Search Results (392)

Diabetes mellitus severely impairs skeletal muscle regeneration after injury, limiting satellite cell activation and angiogenesis and disrupting barrier integrity while increasing fibrosis. Hypobaric hypoxia has been proposed to improve the regenerative microenvironment through hypoxia-responsive signaling, but its temporal effects and the coordination between vascular and myogenic programs in diabetic muscle remain unclear. To clarify these processes, adult male mice were divided into five groups: diabetes mellitus control (DM), cardiotoxin-injured (CTX) diabetes assessed on days 7 and 14 (CTX7, CTX14), and hypobaric-hypoxia-treated diabetic injury assessed on days 7 and 14 (H+CTX7, H+CTX14). Animals in the hypoxia groups were exposed to a hypobaric hypoxia chamber for 8 h per day for 14 days. Fibrosis, angiogenic and myogenic markers, and endothelial junctional genes were examined using histology, immunofluorescence, immunoblotting, and qRT-PCR (Quantitative Real-Time PCR). Hypobaric hypoxia on day 7 enhanced HIF-1α (hypoxia-inducible factor 1 alpha), VEGF (vascular endothelial growth factor), eNOS (endothelial nitric oxide synthas), Kdr (kinase insert domain receptor, VEGFR-2), and Angpt2 (angiopoietin-2) expression, accompanied by simultaneous endothelial sprouting and early myogenic stimulation compared to CTX7. Improvements were observed in Angpt1 (angiopoietin-1), Cdh5 (cadherin-5, VE-cadherin), Emcn (endomucin), the Angpt1/Angpt2 ratio, and CD31 density. Myogenin and MyHC (myosin heavy chain) were induced with a reduction in eMyHC (embryonic myosin heavy chain) in accordance with stabilization of endothelium and maturation of fibers, which occurred by day 14. A decrease in fibrosis and an increase in the myofiber cross-sectional area occurred. These findings suggest that hypobaric hypoxia modulates HIF-1α signaling, which in turn induces the VEGF-Kdr-eNOS pathway and the angiopoietin–Tie2–VE-cadherin pathway. Together, these pathways coordinate vascular remodeling and myogenic regeneration, ultimately improving the structural and functional recovery of diabetic muscle. Full article

The intra- and intercellular signaling molecule nitric oxide (NO) is produced in endothelial cells by the activity of endothelial NO synthase (eNOS). Upon formation, NO diffuses into the underlying vascular smooth muscle cells, where it activates NO-sensitive guanylyl cyclase (NO-GC) resulting in the production of cyclic guanosine 3′,5′-monophosphate (cGMP) from guanosine 5′-triphosphate (GTP). Inducing vasodilatation, inhibiting platelet aggregation and leukocyte adhesion, and inhibiting the proliferation and migration of vascular smooth muscle cells, the NO-cGMP signaling leads to a number of anti-inflammatory processes. Inflammation-dependent elevated concentrations of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in blood vessels of inflamed dental pulp induce an uncoupling of eNOS and oxidized NO-GC, leading to a disruption of NO-cGMP signaling. Endothelial dysfunction in inflamed dental pulp alters cell–cell and cell–matrix interactions, reducing the regenerative and reparative potential of the dentin–pulp complex in response to carious lesions. In the therapeutic management of caries, it is essential to consider the presence of endothelial dysfunction in the inflamed dental pulp. The utilization of NO-GC stimulators and activators in indirect and direct pulp capping materials may enhance the regeneration and repair potential of inflamed dental pulp. Full article

Endothelial nitric oxide synthase (eNOS, NOS3) regulates steroidogenesis, redox signalling, and the vascular tone of the ovaries. Despite varying outcomes in previous studies, the prevalent NOS3 rs1799983 (Glu298Asp) polymorphism may influence endocrine function during controlled ovarian stimulation (COS). On the retrieval day, we assessed follicular-fluid hormones, day-3 hormones, and controlled ovarian stimulation (COS) outcomes (follicles, oocytes, MII oocytes, embryos) in 62 antagonist IVF/ICSI cycles classified by NOS3 genotype (GG/GT/TT). The outcomes for COS and early-cycle hormones were mostly consistent across all genotypes. A similar allele-dose pattern was seen for baseline oestradiol (GG < GT < TT), with heterozygous carriers displaying higher levels of follicular-fluid β-hCG relative to GG individuals. No changes were seen in follicle count, oocyte production, nuclear maturation, or embryo development. Baseline oestradiol and follicular β-hCG serve as the principal indications of the modest, context-dependent endocrine effects of the NOS3 rs1799983 polymorphism in antagonist cycles. To clarify the clinical significance of these intricate genotype-associated patterns, additional comprehensive, genotype-balanced investigations that include direct NO-pathway phenotyping are essential. Full article

Cardiovascular diseases (CVDs) remain a leading cause of mortality worldwide. According to the WHO, every year, there is an increase in the rate of death globally due to CVDs, stroke, and myocardial infarction. Several risk factors contribute to the development of CVDs, one of which is hypoxia, defined as a reduction in oxygen levels. This major stressor affects aerobic species and plays a crucial role in the development of cardiovascular disease. Research has uncovered the “hypoxia-inducible factors (HIFs) switch” and investigated the onset, progression, acute and chronic effects, and adaptations of hypoxia, particularly at high altitudes. The hypoxia signalling pathways are closely linked to natural rhythms such as the circadian rhythm and hibernation. In addition to genetic and evolutionary factors, epigenetics also plays an important role in postnatal cardiovascular responses to hypoxia. Oxidized LDL-C initiates atherosclerosis amidst oxidative stress, inflammation, endothelial dysfunction, and vascular remodelling in CVD pathogenesis. Anti-inflammatory and antioxidant biomarkers are needed to identify individuals at risk of cardiovascular events and enhance risk prediction. Among these, C-reactive protein (CRP) is a recognized marker of vascular inflammation in coronary arteries. Elevated pro-atherogenic oxidized LDL (oxLDL) expression serves as an antioxidant marker, predicting coronary heart disease in apparently healthy men. Natural antioxidants and anti-inflammatory molecules protect the heart by reducing oxidative stress, enhancing vasodilation, and improving endothelial function. For instance, the flavonoid quercetin exerts antioxidant and anti-inflammatory effects primarily by activating the Nrf2/HO-1 signaling pathway, thereby enhancing cellular antioxidant defense and reducing reactive oxygen species. Carotenoids, such as astaxanthin, exhibit potent antioxidant activity by scavenging free radicals and preserving mitochondrial integrity. The alkaloid berberine mediates cardiovascular benefits through activation of AMO-activated protein kinase (AMPK) and inhibition of nuclear factor kappa B [NF-kB] signalling, improving lipid metabolism and suppressing inflammatory cytokines. Emerging evidence highlights microRNAs (miRNAs) as potential regulators of oxidative stress via endothelial nitric oxide synthase (eNOS) and silent mating-type information regulation 2 homolog (SIRT1). While the exact mechanisms remain unclear, their benefits are likely to include antioxidant and anti-inflammatory effects, notably reducing the susceptibility of low-density lipoproteins to oxidation. Additionally, the interactions between organs under hypoxia signalling underscore the need for a comprehensive regulatory framework that can support the identification of therapeutic targets, advance clinical research, and enhance treatments, including FDA-approved drugs and those in clinical trials. Promising natural products, including polysaccharides, alkaloids, saponins, flavonoids, and peptides, as well as traditional Indian medicines, have demonstrated anti-hypoxic properties. Their mechanisms of action include increasing haemoglobin, glycogen, and ATP levels, reducing oxidative stress and lipid peroxidation, preserving mitochondrial function, and regulating genes related to apoptosis. These findings emphasise the importance of anti-hypoxia research for the development of effective therapies to combat this critical health problem. A recent approach to controlling CVDs involves the use of antioxidant and anti-inflammatory therapeutics through low-dose dietary supplementation. Despite their effectiveness at low doses, further research on ROS, antioxidants, and nutrition, supported by large multicentre trials, is needed to optimize this strategy. Full article

Background: Essential hypertension is associated with an increased risk of pulmonary hypertension (PH). PH is diagnosed more frequently in females. Little is known about the effects of a plant-based diet (PBD) in improving lung abnormalities in PH. Methods: We compared 28- and 40-week-old female normotensive Wistar Kyoto and spontaneously hypertensive rats (SHR), maintained from the age of 4 weeks on a control refined diet or a PBD, comprising 28% fruits, vegetables, nuts and legumes. A subset of control SHRs were switched to the PBD at 28 weeks of age. Lungs were taken for protein and histological analysis. Results: Relative to WKYs, SHRs consuming the control diet exhibited decreased lung endothelial nitric oxide synthase (eNOS). PBD consumption by SHRs prevented and reversed this phenotype. Expression of E-cadherin was also reduced in SHRs. This reduction was attenuated by PBD consumption treatment. The phosphorylation of extracellular signal-regulated kinase (ERK)1/2 in the lung was increased in SHRs and attenuated by PBD. The expression of activated transforming growth factor (TGF)-β1 was also attenuated by a PBD. Conclusions: The PBD favorably mediated hypertension-induced pulmonary molecular abnormalities in lung endothelium, epithelial junction and pro-fibrotic signaling. Future studies should assess the effects of a PBD in improving PH and lung function. Full article

Hemodynamics significantly impact the biology of endothelial cells (ECs) lining the blood vessels. ECs are exposed to various hemodynamic forces, particularly frictional shear stress from flowing blood. While physiological flows are critical for the normal functioning of ECs, abnormal flow dynamics, known as disturbed flows, may trigger endothelial dysfunction leading to atherosclerosis and other vascular conditions. Such flows can occur due to sudden geometrical variations and vascular abnormalities in the cardiovascular system. In the current study, a microfluidic system was used to investigate the impact of different flow conditions (i.e, normal vs. disturbed) on ECs in vitro. We particularly explored the relationship between specific flow patterns and cellular pathways linked to oxidative stress and inflammation related to atherosclerosis. Here, we utilized a 2D cell culture perfusion system featuring an immortalized human vascular endothelial cell line (EA.hy926) connected to a modified peristaltic pump system to generate either steady laminar flows, representing healthy conditions, or disturbed oscillatory flows, representing diseased conditions. EA.hy926 were exposed to an oscillatory flow shear stress of 0.5 dynes/cm² or a laminar flow shear stress of 2 dynes/cm² up to 24 h. Following flow exposure, cells were harvested from the perfusion chamber for quantitative PCR analysis of gene expression. Reactive oxygen species (ROS) generation under various shear stress conditions was also measured using DCFDA/H2DCFDA fluorescent assays. Under oscillatory shear stress flow conditions (0.5 dynes/cm²), EA.hy926 ECs showed a 3.5-fold increase in the transcription factor nuclear factor (NFκ-B) and a remarkable 28.6-fold increase in cyclooxygenase-2 (COX-2) mRNA expression, which are both proinflammatory markers, compared to static culture. Transforming growth factor-beta (TGFβ) mRNA expression was downregulated in oscillatory and laminar flow conditions compared to the static culture. Apoptosis marker transcription factor Jun (C-Jun) mRNA expression increased in both flow conditions. Apoptosis marker C/EBP homologous protein (CHOP) mRNA levels increased significantly in oscillatory flow, with no difference in laminar flow. Endothelial nitric oxide synthase (eNOS) mRNA expression was significantly decreased in cells exposed to oscillatory flow, whereas there was no change in laminar flow. Endothelin-1 (ET-1) mRNA expression levels dropped significantly by 0.5- and 0.8-fold in cells exposed to oscillatory and laminar flow, respectively. ECs subjected to oscillatory flow exhibited a significant increase in ROS at both 4 and 24 h compared to the control and laminar flow. Laminar flow-treated cells exhibited a ROS generation pattern similar to that of static culture, but at a significantly lower level. Overall, by exposing ECs to disturbed and normal flows with varying shear stresses, significant changes in gene expression related to inflammation, endothelial function, and oxidative stress were observed. In this study, we present a practical, optimized system as an in vitro model that can be employed to investigate flow-associated diseases, such as atherosclerosis and aortic aneurysm, thereby supporting the understanding of the underlying molecular mechanisms. Full article

A comprehensive understanding of gene-environment interactions is essential for maintaining human cardiac health, and deficiency in the key parkin gene exacerbates cardiac injury. Per- and polyfluoroalkyl substances (PFAS) exposure has been determined cardiotoxicity from the epidemiological perspective but the potential remained unclear. Here, we investigated the co-effects on cardiac pathological structure and function of an emerging PFAS, 6:2 chlorinated polyfluorinated ether sulfonate acid (F-53B), on male parkin^−/− mice at dose of 3 and 3000 μg/kg for 60 d. Mechanism was focused on the activity, phosphorylation of endothelial nitric oxide synthase (eNOS), and the content of nitric oxide (NO), vital vascular function regulating molecule. F-53B significantly increased cardiac fibrosis to 1.58- and 2.80-fold, and cardiac troponin T (cTNT) to 1.17- and 1.32-fold compared with control group, at dose of 3 and 3000 μg/kg, respectively, indicating F-53B can inhibit the normal activities of the heart and cause functional disorders. Content and phosphorylation of eNOS significantly decreased to 0.68-, 0.67-fold, and to 0.65-, 0.54-fold compared with control group, respectively. The subsequent content of NO level was also significantly decreased to 0.47- and 0.33-fold, respectively, indicating that significant co-effects of parkin deficiency and F-53B exposure on cardiac function and structural changes via eNOS/NO signalling. Our work underscores the importance of assessing cardiac risk associated with PFAS at environmentally relevant doses, especially considering environmental exposure and gene co-interaction from the perspective of F-53B and parkin gene. Full article

Background: Nitric oxide (NO)-related biomarkers, including asymmetric dimethylarginine (ADMA), nitric oxide (NO), and endothelial nitric oxide synthase (eNOS), may play a role in the pathophysiology and clinical progression of chronic obstructive pulmonary disease (COPD). This study aimed to investigate their diagnostic value in stable COPD and acute exacerbation. Methods: A total of 150 participants (76 females, 74 males; mean age 53.82 ± 7.06 years) were enrolled and equally distributed into control, stable COPD, and acute exacerbation groups (n = 50 each). Demographic, clinical, and laboratory parameters were compared across groups. Serum ADMA, NO, and eNOS levels were analyzed, and correlations with clinical findings were evaluated. ROC analysis was performed to determine the diagnostic performance of the biomarkers. Results: Serum ADMA levels were significantly higher in COPD patients, particularly in the acute exacerbation group (p < 0.05 for all comparisons). In contrast, NO and eNOS levels were significantly lower in COPD groups compared to controls (p < 0.05 for all comparisons). ADMA showed strong negative correlations with FEV₁, FEV₁/FVC, PaO₂, and SaO₂, whereas NO and eNOS showed positive correlations with the same parameters (all p < 0.01). For predicting acute exacerbation, an ADMA cut-off of 1.36 yielded high diagnostic accuracy (AUC = 0.983; sensitivity 86.0%; specificity 96.0%). eNOS also demonstrated predictive value (AUC = 0.823). For stable COPD, NO at a cut-off of 14.91 showed excellent diagnostic performance (AUC = 0.921). Conclusions: NO-related biomarkers, particularly ADMA and NO, may serve as reliable indicators for differentiating between stable COPD and acute exacerbation. Elevated ADMA and reduced NO and eNOS levels were closely associated with impaired lung function and oxygenation parameters. These findings suggest potential clinical utility of these biomarkers in COPD monitoring and management. Full article

In left ventricular hypertrophy (LVH), the combined external administration of hydrogen sulfide (H₂S) and nitric oxide (NO) has been shown to reverse LVH by activating the endothelial nitric oxide synthase pathway (eNOS/NO), independent of the cystathionine γ-lyase (CSE/H₂S) pathway. Individually, both H₂S and NO have also been reported to significantly improve RCBP, restore renal excretory performance, and enhance α-adrenergic receptor responsiveness in rats. The induction of LVH was performed over a period of two weeks using drinking water with caffeine and isoprenaline. Five weeks later, the rats were fed with L-arginine (1.25 g/L) as a nitrogen oxide donor. Vascular reactions to methoxamine, phenylephrine, and noradrenaline were assessed in presences and absence of 5-methylurapidil (5-MeU), BMY7378, and chloroethylclonidine (CeC) and α1-adrenoceptor antagonists. In both the Control WKY and LVH-WKY groups, combined H₂S+NO therapy significantly (p < 0.05) upregulated the renal mRNA of CSE and eNOS when compared with untreated LVH rats. The treatment also markedly increased RCBP in LVH-H₂S+NO rats relative to LVH controls. Furthermore, H₂S+NO administration enhanced the activity of α_1A, α_1B, and α_1D adrenergic receptors in mediating renal vasoconstriction. Even under receptor blockade with high doses (HDs) of 5-MeU, CeC, and BMY 7378, renal vasoconstriction responses to adrenergic agonists like NA, PE, and ME in the LVH-H₂S+NO group remained comparable to those observed in the counterpart Control-H₂S+NO group. The findings of current study suggest that simultaneous exogenous administration of H₂S and NO donors improve renal cortical blood flow, support renal function, and augment α_1A, α_1B, and α_1D adrenergic receptor responsiveness to adrenergic agonists like NA, PE, and ME in LVH rats. This effect appears to rely primarily on the eNOS/NO pathway, with partial contribution from the CSE/H₂S pathway. Full article

Cerebral vasospasm (CVS) following a subarachnoid hemorrhage (SAH) is a critical complication driven by imbalances between vasodilators and vasoconstrictors. This review explores the bidirectional interplay between nitric oxide (NO) and endothelin-1 (ET-1) in CVS pathogenesis. NO, a potent vasodilator mainly produced by endothelial and neuronal nitric oxide synthase (eNOS/nNOS) under normal physiological conditions, is scavenged early after SAH by hemoglobin derivatives, leading to microcirculatory dysfunction, pericyte constriction, and impaired neurovascular coupling. Conversely, ET-1 exacerbates vasoconstriction by suppressing NO synthesis via ROS-dependent eNOS uncoupling and Rho-kinase activation. The NO/ET-1 axis further influences delayed cerebral ischemia (DCI) through mechanisms like 20-HETE-mediated cGMP suppression and oxidative stress. Emerging therapies—including NO donors, NOS gene therapy, and ET-1 receptor antagonists—aim to restore this balance. Understanding these pathways offers translational potential for mitigating CVS and improving outcomes post-SAH. Full article

Background/Objectives: Enhancing endothelial nitric oxide (NO) bioavailability through natural products may provide a promising strategy for the prevention and management of hypertension. This study investigated the phytochemical composition of ethanolic lotus (Nelumbo nucifera) seed extract (LSE), its vasorelaxant mechanisms, effects on endothelial NO production, and antihypertensive activity. Methods: LSE was characterized via LC-ESI-QTOF-MS using accurate mass data and fragmentation patterns. Vasorelaxant effects were evaluated in isolated rat aortas, and the underlying mechanisms were explored using pharmacological inhibitors. NO production was assessed in human endothelial EA.hy926 cells. Hypotensive activity was examined in normotensive rats following intravenous administration of LSE (10, 30, and 100 mg/kg). Molecular docking was performed to analyze interactions between LSE bioactive compounds and endothelial nitric oxide synthase (eNOS). Results: LC-ESI-QTOF-MS analysis identified 114 compounds, including primary and secondary metabolites. LSE induced vasorelaxation in endothelium-intact aortas, which was reduced by endothelium removal (p < 0.001) and by L-NAME (p < 0.001). LSE also inhibited receptor-operated, Ca²⁺ channel-mediated vasoconstriction (p < 0.05). In vivo, LSE decreased blood pressure in a dose-dependent manner. In EA.hy926 cells, LSE (750 and 1000 µg/mL) increased NO production, an effect attenuated by L-NAME. Molecular docking showed that LSE alkaloids, including nelumborine, nelumboferine, neferine, and isoliensinine had strong affinities for binding with eNOS at the tetrahydrobiopterin (BH4) binding site. Nelumborine exhibited the highest affinity, suggesting its potential as an eNOS modulator. Conclusions: LSE promotes vasorelaxation through the stimulation of endothelium-derived NO release and Ca²⁺ influx inhibition, contributing to blood pressure reduction. These findings support LSE as a potential natural antihypertensive supplement. Full article

Background/Objectives: The rapid progression of stroke often results in irreversible brain damage and poor outcomes when treatment is delayed. Prophylactic administration of FAD012 (3,5-dimethyl-4-hydroxycinnamic acid), a synthetic derivative of ferulic acid (FA), has demonstrated cerebroprotective effects in ischemic models through antioxidant and endothelial protective mechanisms. This study investigated the effects of FAD012 on cerebral infarction and blood–brain barrier (BBB) integrity using a photothrombotic stroke model in rats. Methods: Male Sprague Dawley rats received a single intraperitoneal injection of FAD012 or FA (100 or 300 mg/kg) 60 min prior to stroke induction. Under isoflurane anesthesia, the middle cerebral artery was exposed, and stroke was induced by intravenous administration of Rose Bengal followed by green laser irradiation. Cerebral blood flow (CBF) was monitored by laser Doppler flowmetry. BBB disruption was evaluated by Evans Blue extravasation and immunohistochemistry for tight junction (TJ) proteins. Results: Control rats exhibited extensive infarction, BBB disruption, and reduced expression of claudin-5, occludin, and ZO-1, along with fragmented collagen IV. In contrast, FAD012 (300 mg/kg) significantly attenuated CBF reduction, reduced infarct size, preserved BBB integrity, and maintained TJ protein expression, with greater efficacy than an equivalent dose of FA. FAD012 also preserved the expression and phosphorylation of endothelial nitric oxide synthase (eNOS), a key marker of vascular integrity. The CBF-preserving effect of FAD012 was completely abolished by N^G-nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthase inhibitor. Conclusions: These findings suggest that FAD012 protects endothelial function, thereby contributing to the maintenance of CBF and BBB integrity, supporting its potential as a prophylactic therapeutic agent for ischemic stroke. Full article

Endothelial hyperpermeability is a hallmark of diverse inflammatory and vascular pathologies, including sepsis, acute respiratory distress syndrome (ARDS), ischemia–reperfusion injury, and atherosclerosis. Traditionally considered a passive return to baseline following stimulus withdrawal, barrier recovery is now recognized as an active, endothelial-driven process. Earlier work identified individual components of this restorative phase, such as cyclic adenosine monophosphate (cAMP)/exchange protein directly activated by cAMP 1 (Epac1) signaling, Rap1/Rac1 activation, vasodilator-stimulated phosphoprotein (VASP) phosphorylation, and targeted cytoskeletal remodeling, as well as kinase pathways involving PKA, PKG, and Src. However, these were often regarded as discrete events lacking a unifying framework. Recent integrative analyses, combining mechanistic insights from multiple groups, reveal that nitric oxide (NO) generated early during hyperpermeability can initiate a delayed cAMP/Epac1 cascade. This axis coordinates Rap1/Rac1-mediated cortical actin polymerization, VASP-driven junctional anchoring, retro-translocation of endothelial nitric oxide synthase (eNOS) to caveolar domains, PP2A-dependent suppression of actomyosin tension, and Krüppel-like factor 2 (KLF2)-driven transcriptional programs that sustain endothelial quiescence. Together, these pathways form a temporally orchestrated, multi-tiered “inactivation” program capable of restoring barrier integrity even in the continued presence of inflammatory stimuli. This conceptual shift reframes NO from solely a barrier-disruptive mediator to the initiating trigger of a coordinated, pro-resolution mechanism. The unified framework integrates cytoskeletal dynamics, junctional reassembly, focal adhesion turnover, and redox/transcriptional control, providing multiple potential intervention points. Therapeutically, Epac1 activation, Rap1/Rac1 enhancement, RhoA/ROCK inhibition, PP2A activation, and KLF2 induction represent strategies to accelerate endothelial sealing in acute microvascular syndromes. Moreover, applying these mechanisms to arterial endothelium could limit low-density lipoprotein (LDL) entry and foam cell formation, offering a novel adjunctive approach for atherosclerosis prevention. In this review, we will discuss both the current understanding of endothelial hyperpermeability mechanisms and the emerging pathways of its active inactivation, integrating molecular, structural, and translational perspectives. Full article

Atherosclerosis (AS), the leading cause of cardiovascular disease (CVD), is the thickening and stiffening of arterial walls, mainly of coronary arteries, the aorta, and the internal carotid artery. Blood flow is restricted by the deposit of lipid-rich macrophages (foam cells), calcium, fibrin, and cellular debris into plaques on the inner lining (tunica intima) of arterial walls. Damaged endothelia become inflamed and accumulate macrophages, monocytes, granulocytes, and dendritic cells, which intensifies plaque formation and increases the risk of myocardial infarction (MI) and thrombosis. Many of the anatomical and physiological abnormalities in arterial walls can be linked to colonic bacteria that produce inflammation-inducing metabolites, e.g., succinate, fumarate, fatty acids (FAs), reactive oxygen species (ROS), lipopolysaccharides (LPS), and trimethylamine-N-oxide (TMAO). TMAO triggers platelet formation, inhibits the synthesis of bile acids (BAs), accelerates the formation of aortic lesions, and upregulates the expression of membrane glycoprotein CD36 (also known as platelet glycoprotein 4) on the surface of platelets and epithelial cells. The ability of internal mammary arteries (IMAs) to produce higher levels of apolipoprotein C-III (apo-CIII) and paraoxonase (PON), compared to coronary arteries, prevents plaque buildup. The tunica intima of IMAs is rich in heparin sulfate and endothelial nitric oxide synthase (eNOS). Increased production of NO relaxes VSMCs and suppresses GTP cyclohydrolase (GTPCH), which lowers blood pressure. Higher levels of prostacyclin (PG12) produced by IMAs inhibit platelet aggregation. IMAs are structurally different from coronary arteries by having a thinner, non-fenestrated, tunica intima without a prominent internal elastic lamina. These characteristics render IMAs ideal conduits in coronary artery bypass graft (CABG) surgery. This review provides information that may explain why IMAs are less affected by inflammatory reactions and more resilient to plaque formation. Full article

Hydrogen sulfide (H₂S), nitric oxide (NO), and carbon monoxide (CO) are now recognized as key gasotranmitters that regulate vascular function, contributing to vasodilation, angiogenesis, inflammation control, and oxidative balance. Initially regarded as toxic gases, they are produced on demand by specific enzymes, including cystathionine γ-lyase (CSE), endothelial nitric oxide synthase (eNOS), and heme oxygenase-1 (HO-1). Their activity is tightly controlled by redox-sensitive pathways. Reactive oxygen species (ROS), particularly superoxide and hydrogen peroxide, modulate gasotransmitter biosynthesis at the transcriptional and post-translational levels. Moreover, ROS affect gasotransmitter availability through oxidative modifications, including thiol persulfidation, nitrosative signaling, and carbonylation. This redox regulation ensures a tightly coordinated response to environmental and metabolic cues within the vascular system. This review synthesizes the current understanding of redox–gasotransmitter interactions, highlighting how ROS modulate the vascular roles of H₂S, NO, and CO. Understanding these interactions provides critical insights into the pathogenesis of cardiovascular diseases and offers potential redox-targeted therapies. Full article