Limited studies indicate an important role of mitochondrial-derived factors in the control of the cerebral circulation beyond effects which are related to energy supply. Thus, factors which depolarize mitochondria and/or augment the release of ROS from mitochondria activate signaling pathways leading to net dilation of cerebral arteries. Furthermore, our preliminary data indicate that mitochondrial influences are adversely affected by insulin resistance (IR). Our overall hypothesis is that mitochondrial-derived influences are key regulators of cerebral vascular tone but are compromised by IR.
Two Specific Aims will test our hypotheses and speculations in rats:
Aim 1. Examination of the roles of mitochondrial-derived influences in mediating responses of cerebral arteries. We will: A) Determine the relationship among cerebral arterial vasodilation, mitochondrial depolarization, kinase activation, and mitochondrial ROS production. B) Elucidate the mechanisms of dilation due to mitochondrial depolarization, kinase activation, ROS generation, and plasmalemmal calcium-activated potassium channel opening. C) Evaluate the inter-relationships of mitochondrial-derived factors produced in endothelium and VSM cells in mediating integrated dilator responses. D) Determine whether preconditioning, induced by prior activation of mitochondrial-derived mechanisms, alters subsequent cerebrovascular responses to mitochondrial-derived products. E) Explore the relationship between physiological stimuli and mitochondrial activation.
Aim 2. Investigation of the effects of IR on mitochondrial-derived influences on cerebral arteries. We will: A) Examine whether IR attenuates dilator responses of cerebral arteries dependent upon mitochondria-derived signaling pathways. B) Determine the mechanisms by which IR reduces the responsiveness of cerebral arteries to mitochondrial-derived influences. C) Examine whether treatment of animals with statins restores normal responsiveness to mitochondrial-derived stimuli in IR. We expect that our results will lead to the improved treatment of patients suffering from cerebrovascular disease.
Chronic cerebral vascular insufficiency, which occurs in IR, leads to neurological diseases such as Alzheimer's disease and strokes. However, the potential role of mitochondrial dysfunction has not been studied. Current treatment regimens are not optimal and we expect that the results of our studies will lead to new and improved therapies to prevent or slow the onset of neurological diseases in an aging population.
|Sure, Venkata N; Sakamuri, Siva S V P; Sperling, Jared A et al. (2018) A novel high-throughput assay for respiration in isolated brain microvessels reveals impaired mitochondrial function in the aged mice. Geroscience 40:365-375|
|Merdzo, Ivan; Rutkai, Ibolya; Sure, Venkata N L R et al. (2017) Impaired Mitochondrial Respiration in Large Cerebral Arteries of Rats with Type 2 Diabetes. J Vasc Res 54:1-12|
|Merdzo, Ivan; Rutkai, Ibolya; Tokes, Tunde et al. (2016) The mitochondrial function of the cerebral vasculature in insulin-resistant Zucker obese rats. Am J Physiol Heart Circ Physiol 310:H830-8|
|Katakam, Prasad V G; Dutta, Somhrita; Sure, Venkata N et al. (2016) Depolarization of mitochondria in neurons promotes activation of nitric oxide synthase and generation of nitric oxide. Am J Physiol Heart Circ Physiol 310:H1097-106|
|Rutkai, Ibolya; Dutta, Somhrita; Katakam, Prasad V et al. (2015) Dynamics of enhanced mitochondrial respiration in female compared with male rat cerebral arteries. Am J Physiol Heart Circ Physiol 309:H1490-500|
|Dutta, Somhrita; Rutkai, Ibolya; Katakam, Prasad V G et al. (2015) The mechanistic target of rapamycin (mTOR) pathway and S6 Kinase mediate diazoxide preconditioning in primary rat cortical neurons. J Neurochem 134:845-56|
|Rutkai, Ibolya; Katakam, Prasad V G; Dutta, Somhrita et al. (2014) Sustained mitochondrial functioning in cerebral arteries after transient ischemic stress in the rat: a potential target for therapies. Am J Physiol Heart Circ Physiol 307:H958-66|
|Katakam, Prasad V G; Gordon, Angellica O; Sure, Venkata N L R et al. (2014) Diversity of mitochondria-dependent dilator mechanisms in vascular smooth muscle of cerebral arteries from normal and insulin-resistant rats. Am J Physiol Heart Circ Physiol 307:H493-503|
|Busija, David W; Katakam, Prasad V (2014) Mitochondrial mechanisms in cerebral vascular control: shared signaling pathways with preconditioning. J Vasc Res 51:175-89|
|Carvalho, Cristina; Katz, Paige S; Dutta, Somhrita et al. (2014) Increased susceptibility to amyloid-? toxicity in rat brain microvascular endothelial cells under hyperglycemic conditions. J Alzheimers Dis 38:75-83|
Showing the most recent 10 out of 22 publications