Interindividual Regulation of the Breast Cancer Resistance Protein/ABCG2 Transporter in Term Human Placentas.

The breast cancer resistance protein (BCRP/ABCG2) is a maternally-facing efflux transporter that regulates the placental disposition of chemicals. Transcription factors and gene variants are important regulatory factors that influence transporter expression. In this study, we sought to identify the genetic and transcriptional mechanisms underlying the interindividual expression of BCRP mRNA and protein across 137 term placentas from uncomplicated pregnancies. Placental expression of BCRP and regulatory transcription factor mRNAs was measured using multiplex-branched DNA analysis. BCRP expression and ABCG2 genotypes were determined using Western blot and Fluidigm Biomark genetic analysis, respectively. Placentas were obtained from a racially and ethnically diverse population, including Caucasian (33%), African American (14%), Asian (14%), Hispanic (15%), and mixed (16%) backgrounds, as well as unknown origins (7%). Between placentas, BCRP mRNA and protein varied up to 47-fold and 14-fold, respectively. In particular, BCRP mRNA correlated significantly with known transcription factor mRNAs, including nuclear factor erythroid 2-related factor 2 and aryl hydrocarbon receptor. Somewhat surprisingly, single-nucleotide polymorphisms (SNPs) in the ABCG2 noncoding regions were not associated with variation in placental BCRP mRNA or protein. Instead, the coding region polymorphism (C421A/Q141K) corresponded with 40%-50% lower BCRP protein in 421C/A and 421A/A placentas compared with wild types (421C/C). Although BCRP protein and mRNA expression weakly correlated (r = 0.25, P = 0.040), this relationship was absent in individuals expressing the C421A variant allele. Study results contribute to our understanding of the interindividual regulation of BCRP expression in term placentas and may help to identify infants at risk for increased fetal exposure to chemicals due to low expression of this efflux protein.

Low-dose Ketamine Does Not Improve Migraine in the Emergency Department: A Randomized Placebo-controlled Trial.

INTRODUCTION: Patients frequently present to the emergency department (ED) with migraine headaches. Although low-dose ketamine demonstrates analgesic efficacy for acute pain complaints in the ED, headaches have historically been excluded from these trials. This study evaluates the efficacy and safety of low-dose ketamine for treatment of acute migraine in the ED. METHODS: This randomized, double-blinded, placebo-controlled trial evaluated adults 18 to 65 years of age with acute migraine at a single academic ED. Subjects were randomized to receive 0.2 milligrams per kilogram of intravenous (IV) ketamine or an equivalent volume of normal saline. Numeric Rating Scale (NRS-11) pain scores, categorical pain scores, functional disability scores, side effects, and adverse events were assessed at baseline (T0) and 30 minutes post-treatment (T30). The primary outcome was between-group difference in NRS score reduction at 30 minutes. RESULTS: We enrolled 34 subjects (ketamine=16, placebo=18). Demographics were similar between treatment groups. There was no statistically significant difference in NRS score reductions between ketamine and placebo-treated groups after 30 minutes. Median NRS score reductions at 30 minutes were 1.0 (interquartile range [IQR] 0 to 2.25) for the ketamine group and 2.0 (IQR 0 to 3.75) for the placebo group. Between-group median difference at 30 minutes was -1.0 (IQR -2 to 1, p=0.5035). No significant differences between treatment groups occurred in categorical pain scores, functional disability scores, rescue medication request rate, and treatment satisfaction. Side Effect Rating Scale for Dissociative Anesthetics scores in the ketamine group were significantly greater for generalized discomfort at 30 minutes (p=0.008) and fatigue at 60 minutes (p=0.0216). No serious adverse events occurred in this study. CONCLUSION: We found that 0.2mg/kg IV ketamine did not produce a greater reduction in NRS score compared to placebo for treatment of acute migraine in the ED. Generalized discomfort at 30 minutes was significantly greater in the ketamine group. Overall, ketamine was well tolerated by migraine-suffering subjects. To optimize low-dose ketamine as an acute migraine treatment, future studies should investigate more effective dosing and routes of administration.

Effects of Wharton's jelly-derived mesenchymal stem cells on neonatal neutrophils.

BACKGROUND: Mesenchymal stem cells (MSCs) have been proposed as autologous therapy for inflammatory diseases in neonates. MSCs from umbilical cord Wharton's jelly (WJ-MSCs) are accessible, with high proliferative capacity. The effects of WJ-MSCs on neutrophil activity in neonates are not known. We compared the effects of WJ-MSCs on apoptosis and the expression of inflammatory, oxidant, and antioxidant mediators in adult and neonatal neutrophils. METHODS: WJ-MSCs were isolated, and their purity and function were confirmed by flow cytometry. Neutrophils were isolated from cord and adult blood by density centrifugation. The effects of neutrophil/WJ-MSC co-culture on apoptosis and gene and protein expression were measured. RESULTS: WJ-MSCs suppressed neutrophil apoptosis in a dose-dependent manner. WJ-MSCs decreased gene expression of NADPH oxidase-1 in both adult and neonatal neutrophils, but decreased heme oxygenase-1 and vascular endothelial growth factor and increased catalase and cyclooxygenase-2 in the presence of lipopolysaccharide only in adult cells. Similarly, generation of interleukin-8 was suppressed in adult but not neonatal neutrophils. Thus, WJ-MSCs dampened oxidative, vascular, and inflammatory activity by adult neutrophils, but neonatal neutrophils were less responsive. Conversely, Toll-like receptor-4, and cyclooxygenase-2 were upregulated in WJ-MSCs only in the presence of adult neutrophils, suggesting an inflammatory MSC phenotype that is not induced by neonatal neutrophils. CONCLUSION: Whereas WJ-MSCs altered gene expression in adult neutrophils in ways suggesting anti-inflammatory and antioxidant effects, these responses were attenuated in neonatal cells. In contrast, inflammatory gene expression in WJ-MSCs was increased in the presence of adult but not neonatal neutrophils. These effects should be considered in clinical trial design before WJ-MSC-based therapy is used in infants.