Activation Of Shh Signaling Pathway Research Articles

AMPK attenuates SHH subgroup medulloblastoma growth and metastasis by inhibiting NF-κB activation

BackgroundMedulloblastoma (MB) is one of the most common malignant pediatric brain tumors. Metastasis and relapse are the leading causes of death in MB patients. The initiation of the SHH subgroup of MB (SHH-MB) is due to the aberrant activation of Sonic Hedgehog (Shh) signaling. However, the mechanisms for its metastasis are still unknown.ResultsAMP-dependent protein kinase (AMPK) restrains the activation of Shh signaling pathway, thereby impeding the proliferation of SHH-MB cells. More importantly, AMPK also hinders the growth and metastasis of SHH-MB cells by regulating NF-κB signaling pathway. Furthermore, Vismodegib and TPCA-1, which block the Shh and NF-κB pathways, respectively, synergistically restrained the growth, migration, and invasion of SHH-MB cells.ConclusionsThis work demonstrates that AMPK functions through two signaling pathways, SHH-GLI1 and NF-κB. AMPK-NF-κB axis is a potential target for molecular therapy of SHH-MB, and the combinational blockade of NF-κB and Shh pathways confers synergy for SHH-MB therapy.

ACTIVATION OF SHH SIGNALING PATHWAY AND RELATIONSHIP WITH MYOFIBROBLASTS

Objective: This study investigated components of the HH pathway (SHH, GLI1, and cyclin D1) in central giant cell granulomas (CGCG). The relationship between these proteins and myofibroblasts was also studied. Material and Methods: Twelve cases of non-aggressive CGCG and 11 cases of aggressive CGCG were studied using immunohistochemistry for SHH, GLI1, Cyclin D1, and SMA. Results: Associations between all proteins in non-aggressive and aggressive CGCG were not significant (P > .05). All cases of CGCG showed significantly higher expression of SMA compared to the other proteins (P < .01). A positive correlation (P = .04) was only observed between SHH and GLI1 for all cases of CGCG. Furthermore, a positive correlation between SHH and GLI1 in non-aggressive CGCG (P = .04) and between GLI1 and cyclin D1 in aggressive CGCG (P = .03) were observed. There was also a negative correlation between the expression of SHH and SMA in non-aggressive CGCG (P = .031). Conclusions: This study provided insights into the activation of the SHH pathway in CGCG. In addition, the activation of this pathway may play some role in the differentiation of stromal myofibroblasts, but this differentiation process would occur at the expense of maturation of these lesions. Objective: This study investigated components of the HH pathway (SHH, GLI1, and cyclin D1) in central giant cell granulomas (CGCG). The relationship between these proteins and myofibroblasts was also studied. Material and Methods: Twelve cases of non-aggressive CGCG and 11 cases of aggressive CGCG were studied using immunohistochemistry for SHH, GLI1, Cyclin D1, and SMA. Results: Associations between all proteins in non-aggressive and aggressive CGCG were not significant (P > .05). All cases of CGCG showed significantly higher expression of SMA compared to the other proteins (P < .01). A positive correlation (P = .04) was only observed between SHH and GLI1 for all cases of CGCG. Furthermore, a positive correlation between SHH and GLI1 in non-aggressive CGCG (P = .04) and between GLI1 and cyclin D1 in aggressive CGCG (P = .03) were observed. There was also a negative correlation between the expression of SHH and SMA in non-aggressive CGCG (P = .031). Conclusions: This study provided insights into the activation of the SHH pathway in CGCG. In addition, the activation of this pathway may play some role in the differentiation of stromal myofibroblasts, but this differentiation process would occur at the expense of maturation of these lesions.

Inhibition of MicroRNA-195 Alleviates Neuropathic Pain by Targeting Patched1 and Inhibiting SHH Signaling Pathway Activation.

Trigeminal neuralgia (TN) is a type of chronic neuropathic pain that is caused by peripheral nerve lesions that result from various conditions, including the compression of vessels, tumors and viral infections. MicroRNAs (miRs) are increasingly recognized as potential regulators of neuropathic pain. Previous evidence has demonstrated that miR-195 is involved in neuropathic pain, but the mechanism remains unclear. To investigate the pathophysiological role of miR-195 and Shh signaling in TN, persistent facial pain was induced by infraorbital nerve chronic constriction injury (CCI-IoN), and facial pain responses were evaluated by Von Frey hairs. qPCR and Western blotting were used to determine the relative expression of miR-195 and Patched1, the major receptor of the Sonic Hedgehog (Shh) signaling pathway, in the caudal brain stem at distinct time points after CCI-IoN. Here, we found that the expression of miR-195 was increased in a rat model of CCI-IoN. In contrast, the expression of Patched1 decreased significantly. Luciferase assays confirmed the binding of miR-195 to Patched1. In addition, the overexpression of miR-195 by an intracerebroventricular (i.c.v) administration of LV-miR-195 aggravated facial pain development, and this was reversed by upregulating the expression of Patched1. These results suggest that miR-195 is involved in the development of TN by targeting Patched1 in the Shh signaling pathway, thus regulating extracellular glutamate.

Polydatin ameliorates dextran sulfate sodium-induced colitis by decreasing oxidative stress and apoptosis partially via Sonic hedgehog signaling pathway

BackgroundInflammation, oxidative stress and epithelial barrier dysfunction have been implicated in inflammatory bowel disease (IBD) pathology. The targeted inhibition of these features may represent a promising therapeutic strategy for IBD. Polydatin is an effective natural antioxidant that possesses strong antioxidant and anti-apoptotic properties. Thus, we studied the protective effects of polydatin treatments on a mouse model of experimental colitis. MethodsAcute colitis was experimentally induced by adding 3% dextran sulfate sodium (DSS) to the drinking water provided to mice for 7 days and by administering different doses of polydatin (15, 30, or 45 mg/kg) during the same period. Mice were also treated with the Sonic hedgehog (Shh) pathway inhibitor cyclopamine to estimate the efficacy of polydatin and Shh inhibitors on colitis. The disease activity index (DAI), colon length, histology, levels of oxidative and apoptotic mediators and levels of Shh pathway components were evaluated. ResultsThe polydatin treatment significantly attenuated the DAI, colon shortening and histological damage. In addition, polydatin administration effectively decreased malondialdehyde (MDA) levels and increased the activities of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). Polydatin also inhibited apoptosis in mice with colitis by downregulating the expression of the pro-apoptotic proteins Bax, caspase 3 and cleaved caspase 3 and increasing the expression of the anti-apoptotic protein Bcl-2. Furthermore, polydatin modulated Shh signaling pathway activation. After polydatin treatment, the main components of the Shh pathway, including Shh, Patched (Ptc), Smoothened (Smo), and glioblastoma-1 (Gli1), were upregulated at the mRNA and protein levels. Blockade of the Shh pathway using cyclopamine abolished the effects of polydatin on mice with colitis. ConclusionBased on these observations, polydatin may suppress experimental colitis at least partially by regulating the Shh signaling pathway.

Liver kinase B1 suppresses growth of lung cancer cells through sonic hedgehog signaling pathway.

Lung cancer is one of life-threatening cancers in the worldwide. Liver kinase B1 (LKB1) has been reported to be closely related to cancers; however, the underlying mechanism of LKB1 in lung cancer remains unclear. In our study, a LKB1 specific shRNA was employed to down-regulate LKB1 levels and a LKB1 over-expression plasmid was constructed to up-regulate LKB1 levels. Thereafter, growth of lung cancer cells was assessed by MTT assay and flow cytometry. Effects of LKB1 on the activation of sonic hedgehog (Shh) signaling pathway were detected by Western blot. Effects of LKB1 on lung cancer growth and Shh signaling pathway activation were also assessed in vivo. Our results showed that LKB1 inhibited proliferation of lung cancer cells and induced their apoptosis. Moreover, LKB1 inhibited Shh signaling pathway activation. Our in vivo study also showed that LKB1 inhibited lung cancer growth in vivo and modulated Shh signaling pathway. Treatment with cyclopamine, a Shh signaling pathway inhibitor, reversed the effects of LKB1 silencing and enhanced the effects of LKB1 over-expression. Results of our study demonstrate that LKB1 inhibits lung cancer growth in vitro and in vivo through Shh signaling pathway.

Genipin-cross-linked type II collagen scaffold promotes the differentiation of adipose-derived stem cells into nucleus pulposus-like cells.

Adipose-derived stem cells (ADSCs)-based tissue engineering was a promising method to treat intervertebral disc degeneration. Type II collagen is a native component in the nucleus pulposus (NP), and has the ability to promote ADSCs to differentiate into NP-like cells. In this article, we aimed to establish a genipin-cross-linked three-dimensional (3D) type II collagen scaffold, and determine the biological effects of the scaffold on ADSCs differentiating into a NP-like phenotype. Different concentrations of genipin were used to cross-link the 3D type II collagen scaffold. Microstructure, surface topography, mechanical strength, porosity, swelling property, and biological stability of the scaffolds were detected to evaluate the scaffold properties. Cell proliferation, gene and protein expression were measured to access the biological effects of the scaffolds on ADSCs, and the related molecular mechanism was investigated. Cross-linking by genipin increased the stability of the type II collagen scaffolds, but deformed the configuration of scaffolds and changed the intrinsic properties of type II collagen. scaffold cross-linked with 0.1% genipin improved the biostability on the basis of maintaining the configuration of scaffold. In addition, the 0.1% genipin-cross-linked scaffold promoted ADSCs proliferation and differentiation into NP-like cells, along with the increasing gene and protein expressions of Sonic Hedgehog (Shh). All these results suggested that 0.1% genipin was the optimal concentration to establish a bio-stable 3D type II collagen scaffold, which inducing ADSC proliferation and differentiation toward a NP-like phenotype through the activation of Shh signaling pathway. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1258-1268, 2018.

Sinomenine reduces growth and metastasis of breast cancer cells and improves the survival of tumor-bearing mice through suppressing the SHh pathway

In this study, the suppressive effect of sinomenine on the activation of SHh and the progression of breast cancer metastasis in vitro and in vivo was investigated. MDA-MB-231 breast cancer cells were treated with sinomenine and/or cyclopamine a proven SHh inhibitor. Sinomenine and cyclopamine both suppressed cell proliferation and migration, but sinomenine had a stronger suppressive effect in MDA-MB-231. In addition, sinomenine could suppress the activation of NF-κB and SHh signaling pathways, but cyclopamine could not suppress the activation of NF-κB. Subsequently, a mouse breast cancer-lung metastasis model was established. Our data on tissue examination and gene detection showed that SHh signaling was markedly activated in the metastatic model mice. The progression of lung metastasis was suppressed when mice were fed sinomenine and/or cyclopamine, while sinomenine had a stronger suppressive effect than cyclopamine in the model mice. In conclusion, sinomenine has a better effect than cyclopamine on the inhibition of breast cancer metastasis to lung in vivo and vitro, and inhibits NF-κB activation and NF-κB-mediated activation of SHh signaling pathway.

Editorial: Adrenal Cortex: From Physiology to Disease

Editorial: Adrenal Cortex: From Physiology to Disease

Pancreatic stellate cells contribute pancreatic cancer pain via activation of sHH signaling pathway.

Abdominal pain is a critical clinical symptom in pancreatic cancer (PC) that affects the quality of life for PC patients. However, the pathogenesis of PC pain is largely unknown. In this study, we show that PC pain is initiated by the sonic hedgehog (sHH) signaling pathway in pancreatic stellate cells (PSCs), which is activated by sHH secreted from PC cells, and then, neurotrophic factors derived from PSCs mediate the pain. The different culture systems were established in vitro, and the expression of sHH pathway molecules, neurotrophic factors, TRPV1, and pain factors were examined. Capsaicin-evoked TRPV1 currents in dorsal root ganglion (DRG) neurons were examined by the patch-clamp technique. Pain-related behavior was observed in an orthotopic tumor model. sHH and PSCs increased the expression and secretion of TRPV1, SP, and CGRP by inducing NGF and BDNF in a co-culture system, also increasing TRPV1 current. But, suppressing sHH pathway or NGF reduced the expression of TRPV1, SP, and CGRP. In vivo, PSCs and PC cells that expressed high levels of sHH could enhance pain behavior. Furthermore, the blockade of NGF or TRPV1 significantly attenuated the pain response to mechanical stimulation compared with the control. Our results demonstrate that sHH signaling pathway is involved in PC pain, and PSCs play an essential role in the process greatly by inducing NGF.

DISCOVERY AND EVALUATION OF POTENTIAL SONIC HEDGEHOG SIGNALING PATHWAY INHIBITORS USING PHARMACOPHORE MODELING AND MOLECULAR DYNAMICS SIMULATIONS

Sonic hedgehog (Shh) plays an important role in the activation of Shh signaling pathway that regulates preservation and rebirth of adult tissues. An abnormal activation of this pathway has been identified in hyperplasia and various tumorigenesis. Hence the inhibition of this pathway using a Shh inhibitor might be an efficient way to treat a wide range of malignancies. This study was done in order to develop a lead chemical candidate that has an inhibitory function in the Shh signaling pathway. We have generated common feature pharmacophore models using three-dimensional (3D) structural information of robotnikinin, an inhibitor of the Shh signaling pathway, and its analogs. These models have been validated with fit values of robotnikinin and its analogs, and the best model was used as a 3D structural query to screen chemical databases. The hit compounds resulted from the screening docked into a proposed binding site of the Shh named pseudo-active site. Molecular dynamics (MD) simulations were performed to investigate detailed binding modes and molecular interactions between the hit compounds and functional residues of the pseudo-active site. The results of the MD simulation analyses revealed that the hit compounds can bind the pseudo-active site with high affinity than robotnikinin. As a result of this study, a candidate inhibitor (GK 03795) was selected as a potential lead to be employed in future Shh inhibitor design.