Extracellular Matrix Synthesis Research Articles

Harnessing nature's arsenal: Targeting the TGF-β/Smad Cascade with novel natural anti-fibrotic agents.

Hepatic fibrosis is a wound healing response that leads to excessive deposition of extracellular matrix (ECM) due to sustained liver injury. Hepatic stellate cells (HSCs) are key players in ECM synthesis, with the TGF-β/Smad signaling pathway being central to their activation. Despite advances in understanding the pathogenesis of hepatic fibrosis, effective anti-fibrotic therapies are still lacking. This treatise conducts a comprehensive review of the literature on the hepatoprotective effects of natural products, including natural medicine compounds, herbal extracts, and polysaccharides. The focus is on their ability to modulate the TGF-β pathway, which is critical in the activation of HSCs and ECM synthesis in hepatic fibrosis. The review identifies a variety of natural products that have shown promise in inhibiting the TGF-β/Smad signaling cascade, thereby reducing the activation of HSCs and ECM accumulation. These findings highlight the potential of these natural products as therapeutic agents in the treatment of hepatic fibrosis. The exploration of natural products as modulators of the TGF-β pathway presents a novel avenue for both clinical and preclinical research into hepatic fibrosis. Further investigation is warranted to fully understand the mechanisms of action and to develop these compounds into effective anti-fibrotic pharmaceuticals.

An Exploratory Study of PN HPT for Treating Postsurgical Atrophic and Depressed Scars.

Postsurgical atrophic scars tend to respond poorly to treatments, especially non-energy-based ones. Hydrophilic PN HPT (Polynucleotides High Purification Technology) injected intradermally is a non-energy-based option with an immediate volume-enhancing effect that indirectly improves the fibroblast synthesis of collagen and extracellular matrix. The PN HPT ingredient has the further benefit of a dermal "priming" effect that enhances the efficacy of other scar treatments. Verify retrospectively, with advanced techniques, the efficacy of PN HPT monotherapy as postsurgical scar treatment. Retrospective data collection in 18- to 65-year-old women with moderate-to-severe atrophic scars after mammary surgery undergoing a five-session intradermal treatment course with 0.75% PN HPT gel formulation in single-use syringes starting 6 months after surgery. Primary retrospective efficacy parameter: changes in scar morphology and symptom severity after three and 6 months (modified Vancouver Scar Scale, mVSS). Secondary efficacy parameters: roughness score 6 months after baseline (Antera 3D CS tridimensional skin analysis system) and Global Aesthetic Improvement Scale (GAIS, Investigator and Patient subscales) after three and 6 months. Total mean mVSS highly significantly improved from 11.2 ± 1.92 at baseline to 7.0 ± 1.68 and 6.9 ± 1.55 after three and 6 months, respectively; the mean Antera 3D CS roughness score improved from 13.5 ± 4.14 to 10.0 ± 3.49 after 6 months. After three and 6 months, the GAIS subscores for investigators and cohort subjects were identical (3.0 ± 0.81 and 3.0 ± 0.72, respectively). The photographic documentation supported the previous results. In monotherapy, the intradermal PN HPT ingredient seems to quickly and safely relieve the burden of postsurgical atrophic scars. However, the lack of a formal parallel control group is a severe limitation. The objective quantitative measurements confirmed the long-lasting benefits.

Single-nucleus transcriptome profiling provides insights into the pathophysiology of adhesive arachnoiditis.

Adhesive arachnoiditis (AA) is a rare form of chronic degenerative pathology associated with persistent inflammation in the arachnoid matter of the spinal cord. Despite the existing knowledge, the detailed pathological mechanisms underlying AA are not fully understood. This study aimed to elucidate through comprehensive single nuclei RNA sequencing (snRNA-seq) to delineate the transcriptomic landscape of AA. From six arachnoid membrane samples, a total of 52,886 cells met the quality control standards for analysis. The main cell populations identified with specific gene markers were as follows: fibroblasts, glial cells, microglial cells, endothelial cells, mural cells, plasma cells, and T cells. Downstream analysis of fibroblasts, glial cells, and microglial cells was performed. Notably, fibroblast subsets 1 and 3 demonstrated a strong association with AA. Among them, subcluster 3 demonstrated elevated expression of genes COL1A1, COL3A1, and FN1, indicative of enhanced Wnt/β-catenin and extracellular matrix (ECM) synthesis pathways. Subcluster 3 was predicted to progressively transform into subcluster 1. In subcluster 1, there was a significant upregulation of genes such as BMP and ALPL, signaling enhanced activation of calcification-related pathways. This was highly relevant to end-stage arachnoid ossification formation. After being activated, microglial cells transformed into inflammatory disease-associated microglial cells and continued to express high levels of chemokines CCL2, CCL4, IL-1β, and other inflammatory factors NAMPT, INPP5D and NLRP3. This might be the main reason why AA recurrence is frequently observed in patients. These insights enhance our understanding of the pathological progression of AA and may contribute to the identification of novel therapeutic targets.

Surface Molecular Markers for the Isolation of Viable Fibroblast Subpopulations in the Female Reproductive Tract: A Comprehensive Review.

Advancements in single-cell analyzis technologies, particularly single-cell RNA sequencing (scRNA-seq) and Fluorescence-Activated Cell Sorting (FACS), have enabled the analyzis of cellular diversity by providing resolutions that were not available previously. These methods enable the simultaneous analyzis of thousands of individual transcriptomes, facilitating the classification of cells into distinct subpopulations, based on transcriptomic differences, adding a new level of complexity to biomolecular and medical research. Fibroblasts, despite being one of the most abundant cell types in the human body and forming the structural backbone of tissues and organs, remained poorly characterized for a long time. This is largely due to the high morphological similarity between different types of fibroblasts and the lack of specific markers to identify distinct subpopulations. Once thought to be cells responsible solely for the synthesis of extracellular matrix (ECM) components, fibroblasts are now recognized as active participants in diverse physiological processes, including inflammation and antimicrobial responses. However, defining the molecular profile of fibroblast subpopulations remains a significant challenge. In this comprehensive review, which is based on over two thousand research articles, we focus on the identification and characterization of fibroblast subpopulations and their specific surface markers, with an emphasis on their potential as molecular targets for selective cell isolation. By analyzing surface markers, alongside intra- and extracellular protein profiles, we identified multiple fibroblast subtypes within the female reproductive system. These subtypes exhibit distinct molecular signatures and functional attributes, shaped by their anatomical localization and the surrounding physiological or pathological conditions. Our findings underscore the heterogeneity of fibroblasts and their diverse roles in various biological contexts. This improved understanding of fibroblast subpopulations paves the way for innovative diagnostic and therapeutic strategies, offering the potential for precision targeting of specific fibroblast subsets in clinical applications.

ВЛИЯНИЕ СУЛЬФАТИАЗОЛА СЕРЕБРА НА ЗАЖИВЛЕНИЕ КОЖНЫХ РАН, ОБРАЗУЮЩИХСЯ ПРИ ПРОРЕЗЫВАНИИ СПИЦАМИ АППАРАТОВ НАРУЖНОЙ ФИКСАЦИИ

The study of the healing mechanisms of skin wounds resulting from damage to the skin by transosseous needles of external fixation devices in the treatment of osteoarticular pathology with the aim of further targeted correction of these processes is one of the urgent tasks of modern traumatology and orthopedics. The effect of silver sulfathiazole, recommended for the prevention of infectious complications, on the healing of this type of wound has not been studied previously. The aim of the study was to investigate the effect of silver sulfathiazole on the healing of skin wounds formed during the cutting of external fixation devices by pins. The experimental study was performed on 35 sexually mature male Wistar rats. Modeling of a skin wound formed during the cutting of external fixation devices by pins was carried out in sterile operating room conditions, under drug anesthesia of animals that underwent transosseous osteosynthesis of the femur using an original design of the external fixation device. By tractional movement of the proximal pin with a dosed stretching of the supports at a rate of 1 mm in 4 steps, tension and cutting of the skin were carried out for 10 days (the distraction period), then the device was in a static position for 15 days (the period of fixation of the limb in the device), after which the device was dismantled and observation was carried out for another 30 days. The animals were divided into 2 groups. In the control group, the simulated wound healed under natural healing conditions; in the experimental group, silver sulfathiazole applications were performed twice daily during the distraction period. Skin wounds were examined using light microscopy and morphometry after 10 days of distraction, 15 days of fixation, and 30 days after the apparatus was removed. The thickness of the epidermis, dermis, and the numerical density of the sebaceous glands and hair follicles were measured on digital images of histological preparations stained with hematoxylin and eosin. The volume density of elastic fibers was determined on preparations stained with orcein according to Tenzer-Unn. The obtained quantitative data were subjected to statistical analysis. The study showed that the formation of a skin wound with transosseous pins is accompanied by tissue tension. Healing of this type of wound occurs with a delay in epithelialization and an increase in the duration of the inflammatory phase. This affects the mechanisms of extracellular matrix synthesis and leads to the formation of scar tissue in the area of damage. The use of silver sulfathiazole applications promotes accelerated wound closure by epithelium, a reduction in the period of inflammation, normalization of elastin synthesis, and a decrease in cicatricial changes in the skin regenerate.

Coordination of Glucose and Glutamine Metabolism in Tendon is Lost in Aging.

Tendinopathy is an age-associated degenerative disease characterized by a loss in extracellular matrix (ECM). Since glucose and glutamine metabolism is critical to amino acid synthesis and known to be altered in aging, we sought to investigate if age-related changes in metabolism are linked to changes in ECM remodeling. We exposed young and aged tendon explants to various concentrations of glucose and glutamine to observe changes in metabolic processing (enzyme levels, gene expression, etc.) and matrix biosynthesis. Interestingly, we found that glutamine processing is affected by glucose levels, but this effect was lost with aging. ECM synthesis was altered in a protein-dependent manner by increased glucose and glutamine levels in young tendons. However, these changes were not conserved in aged tendons. Overall, our work suggests that glucose and glutamine metabolism is important for ECM homeostasis, and age-related changes in nutrient metabolism could be a key driver of tendon degeneration.

Soluble Proteins From Conventional and Organic Eggshell Membranes With Different Proteomic Profiles Show Similar InVitro Biofunctions.

The eggshell membrane (ESM), resembling the extracellular matrix (ECM), acts as a protective barrier against bacterial invasion and offers various biofunctions due to its porous structure and protein-rich composition, such as ovalbumin, ovotransferrin, collagen, soluble protein, and antimicrobial proteins. However, the structure of ESM primarily comprises disulfide bonds and heterochains, which poses a challenge for protein solubilization/extraction. Therefore, the method of dissolving and extracting bioactive protein components from ESM has significant potential value and importance for exploring the reuse of egg waste and environmental protection. In this study, soluble ESM proteins (SEPs) were extracted from conventional (industrial-fed) and organic (free-grounded) using an acidic 3-mercaptopropionic acid (3-MPA) extraction strategy. FTIR was employed to monitor the chemical changes in the ESM, while LC-MS/MS was used to conduct the proteomic analysis. The biocompatibility and effects of SEP cocktails on ECM synthesis were also investigated. The results indicated that the acidic 3-MPA strategy effectively altered the ESM chemical composition, thereby facilitating SEPs extraction. The SEPs from conventional and organic eggs have different protein profiles but with partial overlapping. SEPs from both sources showed similar desirable biosafety profiles and dose-dependent promotion of osteoblastic (ECM) component synthesis, suggesting that different egg sources may contribute to consistent core biological functions of protein products, they may also introduce different functional priorities.

The role of exercise in promoting lymphangiogenesis and extracellular matrix synthesis in lymphedema-induced tissue injury.

Secondary lymphedema is a progressive condition caused by lipid- and protein-rich interstitial fluid accumulation resulting from compromised lymphatic function. It commonly occurs in cancer patients following surgical lymph node ablation and radiation treatment. This study aims to elucidate the effects of exercise on the myokine interleukin (IL)-6 and the molecular changes involved in lymphangiogenesis and extracellular matrix (ECM) synthesis using a lymphedema mouse model. We induced lymphedema in male ICR mice by excising the inguinal, popliteal, and iliac lymph nodes and occluding the femoral lymphatic vessel in the right hind leg. We then conducted a time course analysis of swelling and targeted gene expression analysis of the affected leg tissue. We began the mice on involuntary wheel running exercise 2 days post-surgery. Over the subsequent 2 weeks, the swelling initially increased and then gradually declined. In contrast, the genes associated with lymphangiogenesis and ECM synthesis showed progressive upregulation, even after the swelling had subsided. Exercise reduced limb swelling and increased the genetic expression of IL-6 and key lymphangiogenesis markers, including Prox1, VEGF-C, VEGFR-3, and LYVE-1, in the affected limb. Exercise also increased the expression of FABP4 and αSMA, which are markers of active adipocytes and fibroblasts. Our results suggest that exercise reduces lymphedema by promoting lymphangiogenesis and ECM synthesis, facilitating recovery. The insights obtained into the molecular changes underpinning exercise-induced improvements in lymphedema may contribute to the development of targeted therapeutic strategies.

Biological and Cellular Effects of Percutaneous Electrolysis: A Systematic Review.

Background: Percutaneous electrolysis is an invasive physical therapy technique that is receiving attention. The objective of this article is to evaluate the biological and cellular effects of percutaneous electrolysis and its influence on tissue healing processes. Methods. The search strategy performed in PubMed, Cochrane Library, and Web of Sciences databases resulted in a total of 25 studies. Once inclusion and exclusion criteria were applied, seven studies were finally included in this systematic review. The biological effects of percutaneous electrolysis were evaluated and grouped into pro-inflammatory and anti-inflammatory effects, cell death, and extracellular matrix and tissue remodeling effects. Results. Percutaneous electrolysis generates a significant pro-inflammatory increase in the chronic tendon condition of IL1β-6-18-1α-1rn, NLRP3, and M1 polymorphonuclear cells and increased expression of COX2, TNFα, Cxcl10, and TGFβ1 during the first 7 days. This inflammation is regulated as of day 13. A significant increase in cell death markers, such as LDH, Yo-Pro, cytochrome C, and Smac/Diablo markers, was observed during the first 7 days. Finally, a significant increase in markers Mmp9, VEGF, VEGFR, PPAR-γ/tubulin, and COL-I was observed in the extracellular matrix and tissue remodeling, and a decrease in COL-III was observed during the first 7 days. In the acute inflammatory injury condition, an increase in anti-inflammatory markers, such as IL-10-13, CCL1, and IkB, and a significant decrease in pro-inflammatory cytokines, such as IL-6-1β, CCL3-4-5, CCR5-8, NFkB, and TNFα, were observed during the first 7 days. Finally, a significant increase in VEGF, VEGFR, and PPAR-γ/tubulin markers in the extracellular matrix and tissue remodeling was observed for this condition during the first 7 days. Conclusions. Percutaneous electrolysis generates a controlled local pro-inflammatory effect in chronic conditions and regulates inflammation in inflammatory injuries (during the first 7 days). Electrolysis has short-term effects (0-7 days post) of cell death and controlled extracellular matrix destruction. Additionally, it facilitates subsequent healing by improving extracellular matrix synthesis starting from 7 days after application.

Matrix Metalloproteinase-9 as a Predictor of Healing in Diabetic Foot Ulcers.

Background Wound healing in diabetic foot ulcers (DFUs) is hindered by several physiological and biochemical abnormalities, including prolonged inflammation, an imbalance in extracellular matrix (ECM) synthesis and degradation, insufficient neovascularization, and reduced macrophage activity. In DFUs, excessive and uncontrolled matrix metalloproteinases (MMPs) degrade the ECM and impede wound healing. Matrix metalloproteinase-9 (MMP-9) concentration plays a key role in inflammation and ECM degradation. This study explores the relationship between wound type in DFUs and MMP-9 levels, hypothesizing that a high MMP-9 environment may indicate inflammation and impaired wound healing. Materials and methods Forty individuals with type 2 diabetes and foot ulcers were recruited for the study. The participants were divided into two groups: nonhealing and healing, with 20 patients in each group. Biopsy samples were homogenized, and MMP-9 activity was measured using an ELISA. Results The MMP-9 concentration was significantly higher in nonhealing ulcers compared to healing ulcers. Receiver operating characteristic analysis revealed that MMP-9 measurement was the most accurate predictor of wound healing, with an area under the curve value of 0.945 and high sensitivity and specificity. Although there was a weak correlation between MMP-9 concentration and glycosylated hemoglobin, it was not statistically significant. Conclusions MMP-9 expression serves as a marker of poor wound healing. MMP-9 levels in the wound at the time of presentation may predict the healing trajectory and help tailor a specific treatment plan for each DFU patient.

Evaluation of Nutritional Supplements on Periodontal Fibroblast in Systemic Disease Conditions: An In Vitro Study

ABSTRACT Background: Periodontal health is influenced by various systemic factors, including nutritional status. Nutritional supplements have been proposed to improve periodontal health, particularly in individuals with systemic diseases. Materials and Methods: This in vitro interventional study aimed to evaluate the effects of nutritional supplements on periodontal health in systemic disease conditions. Human gingival fibroblast cells were cultured under conditions mimicking systemic diseases such as diabetes mellitus and cardiovascular disease. The cells were treated with different nutritional supplements commonly used in periodontal therapy, including vitamin C, vitamin D, omega-3 fatty acids, and probiotics. The effects of these supplements on cell viability, inflammatory response, and extracellular matrix production were assessed using various assays and molecular techniques. Results: Treatment with nutritional supplements led to improvements in cell viability, reduction in inflammatory cytokine expression, and enhanced extracellular matrix synthesis in gingival fibroblast cells under systemic disease conditions. Specifically, vitamin C and omega-3 fatty acids demonstrated significant protective effects against inflammation-induced cell damage, while probiotics promoted a balanced immune response. Conclusion: Nutritional supplements, including vitamin C, vitamin D, omega-3 fatty acids, and probiotics, exhibit promising effects on periodontal health in systemic disease conditions. These supplements may serve as adjunctive therapeutic options for managing periodontal disease in individuals with systemic comorbidities.

Computational analysis of flow and transport suggests reduced oxygen levels within intracranial aneurysms, especially in individuals with sickle-cell disease.

Sickle cell disease (SCD) is a genetic condition characterized by an abundance of sickle hemoglobin in red blood cells. SCD patients are more prone to intracranial aneurysms (ICA) compared to the general population, with distinctive features such as multiple intracranial aneurysms: 66% of SCD patients with ICAs have multiples ICAs, compared to 20% in non-sickle patients. The exact mechanism behind these associations is not fully understood, but there is a hypothesized link between hypoxia and impaired synthesis of extracellular matrix, which may weaken the vessel walls, favoring aneurysm formation and rupture. SCD patients experience reduced blood oxygen levels, potentially exacerbating hypoxia in ICAs, and potentially contributing to aneurysm development and early onset in these patients. In this work, we performed a series of computational studies (Fluent) using idealized geometries to investigate the key differences in the oxygen transport and blood flow dynamics inside an aneurysm formation for sickle and non-sickle cases. We found that using SCD parameters resulted in a 14% to 68% reduction in blood flow and a 37% to 70% reduction in oxygen availability within the aneurysm, depending on the vessel curvature and the aneurysm throat diameter, due to factors including oxygen-dependent viscosity and alteration in the oxygen transport. The results indicate that depending on geometry and flow characteristics, some degree of hypoxia maybe present in aneurysm bulb and would be more severe in SCD patients. This study hopes to bring into attention the potential presence of hypoxic environment in the aneurysm bulb.

Fibrosis mechanisms in systemic sclerosis and new potential therapies.

Systemic sclerosis is a rare rheumatic disease characterized by immune cell activation, tissue fibrosis, and endothelial dysfunction. Extracellular matrix synthesis disorder causes widespread fibrosis, primarily in skin and internal organs. Various factors such as TGFβ, VEGF, Galectin-3, and signaling pathways like Wnt/β-catenin are involved in pathophysiological processes. Treatment lacks a unified approach but combines diverse modalities tailored to disease subtype and progression. Current therapeutic strategies include biologics, JAK inhibitors, and IL-6 pathway modulators. Monoclonal antibodies and hypomethylating agents demonstrate potential in fibrosis inhibition. This review focuses on emerging therapeutic evidence regarding drugs targeting collagen, cytokines, and cell surface molecules in systemic sclerosis, aiming to provide insight into potential innovative treatment strategies.

Guilu Erxian glue reduces endoplasmic reticulum stress-mediated apoptosis and restores the balance of extracellular matrix synthesis and degradation in chondrocytes by inhibiting the ATF6/GRP78/CHOP signaling pathway

Knee Osteoarthritis (KOA) is characterized by phenotypic alterations, apoptosis, and the breakdown of the extracellular matrix (ECM) in the superficial articular cartilage cells. The inflammatory response activates the Endoplasmic Reticulum Stress (ERS) signaling pathway, which plays a critical role in the pathophysiology and progression of KOA. Chondrocytes stimulated by thapsigargin(TG)exhibit heightened ERS and significantly increase the expression of ERS-associated proteins. Key mediators of ERS-induced apoptosis include X-box-binding protein 1(XBP1), elevated levels of the protein transport protein Sec61 subunit (SEC61), and C/EBP homologous protein (CHOP).While the precise mechanism of action of Guilu Erxian Glue (GEG), a medication commonly used in the clinical treatment of KOA, remains to be fully elucidated, our research has shown that GEG mitigates the imbalance between ECM synthesis and degradation, as well as chondrocyte apoptosis resulting from ERS. This effect is likely achieved through the suppression of the Activating Transcription Factor 6 (ATF6)/Glucose-Regulatory Protein 78 (GRP78)/CHOP signaling pathway.In summary,our research results indicate that GEG can activate the ATF6/GRP78/CHOP signaling pathway to restore endoplasmic reticulum (ER) homeostasis in chondrocytes, thereby reducing chondrocyte apoptosis and ultimately promoting the balance between ECM synthesis and degradation.

Research progress on mechanisms and pharmacokinetics of ligustilide in treatment of locomotor system diseases

Ligustilide, a phthalide compound extracted from Umbelliferae plants such as Angelica sinensis and Ligusticum chuanxiong, has been proven to possess various pharmacological activities, such as anti-inflammatory, anti-tumor, anti-atherosclerosis, anti-ischemic stroke injury, and anti-Alzheimer's disease properties. In recent years, it has shown great potential, particularly in the treatment of locomotor system diseases. Studies have shown that ligustilide has significant therapeutic effects on various locomotor system diseases, including osteoporosis, osteoarthritis, femoral head necrosis, osteosarcoma, and muscle aging and injury. Its mechanisms of action include enhancing the differentiation ability of osteoblasts(OBs), inhibiting the formation ability of osteoclasts(OCs), downregulating inflammatory factors, promoting the synthesis of extracellular matrix(ECM), improving local blood supply to the femoral head, balancing lipid metabolism, inhibiting the proliferation and migration of osteosarcoma cells, inducing cell cycle arrest, enhancing glucose utilization in skeletal muscle, and regulating autophagy and apoptosis. However, its clinical application is severely limited by drawbacks such as structural instability, poor water solubility, and low bioavailability. Currently, formulation techniques such as dripping pills, micropills, inclusion complexes, and liposomes are being used to improve its stability and water solubility, thereby enhancing its therapeutic efficacy. This article summarized the effects, mechanisms of action, and pharmacokinetics of ligustilide monomers and preparations in the treatment of locomotor system diseases in China and abroad in recent years, aiming to provide reference and guidance for further development and application of ligustilide in this field.

518 Long noncoding RNA SNHG26 promotes keloid progression by regulating the inflammation and extracellular matrix synthesis of fibroblasts

518 Long noncoding RNA SNHG26 promotes keloid progression by regulating the inflammation and extracellular matrix synthesis of fibroblasts

Sulfated galactans ameliorate the cellular senescence in dermal fibroblast cells

Replicative senescence of dermal fibroblast is the primary mechanism of intrinsic skin aging. Recent research has focused on the different properties of sulfated galactans (SG) derived from the red seaweed Gracilaria fisheri. Therefore, we aimed to investigate the potential impact of SG on anti-aging skin. This study used a validated replicative senescent human dermal fibroblast (HDF) model. We observed that replicative senescent HDF cells exhibited remarkable changes in cell morphology, decreased cell proliferation, retarded migrating activity, and reduced extracellular matrix (ECM) production. Additionally, the replicative senescent HDF cells exhibited increased expression of cell cycle inhibitors p16 and p21. Our results demonstrated that SG is safe and effective in reversing these morphological and molecular alterations in senescent HDF cells. SG mediated enhanced ECM synthesis, including collagen, elastin, and hyaluronic acid (HA), and promoted cell migration by upregulating TGF-β1 and TLP gene expression. SG also reduced the expression of ECM breakdown enzymes MMP-1, MMP-2, MMP-3, and MMP-9 while increasing MMP inhibitors TIMP-1 and TIMP-2. These results indicate that SG effectively restores fibroblast function, contributing to decelerating the aging processes, supporting its potential as a therapeutic agent for skin rejuvenation and anti-aging treatments.

RICTOR-mediated activation of AKT/mTOR signaling and autophagy inhibition promote osteoarthritis

The most common joint disease in the elderly is osteoarthritis (OA), which is characterized by synovitis, cartilage degeneration, and osteophytes, for which there are currently no effective therapies. Chondrocytes, responsible for extracellular matrix (ECM) synthesis and degradation, undergo changes in OA, leading to ECM disruption and disease progression. There is no clear role for the Mechanistic target of rapamycin complex 2 (mTORC2) in OA, but it is known to regulate cellular functions, such as proliferation, metabolism, motility, and apoptosis. The purpose of this study was to determine the molecular mechanism by which Rapamycin-insensitive companion of mTOR (RICTOR), a component of mTORC2, contributes to OA progression. The results demonstrate that IL-1β induces high expression of RICTOR in chondrocytes, promoting downregulation of collagen II expression and impairing autophagy. Silencing RICTOR reverses IL-1β-induced downregulating of collagen II expression and mitochondrial dysfunction. RICTOR inhibits chondrocyte autophagy by inhibiting autophagosome formation and preventing autophagosome-lysosome fusion. Additionally, RICTOR promotes oxidative stress in chondrocytes, leading to disruption of normal mitochondrial structure and disturbance of the articular cartilage microenvironment. This study reveals the potential of RICTOR to treat OA. Specifically, blocking mTORC2 might be an effective treatment strategy.

PLGA/BK microspheres targeting the bradykinin signaling pathway as a therapeutic strategy to delay intervertebral disc degeneration

Intervertebral disc degeneration(IVDD) is a common spinal condition with limited effective treatments available. This study aims to investigate the impact of poly(lactic-co-glycolic acid)/Bradykinin (PLGA/BK) microspheres on IVDD and its underlying mechanisms. We collected nucleus pulposus samples from both healthy and degenerated human intervertebral disks and conducted immunohistochemical analyses, revealing reduced BK expression in degenerated tissues. Subsequently, we used BK to treat nucleus pulposus cells and conducted Bulk RNA sequencing (RNA-seq), identifying BK’s involvement in cellular senescence, extracellular matrix metabolism, and the PI3K signaling pathway. Further experiments using tert-butyl hydroperoxide (TBHP)-induced cell senescence showed that BK treatment reduced senescence, enhanced extracellular matrix synthesis, and inhibited degradation, along with activation of the PI3K pathway. These effects were mediated through B2R (BK receptor 2) and the downstream PI3K pathway. Following this, we developed sustained-release BK microspheres with an optimized manufacturing process. In vitro co-culture experiments showed no observable toxicity. We established an IVDD model in rat tail vertebrae through fine needle puncture, administering local injections of BK sustained-release microspheres. Using various experimental methods, including X-ray, MRI, histopathology, and immunohistochemistry, we found that these microspheres could slow the progression of IVDD. This study highlights the potential of injectable PLGA/BK microspheres to regulate cellular senescence and extracellular matrix metabolism via the B2R and PI3K pathways, ultimately delaying IVDD.

Integrative transcriptome analysis reveals Serpine2 promotes glomerular mesangial cell proliferation and extracellular matrix accumulation via activating ERK1/2 signalling pathway in diabetic nephropathy.

Diabetic nephropathy (DN) is one of the main causes of end-stage renal disease (ESRD), but its mechanism has not been clearly studied. We utilized integrative transcriptome analysis to explore the pathogenesis of DN. We conducted an analysis by combining bulk dataset and single-cell transcriptome dataset. Through this approach, we identified that Serpine2 may regulate the 'collagen-containing extracellular matrix' pathway involved in DN. Subsequently, we established DN animal and cell models using db/db mice and mesangial cells (MCs) to validate the role of Serpine2 in DN. In the animal model, we detected the expression level of Serpine2 in DN using western blotting (WB) and immunofluorescence (IF) assays. To further clarify the molecular mechanism of Serpine2 in DN, we knocked down Serpine2 and observed its effects on MCs proliferation and extracellular matrix (ECM) accumulation. Our single-cell analysis of DN models highlighted a pivotal role for MCs in the disease's initiation. Next, through Cytoscape analysis of differentially expressed genes (DEGs) in MCs, we identified the following 10 hub genes: Acta2, Angpt2, Ccn1, Col4a1, Col4a2, Col8a1, Kdr, Thbs1, Tpm4 and Serpine2. Subsequently, we identified that Serpine2 and Kdr were also significantly DEGs in the bulk analysis of glomeruli. Additionally, our integrated gene set enrichment analysis of bulk dataset and single-cell RNA dataset revealed that the 'collagen-containing extracellular matrix' was a key pathway in DN progression. Serpine2 was one of the crucial genes involved in regulating this pathway. Therefore, we speculated that the regulation of the 'collagen-containing extracellular matrix' pathway by Serpine2 was an important mechanism. Importantly, WB and IF staining confirmed that Serpine2 expression was upregulated in the MCs of diabetic mice. Knockdown of Serpine2 in cultured MCs alleviated high-glucose-induced excessive MCs proliferation and ECM accumulation. Finally, we found that ERK agonist Ro 67-7476 eliminated the effect of Serpine2 siRNA. In summary, Serpine2 regulates MCs proliferation and ECM synthesis through activation of the ERK1/2 pathway, which is an important pathogenesis mechanism of DN. These findings offer fresh perspectives on the mechanisms of glomerulosclerosis in DN pathogenesis and may provide new targets for treating DN.