2015 Funded Pilot Projects

The microenvironment after spinal cord injury (SCI) plays a critical role in determining the potential for transplanted human neural stem cells (hNSC) to mediate functional recovery. Evidence suggests a multiphasic cellular response after SCI: an early polymorphonuclear leukocyte (PMN or neutrophil) invasion (1 day post-injury), and a biphasic macrophage/microglia response (7 and 60 days post-injury) in rodent models. PMNs, the first immune cells to infiltrate the injured spinal cord, reside at the epicenter and secrete factors—complement proteins, cytokines, proteases, and reactive oxygen species—that impact cell death, migration, and differentiation. We hypothesize that PMNs modulate the migration and lineage selection of transplanted hNSCs. Unlike subacute (9 dpi) and chronic (30 dpi) transplantation, acute (0 dpi) transplantation results in hNSC migration toward the injury and predominant astrocytic differentiation (>90%), a pattern associated with failure to achieve functional recovery. Conditioned media (CM) from PMNs (but not macrophages) promotes hNSC migration and astrocytic fate in vitro. This project tests whether PMN depletion using a Ly6G antibody can prevent hNSC astrogliosis and restore motor/sensory function after SCI. These findings will advance understanding of inflammatory microenvironment control and timing of transplantation, with potential insights into endogenous neural stem cell behavior post-injury.

This project aims to develop a pharmacological intervention for chemotherapy-related cognitive impairment (CRCI), a prevalent and disabling side effect of cancer treatment that diminishes survivors’ quality of life and limits treatment efficacy. Focused on cisplatin—a common chemotherapeutic for ovarian cancer—this research investigates N-acetylcysteine, a glutathione precursor and antioxidant capable of crossing the blood-brain barrier. Preclinical data suggest that cisplatin causes synaptic and dendritic spine loss due to mitochondrial damage and oxidative stress, leading to cognitive deficits. N-acetylcysteine has demonstrated protective effects against such damage in vitro and in prior clinical settings (e.g., ototoxicity, neuropathy prevention). Two aims guide this study: Aim 1: Determine if in vivo N-acetylcysteine prevents synaptic loss and neuron death in CA1 and CA3 hippocampal regions following cisplatin treatment. Aim 2: Assess whether N-acetylcysteine administration prevents learning and memory deficits in vivo following cisplatin treatment. The ultimate goal is to generate data supporting an NIH R01 resubmission proposing a clinical trial for CRCI prevention and treatment using this repurposed drug.

Each year, over 800,000 people in the U.S. suffer strokes, many resulting in long-term disability. Stem cell transplantation is a promising treatment, particularly when combined with scaffolds that support cell survival and integration into brain tissue. Injectable scaffolds, designed to polymerize in vivo, offer an ideal method for CNS applications by filling tissue cavities without additional damage. The project focuses on optimizing scaffold materials—particularly fibrin and hyaluronic acid—to match CNS mechanical properties and support neural stem/progenitor cell (NSPC) fate via mechanotransduction. Preliminary 2D culture studies show that substrate stiffness and stretch affect NSPC differentiation, likely through integrin-mediated pathways. In vivo studies will test various scaffold combinations in a stroke model, emphasizing degradation rate and tissue integration, aiming to improve functional recovery and stem cell-mediated repair.

This proposal explores a novel therapeutic strategy: combining ABT-199 (venetoclax), a BCL-2 inhibitor, with statins (HMG-CoA-reductase inhibitors) in aggressive lymphomas. Statins, widely used to manage cholesterol, also show anti-cancer properties and synergize with ABT-199 in lymphoma cell lines and murine models. BH3 profiling reveals simvastatin enhances mitochondrial priming, augmenting ABT-199-induced apoptosis. Mechanistically, statins appear to block protein prenylation downstream of mevalonate synthesis, priming lymphoma cells for cell death. Two main aims: Aim 1: Test ABT-199 and simvastatin in vivo in BCL-2/MYC-driven murine lymphoma models, assessing tumor growth, survival, and pharmacodynamics. Aim 2: Evaluate selectivity by comparing drug effects on malignant cells versus normal lymphocytes in mice and healthy human donor cells. These studies aim to generate proof-of-concept data supporting future clinical trials of this drug combination in lymphoma treatment.

Cochlear implants have revolutionized treatment for profound deafness, but users still face limitations—poor pitch perception, difficulty in noisy environments, and inability to localize sound. These issues stem from the implant’s position, separated by bone from the auditory nerve. This project investigates an alternative: chronic intraneural auditory nerve implantation using penetrating electrode arrays in cats. Short-term experiments show this approach surpasses cochlear implants in signal transmission. The study involves: 1) Short-term baseline testing of a commercially-available implantable array, and 2) Chronic (3-month) implantation to assess long-term signal stability and anatomical outcomes. These animal studies are a crucial precursor to developing a next-generation auditory prosthesis for humans, addressing limitations of current cochlear technology and aiming to restore richer auditory experiences.

The tumor suppressor p53 is an important cell cycle regulating transcription factor and is the most mutated gene in human cancers. Most of these p53 cancer mutations are single amino acid substitution in the DNA-binding domain (DBD) that cause a destabilization of the p53 DBD. The most common of these p53 DBD missense mutations is the p53R175H mutation. A pharmaceutical which can restore endogenous p53 function to p53R175H or any of these single amino acid mutations could have an enormous impact on our treatment of cancer. Using an R175H protein-based chemical library screen and a cancer cell cultures validation, we have discovered the copper thiosemicarbazone, NSC635448, which is able to stabilize the R175H DBD and induce R175H-dependent cell cycle arrest in osteosarcoma cells. We are looking to gain important preliminary results on the restoration of mutant p53 function with NSC635448 in order to position ourselves to secure extramural funding. Using several biophysical techniques we plan to: (1) Use Biacore, electrospray ionization mass spectroscopy, and X-ray crystallography to gain a more definitive understanding of the binding of copper thiosemicarbazones to mutant p53 DBD (2) Validate that copper thiosemicarbazones actually restore function to mutant p53 within cancer cells using live-cell spatiotemporal tracking of mutant p53 activity and (3) Evaluate copper thiosemicarbazone toxicity in non-cancerous cells containing wild-type p53. The overarching goal of this project is to understand in detail how copper thiosemicarbazones restore function to mutant p53 and gain preclinical evidence for copper thiosemicarbazones use as a mutant p53-targeting therapeutic.

Recent genome wide association studies (GWAS) have identified several single nucleotide polymorphisms (SNPs) that increase one’s risk of developing sporadic, late-onset Alzheimer’s disease (AD), the most prevalent cause of dementia. Individually, each inherited SNP modifies risk modestly and suggests that sporadic AD is a complex disease involving both genetic and environmental risk factors. Many of these SNPs are linked to genes common to biological pathways including endocytosis and immune function. One of the major neuropathological hallmarks of AD, β-amyloid, accumulates due to over-production of the toxic protein, the inability to clear the peptide sufficiently, acquisition of prion-like propagation, or a combination. The failure of clinical drug trials to date is likely due in part to the complex etiology of AD that may involve several biological processes that are unlikely to be targeted by a single compound. Furthermore, this complex etiology impacts the development of a diagnostic AD biomarker. The aim of this proposal is to identify AD risk endophenotypes that are diagnostic of increased number of polymorphisms within either the endocytic or the inflammatory pathway. Understanding the mechanism by which these SNPs contribute to AD risk will identify novel therapeutic targets. Our data suggest that the accumulation of SNPs for the endocytic pathway leads to increased hippocampal plaque burden. In preliminary studies, endocytic-pathway dysregulation results in increased Aβ production whereas immune function genes may determine the effectiveness of microglia to properly clear amyloid from the brain. The translational significance of these studies is that genetics may predict peripheral endophenotypes that can in turn be used to develop personalized therapies targeting specific biological mechanisms.

Retinopathy of prematurity (ROP) is a leading cause of childhood blindness that severely affects quality of life. It is associated with abnormal retinal vascular development and occurs only in premature infants. ROP is characterized by pathological angiogenesis, or neovascularization (NV), of the retina. The few treatment options that are currently available are associated with frequent unfavorable outcomes. Stem cell therapy, through its proven potential in tissue preservation/regeneration, provides an attractive strategy for treating ROP and thereby restoring vision. The proposed pilot study is designed to test the hypothesis that intravitreal injection of retinal progenitor cells (RPC) will result in improved visual outcomes in an established animal model of ROP. The oxygen induced retinopathy (OIR) rat model closely resembles the pathology present in human preterm infants with severe ROP. The newborn pups will be placed into a controlled oxygen chamber that changes oxygen level from 50% to 10% every 24 hours for 14 days. 2 µl of rat RPCs or sham (vehicle only) will be injected into the vitreous cavity at the end of this induction period. Contralateral eyes will serve as untreated controls; at least 5 animals of each group will be evaluated in order to generate statistically meaningful data. Behavioral testing and histological evaluation will be performed on age-matched control animals (room air adapted rats) for comparison to cell/sham-injected animals. Functional analysis of retinal preservation, including optomotor response and ERG, will be performed at day 18. Histopathology and morphometric analysis will be performed to confirm retinal preservation. Given the PI’s extensive preclinical work experience, including successful prior IND submission, performance of this pilot study should be relatively straightforward. The data generated by this study would provide Proof of Concept in support of a future large translational research grant application, e.g., CIRM early translational (ET) or disease team (DT) grant.