Expression of the homeobox proteins Dlx-5 and TLX1 during the development of cat testis / Expresión de las proteínas homeobox Dlx-5 y TLX1 durante el desarrollo del testículo de gato

SUMMARY: Recent studies have shown that homeobox proteins play an important role in the formation and development of tissues and organs in the embryonic period. In our study, the distribution of Dlx-5 and TLX proteins, which are members of the homeobox family, in the testis, epididymis and ductus deferens ducts of some cat breeds were investigated. For this purpose, in the study, 18 testes younger than six months (immature) and older than one year (mature) were examined under a light microscope using an immunohistochemical method (indirect streptavidin-biotin complex). While it was determined that Dlx-5 and TLX1 proteins were expressed at varying levels in cells in immature and mature cat testicles, epithelial cells of ductus epididymis and ductus deferens, and smooth muscle cells of ductus deferens, no differences were observed between cat breeds. Dlx-5 immunoreactivity was more intense in the testes, epididymis and deferens ducts of immature and mature compared to TLX1. These results suggested that both proteins play important roles in the development of male feline genital organs and in the secretion and differentiation of cells, and also further observation of Dlx-5 expression suggested that this protein may be more effective than TLX1 in testicular development and physiological processes.

RESUMEN: Estudios recientes han demostrado que las proteínas homeobox juegan un papel importante en la formación y desarrollo de tejidos y órganos en el período embrionario. En nuestro estudio, se investigó la distribución de las proteínas Dlx-5 y TLX, que son miembros de la familia homeobox, en los testículos, en el epidídimo y en los conductos deferentes de algunas razas de gatos. En el estudio fueron examinados, 18 testículos de animales menores de seis meses (inmaduros) y mayores de un año (maduros) bajo un microscopio óptico utilizando un método inmunohistoquímico (complejo indirecto de estreptavidina-biotina). Si bien se determinó que las proteínas Dlx-5 y TLX1 se expresaron en niveles variables en las células de los testículos de gatos inmaduros y maduros, las células epiteliales del epidídimo y del conducto deferente y las células del músculo liso del conducto deferente, no se observaron diferencias entre las razas de gatos. La inmunorreactividad de Dlx-5 fue más intensa en los testículos, epidídimo y conductos deferentes de gatos inmaduros y maduros en comparación con TLX1. Estos resultados sugieren que ambas proteínas tienen un rol importante en el desarrollo de los órganos genitales felinos masculinos y en la secreción y diferenciación de células, y también la observación de la expresión de Dlx-5 sugirió que esta proteína puede ser más efectiva que TLX1 en el desarrollo testicular y en los procesos fisiológicos.

Changes of distal-less homeobox genes 5 and Msh homeobox 1 in a rat model of bisphosphonate related osteonecrosis of the jaw / 中华口腔医学杂志

Objective@#To further study the effects of distal-less homeobox gene 5 (Dlx-5) and Msh homeobox 1 (Msx-1) in the pathogenic mechanism of bisphosphonate related osteonecrosis of the jaw (BRONJ) .@*Methods@#Twenty-four SD rats were divided into two groups, the experimental group was injected intraperitoneally with zoledronic acid for 12 weeks (0.2 mg/kg, three times a week), and the control group was injected with saline solution for 12 weeks. The first mandibular molars were extracted after 12 weeks. All of the animals were sacrificed eight weeks after teeth extraction. The BRONJ was diagnosed by gross observation, X-ray examination and histopathlolgical examination. Through real-time PCR, the expression level of Dlx-5 and Msx-1 were detected in the mandible of BRONJ samples and normal samples.@*Results@#X-ray examination and histopathlolgical analysis showed the presence of BRONJ. The results of real-time PCR showed that the expression levels of Dlx-5 were increased (P=0.001) and the expression level of Msx-1 was decreased (P=0.001) in the experimental group compared with the control group.@*Conclusions@#Dlx-5 and Msx-1 genes play roles in the pathogenic mechanism of BRONJ.

Differential Expression of STATs and Its Function in Osteogenesis of Mesenchymal Stem Cells / 대한정형외과연구학회지

PURPOSE: To investigate the role of STAT5 during osteogenesis differentiation of human mesenchymal stem cells(hMSC). MATERIALS AND METHODS: To assess the expression pattern of STATs during osteogenic differentiation, we performed western blot analysis and RT-PCR. By RNA interference, we have performed effect of STAT5A and STAT5B in osteogenesis. As a result of Luciferase assay, the promoter activity of DLX5 was decreased by STAT5A. RESULTS: To assess the expression pattern of STATs during osteogenic differentiation, we have performed western blot and RT-PCR after 14 day differentiation period. STAT1, 2, 3 and 4 showed no change in expression level during differentiation, while STAT5A and STAT5B displayed steady increase compared to the control. When STAT5A was knock down, the level of osteogenesis was increased. The transcriptional activity of DLX5 was decreased about 70% by STAT5A. CONCLUSION: The expression of STAT5A and STAT5B increased during osteogenesis of hMSC. Also, we shown that STAT5A regulated the transcriptional activity of DLX5. These results indicate that STAT5A acts as a pivotal transcription factor in osteogenesis of hMSC.

Dlx3 and Dlx5 Inhibit Adipogenic Differentiation of Human Dental Pulp Stem Cells

Dlx3 and Dlx5 are homeobox domain proteins and are well-known regulators of osteoblastic differentiation. Since possible reciprocal relationships between osteogenic and adipogenic differentiation in mesenchymal stem cells exist, we examined the regulatory role of Dlx3 and Dlx5 on adipogenic differentiation using human dental pulp stem cells. Over-expression of Dlx3 and Dlx5 stimulated osteogenic differentiation but inhibited adipogenic differentiation of human dental pulp stem cells. Dlx3 and Dlx5 suppressed the expression of adipogenic marker genes such as C/EBPalpha, PPARgamma, aP2 and lipoprotein lipase. Adipogenic stimuli suppressed the mRNA levels of Dlx3 and Dlx5, whereas osteogenic stimuli enhanced the expression of Dlx3 and Dlx5 in 3T3-L1 preadipocytes. These results suggest that Dlx3 and Dlx5 exert a stimulatory effect on osteogenic differentiation of stem cells through the inhibition of adipogenic differentiation as well as direct stimulation.

Rat Dlx5 is expressed in the subventricular zone and promotes neuronal differentiation

The molecular mechanisms and potential clinical applications of neural precursor cells have recently been the subject of intensive study. Dlx5, a homeobox transcription factor related to the distal-less gene in Drosophila, was shown to play an important role during forebrain development. The subventricular zone (SVZ) in the adult brain harbors the largest abundance of neural precursors. The anterior SVZ (SVZa) contains the most representative neural precursors in the SVZ. Further research is necessary to elucidate how Dlx5-related genes regulate the differentiation of SVZa neural precursors. Here, we employed immunohistochemistry and molecular biology techniques to study the expression of Dlx5 and related homeobox genes Er81 and Islet1 in neonatal rat brain and in in vitro cultured SVZa neural precursors. Our results show that Dlx5 and Er81 are also highly expressed in the SVZa, rostral migratory stream, and olfactory bulb. Islet1 is only expressed in the striatum. In cultured SVZa neural precursors, Dlx5 mRNA expression gradually decreased with subsequent cell passages and was completely lost by passage four. We also transfected a Dlx5 recombinant plasmid and found that Dlx5 overexpression promoted neuronal differentiation of in vitro cultured SVZa neural precursors. Taken together, our data suggest that Dlx5 plays an important role during neuronal differentiation.