ASC-J9 Blocks Cell Proliferation and Extracellular Matrix Production of Keloid Fibroblasts through Inhibiting STAT3 Signaling

Update on the Pathogenesis of Keloid Formation

Keloids are abnormal skin growths occurring in a significant portion of the global population. Despite their pervasiveness, the underlying pathophysiology of this scarring process is yet to be fully understood. In this review article, we delve into the current literature on the pathophysiological mechanisms of keloids. We take a top-down approach, first looking at host factors such as genetics and endocrine factors and then taking a more granular approach describing specific control factors such as germline keloid predisposition variants, epigenetics and transcriptomics, inflammatory and immune dysregulation, and the role of profibrotic and angiogenic cell signaling pathways. We then discuss current knowledge gaps, propose further research avenues, and explore potential future treatment options considering our increased understanding of keloid pathogenesis.

Comprehensive Insights into Keloid Pathogenesis and Advanced Therapeutic Strategies

Keloid scars, characterized by abnormal fibroproliferation and excessive extracellular matrix (ECM) production that extends beyond the original wound, often cause pruritus, pain, and hyperpigmentation, significantly impacting the quality of life. Keloid pathogenesis is multifactorial, involving genetic predisposition, immune response dysregulation, and aberrant wound-healing processes. Central molecular pathways such as TGF-β/Smad and JAK/STAT are important in keloid formation by sustaining fibroblast activation and ECM deposition. Conventional treatments, including surgical excision, radiation, laser therapies, and intralesional injections, yield variable success but are limited by high recurrence rates and potential adverse effects. Emerging therapies targeting specific immune pathways, small molecule inhibitors, RNA interference, and mesenchymal stem cells show promise in disrupting the underlying mechanisms of keloid pathogenesis, potentially offering more effective and lasting treatment outcomes. Despite advancements, further research is essential to fully elucidate the precise mechanisms of keloid formation and to develop targeted therapies. Ongoing clinical trials and research efforts are vital for translating these scientific insights into practical treatments that can markedly enhance the quality of life for individuals affected by keloid scars.

Insights into How Plant-Derived Extracts and Compounds Can Help in the Prevention and Treatment of Keloid Disease: Established and Emerging Therapeutic Targets

Keloid is a disease in which fibroblasts abnormally proliferate and synthesize excessive amounts of extracellular matrix, including collagen and fibronectin, during the healing process of skin wounds, causing larger scars that exceed the boundaries of the original wound. Currently, surgical excision, cryotherapy, radiation, laser treatment, photodynamic therapy, pressure therapy, silicone gel sheeting, and pharmacotherapy are used alone or in combinations to treat this disease, but the outcomes are usually unsatisfactory. The purpose of this review is to examine whether natural products can help treat keloid disease. I introduce well-established therapeutic targets for this disease and various other emerging therapeutic targets that have been proposed based on the phenotypic difference between keloid-derived fibroblasts (KFs) and normal epidermal fibroblasts (NFs). We then present recent studies on the biological effects of various plant-derived extracts and compounds on KFs and NFs. Associated ex vivo, in vivo, and clinical studies are also presented. Finally, we discuss the mechanisms of action of the plant-derived extracts and compounds, the pros and cons, and the future tasks for natural product-based therapy for keloid disease, as compared with existing other therapies. Extracts of Astragalus membranaceus, Salvia miltiorrhiza, Aneilema keisak, Galla Chinensis, Lycium chinense, Physalis angulate, Allium sepa, and Camellia sinensis appear to modulate cell proliferation, migration, and/or extracellular matrix (ECM) production in KFs, supporting their therapeutic potential. Various phenolic compounds, terpenoids, alkaloids, and other plant-derived compounds could modulate different cell signaling pathways associated with the pathogenesis of keloids. For now, many studies are limited to in vitro experiments; additional research and development are needed to proceed to clinical trials. Many emerging therapeutic targets could accelerate the discovery of plant-derived substances for the prevention and treatment of keloid disease. I hope that this review will bridge past, present, and future research on this subject and provide insight into new therapeutic targets and pharmaceuticals, aiming for effective keloid treatment.

Roles of the HIF-1α pathway in the development and progression of keloids

Keloids, a pathological scar that is induced by the consequence of aberrant wound healing, is still a major global health concern for its unsatisfactory treatment outcomes. HIF-1α, a main regulator of hypoxia, mainly acts through some proteins or signaling pathways and plays important roles in a variety of biological processes. Accumulating evidence has shown that HIF-1α played a crucial role in the process of keloid formation. In this review, we attempted to summarize the current knowledge on the association between HIF-1α expression and the development and progression of keloids. Through a comprehensive analysis, the molecular mechanisms underlying HIF-1α in keloids were shown to be correlated to the proliferation of fibroblasts, angiogenesis, and collagen deposits. The affected proteins and the signaling pathways were multiple. For instance, HIF-1α was reported to promote keloids formation by enhancing angiogenesis, fibroblast proliferation, and collagen deposition through the activation of periostin PI3K/Akt, TGF-β/Smad and TLR4/MyD88/NF-κB pathway. However, the specific effects of HIF-1α on keloids keloid illnesses in clinical practice is are entirely unclear, and further studies in clinical trials are still warranted. Therefore, an in-depth understanding of the biological mechanisms of HIF-1α in keloid formation is significant to develop promising therapeutic targets for the treatment of keloids in clinical practice.

The JAK-STAT pathway in keloid pathogenesis: a systematic review with qualitative synthesis

Keloid tissues contain inflammatory cells and upregulated pro-inflammatory cytokines. The Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway mediate cellular responses to these cytokines. We performed a systematic review on the role of the JAK-STAT pathway in keloid pathogenesis and the evidence for JAK-STAT inhibitors in keloid treatment. The search combined the terms (1) keloid and (2) JAK or TYK or STAT and included MeSH terms and synonyms. Two reviewers screened the articles and assessed the full texts on eligibility. Data were collected on the tested drugs and molecules, the type of cells and tissues used in the experiments, and study findings on the association between the JAK-STAT pathway and keloid cells and tissues. A total of twenty preclinical studies were included. Eleven preclinical studies proved that STAT3 expression and phosphorylation are enhanced in keloid tissue and keloid fibroblasts. Thirteen different JAK and/or STAT inhibitors were investigated. Tested drugs inhibited keloid progression as demonstrated by different processes, including reduced collagen production, cell proliferation and migration, increased cell cycle arrest and apoptosis, enhanced antioxidant responses, decreased (paracrine) signalling, and decreased profibrotic gene expression. No clinical studies have been published to date. Preclinical studies indicate a role for the JAK-STAT pathway in keloid pathogenesis and a potential role for JAK-STAT inhibitors in keloid treatment. The effect of these drugs should be further investigated on relevant biomarkers in a human keloid skin model, preferably including immune cells besides keloid fibroblasts and keratinocytes and in clinical studies.

An updated review of the immunological mechanisms of keloid scars

Keloid is a type of disfiguring pathological scarring unique to human skin. The disorder is characterized by excessive collagen deposition. Immune cell infiltration is a hallmark of both normal and pathological tissue repair. However, the immunopathological mechanisms of keloid remain unclear. Recent studies have uncovered the pivotal role of both innate and adaptive immunity in modulating the aberrant behavior of keloid fibroblasts. Several novel therapeutics attempting to restore regulation of the immune microenvironment have shown variable efficacy. We review the current understanding of keloid immunopathogenesis and highlight the potential roles of immune pathway-specific therapeutics.

LncRNA-ZNF252P-AS1/miR-15b-5p promotes the proliferation of keloid fibroblast by regulating the BTF3-STAT3 signaling pathway

BACKGROUND

JAK2/STAT3 signaling pathway plays an important role in keloid formation, but the upstream mechanism of their activation remains unclear.

OBJECTIVE

This study aims to investigate the possible mechanism of lncRNA-ZNF252P-AS1 in keloid.

METHODS

The differentially expressed genes in keloid and their upstream regulatory miRNAs and long non-coding RNAs (lncRNAs) were analyzed by bioinformatics database, and the targeting relationship was further verified by dual-luciferase reporter gene assay. LncRNA function as competitive endogenous RNA (ceRNA) in keloid was further verified by in keloid fibroblasts (KFs) and in nude mice with subcutaneous keloids.

RESULTS

BTF3 expression was up-regulated in keloid tissues. The targeting relationship between BTF3 and miR-15b-5p was confirmed by dual-luciferase reporter gene assay. miR-15b-5p overexpression inhibited BTF3, Bcl-2, Cyclin D1, C-myc, Collagen I, MMP2, MMP9, N-cadherin, and ZEB2 expressions in KFs, inhibited cell proliferation and migration, while promoted E-cadherin levels. BTF3 overexpression reversed miR-15b-5p effects on KFs. Bioinformatics analysis as well as clinical and cellular experiments confirmed that the lncRNA ZNF252P-AS1 was highly expressed in keloid/KFs. Dual-luciferase reporter gene assays confirmed the targeting relationship between lncRNA ZNF252P-AS1 and miR-15b-5p. LncRNA ZNF252P-AS1 overexpression inhibited miR-15b-5p and E-cadherin levels, upregulated BTF3, Bcl-2, Cyclin D1, C-myc, Collagen I, MMP2, MMP9, N-cadherin, and ZEB2 expressions, increased cell proliferation and migration, and activated JAK2/STAT3 pathway, while miR-15b-5p overexpression reversed this effect. The in vivo results were consistent with in vitro results. In vivo experiments further confirmed that lncRNA ZNF252P-AS1 reduced keloid volume and weight.

CONCLUSION

lncRNA ZNF252P-AS1 is a potential target for keloid treatment.