Search Results (359)

More than 30% of diabetic patients develop dermatopathies linked to inflammation and increased vascular permeability. Considering the role of the renin–angiotensin–aldosterone system (RAAS) in diabetic complications, this study examined whether aldosterone (ALDO) and the mineralocorticoid receptor (MR) contribute to diabetes-related skin microangiopathy. Vascular permeability was measured in normoglycemic rats and insulin-dependent (streptozotocin-induced) diabetic rats. The expression of MR, 11β-hydroxysteroid dehydrogenase type 2 (HSD11β2), vascular endothelial growth factor (VEGF), von Willebrand factor (vWF), and the tight junction protein ZO-1 was determined by PCR and immunohistochemistry. Diabetic rats received the MR antagonist eplerenone (EPL, 100 mg/kg) for 10 days. Additionally, the effects of ALDO and EPL on endothelial permeability were evaluated in human dermal microvascular endothelial cells (HMEC-1) using a Transwell system. Diabetic rats showed skin atrophy, collagen damage, elevated ALDO levels, reduced MR and HSD11β2 expression, and increased vascular permeability, along with upregulation of VEGF and vWF. EPL markedly reduced these abnormalities. In vitro, ALDO increased endothelial permeability under hyperglycemia, and EPL counteracted this effect. These findings indicate that activation of the ALDO/MR pathway promotes skin vascular permeability in diabetes through VEGF- and vWF-dependent mechanisms. MR blockade limits these changes, suggesting therapeutic potential in preventing diabetes-associated skin complications. Full article

Hypertension (HTN) and intestinal permeability (IP) are increasingly recognized as interrelated processes driven by shared oxidative and inflammatory mechanisms. This review synthesizes evidence linking HTN-induced vascular dysfunction to alterations in intestinal barrier integrity and explores the potential of dietary flavonoids as modulators of these pathologies. A narrative approach was used to synthesize findings from cellular, animal, and human studies that specifically address how flavonoids influence the molecular pathway connecting HTN and IP. Emerging evidence suggests that HTN-driven vascular injury, which is characterized by reduced nitric oxide bioavailability, increased reactive oxygen species, and pro-inflammatory signaling, contributes to tight junction disruption and increased IP. Mechanistic evidence indicates that flavonoids exert both direct antioxidant effects and indirect actions via the modulation of key cellular pathways. Preclinical and clinical data demonstrate that flavonoid-rich foods and isolated compounds can lower blood pressure, enhance endothelial function, and preserve intestinal barrier integrity by stabilizing tight junction proteins and attenuating pro-inflammatory signaling. Together, these findings highlight flavonoids as cross-system modulators that may mitigate HTN-associated increases in IP. Further research addressing sex, race, and age differences, as well as flavonoid bioavailability and dose optimization, is needed to clarify their translational potential. Full article

Background and Clinical Significance: Collagenous colitis is an uncommon form of microscopic colitis characterized by chronic watery diarrhea and thickening of the subepithelial collagen layer. While various medications have been implicated in its pathogenesis, paclitaxel-associated collagenous colitis remains exceptionally rare in the literature. Recognition of this adverse event is crucial for appropriate management, particularly in patients receiving dose-modified chemotherapy regimens. This case highlights the importance of considering drug-induced collagenous colitis in cancer patients presenting with severe diarrhea during chemotherapy. Case Presentation: We report a 71-year-old Japanese male with metastatic breast cancer who developed acute-onset collagenous colitis during paclitaxel treatment. His primary tumor was invasive ductal carcinoma with hormone receptor-positive, HER2-negative disease (ER+, PgR+, HER2-, Ki-67 46%) and progressive metastatic disease. Given pre-existing renal dysfunction, paclitaxel was initiated at 60% dose reduction. Sixteen days after treatment initiation, the patient experienced abrupt onset of profuse watery diarrhea with approximately 10 bowel movements daily, necessitating hospital admission. Colonoscopic evaluation demonstrated increased vascular permeability and superficial mucosal erosions. Histopathological analysis revealed diagnostic features of collagenous colitis with a markedly thickened subepithelial collagen band measuring 23 μm. Following immediate cessation of paclitaxel, the patient experienced complete resolution of diarrheal symptoms without subsequent relapse. Conclusions: This case represents a rare manifestation of paclitaxel-induced collagenous colitis. Clinicians should maintain heightened awareness of this potential complication in patients receiving taxane-based chemotherapy who develop significant diarrhea. Prompt recognition and immediate drug discontinuation are essential for favorable outcomes and symptom resolution. 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

This review reappraises the anti-inflammatory potential of the contact activation system (CAS) in intensive care through an evolutionary lens. The authors propose that coagulation factor XII (FXII) and related components evolved in terrestrial animals as a “foreign-surface sensing–immunothrombosis” module, helping to explain the minimal bleeding phenotype of FXII deficiency and the secondary loss of F12 in marine mammals. CAS shares components with the kallikrein–kinin system (KKS): alpha-coagulation factor XIIa (α-FXIIa) drives coagulation factor XI (FXI) activation to amplify coagulation, whereas betacoagulation factor XIIa (β-FXIIa) activates the KKS to generate bradykinin, promoting vasodilation and vascular leak. Beyond proteolysis, zymogen FXII signals via urokinase-type plasminogen activator receptor (uPAR) to induce neutrophil extracellular trap formation (NETosis), thereby amplifying immunothrombosis. Clinically, the relevance spans sepsis and extracorporeal organ support: pathogens can hijack CAS/KKS to facilitate invasion, and artificial surfaces such as extracorporeal membrane oxygenation (ECMO) circuits chronically trigger contact activation. In animal models, selective inhibition of FXII/FXI prolongs circuit life and attenuates pulmonary edema and inflammation without materially increasing bleeding. The review also catalogs “non-coagulation” roles of CAS members: Activated coagulation factor XI (FXIa) modulates endothelial permeability and smooth-muscle migration, and the FXII heavy chain exhibits direct antimicrobial activity—underscoring CAS as a nexus for coagulation, inflammation, and host defense. Overall, CAS inhibitors may couple “safe anticoagulation” with “cascade-level anti-inflammation,” offering a testable translational path for organ protection in the ICU alongside infection control and informing combined, precision strategies for anticoagulation and anti-inflammatory therapy. Full article

Bamboo often suffers from moisture-induced cracking, in which the structural and dimensional differences between nodes and internodes may be key contributing factors. Taking Phyllostachys edulis (Carrière) J. Houz. as an example, this study systematically examined the water absorption behavior and dimensional stability of bamboo nodes and internodes, and further analyzed their pore structure and chemical composition to provide a comprehensive understanding of their moisture response. This study systematically compared nodes and internodes of Phyllostachys edulis in water absorption behavior, dimensional stability, pore architecture, and vascular structure. Results showed that internodes exhibited higher water absorption rates and capacities in both short- and long-term tests, whereas nodes displayed lower water uptake and were prone to cracking during drying, indicating reduced dimensional stability. Anatomical and infrared analyses revealed that diaphragms, transverse vascular bundles, and spiral networks in nodes increased fluid path tortuosity, reducing longitudinal permeability. Pore structure analysis further indicated that internodes contained abundant pores facilitating rapid liquid transport, while node pores were mainly medium to large, favoring liquid retention but limiting permeability. Higher cellulose crystallinity and lignin content in nodes enhanced hydrophobicity, further restricting water penetration. Additionally, the complex fiber orientation in nodes induced anisotropic swelling and internal stress, increasing the risk of twisting and cracking. This multi-scale investigation elucidates the structural and compositional mechanisms underlying the observed differences in water absorption behavior and dimensional stability between nodes and internodes. These findings offer valuable insights for improving the moisture resistance, dimensional stability, and overall performance of bamboo materials in engineered applications, and provide a solid foundation for their targeted modification and optimization. Full article

The endothelium, once considered merely a vascular lining responsible for selective permeability to water and electrolytes, is now recognised as a key regulator of vascular tone through the release of mediators such as oxylipins, nitric oxide, and hyperpolarizing factors. This in vitro study investigated the biological activity of Vesvein, a natural formulation containing Diosmin/Hesperidin, Ruscus aculeatus, Bromelain, and Ananas comosus, on intestinal and endothelial cells. Vesvein enhanced intestinal cell viability and preserved barrier integrity, as demonstrated by increased tight junction expression at both single and double concentrations. In endothelial cells, the compound improved parameters linked to venous insufficiency, elevating nitric oxide production by approximately 1.39-fold at a single dose and 1.65-fold at a double dose. These findings indicate a potential role for Vesvein in supporting endothelial health and vascular function in vitro. Preliminary evidence from intestinal models further suggests preserved barrier properties, which may positively influence absorption and bioavailability, thereby enhancing its vascular benefits. Full article

Peripheral edema is a pathological condition caused by abnormal fluid accumulation in the interstitial space due to elevated vascular permeability and inflammation. This study evaluated the therapeutic efficacy of Terminalia chebula fruit extract (TCE) in inflammation-induced peripheral edema and clarified its molecular mechanisms. Using hydrogen peroxide (H₂O₂)-stimulated human umbilical vein endothelial cells (HUVECs), TCE was tested for effects on cell viability, inflammatory gene expression, intracellular reactive oxygen species, endothelial barrier integrity, and vascular endothelial growth factor (VEGF)-induced migration. Its influence on nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and mitogen-activated protein kinase (MAPK) signaling was examined. In vivo, TCE was assessed in acetic acid-induced peritoneal vascular permeability and carrageenan-induced paw edema models, followed by histological analysis and serum tumor necrosis factor-α (TNF-α) measurement. TCE restored cell viability (76.2% to 94.8%), reduced TNF, IL6, and PTGS2 mRNA expression, and decreased reactive oxygen species by 27.2%. It enhanced barrier integrity, increased transendothelial electrical resistance, and inhibited VEGF-induced migration. TCE suppressed NF-κB and MAPK activation. In vivo, TCE reduced Evans blue extravasation by 41.6% and paw edema by 67.5%. Histology showed reduced dermal thickening and inflammatory infiltration, and serum TNF-α levels were lowered. TCE attenuates peripheral edema by preserving endothelial barrier function and suppressing inflammatory signaling, supporting its potential as a therapeutic agent for inflammation-associated vascular dysfunction and edema. Full article

Diabetic retinopathy (DR) is a leading cause of vision loss globally and represents one of the most common microvascular complications of diabetes. In addition to metabolic disturbances associated with hyperglycemia, oxidative stress has emerged as a critical contributor to the onset and progression of DR. Oxidative stress, defined as an imbalance between the production of reactive oxygen species (ROS) and antioxidant defense mechanisms, leads to cellular injury, inflammation, and increased vascular permeability. In the diabetic retina, excessive ROS production promotes endothelial cell apoptosis, breakdown of the blood-retinal barrier (BRB), and induction of angiogenic factors such as vascular endothelial growth factor (VEGF). This review provides a comprehensive overview of the pathophysiology of DR, focusing on the molecular mechanisms of oxidative stress. Relevant studies were identified through a structured search of PubMed, Web of Science, and Scopus (2000–2025) using terms such as ‘diabetic retinopathy’, ‘oxidative stress’, and ‘antioxidants’. We explore current knowledge on oxidative stress-related biomarkers and therapeutic strategies targeting oxidative damage, including antioxidant compounds and mitochondrial protective agents. Recent findings from both experimental and clinical studies are summarized, highlighting the translational potential of oxidative stress modulation in DR management. Finally, future research directions are discussed, including biomarker standardization, personalized medicine approaches, and long-term clinical validation of antioxidant-based therapies. A deeper understanding of oxidative stress may offer valuable insights into novel diagnostic and therapeutic strategies for DR. Full article

Traumatic brain injury (TBI) disrupts the blood–brain barrier (BBB), resulting in increased permeability, neuronal loss, and cognitive dysfunction. This study investigates the therapeutic potential of thyroid hormone (T4) to reduce BBB dysfunction following moderate fluid percussion injury. T4 injection (intraperitoneal) after TBI restores the levels of pericytes and endothelial cells vital for BBB integrity, reduces edema by downregulating AQP-4 gene expression, and enhances levels of the tight junction protein ZO-1. T4 counteracts the TBI-related increase in MMP-9 and TLR-4, significantly reducing BBB permeability. Furthermore, T4 enhances the neuroprotective functions of astrocytes by promoting the activity of A2 astrocytes. Additionally, T4 treatment increases DHA levels (important for membrane integrity and function), stimulates mitochondrial biogenesis, and leads to a notable improvement in spatial learning and memory retention. These findings suggest that T4 has significant potential to reduce vascular leakage and inflammation after TBI, thereby improving cognitive function and maintaining BBB integrity. Full article

Background: Endothelial cells (EC), crucial components of the vascular system, are adaptable cells that maintain homeostasis and respond to pathological events through structural and functional plasticity. Hepatocyte growth factor (HGF) is a multifunctional cytokine that has been demonstrated to have protective and disruptive influence on the blood barrier function. In endothelial biology, its role is also poorly characterized. The present study explores the impact of supraphysiological concentrations of HGF on mouse brain endothelial cells (MBECs), scrutinizing how it alters their integrity and morphology. Methods: Two groups of MBECs—control (CTR) and experimental (EXP)—were analyzed at two time points: early passage (p5) and late passage (p41). The EXP-groups (p5 and p41) were treated with HGF at a concentration of 4 µL/mL. Cellular morphology was assessed with brightfield microscopy; protein expression and localization of the tight junction marker (ZO-1) and the endothelial marker (Factor VII related antigen/von Willebrand factor, vWf) were analyzed using Western blotting, immunocytochemistry, and confocal microscopy. Intercellular barrier function was estimated via Transendothelial Electric Resistance (TEER) and Transendothelial Dextran Permeability (TEDP) assays. Results: Microscopical analysis demonstrated a change in the morphology of the MBECs from a longitudinal, spindle-like shape to a rounded, more spheroid, cobblestone-like morphology under high-dose HGF treatment. Western blotting revealed a progressive decrease of ZO-1 expression in the EXP-groups. The expression of vWf did not show significant differences. Qualitative immunocytochemical staining: vWf showed consistent expression across all groups. ZO-1 displayed a punctate, well-defined membrane and cytoplasmic localization pattern in the CTR-groups at p5 and p41. In contrast, the p5 EXP-group demonstrated a shift to a more diffuse cytoplasmic pattern. At p41, the EXP-group displayed a markedly reduced ZO-1 signal with no clear-cut membrane localization. Confocal analysis: ZO-1: punctate membrane-associated localization in CTR-groups at p5 and 41. The EXP-groups at p5 and p41 confirmed the diffuse cytoplasmic ZO-1 distribution. Phalloidin: well-organized actin cytoskeleton in CTR-groups, but rearrangement and stress fiber disorganization in the EXP-groups, especially at p41. The merged images confirmed reduced co-localization of ZO-1 with actin structures. Barrier function: TEER values dropped significantly in HGF-treated cells. TEDP to small and medium molecular weight dextran increased markedly under HGF treatment. Conclusions: Our data demonstrate that supraphysiological doses of HGF in an in vitro MBEC-barrier-like model disrupt TJ organization, leading to morphological changes and functional weakening of the MBEC-barrier-like structure, as shown by uncoupling between ZO-1/F-actin cytoskeleton, reduced TEER, and increased size-selective paracellular permeability (TEDP). Full article

Osteoarthritis involves complex interactions between articular joint tissues and the immune system, which is implicated in molecular trafficking via barrier-function modulating cytokines. The current study aims to test effects of an acute spike in TNF-α or TGF-β on vascular barrier function at multiple length scales, from the heart to tissue compartments of the knee, and cellular inhabitants of those respective compartments, in a spontaneous guinea pig model of osteoarthritis. First we quantified the intensity of a fluorescent-tagged 70 kDa tracer, similar in size to albumin, the most prevalent transporter protein in the blood, in tissue compartments of bone (periosteum, marrow space, compact bone, and epiphyseal bone) and cartilage (superficial cartilage, calcified cartilage, and the interface between, i.e., the epiphyseal line), as well as at sites of tendon attachment to bone (entheses). We then examined tracer presence and intensity in the respective pericellular and extracellular matrix zones of bone and cartilage. Acute exposure to TGF-β reduced barrier function (increased permeability) at nearest vascular interfaces in four of eight tissue compartments studied, compared to TNF-α where one of eight tissue compartments showed significant diminishment in barrier function. The increase in permeability associated with reduced barrier function was observed at both tissue compartment and cellular length scales. The observation of pericellular transport of the albumin-sized molecules to osteocytes contrasts with previous observations of barrier function in healthy, untreated animals and is indicative of increased molecular transport in pericellular regions of musculoskeletal tissues in cytokine-treated animals. Understanding age- and disease-related changes in molecular transport within musculoskeletal structures, such as the knee joint, is crucial for elucidating the etiology and pathogenesis of osteoarthritis. Full article

One of the main targets for snake venoms in animal and human organisms is the circulatory system. Mechanisms of circulatory system injury within the victim’s body include, among others, the direct effect of snake toxins on structures in blood vessel walls. The interaction of a toxin with cells and the extracellular matrix of the vessel wall may manifest as cytotoxicity, leading to cell death by necrosis or apoptosis, and damage to vascular wall structures. Such interactions may increase capillary permeability, promoting hemorrhage or edema, and may also induce alterations in vascular tone, resulting in changes in blood pressure. Snake toxins may also affect the growth, function, and regenerative ability of the endothelium, thus modulating angiogenesis; some toxins exert protective or anti-atherosclerotic effects. Toxins interacting with the vasculature may be classified as enzymes (phospholipases A₂, metalloproteinases, L-amino acid oxidases, and hyaluronidases), proteins without enzymatic activity (vascular endothelial growth factors, disintegrins, C-type lectins and snaclecs, three-finger toxins, etc.), peptides (bradykinin-potentiating peptides, natriuretic peptides, sarafotoxins), and low-molecular-weight substances. This review summarizes the data on the vascular effects, particularly on the blood vessel wall, exhibited by various classes and groups of snake toxins. Full article

Lower extremity artery disease (LEAD), abdominal aortic aneurysm (AAA), and varicose veins (VV) are frequently underdiagnosed and undertreated peripheral vascular diseases that pose considerable public health challenges. More research is required to elucidate the pathophysiological mechanisms underlying these conditions and to identify novel diagnostic and therapeutic biomarkers. Therefore, in our study, we aimed to identify shared and distinct pathways associated with angiogenesis and inflammation in LEAD, AAA, and VV. The expression of 18 genes in peripheral blood mononuclear cells and the plasma levels of six proteins were compared between groups of 40 patients with LEAD, 40 patients with AAA, and 40 patients with VV. Independent RNA-seq and microRNA-seq data were integrated to predict differentially expressed transcription factors and microRNAs associated with the most significant genes. Gene Ontology functional analysis was performed to determine the potential biological effects of the observed dysregulations. The elevated expression of VEGFB and TGFB1, along with increased plasma levels of VEGF-C and reduced plasma levels of VEGF-A, were distinguishing features of patients with LEAD compared to those with AAA and VV. Decreased plasma levels of TGF-alpha and TGF-beta 1 were found to be indicative of varicose veins compared to individuals with arterial diseases (LEAD and AAA). Transcription factors and microRNAs potentially regulating the obtained signatures were identified and integrated into a hypothetical regulatory network. The observed dysregulations were found to be functionally associated with the response to hypoxia, the positive regulation of angiogenesis, chemotaxis, vascular permeability, and cell adhesion. The presented study identified dysregulations of key angiogenesis- and inflammation-related factors in peripheral blood mononuclear cells and plasma between LEAD, AAA, and VV patients, providing new insights into the shared and distinct molecular mechanisms underlying these diseases. Full article

Background and Clinical Significance: Acquired angioedema (AAE) is a rare and potentially life-threatening condition characterized by acquired deficiency of C1-inhibitor (C1-INH) resulting in hyperactivation of the classical complement pathway. AAE occurs in association with malignancies or autoimmune diseases. Infectious triggers are rarely encountered, and the underlying mechanisms have yet to be completely clarified. Case Presentation: This case involves a previously healthy 19-year-old male who was admitted with Mycoplasma pneumonia and oral ulcers, subsequently developing unilateral facial angioedema. Laboratory studies demonstrated reduced C4, decreased levels and activity of C1-INH, and reduced C1q, all consistent with acquired C1-INH deficiency. These findings were attributed to the presence of cold agglutinins, which are frequently observed in Mycoplasma pneumoniae infections. Following treatment with icatibant, a bradykinin B2 receptor antagonist, the patient’s angioedema resolved rapidly. An exhaustive workup found no evidence of underlying systemic disorders, and the patient did not experience any angioedema attacks following resolution of the infection. Conclusions: The presence of cold agglutinins, commonly associated with Mycoplasma infections, can precipitate a decline in C1-INH levels, resulting in complement pathway dysregulation. This disruption leads to an excess of bradykinin, followed by increased vascular permeability and localized edema. Full article