Association of CYP1A2 and GST gene variants with asthma in cases presenting with allergic chronic rhinosinusitis

Background

Inter-individual differences in regulation and activity of xenobiotic metabolizing enzymes (XMEs) CYP1A and GST might cause distinct susceptibility to chronic rhinosinusitis (CRS) phenotypes that need to be explored. Therefore, the present study aimed to evaluate the role and risk of CYP1A and GST gene variants in allergic CRS subjects with and without asthma. A total of 224 allergic CRS cases with asthma, 252 allergic CRS cases without asthma, and 350 healthy control subjects were subjected to genetic analysis. Gene variants of cytochrome P450 (CYP1A1 T3801 rs4646903, A2455G rs1048943, C2453A rs1799814 and CYP1A2 G3858A rs2069514, T739G rs2069526, C163A rs762551) and glutathione S-transferase P (GSTP1 A313G rs1605 & C341T rs1799811) were investigated by polymerase chain reaction-restriction fragment length polymorphism and GSTM1null, and GSTT1null by multiplex PCR methods.

Results

TG genotype of CYP1A2 rs2069526 (OR 1.73, 95% CI 1.20–2.50, p < 0.002), TC genotype of CYP1A1 rs4646903 (OR 1.43, 95% CI 1.03–1.98, p < 0.031) and GSTM1del (OR 1.87, 95% CI 1.24–2.81, p < 0.003) and were found to be significantly associated with only allergic CRS cases. CYP1A2 rs2069526 (OR 2.33, 95% CI 1.61–3.37, p < 0.001), GG genotype of GSTP1 rs1605 (OR 4.75, 95% CI 2.62–8.63, p < 0.001), GSTM1del (OR 1.82, 95% CI 1.19–2.78, p < 0.006), GSTM1/GSTT1 double null (OR 2.58, 95% CI 1.36–4.87, p < 0.004) and were found to be significantly associated with asthma in allergic CRS cases. Further, G-G-C haplotype of CYP1A2 rs2069514, rs2069526 and rs762551 gene variants was found to increase the risk for asthma by 5 folds in allergic CRS subjects (OR 5.53, 95% CI 1.76–17.31, p < 0.003) while T-G-C haplotype of CYP1A1 rs4646903, rs1048943, rs1799814 (OR 0.11, 95% CI (0.01–0.95, p < 0.045) and A-T haplotype of GSTP1 rs1605, rs1799811 (OR 0.27, 95% CI (0.08–0.89, p < 0.032) showed protective effect in allergic CRS group.

Conclusion

The present study reports the significantly increased association of CYP1A2, GSTM, and GSTP gene variants with asthma in allergic CRS.

Interaction between Maternal and Paternal SHMT1 C1420T Predisposes to Neural Tube Defects in the Fetus: Evidence from Case-Control and Family-Based Triad Approaches

BACKGROUND

Neural tube defects (NTDs) are caused by the failure of neural tube formation which occurs during early embryonic development. NTDs are the most severe and leading cause of fetal mortality. Serine hydroxymethyl transferase (SHMT1) provides one-carbon units necessary for embryogenesis and defects in one-carbon production result in specific pathological conditions during pregnancy. The present study is aimed to evaluate the association of SHMT1 C1420T with NTD risk in the fetus using fetal, maternal and paternal groups by applying both case-control and family-based triad approaches.

METHODS

A total of 924 subjects including 124 NTD case-parent trios (n = 124 × 3 = 372) and 184 healthy control-parent trios (n = 184 × 3 = 552) from Telangana State, South India were analyzed. DNA from umbilical cord tissues and parental blood samples were extracted, and genotyped by polymerase chain reaction-restriction fragment length polymorphism. Statistical analysis used were SPSS, parent-of-origin effect (POE) analysis.

RESULTS

Case-control study design demonstrated fetuses with homozygous variant genotype (TT) to be at risk toward spina bifida subtype (p = 0.022). Among parents, fathers with TT genotype were associated with anencephaly (p = 0.018) and spina bifida subtypes (p = 0.027) in the offspring. Of interest, maternal-paternal-offspring genotype incompatibility revealed maternal CT genotype in combination with paternal TT genotype increased risk for NTDs in the fetus (CTxTT = TT; p = 0.021). Family-based parent-of-origin effect linkage analysis revealed significant maternal over-transmission of variant allele to NTD fetuses (p < 0.01).

CONCLUSION

The present study, using both case-control and family-based triad approach is the first report to demonstrate parental association of SHMT1 C1420T variant in conferring NTD risk in the fetus. Birth Defects Research 109:1020-1029, 2017. © 2017 Wiley Periodicals, Inc.

Identification of Small Molecule as a High Affinity &#946;2 Agonist Promiscuously Targeting Wild and Mutated (Thr164Ile) &#946; 2 Adrenergic Receptor in the Treatment of Bronchial Asthma

BACKGROUND

A subset of asthmatics shows refractoriness to Salbutamol owing to ADRB2 gene C.T polymorphism (rs 1800888) that substitutes Thr to Ile at the position 164 in the β2 adrenergic receptor leading to sub-optimal binding of Salbutamol. The present study aims to associate the Salbutamol (200 mcg) refractoriness with the polymorphism and select the best existing agonist with optimal binding affinity against wild and mutated receptor and further identify high affinity compound, irrespectively targeting wild and mutated receptor through virtual screening methods.

METHODS

Responders to Salbutamol were categorized, if percentage reversibility was greater than or equal to 12% in them, while those showing reversibility less than 12% were non-responders. The genotyping for polymorphism was performed by ARMS PCR method. Established agonists with consistent binding affinity against wild and mutated receptors formed query compound to identify high affinity molecule from Phase database through 7 point pharmacophore based screening.

RESULTS

Polymorphism was significantly associated with non-responders (p= < 0.05) demonstrating it as a major factor of Salbutamol refractoriness. Results from Glide Docking showed that Fenoterol had highest affinity for mutated receptor and stood as second best (after Salbutamol) high affinity agonist for wild receptor among the established β2 agonists. Therefore Fenoterol formed a query molecule (7 point pharmacophore) in identification of high affinity compound for virtual screening process.

CONCLUSION

Compound CACPD2011a-0001278239 identified through virtual screening against 4 million compounds in phase database was shown to irrespectively target both wild and mutated β2 adrenergic receptor with high and consistent affinity which was par greater than established β2agonists.

Interaction between Maternal and Paternal SHMT1 C1420T Predisposes to Neural Tube Defects in the Fetus: Evidence from Case-Control and Family-Based Triad Approaches

BACKGROUND

Neural tube defects (NTDs) are caused by the failure of neural tube formation which occurs during early embryonic development. NTDs are the most severe and leading cause of fetal mortality. Serine hydroxymethyl transferase (SHMT1) provides one-carbon units necessary for embryogenesis and defects in one-carbon production result in specific pathological conditions during pregnancy. The present study is aimed to evaluate the association of SHMT1 C1420T with NTD risk in the fetus using fetal, maternal and paternal groups by applying both case-control and family-based triad approaches.

METHODS

A total of 924 subjects including 124 NTD case-parent trios (n = 124 × 3 = 372) and 184 healthy control-parent trios (n = 184 × 3 = 552) from Telangana State, South India were analyzed. DNA from umbilical cord tissues and parental blood samples were extracted, and genotyped by polymerase chain reaction-restriction fragment length polymorphism. Statistical analysis used were SPSS, parent-of-origin effect (POE) analysis.

RESULTS

Case-control study design demonstrated fetuses with homozygous variant genotype (TT) to be at risk toward spina bifida subtype (p = 0.022). Among parents, fathers with TT genotype were associated with anencephaly (p = 0.018) and spina bifida subtypes (p = 0.027) in the offspring. Of interest, maternal-paternal-offspring genotype incompatibility revealed maternal CT genotype in combination with paternal TT genotype increased risk for NTDs in the fetus (CTxTT = TT; p = 0.021). Family-based parent-of-origin effect linkage analysis revealed significant maternal over-transmission of variant allele to NTD fetuses (p < 0.01).

CONCLUSION

The present study, using both case-control and family-based triad approach is the first report to demonstrate parental association of SHMT1 C1420T variant in conferring NTD risk in the fetus. Birth Defects Research, 2017. © 2017 Wiley Periodicals, Inc.

Analysis of ADRB2 (Arg16Gly) Gene Variant with Susceptibility, Pharmacogenetic Response and Disease Severity in South Indian Asthmatics

β2-Adrenergic receptor (β2-AR) plays a crucial role in asthma pathophysiology by regulating, processes of the lung function, and clinical response to bronchodilators. The +46G>A- Gly16Arg polymorphism in the gene encoding β2 adrenergic receptor (ADRB2) has been associated with receptor non-responsiveness after β2-agonist exposure. In the present study, we sought to evaluate the possible association of Gly16Arg polymorphism with asthma susceptibility, pharmacogenetic response to Salbutamol, and varying degrees of disease severity. Three hundred ninety-eight clinically diagnosed patients and 456 healthy controls were enrolled for the study. Patients were classified into severity classes according to Global Initiative for Asthma guidelines. To assess bronchodilator response, spirometry was performed before and 15 min after Salbutamol (200 μg) delivery. Responders to Salbutamol were categorized if percentage reversibility was greater than or equal to 12% in them, while those showing reversibility less than 12% were classified as non-responders. Genotyping was carried out by ARMS-PCR technique. Statistical methods were applied to test for the significance of the results. In the present study, there was lack of significant association of polymorphism with disease susceptibility as well as with bronchodilator response. The polymorphism was not associated with mild and moderate asthma subtypes; however, there was a notable association with severe asthma subtype. In addition, the polymorphism was associated with severe asthma compared to subtypes of mild and moderate asthma combined. In a South Indian population, the ADRB2 Arg/Gly may not form a susceptible variant to develop asthma nor can be a standard predictive marker to bronchodilator response; nevertheless, the patterns in asthma severity can be predicted by analyzing this variant.

Association of Beta 2 adrenergic receptor (Thr164Ile) polymorphism with Salbutamol refractoriness in severe asthmatics from Indian population

BACKGROUND

Thr164Ile polymorphism in the ADRB2 gene encoding β2 adrenergic receptor (β2AR) has its functional consequence in declining ligand-receptor interactions and depressed coupling of β2AR to adenylcyclase. In the present study, we sought to evaluate the possible association of Thr164Ile polymorphism with asthma susceptibility, pharmacogenetic response to Salbutamol and varying degrees of severity.

METHODS

Three hundred and ninety eight clinically diagnosed patients and four hundred and fifty six healthy controls were enrolled in the study. Patients were classified into severity classes according to the Global Initiative for Asthma (GINA) guidelines. To assess bronchodilator response, spirometry was performed before and 15min after Salbutamol (200μg) delivery. Responders to Salbutamol were categorized if percentage reversibility was greater than or equal to 12% in them, while those showing reversibility <12% were classified as non-responders. Further, responding phenotypes were stratified into severity groups. Genotyping was carried out by ARMS-PCR technique. Statistical methods were applied to test the significance of the results.

RESULTS

In the present study, polymorphism was not associated with disease susceptibility however; there was significant association with non-responding asthmatics. In case of severity subsets, the polymorphism was not associated with milder subtypes; although, notable association was observed with moderate and severe asthma subtypes. In addition, the polymorphism was significantly associated with non-responding patients with severe asthma.

CONCLUSIONS

In south Indian population, the ADRB2 Thr164Ile polymorphism may not form susceptible variant to develop asthma, however, it can form a predictive maker for bronchodilator (Salbutamol) response in severe asthmatics.

Identification of high affinity bioactive Salbutamol conformer directed against mutated (Thr164Ile) beta 2 adrenergic receptor

Salbutamol forms an important and widely administered β2 agonist prescribed in the symptomatic treatment of bronchial asthma. Unfortunately, a subset of patients show refractoriness to it owing to ADRB2 gene variant (rs 1800888). The variant substitutes Thr to Ile at the position 164 in the β2 adrenergic receptor leading to sub-optimal binding of agonists. The present study aims to associate the Salbutamol response with the variant and select the bioactive conformer of Sabutamol with optimal binding affinity against mutated receptor by in silico approaches. To assess bronchodilator response spirometry was performed before and 15 min after Salbutamol (200 mcg) inhalation. Responders to Salbutamol were categorized if percentage reversibility was greater than or equal to 12%, while those showing FEV₁ reversibility less than 12% were classified as non-responders. Among the 344 subjects screened, 238 were responders and 106 were non-responders. The frequency of mutant allele "T" was significantly higher in case of non-responders (p < 0.05). In silico process involved generation of Salbutamol conformer ensembles supported by systematic search algorithm. 4369 conformers were generated of which only 1882 were considered bioactive conformers (threshold RMSD≤1 in reference to normalized structure of salbutamol). All the bioactive conformers were evaluated for the binding affinity against (Thr164 Ile) receptor through MolDock aided docking algorithm. One of the bioactive conformer (P.E. = -57.0038, RMSD = 0.6) demonstrated 1.54 folds greater affinity than the normal Salbutamol in the mutated receptor. The conformer identified in the present study may be put to pharmacodynamic and pharmacokinetic studies in future ahead.

Computer aided identification of sodium channel blockers in the clinical treatment of epilepsy using molecular docking tools

Phenytoin (PHT) and Carbamazepine (CBZ) are excellent sodium channel blockers administered in clinical treatment of epileptic seizures. However, the narrow therapeutic range and limited pharmacokinetics of these drugs have raised serious concerns in the proper management of epilepsy. To overcome this, the present study attempts to identify a candidate molecule with superior pharmacological profile than PHT and CBZ through In silico approaches. PHT and CBZ served as query small molecules for Tanimoto based similarity search with a threshold of 95% against PubChem database. Aided by MolDock algorithm, high affinity similar compound against each query was retrieved. PHT and CBZ and their respective similar were further tested for toxicity profiles, LC 50 values and biological activity. Compounds, NSC403438 and AGN-PC-0BPCBP respectively similar to PHT and CBZ demonstrated higher affinity to sodium channel protein than their respective leads. Of particular relevance, NSC403438 demonstrated highest binding affinity bestowed with least toxicity, better LC 50 values and optimal bioactivity. NSC403438 was further mapped for its structure based pharmacophoric features. In the study, we report NSC403438 as potential sodium channel blocker as a better candidate than PHT and CBZ which can be put forth for pharmacodynamic and pharmacokinetic studies.

ABBREVIATIONS

AEDs - Antiepileptic drugs, BLAST - Basic Local Alignment Search Tool, CBZ - Carbamazepine, GEFS+ - Generalized Epilepsy with Febrile Seizures Plus, GPCR - G Protein Coupled Receptor, Nav - Sodium channel with specific voltage conduction, PDB - Protein Data Bank, PHT - Phenytoin, PIR - Protein Information resources, SAVES - Structural Analysis and Verification Server, VGSC - Voltage-gated Sodium channels.

Role of interstitial collagenase gene promoter polymorphism in the etiology of gastric cancer

BACKGROUND/AIMS

Gastric cancer (GC) is a multifactorial disorder mediated by genetic, epigenetic, and environmental risk factors. GC is the most common cancer in India and it is the third prominent cause of cancer death worldwide. A single nucleotide polymorphism (SNP) in the promoter region of interstitial collagenase (MMP-1) gene appears to have an impact on the transcriptional activity and regulation of its expression. Hence, the present study is aimed to evaluate the role of interstitial collagenase gene-1607 1G/2G (rs1799750) promoter polymorphism in the etiology of GC.

PATIENTS AND METHODS

The study included 166 GC patients and 202 control subjects. Genomic DNA was isolated from whole blood samples of the subjects, and the genotyping of interstitial collagenase promoter polymorphism was carried out by polymerase chain reaction-restriction fragment length polymorphism method followed by agarose gel electrophoresis. Appropriate statistical methods were applied to test the significance of the results.

RESULTS

The risk factor profile of the patients revealed that male gender, age above 50 years, addiction to alcohol and smoking were the most common risk factors (P < 0.05). There was a significant difference in the distribution of 2G/2G genotype (2G/2G vs. 1G/1G, P = 0.016) and 1G/2G genotype (2G/2G + 1G/2G vs. 1G/1G, P = 0.010) in patient group compared with that of the control subjects.

CONCLUSION

The present study provides indirect evidence for the role of interstitial collagenase gene 1G/2G promoter polymorphism in the etiology of GC in South Indian population.

Immunotherapeutic approach for better management of cancer--role of IL-18

Interleukin-18 (IL-18) is an immune-stimulatory cytokine with antitumor activity in preclinical models. It plays pivotal roles in linking inflammatory immune responses and tumor progression and is a useful candidate in gene therapy of lymphoma or lymphoid leukemia. A phase I study of recombinant human IL-18 (rhIL-18) in patients with advanced cancer concluded that rhIL-18 can be safely given in biologically active doses to patients with advanced cancer. Some viruses can induce the secretion of IL-18 for immune evasion. The individual cytokine activity might be potentiated or inhibited by combinations of cytokines. Here we focus on combinational effects of cytokines with IL-18 in cancer progression. IL-18 is an important non-invasive marker suspected of contributing to metastasis. Serum IL-18 may a useful biological marker as independent prognostic factor of survival. In this review we cover roles of IL-18 in immune evasion, metastasis and angiogenesis, applications for chemotherapy and prognostic or diagnostic significance.

Role of proteases and antiprotease in the etiology of chronic pancreatitis

BACKGROUND/AIM

Chronic pancreatitis (CP) is the progressive and irreversible destruction of the pancreas characterized by the permanent loss of endocrine and exocrine function. Trypsin, the most important digestive enzyme plays a central role in the regulation of all other digestive enzymes. Chymotrypsin, an endopeptidase hydrolyzes peptides at amino acids with aromatic side chains. Alpha-1-antitrypsin is a principal antiprotease which protects the mucosal tissue from the proteolytic effects of trypsin and chymotrypsin by the formation of molar complexes. The present study is aimed at examining the role of proteases (trypsin and chymotrypsin) and anti-protease (α1-anti-trypsin) in the etiopathogenesis of chronic pancreatitis.

PATIENTS AND METHODS

A total of 90 CP patients and 110 age and sex matched controls were considered for the study. Serum trypsin, chymotrypsin and α1-anti-trypsin levels were determined prospectively in CP patients and compared to healthy controls as described previously.

RESULTS

The mean activity of trypsin were found to be increased in CP patients (X ± SD = 0.82 ± 0.838) in comparison to normal control group (X ± SD = 0.55 ± 0.328), (P = 0.001). Chymotrypsin activity were also found to be elevated in CP patients (X ± SD = 0.63 ± 0.278) in comparison to control group (X ± SD = 0.39 ± 0.295), (P = 0.0001). The mean α-1-anti-trypsin activity were found to be lowered in CP patients (X ± SD = 0.42 ± 0.494) in comparison to control group (X ± SD = 0.67 ± 0.465), with the variation being significant (P = 0.0003).

CONCLUSION

The findings suggest an imbalance in the synthesis and degradation of proteolytic enzymes and antiprotease indicating an altered aggressive and defensive role in the pathogenesis of chronic pancreatitis.

Mutational analysis of JAG1 gene in non-syndromic tetralogy of Fallot children

BACKGROUND

JAG1 is an evolutionarily conserved ligand for Notch receptor and functions in the cell fate decisions, cell-cell interactions throughout the development of heart especially right heart development. Tetralogy of Fallot (TOF) is essentially a right sided heart disease with characteristic features of ventricular septal defect, right ventricular outflow tract obstruction, aortic dextroposition and right ventricular hypertrophy. Hence, the present study was investigated to identify mutations of JAG1 gene in an Indian cohort of patients with TOF.

METHODS

The clinical data and blood samples from 84 unrelated subjects with TOF were collected and evaluated in comparison with 87 healthy individuals. PCR based single strand conformation polymorphism analysis and subsequent bidirectional DNA sequencing of conformers was carried in the exon 6 of JAG1 gene.

RESULTS

The DNA sequences aligned with NCBI-BLAST led to the identification of four novel variations including one nonsense 765 C>A, two missense 814 G>T, 834 G>T; and one silent alteration 816 G>T in TOF patients. The protein structure of JAG1 predicts that these variations effect first and second epidermal growth factor like repeat and might disturb ligand-receptor binding ability. The presence of similar variations was not observed in healthy controls. The software CLUSTAL-W showed the inter species conservation of altered amino acids in missense mutations.

CONCLUSION

Disease-associating novel JAG1 gene variations were found in TOF patients, and seem to play an important role in the causation of the disease.

Association of estrogen receptor alpha gene polymorphisms with BMD and their affect on estradiol levels in pre- and postmenopausal women in south Indian population from Andhra Pradesh

BACKGROUND

Osteoporosis is a multifactorial disorder with a strong genetic component and ESR1 is suggested as a candidate gene for osteoporosis. Therefore the present study is aimed to investigate the role of ESR1 gene polymorphisms and its influence on estradiol levels and BMD in osteoporotic women of Indian ethnicity.

METHODS

Four-hundred twenty-seven osteoporotic women and 460 age matched controls were included in the study. ESR1 gene polymorphism was assessed by PCR-RFLP method. Serum estradiol was measured by ELISA.

RESULTS

The frequency of pp and xx genotypes as well as p and x alleles was significantly high in pre- and postmenopausal osteoporotics when compared to controls (p<0.001). They had low BMD and estradiol levels in comparison with PP and XX genotype individuals (p<0.05).

CONCLUSION

The ESR1 gene is associated with low bone mass and low estradiol levels in all our study subjects. It is likely that the allele exerts its influence on the bone in early adulthood leading to an increased risk of osteoporosis later in life.