1. Department of Metabolism & Endocrinology, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
2. National Clinical Research Center for Metabolic Diseases, Changsha, Hunan, China
3. Key Laboratory of Diabetes Immunology (Central South University), Ministry of Education, Changsha, Hunan 410011, China
4. State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong, China