Excessive Collagen Research Articles

Targeting the Epigenetic Regulator CBX5 Promotes Fibroblast Metabolic Reprogramming and Inhibits Lung Fibrosis.

Idiopathic pulmonary fibrosis (IPF) is characterized by the sustained activation of interstitial fibroblasts leading to excessive collagen deposition and progressive organ failure. Epigenetic and metabolic abnormalities have been shown to contribute to the persistent activated state of scar-forming fibroblasts. However, how epigenetic changes regulate fibroblast metabolic responses to promote fibroblast activation and progressive fibrosis remains largely unknown. Here we show that the epigenetic regulator chromobox protein homolog 5 (CBX5) is critical to the transition of quiescent fibroblasts to activated collagen-producing fibroblasts in response to bleomycin induced lung injury. Loss of mesenchymal CBX5 attenuated fibrosis development, and this effect was accompanied by the downregulation of pathogenic fibroblast genes, including Cthrc1, Col1a1, and Spp1, and by the upregulation of metabolic genes with anti-fibrotic activity such as Ppara and Pparg. scRNA-seq and immunohistochemistry analyses revealed that CBX5 expression was enriched in pathogenic fibroblasts and fibroblastic foci of IPF lungs. Bulk RNA-seq analysis combined with metabolic assessments demonstrated that CBX5 silencing in IPF fibroblasts potently inhibited TGFβ-stimulated glycolysis while enhancing AMPK signaling and mitochondrial metabolism. Finally, interruption of the CBX5 pathway in IPF fibroblasts in vitro and in IPF lung explants ex vivo synergistically potentiated metformin-induced AMPK activation and inhibited collagen secretion. Collectively, our findings identify CBX5 as an epigenetic regulator linking metabolic maladaptation to the persistent activated state of lung fibroblasts during IPF progression.

The Relationship Between Preoperative Vitamin D Levels and Keloid Recurrence.

Keloids, characterized by excessive collagen deposition, often recur despite various treatments. This study explores the association between preoperative serum vitamin D levels and keloid recurrence in a Korean population. A retrospective cohort of 160 patients who underwent keloid excision was analyzed. Preoperative serum 25(OH) vitamin D and 1,25(OH)2 vitamin D levels were measured. Recurrence rates were compared using hierarchical logistic regression, adjusting for potential confounders. Age was significantly associated with keloid recurrence (OR: 0.934, p = 0.009), indicating older age was linked to lower recurrence risk. No significant association was found between preoperative 25(OH) vitamin D (p = 0.395) and 1,25(OH)2 vitamin D levels (p = 0.925) and keloid recurrence. Preoperative vitamin D levels do not predict keloid recurrence in this Korean cohort, while age is a significant predictor. Understanding the multifactorial nature of keloid pathogenesis requires further investigation into other potential risk factors.

Roles of MMP-2 and MMP-9 and their associated molecules in the pathogenesis of keloids: a comprehensive review.

Keloid scars (keloids), a prototypical form of aberrant scar tissue formation, continue to pose a significant therapeutic challenge within dermatology and plastic surgery due to suboptimal treatment outcomes. Gelatinases are a subgroup of matrix metalloproteinases (MMPs), a family of enzymes that play an important role in the degradation and remodeling of the ECM (a pivotal factor for keloids development). Gelatinases include gelatinase A (MMP-2) and gelatinase B (MMP-9). Since accumulating evidence has shown that gelatinases played a crucial role in the process of keloid formation, we summarized the current knowledge on the association between MMP-2 and MMP-9 expression and the pathological process of keloids through a comprehensive review. This review demonstrated that the interplay between MMP-2, MMP-9, and their regulators, such as TGF-β1/Smad, PI3K/AKT, and LncRNA-ZNF252P-AS1/miR-15b-5p/BTF3 signaling cascades, involved in the intricate balance governing ECM homeostasis, collectively driving the excessive collagen deposition and altered tissue architecture observed in keloids. In summary, this review consolidates the current understanding of MMP-2 and MMP-9 in keloid pathogenesis, shedding light on their intricate involvement in the dysregulated keloids processes. The potential for targeted therapeutic interventions presents promising opportunities for advancing keloid management strategies.

CD206+ macrophages are relevant non-invasive imaging biomarkers and therapeutic targets in experimental lung fibrosis

BackgroundInterstitial lung diseases (ILDs) include a large number of diseases associated with progressive pulmonary fibrosis (PPF), including idiopathic pulmonary fibrosis (IPF). Despite the rarity of each of the fibrotic ILDs...

Exploring Metabolic Mechanisms in Calcific Tendinopathy and Shoulder Arthrofibrosis: Insights and Therapeutic Implications.

Rotator cuff calcific tendinopathy and arthrofibrosis of the shoulder (adhesive capsulitis) are debilitating musculoskeletal disorders that significantly impact joint function and impair quality of life. Despite its high prevalence and common clinical presentation, the metabolic mechanisms underlying these conditions characterized by pain, and reduced mobility, remain poorly understood. This review aims to elucidate the role of metabolic processes implicated in the pathogenesis of calcific tendinopathy and shoulder arthrofibrosis. We will be focusing on the mechanistic role of how these processes contribute to disease progression and can direct potential therapeutic targets. Calcific tendinopathy is marked by aberrant calcium deposition within tendons, influenced by disrupted calcium and phosphate homeostasis, and altered cellular responses. Key molecular pathways, including bone morphogenetic proteins (BMPs), Wnt signaling, and transforming growth factor-beta (TGF-β), play crucial roles in the pathophysiology of calcification, calcium imbalance, and muscle fibrosis. In contrast, shoulder arthrofibrosis involves excessive collagen deposition and fibrosis within the shoulder joint capsule, driven by metabolic dysregulation and inflammation. The TGF-β signaling pathway and inflammatory cytokines, such as interleukin-6 (IL-6), are central to the fibrotic response. A comparative analysis reveals both shared and distinct metabolic pathways between these conditions, highlighting the interplay between inflammation, cellular metabolism, extracellular matrix remodeling, calcific deposition, and calcium migration to the glenohumeral joints, resulting in adhesive capsulitis, thereby providing insights into their pathophysiology. This review discusses current therapeutic approaches and their limitations, advocating for the development of targeted therapies that address specific metabolic dysregulations. Future therapeutic strategies focus on developing targeted interventions that address the underlying metabolic dysregulation, aiming to improve patient outcomes and advance clinical management. This review offers a comprehensive overview of the metabolic mechanisms involved in calcific tendinopathy and shoulder arthrofibrosis, providing a foundation for future research and therapeutic development.

Chemical Tools for Monitoring and Targeting Collagen Cross-linking.

The formation of collagen, the most abundant protein in mammals, is vital for the integrity of skin, tendons, and tissue in essentially any organ. Excessive collagen formation is, however, characteristic of fibrotic and malignant diseases, which include major global health issues. The diagnosis of abnormal collagen production and deposition is, therefore, critical for disease prognosis and helps guide treatment decisions. Here, we summarize our research on the development of tailored tools for monitoring and targeting excessive collagen crosslinking. We anticipate these tools will provide a deep understanding at the molecular level of collagen formation in normal and disease conditions with applications in imaging and disease treatment.

Ru single-atom nanozymes targeting ROS-ferroptosis pathways for enhanced endometrial regeneration in intrauterine adhesion therapy

Intrauterine adhesion (IUA) presents a significant challenge in gynecology, characterized by excessive fibrosis and compromised reproductive function, leading to severe infertility. Although biocompatible hydrogels integrated with stem cells offer a promising approach for IUA therapy, clinical applications remain limited. Recent studies have highlighted the role of ferroptosis and reactive oxygen species (ROS) in IUA pathogenesis, yet strategies targeting ferroptosis through antioxidant stress are underexplored. This study investigates the therapeutic effects and mechanisms of a Ru-Single-Atom Nanozyme (Ru-SAN) incorporated into chitosan hydrogel for treating IUA. Ru-SAN, which mimics the enzyme activities of catalase, superoxide dismutase, and glutathione peroxidase, effectively clears excess ROS and shows promise in treating oxidative stress-induced diseases. The results demonstrate the superior antioxidative capabilities of Ru-SAN, significantly suppressing the ROS-ferroptosis cycle at the injury site. This creates a favorable microenvironment for post-injury repair by inhibiting inflammation, enhancing mesenchymal-to-epithelial transformation, promoting angiogenesis, and polarizing M2 macrophages. Importantly, it mitigates adverse repair outcomes from inflammation and excessive collagen fiber deposition, ultimately restoring uterine glandular structures and thickness, thereby achieving the ultimate goal of restoring fertility and live birth rates. In conclusion, our study delineates a pioneering therapeutic approach leveraging the antioxidant properties of Ru-SAN to target ferroptosis, thereby offering an efficacious treatment for IUA.

Excessive collagen fiber deposition in idiopathic scrotal calcinosis: a case report

BackgroundIdiopathic scrotal calcinosis (ISC) is a manifestation of idiopathic calcinosis cutis, and its etiology is still unknown.Case presentationWe report a 36-year-old patient manifested multiple gradually increasing yellowish-white scrotal nodules with occasional itching and stinging in the past 6 years and was successfully cured via surgical excision. The laboratory test combined with pathological analysis confirmed the diagnosis of ISC. Like pathological calcinosis in other soft tissues, a large amount of collagen fiber deposition was observed around the calcification nodule, suggesting that abnormal collagen fiber deposition might be an important factor leading to idiopathic calcinosis in the scrotum. Moreover, koilocytes, which indicate human papillomavirus (HPV) infection, were also detected around calcified nodules, indicating the potential pathogenic role of HPV infection in ISC.ConclusionsHere, we report that ISC shows abnormal excessive deposition of collagen fibers around calcified nodules, which may be a vital factor contributing to the disease. Furthermore, combined with the literature review, a new pathogenic mechanism of ISC is proposed, and the site specificity of scrotal calcinosis is explained, providing a basis for further exploration of the pathogenic mechanism of ISC.

Efficacy of photodynamic therapy combined with cross-punch technique for the treatment of keloid

ObjectiveKeloids are characterized by abnormal activation of fibroblasts and excessive collagen deposition. Keloids are notoriously difficult to treat effectively due to their high recurrence rate after therapy. Our study explored the use of the punch technique in conjunction with photodynamic therapy, a novel approach that may swiftly reduce keloid volume, promote collagen remodeling, mitigate inflammation and enhance the wound healing process. MethodsIn our study, we conducted a retrospective analysis of 47 keloid patients who were treated with cross-punch technique combined with photodynamic therapy (punch+PDT group), compared them with a control group of 42 patients who received cross-punch therapy alone (punch group). The visual Analog Scale (VAS) scoring system, the Dermatology Life Quality Index (DLQI) questionnaire and the subjective scoring of patients were implemented to assess the improvement rate at baseline (month 0) and 12-month follow-up (month 12). ResultsThe results demonstrated significant enhancements in both VAS scores and DLQI scores on month 12 when compared with those on month 0. Notably, the subjective scoring indicated a marked difference, with 93.62 % of patients in the punch+PDT group and 59.52 % in the punch group reporting good or excellent improvement. ConclusionPatients in the punch+PDT group had a significant improvement rate than those in the punch group.

The Therapeutic Potential of Metformin for Attenuating Postsurgical Adhesion Band Formation

Objectives: Intra-abdominal adhesions are the most frequently occurring postoperative complication following abdominopelvic surgery. Peritoneal adhesion formation can lead to infertility, chronic pelvic pain, and intestinal obstruction. Several studies have shown the potential role of metformin in reducing inflammation. Here, we explored the therapeutic potency of Metformin against postsurgical adhesion band formation. Methods: We adopted Animal Research: Reporting of In Vivo Experiments (ARRIVE) guidelines for the experimental protocol. Peritoneal adhesions were examined macroscopically .Metformin (100 mg/kg) was administered intraperitoneally in male albino Wistar rats. After 9 days, macroscopic evidence and score of fibrotic bands based on scaling methods were performed and evaluated by the Nair and Leach scoring system. Moreover, the anti-inflammatory and antifibrosis effects were investigated by using hematoxylin and eosin, Masson's trichrome staining, the enzyme-linked immunosorbent assay (ELISA), and reverse transcription polymerase chain reaction (RT-PCR). Results: Metformin inhibited the stabilization of adhesion bands and appeared to elicit antiinflammatory responses by attenuating submucosal edema, suppressing proinflammatory cytokines, decreasing proinflammatory cell infiltration, and inhibiting oxidative stress at the site of peritoneal surgery. We also showed that metformin prevents fibrotic adhesion band formation by reducing excessive collagen deposition and suppression of profibrotic gene expression at the peritoneum adhesion tissues via modulation of Col 1A1/A3. Conclusion: These results supported the potential application of metformin in preventing postsurgical adhesion band formation by inhibiting key pathologic responses of inflammation and fibrosis in patients post-surgery.

Molecular Dissection of the Arsenic-Induced Leukocyte Incursion into the Inflamed Thymus and Spleen and Its Amelioration by Co-supplementation of L-Ascorbic Acid and α-Tocopherol.

Arsenic, a surreptitious presence in our environment, perpetuates a persistent global menace with its deleterious impacts. It possesses the capability to trigger substantial immunosuppression by instigating inflammation in critical organs like the thymus and spleen. L-Ascorbic acid (L-AA) exhibits robust immunoregulatory prowess by orchestrating the epigenetic terrain through TET and JHDM pathways. Conversely, α-tocopherol (α-T) demonstrates the capacity to dampen the production of pro-inflammatory cytokines by modulating the PI3K-Akt axis. Given these insights, this inquiry embarks on exploring the mitigative potential of L-AA and α-T co-supplementation at the transcriptome level within leukocytes under arsenic exposure. Concurrently, the research endeavours to unravel the potent anti-inflammatory effects of administering α-T and L-AA, alleviating inflammation within the spleen and thymus amidst arsenic-induced insult and delving deeply into their immunomodulatory mechanisms. The rats were randomly allocated into eight distinct groups for subsequent experimentation: (I) the control group was administered solely with distilled water as the vehicle (control); (II) NaAsO2-treated group (As); (III) NaAsO2 treated along with L-ascorbic acid and α-tocopherol supplemented group (As + L-AA + α-T); (IV) L-ascorbic acid and α-tocopherol supplemented group (L-AA + α-T); (V) NaAsO2 treated along with L-ascorbic acid supplemented group (As + L-AA); (VI) only L-ascorbic acid supplemented group (L-AA); (VII) NaAsO2 treated along with α-tocopherol supplemented group (As + α-T); (VIII) only α-tocopherol supplemented group (α-T). Rats treated with NaAsO2 exhibited an increased neutrophil count in their bloodstream, as revealed by a comprehensive transcriptomic analysis showcasing heightened expressions of ItgaM, MMP9, and Itga4 within circulating leukocytes under arsenic exposure. Concurrently, arsenic heightened the expression of pro-inflammatory cytokines within the thymus and spleen. This elevated cytokine activity promoted the upregulation of ICAM-1 on vascular endothelial cells, facilitating the infiltration of Ly6g + leukocytes into the afflicted thymus and spleen. Remarkably, the combination of L-AA acid and α-T demonstrated substantial therapeutic efficacy, adeptly reducing the influx of Ly6g + leukocytes into these immune sites and subsequent reduction of excessive collagen deposition. The dynamic duo of L-AA and α-T achieved this amelioration by suppressing the expression of ItgaM, MMP9, and Itga4 mRNA within circulating leukocytes and moderating tissue levels of pro-inflammatory cytokines in arsenic-exposed thymus and spleen.

Exploring the anti‑oxidative mechanisms of Rhodiola rosea in ameliorating myocardial fibrosis through network pharmacology and in vitro experiments.

Myocardial fibrosis (MF) significantly compromises cardiovascular health by affecting cardiac function through excessive collagen deposition. This impairs myocardial contraction and relaxation and leads to severe complications and increased mortality. The present study employed network pharmacology and in vitro assays to investigate the bioactive compounds of Rhodiola rosea and their targets. Using databases such as HERB, the Encyclopedia of Traditional Chinese Medicine, Pubchem, OMIM and GeneCards, the present study identified effective components and MF‑related targets. Network analysis was conducted with Cytoscape to develop a Drug‑Ingredient‑Target‑Disease network and the STRING database was utilized to construct a protein‑protein interaction network. Key nodes were analyzed for pathway enrichment using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes. Molecular interactions were further explored through molecular docking techniques. The bioactivity of salidroside (SAL), the principal component of Rhodiola rosea, against MF was experimentally validated in H9c2 cardiomyocytes treated with angiotensin II and assessed for cell viability, protein expression and oxidative stress markers. Network pharmacology identified 25 active ingredients and 372 targets in Rhodiola rosea, linking SAL with pathways such as MAPK, EGFR, advanced glycosylation end products‑advanced glycosylation end products receptor and Forkhead box O. SAL showed significant interactions with core targets such as albumin, IL6, AKT serine/threonine kinase 1, MMP9 and caspase‑3. In vitro, SAL mitigated AngII‑induced increases in collagen I and alpha smooth muscle actin protein levels and oxidative stress markers, demonstrating dose‑dependent effectiveness in reversing MF. SAL from Rhodiola rosea exhibited potent anti‑oxidative properties that mitigated MF by modulating multiple molecular targets and signaling pathways. The present study underscored the therapeutic potential of SAL in treating oxidative stress‑related cardiovascular diseases.

Oregano essential oil-infused mucin microneedle patch for the treatment of hypertrophic scar

Hypertrophic scar (HS) manifests as abnormal dermal myofibroblast proliferation and excessive collagen deposition, leading to raised scars and significant physical, psychological, and financial burdens for patients. HS is difficult to cure in the clinic and current therapies lead to recurrence, pain, and side effects. In this study, a natural amphiphilic polymer mucin is used to prepare a dissolving microneedle (muMN) that is loaded with oregano essential oil (OEO) for HS therapy. muMN exhibits sufficient skin/scar tissue penetration, quick skin recovery time after removal, good loading of natural essential oil, fast dissolution and detachment from the base layer, and good biocompatibility to applied skin. In the rabbit HS model, OEO@muMN shows a significant reduction in scar thickness, epidermal thickness index, and scar elevation index. OEO@muMN also attenuates the mean collagen area fraction and decreases the number of capillaries in scar tissues. Biochemical Assay reveals that OEO@muMN significantly inhibits the expression of transforming growth factor-β1 (TGF-β1) and hydroxyproline (HYP). In summary, this study demonstrates the feasibility and good efficacy of using the anti-proliferative and anti-oxidative OEO for HS treatment. OEO@muMN is an efficient formulation that holds the potential for clinical anti-HS application. muMN is an efficient platform to load and apply essential oils transdermally.

Immunoregulation of Liver Fibrosis: New Opportunities for Antifibrotic Therapy.

Liver fibrosis develops in response to chronic liver injury and is characterized by a sustained inflammatory response that leads to excessive collagen deposition by myofibroblasts. The fibrogenic response is governed by the release of inflammatory mediators from innate, adaptive, and innate-like lymphoid cells and from nonprofessional immune cells (i.e., epithelial cells, hepatic myofibroblasts, and liver sinusoidal endothelial cells). Upon removal of the underlying cause, liver fibrosis can resolve via activation of specific immune cell subsets. Despite major advances in the understanding of fibrosis pathogenesis, there is still no approved antifibrotic therapy. This review summarizes our current knowledge of the immune cell landscape and the inflammatory mechanisms underlying liver fibrosis progression and regression. We discuss how reprogramming immune cell phenotype, in particular through targeting selective inflammatory pathways or modulating cell-intrinsic metabolism, may be translated into antifibrogenic therapies.

Identifying new molecular signatures and potential therapeutics for idiopathic pulmonary fibrosis: a network medicine approach.

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal lung disease characterized by excessive collagen deposition and fibrosis of the lung parenchyma, leading to respiratory failure. The molecular mechanisms underlying IPF pathogenesis remain incompletely understood, hindering the development of effective therapeutic strategies. We have used a network medicine approach to comprehensively analyze molecular interactions and identify novel molecular signatures and potential therapeutics associated with IPF progression. Our integrative analysis revealed dysregulated molecular networks that are central to IPF pathophysiology. We have highlighted key molecular players and signaling pathways that are implicated in aberrant fibrotic processes. This systems-level understanding enables the identification of new biomarkers and therapeutic targets for IPF, providing potential avenues for precision medicine. Drug repurposing analysis revealed several drug candidates with anti-fibrotic, anti-inflammatory, and anti-cancer activities that could potentially slow fibrotic progression and improve patient outcomes. This study offers new insights into the molecular underpinnings of IPF and highlights network medicine approaches in uncovering complex disease mechanisms. The molecular signatures and therapeutic targets identified hold promise for developing precision therapies tailored to individual patients, ultimately advancing the management of this debilitating lung disease.

The Effects of Mesenchymal Stem Cells-Derived Exosomes on Metabolic Reprogramming in Scar Formation and Wound Healing.

Pathological scarring results from aberrant cutaneous wound healing due to the overactivation of biological behaviors of human skin fibroblasts, characterized by local inordinate inflammation, excessive extracellular matrix and collagen deposition. Yet, its underlying pathogenesis opinions vary, which could be caused by increased local mechanical tension, enhanced and continuous inflammation, gene mutation, as well as cellular metabolic disorder, etc. Metabolic reprogramming is the process by which the metabolic pattern of cells undergoes a systematic adjustment and transformation to adapt to the changes of the external environment and meet the needs of their growth and differentiation. Therefore, the abnormality of metabolic reprogramming in cells within wounds and scars attaches great importance to scar formation. Mesenchymal stem cells-derived exosomes (MSC-Exo) are the extracellular vesicles that play an important role in tissue repair, cancer treatment as well as immune and metabolic regulation. However, there is not a systematic work to detail the relevant studies. Herein, we gave a comprehensive summary of the existing research on three main metabolisms, including glycometabolism, lipid metabolism and amino acid metabolism, and MSC-Exo regulating metabolic reprogramming in wound healing and scar formation for further research reference.

Wound care used topical ointment made from a combination of cherry leaf extract (Muntingia calabura L) and manuka honey on the healing process of superficial second-degree burns: a case report

Background: Burns are one of the most common accidental injuries in the community. Improper treatment of burns can lead to disability and even death. Applying topical therapy aims to reduce excessive collagen repositioning and accelerate healing. We tried treating burn wounds with an ointment that uses a combination of cherry leaf extract and manuka honey to test the effectiveness of wound healing.Case presentation: We report two cases of superficial burns that underwent wound treatment using an ointment containing cherry leaf extract and manuka honey.Conclusion: Wound treatment with an ointment containing cherry leaf extract and manuka honey can speed up the healing process in patients with superficial second-degree burns.

Gene inactivation of lysyl oxidase in smooth muscle cells reduces atherosclerosis burden and plaque calcification in hyperlipidemic mice

Background and aimsLysyl oxidase (LOX) catalyzes the crosslinking of collagen and elastin to maintain tensile strength and structural integrity of the vasculature. Excessive LOX activity increases vascular stiffness and the severity of occlusive diseases. Herein, we investigated the mechanisms by which LOX controls atherogenesis and osteogenic differentiation of vascular smooth muscle cells (SMC) in hyperlipidemic mice. MethodsGene inactivation of Lox in SMC was achieved in conditional knockout mice after tamoxifen injections. Atherosclerosis burden and vascular calcification were assessed in hyperlipidemic conditional [Loxf/fMyh11-CreERT2ApoE−/−] and sibling control mice [Loxwt/wtMyh11-CreERT2ApoE−/−]. Mechanistic studies were performed with primary aortic SMC from Lox mutant and wild type mice. ResultsInactivation of Lox in SMCs decreased > 70 % its RNA expression and protein level in the aortic wall and significantly reduced LOX activity without compromising vascular structure and function. Moreover, LOX deficiency protected mice against atherosclerotic burden (13 ± 2 versus 23 ± 1 %, p < 0.01) and plaque calcification (5 ± 0.4 versus 11.8 ± 3 %, p < 0.05) compared to sibling controls. Interestingly, gene inactivation of Lox in SMCs preserved the contractile phenotype of vascular SMC under hyperlipidemic conditions as demonstrated by single-cell RNA sequencing and immunofluorescence. Mechanistically, the absence of LOX in SMC prevented excessive collagen crosslinking and the subsequent activation of the pro-osteogenic FAK/β-catenin signaling axis. ConclusionsLox inactivation in SMC protects mice against atherosclerosis and plaque calcification by reducing SMC modulation and FAK/β-catenin signaling.

Conditional deletion of CEACAM1 in hepatic stellate cells causes their activation

ObjectivesHepatic CEACAM1 expression declines with advanced hepatic fibrosis stage in patients with metabolic dysfunction-associated steatohepatitis (MASH). Global and hepatocyte-specific deletions of Ceacam1 impair insulin clearance to cause hepatic insulin resistance and steatosis. They also cause hepatic inflammation and fibrosis, a condition characterized by excessive collagen production from activated hepatic stellate cells (HSCs). Given the positive effect of PPARγ on CEACAM1 transcription and on HSCs quiescence, the current studies investigated whether CEACAM1 loss from HSCs causes their activation. MethodsWe examined whether lentiviral shRNA-mediated CEACAM1 donwregulation (KD-LX2) activates cultured human LX2 stellate cells. We also generated LratCre + Cc1fl/fl mutants with conditional Ceacam1 deletion in HSCs and characterized their MASH phenotype. Media transfer experiments were employed to examine whether media from mutant human and murine HSCs activate their wild-type counterparts. ResultsLratCre + Cc1fl/fl mutants displayed hepatic inflammation and fibrosis but without insulin resistance or hepatic steatosis. Their HSCs, like KD-LX2 cells, underwent myofibroblastic transformation and their media activated wild-type HSCs. This was inhibited by nicotinic acid treatment which blunted the release of IL-6 and fatty acids, both of which activate the epidermal growth factor receptor (EGFR) tyrosine kinase. Gefitinib inhibition of EGFR and its downstream NF-κB/IL-6/STAT3 inflammatory and MAPK-proliferation pathways also blunted HSCs activation in the absence of CEACAM1. ConclusionsLoss of CEACAM1 in HSCs provoked their myofibroblastic transformation in the absence of insulin resistance and hepatic steatosis. This response is mediated by autocrine HSCs activation of the EGFR pathway that amplifies inflammation and proliferation.

Abstract We108: Adipocyte Enhancer Binding Protein 1 (AEBP1) Inhibition as a Potential Anti-Fibrotic Therapy in Heart Failure

Introduction: Cardiac fibrosis is one of the major hallmarks of heart failure (HF) progression. Fibrosis is initiated as a repair mechanism following any kind of cardiac injury including a heart attack, inflammation, hypertension, etc. Briefly, fibroblasts are activated to form myofibroblasts that secrete collagen. Persistent fibroblast activation leads to excess collagen deposition leading to tissue stiffening and impaired contractility and thereby HF. To date, there is no anti-fibrotic therapy used in HF patients. Using bulk and snRNA sequencing data performed on myocardial tissue from HF patients, we identified adipocyte enhancer binding protein (AEBP1) to be significantly upregulated in activated fibroblasts. AEBP1 has been shown to play a crucial role in fibroblast activation following injury in the kidney, liver, and lungs. AEBP1 inhibition resulted in fibrosis attenuation in these organs. However, its role in cardiac fibrosis is not well understood. Hypothesis: We hypothesize that AEBP1 is crucial for cardiac fibroblast activation and AEBP1 inhibition will prevent collagen secretion and lead to improved cardiac function. Methods: Human cardiac fibroblasts (HCF) from non-failing donors were used for in vitro experiments. AdV-CMV-AEBP1 was used for AEBP1 overexpression (OE) and AdV-CMV-shAEBP1 was used to knockdown (KD) AEBP1 in vitro. AAV9-CMV-shAEBP1 was used for in vivo KD of AEBP1 in mice following myocardial infarction (MI). Human myocardial slices from n=6 HF patients were used and AdV-CMV-shAEBP1 was used to knockdown AEBP1 in human samples. Results and Discussion: AEBP1 OE in HCF resulted in fibroblast activation and collagen secretion (n=6, p=0.002). Contrarily, loss of AEBP1 significantly prevented fibroblast activation, evident from a reduction in transgelin (SM22) (n=6, p=0.02) and collagen (COL1A1) protein levels (n=6, p=0.01). AEBP1 KD in a mouse model of acute cardiac fibrosis resulted in reduced fibrosis and improved cardiac function (n=6, 12% absolute improvement compared to untreated mice, relative improvement in ejection fraction, p=0.02). Tissue culture studies of human HF myocardium showed a significant improvement in cardiac structure evident from reduced cardiomyocyte hypertrophy (n=6 HF patients, p=0.05) and reduced fibrosis (n=6, p&lt;0.0001) following AEBP1 KD. Overall, we show that AEBP1 plays a critical role in fibrogenesis, and its inhibition has the potential to attenuate fibrosis in acute and chronic HF.