Lalitha Madhavan
Associate Professor, BIO5 Institute
Associate Professor, Clinical Translational Sciences
Associate Professor, Evelyn F Mcknight Brain Institute
Associate Professor, Medicine
Associate Professor, Molecular and Cellular Biology
Associate Professor, Neurology
Associate Professor, Neuroscience - GIDP
Associate Professor, Physiological Sciences - GIDP
Primary Department
Department Affiliations
(520) 626-2330
Research Interest
Dr. Madhavan M.D., PhD, is an Assistant Professor of Neurology at the University of Arizona. She is also a member of the Arizona Cancer Center and the Evelyn F. McKnight Brain Institute, and is affiliated with the Neuroscience, Physiology and Molecular, Cellular Biology graduate programs at UA.Dr. Madhavan’s research centers on stem cells and neurological diseases. The ultimate goal of the work is to devise brain repair strategies for neural disorder using stem cells, and other alternate approaches. Currently, her lab is focused on Parkinson’s Disease, and is engaged in three main endeavors: (1) Understanding the therapeutic potential of stem cells in the context of aging, (2) Creating patient-specific induced pluripotent stem cells to study the etiology of Parkinson’s Disease, and (3) Testing the therapeutic feasibility of various types of adult stem cells in preclinical Parkinson’s Disease models. These projects are united by a common goal, which is to investigate core problems hindering the development of effective stem cell-based therapies for Parkinson’s Disease. In addition, the work represents a novel path of research for not only Parkinson’s Disease therapy, but has broad implications for developing treatments for several other age-related neurodegenerative disorders.

Publications

Corenblum, M. J., Flores, A. J., Badowski, M., Harris, D. T., & Madhavan, L. (2015). Systemic human CD34(+) cells populate the brain and activate host mechanisms to counteract nigrostriatal degeneration. Regenerative medicine, 10(5), 563-77.

Here we investigated the neuroprotective potential of systemic CD34(+) human cord blood cells (hCBCs) in a 6-hydroxydopamine rat model of Parkinson's disease.

Madhavan, L., Ourednik, V., & Ourednik, J. (2006). Increased "vigilance" of antioxidant mechanisms in neural stem cells potentiates their capability to resist oxidative stress. Stem cells (Dayton, Ohio), 24(9), 2110-9.

Although the potential value of transplanted and endogenous neural stem cells (NSCs) for the treatment of the impaired central nervous system (CNS) has widely been accepted, almost nothing is known about their sensitivity to the hostile microenvironment in comparison to surrounding, more mature cell populations. Since many neuropathological insults are accompanied by oxidative stress, this report compared the alertness of antioxidant defense mechanisms and cell survival in NSCs and postmitotic neural cells (PNCs). Both primary and immortalized cells were analyzed. At steady state, NSCs distinguished themselves in their basal mitochondrial metabolism from PNCs by their lower reactive oxygen species (ROS) levels and higher expression of the key antioxidant enzymes uncoupling protein 2 (UCP2) and glutathione peroxidase (GPx). Following exposure to the mitochondrial toxin 3-nitropropionic acid, PNC cultures were marked by rapidly decreasing mitochondrial activity and increasing ROS content, both entailing complete cell loss. NSCs, in contrast, reacted by fast upregulation of UCP2, GPx, and superoxide dismutase 2 and successfully recovered from an initial deterioration. This recovery could be abolished by specific antioxidant inhibition. Similar differences between NSCs and PNCs regarding redox control efficiency were detected in both primary and immortalized cells. Our first in vivo data from the subventricular stem cell niche of the adult mouse forebrain corroborated the above observations and revealed strong baseline expression of UCP2 and GPx in the resident, proliferating NSCs. Thus, an increased "vigilance" of antioxidant mechanisms might represent an innate characteristic of NSCs, which not only defines their cell fate, but also helps them to encounter oxidative stress in diseased CNS.

Madhavan, L., & Collier, T. J. (2010). A synergistic approach for neural repair: cell transplantation and induction of endogenous precursor cell activity. Neuropharmacology, 58(6), 835-44.

Stem cell research offers enormous potential for treating many diseases of the nervous system. At present, therapeutic strategies in stem cell research segregate into two approaches: cell transplantation or endogenous cell stimulation. Realistically, future cell therapies will most likely involve a combination of these two approaches, a theme of our current research. Here, we propose that there exists a 'synergy' between exogenous (transplanted) and endogenous stem cell actions that can be utilized to achieve therapeutic ends. Elucidating mechanisms underlying this exogenous-endogenous stem cell synergism may lead to the development of optimal cell therapies for neural disorders.

Madhavan, L. (2015). Redox-based regulation of neural stem cell function and Nrf2. Biochemical Society transactions, 43(4), 627-31.

Neural stem cells (NSCs) play vital roles in the development and maintenance of brain tissues throughout life. They can also potentially act as powerful sources of regeneration and repair during pathology to replace degenerating cells and counteract deleterious changes in the tissue microenvironment. However, both aging and neurodegeneration involve an up-regulation of processes, such as oxidative stress, inflammation, somatic mutations, and reduction in growth factors in neural tissues, which threaten the robust functioning of NSCs. Nevertheless, recent evidence also indicates that NSCs may possess the intrinsic capability to cope with such stressors in their microenvironment. Whereas the mechanisms governing the responses of NSCs to stress are diverse, a common theme that is emerging suggests that underlying changes in intracellular redox status are crucial. Here we discuss such redox-based regulation of NSCs, particularly in relation to nuclear erythroid factor 2-like 2 (Nrf2), which is a key cellular stress resistance factor, and its implications for successfully harnessing NSC therapeutic potential towards developing cell-based therapeutics for nervous system disorders.

Paumier, K. L., Siderowf, A. D., Auinger, P., Oakes, D., Madhavan, L., Espay, A. J., Revilla, F. J., Collier, T. J., & , P. S. (2012). Tricyclic antidepressants delay the need for dopaminergic therapy in early Parkinson's disease. Movement disorders : official journal of the Movement Disorder Society, 27(7), 880-7.

This study examined whether antidepressants delay the need for dopaminergic therapy or change the degree of motor impairment and disability in a population of early Parkinson's disease (PD) patients. Preclinical studies have indicated that antidepressants modulate signaling pathways involved in cell survival and plasticity, suggesting they may serve to both treat PD-associated depression and slow disease progression. A patient-level meta-analysis included 2064 patients from the treatment and placebo arms of the following trials: FS1, FS-TOO, ELLDOPA, QE2, TEMPO, and PRECEPT. Depression severity was determined at baseline, and antidepressant use was reported in a medication log each visit. Kaplan-Meier curves and time-dependent Cox proportional hazards models determined associations between depression severity and antidepressant use with the primary outcome, time to initiation of dopaminergic therapy. ANCOVAs determined associations with the secondary outcome, degree of motor impairment and disability, reported as annualized change in UPDRS scores from baseline to final visit. When controlling for baseline depression, the initiation of dopaminergic therapy was delayed for subjects taking tricyclic antidepressants compared with those not taking antidepressants. No significant differences were found in UPDRS scores for subjects taking antidepressants compared with those not taking antidepressants. Tricyclic antidepressants are associated with a delay in reaching the end point of need to start dopaminergic therapy. The lack of change in overall UPDRS scores suggests the delay was not attributable to symptomatic effects.