〔Abstract〕 Objective To investigate the effect of SHP2 protein phase separation induced by activation mutation on cell proliferation and its mechanism through construct a mouse model of SHP2E76Kmutation. Methods Hybrid PTPN11E76K-NEO/+C57BL/6J mouse were hybridizedwith Mx1-cre tool mice to obtain the required Mx1-cre; Ptpn11+/+and Mx1-cre; Ptpn11E76K/+. The later genotype mice were injected with pI-pC to induce the expression of Cre enzyme and mutate Ptpn11E76K in bone marrow mesenchymal stem cells(MSC).The Mx1-cre; Ptpn11+/+and Mx1-cre; Ptpn11E76K/+genotype mice′s cells were isolated and culturedin vitroand identified as MSCs by immunofluorescence staining.With Ptpn11+/+MSC as the control group and Ptpn11E76K/+MSC as the experimental group, the two kinds of cells were divided into 6 groups by adding drugs: Ptpn11+/+group; Ptpn11+/++SHP099 group; Ptpn11+/++ET070 group; Ptpn11E76K/+group; Ptpn11E76K/++SHP099 group; Ptpn11E76K/++ET070 group. The differences of SHP2 protein phase separation in the six groups were observed by immunofluorescencestaining, and the differences of SHP2 protein expression were detectedby Western blot. CCK-8 was used to observe the changes of cell proliferation after phase separation was affected. Western blot was used to detect the expression levels of ERK/p-ERK,AMPK/p-AMPK, mTOR/p-mTOR and other molecules between the six groups. Results Genotypes Mx1-cre; Ptpn11E76K/+and Mx1-cre; Ptpn11+/+mice were obtained by genotyping, and the primary MSCs were isolated.Compared with Ptpn11+/+group, SHP2 proteins in the Ptpn11E76K/+group produced more phase separation condensates, and compared with Ptpn11E76K/+group, the SHP2 proteins in the Ptpn11E76K/++SHP099 and Ptpn11E76K/++ET070 groups produced less phase separation condensates.No difference in SHP2 protein expression levels between groups was detected by Western blot. Compared with Ptpn11+/+group, the proliferation ability of MSC in Ptpn11+/++SHP099 and Ptpn11+/++ET070 groups decreased, the expression of p-ERK and p-mTOR decreased, and the expression of p-AMPK protein increased. Compared with Ptpn11E76K/+group, the proliferation ability of MSC in Ptpn11E76K/++SHP099 and Ptpn11E76K/++ET070 groups decreased, the expression of p-ERK and p-mTOR decreased, and the expression of p-AMPK protein increased. Conclusion SHP2 phase isolation is involved in the alteration of proliferative capacity of SHP2E76K-activated MSCs by stimulating the expression of AMPK-mTOR signaling pathway.