influencing the size of the angles between stress fibers and the longitudinal axis of the cells (2.0×, p < 0.05) and the expression of cytoskeletal components, including ACTA2, ACTB, VIM, SNAI1 and SNAI2. Conclusion Our results suggest that IL-24 plays a significant role in the maintenance of duodenal mucosal integrity in CD

Microarray Analysis Reveals Increased Expression of Matrix Metalloproteases and Cytokines of Interleukin-20 Subfamily in the Kidneys of Neonate Rats Underwent Unilateral Ureteral Obstruction: A Potential Role of IL-24 in the Regulation of Inflammation and Tissue Remodeling

Background/Aims: Congenital obstructive nephropathy (CON) is the main cause of pediatric chronic kidney diseases leading to renal fibrosis. High morbidity and limited treatment opportunities of CON urge the better understanding of the underlying molecular mechanisms. Methods: To identify the differentially expressed genes, microarray analysis was performed on the kidney samples of neonatal rats underwent unilateral ureteral obstruction (UUO). Microarray results were then validated by real-time RT-PCR and bioinformatics analysis was carried out to identify the relevant genes, functional groups and pathways involved in the pathomechanism of CON. Renal expression of matrix metalloproteinase (MMP)-12 and interleukin (IL)-24 were evaluated by real-time RT-PCR, flow cytometry and immunohistochemical analysis. Effect of the main profibrotic factors on the expression of MMP-12 and IL-24 was investigated on HK-2 and HEK-293 cell lines. Finally, the effect of IL-24 treatment on the expression of pro-inflammatory cytokines and MMPs were tested in vitro. Results: Microarray analysis revealed 880 transcripts showing &#x3e;2.0-fold change following UUO, enriched mainly in immune response related processes. The most up-regulated genes were MMPs and members of IL-20 cytokine subfamily, including MMP-3, MMP-7, MMP-12, IL-19 and IL-24. We found that while TGF-β treatment inhibits the expression of MMP-12 and IL-24, H2O2 or PDGF-B treatment induce the epithelial expression of MMP-12. We demonstrated that IL-24 treatment decreases the expression of IL-6 and MMP-3 in the renal epithelial cells. Conclusions: This study provides an extensive view of UUO induced changes in the gene expression profile of the developing kidney and describes novel molecules, which may play significant role in the pathomechanism of CON

THE ROLE OF IL-20 CYTOKINE SUBFAMILY IN THE PATHOGENESIS OF CHRONIC KIDNEY DISEASE

Background: Regardless of the etiology kidney fibrosis is a common outcome of progressive chronic kidney diseases. Our recent study showed that levels of interleukin (IL)-20 subfamily members, including IL-19 and IL-24 significantly increased in kidneys underwent unilateral ureteral obstruction (UUO). However, their precise role in the pathomechanism of renal fibrosis is not clearly understood. Methods: To study the role of IL-20 cytokine subfamily we applied a mouse model of UUO induced kidney fibrosis on wild type and IL-20 receptor beta gene knockout (IL-20Rβ KO) mice. Masson’s trichrome and Picro-Sirius Red staining were used to investigate the renal accumulation of extracellular matrix proteins. Real-time RT-PCR and western blot method were performed to measure the renal expression of fibrosis associated molecules. We also investigated the in vitro effect of IL-24 treatment on transforming growth factor beta (TGF-β) and platelet derived growth factor B (PDGF-B) expression of human proximal tubular epithelial (HK-2) cells by real-time RT-PCR and flow cytometry. Results: We found elevated level of IL-19, IL-24 and IL-20Rβ in the fibrotic kidneys. IL-20Rβ KO mice showed reduced extracellular matrix deposition and decreased α-smooth muscle actin expression compared to wild-type mice following UUO. Treatment of renal epithelial cells with IL-24 increased their TGF-β and PDGF-B production. Conclusion: Our study provides direct evidence of the pathogenic role of IL-20 cytokine subfamily in the development of renal fibrosis, possibly through the IL-24 mediated production of pro-fibrotic factors. Therefore, inhibition of IL-24 may have therapeutic effect in treatment of chronic kidney diseases. Grants: OTKA K116928 and VKE-2017-00006. This project was supported by the János Bolyai Research Scholarship of the Hungarian Academy of Science

Involvement of Parkinson’s disease 7 in inflammatory bowel diseases: relation to interleukin-17 and tumor necrosis factor-alpha

Introduction: The therapy of inflammatory bowel diseases (IBD) is still unresolved, however, recent studies suggested the importance of interleukin (IL)-17. Parkinson's disease 7 (PARK7) is an antioxidant, immunoregulatory molecule, but its relation to IL-17 and the core TNF-α related pathway of IBD is completely unknown. Thus we aimed to investigate its involvement in the pathogenesis of IBD. Materials and methods: The mRNA expression, protein level and localization of PARK7 were determined in colon biopsies of children with IBD, in colon of wild type and Il17 KO mice with dextran sodium sulphate (DSS)-induced colitis and in IL-17-treated HT-29 colonic epithelial cells by real-time PCR, western blot, flow cytometry, and immunofluorescence staining, respectively. The effect of PARK7 on TNF-α was measured in PARK7 specific silencing RNA treated HT-29 cells. Results: Expression of PARK7 and IL-17 was elevated in the colonic mucosa of children with IBD and also in the colon of wild type mice with DSS-induced colitis compared to controls. Lack of IL-17 in Il17 KO mice prevented the DSS-induced elevation of colonic PARK7 level in vivo. Similarly, IL-17 treatment induced the production of PARK7 and TNF-α of HT-29 colon epithelial cells in vitro. TNF-α production were even more pronounced in the PARK7 siRNA treated HT-29 cells. Conclusion: Increased expression of PARK7 in IBD suggest its involvement in the disease pathogenesis. Moreover, we demonstrated that PARK-7 is an endogenous regulator of the IL-17 induced production of TNF-α. Taken together our data suggest that PARK7 may be a therapeutic target in the future. Grant support: Supported by ÚNKP-17-3 New National Excellence Program of the Ministry of Human Capacities, MTA-SE Pediatrics and Nephrology Research Group, János Bolyai Research Scholarship of the Hungarian Academy of Sciences, OTKA K116928 and VKE-2017- 00006 grants

PARK7 diminishes oxidative stress-induced mucosal damage in celiac disease

Coeliac disease (CD) is a chronic, immune-mediated small intestinal enteropathy, accompanied with gluten-triggered oxidative damage of duodenal mucosa. Previously, our research group reported an increased mucosal level of the antioxidant protein Parkinson’s disease 7 (PARK7) in children with CD. In the present study, we investigated the role of increased PARK7 level on the epithelial cell and mucosal integrity of the small intestine. The presence of PARK7 was investigated using immunofluorescent staining on duodenal mucosa of children with CD and on FHs74Int duodenal epithelial cells. To investigate the role of oxidative stress, FHs74Int cells were treated with H2O2 in the absence or presence of Comp23, a PARK7-binding compound. Intracellular accumulation of reactive oxygen species (ROS) was determined by DCFDA-based assay. Cell viability was measured by MTT, LDH, and Annexin V apoptosis assays. Disruption of cytoskeleton and cell adhesion was investigated by immunofluorescence staining and by real-time RT PCR. Effect of PARK7 on mucosal permeability was investigated ex vivo using intestinal sacs derived from control and Comp-23-pretreated mice. Comp23 treatment reduced the H2O2-induced intracellular accumulation of ROS, thus preserving the integrity of the cytoskeleton and also the viability of the FHs74Int cells. Accordingly, Comp23 treatment increased the expression of antioxidants (NRF2, TRX1, GCLC, HMOX1, NQO1), cell-cycle regulators (TP53, CDKN1A, PCNA, BCL2, BAX), and cell adhesion molecules (ZO1, CDH1, VCL, ITGB5) of H2O2-treated cells. Pretreatment with Comp23 considerably decreased the small intestinal permeability. In this study, we demonstrate that PARK7-binding Comp23 reduces the oxidative damage of duodenal epithelial cells, via increased expression of NRF2- and P53-regulated genes. Our results suggest that PARK7 plays a significant role in the maintenance of mucosal integrity in CD

The role of interleukin-24 in the pathomechanism of IBD-associated tissue remodeling

Abstract: Introduction: Intestinal fibrosis is a serious complication of inflammatory bowel diseases (IBD). Interleukin(IL)-24 is a member of IL-20 cytokine subfamily, which regulatory effect is suspected in connection with inflammation, apoptosis or tissue remodeling in other organs. Increased level of IL-24 was described in the colon of patients with active IBD, however its biological role is still poorly understood. Methods: Colonic presence of IL-24 and its receptor IL-20RB was investigated in the dextran-sodium sulfate (DSS) induced mice model of IBD (n=8; C57BL/6J). Impact of IL-24 on colonic extracellular matrix (ECM) production was investigated in the DSS treated wild type and IL-20RB knockout (KO) mice. Effect of intracolonic injection of IL-24 was also investigated. The role of IL-24 treatment on the expression of fibrosis related genes was investigated in colonic epithelial (HT-29) and fibroblast (CCD-18Co) cells. Results: Expression of IL-24 increased in colonic tissue of DSS-treated mice compared to controls. Lack of IL-24 receptor resulted in reduced ECM deposition in IL-20RB KO mice compared to wild type group. Local administration of IL-24 increased the expression of the fibrosis associated genes in the colon. IL-24 treatment increased the expression of TGF-ß1 and PDGF-B in HT-29, and that of COL1, COL3, FN1, MMP2, -9, TIMP1, -2 in CCD-18Co cells. Discussion: IL-24 may promote tissue remodeling shifted toward an excessive deposition of ECM components directly by acting on fibroblast and indirectly via induction of pro-fibrotic factors on epithelial cells. Our data suggest that inhibition of IL-24 may have a significant anti-fibrotic effect. Support: OTKA-K116928, VKE-2017-00006,EFOP-3.6.3-VEKOP-16-2017-00009,MTA-SE Pediatrics and Nephrology Research Group, János Bolyai Research Scholarship of the Hungarian Academy of Science

SELECTIVE MEASUREMENT OF α SMOOTH MUSCLE ACTIN: WHY β-ACTIN CAN NOT BE USED AS A HOUSEKEEPING GENE WHEN TISSUE FIBROSIS OCCURS

Abstract Background Prevalence of fibroproliferative diseases, including chronic kidney disease is rapidly increasing and has become a major public health problem worldwide. Fibroproliferative diseases are characterized by increased expression of α smooth muscle actin (α-SMA) that belongs to the family of the six conserved actin isoforms showing high degree homology. The aim of the present study was to develop real-time PCRs that clearly discriminate α-SMA and ß-actin from other actin isoforms. Results Real-time PCRs using self-designed mouse, human and rat specific α-SMA or ß-actin primer pairs resulted in the specific amplification of the artificial DNA templates corresponding to mouse, human or rat α-SMA or ß-actin, however ß-actin showed cross-reaction with the housekeeping γ-cyto-actin. We have shown that the use of improperly designed literary primer pairs significantly affects the results of PCRs measuring mRNA expression of α-SMA or ß-actin in the kidney of mice underwent UUO. Conclusion We developed a set of carefully designed primer pairs and PCR conditions to selectively determine the expression of mouse, human or rat α-SMA and ß-actin isoforms. We demonstrated the importance of primer specificity in experiments where the results are normalized to the expression of ß-actin especially when fibrosis and thus increased expression of α-SMA is occur