Model Of Hypertension Research Articles

Clinical and Genetic Markers of Vascular Toxicity in Glioblastoma Patients: Insights from NRG Oncology RTOG-0825.

Glioblastoma (GBM) is an aggressive form of brain cancer in which treatment is associated with toxicities that can result in therapy discontinuation or death. This analysis investigated clinical and genetic markers of vascular toxicities in GBM patients during active treatment. 591 Non-Hispanic White GBM patients with clinical data were included in the analysis from NRG RTOG-0825. Genome-wide association studies (GWAS) were performed from genotyped blood samples (N=367) by occurrence of thrombosis or hypertension (grade ≥2). A clinical prediction model was produced for each vascular toxicity. Significant GWAS variants were then added to the clinical model as a single nucleotide polymorphism (SNP) -dose effect variable to produce the final genetic models. Thrombosis and hypertension were experienced by 62 (11%) and 59 (10%) patients, respectively. Patients who experienced hypertension displayed improved survival over those without hypertension (median overall survival: 25.72 vs 15.47 months, p=0.002). The genetic model of thrombosis included corticosteroid use (OR: 7.13, p=0.02), absolute neutrophil count (OR: 1.008, p=0.19), body surface area (OR: 18.87, p=0.0008), and the SNP-dose effect (3 variants; OR: 3.79, p<.0001). The genetic model of hypertension included bevacizumab use (OR: 0.97, p=0.95) and the SNP-dose effect (6 variants; OR: 4.44, p<.0001). In this study, germline variants were superior in predicting hypertension than clinical variables alone. Additionally, corticosteroid use was a considerable risk factor for thrombosis. Future investigations should confirm the hazard of corticosteroid use on thrombosis and the impact of bevacizumab in other malignancies after accounting for the genetic risk of hypertension.

Overexpression of the inwardly rectifying potassium channel Kir4.1 or Kir4.1 Tyr9 Asp in Müller cells exerts neuroprotective effects in an experimental glaucoma model

Downregulation of the inwardly rectifying potassium channel Kir4.1 is a key step for inducing retinal Müller cell activation and interaction with other glial cells, which is involved in retinal ganglion cell apoptosis in glaucoma. Modulation of Kir4.1 expression in Müller cells may therefore be a potential strategy for attenuating retinal ganglion cell damage in glaucoma. In this study, we identified seven predicted phosphorylation sites in Kir4.1 and constructed lentiviral expression systems expressing Kir4.1 mutated at each site to prevent phosphorylation. Following this, we treated Müller glial cells in vitro and in vivo with the mGluR I agonist DHPG to induce Kir4.1 or Kir4.1 Tyr9Asp overexpression. We found that both Kir4.1 and Kir4.1 Tyr9Asp overexpression inhibited activation of Müller glial cells. Subsequently, we established a rat model of chronic ocular hypertension by injecting microbeads into the anterior chamber and overexpressed Kir4.1 or Kir4.1 Tyr9Asp in the eye, and observed similar results in Müller cells in vivo as those seen in vitro. Both Kir4.1 and Kir4.1 Tyr9Asp overexpression inhibited Müller cell activation, regulated the balance of Bax/Bcl-2, and reduced the mRNA and protein levels of pro-inflammatory factors, including interleukin-1β and tumor necrosis factor-α. Furthermore, we investigated the regulatory effects of Kir4.1 and Kir4.1 Tyr9Asp overexpression on the release of pro-inflammatory factors in a co-culture system of Müller glial cells and microglia. In this co-culture system, we observed elevated adenosine triphosphate concentrations in activated Müller cells, increased levels of translocator protein (a marker of microglial activation), and elevated interleukin-1β mRNA and protein levels in microglia induced by activated Müller cells. These changes could be reversed by Kir4.1 and Kir4.1 Tyr9Asp overexpression in Müller cells. Kir4.1 overexpression, but not Kir4.1 Tyr9Asp overexpression, reduced the number of proliferative and migratory microglia induced by activated Müller cells. Collectively, these results suggest that the tyrosine residue at position nine in Kir4.1 may serve as a functional modulation site in the retina in an experimental model of glaucoma. Kir4.1 and Kir4.1 Tyr9Asp overexpression attenuated Müller cell activation, reduced ATP/P2X receptor-mediated interactions between glial cells, inhibited microglial activation, and decreased the synthesis and release of pro-inflammatory factors, consequently ameliorating retinal ganglion cell apoptosis in glaucoma.

Synapses and dendritic spines are eliminated in the primary visual cortex of mice subjected to chronic intraocular pressure elevation

Synaptic plasticity is essential for maintaining neuronal function in the central nervous system and serves as a critical indicator of the effects of neurodegenerative disease. Glaucoma directly impairs retinal ganglion cells and their axons, leading to axonal transport dysfuntion, subsequently causing secondary damage to anterior or posterior ends of the visual system. Accordingly, recent evidence indicates that glaucoma is a degenerative disease of the central nervous system that causes damage throughout the visual pathway. However, the effects of glaucoma on synaptic plasticity in the primary visual cortex remain unclear. In this study, we established a mouse model of unilateral chronic ocular hypertension by injecting magnetic microbeads into the anterior chamber of one eye. We found that, after 4 weeks of chronic ocular hypertension, the neuronal somas were smaller in the superior colliculus and lateral geniculate body regions of the brain contralateral to the affected eye. This was accompanied by glial cell activation and increased expression of inflammatory factors. After 8 weeks of ocular hypertension, we observed a reduction in the number of excitatory and inhibitory synapses, dendritic spines, and activation of glial cells in the primary visual cortex contralateral to the affected eye. These findings suggest that glaucoma not only directly damages the retina but also induces alterations in synapses and dendritic spines in the primary visual cortex, providing new insights into the pathogenesis of glaucoma.

Abstract 4138674: Long-acting CRF2 receptor agonist, COR-1389, improves cardiopulmonary function in the rat model of Sugen plus hypoxia-induced pulmonary hypertension and right heart failure

Introduction: Urocortin-2 (UCN-2), a peptide which is part of the corticotropin-releasing factor (CRF) family, functions as an autocrine and paracrine factor, exerting its effects on cardiac and pulmonary function through agonism of CRF2 receptors. Although acute administration of UCN-2 has shown promise by improving heart and lung function in conditions like heart failure (HF) and pulmonary hypertension (PH), its limited stability impedes its chronic therapeutic use. Hypothesis: In this study, we explored the efficacy of COR-1389, a potent, selective and long-acting CRF2 agonist peptide, in the Sugen 5416 (VEGFR2 inhibitor, Su) combined with hypoxia (Hx) rat model of PH and right heart failure (RHF). Methods: To this aim, male adult Sprague Dawley rats were divided into three groups: Control rats (normoxia) were compared with rats injected subcutaneously with 20 mg/kg Sugen 5416 and exposed to chronic hypoxia for 3 weeks, followed by 2 weeks of normoxia. At 5 weeks, control rats and one SuHx group received subcutaneously vehicle (control and SuHx), while the third group received COR-1389 at a dose of 100 μg/kg every 4 days subcutaneously for 3 weeks (SuHx + COR-1389). At 8 weeks, cardiac and pulmonary hemodynamic functions of the three groups were evaluated using echocardiography and right heart catheterization, and heart and lung tissue were evaluated by histology and immunohistochemistry. Results: Compared to controls (n=10), SuHx exhibited increased mean pulmonary arterial pressure (mPAP), right ventricle (RV) hypertrophy (Fulton Index/body weight), muscularization of distal pulmonary arteries, RV fibrosis and cardiomyocyte hypertrophy, alongside reduced RV systolic function (Tricuspid Annular Plane Systolic Excursion, TAPSE) and cardiac output (CO). Conversely, compared to the SuHx + vehicle group (n=11), curative treatment with COR-1389 for 3 weeks in SuHx rats (n=13) led to enhanced RV systolic function (TAPSE) and CO, together with reductions in mPAP, RV hypertrophy, muscularization of pulmonary arteries, RV fibrosis and cardiomyocyte hypertrophy. Systolic blood pressure remained unchanged across all groups. Conclusion: These findings indicate that COR-1389 ameliorates the deteriorating cardiopulmonary parameters observed in the SuHx model and represents a promising approach for the treatment of PH and RHF.

Abstract 4137364: Sex differences in the right ventricle in the Sugen-Hypoxia rat model of pulmonary arterial hypertension

Background: An unexplained estrogen puzzle exists in pulmonary arterial hypertension (PAH): PAH occurs ~4 fold more frequently in women than men; however, women with PAH have better right ventricular (RV) function and survival than the men. Sex differences and the associated mechanism in RV in PAH are not well understood. Aim: To characterize sex differences in RV function and structure in PAH. Methods: Sprague-Dawley rats were injected with Sugen (SU5416, 25mg/kg), and subjected to 3 weeks of hypoxia, followed by 5 weeks of normoxia. Control rats received vehicle and stayed in normoxia for up to 8 weeks. RV pressure-volume, mitochondrial properties, weight, myocyte size, cell proliferation, and interstitial and perivascular (right coronary arteries, RCA) fibrosis were obtained. Results: Sugen-Hypoxia (SuHx) caused significant increases in RV systolic pressure (RVSP) and effective arterial elastance (Ea) in both sexes (P&lt;0.05), but caused slightly greater increase in RV end-systolic elastance (Ees) in females vs males, leading to a preserved RV-pulmonary artery coupling (Ees/Ea) in females and a significant decrease in Ees/Ea in males (P&lt;0.05). SuHx caused a significant increase in RV diastolic pressure only in males (P&lt;0.05), which is associated with significantly higher amount of RV interstitial fibrosis in males vs females. In addition, SuHx caused significant increase in cell proliferation in both sexes (P&lt;0.05) though with slightly greater in crease in males, which is well correlated with RV interstitial fibrosis. Whilst there was no sex difference in RV hypertrophy in SuHx rats as indicated by both fulton index and myocyte size, female RV had smaller myocytes than males at baseline, indicating a greater increase in myocyte size in response to SuHx. Finally, there was a significant increase in RCA fibrosis in male SuHx rats (P&lt;0.05) but not in females, potentially leading to a greater degree of ischemia in male SuHx RV, and this is consistent with impaired mitochondrial properties (decreased mitochondrial fusion, membrane potential an superoxide) in male SuHx rat RV (P&lt;0.05) but preserved mitochoindrial properties in females. Conclusions: SuHx resulted in similar level of RV afterload in both sexes, but compared to males, RV in females responded differently in both function (Ees and mitochondrial properties) and structure (myocyte size and fibrosis). Future studies on the associated mechanism are needed to gain therapeutic insight for RV in PAH.

Abstract 4129520: The mechanism of cardiac hypertrophy induced by testosterone in postmenopausal women through the activation of the mTORC2/Atg9a

Objectives: The estrogen level of postmenopausal women decreased sharply, while the androgen level did not decrease significantly, which was characterized by the inversion of estrogen / androgen ratio. Therefore, it could be observed that relative excess androgen in the circulation of postmenopausal women, which may be one of the reasons for the increase of cardiovascular disease in postmenopausal women. In this study, the model of postmenopausal hypertension was established by bilateral ovariectomy in spontaneously hypertensive rats (SHR), and the specific mechanism of testosterone-induced myocardial hypertrophy in ovariectomized SHR was explored. Methods: 24 SHR were randomly divided into four groups: WKY group (n=6), sham operation group (Sham group, n=6), bilateral ovariectomized group (OVX group, n=6) and testosterone propionate intervention group (OVX+T group, 6mg/kg/Weekly, im for 4 weeks, n=6). Western Blot was used to detect the protein expression of β-MHC, ANP, Androgen receptor, Akt, p-Akt, mTORC2 and its subunits Rictor. Moreover, the expression of autophagy-related proteins LC3 was observed. Results: 1. The study revealed that the expression of β-MHC and ANP was significantly increased in both the OVX and OVX+T groups when compared to the WKY and Sham groups. Remarkably, testosterone induced a more significant cardiac hypertrophy response than observed in the OVX group alone. Additionally, the expression of androgen receptors was markedly upregulated in both the OVX and OVX+T groups. These findings strongly suggest that testosterone primarily induces myocardial hypertrophy in SHR after ovariectomy through androgen receptors. 2. Although no significant difference in mTORC2 expression was noted between the WKY, Sham, and OVX groups, testosterone exhibited a notable capacity to activate mTORC2 expression and the p-Rictor subunit in the OVX+T group. 3. The expression of LC3II/LC3I and mitochondrial fission protein DRP1 were increased in the OVX+T group when compared to the WKY, Sham, and OVX groups. While the expression of MFN2 in the four groups shows no significant difference. Meanwhile, the expression of Atg9a was increased in OVX+T group. The results indicate that testosterone might activate mitophagy via inducing the expression of Atg9a. Conclusions: In bilateral ovariectomized SHR, testosterone has the potential to activate mitophagy by activating the mTORC2/Atg9a pathway, which, in turn, leads to cardiac hypertrophy.

Abstract 4119213: A Novel Animal Model for Pulmonary Hypertension: Lung Endothelial Specific Deletion of Egln1 in Mice

Background: Pulmonary arterial hypertension (PAH) is a disastrous disease that is characterized by high blood pressure in the pulmonary arteries which has the potential to lead to heart failure over time. Previously, our lab found that endothelial-specific knockout of Egln1 , encoding prolyl 4-hydroxylase-2 (PHD2), induced spontaneous pulmonary hypertension (PH). Recently, we elucidated that Tmem100 is a lung-specific endothelial gene using Tmem100 CreERT2 mice. We reason that lung endothelial-specific deletion of Egln1 could lead to the development of PH without affecting other organs’ Egln1 gene expression and defect. Methods: Tm em100-CreERT2 mice were crossed with Egln1 flox/flox mice to generate Egln1 f/f ; Tmem100 CreERT2 (LiCKO) mice. Western blot and immunofluorescent staining were performed to verify the knockout efficacy of Egln1 in multiple organs of LiCKO mice. PH phenotypes including hemodynamics, right heart size and function, and pulmonary vascular remodeling were evaluated by right heart catheterization and echocardiography measurement. Results: Tamoxifen treatment induced Egln1 deletion in the lung ECs but no other organs in adult LiCKO mice. LiCKO mice exhibited an increase in right ventricular systolic pressure (RVSP, ~35 mmHg) and right heart hypertrophy. Echocardiography measurement showed right heart hypertrophy and cardiac and pulmonary arterial dysfunction. Pulmonary vascular remodeling including pulmonary wall thickness and muscularization of distal pulmonary arterials was enhanced in LiCKO mice compared to wild-type mice. Conclusions: Tmem100 promoter-mediated lung endothelial knockout of Egln1 in mice develops spontaneous PH. LiCKO mice could be a novel mouse model for PH to study lung and other organ crosstalk.

Abstract 4139169: Treatment with methotrexate associated with LDL-like nanoparticles prevents the development of left ventricular fibrosis in a spontaneously hypertensive rat model

Introduction: Systemic arterial hypertension (SAH) can lead to left ventricle (LV) fibrosis and ventricular dysfunction. Methotrexate (MTX) associated with lipid nanoparticles (LDE) increases the cellular uptake of MTX by ninety-fold, which leads to therapeutic efficacy and reduces drug toxicity. Previously, treatment of rats with myocardial infarction with LDE-MTX decreased LV fibrosis and prevented ventricular dysfunction. The aim was to test LDE-MTX to preclude the development of cardiac damages caused by hypertension in spontaneously hypertensive rats (SHR). Methods: Twenty-four male rats with six-week-old were allocated in 3 groups: Control (CT): Wistar-Kyoto rats injected with saline; SHR: treated with LDE only and SHR-LDE-MTX: treated with LDE-MTX (1mg/Kg/week, I.P.). After 20 weeks of treatment, echocardiography, morphometry and protein expression were performed in the LV. The data were analyzed by ANOVA with Turkey’s post-test or Kruskal-Wallis test with Dunn's post-test. Linear regression was used to evaluate potential relationships. Results: Compared to CT, the two SHR groups showed dilation (increase in systolic and diastolic diameter); hypertrophy (increased thickness of the posterior wall) and systolic dysfunction (decreased ejection and shortening fractions). Furthermore, the SHR group showed increased LV fibrosis in both the interstitial region and the papillary muscle, possibly resulting from increased of type I collagen content. Treatment of SHR with LDE-MTX had no effect on LV dilation, hypertrophy or systolic dysfunction. However, LDE-MTX decreased LV fibrosis of the interstitial region and the papillary muscle. In addition, LDE-MTX increased the expression of MMP-2, and increased the bioavailability of intracellular adenosine, via increased expression of the adenosine A3 receptor. There was a negative correlation between the expression of the adenosine A3 receptor with interstitial fibrosis (r2=-0.31, p=0.03) and papillary muscle (r2=-0.47, p=0.03), indicating that the increased bioavailability of intracellular adenosine also contributed to the decrease in LV fibrosis in SHR. Conclusion: In SHR, treatment with LDE-MTX reduced LV fibrosis, possibly by modulating MMP-2 expression and increasing the bioavailability of intracellular adenosine, via the adenosine A3 receptor. These results suggest a therapeutic role for LDE-MTX in patients with LV fibrosis and heart failure caused by SAH, to be explored in future clinical studies.

Abstract 4137688: Inhibition of Cardiac Fibrosis and Pro-Fibrotic Collagen Hormone Endotrophin by VS-041, a Novel Drug Candidate for Heart Failure with Preserved Ejection Fraction

Introduction: Endotrophin, a collagen type VI–derived signaling peptide, has been linked to cardiac metabolic dysregulation, inflammation, and fibrosis. Several matrix metalloproteinases (MMPs), incl. MMP2 and MMP9, have been shown to cleave collagen 6A3 and release endotrophin. Baseline plasma endotrophin levels in heart failure with preserved ejection fraction (HFpEF) patients were shown to be strongly and independently associated with increased risk of poor outcomes (death or HF-admissions). VS-041 is a novel drug candidate for HFpEF that inhibits key MMPs implicated in cardiac fibrosis and diastolic dysfunction. Previously, VS-041 demonstrated robust efficacy in the Dahl Salt Sensitive rat model of hypertension and HFpEF, improving diastolic function and dose-proportionally reducing left ventricle (LV) fibrosis. Hypothesis: Inhibition of endotrophin release by VS-041 could contribute to its anti-fibrotic mechanism and serve as a potential biomarker of MMP inhibition (target engagement) in patients. Methods and Results: The effect of VS-041 on production of endotrophin was investigated in a “Scar-in-a-Jar” model using primary human cardiac fibroblasts isolated from adult healthy ventricles. Fibroblasts were treated with 10 ng/mL platelet-derived growth factor (PDGF) AB in the presence of 0.03, 0.3, or 3 µM VS-041, or DMSO control. The concentration of endotrophin in the medium was assessed via the ELISA nordicPRO-C6 TM (Nordic Bioscience A/S). After 4 days of treatment, VS-041 at 0.3 µM and 3 µM significantly inhibited PDGF AB-stimulated production of endotrophin. Cumulative inhibitory effects of VS-041 could still be observed after 12 days of culture. The antifibrotic activity of VS-041 was also tested in a model of extensive cardiac fibrosis in 16-months old C57BL/6 mice exacerbated by angiotensin II infusion at 1 mg/kg/day for 28 days. Oral treatment with VS-041 at 75 mg/kg BID resulted in a 62% reduction (p&lt;0.01) of LV fibrosis as assessed by morphometry of Masson trichrome stained sections. VS-041 also improved the diastolic echocardiography parameters IVRT and E/a ratio. Conclusions: The production of endotrophin by fibroblasts is diminished by VS-041 and, therefore, its plasma levels could be explored as a biomarker of in vivo MMP inhibition by VS-041. Additionally, the inhibition of endotrophin release by VS-041 could be causatively linked to reduction of cardiac fibrosis and potentially translate into improved clinical outcomes in HFpEF patients.

Regulation of blood pressure by METTL3 via RUNX1b-eNOS pathway in endothelial cells in mice.

Endothelial cells regulate vascular tone to control the blood pressure (BP) by producing both relaxing and contracting factors. Previously, we identified methyltransferase-like 3 (METTL3), a primary N6-methyladenosine (m6A) methyltransferase, as a key player in alleviating endothelial atherogenic progression. However, its involvement in BP regulation remains unclear. To evaluate the role of METTL3 in vivo, mice with EC specific METTL3 deficiency (EC-Mettl3KO) with or without Ang II infusion were used to create a hypertensive model. Functional and MeRIP sequencing analysis were performed to explore the mechanism of METTL3-mediated hypertension. We observed a reduction in endothelial METTL3 activity by Ang II in vitro and in vivo. Endothelial METTL3-deficient mice exhibited higher BP than controls, with no gender disparity observed. The subsequent study primarily conducted in male mice. Through m6A sequencing and functional analysis, we identified m6A modification of various RUNX1 monomers resulted in endothelial dysfunction. Mutations in the 3'UTR region of RUNX1b abolished its luciferase reporter activity, and enhanced eNOS promoter luciferase reporter activity with or without METTL3 overexpression. Overexpression of METTL3 by adeno-associated virus reduced Ang II-induced BP elevation. This study reveals that METTL3 alleviates hypertension through m6A-dependent stabilization of RUNX1b mRNA, leading to upregulation of eNOS, thus underscoring the pivotal role of RNA transcriptomics in the regulation of hypertension.

Mineralocorticoid Receptor in Endothelial Cells Contributes to VEGF Receptor Inhibitor-Induced Vascular and Kidney Damage.

Vascular endothelial growth factor receptor inhibitors (VEGFRis) improve cancer patient survival by inhibiting tumor angiogenesis. However, VEGFRis induce treatment-limiting hypertension which has been associated with impaired vascular endothelial cell (EC) function and kidney damage. The mineralocorticoid receptor (MR) regulates blood pressure via effects on the vasculature and the kidney. Thus, we interrogated the role of the MR in EC dysfunction, renal impairment, and hypertension in a mouse model of VEGFRi-induced hypertension using sorafenib. EC dysfunction in mesenteric arterioles was assessed by immunoblotting for phosphorylation of endothelial nitric oxide synthase (eNOS) at serine 1177. Renal damage was measured by assessing glomerular endotheliosis histologically. Blood pressure (BP) was measured using implanted radiotelemetry. Six days of sorafenib treatment significantly impaired mesenteric resistance vessel EC function, induced renal damage, and increased BP. Pharmacologic MR blockade with spironolactone prevented the sorafenib-induced decline in eNOS phosphorylation and the renal glomerular endotheliosis, without affecting systolic or diastolic BP. Mice with the MR knocked out specifically in ECs (EC-MR-KO) were protected from sorafenib-induced EC dysfunction and glomerular endotheliosis, whereas smooth muscle cell-specific MR (SMC-MR) knockout mice were not. Neither EC-MR knockout nor SMC-MR knockout affected the degree to which sorafenib increased systolic or diastolic BP. These results reveal that the MR, specifically in EC but not in SMCs, is necessary for VEGFRi-induced renal and vascular injury. While ineffective at lowering SBP, these data suggest potential therapeutic benefits of MR antagonists, like spironolactone, to protect the vasculature and the kidneys from VEGFRi-induced injury.

High dose of liraglutide impairs renal function in female hypertensive rats.

Glucagon-like peptide-1 (GLP-1) receptor agonists exhibit beneficial cardiovascular effects. However, the renal effects of different doses of liraglutide in an essential hypertension model have not yet been investigated. SHR female rats were treated for 30 days, twice a day, with saline (control) or liraglutide at low (0.06 mg/kg, LL) and high (0.6 mg/kg, LH) doses. Volume intake and excretion were monitored for a period of 24h. In renal tissue, nitrite-NO2-, nitrate-NO3-, advanced protein oxidation products-AOPP, collagen deposition, creatinine (Cr), urea (U), sodium, and potassium were analyzed. liraglutide reduced body weight gain in both groups. However, in the high dose, it increased urinary volume excretion and sodium/potassium ratio. Both doses reduced the urinary U/Cr ratio and LH increased the serum U/Cr ratio. AOPP was reduced only in LL. LH augmented collagen and early markers of kidney injury (blood urea nitrogen-BUN, BUN/Cr). LH increased NO3-, reduced NO2-, and caused an aberrant increase in GFR. Both doses' effects were independent of blood pressure and glycemic control. liraglutide appears to have distinct effects on the hypertensive female kidney depending on the dose, with higher doses impairing kidney function.

Hippocampus under pressure: molecular mechanisms of cognitive impairment in shr rats

In clinical studies and in animal experiments, data have been obtained indicating the association of chronic hypertension with the development of cognitive impairment. The review examines structural and biochemical changes in the hippocampus of SHR rats with genetic hypertension, which are used as a model of essential hypertension, as well as vascular dementia. The dysfunction of the hypothalamic-pituitary-adrenocortical system, observed in SHR rats at an early age, may, along with the development of hypertension, be a key factor in the damage to the hippocampus at the structural and molecular levels. Global changes at the body level (hypertension, neurohumoral dysfunction) are associated with the development of vascular pathology and destruction of the blood-brain barrier. Changes in multiple biochemical glucocorticoid-dependent processes in the hippocampus (dysfunction of steroid hormone receptors, disorders of neurotransmitter systems, BDNF deficiency, oxidative stress, neuroinflammation) are accompanied by structural changes including cellular processes of neuroinflammation (microgliosis, astrogliosis), disorders of neurogenesis in the subgranular neurogenic niche, neurodegenerative processes at the level of synapses, axons and dendrites up to neuronal cell death. The consequence of this is dysfunction of the hippocampus, a key structure of the limbic system necessary for the realization of cognitive functions. Summarizing of the available results at various levels, from the level of the organism and the structure of the brain (hippocampus) to the molecular one, allows us to confirm the translational validity of SHR rats for modeling the mechanisms of vascular dementia.

Maternal EGCG intervention mitigates chronic hypertension during pregnancy in spontaneously hypertensive rats without adverse effects on pregnancy outcomes

Background: Chronic hypertension during pregnancy is a significant concern, associated with increased risks of maternal-fetal morbidity and mortality. Epigallocatechin gallate (EGCG), a compound known for its cardioprotective properties, has gained attention as a potential health supplement due to its favorable safety profile. Objective: This study aims to investigate the effects of maternal EGCG supplementation on elevated blood pressure and pregnancy outcomes in a rodent model of chronic hypertension, specifically using spontaneously hypertensive rats (SHR). Furthermore, the study explores the influence of maternal EGCG supplementation on the blood pressure of SHR offspring during early postnatal development. Methods: SHR dams received oral EGCG at 30 mg/kg body weight. Systolic blood pressure (SBP) monitored weekly throughout gestation period and until postpartum day 21. Pregnancy outcomes - litter size, pup viability, and birth weights - were recorded. SBP in weaned SHR offspring was monitored from 5 to 13 weeks of age to assess long-term effects of maternal EGCG treatment. Daily cage-side observations evaluated general health, behavior, and signs of toxicity. Plasma levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea, and creatinine were analyzed to evaluate liver and kidney function. Results: EGCG treatment in SHR dams progressively reduced maternal SBP throughout gestation and the postpartum period. However, EGCG administration did not affect pregnancy outcomes (gestation duration, litter size, and birth weights). Markers of liver and kidney function (ALT, AST, urea, and creatinine) showed no signs of organ injury in EGCG-treated groups. Contrary to expectations, SBP in SHR offspring exposed to perinatal EGCG did not decrease compared to control groups, indicating maternal EGCG did not alter the offspring's hypertension predisposition. Conclusion: Maternal EGCG supplementation effectively lowered blood pressure in hypertensive dams without compromising pregnancy outcomes or causing liver and kidney damage. These findings suggest that EGCG may be a safe cardioprotective supplement during pregnancy. However, perinatal EGCG exposure did not alter the inherent genetic predisposition to hypertension in SHR offspring. Keywords: Theaceae; Camellia sinensis; green tea; catechins, EGCG; hypertension, pregnancy outcomes, perinatal, spontaneously hypertensive rats, chronic hypertension during pregnancy

Dendritic cell mineralocorticoid receptor controls blood pressure by regulating T helper 17 differentiation: role of the Plcβ1/4-Stat5-NF-κB pathway.

Dendritic cells (DCs) are closely related to blood pressure (BP) regulation. Mineralocorticoid receptor (MR) is an important drug target for antihypertensive treatment. However, the role of DC MR in the pathogenesis of hypertension has not been fully elucidated. This study aimed to determine the role of DC MR in BP regulation and to explore the mechanism. Renal biopsy and peripheral blood samples were collected from hypertensive patients (HTN) for immunostaining and flow cytometry. Dendritic cell MR knockout (DCMRKO) mice, DC MR overexpressing (DCMROV) mice, DCMROV/IL-17A knockout (DCMROV/IL-17AKO) mice and finerenone-treated C57BL/6 mice were infused with angiotensin II (Ang II) to establish hypertensive models. Western blotting, chromatin immunoprecipitation, co-immunoprecipitation, and in vivo DC depletion or adoptive transfer were used to delineate the functional importance of DC MR in hypertension development. Mineralocorticoid receptor antagonists (spironolactone and finerenone) suppressed DC aggregation and activation, as well as hypertension in HTN and mice. Compared with littermate control (LC) mice, dendritic cell MR knockout mice had strikingly decreased BPs and attenuated target organ damage after Ang II infusion. Flow cytometry showed that DC MR deficiency mitigated Ang II-induced DC activation and T helper 17 (Th17) cell differentiation. RNA sequencing revealed that MR-deficient DCs had elevated expression of Plcβ1 and Plcβ4, knockdown of which reversed the inhibitory effect of MR deficiency on DC activation and Th17 differentiation. Adoptive transfer of MR-deficient DCs protected Ang II-induced hypertension, whereas knockdown of Plcβ1/4 eliminated the protective effects. At the molecular level, MR negatively regulated Plcβ1/4, which recruited SHP-1 to inactivate of Stat5 activity, resulting in enhanced NF-κB activation and Th17 polarization. Furthermore, DCMROV mice manifested more elevated BPs and target organ damage than control mice after Ang II infusion, and these differences were abolished in DCMROV/IL-17AKO mice. Finally, MR antagonists decreased the aggregation of Th17 in HTN and mice. Dendritic cell MR plays important roles in the pathogenesis of hypertension by regulating Th17 through Plcβ1/4-Stat5-NF-κB signalling, and blockade of DC MR is beneficial for treating hypertension.

A bovine model of hypoxia-induced pulmonary hypertension reveals a gradient of immune and matrisome response with a complement signature found in circulation.

Pulmonary hypertension (PH) is a progressive vascular disease characterized by vascular remodeling, stiffening, and luminal obstruction, driven by dysregulated cell proliferation, inflammation, and extracellular matrix (ECM) alterations. Despite the recognized contribution of ECM dysregulation to PH pathogenesis, the precise molecular alterations in the matrisome remain poorly understood. In this study, we employed a matrisome-focused proteomics approach to map the protein composition in a young bovine calf model of acute hypoxia-induced PH. Our findings reveal distinct alterations in the matrisome along the pulmonary vascular axis, with the most prominent changes observed in the main pulmonary artery. Key alterations included a strong immune response and wound repair signature, characterized by increased levels of complement components, coagulation cascade proteins, and provisional matrix markers. Additionally, we observed upregulation of ECM-modifying enzymes, growth factors, and core ECM proteins implicated in vascular stiffening, such as collagens, periostin, tenacsin-C, and fibrin(ogen). Notably, these alterations correlated with increased mean pulmonary arterial pressure and vascular remodeling. In the plasma, we identified increased levels of complement components, indicating a systemic inflammatory response accompanying the vascular remodeling. Our findings shed light on the dynamic matrisome remodeling in early-stage PH, implicating a wound-healing trajectory with distinct patterns from the MPA to the distal vasculature. This study provides novel insights into the molecular underpinnings of PH pathogenesis and highlights potential biomarkers and therapeutic targets within the matrisome landscape.

RUNX2 is stabilised by TAZ and drives pulmonary artery calcification and lung vascular remodelling in pulmonary hypertension due to left heart disease.

Calcification is common in chronic vascular disease, yet its role in pulmonary hypertension due to left heart disease is unknown. Here, we probed for the role of runt-related transcription factor-2 (RUNX2), a master transcription factor in osteogenesis, and its regulation by the HIPPO pathway transcriptional coactivator with PDZ-binding motif (TAZ) in the osteogenic reprogramming of pulmonary artery smooth muscle cells and vascular calcification in patients with pulmonary hypertension due to left heart disease. We similarly examined its role using an established rat model of pulmonary hypertension due to left heart disease induced by supracoronary aortic banding. Pulmonary artery samples were collected from patients and rats with pulmonary hypertension due to left heart disease. Genome-wide RNA sequencing was performed, and pulmonary artery calcification assessed. Osteogenic signalling via TAZ and RUNX2 was delineated by protein biochemistry. In vivo, the therapeutic potential of RUNX2 or TAZ inhibition by CADD522 or verteporfin was tested in the rat model. Gene ontology term analysis identified significant enrichment in ossification and osteoblast differentiation genes, including RUNX2, in pulmonary arteries of patients and lungs of rats with pulmonary hypertension due to left heart disease. Pulmonary artery calcification was evident in both patients and rats. Both TAZ and RUNX2 were upregulated and activated in pulmonary artery smooth muscle cells of patients and rats. Co-immunoprecipitation revealed a direct interaction of RUNX2 with TAZ in pulmonary artery smooth muscle cells. TAZ inhibition or knockdown decreased RUNX2 abundance due to accelerated RUNX2 protein degradation rather than reduced de novo synthesis. Inhibition of either TAZ or RUNX2 attenuated pulmonary artery calcification, distal lung vascular remodelling and pulmonary hypertension development in the rat model. Pulmonary hypertension due to left heart disease is associated with pulmonary artery calcification that is driven by TAZ-dependent stabilisation of RUNX2, causing osteogenic reprogramming of pulmonary artery smooth muscle cells. The TAZ-RUNX2 axis may present a therapeutic target in pulmonary hypertension due to left heart disease.

GSDMD Mediates Ang II-Induced Hypertensive Nephropathy by Regulating the GATA2/AQP4 Signaling Pathway.

Hypertensive nephropathy is a common complication of hypertension. However, no effective measures are currently available to prevent the progression of renal insufficiency. Gasdermin D (GSDMD) is a crucial mediator of pyroptosis that induces an excessive inflammatory response. In the present study, we aimed to determine the effect of GSDMD on the pathogenesis of hypertensive nephropathy, which may provide new insights into the treatment of hypertensive nephropathy. C57BL/6 (wild-type, WT) and Gsdmd knockout (Gsdmd-/-) mice were subcutaneously infused with angiotensin II (Ang II) via osmotic mini-pumps to establish a hypertensive renal injury model. Recombinant adeno-associated virus serotype 9 (AAV9) carrying GSDMD cDNA was used to overexpress GSDMD. Renal function biomarkers, histopathological changes, and inflammation and fibrosis indices were assessed. Transcriptome sequencing (RNA-seq) and cleavage under targets and mentation (CUT & Tag) experiments were performed to identify the downstream pathogenic mechanisms of GSDMD in hypertensive nephropathy. GSDMD was activated in the kidneys of mice induced by Ang II (P < 0.001). This activation was primarily observed in the renal tubular epithelial cells (P < 0.0001). GSDMD deficiency attenuated renal injury and fibrosis induced by Ang II (P < 0.0001), whereas Gsdmd overexpression promoted renal injury and fibrosis (P < 0.01). Mechanistically, GSDMD increased Ang II-induced GATA binding protein 2 (GATA2) transcription factor expression (P < 0.01). GATA2 also bound to the aquaporin 4 (Aqp4) promoter sequence and facilitated Aqp4 transcription (P < 0.001), leading to renal injury and fibrosis. Moreover, treatment with GI-Y1, an inhibitor of GSDMD, alleviated Ang II-induced renal injury and fibrosis (P < 0.01). GSDMD plays an important role in the development of hypertensive nephropathy. Targeting GSDMD may be a therapeutic strategy for the treatment of hypertensive nephropathy.

Multi-modal Ultrafast Sonography Microscopy (MUSM) for super-resolution imaging of cerebral vascular dynamics in a mouse model of hypertension induced by Angiotensin-II and L-NAME

Multi-modal Ultrafast Sonography Microscopy (MUSM) for super-resolution imaging of cerebral vascular dynamics in a mouse model of hypertension induced by Angiotensin-II and L-NAME

Nyctanthes arbor-tristis Improves Blood Pressure via Endothelial Pathway: In Silico, Ex Vivo, and In Vivo Evidence.

Systemic hypertension, a common metabolic disorder, poses significant health risks despite the availability of antihypertensive drugs. Nyctanthes arbor-tristis has garnered increasing attention for its perceived efficacy and safety, though its mechanisms of action and the bioactive compounds responsible for its antihypertensive effects remain elusive. Therefore, this study aims to elucidate the antihypertensive activity of N. arbor-tristis leaves in rats and explore associated mechanism through in silico, in vitro, ex vivo, and in vivo studies. The methanolic extract of N. arbor-tristis leaves (MENAT) was fractionated and subjected to qualitative and quantitative phytochemical screening, including total phenolic content (Folin-Ciocalteu method), total flavonoid content (Aluminum chloride method), and total alkaloid content (spectrometric method). Antioxidant studies were conducted using DPPH, FRAP, and H2O2 assays. The most promising fraction (WNAT) was analyzed using LC-MS, and the identified compounds were used for molecular docking studies against cGMP and eNOS. Further, aortic ring assays were conducted to assess ex vivo vasorelaxant activity (rat aortic strip assay) and the underlying mechanisms of WNAT. Later, in vivo studies using a DOCA-salt-induced hypertension model in Wistar rats, along with molecular analyses (RT-PCR), were performed to validate the antihypertensive claims of N. arbor-tristis. In vitro studies demonstrated that the water extract of N. arbor-tristis leaves (WNAT) exhibited strong antioxidant activity and contained key phytochemicals. LC-MS analysis revealed the presence of 19 major compounds, including betulinic acid and arbortristosides. Molecular docking studies indicated that arborside C exhibited a strong affinity for both eNOS and cGMP. Ex vivo studies involving rat aortic strips showed that WNAT induced vasodilatory activity, which is associated with parasympathetic and nitric oxide-related pathways. In vivo experiments further supported WNAT's antihypertensive properties through improvements via amelioration of rat blood pressure and histological features, biochemical markers, morphometric parameters, and gene expression in hypertensive rats. In conclusion, WNAT effectively lowers blood pressure through modulation of the endothelial pathway and warrants further studies to attain its clinical utility in hypertensive subjects.