Wnt1 and Wnt2b immunodetection of the regenerating tail and comparative ultrastructure of tail spinal cord in the Scincella tsinlingensis / Inmunodetección Wnt1 y Wnt2b de la cola en regeneración y ultraestructura comparativa de la médula espinal de la cola en Scincella tsinlingensis

SUMMARY: The Wnt pathway is essential for the initiation of lizard tail regeneration. The regenerated lizard tails exhibit obvious morphological differences compared to the original ones. The expression of Wnt1 and Wnt2b proteins in the regenerating tail of Scincella tsinlingensis was detected by immunohistochemistry and then comparatively analyzed for ultrastructural changes in the original and regenerated spinal cord. The ependymal layer of the original spinal cord was pseudostratified with multiciliated cells and primary monociliated cells, while the cells of the ependymal layer of the regenerated spinal cord were organized in a monolayer with a few biciliated cells. Immunolocalization indicated that Wnt1 and Wnt2b were mainly distributed in the dermis near the original tail stump, spinal cord, and clot-positive migratory cells during Stage I, 0-1 days post-amputation (dpa). Wnt1 and Wnt2b were predominantly detected in the epaxial and hypaxial musculature near the original tail stump, wound epithelium, and spinal cord in the original tail during Stage II, 1-7 dpa. Mesenchymal cells and wound epithelium showed immunostaining during Stage III and IV, 7-15 dpa. The ependymal tubes contained these signaling proteins during Stage V and VI, 20- 30 dpa. Labeling was mainly observed in nearby regenerative blood vessels, ependymal cells, epaxial and hypaxial musculature in the apical epithelial layer (AEC) after 45-160 dpa. These findings indicated that Wnt1 and Wnt2b proteins presented primarily in regenerating epidermis and nerve tissues were a critical signal for tail regeneration in S. tsinlingensis.

RESUMEN: La vía Wnt es esencial para el inicio de la regeneración de la cola del lagarto. Las colas de lagarto regeneradas exhiben diferencias morfológicas obvias en comparación con las originales. La expresión de las proteínas Wnt1 y Wnt2b en la cola en regeneración de Scincella tsinlingensis se detectó mediante inmunohistoquímica y luego se analizaron comparativamente los cambios ultraestructurales en la médula espinal original y regenerada. La capa ependimaria de la médula espinal original se pseudoestratificó con células multiciliadas y células monociliadas primarias, mientras que las células de la capa ependimaria de la médula espinal regenerada se organizaron en monocapa con algunas células bicilicadas. La inmunolocalización indicó que Wnt1 y Wnt2b se distribuyeron principalmente en la dermis cerca del muñón de la cola original, la médula espinal y las células migratorias positivas en el coágulo durante la Etapa I, 0-1 días después de la amputación (dpa). Wnt1 y Wnt2b se detectaron predominantemente en la musculatura epaxial e hipaxial cerca del muñón de la cola original, el epitelio de la herida y la médula espinal en la cola original durante la Etapa II, 1-7 dpa. Las células mesenquimales y el epitelio de la herida mostraron inmunomarcaje durante la Etapa III y IV, 7- 15 dpa. Los tubos ependimarios contenían estas proteínas de señalización durante la Etapa V y VI, 20-30 dpa. El marcaje se observó principalmente en vasos sanguíneos regenerativos cercanos, células ependimarias, musculatura epaxial e hipaxial en la capa epitelial apical (AEC) después de 45-160 dpa. Estos hallazgos indicaron que las proteínas Wnt1 y Wnt2b están presentes principalmente en la epidermis en regeneración y en los tejidos nerviosos y eran una señal crítica para la regeneración de la cola en S. tsinlingensis.

Effects of Porphyromonas gingivalis injected through tail vein on the expressions of biomarkers in neural stem cells and neurons of wild-type rats hippocampus / 中华口腔医学杂志

Objectives: To study the effects of Porphyromonas gingivalis (Pg) injected through tail vein on the molecular expression levels of biomarkers of neural stem cells (NSC) and neurons in the hippocampus of wild-type adult rats, and the effects on hippocampal neurogenesis. Methods: Eighteen male Sprague-Dawley (SD) rats were randomly divided into 3 groups based on the table of random numbers (n=6 in each group). In low-intensity group and high-intensity group, rats were injected intravenously through tail vein with 200 μl Pg ATCC33277 [1.0×103 and 1.0×108 colony forming unit (CFU), respectively] 3 times per week for 8 weeks. In the sham group, 200 μl of phosphate buffer saline (PBS) was given instead. Behavioral tests: the navigation and the exploration tests using Morris water maze (MWM) were applied to evaluate learning and memory ability of rats. Immunohistochemistry was performed to detect cells positively expressing nestin, doublecortin (DCX) and neuronal nuclei (NeuN) in the subgranular zone (SGZ) of rats in each group. Western blotting was used to evaluate the expression levels of nestin, DCX and NeuN in rat hippocampus. Results: Learning and memory abilities: on day 5 of navigation test, the lagency time was 22.83 (16.00, 38.34) s in the high-intensity group, significantly longer than the sham group [5.59 (5.41, 6.17) s] (t=-11.17, P<0.001). There were no significant differences between the low-intensity group [9.85 (8.75, 21.01) s] and the sham group (t=-6.83, P=0.080). Results in the exploration test showed that, in the high-intensity group, the number of fime crossing over the previous platform area within 60 s was 1.50 (1.00, 2.00), significantly less than the sham group [4.00 (2.75, 4.00)] (t=9.75, P=0.003); no significant differences between the low-intensity group [2.50 (2.00, 3.00)] and the sham one (t=4.50, P=0.382). Immunohistochemistry showed that the nestin+ cell density in the low-intensity group [(35.36±4.32) cell/mm2] and high-intensity group [(26.51±5.89) cell/mm2] were significantly lower than the sham group [(59.58±14.15) cell/mm2] (t=24.21, P=0.018; t=33.07, P=0.005); as for the mean absorbance of DCX+ cells, the low-intensity group (0.007±0.002) and the high-intensity group (0.006±0.002) were significantly lower than the sham group (0.011±0.001) (t=0.004, P=0.018; t=0.006, P=0.005); compared with the sham group [(1.13±0.14)×103 cell/mm2], the density of NeuN+ neurons in the high-intensity group [(0.75±0.08)×103 cell/mm2] was significantly reduced (t=0.38, P=0.017), and was not significantly changed in the low-intensity group [(0.88±0.19)×103 cell/mm2] (t=0.25, P=0.075). Western blotting results showed that, compared with the sham group, the expression levels of nestin, DCX, and NeuN were significantly reduced in the high-intensity group (t=0.74, P<0.001; t=0.18, P=0.014; t=0.35, P=0.008), but were not statistically changed in the low-intensity group (t=0.18, P=0.108; t=0.08, P=0.172; t=0.19, P=0.077). Conclusions: Pg injected through tail vein may reduce learning and memory abilities of wild-type rats, and may reduce the number of nestin, DCX, and NeuN-positive cells, and the protein expression levels of the above molecules in the hippocampus.

Effect of dietary nutrition on tail fat deposition and evaluation of tail-related genes in fat-tailed sheep

BACKGROUND: The effects of dietary nutrition on tail fat deposition and the correlation between production performance and the Hh signaling pathway and OXCT1 were investigated in fat-tailed sheep. Tan sheep were fed different nutritional diets and the variances in tail length, width, thickness and tail weight as well as the mRNA expression of fat-related genes (C/EBPα, FAS, LPL, and HSL) were determined in the tail fat of sheep at three different growth stages based on their body weight. Furthermore, the correlations between tail phenotypes and the Hedgehog (Hh) signaling pathway components (IHH, PTCH1, SMO, and GLI1) and OXCT1 were investigated. RESULTS: C/EBPα, FAS, LPL, and HSL were expressed with differences in tail fat of sheep fed different nutritional diets at three different growth stages. The results of the two-way ANOVA showed the significant effect of nutrition, stage, and interaction on gene expression, except the between C/EBPα and growth stage. C/EBPα, FAS, and LPL were considerably correlated with the tail phenotypes. Furthermore, the results of the correlation analysis demonstrated a close relationship between the tail phenotypes and Hh signaling pathway and OXCT1. CONCLUSIONS: The present study demonstrated the gene-level role of dietary nutrition in promoting tail fat deposition and related tail fat-related genes. It provides a molecular basis by which nutritional balance and tail fat formation can be investigated and additional genes can be identified. The findings of the present study may help improve the production efficiency of fat-tailed sheep and identify crucial genes associated with tail fat deposition.

Variaciones en el contenido de calcio, fosfato, magnesio y sodio en huesos de ratas macho castradas / Variations in the contents of calcium, phosphate, magnesium and sodium in bones of castrated male rats

Un grupo de ratas macho Holtzman de tres meses de edad fue bilateralmente castrado (TX). Otro grupo igual (control) fue sometido a operación simulada. La alimentación fue ad libitum para el grupo control y restringida para el TX. A los 30,60, 90, 120 y 150 días de la castración se seccionó un segmento de cola a todas las ratas. A los 150 días de realizó densitometría mineral ósea (BMD) a todos los animales, se sacrificaron y se extrajeron los fémures izquierdos. En los huesos de la cola (HC) y en los fémures se determinaron las cenizas y las concentraciones de Ca++, PO4(-3), Mg++ y Na+. En los HC, a los 30 días disminuyeron las cenizas y la concentración de Ca++, PO4(-3), (p<0,05) en las ratas TX. A los 60 días las cenizas y todos los iones analizados habían disminuido (p<0,05 y p<0,025) en las ratas TX, descenso que se profundizó más adelante. Las disminuciones más significativas en los HC se observaron para el Ca++ a los 90 días (p<0,005); para las cenizas a los 120 días (p<0,005); para el fosfato, el Mg++ y el Na+ a los 150 días (p<0,005). A los 150 días las cenizas y las concentraciones de los iones analizados no mostraron diferencias estadísiticamente entre los HC y los fémures. La BMD a los 150 días disminuyó en el grupo TX (p<0,05). No hubo diferencias estadísticas entre los pesos corporales de los dos grupos de ratas durante toda la experiencia. Los resultados sugieren que en ratas macho castradas a los tres meses de edad, los contenidos de calcio, fosfato, magnesio y sodio y las cenizas en HC son buenos indicadores de la pérdida de masa ósea, a partir de los 30 y 60 días de la castración. Además, a los 150 días la desmineralización ósea se refleja cuantitativamente igual en fémur que en HC, y el descenso en la concentración de los iones óseos sería mejor indicador de pérdida de masa ósea que la disminución de BMD.