1
|
Ruiz-Uribe NE, Bracko O, Swallow M, Omurzakov A, Dash S, Uchida H, Xiang D, Haft-Javaherian M, Falkenhain K, Lamont ME, Ali M, Njiru BN, Chang HY, Tan AY, Xiang JZ, Iadecola C, Park L, Sanchez T, Nishimura N, Schaffer CB. Vascular oxidative stress causes neutrophil arrest in brain capillaries, leading to decreased cerebral blood flow and contributing to memory impairment in a mouse model of Alzheimer’s disease. bioRxiv 2023:2023.02.15.528710. [PMID: 36824768 PMCID: PMC9949082 DOI: 10.1101/2023.02.15.528710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
INTRODUCTION In this study, we explore the role of oxidative stress produced by NOX2-containing NADPH oxidase as a molecular mechanism causing capillary stalling and cerebral blood flow deficits in the APP/PS1 mouse model of AD. METHODS We inhibited NOX2 in APP/PS1 mice by administering a 10 mg/kg dose of the peptide inhibitor gp91-ds-tat i.p., for two weeks. We used in vivo two-photon imaging to measure capillary stalling, penetrating arteriole flow, and vascular inflammation. We also characterized short-term memory function and gene expression changes in cerebral microvessels. RESULTS We found that after NOX2 inhibition capillary stalling, as well as parenchymal and vascular inflammation, were significantly reduced. In addition, we found a significant increase in penetrating arteriole flow, followed by an improvement in short-term memory, and downregulation of inflammatory gene expression pathways. DISCUSSION Oxidative stress is a major mechanism leading to microvascular dysfunction in AD, and represents an important therapeutic target.
Collapse
|
2
|
Ali M, Falkenhain K, Njiru BN, Murtaza-Ali M, Ruiz-Uribe NE, Haft-Javaherian M, Catchers S, Nishimura N, Schaffer CB, Bracko O. VEGF signalling causes stalls in brain capillaries and reduces cerebral blood flow in Alzheimer's mice. Brain 2022; 145:1449-1463. [PMID: 35048960 PMCID: PMC9150081 DOI: 10.1093/brain/awab387] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 07/09/2021] [Accepted: 09/22/2021] [Indexed: 11/16/2022] Open
Abstract
Increased incidence of stalled capillary blood flow caused by adhesion of
leucocytes to the brain microvascular endothelium leads to a 17%
reduction of cerebral blood flow and exacerbates short-term memory loss in
multiple mouse models of Alzheimer’s disease. Here, we report that vascular endothelial growth factor (VEGF) signalling at the
luminal side of the brain microvasculature plays an integral role in the
capillary stalling phenomenon of the APP/PS1 mouse model. Administration of the anti-mouse VEGF-A164 antibody, an isoform that inhibits
blood–brain barrier hyperpermeability, reduced the number of stalled
capillaries within an hour of injection, leading to an immediate increase in
average capillary blood flow but not capillary diameter. VEGF-A inhibition also
reduced the overall endothelial nitric oxide synthase protein concentrations,
increased occludin levels and decreased the penetration of circulating Evans
Blue dye across the blood–brain barrier into the brain parenchyma,
suggesting increased blood–brain barrier integrity. Capillaries prone to
neutrophil adhesion after anti-VEGF-A treatment also had lower occludin
concentrations than flowing capillaries. Taken together, our findings demonstrate that VEGF-A signalling in APP/PS1 mice
contributes to aberrant endothelial nitric oxide synthase /occludin-associated
blood–brain barrier permeability, increases the incidence of capillary
stalls, and leads to reductions in cerebral blood flow. Reducing leucocyte
adhesion by inhibiting luminal VEGF signalling may provide a novel and
well-tolerated strategy for improving brain microvascular blood flow in
Alzheimer’s disease patients.
Collapse
Affiliation(s)
- Muhammad Ali
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA, 148532
| | - Kaja Falkenhain
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA, 148532
| | - Brendah N Njiru
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA, 148532
| | - Muhammad Murtaza-Ali
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA, 148532
| | - Nancy E Ruiz-Uribe
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA, 148532
| | | | | | - Nozomi Nishimura
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA, 148532
| | - Chris B Schaffer
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA, 148532
| | - Oliver Bracko
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA, 148532
| |
Collapse
|
3
|
Ruiz‐Uribe NE, Bracko O, Swallow M, Ali M, Njiru BN, Falkenhain K, Chang H, Iadecola C, Park L, Nishimura N, Schaffer CB. Neutrophil adhesion in brain capillaries contributes to cerebral blood flow deficits in APP/PS1 mice and is dependent on oxidative stress pathways. Alzheimers Dement 2020. [DOI: 10.1002/alz.043267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
4
|
Bracko O, Njiru BN, Swallow M, Ali M, Haft-Javaherian M, Schaffer CB. Increasing cerebral blood flow improves cognition into late stages in Alzheimer's disease mice. J Cereb Blood Flow Metab 2020; 40:1441-1452. [PMID: 31495298 PMCID: PMC7308509 DOI: 10.1177/0271678x19873658] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Alzheimer's disease is associated with a 20-30% reduction in cerebral blood flow. In the APP/PS1 mouse model of Alzheimer's disease, inhibiting neutrophil adhesion using an antibody against the neutrophil specific protein Ly6G was recently shown to drive rapid improvements in cerebral blood flow that was accompanied by an improvement in performance on short-term memory tasks. Here, in a longitudinal aging study, we assessed how far into disease development a single injection of anti-Ly6G treatment can acutely improve short-term memory function. We found that APP/PS1 mice as old as 15-16 months had improved performance on the object replacement and Y-maze tests of spatial and working short-term memory, measured at one day after anti-Ly6G treatment. APP/PS1 mice at 17-18 months of age or older did not show acute improvements in cognitive performance, although we did find that capillary stalls were still reduced and cerebral blood flow was still increased by 17% in 21-22-months-old APP/PS1 mice given anti-Ly6G antibody. These data add to the growing body of evidence suggesting that cerebral blood flow reductions are an important contributing factor to the cognitive dysfunction associated with neurodegenerative disease. Thus, interfering with neutrophil adhesion could be a new therapeutic approach for Alzheimer's disease.
Collapse
Affiliation(s)
- Oliver Bracko
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Brendah N Njiru
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Madisen Swallow
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Muhammad Ali
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Mohammad Haft-Javaherian
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Chris B Schaffer
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| |
Collapse
|
5
|
Bracko O, Vinarcsik LK, Cruz Hernández JC, Ruiz-Uribe NE, Haft-Javaherian M, Falkenhain K, Ramanauskaite EM, Ali M, Mohapatra A, Swallow MA, Njiru BN, Muse V, Michelucci PE, Nishimura N, Schaffer CB. High fat diet worsens Alzheimer's disease-related behavioral abnormalities and neuropathology in APP/PS1 mice, but not by synergistically decreasing cerebral blood flow. Sci Rep 2020; 10:9884. [PMID: 32555372 PMCID: PMC7303150 DOI: 10.1038/s41598-020-65908-y] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 05/07/2020] [Indexed: 12/18/2022] Open
Abstract
Obesity is linked to increased risk for and severity of Alzheimer's disease (AD). Cerebral blood flow (CBF) reductions are an early feature of AD and are also linked to obesity. We recently showed that non-flowing capillaries, caused by adhered neutrophils, contribute to CBF reduction in mouse models of AD. Because obesity could exacerbate the vascular inflammation likely underlying this neutrophil adhesion, we tested links between obesity and AD by feeding APP/PS1 mice a high fat diet (Hfd) and evaluating behavioral, physiological, and pathological changes. We found trends toward poorer memory performance in APP/PS1 mice fed a Hfd, impaired social interactions with either APP/PS1 genotype or a Hfd, and synergistic impairment of sensory-motor function in APP/PS1 mice fed a Hfd. The Hfd led to increases in amyloid-beta monomers and plaques in APP/PS1 mice, as well as increased brain inflammation. These results agree with previous reports showing obesity exacerbates AD-related pathology and symptoms in mice. We used a crowd-sourced, citizen science approach to analyze imaging data to determine the impact of the APP/PS1 genotype and a Hfd on capillary stalling and CBF. Surprisingly, we did not see an increase in the number of non-flowing capillaries or a worsening of the CBF deficit in APP/PS1 mice fed a Hfd as compared to controls, suggesting that capillary stalling is not a mechanistic link between a Hfd and increased severity of AD in mice. Reducing capillary stalling by blocking neutrophil adhesion improved CBF and short-term memory function in APP/PS1 mice, even when fed a Hfd.
Collapse
Affiliation(s)
- Oliver Bracko
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Lindsay K Vinarcsik
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | | | - Nancy E Ruiz-Uribe
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | | | - Kaja Falkenhain
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | | | - Muhammad Ali
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Aditi Mohapatra
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Madisen A Swallow
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Brendah N Njiru
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Victorine Muse
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | | | - Nozomi Nishimura
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Chris B Schaffer
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA.
| |
Collapse
|
6
|
Bracko O, Cruz Hernandez JC, Njiru BN, Swallow M, Zheng J, Ali M, Kersbergen C, Muse V, Haft-Javaherian M, Park L, Vinarcsik LK, Ivasyk I, Kang Y, Zhou J, Otte G, Beverly JD, Slack E, Iadecola C, Nishimura N, Schaffer CB. O2‐12‐04: STALLED BLOOD FLOW IN BRAIN CAPILLARIES IS RESPONSIBLE FOR REDUCED CORTICAL PERFUSION AND IMPACTS COGNITIVE FUNCTION IN MOUSE MODELS OF ALZHEIMER'S DISEASE. Alzheimers Dement 2018. [DOI: 10.1016/j.jalz.2018.06.2709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
7
|
Impoinvil DE, Kongere JO, Foster WA, Njiru BN, Killeen GF, Githure JI, Beier JC, Hassanali A, Knols BGJ. Feeding and survival of the malaria vector Anopheles gambiae on plants growing in Kenya. Med Vet Entomol 2004; 18:108-115. [PMID: 15189235 DOI: 10.1111/j.0269-283x.2004.00484.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The propensity of the malaria vector mosquito Anopheles gambiae Giles (Diptera: Culicidae) to ingest sugars from various plants, and subsequent survival rates, were assessed with laboratory-reared males and females offered eight species of plants commonly cultivated and/or growing wild in western Kenya. In cages (no-choice bioassay), mosquitoes given the opportunity to feed on castorbean (Ricinus communis L.) had the longest survival times (mean and median survival time of 6.99 +/- 0.23 and 5.67 +/- 0.17 days, respectively), comparable to mosquitoes given 6% glucose (mean and median survival time of 8.70 +/- 0.23 and 6.67 +/- 0.33 days, respectively). Survival rates of An. gambiae were low on the other plants, comparable to mosquitoes given only water. Three plants: sweet potato (Ipomoea batatas L.), wild sage (Lantana camara L.) and castorbean provided levels of sugar ingestion by both sexes of An. gambiae detectable using the cold anthrone method, showing a positive correlation between median survival and sugar consumption (Spearman rank correlation coefficient = 0.905, P < 0.0001). Equal numbers of males and females were released in an enclosed semi-field screenhouse system containing a range of local plants, but no host for blood, and allowed to feed ad libitum: 6.7 +/- 0.5% (11/64) of those recaptured were found to contain detectable fructose (all females). Common plants are clearly a viable source of nutrition for adult female An. gambiae, as well as males, and may constitute and important resource for this important malaria vector.
Collapse
Affiliation(s)
- D E Impoinvil
- Department of Tropical Medicine, School of Public Health and Tropical Medicine, Tulane University Health Sciences Centre, New Orleans, LA, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Okanda FM, Dao A, Njiru BN, Arija J, Akelo HA, Touré Y, Odulaja A, Beier JC, Githure JI, Yan G, Gouagna LC, Knols BGJ, Killeen GF. Behavioural determinants of gene flow in malaria vector populations: Anopheles gambiae males select large females as mates. Malar J 2002; 1:10. [PMID: 12296972 PMCID: PMC140138 DOI: 10.1186/1475-2875-1-10] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2002] [Accepted: 08/14/2002] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Plasmodium-refractory mosquitoes are being rapidly developed for malaria control but will only succeed if they can successfully compete for mates when released into the wild. Pre-copulatory behavioural traits maintain genetic population structure in wild mosquito populations and mating barriers have foiled previous attempts to control malaria vectors through sterile male release. METHODS Varying numbers of virgin male and female Anopheles gambiae Giles, from two strains of different innate sizes, were allowed to mate under standardized conditions in laboratory cages, following which, the insemination status, oviposition success and egg batch size of each female was assessed. The influence of male and female numbers, strain combination and female size were determined using logistic regression, correlation analysis and a simple mechanistic model of male competition for females. RESULTS Male An. gambiae select females on the basis of size because of much greater fecundity among large females. Even under conditions where large numbers of males must compete for a smaller number of females, the largest females are more likely to become inseminated, to successfully oviposit and to produce large egg batches. CONCLUSIONS Sexual selection, on the basis of size, could either promote or limit the spread of malaria-refractory genes into wild populations and needs to be considered in the continued development and eventual release of transgenic vectors. Fundamental studies of behavioural ecology in malaria vectors such as An. gambiae can have important implications for malaria control and should be prioritised for more extensive investigation in the future.
Collapse
Affiliation(s)
- FM Okanda
- International Centre of Insect Physiology and Ecology, PO Box 30772, Nairobi, Kenya
| | - A Dao
- Ecole Nationale de Medecine, Medical Research and Training Centre, University of Mali, Bamako, Mali
| | - BN Njiru
- International Centre of Insect Physiology and Ecology, PO Box 30772, Nairobi, Kenya
| | - J Arija
- International Centre of Insect Physiology and Ecology, PO Box 30772, Nairobi, Kenya
| | - HA Akelo
- International Centre of Insect Physiology and Ecology, PO Box 30772, Nairobi, Kenya
| | - Y Touré
- Ecole Nationale de Medecine, Medical Research and Training Centre, University of Mali, Bamako, Mali
| | - A Odulaja
- International Centre of Insect Physiology and Ecology, PO Box 30772, Nairobi, Kenya
| | - JC Beier
- Department of Tropical Medicine, School of Public Health and Tropical Medicine, Tulane University Health Sciences Centre, 1430 Tulane Avenue, New Orleans, Louisiana, 70112, USA
| | - JI Githure
- International Centre of Insect Physiology and Ecology, PO Box 30772, Nairobi, Kenya
| | - G Yan
- Department of Biological Science, 219 Hochsletter Hall, State University of New York, Buffalo, New York 14260, USA
| | - LC Gouagna
- International Centre of Insect Physiology and Ecology, PO Box 30772, Nairobi, Kenya
| | - BGJ Knols
- International Centre of Insect Physiology and Ecology, PO Box 30772, Nairobi, Kenya
- Laboratory of Entomology, Wageningen University Research Centre, PO Box 8031, 6700 EH, Wageningen, The Netherlands
| | - GF Killeen
- International Centre of Insect Physiology and Ecology, PO Box 30772, Nairobi, Kenya
- Department of Tropical Medicine, School of Public Health and Tropical Medicine, Tulane University Health Sciences Centre, 1430 Tulane Avenue, New Orleans, Louisiana, 70112, USA
- Department of Public Health and Epidemiology, Swiss Tropical Institute, Socinstrasse 57, PO Box CH-4002, Basel, Switzerland
| |
Collapse
|