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Neuroscience Graduate Program at UCSF

Faculty - Katerina Akassoglou, Ph.D.

Neurovascular Mechanisms of Inflammation and Tissue Repair


Research Description

Our lab studies mechanisms of neurovascular regulation of inflammation and tissue repair. Our current research focuses on identifying the molecular and cellular interface that blood proteins utilize to interact with nervous system cells and change their functions. Our ultimate goal is to target these interactions for therapeutic intervention in neurologic diseases.

Rupture of the vasculature allows the entry of blood proteins into the brain with subsequent edema formation and neuronal damage in a variety of neurologic diseases, such as stroke, multiple sclerosis (MS), Alzheimer's Disease (AD) and spinal cord injury. Our studies aim to unravel the molecular mechanisms of the CNS response to neurovascular changes with the ultimate goal to develop novel therapeutic strategies for neurologic diseases.
We integrate animal modeling, histopathology, tissue culture and biochemistry techniques, as a multifaceted experimental approach to address the biological complexity of disease and repair mechanisms. We have developed in vivo imaging tools of the mouse brain and spinal cord that enable us to monitor disease processes in real time in the living animal.

Our work showed that blood proteins are not merely markers of blood-brain barrier (BBB) disruption, but play a causative role in CNS disease by exerting both pro-inflammatory and neurodegenerative effects. Our studies identified fibrinogen as a potential novel target for therapeutic intervention in neuroinflammatory diseases and led to the design of inhibitory peptides that specifically inhibit the damaging proinflammatory effects of fibrinogen in the CNS without affecting its effects in blood coagulation. Our work also showed that removal of fibrin from the CNS via proteolytic degradation is regulated by the neurotrophin receptor p75NTR via a novel signaling pathway whereby p75NTR directly binds the phosphodieserase isoform PDE4A to compartmentalize cAMP signaling in cells. We also showed novel biological functions for p75NTR as a regulator of cell differentiation that is critical for the progression of fibrosis and tissue repair. Overall, our studies have suggested that bi-directional molecular mechanisms of communication between the blood and the brain determine the degree of damage and the regenerative potential of tissues within and outside of the nervous system.

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Current Projects

  1. Functional role of BBB disruption in inflammation and neurodegeneration
  2. Fibrinogen signal transduction in neurons and glia
  3. In vivo imaging of neurologic disease using multiphoton microscopy
  4. Site-specific targeting of fibrinogen for therapeutic intervention in multiple sclerosis
  5. Physiological role of the neurotrophin receptor p75NTR in biological processes

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Lab Members

Bernat Baeza-Raja, Ph.D., Research Scientist
Sophia Bardehle, Ph.D., Postdoctoral Fellow
Belinda Cabriga, Research Associate
Ester Canto Puig, Ph.D., Visiting Postdoctoral Fellow
Dimitrios Davalos, Ph.D., Staff Research Scientist
Tracey Dunitz, Administrative Assistant
Mark Petersen, M.D., Clinical Instructor
Victoria Rafalski, Ph.D., Postdoctoral Fellow
Pamela Rios, Research Associate
Jae Kyu Ryu, Ph.D., Staff Research Scientist
Catriona Syme, Ph.D., Research Associate

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Selected Publications

Schachtrup C, Ryu JK, Mammadzada K, Khan AS, Carlton PM, Perez A, Christian F, Le Moan N, Vagena E, Baeza-Raja B, Rafalski V, Chan JP, Nitschke R, Houslay MD, Ellisman MH, Wyss-Coray T, Palop JJ, Akassoglou K. Nuclear pore complex remodeling by p75NTR cleavage controls TGF-β signaling and astrocyte functions. Nat Neurosci, 2015. doi: 10.1038/nn.4054. 

Davalos D, Ryu JK, Merlini M, Baeten KM, Le Moan N, Petersen MA, Deerinck TJ, Smirnoff DS, Bedard C, Hakozaki H, Gonias Murray S, Ling JB, Lassmann H, Degen JL, Ellisman MH, Akassoglou K. Fibrinogen-induced perivascular microglial clustering is required for the development of axonal damage in neuroinflammation. Nature Commun, 2012. 3:1227.

Baeza-Raja B, Li P, Le Moan N, Sachs BD, Schachtrup C, Davalos D, Vagena E, Bridges D, Kim C, Saltiel AR, Olefsky JM, Akassoglou K. p75 neurotrophin receptor regulates glucose homeostasis and insulin sensitivity. PNAS, 2012. 109:5838-43.

Le Moan N, Houslay DM, Christian F, Houslay MD, Akassoglou K. Oxygen-dependent cleavage of the p75 neurotrophin receptor triggers stabilization of HIF-1 alpha. Mol Cell, 2011. 44:476-90.

Schachtrup C, Ryu JK, Helmrick M, Vagena E, Galanakis DK, Degen JL, Margolis RU, Akassoglou K. Fibrinogen triggers astrocyte scar formation by promoting availability of active TGFβ after vascular damage. J Neurosci, 2010. 30:5843-54.

Rius J, Guma M, Schachtrup C, Akassoglou K,  Zinkernagel AS, Nizet V, Johnson RS, Haddad GG & Karin M. NF-kB links innate immunity to the hypoxic response through transcriptional regulation of HIF-1α. Nature, 2008. 453:807-11.

Davalos D, Lee JK, Brinkman B, Zheng B, Akassoglou K. Stable in vivo imaging of densely populated glia, axons and blood vessels in the mouse spinal cord using two-photon microscopy. J Neurosci Methods, 2008. 169:1-7. Selected for Cover

Adams RA, Schachtrup C, Davalos D, Tsigelny I, Akassoglou K. Fibrinogen signal transduction as a mediator and therapeutic target in inflammation: Lessons from multiple sclerosis. Curr Med Chem, 2007, 14:2925-36.

Schachtrup C, Lu P, Lee JK, Jones L, Sachs BD, Ju J, Zheng B, Akassoglou K. Fibrinogen inhibits neurite outgrowth via β3 integrin-mediated transactivation of the EGF receptor. Proc Natl Acad Scie USA, 2007. 104:11814-19.

Sachs BD, Baillie GS, McCall JR, Passino MA, Schachtrup C, Wallace DA, Dunlop AJ, MacKenzie KF, Klussmann E, Lynch MJ, Sikorski SL, Nuriel T, Tsigelny I, Zhang J, Houslay MD, Chao MV, Akassoglou K. p75 neurotrophin receptor regulates tissue fibrosis through inhibition of plasminogen activation via a PDE4/cAMP/PKA pathway. J Cell Biol, 2007. 177:1119-32.

Passino MA, Adams, RA, Sikorski SL, Akassoglou K. Regulation of hepatic stellate cell differentiation by the neurotrophin receptor p75NTR. Science, 2007. 315:1853-56

Adams RA, Bauer J, Flick MJ, Sikorski SL, Nuriel T, Lassmann H, Degen JL, Akassoglou K. The fibrin-derived γ377-395 peptide inhibits microglia activation and reverses relapsing paralysis in central nervous system autoimmune disease. J Exp Med, 2007. 204:571-582. Selected for Cover

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Katerina Akassoglou, Ph.D.



Email

kakassoglou@gladstone.ucsf.edu

Phone

415-734-2512
415-355-0824(fax)

Office Address

Gladstone Institute of Neurological Disease
1650 Owens Street, room 312
San Francisco, CA 94158

Other Websites

Lab Website

Gladstone Website