Abdel-Wanis M E, Tsuchiya H
Orthopaedic Department, Faculty of Medicine, Kanazawa University, Kanazawa, Japan.
Med Hypotheses. 2002 Nov;59(5):552-4. doi: 10.1016/s0306-9877(02)00251-7.
Fibrous dysplasia of bone might be monostotic, polystotic, or occurs as a part of McCune-Albright syndrome and Jaffe-Lichtenstein syndrome. Activating mutations of GNAS1 gene was identified in patients with fibrous dysplasia. However, fibrous dysplasia might occur in the absence of these mutations and fibrous dysplastic tissue was produced in vitro by the effects of excess exogenous cAMP on human osteogenic cells. It was proved that the fibrous dysplastic tissue is deficient in bone sialoprotein. Melatonin deficiency might be hypothesized in syndromes associated with fibrous dysplasia or formation of fibrous dysplasia-like tissue. The receptor RZR/ROR is the nuclear receptor of melatonin and the human bone sialoprotein gene contains a RZR/ROR response element. It was supposed that binding of melatonin to its membrane receptors results in changes in the levels of activity of nuclear cAMP that lead to alteration of expression of bone sialoprotein. Also, melatonin deficiency might increase cAMP in bone through its effect on prostaglandins of the E group. Further, melatonin deficiency might explain precocious puberty in cases of McCune-Albright syndrome. We might hypothesize that melatonin deficiency might play a role in development of fibrous dysplasia in some cases.
骨纤维发育不良可能是单骨型、多骨型，或作为McCune - Albright综合征和Jaffe - Lichtenstein综合征的一部分出现。在骨纤维发育不良患者中鉴定出GNAS1基因的激活突变。然而，骨纤维发育不良可能在没有这些突变的情况下发生，并且过量外源性环磷酸腺苷（cAMP）对人成骨细胞的作用可在体外产生纤维发育不良组织。已证明纤维发育不良组织中骨唾液蛋白缺乏。在与骨纤维发育不良或纤维发育不良样组织形成相关的综合征中可能存在褪黑素缺乏的假设。受体RZR/ROR是褪黑素的核受体，人骨唾液蛋白基因含有一个RZR/ROR反应元件。据推测，褪黑素与其膜受体结合会导致核cAMP活性水平发生变化，进而导致骨唾液蛋白表达改变。此外，褪黑素缺乏可能通过其对E组前列腺素的作用增加骨中的cAMP。此外，褪黑素缺乏可能解释McCune - Albright综合征病例中的性早熟。我们可以假设，在某些情况下，褪黑素缺乏可能在骨纤维发育不良的发生中起作用。
