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Chronic wounds can develop as a result of prolonged inflammation during the healing process, which can happen due to bacterial infection. Therefore, preventing infection and controlling inflammation can accelerate wound healing. Antimicrobial peptides have different protective properties in addition to antimicrobial activity. Some of these activities include the stimulation of cytokine or chemokine synthesis, the facilitation of chemotaxis and cell proliferation, the acceleration of cell proliferation, the induction of anti-inflammatory responses, and the promotion of wound repair. This study aimed to assess the wound healing potential of a novel in silico-designed antimicrobial peptide. Then, its anti-inflammatory activity was investigated by measuring the level of tumor necrosis factor-α (TNF-α) and transforming growth factor beta (TGF-β) as indicators of the wound healing process. In addition, the influence of the peptide on cell migration was evaluated by a scratch test on human dermal fibroblasts (HDF) and HaCaT cells as a human epidermal keratinocyte cell line. The results showed that our new peptide could act well in inhibiting TNF-α over-secretion while increasing the expression of TGF-β as an anti-inflammatory factor. This peptide showed a significant potential to stimulate HDF and HaCaT cell migration and proliferation. Therefore, using this peptide as an anti-inflammatory component of wound dressings may be promising. • A novel antimicrobial peptide was designed from Cathelicidine-2, named as mCHTL (131-140). • The mCHTL (131-140) could inhibit TNF-α over-secretion. • The mCHTL (131-140) could increase the TGF-β expression. • The mCHTL (131-140) could stimulate HDF and HaCaT cells migration and proliferation. [ABSTRACT FROM AUTHOR]

In skin aging, it has been hypothesized that aging fibroblasts accumulate within the epidermal basal layer, dermis, and subcutaneous fat, causing abnormal tissue remodeling and extracellular matrix dysfunction, thereby inducing an aging-related secretory phenotype (SASP). A new treatment for skin aging involves the specific elimination of senescent skin cells, especially fibroblasts within the dermis and keratinocytes in the basal layer. This requires the identification of specific protein markers of senescent cells, such as ribonucleoside-diphosphate reductase subunit M2 B (RRM2B), which is upregulated in various malignancies in response to DNA stress damage. However, the behavior and role of RRM2B in skin aging remain unclear. Therefore, we examined whether RRM2B functions as a senescence marker using a human dermal fibroblast model of aging. In a model of cellular senescence induced by replicative aging and exposure to ionizing radiation or UVB, RRM2B was upregulated at the gene and protein levels. This was correlated with decreased uptake of the senescence-associated β-galactosidase activity and proliferation marker bromodeoxyuridine. RRM2B upregulation was concurrent with the increased expression of SASP factor genes. Furthermore, using fluorescence flow cytometry, RRM2B-positive cells were recovered more frequently in the aging cell population. In aging human skin, RRM2B was also found to be more abundant in the dermis and epidermal basal layer than other proteins. Therefore, RRM2B may serve as a clinical marker to identify senescent skin cells. [ABSTRACT FROM AUTHOR]

The healing of human skin wounds is susceptible to perturbation caused by excessive mechanical stretching, resulting in enlarged scars, hypertrophic scars, or even keloids in predisposed individuals. Keloids are fibro‐proliferative scar tissues that extend beyond the initial wound boundary, consisting of the actively progressing periphery and the quiescent center. The stretch‐associated outgrowth and enhanced angiogenesis are two features of the periphery of keloids. However, which cell population is responsible for transducing the mechanical stimulation to the progression of keloids remains unclear. Herein, through integrative analysis of single‐cell RNA sequencing of keloids, we identified CD74+ fibroblasts, a previously unappreciated subset of fibroblasts with pro‐angiogenic and stretch‐induced proliferative capacities, as a key player in stretch‐induced progression of keloids. Immunostaining of keloid cryosections depicted a predominant distribution of CD74+ fibroblasts in the periphery, interacting with the vasculature. In vitro tube formation assays on purified CD74+ fibroblasts ascertained their pro‐angiogenic function. BrdU assays revealed that these cells proliferate upon stretching, through PIEZO1‐mediated calcium influx and the downstream ERK and AKT signaling. Collectively, our findings propose a model wherein CD74+ fibroblasts serve as pivotal drivers of stretch‐induced keloid progression, fueled by their proliferative and pro‐angiogenic activities. Targeting the attributes of CD74+ fibroblasts holds promise as a therapeutic strategy for the management of keloids. [ABSTRACT FROM AUTHOR]

Background: In mouse models of atherosclerosis, knockout of the PLA2G2A gene has been shown to reduce the volume of atherosclerotic plaques. Clinical trials have demonstrated the potential of using the sPLA2 inhibitor Varespladib in combination with statins to reduce lipid levels. However, this approach has not yielded the expected results in reducing the risk of cardiovascular events. Therefore, it is necessary to further investigate the mechanisms of PLA2G2A. Methods: Single-cell transcriptome data from two sets of carotid plaques, combined with clinical patient information. were used to describe the expression characteristics of PLA2G2A in carotid plaques at different stages. In order to explore the mechanisms of PLA2G2A, we conducted enrichment analysis, cell–cell communication analysis and single-cell regulatory network inference and clustering analyses. We validated the above findings at the cellular level. Results: Our findings indicate that PLA2G2A is primarily expressed in vascular fibroblasts and shows significant cell interactions with macrophages in the early-stage, especially in complement and inflammation-related pathways. We also found that serum sPLA2 levels have stronger diagnostic value in patients with mild carotid artery stenosis. Subsequent comparisons of single-cell transcriptomic data from early and late-stage carotid artery plaques corroborated these findings and predicted transcription factors that might regulate the progression of early carotid atherosclerosis (CA) and the expression of PLA2G2A. Conclusions: Our study discovered and validated that PLA2G2A is highly expressed by vascular fibroblasts and promotes plaque progression through the activation of macrophage complement and coagulation cascade pathways in the early-stage of CA. [ABSTRACT FROM AUTHOR]

Renal fibrosis is a common pathological feature of chronic kidney disease (CKD) with the proliferation and activation of myofibroblasts being definite effectors and drivers. Here, increased expression of Meis1 (myeloid ecotropic viral integration site 1) is observed, predominantly in the nucleus of the kidney of CKD patients and mice, and negatively correlates with serum creatinine. Fibroblast‐specific knock‐in of Meis1 inhibits myofibroblast activation and attenuates renal fibrosis and kidney dysfunction in CKD models. Overexpression of Meis1 in NRK‐49F cells suppresses the pro‐fibrotic response induced by transforming growth factor‐β1 but accelerates by its knockdown. Mechanistically, Meis1 targets protein tyrosine phosphatase receptor J (Ptprj) to block renal fibrosis by inhibiting the proliferation and activation of fibroblasts. Finally, a new activator of Ptprj is identified through computer‐aided virtual screening, which has the effect of alleviating renal fibrosis. Collectively, these results illustrate that the Meis1/Ptprj axis has therapeutic potential for clinically treating CKD. [ABSTRACT FROM AUTHOR]

There is documented sex disparity in cutaneous melanoma incidence and mortality, increasing disproportionately with age and in the male sex. However, the underlying mechanisms remain unclear. While biological sex differences and inherent immune response variability have been assessed in tumor cells, the role of the tumor-surrounding microenvironment, contextually in aging, has been overlooked. Here, we show that skin fibroblasts undergo age-mediated, sex-dependent changes in their proliferation, senescence, ROS levels, and stress response. We find that aged male fibroblasts selectively drive an invasive, therapy-resistant phenotype in melanoma cells and promote metastasis in aged male mice by increasing AXL expression. Intrinsic aging in male fibroblasts mediated by EZH2 decline increases BMP2 secretion, which in turn drives the slower-cycling, highly invasive, and therapy-resistant melanoma cell phenotype, characteristic of the aged male TME. Inhibition of BMP2 activity blocks the emergence of invasive phenotypes and sensitizes melanoma cells to BRAF/MEK inhibition. [Display omitted] • Skin fibroblasts show age- and sex-specific changes in proliferation and stress response • Male fibroblasts age faster due to elevated ROS levels • BMP2 is secreted in the aged male dermal microenvironment • BMP2 promotes slow-cycling, invasive, targeted therapy-resistant melanoma tumors Aging-driven and sex-dependent molecular changes in skin fibroblasts drive the emergence of invasive and therapy-resistant melanomas in male mice. [ABSTRACT FROM AUTHOR]

Background: Exosomes (Exos) are candidates for functional recovery and regeneration following sciatic nerve crushed (SNC) injury due to their composition which can accelerate tissue regeneration. Therefore, mouse embryonic fibroblast-derived exosomes were evaluated for their regenerative capacity in SNC injury. Methods and Results: In the study, 40 Balb/c males (20 ± 5 g) and two pregnant mice (for embryonic fibroblast tissue) were used and crushed injury was induced in the left sciatic nerve with an aneurysm clamp. Sciatic nerve model mice were randomly divided into 5 groups (n = 8; control, n = 8; sham, n = 8; SNC, n = 8; Mouse embryonic fibroblast exosome (mExo), n = 8; SNC + Mouse embryonic fibroblast exosome (SNC + mExo). Rotarod tests for motor functions and hot plate and von Frey tests for sensory functions were analyzed in the groups. Expression changes of exosome genes (RARRES1, NAGS, HOXA13, and MEIS1) immunohistochemical analysis of these gene proteins, and structural exosome NF-200 and S100 proteins were evaluated by confocal microscopy. Behavioral analyses showed that the damage in SNC was significant between groups on day14 and day28 (P < 0.05). In behavioral analyses, it was determined that motor functions and mechanical sensitivity lost in SNC were regained after mExo treatment. While expression of all genes was detected in MEF-derived exosomes, the high expression was MESI1 and the low expression was HOXA13. NF200, an indicator of axon number and neurofilament density, was found to decrease in SNC (P < 0.001) and increase after treatment, but not significantly. The decreased S100 protein levels in SNC and the increase detected after treatment were not significant. Conclusion: The expression of four mRNAs in mExos indicates that these genes may have an effect on regenerative processes after SNC injury. The regenerative process supported by tissue protein expressions demonstrates the therapeutic potential of mExo treatment. [ABSTRACT FROM AUTHOR]

Background: Idiopathic pulmonary fibrosis (IPF) is a chronic and lethal lung disorder for which effective treatments remain limited. Recent investigations revealed a potential link between altered glucose metabolism and the activation of fibroblasts, the key cells responsible for generating and depositing extracellular matrix proteins within the lung interstitium during IPF development. Method: In this study, we aimed to investigate the potential therapeutic impact of albendazole on fibroblast to myofibroblast transition in IPF. We assess albendazole's effectiveness in attenuating the activation of fibroblasts. We focused on elucidating the mechanism underlying albendazole's impact on TGF-β1-induced aerobic glycolysis in both lung tissues and fibroblasts obtained from patients with IPF and other lung fibrosis types. Furthermore, the antifibrotic effects of oral administration of albendazole were investigated in mouse models of pulmonary fibrosis induced by BLM or SiO2. Human precision-cut lung slices were employed to evaluate the impact of albendazole following TGF-β1 stimulation. Result: In this work, we demonstrated that albendazole, a first-line broad-spectrum anthelmintic drug, effectively attenuated fibroblast to myofibroblast transition through alleviating TGF-β1-induced aerobic glycolysis dependent on the LRRN3/PFKFB3 signaling pathway. Additionally, LRRN3 expression was downregulated in both lung tissues and fibroblasts from patients with IPF and other types of lung fibrosis. Importantly, the levels of LRRN3 correlated with the progression of the disease. Notably, oral administration of albendazole exerted potent antifibrotic effects in mouse models of pulmonary fibrosis induced by BLM or SiO2, and in human precision-cut lung slices after TGF-β1 stimulation, as evidenced by improvements in lung morphology, reduced myofibroblast formation, and downregulation of α-SMA, collagen type 1 and Fibronectin expression in the lungs. Conclusion: Our study implies that albendazole can act as a potent agonist of LRRN3 during fibroblast to myofibroblast differentiation and its oral administration shows potential as a viable therapeutic approach for managing IPF. [ABSTRACT FROM AUTHOR]

Ubiquitin C‐terminal hydrolase L1 (UCHL1) plays vital roles in cell proliferation, angiogenesis, inflammation and oxidative stress. Nevertheless, it is unclear whether UCHL1 could regulate the biologic behaviour of cells and ultimately influences wound healing. We aim to illustrate the roles and the underlying mechanism of UCHL1 in cutaneous wound healing. Murine full‐thickness excisional wound model was utilised to study the effects of UCHL1 on wound healing through topical administration of the UCHL1 inhibitor LDN57444, followed by assessment of wound areas and histological alterations. Subsequently, ethynyldeoxyuridine, scratch and transwell assays were performed to examine fibroblast migration and proliferation. The extracellular matrix (ECM)‐related genes expression and transforming growth factor‐β (TGF‐β)/Smad signalling pathways activation were investigated by immuno‐fluorescent staining, Western blots and quantitative reverse transcription polymerase chain reaction. We identified elevated UCHL1 expression in non‐healing wound tissues. The UCHL1 expression displayed a dynamic change and reached a peak on Day‐7 post‐wounding during the healing process in mice. Cutaneous administration of LDN57444 promoted wound healing by facilitating collagen deposition, myofibroblast activation and angiogenesis. In vitro experiments demonstrated that UCHL1 concentration dependently inhibited migration, ECM synthesis and activation of human dermal fibroblasts, which was mechanistically related to downregulation of TGF‐β/Smad signalling. Furthermore, these effects could be reversed by TGF‐β inhibitor SB431542. Our findings reveal that UCHL1 is a negative regulator of cutaneous wound healing and considered as a novel prospective therapeutic target for effective wound healing. [ABSTRACT FROM AUTHOR]

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal fibrotic lung disease. While recent studies have suggested the potential efficacy of tyrosine kinase inhibitors in managing IPF, masitinib, a clinically used tyrosine kinase inhibitor, has not yet been investigated for its efficacy in fibrotic lung diseases. In a previous study on an in vitro neurodegenerative model, we demonstrated the synergistic antitoxic and antioxidant effects of masitinib combined with cromolyn sodium, an FDA‐approved mast cell stabilizer. This study aims to investigate the anti‐fibrotic and antioxidant effects of the masitinib‐cromolyn sodium combination in an in vitro model of pulmonary fibrosis. Fibroblast cell cultures treated with bleomycin and/or hydrogen peroxide (H2O2) were subjected to masitinib and/or cromolyn sodium, followed by assessments of cell viability, morphological and apoptotic nuclear changes, triple‐immunofluorescence labeling, and total oxidant/antioxidant capacities, besides ratio of Bax and Bcl‐2 mRNA expressions as an indication of apoptosis. The combined treatment of masitinib and cromolyn sodium effectively prevented the fibroblast myofibroblast transition, a hallmark of fibrosis, and significantly reduced bleomycin / H2O2‐induced apoptosis and oxidative stress. This study is the first to demonstrate the additive anti‐fibrotic, cell‐protective, and antioxidant effects of the masitinib‐cromolyn sodium combination in an in vitro fibrosis model, suggesting its potential as an innovative therapeutic approach for pulmonary fibrosis. Combination therapy may be more advantageous in that both drugs could be administered in lower doses, exerting less side effects, and at the same time providing diverse mechanisms of action simultaneously. [ABSTRACT FROM AUTHOR]

Communication between the different layers of the cornea (epithelium and stroma) is a complex, yet crucial element in the corneal healing process. Upon corneal injury, it has been reported that the bi-directional cross talk between the epithelium and stroma via the vesicular secretome, namely, extracellular vesicles (EVs), can lead to accelerated wound closure upon injury. However, the distinct protein markers of EVs derived from human corneal epithelial (HCE) cells, keratocytes (HCKs), fibroblasts (HCFs), and myofibroblasts (HCMs) remain poorly understood. All EVs were enriched for CD81 and showed increased expression levels of ITGAV and FN1 in HCM-EVs compared to HCE- and HCF-EVs. All EVs were negative for GM130 and showed minimal differences in biophysical properties (particle concentration, median particle size, and zeta potential). At the proteomic level, we show that HCM-EVs are enriched with proteins associated with fibrosis pathways, such as COL6A1, COL6A2, MMP1, MMP2, TIMP1, and TIMP2, compared to HCE-, HCK-, and HCF-EVs. Interestingly, HCE-EVs express proteins involved with the EIF-2 signaling pathway (stress-induced signals to regulate mRNA translation), such as RPS21, RALB, EIF3H, RALA, and others, compared to HCK-, HCF-, and HCM-EVs. In this study, we isolated EVs from cell-conditioned media from HCE, HCKs, HCFs, and HCMs and characterized their biophysical and protein composition by Western blot, nanoparticle tracking analysis, and proteomics. This study supports the view that EVs from the corneal epithelium and stroma have a distinct molecular composition and may provide novel protein markers to distinguish the difference between HCE-, HCK-, HCF-, and HCM-EVs. [ABSTRACT FROM AUTHOR]

Background: Myocardial infarction (MI) induces complex transcriptional changes across diverse cardiac cell types. Single-cell RNA sequencing (scRNA-seq) provides an unparalleled ability to discern cellular diversity during infarction, yet the veracity of these discoveries necessitates confirmation. This investigation sought to elucidate MI mechanisms by integrating scRNA-seq and bulk RNA-seq data. Methods: Publicly available scRNA-seq (GSE136088) and bulk RNA-seq (GSE153485) data from mice MI models were analyzed. Cell types were annotated, and differential expression analysis conducted. Bulk RNA-seq underwent quality control, principal component analysis, and differential expression analysis. Results: In scRNA-seq data, the comparison between MI and sham groups unveiled a reduction in endothelial cell populations, but macrophages and monocytes increased. Within fibroblast subgroups, three distinct categories were discerned, with two exhibiting upregulation in MI. Notably, endothelial cells exhibited an elevated expression of genes associated with apoptosis and ferroptosis. In bulk RNA-seq analysis, distinct patterns emerged when comparing MI and sham groups. Specifically, six genes linked to endothelial ferroptosis exhibited heightened expression in MI group, thereby corroborating the scRNA-seq findings. Moreover, the examination of isolated cardiac macrophages from mice MI model revealed increased expression of Spp1, Col1a2, Col3a1, Ctsd, and Lgals3 compared to sham group, thus substantiating the dysregulation of macrophage apoptosis-related proteins following MI. Conclusion: MI altered the transcriptomic landscapes of cardiac cells with increased expression of apoptotic genes. Moreover, the upregulation of macrophage apoptosis marker was confirmed within MI models. The presence of endothelial cell depletion and ferroptosis in MI has been demonstrated. [ABSTRACT FROM AUTHOR]

Background and objective: Adipose-derived mesenchymal stem cells (ADSCs) can accelerate wound healing, reduce scar formation, and inhibit hypertrophic scar (HTS). ADSCs can secrete a large amount of CCL5, and CCL5 has been proved to be pro-inflammatory and pro-fibrotic. CXCL12 (SDF-1) is a key chemokine that promotes stem cell migration and survival. Therefore, this study selected normal skin and HTS conditioned medium to simulate different microenvironments, and analyzed the effects of different microenvironments on the expression of CCL5 and CXCL12 in human ADSCs (hADSCs). Materials and methods: hADSCs with silenced expression of CCL5 and CXCL12 were co-cultured with hypertrophic scar fibroblasts to verify the effects of CCL5 and CXCL12 in hADSCs on the proliferation ability of hypertrophic scar fibroblasts. A mouse model of hypertrophic scar was established to further confirm the effect of CCL5 and CXCL12 in hADSCs on hypertrophic scar formation. Results: CCL5 level was found to be significantly high in hADSCs cultured in HTS conditioned medium. CXCL12 in HTS group was prominently lowly expressed compared with the normal group. Inhibition of CCL5 in hADSCs enhanced the effects of untreated hADSCs on proliferation of HTS fibroblasts while CXCL12 knockdown exerted the opposite function. Inhibition of CCL5 in hADSCs increased the percentage of HTS fibroblasts in the G0/G1 phase while down-regulation of CXCL12 decreased those. Meanwhile, the down-regulated levels of fibroblast markers including collagen I, collagen III, and α-SMA induced by CCL5 knockdown were significantly up-regulated by CXCL12 inhibition. hADSCs alleviate the HTS of mice through CCL5 and CXCL12. Conclusion: In summary, our results demonstrated that hADSCs efficiently cured HTS by suppressing proliferation of HTS fibroblasts, which may be related to the inhibition of CXCL12 and elevation of CCL5 in hADSCs, suggesting that hADSCs may provide an alternative therapeutic approach for the treatment of HTS. [ABSTRACT FROM AUTHOR]

Background: Keloids are a common fibrotic disease of the skin, with the pathological hallmark of excessive extracellular matrix synthesis due to abnormal fibroblast activity. Since keloids clinically arise in areas of high mechanical tension, the mechanotransductory pathway may be attributed to its pathogenesis. We aimed to establish a preclinical platform to elucidate the underlying mechanism of keloid development and its clinical persistence. Methods: We fabricated a mechanically stretchable polydimethylsiloxane cell culture platform; with its mimicry of the in vivo cyclic stretch of skeletal muscles, cells showed higher proliferation compared with conventional modalities. Results: In response to mechanical strain, TGF-β and type 1 collagen showed significant increases, suggesting possible TGF-β/Smad pathway activation via mechanical stimulation. Protein candidates selected by proteomic analysis were evaluated, indicating that key molecules involved in cell signaling and oxidative stress were significantly altered. Additionally, the cytoskeletal network of keloid fibroblasts showed increased expression of its components after periodic mechanical stimulation. Conclusions: Herein, we demonstrated and validated the existing body of knowledge regarding profibrotic mechanotransduction signaling pathways in keloid fibroblasts. Cyclic stretch, as a driving force, could help to decipher the tension-mediated biomechanical processes, leading to the development of optimized therapeutic targets. [ABSTRACT FROM AUTHOR]

As one of the key components of the immune system, mast cells are well known for their role in allergic reactions. However, they are also involved in inflammatory and fibrotic processes. Mast cells participate in all the stages of acute inflammatory responses, playing an immunomodulatory role in both innate and adaptive immunity. Mast cell-derived histamine, TNF-α, and IL-6 contribute to the inflammatory processes, while IL-10 mediates the suppression of inflammation. Crosstalk between mast cells and other immune cells is also involved in the development of inflammation. The cell-cell adhesion of mast cells and fibroblasts is crucial for fibrosis. Mast cell mediators, including cytokines and proteases, play contradictory roles in the fibrotic process. Here, we review the double-edged role of mast cells in inflammation and fibrosis. [ABSTRACT FROM AUTHOR]

Background: Cryopreservation is a crucial procedure for safeguarding cells or other biological constructs, showcasing considerable potential for applications in tissue engineering and regenerative medicine. Aims: This study aimed to evaluate the effectiveness of different cryopreservation conditions on human cells viability. Methods: A set of cryopreserved data from Department of Tissue Engineering and Regenerative Medicine (DTERM) cell bank were analyse for cells attachment after 24 h being revived. The revived cells were analysed based on different cryopreservation conditions which includes cell types (skin keratinocytes and fibroblasts, respiratory epithelial, bone marrow mesenchymal stem cell (MSC); cryo mediums (FBS + 10% DMSO; commercial medium); storage durations (0 to > 24 months) and locations (tank 1–2; box 1–5), and revival methods (direct; indirect methods). Human dermal fibroblasts (HDF) were then cultured, cryopreserved in different cryo mediums (HPL + 10% DMSO; FBS + 10% DMSO; Cryostor) and stored for 1 and 3 months. The HDFs were revived using either direct or indirect method and cell number, viability and protein expression analysis were compared. Results: In the analysis cell cryopreserved data; fibroblast cells; FBS + 10% DMSO cryo medium; storage duration of 0–6 months; direct cell revival; storage in vapor phase of cryo tank; had the highest number of vials with optimal cell attachment after 24 h revived. HDFs cryopreserved in FBS + 10% DMSO for 1 and 3 months with both revival methods, showed optimal live cell numbers and viability above 80%, higher than other cryo medium groups. Morphologically, the fibroblasts were able to retain their phenotype with positive expression of Ki67 and Col-1. HDFs cryopreserved in FBS + 10% DMSO at 3 months showed significantly higher expression of Ki67 (97.3% ± 4.62) with the indirect revival method, while Col-1 expression (100%) was significantly higher at both 1 and 3 months compared to other groups. Conclusion: In conclusion, fibroblasts were able to retain their characteristics after various cryopreservation conditions with a slight decrease in viability that may be due to the thermal-cycling effect. However, further investigation on the longer cryopreservation periods should be conducted for other types of cells and cryo mediums to achieve optimal cryopreservation outcomes. Highlights: Cryopreservation optimizes cell recovery, viability for tissue engineering. Fibroblasts maintain phenotype in FBS + 10% DMSO, but longer periods need scrutiny. [ABSTRACT FROM AUTHOR]

Heparan sulfate proteoglycans (HSPGs) regulate a wide range of biological activities in both physiological and pathological conditions. Altered expression or deregulated function of HSPGs and their heparan sulfate (HS) chains significantly contribute to carcinogenesis as well and crucially depends on the functioning of the complex system of HS biosynthetic/modifying enzymes termed as "GAGosome". Here, we aimed at investigating the expression profile of the system in a cell culture model of stroma-epithelial crosstalk and searching for transcription factors potentially related to the regulation of expression of the genes involved. Coculture of BjTERT-fibroblasts with normal PNT2 human prostate epithelial cells resulted in significant downregulation (2-4-fold) of transcriptional activity of HS metabolism-involved genes (EXT1/2, NDST1/2, GLCE, HS2ST1, HS3ST1/2, HS6ST1/2, SULF1/2, HPSE) in both cell types, whereas coculture with prostate cancer cells (LNCaP, PC3, DU145) demonstrated no significant interchanges. Human Transcription Factor RT2 Profiler PCR array and manual RT-PCR verification supposed FOS, MYC, E2F, SRF, NR3C1 as potential candidates for regulation and/or coordination of HS biosynthesis. Taken together, transcriptional activity of HS biosynthetic system in normal fibroblasts and prostate epithelial cells during their coculture might be controlled by their intercellular communication, reflecting of adaptation of these cells to each other. The regulation is attenuated or abrogated if normal fibroblasts interact with prostate cancer cells making the cancer cells independent of the limiting effects of fibroblasts, thus contributing to possibility of unlimited growth and progression. Overall, these data demonstrate an ability of cell-cell interactions to affect transcriptional activity of HS biosynthesis-involved genes. [ABSTRACT FROM AUTHOR]

Skin aging has been associated with the onset of various skin issues, and recent studies have identified an increase in Cdc42 activity in naturally aging mice. While previous literature has suggested that CASIN, a specific inhibitor of Cdc42 activity, may possess anti‐aging properties, its specific effects on the epidermis and dermis, as well as the underlying mechanisms in naturally aging mice, remain unclear. Our study revealed that CASIN demonstrated the ability to increase epidermal and dermal thickness, enhance dermal‐epidermal junction, and stimulate collagen and elastic fiber synthesis in 9‐, 15‐, and 24‐month‐old C57BL/6 mice in vivo. Moreover, CASIN was found to enhance the proliferation, differentiation, and colony formation and restore the cytoskeletal morphology of primary keratinocytes in naturally aging skin in vitro. Furthermore, the anti‐aging properties of CASIN on primary fibroblasts in aging mice were mediated by the ribosomal protein RPL4 using proteomic sequencing, influencing collagen synthesis and cytoskeletal morphology both in vitro and in vivo. Meanwhile, both subcutaneous injection and topical application exhibited anti‐aging effects for a duration of 21 days. Additionally, CASIN exhibited anti‐inflammatory properties, while reduced expression of RPL4 was associated with increased inflammation in the skin of naturally aging mice. Taken together, our results unveil a novel function of RPL4 in skin aging, providing a foundational basis for future investigations into ribosomal proteins. And CASIN shows promise as a potential anti‐aging agent for naturally aging mouse skin, suggesting potential applications in the field. [ABSTRACT FROM AUTHOR]

Cutaneous squamous cell carcinoma (cSCC) is the most common metastatic skin cancer and the metastatic disease is associated with poor prognosis. Cancer‐associated fibroblasts (CAFs) promote progression of cancer, but their role in cSCC is largely unknown. We examined the potential of CAF markers in the assessment of metastasis risk and prognosis of primary cSCC. We utilized multiplexed fluorescence immunohistochemistry for profiling CAF landscape in metastatic and non‐metastatic primary human cSCCs, in metastases, and in premalignant epidermal lesions. Quantitative high‐resolution image analysis was performed with two separate panels of antibodies for CAF markers and results were correlated with clinical and histopathological parameters including disease‐specific mortality. Increased stromal expression of fibroblast activation protein (FAP), α‐smooth muscle actin, and secreted protein acidic and rich in cysteine (SPARC) were associated with progression to invasive cSCC. Elevation of FAP and platelet‐derived growth factor receptor‐β (PDGFRβ) expression was associated with metastasis risk of primary cSCCs. High expression of PDGFRβ and periostin correlated with poor prognosis. Multimarker combination defined CAF subset, PDGFRα−/PDGFRβ+/FAP+, was associated with invasion and metastasis, and independently predicted poor disease‐specific survival. These results identify high PDGFRβ expression alone and multimarker combination PDGFRα−/PDGFRβ+/FAP+ by CAFs as potential biomarkers for risk of metastasis and poor prognosis. [ABSTRACT FROM AUTHOR]

Background: The tumor microenvironment (TME) provides a region for intricate interactions within or between immune and non-immune cells. We aimed to reveal the tissue architecture and comprehensive landscape of cells within the TME of colorectal cancer (CRC). Methods: Fresh frozen invasive adenocarcinoma of the large intestine tissue from 10× Genomics Datasets was obtained from BioIVT Asterand. The integration of microarray-based spatial transcriptomics (ST) and RNA sequencing (RNA-seq) was applied to characterize gene expression and cell landscape within the TME of CRC tissue architecture. Multiple R packages and deconvolution algorithms including MCPcounter, XCELL, EPIC, and ESTIMATE methods were performed for further immune distribution analysis. Results: The subpopulations of immune and non-immune cells within the TME of the CRC tissue architecture were appropriately annotated. According to ST and RNA-seq analyses, a heterogeneous spatial atlas of gene distribution and cell landscape was comprehensively characterized. We distinguished between the cancer and stromal regions of CRC tissues. As expected, epithelial cells were located in the cancerous region, whereas fibroblasts were mainly located in the stroma. In addition, the fibroblasts were further subdivided into two subgroups (F1 and F2) according to the differentially expressed genes (DEGs), which were mainly enriched in pathways including hallmark-oxidative-phosphorylation, hallmark-e2f-targets and hallmark-unfolded-protein-response. Furthermore, the top 5 DEGs, SPP1, CXCL10, APOE, APOC1, and LYZ, were found to be closely related to immunoregulation of the TME, methylation, and survival of CRC patients. Conclusions: This study characterized the heterogeneous spatial landscape of various cell subtypes within the TME of the tissue architecture. The TME-related roles of fibroblast subsets addressed the potential crosstalk among diverse cells. [ABSTRACT FROM AUTHOR]

Fibrosis is an abnormal tissue healing process characterized by the excessive accumulation of ECM components, such as COL I and COL III, in response to tissue injury or chronic inflammation. Recent advances in epitranscriptomics have underscored the importance of m6A modification in fibrosis. m6A, the most prevalent modification in eukaryotic RNA, is catalyzed by methyltransferases (e.g., METTL3), removed by demethylases (e.g., FTO), and recognized by reader proteins (e.g., YTHDF1/2). These modifications are crucial in regulating collagen metabolism and associated diseases. Understanding the role of m6A modification in fibrosis and other collagen-related conditions holds promise for developing targeted therapies. This review highlights the latest progress in this area. [ABSTRACT FROM AUTHOR]

Background: Macrophage-based cell therapy is promising in solid tumors, but the efficient acquisition of macrophages remains a challenge. Induced pluripotent stem cell (iPSC)-induced macrophages are a valuable source, but time-consuming and costly. The application of reprogramming technologies allows for the generation of macrophages from somatic cells, thereby facilitating the advancement of cell-based therapies for numerous malignant diseases. Methods: The composition of CD45+ myeloid-like cell complex (MCC) and induced macrophage (iMac) were analyzed by flow cytometry and single-cell RNA sequencing. The engraftment capacity of CD45+ MCC was evaluated by two transplantation assays. Regulation of c-Myc on MafB was evaluated by ChIP-qPCR and promoter reporter and dual luciferase assays. The phenotype and phagocytosis of iMac were explored by flow cytometry and immunofluorescence. Leukemia, breast cancer, and patient-derived tumor xenograft models were used to explore the anti-tumor function of iMac. Results: Here we report on the establishment of a novel methodology allowing for reprogramming fibroblasts into functional macrophages with phagocytic activity by c-Myc overexpression. Fibroblasts with ectopic expression of c-Myc in iPSC medium rapidly generated CD45+ MCC intermediates with engraftment capacity as well as the repopulation of distinct hematopoietic compartments. MCC intermediates were stably maintained in iPSC medium and continuously generated functional and highly pure iMac just by M-CSF cytokine stimulation. Single-cell transcriptomic analysis of MCC intermediates revealed that c-Myc up-regulated the expression of MafB, a major regulator of macrophage differentiation, to promote macrophage differentiation. Characterization of the iMac activity showed NF-κB signaling activation and a pro-inflammatory phenotype. iMac cells displayed significantly increased in vivo persistence and inhibition of tumor progression in leukemia, breast cancer, and patient-derived tumor xenograft models. Conclusions: Our findings demonstrate that c-Myc alone is enough to reprogram fibroblasts into functional macrophages, supporting that c-Myc reprogramming strategy of fibroblasts can help circumvent long-standing obstacles to gaining "off-the-shelf" macrophages for anti-cancer immunotherapy. [ABSTRACT FROM AUTHOR]

Cellular senescence is a diverse phenotype characterised by permanent cell cycle arrest and an associated secretory phenotype (SASP) which includes inflammatory cytokines. Typically, senescent cells are removed by the immune system, but this process becomes dysregulated with age causing senescent cells to accumulate and induce chronic inflammatory signalling. Identifying senescent cells is challenging due to senescence phenotype heterogeneity, and senotherapy often requires a combinatorial approach. Here we systematically collected 119 transcriptomic datasets related to human fibroblasts, forming an online database describing the relevant variables for each study allowing users to filter for variables and genes of interest. Our own analysis of the database identified 28 genes significantly up-or downregulated across four senescence types (DNA damage induced senescence (DDIS), oncogene induced senescence (OIS), replicative senescence, and bystander induced senescence) compared to proliferating controls. We also found gene expression patterns of conventional senescence markers were highly specific and reliable for different senescence inducers, cell lines, and timepoints. Our comprehensive data supported several observations made in existing studies using single datasets, including stronger p53 signalling in DDIS compared to OIS. However, contrary to some early observations, both p16 and p21 mRNA levels rise quickly, depending on senescence type, and persist for at least 8-11 days. Additionally, little evidence was found to support an initial TGFβ-centric SASP. To support our transcriptomic analysis, we computationally modelled temporal protein changes of select core senescence proteins during DDIS and OIS, as well as perform knockdown interventions. We conclude that while universal biomarkers of senescence are difficult to identify, conventional senescence markers follow predictable profiles and construction of a framework for studying senescence could lead to more reproducible data and understanding of senescence heterogeneity. [ABSTRACT FROM AUTHOR]

Background/Aims: Gastric cancer (GC) ranks among the prevalent types of cancer, and its progression is influenced by the tumor microenvironment (TME). A comprehensive comprehension of the TME associated with GC has the potential to unveil therapeutic targets of significance. Methods: The complexity and heterogeneity of TME interactions were revealed through our investigation using an integrated analysis of single-cell and bulk-tissue sequencing data. Results: We constructed a single-cell transcriptomic atlas of 150,913 cells isolated from GC patients. Our analysis revealed the intricate nature and heterogeneity of the GC TME and the metabolic properties of major cell types. Furthermore, two cell subtypes, LOX+ Fibroblasts and M2 Macrophages, were enriched in tumor tissue and related to the outcome of GC patients. In addition, LOX+ Fibroblasts were significantly associated with M2 macrophages. immunofluorescence double labeling indicated LOX+ Fibroblasts and M2 Macrophages were tightly localized in GC tissue. The two cell subpopulations strongly interacted in a hypoxic microenvironment, yielding an immunosuppressive phenotype. Our findings further suggest that LOX+ Fibroblasts may act as a trigger for inducing the differentiation of monocytes into M2 Macrophages via the IL6-IL6R signaling pathway. Conclusions: Our study revealed the intricate and interdependent communication network between the fibroblast and macrophage subpopulations, which could offer valuable insights for targeted manipulation of the tumor microenvironment. [ABSTRACT FROM AUTHOR]

BACKGROUND: Heterotopic ossification of skeletal muscle is a clinically serious complication. For heterotopic ossification of skeletal muscles, the cells involved in the process of heterotopic ossification remain unclear. OBJECTIVE: To investigate the involvement of myocytes, fascia cells, and endothelial cells in the process of heterotopic ossification in skeletal muscle and to observe the cell origin of heterotopic ossification in skeletal muscle induced by bone morphogenetic protein 4. METHODS: Both C2C12 cells and the myotubes formed by the C2C12 cells in the induction medium were cultured, and 500 ng/mL bone morphogenetic protein 4 was added to the medium respectively, and whether the C2C12 cells and myotubes continued to proliferate within 10 days under the treatment were observed under a microscope. Myogenic cells (L6, derived from rats) and fibroblast-derived cells (derived from human) were co-cultured. After treatment with 500 ng/mL bone morphogenetic protein 4 and 10 ng/mL transforming growth factor-β, osteogenic and chondrogenic differentiation potential within 21 days were observed using Safranine O staining and Alcian blue staining. Using transgenic animal FVB/N-TgN (TIE2-LacZ) 182Sato mice, 15 μL of adeno-associated virus-bone morphogenetic protein 4 (5 × 1010 PFU/mL) were implanted in the thigh muscle space of genetic mice for 10 and 14 days. X-gal staining was used to observe the formation of new blood vessel endothelium in the differentiated bone. RESULTS AND CONCLUSION: (1) Bone morphogenetic protein 4 caused myotube breakdown and increased C2C12 cell proliferation. Compared with other groups, the pure fibroblast-derived cell group had a higher area of positive alcian blue and safarin O staining (P < 0.05) and a lower area of alkaline phosphatase staining (P < 0.05), while the pure L6 group had a bigger area of alkaline phosphatase staining (P < 0.05) but a smaller area of positive alcian blue and safarin O staining (P < 0.05). (2) Transplantation of adeno-associated virus-bone morphogenetic protein 4-adsorbed gelatin sponge into FVB/N-TgN (TIE2-LacZ)182Sato mice resulted in heterotopic ossification. (3) X-gal staining results demonstrated that there was no obvious staining in chondrocytes and differentiated bones and Tie2+ endothelial cells did not participate in the formation of the alienated bone. (4) These findings verify that fibroblasts are the primary source of osteoblasts during the adeno-associated virus-bone morphogenetic protein 4-induced ectopic endochondral ossification in skeletal muscle, but myogenic cells are the main source of osteoblasts. Tie2+ endothelial cells might not be the cell source for cartilage and bone. [ABSTRACT FROM AUTHOR]

Skin wound healing is a well‐coordinated process in which various cells and factors participate, during which fibroblast exhibits a critical role by exerting its multiple activities, including proliferation, migration, invasion, and differentiation. Previous studies have identified that fibromodulin (FMOD) could enhance dermal wound healing by promoting skin fibroblast activities, but little is known about its upstream regulator. We occasionally found that FMOD expression was downregulated in skin fibroblast by transforming growth factor‐β1 treatment. It was hypothesized that microRNAs (miRNA) in skin fibroblast could downregulate FMOD production and blocking them would increase FMOD expression, as well as promote skin wound healing. Here, by utilizing combined analysis of miRNA microarray from the Gene Expression Omnibus database and miRNA targets prediction, we successfully identified a miRNA, termed miR‐494‐3p, could regulate FMOD production in human skin fibroblast (BJ fibroblast). The functional analysis revealed that miR‐494‐3p mimics could inhibit BJ fibroblast migration and invasion but not proliferation and differentiation, while miR‐494‐3p inhibition markedly promotes migration, invasion, and differentiation of BJ fibroblast. Moreover, we established FMOD overexpression (OE) and knockout BJ fibroblast. We found that FMOD OE could rescue the inhibitory effects of miR‐494‐3p mimics on the migration and invasion of BJ fibroblast. In contrast, the miR‐494‐3p inhibitor transfection could not enhance migration, invasion, and differentiation of FMOD KO BJ fibroblast. Together, our results suggest that miR‐494‐3p may be a potential target for skin wound management via regulating FMOD production. [ABSTRACT FROM AUTHOR]

Chitosan (CHT) and propolis (P) are natural materials with antiseptic, anti-inflammatory, antimicrobial, and mucoadhesive properties with many applications in orthopaedia dentistry. The objective of this study was to develop a low molecular weight (LMW) and medium molecular weight (MMW) chitosan polymeric system with propolis at different concentrations (0.31%, 0.62%, 1.25%, 2.5%, and 5%) and to evaluate the effect in terms of their cell interaction with dental pulp fibroblasts. FTIR spectra of both molecular weights CHT's films with propolis show increased transmittance bands at 1730–1720 cm−1 and 1460 cm−1, indicating the presence of propolis ethanolic extract in the organic matrix. Contact angles test to determine hydrophobicity CHT films functionalized with propolis exhibit a more hydrophobic surface as propolis concentration increases. Cytotoxicity showed synergy between chitosan and propolis; the highest proliferation was observed in LMW CHT with 0.31% of propolis. Membranes made with CHT of both molecular weights plus propolis in an inflammatory stage (cells previously treated with LPS) can inhibit the expression of NF-k-B, MAPK, and VEGF. A polymeric system based on chitosan/ethanolic extract propolis could be a future alternative treatment for oral ulcers. [ABSTRACT FROM AUTHOR]

Ehlers–Danlos syndromes (EDS) are a group of multisystemic conditions that share soft and hyperextensible skin, abnormal wound healing, easy bruising, joint hypermobility, and chronic pain, with variable involvement of cardiovascular, musculoskeletal, and ocular systems. Alterations in collagen fibril morphology and organization are a unifying feature in all EDS types, despite a diverse range of underlying disease genes and molecular defects. A change in integrin receptors is found on the surface of dermal fibroblasts in most EDS types. Emerging insights from transcriptome profiling studies highlight a role for disturbed intracellular signaling pathways in some EDS types, such as the unfolded protein response (UPR) and impaired transforming growth factor β (TGFβ) signaling. The complete range of molecular mechanisms contributing to the pleotropic phenotype and the connection between different EDS types are incompletely understood. The Ehlers–Danlos syndromes (EDS) are a group of rare heritable connective tissue disorders, common hallmarks of which are skin hyperextensibility, joint hypermobility, and generalized connective tissue fragility. Currently, 13 EDS types are recognized, caused by defects in 20 genes which consequently alter biosynthesis, organization, and/or supramolecular assembly of collagen fibrils in the extracellular matrix (ECM). Molecular analyses on patient samples (mostly dermal fibroblast cultures), combined with studies on animal models, have highlighted that part of EDS pathogenesis can be attributed to impaired cellular dynamics. Although our understanding of the full extent of (extra)cellular consequences is still limited, this narrative review aims to provide a comprehensive overview of our current knowledge on the extracellular, pericellular, and intracellular alterations implicated in EDS pathogenesis. The Ehlers–Danlos syndromes (EDs) are a group of rare heritable connective tissue disorders, common hallmarks of which are skin hyperextensibility, joint hypermobility, and generalized connective tissue fragility. Currently, 13 EDS types are recognized, caused by defects in 20 genes which consequently alter biosynthesis, organization, and/or supramolecular assembly of collagen fibrils in the extracellular matrix (ECM). Molecular analyses on patient samples (mostly dermal fibroblast cultures), combined with studies on animal models, have highlighted that part of EDS pathogenesis can be attributed to impaired cellular dynamics. Although our understanding of the full extent of (extra)cellular consequences is still limited, this narrative review aims to provide a comprehensive overview of our current knowledge on the extracellular, pericellular, and intracellular alterations implicated in EDS pathogenesis. [ABSTRACT FROM AUTHOR]

Purpose: Fibroblast activation protein (FAP)-inhibitor (FAPI)-PET tracers allow imaging of the FAP-expressing cancer associated fibroblasts (CAF) and also the normal activated fibroblasts (NAF) involved in inflammation/fibrosis that may be present after invasive medical interventions. We evaluated [68Ga]Ga-FAPI-46 uptake patterns post-medical/invasive non-systemic interventions. Methods: This single-center retrospective analysis was conducted in 79 consecutive patients who underwent [68Ga]Ga-FAPI-46 PET/CT. Investigators reviewed prior patient medical/invasive interventions (surgery, endoscopy, biopsy, radiotherapy, foreign body placement (FBP) defined as implanted medical/surgical material present at time of scan) and characterized the anatomically corresponding FAPI uptake intensity both visually (positive if above surrounding background) and quantitatively (SUVmax). Interventions with missing data/images or confounders of [68Ga]Ga-FAPI-46 uptake (partial volume effect, other cause of increased uptake) were excluded. Available correlative FDG, DOTATATE and PSMA PET/CTs were analyzed when available. Results: 163 medical/invasive interventions (mostly surgeries (49%), endoscopies (18%) and non-surgical biopsies (10%)) in 60 subjects were included for analysis. 43/163 (26%) involved FBP. FAPI uptake occurred in 24/163 (15%) of interventions (average SUVmax 3.2 (mild), range 1.5–5.1). The median time-interval post-intervention to FAPI-PET was 47.5 months and was shorter when FAPI uptake was present (median 9.5 months) than when absent (median 60.1 months; p = 0.001). Cut-off time beyond which no FAPI uptake would be present post-intervention without FBP was 8.2 months, with a sensitivity, specificity, positive predictive value and negative predictive value of 82, 90, 99 and 31% respectively. No optimal cutoff point could be determined when considering interventions with FBP. No significant difference was detected between frequency of [68Ga]Ga-FAPI-46 and [18F]FDG uptake in intervention sites. Compared to [68Ga]Ga-PSMA-11, [68Ga]Ga-FAPI-46 revealed more frequent and intense post-interventional tracer uptake. Conclusion: [68Ga]Ga-FAPI-46 uptake from medical/invasive interventions without FBP appears to be time dependent, nearly always absent beyond 8 months post-intervention, but frequently present for years with FBP. [ABSTRACT FROM AUTHOR]

Fibroblasts embedded in a 3D matrix microenvironment can remodel the matrix to regulate cell adhesion and function. Collagen hydrogels are a useful in vitro system to study cell–matrix interactions in a 3D microenvironment. While major matrix reorganizations are easily recognizable, subtle changes in response to environmental or biochemical cues are challenging to discern in 3D hydrogels. Three-dimensional collagen gels at 1.0 mg/ml vs 1.5 mg/ml were labelled with DQ-collagen and imaged by confocal reflectance microscopy to evaluate these small changes. An image analysis pipeline was developed, hydrogel area and number of cross-sections analysed were optimized, and fibrillar collagen properties (number of branches, number of junctions, and average branch length) were quantified. While no significant changes were seen in fibrillar collagen organization between 1.0 mg/ml and 1.5 mg/ml collagen hydrogels, embedded mouse fibroblasts caused a significant increase in collagen branching and organization. Using the phalloidin-labelled cells, this change was quantitated in immediate proximity of the cell. A distinct increase in branch and junction numbers was observed, significantly altered by small changes in collagen concentration (1.0 mg/ml vs 1.5 mg/ml). Together, this analysis gives a quantitative evaluation of how cells respond to and modify their immediate microenvironment in a 3D collagen hydrogel. [ABSTRACT FROM AUTHOR]

Background: Various techniques have been employed in aesthetic medicine to combat skin aging, in particular that of the facial region. Hyaluronic acid is utilized to enhance moisture levels and extracellular matrix molecules. This study aims to histologically assess the effects of low molecular weight hyaluronic acid fragments combined with amino acids (HAAM) on facial skin rejuvenation through intradermal microinjections. Methods: A total of twenty women, with an average age of 45 and ranging from 35 to 64 years old, participated in the study, including 8 in menopause and 12 in the childbearing age group. Mesotherapy was used to administer HAAM to the patients. Prior to and three months after the treatment, each patient underwent small circular punch biopsies. Ultrasound examinations were conducted using B-mode, capturing 2D images in longitudinal or transverse orientations with frequencies ranging from 5 to 13 Mega-hertz (MY LAB X8, ESAOTE, Genova, Italy). A total of 60 ultrasound examinations were taken, with 30 collected before treatment and 30 after treatment. Results: The histological analysis demonstrates an increase in fibroblast activity resulting in the production of Type III reticular collagen, as well as an increased number of blood vessels and epidermal thickness. However, the analysis of ultrasound data before and after treatment showed no statistical difference in skin thickness in malar area, chin and mandibular angle. Conclusions: Histological assessments indicate that subcutaneous infiltration of HAAM has a substantial impact on the dermis of facial skin. [ABSTRACT FROM AUTHOR]

Pulmonary toxicity is a serious side effect of some specific anticancer drugs. Bleomycin is a well-known anticancer drug that triggers severe reactions in the lungs. It is an approved drug that may be prescribed for the treatment of testicular cancers, Hodgkin's and non-Hodgkin's lymphomas, ovarian cancer, head and neck cancers, and cervical cancer. A large number of experimental studies and clinical findings show that bleomycin can concentrate in lung tissue, leading to massive oxidative stress, alveolar epithelial cell death, the proliferation of fibroblasts, and finally the infiltration of immune cells. Chronic release of pro-inflammatory and pro-fibrotic molecules by immune cells and fibroblasts leads to pneumonitis and fibrosis. Both fibrosis and pneumonitis are serious concerns for patients who receive bleomycin and may lead to death. Therefore, the management of lung toxicity following cancer therapy with bleomycin is a critical issue. This review explains the cellular and molecular mechanisms of pulmonary injury following treatment with bleomycin. Furthermore, we review therapeutic targets and possible promising strategies for ameliorating bleomycin-induced lung injury. [ABSTRACT FROM AUTHOR]

The basement membrane zone is the interface between the epidermis and dermis, and it is disrupted in several skin conditions. Here, we report the results of a comprehensive investigation into the structural and molecular factors of the basement membrane zone in vitiligo, a dermatological disorder characterised by depigmented patches on the skin. Using electron microscopy and immunofluorescence staining, we confirmed abnormal basement membrane zone morphology and disrupted basement membrane zone architecture in human vitiliginous skin. Furthermore, we identified elevated expression of matrix metalloproteinase 2 (MMP2) in human dermal fibroblasts as a key factor responsible for basement membrane zone matrix degradation. In our in vitro and ex vivo models, overexpression of MMP2 in fibroblasts led to basement membrane zone disruption and melanocyte disappearance. Importantly, we reveal that the loss of melanocytes in vitiligo is primarily linked to their weakened adhesion to the basement membrane, mediated by binding between integrin β1 and laminin and discoidin domain receptor 1 and collagen IV. Finally, inhibition of matrix metalloproteinase 2 expression reversed depigmentation in a mouse model of vitiligo. In conclusion, our research shows the importance of basement membrane zone integrity in melanocyte residence and offers new avenues for therapeutic interventions to address this challenging skin condition. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland. [ABSTRACT FROM AUTHOR]

Apple pomace is the residue left after apples are squeezed. The majority of pomace produced worldwide is produced by the apple manufacturing industry, however, most of the pomace produced by the industry is discarded. Apple pomace contains functional ingredients, such as polyphenols and triterpenoids, and exerts several beneficial effects on human health; however, studies on its cosmetic effects on the skin are lacking. Therefore, herein, we investigated the effects of apple pomace extract (APE) on human skin fibroblasts (HSFs) in vitro. When HSFs were cultured with the extract for 72 h, the number of HSFs increased at concentrations of 10 and 20 µg/mL. Transcriptome analysis and reverse transcription-quantitative PCR results revealed that the extract upregulated the expression of hyaluronan synthase (HAS) 1, HAS2, and HAS3 and downregulated the expression of HYAL1, a gene encoding the hyaluronan-degrading enzyme, in HSFs. Additionally, enzyme-linked immunosorbent assay revealed increased amounts of factors related to skin extracellular matrix, such as type I collagen and hyaluronic acid, secreted in the culture supernatant. The western blotting results suggested that the extract induced extracellular signal-regulated kinase and protein kinase B phosphorylation in HSFs. Additionally, several GO_Terms related to mitosis were detected in the Gene Ontology analysis. This is the first study to show that APE induces the proliferation of HSFs and production of factors related to skin anti-aging. [ABSTRACT FROM AUTHOR]

Abstract Background In mouse models of atherosclerosis, knockout of the PLA2G2A gene has been shown to reduce the volume of atherosclerotic plaques. Clinical trials have demonstrated the potential of using the sPLA2 inhibitor Varespladib in combination with statins to reduce lipid levels. However, this approach has not yielded the expected results in reducing the risk of cardiovascular events. Therefore, it is necessary to further investigate the mechanisms of PLA2G2A. Methods Single-cell transcriptome data from two sets of carotid plaques, combined with clinical patient information. were used to describe the expression characteristics of PLA2G2A in carotid plaques at different stages. In order to explore the mechanisms of PLA2G2A, we conducted enrichment analysis, cell–cell communication analysis and single-cell regulatory network inference and clustering analyses. We validated the above findings at the cellular level. Results Our findings indicate that PLA2G2A is primarily expressed in vascular fibroblasts and shows significant cell interactions with macrophages in the early-stage, especially in complement and inflammation-related pathways. We also found that serum sPLA2 levels have stronger diagnostic value in patients with mild carotid artery stenosis. Subsequent comparisons of single-cell transcriptomic data from early and late-stage carotid artery plaques corroborated these findings and predicted transcription factors that might regulate the progression of early carotid atherosclerosis (CA) and the expression of PLA2G2A. Conclusions Our study discovered and validated that PLA2G2A is highly expressed by vascular fibroblasts and promotes plaque progression through the activation of macrophage complement and coagulation cascade pathways in the early-stage of CA.

Leecarlo Millano Lumban Gaol,1– 3 Ambrosius Purba,1 Rizki Diposarosa,1,2 Yuni Susanti Pratiwi1 1Faculty of Medicine Padjadjaran University, Bandung, Indonesia; 2Dr. Hasan Sadikin General Hospital, Bandung, Indonesia; 3Faculty of Medicine Krida Wacana Christian University, Jakarta, IndonesiaCorrespondence: Leecarlo Millano Lumban Gaol, Faculty of Medicine Padjadjaran University, Raya Bandung Sumedang Street No. 21, Hegarmanah, Jatinangor, Sumedang, Bandung, West Java, 45363, Indonesia, Email millanoleecarlo@gmail.comBackground: Fecal incontinence (FI) is the inability to control bowel movements, resulting in fecal leakage. If left untreated, FI can seriously impact the long-term well-being of individuals affected. Recently, using secretome has become a promising new treatment method. The secretome combines growth factors released outside cells during stem cell development, such as mesenchymal stem cells. It consists of soluble proteins, nucleic acids, fats, and extracellular vesicles, which contribute to different cell processes. The primary aim is to assess the impact of hypoxic secretome administration on accelerating wound healing through the HIF-1α pathway in a post-sphincterotomy rat model.Methods: The study was conducted with two distinct groups of 10 rats each, the control and treatment groups, which were injected with hypoxic secretome at 0.3 mL. The inclusion criteria for the rats were as follows: male gender, belonging to the Sprague-Dawley strain, aged between 12 to 16 weeks, with an average body weight ranging from 240 to 250 grams.Results: There was an increase in HIF-1α gene expression in both groups. The treatment group 37 was significantly higher on day 42 (p = 0.001). VEGF increased significantly in the treatment 38 group on day 42 (p = 0.015). The neovascularization score increased significantly in the treatment 39 group during the first 24 hours (p = 0.004). The fibroblast score increased significantly in the 40 treatment group in the first 24 hours (p = 0.000) and 42 days (p = 0.035). After being given secretome, there was a higher increase in % collagen area and collagen area (μm2) in the treatment group compared to the control group (27,77 vs 11.01) and (419.027,66 vs 186.694,16).Conclusion: The use of hypoxic secretome has a significant effect as a choice for the treatment of anal sphincter injury after sphincterotomy through the HIF-1α-VEGF-Fibroblast pathway.Keywords: fecal incontinence, fibroblast, HIF-1α, hypoxic secretome, neovascularization, VEGF

Abstract Background Idiopathic pulmonary fibrosis (IPF) is a chronic and lethal lung disorder for which effective treatments remain limited. Recent investigations revealed a potential link between altered glucose metabolism and the activation of fibroblasts, the key cells responsible for generating and depositing extracellular matrix proteins within the lung interstitium during IPF development. Method In this study, we aimed to investigate the potential therapeutic impact of albendazole on fibroblast to myofibroblast transition in IPF. We assess albendazole’s effectiveness in attenuating the activation of fibroblasts. We focused on elucidating the mechanism underlying albendazole's impact on TGF-β1-induced aerobic glycolysis in both lung tissues and fibroblasts obtained from patients with IPF and other lung fibrosis types. Furthermore, the antifibrotic effects of oral administration of albendazole were investigated in mouse models of pulmonary fibrosis induced by BLM or SiO2. Human precision-cut lung slices were employed to evaluate the impact of albendazole following TGF-β1 stimulation. Result In this work, we demonstrated that albendazole, a first-line broad-spectrum anthelmintic drug, effectively attenuated fibroblast to myofibroblast transition through alleviating TGF-β1-induced aerobic glycolysis dependent on the LRRN3/PFKFB3 signaling pathway. Additionally, LRRN3 expression was downregulated in both lung tissues and fibroblasts from patients with IPF and other types of lung fibrosis. Importantly, the levels of LRRN3 correlated with the progression of the disease. Notably, oral administration of albendazole exerted potent antifibrotic effects in mouse models of pulmonary fibrosis induced by BLM or SiO2, and in human precision-cut lung slices after TGF-β1 stimulation, as evidenced by improvements in lung morphology, reduced myofibroblast formation, and downregulation of α-SMA, collagen type 1 and Fibronectin expression in the lungs. Conclusion Our study implies that albendazole can act as a potent agonist of LRRN3 during fibroblast to myofibroblast differentiation and its oral administration shows potential as a viable therapeutic approach for managing IPF.

Abstract Background Myocardial infarction (MI) induces complex transcriptional changes across diverse cardiac cell types. Single-cell RNA sequencing (scRNA-seq) provides an unparalleled ability to discern cellular diversity during infarction, yet the veracity of these discoveries necessitates confirmation. This investigation sought to elucidate MI mechanisms by integrating scRNA-seq and bulk RNA-seq data. Methods Publicly available scRNA-seq (GSE136088) and bulk RNA-seq (GSE153485) data from mice MI models were analyzed. Cell types were annotated, and differential expression analysis conducted. Bulk RNA-seq underwent quality control, principal component analysis, and differential expression analysis. Results In scRNA-seq data, the comparison between MI and sham groups unveiled a reduction in endothelial cell populations, but macrophages and monocytes increased. Within fibroblast subgroups, three distinct categories were discerned, with two exhibiting upregulation in MI. Notably, endothelial cells exhibited an elevated expression of genes associated with apoptosis and ferroptosis. In bulk RNA-seq analysis, distinct patterns emerged when comparing MI and sham groups. Specifically, six genes linked to endothelial ferroptosis exhibited heightened expression in MI group, thereby corroborating the scRNA-seq findings. Moreover, the examination of isolated cardiac macrophages from mice MI model revealed increased expression of Spp1, Col1a2, Col3a1, Ctsd, and Lgals3 compared to sham group, thus substantiating the dysregulation of macrophage apoptosis-related proteins following MI. Conclusion MI altered the transcriptomic landscapes of cardiac cells with increased expression of apoptotic genes. Moreover, the upregulation of macrophage apoptosis marker was confirmed within MI models. The presence of endothelial cell depletion and ferroptosis in MI has been demonstrated.

Abstract Background The tumor microenvironment (TME) provides a region for intricate interactions within or between immune and non-immune cells. We aimed to reveal the tissue architecture and comprehensive landscape of cells within the TME of colorectal cancer (CRC). Methods Fresh frozen invasive adenocarcinoma of the large intestine tissue from 10× Genomics Datasets was obtained from BioIVT Asterand. The integration of microarray-based spatial transcriptomics (ST) and RNA sequencing (RNA-seq) was applied to characterize gene expression and cell landscape within the TME of CRC tissue architecture. Multiple R packages and deconvolution algorithms including MCPcounter, XCELL, EPIC, and ESTIMATE methods were performed for further immune distribution analysis. Results The subpopulations of immune and non-immune cells within the TME of the CRC tissue architecture were appropriately annotated. According to ST and RNA-seq analyses, a heterogeneous spatial atlas of gene distribution and cell landscape was comprehensively characterized. We distinguished between the cancer and stromal regions of CRC tissues. As expected, epithelial cells were located in the cancerous region, whereas fibroblasts were mainly located in the stroma. In addition, the fibroblasts were further subdivided into two subgroups (F1 and F2) according to the differentially expressed genes (DEGs), which were mainly enriched in pathways including hallmark-oxidative-phosphorylation, hallmark-e2f-targets and hallmark-unfolded-protein-response. Furthermore, the top 5 DEGs, SPP1, CXCL10, APOE, APOC1, and LYZ, were found to be closely related to immunoregulation of the TME, methylation, and survival of CRC patients. Conclusions This study characterized the heterogeneous spatial landscape of various cell subtypes within the TME of the tissue architecture. The TME-related roles of fibroblast subsets addressed the potential crosstalk among diverse cells.

Abstract Background Cryopreservation is a crucial procedure for safeguarding cells or other biological constructs, showcasing considerable potential for applications in tissue engineering and regenerative medicine. Aims This study aimed to evaluate the effectiveness of different cryopreservation conditions on human cells viability. Methods A set of cryopreserved data from Department of Tissue Engineering and Regenerative Medicine (DTERM) cell bank were analyse for cells attachment after 24 h being revived. The revived cells were analysed based on different cryopreservation conditions which includes cell types (skin keratinocytes and fibroblasts, respiratory epithelial, bone marrow mesenchymal stem cell (MSC); cryo mediums (FBS + 10% DMSO; commercial medium); storage durations (0 to > 24 months) and locations (tank 1–2; box 1–5), and revival methods (direct; indirect methods). Human dermal fibroblasts (HDF) were then cultured, cryopreserved in different cryo mediums (HPL + 10% DMSO; FBS + 10% DMSO; Cryostor) and stored for 1 and 3 months. The HDFs were revived using either direct or indirect method and cell number, viability and protein expression analysis were compared. Results In the analysis cell cryopreserved data; fibroblast cells; FBS + 10% DMSO cryo medium; storage duration of 0–6 months; direct cell revival; storage in vapor phase of cryo tank; had the highest number of vials with optimal cell attachment after 24 h revived. HDFs cryopreserved in FBS + 10% DMSO for 1 and 3 months with both revival methods, showed optimal live cell numbers and viability above 80%, higher than other cryo medium groups. Morphologically, the fibroblasts were able to retain their phenotype with positive expression of Ki67 and Col-1. HDFs cryopreserved in FBS + 10% DMSO at 3 months showed significantly higher expression of Ki67 (97.3% ± 4.62) with the indirect revival method, while Col-1 expression (100%) was significantly higher at both 1 and 3 months compared to other groups. Conclusion In conclusion, fibroblasts were able to retain their characteristics after various cryopreservation conditions with a slight decrease in viability that may be due to the thermal-cycling effect. However, further investigation on the longer cryopreservation periods should be conducted for other types of cells and cryo mediums to achieve optimal cryopreservation outcomes.

Xiangan Gong,1,2 Qian Zhao,1,2 Huimin Zhang,1,2 Rui Liu,1,2 Jie Wu,1,2 Nanxin Zhang,3 Yuanxian Zou,1,2 Wen Zhao,1,2 Ran Huo,1,2,4 Rongtao Cui1– 4 1Department of Burn and Plastic Surgery, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, People’s Republic of China; 2Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, People’s Republic of China; 3School of Clinical Medicine, Shandong Second Medical University, Weifang, People’s Republic of China; 4Department of Burn and Plastic Surgery, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, People’s Republic of ChinaCorrespondence: Rongtao Cui, Department of Burn and Plastic Surgery, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, People’s Republic of China, Tel +86 18653170822, Email cuirt1986@outlook.comAbstract: Pathological scarring results from aberrant cutaneous wound healing due to the overactivation of biological behaviors of human skin fibroblasts, characterized by local inordinate inflammation, excessive extracellular matrix and collagen deposition. Yet, its underlying pathogenesis opinions vary, which could be caused by increased local mechanical tension, enhanced and continuous inflammation, gene mutation, as well as cellular metabolic disorder, etc. Metabolic reprogramming is the process by which the metabolic pattern of cells undergoes a systematic adjustment and transformation to adapt to the changes of the external environment and meet the needs of their growth and differentiation. Therefore, the abnormality of metabolic reprogramming in cells within wounds and scars attaches great importance to scar formation. Mesenchymal stem cells-derived exosomes (MSC-Exo) are the extracellular vesicles that play an important role in tissue repair, cancer treatment as well as immune and metabolic regulation. However, there is not a systematic work to detail the relevant studies. Herein, we gave a comprehensive summary of the existing research on three main metabolisms, including glycometabolism, lipid metabolism and amino acid metabolism, and MSC-Exo regulating metabolic reprogramming in wound healing and scar formation for further research reference.Keywords: mesenchymal stem cells-derived exosomes, metabolic reprogramming, scar, wound healing, fibroblast

Abstract Background/Aims Gastric cancer (GC) ranks among the prevalent types of cancer, and its progression is influenced by the tumor microenvironment (TME). A comprehensive comprehension of the TME associated with GC has the potential to unveil therapeutic targets of significance. Methods The complexity and heterogeneity of TME interactions were revealed through our investigation using an integrated analysis of single-cell and bulk-tissue sequencing data. Results We constructed a single-cell transcriptomic atlas of 150,913 cells isolated from GC patients. Our analysis revealed the intricate nature and heterogeneity of the GC TME and the metabolic properties of major cell types. Furthermore, two cell subtypes, LOX+ Fibroblasts and M2 Macrophages, were enriched in tumor tissue and related to the outcome of GC patients. In addition, LOX+ Fibroblasts were significantly associated with M2 macrophages. immunofluorescence double labeling indicated LOX+ Fibroblasts and M2 Macrophages were tightly localized in GC tissue. The two cell subpopulations strongly interacted in a hypoxic microenvironment, yielding an immunosuppressive phenotype. Our findings further suggest that LOX+ Fibroblasts may act as a trigger for inducing the differentiation of monocytes into M2 Macrophages via the IL6-IL6R signaling pathway. Conclusions Our study revealed the intricate and interdependent communication network between the fibroblast and macrophage subpopulations, which could offer valuable insights for targeted manipulation of the tumor microenvironment.

Abstract Fibrosis is an abnormal tissue healing process characterized by the excessive accumulation of ECM components, such as COL I and COL III, in response to tissue injury or chronic inflammation. Recent advances in epitranscriptomics have underscored the importance of m6A modification in fibrosis. m6A, the most prevalent modification in eukaryotic RNA, is catalyzed by methyltransferases (e.g., METTL3), removed by demethylases (e.g., FTO), and recognized by reader proteins (e.g., YTHDF1/2). These modifications are crucial in regulating collagen metabolism and associated diseases. Understanding the role of m6A modification in fibrosis and other collagen-related conditions holds promise for developing targeted therapies. This review highlights the latest progress in this area.

Abstract Background Macrophage-based cell therapy is promising in solid tumors, but the efficient acquisition of macrophages remains a challenge. Induced pluripotent stem cell (iPSC)-induced macrophages are a valuable source, but time-consuming and costly. The application of reprogramming technologies allows for the generation of macrophages from somatic cells, thereby facilitating the advancement of cell-based therapies for numerous malignant diseases. Methods The composition of CD45+ myeloid-like cell complex (MCC) and induced macrophage (iMac) were analyzed by flow cytometry and single-cell RNA sequencing. The engraftment capacity of CD45+ MCC was evaluated by two transplantation assays. Regulation of c-Myc on MafB was evaluated by ChIP-qPCR and promoter reporter and dual luciferase assays. The phenotype and phagocytosis of iMac were explored by flow cytometry and immunofluorescence. Leukemia, breast cancer, and patient-derived tumor xenograft models were used to explore the anti-tumor function of iMac. Results Here we report on the establishment of a novel methodology allowing for reprogramming fibroblasts into functional macrophages with phagocytic activity by c-Myc overexpression. Fibroblasts with ectopic expression of c-Myc in iPSC medium rapidly generated CD45+ MCC intermediates with engraftment capacity as well as the repopulation of distinct hematopoietic compartments. MCC intermediates were stably maintained in iPSC medium and continuously generated functional and highly pure iMac just by M-CSF cytokine stimulation. Single-cell transcriptomic analysis of MCC intermediates revealed that c-Myc up-regulated the expression of MafB, a major regulator of macrophage differentiation, to promote macrophage differentiation. Characterization of the iMac activity showed NF-κB signaling activation and a pro-inflammatory phenotype. iMac cells displayed significantly increased in vivo persistence and inhibition of tumor progression in leukemia, breast cancer, and patient-derived tumor xenograft models. Conclusions Our findings demonstrate that c-Myc alone is enough to reprogram fibroblasts into functional macrophages, supporting that c-Myc reprogramming strategy of fibroblasts can help circumvent long-standing obstacles to gaining “off-the-shelf” macrophages for anti-cancer immunotherapy.

Background: Methamphetamine use can provide a quick and pleasurable rush, increased energy, heightened attention, and euphoria, but may also result in many adverse effects. Various cell lines have been utilized in vitro to determine the adverse impacts of methamphetamine on those cells. As enough data are not available on the effect of methamphetamine on skin fibroblast cells, this study determined its in vitro effect on proliferation, differentiation and apoptosis of human skin fibroblast cells.Methods: Phenotypic characteristics of fibroblasts cells were determined and real-time PCR examined the expression of matrix metalloproteinase1 (MMP1), matrix metalloproteinase 3 (MMP3), integrin alpha 11 (ITGA11), CD106, CD10, and CD26 markers. MTT assay checked the toxicity of recreational doses of 6 and 60 μM of methamphetamine. Quantitative real time polymerase chain reaction (qPCR) assessed expression of Bax, Bcl-2 and PPARγ genes.Results: Fibroblast cells were morphologically spindle-shape and were positive for fibroblast markers of CD10, CD26, MMP1 and MMP3 and negative for mesenchymal markers of ITGA11 and CD106. MTT assay revealed a decline in proliferation of fibroblast cells when they were exposed to methamphetamine. The expression of Bax and PPARγ genes increased and decreased for Bcl-2 gene after exposure of cells to methamphetamine.Conclusion: Our results confirmed adverse effects of methamphetamine on proliferation, viability and differentiation of skin fibroblast cells revealing a reduction in cell proliferation and differentiation as well as an increase in cell apoptosis. These findings can open a window to health status of people who target methamphetamine use for recreational purposes.

BACKGROUND: On the basis of the mounting evidence that type 17 T (T17) cells and increased IL-17 play a key role in driving hidradenitis suppurativa (HS) lesion development, biologic agents used previously in psoriasis that block signaling of IL-17A and/or IL-17F isoforms have been repurposed to treat HS. OBJECTIVE: Our research aimed to characterize the transcriptome of HS T17 cells compared to the transcriptome of psoriasis T17 cells, along with their ligand-receptor interactions with neighborhood immune cell subsets. METHODS: Single-cell data of 12,300 cutaneous immune cells from 8 deroofing surgical HS skin samples including dermal tunnels were compared to single-cell data of psoriasis skin (19,525 cells from 11 samples) and control skin (11,920 cells from 10 samples). All single-cell data were generated by the same protocol. RESULTS: HS T17 cells expressed lower levels of IL23R and higher levels of IL1R1 and IL17F compared to psoriasis T17 cells (P < .05). HS Treg cells expressed higher levels of IL1R1 and IL17F compared to psoriasis Treg cells (P < .05). Semimature dendritic cells were the major immune cell subsets expressing IL1B in HS, and IL-1β ligand-receptor interactions between semimature dendritic cells and T17 cells were increased in HS compared to psoriasis (P < .05). HS dermal tunnel keratinocytes expressed inflammatory cytokines (IL17C, IL1A, IL1B, and IL6) that differed from the HS epidermis keratinocytes (IL36G) (P < .05). IL6, which synergizes with IL1B to maintain cytokine expression in T17 cells, was mainly expressed by fibroblasts in HS, which also expressed IL11+ inflammatory fibroblast genes (IL11, IL24, IL6, and POSTN) involved in the paracrine IL-1/IL-6 loop. CONCLUSION: The IL-1β-T17 cell cytokine axis is likely a dominant pathway in HS with HS T17 cells activated by IL-1β signaling, unlike psoriasis T17 cells, which are activated by IL-23 signaling.

BACKGROUND: Quercetin has anti-inflammatory, anti-cancer, anti-oxidation, anti-aging, anti-depression and other pharmacological effects, and has high medicinal value. Quercetin can promote wound healing in normal rats, but few drugs with quercetin as the main component have been developed, which limits its wide application in clinical practice. OBJECTIVE: To investigate the application effect of quercetin-carboxymethyl chitosan hydrogel on diabetic wound in rats by loading quercetin with hydrogel material. METHODS: (1) Carboxymethyl chitosan hydrogels and quercetin-carboxymethyl chitosan hydrogels were prepared respectively, and the micromorphology and in vitro drug release properties of the hydrogels were characterized. (2) Cell experiment: Mouse L929 fibroblasts were cultured in four groups. The blank control group was cultured conventionally. Carboxymethyl chitosan hydrogel, quercetin solution and quercetin-carboxymethyl chitosan hydrogel were added to pure hydrogel group, drug group, and drug-loaded hydrogel group, respectively, to detect cell proliferation and migration ability. (3) Animal experiments: Diabetic models were established in 80 SD rats. After successful modeling, full-layer skin defect wounds with a diameter of 2 cm were made on the back of rats, and these models were randomly divided into four groups. Normal saline, carboxymethyl chitosan hydrogel, quercetin solution, and quercetin-carboxymethyl chitosan hydrogel were injected into the wounds of blank control group, pure hydrogel group, drug group, and drug-loaded hydrogel group, respectively. Each group contained 20 animals, which were bound with sterile gauze. Wound healing, pathological morphology, expression of inflammatory factors, and angiogenesis were observed after operation. RESULTS AND CONCLUSION: (1) Under scanning electron microscope, the microstructures of the two hydrogels were similar, both showed loose porous network structure, and quercetin-carboxymethyl chitosan hydrogels had good drug release performance in vitro. (2) Compared with blank control group, the cell proliferation and mobility of the other three groups were increased (P < 0.05). The cell proliferation and mobility of drug-loaded hydrogel group were higher than those of pure hydrogel group and drug group (P < 0.05). (3) The wound healing rate of the drug-loaded hydrogel group was higher than that of the other three groups at 5 and 11 days after operation. The wound healing rate of rats in the hydrogel group, pure hydrogel group, and drug group reached 100% 18 days after operation, which was higher than that in the blank control group (P < 0.05). Hematoxylin-eosin staining showed that intact skin and skin appendages were visible on the wounds of rats in the drug-loaded hydrogel group 18 days after surgery, while intact skin and skin appendages were visible on the wounds of rats in the blank control group, pure hydrogel group, and drug group 25 days after surgery. The levels of tumor necrosis factor α and interleukin-6 in the drug-loaded hydrogel group were lower than those in the blank control group at 5, 11, and 18 days after surgery (P < 0.05), and the levels of transforming growth factor β1 at 11 and 18 days after surgery were lower than those in the blank control group (P < 0.05). The mRNA expressions of CD31 and vascular endothelial growth factor α in the drug-loaded hydrogel group were higher than those in the other three groups at 11 and 18 days after operation (P < 0.05). (4) These findings indicate that quercetin in quercetin carboxymethyl chitosan hydrogel can regulate inflammatory response, accelerate angiogenesis, promote the proliferation and migration of fibroblasts, and enhance the healing of diabetic wounds in rats [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the role of M2 macrophages in subconjunctival fibrosis after silicone implantation (SI) and investigate the underlying mechanisms. Materials and methods: A model of subconjunctival fibrosis was established by SI surgery in rabbit eyes. M2 distribution and collagen deposition were evaluated by histopathology. The effects of M2 cells on the migration (using wound-scratch assay) and activation (by immunofluorescence and western blotting) of human Tenon's fibroblasts (HTFs) were investigated. Results: There were more M2 macrophages (CD68+/CD206+ cells) occurring in tissue samples around silicone implant at 2weeks postoperatively. Dense collagen deposition was observed at 8 weeks after SI. In vitro experiment showed M2 expressed high level of CD206 and transforming growth factor-β1 (TGF-β1). The M2-conditioned medium promoted HTFs migration and the synthesis of collagen I and fibronectin. Meanwhile, M2-conditioned medium increased the protein levels of TGF-β1, TGF-βR II, p-Smad2/3, yes-associated protein (YAP), and transcriptional coactivator with PDZ-binding motif (TAZ). Verteporfin, a YAP inhibitor, suppressed TGF-β1/Smad2/3-YAP/TAZ pathway and attenuated M2-induced extracellular matrix deposition by HTFs. Conclusions: TGF-β1/Smad2/3-YAP/TAZ signalling may be involved in M2-induced fibrotic activities in HTFs. M2 plays a key role in promoting subconjunctival fibrosis and can serve as an attractive target for anti-fibrotic therapeutics. [ABSTRACT FROM AUTHOR]

Abstract 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.

Abstract Idiopathic pulmonary fibrosis is a lethal, progressive, and irreversible condition that has become a significant focus of medical research due to its increasing incidence. This rising trend presents substantial challenges for patients, healthcare providers, and researchers. Despite the escalating burden of pulmonary fibrosis, the available therapeutic options remain limited. Currently, the United States Food and Drug Administration has approved two drugs for the treatment of pulmonary fibrosis—nintedanib and pirfenidone. However, their therapeutic effectiveness is limited, and they cannot reverse the fibrosis process. Additionally, these drugs are associated with significant side effects. Myofibroblasts play a central role in the pathophysiology of pulmonary fibrosis, significantly contributing to its progression. Consequently, strategies aimed at inhibiting myofibroblast differentiation or promoting their dedifferentiation hold promise as effective treatments. This review examines the regulation of myofibroblast dedifferentiation, exploring various signaling pathways, regulatory targets, and potential pharmaceutical interventions that could provide new directions for therapeutic development.