Mineralocorticoid receptors contribute to ethanol-induced vascular hypercontractility through reactive oxygen species generation and up-regulation of cyclooxygenase 2

Ethanol-induced dysfunction of the mesenteric perivascular adipose tissue is driven by mineralocorticoid receptors

The renin-angiotensin-aldosterone system (RAAS) is critical in ethanol-induced vascular dysfunction. Mineralocorticoid receptors (MR) trigger ethanol-induced vascular hypercontractility through pro-oxidative and pro-inflammatory effects. However, the contribution of MR to ethanol-induced perivascular adipose tissue (PVAT) dysfunction is unknown. Appreciating the importance of MR to PVAT dysfunction in distinctive pathological conditions, we investigated whether MR would play a role in ethanol-induced PVAT dysfunction. With this purpose, male Wistar Hannover rats were treated with ethanol 20% (in volume ratio) and/or potassium canrenoate [a MR antagonist (MRA); 30 mg/kg/day, gavage] for 5 weeks. Ethanol increased the circulating levels of aldosterone and impaired acetylcholine-induced relaxation of mesenteric arteries with, but not without PVAT. Antagonism of MR prevented ethanol-induced impairment in acetylcholine relaxation as well as the reduction of leptin levels and reactive oxygen species (ROS) overproduction in the mesenteric PVAT (mPVAT) from ethanol-treated rats. Ethanol promoted neutrophil accumulation and augmented the concentration of tumor necrosis factor (TNF)-α in the mPVAT and these responses were prevented by the MRA. Functional assays showed that tiron [a scavenger of superoxide (O2•-)] and etanercept (an antibody anti-TNF-α) failed to reverse the impairment of acetylcholine-induced relaxation promoted by ethanol. In mesenteric arteries, antagonism of MR prevented ROS generation, lipoperoxidation, and increased TNF-α levels induced by ethanol. In conclusion, our findings suggest that MR is involved in ethanol-induced dysfunction of mPVAT. This study enhances our understanding of how ethanol exerts harmful effects on the cardiovascular system, highlighting PVAT as a target for these detrimental effects.

Beclin-1-dependent autophagy protects perivascular adipose tissue function from hyperaldosteronism effects

Hyperaldosteronism (HA), characterized by excessive production of aldosterone (Aldo), contributes to cardiovascular damage and perivascular adipose tissue (PVAT) dysfunction. Previous studies have shown that Aldo can impair autophagy in various tissues. However, it remains unclear whether this impairment occurs specifically in PVAT and whether it involves disruption of autophagic flux through Beclin-1 (BCN1), a key regulator of autophagosome formation and maturation. We hypothesize that BCN1-dependent autophagy plays a protective role in PVAT by limiting inflammation and preserving its anticontractile function in the context of HA. Male and female C57BL/6J [wild type (WT)] and BCN1 knock-in mice, aged 10-12 wk, underwent 14-day aldosterone infusion (600 µg/kg/day) using an osmotic minipump. Vascular function was assessed in PVAT-intact thoracic aortae, and blood pressure was monitored via radiotelemetry. HA disrupted PVAT autophagic flux, leading to the accumulation of LC3II/I and p62 proteins and reduced BCN1 expression/activity. In WT mice, PVAT exhibited an anticontractile effect, which was abolished by HA. In contrast, BCN1-knock-in mice were protected from this loss of PVAT function. HA also induced oxidative stress and inflammation in PVAT, as evidenced by increased reactive oxygen species generation and elevated mRNA levels of TNF-α, IL-6, IL-1β, and IL-17. These proinflammatory and prooxidative changes were not observed in BCN1-knock-in mice, indicating preserved PVAT homeostasis. Furthermore, pharmacological induction of autophagy via spermidine and activation of BCN1 with TB peptide improved PVAT function in HA-treated WT mice. Finally, BCN1-knock-in mice exhibited partial protection against HA-induced hypertension, highlighting the systemic vascular benefits of enhanced autophagic flux. In summary, our findings demonstrate that the activation of autophagy provides protection against HA-induced PVAT inflammation, dysfunction, and hypertension. Consequently, the activation of BCN1 could serve as a pharmacological strategy to prevent the harmful cardiovascular effects associated with HA.NEW & NOTEWORTHY Elevated aldosterone levels, as seen in primary hyperaldosteronism, obesity, and hypertension, impair autophagic flux in perivascular adipose tissue (PVAT), leading to increased inflammation and loss of anticontractile function. The Beclin-1-dependent autophagic pathway plays a key role in maintaining PVAT homeostasis and vascular tone. Disrupted autophagy contributes to oxidative stress and hypertension. Activating this pathway may offer a novel therapeutic strategy to mitigate aldosterone's harmful vascular effects in hypertension by restoring PVAT function and vascular inflammation.

Dual-color reversible fluorescent carbon dots designed for dynamic monitoring of cellular superoxide anion radicals

The superoxide anion radical (O2˙-) represents the primary reactive oxygen species generated in biological systems. Real-time monitoring of its dynamic fluctuations provides valuable insights into disease progression and enables early diagnosis of hepatic ischemia-reperfusion injury (HIRI). In this work, we developed a novel dual-color fluorescent carbon dot (CD) probe through a one-step hydrothermal synthesis for reversible O2˙- detection. The CDs demonstrated excellent sensitivity, dynamically detecting O2˙- concentrations ranging from 0 to 60 μM with a detection limit of 0.56 μM. The probe exhibited remarkable reversibility, maintaining stable performance through at least three complete oxidation-reduction cycles following glutathione (GSH) treatment. In practical applications, the CDs achieved 95.2-104% recovery rates when detecting O2˙- in serum samples. Cellular imaging experiments confirmed the probe's effectiveness in normal hepatocytes (LO2), showing clear reversible responses to O2˙- fluctuations. Application in a HIRI cell model revealed significant elevation of O2˙- levels and provided new evidence for its role in HIRI-related signaling pathways. This study not only presents an effective dual-color fluorescent probe for dynamic O2˙- monitoring but also establishes a versatile synthetic strategy that could be adapted for imaging other biologically relevant molecules in living cells.

Mineralocorticoid receptor antagonists promote renal immunosenescence

Chronic kidney disease (CKD) is often associated with chronic inflammation, influenced by the activation of mineralocorticoid receptors (MR). This review focuses on changes in immune cells and explores the important role that MR antagonists (MRAs), especially the new nonsteroidal MRA, finerenone, play in alleviating renal and cardiac injury by affecting the transformation of stimulated immune cells. We found that MR can promote the transformation of macrophages to M1 pro-inflammatory phenotype through IL-14 receptor and mitogen-activated protein kinase (MAPK)-JNK. MR also activates helper T cells and reduces the generation of regulatory T cells by promoting the interaction between nuclear factor and activator protein-1, increasing the secretion of IL-2 and IL-18, increasing the expression of CD38 and CD69, especially the IL-17/IL-23 axis. The above immune system changes jointly mediate inflammation leading to kidney damage and fibrosis. In addition, we propose that the NLRP3 inflammasome is associated with macrophage imbalance. Preclinical studies indicate that finerenone effectively reduces inflammation and prevents structural kidney damage without significant systemic blood pressure changes. These data will provide some ideas for further research in the field of immune mechanisms in future, and drug research targeting specific targets and channels may also become a new type of diagnostic and treatment measure.

Mineralocorticoid receptor antagonism partially prevents dysfunction of T cell maturation in rats chronically treated with ethanol

Ethanol consumption induces thymic atrophy and affects T cell maturation in the thymus. However, the mechanisms underlying such effects still need to be fully understood. We attempted to investigate the role of mineralocorticoid receptors (MR) on ethanol-induced thymic atrophy, T cell maturation dysfunction, and the role of oxidative stress in such responses. Male Wistar Hannover rats were treated with ethanol (20%; in volume ratio) and/or potassium canrenoate, an antagonist of MR (MRA; 30 mg/kg/day, gavage) for five weeks. Blockade of MR prevented ethanol-induced increases in the number of double-positive (CD4+CD8+), CD8+ single-positive (CD4-CD8+), CD4+ single-positive (CD4+CD8-), and Foxp3+CD4+ (Treg) cells in the thymus. Ethanol increased NOX2-derived superoxide (O2•-), lipoperoxidation, and superoxide dismutase (SOD) activity in the thymus. Pretreatment with the MRA fully prevented these responses. Apocynin, an antioxidant, prevented ethanol-induced increases in the number of double-positive and CD8+ single-positive cells but failed to prevent the rise in the number of CD4+ single-positive and Treg cells induced by ethanol. Apocynin, but not the MRA, prevented thymic atrophy induced by ethanol. Our findings provided novel evidence for the participation of MR in thymic dysfunction induced by ethanol consumption. Oxidative stress mediates the increase in double-positive and CD8+ single-positive cells in response to MR activation, while positive regulation of CD4+ single-positive and Treg cells is independent of oxidative stress. Oxidative stress is a significant mechanism of thymic atrophy associated with ethanol consumption, but this response is independent of MR activation.

Nebivolol prevents redox imbalance and attenuates bladder dysfunction induced by cyclophosphamide in mice

Cyclophosphamide (CYP) is combined with cytoprotective agents to minimize its toxicity in the bladder, which is mediated by reactive oxygen species (ROS). Using multiple antioxidant mechanisms, nebivolol protects from oxidative stress in distinctive conditions. We hypothesized that nebivolol would attenuate both molecular and functional alterations induced by CYP in the bladder. Male C57BL/6 were pretreated or not with nebivolol (10 mg/kg/day, gavage), which was given 5 days before a single injection of CYP (300 mg/kg; i.p.). Molecular and functional parameters were assessed at 24 h in the bladder. Nebivolol prevented increases in ROS generation and lipoperoxidation as well as reduction of superoxide dismutase activity induced by CYP. Increased voiding frequency, decreased voiding interval, and reduced bladder capacity were found in CYP-treated mice. These responses were prevented by nebivolol. An augmented number of urinary spots and smaller urinary volumes were detected in CYP-injected mice, and nebivolol partially prevented these responses. The reduction of ROS levels is the primary mechanism by which nebivolol attenuates the deleterious effects of CYP in the bladder. The association of nebivolol with other cytoprotective agents could be an option to prevent CYP-associated oxidative damage to the bladder during chemotherapy.

Resistance artery vasodilator pathways involved in the antihypertensive effects of cocoa shell extract in rats exposed to fetal undernutrition

Fetal undernutrition establishes the foundations for hypertension development, with oxidative stress being a key hallmark. A growing interest in nutraceuticals for treating hypertension and environmental waste concerns prompted the present study aiming to evaluate whether supplementation with a polyphenol enriched extract from cocoa shell (CSE), a by-product from the chocolate industry with antioxidant properties, reduces hypertension of developmental origin, thus improving mesenteric resistance artery (MRA) vasodilatation. Adult male and female offspring from rats exposed to 50% food restriction from mid-gestation (maternal undernutrition, MUN) and controls were used. Supplementation was given through a gelatine (vehicle, VEH) or containing CSE (250 mg kg-1 day-1) 5 days week-1 for 3 weeks. Systolic blood pressure (SBP) was assessed by tail-cuff plethysmography. MRA function was studied by wire myography, and superoxide anion and nitric oxide were investigated by fluorescent indicators and confocal microscopy. Compared to control-VEH, MUN-VEH males showed significantly higher SBP, reduced MRA as well as relaxation to ACh, sodium nitroprusside and the AMPK agonist 5-aminoimidazole-4-carboxamide riboside, but not to isoproterenol. In MUN males, endothelial endothelium-derived hyperpolarizing factor and nitric oxide were unaltered, but MRA released a vasoconstrictor prostanoid and produced higher levels of superoxide anion. CSE normalized blood pressure and improved all above-mentioned MRA alterations in MUN males without an effect on control counterparts, except the reduction of superoxide anion. MUN-VEH females were normotensive and only showed a tendency towards larger superoxide anion production, which was abolished by CSE. CSE supplementation reduces SBP improving endothelium-dependent and independent MRA vasodilatation, related to local superoxide anion reduction, being a potential nutraceutical ingredient to counteract hypertension, in addition to contributing to the circular economy. KEY POINTS: Fetal undernutrition induces hypertension in males associated with deficient resistance artery vasodilatation, being normalized by cocoa shell extract (CSE). Release of a cyclooxygenase-derived contractile factor is the main endothelial alteration, which is abolished by CSE. AMPK and soluble guanylyl cyclase-mediated relaxation are also reduced in smooth muscle cells from maternal undernutrition resistance arteries, being improved by CSE. Vascular oxidative damage caused by excess superoxide anion generation can account for impaired vasodilatation, which is improved by CSE. The capacity of CSE to improve relaxation is probably related to its antioxidant bioactive factors, and thus cocoa shell is a potential food by-product to treat hypertension.

Efficacy and Safety of Suxiao Jiuxin Pills in the Treatment of Chronic Coronary Syndrome with Intolerance to Adverse Effects of Long-acting Nitrates: A Multicenter, Randomized, Double-blind, Placebo-controlled Study

BACKGROUND

This study aims to investigate the short-term effects and safety of adjunct Suxiao Jiuxin Pills (SJPs) on conventional therapy in chronic coronary syndrome (CCS) patients who are intolerant to the adverse effects of long-acting nitrates.

METHODS

This was a multicenter, randomized, double-blind, placebo-controlled trial. A total of 174 CCS participants from eight clinical study centers in China were included in the modified intention-to-treat analyses. Participants with CCS and intolerance to the adverse effects of long-acting nitrates were recruited and randomized to either the SJPs or the placebo group for a duration of 4 weeks.

RESULTS

Compared to the placebo group, the SJPs group showed a significant improvement in the efficacy rate after 4 weeks (OR = 2.43, 95% CI = 1.32 to 4.47, P = 0.004). Besides, individuals without a history of alcohol consumption showed a greater improvement in the SAQ summary score compared to those with a history of alcohol consumption.

CONCLUSION

Adjunctive SJPs enhance the effectiveness of short-term conventional anti-angina treatment for patients with CCS who experience intolerance to long-acting nitrates, without significant adverse effects during application.

TRIAL REGISTRATION

Chinese Clinical Trials Registry Platform, ChiCTR2100050066. Registered 16 August 2021, https://www.chictr.org.cn/showproj.html?proj=131470 .

Alcohol consumption may be a risk factor for cerebrovascular stenosis in acute ischemic stroke and transient ischemic attack

BACKGROUND

Atherosclerosis are well established risk factors for ischemic stroke, however the association between alcohol consumption and atherosclerosis is controversial. This study aims to explore the potential correlation between alcohol consumption and cerebral stenosis in patients with acute ischemic stroke and transient ischemic attack (TIA).

METHODS

Nine hundreds and eighty-eight patients with first acute ischemic stroke attack or TIA were recruited retrospectively. Alcohol consumption was classified into five consumption categories (non-drinkers, occasional drinkers, < 140 g per week [mild drinkers], 140-279 g per week [moderate drinkers], ≥ 280 g per week [heavy drinkers]). Computed tomography angiography (CTA) and digital subtraction angiography (DSA) were utilized to assess the carotid and cerebral artery in all patients. Five-step scale for degree of stenosis was applied: normal (0, 0 points), mild (< 50%, 1 point), moderate (50-69%, 2 points), severe (70-99%, 3 points), and occlusion (100%, 4 points).

RESULTS

The carotid and cerebral artery stenosis scores were positively correlated with moderate alcohol consumption (B = 1.695, P < 0.001). Compared with nondrinkers, moderate alcohol consumption had significant increasing risk of moderate carotid and cerebral artery stenosis (OR = 4.28, 95% CI: 1.47-12.49, P = 0.008) and severe stenosis (OR = 4.24, 95% CI: 1.55-11.64, P = 0.005) and occlusion (OR = 3.87, 95% CI: 1.65-9.06, P = 0.002). Compared with nondrinkers, heavy alcohol consumption patients had significant higher risk of carotid and cerebral artery occlusion (OR = 2.71, 95% CI: 1.36-5.41, P = 0.005).

CONCLUSIONS

Higher alcohol consumption may associate with higher risk and more severity of carotid and cerebrovascular stenosis.

Exercise training and vascular heterogeneity in db/db mice: evidence for regional- and duration-dependent effects

Exercise training (ET) has several health benefits; however, our understanding of regional adaptations to ET is limited. We examined the functional and molecular adaptations to short- and long-term ET in elastic and muscular conduit arteries of db/db mice in relation to changes in cardiovascular risk factors. Diabetic mice and their controls were exercised at moderate intensity for 4 or 8 weeks. The vasodilatory and contractile responses of thoracic aortae and femoral arteries isolated from the same animals were examined. Blood and aortic samples were used to measure hyperglycemia, oxidative stress, inflammation, dyslipidemia, protein expression of SOD isoforms, COX, eNOS, and Akt. Short-term ET improved nitric oxide (NO) mediated vasorelaxation in the aortae and femoral arteries of db/db mice in parallel with increased SOD2 and SOD3 expression, reduced oxidative stress and triglycerides, and independent of weight loss, glycemia, or inflammation. Long-term ET reduced body weight in parallel with reduced systemic inflammation and improved insulin sensitivity along with increased SOD1, Akt, and eNOS expression and improved NO vasorelaxation. Exercise did not restore NOS- and COX-independent vasodilatation in femoral arteries, nor did it mitigate the hypercontractility in the aortae of db/db mice; rather ET transiently increased contractility in association with upregulated COX-2. Long-term ET differentially affected the aortae and femoral arteries contractile responses. ET improved NO-mediated vasodilation in both arteries likely due to collective systemic effects. ET did not mitigate all diabetes-induced vasculopathies. Optimization of the ET regimen can help develop comprehensive management of type 2 diabetes.

Vascular injury associated with ethanol intake is driven by AT1 receptor and mitochondrial dysfunction

BACKGROUND

Renin-angiotensin (Ang II)-aldosterone system (RAAS) is crucial for the cardiovascular risk associated with excessive ethanol consumption. Disturbs in mitochondria have been implicated in multiple cardiovascular diseases. However, if mitochondria dysfunction contributes to ethanol-induced vascular dysfunction is still unknown. We investigated whether ethanol leads to vascular dysfunction via RAAS activation, mitochondria dysfunction, and mitochondrial reactive oxygen species (mtROS).

METHODS

Male C57/BL6J or mt-keima mice (6-8-weeks old) were treated with ethanol (20% vol./vol.) for 12 weeks with or without Losartan (10 mg/kg/day).

RESULTS

Ethanol induced aortic hypercontractility in an endothelium-dependent manner. PGC1α (a marker of biogenesis), Mfn2, (an essential protein for mitochondria fusion), as well as Pink-1 and Parkin (markers of mitophagy), were reduced in aortas from ethanol-treated mice. Disturb in mitophagy flux was further confirmed in arteries from mt-keima mice. Additionally, ethanol increased mtROS and reduced SOD2 expression. Strikingly, losartan prevented vascular hypercontractility, mitochondrial dysfunction, mtROS, and restored SOD2 expression. Both MnTMPyP (SOD2 mimetic) and CCCP (a mitochondrial uncoupler) reverted ethanol-induced vascular dysfunction. Moreover, L-NAME (NOS inhibitor) and EUK 134 (superoxide dismutase/catalase mimetic) did not affect vascular response in ethanol group, suggesting that ethanol reduces aortic nitric oxide (NO) and H2O2 bioavailability. These responses were prevented by losartan.

CONCLUSION

AT1 receptor modulates ethanol-induced vascular hypercontractility by promoting mitochondrial dysfunction, mtROS, and reduction of NO and H2O2 bioavailability. Our findings shed a new light in our understanding of ethanol-induced vascular toxicity and open perspectives of new therapeutic approaches for patients with disorder associated with abusive ethanol drinking.

Reactive Oxygen Species Are Central Mediators of Vascular Dysfunction and Hypertension Induced by Ethanol Consumption

Consumption of high amounts of ethanol is a risk factor for development of cardiovascular diseases such as arterial hypertension. The hypertensive state induced by ethanol is a complex multi-factorial event, and oxidative stress is a pathophysiological hallmark of vascular dysfunction associated with ethanol consumption. Increasing levels of reactive oxygen species (ROS) in the vasculature trigger important processes underlying vascular injury, including accumulation of intracellular Ca2+ ions, reduced bioavailability of nitric oxide (NO), activation of mitogen-activated protein kinases (MAPKs), endothelial dysfunction, and loss of the anticontractile effect of perivascular adipose tissue (PVAT). The enzyme nicotinamide adenine dinucleotide phosphate (NADPH) oxidase plays a central role in vascular ROS generation in response to ethanol. Activation of the renin-angiotensin-aldosterone system (RAAS) is an upstream mechanism which contributes to NADPH oxidase stimulation, overproduction of ROS, and vascular dysfunction. This review discusses the mechanisms of vascular dysfunction induced by ethanol, detailing the contribution of ROS to these processes. Data examining the association between neuroendocrine changes and vascular oxidative stress induced by ethanol are also reviewed and discussed. These issues are of paramount interest to public health as ethanol contributes to blood pressure elevation in the general population, and it is linked to cardiovascular conditions and diseases.