| 1. |
Extremely High Expression of Antisense RNA for Wilms' Tumor 1 in Active Osteoclasts: Suppression of Wilms' Tumor 1 Protein Expression during Osteoclastogenesis.
Wilms' tumor 1 (WT1), a zinc-finger transcription regulator of the early growth response family, identified as the product of a tumor suppressor gene of Wilms' tumors, bears potential ability to induce macrophage differentiation in blood cell differentiation. Herein, we examined the involvement of WT1 in the regulation of osteoclastogenesis. We detected a high level of WT1 protein expression in osteoclast precursors; however, WT1 expression was markedly suppressed during osteoclastogenesis. We examined expression of WT1 transcripts in bone tissue by RNA in situ hybridization. We found a high level of antisense transcripts in osteoclasts actively resorbing bone in mandible of newborn rats. Expression of antisense WT1 RNA in mandible was also confirmed by Northern blot analysis and strand-specific RT-PCR. Overexpression of antisense WT1 RNA in RAW-D cells, an osteoclast precursor cell line, resulted in a marked enhancement of osteoclastogenesis, suggesting that antisense WT1 RNA functions to suppress expression of WT1 protein in osteoclastogenesis. High level expression of antisense WT1 RNA may contribute to commitment to osteoclastogenesis, and may allow osteoclasts to maintain or stabilize their differentiation state.. |
| 2. |
Hinoi E., Nakamura Y., Takada S., Fujita H., Iezaki T., Hashizume S., Takahashi S., Odaka Y., Watanabe T., Yoneda Y., Growth differentiation factor-5 promotes brown adipogenesis in systemic energy expenditure., Diabetes, 10.2337/db13-0808, 63, 1, 162-175, 2014.01, Although growth differentiation factor-5 (GDF5) has been implicated in skeletal development and joint morphogenesis in mammals, little is known about its functionality in adipogenesis and energy homeostasis. Here, we show a critical role of GDF5 in regulating brown adipogenesis for systemic energy expenditure in mice. GDF5 expression was preferentially upregulated in brown adipose tissues from inborn and acquired obesity mice. Transgenic overexpression of GDF5 in adipose tissues led to a lean phenotype and reduced susceptibility to diet-induced obesity through increased systemic energy expenditure. Overexpression of GDF5 facilitated the development of brown fat-like cells, called brite or beige cells, along with the expression of uncoupling protein-1 in inguinal subcutaneous white adipose tissue. In mutant mice harboring the dominant-negative GDF5, marked impairment in energy expenditure and thermogenesis was seen under obesogenic conditions. Recombinant GDF5 promoted brown adipogenesis through the mothers against decapentaplegic homolog (Smad) and peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) pathways after activation of bone morphogenetic protein receptor (BMPR). These results suggest that brown adipogenesis and energy homeostasis are both positively regulated by the GDF5/BMPR/Smad/PGC-1α signaling pathway in adipose tissues. Modulation of these pathways might be an effective therapeutic strategy for obesity and type 2 diabetes.. |
| 3. |
Nakamura Y.*, Hinoi E.*, Iezaki T., Takada S., Hashizume S., Takahata Y., Tsuruta E., Takahashi S., Yoneda Y., Repression of adipogenesis through promotion of Wnt/ß-catenin signaling by TIS7 up-regulated in adipocytes under hypoxia., BBA Mol. Basis Dis., 10.1016/j.bbadis.2013.03.010, 1832, 8, 1117-1128, 2013.08, Although tetradecanoyl phorbol acetate induced sequence-7 (TIS7) has been identified as a co-activator/repressor of gene transcription in different eukaryotic cells, little attention has been paid to the functionality of TIS7 in adipocytes. Here, we evaluated the possible role of TIS7 in mechanisms underlying the regulation of adipogenesis. TIS7 expression was preferentially up-regulated in white adipose tissues (WAT) of obesity model mice as well as in pre-adipocytic 3T3-L1 cells cultured under hypoxic conditions. TIS7 promoter activity was selectively enhanced by activating transcription factor-6 (ATF6) among different transcription factors tested, while induction of TIS7 by hypoxic stress was markedly prevented by knockdown of ATF6 by shRNA in 3T3-L1 cells. Overexpression of TIS7 markedly inhibited Oil Red O staining and expression of particular adipogenic genes in 3T3-L1 cells. TIS7 synergistically promoted gene transactivation mediated by Wingless-type mouse mammary tumor virus integration site family (Wnt)/β-catenin, while blockade of the Wnt/β-catenin pathway by a dominant negative form of T-cell factor-4 (DN-TCF4) markedly prevented the inhibition of adipogenesis in 3T3-L1 cells with TIS7 overexpression. TIS7 predominantly interacted with β-catenin in the nucleus of WAT in the genetically obese ob/ob mice as well as in 3T3-L1 cells cultured under hypoxic conditions. Both knockdown of TIS7 by shRNA and introduction of DN-TCF4 similarly reversed the hypoxia-induced inhibition of adipogenic gene expression in 3T3-L1 cells. These findings suggest that TIS7 could play a pivotal role in adipogenesis through interacting with β-catenin to promote the canonical Wnt signaling in pre-adipocytes under hypoxic stress such as obesity.. |
| 4. |
Takarada T., Takarada-Iemata M., Takahata Y., Yamada D., Yamamoto T., Nakamura Y., Hinoi E., Yoneda Y., Osteoclastogenesis is negatively regulated by D-serine produced by osteoblasts., J. Cell. Physiol., 227, 3477-3487, 2012.10. |
| 5. |
Takahata Y., Hinoi E., Takarada T., Nakamura Y., Ogawa S., Yoneda Y., Positive regulation by GABA(B) receptor subunit-1 of chondrogenesis through acceleration of nuclear translocation of activating transcription factor-4., J. Biol. Chem., 287, 33293-33303, 2012.09. |
| 6. |
Uno K., Takarada T., Takarada-Iemata M., Nakamura Y., Fujita H., Hinoi E., Yoneda Y., Negative regulation of osteoblastogenesis through downregulation of runt-related transcription factor-2 in osteoblastic MC3T3-E1 cells with stable overexpression of the cystine/glutamate antiporter xCT subunit., J. Cell. Physiol., 226, 2953-2964, 2011.11. |
| 7. |
Takahata Y., Takarada T., Hinoi E., Nakamura Y., Fujita H., Yoneda Y., Osteoblastic GABAB receptors negatively regulate osteoblastogenesis toward disturbance of osteoclastogenesis mediated by receptor activator of nuclear factor-kB ligand in mouse bone., J. Biol. Chem., 286, 32906-32917, 2011.09. |
| 8. |
Takarada-Iemata M., Takarada T., Nakamura Y. Nakatani E., Hori O., Yoneda Y., Glutamate preferentially suppresses osteoblastogenesis than adipogenesis through the cystine/glutamate antiporter in mesenchymal stem cells., J. Cell. Physiol., 226, 652-665, 2011.03. |
| 9. |
Nakamura Y.*, Hinoi E.*, Takarada T., Takahata Y., Yamamoto T., Fujita H., Takada S., Hashizume S., Yoneda Y., Positive regulation by GABABR1 subunit of leptin expression through gene transactivation in adipocytes., PLoS ONE., 6, e20167, 2011.03. |
| 10. |
Uno K., Takarada T., Nakamura Y., Fujita H., Hinoi E., Yoneda Y., A negative correlation between expression profiles of runt-related transcription factor-2 and cystine/glutamate antiporter xCT subunit in ovariectomized mouse bone., J. Pharmacol. Sci., 115, 309-319, 2011.02. |
| 11. |
Nakamura Y.*, Takarada T.*, Kodama A., Hinoi E., Yoneda Y., Predominant promotion by tacrolimus of chondrogenic differentiation to proliferating chondrocytes., J. Pharmacol. Sci., 109, 413-423, 2009.03. |
| 12. |
Takahata Y., Takarada T., Osawa M., Hinoi E., Nakamura Y., Yoneda Y., Differential regulation of cellular maturation in chondrocytes and osteoblasts by glycine., Cell Tissue Res., 333, 91-103, 2008.07. |
