Publications by authors named "Theo K Bammler"

Mutations in GBA (glucosylceramidase beta), which encodes the lysosomal enzyme glucocerebrosidase (GCase), are the strongest genetic risk factor for the neurodegenerative disorders Parkinson's disease (PD) and Lewy body dementia. Recent work has suggested that neuroinflammation may be an important factor in the risk conferred by GBA mutations. We therefore systematically tested the contributions of immune-related genes to neuropathology in a Drosophila model of GCase deficiency.

View Article and Find Full Text PDF

Spatial transcriptomic profiling enables precise quantification of gene expression with simultaneous localization of expression profiles onto tissue structures. This new technology promises to improve our understanding of the disease mechanisms. Therefore, there is intense interest in applying these methods in clinical trials or as laboratory developed tests to aid in diagnosis of disease.

View Article and Find Full Text PDF

Insulin secretion is impaired in individuals with cystic fibrosis (CF), contributing to high rates of CF-related diabetes (CFRD) and substantially increasing disease burden. To develop improved therapies for CFRD, better knowledge of pancreatic pathology in CF is needed. Glucagon like peptide-1 (GLP-1) from islet α cells potentiates insulin secretion by binding GLP-1 receptors (GLP-1Rs) on β cells.

View Article and Find Full Text PDF

Our study was to characterize sarcopenia in C57BL/6J mice using a clinically relevant definition to investigate the underlying molecular mechanisms. Aged male (23-32 months old) and female (27-28 months old) C57BL/6J mice were classified as non-, probable-, or sarcopenic based on assessments of grip strength, muscle mass, and treadmill running time, using 2 SDs below the mean of their young counterparts as cutoff points. A 9%-22% prevalence of sarcopenia was identified in 23-26 month-old male mice, with more severe age-related declines in muscle function than mass.

View Article and Find Full Text PDF

The microgravity environment aboard the International Space Station (ISS) provides a unique stressor that can help understand underlying cellular and molecular drivers of pathological changes observed in astronauts with the ultimate goals of developing strategies to enable long- term spaceflight and better treatment of diseases on Earth. We used this unique environment to evaluate the effects of microgravity on kidney proximal tubule epithelial cell (PTEC) response to serum exposure and vitamin D biotransformation capacity. To test if microgravity alters the pathologic response of the proximal tubule to serum exposure, we treated PTECs cultured in a microphysiological system (PT-MPS) with human serum and measured biomarkers of toxicity and inflammation (KIM-1 and IL-6) and conducted global transcriptomics via RNAseq on cells undergoing flight (microgravity) and respective controls (ground).

View Article and Find Full Text PDF
Article Synopsis
  • Metabolic adaptations are crucial for survival, with the mitochondrial calcium uniporter playing a key role in managing energy supply by regulating mitochondrial functions and calcium signaling.
  • The study investigates the effects of uniporter loss and gain on metabolic pathways, revealing that loss of function increases proteins involved in branched-chain amino acid (BCAA) catabolism, while specifically suppressing this pathway in liver cancer cells with high mitochondrial calcium levels.
  • The research also highlights the upregulation of the transcription factor KLF15 due to uniporter loss, linking it to changes in liver metabolism and potential complications like hyperammonemia in cancer patients.
View Article and Find Full Text PDF

To further the development of an in vitro model which faithfully recapitulates drug disposition of orally administered drugs, we investigated the utility of human enteroid monolayers to simultaneously assess intestinal drug absorption and first-pass metabolism processes. We cultured human enteroid monolayers from three donors, derived via biopsies containing duodenal stem cells that were propagated and then differentiated atop permeable Transwell® inserts, and confirmed transformation into a largely enterocyte population via RNA-seq analysis and immunocytochemical (ICC) assays. Proper cell morphology was assessed and confirmed via bright field microscopy and ICC imaging of tight junction proteins and other apically and basolaterally localized proteins.

View Article and Find Full Text PDF

Background: The first spatially resolved transcriptomics platforms, GeoMx (Nanostring) and Visium (10x Genomics) were launched in 2019 and were recognized as the method of the year by in 2020. The subsequent refinement and expansion of these and other technologies to increase -plex, work with formalin-fixed paraffin-embedded tissue, and analyze protein in addition to gene expression have only added to their significance and impact on the biomedical sciences. In this perspective, we focus on two platforms for spatial transcriptomics, GeoMx and Visium, and how these platforms have been used to provide novel insight into kidney disease.

View Article and Find Full Text PDF

Prenatal exposure to maternal psychological stress is associated with increased risk for adverse birth and child health outcomes. Accumulating evidence suggests that preconceptional maternal stress may also be transmitted intergenerationally to negatively impact offspring. However, understanding of mechanisms linking these exposures to offspring outcomes, particularly those related to placenta, is limited.

View Article and Find Full Text PDF

Objective: To identify plasma miRNAs related to treatment failure in youth with type 2 diabetes (T2D).

Research Design And Methods: We examined whether a panel of miRNAs could predict treatment failure in training/test data sets among participants in the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) study (N = 209). We also examined whether individual miRNAs were associated with treatment failure.

View Article and Find Full Text PDF

Background: Our objective was to discover novel urinary biomarkers of antibiotic-associated nephrotoxicity using an ex-vivo human microphysiological system (MPS) and to translate these findings to a prospectively enrolled cystic fibrosis (CF) population receiving aminoglycosides and/or polymyxin E (colistin) for a pulmonary exacerbation.

Methods: We populated the MPS with primary human kidney proximal tubule epithelial cells (PTECs) from three donors and modeled nephrotoxin injury through exposure to 50 µg/mL polymyxin E for 72 h. We analyzed gene transcriptional responses by RNAseq and tested MPS effluents.

View Article and Find Full Text PDF

Background: Fatigue is prevalent in subarachnoid hemorrhage (SAH) survivors. Biological mechanisms underlying fatigue post-SAH are not clear. Inflammation may contribute to the development of fatigue.

View Article and Find Full Text PDF

There is increasing interest in the African spiny mouse (Acomys cahirinus) as a model organism because of its ability for regeneration of tissue after injury in skin, muscle, and internal organs such as the kidneys. A high-quality reference genome is needed to better understand these regenerative properties at the molecular level. Here, we present an improved reference genome for A.

View Article and Find Full Text PDF

Importance: The ability to predict neurodevelopmental impairment (NDI) for infants diagnosed with hypoxic ischemic encephalopathy (HIE) is important for parental guidance and clinical treatment as well as for stratification of patients for future neurotherapeutic studies.

Objectives: To examine the effect of erythropoietin on plasma inflammatory mediators in infants with moderate or severe HIE and to develop a panel of circulating biomarkers that improves the projection of 2-year NDI over and above the clinical data available at the time of birth.

Design, Setting, And Participants: This study is a preplanned secondary analysis of prospectively collected data from infants enrolled in the High-Dose Erythropoietin for Asphyxia and Encephalopathy (HEAL) Trial, which tested the efficacy of erythropoietin as an adjunctive neuroprotective therapy to therapeutic hypothermia.

View Article and Find Full Text PDF

Introduction: Traffic-related air pollution (TRAP), a common exposure, potentially impacts pregnancy through altered placental function. We investigated associations between prenatal TRAP exposure and placental gene expression.

Methods: Whole transcriptome sequencing was performed on placental samples from CANDLE (Memphis, TN) (n = 776) and GAPPS (Seattle and Yakima, WA) (n = 205), cohorts of the ECHO-PATHWAYS Consortium.

View Article and Find Full Text PDF
Article Synopsis
  • The placenta is essential for fetal development, handling metabolism and the transport of various substances between mother and fetus.
  • Researchers assessed the protein abundance related to xenobiotic and steroid disposal in human placental tissue and compared it to four different placental cell lines.
  • The findings indicate that the BeWo and JEG-3 cell lines are most representative of human placental tissue for studying how these substances are processed, especially in the presence of common environmental chemicals.
View Article and Find Full Text PDF
Article Synopsis
  • There is growing interest in the African spiny mouse as a model for studying tissue regeneration in various body systems.
  • A new reference genome has been developed using long Nanopore sequencing, providing better insights into its regenerative abilities.
  • This improved genome shows higher quality and continuity compared to earlier versions, aiding research on the mouse's unique regenerative processes.
View Article and Find Full Text PDF

Phthalates are ubiquitous plasticizer chemicals found in consumer products. Exposure to phthalates during pregnancy has been associated with adverse pregnancy and birth outcomes and differences in placental gene expression in human studies. The objective of this research was to evaluate global changes in placental gene expression via RNA sequencing in two placental cell models following exposure to the phthalate metabolite mono(2-ethylhexyl) phthalate (MEHP).

View Article and Find Full Text PDF

Introduction: Archived human placental tissue specimens are vital for studying placenta pathophysiology and toxicology. Proteomics analysis of placental tissue provides mechanistic and translational information, but the highly perfused and heterogenous nature of the placenta creates confounding technical variability. In this study, we developed an optimized proteomics-based approach to address the technical variability of proteomics data by normalizing blood contamination and cellular heterogeneity of archived placenta samples.

View Article and Find Full Text PDF

Background: The excitotoxic molecule, domoic acid (DA), is a marine algal toxin known to induce overt hippocampal neurotoxicity. Recent experimental and epidemiological studies suggest adverse neurological effects at exposure levels near the current regulatory limit (20 ppm, ). At these levels, cognitive effects occur in the absence of acute symptoms or evidence of neuronal death.

View Article and Find Full Text PDF

Background: Insulin resistance (IR) and central obesity are common in polycystic ovary syndrome (PCOS), but pathomechanisms for IR in PCOS are not established. Circulating microRNAs (miRNAs) are non-invasive biomarkers of epigenetic regulation that may contribute to the pathogenesis of IR and central adiposity in PCOS.

Methods: We conducted a pilot study to examine associations of circulating miRNAs with IR and central adiposity among women with PCOS (n = 11) using high-throughput miRNA sequencing.

View Article and Find Full Text PDF

Background: Maternal stress before, during and after pregnancy has profound effects on the development and lifelong function of the infant's neurocognitive development. We hypothesized that the programming of the central nervous system (CNS), hypothalamic-pituitary-adrenal (HPA) axis and autonomic nervous system (ANS) induced by prenatal stress (PS) is reflected in electrophysiological and epigenetic biomarkers. In this study, we aimed to find noninvasive epigenetic biomarkers of PS in the newborn salivary DNA.

View Article and Find Full Text PDF

Background: While strong evidence supports adverse maternal and offspring consequences of air pollution, mechanisms that involve the placenta, a key part of the intrauterine environment, are largely unknown. Previous studies of air pollution and placental gene expression were small candidate gene studies that rarely considered prenatal windows of exposure or the potential role of offspring sex. We examined overall and sex-specific associations of prenatal exposure to fine particulate matter (PM) with genome-wide placental gene expression.

View Article and Find Full Text PDF

We analyzed the effects of aging on protein abundance and acetylation, as well as the ability of the mitochondrial-targeted drugs elamipretide (SS-31) and nicotinamide mononucleotide (NMN) to reverse aging-associated changes in mouse hearts. Both drugs had a modest effect on restoring the abundance and acetylation of proteins that are altered with age, while also inducing additional changes. Age-related increases in protein acetylation were predominantly in mitochondrial pathways such as mitochondrial dysfunction, oxidative phosphorylation, and TCA cycle signaling.

View Article and Find Full Text PDF

Background: The kidneys efficiently filter waste products while retaining serum proteins in the circulation. However, numerous diseases compromise this barrier function, resulting in spillage of serum proteins into the urine (proteinuria). Some studies of glomerular filtration suggest that tubules may be physiologically exposed to nephrotic-range protein levels.

View Article and Find Full Text PDF