Distribution of Phosphatidylethanol in Maternal and Fetal Compartments After Chronic Gestational Binge Alcohol Exposure

In Vivo Administration of Phosphatidic Acid, a Direct Alcohol Target Rescues Fetal Growth Restriction and Maternal Uterine Artery Dysfunction in Rat FASD Model

Fetal growth restriction is a hallmark of Fetal Alcohol Syndrome (FAS) and is accompanied by maternal uterine circulatory maladaptation. FAS is the most severe form of Fetal Alcohol Spectrum Disorder (FASD), a term for the range of conditions that can develop in a fetus when their pregnant mother consumes alcohol. Alcohol exerts specific direct effects on lipids that control fundamental developmental processes. We previously demonstrated that direct in vitro application of phosphatidic acid (PA, the simplest phospholipid and a direct target of alcohol exposure) to excised uterine arteries from alcohol-exposed rats improved vascular function, but it is unknown if PA can rescue end organ phenotypes in our FASD animal model. Pregnant Sprague-Dawley rats (n = 40 total dams) were gavaged daily from gestational day (GD) 5 to GD 19 with alcohol or maltose dextrin, with and without PA supplementation, for a total of four unique groups. To translate and assess the beneficial effects of PA, we hypothesized that in vivo administration of PA concomitant with chronic binge alcohol would reverse uterine artery dysfunction and fetal growth deficits in our FASD model. Mean fetal weights and placental efficiency were significantly lower in the binge alcohol group compared with those in the control (p < 0.05). However, these differences between the alcohol and the control groups were completely abolished by auxiliary in vivo PA administration with alcohol, indicating a reversal of the classic FAS growth restriction phenotype. Acetylcholine (ACh)-induced uterine artery relaxation was significantly impaired in the uterine arteries of chronic in vivo binge alcohol-administered rats compared to the controls (p < 0.05). Supplementation of PA in vivo throughout pregnancy reversed the alcohol-induced vasodilatory deficit; no differences were detected following in vivo PA administration between the pair-fed control and PA alcohol groups. Maximal ACh-induced vasodilation was significantly lower in the alcohol group compared to all the other treatments, including control, control PA, and alcohol PA groups (p < 0.05). When analyzing excitatory vasodilatory p1177-eNOS, alcohol-induced downregulation of p1177-eNOS was completely reversed following in vivo PA supplementation. In summary, these novel data utilize a specific alcohol target pathway (PA) to demonstrate a lipid-based preventive strategy and provide critical insights important for the development of translatable interventions.

[Determination of phosphatidylethanol in whole-blood by liquid chromatography-tandem mass spectrometry based on intelligent scheduled time-zone acquisition technology and the application to population level survey]

Alcohol intake is an important risk factor for cardiovascular disease， liver disease， and diabetes. The accurate and objective evaluation of alcohol intake is important for disease prevention and intervention， as well as alcohol intake monitoring. Phosphatidylethanol （PEth） is a potential clinical biomarker of alcohol consumption. Monitoring PEth levels can provide an objective and quantitative basis for alcohol intake studies. Unlike other current alcohol biomarkers， PEth can only be produced in the presence of alcohol. Therefore， PEth is highly specific for alcohol intake and not affected by confounding factors， such as age， gender， hypertension， kidney disease， liver disease， and other comorbidities. Because of its long half-life and high specificity for alcohol intake， PEth may be used as a tool for monitoring drinking behavior in the clinical， transportation， and other fields. Given rapid developments in mass spectrometry technology over the past decade， liquid chromatography-tandem mass spectrometry （LC-MS/MS） has become the preferred method for PEth detection. However， most current LC-MS/MS methods focus on the determination of one or several PEth homologs， and the number of PEth homologs that can be determined simultaneously is relatively limited. Moreover， the detection capacity of the available methods remains insufficient， and their analytical sensitivity for some PEth homologs must be further improved. In this study， a novel LC-MS/MS method based on an intelligent scheduled time-zone negative multiple reaction monitoring acquisition technology （Scheduled-MRM） was developed. The technology monitors two ion channels in each PEth to ensure reliable results and can quantify 18 PEth homologs in human whole blood simultaneously. Methanol-methyl tert-butyl ether-water was used as the extraction system. An XBridge C18 column （100 mm×2.1 mm， 3.5 μm） was selected for gradient elution with 2.5 mmol/L ammonium acetate isopropanol solution and 2.5 mmol/L ammonium acetate aqueous solution-acetonitrile （50∶50， v/v） as the mobile phases. Negative electronic spray ionization in scheduled-MRM mode was applied for MS/MS detection. The method was validated to have a linear range of 10-2500 ng/mL with correlation coefficients greater than 0.9999. The limits of detection and quantification were 0.7-2.8 and 2.2-9.4 ng/mL， respectively， and the spiked recoveries ranged from 91.0% to 102.2%. The method was confirmed to be simple， rapid， and precise， and subsequently validated for the measurement of 18 PEth homologs in human blood. Scheduled-MRM can assign a suitable scan time to each ion channel and effectively reduce the number of concurrent ion pairs monitored per unit time. This technology overcomes the problem of insufficient dwell time caused by an excessive number of ion channels， thereby avoiding the redundant monitoring of non-retention times. Scheduled-MRM significantly improved the detection sensitivity， data acquisition quality， and signal response of the proposed method. Whole blood samples from 359 volunteers with regular drinking habits were analyzed using this method. The total PEth concentrations ranged from 51.13 ng/mL to 2.89 μg/mL， with a mean of 363.16 ng/mL. PEth 16∶0/18∶1 and 16∶0/18∶2 were the two most abundant homologs， with mean concentrations of 74.21 and 48.75 ng/mL， accounting for approximately 20.43% and 13.42%， respectively， of the total PEth. Spearman correlation analyses showed that the PEth homologs correlated well with each other， γ-glutamyltransferase， a clinically available biological marker of alcohol， and other clinical biochemical parameters related to liver and kidney function. Overall， the method was demonstrated to be sensitive， precise， and accurate； thus， it may be an effective tool for monitoring alcohol intake in the clinical and other fields.

Interaction of Alcohol & Phosphatidic Acid in Maternal Rat Uterine Artery Function

Alcohol has been demonstrated to impair maternal uterine arterial adaptations in Fetal Alcohol Spectrum Disorder (FASD) animal models. However, the exact mechanism remains inconclusive. We hypothesized that phosphatidic acid (PA), a direct target of alcohol metabolism, would alleviate alcohol-induced vascular dysfunction of the maternal uterine artery. Mean fetal weight, and crown-rump length of the alcohol administered rats were ~9% and 7.6% lower than the pair-fed control pups, respectively. Acetylcholine (Ach)-induced uterine artery relaxation was significantly impaired in uterine arteries of alcohol-administered rats (P<0.05). Supplementation of 10^-5M PA reversed alcohol-induced vasodilatory deficit; no difference was detected after PA treatment between pair-fed control and alcohol groups (P=0.37). There was a significant interaction between PA concentrations and alcohol exposure (PA X Alcohol effect, P<0.0001). Pair-wise comparisons showed a concentration-dependent vasodilatory effect on uterine arteries of the alcohol-administered rats, with % relaxation significantly improved at PA concentrations > 10^-7 M (P<0.05). Alcohol significantly reduced vasodilatory P-Ser1177 endothelial nitric oxide synthase (eNOS) levels in the uterine artery (↓90.7%; P=0.0029). PA treatment significantly reversed P-Ser1177 eNOS level in alcohol uterine arteries (153.7%↑; P=0.005); following ex vivo PA, there was no difference in P-Ser1177 eNOS levels between Control and Alcohol. Neither alcohol treatment nor PA affected total eNOS levels. Our data provide the first evidence of the interaction of alcohol and PA in rat maternal uterine artery vascular function and demonstrates PA's relationship with the eNOS system. Overall, the current study demonstrates that PA may be a promising therapeutic molecule of interest in alcohol-related gestational vascular dysfunction.

Morphological alteration in rat hippocampal neuronal dendrites following chronic binge prenatal alcohol exposure

Prenatal alcohol exposure (PAE) may result in Fetal Alcohol Spectrum Disorders (FASD). The hippocampus has been recognized as a vulnerable target to alcohol-induced developmental damage. However, the effect of prenatal exposure to alcohol on dendritic morphological adaptations throughout the hippocampal fields in the developing brain still remains largely unknown in the context of FASD. We hypothesized that chronic binge alcohol exposure during pregnancy alters dendrite arborization throughout the developing rat hippocampus. Pregnant Sprague-Dawley rats were assigned to either a pair-fed control (PF-Cont) or a binge alcohol (Alcohol) treatment group. Alcohol dams were acclimatized via a once-daily orogastric gavage of 4.5 g/kg alcohol from gestational day (GD) 5-10 and progressed to 6 g/kg alcohol from GD 11-21. Pair-fed dams similarly received isocaloric maltose dextrin. After parturition, all dams received an ad libitum diet and nursed their offspring until postnatal day (PND) 10 when the pup brains were collected for morphological analysis. PAE increased dendritic arborization and complexities of CA1, CA2/3, and DG neurons in the PND 10 rat hippocampus. The number of primary dendrites, total dendritic length, and number of dendritic branches were significantly increased following PAE, and Sholl analysis revealed significantly more intersections of the dendritic processes in PND 10 offspring following PAE compared with those in the PF-Cont group. We conclude that chronic binge PAE significantly alters hippocampal dendritic morphology in the developing hippocampus. We conjecture that this morphological alteration in postnatal rat hippocampal dendrites following chronic binge prenatal alcohol exposure may play a critical role in FASD neurobiological phenotypes.

Phosphatidylethanol as Blood Biomarker of Alcohol Consumption in Early Pregnancy: An Observational Study in 4,067 Pregnant Women

BACKGROUND

The teratogenic effects of alcohol are well documented, but there is a lack of screening methods to detect alcohol use during pregnancy. Phosphatidylethanol 16:0/18:1 (PEth) is a specific and sensitive biomarker reflecting alcohol intake up to several weeks after consumption. The aim of this study was to investigate the prevalence of positive PEth values as an indicator of early prenatal alcohol exposure in a general population of pregnant women.

METHODS

Rhesus typing is routinely performed in Norway in all pregnancies around gestational week 12. Rhesus-negative women have an additional test taken around week 24. Blood samples submitted to St. Olav University Hospital in Trøndelag, Norway, for Rhesus typing during the period September 2017 to October 2018 were collected. A total of 4,533 whole blood samples from 4,067 women were analyzed for PEth (limit of quantification of 0.003 µM).

RESULTS

Fifty-eight women had a positive PEth sample. Of these, 50 women were positive around gestational week 12, 3 women were positive around week 24, and in 5 cases, the timing was unknown. There were no significant differences in proportions of women with positive PEth values related to age, or rural versus urban residency.

CONCLUSION

In an unselected pregnant population in Norway, 1.4% had a positive PEth sample around gestational week 12, whereas 0.4% had a positive sample around week 24. The use of PEth as an alcohol biomarker should be further investigated as a diagnostic tool in the antenatal setting.