Mechanisms of Vascular Remodeling in Hypertension

Sex differences and role of lysyl oxidase-like 2 in angiotensin II-induced hypertension in mice

Hypertension, a disease with known sexual dimorphism, accelerates aging-associated arterial stiffening, partly because of the activation of matrix remodeling caused by increased biomechanical load. In this study, we tested the effect of biological sex and the role of the matrix remodeling enzyme lysyl oxidase-like 2 (LOXL2) in hypertension-induced arterial stiffening. Hypertension was induced by angiotensin II (ANG II) infusion via osmotic minipumps in 12- to 14-wk-old male and female mice. Blood pressure and pulse wave velocity (PWV) were measured noninvasively. Wire myography and uniaxial tensile testing were used to test aortic vasoreactivity and mechanical properties. Aortic wall composition was examined by histology and Western blotting. Uniaxial stretch of cultured cells was used to evaluate the effect of biomechanical strain. LOXL2's catalytic function was examined using knockout and inhibition. ANG II infusion-induced hypertension in both genotypes and sexes. Wild-type (WT) males exhibited arterial stiffening in vivo and ex vivo. Aortic remodeling with increased wall thickness, intralamellar distance, higher LOXL2, and collagen I and IV content was noted in WT males. Female mice did not exhibit increased PWV despite the onset of hypertension. LOXL2 depletion improved vascular reactivity and mechanics in hypertensive males. LOXL2 depletion improved aortic mechanics but worsened hypercontractility in females. Hypertensive cyclic strain contributed to LOXL2 upregulation in the cell-derived matrix in vascular smooth muscle cells (VSMCs) but not endothelial cells. LOXL2's catalytic function facilitated VSMC alignment in response to biomechanical strain. In conclusion, in males, arterial stiffening in hypertension is driven both by VSMC response and matrix remodeling. Females are protected from PWV elevation in hypertension. LOXL2 depletion is protective in males with improved mechanical and functional aortic properties. VSMCs are the primary source of LOXL2 in the aorta, and hypertension increases LOXL2 processing and shifts to collagen I accumulation. Overall, LOXL2 depletion offers protection in young hypertensive males and females.NEW & NOTEWORTHY We examined the effect of sex on the evolution of angiotensin II (ANG II)-induced hypertension and the role of lysyl oxidase-like 2 (LOXL2), an enzyme that catalyzes matrix cross linking. While ANG II led to hypertension and worsening vascular reactivity in both sexes, aortic remodeling and stiffening occurred only in males. LOXL2 depletion improved outcomes in males but not females. Thus males and females exhibit a distinct etiology of hypertension and LOXL2 is an effective target in males.

Biophysically stressed vascular smooth muscle cells express MCP-1 via a PDGFR-β-HMGB1 signaling pathway

Vascular smooth muscle cells (VSMCs) under biophysical stress play an active role in the progression of vascular inflammation, but the precise mechanisms are unclear. This study examined the cellular expression of monocyte chemoattractant protein 1 (MCP-1) and its related mechanisms using cultured rat aortic VSMCs stimulated with mechanical stretch (MS, equibiaxial cyclic stretch, 60 cycles/ min). When the cells were stimulated with 10% MS, MCP-1 expression was markedly increased compared to those in the cells stimulated with low MS intensity (3% or 5%). An enzyme-linked immunosorbent assay revealed an increase in HMGB1 released into culture media from the cells stimulated with 10% MS compared to those stimulated with 3% MS. A pretreatment with glycyrrhizin, a HMGB1 inhibitor, resulted in the marked attenuation of MCP-1 expression in the cells stimulated with 10% MS, suggesting a key role of HMGB1 on MCP-1 expression. Western blot analysis revealed higher PDGFR-α and PDGFR-β expression in the cells stimulated with 10% MS than 3% MS-stimulated cells. In the cells deficient of PDGFR-β using siRNA, but not PDGFR-α, HMGB1 released into culture media was significantly attenuated in the 10% MS-stimulated cells. Similarly, MCP-1 expression induced in 10% MS-stimulated cells was also attenuated in cells deficient of PDGFR-β. Overall, the PDGFR-β signaling plays a pivotal role in the increased expression of MCP-1 in VSMCs stressed with 10% MS. Therefore, targeting PDGFR-β signaling in VSMCs might be a promising therapeutic strategy for vascular complications in the vasculatures under excessive biophysical stress.

Mechanism and functional substances of Saiga antelope horn in treating hypertension with liver-yang hyperactivity syndrome explored using network pharmacology and metabolomics

ETHNOPHARMACOLOGICAL RELEVANCE

Saiga antelope horn (SAH) is a traditional Chinese medicine for treating hypertension with liver-yang hyperactivity syndrome (Gan-Yang-Shang-Kang, GYSK), that has a long history of clinical application and precise efficacy, but its mechanism and functional substances are still unknown. Based on the demand for alternative research on the rare and endangered SAH, the group designed and carried out the following studies.

AIM OF THE STUDY

The purpose of this research was to demonstrate the functional substances and mechanisms of SAH in the treatment of GYSK hypertension.

MATERIALS AND METHODS

The GYSK-SHR model was constructed by administering a decoction of aconite to spontaneously hypertensive rats (SHRs). Blood pressure (BP), behavioural tests related to GYSK, and pathological changes in the kidneys, heart and aorta were measured to investigate the effects of SAH on GYSK-SHRs. Proteomic analysis was used to identify the keratins and peptides of SAH. Moreover, network pharmacology and plasma metabolomics studies were carried out to reveal the mechanisms by which functional peptides in SAH regulate GYSK-hypertension.

RESULTS

SAH has a significant antihypertensive effect on GYSK hypertensive animals. It has also been proven to be effective in protecting the function and structural integrity of the kidneys, heart and aorta. Moreover, SAH improved the abnormalities of 31 plasma biomarkers in rats. By constructing a "biomarker-target-peptide" network, 10 functional peptides and two key targets were screened for antihypertensive effects of SAH. The results indicated that SAH may exert a therapeutic effect by re-establishing the imbalance of renin-angiotensin (RAS) system.

CONCLUSIONS

Functional peptides from keratin contained in SAH are the main material basis for the treatment of GYSK-hypertension and exhibited the protective effect on the GYSK-SHR model through the RAS system.

Interleukin-10 deficiency induces thoracic perivascular adipose tissue whitening and vascular remodeling

Perivascular adipose tissue (PVAT) is an adipose layer, surrounding blood vessels, with a local modulatory role. Interleukin-10 (IL-10) has been shown to modulate vascular tissue. This study aimed to characterize the endogenous role of IL-10 in vascular remodeling, and PVAT phenotyping. Thoracic aortic segments from control (C57BL/6J) and IL-10 knockout (IL-10-/-) male mice were used. Analyzes of aorta/PVAT morphometry, and elastin, collagen and reticulin deposition were performed. Tissue uncoupling protein 1 (UCP1) was accessed by Western blotting. Endogenous absence of IL-10 reduced total PVAT area (p = 0.0310), and wall/lumen ratio (p = 0.0024), whereas increased vascular area and thickness (p < 0.0001). Total collagen deposition was augmented in IL-10-/-, but under polarized light, the reduction of collagen-I (p = 0.0075) and the increase of collagen-III (p = 0.0055) was found, simultaneously with reduced elastic fibers deposition (p = 0.0282) and increased deposition of reticular fibers (p < 0.0001). Adipocyte area was augmented in the IL-10 absence (p = 0.0225), and UCP1 expression was reduced (p = 0.0420). Moreover, relative frequency of white adipose cells and connective tissue was augmented in IL-10-/- (p < 0.0001), added to a reduction in brown adipose cells (p < 0.0001). Altogether, these data characterize aorta PVAT from IL-10-/- as a white-like adipocyte phenotype. Endogenous IL-10 prevents vascular remodeling and favors a brown-like adipocyte phenotype, suggesting a modulatory role for IL-10 in PVAT plasticity.

Asprosin contributes to vascular remodeling in hypertensive rats via superoxide signaling

OBJECTIVE

Proliferation and migration of vascular smooth muscle cells (VSMCs) contribute to vascular remodeling. Asprosin, a newly discovered protein hormone, is involved in metabolic diseases. Little is known about the roles of asprosin in cardiovascular diseases. This study focused on the role and mechanism of asprosin on VSMC proliferation and migration, and vascular remodeling in a rat model of hypertension.

METHODS AND RESULTS

VSMCs were obtained from the aortic media of 8-week-old male Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR). Asprosin was upregulated in the VSMCs of SHR. For in vitro studies, asprosin promoted VSMC proliferation and migration of WKY and SHR, and increased Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) activity, NOX1/2/4 protein expressions and superoxide production. Knockdown of asprosin inhibited the proliferation, migration, NOX activity, NOX1/2 expressions and superoxide production in the VSMCs of SHR. The roles of asprosin in promoting VSMC proliferation and migration were not affected by hydrogen peroxide scavenger, but attenuated by superoxide scavenger, selective NOX1 or NOX2 inhibitor. Toll-like receptor 4 (TLR4) was upregulated in SHR, TLR4 knockdown inhibited asprosin overexpression-induced proliferation, migration and oxidative stress in VSMCs of WKY and SHR. Asprosin was upregulated in arteries of SHR, and knockdown of asprosin in vivo not only attenuated oxidative stress and vascular remodeling in aorta and mesentery artery, but also caused a subsequent persistent antihypertensive effect in SHR.

CONCLUSIONS

Asprosin promotes VSMC proliferation and migration via NOX-mediated superoxide production. Inhibition of endogenous asprosin expression attenuates VSMC proliferation and migration, and vascular remodeling of SHR.

Renal denervation alleviates vascular remodeling in spontaneously hypertensive rats by regulating perivascular adipose tissue

Vascular remodeling is the main pathological process that causes the damage of the target organ of hypertension. Perivascular adipose tissue (PVAT) surrounds blood vessels and plays a key role in the pathogenesis of various cardiovascular diseases. This study aimed to investigate the effects of renal denervation (RDN) on hypertensive vascular remodeling and to elucidate the role of PVAT in this process. Male spontaneously hypertensive rat (SHR) and Wistar-Kyoto (WKY) rat were selected. Aortic vascular remodeling was evaluated using hematoxylin and eosin (H&E) staining and Masson's trichrome staining. Morphological changes in the PVAT were observed through H&E and Oil Red O staining. Dihydroethidium was used to measure oxidative stress levels in PVAT, while western blot analysis was used to determine the expression levels of proteins associated with vascular remodeling. The results showed that the aortic medial thickness, media thickness/lumen diameter, collagen volume fraction, and reactive oxygen species (ROS) level in PVAT were significantly higher in the SHR group than in the WKY group. The indexes mentioned above were lower in the SHR-RDN group than in the SHR group. H&E staining revealed that fat droplets in PVAT in the SHR-RDN group became smaller and browning occurred. Moreover, the protein expression of uncoupling protein-1 (UCP-1) and neuregulin 4 (Nrg4) was significantly increased in the SHR-RDN group. In addition, the expression of adiponectin increased and the expression of leptin decreased in the SHR-RDN group compared to the SHR group. In conclusion, RDN can relieve hypertensive vascular remodeling, which may be associated with PVAT.

Unravelling the molecular interplay: SUMOylation, PML nuclear bodies and vascular cell activity in health and disease

In the seemingly well-researched field of vascular research, there are still many underestimated factors and molecular mechanisms. In recent years, SUMOylation has become increasingly important. SUMOylation is a post-translational modification in which small ubiquitin-related modifiers (SUMO) are covalently attached to target proteins. Sites where these SUMO modification processes take place in the cell nucleus are PML nuclear bodies (PML-NBs) - multiprotein complexes with their essential main component and organizer, the PML protein. PML and SUMO, either alone or as partners, influence a variety of cellular processes, including regulation of transcription, senescence, DNA damage response and defence against microorganisms, and are involved in innate immunity and inflammatory responses. They also play an important role in maintaining homeostasis in the vascular system and in pathological processes leading to the development and progression of cardiovascular diseases. This review summarizes information about the function of SUMO(ylation) and PML(-NBs) in the human vasculature from angiogenesis to disease and highlights their clinical potential as drug targets.

Asprosin promotes vascular inflammation via TLR4-NFκB-mediated NLRP3 inflammasome activation in hypertension

Objective

and design Mild vascular inflammation promotes the pathogenesis of hypertension. Asprosin, a newly discovered adipokine, is closely associated with metabolic diseases. We hypothesized that asprosin might led to vascular inflammation in hypertension via NLRP3 inflammasome formation. This study shows the importance of asprosin in the vascular inflammation of hypertension.

Methods

Primary vascular smooth muscle cells (VSMCs) were obtained from the aorta of animals, including spontaneously hypertensive rats (SHR), Wistar-Kyoto rats (WKY), NLRP3-/- and wild-type mice. Studies were performed in VSMCs in vitro, as well as WKY and SHR in vivo.

Results

Asprosin expressions were up-regulated in VSMCs and media of arteries in SHR. Asprosin overexpression promoted NLRP3 inflammasome activation via Toll-like receptor 4 (TLR4), accompanied with activation of NFκB signaling pathway in VSMCs. Exogenous asprosin protein showed similar roles in promoting NLRP3 inflammasome activation. Knockdown of asprosin restrained NLRP3 inflammasome and p65-NFκB activation in VSMCs of SHR. NLRP3 inhibitor MCC950 or NFκB inhibitor BAY11-7082 attenuated asprosin-caused VSMC proliferation and migration. Asprosin-induced interleukin-1β production, proliferation and migration were attenuated in NLRP3-/- VSMCs. Local asprosin knockdown in common carotid artery of SHR attenuated inflammation and vascular remodeling.

Conclusions

Asprosin promoted NLRP3 inflammasome activation in VSMCs by TLR4-NFκB pathway, and thereby stimulates VSMCs proliferation, migration, and vascular remodeling of SHR.

Marine sourced tripeptide SRP and its sustained-release formulation SRP-PLGA-MS exhibiting antihypertensive effect in spontaneously hypertensive rats and HUVECs

Biopeptides from Sipunculus nudus were reported with good ACE inhibitory activity, and the tripeptide SRP was one with the highest ACE inhibition rate. However, the disadvantage of short half-life limited the development of peptide drugs. Moreover, the distinct mechanism of the peptide inhibiting ACE remained unknown. Thus, in this study, a sustained release formulation of SRP-PLGA-MS was designed and prepared. Its long-lasting antihypertensive effect as well as improvement of vascular pathomorphology was verified in spontaneously hypertensive rat (SHR). In addition, the anti-oxidant activity of SRP in human umbilical vein endothelial cells (HUVECs) was evaluated. The results showed that SRP inhibited the production of ROS and NO, which involve the NADPH oxidase, and Keap1/Nrf2 signaling pathway. This study demonstrated that SRP-PLGA-MS had the potential to develop sustained-release drugs for hypertension treatment.

Donepezil attenuates progression of cardiovascular remodeling and improves prognosis in spontaneously hypertensive rats with chronic myocardial infarction

The acetylcholinesterase inhibitor donepezil restores autonomic balance, reduces inflammation, and improves long-term survival in rats with chronic heart failure (CHF) following myocardial infarction (MI). As arterial hypertension is associated with a significant risk of cardiovascular death, we investigated the effectiveness of donepezil in treating CHF in spontaneously hypertensive rats (SHR). CHF was induced in SHR by inducing permanent MI. After 2 weeks, the surviving SHR were randomly assigned to sham-operated (SO), untreated (UT), or oral donepezil-treated (DT, 5 mg/kg/day) groups, and various vitals and parameters were monitored. After 7 weeks of treatment, heart rate and arterial hypertension reduced significantly in DT rats than in UT rats. Donepezil treatment improved 50-day survival (41% to 80%, P = 0.004); suppressed progression of cardiac hypertrophy, cardiac dysfunction (cardiac index: 133 ± 5 vs. 112 ± 5 ml/min/kg, P < 0.05; left ventricular end-diastolic pressure: 12 ± 3 vs. 22 ± 2 mmHg, P < 0.05; left ventricular +dp/dtmax: 5348 ± 338 vs. 4267 ± 114 mmHg/s, P < 0.05), systemic inflammation, and coronary artery remodeling (wall thickness: 26.3 ± 1.4 vs. 34.7 ± 0.7 μm, P < 0.01; media-to-lumen ratio: 3.70 ± 0.73 vs. 8.59 ± 0.84, P < 0.001); increased capillary density; and decreased plasma catecholamine, B-type natriuretic peptide, arginine vasopressin, and angiotensin II levels. Donepezil treatment attenuated cardiac and coronary artery remodeling, mitigated cardiac dysfunction, and significantly improved the prognosis of SHR with CHF.

The renal vasodilatation from β-adrenergic activation in vivo in rats is not driven by KV7 and BKCa channels

The mechanisms behind renal vasodilatation elicited by stimulation of β-adrenergic receptors are not clarified. As several classes of K channels are potentially activated, we tested the hypothesis that KV7 and BKCa channels contribute to the decreased renal vascular tone in vivo and in vitro. Changes in renal blood flow (RBF) during β-adrenergic stimulation were measured in anaesthetized rats using an ultrasonic flow probe. The isometric tension of segmental arteries from normo- and hypertensive rats and segmental arteries from wild-type mice and mice lacking functional KV7.1 channels was examined in a wire-myograph. The β-adrenergic agonist isoprenaline increased RBF significantly in vivo. Neither activation nor inhibition of KV7 and BKCa channels affected the β-adrenergic RBF response. In segmental arteries from normo- and hypertensive rats, inhibition of KV7 channels significantly decreased the β-adrenergic vasorelaxation. However, inhibiting BKCa channels was equally effective in reducing the β-adrenergic vasorelaxation. The β-adrenergic vasorelaxation was not different between segmental arteries from wild-type mice and mice lacking KV7.1 channels. As opposed to rats, inhibition of KV7 channels did not affect the murine β-adrenergic vasorelaxation. Although inhibition and activation of KV7 channels or BKCa channels significantly changed baseline RBF in vivo, none of the treatments affected β-adrenergic vasodilatation. In isolated segmental arteries, however, inhibition of KV7 and BKCa channels significantly reduced the β-adrenergic vasorelaxation, indicating that the regulation of RBF in vivo is driven by several actors in order to maintain an adequate RBF. Our data illustrates the challenge in extrapolating results from in vitro to in vivo conditions.

Addressing Cardiovascular Toxicity Risk of Electronic Nicotine Delivery Systems in the Twenty-First Century: "What Are the Tools Needed for the Job?" and "Do We Have Them?"

Cigarette smoking is positively and robustly associated with cardiovascular disease (CVD), including hypertension, atherosclerosis, cardiac arrhythmias, stroke, thromboembolism, myocardial infarctions, and heart failure. However, after more than a decade of ENDS presence in the U.S. marketplace, uncertainty persists regarding the long-term health consequences of ENDS use for CVD. New approach methods (NAMs) in the field of toxicology are being developed to enhance rapid prediction of human health hazards. Recent technical advances can now consider impact of biological factors such as sex and race/ethnicity, permitting application of NAMs findings to health equity and environmental justice issues. This has been the case for hazard assessments of drugs and environmental chemicals in areas such as cardiovascular, respiratory, and developmental toxicity. Despite these advances, a shortage of widely accepted methodologies to predict the impact of ENDS use on human health slows the application of regulatory oversight and the protection of public health. Minimizing the time between the emergence of risk (e.g., ENDS use) and the administration of well-founded regulatory policy requires thoughtful consideration of the currently available sources of data, their applicability to the prediction of health outcomes, and whether these available data streams are enough to support an actionable decision. This challenge forms the basis of this white paper on how best to reveal potential toxicities of ENDS use in the human cardiovascular system-a primary target of conventional tobacco smoking. We identify current approaches used to evaluate the impacts of tobacco on cardiovascular health, in particular emerging techniques that replace, reduce, and refine slower and more costly animal models with NAMs platforms that can be applied to tobacco regulatory science. The limitations of these emerging platforms are addressed, and systems biology approaches to close the knowledge gap between traditional models and NAMs are proposed. It is hoped that these suggestions and their adoption within the greater scientific community will result in fresh data streams that will support and enhance the scientific evaluation and subsequent decision-making of tobacco regulatory agencies worldwide.

Mitochondrial fission inhibition protects against hypertension induced by angiotensin II

Mitochondrial dysfunction has been implicated in various types of cardiovascular disease including hypertension. Mitochondrial fission fusion balance is critical to mitochondrial quality control, whereas enhanced fission has been reported in several models of cardiovascular disease. However, limited information is available regarding the contribution of mitochondrial fission in hypertension. Here, we have tested the hypothesis that inhibition of mitochondrial fission attenuates the development of hypertension and associated vascular remodeling. In C57BL6 mice infused with angiotensin II for 2 weeks, co-treatment of mitochondrial fission inhibitor, mdivi1, significantly inhibited angiotensin II-induced development of hypertension assessed by radiotelemetry. Histological assessment of hearts and aortas showed that mdivi1 inhibited vessel fibrosis and hypertrophy induced by angiotensin II. This was associated with attenuation of angiotensin II-induced decline in mitochondrial aspect ratio seen in both the endothelial and medial layers of aortas. Mdivi1 also mitigated angiotensin II-induced cardiac hypertrophy assessed by heart weight-to-body weight ratio as well as by echocardiography. In ex vivo experiments, mdivi1 inhibited vasoconstriction and abolished the enhanced vascular reactivity by angiotensin II in small mesenteric arteries. Proteomic analysis on endothelial cell culture media with angiotensin II and/or mdivi1 treatment revealed that mdivi1 inhibited endothelial cell hypersecretory phenotype induced by angiotensin II. In addition, mdivi1 attenuated angiotensin II-induced protein induction of periostin, a myofibroblast marker in cultured vascular fibroblasts. In conclusion, these data suggest that mdivi1 prevented angiotensin II-induced hypertension and cardiovascular remodeling via multicellular mechanisms in the vasculature.

Vascular Inflammation and Smooth Muscle Contractility: The Role of Nox1-Derived Superoxide and LRRC8 Anion Channels

Vascular inflammation underlies the development of hypertension, and the mechanisms by which it increases blood pressure remain the topic of intense investigation. Proinflammatory factors including glucose, salt, vasoconstrictors, cytokines, wall stress, and growth factors enhance contractility and impair relaxation of vascular smooth muscle cells. These pathways share a dependence upon redox signaling, and excessive activation promotes oxidative stress that promotes vascular aging. Vascular smooth muscle cell phenotypic switching and migration into the intima contribute to atherosclerosis, while hypercontractility increases systemic vascular resistance and vasospasm that can trigger ischemia. Here, we review factors that drive the initiation and progression of this vasculopathy in vascular smooth muscle cells. Emphasis is placed on the contribution of reactive oxygen species generated by the Nox1 NADPH oxidase which produces extracellular superoxide (O2•-). The mechanisms of O2•- signaling remain poorly defined, but recent evidence demonstrates physical association of Nox1 with leucine-rich repeat containing 8 family volume-sensitive anion channels. These may provide a pathway for influx of O2•- to the cytoplasm, creating an oxidized cytoplasmic nanodomain where redox-based signals can affect both cytoskeletal structure and vasomotor function. Understanding the mechanistic links between inflammation, O2•- and vascular smooth muscle cell contractility may facilitate targeting of anti-inflammatory therapy in hypertension.

A Comprehensive Retrospective Study on the Mechanisms of Cyclic Mechanical Stretch-Induced Vascular Smooth Muscle Cell Death Underlying Aortic Dissection and Potential Therapeutics for Preventing Acute Aortic Aneurysm and Associated Ruptures

Acute aortic dissection (AAD) and associated ruptures are the leading causes of death in cardiovascular diseases (CVDs). Hypertension is a prime risk factor for AAD. However, the molecular mechanisms underlying AAD remain poorly understood. We previously reported that cyclic mechanical stretch (CMS) leads to the death of rat aortic smooth muscle cells (RASMCs). This review focuses on the mechanisms of CMS-induced vascular smooth muscle cell (VSMC) death. Moreover, we have also discussed the potential therapeutics for preventing AAD and aneurysm ruptures.

Molecular Mechanisms Underlying Vascular Remodeling in Hypertension

Hypertension, a common cardiovascular disease, is primarily characterized by vascular remodeling. Recent extensive research has led to significant progress in understanding its mechanisms. Traditionally, vascular remodeling has been described as a unidirectional process in which blood vessels undergo adaptive remodeling or maladaptive remodeling. Adaptive remodeling involves an increase in vessel diameter in response to increased blood flow, while maladaptive remodeling refers to the narrowing or thickening of blood vessels in response to pathological conditions. However, recent research has revealed that vascular remodeling is much more complex. It is now understood that vascular remodeling is a dynamic interplay between various cellular and molecular events. This interplay process involves different cell types, including endothelial cells, smooth muscle cells, and immune cells, as well as their interactions with the extracellular matrix. Through these interactions, blood vessels undergo intricate and dynamic changes in structure and function in response to various stimuli. Moreover, vascular remodeling involves various factors and mechanisms such as the renin-angiotensin-aldosterone system (RAS), oxidative stress, inflammation, the extracellular matrix (ECM), sympathetic nervous system (SNS) and mechanical stress that impact the arterial wall. These factors may lead to vascular and circulatory system diseases and are primary causes of long-term increases in systemic vascular resistance in hypertensive patients. Additionally, the presence of stem cells in adventitia, media, and intima of blood vessels plays a crucial role in vascular remodeling and disease development. In the future, research will focus on examining the underlying mechanisms contributing to hypertensive vascular remodeling to develop potential solutions for hypertension treatment. This review provides us with a fresh perspective on hypertension and vascular remodeling, undoubtedly sparking further research efforts aimed at uncovering more potent treatments and enhanced preventive and control measures for this disease.

The role of angiotensin II activation of yes-associated protein/PDZ-binding motif signaling in hypertensive cardiac and vascular remodeling

Vascular remodeling is the pathogenic basis of hypertension and end organ injury, and the proliferation of vascular smooth muscle cells (VSMCs) is central to vascular remodeling. Yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ) are key effectors of the Hippo pathway and crucial for controlling cell proliferation, apoptosis and differentiation. The present study investigated the role of YAP/TAZ in cardiac and vascular remodeling of angiotensin II-induced hypertension. Ang II induced YAP/TAZ activation in the heart and aorta, which was prevented by YAP/TAZ inhibitor verteporfin. Treatment with verteporfin significantly reduced Ang II-induced cardiac and vascular hypertrophy with a mild reduction in systolic blood pressure (SBP), verteporfin attenuated Ang II-induced cardiac and aortic fibrosis with the inhibition of transform growth factor (TGF)β/Smad2/3 fibrotic signaling and extracellular matrix collagen I deposition. Ang II induced Rho A, extracellular signal-regulated kinase 1/2 (ERK1/2) and YAP/TAZ activation in VSMCs, either Rho kinase inhibitor fasudil or ERK inhibitor PD98059 suppressed Ang II-induced YAP/TAZ activation, cell proliferation and fibrosis of VSMCs. Verteporfin also inhibited Ang II-induced VSMC proliferation and fibrotic TGFβ1/Smad2/3 pathway. These results demonstrate that Ang II activates YAP/TAZ via Rho kinase/ERK1/2 pathway in VSMCs, which may contribute to cardiac and vascular remodeling in hypertension. Our results suggest that YAP/TAZ plays a critical role in the pathogenesis of hypertension and end organ damage, and targeting the YAP/TAZ pathway may be a new strategy for the prevention and treatment of hypertension and cardiovascular diseases.

Basic Mechanisms of Brain Injury and Cognitive Decline in Hypertension

Dementia affects almost 50 million adults worldwide, and remains a major cause of death and disability. Hypertension is a leading risk factor for dementia, including Alzheimer disease and Alzheimer disease-related dementias. Although this association is well-established, the mechanisms underlying hypertension-induced cognitive decline remain poorly understood. By exploring the mechanisms mediating the detrimental effects of hypertension on the brain, studies have aimed to provide therapeutic insights and strategies on how to protect the brain from the effects of blood pressure elevation. In this review, we focus on the basic mechanisms contributing to the cerebrovascular adaptions to elevated blood pressure and hypertension-induced microvascular injury. We also assess the cellular mechanisms of neurovascular unit dysfunction, focusing on the premise that cognitive impairment ensues when the dynamic metabolic demands of neurons are not met due to neurovascular uncoupling, and summarize cognitive deficits across various rodent models of hypertension as a resource for investigators. Despite significant advances in antihypertensive therapy, hypertension remains a critical risk factor for cognitive decline, and several questions remain about the development and progression of hypertension-induced cognitive impairment.

LncRNA and Protein Expression Profiles Reveal Heart Adaptation to High-Altitude Hypoxia in Tibetan Sheep

The Tibetan sheep has an intricate mechanism of adaptation to low oxygen levels, which is influenced by both genetic and environmental factors. The heart plays a crucial role in the adaptation of Tibetan sheep to hypoxia. In the present study, we utilized transcriptomic and proteomic technologies to comprehensively analyze and identify the long non-coding RNAs (lncRNAs), genes, proteins, pathways, and gene ontology (GO) terms associated with hypoxic adaptation in Tibetan sheep at three different altitudes (2500 m, 3500 m, and 4500 m). By integrating the differentially expressed (DE) lncRNA target genes, differentially expressed proteins (DEPs), and differentially expressed genes (DEGs), we were able to identify and characterize the mechanisms underlying hypoxic adaptation in Tibetan sheep. Through this integration, we identified 41 shared genes/proteins, and functional enrichment analyses revealed their close association with lipid metabolism, glycolysis/gluconeogenesis, and angiogenesis. Additionally, significant enrichment was observed in important pathways such as the PPAR signaling pathway, glycolysis/gluconeogenesis, the oxoacid metabolic process, and angiogenesis. Furthermore, the co-expression network of lncRNAs and mRNAs demonstrated that lncRNAs (MSTRG.4748.1, ENSOART00020025894, and ENSOART00020036371) may play a pivotal role in the adaptation of Tibetan sheep to the hypoxic conditions of the plateau. In conclusion, this study expands the existing database of lncRNAs and proteins in Tibetan sheep, and these findings may serve as a reference for the prevention of altitude sickness in humans.

Perivascular Adipose Tissue Remodels Only after Elevation of Blood Pressure in the Dahl SS Rat Fed a High-Fat Diet

INTRODUCTION

Tunica media extracellular matrix (ECM) remodeling is well understood to occur in response to elevated blood pressure, unlike the remodeling of other tunicas. We hypothesize that perivascular adipose tissue (PVAT) is responsive to hypertension and remodels as a protective measure.

METHODS

The adventitia and PVAT of the thoracic aorta were used in measuring ECM genes from 5 pairs of Dahl SS male rats on 8 or 24 weeks of feeding from weaning on a control (10% Kcal fat) or high-fat (HF; 60%) diet. A PCR array of ECM genes was performed with cDNA from adventitia and PVAT after 8 and 24 weeks. A gene regulatory network of the differentially expressed genes (DEGs) (HF 2-fold > con) was created using Cytoscape.

RESULTS

After 8 weeks, 29 adventitia but 0 PVAT DEGs were found. By contrast, at 24 weeks, PVAT possessed 47 DEGs while adventitia had 3. Top DEGs at 8 weeks in adventitia were thrombospondin 1 and collagen 8a1. At 24 weeks, thrombospondin 1 was also a top DEG in PVAT. The transcription factor Adarb1 was identified as a regulator of DEGs in 8-week adventitia and 24-week PVAT.

CONCLUSION

These data support that PVAT responds biologically once blood pressure is elevated.

Hypertension linked to Alzheimer's disease via stroke: Mendelian randomization

This study aimed to investigate the relationship between hypertension and Alzheimer's disease (AD) and demonstrate the key role of stroke in this relationship using mediating Mendelian randomization. AD, a neurodegenerative disease characterized by memory loss, cognitive impairment, and behavioral abnormalities, severely affects the quality of life of patients. Hypertension is an important risk factor for AD. However, the precise mechanism underlying this relationship is unclear. To investigate the relationship between hypertension and AD, we used a mediated Mendelian randomization method and screened for mediating variables between hypertension and AD by setting instrumental variables. The results of the mediated analysis showed that stroke, as a mediating variable, plays an important role in the causal relationship between hypertension and AD. Specifically, the mediated indirect effect value for stroke obtained using multivariate mediated MR analysis was 54.9%. This implies that approximately 55% of the risk of AD owing to hypertension can be attributed to stroke. The results suggest that the increased risk of AD owing to hypertension is mediated through stroke. The finding not only sheds light on the relationship between hypertension and AD but also indicates novel methods for the prevention and treatment of AD. By identifying the critical role of stroke in the link between hypertension and AD, this study provides insights into potential interventions that could mitigate the impact of hypertension on AD. This could help develop personalized treatments and help improve the quality of life of patients with AD who suffer from hypertension.

Liensinine improves AngII-induced vascular remodeling via MAPK/TGF-β1/Smad2/3 signaling

ETHNOPHARMACOLOGICAL RELEVANCE

Liensinine(Lien, C37H42N2O6) is an alkaloid compound from plumula nelumbinis that demonstrates an antihypertensive effect. The protective effects of Lien on target organs during hypertension are still unclear.

AIM OF THE STUDY

This study aimed to understand the mechanism of Lien during the treatment of hypertension, with emphasis on vascular protection.

MATERIALS AND METHODS

Lien was extracted and isolated from plumula nelumbinis for further study. In vivo model of Ang II-induced hypertension, non-invasive sphygmomanometer was used to detect the blood pressure in and out of the context of Lien intervention. Ultrasound was used to detect the abdominal aorta pulse wave and media thickness of hypertensive mice, and RNA sequencing was used to detect the differential genes and pathways of blood vessels. The intersection of Lien and MAPK protein molecules was detected by molecular interconnecting technique. The pathological conditions of abdominal aorta vessels of mice were observed by HE staining. The expression of PCNA, α-SMA, Collagen Type Ⅰ and Collagen Type Ⅲ proteins were detected by IHC. The collagen expression in the abdominal aorta was detected by Sirius red staining. The MAPK/TGF-β1/Smad2/3 signaling and the protein expression of PCNA and α-SMA was detected by Western blot. In vitro, MAPK/TGF-β1/Smad2/3 signaling and the protein expression of PCNA and α-SMA were detected by Western blot, and the expression of α-SMA was detected by immunofluorescence; ELISA was used to detect the effect of ERK/MAPK inhibitor PD98059 on Ang Ⅱ-induced TGF-β1secrete; and the detection TGF-β1and α-SMA protein expression by Western blot; Western blot was used to detect the effect of ERK/MAPK stimulant12-O-tetradecanoyl phorbol-13-acetate (TPA) on the protein expression of TGF-β1 and α-SMA.

RESULTS

Lien displayed an antihypertensive effect on Ang Ⅱ-induced hypertension, reducing the pulse wave conduction velocity of the abdominal aorta and the thickness of the abdominal aorta vessel wall, ultimately improving the pathological state of blood vessels. RNA sequencing further indicated that the differential pathways expressed in the abdominal aorta of hypertensive mice were enriched in proliferation-related markers compared with the Control group. The profile of differentially expressed pathways was ultimately reversed by Lien. Particularly, MAPK protein demonstrated good binding with the Lien molecule. In vivo, Lien inhibited Ang Ⅱ-induced abdominal aorta wall thickening, reduced collagen deposition in the ventral aortic vessel, and prevented the occurrence of vascular remodeling by inhibiting MAPK/TGF-β1/Smad2/3 signaling activation. In addition, Lien inhibited the activation of Ang II-induced MAPK and TGF-β1/Smad2/3 signaling, attenuating the expression of PCNA and inhibiting the reduction of α-SMA, collectively playing a role in the inhibition of Ang Ⅱ-induced hypertensive vascular remodeling. PD98059 alone could inhibit Ang Ⅱ-induced elevation of TGF-β1 and the decrease of α-SMA expression. Further, PD98059 combined with Lien had no discrepancy with the inhibitors alone. Simultaneously TPA alone could significantly increase the expression of TGF-β1 and decrease the expression of α-SMA. Further, Lien could inhibit the effect of TPA.

CONCLUSION

This study helped clarify the protective mechanism of Lien during hypertension, elucidating its role as an inhibitor of vascular remodeling and providing an experimental basis for the research and development of novel antihypertensive therapies.

Galangin: A food-derived flavonoid with therapeutic potential against a wide spectrum of diseases

Galangin is an important flavonoid with natural activity, that is abundant in galangal and propolis. Currently, various biological activities of galangin have been disclosed, including anti-inflammation, antibacterial effect, anti-oxidative stress and aging, anti-fibrosis, and antihypertensive effect. Based on the above bioactivities, more and more attention has been paid to the role of galangin in neurodegenerative diseases, rheumatoid arthritis, osteoarthritis, osteoporosis, skin diseases, and cancer. In this paper, the natural sources, pharmacokinetics, bioactivities, and therapeutic potential of galangin against various diseases were systematically reviewed by collecting and summarizing relevant literature. In addition, the molecular mechanism and new preparation of galangin in the treatment of related diseases are also discussed, to broaden the application prospect and provide reference for its clinical application. Furthermore, it should be noted that current toxicity and clinical studies of galangin are insufficient, and more evidence is needed to support its possibility as a functional food.

Resolvin E1/ChemR23 Protects Against Hypertension and Vascular Remodeling in Angiotensin II-Induced Hypertensive Mice

BACKGROUND

Inflammation plays a critical role in the development of hypertension and vascular remodeling. Resolvin E1 (RvE1), as one of the specialized proresolving lipid mediators, promotes inflammation resolution by binding with a G protein-coupled receptor, ChemR23 (chemerin receptor 23). However, whether RvE1/ChemR23 regulates hypertension and vascular remodeling is unknown.

METHODS

Hypertension in mice was induced by Ang II (angiotensin II) infusion (750 ng/kg per minute), and RvE1 (2 µg/kg per day) was administered through intraperitoneal injection. Loss of ChemR23 was achieved by mice receiving intravenous injection of adeno-associated virus 9-encoding shRNA against ChemR23.

RESULTS

Aortic ChemR23 expression was increased in Ang II-induced hypertensive mice and that ChemR23 was mainly expressed on vascular smooth muscle cells (VSMCs). RvE1 lowered blood pressure, reduced aortic media thickness, attenuated aortic fibrosis, and mitigated VSMC phenotypic transformation and proliferation in hypertensive mice, which were all reversed by the knockdown of ChemR23. Moreover, RvE1 reduced the aortic infiltration of macrophages and T cells, which was also reversed by ChemR23 knockdown. RvE1 inhibited Ccl5 expression in VSMCs via the AMPKα (AMP-activated protein kinase α)/Nrf2 (nuclear factor E2-related factor 2)/canonical NF-κB (nuclear factor κB) pathway, thereby reducing the infiltration of macrophages and T cells. The AMPKα/Nrf2 pathway also mediated the effects of RvE1 on VSMC phenotypic transformation and proliferation. In patients with hypertension, the serum levels of RvE1 and other eicosapentaenoic acid-derived metabolites were significantly decreased.

CONCLUSIONS

RvE1/ChemR23 ameliorated hypertension and vascular remodeling by activating AMPKα/Nrf2 signaling, which mediated immune cell infiltration by inhibiting the canonical NF-κB/Ccl5 pathway, and regulated VSMC proliferation and phenotypic transformation. RvE1/ChemR23 may be a potential therapeutic target for hypertension.

Drivers of vascular growth and remodeling: A computational framework to promote benign adaptation in the Ross procedure

In the sixties, Dr Donald Ross designed a surgical solution for young patients with aortic valve disease by using the patients' own pulmonary valve. The Ross procedure is the only aortic valve replacement technique that can restore long-term survival and preserve quality of life. The main failure mode of the Ross procedure is wall dilatation, potentially leading to valve regurgitation and leakage. Dilatation occurs due to the inability of the pulmonary autograft to adapt to the sudden increase in loading when exposing to aortic pressures. Previous experimental data has shown that a permanent external support wrapped around the artery can prevent the acute dilatation of the arterial wall. However, the textile support leads to stress-shielding phenomena due to the loss of mechanical wall compliance. We present a pragmatic and modular computational framework of arterial growth and remodeling predicting the long-term outcomes of cardiovascular tissue adaptation, with and without textile wrapping. The model integrates mean, systolic and diastolic pressures and assumes the resulting wall stresses to drive the biological remodeling rules. Rather than a single mean pressure or stress deviation from the homeostatic state, we demonstrate that only pulsatile stresses can predict available experimental results. Therefore, we suggest that a biodegradable external support could induce benign remodeling in the Ross procedure. Indeed, a biodegradable textile wrapped around the autograft fulfills the trade-off between prevention of acute dilatation on the one hand and recovery of arterial wall compliance on the other hand. After further validation, the computational framework can set the basis for the development of an actual biodegradable external support for the Ross procedure with optimized polymer mechanical properties and degradation behavior.

High-resolution magnetic resonance imaging investigation of the connection between the triglyceride-glucose index and intracranial arterial remodeling: a retrospective cross-sectional study

Background

Insulin resistance (IR) is associated with atherosclerotic plaque progression and the occurrence of stroke, with the triglyceride-glucose (TyG) index serving as a surrogate indicator. The present study aimed to investigate the association between TyG index levels and intracranial arterial remodeling in patients with acute ischemic stroke (AIS).

Methods

Patients with AIS who visited the Neurology Department of the Second Hospital of Hebei Medical University and underwent high-resolution magnetic resonance imaging (HR-MRI) between September 2018 and October 2021 were enrolled. A total of 123 patients were finally included in the study, with 81 excluded. The TyG index levels were measured, and the characteristics of intracranial atherosclerotic stenosis (ICAS) plaques were evaluated using HR-MRI. A logistic regression model was employed to analyze the relationship between TyG index levels and remodeling mode. Patients were divided into two groups, positive remodeling (PR) and non-positive remodeling (non-PR), based on the remodeling index (RI).

Results

Patients in the PR group had a higher TyG index than those in the non-PR group {median [interquartile range (IQR)]: 9.11 (8.82-9.51) vs. 8.72 (8.30-9.23), P<0.001}. After adjusting factors such as age and gender, the TyG index was found to be significantly correlated with intracranial arterial PR [odds ratio (OR): 3.169, 95% confidence interval (CI): 1.327-7.569, P=0.009]. In non-diabetes mellitus (DM) patients, the TyG index level in the PR group was significantly higher than that in the non-PR group (8.95±0.42 vs. 8.50±0.45, P<0.001), whereas there was no such difference in patients with DM.

Conclusions

TyG index was correlated with intracranial vessel PR, indicating that the TyG index level may be a useful marker for predicting intracranial vessel PR.

Renal function in very old critically ill patients

PURPOSE OF REVIEW

Current demographic change leads to higher number of elderly patients admitted to an ICU. Among other organs also the kidneys show age-related changes, which are associated with a decline in various aspects of renal function. The purpose of this review is to provide an overview of structural and functional changes in elderly and also to specifically address the increased risk of acute kidney injury (AKI) in this population.

RECENT FINDINGS

Ageing in the kidneys is affected by many different factors, such as low grade chronic inflammation, called inflammageing, and various comorbidities. Nevertheless, a decrease of glomerular filtration rate (GFR) occurs independent of the presence of comorbidities and a steady decline of GFR has been reported in both healthy men and women. Pharmacodynamic of many drugs is altered by these changes. Additionally the rate of diuretic resistance appears to be increased. The cause of AKI occurrence in older age is, multifactorial and includes preventable triggers (hypovolemia, hypotension, nephrotoxins) as well as changes associated with aging.

SUMMARY

Age-related alterations of the kidneys were found at microscopic and macroscopic levels of the cell. These changes lead to a reduced renal reserve and subsequently to an increased vulnerability of aged kidneys when an additional stressor is added. Age is an independent risk factor for developing AKI. Physicians should take into account the altered renal function in elderly patients and take renal protective measures at an early stage.

Unveiling the dual role of autophagy in vascular remodelling and its related diseases

Vascular remodelling is an adaptive response to physiological and pathological stimuli that leads to structural and functional changes in the vascular intima, media, and adventitia. Pathological vascular remodelling is a hallmark feature of numerous vascular diseases, including atherosclerosis, hypertension, abdominal aortic aneurysm, pulmonary hypertension and preeclampsia. Autophagy is critical in maintaining cellular homeostasis, and its dysregulation has been implicated in the pathogenesis of various diseases, including vascular diseases. However, despite emerging evidence, the role of autophagy and its dual effects on vascular remodelling has garnered limited attention. Autophagy can exert protective and detrimental effects on the vascular intima, media and adventitia, thereby substantially influencing the course of vascular remodelling and its related vascular diseases. Currently, there has not been a review that thoroughly describes the regulation of autophagy in vascular remodelling and its impact on related diseases. Therefore, this review aimed to bridge this gap by focusing on the regulatory roles of autophagy in diseases related to vascular remodelling. This review also summarizes recent advancements in therapeutic agents targeting autophagy to regulate vascular remodelling. Additionally, this review offers an overview of recent breakthroughs in therapeutic agents targeting autophagy to regulate vascular remodelling. A deeper understanding of how autophagy orchestrates vascular remodelling can drive the development of targeted therapies for vascular diseases.

The Emerging Therapeutic Role of Prostaglandin E2 Signaling in Pulmonary Hypertension

Mild-to-moderate pulmonary hypertension (PH) is a common complication of chronic obstructive pulmonary disease (COPD). It is characterized by narrowing and thickening of the pulmonary arteries, resulting in increased pulmonary vascular resistance (PVR) and ultimately leading to right ventricular dysfunction. Pulmonary vascular remodeling in COPD is the main reason for the increase of pulmonary artery pressure (PAP). The pathogenesis of PH in COPD is complex and multifactorial, involving chronic inflammation, hypoxia, and oxidative stress. To date, prostacyclin and its analogues are widely used to prevent PH progression in clinical. These drugs have potent anti-proliferative, anti-inflammatory, and stimulating endothelial regeneration properties, bringing therapeutic benefits to the slowing, stabilization, and even some reversal of vascular remodeling. As another well-known and extensively researched prostaglandins, prostaglandin E2 (PGE2) and its downstream signaling have been found to play an important role in various biological processes. Emerging evidence has revealed that PGE2 and its receptors (i.e., EP1-4) are involved in the regulation of pulmonary vascular homeostasis and remodeling. This review focuses on the research progress of the PGE2 signaling pathway in PH and discusses the possibility of treating PH based on the PGE2 signaling pathway.

Inhibitory Effect of β-Sitosterol on the Ang II-Induced Proliferation of A7r5 Aortic Smooth Muscle Cells

Objective

To explore the effects of β-sitosterol on VSMC proliferation.

Materials and Methods

A7r5 cells were pretreated with 2 µM angiotensin II (Ang II) for 24 hr to establish an excessive VSMC proliferation model, followed by treatment with β-sitosterol for 24 hr. Cells were divided into five groups: control, Ang II, and Ang II + β-sitosterol (2, 4, 8 µM). CCK-8 assay, flow cytometry, and Ad-mCherry-GFP-LC3B assay analyzed cell proliferation, cell cycle, cell apoptosis, and autophagic flux. Additionally, the expression of proteins was detected by the western blotting.

Results

β-Sitosterol effectively inhibited Ang II-induced A7r5 cell proliferation (IC50 : 6.841 µM at 24 hr). It achieved this by arresting cell cycle progression, promoting apoptosis, inhibiting autophagy, and suppressing the contractile-synthetic phenotypic switch. Mechanistically, β-sitosterol downregulated PCNA, Cyclin D1, and Bcl-2, while upregulating pro-caspase 3, cleaved-caspase 3, and Bax to induce cell cycle arrest and apoptosis. Additionally, it suppressed the contractile-synthetic phenotypic transformation by downregulating OPN and upregulating α-SMA. The Ad-mCherry-GFP-LC3B Assay and western blotting revealed β-sitosterol's autophagy inhibitory effects by downregulating LC3, ULK1, and Beclin-1 while upregulating P62 expression. Discussion and Conclusion. This study found for the first time that β-sitosterol could inhibit the proliferation of A7r5 cells induced by Ang II. β-Sitosterol treatment may be recommended as a therapeutic strategy to prevent the cardiovascular diseases.

Differential Response to Mechanical Cues in Uterine Fibroid Versus Paired Myometrial Cells

Uterine leiomyomas, or fibroids, are common, benign tumors for which hysterectomy is the only definitive treatment. The extracellular matrix of fibroids is disorganized and stiffer than the surrounding myometrial tissue. To understand how stiffness affects fibroid cells, patient-matched fibroid and myometrial cells were cultured on substrates with stiffnesses varying from 0.2 to 150 kPa. Fibroid cells grew more slowly than myometrial cells overall, and only the myometrial cells altered their growth rate in response to stiffness. In both cell types, cell proliferation decreased with inhibition of PI3K and increased with inhibition of IGF-1. The cellular area was greater for the fibroid cells. The only significant effect of stiffness on the cell area was between the 0.2 and 64 kPa substrates, and this was true for both cell types. To investigate intracellular stiffness, intracellular particle tracking microrheology was used. Fibroid cells exhibited a more than 100-fold increase in elastic modulus at a frequency of 1 Hz in response to the addition of external stress, while myometrial cells showed little change in elastic modulus. Overall, the responses of both cells followed similar trends in response to stiffness and inhibitors, although the response was attenuated in the fibroid cells. The changes that were demonstrated by the change in intracellular stiffness with response to compression suggest that other mechanical forces may provide insight into differences in the two cell types.

Type I collagen proteolysis by matrix metalloproteinase-2 contributes to focal adhesion kinase activation and vascular smooth muscle cell proliferation in the aorta in early hypertension

INTRODUCTION

Increased matrix metalloproteinase (MMP)-2 activity contributes to increase vascular smooth muscle cell (VSMC) proliferation in the aorta in early hypertension by cleaving many proteins of the extracellular matrix. Cleaved products from type I collagen may activate focal adhesion kinases (FAK) that trigger migration and proliferation signals in VSMC. We therefore hypothesized that increased activity of MMP-2 proteolyzes type I collagen in aortas of hypertensive rats, and thereby, induces FAK activation, thus leading to increased VSMC proliferation and hypertrophic remodeling in early hypertension.

METHODS

Male Sprague-Dawley rats were submitted to renovascular hypertension by the two kidney-one clip (2K1C) model and treated with doxycycline (30 mg/kg/day) by gavage from the third to seventh-day post-surgery. Controls were submitted to sham surgery. Systolic blood pressure (SBP) was measured daily by tail-cuff plethysmography and the aortas were processed for zymography and Western blot for MMP-2, pFAK/FAK, integrins and type I collagen. Mass spectrometry, morphological analysis and Ki67 immunofluorescence were also done to identify collagen changes and VSMC proliferation. A7r5 cells were stimulated with collagen and treated with the MMP inhibitors (doxycycline or ARP-100), and with the FAK inhibitor PND1186 for 24 h. Cells were lysed and evaluated by Western blot for pFAK/FAK.

RESULTS

2K1C rats developed elevated SBP in the first week as well as increased expression and activity of MMP-2 in the aorta (p < 0.05 vs. Sham). Treatment with doxycycline reduced both MMP activity and type I collagen proteolysis in aortas of 2K1C rats (p < 0.05). Increased pFAK/FAK and increased VSMC proliferation (p < 0.05 vs. Sham groups) were also seen in the aortas of 2K1C and doxycycline decreased both parameters (p < 0.05). Higher proliferation of VSMC contributed to hypertrophic remodeling as seen by increased media/lumen ratio and cross sectional area (p < 0.05 vs Sham groups). In cell culture, MMP-2 cleaves collagen, an effect reversed by MMP inhibitors (p < 0.05). Increased levels of pFAK/FAK were observed when collagen was added in the culture medium (p < 0.05 vs control) and MMP and FAK inhibitors reduced this effect.

CONCLUSIONS

Increase in MMP-2 activity proteolyzes type I collagen in the aortas of 2K1C rats and contributes to activate FAK and induces VSMC proliferation during the initial phase of hypertension.

MiR-21-3p in extracellular vesicles from vascular fibroblasts of spontaneously hypertensive rat promotes proliferation and migration of vascular smooth muscle cells

Enhanced proliferation and migration of vascular smooth muscle cells (VSMCs) contributes to vascular remodeling in hypertension. Adventitial fibroblasts (AFs)-derived extracellular vesicles (EVs) modulate vascular remodeling in spontaneously hypertensive rat (SHR). This study shows the important roles of EVs-mediated miR-21-3p transfer in VSMC proliferation and migration and underlying mechanisms in SHR. AFs and VSMCs were obtained from aorta of Wistar-Kyoto rat (WKY) and SHR. EVs were separated from AFs culture with ultracentrifugation method. MiR-21-3p content in the EVs of SHR was increased compared with those of WKY. MiR-21-3p mimic promoted VSMC proliferation and migration of WKY and SHR, while miR-21-3p inhibitor attenuated proliferation and migration only in the VSMCs of SHR. EVs of SHR stimulated VSMC proliferation and migration, which were attenuated by miR-21-3p inhibitor. Sorbin and SH3 domain containing 2 (SORBS2) mRNA and protein levels were reduced in the VSMCs of SHR. MiR-21-3p mimic inhibited, while miR-21-3p inhibitor promoted SORBS2 expressions in the VSMCs of both WKY and SHR. EVs of SHR reduced SORBS2 expression, which was prevented by miR-21-3p inhibitor. EVs of WKY had no significant effect on SORBS2 expressions. SORBS2 overexpression attenuated the roles of miR-21-3p mimic and EVs of SHR in promoting VSMC proliferation and migration of SHR. Overexpression of miR-21-3p in vivo promotes vascular remodeling and hypertension. These results indicate that miR-21-3p in the EVs of SHR promotes VSMC proliferation and migration via negatively regulating SORBS2 expression.

Extracellular Matrix Remodeling in Vascular Disease: Defining Its Regulators and Pathological Influence

Because of structural and cellular differences (ie, degrees of matrix abundance and cross-linking, mural cell density, and adventitia), large and medium-sized vessels, in comparison to capillaries, react in a unique manner to stimuli that induce vascular disease. A stereotypical vascular injury response is ECM (extracellular matrix) remodeling that occurs particularly in larger vessels in response to injurious stimuli, such as elevated angiotensin II, hyperlipidemia, hyperglycemia, genetic deficiencies, inflammatory cell infiltration, or exposure to proinflammatory mediators. Even with substantial and prolonged vascular damage, large- and medium-sized arteries, persist, but become modified by (1) changes in vascular wall cellularity; (2) modifications in the differentiation status of endothelial cells, vascular smooth muscle cells, or adventitial stem cells (each can become activated); (3) infiltration of the vascular wall by various leukocyte types; (4) increased exposure to critical growth factors and proinflammatory mediators; and (5) marked changes in the vascular ECM, that remodels from a homeostatic, prodifferentiation ECM environment to matrices that instead promote tissue reparative responses. This latter ECM presents previously hidden matricryptic sites that bind integrins to signal vascular cells and infiltrating leukocytes (in coordination with other mediators) to proliferate, invade, secrete ECM-degrading proteinases, and deposit injury-induced matrices (predisposing to vessel wall fibrosis). In contrast, in response to similar stimuli, capillaries can undergo regression responses (rarefaction). In summary, we have described the molecular events controlling ECM remodeling in major vascular diseases as well as the differential responses of arteries versus capillaries to key mediators inducing vascular injury.

Hypertensive Adults Exhibit Lower Myelin Content: A Multicomponent Relaxometry and Diffusion Magnetic Resonance Imaging Study

BACKGROUND

It is unknown whether hypertension plays any role in cerebral myelination. To fill this knowledge gap, we studied 90 cognitively unimpaired adults, age range 40 to 94 years, who are participants in the Baltimore Longitudinal Study of Aging and the Genetic and Epigenetic Signatures of Translational Aging Laboratory Testing to look for potential associations between hypertension and cerebral myelin content across 14 white matter brain regions.

METHODS

Myelin content was probed using our advanced multicomponent magnetic resonance relaxometry method of myelin water fraction, a direct and specific magnetic resonance imaging measure of myelin content, and longitudinal and transverse relaxation rates (R1 and R2), 2 highly sensitive magnetic resonance imaging metrics of myelin content. We also applied diffusion tensor imaging magnetic resonance imaging to measure fractional anisotropy, mean diffusivity, radial diffusivity, and axial diffusivity values, which are metrics of cerebral microstructural tissue integrity, to provide context with previous magnetic resonance imaging findings.

RESULTS

After adjustment of age, sex, systolic blood pressure, smoking status, diabetes status, and cholesterol level, our results indicated that participants with hypertension exhibited lower myelin water fraction, fractional anisotropy, R1 and R2 values and higher mean diffusivity, radial diffusivity, and axial diffusivity values, indicating lower myelin content and higher impairment to the brain microstructure. These associations were significant across several white matter regions, particularly in the corpus callosum, fronto-occipital fasciculus, temporal lobes, internal capsules, and corona radiata.

CONCLUSIONS

These original findings suggest a direct association between myelin content and hypertension and form the basis for further investigations including longitudinal assessments of this relationship.

Genetic association of hypertension and several other metabolic disorders with Bell's palsy

Background: Effects of hypertension, type 2 diabetes and obesity on Bell's palsy risk remains unclear. The aim of the study was to explore whether hypertension and these metabolic disorders promoted Bell's palsy at the genetic level. Methods: Genetic variants from genome-wide association studies for hypertension, type 2 diabetes, body mass index and several lipid metabolites were adopted as instrumental variables. Two-sample Mendelian randomization including IVW and MR-Egger was used to measure the genetic relationship between the exposures and Bell's palsy. Sensitivity analyses (i.e., Cochran's Q test, MR-Egger intercept test, "leave-one-SNP-out" analysis and funnel plot) were carried out to assess heterogeneity and horizontal pleiotropy. All statistical analyses were performed using R software. Results: Hypertension was significantly associated with the increased risk of Bell's palsy (IVW: OR = 2.291, 95%CI = 1.025-5.122, p = 0.043; MR-Egger: OR = 16.445, 95%CI = 1.377-196.414, p = 0.029). Increased level of LDL cholesterol might upexpectedly decrease the risk of the disease (IVW: OR = 0.805, 95%CI = 0.649-0.998, p = 0.048; MR-Egger: OR = 0.784, 95%CI = 0.573-1.074, p = 0.132). In addition, type 2 diabetes, body mass index and other lipid metabolites were not related to the risk of Bell's palsy. No heterogeneity and horizontal pleiotropy had been found. Conclusion: Hypertension might be a risk factor for Bell's palsy at the genetic level, and LDL cholesterol might reduce the risk of the disease. These findings (especially for LDL cholesterol) need to be validated by further studies.

Hibiscus attenuates renovascular hypertension-induced aortic remodeling dose dependently: the oxidative stress role and Ang II/cyclophilin A/ERK1/2 signaling

Introduction: The high levels of angiotensin II (Ang II) can modify the vascular tone, enhance vascular smooth muscle cells (VSMCs) proliferation and hypertrophy and increase the inflammatory cellular infiltration into the vessel wall. The old herbal nonpharmacological agent, Hibiscus (HS) sabdariffa L has multiple cardioprotective impacts; thus, we investigated the role of HS extract in amelioration of renovascular hypertension (RVH)-induced aortic remodeling. Materials and methods: Thirty-five rats (7/group) were randomly allocated into 5 groups; group: I: Control-sham group, and RVH groups; II, III, IV, and V. The rats in RVH groups were subjected to the modified Goldblatt two-kidneys, one clip (2K1C) for induction of hypertension. In group: II, the rats were left untreated whereas in group III, IV, and V: RVH-rats were treated for 6 weeks with low dose hibiscus (LDH), medium dose hibiscus (MDH), and high dose hibiscus (HDH) respectively. Results: We found that the augmented pro-contractile response of the aortic rings was ameliorated secondary to the in-vivo treatment with HS dose dependently. The cyclophilin A (CyPA) protein levels positively correlated with the vascular adhesion molecule-1 (VCAM-1) and ERK1/2, which, in turn, contribute to the reactive oxygen species (ROS) production. Daily HS intake modified aortic renovation by enhancing the antioxidant capacity, restraining hypertrophy and fibrosis, downregulation of the metastasis associated lung adenocarcinoma transcript (MALAT1), and cyclophilin A (CyPA)/ERK1/2 levels. Discussion: Adding to the multiple beneficial effects, HS aqueous extract was able to inhibit vascular smooth muscle cell proliferation induced by 2K1C model. Thus, adding more privilege for the utilization of the traditional herbal extracts to attenuate RVH-induced aortopathy.

FN (Fibronectin)-Integrin α5 Signaling Promotes Thoracic Aortic Aneurysm in a Mouse Model of Marfan Syndrome

BACKGROUND

Marfan syndrome, caused by mutations in the gene for fibrillin-1, leads to thoracic aortic aneurysms (TAAs). Phenotypic modulation of vascular smooth muscle cells (SMCs) and ECM (extracellular matrix) remodeling are characteristic of both nonsyndromic and Marfan aneurysms. The ECM protein FN (fibronectin) is elevated in the tunica media of TAAs and amplifies inflammatory signaling in endothelial and SMCs through its main receptor, integrin α5β1. We investigated the role of integrin α5-specific signals in Marfan mice in which the cytoplasmic domain of integrin α5 was replaced with that of integrin α2 (denoted α5/2 chimera).

METHODS

We crossed α5/2 chimeric mice with Fbn1mgR/mgR mice (mgR model of Marfan syndrome) to evaluate the survival rate and pathogenesis of TAAs among wild-type, α5/2, mgR, and α5/2 mgR mice. Further biochemical and microscopic analysis of porcine and mouse aortic SMCs investigated molecular mechanisms by which FN affects SMCs and subsequent development of TAAs.

RESULTS

FN was elevated in the thoracic aortas from Marfan patients, in nonsyndromic aneurysms, and in mgR mice. The α5/2 mutation greatly prolonged survival of Marfan mice, with improved elastic fiber integrity, mechanical properties, SMC density, and SMC contractile gene expression. Furthermore, plating of wild-type SMCs on FN decreased contractile gene expression and activated inflammatory pathways whereas α5/2 SMCs were resistant. These effects correlated with increased NF-kB activation in cultured SMCs and mgR aortas, which was alleviated by the α5/2 mutation or NF-kB inhibition.

CONCLUSIONS

FN-integrin α5 signaling is a significant driver of TAA in the mgR mouse model. This pathway thus warrants further investigation as a therapeutic target.

Effects of Long-Term Intervention with Losartan, Aspirin and Atorvastatin on Vascular Remodeling in Juvenile Spontaneously Hypertensive Rats

Hypertension in adolescents is associated with adverse cardiac and vascular events. In addition to lowering blood pressure, it is not clear whether pharmacological therapy in early life can improve vascular remodeling. This study aimed to evaluate the effects of long-term administration of losartan, aspirin, and atorvastatin on vascular remodeling in juvenile spontaneously hypertensive rats (SHRs). Losartan, aspirin, and atorvastatin were administered via gavage at doses of 20, 10, and 10 mg/kg/day, respectively, on SHRs aged 6-22 weeks. Paraffin sections of the blood vessels were stained with hematoxylin-eosin (H&E) and Sirius Red to evaluate the changes in the vascular structure and the accumulation of different types of collagen. The plasma levels of renin, angiotensin II (Ang II), aldosterone (ALD), endothelin-1 (ET-1), interleukin-6 (IL-6), and neutrophil elastase (NE) were determined using ELISA kits. After the 16-week treatment with losartan, aspirin, and atorvastatin, the wall thickness of the thoracic aorta and carotid artery decreased. The integrity of the elastic fibers in the tunica media was maintained in an orderly manner, and collagen deposition in the adventitia was retarded. The plasma levels of renin, ALD, ET-1, IL-6, and NE in the SHRs also decreased. These findings suggest that losartan, aspirin, and atorvastatin could improve vascular remodeling beyond their antihypertensive, anti-inflammatory, and lipid-lowering effects. Many aspects of the protection provided by pharmacological therapy are important for the prevention of cardiovascular diseases in adults and older adults.

Sorting nexins: role in the regulation of blood pressure

Sorting nexins (SNXs) are a family of proteins that regulate cellular cargo sorting and trafficking, maintain intracellular protein homeostasis, and participate in intracellular signaling. SNXs are also important in the regulation of blood pressure via several mechanisms. Aberrant expression and dysfunction of SNXs participate in the dysregulation of blood pressure. Genetic studies show a correlation between SNX gene variants and the response to antihypertensive drugs. In this review, we summarize the progress in SNX-mediated regulation of blood pressure, discuss the potential role of SNXs in the pathophysiology and treatment of hypertension, and propose novel strategies for the medical therapy of hypertension.

Aging Effects on Optic Nerve Neurodegeneration

Common risk factors for many ocular pathologies involve non-pathologic, age-related damage to the optic nerve. Understanding the mechanisms of age-related changes can facilitate targeted treatments for ocular pathologies that arise at any point in life. In this review, we examine these age-related, neurodegenerative changes in the optic nerve, contextualize these changes from the anatomic to the molecular level, and appreciate their relationship with ocular pathophysiology. From simple structural and mechanical changes at the optic nerve head (ONH), to epigenetic and biochemical alterations of tissue and the environment, multiple age-dependent mechanisms drive extracellular matrix (ECM) remodeling, retinal ganglion cell (RGC) loss, and lowered regenerative ability of respective axons. In conjunction, aging decreases the ability of myelin to preserve maximal conductivity, even with "successfully" regenerated axons. Glial cells, however, regeneratively overcompensate and result in a microenvironment that promotes RGC axonal death. Better elucidating optic nerve neurodegeneration remains of interest, specifically investigating human ECM, RGCs, axons, oligodendrocytes, and astrocytes; clarifying the exact processes of aged ocular connective tissue alterations and their ultrastructural impacts; and developing novel technologies and pharmacotherapies that target known genetic, biochemical, matrisome, and neuroinflammatory markers. Management models should account for age-related changes when addressing glaucoma, diabetic retinopathy, and other blinding diseases.

Arterial remodeling: the role of mitochondrial metabolism in vascular smooth muscle cells

Arterial remodeling is a common pathological basis of cardiovascular diseases such as atherosclerosis, vascular restenosis, hypertension, pulmonary hypertension, aortic dissection, and aneurysm. Vascular smooth muscle cells (VSMCs) are not only the main cellular components in the middle layer of the arterial wall but also the main cells involved in arterial remodeling. Dedifferentiated VSMCs lose their contractile properties and are converted to a synthetic, secretory, proliferative, and migratory phenotype, playing key roles in the pathogenesis of arterial remodeling. As mitochondria are the main site of biological oxidation and energy transformation in eukaryotic cells, mitochondrial numbers and function are very important in maintaining the metabolic processes in VSMCs. Mitochondrial dysfunction and oxidative stress are novel triggers of the phenotypic transformation of VSMCs, leading to the onset and development of arterial remodeling. Therefore, pharmacological measures that alleviate mitochondrial dysfunction reverse arterial remodeling by ameliorating VSMCs metabolic dysfunction and phenotypic transformation, providing new options for the treatment of cardiovascular diseases related to arterial remodeling. This review summarizes the relationship between mitochondrial dysfunction and cardiovascular diseases associated with arterial remodeling and then discusses the potential mechanism by which mitochondrial dysfunction participates in pathological arterial remodeling. Furthermore, maintaining or improving mitochondrial function may be a new intervention strategy to prevent the progression of arterial remodeling.

The Association Between 24-Hour Blood Pressure Profiles and Dementia

Midlife hypertension increases risk for dementia. Around one third of adults have diagnosed hypertension; however, many adults are undiagnosed, or remain hypertensive despite diagnosis or treatment. Since blood pressure (BP) follows a circadian rhythm, ambulatory BP monitoring allows for the assessment of BP over a 24-hour period and provides an important tool for improving the diagnosis and management of hypertension. The measurement of 24-hour BP profiles, especially nocturnal BP, demonstrate better predictive ability for cardiovascular disease and mortality than office measurement. However, few studies have examined 24-hour BP profiles with respect to dementia risk. This is an important topic since improvements in BP management could facilitate the primary prevention of vascular cognitive impairment and dementia. Therefore, this review discusses the evidence linking BP to dementia, with a focus on whether the implementation of 24-hour BP measurements can improve risk prediction and prevention strategies. Pathways linking nocturnal BP to dementia are also discussed as are risk reduction strategies. Overall, limited research suggests an association between 24-hour BP elevation and poorer cognition, cerebral small vessel disease, and dementia. However, most studies were cross-sectional. Further evidence is needed to substantiate 24-hour BP profiles, over and above office BP, as predictors of vascular cognitive impairment and incident dementia.

Bone morphogenetic protein 4 in perivascular adipose tissue ameliorates hypertension through regulation of angiotensinogen

BACKGROUND

Perivascular adipose tissue (PVAT), an active endocrine organ, exerts direct effect on vascular tone through paracrine. Activation of PVAT metabolism plays an inhibitory role in atherosclerosis via secreting relaxing factors. The present studies were designed to investigate the role of PVAT metabolism in regulation of hypertension.

MATERIALS AND METHODS

Apolipoprotein E (ApoE) knockout mice with BMP4 knockout in adipose tissue or brown adipose tissue (aP2-DKO or UCP1-DKO, respectively) were used for exploring the role of impaired PVAT metabolism in hypertension. Vascular function was assessed using wire myography. The potential regulatory factor of vascular function was explored using qPCR and ELISA and further confirmed in perivascular fat cell line.

RESULTS

Knockout of BMP4 either in adipose tissue or specifically in BAT aggravates high-fat diet (HFD, 40% fat)-induced hypertension and endothelial dysfunction in ApoE-/- mice. In the meanwhile, deficiency of BMP4 also aggravates Ang II (angiotensin II) -induced hypertension and vascular remodeling in ApoE-/- mice. Moreover, deficiency of BMP4 inhibits NO release and induces ROS production. In vitro system, aortic rings pretreated with PVAT extracts from BMP4-DKO mice showed increased vasoconstriction and reduced endothelial-dependent relaxation compared with the controls. We further demonstrated that PVAT of BMP4-DKO mice expressed higher level of angiotensinogen (AGT) and Ang II compared with the controls.

CONCLUSION

Impaired PVAT metabolism aggravates hypertension, and this effect is dependent on the activation of local renin-angiotensin-aldosterone system (RAAS). The results of this study first demonstrate the regulatory role of PVAT metabolism in hypertension.

Changes in Arterial Stiffness in Response to Various Types of Exercise Modalities: A Narrative Review on Physiological and Endothelial Senescence Perspectives

Arterial stiffness is a reliable independent predictor of cardiovascular events. Exercise training might enhance arterial compliance through improved metabolic health status. Different modes of exercise may have different effects on arterial stiffness. However, the interactions among different modes of exercise on endothelial senescence, the development of arterial vascular stiffness, and the associated molecular mechanisms are not completely understood. In this narrative review, we evaluate the current evidence focusing on the effects of various exercise modes on arterial stiffness and vascular health, and the known underlying physiological mechanisms are discussed as well. Here, we discuss the most recent evidence of aerobic exercise, high-intensity interval training (HIIT), and resistance exercise (RE) on arterial stiffness and endothelial senescence in physiological and cellular studies. Indeed, aerobic, HIIT, and progression RE-induced arterial compliance may reduce arterial stiffness by effectively promoting nitric oxide (NO) bioavailability and reducing endothelial senescence. However, the transient increase in inflammation and sympathetic activation may contribute to the temporary elevation in arterial stiffness following whole-body high-intensity acute resistance exercise.

The adventitia in arterial development, remodeling, and hypertension

The adventitia receives input signals from the vessel wall, the immune system, perivascular nerves and from surrounding tissues to generate effector responses that regulate structural and mechanical properties of blood vessels. It is a complex and dynamic tissue that orchestrates multiple functions for vascular development, homeostasis, repair, and disease. The purpose of this review is to highlight recent advances in our understanding of the origins, phenotypes, and functions of adventitial and perivascular cells with particular emphasis on hypertensive vascular remodeling.

Extracellular vesicles in vascular remodeling

Vascular remodeling contributes to the development of a variety of vascular diseases including hypertension and atherosclerosis. Phenotypic transformation of vascular cells, oxidative stress, inflammation and vascular calcification are closely associated with vascular remodeling. Extracellular vesicles (EVs) are naturally released from almost all types of cells and can be detected in nearly all body fluids including blood and urine. EVs affect vascular oxidative stress, inflammation, calcification, and lipid plaque formation; and thereby impact vascular remodeling in a variety of cardiovascular diseases. EVs may be used as biomarkers for diagnosis and prognosis, and therapeutic strategies for vascular remodeling and cardiovascular diseases. This review includes a comprehensive analysis of the roles of EVs in the vascular remodeling in vascular diseases, and the prospects of EVs in the diagnosis and treatment of vascular diseases.

An integral perspective of canonical cigarette and e-cigarette-related cardiovascular toxicity based on the adverse outcome pathway framework

BACKGROUND

Nowadays, cigarette smoking remains the leading cause of chronic disease and premature death, especially cardiovascular disease. As an emerging tobacco product, e-cigarettes have been advocated as alternatives to canonical cigarettes, and thus may be an aid to promote smoking cessation. However, recent studies indicated that e-cigarettes should not be completely harmless to the cardiovascular system.

AIM OF REVIEW

This review aimed to build up an integral perspective of cigarettes and e-cigarettes-related cardiovascular toxicity.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review adopted the adverse outcome pathway (AOP) framework as a pivotal tool and aimed to elucidate the association between the molecular initiating events (MIEs) induced by cigarette and e-cigarette exposure to the cardiovascular adverse outcome. Since the excessive generation of reactive oxygen species (ROS) has been widely approved to play a critical role in cigarette smoke-related CVD and may also be involved in e-cigarette-induced toxic effects, the ROS overproduction and subsequent oxidative stress are regarded as essential parts of this framework. As far as we know, this should be the first AOP framework focusing on cigarette and e-cigarette-related cardiovascular toxicity, and we hope our work to be a guide in exploring the biomarkers and novel therapies for cardiovascular injury.

Chimonanthus salicifolius attenuated vascular remodeling by alleviating endoplasmic reticulum stress in spontaneously hypertensive rats

Chimonanthus salicifolius (CS), the leaves of Chimonanthus salicifolius S. Y. Hu., is an effective tea to prevent and treat hypertension in China. This study aimed to explore the effect and mechanism of CS in the protection against vascular remodeling in hypertension. Spontaneously hypertensive rats (SHRs) were orally administered with aqueous extracts of CS for 6 months. The blood pressure and morphological changes of the aorta were measured. Their mechanisms were studied by combining chemical identification, network pharmacology analysis and validation in vivo. Hypertensive rats showed an impaired vascular structure and dyslipidemia as illustrated by the increase of the vascular media thickness and collagen deposition in the aorta. CS treatment exhibited significant beneficial effects on blood pressure control and aortal morphology. A total of 21 compounds from CS were identified, which were linked to 106 corresponding targeted genes for vascular remodeling. The network pharmacology predicted that CS prevented vascular remodeling through the endoplasmic reticulum stress pathway. The in vivo experiments further showed that CS treatment upregulated Glucose-Regulated Protein 78 and downregulated CCAAT-enhancer-binding protein homologous protein at both mRNA and protein levels, paralleling reduced apoptotic cells in the arterial wall. Additionally, CS diminished the low-density lipoprotein cholesterol levels, total cholesterol contents and triglyceride/high-density lipoprotein cholesterol ratios in the sera of SHRs, which might also contribute to its protection of vessels. Collectively, CS protects against vascular modeling by suppressing endoplasmic reticulum stress-related apoptosis in hypertension, and it could be a potential agent for the prevention and treatment of vascular modeling.