Mechanical pressure-induced dedifferentiation of myofibroblasts inhibits scarring via SMYD3/ITGBL1 signaling

HBV activates hepatic stellate cells through RUNX2/ITGBL1 axis

BACKGROUND

Chronic hepatitis B (CHB) remains a global health challenge, with liver fibrosis serving as a critical determinant of disease progression. Despite antiviral treatments, liver fibrosis often persists in CHB patients, highlighting the need for additional biomarkers and therapeutic targets. This study investigates the molecular mechanism underlying HBV-induced liver fibrosis, focusing on the role of RUNX2 in regulating integrin beta-like 1 (ITGBL1), a key factor in fibrogenesis.

METHODS

We examined the relationship between RUNX2 and ITGBL1 in both in vitro hepatocyte models and an in vivo HBV mouse model. Using chromatin immunoprecipitation (ChIP), luciferase reporter assays, and Western blotting, we assessed RUNX2 binding to the ITGBL1 promoter and its impact on gene expression. We also evaluated the effects of RUNX2 inhibition using Vitamin D3 and CADD522 on ITGBL1 expression and hepatic stellate cell activation.

RESULTS

Our findings reveal that RUNX2 directly binds to the ITGBL1 promoter, enhancing its expression and promoting hepatic stellate cell activation. We show that HBV infection significantly upregulates both RUNX2 and ITGBL1 in liver cells. Inhibition of RUNX2 with Vitamin D3 or CADD522 significantly reduced ITGBL1 levels and blocked hepatic stellate cell activation. These results suggest that the RUNX2/ITGBL1 pathway is critical in the progression of liver fibrosis in HBV-infected patients.

CONCLUSIONS

RUNX2 promotes liver fibrosis in HBV-infected patients by upregulating ITGBL1 expression. Our findings suggest that targeting RUNX2 could be a potential therapeutic approach to mitigate liver fibrosis in chronic hepatitis B.

CAFs activated by YAP1 upregulate cancer matrix stiffness to mediate hepatocellular carcinoma progression

BACKGROUND

The stiffness of the matrix is closely related to the progression of hepatocellular carcinoma (HCC). Although direct targeting of stromal rigidity in HCC remains a clinical challenge, cancer-associated fibroblasts (CAFs) are considered key contributors to this process. Given the heterogeneity of CAFs, this study explored the relationship between specific CAF subsets and liver cancer matrix stiffness, aiming to identify novel therapeutic targets for HCC patients.

METHODS

Single-cell sequencing datasets were leveraged to identify cell types within liver cancer and characterize the transcriptomic profiles of CAFs. Prognostic analysis, utilizing the Gene Expression Profiling Interactive Analysis (GEPIA) and The Cancer Genome Atlas (TCGA) liver cancer datasets, assessed the correlation between matrix stiffness-related genes and HCC patient outcomes. Pseudo-time analysis was applied to trace the developmental trajectories of CAFs. By calculating intercellular communication probabilities and analyzing transcription factor activity, the functions and interactions of different CAF subsets were elucidated. Gene Ontology (GO) analysis was used to explore the functional roles of CAFs in distinct Yes-associated protein 1 (YAP1) groups. Finally, cellular experiments and animal experiments were further conducted to validate the hypotheses of this study.

RESULTS

This study identified CAF subpopulations based on single-cell sequencing data and analyzed transcriptional changes within these subpopulations. Key findings include the identification of collagen type I alpha 1 (COL1A1), collagen type III alpha 1 (COL3A1), and lysyloxidase (LOX) as pivotal node genes during CAF development. Moreover, the expression of matrix stiffness-related genes was inversely correlated with the prognosis of HCC patients. Notably, the YAP1-positive CAF subpopulation emerged as the primary contributor to matrix stiffness in liver cancer. This subpopulation upregulates the expression of matrix stiffness-related genes and promotes tumor progression by activating signaling pathways such as autophagy and GTPase activity regulation. Cellular experiments and animal studies further validated this conclusion.

CONCLUSION

This single-cell analysis uncovered the functional roles of CAFs in liver cancer. The YAP1-positive CAF subpopulation, in particular, was shown to contribute to matrix stiffness by upregulating the expression of relevant genes and promoting tumor progression through the activation of specific signaling pathways.

Epidermal stem cell derived exosomes-induced dedifferentiation of myofibroblasts inhibits scarring via the miR-203a-3p/PIK3CA axis

Hypertrophic scar (HS) is a common fibroproliferative disorders with no fully effective treatments. The conversion of fibroblasts to myofibroblasts is known to play a critical role in HS formation, making it essential to identify molecules that promote myofibroblast dedifferentiation and to elucidate their underlying mechanisms. In this study, we used comparative transcriptomics and single-cell sequencing to identify key molecules and pathways that mediate fibrosis and myofibroblast transdifferentiation. Epidermal stem cell-derived extracellular vesicles (EpiSC-EVs) were isolated via ultracentrifugation and filtration, followed by miRNA sequencing to identify miRNAs targeting key molecules. After in vitro and in vivo treatment with EpiSC-EVs, we assessed antifibrotic effects through scratch assays, collagen contraction assays, Western blotting, and immunofluorescence. Transcriptomic sequencing and rescue experiments were used to investigate the molecular mechanism by which miR-203a-3p in EpiSC-EVs induces myofibroblast dedifferentiation. Our results indicate that PIK3CA is overexpressed in HS tissues and positively correlates with fibrosis. EpiSC-EVs were absorbed by scar-derived fibroblasts, promoting dedifferentiation from myofibroblasts to quiescent fibroblasts. Mechanistically, miR-203a-3p in EpiSC-EVs plays an essential role in inhibiting PIK3CA expression and PI3K/AKT/mTOR pathway hyperactivation, thereby reducing scar formation. In vivo studies confirmed that EpiSC-EVs attenuate excessive scarring through the miR-203a-3p/PIK3CA axis, suggesting EpiSC-EVs as a promising therapeutic approach for HS.

Integrated analysis of bioinformatics, mendelian randomization, and experimental validation reveals novel diagnostic and therapeutic targets for osteoarthritis: progesterone as a potential therapeutic agent

BACKGROUND

Osteoarthritis (OA), characterized by progressive degeneration of cartilage and reactive proliferation of subchondral bone, stands as a prevalent condition in orthopedic clinics. However, the precise mechanisms underlying OA pathogenesis remain inadequately explored.

METHODS

In this study, Random Forest (RF), Least Absolute Shrinkage and Selection Operator (LASSO), and Support Vector Machine-Recursive Feature Elimination (SVM-RFE) machine learning techniques were employed to identify hub genes. Based on these hub genes, an Artificial Neural Network (ANN) diagnostic model was constructed. The Drug Signatures Database (DSigDB) was utilized to screen small-molecule drugs targeting these hub genes, and molecular docking analyses and molecular dynamics simulations were employed to explore and validate the binding interactions between proteins and small-molecule drugs. Expression changes of the hub genes under inflammatory conditions were validated through in vitro experiments, including RT-qPCR and Western blotting, and the therapeutic effects of the identified small-molecule drug on chondrocytes under inflammatory conditions were further verified in vitro. Lastly, Mendelian randomization analysis was conducted to examine the causal association between progesterone levels and various OA phenotypes.

RESULTS

In this study, we identified three hub genes: interleukin 1 receptor-associated kinase 3 (IRAK3), integrin subunit beta-like 1 (ITGBL1), and Ras homolog family member U (RHOU). An Artificial Neural Network (ANN) diagnostic model constructed based on these hub genes demonstrated excellent performance in both training and validation phases. Screening with the Drug Signatures Database (DSigDB) identified progesterone as a small-molecule drug targeting these key proteins. Molecular docking analysis using AutoDock Vina revealed that progesterone exhibited binding energies of ≤ -7 kcal/mol with each of the key proteins, indicating strong binding affinity. Furthermore, molecular dynamics simulations validated the stability and strength of these interactions. RT-qPCR and Western blotting confirmed the downregulation of the hub genes in IL-1β-treated chondrocytes. Western blotting also demonstrated the potential therapeutic effects of progesterone on IL-1β-treated chondrocytes. Finally, Mendelian randomization analysis established a significant association between progesterone levels and multiple OA phenotypes.

CONCLUSION

In our study, IRAK3, ITGBL1, and RHOU were identified as potential novel diagnostic and therapeutic targets for OA. Progesterone was preliminarily validated as a small-molecule drug with potential effects on OA. Further research is crucial to elucidate the pathogenesis of OA and the specific therapeutic mechanisms involved.

The transcription factor TCF4 regulates the miR-494-3p/THBS1 axis in the fibrosis of pathologic scars

BACKGROUND

The fibrosis of pathologic scar (PS) is formed by the excessive deposition of extracellular matrix, resulting in an abnormal scar. Recent clinical tests have indicated that the regulation of PS fibroblast cells (PSF cells) proliferation can serve as an intervention measure for PS. Our work aimed to elucidate the specific mechanism of action of TCF4 on the progression of PS fibrosis.

METHODS

Our study used qRT-PCR and Western blot to search for the expression of key proteins in PS clinical samples and cells. Transwell, CCK-8, and wound scratch assays were employed to analyze the proliferation and migration of PSF cells. CHIP, dual-luciferase reporter experiments, and bio-informatics analysis were used to analyze the interactions between molecules.

RESULTS

The analysis of PS clinical samples confirmed a positive correlation between TCF4 and miR-494-3p. This regulatory mechanism was related to the progression of PS. We verified that the overexpression of miR-494-3p or the knockdown of THBS1 both suppressed the proliferation and migration of PSF cells. Furthermore, we also confirmed the binding relationships between TCF4, miR-494-3p, and THBS1. Simultaneously, we verified the existence of the TCF4/miR-494-3p/THBS1 regulatory network in PS. This regulatory process affects the development of PS fibrosis.

CONCLUSION

Our study results indicate that TCF4, miR-494-3p, and THBS1 are abnormally expressed in PS. TCF4 increases the proliferation and migration ability of PSF cells through the miR-494-3p/THBS1 signaling pathway, which promotes the fibrosis of PS.

Novel integrated multiomics analysis reveals a key role for integrin beta-like 1 in wound scarring

Exacerbation of scarring can originate from a minority fibroblast population that has undergone inflammatory-mediated genetic changes within the wound microenvironment. The fundamental relationship between molecular and spatial organization of the repair process at the single-cell level remains unclear. We have developed a novel, high-resolution spatial multiomics method that integrates spatial transcriptomics with scRNA-Seq; we identified new characteristic features of cell-cell communication and signaling during the repair process. Data from PU.1-/- mice, which lack an inflammatory response, combined with scRNA-Seq and Visium transcriptomics, led to the identification of nine genes potentially involved in inflammation-related scarring, including integrin beta-like 1 (Itgbl1). Transgenic mouse experiments confirmed that Itgbl1-expressing fibroblasts are required for granulation tissue formation and drive fibrogenesis during skin repair. Additionally, we detected a minority population of Acta2high-expressing myofibroblasts with apparent involvement in scarring, in conjunction with Itgbl1 expression. IL1β signaling inhibited Itgbl1 expression in TGFβ1-treated primary fibroblasts from humans and mice. Our novel methodology reveal molecular mechanisms underlying fibroblast-inflammatory cell interactions that initiate wound scarring.

Matrix stiffness-dependent PD-L2 deficiency improves SMYD3/xCT-mediated ferroptosis and the efficacy of anti-PD-1 in HCC

INTRODUCTION

Heterogeneous tissue stiffening promotes tumor progression and resistance, and predicts a poor clinical outcome in patients with hepatocellular carcinoma (HCC). Ferroptosis, a congenital tumor suppressive mechanism, mediates the anticancer activity of various tumor suppressors, including immune checkpoint inhibitors, and its induction is currently considered a promising treatment strategy. However, the role of extracellular matrix (ECM) stiffness in regulating ferroptosis and ferroptosis-targeted resistance in HCC remains unclear.

OBJECTIVES

This research aimed to explore how extracellular matrix stiffness affects ferroptosis and its treatment efficacy in HCC.

METHODS

Ferroptosis analysis was confirmed via cell activity, intracellular ferrous irons, and mitochondrial pathology assays. Baseline PD-L2, SMYD3, and SLC7A11 (xCT) were evaluated in 67 sorafenib-treated patients with HCC (46 for non-responder and 21 for responder) from public data. The combined efficacy of shPD-L2, sorafenib, and anti-PD-1 antibody in HCC was investigated in vivo.

RESULTS

Here, we revealed that matrix stiffness-induced PD-L2 functions as a suppressor of xCT-mediated ferroptosis to promote cancer growth and sorafenib resistance in patients with HCC. Mechanically, matrix stiffening induced the expression of PD-L2 by activating SMYD3/H3K4me3, which acts as an RNA binding protein to enhance the mRNA stability of FTL and elevate its protein level. Knockdown of PD-L2 significantly promoted xCT-mediated ferroptosis induced by RSL3 or sorafenib on stiff substrate via FTL, whereas its overexpression abolished these upward trends. Notably, PD-L2 deletion in combination with sorafenib and anti-PD-1 antibody significantly sensitized HCC cells and blunted cancer growth in vivo. Additionally, we found the ferroptosis- and immune checkpoint-related prognostic genes that combined PD-L2, SLC7A11 and SYMD3 well predict the clinical efficacy of sorafenib in patients with HCC.

CONCLUSION

These findings expand our understanding of the mechanics-dependent PD-L2 role in ferroptosis, cancer progression and resistance, providing a basis for the clinical translation of PD-L2 as a therapeutic target or diagnostic biomarker.

Graphene Quantum Dots Reduce Hypertrophic Scar by Inducing Myofibroblasts To Be a Quiescent State

Contrary to the initial belief that myofibroblasts are terminally differentiated cells, myofibroblasts have now been widely recognized as an activation state that is reversible. Therefore, strategies targeting myofibroblast to be a quiescent state may be an effective way for antihypertrophic scar therapy. Graphene quantum dots (GQDs), a novel zero-dimensional and carbon-based nanomaterial, have recently garnered significant interest in nanobiomedicine, owing to their excellent biocompatibility, tunable photoluminescence, and superior physiological stability. Although multiple nanoparticles have been used to alleviate hypertrophic scars, a GQD-based therapy has not been reported. Our in vivo studies showed that GQDs exhibited significant antiscar efficacy, with scar appearance improvement, collagen reduction and rearrangement, and inhibition of myofibroblast overproliferation. Further in vitro experiments revealed that GQDs inhibited α-SMA expression, collagen synthesis, and cell proliferation and migration, inducing myofibroblasts to become quiescent fibroblasts. Mechanistic studies have demonstrated that the effect of GQDs on myofibroblast proliferation blocked cell cycle progression by disrupting the cyclin-CDK-E2F axis. This study suggests that GQDs, which promote myofibroblast-to-fibroblast transition, could be a novel antiscar nanomedicine for the treatment of hypertrophic scars and other types of pathological fibrosis.

Regulation of myofibroblast dedifferentiation in pulmonary fibrosis

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.

Delivery technologies for therapeutic targeting of fibronectin in autoimmunity and fibrosis applications

Fibronectin (FN) is a critical component of the extracellular matrix (ECM) contributing to various physiological processes, including tissue repair and immune response regulation. FN regulates various cellular functions such as adhesion, proliferation, migration, differentiation, and cytokine release. Alterations in FN expression, deposition, and molecular structure can profoundly impact its interaction with other ECM proteins, growth factors, cells, and associated signaling pathways, thus influencing the progress of diseases such as fibrosis and autoimmune disorders. Therefore, developing therapeutics that directly target FN or its interaction with cells and other ECM components can be an intriguing approach to address autoimmune and fibrosis pathogenesis.