ACE2 mRNA Expression Research Articles

Arachidonic acid inhibits the production of angiotensin-converting enzyme in human primary adipocytes via a NF-κB-dependent pathway.

BackgroundThe modulating mechanism of fatty acids on angiotensin-converting enzyme production (ACE) in human adipocytes is still elusive. Diet-induced regulation of the renin angiotensin system is thought to be involved in obesity and hypertension, and several previous studies have used mouse cell lines such as 3T3-L1 to investigate this. This study was carried out in human subcutaneous adipocytes for better understanding of the mechanism.MethodsHuman adipose stem cells were isolated from subcutaneous adipose tissue biopsies collected from four patients during bariatric surgery and differentiated into mature adipocytes. The mRNA expression and the activity of ACE were measured under different stimuli in cell cultures.ResultsArachidonic acid (AA) decreased ACE mRNA expression and ACE activity in a dose-dependent manner while palmitic acid had no effect. The decrease of ACE by 100 µM AA was reversed by the addition of 5 µM nuclear factor-κB (NF-κB) inhibitor. Furthermore, when the production of 20-hydroxyeicosatetraenoic acid, a metabolite of AA, was stopped by the specific inhibitor HET0016 (10 µM) in the culture media, the effect of AA was blocked.ConclusionsThis study indicated that AA can decrease the expression and activity of ACE in cultured human adipocytes, via an inflammatory NF-κB-dependent pathway. Blocking 20-hydroxyeicosatetraenoic acid attenuated the ACE-decreasing effects of AA.

The SARS-CoV-2 receptor, angiotensin-converting enzyme 2, is required for human endometrial stromal cell decidualization†.

The coronavirus disease 2019 (COVID-19) first appeared in December 2019 and rapidly spread throughout the world. The SARS-CoV-2 virus enters the host cells by binding to the angiotensin-converting enzyme 2 (ACE2). Although much of the focus is on respiratory symptoms, recent reports suggest that SARS-CoV-2 can cause pregnancy complications such as pre-term birth and miscarriages; and women with COVID-19 have had maternal vascular malperfusion and decidual arteriopathy in their placentas. Here, we report that the ACE2 protein is expressed in both endometrial epithelial and stromal cells in the proliferative phase of the menstrual cycle, and the expression increases in stromal cells in the secretory phase. It was observed that the ACE2 mRNA and protein abundance increased during primary human endometrial stromal cell (HESC) decidualization. Furthermore, HESCs transfected with ACE2-targeting siRNA impaired the full decidualization response, as evidenced by a lack of morphology change and lower expression of the decidualization markers PRL and IGFBP1. Additionally, in mice during pregnancy, the ACE2 protein was expressed in the uterine epithelial cells, and stromal cells increased through day 6 of pregnancy. Finally, progesterone induced Ace2 mRNA expression in mouse uteri more than vehicle or estrogen. These data establish a role for ACE2 in endometrial physiology, suggesting that SARS-CoV-2 may be able to enter endometrial stromal cells and elicit pathological manifestations in women with COVID-19, including an increased risk of early pregnancy loss.

Abstract 17314: Flow-Mediated Susceptibility of Cerebral Endothelia to Sars-CoV-2 Infection Using Endothelialized 3D Human Vascular Models

Introduction: The clinical syndrome associated with Sars-CoV-2 infection is associated with an increased rate of cerebrovascular events, predominantly ischemic stroke. Direct viral invasion of the cerebral endothelium could be a significant driver of Sars-CoV-2-mediated stroke through expression of ACE2 and viral entry co-factors including TMPRSS2. Prior work indicates that ACE2 mRNA and protein are expressed in the endothelial cells of the brain, yet the effect of flow-mediated phenomena on ACE2 expression and the susceptibility of human cerebral endothelia to Sars-CoV-2 infection is unknown. Methods: 3D printed models of the human middle cerebral artery were endothelialized with either human umbilical vein endothelial cells (HUVECs) or human brain microvascular endothelial cells (HBMECs). Endothelialized models were subjected to 3D rotational perfusional culture at variable pulsatile flow rates (0-22.5 dynes/cm 2 ). ACE2 and TMPRSS2 expression were measured by Taqman qPCR. Biotinylated recombinant Sars-CoV-2 S protein was used to judge regional vessel binding of virus using confocal microscopy. Results: In 3D models endothelialized with either HUVECs or HBMECs, ACE2 mRNA expression is significantly modulated by vessel diameter and the presence of of flow (15 dynes/cm 2 ) (p<0.0001 by two-way ANOVA). Pulsatile flow drives ACE2 expression more robustly in HUVECs than in HBMECs (11.5-fold vs. 4.9-fold; p<0.001). Higher flow rates (22.5 dynes/cm 2 ) produced further increases in ACE2 expression in both cell types. Gene expression analysis demonstrated no detection of the Sars-CoV-2 viral entry co-factor TMPRSS2 in HBMECs. Flow-mediated ACE2 expression was associated with binding of recombinant Sars-CoV-2 S protein to the vessel wall suggesting direct cerebrovascular susceptibility to Sars-CoV-2. Conclusion: The Sars-CoV-2 cellular receptor ACE2 is expressed by human cerebral endothelia in a flow-dependent manner. Cerebral vessels are susceptible to Sars-CoV-2 infection and bind viral S protein under flow conditions but likely requires unique co-factors for viral entry. Identification of the molecular mechanisms triggered by Sars-CoV-2 infection in brain vasculature can alleviate the burden of stroke associated with COVID-19.

ACE2 and gut amino acid transport.

ACE2 is a type I membrane protein with extracellular carboxypeptidase activity displaying a broad tissue distribution with highest expression levels at the brush border membrane (BBM) of small intestine enterocytes and a lower expression in stomach and colon. In small intestinal mucosa, ACE2 mRNA expression appears to increase with age and to display higher levels in patients taking ACE-inhibitors (ACE-I). There, ACE2 protein heterodimerizes with the neutral amino acid transporter Broad neutral Amino acid Transporter 1 (B0AT1) (SLC6A19) or the imino acid transporter Sodium-dependent Imino Transporter 1 (SIT1) (SLC6A20), associations that are required for the surface expression of these transport proteins. These heterodimers can form quaternary structures able to function as binding sites for SARS-CoV-2 spike glycoproteins. The heterodimerization of the carboxypeptidase ACE2 with B0AT1 is suggested to favor the direct supply of substrate amino acids to the transporter, but whether this association impacts the ability of ACE2 to mediate viral infection is not known. B0AT1 mutations cause Hartnup disorder, a condition characterized by neutral aminoaciduria and, in some cases, pellagra-like symptoms, such as photosensitive rash, diarrhea, and cerebellar ataxia. Correspondingly, the lack of ACE2 and the concurrent absence of B0AT1 expression in small intestine causes a decrease in l-tryptophan absorption, niacin deficiency, decreased intestinal antimicrobial peptide production, and increased susceptibility to inflammatory bowel disease (IBD) in mice. Thus, the abundant expression of ACE2 in small intestine and its association with amino acid transporters appears to play a crucial role for the digestion of peptides and the absorption of amino acids and, thereby, for the maintenance of structural and functional gut integrity.

SARS‐CoV‐2 evades immune detection in alveolar macrophages

Respiratory infections, like the current COVID‐19 pandemic, target epithelial cells in the respiratory tract. Alveolar macrophages (AMs) are tissue‐resident macrophages located within the lung. They play a key role in the early phases of an immune response to respiratory viruses. AMs are likely the first immune cells to encounter SARS‐CoV‐2 during an infection, and their reaction to the virus will have a profound impact on the outcome of the infection. Interferons (IFNs) are antiviral cytokines and among the first cytokines produced upon viral infection. In this study, AMs from non‐infectious donors are challenged with SARS‐CoV‐2. We demonstrate that challenged AMs are incapable of sensing SARS‐CoV‐2 and of producing an IFN response in contrast to other respiratory viruses, like influenza A virus and Sendai virus, which trigger a robust IFN response. The absence of IFN production in AMs upon challenge with SARS‐CoV‐2 could explain the initial asymptotic phase observed during COVID‐19 and argues against AMs being the sources of pro‐inflammatory cytokines later during infection.

Metabolic impact of weight loss induced reduction of adipose ACE-2 – Potential implication in COVID-19 infections?

Background & aimsAngiotensin converting enzyme (ACE)-2 is a modulator of adipose tissue metabolism. However, human data of adipose ACE-2 is rarely available. Considering that, ACE-2 is believed to be the receptor responsible for cell entry of SARS-CoV-2, a better understanding of its regulation is desirable. We therefore characterized the modulation of subcutaneous adipose ACE-2 mRNA expression during weight loss and the impact of ACE-2 expression on weight loss induced short- and long-term improvements of glucose metabolism. Methods143 subjects (age > 18; BMI ≥ 27 kg/m2) were analyzed before and after a standardized 12-week dietary weight reduction program. Afterwards subjects were randomized to a 12-month lifestyle intervention or a control group (Maintain-Adults trial). Insulin sensitivity (IS) was estimated by HOMA-IR (as an estimate of liver IS) and ISIClamp (as an estimate of skeletal muscle IS). ACE-2 mRNA expression (ACE-2AT) was measured in subcutaneous adipose tissue before and after weight loss. ResultsACE-2AT was not affected by obesity, but was reduced in insulin resistant subjects. Weight loss resulted in a decline of ACE-2AT (29.0 (20.0–47.9) vs. 21.0 (13.0–31.0); p = 1.6 ∗ 10−7). A smaller reduction of ACE-2 AT (ΔACE-2AT) was associated with a larger improvement of ISIClamp (p = 0.013) during weight reduction over 3 months, but not with the extend of weight loss. The degree of changes in insulin resistance were preserved until month 12 and was also predicted by the weight loss induced degree of ΔACE-2AT (p = 0.011). ConclusionsOur data indicate that subcutaneous adipose ACE-2 expression correlates with insulin sensitivity. Weight loss induced decline of subcutaneous adipose ACE-2 expression might affect short- and long-term improvement of myocellular insulin sensitivity, which might be also relevant in the context of ACE-2 downregulation by SARS-CoV-2.Trial registration: ClinicalTrials.gov number: NCT00850629, https://clinicaltrials.gov/ct2/show/NCT00850629, date of registration: February 25, 2009.

Expression of ACE2, the SARS-CoV-2 Receptor, in Lung Tissue of Patients With Type 2 Diabetes

Increased expression of pulmonary ACE2, the SARS-CoV-2 receptor, could contribute to increased infectivity of COVID-19 in patients with diabetes, but ACE2 expression has not been studied in lung tissue of subjects with diabetes. We therefore studied ACE2 mRNA and protein expression in lung tissue samples of subjects with and without diabetes that were collected between 2002 and 2020 from patients undergoing lobectomy for lung tumors. For RT-PCR analyses, samples from 15 subjects with diabetes were compared with 91 randomly chosen control samples. For immunohistochemical staining, samples from 26 subjects with diabetes were compared with 66 randomly chosen control samples. mRNA expression of ACE2 was measured by quantitative RT-PCR. Protein levels of ACE2 were visualized by immunohistochemistry on paraffin-embedded lung tissue samples and quantified in alveolar and bronchial epithelium. Pulmonary ACE2 mRNA expression was not different between subjects with or without diabetes. In contrast, protein levels of ACE2 were significantly increased in both alveolar tissue and bronchial epithelium of patients with diabetes compared with control subjects, independent of smoking, chronic obstructive pulmonary disease, BMI, renin-angiotensin-aldosterone system inhibitor use, and other potential confounders. To conclude, we show increased bronchial and alveolar ACE2 protein expression in patients with diabetes. Further research is needed to elucidate whether upregulation of ACE2 expression in airways and lungs has consequences on infectivity and clinical outcomes of COVID-19.

New angiotensin-converting enzyme inhibitory peptide from Coix prolamin and its influence on the gene expression of renin-angiotensin system in vein endothelial cells

Coix seed, which is a traditional Chinese medicine, has been used to treat hypertension for thousands of years. It has been shown that Coix prolamin peptides display high levels of angiotensin I converting enzyme (ACE) inhibitory activity. Hence, we purified the ACE inhibitory peptides from Coix prolamin hydrolysates and evaluated the influence of the most potent peptide on the renin-angiotensin system (RAS) genes expression in human umbilical vein endothelial cells (HUVECs). In this study, Coix prolamin peptides were sequentially separated by ultrafiltration, ion exchange chromatography, gel filtration chromatography and RP-HPLC, while the peptide structure was analyzed by mass spectrometry. Next, in silico proteolysis, pharmacophore and molecular docking were further applied to screen and optimize the structure of peptides. Finally, a novel ACE inhibitory peptide VDMF was obtained, in which its influence on the gene expression of RAS signaling pathway in AngⅡ-injury HUVECs was evaluated by quantitative real-time PCR. VDMF significantly down-regulated ACE, AngII type 1 receptor (AT1R) and ACE2 mRNA expression in comparation with model group, while up-regulating Mas gene expression. Hence, we obtained a novel antihypertensive candidate that was derived from the Coix peptides, which could involve a multi-modulation mechanism that regulates blood pressure.

Uncovering the mechanisms of leech and centipede granules in the treatment of diabetes mellitus-induced erectile dysfunction utilising network pharmacology

Ethnopharmacological relevanceDiabetes mellitus-induced erectile dysfunction (DMED) is one of the most common complications of diabetes mellitus. Leech and centipede granules (LCG) have traditionally been used as blood-activating agents in various ethnomedicinal systems of East Asia, especially in China. It is often used to regulate bodily functions and considered as adjuvant therapy for promoting blood circulation, alleviating blood coagulation, activating meridians, and relieving stasis. Aim of the studyThis study aimed to identify potential genes and mechanisms of LCG on DMED from the network pharmacological perspective. Materials and methodsThe active components of LCG were identified by UHPLC-Q-TOF-MS, TCMID, and the BATMAN-TCM databases, and the disease targets of DMED were obtained from the DisGeNET, CooLGeN, GeneCards databases. After identifying DMED targets of LCG, a protein-protein interaction (PPI) network was constructed. Hub genes and significant modules were identified via the MCODE plug-in of Cytoscape software. Then, significant signaling pathways of the modules were identified using the Metascape database. The probable interaction mode of compounds-hub genes is examined using Molecular Operating Environment (MOE) docking software. Besides, we investigated the effects and mechanisms of LCG on improving erectile function in the streptozotocin (STZ)-induced diabetic rats model. ResultsCombined UHPLC-Q-TOF-MS analysis with network pharmacology study, 18 active compounds were selected for target prediction. There are 97 common target genes between LCG and DMED. Enrichment of the KEGG pathway mainly involves in the calcium signaling pathway, NF-kappa B signaling pathway, cGMP-PKG signaling pathway, HIF-1 signaling pathway, PI3K-Akt signaling pathway, and mTOR signaling pathway. Nine hub genes were regulated by LCG in DMED, including CXCL8, NOS3, CRH, TH, BDNF, DRD4, ACE, CNR1, and HTR1A. The results of molecular docking analysis showed that the tyrosin, ursolic acid, and L-Histidine has a relatively stable interaction with corresponding hub genes via generating hydrogen bonds, H-π, and π-π interactions. Significantly, the results in docking predicted a higher affinity of vardenafil to the hub genes compared to the tyrosin, ursolic acid, and L-Histidine. Furthermore, LCG increased the testosterone, erection frequency, the ratio of ICP and MAP, SOD, cGMP, cAMP as well as decreased the MDA, and AGEs expression levels. And, LCG ameliorated the histological change of penile tissues in DMED rats. Hence, LCG attenuates oxidative stress, increases NO production; For the mechanism exploration, LCG could significantly upregulate the mRNA and protein expression of CNR1, NOS3, CRH, TH, BDNF, and DRD4, whereas CXCL8, ACE, and HTR1A levels were significantly higher than those in the DMED group. Moreover, LCG activates the NO/cGMP/PKG pathway, PI3K/Akt/nNOS pathway, cAMP/PKA pathway, and inhibits the HIF-1α/mTOR pathway to improve erectile function. ConclusionsOur results suggest that LCG maybe offer a new therapeutic basis for the treatment of DMED via altering the gene expression of involved metabolic pathways.

Intrarenal Renin Angiotensin System Imbalance During Postnatal Life Is Associated With Increased Microvascular Density in the Mature Kidney.

Environmental stress during early life is an important factor that affects the postnatal renal development. We have previously shown that male rats exposed to maternal separation (MatSep), a model of early life stress, are normotensive but display a sex-specific reduced renal function and exacerbated angiotensin II (AngII)-mediated vascular responses as adults. Since optimal AngII levels during postnatal life are required for normal maturation of the kidney, this study was designed to investigate both short- and long-term effect of MatSep on (1) the renal vascular architecture and function, (2) the intrarenal renin-angiotensin system (RAS) components status, and (3) the genome-wide expression of genes in isolated renal vasculature. Renal tissue and plasma were collected from male rats at different postnatal days (P) for intrarenal RAS components mRNA and protein expression measurements at P2, 6, 10, 14, 21, and 90 and microCT analysis at P21 and 90. Although with similar body weight and renal mass trajectories from P2 to P90, MatSep rats displayed decreased renal filtration capacity at P90, while increased microvascular density at both P21 and P90 (p < 0.05). MatSep increased renal expression of renin, and angiotensin type 1 (AT1) and type 2 (AT2) receptors (p < 0.05), but reduced ACE2 mRNA expression and activity from P2-14 compared to controls. However, intrarenal levels of AngII peptide were reduced (p < 0.05) possible due to the increased degradation to AngIII by aminopeptidase A. In isolated renal vasculature from neonates, Enriched Biological Pathways functional clusters (EBPfc) from genes changed by MatSep reported to modulate extracellular structure organization, inflammation, and pro-angiogenic transcription factors. Our data suggest that male neonates exposed to MatSep could display permanent changes in the renal microvascular architecture in response to intrarenal RAS imbalance in the context of the atypical upregulation of angiogenic factors.

SARS-CoV-2 receptor ACE2 gene expression in small intestine correlates with age.

Gastrointestinal symptoms are common in COVID-19 patients, especially in younger patients. Our hypothesis was that intestinal SARS-CoV-2 receptor ACE2 expression depends on patients’ age. We examined duodenal biopsies from 43 healthy human adults. ACE2 gene expression was directly correlated with age (Spearman’s r = 0.317, p = 0.039). With each year, duodenal ACE2 expression increased by 0.083 RU. The higher intestinal ACE2 mRNA expression in older patients may impact on their susceptibility to develop intestinal symptoms.

Comparative analysis of SARS-CoV-2 receptor ACE2 expression in multiple solid tumors and matched non-diseased tissues

The emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses a global public health emergency. SARS-CoV-2 employs the host cell receptor ACE2 for cellular entry. Nonetheless, the differences in ACE2 expression pattern in lung versus other normal and solid tumor tissues remain incompletely characterized. Here, we analyze a large data set comprising ACE2 mRNA expression for 7592 tissue samples across 22 types of primary solid tumor and 4461 samples across matched 18 non-diseased tissues. Our results unravel eight normal tissues and 10 primary solid tumors, which might be at high risk of SARS-CoV-2 infection. These findings may provide additional insight into the prevention and treatment of SARS-CoV-2 infection, in particular for patients with these 10 vulnerable cancer types.

Nrf2 Activator PB125® as a Potential Therapeutic Agent against COVID-19.

Nrf2 is a transcription factor that regulates cellular redox balance and the expression of a wide array of genes involved in immunity and inflammation, including antiviral actions. Nrf2 activity declines with age, making the elderly more susceptible to oxidative stress-mediated diseases, which include type 2 diabetes, chronic inflammation, and viral infections. Published evidence suggests that Nrf2 activity may regulate important mechanisms affecting viral susceptibility and replication. We examined gene expression levels by GeneChip microarray and by RNA-seq assays. We found that the potent Nrf2-activating composition PB125® downregulates ACE2 and TMPRSS2 mRNA expression in human liver-derived HepG2 cells. ACE2 is a surface receptor and TMPRSS2 activates the spike protein for SARS-CoV-2 entry into host cells. Furthermore, in endotoxin-stimulated primary human pulmonary artery endothelial cells, we report the marked downregulation by PB125 of 36 genes encoding cytokines. These include IL-1-beta, IL-6, TNF-α, the cell adhesion molecules ICAM-1, VCAM-1, and E-selectin, and a group of IFN-γ-induced genes. Many of these cytokines have been specifically identified in the “cytokine storm” observed in fatal cases of COVID-19, suggesting that Nrf2 activation may significantly decrease the intensity of the storm.

Training-Induced Deactivation of the AT1 Receptor Pathway Drives Autonomic Control and Heart Remodeling During the Transition From the Pre- to Hypertensive Phase in Spontaneously Hypertensive Rats.

The effects of hypertension and exercise training (T) on the sequential interplay between renin-angiotensin system (RAS), autonomic control and heart remodeling during the development of hypertension in spontaneously hypertensive rats (SHR), was evaluated.Methods and Results:Time course changes of these parameters were recorded in 4-week-old SHR submitted to a T or sedentary (S) protocol. Wistar Kyoto rats served as controls. Hemodynamic recordings were obtained in conscious rats at experimental weeks 0, 1, 2, 4, and 8. The left ventricle (LV) was collected to evaluate RAS gene and protein expression, cardiomyocytes' hypertrophy and collagen accumulation. Pre-hypertensive SHR exhibited augmented AT1R gene expression; at 5 weeks, they presented with elevated pressure, increased LV angiotensinogen and ACE mRNA expression, followed by sympathoexcitation (from the 8thweek onwards). Marked AT1R protein content, myocytes's hypertrophy, collagen deposition and increased pressure variability were observed in 12-week-old sedentary SHR. In addition to attenuating all these effects, T activated Mas receptor expression augmented parasympathetic modulation of the heart, and delayed the onset and reduced the magnitude, but did not block the development of genetic hypertension. The close temporal relationship between changes in the LV ACE-Ang II-AT1R axis, autonomic control and cardiac remodeling at both the establishment of hypertension and during exercise training reveals the essential role played by the AT1R pathway in driving cardiac remodeling and autonomic modulation during the transition from the pre- to hypertensive phase.

Inhibition of RAGE by FPS-ZM1 alleviates renal injury in spontaneously hypertensive rats

The current study was designed to examine the protection of RAGE-specific inhibitor FPS-ZM1 against renal injury in spontaneously hypertensive rats (SHR) and investigate the underlying mechanism. The adult male SHR were treated with FPS-ZM1 via oral gavages for 12 weeks, and age-matched male Wistar-Kyoto rats (WKY) were used as control. Treatment of SHR with FPS-ZM1 slightly reduced blood pressure, and significantly improved baroreflex sensitivity in SHR. Treatment of SHR with FPS-ZM1 improved renal function, evidenced by increased glomerular filtration rate and renal blood flow, and reduced plasma creatinine, blood urea nitrogen and urine albumin excretion rate. Histology results revealed that treatment of SHR with FPS-ZM1 alleviated renal injury and reduced tubulointerstitial fibrosis. Treatment of SHR with FPS-ZM1 suppressed activation of NF-κB and reduced expression of pro-inflammatory cytokines including Tnf, Il6, and Il1b. Treatment of SHR with FPS-ZM1 abated oxidative stress and downregulated mRNA levels of components of NADPH oxidase (Nox) including Cyba, Nox1, Nox2, Nox4 and Ncf1 in kidneys. In addition, treatment of SHR with FPS-ZM1 reduced renal AngII levels, downregulated mRNA expression of Ace and upregulated expression of Agtr2. In conclusion, treatment with FPS-ZM1 alleviated hypertension-related renal dysfunction, possibly by suppressing NF-κB-mediated inflammation, abating Nox-mediated oxidative stress, and improving local renal renin-angiotensin system (RAS).

Hypertension Programmed by Perinatal High-Fat Diet: Effect of Maternal Gut Microbiota-Targeted Therapy.

Hypertension can originate in early life caused by perinatal high-fat (HF) consumption. Gut microbiota and their metabolites short chain fatty acids (SCFAs), trimethylamine (TMA), and trimethylamine N-oxide (TMAO) are involved in the development of hypertension. Despite the beneficial effects of prebiotic/probiotic on human health, little is known whether maternal use of prebiotics/probiotics could protect offspring against the development of hypertension in adulthood. We investigated whether perinatal HF diet-induced programmed hypertension in adult offspring can be prevented by therapeutic uses of prebiotic inulin or probiotic Lactobacillus casei during gestation and lactation. Pregnant Sprague–Dawley rats received regular chow or HF diet (D12331, Research Diets), with 5% w/w long chain inulin (PRE), or 2 × 108 CFU/day Lactobacillus casei via oral gavage (PRO) during pregnancy and lactation. Male offspring (n = 8/group) were assigned to four groups: control, HF, PRE, and PRO. Rats were sacrificed at 16 weeks of age. Maternal prebiotic or probiotic therapy prevents elevated blood pressure (BP) programmed by perinatal HF consumption. Both prebiotic and probiotic therapies decreased the Firmicutes to Bacteroidetes ratio and renal mRNA expression of Ace, but increased abundance of genus Lactobacillus and Akkermansia. Additionally, prebiotic treatment prevents HF-induced elevation of BP is associated with reduced fecal propionate and acetate levels, while probiotic therapy restored several Lactobacillus species. Maternal probiotic or prebiotic therapy caused a reduction in plasma TMAO level and TMAO-to-TMA ratio. The beneficial effects of prebiotic or probiotic therapy on elevated BP programmed by perinatal HF diet are relevant to alterations of microbial populations, modulation of microbial-derived metabolites, and mediation of the renin-angiotensin system. Our results cast a new light on the use of maternal prebiotic/probiotic therapy to prevent hypertension programmed by perinatal HF consumption. The possibility of applying gut microbiota-targeted therapies as a reprogramming strategy for hypertension warrants further clinical translation.

Effects of Phytochemicals on Blood Pressure and Neuroprotection Mediated Via Brain Renin-Angiotensin System.

Background: The renin-angiotensin system (RAS) in the brain plays a crucial role in maintaining blood pressure as well as neuroprotection. This study compared the effects of curcumin, quercetin, and saponin on blood pressure, the brain RAS, and cholinergic system using perindopril, an angiotensin converting enzyme inhibitor (ACEI), as a positive control. Methods: Five-week-old male mice were stabilized and randomly assigned into a control group (n = 8), three phytochemical-treated groups (curcumin (n = 8), quercetin (n = 8), and saponin (n = 8)), and a positive control group (n = 8). The groups treated with the phytochemical were orally administered daily at a dose of 50 mg/kg body weight of phytochemicals. During the experiments, the weight and dietary intakes were measured regularly. After experiments, the brain tissue was homogenized and centrifuged for an additional assay. The concentrations of ACE, angiotensin II (AngII), and aldosterone levels were measured, and the mRNA expressions of renin and ACE were measured. As biomarkers of neuroprotection, the concentrations of acetylcholine (ACh) as well as the concentration and activity of acetylcholine esterase (AChE) were measured. Results: After 4 weeks of treatment, the perindopril group showed the lowest blood pressure. Among the groups treated with the phytochemicals, treatment with curcumin and saponin significantly reduced blood pressure, although such effect was not as high as that of perindopril. Among phytochemicals, curcumin treatment significantly inhibited the concentration and activity of ACE, concentration of AngII, and mRNA expression of ACE. All phytochemical treatments significantly increased the concentration of ACh. The levels of AChE activity in groups exposed to curcumin or saponin (not quercetin) were significantly inhibited, Conclusion: Curcumin administration in rats reduced blood pressure by blocking the brain RAS components and protected the cholinergic system in brain by inhibiting the activity of AChE.

Exercise training attenuates hypertension and cardiac hypertrophy via time‐related regulation on ACE and ACE2 axes

Appropriate exercise training (ExT) has been shown to lower high blood pressure. However, prehypertension ExT has rarely been concerned. This study tested whether prehypertension ExT protects against hypertension and cardiac remodeling in spontaneously hypertensive rats (SHR), and explored the underlying mechanisms by examining cardiac angiotensin converting enzyme (ACE) and ACE2 axes. Low-intensity ExT was started in male SHR and control Wistar-Kyoto rats prior to the onset of hypertension, and lasted for either 8 or 16 weeks. Blood pressure (BP) was measured biweekly by the tail-cuff method. Cardiac function and remodeling were assessed, and ACE and ACE2 axes were determined after the final ExT. The results showed that prehypertension ExT slowed down the onset and progression of hypertension in SHR. In parallel, the hypertrophy in hypertensive heart was attenuated, myocardial fibrosis was reduced, and the impairment of left ventricular diastolic function was relieved. In SHR myocardium, the elements of ACE-AngII-AT1 axis were homogeneously and progressively increased, whereas those of ACE2-Ang(1–7)-MAS axis were heterogeneously decreased. Different time-related responses were observed for the key effecters, Ang II and Ang(1–7). Myocardial Ang II was increased progressively in SHR, and was reduced consistently by ExT. In contrast, Ang(1–7) was decreased only after 16-week sedentariness, which was abolished by ExT. Besides, 16-week ExT increased Ang(1–7) in normotensive control rats. In summary, prehypertension ExT attenuates hypertension and cardiac remodeling. Down-regulation of Ang II seems to serve as a protective mechanism throughout ExT, while up-regulation of Ang(1–7) is involved after a relatively long period of ExT. Support or Funding Information This work was supported by the National Natural Science Foundation of China (No. 81372111, 81670295), and the Natural Science Foundation of Fujian Province of China (No. 2014J01339). mRNA and protein levels of ACE and AT1 in left ventricles of WKY and SHR after 8 or 16 weeks of exercise training. mRNA and protein Expression of ACE2 and MAS receptor in left ventricles of WKY and SHR after 8 or 16 weeks of exercise training. This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

A1059 Telmisartan upregulates ACE2-Ang-(1–7)-Mas axis and affects retinal vessel endothelial cell apoptosis

Objectives: To investigate the effects of angiotensin II antagonist telmisartan regulate the ACE2-Ang-(1–7)-Mas axis in rats with spontaneous hypertension and effects on retina endothelial cell apoptosis. Methods: Thirty-three spontaneous hypertension rats were divided into 3 groups (SHR, SHRT and SHRTA group), the SHRT group were treated with telmisartan 10 mg/(kg.d) by intragastric administration, the SHRTA group were treated with telmisartan 10 mg/(kg.d) by intragastric administration and A-779 0.5 mg/(kg.d) by intravenous injection at the same time. After 24 weeks, rats were sacrificed. Results: The expression of retinal ACE2 mRNA and protein in SHR group is lower in both groups of WKY and SHRT. The expression of retinal ACE2 mRNA and protein in SHRT group has no significantly differently compared with SHRTA group. The expression of retinal MAS mRNA and protein in SHR group is lower in both groups of WKY and SHRT, the expression of retinal MAS mRNA and protein in SHRTA group is lower than the SHRT group. The ELISA of serum Ang-(1–7) shows the expression of Ang-(1–7) protein in SHR group is lower in both groups of WKY and SHRT, the expression of Ang-(1–7) protein in SHRTA group is lower than the SHRT group. Specimens of retinal vessel in SHR group shows a large area of cell-free capillary was emerged in SHR group, and artery stenosis partially, there were no shadows of pericytes and endothelial cells in retinal capillary. The positive TUNEL cells are staining brown. The apoptosis rates of capillary in SHR group is lower in both groups of WKY and SHRT, the apoptosis rates of capillary in SHRTA group is lower than the SHRT group. Conclusion: Telmisartan can upregulate the ACE2-Ang-(1–7)-Mas axis in retina and protect the apoptosis in retina vessel endothelial cell.

Abstract 136: Attenuation of Increased Blood Pressure by Chronic Estrogen Supplementation in Female IUGR Offspring at 12 months of Age is Associated With a Shift Towards ACE2

Low birth weight ( LBW ) women exhibit an earlier age at menopause and a two-fold greater prevalence of hypertension in later life. In a model of LBW induced via placental insufficiency in the rat, female LBW rats develop an increase in blood pressure ( BP ) by 12 months of age. This is associated with persistent estrous that occurs 6 months prior to controls, indicative of early reproductive senescence. Although the underlying mechanisms are unknown, a shift in the hormonal milieu in addition to dysregulation of the renin angiotensin system ( RAS ) are potential contributors to the increase in BP that occurs in women after menopause. The vasoconstrictor arm of the RAS is implicated in increased BP; ACE2 counterbalances this shift towards increased BP. We previously reported that renal ACE2 expression is elevated in female LBW rats that are normotensive in young adulthood; an increase that is not present in female LBW rats in later life. Thus, this study tested the hypothesis that chronic 17β-estradiol ( E2 ) supplementation would reduce BP and shift the balance of the RAS in female LBW rats. Placebo or E2 pellets (1.5mg 17β-estradiol, 60-day release) were implanted at 12 months of age for 6 weeks followed by measurement of BP in conscious, chronically catheterized animals. Kidneys were collected for molecular analysis. BP was significantly increased in placebo-treated LBW relative to placebo-treated Control (134 vs 122 mmHg, respectively, p &lt;0.05); an increase that was abolished by chronic E2 in LBW (116 mmHg, p &lt;0.05). Using Real-Time PCR, cortical ACE2 mRNA expression did not differ between Control or LBW rats. Medullary ACE2 mRNA expression was significantly increased in placebo-treated LBW compared to placebo-treated Controls (1-fold increase; p &lt;0.05). However, following chronic E2, medullary ACE2 mRNA expression was increased to a greater degree in chronic E2-treated LBW rats, almost two-fold higher, relative to chronic E2-treated Control. Therefore, these results suggest that E2 supplementation attenuates increased BP in female LBW rats in a manner that may involve a shift in the RAS towards ACE2 abundance suggesting that ACE2 via chronic E2 may be beneficial in the treatment of increased BP that occurs after reproductive senescence in LBW.