Radiation Induces Metabolic Dysregulation in Pulmonary Fibroblasts

Rationale: Exposure of the lung to ionizing radiation, such as during radiotherapy, can result in pulmonary fibrosis (PF), which has few treatment options. PF is characterized by an accumulation of extracellular matrix proteins that form scar tissue, resulting in dyspnea, disruption of gas exchange, and even death. We and others have shown that metabolic reprogramming is a hallmark of idiopathic pulmonary fibrosis (IPF). IPF lung tissue, and lung fibroblasts treated with TGF-β, exhibit increased aerobic glycolysis with increased expression of lactate dehydrogenase A (LDHA) and excess production of lactate, leading to reduced extracellular pH that activates latent TGF-β. Here, we hypothesized that ionizing radiation would cause aerobic glycolytic metabolic dysregulation in primary human lung fibroblasts. Results: Primary non-fibrotic HLFs exposed to irradiation exhibited significant upregulation of Pyruvate Dehydrogenase Kinase (PDK1 (0.5 – 3-fold, p\u3c0.05) and LDHA (1.4-fold, p\u3c0.05). Cell viability was unaffected by increased radiation dose. Conclusions: Radiation increased fibroblast expression of genes involved in fibrotic phenotypes (αSMA) and aerobic glycolysis (PDK1 and LDHA), in a similar pattern to that seen in IPF fibroblasts. The metabolic changes are closely associated with creating a profibrotic extracellular environment in IPF by promoting an acidic environment. Our evidence suggests this phenomenon can be driven by radiation in lung fibroblasts and affirm that glycolytic reprogramming may also be a hallmark of radiation-induced fibrosis. Further understanding of the common mechanisms that create this metabolic shift could provide novel therapeutics for fibrosis treatment.https://scholarscompass.vcu.edu/gradposters/1158/thumbnail.jp

Variants Affecting Exon Skipping Contribute to Complex Traits

DNA variants that affect alternative splicing and the relative quantities of different gene transcripts have been shown to be risk alleles for some Mendelian diseases. However, for complex traits characterized by a low odds ratio for any single contributing variant, very few studies have investigated the contribution of splicing variants. The overarching goal of this study is to discover and characterize the role that variants affecting alternative splicing may play in the genetic etiology of complex traits, which include a significant number of the common human diseases. Specifically, we hypothesize that single nucleotide polymorphisms (SNPs) in splicing regulatory elements can be characterized in silico to identify variants affecting splicing, and that these variants may contribute to the etiology of complex diseases as well as the inter-individual variability in the ratios of alternative transcripts. We leverage high-throughput expression profiling to 1) experimentally validate our in silico predictions of skipped exons and 2) characterize the molecular role of intronic genetic variations in alternative splicing events in the context of complex human traits and diseases. We propose that intronic SNPs play a role as genetic regulators within splicing regulatory elements and show that their associated exon skipping events can affect protein domains and structure. We find that SNPs we would predict to affect exon skipping are enriched among the set of SNPs reported to be associated with complex human traits.</p

Direct Molecular Detection and Genotyping of Borrelia burgdorferi from Whole Blood of Patients with Early Lyme Disease

Direct molecular tests in blood for early Lyme disease can be insensitive due to low amount of circulating Borrelia burgdorferi DNA. To address this challenge, we have developed a sensitive strategy to both detect and genotype B. burgdorferi directly from whole blood collected during the initial patient visit. This strategy improved sensitivity by employing 1.25 mL of whole blood, a novel pre-enrichment of the entire specimen extract for Borrelia DNA prior to a multi-locus PCR and electrospray ionization mass spectrometry detection assay. We evaluated the assay on blood collected at the initial presentation from 21 endemic area patients who had both physician-diagnosed erythema migrans (EM) and positive two-tiered serology either at the initial visit or at a follow-up visit after three weeks of antibiotic therapy. Results of this DNA analysis showed detection of B. burgdorferi in 13 of 21 patients (62%). In most cases the new assay also provided the B. burgdorferi genotype. The combined results of our direct detection assay with initial physician visit serology resulted in the detection of early Lyme disease in 19 of 21 (90%) of patients at the initial visit. In 5 of 21 cases we demonstrate the ability to detect B. burgdorferi in early Lyme disease directly from whole blood specimens prior to seroconversion

Opuntia in México: Identifying Priority Areas for Conserving Biodiversity in a Multi-Use Landscape

BACKGROUND: México is one of the world's centers of species diversity (richness) for Opuntia cacti. Yet, in spite of their economic and ecological importance, Opuntia species remain poorly studied and protected in México. Many of the species are sparsely but widely distributed across the landscape and are subject to a variety of human uses, so devising implementable conservation plans for them presents formidable difficulties. Multi-criteria analysis can be used to design a spatially coherent conservation area network while permitting sustainable human usage. METHODS AND FINDINGS: Species distribution models were created for 60 Opuntia species using MaxEnt. Targets of representation within conservation area networks were assigned at 100% for the geographically rarest species and 10% for the most common ones. Three different conservation plans were developed to represent the species within these networks using total area, shape, and connectivity as relevant criteria. Multi-criteria analysis and a metaheuristic adaptive tabu search algorithm were used to search for optimal solutions. The plans were built on the existing protected areas of México and prioritized additional areas for management for the persistence of Opuntia species. All plans required around one-third of México's total area to be prioritized for attention for Opuntia conservation, underscoring the implausibility of Opuntia conservation through traditional land reservation. Tabu search turned out to be both computationally tractable and easily implementable for search problems of this kind. CONCLUSIONS: Opuntia conservation in México require the management of large areas of land for multiple uses. The multi-criteria analyses identified priority areas and organized them in large contiguous blocks that can be effectively managed. A high level of connectivity was established among the prioritized areas resulting in the enhancement of possible modes of plant dispersal as well as only a small number of blocks that would be recommended for conservation management

A new species of Amyris (Rutaceae) from Baja California Sur, Mexico.

Field exploration and floristic research have revealed another plant species endemic to the peninsula of Baja California, Mexico. A new shrubby species (Amyris certerae)from the Sierra Guadalupe and Sierra de la Giganta, Baja California Sur, is described here. Distribution, associated vegetation, rarity, affinity to another species in the genus, and a botanical illustration are presented