Pharmacogenetics and human molecular genetics of opiate and cocaine addictions and their treatments
ABSTRACT Opiate and cocaine addictions are major social and medical problems that impose a significant burden on society. Despite the size and scope of these problems, there are few effective treatments for these addictions. Methadone maintenance is an effective and most widely used treatment for opiate addiction, allowing normalization of many physiological abnormalities caused by chronic use of short-acting opiates. There are no pharmacological treatments for cocaine addiction. Epidemiological, linkage, and association studies have demonstrated a significant contribution of genetic factors to the addictive diseases. This article reviews the molecular genetics and pharmacogenetics of opiate and cocaine addictions, focusing primarily on genes of the opioid and monoaminergic systems that have been associated with or have evidence for linkage to opiate or cocaine addiction. This evidence has been marshalled either through identification of variant alleles that lead to functional alterations of gene products, altered gene expression, or findings of linkage or association studies. Studies of polymorphisms in the mu opioid receptor gene, which encodes the receptor target of some endogenous opioids, heroin, morphine, and synthetic opioids, have contributed substantially to knowledge of genetic influences on opiate and cocaine addiction. Other genes of the endogenous opioid and monoaminergic systems, particularly genes encoding dopamine beta-hydroxylase, and the dopamine, serotonin, and norepinephrine transporters have also been implicated. Variants in genes encoding proteins involved in metabolism or biotransformation of drugs of abuse and also of treatment agents are reviewed.
- SourceAvailable from: Sally K Guthrie
[Show abstract] [Hide abstract]
- "The GG mice have a four-fold greater vStr/NAcc DA release to alcohol than the former (Ramchandani et al., 2011). Also this gene is involved in opiate and cocaine addiction and treatment (Kreek et al., 2005). Recently Zhang et al. (2015) found that GG mice self-administrated more heroin and had more brain dopamine release in response to heroin than AA mice. "
ABSTRACT: To determine if overnight tobacco abstinent carriers of the AG or GG (*G) vs. the AA variant of the human mu opioid receptor (OPRM1) A118G polymorphism (rs1799971) differ in [(11)C]carfentanil binding after tobacco smoking. Twenty healthy American male smokers who abstained from tobacco overnight were genotyped and completed positron emission tomography (PET) scans with the mu opioid receptor agonist, [(11)C]carfentanil. They smoked deniconized (denic) and average nicotine (avnic) cigarettes during the PET scans. Smoking avnic cigarette decreased the binding potential (BPND) of [(11)C]carfentanil in the right medial prefrontal cortex (mPfc; 6,56,18), left anterior medial prefrontal cortex (amPfc; -2,46,44), right ventral striatum (vStr; 16, 3, -10), left insula (Ins; -42,10,-12), right hippocampus (Hippo; 18,-6,-14) and left cerebellum (Cbl; -10,-88,-34), and increased the BPND in left amygdala (Amy; -20,0,-22), left putamen (Put; -22, 10,-6) and left nucleus accumbens (NAcc; -10,12,-8). In the AA allele carriers, avnic cigarette smoking significantly changed the BPND compared to after denic smoking in most brain areas listed above. However in the *G carriers the significant BPND changes were confirmed in only amPfc and vStr. Free mu opioid receptor availability was significantly less in the *G than the AA carriers in the Amy and NAcc. The present study demonstrates BPND changes induced by avnic smoking in OPRM1 *G carriers were blunted compared to the AA carriers. Also *G smokers had less free mu opioid receptor availability in Amy and NAcc. Copyright © 2015. Published by Elsevier Inc.Progress in Neuro-Psychopharmacology and Biological Psychiatry 01/2015; 59. DOI:10.1016/j.pnpbp.2015.01.007 · 4.03 Impact Factor
[Show abstract] [Hide abstract]
- "Overall, cocaine appears to primarily act by inhibiting presynaptic dopamine transporters, but also hinders serotonin and norepinephrine transporters (Sora et al., 2001; Hall et al., 2004; Kreek et al., 2005; Hall et al., 2009), and may also secondarily dysregulate inhibitory GABAergic function (Cameron & Williams, 1994). Cocaine also modulates the endogenous opioid system, especially MOR, κ opioid receptors (KOR), and preprodynorphin (Kreek et al., 2005). "
ABSTRACT: Considerable insight has been gained into the comorbid, interactive effects of HIV and drug abuse in the brain using experimental models. This review, which considers opiates, methamphetamine, and cocaine, emphasizes the importance of host genetics and glial plasticity in driving the pathogenic neuron remodeling underlying neuro-acquired immunodeficiency syndrome and drug abuse comorbidity. Clinical findings are less concordant than experimental work, and the response of individuals to HIV and to drug abuse can vary tremendously. Host-genetic variability is important in determining viral tropism, neuropathogenesis, drug responses, and addictive behavior. However, genetic differences alone cannot account for individual variability in the brain "connectome." Environment and experience are critical determinants in the evolution of synaptic circuitry throughout life. Neurons and glia both exercise control over determinants of synaptic plasticity that are disrupted by HIV and drug abuse. Perivascular macrophages, microglia, and to a lesser extent astroglia can harbor the infection. Uninfected bystanders, especially astroglia, propagate and amplify inflammatory signals. Drug abuse by itself derails neuronal and glial function, and the outcome of chronic exposure is maladaptive plasticity. The negative consequences of coexposure to HIV and drug abuse are determined by numerous factors including genetics, sex, age, and multidrug exposure. Glia and some neurons are generated throughout life, and their progenitors appear to be targets of HIV and opiates/psychostimulants. The chronic nature of HIV and drug abuse appears to result in sustained alterations in the maturation and fate of neural progenitors, which may affect the balance of glial populations within multiple brain regions.International Review of Neurobiology 01/2014; 118C:231-313. DOI:10.1016/B978-0-12-801284-0.00009-9 · 2.46 Impact Factor
[Show abstract] [Hide abstract]
- "Subsequent studies have both found (Szeto et al., 2001; Tan et al., 2003; Bart et al., 2004) and failed to find (Li et al., 2000; Franke et al., 2001; Shi et al., 2002; Crowley et al., 2003; Tan et al., 2003) significant associations for the same polymorphism. Population admixture has been suggested to be involved in positive associations with this polymorphism when they have been observed in some, though not all, cases (Kreek et al., 2005). "
ABSTRACT: Substantial genetic contributions to addiction vulnerability are supported by data from twin studies, linkage studies, candidate gene association studies and, more recently, Genome Wide Association Studies (GWAS). Parallel to this work, animal studies have attempted to identify the genes that may contribute to responses to addictive drugs and addiction liability, initially focusing upon genes for the targets of the major drugs of abuse. These studies identified genes/proteins that affect responses to drugs of abuse; however, this does not necessarily mean that variation in these genes contributes to the genetic component of addiction liability. One of the major problems with initial linkage and candidate gene studies was an a priori focus on the genes thought to be involved in addiction based upon the known contributions of those proteins to drug actions, making the identification of novel genes unlikely. The GWAS approach is systematic and agnostic to such a priori assumptions. From the numerous GWAS now completed several conclusions may be drawn: (1) addiction is highly polygenic; each allelic variant contributing in a small, additive fashion to addiction vulnerability; (2) unexpected, compared to our a priori assumptions, classes of genes are most important in explaining addiction vulnerability; (3) although substantial genetic heterogeneity exists, there is substantial convergence of GWAS signals on particular genes. This review traces the history of this research; from initial transgenic mouse models based upon candidate gene and linkage studies, through the progression of GWAS for addiction and nicotine cessation, to the current human and transgenic mouse studies post-GWAS.Pharmacology [?] Therapeutics 07/2013; DOI:10.1016/j.pharmthera.2013.07.006 · 7.75 Impact Factor