Hypertrophic Scar Fibroblasts Research Articles

Blocking the MIR155HG/miR-155 axis reduces CTGF-induced inflammatory cytokine production and α-SMA expression via upregulating AZGP1 in hypertrophic scar fibroblasts

Hypertrophic scarring (HS) is a pathological condition characterized by excessive fibrosis and inflammation, resulting in excessive extracellular matrix formation in the skin. MIR155HG, a long non-coding RNA, is abnormally upregulated in fibrotic tissues; however, its underlying mechanism is poorly understood. Using single-cell sequencing data, we analyzed connective tissue growth factor (CTGF) expression in various cell types in HS and normal skin tissues and MIR155HG expression in clinical samples. To investigate the mechanism of fibrosis, an in vitro model using CTGF-treated hypertrophic scar fibroblasts (HSFBs) was established and qRT-PCR, western blotting and ELISA assays were performed to investigate the expression of interleukin (IL)-1β, IL-6, and mesenchymal markers α-smooth muscle actin (α-SMA). CTGF stimulates MIR155HG level through phosphorylated STAT3 binding to the MIR155HG promoter. We analyzed the methylation of MIR155HG, assessed the levels of miR-155-5p/−3p in CTGF-treated HSFBs and identified differentially expressed genes among HS and NS samples using the Gene Expression Omnibus RNA sequencing data. The binding between miR-155-5p/−3p and AZGP1 was confirmed using a dual-luciferase assay and inflammatory cytokine production and α-SMA expression were investigated in rescue experiments. The findings revealed that CTGF elevated inflammatory cytokine production, α-SMA and MIR155HG expression in HSFBs. MIR155HG is upregulated in HS tissues due to low DNA methylation. Mechanistically, miR-155-5p/−3p was directly bound to MIR155HG 3’UTR. MIR155HG silencing inhibited cytokine production and α-SMA expression by repressing the generation of miR-155-5p/−3p in CTGF-treated HSFBs. Bioinformatics analysis and luciferase reporter assays revealed that miR-155-5p/−3p targets AZGP1. In addition, transfection with plasmids carrying AZGP1 cDNA significantly inhibited the signaling activity of miR-155-5p/−3 p-overexpressing HSFBs. Our findings highlight the importance of the MIR155HG/miR-155/AZGP1 axis in regulating cytokine production and α-SMA in HS.

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CILP2 promotes hypertrophic scar through Snail acetylation by interaction with ACLY

Background & aimsHypertrophic scar (HS) is a skin fibroproliferative disorder occurring after burns, surgeries or traumatic injuries, and it has caused a tremendous economic and medical burden. Its molecular mechanism is associated with the abnormal proliferation and transition of fibroblasts and excessive deposition of extracellular matrix. Cartilage intermediate layer protein 2 (CILP2), highly homologous to cartilage intermediate layer protein 1 (CILP1), is mainly secreted predominantly from chondrocytes in the middle/deeper layers of articular cartilage. Recent reports indicate that CILP2 is involved in the development of fibrotic diseases. We investigated the role of CILP2 in the progression of HS. Methods and resultsIt was found in this study that CILP2 expression was significantly higher in HS than in normal skin, especially in myofibroblasts. In a clinical cohort, we discovered that CILP2 was more abundant in the serum of patients with HS, especially in the early stage of HS. In vitro studies indicated that knockdown of CILP2 suppressed proliferation, migration, myofibroblast activation and collagen synthesis of hypertrophic scar fibroblasts (HSFs). Further, we revealed that CILP2 interacts with ATP citrate lyase (ACLY), in which CILP2 stabilizes the expression of ACLY by reducing the ubiquitination of ACLY, therefore prompting Snail acetylation and avoiding reduced expression of Snail. In vivo studies indicated that knockdown of CILP2 or ACLY inhibitor, SB-204990, significantly alleviated HS formation. ConclusionCILP2 exerts a vital role in hypertrophic scar formation and might be a detectable biomarker reflecting the progression of hypertrophic scar and a therapeutic target for hypertrophic scar.

Lariciresinol Induces Apoptosis and Inhibits Migration-Invasion of Patient-Derived Hypertrophic Scar Fibroblasts via Preventing Accumulation of Collagen

Lariciresinol Induces Apoptosis and Inhibits Migration-Invasion of Patient-Derived Hypertrophic Scar Fibroblasts via Preventing Accumulation of Collagen

Influences and mechanism of extracellular vesicles from dermal papilla cells of mice on human hypertrophic scar fibroblasts

Objective: To investigate the influences and mechanism of extracellular vesicles from dermal papilla cells (DPC-EVs) of mice on human hypertrophic scar fibroblasts (HSFs). Methods: The study was an experimental research. The primary dermal papilla cells (DPCs) of whiskers were extracted from 10 6-week-old male C57BL/6J mice and identified successfully. The DPC-EVs were extracted from the 3rd to 5th passage DPCs by ultracentrifugation, and the morphology was observed through transmission electron microscope and the particle diameter was detected by nanoparticle tracking analyzer (n=3) at 24 h after culture. The 3rd passage of HSFs were divided into DPC-EV group and phosphate buffer solution (PBS) group, which were cultured with DPC-EVs and PBS, respectively. The cell scratch test was performed and cell migration rate at 24 h after scratching was calculated (n=5). The cell proliferation levels at 0 (after 12 h of starvation treatment and before adding DPC-EVs or PBS), 24, 48, 72, and 96 h after culture were detected by using cell counting kit 8 (n=4). The protein expressions of α-smooth muscle actin (α-SMA) and collagen typeⅠ (ColⅠ) in cells at 24 h after culture were detected by immunofluorescence method and Western blotting, and the protein expression of Krüppel-like factor 4 (KLF4) in cells at 24 h after culture was detected by Western blotting. After the 3rd passage of HSFs were cultured with DPC-EVs for 24 h, the cells were divided into blank control group, KLF4 knockdown group, and KLF4 overexpression group according to the random number table. The cells in blank control group were only routinely cultured for 48 h. The cells in KLF4 knockdown group and KLF4 overexpression group were incubated with KLF4 knockdown virus for 24 h, then the cells in KLF4 knockdown group were routinely cultured for 24 h while the cells in KLF4 overexpression group were incubated with KLF4 overexpression virus for 24 h. The protein expressions of KLF4, α-SMA, and ColⅠ in cells were detected by Western blotting at 48 h after culture. Results: At 24 h after culture, the extracted DPC-EVs showed vesicular structure with an average particle diameter of 108.8 nm. At 24 h after scratching, the migration rate of HSFs in PBS group was (54±10)%, which was significantly higher than (29±8)% in DPC-EV group (t=4.37, P<0.05). At 48, 72, and 96 h after culture, the proliferation levels of HSFs in DPC-EV group were significantly lower than those in PBS group (with t values of 4.06, 5.76, and 6.41, respectively, P<0.05). At 24 h after culture, the protein expressions of α-SMA and ColⅠ of HSFs in DPC-EV group were significantly lower than those in PBS group, while the protein expression of KLF4 was significantly higher than that in PBS group. At 48 h after culture, compared with those in blank control group, the protein expression of KLF4 of HSFs in KLF4 knockdown group was down-regulated, while the protein expressions of α-SMA and ColⅠ were both up-regulated; compared with those in KLF4 knockdown group, the protein expression of KLF4 of HSFs in KLF4 overexpression group was up-regulated, while the protein expressions of ColⅠ and α-SMA were down-regulated. Conclusions: The DPC-EVs of mice can inhibit the proliferation and migration of human HSFs and significantly inhibit the expressions of fibrosis markers α-SMA and ColⅠ in human HSFs by activating KLF4.

Differential Photosensitivity of Fibroblasts Obtained from Normal Skin and Hypertrophic Scar Tissues.

It is unclear whether normal human skin tissue or abnormal scarring are photoreceptive. Therefore, this study investigated photosensitivity in normal skin tissue and hypertrophic scars. The expression of opsins, which are photoreceptor proteins, in normal dermal fibroblasts (NDFs) and hypertrophic scar fibroblasts (HSFs) was examined. After exposure to blue light (BL), changes in the expression levels of αSMA and clock-related genes, specifically PER2 and BMAL1, were examined in both fibroblast types. Opsins were expressed in both fibroblast types, with OPN3 exhibiting the highest expression levels. After peripheral circadian rhythm disruption, BL induced rhythm formation in NDFs. In contrast, although HSFs showed changes in clock-related gene expression levels, no distinct rhythm formation was observed. The expression level of αSMA was significantly higher in HSFs and decreased to the same level as that in NDFs upon BL exposure. When OPN3 knocked-down HSFs were exposed to BL, the reduction in αSMA expression was inhibited. This study showed that BL exposure directly triggers peripheral circadian synchronization in NDFs but not in HSFs. OPN3-mediated BL exposure inhibited HSFs. Although the current results did not elucidate the relationship between peripheral circadian rhythms and hypertrophic scars, they show that BL can be applied for the prevention and treatment of hypertrophic scars and keloids.

PTEN hinders the formation of scars by regulating the levels of proteins in the extracellular matrix and promoting the apoptosis of dermal fibroblasts through Bcl-xL

Hypertrophic scar (HS) is a dermatological condition characterized by an excessive accumulation of proteins in the extracellular matrix (ECM) and an elevated cell count. The development of HS is thought to be linked to the disruption of dermal fibroblast proliferation and apoptosis. The processes of cell proliferation and apoptosis are notably influenced by PTEN. However, the precise mechanisms by which PTEN regulates hypertrophic scar fibroblasts (HSFs) and its overall role in scar formation are still not fully understood. The objective of this study was to investigate the influence of PTEN on hypertrophic scars(HS) and its function in the regulation of scar formation, with the aim of identifying a pivotal molecular target for scar treatment. Our results demonstrate that the overexpression of PTEN (AdPTEN) significantly suppressed the expression of type I collagen (Col I), type III collagen (Col III), and alpha smooth muscle actin (α-SMA) in HSFs. Furthermore, it was observed that the introduction of AdPTEN resulted in the suppression of Bcl-xL expression, which consequently led to an increase in the apoptosis of HSFs. Similarly, in the inhibition of collagens expression and subsequent increase in HSF apoptosis were also observed upon silencing Bcl-xL (sibcl-xL). Additionally, the in vitro model demonstrated that both AdPTEN and sibcl-xL were effective in reducing the contraction of FPCL. The findings of our study provide validation for the role of PTEN in inhibiting the development of hypertrophic scars (HS) by modulating the expression of extracellular matrix (ECM) proteins and promoting apoptosis in hypertrophic scar fibroblasts (HSFs) via Bcl-xL. These results indicate that PTEN and Bcl-xL may hold promise as potential molecular targets for therapeutic interventions aimed at managing hypertrophic scars.

TEM1/endosialin/CD248 promotes pathologic scarring and TGF-β activity through its receptor stability in dermal fibroblasts

BackgroundPathologic scars, including keloids and hypertrophic scars, represent a common form of exaggerated cutaneous scarring that is difficult to prevent or treat effectively. Additionally, the pathobiology of pathologic scars remains poorly understood. We aim at investigating the impact of TEM1 (also known as endosialin or CD248), which is a glycosylated type I transmembrane protein, on development of pathologic scars.MethodsTo investigate the expression of TEM1, we utilized immunofluorescence staining, Western blotting, and single-cell RNA-sequencing (scRNA-seq) techniques. We conducted in vitro cell culture experiments and an in vivo stretch-induced scar mouse model to study the involvement of TEM1 in TGF-β-mediated responses in pathologic scars.ResultsThe levels of the protein TEM1 are elevated in both hypertrophic scars and keloids in comparison to normal skin. A re-analysis of scRNA-seq datasets reveals that a major profibrotic subpopulation of keloid and hypertrophic scar fibroblasts greatly expresses TEM1, with expression increasing during fibroblast activation. TEM1 promotes activation, proliferation, and ECM production in human dermal fibroblasts by enhancing TGF-β1 signaling through binding with and stabilizing TGF-β receptors. Global deletion of Tem1 markedly reduces the amount of ECM synthesis and inflammation in a scar in a mouse model of stretch-induced pathologic scarring. The intralesional administration of ontuxizumab, a humanized IgG monoclonal antibody targeting TEM1, significantly decreased both the size and collagen density of keloids.ConclusionsOur data indicate that TEM1 plays a role in pathologic scarring, with its synergistic effect on the TGF-β signaling contributing to dermal fibroblast activation. Targeting TEM1 may represent a novel therapeutic approach in reducing the morbidity of pathologic scars.

The effects of TGF-β1 and IFN-α2b on decorin, decorin isoforms and type I collagen in hypertrophic scar dermal fibroblasts.

Hypertrophic scars (HTS) develop from an excessive synthesis of structural proteins like collagen and a decreased expression of proteoglycans such as decorin. Previous research has demonstrated that decorin expression is significantly down-regulated in HTS, deep dermal tissue, and thermally injured tissue, reducing its ability to regulate pro-fibrotic transforming growth factor-beta 1 (TGF-β1) and normal fibrillogenesis. However, treatment of HTS fibroblasts with interferon-alpha 2b (IFN-α2b) has been shown to reduce excessive collagen synthesis and improve HTS by reducing serum TGF-β1 levels. The expression of decorin isoforms in HTS is currently unknown and the effects of TGF-β1 and IFN-α2b on decorin, decorin isoform expression and type 1 collagen are of great interest to our group. Dermal fibroblasts were treated with TGF-β1 and/or IFN-α2b, for 48 h. The expression and secretion of decorin, decorin isoforms and type 1 collagen were quantified with reverse transcription-quantitative polymerase chain reaction, immunofluorescence staining and enzyme-linked immunosorbent assays. The mRNA expression of decorin and each isoform was significantly reduced in HTS fibroblasts relative to normal skin. TGF-β1 decreased the mRNA expression of decorin and decorin isoforms, whereas IFN-α2b showed the opposite effect. IFN-α2b significantly inhibited TGF-β1's effect on the mRNA expression of type I collagen alpha 1 in papillary dermal fibroblasts and overall showed relative effects of inhibiting TGF-β1. These data support that a further investigation into the structural and functional roles of decorin isoforms in HTS pathogenesis is warranted and that IFN-α2b is an important agent in reducing fibrotic outcomes.

CLC-3 regulates TGF-β/smad signaling pathway to inhibit the process of fibrosis in hypertrophic scar

ObjectiveTo study the role and mechanism of chloride channel-3 (ClC-3) in the formation of hypertrophic scar by constructing ClC-3 interference vectors and examining their effects on human hypertrophic scar fibroblasts (HSFB). MethodsHuman HSFB and human normal skin fibroblasts (NSFB) were used in this study, and ClC-3 interference vectors were constructed to transfect cells. ClC-3 inhibitors NPPB and Tamoxifen were used to treat cells. Cell migration and the expression of TGF-β/Smad, CollagenⅠ,CollagenⅢ were examined to explore the role of ClC-3 in the formation of hypertrophic scar. ResultsCompared with the normal skin tissue, the positive expression of ClC-3 and TGF–β in the scar tissue was significantly increased. The relative expression of ClC-3 and TGF-β1 in HSFB cells was higher than that in NSFB cells. Interfering with the expression of CLC-3 can inhibit the migration of HSFB cells and the expression of TGF- β/Smad, CollagenⅠ/Ⅲ. The experiment of HSFB cells treated by CLC-3 inhibitors can also obtain similar results. ConclusionInhibiting CLC-3 can reduce the formation of hypertrophic scars.

Effect and mechanism of action of botulinum toxin type A on hypertrophic scar &lt;i&gt;in vitro&lt;/i&gt;

Purpose: To examine the effect of botulinum toxin type A (BTXA) on the formation of hypertrophic scar and to unravel its mechanism of action.&#x0D; Methods: HSF cells were isolated from hypertrophic scars and cultured. Immunohistochemistry (IHC) assays were performed to determine TGF-β1, FN, and Col1 expressions in hypertrophic scar and normal tissues while the expressions and phosphorylation of p38, ERK, JNK, as well as the expressions of α-SMA, Col1 and FN1 in HSF cells were evaluated by immunoblot techniques. CCK-8 and Transwell assays were used to assess the effect of BTXA on the viability and motility of HSF cells.&#x0D; Results: BTXA suppressed MAPK pathway in hypertrophic scar fibroblasts (p &lt; 0.01). It also suppressed excessive collagen deposits in hypertrophic scar through MAPK pathway (p &lt; 0.01), and restrained HSF growth and motility via MAPK pathway (p &lt; 0.01).&#x0D; Conclusion: BTXA suppresses hypertrophic scarring via MAPK pathway and thus, can potentially be developed as a drug for the treatment of hypertrophic scarring.

Zeolitic imidazolate framework-90 loaded with methylprednisolone sodium succinate effectively reduces hypertrophic scar in vivo.

Hypertrophic scar (HS) is characterized by an abnormal fibroblast-myofibroblast transformation; non-apoptosis of fibroblasts; and redundant expression of TGF-β1, VEGF, α-SMA, and collagen I/III. An HS affects patients' physical and psychological quality of life, leading to joint dysfunction and skin cancer. However, there is currently no satisfactory drug to treat this disorder. In this study, we constructed methylprednisolone sodium succinate (MPSS) encapsulated ZIF-90 (MPSS@ZIF-90) for the effective treatment of an HS. The encapsulation of MPSS in ZIF-90 can achieve the controllable drug release of MPSS and prolong its effective treatment time. MPSS@ZIF-90 enhanced the apoptosis of human hypertrophic scar fibroblasts and downregulated the overexpression of TGF-β1, VEGF, α-SMA, and collagen I/III both in vitro and in vivo. The instant injection of MPSS@ZIF-90 effectively intervened with the formation of the HS after 28 days. On the contrary, MPSS@ZIF-90 greatly reduced the HS with two injections and 14 days of treatment after the HS was formed. This work provides evidence of effective intervention in the formation of an HS and the therapeutic effectiveness of MPSS@ZIF-90 with short treatment periods in vivo. It suggests that MPSS@ZIF-90 can be used as a biomedical option in the treatment of skin wounds and may reveal the potential molecular basis for promising future antifibrotic agents against scarring.

Drugs targeting TGF-β/Notch interaction attenuate hypertrophic scar formation by optic atrophy 1-mediated mitochondrial fusion.

Hypertrophic scar (HS) formation is a cutaneous fibroproliferative disease that occurs after skin injuries and results in severe functional and esthetic disability. To date, few drugs have shown satisfactory outcomes for the treatment of HS formation. Transforming growth factor-beta (TGF-β)/Notch interaction via small mothers against decapentaplegic 3 (Smad3) could facilitate HS formation; therefore, targeting TGF-β/ Notch interaction via Smad3 is a potential therapeutic strategy to attenuate HS formation. In addition, optic atrophy 1 (OPA1)-mediated mitochondrial fusion contributes to fibroblast proliferation, and TGF-β/Smad3 axis and the Notch1 pathway facilitate OPA1-mediated mitochondrial fusion. Thus, the aim of this study was to investigate whether drugs targeting TGF-β/Notch interaction via Smad3 suppressed fibroblast proliferation to attenuate HS formation through OPA1-mediated mitochondrial fusion. We found that the TGF-β pathway, Notch pathway, and TGF-β/Notch interaction via Smad3 were inhibited by pirfenidone, the gamma- secretase inhibitor DAPT, and SIS3 in human keloid fibroblasts (HKF) and an HS rat model, respectively. Protein interaction was detected by co-immunoprecipitation, and mitochondrial morphology was determined by electron microscopy. Our results indicated that pirfenidone, DAPT, and SIS3 suppressed the proliferation of HKFs and attenuated HS formation in the HS rat model by inhibiting TGF-β/Notch interaction via Smad3. Moreover, pirfenidone, DAPT, and SIS3 hindered OPA1-mediated mitochondrial fusion through inhibiting TGF-β/Notch interaction, thereby suppressing the proliferation of HS fibroblasts and HS formation. In summary, these findings investigating the effects of drugs targeting TGF-β/Notch interaction on HS formation might lead to novel drugs for the treatment of HS formation.

ALA-PDT promotes the death and contractile capacity of hypertrophic scar fibroblasts through inhibiting the TGF-β1/Smad2/3/4 signaling pathway

BackgroundHypertrophic scars, an abnormal wound-healing response to burn injuries, are characterized by massive fibroblast proliferation and excessive deposition of extracellular matrix and collagen. 5-aminolevulinic acid-based photodynamic therapy (ALA-PDT) is a promising therapy for hypertrophic scar, details of the mechanisms remain to be elucidated. In this study, we aimed to investigate the molecular mechanisms involved in ALA-PDT against hypertrophic scar fibroblasts. MethodsThe morphologies of hypertrophic scar fibroblasts (HSFs) treated with ALA-PDT were observed under a light microscopy. The viability of HSFs was detected using the CCK-8 assay. HSFs-populated collagen gel contraction assays were conducted to examine the fibroblast contractility and the cytotoxicity of HSFs in 3D collagen tissues were observed using confocal microscopy. The effect of ALA-PDT on TGF-β1/Smad2/3/4 signaling pathway activation and effector gene expression were verified by immunoprecipitation, western blot and real-time quantitative PCR analysis. ResultsWe observed significant changes in cell morphology after ALA-PDT treatment of HSFs. As ALA concentration and light dose increased, the viability of HSFs significantly decreased. ALA-PDT can significantly alleviate the contractile capacity and promote the death of HSFs induced by TGF-β1 treatment in a three-dimensional collagen culture model. TGF-β1 treatment of HSFs can significantly induce phosphorylation of Smad2/3 (p-Smad2/3) in whole cells, as well as p-Smad2/3 and Smad4 proteins into the nucleus and increase the mRNA levels of collagen 1/3 and α-SMA. ALA-PDT hampers the TGF-β1-Smad2/3/4 signaling pathway activation by inducing K48-linked ubiquitination and degradation of Smad4. ConclusionsOur results provide evidence that ALA-PDT can inhibit fibroblast contraction and promote cell death by inhibiting the activation of the TGF-β1 signaling pathway that mediates hypertrophic scar formation, which may be the basis for the efficacy of ALA-PDT in the treatment of hypertrophic scars.

Verteporfin‐Loaded Bioadhesive Nanoparticles for the Prevention of Hypertrophic Scar

AbstractHypertrophic scarring (HS) is a common skin injury complication with unmet needs. Verteporfin (VP) should be an ideal HS‐targeted therapeutic drug due to its efficient fibrosis and angiogenesis inhibitory abilities. However, its application is restricted by its side effects such as dose‐dependent cytotoxicity on normal cells. Herein, the bioadhesive nanoparticles encapsulated VP (VP/BNPs) are successfully developed to attenuate the side effects of VP and enhance its HS inhibition effects by limiting VP releasing slowly and stably in the lesion site but not diffusing easily to normal tissues. VP/BNPs displayed significant inhibition on the proliferation, migration, collagen deposition, and vessel formation of human hypertrophic scar fibroblasts (HSFBs) and dermal vascular endothelial cells (HDVECs). In a rat tail HS model, VP/BNPs treated HS exhibits dramatic scar repression with almost no side effects compared with free VP or VP‐loaded non‐bioadhesive nanoparticles (VP/NNPs) administration. Further immunofluorescence analysis on scar tissue serial sections validated VP/BNPs effectively inhibited the collagen deposition and angiogenesis by firmly confined in the scar tissue and persistently releasing VP targeted to nucleus Yes‐associated protein (nYAP) of HSFBs and HDVECs. These findings collectively suggest that VP/BNPs can be a promising and technically advantageous agent for HS therapies.

The mechanism of Semen Persicae-Flos Carthami in treating hypertrophic scar: A study based on network pharmacological analysis and invitro experiments.

Traditional medicine believes that hypertrophic scar (HS) falls into the category of "blood stasis". Chinese herbs for promoting blood circulation and removing blood stasis, activating meridians, and relieving pain are usually selected to treat HS by traditional Chinese medicine (TCM). Both Semen Persicae (SP) and Flos Carthami (FC) are confirmed to be effective for HS. Clinically, SP and FC are often used in combination with each other. However, the pharmacodynamic mechanism and molecular target of SP-FC in the treatment of HS are still unclear. Therefore, this study is intended to explore the mechanism and target of SP-FC in the treatment of HS through network pharmacology combined with invitro cell and molecular biology experiments. Target genes of SP-FC were obtained from the traditional Chinese medicine systems pharmacology database and analysis platform (TCMSP), and targets of HS-related diseases were searched from databases such as Disgenet and GeneCards. Based on the targets searched and obtained, a Venn diagram was plotted to acquire common targets of SP-FC-HS. Next, STRING 11.0 was employed for protein-protein interaction (PPI) network analysis of common targets; and cytoscape 3.9.0 for connection relationship analysis of PPI and plotting of a "drug-component-target" network diagram. Besides, a modified explant culture method was applied to separate primary hypertrophic scar fibroblasts (HSFs); MTT assay to detect cell viability of HSFs after treatment by SP-FC for 24 h; Annexin V-FITC/PI double staining combined with flow cytometry to test apoptosis; western blot to check the protein expression level of p53; and real-time fluorescence quantitative PCR to determine mRNA level of p53. In the analysis of network pharmacology, 269 pharmacological targets of SP, 449 pharmacological targets of FC, and 2569 targets of HS-related diseases were screened from the databases. After plotting the Venn diagram, 116 common targets of SP-FC-HS were acquired. In vitro experiments showed that the expression of p53 in HSFs was decreased. SP-FC significantly reduces the viability of HSFs, increases p53 levels in HSFs, and promotes apoptosis. SP-FC can reduce scar formation by promoting p53 expression.

Tissue and Cell Dual‐Penetrating Dendritic Lipopeptide Liposomes for Hypertrophic Scar Treatment

AbstractHypertrophic scar is a complex global disease, which can lead to remarkable functional impairment, pruritus, and pain. Treating local skin diseases needs a transdermal drug delivery system that can simultaneously promote cell and tissue penetration within the hypertrophic scar. Herein, a tissue and cell dual‐penetrating liposomal delivery platform consisting of arginine‐based dendritic lipopeptide mimicking the pivotal amino acid sequence in viral protein transduction domains and virion‐like nanostructure to enhance hypertrophic scar tissue deep penetration and cellular internalization is reported. This dendritic lipopeptide liposomal delivery platform can overcome corneum barriers to the punch on hypertrophic scar fibroblast membranes, as are natural viruses. It also can deeply deliver drugs to promote hypertrophic scar fibroblast apoptosis and collagen fiber remodeling within thickened dermis and epidermis, and finally remove the raised scars.

Machine learning and single-cell transcriptome profiling reveal regulation of fibroblast activation through THBS2/TGFβ1/P-Smad2/3 signalling pathway in hypertrophic scar.

Hypertrophic scar (HS) is a chronic inflammatory skin disorder characterized by excessive deposition of extracellular matrix, and the mechanisms underlying their formation remain poorly understood. We analysed scRNA-seq data from samples of normal skin and HS. Using the hdWGCNA method, key gene modules of fibroblasts in HS were identified. Non-negative matrix factorization was employed to perform subtype analysis of HS patients using these gene modules. Multiple machine learning algorithms were applied to screen and validate accurate gene signatures for identifying and predicting HS, and a convolutional neural network (CNN) based on deep learning was established and validated. Quantitative reverse transcription-polymerase chain reaction and western blotting were performed to measure mRNA and protein expression. Immunofluorescence was used for gene localization analysis, and biological features were assessed through CCK8 and wound healing assay. Single-cell sequencing revealed distinct subpopulations of fibroblasts in HS. HdWGCNA identified key gene characteristics of this population, and pseudotime analysis was conducted to investigate gene variation during fibroblast differentiation. By employing various machine learning algorithms, the gene range was narrowed down to three key genes. A CNN was trained using the expression of these key genes and immune cell infiltration, enabling diagnosis and prediction of HS. Functional experiments demonstrated that THBS2 is associated with fibroblast proliferation and migration in HS and affects the formation and development of HS through the TGFβ1/P-Smad2/3 pathway. Our study identifies unique fibroblast subpopulations closely associated with HS and provides biomarkers for the diagnosis and treatment of HS.

Knockdown of ZEB1 Inhibits Hypertrophic Scarring through Suppressing the Wnt/β-catenin Signaling Pathway in a Mouse Model.

Hypertrophic scars (HS) cause functional impairment and cosmetic deformities following surgeries or burns (30% to 94%). There is no target therapy yet because the pathogenesis of HS progression is not well-known. In tissue fibrosis, Zinc finger E-box binding homeobox 1 (ZEB1) abnormal upregulation is an important cause for extracellular matrix (ECM) overexpression, which is the main molecular change in HS. Therefore, we hypothesized that ZEB1-knockdown inhibits HS formation. ZEB1 expression in human HS and TGF-β1-induced fibroblasts were identified by PCR and western blotting. ZEB1 was knockdown by siRNA in HS fibroblasts (HSFs) and mouse HS model (C57/BL6, male, 8-12 weeks). After 8-hour-transfection, HSFs were subjected to PCR, western blotting and CCK-8, apoptosis, migration and contraction assays. Mice HS were analyzed by HE staining, PCR and western blotting after 56 days. ZEB1 was upregulated in HS tissue (2.0-fold; p < 0.001). ZEB1 knockdown inhibited HSFs activity (0.6 to 0.7-fold; p < 0.001), the expression of fibrotic markers (0.4 to 0.6-fold; p < 0.001) and β-catenin, cyclinD1 and c-Myc expression (0.5-fold; p < 0.001). In mouse HS models, HS skin thickness was thinner (1.60 ± 0.40 mm vs. 4.04 ± 0.36 mm; p < 0.001) after ZEB1 knockdown. Knockdown of ZEB1 inhibits HS formation both in vitro and in vivo. However, this is an in vitro/mouse model and more validation is needed. The discovery of ZEB1 as a mediator of HS formation might be a potential therapeutic target in HS treatment.

Exosome Derived from Mesenchymal Stem Cells Alleviates Hypertrophic Scar by Inhibiting the Fibroblasts via TNFSF-13/HSPG2 Signaling Pathway.

Mesenchymal stem cell-derived exosomes (MSC-exo) have been shown to have significant potential in wound healing and scar relief processes. According to reports, TNFSF13 and HSPG2 are associated with various fibrotic diseases. The aim of this study is to investigate how TNFSF13 and HSPG2 affect the formation of hypertrophic scar (HS) and the mechanism by which exosomes regulate HS. Immunohistochemistry, qRT-PCR, Western blot, and immunofluorescence were performed to measure TNFSF13 expression in HS skin tissues and hypertrophic scar fibroblast (HSF). HSF were treated with recombinant TNFSF13 protein and TNFSF13 siRNAs to probe the effect of TNFSF13 on the activity of HSF. The CCK-8, EdU, Transwell, and Western blot were used to investigate the role of TNFSF13 in viability, proliferation and inflammation. The influence of MSC-exo on the proliferation and function of HSF was determined by scratch and Western blot. TNFSF13 was dramatically up-regulated in HS skin tissues and HSF. Recombinant TNFSF13 protein increased cell viability, proliferation, migration, fibrosis, inflammation, and the binding between TNFSF13 and HSPG2 of HSF. The opposite results were obtained in TNFSF13 siRNAs transferred HSF. Furthermore, TNFSF13 activated the nuclear factor-κB (NF-κB) signaling pathway. Silencing of HSPG2 and inhibition of NF-κB remarkably eliminated the promoting effects of TNFSF13 on cell viability, proliferation, migration, fibrosis and inflammation of HSF. MSC-exo reduced α-SMA and COL1A1 inhibited the proliferation and migration of HSF by inhibiting TNFSF13 and HSPG2. TNFSF13 activates NF-κB signaling pathway by interacting with HSPG2, which regulates the proliferation, migration, fibrosis and inflammatory response of HSF. Through the above mechanisms, knocking out TNFSF13 can inhibit the proliferation, migration, fibrosis and inflammatory response of HSF, whereas MSC-exo could reverse this process. These results suggest that MSC-exo alleviates HS by inhibiting the fibroblasts via TNFSF-13/HSPG2 signaling pathway.