Search Results (9,296)

Individuals with rheumatoid arthritis (RA) face increased cardiovascular mortality due to heart failure (HF) complications. Post-translational modifications, such as citrullination (CIT) and malondialdehyde–acetaldehyde (MAA) adduction, are implicated in RA pathogenesis. However, their role in RA-associated HF is not well understood. This study examines the deposition of MAA and CIT in cardiac tissues of RA-HF patients and investigates how MAA and CIT adducts on fibrinogen (FIB-MAA-CIT) drive crosstalk between macrophages and endothelial cells in vitro. We demonstrated elevated MAA and CIT adducts, strong perivascular MAA-CIT co-localization, and increased perivascular collagen deposition in the myocardium of RA-HF patients compared to non-RA HF controls. Treating human coronary artery endothelial cells (HCAECs) with FIB-MAA-CIT induced upregulation of inflammatory markers including MCP-1, IL-6, ICAM-1, and VCAM-1 compared to unmodified FIB. This response was amplified when HCAECs were treated with cell culture media obtained from FIB-MAA-CIT-stimulated macrophages. FIB-MAA-CIT activation of macrophages engaged NF-κB and p38 signaling pathways and inhibition of these pathways reduced FIB-MAA-CIT-mediated macrophage cytokine secretion and subsequent HCAEC responses. In summary, our findings support a novel mechanism by which endogenously modified proteins drive macrophage–endothelial cell crosstalk, promoting myocardial inflammation. Targeting these post-translational modifications may present novel therapeutic strategies to mitigate HF in RA. Full article

Perlecan, a major heparan sulfate proteoglycan in the vascular basement membrane, plays an essential role in maintaining endothelial barrier integrity, regulating fibroblast growth factor-2 signaling, and exerting anticoagulant activity. Although alterations in perlecan expression are implicated in the initiation and progression of atherosclerosis, the upstream regulatory mechanisms remain unclear. In this study, we investigated the effects of extracellular ATP on perlecan expression in vascular endothelial cells. ATP, but not ADP or adenosine, suppressed perlecan expression at both mRNA and protein levels in a time- and concentration-dependent manner. This suppression was recovered by knockdown of P2Y2 receptor (P2Y2R), but not by P2X4 receptor, P2X7 receptor, or P2Y1 receptor knockdown, indicating the selective involvement of P2Y2R. Mechanistically, ATP reduced Akt phosphorylation mediated by P2Y2R, and inhibition of Akt by inhibitors decreased perlecan expression, whereas inhibitors of phosphoinositide 3-kinase, mammalian target of rapamycin complex 1, extracellular signal-regulated kinase, p38 mitogen-activated protein kinase, c-Jun N-terminal kinases did not exhibit this recovery effect. These results suggest that ATP downregulates perlecan synthesis via the P2Y2R-mediated inhibition of Akt signaling. Given that ATP is markedly elevated under pathological conditions, such as inflammation and platelet activation, suppression of perlecan synthesis is an important mechanism by which ATP promotes vascular disease progression. Full article

Background: Polybacterial infections associated with periodontitis are increasingly linked to systemic vascular complications, yet the underlying endothelial mechanisms remain unclear. This study investigated how a consortium of red-complex bacteria (Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola) and orange complex (Fusobacterium nucleatum) affects oxidative stress, inflammation, metabolism, and apoptosis in endothelial cells, and whether L-Sepiapterin [a tetrahydrobiopterin (BH4) precursor via salvage pathway] or bardoxolone methyl (CDDO-Me) [a potent nuclear factor erythroid 2-related factor 2 (Nrf2) activator)] could provide protection. Methods: Human umbilical vein endothelial cells (HUVECs) were infected for 12–72 h and treated with L-Sepiapterin or CDDO-Me. Nitric oxide (NO), BH4, and reactive oxygen species (ROS) levels were quantified, and mRNA expression of key genes regulating nitric oxide synthase activity, antioxidant defense, inflammation (TLR4/NF-κB, cytokines), metabolism (PI3K-AKT-PEA-15), and apoptosis (FAS–caspase pathway) was analyzed. Results: Infection markedly reduced NO and BH4, elevated ROS, activated TLR4/NF-κB and proinflammatory cytokines, disrupted PI3K/AKT signaling, and triggered endothelial apoptosis. Treatments with L-Sepiapterin and CDDO-Me restored NO bioavailability, reduced oxidative and inflammatory responses, normalized metabolic gene expression, and attenuated apoptosis, with CDDO-Me showing more promising effects. This study provides the mechanistic insight linking periodontal polybacterial infection to endothelial dysfunction and metabolic impairment such as diabetes, suggesting that redox-modulating strategies such as L-Sepiapterin and CDDO-Me may help prevent vascular damage associated with periodontal disease. Full article

Branching structures such as vascular networks are representative morphological patterns in living systems, and they often arise from collective cell migration. Angiogenesis, the sprouting of new blood vessels from pre-existing ones, is a fundamental process in development. Experimental and theoretical studies have demonstrated that sprout formation depends on the collective movements and shapes of endothelial cells, as well as the remodelling of the extracellular matrix. Many discrete models have been proposed to describe cell dynamics, successfully reproducing vascular patterns and collective behaviours. In this study, we present a two-dimensional mathematical model that represents each endothelial cell as an ellipse and incorporates the effects of the extracellular matrix. We performed computer simulations under two scenarios: invasion from a pre-formed sprout and collective advancement into an extracellular matrix region. The results show that the extracellular matrix helps maintain linear sprout extension and suppresses the formation of dispersed or curved branches, while elongated cell shapes promote sprouting more effectively than round cells. The model also reproduces experimentally observed behaviours such as tip-cell replacement and the mixing of cells within sprouts. These findings highlight the importance of integrating cell shape and extracellular matrix remodelling to understand early blood vessel formation. Full article

Retinal ischemia is a key factor in the progression of vision-threatening ocular diseases, including central retinal artery/vein occlusion, exudative age-related macular degeneration (eAMD), and proliferative diabetic retinopathy. This study investigates the effects of paeoniflorin along with its related neuroprotective molecular pathways in the treatment of retinal ischemia. Free radical or ischemic-like damage was induced by incubating retinal pigment epithelium (RPE) cells for 24 h with 1 mM hydrogen peroxide (H₂O₂) or by subjecting retinal neuronal cells to 8 h of oxygen–glucose deprivation (OGD). Both treatments caused significant cell loss. Treatment with paeoniflorin significantly increased cell viability at 0.5 mM in both cell types. In a Wistar rat model of retinal ischemia and reperfusion (I/R) elicited by sustained high intraocular pressure (HIOP), pre-treatment with 0.5 mM paeoniflorin mitigated the ischemia-induced decline in ERG b-wave amplitude, reduction in whole and inner retinal thickness, loss of fluorogold-labeled retinal ganglion cells, and formation of apoptotic cells. Meanwhile, paeoniflorin effectively downregulated pro-neovascular mediators β-catenin, hypoxia-inducible factor 1-alpha (HIF-1α), vascular endothelial growth factor (VEGF), and the pro-inflammatory/angiogenic biomarker angiopoietin-2 (Ang-2), producing effects similar to the Wnt/β-catenin inhibitor (dickkopf-related protein 1), anti-angiogenic pigment epithelium-derived factor (PEDF), and anti-VEGF Avastin (bevacizumab). These findings suggest that paeoniflorin may protect against retinal ischemia through its anti-inflammatory, anti-neovascular/angiogenic, antioxidative, and neuroprotective properties. Full article

Colon cancer (CC) is a common malignancy characterized by poor prognostic outcomes and considerable mortality. Oxaliplatin (OXP) is commonly used in the treatment of CC; however, its efficacy may be limited by side effects and the development of resistance. β-sitosterol (β-Sit), a phytosterol derived from plants, has been documented to be effective in the treatment of tumors. This study aimed to investigate the potential of β-Sit to enhance the antitumor efficacy of OXP in COLO-205 cells, focusing on apoptosis induction and suppression of the vascular endothelial growth factor A (VEGF-A)/survival pathway. Molecular docking studies were performed to assess the binding affinity of β-Sit with the target proteins B-cell lymphoma 2 (Bcl-2), phosphoinositide 3-kinase (PI3K), and VEGF receptor-2 (VEGFR-2). COLO-205 cells were treated with OXP, β-Sit, or a combination of OXP + β-Sit for 48 h. The combination treatment substantially lowered the IC₅₀ achieved with 3.24 µM of OXP and 36.01 µM of β-Sit, compared to 25.64 µM for OXP alone and 275.9 µM for β-Sit alone, demonstrating a pronounced synergistic impact. The combined therapy altered the cell cycle distribution by decreasing the number of cells in the G0/G, S, and G2/M phases, coupled with an increase in the Sub-G1 population. Furthermore, apoptosis was augmented by a shift in cell death from necrosis to late apoptosis, as indicated by an increased BAX/BCL2 ratio relative to each treatment alone. Moreover, the inhibitory effect on angiogenesis was enhanced via the reduction of VEGF-A, and β-catenin and nuclear factor κB (NF-κB-p65) were suppressed, thereby preventing the growth and survival of resistant cancer cells. Additionally, molecular docking supported high binding affinities of β-Sit to Bcl-2, PI3K, and VEGFR-2. This study highlights the potential of β-Sit to enhance the anti-cancer efficacy of OXP in CC. Full article

Curcuma phaeocaulis, a perennial herb of the ginger family, has been used to treat many diseases in traditional medicine systems. This study aimed to extract, isolate, and purify a homogeneous polysaccharide from C. phaeocaulis, conduct preliminary structural characterization, and evaluate its antioxidant activity at the cellular level. The structure of the purified polysaccharide (CPAP-1) was characterized using size exclusion chromatography (SEC), chemical derivatization analysis (CDA), GC-MS, FT-IR, and NMR. The results showed that CPAP-1 has an apparent molecular weight of 118.122 kDa and is hypothesized to be an arabinogalactan with a backbone composed of →3,6)-β-d-Galp-(1→ and →3)-β-d-Galp-(1→ residues, a structure that is relatively novel in Curcuma longa. In vitro antioxidant assays demonstrated that CPAP-1 possesses potent antioxidative stress activity, effectively scavenging both DPPH and hydroxyl radicals. Furthermore, cellular experiments revealed that at concentrations of 500 and 750 mg/L, CPAP-1 significantly protected human umbilical vein endothelial cells (HUVECs) against H₂O₂-induced oxidative damage. In conclusion, these findings suggest that CPAP-1 could be developed as a natural antioxidant, functional food, or therapeutic agent for preventing and mitigating oxidative stress-related vascular injury, providing a theoretical basis for further development and application. Full article

The treatment of wounds, most of which are complications of chronic diseases, poses a significant clinical challenge. Hybrid systems based on hyaluronic acid containing growth factors are a promising prospect for the treatment of chronic wounds. Hyaluronic acid supports fibroblast proliferation, migration, and adhesion to the wound site, and stimulates collagen production. Growth factors (GF), such as epidermal growth factor (EGF), fibroblast growth factor (FGF), and vascular endothelial growth factor (VEGF), influence the normal proliferation and migration of keratinocytes and fibroblasts. This review aims to summarise the current state of knowledge regarding their therapeutic potential. Google Scholar, Web of Science, and Medline (PubMed) databases were searched. Eighteen studies, including basic, preclinical, and clinical studies, were included in the review. The studies confirm the therapeutic potential of the developed formulations. Collagen/hyaluronic acid and alginate/hyaluronic acid systems are biocompatible and biodegradable matrices that provide a moist wound environment, which promotes cell migration and proliferation. EGF stimulates the proliferation and migration of keratinocytes, which accelerates re-epithelialisation. bFGF supports angiogenesis by stimulating the proliferation and migration of vascular endothelial cells. The effect of these actions indirectly leads to increased production of VEGF and HGF cytokines, which support the formation of granulation tissue. The VEGF-containing dressing stimulated vascularisation and the production of collagen type-1 and fibronectin. Only one clinical study conducted in this field indicates the need for further research in this area. Full article

This study presents a protocol for co-culturing pancreatic islet cell clusters derived from pancreatic tissue with human umbilical vein endothelial cells (HUVECs) on Matrigel using a specialized culture medium to form vascularized pancreatic islet organoids. We established a novel culture system for vascularized pancreatic islet organoids and compared the survival and insulin secretion capabilities of pancreatic islet cells in the presence and absence of glucose stimulation. Our results indicate that matrix adhesive materials can effectively facilitate the self-assembly of the vascularized endothelial cell–pancreatic islet organoids complex. Vascularized HUVEC prolongs the survival of pancreatic islet organoids in vitro. Moreover, the interaction between vascularized HUVEC and pancreatic islets significantly enhances the insulin secretion ability in response to glucose stimulation. This study reports a protocol for the long-term in vitro culture of pancreatic islet organoids, offering methods for the vascularization of pancreatic islet organoids on Matrigel. These data contribute to the understanding of how vascularization impacts the fate and function of pancreatic islet organoids, although the specific mechanism still requires further clarification. Full article

In recent years, the L-arginine/nitric oxide (NO) pathway has garnered increasing attention across a range of pathological conditions, including skin diseases. NO is an important modulator of skin homeostasis, being actively involved in numerous processes such as vasodilation, keratinocyte proliferation, melanogenesis and cell signaling. Under inflammatory conditions, post-translational changes in L-arginine take place, resulting in the synthesis of methylarginines including monomethylarginine (MMA), asymmetric dimethylarginine (ADMA), and symmetric dimethylarginine (SDMA). Once ADMA and MMA are generated, they compete with L-arginine to bind to the active site of NO synthase, which reduces the production of NO. Additionally, SDMA inhibits the transport of L-arginine, leading to a lower concentration of this amino acid within cells. Consequently, by impacting both the availability of L-arginine and the production of NO, conditions favoring oxidative stress and endothelial dysfunction are created. Dysregulation of L-arginine/NO pathway is closely related to inflammation and oxidative stress, two events that play a cardinal role in the pathogenesis of chronic inflammatory skin diseases. We conducted a narrative review that synthesizes current evidence on methylarginine levels in patients with chronic inflammatory skin diseases. Our aim was to enhance our knowledge about the role of these compounds in pathogenesis and provide new insights into the mechanisms underlying these conditions that can be the basis for novel diagnostic biomarkers and therapies. Full article

Desmosomal junctions provide structural stability supporting concerted cardiomyocyte contractility. Previously, we demonstrated that a deficiency in the desmosomal transmembrane cadherin desmoglein 2 (Dsg2) reduces desmosome formation and disrupts cardiac morphogenesis, leading to excessive endothelial-to-hematopoietic cell transformation and embryonic lethality. It remained unclear whether this phenotype was specifically driven by Dsg2-deficiency or was a broader consequence of impaired desmosome adhesion. To address this question, we generated Pkp2^mt/mt mouse embryos lacking the desmosomal plaque protein Pkp2, which resulted in loss of desmosome formation. Despite the absence of cardiac wall rupture, Pkp2^mt/mt and some Pkp2^wt/mt presented accumulations of Ter-119⁺ blood cells and RUNX1⁺/CD44⁺ hematopoietic stem cells in the pericardial space. Remarkably, in Pkp2^mt/mt hearts, the epicardium was detached from the myocardium, contained rounded cells expressing the hematopoietic stem cell marker RUNX1, and showed altered intermediate filament expression. These findings suggest a potential trans-differentiation of the epicardial cells into hematopoietic cells. In conclusion, deficiencies in both Dsg2 and Pkp2 promote hematopoiesis in the developing murine heart but target different cell types, i.e., endothelial cells, which lack desmosomes, or desmosome-containing epicardial cells. Our results provide evidence for the involvement of Pkp2 in epicardial morphogenesis and remodeling. Full article

Ischemic stroke remains one of the most catastrophic diseases in neurology, in which, due to a disturbance in the cerebral blood flow, the brain is acutely deprived of its oxygen and glucose oligomer, which in turn rapidly leads to energetic collapse and progressive cellular death. There is now increasing evidence that this type of stroke is not simply a type of ‘oxidative stress’ but rather a programmable loss-of-redox homeostasis, within which electron flow and the balance of oxidants/reductants are cumulatively displaced at the level of the single molecule and at the level of the cellular area. The advances being made in cryo-electron microscopy, lipidomics, and spatial omics are coupled with the introduction of a redox code produced by the interaction of the couples NADH/NAD⁺, NADPH/NADP⁺, GSH/GSSG, BH₄/BH₂, and NO/SNO, which determine the end results of the fates of the neurons, glia, endothelium, and pericytes. Within the mitochondria, pathophysiological events, including reverse electron transport, succinate overflow, and permeability transition, are found to be the first events after reperfusion, while signals intercommunicating via ER–mitochondria contact, peroxisomes, and nanotunnels control injury propagation. At the level of the tissue, events such as the constriction of the pericytes, the degradation of the glycocalyx, and the formation of neutrophil extracellular traps underlie microvascular failure (at least), despite the effective recanalization of the vessels. Systemic influences such as microbiome products, oxidized lipids, and free mitochondrial DNA in cells determine the redox imbalance, but this generally occurs outside the brain. We aim to synthesize how the progressive stages of ischemic injury evolve from the cessation of flow to the collapse of the cell structure. Within seconds of injury, there is reverse electron transport (RET) through mitochondrial complex I, with bursts of superoxide (O₂•⁻) and hydrogen peroxide (H₂O₂) being produced, which depletes the stores of superoxide dismutase, catalase, and glutathione peroxidase. Accumulated succinate and iron-induced lipid peroxidation trigger ferroptosis, while xanthine oxidase and NOX2/NOX4, as well as uncoupled eNOS/nNOS, lead to oxidative and nitrosative stress. These cascades compromise the function of neuronal mitochondria, the glial antioxidant capacity, and endothelial–pericyte integrity, leading to the degradation of the glycocalyx with microvascular constriction. Stroke, therefore, represents a continuum of redox disequilibrium, a coordinated biochemical failure linking the mitochondrial metabolism with membrane integrity and vascular homeostasis. Full article

Streptozotocin (STZ) is an alkylating agent that has neurotoxic effects when injected into the cerebral ventricles (ICV) and also models many other features of Alzheimer’s disease. However, the mechanisms of STZ neurotoxicity are not well understood. In this study, we hypothesized that some of the neurotoxic effects of STZ could be due to direct activities on brain endothelial cells and astrocytes, which are key in forming and supporting the functions of the blood–brain barrier (BBB), respectively. To test this hypothesis, we characterized the changes induced by STZ either in cultures of human-induced pluripotent stem cell (iPSC)-derived brain endothelial-like cells (iBECs), which form an in vitro BBB model, or in primary human astrocytes. We found that STZ at a dosage of 5 mM caused a delayed reduction in the transendothelial electrical resistance (TEER) of iBECs at 7–11 days post-treatment, indicating induction of BBB leakage. Additionally, we observed significant increases in albumin leakage across the monolayer, altered iBEC morphology, and reductions in tight junction proteins, suggesting that STZ causes BBB disruption. We further found that the BBB glucose transporter GLUT-1 was reduced in iBECs, as was the total number of iBECs. In astrocytes, the 5 mM dose of STZ reduced the GFAP signal and total number of cells, suggesting that STZ has anti-proliferative and/or toxic effects on astrocytes. Together, these data support that STZ’s neurotoxic effects could be due, in part, to its direct toxic activities on brain endothelial cells and astrocytes. Full article

Background: Previous studies have indicated an association between endoplasmic reticulum stress (ERS) and the formation of kidney stones. To further investigate this mechanism, this research sought to identify key genes linked to ERS in calcium oxalate (CaOx) kidney stones. Methods: Key cells with the highest ERS-related gene (ERSRG) scores were identified through single-cell analysis. These key cells were then categorized into high- and low-score groups based on their average ERSRG scores. To identify key genes, we analyzed the intersection of key ERSRGs and differentially expressed genes (DEGs) within key cells, focusing on genes demonstrating significant expression differences between control and CaOx kidney stone samples. A nomogram was constructed using these key genes to predict the risk of CaOx kidney stones. Gene set enrichment analysis (GSEA) was further performed to explore the functions of these key genes in the disease. Additionally, secondary clustering analysis was conducted on key cells to identify subtypes and evaluate the expression of key genes within these subtypes. Finally, the identified key genes were validated using quantitative real-time PCR (qRT-PCR) and Western blot analysis on cultured HK-2 cells, which were exposed with 2 mM CaOx for 24 h at 37 °C with 5% CO₂ or incubated with regular culture medium. Results: Endothelial cells were identified as key cells, and nine key genes were pinpointed in CaOx kidney stones: ACSL4, PTK2, DUSP4, MMP7, PHLDB2, TGM2, PPT1, SPARCL1, and LTF. The nomogram developed from these key genes demonstrated robust predictive ability for CaOx kidney stones risk. Additionally, GSEA revealed that olfactory transduction was enriched by key genes except PTK2. Secondary clustering analysis identified four key cell subtypes within endothelial cells, with LTF, MMP7, and SPARCL1 showing significantly differential expression between control and CaOx kidney stones groups across all key cell subtypes. qRT-PCR and Western blot analyses revealed that, compared to the control group, CaOx-exposed HK-2 cells exhibited significantly increased expression of ACSL4, MMP7, TGM2, PPT1, and LTF (p < 0.05), while showing significantly decreased expression of PTK2, DUSP4, SPARCL1, and PHLDB2 (p < 0.05). Conclusions: This study identified key genes associated with ERS in CaOx kidney stones through single-cell and transcriptomic analysis. The discovery of these genes provides new insights into the treatment of CaOx kidney stones and offers valuable references for subsequent research. Future research should focus on elucidating the precise roles of these candidate genes in CaOx stone pathogenesis to assess their potential for therapeutic intervention. Full article

The vascular endothelium serves as a critical barrier preventing the transmigration of monocytes, circulating lipoproteins, and other molecules into the subendothelial space, and plays a vital role in regulating vascular tone. A dysfunctional and inflamed endothelial layer in response to disturbed blood flow or other proatherogenic risk factors is the initiating event in the pathogenesis of atherosclerosis, suggesting the importance of an intact and properly functioning endothelium in preventing the onset and progression of this disease. Accumulated evidence demonstrates the significant role of matricellular proteins, which are non-structural and secretory extracellular matrix (ECM) proteins, in the development of atherosclerosis. These proteins exert multifaceted effects on endothelial cells (ECs) ranging from reactive oxygen species (ROS) production, endoplasmic reticulum stress, and expression of adhesion molecules to autophagy and compromised barrier function via stimulating various molecular mechanisms. Given the critical roles of these processes in EC function and atherosclerosis, a better understanding of signaling pathways governed by matricellular proteins in ECs is required to develop therapeutic strategies for suppressing or preventing atherosclerosis and related cardiovascular diseases (CVDs). This review comprehensively summarizes the existing literature on the diverse roles of matricellular proteins in regulating EC inflammation and function, and highlights their potential as viable therapeutic targets for maintaining vascular health and inhibiting the progression of atherosclerosis. Full article