Heroin use promotes HCV infection and dysregulates HCV-related circulating microRNAs

Direct effects of heroin and methadone on T cell function

Opioid addiction presents a relevant health challenge, with chronic heroin use linked to detrimental effects on various aspects of physical, mental, and sociological health. Opioid maintenance therapy (OMT), particularly using methadone, is the primary treatment option for heroin addiction. Previous studies using blood samples from current heroin addicts and OMT patients have shown immunomodulatory effects of heroin and methadone on T cell function. However, various additional factors beyond heroin and methadone affect these results, including the consumption of other substances, a stressful lifestyle, comorbid psychological and somatic disorders, as well as additional medications. Therefore, we here investigated the direct effects of heroin and methadone on purified human T cells in vitro. Our results reveal that both, heroin and methadone directly suppress Tcell activation and proliferation. Strikingly, this inhibitory effect was markedly stronger in the presence of methadone, correlating with a decrease in secretion of pro-inflammatory cytokines. While heroin did not interfere with the in vitro differentiation and expansion of regulatory Tcells (Tregs), methadone significantly impaired the proliferation of Tregs. Overall, our findings suggest a direct inhibitory impact of both opioids on effector T cell function in vitro, with methadone additionally interfering with Treg induction and expansion in contrast to heroin.

The Impact of Drugs and Substance Abuse on Viral Pathogenesis-A South African Perspective

Illicit drug and alcohol abuse have significant negative consequences for individuals who inject drugs/use drugs (PWID/UDs), including decreased immune system function and increased viral pathogenesis. PWID/UDs are at high risk of contracting or transmitting viral illnesses such as human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV). In South Africa, a dangerous drug-taking method known as "Bluetoothing" has emerged among nyaope users, whereby the users of this drug, after injecting, withdraw blood from their veins and then reinject it into another user. Hence, the transmission of blood-borne viruses (BBVs) is exacerbated by this "Bluetooth" practice among nyaope users. Moreover, several substances of abuse promote HIV, HBV, and HCV replication. With a specific focus on the nyaope drug, viral replication, and transmission, we address the important influence of abused addictive substances and polysubstance use in this review.

The role of miRNAs in liver diseases: Potential therapeutic and clinical applications

MicroRNAs (miRNAs) are a class of short, non-coding RNAs that function post-transcriptionally to regulate gene expression by binding to particular mRNA targets and causing destruction of the mRNA or translational inhibition of the mRNA. The miRNAs control the range of liver activities, from the healthy to the unhealthy. Considering that miRNA dysregulation is linked to liver damage, fibrosis, and tumorigenesis, miRNAs are a promising therapeutic strategy for the evaluation and treatment of liver illnesses. Recent findings on the regulation and function of miRNAs in liver diseases are discussed, with an emphasis on miRNAs that are highly expressed or enriched in hepatocytes. Alcohol-related liver illness, acute liver toxicity, viral hepatitis, hepatocellular carcinoma, liver fibrosis, liver cirrhosis, and exosomes in chronic liver disease all emphasize the roles and target genes of these miRNAs. We briefly discuss the function of miRNAs in the etiology of liver diseases, namely in the transfer of information between hepatocytes and other cell types via extracellular vesicles. Here we offer some background on the use of miRNAs as biomarkers for the early prognosis, diagnosis, and assessment of liver diseases. The identification of biomarkers and therapeutic targets for liver disorders will be made possible by future research into miRNAs in the liver, which will also help us better understand the pathogeneses of liver diseases.

MicroRNAs in Various Body Fluids and its importance in Forensic Medicine

MicroRNAs (miRNAs) are a class of noncoding RNAs which regulate gene expression. miRNAs have tissue-specific expression and are also present in various extracellular body fluids, including blood, tears, semen, vaginal fluid and urine. Additionally, expression of miRNAs in body fluids is linked to various pathological diseases, including cancer and neurodegenerative diseases. Examination of body fluids is important in forensic medicine as they serve as a valuable form of evidence. Due to its stability, miRNA offers an advantage for body fluid identification, which can be detected even after several months or from compromised samples. Identification of unique miRNA profiles for different body fluids enable the identification of these body fluid. Furthermore, miRNAs profiling can be used to estimate post-mortem interval. Various biochemical and molecular methods have been used for identification of miRNAs have shown promising results. We discuss different miRNAs as specific biomarkers and their clinical importance regarding different pathological conditions, as well as their medico-legal importance.

Whole Transcriptome Sequencing of Peripheral Blood Shows That Immunity/GnRH/PI3K-Akt Pathways Are Associated With Opioid Use Disorder

BACKGROUND

Opioid use disorder (OUD), which is most commonly exhibited as addiction, is a persistent chronic disease that places a burden on families and society. Various peripheral traits have been linked to OUD in the past, but research on this topic is insufficient.

METHODS

Seven male patients with OUD and 7 male healthy controls with matched demographic and clinical data were enrolled in this study. Peripheral blood RNA was used to construct an rRNA-removed library and a small RNA library. The peripheral transcriptomic differences between the two groups were investigated using RNA-seq. Differentially expressed messenger RNAs (mRNAs), long non-coding RNAs (lncRNAs), circular RNAs (circRNAs) and microRNAs (miRNAs) were identified by bioinformatics methods, and functional enrichment analysis with differentially expressed RNAs was performed to investigate the potential biological mechanisms of OUD.

RESULTS

A total of 229 mRNAs (115 upregulated, 114 downregulated), 416 lncRNAs (191 upregulated, 225 downregulated), 17 circRNAs (16 upregulated, 1 downregulated) and 74 miRNAs (42 upregulated, 32 downregulated) were differentially expressed between the OUD group and the healthy control group. Functional enrichment analysis with differentially expressed mRNAs showed that immunity, GnRH secretion, and PI3K-Akt signaling pathways were associated with OUD. Immunity-, JAK-STAT-, and insulin-related pathways were enriched in functional enrichment analysis of target genes predicted by differentially expressed miRNAs.

CONCLUSION

We identified hundreds of differentially expressed genes that were enriched in immunity, GnRH secretion and PI3K-Akt signaling pathways. Some genes with significant changes might be used as potential biomarkers for progression and treatment of OUD.

Drugs of Abuse and Their Impact on Viral Pathogenesis

Commonly misused substances such as alcohol, cocaine, heroin, methamphetamine, and opioids suppress immune responses and may impact viral pathogenesis. In recent years, illicit use of opioids has fueled outbreaks of several viral pathogens, including the human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV). This review focuses on the myriad of mechanisms by which drugs of abuse impact viral replication and disease progression. Virus–drug interactions can accelerate viral disease progression and lead to increased risk of virus transmission.

Psychoactive Substances Taken with Mephedrone and HCV Infection

Background: In recent years, the observed frequency of hospitalization of patients taking mephedrone with other psychoactive substances has increased. There are no data in the literature on the effect of mephedrone use on liver function in patients, including the frequency of HCV infection. We have analysed the impact of taking mephedrone together with other psychoactive substances on the incidence of HCV infection. We have also analysed the effect of taking mephedrone with heroin, alcohol, and benzodiazepines on liver enzyme levels. Methods: The study included patients taking mephedrone with: alcohol (n = 115), heroin (n = 85) and benzodiazepines (n = 130) hospitalized in 2010–2018. The control group consisted of patients addicted to alcohol (n = 180), heroin (n = 221) and benzodiazepines (n = 152). Clinical data and laboratory findings were collected from medical records. Results: Taking mephedrone together with benzodiazepines is a statistically significant predictor of HCV infection in this group of patients, OR (8.44); 95% CI 5.63–12.64; p < 0.001). A statistically significant interaction of the group with HCV infection was observed, i.e., for the level of alanine transaminase (p < 0.001) and aspartate transaminase (p < 0.001). Increased levels of liver enzymes in each of the studied groups was characteristic in patients with HCV infection (p < 0.001). Taking additional mephedrone by this group of patients did not increase the level of liver enzymes. Conclusion: HCV infection is a statistically significant factor affecting the increase in liver enzymes levels in the group of patients taking mephedrone.

Heroin-assisted treatment of heroin-addicted patients normalizes regulatory T cells but does not restore CD4+ T cell proliferation

Heroin dependence may result in suppression of adaptive immune responses. Previously, we demonstrated an increase in relative numbers of inhibitory CD4⁺ regulatory T cells (Tregs) and impaired proliferative activity of CD4⁺ T cells from heroin-addicted patients in contrast to patients in opioid maintenance therapy and healthy controls. However, it remains elusive whether heroin has a direct impact on the CD4⁺ T cell compartment or whether observed effects result from stressful living conditions. Here, we analyzed the frequencies of Tregs and the proliferation as well as the cytokine production of stimulated CD4⁺ T cells from heroin-addicted patients with use of illicit heroin, patients in heroin-assisted treatment (HAT), and patients in methadone maintenance therapy (MMT). Relative numbers of CD4⁺ Tregs were significantly enhanced in patients with illicit heroin abuse compared with patients in HAT or MMT. Notably, CD4⁺ T cells from patients in HAT and from persons using illicit heroin showed significant reduced proliferation and secretion of the pro-inflammatory cytokines IFN-γ and IL-6 upon stimulation in vitro. From these results, we conclude that structured programs such as HAT and MMT dampen elevated frequencies of Tregs in heroin-addicted patients, whereas chronic heroin administration irrespective of using illicit heroin or receiving HAT has a direct impact on the proliferative activity and cytokine production of CD4⁺ T cells.

The synthetic opioid fentanyl enhances viral replication in vitro

The US is in the midst of a major drug epidemic fueled in large part by the widespread recreational use of synthetic opioids such as fentanyl. Persons with opioid use disorder are at significant risk for transmission of injection-associated infections such as hepatitis B virus (HBV) and hepatitis C virus (HCV). Commonly abused substances may antagonize immune responses and promote viral replication. However, the impact of synthetic opioids on virus replication has not been well explored. Thus, we evaluated the impact of fentanyl and carfentanil using in vitro systems that replicate infectious viruses. Fentanyl was used in cell lines replicating HBV or HCV at concentrations of 1 ng, 100 ng, and 10 ug. Viral protein synthesis was quantified by ELISA, while apoptosis and cell death were measured by M30 or MTT assays, respectively. HCV replicative fitness was evaluated in a luciferase-based system. RNAseq was performed to evaluate cellular gene regulation in the presence of fentanyl. Low dose fentanyl had no impact on HCV replication in Huh7.5JFH1 hepatocytes; however, higher doses significantly enhanced HCV replication. Similarly, a dose-dependent increase in HCV replicative fitness was observed in the presence of fentanyl. In the HepG2.2.15 hepatocyte cell line, fentanyl caused a dose-dependent increase in HBV replication, although only a higher doses than for HCV. Addition of fentanyl resulted in significant apoptosis in both hepatocyte cell lines. Cell death was minimal at low drug concentrations. RNAseq identified a number of hepatocyte genes that were differentially regulated by fentanyl, including those related to apoptosis, the antiviral / interferon response, chemokine signaling, and NFκB signaling. Collectively, these data suggest that synthetic opioids promote viral replication but may have distinct effects depending on the drug dose and the viral target. As higher viral loads are associated with pathogenesis and virus transmission, additional research is essential to an enhanced understanding of opioid-virus pathogenesis and for the development of new and optimized treatment strategies.

Increased Expression of Plasma miRNA-320a and let-7b-5p in Heroin-Dependent Patients and Its Clinical Significance

Heroin use disorder is a chronic and relapsing disease that induces persistent changes in the brain. The diagnoses of heroin use disorders are mainly based on subjective reports and no valid biomarkers available. Recent researches have revealed that circulating miRNAs are useful non-invasive biomarkers for diagnosing brain diseases such as Alzheimer's disease, multiple sclerosis, schizophrenia, and bipolar disorder. However, studies on circulating miRNAs for the diagnosis of heroin use disorders are rarely reported. In this study, we investigated the differential expression of plasma miRNAs in 57 heroin-dependent patients. Based on literature research and microarray analysis, two candidate miRNAs, miR-320a and let-7b-5p, were selected and analyzed by quantitative real-time RT-PCR. The results showed miR-320a and let-7b were significantly upregulated in plasma of the heroin-dependent patients compared to that in healthy controls. The area under curves (AUCs) of receiver operating characteristic (ROC) curves of miR-320a and let-7b-5p were 0.748 and 0.758, respectively. The sensitivities of miR-320a and let-7b-5p were 71.9 and 70.2%, while the specificities of miR-320a and let-7b-5p were 76.1 and 78.3%, respectively. The combination of these two miRNAs predicted heron dependence with an AUC of 0.782 (95% CI 0.687-0.876), with 73.7% sensitivity and 82.6% specificity. Our findings suggest a potential use for circulating miRNAs as biomarkers for the diagnosis of heroin abuse.

miRNAs as Potential Biomarkers for Viral Hepatitis B and C

Around 257 million people are living with hepatitis B virus (HBV) chronic infection and 71 million with hepatitis C virus (HCV) chronic infection. Both HBV and HCV infections can lead to liver complications such as cirrhosis and hepatocellular carcinoma (HCC). To take care of these chronically infected patients, one strategy is to diagnose the early stage of fibrosis in order to treat them as soon as possible to decrease the risk of HCC development. microRNAs (or miRNAs) are small non-coding RNAs which regulate many cellular processes in metazoans. Their expressions were frequently modulated by up- or down-regulation during fibrosis progression. In the serum of patients with HBV chronic infection (CHB), miR-122 and miR-185 expressions are increased, while miR-29, -143, -21 and miR-223 expressions are decreased during fibrosis progression. In the serum of patients with HCV chronic infection (CHC), miR-143 and miR-223 expressions are increased, while miR-122 expression is decreased during fibrosis progression. This review aims to summarize current knowledge of principal miRNAs modulation involved in fibrosis progression during chronic hepatitis B/C infections. Furthermore, we also discuss the potential use of miRNAs as non-invasive biomarkers to diagnose fibrosis with the intention of prioritizing patients with advanced fibrosis for treatment and surveillance.

Synthetic Opioid Use and Common Injection-associated Viruses: Expanding the Translational Research Agenda

The US is in the midst of a major epidemic of opioid addiction and related comorbidities. People with opioid use disorder (OUD) are at significant risk for transmission of several blood-borne pathogens including the human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV). Commonly abused opioids and their receptors promote viral replication and virus-mediated pathology. However, most studies demonstrating an adverse effect of drugs of abuse have been conducted in vitro, the specific effects of synthetic opioids on viral replication have been poorly characterized, and the evaluation of opioid-virus interactions in clinically relevant populations is rare. Rigorous characterization of the interactions among synthetic opioids, host cells, and common injection-associated viral infections will require an interdisciplinary research approach and translational studies conducted on humans. Such research promises to improve clinical management paradigms for difficult-to-treat populations, facilitate rational public health policies given severely strained resources, and reveal additional pathways for novel target-specific therapeutic interventions. This mini-review examines the published literature on the effects of opioids on HIV, HBV, and HCV pathogenesis and proposes a series of scientific questions and considerations to establish a translational research agenda focused on opioid-virus interactions.

Altered serum microRNA expression profile in subjects with heroin and methamphetamine use disorder

OBJECTIVES

Drug abuse is one of the most severe global social and public health problems, especially in China. However, objective blood biomarkers that are easy to detect are still in great need. This study was aim to explore the expression pattern of circulating microRNAs (miRNAs) in subjects with drug addiction and test the potential of altered serum miRNAs as noninvasive diagnostic tools for drug abuse.

METHODS

Serum samples were obtained from 42 heroin abusers, 42 methamphetamine (MA) abusers and 42 controls. Microarray-based miRNA analysis was first applied to screen unique serum miRNA profiles in drug abusers on a training set of serum samples from 12 heroin abusers, 12 MA abusers and 12 control subjects. The expression levels of selected candidate miRNAs were subsequently verified in individual samples of the training set and further confirmed independently in a validation set of samples from 30 heroin abusers, 30 MA abusers and 30 controls using real-time quantitative polymerase chain reaction (RT-qPCR).

RESULTS

Microarray analysis identified 116 and 109 significantly altered miRNAs in heroin abusers and MA abusers, respectively. Three miRNAs, including let-7b-5p, miR-206 and miR-486-5p, were verified to be significantly and steadily increased in heroin abusers, and miR-9-3p was significantly increased in MA abusers compared with normal controls. The areas under the curve (AUCs) of the ROC curve of these miRNAs ranged from 0.718 to 0.867.

CONCLUSIONS

Our study raises the possibility that the altered serum miRNAs could potentially be used as an auxiliary tool to identify individuals in drug abuse and addiction.

Heroin Abuse and/or HIV Infection Dysregulate Plasma Exosomal miRNAs

Exosomes play an important role in cell-to-cell communication as they can transfer functional molecules such as microRNAs (miRNAs) from one cell to another, exerting biological and immunological functions. Here, we investigated the impact of HIV infection and/or heroin use on the expression of the miRNAs in plasma exosomes. We found that HIV infection or heroin use upregulated the majority (98%) of a panel of plasma exosomal miRNAs associated with immune regulation and inflammation. We also observed the enhanced effect of HIV infection and heroin use on some of these upregulated miRNAs. Our further investigation showed that the levels of four of neuro-inflammation-related miRNAs (146a, 126, 21, and let-7a) were higher in HIV-infected heroin users as compared with the control subjects. These findings indicate that the dysregulations of the plasma exosomal miRNAs support further studies to determine the role of the miRNAs in HIV and/or heroin use-mediated immune modulation and neuro-inflammation. Graphical abstract.

Decreased Level of Blood MicroRNA-133b in Men with Opioid Use Disorder on Methadone Maintenance Therapy

Although previous animal studies have indicated that certain micro ribonucleic acids (microRNAs) play a part in the pathway of opioid addiction, whether such findings extend to human models is yet unknown. This study aims to investigate the important microRNA expressions in patients with opioid use disorder (OUD) on methadone maintenance treatment (MMT) compared to healthy controls and analyze the correlation between microRNAs and opioid characteristics among the patients. We recruited 50 patients and 25 controls, and both groups were matched regarding gender, age, and body mass index. Serum microRNAs (miR-133b, miR-23b, miR-190, miR-206, miR-210, and miR-21) were measured. The age of OUD onset, duration of MMT participation, and recent daily methadone dosage were considered the opioid characteristics. We adopted the t-test to compare the difference between patients and controls and Pearson's correlation to evaluate the association between microRNAs and opioid profiles. Only the level of miR-133b in OUD patients on MMT was significantly lower than that in healthy controls. We did not detect differences of any other microRNA expressions between the two groups. Furthermore, we found no evidence to support the association between microRNAs and opioid characteristics. This study indicates that miR-133b values may be decreased in OUD patients on MMT.

Differential microRNA expression profile in the plasma of preeclampsia and normal pregnancies

Preeclampsia is a common disease in pregnant women that can only be diagnosed from 20 weeks after fertilization. Developing early diagnosis markers is urgent and would be helpful in selecting appropriate treatment strategies. The present study aimed to identify the differential expression profiles of microRNAs in the plasma between patients with preeclampsia and normal pregnancies using microarray methods. Using quantitative polymerase chain reaction (qPCR), the differentially expressed microRNAs (miRNAs or miRs) identified from the microarray analysis were validated. A total of 3 miRNAs, including hsa-miR-1304-5p, hsa-miR-320a and hsa-miR-5002-5p, were upregulated in the plasma of patients with preeclampsia pregnancies. Examination of the functions of these miRNAs demonstrated that they were involved in cell proliferation, indicating that preeclampsia affected this pathway. In addition, 26 downregulated miRNAs were identified by microarray methods. The functions of these miRNAs included immune regulation, vascular development, cancer pathology and pathology of other disease (tuberculosis, oligozoospermia, psoriasis and Alzheimer's disease). Using qPCR, the most differentially expressed miRNAs were confirmed to be hsa-miR-1304-5p, hsa-miR-320a and hsa-miR-5002-5p, which were upregulated, as well as hsa-miR-188-3p, hsa-miR-211-5p, hiv1-miR-TAR-3p, hsa-miR-4432 and hsa-miR-4498 that were significantly downregulated in the plasma of preeclampsia patients. The present findings may be useful in the development of early diagnosis markers and treatment targets for preeclampsia.

Plasma microRNA: A novel non-invasive biomarker for HBV-associated liver fibrosis staging

The aim of the present study was to evaluate the potential use of 7 plasma miRNAs for liver fibrosis staging in patients with chronic hepatitis B virus (HBV) infection. Relative levels of miRNAs were measured using quantitative polymerase chain reaction and used to develop a diagnostic panel. A receiver operating characteristic (ROC) curve was drawn to evaluate the performance of individual miRNAs and the whole panel. It was identified that hsa-miR-122 exhibited significantly different expression levels between F4 and F3, F2, F1, and F0 fibrosis stages (P<0.05), and between F2 and F1 stages (P=0.045); hsa-miR-146a-5p, hsa-miR-29c-3p and hsa-miR-223 exhibited significantly different expression levels between F4 and F0 stages. ROC analysis revealed that hsa-miR-122-5p, hsa-miR-223 and hsa-miR-29c-3p identified patients with ≥F2 fibrosis with area under the curve (AUC) =0.745, 0.631 and 0.670, respectively. hsa-miR-122-5p identified patients with ≥F3 disease (AUC=0.783). hsa-miR-122-5p, hsa-miR-223 and hsa-miR-29c-3p identified patients with cirrhosis with AUC=0.776, 0.617 and 0.619, respectively. The miRNA panel exhibited a higher accuracy compared with individual miRNAs in discriminating between ≥F2, ≥F3 and F4 fibrosis stages with AUC=0.904, 0.889 and 0.835, respectively. hsa-miR-122-5p, hsa-miR-146a, hsa-miR-29c and hsa-miR-223 were positively correlated with fibrosis stage. hsa-miR-122-5p and hsa-miR-381-3p were negatively correlated with alanine aminotransferase, aspartate transaminase and HBV viral DNA load. These 7 miRNAs may serve as potential biomarkers of liver fibrosis in patients with HBV-associated fibrosis. The miRNA panel may serve as a novel non-invasive method for liver fibrosis staging.

Hepatitis C: clinical and biological features related to different forms of cocaine use

INTRODUCTION

Hepatitis C virus (HCV) infection is related with several liver diseases such as cirrhosis and hepatocellular carcinomas, leading to more than 0.5 million deaths every year and to a great global burden. It is known that injection drug users show a high prevalence of HCV infection, being considered a risk group for this disease. Cocaine users seem to be in greater risk than other drug users, and several hypotheses for this association are being studied.

AIM

To review data on HCV infection in cocaine users, taking into consideration the relevance of the different routes of drug administration and other risk behaviors.

METHODS

This was a narrative review performed in the main scientific databases.

RESULTS AND CONCLUSION

Data suggest that cocaine use could be associated with HCV infection due to the specificities of cocaine consumption pattern, even in those subjects who do not inject drugs, in addition to other risky behaviors, such as tattooing and unprotected sex. Injectable cocaine users seem to be more susceptible to contamination than users who do not inject drugs. However, evidence is pointing to the possibility of infection by sharing drug paraphernalia other than syringes. Moreover, specific immune system impairments caused by cocaine use are also being linked with HCV infection susceptibility, persistence and increased pathological effects.

Not just heroin: Extensive polysubstance use among US high school seniors who currently use heroin

BACKGROUND

Heroin-related deaths are on the rise in the US and a large portion of heroin overdoses involve co-use of other drugs such as benzodiazepines. A better understanding of heroin polysubstance use patterns could help discern better prevention measures.

METHODS

Data were examined from past-month ("current") heroin users from a nationally representative sample of high school seniors in the Monitoring the Future study (2010-2016, n = 327). We examined how past-month use and frequency of use of various drugs relate to frequency of current heroin use using chi-square and multivariable ordinal logistic regression.

RESULTS

Prevalence of any past-month use of various other drugs (and past-month use 10+ times) tends to increase as the frequency of heroin use increases; however, other drug use tends to decline among those reporting the use of heroin 40+ times in the past month. In multivariable models controlling for demographic characteristics, most levels of alcohol use were associated with decreased odds of higher-frequency heroin use (ps<.05). Nonmedical opioid (aOR = 5.84, p = .037) and tranquilizer (aOR = 14.63, p = .045) use 40+ times in the past month were associated with increased odds of higher-frequency heroin use.

CONCLUSIONS

High school seniors who use heroin also use multiple other drugs. Increases in the frequency of heroin use are associated with shifts in the nature and frequency of polysubstance use, with a higher frequency of heroin use associated with the highest percentage and frequency of use of depressants (nonmedical opioid and benzodiazepine use), compounding the risk of overdose. Prevention measures should consider polysubstance use patterns among heroin-using adolescents.

Classification of miRNA-related sequence variations

miRNA regulome is whole set of regulatory elements that regulate miRNA expression or are under control of miRNAs. Its understanding is vital for comprehension of miRNA functions. Classification of miRNA-related genetic variability is challenging because miRNA interact with different genomic elements and are studied at different omics levels. In the present study, miRNA-associated genetic variability is presented at three levels: miRNA genes and their upstream regulation, miRNA silencing machinery and miRNA targets. Several types of miRNA-associated genetic variations are known, including short and structural polymorphisms and epimutations. Differential expression can also affect miRNA regulome function. Classification of miRNA-associated genetic variability presents a baseline for complementing sequence variant nomenclature, planning of experiments, protocols for multi-omics data integration and development of biomarkers.

Pharmacoepigenomics of opiates and methadone maintenance treatment: current data and perspectives

Current treatments of opioid addiction include primarily maintenance medications such as methadone. Chronic exposure to opiate and/or long-lasting maintenance treatment induce modulations of gene expression in brain and peripheral tissues. There is increasing evidence that epigenetic modifications underlie these modulations. This review summarizes published results on opioid-induced epigenetic changes in animal models and in patients. The epigenetic modifications observed with other drugs of abuse often used by opiate abusers are also outlined. Specific methadone maintenance treatment induced epigenetic modifications at different treatment stages may be combined with the ones resulting from patients’ substance use history. Therefore, research comparing groups of addicts with similar history and substances use disorders but contrasting for well-characterized treatment phenotypes should be encouraged.

Biochemical Diagnosis in Substance and Non-substance Addiction

An optimal biochemical marker for addiction would be some easily traced molecules in body specimens, which indicates indulgent addictive behaviors, or susceptibility to certain addictive stimuli. In this chapter, we discussed existing literature about possible biomarkers, and classified them into three categories: origin forms and metabolites of substances, markers from biochemical responses to certain addiction, and genetic and epigenetic biomarkers suggesting susceptibility to addiction. In every category, we examined studies concerning certain type of addiction one by one, with focuses mainly on opiates, psychostimulants, and pathological gambling. Several promising molecules were highlighted, including those of neurotrophic factors, inflammatory factors, and indicators of vascular injury, and genetic and epigenetic biomarkers such as serum miRNAs. DNA methylation signatures and signal nucleotide polymorphism of candidate gene underlying the addiction.

Nonmedical opioid use and heroin use in a nationally representative sample of us high school seniors

BACKGROUND

Nonmedical use of opioids has become increasingly problematic in recent years with increases in overdoses, treatment admissions, and deaths. Use also appears to be contributing to heroin initiation, which has increased in recent years. Further research is needed to examine which adolescents are at highest risk for nonmedical use of opioids and heroin and to explore potential links between nonmedical opioid use and heroin use.

METHODS

Data were analyzed from a nationally representative sample of American high school seniors in the Monitoring the Future study (2009-2013, Weighted N=67,822). We examined associations between frequency and recency of nonmedical use of opioids and heroin. Sociodemographic correlates of use of each drug were also examined.

RESULTS

12.4% of students reported lifetime nonmedical opioid use and 1.2% reported lifetime heroin use. As frequency of lifetime nonmedical opioid use increased, so too did the odds for reporting heroin use, with over three-quarters (77.3%) of heroin users reporting lifetime nonmedical opioid use. Recent (30-day) nonmedical opioid use was a robust risk factor for heroin use and almost a quarter (23.2%) of students who reported using opioids ≥40 times reported lifetime heroin use. Black and Hispanic students were less likely to report nonmedical opioid or heroin use than white students, but they were more likely to report heroin use in absence of nonmedical opioid use.

DISCUSSION

Recent and frequent nonmedical opioid use are risk factors for heroin use among adolescents. Prevention needs to be targeted to those at highest risk.

Serum adiponectin in HIV-1 and hepatitis C virus mono- and co-infected Kenyan injection drug users

Adiponectin is an important marker of anthropometric profiles of adipose tissue. However, association of adiponectin and adiposity in HIV mono- and co-infected and hepatitis (HCV) injection drug users (IDUs) has not been elucidated. Therefore, the relationship of total adiponectin levels with anthropometric indices of adiposity was examined in HIV mono-infected (anti-retroviral treatment, ART-naive, n=16 and -experienced, n=34); HCV mono-infected, n=36; HIV and HCV co-infected (ART-naive, n=5 and -experienced, n=13); uninfected, n=19 IDUs; and healthy controls, n=16 from coastal Kenya. Anthropometric indices of adiposity were recorded and total circulating adiponectin levels were measured in serum samples using enzyme-linked immunosorbent assay. Adiponectin levels differed significantly amongst the study groups (P<0.0001). Post-hoc analyses revealed decreased levels in HIV mono-infected ART-naive IDUs in comparison to uninfected IDUs (P<0.05) and healthy controls (P<0.05). However, adiponectin levels were elevated in HCV mono-infected IDUs relative to HIV mono-infected ART-naive (P<0.001) and -experienced (P<0.001) as well as HIV and HCV co-infected ART-naive (P<0.05) IDUs. Furthermore, adiponectin correlated with weight (ρ=0.687; P=0.003) and BMI (ρ=0.598; P=0.014) in HIV mono-infected ART-naive IDUs; waist circumference (ρ=-0.626; P<0.0001), hip (ρ=-0.561; P=0.001) circumference, and bust-to-waist ratio (ρ=0.561; P=0.001) in HIV mono-infected ART-experienced IDUs; waist girth (ρ=0.375; P=0.024) in HCV mono-infected IDUs; and waist-to-hip ratio (ρ=-0.872; P=0.048) in HIV and HCV co-infected ART-naive IDUs. Altogether, these results suggest suppression of adiponectin production in treatment-naive HIV mono-infected IDUs and that circulating adiponectin is a useful surrogate marker of altered adiposity in treatment-naive and -experienced HIV and HCV mono- and co-infected IDUs.

Heroin inhibits HIV-restriction miRNAs and enhances HIV infection of macrophages

Although opioids have been extensively studied for their impact on the immune system, limited information is available about the specific actions of opioids on intracellular antiviral innate immunity against HIV infection. Thus, we investigated whether heroin, one of the most abused drugs, inhibits the expression of intracellular HIV restriction microRNA (miRNA) and facilitates HIV replication in macrophages. Heroin treatment of macrophages enhanced HIV replication, which was associated with the downregulation of several HIV restriction miRNAs. These heroin-mediated actions on the miRNAs and HIV could be antagonized by naltrexone, an opioid receptor antagonist. Furthermore, the in vitro negative impact of heroin on HIV-associated miRNAs was confirmed by the in vivo observation that heroin addicts had significantly lower levels of macrophage-derived HIV restriction miRNAs than those in the control subjects. These in vitro and in vivo findings indicate that heroin use compromises intracellular anti-HIV innate immunity, providing a favorable microenvironment for HIV survival in the target cells.