Peritendinous adhesion formation and tendon re-rupture are prevalent clinical complications following tendon repair surgery. The key to reducing adhesions and enhancing the biomechanical strength of injured tendons lies in suppressing inflammation and extrinsic fibroblast activation while promoting intrinsic tenocyte proliferation. However, as tenocytes are inherently a type of fibroblast, it remains challenging for a single drug to reduce adhesion and improve tendon strength simultaneously. To address this challenge, a Janus hydrogel was designed for spatiotemporal programmed drug delivery specifically tailored to Achilles tendon repair. The outer layer of the Janus hydrogel rapidly releases melatonin (MT) via poly(N-acryloyl alaninamide) (PNAAA), effectively suppressing inflammation and extrinsic fibroblast activation. The inner layer gel, formed by thiol-modified gelatin (GelSH) and norbornene-modified hyaluronic acid (HANB), incorporates protein-binding AAc-NHS and gradually releases platelet-derived growth factor-BB (PDGF-BB), thereby promoting tenocyte proliferation. In the rat Achilles tendon injury model, the spatiotemporal programmed drug delivery Janus hydrogel successfully reduced adhesion while enhancing tendon healing strength. This work promoted Achilles tendon repair by meeting the distinct spatiotemporal therapeutic needs. STATEMENT OF SIGNIFICANCE: Melatonin may inhibit fibroblast proliferation and differentiation via the PI3K/AKT pathway, whereas PDGF-BB promotes tenocyte proliferation and differentiation through the same pathway. Consequently, the effects of these two drugs on fibroblasts and tenocytes may be conflicting. In this study, the programmed drug delivery Janus hydrogel was designed to match the different stages of tendon repair and achieved staggered release of melatonin and PDGF-BB. Melatonin@PNAAA primarily targets the extrinsic healing pathway, focusing on inflammatory cells during the inflammatory phase and fibroblasts during the proliferative phase. PDGF-BB@SHNB mainly targets intrinsic healing pathway, focusing on tenocytes during the proliferative phase and collagen synthesis during the remodeling phase. This spatiotemporal delivery system alleviates adhesion while promoting tendon healing.

Stem cells as therapy is currently a well-established scientific research topic. Poor maintenance and survival of cells supplied to the damaged tissue are barriers to improving the efficacy of regenerative medicine. Antioxidants such as L-carnitine are used to promote cell survival and maintenance properties. This study aims to assess the effects of L-carnitine on albino rat gingiva-derived mesenchymal stem cells proliferation.

Rat gingiva-derived mesenchymal stem cells were isolated and exposed to 0, 1, 3, and 10 Mm of L-carnitine. Flow cytometry was then utilized to measure gene and protein expression levels for CD90, CD105, CD45, and CD19. The MTT test was used to examine the proliferation of cells. The proportion of apoptosis was determined using the Annexin V/PI technique. Cell cycle investigations to assess cells and identify the percentages of cells in the G0/G1, S, and G2/M phases. Expression of TGF-β gene has been evaluated using Real time‑PCR analysis.

The results showed that gingiva-derived mesenchymal stem cells, including CD90 and CD105, consistently showed positive immunostaining, whereas CD45 and CD19 were weakly positive or negative. Concentration-dependent increase of growth proliferation, more rapid proliferation of the cells treated with the highest L-carnitine concentration (10 mM) after 72 h (0.934 ± 0.063). Cells treated with 10 mM L-carnitine showed considerably decreased percentages of necrotic (2.38 ± 0.55), late (1.23 ± 0.90), early apoptotic cells (1.18 ± 0.13), and increased the percentage of viable cells (95.13 ± 1.61).

Our findings suggest that adding L-carnitine to gingiva-derived mesenchymal stem cells during expansion enables efficient and viable cell production.

This paper examines the physiological changes in spastic muscles contributing to spasticity and muscle stiffness, focusing on the underlying mechanisms and their clinical implications. Spasticity, which is prevalent in neurological conditions such as multiple sclerosis, cerebral palsy, spinal cord injury, stroke, and traumatic brain injury, is characterized by disordered sensorimotor control and often results in increased muscle stiffness and resistance to movement. Recent developments in the understanding of spasticity suggest the importance of architectural changes in muscles that may contribute to increased passive resistance, potentiate reflex mechanisms, and progression to fibrosis, with hyaluronan (HA), a glycosaminoglycan, playing a pivotal in modulating the properties of the muscle extracellular matrix (ECM). The hyaluronan hypothesis of muscle stiffness postulates that the accumulation and biophysical alteration of HA in the ECM of muscle increases its viscosity, resulting in increased passive mechanical resistance. This is turn mayincrease muscle sensitivity to stretch, potentiating spasticity, and lead to cellular differentiation of myofibroblasts to fibroblasts ultimately leading to fibrosis and contracture. A deeper understanding of HA's role in ECM dynamics offers promising avenues for novel treatments aimed at mitigating stiffness and preventing long-term disability in patients with spasticity.

Pulmonary fibrosis is a chronic progressive fibrosing interstitial lung disease of unknown cause, characterized by excessive deposition of extracellular matrix, leading to irreversible decline in lung function and ultimately death due to respiratory failure and multiple complications. The Sirtuin family is a group of nicotinamide adenine dinucleotide (NAD+) -dependent histone deacetylases, including SIRT1 to SIRT7. They are involved in various biological processes such as protein synthesis, metabolism, cell stress, inflammation, aging and fibrosis through deacetylation. This article reviews the complex molecular mechanisms of the poorly studied SIRT3, SIRT6, and SIRT7 subtypes in lung fibrosis and the latest research progress in targeting them to treat lung fibrosis.

Bronchopulmonary dysplasia (BPD) is a chronic lung disorder predominantly affecting preterm infants. Oxygen therapy, a common treatment for BPD, often leads to hyperoxia-induced pulmonary damage, particularly targeting alveolar epithelial cells (AECs). Crucially, disrupted lung epithelium-fibroblast interactions significantly contribute to BPD's pathogenesis. Previous studies on interleukin-11 (IL-11) in lung diseases have yielded conflicting results. Recent research, however, highlights IL-11 as a key regulator of fibrosis, stromal inflammation, and epithelial dysfunction. Despite this, the specific role of IL-11 in BPD remains underexplored. Our transcriptome analysis of normal and hyperoxia-exposed murine lung tissues revealed an increased expression of IL-11 RNA. This study aimed to investigate IL-11's role in modulating the disrupted interactions between AECs and fibroblasts in BPD.

BPD was modeled in vivo by exposing C57BL/6J neonatal mice to hyperoxia. Histopathological changes in lung tissue were evaluated with hematoxylin-eosin staining, while lung fibrosis was assessed using Masson staining and immunohistochemistry (IHC). To investigate IL-11's role in pulmonary injury contributing to BPD, IL-11 levels were reduced through intraperitoneal administration of IL-11RαFc in hyperoxia-exposed mice. Additionally, MLE-12 cells subjected to 95% oxygen were collected and co-cultured with mouse pulmonary fibroblasts (MPFs) to measure α-SMA and Collagen I expression levels. IL-11 levels in the supernatants were quantified using an enzyme-linked immunosorbent assay (ELISA).

Both IHC and Masson staining revealed that inhibiting IL-11 expression alleviated pulmonary fibrosis in neonatal mice induced by hyperoxia, along with reducing the expression of fibrosis markers α-SMA and collagen I in lung tissue. In vitro analysis showed a significant increase in IL-11 levels in the supernatant of MLE-12 cells treated with hyperoxia. Silencing IL-11 expression in MLE-12 cells reduced α-SMA and collagen I concentrations in MPFs co-cultured with the supernatant of hyperoxia-treated MLE-12 cells. Additionally, ERK inhibitors decreased α-SMA and collagen I levels in MPFs co-cultured with the supernatant of hyperoxia-treated MLE-12 cells. Clinical studies found increased IL-11 levels in tracheal aspirates (TA) of infants with BPD.

This research reveals that hyperoxia induces IL-11 secretion in lung epithelium. Additionally, IL-11 derived from lung epithelium emerged as a crucial mediator in myofibroblast differentiation via the ERK signaling pathway, highlighting its potential therapeutic value in BPD treatment.

Tendon is a dense connective tissue that transmits contraction forces from skeletal muscles to bones. Adult tendon injury is a significant clinical problem because it occurs frequently with a high recurrence rate, and damaged tendon is rarely restored to full function. The main barrier to improving recovery outcomes is our incomplete understanding of the molecular mechanisms underlying the biological alterations following tendon injury in vivo. In this review, we specifically highlight the cellular dynamism of fibrotic tendon wound healing and the roles of mechanical loading. In particular, we document how tendon stem/progenitor cells expressing the tendon-specific transcription factor Scleraxis (Scx) play a role in fibrotic tendon wound healing, and describe novel experimental systems such as lineage cell tracing and single-cell analysis, both of which can shed light on tendon cell behavior and fate decisions during the tendon wound healing process.

Idiopathic pulmonary fibrosis (IPF) and other progressive fibrotic interstitial lung diseases have limited treatment options. Fibroblasts are key effector cells that sense matrix stiffness through conformation changes in mechanically sensitive receptors, leading to activation of downstream profibrotic pathways. Here, the role of Piezo2, a mechanosensitive ion channel, in human and mouse lung fibrosis, and its function in myofibroblast differentiation in primary human lung fibroblasts (HLFs) was investigated. Human samples from patients with IPF and mouse tissue from bleomycin-induced pulmonary fibrosis were assessed. Primary HLFs from nonfibrotic donors were grown on substrates of different stiffness to induce myofibroblast differentiation and treated with a Piezo2 inhibitor. Piezo2 expression was up-regulated in tissue from patients with IPF and in fibrotic mouse lung tissue. Additionally, analysis of published single-cell RNA-sequencing data showed that Piezo2 was expressed in the profibrotic collagen triple helix repeat containing 1 (Cthrc1)+ fibroblast subpopulation. Myofibroblast differentiation was increased in HLFs grown on substrates with fibrotic levels of stiffness compared with that seen in softer substrates. Piezo2 inhibition reduced stiffness-induced expression α-smooth muscle actin and fibronectin in HLFs. Piezo2 expression was elevated in fibrotic lung disease in both patients and rodents, and its presence was key in the differentiation of fibroblasts to the profibrotic myofibroblasts. Blocking Piezo2 may play a key role in fibrosis and, thus, be a novel therapeutic approach to treat pulmonary fibrosis.

Cardiotoxicity represents a critical challenge in cancer therapy, particularly in the treatment of thoracic tumors, such as lung cancer and lymphomas, as well as breast cancer. These malignancies stand out for their high prevalence and the widespread use of cardiotoxic treatments, such as chemotherapy, radiotherapy, and immunotherapy. This work underscores the importance of preclinical models in uncovering the mechanisms of cardiotoxicity and developing targeted prevention and mitigation strategies. In vitro models provide valuable insights into cellular processes, enabling the observation of changes in cell viability and function following exposure to various drugs or ionizing radiation. Complementarily, in vivo animal models offer a broader perspective, allowing for evaluating of both short- and long-term effects and a better understanding of chronic toxicity and cardiac diseases. By integrating these approaches, researchers can identify potential mechanisms of cardiotoxicity and devise effective prevention strategies. This analysis highlights the central role of preclinical models in advancing knowledge of cardiotoxic effects associated with common therapeutic regimens for thoracic and breast cancers.

Fibrosis is a pathophysiological mechanism involved in chronic and progressive diseases that results in excessive tissue scarring. Diseases associated with fibrosis include metabolic dysfunction-associated steatohepatitis (MASH), inflammatory bowel diseases (IBDs), chronic kidney disease (CKD), idiopathic pulmonary fibrosis (IPF) and systemic sclerosis (SSc), which are collectively responsible for substantial morbidity and mortality. Although a few drugs with direct antifibrotic activity are approved for pulmonary fibrosis and considerable progress has been made in the understanding of mechanisms of fibrosis, translation of this knowledge into effective therapies continues to be limited and challenging. With the aim of assisting developers of novel antifibrotic drugs, this Review integrates viewpoints of biologists and physician-scientists on core pathways involved in fibrosis across organs, as well as on specific characteristics and approaches to assess therapeutic interventions for fibrotic diseases of the lung, gut, kidney, skin and liver. This discussion is used as a basis to propose strategies to improve the translation of potential antifibrotic therapies.

Radiation therapy (RT) is fundamental to the fight against cancer because of its exceptional ability to target and destroy cancer cells. However, conventional radiation therapy can significantly affect the adjacent normal tissues, leading to fibrosis, inflammation, and decreased organ function. This tissue damage not only reduces the quality of life but also prevents the total elimination of cancer. The transformation of epithelial cells into mesenchymal-like cells, termed epithelial-mesenchymal transition (EMT), is essential for processes such as fibrosis, embryogenesis, and wound healing. Conventional radiation therapy increases the asymmetric activation of fibrotic and inflammatory pathways, and the resulting chronic fibrotic changes and organ dysfunction are linked to radiation-induced epithelial-mesenchymal transition. Recent advances in radiation therapy, namely flash radiation therapy (FLASH-RT), have the potential to widen the therapeutic index. Radiation delivered by FLASH-RT at very high dose rates (exceeding 40 Gy/s) can protect normal tissue from radiation-induced damage, a phenomenon referred to as the "FLASH effect". Preclinical studies have demonstrated that FLASH-RT successfully inhibits processes associated with fibrosis and epithelial-mesenchymal transition, mitigates damage to normal tissue, and enhances regeneration. Three distinct types of EMT have been identified: type-1, associated with embryogenesis; Type-2, associated with injury potential; and type-3, related with cancer spread. The regulation of EMT via pathways, including TGF-β/SMAD, WNT/β-catenin, and NF-κB, is essential for radiation-induced tissue remodelling. This study examined radiation-induced EMT, TGF-β activity, multiple signalling pathways in fibrosis, and the potential of FLASH-RT to reduce tissue damage. FLASH-RT is a novel approach to treat chronic tissue injury and fibrosis post-irradiation by maintaining epithelial properties and regulating mesenchymal markers including vimentin and N-cadherin. Understanding these pathways will facilitate the development of future therapies that can alleviate fibrosis, improve the efficacy of cancer therapy, and improve the quality of life of patients.

Exosomal non-coding RNAs (ncRNAs), including miRNAs, lncRNAs, and circRNAs, have emerged as crucial modulators in cellular signaling, influencing wound healing processes. Stem cell-derived exosomes, which serve as vehicles for these ncRNAs, show remarkable therapeutic potential due to their ability to modulate wound healing stages, from initial inflammation to collagen formation. These ncRNAs act as molecular signals, regulating gene expression and protein synthesis necessary for cellular responses in healing. Wound healing is a complex, staged process involving inflammation, hemostasis, fibroblast proliferation, angiogenesis, and tissue remodeling. Stem cell-derived exosomal ncRNAs enhance these stages by reducing excessive inflammation, promoting anti-inflammatory responses, guiding fibroblast and keratinocyte maturation, enhancing vascularization, and ensuring organized collagen deposition. Their molecular cargo, particularly ncRNAs, specifically targets pathways to aid chronic wound repair and support scarless regeneration. This review delves into the unique composition and signaling roles of Stem cell-derived exosomes and ncRNAs, highlighting their impact across wound healing stages and their potential as innovative therapeutics. Understanding the interaction between exosomal ncRNAs and cellular signaling pathways opens new avenues in regenerative medicine, positioning Stem cell-derived exosomes and their ncRNAs as promising molecular-level interventions in wound healing.

Systemic sclerosis (SSc) is an autoimmune disease characterized by vascular endothelial dysfunction and damage, immune dysregulation and fibrosis. Endothelial mesenchymal transition (EndoMT) has been implicated in the skin fibrosis of SSc. Many studies have demonstrated that janus kinase type2 (JAK2) inhibitor can alleviate skin fibrosis in both SSc patients and bleomycin (BLM)-induced mouse models of SSc. However, the potential therapeutic effect of JAK2 inhibitor on EndoMT in SSc skin, along with the underlying molecular mechanisms, remains unexplored.

To investigate the effects of JAK2 inhibitor on the EndoMT in SSc skin and to elucidate the associated molecular mechanisms.

Wild-type female C57BL/6 mice were divided into several groups to assess the effects of JAK2 inhibitor on EndoMT through H&E staining, masson staining, immunofluorescence and single-cell RNA-sequencing (scRNA-seq). Cultured human umbilical vein endothelial cells (HUVECs) were used to explore the mechanism of action of JAK2 inhibitor on EndoMT using immunofluorescence, quantitative RT-PCR, RNA sequencing and western blot.

JAK2 inhibition improved skin fibrosis, reduced CD31/α-SMA co-localisation and the number of EndoMT-activated vascular endothelial cells in bleomycin-induced SSc mice. Treatment of HUVECs with TGF-β or BLM led to a myofibroblast-like morphology and markers, along with downregulation of endothelial cell features, which were reversed following JAK2 inhibition. The activation of the PI3K/Akt/mTOR pathway was involved in EndoMT in HUVECs induced by TGF-β/BLM, and this activation was attenuated by JAK2 inhibition.

JAK2 inhibitor may serve as an effective treatment for EndoMT in SSc, potentially through modulation of the PI3K/Akt/mTOR signaling pathway.

The non-HDL-C to HDL-C ratio (NHHR) is a dependable lipid marker linked to atherosclerotic traits. This study examines the potential relationship between NHHR and both metabolic dysfunction-associated steatotic liver disease (MASLD) and advanced liver fibrosis.

This study investigated the relationship between NHHR levels and both MASLD and advanced liver fibrosis using data from the 2017-2020 National Health and Nutrition Examination Survey (NHANES) in the United States. First, we conducted a baseline characteristics analysis of the population based on NHHR quartiles. Second, we employed multivariable weighted linear regression models to examine the associations between NHHR and MASLD, as well as advanced liver fibrosis. Third, we utilized restricted cubic splines (RCS) to assess potential non-linear relationships. Fourth, we performed subgroup analyses. Finally, ROC curve analysis was conducted to evaluate the effectiveness of NHHR.

In the main analysis, this study included a total of 9,864 participants. Following multivariable logistic regression and comprehensive adjustments, elevated NHHR levels in the Q3 and Q4 groups were significantly linked to MASLD, with odds ratios of 1.59 (95% CI: 1.20-2.11) and 1.83 (95% CI: 1.40-2.39), respectively (P for trend < 0.0001). Elevated NHHR levels in the Q2 and Q3 groups remained significantly linked to a decreased risk of advanced liver fibrosis, with odds ratios of 0.61 (95% CI 0.40-0.94, P = 0.03) and 0.64 (95% CI 0.47-0.89, P = 0.01), respectively. RCS analysis revealed a U-shaped nonlinear association between NHHR and both MASLD (P = 0.000; P for nonlinear = 0.029) and advanced liver fibrosis (P = 0.0001; P for nonlinear = 0.000). In the subgroup analysis, we found that this relationship was significant only in certain subgroups. The ROC curve analysis revealed that NHHR exhibited the best predictive performance for diagnosing MASLD based on the fatty liver index (FLI). The optimal cutoff point for NHHR in predicting MASLD using FLI was determined to be 2.476, with sensitivity and specificity values of 0.589 and 0.698, respectively.

NHHR may serve as a predictive marker for MASLD and advanced liver fibrosis, highlighting its potential significance in risk assessment and prevention strategies.

Myocardial fibrosis is one of the pathological characteristics of advanced diabetic cardiomyopathy (DCM) and serves as the strong evidence of poor prognosis. Among them, the transdifferentiation of cardiac fibroblasts (CFs) may play a crucial role in the development of myocardial fibrosis in DCM. Tinglu Yixin granule (TLYXG) has been clinically used for many years and can significantly improve cardiac function of patients with DCM. However, the effect of TLYXG on myocardial fibrosis in DCM remains unknown, and the underlying mechanisms of its efficacy have yet to be fully understood.

This study aimed to investigate the impact and underlying mechanism of TLYXG on myocardial fibrosis in diabetes mice.

The bioactive compounds in TLYXG were identified using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). The potential mechanism of TLYXG in treating DCM was predicted using network pharmacology combined with molecular docking and protein-protein docking. The mice model of type 2 diabetes were established by intraperitoneal injection of streptozotocin (STZ) and the high-fat diet (HFD). Indicators of pancreatic islet function, lipids, oxidative stress, and inflammatory factors were tested using kits. Cardiac function was assessed in diabetic mice using echocardiography. Histologic staining was performed to evaluate myocardial hypertrophy and fibrosis. Mechanistically, the hypothesis was tested through rescue experiments. The expression levels of transient receptor potential channel 6 (TRPC6), transforming growth factor-β1 (TGF-β1), collagen I (COL-I) and alpha-smooth muscle actin (α-SMA), along with the mRNA and phosphorylation levels of SMAD family member 3 (Smad3) and protein 38 mitogen-activated protein kinase (p38 MAPK), were assessed using quantitative RT-qPCR, Western blot, immunohistochemistry, and immunofluorescence. Neonatal lactating mice were used to extract primary CFs for vitro experiments. Scratch and transwell assays were conducted to assess CFs migration and invasion abilities. Western blot and immunofluorescence were used to evaluate the expression levels of CFs transdifferentiation markers COL-I and α-SMA.

A total of 168 active ingredients were detected in TLYXG based on UPLC-MS and databases. Network pharmacology indicated that TLYXG could improve DCM through inflammatory mediator regulation of TRP channels, TGF-beta signaling pathway, and MAPK signaling pathway. ELISA results showed that TLYXG could ameliorate metabolic levels, inflammation, and oxidative stress in diabetic mice. Echocardiography suggested that TLYXG improved cardiac systolic and diastolic dysfunction in diabetic mice. Histological analysis revealed that TLYXG alleviated myocardial fibrosis in diabetes mice. Additionally, molecular docking analysis indicated strong binding activity between the main active ingredients of TLYXG and TRPC6 of the TRP family. At the molecular level, TLYXG reduced the mRNA and protein expression levels of TRPC6 and TGF-β1 and inhibited the mRNA and phosphorylation levels of Smad3 and p38 MAPK. Furthermore, TLYXG inhibited CFs migration and invasion, and reduced the expression levels of the CFs transdifferentiation markers COL-I and α-SMA.

TLYXG inhibited the proliferation, migration, invasion and transdifferentiation of CFs by suppressing TGF-β1/Smad3/p38 MAPK signaling through down-regulation of TRPC6, thereby ameliorating myocardial fibrosis in diabetes mice.

Macrophages are innate immune cells present in all tissues and play an important role in almost all aspects of the biology of living organisms. Extracellular vesicles (EVs) are released by cells and transport their contents (micro RNAs, mRNA, proteins, and long noncoding RNAs) to nearby or distant cells for cell-to-cell communication. Numerous studies have shown that macrophage-derived extracellular vesicles (M-EVs) and their contents play an important role in a variety of diseases and show great potential as biomarkers, therapeutics, and drug delivery vehicles for diseases. This article reviews the biological functions and mechanisms of M-EVs and their contents in chronic non-communicable diseases such as cardiovascular diseases, metabolic diseases, cancer, inflammatory diseases and bone-related diseases. In addition, the potential application of M-EVs as drug delivery systems for various diseases have been summarized.

Prostate fibrosis contributes to lower urinary tract dysfunction (LUTD). To develop targeted treatments for prostate fibrosis, it is necessary to identify the cell types and molecular pathways required for collagen production. We used a genetic approach to label and track potential collagen-producing cell lineages in mouse prostate through a round of Escherichia coli UTI89-mediated prostate inflammation. E. coli increased collagen density and production in Gli1+, S100a4+, Lyz2+ and Cd2+ cell lineages, but not in Myh11+ or Srd5a2+ cell lineages, in the mouse prostate. Molecular phenotyping revealed GLI1+LYZ+S100A4+ cells (fibrocytes) in histologically inflamed human prostate. These fibrocytes colocalized with regions of increased collagen in men with LUTD. Fibrocyte recruitment and collagen synthesis was impaired in Ccr2 null mice but restored by allotransplantation of Rosa-GFP donor bone marrow-derived cells. These results suggest that bone marrow-derived fibrocytes are a mediator of prostatic collagen accumulation.

Skin wound repair involves myofibroblasts crucial for tissue integrity. This study utilized single-cell RNA sequencing to explore myofibroblast diversity in various wound healing scenarios. Analysis of 89,148 cells from skin ulcers, keloids, and normal scars identified 13 cell clusters. Myofibroblast subcluster analysis unveiled 11 subsets, with subclusters 1 and 9 predominant in ulcers. Subcluster 1 exhibited heightened matrix metalloproteinase expression and involvement in bacterial response and angiogenesis, crucial in inflammation. Tissue validation confirmed subcluster 1 significance., while animal models supported upregulated CA12, TDO2, and IL-7R in chronic ulcers. These findings illuminate myofibroblast heterogeneity and their impact on wound healing, offering insights into potential therapeutic targets.

Despite recent advances in the treatment of thyroid eye disease thyroid-related eye disease (TED), marked gaps remain in our understanding of the underlying molecular mechanisms, particularly concerning the insulin-like growth factor-1 receptor (IGF-1R) pathway. To dissect the pathophysiology of TED, we used single-nucleus RNA-Seq to analyze orbital fat specimens from both patients with TED and matched individuals acting as controls. The analysis demonstrated a marked increase in the proportion of fibroblasts transitioning to adipogenesis in the orbital fat of patients with TED compared with that in control patients. This was associated with diverse alterations in immune cell composition. Significant alterations in the IGF-1R signaling pathway were noted between TED specimens and those from control patients, indicating a potential pathological mechanism driven by IGF-1R signaling abnormalities. Additionally, our data showed that linsitinib, a small-molecule inhibitor of IGF-1R, effectively reduced adipogenesis in TED orbital fibroblasts in vitro, suggesting its potential utility as a therapeutic agent. Our findings reveal that, beyond immune dysfunction, abnormal IGF-1R signaling leading to enhanced adipogenesis is a crucial pathogenic mechanism in TED.

Oral submucous fibrosis (OSF) is a precancerous condition that poses substantial health risks. OSF is mainly caused by betel nut chewing behavior, but its pathogenesis is still unclear and there is no effective treatment strategy. The transformation of fibroblasts to myofibroblast is the key pathological change in the development of OSF. We isolated fibroblasts from human oral mucosa and induced them into myofibroblasts by arecoline, during which autophagy was significantly activated. Here, we found that adipose-derived stem cell exosomes (ADSCs-EXO) could inhibit autophagy to regulate myofibroblast phenotype, and transcriptome sequencing analysis suggested that this process is closely related to the TGF-β pathway. The interplay between autophagy and TGF-β pathway was examined through modulation the two with autophagy activators and inhibitors, TGF-β receptor activators and inhibitors. Results showed that in vitro, the TGF-β/Smad2 pathway augmented autophagy and promoted myofibroblast transformation. The transcriptome information of ADSCs-EXO showed that it contains a large number of miRNAs. Among them, miR-125a-5p could target Smad2. In vivo, injection of ADSCs-EXO alleviated OSF in mice, during which TGF-β and autophagy signals were inhibited. We suggested that ADSCs-EXO could inhibit myofibroblast transformation via inhibiting autophagy through TGF-β/Smad2 axis in OSF, providing new insights for autophagy-based intervention strategies.

Myofibroblast differentiation, characterized by accumulation of cytoskeletal and extracellular matrix proteins by fibroblasts, is a key process in wound healing and pathogenesis of tissue fibrosis. Transforming growth factor-β (TGF-β) is the most powerful known driver of myofibroblast differentiation. TGF-β signals through transmembrane receptor serine/threonine kinases that phosphorylate Smad transcription factors (Smad2/3) leading to activation of transcription of target genes. Heterotrimeric G proteins mediate distinct signaling from seven-transmembrane G protein coupled receptors, which are not known to be linked to Smad activation. We tested whether G protein signaling plays any role in TGF-β-induced myofibroblast differentiation, using primary cultured human lung fibroblasts. Activation of Gαs by cholera toxin blocked TGF-β-induced myofibroblast differentiation without affecting Smad2/3 phosphorylation. Neither inhibition of Gαi by pertussis toxin nor siRNA-mediated combined knockdown of Gαq and Gα11 had a significant effect on TGF-β-induced myofibroblast differentiation. In contrast, combined knockdown of Gα12 and Gα13 significantly inhibited TGF-β-stimulated expression of myofibroblast marker proteins (collagen-1, fibronectin, smooth-muscle α-actin), with siGα12 being significantly more potent than siGα13. Mechanistically, combined knockdown of Gα12 and Gα13 resulted in substantially reduced phosphorylation of Smad2 and Smad3 in response to TGF-β, which was accompanied by a significant decrease in the expression of TGF-β receptors (TGFBR1, TGFBR2) and of Smad3. Thus, our study uncovers a novel role of Gα12/13 proteins in the control of TGF-β signaling and myofibroblast differentiation.

Organ fibrosis is a pathological process characterized by the inability of normal tissue cells to regenerate sufficiently to meet the dynamic repair demands of chronic injury, resulting in excessive extracellular matrix deposition and ultimately leading to organ dysfunction. Despite the increasing depth of research in the field of organ fibrosis and a more comprehensive understanding of its pathogenesis, effective treatments for fibrosis-related diseases are still lacking. Melatonin, a neuroendocrine hormone synthesized by the pineal gland, plays a crucial role in regulating biological rhythms, sleep, and antioxidant defenses. Recent studies have shown that melatonin may have potential in inhibiting organ fibrosis, possibly due to its functions in anti-oxidative stress, anti-inflammation, remodeling the extracellular matrix (ECM), inhibiting epithelial-mesenchymal transition (EMT), and regulating apoptosis, thereby alleviating fibrosis. This review aims to explore the therapeutic potential of melatonin in fibrosis-related human diseases using findings from various in vivo and in vitro studies. These discoveries should provide important insights for the further development of new drugs to treat fibrosis.

Cellular contractility, migration, and extracellular matrix (ECM) mechanics are critical for a wide range of biological processes including embryonic development, wound healing, tissue morphogenesis, and regeneration. Even though the distinct response of cells near the tissue periphery has been previously observed in cell-laden microtissues, including faster kinetics and more prominent cell-ECM interactions, there are currently no models that can fully combine coupled surface and bulk mechanics and kinetics to recapitulate the morphogenic response of these constructs. Mailand et al. (Biophys J 117(5):975-986, 2019) had shown the importance of active elastocapillarity in cell-laden microtissues, but modeling the distinct mechanosensitive migration of cells on the periphery and the interior of highly deforming tissues has not been possible thus far, especially in the presence of active elastocapillary effects. This paper presents a framework for understanding the interplay between cellular contractility, migration, and ECM mechanics in dynamically morphing soft tissues accounting for distinct cellular responses in the bulk and the surface of tissues. The major novelty of this approach is that it enables modeling the distinct migratory and contractile response of cells residing on the tissue surface and the bulk, where concurrently the morphing soft tissues undergo large deformations driven by cell contractility. Additionally, the simulation results capture the changes in shape and cell concentration for wounded and intact microtissues, enabling the interpretation of experimental data. The numerical procedure that accounts for mechanosensitive stress generation, large deformations, diffusive migration in the bulk and a distinct mechanism for diffusive migration on deforming surfaces is inspired from recent work on bulk and surface poroelasticity of hydrogels involving elastocapillary effects, but in this work, a two-field weak form is proposed and is able to alleviate numerical instabilities that were observed in the original method that utilized a three-field mixed finite element formulation.

The intricate expression patterns and oncogenic attributes of COL11A1 across different cancer types remain largely elusive. This study used several public databases (TCGA, GTEx, and CCLE) to investigate the pan-cancer landscape of COL11A1 expression, its prognostic implications, interplay with the immune microenvironment, and enriched signaling cascades. Concurrently, western blot analyses were performed to verify COL11A1 expression in lung adenocarcinoma (LUAD) cell lines and clinical samples. In addition, COL11A1 knockout cell lines were generated to scrutinize the functional consequences of COL11AI expression on cancer cell behavior by use MTT, colony formation, and scratch wound healing assays. A comprehensive database investigation revealed that COL11A1 was upregulated in a majority of tumor tissues and its expression was highly correlated with a patient's prognosis. Notably, genetic alterations in COL11A1 predominantly occurred as mutations, while its DNA methylation status inversely mirrored gene expression levels across multiple promoter regions. Our findings suggest that COL11A1 helps to modulate the tumor immune landscape and potentially acts through the epithelial-mesenchymal transition (EMT) pathway to exert its oncogenic function. Western blot analyses further substantiated the specific upregulation of COL11A1 in LUAD cell lines and tissues, suggesting a close association with the EMT process. Ablation of COL11A1 in cancer cells significantly reduced their proliferative, clonogenic, and migratory abilities, underscoring the functional significance of COL11A1 in tumor cell behavior. Collectively, this research revealed the prevalent overexpression of COL11A1 in pan-cancer tissues, its profound prognostic and microenvironmental correlations, and the mechanistic underpinnings of its tumor-promoting effects as mediated via EMT signaling. Our findings suggest that COL11A1 could serve as a prognostic and diagnostic biomarker and therapeutic target for cancer.

The aryl hydrocarbon receptor (AHR) is a pivotal nuclear receptor involved in mediating cellular responses to a wide range of environmental pollutants and endogenous ligands. AHR plays a central role in regulating essential physiological processes, including xenobiotic metabolism, immune response modulation, cell cycle control, tumorigenesis, and developmental events. Recent studies have identified AHR as a critical mediator and a potential therapeutic target in the pathogenesis of ocular diseases. This review provides a thorough analysis of the various functions of AHR signalling in the ocular environment, with a specific emphasis on its effects on the retina, retinal pigment epithelium (RPE), choroid, and cornea. We provide a detailed discussion on the molecular mechanisms through which AHR integrates environmental and endogenous signals, influencing the development and progression of age-related macular degeneration (AMD), retinitis pigmentosa, uveitis, and other major ocular disorders. Furthermore, we evaluate the therapeutic potential of modulating AHR activity through novel ligands and agonists as a strategy for treating eye diseases. Understanding the molecular mechanisms of AHR in ocular tissues may facilitate the development of AHR-targeted therapies, which is crucial for addressing the pressing clinical demand for novel treatment strategies in ocular diseases.

Conventional wound approximation devices, including sutures, staples, and glues, are widely used but risk of wound dehiscence, local infection, and scarring can be exacerbated in these approaches, including in diabetic and obese individuals. This study reports the efficacy and quality of tissue repair upon photothermal sealing of full-thickness incisional skin wounds using silk fibroin-based laser-activated sealants (LASEs) containing copper chloride salt (Cu-LASE) or silver nanoprisms (AgNPr-LASE), which absorb and convert near-infrared (NIR) laser energy to heat. LASE application results in rapid and effective skin sealing in healthy, immunodeficient, as well as diabetic and obese mice. Although lower recovery of epidermal structure and function was seen with AgNPr-LASE sealing, likely because of the hyperthermia induced by laser and presence of this material in the wound space, this approach resulted in higher enhancement in recovery of skin biomechanical strength compared to sutures and Cu-LASEs in diabetic, obese mice. Histological and immunohistochemical analyses revealed that AgNPr-LASEs resulted in significantly lower neutrophil migration to the wound compared to Cu-LASEs and sutures, indicating a more muted inflammatory response. Cu-LASEs resulted in local tissue toxicity likely because of effects of copper ions as manifested in the form of a significant epidermal gap and a 'depletion zone', which was a region devoid of viable cells proximal to the wound. Compared to sutures, LASE-mediated sealing, in later stages of healing, resulted in increased angiogenesis and diminished myofibroblast activation, which can be indicative of lower scarring. AgNPr-LASE loaded with vancomycin, an antibiotic drug, significantly lowered methicillin-resistant Staphylococcus aureus (MRSA) load in a pathogen challenge model in diabetic and obese mice and also reduced post-infection inflammation of tissue compared to antibacterial sutures. Taken together, these attributes indicate that AgNPr-LASE demonstrated a more balanced quality of tissue sealing and repair in diabetic and obese mice and can be used for combating local infections, that can result in poor healing in these individuals.

Kidney fibrosis is a hallmark of chronic kidney diseases. Evidence shows that genetic variability and complement component 3 (C3) might influence tubulointerstitial fibrosis. Still, the role of renal C3 production in the epithelial-to-mesenchymal transition (EMT) and genetically determined fibrosis progression remains undiscovered. The kidneys of fibrosis-resistant C57Bl/6J (B6) and fibrosis-prone CBA/J (CBA) and BALB/cJ (BalbC) mice (n = 4-8/group) were subjected to unilateral ureteral obstruction (UUO) and analyzed after 1, 3, and 7 days, along with human focal glomerular sclerotic (FSGS) and healthy kidneys. Mouse primary tubular epithelial cells (PTECs) were investigated after 24 h of treatment with transforming growth factor β (TGFβ) or complement anaphylatoxin 3a (C3a) agonist (n = 4/group). UUO resulted in delayed kidney injury in fibrosis-resistant B6 mice, but very early renal C3 messenger RNA (mRNA) induction in fibrosis-prone CBA and BalbC mice, along with collagen I (Col1a1) and collagen III (Col3a1). CBA depicted the fastest fibrosis progression with the highest C3, lipocalin-2 (Lcn2), Tgfb1, and chemokine (C-C motif) ligand 2 (Ccl2) expression. Human FSGS kidneys depicted C3 mRNA over-expression and strong tubular C3 immunostaining. In PTECs, C3a agonist treatment induced pro-fibrotic early growth response protein 1 (EGR1) expression and the EMT, independent of TGFβ signaling. We conclude that de novo renal tubular C3 synthesis is associated with the genetically determined kidney fibrosis progression rate in mice and the pathogenesis of FSGS in humans. This tubular C3 overproduction can, through local pro-fibrotic effects, influence the progression of chronic kidney disease.

To examine disease and target engagement biomarkers in the RISE-SSc trial of riociguat in early diffuse cutaneous systemic sclerosis and their potential to predict the response to treatment.

Patients were randomized to riociguat (n = 60) or placebo (n = 61) for 52 weeks. Skin biopsies and plasma/serum samples were obtained at baseline and week 14. Plasma cyclic guanosine monophosphate (cGMP) was assessed using radio-immunoassay. α-Smooth muscle actin (αSMA) and skin thickness were determined by immunohistochemistry, mRNA markers of fibrosis by qRT-PCR in skin biopsies, and serum CXC motif chemokine ligand 4 (CXCL-4) and soluble platelet endothelial cell adhesion molecule-1 (sPECAM-1) by enzyme-linked immunosorbent assay.

By week 14, cGMP increased by 94 (78)% with riociguat and 10 (39)% with placebo (P < 0.001, riociguat vs placebo). Serum sPECAM-1 and CXCL-4 decreased with riociguat vs placebo (P = 0.004 and P = 0.008, respectively). There were no differences in skin collagen markers between the two groups. Higher baseline serum sPECAM-1 or the detection of αSMA-positive cells in baseline skin biopsies was associated with a larger reduction of modified Rodnan skin score from baseline at week 52 with riociguat vs placebo (interaction P-values 0.004 and 0.02, respectively).

Plasma cGMP increased with riociguat, suggesting engagement with the nitric oxide-soluble guanylate cyclase-cGMP pathway. Riociguat was associated with a significant reduction in sPECAM-1 (an angiogenic biomarker) vs placebo. Elevated sPECAM-1 and the presence of αSMA-positive skin cells may help to identify patients who could benefit from riociguat in terms of skin fibrosis.

Clinicaltrials.gov, NCT02283762.

Wound healing is a complex process involving multiple stages, including inflammation, proliferation, and remodeling. Effective wound management strategies are essential for accelerating healing and improving outcomes. The CELLADEEP patch, incorporating iontophoresis therapy and microneedle technology, was evaluated for its potential to enhance the wound healing process.

This study utilized a full-thickness skin defect model in Sprague-Dawley rats, researchers compared wound healing outcomes between rats treated with the CELLADEEP Patch and those left untreated. Various histological staining techniques were employed to examine and assess the wound healing process, such as H&E, MT and immunofluorescence staining. Furthermore, the anti-inflammatory and proliferative capabilities were further investigated using biochemical assays.

Macroscopic and microscopic analyses revealed that the CELLADEEP patch significantly accelerated wound closure, reduced wound width, and increased epidermal thickness and collagen deposition compared to an untreated group. The CELLADEEP patch decreased nitric oxide and reactive oxygen species levels, as well as pro-inflammatory cytokines IL-6 and TNF-α, indicating effective modulation of the inflammatory response. Immunofluorescence staining showed reduced markers of macrophage activity (CD68, F4/80, MCP-1) in the patch group, suggesting a controlled inflammation process. Increased levels of vimentin, α-SMA, VEGF, collagen I, and TGF-β1 were observed, indicating enhanced fibroblast activity, angiogenesis, and extracellular matrix production.

The CELLADEEP patch demonstrated potential in promoting effective wound healing by accelerating wound closure, modulating the inflammatory response, and enhancing tissue proliferation and remodeling. The CELLADEEP patch offers a promising non-invasive treatment option for improving wound healing outcomes.

Platelet-rich plasma (PRP), which is prepared by concentrating platelets in autologous blood, shows efficacy in chronic skin wounds via multiple growth factors. However, it exhibits heterogeneity across patients, leading to unstable therapeutic efficacy. Human induced pluripotent stem cell (iPSC)-derived megakaryocytes and platelets (iMPs) are capable of providing a stable supply, holding promise as materials for novel platelet concentrate-based therapies. In this context, we evaluated the effect of iMPs on wound healing and validated lyophilization for clinical applications.

The growth factors released by activated iMPs were measured. The effect of the administration of iMPs on human fibroblasts and human umbilical vein endothelial cells (HUVECs) was investigated in vitro. iMPs were applied to dorsal skin defects of diabetic mice to assess the wound closure rate and quantify collagen deposition and angiogenesis. Following the storage of freeze-dried iMPs (FD-iMPs) for three months, the stability of growth factors and their efficacy in animal models were determined.

Multiple growth factors that promote wound healing were detected in activated iMPs. iMPs specifically released FGF2 and exhibited a superior enhancement of HUVEC proliferation compared to PRP. Moreover, an RNA-seq analysis revealed that iMPs induce polarization to stalk cells and enhance ANGPTL4 gene expression in HUVECs. Animal studies demonstrated that iMPs promoted wound closure and angiogenesis in chronic wounds caused by diabetes. We also confirmed the long-term stability of growth factors in FD-iMPs and their comparable effects to those of original iMPs in the animal model.

Our study demonstrates that iMPs promote angiogenesis and wound healing through the activation of vascular endothelial cells. iMPs exhibited more effectiveness than PRP, an effect attributed to the exclusive presence of specific factors including FGF2. Lyophilization enabled the long-term maintenance of the composition of the growth factors and efficacy of the iMPs, therefore contributing to stable supply for clinical application. These findings suggest that iMPs provide a novel treatment for chronic wounds.

Macrophage-myofibroblast transformation (MMT) has emerged as a discovery in the field of fibrotic disease research. MMT is the process by which macrophages differentiate into myofibroblasts, leading to organ fibrosis following organ damage and playing an important role in fibrosis formation and progression. Recently, many new advances have been made in studying the mechanisms of MMT occurrence in fibrotic diseases. This article reviews some critical recent findings on MMT, including the origin of MMT in myofibroblasts, the specific mechanisms by which MMT develops, and the mechanisms and effects of MMT in the kidneys, lungs, heart, retina, and other fibrosis. By summarizing the latest research related to MMT, this paper provides a theoretical basis for elucidating the mechanisms of fibrosis in various organs and developing effective therapeutic targets for fibrotic diseases.

We aimed to investigate Piezo1 expression in myofibroblasts in symptomatic and asymptomatic patients undergoing carotid endarterectomy and its relationship with atherosclerotic plaque formation.

This cross-sectional study analyzed carotid plaques of 17 randomly selected patients who underwent carotid endarterectomy from May 2015 to August 2017. In total, 51 sections (the most stenotic lesion, and the sections 5-mm proximal and distal) stained with hematoxylin-eosin and elastica-Masson were examined. Immunohistochemistry was performed using antibodies to Piezo1. The Piezo1 score of a section was calculated semiquantitatively, averaged across 30 randomly selected myofibroblasts in the fibrous cap of the plaque.

Of 17 patients (mean age: 74.2 ± 7.1 years), 15 were men, 9 had diabetes mellitus, and 13 had hypertension. Symptomatic patients had higher mean Piezo1 score than asymptomatic patients (1.78 ± 0.23 vs 1.34 ± 0.17, p < .001). Univariate linear regression analyses suggested an association between plaque rupture, thin-cap fibroatheroma and microcalcifications and the Piezo1 score (p = .001, .008, and 0.003, respectively).

Increased Piezo1 expression of myofibroblasts may be associated with atherosclerotic carotid plaque instability. Further study is warranted to support this finding.

Macrophage-myofibroblast transformation (MMT) transforms macrophages into myofibroblasts in a specific inflammation or injury microenvironment. MMT is an essential biological process in fibrosis-related diseases involving the lung, heart, kidney, liver, skeletal muscle, and other organs and tissues. This process consists of interacting with various cells and molecules and activating different signal transduction pathways. This review deeply discussed the molecular mechanism of MMT, clarified crucial signal pathways, multiple cytokines, and growth factors, and formed a complex regulatory network. Significantly, the critical role of transforming growth factor-β (TGF-β) and its downstream signaling pathways in this process were clarified. Furthermore, we discussed the significance of MMT in physiological and pathological conditions, such as pulmonary fibrosis and cardiac fibrosis. This review provides a new perspective for understanding the interaction between macrophages and myofibroblasts and new strategies and targets for the prevention and treatment of MMT in fibrotic diseases.

Fibrosis is characterized by the aberrant deposition of extracellular matrix (ECM) due to dysregulated tissue repair responses, imposing a significant global burden on fibrosis-related diseases. Although alpha-smooth muscle actin (α-SMA/ACTA2)-expressing myofibroblasts are considered as key player in fibrogenesis, the origin of ECM-producing cells remains controversial. To address this issue, we integrated and analyzed large-scale single-cell transcriptomic datasets from patients with distinct fibrotic diseases involving the heart, lung, liver, or kidney. Unexpectedly, not all ACTA2-expressing cells were ECM-producing cells identified by expressing collagen genes; instead, the majority of ECM-producing cells were myofibroblasts and fibroblasts derived from circulating bone marrow precursor, and to a lesser extent from local pericytes and vascular smooth cells in all fibrotic diseases. This was confirmed in sex-mismatched kidney transplants by the discovery that ECM-producing cells originated from recipient, not donor, bone marrow-derived progenitor cells (BMPCs). Moreover, these BMPCs-derived ECM-producing cells exhibited a proinflammatory phenotype. Thus, bone marrow-derived proinflammatory and profibrotic fibroblasts/myofibroblasts with stem cell properties serve as a major source of ECM-producing cells and may play a driving role in tissue fibrosis across a wide range of human fibrotic diseases. Targeting these ECM-producing cells may provide a novel therapy for diseases with fibrosis.

Kidney disease represents a major medical and economic burden for which improved treatments are urgently needed. Emerging data have implicated Th17 cells and IL-17 signaling in the underlying pathogenesis of autoantibody-induced glomerulonephritis (AGN). However, the downstream transduction pathways mediated by IL-17 in autoimmunity are not well defined. In this article, we show that CCAAT/enhancer-binding protein (C/EBP) δ is elevated in kidney biopsies from multiple manifestations of human AGN. C/EBPδ is similarly upregulated in a mouse model of anti-glomerular basement membrane protein-mediated kidney disease, and Cebpd-/- mice were fully refractory to disease. Although C/EBPδ is expressed in a variety of cell types, C/EBPδ was required only in the radioresistant compartment to drive GN pathology. C/EBPδ induced expression of several IL-17-induced kidney injury markers and cytokines implicated in disease, including Il6 and Lcn2. Because mouse AGN models do not progress to fibrosis, we employed a nephrotoxic injury model using aristolochic acid I to assess the contribution of the IL-17-C/EBPδ pathway to renal fibrotic events. Surprisingly, deficiency of either C/EBPδ or the IL-17 receptor caused kidney fibrosis to be enhanced. Thus, C/EBPδ and IL-17 play divergent and apparently stage-specific roles in the pathogenesis of kidney disease.

Tissue fibrosis is a common pathway to failure in many organ systems and is the cellular and molecular driver of myriad chronic diseases that are incompletely understood and lack effective treatment. Recent studies suggest that gut microbe-dependent metabolites might be involved in the initiation and progression of fibrosis in multiple organ systems.

In a meta-organismal pathway that begins in the gut, gut microbiota convert dietary precursors such as choline, phosphatidylcholine, and L-carnitine into trimethylamine (TMA), which is absorbed and subsequently converted to trimethylamine N-oxide (TMAO) via the host enzyme flavin-containing monooxygenase 3 (FMO3) in the liver. Chronic exposure to elevated TMAO appears to be associated with vascular injury and enhanced fibrosis propensity in diverse conditions, including chronic kidney disease, heart failure, metabolic dysfunction-associated steatotic liver disease, and systemic sclerosis.

Despite the high prevalence of fibrosis, little is known to date about the role of gut dysbiosis and of microbe-dependent metabolites in its pathogenesis. This review summarizes recent important advances in the understanding of the complex metabolism and functional role of TMAO in pathologic fibrosis and highlights unanswered questions.