Association of polymorphisms of angiotensin I converting enzyme 2 with retinopathy in type 2 diabetes mellitus among Chinese individuals

Genetic Variants within SARS-CoV-2 Human Receptor Genes May Contribute to Variable Disease Outcomes in Different Ethnicities

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has evolved into a global pandemic, with an alarming infectivity and mortality rate. Studies have examined genetic effects on SARS-CoV-2 disease susceptibility and severity within Eurasian populations. These studies identified contrasting effects on the severity of disease between African populations. Genetic factors can explain some of the diversity observed within SARS-CoV-2 disease susceptibility and severity. Single nucleotide polymorphisms (SNPs) within the SARS-CoV-2 receptor genes have demonstrated detrimental and protective effects across ethnic groups. For example, the TT genotype of rs2285666 (Angiotensin-converting enzyme 2 (ACE2)) is associated with the severity of SARS-CoV-2 disease, which is found at higher frequency within Asian individuals compared to African and European individuals. In this study, we examined four SARS-CoV-2 receptors, ACE2, Transmembrane serine protease 2 (TMPRSS2), Neuropilin-1 (NRP1), and Basigin (CD147). A total of 42 SNPs located within the four receptors were reviewed: ACE2 (12), TMPRSS2 (10), BSG (CD147) (5), and NRP1 (15). These SNPs may be determining factors for the decreased disease severity observed within African individuals. Furthermore, we highlight the absence of genetic studies within the African population and emphasize the importance of further research. This review provides a comprehensive summary of specific variants within the SARS-CoV-2 receptor genes, which can offer a better understanding of the pathology of the SARS-CoV-2 pandemic and identify novel potential therapeutic targets.

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 underlying mechanisms for severe COVID-19 progression in people with diabetes mellitus: a critical review

Diabetes mellitus (DM) has a high incidence of comorbidities among patients with severe coronavirus disease 2019 (COVID-19). The elevated prevalence of DM in the world population makes it a significant risk factor because diabetic individuals appear to be prone to clinical complications and have increased mortality rates. Here, we review the possible underlying mechanisms involved in DM that led to worse outcomes in COVID-19. The impacts of hyperglycemia side effects, secondary comorbidities, weakened innate and adaptive immunity, chronic inflammation, and poor nutritional status, commonly present in DM, are discussed. The role of the SARS-CoV-2 receptor and its polymorphic variations on higher binding affinity to facilitate viral uptake in people with DM were also considered. Clinical differences between individuals with type 1 DM and type 2 DM affected by COVID-19 and the potential diabetogenic effect of SARS-CoV-2 infection were addressed.

The Impact of ACE2 Polymorphisms on COVID-19 Disease: Susceptibility, Severity, and Therapy

The coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has currently spread worldwide, leading to high morbidity and mortality. As the putative receptor of SARS-CoV-2, angiotensin-converting enzyme 2 (ACE2) is widely distributed in various tissues and organs of the human body. Simultaneously, ACE2 acts as the physiological counterbalance of ACE providing homeostatic regulation of circulating angiotensin II levels. Given that some ACE2 variants are known to cause an increase in the ligand-receptor affinity, their roles in acquisition, progression and severity of COVID-19 disease have aroused widespread concerns. Therefore, we summarized the latest literature and explored how ACE2 variants and epigenetic factors influence an individual’s susceptibility to SARS-CoV-2 infection and disease outcome in aspects of ethnicity, gender and age. Meanwhile, the possible mechanisms for these phenomena were discussed. Notably, recombinant human ACE2 and ACE2-derived peptides may have special benefits for combating SARS-CoV-2 variants and further studies are warranted to confirm their effects in later stages of the disease process. As the uncertainty regarding the severity and transmissibility of disease rises, a more in-depth understanding of the host genetics and functional characteristics of ACE2 variants will not only help explain individual clinical differences of the disease, but also contribute to providing effective measures to develop solutions and manage future outbreaks of SARS-CoV-2.

Genetic associated complications of type 2 Diabetes Mellitus: a review

According to the International Diabetes Federation, the number of adults (age of 20-79) being diagnosed with Diabetes Mellitus (DM) have increased from 285 million in year 2009 to 463 million in year 2019 which comprises of 95% Type 2 DM patient (T2DM). Research have claimed that genetic predisposition could be one of the factors causing T2DM complications. In addition, T2DMcomplications cause an incremental risk to mortality. Therefore, this article aims to discuss some complications of T2DM in and their genetic association. The complications that are discussed in this article are diabetic nephropathy, diabetes induced cardiovascular disease, diabetic neuropathy, Diabetic Foot Ulcer (DFU) and Alzheimer's disease. According to the information obtained, genes associated with diabetic nephropathy (DN) are gene GABRR1 and ELMO1 that cause injury to glomerular. Replication of genes FRMD3, CARS and MYO16/IRS2 shown to have link with DN. The increase of gene THBS2, NGAL, PIP, TRAF6 polymorphism, ICAM-1 encoded for rs5498 polymorphism and C667T increase susceptibility towards DN in T2DM patient. Genes associated with cardiovascular diseases are Adiponectin gene (ACRP30) and Apolipoprotein E (APOE) polymorphism gene with ξ2 allele. Haptoglobin (Hp) 1-1 genotype and Mitochondria Superoxide Dismutase 2 (SOD2) plays a role in cardiovascular events. As for genes related to diabetic neuropathy, Janus Kinase (JAK), mutation of SCN9A and TRPA1 gene and destruction of miRNA contribute to pathogenesis of diabetic neuropathy among T2DM patients. Expression of cytokine IL-6, IL-10, miR-146a are found to cause diabetic neuropathy. Besides, A1a16Va1 gene polymorphism, an oxidative stress influence was found as one of the gene factors. Diabetic retinopathy (DR) is believed to have association with Monocyte Chemoattractant Protein-1 (MCP-1) and Insulin-like Growth Factor 1 (IGF1). Over-expression of gene ENPP1, IL-6 pro-inflammatory cytokine, ARHGAP22's protein rs3844492 polymorphism and TLR4 heterozygous genotype are contributing to significant pathophysiological process causing DR, while research found increases level of UCP1 gene protects retina cells from oxidative stress. Diabetic Foot Ulcer (DFU) is manifested by slowing in reepithelialisation of keratinocyte, persistence wound inflammation and healing impairment. Reepithelialisation disturbance was caused by E2F3 gene, reduction of Tacl gene encoded substance P causing persistence inflammation while expression of MMp-9 polymorphism contributes to healing impairment. A decrease in HIF-1a gene expression leads to increased risk of pathogenesis, while downregulation of TLR2 increases severity of wound in DFU patients. SNPs alleles has been shown to have significant association between the genetic dispositions of T2DM and Alzheimer's disease (AD). The progression of AD can be due to the change in DNA methylation of CLOCK gene, followed with worsening of AD by APOE4 gene due to dyslipidaemia condition in T2DM patients. Insulin resistance is also a factor that contributes to pathogenesis of AD.

SARS-CoV-2 Receptor ACE2 Gene Is Associated with Hypertension and Severity of COVID 19: Interaction with Sex, Obesity, and Smoking

BACKGROUND

Angiotensin-converting enzyme 2 (ACE2) has been identified as the entry receptor for coronaviruses into human cells, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes coronavirus disease 2019 (COVID-19). Since hypertension (HT) is a leading comorbidity in non-survivors of COVID-19, we tested for association between ACE2 gene and HT in interaction with specific pre-existing conditions known to be associated with COVID-19 severity.

METHODS

Genetic analysis of ACE2 gene was conducted in French-Canadian (FC) and British populations.

RESULTS

In FC individuals, the T allele of the single nucleotide polymorphism rs2074192 of ACE2 gene was a risk factor for HT in adult obese males [odds ratio (OR) = 1.39, 95% confidence interval (CI) 1.06-1.83)] and even more so in obese males who smoked (OR = 1.67, CI: 1.24-2.55), but not in lean males, non-smoker males or females. The T allele was significantly associated with severity of HT and with earlier penetrance of HT in obese smoking males. Significant interaction between the T allele and obesity was present in both sexes. The association of ACE2 (rs233575) genotype with blood pressure was also seen in adolescents but the interaction with obesity was present only in females. Several variants in ACE2 gene were found to be associated with HT in obese, smoking males in British individuals of the UK Biobank. In addition, we observed more severe outcomes to COVID-19 in association with ACE2 risk alleles in obese, smoking males.

CONCLUSIONS

This is the first report that ACE2 variants are associated with earlier penetrance and more severe HT and with more severe outcomes of COVID-19 in obese smoking males.

Analysis of the SARS-CoV-2-host protein interaction network reveals new biology and drug candidates: focus on the spike surface glycoprotein and RNA polymerase

Introduction: The COVID-19 pandemic originated from the emergence of anovel coronavirus, SARS-CoV-2, which has been intensively studied since its discovery in order to generate the knowledge necessary to accelerate the development of vaccines and antivirals. Of note, many researchers believe there is great potential in systematically identifying host interactors of viral factors already targeted by existing drugs.Areas Covered: Herein, the authors discuss in detail the only available large-scale systematic study of the SARS-CoV-2-host protein-protein interaction network. More specifically, the authors review the literature on two key SARS-CoV-2 drug targets, the Spike surface glycoprotein, and the RNA polymerase. The authors also provide the reader with their expert opinion and future perspectives.Expert opinion: Interactions made by viral proteins with host factors reveal key functions that are likely usurped by the virus and, as aconsequence, points to known drugs that can be repurposed to fight viral infection and collateral damages that can exacerbate various disease conditions in COVID-19.

COVID-19-A Theory of Autoimmunity Against ACE-2 Explained

The COVID-19 pandemic caused by the coronavirus SARS-COV-2 has cost many lives worldwide. In dealing with affected patients, the physician is faced with a very unusual pattern of organ damage that is not easily explained on the basis of prior knowledge of viral-induced pathogenesis. It is established that the main receptor for viral entry into tissues is the protein angiotensin-converting enzyme-2 ["ACE-2", (1)]. In a recent publication (2), a theory of autoimmunity against ACE-2, and/or against the ACE-2/SARS-COV-2 spike protein complex or degradation products thereof, was proposed as a possible explanation for the unusual pattern of organ damage seen in COVID-19. In the light of more recent information, this manuscript expands on the earlier proposed theory and offers additional, testable hypotheses that could explain both the pattern and timeline of organ dysfunction most often observed in COVID-19.

Germline Genetic Variants of Viral Entry and Innate Immunity May Influence Susceptibility to SARS-CoV-2 Infection: Toward a Polygenic Risk Score for Risk Stratification

The ongoing COVID-19 pandemic caused by the novel coronavirus, SARS-CoV-2 has affected all aspects of human society with a special focus on healthcare. Although older patients with preexisting chronic illnesses are more prone to develop severe complications, younger, healthy individuals might also exhibit serious manifestations. Previous studies directed to detect genetic susceptibility factors for earlier epidemics have provided evidence of certain protective variations. Following SARS-CoV-2 exposure, viral entry into cells followed by recognition and response by the innate immunity are key determinants of COVID-19 development. In the present review our aim was to conduct a thorough review of the literature on the role of single nucleotide polymorphisms (SNPs) as key agents affecting the viral entry of SARS-CoV-2 and innate immunity. Several SNPs within the scope of our approach were found to alter susceptibility to various bacterial and viral infections. Additionally, a multitude of studies confirmed genetic associations between the analyzed genes and autoimmune diseases, underlining the versatile immune consequences of these variants. Based on confirmed associations it is highly plausible that the SNPs affecting viral entry and innate immunity might confer altered susceptibility to SARS-CoV-2 infection and its complex clinical consequences. Anticipating several COVID-19 genomic susceptibility loci based on the ongoing genome wide association studies, our review also proposes that a well-established polygenic risk score would be able to clinically leverage the acquired knowledge.

ACE2: the molecular doorway to SARS-CoV-2

The angiotensin-converting enzyme 2 (ACE2) is the host functional receptor for the new virus SARS-CoV-2 causing Coronavirus Disease 2019. ACE2 is expressed in 72 different cell types. Some factors that can affect the expression of the ACE2 are: sex, environment, comorbidities, medications (e.g. anti-hypertensives) and its interaction with other genes of the renin-angiotensin system and other pathways. Different factors can affect the risk of infection of SARS-CoV-2 and determine the severity of the symptoms. The ACE2 enzyme is a negative regulator of RAS expressed in various organ systems. It is with immunity, inflammation, increased coagulopathy, and cardiovascular disease. In this review, we describe the genetic and molecular functions of the ACE2 receptor and its relation with the physiological and pathological conditions to better understand how this receptor is involved in the pathogenesis of COVID-19. In addition, it reviews the different comorbidities that interact with SARS-CoV-2 in which also ACE2 plays an important role. It also describes the different factors that interact with the virus that have an influence in the expression and functional activities of the receptor. The goal is to provide the reader with an understanding of the complexity and importance of this receptor.

Angiotensin converting enzyme: A review on expression profile and its association with human disorders with special focus on SARS-CoV-2 infection

Angiotensin-converting enzyme (ACE) and its homologue, ACE2, have been mostly associated with hypertensive disorder. However, recent pandemia of SARS-CoV-2 has put these proteins at the center of attention, as this virus has been shown to exploit ACE2 protein to enter cells. Clear difference in the response of affected patients to this virus has urged researchers to find the molecular basis and pathophysiology of the cell response to this virus. Different levels of expression and function of ACE proteins, underlying disorders, consumption of certain medications and the existence of certain genomic variants within ACE genes are possible explanations for the observed difference in the response of individuals to the SARS-CoV-2 infection. In the current review, we discuss the putative mechanisms for this observation.

ACE2 as Drug Target of COVID-19 Virus Treatment, Simplified Updated Review

Background

Since its first appearance in December of 2019, regular updates around the world demonstrates that the number of new Corona Virus 2019 (COVID-19) cases are increasing rapidly, indicating that not only does COVID-19 exhibit a rapid spread pattern, but human intervention is necessary for its resolution. Up until today (27-5-2020) and according to the World Health Organization (WHO), the number of confirmed COVID-19 cases has surpassed 4.5 million with more than 307, 500 deaths. Almost all countries have been affected by COVID-19, and resultingly, various drug trials have been conducted, however, a targeted treatment remains to be made accessible to the public. Recently, Angiotensin-Converting Enzyme-2 (ACE2) has gained some attention for its discovery as a potential attachment target of COVID-19.

Methods

We reviewed the most recent evidence regarding ACE2 distribution and action, the binding mechanism of COVID-19 and its correlation to cellular injury, ACE2 polymorphisms and its association to fatal COVID-19 and susceptibility and, finally, current ACE2-based pharmacotherapies against COVID-19.

Results

Blocking the ACE2 receptor-binding domain (RBD) using a specific ligand can prevent COVID-19 from binding, and consequently cellular entry and injury. Comparatively, soluble ACE2, which has a higher affinity to COVID-19, can neutralize COVID-19 without affecting the homeostatic function of naturally occurring ACE2. Lastly, ACE2 mutations and their possible effect on the binding activity of COVID-19 may enable researchers to identify high-risk groups before they become exposed to COVID-19.

Conclusion

ACE2 represents a promising target to attenuate or prevent COVID-19 associated cellular injury.

Structural variations in human ACE2 may influence its binding with SARS-CoV-2 spike protein

The recent pandemic of COVID‐19, caused by SARS‐CoV‐2, is unarguably the most fearsome compared with the earlier outbreaks caused by other coronaviruses, SARS‐CoV and MERS‐CoV. Human ACE2 is now established as a receptor for the SARS‐CoV‐2 spike protein. Where variations in the viral spike protein, in turn, lead to the cross‐species transmission of the virus, genetic variations in the host receptor ACE2 may also contribute to the susceptibility and/or resistance against the viral infection. This study aims to explore the binding of the proteins encoded by different human ACE2 allelic variants with SARS‐CoV‐2 spike protein. Briefly, coding variants of ACE2 corresponding to the reported binding sites for its attachment with coronavirus spike protein were selected and molecular models of these variants were constructed by homology modeling. The models were then superimposed over the native ACE2 and ACE2‐spike protein complex, to observe structural changes in the ACE2 variants and their intermolecular interactions with SARS‐CoV‐2 spike protein, respectively. Despite strong overall structural similarities, the spatial orientation of the key interacting residues varies in the ACE2 variants compared with the wild‐type molecule. Most ACE2 variants showed a similar binding affinity for SARS‐CoV‐2 spike protein as observed in the complex structure of wild‐type ACE2 and SARS‐CoV‐2 spike protein. However, ACE2 alleles, rs73635825 (S19P) and rs143936283 (E329G) showed noticeable variations in their intermolecular interactions with the viral spike protein. In summary, our data provide a structural basis of potential resistance against SARS‐CoV‐2 infection driven by ACE2 allelic variants.

Structural modelling and molecular superimposition analyses shows variations in the interactions between proteins encoded by some human ACE2 alleles and SARS‐CoV‐2 spike protein. The findings provide direction to the targeted allele screening in COVID‐19 patients, which could further be used in predicting the prognosis of the disease and allocation of the health resources.

ACE2 polymorphisms associated with cardiovascular risk in Uygurs with type 2 diabetes mellitus

Background

Type 2 diabetes mellitus (T2D), rapidly increasing to epidemic proportions, globally escalates cardiovascular disease risk. Although intensive interventions and comprehensive management of environmental risks factors for T2D are associated with reduced cardiovascular disease, such approaches are limited for individuals with high genetic T2D risk. In this study we investigated possible associations of ACE2 polymorphisms and cardiovascular risks in Uygur patients with T2D.

Methods

275 Uygur T2D patients and 272 non-diabetic Uygur individuals were enrolled as study participants. 14 ACE2 polymorphisms were genotyped by Matrix-assisted laser desorption ionization time-of-flight mass spectrometry.

Results

ACE2 SNP rs1978124, rs2048683, rs2074192, rs233575, rs4240157, rs4646156, rs4646188 and rs879922 were associated with T2D (all P < 0.05). The 8 diabetic risk related ACE2 SNPs were further associated with diabetic related cardiovascular complications or events but exhibited heterogeneity as fellows: firstly, almost all diabetic risk related ACE2 SNPs (all P < 0.05) were associated with increased SBP except rs1978124 and rs2074192, while rs2074192, rs4646188 and rs879922 were associated elevated DBP (all P < 0.05). Secondly, SNP rs4646188 was not correlated with any type of dyslipidemia (TRIG, HDL-C, LDL-C or CHOL), and the other 7 diabetic risk related loci were at least correlated with one type of dyslipidemia (all P < 0.05). In particular, rs879922 were simultaneously correlated with four type of dyslipidemia (all P < 0.05). Thirdly, ACE2 SNP rs2074192 and rs879922 were associated with carotid arteriosclerosis stenosis (CAS) ≥ 50% (both P < 0.05). Fourthly, ACE2 SNP rs2074192, rs4240157, rs4646188 and 879922 were associated with increased MAU (all P < 0.05). In addition, ACE2 SNP rs2048683, rs4240157, rs4646156, rs4646188 and rs879922 were linked to heavier LVMI (all P < 0.05), but only rs4240157, rs4646156 and rs4646188 were associated with lower LVEF (all P < 0.05).

Conclusion

ACE2 SNP rs879922 may be a common genetic loci and optimal genetic susceptibility marker for T2D and T2D related cardiovascular risks in Uygurs.

Electronic supplementary material

The online version of this article (10.1186/s12933-018-0771-3) contains supplementary material, which is available to authorized users.

The Association Between ACE2 Gene Polymorphism and the Stroke Recurrence in Chinese Population

OBJECTIVES

The angiotensin-converting enzyme 2 (ACE2) is closely associated with cardiovascular disease and cerebrovascular disease. Most studies on ACE2 gene polymorphism focused on its relations with cardiovascular disease, but there was a lack of research on its relations with stroke. Our study aimed to explore the association between 4 single-nucleotidepolymorphisms (SNPs) of ACE2 gene polymorphism and stroke recurrence.

DESIGN AND PARTICIPANTS

In our study, the case group included 125 stroke patients with recurrence and the control group included 153 patients without recurrence. Four SNPs (rs2106809, rs2285666, rs879922, and rs2074192) were genotyped by Ligase detection reaction. The association between stroke recurrence and SNPs were analyzed by multivariate logistic regression.

RESULTS

We find no association between ACE2 gene polymorphism and stroke recurrence. Haplotype A-G-C may associate with the stoke recurrence of male patients. The recurrence risk of male stroke patients with hypertension history and rs2285666-C allele is 2.82 times as high as that of those without hypertension history but with T allele. Among male stroke patients with hypertension history, the recurrence risk of those with rs2285666-C allele is 2.38 times as high as those with T allele; and the recurrence risk of those with rs2106809-A allele is 2.12 times as high as those with G allele. But those recurrence risks lose their statistical significance after adjustment for other factors.

CONCLUSIONS

We find no influence of ACE2 gene polymorphism on stroke recurrence and only find possible interaction between hypertension history and the ACE2 gene in male stroke patients.