This work was supported by National Natural Science Foundation of China (81100106, 81100212, 81670424), Hunan Provincial Natural Science Foundation of China (2018JJ2345), Hunan Provincial Innovation Foundation for Postgraduate (CX2018B617), Scientific Research Foundation for doctor of University of South China (2012XQD37), and the Scientific Research Foundation for the Returned Overseas Scholars of University of South China (2017XQD29). The author thanks Lin Chang, research assistant professor, Internal Medicine, Medical School, for valuable discussions and insights on this manuscript. Reviewers are thanked for their suggeations.