Immunity and Hypertension

Renal macrophages induce hypertension and kidney fibrosis in Angiotensin II salt mice model

The immune system is involved in hypertension development with different immune cells reported to have either pro or anti-hypertensive effects. In hypertension, immune cells have been thought to infiltrate blood pressure-regulating organs, resulting in either elevation or reduction of blood pressure. There is controversy over whether macrophages play a detrimental or beneficial role in the development of hypertension, and the few existing studies have yielded conflicting results. This study aimed to determine the effects of angiotensin II (Ang II) salt-induced hypertension on renal immune cells and to determine whether renal macrophages are involved in the induction of hypertension. Hypertension was induced by administration of Ang II and saline for two weeks. The effects of hypertension on kidney immune cells were assessed using flow cytometry. Macrophage infiltration in the kidney was assessed by immunohistochemistry and kidney fibrosis was assessed using trichrome stain and kidney real time-qPCR. Liposome encapsulated clodronate was used to deplete macrophages in C57BL/6J mice and investigate the direct role of macrophages in hypertension induction. Ang II saline mice group developed hypertension, had increased renal macrophages, and had increased expression of Acta2 and Col1a1 and kidney fibrotic areas. Macrophage depletion blunted hypertension development and reduced the expression of Acta2 and Col1a1 in the kidney and kidney fibrotic areas in Ang II saline group. The results of this study demonstrate that macrophages infiltrate the kidneys and increase kidney fibrosis in Ang II salt-induced hypertension, and depletion of macrophages suppresses the development of hypertension and decreases kidney fibrosis. This indicates that macrophages play a direct role in hypertension development. Hence macrophages have a potential to be considered as therapeutic target in hypertension management.

Egg white hydrolysate protects white adipose tissue against metabolic insult in deoxycorticosterone acetate-salt rats

The purpose of this study was to investigate the effect of an egg white hydrolysate (EWH) to protect white adipose tissue damage from cardiometabolic changes induced by severe hypertension. Male Wistar rats were uninephrectomised and divided: SHAM (weekly subcutaneous vehicle (mineral oil + propylene glycol, 1:1)), SHAM + EWH (subcutaneous vehicle plus EWH via gavage, 1 g/kg per day), DOCA (deoxycorticosterone acetate diluted in vehicle subcutaneously weekly in subsequent doses of 20 mg/kg -1st week, 12 mg/kg - 2–3th week, and 6 mg/kg -4–8th week, respectively, plus 1 % NaCl and 0·2 % KCl in drinking water), and DOCA + EWH. Body weight gain, food and water intake, glucose and lipid metabolism were evaluated. Oxidative stress was assessed by biochemical assay and immunofluorescence for NOX-1, nuclear factor kappa B (NFκB), and caspase-3 in retroperitoneal white adipose tissue (rtWAT). Proinflammatory cytokines (IL-6 and 1β), CD163+ macrophage infiltration, and immunohistochemistry for TNFα and uncoupling protein-1 were evaluated, as well as histological analysis on rtWAT. Glutathione peroxidase and reductase were also determined in plasma. EWH showed hypocholesterolemic, antioxidant, anti-inflammatory, and anti-apoptotic properties in the arterial hypertension DOCA-salt model. The results demonstrated the presence of functional changes in adipose tissue function by a decrease in macrophage infiltration and in the fluorescence intensity of NFκB, NOX-1, and caspase-3. A reduction of proinflammatory cytokines and restoration of antioxidant enzymatic activity and mitochondrial oxidative damage by reducing uncoupling protein-1 fluorescence intensity were also observed. EWH could be used as a potential alternative therapeutic strategy in the treatment of cardiometabolic complications associated with malignant secondary arterial hypertension.

Resolution of inflammation, an active process to restore the immune microenvironment balance: A novel drug target for treating arterial hypertension

The resolution of inflammation, the other side of the inflammatory response, is defined as an active and highly coordinated process that promotes the restoration of immune microenvironment balance and tissue repair. Inflammation resolution involves several key processes, including dampening proinflammatory signaling, specialized proresolving lipid mediator (SPM) production, nonlipid proresolving mediator production, efferocytosis and regulatory T-cell (Treg) induction. In recent years, increasing attention has been given to the effects of inflammation resolution on hypertension. Furthermore, our previous studies reported the antihypertensive effects of SPMs. Therefore, in this review, we aim to summarize and discuss the detailed association between arterial hypertension and inflammation resolution. Additional, the association between gut microbe-mediated immune and hypertension is discussed. This findings suggested that accelerating the resolution of inflammation can have beneficial effects on hypertension and its related organ damage. Exploring novel drug targets by focusing on various pathways involved in accelerating inflammation resolution will contribute to the treatment and control of hypertensive diseases in the future.

Microalgae-made human vaccines and therapeutics: A decade of advances

Microalgal emergence is a promising platform with two-decade historical background for producing vaccines and biopharmaceuticals. During that period, microalgal-based vaccines have reported successful production for various diseases. Thus, species selection is important for genetic transformation and delivery methods that have been developed. Although many vaccine prototypes have been produced for infectious and non-infectious diseases, fewer studies have reached immunological and immunoprotective evaluations. Microalgae-made vaccines for Staphylococcus aureus, malaria, influenza, human papilloma, and Zika viruses have been explored in their capacity to induce humoral or cellular immune responses and protective efficacies against experimental challenges. Therefore, specific pathogen antigens and immune system role are important and addressed in controlling these infections. Regarding non-communicable diseases, these vaccines have been investigated for breast cancer; microalgal-produced therapeutic molecules and microalgal-made interferon-α have been explored for hypertension and potential applications in treating viral infections and cancer, respectively. Thus, conducting immunological trials is emphasized, discussing the promising results observed in terms of immunogenicity, desired immune response for controlling affections, and challenges for achieving the desired protection levels. The potential advantages and hurdles associated with this innovative approach are highlighted, underlining the relevance of assessing immune responses in preclinical and clinical trials to validate the efficacy of these biopharmaceuticals. The promising future of this healthcare technology is also envisaged.

Histone deacetylase inhibition by suberoylanilide hydroxamic acid during reperfusion promotes multifaceted brain and vascular protection in spontaneously hypertensive rats with transient ischaemic stroke

Hypertension is the most prevalent modifiable risk factor for stroke and is associated with worse functional outcomes. Pharmacological inhibition of histone deacetylases by suberoylanilide hydroxamic acid (SAHA) modulates gene expression and has emerged as a promising therapeutic approach to reduce ischaemic brain injury. Here, we have tested the therapeutic potential of SAHA administered during reperfusion in adult male spontaneously hypertensive (SHR) rats subjected to transient middle cerebral artery occlusion (tMCAO; 90 min occlusion/24 h reperfusion). Animals received a single dose of SAHA (50 mg/kg) or vehicle i.p. at 1, 4, or 6 h after reperfusion onset. The time-course of brain histone H3 acetylation was studied. After tMCAO, drug brain penetrance and beneficial effects on behavioural outcomes, infarct volume, oedema, angiogenesis, blood-brain barrier integrity, cerebral artery oxidative stress and remodelling, and brain and vascular inflammation were evaluated. SAHA increased brain histone H3 acetylation from 1 to 6 h after injection, reaching the ischaemic brain administered during reperfusion. Treatment given at 4 h after reperfusion onset improved neurological score, reduced infarct volume and oedema, attenuated microglial activation, prevented exacerbated MCA angiogenic sprouting and blood-brain barrier breakdown, normalised MCA oxidative stress and remodelling, and modulated brain and cerebrovascular cytokine expression. Overall, we demonstrate that SAHA administered during early reperfusion exerts robust brain and vascular protection after tMCAO in hypertensive rats. These findings are aligned with previous research in ischaemic normotensive mice and help pave the way to optimise the design of clinical trials assessing the effectiveness and safety of SAHA in ischaemic stroke.

Protective effect of microbiota-derived short chain fatty acids on vascular dysfunction in mice with systemic lupus erythematosus induced by toll like receptor 7 activation

Our objective was to investigate whether short-chain fatty acids (SCFAs), specifically acetate and butyrate, could prevent vascular dysfunction and elevated blood pressure (BP) in mice with systemic lupus erythematosus (SLE) induced by TLR7 activation using imiquimod (IMQ). Treatment with both SCFAs and dietary fibers rich in resistant starch (RS) or inulin-type fructans (ITF) effectively prevented the development of hypertension and cardiac hypertrophy. Additionally, these treatments improved aortic relaxation induced by acetylcholine and mitigated vascular oxidative stress. Acetate and butyrate treatments also contributed to the maintenance of colonic integrity, reduced endotoxemia, and decreased the proportion of helper T (Th)17 cells in mesenteric lymph nodes (MLNs), blood, and aorta in TLR7-induced SLE mice. The observed changes in MLNs were correlated with increased levels of GPR43 mRNA in mice treated with acetate and increased GPR41 levels along with decreased histone deacetylase (HDAC)- 3 levels in mice treated with butyrate. Notably, the effects attributed to acetate, but not butyrate, were nullified when co-administered with the GPR43 antagonist GLPG-0974. T cell priming and differentiation into Th17 cells in MLNs, as well as increased Th17 cell infiltration, were linked to aortic endothelial dysfunction and hypertension subsequent to the transfer of faecal microbiota from IMQ-treated mice to germ-free (GF) mice. These effects were counteracted in GF mice through treatment with either acetate or butyrate. To conclude, these findings underscore the potential of SCFA consumption in averting hypertension by restoring balance to the interplay between the gut, immune system, and vascular wall in SLE induced by TLR7 activation.

A new immune disease: systemic hypertension

Systemic hypertension is the most common medical comorbidity affecting the adult population globally, with multiple associated outcomes including cerebrovascular diseases, cardiovascular diseases, vascular calcification, chronic kidney disease, metabolic syndrome and mortality. Despite advancements in the therapeutic field approximately one in every five adult patients with hypertension is classified as having treatment-resistant hypertension, indicating the need for studies to provide better understanding of the underlying pathophysiology and the need for more therapeutic targets. Recent pre-clinical studies have demonstrated the role of the innate and adaptive immune system including various cell types and cytokines in the pathophysiology of hypertension. Moreover, pre-clinical studies have indicated the potential beneficial effects of immunosuppressant medications in the control of hypertension. Nevertheless, it is unclear whether such pathophysiological mechanisms and therapeutic alternatives are applicable to human subjects, while this area of research is undoubtedly a rapidly growing field.

Unraveling mechanistic insights into the role of microbiome in neurogenic hypertension: A comprehensive review

Neurogenic hypertension, a complex and multifactorial cardiovascular disorder, is known to be influenced by various genetic, environmental, and lifestyle factors. In recent years, there has been growing interest in the role of the gut microbiome in hypertension pathogenesis. The bidirectional communication between the gut microbiota and the central nervous system, known as the microbiota-gut-brain axis, has emerged as a crucial mechanism through which the gut microbiota exerts its influence on neuroinflammation, immune responses, and blood pressure regulation. Recent studies have shown how the microbiome has a substantial impact on a variety of physiological functions, such as cardiovascular health. The increased sympathetic activity to the gut may cause microbial dysbiosis, increased permeability of the gut, and increased inflammatory reactions by altering a number of intestinal bacteria producing short-chain fatty acids (SCFAs) and the concentrations of lipopolysaccharide (LPS) in the plasma. Collectively, these microbial metabolic and structural compounds stimulate sympathetic stimulation, which may be an important stage in the onset of hypertension. The result is an upsurge in peripheral and central inflammatory response. In addition, it has recently been shown that a link between the immune system and the gut microbiota might play a significant role in hypertension. The therapeutic implications of the gut microbiome including probiotic usage, prebiotics, dietary modifications, and fecal microbiota transplantation in neurogenic hypertension have also been found. A large body of research suggests that probiotic supplementation might help reduce chronic inflammation and hypertension that have an association with dysbiosis in the gut microbiota. Overall, this review sheds light on the intricate interplay between the gut microbiome and neurogenic hypertension, providing valuable insights for both researchers and clinicians. As our knowledge of the microbiome's role in hypertension expands, novel therapeutic strategies and diagnostic biomarkers may pave the way for more effective management and prevention of this prevalent cardiovascular disorder. Exploring the potential of the microbiome in hypertension offers an exciting avenue for future research and offers opportunities for precision medicine and improved patient care.

Predictive value of estimated pulse wave velocity with all-cause and cause-specific mortality in the hypertensive population: the National Health and Nutrition Examination Surveys 1999-2014

BACKGROUND

Estimated pulse wave velocity (ePWV) has been proposed as a potential approach to assess carotid-femoral pulse wave velocity (cfPWV). However, the potential ability of ePWV to predict all-cause and cause-specific mortality in the population group with hypertension remains unresolved.

METHODS

We conducted a prospective cohort study using the data of 14 044 adults (age ≥18 years) from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2014, and followed this cohort until the end of December 2019. ePWV was calculated by using a regression equation for age and mean blood pressure (MBP), derived by the Arterial Stiffness Collaborative Group.

RESULTS

The weighted mean age of the 14 044 adults included was 54.79 years; 49.42% of all participants were men. During the median follow-up period of 11 years, 3795 deaths were recorded. In the fully adjusted cox regression model, each 1 m/s increase in ePWV was associated with an increased risk of 56% [hazard ratio 1.61; 95% confidence interval (CI) 1.49-1.64] risk for all-cause mortality. Every 1 m/s increase in ePWV resulted in an increased risk of mortality from cardiovascular disease, cerebrovascular disease, respiratory disease, Alzheimer's disease, accidents, cancer, influenza and pneumonia by 60, 70, 47, 118, 73, 41 and 103%, respectively. ePWV has a robust predictive value for 5- and 10-year all-cause mortality in the hypertensive population with AUCs of 0.749 and 0.741, respectively.

CONCLUSION

Elevated ePWV is positively correlated with all-cause mortality and most cause-specific mortalities, independent of traditional risk factors. Moreover, ePWV demonstrates high accuracy in predicting 5-year and 10-year all-cause mortality, outperforming Framingham Risk Score.

Hypoxia-inducible factors and essential hypertension: narrative review of experimental and clinical data

Hypoxia-inducible factor (HIFs) is a new class of drug developed for the management of anemia in chronic kidney disease (CKD) patients. HIFs increase the production of erythropoietin in the kidney and liver, enhance the absorption and utilization of iron, and stimulate the maturation and proliferation of erythroid progenitor cells. Besides, HIFs regulate many physiologic processes by orchestrating the transcription of hundreds of genes. Essential hypertension (HT) is an epidemic worldwide. HIFs play a role in many biological processes involved in the regulation of blood pressure (BP). In the current review, we summarize pre-clinical and clinical studies investigating the relationship between HIFs and BP regulation in patients with CKD, conflicting issues, and discuss future potential strategies.

Inflammatory markers in patients with hypertension

Hypertension is a chronic disease with high levels of morbidity and disability. Elevated blood pressure can lead to many complications and is the main risk factor for stroke, heart failure and nephropathy. Factors associated with hypertension and inflammatory response differ from those associated with vascular inflammation. The immune system plays a vital role in the pathophysiology of hypertension. Inflammation is particularly relevant in the progression of cardiovascular diseases, which has led to extensive research on inflammatory markers and indicators.

Signaling pathways in vascular function and hypertension: molecular mechanisms and therapeutic interventions

Hypertension is a global public health issue and the leading cause of premature death in humans. Despite more than a century of research, hypertension remains difficult to cure due to its complex mechanisms involving multiple interactive factors and our limited understanding of it. Hypertension is a condition that is named after its clinical features. Vascular function is a factor that affects blood pressure directly, and it is a main strategy for clinically controlling BP to regulate constriction/relaxation function of blood vessels. Vascular elasticity, caliber, and reactivity are all characteristic indicators reflecting vascular function. Blood vessels are composed of three distinct layers, out of which the endothelial cells in intima and the smooth muscle cells in media are the main performers of vascular function. The alterations in signaling pathways in these cells are the key molecular mechanisms underlying vascular dysfunction and hypertension development. In this manuscript, we will comprehensively review the signaling pathways involved in vascular function regulation and hypertension progression, including calcium pathway, NO-NOsGC-cGMP pathway, various vascular remodeling pathways and some important upstream pathways such as renin-angiotensin-aldosterone system, oxidative stress-related signaling pathway, immunity/inflammation pathway, etc. Meanwhile, we will also summarize the treatment methods of hypertension that targets vascular function regulation and discuss the possibility of these signaling pathways being applied to clinical work.

Regulatory mechanism of immune-related genes in patients with hypertension

Hypertension (HT) is among the most common cardiovascular diseases in the world and is an important risk factor for stroke, myocardial infarction, heart failure, and kidney failure. Recent studies have demonstrated that activation of the immune system plays an important role in the occurrence and maintenance of HT. Thus, this research aimed to determine the immune-related biomarkers in HT. In this study, RNA sequencing data of the gene expression profiling datasets (GSE74144) were downloaded from the Gene Expression Omnibus database. Differentially expressed genes between HT and normal samples were identified using the software limma. The immune-related genes associated with HT were screened. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed using the program "clusterProfiler" of the R package. The protein-protein interaction network of these differentially expressed immune-related genes (DEIRGs) was constructed based on the information from the STRING database. Finally, the TF-hub and miRNA-hub gene regulatory networks were predicted and constructed using the miRNet software. Fifty-nine DEIRGs were observed in HT. The Gene Ontology analysis indicated that DEIRGs were mainly enriched in the positive regulation of cytosolic calcium ions, peptide hormones, protein kinase B signaling, and lymphocyte differentiation. The Kyoto Encyclopedia of Genes and Genomes enrichment analysis indicated that these DEIRGs were significantly involved in the intestinal immune network for IgA production, autoimmune thyroid disease, JAK-STAT signaling pathway, hepatocellular carcinoma, and Kaposi sarcoma-associated herpesvirus infection, among others. From the protein-protein interaction network, 5 hub genes (insulin-like growth factor 2, cytokine-inducible Src homology 2-containing protein, suppressor of cytokine signaling 1, cyclin-dependent kinase inhibitor 2A, and epidermal growth factor receptor) were identified. The receiver operating characteristic curve analysis was performed in GSE74144, and all genes with an area under the curve of > 0.7 were identified as the diagnostic genes. Moreover, miRNA-mRNA and TF-mRNA regulatory networks were constructed. Our study identified 5 immune-related hub genes in patients with HT and demonstrated that they were potential diagnostic biomarkers for HT.

Untargeted Metabolomics Analysis Using UHPLC-Q-TOF/MS Reveals Metabolic Changes Associated with Hypertension in Children

The mechanism of hypertension in children remains elusive. The objective of this study was to analyze plasma metabolomics characteristics to explore the potential mechanism of hypertension in children. Serum samples from 29 control children, 38 children with normal body mass index and simple hypertension (NBp), 8 children overweight with simple hypertension (OBp), 37 children with normal body mass index and H-type hypertension (NH) and 19 children overweight with H-type hypertension (OH) were analyzed by non-targeted metabolomics. A total of 1235 differential metabolites were identified between children with hypertension and normal controls, of which 193 metabolites including various lipids were significantly expressed. Compared with the control group, 3-dehydroepiandrosterone sulfate, oleic acid and linoleic acid were up-regulated, and gamma-muricholic acid was down-regulated in the NBp group; 3-dehydroepiandrosterone sulfate, 4-acetamidobutanoate and 1-hexadecanoyl-2-octadecadienoyl-sn-glyero-3-phosphocholine were up-regulated in the OBp group, whereas adenosine and 1-myristoyl-sn-glyero-3-phosphocholine were down-regulated; in the NH group, 1-palmitoyl-2-linoleoyl-sn-glycero-3-phosphocholine, phenol and 3-methoxytyramine were up-regulated, while pentadecanoic acid was down-regulated; in the OH group, NG,NG-dimethyl-L-arginine, 1-palmitoyl-sn-glycero-3-phosphocholine and monoethyl phthalate were up-regulated, while phloretin and glycine were down-regulated. The results showed that the children with hypertension had obvious disorders of lipid metabolism (especially in the overweight hypertension group), which led to the occurrence of hypertension. Additionally, the concentration of NO production-related NG, NG-dimethyl-L-arginine, was significantly increased, which may play an important role in H-type hypertension in children.

Exploring mechanisms of blood pressure regulation in response to device-guided and non-device-guided slow breathing: A mini review

BACKGROUND

Hypertension is a widespread disease that, if persistent, increases the risks of coronary heart disease mortality and morbidity. Slow breathing is a recommended blood pressure-lowering strategy though the mechanisms mediating its effects are unknown.

OBJECTIVE

This review aims to evaluate autonomic and vascular function as potential mediators driving BP adaptive responses with slow breathing.

METHODS

We searched EBSCO host, Web of Science, Cochrane Central Register of Controlled Trials, and PubMed using key words for optimized search results.

RESULTS

Nineteen studies were included in this review (11 device-guided; 8 non-device-guided breathing). Though some studies showed increased vagally mediated components of heart rate variability during slow breathing, results from acute and long-term studies were incongruent. Increases in baroreflex sensitivity (BRS) following a single device-guided slow breathing bout were noted in normotensive and hypertensive adults. Long-term (4 weeks to 3 months) effects of slow breathing on BRS were absent. Device-guided breathing resulted in immediate reductions in muscle sympathetic nerve activity (MSNA) in normo- and hyper-tensive adults though results from long-term studies yielded inconsistent findings. Non-device-guided slow breathing posed acute and chronic effects on vascular function with reductions in arterial stiffness in adults with type I diabetes and increases in microvascular endothelial function in adults with irritable bowel syndrome. Non-device guided breathing also reduced pro-inflammatory cytokines in healthy and hypertensive adults in acute and chronic studies. No adverse effects or non-adherence to treatment were noted in these trials.

CONCLUSION

Device-guided slow breathing is a feasible and effective modality in improving BRS, HRV, and arterial stiffness though its long-term effects are obscure. Though less evidence exists supporting the efficacy of non-device-guided slow breathing, acute and chronic studies demonstrate improvements in vascular function and inflammatory cytokines. More studies are needed to further explore the long-term effects of slow breathing in general and non-device-guided breathing in particular.

The relationship between the pan-immune-inflammation value and long-term prognoses in patients with hypertension: National Health and Nutrition Examination Study, 1999-2018

Background

Direct antihypertensive therapy in hypertensive patients with a high CVD risk can reduce the incidence of cardiovascular death but increase adverse cardiovascular events, so additional ways to identify hypertensive patients at high risk may be needed. Studies have shown that immunity and inflammation affect the prognoses of patients with hypertension and that the pan-immune-inflammation value (PIV) is an index to assess immunity and inflammation, but few studies have applied the PIV index to patients with hypertension.

Objective

To explore the relationship between the PIV and long-term all-cause and cardiovascular mortality in patients with hypertension.

Method

Data from the National Health and Nutrition Examination Survey (NHANES) 1999-2018 with a mortality follow-up through December 31, 2019, were analyzed. A total of 26,781 participants were evaluated. The patients were grouped based on PIV levels as follows: T1 group (n = 8,938), T2 group (n = 8,893), and T3 group (n = 8,950). The relationship between the PIV and long-term all-cause and cardiovascular death was assessed by survival curves and Cox regression analysis based on the NHANES recommended weights.

Result

The PIV was significantly associated with long-term all-cause and cardiovascular mortality in patients with hypertension. After full adjustment, patients with higher PIV have a higher risk of all-cause [Group 3: HR: 1.37, 95% CI: 1.20-1.55, p < 0.001] and cardiovascular [Group 3: HR: 1.62, 95% CI: 1.22-2.15, p < 0.001] mortality.

Conclusion

Elevated PIV was associated with increased all-cause mortality and cardiovascular mortality in hypertensive patients.

The Potential Importance of CXCL1 in the Physiological State and in Noncancer Diseases of the Cardiovascular System, Respiratory System and Skin

In this paper, we present a literature review of the role of CXC motif chemokine ligand 1 (CXCL1) in physiology, and in selected major non-cancer diseases of the cardiovascular system, respiratory system and skin. CXCL1, a cytokine belonging to the CXC sub-family of chemokines with CXC motif chemokine receptor 2 (CXCR2) as its main receptor, causes the migration and infiltration of neutrophils to the sites of high expression. This implicates CXCL1 in many adverse conditions associated with inflammation and the accumulation of neutrophils. The aim of this study was to describe the significance of CXCL1 in selected diseases of the cardiovascular system (atherosclerosis, atrial fibrillation, chronic ischemic heart disease, hypertension, sepsis including sepsis-associated encephalopathy and sepsis-associated acute kidney injury), the respiratory system (asthma, chronic obstructive pulmonary disease (COPD), chronic rhinosinusitis, coronavirus disease 2019 (COVID-19), influenza, lung transplantation and ischemic-reperfusion injury and tuberculosis) and the skin (wound healing, psoriasis, sunburn and xeroderma pigmentosum). Additionally, the significance of CXCL1 is described in vascular physiology, such as the effects of CXCL1 on angiogenesis and arteriogenesis.

Intestinal microbiota: A promising therapeutic target for hypertension

Hypertension has developed into an escalating serious global public health problem with multiple and unclear pathophysiological mechanisms. Recent studies have identified intestinal microbiota as a key perpetrator of hypertension through a variety of mechanisms. In this review, we highlight the potential roles of the intestinal microbiota and its metabolites in the development of hypertension, as well as the therapeutic potential for targeting intestinal microbiomes. We also shed light on the main limitations and challenges of the current research and suggest directions for future investigations. Finally, we discuss the development of accurate and personalized preventive and therapeutic strategies for hypotension by the modulation of intestinal microbes and metabolites.

Intradialytic hypotension prediction using covariance matrix-driven whale optimizer with orthogonal structure-assisted extreme learning machine

Intradialytic hypotension (IDH) is an adverse event occurred during hemodialysis (HD) sessions with high morbidity and mortality. The key to preventing IDH is predicting its pre-dialysis and administering a proper ultrafiltration prescription. For this purpose, this paper builds a prediction model (bCOWOA-KELM) to predict IDH using indices of blood routine tests. In the study, the orthogonal learning mechanism is applied to the first half of the WOA to improve the search speed and accuracy. The covariance matrix is applied to the second half of the WOA to enhance the ability to get out of local optimum and convergence accuracy. Combining the above two improvement methods, this paper proposes a novel improvement variant (COWOA) for the first time. More, the core of bCOWOA-KELM is that the binary COWOA is utilized to improve the performance of the KELM. In order to verify the comprehensive performance of the study, the paper sets four types of comparison experiments for COWOA based on 30 benchmark functions and a series of prediction experiments for bCOWOA-KELM based on six public datasets and the HD dataset. Finally, the results of the experiments are analyzed separately in this paper. The results of the comparison experiments prove fully that the COWOA is superior to other famous methods. More importantly, the bCOWOA performs better than its peers in feature selection and its accuracy is 92.41%. In addition, bCOWOA improves the accuracy by 0.32% over the second-ranked bSCA and by 3.63% over the worst-ranked bGWO. Therefore, the proposed model can be used for IDH prediction with future applications.

Ketamine Regulates the Autophagy Flux and Polarization of Microglia through the HMGB1-RAGE Axis and Exerts Antidepressant Effects in Mice

Depression is a leading cause of disability worldwide. Here, we explored the role of the HMGB1-RAGE pathway in lipopolysaccharide (LPS)-induced depression-like behavior and microglial autophagy flux, neuroinflammation, and polarization in a mouse model. Male C57BL/6 mice were infused with LPS in the abdominal cavity to induce a depression model. They then underwent testing to assess behavior and cognition. Real-time fluorescent quantitative polymerase chain reaction was used to detect the expression of the M1/M2 microglia polarization markers, HMGB1, and RAGE. Microglial activation and phenotypic transformation in the hippocampus were identified. mRFP-GFP-LC3 and Western blotting were used to detect autophagy flux in each treatment group. Finally, an LPS-induced BV2 cell model was developed to verify the involvement of the HMGB1-RAGE pathway, autophagy flux, and polarization. Ketamine improved LPS-induced depression-like behavior, inhibited the LPS-induced upregulation of HMGB1 and RAGE and the nuclear translocation of HMGB1. Moreover, ketamine reversed the blocked autophagy flux of microglia caused by LPS and regulated microglial autophagy flux through the HMGB1-RAGE pathway and microglial polarization. These results suggest that ketamine may reduce HMGB1 and RAGE accumulation in patients with depression, thereby providing a new therapeutic target for preventing and treating this disease.

Systemic immune-inflammation index (SII) may be an effective indicator in predicting the left ventricular hypertrophy for patients diagnosed with hypertension

The development of left ventricular hypertrophy (LVH) induced by hypertension is considered a poor prognosis for patients. Similarly, high values of the systemic immune-inflammation index (SII) are correlated with high mortality and morbidity in cardiovascular events. Within this context, our study aimed to detect the association of SII with LVH caused by hypertension. The study included 150 patients diagnosed with hypertension in total and evaluated them as two separate groups with regard to left ventricular mass index (LVMI), including 56 patients (37.3%) with LVH and 94 patients (62.6%) with non-LVH. SII was calculated as platelet × neutrophil/lymphocyte counts. The SII values regarding the group with LVH were detected remarkably higher than those of the non-LVH group (p < 0.001). Additionally, the SII levels of patients with eccentric and concentric hypertrophy were detected higher than those of the normal ventricular geometry and concentric remodeling groups. About curve analysis of the receiver-operating characteristic (ROC), SII values above 869.5 predicted LVH with a sensitivity of 82.1% and specificity of 86.2% (AUC: 0.861; 95% CI: 0.792-0.930; p < 0.001). LVH can be predicted independently through the use of SII in patients diagnosed with hypertension, which may be a simple and easily calculable marker for judging LVH. Moreover, SII can serve as an accurate determinant for the prediction of LVH, in comparison to NLR and PLR.

Inflammatory cytokines are associated to lower glomerular filtration rate in patients with hypertensive crisis

Introduction

Hypertension and kidney function are closely related. However, there are few studies on renal function during acute elevation of blood pressure (BP), denominated hypertensive crisis (HC).

Objectives

To evaluate the relationship between renal function and inflammatory cytokines in HC, subdivided into hypertensive urgency (HUrg) and emergency (HEmerg).

Materials and methods

This cross-sectional study was carried out in 74 normotensive (NT) and 74 controlled hypertensive individuals (ContrHT) followed up in outpatient care. Additionally, 78 subjects with hypertensive emergency (HEmerg) and 50 in hypertensive urgency (HUrg), attended in emergency room, were also evaluated. Hypertensive crisis was classified into HEmerg, defined by systolic blood pressure (BP) ≥ 180 mmHg and/or diastolic BP ≥ 120 mmHg in presence of target-organ damage (TOD), and HypUrg, clinical situation with BP elevation without TOD. The glomerular filtration rate (eGFR) was estimated, and cytokine levels were measured. Statistical analysis was performed using the Kruskal-Wallis or Mann-Whitney test and Spearman’s correlation, with significant differences p-value &lt; 0.05.

Results

The median age was 53.5 years in the NT group (52 female), 61 years in the ContrHT group (52 female), and 62.5 years in the HC group (63 female) (p-value &lt; 0.0001). The median BP was 118.5/75 mmHg for NT, 113.5/71 for ContrHT, and 198.5/120 mmHg for HC, respectively (p-value &lt; 0.0001 among groups). BP and heart rate levels were significantly higher in the HC group compared to the NT and ContrHT groups (P &lt; 0.001 for all). The eGFR was significantly lower in HC group compared to the NT and ContrHT groups. The cytokine levels were higher in the HEmerg and HUrg groups compared to ContrHT group (P &lt; 0.0001, except for IL-1β in HUrg vs. ContrHT), without difference between the acute elevation of BP groups. Thus, all cytokines were significantly elevated in patients with HC compared to the control groups (NT and ContrHT). There was a negative correlation between eGFR and the cytokines (IL-1β, IL-6, IL-8, IL-10, and TNF-α) in the HC group.

Conclusion

Elevated inflammatory cytokines are associated with reduced eGFR in individuals with HC compared to control groups, suggesting that the inflammatory process participates in the pathogenesis of acute elevations of BP.

Transcriptomic Profiling Reveals Underlying Immunoregulation Mechanisms of Resistant Hypertension in Injection Drug Users

Background

Hypertension is a common complication in injection drug users (IDU), especially a high proportion of resistant hypertension occurs among them. However, the involving mechanisms remain largely unknown.

Methods

We here investigated the key signaling moieties in resistant hypertension in drug users. Analyses were performed with high-throughput transcriptomic sequencing data of peripheral blood from individuals with drug-sensitive hypertension (Ctrl-DS), IDU with resistant hypertension (IDU-DR), and IDU with sensitive hypertension (IDU-DS).

Results

We showed that 17 and 1 genes in IDU-DS, 48 and 4 genes in IDU-DR were upregulated and downregulated compared Ctrl-DS, and 2 and 4 genes were upregulated and downregulated in IDU-DR compared with IDU-DS, respectively (p ≤ 0.01 and |log₂(FC)| ≥ 1). Differentially expressed genes (DEGs) between Ctrl-DS and IDU-DS were mainly involved in Gene ontology terms of immunoglobulin complex and blood microparticle. DEGs between IDU-DS and IDU-DR were mainly involved in immune system process and immunoglobulin complex. DEGs between Ctrl-DS and IDU-DR were mainly involved in immunoglobulin complex, blood microparticle and cytoplasmic vesicle lumen. We identified 2 gene clusters (brown modules, MEbrown; turquoise module, MEturquoise) correlated with IDU-DR and a gene cluster (magenta module, MEmagenta) correlated with IDU-DS by weighted gene co-expression network analysis (WGCNA). Functional analysis demonstrated that pathways of focal adhesion and focalin-1-rich granule lumen were involved in the development of IDU-DR, and the cytosolic large ribosomal subunit may relate to IDU-DR. Further, immune cell infiltration analysis demonstrated that the abundance of dendritic cells (DCs), natural Treg cells (nTreg), and exhausted T cells (Tex) in IDU-DR and IDU-DS, naïve CD8⁺ T cells in IDU-DS was significantly different compared with that in Ctrl-DS. The abundance of cytotoxic T cells (Tc) was significantly different between IDU-DS and IDU-DR.

Conclusion

Our findings indicated a potential function of immunoregulation mechanisms for resistant hypertension.

Immune system changes in those with hypertension when infected with SARS-CoV-2

The coronavirus disease 2019 (COVID-19) outbreak has become an evolving global health crisis. With an increasing incidence of primary hypertension, there is greater awareness of the relationship between primary hypertension and the immune system [including CD4+, CD8+ T cells, interleukin-17 (IL-17)/T regulatory cells (Treg) balance, macrophages, natural killer (NK) cells, neutrophils, B cells, and cytokines]. Hypertension is associated with an increased risk of various infections, post-infection complications, and increased mortality from severe infections. Despite ongoing reports on the epidemiological and clinical features of COVID-19, no articles have systematically addressed the role of primary hypertension in COVID-19 or how COVID-19 affects hypertension or specific treatment in these high-risk groups. Here, we synthesize recent advances in understanding the relationship between primary hypertension and COVID-19 and its underlying mechanisms and provide specific treatment guidelines for these high-risk groups.

[Interleukin-17A is closely correlated with the progression of renal epithelial-mesenchymal transition in spontaneously hypertensive rats]

OBJECTIVE

To explore the role of interleukin-17A (IL-17A) in renal epithelial- mesenchymal transition (EMT) in essential hypertensive nephropathy.

METHODS

Four-week-old spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats (control group) were both randomized into 4 groups (n=5) for observation at 4, 6, 10 and 30 weeks of age. Blood pressure of the rats was monitored using a noninvasive tail artery blood pressure measurement instrument. The percentage of Th17 cells in the splenocytes was analyzed using flow cytometry. The mRNA and protein expression levels of IL-17A, iNOS, Arg-1, E-cadherin, and α-SMA in the kidneys of the rats were detected using RT-PCR and immunohistochemical staining, respectively, and plasma levels of IL-17A were regularly detected using ELISA.

RESULTS

At the age of 6 weeks, the SHRs began to show significantly higher blood pressure with greater Th17 cell percentage in the splenocytes and high renal expression and plasma level of IL-17A than WKY rats (P < 0.05 or P < 0.01). At 30 weeks, renal expression of E-cadherin mRNA and protein was significantly lower and the expression of Arg-1 mRNA and protein was significantly higher in SHR than in WKY rats (P < 0.01). Compared with the WKY rats, the SHRs showed significantly higher mRNA and protein expressions of iNOS at 6 and 10 weeks (P < 0.05 or 0.01) and higher α-SMA mRNA and protein expressions since 10 weeks of age (P < 0.05 or 0.01). In SHRs older than 10 weeks, renal IL-17A mRNA and protein expression levels were negatively correlated with those of E-cadherin (r=-0.731, P < 0.05; r=-0.827, P < 0.01) and positively correlated with those of α-SMA (r=0.658, P < 0.05; r=0.968, P < 0.01).

CONCLUSION

IL-17A is closely correlated with the progression of renal EMT in SHR and plays its role possibly by mediating M1/M2 polarization of renal infiltrating macrophages.

Chronic Limb Remote Ischemic Conditioning may have an Antihypertensive Effect in Patients with Hypertension

Hypertension is the leading preventable risk factor for all-cause morbidity and mortality worldwide. Despite antihypertensive medications have been available for decades, a big challenge we are facing is to increase the blood pressure (BP) control rate among the population. Therefore, it is necessary to search for new antihypertensive means to reduce the burden of disease caused by hypertension. Limb remote ischemic conditioning (LRIC) can trigger endogenous protective effects through transient and repeated ischemia on the limb to protect specific organs and tissues including the brain, heart, and kidney. The mechanisms of LRIC involve the regulation of the autonomic nervous system, releasing humoral factors, improvement of vascular endothelial function, and modulation of immune/inflammatory responses. These underlying mechanisms of LRIC may restrain the pathogenesis of hypertension through multiple pathways theoretically, leading to a potential decline in BP. Several existing studies have explored the impact of LRIC on BP, however, controversial findings were reported. To explore the potential antihypertensive effect of LRIC and the underlying mechanisms, we systematically reviewed the relevant articles to provide an insight into the novel therapy of hypertension.

Arterial stiffness in children with primary hypertension is related to subclinical inflammation

Introduction

The immune system can trigger an inflammatory process leading to blood pressure elevation and arterial damage. The aim of the study was to assess the relation between subclinical inflammation and arterial damage in pediatric patients with primary hypertension (PH) and to establish the usefulness of neutrophil-to-lymphocyte (NLR) and platelet-to-lymphocyte (PLR) ratios, and mean platelet volume (MPV) as markers of arterial damage in these subjects.

Material and methods

In 119 children with PH (14.94 ±2.76 years) and 45 healthy children (14.91 ±2.69 years) we analyzed markers of subclinical inflammation (NLR, PLR, MPV), clinical and biochemical parameters, office blood pressure, ambulatory blood pressure monitoring (ABPM), central blood pressure, aortic pulse wave velocity (aPWV), augmentation index corrected for heart rates 75 (AIx75HR), carotid intima media thickness (cIMT), and common carotid artery stiffness (E-tracking).

Results

Children with PH were characterized by significantly higher neutrophil (3.9 ±1.7 vs. 3.0 ±1.0 [1000/µl], p < 0.001) and platelet counts (271.9 ±62.3 vs. 250.3 ±60.3 [1000/µl], p = 0.047), NLR (1.9 ±1.5 vs. 1.3 ±0.4, p = 0.010), PLR (131.4 ±41.9 vs. 114.7 ±37.6, p = 0.020), aPWV (5.36 ±0.88 vs. 4.88 ±0.92 m/s, p = 0.004), and cIMT (0.46 ±0.07 vs. 0.43 ±0.07 mm, p = 0.002) compared to healthy children. In PH children NLR correlated positively (p < 0.05) with: systolic, diastolic and mean blood pressure in ABPM (r = 0.243, r = 0.216, r = 0.251), aPWV [m/s] (r = 0.241), aPWV Z-score (r = 0.204), and common carotid artery PWVbeta [m/s] (r = 0.202).

Conclusions

There is a link between arterial stiffness and subclinical inflammation in pediatric patients with primary hypertension. Neutrophil-to-lymphocyte ratio may serve as a promising marker of arterial stiffness in pediatric patients affected by primary hypertension.

The sympathies of the body: functional organization and neuronal differentiation in the peripheral sympathetic nervous system

During the last 30 years, our understanding of the development and diversification of postganglionic sympathetic neurons has dramatically increased. In parallel, the list of target structures has been critically extended from the cardiovascular system and selected glandular structures to metabolically relevant tissues such as white and brown adipose tissue, lymphoid tissues, bone, and bone marrow. A critical question now emerges for the integration of the diverse sympathetic neuron classes into neural circuits specific for these different target tissues to achieve the homeostatic regulation of the physiological ends affected.

Therapeutic Potential of SphK1 Inhibitors Based on Abnormal Expression of SphK1 in Inflammatory Immune Related-Diseases

Sphingosine kinase 1(SphK1) a key enzyme that catalyzes the conversion of sphingosine (Sph) to sphingosine 1-phosphate (S1P), so as to maintain the dynamic balance of sphingolipid-rheostat in cells and participate in cell growth and death, proliferation and migration, vasoconstriction and remodeling, inflammation and metabolism. The normal expression of SphK1 maintains the balance of physiological and pathological states, which is reflected in the regulation of inflammatory factor secretion, immune response in traditional immune cells and non-traditional immune cells, and complex signal transduction. However, abnormal SphK1 expression and activity are found in various inflammatory and immune related-diseases, such as hypertension, atherosclerosis, Alzheimer’s disease, inflammatory bowel disease and rheumatoid arthritis. In view of the therapeutic potential of regulating SphK1 and its signal, the current research is aimed at SphK1 inhibitors, such as SphK1 selective inhibitors and dual SphK1/2 inhibitor, and other compounds with inhibitory potency. This review explores the regulatory role of over-expressed SphK1 in inflammatory and immune related-diseases, and investigate the latest progress of SphK1 inhibitors and the improvement of disease or pathological state.

Polymodal roles of TRPC3 channel in the kidney

TRPC3 is a Ca²⁺-permeable cation channel commonly activated by the G-protein coupled receptors (GPCR) and mechanical distortion of the plasma membrane. TRPC3-mediated Ca²⁺ influx has been implicated in a variety of signaling processes in both excitable and non-excitable cells. Kidneys play a commanding role in maintaining whole-body homeostasis and setting blood pressure. TRPC3 is expressed abundantly in the renal vasculature and in epithelial cells, where it is well positioned to mediate signaling and transport functions in response to GPCR-dependent endocrine stimuli. In addition, TRPC3 could be activated by mechanical forces resulting from dynamic changes in the renal tubule fluid flow and osmolarity. This review critically analyzes the available published evidence of the physiological roles of TRPC3 in different parts of the kidney and describes the pathophysiological ramifications of TRPC3 ablation. We also speculate how this evidence could be further translated into the clinic.

Mitochondrial tRNA Mutations Associated With Essential Hypertension: From Molecular Genetics to Function

Essential hypertension (EH) is one of the most common cardiovascular diseases worldwide, entailing a high level of morbidity. EH is a multifactorial disease influenced by both genetic and environmental factors, including mitochondrial DNA (mtDNA) genotype. Previous studies identified mtDNA mutations that are associated with maternally inherited hypertension, including tRNA^Ile m.4263A>G, m.4291T>C, m.4295A>G, tRNA^Met m.4435A>G, tRNA^Ala m.5655A>G, and tRNA^Met/tRNA^Gln m.4401A>G, et al. These mtDNA mutations alter tRNA structure, thereby leading to metabolic disorders. Metabolic defects associated with mitochondrial tRNAs affect protein synthesis, cause oxidative phosphorylation defects, reduced ATP synthesis, and increase production of reactive oxygen species. In this review we discuss known mutations of tRNA genes encoded by mtDNA and the potential mechanisms by which these mutations may contribute to hypertension.