Kanaan Laboratory Research Topics
Alzheimer’s Disease and Other Tauopathies
Tauopathies are a group of diseases that are so named because they involve the pathological accumulation of tau protein. Chief among the tauopathies is Alzheimer’s disease (AD), the most common form of dementia. Non-AD tauopathies include various forms of frontotemporal dementias (FTDs), Pick’s disease, progressive supranuclear palsy and corticobasal degeneration. With the aged population rapidly expanding, these aging-related diseases pose significant healthcare and economic problems. The Kanaan laboratory focuses on two important factors in the pathogenesis of AD and non-AD tauopathies – the tau protein and axonal function.
|A section from the hippocampus of an Alzheimer’s disease patient stained with a tau antibody (TNT1 – recognizes amino acids 2-18, see below). Note the classical triad of tau pathologies in AD, 1) neurofibrillary tangles (arrowheads), 2) neuropil threads (arrows), and 3) a neuritic plaque (asterisk).|
Tau abnormalities in disease
in AD and tauopathies, tau proteins undergo significant modifications that include phosphorylation, aggregation and truncation, among others. The mechanisms by which these abnormally modified tau proteins contribute to disease pathogenesis are under intense investigation by the Kanaan laboratory. Recently, we identified a functional signaling motif in tau called the phosphatase-activating domain (PAD) that activates a protein phosphatase-1 / glycogen synthase kinase-3 (PP1/GSK3) signaling cascade. Interestingly, we found that disease-related modifications of tau induce abnormal exposure of PAD causing aberrant activation of the PP1/GSK3 pathway that ultimately results in the inhibition of axonal transport in the squid axoplasm model. The presence of abnormal, PAD-exposed forms of tau in both the axonal and somatodendritic compartments of neurons could affect numerous PP1/GSK3-mediated cellular processes leading to synaptic and axonal degeneration, and eventually neuron death.
|Abnormal exposure of PAD in tau proteins aberrantly activates a kinesin-regulating signaling cascade involving PP1 and GSK3β. PAD exposure causes activation of PP1 that in turn activates GSK3β by dephosphorylating serine 9 and then active GSK3β phosphorylates the light chains of the conventional kinesin motor complex causing dissociation of the cargoes. This mechanism specifically impairs anterograde fast axonal transport.|
Axon Function and Tau
A Diversity of Diseases with Tau Abnormalities
Current Research Projects
Project 2: We are interested in studying the role of tau proteins in aging and diseases that are known to include tau pathology, but are not traditionally characterized as tauopathies. This includes Parkinson’s disease, glaucoma and traumatic brain injury, among others.
Project 3: Ongoing studies are aimed at understanding the pathogenesis of Parkinson’s disease. Here we are performing studies aimed at pinpointing the mechanisms by which α-synuclein is neurotoxic and identifying whether tau and α-synuclein pathologies are related.
Kanaan Laboratory Personnel
Nicholas M. Kanaan, Ph.D.
Visit Dr. Kanaan's Faculty Profile
Dr. Kanaan grew up in Canton, MI and obtained a B.S. in Neuroscience, Psychology, and Sociology from Central Michigan University (Mt. Pleasant, MI). He then went to Chicago, IL to obtain a Ph.D. in Neurological Sciences from Rush University Medical Center, and then stayed in Chicago for his postdoctoral training with Dr. Lester Binder at Northwestern University. His interests outside of the lab include photography, woodworking, and fishing.
|Tessa Grabinski, B.S.
Tessa obtained a B.S. in Biochemistry from Alma College in 2004. She worked for Van Andel Institute for eight years in both the Antibody Technology Core and the Laboratory of Musculoskeletal Oncology. She joined the Kanaan Lab in the summer of 2012. Her interests outside the lab include hunting, enjoying the lake, and spending time with family and friends.
Benjamin Combs, Ph.D.
Ben obtained a Ph.D. from the University of Kansas in Molecular, Cellular, and Developmental Biology. While there he studied how modifications of the tau protein affect its function and aggregation in order to better understand the role of the protein in Alzheimer's disease and other tauopathies. Prior to this he received a B.S. in Electrical Engineering from Iowa State University. He is originally from Inman, KS and enjoys hiking, sports, and exploring new locations.
Kyle Christensen, B.S.
Kyle received his B.S. in Neuroscience from the University of Minnesota in 2012. As an undergraduate, he worked as a research assistant in the lab of Dr. Francisco Diez-Gonzalez investigating the biocontrol of foodborne pathogens. Additionally, Kyle worked in the lab of Dr. Michael Lee researching the structure and function of α-synuclein in Parkinson’s disease. Currently, he is a graduate student in the Neuroscience Program at Michigan State University, where his research interests focus on how modifications of tau protein contribute to Alzheimer's disease pathology and neurodegeneration. Outside the lab, Kyle enjoys sports, music, traveling, and reading.
Chelsea Tiernan, Ph.D.
Chelsea received her B.A. in Biology and Psychology from Western State College in Gunnison, CO in 2007, and then her Ph.D. in Neuroscience from Michigan State University in 2013. Her research focuses on the toxicity of tau oligomers in the cholinergic basal forebrain, and how the formation of these oligomers alters the expression of genes that encode proteins involved in intracellular transport. In her free time, she enjoys running, skiing, gardening, and cooking.
Chelsey Yob, B.S.
Chelsey obtained a B.S. in Biochemistry from Central Michigan University in 2014. After graduating, she worked as a research technician at Central Michigan University studying ways to target the glycoconjugates of the M. Tuberculosis cell membrane as a means of biological inquiry and therapeutic intervention. She joined the Kanaan Lab in the spring of 2014. Her interests outside the lab include cooking, sports, and traveling to the Upper Peninsula to spend time with family and friends.
Collin Richards, B.S.
Collin obtained a B.S. in Chemical Engineering with a concentration in Biomedical Engineering in 2016 from Michigan State University. He previously worked for the Dow Chemical Company in microbial control manufacturing in West Virginia. Collin is originally from Traverse City, MI, and enjoys hiking, camping, kayaking, and swimming.
Kris Cox, DVM – postdoctoral fellow
Carlos Nogueras-Ortiz – Visiting PhD Candidate, University of Puerto Rico
Emi Bulica – MSU Medical School Student
Matthew Orbain – MSU Undergraduate Student
Corey Shaffer – Catholic Central High School Student
- Cox K, Combs B, Abdelmesih B, Morfini G, Brady ST and Kanaan NM. Analysis of Isoform-specific Tau Aggregates Suggests a Common Toxic Mechanism Involving Similar Pathological Conformations and Axonal Transport Inhibition. Neurobiol Aging 2016. 47:113-126.
- Tiernan CT, Combs B, Cox K, Morfini G, Brady ST, Counts SE, and Kanaan NM. Pseudophosphorylation of Tau at S422 Enhances SDS-Stable Dimer Formation and Impairs Both Anterograde and Retrograde Fast Axonal Transport. Exp Neurol. 2016. 283(Pt A):318-329. PMID: 27373205. PMCID: PMC4992631.
- Combs B, Hamel C and Kanaan NM. Pathological conformations involving the amino terminus of tau occur early in Alzheimer's disease and are differentially detected by monoclonal antibodies. Neurobiol Dis. 2016 94:18-31. PMID: 27260838. PMCID: PMC4983528
- Kneynsberg A, Collier TJ, Manfredsson FP and Kanaan NM. Quantitative and semi-quantitative measurements of axonal degeneration in tissue and primary neuron cultures. J Neuro Meth. 2016. 266:32-41. PMID: 27031947. PMCID: PMC4874894.
- Kanaan NM, Cox K, Alvarez VE, Stein TD, Poncil S, McKee AC. Characterization of early pathological tau conformations and phosphorylation in chronic traumatic encephalopathy. J Neuropathol Exp Neurol. 2016. 75(1): 19-34. PMID: 26671985. PMCID: PMC4891281.
- Combs B, Kneynsberg A, Kanaan NM. Gene Therapy Models of Alzheimer’s Disease and Other Dementias. Methods Mol Biol. 2016 1382:339-66. PMID 26611599. PMCID: PMC4734109.
- Fá M, Puzzo D, Piacentini R, Staniszewski A, Zhang H, Baltrons MA, Li Puma DD, Chatterjee I, Li J, Saeed F, Berman HL, Ripoli C, Gulisano W, Gonzalez J, Tian H, Costa JA, Lopez P, Davidowitz E, Yu WH, Haroutunian V, Brown LM, Palmeri A, Sigurdsson EM, Duf KE, Teich AF, Honig LS, Sierks M, Moe JG, D’Adamio L, Grassi C, Kanaan NM, Fraser PD, and Arancio O. Extracellular tau oligomers produce an immediate impairment of LTP and memory. Sci Rep. 2016, 6:19393. PMCID: PMC4726138.
- Grabinski TM, Kneynsberg A, Manfredsson FP and Kanaan NM. A method for combining RNAscope in situ hybridization with immunohistochemistry in thick free-floating brain sections and primary neuronal cultures. PLoS ONE. 2015. 10(3):1-19. PMCID: PMC4368734
- Kanaan NM, Pigino GF, Brady ST, Lazarov O, Binder LI, Morfini GA. Axonal degeneration in Alzheimer's disease: When signaling abnormalities meet the axonal transport system. Exp. Neurol. 2013; PMID: 22721767. PMCID: PMC3465504.
- Kanaan NM, Manfredsson FP. Loss of functional alpha-synuclein: a toxic event in Parkinson's disease? J Parkinson’s Dis. 2012;2(4):249-67. PMID: 23938255. PMCID: PMC4736738.
- Kanaan NM, Morfini GA, Pigino G, LaPointe NE, Andreadis A, Song Y, Leitman E, Binder LI, and Brady ST. Phosphorylation in the Amino Terminus of Tau Prevents Inhibition of Axonal Transport. Neurobiol of Aging, 2012; 33(4):826, 15-30. PMID: 21794954 PMCID: PMC3272324.
- Kanaan NM, Morfini GA, LaPointe NE, Pigino GF, Patterson KR, Song Y, Andreadis A, Fu Y, Brady ST, and Binder LI. Pathogenic Forms of Tau Inhibit Kinesin-Dependent Axonal Transport Through a Mechanism Involving Activation of Axonal Phosphotransferases. J. Neurosci. 2011; 31(27):9858-9868. PMID: 2173427. PMCID: PMC3391724.
- Collier, TJ, Kanaan NM**, Kordower JH. Aging as a primary risk factor for Parkinson’s disease: evidence from studies of non-human primates. Nat. Rev. Neurosci. 2011; 12(6):359-366. PMID: 21587290. PMCID: PMC3387674. **co-first authorship
- Patterson KR, Remmers C, Fu Y, Brooker S, Kanaan NM, Vana L, Ward S, Reyes JF, Philibert K, Glucksman MJ, Binder LI. Characterization of prefibrillar tau oligomers in vitro and in Alzheimer’s disease. JBC. 2011; 286(26):23063-23076. PMID: 21550980. PMCID: PMC3123074
- Morfini, G., Burns, M., Binder, L. Kanaan, N.M., LaPointe, N., Bosco, B., Brown, H., Brown, B., Jr, Tiwari, A., Hayward, L., Edgar, J., Atagi, Y., Song, Y., Pigino, G., and Brady, S. Axonal Transport Defects in Neurodegenerative Diseases. J. Neurosci. 2009; 29(41):12776-86. PMID: 19828789 PMCID: PMC2801051. “Highly Cited Paper” in Web of Science
To answer our scientific questions we use a combination of experimental approaches that includes biochemical assays (enzyme assays, immunoprecipitations, recombinant protein production), cell culture (primary neurons and numerous cell lines), gene therapy (lentiviruses and recombinant adeno-associated viruses), animal modeling (neurotoxin, transgenic mice, and virus-based models), postmortem human tissue analyses (staining and protein analyses), monoclonal antibody production, and numerous forms of microscopy (brightfield, fluorescence, electron microscopy). Here are some visual examples our work!
Double label immunohistochemistry of tau pathology (A – neurofibrillary tangles, B – neuritic plaque, and C – neuropil threads) in human AD brain. PAD-exposed tau (TNT1+, brown) and phosphorylated tyrosine 18 tau (9G3+, dark blue).
|Primary rat hippocampal culture. Neurons are labeled with tubulin (A-green), astrocytes with GFAP (B-red) and nuclei with DAPI (C-blue) (D-merged image).|
|Primary rat cortical neuron infected with lentivirus engineered to produce human tau protein. Green is neuronal tubulin (A-Tuj1+) and red is human tau (B-Tau12+) (C-merged image).|
|Primary rat cortical neurons cultured in microfluidic devices, which allow separation of cell bodies (left side) from axons (right side). Green is neuronal tubulin (Tuj1+) and red is mitochondria (ATP Synthase+).|
|Cell lines we typically use for various purposes. A – differentiated SH-SY5Y cells; B – MN9D cells stained with TH (red) and tubulin (green); and HEK 293T cells transfected with: C – GFP-Actin (green) and Tubulin (red); D – a bi-directional plasmid that produces dTomato (red) and GFP-synaptophysin (green); E – truncated human tau protein (red = R1 tau antibody and green = tau12 antibody); F – rat a-synuclein (green). (DAPI is blue for all images).|
|PAD-exposed tau in various brain regions of transgenic mice expressing a mutant form of tau protein (i.e. P301L mutant tau). Stained with the TNT1 antibody.|
|We utilize the Licor Odyssey system to perform double-label immunoblotting. A – Recombinant tau proteins; B - Tau from human control (Con) and Alzheimer’s disease (both soluble and insoluble fractions) brains; C – Samples from the retina, optic nerve (ON), and optic tract (OT) of rats.|
|Transmission electron microscope images of tau polymers generated by aggregating recombinant tau proteins in vitro (WT = wild-type tau, Y18E and Y29E = pseudophosphorylated tyrosine mutants, and Y18F = tyrosine to phenylalanine mutant).|
Sources of Funding
Dr. Kanaan, his trainees and laboratory staff are grateful for the generosity of the funding agencies, private foundations and philanthropists that provide the support necessary to continue their research efforts.
National Institute on Aging (NIH)
National Institute of Neurological Disease (NIH)
The Mercy Health Saint Mary’s Doran Foundation
The Jean P. Schultz Biomedical Research Fund
The Secchia Family Foundation