Immunolocalization of ß-catenin and Lef-1 during postnatal hair follicle development in mice.

It is well recognized that the Wnt pathway, in which ß-catenin and Lef-1 are important factors, is associated with many physiological processes, including embryogenesis and postnatal development. The Wnt pathway also plays a critical role in the development of skin. It regulates the formation of the dorsal dermis and epidermal appendages in the skin and the activity of epithelial stem cells. In this study, we investigated the presence and localization of ß-catenin and Lef-1 in murine hair follicles through the first postnatal month, which encompasses the first hair cycle in mice, using Western blotting and immunohistochemistry. Our results show that ß-catenin and Lef-1 are expressed during all stages in a hair cycle, most strongly in the anagen and weakly in the catagen and telogen phases. The results also suggest that the ß-catenin-Lef-1 complex may regulate hair follicle cycling. This process will be of considerable interest to future studies.

[Effect of schisandrin B on lung mRNA expression of transforming growth factor-beta1 signal transduction molecule in rat lungs exposed to silica].

OBJECTIVE: To investigate the effects of schisandrin B (Sch-B) on expression of transforming growth factor-beta1 (TGF-beta1) and signal transduction molecule mRNA in rat lungs exposed to SiO2, and explore the intervention mechanism of Sch-B on pulmonary fibrosis induced by SiO2. METHODS: Ninety six Wistar rats were randomly divided into control (normal saline) group, SiO2 group and SiO2 plus Sch-B group. The rats were exposed to SiO2 by direct tracheal instillation to establish the silicotic animal models. SiO2 group and SiO2 plus Sch-B group were treated with 1 ml SiO2 (50 mg/ml) for each rat From the first day after model establishment, SiO2 plus Sch-B group were orally given Sch-B (80 mg/kg) a day, control group and silica group were orally given olive oil. On the 3rd, 7th, 14th and 28th days after treatment, 8 rats in each group were sacrificed and samples were collected. The histo-pathological examination of lung was performed by HE staining. The expression levels of TGF-beta1, TGF-betaR II and Smad4 mRNA in the lung tissues were detected by RT-PCR. RESULTS: The results of histo-pathological examination showed that in SiO2 group, lung tissues were injured obviously; the alveolar inflammation with alveolus interval edema and inflammation cell infiltration appeared on the 3rd and 7th days; the alveolus interval became thicker, became thicker, fibroblast and collagen matrix increased markedly on 14th day; the alveolar structure was damaged, alveolar wall thickened obviously, collagen aggravation and pulmonary fibrosis displayed on 28th day. The alveolar inflammation and pulmonary fibrosis in SiO2 plus Sch-B group were significantly less than those in SiO2 group. The expressions levels of TGF-beta1 TGF-betaR II and Smad4 mRNA (TGF-1beta: 1.03 +/- 0.31, 1.33 +/- 0.39,1.08 +/- 0.26, 0.82 +/- 0.16, TGF-betaR II: 0.65 +/- 0.11, 0.80 +/- 0.16, 0.83 +/- 0.24, 0.62 +/- 0.15, Smad4:0.87 +/- 0.15, 0.68 +/- 0.11, 0.78 +/- 0.19, 0.30 +/- 0.08) in SiO2 group were significantly higher than those in the control group (TGF-beta1:0.59 +/- 0.22, 0.55 +/- 0.25, 0.56 +/- 0.20, 0.55 +/- 0.12, TGR-betaR II :0.28 +/- 0.13, 0.31 +/- 0.15, 0.34 +/- 0.15, 0.27 +/- 0.09, Smad4:0.23 +/- 0.11, 0.40 +/- 0.12, 0.39 +/- 0.12, 0.18 +/- 0.06) (P < 0.01 or P < 0.05), but the expression level of TGF-beta1 mRNA was the highest on the 7th day. The expression levels of TGF-beta1 and Smad4 mRNA (TGF-beta1:0.68 +/- 0.28, 0.88 +/- 0.25, 0.75 +/- 0.11, 0.61 +/- 0.14,Smad4:0.25 +/- 0.12, 0.45 +/- 0.09, 0.44 +/- 0.07, 0.21 +/- 0.04) in SiO2 plus Sch-B group were significantly lower than those in SiO2 group (P < 0.01 or P < 0.05 ), but there were no significant differences of the TGFbetaR II mRNA expression levels between SiO2 group and SiO2 plus Sch-B group. CONCLUSION: Sch-B can reduce the pulmonary fibrosis induced by SiO2 through inhibition of the mRNA express of TGF-beta1 and Smad4 in the lung tissue, modulating the TGF-beta1/Smad4 signal transduction pathway and inhibiting the target gene activation.

[Effect of Schisandrin B on mitogen-activated protein kinases and nuclear factor-kappaB in rat lungs exposed to silica].

OBJECTIVE: To investigate the effect of Schisandrin B on mitogen-activated protein kinases (MAPKs) and nuclear factor-KB in rat lungs exposed to silica. METHODS: 92 Wistar rats were randomly divided into four groups: Control (20), Silica (30), Sch-B treated 1 group (Sch-B 1) (24) and Sch-B treated 2 group (Sch-B 2)(18). Silicotic animal models received an intratracheal injection of silica. From the first day after model establishment, rats in Sch-B 1 were treated intragastrically with Sch-B at a dose of 80 mg/kg, once daily. From the 8th day after model establishment, rats in Sch-B 2 were treated intragastrically with Sch-B at a dose of 80 mg/kg, once daily. 6 rats in Sch-B 1 were sacrificed on the 3rd, 7th, 14th and 21st days, and 6 rats in Sch-B 2 on the 14th, 21st and 28th days, 4 Control rats, 6 silica rats on the 3rd, 7th, 14th, 21st and 28th days accordingly, lungs were collected. Right lung for protein extraction, the phosphorylation level of extracellular signal-regulated protein kinase, c-Jun NH2-terminal amino kinase and p38 in lungs were detected by Western Blot. Left lung was fixed by neutral formalin. The ratio of nuclear transfer of NF-kappaB was evaluated by immunohistochemistry. RESULTS: 1. The phosphorylation level of ERK1/2 in Sch-B 1 on 3rd, 7th, 14th and 21st (0.974 +/- 0.169, 0.987 +/- 0.149, 0.920 +/- 0.092 and 0.884 +/- 0.078) and Sch-B 2 on 14th, 21st and 28th (1.012 +/- 0.050, 1.167 +/- 0.083 and 1.002 +/- 0.060) were significantly lower than in silica groups P < 0.05 or P < 0.01); The phosphorylation level of JNK1 in Sch-B 1 reached its summit on 7th day (P < 0.01 ), and that in Sch-B 2 on 14th, 21st and 28th (0.882 +/- 0.064, 0.802 +/- 0.061, 0.792 +/- 0.015) was lower than Silica groups at every time points (P < 0.01); The phosphorylation level of p-p38 in Sch-B 1 was higher than silica group on 3rd day (0.309 +/- 0.045) and lower on 7th, 14th and 21st day, but that in Sch-B 2 were lower and lower. 2. The ratio of nuclear transfer of NF-KB in Sch-B 1 on 3rd, 7th, 14th and 21st [(13.54 +/- 5.36)%, (21.01 +/- 6.43)%, (30.55 +/- 6.44)%, (37.39 +/- 9.32)%] was lower than that in silica groups (P < 0.01); but in Sch-B 2, it was lower than silica group on the 21st [(44.33 +/- 22.88)%] and higher on the 28th day [(58.52 +/- 14.57)%] (P < 0.01). CONCLUSIONS: Sch-B has some depression effects on the activation of MAPKs in rat lungs exposed to silica. The nuclear transfer of NF-kappaB could be suppressed by Sch-B in the initial stage of rat lungs exposed to silica. Protection of Sch-B against silica induced lung injury in rats may be via MAPKs and NF-kappaB signal transduction pathway.