Renin-angiotensin-aldosterone (RAAS): The ubiquitous system for homeostasis and pathologies

Acute-on-Chronic Inflammation and Patients' Risk for Renal Support in Critically Ill Patients

Hypertension (HTN) and heart failure (HF) can chronically activate the renin-angiotensin-aldosterone system, a mechanism designed to maintain hemodynamic stability by reabsorption of water and electrolytes. Additionally, this system activates the sympathetic nervous system to increase vagal tone. When these patients face acute illness requiring hospitalization, the acute stressor or pathogen also activates the sympathetic nervous system. The combination of activation of both systems puts patients at increased risk of organ failure, specifically renal failure. With early recognition of renal insult, organ damage can be reversed. C-reactive protein (CRP) and D-dimer are commonly used to measure acute inflammation. These biomarkers can alert critical care nurses to excessive inflammation in patients with underlying HTN and HF, enabling nurses to make informed decisions to intervene at the earliest sign of renal failure. This retrospective study of adult SARS-CoV-2 patients in an intensive care unit setting sought to examine the relationship of CRP, D-dimer, and the need for eventual renal support in patients with HF and HTN. Of the sample (n + 189), mean age was 62 (SD = 14.0), and most (70.9%) were male. Thirty-nine patients (20.6%) required renal support. Of the cases requiring renal support, 21 (53.8%) had a history of prior renal disease (P < 0.001, r = 0.351). History of HTN was significantly correlated with requirement for renal support (P = 0.010, r = 0.187). D-dimer (P = 0.038, η = 1.0) and CRP (P = 0.018, η = 0.924) were also significant. Survival was significantly worse in the renal support group (P < 0.001, r = -0.310). D-dimer and CRP were correlated with more severe illness and need for renal support. Study findings have implications for future validation research of chronic inflammation and risk for renal support during acute severe illness.

The dual role of toll-like receptors in COVID-19: Balancing protective immunity and immunopathogenesis

Toll-like receptors (TLRs) of human are considered as the most critical immunological mediators of inflammatory pathogenesis of COVID-19. These immunoregulatory glycoproteins are located on the surface and/or intracellular compartment act as innate immune sensors. Upon binding with distinct SARS-CoV-2 ligand(s), TLRs signal activation of different transcription factors that induce expression of the proinflammatory mediators that collectively induce 'cytokine storm'. Similarly, TLR activation is also pivotal in conferring protection to infection and invasion as well as upregulating the tissue repair pathways. This dual role of the human TLRs in deciding the fate of SARS-CoV-2 has made these receptor proteins as the critical mediators of immunoprotective and immunopathogenic consequences associated with COVID-19. Herein, pathbreaking discoveries exploring the immunobiological importance of the TLRs in COVID-19 and developing TLR-directed therapeutic intervention have been reviewed by accessing the up-to-date literatures available in the public domain/databases. In accordance with our knowledge in association with the importance of TLRs' role against viruses and identification of viral particles, they have been recognized as suitable candidates with high potential as vaccine adjuvants. In this regard, the agonists of TLR4 and TLR9 have effective potential in vaccine technology while the others need further investigations. This comprehensive review suggests that basal level expression of TLRs can act as friends to keep our body safe from strangers but act as a foe via overexpression. Therefore, selective inhibition of the overexpressed TLRs appears to be a solution to counteract the cytokine storm while TLR-agonists as vaccine adjuvants could lessen the risk of infection in the naïve population.

Targeted and untargeted cross-sectional study for sex-specific identification of plasma biomarkers of COVID-19 severity

Coronavirus disease 2019 is a highly contagious respiratory illness caused by the coronavirus SARS-CoV-2. Symptoms can range from mild to severe and typically appear 2-14 days after virus exposure. While vaccination has significantly reduced the incidence of severe complications, strategies for the identification of new biomarkers to assess disease severity remains a critical area of research. Severity biomarkers are essential for personalizing treatment strategies and improving patient outcomes. This study aimed to identify sex-specific biomarkers for COVID-19 severity in a Chilean population (n = 123 female, n = 115 male), categorized as control, mild, moderate, or severe. Data were collected using clinical biochemistry parameters and mass spectrometry-based metabolomics and lipidomics to detect alterations in plasma cytokines, metabolites, and lipid profiles related to disease severity. Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were performed to select significant characteristic features for each group. The results revealed distinct biomarkers for males and females. In males, COVID-19 severity of was associated with inflammation parameters, triglycerides content, and phospholipids profiles. For females, liver damage parameters, triglycerides content, cholesterol derivatives, and phosphatidylcholine were identified as severity biomarkers. For both sexes, most of the biomarker combinations evaluated got areas under the ROC curve greater than 0.8 and low prediction errors. These findings suggest that sex-specific biomarkers can help differentiate the levels of COVID-19 severity, potentially aiding in the development of tailored treatment approaches.

Qifu yixin prescription ameliorates cardiac fibrosis by activating soluble guanylate cyclase (sGC) in heart failure

ETHNOPHARMACOLOGICAL RELEVANCE

Qifu yixin prescription (QYP), an effective traditional Chinese medicine formula, has been utilized in the clinical treatment of cardiovascular diseases for over two decades and has been granted a national invention patent in China. It has demonstrated the ability to improve clinical symptoms in patients with heart failure. However, its precise effects and underlying molecular mechanisms remain unclear.

AIM OF THE STUDY

To evaluate the efficacy of QYP in treating HF and the underlying mechanisms.

MATERIALS AND METHODS

The heart failure (HF) model in mice was established using transverse aortic constriction (TAC), while neonatal rat cardiac fibroblasts (CFs) were utilized for in vitro experiments. The bioactive compounds in QYP were identified through high-performance liquid chromatography (HPLC). Cardiac hypertrophy, function, and fibrosis were assessed using morphological observations, echocardiography, and histomorphometric analyses. To investigate the underlying mechanisms by which QYP alleviates HF, transcriptomic analysis was conducted, and network pharmacology was employed to explore its potential mechanisms of action. Mechanistically, the expression levels of sGC, PKG, ERK, and p-ERK were analyzed using western blotting, immunohistochemistry, and immunofluorescence. Molecular docking was conducted to assess the binding affinity of the compounds of QYP to sGC. Additionally, the effects of QYP on CFs were investigated through cell-based assays.

RESULTS

We identified 33 bioactive compounds in QYP. Histomorphometric and transcriptomic analyses indicated that QYP alleviates cardiac fibrosis in HF. Network pharmacological analysis suggested that the sGC/cGMP/PKG and MAPK pathways are key mechanisms underlying the effects of QYP on cardiac fibrosis. The findings confirmed that QYP activates sGC, leading to the inhibition of ERK phosphorylation. Molecular docking revealed that the compounds of QYP exhibit strong binding affinity to sGC. Additionally, cell-based experiments demonstrated that QYP effectively suppresses CFs activation by stimulating sGC.

CONCLUSIONS

These results indicate QYP improves cardiac fibrosis in HF by activating sGC to inhibit ERK phosphorylation. We propose that QYP is a potential treatment for HF with anti-fibrotic properties.

Nocturia and obstructive sleep apnoea

Nocturia, the need to urinate at night, is a common symptom in patients with obstructive sleep apnoea (OSA). Continuous positive airway pressure treatment can reduce nocturia in some patients, but the underlying mechanisms are complex and not fully understood. OSA affects the autonomic nervous system, oxidative stress and endothelial damage. Furthermore, the commonly held theory attributing polyuria to a false signal of cardiac overload and response natriuresis has limitations. A comprehensive approach to the management of nocturia in OSA, considering factors such as comorbidities, medication use, alcohol consumption and lifestyle, is needed. Effective management of nocturia in OSA requires a multidisciplinary approach, and urologists should be aware of the potential effect of OSA on physiology and refer patients for further testing at a sleep centre. In addition to continuous positive airway pressure, other interventions such as oral appliances and surgical obstruction treatment could be beneficial for some patients. Overall, understanding the complex interplay between OSA and nocturia is crucial for optimizing patient outcomes.

The pharmaco-epigenetics of hypertension: a focus on microRNA

Hypertension is a major harbinger of cardiovascular morbidity and mortality. It predisposes to higher rates of myocardial infarction, chronic kidney failure, stroke, and heart failure than most other risk factors. By 2025, the prevalence of hypertension is projected to reach 1.5 billion people. The pathophysiology of this disease is multifaceted, as it involves nitric oxide and endothelin dysregulation, reactive oxygen species, vascular smooth muscle proliferation, and vessel wall calcification, among others. With the advent of new biomolecular techniques, various studies have elucidated a gaping hole in the etiology and mechanisms of hypertension. Indeed, epigenetics, DNA methylation, histone modification, and microRNA-mediated translational silencing appear to play crucial roles in altering the molecular phenotype into a hypertensive profile. Here, we critically review the experimentally determined associations between microRNA (miRNA) molecules and hypertension pharmacotherapy. Particular attention is given to the epigenetic mechanisms underlying the physiological responses to antihypertensive drugs like candesartan, and other relevant drugs like clopidogrel, aspirin, and statins among others. Furthermore, how miRNA affects the pharmaco-epigenetics of hypertension is especially highlighted.

Association Between Stress, Neuroinflammation, and Irritable Bowel Syndrome: The Positive Effects of Probiotic Therapy

Stress refers to an organism's response to environmental threats in normal condition to maintain homeostasis in the body. In addition, strong inflammatory reactions induced by the hypothalamic-pituitary-adrenal (HPA) axis under stress condition during a long time. Reciprocally, chronic stress can induce the irritable bowel syndrome (IBS) which is a well-known gut disorder thereby play an important role in the promotion and pathophysiology of neuropsychiatric diseases. It has been demonstrated that leaky gut is a hallmark of IBS, leads to the entrance the microbiota into the bloodstream and consequent low-grade systemic inflammation. In the current review, we will discuss the mechanisms by which stress can influence the risk and severity of IBS and its relationship with neuroinflammation. Also, the role of probiotics in IBS co-existing with chronic stress conditions is highlighted.

Paediatric perspectives in the diagnosis of polyuria-polydipsia syndrome

The elucidation of the underlying cause of polyuria-polydipsia syndrome (PPS) is a challenging-especially in the differentiation of partial defects of arginine vasopressin (AVP) secretion or action from primary polydipsia. The water deprivation test has been utilized for many decades, and its application in the paediatric population has been applied using parameters predominantly established in adult cohorts. In more recent times, the development of automated commercial assays for copeptin, a surrogate marker for AVP, has represented a significant advancement in the diagnostic approach to PPS. Measurement of copeptin concentrations has major advantages and has essentially superseded measurement of AVP in diagnostic protocols for PPS. Additionally, stimulated-copeptin protocols utilizing hypertonic saline infusion, arginine, and glucagon have been investigated, and are promising. However, further studies are required in the population-incorporating the differences in physiological regulation of water homeostasis, and safety requirements-before there is widespread adoption into clinical practice.

The renin-angiotensin-aldosterone system: An old tree sprouts new shoots

The intricate physiological and pathological diversity of the Renin-Angiotensin-Aldosterone System (RAAS) underpins its role in maintaining bodily equilibrium. This paper delves into the classical axis (Renin-ACE-Ang II-AT1R axis), the protective arm (ACE2-Ang (1-7)-MasR axis), the prorenin-PRR-MAP kinases ERK1/2 axis, and the Ang IV-AT4R-IRAP cascade of RAAS, examining their functions in both physiological and pathological states. The dysregulation or hyperactivation of RAAS is intricately linked to numerous diseases, including cardiovascular disease (CVD), renal damage, metabolic disease, eye disease, Gastrointestinal disease, nervous system and reproductive system diseases. This paper explores the pathological mechanisms of RAAS in detail, highlighting its significant role in disease progression. Currently, in addition to traditional drugs like ACEI, ARB, and MRA, several novel therapeutics have emerged, such as angiotensin receptor-enkephalinase inhibitors, nonsteroidal mineralocorticoid receptor antagonists, aldosterone synthase inhibitors, aminopeptidase A inhibitors, and angiotensinogen inhibitors. These have shown potential efficacy and application prospects in various clinical trials for related diseases. Through an in-depth analysis of RAAS, this paper aims to provide crucial insights into its complex physiological and pathological mechanisms and offer valuable guidance for developing new therapeutic approaches. This comprehensive discussion is expected to advance the RAAS research field and provide innovative ideas and directions for future clinical treatment strategies.

Functions of TAM Receptors and Ligands Protein S and Gas6 in Atherosclerosis and Cardiovascular Disease

Atherosclerosis and cardiovascular disease are associated with high morbidity and mortality in industrialized nations. The Tyro3, Axl, and Mer (TAM) family of receptor tyrosine kinases is involved in the amplification or resolution of atherosclerosis pathology and other cardiovascular pathology. The ligands of these receptors, Protein S (PS) and growth arrest specific protein 6 (Gas6), are essential for TAM receptor functions in the amplification and resolution of atherosclerosis. The Axl-Gas6 interaction has various effects on cardiovascular disease. Mer and PS dampen inflammation, thereby protecting against atherosclerosis progression. Tyro3, the least studied TAM receptor in cardiovascular disease, appears to protect against fibrosis in post-myocardial infarction injury. Ultimately, PS, Gas6, and TAM receptors present an exciting avenue of potential therapeutic targets against inflammation associated with atherosclerosis and cardiovascular disease.

Peripheral Blood Leukocyte Subpopulation Changes in Reaction to an Acute Psychosocial Stressor as Compared to an Active Placebo-Stressor in Healthy Young Males: Mediating Effects of Major Stress-Reactive Endocrine Parameters

Psychosocial stress has been proposed to induce a redistribution of immune cells, but a comparison with an active placebo-psychosocial stress control condition is lacking so far. We investigated immune cell redistribution due to psychosocial stress compared to that resulting from an active placebo-psychosocial stress but otherwise identical control condition. Moreover, we tested for mediating effects of endocrine parameters and blood volume changes. The final study sample comprised 64 healthy young men who underwent either a psychosocial stress condition (Trier Social Stress Test; TSST; n = 38) or an active placebo-psychosocial stress control condition (PlacTSST; n = 26). Immune cell counts and hemoglobin, epinephrine, norepinephrine, ACTH, renin, and aldosterone levels, as well as those of saliva cortisol, were determined before and up to 30 min after the TSST/PlacTSST. The TSST induced greater increases in total leukocyte, monocyte, and lymphocyte levels as compared to the PlacTSST (p's ≤ 0.001), but in not granulocyte counts. Neutrophil granulocyte counts increased in reaction to both the TSST and PlacTSST (p's ≤ 0.001), while eosinophil and basophil granulocyte counts did not. The psychosocial stress-induced increases in immune cell counts from baseline to peak (i.e., +1 min after TSST cessation) were independently mediated by parallel increases in epinephrine (ab's ≤ -0.43; 95% CIs [LLs ≤ -0.66; ULs ≤ -0.09]). Subsequent decreases in immune cell counts from +1 min to +10 min after psychosocial stress cessation were mediated by parallel epinephrine, renin, and blood volume decreases (ab's ≥ 0.17; 95% CIs [LLs ≥ 0.02; ULs ≥ 0.35]). Our findings indicate that psychosocial stress specifically induces immune cell count increases in most leukocyte subpopulations that are not secondary to the physical or cognitive demands of the stress task. Increases in the number of circulating neutrophil granulocytes, however, are not psychosocial stress-specific and even occur in situations with a low probability of threat or harm. Our findings point to a major role of epinephrine in mediating stress-induced immune cell count increases and of epinephrine, renin, and blood volume changes in mediating subsequent immune cell count decreases from +1 min to +10 min after psychosocial stress cessation.

Cross talk on therapeutic strategies: natriuretic peptides and inhibiting neprilysin in hypertension management

Hypertension, a prevalent cardiovascular condition globally, remains a significant public health concern due to its association with increased cardiovascular morbidity and mortality. Despite the availability of various antihypertensive therapies, achieving optimal blood pressure control in patients remains a challenge. Valsartan/sacubitril (ARNi), marketed as Entresto by Novartis, combines valsartan, an angiotensin receptor blocker, with sacubitril, an inhibitor of neprilysin. Neprilysin is responsible for breaking down natriuretic peptides and other vasoactive substances. Inhibiting neprilysin prevents the degradation of natriuretic peptides, enhancing their beneficial effects on blood pressure regulation. Natriuretic Peptides, including atrial natriuretic peptide (ANP) and brain natriuretic peptides (BNP), play pivotal roles in regulating blood pressure and cardiovascular homeostasis by promoting vasodilation, natriuresis, and antagonizing the renin-angiotensin-aldosterone system. Therefore, this combo drug lessens sensitivity to natriuretic peptides and tackles the processes in hypertension that activate the renin-angiotensin-aldosterone system. This review provides an overview of how natriuretic peptides (NPs) contribute to blood pressure regulation for the treatment of hypertension through inhibiting neprilysin. It highlights the ARNi's dual action that works synergistically by blocking the harmful effects of angiotensin II on blood vessels while simultaneously increasing the levels of beneficial natriuretic peptides. Schematic representation of the mechanism of action of ARNi. Abbreviation: -Renin angiotensin aldosterone system (RAAS), Natriuretic peptides (NP), Atrial Natriuretic peptide (ANP), Brain natriuretic peptide (BNP), C-type natriuretic peptide (CNP), Angiotensin II (Ang II), Angiotensin receptor neprilysin inhibitor (ARNI).

SARS-CoV-2 Genomic Variants and Their Relationship with the Expressional and Genomic Profile of Angiotensin-Converting Enzyme 2 (ACE2) and Transmembrane Serine Protease 2 (TMPRSS2)

Over the past four years, angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2) have been extensively studied, given their important role in SARS-CoV-2 replication; however, most studies have failed to compare their behavior in the face of different SARS-CoV-2 genomic variants. Therefore, this study evaluated the influence of different variants in ACE2/TMPRSS2 expressional and genomic profiles. To achieve this, 160 nasopharyngeal samples, previously detected with SARS-CoV-2 via RT-qPCR (June 2020-July 2022), were quantified for ACE2/TMPRSS2 expression levels, also using RT-qPCR; SARS-CoV-2 genomic variants, along with polymorphisms in the ACE2/TMPRSS2 coding genes, were identified using nanopore sequencing. In order of appearance, the B.1.1.28, Zeta, Gamma, and Omicron variants were identified in this study. The ACE2 levels were higher when B.1.1.28 was present, possibly due to the ACE2/spike binding affinity; the TMPRSS2 levels were also higher in the presence of B.1.1.28, probably attributable to inefficient usage of the TMPRSS2 pathway by the other variants, as well as to the decrease in protease transcription factors when in the presence of Omicron. The rs2285666 (ACE2) polymorphism was less frequent when B.1.1.28 was present, which is befitting, since rs2285666 increases ACE2/spike binding affinity. In conclusion, SARS-CoV-2 genomic variants appear to exhibit varying impacts in regards to ACE2/TMPRSS2 genomic and expressional behavior.

NAD+ enhancers as therapeutic agents in the cardiorenal axis

Cardiorenal diseases represent a complex interplay between heart failure and renal dysfunction, being clinically classified as cardiorenal syndromes (CRS). Recently, the contributions of altered nicotinamide adenine dinucleotide (NAD+) metabolism, through deficient NAD+ synthesis and/or elevated consumption, have proved to be decisive in the onset and progress of cardiorenal disease. NAD+ is a pivotal coenzyme in cellular metabolism, being significant in various signaling pathways, such as energy metabolism, DNA damage repair, gene expression, and stress response. Convincing evidence suggests that strategies designed to boost cellular NAD+ levels are a promising therapeutic option to address cardiovascular and renal disorders. Here, we review and discuss the implications of NAD+ metabolism in cardiorenal diseases, focusing on the propitious NAD+ boosting therapeutic strategies, based on the use of NAD+ precursors, poly(ADP-ribose) polymerase inhibitors, sirtuin activators, and other alternative approaches, such as CD38 blockade, nicotinamide phosphoribosyltransferase activation and combined interventions.

Effect of the renin-angiotensin-aldosterone system inhibitors on time to nucleic acid negative conversion in hypertensive patients with SARS-CoV-2 omicron infection: a propensity score matching study

We examined the relationship between RAAS inhibitor use and Omicron infection in mildly symptomatic patients. This retrospective case-control observational study included 50,121 patients with mild Omicron infection from the largest "Fangcang" shelter hospital in Shanghai between April 9, 2022, and May 21, 2022. Using 1:1 propensity score matching (PSM), we classified 4394 COVID-19 patients into hypertension and non-hypertension groups, and 406 hypertensive patients into RAAS inhibitor and non-RAAS inhibitor groups. The risk of initial symptoms of infection, cumulative negative conversion rates, time to nucleic-acid negative conversion, and viral loads were compared. In the hypertension group, the median number of days for nucleic-acid negative conversion was 7.0 (IQR, 5.0-9.0), which was greater than non-hypertensive group (median (IQR) 6.0 (4.0-8.0), P < 0.001, Cohen's d = 0.29); the mean and minimum cycle threshold values (CT-values) were significantly lower (P < 0.001, Cohen's d = 0.23). In the RAAS inhibitors group, the median number of days for nucleic-acid negative conversion was 7.0 days (IQR, 5.0-9.0), which was shorter than the non-RAAS inhibitors group ([median (IQR)] 8.0 (6.0-10.0), P < 0.001, Cohen's d = 0.34), the cumulative negative conversion rates at 3-8 days being all higher than non-RAAS inhibitors groups (P < 0.05). The most significant difference in negative conversion rate between the RAAS inhibitor and non-RAAS inhibitor group was on the 4th day. No significant difference was observed in mean and minimum CT-values from RAAS inhibitor and non-RAAS inhibitor groups (P > 0.05). RAAS inhibitor use in patients with hypertension is associated with nucleic-acid negative conversion duration and negative conversion rate. RAAS inhibitors clearly do not aggravate or prolong COVID-19.

Effects of Licorice Functional Components Intakes on Blood Pressure: A Systematic Review with Meta-Analysis and NETWORK Toxicology

OBJECTIVE

To investigate the effects of licorice functional ingredient intake on blood pressure, explore its potential mechanisms of action, and provide safety information for personalized nutritional interventions in special populations and for the application of licorice-derived functional foods.

METHODS

PubMed, Cochrane Library, Medline, Embase, EBSCO, ScienceDirect, and Web of Science databases were searched from inception to 31 August 2024. Randomized controlled trials (RCTs) investigating the intake of licorice or its functional components were included. The range of continuous variables was assessed using the weighted mean difference (WMD) with 95% confidence intervals. Genes associated with hypertension were screened using an online database. Machine learning, receiver operating characteristic(ROC) curve analysis, molecular docking, and gene set enrichment analysis (GSEA) were employed to explore the potential mechanisms underlying licorice-induced blood pressure fluctuations.

RESULTS

Eight RCTs (541 participants) were included in the meta-analysis, which indicated interventions containing glycyrrhizic acid (GA) as the main component increased systolic blood pressure (SBP) and diastolic blood pressure (DBP) (SBP: WMD [95% CI] = 3.48 [2.74, 4.21], p < 0.001; DBP: WMD [95% CI] = 1.27 [0.76, 1.78], p < 0.001). However, interventions dominated by licorice flavonoids(LF) had no significant effect on SBP or DBP (SBP: WMD [95% CI] = 0.58 [-1.15, 2.31], p = 0.511; DBP: WMD [95% CI] = 0.17 [-1.53, 1.88], p = 0.843). Three machine learning algorithms identified five biomarkers associated with hypertension: calmodulin 3 (CALM3), cluster of differentiation 9 (CD9), growth factor independence 1B transcriptional repressor (GFI1B), myosin light chain kinase (MYLK), and Ras suppressor-1 (RSU1). After removing biomarkers with lower validity and reliability, GFI1B, MYLK, and RSU1 were selected for subsequent analysis. The network toxicology results suggested that GA and its metabolite glycyrrhetinic acid may act on GFI1B, MYLK, and RSU1, influencing blood pressure fluctuations by modulating nitrogen metabolism signaling pathways.

CONCLUSIONS

There were distinct differences in the effects of licorice functional components on blood pressure. Functional constituents dominated by GA were shown to increase both SBP and DBP, whereas those dominated by LF did not exhibit significant effects on blood pressure. The hypertensive mechanism of GA may involve the modulation of GFI1B, MYLK, and RSU1 to regulate nitrogen metabolic pathways.

Gustatory dysfunction and long COVID in Chinese patients with COVID-19: A 6-month follow-up study

AIMS

To evaluate long COVID of gustatory dysfunction and the associated risk factors regarding onset and recovery in Chinese patients.

METHODS

We conducted a cross-sectional study of patients with SARS-CoV-2 Omicron infection at Changxing Mobile Cabin Hospital in Shanghai, China, from March to May 2022. A prospective follow-up of patients with gustatory dysfunction was conducted at 6 months after discharge.

RESULTS

In total, 18.48% (241/1304) reported gustatory dysfunction. The 6-month follow-up response rate was 89.63% (216/241) and 74.02% recovered their taste sense within 1-3 weeks. A total of 20.37% of patients (44/216) presented with long COVID. Symptoms persisted for 12 patients (5.56%) after 6 months. Having multiple taste impairments (OR, 2.364; 95% CI, 1.286-4.348; p = 0.006) was associated with a higher risk of gustatory dysfunction with long COVID. Having received a COVID-19 vaccine booster was positively associated with taste sensation recovery (HR, 1.344; 95% CI, 1.012-1.785; p = 0.041).

CONCLUSIONS

About 20.37% of patients with COVID-19 might develop long COVID of gustatory dysfunction and 5.56% with persisting changes in their sense of taste. Most patients recovered taste sensations within 1-3 weeks after COVID-19 symptom onset and receiving a booster shot of the COVID-19 vaccine presented a protective effect on the taste sensation recovery.

Human placental mesenchymal stem cells transplantation repairs the alveolar epithelial barrier to alleviate lipopolysaccharides-induced acute lung injury

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are accompanied by high mortality rates and few effective treatments. Transplantation of human placental mesenchymal stem cells (hPMSCs) may attenuate ALI and the mechanism is still unclear. Our study aimed to elucidate the potential protective effect and therapeutic mechanism of hPMSCs against lipopolysaccharide (LPS)-induced ALI, An ALI model was induced by tracheal instillation of LPS into wild-type (WT) and angiotensin-converting enzyme 2 (ACE2) knockout (KO) male mice, followed by injection of hPMSCs by tail vein. Treatment with hPMSCs improved pulmonary histopathological injury, reduced pulmonary injury scores, decreased leukocyte count and protein levels in bronchoalveolar lavage fluid(BALF), protected the damaged alveolar epithelial barrier, and reversed LPS-induced upregulation of pro-inflammatory factors Interleukin-6 (IL-6) and Tumor necrosis factor-α(TNF-α) and downregulation of anti-inflammatory factor Interleukin-6(IL-10) in BALF. Moreover, administration of hPMSCs inhibited Angiotensin (Ang)II activation and promoted the expression levels of ACE2 and Ang (1-7) in ALI mice. Pathological damage, inflammation levels, and disruption of alveolar epithelial barrier in ALI mice were elevated after the deletion of ACE2 gene, and the Renin angiotensin system (RAS) imbalance was exacerbated. The therapeutic effect of hPMSCs was significantly reduced in ACE2 KO mice. Our findings suggest that ACE2 plays a key role in hPMSCs repairing the alveolar epithelial barrier to protect against ALI, laying a new foundation for the clinical treatment of ALI.

Spontaneous and evoked angiotensin II sniffer cell activity in the lamina terminalis in vitro

Angiotensin II (ANG II) has been shown to have central nervous system effects. Although tissue renin-angiotensin systems (RAS) have been demonstrated in multiple tissues, the existence of a brain RAS is still a matter of debate. These studies test for angiotensin release from brain slices prepared from adult male Sprague-Dawley rats and male and female renin knock-out rats using Chinese hamster ovary cells modified to express both the angiotensin II type 1 receptor and a fluorescent calcium indicator. Sniffer cells were placed on the slices and calcium transients were measured from those located on or adjacent to the median preoptic nucleus with and without stimulation of the subfornical organ. Bath application of tetrodotoxin (1 µM) significantly attenuated spontaneous events while abolishing evoked sniffer cell activity. Bath application of dl-AP4 (10 µM, glutamatergic antagonist) did not affect either spontaneous or evoked release. Incubating the slices with fluorocitrate to inactive astrocytes did not influence sniffer cell activity in the MnPO. Pharmacological experiments indicate that ANG II release is largely both renin (aliskiren 10 µM) and ACE-1 (captopril 100 µM) dependent. However, experiments with brain slices prepared from male and female Renin knock-out rats suggest that alternative synthetic pathways may exist. Finally, these studies demonstrate that increases in ANG II release are observed following 7 days of chronic intermittent hypoxia. These studies suggest the existence of a tissue-specific RAS in the brain that involves canonical and alternative ANG II synthetic pathways and is upregulated in an animal model of sleep apnea.NEW & NOTEWORTHY These studies used Chinese hamster ovary cells that were cloned to express an angiotensin receptor (At1ra) and a calcium indicator (R-GECO) to detect the release of angiotensin from brain slices containing the lamina terminalis of rats. Some of the experiments use tissue from renin knockout rats. The results support the existence of an angiotensin system in the brain that may involve alternative synthetic pathways and is upregulated by intermittent hypoxia.

Transplantation of human umbilical cord-derived mesenchymal stem cells improves age-related ovarian functional decline via regulating the local renin-angiotensin system on inflammation and oxidative stress

BACKGROUND

Age-related reproductive aging is a natural and irreversible physiological process, and delaying childbearing is increasingly common all over the world. Transplantation of mesenchymal stem cells (MSCs) is considered a new and effective therapy to restore ovarian function, but the relevant mechanisms remain unclear. Recently, it has been found that there is a local Renin-angiotensin system (RAS) in human ovary and it plays a key role.

METHODS

After collecting follicular fluid from women who received oocyte retrieval for pure male factor infertility, the level of RAS components in it were detected, and the correlation analysis by linear regression. Then, the in vivo experiments on female C57BL/6 mice were designed to measure ovarian function, and the transcription and translation levels of RAS pathway were detected by molecular biology methods. Moreover, the role of RAS in regulating inflammation and oxidative stress in the co-culture system were explored in in vitro experiments on KGN cells.

RESULTS

First, a total of 139 samples of analyzable follicular fluid were obtained. The local RAS of ovary, which is independent of systemic RAS (P > 0.05), is affected by age (Pearson r < 0, P < 0.05) and related to ovarian function, inflammation, oxidative stress indexes and assisted reproduction laboratory outcomes (P < 0.05). Next, the ovary/body weight of aging mice decreased significantly and serum sex hormones levels changed significantly (P < 0.01). The number of functional follicles decreased, while the atresia follicles increased (P < 0.05). After MSCs transplantation, all the above measures have been partially recovered (P < 0.05). Although several RAS components in aging ovary changed, MSCs only improved the expression level of AT1R (P < 0.05). Furthermore, the secretion ability and mitochondrial membrane potential of aging KGN cells decreased, while the intracellular ROS level and the aging cells ratio increased (P < 0.01). All the above measures have been partially recovered when co-cultured with MSCs (P < 0.05). After Ang(1-7) were added into the co-culture system, the above have been more significantly restored compared with Ang II (P < 0.05). Nevertheless, there was no statistical difference in estradiol level no matter which one was added (P > 0.05).

CONCLUSIONS

Together, our findings indicate that a novel possible mechanism to explain how stem cells restore age-related ovarian functional decline.

Exploring Angiotensin II and Oxidative Stress in Radiation-Induced Cataract Formation: Potential for Therapeutic Intervention

Radiation-induced cataracts (RICs) represent a significant public health challenge, particularly impacting individuals exposed to ionizing radiation (IR) through medical treatments, occupational settings, and environmental factors. Effective therapeutic strategies require a deep understanding of the mechanisms underlying RIC formation (RICF). This study investigates the roles of angiotensin II (Ang II) and oxidative stress in RIC development, with a focus on their combined effects on lens transparency and cellular function. Key mechanisms include the generation of reactive oxygen species (ROS) and oxidative damage to lens proteins and lipids, as well as the impact of Ang II on inflammatory responses and cellular apoptosis. While the generation of ROS from water radiolysis is well established, the impact of Ang II on RICs is less understood. Ang II intensifies oxidative stress by activating type 1 receptors (AT1Rs) on lens epithelial cells, resulting in increased ROS production and inflammatory responses. This oxidative damage leads to protein aggregation, lipid peroxidation, and apoptosis, ultimately compromising lens transparency and contributing to cataract formation. Recent studies highlight Ang II's dual role in promoting both oxidative stress and inflammation, which accelerates cataract development. RICs pose a substantial public health concern due to their widespread prevalence and impact on quality of life. Targeting Ang II signaling and oxidative stress simultaneously could represent a promising therapeutic approach. Continued research is necessary to validate these strategies and explore their efficacy in preventing or reversing RIC development.

Possible mechanisms of SARS-CoV-2-associated myocardial fibrosis: reflections in the post-pandemic era

Since December 2019, coronavirus disease 2019 (COVID-19) has been spreading worldwide with devastating immediate or long-term effects on people's health. Although the lungs are the primary organ affected by COVID-19, individuals infected with SARS-CoV-2 also develop systemic lesions involving multiple organs throughout the body, such as the cardiovascular system. Emerging evidence reveals that COVID-19 could generate myocardial fibrosis, termed "COVID-19-associated myocardial fibrosis." It can result from the activation of fibroblasts via the renin-angiotensin-aldosterone system (RAAS), transforming growth factor-β1 (TGF-β1), microRNAs, and other pathways, and can also occur in other cellular interactions with SARS-CoV-2, such as immunocytes, endothelial cells. Nonetheless, to gain a more profound insight into the natural progression of COVID-19-related myocardial fibrosis, additional investigations are necessary. This review delves into the underlying mechanisms contributing to COVID-19-associated myocardial fibrosis while also examining the antifibrotic potential of current COVID-19 treatments, thereby offering guidance for future clinical trials of these medications. Ultimately, we propose future research directions for COVID-19-associated myocardial fibrosis in the post-COVID-19 era, such as artificial intelligence (AI) telemedicine. We also recommend that relevant tests be added to the follow-up of COVID-19 patients to detect myocardial fibrosis promptly.

Causal relationship between antihypertensive drugs and Hashimoto's thyroiditis: a drug-target Mendelian randomization study

Introduction and objectives

Recent studies have indicated a potential association of hypertension with Hashimoto's thyroiditis (HT) and other autoimmune diseases, yet the impact of antihypertensive drugs on HT risk is not well understood.

Methods

We employed a drug-target Mendelian randomization approach to investigate the prolonged impact of 9 classes of antihypertensive medications on HT susceptibility in European and Asian populations. Genetic variants close to or within genes associated with the drug targets and systolic blood pressure (SBP) were utilized to mimic the effects of antihypertensive medications. We focused on drugs linked to a lower risk of coronary artery disease for our main analysis. We gathered genetic data on SBP and HT risk from comprehensive genome-wide association studies available for European and Asian groups. For a supplementary analysis, we used expression quantitative trait loci (eQTLs) related to drug target genes as proxies.

Results

Our analysis revealed that the use of calcium channel blockers (CCBs) is linked to a reduced risk of HT in both European (OR [95% CI]: 0.96 [0.95 to 0.98] per 1 mmHg decrease in SBP; p = 3.51×10-5) and Asian populations (OR [95% CI]: 0.28 [0.12, 0.66]; p = 3.54×10-3). Moreover, genetically mimicking the use of loop diuretics (OR [95% CI]: 0.94 [0.91, 0.97]; p = 3.57×10-5) and thiazide diuretics (0.98 [0.96, 0.99]; p = 3.83×10-3) showed a significant association with a decreased risk of HT only in European population. These outcomes were confirmed when eQTLs were employed to represent the effects of antihypertensive medications.

Conclusion

The study suggests that CCBs and diuretics could potentially reduce the risk of HT in different populations. Additional research is needed to assess the feasibility of repurposing antihypertensive medications for the prevention of HT.

Phytomedical compounds as promising therapeutic agents for COVID-19 targeting angiotensin-converting enzyme 2: a review

AIMS

The aim of the present review was to highlight natural product investigations in silico and in vitro to find plants and chemicals that inhibit or stimulate angiotensin-converting enzyme 2 (ACE-2).

BACKGROUND

The global reduction of incidents and fatalities attributable to infections with SARS-CoV-2 is one of the most public health problems. In the absence of specific therapy for coronavirus disease 2019 (COVID-19), phytocompounds generated from plant extracts may be a promising strategy worth further investigation, motivating researchers to evaluate the safety and anti-SARS-CoV-2 effectiveness of these ingredients.

OBJECTIVE

To review phytochemicals in silico for anti-SARS-CoV-2 activity and to assess their safety and effectiveness in vitro and in vivo.

METHODS

The present review was conducted using various scientific databases and studies on anti-SARS-CoV-2 phytochemicals were analyzed and summarized. The results obtained from the in silico screening were subjected to extraction, isolation, and purification. The in vitro studies on anti-SarcoV-2 were also included in this review. In addition, the results of this research were interpreted, analyzed, and documented on the basis of the bibliographic information obtained.

RESULTS

This review discusses recent research on using natural remedies to cure or prevent COVID-19 infection. The literature analysis shows that the various herbal preparations (extracts) and purified compounds can block the replication or entrance of the virus directly to carry out their anti-SARS-CoV-2 effects. It is interesting to note that certain items can prevent SARS-CoV-2 from infecting human cells by blocking the ACE-2 receptor or the serine protease TMPRRS2. Moreover, natural substances have been demonstrated to block proteins involved in the SARS-CoV-2 life cycle, such as papain- or chymotrypsin-like proteases.

CONCLUSION

The natural products may have the potential for use singly or in combination as alternative drugs to treat/prevent COVID-19 infection, including blocking or stimulating ACE-2. In addition, their structures may provide indications for the development of anti-SARS-CoV-2 drugs.

A comprehensive review of finerenone-a third-generation non-steroidal mineralocorticoid receptor antagonist

Multiple studies have shown that finerenone (BAY 94-8862), a third-generation non-steroidal mineralocorticoid receptor antagonist (MRA), possesses different or superior mechanisms of action to traditional MRAs. Specifically, animal and cell-based experiments have demonstrated that this compound exerts multiple effects including fibrosis inhibition, reduced pulmonary artery pressure, improved diabetic retinopathy, enhanced endothelial functions, metabolic optimization as well as reduced oxidative stress, thereby exerting overall positive effects on renal and cardiovascular diseases. Consequently, clinical research, such as the FIGARO-DKD and FIDELIO-DKD trials, has demonstrated dual benefits for patients with type 2 diabetes mellitus and chronic kidney disease (T2DM-CKD), especially by validating MRAs' potential in reducing risks of renal and cardiovascular composite endpoints. Currently, cardiovascular indications for finerenone are limited to patients with T2DM-CKD, while its use in non-T2DM CKD patients remains at clinical trial stages. Despite showing good safety and efficacy in T2DM-CKD patients, there are insufficient corresponding data for those presenting chronic kidney disease without diabetes (ndCKD). Furthermore, the application of this compound in diseases such as primary aldosteronism and its association with cancer risk need to be further validated through larger-scale and longer-term clinical studies. Nevertheless, the development of finerenone provides an additional option for treating cardiovascular and renal diseases. With further research, it is expected that finerenone will be relevant to a broader range of CKD patient populations by addressing current knowledge gaps to comprehensively evaluate its clinical value and potentially alter existing treatment strategies. The current review aims to comprehensively analyze the basic research and clinical advancements involving finerenone in order to explore its prospects for treating cardiovascular and renal diseases, while addressing unmet needs in current treatment strategies. Additionally, through a comprehensive analysis of relevant research findings, a deeper understanding of finerenone's drug characteristics will be provided alongside scientific guidance for future treatment strategies and their clinical significance.

Mortality and Health Outcomes Among Patients With Sarcoidosis Treated With Angiotensin-Converting Enzyme Inhibitors and Angiotensin Receptor Blockers

BACKGROUND

Sarcoidosis is a multisystem inflammatory disease in which management and outcomes can vary widely. The renin-angiotensin-aldosterone system (RAAS) has been implicated in its pathogenesis, yet the impact of RAAS modulators on health outcomes in sarcoidosis remains poorly understood.

RESEARCH QUESTION

How do pharmacologic modulators of RAAS affect health outcomes in patients with a diagnosis of sarcoidosis?.

STUDY DESIGN AND METHODS

We conducted a large multicenter investigation using the TriNetX Research Network database. Patients included in this study were individuals with a diagnosis of sarcoidosis who were prescribed either an angiotensin-converting enzyme inhibitor (ACEI) or an angiotensin receptor blocker (ARB). All cohorts were matched for important covariates, and outcomes measured included mortality, cardiac and respiratory outcomes, and sepsis rates after sarcoidosis diagnosis.

RESULTS

We observed an increased mortality risk among patients with sarcoidosis prescribed ACEIs compared with patients prescribed ARB therapies. Furthermore, patients with sarcoidosis prescribed ACEIs showed worse cardiac and respiratory outcomes and increased sepsis rates compared with the ARB cohort.

INTERPRETATION

Our findings suggest that ACEIs and ARBs have divergent effects on outcomes in patients with sarcoidosis. These findings highlight the potential pathogenic role of RAAS signaling in this disease and underscore the importance of carefully selecting RAAS modulators for individuals with sarcoidosis.

Immune mediators in heart-lung communication

It is often the case that serious, end-stage manifestations of disease result from secondary complications in organs distinct from the initial site of injury or infection. This is particularly true of diseases of the heart-lung axis, given the tight anatomical connections of the two organs within a common cavity in which they collectively orchestrate the two major, intertwined circulatory pathways. Immune cells and the soluble mediators they secrete serve as effective, and targetable, messengers of signals between different regions of the body but can also contribute to the spread of pathology. In this review, we discuss the immunological basis of interorgan communication between the heart and lung in various common diseases, and in the context of organ crosstalk more generally. Gaining a greater understanding of how the heart and lung communicate in health and disease, and viewing disease progression generally from a more holistic, whole-body viewpoint have the potential to inform new diagnostic approaches and strategies for better prevention and treatment of comorbidities.

Assessment of per- and poly-fluoroalkyl substances and physiological biomarkers in aquarium-based bottlenose dolphins and killer whales

Environmental concerns about per- and polyfluoroalkyl substances (PFAS) are considerably increasing due to their extensive use in commercial and consumer products. PFAS bioaccumulate and biomagnify throughout the food chain, and their toxicity and potential adverse health effects can potentially represent a threat to living organisms. In this study, we described PFAS profiles in the serum of two species of zoo-based bottlenose dolphins (Tursiops truncatus, n = 14 individuals) and killer whales (Orcinus orca, n = 14 individuals) from three locations (California, Florida, and Texas, USA), from 1994 to 2020. Potential physiological effects of PFAS were also explored by measuring different biomarkers (cortisol, corticosterone, aldosterone, TBARS, and hydrogen peroxide) while accounting for individual age, sex, and reproductive stage. All PFAS were detected in at least one of the individuals, considering both species. ΣPFAS reached 496 ng mL-1 in bottlenose dolphins and 230 ng mL-1 in killer whales. In both species, the PFAS with higher mean concentrations were PFOS (108.0-183.0 ng ml-1) and PFNA (14.40-85.50 ng ml-1), which are long-chain compounds. Newborn individuals of both species were also exposed to PFAS, indicating transference via placenta and lactation. Linear mixed model analyses indicated significant correlations between aldosterone, month, year, location, and status; and between hydrogen peroxide, month, year, age, status, ΣPFAS, and Σ short-chain PFAS in killer whales suggesting seasonal variations related to the animal's physiological state (e.g., reproductive cycles, stress responses, weaning events) and increased reactive oxygen species formation due to PFAS exposure. Given our results, other contaminant classes should be investigated in cetaceans as they might have additive and synergistic detrimental effects on these individuals. This study lays the foundation to guide future researchers and highlights the importance of such assessments for animal welfare, and species conservation. Our results may inform management decisions regarding regulations of contaminant thresholds in delphinids.

The role of sex hormones in aldosterone biosynthesis and their potential impact on its mineralocorticoid receptor

Blood pressure (BP) regulation is a complex process involving various hormones, including aldosterone and its mineralocorticoid receptor. Mineralocorticoid receptor is expressed in several tissues, including the kidney, and plays a crucial role in regulating BP by controlling the sodium and water balance. During different stages of life, hormonal changes can affect mineralocorticoid receptor activity and aldosterone levels, leading to changes in BP. Increasing evidence suggests that sex steroids modulate aldosterone levels. Estrogens, particularly estradiol, mediate aldosterone biosynthesis by activating classical estrogen receptors and the G protein-coupled receptor. Progesterone acts as an anti-mineralocorticoid by inhibiting the binding of aldosterone to the mineralocorticoid receptor. Moreover, progesterone inhibits aldosterone synthase enzymes. The effect of testosterone on aldosterone synthesis is still a subject of debate. However, certain studies show that testosterone downregulates the mRNA levels of aldosterone synthase, leading to decreased plasma aldosterone levels.

Macrophages in vascular disease: Roles of mitochondria and metabolic mechanisms

Macrophages are a dynamic cell type of the immune system implicated in the pathophysiology of vascular diseases and are a major contributor to pathological inflammation. Excessive macrophage accumulation, activation, and polarization is observed in aortic aneurysm (AA), atherosclerosis, and pulmonary arterial hypertension. In general, macrophages become activated and polarized to a pro-inflammatory phenotype, which dramatically changes cell behavior to become pro-inflammatory and infiltrative. These cell types become cumbersome and fail to be cleared by normal mechanisms such as autophagy. The result is a hyper-inflammatory environment causing the recruitment of adjacent cells and circulating immune cells to further augment the inflammatory response. In AA, this leads to excessive ECM degradation and chemokine secretion, ultimately causing macrophages to dominate the immune cell landscape in the aortic wall. In atherosclerosis, monocytes are recruited to the vascular wall, where they polarize to the pro-inflammatory phenotype and induce inflammatory pathway activation. This leads to the development of foam cells, which significantly contribute to neointima and necrotic core formation in atherosclerotic plaques. Pro-inflammatory macrophages, which affect other vascular diseases, present with fragmented mitochondria and corresponding metabolic dysfunction. Targeting macrophage mitochondrial dynamics has proved to be an exciting potential therapeutic approach to combat vascular disease. This review will summarize mitochondrial and metabolic mechanisms of macrophage activation, polarization, and accumulation in vascular diseases.

Radiotracers for Molecular Imaging of Angiotensin-Converting Enzyme 2

Angiotensin-converting enzymes (ACE) are well-known for their roles in both blood pressure regulation via the renin-angiotensin system as well as functions in fertility, immunity, hematopoiesis, and many others. The two main isoforms of ACE include ACE and ACE-2 (ACE2). Both isoforms have similar structures and mediate numerous effects on the cardiovascular system. Most remarkably, ACE2 serves as an entry receptor for SARS-CoV-2. Understanding the interaction between the virus and ACE2 is vital to combating the disease and preventing a similar pandemic in the future. Noninvasive imaging techniques such as positron emission tomography and single photon emission computed tomography could noninvasively and quantitatively assess in vivo ACE2 expression levels. ACE2-targeted imaging can be used as a valuable tool to better understand the mechanism of the infection process and the potential roles of ACE2 in homeostasis and related diseases. Together, this information can aid in the identification of potential therapeutic drugs for infectious diseases, cancer, and many ACE2-related diseases. The present review summarized the state-of-the-art radiotracers for ACE2 imaging, including their chemical design, pharmacological properties, radiochemistry, as well as preclinical and human molecular imaging findings. We also discussed the advantages and limitations of the currently developed ACE2-specific radiotracers.

Differential gene expression in the kidneys of SHR and WKY rats after intravenous administration of Akkermansia muciniphila-derived extracellular vesicles

Although Akkermansia muciniphila (Am) plays a beneficial role as a probiotic in the treatment of metabolic syndrome, the mechanisms remain elusive. We tested the hypothesis that Am extracellular vesicles (AmEVs) protect against hypertension through modulation of gene expression in the kidneys of spontaneously hypertensive rats (SHRs). Extracellular vesicles purified from anaerobically cultured Am (1.0 × 108 or 1.0 × 109 particles/kg) or vehicles were injected into the tail veins of Wistar-Kyoto rats (WKYs) and SHRs weekly for 4 weeks. Renal cortical tissues isolated from both rat strains were analyzed by trichrome stain and RT-qPCR. AmEVs protect against the development of hypertension in SHRs without a serious adverse reaction. AmEVs increased the expression of vasocontracting Agt and At1ar as well as vasodilating At2r, Mas1 and Nos2 in the kidneys of both strains. These results indicate that AmEVs have a protective effect against hypertension without a serious adverse reaction. Therefore, it is foreseen that AmEVs may be utilized as a novel therapeutic for the treatment of hypertension.

Clinical Properties and Non-Clinical Testing of Mineralocorticoid Receptor Antagonists in In Vitro Cell Models

Mineralocorticoid receptor antagonists (MRAs) are one of the renin-angiotensin-aldosterone system inhibitors widely used in clinical practice. While spironolactone and eplerenone have a long-standing profile in clinical medicine, finerenone is a novel agent within the MRA class. It has a higher specificity for mineralocorticoid receptors, eliciting less pronounced adverse effects. Although approved for clinical use in patients with chronic kidney disease and heart failure, intensive non-clinical research aims to further elucidate its mechanism of action, including dose-related selectivity. Within the field, animal models remain the gold standard for non-clinical testing of drug pharmacological and toxicological properties. Their role, however, has been challenged by recent advances in in vitro models, mainly through sophisticated analytical tools and developments in data analysis. Currently, in vitro models are gaining momentum as possible platforms for advanced pharmacological and pathophysiological studies. This article focuses on past, current, and possibly future in vitro cell models research with clinically relevant MRAs.

Are Hair Scalp Trace Elements Correlated with Atherosclerosis Location in Coronary Artery Disease?

Coronary artery disease is among the leading current epidemiological challenges. The genetic, clinical, and lifestyle-related risk factors are well documented. The reason for specific epicardial artery locations remains unsolved. The coronary artery topography and blood flow characteristics may induce local inflammatory activation. The atherosclerotic plaque formation is believed to represent inflammatory response involving enzymatic processes co-factored by trace elements. The possible relation between trace elements and coronary artery disease location was the subject of the study. There were 175 patients (107 (61) men and 68 (39) females) in a median (Q1-3) age of 71 years (65-76) admitted for coronary angiography due to chronic coronary syndrome. The angiographic results focused on the percentage of lumen stenosis in certain arteries and were compared with the results for hair scalp trace elements. The correlation between left main coronary artery atherosclerotic plaques and nickel (Ni), zinc (Zn), and antimony (Sb) hair scalp concentration was noted. The analysis revealed a positive relation between left descending artery disease and chromium (Cr), sodium (Na), arsenic (As), and molybdenum (Mo) and a negative correlation with strontium (Sr). The atherosclerotic lesion in the circumflex artery revealed correlations in our analysis with sodium (Na), potassium (K), chromium (Cr), nickel (Ni), arsenic (As), and negative with strontium (Sr) (r) hair scalp concentrations. The negative correlations between right coronary artery disease and magnesium (Mg) and strontium (Sr) concentrations were noted. The possible explanation of different epicardial artery involvement and severity by atherosclerotic processes may lay in their topography and blood rheological characteristics that induce different inflammatory reactions co0factored by specific trace elements. The trace element concentration in the hair scalp may correlate with a particular coronary atherosclerotic involvement, including the severity of lumen reduction. This may indicate the missing link between the pathophysiological processes of atherosclerosis development and its location in coronary arteries.

Potential Effects of Hyperglycemia on SARS-CoV-2 Entry Mechanisms in Pancreatic Beta Cells

The COVID-19 pandemic has revealed a bidirectional relationship between SARS-CoV-2 infection and diabetes mellitus. Existing evidence strongly suggests hyperglycemia as an independent risk factor for severe COVID-19, resulting in increased morbidity and mortality. Conversely, recent studies have reported new-onset diabetes following SARS-CoV-2 infection, hinting at a potential direct viral attack on pancreatic beta cells. In this review, we explore how hyperglycemia, a hallmark of diabetes, might influence SARS-CoV-2 entry and accessory proteins in pancreatic β-cells. We examine how the virus may enter and manipulate such cells, focusing on the role of the spike protein and its interaction with host receptors. Additionally, we analyze potential effects on endosomal processing and accessory proteins involved in viral infection. Our analysis suggests a complex interplay between hyperglycemia and SARS-CoV-2 in pancreatic β-cells. Understanding these mechanisms may help unlock urgent therapeutic strategies to mitigate the detrimental effects of COVID-19 in diabetic patients and unveil if the virus itself can trigger diabetes onset.

Gene expression in heart, kidney, and liver identifies possible mechanisms underpinning fetal resistance and susceptibility to in utero PRRSV infection

Porcine reproductive and respiratory syndrome (PRRS) is one of the costliest diseases to pork producers worldwide. We tested samples from the pregnant gilt model (PGM) to better understand the fetal response to in-utero PRRS virus (PRRSV) infection. Our goal was to identify critical tissues and genes associated with fetal resilience or susceptibility. Pregnant gilts (N=22) were infected with PRRSV on day 86 of gestation. At 21 days post maternal infection, the gilts and fetuses were euthanized, and fetal tissues collected. Fetuses were characterized for PRRS viral load in fetal serum and thymus, and preservation status (viable or meconium stained: VIA or MEC). Fetuses (N=10 per group) were compared: uninfected (UNIF; <1 log/µL PRRSV RNA), resilient (HV_VIA, >5 log virus/µL but viable), and susceptible (HV_MEC, >5 log virus/µL with MEC). Gene expression in fetal heart, kidney, and liver was investigated using NanoString transcriptomics. Gene categories investigated were hypothesized to be involved in fetal response to PRRSV infection: renin- angiotensin-aldosterone, inflammatory, transporter and metabolic systems. Following PRRSV infection, CCL5 increased expression in heart and kidney, and ACE2 decreased expression in kidney, each associated with fetal PRRS susceptibility. Liver revealed the most significant differential gene expression: CXCL10 decreased and IL10 increased indicative of immune suppression. Increased liver gene expression indicated potential associations with fetal PRRS susceptibility on several systems including blood pressure regulation (AGTR1), energy metabolism (SLC16A1 and SLC16A7), tissue specific responses (KL) and growth modulation (TGFB1). Overall, analyses of non-lymphoid tissues provided clues to mechanisms of fetal compromise following maternal PRRSV infection.

Angiotensinergic effect of β-Caryophyllene on Lipopolysaccharide- induced systemic inflammation

Renin-Angiotensin System (RAS) is a peptidergic system, canonically known for its role in blood pressure regulation. Furthermore, a non-canonical RAS regulates pathophysiological phenomena, such as inflammation since it consists of two main axes: the pro-inflammatory renin/(pro)renin receptor ((P)RR) axis, and the anti-inflammatory angiotensin-converting enzyme 2 (ACE2)/Angiotensin-(1-7) (Ang-(1-7))/Mas Receptor (MasR) axis. Few phytochemicals have shown to exert angiotensinergic and anti-inflammatory effects through some of these axes; nevertheless, anti-inflammatory drugs, such as phytocannabinoids have not been studied regarding this subject. Among phytocannabinoids, β-Caryophyllene stands out as a dietary phytocannabinoid with antiphlogistic activity that possess a unique sesquiterpenoid structure. Although its cannabinergic effect has been studied, its angiotensinergic effect reminds underexplored. This study aims to explore the angiotensinergic effect of β-Caryophyllene on inflammation and stress at a systemic level. After intranasal Lipopolysaccharide (LPS) installation and oral treatment with β-Caryophyllene, the concentration and activity of key RAS elements in the serum, such as Renin, ACE2 and Ang-(1-7), along with the stress hormone corticosterone and pro/anti-inflammatory cytokines, were measured in mice serum. The results show that β-Caryophyllene treatment modified RAS levels by increasing Renin and Ang-(1-7), alongside the reduction of pro-inflammatory cytokines and corticosterone levels. These results indicate that β-Caryophyllene exhibits angiotensinergic activity in favor of anti-inflammation.

Evidence of a causal relationship between blood pressure and pathological scars: a bidirectional Mendelian randomization study

Background

Recent advancements in basic medicine and epidemiology suggest a potential influence of blood pressure on scar formation, yet the specifics of this relationship are not fully understood. This study aims to clarify the causal link between blood pressure and the development of pathological scars using Mendelian randomization (MR).

Methods

This study employed genetic variants closely linked to blood pressure as instrumental variables to explore the relationship between blood pressure and pathological scars. The inverse variance weighted (IVW) method was used for analysis.

Results

Our analysis identified a notable association where higher blood pressure was correlated with a lower risk of pathological scars. Specifically, an increase in diastolic blood pressure (odds ratio [OR] per standard deviation increase: 0.67 [95% Confidence Interval [CI], 0.49-0.99]), systolic blood pressure (OR per standard deviation increase: 0.66 [95% CI, 0.46-0.93]), and hypertension (pooled OR: 0.39 [95% CI, 0.18-0.85]) were significantly associated with a reduced risk of keloids. Similarly, a genetic predisposition to hypertension (pooled OR: 0.31 [95% CI, 0.11-0.89]) was significantly associated with a reduced risk of hypertrophic scars. Neither reverse MR analysis nor Steiger's test indicated a significant reverse causal relationship between hypertension and either keloids or hypertrophic scars.

Conclusion

The findings suggest a protective role of higher blood pressure against the development of pathological scars, including keloids and hypertrophic scars. However, the inconsistency observed across different MR methods warrants cautious interpretation and underscores the need for further investigation to confirm these findings.

Moderating effect of a sodium-rich diet on the association between long-term exposure to fine particulate matter and blood lipids in children and adolescents

BACKGROUND

Several studies reported that exposure to higher levels of fine particulate matter (PM2.5) was associated with deteriorated lipid profiles in children and adolescents. However, whether a sodium-rich diet could modify the associations remains unknown. We aimed to examine the associations of long-term exposure to PM2.5 with blood lipids in children and adolescents, and further examine the effect modification by dietary and urinary sodium levels based on a multi-community population in China.

METHODS

The 3711 study participants were from a cross-sectional study, which interviewed children and adolescents aged 6 to 17 years across Sichuan Province, China between 2015 and 2017. Blood lipid outcomes including blood total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG) were assessed. Information on daily dietary sodium consumption was estimated with a semi-quantitative food frequency questionnaire (FFQ), and urinary sodium was used as an internal exposure biomarker. A linear regression model was applied to estimate the associations of prior 2-years' average exposure to ambient PM2.5 with blood lipids. The effect modification by dietary and urinary sodium was examined by stratified analyses.

RESULTS

The participants from rural areas had higher levels of daily sodium consumptions. The results of multivariable regression analysis indicated that per 10 μg/m3 incremental change in PM2.5 was associated with a 1.56% (95% confidence interval 0.90%-2.23%) and a 2.26% (1.15%-3.38%) higher blood TC and LDL-C levels, respectively. Among the study participants with higher levels of dietary sodium or urinary sodium, exposure to higher levels of PM2.5 was significantly associated with deteriorated lipid profiles. For example, each 10 μg/m3 incremental change in exposure to PM2.5 was correlated with a 2.83 (-4.65 to -0.97) lower percentage decrease in blood HDL-C levels among the participants who were from the highest quartile of urinary sodium levels. While, these associations changed to be nonsignificant in the participants who were from the lowest quartile of dietary sodium levels.

CONCLUSION

Exposure to higher levels of PM2.5 was associated with deteriorated blood lipid levels in children and adolescents. It is noteworthy that these associations might be ameliorated through the adoption of a low-sodium dietary regimen.

Association between the triglyceride glucose index and the risk of acute kidney injury in critically ill patients with hypertension: analysis of the MIMIC-IV database

Background

The triglyceride glucose (TyG) index, a metric computed from the levels of fasting triglyceride (TG) and fasting plasma glucose (FPG), has emerged as a simple surrogate measure for insulin resistance (IR) in recent years. In multiple critical care scenarios, such as contrast-induced acute kidney injury (AKI) and cardiorenal syndrome, a high TyG index levels shows a notable correlation with AKI incidence. However, its predictive value for AKI in critically ill hypertensive patients remains uncertain.

Methods

Participants were selected from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database and divided into quartiles based on the TyG index. The primary focus of the study was to investigate the risk of acute kidney injury (AKI), with in-hospital mortality as a secondary endpoint, assessed among all study subjects as well as specifically among AKI patients. The use of renal replacement therapy (RRT), indicative of AKI progression, was also considered a secondary endpoint reflecting renal outcomes. To explore the correlation between the TyG index and AKI risk in critically ill hypertensive patients, the study employed a restricted cubic splines model and Cox proportional hazards (CPH) models. Additionally, Kaplan-Meier survival analysis was utilized to assess differences in primary and secondary outcomes across groups categorized by their TyG index. Analyses were conducted to ensure the consistency of the predictive capability of TyG index across various subgroups.

Results

Our study included 4,418 participants, with 57% being male patients. AKI occurred in 56.1% of cases. Through the CPH analysis, we identified a significant association between the TyG index and AKI occurrence in critically ill hypertensive patients. With the help of a restricted cubic splines model, we observed a direct relationship between an elevated TyG index and an increased AKI. Subgroup examinations consistently proved the predictive value of the TyG index across categories. Furthermore, Kaplan-Meier survival analysis revealed notable differences in RRT among AKI patients.

Conclusion

The findings underscore the importance of the TyG index as a reliable predictor for the occurrence of AKI and adverse renal outcomes among hypertensive patients in critical ill states. Nevertheless, validating causality mandates extensive prospective investigations.

The Angiotensin Metabolite His-Leu Is a Strong Copper Chelator Forming Highly Redox Active Species

His-Leu is a hydrolytic byproduct of angiotensin metabolism, whose concentration in the bloodstream could be at least micromolar. This encouraged us to investigate its Cu(II) binding properties and the concomitant redox reactivity. The Cu(II) binding constants were derived from isothermal titration calorimetry and potentiometry, while identities and structures of complexes were obtained from ultraviolet-visible, circular dichroism, and room-temperature electronic paramagnetic resonance spectroscopies. Four types of Cu(II)/His-Leu complexes were detected. The histamine-like complexes prevail at low pH. At neutral and mildly alkaline pH and low Cu(II):His-Leu ratios, they are superseded by diglycine-like complexes involving the deprotonated peptide nitrogen. At His-Leu:Cu(II) ratios of ≥2, bis-complexes are formed instead. Above pH 10.5, a diglycine-like complex containing the equatorially coordinated hydroxyl group predominates at all ratios tested. Cu(II)/His-Leu complexes are also strongly redox active, as demonstrated by voltammetric studies and the ascorbate oxidation assay. Finally, numeric competition simulations with human serum albumin, glycyl-histydyl-lysine, and histidine revealed that His-Leu might be a part of the low-molecular weight Cu(II) pool in blood if its abundance is >10 μM. These results yield further questions, such as the biological relevance of ternary complexes containing His-Leu.

Persistent Vascular Complications in Long COVID: The Role of ACE2 Deactivation, Microclots, and Uniform Fibrosis

Angiotensin-converting enzyme 2 (ACE2), a key regulator in vasoregulation and the renin-angiotensin system, is hypothesized to be downregulated in patients with COVID-19, leading to a cascade of cardiovascular complications. This deactivation potentially results in increased blood pressure and vessel injury, contributing to the formation and persistence of microclots in the circulation. Herein, we propose a hypothesis regarding the prolonged vascular complications observed in long COVID, focusing on the role of ACE2 deactivation and/or shedding, the persistence of microclots, and the unique pattern of fibrosis induced by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). Furthermore, we propose that the distinctive, uniform fibrosis associated with COVID-19, which is challenging to detect through conventional X-ray imaging, exacerbates vascular injury and impairs oxygenation. The persistence of these microclots and the unique fibrosis pattern are suggested as key factors in the extended duration of vascular complications post-COVID-19 infection, regardless of the initial disease severity. Moreover, plasma ACE2 activity has the potential to serve as prognostic or diagnostic biomarkers for monitoring disease severity and managing long COVID symptoms. Elucidating the role of ACE2 deactivation and the consequent events is vital for understanding the long-term effects of COVID-19. The experimental verification of this hypothesis through in vitro studies, clinical longitudinal studies, and advanced imaging techniques could yield significant insights into the pathophysiological mechanisms underlying long COVID, thereby improving the management of patients, particularly those with cardiovascular complications.

Get reliable laboratory findings - how to recognize the deceptive effects of angiotensin-converting enzyme inhibitor therapy in the laboratory diagnostics of sarcoidosis?

OBJECTIVES

Serum angiotensin-converting enzyme (ACE) is the only biomarker routinely used in the laboratory diagnostics of sarcoidosis, and ACE inhibitor (ACEi) drugs are among the most prescribed drugs worldwide. Taking ACEi can mislead medical teams by lowering ACE activity, delaying diagnosis and giving a false impression of disease activity of sarcoidosis. We aimed to develop a simple method to detect the presence of ACEi drugs in samples, to investigate the ACEi medication-caused interference and consequences in a retrospective study.

METHODS

ACE activity and the level of ACE inhibition were determined for 1823 patients with suspected sarcoidosis. These values were compared with the therapeutic information at the first and follow-up visits.

RESULTS

A total of 302 patients had biochemical evidence of an ACEi drug effect during diagnostic ACE activity testing. In their case, ACE activity was significantly lower (median(IQR): 4.41 U/L(2.93-6.72)) than in patients not taking ACEi (11.32 U/L(8.79-13.92), p<0.01). In 62 sarcoidosis patients, the ACEi reduced ACE activity to the reference range or below. Only in 40 % of the cases was the medication list recorded in the outpatient chart and only in 3 cases was low ACE activity associated with ACEi use. 67 % of the repeated ACE activity measurements were also performed during ACEi therapy.

CONCLUSIONS

Our study revealed that the use of ACEi is common in patients with suspected sarcoidosis. The ACE activity lowering effect of ACEi drugs may escape the attention of medical teams which can lead to diagnostic errors and unnecessary tests. Nevertheless, these pitfalls can be avoided by using a method suggested by our team.

Cell type-specific expression of angiotensin receptors in the human lung with implications for health, aging, and chronic disease

The renin-angiotensin system is a highly characterized integrative pathway in mammalian homeostasis whose clinical spectrum has been expanded to lung disorders such as chronic obstructive pulmonary disease (COPD)-emphysema, idiopathic pulmonary fibrosis (IPF), and COVID pathogenesis. Despite this widespread interest, specific localization of this receptor family in the mammalian lung is limited, partially due to the imprecision of available antibody reagents. In this study, we establish the expression pattern of the two predominant angiotensin receptors in the human lung, AGTR1 and AGTR2, using complementary and comprehensive bulk and single-cell RNA-sequence datasets that are publicly available. We show these two receptors have distinct localization patterns and developmental trajectories in the human lung, pericytes for AGTR1 and a subtype of alveolar epithelial type 2 cells for AGTR2. In the context of disease, we further pinpoint AGTR2 localization to the COPD-associated subpopulation of alveolar epithelial type 2 (AT2B) and AGTR1 localization to fibroblasts, where their expression is upregulated in individuals with COPD, but not in individuals with IPF. Finally, we examine the genetic variation of the angiotensin receptors, finding AGTR2 associated with lung phenotype (i.e., cystic fibrosis) via rs1403543. Together, our findings provide a critical foundation for delineating this pathway's role in lung homeostasis and constructing rational approaches for targeting specific lung disorders.

A comprehensive exploration of novel biomarkers for the early diagnosis of aortic dissection

Aortic dissection (AD) is a catastrophic life-threatening cardiovascular emergency with a 1-2% per hour mortality rate post-diagnosis, characterized physiologically by the separation of aortic wall layers. AD initially presents as intense pain that can then radiate to the back, arms, neck, or jaw along with neurological deficits like difficulty in speaking, and unilateral weakness in some patients. This spectrum of clinical features associated with AD is often confused with acute myocardial infarction, hence leading to a delay in AD diagnosis. Cardiac and vascular biomarkers are structural proteins and microRNAs circulating in the bloodstream that correlate to tissue damage and their levels become detectable even before symptom onset. Timely diagnosis of AD using biomarkers, in combination with advanced imaging diagnostics, will significantly improve prognosis by allowing earlier vascular interventions. This comprehensive review aims to investigate emerging biomarkers in the diagnosis of AD, as well as provide future directives for creating advanced diagnostic tools and imaging techniques.

Quantification of endogenous Angiotensin 1-10, 1-9, 1-8, 1-7, and 1-5 in human plasma using micro-UHPLC-MS/MS: Outlining the importance of the pre-analytics for reliable results

Angiotensin peptides (ANGs) play a central role in the renin-angiotensin-aldosterone system, rendering them interesting biomarkers associated with hypertension. Precise quantification of circulating ANGs holds the potential to assess the activity of angiotensin-converting enzyme (ACE), a key protease targeted by widely prescribed drugs, namely ACE inhibitors. This ability could pave the way for personalised medicine, offering insights into the prescription of inhibitors targeting either the proteases or the receptors within the system. Despite recent developments in liquid chromatography-mass spectrometry (LC-MS) methods for measuring circulating ANG concentrations, comprehensive stability studies of ANGs in human plasma are absent in the literature, raising concerns about the reliability of measured concentrations and their link to clinical conditions. To address this critical gap, we conducted an exhaustive evaluation of the pre-analytical stability of ANG1-10, ANG1-9, ANG1-8, ANG1-7, and ANG1-5. By employing surfactants to mitigate non-specific adsorption and a dedicated mix of protease inhibitors to limit protease activity, we established an MS-based assay for these five peptides. We used this method to quantify circulating concentrations of ANGs in the plasma of 11 healthy donors and 3 patients under kidney dialysis. Our findings revealed that ANG1-10 and ANG1-8 circulate at concentrations ranging from 1 to 10 pM in healthy subjects and exhibit a high degree of correlation. Notably, ANG1-9, ANG1-7, and ANG1-5 were undetectable in any of the 14 patients, despite a sub-picomolar limit of detection. This strikingly contrasts with the reference concentrations reported in the literature, which typically fall within the picomolar range. In light of these discrepancies, we strongly advocate for rigorous pre-analytical considerations and comprehensive stability studies to ensure reliable results. We emphasise the pivotal role of heightened pre-analytical awareness within the clinical chemistry community, and we hope for continued growth in this critical area.

Angiotensin receptor blocker-neprilysin inhibitor for heart failure with reduced ejection fraction

Heart failure with reduced ejection fraction (HFrEF) is a clinical syndrome characterized by volume overload, impaired exercise capacity, and recurrent hospital admissions. A major contributor to the pathophysiology and clinical presentation of heart failure is the activation of the renin-angiotensin-aldosterone system (RAAS). Normally, RAAS is responsible for the homeostatic regulation of blood pressure, extracellular fluid volume, and serum sodium concentration. In HFrEF, RAAS gets chronically activated in response to decreased cardiac output, further aggravating the congestion and cardiotoxic effects. Hence, inhibition of RAAS is a major approach in the pharmacologic treatment of those patients. The most recently introduced RAAS antagonizing medication class is angiotensin receptor blocker/ neprilysin inhibitor (ARNI). In this paper, we discuss ARNIs' superiority over traditional RAAS antagonizing agents in reducing heart failure hospitalization and mortality. We also tease out the evidence that shows ARNIs' renoprotective functions in heart failure patients including those with chronic or end stage kidney disease. We also discuss the evidence showing the added benefit resulting from combining ARNIs with a sodium-glucose cotransporter-2 (SGLT-2) inhibitor. Moreover, how ARNIs decrease the risk of arrhythmias and reverse cardiac remodeling, ultimately lowering the risk of cardiovascular death, is also discussed. We then present the positive outcome of ARNIs' use in patients with diabetes mellitus and those recovering from acute decompensated heart failure. ARNIs' side effects are also appreciated and discussed. Taken together, the provided insight and critical appraisal of the evidence justifies and supports the implementation of ARNIs in the guidelines for the treatment of HFrEF.

Fragment-based drug design of novel inhibitors targeting lipoprotein (a) kringle domain KIV-10-mediated cardiovascular disease

Cardiovascular diseases (CVDs) are the leading cause of death globally, attributed to a complex etiology involving metabolic, genetic, and protein-related factors. Lipoprotein(a) (Lp(a)), identified as a genetic risk factor, exhibits elevated levels linked to an increased risk of cardiovascular diseases. The lipoprotein(a) kringle domains have recently been identified as a potential target for the treatment of CVDs, in this study we utilized a fragment-based drug design approach to design a novel, potent, and safe inhibitor for lipoprotein(a) kringle domain. With the use of fragment library (61,600 fragments) screening, combined with analyses such as MM/GBSA, molecular dynamics simulation (MD), and principal component analysis, we successfully identified molecules effective against the kringle domains of Lipoprotein(a). The hybridization process (Breed) of the best fragments generated a novel 249 hybrid molecules, among them 77 exhibiting superior binding affinity (≤ -7 kcal/mol) compared to control AZ-02 (-6.9 kcal/mol), Importantly, the top ten molecules displayed high similarity to the control AZ-02. Among the top ten molecules, BR1 exhibited the best docking energy (-11.85 kcal/mol ), and higher stability within the protein LBS site, demonstrating the capability to counteract the pathophysiological effects of lipoprotein(a) [Lp(a)]. Additionally, principal component analysis (PCA) highlighted a similar trend of motion during the binding of BR1 and the control compound (AZ-02), limiting protein mobility and reducing conformational space. Moreover, ADMET analysis indicated favorable drug-like properties, with BR1 showing minimal violations of Lipinski's rules. Overall, the identified compounds hold promise as potential therapeutics, addressing a critical need in cardiovascular medicine. Further preclinical and clinical evaluations are needed to validate their efficacy and safety, potentially ushering in a new era of targeted therapies for CVDs.

Mitochondrial KATP channel-mediated autophagy contributes to angiotensin II-induced vascular dysfunction in mice

BACKGROUND AND AIM

The present study aimed to investigate whether the mitochondrial KATP channel contributes to angiotensin II (Ang II)-induced vascular dysfunction, the development of hypertension, and atherosclerosis.

METHODS AND RESULTS

ApoE (-/-) mice fed a high-fat diet were chronically infused with Ang II for eight weeks and concomitantly treated with losartan (ARB), apocynin, or 5-hydroxy decanoate (5-HD), or 3-methyladenine (3-MA). Systolic blood pressure was measured, and pathological changes of aortic or liver tissue were observed. Nitric oxide (NO), superoxide dismutase 2 (SOD2) levels and vasorelaxation rate were measured, and protein and mRNA expressions were examined by western blot and RT-PCR. Ang II-induced development of hypertension was suppressed not only by ARB, and apocynin but also by 5-HD or 3-MA. Ang II infusion decreased aortic NO production and relaxation, as well as SOD2 activity in liver, which were improved by all treatments. In addition, Ang II-induced activation of autophagy was suppressed by 5-HD in aortic tissue, furthermore, Ang II increases the atherosclerotic index in plasma and exacerbates the development of atherosclerosis by increases of fat deposition in the aorta and liver. Lipid metabolism-related mRNA expressions (LXR-α, LDLR, SRBI, Acca, and FASN) were changed by Ang II. Similarly, not only ARB, and apocynin, but also 5-HD and 3-MA suppressed Ang II-induced these changes.

CONCLUSIONS

Our present findings evidence that mitochondrial KATP channel-mediated autophagy contributes to Ang II-induced vascular dysfunction, development of hypertension, and atherosclerosis.

HIV-Associated Hypertension: Risks, Mechanisms, and Knowledge Gaps

HIV type 1 (HIV-1) is the causative agent of AIDS. Since the start of the epidemic, HIV/AIDS has been responsible for ≈40 million deaths. Additionally, an estimated 39 million people are currently infected with the virus. HIV-1 primarily infects immune cells, such as CD4+ (cluster of differentiation 4+) T lymphocytes (T cells), and as a consequence, the number of CD4+ T cells progressively declines in people living with HIV. Within a span of ≈10 years, HIV-1 infection leads to the systemic failure of the immune system and progression to AIDS. Fortunately, potent antiviral therapy effectively controls HIV-1 infection and prevents AIDS-related deaths. The efficacy of the current antiviral therapy regimens has transformed the outcome of HIV/AIDS from a death sentence to a chronic disease with a prolonged lifespan of people living with HIV. However, antiviral therapy is not curative, is challenged by virus resistance, can be toxic, and, most importantly, requires lifelong adherence. Furthermore, the improved lifespan has resulted in an increased incidence of non-AIDS-related morbidities in people living with HIV including cardiovascular diseases, renal disease, liver disease, bone disease, cancer, and neurological conditions. In this review, we summarize the current state of knowledge of the cardiovascular comorbidities associated with HIV-1 infection, with a particular focus on hypertension. We also discuss the potential mechanisms known to drive HIV-1-associated hypertension and the knowledge gaps in our understanding of this comorbid condition. Finally, we suggest several directions of future research to better understand the factors, pathways, and mechanisms underlying HIV-1-associated hypertension in the post-antiviral therapy era.