Search Results (7,329)

Secreted protein acidic rich in cysteine (SPARC), one of the extracellular matrix proteins, is highly induced during inflammation. We investigated the pathophysiological regulation and role of SPARC in vascular inflammation in a rat model of hypertension created using deoxycorticosterone acetate (DOCA, 40 mg/kg/week, s.c.) and salt (1% in drinking water). DOCA–salt administration time-dependently increased systolic blood pressure during the 3-week treatment period, blunted endothelium-dependent vasodilation, and increased monocyte chemoattractant protein-1 (MCP-1) and lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) expression in the aorta. SPARC expression transiently increased until week 2 in the DOCA–salt rat aorta. Interestingly, aortic SPARC levels correlated with blood pressure and the levels of MCP-1 and LOX-1 during 0–2 weeks. The AT₁ receptor blocker, losartan, suppressed the overexpression of SPARC, and in vitro treatment with angiotensin II enhanced the production of SPARC in rat aortic endothelial cells. Exposure to recombinant SPARC protein induced overexpression of MCP-1 and LOX-1 mRNA in endothelial cells. Bioactive forms of a disintegrin and metalloproteinase with thrombospondin type 1 motif (ADAMTS1), excessive activation of which contributes to pathological states and overexpression of which is reported to be induced by SPARC, were increased in the DOCA–salt rat aorta. These results suggest that SPARC is induced by the vascular renin–angiotensin system and causes inflammation in the early stages of hypertensive vascular injury, and that activation of ADAMTS1 might be related to the proinflammatory effects of SPARC. Full article

Background/Objectives: Under physiological conditions, vascular smooth muscle cells (VSMCs) are in a quiescent contractile state, but under pathological conditions, such as atherosclerosis, they change their phenotype to synthetic, characterized by increased proliferation, migration, and production of an extracellular matrix. Furthermore, VSMCs can undergo calcification, switching to an osteoblast-like phenotype, contributing to plaque instability. Methods: In this study, we analyzed the phenotypic changes in VSMCs during the transition from a physiological to a pathological state, a key process in the progression of atherosclerosis, using confocal and transmission electron microscopy, real-time PCR, and intracellular calcium quantification. Results: Confocal and transmission electron microscopy revealed a prominent remodeling of the actin cytoskeleton, increasing autophagic vacuoles in synthetic VSMCs and the deposition of calcium microcrystals in calcified cells. Immunofluorescence analysis revealed differential expression of α-SMA (contractile marker) and galectin-3 (synthetic marker), confirming the phenotypic changes. Real-time PCR further validated these changes, showing upregulation of RUNX-2, a marker of osteogenic transition, in calcified VSMCs. Conclusions: This study highlights the dynamic plasticity of VSMCs and their role in atherosclerosis progression. Understanding the characteristics of these phenotypic transitions can help develop targeted therapies to mitigate vascular calcification and plaque instability, potentially countering cardiovascular disease. Full article

Cellular communication network factor 2 (CCN2, also known as CTGF) is a complex protein that regulates numerous cellular functions. This biomolecule exhibits dual functions, depending on the context, and can act as a matricellular protein or as a growth factor. CCN2 is an established marker of fibrosis and a well-known mediator of kidney damage, involved in the regulation of inflammation, extracellular matrix remodeling, cell death, and activation of tubular epithelial cell (TECs) senescence. In response to kidney damage, cellular senescence mechanisms are activated, linked to regeneration failure and progression to fibrosis. Our preclinical studies using a total conditional CCN2 knockout mouse demonstrate that CCN2 plays a significant role in the development of a senescence phenotype after exposure to a nephrotoxic agent. CCN2 induces cell growth arrest in TECs, both in the early phase and in the chronic phase of folic acid nephropathy (FAN), associated with cell-death/necroinflammation and fibrosis, respectively. Renal CCN2 overexpression was found to be linked to excessive collagen accumulation in tubulointerstitial areas, microvascular rarefaction, and a decline in renal function, which were observed three weeks following the initial injury. All these findings were markedly diminished in conditional CCN2 knockout mice. In the FAN model, injured senescent TECs are associated with microvascular rarefaction, and both were modulated by CCN2. In primary cultured endothelial cells, as previously described in TECs, CCN2 directly induced senescence. The findings collectively demonstrate the complexity of CCN2, highlight the pivotal role of cellular senescence as an important mechanism in renal injury, and underscore the critical function of this biomolecule in kidney damage progression. Full article

For organ-on-a-chip (OoC) engineering, the use of biocompatible coatings and materials is not only recommended but essential. Extracellular matrix (ECM) components are commonly used as coatings due to their effects on cell orientation, protein expression, differentiation, and adhesion. Among the most frequently used coatings are collagen, fibronectin, and Matrigel, according to the specific cell type and intended OoC application. Additionally, materials such as polydimethylsiloxane (PDMS), thermoplastics, chitosan, and alginate serve as scaffolding components due to their biomechanical properties and biocompatibility. Here, we discuss some of the most employed coating techniques, including SAMs, dip coating, spin coating, microcontact printing, and 3D bioprinting, each offering advantages and drawbacks. Current challenges comprise enhancing biocompatibility, exploring novel materials, and improving scalability and reproducibility. Full article

Platelet activation processes begin when injury to blood vessels exposes the subendothelial matrix, leading platelets to attach to it, where they become activated and exert their hemostatic function. Excessive platelet aggregation is associated with thrombotic disorders such as arterial thrombosis. To manage such diseases, medications that inhibit thrombosis are continuously sought, despite potential drawbacks that include hemorrhage. This study described the development of a novel peptide-based vaccine that targets the purinergic ADP P2Y₁ receptor (abbreviated EL2Vac) and its pharmacological characterization. Thus, we designed and developed an EL2Vac that targets the ligand-binding domain of the P2Y₁ receptor protein, which is located in its second extracellular loop (EL2). We then evaluated the vaccine’s ability to trigger an immune response (antibody production) in immunized mice, modulate platelet function, its antithrombotic activity, and any effects on hemostasis, by employing a thrombosis model and the tail bleeding time assay. Results showed significant levels of antibody production in mice treated with EL2Vac, in comparison with the random peptide vaccine control (EL2rVac), which persisted at least up to six months post vaccination. Moreover, we observed significant inhibition of the ADP-induced aggregation response in platelets from EL2Vac-treated mice, relative to those from EL2rVac controls. This inhibition was selective for ADP, as other agonists, such as the thromboxane A₂ receptor (TPR) agonist U46619 or high-dose collagen, had no detectable effect on aggregation. As for its capacity to protect against thrombosis, our data showed a significant delay in the occlusion time of the EL2Vac mice when compared with the random peptide control vaccine, which was also observed (at least) six months post vaccination. Interestingly, EL2Vac did not appear to prolong the tail bleeding time, supporting the notion that it is devoid of a bleeding diathesis. As a conclusion, this study documents the design and evaluation of a novel peptide-based vaccine, EL2Vac, which appears to selectively target the P2Y₁ receptor and protect against thrombus formation without impairing hemostasis. Thus, EL2Vac may provide a promising clinical option to treat thromboembolic disorders. Full article

Hypoxia results in a wide range of adaptive physiological responses, including metabolic reprogramming, erythropoiesis, and angiogenesis. The response to hypoxia at the cellular level is mainly regulated by hypoxia-inducible factors (HIFs): HIF1α and HIF2α isoforms. Although structurally similar and overlapping gene targets, both isoforms can exhibit distinct expression patterns and functions in some conditions of hypoxia. The interaction between these isoforms, known as the “HIF switch”, determines their coordinated function under varying oxygen levels and exposure time. In angiogenesis, HIF-1α is rapidly stabilized under acute hypoxia, prompting a metabolic shift from oxidative phosphorylation to glycolysis and initiating angiogenesis by activating endothelial cells and extracellular matrix remodeling. Conversely, HIF-2α regulates cell responses to chronic hypoxia by sustaining genes critical for vascular remodeling and maturation. The current review highlights the different roles and regulatory mechanisms of HIF-1α and HIF-2α isoforms, focusing on their involvement in cell metabolism and the multi-step process of angiogenesis. Tuning the specific targeting of HIF isoforms and finding the right therapeutic window is essential to obtaining the best therapeutic effect in diseases such as cancer and vascular ischemic diseases. Full article

Tumor-Treating Fields (TTFields), a novel therapeutic avenue, is approved for therapy in Glioblastoma multiforme, malignant pleural mesothelioma, and metastatic non-small cell lung cancer (NSCLC). In pancreatic ductal adenocarcinoma (PDAC), several clinical trials are underway to improve outcomes, yet a significant knowledge gap prevails involving the cell-extracellular matrix (ECM) crosstalk. Herein, we hypothesized that treatment with TTFields influence this crosstalk, which is reflected by the dynamic alteration in nanomechanical properties (NMPs) of cells and the ECM in a co-culture system. We employed an ECM gel comprising collagen, fibronectin, and laminin mixed in 100:1:1 stoichiometry to co-culture of Panc1 and AsPC1 individually. This ECM mixture mimics the in vivo tumor microenvironment closely when compared to the individual ECM components studied before. A comprehensive frequency-dependent study revealed the optimal TTFields frequency to be 150 kHz. We also observed that irrespective of the ECM’s presence, TTFields increase cell membrane stiffness and decrease deformation several-folds in both Panc1 and AsPC1 cells at both 48 h and 72 h. Although adhesion for AsPC1 decreased at 48 h, at 72 h it was observed to increase irrespective of ECM’s presence. Moreover, it significantly alters the NMPs of ECM gels when co-cultured with PDAC cell lines. However, AsPC1 cells were observed to be more detrimental to these changes. Lastly, we attribute the stiffness changes in Panc1 cells to the membrane F-actin reorganization in the presence of TTFields. This study paves a path to study complex PDAC TME as well as the effect of various chemotherapeutic agents on such TME with TTFields in the future. Full article

Lizards are distinguished as the only amniotes, and closest relatives of mammals, capable of multilineage epimorphic regeneration. Tail blastemas of green anole lizards (Anolis carolinensis) consist of col3a1⁺ fibroblastic connective tissue cells enclosed in krt5⁺ wound epidermis (WE), both of which are required for regeneration. Blastema and WE formation are known to be closely associated with phagocytic cell populations, including macrophages and osteoclasts. However, it remains unclear what specific phagocytic cell types are required to stimulate regeneration. Here, we explicitly assess the roles of osteoclast activity during blastema and WE formation in regenerating lizard tails. First, probe sequencing was performed at regenerative timepoints on fibroblasts isolated based on col3a1 expression toward establishing pathways involved in stimulating blastema formation and subsequent tail regrowth. Next, treatments with osteoclast inhibitor zoledronic acid (ZA) were used to assess the roles of osteoclast activity in lizard tail regeneration and fibroblast signaling. ZA treatment stunted lizard tail regrowth, suggesting osteoclast activity was required for blastema formation and regeneration. Transcriptomic profiling of fibroblasts isolated from ZA-treated and control lizards linked inhibition of osteoclast activity with limitations in fibroblasts to form pro-regenerative extracellular matrix and support WE formation. These results suggest that crosstalk between osteoclasts and fibroblasts regulates blastema and WE formation during lizard tail regeneration. Full article

Mammalian tissues and cells often orient naturally in specific patterns to function effectively. This cellular alignment is influenced by the chemical nature and topographic features of the extracellular matrix. In implants, a range of different materials have been used in vivo. Of those, tantalum and its alloys are promising materials, especially in orthopedic implant applications. Previous studies have demonstrated that nano- and micro-scale surface features, such as symmetric comb structures, can significantly affect cell behavior and alignment. However, patterning need not be restricted to symmetric geometries, and there remains a gap in knowledge regarding how cells respond to asymmetric comb structures, where the widths of the trenches and lines in the comb differ. This study aims to address this gap by examining how Vero cells (cells derived from an African green monkey) respond when applied to tantalum and tantalum/silicon oxide asymmetric comb structures having fixed trench widths of 1 μm and line widths ranging from 3 μm to 50 μm. We also look at the cell responses on inverted patterns, where the line widths were fixed at 1 μm while trench widths varied. The orientation and morphology of the adherent cells were analyzed using fluorescence confocal microscopy and scanning electron microscopy. Our results indicate that the widths of the trenches and lines are important design parameters influencing cell behavior on asymmetric comb structures. Furthermore, the ability to manipulate cell morphology using these structures decreased when parts of the tantalum lines were replaced with silicon oxide. Full article

Aortic dissection (AD) is a life-threatening vascular condition with limited pharmacological options, and shared risk factors with cardiac disease include hypertension, atherosclerosis, smoking, and dyslipidemia. This study investigated Ferrostatin-1 (Fer-1), a ferroptosis inhibitor, in a BAPN/Ang-II-induced mouse model of AD, revealing significant therapeutic potential. Fer-1 significantly reduced AD incidence and mortality by preserving aortic wall integrity. RNA sequencing identified 922 differentially expressed genes, with 416 upregulated and 506 downregulated. Bioinformatics analysis revealed that Fer-1 modulates key regulators, such as MEF2C and KDM5A, impacting immune responses, oxidative stress, apoptosis, and lipid metabolism. Additionally, Fer-1 alters miRNA expression, with the upregulation of miR-361-5p and downregulation of miR-3151-5p, targeting pathways involved in inflammation, oxidative stress, and smooth muscle cell (SMC) phenotypic stability. Functional pathway analysis highlighted the inhibition of actin cytoskeleton, ILK, and IL-17 signaling, essential for SMC differentiation and extracellular matrix remodeling. Gene interaction network analysis identified 21 central molecules, including CXCR3, ACACA, and BPGM, associated with lipid metabolism, inflammation, and vascular remodeling. This research elucidates the mechanism of ferroptosis in AD pathogenesis and establishes Fer-1 as a promising therapeutic intervention. AD and cardiac diseases share molecular mechanisms, risk factors, and pathological processes, positioning AD within the broader scope of cardiovascular pathology. By attenuating lipid peroxidation, oxidative stress, and inflammation, Fer-1 may have cardioprotective effects beyond AD, providing a foundation for future translational research in cardiovascular medicine. Full article

Sporothrix schenckii is a pathogenic fungus of worldwide distribution and one of the etiological agents of sporotrichosis. The cell wall is the first point of contact with host cells; therefore, its composition has been widely studied. It has a cell wall composed of chitin, β-glucans, and glycoproteins modified with N-linked and O-linked glycans. Protein O-linked glycosylation is mediated by two gene families, PMT and MNT. Therefore, we evaluated the relevance of protein O-linked glycosylation during the interaction of S. schenckii with the host. Independent silencing of the MNT1 and PMT2 was accomplished by interference RNA. Morphological analyses revealed defects in cell morphology in both yeast and mycelial cells; however, these defects differed between MNT1 and PMT2 silencing. Subsequently, the cell wall was characterized, and the silencing of these genes markedly changed cell wall organization. When the silenced strains interacted with human peripheral blood mononuclear cells, a reduced ability to stimulate the proinflammatory cytokines IL-6 and TNFα was found. However, the PMT2-silenced mutants also stimulated higher levels of IL-10 and IL-1β. Interaction with macrophages and neutrophils was also altered, with increased phagocytosis and decreased extracellular trap formation in both sets of silenced strains. Survival assays in Galleria mellonella larvae showed that silencing of any of these genes reduced the ability of S. schenckii to kill the host. In addition, the mutant strains showed defects in the adhesion to extracellular matrix proteins. These data indicate that MNT1 and PMT2 are relevant for cell wall synthesis and interaction with the host. Full article

Drug resistance remains a major barrier to effective cancer treatment, contributing to poor patient outcomes. Multifunctional biomaterials integrating electrical and catalytic properties offer a transformative strategy to target diverse resistance mechanisms. This review explores their ability to modulate cellular processes, remodel the tumor microenvironment (TME), and enhance drug delivery. Electrically active biomaterials enhance drug uptake and apoptotic sensitivity by altering membrane potentials, ion channels, and intracellular signaling, synergizing with chemotherapy. Catalytic biomaterials generate reactive oxygen species (ROS), activate prodrugs, reprogram hypoxic and acidic TME, and degrade the extracellular matrix (ECM) to improve drug penetration. Hybrid nanomaterials (e.g., conductive hydrogels, electrocatalytic nanoparticles), synergize electrical and catalytic properties for localized, stimuli-responsive therapy and targeted drug release, minimizing systemic toxicity. Despite challenges in biocompatibility and scalability, future integration with immunotherapy, personalized medicine, and intelligent self-adaptive systems capable of real-time tumor response promises to accelerate clinical translation. The development of these adaptive biomaterials, alongside advancements in nanotechnology and AI-driven platforms, represents the next frontier in precision oncology. This review highlights the potential of multifunctional biomaterials to revolutionize cancer therapy by addressing multidrug resistance at cellular, genetic, and microenvironmental levels, offering a roadmap to improve therapeutic outcomes and reshape oncology practice. Full article

The European wisent (Bison bonasus), an iconic yet genetically vulnerable species, faces ongoing conservation challenges due to a restricted gene pool. Advances in induced pluripotent stem cell (iPSC) technology offer promising prospects for preserving and restoring genetic diversity in endangered species. In this study, we sought to reprogram wisent somatic cells into iPSCs using the PiggyBac transposon system, a non-viral method known for being successfully applied in bovine species. We applied a six-factor reprogramming cocktail (OCT4, SOX2, KLF4, LIN28, c-MYC, NANOG) alongside small-molecule enhancers to fibroblasts isolated from adult wisent tissue. While initial colony formation was observed, the reprogrammed cells exhibited limited proliferation and failed to maintain stable pluripotency, suggesting intrinsic barriers to complete reprogramming. Despite optimizing culture conditions, including hypoxia and extracellular matrix modifications, the reprogramming efficiency remained low. Our findings indicate that wisent somatic cells may require alternative reprogramming strategies, such as new-generation delivery systems and epigenetic modulators, to achieve stable iPSC lines. This study underscores the need for species-specific optimization of reprogramming protocols and highlights the potential of emerging cellular technologies for conservation efforts. Future research integrating advanced reprogramming tools may pave the way for genetic rescue strategies in wisent and other endangered species. Full article

Dysregulated cell movement is a hallmark of cancer progression and metastasis, the leading cause of cancer-related mortality. The metastatic cascade involves tumour cell migration, invasion, intravasation, dissemination, and colonisation of distant organs. These processes are influenced by reciprocal interactions between cancer cells and the tumour microenvironment (TME), including immune cells, stromal components, and extracellular matrix proteins. The epithelial–mesenchymal transition (EMT) plays a crucial role in providing cancer cells with invasive and stem-like properties, promoting dissemination and resistance to apoptosis. Conversely, the mesenchymal–epithelial transition (MET) facilitates metastatic colonisation and tumour re-initiation. Immune cells within the TME contribute to either anti-tumour response or immune evasion. These cells secrete cytokines, chemokines, and growth factors that shape the immune landscape and influence responses to immunotherapy. Notably, immune checkpoint blockade (ICB) has transformed cancer treatment, yet its efficacy is often dictated by the immune composition of the tumour site. Elucidating the molecular cross-talk between immune and cancer cells, identifying predictive biomarkers for ICB response, and developing strategies to convert cold tumours into immune-active environments is critical to overcoming resistance to immunotherapy and improving patient survival. Full article

Uveal melanoma (UVM) is an aggressive cancer with a poor prognosis, particularly in metastatic cases. This study aimed to develop and validate a novel extracellular matrix (ECM) gene expression signature to predict prognosis and stratify patients by risk. ECM-related genes were identified and used to construct a prognostic model through Lasso–Cox regression analysis, leveraging RNA sequencing data from 80 UVM patients in The Cancer Genome Atlas (TCGA). The model was validated using an independent cohort of 63 UVM patients. Survival analyses, immune infiltration profiling, and functional enrichment analyses were conducted to evaluate the biological significance and clinical utility of the signature. The ECM signature stratified patients into high- and low-risk groups with significant differences in survival outcomes. High-risk patients showed elevated expression of MMP1 and MMP12, which are associated with ECM remodeling and immune modulation, alongside increased infiltration of immunosuppressive cells, such as M2 macrophages. Validation confirmed the prognostic value of the signature across cohorts. Functional analyses highlighted the involvement of ECM-related pathways, epithelial–mesenchymal transition, and immune system interactions in tumor progression. This ECM gene expression signature is a robust prognostic tool for UVM, offering insights into tumor biology and immune microenvironment interactions. It holds promise for improving patient stratification and guiding personalized therapeutic strategies. Further research is warranted to explore the functional roles of these genes in UVM progression. Full article