Comparative study of macrophages in naked mole rats and ICR mice

// Jishuai Cheng 1, * , Zheng Yuan 2, * , Wenjing Yang 1, * , Chang Xu 3, * , Wei Cong 1 , Lifang Lin 1 , Shanmin Zhao 1 , Wei Sun 1 , Xiaosong Bai 4 and Shufang Cui 1 1 Laboratory Animal Centre, Second Military Medical University, Shanghai, China 2 Department of Science and Technology, Academy of Military Medical Sciences, Beijing, China 3 School of Kinesiology, Shanghai University of Sport, Shanghai, China 4 Department of Clinical Laboratory, Shi Dong Hospital, Shanghai, China * These authors have contributed equally to this work Correspondence to: Shufang Cui, email: youngstar_sf@163.com Keywords: naked mole rats, ICR mice, spleen, macrophage, immune response Received: March 24, 2017     Accepted: May 29, 2017     Published: July 28, 2017 ABSTRACT The domestic and foreign scholars have studied naked mole rats more focused on the respect such as its long life, resistant to low oxygen, little spontaneous tumor, but the study of the immune system is little. In this study, we compared the anatomy and tissue morphology of NMR and ICR mouse spleens and found that the gross appearance of the NNMR spleen differed from ICR. There were more macrophages in NNMR spleens than in ICR spleens. Furthermore, we focused on the differences of macrophages. We compared their phagocytic capabilities and the data showed that NNMR macrophages are more phagocytic than ICR mouse macrophages. We also used polyI:C and LPS to stimulate the NMR and ICR macrophages and then measured the immune response as expression of certain TLR signaling molecules. After stimulation, there was a lower increase in apoptosis of NMR macrophages than ICR macrophages and a non-significant increased expression of TLRs in NMR macrophages than in ICR macrophages. In contrast, NF-κB proteins increased more significantly in NMR’s than in ICR’s and the expression of downstream cytokines in NMR macrophages also increased more than in ICR macrophages. Based on these results, we hypothesize that in addition to being able to eat foreign matter, NMR macrophages can activate the TLRs, start the NF-κB and produce a large number of cytokines to enhance immune response, so as to protect the body from outside interference when the virus or bacteria invading.