scholarly journals NOX4 Deficiency Exacerbates the Impairment of Cystatin C-Dependent Hippocampal Neurogenesis by a Chronic High Fat Diet

Genes ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 567
Author(s):  
Piyanart Jiranugrom ◽  
Ik Dong Yoo ◽  
Min Woo Park ◽  
Ji Hwan Ryu ◽  
Jong-Seok Moon ◽  
...  

Hippocampal neurogenesis is linked with a cognitive process under a normal physiological condition including learning, memory, pattern separation, and cognitive flexibility. Hippocampal neurogenesis is altered by multiple factors such as the systemic metabolic changes. NADPH oxidase 4 (NOX4) has been implicated in the regulation of brain function. While the role of NOX4 plays in the brain, the mechanism by which NOX4 regulates hippocampal neurogenesis under metabolic stress is unclear. In this case, we show that NOX4 deficiency exacerbates the impairment of hippocampal neurogenesis by inhibiting neuronal maturation by a chronic high fat diet (HFD). NOX4 deficiency resulted in less hippocampal neurogenesis by decreasing doublecortin (DCX)-positive neuroblasts, a neuronal differentiation marker, and their branched-dendrites. Notably, NOX4 deficiency exacerbates the impairment of hippocampal neurogenesis by chronic HFD. Moreover, NOX4 deficiency had a significant reduction of Cystatin C levels, which is critical for hippocampal neurogenesis, under chronic HFD as well as normal chow (NC) diet. Furthermore, the reduction of Cystatin C levels was correlated with the impairment of hippocampal neurogenesis in NOX4 deficient and wild-type (WT) mice under chronic HFD. Our results suggest that NOX4 regulates the impairment of Cystatin C-dependent hippocampal neurogenesis under chronic HFD.

Author(s):  
Kathryn Mary Spitler ◽  
Shwetha K Shetty ◽  
Emily M Cushing ◽  
Kelli L. Sylvers-Davie ◽  
Brandon S.J. Davies

Obesity is associated with dyslipidemia, ectopic lipid deposition and insulin resistance. In mice, the global or adipose-specific loss of function of the protein angiopoietin-like 4 (ANGPTL4) leads to decreased plasma triglyceride levels, enhanced adipose triglyceride uptake, and protection from high-fat diet-induced glucose intolerance. ANGPTL4 is also expressed highly in the liver, but the role of liver-derived ANGPTL4 is unclear. The goal of this study was to determine the contribution of hepatocyte ANGPTL4 to triglyceride and glucose homeostasis in mice during a high fat diet challenge. We generated hepatocyte-specific ANGPTL4 deficient (Angptl4LivKO) mice, fed them a 60% kCal/fat diet (HFD) for 6 months, and assessed triglyceride, liver, and glucose metabolic phenotypes. We also explored the effects of prolonged fasting on Angptl4LivKO mice. The loss of hepatocyte-derived Angptl4 led to no major changes in triglyceride partitioning or lipoprotein lipase activity compared to control mice. Interestingly, although there was no difference in fasting plasma triglyceride levels after a 6 h fast, after an 18 h fast normal chow diet fed Angptl4LivKO mice had lower triglyceride levels than control mice. On a HFD, Angptl4LivKO mice initially showed no difference in glucose tolerance and insulin sensitivity, but improved glucose tolerance emerged in these mice after 6 months on HFD. Our data suggest that hepatocyte ANGPTL4 does not directly regulate triglyceride partitioning, but that loss of liver-derived ANGPTL4 may be protective from HFD-induced glucose intolerance and influence plasma TG metabolism during prolonged fasting.


eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Santiago Vernia ◽  
Caroline Morel ◽  
Joseph C Madara ◽  
Julie Cavanagh-Kyros ◽  
Tamera Barrett ◽  
...  

The cJun NH2-terminal kinase (JNK) signaling pathway is implicated in the response to metabolic stress. Indeed, it is established that the ubiquitously expressed JNK1 and JNK2 isoforms regulate energy expenditure and insulin resistance. However, the role of the neuron-specific isoform JNK3 is unclear. Here we demonstrate that JNK3 deficiency causes hyperphagia selectively in high fat diet (HFD)-fed mice. JNK3 deficiency in neurons that express the leptin receptor LEPRb was sufficient to cause HFD-dependent hyperphagia. Studies of sub-groups of leptin-responsive neurons demonstrated that JNK3 deficiency in AgRP neurons, but not POMC neurons, was sufficient to cause the hyperphagic response. These effects of JNK3 deficiency were associated with enhanced excitatory signaling by AgRP neurons in HFD-fed mice. JNK3 therefore provides a mechanism that contributes to homeostatic regulation of energy balance in response to metabolic stress.


2017 ◽  
Vol 117 (01) ◽  
pp. 19-26 ◽  
Author(s):  
Lotte Geys ◽  
Dries Bauters ◽  
Elien Roose ◽  
Claudia Tersteeg ◽  
Karen Vanhoorelbeke ◽  
...  

SummaryADAMTS13 cleaves ultralarge multimeric von Willebrand Factor (VWF), thereby preventing formation of platelet-rich microthrombi. ADAMTS13 is mainly produced by hepatic stellate cells, and numerous studies have suggested a functional role of ADAMTS13 in the pathogenesis of liver diseases. The aim of our study was to investigate a potential role of ADAMTS13 in formation of hepatic microthrombi and development of non-alcoholic steatohepatitis (NASH), and furthermore to evaluate whether plasmin can compensate for the absence of ADAMTS13 in removal of thrombi. Therefore, we used a model of high-fat diet-induced steatosis in Adamts13 deficient (Adamts13−/−) and wild-type (WT) control mice. Microthrombi were more abundant in the liver of obese Adamts13−/− as compared to obese WT or to lean Adamts13−/− mice. Obese Adamts13−/− mice displayed lower platelet counts and higher prevalence of ultra-large VWF multimers. Hepatic plasmin-α2-antiplasmin complex levels were comparable for obese WT and Adamts13−/− mice and were lower for lean Adamts13−/− than WT mice, not supporting marked activation of the fibrinolytic system. High fat diet feeding, as compared to normal chow, resulted in enhanced liver triglyceride levels for both genotypes (p < 0.0001) and steatosis (p < 0.0001 for WT mice, p = 0.002 for Adamts13−/− mice) without differences between the genotypes. Expression of markers of inflammation, oxidative stress, steatosis and fibrosis was affected by diet, but not by genotype. Thus, our data confirm that obesity promotes NASH, but do not support a detrimental role of ADAMTS13 in its development. However, Adamts13 deficiency in obese mice promotes hepatic microthrombosis, whereas a compensatory role of plasmin in removal of microthrombi in the absence of ADAMTS13 could not be demonstrated.


Planta Medica ◽  
2011 ◽  
Vol 77 (12) ◽  
Author(s):  
C Charkhonpunya ◽  
S Sireeratawong ◽  
S Komindr ◽  
N Lerdvuthisopon

2016 ◽  
Author(s):  
Ann-Kristin Picke ◽  
Lykke Sylow ◽  
Lisbeth L V Moller ◽  
Rasmus Kjobsted ◽  
Erik Richter ◽  
...  

2021 ◽  
Vol 137 ◽  
pp. 111370
Author(s):  
Chethan Sampath ◽  
Derek Wilus ◽  
Mohammad Tabatabai ◽  
Michael L. Freeman ◽  
Pandu R. Gangula

Nutrients ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1740
Author(s):  
Yuning Pang ◽  
Xiang Xu ◽  
Xiaojun Xiang ◽  
Yongnan Li ◽  
Zengqi Zhao ◽  
...  

A high-fat diet often leads to excessive fat deposition and adversely affects the organism. However, the mechanism of liver fat deposition induced by high fat is still unclear. Therefore, this study aimed at acetyl-CoA carboxylase (ACC) to explore the mechanism of excessive liver deposition induced by high fat. In the present study, the ORF of ACC1 and ACC2 were cloned and characterized. Meanwhile, the mRNA and protein of ACC1 and ACC2 were increased in liver fed with a high-fat diet (HFD) or in hepatocytes incubated with oleic acid (OA). The phosphorylation of ACC was also decreased in hepatocytes incubated with OA. Moreover, AICAR dramatically improved the phosphorylation of ACC, and OA significantly inhibited the phosphorylation of the AMPK/ACC pathway. Further experiments showed that OA increased global O-GlcNAcylation and agonist of O-GlcNAcylation significantly inhibited the phosphorylation of AMPK and ACC. Importantly, the disorder of lipid metabolism caused by HFD or OA could be rescued by treating CP-640186, the dual inhibitor of ACC1 and ACC2. These observations suggested that high fat may activate O-GlcNAcylation and affect the AMPK/ACC pathway to regulate lipid synthesis, and also emphasized the importance of the role of ACC in lipid homeostasis.


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