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Strope TA, Wilkins HM. The reciprocal relationship between amyloid precursor protein and mitochondrial function. J Neurochem 2024. [PMID: 39022868 DOI: 10.1111/jnc.16183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2024] [Revised: 06/10/2024] [Accepted: 07/03/2024] [Indexed: 07/20/2024]
Abstract
Amyloid precursor protein (APP), secretase enzymes, and amyloid beta (Aβ) have been extensively studied in the context of Alzheimer's disease (AD). Despite this, the function of these proteins and their metabolism is not understood. APP, secretase enzymes, and APP processing products (Aβ and C-terminal fragments) localize to endosomes, mitochondria, endoplasmic reticulum (ER), and mitochondrial/ER contact sites. Studies implicate significant relationships between APP, secretase enzyme function, APP metabolism, and mitochondrial function. Mitochondrial dysfunction is a key pathological hallmark of AD and is intricately linked to proteostasis. Here, we review studies examining potential functions of APP, secretase enzymes, and APP metabolites in the context of mitochondrial function and bioenergetics. We discuss implications and limitations of studies and highlight knowledge gaps that remain in the field.
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Affiliation(s)
- Taylor A Strope
- University of Kansas Alzheimer's Disease Research Center, Kansas City, Kansas, USA
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Heather M Wilkins
- University of Kansas Alzheimer's Disease Research Center, Kansas City, Kansas, USA
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas, USA
- Department of Neurology, University of Kansas Medical Center, Kansas City, Kansas, USA
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2
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Franklin ZJ, Croce L, Dekeryte R, Delibegovic M, Platt B. BACE cleavage of APP does not drive the diabetic phenotype of PLB4 mice. Neurobiol Dis 2023; 182:106142. [PMID: 37137417 DOI: 10.1016/j.nbd.2023.106142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 04/26/2023] [Accepted: 04/29/2023] [Indexed: 05/05/2023] Open
Abstract
BACKGROUND Alzheimer's Disease (AD) and Type 2 Diabetes Mellitus (T2DM), two prevalent diseases related to ageing, often share common pathologies including increased inflammation, endoplasmic reticulum (ER) stress, and impaired metabolic homeostasis predominantly affecting different organs. Therefore, it was unexpected to find in a previous study that neuronal hBACE1 knock-in (PLB4 mouse) leads to both an AD- and T2DM- like phenotype. The complexity of this co-morbidity phenotype required a deeper systems approach to explore the age-related changes in AD and T2DM-like pathologies of the PLB4 mouse. Therefore, we here analysed key neuronal and metabolic tissues comparing associated pathologies to those of normal ageing. METHODS Glucose tolerance, insulin sensitivity and protein turnover were assessed in 5-h fasted 3- and 8-month-old male PLB4 and wild-type mice. Western Blot and quantitative PCR were performed to determine regulation of homeostatic and metabolic pathways in insulin-stimulated brain, liver and muscle tissue. RESULTS Neuronal hBACE1 expression caused early pathological cleavage of APP (increased monomeric Aβ (mAβ) levels at 3-months), in parallel with brain ER stress (increased phosphorylation of the translation regulation factor (p-eIF2α) and the chaperone binding immunoglobulin protein (BIP)). However, APP processing shifted over time (higher full-length APP and sAPPβ levels, alongside lower mAβ and secreted APPα at 8 months), along with increased ER stress (phosphorylated/total inositol-requiring enzyme 1α (IRE1α)) in brain and liver. Metabolically, systemic glucose intolerance was evident from 3 months, yet metabolic signalling varied greatly between tissues and ages, and was confined to the periphery (muscle insulin receptors (IR), dipeptidyl-peptidase-4 (DPP4) levels, and decreased phosphorylated protein Kinase B (p-Akt), alongside increased liver DPP4 and fibroblast growth factor 21 (FGF21)), all of which normalised to wild-type levels at 8 months. CONCLUSION Our data suggest that the murine nervous system is affected early by APP misprocessing as a result of hBACE1 introduction, which coincided with ER stress, but not IR changes, and was alleviated with age. Peripheral metabolic alterations occurred early and revealed tissue-specific (liver vs. muscle) adaptations in metabolic markers but did not correlate with neuronal APP processing. Compensatory vs. contributory neuronal mechanisms associated with hBACE1 expression at different ages may explain why mice intrinsically do not develop AD pathologies and may offer new insights for future interventions.
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Affiliation(s)
- Z J Franklin
- Institute of Medical Sciences, School of Medicine, Medical Sciences & Nutrition, Foresterhill, University of Aberdeen, Aberdeen AB25 2ZD, Scotland, UK
| | - L Croce
- Institute of Medical Sciences, School of Medicine, Medical Sciences & Nutrition, Foresterhill, University of Aberdeen, Aberdeen AB25 2ZD, Scotland, UK
| | - R Dekeryte
- Institute of Medical Sciences, School of Medicine, Medical Sciences & Nutrition, Foresterhill, University of Aberdeen, Aberdeen AB25 2ZD, Scotland, UK
| | - M Delibegovic
- Institute of Medical Sciences, School of Medicine, Medical Sciences & Nutrition, Foresterhill, University of Aberdeen, Aberdeen AB25 2ZD, Scotland, UK
| | - B Platt
- Institute of Medical Sciences, School of Medicine, Medical Sciences & Nutrition, Foresterhill, University of Aberdeen, Aberdeen AB25 2ZD, Scotland, UK.
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Wilkins HM. Interactions between amyloid, amyloid precursor protein, and mitochondria. Biochem Soc Trans 2023; 51:173-182. [PMID: 36688439 PMCID: PMC9987971 DOI: 10.1042/bst20220518] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 01/10/2023] [Accepted: 01/12/2023] [Indexed: 01/24/2023]
Abstract
Mitochondrial dysfunction and Aβ accumulation are hallmarks of Alzheimer's disease (AD). Decades of research describe a relationship between mitochondrial function and Aβ production. Amyloid precursor protein (APP), of which Aβ is generated from, is found within mitochondria. Studies suggest Aβ can be generated in mitochondria and imported into mitochondria. APP and Aβ alter mitochondrial function, while mitochondrial function alters Aβ production from APP. The role these interactions contribute to AD pathology and progression are unknown. Here, we discuss prior research, the rigor of those studies, and the critical knowledge gaps of relationships between APP, Aβ, and mitochondria.
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Affiliation(s)
- Heather M. Wilkins
- University of Kansas Alzheimer's Disease Center, Kansas City, KS, U.S.A
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, U.S.A
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, U.S.A
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Taylor HA, Przemylska L, Clavane EM, Meakin PJ. BACE1: More than just a β-secretase. Obes Rev 2022; 23:e13430. [PMID: 35119166 PMCID: PMC9286785 DOI: 10.1111/obr.13430] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 01/04/2022] [Accepted: 01/16/2022] [Indexed: 02/06/2023]
Abstract
β-site amyloid precursor protein cleaving enzyme-1 (BACE1) research has historically focused on its actions as the β-secretase responsible for the production of β-amyloid beta, observed in Alzheimer's disease. Although the greatest expression of BACE1 is found in the brain, BACE1 mRNA and protein is also found in many cell types including pancreatic β-cells, adipocytes, hepatocytes, and vascular cells. Pathologically elevated BACE1 expression in these cells has been implicated in the development of metabolic diseases, including type 2 diabetes, obesity, and cardiovascular disease. In this review, we examine key questions surrounding the BACE1 literature, including how is BACE1 regulated and how dysregulation may occur in disease, and understand how BACE1 regulates metabolism via cleavage of a myriad of substrates. The phenotype of the BACE1 knockout mice models, including reduced weight gain, increased energy expenditure, and enhanced leptin signaling, proposes a physiological role of BACE1 in regulating energy metabolism and homeostasis. Taken together with the weight loss observed with BACE1 inhibitors in clinical trials, these data highlight a novel role for BACE1 in regulation of metabolic physiology. Finally, this review aims to examine the possibility that BACE1 inhibitors could provide a innovative treatment for obesity and its comorbidities.
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Affiliation(s)
- Hannah A Taylor
- Discovery & Translational Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - Lena Przemylska
- Discovery & Translational Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - Eva M Clavane
- Discovery & Translational Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - Paul J Meakin
- Discovery & Translational Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
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Taylor MK, Sullivan DK, Keller JE, Burns JM, Swerdlow RH. Potential for Ketotherapies as Amyloid-Regulating Treatment in Individuals at Risk for Alzheimer’s Disease. Front Neurosci 2022; 16:899612. [PMID: 35784855 PMCID: PMC9243383 DOI: 10.3389/fnins.2022.899612] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 05/30/2022] [Indexed: 12/27/2022] Open
Abstract
Alzheimer’s disease (AD) is a progressive neurodegenerative condition characterized by clinical decline in memory and other cognitive functions. A classic AD neuropathological hallmark includes the accumulation of amyloid-β (Aβ) plaques, which may precede onset of clinical symptoms by over a decade. Efforts to prevent or treat AD frequently emphasize decreasing Aβ through various mechanisms, but such approaches have yet to establish compelling interventions. It is still not understood exactly why Aβ accumulates in AD, but it is hypothesized that Aβ and other downstream pathological events are a result of impaired bioenergetics, which can also manifest prior to cognitive decline. Evidence suggests that individuals with AD and at high risk for AD have functional brain ketone metabolism and ketotherapies (KTs), dietary approaches that produce ketone bodies for energy metabolism, may affect AD pathology by targeting impaired brain bioenergetics. Cognitively normal individuals with elevated brain Aβ, deemed “preclinical AD,” and older adults with peripheral metabolic impairments are ideal candidates to test whether KTs modulate AD biology as they have impaired mitochondrial function, perturbed brain glucose metabolism, and elevated risk for rapid Aβ accumulation and symptomatic AD. Here, we discuss the link between brain bioenergetics and Aβ, as well as the potential for KTs to influence AD risk and progression.
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Affiliation(s)
- Matthew K. Taylor
- Department of Dietetics and Nutrition, University of Kansas Medical Center, Kansas City, KS, United States
- University of Kansas Alzheimer’s Disease Research Center, Fairway, KS, United States
- *Correspondence: Matthew K. Taylor,
| | - Debra K. Sullivan
- Department of Dietetics and Nutrition, University of Kansas Medical Center, Kansas City, KS, United States
- University of Kansas Alzheimer’s Disease Research Center, Fairway, KS, United States
| | - Jessica E. Keller
- Department of Dietetics and Nutrition, University of Kansas Medical Center, Kansas City, KS, United States
| | - Jeffrey M. Burns
- University of Kansas Alzheimer’s Disease Research Center, Fairway, KS, United States
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, United States
| | - Russell H. Swerdlow
- University of Kansas Alzheimer’s Disease Research Center, Fairway, KS, United States
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, United States
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Fehsel K, Christl J. Comorbidity of osteoporosis and Alzheimer's disease: Is `AKT `-ing on cellular glucose uptake the missing link? Ageing Res Rev 2022; 76:101592. [PMID: 35192961 DOI: 10.1016/j.arr.2022.101592] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 02/14/2022] [Accepted: 02/16/2022] [Indexed: 02/08/2023]
Abstract
Osteoporosis and Alzheimer's disease (AD) are both degenerative diseases. Osteoporosis often proceeds cognitive deficits, and multiple studies have revealed common triggers that lead to energy deficits in brain and bone. Risk factors for osteoporosis and AD, such as obesity, type 2 diabetes, aging, chemotherapy, vitamin deficiency, alcohol abuse, and apolipoprotein Eε4 and/or Il-6 gene variants, reduce cellular glucose uptake, and protective factors, such as estrogen, insulin, exercise, mammalian target of rapamycin inhibitors, hydrogen sulfide, and most phytochemicals, increase uptake. Glucose uptake is a fine-tuned process that depends on an abundance of glucose transporters (Gluts) on the cell surface. Gluts are stored in vesicles under the plasma membrane, and protective factors cause these vesicles to fuse with the membrane, resulting in presentation of Gluts on the cell surface. This translocation depends mainly on AKT kinase signaling and can be affected by a range of factors. Reduced AKT kinase signaling results in intracellular glucose deprivation, which causes endoplasmic reticulum stress and iron depletion, leading to activation of HIF-1α, the transcription factor necessary for higher Glut expression. The link between diseases and aging is a topic of growing interest. Here, we show that diseases that affect the same biochemical pathways tend to co-occur, which may explain why osteoporosis and/or diabetes are often associated with AD.
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Honea RA, John CS, Green ZD, Kueck PJ, Taylor MK, Lepping RJ, Townley R, Vidoni ED, Burns JM, Morris JK. Relationship of fasting glucose and longitudinal Alzheimer's disease imaging markers. ALZHEIMER'S & DEMENTIA (NEW YORK, N. Y.) 2022; 8:e12239. [PMID: 35128029 PMCID: PMC8804928 DOI: 10.1002/trc2.12239] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 11/30/2021] [Accepted: 12/15/2021] [Indexed: 12/16/2022]
Abstract
INTRODUCTION Fasting glucose increases with age and is linked to modifiable Alzheimer's disease risk factors such as cardiovascular disease and Type 2 diabetes (T2D). METHODS We leveraged available biospecimens and neuroimaging measures collected during the Alzheimer's Prevention Through Exercise (APEx) trial (n = 105) to examine the longitudinal relationship between change in blood glucose metabolism and change in regional cerebral amyloid deposition and gray and white matter (WM) neurodegeneration in older adults over 1 year of follow-up. RESULTS Individuals with improving fasting glucose (n = 61) exhibited less atrophy and regional amyloid accumulation compared to those whose fasting glucose worsened over 1 year (n = 44). Specifically, while individuals with increasing fasting glucose did not yet show cognitive decline, they did have regional atrophy in the hippocampus and inferior parietal cortex, and increased amyloid accumulation in the precuneus cortex. Signs of early dementia pathology occurred in the absence of significant group differences in insulin or body composition, and was not modified by apolipoprotein E ε4 carrier status. DISCUSSION Dysregulation of glucose in late life may signal preclinical brain change prior to clinically relevant cognitive decline. Additional work is needed to determine whether treatments specifically targeting fasting glucose levels may impact change in brain structure or cerebral amyloid in older adults.
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Affiliation(s)
- Robyn A. Honea
- University of Kansas Alzheimer's Disease Research CenterKansas CityKansasUSA
- Department of NeurologyUniversity of Kansas Medical CenterKansas CityKansasUSA
| | - Casey S. John
- University of Kansas Alzheimer's Disease Research CenterKansas CityKansasUSA
- Department of NeurologyUniversity of Kansas Medical CenterKansas CityKansasUSA
| | - Zachary D. Green
- University of Kansas Alzheimer's Disease Research CenterKansas CityKansasUSA
- Department of NeurologyUniversity of Kansas Medical CenterKansas CityKansasUSA
| | - Paul J. Kueck
- University of Kansas Alzheimer's Disease Research CenterKansas CityKansasUSA
- Department of NeurologyUniversity of Kansas Medical CenterKansas CityKansasUSA
| | - Matthew K. Taylor
- Department of Dietetics and NutritionUniversity of Kansas Medical CenterKansas CityKansasUSA
| | - Rebecca J. Lepping
- Hoglund Biomedical Imaging CenterUniversity of Kansas Medical CenterKansas CityKansasUSA
| | - Ryan Townley
- University of Kansas Alzheimer's Disease Research CenterKansas CityKansasUSA
- Department of NeurologyUniversity of Kansas Medical CenterKansas CityKansasUSA
| | - Eric D. Vidoni
- University of Kansas Alzheimer's Disease Research CenterKansas CityKansasUSA
- Department of NeurologyUniversity of Kansas Medical CenterKansas CityKansasUSA
| | - Jeffery M. Burns
- University of Kansas Alzheimer's Disease Research CenterKansas CityKansasUSA
- Department of NeurologyUniversity of Kansas Medical CenterKansas CityKansasUSA
| | - Jill K. Morris
- University of Kansas Alzheimer's Disease Research CenterKansas CityKansasUSA
- Department of NeurologyUniversity of Kansas Medical CenterKansas CityKansasUSA
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Guo Y, Wang Q, Chen S, Xu C. Functions of amyloid precursor protein in metabolic diseases. Metabolism 2021; 115:154454. [PMID: 33248065 DOI: 10.1016/j.metabol.2020.154454] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 11/02/2020] [Accepted: 11/23/2020] [Indexed: 02/07/2023]
Abstract
Amyloid precursor protein (APP) is a transmembrane precursor protein that is widely expressed in the central nervous system and peripheral tissues in the liver and pancreas, adipose tissue, and myotubes. APP can be cleaved by proteases in two different ways to produce a variety of short peptides, each with different physiological properties and functions. APP peptides generated by non-amyloidogenic processing can positively influence metabolism, while the peptides produced by amyloidogenic processing have the opposite effects. Here, we summarize the regulatory effects of APP and its cleavage peptides on metabolism in the central nervous system and peripheral tissues. In addition, abnormal expression and function of APP and APP-derived peptides are associated with metabolic diseases, such as type 2 diabetes, obesity, non-alcoholic fatty liver disease, and cardiovascular disease, and cancers. Pharmacological intervention of APP function or reduction of the production of peptides derived from amyloidogenic processing may be effective strategies for the prevention and treatment of Alzheimer's disease, and they may also provide new guidance for the treatment of metabolic diseases.
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Affiliation(s)
- Yanjun Guo
- Department of Gastroenterology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China
| | - Qinqiu Wang
- Department of Gastroenterology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China
| | - Shenghui Chen
- Department of Gastroenterology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China
| | - Chengfu Xu
- Department of Gastroenterology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China.
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Kulas JA, Franklin WF, Smith NA, Manocha GD, Puig KL, Nagamoto-Combs K, Hendrix RD, Taglialatela G, Barger SW, Combs CK. Ablation of amyloid precursor protein increases insulin-degrading enzyme levels and activity in brain and peripheral tissues. Am J Physiol Endocrinol Metab 2019; 316:E106-E120. [PMID: 30422705 PMCID: PMC6417684 DOI: 10.1152/ajpendo.00279.2018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The amyloid precursor protein (APP) is a type I transmembrane glycoprotein widely studied for its role as the source of β-amyloid peptide, accumulation of which is causal in at least some cases of Alzheimer's disease (AD). APP is expressed ubiquitously and is involved in diverse biological processes. Growing bodies of evidence indicate connections between AD and somatic metabolic disorders related to type 2 diabetes, and App-/- mice show alterations in glycemic regulation. We find that App-/- mice have higher levels of insulin-degrading enzyme (IDE) mRNA, protein, and activity compared with wild-type controls. This regulation of IDE by APP was widespread across numerous tissues, including liver, skeletal muscle, and brain as well as cell types within neural tissue, including neurons, astrocytes, and microglia. RNA interference-mediated knockdown of APP in the SIM-A9 microglia cell line elevated IDE levels. Fasting levels of blood insulin were lower in App-/- than App+/+ mice, but the former showed a larger increase in response to glucose. These low basal levels may enhance peripheral insulin sensitivity, as App-/- mice failed to develop impairment of glucose tolerance on a high-fat, high-sucrose ("Western") diet. Insulin levels and insulin signaling were also lower in the App-/- brain; synaptosomes prepared from App-/- hippocampus showed diminished insulin receptor phosphorylation compared with App+/+ mice when stimulated ex vivo. These findings represent a new molecular link connecting APP to metabolic homeostasis and demonstrate a novel role for APP as an upstream regulator of IDE in vivo.
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Affiliation(s)
- Joshua A Kulas
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences , Grand Forks, North Dakota
| | - Whitney F Franklin
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch , Galveston, Texas
| | - Nicholas A Smith
- Department of Pathology, University of North Dakota School of Medicine and Health Sciences , Grand Forks, North Dakota
| | - Gunjan D Manocha
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences , Grand Forks, North Dakota
| | - Kendra L Puig
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences , Grand Forks, North Dakota
| | - Kumi Nagamoto-Combs
- Department of Pathology, University of North Dakota School of Medicine and Health Sciences , Grand Forks, North Dakota
| | - Rachel D Hendrix
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences , Little Rock Arkansas
| | - Giulio Taglialatela
- Department of Neurology, University of Texas Medical Branch , Galveston, Texas
| | - Steven W Barger
- Department of Geriatrics, University of Arkansas for Medical Sciences , Little Rock Arkansas
- Geriatric Research, Education and Clinical Center, Central Arkansas Veterans Healthcare System, Little Rock, Arkansas
| | - Colin K Combs
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences , Grand Forks, North Dakota
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Wang YB, Xie JQ, Liu W, Zhang RZ, Huang SH, Xing YH. BACE1 gene silencing alleviates isoflurane anesthesia‑induced postoperative cognitive dysfunction in immature rats by activating the PI3K/Akt signaling pathway. Mol Med Rep 2018; 18:4259-4270. [PMID: 30221701 PMCID: PMC6172366 DOI: 10.3892/mmr.2018.9453] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 08/01/2018] [Indexed: 12/29/2022] Open
Abstract
Postoperative cognitive dysfunction (POCD) is a severe complication characterized by cognitive dysfunction following anesthesia and surgery. The aim of the present study was to investigate the effects of β-site amyloid precursor protein cleavage enzyme 1 (BACE1) gene silencing on isoflurane anesthesia-induced POCD in immature rats via the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) signaling pathway. Rat models were established and then transfected with BACE1 small interfering RNA and wortmannin (an inhibitor of PI3K). Blood gas analysis was performed, and a series of behavioral experiments were conducted to evaluate the cognitive function, learning ability and locomotor activity of rats. Reverse transcription quantitative polymerase chain reaction and western blot analysis were employed to determine the mRNA and protein expression of the associated genes. An ELISA was used to detect the inflammatory indicators and the content of amyloid precursor protein (APP) and amyloid-β (Aβ). Apoptosis of the hippocampal CA1 region was observed by terminal deoxynucleotidyl transferase dUTP nick-end labeling staining. Initially, it was revealed that the percentage of stagnation time in rats was increased by BACE1 gene silencing; the escape latency and swimming distance were markedly reduced from the 4th to the 6th day, the time the rats spent in first passing the target area was shortened, and the times of passing the target area were increased by BACE1 gene silencing, demonstrating that BACE1 gene silencing enhanced the spatial memory ability of rats. Additionally, it was determined that silencing BACE1 improved the pathological state induced by isoflurane anesthesia in immature rats, and attenuated the inflammatory response and the levels of APP and Aβ in hippocampal tissues. Furthermore, it was suggested that silencing BACE1 may have promoted the activation of the PI3K/Akt signaling pathway, thereby inhibiting the apoptosis of the hippocampal CA1 region. Taken together, these results indicated that BACE1 gene silencing may improve isoflurane anesthesia-induced POCD in immature rats by activating the PI3K/Akt signaling pathway and inhibiting the Aβ generated by APP.
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Affiliation(s)
- Ying-Bin Wang
- Department of Anesthesiology, Lanzhou University Second Hospital, Lanzhou, Gansu 730030, P.R. China
| | - Jian-Qin Xie
- Department of Anesthesiology, Lanzhou University Second Hospital, Lanzhou, Gansu 730030, P.R. China
| | - Wei Liu
- Department of Anesthesiology, Lanzhou University Second Hospital, Lanzhou, Gansu 730030, P.R. China
| | - Rong-Zhi Zhang
- Department of Anesthesiology, Lanzhou University Second Hospital, Lanzhou, Gansu 730030, P.R. China
| | - Sheng-Hui Huang
- Department of Anesthesiology, Lanzhou University Second Hospital, Lanzhou, Gansu 730030, P.R. China
| | - Yan-Hong Xing
- Department of Anesthesiology, Lanzhou University Second Hospital, Lanzhou, Gansu 730030, P.R. China
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Botteri G, Salvadó L, Gumà A, Lee Hamilton D, Meakin PJ, Montagut G, Ashford MLJ, Ceperuelo-Mallafré V, Fernández-Veledo S, Vendrell J, Calderón-Dominguez M, Serra D, Herrero L, Pizarro J, Barroso E, Palomer X, Vázquez-Carrera M. The BACE1 product sAPPβ induces ER stress and inflammation and impairs insulin signaling. Metabolism 2018. [PMID: 29526536 DOI: 10.1016/j.metabol.2018.03.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE β-secretase/β-site amyloid precursor protein (APP)-cleaving enzyme 1 (BACE1) is a key enzyme involved in Alzheimer's disease that has recently been implicated in insulin-independent glucose uptake in myotubes. However, it is presently unknown whether BACE1 and the product of its activity, soluble APPβ (sAPPβ), contribute to lipid-induced inflammation and insulin resistance in skeletal muscle cells. MATERIALS/METHODS Studies were conducted in mouse C2C12 myotubes, skeletal muscle from Bace1-/-mice and mice treated with sAPPβ and adipose tissue and plasma from obese and type 2 diabetic patients. RESULTS We show that BACE1 inhibition or knockdown attenuates palmitate-induced endoplasmic reticulum (ER) stress, inflammation, and insulin resistance and prevents the reduction in Peroxisome Proliferator-Activated Receptor γ Co-activator 1α (PGC-1α) and fatty acid oxidation caused by palmitate in myotubes. The effects of palmitate on ER stress, inflammation, insulin resistance, PGC-1α down-regulation, and fatty acid oxidation were mimicked by soluble APPβ in vitro. BACE1 expression was increased in subcutaneous adipose tissue of obese and type 2 diabetic patients and this was accompanied by a decrease in PGC-1α mRNA levels and by an increase in sAPPβ plasma levels of obese type 2 diabetic patients compared to obese non-diabetic subjects. Acute sAPPβ administration to mice reduced PGC-1α levels and increased inflammation in skeletal muscle and decreased insulin sensitivity. CONCLUSIONS Collectively, these findings indicate that the BACE1 product sAPPβ is a key determinant in ER stress, inflammation and insulin resistance in skeletal muscle and gluconeogenesis in liver.
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Affiliation(s)
- Gaia Botteri
- Pharmacology Unit, Department of Pharmacology, Toxicology and Therapeutic Chemistry, Faculty of Pharmacy and Food Sciences, University of Barcelona, Spain; Institut de Biomedicina de la Universitat de Barcelona (IBUB), Spain; Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Barcelona, Spain; Institut de Recerca Sant Joan de Déu (IR-SJD), Esplugues de Llobregat, Barcelona, Spain
| | - Laia Salvadó
- Pharmacology Unit, Department of Pharmacology, Toxicology and Therapeutic Chemistry, Faculty of Pharmacy and Food Sciences, University of Barcelona, Spain; Institut de Biomedicina de la Universitat de Barcelona (IBUB), Spain; Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Barcelona, Spain; Institut de Recerca Sant Joan de Déu (IR-SJD), Esplugues de Llobregat, Barcelona, Spain
| | - Anna Gumà
- Institut de Biomedicina de la Universitat de Barcelona (IBUB), Spain; Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Barcelona, Spain; Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - D Lee Hamilton
- Division of Molecular and Clinical Medicine, School of Medicine, Ninewells Hospital & Medical School, University of Dundee, Dundee, UK
| | - Paul J Meakin
- Division of Molecular and Clinical Medicine, School of Medicine, Ninewells Hospital & Medical School, University of Dundee, Dundee, UK
| | - Gemma Montagut
- Division of Molecular and Clinical Medicine, School of Medicine, Ninewells Hospital & Medical School, University of Dundee, Dundee, UK
| | - Michael L J Ashford
- Division of Molecular and Clinical Medicine, School of Medicine, Ninewells Hospital & Medical School, University of Dundee, Dundee, UK
| | - Victoria Ceperuelo-Mallafré
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Barcelona, Spain; Hospital Universitari de Tarragona Joan XXIII, Institut d'Investigació Sanitària Pere Virgili, Universitat Rovira i Virgili, Tarragona, Spain
| | - Sonia Fernández-Veledo
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Barcelona, Spain; Hospital Universitari de Tarragona Joan XXIII, Institut d'Investigació Sanitària Pere Virgili, Universitat Rovira i Virgili, Tarragona, Spain
| | - Joan Vendrell
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Barcelona, Spain; Hospital Universitari de Tarragona Joan XXIII, Institut d'Investigació Sanitària Pere Virgili, Universitat Rovira i Virgili, Tarragona, Spain
| | - María Calderón-Dominguez
- Institut de Biomedicina de la Universitat de Barcelona (IBUB), Spain; Department of Biochemistry and Physiology, Faculty of Pharmacy and Food Sciences, University of Barcelona, Spain; Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición (CIBEROBN), Instituto de Salud Carlos III, Barcelona, Spain
| | - Dolors Serra
- Institut de Biomedicina de la Universitat de Barcelona (IBUB), Spain; Department of Biochemistry and Physiology, Faculty of Pharmacy and Food Sciences, University of Barcelona, Spain; Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición (CIBEROBN), Instituto de Salud Carlos III, Barcelona, Spain
| | - Laura Herrero
- Institut de Biomedicina de la Universitat de Barcelona (IBUB), Spain; Department of Biochemistry and Physiology, Faculty of Pharmacy and Food Sciences, University of Barcelona, Spain; Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición (CIBEROBN), Instituto de Salud Carlos III, Barcelona, Spain
| | - Javier Pizarro
- Pharmacology Unit, Department of Pharmacology, Toxicology and Therapeutic Chemistry, Faculty of Pharmacy and Food Sciences, University of Barcelona, Spain; Institut de Biomedicina de la Universitat de Barcelona (IBUB), Spain; Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Barcelona, Spain; Institut de Recerca Sant Joan de Déu (IR-SJD), Esplugues de Llobregat, Barcelona, Spain
| | - Emma Barroso
- Pharmacology Unit, Department of Pharmacology, Toxicology and Therapeutic Chemistry, Faculty of Pharmacy and Food Sciences, University of Barcelona, Spain; Institut de Biomedicina de la Universitat de Barcelona (IBUB), Spain; Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Barcelona, Spain; Institut de Recerca Sant Joan de Déu (IR-SJD), Esplugues de Llobregat, Barcelona, Spain
| | - Xavier Palomer
- Pharmacology Unit, Department of Pharmacology, Toxicology and Therapeutic Chemistry, Faculty of Pharmacy and Food Sciences, University of Barcelona, Spain; Institut de Biomedicina de la Universitat de Barcelona (IBUB), Spain; Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Barcelona, Spain; Institut de Recerca Sant Joan de Déu (IR-SJD), Esplugues de Llobregat, Barcelona, Spain
| | - Manuel Vázquez-Carrera
- Pharmacology Unit, Department of Pharmacology, Toxicology and Therapeutic Chemistry, Faculty of Pharmacy and Food Sciences, University of Barcelona, Spain; Institut de Biomedicina de la Universitat de Barcelona (IBUB), Spain; Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Barcelona, Spain; Institut de Recerca Sant Joan de Déu (IR-SJD), Esplugues de Llobregat, Barcelona, Spain.
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12
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Czeczor JK, Genders AJ, Aston-Mourney K, Connor T, Hall LG, Hasebe K, Ellis M, De Jong KA, Henstridge DC, Meikle PJ, Febbraio MA, Walder K, McGee SL. APP deficiency results in resistance to obesity but impairs glucose tolerance upon high fat feeding. J Endocrinol 2018; 237:311-322. [PMID: 29674342 DOI: 10.1530/joe-18-0051] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 04/19/2018] [Indexed: 12/22/2022]
Abstract
The amyloid precursor protein (APP) generates a number of peptides when processed through different cleavage mechanisms, including the amyloid beta peptide that is implicated in the development of Alzheimer's disease. It is well established that APP via its cleaved peptides regulates aspects of neuronal metabolism. Emerging evidence suggests that amyloidogenic processing of APP can lead to altered systemic metabolism, similar to that observed in metabolic disease states. In the present study, we investigated the effect of APP deficiency on obesity-induced alterations in systemic metabolism. Compared with WT littermates, APP-deficient mice were resistant to diet-induced obesity, which was linked to higher energy expenditure and lipid oxidation throughout the dark phase and was associated with increased spontaneous physical activity. Consistent with this lean phenotype, APP-deficient mice fed a high-fat diet (HFD) had normal insulin tolerance. However, despite normal insulin action, these mice were glucose intolerant, similar to WT mice fed a HFD. This was associated with reduced plasma insulin in the early phase of the glucose tolerance test. Analysis of the pancreas showed that APP was required to maintain normal islet and β-cell mass under high fat feeding conditions. These studies show that, in addition to regulating aspects of neuronal metabolism, APP is an important regulator of whole body energy expenditure and glucose homeostasis under high fat feeding conditions.
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Affiliation(s)
- Juliane K Czeczor
- Metabolic Research UnitSchool of Medicine and Centre for Molecular and Medical Research, Deakin University, Geelong, Victoria, Australia
| | - Amanda J Genders
- Metabolic Research UnitSchool of Medicine and Centre for Molecular and Medical Research, Deakin University, Geelong, Victoria, Australia
| | - Kathryn Aston-Mourney
- Metabolic Research UnitSchool of Medicine and Centre for Molecular and Medical Research, Deakin University, Geelong, Victoria, Australia
| | - Timothy Connor
- Metabolic Research UnitSchool of Medicine and Centre for Molecular and Medical Research, Deakin University, Geelong, Victoria, Australia
| | - Liam G Hall
- Metabolic Research UnitSchool of Medicine and Centre for Molecular and Medical Research, Deakin University, Geelong, Victoria, Australia
| | - Kyoko Hasebe
- Metabolic Research UnitSchool of Medicine and Centre for Molecular and Medical Research, Deakin University, Geelong, Victoria, Australia
| | - Megan Ellis
- Metabolic Research UnitSchool of Medicine and Centre for Molecular and Medical Research, Deakin University, Geelong, Victoria, Australia
| | - Kirstie A De Jong
- Metabolic Research UnitSchool of Medicine and Centre for Molecular and Medical Research, Deakin University, Geelong, Victoria, Australia
| | | | - Peter J Meikle
- Baker Heart and Diabetes InstituteMelbourne, Victoria, Australia
| | - Mark A Febbraio
- Division of Diabetes and MetabolismGarvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
| | - Ken Walder
- Metabolic Research UnitSchool of Medicine and Centre for Molecular and Medical Research, Deakin University, Geelong, Victoria, Australia
| | - Sean L McGee
- Metabolic Research UnitSchool of Medicine and Centre for Molecular and Medical Research, Deakin University, Geelong, Victoria, Australia
- Baker Heart and Diabetes InstituteMelbourne, Victoria, Australia
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13
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Meakin PJ, Jalicy SM, Montagut G, Allsop DJP, Cavellini DL, Irvine SW, McGinley C, Liddell MK, McNeilly AD, Parmionova K, Liu YR, Bailey CLS, Dale JK, Heisler LK, McCrimmon RJ, Ashford MLJ. Bace1-dependent amyloid processing regulates hypothalamic leptin sensitivity in obese mice. Sci Rep 2018; 8:55. [PMID: 29311632 PMCID: PMC5758523 DOI: 10.1038/s41598-017-18388-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 12/11/2017] [Indexed: 01/21/2023] Open
Abstract
Obesity places an enormous medical and economic burden on society. The principal driver appears to be central leptin resistance with hyperleptinemia. Accordingly, a compound that reverses or prevents leptin resistance should promote weight normalisation and improve glucose homeostasis. The protease Bace1 drives beta amyloid (Aβ) production with obesity elevating hypothalamic Bace1 activity and Aβ1–42 production. Pharmacological inhibition of Bace1 reduces body weight, improves glucose homeostasis and lowers plasma leptin in diet-induced obese (DIO) mice. These actions are not apparent in ob/ob or db/db mice, indicating the requirement for functional leptin signalling. Decreasing Bace1 activity normalises hypothalamic inflammation, lowers PTP1B and SOCS3 and restores hypothalamic leptin sensitivity and pSTAT3 response in obese mice, but does not affect leptin sensitivity in lean mice. Raising central Aβ1–42 levels in the early stage of DIO increases hypothalamic basal pSTAT3 and reduces the amplitude of the leptin pSTAT3 signal without increased inflammation. Thus, elevated Aβ1–42 promotes hypothalamic leptin resistance, which is associated with diminished whole-body sensitivity to exogenous leptin and exacerbated body weight gain in high fat fed mice. These results indicate that Bace1 inhibitors, currently in clinical trials for Alzheimer’s disease, may be useful agents for the treatment of obesity and associated diabetes.
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Affiliation(s)
- Paul J Meakin
- Division of Molecular and Clinical Medicine, School of Medicine, Ninewells Hospital & Medical School, Dundee, DD1 9SY, UK
| | - Susan M Jalicy
- Division of Molecular and Clinical Medicine, School of Medicine, Ninewells Hospital & Medical School, Dundee, DD1 9SY, UK
| | - Gemma Montagut
- Division of Molecular and Clinical Medicine, School of Medicine, Ninewells Hospital & Medical School, Dundee, DD1 9SY, UK
| | - David J P Allsop
- Division of Molecular and Clinical Medicine, School of Medicine, Ninewells Hospital & Medical School, Dundee, DD1 9SY, UK
| | - Daniella L Cavellini
- Division of Molecular and Clinical Medicine, School of Medicine, Ninewells Hospital & Medical School, Dundee, DD1 9SY, UK
| | - Stuart W Irvine
- Division of Molecular and Clinical Medicine, School of Medicine, Ninewells Hospital & Medical School, Dundee, DD1 9SY, UK
| | - Christopher McGinley
- Division of Molecular and Clinical Medicine, School of Medicine, Ninewells Hospital & Medical School, Dundee, DD1 9SY, UK
| | - Mary K Liddell
- Division of Molecular and Clinical Medicine, School of Medicine, Ninewells Hospital & Medical School, Dundee, DD1 9SY, UK
| | - Alison D McNeilly
- Division of Molecular and Clinical Medicine, School of Medicine, Ninewells Hospital & Medical School, Dundee, DD1 9SY, UK
| | - Karolina Parmionova
- Division of Molecular and Clinical Medicine, School of Medicine, Ninewells Hospital & Medical School, Dundee, DD1 9SY, UK
| | - Yu-Ru Liu
- School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | | | - J Kim Dale
- School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Lora K Heisler
- Rowett Institute of Nutrition and Health, Aberdeen, AB21 9SB, UK
| | - Rory J McCrimmon
- Division of Molecular and Clinical Medicine, School of Medicine, Ninewells Hospital & Medical School, Dundee, DD1 9SY, UK
| | - Michael L J Ashford
- Division of Molecular and Clinical Medicine, School of Medicine, Ninewells Hospital & Medical School, Dundee, DD1 9SY, UK.
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14
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Kulas JA, Puig KL, Combs CK. Amyloid precursor protein in pancreatic islets. J Endocrinol 2017; 235:49-67. [PMID: 28710249 PMCID: PMC6267436 DOI: 10.1530/joe-17-0122] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 07/13/2017] [Indexed: 01/04/2023]
Abstract
The amyloid precursor protein (APP) has been extensively investigated for its role in the production of amyloid beta (Aβ), a plaque-forming peptide in Alzheimer's disease (AD). Epidemiological evidence suggests type 2 diabetes is a risk factor for AD. The pancreas is an essential regulator of blood glucose levels through the secretion of the hormones insulin and glucagon. Pancreatic dysfunction is a well-characterized consequence of type 1 and type 2 diabetes. In this study, we have examined the expression and processing of pancreatic APP to test the hypothesis that APP may play a role in pancreatic function and the pathophysiology of diabetes. Our data demonstrate the presence of APP within the pancreas, including pancreatic islets in both mouse and human samples. Additionally, we report that the APP/PS1 mouse model of AD overexpresses APP within pancreatic islets, although this did not result in detectable levels of Aβ. We compared whole pancreas and islet culture lysates by Western blot from C57BL/6 (WT), APP-/- and APP/PS1 mice and observed APP-dependent differences in the total protein levels of GLUT4, IDE and BACE2. Immunohistochemistry for BACE2 detected high levels in pancreatic α cells. Additionally, both mouse and human islets processed APP to release sAPP into cell culture media. Moreover, sAPP stimulated insulin but not glucagon secretion from islet cultures. We conclude that APP and its metabolites are capable of influencing the basic physiology of the pancreas, possibly through the release of sAPP acting in an autocrine or paracrine manner.
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Affiliation(s)
- Joshua A Kulas
- Department of Biomedical SciencesUniversity of North Dakota School of Medicine and Health Sciences, Grand Forks, USA
| | - Kendra L Puig
- Department of Biomedical SciencesUniversity of North Dakota School of Medicine and Health Sciences, Grand Forks, USA
| | - Colin K Combs
- Department of Biomedical SciencesUniversity of North Dakota School of Medicine and Health Sciences, Grand Forks, USA
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15
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Czeczor JK, McGee SL. Emerging roles for the amyloid precursor protein and derived peptides in the regulation of cellular and systemic metabolism. J Neuroendocrinol 2017; 29. [PMID: 28349564 DOI: 10.1111/jne.12470] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 03/03/2017] [Accepted: 03/22/2017] [Indexed: 01/01/2023]
Abstract
The amyloid precursor protein (APP) is a transmembrane protein that can be cleaved by proteases through two different pathways to yield a number of small peptides, each with distinct physiological properties and functions. It has been extensively studied in the context of Alzheimer's disease, with the APP-derived amyloid β (Aβ) peptide being a major constituent of the amyloid plaques observed in this disease. It has been known for some time that APP can regulate neuronal metabolism; however, the present review examines the evidence indicating that APP and its peptides can also regulate key metabolic processes such as insulin action, lipid synthesis and storage and mitochondrial function in peripheral tissues. This review presents the hypothesis that amyloidogenic processing of APP in peripheral tissues plays a key role in the response to nutrient excess and that this could contribute to the pathogenesis of metabolic diseases such as obesity and type 2 diabetes (T2D).
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Affiliation(s)
- J K Czeczor
- Metabolic Research Unit, Metabolic Reprogramming Laboratory, School of Medicine and Centre for Molecular and Medical Research, Deakin University, Geelong, VIC, Australia
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Heinrich-Heine University, Düsseldorf, Germany
- German Center of Diabetes Research, München-Neuherberg, Germany
| | - S L McGee
- Metabolic Research Unit, Metabolic Reprogramming Laboratory, School of Medicine and Centre for Molecular and Medical Research, Deakin University, Geelong, VIC, Australia
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16
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Liu X, Du Y, Trakooljul N, Brand B, Muráni E, Krischek C, Wicke M, Schwerin M, Wimmers K, Ponsuksili S. Muscle Transcriptional Profile Based on Muscle Fiber, Mitochondrial Respiratory Activity, and Metabolic Enzymes. Int J Biol Sci 2015; 11:1348-62. [PMID: 26681915 PMCID: PMC4671993 DOI: 10.7150/ijbs.13132] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 09/07/2015] [Indexed: 12/11/2022] Open
Abstract
Skeletal muscle is a highly metabolically active tissue that both stores and consumes energy. Important biological pathways that affect energy metabolism and metabolic fiber type in muscle cells may be identified through transcriptomic profiling of the muscle, especially ante mortem. Here, gene expression was investigated in malignant hyperthermia syndrome (MHS)-negative Duroc and Pietrian (PiNN) pigs significantly differing for the muscle fiber types slow-twitch-oxidative fiber (STO) and fast-twitch-oxidative fiber (FTO) as well as mitochondrial activity (succinate-dependent state 3 respiration rate). Longissimus muscle samples were obtained 24 h before slaughter and profiled using cDNA microarrays. Differential gene expression between Duroc and PiNN muscle samples were associated with protein ubiquitination, stem cell pluripotency, amyloid processing, and 3-phosphoinositide biosynthesis and degradation pathways. In addition, weighted gene co-expression network analysis within both breeds identified several co-expression modules that were associated with the proportion of different fiber types, mitochondrial respiratory activity, and ATP metabolism. In particular, Duroc results revealed strong correlations between mitochondrion-associated co-expression modules and STO (r = 0.78), fast-twitch glycolytic fiber (r = -0.98), complex I (r=0.72) and COX activity (r = 0.86). Other pathways in the protein-kinase-activity enriched module were positively correlated with STO (r=0.93), while negatively correlated with FTO (r = -0.72). In contrast to PiNN, co-expression modules enriched in macromolecule catabolic process, actin cytoskeleton, and transcription activator activity were associated with fiber types, mitochondrial respiratory activity, and metabolic enzyme activities. Our results highlight the importance of mitochondria for the oxidative capacity of porcine muscle and for breed-dependent molecular pathways in muscle cell fibers.
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Affiliation(s)
- Xuan Liu
- 1. Leibniz Institute for Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, D-18196 Dummerstorf, Germany
| | - Yang Du
- 1. Leibniz Institute for Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, D-18196 Dummerstorf, Germany
| | - Nares Trakooljul
- 1. Leibniz Institute for Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, D-18196 Dummerstorf, Germany
| | - Bodo Brand
- 1. Leibniz Institute for Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, D-18196 Dummerstorf, Germany
| | - Eduard Muráni
- 1. Leibniz Institute for Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, D-18196 Dummerstorf, Germany
| | - Carsten Krischek
- 2. 2 Institute of Food Quality and Food Safety, University of Veterinary Medicine Hannover, D-30173 Hannover, Germany
| | - Michael Wicke
- 3. 3 Department of Animal Science, Quality of Food of Animal Origin, Georg-August-University Goettingen, D-37075 Goettingen, Germany
| | - Manfred Schwerin
- 1. Leibniz Institute for Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, D-18196 Dummerstorf, Germany
| | - Klaus Wimmers
- 1. Leibniz Institute for Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, D-18196 Dummerstorf, Germany
| | - Siriluck Ponsuksili
- 1. Leibniz Institute for Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, D-18196 Dummerstorf, Germany
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17
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Findlay JA, Hamilton DL, Ashford MLJ. BACE1 activity impairs neuronal glucose oxidation: rescue by beta-hydroxybutyrate and lipoic acid. Front Cell Neurosci 2015; 9:382. [PMID: 26483636 PMCID: PMC4589671 DOI: 10.3389/fncel.2015.00382] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 09/14/2015] [Indexed: 11/13/2022] Open
Abstract
Glucose hypometabolism and impaired mitochondrial function in neurons have been suggested to play early and perhaps causative roles in Alzheimer's disease (AD) pathogenesis. Activity of the aspartic acid protease, beta-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1), responsible for beta amyloid peptide generation, has recently been demonstrated to modify glucose metabolism. We therefore examined, using a human neuroblastoma (SH-SY5Y) cell line, whether increased BACE1 activity is responsible for a reduction in cellular glucose metabolism. Overexpression of active BACE1, but not a protease-dead mutant BACE1, protein in SH-SY5Y cells reduced glucose oxidation and the basal oxygen consumption rate, which was associated with a compensatory increase in glycolysis. Increased BACE1 activity had no effect on the mitochondrial electron transfer process but was found to diminish substrate delivery to the mitochondria by inhibition of key mitochondrial decarboxylation reaction enzymes. This BACE1 activity-dependent deficit in glucose oxidation was alleviated by the presence of beta hydroxybutyrate or α-lipoic acid. Consequently our data indicate that raised cellular BACE1 activity drives reduced glucose oxidation in a human neuronal cell line through impairments in the activity of specific tricarboxylic acid cycle enzymes. Because this bioenergetic deficit is recoverable by neutraceutical compounds we suggest that such agents, perhaps in conjunction with BACE1 inhibitors, may be an effective therapeutic strategy in the early-stage management or treatment of AD.
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Affiliation(s)
- John A Findlay
- Division of Cardiovascular and Diabetes Medicine, School of Medicine, Ninewells Hospital and Medical School, University of Dundee Dundee, UK
| | - David L Hamilton
- Division of Cardiovascular and Diabetes Medicine, School of Medicine, Ninewells Hospital and Medical School, University of Dundee Dundee, UK
| | - Michael L J Ashford
- Division of Cardiovascular and Diabetes Medicine, School of Medicine, Ninewells Hospital and Medical School, University of Dundee Dundee, UK
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