Angiotensin II Signal Transduction: An Update on Mechanisms of Physiology and Pathophysiology

Dan-shen Yin attenuates myocardial fibrosis after myocardial infarction in rats: Molecular mechanism insights by integrated transcriptomics and network pharmacology analysis and experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

Dan-shen Yin (DSY) originated from the "Shi Fang Ge Kuo" is a Chinese formula composed of three medicines: Salvia miltiorrhiza (Dan-shen), Santalum album L. (Tan-xiang) and Amomum villosum Lour. (Sha-ren). It has many years of clinical experience in the prevention of myocardial fibrosis (MF). However, the specific mechanism of DSY in prevent MF is not clear.

AIM OF THE STUDY

This study aimed to assess the efficacy of DSY in the prevention of MF and reveal its underlying mechanism in a rat model of MF after myocardial infarction (MI) induced by ligation of the left anterior descending branch (LAD) of the coronary artery.

MATERIALS AND METHODS

The blood-entry components of DSY were analyzed by UHPLC-Q-TOF-MS/MS. LAD-ligated rats were used to assess the efficacy of DSY in the prevention of MF. Network pharmacology and transcriptomics analysis were used to predict possible target signaling pathways of DSY in MF. Echocardiography, immunohistochemistry and ELISA methods were used to evaluate the cardiac functions and biochemical changes of the rats. The mRNA expressions of target genes were measured by RT-qPCR. The proteins expressions, including Collagen I, Collagen III, α-smooth muscle actin (α-SMA), matrix metallopeptidase 2 (MMP 2), matrix metallopeptidase 9 (MMP 9), transforming growth factor-β (TGF-β), protein kinase B (AKT), phospho-AKT, extracellular regulated protein kinases (ERK), phospho-ERK, c-Jun N-terminal kinase (JNK), phospho-JNK, mothers against decapentaplegic protein (Smad3), and phospho-Smad3 were detected and quantified by Western Blot.

RESULTS

UHPLC-Q-TOF-MS/MS analysis disclosed that 20 components within DSY could be absorbed into blood of rats. DSY improved myocardial injury in the myocardial tissue of LAD-ligated rats, as evidenced by the elevation of left ventricular ejection fraction and left ventricular fractional shortening, and the decrease of the serum CK-MB and LDH levels. Network pharmacology and transcriptomics predicted that DSY could interfere biological processes, such as extracellular matrix organization, focal adhesion and ECM-receptor interaction, and modulate TGF-β mediated signaling pathways, including PI3K/AKT, MAPK, and Smad3. Further study confirmed that DSY reduced MF, accompanied by reduced TGF-β, Collagen I, Collagen III, α-SMA, MMP 2 and MMP 9. Moreover, DSY repressed the phosphorylation of AKT, MAPKs and Smad3. In addition, DSY reduced inflammation and suppressed the mRNA expressions of IL-1β, IL-6, TNF-α, COX2 and iNOS in MF rats.

CONCLUSIONS

Our study demonstrated that DSY prevented MF in vivo, the action of which was probably via reducing extracellular matrix organization, focal adhesion ECM-receptor interaction and inflammation by regulating TGF-β mediated PI3K/AKT, MAPK and Smad signaling pathways.

Accuracy study of Angiotensin 1-7 composite index test to predict pulmonary fibrosis and guide treatment

BACKGROUND

Pulmonary fibrosis can develop after acute respiratory distress syndrome (ARDS). The hypothesis is we are able to measure phenotypes that lie at the origin of ARDS severity and fibrosis development. The aim is an accuracy study of prognostic circulating biomarkers.

METHODS

A longitudinal study followed COVID-related ARDS patients with medical imaging, pulmonary function tests and biomarker analysis, generating 444 laboratory data. Comparison to controls used non-parametrical statistics; p < 0·05 was considered significant. Cut-offs were obtained through receiver operating curve. Contingency tables revealed predictive values. Odds ratio was calculated through logistic regression.

RESULTS

Angiotensin 1-7 beneath 138 pg/mL defined Angiotensin imbalance phenotype. Hyper-inflammatory phenotype showed a composite index test above 34, based on high Angiotensin 1-7, C-Reactive Protein, Ferritin and Transforming Growth Factor-β. Analytical study showed conformity to predefined goals. Clinical performance gave a positive predictive value of 95 % (95 % confidence interval, 82 %-99 %), and a negative predictive value of 100 % (95 % confidence interval, 65 %-100 %). Those severe ARDS phenotypes represented 34 (Odds 95 % confidence interval, 3-355) times higher risk for pulmonary fibrosis development (p < 0·001).

CONCLUSIONS

Angiotensin 1-7 composite index is an early and objective predictor of ARDS evolving to pulmonary fibrosis. It may guide therapeutic decisions in targeted phenotypes.

The influence of PM2.5 exposure on SARS-CoV-2 infection via modulating the expression of angiotensin converting enzyme II

Particulate matter 2.5 (PM2.5) pollution and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic are the greatest environmental health issues worldwide. Several statistics revealed the significant positive correlation between the morbidity of coronavirus disease-19 (COVID-19) and the levels of air pollution. Nevertheless, there is no direct experimental evidence to indicate the effect of PM2.5 exposure on SARS-CoV-2 infection. The objective of this study was to evaluate whether the infection of SARS-CoV-2 affected by PM2.5 through angiotensin-converting enzyme II (ACE2) expression enhances and investigate the function of ACE2 in lung injury induced by PM2.5. An animal model of PM2.5-induced lung injury was established using wild-type (WT, C57BL/6), human ACE2 transgenic (K18-hACE2 TG), and murine ACE2 gene knockout (mACE2 KO) mice. The results indicate that PM2.5 exposure facilitates SARS-CoV-2 infection through inducing ACE2 expression in vitro (10 μg/mL) and in vivo (6.25 mg/kg/day in 50 μL saline). The levels of ACE, inflammatory cytokines, and mitogen-activated protein kinase (MAPK) proteins in WT, K18-hACE TG and mACE2 KO mice were significantly increased after PM2.5 instillation. The severest PM2.5-induced lung damage was observed in mACE2 KO mice. In summary, ACE2 plays a double-edged sword role in lung injury, PM2.5 exposure contributed to SARS-CoV-2 infection through inducing ACE2 expression, but ACE2 also protected pulmonary inflammation from PM2.5 challenge.

Unveiling the molecular and cellular links between obstructive sleep apnea-hypopnea syndrome and vascular aging

ABSTRACT

Vascular aging (VA) is a common etiology of various chronic diseases and represents a major public health concern. Intermittent hypoxia (IH) associated with obstructive sleep apnea-hypopnea syndrome (OSAHS) is a primary pathological and physiological driver of OSAHS-induced systemic complications. A substantial proportion of OSAHS patients, estimated to be between 40% and 80%, have comorbidities such as hypertension, heart failure, coronary artery disease, pulmonary hypertension, atrial fibrillation, aneurysm, and stroke, all of which are closely associated with VA. This review examines the molecular and cellular features common to both OSAHS and VA, highlighting decreased melatonin secretion, impaired autophagy, increased apoptosis, increased inflammation and pyroptosis, increased oxidative stress, accelerated telomere shortening, accelerated stem cell depletion, metabolic disorders, imbalanced protein homeostasis, epigenetic alterations, and dysregulated neurohormonal signaling. The accumulation and combination of these features may underlie the pathophysiological link between OSAHS and VA, but the exact mechanisms by which OSAHS affects VA may require further investigation. Taken together, these findings suggest that OSAHS may serve as a novel risk factor for VA and related vascular disorders, and that targeting these features may offer therapeutic potential to mitigate the vascular risks associated with OSAHS.

Protease-activated receptor 2 deficient mice develop less angiotensin II induced left ventricular hypertrophy but more cardiac fibrosis

AIMS

Activation of Protease Activated Receptor 2 (PAR2) has been shown to be involved in regulation of injury-related processes including inflammation, fibrosis and hypertrophy. In this study we will investigate the role of PAR2 in cardiac injury in a mouse model of hypertension using continuous infusion with angiotensin II.

METHODS

Hypertension was induced in 12 weeks old wildtype (wt, n = 8) and PAR2 deficient mice (n = 9) by continuous infusion with angiotensin II for 4 weeks using osmotic minipumps. At the end, hearts were collected for analysis of left ventricular hypertrophy (LVH), myocardial capillary supply, fibrosis and localization of PAR2 expression using histological, immunohistological and mRNA expression analysis techniques. In addition, rat cardiac fibroblasts were treated with angiotensin II and PAR2 was inhibited by a blocking antibody and the PAR2 inhibitor AZ3451.

RESULTS

Cardiac PAR2 mRNA expression was downregulated by 40±20% in wt mice treated with AngII compared to untreated controls. Four weeks after AngII treatment, LVH was significantly increased in AngII-treated wt mice compared to similarly treated PAR2-deficient animals as determined by relative heart weight, left ventricular cross-sectional area, and analysis of ventricular lumen area determined on sections. Treatment of wt mice resulted in an approximately 3-fold increase in cardiac expression of FGF23, which was 50% lower in PAR2-deficient animals compared to wt animals and therefore no longer significantly different from expression levels in untreated control mice. In contrast, cardiac interstitial fibrosis was significantly higher in PAR2-deficient mice compared to similar treated wt controls, as assessed by Sirius Red staining (>3-fold) and collagen IV staining (>2-fold). Additional experiments with isolated cardiac fibroblasts showed induction of pro-fibrotic genes when treated with PAR2 inhibitors.

CONCLUSION

In angiotensin II-induced cardiac injury, PAR2 deficiency has an ambivalent effect, enhancing fibrosis on the one hand, but reducing LVH on the other.

Spinal AT1R contributes to neuroinflammation and neuropathic pain via NOX2-dependent redox signaling in microglia

Microglia-mediated neuroinflammation demonstrates a crucial act in the progression of neuropathic pain. Oxidative damage induced by reactive oxygen species (ROS) derived from NADPH oxidase (NOX) in microglia drives proinflammatory microglia activation. Recent evidence points to the central renin angiotensin system (RAS) is involved in oxidative stress and neuroinflammation, with the angiotensin converting enzyme/angiotensin II/angiotensin receptor-1 (ACE/Ang II/AT1R) axis promoting inflammation through increased ROS production, counteracted by the ACE2/Ang (1-7)/Mas receptor (MasR) axis. While interventions targeting spinal AT1R have been shown to alleviate nociceptive hypersensitivity; yet the mechanisms remain elusive. Here, we discovered that spared nerve injury (SNI)-induced mechanical allodynia in rats were associated with M1-like microglia activation, oxidative stress and overactivity of ACE/Ang II/AT1R axis in the spinal cord. Increased AT1R and NOX2 expression were observed in activated dorsal horn microglia following SNI. Blockade of AT1R with losartan potassium (LOP) suppressed NOX2-mediated oxidative stress, and promoted a shift in microglia from the proinflammatory M1 phenotype to the anti-inflammatory M2 phenotype in LPS-treated BV-2 cells. Additionally, NOX2 overexpression triggered the activation of the high-mobility group box 1/nuclear factor-kappa B (HMGB1/NF-κB) signaling pathway. Intrathecal administration of LOP effectively inhibited SNI-induced NOX2 overactivation in microglia and suppressed the HMGB1/NF-kB pathway, reducing oxidative stress and shifting the microglia polarization from M1 to M2 in the spinal cord, thereby attenuating neuroinflammation and pain hypersensitivity. Collectively, these findings underscore the neuroimmune-modulating effects of spinal AT1R in neuropathic pain, highlighting the regulation of redox homeostasis in microglia via a NOX2 dependent mechanism.

Pathophysiology of Angiotensin II-Mediated Hypertension, Cardiac Hypertrophy, and Failure: A Perspective from Macrophages

Heart failure is a complex syndrome characterized by cardiac hypertrophy, fibrosis, and diastolic/systolic dysfunction. These changes share many pathological features with significant inflammatory responses in the myocardium. Among the various regulatory systems that impact on these heterogeneous pathological processes, angiotensin II (Ang II)-activated macrophages play a pivotal role in the induction of subcellular defects and cardiac adverse remodeling during the progression of heart failure. Ang II stimulates macrophages via its AT1 receptor to release oxygen-free radicals, cytokines, chemokines, and other inflammatory mediators in the myocardium, and upregulates the expression of integrin adhesion molecules on both monocytes and endothelial cells, leading to monocyte-endothelial cell-cell interactions. The transendothelial migration of monocyte-derived macrophages exerts significant biological effects on the proliferation of fibroblasts, deposition of extracellular matrix proteins, induction of perivascular/interstitial fibrosis, and development of hypertension, cardiac hypertrophy and heart failure. Inhibition of macrophage activation using Ang II AT1 receptor antagonist or depletion of macrophages from the peripheral circulation has shown significant inhibitory effects on Ang II-induced vascular and myocardial injury. The purpose of this review is to discuss the current understanding in Ang II-induced maladaptive cardiac remodeling and dysfunction, particularly focusing on molecular signaling pathways involved in macrophages-mediated hypertension, cardiac hypertrophy, fibrosis, and failure. In addition, the challenges remained in translating these findings to the treatment of heart failure patients are also addressed.

Therapeutic opportunities in targeting the protective arm of the renin-angiotensin system to improve insulin sensitivity: a mechanistic review

In recent years, the knowledge of the physiological and pathophysiological roles of the renin-angiotensin system (RAS) in glucose metabolism has advanced significantly. It is now well-established that blockade of the angiotensin AT1 receptor (AT1R) improves insulin sensitivity. Activation of the AT2 receptor (AT2R) and the MAS receptor are significant contributors to this beneficial effect. Elevated availability of angiotensin (Ang) II) for interaction with the AT2R and increased Ang-(1-7) formation during AT1R blockade mediate these effects. The ongoing development of selective AT2R agonists, such as compound 21 and the novel Ang III peptidomimetics, has significantly advanced the exploration of the role of AT2R in metabolism and its potential as a therapeutic target. These agents show promise, particularly when RAS inhibition is contraindicated. Additionally, other RAS peptides, including Ang IV, des-Asp-Ang I, Ang-(1-9), and alamandine, hold therapeutic capability for addressing metabolic disturbances linked to type 2 diabetes. The possibility of AT2R heteromerization with either AT1R or MAS receptor offers an exciting area for future research, particularly concerning therapeutic strategies to improve glycemic control. This review focuses on therapeutic opportunities to improve insulin sensitivity, taking advantage of the protective arm of the RAS.

Implications of β-Arrestin biased signaling by angiotensin II type 1 receptor for cardiovascular drug discovery and therapeutics

Angiotensin II receptors, Type 1 (AT1R) and Type 2 (AT2R) are 7TM receptors that play critical roles in both the physiological and pathophysiological regulation of the cardiovascular system. While AT1R blockers (ARBs) have proven beneficial in managing cardiac, vascular and renal maladies they cannot completely halt and reverse the progression of pathologies. Numerous experimental and animal studies have demonstrated that β-arrestin biased AT1R-ligands (such as SII-AngII, S1I8, TRV023, and TRV027) offer cardiovascular benefits by blocking the G protein signaling while retaining the β-arrestin signaling. However, these ligands failed to show improvement in heart-failure outcome over the placebo in a phase IIb clinical trial. One major limitation of current β-arrestin biased AT1R-ligands is that they are peptides with short half-lives, limiting their long-term efficacy in patients. Additionally, β-arrestin biased AT1R-ligand peptides, may inadvertently block AT2R, a promiscuous receptor, potentially negating its beneficial effects in post-myocardial infarction (MI) patients. Therefore, developing a small molecule β-arrestin biased AT1R-ligand with a longer half-life and specificity to AT1R could be more effective in treating heart failure. This approach has the potential to revolutionize the treatment of cardiovascular diseases by offering more sustained and targeted therapeutic effects.

Cardiomyocyte-derived small extracellular vesicle-transported let-7b-5p modulates cardiac remodeling via TLR7 signaling pathway

Cardiac remodeling is the major pathological change of heart failure. And let-7 family has been implicated in the development and pathogenesis of cardiovascular diseases. However, the mechanisms underlying let-7b-5p-mediated cellular pathogenesis of cardiac remodeling are not well understood. The present study aimed to explore the effects of let-7b-5p on cardiac remodeling and the corresponding regulatory mechanism. In vivo results indicated that cardiac let-7b-5p was upregulated in the mouse model of Angiotensin II (Ang II)-induced cardiac remodeling. Additionally, let-7b-5p knockdown ameliorated the effects of Ang II-induced cardiac remodeling, whereas let-7b-5p overexpression facilitated cardiac remodeling. In vitro, let-7b-5p mimics induced cardiomyocyte hypertrophy, fibroblast transdifferentiation, and the expression of inflammatory factors in neonatal mouse cardiomyocytes (NMCMs), neonatal mouse cardiac fibroblasts (NMCFs), and bone marrow-derived macrophages (BMDMs), respectively. Furthermore, let-7b-5p exerted its cardiac pro-remodeling effects at least partially through a small extracellular vesicle (SEV)-based delivery strategy. We found that let-7b-5p was enriched in SEVs derived from Ang II-treated NMCMs (NMCM-SEV) but not from Ang II-treated NMCFs (NMCF-SEV). Mechanistic analyses revealed that NMCM-SEV promoted TLR7 and MyD88 expression, which increased NF-κB phosphorylation levels. Knockdown of let-7b-5p, TLR7 or MyD88 in NMCMs, NMCFs, and BMDMs abolished the cardiac pro-remodeling effects of NMCM-SEV. These results uncover that let-7b-5p-containing NMCM-SEVs promote cardiac remodeling via the TLR7/MyD88/NF-κB pathway, implicating let-7b-5p as a potential therapeutic target for heart failure.

Endothelial FOSL1 drives angiotensin II-induced myocardial injury via AT1R-upregulated MYH9

Vascular remodeling represents a pathological basis for myocardial pathologies, including myocardial hypertrophy and myocardial infarction, which can ultimately lead to heart failure. The molecular mechanism of angiotensin II (Ang II)-induced vascular remodeling following myocardial infarction reperfusion is complex and not yet fully understood. In this study, we examined the effect of Ang II infusion on cardiac vascular remodeling in mice. Single-cell sequencing showed Ang II induced cytoskeletal pathway enrichment and that FOS like-1 (FOSL1) affected mouse cardiac endothelial dysfunction by pseudotime analysis. Myosin heavy chain 9 (MYH9) was predominantly expressed in primary cardiac endothelial cells. The Ang II type I receptor blocker telmisartan and the protein kinase C inhibitor staurosporine suppressed Ang II-induced upregulation of MYH9 and FOSL1 phosphorylation in human umbilical vein endothelial cells. Silencing MYH9 abolished Ang II-mediated inhibition of angiogenesis in human umbilical vein endothelial cells, and attenuated AngII-induced vascular hyperpermeability. We found that FOSL1 directly bound to the MYH9 promoter and thus activated transcription of MYH9 by the dual luciferase reporter and chromatin immunoprecipitation assays, leading to vascular dysfunction. In vivo, 6 weeks after injecting adeno-associated virus-ENT carrying the TEK tyrosine kinase (tie) promoter-driven short hairpin RNA for silencing FOSL1 (AAV-tie-shFOSL1), cardiac function represented by the ejection fraction and fractional shortening was improved, myocardial fibrosis was decreased, protein levels of phosphorylated FOSL1, MYH9, and collagen type I alpha were reduced, and cardiac vascular density was recovered in mice with endothelial Fosl1-specific knockdown in Ang II-infused mice. In ischemia-reperfusion mice, AAV-shFosl1 mice had a reduced infarct size and preserved cardiac function compared with control AAV mice. Our findings suggest a critical role of the FOSL1/MYH9 axis in hindering Ang II-induced vascular remodeling, and we identified FOSL1 as a potential therapeutic target in endothelial cell injuries induced by myocardial ischemia-reperfusion.

Transgenic rat with ubiquitous expression of angiotensin-(1-7)-producing fusion protein: a new tool to study the role of protective arm of the renin-angiotensin system in the pathophysiology of cardio-renal diseases

The aim of the present study was to assess systemic circulatory and tissue activities of both the classical arm and of the alternative arm of the renin-angiotensin system (RAS) in a new transgenic rat line (TG7371) that expresses angiotensin-(1-7) (ANG 1-7)-producing fusion protein; the results were compared with the activities measured in control transgene-negative Hannover Sprague-Dawley (HanSD) rats. Plasma and tissue concentrations of angiotensin II (ANG II) and ANG 1-7, and kidney mRNA expressions of receptors responsible for biological actions of ANG II and ANG 1-7 [i.e. ANG II type 1 and type 2 (AT1 and AT2) and Mas receptors] were assessed in TG7371 transgene-positive and in HanSD rats. We found that male TG7371 transgene-positive rats exhibited significantly elevated plasma, kidney, heart and lung ANG 1-7 concentrations as compared with control male HanSD rats; by contrast, there was no significant difference in ANG II concentrations and no significant differences in mRNA expression of AT1, AT2 and Mas receptors. In addition, we found that in male TG7371 transgene-positive rats blood pressure was lower than in male HanSD rats. These data indicate that the balance between the classical arm and the alternative arm of the RAS was in male TGR7371 transgene-positive rats markedly shifted in favor of the latter. In conclusion, TG7371 transgene-positive rats represent a new powerful tool to study the long-term role of the alternative arm of the RAS in the pathophysiology and potentially in the treatment of cardio-renal diseases.

Continuous infusion of resolvin D2 in combination with Angiotensin-II show contrary effects on blood pressure and intracardiac artery remodeling

Specialized pro-resolving mediators (SPMs) are key effectors of resolution of inflammation. This is highly relevant for cardiac and vessel remodeling, where the net inflammatory response contributes to determine disease outcome. Herein, we used a mice model of angiotensin (Ang)-II-induced hypertension to study the effect of the SPM Resolvin D2 (RvD2), on hypertension and cardiac remodeling. By using subcutaneous osmotic minipumps, mice were treated with PBS or Ang-II in combination with or without RvD2 for two weeks. Mice receiving RvD2 gained less blood pressure increase compared to Ang-II alone. Surprisingly, however, examination of intracardiac arteries revealed that RvD2 treatment in combination with Ang-II exacerbated Ang-II-induced fibrosis. Measures of vascular smooth muscle cell dedifferentiation correlated with the level of vascular remodeling, indicating that this dedifferentiation, including increased proliferation and migration, is a contributing factor. RNA sequencing of left ventricle cardiac tissue supported these findings as pathways related to cell proliferation and cell differentiation were upregulated in mice treated with Ang-II in combination with RvD2. Additionally, the RNA sequencing also showed upregulation of pathways related to SPM metabolism. In line with this, Mass spectrometry analysis of lipid mediators showed reduced cardiac levels of the arachidonic acid derived metabolite leukotriene E4 in RvD2 treated mice. Our study suggests that continuous infusion through osmotic minipumps should not be the recommended route of RvD2 administration in future studies.

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

Aim

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.

Methods

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.

Results

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).

Conclusion

GSDMD plays an important role in the development of hypertensive nephropathy. Targeting GSDMD may be a therapeutic strategy for the treatment of hypertensive nephropathy.

Angiotensin II-Type-1a Receptor and Renal K + Wasting during Overnight Low-Na + Intake

Key Points

Angiotensin II–type-1a-receptor in the distal convoluted tubule (DCT) plays a role in regulating sodium transport in the DCT. Angiotensin II–type-1a-receptor in the DCT plays a role in maintaining potassium homeostasis during sodium restriction.

Background

Chronic angiotensin II perfusion stimulates Kir4.1/Kir5.1 of the distal convoluted tubule (DCT) via angiotensin II–type-1a-receptor (AT1aR), and low‐sodium intake also stimulates Kir4.1/Kir5.1. However, the role of AT1aR in mediating the effect of low salt on Kir4.1/Kir5.1 is not explored.

Methods

We used the patch-clamp technique to examine Kir4.1/Kir5.1 activity of the DCT, employed immunoblotting to examine Na-Cl cotransporter (NCC) expression/activity, and used the in vivo perfusion technique to measure renal Na+ and renal K+ excretion in control, kidney tubule–specific–AT1aR-knockout mice (Ks-AT1aR-KO) and DCT-specific–AT1aR-knockout mice (DCT-AT1aR-KO).

Results

Angiotensin II acutely stimulated the 40-pS-K+ channel (Kir4.1/Kir5.1-heterotetramer) and increased whole-cell Kir4.1/Kir5.1-mediated K+ currents and the negativity of DCT membrane potential only in late DCT2 but not in early DCT. Acute angiotensin II increased thiazide-induced renal Na+ excretion (ENa). The effect of angiotensin II on Kir4.1/Kir5.1 and hydrochlorothiazide-induced ENa was absent in Ks-AT1aR-KO mice. Overnight low-salt intake stimulated the expression of Agtr1a mRNA in DCT, increased whole-cell Kir4.1/Kir5.1-mediated K+ currents in late DCT, hyperpolarized late DCT membrane, augmented the expression of phosphor-Na-Cl-cotransporter, and enhanced thiazide-induced renal-ENa in the control mice. However, the effect of overnight low-salt intake on Kir4.1/Kir5.1 activity, DCT membrane potential, and NCC activity/expression was abolished in DCT-AT1aR-KO or Ks-AT1aR-KO mice. Overnight low-salt intake had no effect on baseline renal K+ excretion (EK) and plasma K+ concentrations in the control mice, but it increased baseline renal-EK and decreased plasma K+ concentrations in DCT-AT1aR-KO or in Ks-AT1aR-KO mice.

Conclusions

Acute angiotensin II or overnight low-salt intake stimulated Kir4.1/Kir5.1 in late DCT, and AT1aR was responsible for acute angiotensin II or overnight low-salt intake–induced stimulation of Kir4.1/Kir5.1 and NCC. AT1aR of the DCT plays a role in maintaining adequate baseline renal-EK and plasma K+ concentrations during overnight low-salt intake.

Characterizations of angiotensin-converting enzyme-2 (ACE2) peptidase activity

Angiotensin (Ang) II (1-8) is a potent vasoconstrictor known for its role in hypertension. Angiotensin-converting enzyme (ACE2) converts Ang II (1-8) to a vasodilator Ang (1-7) by removing the carboxy-terminal Phe. ACE2 more recently gained attention as the receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that caused the coronavirus disease 2019 (COVID-19) pandemic. Given the pathophysiological importance of ACE2, the present study examined the mechanism of ACE2 catalytic activity by comparing the ability of angiotensin molecules of various lengths to compete with the artificial fluorogenic substrate. The Fluorimetric SensoLyte 390 ACE2 Activity Assay uses an Mca/Dnp fluorescence resonance energy transfer peptide as the substrate. Results showed that the natural substrate Ang II (1-8) competed with the fluorogenic substrate, reducing the fluorescence signals. Deletion of C-terminal Phe resulted in the loss of the ability to compete with the artificial substrate, as shown by the actions of Ang (1-7), Ang (2-7), and Ang (5-7). By contrast, the loss of N-terminal Asp potentiated the ability to compete with the substrate as seen by the action of Ang III (2-8). However, the loss of two amino acids (Asp-Arg) from the N-terminus reduced the ability to compete with the substrate as observed by the actions of Ang IV (3-8) and Ang (5-8). Ang I (1-10) and Ang (1-9) did not strongly compete with the substrate. Interestingly, shorter peptides Ang (1-5) and Ang (1-4) potentiated the ACE2 activity. These results suggest that Ang II and Ang III are the best natural substrates for ACE2.

Nanomedicine regulating PSC-mediated intercellular crosstalk: Mechanisms and therapeutic strategies

Pancreatic fibrosis (PF) is primarily distinguished by the stimulation of pancreatic stellate cells (PSCs) and excessive extracellular matrix deposition, which is the main barrier impeding drug delivery and distribution. Recently, nanomedicine, with efficient, targeted, and controllable drug release characteristics, has demonstrated enormous advantages in the regression of pancreas fibrotic diseases. Notably, paracrine signals from parenchymal and immune cells such as pancreatic acinar cells, islet cells, pancreatic cancer cells, and immune cells can directly or indirectly modulate PSC differentiation and activation. The intercellular crosstalk between PSCs and these cells has been a critical event involved in fibrogenesis. However, the connections between PSCs and other pancreatic cells during the progression of diseases have yet to be discussed. Herein, we summarize intercellular crosstalk in the activation of PSCs and its contribution to the development of common pancreatic diseases, including pancreatitis, pancreatic cancer, and diabetes. Then, we also examine the latest treatment strategies of nanomedicine and potential targets for PSCs crosstalk in fibrosis, thereby offering innovative insights for the design of antifibrotic nanomedicine. Ultimately, the enhanced understanding of PF will facilitate the development of more precise intervention strategies and foster individually tailored therapeutic approaches for pancreatic diseases.

The Role of Ca2+/PI3K/Akt/eNOS/NO Pathway in Astragaloside IV-Induced Inhibition of Endothelial Inflammation Triggered by Angiotensin II

Inflammation induced by angiotensin II (Ang II) is a key event in the progression of numerous cardiovascular diseases. Astragaloside IV (AS-IV), a glycoside extracted from Astragalus membranaceus Bunge, has been shown to inhibit Ang II-induced inflammatory responses in vivo. However, the mechanisms underlying the beneficial effects are still unclear. This study investigated whether AS-IV attenuates endothelial inflammation induced by Ang II via the activation of endothelial nitric oxide synthase (eNOS)/nitric oxide (NO) pathway. Human umbilical vein endothelial cells (HUVECs) were cultured in the presence of AS-IV with or without the specific inhibitor of NOS or Ca2+- and phosphatidylinositol 3-kinase (PI3K)/Akt-dependent cascade prior to Ang II exposure. Incubation of HUVECs with AS-IV enhanced NO production and eNOSser1177 phosphorylation. These responses were abrogated by the inhibition of NOS or Ca2+- and PI3K/Akt-dependent pathway. In addition, preincubation of HUVECs with AS-IV inhibited Ang II-induced cytokine and chemokine production, adhesion molecule expression, monocyte adhesion, and nuclear factor kappa B (NF-κB) activation as evidenced by the attenuation of inhibitor of kappa B alpha phosphorylation and subsequent NF-κB DNA binding. These effects of AS-IV were abolished by the suppression of NOS or Ca2+- and PI3K/Akt-dependent cascade. Our findings indicate that AS-IV attenuates inflammatory responses triggered by Ang II possibly via the activation of Ca2+/PI3K/Akt/eNOS/NO pathway in endothelial cells.

Association between premature vascular smooth muscle cells senescence and vascular inflammation in Takayasu's arteritis

OBJECTIVES

Arterial wall inflammation and remodelling are the characteristic features of Takayasu's arteritis (TAK). It has been proposed that vascular smooth muscle cells (VSMCs) are the main targeted cells of inflammatory damage and participate in arterial remodelling in TAK. Whether VSMCs are actively involved in arterial wall inflammation has not been elucidated. Studies have shown that cellular senescence in tissue is closely related to local inflammation persistence. We aimed to investigate whether VSMCs senescence contributes to vascular inflammation and the prosenescent factors in TAK.

METHODS

VSMCs senescence and senescence-associated secretory phenotype were detected by histological examination, bulk RNA-Seq and single-cell RNA-seq conducted on vascular surgery samples of TAK patients. The key prosenescent factors and the downstream signalling pathway were investigated in a series of in vitro and ex vivo experiments.

RESULTS

Histological findings, primary cell culture and transcriptomic analyses demonstrated that VSMCs of TAK patients had the features of premature senescence and contributed substantially to vascular inflammation by upregulating the expression of senescence-associated inflammatory cytokines. IL-6 was found to be the critical cytokine that drove VSMCs senescence and senescence-associated mitochondrial dysfunction in TAK. Mechanistically, IL-6-induced non-canonical mitochondrial localisation of phosphorylated STAT3 (Tyr705) prevented mitofusin 2 (MFN2) from proteasomal degradation, and subsequently promoted senescence-associated mitochondrial dysfunction and VSMCs senescence. Mitochondrial STAT3 or MFN2 inhibition ameliorated VSMCs senescence in ex vivo cultured arteries of TAK patients.

CONCLUSIONS

VSMCs present features of cellular senescence and are actively involved in vascular inflammation in TAK. Vascular IL-6-mitochondrial STAT3-MFN2 signalling is an important driver of VSMCs senescence.

Gpr55 deficiency crucially alters cardiomyocyte homeostasis and counteracts angiotensin II induced maladaption in female mice

BACKGROUND AND PURPOSE

Cannabis stimulates several G-protein-coupled-receptors and causes bradycardia and hypotension upon sustained consumption. Moreover, in vitro studies suggest an interference of cannabinoid-signalling with cardiomyocyte contractility and hypertrophy. We aimed at revealing a functional contribution of the cannabinoid-sensitive receptor GPR55 to cardiomyocyte homeostasis and neurohumorally induced hypertrophy in vivo.

EXPERIMENTAL APPROACH

Gpr55-/- and wild-type (WT) mice were characterized after 28-day angiotensin II (AngII; 1·μg·kg-1 min-1) or vehicle infusion. In isolated adult Gpr55-/- and WT cardiomyocytes, mitochondrial function was assessed under naïve conditions, while cytosolic Ca2+ handling was additionally determined following application of the selective GPR55 antagonist CID16020046.

KEY RESULTS

Gpr55 deficiency did not affect angiotensin II (AngII) mediated hypertrophic growth, yet, especially in females, it alleviated maladaptive pro-hypertrophic and -inflammatory gene expression and improved inotropy and adrenergic responsiveness compared to WT. In-depth analyses implied increased cytosolic Ca2+ concentrations and transient amplitudes, and accelerated sarcomere contraction kinetics in Gpr55-/- myocytes, which could be mimicked by GPR55 blockade with CID16020046 in female WT cells. Moreover, Gpr55 deficiency up-regulated factors involved in glucose and fatty acid transport independent of the AngII challenge, accelerated basal mitochondrial respiration and reduced basal protein kinase (PK) A, G and C activity and phospholemman (PLM) phosphorylation.

CONCLUSIONS AND IMPLICATIONS

Our study suggests GPR55 as crucial regulator of cardiomyocyte hypertrophy and homeostasis presumably by regulating PKC/PKA-PLM and PKG signalling, and identifies the receptor as potential target to counteract maladaptation, adrenergic desensitization and metabolic shifts as unfavourable features of the hypertrophied heart in females.

Identification of angiogenesis-related genes and molecular subtypes for psoriasis based on random forest algorithm

Psoriasis is a chronic immune-mediated recurrent skin disease causing systemic damage. Increased angiogenesis has been reported to participate in the progression of psoriasis. However, angiogenesis-related genes (ARGs) in psoriasis have not been systematically elucidated. Therefore, we aim to identify potential biomarkers and subtypes using two algorithmsr. Transcriptome sequencing data of patients with psoriasis were obtained, in which differentially expressed genes were assessed by principal component analysis. A diagnostic model was developed using random forest algorithm and validated by receiver operating characteristic (ROC) curves. Subsequently, we performed consensus clustering to calculate angiogenesis-associated molecular subtypes of psoriasis. Additionally, a correlation analysis was conducted between ARGs and immune cell infiltration. Finally, validation of potential ARG genes was performed by quantitative real-time PCR (qRT-PCR). We identified 29 differentially expressed ARGs, including 13 increased and 16 decreased. Ten ARGs, CXCL8, ANG, EGF, HTATIP2, ANGPTL4, TNFSF12, RHOB, PML, FOXO4, and EMCN were subsequently sifted by the diagnostic model based on a random forest algorithm. Analysis of the ROC curve (area under the curve [AUC] = 1.0) indicated high diagnostic performance in internal validation. The correlation analysis suggested that CXCL8 has a high positive correlation with neutrophil (R =0.8, P < 0.0001) and interleukins pathway (R = 0.79, P < 0.0001). Furthermore, two ARG-mediated subtypes were obtained, indicating potential heterogeneity. Finally, the qRT-PCR demonstrated that the mRNA expression levels of CXCL8 and ANGPTL4 were elevated in psoriasis patients, with a reduced expression of EMCN observed. The current paper indicated potential ARG-related biomarkers of psoriasis, including CXCL8, ANGPTL4, and EMCN, with two molecular subtypes.

Maternal Microvascular Dysfunction During and After Preeclamptic Pregnancy

Preeclampsia, a pregnancy disorder characterized by de novo hypertension and maternal multisystem organ dysfunction, is the leading cause of maternal mortality worldwide and is associated with a fourfold greater risk of cardiovascular disease throughout the lifespan. Current understanding of the etiology of preeclampsia remains unclear, due in part to the varying phenotypical presentations of the disease, which has hindered the development of effective and mechanism-specific treatment or prevention strategies both during and after the affected pregnancy. These maternal sequelae of preeclampsia are symptoms of systemic vascular dysfunction in the maternal nonreproductive microvascular beds that drives the development and progression of adverse cardiovascular outcomes during preeclampsia. Despite normalization of vascular disturbances after delivery, subclinical dysfunction persists in the nonreproductive microvascular beds, contributing to an increased lifetime risk of cardiovascular and metabolic diseases and all-cause mortality. Given that women with a history of preeclampsia demonstrate vascular dysfunction despite an absence of traditional CVD risk factors, an understanding of the underlying mechanisms of microvascular dysfunction during and after preeclampsia is essential to identify potential therapeutic avenues to mitigate or reverse the development of overt disease. This article aims to provide a summary of the existing literature on the pathophysiology of maternal microvascular dysfunction during preeclampsia, the mechanisms underlying the residual dysfunction that remains after delivery, and current and potential treatments both during and after the affected pregnancy that may reduce microvascular dysfunction in these high-risk women. © 2024 American Physiological Society. Compr Physiol 14:5703-5727, 2024.

The role of Klotho and sirtuins in sleep-related cardiovascular diseases: a review study

The prevalence of sleep disorders has been reported from 1.6% to 56.0%, worldwide. Sleep deprivation causes cardiovascular diseases (CVDs) including atherosclerosis, vascular aging, hypertension, heart dysfunction, reduced heart rate variability, and cardiac arrhythmia. Reduced tissue oxygen causes various CVDs by activating pro-inflammatory factors and increasing oxidative stress. Sleep disorders are more important and prevalent in older people and cause more severe cardiovascular complications. On the other hand, the reduction of Klotho level, an age-dependent protein whose expression decreases with age, is associated with age-related diseases. Sirtuins, class III histone deacetylases, also are among the essential factors in postponing cellular aging and increasing the lifespan of organisms, and they do this by regulating different pathways in the cell. Sirtuins and Klotho play an important role in the pathophysiology of CVDS and both have anti-oxidative stress and anti-inflammatory activity. Studies have shown that the levels of Klotho and sirtuins are altered in sleep disorders. In this article, alterations of Klotho and sirtuins in sleep disorders and in the development of sleep-related CVDs were reviewed and the possible signaling pathways were discussed. The inclusion criteria were studies with keywords of different types of sleep disorders and CVDs, klotho, SIRT1-7, and sirtuins in PubMed, Scopus, Embase، Science Direct، Web of Sciences and Google Scholar by the end of 2023. The studies revealed there is a bidirectional relationship between sleep disorders and the serum and tissue levels of Klotho and sirtuins and sleep related-CVDs.

Time of day affects MrgD-dependent modulation of cardiomyocyte contractility

The renin-angiotensin system (RAS) is composed of a series of peptides, receptors, and enzymes that play a pivotal role in maintaining cardiovascular homeostasis. Among the most important players in this system are the angiotensin-II and angiotensin-(1-7) peptides. Our group has recently demonstrated that alamandine (ALA), a peptide with structural and functional similarities to angiotensin-(1-7), interacts with cardiomyocytes, enhancing contractility via the Mas-related G protein-coupled receptor member D (MrgD). It is currently unknown whether this modulation varies along the distinct phases of the day. To address this issue, we assessed the ALA-induced contractility response of cardiomyocytes from mice at four Zeitgeber times (ZTs). At ZT2 (light phase), ALA enhanced cardiomyocyte shortening in an MrgD receptor-dependent manner, which was associated with nitric oxide (NO) production. At ZT14 (dark phase), ALA induced a negative modulation on the cardiomyocyte contraction. β-Alanine, an MrgD agonist, reproduced the time-of-day effects of ALA on myocyte shortening. NG-nitro-l-arginine methyl ester, an NO synthase inhibitor, blocked the increase in fractional shortening induced by ALA at ZT2. No effect of ALA on myocyte shortening was observed at ZT8 and ZT20. Our results show that ALA/MrgD signaling in cardiomyocytes is subject to temporal modulation. This finding has significant implications for pharmacological approaches that combine chronotherapy for cardiac conditions triggered by disruption of circadian rhythms and hormonal signaling.NEW & NOTEWORTHY Alamandine, a member of the renin-angiotensin system, serves critical roles in cardioprotection, including the modulation of cardiomyocyte contractility. Whether this effect varies along the day is unknown. Our results provide evidence that alamandine via receptor MrgD exerts opposing actions on cardiomyocyte shortening, enhancing, or reducing contraction depending on the time of day. These findings may have significant implications for the development and effectiveness of future cardiac therapies.

Overview of pyroptosis mechanism and in-depth analysis of cardiomyocyte pyroptosis mediated by NF-κB pathway in heart failure

The pyroptosis of cardiomyocytes has become an essential topic in heart failure research. The abnormal accumulation of these biological factors, including angiotensin II, advanced glycation end products, and various growth factors (such as connective tissue growth factor, vascular endothelial growth factor, transforming growth factor beta, among others), activates the nuclear factor-κB (NF-κB) signaling pathway in cardiovascular diseases, ultimately leading to pyroptosis of cardiomyocytes. Therefore, exploring the underlying molecular biological mechanisms is essential for developing novel drugs and therapeutic strategies. However, our current understanding of the precise regulatory mechanism of this complex signaling pathway in cardiomyocyte pyroptosis is still limited. Given this, this study reviews the milestone discoveries in the field of pyroptosis research since 1986, analyzes in detail the similarities, differences, and interactions between pyroptosis and other cell death modes (such as apoptosis, necroptosis, autophagy, and ferroptosis), and explores the deep connection between pyroptosis and heart failure. At the same time, it depicts in detail the complete pathway of the activation, transmission, and eventual cardiomyocyte pyroptosis of the NF-κB signaling pathway in the process of heart failure. In addition, the study also systematically summarizes various therapeutic approaches that can inhibit NF-κB to reduce cardiomyocyte pyroptosis, including drugs, natural compounds, small molecule inhibitors, gene editing, and other cutting-edge technologies, aiming to provide solid scientific support and new research perspectives for the prevention and treatment of heart failure.

The vascular influence of melatonin on endothelial response to angiotensin II in diabetic rat aorta

The current study explored melatonin (MEL) and its receptors, including MEL type 1 receptor (MT1) receptor and MEL type 2 receptor (MT2), along with the angiotensin-converting enzyme 2 (ACE2), influence on vascular responses to angiotensin II (Ang II) in rat aortic segments of normal and diabetic rats. The isolated aortic segments were exposed to MEL, the MEL agonist; ramelteon (RAM), the MEL antagonist; luzindole (LUZ), and an ACE2 inhibitor (S, S)-2-(1-Carboxy-2-(3-(3,5-dichlorobenzyl)-3 H-imidazol-4-yl)-ethylamino)-4-methylpentanoic acid,) on Ang II-induced contractions in non-diabetic normal endothelium (non-DM E+), non-diabetic removed endothelium (non-DM E-), and streptozotocin-induced diabetic endothelium-intact (STZ-induced DM E+) rat aortic segments, as well as their combination in STZ-induced DM E + segments, were also included. The current results showed that MEL and RAM shifted Ang II dose-response curve (DRC) to the right side in non-DM E + and non-DM E- aorta but not in STZ-induced DM E + aorta. However, ACE2 inhibition abolished Ang II degradation only in STZ-induced DM E + segments, not in non-DM E + segments. Additionally, the combinations of MEL-LUZ and RAM-ACE2 inhibitor caused a rightward shift in Ang II response in STZ-induced DM E + segments, while the MEL-LUZ combination decreased Ang II DRC. The findings suggest that the effects of MEL and ACE2 inhibitor on Ang II responses depend on the condition of the endothelium and the distribution of the MEL receptors.

Vascular smooth muscle cell phenotypic switching in atherosclerosis

Atherosclerosis (AS) is a complex pathology process involving intricate interactions among various cells and biological processes. Vascular smooth muscle cells (VSMCs) are the predominant cell type in normal arteries, and under atherosclerotic stimuli, VSMCs respond to altered blood flow and microenvironment changes by downregulating contractile markers and switching their phenotype. This review overviews the diverse phenotypes of VSMCs, including the canonical contractile VSMCs, synthetic VSMCs, and phenotypes resembling macrophages, foam cells, myofibroblasts, osteoblasts/chondrocytes, and mesenchymal stem cells. We summarize their presumed protective and pro-atherosclerotic roles in AS development. Additionally, we underscore the molecular mechanisms and regulatory pathways governing VSMC phenotypic switching, encompassing transcriptional regulation, biochemical factors, plaque microenvironment, epigenetics, miRNAs, and the cytoskeleton, emphasizing their significance in AS development. Finally, we outline probable future research directions targeting VSMCs, offering insights into potential therapeutic strategies for AS management.

Atrial Fibrillation and Underlying Structural and Electrophysiological Heterogeneity

As atrial fibrillation (AF) progresses from initial paroxysmal episodes to the persistent phase, maintaining sinus rhythm for an extended period through pharmacotherapy and catheter ablation becomes difficult. A major cause of the deteriorated treatment outcome is the atrial structural and electrophysiological heterogeneity, which AF itself can exacerbate. This heterogeneity exists or manifests in various dimensions, including anatomically segmental structural features, the distribution of histological fibrosis and the autonomic nervous system, sarcolemmal ion channels, and electrophysiological properties. All these types of heterogeneity are closely related to the development of AF. Recognizing the heterogeneity provides a valuable approach to comprehending the underlying mechanisms in the complex excitatory patterns of AF and the determining factors that govern the seemingly chaotic propagation. Furthermore, substrate modification based on heterogeneity is a potential therapeutic strategy. This review aims to consolidate the current knowledge on structural and electrophysiological atrial heterogeneity and its relation to the pathogenesis of AF, drawing insights from clinical studies, animal and cell experiments, molecular basis, and computer-based approaches, to advance our understanding of the pathophysiology and management of AF.

New Perspectives on Obesity-Associated Nephropathy from Pathophysiology to Therapeutics: Revealing the Promise of GLP-1 RA Therapy

Obesity represents a substantial risk factor for a multitude of metabolic disorders, which seriously threatens human life and health. As the global obesity epidemic intensifies, obesity-related nephropathy (ORN) has attracted great attention. ORN arises from both physical/mechanical and non-physical insults to the glomerular and tubular structures precipitated by obesity, culminating in structural impairments and functional aberrations within the kidneys. Physical injury factors include changes in renal hemodynamics, renal compression, and mechanical stretching of podocytes. Non-physical injury factors include overactivation of the RAAS system, insulin resistance, lipotoxicity, inflammation, and dysregulation of bile acid metabolism. Exploring molecules that target modulation of physical or nonphysical injury factors is a potential approach to ORN treatment. ORN is characterized clinically by microproteinuria and pathologically by glomerulomegaly, which is atypical and makes early diagnosis difficult. Investigating early diagnostic markers for ORN thus emerges as a critical direction for future research. Additionally, there is no specific drug for ORN in clinical treatment, which mainly focuses on weight reduction, mitigating proteinuria, and preserving renal function. In our review, we delineate a progressive therapeutic approach involving enhancements in lifestyle, pharmacotherapy, and bariatric surgery. Our emphasis underscores glucagon-like peptide-1 receptor agonists (GLP-1 RAs) as poised to emerge as pivotal therapeutic modalities for ORN in forthcoming clinical avenues.

Organ crosstalk and dysfunction in sepsis

Sepsis is a dysregulated immune response to an infection that leads to organ dysfunction. Sepsis-associated organ dysfunction involves multiple inflammatory mechanisms and complex metabolic reprogramming of cellular function. These mechanisms cooperate through multiple organs and systems according to a complex set of long-distance communications mediated by cellular pathways, solutes, and neurohormonal actions. In sepsis, the concept of organ crosstalk involves the dysregulation of one system, which triggers compensatory mechanisms in other systems that can induce further damage. Despite the abundance of studies published on ​​organ crosstalk in the last decade, there is a need to formulate a more comprehensive framework involving all organs to create a more detailed picture of sepsis. In this paper, we review the literature published on organ crosstalk in the last 10 years and explore how these relationships affect the progression of organ failure in patients with septic shock. We explored these relationships in terms of the heart-kidney-lung, gut-microbiome-liver-brain, and adipose tissue-muscle-bone crosstalk in sepsis patients. A deep connection exists among these organs based on crosstalk. We also review how multiple therapeutic interventions administered in intensive care units, such as mechanical ventilation, antibiotics, anesthesia, nutrition, and proton pump inhibitors, affect these systems and must be carefully considered when managing septic patients. The progression to multiple organ dysfunction syndrome in sepsis patients is still one of the most frequent causes of death in critically ill patients. A better understanding and monitoring of the mechanics of organ crosstalk will enable the anticipation of organ damage and the development of individualized therapeutic strategies.

A molecular mechanism for angiotensin II receptor blocker-mediated slit membrane protection: Angiotensin II increases nephrin endocytosis via AT1-receptor-dependent ERK 1/2 activation

Albuminuria is characterized by a disruption of the glomerular filtration barrier, which is composed of the fenestrated endothelium, the glomerular basement membrane, and the slit diaphragm. Nephrin is a major component of the slit diaphragm. Apart from hemodynamic effects, Ang II enhances albuminuria by β-Arrestin2-mediated nephrin endocytosis. Blocking the AT1 receptor with candesartan and irbesartan reduces the Ang II-mediated nephrin-β-Arrestin2 interaction. The inhibition of MAPK ERK 1/2 blocks Ang II-enhanced nephrin-β-Arrestin2 binding. ERK 1/2 signaling, which follows AT1 receptor activation, is mediated by G-protein signaling, EGFR transactivation, and β-Arrestin2 recruitment. A mutant AT1 receptor defective in EGFR transactivation and β-Arrestin2 recruitment reduces the Ang II-mediated increase in nephrin β-Arrestin2 binding. The mutation of β-Arrestin2K11,K12, critical for AT1 receptor binding, completely abrogates the interaction with nephrin, independent of Ang II stimulation. β-Arrestin2K11R,K12R does not influence nephrin cell surface expression. The data presented here deepen our molecular understanding of a blood-pressure-independent molecular mechanism of AT-1 receptor blockers (ARBs) in reducing albuminuria.

Valsartan as a prophylactic treatment against breast cancer development and niche activation: What molecular sequels follow chronic AT-1R blockade?

AIMS

Transactivation of insulin-growth-factor-receptor (IGF-1R) by angiotensin-II-type-1-receptor (AT-1R) was only demonstrated in vascular-smooth-muscle cells and has never been tested in breast-cancer (BC). This investigation addressed the impact of chronic AT-1R blockade by valsartan (Val) on possible concurrent AT-1R/IGF-1R signaling inhibition, regressing BC-tumor-microenvironment (TME) cellular components activation, and hindering BC development.

MAIN METHODS

The effect of different Val doses (10, 20, 40 & 80 mg/kg/day for 490 days) was tested on dimethylbenz(a)anthracene (DMBA)-induced progesterone-promoted-BC in rats. The influence on intratumoral/circulating angiotensin-II (ANG-II) levels and AT-1R/Mas-R immunofluorescent-expression were assessed. The potential AT-1R/IGF-1R crosstalk within TME-BC-stem-cells (BCSCs) and cancer-associated-fibroblasts (CAFs) was evaluated by fluorescently marking these cells and locating the immunofluorescently-stained AT-1R/IGF-1R in them using confocal-laser-microscopy and further quantified by flow cytometry. In addition, the molecular alterations following blocking AT-1R were inspected including determining Src; crucial for IGF-1R transactivation by AT-1R, Notch-1; IGF-IR transcriptional-regulator, and PI3K/Akt &IL-6/STAT expression. Further, the suppression of CSCs' capabilities to maintain pluripotency, stemness features, epithelial-to-mesenchymal-transition (EMT), and angiogenesis was evaluated by assessing NANOG gene, aldehyde-dehydrogenase (ALDH), N-cadherin and vascular-endothelial-growth-factor (VEGF), respectively. Furthermore, the proliferative marker; Ki-67, was detected by immunostaining, and tumors were histologically graded using Elston-Ellis-modified-Scarff-Bloom-Richardson method.

KEY FINDINGS

Prophylactic Val significantly reduced tumor size, prolonged latency, reduced tumor histopathologic grade, decreased circulating/intratumoral-ANG-II levels, increased Mas-R, and decreased AT1R expression. AT-1R/IGF-1R were co-expressed with a high correlation coefficient on CAFs/BCSCs. Moreover, Val significantly attenuated IGF-1R transactivation and transcriptional regulation via Src and Notch-1 genes' downregulation and reduced Src/IGF-IR-associated PI3K/Akt and IL-6/STAT3 signaling. Further, Val significantly decreased intratumoral NANOG, ALDH, N-cadherin, VEGF, and Ki-67 levels.

SIGNIFICANCE

Chronic Val administration carries a potential for repurposing as adjuvant or conjunct therapy for patients at high risk for BC.

Angiotensin II, blood-brain barrier permeability, and microglia interplay during the transition from pre-to hypertensive phase in spontaneously hypertensive rats

Background

Hypertension is characterized by upregulation of the renin-angiotensin system, increased blood-brain barrier (BBB) permeability, microglia activation within autonomic nuclei, and an intense sympathoexcitation. There is no information on the interplay of these events during the development of neurogenic hypertension. We sought to identify the interaction and time-course changes of Ang II availability, barrier dysfunction, microglia activation, and autonomic imbalance within autonomic areas during the development of neurogenic hypertension.

Methods

Sequential changes of hemodynamic/autonomic parameters, BBB permeability, microglia structure/density (IBA-1), and angiotensin II (Ang II) immunofluorescence were evaluated within the paraventricular hypothalamic nucleus, nucleus of the solitary tract, and rostral ventrolateral medulla of Wistar and spontaneously hypertensive rats (SHRs) aged 4 weeks, 5 weeks, 6 weeks, 8 weeks, and 12 weeks. The somatosensory cortex and hypoglossal nucleus were also analyzed as non-autonomic control areas.

Results

Increased brain Ang II availability (4th-5th week) was the first observed change, followed by the incipient BBB leakage and increased microglia density (6th week). From the 5th-6th weeks on, BBB leakage, Ang II, and IBA-1 densities increased continuously, allowing a parallel increase in both Ang II-microglia colocalization and the transition of microglial cells from highly ramified in the basal surveillant condition (4th-5th week) to shorter process arbors, fewer endpoints, and enlarged soma in the disease-associate condition (6th week to the 12th week). Simultaneously with increased Ang II-microglia colocalization and microglia morphologic phenotypic changes, sympathetic activity and pressure variability increased, autonomic control deteriorated, and blood pressure increased. These responses were not specific for autonomic nuclei but also occurred at a lower magnitude in the somatosensory cortex and hypoglossal nucleus, indicating the predominance of hypertension-induced effects on autonomic areas. No changes were observed in age-matched controls where Ang II density did not change.

Conclusion

Brain Ang II density is the initial stimulus to drive coordinated changes in BBB permeability and microglial reactivity. Increased BBB dysfunction allows access of plasma Ang II and increases its local availability and the colocalization and activation of microglial cells. It is a potent stimulus to augments vasomotor sympathetic activity, autonomic imbalance, and pressure elevation during the establishment of hypertension.

Angiotensin II-Real-Life Use and Literature Review

Angiotensin II is a recently introduced vasopressor, which has been available since 2017. The novelty and the relatively high cost of angiotensin II currently limit its broader application. It induces vasoconstriction by activating the renin-angiotensin-aldosterone system and is currently the sole vasopressor functioning through this pathway. Beyond vasoconstriction, angiotensin II also affects various other physiological processes. Current evidence supports its use in managing vasoplegic and cardiogenic shock in patients who are unresponsive to catecholamines and vasopressin. However, due to limited data, the optimal timing for initiating therapy with angiotensin II, strategies for combining it with other vasopressors, and strategies for its discontinuation remain unclear. Ongoing and planned studies aim to address some of these uncertainties. This article reviews the physiological and pathophysiological effects of angiotensin II, describes its pharmacology, and provides a narrative review of the current literature.

Unraveling the Mechanisms of Magnesium Supplementation in Alleviating Chronic Kidney Disease Complications and Progression: Balancing Risks and Benefits

Chronic kidney disease (CKD) is a major cause of death and disability worldwide. It is usually diagnosed at early levels because of its slow progression. Treatment should consider CKD complications (such as electrolyte level imbalance, vascular calcification, and bone mineral disorders), as well as the development of CKD itself. Large-scale studies have shown that current treatment guidelines are nearly ineffective and fail to achieve treatment goals. Guidelines have not paid as much attention to magnesium (Mg) as the other electrolytes, while Mg has a significant role in the treatment goals of CKD. Hypomagnesemia is the only electrolyte imbalance that is equally prevalent in all stages of CKD. A lower plasma Mg level in each stage of CKD is associated with a higher risk of CKD progression and cardiac events. Magnesium exerts its effects both directly and via other ions. Mg supplementation increases insulin sensitivity while reducing proteinuria and inflammation. It lowers blood pressure and inhibits vascular calcification primarily because of its effects on calcium and phosphate, respectively. Vitamin D supplementation for low-active vitamin D in CKD patients increases vascular calcification and cardiac events, but magnesium supplementation enhances vitamin D levels and activity without increasing the risk of cardiac events. However, careful attention is required due to the potential threats of hypermagnesemia, particularly in advanced CKD stages. Starting magnesium supplementation early in patients' treatment plans will result in fewer side effects and more advantages. More original research is needed to determine its optimal dose and serum levels.

Qingda Granule Attenuates Hypertension-Induced Cardiac Damage via Regulating Renin-Angiotensin System Pathway

OBJECTIVE

To assess the efficacy of Qingda Granule (QDG) in ameliorating hypertension-induced cardiac damage and investigate the underlying mechanisms involved.

METHODS

Twenty spontaneously hypertensive rats (SHRs) were used to develope a hypertension-induced cardiac damage model. Another 10 Wistar Kyoto (WKY) rats were used as normotension group. Rats were administrated intragastrically QDG [0.9 g/(kg•d)] or an equivalent volume of pure water for 8 weeks. Blood pressure, histopathological changes, cardiac function, levels of oxidative stress and inflammatory response markers were measured. Furthermore, to gain insights into the potential mechanisms underlying the protective effects of QDG against hypertension-induced cardiac injury, a network pharmacology study was conducted. Predicted results were validated by Western blot, radioimmunoassay immunohistochemistry and quantitative polymerase chain reaction, respectively.

RESULTS

The administration of QDG resulted in a significant decrease in blood pressure levels in SHRs (P<0.01). Histological examinations, including hematoxylin-eosin staining and Masson trichrome staining revealed that QDG effectively attenuated hypertension-induced cardiac damage. Furthermore, echocardiography demonstrated that QDG improved hypertension-associated cardiac dysfunction. Enzyme-linked immunosorbent assay and colorimetric method indicated that QDG significantly reduced oxidative stress and inflammatory response levels in both myocardial tissue and serum (P<0.01).

CONCLUSIONS

Both network pharmacology and experimental investigations confirmed that QDG exerted its beneficial effects in decreasing hypertension-induced cardiac damage by regulating the angiotensin converting enzyme (ACE)/angiotensin II (Ang II)/Ang II receptor type 1 axis and ACE/Ang II/Ang II receptor type 2 axis.

Dapagliflozin: A sodium-glucose cotransporter 2 inhibitor, attenuates angiotensin II-induced atrial fibrillation by regulating atrial electrical and structural remodeling

AIM

Atrial fibrillation (AF), the most common arrhythmia, is characterized by atrial electrical and structural remodeling. Previous studies have found that sodium-glucose cotransporter 2 inhibitor (SGLT2i) can protect myocardium in a glucose independent mechanism. But the role of SGLT2i in regulating AF remains largely unknown. This study, we aimed to investigate the effect of Dapagliflozin (DAPA) in reducing AF susceptibility via inhibiting electrical and structural remodeling.

METHOD

The mouse model was established by Angiotensin II (2000 ng/kg/min) infusion for 3 weeks, and an in vitro model was generated by stimulating HL-1 and primary mouse fibroblast with Ang II (1 μM) for 24 h. Programmed electrical stimulation, ECG and whole-cell patch clamp were used to detect DAPA effect on atrial electrical remodeling induced by Ang II. To observe DAPA effect on atrial structural remodeling induced by Ang II, we used echocardiographic, H&E and Masson staining to evaluate atrial dilation. To further explore the protective mechanism of DAPA, we adopt in silico molecular docking approaches to investigate the binding affinity of Ang II and CaMKII at Met-281 site. Western blot was to detect expression level of CaMKII, ox-CaMKII, Nav1.5, Kv4.3, Kv4.2, Kchip2, Kir2.1 and Cx40.

RESULTS

Ang II induced AF, atrial dilatation and fibrosis, led to atrial electrical and structural remodeling. However, these effects were markedly abrogated by DAPA treatment, a specific SGLT2i. Our observation of atrial electrical activity in mice revealed that DAPA could rescue the prolonged action potential duration (APD) and the abnormal currents of IK1, Ito and INaL triggered by Ang II infusion. DAPA could reduce the binding affinity of Ang II and CaMKII at Met-281 site, which indicated that DAPA may directly alleviate the activation of CaMKII caused by Ang II. DAPA could reduce the upregulation of ox-CaMKII caused by Ang II infusion in atrial tissues. Moreover, DAPA also ameliorated the aberrant expression levels of electrical activity related proteins (Nav1.5, Kv4.3, Kv4.2, Kchip2, Kir2.1 and Cx40) and fibrosis related signal pathways (TGF-β1, p-smad/smad) caused by Ang II. Furthermore, we confirmed that DAPA, as well as other SGLT2i (EMPA, CANA), could reverse these abnormalities caused by Ang II incubation in HL-1 cells and primary mouse fibroblasts, respectively.

CONCLUSION

Overall, our study identifies DAPA, a widely used SGLT2i, contributes to inhibiting Ang II-induced ox-CaMKII upregulation and electrical and structural remodeling to reduce AF susceptibility, suggesting that DAPA may be a potential therapy of treating AF.

Agonists of galanin subtype 2 receptor may prevent pancreatic cancer and agonists of angiotensin II type 2 receptor may prevent colorectal cancer

Pancreatic ductal adenocarcinoma (PDAC) remains a dreadful disease with poor prognosis. While the prognosis of colorectal carcinoma (CRC) is better than that of PDAC, it still is the second-leading cause of cancer deaths worldwide. Recently, a (methyl)lanthionine-stabilized, highly receptor-specific agonist of galanin subtype 2 (GAL2) receptor inhibited the growth of GAL2 receptor-expressing patient-derived xenografts (PDX) of pancreatic cancer. Furthermore, a lanthionine-constrained agonist of angiotensin II type 2 (AT2) receptor inhibited PDX of colorectal cancer in mice. Stimulation of GAL2 receptor may modulate immune surveillance and inhibits PDAC via cell cycle inhibition and apoptosis. Consistent with GAL2 receptor-mediated tumor inhibition, for PDAC, survival is much higher for patients with high GAL2 receptor expression. Importantly, a (methyl)lanthionine-stabilized GAL2 receptor-specific agonist enhances expression of GAL2 receptor, not only in PDAC-PDX but also in healthy tissue indicating therapeutic and preventive potentials for GAL2 receptor agonists. AT2 receptor is interacting with four tumor suppressor proteins, Src homology phosphatase 1, Src homology phosphatase 2, Promyelocytic Leukemia Zinc Finger protein and Microtuble-Associated Scaffold Protein1, the latter also known as Angiotensin-II type 2 receptor-Interacting Protein. Pathways linked to these tumor suppressor proteins may enhance immune surveillance, prevent carcinogenesis, counter proliferation and stimulate apoptosis. Taken together, current data are prompting the hypothesis of a prophylactic treatment option with stable, specific and safe agonists of GAL2 receptor and AT2 receptor to prevent the emergence of pancreatic and colorectal cancer in individuals at risk.

Identifying microRNAs Possibly Implicated in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Fibromyalgia: A Review

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and fibromyalgia (FM) are chronic syndromes of unknown etiology, accompanied by numerous symptoms affecting neurological and physical conditions. Despite frequent revisions of the diagnostic criteria, clinical practice guidelines are often outdated, leading to underdiagnosis and ineffective treatment. Our aim was to identify microRNA (miRNA) biomarkers implicated in pathological mechanisms underlying these diseases. A comprehensive literature review using publicly accessible databases was conducted. Interesting miRNAs were extracted from relevant publications on ME/CFS and/or FM, and were then linked to pathophysiological processes possibly manifesting these chronic diseases. Dysregulated miRNAs in ME/CFS and FM may serve as promising biomarkers for these diseases. Key identified miRNAs, such as miR-29c, miR-99b, miR-128, miR-374b, and miR-766, were frequently mentioned for their roles in immune response, mitochondrial dysfunction, oxidative stress, and central sensitization, while miR-23a, miR-103, miR-152, and miR-320 were implicated in multiple crucial pathological processes for FM and/or ME/CFS. In summary, both ME/CFS and FM seem to share many dysregulated biological or molecular processes, which may contribute to their commonly shared symptoms. This miRNA-based approach offers new angles for discovering molecular markers urgently needed for early diagnosis or therapeutics to tackle the pathology of these medically unexplained chronic diseases.

Antihypertensive drug-associated adverse events in osteoarthritis: a study of a large real-world sample based on the FAERS database

Background

Hypertension is a common complication in patients with osteoarthritis (OA). There is increasing interest in the relationship between hypertension and OA. However, hypertension has been reported to negatively affect symptoms and quality of life in patients with OA. Therefore, treating hypertension is crucial for patients with OA. However, there is a lack of real-world studies on the effects of medications for treating hypertension on OA.

Methods

Data from the FAERS database from January 2004 to December 2023 were extracted for disproportionality analyses, and proportional reporting ratios (PRRs) were used to assess the association between medications for hypertension and all types of arthritis. Adverse event signals were identified and determined using reporting odds ratios (RORs) Adverse event signals were considered to have occurred if a drug-induced adverse event was recorded more than or equal to 3 and the lower limit of the ROR confidence interval was more than 1. We selected five classes of drugs including, calcium channel blockers (CCBs), angiotensin converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), thiazide diuretics and β-blockers and representative drugs were analysed for osteoarthritis-related adverse reactions, and age and gender subgroups were analysed for drugs of significance. We also analysed the occurrence of AEs in relation to time using the Weibull distribution.

Results

In terms of overall data, we found significant OA adverse reaction signals only for ARBs among the five drug classes.ARB AEs for spinal osteoarthritis (ROR 4.64, 95% CI 3.62-5.94), osteoarthritis (ROR 3.24 95% CI 2.82-3.72) and gouty arthritis (ROR 3.27 95% CI 1.22-8.75) were the three adverse reactions with the loudest signals. Next, we found that valsartan had strong osteoarthritis adverse reaction signals among the three ARBs, namely, irbesartan, cloxartan, and valsartan. We also analysed age and gender subgroups and found that osteoarthritis signals were strongest in the 18-65 and 65+ population, while females seem to be more prone to valsartan-related OA AEs.

Conclusion

ARBs, especially valsartan, have significant positive signals for OA AEs. Therefore, ARB drugs, especially valsartan, should be used with caution when treating patients with OA combined with hypertension.

Sox17 protects human brain microvascular endothelial cells from AngII-induced injury by regulating autophagy and apoptosis

Intracranial aneurysm (IA), is a localized dilation of the intracranial arteries, the rupture of which is catastrophic. Hypertension is major IA risk factor that mediates endothelial cell damage. Sox17 is highly expressed in intracranial vascular endothelial cells, and GWAS studies indicate that its genetic alteration is one of the major genetic risk factors for IA. Vascular endothelial cell injury plays a vital role in the pathogenesis of IA. The genetic ablation of Sox17 plus hypertension induced by AngII can lead to an increased incidence of intracranial aneurysms had tested in the previous animal experiments. In order to study the underlying molecular mechanisms, we established stable Sox17-overexpressing and knockdown cell lines in human brain microvascular endothelial cells (HBMECs) first. Then flow cytometry, western blotting, and immunofluorescence were employed. We found that the knockdown of Sox17 could worsen the apoptosis and autophagy of HBMECs caused by AngII, while overexpression of Sox17 had the opposite effect. Transmission electron microscopy displayed increased autophagosomes after the knockdown of Sox17 in HBMECs. The RNA-sequencing analysis shown that dysregulation of the Sox17 gene was closely associated with the autophagy-related pathways. Our study suggests that Sox17 could protect HBMECs from AngII-induced injury by regulating autophagy and apoptosis.

Interaction of Angiotensin-(1-7) with kinins in the kidney circulation: Role of B1 receptors

Changes in renal hemodynamics impact renal function during physiological and pathological conditions. In this context, renal vascular resistance (RVR) is regulated by components of the Renin-Angiotensin System (RAS) and the Kallikrein-Kinin System (KKS). However, the interaction between these vasoactive peptides on RVR is still poorly understood. Here, we studied the crosstalk between angiotensin-(1-7) and kinins on RVR. The right kidneys of Wistar rats were isolated and perfused in a closed-circuit system. The perfusion pressure and renal perfusate flow were continuously monitored. Ang-(1-7) (1.0-25.0 nM) caused a sustained, dose-dependent reduction of relative RVR (rRVR). This phenomenon was sensitive to 10 nM A-779, a specific Mas receptor (MasR) antagonist. Bradykinin (BK) promoted a sustained and transient reduction in rRVR at 1.25 nM and 125 nM, respectively. The transient effect was abolished by 4 μM des-Arg9-Leu8-bradykinin (DALBK), a specific kinin B1 receptor (B1R) antagonist. Accordingly, des-Arg9-bradykinin (DABK) 1 μM (a B1R agonist) increased rRVR. Interestingly, pre-perfusion of Ang-(1-7) changed the sustained reduction of rRVR triggered by 1.25 nM BK into a transient effect. On the other hand, pre-perfusion of Ang-(1-7) primed and potentiated the DABK response, this mechanism being sensitive to A-779 and DALBK. Binding studies performed with CHO cells stably transfected with MasR, B1R, and kinin B2 receptor (B2R) showed no direct interaction between Ang-(1-7) with B1R or B2R. In conclusion, our findings suggest that Ang-(1-7) differentially modulates kinin's effect on RVR in isolated rat kidneys. These results help to expand the current knowledge regarding the crosstalk between the RAS and KKS complex network in RVR.

Fundamentals of protein chemistry at the Institute of Biomedical Chemistry

Eighty years ago, the Institute of Biomedical Chemistry (IBMC) initially known as the Institute of Biological and Medical Chemistry of the Academy of Sciences of the USSR was founded. During the first decades significant studies were performed; they not only contributed to a deeper understanding of biochemical processes in the living organisms, but also laid the foundation for further development of these fields. The main directions of IBMC were focused on studies of structures of enzymes (primarily various proteases), their substrates and inhibitors, the role of enzymes of carbohydrate metabolism in the development of pathologies, study of the mechanisms of hydrolytic and oxidative-hydrolytic transformation of organic compounds, studies of connective tissue proteins, including collagens, study of amino acid metabolism. It is difficult to find papers from that period in current online literature databases, so this review will help to understand the value of studies performed at IBMC during the first 40 years after its organization, as well as their impact on modern research.

Advancing the understanding of diabetic encephalopathy through unravelling pathogenesis and exploring future treatment perspectives

Diabetic encephalopathy (DE), a significant micro-complication of diabetes, manifests as neurochemical, structural, behavioral, and cognitive alterations. This condition is especially dangerous for the elderly because aging raises the risk of neurodegenerative disorders and cognitive impairment, both of which can be made worse by diabetes. Despite its severity, diagnosis of this disease is challenging, and there is a paucity of information on its pathogenesis. The pivotal roles of various cellular pathways, activated or influenced by hyperglycemia, insulin sensitivity, amyloid accumulation, tau hyperphosphorylation, brain vasculopathy, neuroinflammation, and oxidative stress, are widely recognized for contributing to the potential causes of diabetic encephalopathy. We also reviewed current pharmacological strategies for DE encompassing a comprehensive approach targeting metabolic dysregulations and neurological manifestations. Antioxidant-based therapies hold promise in mitigating oxidative stress-induced neuronal damage, while anti-diabetic drugs offer neuroprotective effects through diverse mechanisms, including modulation of insulin signaling pathways and neuroinflammation. Additionally, tissue engineering and nanomedicine-based approaches present innovative strategies for targeted drug delivery and regenerative therapies for DE. Despite significant progress, challenges remain in translating these therapeutic interventions into clinical practice, including long-term safety, scalability, and regulatory approval. Further research is warranted to optimize these approaches and address remaining gaps in the management of DE and associated neurodegenerative disorders.

Antihypertensive medications and dementia in older adults with hypertension

Background

Studies on middle-aged or individuals with cognitive or cardiovascular impairments, have established that intensive blood pressure (BP) control reduces cognitive decline risk. However, uncertainty exists on differential effects between antihypertensive medications (AHM) classes on this risk, independent of BP-lowering efficacy, particularly in community-dwelling hypertensive older adults.

Methods

A post-hoc analysis of the ASPREE study, a randomized trial of low-dose aspirin in adults aged 70+ years (65+ if US minorities) without baseline dementia, and followed for two years post-trial. Cox proportional-hazards regression models were used to estimate associations between baseline and time-varying AHM exposure and incident dementia (an adjudicated primary trial endpoint), in participants with baseline hypertension. Subgroup analyses included prespecified factors, APO ε4 carrier status and monotherapy AHM use.

Results

Most hypertensive participants (9,843/13,916; 70.7%) used AHMs. Overall, 'any' AHM use was not associated with lower incident dementia risk, compared with untreated participants (HR 0.84, 95%CI 0.70-1.02, p=0.08), but risk was decreased when angiotensin receptor blockers (ARBs) were included (HR 0.73, 95%CI 0.59-0.92, p=0.007). ARBs and β-blockers decreased dementia risk, whereas angiotensin-converting enzyme inhibitors (ACEIs) and diuretics increased risk. There was no association with RAS modulating or blood-brain-barrier crossing AHMs on dementia risk.

Conclusions

Overall, AHM exposure in hypertensive older adults was not associated with decreased dementia risk, however, specific AHM classes were with risk direction determined by class; ARBs and β-blockers were superior to ACEIs and other classes in decreasing risk. Our findings emphasize the importance of considering effects beyond BP-lowering efficacy when choosing AHM in older adults.

Effects of the ACE2-Ang-(1-7)-Mas axis on gut flora diversity and intestinal metabolites in SuHx mice

Objective

Pulmonary artery hypertension (PAH) poses a significant challenge due to its limited therapeutic options and high mortality rates. The ACE2-Ang-(1-7)-Mas axis plays a pivotal role in regulating blood pressure and inhibiting myocardial remodeling. However, the precise mechanistic links between the ACE2-Ang-(1-7)-Mas axis and PAH remain poorly understood. This study aimed to elucidate the involvement of the ACE2-Ang-(1-7)-Mas axis in the development of PAH.

Methods

PAH was induced in mice using Sugen5416/hypoxia, PAAT/PET ratio and PA were detected using cardiac ultrasound; inflammation related factors such as MCP-1, TNF, IL-10and IL-12p70 were detected in intestines using cytometric bead array (CBA) kits; histopathological and morphological changes in lung and intestinal tissues were assessed via HE staining and Masson staining to evaluate the progression of PAH. Immunohistochemistry and western blotting were employed to determine the expression levels of two tight junction proteins, occludin and ZO-1, in intestinal tissues. Additionally, 16rRNA sequencing and non-targeted metabolomics by LC-MS/MS techniques were utilized to investigate the impact of the ACE2-Ang-(1-7)-Mas axis on microbial diversity and metabolomics of intestinal contents.

Results

Activation of the ACE2-Ang-(1-7)-Mas axis improves heart function, reduces intestines inflammatory factors and ameliorates pathological and histological alterations in SuHx mice. This activation notably upregulated the expression of occludin and ZO-1 proteins in intestinal tissues and promoted the proliferation of SCFA-producing bacteria genera, such as g_Candidatus_Saccharimonas. Furthermore, it enhanced the abundance of beneficial metabolites, including tryptophan and butyric acid.

Conclusion

The findings suggest that modulation of the ACE2-Ang-(1-7)-Mas axis can alleviate PAH by regulating intestinal microbes and metabolites. These results highlight the potential of the ACE2-Ang-(1-7)-Mas axis as a promising therapeutic target for clinical management of PAH.

Targeting the epidermal growth factor receptor (EGFR/ErbB) for the potential treatment of renal pathologies

Epidermal growth factor receptor (EGFR), which is referred to as ErbB1/HER1, is the prototype of the EGFR family of receptor tyrosine kinases which also comprises ErbB2 (Neu, HER2), ErbB3 (HER3), and ErbB4 (HER4). EGFR, along with other ErbBs, is expressed in the kidney tubules and is physiologically involved in nephrogenesis and tissue repair, mainly following acute kidney injury. However, its sustained activation is linked to several kidney pathologies, including diabetic nephropathy, hypertensive nephropathy, glomerulonephritis, chronic kidney disease, and renal fibrosis. This review aims to provide a summary of the recent findings regarding the consequences of EGFR activation in several key renal pathologies. We also discuss the potential interplay between EGFR and the reno-protective angiotensin-(1-7) (Ang-(1-7), a heptapeptide member of the renin-angiotensin-aldosterone system that counter-regulates the actions of angiotensin II. Ang-(1-7)-mediated inhibition of EGFR transactivation might represent a potential mechanism of action for its renoprotection. Our review suggests that there is a significant body of evidence supporting the potential inhibition of EGFR/ErbB, and/or administration of Ang-(1-7), as potential novel therapeutic strategies in the treatment of renal pathologies. Thus, EGFR inhibitors such as Gefitinib and Erlinotib that have an acceptable safety profile and have been clinically used in cancer chemotherapy since their FDA approval in the early 2000s, might be considered for repurposing in the treatment of renal pathologies.

Aldosterone's impact on kidney health: exploring the benefits of mineralocorticoid receptor antagonists for renal protection

Aldosterone, a hormone synthesized by the adrenal cortex, plays a crucial role in regulating sodium and potassium levels in the kidneys through interaction with the mineralocorticoid receptor (MR) in the distal tubules and collecting ducts. While aldosterone aids in maintaining fluid balance by promoting sodium reabsorption and potassium secretion, elevated levels can lead to inflammation, oxidative stress, and organ damage. Experimental evidence highlights aldosterone's involvement in renal inflammation, collagen deposition, and fibrosis, often exacerbating the effects of therapies like angiotensin-converting enzyme inhibitors (ACEIs) by increasing proteinuria and vascular damage. Conversely, mineralocorticoid receptor antagonists (MRAs) show promise in mitigating these harmful effects. This review integrates current knowledge on aldosterone and MRAs, emphasizing their roles in renal health from both clinical and experimental perspectives. Additionally, the novel drug finerenone has shown favorable renal and cardiovascular outcomes in patients with diabetes and chronic kidney disease (CKD), warranting exploration of its potential use in other disease populations in future research.

Endothelial deubiquinatase YOD1 mediates Ang II-induced vascular endothelial-mesenchymal transition and remodeling by regulating β-catenin

Hypertension is a prominent contributor to vascular injury. Deubiquinatase has been implicated in the regulation of hypertension-induced vascular injury. In the present study we investigated the specific role of deubiquinatase YOD1 in hypertension-induced vascular injury. Vascular endothelial endothelial-mesenchymal transition (EndMT) was induced in male WT and YOD1-/- mice by administration of Ang II (1 μg/kg per minute) via osmotic pump for four weeks. We showed a significantly increased expression of YOD1 in mouse vascular endothelial cells upon Ang II stimulation. Knockout of YOD1 resulted in a notable reduction in EndMT in vascular endothelial cells of Ang II-treated mouse; a similar result was observed in Ang II-treated human umbilical vein endothelial cells (HUVECs). We then conducted LC-MS/MS and co-immunoprecipitation (Co-IP) analyses to verify the binding between YOD1 and EndMT-related proteins, and found that YOD1 directly bound to β-catenin in HUVECs via its ovarian tumor-associated protease (OTU) domain, and histidine at 262 performing deubiquitination to maintain β-catenin protein stability by removing the K48 ubiquitin chain from β-catenin and preventing its proteasome degradation, thereby promoting EndMT of vascular endothelial cells. Oral administration of β-catenin inhibitor MSAB (20 mg/kg, every other day for four weeks) eliminated the protective effect of YOD1 deletion on vascular endothelial injury. In conclusion, we demonstrate a new YOD1-β-catenin axis in regulating Ang II-induced vascular endothelial injury and reveal YOD1 as a deubiquitinating enzyme for β-catenin, suggesting that targeting YOD1 holds promise as a potential therapeutic strategy for treating β-catenin-mediated vascular diseases.

AT1b receptors contribute to regional disparities in angiotensin II mediated aortic remodelling in mice

The renin-angiotensin system plays a key role in regulating blood pressure, which has motivated many investigations of associated mouse models of hypertensive arterial remodelling. Such studies typically focus on histological and cell biological changes, not wall mechanics. This study explores tissue-level ramifications of chronic angiotensin II infusion in wild-type (WT) and type 1b angiotensin II (AngII) receptor null (Agtr1b -/-) mice. Biaxial biomechanical and immunohistological changes were quantified and compared in the thoracic and abdominal aorta in these mice following 14 and 28 days of angiotensin II infusion. Preliminary results showed that changes were largely independent of sex. Associated thickening and stiffening of the aortic wall in male mice differed significantly between thoracic and abdominal regions and between genotypes. Notwithstanding multiple biomechanical changes in both WT and Agtr1b -/- mice, AngII infusion caused distinctive wall thickening and inflammation in the descending thoracic aorta of WT, but not Agtr1b -/-, mice. Our study underscores the importance of exploring differential roles of receptor-dependent angiotensin II signalling along the aorta and its influence on distinct cell types involved in regional histomechanical remodelling. Disrupting the AT1b receptor primarily affected inflammatory cell responses and smooth muscle contractility, suggesting potential therapeutic targets.