动物造模,人脐带间充质干细胞 z-bio 2023-03-07 474

　　Objective To investigate whether transplantation of human umbilical cord mesenchymal stem cells can improve learning and memory and cognitive decline by regulating autophagy level in naturally aging rats.

　　Methods SD rats were reared in barrier environment until the age of aging (24 months). The aged rats with obvious cognitive decline were selected from behavioral studies and divided into cell transplantation group (Group H) and normal saline group (Group C). Three month old SD rats were normal group (Group N). Group H; Tail vein injection of hUCMSCs cell suspension 500 μ 50. The dosage is 2 for each × 10 *, sterile normal saline was injected into tail vein of group C and group N respectively. The time is once a week for 4 consecutive weeks. Morris water maze, Y maze and new object recognition experiment were used to observe the change of learning and memory ability; The morphological changes of hippocampal neurons were observed by HE staining; The relative expression of LC3II/I, Beclin1, P62 in hippocampus was detected by Western Blot.

　　Results (1) The behavioral results showed that the learning and memory abilities of group H and group N were significantly higher than those of group C. (2) In HE staining, the arrangement of nerve cells in CA1 and DG areas of hippocampus in H and N groups was regular, the cell structure was complete, and the nucleus was full. The number of neurons in CA1 area of group C was reduced, the cells were loosely arranged, and the nucleus was pyknotic, showing degenerative changes. (3) P62 protein content in group H and N was significantly lower than that in group C, and Beclin1 and LC3 Ⅱ/I were significantly higher than that in group C.

　　Conclusion Intravenous injection of human umbilical cord mesenchymal stem cells improves learning and memory and cognitive decline in naturally aging rats, which may be related to the recovery of autophagy level after intervention.