The effects of vitamin D on osteoblast mineralization are well documented. Reports of the effects of vitamin D on osteoclasts, however, are conflicting, showing both inhibition and stimulation. Finding that resorbing ...The effects of vitamin D on osteoblast mineralization are well documented. Reports of the effects of vitamin D on osteoclasts, however, are conflicting, showing both inhibition and stimulation. Finding that resorbing osteoclasts in human bone express vitamin D receptor （VDR）, we examined their response to different concentrations of 25-hydroxy vitamin D3 [25（OH）D3] （100 or 500 nmol·L^-1） and 1,25-dihydroxy vitamin D3 [1,25（OH）2D3] （0.1 or 0.5 nmol·L^-1） metabolites in cell cultures. Specifically, CD14＋ monocytes were cultured in charcoal-stripped serum in the presence of receptor activator of nuclear factor kappa-B ligand （RANKL） and macrophage colony-stimulating factor （M-CSF）. Tartrate-resistant acid phosphatase （TRAP） histochemical staining assays and dentine resorption analysis were used to identify the size and number of osteoclast cells, number of nuclei per cell and resorption activity. The expression of VDR was detected in human bone tissue （ex vivo） by immunohistochemistry and in vitro cell cultures by western blotting. Quantitative reverse transcription-PCR （qRT-PCR） was used to determine the level of expression of vitamin D-related genes in response to vitamin D metabolites. VDR-related genes during osteoclastogenesis, shown by qRT-PCR, was stimulated in response to 500 nmol·L^-1 of 25（OH）D3 and 0.1-0.5 nmol·L^-1 of 1,25（OH）2D3, upregulating cytochrome P450 family 27 subfamily B member I （CYP27B1） and cytochrome P450 family 24 subfamily A member I （CYP24A1）. Osteoclast fusion transcripts transmembrane 7 subfamily member 4 （tm7sf4） and nuclear factor of activated T-cell cytoplasmic 1 （nfatcl） where downregulated in response to vitamin D metabolites. Osteoclast number and resorption activity were also increased. Both 25（OH）D3 and 1,25（OH）2D3 reduced osteoclast size and number when co-treated with RANKL and M-CSF. The evidence for VDR expression in resorbing osteoclasts in vivo and low-dose effects of 1,25（OH）2D3 on osteoclasts in vitro may therefore provide insight into the effects of clinical vitamin D treatments, further providing a counterpoint to the high-dose effects reported from in vitro experiments.展开更多
Vitamin D co-regulates cell proliferation, differentiation and apoptosis in numerous tissues, including cancers. The known anti-proliferative and pro-apoptotic actions of the active metabolite of vitamin D, 1,25-dihyd...Vitamin D co-regulates cell proliferation, differentiation and apoptosis in numerous tissues, including cancers. The known anti-proliferative and pro-apoptotic actions of the active metabolite of vitamin D, 1,25-dihydroxy-vitamin D [1,25（OH）2D] are mediated through binding to the vitamin D receptor （VDR）. Here, we report on the unexpected finding that stable knockdown of VDR expression in the human breast and prostate cancer cell lines, MDA-MB-231 and PC3, strongly induces cell apoptosis and inhibits cell proliferation in vitro. Implantation of these VDR knockdown cells into the mammary fat pad （MDA-MB-231）, subcutaneously （PC3） or intra-tibially （both cell lines） in immune-incompetent nude mice resulted in reduced tumor growth associated with increased apoptosis and reduced cell proliferation compared with controls. These growth-retarding effects of VDR knockdown occur in the presence and absence of vitamin D and are independent of whether cells were grown in bone or soft tissues. Transcriptome analysis of VDR knockdown and non-target control cell lines demonstrated that loss of the VDR was associated with significant attenuation in the Wnt/0-catenin signaling pathway. In particular, cytoplasmic and nuclear β-catenin protein levels were reduced with a corresponding downregulation of downstream genes such as Axin2, Cyclin D1, interleukin-6 （IL-6）, and IL-8. Stabilization of 0-catenin using the GSK-3β inhibitor BIO partly reversed the growth-retarding effects of VDR knockdown. Our results indicate that the unliganded VDR possesses hitherto unknown functions to promote breast and prostate cancer growth, which appear to be operational not only within but also outside the bone environment. These novel functions contrast with the known anti-proliferative nuclear actions of the liganded VDR and may represent targets for new diagnostic and therapeutic approaches in breast and prostate cancer.展开更多
目的研究维生素D受体(V D R)基因多态性在中国汉族人群中的分布情况,并探讨V D R基因多态性与2型糖尿病的相关性。方法采用PC R-限制性片段长度多态性方法(R FLP),比较正常中国汉族人群和2型糖尿病患者之间V D R基因多态性等位基因频率...目的研究维生素D受体(V D R)基因多态性在中国汉族人群中的分布情况,并探讨V D R基因多态性与2型糖尿病的相关性。方法采用PC R-限制性片段长度多态性方法(R FLP),比较正常中国汉族人群和2型糖尿病患者之间V D R基因多态性等位基因频率和基因型频率的差异。结果V D R基因FokI酶切位点各基因型在2型糖尿病组和正常对照组中的分布差异具有显著统计学意义(χ2=9.993,P=0.007)。两组间等位基因频率总体分布差异有显著性(χ2=7.698,P=0.006)。D M组等位基因f和基因型ff频率明显高于N组,等位基因f与2型糖尿病呈明显正关联(R R=3.9,P<0.05)。结论中国汉族人群中V D R基因多态性与2型糖尿病相关联,等位基因f是2型糖尿病的易感基因。展开更多
目的探讨维生素D受体(vitamin D receptor,VDR)基因2个常见多态性位点基因型、等位基因频率与女性高危型人乳头状瘤病毒(human papilloma virus,HPV)感染的相关性。方法采用聚合酶链反应结合测序技术,对138例高危型HPV感染者及126例正...目的探讨维生素D受体(vitamin D receptor,VDR)基因2个常见多态性位点基因型、等位基因频率与女性高危型人乳头状瘤病毒(human papilloma virus,HPV)感染的相关性。方法采用聚合酶链反应结合测序技术,对138例高危型HPV感染者及126例正常对照者进行VDR基因ApaⅠ、TapⅠ2个SNP位点多态性的检测。结果高危型HPV感染组及对照组VDR基因ApaⅠ、TapⅠ2个SNP位点多态性分布频率均符合遗传学的Hardy-Weinberg平衡定律;高危型HPV感染组VDR基因ApaⅠ位点多态性基因型A/A、C/C和A/C的频率分别为5.8%、55.1%和39.1%,对照组分别为14.3%、52.4%和33.3%,经检验,高危型HPV感染组A/A基因型频率低于对照组,差异有统计学意义(χ2=5.345,P=0.021)。高危型HPV感染组VDR基因TapⅠ位点多态性基因型T/T和C/T的频率分别为88.4%和11.6%,对照组分别为85.7%和14.3%,2组TapⅠ位点多态性分布频率差异无统计学意义(P>0.05)。结论VDR基因多态性与高危型HPV感染风险相关。展开更多
基金financial support from Orthopaedic Research UK (P 470)Arthritis Research UK (grant 20299 and Oxford EOTC)
文摘The effects of vitamin D on osteoblast mineralization are well documented. Reports of the effects of vitamin D on osteoclasts, however, are conflicting, showing both inhibition and stimulation. Finding that resorbing osteoclasts in human bone express vitamin D receptor （VDR）, we examined their response to different concentrations of 25-hydroxy vitamin D3 [25（OH）D3] （100 or 500 nmol·L^-1） and 1,25-dihydroxy vitamin D3 [1,25（OH）2D3] （0.1 or 0.5 nmol·L^-1） metabolites in cell cultures. Specifically, CD14＋ monocytes were cultured in charcoal-stripped serum in the presence of receptor activator of nuclear factor kappa-B ligand （RANKL） and macrophage colony-stimulating factor （M-CSF）. Tartrate-resistant acid phosphatase （TRAP） histochemical staining assays and dentine resorption analysis were used to identify the size and number of osteoclast cells, number of nuclei per cell and resorption activity. The expression of VDR was detected in human bone tissue （ex vivo） by immunohistochemistry and in vitro cell cultures by western blotting. Quantitative reverse transcription-PCR （qRT-PCR） was used to determine the level of expression of vitamin D-related genes in response to vitamin D metabolites. VDR-related genes during osteoclastogenesis, shown by qRT-PCR, was stimulated in response to 500 nmol·L^-1 of 25（OH）D3 and 0.1-0.5 nmol·L^-1 of 1,25（OH）2D3, upregulating cytochrome P450 family 27 subfamily B member I （CYP27B1） and cytochrome P450 family 24 subfamily A member I （CYP24A1）. Osteoclast fusion transcripts transmembrane 7 subfamily member 4 （tm7sf4） and nuclear factor of activated T-cell cytoplasmic 1 （nfatcl） where downregulated in response to vitamin D metabolites. Osteoclast number and resorption activity were also increased. Both 25（OH）D3 and 1,25（OH）2D3 reduced osteoclast size and number when co-treated with RANKL and M-CSF. The evidence for VDR expression in resorbing osteoclasts in vivo and low-dose effects of 1,25（OH）2D3 on osteoclasts in vitro may therefore provide insight into the effects of clinical vitamin D treatments, further providing a counterpoint to the high-dose effects reported from in vitro experiments.
基金supported by Cancer Institute NSW CDF fellowship (YZ)Cure Cancer Foundation of Australia (YZ)+3 种基金Cancer Council New South Wales (MJS, YZ, HZ, and CRD)Prostate Cancer Foundation of Australia (MJS, YZ, HZ, and CRD)NH and MRC Early Career Fellowship 596870 (YZ)German Research Foundation HO 5109/2-1 and HO 5109/2-2 (KH)
文摘Vitamin D co-regulates cell proliferation, differentiation and apoptosis in numerous tissues, including cancers. The known anti-proliferative and pro-apoptotic actions of the active metabolite of vitamin D, 1,25-dihydroxy-vitamin D [1,25（OH）2D] are mediated through binding to the vitamin D receptor （VDR）. Here, we report on the unexpected finding that stable knockdown of VDR expression in the human breast and prostate cancer cell lines, MDA-MB-231 and PC3, strongly induces cell apoptosis and inhibits cell proliferation in vitro. Implantation of these VDR knockdown cells into the mammary fat pad （MDA-MB-231）, subcutaneously （PC3） or intra-tibially （both cell lines） in immune-incompetent nude mice resulted in reduced tumor growth associated with increased apoptosis and reduced cell proliferation compared with controls. These growth-retarding effects of VDR knockdown occur in the presence and absence of vitamin D and are independent of whether cells were grown in bone or soft tissues. Transcriptome analysis of VDR knockdown and non-target control cell lines demonstrated that loss of the VDR was associated with significant attenuation in the Wnt/0-catenin signaling pathway. In particular, cytoplasmic and nuclear β-catenin protein levels were reduced with a corresponding downregulation of downstream genes such as Axin2, Cyclin D1, interleukin-6 （IL-6）, and IL-8. Stabilization of 0-catenin using the GSK-3β inhibitor BIO partly reversed the growth-retarding effects of VDR knockdown. Our results indicate that the unliganded VDR possesses hitherto unknown functions to promote breast and prostate cancer growth, which appear to be operational not only within but also outside the bone environment. These novel functions contrast with the known anti-proliferative nuclear actions of the liganded VDR and may represent targets for new diagnostic and therapeutic approaches in breast and prostate cancer.
文摘目的研究维生素D受体(V D R)基因多态性在中国汉族人群中的分布情况,并探讨V D R基因多态性与2型糖尿病的相关性。方法采用PC R-限制性片段长度多态性方法(R FLP),比较正常中国汉族人群和2型糖尿病患者之间V D R基因多态性等位基因频率和基因型频率的差异。结果V D R基因FokI酶切位点各基因型在2型糖尿病组和正常对照组中的分布差异具有显著统计学意义(χ2=9.993,P=0.007)。两组间等位基因频率总体分布差异有显著性(χ2=7.698,P=0.006)。D M组等位基因f和基因型ff频率明显高于N组,等位基因f与2型糖尿病呈明显正关联(R R=3.9,P<0.05)。结论中国汉族人群中V D R基因多态性与2型糖尿病相关联,等位基因f是2型糖尿病的易感基因。
文摘目的探讨维生素D受体(vitamin D receptor,VDR)基因2个常见多态性位点基因型、等位基因频率与女性高危型人乳头状瘤病毒(human papilloma virus,HPV)感染的相关性。方法采用聚合酶链反应结合测序技术,对138例高危型HPV感染者及126例正常对照者进行VDR基因ApaⅠ、TapⅠ2个SNP位点多态性的检测。结果高危型HPV感染组及对照组VDR基因ApaⅠ、TapⅠ2个SNP位点多态性分布频率均符合遗传学的Hardy-Weinberg平衡定律;高危型HPV感染组VDR基因ApaⅠ位点多态性基因型A/A、C/C和A/C的频率分别为5.8%、55.1%和39.1%,对照组分别为14.3%、52.4%和33.3%,经检验,高危型HPV感染组A/A基因型频率低于对照组,差异有统计学意义(χ2=5.345,P=0.021)。高危型HPV感染组VDR基因TapⅠ位点多态性基因型T/T和C/T的频率分别为88.4%和11.6%,对照组分别为85.7%和14.3%,2组TapⅠ位点多态性分布频率差异无统计学意义(P>0.05)。结论VDR基因多态性与高危型HPV感染风险相关。
