Posts classified under: F

William Flavin, M.D., Ph.D.

Associate Member

Clinical Instructor and Postdoctoral Scholar
Department of Neurology
David Geffen School of Medicine
University of California, Los Angeles


Personal Statement
I am a physician-scientist with the longstanding goal of understanding cellular and molecular mechanisms of neurodegeneration, especially in Alzheimer’s disease and related dementias (ADRD) and Parkinson’s disease (PD), where these discoveries will lead to innovative diagnostics and therapeutics. As a former Division I collegiate football student athlete, I am particularly interested in advancing a mechanistic understanding of traumatic brain injury (TBI)-related neurodegeneration such as in chronic traumatic encephalopathy (CTE). During my PhD training with Dr. Edward Campbell, I explored the mechanisms mediating prion-like transcellular propagation of protein aggregates. By applying methods used to model host-pathogen interactions, my work illuminated a novel mechanism of cellular invasion, through endocytic vesicle rupture, by which aggregates of alpha-synuclein, tau, and polyglutamine-expanded huntingtin gain access to the cytosol following uptake into a recipient cell. In parallel, I discovered that disease-causing mutations, post-translational modifications, and aggregate conformational structure modulate this uptake mechanism. This work motivated my fascination with the interactions between diverse protein aggregates and the dynamic cellular environment, and how this interaction dictates cell fate, either resilience and survival or vulnerability and disease progression. My professional goal is to become a clinical and research leader in the fields of TBI and neurodegeneration, working as an academic neurologist leading an NIH-funded research laboratory focused on elucidating the cellular machinery governing neurodegenerative disease progression and discovering new mechanisms to enhance treatment strategies.

In pursuit of this vision, I completed my residency in neurology at UCLA and am currently engaged in a clinical instructorship in sports neurology and traumatic brain injury. Supported by the NINDS-funded R25/UE5 program, I am now completing my post-doctoral research training with Dr. Chao Peng at UCLA who has pioneered methods to study the conformational diversity and cellular transmission of pathological proteins derived from post-mortem human brain. Bringing my interest in mechanisms of aggregate uptake through the endolysosomal system to the expertise of the lab in modeling cell environmental influences on disease progression, I characterized the influence of aging-related genetic changes on the cytosolic growth of tau aggregates. Furthermore, I engineered a novel inducible cell biosensor system for studying human AD brainderived tau aggregate amplification and degradation, enabling high-throughput analysis of chemical or genetic modifiers of aggregation dynamics. This project constitutes the first step toward a broader goal which is characterizing disease-specific interactions between diverse protein aggregates and the cellular environment to identify mechanisms of resilience to degeneration. In the current K08 proposal, I will investigate the functional differences between structurally distinct tau aggregates isolated from AD and CTE post-mortem brain, focusing on aggregation dynamics, uptake into the cytoplasm, and cell-to-cell transmission. I will extend and validate these findings by investigating cellular mechanisms of resilience to pathology, both in the end lysosomal damage response as well as in changes associated with aging. This work will deliver a method for studying the aggregation dynamics of CTE tau where no such models currently exist, and will allow mechanistic insight into ADRD disease progression.

Gordon Fain, Ph.D.

Biography

A vertebrate photoreceptor uses a G-protein receptor (rhodopsin) and a G-protein cascade to produce the electrical response that signals a change in light intensity. Powerful new techniques have made it possible to understand the working of this cascade in extraordinary detail. The reason for this is that practically every protein involved in the cascade in a photoreceptor, from the pigment molecule rhodopsin to the G-protein and channels, but including also a large number of control proteins, are expressed only in the photoreceptors and nowhere else in the body. This makes it possible with genetic techniques to create mice in which these proteins have been knocked out, over or under expressed, or replaced with proteins of modified structure. We use electrical recording to study the effects of such genetic alterations on the light responses of mouse rods and cones, in order to understand the role of these proteins in the visual cascade. We are especially interested in modulatory enzymes and their function in light and dark adaptation. We also have a long-standing interest in mechanisms of photoreceptor degeneration in genetically inherited disease.

Publications

A selected list of publications:

Fain Gordon, Sampath Alapakkam P   Rod and cone interactions in the retina F1000Research, 2018; 7: .
Morshedian Ala, Woodruff Michael L, Fain Gordon L   Role of recoverin in rod photoreceptor light adaptation The Journal of physiology, 2018; 596(8): 1513-1526.
Morshedian Ala, Toomey Matthew B, Pollock Gabriel E, Frederiksen Rikard, Enright Jennifer M, McCormick Stephen D, Cornwall M Carter, Fain Gordon L, Corbo Joseph C   Cambrian origin of the CYP27C1-mediated vitamin A Royal Society open science, 2017; 4(7): 170362.
Morshedian Ala, Fain Gordon L   Light adaptation and the evolution of vertebrate photoreceptors The Journal of physiology, 2017; 595(14): 4947-4960.
Kaylor Joanna J, Xu Tongzhou, Ingram Norianne T, Tsan Avian, Hakobyan Hayk, Fain Gordon L, Travis Gabriel H   Blue light regenerates functional visual pigments in mammals through a retinyl-phospholipid intermediate Nature communications, 2017; 8(1): 16.
Morshedian Ala, Fain Gordon L   The evolution of rod photoreceptors Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 2017; 372(1717): 16.
Ingram Norianne T, Sampath Alapakkam P, Fain Gordon L   Why are rods more sensitive than cones? The Journal of physiology, 2016; 594(19): 5415-26.
Reingruber Jürgen, Holcman David, Fain Gordon L   How rods respond to single photons: Key adaptations of a G-protein cascade that enable vision at the physical limit of perception BioEssays : news and reviews in molecular, cellular and developmental biology, 2015; 37(11): 1243-52.
Morshedian Ala, Fain Gordon L   Single-photon sensitivity of lamprey rods with cone-like outer segments Current biology : CB, 2015; 25(4): 484-7.
Reingruber Jürgen, Pahlberg Johan, Woodruff Michael L, Sampath Alapakkam P, Fain Gordon L, Holcman David   Detection of single photons by toad and mouse rods Proceedings of the National Academy of Sciences of the United States of America, 2013; 110(48): 19378-83.
Chen Ching-Kang, Woodruff Michael L, Chen Frank S, Chen Yenlin, Cilluffo Marianne C, Tranchina Daniel, Fain Gordon L   Modulation of mouse rod response decay by rhodopsin kinase and recoverin The Journal of neuroscience : the official journal of the Society for Neuroscience, 2012; 32(45): 15998-6006.
Chen Jeannie, Woodruff Michael L, Wang Tian, Concepcion Francis A, Tranchina Daniel, Fain Gordon L   Channel modulation and the mechanism of light adaptation in mouse rods The Journal of neuroscience : the official journal of the Society for Neuroscience, 2010; 30(48): 16232-40.
Fain Gordon L, Hardie Roger, Laughlin Simon B   Phototransduction and the evolution of photoreceptors Current biology : CB, 2010; 20(3): R114-24.
Okawa Haruhisa, Sampath Alapakkam P, Laughlin Simon B, Fain Gordon L   ATP consumption by mammalian rod photoreceptors in darkness and in light Current biology : CB, 2008; 18(24): 1917-21.
Dizhoor Alexander M, Woodruff Michael L, Olshevskaya Elena V, Cilluffo Marianne C, Cornwall M Carter, Sieving Paul A, Fain Gordon L   Night blindness and the mechanism of constitutive signaling of mutant G90D rhodopsin The Journal of neuroscience : the official journal of the Society for Neuroscience, 2008; 28(45): 11662-72.
Fain GL   Why photoreceptors die (and why they don’t), BioEssays, 2006; 28: 344-354.
1 2 3 5