Multidrug Resistance Profiles and Resistance Mechanisms to ß-Lactams and Fluoroquinolones in Bacterial Isolates from Hospital Wastewater in Bangladesh.

Multidrug resistance (MDR) is one of the deadliest public health concerns of the 21st century, rendering many powerful antibiotics ineffective. The current study provides important insights into the prevalence and mechanisms of antibiotic resistance in hospital wastewater isolates. In this study, we determined the MDR profile of 68 bacterial isolates collected from five different hospitals in Dhaka, Bangladesh. Of them, 48 bacterial isolates were identified as Enterobacteriaceae. Additionally, we investigated the prevalence and distribution of five beta-lactam resistance genes, as well as quinolone resistance mechanisms among the isolates. The results of this study showed that 87% of the wastewater isolates were resistant to at least three different antibiotic classes, as revealed using the disc diffusion method. Resistance to ß-lactams was the most common, with 88.24% of the isolates being resistant, closely followed by macrolides (80.88% resistant). Polymyxin was found to be the most effective against wastewater isolates, with 29.41% resistant isolates. The most common ß-lactam resistance genes found in wastewater isolates were blaTEM (76.09%), blaCTX-M1 (71.74%), and blaNDM (67.39%). Two missense mutations in the quinolone resistance-determining region (QRDR) of gyrA (S83L and D87N) and one in both parC (S80I) and parE (S458A) were identified in all isolates, and one in parE (I529L), which had not previously been identified in Bangladesh. These findings suggest that hospital wastewater acts as an important reservoir of antibiotic-resistant bacteria wherein resistance mechanisms to ß-lactams and fluoroquinolones are obvious. Our data also emphasize the need for establishing a nationwide surveillance system for antibiotic resistance monitoring to ensure that hospitals sanitize their wastewater before disposal, and regulation to ensure hospital wastewater is kept away from community settings.

Association study of leukocyte telomere length and genetic polymorphism within hTERT promoter with type 2 diabetes in Bangladeshi population.

Telomeres are protective cap on the ends of DNA of non-coding tandem repeats of TTAGGG. Human telomerase reverse transcriptase (hTERT) is a catalytic subunit of telomerase that maintains the structure of telomeres. Type 2 diabetes (T2D) affects multi-organ and telomere length by altering telomerase activity. We aimed to evaluate the relative telomere length (RTL) and risk association of rs2853669 with T2D in Bangladeshi population. RTL was measured in 408 unrelated Bangladeshi (224 T2D and 184 healthy) using primers for target gene and reference gene albumin. Genotypic frequencies for rs2853669 were determined using TaqMan® probes. The mean level of age adjusted RTL (AARTL) varied significantly between the healthy and individuals with T2D for all the genotypes with respect to rs2853669. Moreover, healthy individuals had significantly higher AARTL than T2D. Similar findings were observed when study participants were stratified based on their gender. Association studies revealed that under codominant model of inheritance, TC genotype showed protective role against development of type 2 diabetes. This study suggests a possible role of telomere biology in T2DM, but their association needs to be evaluated further with a larger series and matched healthy controls.

Diabetes and Genetics: A Relationship Between Genetic Risk Alleles, Clinical Phenotypes and Therapeutic Approaches.

Unveiling human genome through successful completion of Human Genome Project and International HapMap Projects with the advent of state of art technologies has shed light on diseases associated genetic determinants. Identification of mutational landscapes such as copy number variation, single nucleotide polymorphisms or variants in different genes and loci have revealed not only genetic risk factors responsible for diseases but also region(s) playing protective roles. Diabetes is a global health concern with two major types - type 1 diabetes (T1D) and type 2 diabetes (T2D). Great progress in understanding the underlying genetic predisposition to T1D and T2D have been made by candidate gene studies, genetic linkage studies, genome wide association studies with substantial number of samples. Genetic information has importance in predicting clinical outcomes. In this review, we focus on recent advancement regarding candidate gene(s) associated with these two traits along with their clinical parameters as well as therapeutic approaches perceived. Understanding genetic architecture of these disease traits relating clinical phenotypes would certainly facilitate population stratification in diagnosing and treating T1D/T2D considering the doses and toxicity of specific drugs.

Non-coding Single Nucleotide Variants of Renin and the (Pro)renin Receptor are Associated with Polygenic Diseases in a Bangladeshi Population.

Non-coding variants or single-nucleotide polymorphisms (SNPs) play pivotal roles in orchestrating pathogeneses of polygenic diseases, including hypertension (HTN) and diabetes. Renin-angiotensin system (RAS) components-renin and (pro)renin receptor [(P)RR]-maintain homeostasis of body fluids. Genetic variants of RAS components are associated with risk of HTN and type 2 diabetes (T2D) in different ethnic groups. We identified associations of SNPs within the renin and (P)RR genes with HTN, T2D, and T2D-associated hypertension in 911 unrelated Bangladeshi individuals. Five non-coding SNPs were involved in modulating regulatory elements in diverse cell types when tagged with other SNPs. rs61827960 was not associated with any disease; rs3730102 was associated with increased risk of HTN and T2D while under dominant model, it showed protective role against T2D-associated HTN. SNP rs11571079 was associated with increased risk of HTN and T2D-associated HTN and decreased risk of T2D, exerting a protective effect. Renin haplotypes GCA and GTG were related to increased risk of T2D and T2D-associated HTN, respectively. Heterogeneous linkage of genotypic and allelic frequencies of rs2968915 and rs3112298 of (P)RR was observed. The (P)RR haplotype GA was associated with increased risk of HTN and significantly decreased risk of T2D. These findings highlight important roles of non-coding variants of renin and (P)RR genes in the etiology of several polygenic diseases.

Functional Polymorphism Located in the microRNA Binding Site of the Insulin Receptor (INSR) Gene Confers Risk for Type 2 Diabetes Mellitus in the Bangladeshi Population.

Bangladesh has the second largest number of adults with diabetes in South Asia. Compelling evidence suggest that miRNAs contribute to the etiology of Type 2 diabetes mellitus (T2DM) by regulating many aspects of glucose homeostasis. Hence, we hypothesized that genetic polymorphisms in the diabetes-related miRNA target-binding sites could be associated with the risk of T2DM in Bangladesh. The reference Single nucleotide polymorphism (SNP) data from the Insulin Receptor (INSR) gene were downloaded from the ENSEMBL genome browser release 88 and further analyzed in silico for identifying SNPs with deleterious effect and clinical relationships. Further, case-control study using the microRNA-binding site polymorphism rs1366600 (T > C) located at the 3' UTR of the INSR gene was carried out in 217 T2DM patients and 237 healthy controls from Bangladesh. Genotyping was performed using the real time PCR based allele discrimination method. The results showed that the minor allele 'C' is associated with increased risk of T2DM [Odds ratio (OR) 1.87; 95% confidence intervals (CI) 1.28-2.74; P = 0.0010]. When we dissected our analysis to include the dominant model (CC + TC genotype against the TT genotype), we found that the CC and TC genotypes were associated with increased risk of T2DM in Bangladeshi population (OR 2.01; 95% CI 1.31-3.07; P = 0.0012). However, in recessive model (CC vs TT + TC); the effect was not statistically significant (OR 2.23; 95% CI 0.66-7.51; P = 0.1848). Stratification of our data based on the gender of the cases and controls showed similar degree of risk association with respect to different genotypes and alleles. Our study showed that the miRNA binding site polymorphism rs1366600 located at the 3'-UTR region of the INSR gene is associated with increased risk of T2DM in Bangladeshi individuals.

Correction to: Functional Polymorphism Located in the microRNA Binding Site of the Insulin Receptor (INSR) Gene Confers Risk for Type 2 Diabetes Mellitus in the Bangladeshi Population.

The original version of this article unfortunately contained a mistake in the co-author name. It should be Farhana Jahan instead of Farhan Jahan.

Escherichia coli-based production of recombinant ovine angiotensinogen and its characterization as a renin substrate.

BACKGROUND: Angiotensinogen (ANG) is a macromolecular precursor of angiotensin, which regulates blood pressure and electrolyte balance. ANG is specifically cleaved by renin, an aspartic protease, to initiate the angiotensin-processing cascade. Ovine ANG (oANG) from sheep plasma has been shown to be a better substrate for human renin, and it has been used in clinical renin assays. To expand the availability of oANG, we aimed to produce milligram levels of recombinant oANG using an Escherichia coli expression system. RESULTS: When recombinant oANG was expressed from a T7 promoter in various E. coli strains at 37 °C, it accumulated in the insoluble fraction. However, by expressing oANG at 37 °C from a tac promoter, which has weaker transcriptional activity than a T7 promoter, we significantly elevated the ratio of soluble to insoluble recombinant oANG. Using a novel culturing system and auto-induction culture medium, we purified tac-expressed recombinant oANG to homogeneity, with a yield of 4.0 mg per liter of culture. Based on size-exclusion gel filtration analysis and dynamic light scattering analysis, the resulting purified oANG is a monomer in solution. The circular dichroism spectrum of E. coli-expressed recombinant oANG was similar to that of oANG expressed in CHO cells. Differential scanning fluorimetry showed that both preparations undergo a two-state transition during thermal denaturation, and the melting temperatures of recombinant oANG expressed in E. coli and CHO cells were 49.4 ± 0.16 °C and 51.6 ± 0.19 °C, respectively. The K(m) values of both oANG preparations were similar; the k(cat) value of E. coli-expressed recombinant oANG was slightly higher than that of CHO-expressed oANG. CONCLUSIONS: Recombinant oANG expressed in E. coli functions as a human renin substrate. This study presents an E. coli-based system for the rapid production of milligram quantities of a human renin substrate, which will be useful for both fundamental and clinical studies on renin and hypertension.

B and T Cell Epitope-Based Peptides Predicted from Evolutionarily Conserved and Whole Protein Sequences of Ebola Virus as Vaccine Targets.

Ebola virus (EBV) has become a serious threat to public health. Different approaches were applied to predict continuous and discontinuous B cell epitopes as well as T cell epitopes from the sequence-based and available three-dimensional structural analyses of each protein of EBV. Peptides '(79) VPSATKRWGFRSGVPP(94) ' from GP1 and '(515) LHYWTTQDEGAAIGLA(530) ' from GP2 of Ebola were found to be the consensus peptidic sequences predicted as linear B cell epitope of which the latter contains a region (519) TTQDEG(524) that fulfilled all the criteria of accessibility, hydrophilicity, flexibility and beta turn region for becoming an ideal B cell epitope. Different nonamers as T cell epitopes were obtained that interacted with different numbers of MHC class I and class II alleles with a binding affinity of <100 nm. Interestingly, these alleles also bound to the MHC class I alleles mostly prevalent in African and South Asian regions. Of these, 'LANETTQAL' and 'FLYDRLAST' nonamers were predicted to be the most potent T cell epitopes and they, respectively, interacted with eight and twelve class I alleles that covered 63.79% and 54.16% of world population, respectively. These nonamers were found to be the core sequences of 15mer peptides that interacted with the most common class II allele, HLA-DRB1*01:01. They were further validated for their binding to specific class I alleles using docking technique. Thus, these predicted epitopes may be used as vaccine targets against EBV and can be validated in model hosts to verify their efficacy as vaccine.

Genetic and epigenetic analyses of IFN-γ gene proximal promoter region underlying positive correlation between persistently high anti-SARS-CoV-2 IgG and IFN-γ among COVID-19 vaccinated Bangladeshi adults.

IFN-γ is an immunological modulator influencing IgG isotype and concentration, which present a correlate of protection to evaluate vaccine efficacy. As transiently expressed, stable genetic and epigenetic signatures of the cytokine's expression may exist. This study investigates correlation between plasma IFN-γ and anti-SARS-CoV-2 IgG levels, seeking genetic polymorphisms and epigenetic variations within the IFN-γ gene proximal promoter. 200 COVID-19-vaccinated adults were classified into seropositive and seronegative groups based on plasma anti-SARS-CoV-2 IgG. Upon correlation analysis between anti-SARS-CoV-2 IgG and IFN-γ levels, IFN-γ gene proximal promoter region was subjected to nucleotide sequencing for two subsets: seronegative (21 < Days post-vaccination ≤180, n = 11) and seropositive (IgG > Q3 and Days post-vaccination >180, n = 24). Relative unmethylation of IFN-γ proximal promoter was assessed for the latter subset and its correlation with plasma IFN-γ and IgG levels was evaluated. A statistically significant positive correlation (r = 0.492, p = 0.018) was observed between IFN-γ and anti-SARS-CoV-2 IgG in the seropositive group with persistently high IgG titre (IgG > Q3, Days elapsed post-vaccination >180). A heterozygous 5'-UTR variant (rs776667149:C>T) identified in one seronegative individual revealed a potential impact on PKR-mediated translational attenuation of IFN-γ mRNA. No significant correlation was found between IFN-γ proximal promoter unmethylation and its plasma levels among HAR individuals with Days post-vaccination of either >180 (r = 0.14, p = 0.679) or < 180 (r = -0.062, p = 0.693). This study demonstrates an extent of humoral immunity against SARS-CoV-2 among COVID-19 vaccinated Bangladeshi population. This study suggests plasma IFN-γ may play a role in maintaining persistent anti-SARS-CoV-2 IgG levels, which warrants further investigation along with genetic and/or epigenetic basis to fully establish its protective nature in COVID-19 vaccination.

Renal sympathetic denervation suppresses de novo podocyte injury and albuminuria in rats with aortic regurgitation.

BACKGROUND: The presence of chronic kidney disease is a significant independent risk factor for poor prognosis in patients with chronic heart failure. However, the mechanisms and mediators underlying this interaction are poorly understood. In this study, we tested our hypothesis that chronic cardiac volume overload leads to de novo renal dysfunction by coactivating the sympathetic nervous system and renin-angiotensin system in the kidney. We also examined the therapeutic potential of renal denervation and renin-angiotensin system inhibition to suppress renal injury in chronic heart failure. METHODS AND RESULTS: Sprague-Dawley rats underwent aortic regurgitation and were treated for 6 months with vehicle, olmesartan (an angiotensin II receptor blocker), or hydralazine. At 6 months, albuminuria and glomerular podocyte injury were significantly increased in aortic regurgitation rats. These changes were associated with increased urinary angiotensinogen excretion, kidney angiotensin II and norepinephrine (NE) levels, and enhanced angiotensinogen and angiotensin type 1a receptor gene expression and oxidative stress in renal cortical tissues. Aortic regurgitation rats with renal denervation had decreased albuminuria and glomerular podocyte injury, which were associated with reduced kidney NE, angiotensinogen, angiotensin II, and oxidative stress. Renal denervation combined with olmesartan prevented podocyte injury and albuminuria induced by aortic regurgitation. CONCLUSIONS: In this chronic cardiac volume-overload animal model, activation of the sympathetic nervous system augments kidney renin-angiotensin system and oxidative stress, which act as crucial cardiorenal mediators. Renal denervation and olmesartan prevent the onset and progression of renal injury, providing new insight into the treatment of cardiorenal syndrome.

Impacts of SARS-CoV-2 on diabetes mellitus: A pre and post pandemic evaluation.

The coronavirus disease 2019 (COVID-19) pandemic caused by the novel beta coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) crippled the whole world and has resulted in large number of morbidity and mortality. The origin of the SARS-CoV-2 is still disputed. The risk of infection with SARS-CoV-2 is dependent on several risk factors as observed in many studies. The severity of the disease depends on many factors including the viral strain, host immunogenetics, environmental factors, host genetics, host nutritional status and presence of comorbidities like hypertension, diabetes, Chronic Obstructive Pulmonary Disease, cardiovascular disease, renal impairment. Diabetes is a metabolic disorder mainly characterized by hyperglycemia. Diabetic individuals are intrinsically prone to infections. SARS-CoV-2 infection in patients with diabetes result in ß-cell damage and cytokine storm. Damage to the cells impairs the equilibrium of glucose, leading to hyperglycemia. The ensuing cytokine storm causes insulin resistance, especially in the muscles and liver, which also causes a hyperglycemic state. All of these increase the severity of COVID-19. Genetics also play pivotal role in disease pathogenesis. This review article focuses from the probable sources of coronaviruses and SARS-CoV-2 to its impacts on individuals with diabetes and host genetics in pre- and post-pandemic era.

Mapping the protein binding site of the (pro)renin receptor using in silico 3D structural analysis.

We have previously reported that monoclonal antibodies against the (pro)renin receptor [(P)RR] can reduce the Wnt/ß-catenin-dependent development of pancreatic ductal adenocarcinoma (PDAC), the most common pancreatic cancer. Antibodies against two (P)RR regions (residues 47-60 and 200-213) located in the extracellular domain (ECD) reduced the proliferation of human PDAC cells in vitro. Although these regions probably participate in the activation of Wnt/ß-catenin signaling, their functional significance remains unclear. Moreover, the (P)RR ECD is predicted to possess an intrinsically disordered region (IDR), which allows multiple protein interactions because of its conformational flexibility. In this study, we investigated the significance of the two regions and the IDR by in silico 3D structural analysis using the AlphaFold2 program and evolutionary sequence conservation profile. The model showed that ECD adopted a folded domain (residues 17-269) and had an IDR (residues 270-296). The two regions mapped onto the structural model formed a continuous surface patch comprising evolutionarily conserved hydrophobic residues. The homodimeric structure predicted by AlphaFold2 showed that full-length (P)RR comprising the ECD, single-span transmembrane, and cytoplasmic domains formed a twofold symmetric dimer via the ECD, which explains the experimentally proven homodimerization. The dimer model possessed two hand-shaped grooves with residues 47-60 and 200-213 in their palms and the IDR as their fingers. Based on these findings, we propose that the IDR-containing hydrophobic grooves act as a binding site for (P)RR and perform multiple functions, including Wnt signaling activation. Antibodies against the (pro)renin receptor residues 47-60 and 200-213 can inhibit pancreatic ductal adenocarcinoma (PDAC) cell proliferation by suppressing Wnt signaling. This study provides 3D structural insights into receptor binding and one-to-many interactions, which underpin the functional versatility of this receptor.

Corrigendum to "establishing a novel assay system for measuring renin concentration using cost effective recombinant ovine angiotensinogen".

[This corrects the article DOI: 10.1016/j.heliyon.2019.e01409.].

Evaluating the seroprevalence of SARS-CoV-2 IgG in five different districts of Bangladesh. A seroepidemiological study.

BACKGROUND: We aimed to measure the seroprevalences and levels of anti-SARS-CoV-2 IgG in children, unvaccinated and vaccinated adults in five districts of Bangladesh and thus, investigate the association of seroprevalence and anti-SARS-CoV-2 IgG level with respect to different attributes of study participants. METHODS: In the present study, the seroprevalences and levels of plasma anti-SARS-CoV-2 IgG were measured in children (n = 202), unvaccinated adults (n = 112), and vaccinated adults (n = 439) using quantitative ELISA. RESULTS: The overall seroprevalence in the three groups of the study participants were 58.3% (90%CrI: 52.3-64.2%), 62.2% (90%CrI: 54.4-70.0%) and 90.7% (90%CrI: 88.3-92.9%), respectively. Multivariate logistic and linear regression revealed no significant association of seropositivity and levels of anti-SARS-CoV-2 IgG with the baseline characteristics of the children. AB blood group (vs A; aOR=0.21, 95% CI: 0.04-0.92, p = 0.04), O blood group (vs A; aOR=0.09, 95% CI: 0.02-0.32, p = 0.0004), BMI (aOR=1.61, 95% CI: 1.14-2.37, p = 0.01) and overweight obesity status (vs normal, aOR=0.12, 95% CI: 0.02-0.76, p = 0.03) were significantly associated with seropositivity in unvaccinated adults after adjusting for confounders. Age (p = 0.002) was significantly associated with anti-SARS-CoV-2 level in vaccinated adults after adjusting for confounders. Most of the children and unvaccinated adults belonged to the lower antibody response class which implicates the necessity of vaccination. CONCLUSION: This study portrays a better way of evaluating transmission of virus and gain a better understanding of the true extent of infection as illustrated by the high rates of seroprevalences in children and unvaccinated adults. The findings of this study depicted from the antibody response also suggest the importance of vaccination.

Intronic Variants of the Angiotensin-Converting Enzyme 2 Gene Modulate Plasma ACE2 Levels and Possibly Confer Protection against Severe COVID-19.

Membrane-bound angiotensin-converting enzyme 2 (ACE2) receptor acts as the entry point for the novel coronavirus, SARS-CoV-2. Polymorphisms in the ACE2 gene may alter viral binding, regulate the expression of ACE2, and thus, affect disease severity. In this study, 68 COVID-19 patients with varying degrees of severity and 40 healthy controls were enrolled. The genetic landscape of the ACE2 gene was explored by whole exome sequencing of 29 individuals, and specific regions of ACE2 were analyzed for the rest of the participants via PCR, followed by barcode-tagged sequencing. The mean soluble ACE2 level in the plasma of healthy controls and patients did not vary significantly but was higher in the patient group (3.77 ± 1.55 ng/mL vs. 3.94 ± 1.42 ng/mL). Analysis of exon 1, exon 2, and exon 8 of the ACE2 gene revealed that these regions are highly conserved in our population. Investigation of exon 11 and its flanking intronic region revealed that deletions in a stretch of 18T nucleotides in the noncoding region significantly decrease ACE2 levels in plasma, as individuals harboring wild-type variants had higher plasma ACE2 levels compared to those harboring T1del, T2del, and T3del variants. However, the intronic variants were not found to be significantly associated with disease severity.

Construction of copy number variation landscape and characterization of associated genes in a Bangladeshi cohort of neurodevelopmental disorders.

Introduction: Copy number variations (CNVs) play a critical role in the pathogenesis of neurodevelopmental disorders (NDD) among children. In this study, we aim to identify clinically relevant CNVs, genes and their phenotypic characteristics in an ethnically underrepresented homogenous population of Bangladesh. Methods: We have conducted chromosomal microarray analysis (CMA) for 212 NDD patients with male to female ratio of 2.2:1.0 to identify rare CNVs. To identify candidate genes within the rare CNVs, gene constraint metrics [i.e., "Critical-Exon Genes (CEGs)"] were applied to the population data. Autism Diagnostic Observation Schedule-Second Edition (ADOS-2) was followed in a subset of 95 NDD patients to assess the severity of autism and all statistical tests were performed using the R package. Results: Of all the samples assayed, 12.26% (26/212) and 57.08% (121/212) patients carried pathogenic and variant of uncertain significance (VOUS) CNVs, respectively. While 2.83% (6/212) patients' pathogenic CNVs were found to be located in the subtelomeric regions. Further burden test identified females are significant carriers of pathogenic CNVs compared to males (OR = 4.2; p = 0.0007). We have observed an increased number of Loss of heterozygosity (LOH) within cases with 23.85% (26/109) consanguineous parents. Our analyses on imprinting genes show, 36 LOH variants disrupting 69 unique imprinted genes and classified these variants as VOUS. ADOS-2 subset shows severe social communication deficit (p = 0.014) and overall ASD symptoms severity (p = 0.026) among the patients carrying duplication CNV compared to the CNV negative group. Candidate gene analysis identified 153 unique CEGs in pathogenic CNVs and 31 in VOUS. Of the unique genes, 18 genes were found to be in smaller (<1 MB) focal CNVs in our NDD cohort and we identified PSMC3 gene as a strong candidate gene for Autism Spectrum Disorder (ASD). Moreover, we hypothesized that KMT2B gene duplication might be associated with intellectual disability. Conclusion: Our results show the utility of CMA for precise genetic diagnosis and its integration into the diagnosis, therapy and management of NDD patients.

Acid-activated prorenin binds to (pro)renin receptor in vitro.

Binding properties of acid-activated prorenin to (pro)renin receptor [(P)RR] was investigated in vitro to discuss possible roles of such reversibly acid-activated prorenin in the renin angiotensin (RA) system. Prorenin was acidified at pH 3.3, 4.5, 5.5, 6.5, and its activation level was measured at 1, 2, 4, 8, 12, and 25 h. Prorenin, activated non-proteolytically in time- and pH-dependent manners, was verified by Western blot analyses. Acidification of prorenin for 25 h at pH 3.3, 4.5, 5.5, and 6.5 showed 78%, 54%, 34%, and 20% activities, respectively when compared with the renin activity of trypsinized prorenin as 100%. Additionally, the binding properties of acidified prorenin to (P)RR were elucidated both at the equilibrium state and in the kinetic state using BIAcore. BIAcore assay showed that acidified prorenin at pH 3.3, 4.5, 5.5, and 6.5 had apparent K(D) of 1.57 × 10(4), 14.1, 8.29, and 8.04 nM, respectively while native prorenin at pH 7.4 had a K(D) of 7.8 nM. At equilibrium state, K(D) of native prorenin was 1.42 nM whereas apparent K(D) varied from 1.25 to 5.0 nM for the prorenin acidified at pH 4.5, 5.5, and 6.5. The K(m) values of free forms of acidified prorenin at different pH (0.33-0.5 µM) was almost similar to those of (P)RR-bound forms of acidified prorenin (0.5-0.77 µM). These in vitro data indicate that prorenin acidified in vivo possibly modulate RA system in receptor-dependent and/or -independent manners which could ultimately lead to the pathogenesis of diseases.

Most frequently harboured missense variants of hACE2 across different populations exhibit varying patterns of binding interaction with spike glycoproteins of emerging SARS-CoV-2 of different lineages.

Since the emergence of SARS-CoV-2 at Wuhan in the Hubei province of China in 2019, the virus has accumulated various mutations, giving rise to many variants. According to the combinations of mutations acquired, these variants are classified into lineages and greatly differ in infectivity and transmissibility. In 2021 alone, a variant of interest (VoI) Mu (B.1.621), as well as, variants of concern (VoC) Delta (B.1.617.2) and Omicron (BA.1, BA.2) and later in 2022, BA.4, BA.5, and BA.2.12.1 have emerged. Since then, the world has seen prominent surges in the rate of infection during short periods of time. However, not all populations have suffered equally, which suggests a possible role of host genetic factors. Here, we investigated the strength of binding of the spike glycoprotein receptor-binding domain (RBD) of the SARS-CoV-2 variants: Mu, Delta, Delta Plus (AY.1), Omicron sub-variants BA.1, BA.2, BA.4, BA.5, and BA.2.12.1 with the human angiotensin-converting enzyme 2 (hACE2) missense variants prevalent in major populations. In this purpose, molecular docking analysis, as well as, molecular dynamics simulation was performed of the above-mentioned SARS-CoV-2 RBD variants with the hACE2 containing the single amino acid substitutions prevalent in African (E37K), Latin American (F40L), non-Finnish European (D355 N), and South Asian (P84T) populations, in order to predict the effects of the lineage-defining mutations of the viral variants on receptor binding. The effects of these mutations on protein stability were also explored. The protein-protein docking and molecular dynamics simulation analyses have revealed variable strength of attachment and exhibited altered interactions in the case of different hACE2-RBD complexes. In vitro studies are warranted to confirm these findings which may enable early prediction regarding the risk of transmissibility of newly emerging variants across different populations in the future.

The polymorphic landscape analysis of GATA1 exons uncovered the genetic variants associated with higher thrombocytopenia in dengue patients.

The current study elucidated an association between gene variants and thrombocytopenia through the investigation of the exonic polymorphic landscape of hematopoietic transcription factor-GATA1 gene in dengue patients. A total of 115 unrelated dengue patients with dengue fever (DF) (N = 91) and dengue hemorrhagic fever (DHF) (N = 24) were included in the study. All dengue patients were confirmed through detection of NS1 antigen, IgM, and IgG antibodies against the dengue virus. Polymerase chain reaction using specific primers amplified the exonic regions of GATA1 while Sanger sequencing and chromatogram analyses facilitated the identification of variants. Variants G>A (at chX: 48792009) and C>A (at chX: 4879118) had higher frequency out of 13 variants identified (3 annotated and 10 newly recognized). Patients carrying either nonsynonymous or synonymous variants had significantly lower mean values of platelets compared to those harboring the reference nucleotides (NC_000023.11). Further analyses revealed that the change in amino acid residue leads to the altered three-dimensional structure followed by interaction with neighboring residues. Increased stability of the protein due to substitution of serine by asparagine (S129N at chX: 48792009) may cause increased rigidity followed by reduced structural flexibility which may ultimately disturb the dimerization (an important prerequisite for GATA1 to perform its biological activity) process of the GATA1 protein. This, in turn, may affect the function of GATA1 followed by impaired production of mature platelets which may be reflected by the lower platelet counts in individuals with such variation. In summary, we have identified new variants within the GATA1 gene which were found to be clinically relevant to the outcome of dengue patients and thus, have the potential as candidate biomarkers for the determination of severity and prognosis of thrombocytopenia caused by dengue virus. However, further validation of this study in a large number of dengue patients is warranted. Trial Registration: number SLCTR/2019/037.

MNS16A VNTR polymorphism of human telomerase gene: Elucidation of a gender specific potential allele associated with type 2 diabetes in Bangladeshi population.

BACKGROUND: Type 2 diabetes (T2D) is a multifactorial disorder that affects multi-organ and can alter telomerase (encoded by hTERT gene) activity and thus, may affect telomere length. The variable number of tandem repeats MNS16A in hTERT gene facilitates extension of telomeres by regulating telomerase. In the present study, genetic analysis of MNS16A tandem repeats in hTERT gene was performed with the aim of finding out any association of allelic and genotypic variations with the risk of T2D in Bangladeshi population. METHODS: A total of unrelated 395 individuals with T2D and 247 healthy individuals were included in the study. The genotypic and allelic frequencies were determined using allele specific polymerase chain reaction. The association of allelic and genotypic frequencies with risk of T2D was analyzed using logistic regression analysis on the basis of odds ratio at 95% confidence interval. Hardy-Weinberg equilibrium (HWE) test was performed to evaluate the uniformity of the genotypic frequencies and deviation from the HWE was tested using Chi-square test. RESULTS: Logistic regression analyses revealed significant association of short allele containing 243 bp (OR: 1.37 and p = 0.03) with T2D, when the long alleles (commonly found) were considered as reference. The heterozygous genotype 272/302 was significantly associated with the decreased risk of T2D (OR: 0.33, p = 0.001). The combined results of genotypes indicated that the MNS16A polymorphism was significantly associated with the increased risk of T2D under the dominant model (LL vs SL + SS; OR: 2.62, p < 0.0001). Interestingly, short allele 243 was associated with the risk of disease only in male population (OR: 1.62, p = 0.02). The genotype 272/302 was also found to be associated with the decreased risk of T2D when respective data for male was analyzed individually. CONCLUSIONS: We have identified four variable number of tandem repeats with varying patterns of association with T2D in Bangladeshi population and to extend our knowledge of understanding regarding these VNTRs, further large-scale studies are warranted.