Fatemeh Akhlaghi

Introduction: Hepatic lipid accumulation (steatosis) is an early indicator of non-alcoholic fatty liver disease (NAFLD), preceding fibrosis and cirrhosis. Understanding its effects on drug-me-tabolizing enzymes (DMEs) and transporters is crucial for assessing potential alterations in drug dis-position among NAFLD patients. This study aimed to replicate steatosis in an in vitro HepaRG cell model and analyze its impact on DMEs and transporters. Methods: Differentiated HepaRG cells were treated with a mixture of saturated (palmitate) and unsatu-rated (oleate) fatty acids (in a 1:2 ratio at 0.5 mM), complexed with BSA for 72 hours to induce lipid accumulation. Confirmation of steatosis was performed using Oil Red O staining and triglyceride (TG) quantification, while cell viability was assessed via the WST-1 assay. RNA sequencing and SWATH-MS proteomic analysis were employed to identify differentially expressed transcripts and proteins in lipid-loaded cells compared to controls. Results: Lipid loading resulted in a ~6-fold increase in TG concentration without compromising cell viability. Transcriptomic analysis identified 393 differentially expressed transcripts (89 upregulated, 304 downregulated), while proteomic analysis detected 165 differentially expressed proteins (127 up-regulated, 38 downregulated). Notably, key mRNA transcripts related to transcription factors (NR1I2, HNF4α), phase 1 DMEs (CYP1A2, 2B6, 2C8, 2C9, 2C19, 3A4), phase 2 DMEs (UGT1A6, 2B7, SULT2A1, 1E1), and transporters (ABCC11, ABCG5, SLCO2B1, SLC10A1) exhibited significant downregulation. Discussion: The observed alterations in DMEs and transporters suggest a potential shift in drug me-tabolism pathways under NAFLD conditions. Downregulation of transcription factors and metabolic enzymes could impact drug efficacy and toxicity, necessitating further research into the pharmacoki-netic implications. Conclusion: The in vitro hepatic steatosis model demonstrated significant changes in the expression of clinically relevant DMEs and transporters. These findings highlight the importance of considering NAFLD-induced metabolic alterations when assessing drug disposition in affected patients

BACKGROUND: Studies have demonstrated the role of ghrelin in alcohol-related behaviors and consumption. Blockade of the growth hormone secretagogue receptor (GHSR), which is the ghrelin receptor, has been shown to decrease alcohol drinking and reward-related behaviors across several animal models. We previously conducted a human study testing a GHSR inverse agonist/competitive antagonist, PF-5190457, in individuals who are heavy drinkers and showed its safety when coadministered with alcohol. Here, we conducted a phase IIa experimental medicine study in patients with alcohol use disorder (AUD) to investigate the effects of PF-5190457 on alcohol- and food-related outcomes. METHODS: Forty-two individuals with AUD ( n = 29 completers) participated in a randomized, double-blind, placebo-controlled study where they received PF-5190457 100mg b.i.d. (or placebo) in 2 counterbalanced, within-subject stages. Participants completed an alcohol cue-reactivity (CR) experiment in a bar-like laboratory and a virtual food choice experiment in a cafeteria-like virtual reality (VR) environment. A subset of participants ( n = 12) performed a CR task during a brain functional MRI (fMRI) experiment. RESULTS: PF-5190457 did not reduce cue-elicited alcohol craving. PF-5190457 reduced virtual calories selected ( P = 0.04) in the VR environment. PF-5190457 did not influence neural activation during CR task in the fMRI experiment. CONCLUSION: This study provides human evidence of the role of GHSR blockade in behaviors related to food selection and highlights the need for future investigations into targeting the ghrelin system in AUD. TRIAL REGISTRATION: ClinicalTrials.gov (accession no. NCT02707055). FUNDING: NIDA and NIAAA ZIA-DA000635; National Center for Advancing Translational Sciences UH2/UH3-TR000963.

A physiologically based pharmacokinetic (PBPK) modeling approach was used to simulate the concentration-time profile of ethanol (EtOH) in stomach, duodenum, plasma and other tissues upon consumption of beer and whiskey under fasted and fed conditions. A full PBPK model was developed for EtOH using the advanced dissolution, absorption and metabolism (ADAM) model fully integrated into the Simcyp Simulator® 15 (Simcyp Ltd., Sheffield, UK). The prediction performance of the developed model was verified and the EtOH concentration-time profile in different organs was predicted. Simcyp simulation showed ≤ 2-fold difference in values of EtOH area under the concentration-time curve (AUC) in stomach and duodenum as compared to the observed values. Moreover, the simulated EtOH maximum concentration (C_max), time to reach C_max (T_max) and AUC in plasma were comparable to the observed values. We showed that liver is exposed to the highest EtOH concentration, faster than other organs (C_max = 839.50 mg/L and T_max = 0.53 h), while brain exposure of EtOH (AUC = 1139.43 mg·h/L) is the highest among all other organs. Sensitivity analyses (SAs) showed direct proportion of EtOH rate and extent of absorption with administered EtOH dose and inverse relationship with gastric emptying time (GE) and steady-state volume of distribution (V_ss). The current PBPK model approach might help with designing in vitro experiments in the area of alcohol organ damage or alcohol-drug interaction studies.

Background and Objectives The ghrelin receptor (GHS-R1a) is a potential target for alcohol use disorders. PF-5190457 is the first inverse agonist of GHS-R1a to progress to clinical development with potential to treat alcohol use disorder. We present a population pharmacokinetic model for PF-5190457 in non-heavy (alcohol consumption status = 0) and heavy alcohol drinkers (alcohol consumption status = 1), and identify relevant factors that can influence its pharmacokinetics. Methods Plasma concentration–time data from non-heavy (n = 35) and heavy drinkers (n = 12) were pooled for the population pharmacokinetic model development. The influence of various covariates including alcohol consumption status was evaluated. The accuracy, precision, and robustness of the model were also evaluated using bootstrapping and visual predictive checks. Results A two-compartment model best described the pharmacokinetics of PF-5190457. The apparent volume of distribution of 44.5 L, apparent clearance of 72.0 L/h, apparent peripheral volume of distribution of 271 L, apparent distributional clearance of 28.7 L/h, and first-order absorption rate constant of 0.27/h were accurate and precise. The apparent volume of distribution was 3.8-fold higher (169 L) in heavy drinkers, and correlated with a lower maximum plasma concentration in heavy drinkers compared with non-heavy drinkers at the same dose; and a corresponding reduced incidence of somnolence in heavy drinkers at doses > 50 mg. Conclusions This work provides an accurate, precise, and robust two-compartment model that describes the pharmacokinetics of PF-5190457 and suggests a possible link of PF-5190457 pharmacokinetics with somnolence. Trial Registration ClinicalTrials.gov identifier numbers NCT01247896 and NCT02039349

Ghrelin is a gastric-derived peptide hormone with demonstrated impact on alcohol intake and craving, but the reverse side of this bidirectional link, i.e., the effects of alcohol on the ghrelin system, remains to be fully established. To characterize the downstream effects of alcohol on the ghrelin system, we examined the following: (1) plasma ghrelin levels across four human laboratory alcohol administration experiments with non-treatment seeking, heavy-drinking participants, (2) expression of ghrelin, ghrelin receptor, and ghrelin-O-acyltransferase (GOAT) genes (GHRL, GHSR, and MBOAT4 , respectively) in human post-mortem brain tissue from individuals with alcohol use disorder (AUD) vs. controls, (3) plasma ghrelin levels in Ghsr knockout and wild-type rats following intraperitoneal (i.p.) ethanol administration, (4) effect of ethanol on ghrelin secretion from gastric mucosa cells ex vivo and GOAT enzymatic activity in vitro, and (5) plasma ghrelin levels in rats following i.p. ethanol administration vs . an iso-caloric sucrose solution. Peripheral acyl- and total ghrelin levels significantly decreased following acute ethanol administration in humans. No difference in GHRL, GHSR, and MBOAT4 mRNA expression in the brain was observed between AUD vs. control post-mortem samples. In rats, acyl-ghrelin levels significantly decreased following i.p. ethanol administration in both genotype groups (Ghsr knockout and wild-type), while des-acyl-ghrelin was not affected by ethanol. No effect of ethanol was observed ex vivo on ghrelin secretion from gastric mucosa cells or in vitro on GOAT acylation activity. Lastly, we observed different effects of i.p. ethanol and sucrose solution on acyl- and des-acyl-ghrelin in rats despite administering amounts with equivalent caloric value. Ethanol acutely decreases peripheral ghrelin concentrations in humans and rats, and our findings suggest that this effect does not occur through interaction with ghrelin-secreting gastric mucosal cells, the ghrelin receptor, or the GOAT enzyme. Moreover, this effect does not appear to be proportional to caloric load. Our findings, therefore, suggest that ethanol does not suppress circulating ghrelin through direct interaction with the ghrelin system, or in proportion to the caloric value of alcohol, and may differentially affect ghrelin acylation and ghrelin peptide secretion.

Background Enzyme-mediated biotransformation of pharmacological agents is a crucial step in xenobiotic detoxification and drug disposition. Herein, we investigated the metabolism and physicochemical properties of the top 200 most prescribed drugs (established) as well as drugs approved by the US Food and Drug Administration (FDA) between 2005 and 2016 (newly approved). Objective Our objective was to capture the changing trends in the routes of administration, physicochemical properties, and prodrug medications, as well as the contributions of drug-metabolizing enzymes and transporters to drug clearance. Methods The University of Washington Drug Interaction Database (DIDB^®) as well as other online resources (e.g., CenterWatch.com, Drugs.com, DrugBank.ca, and PubChem.ncbi.nlm.nih.gov) was used to collect and stratify the dataset required for exploring the above-mentioned trends. Results Analyses revealed that ~ 90% of all drugs in the established and newly approved drug lists were administered systemically (oral or intravenous). Meanwhile, the portion of biologics (molecular weight > 1 kDa) was 15 times greater in the newly approved list than established drugs. Additionally, there was a 4.5-fold increase in the number of compounds with a high calculated partition coefficient (cLogP > 3) and a high total polar surface area (> 75 Ų) in the newly approved drug vs. the established category. Further, prodrugs in established or newly approved lists were found to be converted to active compounds via hydrolysis, demethylases, and kinases. The contribution of cytochrome P450 (CYP) 3A4, as the major biotransformation pathway, has increased from 40% in the established drug list to 64% in the newly approved drug list. Moreover, the role of CYP1A2, CYP2C19, and CYP2D6 were decreased as major metabolizing enzymes among the newly approved medications. Among non-CYP major metabolizers, the contribution of alcohol dehydrogenases/aldehyde dehydrogenases (ADH/ALDH) and sulfotransferases decreased in the newly approved drugs compared with the established list. Furthermore, the highest contribution among uptake and efflux transporters was found for Organic Anion Transporting Polypeptide 1B1 (OATP1B1) and P-glycoprotein (P-gp), respectively. Conclusions The higher portion of biologics in the newly approved drugs compared with the established list confirmed the growing demands for protein- and antibody-based therapies. Moreover, the larger number of hydrophilic drugs found in the newly approved list suggests that the probability of toxicity is likely to decrease. With regard to CYP-mediated major metabolism, CYP3A5 showed an increased involvement owing to the identification of unique probe substrates to differentiate CYP3As. Furthermore, the contribution of OATP1B1 and P-gp did not show a significant shift in the newly approved drugs as compared to the established list because of their broad substrate specificity.