Kristian Doyle
Associate Professor, BIO5 Institute
Associate Professor, Immunobiology
Associate Professor, Neurology
Associate Professor, Neuroscience - GIDP
Associate Professor, Neurosurgery
Associate Professor, Psychology
Research Scientist
Primary Department
Department Affiliations
(520) 626-7013
Work Summary
Approximately 795,000 Americans suffer a stroke each year, and 400,000 will experience long-term disability. The number of stroke survivors in the population is expected to double by 2025. Currently, treatments for stroke patients are limited to tissue plasminogen activator (TPA), but its use is limited to the first few hours after stroke. Therefore, the goal of our research is to develop new therapeutics that can promote repair and recovery in this rapidly growing population.
Research Interest
The Doyle lab investigates the role of the immune system in causing dementia after stroke. Up to 30% of stroke patients develop dementia in the months and years after their stroke and we are testing the hypothesis that in some patients this is due to a chronic inflammatory response that persists at the site of the stroke infarct. We suspect that in the weeks, months and possibly years after stroke, neurotoxic inflammatory mediators, including T cells, cytokines and antibodies, leak out of the stroke infarct and cause bystander damage to the surrounding tissue, which then both impairs recovery, and in some instances leads to cognitive decline. In support of this hypothesis we have data that demonstrates that inflammation persists for months at the site of the infarct after stroke, and that a single stroke can directly lead to the development of immune-mediated delayed cognitive deficits. We are currently in the process of targeting different components of the prolonged inflammatory response to stroke to determine if post stroke dementia can be treated by selectively ablating individual immune mediators such as B lymphocytes, T lymphocytes, and CCR2. Keywords: Neuroinflammation, stroke, dementia, Alzheimer's disease

Publications

Bartlett, M. J., Flores, A. J., Dollish, H. K., Farrell, D. C., Parent, K. L., Besselsen, D. G., Heien, M. L., Doyle, K., Cowen, S. L., Steece-Collier, K., Sherman, S. J., & Falk, T. (2017). Neuroplastic mechanism of sub-anesthetic ketamine treatment to reduce development of L-DOPA-induced dyskinesia. Science Translational Medicine.
BIO5 Collaborators
David G Besselsen, Kristian Doyle
Doyle, K. P., & Buckwalter, M. S. (2014). A mouse model of permanent focal ischemia: distal middle cerebral artery occlusion. Methods in molecular biology (Clifton, N.J.), 1135, 103-10.

Here we provide a standardized protocol for performing distal middle cerebral artery occlusion (DMCAO) in mice. DMCAO is a method of inducing permanent focal ischemia that is commonly used as a rodent stroke model. To perform DMCAO a temporal craniotomy is performed, and the middle cerebral artery (MCA) is permanently ligated at a point downstream of the lenticulostriate branches. The size of the lesion produced by this surgery is strain dependent. In C57BL/6J mice, DMCAO produces an infarct predominantly restricted to the barrel region of the somatosensory cortex, but in BALB/cJ mice, DMCAO generates a much larger lesion that incorporates more of the somatosensory cortex and part of the M1 region of the motor cortex. The larger lesion produced by DMCAO in BALB/cJ mice produces a clearer sensorimotor deficit, which is useful for investigating recovery from stroke. We also describe how to modify DMCAO in C57BL/6J mice with the application of hypoxia to generate a lesion and sensorimotor deficit that are similar in size to those produced by DMCAO alone in BALB/cJ mice. This is extremely useful for stroke experiments that require a robust sensorimotor deficit in transgenic mice created on a C57BL/6J background.

Doyle, K. P., & Buckwalter, M. S. (2012). The double-edged sword of inflammation after stroke: what sharpens each edge?. Annals of neurology, 71(6), 729-31.
Doyle, K. P., Suchland, K. L., Ciesielski, T. M., Lessov, N. S., Grandy, D. K., Scanlan, T. S., & Stenzel-Poore, M. P. (2007). Novel thyroxine derivatives, thyronamine and 3-iodothyronamine, induce transient hypothermia and marked neuroprotection against stroke injury. Stroke; a journal of cerebral circulation, 38(9), 2569-76.

Mild hypothermia confers profound neuroprotection in ischemia. We recently discovered 2 natural derivatives of thyroxine, 3-iodothyronamine (T(1)AM) and thyronamine (T(0)AM), that when administered to rodents lower body temperature for several hours without induction of a compensatory homeostatic response. We tested whether T(1)AM- and T(0)AM-induced hypothermia protects against brain injury from experimental stroke.

Csiszar, A., Podlutsky, A., Podlutskaya, N., Sonntag, W. E., Merlin, S. Z., Philipp, E. E., Doyle, K., Davila, A., Recchia, F. A., Ballabh, P., Pinto, J. T., & Ungvari, Z. (2012). Testing the oxidative stress hypothesis of aging in primate fibroblasts: is there a correlation between species longevity and cellular ROS production?. The journals of gerontology. Series A, Biological sciences and medical sciences, 67(8), 841-52.

The present study was conducted to test predictions of the oxidative stress theory of aging assessing reactive oxygen species production and oxidative stress resistance in cultured fibroblasts from 13 primate species ranging in body size from 0.25 to 120 kg and in longevity from 20 to 90 years. We assessed both basal and stress-induced reactive oxygen species production in fibroblasts from five great apes (human, chimpanzee, bonobo, gorilla, and orangutan), four Old World monkeys (baboon, rhesus and crested black macaques, and patas monkey), three New World monkeys (common marmoset, red-bellied tamarin, and woolly monkey), and one lemur (ring-tailed lemur). Measurements of cellular MitoSox fluorescence, an indicator of mitochondrial superoxide (O2(·-)) generation, showed an inverse correlation between longevity and steady state or metabolic stress-induced mitochondrial O2(·-) production, but this correlation was lost when the effects of body mass were removed, and the data were analyzed using phylogenetically independent contrasts. Fibroblasts from longer-lived primate species also exhibited superior resistance to H(2)O(2)-induced apoptotic cell death than cells from shorter-living primates. After correction for body mass and lack of phylogenetic independence, this correlation, although still discernible, fell short of significance by regression analysis. Thus, increased longevity in this sample of primates is not causally associated with low cellular reactive oxygen species generation, but further studies are warranted to test the association between increased cellular resistance to oxidative stressor and primate longevity.