Biology subjects

Arnold, S. L. M.

Publications and source records attributed to Arnold, S. L. M..

3 recordsLinked to original sources

bioRxiv2026

Proteomic profiling of xenobiotic and nutrient transporters in human placenta of different gestational ages

BackgroundThe placenta serves a critical role in nutrient uptake and waste elimination for the developing fetus. The placenta is also responsible for the uptake and/or exchange of xenobiotics, including medications, between the maternal and fetal bloodstreams. An estimated 40-80% of women take medications or drugs during pregnancy for a variety of conditions. Very little is understood about fetal drug and nutrient exposure during pregnancy and how it may change over the course of fetal development. ObjectiveThis study aimed to characterize the abundance of transport proteins in placental tissue, which are important in modulating fetal nutrient and drug exposure, over the duration of pregnancy. Mass spectrometry-based global proteomic analysis revealed trends in the expression of thousands of proteins throughout gestation. Focusing on the membrane-associated proteome enabled an increased emphasis on the solute carrier and ATP-binding cassette families of transporter proteins that are critical for nutrient and xenobiotic transport across the maternal-fetal barrier. Study DesignUsing data-independent acquisition proteomics, relative abundance of proteins in placental tissue samples was profiled across all three trimesters of pregnancy (Trimester 1 = 16, Trimester 2 = 9, and Term = 9). Membrane fractions were generated to enrich membrane-associated proteins for proteomic analysis. Placental samples were grouped into randomized batches for membrane fraction generation and mass spectrometry analysis. Proteomic search results from each batch were imported into the R programming environment from Skyline, concatenated, and normalized as one data set for downstream analysis. ResultsA total of 6,331 proteins were detected across all samples with 4,210 proteins identified in every sample. Pathway analysis revealed that as gestational age increases, membrane-associated proteins involved in more complex metabolic pathways increase in relative abundance while those involved in extracellular remodeling events and simple organic ion transport tended to decrease. A total of 139 solute carrier and ATP-binding cassette transport proteins were identified in all samples, and 80 were identified in every sample. In general, membrane-associated proteins, including solute carrier and ATP-binding cassette transport proteins, were significantly enriched in placental tissue collected during early gestation compared to term placental tissue. ConclusionThis study presents a comprehensive profiling of membrane-associated proteomic changes during gestation and identifies significant gestational age associated abundance changes at the protein level in several transport protein families. The application of data-independent acquisition global proteomic techniques enabled in-depth analysis of thousands of proteomic changes across pregnancy in a single experiment. These data provide critical information to support future studies into the understanding of fetal exposure to xenobiotics and nutrients circulating in the maternal bloodstream.

pharmacology and toxicology↗

bioRxiv2026

Proteomic profiling of drug and nutrient transporter expression by small intestinal region in neonates, pediatrics, and adults

Transporters localized to the small intestinal epithelium govern the absorption of many orally administered drugs and nutrients, and thorough characterization of transporter protein abundance is key to accurate prediction of small molecule absorption. Previous studies have reported more than 100 solute carrier and ATP-binding cassette superfamilies expressed in the intestine, but only a small subset of these transporter proteins have been quantified in native intestinal tissue. In addition, a majority of published transporter abundance data for the intestine was collected with adult tissue. Here, we report the identification and relative quantification of 87 solute carrier and 18 ATP-binding cassette superfamily transporters by intestinal region in neonatal, pediatric, and adult small intestinal mucosa using data-independent acquisition mass spectrometry. This study identified transporters uniquely expressed by intestinal region in all three age groups and region-associated abundance for 23 SLC/ABC transporters in pediatrics and adults. The protein abundance data reported here provide a valuable resource for the prediction of nutrient and drug absorption and efflux across age and will inform future studies of specific transporters and age-associated differences in transporter abundance. Significance statementWe report the relative abundance of key xenobiotic transporters along the length of the small intestine in neonates, pediatrics, and adults based on data-independent acquisition mass spectrometry. Intestinal region-associated transporter expression was observed for drug transporters and under-studied nutrient transporters across age groups.

pharmacology and toxicology↗

bioRxiv2020

IlvY is an important regulator of Shigella infection in vitro and in vivo

Shigellosis results from oral ingestion of the Gram-negative bacteria Shigella, and symptoms include severe diarrhea and dysentery. In the absence of vaccines, small molecule antibacterial drugs have provided treatment options for shigellosis. However, Shigella drug resistance is rapidly emerging, and Shigella strains with resistance to both third-generation cephalosporins and azithromycin have been identified in Asia. A re-conceptualization is needed regarding the development of therapeutics that target bacterial pathogens in order to reduce resistance development and alteration of gut microbiota, which is depleted upon treatment with wide spectrum antibiotics, thereby increasing susceptibility to subsequent enteric infections. A more organism-specific approach is to develop agents targeting virulence factors such as toxins, adhesins, invasins, quorum sensing, and protein secretion systems. For Shigella, there is interest in targeting transcription factors essential for Shigella infection in vivo rather than specific effectors. Here we describe the importance of the Shigella transcription factor IlvY in Shigella virulence in vitro and in vivo. This work included the development of a novel, oral mouse model of Shigella infection with wild-type adult mice. Unlike previous models, mice do not require antibiotic pretreatment or diet modifications. This mouse model was used to demonstrate the importance of IlvY for Shigella in vivo survival and that deletion of ilvY impacts host responses to infection. These results illustrate that IlvY is a potential therapeutic target for the treatment of shigellosis. In addition, the novel mouse model provides an exciting new opportunity to investigate therapeutic efficacy against Shigella infection and host responses to infection.

microbiology↗