Fibrotic Complications Research Articles

Sera from Rheumatoid Arthritis Patients Induce Oxidative Stress and Pro-Angiogenic and Profibrotic Phenotypes in Human Endothelial Cells.

Background: Rheumatoid arthritis (RA) is a long-term autoimmune condition marked by persistent inflammation of the joints and various systemic complications, including endothelial dysfunction, atherosclerosis, and pulmonary fibrosis. Oxidative stress is a key contributor to the pathogenesis of RA, potentially exacerbating vascular damage and promoting pro-angiogenic and profibrotic processes. Objective: This study aims to investigate the effects of sera from RA patients on human umbilical vein endothelial cells (HUVECs), focusing on the induction of oxidative stress, endothelial cell proliferation, migration, and collagen type I synthesis. Methods: Twenty-eight serum samples were collected from RA patients and healthy donors (HDs). HUVECs were exposed to these sera, and intracellular reactive oxygen species (ROS) levels were fluorescently detected using H2DCF-DA. Cell viability was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell migration was evaluated through a scratch wound assay, and collagen type I synthesis was measured using a lentiviral vector expressing the green fluorescent protein (GFP) under the control of the human COL1A1 gene promoter. Results: Exposure to RA sera resulted in a significant increase in intracellular ROS levels in HUVECs compared to HD sera, indicating an elevated state of oxidative stress. RA sera also promoted endothelial cell proliferation and migration, suggesting a pro-angiogenic stimulus. Additionally, RA sera significantly increased collagen type I synthesis in HUVECs, implicating a potential role in profibrotic processes associated with RA. Conclusion: The results of this study emphasize the importance of circulating factors in RA sera in promoting oxidative stress, endothelial dysfunction, and pro-angiogenic and profibrotic phenotypes in endothelial cells. These processes may contribute to the vascular and fibrotic complications observed in RA, highlighting the necessity for additional research into focused therapeutic approaches to alleviate these effects.

Ternary inulin hydrogel with long-term intestinal retention for simultaneously reversing IBD and its fibrotic complication.

Excessive accumulation of reactive oxygen and nitrogen species (RONS) and dysbiosis of intestinal microbiota are pivotal symptoms for inflammatory bowel disease (IBD) and its associated complications, such as intestinal fibrosis. This research introduces a probiotic inulin hydrogel loaded with polypyrrole (PPy) nanozymes and antifibrotic drug pirfenidone (PFD) (PPy/PFD@Inulin gel) designed for the concurrent amelioration of IBD and its fibrotic complication. Upon oral administration, the inulin gel matrix could extend the gastrointestinal residence time of PPy nanozymes and PFD, facilitating the efficient reduction of pro-inflammatory cytokine levels and enhancement of the intestinal epithelial barrier repair as well as the suppression of intestinal fibrosis through sustained RONS scavenging, modulation of gut microbiota and attenuation of the TGF-β/Smad signaling pathway to inhibit fibroblast proliferation. Notably, the PPy/PFD@Inulin gel demonstrated significant prophylactic and therapeutic efficacy in acute and chronic colitis as well as intestinal fibrosis induced by dextran sodium sulfate (DSS) in mouse models. Thus, the engineered ternary PPy/PFD@Inulin gel offered a pioneered paradigm for simultaneous reversal of IBD and its associated complications, such as intestinal fibrosis, in a single therapeutic regimen.

Neutrophil extracellular traps activate Notch–γ-secretase signaling in hidradenitis suppurativa

BackgroundHidradenitis suppurativa (HS) is an inflammatory chronic skin disorder of unknown etiology characterized by inflamed abscess-like nodules and boils resulting in sinus tract formation, tissue scarring and massive infiltration of neutrophils. Multiple lines of evidence have highlighted the potential association between alterations in the Notch pathway and HS pathogenesis, but the mechanisms remain incompletely characterized. ObjectiveHerein, we aim to elucidate the role of neutrophil extracellular traps in Notch-γ-secretase, signaling. MethodsTwenty-six HS lesional tissues, primary HS macrophages and skin fibroblasts were interrogated by quantitative PCR, western blot, and Elisa analyses. γ-Secretase, and TACE activities were measured in HS skin lesions, macrophages and skin fibroblasts. Immunofluorescence and RNAscope analyzes were performed in HS and control skin. ResultsA prominent presence of Notch ligands, DLL4 and JAG2 were detected at the protein and mRNA levels in HS skin lesion when compared to control. Levels of DLL4, JAG1, cit-H3-DNA and γ-secretase activity correlated with HS disease severity. Additionally, significantly elevated levels of Notch ligands and γ-secretase activity were found in dissected sinus tracts when compared to the rest of HS tissue. Immunofluorescence microscopy in HS skin lesions showed activation of Notch 1 signaling in macrophages and skin fibroblasts. Neutrophil extracellular traps (NETs) purified from HS patients displayed elevated levels of DLL4. HS-NETs activated the Notch pathway in macrophages and dermal fibroblasts isolated from HS patients. HS skin fibroblasts displayed elevated levels of CD90 and DPP4 in association with increased migratory capacity and Notch activation. Inhibition of Notch decreased migratory capacity and pro-fibrotic markers in HS fibroblasts. ConclusionThese data support a pathogenic connection between NETs, Notch- γ-secretase activation and the release of pro-fibrotic molecules that promote dysregulation of macrophages and skin fibroblasts in HS. Unveiling the relevance of these molecular events not only expands our understanding of HS but also opens new venues for the development of targeted therapies to address the fibrotic complications of advanced stages of HS.

Efficacy of Phlogenzyme® in men following transurethral laser enucleation of prostate hyperplasia: results of a randomized trial

Introduction. The most advanced and effective method of surgical treatment for benign prostatic hyperplasia (BPH) is transurethral laser enucleation of the prostate (tLEP). Recently, there has been a growing interest in exploring new approaches to reduce the risk of complications following tLEP.Objective. To evaluate the efficacy of using Phlogenzym® as part of a comprehensive treatment plan for patients following tLEP to reduce dysuria (urinary discomfort), leukocyturia (white blood cells in urine), and prevent infectious and fibrosis-related complications.Materials & methods. An open-label, randomized trial enrolled 105 patients undergoing tLEP. The patients were randomly assigned to two groups: the study group (n=50) received standard postoperative care in combination with Phlogenzym® for 30 days, while the control group (n=55) received standard care (α1-adrenergic blocker for 28 days) only. uring the follow-up period, which lasted for 1, 3, and 6 months postoperatively, complaints were evaluated using the IPSS-QoL, and IIEF-5 questionnaires, as well as indicators of urinalysis and urine culture, prostate volume measurements, residual urine volume, and uroflowmetry data.Results. Among all patients, the median preoperative values for prostate volume, IPSS, QoL score, and median peak urine flow rate were 90 cc, 18 points, 5 points, and 7.9 mL/s, respectively, with no significant differences between the groups. One month after surgery, in the study group, there was a more significant decrease in prostate volume (57% vs. 41%), although this difference was not statistically significant (p > 0.05). At the 6-month follow-up, bacteriuria was less common in the study group (42% vs. 67%), and there was a consistent trend toward a reduction in the incidence of fibrous complications, although these differences were not statistically significant either (p > 0.05). No adverse events occurred during the follow-up period.Conclusion. Our experience suggests that the use of Phlogenzym® is safe during the postoperative period following tLEP surgery. The use of this drug leads to a reduction in prostate volume postoperatively and significantly reduces the bacteriuria by the six-month follow-up. Additionally, there is a persistent positive trend towards reducing the overall incidence of fibrotic complications in the surgical site. The results achieved and the absence of significant side effects characterize Phlogenzym® as having a favorable clinical profile.

A MODEL TO STUDY INTESTINAL FIBROSIS IN IPSC-DERIVED HUMAN EPITHELIAL AND MESENCHYMAL CELLS FROM CROHN’S DISEASE PATIENTS

Abstract INTRODUCTION Intestinal fibrosis is a serious complication of Crohn's disease (CD) and is caused by the excess deposition of extracellular matrix (ECM) proteins. Numerous cell types, including intestinal epithelial and mesenchymal cells, are implicated in this but research efforts are impaired by a lack of in vitro models. To overcome this, we have previously developed a human model of intestinal fibrosis using iPSC-derived epithelial and mesenchymal cells generated from both control and CD patients. Using this model, we aimed to further characterize the transcriptomic signature associated with the fibrotic response as well as other functional hallmarks of fibrosis. METHODS iPSCs from 19 CD patients with (10) and without (9) fibrotic complications were directed to form HIOs. As iPSC-derived HIOs contain epithelial and mesenchymal cells, the organoids were dissociated to generate purified cultures of epithelial only-HIOs (eHIOs) and intestinal mesenchymal cells (MSCs). eHIO and MSC cultures were treated with TNFα and TGFβ, alone or in combination. We evaluated the transcriptomic profile of both cell types via RNA-seq and carried out additional studies via ELISA, ECM staining and scratch assay. RESULTS RNAseq analysis on the effects of cytokine induction in eHIOs lead to an enrichment in pathways associated with inflammation and regulation of the immune response. Furthermore, eHIOs from patients with fibrotic complications showed a significant upregulation of ORM1 regardless of culture conditions, which was subsequently confirmed at the protein level indicating an intrinsic difference between both patient groups. RNAseq analysis on MSC cultures found differentially expressed genes clustered in pathways associated with ECM production and remodeling, and cell migration and proliferation. Cell migration capacity of MSCs was assessed by measuring the reduction in scratch area and under basal conditions, MSCs from the fibrotic cohort had a lower rate of cell migration (40.81%) compared to the non-fibrotic cohort (20.97%); notably, the addition of TNFα appeared to accelerate the migration capacity of MSCs in both fibrotic (14.54%) and non-fibrotic (6.56%) samples. Finally, compared to untreated cultures, MSCs treated with TNFα/TGFβ exhibited a significant increase in ECM deposition (2.64- and 2.29-fold increase for non-fibrotic and fibrotic, respectively). CONCLUSION We have demonstrated the functionality of our model of intestinal fibrosis generated from iPSC-derived epithelial and mesenchymal cells from CD patients. Furthermore, we have identified both generalized and intrinsic differences in our cohort of patients with fibrotic complications. Future experiments on the role of ORM1 in intestinal fibrosis and its effects on mesenchymal cells could provide a deeper understanding of the events leading the development of intestinal fibrosis in CD patients.

Increased Activity of MAPKAPK2 within Mesenchymal Cells as a Target for Inflammation-Associated Fibrosis in Crohn's Disease.

Mesenchymal stromal cells are suggested to play a critical role in Crohn's disease [CD]-associated fibrosis. MAPKAPK2 [MK2] has emerged as a potential therapeutic target to reduce inflammation in CD. However, the cell-specific pattern of phospho-MK2 activation and its role in CD-associated fibrosis are unknown. The objectives of this study were to evaluate cell-specific changes in MK2 activity between predominantly inflammatory CD vs CD with fibrotic complications and define the role of stromal cell-specific MK2 activation in CD-associated fibrosis. CD tissue, CD tissue-derived mesenchymal stromal cells known as myo-/fibroblasts [CD-MFs], and fibroblast-specific MK2 conditional knockout [KO] mice were used. In the inflamed area of predominantly inflammatory CD, high MK2 activity was equally distributed between mesenchymal and haematopoietic cells. By contrast, in CD with fibrotic complications, high MK2 activity was mostly associated with mesenchymal stromal cells. Using ex vivo CD tissue explants and an IL-10KO murine colitis model, we demonstrated that pro-fibrotic responses are significantly reduced by treatment with the MK2 inhibitor PF-3644022. Inhibition of MK2 activity in primary cultures of CD-MFs significantly reduced basal and TGF-β1-induced profibrotic responses. Using fibroblast-specific MK2 knockout mice in chronic dextran saline sulphate colitis, we demonstrated that fibroblast intrinsic MK2 signalling is among the key processes involved in the chronic inflammation-induced profibrotic responses. Our data suggest that activation of MK2 within fibroblasts contributes to the chronic inflammation-induced fibrosis in CD and that targeting MK2 has potential for the development of novel therapeutic approaches for fibrosis in CD.

Targeting Interleukin-17 as a Novel Treatment Option for Fibrotic Diseases.

Fibrosis is the end result of persistent inflammatory responses induced by a variety of stimuli, including chronic infections, autoimmune reactions, and tissue injury. Fibrotic diseases affect all vital organs and are characterized by a high rate of morbidity and mortality in the developed world. Until recently, there were no approved antifibrotic therapies. In recent years, high levels of interleukin-17 (IL-17) have been associated with chronic inflammatory diseases with fibrotic complications that culminate in organ failure. In this review, we provide an update on the role of IL-17 in fibrotic diseases, with particular attention to the most recent lines of research in the therapeutic field represented by the epigenetic mechanisms that control IL-17 levels in fibrosis. A better knowledge of the IL-17 signaling pathway implications in fibrosis could design new strategies for therapeutic benefits.

Hepatic vascular changes associated with Opisthorchis felineus infection in Syrian hamsters and humans

The liver fluke Opisthorchis felineus is a foodborne zoonotic pathogen endemic to Russia, Kazakhstan, and several European countries. The adult flukes affect the hepatobiliary system of piscivorous mammals and humans, thereby causing numerous complications, including liver fibrosis. Detailing the mechanisms of progression of the fibrotic complications is a hot topic in the field of research on opisthorchiasis pathogenesis. Pathologic angiogenesis appears to be associated with the fibrogenic progression due to active participation in the recruitment of inflammatory cells and many factors involved in the modulation of the extracellular matrix. The aim of the study was to evaluate neoangiogenesis and amyloid deposits in liver tissues of model animals and patients with confirmed chronic opisthorchiasis. In addition, we assessed a possible correlation of neoangiogenesis with liver fibrosis. We found a significant increase in the number of newly formed vessels and amyloid deposits in the liver of people with chronic opisthorchiasis compared to that of uninfected ones. Thus, for the first time we have demonstrated neoangiogenesis and amyloid deposits during O. felineus infection in a Mesocricetus auratus model. Regression analysis showed that CD34+ newly formed vessels correlate with fibrosis severity in the course of the infection. Our results indicate the potential contribution of angiogenesis to the progression of liver fibrosis, associated with O. felineus infection.

Structures of the interleukin 11 signalling complex reveal gp130 dynamics and the inhibitory mechanism of a cytokine variant

Interleukin (IL-)11, an IL-6 family cytokine, has pivotal roles in autoimmune diseases, fibrotic complications, and solid cancers. Despite intense therapeutic targeting efforts, structural understanding of IL-11 signalling and mechanistic insights into current inhibitors are lacking. Here we present cryo-EM and crystal structures of the human IL-11 signalling complex, including the complex containing the complete extracellular domains of the shared IL-6 family β-receptor, gp130. We show that complex formation requires conformational reorganisation of IL-11 and that the membrane-proximal domains of gp130 are dynamic. We demonstrate that the cytokine mutant, IL-11 Mutein, competitively inhibits signalling in human cell lines. Structural shifts in IL-11 Mutein underlie inhibition by altering cytokine binding interactions at all three receptor-engaging sites and abrogating the final gp130 binding step. Our results reveal the structural basis of IL-11 signalling, define the molecular mechanisms of an inhibitor, and advance understanding of gp130-containing receptor complexes, with potential applications in therapeutic development.

Role of the epithelial barrier in intestinal fibrosis associated with inflammatory bowel disease: relevance of the epithelial-to mesenchymal transition.

In inflammatory bowel disease (IBD), chronic inflammation in the gastrointestinal tract can lead to tissue damage and remodelling, which can ultimately result in fibrosis. Prolonged injury and inflammation can trigger the activation of fibroblasts and extracellular matrix (ECM) components. As fibrosis progresses, the tissue becomes increasingly stiff and less functional, which can lead to complications such as intestinal strictures, obstructive symptoms, and eventually, organ dysfunction. Epithelial cells play a key role in fibrosis, as they secrete cytokines and growth factors that promote fibroblast activation and ECM deposition. Additionally, epithelial cells can undergo a process called epithelial-mesenchymal transition, in which they acquire a more mesenchymal-like phenotype and contribute directly to fibroblast activation and ECM deposition. Overall, the interactions between epithelial cells, immune cells, and fibroblasts play a critical role in the development and progression of fibrosis in IBD. Understanding these complex interactions may provide new targets for therapeutic interventions to prevent or treat fibrosis in IBD. In this review, we have collected and discussed the recent literature highlighting the contribution of epithelial cells to the pathogenesis of the fibrotic complications of IBD, including evidence of EMT, the epigenetic control of the EMT, the potential influence of the intestinal microbiome in EMT, and the possible therapeutic strategies to target EMT. Finally we discuss the pro-fibrotic interactions epithelial-immune cells and epithelial-fibroblasts cells.

The cancer-associated glycan polysialic acid is dysregulated in systemic sclerosis and is associated with fibrosis

ObjectiveSystemic sclerosis (SSc) is a rare but deadly disease characterized by autoimmunity, vasculopathy, and fibrosis. Fibrotic complications associated with SSc correlate with severe morbidity and mortality. Previous studies in SSc have identified fibroblasts as the primary drivers of fibrosis; however, the mechanism(s) promoting this are not well understood. Aberrant glycosylation, particularly polysialylation (polySia), has been described as a prominent feature of aggressive cancers. Inspired by this observation, we aimed to determine if polySia is dysregulated in various forms of SSc. MethodsAll patients with SSc met the 2013 ACR/EULAR. Patients were sub-classified into limited cutaneous (lSSc, N = 5 or 46 patients for polySia quantification in the dermis or serum; respectively), diffuse cutaneous (dSSc, N = 11 or 18 patients for polySia quantification in the dermis or serum; respectively), or patients with dSSc treated with an autologous stem cell transplantation (post-ASCT, N = 4 patients for quantification in the dermis). Dermal polySia levels were measured via immunofluorescence microscopy in 10 μm dermal sections, quantified in each group (healthy volunteers (HC), lSSc, dSSc, and post-ASCT) and correlated with skin fibrosis (via the modified Rodnan skin score (mRSS)). Similarly, serum polySia was quantified in each group, and correlated with the mRSS. ResultsDermal polySia levels were highest in patients with dSSc (compared to HC < 0.001), and correlated with the degree of fibrosis in all of the groups (P = 0.008). Serum polySia was higher in all SSc groups (p < 0.001) and correlated with the severity of mRSS (p < 0.0001). ConclusionPolysia is more abundant in the skin and sera from patients with SSc and correlates with the degree of skin fibrosis. The aberrant expression of polySia highlights its potential use as a biomarker in patients with progressive forms of SSc. Dysregulated polySia levels in SSc further emphasizes the cancer-like phenotype present in SSc, which may promote fibrosis and immune dysregulation.

Pulmonary fibrosis: A short- or long-term sequelae of severe COVID-19?

The pandemic of coronavirus disease 2019 (COVID‑19), caused by a novel severe acute respiratory syndrome (SARS) coronavirus 2 (SARS-CoV-2), has caused an enormous impact on the global healthcare. SARS-CoV-2 infection primarily targets the respiratory system. Although most individuals testing positive for SARS-CoV-2 present mild or no upper respiratory tract symptoms, patients with severe COVID-19 can rapidly progress to acute respiratory distress syndrome (ARDS). ARDS-related pulmonary fibrosis is a recognized sequelae of COVID-19. Whether post-COVID-19 lung fibrosis is resolvable, persistent, or even becomes progressive as seen in human idiopathic pulmonary fibrosis (IPF) is currently not known and remains a matter of debate. With the emergence of effective vaccines and treatments against COVID-19, it is now important to build our understanding of the long-term sequela of SARS-CoV-2 infection, to identify COVID-19 survivors who are at risk of developing chronic pulmonary fibrosis, and to develop effective anti-fibrotic therapies. The current review aims to summarize the pathogenesis of COVID-19 in the respiratory system and highlights ARDS-related lung fibrosis in severe COVID-19 and the potential mechanisms. It envisions the long-term fibrotic lung complication in COVID-19 survivors, in particular in the aged population. The early identification of patients at risk of developing chronic lung fibrosis and the development of anti-fibrotic therapies are discussed.

575 Single-stage Trilaminar Skin Reconstruction Following Full-Thickness Burn Injury

Abstract Introduction Complex burns are highly morbid injuries that can cause severe disfigurement and can be devastating to one’s quality of life and psychosocial well-being. Currently, there are no simple, single-stage procedures available for extensive or multifocal burns to address full-thickness trilaminar defects. Our team has previously demonstrated the viability of an adipose-first reconstruction to address hypodermal defects. In this study, we demonstrate the efficacy of a combined adipose plus finely minced skin to achieve a single-stage trilaminar skin reconstruction. Methods Full-thickness burns were created on female Yorkshire swine. After 48-hours, escharectomies were performed to the level of fascia. The wounds were layered with adipose harvested from female Yorkshire swine. In one group, autologous split-thickness skin grafts were cut into pixel size (0.3x0.3 mm) grafts and layered on top of the adipose. Pigs were maintained for 4-weeks with weekly photography, ultrasound, followed by endpoint histology and tension measurements. Results At the end of the 4-week period, adipose combined with pixel graft demonstrated improved epithelialization and less contracture (p&amp;lt; 0.01). Thickness and mobility measurements were consistent in both groups. This findings were similar to our previous approaches using adipose following surgical debridement. Tissue pliability in the pixel grafting group was maintained to a high degree. Cross sections were performed which showed the persistence of fat graft at the base of the wounds. Conclusions Immediate, single-stage trilaminar reconstruction of full-thickness complex burns reduces contracture, mitigates adhesion, and restores normal soft-tissue thickness, therefore, presenting a paradigm changing approach in the current practice of burn injuries to the mobile surfaces. Applicability of Research to Practice Our results support the therapeutic potential of adipose-based soft-tissue reconstruction of burns to both enhance hypodermal augmentation and mitigate fibrotic complications including contracture and adhesions. Our data suggest that this approach is compatible with the standard of care skin grafting, and in fact provides improved epidermal thickness and pliability.

Endogenously produced hyaluronan contributes to the regulation of peritoneal adhesion development.

Peritoneal adhesions are postsurgical fibrotic complications connected to peritoneal inflammation. The exact mechanism of development is unknown; however, an important role is attributed to activated mesothelial cells (MCs) overproducing macromolecules of extracellular matrix (ECM), including hyaluronic acid (HA). It was suggested that endogenously-produced HA contributes to the regulation of different fibrosis-related pathologies. However, little is known about the role of altered HA production in peritoneal fibrosis. We focused on the consequences of the increased turnover of HA in the murine model of peritoneal adhesions. Changes of HA metabolism were observed in early phases of peritoneal adhesion development in vivo. To study the mechanism, human MCs MeT-5A and murine MCs isolated from the peritoneum of healthy mice were pro-fibrotically activated by transforming growth factor β (TGFβ), and the production of HA was attenuated by two modulators of carbohydrate metabolism, 4-methylumbelliferone (4-MU) and 2-deoxyglucose (2-DG). The attenuation of HA production was mediated by upregulation of HAS2 and downregulation of HYAL2 and connected to the lower expression of pro-fibrotic markers, including fibronectin and α-smooth muscle actin (αSMA). Moreover, the inclination of MCs to form fibrotic clusters was also downregulated, particularly in 2-DG-treated cells. The effects of 2-DG, but not 4-MU, were connected to changes in cellular metabolism. Importantly, the inhibition of AKT phosphorylation was observed after the use of both HA production inhibitors. In summary, we identified endogenous HA as an important regulator of peritoneal fibrosis, not just a passive player during this pathological process.

Transcriptional repression of the MRTF/SRF-cytoskeleton pathway by Rev-erba promotes beigeing via adipogenic progenitor fate switch

The circadian clock exerts temporal control in metabolic processes to maintain homeostasis, with its disruption leading to the development of obesity and insulin resistance. Adipose fibrosis in obese subjects exacerbates insulin resistance by restricting healthy tissue expansion and remodeling. Rev-erbα is a key circadian clock repressor that displays circadian rhythmic expression in adipose tissue, although its role in adipose tissue fibrosis is not known. Here we show that Rev-ebα inhibits the fibrogenic fate of adipocyte progenitors while promoting beige adipogenic potential via transcription repression of the MRTF/SRF-actin cytoskeleton axis. ChIP-seq analysis of Rev-erbα cistrome in adipogenic precursors identified its transcriptional control of pathways involved in cytoskeleton modulation, including established myofibroblast gene markers small muscle α-actin and Tropomysin. Gain-of-function of Rev-erbα in beige adipogenic precursors markedly suppressed MRTF/SRF activity with enhanced beige differentiation, while Rev-erbα silencing suppressed beige adipogenesis. Prrx1-Cre-mediated subcutaneous beige fat-selective Rev-erbα knock-in induced browning with augmented mitochondrial metabolism, resulting in increased energy expenditure, resistance to obesity and insulin sensitivity. Furthermore, single cell RNA-seq of beige progenitors with Rev-erbα overexpression revealed striking loss of preadipcyte-like (PAL) subpopulations with myofibroblastic characteristics that arise from pericyte lineage. PAL beige progenitors displayed enrichment of epithelial mesenchymal transition-related gene signature and contractile program as compared to preadipocytes. Preadipocyte population with Rev-erbα overexpression exhibited activated oxidative phosphorylation pathway with inhibition of myofibrolast characteristics. Taken together, our findings identify a novel regulatory function of Rev-erbα in modulating adipogenic progenitor fate choice that may promote adipose tissue beigeing while suppressing fibrotic complications. NIDDK grant 1R01DK112794, 1R01DK130499 and AR-DMRI 2023 T2D Innovation Grant This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

OA28 CCL24 serum concentration predicts both vascular and fibrotic complications in systemic sclerosis: rationale for a biological target driven basket trial across disease subsets

Abstract Background/Aims CCL24 is a novel target that was found to play a dual role in advancing pro-inflammatory and pro-fibrotic processes in systemic sclerosis (SSc). Previous studies reported that skin and serum CCL24 levels are elevated in SSc and that blocking of CCL24 was effective in preventing and attenuating experimental-induced fibrosis in murine models as well as interfering with endothelial cell activation. Here we tested the concentration of CCL24 in an observational cohort of patients with SSc and available clinical follow-up to determine its clinical value in predicting fibrotic and vascular complications of the disease. Methods Consecutive patients from a single-centre observational cohort were enrolled in this analysis. Clinical data were collected according to the EUSTAR minimal essential data set. Serum Concentration of CCL24 was measured by Luminex assay (Myriad RBM) and defined as “high” for patients over the upper quartile of the healthy control population (110 ng/ml). Interstitial lung disease (ILD) was defined by at least 10% parenchymal involvement at a high-resolution CT scan of the chest, while digital ulcer (DU) disease was defined by the presence of current or history of DU in the previous 6 months. Progressive fibrotic ILD was defined as previously described, according to Erice's criteria within 24 months. Clinical features were compared between CCL24 high vs low by Chi-Square and T-student tests. R software was employed for statistical analysis. Results 189 SSc patients (13% male) fulfilling 2013 ACR/EULAR classification criteria were enrolled in this study. Median (IQR) disease duration was 4 (IQR 2-10) years. 37 (27%) had diffuse cutaneous SSc, 60 (32%) had ILD, and 90 (48%) had DU disease. 52 patients (26%) were CCL24 High. These patients had a higher prevalence of DU (60%, p = 0.042), a higher median (IQR) mRSS [4(2-7) vs 2(0-5), p = 0.036) and showed a higher prevalence of ILD (42% vs 28%, p = 0.055); this was more significant among patients with limited cutaneous SSc (7% vs 12%, p = 0.037). Most importantly, among patients with PF-ILD (19/43 with available 24-month follow-up), 44% had significantly higher CCL24 serum concentration at baseline, compared to stable patients (1150 [817-1593] vs 725 [460-955]; p = 0.017). Consistent with these findings, in patients with ILD, having high CCL24 gave double the chance of progressing within 24 months (66% vs 32% of CCL24 low; p = 0.03). Conclusion We show here that within the context of an observational cohort of unselected patients, CCL24 serum concentration is associated with the presence of DU as well as worse skin and lung fibrotic involvement, suggesting that this molecule may be involved in both vascular and fibrotic manifestations of SSc. These results informed the rationale for a target-enriched basket randomized controlled trial to test the biological and clinical effect of CCL24 inhibition in SSc across cutaneous disease subsets. Disclosure E. De Lorenzis: None. A. Mor: None. R. Ross: None. S. Di Donato: None. R. Aricha: None. H. Levi: None. I. Vaknin: None. F. Del Galdo: Other; FDG received consultancies and research support from Abbvie, AstraZeneca, Boheringer-Ingelheim, Capella, Chemomab, Ergomed, Janssen, Kymab, Mitsubishi-Tanabe.

Carcinoid Syndrome: Preclinical Models and Future Therapeutic Strategies

Carcinoid syndrome represents a debilitating paraneoplastic disease, caused by the secretion of several substances, occurring in about 10-40% of patients with well-differentiated neuroendocrine tumors (NETs). The main signs and symptoms associated with carcinoid syndrome are flushing, diarrhea, hypotension, tachycardia, bronchoconstriction, venous telangiectasia, dyspnea and fibrotic complications (mesenteric and retroperitoneal fibrosis, and carcinoid heart disease). Although there are several drugs available for the treatment of carcinoid syndrome, the lack of therapeutic response, poor tolerance or resistance to drugs are often reported. Preclinical models are indispensable tools for investigating the pathogenesis, mechanisms for tumor progression and new therapeutic approaches for cancer. This paper provides a state-of-the-art overview of in vitro and in vivo models in NETs with carcinoid syndrome, highlighting the future developments and therapeutic approaches in this field.

The landscape of immune dysregulation in Crohn’s disease revealed through single-cell transcriptomic profiling in the ileum and colon

Crohn's disease (CD) is a chronic gastrointestinal disease that is increasing in prevalence worldwide. CD is multifactorial, involving the complex interplay of genetic, immune, and environmental factors, necessitating a system-level understanding of its etiology. To characterize cell-type-specific transcriptional heterogeneity in active CD, we profiled 720,633 cells from the terminal ileum and colon of 71 donors with varying inflammation status. Our integrated datasets revealed organ- and compartment-specific responses to acute and chronic inflammation; most immune changes were in cell composition, whereas transcriptional changes dominated among epithelial and stromal cells. These changes correlated with endoscopic inflammation, but small and large intestines exhibited distinct responses, which were particularly apparent when focusing on IBD risk genes. Finally, we mapped markers of disease-associated myofibroblast activation and identified CHMP1A, TBX3, and RNF168 as regulators of fibrotic complications. Altogether, our results provide a roadmap for understanding cell-type- and organ-specific differences in CD and potential directions for therapeutic development.

A NEW MODEL TO STUDY INTESTINAL FIBROSIS USING IPSC-DERIVED HUMAN EPITHELIAL AND MESENCHYMAL CELLS FROM CROHN’S DISEASE PATIENTS

Abstract INTRODUCTION Intestinal fibrosis is a serious complication of Crohn's disease (CD) and is caused by the excess deposition of extracellular matrix protein. There are no therapies to prevent or treat this and surgical intervention remains the only treatment option. Numerous cell types, including intestinal epithelial and mesenchymal cells, are implicated in this but research efforts are impaired by a lack of in vitro models. Human intestinal organoids (HIOs), derived from induced pluripotent stem cells (iPSCs), are comprised of both of these cell types; therefore iPSC-derived HIOs represent an approach in which an unlimited number of patient specific cells could be generated for such models. Our goal was to confirm the feasibility of using iPSC-derived epithelial and mesenchymal cells from CD patients to model intestinal fibrosis METHODS iPSCs from CD patients with and without fibrotic complications were directed to form HIOs. As iPSC-derived HIOs contain epithelial and mesenchymal cells, the organoids were dissociated to generate purified cultures of epithelial-only HIOs (eHIOs) and mesenchymal cells. Both cell types were cultured with TNFα and TGFβ, and responses were assayed after 8, 24 and 48 hrs. Further assessment on the transcriptomic profile of the cultures was conducted using the Nanostring nCounter Fibrosis Panel. RESULTS Mesenchymal cells treated with TNFα for 48 hrs showed a significant increase in MMP9 expression, whereas TGFβ elicited an upregulation in COL1A1 and COL5A1. Further analysis via Nanostring identified the upregulation of numerous other fibrosis-related genes in response to TNFα stimulation, mainly: CCL2, IL6, MMP7, and MMP9. In eHIO cultures, after 24 hrs of cytokine exposure, we detected a significant upregulation in EMT (NCAD, VIM, and SNAI2) and fibrosis genes (COL1A1, COL5A1, and MMP9), mainly in response to TGFβ and the combination TNFα/TGFβ. Nanostring further identified a total of 121 differentially expressed genes, mostly in response to these treatments, particularly: CCL2, IL11, MMP9, MMP10. Overall, Nanostring analysis found an upregulation in pathways associated with ECM production and remodeling, immunomodulation, and ligands associated with EMT and cell migration. CONCLUSION We have successfully generated a system to assay intestinal fibrosis in a patient-specific manner using iPSC-derived epithelial and mesenchymal cells from CD patients. Our model elicited a reliable and reproducible response to inflammatory and fibrogenic stimuli, measured by the differential expression of key fibrosis-associated genes. Future studies will focus on a broader analysis of these data via RNA-seq to investigate a potential fibrogenic phenotype and to identify novel genes/pathways that may play in role in the pathophysiology of intestinal fibrosis in CD.

Atmospheric Plasma Lingual Frenectomy Followed by Post Operative Tongue Exercises: A Case Series.

The lingual frenulum is a submucosal component significantly involved in the mobility of the tongue. In the case of short lingual frenulum, different surgical approaches have been proposed. Atmospheric plasma is a thermal technique of vaporization or sublimation of the superficial tissues, without going deep, and the resulting fine carbonized layer avoids bleeding. The aim of the present investigation was to evaluate the effectiveness of atmospheric plasma (voltaic arc dermabrasion) for the frenectomy of a short lingual frenulum. A total of 30 patients with an age range between 6-11 years old and a class III/IV Kotlow's ankyloglossia classification were included in the study. The Kotlow's free-tongue, maximal interincisal mouth opening (MIO, mm) and interincisal mouth opening with tongue tip to maxillary incisive papillae at roof of mouth (MOTTIP, mm) were calculated at the baseline, immediately postoperatively (T0), at one week (T1), one month (T2) and two months (T3). A significant increase of Kotlow's measurements, MOTTIP and MIO were detected when comparing the baseline and the T0 (p &lt; 0.05). No significant difference was detected between the T0, T1 and T2 (p &gt; 0.05). The atmospheric plasma demonstrated a very minimal invasive approach for frenectomy, without important or fibrotic complications and with very low recurrence rates.