scholarly journals Plant Sterol-Poor Diet Is Associated with Pro-Inflammatory Lipid Mediators in the Murine Brain

2021 ◽  
Vol 22 (24) ◽  
pp. 13207
Author(s):  
Madlen Reinicke ◽  
Judith Leyh ◽  
Silke Zimmermann ◽  
Soroth Chey ◽  
Ilijana Begcevic Brkovic ◽  
...  

Plant sterols (PSs) cannot be synthesized in mammals and are exclusively diet-derived. PSs cross the blood-brain barrier and may have anti-neuroinflammatory effects. Obesity is linked to lower intestinal uptake and blood levels of PSs, but its effects in terms of neuroinflammation—if any—remain unknown. We investigated the effect of high-fat diet-induced obesity on PSs in the brain and the effects of the PSs campesterol and β-sitosterol on in vitro microglia activation. Sterols (cholesterol, precursors, PSs) and polyunsaturated fatty acid-derived lipid mediators were measured in the food, blood, liver and brain of C57BL/6J mice. Under a PSs-poor high-fat diet, PSs levels decreased in the blood, liver and brain (>50%). This effect was reversible after 2 weeks upon changing back to a chow diet. Inflammatory thromboxane B2 and prostaglandin D2 were inversely correlated to campesterol and β-sitosterol levels in all brain regions. PSs content was determined post mortem in human cortex samples as well. In vitro, PSs accumulate in lipid rafts isolated from SIM-A9 microglia cell membranes. In summary, PSs levels in the blood, liver and brain were associated directly with PSs food content and inversely with BMI. PSs dampen pro-inflammatory lipid mediators in the brain. The identification of PSs in the human cortex in comparable concentration ranges implies the relevance of our findings for humans.

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.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Xiaoqing Ma ◽  
Wenhua Du ◽  
Shanshan Shao ◽  
Chunxiao Yu ◽  
Lingyan Zhou ◽  
...  

Purpose. We investigated whether a DDP-4 inhibitor, vildagliptin, alleviated ER stress induced by a high fat diet and improved hepatic lipid deposition. Methods. C57BL/6 mice received standard chow diet (CD), high fat diet (HFD), and HFD administered with vildagliptin (50 mg/Kg) (V-HFD). After administration for 12 weeks, serum alanine aminotransferase, glucose, cholesterol, triglyceride, and insulin levels were analyzed. Samples of liver underwent histological examination and transmission electron microscopy, real-time PCR for gene expression levels, and western blots for protein expression levels. ER stress was induced in HepG2 cells with palmitic acid and the effects of vildagliptin were investigated. Results. HFD mice showed increased liver weight/body weight (20.27%) and liver triglycerides (314.75%) compared to CD mice, but these decreased by 9.27% and 21.83%, respectively, in V-HFD mice. In the liver, HFD induced the expression of ER stress indicators significantly, which were obviously decreased by vildagliptin. In vitro, the expressions of molecular indicators of ER stress were reduced in HepG2 when vildagliptin was administered. Conclusions. Vildagliptin alleviates hepatic ER stress in a mouse high fat diet model. In HepG2 cells, vildagliptin directly reduced ER stress. Therefore, vildagliptin may be a potential agent for nonalcoholic fatty liver disease.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Wujie Cai ◽  
Lijing Yu ◽  
Yu Zhang ◽  
Li Feng ◽  
Siyuan Kong ◽  
...  

The aim of this study was to assay the effects ofCoreopsis tinctoriaNutt. flower extracts on hyperglycemia of diet-induced obese mice and the underlying mechanisms.Coreopsis tinctoriaflower was extracted with ethanol and water, respectively. The total phenol, flavonoid levels, and the constituents of the extracts were measured. For the animal experiments, C57BL/6 mice were fed with a chow diet, high-fat diet, or high-fat diet mixed with 0.4% (w/w) water and ethanol extracts ofCoreopsis tinctoriaflower for 8 weeks. The inhibitory effects of the extracts onα-glucosidase activity and the antioxidant properties were assayedin vitro. We found that the extracts blocked the increase of fasting blood glucose, serum triglyceride (TG), insulin, leptin, and liver lipid levels and prevented the development of glucose tolerance impairment and insulin resistance in the C57BL/6 mice induced by a high-fat diet. The extracts inhibitedα-glycosidase activity and increased oxidant activityin vitro. In conclusion,Coreopsis tinctoriaflower extracts may ameliorate high-fat diet-induced hyperglycemia and insulin resistance. The underling mechanism may be via the inhibition ofα-glucosidase activity. Our data indicate thatCoreopsis tinctoriaflower could be used as a beverage supplement and a potential source of drugs for treatment of diabetics.


Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Jingwei Jiang ◽  
Kamal Rahmouni

Virtually, every mammalian cell is equipped with an antenna like primary cilium, a cell surface protrusion that is thought to act as a sensory organelle. Many of the rare genetic disorders that cause shorter, absent or disrupted cilia are associated with obesity and cardiovascular dysfunction in humans and rodents, which suggest that cilia length contribute to energy balance and cardiovascular homeostasis. Here, we examined the length of the primary neuronal cilia in the brain nuclei that contribute to metabolic and cardiovascular regulation in high fat diet-induced obese (DIO) mice and DOCA-salt mice. Cilia length was examined by adenylate cyclase 3 (AC3) immunostaining, followed by confocal 3D reconstruction, and quantification by IMARIS imaging analysis software. Analysis of the cilia length and distribution showed reduced frequency of cilia that are over 10 μm in the brain of DIO mice compared to control mice fed normal diet fed mice (17.02±1.36% vs 23.78±1.15%, p=0.032). Interestingly, the most pronounced difference in cilia length was observed in the dorsomedial hypothalamus with the DIO mice displaying significantly shorter cilia (6.90±0.06 μm) relative to controls (7.32±0.14μm in controls, n=5/group p<0.05). Conversely, we found that average neuronal cilia length was elongated in 3-week DOCA-salt treated mice compared to sham group. The number of primary neuronal cilia that are over 10 μm was significantly increased in DOCA-salt mice by 8% (p=0.0114). On the other hand, the number of cilia that are 4-5 μm in length was significantly decreased in DOCA-salt mice compared to sham controls (11.73±1.70% vs 18.73±2.02%, p=0.0385). The supraoptic nucleus was the only nucleus that displayed difference in the length of cilia that are 5-10 μm in length (7.46±0.24 μm vs 6.76±0.15μm, n=5/group, p=0.0509). Our data demonstrate plasticity of neuronal cilia in response to high fat diet and DOCA-salt treatment in defined brain regions. Our results raise the possibility that primary neuronal cilia may function as part of environmental surveillance system in the brain that control energy homeostasis and cardiovascular function. Further analysis of the role of primary neuronal cilia in cardiovascular regulation is underway.


PLoS ONE ◽  
2022 ◽  
Vol 17 (1) ◽  
pp. e0262577
Author(s):  
Jin Tanaka ◽  
Fuka Ishikawa ◽  
Tomoki Jinno ◽  
Motoki Miyakita ◽  
Haruka Miyamori ◽  
...  

cAMP responsive element binding protein (CREB)-regulated transcription coactivators (CRTCs) regulate gene transcription in response to an increase in intracellular cAMP or Ca2+ levels. To date, three isoforms of CRTC have been identified in mammals. All CRTCs are widely expressed in various regions of the brain. Numerous studies have shown the importance of CREB and CRTC in energy homeostasis. In the brain, the paraventricular nucleus of the hypothalamus (PVH) plays a critical role in energy metabolism, and CRTC1 and CRTC2 are highly expressed in PVH neuronal cells. The single-minded homolog 1 gene (Sim1) is densely expressed in PVH neurons and in some areas of the amygdala neurons. To determine the role of CRTCs in PVH on energy metabolism, we generated mice that lacked CRTC1 and CRTC2 in Sim1 cells using Sim-1 cre mice. We found that Sim1 cell-specific CRTC1 and CRTC2 double-knockout mice were sensitive to high-fat diet (HFD)-induced obesity. Sim1 cell-specific CRTC1 and CRTC2 double knockout mice showed hyperphagia specifically for the HFD, but not for the normal chow diet, increased fat mass, and no change in energy expenditure. Interestingly, these phenotypes were stronger in female mice than in male mice, and a weak phenotype was observed in the normal chow diet. The lack of CRTC1 and CRTC2 in Sim1 cells changed the mRNA levels of some neuropeptides that regulate energy metabolism in female mice fed an HFD. Taken together, our findings suggest that CRTCs in Sim1 cells regulate gene expression and suppress excessive fat intake, especially in female mice.


2020 ◽  
Vol 244 (1) ◽  
pp. 149-162 ◽  
Author(s):  
Catalina Sierra-Ramos ◽  
Silvia Velazquez-Garcia ◽  
Arianna Vastola-Mascolo ◽  
Guadalberto Hernández ◽  
Nourdine Faresse ◽  
...  

The serum- and glucocorticoid-induced kinase 1 (SGK1) is a transcriptional target of steroid hormones including glucocorticoids or aldosterone in addition to other stimuli such as glucose. SGK1 is activated via phosphoinositide 3-kinase, placing it downstream of insulin signaling. SGK1 participates in the upregulation of kidney Na+ reabsorption by aldosterone and has been linked to obesity-related hypertension in humans. We hypothesized that a systemic increase in SGK1 activity may trigger a multiplicity of mechanisms leading to simultaneous development of the main conditions that characterize the metabolic syndrome (MetS), including hypertension. We used a transgenic mouse model made with a bacterial artificial chromosome containing the whole mouse Sgk1 gene modified to introduce an activating point mutation. Wild type or transgenic 14-week-old male mice were fed with standard chow diet or high-fat diet for up to 18 weeks. Development of the main features of MetS and hepatic steatosis were monitored, and in vitro adipocyte differentiation was studied. Our results show that transgenic animals under high-fat diet rapidly and markedly develop MetS characterized by obesity, glucose intolerance, insulin resistance, dyslipidemia and hypertension. In addition, SGK1 gain-of-function accelerates the development of hepatic steatosis. Our study suggests that inappropriate SGK1 activity represents a risk factor in developing MetS with hypertension and related end-organ damage. Our data support SGK1 as a possible therapeutic target in MetS and related complications and provides a useful gain-of-function model for pre-clinical drug testing.


2021 ◽  
pp. 153537022110060
Author(s):  
Yue Chen ◽  
Jie Ding ◽  
Yufei Zhao ◽  
Shenghong Ju ◽  
Hui Mao ◽  
...  

This study aimed to track and evaluate the effect of low-dose irisin on the browning of white adipose tissue (WAT) in mice using magnetic resonance imaging (MRI) noninvasively in vivo. Mature white adipocytes extracted from mice were cultured, induced and characterized before being treated by irisin. The volume and fat fraction of WAT were quantified using MRI in normal chow diet and high fat mice after injection of irisin. The browning of cultured white adipocytes and WAT in mice were validated by immunohistochemistry and western blotting for uncoupling protein 1 (UCP1) and deiodinase type II (DIO2). The serum indexes were examined with high fat diet after irisin intervention. UCP1 and DIO2 in adipocytes showed increases responding to the irisin treatment. The size of white adipocytes in mice receiving irisin intervention was reduced. MRI measured volumes and fat fraction of WAT were significantly lower after Irisin treatment. Blood glucose and cholesterol levels were reduced in high fat diet mice after irisin treatment. Irisin intervention exerted browning of WAT, resulting reduction of volume and fat fraction of WAT as measured by MRI. Furthermore, it improved the condition of mice with diet-induced obesity and related metabolic disorders.


2020 ◽  
Vol 11 (1) ◽  
pp. 147-160
Author(s):  
Ranyah Shaker M. Labban ◽  
Hanan Alfawaz ◽  
Ahmed T. Almnaizel ◽  
Wail M. Hassan ◽  
Ramesa Shafi Bhat ◽  
...  

AbstractObesity and the brain are linked since the brain can control the weight of the body through its neurotransmitters. The aim of the present study was to investigate the effect of high-fat diet (HFD)-induced obesity on brain functioning through the measurement of brain glutamate, dopamine, and serotonin metabolic pools. In the present study, two groups of rats served as subjects. Group 1 was fed a normal diet and named as the lean group. Group 2 was fed an HFD for 4 weeks and named as the obese group. Markers of oxidative stress (malondialdehyde, glutathione, glutathione-s-transferase, and vitamin C), inflammatory cytokines (interleukin [IL]-6 and IL-12), and leptin along with a lipid profile (cholesterol, triglycerides, high-density lipoprotein, and low-density lipoprotein levels) were measured in the serum. Neurotransmitters dopamine, serotonin, and glutamate were measured in brain tissue. Fecal samples were collected for observing changes in gut flora. In brain tissue, significantly high levels of dopamine and glutamate as well as significantly low levels of serotonin were found in the obese group compared to those in the lean group (P > 0.001) and were discussed in relation to the biochemical profile in the serum. It was also noted that the HFD affected bacterial gut composition in comparison to the control group with gram-positive cocci dominance in the control group compared to obese. The results of the present study confirm that obesity is linked to inflammation, oxidative stress, dyslipidemic processes, and altered brain neurotransmitter levels that can cause obesity-related neuropsychiatric complications.


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