Elizabeth Claire Akam

Biochemical and pharmacological characterization of AZD1981, an orally available selective DP2 antagonist in clinical development for asthma.

The discovery of DP2 as a second receptor for PGD2 has prompted the search for antagonists as potential novel therapies based on the associations between PGD2 and disease. Here we describe the biochemical and pharmacological properties of 4‐(acetylamino)‐3‐[(4‐chlorophenyl)thio]‐2‐methyl‐1H‐indole‐1‐acetic acid (AZD1981), a novel DP2 receptor antagonist.

Switching between agonists and antagonists at CRTh2 in a series of highly potent and selective biaryl phenoxyacetic acids

A novel series of biaryl phenoxyacetic acids was discovered as potent, selective antagonists of the chemoattractant receptor-homologous expressed on Th2 lymphocytes receptor (CRTh2 or DP2). A hit compound 4 was discovered from high throughput screening. Modulation of multiple aryl substituents afforded both agonists and antagonists, with small changes often reversing the mode of action. Understanding the complex SAR allowed design of potent antagonists such as potential candidate 34.

The effect of chronic high insulin exposure upon metabolic and myogenic markers in C2C12 skeletal muscle cells and myotubes.

Skeletal muscle is an insulin sensitive tissue and accounts for approximately 80% of post‐prandial glucose disposal. This study describes the effects of insulin, delivered for 72 h, to skeletal muscle myoblasts during differentiation or to skeletal muscle myotubes. After chronic treatment, cultures were acutely stimulated with insulin and analyzed for total and phosphorylated Akt (Ser473), mRNA expression of metabolic and myogenic markers and insulin‐stimulated glucose uptake. Skeletal muscle cells differentiated in the presence of insulin chronically, reduced acute insulin stimulated phosphorylation of Akt Ser473. In addition, there was a reduction in mRNA expression of Hexokinase II (HKII), GLUT4 and PGC‐1α. Insulin‐stimulated glucose uptake was attenuated when cells were differentiated in the presence of insulin. In contrast, myotubes exposed to chronic insulin showed no alterations in phosphorylation of Akt Ser473. Both HKII and GLUT4 mRNA expression were reduced by chronic exposure to insulin; while PGC‐1α was not different between culture conditions and was increased by acute insulin stimulation. These data suggest that there are differential responses in insulin signalling, transcription, and glucose uptake of skeletal muscle cells when cultured in either the presence of insulin during differentiation or in myotube cultures.

Genetic analysis of novel Alu insertion polymorphisms in selected indian populations

Indian subpopulations (Chenchu, Koya, and Lobana Sikh) were analyzed at the genetic level for 12 Alu polymorphisms. These markers were then utilized to establish levels of genetic identity between the Indian populations and more widely between the Indian populations and a European population.

Genetic analysis of CYP2D6 polymorphism in Indian populations and its pharmacogenetic implications

Despite the rapid development of pharmacogenetic testing and the frequencies of medication related emergencies increasing, pharmacogentic testing is not yet implemented extensively in clinical practice. Several studies document that polymorphic Cytochrome P450 isoenzymes CYP2C9, CYP2C19 and CYP2D6 are responsible for the metabolism of many clinically important drugs and xenobiotics. These polymorphisms contribute to inter-individual and interethnic variation in drug metabolism which may lead to differences in drug response, suggesting that common dose regimen will not always equivocate to efficacious dosing. The CYP2D6*2, CYP2D6*4 and CYP2D6*10 variants were studied in four Indian populations (Gujarati, Punjabi, Bengali and Koya tribe). Genotypes at individual alleles were identified using Polymerase Chain Reaction Restriction Fragment Length Polymorphism (PCR-RFLP) method. Differences in frequencies of CYP2D6 genotypes/ alleles were compared at regional and global level. CYP2D6*2 variant frequency was highest among Gujarati population (47%) Gujarati and Punjabi populations showed high levels of CYP2D6*4 (13% and 24% respectively), whilst high levels of CYP2D6*10 were found in Bengali and Koya populations (21% and 12% respectively). At genotypic level, CYP2D6 *4/*4 genotype was absent in all study populations, resulting in the absence of the PM (poor metaboliser) phenotype in these samples. Overall there are significant differences among Indian populations at this locus. Overall observed allele frequency spectrum fits well into other Indian and European populations. There are significant differences in CYP2D6 allele and genotype frequencies in 4 populations leading to differential estimates of EM and IM. These results suggest the importance of delivering pharmacotherapeutic regimes for patients on the basis of their genetic profile.

Genetic Analysis of Common Variants of MMPs and their Involvement in Rheumatoid Arthritis in the East Midlands, UK

Introduction: Rheumatoid arthritis (RA) affects around 1% of population and causes irreversible synovial joint damage and bone erosion. Matrix metalloproteinases (MMPs) play a role in pathologic processes; however their involvement in RA is not clear. This study investigated the association of MMP2, MMP7 and MMP9 with RA. Methods: DNA samples from European (103 controls, 125 patients) and South Asian (91 controls, 115 patients) populations were genotyped for MMP7 (rs11568818), MMP9 (rs17576) and MMP2 (rs2241145). Diplotype and triplotypes analyses were performed. Results: An individual is twice as likely to develop RA if they have an AG genotype at both the MMP9 and MMP7 loci in European (OR 2.2, CI 1.03-4.70) or South Asian population (OR 2.28, CI 1.00-5.20). A CG genotype at the MMP2 locus and AG at MMP9- 836 gives protection within a European population (OR 0.34, CI 0.17-0.70). Heterozygous genotype combination on all three loci in South Asians increases risk of RA by three times (OR 3.27, CI 1.04-10.20). South Asians showed a significant doubling of RA risk with a total genetic risk score of three or more. Conclusion: Our results show that polymorphisms at these three MMP loci impact RA susceptibility and have a synergetic effect.

Association of methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms with coronary artery disease (CAD) in a North Indian population

Abstract There is significant variation in reported associations of the MTHFR C677T (rs1801133) and A1298C (rs1801131) polymorphisms and coronary artery disease (CAD) in different global populations. This study aims to identify any individual or combined associations between the 1298 and 677 loci of MTHFR and CAD in a North Indian population. A total of 159 patients and 166 controls were genotyped using validated TaqMan assays. Odds ratio analysis identified associations at crude level and multiple logistic regression controlled for confounding variables. Linkage disequilibrium between the loci was assessed along with haplotype association analysis. At the C677T locus, homozygosity of the T allele identified a significantly protective association (OR = 0.38, CI: 0.24–0.60). For the A1298C locus the AC genotype had a protective effect in codominant model (OR = 0.53, CI: 0.32–0.85) and CC genotype showed a susceptible association in recessive model when controlled for age, sex and lipids (OR = 2.70, CI: 1.27–5.77). This study identified that, independently, both heterozygous genotypes show a protective association with CAD. In addition the CC genotype of A1298C in recessive model was a susceptible genotype. The combined associations of MTHFR are protective (primarily due to the effects of C677T locus) suggesting an interaction between the loci and their associations with CAD within this sample.

The Role of TLR4, TNF-α and IL-1β in Type 2 Diabetes Mellitus Development within a North Indian Population: Inflammatory gene polymorphisms and type 2 diabetes mellitus

This study investigated the role of IL‐1β‐511 (rs16944), TLR4‐896 (rs4986790) and TNF‐α‐308 (rs1800629) polymorphisms in type 2 diabetes mellitus (T2DM) among an endogamous Northern Indian population. Four hundred fourteen participants (204 T2DM patients and 210 nondiabetic controls) were genotyped for IL‐1β‐511, TLR4‐896 and TNF‐α‐308 loci. The C allele of IL‐1β‐511 was shown to increase T2DM susceptibility by 75% (OR: 1.75 [CI 1.32–2.33]). Having two parents affected by T2DM increased susceptibility by 5.7 times (OR: 5.693 [CI 1.431–22.648]). In this study, we have demonstrated a conclusive association with IL‐1β‐511 locus and IL‐1β‐511‐TLR4‐896 diplotype (CC‐AA) and T2DM, which warrants further comprehensive analyses in larger cohorts.