Treatment with 1,25-dihydroxyvitamin D3 reduces impairment of human osteoblast functions during cellular aging in culture
Treatment with 1,25-dihydroxyvitamin D3 reduces impairment of human osteoblast functions during cellular aging in culture
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DOI：
10.1002/1097-4652(200002)186:2
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发表时间：
2001-02-01
影响因子：
5.6
通讯作者：
Kassem, M
中科院分区：
文献类型：
--
作者：
Kveiborg, M;Rattan, SIS;Kassem, M
对各种激素如1，25-二羟基维生素D-3（骨化三醇）的充分反应是最佳成骨细胞功能的先决条件。我们以前的特点是几个人二倍体成骨细胞系，表现出典型的体外老化的特点，在长期传代培养。为了研究成骨细胞功能的体外年龄相关变化，我们比较了早期传代（90%寿命完成）成骨细胞特异性基因的组成型mRNA水平。我们发现，与早期传代细胞相比，体外衰老晚期传代细胞中碱性磷酸酶（AP：68%）、骨钙素（OC：67%）和I型胶原（科尔：76%）的mRNA水平显着降低，这表明体外成骨细胞功能与年龄相关。我们假设，降低成骨细胞的功能与体外老化是由于受损的骨化三醇已知是重要的成骨细胞的生物活性的调节反应。因此，我们研究了维生素D受体（VDR）系统的变化和骨化三醇治疗成骨细胞在体外老化过程中的反应。我们发现，无论是稳态mRNA水平或蛋白质水平的VDR的量没有变化，随着体外成骨细胞年龄的增加和VDR定位，核转位和DNA结合活性的检查显示没有在体外年龄相关的变化。此外，骨化三醇（10（-8）M）处理早期传代成骨细胞抑制其增殖57 +/- 1%，并刺激AP（1.7 +/- 0.1倍）和OC（1.8 +/- 0.2倍）的稳态mRNA水平。同样，骨化三醇处理增加了晚期传代成骨细胞中AP（1.7 /- 0.2倍）和OC（3.0 +/- 0.3倍）的mRNA水平。因此，体外衰老的成骨细胞保持其对骨化三醇的反应性，并且通过骨化三醇治疗可以逆转一些在体外观察到的成骨细胞功能的生物标志物的年龄相关性降低。J.细胞。186：298-306，2001。(C)2001 Wiley-Liss，Inc.
Adequate responses to various hormones, such as 1,25-dihydroxyvitamin D-3 (calcitriol) are a prerequisite for optimal osteoblast functions. We have previously characterized several human diploid osteoblastic cell lines that exhibit typical in vitro aging characteristics during long-term subculturing. In order to study in vitro age-related changes in osteoblast functions, we compared constitutive mRNA levels of osteoblast-specific genes in early-passage (90% lifespan completed). We found a significant reduction in mRNA levels of alkaline phosphatase (AP: 68%), osteocalcin (OC: 67%), and collagen type I (Coll: 76%) in in vitro senescent late-passage cells compared to early-passage cells, suggesting an in vitro age-related impairment of osteoblast functions. We hypothesized that decreased osteoblast functions with in vitro aging is due to impaired responsiveness to calcitriol known to be important for the regulation of biological activities of the osteoblasts. Thus, we examined changes in vitamin D receptor (VDR) system and the osteoblastic responses to calcitriol treatment during in vitro osteoblast aging. We found no change in the amount of VDR at either steady state mRNA level or protein level with increasing in vitro osteoblast age and examination of VDR Localization, nuclear translocation and DNA binding activity revealed no in vitro age-related changes. Furthermore, calcitriol (10(-8)M) treatment of early-passage osteoblastic cells inhibited their proliferation by 57 +/- 1% and stimulated steady state mRNA levers of AP (1.7 +/- 0.1-fold) and OC (1.8 +/- 0.2-fold). Similarly, calcitriol treatment increased mRNA levels of AP (1.7 /- 0.2-fold) and OC (3.0 +/- 0.3-fold) in late-passage osteoblastic cells. Thus, in vitro senescent osteoblastic cells maintain their responsiveness to calcitriol and some of the observed in vitro age-related decreases in biological markers of osteoblast functions can be reverted by calcitriol treatment. J. Cell. Physiol. 186:298-306, 2001. (C) 2001 Wiley-Liss, Inc.