Subcortical dopamine D2 receptor (DRD2) signaling is implicated in cognitive processes and brain disorders, but the effect ofDRD2variants remains ambiguous. We measured allelic mRNA expression in postmortem human striatum and prefrontal cortex and then performed single nucleotide polymorphism (SNP) scans of theDRD2locus. A previously uncharacterized promoter SNP (rs12364283) located in a conserved suppressor region was associated with enhanced DRD2 expression, whereas previously studiedDRD2variants failed to affect expression. Moreover, two frequent intronic SNPs (rs2283265 and rs1076560) decreased expression of DRD2 short splice variant (expressed mainly presynaptically) relative to DRD2 long (postsynaptic), a finding reproducedin vitroby using minigene constructs. Being in strong linkage disequilibrium with each other, both intronic SNPs (but not rs12364283) were also associated with greater activity of striatum and prefrontal cortex measured with fMRI during working memory and with reduced performance in working memory and attentional control tasks in healthy humans. Our results identify regulatoryDRD2polymorphisms that modify mRNA expression and splicing and working memory pathways.

Personalized medicine tailors therapies, disease prevention, and health maintenance to the individual, with pharmacogenomics serving as a key tool to improve outcomes and prevent adverse effects. Advances in genomics have transformed pharmacogenetics, traditionally focused on single gene-drug pairs, into pharmacogenomics, encompassing all 9omics9 fields, e.g., proteomics, transcriptomics, metabolomics, and metagenomics. This review summarizes basic genomics principles relevant to translation into therapies, assessing pharmacogenomics9 central role in converging diverse elements of personalized medicine. We discuss genetic variations in pharmacogenes (drug-metabolizing enzymes, drug transporters, and receptors), their clinical relevance as biomarkers, and the legacy of decades of research in pharmacogenetics. All types of therapies, including proteins, nucleic acids, viruses, cells, genes, and irradiation, can benefit from genomics, expanding the role of pharmacogenomics across medicine. FDA approvals of personalized therapeutics involving biomarkers increase rapidly, demonstrating the growing impact of pharmacogenomics. A beacon for all therapeutic approaches, molecularly targeted cancer therapies highlight trends in drug discovery and clinical applications. To account for human complexity, multi-component biomarker panels encompassing genetic, personal, and environmental factors can guide diagnosis and therapies, increasingly involving artificial intelligence to cope with extreme data complexities. However, clinical application encounters substantial hurdles, such as unknown validity across ethnic groups, underlying bias in health care, and real-world validation. This review will address the underlying science and technologies germane to pharmacogenomics and personalized medicine, integrated with economic, ethical, and regulatory issues - providing insights into the current status and future direction of health care. Significance Statement Personalized medicine aims to optimize health care for the individual patients with use of predictive biomarkers to improve outcomes and prevent adverse effects. Pharmacogenomics drives biomarker discovery and guides the development of targeted therapeutics. This review addresses basic principles and current trends in pharmacogenomics, with large-scale data repositories accelerating medical advances. The impact of pharmacogenomics is discussed, along with hurdles impeding broad clinical implementation, in the context of clinical care, ethics, economics, and regulatory affairs.

Opioid receptors display basal signaling (constitutive, agonist-independent activity), which seems to be regulated by agonist exposure. Whereas agonist pretreatment desensitizes receptors to subsequent agonist stimulation, basal signaling of μ-opioid receptor (MOR) was shown to increase. Moreover, agonist pretreatment converts the neutral antagonists naloxone and naltrexone into inverse agonists, suppressing basal signaling, whereas analogs with reduced C6-position, e.g., 6β-naltrexol, remain neutral antagonists at MOR under any condition. This study compares the regulation of basal signaling of MOR, δ-(DOR), and κ-(KOR) opioid receptors after pretreatment with morphine or receptor-selective agonists, in transfected human embryonic kidney 293 cell membranes. Moreover, naloxone, naltrexone, and related antagonists were compared for binding potency and effect on basal and agonist-stimulated receptor signaling, measuring guanosine 5′-O-(3-[³⁵S]thio)triphosphate binding. The results demonstrate basal activity for each opioid receptor, which is modulated by pretreatment with agonists. Even closely related opioid antagonists display distinct patterns of neutral and inverse effects before and after agonist pretreatment, including distinct efficacies between naloxone and naltrexone at agonist-pretreated DOR and KOR. Pretreatment with different agonists has varying effects on inverse and neutral activities of some analogs tested. These results demonstrate that antagonist efficacy is context-dependent, possibly accounting for paradoxical pharmacological effects. Activity profiles at the three opioid receptors under different conditions could lead to antagonists with optimal clinical properties in treatment of addiction and adverse opioid effects.

Objectives The voltage-dependent L-type calcium channel α-subunit 1c (Cav1.2, CACNA1C) undergoes extensive mRNA splicing, leading to numerous isoforms with different functions. L-type calcium channel blockers are used in the treatment of hypertension and arrhythmias, but response varies between individuals. We have studied the interindividual variability in mRNA expression and splicing of CACNA1C, in 65 heart tissue samples, taken from heart transplant recipients. Methods Splice variants were measured quantitatively by polymerase chain reaction in 12 splicing loci of CACNA1C mRNA. To search for functional cis-acting polymorphisms, we determined allelic expression ratios for total CACNA1C mRNA and several splice variants using marker single nucleotide polymorphisms in exon 4 and exon 30. Results Total CACNA1C mRNA levels varied ∼50-fold. Substantial splicing occurred in six loci generating two or more splice variants, some with known functional differences. Splice patterns varied broadly between individuals. Two heart tissues expressed predominantly the dihydropyridine-sensitive smooth muscle isoform of CACNA1C (containing exon 8), rather than the cardiac isoform (containing exon 8a). Lack of significant allelic expression imbalance, observed with total mRNA and several splice variants, argued against CACNA1C polymorphisms as a cause of variability. Taken together, highly variable splicing can cause profound phenotypic variations of CACNA1C function, potentially associated with disease susceptibility and response to L-type calcium channel blockers.

Human alveolar macrophages (HAM) are primary bacterial niche and immune response cells during Mycobacterium tuberculosis (M.tb) infection, and human blood monocyte-derived macrophages (MDM) are a model for investigating M.tb-macrophage interactions. Here, we use a targeted RNA-Seq method to measure transcriptome-wide changes in RNA expression patterns of freshly obtained HAM (used within 6 h) and 6 day cultured MDM upon M.tb infection over time (2, 24 and 72 h), in both uninfected and infected cells from three donors each. The Ion AmpliSeq™ Transcriptome Human Gene Expression Kit (AmpliSeq) uses primers targeting 18,574 mRNAs and 2,228 non-coding RNAs (ncRNAs) for a total of 20,802 transcripts. AmpliSeq^TM yields highly precise and reproducible gene expression profiles (R² >0.99). Taking advantage of AmpliSeq’s reproducibility, we establish well-defined quantitative RNA expression patterns of HAM versus MDM, including significant M.tb-inducible genes, in networks and pathways that differ in part between MDM and HAM. A similar number of expressed genes are detected at all time-points between uninfected MDM and HAM, in common pathways including inflammatory and immune functions, but canonical pathway differences also exist. In particular, at 2 h, multiple genes relevant to the immune response are preferentially expressed in either uninfected HAM or MDM, while the HAM RNA profiles approximate MDM profiles over time in culture, highlighting the unique RNA expression profile of freshly obtained HAM. MDM demonstrate a greater transcriptional response than HAM upon M.tb infection, with 2 to >10 times more genes up- or down-regulated. The results identify key genes involved in cellular responses to M.tb in two different human macrophage types. Follow-up bioinformatics analysis indicates that approximately 30% of response genes have expression quantitative trait loci (eQTLs in GTEx), common DNA variants that can influence host gene expression susceptibility or resistance to M.tb, illustrated with the TREM1 gene cluster and IL-10.