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MicroRNAs (miRNAs) control gene expression at the posttranscriptional level and have a critical role in many biological processes such as oligodendrocyte differentiation. Recent studies have shown that microRNA 338 (miR-338) is overexpressed during the oligodendrocyte development process in the central nervous system; this finding indicates a potentially important role for miR-338 in oligodendrocyte development. To evaluate this assumption, we studied the effect of miR-338 overexpression on promoting the differentiation of oligodendrocyte progenitor cells (OPCs), derived from human-induced pluripotent stem cells (hiPSC), into preoligodendrocyte. hiPSCs were differentiated into OPCs after treating for 16 days with basic fibroblast growth factor (BFGF), epidermal growth factor (FGF), and platelet-derived growth factor (PDGF)-AA. Bipolar OPCs appeared and the expression of OPC-related markers, including Nestin, Olig2, Sox10, PDGFRα, and A2B5 was confirmed by real-time polymerase chain reaction (PCR) and immunofluorescence. Then, OPCs were transduced by miR-338 expressing lentivirus or were treated with triiodothyronine (T3) for 6 days. Data obtained from real-time PCR and immunofluorescence experiment indicated that preoligodendrocyte markers such as Sox10, O4, and MBP were expressed at higher levels in transduced cells with miR-338 in comparison with the T3 group. So, the overexpression of miR-338 in iPSC-derived OPCs can promote their differentiation into preoligodendrocyte which can be used in cell therapy of myelin-related diseases.

Perivascular accumulation of lymphocytes can be a prominent histopathologic feature of various human inflammatory skin diseases. Select examples include systemic sclerosis, spongiotic dermatitis, and cutaneous lupus. Although a large body of work has described various aspects of the endothelial and vascular smooth muscle layers in these diseases, the outer adventitial compartment is poorly explored. The goal of the current study was to characterize perivascular adventitial fibroblast states in inflammatory human skin diseases and relate these states to perivascular lymphocyte accumulation. In normal skin, adventitial fibroblasts are distinguished by CD90 expression, and dense perivascular lymphocytic infiltrates are uncommon. In systemic sclerosis, this compartment expands, but lymphocyte infiltrates remain sparse. In contrast, perivascular adventitial fibroblast expression of VCAM1 is upregulated in spongiotic dermatitis and lupus and is associated with a dense perivascular T cell infiltrate. VCAM1 expression marks transitioned fibroblasts that show some resemblance to the reticular stromal cells in secondary lymphoid organs. Expanded adventitial compartments with perivascular infiltrates similar to the human settings were not seen in the inflamed murine dermis. This species difference may hinder the dissection of aspects of perivascular adventitial pathology. The altered perivascular adventitial compartment and its associated reticular network form a niche for lymphocytes and appear to be fundamental in the development of an inflammatory pattern.

The importance of tissue engineering has been established as a promising approach in treating neurodegenerative diseases. The purpose of the current study is to determine the effect of fibrin hydrogel on the differentiation of iPSC into oligodendrocyte. For this purpose, iPSCs transduced by miR-338 expressing lentiviruses. They were treated with basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), and platelet-derived growth factor (PDGF)-AA. The process was traced by a 6-day treatment in a mitogen-free medium. At the end of the process, multipolar preoligodendrocytes appeared. In comparison to tissue culture plate (TCP), MTT assay demonstrated a significant increase in the viability of cells cultured in fibrin hydrogel. SEM analysis showed cells with elongated morphology and intertwined intercellular interactions. An immunofluorescent assay confirmed the expression of oligodendrocyte markers Olig2 and O4. In comparison to TCP, real-time PCR data indicated a significant increase in the expression of some markers such as Olig2, MBP, Sox10, and PDGFRα on cells encapsulated in fibrin hydrogel. Overall, the results suggest that fibrin hydrogel improves viability of cells and promotes the differentiation of iPSCs into preoligodendrocytes. Hence, it can be used as an appropriate option in the tissue engineering in order to treat neurodegenerative diseases. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 108B:192-200, 2020.

The purpose of this study was to evaluate T-cell immunity markers using serial post-transplantation monitoring of cytokine-producing cells during the first post-transplant months for the prediction of acute rejection and potentially chronic rejection of kidney allograft. We followed 57 kidney allograft recipients for meanly 3 years post-transplantation. Blood samples were collected pre-transplant, 2, 4 and 12 weeks post-transplant. The frequencies of IL-10-, IL-17- and IFN-γ-producing cells were determined in all time-points using ELISPOT assay. The results of ELISpot monitoring and levels of IL-23 and TGF-β were compared between recipients with acute (n = 12) or chronic rejection episodes and patients with stable graft function (n = 45). In all post-transplant time-points, significantly high frequencies of IFN-γ- and IL-17-producing cells and low frequency of IL-10-producing cells were observed in rejection group versus patients with stable graft function (P 0.0001). The ROC curve analysis for determining the reliability of cytokine-producing cells for the prediction of acute rejection revealed that AUC was 0.046 for IL-10 (P 0.001), 0.927 for IL-17 (P 0.001) and 0.929 for INF-γ-producing cells (P 0.001). Our results indicate that analyzing the frequencies of INF-γ/IL-10/IL-17-producing cells may define a reliable panel for the prediction of acute rejection within the first post-transplant year which could also be applicable for the prediction of chronic rejection episodes.

Tissue injury triggers the activation and differentiation of multiple cell types to minimize damage and initiate repair processes. In systemic sclerosis, these repair processes appear to run unchecked, leading to aberrant remodeling and fibrosis of the skin and multiple internal organs, yet the fundamental pathological defect remains unknown. We describe herein a transition wherein the abundant CD34 + dermal fibroblasts present in healthy human skin disappear in the skin of systemic sclerosis patients, and CD34 − , podoplanin + , and CD90 + fibroblasts appear. This transition is limited to the upper dermis in several inflammatory skin diseases, yet in systemic sclerosis, it can occur in all regions of the dermis. In vitro , primary dermal fibroblasts readily express podoplanin in response to the inflammatory stimuli tumor necrosis factor and IL-1β. Furthermore, we show that on acute skin injury in both human and murine settings, this transition occurs quickly, consistent with a response to inflammatory signaling. Transitioned fibroblasts partially resemble the cells that form the reticular networks in organized lymphoid tissues, potentially linking two areas of fibroblast research. These results allow for the visualization and quantification of a basic stage of fibroblast differentiation in inflammatory and fibrotic diseases in the skin.

Systemic Sclerosis (SSc) is a systemic autoimmune disorder, with ambiguous pathogenesis. Genetic and environmental factors were proved to be correlated with SSc aetiology. Single nucleotide polymorphisms (SNPs) in cytokine genes can alter the structure and function of the cytokines and consequently may increase the susceptibility to a specific disease. In this study, we investigated SNPs of the IL-1 gene cluster in Iranian SSc patients. We obtained blood samples from 170 SSc patients and 213 healthy individuals. Cytokine genotyping results were obtained by polymerase chain reaction with sequence-specific primers (PCR-SSP). IL-1A rs1800587, IL-1B rs1143634 and IL-1R1 rs2234650 were evaluated for SNP study. The frequency of the IL-1B rs1143634 CT genotype was significantly lower in SSc patients compared to the controls (OR = 0.584; 95% CI = 0.385-0.886; P-value = 0.023), so we propose that CT genotype of this allele might be protective. According to our haplotype analysis, CCC haplotype frequency is higher in the control group compared to SSc patients (OR = 1.575; 95% CI = 1.176-2.111; P-value = 0.008) and in contrast, CTC haplotype frequency is lower in the control group compared to SSc patients (OR = 0.152; 95% CI = 0.047-0.484; P-value = 0.002), so they might decrease and increase the susceptibility of having SSc, respectively. In addition, we reported two significant diplotypes frequency differences among SSc patients and healthy individuals. It is highly important that there is not much resemblance between the IL-1 gene cluster polymorphism in different populations, so we can indicate that SNPs may play critical roles when they are combined with other genetic and environmental factors.

Recruitment of T cells polarized to preferentially produce interleukin-4 (IL-4), IL-5, and IL-13, belonging to the Th2-like T subset, has been implicated in fibrosis and remodeling in systemic sclerosis (SSc) (1–3). Our recent work, analyzing peripheral blood mononuclear cells (PBMCs), identified high expression of several genes critical to IL-13 signaling by PBMCs from both patients with limited cutaneous SSc (lcSSc) and those with diffuse cutaneous SSc (dcSSc), especially in those with pulmonary arterial hypertension (PAH). Mannose receptor 1 (MRC1), an IL-13–regulated gene that is highly up-regulated on alternatively activated macrophages, was highly expressed by PBMCs from patients with SSc-associated PAH, and its expression correlated with pulmonary pressure and mortality (4). In addition, IL-13 has recently been strongly implicated in SSc skin disease (5). These data suggest that IL-13 is involved in the fibrotic pathway of SSc, but also plays a key role in the vasculopathic process, leading to PAH, a deadly complication of the disease. Despite these observations implicating IL-13 in SSc pathogenesis, little progress has been made in identifying upstream events that ultimately lead to the Th2 profibrotic signaling in SSc. Thymic stromal lymphopoietin (TSLP) has been shown to play a crucial role in skewing T cells to a Th2 phenotype (6). TSLP is an IL-7 cytokine family member, highly produced by epithelial cells at barrier surfaces and, consequently, the first molecule produced after many disturbances in homeostasis (7). It strongly regulates immune cells such as dendritic cells, T and B cells, and granulocytes (8), and transgenic TSLP expression in the skin and lungs of mice leads to a fibrotic phenotype similar to atopic dermatitis and asthma, respectively (9,10). In addition to being tightly linked to fibrosis and possibly one of the master regulators of a Th2 phenotype, TSLP is highly induced by bacteria, viruses, and Toll-like receptor (TLR) ligands (11), and thus might play a key role in activating the immune system and in stimulating fibrosis after exposure to environmental stimuli. We show here that TSLP is highly expressed in the skin of patients with dcSSc, mainly by immune cells in perivascular areas. In addition, we show that chronic subcutaneous stimulation of skin by TSLP activates Smad2 phosphorylation and leads to alterations in gene expression that overlap significantly with gene expression induced by transforming growth factor β (TGFβ) as well as IL-13. Examining the effects of these cytokines in IL-4Rα1– and TSLP-deficient mice revealed a striking overlap in induced gene expression and a complex interaction between these cytokines. Since poly(I-C) induced high levels of TSLP, these observations potentially link an environmental trigger, such as a TLR ligand, to SSc disease pathogenesis.

Ankylosing spondylitis (AS) is one of the most common causes of inflammatory arthritis, with an estimated prevalence of 0.1-0.9%. Genetic factors have been strongly implicated in its aetiology, and heritability as assessed by twin studies has been estimated to be >90%. HLA- B27 is almost essential for inheritance of AS; it is not merely sufficient for explaining the pattern of familial recurrence of the disease. This study's purpose is to investigate the association of ankylosing spondylitis with single-nucleotide polymorphisms (SNPs) in the IL-1 family: IL-1a (-889C/T) rs1800587, IL-1b (-511C/T) rs16944, IL-1b (+3962C/T) rs1143634, IL-1R (Pst-1 1970C/T) rs2234650 and IL-1RA (Mspa-1 11100C/T) rs315952. 99 unrelated Iranian AS patients and 217 healthy control subjects were selected. Cytokine typing was performed by the polymerase chain reaction with sequence-specific primers assay. The allele and genotype frequencies of the polymorphisms were determined: The IL1α rs1800587, IL1β rs16944 and IL1β rs1143634 were not significantly associated with AS. Genotype frequencies at IL1R rs2234650 differed between cases and controls (χ(2)=8.85; p=0.01); the IL1R rs2234650 C/T and T/T genotypes were less common in AS patients than controls. The IL1R rs2234650 C/T genotype was inversely associated with AS comparing with the IL1R rs2234650 C/C genotype (OR=0.48; p=0.005). IL1R rs2234650 C/T genotype was less common in patients than controls (OR=0.37; p=0.02).Furthermore IL1R rs2234650 T allele was strongly associated with HLA-B2702 patients rather than HLA-B2705 but was not associated with HLA-B27 negative patients (OR=0.33; p=0.01). Polymorphisms of IL1α rs1800587, IL1β rs16944 and IL1β rs1143634 were not significantly associated with ankylosing spondylitis but inversely in this study IL1R rs2234650 was significantly associated and carriage of T allele in IL1R rs2234650 seems to be protective, while carriage of C allele result in two fold higher risk of developing AS.

Introduction The crucial role of innate immunity in the pathogenesis of systemic sclerosis (SSc) is well established, and in the past few years the hypothesis that Toll-like receptor 4 (TLR4) activation induced by endogenous ligands is involved in fibrogenesis has been supported by several studies on skin, liver, and kidney fibrosis. These findings suggest that TLR4 activation can enhance transforming growth factor beta (TGF-β) signaling, providing a potential mechanism for TLR4/Myeloid differentiation factor 88 (MyD88)-dependent fibrosis. Methods The expression of TLR4, CD14 and MD2 genes was analyzed by real-time polymerase chain reaction from skin biopsies of 24 patients with diffuse cutaneous SSc. In order to investigate the effects of the chronic skin exposure to endotoxin (Lipopolysaccharide (LPS)) in vivo we examined the expression of inflammation, TGF-β signaling and cellular markers genes by nanostring. We also identified cellular subsets by immunohistochemistry and flow cytometry. Results We found that TLR4 and its co-receptors, MD2 and CD14, are over-expressed in lesional skin from patients with diffuse cutaneous SSc, and correlate significantly with progressive or regressive skin disease as assessed by the Delta Modified Rodnan Skin Score. In vivo, a model of chronic dermal LPS exposure showed overexpression of proinflammatory chemokines, recruitment and activation of macrophages, and upregulation of TGF-β signature genes. Conclusions We delineated the role of MyD88 as necessary for the induction not only for the early phase of inflammation, but also for pro-fibrotic gene expression via activation of macrophages. Chronic LPS exposure might be a model of early stage of SSc when inflammation and macrophage activation are important pathological features of the disease, supporting a role for innate immune activation in SSc skin fibrosis.