The combination of ACE I/D and ACE2 G8790A polymorphisms revels susceptibility to hypertension: A genetic association study in Brazilian patients

The Association Between Genetic Variants in ACE1and ACE2 Genes with Susceptibility to COVID-19 Infection

Angiotensin-converting enzyme 2 (ACE2) receptors facilitate the entry of the causative virus severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) into target cells. Some ACE gene variants have been suggested to be involved in COVID-19 pathogenesis. So, the aim was to assess the association between ACE1 rs4646994 and ACE2 rs2285666 genes polymorphisms and the susceptibility and severity of COVID-19. This case-control study was conducted on 197 patients with COVID-19 and 197 healthy controls. ACE-1 insertion/deletion (I/D) (rs4646994) and ACE2 rs2285666 genes polymorphisms were determined by the amplification refractory mutation system- polymerase chain reaction (ARMS-PCR) technique. The DD genotype of ACE1 I/D polymorphism was associated with increased susceptibility to COVID-19 infection (p = 0.012), whereas the ID genotype of this polymorphism was associated with decreased susceptibility (p = 0.003) (significance level = 0.017). There was no significant association in allele and genotype distribution of ACE2 rs2285666 polymorphism between cases and controls. The ACE1 I/D polymorphism may be considered as a risk factor for COVID-19 susceptibility.

The frequency of the ACE I/D polymorphism in South America: a systematic review and meta-analysis

Angiotensin-converting enzyme (ACE) is a key component of the renin-angiotensin system and plays an important role in homeostasis and maintenance of blood pressure. However, little is known about allele and genotypic frequencies, as well as phenotypic characteristics associated with ACE polymorphism genotypes in South American populations. This study aimed to verify the allelic predominance and genotype frequency of ACE I/D polymorphism in South America and its association with the main diseases and related conditions. We conducted a systematic review considering studies published in the last 25 years available in PubMed, Scielo, LILACS, LIPECS, Coleciona SUS, CUMED, BINACIS, IBECS, and MEDLINE databases, resulting in the inclusion of 121 studies. Quality of the studies was assessed according to the Strengthening the Reporting of Genetic Association (STREGA) guidelines. We mapped the frequency of the ACE I/D polymorphism in South American populations. 8,856 (32.1%) subjects were DD, 13,050 were ID (47.4%), and 5,644 were II (20.5%) carriers. The main associated conditions included systemic arterial hypertension and other cardiovascular conditions, cardiorespiratory or respiratory characteristics, physical activity level, kidney conditions, aging-related diseases, as well as different types of cancers and metabolic conditions. 61.1% of the studies found no significant association between the respective conditions investigated and the ACE I/D polymorphism. Considering DD genotype or D allele, 21.5% of the studies observed negative and 4.9% positive outcomes. Regarding ID genotype, 4.1% of the studies identified negative and 0.8% positive outcomes, and for II genotype or I allele, 4.1% of the results had negative and 10.7% positive associations.

The 'Insertion/Deletion' Polymorphism, rs4340 and Diabetes Risk: A Pilot Study from a Hospital Cohort

The insertion/deletion, I/D polymorphism, in the gene encoding Angiotensin Converting Enzyme, ACE is a popular genetic marker for cardiovascular disease, CVD. With alarming rise in diabetes, the risk of CVD among Indian subjects is further enhanced. The present study explored the role of ACE I/D polymorphism, rs4340 as a genetic marker and its association with diabetes. Genomic DNA, isolated from a cohort of 410 urban subjects attending our hospital, was genotyped using polymerase chain reaction followed by electrophoresis. Among the subjects, 84 had type-2 diabetes and 68 had hypertension while 258 were free from these risk factors. Majority (57/84) of diabetic subjects were also suffering from hypertension. Genotype frequencies of ACE I/D polymorphism, of diabetic (84) patients were not different from that of non-diabetic subjects (258). In sharp contrast, we found significant differences, in genotype frequencies of women with diabetes (n = 38) compared to non-diabetic women (70). Diabetic women had significantly higher prevalence of the high risk 'D' allele. Analysis of odds ratio, OR revealed that women with 'D/D' genotype, exhibited threefold risk (OR 3.12, 95% CI 1.21-8.05; p = 0.018) of diabetes, in the recessive model (D/D vs I/I + I/D). Further when we analysed Odds ratio of diabetic women (8) who were free from hypertension, the results revealed even a greater, 6- fold (OR 6.0, 95% CI 1.29-27.96, p = 0.027) risk of diabetes for D/D homozygous women (D/D vs I/I + I/D). These results suggest 'sex-specific' association of ACE 'I/D' polymorphism, with type-2 diabetes, affecting women while there was no influence observed among men. In view of the increased cardiovascular mortality among Indians, data from our pilot study if confirmed in a larger cohort, could add value to our future intervention efforts.

Association of insertion /deletion polymorphism of ace gene with essential hypertension in patients of Khyber Pakhtunkhwa

Objective &Background

The exact cause of hypertension is unknown in about 90 to 95% patients, known as essential hypertension. Genes may play a crucial role in the pathology of essential hypertension. Gene for angiotensin converting enzyme (ACE) is found on long arm of chromosome 17q23, where 287 base pair insertion or deletion (I/D) polymorphism may occur. This study was aimed to assess the association of I/D polymorphism of ACE gene with blood pressure (BP) in Patients of Khyber Pakhtunkhwa (KPK).

Methods

This Descriptive Cross-sectional study was conducted from 1st June 2021 to 30th September 2021 at Kuwait Teaching Hospital, Peshawar. The genomic DNA was extracted from lymphocytes and PCR was performed for identification of ACE I/D polymorphism.

Results

Total 181 individuals (121 Hypertensive and 60 normal) were enrolled in the study. The measured systolic and diastolic BP in cases were 153.91mmHg±12.65 and 92.94mmHg±5.72, respectively while in control were 118.20±17.13 and 74.12mmHg±7.58, respectively. The Deletion Homozygous (DD), Insertion Homozygous (II) and Deletion and Insertion Heterozygous (DI) genotypes in hypertensive patients were 47 (38.84%), 17 (14.04%) and 57 (47.10%) respectively while in Control group the DD, II and DI were 4 (6.66%), 25 (41.66%) and 31 (51.66%) respectively. This study showed association of DD genotypes of the ACE gene with hypertension as compared to healthy individuals.

Conclusion

Individuals with DD genotype may have association with hypertension. polymorphism of ACE gene was proved to be an important genetic marker for essential hypertension in Patients of KPK.

Combinatorial analysis of ACE and ACE2 polymorphisms reveals protection against COVID-19 worsening: A genetic association study in Brazilian patients

Since angiotensin-converting enzyme 2, ACE2, was identified as the receptor for SARS-CoV-2 and considering the intense physiological interplay between the two angitensinases isoforms, ACE and ACE2, as counter-regulatory axis of the renin-angiotensin system, we proposed the evaluation of polymorphisms in these two key regulators in relation to COVID-19 severity. A genetic association study involving 621 COVID-19 hospitalized patients from Brazil was performed. All subjects had a confirmed diagnosis of COVID-19 via RT-PCR. Patients were categorized into two groups: the "mild" group (N = 296), composed of individuals hospitalized in ward beds who progressed to cure, and the "severe" group (N = 325), composed of individuals who required hospitalization in an intensive care unit (ICU), or who died. Blood samples were genotyped for ACE I/D polymorphism and ACE2 G8790A polymorphism by real-time PCR via TaqMan assay. The analysis of combined polymorphisms revealed a protective role for genotypic profile II/A_ (ORA = 0,26; p = 0,037) against the worsening of COVID-19 in women. The results indicate a protection profile to COVID-19 progression, in which the II/A_ carriers have almost four times less chance of a severe outcome. It is proposed that a decreased activity of ACE (deleterious effects) in conjunction with an increased ACE2 activity (protective effects), should be the underlying mechanism. The findings are unprecedented once other studies have not explored the genotypic combination analysis for ACE and ACE2 polymorphisms and bring perspectives and expectations for dealing with the COVID-19 pandemic based on definitions of genetically-based risk groups within the context of personalized medicine.

Sex Differences in the Efficacy of Mediterranean Diet Treatment: A Nutrigenomics Pilot Study

The Mediterranean diet (MedD) has been shown to have beneficial effects on health, well-being, and mental status. It potentially modulates gene expressions linked to oxidative stress, contributing to its beneficial effects on overall health. The aim of this study was to assess the effects of MedD treatment in healthy human volunteers on the expression of ten genes related to oxidative stress and inflammation in women and men. Of 30 enrolled subjects, 17 were eligible, 10 women and 7 men. All of them received the same MedD treatment. Before and after 8 weeks of MedD treatment, an evaluation of body composition, blood tests, and anthropometric and clinical parameters was performed. Furthermore, 10 genes were amplified and analyzed. The study showed significant differences between females and males in body composition and biochemical parameters before and after MedD treatment. Significant differences between females and males in Resistance Force (p < 0.009) and Diastolic Blood Pressure (p < 0.04) before MedD treatment, and in High-Density Lipoprotein (p < 0.02) after MedD treatment, were observed. Moreover, a significant upregulation of Apolipoprotein E and Angiotensin I-Converting Enzyme in females has been shown. Sex differences impact MedD treatment response, and influence the genetic expression of genes related to oxidative stress; our findings may help to personalize diet therapy and contribute to overall health and well-being.

Prognostic Value of CYP1A2 (rs2069514 and rs762551) Polymorphisms in COVID-19 Patients

The aim of the study was to examine the genotype-allele determination of CYP1A2 rs2069514 and rs762551 polymorphisms in patients with mild and severe COVID-19 and to determine their effectiveness as prognostic criteria in COVID-19. The study consists of 60 patients who were hospitalized in intensive care or outpatient treatment due to COVID-19 in Istanbul NP Brain Hospital between 2020-2021. Genotyping was conducted by Real-Time PCR. Age (p<0.001); chronic disease (p=0.002); cardiovascular disease (p=0.004); respiratory distress (p<0.001); neurological disease (p=0.004); fatigue (p=0.048); loss of taste and smell (p=0.003); nausea/vomiting (p=0.026); intubated (p<0.001); ground glass image (p<0.001) and CYP1A2 genotypes (p<0.001) showed a statistically significant difference between patients with and without intensive care admission. According to multivariate logistic regression analysis, CYP1A2 *1A/*1C + *1C/*1C genotypes (OR:5.23 95% CI: 1.22-22.36; p=0.025), chronic disease (OR:4.68 95% CI:1.14-19.15; p=0.032) or patients at 65 years or older (OR:5.17, 95%CI:1.26-21.14; p=0.022) increased the risk of admission to the intensive care unit. According to our results, we strongly suggest considering the CYP1A2 rs2069514 and rs762551 polymorphisms as important predictors of Intensive Care Unit admission in patients with COVID-19, and we also suggest that genotype results will guide clinicians for the benefit and the efficiency of the treatment.

Clinical Pharmacogenetics of Angiotensin II Receptor Blockers in Iraq

Background

Clinical pharmacogenetics is a rapidly growing field that focuses on the study of genetic variations and their impact on drug metabolism, efficacy, and safety. Angiotensin II receptor blockers (ARBs) are commonly used to treat hypertension in Iraq but not all patients respond equally to these drugs.

Aim

This article aims to review the current evidence on the clinical pharmacogenetics of ARBs in Iraq and its implications for personalized medicine.

Materials and Methods

We conducted a literature review of studies on the genetic variations that affect the response to ARBs in Iraq. We also reviewed the prevalence of these genetic variants in the Iraqi population and discussed the potential clinical implications for personalized medicine.

Results

The most studied genetic variations associated with ARB response in Iraq are the angiotensin-converting enzyme gene insertion/deletion polymorphism and the angiotensin II type 1 receptor gene A1166C polymorphism. The angiotensin-converting enzyme gene insertion/deletion polymorphism is associated with variability in response to ARBs, while the angiotensin II type 1 receptor A1166C polymorphism is associated with an increased risk of cardiovascular events in patients treated with ARBs. The prevalence of these genetic variants in the Iraqi population varies widely depending on the region and ethnic group.

Conclusion

The clinical pharmacogenetics of ARBs in Iraq suggests that pharmacogenetic testing could improve the selection and dosing of ARBs in Iraqi patients, leading to better patient outcomes and cost-effective healthcare.

Polymorphism of tmprss2 (rs12329760) but not ace2 (rs4240157), tmprss11a (rs353163) and cd147 (rs8259) is associated with the severity of COVID-19 in the Ukrainian population

BACKGROUND AND AIM

Angiotensin-converting enzyme 2 (ACE2), transmembrane serine 2 and serine 11A proteases (TMPRSS2, TMPRSS11A), and a cell surface cluster of differentiation 147 (CD147) might be a gene candidate that exerts the susceptibility to and mortality from coronavirus disease 19 (COVID-19). The aim of this study was to investigate the associations between ace2, tmprss2, tmprss11a, and cd147 polymorphic variants and the severity of COVID-19 in the Ukrainian population.

METHODS

The study population consisted of the Ukrainian population with COVID-19: patients without oxygen therapy (n=62), with non-invasive (n=92) and invasive (n=35) oxygen therapy, as well as control subjects (n=92). Allelic polymorphisms of ace2 rs4240157, tmprss2 rs12329760, and tmprss11a rs353163 were determined by real-time PCR, and cd147 rs8259 polymorphism was detected by PCR with subsequent restrictase analysis. We compared investigated polymorphisms distribution with other populations by meta-analysis.

RESULTS

Our study is the first to obtain data about the distribution of investigated gene polymorphisms in the Ukrainian population: tmprss2 rs12329760 - CC 60.9%, CT 35.9%, TT 3.2%; tmprss11a rs353163 - CC 46.7%, CT 40.2%, TT 13.1%; ace2 rs4240157 - CC 7.6%, C 18.5%, CT 22.8%, TT 19.6%, T 31.5%; cd147 rs8259 - TT 60.9%, AT 32.6%, AA 6.5%. This distribution was similar to the Northern, Western and Southern European populations. There was a statistically significant difference in the frequency of tmprss2 polymorphic genotypes CC 57.1%, CT 28.6%, and TT 14.3% (P<0.05) in COVID-19 patients with invasive oxygen therapy in comparison with non-invasive oxygen therapy. This tmprss2 mutation occurs in the scavenger receptor cysteine-rich (SRCR) domain and might be important for protein-protein interaction in a calcium-dependent manner.

CONCLUSIONS

Our study indicated the presence of an association between the tmprss2 rs12329760 polymorphism and the severity of COVID-19 in the Ukrainian population.

The effect of angiotensin converting enzyme gene insertion/deletion polymorphism on anthropometric and biochemical parameters among hypertension patients: A case-control study from Northwest Ethiopia

INTRODUCTION

The angiotensin-converting enzyme (ACE) gene polymorphism has recently been linked with altered anthropometric and biochemical parameters in hypertensive patients. However, these links are still poorly understood and there is scarce evidence on the topic. Therefore, this study aimed to assess the effect of ACE gene insertion/deletion (I/D) polymorphism on anthropometric and biochemical parameters among essential hypertension patients at the University of Gondar Comprehensive Specialized Hospital, Northwest Ethiopia.

MATERIALS AND METHODS

A case-control study with 64 cases and 64 controls was conducted from October 07, 2020, to June 02, 2021. The anthropometric measurements, biochemical parameters, and ACE gene polymorphism were determined using standard operating procedures, enzymatic colorimetric method, and polymerase chain reaction, respectively. A one-way analysis of variance was used to determine the association of genotypes with other study variables. P value < 0.05 was regarded as statistically significant.

RESULT

The systolic/diastolic blood pressure and blood glucose level (P-value<0.05) were significantly higher among study hypertensive patients with the DD genotype. However, anthropometric measures and lipid profiles of cases and controls were not associated with ACE gene polymorphism (P-value>0.05).

CONCLUSION

The DD genotype of the ACE gene polymorphism was found to have a significant association with high blood pressure and blood glucose levels in the study population. Advanced studies with a considerable sample size may be needed to utilize the ACE genotype as a biomarker for the early detection of hypertension-related complications.

Angiotensin-converting enzyme gene insertion/deletion polymorphism and risk of ischemic stroke complication among patients with hypertension in the Ethiopian population

Background

Ischemic stroke is a complicated, multifaceted condition brought on by a confluence of vascular, environmental, and genetic variables. The burden of ischemic stroke is currently rising in terms of death, morbidity, and disability worldwide. Genetic variables also play significant roles in the pathophysiology of hypertension and ischemic stroke in addition to the greatest effects of demographic, clinical, and behavioral risk factors. The key functional variation of the ACE gene that has drawn the most interest is the ACE I/D variant. Even though the ACE gene I/D polymorphism has been widely studied, the findings of investigations on the involvement of this polymorphism in ischemic stroke were contradictory and provide conflicting data. The goal of this study was to look into the effect of the ACE gene I/D polymorphism on the risk of ischemic stroke in patients with hypertension.

Methods

A hospital-based case-control study was carried out in 36 cases of patients with hypertensive IS and 36 age- and sex-matched healthy controls. Clinical and biochemical parameters were measured to assess the associated risk factors. The DNA was isolated from blood samples, and the ACE I/D genotypes were identified using polymerase chain reaction and analyzed by agarose gel electrophoresis.

Results

The ACE-DD genotype (OR = 3.71, 95% CI = 1.02-13.5; P < 0.05) and D allele (OR = 2.07, 95% CI = 1.06-4.03; P < 0.05) were significantly more common in patients than in controls, indicating that it is a risk factor for the development of ischemic stroke in hypertensive individuals.

Conclusion

There is a significant correlation between the ACE gene I/D polymorphism and the development of ischemic stroke in patients with a history of hypertension in the Ethiopian population.

Mutations in SARS-CoV-2: Insights on structure, variants, vaccines, and biomedical interventions

COVID-19 is a worldwide pandemic caused by SARS-coronavirus-2 (SARS-CoV-2). Less than a year after the emergence of the Covid-19 pandemic, many vaccines have arrived on the market with innovative technologies in the field of vaccinology. Based on the use of messenger RNA (mRNA) encoding the Spike SARS-Cov-2 protein or on the use of recombinant adenovirus vectors enabling the gene encoding the Spike protein to be introduced into our cells, these strategies make it possible to envisage the vaccination in a new light with tools that are more scalable than the vaccine strategies used so far. Faced with the appearance of new variants, which will gradually take precedence over the strain at the origin of the pandemic, these new strategies will allow a much faster update of vaccines to fight against these new variants, some of which may escape neutralization by vaccine antibodies. However, only a vaccination policy based on rapid and massive vaccination of the population but requiring a supply of sufficient doses could make it possible to combat the emergence of these variants. Indeed, the greater the number of infected individuals, the faster the virus multiplies, with an increased risk of the emergence of variants in these RNA viruses. This review will discuss SARS-CoV-2 pathophysiology and evolution approaches in altered transmission platforms and emphasize the different mutations and how they influence the virus characteristics. Also, this article summarizes the common vaccines and the implication of the mutations and genetic variety of SARS-CoV-2 on the COVID-19 biomedical arbitrations.

An update on angiotensin-converting enzyme 2 structure/functions, polymorphism, and duplicitous nature in the pathophysiology of coronavirus disease 2019: Implications for vascular and coagulation disease associated with severe acute respiratory syndrome coronavirus infection

It has been known for many years that the angiotensin-converting enzyme 2 (ACE2) is a cell surface enzyme involved in the regulation of blood pressure. More recently, it was proven that the severe acute respiratory syndrome coronavirus (SARS-CoV-2) interacts with ACE2 to enter susceptible human cells. This functional duality of ACE2 tends to explain why this molecule plays such an important role in the clinical manifestations of coronavirus disease 2019 (COVID-19). At the very start of the pandemic, a publication from our Institute (entitled "ACE2 receptor polymorphism: susceptibility to SARS-CoV-2, hypertension, multi-organ failure, and COVID-19 disease outcome"), was one of the first reviews linking COVID-19 to the duplicitous nature of ACE2. However, even given that COVID-19 pathophysiology may be driven by an imbalance in the renin-angiotensin system (RAS), we were still far from understanding the complexity of the mechanisms which are controlled by ACE2 in different cell types. To gain insight into the physiopathology of SARS-CoV-2 infection, it is essential to consider the polymorphism and expression levels of the ACE2 gene (including its alternative isoforms). Over the past 2 years, an impressive amount of new results have come to shed light on the role of ACE2 in the pathophysiology of COVID-19, requiring us to update our analysis. Genetic linkage studies have been reported that highlight a relationship between ACE2 genetic variants and the risk of developing hypertension. Currently, many research efforts are being undertaken to understand the links between ACE2 polymorphism and the severity of COVID-19. In this review, we update the state of knowledge on the polymorphism of ACE2 and its consequences on the susceptibility of individuals to SARS-CoV-2. We also discuss the link between the increase of angiotensin II levels among SARS-CoV-2-infected patients and the development of a cytokine storm associated microvascular injury and obstructive thrombo-inflammatory syndrome, which represent the primary causes of severe forms of COVID-19 and lethality. Finally, we summarize the therapeutic strategies aimed at preventing the severe forms of COVID-19 that target ACE2. Changing paradigms may help improve patients' therapy.

The new mechanism of cognitive decline induced by hypertension: High homocysteine-mediated aberrant DNA methylation

The prevalence and severity of hypertension-induced cognitive impairment increase with the prolonging of hypertension. The mechanisms of cognitive impairment induced by hypertension primarily include cerebral blood flow perfusion imbalance, white and gray matter injury with blood–brain barrier disruption, neuroinflammation and amyloid-beta deposition, genetic polymorphisms and variants, and instability of blood pressure. High homocysteine (HHcy) is an independent risk factor for hypertension that also increases the risk of developing early cognitive impairment. Homocysteine (Hcy) levels increase in patients with cognitive impairment induced by hypertension. This review summarizes a new mechanism whereby HHcy-mediated aberrant DNA methylation and exacerbate hypertension. It involves changes in Hcy-dependent DNA methylation products, such as methionine adenosyltransferase, DNA methyltransferases, S-adenosylmethionine, S-adenosylhomocysteine, and methylenetetrahydrofolate reductase (MTHFR). The mechanism also involves DNA methylation changes in the genes of hypertension patients, such as brain-derived neurotrophic factor, apolipoprotein E4, and estrogen receptor alpha, which contribute to learning, memory, and attention deficits. Studies have shown that methionine (Met) induces hypertension in mice. Moreover, DNA hypermethylation leads to cognitive behavioral changes alongside oligodendroglial and/or myelin deficits in Met-induced mice. Taken together, these studies demonstrate that DNA methylation regulates cognitive dysfunction in patients with hypertension. A better understanding of the function and mechanism underlying the effect of Hcy-dependent DNA methylation on hypertension-induced cognitive impairment will be valuable for early diagnosis, interventions, and prevention of further cognitive defects induced by hypertension.

Association of ACE1 I/D rs1799752 and ACE2 rs2285666 polymorphisms with the infection and severity of COVID-19: A meta-analysis

BACKGROUND

ACE1 I/D rs1799752 and ACE2 rs2285666 genetic polymorphisms could play a critical role in altering the clinical outcomes of SARS-CoV-2. The findings of previous studies remained inconclusive. This meta-analysis was performed to evaluate the association and provide a more reliable outcome.

METHODS

This study was completed following the updated recommendations of PRISMA using RevMan 5.4.1 statistical software.

RESULTS

A total of 11 studies with 950 severe cases and 1573 non-severe cases with COVID-19 infection were included. Pooled analysis showed that ACE1 I/D polymorphism was correlated with the severity of SARS-CoV-2 in the DD genotype and D allele for the fixed-effects model (OR:1.27 and OR:1.17). Besides, codominant 3, recessive, and allele models were associated with the severity of the fixed-effects model (OR:1.35, OR:1.37, and OR:1.20) in Caucasian ethnicity. ACE2 rs2285666 was linked with the severity in codominant 3 (OR:2.63, for both random- and fixed effects-models), overdominant (OR:1.97, for random-effects model and OR:1.97, for fixed effects-model), and recessive model (OR:0.41 for fixed- and random-effects model). Allele model of rs2285666 showed a significant association in the fixed-effects model (OR:1.61).

CONCLUSION

Our present meta-analysis suggests that ACE1 I/D rs1799752 and ACE2 rs2285666 variants may enhance the severity in SARS-CoV-2 infected patients. Future studies are warranted to verify our findings.

Angiotensin-converting enzyme 2 rs2285666 polymorphism and clinical parameters as the determinants of COVID-19 severity in Iranian population

Host genetic factors may be correlated with the severity of coronavirus disease 2019 (COVID-19). Angiotensin-converting enzyme 2 (ACE2) plays a vital role in viral cell entrance. The current study aimed to evaluate the association of ACE2 rs2285666 polymorphism and clinical parameters with COVID-19 mortality. The ACE2 rs2285666 polymorphism was genotyped using the polymerase chain reaction-restriction fragment length polymorphism in 556 recovered and 522 dead patients. In this study, the frequency of ACE2 rs2285666 CC was significantly higher than TT genotype in dead patients. The multivariate logistic regression analysis results showed that the higher levels of alanine aminotransferase, alkaline phosphatase, creatinine, erythrocyte sedimentation rate, and C-reactive protein and the low levels of uric acid, cholesterol, low density lipoprotein, 25-hydroxyvitamin D, real-time PCR Ct values, and ACE2 rs2285666 CC genotype were associated with increased mortality rates after COVID-19. In conclusion, our findings demonstrated a possible link between COVID-19 mortality, clinical parameters, and ACE2 rs2285666 CC. Further research is required to confirm these results.

Genetic polymorphisms of ACE1, ACE2, and TMPRSS2 associated with COVID-19 severity: A systematic review with meta-analysis

Novel coronavirus disease 2019 (COVID-19) poses a global threat, due to its fluctuating frequency and lethality. Published data revealed associations of COVID-19 susceptibility and severity with host genetic polymorphisms in renin-angiotensin-aldosterone system (RAAS)-related genes including angiotensin-converting enzyme (ACE)1, ACE2, and transmembrane protease (TMPRSS)2. However, the findings remain inconclusive. Accordingly, we aimed to clarify associations of genetic variants in those genes with COVID-19 susceptibility and severity using a systematic review with meta-analysis. From inception through 1 July 2021, a literature search was performed using PubMed, Scopus, Web of Science, and Cochrane Library databases. Allelic distributions for each polymorphism were calculated as pooled odds ratios (OR) with 95% confidence intervals (CI) to assess the strength of association. A total of 3333 COVID-19 patients and 5547 controls from 11 eligible studies were included. From a systematic review, ACE1 rs1799752, ACE1 rs4646994, ACE2 rs2285666, and TMPRSS2 rs12329760 were identified as common polymorphisms of RAAS-related genes. Meta-analysis showed a significant association between TMPRSS2 rs12329760 C-allele and an increased risk of developing severe COVID-19 (OR = 1.32, 95% CI: 1.01, 1.73). Likewise, additional meta-analyses uncovered that both ACE1 rs4646994 DD-genotype and ACE2 rs2285666 GG-genotype carriers had a significantly increased risk of developing severe COVID-19 (OR = 2.06, 95% CI: 1.45, 2.93; OR = 2.14, 95% CI: 1.26, 3.66; respectively). Genetic polymorphisms of ACE1 rs4646994 DD-genotype, ACE2 rs2285666 GG-genotype, and TMPRSS2 rs12329760 CC-genotype and C-allele may serve as predictive models of COVID-19 severity.

Receptor binding domain of SARS-CoV-2 from Wuhan strain to Omicron B.1.1.529 attributes increased affinity to variable structures of human ACE2

Background

COVID-19 is an infectious disease declared as a global pandemic caused by SARS-CoV-2 virus. Genomic changes in the receptor binding domain (RBD) region of SARS‐CoV‐2 led to an increased, infectivity in humans through interaction with the angiotensin-converting enzyme2 (ACE2) receptor. Simultaneously, the genetic variants in ACE2 provide an opportunity for SARS‐CoV‐2 infection and severity. We demonstrate the binding efficiencies of RBDs of SARS‐CoV‐2 strain with ACE2 variants of the human host.

Methodology

A Total of 615 SARS‐CoV‐2 genomes were retrieved from repository. Eighteen variations were identified contributing to structural changes in RBD that are distributed in 615 isolates. An analyses of 285 single nucleotide variances at the coding region of the ACE2 receptor showed 34 to be pathogenic. Homology models of 34 ACE2 and 18 RBD structures were constructed with 34 and 18 structural variants, respectively. Protein docking of 612 (34 *18) ACE2-RBD complexes showed variable affinities compared to wildtype Wuhan's and other SARS‐CoV‐2 RBDs, including Omicron B.1.1.529. Finally, molecular dynamic simulation was performed to determine the stability of the complexes.

Results

Among 612, the top 3 complexes showing least binding energy were selected. The ACE2 with rs961360700 variant showed the least binding energy (−895.2 Kcal/mol) on binding with the RBD of Phe160Ser variant compared to Wuhan's RBD complex. Interestingly, the binding energy of RBD of Omicron B.1.1.529 with ACE2 (rs961360700) structure showed least binding energy of −1010 Kcal/mol. Additionally, molecular dynamics showed structure stability for all the analysed complexes with the RMSD (0.22–0.26 nm), RMSF (0.11–0.13 nm), and Rg (2.53–2.56 nm).

Conclusion

In conclusion, our investigation highlights the clinical variants contributing to structural variants in ACE2 receptors that lead to efficient binding of SARS‐CoV‐2. Therefore, screening of these ACE2 polymorphisms will help detect COVID‐19 risk population so as to provide additional care and for safe management.

p53/NF-kB Balance in SARS-CoV-2 Infection: From OMICs, Genomics and Pharmacogenomics Insights to Tailored Therapeutic Perspectives (COVIDomics)

SARS-CoV-2 infection affects different organs and tissues, including the upper and lower airways, the lung, the gut, the olfactory system and the eye, which may represent one of the gates to the central nervous system. Key transcriptional factors, such as p53 and NF-kB and their reciprocal balance, are altered upon SARS-CoV-2 infection, as well as other key molecules such as the virus host cell entry mediator ACE2, member of the RAS-pathway. These changes are thought to play a central role in the impaired immune response, as well as in the massive cytokine release, the so-called cytokine storm that represents a hallmark of the most severe form of SARS-CoV-2 infection. Host genetics susceptibility is an additional key side to consider in a complex disease as COVID-19 characterized by such a wide range of clinical phenotypes. In this review, we underline some molecular mechanisms by which SARS-CoV-2 modulates p53 and NF-kB expression and activity in order to maximize viral replication into the host cells. We also face the RAS-pathway unbalance triggered by virus-ACE2 interaction to discuss potential pharmacological and pharmacogenomics approaches aimed at restoring p53/NF-kB and ACE1/ACE2 balance to counteract the most severe forms of SARS-CoV-2 infection.

The Race for ACE: Targeting Angiotensin-Converting Enzymes (ACE) in SARS-CoV-2 Infection

The SARS-CoV-2 virus is spreading around the world, and its clinical manifestation COVID-19 is challenging medical, economic, and social systems. With more and more scientific and social media reports on the COVID-19 pandemic appearing, differences in geographical presentations and clinical management occur. Since ACE2 (angiotensin-converting enzyme 2) is the gatekeeper receptor for the SARS-CoV-2 virus in the upper bronchial system, we here focus on the central role of the renin-angiotensin aldosterone system (RAAS) in the SARS-CoV-2 virus infection, the role of pharmacological RAAS inhibitors, and specific genetic aspects, i.e., single nucleotide polymorphisms (SNP) for the clinical outcome of COVID-19. We aimed to bring together clinical, epidemiological, molecular, and pathophysiological and pharmacological data/observations on cardiovascular aspects in the actual SARS-CoV-2 virus pandemic. In detail, we will report controversies about the Yin-Yan between ACE2 and ACE1 and potential implications for the treatment of hypertension, coronary artery disease, and heart failure. Here, we summarize the encouraging and dynamic global effort of multiple biomedical disciplines resulted in astonishing fight against COVID-19 targeting the renin-angiotensin-aldosterone system, yet the race for ACE just begun.

Clinical Utility of Amplification Refractory Mutation System-Based PCR and Mutation-Specific PCR for Precise and Rapid Genotyping of Angiotensin-Converting Enzyme 1 (ACE1-rs4646996 D>I) and Angiotensin-Converting Enzyme 2 (ACE2-rs4240157T>C) Gene Variations in Coronary Artery Disease and Their Strong Association with Its Disease Susceptibility and Progression

Background: Experimental clinical and research studies demonstrated that the renin−angiotensin system (RAS) affects the pathogenesis of atherosclerosis and the prognosis of coronary heart disease (CHD). The results show that ACE2 (angiotensin I-converting enzyme 2) might act as a protective protein for cardiovascular diseases; however, only a few studies in human populations have been carried out. The aim of this study was to develop, optimize, and validate a direct T-ARMS-based PCR assay for the precise and rapid genotyping of ACE1-rs4646996 D>I and ACE2-rs4240157T>C and study their association with coronary artery disease susceptibility and progression. Methodology: This study included 149 consecutive coronary artery disease patients and 150 healthy controls. We utilized T-ARMS for the precise and rapid genotyping of ACE2-rs4240157; rs4646994. Results: Our results indicated that the ACE1-rs4646996 D>I genotypes observed between CAD cases and controls were statistically significant (p < 0.008) and, similarly, the ACE2-rs4240157T>C genotypes observed were significant (p < 0.0001). Moreover, the frequency of the D allele (ACE1-D>I) and C allele (ACE2-rs4240157T>C) was found to be higher among CAD patients than the HC. Our results indicated that in the codominant model, the ACE2-ID genotype was strongly associated with increased CAD susceptibility in a codominant model with an OR of 2.37, (95%) CI = (1.023−5.504), and p < 0.04. Similarly, the ACE2-DD genotype was strongly associated with an increased CAD susceptibility with an OR of 3.48, (95%) CI = (1.49 to 8.117), and p < 0.003. Similarly, in allelic comparison, the D allele was strongly associated with CAD susceptibility with an OR of 1.59, (95%) CI = (1.12−2.24), and p < 0.003. Our results revealed that there was a significant correlation between ACE2-I/D genotypes and hypertension, T2D, and obesity (p < 0.05). The results of ACE2 rs4240157 genotyping indicated a strong association in the codominant model with an increased CAD susceptibility with an OR of 3.62, (95%) CI = (2.027 to 6.481), and p < 0.0001. Similarly, in a dominant inheritance model, a strong association is observed between the ACE2 rs4240157 (CT+CC) genotype with an OR of 6.34, (95%) CI = (3.741 to 10.749), and p < 0.0001. In allelic comparison, the T allele was strongly associated with CAD susceptibility with an OR of 5.56, (95% CI = (3.56 to 7.17), and p < 0.0001. Similarly, our results revealed that there was a significant association of the ACE2-rs4240157T>C genotypes with Triglycerides (mg/dL), HDL-C (mg/dL), total Cholesterol (mg/dL), and C-reactive protein (mg/L) in CAD. Conclusion: It was indicated that the ARMS technique and MS-PCR assay proved to be fast, accurate, and reliable for ACE2-rs4240157T>C and ACE1-rs4646996 D>I, respectively, and can be used as a potential molecular tool in the diagnosis of genetic diseases in undeveloped and developing countries—where there might be a shortage of medical resources and supplies. ACE1-I>D genotypes were strongly associated with T2D, hypertension, and obesity (p < 0.002). Besides the ACE2-rs4240157 CT heterozygosity genotype, the T allele was strongly associated with CAD susceptibility. Future longitudinal studies in different ethnic populations with larger sample sizes are recommended to validate these findings

Systematic review and meta-analysis of candidate gene association studies of benign prostate hyperplasia

BACKGROUND

Benign prostate hyperplasia (BPH) is the most common urological problem in elderly males. Recent studies have reported polymorphism in various metabolic genes in BPH. However, their association with the susceptibility of BPH is still inconsistent. Here, we systematically reviewed and performed a meta-analysis of CYP17, VDR, and ACE genes to determine their precise association with the risk of BPH.

METHODS

A comprehensive literature search for published studies on candidate gene associations involving vitamin D receptor (VDR), angiotensin-converting enzyme (ACE), and CYP17 genes with the risk of BPH was done up to April 2020 in PubMed, Scopus, Cochrane Central Register of Controlled Trials (CENTRAL), and Google Scholar databases. Fixed/random effects models were used to estimate the odd's ratio (OR) and 95% confidence intervals (CIs). Begg's funnel plot was used to assess the potential for publication bias.

RESULTS

We found a total of 23 studies containing 3461 cases and 3833 controls for these gene polymorphisms. A significant association of ACE gene polymorphism was observed under the recessive (II vs. ID + DD) model for BPH susceptibility compared to control subjects (overall OR = 1.67, 95% CI = 1.03-2.73). Similar trends were observed for ACE gene polymorphism in Caucasian (OR = 6.18, 95% CI = 1.38-27.68) and Asian (OR = 1.42, 95% CI = 0.99-2.03) populations under study. No significant association was observed in VDR and CYP17 gene polymorphisms in any dominant or recessive models.

CONCLUSION

Significant OR demonstrated the implication of ACE gene polymorphism in the proliferation of prostate tissue, which in turn is associated with BPH susceptibility. However, prospective studies at large scale and sample size are needed to confirm the current findings.

Investigation of angiotensin-1 converting enzyme 2 gene (G8790A) polymorphism in patients of type 2 diabetes mellitus with diabetic nephropathy in Pakistani population

Background

Type 2 diabetes mellitus is a multifactorial disease that escalates the risk of other associated complications such as diabetic neuropathy, retinopathy, and nephropathy. Diabetic nephropathy is a microvascular condition that leads to end-stage renal disease (ESRD). There are several genes involved in disease development and it is a challenging task to investigate all of these. Nonetheless, identifying individual gene roles can assist in evaluating the combinatorial effects with other genes. Angiotensin-1 converting enzyme 2 (ACE2), is the key regulator of blood pressure in the Renin-Angiotensin-Aldosterone System that hydrolyzes angiotensin II (vasoconstrictor) into angiotensin 1–7 (vasodilator). The association of different variants of the ACE2 with the risk of type 2 diabetes mellitus has been determined in various populations with susceptibility to other complications. This study was aimed to investigate the association of Angiotensin-1 converting enzyme 2 polymorphism, G8790A, with the increased risk of type 2 diabetes mellitus (T2DM) development with the complication of diabetic nephropathy (DN) in the Pakistani population.

Methods

In this case-control study, a total of 100 healthy controls and 100 patients of type 2 diabetes mellitus aged > 40 years, having disease duration ≥ 10 years were compared. The G8790A polymorphism in ACE2 was analyzed by allele-specific polymerase chain reaction (AS-PCR). The urinary albumin excretion (UAE), urinary creatinine, and albumin to creatinine ratios (ACR) were determined to assess renal function status. Pearson bivariate correlation coefficients were calculated to investigate the relationship among all the parameters. Crude and adjusted odds ratios were found to determine any risk association between ACE2 G8790A polymorphisms and disease development. The p-values < 0.05 were considered significant.

Results

A homogeneity was obtained regarding the distribution of data by sex, BMI, diastolic blood pressure, pulse rate and urinary creatinine levels between case and control groups. The ACR showed a significant correlation with UAE (r = 0.524, p = 0.001), urinary creatinine (r = -0.375, p = 0.001) and random blood sugar levels (r = 0.323, p = 0.005) with the complication of diabetic nephropathy in T2DM patient. Females with the AA genotype had a 10-fold increased risk for the development of type 2 Diabetes (OR = 9.5 [95% CI = 2.00–21.63] p<0.002). Males having A allele showed a significant association for susceptibility of type 2 Diabetes (OR = 3.807 [95% CI = 1.657–8.747] p<0.002). However, none of the genotypes or alleles revealed an association for diabetic nephropathy in male and female patients. Urinary ACR was also found to be positively correlated with UAE (r = 0.642 p = 0.001 & 0.524, p = 0.001) and random blood sugar levels (r = 0.302, p = 0.002 & r = 0.323, p = 0.005) in T2DM and T2DM+DN groups, respectively.

Conclusion

The study finding indicated that female AG/AA genotype and male A genotype of G8790A polymorphism in the ACE2 gene were associated with type 2 diabetes mellitus as a genetic risk factor but are not associated with diabetic nephropathy in the Pakistani population.

Pharmacogenomics Informs Cardiovascular Pharmacotherapy

Precision medicine exemplifies the emergence of personalized treatment options which may benefit specific patient populations based upon their genetic makeup. Application of pharmacogenomics requires an understanding of how genetic variations impact pharmacokinetic and pharmacodynamic properties. This particular approach in pharmacotherapy is helpful because it can assist in and improve clinical decisions. Application of pharmacogenomics to cardiovascular pharmacotherapy provides for the ability of the medical provider to gain critical knowledge on a patient's response to various treatment options and risk of side effects.

Differential expression in humans of the viral entry receptor ACE2 compared with the short deltaACE2 isoform lacking SARS-CoV-2 binding sites

ACE2 is a membrane protein that regulates the cardiovascular system. Additionally, ACE2 acts as a receptor for host cell infection by human coronaviruses, including SARS-CoV-2 that emerged as the cause of the on-going COVID-19 pandemic and has brought unprecedented burden to economy and health. ACE2 binds the spike protein of SARS-CoV-2 with high affinity and shows little variation in amino acid sequence meaning natural resistance is rare. The discovery of a novel short ACE2 isoform (deltaACE2) provides evidence for inter-individual differences in SARS-CoV-2 susceptibility and severity, and likelihood of developing subsequent 'Long COVID'. Critically, deltaACE2 loses SARS-CoV-2 spike protein binding sites in the extracellular domain, and is predicted to confer reduced susceptibility to viral infection. We aimed to assess the differential expression of full-length ACE2 versus deltaACE2 in a panel of human tissues (kidney, heart, lung, and liver) that are implicated in COVID-19, and confirm ACE2 protein in these tissues. Using dual antibody staining, we show that deltaACE2 localises, and is enriched, in lung airway epithelia and bile duct epithelia in the liver. Finally, we also confirm that a fluorescently tagged SARS-CoV-2 spike protein monomer shows low binding at lung and bile duct epithelia where dACE2 is enriched.

Strong Association of Angiotensin Converting Enzyme-2 Gene Insertion/Deletion Polymorphism with Susceptibility to SARS-CoV-2, Hypertension, Coronary Artery Disease and COVID-19 Disease Mortality

BACKGROUND

The ongoing outbreak of SARS-CoV-2 represents a significant challenge to international health. Several reports have highlighted the importance of ACE2 on the pathogenesis of COVID-19. The spike protein of SARS-CoV-2 efficiently binds to the angiotensin-converting enzyme 2 (ACE2) receptors and facilitates virus entry into the host cell. In the present study, we hypothesize that a functional insertion/deletion polymorphism-rs4646994 I/D and rs4240157 T > C in the ACE gene could be associated with SARS-CoV-2 infection and mortality.

METHODOLOGY

This study included 117 consecutive COVID-19 patients and 150 age matched healthy controls (ACE2-rs4646994 I/D) and 100 age matched healthy controls with ACE2 rs4240157 T > C. We used Mutation specific PCR (MSP) for ACE2-rs4646994 I/D genotyping and amplification refractory mutation system (ARMS-PCR) for ACE2 rs4240157 T > C genotyping.

RESULTS

Results indicated that there were significant differences in the genotype distributions of ACE2-rs4646994 I/D polymorphisms (p < 0.030) and ACE2 rs4240157 T > C between COVID-19 patients and controls (p-values < 0.05). Higher frequency of DD genotype (48.71%) and D allele (0.67) was reported in COVID-19 patients than controls. Our results showed that the ACE2-DD genotype was strongly associated with increased COVID-19 severity (OR 2.37 (95%) CI = (1.19-4.70), RR = 1.39 (1.09-1.77), p < 0.013) and also a strong association was seen with ACE2-ID genotype with COVID-19 severity (OR 2.20 (95%) CI = (1.08-4.46), p < 0.020) in the codominant model. In allelic comparison, the D allele was strongly associated with COVID-19 severity (OR 1.58 (95% CI) (1.11-2.27), RR 1.21 (1.05-1.41) p < 0.010). A significant correlation of ACE2-I/D genotypes was reported with Age (p < 0.035), T2D (p < 0.0013), hypertension (p < 0.0031) and coronary artery disease (p < 0.0001). Our results indicated ACE2-DD genotype was strongly associated with increased COVID-19 mortality (OR 8.25 (95%) CI = (2.40 to 28.34), p < 0.008) and also ACE2-DD + DI genotype was strongly associated with increased COVID-19 mortality with OR 4.74 (95%) CI = (1.5214 to 14.7915), p < 0.007. A significant correlation was reported between COVID-19 patients and age matched controls (p < 0.0007). Higher frequency of heterozygosity TC (40%) followed by ACE2-CC genotype (24.78%) was reported among COVID-19 patients. Using multivariate analysis, ACE2-CT genotype was strong associated with SARS-CoV-2 severity with an OR 2.18 (95% CI) (1.92-3.99), p < 0.010 and also ACE2-CC genotype was linked with COVID-19 severity with an OR 2.66 (95% CI) (1.53-4.62), p < 0.005. A significant correlation of ACE2-T > C genotypes was reported with gender (p < 0.04), T2D (p < 0.035). ACE2-CC genotype was strongly associated with increased COVID-19 mortality OR 3.66 (95%) CI = (1.34 to 9.97), p < 0.011 and also ACE2-C allele was associated with COVID-19 mortality OR 2, 01 (1.1761-3.45), p < 0.010.

CONCLUSIONS

It is concluded that ACE-DD genotype and D allele was strongly associated with increased COVID-19 patient severity. In addition, ACE I/D polymorphism were strongly associated with advanced age, diabetes and ischemic heart disease in COVID-19 patients whereas ACE-II genotype was a protective factor against the development of severe COVID-19. ACE2-DD genotype was strongly associated with increased COVID-19 mortality. Additionally, ACE2-CC and CT genotypes were strongly associated with COVID-19 severity. Therefore, our study might be useful for identifying the susceptible population groups for targeted interventions and for making relevant public health policy decisions.

Analysis of the association of polymorphisms of genes markers functions of endothelium and vascular-plate hemostasis with development of diabetic foot syndrome

The aim. To study the prevalence of various combinations of polymorphic variants of genes markers of endothelial function and vascular-platelet hemostasis in the development of diabetic foot syndrome.Materials and methods. In 198 patients with uncomplicated diabetes mellitus and 199 patients with diabetic foot syndrome, the frequency of polymorphic variants of the NOS 786C>T, END1 Lys198Asn, ITGB3 1565T>C (Leu33Pro), F5 1691G>A, F2 20210G>A, MMP9 8202A>G, MTHFR 1298A>C, VEGFA-634C>G genes was studied. Using binary logistic regression analysis, the relationship of various combinations of polymorphisms of the studied genes with the development of diabetic foot was assessed.Results. In diabetic foot syndrome, the most significant contribution is made by the combination of polymorphic variants of the ITGB3 1565T>C (Leu33Pro) and MTHFR 1298A>C genes. With the development of this complication of diabetes mellitus, a combination of the 1565 TC polymorphism of gene ITGB3 and the 1298AA polymorphism of gene MTHFR is 2.1 times more common. The association of the 1565TT polymorphism of gene ITGB3 and the 1298AC polymorphism of gene MTHFR is 2 times more common in diabetes mellitus without complications.Conclusion. The combination of the 1565TС polymorphism of gene ITGB3 and the 1298АА polymorphism of gene MTHFR is associated with the risk of developing a diabetic foot and increases the risk of developing this complication by 2.4 times. The presence of a combination of the 1565TT polymorphisms of gene ITGB3 and the 1298AC polymorphism of gene MTHFR is more common in uncomplicated diabetes mellitus, which suggests its protective effect against the development of diabetic foot syndrome.

ACE2 polymorphism and susceptibility for SARS-CoV-2 infection and severity of COVID-19

OBJECTIVES

The RNA virus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for coronavirus disease 2019 (COVID-19). Cell entry is mediated by the human angiotensin-converting enzyme II (ACE2). ACE2 and its close homolog angiotensin-converting enzyme I (ACE) are currently discussed candidate genes, in which single-nucleotide polymorphisms (SNPs) could alter binding or entry of SARS-CoV-2 and enhance tissue damage in the lung or other organs. This could increase the susceptibility for SARS-CoV-2 infection and the severity of COVID-19.

PATIENTS AND METHODS

We performed genotyping of SNPs in the genes ACE2 and ACE in 297 SARS-CoV-2-positive and 253 SARS-CoV-2-negative tested patients. We analyzed the association of the SNPs with susceptibility for SARS-CoV-2 infection and the severity of COVID-19.

RESULTS

SARS-CoV-2-positive and SARS-CoV-2-negative patients did not differ regarding demographics and clinical characteristics. For ACE2 rs2285666, the GG genotype or G-allele was significantly associated with an almost two-fold increased SARS-CoV-2 infection risk and a three-fold increased risk to develop serious disease or COVID-19 fatality. In contrast, the ACE polymorphism was not related to infection risk or severity of disease. In a multivariable analysis, the ACE2 rs2285666 G-allele remained as an independent risk factor for serious disease besides the known risk factors male gender and cardiovascular disease.

CONCLUSIONS

In summary, our report appears to be the first showing that a common ACE2 polymorphism impacts the risk for SARS-CoV-2 infection and the course of COVID-19 independently from previously described risk factors.

COVID-19: Pulmonary and Extra Pulmonary Manifestations

Introduction: The coronavirus disease-2019 (COVID-19) pandemic has been the most significant event in 2020, with ~86.8 million cases and 1.88 million deaths worldwide. It is a highly infectious disease, wherein the virus (severe acute respiratory syndrome coronavirus 2) rapidly multiplies and spreads to all parts of the body. Therefore, COVID-19 is not only respiratory disease but also a multisystem disease. Many people, including physicians, incorrectly believe that the disease affects only the respiratory tract. In this study, we aimed to describe COVID-19 manifestations and the underlying pathophysiology to provide the readers with a better understanding of this disease to achieve good management and to control the spread of this disease. Methods: Secondary data were obtained from PubMed, Google Scholar, and Scopus databases. The keywords used for the search were as follows: COVID-19, COVID-19 pulmonary manifestations, COVID-19 extra pulmonary manifestations, and pathophysiology of COVID-19. We collected secondary data from systemic reviews, metaanalyses, case series, and case reports in the form of public data that was published on websites of the government, medical corporations, medical peer-reviewed journals, and medical academies, all of which were indexed in PubMed, Google Scholar, or Scopus. Our questions were as follows: Is COVID-19 a respiratory disease only? and What are the extrapulmonary manifestations of COVID-19? Results: From our data, we found that a patient with COVID-19 may be either asymptomatic or symptomatic. Symptomatic cases may have either pulmonary or extrapulmonary manifestations. Pulmonary manifestations occur as mild, moderate, or severe cases. In mild and moderate cases, extrapulmonary manifestations such as gastroenteritis, fever, or vomiting may present alone. Some of these cases may be missed for diagnosis, and the patient may receive symptomatic treatment without a COVID-19 diagnosis, leading to increased spread of the infection. Extrapulmonary manifestations may occur in severe and critical cases as complications of severe infections (high viral overload) or the cytokine storm, such as in acute kidney injury (AKI), heart failure (HF), and venous thromboembolic (VTE) manifestation. Conclusion: COVID-19 is not a respiratory disease alone; rather, it is a multisystem disease. Pulmonary and extrapulmonary manifestations should be considered for early diagnosis and to control the spread of the infection.

Host variations in SARS-CoV-2 infection

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the zoonotic pathogen that causes the "Coronavirus Disease of 2019 (COVID-19)", and COVID-19 itself is yet to be thoroughly understood. Both the disease as well as the mechanisms by which the host interacts with the SARS-CoV-2 have not been fully enlightened. The epidemiological factors -e.g. age, sex, race-, the polymorphisms of the host proteins, the blood types and individual differences have all been in discussions about affecting the progression and the course of COVID-19 both individually and collectively, as their effects are mostly interwoven. We focused mainly on the effect of polymorphic variants of the host proteins that have been shown to take part in and/or affect the pathogenesis of COVID-19. Additionally, how the procedures of diagnosing and treating COVID-19 are affected by these variants and what possible changes can be implemented are the other questions, which are sought to be answered.

A Computational Approach to Evaluate the Combined Effect of SARS-CoV-2 RBD Mutations and ACE2 Receptor Genetic Variants on Infectivity: The COVID-19 Host-Pathogen Nexus

SARS-CoV-2 infectivity is largely determined by the virus Spike protein binding to the ACE2 receptor. Meanwhile, marked infection rate differences were reported between populations and individuals. To understand the disease dynamic, we developed a computational approach to study the implications of both SARS-CoV-2 RBD mutations and ACE2 polymorphism on the stability of the virus-receptor complex. We used the 6LZG PDB RBD/ACE2 3D model, the mCSM platform, the LigPlot+ and PyMol software to analyze the data on SARS-CoV-2 mutations and ACE variants retrieved from GISAID and Ensembl/GnomAD repository. We observed that out of 351 RBD point mutations, 83% destabilizes the complex according to free energy (ΔΔG) differences. We also spotted variations in the patterns of polar and hydrophobic interactions between the mutations occurring in 15 out of 18 contact residues. Similarly, comparison of the effect on the complex stability of different ACE2 variants showed that the pattern of molecular interactions and the complex stability varies also according to ACE2 polymorphism. We infer that it is important to consider both ACE2 variants and circulating SARS-CoV-2 RBD mutations to assess the stability of the virus-receptor association and evaluate infectivity. This approach might offers a good molecular ground to mitigate the virus spreading.

Association between endothelial nitric oxide synthase and the renin-angiotensin-aldosterone system polymorphisms, blood pressure and training status in normotensive/pre-hypertension and hypertensive older adults: a pilot study

Introduction:Variations in blood pressure (BP) are, in part, genetically determined and some polymorphisms of renin-angiotensin- aldosterone system (RAAS) and synthase of endothelial nitric oxide (eNOS) have been related to hypertension (HT). Conversely, physical exercise is considered a non-pharmacological tool for HT control, treatment, and prevention.Objective: The purpose of this study is to investigate the relationship between eNOS and RAAS polymorphisms, their epistatic interaction, and the respective humoral factors in the BP control in normotensive/pre-hypertension and hypertensive older adults and how this relationship can be modulated by training status (TS) level.Methods:A total of 155 older adults (66.94 ± 6.83 years old) performed the following evaluations: AAHPERD battery test to determine the general functional fitness index (GFFI), systolic and diastolic blood pressure (SBP and DBP), blood collection for DNA extraction, analysis of eNOS gene polymorphisms rs2070744; rs61722009 and rs1799983 and RAAS polymorphisms rs699; rs1799752 and rs5186, and quantification of ACE activity (Fluorimetric Assay) and nitrite concentration (Chemiluminescence Method).Results and Conclusion:Good TS level appears to exert greater influence on SBP for G2 and G3 (G1: 125.79 ± 14.03/ G2: 119.91 ± 11.72^/G3: 119.71 ± 10.85) and on NO₂ for G3 (G1: 0.42 ± 0.25/ G2: 0.54 ± 0.45/ G3: 0.71 ± 0.52). No associations were observed between eNOS and RAAS polymorphisms, but the epistasis was identified between eNOS polymorphism, rs2070744, and RAAS polymorphism, rs699, revealing a statistically significant interaction (p = .0235) with training score of 0.63, a training test accuracy of 0.61 and a cross-validation consistency of 10/10. This result suggests an increased risk of hypertension.

Severity of COVID-19 infection in ACEI/ARB users in specialty hospitals: A retrospective cohort study

BACKGROUND

The uncertainty about COVID-19 outcomes in angiotensin-converting enzyme inhibitors (ACEI)/angiotensin receptor blockers (ARB) users continues with contradictory findings. This study aimed to determine the effect of ACEI/ARB use in patients with severe COVID-19.

METHODS

This retrospective cohort study was done in two Saudi public specialty hospitals designated as COVID-19 referral facilities. We included 354 patients with a confirmed diagnosis of COVID-19 between April and June 2020, of which 146 were ACEI/ARB users and 208 were non-ACEI/ARB users. Controlling for confounders, we conducted multivariate logistic regression and sensitivity analyses using propensity score matching (PSM) and Inverse propensity score weighting (IPSW) for high-risk patient subsets.

RESULTS

Compared to non-ACEI/ARB users, ACEI/ARB users had an eight-fold higher risk of developing critical or severe COVID-19 (OR = 8.25, 95%CI = 3.32-20.53); a nearly 7-fold higher risk of intensive care unit (ICU) admission (OR = 6.76, 95%CI = 2.88-15.89) and a nearly 5-fold higher risk of requiring noninvasive ventilation (OR = 4.77,95%CI = 2.15-10.55). Patients with diabetes, hypertension, and/or renal disease had a five-fold higher risk of severe COVID-19 disease (OR = 5.40,95%CI = 2.0-14.54]. These results were confirmed in the PSM and IPSW analyses.

CONCLUSION

In general, but especially among patients with hypertension, diabetes, and/or renal disease, ACEI/ARB use is associated with a significantly higher risk of severe or critical COVID-19 disease, and ICU care.

The use of mechanistic reasoning in assessing coronavirus interventions

RATIONALE

Evidence-based medicine (EBM), the dominant approach to assessing the effectiveness of clinical and public health interventions, focuses on the results of association studies. EBM+ is a development of EBM that systematically considers mechanistic studies alongside association studies.

AIMS AND OBJECTIVES

To explore examples of the importance of mechanistic evidence to coronavirus research.

METHODS

We have reviewed the mechanistic evidence in four major areas that are relevant to the management of COVID-19.

RESULTS AND CONCLUSIONS

(a) Assessment of combination therapy for MERS highlights the need for systematic assessment of mechanistic evidence. (b) That hypertension is a risk factor for severe disease in the case of SARS-CoV-2 suggests that altering hypertension treatment might alleviate disease, but the mechanisms are complex, and it is essential to consider and evaluate multiple mechanistic hypotheses. (c) Confidence that public health interventions will be effective requires a detailed assessment of social and psychological components of the mechanisms of their action, in addition to mechanisms of disease. (d) In particular, if vaccination programmes are to be effective, they must be carefully tailored to the social context; again, mechanistic evidence is crucial. We conclude that coronavirus research is best situated within the EBM+ evaluation framework.

SARS CoV2 infection _The longevity study perspectives

Like other infectious diseases, COVID-19 shows a clinical outcome enormously variable, ranging from asymptomatic to lethal. In Italy, like in other countries, old male individuals, with one or more comorbidity, are the most susceptible group, and show, consequently, the highest mortality, and morbidity, including lethal respiratory distress syndrome, as the most common complication. In addition, another extraordinary peculiarity, that is a surprising resistance to COVID-19, characterizes some Italian nonagenarians/centenarians. Despite having the typical COVID-19 signs and/or symptoms, such exceptional individuals show a surprising tendency to recover from illness and complications. On the other hand, long-lived people have an optimal performance of immune system related to an overexpression of anti-inflammatory variants in immune/inflammatory genes, as demonstrated by our and other groups. Consequently, we suggest long-lived people as an optimal model for detecting genetic profiles associated with the susceptibility and/or protection to COVID-19, to utilize as potential pharmacological targets for preventing or reducing viral infection in more vulnerable individuals.

Disparities in COVID-19 severities and casualties across ethnic groups around the globe and patterns of ACE2 and PIR variants

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) mediated Coronavirus disease-19 (COVID-19) has affected millions of individuals around all corners of the globe. Symptoms and severities of infection with this highly contagious virus vary among individuals and there is disparity in the number of COVID-19-related casualties across different ethnic groups. The primary receptor for SARS-CoV-2 entry into the host cells is angiotensin-converting enzyme 2 (ACE2). Certain variants of ACE2 are known to be associated with COVID-19 comorbidities such as hypertension, cardiovascular complications, diabetes, chronic lung disease, etc. In this study, we looked into the geographic distribution of disease-associated variants of ACE2 as well as closely located PIR gene to explore any possible correlation with the disparities in COVID-19 severities and casualties across ethnic groups. Frequencies of the ACE2 variants associated with COVID-19 comorbidities are higher in the European and the admixed American populations. These variants are also present with stronger pairwise linkage disequilibrium (LD) in the European and the admixed American populations. On the other hand, the variants with protective role are more prevalent in the East and the South Asian populations. Strong pairwise LD exists among the activity modifying (modifier) variants of the PIR and ACE2 genes only in the European super-population. Absence of these PIR variants in the South Asian population may contribute to the overall lower COVID-19 case fatality rates (CFR) despite the dense population in this region.

Investigating the ACE2 polymorphisms in COVID-19 susceptibility: An in silico analysis

Background

Novel coronavirus (SARS‐CoV‐2) became an epidemic disease and lead to a pneumonia outbreak first in December 2019 in Wuhan, China. The symptoms related to coronavirus disease‐19 (COVID‐19) were different ranging from mild to severe lung injury and multi‐organ failure symptoms, eventually leading to death, especially in older patients with other co‐morbidities. The receptor of this virus in the human cell is angiotensin‐converting enzyme 2 (ACE2).

Methods

In this paper, we aimed to perform an in silico analysis of the frequently studied variants of the ACE2 gene and determine the effects of the variants in mRNA secondary structure and binding affinity of cellular factors. Fourteen single‐nucleotide polymorphisms were selected based on previous studies and investigated.

Results

All of the variants were analyzed in the RNAsnp database and three revealed a significant p‐value. The spliceAid2 database prediction showed that 7 out of 14 SNPs caused an alteration in a way that only the wild or mutated form was able to bind to proteins. The latter database also reported that three SNPs produces a dual form in which different specific proteins can bind to the sequence in a specific form (either wild or mutated form).

Conclusion

Altogether, these estimations revealed the potential of variants in manipulation of the final stable form of ACE2 that can lead to different COVID‐19 susceptibility.

SARS-CoV-2 Entry Related Viral and Host Genetic Variations: Implications on COVID-19 Severity, Immune Escape, and Infectivity

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has evolved to display particular patterns of genetic diversity in the genome across geographical regions. These variations in the virus and genetic variation in human populations can determine virus transmissibility and coronavirus disease 2019 (COVID-19) severity. Genetic variations and immune differences in human populations could be the driving forces in viral evolution. Recently emerged SARS-CoV-2 variants show several mutations at the receptor binding domain in the spike (S) glycoprotein and contribute to immune escape and enhanced binding with angiotensin 1-converting enzyme 2 (ACE2). Since ACE2 and transmembrane protease serine 2 (TMPRSS2) play important roles in SARS-CoV-2 entry into the cell, genetic variation in these host entry-related proteins may be a driving force for positive selection in the SARS-CoV-2 S glycoprotein. Dendritic or liver/lymph cell-specific intercellular adhesion molecule (ICAM)-3-grabbing non-integrin is also known to play vital roles in several pathogens. Genetic variations of these host proteins may affect the susceptibility to SARS-CoV-2. This review summarizes the latest research to describe the impacts of genetic variation in the viral S glycoprotein and critical host proteins and aims to provide better insights for understanding transmission and pathogenesis and more broadly for developing vaccine/antiviral drugs and precision medicine strategies, especially for high risk populations with genetic risk variants.

Perspectives and Challenges in the Fight Against COVID-19: The Role of Genetic Variability

In the last year, the advent of the COVID-19 pandemic brought a new consideration for the multidisciplinary sciences. The unknown mechanisms of infection used by SARS-CoV-2 and the absence of effective antiviral pharmacological therapy, diagnosis methods, and vaccines evoked scientific efforts on the COVID-19 outcome. In general, COVID-19 clinical features are a result of local and systemic inflammatory processes that are enhanced by some preexistent comorbidities, such as diabetes, obesity, cardiovascular, and pulmonary diseases, and biological factors, like gender and age. However, the discrepancies in COVID-19 clinical signs observed among those patients lead to investigations about the critical factors that deeply influence disease severity and death. Herein, we present the viral infection mechanisms and its consequences after blocking the angiotensin-converting enzyme 2 (ACE2) axis in different tissues and the progression of inflammatory and immunological reactions, especially the influence of genetic features on those differential clinical responses. Furthermore, we discuss the role of genotype as an essential indicator of COVID-19 susceptibility, considering the expression profiles, polymorphisms, gene identification, and epigenetic modifications of viral entry factors and their recognition, as well as the infection effects on cell signaling molecule expression, which amplifies disease severity.

An Energy-Resolved Optical Non-invasive Device Detects Essential Electrolyte Balance in Humans at Point-of-Care

Regular monitoring of electrolyte balance is essential for patients suffering from chronic kidney disease (CKD), particularly those undergoing dialysis. In the context of the recent COVID-19 pandemic, more severe forms of infection are observed in elderly individuals and patients having co-morbidities like CKD. The repeated blood tests for the monitoring of electrolyte balance predispose them not only to COVID-19 but also other to hospital-acquired infections (HAI). Therefore, a non-invasive method for easy detection of essential electrolyte (K⁺ and Na⁺) levels is urgently needed. In this study, we developed an optical emission spectroscopy-based non-invasive device for simultaneous monitoring of salivary Na⁺ and K⁺ levels in a fast and reliable way. The device consisted of a closed spark chamber, micro-spectrometer, high voltage spark generator, electronic circuits, optical fiber, and an indigenously developed software based on the LabVIEW platform. The optical emission originating from the biological sample (i.e., saliva) due to recombination of ions energized by impingement of electrons returning from high voltage spark provides necessary information about the concentration of electrolytes. A small-scale clinical trial on 30 healthy human subjects shows the potential of the indigenously developed device in determining salivary Na⁺ and K⁺ concentration. The low-cost, portable, point-of-care device requires only 2 mL of sample, and can simultaneously measure 1.0-190.0 mM Na⁺, and 1.0-270.9 mM K⁺ . To our understanding, the present work will find its relevance in combating COVID-19 morbidities, along with regular CKD patient-care.

Mutational Spectrum of LDLR and PCSK9 Genes Identified in Iranian Patients With Premature Coronary Artery Disease and Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is a common, yet underdiagnosed, genetic disorder characterized by lifelong elevated low-density lipoprotein cholesterol levels, which can increase the risk of early-onset coronary artery disease (CAD). In the present study, we screened the nucleotide variations of the LDLR and PCSK9 genes, as well as a part of the APOB gene, in Iranian patients with FH and premature CAD to find the genetic cause of the disorder. Fifteen unrelated individuals with a clinical diagnosis of FH and premature CAD were recruited. Direct DNA sequencing was applied to screen the whole coding exons and exon-intron boundaries of the LDLR and PCSK9 genes and the main parts of their introns, together with exon 26 of the APOB gene. The pathogenicity of the identified mutations was investigated via either segregation analyses in the family or in silico predictive software. Six different point mutations (p.Cys148Tyr, p.Cys216Tyr, p.Cys302Trp, p.Cys338Trp, p.Leu479Gln, and p.G593Afs∗72) in LDLR and a double mutation (p.Asp172His and p.Ala53Val) in both LDLR and PCSK9 genes were identified in seven families with clinically diagnosed FH (43%), whereas no pathogenic mutations were found in eight families with clinically diagnosed FH. This study is the first to identify 1 pathogenic mutation in the LDLR gene (c.1014C > G [p.Cys338Trp]) and to cosegregate it from the affected individual in the family. No mutations were found in the APOB gene, whereas several silent mutations/polymorphisms were identified in the LDLR and PCSK9 genes. Genetic testing and reports on nucleotide alterations in the Iranian population are still limited. Our findings not only further confirm the significant role of FH in the incidence of premature CAD but also enlarge the spectrum of LDLR and PCSK9 variations and exhibit the heterogeneity of FH in Iranians. In patients with no mutation in the examined genes, the disease could be begotten either by a polygenic cause or by gene defects occurring in other related genes and regions not targeted in this study.

ACE2 Nascence, trafficking, and SARS-CoV-2 pathogenesis: the saga continues

With the emergence of the novel coronavirus SARS-CoV-2 since December 2019, more than 65 million cases have been reported worldwide. This virus has shown high infectivity and severe symptoms in some cases, leading to over 1.5 million deaths globally. Despite the collaborative and concerted research efforts that have been made, no effective medication for COVID-19 (coronavirus disease-2019) is currently available. SARS-CoV-2 uses the angiotensin-converting enzyme 2 (ACE2) as an initial mediator for viral attachment and host cell invasion. ACE2 is widely distributed in the human tissues including the cell surface of lung cells which represent the primary site of the infection. Inhibiting or reducing cell surface availability of ACE2 represents a promising therapy for tackling COVID-19. In this context, most ACE2-based therapeutic strategies have aimed to tackle the virus through the use of angiotensin-converting enzyme (ACE) inhibitors or neutralizing the virus by exogenous administration of ACE2, which does not directly aim to reduce its membrane availability. However, through this review, we present a different perspective focusing on the subcellular localization and trafficking of ACE2. Membrane targeting of ACE2, and shedding and cellular trafficking pathways including the internalization are not well elucidated in literature. Therefore, we hereby present an overview of the fate of newly synthesized ACE2, its post translational modifications, and what is known of its trafficking pathways. In addition, we highlight the possibility that some of the identified ACE2 missense variants might affect its trafficking efficiency and localization and hence may explain some of the observed variable severity of SARS-CoV-2 infections. Moreover, an extensive understanding of these processes is necessarily required to evaluate the potential use of ACE2 as a credible therapeutic target.

A Novel PCR Method for Detecting ACE Gene Insertion/Deletion Polymorphisms and its Clinical Application

Background

Angiotensin-converting enzyme (ACE) plays a major role in blood pressure regulation and cardiovascular homeostasis. The wide distribution and multifunctional properties of ACE suggest it’s involvement in various pathophysiological conditions.

Results

In this study, a novel visual detection method for ACE I/D polymorphisms was designed by integrating direct PCR without the need for DNA extraction using gold magnetic nanoparticles (GMNPs)-based lateral flow assay (LFA) biosensor. The entire detection procedure could enable the genotyping of clinical samples in about 80 min. The detection limit was 0.75 ng and results could be obtained in 5 min using the LFA device. Three hundred peripheral blood samples were analyzed using the direct PCR-LFA system and then verified by sequencing to determine accuracy and repeatability. A clinical preliminary study was then performed to analyze a total of 633 clinical samples.

Conclusions

After grouping based on age, we found a significant difference between the genotypes and the age of patients in the CHD group. The introduction of this method into clinical practice may be helpful for the diagnosis of diseases caused by large fragment gene insertions/deletions.

Evaluation of the effect of serum cystatin-C and ACE I/D and ACE G2350A polymorphisms on kidney function among hypertensive sewage workers

Cadmium (Cd) as nephrotoxicant metal exerts its potent effect mainly on renal tubules disturbing its functions. A cross-sectional study was conducted on 55 sewage workers occupationally exposed to Cd and 50 control subjects. The study aimed to assess the effect of low-level Cd exposure on blood pressure and renal function in terms of serum cystatin-C levels. The associations between genetic polymorphisms of ACEI/D and ACE G2350A and hypertension and tubular injury among workers were studied. We analyzed blood and urine Cd concentration (U-Cd), serum cystatin-C, ACE I/D polymorphisms, and ACE G2350A, and blood pressure was measured. Results recorded a significant rise in serum and U-Cd and cystatin-C levels in sewage workers compared with controls. Significant distribution in genotype frequency of ACE I/D and ACE G2350A gene was detected. An association in DD genotype of ACE I/D with a rise in serum and U-Cd was observed in workers. In wild type genotype GG of ACE G2350A gene, a significant rise in serum cystatin-C levels and diastolic pressure was found while in heterozygote genotype GA significant rise in U-Cd levels was detected. Also, the association of AA genotype of ACE G2350A gene with a significant rise in serum and U-Cd and cystatin-C levels was shown among workers compared with control groups. Our findings indicated an association of ACE DD polymorphism in conjugation with GG genotype of ACE2 with hypertension and tubular injury in sewage workers.

The Intersection between COVID-19, the Gene Family of ACE2 and Alzheimer's Disease

We reviewed factors that might influence COVID-19 outcomes (eg, neurological symptoms), including the link to Alzheimer's disease. Since the virus triggers COVID-19 infection through binding to ACE2, we focused on the ACE2 gene family, including ACE. Both ACE2 and ACE are involved in the renin-angiotensin system (RAS). In general, ACE causes inflammation and vasoconstriction, while ACE2 leads to anti-inflammation activity and vasodilation. The disturbed balance between these counter-regulatory pathways could influence susceptibility to COVID-19. Notably, dysregulation of the RAS-equilibrium contributes to Alzheimer's disease. Differences in the incidence and symptoms of COVID-19 in diverse populations could be attributed to variability in the human genome. For example, ACE and ACE2 variations could modify the outcome of COVID-19 in different populations. It would be important to conduct genome-wide studies to detect variants influencing COVID-19 presentation, with a special focus on variants affecting immune-related pathways and expression of RAS-related genes.

ACE2 and TMPRSS2 polymorphisms in various diseases with special reference to its impact on COVID-19 disease

Background

A carboxypeptidase protein called ACE2 is found in many organs. ACE2 protein can play a pivotal role to regulate the pathological changes of several diseases including COVID-19. TMPRSS2 gene is expressed in many human tissues and plays a critical role in spreading the infection of the viruses including coronavirus and progression of prostate cancer, and hence could be used as a potential drug target. There are limited reports on occurrence of genetic polymorphism of ACE2 and TMPRSS2 in general population, expressions in pathological conditions, and its impact on COVID-19 disease. Hence we comprehended the occurrence of ACE2, TMPRSS2 polymorphism in general population, expression in various diseases and its impact on COVID-19 disease.

Method

We utilized multiple databases, PubMed (Medline), EMBASE and Google Scholar for literature search.

Description

ACE2 polymorphisms have significant linkages with various diseases, including severity of SARS-CoV-2 infection. Genetic variations of these genes contribute to individual's genetic susceptibility to viral infection and its subsequent clearance. The diversity and variations in the population distribution of these genes, might greatly influence and in turn reflect into the observed population and gender differences of the severity and clinical outcomes of SARS-CoV-2 infection.

Conclusion

There are diversities in distribution of ACE2 and TMPRSS2 polymorphisms among different populations. Analyzing the genetic variants and expression of ACE2 and TMPRSS2 genes, in a population may provide the genetic marker for susceptibility or resistance against the coronavirus infection, which might be useful for identifying the susceptible population groups for targeted interventions and for making relevant public health policy decisions.

SARS-CoV-2 and mitochondrial health: implications of lifestyle and ageing

Infection with SARs-COV-2 displays increasing fatality with age and underlying co-morbidity, in particular, with markers of the metabolic syndrome and diabetes, which seems to be associated with a "cytokine storm" and an altered immune response. This suggests that a key contributory factor could be immunosenescence that is both age-related and lifestyle-induced. As the immune system itself is heavily reliant on mitochondrial function, then maintaining a healthy mitochondrial system may play a key role in resisting the virus, both directly, and indirectly by ensuring a good vaccine response. Furthermore, as viruses in general, and quite possibly this new virus, have also evolved to modulate immunometabolism and thus mitochondrial function to ensure their replication, this could further stress cellular bioenergetics. Unlike most sedentary modern humans, one of the natural hosts for the virus, the bat, has to "exercise" regularly to find food, which continually provides a powerful adaptive stimulus to maintain functional muscle and mitochondria. In effect the bat is exposed to regular hormetic stimuli, which could provide clues on how to resist this virus. In this paper we review the data that might support the idea that mitochondrial health, induced by a healthy lifestyle, could be a key factor in resisting the virus, and for those people who are perhaps not in optimal health, treatments that could support mitochondrial function might be pivotal to their long-term recovery.

COVID-19 and Microvascular Disease: Pathophysiology of SARS-CoV-2 Infection With Focus on the Renin-Angiotensin System

The recently described severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected millions of people, with thousands of fatalities. It has prompted global efforts in research, with focus on the pathophysiology of coronavirus disease-19 (COVID-19), and a rapid surge of publications. COVID-19 has been associated with a myriad of clinical manifestations, including the lungs, heart, kidneys, central nervous system, gastrointestinal system, skin, and blood coagulation abnormalities. The endothelium plays a key role in organ dysfunction associated with severe infection, and current data suggest that it is also involved in SARS-CoV-2-induced sepsis. This critical review aimed to address a possible unifying mechanism underlying the diverse complications of COVID-19: microvascular dysfunction, with emphasis on the renin-angiotensin system. In addition, research perspectives are suggested in order to expand understanding of the pathophysiology of the infection.