Effects of total flavonoids of Epimedium sagittatum on the mRNA expression of the estrogen receptor α and β in hypothalamus and hippocampus in ovariectomized rats / 中南大学学报(医学版)

Objective To explore the effect of total flavonoids of Epimedium sagittatum (TFE) on the mRNA expressions of the estrogen receptor alpha (ERα) and estrogen receptor beta(ERβ) in hippocampus and hypothalamus in ovariectomized (OVX) Sprague-Dawley(SD) rats, and the mechanism of TFE against postmenopausal osteoporosis. Methods Forty-eight female SD rats,aged 10-11 months old, were randomly divided into 4 groups: a sham group, an ovariectomy group (rats were bilaterally ovariectomized), a TFE group, and a 17β-estradiol group (rats were fed with TFE and 17β-estradiol for 4 months, respectively). The RT-PCR was performed to determine the mRNA expression of ERα and ERβ in hypothalamus and hippocampus. Results Serum estradiol level, bone mineral density (BMD) of vertebra,wet weight of uterus, and the mRNA expressions of ERα and ERβ in hypothalamus and hippocampus were markedly decreased in OVX rats, all of which were reversed by 17β-estradiol treatment except the mRNA expression of ERβ. Similar results were achieved by TFE treatment except the wet weight of uterus. Conclusion TFE can improve BMD of vertebra in the OVX rats without side effects on the uterus. The mechanism may be related to increasing the mRNA expressions of ERα and ERβ in hypothalamus and hippocampus.

Retrovirus Mediated Gene Transfer of RANK-Fc Ameliorates Bone Loss in a Mouse Ovariectomy Model of Osteoporosis / 대한내분비학회지

BACKGROUND: Interactions between the receptor activator of the NF-kappaB ligand (RANKL) and its receptor, RANK, are important in the terminal differentiation and activation of osteoclasts. In the current investigation, we examine the feasibility of using genetically modified mesenchymal stem cells (MSCs), C3H10T1/2 cells as a platform for the sustained systemic delivery of therapeutic proteins into the circulation in an osteoporosis model, and investigate retroviral-mediated gene therapy of RANK-Fc as a means of ameliorating ovariectomy (OVX)-induced bone resorption. METHODS: C3H10T1/2 cells were transduced with a MSCV-based retroviral vector containing cDNA of a fusion protein combining the extracellular domain of murine RANK with the human immunoglobulin constant domain (MSCV-RANK-Fc-eGFP). Young adult female mice were subjected to OVX or sham surgery, followed by treatment with transduced cells or PBS 4 weeks later. The expression of RANK-Fc by these cells was assessed, both in vitro and in vivo. Total bone mineral density (BMD) was measured and GFP expression was examined. RESULTS: Transduced cells produced biologically active RANK-Fc in vitro and in vivo. Mice that were subjected to OVX followed by treatment with cells transduced with MSCV-RANK-Fc-eGFP 4 weeks later contained no significant but higher total BMD than either the control vector or PBS-treated mice after 8 weeks. Higher GFP expression was attained in the liver, spleen, and intra-abdominal fat of mice treated with MSCV-RANK-Fc-eGFP. CONCLUSION: The data collectively indicate that C3H10T1/2 cells are effectively transduced with a MSCV-based retrovirus, and are capable of secreting biologically active RANK-Fc in vitro and in vivo. Moreover, gene therapy facilitating the sustained delivery of RANK-Fc may be an effective method to reverse OVX-induced osteoporosis.

EXPERIMENTAL STUDY OF PERI-IMPLANT TISSUE REACTION IN OVARIECTOMIZED OSTEOPOROTIC RATS / 대한치과보철학회지

This study was designed to investigate the peri-implant tissue reaction in ovariectomized osteoporotic female rats, and to evaluate effects of estrogen, calcitonin, parathyroid hormone on the bone - implant interface in osteoporotic rats. 120 Sprague - Dawley rats were used in this experiments. Osteoporosis was induced by bilateral ovariectomy. They were divided 5 groups ; sham-operated control group(Sham), ovariectomized group (OVX), OVX and estrogen treated group (OVX+E), OVX and PTH treated group (OVX+PTH), and OVX and calcitonin treated group (OVX+CT). Eight weeks after ovariectomy, two titanium screw implants were inserted into the left tibia of each rat. Eight weeks after the insertion of the implants, the periotest values (PTV) of implant were examined, and the rats were sacrificed, and examined the reaction of bone tissue surrounding the implant both histologically and histomorphometrically. The bone density and ash weight of opposite right tibia were examined. Over 40 rats were fractured on left tibia that was implant inserted. On histologically finding, all groups were osseointegrated well, especially in OVX+PTH group. In OVX group, tibial cortical bone showed many large harversian canal and microfracture lines. The OVX+PTH group showed the lowest mean PTV (-2.33) (p0.05). But the OVX+CT group showed the highest mean bone density (5.45mg/cm3) and ash weight (56.12%) (p<0.05). The results indicate that PTH treatment enhances osseointegration of implant in OVX rats, and CT treatment depresses bone turnover and prevent the development of osteopenia in OVX rats.

Effect of Fructus Ligustri Lucidi on calcium metabolism and vitamin D-dependent gene expressions in ovariectomized rats / 中草药

Objective To investigate the effect of Fructus Ligustri Lucidi(FLL),a kidney-tonifying Chinese herbal medicine,on calcium metabolism and vitamin D-dependent gene expression in ovariectomized(OVX) rats.Methods Four weeks after OVX surgical operation the OVX rats were ig admini-(stered) with estradiol and FLL for 14 weeks.Ca~(2+) Level in serum,urine,and feces was measured by colorimetric methods,and gene expressions in duodenum and kidney were analyzed by reversed transcriptase-polymerase chain reaction(RT-PCR).Results Ovariectomy of rat led to significant loss of calcium in vivo,as demonstrated by decreasing serum Ca~(2+) level and increasing Ca~(2+) excretion rate in urine and feces in OVX rat group.Treatment of OVX rats with FLL could effectively restore serum Ca~(2+) level and prevent the increase of Ca~(2+) excretion from urine and feces.RT-PCR Analysis showed that both estradiol and FLL could prevent OVX-induced decrease of mRNA expression in duodenal vitamin D receptor(VDR).In kidney,FLL did not alter mRNA expressions of 25-hydroxyvitamin D 1-hydroxylase(1-OHase) and 25-hydroxyvitamin D 24-hydroxylase(24-OHase),while increased the mRNA expression levels of renal cal-ciumbinding protein-9k(CaBP-9k) and calcium-binding protein-28k(CaBP-28k).Conclusion FLL could improve the state of calcium imbalance induced by estrogen deficiency and the potential mechanism that contributes to the improvement of calcium status by FLL might involve the increase in intestinal sensitivity to active vitamin D through its up-regulation of VDR expression in duodenum and the enhancement in Ca~(2+) reabsorption via the up-regulation of calcium binding proteins expression in kidney.