Search Results (805)

Cell-mediated extracellular matrix (ECM) self-assembly provides a biologically relevant approach for developing near-physiological tissue-engineered constructs by utilizing stromal cells to secrete and assemble ECM components in the presence of ascorbic acid. Despite its unique advantages, this method often results in scaffolds with limited mechanical properties, depending on the cell type. This research aimed to enhance the mechanical properties of these constructs by culturing cells derived from various sources, including skin, bladder, urethra, vagina, and adipose tissue, on electrospun scaffolds composed of polycaprolactone and collagen (PCLCOL). The hybrid scaffolds were evaluated using various in vitro assays to assess their structural and functional properties. Results showed that different stromal cells could deposit ECM on the PCLCOL with distinct composition compared to the ECM that was self-assembled on tissue culture plates (TCP). Additionally, cells cultured on PCLCOL exhibited a different growth factor secretion profile compared to those on TCP. Mechanical testing demonstrated that the hybrid scaffolds exhibited high mechanical properties and superior manipulability. These findings suggest that PCLCOL could be a promising platform for developing biomimetic scaffolds that combine enhanced mechanical strength with integrated biological cues for tissue repair. Full article

β-Hydroxy-β-methylbutyrate (HMB), a natural metabolite derived from the essential amino acid leucine, is primarily recognised for its anabolic and anti-catabolic effects on skeletal muscle tissue. Recent studies indicate that HMB may also play a role in influencing the structural organisation of extracellular matrix (ECM) components, particularly collagen, which is crucial for maintaining the mechanical integrity of connective tissues. In this investigation, bovine type I collagen was polymerised in the presence of two concentrations of HMB (0.025 M and 0.25 M) to explore its potential function as a molecular modulator of fibrillogenesis. The morphology of the resulting collagen fibres and their molecular architecture were examined using atomic force microscopy (AFM) and Fourier-transform infrared (FTIR) spectroscopy. The findings demonstrated that lower levels of HMB facilitated the formation of more regular and well-organised fibrillar structures, exhibiting increased D-band periodicity and enhanced stabilisation of the native collagen triple helix, as indicated by Amide I and III band profiles. Conversely, higher concentrations of HMB led to significant disruption of fibril morphology and alterations in secondary structure, suggesting that HMB interferes with the self-assembly of collagen monomers. These structural changes are consistent with a non-covalent influence on interchain interactions and fibril organisation, to which hydrogen bonding and short-range electrostatics may contribute. Collectively, the results highlight the potential of HMB as a small-molecule regulator for soft-tissue matrix engineering, extending its consideration beyond metabolic supplementation towards controllable, materials-oriented modulation of ECM structure. Full article

Pancreatic ductal adenocarcinoma (PDAC) remains highly lethal due to late diagnosis, high malignancy, and profound resistance to therapy. Traditional two-dimensional (2D) cell cultures fail to recapitulate the complex tumor microenvironment (TME), especially the fibrotic stroma, which is crucial for the progression of PDAC and drug response. In vitro three-dimensional (3D) models, which provide more physiologically relevant features such as tight cell–cell and cell-extracellular matrix (ECM) interactions, as well as 3D architecture, have been regarded as highly promising models in PDAC research. This review summarizes some representative in vitro PDAC models, including 3D spheroids, tumor-on-a-chip, bioprinted constructs, and patient-derived organoids (PDOs), particularly focused on the advances in bioengineering strategies for the integration of the key stomal components for microenvironment recapitulation and their applications. Additionally, we discuss the current challenges facing 3D models and propose potential strategies for constructing in vitro models that more accurately simulate the pathophysiology of the fibrotic stroma, aiming for their application in clinical settings. Full article

Background: Type 2 diabetes (T2D) is associated with reduced cardiorespiratory fitness (CRF), a critical predictor of cardiovascular disease and all-cause mortality. CRF relies upon the coordinated action of multiple systems including the skeletal muscle where the mitochondria metabolize oxygen and substrates to sustain ATP production. Yet, previous studies have shown that impairments in muscle bioenergetics in T2D are not solely due to mitochondrial deficits. This finding indicates that factors outside the mitochondria, particularly within the local tissue microenvironment, may contribute to reduced CRF. One such factor is the extracellular matrix (ECM), which plays structural and regulatory roles in metabolic processes. Despite its potential regulatory role, the contribution of ECM remodeling to metabolic impairment in T2D remains poorly understood. We hypothesize that pathological remodeling of the skeletal muscle ECM in overweight individuals with and without T2D impairs bioenergetics and insulin sensitivity, and that exercise may help to ameliorate these effects. Methods: Participants with T2D (n = 21) and overweight controls (n = 24) completed a 10-day single-leg exercise training (SLET) intervention. Muscle samples obtained before and after the intervention were analyzed for ECM components, including collagen, elastin, hyaluronic acid, dystrophin, and proteoglycans, using second harmonic generation imaging and immunohistochemistry. Results: Positive correlations were observed with elastin content and both glucose infusion rate (p = 0.0010) and CRF (0.0363). The collagen area was elevated in participants with T2D at baseline (p = 0.0443) and showed a trend toward reduction following a 10-day SLET (p = 0.0867). Collagen mass remained unchanged, suggesting differences in density. Dystrophin levels were increased with SLET (p = 0.0256). Conclusions: These findings identify that structural proteins contribute to aerobic capacity and identify elastin as an ECM component linked to insulin sensitivity and CRF. Full article

Collagens make up the main components of the extracellular matrix (ECM), and, in cancer, are often aberrantly secreted by both tumor cells and stromal cells in the tumor microenvironment (TME). Collagen prolyl 4-hydroxylase (C-P4H), an enzyme that hydroxylates proline into 4-hydroxyproline at the Y position of the collagen -X-Y-Gly- triplet motif, is essential for the stability of the mature collagen trimer and collagen secretion. In this review, we summarize the research on the structure and function of C-P4H, the regulation of C-P4H enzyme activity, and the role of overexpression of its α-subunit, P4HA1, in promoting cancer progression as well as its potential as a prognostic marker and therapeutic target. Overexpression of P4HA1 is displayed in almost all solid cancers, including breast, colorectal, and lung cancer, and is associated with cancer progression, worse response to therapy, and poorer patient survival. Characterization of P4HA1 overexpression has demonstrated links to key hallmarks of cancer, not only in the canonical collagen deposition role, but also in non-canonical functions, such as cell stemness, hypoxic response, glucose metabolism, angiogenesis, and modulation of tumor-infiltrating lymphocytes (TILs) in the tumor microenvironment. P4HA1 is thus an attractive target for developing novel targeted therapies to improve treatment response in many cancer types. Full article

The adult heart has a limited ability to regenerate, which is partly due to the structural and metabolic specialization that cardiomyocytes (CMs) acquire during postnatal maturation. In this review, we explore how cytoskeletal remodeling, metabolic reprogramming, and interactions with the extracellular matrix (ECM) regulate CM maturation, proliferation, and the potential for regeneration. We describe how the assembly of microtubules, actin filaments, and sarcomeric structures is essential for developing contractile function, but also creates structural barriers that prevent cell division. Recent studies show that disassembling these cytoskeletal components, along with activating signaling pathways such as Hippo-YAP, Wnt, and NRG1/ErbB4, can promote CM dedifferentiation and re-entry into the cell cycle. Metabolic shifts also play a critical role. A return from oxidative phosphorylation to glycolysis also leads to CM dedifferentiation and proliferation. In addition, changes in ECM composition and mechanical signaling affect cytoskeletal dynamics and regenerative capacity. Understanding how these structural, metabolic, and signaling networks work together opens the door to new approaches for restoring heart function after injury. Full article

The understanding of medulloblastoma (MB) progression is limited by the lack of minimally invasive monitoring methods. Extracellular vesicles (EVs) carrying disease-specific signatures are promising for liquid biopsies, but clinical translation is hindered by inconsistent isolation techniques. This study compares small EVs (sEVs) and their proteomes from blood plasma (BP) and cerebrospinal fluid (CSF) in MB. Using ultrafiltration and size exclusion chromatography (UF-SEC), we isolated sEVs from pediatric patient samples. sEV proteins from matched CSF-BP samples from MB patients (MBCSF/MBBP), healthy BP controls (HCBP), and MB cell lines (MBCL) were analyzed by liquid chromatography-tandem mass spectrometry, subjected to Gene Ontology and Cytoscape analyses, and compared to published MB, CSF, and EV datasets. By optimizing UF-SEC for small volumes, we found that CSF-sEVs are smaller and elute in later SEC fractions. Proteins linked to the extracellular matrix (ECM) were enriched in MBCSF and MBCL, while integrin binding showed inconsistent patterns between MBCSF and MBBP. MBBP and HCBP showed no significant differences. Fourteen proteins from MB datasets were identified in our analysis and primarily enriched in CSF. These findings support CSF-sEVs as more informative than BP-sEVs for MB diagnosis and monitoring, emphasize the need for fluid-specific sEV isolation, and suggest that ECM components and integrins may mediate MB progression. Full article

Background/Objectives: The most commonly diagnosed group of rheumatic diseases in children is juvenile idiopathic arthritis. It is characterized by a chronic inflammatory process that leads to the degradation of the bone and joint system and increased secretion of pro-inflammatory cytokines such as TNF-α, IL-1, and IL-6. These cytokines contribute to the dysregulation of adipocytokine metabolism, including adiponectin and leptin, as well as extracellular matrix components, such as tenascin C. While it is known that children with JIA exhibit TNF-α-stimulated degradation of most ECM cartilage components, the effect of TNF-α antagonists, such as etanercept, on these processes has not yet been evaluated. Therefore, the aim of our study was to assess the dynamics of changes in tenascin C, adiponectin, and leptin levels in the blood of children with JIA, both before and during therapy. Methods: The study material consisted of blood samples collected from 66 children of both sexes, including 40 girls and 26 boys diagnosed with juvenile idiopathic arthritis and treated with etanercept, as well as from 40 healthy children (22 girls and 18 boys). The quantitative assessment of adiponectin, leptin, and tenascin C levels was performed using commercial ELISA tests. Results: The conducted study revealed that untreated children with JIA exhibit altered plasma levels of all examined parameters—adiponectin, leptin, and tenascin C. Specifically, there was an increase in adiponectin concentration and a decrease in leptin as well as TNC levels compared to healthy children. The results demonstrated the beneficial effects of the TNF-α antagonist, i.e., etanercept, which not only improved the clinical condition of children with JIA but also positively influenced the metabolism of both adipokines and tenascin C. Conclusions: The obtained results suggest the potential use of adiponectin, leptin, and tenascin C as biochemical markers of the effectiveness of etanercept therapy in inhibiting the progression of degenerative joint changes in children with JIA treated with TNF-α inhibitors. Full article

Fibrosis is a pathological process characterized by the excessive accumulation of extracellular matrix (ECM), particularly collagen, leading to tissue scarring, architectural distortion, and organ dysfunction. While fibrosis is a physiological component of wound healing, its persistence and dysregulation can drive chronic tissue damage and organ dysfunction. In autoimmune diseases, fibrosis arises from prolonged inflammation and immune system dysregulation, creating a vicious cycle that exacerbates tissue injury and promotes disease progression. This review provides a comprehensive overview of the fibrotic processes across a range of immune-mediated and autoimmune conditions, including systemic sclerosis (SSc), morphea, autoimmune hepatitis (AIH), systemic lupus erythematosus (SLE), Sjögren’s syndrome (SS), inflammatory bowel disease (IBD), and rheumatoid arthritis (RA), Finally, we discuss current and emerging antifibrotic strategies aimed at interrupting pathological ECM remodeling and restoring tissue homeostasis. Full article

Skeletal muscles are essential for movement and support but are vulnerable to injury. Muscle regeneration relies on the extracellular matrix (ECM), which regulates key cellular processes. Transforming growth factor β-induced (TGFBI), an ECM component involved in cell adhesion, migration, and tissue development, has not been investigated in skeletal muscle regeneration. Here, we examined the role of TGFBI using Tgfbi knockout (KO) mice and C2C12 myoblasts. In vitro, C2C12 cells were treated with recombinant TGFBI following snake venom (SV)-induced injury, and myogenic differentiation and fusion were evaluated by quantitative real-time PCR (qRT-PCR) and Western blotting. In vivo, acute muscle injury was induced by SV injection into the tibialis anterior muscles of 12-week-old wild-type and Tgfbi KO mice, with regeneration assessed by histology and qRT-PCR. TGFBI was absent in uninjured muscle and C2C12 cells but was upregulated after injury. Recombinant TGFBI enhanced myogenic differentiation and restored SV-induced downregulation of myogenic and fusion markers. Although phenotypically normal under physiological conditions, Tgfbi KO mice exhibited impaired regeneration, characterized by persistent immature myofibers, elevated inflammatory cytokines, reduced myogenic marker expression, and increased fibrosis. These findings reveal TGFBI as a key regulator of skeletal muscle repair and a potential therapeutic target for muscle-related disorders. Full article

Organoids, self-organizing, three-dimensional (3D) multicellular structures derived from tissues or stem cells, offer physiologically relevant models for studying human development and disease. Compared to conventional two-dimensional (2D) cell cultures and animal models, organoids more accurately recapitulate the architecture and function of human organs. Among the critical microenvironmental cues influencing organoid behavior, hypoxia and multilineage communication are particularly important for guiding cell fate, tissue organization, and pathological modeling. Hypoxia, primarily regulated by hypoxia-inducible factors (HIFs), modulates cellular proliferation, differentiation, metabolism, and gene expression, making it a key component in disease modeling. Similarly, multilineage communication, facilitated by intercellular interactions and extracellular matrix (ECM) remodeling, enhances organoid complexity and immunological relevance. This review explores the dynamic interplay between hypoxia and multilineage signaling in 3D organoid-based disease models, emphasizing recent advances in engineering hypoxic niches and co-culture systems to improve preclinical research fidelity. We also discuss their translational implications for drug screening, regenerative medicine, and precision therapies, while highlighting current challenges and future opportunities. By integrating biophysical, biochemical, and computational approaches, next-generation organoid models may be further optimized for translational research and therapeutic innovation. Full article

Head and neck squamous cell carcinomas (HNSCCs) represent a diverse group of malignancies, both clinically and biologically, with human papillomavirus (HPV) infection playing a significant role. HPV-positive tumours generally tend to have a better prognosis and are driven by oncoproteins E6 and E7. In contrast, HPV-negative tumours typically have a worse prognosis and are often linked to mutations in tumour suppressor genes. HNSCCs exist within a complex environment known as the tumour microenvironment (TME). The TME includes tumour cells, cancer stem cells (CSCs), cancer-associated fibroblasts (CAFs), immune cells, extracellular matrix (ECM), blood vessels, and various signalling molecules. These components support tumour progression, invasion, metastasis, and resistance to treatment. Intercellular signalling within the TME—mediated by cytokines such as IL-6, TGF-b, and galectins—further promotes tumour growth and systemic effects like cachexia. Notably, the TME shares features with granulation tissue during wound healing, supporting the concept of cancer as a chronic, non-resolving wound. Effective therapy must target not only tumour cells but also the dynamic TME. Full article

Mesenchymal stromal/stem cells (MSCs) are known to secrete a wide range of pleiotropic molecules promoting tissue repair and regeneration. Recent advances in cell sheet technology have demonstrated significant improvements in the regenerative capacity of MSCs within the sheet, retaining appropriate microenvironmental cues, and have suggested an instructing role of extracellular matrix (ECM). We previously found that the secretome of MSCs cultured on a decellularized MSC-derived ECM (dECM) was significantly enriched in dozens of cytokines, chemokines and growth factors compared to the secretome of MSCs grown on standard plastic dishes. The enriched secretome has been shown to have enhanced chemotactic and angiogenic properties, stimulate C2C12 myoblast proliferation and promote skeletal muscle regeneration in a murine in vivo model. Here, we report novel findings about dECM-induced changes in the miRNA profile of MSCs. We performed miRNA-seq and found 17 differentially expressed miRNAs in endometrial MSCs (MESCs) with miR-146a-5p being the most upregulated. Additionally, we investigated miR-146a-5p expression in MSCs of various origins after exposure to dECM, and found a correlation between miR-146a-5p upregulation and the general dECM-induced paracrine response. Furthermore, we demonstrated that miR-146a-5p mimics, transfected into C2C12 myoblasts, promoted their proliferation, suggesting a role for miR-146a-5p in myotropic effects mediated by the enriched secretome. These findings provide new insights into how ECM as a component of the MSC niche influences the secretory phenotype and modulates therapeutic properties of MSCs. Full article

(1) Background: Supernumerary teeth are developmental anomalies, and their pulp tissue may harbor unique cellular and molecular features. However, the biology of this rare tissue remains poorly understood. This study aimed to characterize the cellular diversity and regenerative potential of supernumerary pulp at single-nucleus resolution. (2) Methods: Human supernumerary tooth pulp samples were analyzed using single-nucleus RNA sequencing. Gene expression profiles were processed and reduced to their main patterns of variation using principal component analysis (PCA), supported by clustering, pathway analysis, and lineage-specific scoring. (3) Results: The analysis suggested two dominant biological programs: a vascular–immune/stress axis and an extracellular matrix (ECM)/contractile remodeling axis. Vascular lineages were closely linked to immune and stress responses, while mesenchymal and perivascular populations were enriched in ECM-related pathways. Neural and glial contributions were relatively minor. (4) Conclusions: These findings suggest that supernumerary pulp appears to preserve key regenerative features similar to normal pulp, but with potential reinforcement of vascular–immune coupling and ECM remodeling. This work represents the first single-nucleus transcriptomic reference for supernumerary pulp, offering a foundation for future studies on dental pulp regeneration. Full article

Snail slime (SS) is a natural secretion rich in bioactive components such as glycoproteins, hyaluronic acid, glycolic acid (GA), and antimicrobial peptides. GA, a key component of SS, is known for its exfoliative properties. This study investigates SS’s effects on keratinocytes (HaCaT) and endothelial cells (ECs), comparing its properties to those of GA. HaCaT cell viability and cytotoxicity, ROS release, and inflammation-related signaling (PI3K/Akt/NF-κB and COX-2 gene expression) were assessed. Extracellular matrix (ECM) remodeling was evaluated by gene expression of MMPs. In ECs, a preliminary evaluation of SS’s effect was conducted in terms of cell viability and migration. Results demonstrated that SS is well tolerated by keratinocytes whereas GA exhibits cytotoxicity, suggesting that SS’s natural composition mitigates GA’s adverse effects. SS induced a controlled, brief inflammatory response, via the PI3K/Akt/NF-κB pathway, unlike GA, responsible for stronger and sustained pro-inflammatory events. Additionally, SS, through the upregulation of MMPs, contributes to ECM remodeling. In ECs, SS preserves viability and also enhances migration, thus supporting wound healing. These findings highlight SS’s ability to balance pro-inflammatory events, making it a promising candidate for advanced dermatological applications, underscoring SS’s potential in modulating key cellular signaling pathways, and supporting its future therapeutic prospects in wound healing. Full article