Polymorphism in NOD2, Crohn's disease, and susceptibility to pulmonary tuberculosis

The nucleotide oligomerization binding domain 2 gene (NOD2) encodes an intracellular receptor for bacterial components, which is expressed in monocytes and is associated with Crohn's Disease (CD). This finding, along with epidemiological evidence, supports a role for infection in the pathogenesis of CD. Speculation that mycobacteria are involved in CD led us to investigate NOD2 in susceptibility to tuberculosis (TB), a global public health problem caused by Mycobacterium tuberculosis. CD-associated NOD2 variants were absent in a case-control study of 640 Gambians, where CD is rare. Novel NOD2 promoter polymorphisms were identified but showed no association with TB in this African population sample.     

Differential expression of neuronal ACE2 in transgenic mice with overexpression of the brain renin-angiotensin system

Angiotensin-converting enzyme 2 (ACE2) is a newly discovered carboxy-peptidase responsible for the formation of vasodilatory peptides such as angiotensin-(1-7). We hypothesized that ACE2 is part of the brain renin-angiotensin system, and its expression is regulated by the other elements of this system. ACE2 immunostaining was performed in transgenic mouse brain sections from neuron-specific enolase-AT(1A) (overexpressing AT(1A) receptors), R(+)A(+) (overexpressing angiotensinogen and renin), and control (nontransgenic littermates) mice. Results show that ACE2 staining is widely distributed throughout the brain. Using cell-type-specific antibodies, we observed that ACE2 staining is present in the cytoplasm of neuronal cell bodies but not in glial cells. In the subfornical organ, an area lacking the blood-brain barrier and sensitive to blood-borne angiotensin II, ACE2 was significantly increased in transgenic mice. Interestingly, ACE2 mRNA and protein expression were inversely correlated in the nucleus of tractus solitarius/dorsal motor nucleus of the vagus and the ventrolateral medulla, when comparing transgenic to nontransgenic mice. These results suggest that ACE2 is localized to the cytoplasm of neuronal cells in the brain and that ACE2 levels appear highly regulated by other components of the renin-angiotensin system, confirming its involvement in this system. Moreover, ACE2 expression in brain structures involved in the control of cardiovascular function suggests that the carboxypeptidase may have a role in the central regulation of blood pressure and diseases involving the autonomic nervous system, such as hypertension.     

自发性高血压大鼠心脏中ACE,AT1R,ACE2和MasR表达变化的研究

目的：通过观察血管紧张素转化酶（ACE）和血管紧张素转化酶2（ACE2）在Wistar-京都种大鼠（WKY）和自发性高血压（SHR）大鼠心脏组织中表达的差异,探讨ACE与ACE2在自发性高血压大鼠高血压形成中的作用。方法：自由饲喂14周龄WKY和SHR雄性大鼠一周后,用BSN-II多通道无创测压系统测定大鼠收缩压（SBP）、舒张压（DBP）、心率（HR）并称重;放免法测定血浆中血管血管紧张素Ⅱ（AngII）含量;Real-time PCR测定心脏组织中ACE,ATI受体（ATIR）,ACE2和Mas受体（MasR）mRNA的表达水平;Western blot法检测心脏组织中ACE2的蛋白表达。结果：SHR大鼠SBP和DBP均显著高于WKY大鼠（P〈0.01）;两组大鼠心率和体重无显著差异（P〉0.05）;SHR大鼠血浆中AngII含量显著升高（P〈0.05）;与WKY大鼠相比,SHR大鼠心脏中ACE mRNA表达均显著升高（P〈0.05）,ACE2的mRNA和蛋白表达水平均显著下降（P〈0.05）;心脏组织中AT1R和MasR的mRNA表达没有显著性变化（P〉0.05）。结论：ACE与ACE2表达失调是SHR大鼠高血压形成的主要原因之一,其机理可能与局部组织RAS系统ACE-AngII-AT1R通路过度活跃,ACE2-Ang（1-7）-MasR通路相对不足有关。     

ACE2 and AT4R are present in diseased human blood vessels

A growing body of evidence suggests that the angiotensin II fragments, Ang(1-7) and Ang(3-8), have a vasoactive role, however ACE2, the enzyme that produces Ang(1-7), or AT4R, the receptor that binds Ang (3-8), have yet been simultaneously localised in both normal and diseased human conduit blood vessels. We sought to determine the immunohistochemical distribution of ACE2 and the AT4R in human internal mammary and radial arteries from patients undergoing coronary artery bypass surgery. We found that ACE2 positive cells were abundant in both normal and diseased vessels, being present in neo-intima and in media. ACE2 positive immunoreactivity was not present in the endothelial layer of the conduit vessels, but was clearly evident in small newly formed angiogenic vessels as well as the vaso vasorum. Endothelial AT4R immunoreactivity were rarely observed in either normal and diseased arteries, but AT4R positive cells were observed adjacent to the internal elastic lamine in the internal mammary artery, in the neo-intima of radial arteries, as well as in the media of both internal mammary artery and radial artery. AT4R was abundant in vaso vasorum and within small angiogenic vessels. Both AT4R and ACE2 co-localised with smooth muscle cell alpha actin. This study identifies smooth muscle cell alpha actin positive ACE2 and AT4R in human blood vessels as well as in angiogenic vessels, indicating a possible role for these enzymes in pathological disease.     

Soluble ACE2-mediated cell entry of SARS-CoV-2 via interaction with proteins related to the renin-angiotensin system

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ACE2, B0AT1, and SARS-CoV-2 spike protein: Structural and functional implications

The coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has emerged as a public health crisis and led to tremendous economic devastation. The spike protein (S) of SARS-CoV-2 hijacks the angiotensin converting enzyme 2 (ACE2) as a receptor for virus entry, representing the initial step of viral infection. S is one of the major targets for development of the antiviral drugs, antibodies, and vaccines. ACE2 is a peptidase that plays a physiologically important role in the renin–angiotensin system. Concurrently, it also forms dimer of heterodimer with the neutral amino acid transporter B⁰AT1 to regulate intestinal amino acid metabolism. The symptoms of COVID-19 are closely correlated with the physiological functions of ACE2. In this review, we summarize the functional and structural studies on ACE2, B⁰AT1, and their complex with S of SARS-CoV-2, providing insights into the various symptoms caused by viral infection and the development of therapeutic strategies.     

不同年龄白发性高血压大鼠肾脏AT1R和AT2R的表达

目的本研究观察不同月龄自发性高血压大鼠（SHR）肾脏ALR和ALR表达,初步探讨AT1R和AT2R在高血压发生、发展过程中的可能作用。方法1月龄组（S1）、2月龄组（S2）、3月龄组（S3）、6月龄组（S6）和9月龄组（墨）雄性SHR共5组,每组各6只,各组均有相应月龄匹配的Wistar-Kyoto大鼠（WKY）作对照。采用RBP-I型大鼠血压心率测定仪测量大鼠尾动脉收缩压（SBP）;放免法测定血浆血管紧张素Ⅱ（AngⅡ）;免疫组化染色结合计算机图像分析方法测定肾脏AT1R和ALR表达水平。结果（1）SHR SBP随着月龄的增加而上升,S6后趋于稳定。（2）1个月后SHR血浆AngⅡ浓度均高于S1（P〈0.05）,而S2、S3、S6和S9之间无明显差别（P〉0.05）;1个月后SHR血浆AngⅡ浓度均高于相应配对的WKY组（P〈0.05）;而WKY各月龄组均无明显差别（P〉0.05）。（3）SHR肾脏AT1R随着月份的增加而增加（P〈0.05）,且高于相应配对的WKY组（P〈0.05）。SHR肾脏ABR随着月份的增加而降低,S6明显降低（P〈0.05）,S6和S9比较无明显差别（P〉0.05）;且均低于相应配对的WKY组（P〈0.05）。WKY各月龄组AT1R和AT2R无明显差别（P〉0.05）。结论SHR肾脏AT1R表达水平比WKY高,并随着年龄的增加而递增;AT2R表达水平比WKY低,并随着年龄的增加而降低。     

Association of permanent arterial hypertension with the renin-angiotensin and kinin-bradykinin system genes in children

A new approach, based on scoring, was proposed for a more objective estimation of the contribution of several genetic variants to a multifactorial disease. Two variants of the approach—genotype scoring and unfavorable factor scoring—were tested by analyzing the polymorphisms of REN (I9–83G>A), AGT (M235T), ACE (I/D), AGTR1 (1166A>C), ATGR2 (3123C>A), and BKR2 (?58T>C and I/D) in children with arterial hypertension (AH). Each of the two variants reported that the genes of the renin-angiotensin and kinin-brady-kinin systems play an important role in permanent AH in girls.     

Association study of renin-angiotensin system genes and hemostasis system genes with ischemic stroke among Russians of Central Russia

The analysis of alleles and genotypes frequencies of 14 SNP in genes of rennin-angiotensin system (REN, AGT, AGTR1, AGTR2, BKR2, ADRB2) and hemostasis system (FGB, F2, F5, F7, ITGB3, SERPINE1, MTHFR), as well as ACE insertion-deletion polymorphism in patients with stroke comparing to healthy controls matched by age, sex and ethnicity has been carried out. The genotyping procedure included the amplification of selected gene sequences following by hybridization of fluorescently labeled fragments with SNP-specific DNA probes. The analysis of allele frequencies of each gene separately revealed no statistically significant differences between groups of patients with stroke and healthy donors. Also the complex study has been performed to estimate the contribution of rennin-angiotensin system and hemostasis system genes to the genetic susceptibility to ischemic stroke among Russians from Central Russia using method MDR (Multifactor Dimensionality Reduction). The combination with increased risk for development of ischemic stroke was presented by complex genotype FGB G/- x ACE I/- x MTHFR C/- x SERPINE1 5G/5G (p = 0.03, OR = 2.4, 95% CI 1.1-5.3), which frequency was statistically significant higher in patients with stroke compared to healthy control.     

Polymorphism distribution of RYR1, PRKAG3, HFABP,MYF-5 and MC4R genes in crossbred pigs

This study was designed to screen the crossbred pigs for SNPs in five candidate genes, associated with pork quality traits and to differentiate their genotypes by PCR–RFLP. The results indicated that genotypes of crossbred pigs were NN (90%) and Nn (10%) for RYR1; RR (83%) and QR (17%) for PRKAG3; HH (98%), Hh (1%) and hh (1%) for HFABP; DD (99%) and CD (1%) for MYF-5; and AG (57%), GG (26%) and AA (17%) for MC4R SNPs, respectively. Allelic frequencies for five SNPs {RYR1 (1843C>T), PRKAG3 (c.599G>A), HFABP (c.1322C>T), MYF-5 (c.1205A>C) and MC4R (c.1426A>G)} were 0.95 and 0.05 (N/n), 0.08 and 0.92 (Q/R), 0.99 and 0.01 (H/h), 0.00 and 1.00 (C/D) and 0.45 and 0.55 (A/G), respectively. The effect of RYR1 (1843C>T) SNP was significant on pH₄₅ (P?<?0.05), pH₂₄ (P?<?0.05) and protein % (P?<?0.05). The PRKAG3 (c.599G>A) and MC4R (c.1426A>G) SNP had significant association with dressing percentages. The results revealed that RYR1, PRKAG3 and MC4R SNPs may be used in marker associated selection for pork quality traits in crossbred pigs.