The animal protocol conformed to US NIH guidelines (Guide for the Care and Use of Laboratory Animals, No. 85–23, revised 1996), and was reviewed and approved by the Institutional Animal Care and Use Committee (from Wuhan University). The C57Bl/6 mice were housed 4 or 5 per cage on a 12:12-h light-dark cycle and were given phytoestrogen-free commercial rodent chow and water ad libitum on arrival.
Animal Protocol 1: The 2-month female mice were anaesthetized by intraperitoneal injection of 100mg/kg ketamine/16mg/kg xylazine, and received treatments consisting of 60-day time release pellets (Innovative Research of America) that were implanted subcutaneously via a ~3mm incision on the dorsal aspect of the neck. Hormone pellets contained 5mg of either dihydrotestosterone (DHT, #A-161), estradiol (E2, #E-121), combined DHT and E2 (DHT/E2), or vehicle pellets (CTL) containing the same matrix but with no hormone [15 (
link)]. After 1 week of surgery recovery, the female mice mated with male mice, and successful pregnancy was confirmed by examining the vaginal plugs. The pregnant mice were kept fed until baby delivery (~3 weeks) with another 3-week of lactation for the offspring. The mothers were sacrificed, and the blood was collected for analysis of hormones by radioimmunoassay. The EPCs were isolated from both bone marrow and peripheral blood [16 (
link)] for gene expression analysis. The male offspring were selected and fed with high-fat diet (HFD, 60% calories from fat, Research Diets, #D12492) throughout the experiments. Parts of the young (4 months) and old (20 months) offspring were overnight-fasted, euthanized by 100mg/kg pentobarbital, and the EPCs were isolated for gene expression analysis. The EPCs numbers were counted [17 (
link)] and the EPCs characteristics for colony form unit (CFU) [18 (
link)] and migration [16 (
link)] were evaluated. The tissues, including liver, heart and aorta were isolated for gene expression analysis or in vivo lipid uptake, and the blood was collected for measuring lipids, including total cholesterol, triglyceride, LDL and HDL cholesterol [14 (
link)]. The MECs from the aorta were isolated for in vitro cell culture analysis [19 (
link), 20 (
link)], and the MECs from the thoracic aortas [21 (
link)] were picked up by Laser Capture Microdissection (LCM) for mRNA analysis, and the vascular function was evaluated by vessel tension [22 (
link), 23 (
link)] and blood pressure [24 (
link)–26 (
link)] as described previously in our lab [14 (
link)].
Animal Protocol 2: The male offspring from CTL or DHT group in Animal Protocol 1 were used as recipients for bone marrow transplantation (BMT). Bone marrow cells were harvested from the tibias and femurs of the male offspring (4 months old) that were obtained from CTL group in Animal Protocol 1 as the donor for BMT. The isolated MNCs were purified by density centrifugation using Histopaque 1083
® (#-1083-1, Sigma), and resuspended in 10ml of RPMI 1640 supplemented with 10% FBS and 2mM EDTA. We then added 4μg/ml of final concentration of polybrene with 100μl of concentrated lentivirus (1×10
7 cfu/ml), which included either Tie2-EMP, or Tie2-ERβ, or Tie2-SIRT1-C152(D) or Tie2-shERβ. We incubated the cells for 6 hours to achieve maximum 100% viral infection of cells. A parallel viral infection on the same MNCs cells was achieved using 100μl of 1×10
7 cfu/ml of pLVX-AcGFP1-C1 virus (#632155, Clontech) that can express GFP (green fluorescent proteins). The efficiency of viral infection was confirmed as ~100% using fluorescent microscopy. The above lentivirus infected MNCs were washed twice and resuspended by PBS, and then systemically transplanted (2×10
6 cells) into the above recipient male offspring (with CTL or DHT group) that had been lethally irradiated with 2 doses of 6 Gy 3 hours apart. All transplant-recipient mice were set aside for a minimum of 4 weeks to allow for complete reconstitution of the bone marrow [10 (
link)], see details in
S1 Table. The bone marrow transplanted mice were overnight-fasted and euthanized at the age of 20 months. The EPCs and MECs were isolated for in vitro cell culture analysis, or the MECs and SMCs (smooth muscle cells) were isolated by LCM for mRNA analysis, and parts of the mice were used for vascular function analysis.
Xie W., Ren M., Li L., Zhu Y., Chu Z., Zhu Z., Ruan Q., Lou W., Zhang H., Han Z., Huang X., Xiang W., Wang T, & Yao P. (2017). Perinatal testosterone exposure potentiates vascular dysfunction by ERβ suppression in endothelial progenitor cells. PLoS ONE, 12(8), e0182945.