Recent studies have demonstrated that some microRNAs (miRNAs) inhibit bone formation by inhibiting the translation of specific genes. Several in vitro studies have suggested that miR-23a inhibits osteogenic differentiation by suppressing the translation of Runx2, a transcription factor essential for osteoblastogenesis, and of Satb2, a member of the special AT-rich binding protein family. In the present study, we used a gain-of-function approach to determine the roles of miR-23a in bone formation and homeostasis in vivo. The miR-23a transgenic (Tg) mice grew normally and their body size and weight were similar to those of wild-type (WT) littermates. Bone structure and morphology were similar in Tg and WT mice. Furthermore, the numbers of osteoblasts and osteoclasts, as well as their activities in bone were similar between Tg and WT mice. Our results indicate that miR-23 has limited roles in bone formation and maintenance in vivo in mice.

• MeSH
• homeostáza fyziologie   MeSH
• mikro RNA biosyntéza   MeSH
• myši inbrední C57BL MeSH
• myši transgenní MeSH
• myši MeSH
• osteoblasty metabolismus   MeSH
• osteogeneze fyziologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The aim of this study was to examine whether threshold to heat stimuli, and expression of transient receptor potential vanilloid1 (TRPV1) and nerve growth factor (NGF) in dorsal root ganglion (DRG) altered under conditions of long-term limb immobilization. A plastic cast was wrapped around the right limb from the forearm to the forepaw to keep wrist joint at 90° of flexion for 5 weeks. Heat hyperalgesia was tested using the plantar test at 6 h after removing cast. The rats were perfused transcardially with 4 % paraformaldehyde and DRGs were excised at 24 h after removing cast. For size distributions of the TRPV1-IR and NGF-IR neuronal profile, the DRG area measurements over 1000 DRG neurons per animal were measured in each side, on both the immobilized (ipsilateral) and contralateral sides. Ipsilateral withdrawal latency was significantly shorter than contralateral sides. Ipsilateral percentage of immunoreactive neurons in the total DRG neurons was significantly higher than contralateral sides in TRPV1-IR and NGF-IR. Long-term casting induced heat hyperalgesia, and up-regulation and phenotypic change of TRPV1-IR and NGF-IR in DRGs on the immobilized side. These DRG alterations may involve heat hyperalgesia after long-term limb immobilization.

• MeSH
• hyperalgezie genetika   MeSH
• imobilizace * MeSH
• kationtové kanály TRPV biosyntéza   genetika   MeSH
• klouby fyziologie   MeSH
• krysa rodu rattus MeSH
• nervový růstový faktor biosyntéza   MeSH
• neurony účinky léků   MeSH
• práh bolesti účinky léků   MeSH
• spinální ganglia metabolismus   MeSH
• upregulace fyziologie   MeSH
• vysoká teplota škodlivé účinky   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH