Initial Pharmacological Characterization of a Major Hydroxy Metabolite of PF-5190457: Inverse Agonist Activity of PF-6870961 at the Ghrelin Receptor.

Preclinical and clinical studies have identified the ghrelin receptor [growth hormone secretagogue receptor (GHSR)1a] as a potential target for treating alcohol use disorder. A recent phase 1a clinical trial of a GHSR1a antagonist/inverse agonist, PF-5190457, in individuals with heavy alcohol drinking identified a previously undetected major hydroxy metabolite of PF-5190457, namely PF-6870961. Here, we further characterized PF-6870961 by screening for off-target interactions in a high-throughput screen and determined its in vitro pharmacodynamic profile at GHSR1a through binding and concentration-response assays. Moreover, we determined whether the metabolite demonstrated an in vivo effect by assessing effects on food intake in male and female rats. We found that PF-6870961 had no off-target interactions and demonstrated both binding affinity and inverse agonist activity at GHSR1a. In comparison with its parent compound, PF-5190457, the metabolite PF-6870961 had lower binding affinity and potency at inhibiting GHSR1a-induced inositol phosphate accumulation. However, PF-6870961 had increased inhibitory potency at GHSR1a-induced ß-arrestin recruitment relative to its parent compound. Intraperitoneal injection of PF-6870961 suppressed food intake under conditions of both food restriction and with ad libitum access to food in male and female rats, demonstrating in vivo activity. The effects of PF-6870961 on food intake were abolished in male and female rats knockout for GHSR, thus demonstrating that its effects on food intake are in fact mediated by the GHSR receptor. Our findings indicate that the newly discovered major hydroxy metabolite of PF-5190457 may contribute to the overall activity of PF-5190457 by demonstrating inhibitory activity at GHSR1a. SIGNIFICANCE STATEMENT: Antagonists or inverse agonists of the growth hormone secretagogue receptor (GHSR)1a have demonstrated substantial potential as therapeutics for alcohol use disorder. We here expand understanding of the pharmacology of one such GHSR1a inverse agonist, PF-5190457, by studying the safety and pharmacodynamics of its major hydroxy metabolite, PF-6870961. Our data demonstrate biased inverse agonism of PF-6870961 at GHSR1a and provide new structure-activity relationship insight into GHSR1a inverse agonism.

Hepatic Transporters Alternations Associated with Non-alcoholic Fatty Liver Disease (NAFLD): A Systematic Review.

BACKGROUND AND OBJECTIVES: Non-alcoholic fatty liver disease (NAFLD) is a progressive liver disorder and is usually accompanied by obesity, metabolic syndrome, and diabetes mellitus. NAFLD progression can lead to impaired functions of hepatocytes such as alternations in expression and function of hepatic transporters. The present study aimed to summarize and discuss the results of clinical and preclinical human studies that investigate the effect of NAFLD on hepatic transporters. METHODS: The databases of PubMed, Scopus, Embase, and Web of Science were searched systematically up to 1 March 2022. The risk of bias was assessed for cross-sectional studies through the Newcastle-Ottawa Scale score. RESULTS: Our review included ten cross-sectional studies consisting of 485 participants. Substantial alternations in hepatic transporters were seen during NAFLD progression to non-alcoholic steatohepatitis (NASH) in comparison with control groups. A significant reduction in expression and function of several hepatic uptake transporters, upregulation of many efflux transporters, downregulation of cholesterol efflux transporters, and mislocalization of canalicular transporter ABCC2 are associated with NAFLD progression. CONCLUSION: Since extensive changes in hepatic transporters could alter the pharmacokinetics of the drugs and potentially affect the safety and efficacy of drugs, close monitoring of drug administration is highly suggested in patients with NASH.

The glucagon-like peptide-1 system is modulated by acute and chronic alcohol exposure: Findings from human laboratory experiments and a post-mortem brain study.

Growing evidence suggests that the glucagon-like peptide-1 (GLP-1) system modulates alcohol seeking and consumption, and GLP-1 analogues may represent novel pharmacotherapies for alcohol use disorder (AUD). Accordingly, it is important to understand the potential effects of alcohol on the endogenous GLP-1 system. In a series of secondary analyses of previous human laboratory experiments, we first examined the effects of alcohol administration, with different doses and routes of administration, on peripheral active GLP-1 concentrations in heavy-drinking individuals with AUD enrolled in placebo-controlled pharmacological studies (only placebo conditions were analysed here). Alcohol administration resulted in a significant reduction of GLP-1 levels across the four experiments (oral alcohol, variable dose: F3,28 = 6.52, p = 0.002; oral alcohol, fixed dose: F7,75.94 = 5.08, p < 0.001; intravenous alcohol, variable dose: F4,37.03 = 20.72, p < 0.001; intravenous alcohol, fixed dose: F4,13.92 = 10.44, p < 0.001). Next, central expression of the GLP-1 receptor (GLP-1R) in post-mortem brain tissues (amygdala, ventral tegmental area, nucleus accumbens, hippocampus and prefrontal cortex) was compared between individuals with AUD and controls. Fold change of GLP-1R mRNA in the hippocampus was significantly higher in individuals with AUD, compared to controls (F1,21 = 6.80, p = 0.01). A trend-level effect with the same direction was also found in the prefrontal cortex (F1,20 = 3.07, p = 0.09). Exploratory analyses showed that GLP-1R gene expression levels were correlated with behavioural measures of alcohol drinking (hippocampus) and cigarette smoking (hippocampus and prefrontal cortex). Collectively, these data provide novel information on the crosstalk between alcohol and GLP-1 in a clinically relevant sample. Further studies are needed to understand the underlying mechanisms of this link.

A closer look at alcohol-induced changes in the ghrelin system: novel insights from preclinical and clinical data.

Ghrelin is a gastric-derived peptide hormone with demonstrated impact on alcohol intake and craving, but the reverse side of this bidirectional link, that is, the effects of alcohol on the ghrelin system, remains to be fully established. To further characterize this relationship, we examined (1) ghrelin levels via secondary analysis of human laboratory alcohol administration experiments with heavy-drinking participants; (2) expression of ghrelin, ghrelin receptor, and ghrelin-O-acyltransferase (GOAT) genes (GHRL, GHSR, and MBOAT4, respectively) in post-mortem brain tissue from individuals with alcohol use disorder (AUD) versus controls; (3) ghrelin levels in Ghsr knockout and wild-type rats following intraperitoneal (i.p.) alcohol administration; (4) effect of alcohol on ghrelin secretion from gastric mucosa cells ex vivo and GOAT enzymatic activity in vitro; and (5) ghrelin levels in rats following i.p. alcohol administration versus a calorically equivalent non-alcoholic sucrose solution. Acyl- and total-ghrelin levels decreased following acute alcohol administration in humans, but AUD was not associated with changes in central expression of ghrelin system genes in post-mortem tissue. In rats, alcohol decreased acyl-ghrelin, but not des-acyl-ghrelin, in both Ghsr knockout and wild-type rats. No dose-dependent effects of alcohol were observed on acyl-ghrelin secretion from gastric mucosa cells or on GOAT acylation activity. Lastly, alcohol and sucrose produced distinct effects on ghrelin in rats despite equivalent caloric value. Our findings suggest that alcohol acutely decreases peripheral ghrelin concentrations in vivo, but not in proportion to alcohol's caloric value or through direct interaction with ghrelin-secreting gastric mucosal cells, the ghrelin receptor, or the GOAT enzyme.

Alteration in Neuregulin 1/ERbB4 in Absence Epilepsy: Regulatory Effect on TRPV1 Expression.

Introduction: The footprint of Neuregulin 1 (NRG1) / ERbB4 in the pathophysiology of some neurological disorders and TRPV1 regulation has been indicated. The alterations in NRG1 and ErbB4 as well as the TRPV1 signaling pathway were investigated during the development of absence epilepsy in the genetic animal model of absence epilepsy. Methods: Male WAG/Rij and Wistar rats were divided into four experimental groups of two and six months of age. The protein levels of NRG1, ERbB4, and TRPV1 were measured in the somatosensory cortex and hippocampus. Results: The cortical protein levels of NRG1 and ErbB4 in the 6-month-old WAG/Rij rats were lower than in Wistar rats. Protein levels of TRPV1 were lower in two- and six-month-old WAG/Rij rats compared to age-matched Wistar rats.Hippocampal protein levels of NRG1 in 6-month-old WAG/Rij rats were lower than two-month-old WAG/Rij rats. Low levels of ErbB4 protein in two-month-old and high levels in six-month-old WAG/Rij rats were found compared to Wistar rats. Protein levels of TRPV1 were lower in the two-month-old and higher in the six-month-old WAG/Rij rats compared to age-matched Wistar rats.Furthermore, a high correlation between NRG1/ERbB4 and TRPV1 expressions in the cortex and hippocampus was indicated. The expression of NRG1/ERbB4 and TRPV1 followed a similar pattern during the life span of Wistar and WAG/Rij rats. Conclusion: Our findings indicated the potential role of the NRG1/ErbB4 pathway as well as TRPV1 in the pathogenesis of absence epilepsy. The regulatory effect of the ERbB4 receptor on the TRPV1 expression has been suggested following the similar pattern of expression.

Synthesis of PF-6870961, a major hydroxy metabolite of the novel ghrelin receptor inverse agonist PF-5190457.

Preclinical and human studies have indicated involvement of the ghrelin system in alcohol-related behaviors illuminating the possibility of using ghrelin receptor blockers as a pharmacological intervention for alcohol use disorder (AUD). Preliminary data from a recently conducted phase 1b human study with a ghrelin receptor inverse agonist, PF-5190457 (2-(2-methylimidazo[2,1-b][1,3thiazol-6-yl)-1-{2-(1R)-5-(6-methylpyrimidin-4-yl)-2,3-dihydro-1H-inden-1-yl]-2,7-diazaspiro[3.5]non-7-ylethanone), provided evidence on the safety and tolerability of this compound when co-administered with alcohol. Furthermore, the study revealed important information on the biotransformation pathways for this compound and prompted the discovery and then synthesis of a newly identified major metabolite, PF-6870961 ((R)-1-(2-(5-(2-hydroxy-6-methylpyrimidin-4-yl)-2,3-dihydro-1H-inden-1-yl)-2,7-diazaspiro[3.5]nonan-7-yl)-2-(2-methylimidazo[2,1-b]thiazol-6-yl)ethan-1-one). The metabolite was synthesized and fully characterized through a design that enabled it to be prepared in useful quantities. The synthesis provided direct access to the recently discovered PF-6870961 and is allowing researchers to conduct additional and deeper evaluation of its in vitro and in vivo properties.

Required warfarin dose and time in therapeutic range in patients with diagnosed Nonalcoholic Fatty Liver Disease (NAFLD) or Nonalcoholic Steatohepatitis (NASH).

Warfarin has been widely used to treat thromboembolism. The effect of nonalcoholic fatty liver disease (NAFLD) or nonalcoholic steatohepatitis (NASH), on warfarin dosing remains unknown. This study aims to examine the effects of NAFLD/NASH on the average daily dose (ADD) of warfarin and the time in therapeutic range (TTR). This is a retrospective study utilizing an administrative data. We included patients with at least 2 months of warfarin dispensing and two subsequent consecutive INR measures. The ADD of warfarin to achieve therapeutic range INR levels, and TTR were compared between patients with and without NAFLD/NASH in four subgroups of patients accounting for the presence of obesity and diabetes. Generalized linear models (GLM) with Propensity score (PS) fine stratification were applied to evaluate the relative differences (RD) of warfarin ADD and TTR (>60%) in four subgroups. A total of 430 NAFLD/NASH patients and 38,887 patients without NAFLD/NASH were included. The ADD and TTR, were not significant in the overall cohort between those with and without NAFLD/NASH. However, GLM results in patients without diabetes or obesity (N = 26,685) showed a significantly lower warfarin ADD (RD: -0.38; 95%CI: -0.74--0.02) and shorter TTR (OR: 0.71; 95%CI: 0.52-0.97) in patients diagnosed with NAFLD/NASH. The effects of NAFLD/NASH on warfarin dose or TTR were observed in patients without obesity and diabetes. Obesity and diabetes appear to be significant modifiers for the effects of NAFLD/NASH on warfarin dose and TTR.

Treprostinil reduces mitochondrial injury during rat renal ischemia-reperfusion injury.

BACKGROUND: Renal ischemia-reperfusion injury (IRI) is a major factor contributing to acute kidney injury and it is associated with a high morbidity and mortality if untreated. Renal IRI depletes cellular and tissue adenosine triphosphate (ATP), which compromises mitochondrial function, further exacerbating renal tubular injury. Currently, no treatment for IRI is available. This study investigates the protective role of treprostinil in improving mitochondria biogenesis and recovery during rat renal IRI. METHODS: Male Sprague Dawley rats were randomly assigned to groups: control, sham, IRI-placebo or IRI-treprostinil and subjected to 45 min of bilateral renal ischemia followed by 1-72 h reperfusion. Placebo or treprostinil (100 ng/kg/min) was administered subcutaneously via an osmotic minipump. RESULTS: Treprostinil significantly reduced peak elevated serum creatinine (SCr) levels and accelerated normalization relative to IRI-placebo (p < 0.0001). Treatment with treprostinil also inhibited IRI-mediated renal apoptosis, mitochondrial oxidative injury (p < 0.05), and the release of cytochrome c (p < 0.01) vs. IRI-placebo. In addition, treprostinil preserved renal mitochondrial DNA copy number (p < 0.0001) and renal ATP levels (p < 0.05) to nearly those of sham-operated animals. Non-targeted semi-quantitative proteomics showed reduced levels of ATP synthase subunits in the IRI-placebo group which were restored to sham levels by treprostinil treatment (p < 0.05). Furthermore, treprostinil reduced renal IRI-induced upregulated Drp1 and pErk protein levels, and restored Sirt3 and Pgc-1α levels to baseline (p < 0.05). CONCLUSIONS: Treprostinil reduces mitochondrial-mediated renal apoptosis, inhibits mitochondria fission, and promotes mitochondria fusion, thereby accelerating mitochondrial recovery and protecting renal proximal tubules from renal IRI. These results support the clinical investigation of treprostinil as a viable therapy to reduce renal IRI.

Effect of oral alcohol administration on plasma cytokine concentrations in heavy drinking individuals.

BACKGROUND: Alcohol is known to modulate the immune system, including cytokines, under conditions of both acute consumption and chronic use. The specific pro- and anti-inflammatory effects and mechanisms whereby alcohol consumption modulates circulating cytokine concentrations are not well understood. Few studies in humans have investigated the effect of acute alcohol consumption on plasma cytokine concentrations in individuals who are heavy drinkers. METHODS: Data were pooled from two studies involving a total of 25 non-treatment seeking, heavy drinking individuals who undertook an oral alcohol administration procedure. Plasma cytokine [Interleukin-10 (IL-10), Interleukin-6 (IL-6), Interleukin-18 (IL-18) and Tumor Necrosis Factor-alpha (TNF-α)] concentrations were measured at two baseline timepoints, then three hours after alcohol administration, and finally when breath alcohol concentrations returned to zero. Linear mixed models were conducted to determine whether there was a significant effect of time on cytokine concentrations. RESULTS: There was a significant reduction in TNF-α concentration (F [3, 20.42] = 4.96, p = 0.01, η2p = 0.42) post alcohol administration, compared to baseline concentrations, and a significant increase in IL-6 concentrations (F [3, 27.81] = 9.06, p < 0.001, η2p = 0.49) post alcohol administration, compared to baseline. There were no significant changes in IL-18 or IL-10 concentrations. CONCLUSIONS: To our knowledge, this is the first study to examine the acute effect of oral alcohol consumption on peripheral inflammatory markers in individuals with alcohol use disorder. Results indicate a clinically relevant increase in proinflammatory cytokines approximately 3 h after initial alcohol ingestion. Further research should be done to elucidate the complex interaction between alcohol and the immune system.

Neuroendocrine Response to Exogenous Ghrelin Administration, Combined With Alcohol, in Heavy-Drinking Individuals: Findings From a Randomized, Double-Blind, Placebo-Controlled Human Laboratory Study.

BACKGROUND: Accumulating evidence has established a role for the orexigenic hormone ghrelin in alcohol-seeking behaviors. Accordingly, the ghrelin system may represent a potential pharmacotherapeutic target for alcohol use disorder. Ghrelin modulates several neuroendocrine pathways, such as appetitive, metabolic, and stress-related hormones, which are particularly relevant in the context of alcohol use. The goal of the present study was to provide a comprehensive assessment of neuroendocrine response to exogenous ghrelin administration, combined with alcohol, in heavy-drinking individuals. METHODS: This was a randomized, crossover, double-blind, placebo-controlled human laboratory study, which included 2 experimental alcohol administration paradigms: i.v. alcohol self-administration and i.v. alcohol clamp. Each paradigm consisted of 2 counterbalanced sessions of i.v. ghrelin or placebo administration. Repeated blood samples were collected during each session, and peripheral concentrations of the following hormones were measured: leptin, glucagon-like peptide-1, pancreatic polypeptide, gastric inhibitory peptide, insulin, insulin-like growth factor-1, cortisol, prolactin, and aldosterone. RESULTS: Despite some statistical differences, findings were consistent across the 2 alcohol administration paradigms: i.v. ghrelin, compared to placebo, increased blood concentrations of glucagon-like peptide-1, pancreatic polypeptide, cortisol, and prolactin, both acutely and during the whole session. Lower levels of leptin and higher levels of aldosterone were also found during the ghrelin vs placebo session. CONCLUSION: These findings, gathered from a clinically relevant sample of heavy-drinking individuals with alcohol use disorder, provide a deeper insight into the complex interplay between ghrelin and appetitive, metabolic, and stress-related neuroendocrine pathways in the context of alcohol use.

An 'Omics Approach to Unraveling the Paradoxical Effect of Diet on Perfluorooctanesulfonic Acid (PFOS) and Perfluorononanoic Acid (PFNA)-Induced Hepatic Steatosis.

Perfluoroalkyl substances (PFAS) are a family of toxicants universally detected in human serum and known to cause dyslipidemia in animals and humans. Hepatic steatosis, which is defined as lipid deposition in the liver, is known to be a consequence of poor diet. Similarly, PFAS are known to induce hepatic steatosis in animals on a low-fat chow. This study explored diet-PFAS interactions in the liver and their potential to modulate hepatic steatosis. Male C57BL/6J mice were fed with either a low-fat diet (10% kcal from fat, LFD) or a moderately high-fat diet (45% kcal from fat, HFD) with or without perfluorooctanesulfonic acid (3 ppm, PFOS) or perfluorononanoic acid (3 ppm, PFNA) in feed for 12 weeks. Livers were excised for histology and quantification of PFAS and lipids. The PFOS and PFNA coadministration with HFD reduced the hepatic accumulation of lipid and PFAS relative to the LFD treatment groups. Furthermore, transcriptomic analysis revealed that PFAS administration in the presence of an HFD significantly reduces expression of known hepatic PFAS uptake transporters, organic anion transporter proteins. Transcriptomics and proteomics further revealed several pathways related to lipid metabolism, synthesis, transport, and storage that were modulated by PFAS exposure and further impacted by the presence of dietary fat. Both dietary fat content and the chemical functional head group exerted significant influence on hepatic PFAS accumulation and the resulting biochemical signature, suggesting that diet and structure should be considered in the design and interpretation of research on PFAS induced hepatic steatosis.

A deeper insight into how GABA-B receptor agonism via baclofen may affect alcohol seeking and consumption: lessons learned from a human laboratory investigation.

Previous studies suggest that GABA-B receptor agonism may represent an effective pharmacological approach to treat addictive disorders. Baclofen is a selective GABA-B receptor agonist which has been investigated as a potential treatment for alcohol use disorder. However, research is needed to understand the biobehavioral mechanisms underlying baclofen's effect on alcohol use. In the present randomized, double-blind, placebo-controlled study, thirty-four alcohol-dependent individuals were randomized to receive baclofen (30 mg/d) or placebo for a week, and then participated in a laboratory experiment consisting of three procedures: alcohol cue-reactivity, priming, and self-administration. During the experiment, craving and other subjective responses to alcohol were assessed, and blood samples were collected for pharmacokinetic measurements. The effects of baclofen on the relationships between different alcohol-related laboratory parameters were investigated. Baclofen pharmacokinetic parameters and their correlations with behavioral measures were also examined. Results showed that baclofen disrupted the link between alcohol priming and self-administration, as indicated by significant interaction effects between drug condition (baclofen vs. placebo) and some of the priming variables (alcohol craving: F3,9 = 6.03, p = 0.01; alcohol sedation: F3,6 = 7.16, p = 0.01) on the total amount of alcohol self-administered. Considerable interindividual variability in baclofen pharmacokinetic parameters was observed. Maximum plasma concentrations of baclofen negatively correlated with cue-induced alcohol craving (r = -0.57, p = 0.03) and priming-induced ratings of 'like more' (r = -0.59, p = 0.02). In conclusion, baclofen may work by dissociating the link between an initial drink (priming) and subsequent alcohol consumption (self-administration). Considerable pharmacokinetic variability is an important factor to take into account when employing baclofen as a treatment for alcohol use disorder.

Anti-neuroinflammatory effects of a food-grade phenolic-enriched maple syrup extract in a mouse model of Alzheimer's disease.

Objectives: Alzheimer's disease (AD) is a growing global health crisis exacerbated by increasing life span and an aging demographic. Convergent lines of evidence, including genome-wide association studies, strongly implicate neuroinflammation in the pathogenesis of AD. Several dietary agents, including phenolic-rich foods, show promise for the prevention and/or management of AD, which in large part, has been attributed to their anti-inflammatory effects. We previously reported that a food-grade phenolic-enriched maple syrup extract (MSX) inhibited neuroinflammation in vitro but whether these effects are translatable in vivo remain unknown. Herein, we assessed MSX's ability to attenuate early neuroinflammation in a transgenic mouse model of AD.Methods: The effects of MSX on AD-related neuroinflammation was evaluated by orally administering MSX (100 and 200 mg/kg/day for 30 days) to the 3xTg-AD mouse model of AD. The expression of inflammatory markers in mouse brains were analyzed with LC-MS/MS with SWATH acquisition.Results: 3xTg-AD mice dosed orally with MSX have decreased expression of several inflammatory proteins, including, most notably, the AD risk-associated protein 'triggering receptor expressed on myeloid cells-2' (TREM2), and stimulator of interferon genes TMEM173, and suppressor of cytokine signaling-6 (SOCS6). However, this decrease in inflammation did not coincide with a decrease in pathogenic amyloid generation or lipid peroxidation.Discussion: These data demonstrate that oral administration of this maple syrup derived natural product reduces key neuroinflammatory indices of AD in the 3xTg-AD model of AD. Therefore, further studies to investigate MSX's potential as a dietary intervention strategy for AD prevention and/or management are warranted.

A Population Pharmacokinetic Analysis of PF-5190457, a Novel Ghrelin Receptor Inverse Agonist in Healthy Volunteers and in Heavy Alcohol Drinkers.

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.

Development of a Physiologically Based Pharmacokinetic Model for Prediction of Ethanol Concentration-Time Profile in Different Organs.

AIMS: 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. METHODS: 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. RESULTS: 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 (Cmax), time to reach Cmax (Tmax) 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 (Cmax = 839.50 mg/L and Tmax = 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 (Vss). CONCLUSIONS: The current PBPK model approach might help with designing in vitro experiments in the area of alcohol organ damage or alcohol-drug interaction studies.

Treprostinil, a prostacyclin analog, ameliorates renal ischemia-reperfusion injury: preclinical studies in a rat model of acute kidney injury.

BACKGROUND: Renal ischemia-reperfusion injury (IRI) is a major factor causing acute kidney injury (AKI). No pharmacological treatments for prevention or amelioration of I/R-induced renal injury are available. Here we investigate the protective effects of treprostinil, a prostacyclin analog, against renal IRI in vivo. METHODS: Male Sprague Dawley rats were subjected to bilateral renal ischemia (45 min) followed by reperfusion for 1-168 h. Treprostinil (100 ng/kg/min) or placebo was administered subcutaneously for 18-24 h before ischemia. RESULTS: Treatment with treprostinil both significantly reduced peak elevation and accelerated the return to baseline levels for serum creatinine and blood urea nitrogen versus I/R-placebo animals following IRI. I/R-treprostinil animals exhibited reduced histopathological features of tubular epithelial injury versus I/R-placebo animals. IRI resulted in a marked induction of messenger RNA coding for kidney injury biomarkers, kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin and for pro-inflammatory cytokines chemokine (C-C motif) ligand 2, interleukin 1ß, interleukin 6 and intracellular adhesion molecular 1 in animals treated with placebo only relative to sham controls. Upregulation of expression of all these genes was significantly suppressed by treprostinil. Treprostinil significantly suppressed the elevation in renal lipid peroxidation found in the I/R-placebo group at 1-h post-reperfusion. In addition, renal protein expression of cleaved poly(ADP-ribose) polymerase 1 and caspase-3, -8 and -9 in I/R-placebo animals was significantly inhibited by treprostinil. CONCLUSIONS: This study demonstrates the efficacy of treprostinil in ameliorating I/R-induced AKI in rats by significantly improving renal function early post-reperfusion and by inhibiting renal inflammation and tubular epithelial apoptosis. Importantly, these data suggest that treprostinil has the potential to serve as a therapeutic agent to protect the kidney against IRI in vivo.

Short-term treatment with dabigatran alters protein expression patterns in a late-stage tau-based Alzheimer's disease mouse model.

Proteins that regulate the coagulation cascade, including thrombin, are elevated in the brains of Alzheimer's disease (AD) patients. While studies using amyloid-based AD transgenic mouse models have implicated thrombin as a protein of interest, the role of thrombin in tau-based animal models has not been explored. The current study aims to determine how inhibiting thrombin could alter oxidative stress, inflammation, and AD-related proteins in a tau-based mouse model, the Tg4510. Aged Tg4510 mice were treated with the direct thrombin inhibitor dabigatran or vehicle for 7 days, brains collected, and western blot and data-independent proteomics using mass spectrometry with SWATH-MS acquisition performed to evaluate proteins related to oxidative stress, intracellular signaling, inflammation, and AD pathology. Dabigatran reduced iNOS, NOX4, and phosphorylation of tau (S396, S416). Additionally, dabigatran treatment increased expression of several signaling proteins related to cell survival and synaptic function. Increasing evidence supports a chronic procoagulant state in AD, highlighting a possible pathogenic role for thrombin. Our data demonstrate that inhibiting thrombin produces alterations in the expression of proteins involved in oxidative stress, inflammation, and AD-related pathology, suggesting that thrombin-mediated signaling affects multiple AD-related pathways providing a potential future therapeutic target.

Perfluorooctanesulfonic acid (PFOS) administration shifts the hepatic proteome and augments dietary outcomes related to hepatic steatosis in mice.

Hepatic steatosis increases risk of fatty liver and cardiovascular disease. Perfluorooctanesulfonic acid (PFOS) is a persistent, bio-accumulative pollutant that has been used in industrial and commercial applications. PFOS administration induces hepatic steatosis in rodents and increases lipogenic gene expression signatures in cultured hepatocytes. We hypothesized that PFOS treatment interferes with lipid loss when switching from a high fat diet (HFD) to a standard diet (SD), and augments HFD-induced hepatic steatosis. Male C57BL/6 N mice were fed standard chow diet or 60% kCal high-fat diet (HFD) for 4 weeks to increase body weight. Then, some HFD mice were switched to SD and mice were further divided to diet only or diet containing 0.0003% PFOS, for six treatment groups: SD, HFD to SD (H-SD), HFD, SD + PFOS, H-SD + PFOS, or HFD + PFOS. After 10 weeks on study, blood and livers were collected. HFD for 14 weeks increased body weight and hepatic steatosis, whereas H-SD mice returned to SD measures. PFOS administration reduced body weight in mice fed a SD, but not H-SD or HFD. PFOS administration increased liver weight in H-SD + PFOS and HFD + PFOS mice. PFOS increased hepatic steatosis in H-SD and HFD groups. Hepatic mRNA expression and SWATH-MS proteomic analysis revealed that PFOS induced lipid and xenobiotic transporters, as well as metabolism pathways. Overall, the findings herein suggest that PFOS treatment did interfere with lipid loss associated with switch to a SD and similarly augmented hepatic lipid accumulation in mice established on an HFD.

Most Influential Physicochemical and In Vitro Assay Descriptors for Hepatotoxicity and Nephrotoxicity Prediction.

Drug-induced organ injury is a major reason for drug candidate attrition in preclinical and clinical drug development. The liver, kidneys, and heart have been recognized as the most common organ systems affected in safety-related attrition or the subject of black box warnings and postmarket drug withdrawals. In silico physicochemical property calculations and in vitro assays have been utilized separately in the early stages of the drug discovery and development process to predict drug safety. In this study, we combined physicochemical properties and in vitro cytotoxicity assays including mitochondrial dysfunction to build organ-specific univariate and multivariable logistic regression models to achieve odds ratios for the prediction of clinical hepatotoxicity, nephrotoxicity, and cardiotoxicity using 215 marketed drugs. The multivariable hepatotoxic predictive model showed an odds ratio of 6.2 (95% confidence interval (CI) 1.7-22.8) or 7.5 (95% CI 3.2-17.8) for mitochondrial inhibition or drug plasma Cmax >1 µM for drugs associated with liver injury, respectively. The multivariable nephrotoxicity predictive model showed an odds ratio of 5.8 (95% CI 2.0-16.9), 6.4 (95% CI 1.1-39.3), or 15.9 (95% CI 2.8-89.0) for drug plasma Cmax >1 µM, mitochondrial inhibition, or hydrogen-bond-acceptor atoms >7 for drugs associated with kidney injury, respectively. Conversely, drugs with a total polar surface area ≥75 Å were 79% (odds ratio 0.21, 95% CI 0.061-0.74) less likely to be associated with kidney injury. Drugs belonging to the extended clearance classification system (ECCS) class 4, where renal secretion is the primary clearance mechanism (low permeability drugs that are bases/neutrals), were 4 (95% CI 1.8-9.5) times more likely to to be associated with kidney injury with this data set. Alternatively, ECCS class 2 drugs, where hepatic metabolism is the primary clearance (high permeability drugs that are bases/neutrals) were 77% less likely (odds ratio 0.23 95% CI 0.095-0.54) to to be associated with kidney injury. A cardiotoxicity model was poorly defined using any of these drug physicochemical attributes. Combining in silico physicochemical properties descriptors along with in vitro toxicity assays can be used to build predictive toxicity models to select small molecule therapeutics with less potential to cause liver and kidney organ toxicity.

Effects of exogenous ghrelin administration and ghrelin receptor blockade, in combination with alcohol, on peripheral inflammatory markers in heavy-drinking individuals: Results from two human laboratory studies.

The ghrelin system has been garnering interest for its role in different neuropsychiatric disorders, including alcohol use disorder (AUD). Accordingly, targeting the ghrelin system is under investigation as a potential novel therapeutic approach. While alcohol provokes the immune system and inflammatory responses, ghrelin has potent immunomodulatory and anti-inflammatory properties. The present study aimed to shed light on the "crosstalk" between ghrelin and inflammation by examining the effects of exogenous ghrelin administration and ghrelin receptor blockade on peripheral inflammatory markers in the context of two human laboratory studies with alcohol administration. Non-treatment-seeking, heavy-drinking individuals with alcohol dependence, the majority of whom were African American males, were enrolled. In the first randomized, crossover, double-blind, placebo-controlled human laboratory study, participants underwent two experimental paradigms - an intravenous alcohol self-administration (IV-ASA) and an intravenous alcohol clamp (IV-AC) - each consisting of two counterbalanced sessions (ghrelin, placebo). A loading dose of intravenous ghrelin (3 mcg/kg) or placebo, followed by a continuous ghrelin (16.9 ng/kg/min) or placebo infusion was administered. In the second dose-escalating, single-blind, placebo-controlled human laboratory phase 1b study, participants were dosed with an oral ghrelin receptor blocker (PF-5190457) and underwent an oral alcohol challenge. Repeated blood samples were collected, and plasma concentrations of the following inflammatory markers were measured: C-reactive protein (CRP), interleukin (IL)-6, IL-10, IL-18, and tumor necrosis factor alpha (TNF-α). During the IV-ASA experiment, significant drug × time interaction effects were observed for IL-6 (F3,36 = 3.345, p = 0.030) and IL-10 (F3,53.2 = 4.638, p = 0.006), indicating that ghrelin, compared to placebo, significantly reduced blood concentrations of the proinflammatory cytokine IL-6, while increasing blood concentrations of the anti-inflammatory cytokine IL-10. No significant drug × time interaction effects were observed during the IV-AC experiment, possibly because of its much shorter duration and/or smaller sample. Treatment with PF-5190457, compared to placebo, had no significant effect on the inflammatory markers investigated. In conclusion, a supraphysiologic pharmacological challenge with exogenous ghrelin in heavy-drinking individuals produced anti-inflammatory effects in the context of intravenous alcohol administration. On the contrary, ghrelin receptor blockade did not lead to any change in the inflammatory markers included in this study. Mechanistic studies are required to better understand the interaction between ghrelin, alcohol, and inflammatory processes.