Connexin 43 is Localized in Gizzard Smooth Muscle Cells during Chicken Development.

Smooth muscle cells are widely distributed in the digestive organs of chickens. They exist as single cells, but adhere to each other to function synchronously. In this study, the expression of the gap junction protein connexin 43 (Cx43) in chicken gizzards was investigated at embryonic days (E) 10, E15, and E18. Gizzards have an abundance of smooth muscle cells because of their thick muscle layers, which enable easy analysis of the cells. Morphological observations and expression patterns of smooth muscle markers were confirmed. Next, we observed where the markers were localized in the gizzard tissue at E10, E15, and E18. Finally, the expression pattern of Cx43 in primary cultured smooth muscle cells from E15 gizzards was investigated. The analysis revealed the expression and localization of Cx43 and calponin 1 in the smooth muscle layers, and 3D analysis revealed dynamic changes in the localization pattern of Cx43 from E10 to E15. Cultured smooth muscle cells confirmed that Cx43 was expressed in the cell membrane and cytosol. In conclusion, Cx43 expression was identified in chicken gizzards at E10, E15, and E18, which was localized differently during development. The expression was broad at E10, and became restricted at E15 and E18. Primary culture of smooth muscle cells showed that Cx43 was present in the cell membrane and cytosol. This suggests that Cx43 is actively translated into the cytosol at E10, forming a hexamer, and shuttling the cell membrane to function as a gap junction.

Epigenetic effects induced by the ectopic expression of Pax7 in 3T3-L1.

Although skeletal muscle cells and adipocytes are derived from the same mesoderm, they do not transdifferentiate in vivo and are strictly distinct at the level of gene expression. To elucidate some of the regulatory mechanisms underlying this strict distinction, Pax7, a myogenic factor, was ectopically expressed in 3T3-L1 adipose progenitor cells to perturb their adipocyte differentiation potential. Transcriptome analysis showed that ectopic expression of Pax7 repressed the expression of some adipocyte genes and induced expression of some skeletal muscle cell genes. We next profiled the epigenomic state altered by Pax7 expression using H3K27ac, an activating histone mark, and H3K27me3, a repressive histone mark, as indicators. Our results show that ectopic expression of Pax7 did not result in the formation of H3K27ac at loci of skeletal muscle-related genes, but instead resulted in the formation of H3K27me3 at adipocyte-related gene loci. These findings suggest that the primary function of ectopic Pax7 expression is the formation of H3K27me3, and muscle gene expression results from secondary regulation.

Seed migration after transperineal interstitial prostate brachytherapy with I-125 free seeds: analysis of its incidence and risk factors.

PURPOSE: The purpose of this study was to evaluate the incidence and predictors of seed migration after transperineal interstitial prostate brachytherapy. MATERIALS AND METHODS: From March 2007 to March 2011, 121 patients with stage T1-T2 prostate cancer underwent transperineal interstitial prostate brachytherapy. Pre-planning was performed 3 weeks prior to implantation, and the implants were inserted using the standard parallel needle insertion technique. All patients underwent a series of radiographs [chest radiography, kidney-ureter-bladder (KUB) radiography, and a CT scan] to assess whether seed migration had occurred on postoperative days 1 and 30, and 12 months. RESULTS: Seed migration occurred in 31 (25.6 %) of 121 patients. A total of 51 of 7,883 (0.65 %) implanted seeds migrated. Migration was detected on postoperative day 1 in 16 patients, day 30 in 13 patients and at 12 months in 4 patients (migration occurred at different times in 2 patients). The migrated seeds were found in the lungs, pelvis, heart, mediastinum, kidney, inguinal canal, liver and sacrum. The number of needles was a statistically significant factor in seed migration. CONCLUSIONS: The seeds migrated to many organs. No decrease in the dose administered to the prostate or adverse effects associated with seed migration were noted.