BACKGROUND:Recent studies have found that stem cellpluripotency and differentiation is regulated by many long non-coding RNAs (LncRNAs). The expression and effect of LncRNA AK089560 during differentiation of stem cells is unclear. OBJECTIVE:To investigate the expression of LncRNA AK089560 in mesenchymal stem cells C3H10T1/2 undergoing osteogenic and adipogenic differentiation. METHODS:Osteogenic differentiation of mesenchymal stem cells C3H10T1/2 was induced by recombinant human bone morphogenetic protein-2 and evaluated using alkaline phosphatase staining. The adipogenic differentiation of mesenchymal stem cells C3H10T1/2 was induced by three factors (dexamethasone, indomethacin and insulin) and evaluated by oil red O staining. The dynamical expression of LncRNA AK089560 was detected by qRT-PCR assay. The AK089560 secondary structure was predicted using RNAfold software. The relationship between AK089560 and neighboring protein-coding genes was analyzed using UCSC genome browser and visualized by fancyGENE online software. RESULTS AND CONCLUSION:Over 70%of C3H10T1/2 cells were positive for alkaline phosphatase after osteogenic induction and more than 80%of the cells positive for oil red O staining after adipogenic induction. qRT-PCR results showed that the expression of LncRNA AK089560 at days 2, 4, 6 of both osteogenic and adipogenic differentiation was significantly decreased compared with the control group (P<0.05). Bioinformatics analysis showed that there was a stem-loop structure for AK089560 and sense overlap relationship between AK089560 and protein-encoding gene Sema3a. These findings indicate that LncRNA AK089560 expression is reduced during osteogenic differentiation and adipogenic differentiation, showing that AK089560 may be involved in regulating the multi-directional differentiation of stem cells.

Aim To investigate whether D-galactose cause osteoporosis and the difference compared with the osteoporosis induced by ovariectomy, and to deter-mine whether ovariectomy coupled with D-galactose ac-celerated the progress of osteoporosis and whether es-trogen had a preventive effect on these osteoporosis models. Methods Sixty SPF mice were randomly divided into six groups , namely sham-operated group, D-galactose group, OVX group, OVX + D-galactose group, OVX + D-galactose + diethylstilbestrol group and D-galactose + diethylstilbestrol group. Seventy days later, the right tibia was processed with undecal-cified sections for bone histomorphometric analysis. Results Compared with the sham-operated group, %Tb. Ar, Tb. Th and Tb. N decrease by 50. 4%, 25. 4%, 50. 9% ( P <0.01 ) respectively, Tb. Sp in-creased by 169. 4% (P <0.05), Oc. pm, Oc. No. ,%Oc. S, Oc. N/mm which reflected bone absorption significantly increased ( P < 0.01 ) , and % L. Pm, MAR, BFR/TV, BFR/BV, BFR/BS which reflected bone formation significantly decreased ( P <0.01 ) in OVX group. %Tb. Ar decreased by 30. 4% in D-ga-lactose group, but there was no statistically significant difference. However, the four parameters reflected the bone absorption in D-galactose group increased signifi-cantly ( P<0.05 ) , while the four parameters reflected bone formation decreased significantly ( P < 0.05 ) . OVX+D-galactose group has obvious performance of osteoporosis, but there was no significant difference compared to OVX group, nor to D-galactose group. Estrogen had significant preventive effect on related pa-rameters of osteoporosis induced by D-galactose and o-variectomy coupled with D-galactose. ConclusionsOsteoporosis model of mice can be established by OVX, D-galactose and OVX +D-galactose. Estrogen can effectively prevent bone loss induced by D-galac-tose and OVX+ D-galactose.