PROJECT SUMMARY/ABSTRACT (30 lines of text):
This K01 proposal is from Dr. Xiaojun Tan, Research Assistant Professor in the Aging Institute at the University
of Pittsburgh School of Medicine. Dr. Tan has extensive and diverse experience with in vitro studies related to
aging including cellular stress response, autophagy, lipid signaling, and innate immunity. Dr. Tan is pursuing a
career in aging research with a goal of establishing his own lab in three years studying core principles in aging
and neurodegeneration and developing novel translational therapeutics for age-related diseases, especially
neurodegenerative diseases. A K01 Award would be critical in providing Dr. Tan with protected time for additional
training in neurobiology and in vivo studies as well as career development to ensure his transitioning into an
independent aging investigator. The proposed research project is the study of a new lysosomal quality control
pathway in neuronal tau spreading and Alzheimer’s disease (AD). Specifically, Dr. Tan discovered that lysosomal
membrane permeabilization/damage (LMP) triggers robust lipid signaling on lysosomes which in turn mediates
rapid lysosomal repair. This pathway is dependent on LMP-stimulated lysosomal recruitment of the lipid kinase
PI4K2A (phosphatidylinositol 4-kinase type 2 alpha). Rapid lysosomal repair is expected to effectively suppress
tau fibril spreading in AD, as endocytosed tau fibrils are known to invade the cytosol of recipient cells by triggering
LMP. Thus, the hypothesis is that PI4K2A senses LMP induced by tau fibrils and activates rapid lysosomal
repair to prevent tau fibril spreading by blocking its lysosomal escape. Two aims will be pursued: (1) investigate
the mechanism by which PI4K2A senses neuronal lysosomal damage by internalized tau fibrils; (2) determine
the in vitro and in vivo impact of the PI4K2A pathway on tau spreading and tauopathy using Pi4k2a brain-specific
knockout mice. To accomplish the proposed research, Dr. Tan will carry out a comprehensive training plan
including formal course work, seminars, conferences and hands-on training as well as the mentorship from three
leading experts in aging research with Dr. Toren Finkel as the primary mentor and Dr. Stacey Rizzo and Dr. Ana
Maria Cuervo as co-mentors. Dr. Finkel has significant experience in developing new mouse models. Dr. Rizzo
is an expert of Alzheimer’s disease and translational research. Dr. Cuervo is an international leader studying
cellular quality control in aging and neurodegeneration who will also provide advice on Dr. Tan’s career
development and grant applications. The proposed research training will focus on three categories (1)
knowledge in neuroscience and Alzheimer’s disease; (2) tissue isolation and primary cultures; (3) mouse model
generation and phenotyping. The career development goals in the award period include (1) expanding Dr.
Tan’s collaboration network, (2) building leadership and lab management skills, (3) additional learning about
mentoring and teaching, and (4) improving grant writing and presentation skills. Successful completion of the
proposed research and training plan will provide the knowledge and experience necessary to progress toward
Dr. Tan’s career goal of becoming an independent aging investigator studying neuronal aging and AD.