Quality of life in Japanese women with postmenopausal osteoporosis treated with raloxifene and vitamin D: post hoc analysis of a postmarketing study.

OBJECTIVES: To assess the effect of active vitamin D3 on quality of life (QOL) and pain in raloxifene-treated Japanese women with postmenopausal osteoporosis. RESEARCH DESIGN AND METHODS: This is a post hoc analysis of a previous prospective postmarketing observational study conducted without a comparator group. This study was conducted in 60 Japanese hospitals from September 2007 to February 2009. We compared changes from baseline in QOL and pain in patients receiving raloxifene plus active vitamin D3 with those in patients receiving raloxifene monotherapy at 8 and 24 weeks after treatment. CLINICAL TRIAL REGISTRATION: Japan Pharmaceutical Information Center (JapicCTI-070465). MAIN OUTCOME MEASURES: QOL and pain were assessed using Short Form-8 (SF-8), European Quality of Life Instrument 5 Dimensions (EQ-5D), Japanese Osteoporosis Quality of Life Questionnaire (JOQOL), visual analogue pain scales (VAS pain), and pain frequency scores. RESULTS: A total of 506 patients were included in the post hoc analysis. Both raloxifene monotherapy (RLX, n = 354) and active vitamin D3 cotreatment (COMBI, n = 152) significantly improved QOL and reduced pain from the baseline at Week 8 and Week 24. The COMBI group had significantly greater improvements in JOQOL total score and activity of daily living (total) domain at Week 24 and last observation carried forward (LOCF) than the RLX group. The COMBI group also had significantly greater improvements in SF-8 domains of general health (at Week 8, Week 24, and LOCF), role physical (at Week 24 and LOCF), and mental health (at LOCF) than the RLX group. The COMBI group also had significantly greater reduction in VAS pain at LOCF than the RLX group (mean [SD]: RLX = -0.99 [2.72], COMBI = -1.54 [2.21], P = 0.042). CONCLUSIONS: Active vitamin D3 supplementation to raloxifene treatment for 24 weeks may have additional benefits in improving QOL and relieving pain in Japanese women with postmenopausal osteoporosis.

ATF4 mediation of NF1 functions in osteoblast reveals a nutritional basis for congenital skeletal dysplasiae.

The transcription factor ATF4 enhances bone formation by favoring amino acid import and collagen synthesis in osteoblasts, a function requiring its phosphorylation by RSK2, the kinase inactivated in Coffin-Lowry Syndrome. Here, we show that in contrast, RSK2 activity, ATF4-dependent collagen synthesis, and bone formation are increased in mice lacking neurofibromin in osteoblasts (Nf1(ob)(-/-) mice). Independently of RSK2, ATF4 phosphorylation by PKA is enhanced in Nf1(ob)(-/-) mice, thereby increasing Rankl expression, osteoclast differentiation, and bone resorption. In agreement with ATF4 function in amino acid transport, a low-protein diet decreased bone protein synthesis and normalized bone formation and bone mass in Nf1(ob)(-/-) mice without affecting other organ weight, while a high-protein diet overcame Atf4(-/-) and Rsk2(-/-) mice developmental defects, perinatal lethality, and low bone mass. By showing that ATF4-dependent skeletal dysplasiae are treatable by dietary manipulations, this study reveals a molecular connection between nutrition and skeletal development.

Menin suppresses osteoblast differentiation by antagonizing the AP-1 factor, JunD.

Mice null for menin, the product of the multiple endocrine neoplasia type 1 (MEN1) gene, exhibit cranial and facial hypoplasia suggesting a role for menin in bone formation. We have shown previously that menin is required for the commitment of multipotential mesenchymal stem cells into the osteoblast lineage in part by interacting with the bone morphogenetic protein (BMP)-2 signaling molecules Smad1/5, and the key osteoblast transcriptional regulator, Runx2 (Sowa H., Kaji, H., Hendy, G. N., Canaff, L., Komori, T., Sugimoto, T., and Chihara, K. (2004) J. Biol. Chem. 279, 40267-40275). However, menin inhibits the later differentiation of committed osteoblasts. The activator protein-1 (AP-1) transcription factor, JunD, is expressed in osteoblasts and has been shown to interact with menin in other cell types. Here, we examined the consequences of menin-JunD interaction on osteoblast differentiation in mouse osteoblastic MC3T3-E1 cells. JunD expression, assessed by immunoblot, gradually increased during osteoblast differentiation. Stable expression of JunD enhanced expression of the differentiation markers, Runx2, type 1 collagen (COL1), and osteocalcin (OCN) and alkaline phosphatase (ALP) activity and mineralization. Hence, JunD promotes osteoblast differentiation. In MC3T3-E1 cells in which menin expression was reduced by stable menin antisense DNA transfection, JunD levels were increased. When JunD and menin were co-transfected in MC3T3-E1 cells, they co-immunoprecipitated. JunD overexpression increased the transcriptional activity of an AP-1 luciferase reporter construct, and this activity was reduced by co-transfection of menin. Therefore, JunD and menin interact both physically and functionally in osteoblasts. Furthermore, menin overexpression inhibited the ALP activity induced by JunD. In conclusion, the data suggest that menin suppresses osteoblast maturation, in part, by inhibiting the differentiation actions of JunD.