The meninges are a multi-layered membranous structure that encase the central nervous system and serve as a crucial interface between the brain and the skull. During embryogenesis, these layers emerge from a single layer of mesenchyme called the primary meninx. While the general function of adult meninges has been investigated, the developmental basis for establishing the primary meninx remains poorly understood. We sought to resolve the developmental pathways that govern the formation of this tissue. Using an established Gal4/UAS transgenic line for the meningeal fibroblast marker, foxc1b, in zebrafish, we imaged meninges formation across development. We observed foxc1b+ fibroblasts as early as 1 day post fertilization (dpf) and a complete primary meninx layer by 3 dpf. To determine the developmental pathways responsible for properly establishing the primary meninx, we performed a systemic screen targeting key developmental pathways. Using drug inhibitors, we treated embryos at 1 dpf and imaged fish at 3 or 6 dpf. Of 8 inhibitors tested, we identified two pathways necessary for proper meninx formation: the BMP and Wnt signaling pathways. We found that proper activation of both pathways was required for the formation of a continuous primary meninx, suggesting an early role for these pathways to support meningeal fibroblast differentiation. These experiments uncover novel pathways that drive primary meninx formation and lay a critical foundation for studies that examine the molecular basis of meningeal development.

The adult mammalian heart cannot regenerate following myocardial infarction; however, the neonatal heart possesses remarkable regenerative capacity. Loss of this capacity co-occurs with cardiac maturation, partly driven by the transition from low to oxygen levels needed to meet the metabolic demand of the postnatal heart. Supraphysiological oxygen accelerates loss of regenerative capacity, suggesting oxygen is an essential regulator of cardiomyocyte maturation. Peroxisomes are oxygen-dependent subcellular organelles that mediate the synthesis of ether lipids required for electrically excitable cells such as neurons. However, the roles of peroxisomes and ether lipids in cardiac maturation are unknown. We hypothesize that peroxisomal ether-lipid synthesis is required for cardiomyocyte maturation. To study hypoxia's effects on peroxisomal function and gene transcription, we ran immunoblots and RT-qPCR on normoxic and hypoxic rat myocytes in vivo and in vitro, targeting peroxisomal proteins and histones H1 and H3.3. Hypoxia alters chromatin in neonatal ventricular myocytes by accumulating replication-independent histones H1 and H3.3, suggesting transcriptional reprogramming despite limited cell division as the heart matures. Concurrently, hypoxia alters peroxisomal function, as indicated by decreased PMP70, suggesting reduced membrane mass, as well as AGPS accumulation, suggesting increased peroxisome activity.

Acute myeloid leukemias (AMLs) with inv(3)(q21q26)/t(3;3)(q21;q26) chromosomal rearrangements are associated with poor outcomes and resistance to standard therapies. These alterations upregulate the MECOM oncogene while silencing GATA2, driving leukemogenesis. To explore immunotherapeutic opportunities, this study investigates how overexpression of MECOM, MLLT3, MYCT1, and EGFRvIII alters MHC-I antigen presentation in leukemia cells. Using custom engineered vectors with oncogenic and tumor-suppressive factors in inv(3)/t(3;3) leukemias cloned into a vector backbone, we engineered overexpression of these genes in leukemia lines and applied two complementary immunopeptidomic workflows—ARTEMIS and a novel mild acid elution protocol (MAE)—to identify differentially presented peptides. Antigenic peptides confirmed to be from our genes of interest were identified, with gene induction increasing peptide diversity and abundance. These shifts suggest that oncogenic and tumor-suppressive transcriptional regulators modulate the antigenic landscape and may expose novel targets for precision immunotherapies in high-risk AML.

Systemic sclerosis is an incurable complex autoimmune disorder involving multiple organ systems and characterized by fibrosis of the skin, fibrosis of internal organs, and vasculopathy. The process of skin fibrosis, which is further analyzed in this study, involves the accumulation of connective tissue, expansion of the dermis, along with the subsequent destruction of hair follicles, skin appendages, and sweat glands. Previous studies have shown that myofibroblasts in the skin originate from adipocytes in a process known as adipocyte to myofibroblast transition (AMT), marking a potential key initiation event of fibrosis. This study aims to provide insight into the role Vitamin C plays during AMT. Human Adipose-Derived Stem Cells (hADSC) were first cultured in adipogenic differentiation media to mimic adipocytes in non-fibrotic tissue. Cells were photographed and RNA was collected and analyzed to confirm adipocyte differentiation. Differentiated adipocyte cohorts will be treated with myofibroblast differentiation media containing varying concentrations of Vitamin C, to study changes in transcription, protein expression, and morphology throughout the AMT. By revealing the unknown role Vitamin C plays in fibrosis pathogenesis at the molecular and cellular level, this research can potentially aid in developing new therapeutic approaches for systemic sclerosis patients.

High levels of saturated fat in the Western diet increases the risk for chronic low-grade inflammation, contributing to the risk of metabolic disorders such as Type 2 Diabetes and cardiovascular disease. Inflammation following a fatty meal results from the release into the circulation of endotoxin (also known as lipopolysaccharide, LPS) from bacteria residing in the intestinal tract. The circulating LPS induces an inflammatory response that lasts several hours, and which may contribute to chronic inflammation. Males experience higher levels of postprandial LPS compared to females, but the mechanisms for this sex difference are unknown. We investigated the role of gonadal sex (ovaries or testes) and chromosomal sex (XX or XY chromosomes) in postprandial inflammation using the Four Core Genotypes mouse model. We found that postprandial LPS levels are enhanced in mice carrying XY chromosomes compared to those with XX chromosomes, regardless of the presence of ovaries or testes. This raised the question of whether XX chromosomes protect, or the Y chromosome promotes, elevated LPS levels. Using the XY* mouse model (XX, XY, XXY and XO), we determined that the Y chromosome promotes elevated LPS levels, as XY and XXY have elevated endotoxemia compared to XX and XO mice. We will now investigate specific Y chromosome genes, alongside inflammatory genes, as candidates contributing to this effect. This will involve both in vitro and in vivo models, as well as analysis of the inflammatory landscape in metabolic tissues from these models.