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Hanna Awarded an NSF Fellowship! UNC Biochemistry and Biophysics Spotlight

December 20, 2017
Hanna was one of two Biochemistry and Biophysics students to be awarded the National Science Foundation (NSF) Fellowship!  An excerpt from the full article on the UNC School of Medicine website can be found below:

Two biochemistry and biophysics grad students awarded NSF Fellowships

Congratulations to Candice Crilly and Hanna Trzeciakiewicz for receiving Predoctoral Fellowships from the National Science Foundation!

Two biochemistry and biophysics grad students awarded NSF Fellowships
click to enlarge(left to right) Hanna Trzeciakiewicz and Candice Crilly

The National Science Foundation predoctoral fellowships are designed to help ensure the vitality of the human resource base of science and engineering in the United States and reinforces its diversity.  The program recognizes and supports outstanding graduate students in NSF-supported science, technology, engineering, and mathematics disciplines who are pursuing research-based master’s and doctoral degrees at accredited US institutions.

The Tau Post-Translational Modification Puzzle

November 22, 2017

Can you solve it?

Microtubule associated-protein tau (tau for short) is a microtubule stabilizing protein most commonly found in neurons.  Tau helps regulate transport of other proteins by binding or falling off of microtubules.

Michala Kolarova, Francisco García-Sierra, Ales Bartos, Jan Ricny, and Daniela Ripova, “Structure and Pathology of Tau Protein in Alzheimer Disease,” International Journal of Alzheimer’s Disease, vol. 2012, Article ID 731526, 13 pages, 2012. doi:10.1155/2012/731526

The binding affinity and cellular localization of tau can vary, and is regulated by many post-translational modifications (PTMs), including ubiquitination, SUMOylation, acetylation, and phosphorylation.  These PTMs act like little switches on a microchip, and are attached and removed by enzymes like kinases, phosphatases, acetyltransferases, deacetylases and ubiquitin ligases that are in turn regulated by external stimuli including insulin signaling, glutamate, GABA, and neuropeptide receptors.

Mixing and matching of PTMs dynamically regulates neuronal polarization and dendritic branching.  When it goes awry, the cell makes too much aggregate-prone, hyperphosphorylated species of tau, a common hallmark of Alzheimer’s disease.  Hyperphosphorylated tau clumps with more tau to form tangles, which cause cell death and increase inflammation in the brain.  All the different PTMs and their relative effects on tau make for an incredibly complex profile, which we have taken to calling the “PTM code”.

Crack the Code!

Someone at BioMed took the time to build a huge database of tau PTMs.  Each one is mapped to the amino acid sequence of tau, and has the citation linked.  Check it out to see if you can solve the tau post translational modifcation puzzle, and crack the tau code!




Unraveling Alzheimer’s: The Cohen Lab Publishes Again

September 5, 2017

The Cohen Lab just published a new article, The Deacetylase HDAC6 Mediates Endogenous Neuritic Tau Pathology in Cell Press, and the UNC School of Medicine Newsroom Interviewed Dr. Cohen on the article!  A sneak peak:

Led by Todd Cohen, PhD, assistant professor of neurology, UNC scientists used human cell cultures to show how amyloid beta can trigger a dramatic inflammatory response in immune cells and how that interaction damages neurons. Then they showed how that kind of neuron damage leads to the formation of bead-like structures filled with abnormal tau protein. Similar bead-like structures are known to form in the brain cells of people with Alzheimer’s disease.



For the full UNC newsroom article, click here.

We were also featured in Medical News Today!

You can find their take on our work here. (Image source: Medical News Today)

doctor holding woman's hand
In a new study, researchers have pinpointed specific events that trigger and drive Alzheimer’s disease. This knowledge could be used to help find a cure.


For a full text PDF, click here.

Congrats to all the authors, especially the director of the project, Dr. Henry Tseng!



ALS: New Clues to the Cause and How Future Drugs Might Reverse Disease — News Room – UNC Health Care

July 24, 2017

Congrats to all working on the project!  We are closer to understanding the molecular pathology at work in ALS!

CHAPEL HILL, NC – Scientists have long known that a protein called TDP-43 clumps together in brain cells of people with amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s Disease, and is associated with neuron death. This same protein is thought to cause muscle degeneration in patients with sporadic inclusion body myositis (sIBM), leading many researchers to think that TDP-43 is one of the causative factors in ALS and sIBM. Now, UNC School of Medicine and NC State researchers found that a specific chemical modification called acetylation promotes TDP-43 clumping in animals. Using a natural anti-clumping method in mouse models, the scientists reversed protein clumping in muscle cells and prevented the sIBM-related muscle weakness.

Source: ALS: New Clues to the Cause and How Future Drugs Might Reverse Disease — News Room – UNC Health Care

Celebrating Publications!

June 9, 2017



The Cohen Lab recently celebrated the submission of two new publications:


A Dual Pathogenic Mechanism Links Tau Acetylation to Sporadic Tauopathy in Scientific Reports

Trzeciakiewicz H, Tseng JH, Wander CM, Madden V, Tripathy A, Yuan CX, Cohen TJ.




Acetylation-induced TDP-43 pathology is suppressed by an HSF1-dependent chaperone program in Nature Communications (Come back soon or contact us for a link!)

Ping Wang, Connor Wander, Chao-Xing Yuan, Michael Bereman, and Todd Cohen


With many more to come!

Celebrating publications is a tradition in the scientific community.  In Todd Cohen’s words, “Research isn’t all that gratifying.  You work for years in the lab about something nobody knows about and finally submit a paper… months later it hopefully gets accepted.  You have to take the opportunity to celebrate”. (Or he said something similar).

There are no upcoming events at this time.



Welcome to The Todd Cohen Lab at UNC Chapel Hill Website

June 1, 2016

Welcome to the new website for Todd Cohen’s Lab at UNC Chapel Hill!  We will be incrementally moving our online presence to this web address. You can find our old googlesites website here.

This is the digital home for Todd Cohen’s lab in the Department of Neurology at UNC Chapel Hill, not to be confused with Jessica Cohen’s Lab from Psychology and Neuroscience!


Learn more about the research being done in the Todd Cohen Lab at UNC Chapel Hill here.


This website will provide us with a unique platform for discussion and public interaction.  The forum section of the website is under construction, but check back soon!  Any burning questions for Todd Cohen’s Lab at UNC can be asked here.



Stay tuned for more updates!  Any feedback is appreciated as well!  Leave a comment below and tell us what you think.



Youjun Chen

June 28, 2015

Youjun received her Ph.D. degree in Cellular and Molecular Physiology from University of North Carolina at Chapel Hill in 2010 under the mentorship of Dr. William Snider. She stayed in Dr. Snider’s lab for one additional year as a post-doctoral research fellow. Her research focus in the Snider lab was studying the roles of Adenomatous Polyposis Coli (APC) in neuronal morphogenesis. Youjun worked at The Scripps Research Institute as a postdoctoral research associate studying autism and brain development. She returned to UNC-Chapel Hill and joined the Cohen lab in 2016.

Connor Wander – Pharmacology

June 27, 2015


Connor graduated from Virginia Tech with a B.S. in Biology and Biochemistry in 2014, and joined the lab as a technician for two years. He then joined the Cohen and Song Labs as a graduate student where he studied astrocytes and inhibitory networks in Alzheimer’s Disease. Connor runs a science communication podcast and website,  Straight from a Scientist (SFS).  Currently, Connor studies model systems for cerebrovascular disease in the context of plasma biology at Alkahest, Inc in San Carlos, CA. Outside of the lab, he enjoys hiking, swimming, graphic design, gaming, Brazilian Jiu Jitsu, paintball and caring for his bearded dragons.




Hanna Trzeciakiewicz – Biochemistry and Biophysics

June 27, 2015

Hanna is a fifth year PhD candidate and NSF-GRFP fellow. She received a B.S. in Biochemistry (and minor in Spanish Language) from Oakland University in Michigan, where she was an undergraduate research assistant in Dr. Sanela Martic’s biochemistry laboratory investigating the misfolding and aggregation of the tau protein. After, she joined the Biological and Biomedical Sciences Program, the department of Biochemistry and Biophysics, and the Cohen lab at the University of North Carolina at Chapel Hill. She has been investigating many facets of tau protein biochemistry.