Travis Conley

All Publications

• Restoring hippocampal glucose metabolism rescues cognition across Alzheimer's disease pathologies. Science (New York, N.Y.) Minhas, P. S., Jones, J. R., Latif-Hernandez, A., Sugiura, Y., Durairaj, A. S., Wang, Q., Mhatre, S. D., Uenaka, T., Crapser, J., Conley, T., Ennerfelt, H., Jung, Y. J., Liu, L., Prasad, P., Jenkins, B. C., Ay, Y. A., Matrongolo, M., Goodman, R., Newmeyer, T., Heard, K., Kang, A., Wilson, E. N., Yang, T., Ullian, E. M., Serrano, G. E., Beach, T. G., Wernig, M., Rabinowitz, J. D., Suematsu, M., Longo, F. M., McReynolds, M. R., Gage, F. H., Andreasson, K. I. 2024; 385 (6711): eabm6131

  Abstract

  Impaired cerebral glucose metabolism is a pathologic feature of Alzheimer's disease (AD), with recent proteomic studies highlighting disrupted glial metabolism in AD. We report that inhibition of indoleamine-2,3-dioxygenase 1 (IDO1), which metabolizes tryptophan to kynurenine (KYN), rescues hippocampal memory function in mouse preclinical models of AD by restoring astrocyte metabolism. Activation of astrocytic IDO1 by amyloid beta and tau oligomers increases KYN and suppresses glycolysis in an aryl hydrocarbon receptor-dependent manner. In amyloid and tau models, IDO1 inhibition improves hippocampal glucose metabolism and rescues hippocampal long-term potentiation in a monocarboxylate transporter-dependent manner. In astrocytic and neuronal cocultures from AD subjects, IDO1 inhibition improved astrocytic production of lactate and uptake by neurons. Thus, IDO1 inhibitors presently developed for cancer might be repurposed for treatment of AD.

  View details for DOI 10.1126/science.abm6131

  View details for PubMedID 39172838

• Bone manganese is a sensitive biomarker of ongoing elevated manganese exposure, but does not accumulate across the lifespan. ENVIRONMENTAL RESEARCH Conley, T. E., Richardson, C., Pacheco, J., Dave, N., Jursa, T., Guazzetti, S., Lucchini, R. G., Fendorf, S., Ritchie, R. O., Smith, D. R. 2021; 204 (Part D): 112355

  View details for DOI 10.1016/j.envres.2021.112355

• Bone manganese is a sensitive biomarker of ongoing elevated manganese exposure, but does not accumulate across the lifespan. Environmental research Conley, T. E., Richardson, C., Pacheco, J., Dave, N., Jursa, T., Guazzetti, S., Lucchini, R. G., Fendorf, S., Ritchie, R. O., Smith, D. R. 2021: 112355

  Abstract

  Studies have established associations between environmental and occupational manganese (Mn) exposure and executive and motor function deficits in children, adolescents, and adults. These health risks from elevated Mn exposure underscore the need for effective exposure biomarkers to improve exposure classification and help detect/diagnose Mn-related impairments. Here, neonate rats were orally exposed to 0, 25, or 50 mg Mn/kg/day during early life (PND 1-21) or lifelong through ∼ PND 500 to determine the relationship between oral Mn exposure and blood, brain, and bone Mn levels over the lifespan, whether Mn accumulates in bone, and whether elevated bone Mn altered the local atomic and mineral structure of bone, or its biomechanical properties. Additionally, we assessed levels of bone Mn compared to bone lead (Pb) in aged humans (age 41-91) living in regions impacted by historic industrial ferromanganese activity. The animal studies show that blood, brain, and bone Mn levels naturally decrease across the lifespan without elevated Mn exposure. With elevated exposure, bone Mn levels were strongly associated with blood Mn levels, bone Mn was more sensitive to elevated exposures than blood or brain Mn, and Mn did not accumulate with lifelong elevated exposure. Elevated early life Mn exposure caused some changes in bone mineral properties, including altered local atomic structure of hydroxyapatite, along with some biomechanical changes in bone stiffness in weanlings or young adult animals. In aged humans, blood Mn ranged from 5.4 to 23.5 ng/mL; bone Mn was universally low, and decreased with age, but did not vary based on sex or female parity history. Unlike Pb, bone Mn showed no evidence of accumulation over the lifespan, and may not be a biomarker of cumulative long-term exposure. Thus, bone may be a useful biomarker of recent ongoing Mn exposure in humans, and may be a relatively minor target of elevated exposure.

  View details for DOI 10.1016/j.envres.2021.112355

  View details for PubMedID 34774504

• Early postnatal manganese exposure causes arousal dysregulation and lasting hypofunctioning of the prefrontal cortex catecholaminergic systems JOURNAL OF NEUROCHEMISTRY Conley, T. E., Beaudin, S. A., Lasley, S. M., Fornal, C. A., Hartman, J., Uribe, W., Khan, T., Strupp, B. J., Smith, D. R. 2020; 153 (5): 631-649

  Abstract

  Studies have reported associations between environmental manganese (Mn) exposure and impaired cognition, attention, impulse control, and fine motor function in children. Our recent rodent studies established that elevated Mn exposure causes these impairments. Here, rats were exposed orally to 0, 25, or 50 mg Mn kg-1  day-1 during early postnatal life (PND 1-21) or lifelong to determine whether early life Mn exposure causes heightened behavioral reactivity in the open field, lasting changes in the catecholaminergic systems in the medial prefrontal cortex (mPFC), altered dendritic spine density, and whether lifelong exposure exacerbates these effects. We also assessed astrocyte reactivity (glial fibrillary acidic protein, GFAP), and astrocyte complement C3 and S100A10 protein levels as markers of A1 proinflammatory or A2 anti-inflammatory reactive astrocytes. Postnatal Mn exposure caused heightened behavioral reactivity during the first 5-10 min intervals of daily open field test sessions, consistent with impairments in arousal regulation. Mn exposure reduced the evoked release of norepinephrine (NE) and caused decreased protein levels of tyrosine hydroxylase (TH), dopamine (DA) and NE transporters, and DA D1 receptors, along with increased DA D2 receptors. Mn also caused a lasting increase in reactive astrocytes (GFAP) exhibiting increased A1 and A2 phenotypes, with a greater induction of the A1 proinflammatory phenotype. These results demonstrate that early life Mn exposure causes broad lasting hypofunctioning of the mPFC catecholaminergic systems, consistent with the impaired arousal regulation, attention, impulse control, and fine motor function reported in these animals, suggesting that mPFC catecholaminergic dysfunction may underlie similar impairments reported in Mn-exposed children.

  View details for DOI 10.1111/jnc.14934

  View details for Web of Science ID 000506490800001

  View details for PubMedID 31811785

  View details for PubMedCentralID PMC7261255