scholarly journals Insulin degrading enzyme contributes to the pathology in a mixed model of Type 2 diabetes and Alzheimer’s disease: possible mechanisms of IDE in T2D and AD

2018 ◽  
Vol 38 (1) ◽  
Author(s):  
Huajie Li ◽  
Jian Wu ◽  
Linfeng Zhu ◽  
Luolin Sha ◽  
Song Yang ◽  
...  

Insulin degrading enzyme (IDE) is believed to act as a junction point of Type 2 diabetes (T2D) and Alzheimer's disease (AD); however, the underlying mechanism was not completely clear yet. Transgenic APPSwe/PS1 mice were used as the AD model and were treated with streptozocin/streptozotocin (STZ) to develop a mixed mice model presenting both AD and T2D. Morris Water Maze (MWM) and recognition task were performed to trace the cognitive function. The detection of fasting plasma glucose (FPG) and plasma insulin concentration, and oral glucose tolerance test (OGTT) were used to trace the metabolism evolution. Aβ40 and Aβ42 were quantified by colorimetric ELISA kits. The mRNA or protein expression levels were determined by quantitative real-time RT-PCR and Western blotting analysis respectively. T2D contributes to the AD progress by accelerating and worsening spatial learning and recognition impairments. Metabolic parameters and glucose tolerance were significantly changed in the presence of the AD and T2D. The expression levels of IDE, PPARγ, and AMPK were down-regulated in mice with AD and T2D. PPARγ activator rosiglitazone (RSZ) or AMPK activator AICAR increased the expression level of IDE and decreased Aβ levels in mice with AD and T2D. RSZ or AICAR treatment also alleviated the spatial learning and recognition impairments in AD and T2D mice. Our results found that, in the mice with T2D and AD, the activators of PPARγ/AMPK signaling pathway significantly increased the expression level of IDE, and decreased the accumulation of Aβ40 and Aβ42, as well as alleviated the spatial learning and recognition impairments.

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Xin-Yi Lu ◽  
Shun Huang ◽  
Qu-Bo Chen ◽  
Dapeng Zhang ◽  
Wanyan Li ◽  
...  

Alzheimer’s disease (AD) is the most common neurodegenerative disease. The accumulation of amyloid beta (Aβ) is the main pathology of AD. Metformin, a well-known antidiabetic drug, has been reported to have AD-protective effect. However, the mechanism is still unclear. In this study, we tried to figure out whether metformin could activate insulin-degrading enzyme (IDE) to ameliorate Aβ-induced pathology. Morris water maze and Y-maze results indicated that metformin could improve the learning and memory ability in APPswe/PS1dE9 (APP/PS1) transgenic mice. 18F-FDG PET-CT result showed that metformin could ameliorate the neural dysfunction in APP/PS1 transgenic mice. PCR analysis showed that metformin could effectively improve the mRNA expression level of nerve and synapse-related genes (Syp, Ngf, and Bdnf) in the brain. Metformin decreased oxidative stress (malondialdehyde and superoxide dismutase) and neuroinflammation (IL-1β and IL-6) in APP/PS1 mice. In addition, metformin obviously reduced the Aβ level in the brain of APP/PS1 mice. Metformin did not affect the enzyme activities and mRNA expression levels of Aβ-related secretases (ADAM10, BACE1, and PS1). Meanwhile, metformin also did not affect the mRNA expression levels of Aβ-related transporters (LRP1 and RAGE). Metformin increased the protein levels of p-AMPK and IDE in the brain of APP/PS1 mice, which might be the key mechanism of metformin on AD. In conclusion, the well-known antidiabetic drug, metformin, could be a promising drug for AD treatment.


2018 ◽  
Vol 15 (7) ◽  
pp. 610-617 ◽  
Author(s):  
Huifeng Zhang ◽  
Dan Liu ◽  
Huanhuan Huang ◽  
Yujia Zhao ◽  
Hui Zhou

Background: β-amyloid (Aβ) accumulates abnormally to senile plaque which is the initiator of Alzheimer's disease (AD). As one of the Aβ-degrading enzymes, Insulin-degrading enzyme (IDE) remains controversial for its protein level and activity in Alzheimer's brain. Methods: The electronic databases PubMed, EMBASE, The Cochrane Library, OVID and Sinomed were systemically searched up to Sep. 20th, 2017. And the published case-control or cohort studies were retrieved to perform the meta-analysis. Results: Seven studies for IDE protein level (AD cases = 293; controls = 126), three for mRNA level (AD cases = 138; controls = 81), and three for enzyme activity (AD cases = 123; controls = 75) were pooling together. The IDE protein level was significantly lower in AD cases than in controls (SMD = - 0.47, 95% CI [-0.69, -0.24], p < 0.001), but IDE mRNA and enzyme activity had no significant difference (SMD = 0.02, 95% CI [-0.40, 0.43] and SMD = 0.06, 95% CI [-0.41, 0.53] respectively). Subgroup analyses found that IDE protein level was decreased in both cortex and hippocampus of AD cases (SMD = -0.43, 95% CI [-0.71, -0.16], p = 0.002 and SMD = -0.53, 95% CI [-0.91, -0.15], p = 0.006 respectively). However, IDE mRNA was higher in cortex of AD cases (SMD = 0.71, 95% CI [0.14, 1.29], p = 0.01), not in hippocampus (SMD = -0.26, 95% CI [-0.58, 0.06]). Conclusions: Our results indicate that AD patients may have lower IDE protease level. Further relevant studies are still needed to verify whether IDE is one of the factors affecting Aβ abnormal accumulation and throw new insights for AD detection or therapy.


2020 ◽  
Vol 16 ◽  
Author(s):  
Nataly Guzmán-Herrera ◽  
Viridiana C. Pérez-Nájera ◽  
Luis A. Salazar-Olivo

Background: Numerous studies have shown a significant association between type 2 diabetes mellitus (T2D) and Alzheimer's disease (AD), two pathologies affecting millions of people worldwide. Chronic inflammation and oxidative stress are two conditions common to these diseases also affecting the activity of the serpin alpha-1-antichymotrypsin (ACT), but a possible common role for this serpin in T2D and AD remains unclear. Objective: To explore the possible regulatory networks linking ACT to T2D and AD. Materials and Methods: A bibliographic search was carried out in PubMed, Med-line, Open-i, ScienceDirect, Scopus and SpringerLink for data indicating or suggesting association among T2D, AD, and ACT. Searched terms like “alpha-1-antichymotrypsin”, “type 2 diabetes”, “Alzheimer's disease”, “oxidative stress”, “pro-inflammatory mediators” among others were used. Moreover, common therapeutic strategies between T2D and AD as well as the use of ACT as a therapeutic target for both diseases were included. Results: ACT has been linked with development and maintenance of T2D and AD and studies suggest their participation through activation of inflammatory pathways and oxidative stress, mechanisms also associated with both diseases. Likewise, evidences indicate that diverse therapeutic approaches are common to both diseases. Conclusion: Inflammatory and oxidative stresses constitute a crossroad for T2D and AD where ACT could play an important role. In-depth research on ACT involvement in these two dysfunctions could generate new therapeutic strategies for T2D and AD.


Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1236
Author(s):  
Jesús Burillo ◽  
Patricia Marqués ◽  
Beatriz Jiménez ◽  
Carlos González-Blanco ◽  
Manuel Benito ◽  
...  

Type 2 diabetes mellitus is a progressive disease that is characterized by the appearance of insulin resistance. The term insulin resistance is very wide and could affect different proteins involved in insulin signaling, as well as other mechanisms. In this review, we have analyzed the main molecular mechanisms that could be involved in the connection between type 2 diabetes and neurodegeneration, in general, and more specifically with the appearance of Alzheimer’s disease. We have studied, in more detail, the different processes involved, such as inflammation, endoplasmic reticulum stress, autophagy, and mitochondrial dysfunction.


Author(s):  
Manel Ben Aissa ◽  
Cutler T. Lewandowski ◽  
Kiira M. Ratia ◽  
Sue H. Lee ◽  
Brian T. Layden ◽  
...  

2018 ◽  
Vol 56 (2) ◽  
pp. 833-843 ◽  
Author(s):  
Sudhanshu P. Raikwar ◽  
Sachin M. Bhagavan ◽  
Swathi Beladakere Ramaswamy ◽  
Ramasamy Thangavel ◽  
Iuliia Dubova ◽  
...  

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