Hyperglycemia induced the Alzheimer's proteins and promoted loss of synaptic proteins in advanced-age female Goto-Kakizaki (GK) rats

Hiranya Pintana; Nattayaporn Apaijai; Sasiwan Kerdphoo; Wasana Pratchayasakul; Jirapas Sripetchwandee; Panan Suntornsaratoon; Narattaphol Charoenphandhu; Nipon Chattipakorn; Siriporn C Chattipakorn

doi:10.1016/j.neulet.2017.06.041

Hyperglycemia induced the Alzheimer's proteins and promoted loss of synaptic proteins in advanced-age female Goto-Kakizaki (GK) rats

Neurosci Lett. 2017 Aug 10:655:41-45. doi: 10.1016/j.neulet.2017.06.041. Epub 2017 Jun 24.

Authors

Hiranya Pintana¹, Nattayaporn Apaijai², Sasiwan Kerdphoo², Wasana Pratchayasakul¹, Jirapas Sripetchwandee¹, Panan Suntornsaratoon³, Narattaphol Charoenphandhu⁴, Nipon Chattipakorn¹, Siriporn C Chattipakorn⁵

Affiliations

¹ Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200, Thailand; Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200, Thailand; Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, 50200, Thailand.
² Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200, Thailand; Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, 50200, Thailand.
³ Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok, 10400, Thailand; Department of Physiology, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand.
⁴ Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok, 10400, Thailand; Department of Physiology, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand; Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, 73170, Thailand.
⁵ Neurophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200, Thailand; Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Chiang Mai, 50200, Thailand; Department of Oral Biology and Diagnostic Sciences, Faculty of Dentistry, Chiang Mai University, Chiang Mai, 50200, Thailand. Electronic address: [email protected].

PMID: 28652187
DOI: 10.1016/j.neulet.2017.06.041

Abstract

Although both type 2 diabetes mellitus (T2DM) and aging are related with Alzheimer's disease (AD), the effects of aging on the Alzheimer's proteins and the synaptic markers in T2DM have not been investigated. This study, we hypothesized that T2DM rats with advanced-age, aggravates the reduction of synaptic proteins and an increase in the Alzheimer's protein markers. Goto-Kakizaki rats (GK) were used as a T2DM group and wild-type rats (WT) were used as a control group. Rats in each group were categorized by age into young-adult (7 months) and advanced-age rats (12.5 months). Blood was collected in all rats to determine plasma glucose and insulin levels. The brains were used for determining the level of Alzheimer's and synaptic proteins. Our data demonstrated that GK rats had a decreased body weight and increased blood glucose levels, compared to their age-matched WT. p-Tau was increased in both advanced-age WT and GK, compared to their young-adult rats. Moreover, amyloid-beta (Aβ) level was higher in advanced-age GK than their age-matched WT. The synaptic proteins were decreased in advanced-age GK, compared to young-adult GK rats. However, no difference in the level of Alzheimer's proteins and synaptic proteins in the brains of young-adult GK compared to age-matched WT was found. Our data suggested that aging contributes to the pathogenesis of AD and the reduction of synaptic proteins to greater extent in a diabetic than in a healthy condition.

Keywords: Advanced-age; Alzheimer’s protein; Goto-Kakizaki (GK) rat; Synaptic proteins; Type 2 diabetes mellitus (T2DM).

MeSH terms

Age Factors
Amyloid beta-Peptides / metabolism*
Animals
Brain / metabolism
Diabetes Mellitus, Type 2 / metabolism*
Disks Large Homolog 4 Protein / metabolism*
Female
Hyperglycemia / metabolism*
Phosphorylation
Rats
Synapses / metabolism
Synaptophysin / metabolism*
tau Proteins / metabolism*

Substances

Amyloid beta-Peptides
Disks Large Homolog 4 Protein
Dlg4 protein, rat
Synaptophysin
tau Proteins