TY - JOUR
T1 - Distinct modulation of voltage-gated and ligand-gated Ca2+ currents by PPAR-γ agonists in cultured hippocampal neurons
AU - Pancani, Tristano
AU - Phelps, Jeremiah T.
AU - Searcy, James L.
AU - Kilgore, Michael W.
AU - Chen, Kuey Chu
AU - Porter, Nada M.
AU - Thibault, Olivier
PY - 2009/6
Y1 - 2009/6
N2 - Type 2 diabetes mellitus is a metabolic disorder characterized by hyperglycemia and is especially prevalent in the elderly. Because aging is a risk factor for type 2 diabetes mellitus, and insulin resistance may contribute to the pathogenesis of Alzheimer's disease (AD), anti-diabetic agents (thiazolidinediones-TZDs) are being studied for the treatment of cognitive decline associated with AD. These agents normalize insulin sensitivity in the periphery and can improve cognition and verbal memory in AD patients. Based on evidence that Ca2+ dysregulation is a pathogenic factor of brain aging/AD, we tested the hypothesis that TZDs could impact Ca2+ signaling/homeostasis in neurons. We assessed the effects of pioglitazone and rosiglitazone (TZDs) on two major sources of Ca2+ influx in primary hippocampal cultured neurons, voltage-gated Ca2+ channel (VGCC) and the NMDA receptor (NMDAR). VGCC- and NMDAR-mediated Ca2+ currents were recorded using patch-clamp techniques, and Ca2+ intracellular levels were monitored with Ca2+ imaging techniques. Rosiglitazone, but not pioglitazone reduced VGCC currents. In contrast, NMDAR-mediated currents were significantly reduced by pioglitazone but not rosiglitazone. These results show that TZDs modulate Ca2+-dependent pathways in the brain and have different inhibitory profiles on two major Ca2+ sources, potentially conferring neuroprotection to an area of the brain that is particularly vulnerable to the effects of aging and/or AD.
AB - Type 2 diabetes mellitus is a metabolic disorder characterized by hyperglycemia and is especially prevalent in the elderly. Because aging is a risk factor for type 2 diabetes mellitus, and insulin resistance may contribute to the pathogenesis of Alzheimer's disease (AD), anti-diabetic agents (thiazolidinediones-TZDs) are being studied for the treatment of cognitive decline associated with AD. These agents normalize insulin sensitivity in the periphery and can improve cognition and verbal memory in AD patients. Based on evidence that Ca2+ dysregulation is a pathogenic factor of brain aging/AD, we tested the hypothesis that TZDs could impact Ca2+ signaling/homeostasis in neurons. We assessed the effects of pioglitazone and rosiglitazone (TZDs) on two major sources of Ca2+ influx in primary hippocampal cultured neurons, voltage-gated Ca2+ channel (VGCC) and the NMDA receptor (NMDAR). VGCC- and NMDAR-mediated Ca2+ currents were recorded using patch-clamp techniques, and Ca2+ intracellular levels were monitored with Ca2+ imaging techniques. Rosiglitazone, but not pioglitazone reduced VGCC currents. In contrast, NMDAR-mediated currents were significantly reduced by pioglitazone but not rosiglitazone. These results show that TZDs modulate Ca2+-dependent pathways in the brain and have different inhibitory profiles on two major Ca2+ sources, potentially conferring neuroprotection to an area of the brain that is particularly vulnerable to the effects of aging and/or AD.
KW - Aging
KW - Alzheimer's disease
KW - Ca signaling
KW - Diabetes
KW - Electrophysiology
KW - Neuroprotection
UR - http://www.scopus.com/inward/record.url?scp=65949114415&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=65949114415&partnerID=8YFLogxK
U2 - 10.1111/j.1471-4159.2009.06107.x
DO - 10.1111/j.1471-4159.2009.06107.x
M3 - Article
C2 - 19453298
AN - SCOPUS:65949114415
SN - 0022-3042
VL - 109
SP - 1800
EP - 1811
JO - Journal of Neurochemistry
JF - Journal of Neurochemistry
IS - 6
ER -