Promote Keratinocyte Proliferation Research Articles

Downregulation of Ebp1Khib210 promotes keratinocyte proliferation through induction of TIF-IA-mediated rRNA synthesis.

Psoriasis is a prevalent chronic inflammatory dermatosis characterized by excessive proliferation of keratinocytes. Protein lysine 2-hydroxyisobutyrylation (Khib) is a newly identified post-translational modification that regulates various biological processes. Abnormal Khib modification has been closely associated with the development of autoimmune diseases. To investigate the abnormal Khib profile and its pathogenic role in psoriasis. We utilized liquid chromatography-tandem mass spectrometry to analyze Khib-modified proteins in the epidermis of psoriasis and healthy controls. Mutated cells and mice with downregulated Ebp1Khib210 were generated to investigate its functional effects in psoriasis. The omic analysis revealed dysregulation of Khib modification in psoriatic lesions, exhibiting a distinct profile compared to controls. We observed the downregulation of Ebp1Khib210 in psoriatic lesions and IMQ-induced psoriatic mice. Notably, the expression of Ebp1Khib210 was upregulated in psoriatic patients following effective treatment. Decreased Ebp1Khib210 enhanced keratinocyte viability, proliferation, and survival while inhibiting apoptosis in vitro. Additionally, Pa2g4K210A mice with downregulated Ebp1Khib210 exhibited more severe psoriatic lesions and enhanced keratinocyte proliferation. Moreover, we found that Ebp1K210A mutation increased the interaction between Ebp1 and nuclear Akt, thereby inhibiting MDM2-mediated TIF-IA ubiquitination, and resulting to increased rRNA synthesis and keratinocyte proliferation. The downregulation of Ebp1Khib210 was attributed to inflammation-induced increases in HDAC2 expression. Our findings demonstrate that downregulation of Ebp1Khib210 promotes keratinocyte proliferation through modulation of Akt signaling and TIF-IA-mediated rRNA synthesis. These insights into Khib modification provide a better understanding of the pathogenesis of psoriasis and suggest potential therapeutic targets.

Upregulated miR-374a-5p drives psoriasis pathogenesis through WIF1 downregulation and Wnt5a/NF-κB activation

BackgroundPsoriasis is a chronic, inflammatory skin disease. MicroRNAs (miRNAs) are an abundant class of non-coding RNA molecules. Recent studies have shown that multiple miRNAs are abnormally expressed in patients with psoriasis. The upregulation of miR-374a-5p has been associated with psoriasis severity. However, the specific role of miR-374a-5p in the pathogenesis of psoriasis remain unclear. MethodsqRT-PCR was employed to validate the expression of miR-374a-5p in psoriatic lesions and in a psoriasis-like cell model constructed using a mixture of M5 (IL-17A, IL-22, OSM, IL-1α, and TNF-α). HaCaT cells were transfected with miR-374a-5p mimic/inhibitor, and assays including EdU, CCK-8, and flow cytometry were conducted to evaluate the effect of miR-374a-5p on cell proliferation. The expression of inflammatory cytokines IL-1β, IL-6, IL-8, and TNF-α was verified by qRT-PCR. Bioinformatics analysis and dual-luciferase reporter gene assay were performed to detect the downstream target genes and upstream transcription factors of miR-374a-5p, followed by validation of their expression through qRT-PCR and Western blotting. A psoriasis-like mouse model was established using imiquimod cream topical application. The psoriasis area and severity index scoring, hematoxylin-eosin histology staining, and Ki67 immunohistochemistry were employed to validate the effect of miR-374a-5p on the psoriatic inflammation phenotype after intradermal injection of miR-374a-5p agomir/NC. Additionally, the expression of pathway-related molecules and inflammatory factors such as IL-1β, IL-17a, and TNF-α was verified by immunohistochemistry. ResultsUpregulation of miR-374a-5p was observed in psoriatic lesions and the psoriasis-like cell model. In vitro experiments demonstrated that miR-374a-5p not only promoted the proliferation of HaCaT cells but also upregulated the expression of inflammatory cytokines, including IL-1β, IL-6, IL-8, and TNF-α. Furthermore, miR-374a-5p promoted skin inflammation and epidermal thickening in the Imiquimod-induced psoriasis-like mouse model. Mechanistic studies revealed that miR-374a-5p led to downregulation of WIF1, thereby activating the Wnt5a/NF-κB signaling pathway. The transcription factor p65 encoded by RELA, as a subunit of NF-κB, further upregulated the expression of miR-374a-5p upon activation. This positive feedback loop promoted keratinocyte proliferation and abnormal inflammation, thereby facilitating the development of psoriasis. ConclusionOur findings elucidate the role of miR-374a-5p upregulation in the pathogenesis of psoriasis through inhibition of WIF1 and activation of the Wnt5a/NF-κB pathway, providing new potential therapeutic targets for psoriasis.

IL-6 Up-Regulates Expression of LIM-Domain Only Protein 4 in Psoriatic Keratinocytes through Activation of the MEK/ERK/NF-κB Pathway

Psoriasis is a chronic inflammatory skin disease characterized by the activation of keratinocytes and the infiltration of immune cells. Overexpression of the transcription factor LIM-domain only protein 4 (LMO4) promoted by interleukin-23 (IL-23) has critical roles in regulating the proliferation and differentiation of psoriatic keratinocytes. IL-6, an autocrine cytokine in psoriatic epidermis, is a key mediator of IL-23/T helper (Th17)-driven cutaneous inflammation. However, little is known about how IL-6 regulates the upregulation of LMO4 expression in psoriatic lesions. In this study, human immortalized keratinocyte (HaCaT) cells, clinical biopsy specimens, and an animal model of psoriasis induced by imiquimod cream were used to investigate the role of IL-6 in the regulation of keratinocyte proliferation and differentiation. We found that IL-6 and LMO4 were abnormally expressed in the psoriatic epidermis. IL-6 up-regulates the expression of LMO4 and promotes keratinocyte proliferation and differentiation. Furthermore, in vitro and in vivo studies showed that IL-6 upregulates LMO4 expression by activating the MEK/ERK/NF-κB signaling pathway. These results suggest that IL-6 can activate the NF-κB signaling pathway, upregulate the expression of LMO4, lead to abnormal proliferation and differentiation of keratinocytes, and promote the occurrence and development of psoriasis.

NEK2 overexpression aggravates IL-22-induced keratinocyte proliferation and cytokine level increases and IMQ-induced psoriasis-like dermatitis.

Psoriasis is a common inflammatory skin disease characterized by the excessive proliferation and abnormal differentiation of keratinocytes. Protein kinases could act on intracellular signaling pathways associated with cell proliferation. Identifying more hub protein kinases affecting cellular and molecular processes in psoriasis, and exploring the dynamic effects of baicalin and NEK2 on the IL-22-induced cellular inflammation and IMQ-induced psoriasis-like mice. In this study, differentially expressed protein kinases playing a hub role in psoriasis initiation and development were identified using integrative bioinformatics analyses, and NEK2 has been chosen. NEK2 was significantly up-regulated in psoriatic samples according to online datasets and experimental analyses. In IL-22-induced cellular inflammation model in HaCaT cells, NEK2 overexpression promoted, whereas NEK2 knockdown partially abolished IL-22-induced alterations in cell viability, DNA synthesis, cytokine levels, as well as STAT3 phosphorylation and p-RB, cyclin D1, CDK4, and CDK6 protein contents. Baicalin treatment partially suppressed IL-22-induced HaCaT cell viability, DNA synthesis, and increases in cytokine levels, whereas NEK2 overexpression significantly abolished Baicalin-induced protection against cellular inflammation. In IMQ-induced psoriasis-like skin inflammation model in mice, baicalin markedly ameliorated IMQ-induced psoriasis-like symptoms and local skin inflammation, whereas NEK2 overexpression partially eliminated the therapeutic effects of baicalin. NEK2, up-regulated in psoriatic lesion skin, could aggravate IMQ-induced psoriasis-like dermatitis and attenuate the therapeutic efficiency of baicalin through promoting keratinocyte proliferation and cytokine levels. The STAT3 signaling might be involved.

Neutrophil-Derived MicroRNA-1290 Promotes Keratinocyte Proliferation in Psoriasis

The pathological hallmark of psoriasis is the infiltration of neutrophils into the skin. Some neutrophil-derived microRNAs (miRNAs) serve as biomarkers for various diseases, but none have been reported for psoriasis. In this study, we investigated the involvement of miRNAs released from neutrophils in psoriasis pathogenesis. We compared the expression of miRNAs in the sera of patients with psoriasis with that in healthy individuals and found that the expression of 2 miRNAs-miR-223 and miR-1290-was significantly upregulated in the sera of patients with psoriasis. The serum levels of these miRNAs positively correlated with the PASI and CRP levels. We used all-trans retinoic acid to induce the differentiation of human promyelocytic leukemia HL-60 cells into neutrophil-like cells and found that the release of both miRNAs increased during differentiation. Furthermore, the release of miR-1290 was increased by TNF-α in neutrophil-like cells and human neutrophils. Treatment with the miR-1290 precursor promoted the proliferation of human keratinocytes, increased the proportion of S-phase cells, and upregulated the phosphorylation of extracellular signal-regulated kinase 1/2. These results suggest that miR-1290 plays a vital role in regulating neutrophil differentiation and keratinocyte proliferation and could be a serum marker of psoriasis severity.

KRT17 from skin cells with high glucose stimulation promotes keratinocytes proliferation and migration.

Impaired diabetic wound healing is an important issue in diabetic complications. Proliferation and migration of keratinocytes are major processes of skin wound repair after injury. However, hyperkeratosis can affect the speed of wound healing. Based on the results of preliminary experiments on increased KRT17 expression after high glucose stimulation of human skin tissue cells, a cell model of human immortalized keratinocyte (HaCaT) stimulation with different concentrations of KRT17 was established in vitro, and the promotion in cell proliferation and migration were discovered. KRT17 silencing promoted diabetic wound healing in the db/db diabetic wound model. Transcriptome sequencing (RNA-seq) was performed on HaCaT cells after KRT17 stimulation, and analysis showed significant enrichment in the PI3K-AKT signaling pathway, in which the regulation of cell c-MYB mRNA, a key molecule regulating cell proliferation and migration, was significantly upregulated. In vitro assays showed increased c-MYB expression and enhanced pAKT activity after HaCaT cell stimulation by KRT17. We speculate that KRT17 is upregulated under high glucose and promotes keratinocyte proliferation and migration caused hyperkeratosis, through the c-MYB/PI3K-AKT pathway, contributing to delayed wound healing.

LncRNA H19 Inhibits Keratinocyte Cell Proliferation and Migration by Targeting miR-17-5p/RUNX1 Axis in Chronic Wounds.

The migration and proliferation of keratinocytes are critical for re-epithelization during chronic wound healing. Runt-related transcription factor 1 (RUNX1) has been indicated to repress keratinocyte proliferation. Nonetheless, the potential molecular mechanism of RUNX1 in regulating keratinocyte proliferation and migration remains unclear. Cell counting kit-8 and wound-healing assays were implemented for examining keratinocyte viability and migration, respectively. Western blotting and real-time quantitative polymerase chain reaction were utilized for quantifying protein and RNA levels. Luciferase reporter assay was employed for verifying the interaction between RUNX1, miR-17-5p, and long noncoding RNA H19. The results showed that RUNX1 depletion promoted keratinocyte proliferation and migration and repressed extracellular matrix degradation. Mechanistically, H19 upregulated RUNX1 expression by competitively absorbing miR-17-5p. Rescue experiments revealed that overexpressing RUNX1 reversed H19 silencing-mediated effects on the phenotypes of keratinocytes. In conclusion, H19 knockdown promotes keratinocyte proliferation and migration and suppresses extracellular matrix degradation via the miR-17-5p/RUNX1 axis.

A novel PPARβ/FFA1 dual agonist Y8 promotes diabetic wound healing

BackgroundDiabetes ulcer is one of the leading causes of disability and death in diabetics. Y8 [(2-(2-fluoro-4-((4-methyl-2-(4-(trifluoromethyl)phenyl)thiazol-5-yl)methoxy) phenoxy)acetic acid)], a dual agonist of peroxisome proliferation activated receptorβ (PPARβ) and free fatty acid receptor 1 (FFA1/FFAR1/GPR40), a new compound molecule with the potential for diabetes ulcer treatment. ObjectiveTo research the effect of the dual target agonist Y8 and its mechanism of action in the treatment of diabetic ulcers. MethodsWe have established a wound model in diabetic mice. After treatment with Y8, wound healing was evaluated by tissue pathology, reactive oxygen species (ROS) levels, and gene expression testing. Under high sugar conditions, the mechanism of Y8 affecting fibroblasts' proliferation and keratinocytes' migration is further studied. ResultsWe found that Y8 accelerated wound healing and shortened healing time in diabetic mice. Granulation tissue generation and extracellular matrix (ECM) deposition were significantly increased in Y8-treated mice. Mechanistically, Y8 promotes keratinocyte proliferation by activating PPARβ and migration of keratinocytes by triggering FFA1 in vitro. In addition, Y8 also decreased ROS levels in fibroblasts in vitro and in vivo by activating PPARβ, reducing their release of superoxide anions. ConclusionOur results suggest that PPARβ/FFA1 dual agonist Y8 has the effect of promoting the healing of diabetic ulcer wounds in vivo and in vitro, and its therapeutic effect is better than that of single-target agonists.

Wound healing effects of Asparagus lucidus Lindl extract through the phosphorylation of ERK1/2

BackgroundSkin is the outermost part of the human body and is essential in maintaining body homeostasis. In the event of skin injury, rapid wound repair is crucial to protect the body. In this study, we investigated the wound-healing properties of Asparagus lucidus Lindl extract by promoting keratinocyte proliferation.MethodsTo evaluate the effect of Asparagus lucidus Lindl extract on skin regeneration, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to measure keratinocyte proliferation, while an in vitro wound-healing assay was performed to evaluate wound closure through keratinocyte re-epithelialization. The intracellular mechanisms of the extract were studied using Western blot analysis to measure the phosphorylated forms of mitogen-activated protein kinases and protein kinase B. The mRNA expression of cell cycle-related genes was analyzed using quantitative real time-PCR analysis. A murine in vivo wound-healing assay was also conducted to observe the effect of the extract on wound closure.ResultsAsparagus lucidus Lindl extract induced 131.15% keratinocyte proliferation compared to the control in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The in vitro wound-healing assay showed that the extract improved wound closure by 216.94% through keratinocyte re-epithelialization. Western blot analysis revealed that the phosphorylated form of extracellular signal-regulated kinase 1/2 was increased by extract treatment. Quantitative real time-PCR analysis showed a dose-dependent increase in the mRNA expression of c-fos, c-jun, and VEGF. The in vivo wound-healing assay showed a significant increase (22.13%) of wound closure compared to the control on day 5.ConclusionAsparagus lucidus Lindl extract promotes keratinocyte proliferation by activating the extracellular signal-regulated kinase 1/2 pathway and up-regulating the mRNA expression of c-fos, c-jun, and vascular endothelial growth factor.

SLC35E1 promotes keratinocyte proliferation in psoriasis by regulating zinc homeostasis

Keratinocyte hyperproliferation is a key pathogenic factor in psoriasis. However, the mechanisms that regulate keratinocyte hyperproliferation in this condition remain unclear. Here, we found that SLC35E1 was highly expressed in keratinocytes of patients with psoriasis and that Slc35e1−/− mice displayed a less severe imiquimod (IMQ)-induced psoriasis-like phenotype than their wild-type siblings. In addition, SLC35E1 deficiency inhibited keratinocyte proliferation in both mice and cultured cells. On a molecular level, SLC35E1 was found to regulate zinc ion concentrations and subcellular localization, while zinc ion chelation reversed the IMQ-induced psoriatic phenotype in Slc35e1−/− mice. Meanwhile, epidermal zinc ion levels were decreased in patients with psoriasis and zinc ion supplementation alleviated the psoriatic phenotype in an IMQ-induced mouse model of psoriasis. Our results indicated that SLC35E1 can promote keratinocyte proliferation by regulating zinc ion homeostasis and zinc ion supplementation has potential as a therapy for psoriasis.

RIG-I contributes to keratinocyte proliferation and wound repair by inducing TIMP-1 expression through NF-κB signaling pathway.

Epithelial keratinocyte proliferation is an essential element of wound repair, and chronic wound conditions, such as diabetic foot, are characterized by aberrant re-epithelialization. In this study, we examined the functional role of retinoic acid inducible-gene I (RIG-I),a key regulator of epidermal keratinocyte proliferation, in promoting TIMP-1 expression. We found that RIG-Iis overexpressed in keratinocytes of skin injury and underexpressed in skin wound sites of diabetic foot and streptozotocin-induced diabetic mice. Moreover, mice lacking RIG-I developed an aggravated phenotype when subjected to skin injury. Mechanistically, RIG-I promoted keratinocyte proliferation and wound repair by inducing TIMP-1 via the NF-κB signaling pathway. Indeed, recombinant TIMP-1 directly accelerated HaCaT cell proliferation in vitro and promoted wound healing in Ddx58-/- and diabetic mice in vivo. In summary, we demonstrated that RIG-I is a crucial factor that mediates epidermal keratinocyte proliferation and may be a potential biomarker for skin injury severity, thus making it an attractive locally therapeutic target for the treatment of chronic wounds such as diabetic foot.

Study on the Key Genes and Molecular Mechanisms of IL-27 Promoting Keratinocytes Proliferation Based on Transcriptome Sequencing.

IL-27 involves psoriasis pathogenesis potentially by promoting excessive keratinocyte proliferation. However, the underlying mechanisms remain unclear. This study aims to explore the key genes and molecular mechanisms of IL-27-induced keratinocyte proliferation. Primary keratinocytes and immortalized human keratinocyte HaCaT cells were treated with different concentrations of IL-27 for 24 h and 48 h respectively. CCK-8 assay was used to detect cell viability and Western blot was used to detect the expression of CyclinE and CyclinB1. Primary keratinocytes and HaCaT cells were treated with IL-27, and their differentially expressed (DE) genes were obtained by transcriptome sequencing. Then Kyoto Encyclopedia of Genes and Genomes enrichment analysis was performed to predict related pathways, and the long non-coding RNA-microRNA-messenger RNA network and protein-protein interaction network were constructed to screen key genes. Biochemical experiments were performed to assess the content of glucose (Glu), lactic acid (LA), and ATP. Flow cytometry and Mito-Tracker Green staining were used to detect mitochondrial membrane potential and the number of mitochondria respectively. Western blot was performed to assess the expression of glucose transporter 1 (GLUT1), hexokinase 2 (HK2), lactate dehydrogenase A (LDHA), phosphoglycerate kinase 1 (PGK1), phosphorylated dynamin-related protein 1 (p-DRP1) (s637) and mitofusin 2 (MFN2). IL-27 concentration-dependently increased keratinocyte viability and the expression of CyclinE and CyclinB1. Bioinformatics analysis showed that the enriched pathways of DE genes were closely associated with cellular metabolism. miR-7-5p, EGFR, PRKCB, PLCB1 and CALM3 were key genes. IL-27 increased the content of LA, mitochondrial membrane potential, and the expression of GLUT1, HK2, LDHA, PGK1, p-DRP1 (s637), and MFN2, accompanied by decreased contents of Glu and ATP (P<0.001). IL-27 potentially promotes keratinocyte proliferation by enhancing glycolysis, mitochondrial function, and mitochondrial fusion. The findings of this study may be conducive to revealing the role of IL-27 in the pathogenesis of psoriasis.

Keratinocytes use FPR2 to detect Staphylococcus aureus and initiate antimicrobial skin defense.

Keratinocytes form a multilayer barrier that protects the skin from invaders or injuries. The barrier function of keratinocytes is in part mediated by the production of inflammatory modulators that promote immune responses and wound healing. Skin commensals and pathogens such as Staphylococcus aureus secrete high amounts of phenol-soluble modulin (PSM) peptides, agonists of formyl-peptide receptor 2 (FPR2). FPR2 is crucial for the recruitment of neutrophils to the sites of infection, and it can influence inflammation. FPR1 and FPR2 are also expressed by keratinocytes but the consequences of FPR activation in skin cells have remained unknown. Since an inflammatory environment influences S. aureus colonization, e. g. in patients with atopic dermatitis (AD), we hypothesized that interference with FPRs may alter keratinocyte-induced inflammation, proliferation, and bacterial colonization of the skin. To assess this hypothesis, we investigated the effects of FPR activation and inhibition in keratinocytes with respect to chemokine and cytokine release as well as proliferation and skin wound gap closure. We observed that FPR activation induces the release of IL-8, IL-1α and promotes keratinocyte proliferation in a FPR-dependent manner. To elucidate the consequence of FPR modulation on skin colonization, we used an AD-simulating S. aureus skin colonization mouse model using wild-type (WT) or Fpr2-/- mice and demonstrate that inflammation enhances the eradication of S. aureus from the skin in a FPR2-dependent way. Consistently, inhibition of FPR2 in the mouse model or in human keratinocytes as well as human skin explants promoted S. aureus colonization. Our data indicate that FPR2 ligands promote inflammation and keratinocyte proliferation in a FPR2-dependent manner, which is necessary for eliminating S. aureus during skin colonization.

Activation of Sestrin2 accelerates deep second-degree burn wound healing through PI3K/AKT pathway

Deep second-degree burns heal slowly, and promoting the healing process is a focus of clinical research. Sestrin2 is a stress-inducible protein with antioxidant and metabolic regulatory effects. However, its role during acute dermal and epidermal re-epithelialization in deep second-degree burns is unknown. In this study, we aimed to explore the role and molecular mechanism of sestrin2 in deep second-degree burns as a potential treatment target for burn wounds. To explore the effects of sestrin2 on burn wound healing, we established a deep second-degree burn mouse model. Then we detected the expression of sestrin2 by western blot and immunohistochemistry after obtaining the wound margin of full-thickness burned skin. The effects of sestrin2 on burn wound healing were explored in vivo and in vitro through interfering sestrin2 expression using siRNAs or the small molecule agonist of sestrin2, eupatilin. We also investigated the molecular mechanism of sestrin2 in promoting burn wound healing by western blot and CCK-8 assay. Our in vivo and in vitro deep second-degree burn wound healing model demonstrated that sestrin2 was promptly induced at murine skin wound edges. The small molecule agonist of sestrin2 accelerated the proliferation and migration of keratinocytes, as well as burn wound healing. Conversely, the healing of burn wounds was delayed in sestrin2-deficient mice and was accompanied by the secretion of inflammatory cytokines as well as the suppression of keratinocyte proliferation and migration. Mechanistically, sestrin2 promoted the phosphorylation of the PI3K/AKT pathway, and inhibition of PI3K/AKT pathway abrogated the promoting role of sestrin2 in keratinocyte proliferation and migration. Therefore, sestrin2 plays a critical role in activation of the PI3K/AKT pathway to promote keratinocyte proliferation and migration, as well as re-epithelialization in the process of deep second-degree burn wound repair.

Sp1-mediated miR-193b suppresses atopic dermatitis by regulating HMGB1.

Atopic dermatitis (AD) is a chronic and recurrent inflammatory skin disease. Keratinocyte dysfunction plays a central role in AD development. MicroRNA is a novel player in many inflammatory and immune skin diseases. In this study, we investigated the potential function and regulatory mechanism of miR-193b in AD. Inflamed human keratinocytes (HaCaT) were established by tumor necrosis factor (TNF)-α/interferon (IFN)-γ stimulation. Cell viability was measured using MTT assay, while the cell cycle was analyzed using flow cytometry. The cytokine levels were examined by enzyme-linked immunosorbent assay. The interaction between Sp1, miR-193b, and HMGB1 was analyzed using dual luciferase reporter and/or chromatin immunoprecipitation (ChIP) assays. Our results revealed that miR-193b upregulation enhanced the proliferation of TNF-α/IFN-γ-treated keratinocytes and repressed inflammatory injury. miR-193b negatively regulated high mobility group box 1 (HMGB1) expression by directly targeting HMGB1. Furthermore, HMGB1 knockdown promoted keratinocyte proliferation and inhibited inflammatory injury by repressing nuclear factor kappa-B (NF-κB) activation. During AD progression, HMGB1 overexpression abrogated increase of keratinocyte proliferation and repression of inflammatory injury caused by miR-193b overexpression. Moreover, transcription factor Sp1 was identified as the biological partner of the miR-193b promoter in promoting miR-193b expression. Therefore, Sp1 upregulation promotes keratinocyte proliferation and represses inflammatory injury during AD development via promoting miR-193b expression and repressing HMGB1/NF-κB activation.

Astragaloside IV promotes keratinocyte proliferation and migration through upregulating lncRNA H19 recruited ILF3 to enhance the stability of CDK4 mRNA.

Skin is the first line of the body to resist pathogen invasion. A potentially fatal infection may result from problems with wound healing. Small molecule drugs like astragaloside IV (AS-IV) show pro-healing activities, but the mechanisms are not fully understood. Using real-time quantitative PCR and a western blot assay, the amount of gene expression was evaluated. The proliferation and migration of keratinocytes were determined by MTS and wound healing assay, respectively. The binding of lncRNA H19 to RBP protein ILF3 and the binding of ILF3 protein to CDK4 mRNA were confirmed by RNA immunoprecipitation. Treatment with AS-IV enhanced the expression of lncRNA H19, ILF3, and CDK4 and improved the proliferation and migration of keratinocytes HaCaT. Additionally, apoptosis of keratinocytes was attenuated by AS-IV. Further studies showed that both lncRNA H19 and ILF3 were important for AS-IV-mediated keratinocyte growth and migration. In addition, lncRNA H19 recruited ILF3 to increase CDK4 mRNA level and enhanced cell proliferation. We discovered a lncRNA H19/ILF3/CDK4 axis that is activated by AS-IV to promote keratinocyte migration and proliferation. These results elucidate the mechanism of action of AS-IV and justify its application in further application in wound healing treatment.

Role of MR1-driven signals and amphiregulin on the recruitment and repair function of skin MAIT cells

Abstract Epithelial repair is crucial to reestablish adequate barrier integrity and function after tissue injury. In both mice and humans, MAIT (Mucosal associated invariant T) cells involvement in tissue repair is substantiated by their upregulation of tissue repair mediators following TCR-mediated activation. Additionally, in the absence of ɣδT cells, MAIT cells were shown to promote wound healing. By using both our congenic B6-MAIT CASTstrain (10× more MAIT cells than B6 mice) and a skin excision mouse model preventing epithelial contraction (mimicking the human repair process), we sought to uncover the underlying mechanisms of MAIT cell tissue repair function. Firstly, our scRNAseq analysis revealed that steady-state skin MAIT cells readily express a repair program. Additionally, we show that MAIT cells have a pro-repair function as their presence promotes keratinocyte proliferation, thereby accelerating healing. Using parabiosis, skin graft and the Kaede models, we found that, contrary to the resident ɣδT cells, MAIT cells are rapidly recruited into the inflamed skin. Parabiosis of MR1 +and MR1 −mice and MR1 −skin grafted onto MR1 +mice, showed that this recruitment was MR1-independent (MR1: antigen presenting molecule of MAIT cells). Instead, this recruitment relied on the chemokine receptor CXCR6 and its ligand CXCL16. Lastly, using conditional knock-out mice we demonstrated that the secretion by MAIT cells of the amphiregulin growth factor promotes skin wound healing. Overall, our study provides mechanistic insights into MAIT cell biology in the context of injury. Comprehension of these processes provides clues into the biology of related innate subsets and highlights potential new therapeutic avenues for wound healing. Institut National de la Santé et de la Recherche Médicale (OL) Institut Curie (OL) Agence Nationale de la Recherche Grant MAIT ANR-16-CE15-0020-01 (OL) Agence Nationale de la Recherche Grant MAITrepair ANR-20-CE15-0028-01 (OL) Agence Nationale de la Recherche ANR-10-IDEX-0001-02 PSL (OL) European Research Council (ERC-2019-AdG-885435) (OL) Fondation pour la Recherche Médicale, grant number FDT202106013036 (AdH)

829 Long non-coding RNA HSFY2-10:1 functions as a ceRNA to promote keratinocyte proliferation and psoriatic inflammation through the miR-145-5p/FN1 axis

829 Long non-coding RNA HSFY2-10:1 functions as a ceRNA to promote keratinocyte proliferation and psoriatic inflammation through the miR-145-5p/FN1 axis

Chemerin Exacerbates Psoriasis by Stimulating Keratinocyte Proliferation and Cytokine Production.

Psoriasis is often combined with metabolic abnormalities, such as obesity and diabetes. The upregulation of chemerin, which is an essential protein produced primarily from white fat, is strongly correlated to the development of psoriasis. However, there is no clarification on its exact function and mechanism in disease pathogenesis. The present study aims to determine its function and mechanism in disease pathogenesis. The present study used a psoriasislike inflammatory cell model and imiquimod (IMQ)-induced mouse model to confirm whether chemerin is upregulated in psoriasis patients. Chemerin enhanced the keratinocyte proliferation, inflammatory cytokine secretion, and activation of the MAPK signaling pathway. Crucially, the intraperitoneal injection of neutralizing anti-chemerin antibody (ChAb) diminished the epidermal proliferation and inflammation in the IMQ-induced mouse model. The present results indicate that chemerin promotes keratinocyte proliferation, and enhances the production of inflammatory cytokines, thereby aggravating the psoriasis. Thus, chemerin can be a prospective target for the treatment of psoriasis.

Long Non-Coding RNA-GDA-1 Promotes Keratinocyte Proliferation and Psoriasis Inflammation by Regulating the STAT3/NF-κB Signaling Pathwayvia Forkhead Box M1.

Psoriasis is a chronic inflammatory skin disease associated with multiple comorbidities and complex pathogenesis. Long non-coding RNAs (lncRNAs) play an important regulatory role in many diseases, including psoriasis. In this study, We aimed to investigate the role and mechanism of lncRNA GDA-1 (GDA) in M5-treated psoriatic keratinocytes. GDA expression was significantly upregulated in psoriatic tissues and M5-treated keratinocytes. By silencing and overexpressing GDA in NHEKs and Ker-CT cells, we showed that GDA regulated proliferation and cell cycle and increased secretion of interleukin-1β (IL-1β), IL-6, and chemokine ligands 2 and 20 (CCL2 and CCL20). RNA sequencing after GDA silencing led to the identification of a close regulatory relationship between GDA and Forkhead Box M1 (FOXM1). GDA significantly influenced FOXM1 expression at both mRNA and protein levels and activated STAT3/NF-κB signaling pathways. STAT3 and NF-κB inhibition abrogated GDA effects on keratinocyte proliferation and inflammation. In conclusion, our study is the first to report that Lnc-GDA-1 distinctly regulates FOXM1 expression and mediates proliferation and inflammation of psoriatic keratinocytes through the STAT3/NF-κB signaling pathway, which may be a potent target for psoriasis treatment.