Assess effects of hAMSCs on ovarian function of DOR mice

The safe dose of hAMSCs via tail vein injection in mouse is below 5.0 × 10⁷cells/kg body weight according to our exploration (submitted and under review data). The AR-DOR model mice were randomly assigned into 5 groups (22 mice/group): the normal saline group (NS), the 1% human serum albumin group (HSA), the low-dose group (LD, 5.0 × 10⁶cells/kg), the medium-dose group (MD, 7.5 × 10⁶cells/kg), and the high-douse group (HD, 1.0 × 10⁷cells/kg). Each mouse was slowly injected with 300 μl of the corresponding preparation through the tail intravenous for total 3 times at a 4-day interval [30, 34]. Seven days after the last injection, venous blood was collected from 8 mice of each group to perform hormone assay, and then humanely sacrificed to carry out follicles and oocyte counting, 2-cell and blastocyst formation, apoptosis analysis, histology, and immunofluorescence assay, and 6 mice from each group were humanely sacrificed to collect ovary to perform western blot assay. About 2 weeks after the last injection, the left mice from each group were humanely sacrificed to perform analysis on gestation rate and number of live fetus.