Animal Models Of Fibrosis Research Articles

Efficacy and safety of Treamid in the rehabilitation of patients after COVID-19 pneumonia: a phase 2, randomized, double-blind, placebo-controlled trial

BackgroundMany patients who recovered from COVID are still suffering from pulmonary dysfunction that can be persistent even for months after infection. Therefore, treatment to prevent irreversible impairment of lung function is needed. Treamid (bisamide derivative of dicarboxylic acid, BDDA) was shown to have anti-inflammatory and antifibrotic effects in animal models of pulmonary fibrosis. This study was designed to assess the safety, tolerability, and efficacy of Treamid in the rehabilitation of patients after COVID pneumonia. The aim was to establish whether Treamid could be effective in ameliorating post-COVID sequelae.MethodsThe phase 2, randomized, double-blind, placebo-controlled clinical trial was done at 8 medical centers in Russia. Patients with a diagnosis of COVID in the past medical history (with the first symptoms of COVID appear no earlier than 2 months before screening) and having fibrotic changes in the lungs, decreased lung function (percentage of predicted FVC and/or DLCO < 80%), and moderate or severe dyspnea according to mMRC scale were enrolled and randomly assigned in a 1:1 ratio (stratified by the initial degree of lung damage, age, and concomitant chronic diseases) by use of interactive responsive technology to peroral administration of Treamid 50 mg or placebo once a day for 4 weeks. The primary outcome was the proportion of patients who achieved clinically significant improvement in FVC and/or DLCO (defined as a relative increase in FVC of ≥ 10% or a relative increase in FVC in the range of ≥ 5 to < 10% plus a relative increase in DLCO of ≥ 15%) at week 4 compared with baseline. Secondary endpoints included changes from baseline in dyspnea scoring evaluated by the modified Borg and mMRC scales, pulmonary function (FEV1, FVC, FEV1/FVC ratio, DLCO, TLC, FRC), 6-min walk distance, the overall score of the KBILD questionnaire, and the proportion of patients with a reduction in the degree of lung damage assessed by CT scores. This trial was registered on ClinicalTrials.gov (Identifier: NCT04527354). The study was fully funded by PHARMENTERPRISES LLC.Results12 out of 29 patients (41%) in Treamid group achieved clinically significant improvement in FVC and/or DLCO compared to 5 out of 30 patients (17%) in placebo group (p = 0.036). There was a significant decrease of dyspnea according to modified Borg scale observed in the Treamid group (− 0.9 ± 0.7 vs. − 0.4 ± 0.8, p = 0.018). No significant differences in the adverse events were noted. Exploratory analysis of the female population indicated superiority of Treamid over placebo by decreasing dyspnea and the extent of lung damage as well as increasing TLC.Conclusions4 weeks oral administration of 50 mg Treamid was associated with clinically significant improvement in the post-COVID patients, evident by an increase in FVC and/or DLCO as well as decreasing dyspnea. Treamid was well tolerated and can be safely administered to patients discharged after COVID. Treamid was more effective in women visible by superior improvement of COVID sequalae after 4 weeks treatment. Considering that female gender is a risk factor associated with the development of post-COVID symptoms, Treamid might offer a pharmacological treatment for long-term sequalae after COVID and supports further investigation in future clinical trials in post-COVID patients.

Stain-Independent Deep Learning–Based Analysis of Digital Kidney Histopathology

Convolutional neural network (CNN)-based image analysis applications in digital pathology (eg, tissue segmentation) require a large amount of annotated data and are mostly trained and applicable on a single stain. Here, a novel concept based on stain augmentation is proposed to develop stain-independent CNNs requiring only one annotated stain. In this benchmark study on stain independence in digital pathology, this approach is comprehensively compared with state-of-the-art techniques including image registration and stain translation, and several modifications thereof. A previously developed CNN for segmentation of periodic acid-Schiff-stained kidney histology was used and applied to various immunohistochemical stainings. Stain augmentation showed very high performance in all evaluated stains and outperformed all other techniques in all structures and stains. Without the need for additional annotations, it enabled segmentation on immunohistochemical stainings with performance nearly comparable to that of the annotated periodic acid-Schiff stain and could further uphold performance on several held-out stains not seen during training. Herein, examples of how this framework can be applied for compartment-specific quantification of immunohistochemical stains for inflammation and fibrosis in animal models and patient biopsy specimens are presented. The results show that stain augmentation is a highly effective approach to enable stain-independent applications of deep-learning segmentation algorithms. This opens new possibilities for broad implementation in digital pathology.

E2F1 regulates miR-215-5p to aggravate paraquat-induced pulmonary fibrosis via repressing BMPR2 expression.

Pulmonary fibrosis is considered to be an irreversible lung injury, which can be caused by paraquat (PQ) poisoning. MiRNAs have been demonstrated crucial roles in pulmonary fibrosis caused by numerous approaches including PQ induction. The purpose of this study was to investigate the role and the underlying mechanism of miR-215 in PQ-induced pulmonary fibrosis. The cell and animal models of pulmonary fibrosis were established through PQ intervention. Cell viability was performed to test by MTT assay. Immunofluorescence assay was used to detect COL1A1 expression and its location. The relationships among E2F1, miR-215-5p, and BMPR2 were validated by dual luciferase reporter gene assay, chromatin immunoprecipitation and RNA-binding protein immunoprecipitation. Lung morphology was evaluated by hematoxylin and eosin staining. MiR-215-5p was upregulated in PQ-induced pulmonary fibrosis in vitro and in vivo. MiR-215-5p silencing relieved PQ-induced pulmonary fibrosis progression by enhancing cell viability and reducing the expression of fibrosis-related markers (COL1A1, COL3A1, and α-SMA). Mechanistically, miR-215-5p directly targeted BMRP2. BMPR2 knockdown abolished the suppressive effects of miR-215-5p knockdown on PQ-induced pulmonary fibrosis. In addition, E2F1 interacted with miR-215-5p promoter and positively regulated miR-215-5p expression. E2F1 downregulation reduced miR-215-5p level and promoted BMPR2 level via regulating TGF-β/Smad3 pathway, and then suppressed PQ-induced pulmonary fibrosis, whereas these effects were compromised by miR-215-5p sufficiency. MiR-215-5p was activated by E2F1 to repress BMPR2 expression and activate TGF-β/Smad3 pathway, which aggravated PQ-induced pulmonary fibrosis progression. Targeting the E2F1/miR-215-5p/BMPR2 axis might be a new approach to alleviate PQ-induced pulmonary fibrosis.

Deletion of Smad7 Ameliorates Intestinal Inflammation and Contributes to Fibrosis.

Patients suffering from inflammatory bowel diseases (IBDs) express increased mucosal levels of transforming growth factor (TGF)-β compared with non-IBD controls. SMAD7 negatively regulates TGF-β signaling. An earlier study aiming to target Smad7 showed a lack of clinical benefit. It remains unknown whether inhibition of SMAD7 is beneficial in specific settings of IBD. We evaluated the effect of Smad7 deficiency on inflammation, fibrogenesis, and wound healing. For the initiation of fibrosis in Smad7-/- (Smad7Δex-I) CD-1 mice, the dextran sodium sulfate-induced chronic colitis model and the heterotopic transplantation model of fibrosis were used. Wound closure of fibroblasts from Smad7-/- mice was determined using culture inserts and electric cell-substrate impedance sensing in vitro. In dextran sodium sulfate-induced chronic colitis, Smad7 deficiency was associated with ameliorated inflammation, as evidenced by decreased clinical score, histological score, and myeloperoxidase activity. Absence of SMAD7 decreased T-cell accumulation in colonic tissue and tumor necrosis factor (TNF) mRNA expression levels. Smad7-/- mice showed a significant increase in hydroxyproline and collagen content, as well as ColIVa1 mRNA expression. Wild type mice transplanted with terminal ileum from Smad7-/- mice in the heterotopic animal model for intestinal fibrosis showed a significant increase in collagen content and protein expression of α-smooth muscle actin. Smad7 deficiency is associated with a decrease in intestinal inflammation and an increase in fibrosis. Targeting SMAD7 constitutes a potential new treatment option for IBD; progression of disease-associated fibrosis should be considered.

Components of impedance in a cochlear implant animal model with TGFβ1-accelerated fibrosis

Outcomes of cochlear implantation are likely influenced by the biological state of the cochlea. Fibrosis is a pathological change frequently seen in implanted ears. The goal of this work was to investigate the relationship between fibrosis and impedance. To that end, we employed an animal model of extensive fibrosis and tested whether aspects of impedance differed from controls. Specifically, an adenovirus with a TGF-β1 gene insert (Ad.TGF-β1) was injected into guinea pig scala tympani to elicit rapid onset fibrosis and investigate the relation between fibrosis and impedance. We found a significant correlation between treatment and rate of impedance increase. A physical circuit model of impedance was used to separate the effect of fibrosis from other confounding factors. Supported by preliminary, yet nonconclusive, electron microscopy data, this modeling suggested that deposits on the electrode surface are an important contributor to impedance change over time.

A lung targeted miR-29 mimic as a therapy for pulmonary fibrosis.

SummaryBackgroundMicroRNAs are non-coding RNAs that negatively regulate gene networks. Previously, we reported that systemically delivered miR-29 mimic MRG-201 reduced fibrosis in animal models, supporting the consideration of miR-29-based therapies for idiopathic pulmonary fibrosis (IPF).MethodsWe generated MRG-229, a next-generation miR-29 mimic based on MRG-201 with improved chemical stability due to additional sugar modifications and conjugation with the internalization moiety BiPPB (PDGFbetaR-specific bicyclic peptide)1. We investigated the anti-fibrotic efficacy of MRG-229 on TGF-β1 treated human lung fibroblasts (NHLFs), human precision cut lung slices (hPCLS), and in vivo bleomycin studies; toxicology was assessed in two animal models, rats, and non-human primates. Finally, we examined miR-29b levels in a cohort of 46 and 213 patients with IPF diagnosis recruited from Yale and Nottingham Universities (Profile Cohort), respectively.FindingsThe peptide-conjugated MRG-229 mimic decreased expression of pro-fibrotic genes and reduced collagen production in each model. In bleomycin-treated mice, the peptide-conjugated MRG-229 mimic downregulated profibrotic gene programs at doses more than ten-fold lower than the original compound. In rats and non-human primates, the peptide-conjugated MRG-229 mimic was well tolerated at clinically relevant doses with no adverse findings observed. In human peripheral blood from IPF patients decreased miR-29 concentrations were associated with increased mortality in two cohorts potentially identified as a target population for treatment.InterpretationCollectively, our results provide support for the development of the peptide-conjugated MRG-229 mimic as a potential therapy in humans with IPF.FundingThis work was supported by NIH NHLBI grants UH3HL123886, R01HL127349, R01HL141852, U01HL145567.

Serum Galectin-3 and Mucin-1 (CA15-3) in Relation to Renal Function in Untreated Chinese Patients.

Galectin-3 is a multi-functional lectin protein and a ligand of mucin-1 (CA15-3), and has been linked to renal fibrosis in animal models and renal function in humans. However, no population study has ever explored the associations with both ligand and receptor. We therefore investigate the independent association of renal function with serum galectin-3 and mucin-1 (CA15-3) in untreated Chinese patients. The study participants were outpatients who were suspected of hypertension, but had not been treated with antihypertensive medication. Serum galectin-3 and mucin-1 (CA15-3) concentrations were both measured by the enzyme-linked immunosorbent assay (ELISA) method. Estimated glomerular filtration rate (eGFR) was calculated from serum creatinine by the use of the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. The 1,789 participants included 848 (47.4%) men. Mean (±SD) age was 51.3 ± 10.7 years. Multiple regression analyses showed that eGFR was significantly associated with serum galectin-3 and mucin-1 (CA15-3) concentration (0.68 and 1.32 ml/min/1.73 m2 decrease per 1-SD increase in log transformed serum galectin-3 and mucin-1 (CA15-3) concentration, respectively; P ≤ 0.006). The association of eGFR with serum mucin-1 (CA15-3) concentration was significantly stronger in the overweight (BMI 24.0-27.9 kg/m2) and obese (BMI ≥ 28.0 kg/m2) than in normal weight subjects (BMI < 24.0 kg/m2, P for interaction 0.018). Path analysis showed that serum galectin-3 concentration had both a direct (P = 0.016) and a mucin-1 mediated indirect effect (P = 0.014) on eGFR. Both circulating galectin-3 and mucin-1 (CA15-3) were significantly associated with renal function. The role of galectin-3 on renal function might be partially via mucin-1.

Janus kinase 2 inhibition by pacritinib as potential therapeutic target for liver fibrosis.

Janus kinase 2 (JAK2) signaling is increased in human and experimental liver fibrosis with portal hypertension. JAK2 inhibitors, such as pacritinib, are already in advanced clinical development for other indications and might also be effective in liver fibrosis. Here, we investigated the antifibrotic role of the JAK2 inhibitor pacritinib on activated hepatic stellate cells (HSCs) in vitro and in two animal models of liver fibrosis in vivo . Transcriptome analyses of JAK2 in human livers and other targets of pacritinib have been shown to correlate with profibrotic factors. Although transcription of JAK2 correlated significantly with type I collagen expression and other profibrotic genes, no correlation was observed for interleukin-1 receptor-associated kinase and colony-stimulating factor 1 receptor. Pacritinib decreased gene expression of fibrosis markers in mouse primary and human-derived HSCs in vitro . Moreover, pacritinib decreased the proliferation, contraction, and migration of HSCs. C 57 BL/6J mice received ethanol in drinking water (16%) or Western diet in combination with carbon tetrachloride intoxication for 7 weeks to induce alcoholic or nonalcoholic fatty liver disease. Pacritinib significantly reduced liver fibrosis assessed by gene expression and Sirius red staining, as well as HSC activation assessed by alpha-smooth muscle actin immunostaining in fibrotic mice. Furthermore, pacritinib decreased the gene expression of hepatic steatosis markers in experimental alcoholic liver disease. Additionally, pacritinib protected against liver injury as assessed by aminotransferase levels. This study demonstrates that the JAK2 inhibitor pacritinib may be promising for the treatment of alcoholic and nonalcoholic liver fibrosis and may be therefore relevant for human pathology.

Thy-1 plays a pathogenic role and is a potential biomarker for skin fibrosis in scleroderma.

Thy-1 (CD90) is a well-known marker of fibroblasts implicated in organ fibrosis, but its contribution to skin fibrosis remains unknown. We examined Thy-1 expression in scleroderma skin and its potential role as a biomarker and pathogenic factor in animal models of skin fibrosis. Skin from patients with systemic sclerosis demonstrated markedly elevated Thy-1 expression compared with controls, colocalized with fibroblast activator protein in the deep dermis, and correlated with the severity of skin involvement (modified Rodnan skin score). Serial imaging of skin from Thy-1 yellow fluorescent protein reporter mice by IVIS showed an increase in Thy-1 expression that correlated with onset and progression of fibrosis. In contrast to lung fibrosis, Thy-1-KO mice had attenuated skin fibrosis in both bleomycin and tight skin-1 murine models. Moreover, Thy-1 regulated key pathogenic pathways involved in fibrosis, including inflammation, myofibroblast differentiation, apoptosis, and multiple additional canonical fibrotic pathways. Therefore, although Thy-1 deficiency leads to exacerbated lung fibrosis, in skin it is protective. Moreover, Thy-1 may serve as a longitudinal marker to assess skin fibrosis.

Endotrophin, a Collagen VI Formation–Derived Peptide, in Heart Failure

BackgroundEndotrophin, a collagen type VI–derived peptide, mediates metabolic dysregulation, inflammation, and fibrosis in animal models, but has not been studied in human heart failure (HF).MethodsWe examined the association between circulating endotrophin and outcomes in participants suffering from HF with preserved ejection fraction (HFpEF) enrolled in the TOPCAT trial (n=205). Associations were validated in a participant-level meta-analysis (n=810) that included participants with HFpEF from the PHFS study (United States; n=174), PEOPLE cohort (New Zealand; n=168), a randomized trial of vasodilator therapy (United States; n=45), a cohort from Donostia University Hospital and University of Navarra (Spain; n=171), and the TRAINING-HF trial (Spain; n=47). We also assessed associations in HF with reduced ejection fraction in PHFS (n=1,642).ResultsPlasma endotrophin levels at baseline were associated with risk of future death (standardized hazard ratio [HR]=1.74; 95% confidence interval [CI]=1.36–2.24; P<0.001) and death or HF-related hospital admission (DHFA; standardized HR=2.11; 95% CI=1.67–2.67; P<0.001) in TOPCAT. Endotrophin improved reclassification and discrimination for these outcomes beyond the MAGGIC risk score and NT-proBNP (N-terminal pro b-type natriuretic peptide). Findings were confirmed in the participant-level meta-analysis. In participants with HF with reduced ejection fraction in PHFS, endotrophin levels were associated with death (standardized HR=1.82; 95% CI=1.66–2.00; P<0.001) and DHFA (standardized HR=1.40; 95% CI=1.31–1.50; P<0.001), but the strength of the latter association was substantially lower than for the MAGGIC risk score (standardized HR=1.93; 95% CI=1.76–2.12) and BNP (standardized HR=1.78; 95% CI=1.66–1.92).ConclusionsCirculating endotrophin levels are independently associated with future poor outcomes in patients with HF, particularly in HFpEF. (Funded by Bristol Myers Squibb; Instituto de Salud Carlos III [Spain] and European Regional Development Fund; European Commission CRUCIAL project; and the U.S. National Institutes of Health National Heart, Lung, and Blood Institute.)

Randomized double-blind clinical study in patients with COVID-19 to evaluate the safety and efficacy of a phytomedicine (P2Et).

BackgroundIt has been proposed that polyphenols can be used in the development of new therapies against COVID-19, given their ability to interfere with the adsorption and entrance processes of the virus, thus disrupting viral replication. Seeds from Caesalpinia spinosa, have been traditionally used for the treatment of inflammatory pathologies and respiratory diseases. Our team has obtained an extract called P2Et, rich in polyphenols derived from gallic acid with significant antioxidant activity, and the ability to induce complete autophagy in tumor cells and reduce the systemic inflammatory response in animal models.MethodsIn this work, a phase II multicenter randomized double-blind clinical trial on COVID-19 patients was designed to evaluate the impact of the P2Et treatment on the clinical outcome and the immunological parameters related to the evolution of the disease. The Trial was registered with the number No. NCT04410510*. A complementary study in an animal model of lung fibrosis was carried out to evaluate in situ lung changes after P2Et in vivo administration. The ability of P2Et to inhibit the viral load of murine and human coronaviruses in cellular models was also evaluated.ResultsPatients treated with P2Et were discharged on average after 7.4 days of admission vs. 9.6 days in the placebo group. Although a decrease in proinflammatory cytokines such as G-CSF, IL-15, IL-12, IL-6, IP10, MCP-1, MCP-2 and IL-18 was observed in both groups, P2Et decreased to a greater extent G-CSF, IL-6 and IL-18 among others, which are related to lower recovery of patients in the long term. The frequency of T lymphocytes (LT) CD3+, LT double negative (CD3+CD4-CD8-), NK cells increased in the P2Et group where the population of eosinophils was also significantly reduced. In the murine bleomycin model, P2Et also reduced lung inflammation and fibrosis. P2Et was able to reduce the viral replication of murine and human coronaviruses in vitro, showing its dual antiviral and anti-inflammatory role, key in disease control.ConclusionsTaken together these results suggest that P2Et could be consider as a good co-adjuvant in the treatment of COVID-19.Clinical trail registrationhttps://clinicaltrials.gov/ct2/show/NCT04410510, identifier: NCT04410510.

Salvianolic acid B suppresses hepatic stellate cell activation and liver fibrosis by inhibiting the NF-κB signaling pathway via miR-6499-3p/LncRNA-ROR

BackgroundLong non-coding RNA (LncRNAs) have been reported to play an important role in liver fibrosis and are closely associated with hepatic stellate cell (HSC) activation. We previously found that salvianolic acid B (Sal B) improves liver fibrosis by regulating the NF-κB signaling pathway. However, whether the LncRNA, regulator of reprogramming (LncRNA-ROR) plays a role in Sal B-mediated anti-fibrosis effects via the NF-κB signaling pathway remain unclear. PurposeThis study aimed to evaluate the effects of Sal B on HSC activation and liver fibrosis and investigate its mechanism from the perspective of LncRNA-ROR-mediated NF-κB signaling pathways. MethodsLX-2 and T6 cell lines were cultured. Animal models of liver fibrosis were established using CCl4 in male BALB/c mice. Primary HSCs were isolated from mice and cultured. Serum biochemical and liver histological analyses were performed to evaluate the effects of Sal B on liver fibrosis. The index of HSC activation and the expression of LncRNA-ROR, microRNAs (miRNAs), and inflammatory factors were determined by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) or immunofluorescence staining. Cell proliferation was measured by a Cell Counting Kit-8 (CCK-8). NF-κB signaling-associated protein levels were assessed using western blotting or immunofluorescence staining. A luciferase reporter assay was used to detect transcription activity. ResultsIn this study, a lower level of LncRNA-ROR was found during Sal B attenuating HSC activation in HSCs. Mechanistically, Sal B impeded the NF-κB signaling pathway to inhibit HSC proliferation and activation by downregulating LncRNA-ROR. Additionally, Sal B upregulated miR-6499-3p to target LncRNA-ROR for degradation. Functionally, Sal B treatment ameliorated CCl4-induced liver fibrosis in mice by inhibiting HSC activation. ConclusionSal B suppresses HSC activation and liver fibrosis via regulation of miR-6499-3p/LncRNA-ROR-mediated NF-κB signaling pathway. These results reveal a new molecular mechanism of Sal B on liver fibrosis from the insight of LncRNAs.

Saracatinib, a Selective Src Kinase Inhibitor, Blocks Fibrotic Responses in Preclinical Models of Pulmonary Fibrosis.

Rationale: Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and often fatal disorder. Two U.S. Food and Drug Administration-approved antifibrotic drugs, nintedanib and pirfenidone, slow the rate of decline in lung function, but responses are variable and side effects are common. Objectives: Using an in silico data-driven approach, we identified a robust connection between the transcriptomic perturbations in IPF disease and those induced by saracatinib, a selective Src kinase inhibitor originally developed for oncological indications. Based on these observations, we hypothesized that saracatinib would be effective at attenuating pulmonary fibrosis. Methods: We investigated the antifibrotic efficacy of saracatinib relative to nintedanib and pirfenidone in three preclinical models: 1) invitro in normal human lung fibroblasts; 2) invivo in bleomycin and recombinant Ad-TGF-β (adenovirus transforming growth factor-β) murine models of pulmonary fibrosis; and 3) ex vivo in mice and human precision-cut lung slices from these two murine models as well as patients with IPF and healthy donors. Measurements and Main Results: In each model, the effectiveness of saracatinib in blocking fibrogenic responses was equal or superior to nintedanib and pirfenidone. Transcriptomic analyses of TGF-β-stimulated normal human lung fibroblasts identified specific gene sets associated with fibrosis, including epithelial-mesenchymal transition, TGF-β, and WNT signaling that was uniquely altered by saracatinib. Transcriptomic analysis of whole-lung extracts from the two animal models of pulmonary fibrosis revealed that saracatinib reverted many fibrogenic pathways, including epithelial-mesenchymal transition, immune responses, and extracellular matrix organization. Amelioration of fibrosis and inflammatory cascades in human precision-cut lung slices confirmed the potential therapeutic efficacy of saracatinib in human lung fibrosis. Conclusions: These studies identify novel Src-dependent fibrogenic pathways and support the study of the therapeutic effectiveness of saracatinib in IPF treatment.

Negative Feedback of the cAMP/PKA Pathway Regulates the Effects of Endoplasmic Reticulum Stress-Induced NLRP3 Inflammasome Activation on Type II Alveolar Epithelial Cell Pyroptosis as a Novel Mechanism of BLM-Induced Pulmonary Fibrosis.

Endoplasmic reticulum stress (ER stress) contributes to the development of pulmonary fibrosis, especially in type II alveolar epithelial cells (AECs) apoptosis. ER stress also promotes NLRP3 inflammasome activation which is inhibited by upregulation of cAMP/PKA pathway. However, it is confused whether ER stress-induced NLRP3 inflammasome activation and pyroptosis in type II alveolar epithelial cells which exacerbates pulmonary fibrosis via a mechanism that is suppressed by cAMP/PKA pathway. In our research, we explored that potential links among NLRP3 inflammasome, ER stress, and cAMP/PKA pathway in type II AECs to explain the new mechanisms of pulmonary fibrosis. We found that in vivo, ER stress, NLRP3 inflammasome, and PKA upregulated in the alveolar epithelial area in animal models of pulmonary fibrosis. In addition, immunofluorescence staining further confirmed that ER stress, NLRP3 inflammasome, and cAMP/PKA had potential links on type II AECs in BLM group. In vitro, ER stress stimulated NLRP3 inflammasome activation, promoted pyroptosis, and also upregulated cAMP/PKA pathway. Upregulation of cAMP/PKA pathway inhibited ER stress-induced pyroptosis of A549 cells and vice versa. These results initially supported conclusion that ER stress may stimulate NLRP3 inflammasome activation and pyroptosis in type II AECs, which exacerbated pulmonary fibrosis, and cAMP/PKA pathway may act as a feedback regulator.

A novel approach to develop an animal model for oral submucous fibrosis

Epidemiological data have proved the association of consumption of areca nut with the causation of oral submucous fibrosis (OSF). OSF is a chronic inflammatory disease with the potential for malignant transformation from 7 to 13%. The establishment of animal models makes it easier for researchers to focus on the therapeutic options to combat this disease further. We developed and compared two areca nut extract (ANE) administration methods in Swiss albino mice to establish OSF. This study compared an invasive intrabuccal injection technique with a non-invasive intraoral droplet administration. The duration of induction was around 12weeks. Histopathology (H&E, Masson's trichrome staining) and gene expression analysis (COL-I, COL-II, and α-SMA) were performed using RT-PCR to confirm the OSF in animals. Our study showed that ANE administration through the intraoral droplet method exhibited significantly higher fibrosis than the intrabuccal injections, as evidenced by the H&E and Masson's trichrome staining. Furthermore, intraoral administration of ANE significantly upregulated the mRNA expression of COL-I, COL-II, and α-SMA, as revealed by the RT-PCR analysis. The non-invasive droplet method could simulate the absorption of areca nut seen in humans through daily dosing. This study establishes the intraoral droplet method as an efficient and non-invasive method to administer the ANE to develop OSF. These findings will aid in the efficient development of OSF animal models for interventional studies, including screening novel drugs in the reversal of the OSF.

Protective effect of ebselen on bleomycin-induced lung fibrosis: analysis of the molecular mechanism of lung fibrosis mediated by oxidized diacylglycerol

The molecular mechanisms underlying the development of pulmonary fibrosis remain unknown, and effective treatments have not yet been developed. It has been shown that oxidative stress is involved in lung fibrosis. Oxidized diacylglycerol (DAG) produced by oxidative stress is thought to play an important role in lung fibrosis. This study assessed the effect of oxidized DAG in an animal model of pulmonary fibrosis induced by aspiration of bleomycin (BLM) into the lungs. The inhibitory effect of ebselen on pulmonary fibrosis was also investigated. In lung fibrotic tissue induced by BLM, an increase in lipid peroxides and collagen accumulation was observed. Moreover, the levels of oxidized DAG, which has strong protein kinase C (PKC) activation activity, were significantly increased over time following the administration of BLM. Western blotting showed that phosphorylation of PKCα and δ isoforms was increased by BLM. Oral administration of ebselen significantly suppressed the increase in oxidized DAG induced by BLM and improved lung fibrosis. PKCα and δ phosphorylation were also significantly inhibited. The mRNA expression of α-smooth muscle actin and collagen I (marker molecules for fibrosis), as well as the production of transforming growth factor-β and tumor necrosis factor-α(a potentially important factor in the fibrotic process), were increased by BLM and significantly decreased by ebselen. The administration of BLM may induce lipid peroxidation in lung tissue, while the oxidized DAG produced by BLM may induce overactivation of PKCα and δ, resulting in the induction of lung fibrosis.

PGC1α plays a pivotal role in renal fibrosis via regulation of fatty acid metabolism in renal tissue.

Renal fibrosis is a common and irreversible pathological feature of end-stage renal disease caused by multiple etiologies. The role of inflammation in renal fibrosis tissue has been generally accepted. The latest view is that fatty acid metabolism disorder contributes to renal fibrosis. peroxisome proliferator activated receptor-gamma coactivator 1α (PGC1α) plays a key role in fatty acid metabolism, regulating fatty acid uptake and oxidized protein synthesis, preventing the accumulation of lipid in the cytoplasm, and maintaining a dynamic balanced state of intracellular lipid. In multiple animal models of renal fibrosis caused by acute or chronic kidney disease, or even age-related kidney disease, almost all of the kidney specimens show the down-regulation of PGC1α. Upregulation of PGC1α can reduce the degree of renal fibrosis in animal models, and PGC1α knockout animals exhibit severe renal fibrosis. Studies have demonstrated that AMP-activated protein kinase (AMPK), MAPK, Notch, tumor necrosis factor-like weak inducer of apoptosis (TWEAK), epidermal growth factor receptor (EGFR), non-coding RNA (ncRNAs), liver kinase B1 (LKB1), hairy and enhancer of split 1 (Hes1), and other pathways regulate the expression of PGC1α and affect fatty acid metabolism. But some of these pathways interact with each other, and the effect of the integrated pathway on renal fibrosis is not clear.

New Drugs for Hepatic Fibrosis.

The morbidity and mortality of hepatic fibrosis caused by various etiologies are high worldwide, and the trend is increasing annually. At present, there is no effective method to cure hepatic fibrosis except liver transplantation, and its serious complications threaten the health of patients and cause serious medical burdens. Additionally, there is no specific drug for the treatment of hepatic fibrosis, and many drugs with anti-hepatic fibrosis effects are in the research and development stage. Recently, remarkable progress has been made in the research and development of anti-hepatic fibrosis drugs targeting different targets. We searched websites such as PubMed, ScienceDirect, and Home-ClinicalTrials.gov and found approximately 120 drugs with anti-fibrosis properties, some of which are in phase Ⅱ or Ⅲ clinical trials. Additionally, although these drugs are effective against hepatic fibrosis in animal models, most clinical trials have shown poor results, mainly because animal models do not capture the complexity of human hepatic fibrosis. Besides, the effect of natural products on hepatic fibrosis has not been widely recognized at home and abroad. Furthermore, drugs targeting a single anti-hepatic fibrosis target are prone to adverse reactions. Therefore, currently, the treatment of hepatic fibrosis requires a combination of drugs that target multiple targets. Ten new drugs with potential for development against hepatic fibrosis were selected and highlighted in this mini-review, which provides a reference for clinical drug use.

Insights from Transcriptomics: CD163+ Profibrotic Lung Macrophages in COVID-19.

Coronavirus disease (COVID-19) begins with upper airway symptoms but proceeds in a significant proportion of patients to life-threatening infection of the lower respiratory tract, where an exuberant inflammatory response, edema, and adverse parenchymal remodeling impair gas exchange. Respiratory failure is caused initially by flooding of the airspaces with plasma exudate, sloughed epithelium, and inflammatory cells. For many patients with COVID-19, this acute phase has been observed to give way to a prolonged course of acute respiratory distress syndrome, and a significant proportion of patients go on to develop fibroproliferative remodeling of the lung parenchyma, which lengthens the duration of respiratory impairment and mechanical ventilation. Monocyte-derived macrophages have previously been implicated in the fibrotic phase of lung injury in multiple models. From several recent studies that used single-cell genomic techniques, a profile of the transcriptomic state of COVID-19 lung macrophages has emerged. Linkages have been made between these macrophages, which are monocyte-derived and CD163+, and profibrotic macrophages found in other contexts, including animal models of fibrosis and idiopathic pulmonary fibrosis. Here, emerging concepts of macrophage profibrotic function in COVID-19 are highlighted with a focus on gaps in knowledge to be addressed by future research.

735-P: Direct Anti-Inflammatory and Antifibrotic Effects of a Novel Long-Acting Glucagon/GIP/GLP-1 Triple Agonist, HM15211, in Thioacetamide-Induced Mouse Model of Liver Injury and Fibrosis

HM152 is a novel long-acting triple agonist consisting of Glucagon/GIP/GLP-1 triple agonist conjugated to human IgG FC fragment via short PEG linker. Previously, therapeutic benefits of HM152 were demonstrated in diet-induced animal models of NASH and fibrosis. Here, direct anti-inflammatory and -fibrotic effects of HM152 were further evaluated in TAA (thioacetamide) -induced liver injury and fibrosis mouse, and investigate underlying mechanism. To induce liver injury and fibrosis, gradually increased dose of TAA was injected to mouse for 12 weeks, and HM152 was administered during last weeks. Interestingly, HM152 treatment significantly reduced hepatic hydroxyproline (-51% vs. Veh, p&amp;lt;0.01) , Sirius red positive area (-65% vs. Veh, p&amp;lt;0.001) , and fibrosis score (0.7 for HM152 vs. 3.0 for Veh, p&amp;lt;0.001) . Considering baseline fibrosis score at week 2 (1.0) , HM152 could confer both potential reversal effect on pre-existing fibrosis and prevention effect on fibrogenesis. Consistently, expression of hepatic marker genes for fibrosis (i.e. collagen-1α1) and inflammation (i.e. F4/80, TNF-α) were significantly reduced in HM152 group. Furthermore, multiplex cytokine analysis revealed that HM152 treatment was associated with robust reduction across pro-inflammatory cytokines including TNF-α, IL-1β, and IL-6. Significant reduction in blood level of liver enzymes was also confirmed. Mechanistically, PMA/LPS-induced pro-inflammatory cytokine secretion of THP-1 cell was significantly attenuated by HM15211. TGF-β-induced collagen production was also reduced in LX2 cell. In conclusion, HM152 markedly improved liver inflammation and fibrosis in TAA mice, and related mechanism was elaborated by in vitro studies. Thus, HM152 could be a novel therapeutic option for fibrosis due to NASH. Human study is ongoing to assess the clinical relevance of these findings. Disclosure J.Kim: None. S.Lee: n/a. I.Choi: None. J.Lee: None. Y.Kim: None. S.Lee: None. H.Kwon: Employee; Hanmi Pharm. Co., Ltd. E.Park: Employee; Hanmi Pharm. Co., Ltd. J.Choi: Employee; Hanmi Pharm. Co., Ltd. S.Bae: None. D.Kim: None.