Activating transcription factor 3 (ATF3) regulates cell growth, apoptosis, invasion and collagen synthesis in keloid fibroblast through transforming growth factor beta (TGF-beta)/SMAD signaling pathway

TRIM24 Cooperates with Ras Mutation to Drive Glioma Progression through snoRNA Recruitment of PHAX and DNA-PKcs

The factors driving glioma progression remain poorly understood. Here, the epigenetic regulator TRIM24 is identified as a driver of glioma progression, where TRIM24 overexpression promotes HRasV12 anaplastic astrocytoma (AA) progression into epithelioid GBM (Ep-GBM)-like tumors. Co-transfection of TRIM24 with HRasV12 also induces Ep-GBM-like transformation of human neural stem cells (hNSCs) with tumor protein p53 gene (TP53) knockdown. Furthermore, TRIM24 is highly expressed in clinical Ep-GBM specimens. Using single-cell RNA-sequencing (scRNA-Seq), the authors show that TRIM24 overexpression impacts both intratumoral heterogeneity and the tumor microenvironment. Mechanically, HRasV12 activates phosphorylated adaptor for RNA export (PHAX) and upregulates U3 small nucleolar RNAs (U3 snoRNAs) to recruit Ku-dependent DNA-dependent protein kinase catalytic subunit (DNA-PKcs). Overexpressed TRIM24 is also recruited by PHAX to U3 snoRNAs, thereby facilitating DNA-PKcs phosphorylation of TRIM24 at S767/768 residues. Phosphorylated TRIM24 induces epigenome and transcription factor network reprogramming and promotes Ep-GBM-like transformation. Targeting DNA-PKcs with the small molecule inhibitor NU7441 synergizes with temozolomide to reduce Ep-GBM tumorigenicity and prolong animal survival. These findings provide new insights into the epigenetic regulation of Ep-GBM-like transformation and suggest a potential therapeutic strategy for patients with Ep-GBM.

Serum deprivation protein response intervenes in the proliferation, motility, and extracellular matrix production in keloid fibroblasts by blocking the amplification of TGF-β1/SMAD signal cascade via ERK1/2

Keloid formation has been linked to abnormal fibroblast function, such as excessive proliferation and extracellular matrix (ECM) production. Serum deprivation protein response (SDPR) is a crucial regulator of cellular function under diverse pathological conditions, yet its role in keloid formation remains unknown. The current work investigated the function of SDPR in regulating the proliferation, motility, and ECM production of keloid fibroblasts (KFs), as well as to decipher the mechanisms involved. Analysis of RNA sequencing data from the GEO database demonstrated significant down-regulation of SDPR in KF compared to normal fibroblasts (NFs). This down-regulation was also observed in clinical keloid specimens and isolated KFs. Overexpression of SDPR suppressed the proliferation, motility, and ECM production of KFs, while depletion of SDPR exacerbated the enhancing impact of TGF-β1 on the proliferation, motility, and ECM production of NFs. Mechanistic studies revealed that SDPR overexpression repressed TGF-β/Smad signal cascade activation in KFs along with decreased levels of phosphorylated Samd2/3, while SDPR depletion exacerbated TGF-β/Smad activation in TGF-β1-stimulated NFs. SDPR overexpression also repressed ERK1/2 activation in KFs, while SDPR depletion exacerbated ERK1/2 activation in TGF-β1-stimulated NFs. Inhibition of ERK1/2 abolished SDPR-depletion-induced TGF-β1/Smad activation, cell proliferation, motility, and ECM production in NFs. In conclusion, SDPR represses the proliferation, motility, and ECM production in KFs by blocking the TGF-β1/Smad pathway in an ERK1/2-dependent manner. The findings highlight the role of SDPR in regulating abnormal behaviors of fibroblasts associated with keloid formation and suggest it as a potential target for anti-keloid therapy development.

Harnessing the power of bee venom for therapeutic and regenerative medical applications: an updated review

Honeybees have been helpful insects since ancient centuries, and this benefit is not limited to being a honey producer only. After the bee stings a person, pain, and swelling occur in this place, due to the effects of bee venom (BV). This is not a poison in the total sense of the word because it has many benefits, and this is due to its composition being rich in proteins, peptides, enzymes, and other types of molecules in low concentrations that show promise in the treatment of numerous diseases and conditions. BV has also demonstrated positive effects against various cancers, antimicrobial activity, and wound healing versus the human immunodeficiency virus (HIV). Even though topical BV therapy is used to varying degrees among countries, localized swelling or itching are common side effects that may occur in some patients. This review provides an in-depth analysis of the complex chemical composition of BV, highlighting the diverse range of bioactive compounds and their therapeutic applications, which extend beyond the well-known anti-inflammatory and pain-relieving effects, showcasing the versatility of BV in modern medicine. A specific search strategy was followed across various databases; Web of sciences, Scopus, Medline, and Google Scholar including in vitro and in vivo clinical studies.to outline an overview of BV composition, methods to use, preparation requirements, and Individual consumption contraindications. Furthermore, this review addresses safety concerns and emerging approaches, such as the use of nanoparticles, to mitigate adverse effects, demonstrating a balanced and holistic perspective. Importantly, the review also incorporates historical context and traditional uses, as well as a unique focus on veterinary applications, setting it apart from previous works and providing a valuable resource for researchers and practitioners in the field.

Identification of novel immune-related signatures for keloid diagnosis and treatment: insights from integrated bulk RNA-seq and scRNA-seq analysis

BACKGROUND

Keloid is a disease characterized by proliferation of fibrous tissue after the healing of skin tissue, which seriously affects the daily life of patients. However, the clinical treatment of keloids still has limitations, that is, it is not effective in controlling keloids, resulting in a high recurrence rate. Thus, it is urgent to identify new signatures to improve the diagnosis and treatment of keloids.

METHOD

Bulk RNA seq and scRNA seq data were downloaded from the GEO database. First, we used WGCNA and MEGENA to co-identify keloid/immune-related DEGs. Subsequently, we used three machine learning algorithms (Randomforest, SVM-RFE, and LASSO) to identify hub immune-related genes of keloid (KHIGs) and investigated the heterogeneous expression of KHIGs during fibroblast subpopulation differentiation using scRNA-seq. Finally, we used HE and Masson staining, quantitative reverse transcription-PCR, western blotting, immunohistochemical, and Immunofluorescent assay to investigate the dysregulated expression and the mechanism of retinoic acid in keloids.

RESULTS

In the present study, we identified PTGFR, RBP5, and LIF as KHIGs and validated their diagnostic performance. Subsequently, we constructed a novel artificial neural network molecular diagnostic model based on the transcriptome pattern of KHIGs, which is expected to break through the current dilemma faced by molecular diagnosis of keloids in the clinic. Meanwhile, the constructed IG score can also effectively predict keloid risk, which provides a new strategy for keloid prevention. Additionally, we observed that KHIGs were also heterogeneously expressed in the constructed differentiation trajectories of fibroblast subtypes, which may affect the differentiation of fibroblast subtypes and thus lead to dysregulation of the immune microenvironment in keloids. Finally, we found that retinoic acid may treat or alleviate keloids by inhibiting RBP5 to differentiate pro-inflammatory fibroblasts (PIF) to mesenchymal fibroblasts (MF), which further reduces collagen secretion.

CONCLUSION

In summary, the present study provides novel immune signatures (PTGFR, RBP5, and LIF) for keloid diagnosis and treatment, and identifies retinoic acid as potential anti-keloid drugs. More importantly, we provide a new perspective for understanding the interactions between different fibroblast subtypes in keloids and the remodeling of their immune microenvironment.

Lapagyl mitigates UV-induced inflammation and immunosuppression via Foxp3+ Tregs and CCL pathway: A single-cell transcriptomics study

BACKGROUND

As the largest organ of the body, the skin is constantly subjected to ultraviolet radiation (UVR), leading to inflammations and changes that mirror those seen in chronological aging. Although various small molecule drugs have been explored for treating skin photoaging, they typically suffer from low stability and a high incidence of adverse reactions. Consequently, the continued investigation of photoaging treatments, particularly those utilizing herbal products, remains a critical clinical endeavor. One such herbal product, Lapagyl, is derived from the bark of the lapacho tree and possesses antioxidant efficacies that could be beneficial in combating skin photoaging.

PURPOSE

This research aimed to evaluate the efficacy of the herbal product Lapagyl in combating UVR-induced skin photoaging. Additionally, it sought to unravel the mechanisms by which Lapagyl promotes the regeneration of the skin extracellular matrix.

METHODS

To investigate whether Lapagyl can alleviate skin aging and damage, a UVR radiation model was established using SKH-1 hairless mice. The dorsal skins of these mice were evaluated for wrinkle formation, texture, moisture, transepidermal water loss (TEWL), and elasticity. Pathological assessments were conducted to determine Lapagyl's efficacy. Additionally, single-cell sequencing and spectrum analysis were employed to elucidate the working mechanisms and primary components of Lapagyl in addressing UVR-induced skin aging and injury.

RESULTS

Lapagyl markedly reduced UVR-induced wrinkles, moisture loss, and elasticity decrease in SKH-1 mice. Single-cell sequencing demonstrated that Lapagyl corrected the imbalance in cell proportions caused by UVR, decreased UVR-induced ROS expression, and protected basal and spinous cells from skin damage. Additionally, Lapagyl effectively prevented the entry of inflammatory cells into the skin by reducing CCL8 expression and curtailed the UVR-induced formation of Foxp3+ regulatory T cells (Tregs) in the skin. Both pathological assessments and ex vivo skin model results demonstrated that Lapagyl effectively reduced UVR-induced damage to collagen and elastin. Spectrum analysis identified Salidroside as the primary compound remaining in the skin following Lapagyl treatment. Taken together, our study elucidated the skin protection mechanism of the herbal product Lapagyl against UVR damage at the cellular level, revealing its immunomodulatory effects, with salidroside identified as the primary active compound for skin.

CONCLUSION

Our study provided a thorough evaluation of Lapagyl's protective effects on skin against UVR damage, delving into the mechanisms at the cellular level. We discovered that Lapagyl mitigates skin inflammation and immunosuppression by regulating Foxp3+ Tregs and the CCL pathway. These insights indicate that Lapagyl has potential as a novel therapeutic option for addressing skin photoaging.

Spatiotemporal ATF3 Expression Determines VSMC Fate in Abdominal Aortic Aneurysm

BACKGROUND

Abdominal aortic aneurysm (AAA) is a catastrophic disease with little effective therapy, likely due to the limited understanding of the mechanisms underlying AAA development and progression. ATF3 (activating transcription factor 3) has been increasingly recognized as a key regulator of cardiovascular diseases. However, the role of ATF3 in AAA development and progression remains elusive.

METHODS

Genome-wide RNA sequencing analysis was performed on the aorta isolated from saline or Ang II (angiotensin II)-induced AAA mice, and ATF3 was identified as the potential key gene for AAA development. To examine the role of ATF3 in AAA development, vascular smooth muscle cell-specific ATF3 knockdown or overexpressed mice by recombinant adeno-associated virus serotype 9 vectors carrying ATF3, or shRNA-ATF3 with SM22α (smooth muscle protein 22-α) promoter were used in Ang II-induced AAA mice. In human and murine vascular smooth muscle cells, gain or loss of function experiments were performed to investigate the role of ATF3 in vascular smooth muscle cell proliferation and apoptosis.

RESULTS

In both Ang II-induced AAA mice and patients with AAA, the expression of ATF3 was reduced in aneurysm tissues but increased in aortic lesion tissues. The deficiency of ATF3 in vascular smooth muscle cell promoted AAA formation in Ang II-induced AAA mice. PDGFRB (platelet-derived growth factor receptor β) was identified as the target of ATF3, which mediated vascular smooth muscle cell proliferation in response to TNF-alpha (tumor necrosis factor-α) at the early stage of AAA. ATF3 suppressed the mitochondria-dependent apoptosis at the advanced stage by upregulating its direct target BCL2. Our chromatin immunoprecipitation results also demonstrated that the recruitment of NFκB1 and P300/BAF/H3K27ac complex to the ATF3 promoter induces ATF3 transcription via enhancer activation. NFKB1 inhibitor (andrographolide) inhibits the expression of ATF3 by blocking the recruiters NFKB1 and ATF3-enhancer to the ATF3-promoter region, ultimately leading to AAA development.

CONCLUSIONS

Our results demonstrate a previously unrecognized role of ATF3 in AAA development and progression, and ATF3 may serve as a novel therapeutic and prognostic marker for AAA.

Vitamin D Attenuates Fibrotic Properties of Fibrous Dysplasia-Derived Cells for the Transit towards Osteocytic Phenotype

Fibrous dysplasia (FD) poses a therapeutic challenge due to the dysregulated extracellular matrix (ECM) accumulation within affected bone tissues. In this study, we investigate the therapeutic potential of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) in managing FD by examining its effects on FD-derived cells in vitro. Our findings demonstrate that 1,25(OH)2D3 treatment attenuates the pro-fibrotic phenotype of FD-derived cells by suppressing the expression of key pro-fibrotic markers and inhibiting cell proliferation and migration. Moreover, 1,25(OH)2D3 enhances mineralization by attenuating pre-osteoblastic cellular hyperactivity and promoting maturation towards an osteocytic phenotype. These results offer valuable insights into potential treatments for FD, highlighting the role of 1,25(OH)2D3 in modulating the pathological properties of FD-derived cells.

Advances in photodynamic therapy of pathologic scar

Pathologic scars include keloids and hypertrophic scars due to abnormal wound healing. Both cause symptoms of itching and pain; they also affect one's appearance and may even constrain movement. Such scars place a heavy burden on the individual's physical and mental health; moreover, treatment with surgery alone is highly likely to leave more scarring. Therefore, there is an urgent need for a treatment that is both minimally invasive and convenient. Photodynamic therapy (PDT) is an emerging safe and noninvasive technology wherein photosensitizers and specific light sources are used to treat malignant tumors and skin diseases. Research on PDT from both the laboratory and clinic has been reported. These findings on the treatment of pathologic scars using photosensitizers, light sources, and other mechanisms are reviewed in the present article.

Glutamate is effective in decreasing opacity formed in galactose-induced cataract model

Although cataract is the leading cause of blindness worldwide, the detailed pathogenesis of cataract remains unclear, and clinically useful drug treatments are still lacking. In this study, we examined the effects of glutamate using an ex vivo model in which rat lens is cultured in a galactose-containing medium to induce opacity formation. After inducing lens opacity formation in galactose medium, glutamate was added, and the opacity decreased when the culture was continued. Next, microarray analysis was performed using samples in which the opacity was reduced by glutamate, and genes whose expression increased with galactose culture and decreased with the addition of glutamate were extracted. Subsequently, STRING analysis was performed on a group of genes that showed variation as a result of quantitative measurement of gene expression by RT-qPCR. The results suggest that apoptosis, oxidative stress, endoplasmic reticulum (ER) stress, cell proliferation, epithelial-mesenchymal transition (EMT), cytoskeleton, and histones are involved in the formation and reduction of opacity. Therefore, glutamate may reduce opacity by inhibiting oxidative stress and its downstream functions, and by regulating the cytoskeleton and cell proliferation.

Bioinformatics and Integrative Experimental Method to Identifying and Validating Co-Expressed Ferroptosis-Related Genes in OA Articular Cartilage and Synovium

Purpose

Osteoarthritis (OA) is the most common joint disease worldwide and is the primary cause of disability and chronic pain in older adults.Ferroptosis is a type of programmed cell death characterized by aberrant iron metabolism and reactive oxygen species accumulation; however, its role in OA is not known.

Methods

To identify ferroptosis markers co-expressed in articular cartilage and synovium samples from patients with OA, in silico analysis was performed.Signature genes were analyzed and the results were evaluated using a ROC curve prediction model.The biological function, correlation between Signature genes, immune cell infiltration, and ceRNA network analyses were performed. Signature genes and ferroptosis phenotypes were verified through in vivo animal experiments and clinical samples. The expression levels of non-coding RNAs in samples from patients with OA were determined using qRT-PCR. ceRNA network analysis results were confirmed using dual-luciferase assays.

Results

JUN, ATF3, and CDKN1A were identified as OA- and ferroptosis-associated signature genes. GSEA analysis demonstrated an enrichment of these genes in immune and inflammatory responses, and amino acid metabolism. The CIBERSORT algorithm showed a negative correlation between T cells and these signature genes in the cartilage, and a positive correlation in the synovium. Moreover, RP5-894D12.5 and FAM95B1 regulated the expression of JUN, ATF3, and CDKN1A by competitively binding to miR-1972, miR-665, and miR-181a-2-3p. In vivo, GPX4 was downregulated in both OA cartilage and synovium; however, GPX4 and GSH were downregulated, while ferrous ions were upregulated in patient OA cartilage and synovium samples, indicating that ferroptosis was involved in the pathogenesis of OA. Furthermore, JUN, ATF3, and CDKN1A expression was downregulated in both mouse and human OA synovial and cartilage tissues. qRT-PCR demonstrated that miR-1972, RP5-894D12.5, and FAM95B1 were differentially expressed in OA tissues. Targeted interactions between miR-1972 and JUN, and a ceRNA regulatory mechanism between RP5-894D12.5, miR-1972, and JUN were confirmed by dual-luciferase assays.

Conclusion

This study identified JUN, ATF3, and CDKN1A as possible diagnostic biomarkers and therapeutic targets for joint synovitis and OA. Furthermore, our finding indicated that RP5-894D12.5/miR-1972/JUN was a potential ceRNA regulatory axis in OA, providing an insight into the connection between ferroptosis and OA.

Serum-Induced Proliferation of Human Cardiac Stem Cells Is Modulated via TGFβRI/II and SMAD2/3

The ageing phenotype is strongly driven by the exhaustion of adult stem cells (ASCs) and the accumulation of senescent cells. Cardiovascular diseases (CVDs) and heart failure (HF) are strongly linked to the ageing phenotype and are the leading cause of death. As the human heart is considered as an organ with low regenerative capacity, treatments targeting the rejuvenation of human cardiac stem cells (hCSCs) are of great interest. In this study, the beneficial effects of human blood serum on proliferation and senescence of hCSCs have been investigated at the molecular level. We show the induction of a proliferation-related gene expression response by human blood serum at the mRNA level. The concurrent differential expression of the TGFβ target and inhibitor genes indicates the participation of TGFβ signalling in this context. Surprisingly, the application of TGFβ1 as well as the inhibition of TGFβ type I and type II receptor (TGFβRI/II) signalling strongly increased the proliferation of hCSCs. Likewise, both human blood serum and TGFβ1 reduced the senescence in hCSCs. The protective effect of serum on senescence in hCSCs was enhanced by simultaneous TGFβRI/II inhibition. These results strongly indicate a dual role of TGFβ signalling in terms of the serum-mediated effects on hCSCs. Further analysis via RNA sequencing (RNA-Seq) revealed the participation of Ras-inactivating genes wherefore a prevention of hyperproliferation upon serum-treatment in hCSCs via TGFβ signalling and Ras-induced senescence is suggested. These insights may improve treatments of heart failure in the future.

The Dual Roles of Activating Transcription Factor 3 (ATF3) in Inflammation, Apoptosis, Ferroptosis, and Pathogen Infection Responses

Transcription factors are pivotal regulators in the cellular life process. Activating transcription factor 3 (ATF3), a member of the ATF/CREB (cAMP response element-binding protein) family, plays a crucial role as cells respond to various stresses and damage. As a transcription factor, ATF3 significantly influences signal transduction regulation, orchestrating a variety of signaling pathways, including apoptosis, ferroptosis, and cellular differentiation. In addition, ATF3 serves as an essential link between inflammation, oxidative stress, and immune responses. This review summarizes the recent advances in research on ATF3 activation and its role in regulating inflammatory responses, cell apoptosis, and ferroptosis while exploring the dual functions of ATF3 in these processes. Additionally, this article discusses the role of ATF3 in diseases related to pathogenic microbial infections. Our review may be helpful to better understand the role of ATF3 in cellular responses and disease progression, thus promoting advancements in clinical treatments for inflammation and oxidative stress-related diseases.

Advances and future directions in keloid research: Pathogenesis, diagnosis and personalized treatment strategies

Keloids, which are abnormal manifestations of wound healing, can result in significant functional impairment and aesthetic deformities. The pathogenesis of keloids is multifaceted and complex and influenced by various factors, such as genetics, the environment, and immune responses. The evolution of keloid treatment has progressed from traditional surgical excision to a contemporary combination of therapies including injection and radiation treatments, among others. This article provides a comprehensive review of keloid pathogenesis and treatment, emphasizing the latest advances in the field. Ultimately, this review underscores the necessity for continued research to enhance our understanding of keloid pathogenesis and to devise more effective treatments for this challenging condition.

Inhibition of keloid by 32P isotope radiotherapy through suppressing TGF-β/Smad signaling pathway

BACKGROUND

Keloid seriously affects the appearance, and is accompanied by some symptoms including pain, burning, itching. Radioactive nuclides such as 32P have been proved to be effective in inhibiting the formation of keloid, but the mechanism remains unclear.

METHODS

The keloid animal model was established through keloid tissues implantation. Hematoxylin-Eosin (HE) and Masson staining were performed to investigate histological changes and collagen deposition. The mRNA and protein expression were assessed using RT-PCR and western blotting, respectively. Cell apoptosis and cycle were evaluated through flow cytometry.

RESULTS

Both 32P isotope injection and skin path significantly reduced the size of keloid, and inhibited TGF-β/Smad signaling pathway. SRI-011381, the agonist of TGF-β/Smad signaling pathway, markedly reversed the influence of 32P isotope on cell proliferation, cell apoptosis, cell cycle of LNCaP cells and TGF-β/Smad signaling pathway.

CONCLUSIONS

32P isotope injection and skin path greatly reduced the size of keloid, and the TGF-β/Smad signaling pathway was remarkably inhibited by 32P isotope treatment. The regulation of dermal fibroblast by 32P isotope was reversed by SRI-011381. 32P isotope might inhibit keloid through suppressing TGF-β/Smad signaling pathway. Our study provides a novel therapeutic strategy for the treatment of keloid.

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.

CEBP-β and PLK1 as Potential Mediators of the Breast Cancer/Obesity Crosstalk: In Vitro and In Silico Analyses

Over the last two decades, obesity has reached pandemic proportions in several countries, and expanding evidence is showing its contribution to several types of malignancies, including breast cancer (BC). The conditioned medium (CM) from mature adipocytes contains a complex of secretes that may mimic the obesity condition in studies on BC cell lines conducted in vitro. Here, we report a transcriptomic analysis on MCF-7 BC cells exposed to adipocyte-derived CM and focus on the predictive functional relevance that CM-affected pathways/processes and related biomarkers (BMs) may have in BC response to obesity. CM was demonstrated to increase cell proliferation, motility and invasion as well as broadly alter the transcript profiles of MCF-7 cells by significantly modulating 364 genes. Bioinformatic functional analyses unraveled the presence of five highly relevant central hubs in the direct interaction networks (DIN), and Kaplan-Meier analysis sorted the CCAAT/enhancer binding protein beta (CEBP-β) and serine/threonine-protein kinase PLK1 (PLK1) as clinically significant biomarkers in BC. Indeed, CEBP-β and PLK1 negatively correlated with BC overall survival and were up-regulated by adipocyte-derived CM. In addition to their known involvement in cell proliferation and tumor progression, our work suggests them as a possible "deus ex machina" in BC response to fat tissue humoral products in obese women.

The Role of TGF-β Signaling in Saphenous Vein Graft Failure after Peripheral Arterial Disease Bypass Surgery

Saphenous vein bypass grafting is an effective technique used to treat peripheral arterial disease (PAD). However, restenosis is the major clinical challenge for the graft vessel among people with PAD postoperation. We hypothesize that there is a common culprit behind arterial occlusion and graft restenosis. To investigate this hypothesis, we found TGF-β, a gene specifically upregulated in PAD arteries, by bioinformatics analysis. TGF-β has a wide range of biological activities and plays an important role in vascular remodeling. We discuss the molecular pathway of TGF-β and elucidate its mechanism in vascular remodeling and intimal hyperplasia, including EMT, extracellular matrix deposition, and fibrosis, which are the important pathways contributing to stenosis. Additionally, we present a case report of a patient with graft restenosis linked to the TGF-β pathway. Finally, we discuss the potential applications of targeting the TGF-β pathway in the clinic to improve the long-term patency of vein grafts.

Poly-L-Lactic acid increases collagen gene expression and synthesis in cultured dermal fibroblast (Hs68) through the TGF-β/Smad pathway

OBJECTIVE

Poly-L-Lactic Acid (PLLA) is a synthetic polymer which possesses biocompatible and biodegradable properties, and is widely used in the clinical filler material. This study focuses on the potential role of PLLA on the collagen production of dermal fibroblasts and its mechanism.

METHODS

The dermal fibroblast Hs60 was treated with different concentration of PLLA. RT-qPCR was conducted for the determination of mRNA levels of collagen type I (COL1) alpha 1 (COL1A1), COL1 alpha 2 (COL1A2), elastin, matrix metalloproteinase 1 (MMP-1), tissue inhibitor of metalloproteinase 1 (TIMP-1), and TIMP-2. Procollagen Type I C-peptide (PIP) enzyme immunoassay (EIA) Kit assay was carried out to analyze procollagen production. Western Blot was employed to examine the effect of PLLA and transforming frown factor (TGF-β) receptor-specific inhibitor (SB431542) on protein levels of COL1A1 and TGF-β/Smad signaling pathway related proteins.

RESULTS

With the increase of PLLA concentration, the production of procollagen gradually increased, and both protein and mRNA levels of COL1A1 and COL1A2 gradually increased (p < 0.001). Elevated PLLA concentrations increased elastin, TIMP-1, and TIMP-2 levels and attenuated MMP-1 expression. PLLA increased TGF-β levels in a dose-dependently manner. p-Smad2 and p-Smad3 protein levels were also increased by PLLA, but the influences were reversed by SB431542 (p < 0.001). Similarly, increased levels of COL1A1, COL1A2, TIMP-1, and TIMP-2 caused by PLLA were significantly inhibited by SB431542, whereas MMP-1 was typically elevated (p < 0.001).

CONCLUSION

Poly-L-Lactic Acid promotes the collagen production of dermal fibroblasts by activating the TGF-β/Smad signaling pathway. The findings may lay a foundation for clinical material applications of PLLA.

Engineered fibrotic liver-targeted truncated transforming growth factor β receptor type II variant for superior anti-liver fibrosis therapy

Truncated transforming growth factor β receptor type II (tTβRII) is a promising anti-liver fibrotic candidate because it serves as a trap for binding excessive TGF-β1 by means of competing with wild type TβRII (wtTβRII). However, the widespread application of tTβRII for the treatment of liver fibrosis has been limited by its poor fibrotic liver-homing capacity. Herein, we designed a novel tTβRII variant Z-tTβRII by fusing the platelet-derived growth factor β receptor (PDGFβR)-specific affibody Z_PDGFβR to the N-terminus of tTβRII. The target protein Z-tTβRII was produced using Escherichia coli expression system. In vitro and in vivo studies showed that Z-tTβRII has a superior specific fibrotic liver-targeting potential via the engagement of PDGFβR-overexpressing activated hepatic stellate cells (aHSCs) in liver fibrosis. Moreover, Z-tTβRII significantly inhibited cell migration and invasion, and downregulated fibrosis- and TGF-β1/Smad pathway-related protein levels in TGF-β1-stimiluated HSC-T6 cells. Furthermore, Z-tTβRII remarkably ameliorated liver histopathology, mitigated the fibrosis responses and blocked TGF-β1/Smad signaling pathway in CCl₄-induced liver fibrotic mice. More importantly, Z-tTβRII exhibits a higher fibrotic liver-targeting potential and stronger anti-fibrotic effects than either its parent tTβRII or former variant BiPPB-tTβRII (PDGFβR-binding peptide BiPPB modified tTβRII). In addition, Z-tTβRII shows no significant sign of potential side effects in other vital organs in liver fibrotic mice. Taken together, we conclude that Z-tTβRII with its a high fibrotic liver-homing potential, holds a superior anti-fibrotic activity in liver fibrosis in vitro and in vivo, which may be a potential candidate for targeted therapy for liver fibrosis.

Establishment of Ferroptosis-Related Key Gene Signature and Its Validation in Compression-Induced Intervertebral Disc Degeneration Rats

Cell death and functional loss of nucleus pulposus cell play essential roles in intervertebral disc degeneration (IDD). Ferroptosis is a newly identified cell death type, and its role in IDD is still under investigation. Identifying the key genes of ferroptosis in IDD helps to identify the therapeutic targets of IDD. In this study, we downloaded the human IDD mRNA microarray data from the Gene Expression Omnibus and ferroptosis genes from FerrDb, then performed a series of analyses using strict bioinformatics algorithms. In general, we obtained 40 ferroptosis-related differential expression genes (FerrDEGs) and identified six ferroptosis key gene signatures, namely, ATF3, EIF2S1, AR, NQO1, TXNIP, and AKR1C3. In addition, enrichment analysis of the FerrDEGs was conducted, the protein-protein interaction network was constructed, the correlations between ferroptosis key genes and immune infiltrating cells were analyzed, and the lncRNA-miRNA-mRNA ceRNA network was constructed. In particular, ATF3 and EIF2S1 showed the strongest correlation with immune cell function, which might lead to the development of IDD. Finally, the expressions of ferroptosis key genes were verified in the rat compression-induced IDD. In conclusion, this preliminary study analyzed and verified the mechanism of ferroptosis in IDD, laid a foundation for the follow-up study of the mechanism of ferroptosis in IDD, and provided new targets for preventing and delaying IDD.

New Insight into the Concanavalin A-Induced Apoptosis in Hepatocyte of an Animal Model: Possible Involvement of Caspase-Independent Pathway

Concanavalin A (Con A) is known to be a T-cell mitogen and has been shown to induce hepatitis in mice through the triggering of conventional T cells and NKT cells. However, it remains unknown whether Con A itself can directly induce rapid hepatocyte death in the absence of a functional immune system. Here, by using an immunodeficient mouse model, we found Con A rapidly induced liver injury in vivo despite a lack of immunocyte involvement. We further observed in vitro that hepatocytes underwent a dose-dependent but caspase-independent apoptosis in response to Con A stimulation in vitro. Moreover, transcriptome RNA-sequencing analysis revealed that apoptosis pathways were activated in both our in vivo and in vitro models. We conclude that Con A can directly induce rapid but non-classical apoptosis in hepatocytes without the participation of immunocytes. These findings provide new insights into the mechanism of Con A-induced hepatitis.

3D osteogenic differentiation of human iPSCs reveals the role of TGFβ signal in the transition from progenitors to osteoblasts and osteoblasts to osteocytes

Although the formation of bone-like nodules is regarded as the differentiation process from stem cells to osteogenic cells, including osteoblasts and osteocytes, the precise biological events during nodule formation are unknown. Here we performed the osteogenic induction of human induced pluripotent stem cells using a three-dimensional (3D) culture system using type I collagen gel and a rapid induction method with retinoic acid. Confocal and time-lapse imaging revealed the osteogenic differentiation was initiated with vigorous focal proliferation followed by aggregation, from which cells invaded the gel. Invading cells changed their morphology and expressed osteocyte marker genes, suggesting the transition from osteoblasts to osteocytes. Single-cell RNA sequencing analysis revealed that 3D culture-induced cells with features of periosteal skeletal stem cells, some of which expressed TGFβ-regulated osteoblast-related molecules. The role of TGFβ signal was further analyzed in the transition from osteoblasts to osteocytes, which revealed that modulation of the TGFβ signal changed the morphology and motility of cells isolated from the 3D culture, suggesting that the TGFβ signal maintains the osteoblastic phenotype and the transition into osteocytes requires down-regulation of the TGFβ signal.

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.

ATF3 in atherosclerosis: a controversial transcription factor

Atherosclerosis, the pathophysiological basis of most malignant cardiovascular diseases, remains a global concern. Transcription factors play a key role in regulating cell function and disease progression in developmental signaling pathways involved in atherosclerosis. Activated transcription factor (ATF) 3 is an adaptive response gene in the ATF/cAMP response element binding (CREB) protein family that acts as a transcription suppressor or activator by forming homodimers or heterodimers with other ATF/CREB members. Appropriate ATF3 expression is vital for normal physiological cell function. Notably, ATF3 exhibits distinct roles in vascular endothelial cells, macrophages, and the liver, which will also be described in detail. This review provides a new perspective for atherosclerosis therapy by summarizing the mechanism of ATF3 in atherosclerosis, as well as the structure and pathophysiological properties of ATF3. KEY MESSAGES: • In endothelial cells, ATF3 overexpression aggravates oxidative stress and inflammation. • In macrophages and liver cells, ATF3 can act as a negative regulator of inflammation and promote cholesterol metabolism. • ATF3 can be used as a potential therapeutic factor in the treatment of atherosclerosis.

Keloid: Genetic susceptibility and contributions of genetics and epigenetics to its pathogenesis

Keloid, characterized by fibroproliferative disorders of the skin, can be developed in people of different genders, ages, and ethnicities. Keloid can appear in any part of the body but are especially common on the earlobe, upper torso, and triangular muscle. The genetic heterogeneity and susceptibility of KD (keloid) vary among different races and ethnicities. Studies have found that multiple loci on multiple chromosomes are associated with the pathogenesis of KD, and specific gene variants may also be involved. Despite multiple investigations attempting to uncover the etiology of keloid formation, the genetic mechanism of keloid formation remains unknown. To establish a foundation for a better understanding of the genetics and epigenetics of keloids, we have evaluated and summarized current studies which are mostly related to heredity, genetic polymorphisms, predisposing gene, DNA methylation, and non-coding RNA. We also discussed the problems and potential of genetic and epigenetic investigations of keloids, with the goal of developing new therapeutic approaches to enhance the prognosis of keloid patients.

ATF3 as a potential diagnostic marker of early-stage osteoarthritis and its correlation with immune infiltration through bioinformatics analysis

AIMS

This study aimed, through bioinformatics analysis, to identify the potential diagnostic markers of osteoarthritis, and analyze the role of immune infiltration in synovial tissue.

METHODS

The gene expression profiles were downloaded from the Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) were identified by R software. Functional enrichment analyses were performed and protein-protein interaction networks (PPI) were constructed. Then the hub genes were screened. Biomarkers with high value for the diagnosis of early osteoarthritis (OA) were validated by GEO datasets. Finally, the CIBERSORT algorithm was used to evaluate the immune infiltration between early-stage OA and end-stage OA, and the correlation between the diagnostic marker and infiltrating immune cells was analyzed.

RESULTS

A total of 88 DEGs were identified. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses indicated that DEGs were significantly enriched in leucocyte migration and interleukin (IL)-17 signalling pathways. Disease ontology (DO) indicated that DEGs were mostly enriched in rheumatoid arthritis. Six hub genes including FosB proto-oncogene, AP-1 transcription factor subunit (FOSB); C-X-C motif chemokine ligand 2 (CXCL2); CXCL8; IL-6; Jun proto-oncogene, AP-1 transcription factor subunit (JUN); and Activating transcription factor 3 (ATF3) were identified and verified by GEO datasets. ATF3 (area under the curve = 0.975) turned out to be a potential biomarker for the diagnosis of early OA. Several infiltrating immune cells varied significantly between early-stage OA and end-stage OA, such as resting NK cells (p = 0.016), resting dendritic cells (p = 0.043), and plasma cells (p = 0.043). Additionally, ATF3 was significantly correlated with resting NK cells (p = 0.034), resting dendritic cells (p = 0.026), and regulatory T cells (Tregs, p = 0.018).

CONCLUSION

ATF3 may be a potential diagnostic marker for early diagnosis and treatment of OA, and immune cell infiltration provides new perspectives for understanding the mechanism during OA progression.Cite this article: Bone Joint Res 2022;11(9):679-689.

Tumor-associated fibroblasts derived exosomes induce the proliferation and cisplatin resistance in esophageal squamous cell carcinoma cells through RIG-I/IFN-β signaling

Esophageal squamous cell carcinoma (ESCC) is a common type of malignant cancer. There is growing evidence suggesting that exosomes may participate in the cellular communication of tumor-associated fibroblasts (TAFs). However, the cisplatin resistance of TAF-derived exosomes to ESCC cells remains to be further studied. Exosomes were isolated from TAFs and characterized with Western blot and TEM assays. ESCC cell lines (TE-1 and KYSE-150) were incubated with TAFs-derived exosomes. To explore the biological function of TAF-derived exosomes in ESCC cell proliferation, apoptosis, and chemosensitivity, we conducted MTT assays and Flow Cytometry. The effects in vivo were also verified via Xenograft mice models. We found that TAFs-derived exosomes led to enhanced cell proliferation and reduced apoptosis of cells, accompanied by increased expression of RIG-I/IFN-β, and TAFs derived exosomes may affect the chemosensitivity to cisplatin via RIG-I/IFN-β signaling in ESCC. Taken together, ESCC cells could communicate with TAFs cells via TAFs-derived exosomes. Our findings might represent a novel mechanism involved in ESCC and may provide a potential biomarker for ESCC.

CVD and COVID-19: Emerging Roles of Cardiac Fibroblasts and Myofibroblasts

Cardiovascular disease (CVD) is the leading cause of death worldwide. Current data suggest that patients with cardiovascular diseases experience more serious complications with coronavirus disease-19 (COVID-19) than those without CVD. In addition, severe COVID-19 appears to cause acute cardiac injury, as well as long-term adverse remodeling of heart tissue. Cardiac fibroblasts and myofibroblasts, being crucial in response to injury, may play a pivotal role in both contributing to and healing COVID-19-induced cardiac injury. The role of cardiac myofibroblasts in cardiac fibrosis has been well-established in the literature for decades. However, with the emergence of the novel coronavirus SARS-CoV-2, new cardiac complications are arising. Bursts of inflammatory cytokines and upregulation of TGF-β1 and angiotensin (AngII) are common in severe COVID-19 patients. Cytokines, TGF-β1, and Ang II can induce cardiac fibroblast differentiation, potentially leading to fibrosis. This review details the key information concerning the role of cardiac myofibroblasts in CVD and COVID-19 complications. Additionally, new factors including controlling ACE2 expression and microRNA regulation are explored as promising treatments for both COVID-19 and CVD. Further understanding of this topic may provide insight into the long-term cardiac manifestations of the COVID-19 pandemic and ways to mitigate its negative effects.

Exosomes from human adipose-derived mesenchymal stem cells inhibit production of extracellular matrix in keloid fibroblasts via downregulating transforming growth factor-β2 and Notch-1 expression

Keloids are an excessive tissue response to dermal damage, characterized by uncontrolled growth and a high recurrence rate after various treatments. Abnormalities with the extracellular matrix (ECM) are one of the most important contributing factors to the formation of keloids. Although exosomes from human adipose-derived mesenchymal stem cells (adMSC-Exos) have been shown to promote repair and regeneration in wounds, they have seldom been studied for the treatment of keloids. In this study, we aimed to investigate the effects of adMSC-Exos on ECM remodeling in keloids using both in vitro and ex vivo models. The results showed that adMSC-Exos inhibited gene and protein expression of collagen I (COL-1), collagen III (COL-3), fibronectin (FN), and α-smooth muscle actin (α-SMA) in keloid fibroblasts (KFs). Furthermore, using an ex vivo tissue explant model, we found that adMSC-Exos significantly suppressed COL production and disrupted the microvessel stucture. We also demonstrated that adMSC-Exos inhibited the protein expression of Smad3 and Notch-1, and the expression of transforming growth factor β2 (TGF-β2) in KFs, and promoted the expression of TGF-β3. These findings largely explain the mechanisms underlying the inhibition of ECM production in keloids by adMSC-Exos. In conclusion, our results revealed that adMSC-Exos effectively inhibited the production of ECM in keloids, which provides a new potential alternative for the systemic treatment of keloids.

Velvet Antler Peptides Reduce Scarring via Inhibiting the TGF-β Signaling Pathway During Wound Healing

Aim

Scar formation generally occurs in cutaneous wound healing in mammals, mainly caused by myofibroblast aggregations, and currently with few effective treatment options. However, the pedicle wound (about 10 cm in diameter) of the deer can initiate regenerative healing, which has been found to be achieved via paracrine factors from the internal tissues of antlers.

Methods

Enzymatically digested velvet antler peptides (EVAP) were prepared along with other types of antler extracts as the controls. The effects of EVAP on healing of full-thickness skin wounds were evaluated using rats in vivo, and on myofibroblast transdifferentiation tested using transforming growth factor-β1 (TGF-β1)-induced human dermal fibroblasts in vitro.

Results

EVAP significantly accelerated the wound healing rate, reduced scar formation, and improved the healing quality, including promoted angiogenesis, increased number of skin appendages (hair follicles and sebaceous glands) and improved the distribution pattern of collagen fibers (basket-wave like) in the healed tissue. Moreover, EVAP significantly down-regulated the expression levels of genes pro- scar formation (Col1a2 and TGF-β1), and up-regulated the expression levels of genes anti-scar formation (Col3a1 and TGF-β3), and suppressed the excessive transdifferentiation of myofibroblasts and the formation of collagen I in vivo and in vitro. Furthermore, we found these effects were highly likely achieved by inhibiting the TGF-β signaling pathway, evidenced by decreased expression levels of the related genes, including TGF-β1, Smad2, p-Smad2, α-SMA, and collagen I.

Conclusions

EVAP may be a promising candidate to be developed as a clinic drug for regenerative wound healing.

Long-term explant culture: an improved method for consistently harvesting homogeneous populations of keloid fibroblasts

Explant culture is a more suitable method than enzyme digestion for the isolation of keloid fibroblasts (KFs), but it has a longer isolation period. In this study, we propose a long-term explant culture method. Unlike in the conventional explant culture method, we continued culturing explants to isolate KFs rather than discarding them during passage. We demonstrated that keloid explants could be cultured for more than 4 months to continuously yield enriched KFs, and the KFs from the repeatedly cultured explants had shorter isolation times. The biological behavior and fibrotic phenotypic characteristics of the KFs from the explants cultured long term were investigated, and no statistical differences were found compared with the KFs from the original explants. In conclusion, the long-term explant culture method was shown to be efficient for harvesting a large, homogeneous population of KFs. The high efficiency as well as ease of operation and sample saving make this method convenient for researchers working with KFs.

Identification and Validation of ATF3 Serving as a Potential Biomarker and Correlating With Pharmacotherapy Response and Immune Infiltration Characteristics in Rheumatoid Arthritis

Background: Although disease-modifying antirheumatic drugs (DMARDs) have significantly improved the prognosis of patients with rheumatoid arthritis (RA), approximately 40% of RA patients have limited response. Therefore, it was essential to explore new biomarkers to improve the therapeutic effects on RA. This study aimed to develop a new biomarker and validate it by an in vitro study.

Methods: The RNA-seq and the clinicopathologic data of RA patients were downloaded from Gene Expression Omnibus (GEO) databases. Differentially expressed genes were screened in the GPL96 and GPL570 databases. Then, weighted gene co-expression network analysis (WGCNA) was used to explore the most correlated gene modules to normal and RA synovium in the GPL96 and GPL570 databases. After that, the differentially expressed genes were intersected with the correlated gene modules to find the potential biomarkers. The CIBERSORT tool was applied to investigate the relationship between activated transcription factor 3 (ATF3) expression and the immune cell infiltration, and Gene Set Enrichment Analysis (GSEA) was used to investigate the related signaling pathways of differentially expressed genes in the high and low ATF3 groups. Furthermore, the relationships between ATF3 expression and clinical parameters were also explored in the GEO database. Finally, the role of ATF3 was verified by in vitro cell experiments.

Results: We intersected the differentially expressed genes and the most correlated gene modules in the GPL570 and GPL96 databases and identified that ATF3 is a significant potential biomarker and correlates with some clinical–pharmacological variables. Immune infiltration analysis showed that activated mast cells had a significant infiltration in the high ATF3 group in the two databases. GSEA showed that metabolism-associated pathways belonged to the high ATF3 groups and that inflammation and immunoregulation pathways were enriched in the low ATF3 group. Finally, we validated that ATF3 could promote the proliferation, migration, and invasion of RA fibroblast-like synoviocyte (FLS) and MH7A. Flow cytometry showed that ATF3 expression could decrease the proportion of apoptotic cells and increase the proportion of S and G2/M phase cells.

Conclusion: We successfully identified and validated that ATF3 could serve as a novel biomarker in RA, which correlated with pharmacotherapy response and immune cell infiltration.

Activating Transcription Factor 3 Protects against Restraint Stress-Induced Gastrointestinal Injury in Mice

Psychological stress increases the risk of gastrointestinal (GI) tract diseases, which involve bidirectional communication of the GI and nerves systems. Acute stress leads to GI ulcers; however, the mechanism of the native cellular protection pathway, which safeguards tissue integrality and maintains GI homeostasis, remains to be investigated. In a mouse model of this study, restraint stress induced GI leakage, abnormal tight junction protein expression, and cell death of gut epithelial cells. The expression of activating transcription factor 3 (ATF3), a stress-responsive transcription factor, is upregulated in the GI tissues of stressed animals. ATF3-deficient mice displayed an exacerbated phenotype of GI injuries. These results suggested that, in response to stress, ATF3 is part of the native cellular protective pathway in the GI system, which could be a molecular target for managing psychological stress-induced GI tract diseases.

Regional Diversities in Fibrogenesis Weighed as a Key Determinant for Atrial Arrhythmogenesis

Atrial fibrosis plays a key role in atrial myopathy, resulting in the genesis of atrial fibrillation (AF). The abnormal distribution of fibrotic tissue, electrical coupling, paracrine interactions, and biomechanical–electrical interactions have all been suggested as causes of fibrosis-related arrhythmogenesis. Moreover, the regional difference in fibrogenesis, specifically the left atrium (LA) exhibiting a higher arrhythmogenesis and level of fibrosis than the right atrium (RA) in AF, is a key contributor to atrial arrhythmogenesis. LA fibroblasts have greater profibrotic cellular activities than RA fibroblasts, but knowledge about the regional diversity of atrial regional fibrogenesis remains limited. This article provides a comprehensive review of research findings on the association between fibrogenesis and arrhythmogenesis from laboratory to clinical evidence and updates the current understanding of the potential mechanism underlying the difference in fibrogenesis between the LA and RA.

Heterogeneity affects the differentiation potential of dental follicle stem cells through the TGF-β signaling pathway

Adult mesenchymal stem cells play an important role in maintaining organ homeostasis owing to their unique ability to generate more specialized cell populations in a coordinated manner. Adult mesenchymal stem cells are heterogeneous, a feature that is essential for their functions. However, studies have not elucidated how heterogeneity of mesenchymal stem cells affects their differentiation capacity. The current study thus explored the heterogeneous Dental Follicle Stem Cells (DFSCs). A previous study by our research group reported that selecting sub-clones can cause artificial damage of the heterogeneous microenvironment of DFSCs. The finds showed a decrease in differentiation capacity of the three subclones, although the underlying mechanism was not elucidated. In this study, cells were harvested and prepared for gene expression microarray analysis. Sequence data was used in gene ontology and pathway enrichment analysis. The results showed that downregulation of the TGF-β signaling pathway was the main cause of changes in differentiation of sub-clones. Additional analyses revealed that the Hippo pathway, WNT pathway and signaling pathways regulating the pluripotency of stem cells were also implicated in these changes, through a cross talk with TGF-β signaling pathway through Bmp2, Bmp4, and Bambi. In vivo implantation experiments and osteogenic induction showed that differentiation capacity of DFSCs was significantly reduced in the sub-clones. In summary, the findings of the current study show that differentiation potential of DFSCs is correlated with the heterogeneous microenvironment and TGF-β signaling pathway significantly modulates these biological processes.

Botulinum toxin A promotes the transdifferentiation of primary keloid myofibroblasts into adipocyte-like cells

Keloid is a type of unusually raised scar. Botulinum toxin A (BTX-A) has a great application potential in keloids treatment. Here, we investigated the functional role of BTX-A in keloids. We separated keloid tissues and normal skin tissues from keloid patients and found that the expression of myofibroblast markers, α-SMA, Collagen I, and Collagen III was increased in the keloid tissues as compared with normal skin tissues. Keloid fibroblasts derived from keloid tissues were treated with TGF-β1 to induce the differentiation of fibroblasts into myofibroblasts. The keloid myofibroblasts displayed a significant up-regulation of α-SMA. BTX-A enhanced the expression of adipocyte markers, PPARγ and C/EBPα, and increased the accumulation of lipid droplets, and reduced the expression of α-SMA, Collagen I, and Collagen III in the keloid myofibroblasts. Moreover, BTX-A enhanced the expression of BMP4 and p-smad1/5/8. Noggin (BMP4 antagonist) treatment reversed BTX-A-mediated increase of PPARγ and C/EBPα expression and lipid droplets, and down-regulation of α-SMA, Collagen I, and Collagen III in primary keloid myofibroblasts. In conclusion, BTX-A promoted the transdifferentiation of primary keloid myofibroblasts into adipocyte-like cells, which may attribute to activate BMP4/Smad signalling pathway. Thus, this study provides new insights into the mechanism of BTX-A in keloid.

Mesenchymal stem cell conditioned medium attenuates oxidative stress injury in hepatocytes partly by regulating the miR-486-5p/PIM1 axis and the TGF-β/Smad pathway

This study investigated the role of microRNA (miRNA) miR-486-5p in oxidative stress injury in hepatocytes under the treatment of mesenchymal stem cell conditioned medium (MSC-CM). The oxidative stress injury in hepatocytes (L02) was induced by H₂O₂. Human umbilical cord blood MSC-CM (UCB-MSC-CM) was prepared. The effects of UCB-MSC-CM on the proliferation, apoptosis, and inflammatory response in L02 cells were detected by Cell Counting Kit-8 (CCK-8) assay, flow cytometry analysis, and enzyme-linked immunosorbent assay (ELISA). Subsequently, the target of miR-486-5p was predicted using bioinformatics analysis, and the possible signaling pathway addressed by miR-486-5p was explored using western blot. We found that miR-486-5p expression was elevated following oxidative stress injury and was reduced after UCB-MSC-CM treatment. UCB-MSC-CM protected L02 cells against H₂O₂-induced injury by downregulation of miR-486-5p. Proviral integration site for Moloney murine leukemia virus 1 (PIM1) was verified to be targeted by miR-486-5p. UCB-MSC-CM upregulated the expression of PIM1 reduced by H₂O₂ in L02 cells. Additionally, silencing PIM1 attenuated the protective effects of miR-486-5p downregulation against oxidative stress injury. We further demonstrated that UCB-MSC-CM inhibited the TGF-β/Smad signaling in H₂O_2-treated L02 cells by the miR-486-5p/PIM1 axis. Overall, UCB-MSC-CM attenuates oxidative stress injury in hepatocytes by downregulating miR-486-5p and upregulating PIM1, which may be related to the inhibition of TGF-β/Smad pathway.

The miR-130a-3p/TGF-βRII Axis Participates in Inhibiting the Differentiation of Fibroblasts Induced by TGF-β1

Pulmonary fibrosis (PF) is a chronic progressive interstitial lung disease that has a poor prognosis. Abnormal activation of transforming growth factor-β1 (TGF-β1) plays a crucial role in fibroblast differentiation. Mesenchymal stem cells (MSCs) are currently being considered for the treatment of PF, but the regulatory mechanisms are poorly understood. We co-cultured bone marrow-derived MSCs and mouse lung fibroblasts (MLg) in the presence of TGF-β1, and studied the protein/mRNA expression of fibrosis markers and related signaling pathways. The effects of miR-130a-3p and TGF-β receptor II (TGF-βRII) on the differentiation of MLg induced by TGF-β1 were studied using immunofluorescence assay, Western blot, and quantitative real-time PCR techniques, respectively. Our results showed that MSCs reversed the overexpression of fibrosis markers and TGF-β1/Smad signaling pathway proteins and mRNAs after TGF-β1 treatment and increased the level of miR-130a-3p. TGF-βRII was identified as a target of miR-130a-3p and was evaluated by dual-luciferase reporter assay. The miR-130a-3p/TGF-βRII axis could suppress the differentiation of lung fibroblasts via the TGF-β1/Smad signaling pathway, thereby reducing the process of PF.