Biology subjects

Labadorf, A.

Publications and source records attributed to Labadorf, A..

5 recordsLinked to original sources

bioRxiv2026

Proteomic Analysis of Human Chronic Traumatic Encephalopathy Brain Implicates Proteasome and Ribosome Dysfunction in Disease Progression

Chronic traumatic encephalopathy (CTE) is a progressive neurodegenerative disease associated with repeated head injuries (RHI) commonly experienced by contact sport athletes, military personnel, and domestic abuse victims. Despite growing recognition of CTE, the molecular mechanisms underlying disease progression remain poorly understood. This study aims to identify proteomic alterations associated with CTE pathology and clinical features to elucidate key biological pathways involved in disease pathogenesis. SomaScan 7k high-throughput proteomics was performed on 204 dorsolateral prefrontal cortex samples from the Boston University CTE Center Brain Bank. We identified differentially expressed proteins associated with CTE, hyperphosphorylated tau (ptau) pathology, duration of contact sports play, dementia status, and Cognitive Difficulty Scale (CDS) scores. Gene set enrichment analysis revealed that proteasome subunit proteins and related pathways were strongly associated with CTE progression and correlated with years of contact sports play. Reduction in ribosomal proteins and pathways was closely associated with ptau burden. Additionally, multiple models demonstrated significant alterations in MAPK-related cell signaling pathways. These findings advance our understanding of CTE progression and identify mechanisms correlated with key pathological features of the disease. Validation of these results could inform the development of diagnostics and treatments for CTE.

molecular biology↗

bioRxiv2022

RNA-sequencing of human post-mortem hypothalamus and nucleus accumbens identifies expression profiles associated with obesity.

Obesity, the accumulation of body fat to excess, may cause serious negative health effects, including increased risk of heart disease, type 2 diabetes, stroke and certain cancers. The biology of obesity is complex and not well understood, involving both environmental and genetic factors and affecting metabolic and endocrine mechanisms in tissues of the gut, adipose, and brain. Previous RNA sequencing studies have identified transcripts associated with obesity and body mass index in blood and fat, often using animal models, but RNA sequencing studies in human brain tissue related to obesity have not been previously undertaken. We conducted both large and small RNA sequencing of hypothalamus (207 samples) and nucleus accumbens (276 samples) from individuals defined as consistently obese (124 samples), consistently normal weight as controls (148 samples) or selected without respect to BMI and falling within neither case nor control definition (211 samples), based on longitudinal BMI measures. The samples were provided by three cohort studies with brain donation programs; the Framingham Heart Study (FHS), the Religious Orders Study (ROS) and the Rush Memory and Aging Project (MAP). For each brain region and large/small RNA sequencing set, differential expression of obesity, BMI, brain region and sex was performed. Analyses were done transcriptome-wide as well as with a priori defined sets of obesity or BMI-associated mRNAs and microRNAs (miRNAs). There are sixteen mRNAs and five microRNAs that are differentially expressed (adjusted p < 0.05) by obesity or BMI in these tissues, several of which were validated with qPCR data. The results include many that are BMI-associated, such as APOBR and CES1, as well as many associated with the immune system and some with addiction, such as the gene sets "cytokine signaling in immune system" and "opioid signaling". In spite of the relatively large number of samples, our study was likely under-powered to detect other transcripts or miRNA with relevant but smaller effects.

genomics↗

bioRxiv2020

The CoREST Repressor Complex Mediates Phenotype Switching and Therapy Resistance in Melanoma

Virtually all patients with BRAF-mutant melanoma develop resistance to MAPK inhibitors largely through non-mutational events1,2. Although the epigenetic landscape has been shown to be altered in therapy-resistant melanomas and other cancers3,4, a specific targetable epigenetic mechanism regulating treatment resistance has not been validated to date. Here we evaluate the CoREST repressor complex and the novel inhibitor, corin5, within the context of melanoma phenotype plasticity and therapeutic resistance in order to define epigenetic mechanisms underlying these processes. We find that CoREST is a critical mediator of the major distinct melanoma phenotypes and that corin treatment of melanoma cells leads to phenotype reprogramming. We further demonstrate that treatment of BRAF inhibitor (BRAFi)-resistant melanomas with corin leads to resensitization of tumor cells to BRAFi. Among the transcriptional targets of CoREST in melanoma are the dual-specificity phosphatases (DUSPs). DUSP1 is shown to be consistently downregulated in BRAFi-resistant melanomas which can be reversed by corin treatment, thereby leading to downstream inhibition of p38 MAPK activity and resensitization of resistant cells to targeted BRAFi therapies. These findings identify the CoREST repressor complex as a central mediator of melanoma phenotype plasticity and resistance to targeted therapy and suggest that CoREST inhibitors may prove beneficial to patients with BRAF-mutant melanomas who have acquired BRAFi-resistance.

cancer biology↗

bioRxiv2019

The Caudate Nucleus Undergoes Dramatic and Unique Transcriptional Changes in Human Prodromal Huntington’s Disease Brain

The mechanisms underlying degeneration of the specific neurons in the striatum of Huntingons Disease (HD) brain are currently unknown. The striatum is massively degenerated in late stage HD, making examination of post-mortem brain tissue from symptomatic individuals problematic. Striatal tissue is largely intact in the brains of asymptomatic HD positive (HD+) gene carriers, but these samples are exceedingly rare. In this study, caudate nucleus (CAU) tissue from two asymptomatic HD+ individuals was subjected to high throughput mRNA sequencing (mRNA-Seq) for comparison with similar datasets from symptomatic HD individuals and healthy controls. The overall transcriptional response in HD+ CAU shares much of the same response observed in HD Brodmann Area 9 (BA9) samples, an area that is relatively spared from significant degeneration. A set of differentially expressed (DE) genes predominantly related to the heat shock response are found in common between brain regions, and show much higher induction in HD+ CAU than HD BA9. The most highly perturbed pathways show near complete agreement when comparing diseased tissue with control, and a random forest classifier predicted that the two HD+ CAU samples strongly resemble HD BA9 and not control BA9. Nonetheless, when genes were prioritized by their specificity to HD+ CAU, a large number of pathways spanning many biological processes emerged. Further comparison of HD+ BA9 with HD BA9 identified genes that may be early responders to disease, and have altered expression in symptomatic individuals. This study presents the first and largest examination of asymptomatic brain gene expression to date, and suggests many new avenues of investigation into the mechanisms underlying neurodegeneration in HD.

genomics↗

bioRxiv2017

Comparative Huntington And Parkinson Disease mRNA Analysis Reveals Common Inflammatory Processes

Huntingtons and Parkinsons Diseases (HD and PD) are neurodegenerative disorders that share some pathological features but are disparate in others. For example, while both diseases are marked by aberrant protein aggregation in the brain, the specific proteins that aggregate and types of neurons affected differ. A better understanding of the molecular similarities and differences between these two diseases may lead to a more complete mechanistic picture of both the individual diseases and the neurodegenerative process in general. We sought to characterize the common transcriptional signature of HD and PD as well as genes uniquely implicated in each of these diseases using mRNA-Seq data from post mortem human brains in comparison to neuropathologically normal controls. The enriched biological pathways implicated by HD differentially expressed genes show remarkable consistency with those for PD differentially expressed genes and implicate the common biological processes of neuroinflammation, apoptosis, transcriptional dysregulation, and neuron-associated functions. Comparison of the differentially expressed (DE) genes highlights a set of consistently altered genes that span both diseases. In particular, processes involving nuclear factor kappa-light-chain-enhancer of activated B cells (NFkB) and transcription factor cAMP response element-binding protein (CREB) are the most prominent among the genes common to HD and PD. When the combined HD and PD data are compared to controls, relatively few additional biological processes emerge as significantly enriched suggesting that most pathways are independently seen within each disorder. Despite showing comparable numbers of DE genes, DE genes unique to HD are enriched in far more coherent biological processes than the DE genes unique to PD, suggesting that PD may represent a more heterogeneous disorder.

genomics↗