scholarly journals Metabolic Stress Alters Antioxidant Systems, Suppresses the Adiponectin Receptor 1 and Induces Alzheimer’s Like Pathology in Mice Brain

Cells ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 249
Author(s):  
Jong Ryeal Hahm ◽  
Myeung Hoon Jo ◽  
Rahat Ullah ◽  
Min Woo Kim ◽  
Myeong Ok Kim

Oxidative stress and insulin resistance play major roles in numerous neurodegenerative diseases, including Alzheimer’s disease (AD). A high-fat diet induces obesity-associated oxidative stress, neuronal insulin resistance, microglial activation, and neuroinflammation, which are considered important risk factors for neurodegeneration. Obesity-related metabolic dysfunction is a risk factor for cognitive decline. The present study aimed to elucidate whether chronic consumption of a high-fat diet (HFD; 24 weeks) can induce insulin resistance, neuroinflammation, and amyloid beta (Aβ) deposition in mouse brains. Male C57BL/6N mice were used for a high-fat diet (HFD)-induced pre-clinical model of obesity. The protein expression levels were examined via Western blot, immunofluorescence, and the behavior analysis was performed using the Morris water maze test. To obtain metabolic parameters, insulin sensitivity and glucose tolerance tests were performed. We found that metabolic perturbations from the chronic consumption of HFD elevated neuronal oxidative stress and insulin resistance through adiponectin receptor (AdipoR1) suppression in HFD-fed mice. Similarly, our in vitro results also indicated that knockdown of AdipoR1 in the embryonic mouse hippocampal cell line mHippoE-14 leads to increased oxidative stress in neurons. In addition, HFD markedly increased neuroinflammatory markers’ glial activation in the cortex and hippocampus regions of HFD mouse brains. More importantly, we observed that AdipoR1 suppression increased the amyloidogenic pathway both in vivo and in vitro. Furthermore, deregulated synaptic proteins and behavioral deficits were observed in the HFD mouse brains. Taken together, our findings suggest that excessive consumption of an HFD has a profound impact on brain function, which involves the acceleration of cognitive impairment due to increased obesity-associated oxidative stress, insulin resistance, and neuroinflammation, which ultimately may cause early onset of Alzheimer’s pathology via the suppression of AdipoR1 signaling in the brain.

Antioxidants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 80
Author(s):  
Simona Terzo ◽  
Alessandro Attanzio ◽  
Pasquale Calvi ◽  
Flavia Mulè ◽  
Luisa Tesoriere ◽  
...  

Obesity-related dysmetabolic conditions are amongst the most common causes of death globally. Indicaxanthin, a bioavailable betalain pigment from Opuntia ficus-indica fruit, has been demonstrated to modulate redox-dependent signalling pathways, exerting significant anti-oxidative and anti-inflammatory effects in vitro and in vivo. In light of the strict interconnections between inflammation, oxidative stress and insulin resistance (IR), a nutritionally relevant dose of indicaxanthin has been evaluated in a high-fat diet (HFD) model of obesity-related IR. To this end, biochemical and histological analysis, oxidative stress and inflammation evaluations in liver and adipose tissue were carried out. Our results showed that indicaxanthin treatment significantly reduced body weight, daily food intake and visceral fat mass. Moreover, indicaxanthin administration induced remarkable, beneficial effects on HFD-induced glucose dysmetabolism, reducing fasting glycaemia and insulinaemia, improving glucose and insulin tolerance and restoring the HOMA index to physiological values. These effects were associated with a reduction in hepatic and adipose tissue oxidative stress and inflammation. A decrease in RONS, malondialdehyde and NO levels, in TNF-α, CCL-2 and F4-80 gene expression, in p65, p-JNK, COX-2 and i-NOS protein levels, in crown-like structures and hepatic inflammatory foci was, indeed, observed. The current findings encourage further clinical studies to confirm the effectiveness of indicaxanthin to prevent and treat obesity-related dysmetabolic conditions.


2021 ◽  
Vol 22 (7) ◽  
pp. 3746
Author(s):  
Ilaria Zuliani ◽  
Chiara Lanzillotta ◽  
Antonella Tramutola ◽  
Eugenio Barone ◽  
Marzia Perluigi ◽  
...  

The disturbance of protein O-GlcNAcylation is emerging as a possible link between altered brain metabolism and the progression of neurodegeneration. As observed in brains with Alzheimer’s disease (AD), flaws of the cerebral glucose uptake translate into reduced protein O-GlcNAcylation, which promote the formation of pathological hallmarks. A high-fat diet (HFD) is known to foster metabolic dysregulation and insulin resistance in the brain and such effects have been associated with the reduction of cognitive performances. Remarkably, a significant role in HFD-related cognitive decline might be played by aberrant protein O-GlcNAcylation by triggering the development of AD signature and mitochondrial impairment. Our data support the impairment of total protein O-GlcNAcylation profile both in the brain of mice subjected to a 6-week high-fat-diet (HFD) and in our in vitro transposition on SH-SY5Y cells. The reduction of protein O-GlcNAcylation was associated with the development of insulin resistance, induced by overfeeding (i.e., defective insulin signaling and reduced mitochondrial activity), which promoted the dysregulation of the hexosamine biosynthetic pathway (HBP) flux, through the AMPK-driven reduction of GFAT1 activation. Further, we observed that a HFD induced the selective impairment of O-GlcNAcylated-tau and of O-GlcNAcylated-Complex I subunit NDUFB8, thus resulting in tau toxicity and reduced respiratory chain functionality respectively, highlighting the involvement of this posttranslational modification in the neurodegenerative process.


2010 ◽  
Vol 299 (4) ◽  
pp. R1082-R1090 ◽  
Author(s):  
Jill K. Morris ◽  
Gregory L. Bomhoff ◽  
John A. Stanford ◽  
Paige C. Geiger

Despite numerous clinical studies supporting a link between type 2 diabetes (T2D) and Parkinson's disease (PD), the clinical literature remains equivocal. We, therefore, sought to address the relationship between insulin resistance and nigrostriatal dopamine (DA) in a preclinical animal model. High-fat feeding in rodents is an established model of insulin resistance, characterized by increased adiposity, systemic oxidative stress, and hyperglycemia. We subjected rats to a normal chow or high-fat diet for 5 wk before infusing 6-hydroxydopamine (6-OHDA) into the medial forebrain bundle. Our goal was to determine whether a high-fat diet and the resulting peripheral insulin resistance would exacerbate 6-OHDA-induced nigrostriatal DA depletion. Prior to 6-OHDA infusion, animals on the high-fat diet exhibited greater body weight, increased adiposity, and impaired glucose tolerance. Two weeks after 6-OHDA, locomotor activity was tested, and brain and muscle tissue was harvested. Locomotor activity did not differ between the groups nor did cholesterol levels or measures of muscle atrophy. High-fat-fed animals exhibited higher homeostatic model assessment of insulin resistance (HOMA-IR) values and attenuated insulin-stimulated glucose uptake in fast-twitch muscle, indicating decreased insulin sensitivity. Animals in the high-fat group also exhibited greater DA depletion in the substantia nigra and the striatum, which correlated with HOMA-IR and adiposity. Decreased phosphorylation of HSP27 and degradation of IκBα in the substantia nigra indicate increased tissue oxidative stress. These findings support the hypothesis that a diet high in fat and the resulting insulin resistance may lower the threshold for developing PD, at least following DA-specific toxin exposure.


2013 ◽  
Vol 41 (03) ◽  
pp. 487-502 ◽  
Author(s):  
Wei-Xi Cui ◽  
Jie Yang ◽  
Xiao-Qing Chen ◽  
Qian Mao ◽  
Xiang-Lan Wei ◽  
...  

Non-alcoholic fatty liver disease (NAFLD) has become a major challenge to the healthcare system. This study was designed to evaluate the effect of the triterpenoid-rich fraction (TF) from Ilex hainanensis Merr. on NAFLD. Male Sprague-Dawley (SD) rats were fed a normal diet (control) or high fat diet (NAFLD model). After four weeks, the high fat diet group was orally administrated TF (250 mg/kg) for another two weeks. High fat diet fed rats displayed hyperlipidemia and a decline in liver function compared with control. However, administration with TF could effectively improve these symptoms, as demonstrated by decreasing the plasma levels of triglyceride (p <0.05), total cholesterol (p < 0.01), low-density lipoprotein cholesterol (p < 0.05), alanine transaminase (p < 0.05), aspartate aminotransferase (p < 0.01), liver index (p < 0.05) and insulin resistance index (p < 0.05) while increasing the high-density lipoprotein cholesterol (p < 0.05). Meanwhile, histopathological examination of livers also showed that TF could reduce the incidence of liver lesions induced by high fat diet. Furthermore, TF could alleviate oxidative stress and inflammation status indicated by the decline malondialdehyde and superoxide dismutase levels (p < 0.01, both) and levels of interleukin 6 and tumor necrosis factor-α (p < 0.05). In addition, immunohistochemistry showed TF evidently elevated the peroxisome proliferator-activated receptor (PPARα) expression (p < 0.01), while it diminished the Cytochrome P450 2E1 (CYP2E1) expression (p < 0.01) in liver. These results demonstrate that TF has potential ability to protect liver against NAFLD by regulating lipids metabolism and alleviating insulin resistance, inflammation and oxidative stress. This effect might be associated with regulating PPARα and CYP2E1 expression.


2020 ◽  
Author(s):  
Xiaoling Wu ◽  
Xinyu Zou ◽  
Mi Zhang ◽  
Haiqiang Hu ◽  
Xueliang Wei ◽  
...  

Abstract Background: Osteocalcin (OCN), as an energy-regulating hormone, involves in preventing nonalcoholic steatohepatitis. Laying hens have been used as an animal model for investigating liver function and related metabolic disordersas that the synthesis of fat in laying hens is much faster than in mammals with limited adipose tissue. The aim of this study was to investigate the effects of OCN on fatty liver hemorrhagic syndrome (FLHS) in aged laying hens. Methods: Thirty 68-week-old White Plymouth laying hens were randomly assigned into conventional single-bird cages, and the cages were randomly allocated into one of three treatments: normal diet (ND + vehicle , ND+V), high-fat diet (HFD + vehicle, HFD+V), and HFD + OCN (3 μg/bird, 1 time/2 days, i.m.) for 40 days. At experimental day 30, oral glucose tolerance tests (OGTT) and insulin tolerance tests (ITT) were performed. At the end of experiment, the hens were euthanized followed blood collection. The plasma aspartate transaminase (AST), alkaline phosphatase (ALP), total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) were measured using an automatic biochemistry analyzer. Pathological changes in the liver were examined under both light and transmission electron microscopes. The plasma inflammatory factors including interleukin-1 (IL-1), IL-6, and tumor Necrosis Factor-alpha (TNF-α) were analyzed by ELISA, and the gene expressions of these inflammatory factors in the liver were analyzed by Real-time PCR. And oxidative stress was evaluated using Malondialdehyde (MDA) and Glutathione peroxidase (GSH-Px) assay kits. Results: The results showed HFD hens had more severe liver haemorrhage and fibrosis than ND hens. The ultra-microstructural examination showed that hepatocytes of HFD hens appeared necrotic pyknosis associated with great intracellular electron, mitochondrial swelling, shrunk nucleus and absence of autolysosomes. OCN mitigated these pathological changes by improved HFD hens’ insulin resistance via alleviating the glucose intolerence and improving insulin sensitivity; inhibited HFD-induced oxidative stress as evidenced by decreased liver concentrations of MDA but increased GSH-Px; and reduced the inflammatory reaction with reducing blood IL-6 and TNF-α concentrations and mRNA expressions. Conclusion: These results suggest a high-fat diet promotes the FLHS development in aged hens, while OCN prevents the FLHS process through inhibiting insulin resistance, inflammatory reaction, oxidative stress and fibrosis, and acting autophagy.


2019 ◽  
Vol 317 (6) ◽  
pp. C1172-C1182 ◽  
Author(s):  
Min-Gyeong Shin ◽  
Hye-Na Cha ◽  
Soyoung Park ◽  
Yong-Woon Kim ◽  
Jong-Yeon Kim ◽  
...  

Selenoprotein W (SelW) is a selenium-containing protein with a redox motif found abundantly in the skeletal muscle of rodents. Previous in vitro studies suggest that SelW plays an antioxidant role; however, relatively few in vivo studies have addressed the antioxidant role of SelW. Since oxidative stress is a causative factor for the development of insulin resistance in obese subjects, we hypothesized that if SelW plays a role as an antioxidant, SelW deficiency could aggravate the oxidative stress and insulin resistance caused by a high-fat diet. SelW deficiency did not affect insulin sensitivity and H2O2 levels in the skeletal muscle of control diet-fed mice. SelW levels in the skeletal muscle were decreased by high-fat diet feeding for 12 wk. High-fat diet induced obesity and insulin resistance and increased the levels of H2O2 and oxidative stress makers, which were not affected by SelW deficiency. High-fat diet feeding increased the expression of antioxidant enzymes; however, SelW deficiency did not affect the expression levels of antioxidants. These results suggest that SelW does not play a protective role against oxidative stress and insulin resistance in the skeletal muscle of high-fat diet-fed obese mice.


2018 ◽  
Vol 41 (1) ◽  
pp. 92-98 ◽  
Author(s):  
Koichi Murano ◽  
Hirofumi Ogino ◽  
Tomofumi Okuno ◽  
Tomohiro Arakawa ◽  
Hitoshi Ueno

Sign in / Sign up

Export Citation Format

Share Document