Dysregulation of Nicotinamide Adenine Dinucleotide (NAD) metabolism is an underlying feature of aging and its related diseases. NAD is an essential bioenergetic molecule and age-related declines contribute to the impairment of cellular homeostasis through: mitochondrial dysfunction, genomic instability, and altered intracellular signaling. NAD de-novo synthesis and salvage pathways, and consuming enzymes like sirtuins, CD38, and poly (ADP ribose) polymerases, finely regulate NAD metabolism and cellular function. However, the cellular mechanisms driving NAD decline with age remain largely unknown. Our lab has shown that 1) senescent cells drive tissue NAD decline with age via the activation of macrophages expressing CD38, and 2) macrophages can undergo senescence. These studies uncover a link between senescent cells, NAD metabolism, and macrophage activation. The goal of this study is to characterize the NAD metabolism of senescent macrophages to better understand how global NAD levels are regulated and how they contribute to the progression of aging and macrophage effector function. We hypothesize that senescent macrophages drive NAD consumption through the dysregulation of NAD regulating pathways. Using senescent macrophages derived from mouse bone marrow, we will test this hypothesis by RT-qPCR and Western, and quantify NAD hydrolysis rates. Preliminary NADase data suggest that senescent macrophages display low grade consumption of NAD compared to naive macrophages. This research will provide insight into the regulation of NAD metabolism in senescent macrophages to assess novel therapeutic targets to regulate tissue NAD levels with age.

Superhard materials with a Vickers Hardness of >40GPa are used as cutting tools and abrasives. Diamond is the hardest known material, but its high-pressure synthesis has led to a search for alternatives. One alternative of interest is transition metal borides because of their ambient pressure synthesis. Additionally, their intrinsically high hardness can be further improved by solid solution effects and/or decreasing crystal grain size; the latter is called the Hall-Petch Effect. The Hall-Petch Effect states that as a polycrystalline material's grain size decreases, its hardness increases. However, if the grain size shrinks too much, there is an inverse Hall-Petch Effect, where the material softens due to rotational and translational movements of the grains. In this work we attempt to better understand the Hall-Petch and inverse Hall-Petch Effects by synthesizing and studying nanocrystalline tungsten diboride materials, both pure and in solid solution form. We first targeted tungsten diboride and a 6% Nb solid solution of tungsten diboride, synthesized using salt-flux techniques, to get different grain sizes. We then characterize and determine size by X-ray diffraction (XRD) peak-width analysis. The results indicate that increasing reaction temperature minimally increases grain size, but increasing reaction time gives improved crystal growth and larger grains. Therefore, in future syntheses, we will focus on longer soak times. We will then perform hardness testing on the samples, and use that to determine trends in hardness vs. grain size. The results from this study can be used as a reference for future optimizations of superhard transition metal borides.

Current clinical trials for Duchenne muscular dystrophy (DMD) use adeno-associated virus serotype 9 (AAV9) as a vector to deliver gene therapies. Immune responses against the AAV capsid mediated by the classical complement pathway have triggered serious adverse events that compromise the safety and efficacy of gene therapies. Classical complement activation requires the presence of anti-AAV IgG and AAV complexes, also known as immune complexes. However, prior work has shown cytokine induction is enhanced after double dosing with AAV in a classical complement knockout mouse model. To explain these findings, I hypothesize that immune complexes enter innate immune cells such as macrophages by antibody dependent enhancement (ADE), where Fcγ receptors act as viral co-receptors, thus inducing cytokine expression. This study aimed to determine if ADE facilitates AAV9 transduction in macrophages and if transduction can be enhanced by complement-opsonized AAV through a similar complement-receptor mediated process. Understanding how AAV is internalized and activates downstream immunity is vital to developing targeted immune suppressants to make AAV mediated gene therapies safer. THP-1 macrophages were transduced with AAV9 preincubated with intravenous immunoglobulin (IVIg) or C3b, an opsonizing complement protein. AAV9-GFP preincubated with high IVIg concentrations resulted in increased GFP expression while C3b-opsonized AAV9 did not enhance transduction. Preliminary analysis of cytokine expression by qPCR revealed THP-1 macrophages transduced with immune complexes exhibited higher levels of CCL2, CCL4, CXCL10, and STING compared to AAV alone. Future work is needed to assess iC3b-opsonized AAV9 transduction, quantify GFP expression, and further evaluate differences in cytokine production.

This study investigated the disruption of LRP1 and DLLR pathways, crucial for cellular signaling, using a stem cell model. Focus lay on the effects of this disruption on vital neuronal proteins—synaptophysin and PSD95, vital for synaptic function. These proteins have significant implications in psychiatric disorders, underlining their neural importance. The research's exploration of how knocking down LRP1 and DLLR impacts these proteins enhances our understanding of psychiatric conditions' molecular basis. By deciphering the mechanisms connecting disrupted pathways to altered synaptic protein levels, potential therapeutic pathways are illuminated. Targeting these pathways could offer innovative interventions to address protein-related synaptic dysfunction in psychiatric disorders, addressing fundamental aspects of these complex conditions.