{'fraction_non_alphanumeric': 0.05698529411764706, 'fraction_numerical': 0.050551470588235295, 'mean_word_length': 6.025806451612903, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
1α,25‐Dihydroxyvitamin D3 Regulates the Expression of Membrane‐Type Matrix Metalloproteinase‐1 in Normal Human Osteoblast‐like Cells

Recently, membrane‐type matrix metalloproteinase‐1 (MT1‐MMP) was identified, and found that it can activate proMMP‐2 on the cell membrane, degrade bone matrix, and participate in bone formation. Since bone is a target tissue of 1α,25‐dihydroxyvitamin D3 [1α,25(OH)2D3], in the present study we observed the effects of 1α,25(OH)2D3 on MT1‐MMP expression, and proMMP‐2 activation in normal human osteoblast‐like cells (hOB). Western immunoblots showed 1α,25(OH)2D3 time and dose dependently stimulated MT1‐MMP production. By ELISA, we found that the activation of proMMP‐2 in cultures of hOB was intensified by 1α,25(OH)2D3. Our studies suggest that 1α,25(OH)2D3 induces MMP‐2 activation in part by up‐regulating MT1‐MMP expression, and since MT1‐MMP plays a role in bone metabolism, the induction of MT1‐MMP levels by 1α,25(OH)2D3 in hOB cells may contribute to a new mechanism by which 1α,25(OH)2D3 promotes bone formation and stimulates bone resorption.