SHANK3 Deficiency in AgRP Neurons Inhibits Diet-Induced Obesity by Activating p38α

Shanshan Wu1,2,3,4 · Yixiao Liang1,2,3 · Yang Xu1,2,3 · Yueping Ge1,2,3 · Jing Wang1,2,3 · Lu Wang2  · Xinchen Jin5  · Huidong Zhan1,2,3 · Li Peng1,2,3 · Ling Gao2  · Jiajun Zhao2  · Zhao He1,2,3

1 Department of Endocrinology, Shandong Provincial Hospital, Shandong University, Jinan 250021, China 

2 Key Laboratory of Endocrine Glucose and Lipids Metabolism and Brain Aging, Ministry of Education, Shandong Key Laboratory of Endocrinology and Lipid Metabolism; Shandong Institute of Endocrine and Metabolic Diseases, Shandong Clinical Research Center of Diabetes and Metabolic Diseases, Shandong Prevention and Control Engineering Laboratory of Endocrine and Metabolic Diseases, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan 250021, China 

3 Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Department of Cardiology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250021, China 

4 Department of Endocrinology, Drum Tower Hospital Affiliated to Nanjing University Medical School, Branch of National Clinical Research Centre for Metabolic Diseases, Nanjing 210003, China 

5 Advanced Medical Research Institute, Cheeloo College of Medicine, Shandong University, Jinan 250012, China

Abstract

Children with autism often exhibit abnormalities in body weight, but the underlying mechanism remains unclear. SH3 and multiple ankyrin repeat domains protein 3 (SHANK3), a scaffold protein of the postsynaptic density, has been reported to be associated with autism. This study aimed to investigate whether and how SHANK3 influences body weight in the hypothalamic neuronal regulation of energy homeostasis. Adeno-associated viruses 9 (AAV9) carrying CMV-Cre and Agrp-Cre were stereotactically injected to restore SHANK3 expression in the arcuate nucleus (ARC) and agouti-related peptide (AgRP) neurons, respectively. Agrp-Cre mice were injected with AAV9-p38αflox/flox to overexpress p38α. Activated p38α was generated by mutating both D176A and F327S in p38α. Inactivated p38α was constructed by mutating both T180A and Y182F in p38α. Metabolic analysis, immunoblotting, histological analysis, the glucose tolerance test, the insulin tolerance test, and body fat mass analysis were applied to investigate the underlying mechanisms by which SHANK3 regulates body weight. We reveal that SHANK3 regulates body weight via the p38α signaling pathway in the AgRP neurons of the hypothalamus. Shank3 knockout (Shank3−/−) mice exhibit resistance to diet-induced obesity. Shank3 re-expression in the ARC or AgRP neurons increases body weight in Shank3 knock-in mice with an inverted allele (SKO). Overexpression or activation of p38α in AgRP neurons elicits resistance to diet-induced obesity. Inactivated p38α in AgRP neurons abolished the resistance to diet-induced obesity due to SHANK3 deficiency. Our findings suggest that the SHANK3-p38α siganling pathway in AgRP neurons regulates body weight balance in autism, revealing a promising therapeutic target for obesity in children with autism.

Keywords

SHANK3; p38α; Agouti-related peptide; Autism; Body weight

[SpringerLink]