Inhibition of Sonic Hedgehog signaling inhibits fibrous scar formation and adversely affects functional outcome after ischemic brain injury in rats / 南方医科大学学报

OBJECTIVE@#To investigate the effects of inhibiting Sonic Hedgehog (Shh) signaling on fibrous scar formation and functional outcome after ischemic brain injury.@*METHODS@#Adult SD rats were randomized into sham-operated group, middle cerebral artery occlusion (MCAO) and reperfusion (I/R) group, I/R with intraventricular empty adenoviral vector (rAd-NC) injection group, and I/R with adenovirus-mediated Shh knockdown (rAd-ShShh) group. After the treatments, the neurological deficits of the rats were assessed, and the protein and mRNA expressions of fibronectin (Fn), α-SMA, and Shh in the ischemic hemisphere were detected with immunofluorescence assay and qPCR; TUNEL staining was used for detecting neural cell apoptosis. In the cell experiment, primary meningeal fibroblasts isolated from neonatal SD rats were pretreated for 24 h with TGF-β1 or TGF-β1 plus cyclopamine (CYC) before oxygen-glucose deprivation for 150 min followed by reoxygenation for 72 h (OGD/R). CCK-8 assay and scratch test were performed to examine the changes in cell proliferation and migration, and immunofluorescence assay, qPCR and Western blotting were used for detecting cell transformation and the expressions of Shh, α-SMA, and Fn.@*RESULTS@#Cerebral I/R injury significantly increased the protein and mRNA expressions of Shh, α-SMA, and Fn in the ischemic hemisphere of the rats, but their expression levels were significantly lowered by intraventricular injection of rAd-Shshh (P < 0.05), which obviously increased cell apoptosis in the ischemic hemisphere (P < 0.05) and improved modified mNSS and modified Bederson scores of the rats (P < 0.05). In the cell experiment, pretreatment with TGF-β1 and TGF-β1+CYC both increased the viability of the primary meningeal fibroblasts after OGD/R. TGF-β1 significantly enhanced the migration ability and induced obvious transformation of the exposed cells (P < 0.05), but these effects were significantly attenuated by co-treatment with CYC (P < 0.05). The expressions of Shh, α-SMA and Fn in the TGF-β1 group were all significantly higher in TGF-β1-treated cells (P < 0.05) and were obviously lowered by co-treatment with CYC (P < 0.05).@*CONCLUSION@#Inhibition of Shh signaling may inhibit fibrous scar formation and functional recovery in rats after ischemic brain injury.

Transforming growth factor-β1 induces transformation of rat meningeal fibroblasts into myofibroblasts by upregulating Shh signaling / 南方医科大学学报

OBJECTIVE@#To investigate the effect of TGF-β1 on Shh signaling pathway during the transformation of meningeal fibroblasts into myofibroblasts.@*METHODS@#Primary meningeal fibroblasts were isolated from neonatal (24 h) SD rats and purified using type Ⅳ collagenase. The isolated cells were treated with 10 ng/mL TGF-β1 alone or in combination with 20 μmol/L SB-431542 (a TGF-β1 receptor inhibitor) for 72 h, and the changes in proliferation and migration abilities of the fibroblasts were assessed with CCK-8 assay and cell scratch test. The expression of fibronectin (Fn) was detected with immunofluorescence assay, and Western blotting was performed to examine the expressions of Fn, α-SMA and Shh protein in the cells; the expression of Shh mRNA was detected with real-time fluorescence quantitative PCR.@*RESULTS@#TGF-β1 treatment obviously enhanced the proliferation and migration of primary meningeal fibroblasts (P < 0.05), and promoted the transformation of meningeal fibroblasts into myofibroblasts and the secretion of Fn (P < 0.05). TGF-β1 treatment also upregulated the expression of Shh at both protein and mRNA levels (P < 0.05). Treatment with SB-431542 partially blocked the effect of TGF-β1 on the transformation of meningeal fibroblasts (P < 0.05).@*CONCLUSION@#TGF-β1 can induce the transformation of meningeal fibroblasts into myofibroblasts by up-regulating Shh expression in Sonic Hedgehog signaling pathway.

Effect of primary cilia-mediated shh signaling on neuronal-like cell differentiation of rat bone marrow stromal cells / 第二军医大学学报

To study the effect of primary cilia-mediated sonic hedgehog (Shh) signaling on differentiation of rat bone marrow stromal cells (MSCs) into neuron-like cells. Methods Rat MSCs were isolated and cultured. The study was divided into normal resveratrol-cultured group, resveratrol-induced group, SAG (Smoothened [Smo] agonist) group, and cyclopamine (Smo inhibitor) group. Cell morphology was observed under inverted microscope; the expressions of Ac-Tu, Ptc, Smo, and Glil were examined by immunofluorescence method. Western blotting analysis was used to detect the protein expressions of Smo and Gli, and RT-PCR was applied to detect mRNA expressions of Smo and Glil. Results No expression of primary cilia was found in the normally cultured MSCs. After pre-induction or 24 h starvation, MSCs expressed primary cilia, Ptc, Smo and Glil proteins, with Ptc protein in the primary cilia and Smo, Glil in the cytoplasm. In normal cultivation, resveratrol did not promote the translocation of Smo or induce differentiation of MSCs into neuronal-like cells. When MSCs expressed primary cilia, resveratrol and SAG led to translocation of Smo from the cytoplasm into primary cilia, accompanied by MSCs differentiation into neuronal-like cells and significantly increased expression of Smo and Glil mRNA and protein (P< 0. 05). When cyclopamine was added, Smo remained expressed in the cytoplasm, the expression of Smo and Glil mRNA and protein was significantly decreased (P < 0. 05), and MSCs differentiation into neuronal-like cells was inhibited. Conclusion MSCs express primary cilia and have Shh signaling. Primary cilia-mediated Shh signaling participates in MSCs differentiation into neuronal-like cells.