Transforming growth factor-β1 (TGF-β1)-stimulated fibroblast to myofibroblast differentiation is mediated by hyaluronan (HA)-facilitated epidermal growth factor receptor (EGFR) and CD44 co-localization in lipid rafts

A novel MMP-9 inhibitor exhibits selective inhibition in non-small-cell lung cancer harboring EGFR T790M mutation by blocking EGFR/STAT3 signaling pathway

The T790M secondary mutation in EGFR confers therapeutic resistance to EGFR-TKIs, leading to poor outcomes. Non-small-cell lung cancer (NSCLC) harboring EGFR T790M mutation is incurable and there is an urgent need for improved therapeutics. Here we report the identification of a small compound, MG-3C, that kills NSCLC cells with T790M mutation while sparing lung cancer cells without T790M mutation. We found that MG-3C activity targets EGFR-STAT3 signaling pathway in NSCLC through direct inhibition of matrix metalloproteinase 9 (MMP-9), ultimately leading to G2/M phase arrest, growth inhibition and apoptosis. Compared with the reported MMP-9 inhibitor Ilomastat, MG-3C shows high anticancer activity and affinity for targets. MG-3C forms hydrogen bonds with the ASP-113, ASP-201 and HIS-203 amino acid residues of MMP-9 with a docking fraction of -9.04 kcal/mol, while Ilomastat forms hydrogen bonds with the GLN-169, ASP-201 and HIS-203 amino acid residues of MMP-9 with a docking fraction of -5.98 kcal/mol. The spatial structure composed of ASP-113, ASP-201, and HIS-203 of MMP-9 provides a new coordinate for the design of MMP-9 inhibitors. Most importantly, subcutaneous and oral administration of MG-3C elicit dramatic regression of NSCLC xenograft tumors harboring T790M mutation as well as favorable biosafety profile in vivo, suggesting that MG-3C may be a potential candidate for NSCLC harboring T790M mutation.

Blocking cancer-fibroblast mutualism inhibits proliferation of endocrine therapy resistant breast cancer

In early-stage estrogen receptor-positive (ER + ) breast cancer, resistance to endocrine therapy (ET) and CDK4/6 inhibitors (CDK4/6i) often involve a shift away from estrogen-driven proliferation. The nature and source of compensatory growth signals driving cancer proliferation remain unknown but represent direct therapeutic targets of resistant cells. By analyzing single-cell RNA-sequencing data from serial biopsies of patient tumors, we elucidated compensatory growth signaling pathways activated in ET + CDK4/6i-resistant cancer cells, along with the intercellular growth signal communications within the tumor microenvironment. In most patient tumors, resistant cancer cells increased ERBB growth pathway activity during treatment, only partially through ERBB receptor upregulation. Concurrently, fibroblasts within the tumor increased ERBB ligand communication with cancer cells, as they differentiated to a proliferative and mesenchymal phenotype in response to TGF β signals from cancer cells. In vitro model systems demonstrated molecularly how therapy induces a mutualistic cycle of crosstalk between cancer cells and fibroblasts, fostering a growth factor-rich tumor microenvironment circumventing estrogen reliance. We show that ERBB inhibition can break this cancer-fibroblasts mutualism, targeting an acquired sensitivity of resistant cancer cells.

Effect of Fibroblast Signaling on Macrophage Polarization

Systemic and organ-specific fibrotic disorders are a leading cause of death worldwide. Crosstalk between fibroblasts and macrophages has been suggested as a key event leading to either resolution or aberrant remodeling and fibrosis. This study sought to identify the impacts of the timing and effects of exposure to quiescent (basal) and transforming growth factor-β-stimulated (activated) fibroblast secreted products on macrophage polarization and function. Naïve (M0 macrophages), lipopolysaccharide/interferon-γ-stimulated (M1 macrophages), and IL-4-stimulated (M2 macrophages) macrophages were exposed to basal or activated fibroblast conditioned media (FBCM) for 24 hours before, after, or during macrophage polarization. Macrophage function and polarization were quantified by phagocytosis, nitric oxide, and arginase activity assays and by cytokine array. FBCM from activated fibroblasts led to a pronounced up-regulation of arginase-1 compared with that from quiescent fibroblasts in M0 macrophages. Moreover, treatment with FBCM from activated fibroblasts resulted in significant increases in arginase-1 immunoexpression as well as urea production in M2 macrophages when applied antecedent, concurrent, or subsequent to M2 macrophage polarizing cytokines. Activated FBCM enhanced several proinflammatory cytokines, such as IL-1β and IL-6, in all macrophage subsets while only increasing tumor necrosis factor-α in M1 macrophages. This study elucidates multiple proinflammatory and profibrotic effects of fibroblasts on M1 and M2 macrophages, providing insights into the complex orchestration of macrophage-fibroblast crosstalk in fibrosis and the critical role of fibroblasts in the inflammatory response to injury.

Redox Mechanisms Driving Skin Fibroblast-to-Myofibroblast Differentiation

Transforming Growth Factor-Beta 1 (TGF-β1) plays a pivotal role in the differentiation of fibroblasts into myofibroblasts, which is a critical process in tissue repair, fibrosis, and wound healing. Upon exposure to TGF-β1, fibroblasts acquire a contractile phenotype and secrete collagen and extracellular matrix components. Numerous studies have identified hydrogen peroxide (H2O2) as a key downstream effector of TGF-β1 in this pathway. H2O2 functions as a signalling molecule, regulating various cellular processes mostly through post-translational redox modifications of cysteine thiol groups of specific proteins. In this study, we used primary human skin fibroblast cultures to investigate the oxidative mechanisms triggered by TGF-β1. We analyzed the expression of redox-related genes, evaluated the effects of the genetic and pharmacological inhibition of H2O2-producing enzymes, and employed an unbiased redox proteomics approach (OxICAT) to identify proteins undergoing reversible cysteine oxidation. Our findings revealed that TGF-β1 treatment upregulated the expression of oxidant-generating genes while downregulating antioxidant genes. Low concentrations of diphenyleneiodonium mitigated myofibroblast differentiation and mitochondrial oxygen consumption, suggesting the involvement of a flavoenzyme in this process. Furthermore, we identified the increased oxidation of highly conserved cysteine residues in key proteins such as the epidermal growth factor receptor, filamin A, fibulin-2, and endosialin during the differentiation process. Collectively, this study provides insights into the sources of H2O2 in fibroblasts and highlights the novel redox mechanisms underpinning fibroblast-to-myofibroblast differentiation.

Adoptive Transfer of T Cells as a Potential Therapeutic Approach in the Bleomycin-Injured Mouse Lung

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a lethal disease with an unknown etiology and complex pathophysiology that are not fully understood. The disease involves intricate cellular interplay, particularly among various immune cells. Currently, there is no treatment capable of reversing the fibrotic process or aiding lung regeneration. Hepatocyte growth factor (HGF) has demonstrated antifibrotic properties, whereas the adoptive transfer of modified T cells is a well-established treatment for various malignancies. We aimed to understand the dynamics of T cells in the progression of lung fibrosis and to study the therapeutic benefit of adoptive T cell transfer in a bleomycin-injured mouse lung (BLM) model.

METHODS

T cells were isolated from the spleen of naïve mice and transfected in vitro with mouse HGF plasmid and were administered intratracheally to the mice lungs 7 days post-bleomycin injury to the lung. Lung tissue and bronchoalveolar lavage were collected and analyzed using flow cytometry, histology, qRT-PCR, ELISA, and hydroxyproline assay.

RESULTS

Our findings demonstrate the successful T cell therapy of bleomycin-induced lung injury through the adoptive transfer of HGF-transfected T cells in mice. This treatment resulted in decreased collagen deposition and a balancing of immune cell exhaustion and cytokine homeostasis compared with untreated controls. In vitro testing showed enhanced apoptosis in myofibroblasts induced by HGF-overexpressing T cells.

CONCLUSIONS

Taken together, our data highlight the great potential of adoptive T cell transfer as an emerging therapy to counteract lung fibrosis.

Engineered Intelligent Microenvironment Responsive Prodrug Conjugates Navigated by Bioinspired Lipoproteins for Reversing Liver Fibrosis

Liver fibrosis (LF) is characterized by excessive production of reactive oxygen species (ROS), abnormal activation of hepatic stellate cells (HSCs), and subsequent extracellular matrix (ECM) deposition. The complexity of multiple interrelated pathways involved in this process makes it challenging for monotherapy to achieve the desired therapeutic effects. To address this issue, this study designs a ROS-activated heterodimer conjugate (VTO) to collaboratively alleviate LF. Additionally, a biomimetic high-density lipoprotein is utilized for encapsulation, resulting in the formation of PL-VTO, which enables natural liver targeting. Once PL-VTO is delivered to the fibrotic liver, it can respond and release both parent drugs upon encountering the high ROS microenvironment, effectively scavenge ROS, induce quiescence of activated HSCs, and reduce collagen deposition, ultimately reversing LF. Overall, this study presents a feasible and versatile nanotherapeutic approach to enhance the prodrug-driven treatment of LF.

MRI radiomics based on machine learning in high-grade gliomas as a promising tool for prediction of CD44 expression and overall survival

We aimed to predict CD44 expression and assess its prognostic significance in patients with high-grade gliomas (HGG) using non-invasive radiomics models based on machine learning. Enhanced magnetic resonance imaging, along with the corresponding gene expression and clinicopathological data, was downloaded from online database. Kaplan-Meier survival curves, univariate and multivariate COX analyses, and time-dependent receiver operating characteristic were used to assess the prognostic value of CD44. Following the screening of radiomic features using repeat least absolute shrinkage and selection operator, two radiomics models were constructed utilizing logistic regression and support vector machine for validation purposes. The results indicated that CD44 protein levels were higher in HGG compared to normal brain tissues, and CD44 expression emerged as an independent biomarker of diminished overall survival (OS) in patients with HGG. Moreover, two predictive models based on seven radiomic features were built to predict CD44 expression levels in HGG, achieving areas under the curves (AUC) of 0.809 and 0.806, respectively. Calibration and decision curve analysis validated the fitness of the models. Notably, patients with high radiomic scores presented worse OS (p < 0.001). In summary, our results indicated that the radiomics models effectively differentiate CD44 expression level and OS in patients with HGG.

Variations in ECM Topography, Fiber Alignment, Mechanical Stiffness, and Cellular Composition Between Ventral and Dorsal Ligamentum Flavum Layers: Insights Into Hypertrophy Pathogenesis

Background

Previous studies have suggested that changes in the composition of the extracellular matrix (ECM) play a significant role in the development of ligamentum flavum hypertrophy (LFH) and the histological differences between the ventral and dorsal layers of the hypertrophied ligamentum flavum. Although LFH is associated with increased fibrosis in the dorsal layer, comprehensive research exploring the characteristics of the ECM and its mechanical properties in both regions is limited. Furthermore, the distribution of fibrosis-associated myofibroblasts within LFH remains poorly understood. This study aimed to bridge the existing knowledge gap concerning the intricate relationships between ECM characteristics, mechanical properties, and myofibroblast expression in LFH.

Methods

Histological staining, scanning electron microscopy, and atomic force microscopy were used to analyze the components, alignment, and mechanical properties of the ECM. Immunostaining and western blot analyses were performed to assess the distribution of myofibroblasts in LF tissues.

Results

There were notable differences between the dorsal and ventral layers of the hypertrophic ligamentum flavum. Specifically, the dorsal layer exhibited higher collagen content and disorganized fibrous alignment, resulting in reduced stiffness. Immunohistochemistry analysis revealed a significantly greater presence of α-smooth muscle actin (αSMA)-stained cells, a marker for myofibroblasts, in the dorsal layer.

Conclusions

This study offers comprehensive insights into LFH by elucidating the distinctive ECM characteristics, mechanical properties, and cellular composition disparities between the ventral and dorsal layers. These findings significantly enhance our understanding of the pathogenesis of LFH and may inform future research and therapeutic strategies.

Visualization of the Relationship Between Hyaluronic Acid and Wound Healing: A Bibliometric Analysis

BACKGROUND

Wound healing is a complex process with significant economic implications. Hyaluronic acid (HA), valued for its adaptability and biocompatibility, shows the potential to improve multiple facets of wound healing. Despite the expanding literature on the use of HA in wound care, a comprehensive analysis of its scholarly evolution is lacking. This study employs a bibliometric approach to objectively evaluate trends in scholarly publications regarding HA's role in promoting wound healing.

METHODS

We searched in the Web of Science Core Collection (WoSCC) for articles published from January 1, 2000 to March 31, 2024. We extracted relevant information about using HA to promote wound healing following a thorough screening process. Subsequently, a comprehensive analysis was undertaken on a total of 1886 publications. The analysis utilized GraphPad Prism 9, CiteSpace6.1.6, VOSviewer1.6.19, the Online Analysis Platform of Literature Metrology (http://bibliometric.com/), GeneMANIA (https://genemania.org/), and Metascape (https://metascape.org/gp/index.html#/main/step1).

RESULTS

We retrieved 2424 publications on hyaluronic acid (HA) and wound healing from the Web of Science Core Collection, covering the period from January 2000 to March 2024, and selected 1886 for analysis. The results show a significant increase in publications since 2016, reflecting a growing focus on this field. Currently, China's publication volume has surpassed the United States since 2017, indicating a significant rise in China's influence in this area. Using CiteSpace software for co-citation analysis, we identified eight main research clusters, including promoted wound healing, injured tissue, and advanced multi-targeted composite biomaterial. Key research areas involve the role and mechanisms of hyaluronic acid in tissue repair, particularly its applications in growth factor production and regenerative therapy. Analyzing keyword co-occurrence and burst data with VOSviewer, we identified research hotspots focused on biomaterials, such as nanoparticles and hydrogels, and their antibacterial properties. The keyword "CD44" showed a long burst period, while "antibacterial" had the highest burst intensity in 2022. We identified the top 21 genes extensively studied in hyaluronic acid and wound healing, including CD44, VEGF, and TGF-β. These genes are mainly involved in regulating cell migration, adhesion, proliferation, and cytokine activity. GO enrichment and KEGG pathway analyses indicate that these genes are associated with key signaling pathways, such as MAPK and EGFR, revealing the primary mechanisms hyaluronic acid promotes wound healing.

CONCLUSION

This pioneering study provides the first comprehensive bibliometric analysis of HA in wound healing. Covering the period from January 1, 2000 to March 31, 2024, it reveals a significant expansion in annual scholarly production. Current research emphasizes the development of HA-based biomaterials for enhancing wound healing.

Myofibroblasts reduce angiogenesis and vasculogenesis in a vascularized microphysiological model of lung fibrosis

Lung fibrosis, characterized by chronic and progressive scarring, has no cure. Hallmarks are the accumulation of myofibroblasts and extracellular matrix, as well as vascular remodeling. The crosstalk between myofibroblasts and vasculature is poorly understood, with conflicting reports on whether angiogenesis and vessel density are increased or decreased in lung fibrosis. We developed a microphysiological system that recapitulates the pathophysiology of lung fibrosis and disentangles myofibroblast-vascular interactions. Lung myofibroblasts maintained their phenotype in 3D without exogenous TGF-β and displayed anti-angiogenic and anti-vasculogenic activities when cultured with endothelial cells in a microfluidic device. These effects, including decreased endothelial sprouting, altered vascular morphology, and increased vascular permeability, were mediated by increased TGF-β1 and reduced VEGF secretion. Pharmacological interventions targeting these cytokines restored vascular morphology and permeability, demonstrating the potential of this model to screen anti-fibrotic drugs. This system provides insights into myofibroblast-vascular crosstalk in lung fibrosis and offers a platform for therapeutic development.

Enhancing cell activities through integration of polyanionic alginate or hyaluronic acid derivatives with triboelectric nanogenerators

The impact of electrical stimulation has been widely investigated on the wound healing process; however, its practicality is still challenging. This study explores the effect of electrical stimulation on fibroblasts in a culture medium containing different electrically-charged polysaccharide derivatives including alginate, hyaluronate, and chitosan derivatives. For this aim, an electrical stimulation, provided by a zigzag triboelectric nanogenerator (TENG), was exerted on fibroblasts in the presence of polysaccharides' solutions. The analyses showed a significant increase in cell proliferation and an improvement in wound closure (160 % and 90 %, respectively) for the hyaluronate-containing medium by a potential of 3 V after 48 h. In the next step, a photo-crosslinkable hydrogel was prepared based on hyaluronic acid methacrylate (HAMA). Then, the cells were cultured on HAMA hydrogel and treated by an electrical stimulation. Surprisingly, the results showed a remarkable increase in cell growth (280 %) and migration (82 %) after 24 h. Attributed to the electroosmosis phenomenon and an amplified transfer of soluble growth factors, a dramatic promotion was underscored in cell activities. These findings highlight the role of electroosmosis in wound healing, where TENG-based electrical stimulation is combined with bioactive polysaccharide-based hydrogels to promote wound healing.

CTHRC1 Attenuates Tendinopathy via Enhancing EGFR/MAPK Signaling Pathway

Tendinopathy poses a formidable challenge due to the inherent limitations of tendon regenerative capabilities post-injury. At present, effective curative approaches for tendinopathy are still lacking. Collagen triple helix repeat-containing 1 (CTHRC1) is an extracellular matrix protein with significant roles in both physiological and pathological processes. The present study aims to investigate the function and underlying mechanism of CTHRC1 in tendinopathy. In this study, CTHRC1 is identified as a potential effector in promoting tendon regeneration through multi-proteomic analysis of Achilles tendon tissues in mice. In vitro, CTHRC1 enhances the proliferation, migration, and tenogenic differentiation of tendon stem/progenitor cell (TSPC). In vivo, CTHRC1 deletion impairs tendon healing, while its overexpression reverses the detrimental effects caused by CTHRC1 deficiency. Mechanistically, proteomics on TSPC stimulated with recombinant CTHRC1 reveal that CTHRC1 activates the mitogen-activated protein kinase (MAPK) signaling pathway via binding to epidermal growth factor receptor (EGFR), which in turn promotes the proliferative, migrative, and tenogenic capacities of TSPC to attenuate Achilles tendinopathy. Conversely, inhibiting EGFR reverses the tendon-healing effect of CRHRC1. The study demonstrates that CTHRC1 can promote the proliferative, migrative, and tenogenic capacities of TSPC, ultimately facilitating tendon healing through activating the EGFR/MAPK signaling pathway. CTHRC1 holds promise as a potential intervention for tendinopathy.

Efficacy of a Novel Melatonin-Loaded Gelatin Sponge in Palatal Wound Healing

OBJECTIVES

The aim of this research was to assess both clinically and histologically the effect of a topically applied melatonin-loaded gelatin sponge on palatal wound healing after graft harvesting.

METHODS

Twenty-six patients for whom free palatal graft procurement was indicated were divided equally into 2 groups. In the test group, the donor site was covered by a melatonin-loaded gelatin sponge, and in the control group the site was covered by a placebo-loaded gelatin sponge. Wound healing was evaluated on the day of surgery and at 7 and 14 days postsurgery using photo-digital planimetry. Histologic specimens were taken to verify healing type and rate. Pain was assessed via Visual Analogue Scale (VAS) for 7 days from the day of the surgery.

RESULTS

At the 7-day interval, photo-digital planimetry showed a significant decrease in the traced raw area (P = .04) in the test group compared with the control group and a significant increase in the mean area of immature epithelia (P = .04). At the 14-day interval, there was no statistically significant difference in any area of interest. Histologically, the application of melatonin was associated with accelerated healing and superior maturation at all follow-up time points. No significant differences were noted in VAS scores between the 2 groups.

CONCLUSIONS

Melatonin-treated tissue showed marked clinical improvement in the first week postsurgery, indicating an increased rate of healing. Similarly, histologic analysis revealed significant maturation at both time intervals. A melatonin-loaded gelatin sponge is a novel palatal wound dressing that can be used to improve wound healing outcomes and reduce patient morbidity.

Telocytes of the male reproductive system: dynamic tissue organizers

Telocytes are CD34+ interstitial cells that have long cytoplasmic projections (called telopodes), and have been detected in several organs, including those of the male reproductive system. In this brief review we evaluate the role of telocytes in tissue organization of the different organs of the male reproductive system in which these cells were studied. In general terms, telocytes act in the tissue organization through networks of telopodes that separate the epithelia from the stroma, as well as dividing the stroma into different compartments. In addition to this contribution to the structural integrity, there is direct and indirect evidence that such "walls" formed by telocytes also compartmentalize paracrine factors that they or other cells produce, which have a direct impact on morphogenesis and the maintenance of organ cell differentiation, as well as on their normal physiology. Moreover, alterations in telocytes and telopode networks are correlated with pathological conditions in the male reproductive system, in response to profound changes in structural organization of the organs, in inflammation, hyperplasia and cancer. Further studies are necessary to evaluate the molecular pathways telocytes employ in different contexts of physiology and disease.

Microparticles Decorated with Cell-Instructive Surface Chemistries Actively Promote Wound Healing

Wound healing is a complex biological process involving close crosstalk between various cell types. Dysregulation in any of these processes, such as in diabetic wounds, results in chronic nonhealing wounds. Fibroblasts are a critical cell type involved in the formation of granulation tissue, essential for effective wound healing. 315 different polymer surfaces are screened to identify candidates which actively drive fibroblasts toward either pro- or antiproliferative functional phenotypes. Fibroblast-instructive chemistries are identified, which are synthesized into surfactants to fabricate easy to administer microparticles for direct application to diabetic wounds. The pro-proliferative microfluidic derived particles are able to successfully promote neovascularization, granulation tissue formation, and wound closure after a single application to the wound bed. These active novel bio-instructive microparticles show great potential as a route to reducing the burden of chronic wounds.

A bioactive xyloglucan polysaccharide hydrogel mechanically enhanced by Pluronic F127 micelles for promoting chronic wound healing

Chronic wounds represent a formidable global healthcare challenge due to the bacteria infections and uncontrollable inflammation responses, while developing wound healing materials capable of resolving these issues remains a challenge. In this study, we integrated xyloglucan (XG) with Pluronic F127 diacrylate (F127DA)to develop a composite hydrogel for wound healing, where the XG introduced anti-inflammation and anti-bacterial properties to the construct, and F127DA provides the photocurable properties essential for hydrogel formation and robust mechanical characteristics to achieve physical strength that matches tissue regeneration. The material characterizations suggested that XG/F127DA hydrogels had great biostability, blood compatibility and antibacterial effects, which was suitable to be used as a wound healing material. The in vitro analysis by culturing L929 fibroblasts on the hydrogel surface demonstrated that the inclusion of XG could promote the cellular proliferation rate, migration rate, and re-epithelialization-related marker expression, while downregulate the inflammation process. The XG/F127DA hydrogel was further used for the full-thickness skin wound healing test on mice, where the inclusion of XG significantly increased the wound closure rate through reducing the inflammation responses, and promote re-epithelialization and angiogenesis. These results indicated that XG/F127DA hydrogel has great potential to be used for wound healing in future clinical translation.

Effect of Placental Derived Nucleoproteins on liver regeneration in DEN-induced liver fibrosis model

BACKGROUND

Placental Derived Nucleoproteins (PDNs) is commonly associated with the process of angiogenesis, and doesn't affect the healthy vasculature. PDNs are clinically estimated for the treatment of cancer cases and severe hepatic injuries. Thus, the pathophysiological effects of PDNs targeting liver fibrosis is a concern.

OBJECTIVES

To assess the molecular, histopathological, and chemical impact of PDNs on liver regeneration in Diethylnitrosamine (DEN)-induced mice liver fibrosis.

METHODS

Normal untreated reference group of ten mice and two groups of induced liver cirrhosis using the recommended weekly dose of Diethylnitrosamine in total of eleven doses, initially 20 mg/kg body weight, and then 30 mg/kg in the third week, followed by 50 mg/kg for the last eight weeks, one of them combined treatment aligned with injection with total dose of extracted PDNs 25 mg/kg, in comparison to PDNs only treated group. An autopsy was performed after 22 weeks of the initial dose of DEN in each group. Molecular characterization of Alpha smooth muscle actin, TGFβ and NF-κB biomarkers for liver then liver function panel were analyzed and finally hepatopathological changes were observed using H&E stain and Sirius red stain.

RESULTS

Liver enzymes, total bilirubin and total proteins in tissue in PDNs-DEN treated models were controlled in the direction of normal group and 50 % reduction of fibrosis in comparing to DEN-treated models. The cellular arrangement of fibrosis in the DEN entire groups were differentiated with high significant impact on the survival of mice. Increased levels of the biochemical markers in liver homogenate, loss of tissue architecture, and proliferation were observed in induced groups and down regulation of alpha smooth muscle actin, TGFβ and NF-κB.

CONCLUSION

This finding demonstrates an improvement of Liver tissue induced fibrosis using DEN combined with PDNs. This strategy is to generate an animal model with a lower occurrence of fibrosis in a short time treatment regarding liver regeneration.

Expression of TGFβ-1 and CTGF in the Implanted Cochlea and its Implication on New Tissue Formation

HYPOTHESIS

Transforming growth factor beta-1 (TGFβ-1) and connective tissue growth factor (CTGF) are upregulated in the implanted human cochlea.

BACKGROUND

Cochlear implantation can lead to insertion trauma and intracochlear new tissue formation, which can detrimentally affect implant performance. TGFβ-1 and CTGF are profibrotic proteins implicated in various pathologic conditions, but little is known about their role in the cochlea. The present study aimed to characterize the expression of these proteins in the human implanted cochlea.

METHODS

Archival human temporal bones (HTB) acquired from 12 patients with previous CI and histopathological evidence of new tissue formation as well as surgical samples of human intracochlear scar tissue surrounding the explanted CI were used in this study. Histopathologic analysis of fibrosis and osteoneogenesis was conducted using H&E. Protein expression was characterized using immunofluorescence. RNA expression from surgical specimens of fibrotic tissue surrounding the CI was quantified using qRT-PCR.

RESULTS

TGFβ-1 and CTGF protein expressions were upregulated in the areas of fibrosis and osteoneogenesis surrounding the CI HTB. Similarly, surgical samples demonstrated upregulation of protein and mRNA expression of TGFβ-1 and mild upregulation of CTGF compared with control. TGFβ-1 was expressed diffusely within the fibrous capsule, whereas CTGF was expressed in the thickened portion toward the modiolus and the fibrosis-osteoneogensis junction.

CONCLUSION

To our knowledge, this is the first study to demonstrate increased expression of TGFβ-1 and CTGF in the human implanted cochlea and may provide better understanding of the mechanism behind this pathogenic process to better develop future mitigating interventions.

Adult cardiomyocytes-derived EVs for the treatment of cardiac fibrosis

Cardiac fibrosis is a common pathological feature of cardiovascular diseases that arises from the hyperactivation of fibroblasts and excessive extracellular matrix (ECM) deposition, leading to impaired cardiac function and potentially heart failure or arrhythmia. Extracellular vesicles (EVs) released by cardiomyocytes (CMs) regulate various physiological functions essential for myocardial homeostasis, which are disrupted in cardiac disease. Therefore, healthy CM-derived EVs represent a promising cell-free therapy for the treatment of cardiac fibrosis. To this end, we optimized the culture conditions of human adult CMs to obtain a large yield of EVs without compromising cellular integrity by using a defined combination of small molecules. EVs were isolated by ultracentrifugation, and their characteristics were analysed. Finally, their effect on fibrosis was tested. Treatment of TGFβ-activated human cardiac fibroblasts with EVs derived from CMs using our culture system resulted in a decrease in fibroblast activation markers and ECM accumulation. The rescued phenotype was associated with specific EV cargo, including multiple myocyte-specific and antifibrotic microRNAs, although their effect individually was not as effective as the EV treatment. Notably, pathway analysis showed that EV treatment reverted the transcription of activated fibroblasts and decreased several signalling pathways, including MAPK, mTOR, JAK/STAT, TGFβ, and PI3K/Akt, all of which are involved in fibrosis development. Intracardiac injection of CM-derived EVs in an animal model of cardiac fibrosis reduced fibrotic area and increased angiogenesis, which correlated with improved cardiac function. These findings suggest that EVs derived from human adult CMs may offer a targeted and effective treatment for cardiac fibrosis, owing to their antifibrotic properties and the specificity of cargo.

Application of single-molecule analysis to singularity phenomenon of cells

Single-molecule imaging in living cells is an effective tool for elucidating the mechanisms of cellular phenomena at the molecular level. However, the analysis was not designed for throughput and requires high expertise, preventing it from reaching large scale, which is necessary when searching for rare cells that induce singularity phenomena. To overcome this limitation, we have automated the imaging procedures by combining our own focusing device, artificial intelligence, and robotics. The apparatus, called automated in-cell single-molecule imaging system (AiSIS), achieves a throughput that is a hundred-fold higher than conventional manual imaging operations, enabling the analysis of molecular events by individual cells across a large population. Here, using AiSIS, we demonstrate the single-molecule imaging of molecular behaviors and reactions related to tau protein aggregation, which is considered a singularity phenomenon in neurological disorders. Changes in the dynamics and kinetics of molecular events were observed inside and on the basal membrane of cells after the induction of aggregation. Additionally, to detect rare cells based on the molecular behavior, we developed a method to identify the state of individual cells defined by the quantitative distribution of molecular mobility and clustering. Using this method, cellular variations in receptor behavior were shown to decrease following ligand stimulation. This cell state analysis based on large-scale single-molecule imaging by AiSIS will advance the study of molecular mechanisms causing singularity phenomena.

Osteosarcoma cell death induced by innovative scaffolds doped with chemotherapeutics

Osteosarcoma (OS) cancer treatments include systemic chemotherapy and surgical resection. In the last years, novel treatment approaches have been proposed, which employ a drug-delivery system to prevent offside effects and improves treatment efficacy. Locally delivering anticancer compounds improves on high local concentrations with more efficient tumour-killing effect, reduced drugs resistance and confined systemic effects. Here, the synthesis of injectable strontium-doped calcium phosphate (SrCPC) scaffold was proposed as drug delivery system to combine bone tissue regeneration and anticancer treatment by controlled release of methotrexate (MTX) and doxorubicin (DOX), coded as SrCPC-MTX and SrCPC-DOX, respectively. The drug-loaded cements were tested in an in vitro model of human OS cell line SAOS-2, engineered OS cell line (SAOS-2-eGFP) and U2-OS. The ability of doped scaffolds to induce OS cell death and apoptosis was assessed analysing cell proliferation and Caspase-3/7 activities, respectively. To determine if OS cells grown on doped-scaffolds change their migratory ability and invasiveness, a wound-healing assay was performed. In addition, the osteogenic potential of SrCPC material was evaluated using human adipose derived-mesenchymal stem cells. Osteogenic markers such as (i) the mineral matrix deposition was analysed by alizarin red staining; (ii) the osteocalcin (OCN) protein expression was investigated by enzyme-linked immunosorbent assay test, and (iii) the osteogenic process was studied by real-time polymerase chain reaction array. The delivery system induced cell-killing cytotoxic effects and apoptosis in OS cell lines up to Day 7. SrCPC demonstrates a good cytocompatibility and it induced upregulation of osteogenic genes involved in the skeletal development pathway, together with OCN protein expression and mineral matrix deposition. The proposed approach, based on the local, sustained release of anticancer drugs from nanostructured biomimetic drug-loaded cements is promising for future therapies aiming to combine bone regeneration and anticancer local therapy.

Glycan Modifications as Regulators of Stem Cell Fate

Glycosylation is a process where proteins or lipids are modified with glycans. The presence of glycans determines the structure, stability, and localization of glycoproteins, thereby impacting various biological processes, including embryogenesis, intercellular communication, and disease progression. Glycans can influence stem cell behavior by modulating signaling molecules that govern the critical aspects of self-renewal and differentiation. Furthermore, being located at the cell surface, glycans are utilized as markers for stem cell pluripotency and differentiation state determination. This review aims to provide a comprehensive overview of the current literature, focusing on the effect of glycans on stem cells with a reflection on the application of synthetic glycans in directing stem cell differentiation. Additionally, this review will serve as a primer for researchers seeking a deeper understanding of how synthetic glycans can be used to control stem cell differentiation, which may help establish new approaches to guide stem cell differentiation into specific lineages. Ultimately, this knowledge can facilitate the identification of efficient strategies for advancing stem cell-based therapeutic interventions.

Inflammatory Markers Involved in the Pathogenesis of Dupuytren's Contracture

Dupuytren's disease is a common fibroproliferative disease that can result in debilitating hand deformities. Partial correction and return of deformity are common with surgical or clinical treatments at present. While current treatments are limited to local procedures for relatively late effects of the disease, the pathophysiology of this connective tissue disorder is associated with both local and systemic processes (e.g., fibrosis, inflammation). Hence, a better understanding of the systemic circulation of Dupuytren related cytokines and growth factors may provide important insights into disease progression. In addition, systemic biomarker analysis could yield new concepts for treatments of Dupuytren that attenuate circulatory factors (e.g., anti-inflammatory agents, neutralizing antibodies). Progress in the development of any disease modifying biologic treatment for Dupuytren has been hampered by the lack of clinically useful biomarkers. The characterization of nonsurgical Dupuytren biomarkers will permit disease staging from diagnostic and prognostic perspectives, as well as allows evaluation of biologic responses to treatment. Identification of such markers may transcend their use in Dupuytren treatment, because fibrotic biological processes fundamental to Dupuytren are relevant to fibrosis in many other connective tissues and organs with collagen-based tissue compartments. There is a wide range of potential Dupuytren biomarker categories that could be informative, including disease determinants linked to genetics, collagen metabolism, as well as immunity and inflammation (e.g., cytokines, chemokines). This narrative review provides a broad overview of previous studies and emphasizes the importance of inflammatory mediators as candidate circulating biomarkers for monitoring Dupuytren's disease.

Antifibrotic properties of hyaluronic acid crosslinked polyisocyanide hydrogels

Fibrosis is characterized by the formation of fibrous connective tissue in response to primary injury. As a result, an affected organ may lose part of its functionality due to chronic, organ-specific tissue damage. Since fibrosis is a leading cause of death worldwide, targeting fibrotic diseases with antifibrotic hydrogels can be a lifesaving therapeutic strategy. This study developed a novel hybrid antifibrotic hydrogel by combining the synthetic polyisocyanide (PIC) with hyaluronic acid (HA). Gels of PIC are highly tailorable, thermosensitive, and strongly biomimetic in architecture and mechanical properties, whereas HA is known to promote non-fibrotic fetal wound healing and inhibits inflammatory signaling. The developed HA-PIC hybrids were biocompatible with physical properties comparable to those of the PIC gels. The antifibrotic nature of the gels was assessed by 3D cultures of human foreskin fibroblasts in the presence (or absence as control) of TGFβ1 that promotes differentiation into myofibroblasts, a critical step in fibrosis. Proliferation and macroscopic contraction assays and studies on the formation of stress fibers and characteristic fibrosis markers all indicate a strong antifibrotic nature of HA-PIC hydrogel. We showed that these effects originate from both the lightly crosslinked architecture and the presence of HA itself. The hybrid displaying both these effects shows the strongest antifibrotic nature and is a promising candidate for use as in vivo treatment for skin fibrosis.

Alginate/gum arabic-based biomimetic hydrogel enriched with immobilized nerve growth factor and carnosine improves diabetic wound regeneration

Diabetic foot ulcers (DFUs) often remain untreated because they are difficult to heal, caused by reduced skin sensitivity and impaired blood vessel formation. In this study, we propose a novel approach to manage DFUs using a multifunctional hydrogel made from a combination of alginate and gum arabic. To enhance the healing properties of the hydrogel, we immobilized nerve growth factor (NGF), within specially designed mesoporous silica nanoparticles (MSN). The MSNs were then incorporated into the hydrogel along with carnosine (Car), which further improves the hydrogel's therapeutic properties. The hydrogel containing the immobilized NGF (SiNGF) could control the sustain release of NGF for >21 days, indicating that the target hydrogel (AG-Car/SiNGF) can serve as a suitable reservoir managing diabetic wound regeneration. In addition, Car was able to effectively reduce inflammation and significantly increase angiogenesis compared to the control group. Based on the histological results obtained from diabetic rats, the target hydrogel (AG-Car/SiNGF) reduced inflammation and improved re-epithelialization, angiogenesis, and collagen deposition. Specific staining also confirmed that AG-Car/SiNGF exhibited improved tissue neovascularization, transforming growth factor-beta (TGFβ) expression, and nerve neurofilament. Overall, our research suggests that this newly developed composite system holds promise as a potential treatment for non-healing diabetic wounds.

Elevated Serum Gastrin Is Associated with Melanoma Progression: Putative Role in Increased Migration and Invasion of Melanoma Cells

Micro-environmental factors, including stromal and immune cells, cytokines, and circulating hormones are well recognized to determine cancer progression. Melanoma cell growth was recently shown to be suppressed by cholecystokinin/gastrin (CCK) receptor antagonists, and our preliminary data suggested that melanoma patients with Helicobacter gastritis (which is associated with elevated serum gastrin) might have an increased risk of cancer progression. Therefore, in the present study, we examined how gastrin may act on melanoma cells. In 89 melanoma patients, we found a statistically significant association between circulating gastrin concentrations and melanoma thickness and metastasis, which are known risk factors of melanoma progression and prognosis. Immunocytochemistry using a validated antibody confirmed weak to moderate CCK2R expression in both primary malignant melanoma cells and the melanoma cell lines SK-MEL-2 and G361. Furthermore, among the 219 tumors in the Skin Cutaneous Melanoma TCGA Pan-Cancer dataset showing gastrin receptor (CCKBR) expression, significantly higher CCKBR mRNA levels were linked to stage III-IV than stage I-II melanomas. In both cell lines, gastrin increased intracellular calcium levels and stimulated cell migration and invasion through mechanisms inhibited by a CCK2 receptor antagonist. Proteomic studies identified increased MMP-2 and reduced TIMP-3 levels in response to gastrin that were likely to contribute to the increased migration of both cell lines. However, the effects of gastrin on tumor cell invasion were relatively weak in the presence of the extracellular matrix. Nevertheless, dermal fibroblasts/myofibroblasts, known also to express CCK2R, increased gastrin-induced cancer cell invasion. Our data suggest that in a subset of melanoma patients, an elevated serum gastrin concentration is a risk factor for melanoma tumor progression, and that gastrin may act on both melanoma and adjacent stromal cells through CCK2 receptors to promote mechanisms of tumor migration and invasion.

Platelet Rich Plasma Loaded Multifunctional Hydrogel Accelerates Diabetic Wound Healing via Regulating the Continuously Abnormal Microenvironments

Continuous oxidative stress and cellular dysfunction caused by hyperglycemia are distinguishing features of diabetic wounds. It has been a great challenge to develop a smart dressing that can accelerate diabetic wound healing through regulating abnormal microenvironments. In this study, a platelet rich plasma (PRP) loaded multifunctional hydrogel with reactive oxygen species (ROS) and glucose dual-responsive property is reported. It can be conveniently prepared with PRP, dopamine (DA) grafted alginate (Alg-DA), and 6-aminobenzo[c][1,2]oxaborol-1(3H)-ol (ABO) conjugated hyaluronic acid (HA-ABO) through ionic crosslinks, hydrogen-bond interactions, and boronate ester bonds. The hydrogel possesses injectability, moldability, tissue adhesion, self-healing, low hemolysis, and hemostasis performances. Its excellent antioxidant property can create a low oxidative stress microenvironment for other biological events. Under an oxidative stress and/or hyperglycemia state, the hydrogel can degrade at an accelerated rate to release a variety of cytokines derived from activated blood platelets. The result is a series of positive changes that are favorable for diabetic wound healing, including fast anti-inflammation, activated macrophage polarization toward M2 phenotype, promoted migration and proliferation of fibroblasts, as well as expedited angiogenesis. This work provides an efficient strategy for chronic diabetic wound management and offers an alternative for developing a new-type PRP-based bioactive wound dressing.

Signatures of necroptosis-related genes as diagnostic markers of endometriosis and their correlation with immune infiltration

BACKGROUND

Endometriosis (EMS) occurs when normal uterine tissue grows outside the uterus and causes chronic pelvic pain and infertility. Endometriosis-associated infertility is thought to be caused by unknown mechanisms. In this study, using necroptosis-related genes, we developed and validated multigene joint signatures to diagnose EMS and explored their biological roles.

METHODS

We downloaded two databases (GSE7305 and GSE1169) from the Gene Expression Omnibus (GEO) database and 630 necroptosis-related genes from the GeneCards and GSEA databases. The limma package in Rsoftware was used to identify differentially expressed genes (DEGs). We interleaved common differentially expressed genes (co-DEGs) and necroptosis-related genes (NRDEGs) in the endometriosis dataset. The DEGs functions were reflected by gene ontology analysis (GO), pathway enrichment analysis, and gene set enrichment analysis (GSEA). We used CIBERSORT to analyze the immune microenvironment differences between EMS patients and controls. Furthermore, a correlation was found between necroptosis-related differentially expressed genes and infiltrating immune cells to better understand the molecular immune mechanism.

RESULTS

Compared with the control group, this study revealed that 10 NRDEGs were identified in EMS. There were two types of immune cell infiltration abundance (activated NK cells and M2 macrophages) in these two datasets, and the correlation between different groups of samples was statistically significant (P < 0.05). MYO6 consistently correlated with activated NK cells in the two datasets. HOOK1 consistently demonstrated a high correlation with M2 Macrophages in two datasets. The immunohistochemical result indicated that the protein levels of MYO6 and HOOK1 were increased in patients with endometriosis, further suggesting that MYO6 and HOOK1 can be used as potential biomarkers for endometriosis.

CONCLUSIONS

We identified ten necroptosis-related genes in EMS and assessed their relationship with the immune microenvironment. MYO6 and HOOK1 may serve as novel biomarkers and treatment targets in the future.

Prostaglandin E2 attenuates lung fibroblast differentiation via inactivation of yes-associated protein signaling

Prostaglandin E2 (PGE2 ) has been implicated in counteracting fibroblast differentiation by TGFβ1 during pulmonary fibrosis. However, the precise mechanism is not well understood. We show here that PGE2 via EP2 R and EP4 R inhibits the expression of mechanosensory molecules Lysyl Oxidase Like 2 (LOXL2), myocardin-related transcription factor A (MRTF-A), ECM proteins, plasminogen activation inhibitor 1 (PAI-1), fibronectin (FN), α-smooth muscle actin (α-SMA), and redox sensor (nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 4 (NOX4)) required for TGFβ1-mediated fibroblast differentiation. We further demonstrate that PGE2 inhibits fibrotic signaling via Yes-associated protein (YAP) but does so independently from its actions on SMAD phosphorylation and conserved cylindromatosis (CYLD; deubiquitinase) expression. Mechanistically, PGE2 phosphorylates/inactivates YAP downstream of EP2 R/Gαs and restrains its translocation to the nucleus, thus inhibiting its interaction with TEA domain family members (TEADs) and transcription of fibrotic genes. Importantly, pharmacological or siRNA-mediated inhibition of YAP significantly downregulates TGFβ1-mediated fibrotic gene expression and myofibroblast formation. Notably, YAP expression is upregulated in the lungs of D. farinae-treated wild type (WT) mice relative to saline-treated WT mice. Our results unravel a unique role for PGE2 -YAP interactions in fibroblast differentiation, and that PGE2 /YAP inhibition can be used as a novel therapeutic target in the treatment of pathological conditions associated with myofibroblasts like asthma.

Pansclerotic morphea is characterized by IFN-γ responses priming dendritic cell fibroblast crosstalk to promote fibrosis

Pansclerotic morphea (PSM) is a rare, devastating disease characterized by extensive soft tissue fibrosis, secondary contractions, and significant morbidity. PSM pathogenesis is unknown, and aggressive immunosuppressive treatments rarely slow disease progression. We aimed to characterize molecular mechanisms driving PSM and to identify therapeutically targetable pathways by performing single-cell and spatial RNA-Seq on 7 healthy controls and on lesional and nonlesional skin biopsies of a patient with PSM 12 months apart. We then validated our findings using immunostaining and in vitro approaches. Fibrotic skin was characterized by prominent type II IFN response, accompanied by infiltrating myeloid cells, B cells, and T cells, which were the main IFN-γ source. We identified unique CXCL9+ fibroblasts enriched in PSM, characterized by increased chemokine expression, including CXCL9, CXCL10, and CCL2. CXCL9+ fibroblasts were related to profibrotic COL8A1+ myofibroblasts, which had enriched TGF-β response. In vitro, TGF-β and IFN-γ synergistically increased CXCL9 and CXCL10 expression, contributing to the perpetuation of IFN-γ responses. Furthermore, cell-to-cell interaction analyses revealed cDC2B DCs as a key communication hub between CXCL9+ fibroblasts and COL8A1+ myofibroblasts. These results define PSM as an inflammation-driven condition centered on type II IFN responses. This work identified key pathogenic circuits between T cells, cDC2Bs, and myofibroblasts, and it suggests that JAK1/2 inhibition is a potential therapeutic option in PSM.

Emergent Peptides of the Antifibrotic Arsenal: Taking Aim at Myofibroblast Promoting Pathways

Myofibroblasts are the principal effector cells driving fibrosis, and their accumulation in tissues is a fundamental feature of fibrosis. Essential pathways have been identified as being central to promoting myofibroblast differentiation, revealing multiple targets for intervention. Compared with large proteins and antibodies, peptide-based therapies have transpired to serve as biocompatible and cost-effective solutions to exert biomimicry, agonistic, and antagonistic activities with a high degree of targeting specificity and selectivity. In this review, we summarize emergent antifibrotic peptides and their utilization for the targeted prevention of myofibroblasts. We then highlight recent studies on peptide inhibitors of upstream pathogenic processes that drive the formation of profibrotic cell phenotypes. We also briefly discuss peptides from non-mammalian origins that show promise as antifibrotic therapeutics. Finally, we discuss the future perspectives of peptide design and development in targeting myofibroblasts to mitigate fibrosis.

Endothelin-1 induces connective tissue growth factor expression in human lung fibroblasts by disrupting HDAC2/Sin3A/MeCP2 corepressor complex

BACKGROUND

Reduction of histone deacetylase (HDAC) 2 expression and activity may contribute to amplified inflammation in patients with severe asthma. Connective tissue growth factor (CTGF) is a key mediator of airway fibrosis in severe asthma. However, the role of the HDAC2/Sin3A/methyl-CpG-binding protein (MeCP) 2 corepressor complex in the regulation of CTGF expression in lung fibroblasts remains unclear.

METHODS

The role of the HDAC2/Sin3A/MeCP2 corepressor complex in endothelin (ET)-1-stimulated CTGF production in human lung fibroblasts (WI-38) was investigated. We also evaluated the expression of HDAC2, Sin3A and MeCP2 in the lung of ovalbumin-induced airway fibrosis model.

RESULTS

HDAC2 suppressed ET-1-induced CTGF expression in WI-38 cells. ET-1 treatment reduced HDAC2 activity and increased H3 acetylation in a time-dependent manner. Furthermore, overexpression of HDAC2 inhibited ET-1-induced H3 acetylation. Inhibition of c-Jun N-terminal kinase, extracellular signal-regulated kinase, or p38 attenuated ET-1-induced H3 acetylation by suppressing HDAC2 phosphorylation and reducing HDAC2 activity. Overexpression of both Sin3A and MeCP2 attenuated ET-1-induced CTGF expression and H3 acetylation. ET-1 induced the disruption of the HDAC2/Sin3A/MeCP2 corepressor complex and then prompted the dissociation of HDAC2, Sin3A, and MeCP2 from the CTGF promoter region. Overexpression of HDAC2, Sin3A, or MeCP2 attenuated ET-1-stimulated AP-1-luciferase activity. Moreover, Sin3A- or MeCP2-suppressed ET-1-induced H3 acetylation and AP-1-luciferase activity were reversed by transfection of HDAC2 siRNA. In an ovalbumin-induced airway fibrosis model, the protein levels of HDAC2 and Sin3A were lower than in the control group; however, no significant difference in MeCP2 expression was observed. The ratio of phospho-HDAC2/HDAC2 and H3 acetylation in the lung tissue were higher in this model than in the control group. Overall, without stimulation, the HDAC2/Sin3A/MeCP2 corepressor complex inhibits CTGF expression by regulating H3 deacetylation in the CTGF promoter region in human lung fibroblasts. With ET-1 stimulation, the HDAC2/Sin3A/MeCP2 corepressor complex is disrupted and dissociated from the CTGF promoter region; this is followed by AP-1 activation and the eventual initiation of CTGF production.

CONCLUSIONS

The HDAC2/Sin3A/MeCP2 corepressor complex is an endogenous inhibitor of CTGF in lung fibroblasts. Additionally, HDAC2 and Sin3A may be of greater importance than MeCP2 in the pathogenesis of airway fibrosis.

Inositol possesses antifibrotic activity and mitigates pulmonary fibrosis

BACKGROUND

Myo-inositol (or inositol) and its derivatives not only function as important metabolites for multiple cellular processes but also act as co-factors and second messengers in signaling pathways. Although inositol supplementation has been widely studied in various clinical trials, little is known about its effect on idiopathic pulmonary fibrosis (IPF). Recent studies have demonstrated that IPF lung fibroblasts display arginine dependency due to loss of argininosuccinate synthase 1 (ASS1). However, the metabolic mechanisms underlying ASS1 deficiency and its functional consequence in fibrogenic processes are yet to be elucidated.

METHODS

Metabolites extracted from primary lung fibroblasts with different ASS1 status were subjected to untargeted metabolomics analysis. An association of ASS1 deficiency with inositol and its signaling in lung fibroblasts was assessed using molecular biology assays. The therapeutic potential of inositol supplementation in fibroblast phenotypes and lung fibrosis was evaluated in cell-based studies and a bleomycin animal model, respectively.

RESULTS

Our metabolomics studies showed that ASS1-deficient lung fibroblasts derived from IPF patients had significantly altered inositol phosphate metabolism. We observed that decreased inositol-4-monophosphate abundance and increased inositol abundance were associated with ASS1 expression in fibroblasts. Furthermore, genetic knockdown of ASS1 expression in primary normal lung fibroblasts led to the activation of inositol-mediated signalosomes, including EGFR and PKC signaling. Treatment with inositol significantly downregulated ASS1 deficiency-mediated signaling pathways and reduced cell invasiveness in IPF lung fibroblasts. Notably, inositol supplementation also mitigated bleomycin-induced fibrotic lesions and collagen deposition in mice.

CONCLUSION

These findings taken together demonstrate a novel function of inositol in fibrometabolism and pulmonary fibrosis. Our study provides new evidence for the antifibrotic activity of this metabolite and suggests that inositol supplementation may be a promising therapeutic strategy for IPF.

An adhesive gelatin-coated small intestinal submucosa composite hydrogel dressing aids wound healing

It is a challenging clinical task to determine how to repair large-area skin defects better. Traditional wound dressings (e.g., cotton and gauze) can only be used as a dressing; consequently, there is an increasing demand for wound dressings with additional properties (i.e., antibacterial and pro-repair) in clinical practice. In this study, a composite hydrogel with o-nitrobenzene-modified gelatin-coated decellularized small intestinal submucosa (GelNB@SIS) was designed for the repair of skin injuries. SIS is a natural extracellular matrix with a 3D microporous structure and also contains high levels of growth factors and collagen. GelNB provides this material photo-triggering tissue adhesive property. The structure, tissue adhesion, cytotoxicity, and bioactivity to cells were investigated. Based on in vivo study and histological analysis, we found the combination of GelNB and SIS improved the healing process by promoting vascular renewal, dermal remodeling, and epidermal regeneration. Based on our findings, GelNB@SIS is a promising candidate for tissue repair applications.

The link between immunity and hypertension in the kidney and heart

Hypertension is the primary cause of cardiovascular disease, which is a leading killer worldwide. Despite the prevalence of this non-communicable disease, still between 90% and 95% of cases are of unknown or multivariate cause ("essential hypertension"). Current therapeutic options focus primarily on lowering blood pressure through decreasing peripheral resistance or reducing fluid volume, but fewer than half of hypertensive patients can reach blood pressure control. Hence, identifying unknown mechanisms causing essential hypertension and designing new treatment accordingly are critically needed for improving public health. In recent years, the immune system has been increasingly implicated in contributing to a plethora of cardiovascular diseases. Many studies have demonstrated the critical role of the immune system in the pathogenesis of hypertension, particularly through pro-inflammatory mechanisms within the kidney and heart, which, eventually, drive a myriad of renal and cardiovascular diseases. However, the precise mechanisms and potential therapeutic targets remain largely unknown. Therefore, identifying which immune players are contributing to local inflammation and characterizing pro-inflammatory molecules and mechanisms involved will provide promising new therapeutic targets that could lower blood pressure and prevent progression from hypertension into renal or cardiac dysfunction.

Model to Inhibit Contraction in Third-Degree Burns Employing Split-Thickness Skin Graft and Administered Bone Marrow-Derived Stem Cells

Third-degree burns typically result in pronounced scarring and contraction in superficial and deep tissues. Established techniques such as debridement and grafting provide benefit in the acute phase of burn therapy, nevertheless, scar and contraction remain a challenge in deep burns management. Our ambition is to evaluate the effectiveness of novel cell-based therapies, which can be implemented into the standard of care debridement and grafting procedures. Twenty-seven third-degree burn wounds were created on the dorsal area of Red Duroc pig. After 72 h, burns are surgically debrided using a Weck knife. Split-thickness skin grafts (STSGs) were then taken after debridement and placed on burn scars combined with bone marrow stem cells (BM-MSCs). Biopsy samples were taken on days 17, 21, and 45 posttreatment for evaluation. Histological analysis revealed that untreated control scars at 17 days are more raised than burns treated with STSGs alone and/or STSGs with BM-MSCs. Wounds treated with skin grafts plus BM-MSCs appeared thinner and longer, indicative of reduced contraction. qPCR revealed some elevation of α-SMA expression at day 21 and Collagen Iα2 in cells derived from wounds treated with skin grafts alone compared to wounds treated with STSGs + BM-MSCs. We observed a reduction level of TGFβ-1 expression at days 17, 21, and 45 in cells derived from wounds treated compared to controls. These results, where the combined use of stem cells and skin grafts stimulate healing and reduce contraction following third-degree burn injury, have a potential as a novel therapy in the clinic.

Framing Heartaches: The Cardiac ECM and the Effects of Age

The cardiac extracellular matrix (ECM) is involved in several pathological conditions, and age itself is also associated with certain changes in the heart: it gets larger and stiffer, and it develops an increased risk of abnormal intrinsic rhythm. This, therefore, makes conditions such as atrial arrythmia more common. Many of these changes are directly related to the ECM, yet the proteomic composition of the ECM and how it changes with age is not fully resolved. The limited research progress in this field is mainly due to the intrinsic challenges in unravelling tightly bound cardiac proteomic components and also the time-consuming and costly dependency on animal models. This review aims to give an overview of the composition of the cardiac ECM, how different components aid the function of the healthy heart, how the ECM is remodelled and how it is affected by ageing.

Biomechanical and Mechanobiological Drivers of the Transition From PostCapillary Pulmonary Hypertension to Combined Pre-/PostCapillary Pulmonary Hypertension

Combined pre-/postcapillary pulmonary hypertension (Cpc-PH), a complication of left heart failure, is associated with higher mortality rates than isolated postcapillary pulmonary hypertension alone. Currently, knowledge gaps persist on the mechanisms responsible for the progression of isolated postcapillary pulmonary hypertension (Ipc-PH) to Cpc-PH. Here, we review the biomechanical and mechanobiological impact of left heart failure on pulmonary circulation, including mechanotransduction of these pathological forces, which lead to altered biological signaling and detrimental remodeling, driving the progression to Cpc-PH. We focus on pathologically increased cyclic stretch and decreased wall shear stress; mechanotransduction by endothelial cells, smooth muscle cells, and pulmonary arterial fibroblasts; and signaling-stimulated remodeling of the pulmonary veins, capillaries, and arteries that propel the transition from Ipc-PH to Cpc-PH. Identifying biomechanical and mechanobiological mechanisms of Cpc-PH progression may highlight potential pharmacologic avenues to prevent right heart failure and subsequent mortality.

Promotion of Lymphangiogenesis by Targeted Delivery of VEGF-C Improves Diabetic Wound Healing

Chronic wounds represent a major therapeutic challenge. Lymphatic vessel function is impaired in chronic ulcers but the role of lymphangiogenesis in wound healing has remained unclear. We found that lymphatic vessels are largely absent from chronic human wounds as evaluated in patient biopsies. Excisional wound healing studies were conducted using transgenic mice with or without an increased number of cutaneous lymphatic vessels, as well as antibody-mediated inhibition of lymphangiogenesis. We found that a lack of lymphatic vessels mediated a proinflammatory wound microenvironment and delayed wound closure, and that the VEGF-C/VEGFR3 signaling axis is required for wound lymphangiogenesis. Treatment of diabetic mice (db/db mice) with the F8-VEGF-C fusion protein that targets the alternatively spliced extra domain A (EDA) of fibronectin, expressed in remodeling tissue, promoted wound healing, and potently induced wound lymphangiogenesis. The treatment also reduced tissue inflammation and exerted beneficial effects on the wound microenvironment, including myofibroblast density and collagen deposition. These findings indicate that activating the lymphatic vasculature might represent a new therapeutic strategy for treating chronic non-healing wounds.

Biological properties and surgical applications of the human amniotic membrane

The amniotic membrane (AM) is the inner part of the placenta. It has been used therapeutically for the last century. The biological proprieties of AM include immunomodulatory, anti-scarring, anti-microbial, pro or anti-angiogenic (surface dependent), and tissue growth promotion. Because of these, AM is a functional tissue for the treatment of different pathologies. The AM is today part of the treatment for various conditions such as wounds, ulcers, burns, adhesions, and skin injury, among others, with surgical resolution. This review focuses on the current surgical areas, including gynecology, plastic surgery, gastrointestinal, traumatology, neurosurgery, and ophthalmology, among others, that use AM as a therapeutic option to increase the success rate of surgical procedures. Currently there are articles describing the mechanisms of action of AM, some therapeutic implications and the use in surgeries of specific surgical areas, this prevents knowing the therapeutic response of AM when used in surgeries of different organs or tissues. Therefore, we described the use of AM in various surgical specialties along with the mechanisms of action, helping to improve the understanding of the therapeutic targets and achieving an adequate perspective of the surgical utility of AM with a particular emphasis on regenerative medicine.

Drug Resistance: The Role of Exosomal miRNA in the Microenvironment of Hematopoietic Tumors

Extracellular vesicles (EVs), including exosomes, have an important role thanks to their ability to communicate and exchange information between tumor cells and the tumor microenvironment (TME), and have also been associated with communicating anti-cancer drug resistance (DR). The increase in proliferation of cancer cells alters oxygen levels, which causes hypoxia and results in a release of exosomes by the cancer cells. In this review, the results of studies examining the role of exosomal miRNA in DR, and their mechanism, are discussed in detail in hematological tumors: leukemia, lymphoma, and multiple myeloma. In conclusion, we underline the exosome's function as a possible drug delivery vehicle by understanding its cargo. Engineered exosomes can be used to be more specific for personalized therapy.

A Novel Mechanism Underlying the Inhibitory Effects of Trastuzumab on the Growth of HER2-Positive Breast Cancer Cells

To improve the efficacy of trastuzumab, it is essential to understand its mechanism of action. One of the significant issues that makes it difficult to determine the precise mechanism of trastuzumab action is the formation of various HER receptor dimers in HER2-positive breast cancer cells. So far, studies have focused on the role of HER2-HER3 heterodimers, and little is known regarding EGFR-HER2 heterodimers. Here, we study the role of trastuzumab on the cell signaling and cell proliferation mediated by EGFR-HER2 heterodimers in BT474 and SRBR3 cells. EGF stimulates the formation of both EGFR homodimer and EGFR-HER2 heterodimer. Trastuzumab only binds to HER2, not EGFR. Therefore, any effects of trastuzumab on EGF-induced activation of EGFR, HER2, and downstream signaling proteins, as well as cell proliferation, are through its effects on EGFR-HER2 heterodimers. We show that trastuzumab inhibits EGF-induced cell proliferation and cell cycle progression in BT474 and SKBR3 cells. Interestingly trastuzumab strongly inhibits EGF-induced Akt phosphorylation and slightly inhibits EGF-induced Erk activation, in both BT474 and SKBR3 cells. These data suggest the presence of a novel mechanism that allows trastuzumab to inhibit EGR-induced Akt activation and cell proliferation, without blocking EGF-induced EGFR-HER2 heterodimerization and activation. We show that trastuzumab inhibits EGF-induced lipid raft localization of the EGFR-HER2 heterodimer. Disruption of the lipid raft with MβCD blocks HER2-mediated AKT activation in a similar way to trastuzumab. MβCD and trastuzumab synergically inhibit AKT activation. We conclude that trastuzumab inhibits EGF-induced lipid raft localization of EGFR-HER2 heterodimer, which leads to the inhibition of Akt phosphorylation and cell proliferation, without blocking the formation and phosphorylation of the EGFR-HER2 heterodimer.

Mechanisms of PDAC subtype heterogeneity and therapy response

Pancreatic ductal adenocarcinoma (PDAC) is clinically challenging due to late diagnosis and resistance to therapy. Two major PDAC subtypes have been defined based on malignant epithelial cell gene expression profiles; the basal-like/squamous subtype is associated with a worse prognosis and therapeutic resistance as opposed to the classical subtype. Subtype specification is not binary, consistent with plasticity of malignant cell phenotype. PDAC heterogeneity and plasticity reflect partly malignant cell-intrinsic transcriptional and epigenetic regulation. However, the stromal and immune compartments of the tumor microenvironment (TME) also determine disease progression and therapy response. It is evident that integration of intrinsic and extrinsic factors can dictate subtype heterogeneity, and thus, delineating the pathways involved can help to reprogram PDAC towards a classical/druggable subtype.

Crosstalk between cytotoxic CD8+ T cells and stressed cardiomyocytes triggers development of interstitial cardiac fibrosis in hypertensive mouse hearts

Aims

Cardiac fibrosis is central to heart failure (HF), especially HF with preserved ejection fraction (HFpEF), often caused by hypertension. Despite fibrosis causing diastolic dysfunction and impaired electrical conduction, responsible for arrhythmia-induced sudden cardiac death, the mechanisms are poorly defined and effective therapies are lacking. Here we show that crosstalk between cardiac cytotoxic memory CD8+ T cells and overly stressed cardiomyocytes is essential for development of non-ischemic hypertensive cardiac fibrosis.

Methods and results

CD8 T cell depletion in hypertensive mice, strongly attenuated CF, reduced cardiac apoptosis and improved ventricular relaxation. Interaction between cytotoxic memory CD8+ T cells and overly stressed cardiomyocytes is highly dependent on the CD8+ T cells expressing the innate stress-sensing receptor NKG2D and stressed cardiomyocytes expressing the NKG2D activating ligand RAE-1. The interaction between NKG2D and RAE-1 results in CD8+ T cell activation, release of perforin, cardiomyocyte apoptosis, increased numbers of TGF-β1 expressing macrophages and fibrosis. Deleting NKG2D or perforin from CD8+ T cells greatly attenuates these effects. Activation of the cytoplasmic DNA-STING-TBK1-IRF3 signaling pathway in overly stressed cardiomyocytes is responsible for elevating RAE-1 and MCP-1, a macrophage attracting chemokine. Inhibiting STING activation greatly attenuates cardiomyocyte RAE-1 expression, the cardiomyocyte apoptosis, TGF-β1 and fibrosis.

Conclusion

Our data highlight a novel pathway by which CD8 T cells contribute to an early triggering mechanism in CF development; preventing CD8+ T cell activation by inhibiting the cardiomyocyte RAE-1-CD8+ T cell-NKG2D axis holds promise for novel therapeutic strategies to limit hypertensive cardiac fibrosis.

Glutamine uptake and catabolism is required for myofibroblast formation and persistence

BACKGROUND

Fibrosis and extracellular matrix remodeling are mediated by resident cardiac fibroblasts (CFs). In response to injury, fibroblasts activate, differentiating into specialized synthetic and contractile myofibroblasts producing copious extracellular matrix proteins (e.g., collagens). Myofibroblast persistence in chronic diseases, such as HF, leads to progressive cardiac dysfunction and maladaptive remodeling. We recently reported that an increase in αKG (alpha-ketoglutarate) bioavailability, which contributes to enhanced αKG-dependent lysine demethylase activity and chromatin remodeling, is required for myofibroblast formation. Therefore, we aimed to determine the substrates and metabolic pathways contributing to αKG biosynthesis and their requirement for myofibroblast formation.

METHODS

Stable isotope metabolomics identified glutaminolysis as a key metabolic pathway required for αKG biosynthesis and myofibroblast formation, therefore we tested the effects of pharmacologic inhibition (CB-839) or genetic deletion of glutaminase (Gls1-/-) on myofibroblast formation in both murine and human cardiac fibroblasts. We employed immunofluorescence staining, functional gel contraction, western blotting, and bioenergetic assays to determine the myofibroblast phenotype.

RESULTS

Carbon tracing indicated enhanced glutaminolysis mediating increased αKG abundance. Pharmacological and genetic inhibition of glutaminolysis prevented myofibroblast formation indicated by a reduction in αSMA+ cells, collagen gel contraction, collagen abundance, and the bioenergetic response. Inhibition of glutaminolysis also prevented TGFβ-mediated histone demethylation and supplementation with cell-permeable αKG rescued the myofibroblast phenotype. Importantly, inhibition of glutaminolysis was sufficient to prevent myofibroblast formation in CFs isolated from the human failing heart.

CONCLUSIONS

These results define glutaminolysis as necessary for myofibroblast formation and persistence, providing substantial rationale to evaluate several new therapeutic targets to treat cardiac fibrosis.

Anti-Fibrotic Potential of Tomentosenol A, a Constituent of Cerumen from the Australian Native Stingless Bee, Tetragonula carbonaria

Bioactivity-guided fractionation was used to isolate two compounds, tomentosenol A (1) and torellianone A (2), from a cerumen extract from Tetragonula carbonaria. The anti-fibrotic activity of these compounds was examined using human cultured neonatal foreskin fibroblasts (NFF) and immortalised keratinocytes (HaCaTs). Tomentosenol A (1), inhibited NFF and HaCaT cell proliferation and prevented NFF and HaCaT scratch wound repopulation at 12.5-25 µM concentrations. These inhibitory effects were associated with reduced cell viability, determined by tetrazolium dye (MTT) and sulforhodamine B (SRB) assays. Compound 1 further inhibited transforming growth factor-β₁ (TGF-β₁)-stimulated, NFF-myofibroblast differentiation and soluble collagen production; and was an effective scavenger of the model oxidant, 2,2-diphenyl-1-picrylhydrazyl (DPPH·), with an EC₅₀ value of 44.7 ± 3.1 µM. These findings reveal significant anti-fibrotic potential for cerumen-derived tomentosenol A (1).

Untangling the Extracellular Matrix of Idiopathic Epiretinal Membrane: A Path Winding among Structure, Interactomics and Translational Medicine

Idiopathic epiretinal membranes (iERMs) are fibrocellular sheets of tissue that develop at the vitreoretinal interface. The iERMs consist of cells and an extracellular matrix (ECM) formed by a complex array of structural proteins and a large number of proteins that regulate cell–matrix interaction, matrix deposition and remodelling. Many components of the ECM tend to produce a layered pattern that can influence the tractional properties of the membranes. We applied a bioinformatics approach on a list of proteins previously identified with an MS-based proteomic analysis on samples of iERM to report the interactome of some key proteins. The performed pathway analysis highlights interactions occurring among ECM molecules, their cell receptors and intra- or extracellular proteins that may play a role in matrix biology in this special context. In particular, integrin β1, cathepsin B, epidermal growth factor receptor, protein-glutamine gamma-glutamyltransferase 2 and prolow-density lipoprotein receptor-related protein 1 are key hubs in the outlined protein–protein cross-talks. A section on the biomarkers that can be found in the vitreous humor of patients affected by iERM and that can modulate matrix deposition is also presented. Finally, translational medicine in iERM treatment has been summed up taking stock of the techniques that have been proposed for pharmacologic vitreolysis.

Modified hyaluronic acid-collagen matrices trigger efficient gene transfer and prohealing behavior in fibroblasts for improved wound repair

Growth factor therapy has demonstrated great promise for chronic wound repair, but controlling growth factor activity and cell phenotype over desired time frames remains a critical challenge. In this study, we developed a gene-activated hyaluronic acid-collagen matrix (GAHCM) comprising DNA/polyethylenimine (PEI) polyplexes retained on hyaluronic acid (HA)-collagen hydrogels using collagen mimetic peptides (CMPs). We hypothesized that manipulating both the number of CMP-collagen tethers and the ECM composition would provide a powerful strategy to control growth factor gene transfer kinetics while regulating cell behavior, resulting in enhanced growth factor activity for wound repair. We observed that polyplexes with 50% CMP-modified PEI (50 CP) showed enhanced retention of polyplexes in HCM hydrogels by 2.7-fold as compared to non-CMP modified polyplexes. Moreover, the incorporation of HA in the hydrogel promoted a significant increase in gene transfection efficiency based upon analysis of Gaussia luciferase (GLuc) reporter gene expression, and gene expression could be attenuated by blocking HA-CD44 signaling. Furthermore, when fibroblasts were exposed to vascular endothelial growth factor-A (VEGF-A)-GAHCM, the 50 CP matrix facilitated sustained VEGF-A production for up to 7 days, with maximal expression at day 5. Application of these VEGF-A-50 CP samples stimulated prolonged pro-healing responses, including the TGF-β1-induced myofibroblast-like phenotypes and enhanced closure of murine splinted wounds. Overall, these findings demonstrate the use of ECM-based materials to stimulate efficient gene transfer and regulate cellular phenotype, resulting in improved control of growth factor activity for wound repair. GAHCM have significant potential to overcome key challenges in growth factor therapy for regenerative medicine. STATEMENT OF SIGNIFICANCE: Despite great promise for growth factor therapies in wound treatment, controlling growth factor activity and providing a microenvironment for cells that maximizes growth factor signaling have continued to limit the success of existing formulations. Our GAHCM strategy, combining CMP gene delivery and hyaluronic acid-collagen matrix, enabled enhanced wound healing efficacy via the combination of controlled and localized growth factor expression and matrix-mediated regulation of cell behavior. Incorporation of CMPs and HA in the same matrix synergistically enhanced VEGF activity as compared with simpler matrices. Accordingly, GAHCM will advance our ability to leverage growth factor signaling for wound healing, resulting in new long-term treatments for recalcitrant wounds.

Expression of CD44, Transforming Growth Factor-β, and Matrix Metalloproteinases in Women With Pelvic Organ Prolapse

Background

Defects in the pelvic floor connective tissue may underlie the etiology of pelvic organ prolapse (POP). We hypothesized that the expression of proteins regulating extracellular matrix turnover is altered in the uterosacral ligament of women with POP. We compared the expression of CD44, transforming growth factor (TGF)-β, and matrix metalloproteinases (MMPs) 2/9 in women with and without POP.

Methods and Results

This matched case-control study included 30 postmenopausal women, with POP stage 2 and higher according to the POP quantification system, and 30 postmenopausal women without POP. Immunohistochemical analyses of the uterosacral ligament specimens obtained after hysterectomy were performed to determine CD44, TGF-β, MMP-2, and MMP-9 expression. The expression was quantified using ImageJ software, and the association between prolapse occurrence and risk factors was evaluated using Spearman's correlation analysis. CD44 expressions were significantly lower (p < 0.05), whereas MMP-2 and MMP-9 expression was higher (p < 0.0001 and p < 0.05, respectively), in the POP group than in the control group. The expression of TGF-β was similar in both groups. The occurrence of uterine prolapse was positively correlated with age, postmenopausal age, and MMP-2 and MMP-9 expression (p < 0.01) and negatively correlated with CD44 expression (p < 0.05).

Conclusion

CD44, MMP-2, and MMP-9 may play critical roles in the pathogenesis of POP and may be candidate biomarkers of POP progression.