Funding for this research was provided by:
National Institute on Aging (ZIA AG000946)
National Natural Science Foundation of China (81601117)
Natural Science Foundation of Beijing Municipality (7152077)
Beijing Nova Program (xx2018099)
Beijing Hundreds and Thousands of Talents Project (2017A14)
Received: 19 September 2017
Accepted: 19 February 2018
First Online: 1 March 2018
: All animal procedures conformed to the NIH guide for the ethical care and use of laboratory animals. Animal protocols were approved by the Institutional Animal Care and Use Committee of National Institute on Aging.
: All authors have read the manuscript and indicated consent for publication.
: The authors declare that they have no competing interests.
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