Remote Effects of Transplanted Perivascular Adipose Tissue on Endothelial Function and Atherosclerosis

Perivascular adipocyte size is related to the lipid profile and inflammatory changes in a healthy population

Inflammatory changes in perivascular adipose tissue are associated with atherosclerotic lesions in the adjacent artery and can also be used as a marker in patient workup. While adipocyte size is known to be closely related to adipose tissue dysfunction and inflammation, it has not been widely studied in perivascular adipose tissue obtained from healthy human subjects without clinical atherosclerosis. In this cross-sectional study, we addressed this issue by measuring adipocyte size and defining its relationship to cardiovascular risk factors in a healthy cohort of living kidney donors. The presence of cardiovascular risk factors was established by a standardized questionnaire, clinical measurements and body composition analyses. Adipocyte size was measured in the perivascular depot. The proportions of various macrophage subtypes were determined by flow cytometry. To confirm the results, the proportion of CD68  +  macrophages was additionally assessed by immunohistochemistry. A correlation and principal component analyses were performed to explore associations. Adipocyte size in perivascular adipose tissue correlated with markers of lipid metabolism, inflammation, and glucose metabolism. Further, the positive correlation with the pro-inflammatory subpopulation of macrophages suggests a strong local effect of perivascular adipose tissue. Perivascular adipocyte size was associated with cardiovascular risk factors and markers of inflammation in a healthy cohort of living kidney donors. This further supports the local role of adipose tissue dysfunction and inflammation in early atherosclerosis development and detection.

Macrophage foam cell-derived mediator promotes spontaneous fat lipolysis in atherosclerosis models

Ectopic lipid accumulation in macrophages is responsible for the formation of macrophage foam cells (MFCs) which are involved in the crosstalk with the perivascular adipose tissue (PVAT) of the vascular wall that plays a pivotal role in the progression of atherosclerosis. However, the interrelationship between MFCs and PVAT implementing adipocyte dysfunction during atherosclerosis has not yet been established. We hypothesized that MFC-secreted mediator(s) is causally linked with PVAT dysfunction and the succession of atherosclerosis. To test this hypothesis, MFCs were cocultured with adipocytes, or the conditional media of MFCs (MFC-CM) were exposed to adipocytes and found a significant induction of fat lipolysis in adipocytes. The molecular filtration followed by the high-performance liquid chromatography (HPLC) fractionation and liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) analysis of MFC-CM revealed a novel mediator fetuin-A (FetA) that significantly augments toll-like receptor 4 (TLR4)-dependent fat lipolysis in adipocytes. Mechanistically, MFC-derived FetA markedly increased TLR4-dependent c-Jun N-terminal kinases (JNK)/extracellular signal-regulated kinases (ERK) activation that causes spontaneous fat lipolysis implementing adipocyte dysfunction. Thus, the present study provides the first evidence of MFC-derived FetA that induces adipocyte dysfunction by the stimulation of spontaneous fat lipolysis. Therefore, targeting the crosstalk between MFCs and adipocytes could be a newer approach to counter the progression of atherosclerosis.

Perivascular Adipose Tissue and Perivascular Adipose Tissue-Derived Extracellular Vesicles: New Insights in Vascular Disease

Perivascular adipose tissue (PVAT) is a special deposit of fat tissue surrounding the vasculature. Previous studies suggest that PVAT modulates the vasculature function in physiological conditions and is implicated in the pathogenesis of vascular diseases. Understanding how PVAT influences vasculature function and vascular disease progression is important. Extracellular vesicles (EVs) are novel mediators of intercellular communication. EVs encapsulate molecular cargo such as proteins, lipids, and nucleic acids. EVs can influence cellular functions by transferring the carried bioactive molecules. Emerging evidence indicates that PVAT-derived EVs play an important role in vascular functions under health and disease conditions. This review will focus on the roles of PVAT and PVAT-EVs in obesity, diabetic, and metabolic syndrome-related vascular diseases, offering novel insights into therapeutic targets for vascular diseases.

Interruption of perivascular and perirenal adipose tissue thromboinflammation rescues prediabetic cardioautonomic and renovascular deterioration

The cardiovascular and renovascular complications of metabolic deterioration are associated with localized adipose tissue dysfunction. We have previously demonstrated that metabolic impairment delineated the heightened vulnerability of both the perivascular (PVAT) and perirenal adipose tissue (PRAT) depots to hypoxia and inflammation, predisposing to cardioautonomic, vascular and renal deterioration. Interventions either addressing underlying metabolic disturbances or halting adipose tissue dysfunction rescued the observed pathological and functional manifestations. Several lines of evidence implicate adipose tissue thromboinflammation, which entails the activation of the proinflammatory properties of the blood clotting cascade, in the pathogenesis of metabolic and cardiovascular diseases. Despite offering valuable tools to interrupt the thromboinflammatory cycle, there exists a significant knowledge gap regarding the potential pleiotropic effects of anticoagulant drugs on adipose inflammation and cardiovascular function. As such, a systemic investigation of the consequences of PVAT and PRAT thromboinflammation and its interruption in the context of metabolic disease has not been attempted. Here, using an established prediabetic rat model, we demonstrate that metabolic disturbances are associated with PVAT and PRAT thromboinflammation in addition to cardioautonomic, vascular and renal functional decline. Administration of rivaroxaban, a FXa inhibitor, reduced PVAT and PRAT thromboinflammation and ameliorated the cardioautonomic, vascular and renal deterioration associated with prediabetes. Our present work outlines the involvement of PVAT and PRAT thromboinflammation during early metabolic derangement and offers novel perspectives into targeting adipose tissue thrombo-inflammatory pathways for the management its complications in future translational efforts.

Expression of secreted frizzled-related proteins in acute aortic dissection patients and the effects on prognosis

Background

Secreted frizzled-related proteins (SFRPs) were reported to be involved in cardiovascular diseases. This study aimed to observe plasma SFRP levels in acute aortic dissection (AD) patients and the effects of SFRP expression on AD prognosis.

Methods

Plasma levels of SFRP1, SFRP2, SFRP3, SFRP4, and SFRP5 were measured in AD patients and non-AD (NAD) patients. The end-point events information of AD patients, including all-cause death and various clinical complications due to aortic dissection, was collected during a 36-month follow-up.

Results

The SFRP1, SFRP2, SFRP3, and SFRP4 levels were increased in AD patients compared with those in NAD patients, while the SFRP5 concentrations were decreased. No differences in any of the SFRP levels were observed between the type A group and the type B group. The AD patients with end-point events exhibited higher SFRP1, SFRP2, SFRP3, and SFRP4 concentrations but lower SFRP5 levels than the patients without end-point events. In addition, the AD patients were divided into a high group and a low group based on the median SFRP levels, and Kaplan-Meier analysis revealed that the AD patients with high SFRP1, SFRP2, SFRP4, or SFRP5 levels had a better prognosis than those with low levels. However, the AD patients with high SFRP3 levels exhibited the opposite trends. The binary logistic regression analysis found that SFRP1, SFRP2, SFRP4, and SFRP5 were all negatively correlated with the occurrence of end-point events, while SFRP3 was positively correlated with its occurrence.

Conclusions

SFRP levels are all changed in acute AD, which may affect the prognosis of AD patients. SFRPs may be a target to improve the prognosis of AD.

Thermogenic Modulation of Adipose Depots: A Perspective on Possible Therapeutic Intervention with Early Cardiorenal Complications of Metabolic Impairment

Cardiovascular complications of diabetes and obesity remain a major cause for morbidity and mortality worldwide. Despite significant advances in the pharmacotherapy of metabolic disease, the available approaches do not prevent or slow the progression of complications. Moreover, a majority of patients present with significant vascular involvement at early stages of dysfunction prior to overt metabolic changes. The lack of disease-modifying therapies affects millions of patients globally, causing a massive economic burden due to these complications. Significantly, adipose tissue inflammation was implicated in the pathogenesis of metabolic syndrome, diabetes, and obesity. Specifically, perivascular adipose tissue (PVAT) and perirenal adipose tissue (PRAT) depots influence cardiovascular and renal structure and function. Accumulating evidence implicates localized PVAT/PRAT inflammation as the earliest response to metabolic impairment leading to cardiorenal dysfunction. Increased mitochondrial uncoupling protein 1 (UCP1) expression and function lead to PVAT/PRAT hypoxia and inflammation as well as vascular, cardiac, and renal dysfunction. As UCP1 function remains an undruggable target so far, modulation of the augmented UCP1-mediated PVAT/PRAT thermogenesis constitutes a lucrative target for drug development to mitigate early cardiorenal involvement. This can be achieved either by subtle targeted reduction in UCP-1 expression using innovative proteolysis activating chimeric molecules (PROTACs) or by supplementation with cyclocreatine phosphate, which augments the mitochondrial futile creatine cycling and thus decreases UCP1 activity, enhances the efficiency of oxygen use, and reduces hypoxia. Once developed, these molecules will be first-in-class therapeutic tools to directly interfere with and reverse the earliest pathology underlying cardiac, vascular, and renal dysfunction accompanying the early metabolic deterioration. SIGNIFICANCE STATEMENT: Adipose tissue dysfunction plays a major role in the pathogenesis of metabolic diseases and their complications. Although mitochondrial alterations are common in metabolic impairment, it was only recently shown that the early stages of metabolic challenge involve inflammatory changes in select adipose depots associated with increased uncoupling protein 1 thermogenesis and hypoxia. Manipulating this mode of thermogenesis can help mitigate the early inflammation and the consequent cardiorenal complications.

Associations of metabolic syndrome, its severity with cognitive impairment among hemodialysis patients

BACKGROUND

In the general population, metabolic syndrome (MetS) is associated with increased risk of cognitive impairment, including global and specific cognitive domains. These associations are not well studied in patients undergoing hemodialysis and were the focus of the current investigation.

METHODS

In this multicenter cross-sectional study, 5492 adult hemodialysis patients (3351 men; mean age: 54.4 ± 15.2 years) treated in twenty-two dialysis centers of Guizhou, China were included. The Mini-Mental State Examination (MMSE) was utilized to assess mild cognitive impairment (MCI). MetS was diagnosed with abdominal obesity, hypertension, hyperglycemia, and dyslipidemia. Multivariate logistic and linear regression models were used to examine the associations of MetS, its components, and metabolic scores with the risk of MCI. Restricted cubic spline analyses were performed to explore the dose-response associations.

RESULTS

Hemodialysis patients had a high prevalence of MetS (62.3%) and MCI (34.3%). MetS was positively associated with MCI risk with adjusted ORs of 1.22 [95% confidence interval (CI) 1.08-1.37, P = 0.001]. Compared to no MetS, adjusted ORs for MCI were 2.03 (95% CI 1.04-3.98) for 22.51 (95% CI 1.28-4.90) for 3, 2.35 (95% CI 1.20-4.62) for 4, and 2.94 (95% CI 1.48-5.84) for 5 components. Metabolic syndrome score, cardiometabolic index, and metabolic syndrome severity score were associated with increased risk of MCI. Further analysis showed that MetS was negatively associated with MMSE score, orientation, registration, recall and language (P < 0.05). Significant interaction effect of sex (P for interaction = 0.012) on the MetS-MCI was observed.

CONCLUSION

Metabolic syndrome was associated with MCI in hemodialysis patients in a positive dose-response effect.

Perivascular adipose tissue promotes vascular dysfunction in murine lupus

Introduction

Patients with systemic lupus erythematosus (SLE) are at elevated risk for Q10 cardiovascular disease (CVD) due to accelerated atherosclerosis. Compared to heathy control subjects, lupus patients have higher volumes and densities of thoracic aortic perivascular adipose tissue (PVAT), which independently associates with vascular calcification, a marker of subclinical atherosclerosis. However, the biological and functional role of PVAT in SLE has not been directly investigated.

Methods

Using mouse models of lupus, we studied the phenotype and function of PVAT, and the mechanisms linking PVAT and vascular dysfunction in lupus disease.

Results and discussion

Lupus mice were hypermetabolic and exhibited partial lipodystrophy, with sparing of thoracic aortic PVAT. Using wire myography, we found that mice with active lupus exhibited impaired endothelium-dependent relaxation of thoracic aorta, which was further exacerbated in the presence of thoracic aortic PVAT. Interestingly, PVAT from lupus mice exhibited phenotypic switching, as evidenced by "whitening" and hypertrophy of perivascular adipocytes along with immune cell infiltration, in association with adventitial hyperplasia. In addition, expression of UCP1, a brown/beige adipose marker, was dramatically decreased, while CD45-positive leukocyte infiltration was increased, in PVAT from lupus mice. Furthermore, PVAT from lupus mice exhibited a marked decrease in adipogenic gene expression, concomitant with increased pro-inflammatory adipocytokine and leukocyte marker expression. Taken together, these results suggest that dysfunctional, inflamed PVAT may contribute to vascular disease in lupus.

Greater aortic perivascular adipose tissue density is associated with aging, aortic stiffness, and central blood pressure in humans

Aging results in aortic perivascular adipose tissue (aPVAT)-mediated aortic stiffening in preclinical animal models to promote cardiovascular dysfunction. We hypothesized that greater human aPVAT density will be associated with aging, higher aortic stiffness, and blood pressure (BP). Fourteen apparently healthy adults (6 M/8 F, age range 20-79 yr) were recruited for this study. Aortic stiffness, assessed by carotid-femoral pulse wave velocity (cfPWV), resting aortic BP via pulse wave analysis, and aPVAT and abdominal visceral adipose tissue (VAT) density by computed tomography attenuation were acquired. aPVAT and epididymal (visceral) fat from young (4-6 mo) and old (27-29 mo) mice were used for ex vivo-conditioned media intrinsic mechanical stiffness experiments. Compared with younger adults, older adults had higher cfPWV (8.6 ± 0.4 vs. 6.2 ± 0.6 m/s, P < 0.05) and greater aPVAT attenuation (-80.2 ± 2.0 vs. -95.9 ± 1.5 HU, P < 0.05), but not VAT attenuation (P > 0.05). aPVAT-conditioned media from old mice compared with young mice increased intrinsic mechanical stiffness of the aorta (4,519 ± 510 vs. 2,325 ± 563 kPa, P < 0.05), which was not observed with epididymal fat-conditioned media from old mice (P > 0.05). aPVAT, but not VAT density, was positively associated with age (r = 0.89), cfPWV (r = 0.56), resting augmentation index normalized to heart rate 75 (AIxHR75; r = 0.67), aortic systolic BP (r = 0.58), and aortic pulse pressure (PP; r = 0.59; P < 0.05, all) and were independent of VAT density (P < 0.05, all). These data herein provide evidence for aPVAT as a novel fat depot and therapeutic target to lower aortic stiffness and future cardiovascular disease risk with aging in humans.NEW & NOTEWORTHY Aortic perivascular adipose tissue (aPVAT) promotes age-related aortic stiffening in preclinical animal models, but the relation between aPVAT density and cardiovascular function in adults is unknown. We demonstrate that aPVAT, but not abdominal visceral adipose tissue density, is positively associated with aging, aortic stiffness, and higher resting aortic blood pressure in apparently healthy adults. These findings provide novel evidence for aPVAT as a viable therapeutic target for improving cardiovascular function in humans.

Depot-specific adipose tissue modulation by SGLT2 inhibitors and GLP1 agonists mediates their cardioprotective effects in metabolic disease

Sodium-glucose transporter-2 inhibitors (SGLT-2i) and glucagon-like peptide 1 (GLP-1) receptor agonists are newer antidiabetic drug classes, which were recently shown to decrease cardiovascular (CV) morbidity and mortality in diabetic patients. CV benefits of these drugs could not be directly attributed to their blood glucose lowering capacity possibly implicating a pleotropic effect as a mediator of their impact on cardiovascular disease (CVD). Particularly, preclinical and clinical studies indicate that SGLT-2i(s) and GLP-1 receptor agonists are capable of differentially modulating distinct adipose pools reducing the accumulation of fat in some depots, promoting the healthy expansion of others, and/or enhancing their browning, leading to the suppression of the metabolically induced inflammatory processes. These changes are accompanied with improvements in markers of cardiac structure and injury, coronary and vascular endothelial healing and function, vascular remodeling, as well as reduction of atherogenesis. Here, through a summary of the available evidence, we bring forth our view that the observed CV benefit in response to SGLT-2i or GLP-1 agonists therapy might be driven by their ameliorative impact on adipose tissue inflammation.

Perivascular adipose tissue in autoimmune rheumatic diseases

Perivascular adipose tissue (PVAT) resides at the outermost boundary of the vascular wall, surrounding most conduit blood vessels, except for the cerebral vessels, in humans. A growing body of evidence suggests that inflammation localized within PVAT may contribute to the pathogenesis of cardiovascular disease (CVD). Patients with autoimmune rheumatic diseases (ARDs), e.g., systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), psoriasis, etc., exhibit heightened systemic inflammation and are at increased risk for CVD. Data from clinical studies in patients with ARDs support a linkage between dysfunctional adipose tissue, and PVAT in particular, in disease pathogenesis. Here, we review the data linking PVAT to the pathogenesis of CVD in patients with ARDs, focusing on the role of novel PVAT imaging techniques in defining disease risk and responses to biological therapies.

Obesity and Endothelial Function

Obesity is a major public health problem and is related to increasing rates of cardiovascular morbidity and mortality. Over 1.9 billion adults are overweight or obese worldwide and the prevalence of obesity is increasing. Obesity influences endothelial function through obesity-related complications such as hypertension, dyslipidemia, diabetes, metabolic syndrome, and obstructive sleep apnea syndrome. The excess fat accumulation in obesity causes adipocyte dysfunction and induces oxidative stress, insulin resistance, and inflammation leading to endothelial dysfunction. Several anthropometric indices and imaging modalities that are used to evaluate obesity have demonstrated an association between obesity and endothelial function. In the past few decades, there has been great focus on the mechanisms underlying endothelial dysfunction caused by obesity for the prevention and treatment of cardiovascular events. This review focuses on pathophysiological mechanisms of obesity-induced endothelial dysfunction and therapeutic targets of obesity.

Early metabolic impairment as a contributor to neurodegenerative disease: Mechanisms and potential pharmacological intervention

The metabolic syndrome comprises a family of clinical and laboratory findings, including insulin resistance, hyperglycemia, hypertriglyceridemia, low high-density lipoprotein cholesterol levels, and hypertension, in addition to central obesity. The syndrome confers a high risk of cardiovascular mortality. Indeed, metabolic dysfunction has been shown to cause a direct insult to smooth muscle and endothelial components of the vasculature, which leads to vascular dysfunction and hyperreactivity. This, in turn, causes cerebral vasoconstriction and hypoperfusion, eventually contributing to cognitive deficits. Moreover, the metabolic syndrome disrupts key homeostatic processes in the brain, including apoptosis, autophagy, and neurogenesis. Impairment of such processes in the context of metabolic dysfunction has been implicated in the pathogenesis of neurodegenerative diseases, including Alzheimer, Parkinson, and Huntington diseases. The aim of this review is to elucidate the role that the metabolic syndrome plays in the pathogenesis of the latter disorders, with a focus on the role of perivascular adipose inflammation in the peripheral-to-central transduction of the inflammatory insult. This review delineates common signaling pathways that contribute to these pathologies. Moreover, the role of therapeutic agents aimed at treating the metabolic syndrome, as well as their risk factors that interfere with the aforementioned pathways, are discussed as potential interventions for neurodegenerative diseases.

NOTCH3 as a modulator of vascular disease: a target in elastin deficiency and arterial pathologies

During blood vessel disease, vascular smooth muscle cell (VSMC) expansion and interaction with the matrix trigger changes in gene expression and phenotype. In this issue of the JCI, Dave et al. discover a signaling network that drives VSMC expansion and vascular obstruction caused by elastin insufficiency. Using a combination of gene-targeted mice, tissues and cells from patients with Williams-Beuren syndrome, and targeting of elastin in human VSMCs, the authors identified VSMC-derived NOTCH3 signaling as a critical mediator of aortic hypermuscularization and loss of vascular patency. NOTCH3-specific therapies or therapies that target downstream molecular pathways may provide opportunities to minimize VSMC growth and treat cardiovascular disease with minimal side effects.

Effect of intravenous cell therapy in rats with old myocardial infarction

Mounting evidence shows that cell therapy provides therapeutic benefits in experimental and clinical settings of chronic heart failure. However, direct cardiac delivery of cells via transendocardial injection is logistically complex, expensive, entails risks, and is not amenable to multiple dosing. Intravenous administration would be a more convenient and clinically applicable route for cell therapy. Thus, we determined whether intravenous infusion of three widely used cell types improves left ventricular (LV) function and structure and compared their efficacy. Rats with a 30-day-old myocardial infarction (MI) received intravenous infusion of vehicle (PBS) or 1 of 3 types of cells: bone marrow mesenchymal stromal cells (MSCs), cardiac mesenchymal cells (CMCs), and c-kit-positive cardiac cells (CPCs), at a dose of 12 × 106 cells. Rats were followed for 35 days after treatment to determine LV functional status by serial echocardiography and hemodynamic studies. Blood samples were collected for Hemavet analysis to determine inflammatory cell profile. LV ejection fraction (EF) dropped ≥ 20 points in all hearts at 30 days after MI and deteriorated further at 35-day follow-up in the vehicle-treated group. In contrast, deterioration of EF was halted in rats that received MSCs and attenuated in those that received CMCs or CPCs. None of the 3 types of cells significantly altered scar size, myocardial content of collagen or CD45-positive cells, or Hemavet profile. This study demonstrates that a single intravenous administration of 3 types of cells in rats with chronic ischemic cardiomyopathy is effective in attenuating the progressive deterioration in LV function. The extent of LV functional improvement was greatest with CPCs, intermediate with CMCs, and least with MSCs.

Phosphorus Supplementation Mitigates Perivascular Adipose Inflammation-Induced Cardiovascular Consequences in Early Metabolic Impairment

Background

The complexity of the interaction between metabolic dysfunction and cardiovascular complications has long been recognized to extend beyond simple perturbations of blood glucose levels. Yet, structured interventions targeting the root pathologies are not forthcoming. Growing evidence implicates the inflammatory changes occurring in perivascular adipose tissue (PVAT) as early instigators of cardiovascular deterioration.

Methods and Results

We used a nonobese prediabetic rat model with localized PVAT inflammation induced by hypercaloric diet feeding, which dilutes inorganic phosphorus (Pi) to energy ratio by 50%, to investigate whether Pi supplementation ameliorates the early metabolic impairment. A 12‐week Pi supplementation at concentrations equivalent to and twice as much as that in the control diet was performed. The localized PVAT inflammation was reversed in a dose‐dependent manner. The increased expression of UCP1 (uncoupling protein1), HIF‐1α (hypoxia inducible factor‐1α), and IL‐1β (interleukin‐1β), representing the hallmark of PVAT inflammation in this rat model, were reversed, with normalization of PVAT macrophage polarization. Pi supplementation restored the metabolic efficiency consistent with its putative role as an UCP1 inhibitor. Alongside, parasympathetic autonomic and cerebrovascular dysfunction function observed in the prediabetic model was reversed, together with the mitigation of multiple molecular and histological cardiovascular damage markers. Significantly, a Pi‐deficient control diet neither induced PVAT inflammation nor cardiovascular dysfunction, whereas Pi reinstatement in the diet after a 10‐week exposure to a hypercaloric low‐Pi diet ameliorated the dysfunction.

Conclusions

Our present results propose Pi supplementation as a simple intervention to reverse PVAT inflammation and its early cardiovascular consequences, possibly through the interference with hypercaloric‐induced increase in UCP1 expression/activity.

Urban fine particulate air pollution exposure promotes atherosclerosis in apolipoprotein E-deficient mice by activating perivascular adipose tissue inflammation via the Wnt5a/Ror2 signaling pathway

Urban fine particulate matter (PM_2.5) is a deleterious risk factor in the ambient air and is recognized to exacerbate atherosclerosis. Perivascular adipose tissue (PVAT) secretes a large number of inflammatory cytokines and plays a crucial role in the pathogenic microenvironment of atherogenesis. However, there is a lack of knowledge about the role of PVAT inflammation in the genesis of PM_2.5-related atherosclerosis. The aim of this research was to probe the latent links between PM_2.5 exposure and PVAT inflammation and further discovered the underlying mechanisms of PM_2.5-triggered atherosclerosis pathogenesis. Apolipoprotein E-deficient (ApoE^-/-) mice were exposed to real-world atmospheric PM_2.5 or filtered clean air for three months, the Wnt5a inhibitor Box5 and the Ror2 inhibitor β-Arrestin2 were applied to verify the possible mechanisms. We noticed that the average daily PM_2.5 mass concentration was 84.27 ± 28.84 μg/m³. PM_2.5 inhalation might significantly expedite the deterioration of atherosclerosis, increase the protein and mRNA expressions of MCP-1, IL-6, TNF-α, Wnt5a, and Ror2 in PVAT tissues, upregulate the distributions of IL-6, TNF-α, MCP-1, and leptin in the histological sections of PVAT, promote lipid deposition in the aorta, elevate the plasma levels of leptin, MCP-1, IL-6, TNF-α, LDL-C, TC, and TG, however, decrease the plasma levels of adiponectin and HDL-C, downregulate the distribution of adiponectin. Nevertheless, these effects caused by PM_2.5 exposure were dramatically diminished after the administration of Box5 or β-Arrestin2. This research illuminated that PVAT inflammation was involved in the PM_2.5-induced atherosclerosis process, as well as lipid deposition, which was closely associated with the activation of the Wnt5a/Ror2 signaling pathway.

Carotid Artery Perivascular Adipose Tissue Density Relates to Recanalization and Clinical Outcome After Mechanical Thrombectomy

Background: Perivascular adipose tissue (PVAT) imaging can be used in clinical practice as a surrogate marker of vascular disease. We aimed to analyze the association between the density of carotid artery PVAT and clinical features and outcomes in stroke patients treated with mechanical thrombectomy.

Methods: A total of 183 consecutive patients treated with mechanical thrombectomy due to anterior circulation large vessel occlusion were retrospectively included from January 2016 to May 2021. The density of carotid artery PVAT was evaluated by preoperative computed tomography angiography. Successful arterial recanalization was defined as a modified Thrombolysis in Cerebral Infarction score of 2b-3 on the final angiographic examination. Poor functional outcome was defined as a modified Rankin Scale (mRS) score > 2 at 3 months after stroke. We assessed the independent effect of carotid artery PVAT density on revascularization, functional outcome, and mortality using logistic regression models adjusted for relevant confounders.

Results: Patients with large artery atherosclerotic stroke have higher carotid artery PVAT density than patients with other stroke etiologies (–65.82 ± 12.96 vs. –75.77 ± 13.44, P < 0.001). Higher carotid artery PVAT density was associated with unsuccessful recanalization [adjusted odds ratio (AOR) (95% CI), 2.968 (1.292, 6.819), P = 0.010], and poor outcome [AOR (95% CI), 2.704 (1.610, 4.541), P < 0.001] and mortality [AOR (95% CI), 1.894 (1.040, 3.449), P = 0.037] at 3 months in stroke patients treated with thrombectomy.

Conclusion: Higher carotid artery PVAT density before mechanical thrombectomy is an indicator of worse postprocedural arterial revascularization and a worse functional outcome in acute stroke patients.

Mitochondrial uncoupling protein 1 antagonizes atherosclerosis by blocking NLRP3 inflammasome-dependent interleukin-1β production

Mitochondrial uncoupling protein 1 (UCP1) is the hallmark of brown adipocytes responsible for cold- and diet-induced thermogenesis. Here, we report a previously unidentified role of UCP1 in maintaining vascular health through its anti-inflammatory actions possibly in perivascular adipose tissue. UCP1 deficiency exacerbates dietary obesity-induced endothelial dysfunction, vascular inflammation, and atherogenesis in mice, which was not rectified by reconstitution of UCP1 in interscapular brown adipose tissue. Mechanistically, lack of UCP1 augments mitochondrial membrane potential and mitochondrial superoxide, leading to hyperactivation of the NLRP3-inflammasome and caspase-1–mediated maturation of interleukin-1β (IL-1β). UCP1 deficiency–evoked deterioration of vascular dysfunction and atherogenesis is reversed by IL-1β neutralization or a chemical mitochondrial uncoupler. Furthermore, UCP1 knockin pigs (which lack endogenous UCP1) are refractory to vascular inflammation and coronary atherosclerosis. Thus, UCP1 acts as a gatekeeper to prevent NLRP3 inflammasome activation and IL-1β production in the vasculature, thereby conferring a protective effect against cardiovascular diseases.

Impact of Different Adipose Depots on Cardiovascular Disease

ABSTRACT

Adipose tissue (AT)-derived factors contribute to the regulation of cardiovascular homeostasis, thereby playing an important role in cardiovascular health and disease. In obesity, AT expands and becomes dysfunctional, shifting its secretory profile toward a proinflammatory state associated with deleterious effects on the cardiovascular system. AT in distinct locations (ie, adipose depots) differs in crucial phenotypic variables, including inflammatory and secretory profile, cellular composition, lipolytic activity, and gene expression. Such heterogeneity among different adipose depots may explain contrasting cardiometabolic risks associated with different obesity phenotypes. In this respect, central obesity, defined as the accumulation of AT in the abdominal region, leads to higher risk of cardiometabolic alterations compared with the accumulation of AT in the gluteofemoral region (ie, peripheral obesity). The aim of this review was to provide an updated summary of clinical and experimental evidence supporting the differential roles of different adipose depots in cardiovascular disease and to discuss the molecular basis underlying the differences of adipose depots in the regulation of cardiovascular function.

Different effects of high-fat and high-sucrose diets on the physiology of perivascular adipose tissues of the thoracic and abdominal aorta

Vascular diseases such as atherosclerosis and aneurysms are associated with diet. Perivascular adipose tissue (PVAT) was reportedly involved in the regulation of vascular functions. It is suggested that imbalanced diets can cause PVAT inflammation and dysfunction as well as impaired vascular function. However, the association between diets and PVAT are not clearly understood. Here, we showed that a high-fat and a high-sucrose diet affected PVAT at different sites. A high-fat diet induced increased number of large-sized lipid droplets and increased CD (Cluster of differentiation) 68+ macrophage- and monocyte chemotactic protein (MCP)-1-positive areas in the abdominal aortic PVAT (aPVAT). In addition, a high-fat diet caused decreased collagen fibre-positive area and increased CD68+ macrophage- and MCP-1-positive areas in the abdominal aorta. In contrast, a high-sucrose diet induced increased number of large-sized lipid droplets, increased CD68+ macrophage- and MCP-1-positive areas, and decreased UCP-1 positive area in the thoracic aortic PVAT (tPVAT). A high-sucrose diet caused decreased collagen fibre-positive area and increased CD68+ macrophage- and MCP-1-positive areas in the thoracic aorta. These results could be attributed to the different adipocyte populations in the tPVAT and aPVAT. Our results provide pathological evidence to improve our understanding of the relationship between diet and vascular diseases.

Mechanisms of abdominal aortic aneurysm progression: A review

Abdominal aortic aneurysm (AAA) is a common disease associated with significant cardiovascular morbidity and mortality. Up to now, there is still controversy on the choice of treatment method of AAA. Even so, the mechanisms of AAA progression are poorly defined, making targeting new therapies problematic. Current evidence favors an interaction of the hemodynamic microenvironment with local and systemic immune responses. In this review, we aim to provide an update of mechanisms in AAA progression, involving hemodynamics, perivascular adipose tissue, adventitial fibroblasts, vasa vasorum remodeling, intraluminal thrombus, and distribution of macrophage subtypes.

Regional Heterogeneity of Perivascular Adipose Tissue: Morphology, Origin, and Secretome

Perivascular adipose tissue (PVAT) is a unique fat depot with local and systemic impacts. PVATs are anatomically, developmentally, and functionally different from classical adipose tissues and they are also different from each other. PVAT adipocytes originate from different progenitors and precursors. They can produce and secrete a wide range of autocrine and paracrine factors, many of which are vasoactive modulators. In the context of obesity-associated low-grade inflammation, these phenotypic and functional differences become more evident. In this review, we focus on the recent findings of PVAT’s heterogeneity by comparing commonly studied adipose tissues around the thoracic aorta (tPVAT), abdominal aorta (aPVAT), and mesenteric artery (mPVAT). Distinct origins and developmental trajectory of PVAT adipocyte potentially contribute to regional heterogeneity. Regional differences also exist in ways how PVAT communicates with its neighboring vasculature by producing specific adipokines, vascular tone regulators, and extracellular vesicles in a given microenvironment. These insights may inspire new therapeutic strategies targeting the PVAT.

Liver circadian clock disruption alters perivascular adipose tissue gene expression and aortic function in mice

The liver plays a central role that influences cardiovascular disease outcomes through regulation of glucose and lipid metabolism. It is recognized that the local liver molecular clock regulates some liver-derived metabolites. However, it is unknown whether the liver clock may impact cardiovascular function. Perivascular adipose tissue (PVAT) is a specialized type of adipose tissue surrounding blood vessels. Importantly, cross talk between the endothelium and PVAT via vasoactive factors is critical for vascular function. Therefore, we designed studies to test the hypothesis that cardiovascular function, including PVAT function, is impaired in mice with liver-specific circadian clock disruption. Bmal1 is a core circadian clock gene, thus studies were undertaken in male hepatocyte-specific Bmal1 knockout (HBK) mice and littermate controls (i.e., flox mice). HBK mice showed significantly elevated plasma levels of β-hydroxybutyrate, nonesterified fatty acids/free fatty acids, triglycerides, and insulin-like growth factor 1 compared with flox mice. Thoracic aorta PVAT in HBK mice had increased mRNA expression of several key regulatory and metabolic genes, Ppargc1a, Pparg, Adipoq, Lpl, and Ucp1, suggesting altered PVAT energy metabolism and thermogenesis. Sensitivity to acetylcholine-induced vasorelaxation was significantly decreased in the aortae of HBK mice with PVAT attached compared with aortae of HBK mice with PVAT removed, however, aortic vasorelaxation in flox mice showed no differences with or without attached PVAT. HBK mice had a significantly lower systolic blood pressure during the inactive period of the day. These new findings establish a novel role of the liver circadian clock in regulating PVAT metabolic gene expression and PVAT-mediated aortic vascular function.

Inflammatory Gene Expression in Neck Perivascular and Subcutaneous Adipose Tissue in Men With Carotid Stenosis

The inflammatory phenotype of neck adipose tissue (NAT) might reflect its involvement in the pathogenesis of carotid atherosclerosis. We investigated inflammatory gene expression in the subcutaneous and the perivascular (pericarotid) adipose tissue from patients with carotid stenosis (CS) undergoing endarterectomy and a control group of patients without significant carotid atherosclerosis undergoing thyroid surgery. Only male patients were included (n = 13 in each study group). Clinical and biochemical data along with serum leptin, adiponectin, and monocyte chemoattractant protein 1 (MCP-1) were collected. Adipose tissue samples were obtained from both the subcutaneous and pericarotid compartments. Real-time polymerase chain reaction was used to measure gene expression of macrophage markers and adipokines. The CS group had higher subcutaneous and pericarotid visfatin gene expression and higher pericarotid expression of MCP-1 and CD68 genes. The ratio between pericarotid CD206 and CD68 gene expression was similar between study groups. Adiponectin gene expression in both NAT compartments did not differ between groups, but it was negatively associated with body weight. These observations suggest that NAT, and especially the pericarotid compartment, express enhanced inflammatory properties in patients with CS, but the proportion of anti-inflammatory macrophages in advanced atherosclerosis seems to be maintained.

Modulatory Effect of Intermittent Fasting on Adipose Tissue Inflammation: Amelioration of Cardiovascular Dysfunction in Early Metabolic Impairment

Cardiometabolic syndrome (CMS) is a cluster of maladaptive cardiovascular, renal, thrombotic, inflammatory, and metabolic disorders. It confers a high risk of cardiovascular mortality and morbidity. CMS is triggered by major shifts in lifestyle and dietary habits with increased consumption of refined, calorie-dense diets. Evidence indicates that diet-induced CMS is linked to Adipose tissue (AT) inflammation. This led to the proposal that adipose inflammation may be involved in metabolic derangements, such as insulin resistance and poor glycemic control, as well as the contribution to the inflammatory process predisposing patients to increased cardiovascular risk. Therefore, in the absence of direct pharmacological interventions for the subclinical phase of CMS, time restricted feeding regimens were anticipated to alleviate early metabolic damage and subsequent comorbidities. These regimens, referred to as intermittent fasting (IF), showed a strong positive impact on the metabolic state of obese and non-obese human subjects and animal models, positive AT remodeling in face of overnutrition and high fat diet (HFD) consumption, and improved CV outcomes. Here, we summarize the available evidence on the role of adipose inflammation in triggering cardiovascular impairment in the context of diet induced CMS with an emphasis on the involvement of perivascular adipose tissue. As well, we propose some possible molecular pathways linking intermittent fasting to the ameliorative effect on adipose inflammation and cardiovascular dysfunction under such circumstances. We highlight a number of targets, whose function changes in perivascular adipose tissue inflammation and could be modified by intermittent fasting acting as a novel approach to ameliorate the inflammatory status.

Mineralocorticoid Receptor in Myeloid Cells Mediates Angiotensin II-Induced Vascular Dysfunction in Female Mice

Enhanced mineralocorticoid receptor (MR) signaling is critical to the development of endothelial dysfunction and arterial stiffening. However, there is a lack of knowledge about the role of MR-induced adipose tissue inflammation in the genesis of vascular dysfunction in women. In this study, we hypothesize that MR activation in myeloid cells contributes to angiotensin II (Ang II)-induced aortic stiffening and endothelial dysfunction in females via increased pro-inflammatory (M1) macrophage polarization. Female mice lacking MR in myeloid cells (MyMRKO) were infused with Ang II (500 ng/kg/min) for 4 weeks. This was followed by determinations of aortic stiffness and vasomotor responses, as well as measurements of markers of inflammation and macrophage infiltration/polarization in different adipose tissue compartments. MyMRKO mice were protected against Ang II-induced aortic endothelial stiffening, as assessed via atomic force microscopy in aortic explants, and vasorelaxation dysfunction, as measured by aortic wire myography. In alignment, MyMRKO mice were protected against Ang II-induced macrophage infiltration and M1 polarization in visceral adipose tissue (VAT) and thoracic perivascular adipose tissue (tPVAT). Collectively, this study demonstrates a critical role of MR activation in myeloid cells in the pathogenesis of vascular dysfunction in females associated with pro-inflammatory macrophage polarization in VAT and tPVAT. Our data have potential clinical implications for the prevention and management of cardiovascular disease in women, who are disproportionally at higher risk for poor outcomes.

All-trans-retinoic acid ameliorates atherosclerosis, promotes perivascular adipose tissue browning, and increases adiponectin production in Apo-E mice

All-trans-retinoic acid (atRA), an active metabolite of vitamin A, exerts a potential role in the prevention of cardiovascular diseases. It has been shown that atRA ameliorates atherosclerosis while the exact mechanism underlying this protection remains unknown. This study investigated the influence of atRA on insulin resistance (IR), atherosclerosis, and the process of perivascular adipose tissue (PVAT) browning. Moreover, syntheses of adiponectin, adipokine with anti-atherogenic effects, and tumor necrosis factor-alpha (TNF-α), a pro-inflammatory cytokine, were determined in PVAT. Apolipoprotein E-deficient mice (Apo-E) and control C57BL/6J wild-type mice were treated with atRA (5 mg/kg/day) or vehicle (corn oil) by plastic feeding tubes for 8 weeks. Long-term atRA treatment in Apo-E mice did not affect insulin resistance. AtRa administration ameliorated atherosclerosis, induced PVAT browning, and increased adiponectin production in PVAT in Apo-E mice. Furthermore, atRA increased nitric oxide (NO) level but did not affect adiponectin concentration in the aorta of Apo-E mice. These results indicate that atRA ameliorates atherosclerosis in Apo-E mice. We also observed the browning of PVAT. Besides, atRA increased the synthesis of adiponectin in PVAT and augmented NO level in the aorta in ApoE mice.

Role of Inflammation in Vascular Disease-Related Perivascular Adipose Tissue Dysfunction

Perivascular adipose tissue (PVAT) is the connective tissue around most blood vessels throughout the body. It provides mechanical support and maintains vascular homeostasis in a paracrine/endocrine manner. Under physiological conditions, PVAT has anti-inflammatory effects, improves free fatty acid metabolism, and regulates vasodilation. In pathological conditions, PVAT is dysfunctional, secretes many anti-vasodilator factors, and participates in vascular inflammation through various cells and mediators; thus, it causes dysfunction involving vascular smooth muscle cells and endothelial cells. Inflammation is an important pathophysiological event in many vascular diseases, such as vascular aging, atherosclerosis, and hypertension. Therefore, the pro-inflammatory crosstalk between PVAT and blood vessels may comprise a novel therapeutic target for the prevention and treatment of vascular diseases. In this review, we summarize findings concerning PVAT function and inflammation in different pathophysiological backgrounds, focusing on the secretory functions of PVAT and the crosstalk between PVAT and vascular inflammation in terms of vascular aging, atherosclerosis, hypertension, diabetes mellitus, and other diseases. We also discuss anti-inflammatory treatment for potential vascular diseases involving PVAT.

Perivascular Adipose Tissue as an Indication, Contributor to, and Therapeutic Target for Atherosclerosis

Perivascular adipose tissue (PVAT) has been identified to have significant endocrine and paracrine functions, such as releasing bioactive adipokines, cytokines, and chemokines, rather than a non-physiological structural tissue. Considering the contiguity with the vascular wall, PVAT could play a crucial role in the pathogenic microenvironment of atherosclerosis. Growing clinical evidence has shown an association between PVAT and atherosclerosis. Moreover, based on computed tomography, the fat attenuation index of PVAT was verified as an indication of vulnerable atherosclerotic plaques. Under pathological conditions, such as obesity and diabetes, PVAT shows a proatherogenic phenotype by increasing the release of factors that induce endothelial dysfunction and inflammatory cell infiltration, thus contributing to atherosclerosis. Growing animal and human studies have investigated the mechanism of the above process, which has yet to be fully elucidated. Furthermore, traditional treatments for atherosclerosis have been proven to act on PVAT, and we found several studies focused on novel drugs that target PVAT for the prevention of atherosclerosis. Emerging as an indication, contributor to, and therapeutic target for atherosclerosis, PVAT warrants further investigation.

Intrinsic Exercise Capacity and Mitochondrial DNA Lead to Opposing Vascular-Associated Risks

Exercise capacity is a strong predictor of all-cause morbidity and mortality in humans. However, the associated hemodynamic traits that link this valuable indicator to its subsequent disease risks are numerable. Additionally, exercise capacity has a substantial heritable component and genome-wide screening indicates a vast amount of nuclear and mitochondrial DNA (mtDNA) markers are significantly associated with traits of physical performance. A long-term selection experiment in rats confirms a divide for cardiovascular risks between low- and high-capacity runners (LCR and HCR, respectively), equipping us with a preclinical animal model to uncover new mechanisms. Here, we evaluated the LCR and HCR rat model system for differences in vascular function at the arterial resistance level. Consistent with the known divide between health and disease, we observed that LCR rats present with resistance artery and perivascular adipose tissue dysfunction compared to HCR rats that mimic qualities important for health, including improved vascular relaxation. Uniquely, we show by generating conplastic strains, which LCR males with mtDNA of female HCR (LCR-mt^HCR/Tol) present with improved vascular function. Conversely, HCR-mt^LCR/Tol rats displayed indices for cardiac dysfunction. The outcome of this study suggests that the interplay between the nuclear genome and the maternally inherited mitochondrial genome with high intrinsic exercise capacity is a significant factor for improved vascular physiology, and animal models developed on an interaction between nuclear and mtDNA are valuable new tools for probing vascular risk factors in the offspring.

Perivascular Adipose Tissue and Vascular Perturbation/Atherosclerosis

Atherosclerosis is orchestrated by complex interactions between vascular and inflammatory cells. Traditionally, it has been considered to be an intimal inflammatory disease, characterized by endothelial dysfunction, inflammatory cell recruitment, lipid oxidation, and foam cell formation. This inside-out signaling paradigm has been accepted as dogma for many years, despite the fact that inflammatory cells are far more prevalent in the adventitia compared with the intima. For decades, the origin of adventitial inflammation in atherosclerosis was unknown. The fact that these inflammatory cells were observed to cluster at the margin of perivascular adipose tissues-a unique and highly inflammatory adipose depot that surrounds most atherosclerosis-prone blood vessels-has stimulated interest in perivascular adipose tissue-mediated outside-in signaling in vascular pathophysiology, including atherosclerosis. The phenotype of perivascular adipocytes underlies the functional characteristics of this depot, including its role in adventitial inflammatory cell recruitment, trafficking to the intima via the vasa vasorum, and atherosclerosis perturbation. This review is focused on emerging concepts pertaining to outside-in signaling in atherosclerosis driven by dysfunctional perivascular adipose tissues during diet-induced obesity and recent strategies for atherosclerosis prediction and prognostication based upon this hypothesis.

Targeting perivascular and epicardial adipose tissue inflammation: therapeutic opportunities for cardiovascular disease

Major shifts in human lifestyle and dietary habits toward sedentary behavior and refined food intake triggered steep increase in the incidence of metabolic disorders including obesity and Type 2 diabetes. Patients with metabolic disease are at a high risk of cardiovascular complications ranging from microvascular dysfunction to cardiometabolic syndromes including heart failure. Despite significant advances in the standards of care for obese and diabetic patients, current therapeutic approaches are not always successful in averting the accompanying cardiovascular deterioration. There is a strong relationship between adipose inflammation seen in metabolic disorders and detrimental changes in cardiovascular structure and function. The particular importance of epicardial and perivascular adipose pools emerged as main modulators of the physiology or pathology of heart and blood vessels. Here, we review the peculiarities of these two fat depots in terms of their origin, function, and pathological changes during metabolic deterioration. We highlight the rationale for pharmacological targeting of the perivascular and epicardial adipose tissue or associated signaling pathways as potential disease modifying approaches in cardiometabolic syndromes.

2019 Russell Ross Memorial Lecture in Vascular Biology: B Lymphocyte-Mediated Protective Immunity in Atherosclerosis

Atherosclerosis-the major underlying pathology of cardiovascular disease-is characterized by accumulation and subsequent oxidative modification of lipoproteins within the artery wall, leading to inflammatory cell infiltration and lesion formation that can over time result in arterial stenosis, ischemia, and downstream adverse events. The contribution of innate and adaptive immunity to atherosclerosis development is well established, and B cells have emerged as important modulators of both pro- and anti-inflammatory effects in atherosclerosis. Murine B cells can broadly be divided into 2 subsets: (1) B-2 cells, which are bone marrow derived and include conventional follicular and marginal zone B cells, and (2) B-1 cells, which are largely fetal liver derived and persist in adults through self-renewal. B-cell subsets are developmentally, functionally, and phenotypically distinct with unique subset-specific contributions to atherosclerosis development. Mechanisms whereby B cells regulate vascular inflammation and atherosclerosis will be discussed with a particular emphasis on B-1 cells. B-1 cells have a protective role in atherosclerosis that is mediated in large part by IgM antibody production. Accumulating evidence over the last several years has pointed to a previously underappreciated heterogeneity in B-1 cell populations, which may have important implications for understanding atherosclerosis development and potential targeted therapeutic approaches. This heterogeneity within atheroprotective innate B-cell subsets will be highlighted.

B Lymphocytes and Macrophages in the Perivascular Adipose Tissue Are Associated With Coronary Atherosclerosis: An Autopsy Study

Background

Macrophages and T lymphocytes in the perivascular adipose tissue (PvAT) were previously linked to coronary artery disease. However, the role of these cells and B lymphocytes in the human PvAT adjacent to unstable atherosclerotic plaques has not been investigated. Moreover, previous studies were inconclusive on whether PvAT inflammation was restricted to the surroundings of the atheroma plaque.

Methods and Results

Coronary arteries were freshly dissected with the surrounding PvAT. Atherosclerotic plaques were classified according to the internationally accepted anatomopathological criteria. Immune cells in the PvAT were detected using immunohistochemistry and then quantified. We used linear and logistic regressions with robust standard errors, adjusted for possible confounding factors. In 246 atherosclerotic plaques (205 stable and 41 unstable plaques) from 82 participants (mean age=69.0±14.4 years; 50% men), the percentage of arterial obstruction was positively correlated with the densities of CD68⁺ macrophages (P=0.003) and CD20⁺ B lymphocytes (P=0.03) in the periplaque PvAT. The number of cells was greater in the periplaque PvAT than in the distal PvAT (macrophages, P<0.001; B lymphocytes, P=0.04). In addition, the density of macrophages in the periplaque PvAT was greater in the presence of unstable plaques (P=0.03) and was also greater near unstable plaques than in the distal PvAT (P=0.001). CD3⁺ T lymphocytes were not associated with percentage of obstruction and stable/unstable plaque composition.

Conclusions

The density of CD20⁺ B lymphocytes and CD68⁺ macrophages in periplaque PvAT was increased with plaque size, and the CD68⁺ macrophages were greater near unstable atherosclerotic plaques than near stable lesions. This inflammation was more intense in the periplaque PvAT than in the PvAT distal to the atherosclerotic plaques.

Sulfated polysaccharide from Undaria pinnatifida stabilizes the atherosclerotic plaque via enhancing the dominance of the stabilizing components

The purpose of this study was to investigate the stable effect and mechanism of sulfated polysaccharide from Undaria pinnatifida (SPUP) on atherosclerotic plaque. The results showed that atherosclerotic plaques in the ApoE-/- mice of high-fat diet model group increased significantly without drug intervention. The content of vulnerable components (lipid, inflammatory macrophage) increased significantly, and the content of stability components (smooth muscle cell, collagen) reduced significantly. However, it could find that atherosclerotic plaque areas were decreased in a dose-dependent manner after SPUP intervention. SPUP could enhance the dominance of the stability components in plaque, and reduce the content of vulnerable component. Furthermore, SPUP could significantly reduce the matrix metalloprotein-9 content in atherosclerotic plaque. These results suggested that SPUP could stabilize atherosclerotic plaque by enhancing the dominance of the stability components content, reducing the vulnerability components content, and lowering the vulnerability index value.

Perivascular Adipocytes in Vascular Disease

Perivascular adipocytes residing in the vascular adventitia are recognized as distinct endocrine cells capable of responding to inflammatory stimuli and communicating with the sympathetic nervous system and adjacent blood vessel cells, thereby releasing adipocytokines and other signaling mediators to maintain vascular homeostasis. Perivascular adipocytes exhibit phenotypic heterogeneity (both white and brown adipocytes) and become dysfunctional in conditions, such as diet-induced obesity, thus promoting vascular inflammation, vasoconstriction, and smooth muscle cell proliferation to potentially contribute to the development of vascular diseases, such as atherosclerosis, hypertension, and aortic aneurysms. Although accumulating data have advanced our understanding of the role of perivascular adipocytes in modulating vascular function, their impact on vascular disease, particularly in humans, remains to be fully defined. This brief review will discuss the mechanisms whereby perivascular adipocytes regulate vascular disease, with a particular emphasis on recent findings and current limitations in the field of research.

Exosomes derived from mangiferin‑stimulated perivascular adipose tissue ameliorate endothelial dysfunction

Perivascular adipose tissue (PVAT) is considered to serve a vital role during the development of endothelial dysfunction. The current study investigated the effect of exosomes derived from mangiferin-stimulated PVAT on endothelial function, including regeneration, migration, apoptosis and inflammation. The number of exosomes secreted by PVAT was increased by stimulation with mangiferin (0.1, 1 or 10 µM), and uptake of these exosomes by endothelial cells was observed. Exosomes produced by stimulation of PVAT with mangiferin reversed the effects of inflammation-induced endothelial dysfunction following palmitic acid (PA) treatment. Furthermore, nuclear factor (NF)-κB signaling in endothelial cells was significantly increased when treated with PA-induced PVAT-derived exosomes, whereas exosomes from the supernatant of PVAT stimulated with mangiferin reduced p65 and p50 phosphorylation levels in the cells, and inhibited p65 transportation to the nucleus. Taken together, the present study demonstrated that exosomes derived from mangiferin-stimulated PVAT supernatant inhibited inflammation-induced endothelial dysfunction via modulation of NF-κB signaling.