Central nervous system insulin signaling can influence the rate of insulin influx into brain

Abstract Background Insulin transport across the blood-brain barrier (BBB) is a highly regulated, saturable process, known to be affected by many peripheral substrates including insulin itself and triglycerides. This is in contrast to insulin leakage into peripheral tissues. Whether the central nerv...

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Main Authors: Van Nguyen, Peter Thomas, Sarah Pemberton, Alice Babin, Cassidy Noonan, Riley Weaver, William A. Banks, Elizabeth M. Rhea
Format: Article
Language:English
Published: BMC 2023-04-01
Series:Fluids and Barriers of the CNS
Subjects:
Online Access:https://doi.org/10.1186/s12987-023-00431-6
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author Van Nguyen
Peter Thomas
Sarah Pemberton
Alice Babin
Cassidy Noonan
Riley Weaver
William A. Banks
Elizabeth M. Rhea
author_facet Van Nguyen
Peter Thomas
Sarah Pemberton
Alice Babin
Cassidy Noonan
Riley Weaver
William A. Banks
Elizabeth M. Rhea
author_sort Van Nguyen
collection DOAJ
description Abstract Background Insulin transport across the blood-brain barrier (BBB) is a highly regulated, saturable process, known to be affected by many peripheral substrates including insulin itself and triglycerides. This is in contrast to insulin leakage into peripheral tissues. Whether the central nervous system (CNS) can control the rate of insulin uptake by brain remains to be determined. Insulin BBB interactions are impaired in Alzheimer’s disease (AD) and CNS insulin resistance is widely prevalent in AD. Therefore, if CNS insulin controls the rate of insulin transport across the BBB, then the defective transport of insulin seen in AD could be one manifestation of the resistance to CNS insulin observed in AD. Methods We investigated whether enhancing CNS insulin levels or induction of CNS insulin resistance using an inhibitor of the insulin receptor altered the blood-to-brain transport of radioactively labeled insulin in young, healthy mice. Results We found that insulin injected directly into the brain decreased insulin transport across the BBB for whole brain and the olfactory bulb in male mice, whereas insulin receptor blockade decreased transport in female mice for whole brain and hypothalamus. Intranasal insulin, currently being investigated as a treatment in AD patients, decreased transport across the BBB of the hypothalamus. Conclusions These results suggest CNS insulin can control the rate of insulin brain uptake, connecting CNS insulin resistance to the rate of insulin transport across the BBB.
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spelling doaj.art-721418f3fb0d4d6abdc9caff869d86332023-04-23T11:25:55ZengBMCFluids and Barriers of the CNS2045-81182023-04-0120111610.1186/s12987-023-00431-6Central nervous system insulin signaling can influence the rate of insulin influx into brainVan Nguyen0Peter Thomas1Sarah Pemberton2Alice Babin3Cassidy Noonan4Riley Weaver5William A. Banks6Elizabeth M. Rhea7School of Medicine, University of WashingtonGeriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care SystemGeriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care SystemGeriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care SystemGeriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care SystemGeriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care SystemGeriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care SystemGeriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care SystemAbstract Background Insulin transport across the blood-brain barrier (BBB) is a highly regulated, saturable process, known to be affected by many peripheral substrates including insulin itself and triglycerides. This is in contrast to insulin leakage into peripheral tissues. Whether the central nervous system (CNS) can control the rate of insulin uptake by brain remains to be determined. Insulin BBB interactions are impaired in Alzheimer’s disease (AD) and CNS insulin resistance is widely prevalent in AD. Therefore, if CNS insulin controls the rate of insulin transport across the BBB, then the defective transport of insulin seen in AD could be one manifestation of the resistance to CNS insulin observed in AD. Methods We investigated whether enhancing CNS insulin levels or induction of CNS insulin resistance using an inhibitor of the insulin receptor altered the blood-to-brain transport of radioactively labeled insulin in young, healthy mice. Results We found that insulin injected directly into the brain decreased insulin transport across the BBB for whole brain and the olfactory bulb in male mice, whereas insulin receptor blockade decreased transport in female mice for whole brain and hypothalamus. Intranasal insulin, currently being investigated as a treatment in AD patients, decreased transport across the BBB of the hypothalamus. Conclusions These results suggest CNS insulin can control the rate of insulin brain uptake, connecting CNS insulin resistance to the rate of insulin transport across the BBB.https://doi.org/10.1186/s12987-023-00431-6Blood-brain barrierInsulin receptorInsulin resistanceAlzheimer’s disease
spellingShingle Van Nguyen
Peter Thomas
Sarah Pemberton
Alice Babin
Cassidy Noonan
Riley Weaver
William A. Banks
Elizabeth M. Rhea
Central nervous system insulin signaling can influence the rate of insulin influx into brain
Fluids and Barriers of the CNS
Blood-brain barrier
Insulin receptor
Insulin resistance
Alzheimer’s disease
title Central nervous system insulin signaling can influence the rate of insulin influx into brain
title_full Central nervous system insulin signaling can influence the rate of insulin influx into brain
title_fullStr Central nervous system insulin signaling can influence the rate of insulin influx into brain
title_full_unstemmed Central nervous system insulin signaling can influence the rate of insulin influx into brain
title_short Central nervous system insulin signaling can influence the rate of insulin influx into brain
title_sort central nervous system insulin signaling can influence the rate of insulin influx into brain
topic Blood-brain barrier
Insulin receptor
Insulin resistance
Alzheimer’s disease
url https://doi.org/10.1186/s12987-023-00431-6
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