Genetic analysis of pharmacogenomic VIP variants in the Wa population from Yunnan Province of China

Pharmacogenomic and Pharmacomicrobiomic Aspects of Drugs of Abuse

BACKGROUND/OBJECTIVES

This review examines the role of pharmacogenomics in individual responses to the pharmacotherapy of various drugs of abuse, including alcohol, cocaine, and opioids, to identify genetic variants that contribute to variability in substance use disorder treatment outcomes. In addition, it explores the pharmacomicrobiomic aspects of substance use, highlighting the impact of the gut microbiome on bioavailability, drug metabolism, pharmacodynamics, and pharmacokinetics.

RESULTS

Research on pharmacogenetics has identified several promising genetic variants that may contribute to the individual variability in responses to existing pharmacotherapies for substance addiction. However, the interpretation of these findings remains limited. It is estimated that genetic factors may account for 20-95% of the variability in individual drug responses. Therefore, genetic factors alone cannot fully explain the differences in drug responses, and factors such as gut microbiome diversity may also play a significant role. Drug microbial biotransformation is produced by microbial exoenzymes that convert low molecular weight organic compounds into analogous compounds by oxidation, reduction, hydrolysis, condensation, isomerization, unsaturation, or by the introduction of heteroatoms. Despite significant advances in pharmacomicrobiomics, challenges persist including the lack of standardized methodologies, inter-individual variability, limited understanding of drug biotransformation mechanisms, and the need for large-scale validation studies to develop microbiota-based biomarkers for clinical use.

CONCLUSIONS

Progress in the pharmacogenomics of substance use disorders has provided biological insights into the pharmacological needs associated with common genetic variants in drug-metabolizing enzymes. The gut microbiome and its metabolites play a pivotal role in various stages of drug addiction including seeking, reward, and biotransformation. Therefore, integrating pharmacogenomics with pharmacomicrobiomics will form a crucial foundation for significant advances in precision and personalized medicine.

Pharmacogenetics of angiotensin-converting enzyme inhibitors (ACEI) and angiotensin II receptor blockers (ARB) in cardiovascular diseases

Cardiovascular diseases (CVDs) have a high mortality rate, and despite the several available therapeutic targets, non-response to antihypertensives remains a common problem. Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) are important classes of drugs recommended as first-line therapy for several CVDs. However, response to ACEIs and ARBs varies among treated patients. Pharmacogenomics assesses how an individual's genetic characteristics affect their likely response to drug therapy. Currently, numerous studies suggest that genetic polymorphisms may contribute to variability in drug response. Moreover, further studies evaluating gene-gene interactions within signaling pathways in response to antihypertensives might help to unravel potential genetic predictors for antihypertensive response. This review summarizes the pharmacogenetic data for ACEIs and ARBs in patients with CVD, and discusses the potential pharmacogenetics of these classes of antihypertensives in clinical practice. However, replication studies in different populations are needed. In addition, studies that evaluate gene-gene interactions that share signaling pathways in the response to antihypertensive drugs might facilitate the discovery of genetic predictors for antihypertensive response.

Genetic Variability of CYP4F2, CYP2D6, CYP2E1, and ACE in the Chinese Yi Population

Genetic polymorphisms of very important pharmacogenes (VIP) are a significant factor contributing to inter-individual variability in drug therapy. The purpose of this study was to identify significantly different loci in the Yi population and to enrich their pharmacogenomic information. 54 VIP variants were selected from the Pharmacogenomics Knowledge Base (PharmGKB) and genotyped in 200 Yi individuals. Then, we compared their genotype distribution between the Yi population and the other 26 populations using the χ2 test. Compared with the other 26 populations, the genotype frequencies of 4 single nucleotide polymorphisms (SNPs), rs2108622 (CYP4F2), rs1065852 (CYP2D6), rs2070676 (CYP2E1), and rs4291 (ACE), had significant differences in the Yi population. For example, the TT genotype frequency of rs2108622 (8.1%) was higher than that of African populations, and the AA genotype frequency of rs1065852 (27.3%) was higher than that of other populations except East Asians. We also found that the Yi populations differed the least from East Asians and the most from Africans. Furthermore, the differences in these variants might be related to the effectiveness and toxicity risk of using warfarin, iloperidone, cisplatin cyclophosphamide, and other drugs in the Yi population. Our data complement the pharmacogenomic information of the Yi population and provide theoretical guidance for their personalized treatment.

The landscape of very important pharmacogenes variants and potential clinical relevance in the Chinese Jingpo population: a comparative study with worldwide populations

BACKGROUND

Pharmacogenomics is a facet of personalized medicine that explores how genetic variants affect drug metabolism and adverse drug reactions. Therefore, this study aims to detect distinct pharmacogenomic variations among the Jingpo population and explore their clinical correlation with drug metabolism and toxicity.

METHODS

Agena MassARRAY Assay was used to genotype 57 VIP variants in 28 genes from 159 unrelated Jingpo participants. Subsequently, the chi-squared test and Bonferroni's statistical tests were utilized to conduct a comparative analysis of genotypes and allele frequencies between the Jingpo population and the other 26 populations from the 1000 Genome Project.

RESULTS

We discovered that the KHV (Kinh in Ho ChiMinh City, Vietnam), CHS (Southern Han Chi-nese, China) and JPT (Japanese in Tokyo, Japan) exhibited the smallest differences from the Jingpo with only 4 variants, while ESN (Esan in Nigeria) exhibited the largest differences with 30 variants. Besides, a total of six considerably different loci (rs4291 in ACE, rs20417 in PTGS2, rs1801280 and rs1799929 in NAT2, rs2115819 in ALOX5, rs1065852 in CYP2D6, p < 3.37 × 10-5) were identified in this study. According to PharmGKB, rs20417 (PTGS2), rs4291 (ACE), rs2115819 (ALOX5) and rs1065852 (CYP2D6) were found to be associated with the metabolism efficiency of non-steroidal anti-inflammatory drugs (NSAIDs), aspirin, montelukast and tamoxifen, respectively. Meanwhile, rs1801280 and rs1799929 (NAT2) were found to be related to drug poisoning with slow acetylation.

CONCLUSION

Our study unveils distinct pharmacogenomic variants in the Jingpo population and discovers their association with the metabolic efficiency of NSAIDs, montelukast, and tamoxifen.

Single nucleotide polymorphism (SNP) rs4291 of the angiotensin-converting enzyme (ACE) gene is associated with the response to losartan treatment in hypertensive patients

Arterial hypertension is characterized by systolic pressure ≥ 140 mmHg and/or diastolic pressure ≥ 90 mmHg and its treatment consists of the use of antihypertensive drugs, as losartan and hydrochlorothiazide. Blood pressure is regulated by angiotensin-converting enzyme (ACE) and polymorphisms in the ACE gene are associated to a greater predisposition to hypertension and response to treatment. The aim of this study was to evaluate the association of genetic polymorphisms of ACE rs4363, rs4291 and rs4335 and the response to antihypertensive drugs in hypertensive patients from Ouro Preto/MG, Brazil. A case-control study was carried out with 87 hypertensive patients being treated with losartan and 75 with hydrochlorothiazide, who answered a questionnaire and had blood samples collected. Biochemical analyzes were performed on serum using UV/Vis spectrophotometry and identification of ACE variants rs4363, rs4291 and rs4335 was performed by real-time PCR using the TaqMan® system. Univariate logistic regression test was performed to compare categorical data in STATA 13.0 software. The results showed that there was an influence of ACE polymorphisms on the response to losartan, demonstrating that AT or TT genotypes of rs4291 were more frequent in the group of controlled AH (54.9%), indicating that these individuals are 2.8 times more likely to of being controlled AH (95% CI 1.12-6.80, p. =0.026) compared to those with AA genotype. In contrast, no influence of ACE polymorphisms on the response to hydrochlorothiazide was observed. In conclusion, the presence of the T allele of the rs4291 variant was associated to controled blood pressure when losartan was used as an antihypertensive agent. These results show the importance of pharmacogenetic studies to detect genetic characteristics, enabling therapeutic individuality and reducing costs for the healthcare system.

Relevance of CYP2D6 Gene Variants in Population Genetic Differentiation

A significant portion of the variability in complex features, such as drug response, is likely caused by human genetic diversity. One of the highly polymorphic pharmacogenes is CYP2D6, encoding an enzyme involved in the metabolism of about 25% of commonly prescribed drugs. In a directed search of the 1000 Genomes Phase III variation data, 86 single nucleotide polymorphisms (SNPs) in the CYP2D6 gene were extracted from the genotypes of 2504 individuals from 26 populations, and then used to reconstruct haplotypes. Analyses were performed using Haploview, Phase, and Arlequin softwares. Haplotype and nucleotide diversity were high in all populations, but highest in populations of African ancestry. Pairwise F_ST showed significant results for eleven SNPs, six of which were characteristic of African populations, while four SNPs were most common in East Asian populations. A principal component analysis of CYP2D6 haplotypes showed that African populations form one cluster, Asian populations form another cluster with East and South Asian populations separated, while European populations form the third cluster. Linkage disequilibrium showed that all African populations have three or more haplotype blocks within the CYP2D6 gene, while other world populations have one, except for Chinese Dai and Punjabi in Pakistan populations, which have two.