Attenuation of Microbiotal Dysbiosis and Hypertension in a CRISPR/Cas9 Gene Ablation Rat Model of GPER1

Gene editing of angiotensin for blood pressure management

Arterial hypertension has remained the world's leading cause of morbidity and mortality for more than 20 years. While early Genome-Wide Association Studies raised the hypothesis that a precision medicine approach could be implemented in the treatment of hypertension, the large number of single nucleotide polymorphisms that were found to be associated with blood pressure and their limited impact on the blood pressure values have initially hampered these expectations. With the development and refinement of gene-editing and RNA-based approaches allowing selective and organ-specific modulation of critical systems involved in blood pressure regulation, a renewed interest in genetic treatments for hypertension has emerged. The CRISPR-Cas9 system, antisense oligonucleotides (ASO) and small interfering RNA (siRNA) have been used to specifically target the hepatic angiotensinogen (AGT) production, with the scope of safely but effectively reducing the activation of the renin-angiotensin system, ultimately leading to an effective reduction of the blood pressure with extremely simplified treatment regimens that involve weekly, monthly or even once-in-life injection of the drugs. Among the various approaches, siRNA and ASO that reduce hepatic AGT production are in advanced development, with phase I and II clinical trials showing their safety and effectiveness. In the current manuscript, we review the mode of action of these new approaches to hypertension treatment, discussing the results of the clinical trials and their potential to revolutionize the management of hypertension.

Perspectives on the involvement of the gut microbiota in salt-sensitive hypertension

Salt-sensitivity hypertension (SSH) is an independent predictor of cardiovascular event-related death. Despite the extensiveness of research on hypertension, which covers areas such as the sympathetic nervous system, the renin-angiotensin system, the vascular system, and the immune system, its pathogenesis remains elusive, with sub-optimal blood pressure control in patients. The gut microbiota is an important component of nutritional support and constitutes a barrier in the host. Long-term high salt intake can lead to gut microbiota dysbiosis and cause significant changes in the expression of gut microbiota-related metabolites. Of these metabolites, short chain fatty acids (SCFAs), trimethylamine oxide, amino acids, bile acids, and lipopolysaccharide are essential mediators of microbe-host crosstalk. These metabolites may contribute to the incidence and development of SSH via inflammatory, immune, vascular, and nervous pathways, among others. In addition, recent studies, including those on the histone deacetylase inhibitory mechanism of SCFAs and the blood pressure-decreasing effects of H2S via vascular activation, suggest that several proteins and factors in the classical pathway elicit their effects through multiple non-classical pathways. This review summarizes changes in the gut microbiota and its related metabolites in high-salt environments, as well as corresponding treatment methods for SSH, such as diet management, probiotic and prebiotic use, antibiotic use, and fecal transplantation, to provide new insights and perspectives for understanding SSH pathogenesis and the development of strategies for its treatment.

Double-side role of short chain fatty acids on host health via the gut-organ axes

Short chain fatty acids (SCFA) exist in dietary foods and are produced by the fermentation of gut microbiota, and are considered an important element for regulating host health. Through blood circulation, SCFA produced in the gut and obtained from foods have an impact on the intestinal health as well as vital organs of the host. It has been recognized that the gut is the "vital organ" in the host. As the gut microbial metabolites, SCFA could create an "axis" connecting the gut and to other organs. Therefore, the "gut-organ axes" have become a focus of research in recent years to analyze organism health. In this review, we summarized the sources, absorption properties, and the function of SCFA in both gut and other peripheral tissues (brain, kidney, liver, lung, bone and cardiovascular) in the way of "gut-organ axes". Short chain fatty acids exert both beneficial and pathological role in gut and other organs in various ways, in which the beneficial effects are more pronounced. In addition, the beneficial effects are reflected in both preventive and therapeutic effects. More importantly, the mechanisms behinds the gut and other tissues provided insight into the function of SCFA, assisting in the development of novel preventive and therapeutic strategies for maintaining the host health.

Salt Sensitivity: Causes, Consequences, and Recent Advances

Salt (sodium chloride) is an essential nutrient required to maintain physiological functions. However, for most people, daily salt intake far exceeds their physiological need and is habitually greater than recommended upper thresholds. Excess salt intake leads to elevation in blood pressure which drives cardiovascular morbidity and mortality. Indeed, excessive salt intake is estimated to be responsible for ≈5 million deaths per year globally. For approximately one-third of otherwise healthy individuals (and >50% of those with hypertension), the effect of salt intake on blood pressure elevation is exaggerated; such people are categorized as salt sensitive and salt sensitivity of blood pressure is considered an independent risk factor for cardiovascular disease and death. The prevalence of salt sensitivity is higher in women than in men and, in both, increases with age. This narrative review considers the foundational concepts of salt sensitivity and the underlying effector systems that cause salt sensitivity. We also consider recent updates in preclinical and clinical research that are revealing new modifying factors that determine the blood pressure response to high salt intake.

Associations of nighttime light exposure during pregnancy with maternal and neonatal gut microbiota: A cohort study

BACKGROUND

Nighttime light (NTL) pollution has been reported as a risk factor for human health. However, the relationship between NTL and gut microbiota has not been reported in pregnant women and neonates. This study was conducted to investigate the relationship between NTL and gut microbial diversity and composition in mothers and their neonates.

METHODS

This study analyzed 44 mothers and 28 newborns. The composition of gut microbiota was evaluated using 16S rRNA V3-V4 sequencing. The monthly mean NTL exposure during pregnancy was respectively calculated based on each participant's residential address (NTLpoint) and a concentric 1 km radius buffer zone around their address (NTL1000m). The relationships between NTL exposure and gut microbiota of mothers and newborns were assessed using generalized linear models.

RESULTS

NTL exposure during pregnancy was not associated with alpha diversity of mothers or neonates. For mothers, results revealed that after adjusting for covariates, NTLpoint was negatively correlated with Prevotella_2 (p = 0.004, FDR-adjusted p = 0.030) and norank_o__Gastranaerophilales (p = 0.018, FDR-adjusted p = 0.049) at the genus level. In addition, Lachnospira (p = 0.036, FDR-adjusted p = 0.052) and Coprococcus_3 (p = 0.025, FDR-adjusted p = 0.052) were positively correlated with NTLpoint. The association between Coprococcus_3 (p = 0.01, FDR-adjusted p = 0.046) and NTLpoint persisted even after controlling for covariates. For neonates, Thauera was positively associated with NTLpoint (p = 0.015) and NTL1000m (p = 0.028), however, after adjusting for covariates and FDR correction, Thauera was not significantly associated with NTLpoint and NTL1000m.

CONCLUSIONS

This study found that NTL exposure was associated with maternal gut microbiota composition. Our findings provide a foundation for the potential impact of NTL exposure on maternal gut microbiota from a microbiological perspective. More population-based validation of the effects of NTL exposure on human gut microbiota is needed in future.

Exploring a novel therapeutic strategy: the interplay between gut microbiota and high-fat diet in the pathogenesis of metabolic disorders

In the past two decades, the rapid increase in the incidence of metabolic diseases, including obesity, diabetes, dyslipidemia, non-alcoholic fatty liver disease, hypertension, and hyperuricemia, has been attributed to high-fat diets (HFD) and decreased physical activity levels. Although the phenotypes and pathologies of these metabolic diseases vary, patients with these diseases exhibit disease-specific alterations in the composition and function of their gut microbiota. Studies in germ-free mice have shown that both HFD and gut microbiota can promote the development of metabolic diseases, and HFD can disrupt the balance of gut microbiota. Therefore, investigating the interaction between gut microbiota and HFD in the pathogenesis of metabolic diseases is crucial for identifying novel therapeutic strategies for these diseases. This review takes HFD as the starting point, providing a detailed analysis of the pivotal role of HFD in the development of metabolic disorders. It comprehensively elucidates the impact of HFD on the balance of intestinal microbiota, analyzes the mechanisms underlying gut microbiota dysbiosis leading to metabolic disruptions, and explores the associated genetic factors. Finally, the potential of targeting the gut microbiota as a means to address metabolic disturbances induced by HFD is discussed. In summary, this review offers theoretical support and proposes new research avenues for investigating the role of nutrition-related factors in the pathogenesis of metabolic disorders in the organism.

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.

G protein-coupled estrogen receptor: a promising therapeutic target for aldosterone-induced hypertension

Aldosterone is one of the most essential hormones synthesized by the adrenal gland because it regulates water and electrolyte balance. G protein-coupled estrogen receptor (GPER) is a newly discovered aldosterone receptor, which is proposed to mediate the non-genomic pathways of aldosterone while the hormone simultaneously interacts with mineralocorticoid receptor. In contrast to its cardio-protective role in postmenopausal women via its interaction with estrogen, GPER seems to trigger vasoconstriction effects and can further induce water and sodium retention in the presence of aldosterone, indicating two entirely different binding sites and effects for estrogen and aldosterone. Accumulating evidence also points to a role of aldosterone in mediating hypertension and its risk factors via the interaction with GPER. Therefore, with this review, we aimed to summarize the research on these interactions to help (1) elucidate the role of GPER activated by aldosterone in the blood vessels, heart, and kidney; (2) compare the non-genomic actions between aldosterone and estrogen mediated by GPER; and (3) address the potential of GPER as a new promising therapeutic target for aldosterone-induced hypertension.

The G protein-coupled oestrogen receptor GPER in health and disease: an update

Oestrogens and their receptors contribute broadly to physiology and diseases. In premenopausal women, endogenous oestrogens protect against cardiovascular, metabolic and neurological diseases and are involved in hormone-sensitive cancers such as breast cancer. Oestrogens and oestrogen mimetics mediate their effects via the cytosolic and nuclear receptors oestrogen receptor-α (ERα) and oestrogen receptor-β (ERβ) and membrane subpopulations as well as the 7-transmembrane G protein-coupled oestrogen receptor (GPER). GPER, which dates back more than 450 million years in evolution, mediates both rapid signalling and transcriptional regulation. Oestrogen mimetics (such as phytooestrogens and xenooestrogens including endocrine disruptors) and licensed drugs such as selective oestrogen receptor modulators (SERMs) and downregulators (SERDs) also modulate oestrogen receptor activity in both health and disease. Following up on our previous Review of 2011, we herein summarize the progress made in the field of GPER research over the past decade. We will review molecular, cellular and pharmacological aspects of GPER signalling and function, its contribution to physiology, health and disease, and the potential of GPER to serve as a therapeutic target and prognostic indicator of numerous diseases. We also discuss the first clinical trial evaluating a GPER-selective drug and the opportunity of repurposing licensed drugs for the targeting of GPER in clinical medicine.

Causality of gut microbiome and hypertension: A bidirectional mendelian randomization study

Background & Aims

The pathogenesis of hypertension involves a diverse range of genetic, environmental, hemodynamic, and more causative factors. Recent evidence points to an association between the gut microbiome and hypertension. Given that the microbiota is in part determined by host genetics, we used the two-sample Mendelian randomization (MR) analysis to address the bidirectional causal link between gut microbiota and hypertension.

Methods

We selected genetic variants (P < 1  ×  10^-5) for gut microbiota (n = 18,340) from the MiBioGen study. Genetic association estimates for hypertension were extracted from genome-wide association study (GWAS) summary statistics on 54,358 cases and 408,652 controls. Seven complementary MR methods were implemented, including the inverse-variance weighted (IVW) method, followed by sensitivity analyses to verify the robustness of the results. Reverse-direction MR analyses were further conducted to probe if there was a reverse causative relationship. Bidirectional MR analysis then examines a modulation of gut microbiota composition by hypertension.

Results

At the genus level, our MR estimates from gut microbiome to hypertension showed that there were 5 protective factors Allisonella, Parabacteroide, Phascolarctobacterium, Senegalimassilia, and unknowngenus (id.1000000073), while 6 genera Clostridiuminnocuum, Eubacteriumcoprostanoligenes, Eubacteriumfissicatena, Anaerostipes, LachnospiraceaeFCS020, and unknowngenus (id.2041) are risk factors. The Alcaligenaceae and ClostridialesvadinBB60 were detrimental and beneficial at the family level, respectively. In contrast, the MR results of hypertension-gut flora showed hypertensive states can lead to an increased abundance of Eubacteriumxylanophilum, Eisenbergiella, and Lachnospiraceae and a lower abundance of Alistipes, Bilophila, Butyricimonas, and Phascolarctobacterium.

Conclusion

Altered gut microbiota is a causal factor in the development of hypertension, and hypertension causes imbalances in the intestinal flora. Substantial research is still needed to find the key gut flora and explore the specific mechanisms of their effects so that new biomarkers can be found for blood pressure control.

CRISPR-Cas for genome editing: Classification, mechanism, designing and applications

Clustered regularly interspersed short pallindromic repeats (CRISPR) and CRISPR associated proteins (Cas) system (CRISPR-Cas) came into light as prokaryotic defence mechanism for adaptive immune response. CRISPR-Cas works by integrating short sequences of the target genome (spacers) into the CRISPR locus. The locus containing spacers interspersed repeats is further expressed into small guide CRISPR RNA (crRNA) which is then deployed by the Cas proteins to evade the target genome. Based on the Cas proteins CRISPR-Cas is classified according to polythetic system of classification. The characteristic of the CRISPR-Cas9 system to target DNA sequences using programmable RNAs has opened new arenas due to which today CRISPR-Cas has evolved as cutting end technique in the field of genome editing. Here, we discuss about the evolution of CRISPR, its classification and various Cas systems including the designing and molecular mechanism of CRISPR-Cas. Applications of CRISPR-Cas as a genome editing tools are also highlighted in the areas such as agriculture, and anticancer therapy. Briefly discuss the role of CRISPR and its Cas systems in the diagnosis of COVID-19 and its possible preventive measures. The challenges in existing CRISP-Cas technologies and their potential solutions are also discussed briefly.

Repurposing a Drug Targeting Inflammatory Bowel Disease for Lowering Hypertension

Background The gut and gut microbiota, which were previously neglected in blood pressure regulation, are becoming increasingly recognized as factors contributing to hypertension. Diseases affecting the gut such as inflammatory bowel disease (IBD) present with aberrant energy metabolism of colonic epithelium and gut dysbiosis, both of which are also mechanisms contributing to hypertension. We reasoned that current measures to remedy deficits in colonic energy metabolism and dysbiosis in IBD could also ameliorate hypertension. Among them, 5-aminosalicylic acid (5-ASA; mesalamine) is a PPARγ (peroxisome proliferator-activated receptor gamma) agonist. It attenuates IBD by a dual mechanism of selectively enhancing colonic epithelial cell energy metabolism and ameliorating gut dysbiosis. Methods and Results A total of 2 groups of 11- to 12-week-old male, hypertensive, Dahl salt-sensitive (S) rats were gavaged with (n=10) or without (n=10) 5-aminosalicylic acid (150 mg/kg) for 4 weeks. Rats receiving 5-aminosalicylic acid treatment had a lower mean blood pressure than controls (145±3 mm Hg versus 153±4 mm Hg; P<0.0001). This reduction in blood pressure was accompanied by increased activity of PPARγ, increased expression of energy metabolism-related genes, and lowering of the Firmicutes/Bacteroidetes ratio in the colon, the reduction of which is a marker for the correction of gut dysbiosis. Furthermore, these data were consistent with the American Gut Project wherein the Firmicutes/Bacteroidetes ratio of non-IBD (n=611) patients was significantly lower than patients with IBD (n=631). Conclusions 5-Aminosalicylic acid could be repurposed for hypertension by specifically enhancing the gut energy metabolism and correction of microbiota dysbiosis.

Six Decades of History of Hypertension Research at the University of Toledo: Highlighting Pioneering Contributions in Biochemistry, Genetics, and Host-Microbiota Interactions

PURPOSE OF REVIEW

The study aims to capture the history and lineage of hypertension researchers from the University of Toledo in Ohio and showcase their collective scientific contributions dating from their initial discoveries of the physiology of adrenal and renal systems and genetics regulating blood pressure (BP) to its more contemporary contributions including microbiota and metabolomic links to BP regulation.

RECENT FINDINGS

The University of Toledo College of Medicine and Life Sciences (UTCOMLS), previously known as the Medical College of Ohio, has contributed significantly to our understanding of the etiology of hypertension. Two of the scientists, Patrick Mulrow and John Rapp from UTCOMLS, have been recognized with the highest honor, the Excellence in Hypertension award from the American Heart Association for their pioneering work on the physiology and genetics of hypertension, respectively. More recently, Bina Joe has continued their legacy in the basic sciences by uncovering previously unknown novel links between microbiota and metabolites to the etiology of hypertension, work that has been recognized by the American Heart Association with multiple awards. On the clinical research front, Christopher Cooper and colleagues lead the CORAL trials and contributed importantly to the investigations on renal artery stenosis treatment paradigms. Hypertension research at this institution has not only provided these pioneering insights, but also grown careers of scientists as leaders in academia as University Presidents and Deans of Medical Schools. Through the last decade, the university has expanded its commitment to Hypertension research as evident through the development of the Center for Hypertension and Precision Medicine led by Bina Joe as its founding Director. Hypertension being the top risk factor for cardiovascular diseases, which is the leading cause of human mortality, is an important area of research in multiple international universities. The UTCOMLS is one such university which, for the last 6 decades, has made significant contributions to our current understanding of hypertension. This review is a synthesis of this rich history. Additionally, it also serves as a collection of audio archives by more recent faculty who are also prominent leaders in the field of hypertension research, including John Rapp, Bina Joe, and Christopher Cooper, which are cataloged at Interviews .

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.

Perinatal Garlic Oil Supplementation Averts Rat Offspring Hypertension Programmed by Maternal Chronic Kidney Disease

Garlic (Allium sativum) is a functional food, having hydrogen sulfide (H₂S)-releasing capacity, which exhibits considerable effects on hypertension and gut microbiota. H₂S is strongly associated with hypertension and chronic kidney disease (CKD). Maternal CKD leads to hypertension in adult rat progeny, which was linked to disruption of the gut microbiota. This study validated the benefits of perinatal garlic oil supplementation against offspring hypertension induced by maternal CKD via modulation of H₂S signaling, nitric oxide (NO), and the gut microbiota. Before pregnancy, female rats received a 0.5% adenine diet for 3 weeks to develop an animal model to mimic human CKD. Garlic oil (100 mg/kg/day) or vehicle was administered to pregnant rats by oral gavage during gestation and lactation. Perinatal garlic oil supplementation protected against maternal CKD-induced hypertension in offspring at 12 weeks of age. The beneficial effects of garlic oil are associated with enhanced H₂S signaling, increased NO bioavailability, and shifts in gut microbiota. Perinatal garlic oil supplementation reduces abundance of genera Variovorax, Nocardia, Sphingomonas, and Rhodococcus. Our findings provide insight into the role of early H₂S-targeted intervention as a preventive strategy in hypertension for further translational research.

Microbiota-derived short-chain fatty acids: Implications for cardiovascular and metabolic disease

Cardiovascular diseases (CVDs) have been on the rise around the globe in the past few decades despite the existing guidelines for prevention and treatment. Short-chain fatty acids (SCFAs) are the main metabolites of certain colonic anaerobic bacterial fermentation in the gastrointestinal tract and have been found to be the key metabolites in the host of CVDs. Accumulating evidence suggest that the end-products of SCFAs (including acetate, propionate, and butyrate) interact with CVDs through maintaining intestinal integrity, anti-inflammation, modulating glucolipid metabolism, blood pressure, and activating gut-brain axis. Recent advances suggest a promising way to prevent and treat CVDs by controlling SCFAs. Hence, this review tends to summarize the functional roles carried out by SCFAs that are reported in CVDs studies. This review also highlights several novel therapeutic interventions for SCFAs to prevent and treat CVDs.

The use of new CRISPR tools in cardiovascular research and medicine

Many novel CRISPR-based genome-editing tools, with a wide variety of applications, have been developed in the past few years. The original CRISPR-Cas9 system was developed as a tool to alter genomic sequences in living organisms in a simple way. However, the functions of new CRISPR tools are not limited to conventional genome editing mediated by non-homologous end-joining or homology-directed repair but expand into gene-expression control, epigenome editing, single-nucleotide editing, RNA editing and live-cell imaging. Furthermore, genetic perturbation screening by multiplexing guide RNAs is gaining popularity as a method to identify causative genes and pathways in an unbiased manner. New CRISPR tools can also be applied to ex vivo or in vivo therapeutic genome editing for the treatment of conditions such as hyperlipidaemia. In this Review, we first provide an overview of the diverse new CRISPR tools that have been developed to date. Second, we summarize how these new CRISPR tools are being used to study biological processes and disease mechanisms in cardiovascular research and medicine. Finally, we discuss the prospect of therapeutic genome editing by CRISPR tools to cure genetic cardiovascular diseases.

The Important Role of TaohongSiwu Decoction in Gut Microbial Modulation in Response to High-Salt Diet-Induced Hypertensive Mice

TaohongSiwu decoction (THSWD), a traditional Chinese recipe, has been widely used to treat hypertension since ancient times. However, the mechanisms of its action are still unclear. Herein, we aimed to explore the gut microbial activity of THSWD in high-salt diet-induced hypertensive mice. Eight percent high-salt (NaCl) diet was used to induce hypertension for 4 weeks in a mouse model. Meanwhile, THSWD was used to intervene in the high-salt diet-induced mice, and the efficacy was evaluated by different parameters. Here, we found that THSWD significantly restored blood pressure compared with the model group. Moreover, THSWD effectively protected endothelial function by significantly upregulating the level of nitric oxide (NO) and downregulating the level of endothelin-1 (ET-1), angiotensin I (AngI), and vascular endothelial growth factor (VEGF) in serum compared with the model group. Notably, THSWD significantly upregulated the relative abundance of Dubosiella and downregulated that of Cyanobium_PCC-6307 and DNF00809 at the genus level compared with the model group. The results of PCA and microbial distance calculation further exhibited that THSWD treatment resulted in significant regulation of the microbial community. Furthermore, compared with the model group, THSWD increased the level of vitamin k2 (VK2) in serum. These findings indicate that THSWD could protect blood pressure and endothelial function by regulating gut microbiota and promoting microbial metabolite VK2. These results show the important role of THSWD in regulating the gut microbiota in response to high-salt diet-induced mice.

Genetic Modifications to Alter Blood Pressure Level

Genetic manipulation is one of the indispensable techniques to examine gene functions both in vitro and in vivo. In particular, cardiovascular phenotypes such as blood pressure cannot be evaluated in vitro system, necessitating the creation of transgenic or gene-targeted knock-out and knock-in experimental animals to understand the pathophysiological roles of specific genes on the disease conditions. Although genome-wide association studies (GWAS) in various human populations have identified multiple genetic variations associated with increased risk for hypertension and/or its complications, the causal links remain unresolved. Genome-editing technologies can be applied to many different types of cells and organisms for creation of knock-out/knock-in models. In the post-GWAS era, it may be more worthwhile to validate pathophysiological implications of the risk variants and/or candidate genes by creating genome-edited organisms.

Current approaches in CRISPR-Cas9 mediated gene editing for biomedical and therapeutic applications

A single gene mutation can cause a number of human diseases that affect quality of life. Until the development of clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein (Cas) systems, it was challenging to correct a gene mutation to avoid disease by reverting phenotypes. The advent of CRISPR technology has changed the field of gene editing, given its simplicity and intrinsic programmability, surpassing the limitations of both zinc-finger nuclease and transcription activator-like effector nuclease and becoming the method of choice for therapeutic gene editing by overcoming the bottlenecks of conventional gene-editing techniques. Currently, there is no commercially available medicinal cure to correct a gene mutation that corrects and reverses the abnormality of a gene's function. Devising reprogramming strategies for faithful recapitulation of normal phenotypes is a crucial aspect for directing the reprogrammed cells toward clinical trials. The CRISPR-Cas9 system has been promising as a tool for correcting gene mutations in maladies including blood disorders and muscular degeneration as well as neurological, cardiovascular, renal, genetic, stem cell, and optical diseases. In this review, we highlight recent developments and utilization of the CRISPR-Cas9 system in correcting or generating gene mutations to create model organisms to develop deeper insights into diseases, rescue normal gene functionality, and curb the progression of a disease.

CRISPR Gene Editing in Lipid Disorders and Atherosclerosis: Mechanisms and Opportunities

Elevated circulating concentrations of low-density lipoprotein cholesterol (LDL-C) have been conclusively demonstrated in epidemiological and intervention studies to be causally associated with the development of atherosclerotic cardiovascular disease. Enormous advances in LDL-C reduction have been achieved through the use of statins, and in recent years, through drugs targeting proprotein convertase subtilisin/kexin type 9 (PCSK9), a key regulator of the hepatic LDL-receptor. Existing approaches to PCSK9 targeting have used monoclonal antibodies or RNA interference. Although these approaches do not require daily dosing, as statins do, repeated subcutaneous injections are nevertheless necessary to maintain effectiveness over time. Recent experimental studies suggest that clustered regularly interspaced short palindromic repeats (CRISPR) gene-editing targeted at PCSK9 may represent a promising tool to achieve the elusive goal of a 'fire and forget' lifelong approach to LDL-C reduction. This paper will provide an overview of CRISPR technology, with a particular focus on recent studies with relevance to its potential use in atherosclerotic cardiovascular disease.

Vaccination of Gilthead Seabream After Continuous Xenoestrogen Oral Exposure Enhances the Gut Endobolome and Immune Status via GPER1

In fish culture settings, the exogenous input of steroids is a matter of concern. Recently, we unveiled that in the gilthead seabream (Sparus aurata), the G protein-coupled estrogen receptor agonist G-1 (G1) and the endocrine disruptor 17α-ethinylestradiol (EE₂) are potent modulators in polyreactive antibody production. However, the integral role of the microbiota upon immunity and antibody processing in response to the effect of EE₂ remains largely unexplored. Here, juvenile seabreams continuously exposed for 84 days to oral G1 or EE₂ mixed in the fish food were intraperitoneally (i.p.) immune primed on day 42 with the model antigen keyhole limpet hemocyanin (KLH). A critical panel of systemic and mucosal immune markers, serum VTG, and humoral, enzymatic, and bacteriolytic activities were recorded and correlated with gut bacterial metagenomic analysis 1 day post-priming (dpp). Besides, at 15 dpp, animals received a boost to investigate the possible generation of specific anti-KLH antibodies at the systemic and mucosal interphases by the end of the trial. On day 43, EE₂ but not G1 induced a significant shift in the serum VTG level of naive fish. Simultaneously, significant changes in some immune enzymatic activities in the serum and gut mucus of the EE₂-treated group were recorded. In comparison, the vaccine priming immunization resulted in an attenuated profile of most enzymatic activities in the same group. The gut genes qPCR analysis exhibited a related pattern, only emphasized by a significant shift in the EE₂ group's il1b expression. The gut bacterial microbiome status underwent 16S rRNA dynamic changes in alpha diversity indices, only with the exposure to oral G1, supporting functional alterations on cellular processes, signaling, and lipid metabolism in the microbiota. By the same token, the immunization elevated the relative abundance of Fusobacteria only in the control group, while this phylum was depleted in both the treated groups. Remarkably, the immunization also promoted changes in the bacterial class Betaproteobacteria and the estrogen-associated genus Novosphingobium. Furthermore, systemic and mucosal KLH-specific immunoglobulin (Ig)M and IgT levels in the fully vaccinated fish showed only slight changes 84 days post-estrogenic oral administration. In summary, our results highlight the intrinsic relationship among estrogens, their associated receptors, and immunization in the ubiquitous fish immune regulation and the subtle but significant crosstalk with the gut endobolome.

Common Metabolites in Two Different Hypertensive Mouse Models: A Serum and Urine Metabolome Study

Recent metabolomics studies have identified a wide array of microbial metabolites and metabolite pathways that are significantly altered in hypertension. However, whether these metabolites play an active role in pathogenesis of hypertension or are altered because of this has yet to be determined. In the current study, we hypothesized that metabolite changes common between hypertension models may unify hypertension's pathophysiology with respect to metabolites. We utilized two common mouse models of experimental hypertension: L-arginine methyl ester hydrochloride (L-NAME)/high-salt-diet-induced hypertension (LSHTN) and angiotensin II induced hypertension (AHTN). To identify common metabolites that were altered across both models, we performed untargeted global metabolomics analysis in serum and urine and the resulting data were analyzed using MetaboAnalyst software and compared to control mice. A total of 41 serum metabolites were identified as being significantly altered in any hypertensive model compared to the controls. Of these compounds, 14 were commonly changed in both hypertensive groups, with 4 significantly increased and 10 significantly decreased. In the urine, six metabolites were significantly altered in any hypertensive group with respect to the control; however, none of them were common between the hypertensive groups. These findings demonstrate that a modest, but potentially important, number of serum metabolites are commonly altered between experimental hypertension models. Further studies of the newly identified metabolites from this untargeted metabolomics analysis may lead to a greater understanding of the association between gut dysbiosis and hypertension.

Low-Density Lipoprotein Receptor-Related Protein 5-Deficient Rats Have Reduced Bone Mass and Abnormal Development of the Retinal Vasculature

Humans carrying homozygous loss-of-function mutations in the Wnt co-receptor, low-density lipoprotein receptor-related protein 5 (LRP5), develop osteoporosis and a defective retinal vasculature known as familial exudative vitreoretinopathy (FEVR) due to disruption of the Wnt signaling pathway. The purpose of this study was to use CRISPR-Cas9-mediated gene editing to create strains of Lrp5-deficient rats and to determine whether knockout of Lrp5 resulted in phenotypes that model the bone and retina pathology in LRP5-deficient humans. Knockout of Lrp5 in rats produced low bone mass, decreased bone mineral density, and decreased bone size. The superficial retinal vasculature of Lrp5-deficient rats was sparse and disorganized, with extensive exudates and decreases in vascularized area, vessel length, and branch point density. This study showed that Lrp5 could be predictably knocked out in rats using CRISPR-Cas9, causing the expression of bone and retinal phenotypes that will be useful for studying the role of Wnt signaling in bone and retina development and for research on the treatment of osteoporosis and FEVR.

Gut Microbial Metabolites and Blood Pressure Regulation: Focus on SCFAs and TMAO

Shifts in the gut microbiome play a key role in blood pressure regulation, and changes in the production of gut microbial metabolites are likely to be a key mechanism. Known gut microbial metabolites include short-chain fatty acids, which can signal via G-protein-coupled receptors, and trimethylamine-N oxide. In this review, we provide an overview of gut microbial metabolites documented thus far to play a role in blood pressure regulation.

CRISPR/Cas9 Mediated Deletion of the Angiotensinogen Gene Reduces Hypertension: A Potential for Cure?

[Figure: see text].

Integrated bioinformatics analysis reveals novel key biomarkers and potential candidate small molecule drugs in gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is the metabolic disorder that appears during pregnancy. The current investigation aimed to identify central differentially expressed genes (DEGs) in GDM. The transcription profiling by array data (E-MTAB-6418) was obtained from the ArrayExpress database. The DEGs between GDM samples and non-GDM samples were analyzed. Functional enrichment analysis were performed using ToppGene. Then we constructed the protein–protein interaction (PPI) network of DEGs by the Search Tool for the Retrieval of Interacting Genes database (STRING) and module analysis was performed. Subsequently, we constructed the miRNA–hub gene network and TF–hub gene regulatory network. The validation of hub genes was performed through receiver operating characteristic curve (ROC). Finally, the candidate small molecules as potential drugs to treat GDM were predicted by using molecular docking. Through transcription profiling by array data, a total of 869 DEGs were detected including 439 up-regulated and 430 down-regulated genes. Functional enrichment analysis showed these DEGs were mainly enriched in reproduction, cell adhesion, cell surface interactions at the vascular wall and extracellular matrix organization. Ten genes, HSP90AA1, EGFR, RPS13, RBX1, PAK1, FYN, ABL1, SMAD3, STAT3 and PRKCA were associated with GDM, according to ROC analysis. Finally, the most significant small molecules were predicted based on molecular docking. This investigation identified hub genes, signal pathways and therapeutic agents, which might help us, enhance our understanding of the mechanisms of GDM and find some novel therapeutic agents for GDM.

The Role and Mechanism of Intestinal Flora in Blood Pressure Regulation and Hypertension Development

Significance: Hypertension (HTN) has a complex etiology that is characterized by genetic and environmental factors. It has become a global health burden leading to cardiovascular diseases and kidney diseases, ultimately progressing to premature death. Accumulating evidence indicated that gut microbiome was associated with metabolic disorders and inflammation, which were closely linked to HTN. Recent Advances: Recent studies using bacterial genomic analysis and fecal microbiota transplantation as well as many lines of seminal evidence demonstrated that aberrant gut microbiome was significantly associated with HTN. The intestinal microbiome of both patients and animals with HTN had decreased bacterial diversity, disordered microbial structure and functions, and altered end products of fermentation. Gut dysbiosis and metabolites of the gut microbiota play an important role in blood pressure (BP) control, and they are therefore responsible for developing HTN. Critical Issues: This study aimed at focusing on the recent advances in understanding the role played by gut bacteria and the mechanisms underlying the pathological milieu that induced elevated BP and led to HTN pathogenesis. Potential intervention strategies targeting the correction of gut dysbiosis to improve HTN development were summarized. Future Directions: Larger numbers of fecal transplants from participants with HTN should be carried out to examine the magnitude of BP changes with the replacement of the gut microbiome. The proposed mechanisms for the gut in regulating BP remain to be verified. Whether intervention strategies using probiotics, dietary interventions, bacteriophages, and fecal transplants are feasible for individuals with HTN remains to be explored. Antioxid. Redox Signal. 34, 811-830.

Genome editing in cardiovascular diseases

Genetic modification at the molecular level in somatic cells, germline, and animal models requires for different purposes, such as introducing desired mutation, deletion of alleles, and insertion of novel genes in the genome. Various genome-editing tools are available to accomplish these alterations, such as zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR associated (Cas) system. CRISPR-Cas system is an emerging technology, which is being used in biological and medical sciences, including in the cardiovascular field. It assists to identify the mechanism of various cardiovascular disease occurrence, such as hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), and arrhythmogenic cardiomyopathy (ACM). Furthermore, it has been advantages to edit various genes simultaneously and can also be used to treat and prevent several human diseases. This chapter explores the use of the scientific and therapeutic potential of a CRISPR-Cas system to edit the various cardiovascular disease-associated genes to understand the pathways involved in disease progression and treatment.

Aldosterone-induced hypertension is sex-dependent, mediated by T cells and sensitive to GPER activation

AIMS

The G protein-coupled estrogen receptor 1 (GPER) may modulate some effects of aldosterone. In addition, G-1 (a GPER agonist) can lower blood pressure (BP) and promote T cell-mediated anti-inflammatory responses. This study aimed to test the effects of G-1 and G-15 (a GPER antagonist) on aldosterone-induced hypertension in mice and to examine the cellular mechanisms involved.

METHODS AND RESULTS

C57Bl/6 (wild-type, WT), RAG1-deficient and GPER-deficient mice were infused with vehicle, aldosterone (0.72 mg/kg/day S.C. plus 0.9% NaCl for drinking) ± G-1 (0.03 mg/kg/day S.C.) ± G-15 (0.3 mg/kg/day S.C.) for 14 days. G-1 attenuated aldosterone-induced hypertension in male WT but not male GPER-deficient mice. G-15 alone did not alter hypertension but it prevented the anti-hypertensive effect of G-1. In intact female WT mice, aldosterone-induced hypertension was markedly delayed and suppressed compared with responses in males, with BP remaining unchanged until after Day 7. In contrast, co-administration of aldosterone and G-15 fully increased BP within 7 days in WT females. Similarly, aldosterone robustly increased BP by Day 7 in ovariectomized WT females, and in both sexes of GPER-deficient mice. Whereas aldosterone had virtually no effect on BP in RAG1-deficient mice, adoptive transfer of T cells from male WT or male GPER-deficient mice into male RAG1-deficient mice restored the pressor response to aldosterone. This pressor effect could be attenuated by G-1 in RAG1-deficient mice that were reconstituted with either WT or GPER-deficient T cells, suggesting that G-1 does not act via T cells to lower BP.

CONCLUSION

Our findings indicate that although aldosterone-induced hypertension is largely mediated by T cells, it can be attenuated by activation of GPER on non-T cells, which accounts for the sex difference in sensitivity to the pressor effect.

Targeting Gut Microbiota to Treat Hypertension: A Systematic Review

While hypertension remains the leading modifiable risk factor for cardiovascular morbidity and mortality, the pathogenesis of essential hypertension remains only partially understood. Recently, microbial dysbiosis has been associated with multiple chronic diseases closely related to hypertension. In addition, multiple small-scale animal and human studies have provided promising results for the association between gut microbial dysbiosis and hypertension. Animal models and a small human pilot study, have demonstrated that high salt intake, a risk factor for both hypertension and cardiovascular disease, depletes certain Lactobacillus species while oral treatment of Lactobacilli prevented salt-sensitive hypertension. To date, four large cohort studies have reported modest associations between gut microbiota features and hypertension. In this systematic literature review, we examine the previously reported links between the gut microbiota and hypertension and what is known about the functional mechanisms behind this association.

Effects of a human-based mixture of persistent organic pollutants on the in vivo exposed cerebellum and cerebellar neuronal cultures exposed in vitro

Exposure to persistent organic pollutants (POPs), encompassing chlorinated (Cl), brominated (Br) and perfluoroalkyl acid (PFAA) compounds is associated with adverse neurobehaviour in humans and animals, and is observed to cause adverse effects in nerve cell cultures. Most studies focus on single POPs, whereas studies on effects of complex mixtures are limited. We examined the effects of a mixture of 29 persistent compounds (Cl + Br + PFAA, named Total mixture), as well as 6 sub-mixtures on in vitro exposed rat cerebellar granule neurons (CGNs). Protein expression studies of cerebella from in vivo exposed mice offspring were also conducted. The selection of chemicals for the POP mixture was based on compounds being prominent in food, breast milk or blood from the Scandinavian human population. The Total mixture and sub-mixtures containing PFAAs caused greater toxicity in rat CGNs than the single or combined Cl/Br sub-mixtures, with significant impact on viability from 500x human blood levels. The potencies for these mixtures based on LC₅₀ values were Br + PFAA mixture > Total mixture > Cl + PFAA mixture > PFAA mixture. These mixtures also accelerated induced lipid peroxidation. Protection by the competitive N-methyl-D-aspartate (NMDA) receptor antagonist 3-((R)-2-Carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP) indicated involvement of the NMDA receptor in PFAA and Total mixture-, but not Cl mixture-induced toxicity. Gene-expression studies in rat CGNs using a sub-toxic and marginally toxic concentration ((0.4 nM-5.5 µM) 333x and (1 nM-8.2 µM) 500x human blood levels) of the mixtures, revealed differential expression of genes involved in apoptosis, oxidative stress, neurotransmission and cerebellar development, with more genes affected at the marginally toxic concentration. The two important neurodevelopmental markers Pax6 and Grin2b were downregulated at 500x human blood levels, accompanied by decreases in PAX6 and GluN2B protein levels, in cerebellum of offspring mice from mothers exposed to the Total mixture throughout pregnancy and lactation. In rat CGNs, the glutathione peroxidase gene Prdx6 and the regulatory transmembrane glycoprotein gene Sirpa were highly upregulated at both concentrations. In conclusion, our results support that early-life exposure to mixtures of POPs can cause adverse neurodevelopmental effects.

Gut Microbiota-Related Evidence Provides New Insights Into the Association Between Activating Transcription Factor 4 and Development of Salt-Induced Hypertension in Mice

Activating transcription factor 4 (ATF4), which regulates genes associated with endoplasmic reticulum stress, apoptosis, autophagy, the gut microbiome, and metabolism, has been implicated in many diseases. However, its mechanistic role in hypertension remains unclear. In the present study, we investigated its role in salt-sensitive hypertensive mice. Wild-type (WT) C57BL/6J mice were used to establish Atf4 knockout (KO) and overexpression mice using CRISPR-Cas9 and lentiviral overexpression vectors. Then, fecal microbiota transplantation (FMT) from Atf4 ^± mice and vitamin K₂ (VK2) supplementation were separately carried out in high-salt-diet (8% NaCl)-induced mice for 4 weeks. We found that Atf4 KO inhibited and Atf4 overexpression enhanced the increase in blood pressure and endothelial dysfunction induced by high salt intake in mice, while regulating the gut microbiota composition and VK2 expression. It was further verified that ATF4 is involved in the regulation of salt-sensitive hypertension and vascular endothelial function, which is achieved through association with gut microbiota and may be related to VK2 and different bacteria such as Dubosiella. In addition, we found that VK2 supplementation prevents the development of salt-sensitive hypertension and maintains vascular endothelial function; moreover, VK2 supplementation increases the abundance of intestinal Dubosiella and downregulates the relative expression of Atf4 in the thoracic aorta of mice. We conclude that ATF4 plays an important role in regulating gut microbiota and VK2 production, providing new insights into the association between ATF4 and development of salt-induced hypertension in mice, meanwhile contributing to the development for a new preventive strategy of hypertension.

MiR-155-Mediated Deregulation of GPER1 Plays an Important Role in the Gender Differences Related to Inflammatory Bowel Disease

Aim

The incidence and clinical manifestations of inflammatory bowel disease (IBD) are thought to have gender differences, which suggests that the estrogen signaling pathway and intestinal flora may play key roles in the pathogenesis of IBD. In IBD, microRNA-155 (miR-155) is upregulated and regulates G protein coupled estrogen receptor (GPER1), which affects the intestinal flora. The objective of this study was to investigate the role of the estrogen receptors and miR-155 in the pathogenesis of IBD.

Methods

From July 2018 to July 2019, in the Department of Gastroenterology at Daping Hospital, Army Military Medical University, a total of 50 patients with IBD were included in this study, and 24 healthy examinees were randomly selected as the control group. Colonoscopies were performed, and clinical characteristics and blood samples were collected from all of the subjects. The serum cytokine levels in the patients with IBD and the health donors were detected by ELISA, and the estrogen receptor level measurements for all of the participants were assessed by immunohistochemistry (IHC) and quantitative real-time PCR (qPCR). The miR-155 levels were detected by qPCR in all of the participants, and miR-155^−/− mice were used to investigate the mechanism of miR-155 in the pathogenesis of IBD.

Results

The clinical characteristics and medications were different for the IBD patients when gender was considered. The male patients produced more proinflammatory cytokines, and while GPER1 expression was downregulated, miR-155 was upregulated in the patients with IBD. MiR-155 showed proinflammatory activity, while GPER1 showed an anti-inflammatory response during the pathogenesis of IBD. The miR-155^−/− mice showed improvements in weight loss, survival, rectal bleeding, colon length, and histopathological changes compared with the wild-type mice. Furthermore, the male miR-155^−/− mice showed increased inflammation compared to the female miR-155^−/− mice in the above aspects.

Conclusion

This study presents evidence indicating that miR-155 plays a key role in the pathogenesis of IBD for the different genders. MiR-155 was upregulated and showed proinflammatory activity, whereas GPER1 showed an anti-inflammatory response during the pathogenesis of IBD. The results demonstrated that more proinflammatory cytokines and reduced GPER1 levels were observed in the male IBD patients. Thus, miR-155 was involved in the regulation of GPER1 and induced gender differences in IBD patients. MiR-155 may be a potential marker for IBD-targeted therapy.

Gut microbiota-derived short-chain fatty acids and hypertension: Mechanism and treatment

Hypertension (HTN) is an growing emerging health issue around across the world. In recent years, increasing attention has been paid to the role of dysbacteriosis in HTN and its underlying mechanism. Short-chain fatty acids (SCFAs), which are novel metabolites of intestinal flora, exert substantial regulatory effects on HTN, providing an exciting avenue for novel therapies for this disease. They function primarily by activating transmembrane G protein-coupled receptors and inhibiting histone acetylation. In this review, we discuss the mechanisms underlying the complex interaction between SCFAs and gut microbiota composition to lower blood pressure by regulating the brain-gut and kidney-gut axes, and the role of high-salt diet, immune system, oxidative stress, and inflammatory mechanism in the development of HTN. Furthermore, we also discuss the various treatment strategies for HTN, including diet, antibiotics, probiotics, fecal microflora transplantation, and traditional Chinese medicine. In conclusion, manipulation of SCFAs opens new avenues to improve treatment of HTN.

Rat models of human diseases and related phenotypes: a systematic inventory of the causative genes

The laboratory rat has been used for a long time as the model of choice in several biomedical disciplines. Numerous inbred strains have been isolated, displaying a wide range of phenotypes and providing many models of human traits and diseases. Rat genome mapping and genomics was considerably developed in the last decades. The availability of these resources has stimulated numerous studies aimed at discovering causal disease genes by positional identification. Numerous rat genes have now been identified that underlie monogenic or complex diseases and remarkably, these results have been translated to the human in a significant proportion of cases, leading to the identification of novel human disease susceptibility genes, helping in studying the mechanisms underlying the pathological abnormalities and also suggesting new therapeutic approaches. In addition, reverse genetic tools have been developed. Several genome-editing methods were introduced to generate targeted mutations in genes the function of which could be clarified in this manner [generally these are knockout mutations]. Furthermore, even when the human gene causing a disease had been identified without resorting to a rat model, mutated rat strains (in particular KO strains) were created to analyze the gene function and the disease pathogenesis. Today, over 350 rat genes have been identified as underlying diseases or playing a key role in critical biological processes that are altered in diseases, thereby providing a rich resource of disease models. This article is an update of the progress made in this research and provides the reader with an inventory of these disease genes, a significant number of which have similar effects in rat and humans.

Diurnal Timing Dependent Alterations in Gut Microbial Composition Are Synchronously Linked to Salt-Sensitive Hypertension and Renal Damage

Alterations of diurnal rhythms of blood pressure (BP) and reshaping of gut microbiota are both independently associated with hypertension. However, the relationships between biorhythms of BP and gut microbial composition are unknown. We hypothesized that diurnal timing-associated alterations of microbial compositions are synchronous with diurnal rhythmicity, dip in BP, and renal function. To test this hypothesis, Dahl salt-sensitive (S) rats on low- and high-salt diets were examined for time of day effects on gut microbiota, BP, and indicators of renal damage. Major shifts in night and day patterns of specific groups of microbiota were observed between the dark (active) and light (rest) phases, which correlated with diurnal rhythmicity of BP. The diurnal abundance of Firmicutes, Bacteroidetes, and Actinobacteria were independently associated with BP. Discrete bacterial taxa were observed to correlate independently or interactively with one or more of the following 3 factors: (1) BP rhythm, (2) dietary salt, and (3) dip in BP. Phylogenetic Investigation of Communities revealed diurnal timing effects on microbial pathways, characterized by upregulated biosynthetic processes during the active phase of host, and upregulated degradation pathways of metabolites in the resting phase. Additional metagenomics functional pathways with rhythm variations were noted for aromatic amino acid metabolism and taurine metabolism. These diurnal timing dependent changes in microbiota, their functional pathways, and BP dip were associated with concerted effects of the levels of renal lipocalin 2 and kidney injury molecule-1 expression. These data provide evidence for a firm and concerted diurnal timing effects of BP, renal damage, and select microbial communities.

The gut microbiota and its interactions with cardiovascular disease

The intestine is colonized by a considerable community of microorganisms that cohabits within the host and plays a critical role in maintaining host homeostasis. Recently, accumulating evidence has revealed that the gut microbial ecology plays a pivotal role in the occurrence and development of cardiovascular disease (CVD). Moreover, the effects of imbalances in microbe-host interactions on homeostasis can lead to the progression of CVD. Alterations in the composition of gut flora and disruptions in gut microbial metabolism are implicated in the pathogenesis of CVD. Furthermore, the gut microbiota functions like an endocrine organ that produces bioactive metabolites, including trimethylamine/trimethylamine N-oxide, short-chain fatty acids and bile acids, which are also involved in host health and disease via numerous pathways. Thus, the gut microbiota and its metabolic pathways have attracted growing attention as a therapeutic target for CVD treatment. The fundamental purpose of this review was to summarize recent studies that have illustrated the complex interactions between the gut microbiota, their metabolites and the development of common CVD, as well as the effects of gut dysbiosis on CVD risk factors. Moreover, we systematically discuss the normal physiology of gut microbiota and potential therapeutic strategies targeting gut microbiota to prevent and treat CVD.

Microbiota are critical for vascular physiology: Germ-free status weakens contractility and induces sex-specific vascular remodeling in mice

Commensal microbiota within a holobiont contribute to the overall health of the host via mutualistic symbiosis. Disturbances in such symbiosis is prominently correlated with a variety of diseases affecting the modern society of humans including cardiovascular diseases, which are the number one contributors to human mortality. Given that a hallmark of all cardiovascular diseases is changes in vascular function, we hypothesized that depleting microbiota from a holobiont would induce vascular dysfunction. To test this hypothesis, young mice of both sexes raised in germ-free conditions were examined vascular contractility and structure. Here we observed that male and female germ-free mice presented a decrease in contraction of resistance arteries. These changes were more pronounced in germ-free males than in germ-free females mice. Furthermore, there was a distinct change in vascular remodeling between males and females germ-free mice. Resistance arteries from male germ-free mice demonstrated increased vascular stiffness, as shown by the leftward shift in the stress-strain curve and inward hypotrophic remodeling, a characteristic of chronic reduction in blood flow. On the other hand, resistance arteries from germ-free female mice were similar in the stress-strain curves to that of conventionally raised mice, but were distinctly different and showed outward hypertrophic remodeling, a characteristic seen in aging. Interestingly, we observed that reactive oxygen species (ROS) generation from bone marrow derived neutrophils is blunted in female germ-free mice, but it is exacerbated in male germ-free mice. In conclusion, these observations indicate that commensal microbiota of a holobiont are central to maintain proper vascular function and structure homeostasis, especially in males.

Sodium, hypertension, and the gut: does the gut microbiota go salty?

Recent evidence suggests that the gut microbiota contributes to the pathogenesis of hypertension (HTN). The gut microbiota is a highly dynamic organ mediating numerous physiological functions, which can be influenced by external factors such as diet. In particular, a major modifiable risk factor for HTN is dietary sodium intake. Sodium consumption in the United States is significantly greater than that recommended by the federal government and organizations such as the American Heart Association. Because of the emerging connection between the gut microbiota and HTN, the interaction between dietary sodium and gut microbiota has sparked interest. High-sodium diets promote local and systemic tissue inflammation and impair intestinal anatomy compared with low sodium intake in both human and animal studies. It is biologically plausible that the gut microbiota mediates the inflammatory response, as it is in constant interaction with the immune system and is necessary for proper maturation of immune cells. Recent rodent data demonstrate that dietary sodium disrupts gut microbial homeostasis as gut microbiota composition shifts with dietary sodium manipulation. In this review, we will focus on gut microbiota activity in HTN and the influence of high dietary sodium intake with an emphasis on the immune system, bacterial metabolites, and the circadian clock.