Genome-wide analysis of hepatic DNA methylation reveals impact of epigenetic aging on xenobiotic metabolism and transport genes in an aged mouse model.

Hepatic xenobiotic metabolism and transport decline with age, while intact xenobiotic metabolism is associated with longevity. However, few studies have examined the genome-wide impact of epigenetic aging on these processes. We used reduced representation bisulfite sequencing (RRBS) to map DNA methylation changes in liver DNA from mice ages 4 and 24 months. We identified several thousand age-associated differentially methylated sites (a-DMS), many of which overlapped genes encoding Phase I and Phase II drug metabolizing enzymes, in addition to ABC and SLC classes of transporters. Notable genes harboring a-DMS were Cyp1a2, Cyp2d9, and Abcc2 that encode orthologs of the human drug metabolizing enzymes CYP1A2 and CYP2D6, and the multidrug resistance protein 2 (MRP2) transporter. Cyp2d9 hypermethylation with age was significantly associated with reduced gene expression, while Abcc2 expression was unchanged with age. Cyp1a2 lost methylation with age while, counterintuitively, its expression also reduced with age. We hypothesized that age-related dysregulation of the hepatic transcriptional machinery caused down-regulation of genes despite age-related hypomethylation. Bioinformatic analysis of hypomethylated a-DMS in our sample found them to be highly enriched for hepatic nuclear factor 4 alpha (HNF4α) binding sites. HNF4α promotes Cyp1a2 expression and is downregulated with age, which could explain the reduction in Cyp1a2 expression. Overall, our study supports the broad impact of epigenetic aging on xenobiotic metabolism and transport. Future work should evaluate the interplay between hepatic nuclear receptor function and epigenetic aging. These results may have implications for studies of longevity and healthy aging.

The frequency of major ABCG2, SLCO1B1 and CYP2C9 variants in Asian, Native Hawaiian and Pacific Islander women subgroups: implications for personalized statins dosing.

Aim: The frequencies of SLCO1B1*5 and CYP2C9*2 and *3 in specific Asian, Native Hawaiian and Pacific Islander (NHPI) subgroups are unknown. Patients & methods: Repository DNA samples from 1064 women self-identifying as Filipino, Korean, Japanese, Native Hawaiian, Marshallese or Samoan and aged 18 years or older were used for targeted sequencing of three genetic variants (rs4149056, rs1799853 and rs1057910). Results: SLCO1B1*5 was significantly less frequent in NHPI women (0.5-6%) than in Europeans (16%). Except for Koreans, CYP2C9*2 (0-1.4%) and *3 (0.5-3%) were significantly less frequent in all subgroups than in Europeans (8 and 12.7%, respectively). Prior reports showed that Asian and NHPI individuals have significantly higher ABCG2 Q141K allele frequency (13-46%) than Europeans (9.4%). Combined phenotype rates for rosuvastatin and fluvastatin revealed that Filipinos and Koreans had the highest frequencies of statin-associated myopathy symptoms risk alleles. Conclusion: Differences in ABCG2, SLCO1B1 and CYP2C9 allele frequencies among different racial and ethnic subgroups highlight the need for increased diversity in pharmacogenetic research. Risk alleles for statin-associated myopathy symptoms are more prevalent in Filipinos, underscoring the importance of genotype-based statin dosing.

Statins are medications used to lower low-density lipoprotein ('bad') cholesterol. Variation in genes for proteins which transport drugs (SLCO1B1 and ABCG2) or metabolize drugs (CYP2C9) may significantly influence how much statin someone is exposed to. Genetic variants within SLCO1B1 can affect exposure to all statins, while variants within ABCG2 and CYP2C9 can affect exposure to rosuvastatin and fluvastatin, respectively. The prevalence of the decreased or no-function genetic variants is unknown among Filipino and Native Hawaiian and Pacific Islander (NHPI) subgroups. The major racial categorization of 'Asians and NHPI' (ANHPI) can miss potential genetic and ancestral differences among population subgroups. Our study used biobank data from 1064 women of ANHPI descent to estimate the frequencies of four important variants within SLCO1B1, ABCG2 and CYP2C9. Those of ANHPI ancestry were less likely to have variations in SLCO1B1 and CYP2C9 but significantly more likely to have nonfunctional ABCG2 than Europeans. Our findings provide insight into SLCO1B1 and CYP2C9 genetic variations among under-represented subgroups. Specifically, Filipinos and Koreans have the highest rates of higher risk genetic variants linked to high rosuvastatin and fluvastatin exposure and muscle-related side effects. Estimating the frequency of genetic variations in under-represented subgroups is pivotal in reducing health disparities in treatment outcomes, diversifying pharmacogenetic research and advancing personalized medicine.

The frequency of rs2231142 in ABCG2 among Native Hawaiian and Pacific Islander subgroups: implications for personalized rosuvastatin dosing.

Statins are among the most commonly prescribed medications worldwide. Rosuvastatin is a moderate- to high-intensity statin depending on the prescribed dose. Statin-associated muscle symptoms are the main side effects, contributing to low adherence to statins. The missense variant rs2231142 in ABCG2 affects the functionality of the ABCG2 transporter, altering the pharmacokinetics and pharmacodynamics of rosuvastatin. This special report aims to accentuate the importance of considering the ABCG2 genotype upon prescribing rosuvastatin in high cardiovascular disease risk subgroups, specifically Native Hawaiian and Pacific Islander populations. Based on the reported frequencies of rs2231142 in ABCG2, it may be justifiable to initiate low-dose rosuvastatin in Samoans relative to Marshallese or Native Hawaiians. Interpopulation differences in pharmacogenetic allele frequencies underscore the need to disaggregate broad population categories to achieve health equity in treatment outcomes.

Rosuvastatin is a medication that is used to decrease levels of bad cholesterol in the blood. One of the side effects of rosuvastatin is muscle aches, which can cause patients to stop taking their medication. ABCG2 is a gene responsible for encoding ABCG2, an important transporter that plays a role in how the body interacts with many medications, including rosuvastatin. Genetic variations in ABCG2 result in a functional or nonfunctional transporter. This special report aims to focus on the importance of considering genetic variations in ABCG2 among different population subgroups, in particular Native Hawaiians, Samoans and Marshallese. The ABCG2 genotype could inform clinicians about the most effective rosuvastatin dose to prescribe. This approach highlights the importance of individualized patient characteristics above and beyond race and ethnicity.

Effects of antirheumatic drug underutilization on rheumatoid arthritis disease activity.

BACKGROUND: Following the recommended guidelines is crucial for achieving patient remission in rheumatoid arthritis. The aim of this study was to assess the effect of proper drug utilization of antirheumatic drugs on disease activity and drug safety in Jordan. METHODS: In a retrospective cross-sectional study, patient's demographics, clinical variables, drug regimens and side effects were recorded and the 28-joint disease activity scores were calculated. Patients were stratified into high, moderate, low disease activity or remission group. RESULTS: Around 80% of patients were using methotrexate which was under-dosed in 82% of them. Only 25% were using biologic drugs. Surprisingly, only 10% of patients had low disease activity and only 4% were in a remission state. Anaemia (32.3%) and mild renal impairment (27.6%) were the most common side effects. CONCLUSIONS: The low frequency of well-controlled disease activity is interpreted by high occurrence of methotrexate underdosing and biologic agent underprescription. Implementing the role of a clinical pharmacist could have a real impact on tight control of such disease issues in Jordan.