Reappraisal of the Roles of the Sonic Hedgehog Signaling Pathway in Hepatocellular Carcinoma

HCC remains one of the leading causes of cancer-related death globally. The main challenges in treatments of hepatocellular carcinoma (HCC) primarily arise from high rates of postoperative recurrence and the limited efficacy in treating advanced-stage patients. Various signaling pathways involved in HCC have been reported. Among them, the Sonic hedgehog (SHH) signaling pathway is crucial. The presence of SHH ligands is identified in approximately 60% of HCC tumor tissues, including tumor nests. PTCH-1 and GLI-1 are detected in more than half of HCC tissues, while GLI-2 is found in over 84% of HCC tissues. The SHH signaling pathway (including canonical and non-canonical) is involved in different aspects of HCC, including hepatocarcinogenesis, tumor growth, tumor invasiveness, progression, and migration. The SHH signaling pathway also contributes to recurrence, metastasis, modulation of the cancer microenvironment, and sustaining cancer stem cells. It also affects the resistance of HCC cells to chemotherapy, target therapy, and radiotherapy. Reappraisal of the roles of the SHH signaling pathway in HCC may trigger some novel therapies for HCC.

Novel HIF-1α Inhibitor AMSP-30m Mitigates the Pathogenic Cellular Behaviors of Hypoxia-Stimulated Fibroblast-Like Synoviocytes and Alleviates Collagen-Induced Arthritis in Rats via Inhibiting Sonic Hedgehog Pathway

Synovial hypoxia-inducible factor 1α (HIF-1α) is a prospective therapeutic target for rheumatoid arthritis (RA). AMSP-30 m, a novel HIF-1α inhibitor, was reported to have notable anti-arthritic effects in rats with adjuvant-induced arthritis. However, its roles in inhibiting the pathogenic behaviors of fibroblast-like synoviocytes (FLS) and the involved mechanisms remain unknown. Here, AMSP-30 m inhibited proliferation and induced apoptosis in hypoxia-induced RA FLS (MH7A cell line), as evidenced by decreased cell viability, reduced Ki67-positive cells, G0/G1 phase arrest, lowered C-myc and Cyclin D1 protein levels, emergence of apoptotic nuclear fragmentation, raised apoptosis rates, and activation of caspase 3. Furthermore, AMSP-30 m prevented hypoxia-induced increases in pro-inflammatory factor production, MMP-2 activity, migration index, migrated/invasive cells, and actin cytoskeletal rearrangement. In vivo, AMSP-30 m alleviated the severity of rat collagen-induced arthritis (CIA). Mechanically, AMSP-30 m reduced HIF-1α expression and blocked sonic hedgehog (Shh) pathway activation in hypoxia-induced MH7A cells and CIA rat synovium, as shown by declines in pathway-related proteins (Shh, Smo, and Gli-1). Particularly, the combination of Shh pathway inhibitor cyclopamine enhanced AMSP-30 m's inhibitory effects on the pathogenic behaviors of hypoxia-stimulated MH7A cells, whereas the combination of Shh pathway activator SAG canceled AMSP-30 m's therapeutic effects in vitro and in CIA rats, implying a close involvement of Shh pathway inhibition in its anti-arthritic effects. We likewise confirmed AMSP-30 m's anti-proliferative role in hypoxia-induced primary CIA FLS. Totally, AMSP-30 m suppressed hypoxia-induced proliferation, inflammation, migration, and invasion of MH7A cells and ameliorated the severity of rat CIA via inhibiting Shh signaling.

Anethole improves the developmental competence of porcine embryos by reducing oxidative stress via the sonic hedgehog signaling pathway

BACKGROUND

Anethole (AN) is an organic antioxidant compound with a benzene ring and is expected to have a positive impact on early embryogenesis in mammals. However, no study has examined the effect of AN on porcine embryonic development. Therefore, we investigated the effect of AN on the development of porcine embryos and the underlying mechanism.

RESULTS

We cultured porcine in vitro-fertilized embryos in medium with AN (0, 0.3, 0.5, and 1 mg/mL) for 6 d. AN at 0.5 mg/mL significantly increased the blastocyst formation rate, trophectoderm cell number, and cellular survival rate compared to the control. AN-supplemented embryos exhibited significantly lower reactive oxygen species levels and higher glutathione levels than the control. Moreover, AN significantly improved the quantity of mitochondria and mitochondrial membrane potential, and increased the lipid droplet, fatty acid, and ATP levels. Interestingly, the levels of proteins and genes related to the sonic hedgehog (SHH) signaling pathway were significantly increased by AN.

CONCLUSIONS

These results revealed that AN improved the developmental competence of porcine preimplantation embryos by activating SHH signaling against oxidative stress and could be used for large-scale production of high-quality porcine embryos.

Sonic Hedgehog Signaling Pathway: A Role in Pain Processing

Pain, as one of the most prevalent clinical symptoms, is a complex physiological and psychological activity. Long-term severe pain can become unbearable to the body. However, existing treatments do not provide satisfactory results. Therefore, new mechanisms and therapeutic targets need to be urgently explored for pain management. The Sonic hedgehog (Shh) signaling pathway is crucial in embryonic development, cell differentiation and proliferation, and nervous system regulation. Here, we review the recent studies on the Shh signaling pathway and its action in multiple pain-related diseases. The Shh signaling pathway is dysregulated under various pain conditions, such as pancreatic cancer pain, bone cancer pain, chronic post-thoracotomy pain, pain caused by degenerative lumbar disc disease, and toothache. Further studies on the Shh signaling pathway may provide new therapeutic options for pain patients.

[Retracted] Metformin exerts anticancer effects through the inhibition of the Sonic hedgehog signaling pathway in breast cancer

Following the publication of this paper, it was drawn to the Editor's attention by concerned readers that several of the cellular images shown in Figs. 6A and 8A, the scratch‑wound assay images shown in Fig. 5A, the western blotting data in Figs. 2C and 7A and the Matrigel invasion assays in Fig. 5C were strikingly similar to data appearing in different form in other articles by different authors. Owing to the fact that the contentious data in the above article had already been published elsewhere, or were already under consideration for publication, prior to its submission to International Journal of Molecular Medicine, the Editor has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a reply. The Editor apologizes to the readership for any inconvenience caused. [International Journal of Molecular Medicine 36: 204‑214, 2015; DOI: 10.3892/ijmm.2015.2217].

Sirt1 regulates microglial activation and inflammation following oxygen-glucose deprivation/reoxygenation injury by targeting the Shh/Gli-1 signaling pathway

BACKGROUND

Cerebral ischemic injury leads to over-activation of microglia, which release pro-inflammatory factors that deteriorate neurological function during the acute phase of stroke. Thus, inhibiting microglial over-activation is crucial for reducing ischemic injury. Sirtuin 1 (Sirt1) has been shown to play a critical role in stroke, neurodegenerative diseases and aging. However, the effect of Sirt1 on the regulation of microglial activation following cerebral ischemic injury, as well as the underlying mechanism, remain unknown. Therefore, the purpose of the present study is to mainly investigate the effect of Sirt1 on oxygen-glucose deprivation/reoxygenation (OGD/R)-treated N9 microglia following treatment with the Sirt1 agonists resveratrol and SRT1720 and the Sirt1 antagonist sirtinol.

METHODS

Cell viability, Apoptosis, activation and inflammatory responses of microglia, expressions and activity of Shh signaling pathway proteins were detected by Cell Counting Kit 8, Flow Cytometry, immunocytochemistry, ELISA, and Western blotting, respectively.

RESULTS

The results demonstrated that treatment with resveratrol or SRT1720 could inhibit the activation of microglia and inflammation during OGD/R. Moreover, these treatments also led to the translocation of the GLI family zinc finger-1 (Gli-1) protein from the cytoplasm to the nucleus and upregulated the expression of Sonic hedgehog (Shh), Patched homolog-1 (Ptc-1), smoothened frizzled class receptor and Gli-1. By contrast, the inhibition of Sirt1 using sirtinol had the opposite effect.

CONCLUSION

These findings suggested that Sirt1 may regulate microglial activation and inflammation by targeting the Shh/Gli-1 signaling pathway following OGD/R injury. Schematic representation of Sirt1 regulating the microglial activation and inflammation following oxygen-glucose deprivation/reoxygenation injury via mediation of Shh/Gli-1 signaling pathway.

Kaempferol inhibits renal fibrosis by suppression of the sonic hedgehog signaling pathway

BACKGROUND

Most chronic kidney diseases (CKDs) develop to end-stage renal disease (ESRD), which is characterized by fibrosis and permanent tissue and function loss. As a result, better and more effective remedies are essential. Kaempferol (KAE) is a common flavonoid extracted from plants. It can control the progression of kidney fibrosis and the epithelial-to-mesenchymal transition (EMT) of the renal tubular system.

PURPOSE

We aim to investigate the effect of KAE therapy on extracellular matrix deposition and stimulation of EMT in vitro and in vivo to elucidate the treatment mechanisms regulating these effects.

STUDY DESIGN

Chronic hypertension-induced kidney fibrosis was studied in spontaneously hypertensive rats with chronic kidney disease. Biochemical analysis, histological staining, and the expression level of relative proteins were used to assess the effect of KAE on renal function and fibrosis. The direct impact of KAE on proliferation and migration was evaluated using human renal tubular epithelial cells (HK-2) induced by transforming growth factor-β1 (TGF-β1), which can then induce EMT. The molecular mechanism of KAE was verified using co-IP assay and immunofluorescence.

RESULTS

KAE could reduce blood pressure and decrease the extracellular matrix (ECM) components (including collagen I and collagen Ш), TGF-β1, and α-SMA in the kidneys of hypertension-induced rats with chronic kidney disease. Moreover, in HK-2 cell treated with TGF-β1, KAE administration significantly suppressed proliferation, migration, and EMT via increasing the expression of E-cadherin, while reducing the N-cadherin and α-SMA. Sufu was exceedingly repressed in HK-2 cells treated with TGF-β1. KAE inhibited the activation of Shh and Gli through increasing the expression of Sufu, thereby blocking the nuclear translocation of Gli1 in vitro.

CONCLUSION

KAE ameliorated kidney fibrosis and EMT by inhibiting the sonic hedgehog signaling pathway, thereby to attenuate the pathological progression of hypertensive kidney fibrosis.

Paeoniflorin improves the in vitro maturation of benzo(a)pyrene treated porcine oocytes via effects on the sonic hedgehog pathway

Benzo(a)pyrene (BaP) is a toxic substance that people are often exposed to. It has serious harmful effects on the body, and has a destructive effect on oocytes and cumulus cells. Here, we found that paeoniflorin (Pae), a traditional Chinese medicine monomer with antioxidant effects, decreased BaP-induced meiotic failure by increasing the activity of the Sonic hedgehog (SHH) signaling pathway and reducing the level of reactive oxygen species (ROS). We found that the in vitro maturation (IVM) rate was significantly increased (P < 0.05) in the 0.1 μM Pae and BaP (co-treatment) group compared with BaP group due to reduced ROS levels and increased mitochondrial membrane potential (ΔΨ) and ATP content. The mRNA expression levels of oocyte maturation and cumulus cell expansion-related genes were also significantly higher in the co-treatment group. To demonstrate the quality of oocytes, the development capacity of parthenogenetically activated (PA) and in vitro fertilization (IVF) embryos from different treatment groups oocytes were determined.The blastocyst formation rate was significantly higher in PA and IVF embryos derived from oocytes in the co-treatment group than in those derived from oocytes in the BaP group. To further confirm that the SHH signaling pathway was involved in causing these effects of Pae, we treated oocytes with Pae and BaP in the presence or absence of cyclopamine (Cy), an inhibitor of this pathway. Cy abolished the effects of Pae in BaP treated porcine oocytes. In conclusion, Pae improves the IVM capacity of BaP-treated porcine oocytes by activating the SHH signaling pathway, inhibiting ROS production, and increasing ΔΨ.

[Electroacupuncture of "Shuigou"(GV26) improves neurological function by promoting angioge-nesis and Shh signaling in ischemic cerebral tissue of rats with cerebral infarction]

OBJECTIVE

To observe the effect of electroacupuncture (EA) of "Shuigou" (GV26) on the activities of sonic hedgehog(Shh) signaling molecules (Shh, Ptch, Smo，Gli and Gli2) in ischemic brain tissues in rats with cerebral ischemia (CI), so as to explore its mechanisms underlying improvement of CI.

METHODS

Male Wistar rats were randomly divided into blank control group(n=10), sham operation group (n=90), model group(n=90) and EA group (n=90). The CI model was established by occlusion of the right middle cerebral artery (MCAO). According to the postoperative time points of MCAO, the later three groups were further divided into 1, 3, 6, 9, 12 and 24 h, and 3, 7 and 12 d subgroups, with 10 rats in each subgroup. EA (15 Hz, 2 mA) was applied to GV26 for 20 min. The 1 h to 24 h subgroups were treated immediately after modeling, the 3-12 d subgroups treated one time a day. The neurological severity score (NSS, 0 to 18 points) was used to evaluate the rats' neurological function, and TTC staining was employed to assess the cerebral ischemic volume (percentage of cerebral infarct volume, CIV). Western blot was employed to detect the expression of Shh, Ptch, Smo, Gli1 and Gli2 proteins in the ischemic cerebral tissue.

RESULTS

Compared with the sham operation group, the NSS scores of the model group increased at all time points (P<0.01). The percentages of CIV of the model group from 3 h to 12 d were obviously higher than those of the sham operation group (P<0.01). The NSS scores at 3, 7 and 12 d and the percentages of CIV at 1, 3, 7 and 12 d after MCAO were significant lower in the EA group than in the model group (P<0.05). The protein expression levels of Shh from 12 h to 12 d (i.e. 12 h, 24 h, 3, 7 and 12 d), Ptch from 6 h to 12 d, Smo from 9 h to 12 d, Gli1 at 9 h, 12 h, and from 3 d to 12 d, Gli2 at 6, 9 and 12 h, and 3 d were significantly higher in the model group than in the sham operation group (P<0.05, P<0.01), while those of Shh at 3, 7 and 12 d, Ptch from 24 h to 7 d, Smo from 12 h to 7 d, Gli1 from 24 h to 7 d, Gli2 at 12 h, 3 and 7 d were significantly higher in the EA group than in the model group (P<0.05, P<0.01). No statistical significances were found between the sham operation and the blank control groups in all the indexes mentioned above (P>0.05).

CONCLUSION

EA of GV26 can improve neurological function and reduce infarct volume in MCAO rats, which may be related to its function in up-regulating the activities of Shh signaling pathway in the ischemic cerebral tissues.

Remyelination is enhanced by Astragalus polysaccharides through inducing the differentiation of oligodendrocytes from neural stem cells in cuprizone model of demyelination

Demyelination is the hallmark of multiple sclerosis (MS). Promoting remyelination is an important strategy to treat MS. Our previous study showed that Astragalus polysaccharides (APS), the main bioactive component of Astragalus membranaceus, could prevent demyelination in experimental autoimmune encephalomyelitis mice. To investigate the effects of APS on remyelination and the underlying mechanisms, in this study we set up a cuprizone-induced demyelination model in mice and treated them with APS. It was found that APS relieved the neurobehavioral dysfunctions caused by demyelination, and efficaciously facilitated remyelination in vivo. In order to determine whether the mechanism of enhancing remyelination was associated with the differentiation of neural stem cells (NSCs), biomarkers of NSCs, astrocytes, oligodendrocytes and neurons were measured in the corpus callosum tissues of mice through Real-time PCR, Western blot and immunohistochemistry assays. Data revealed that APS suppressed the stemness of NSCs, reduced the differentiation of NSCs into astrocytes, and promoted the differentiation into oligodendrocytes and neurons. This phenomenon was confirmed in the differentiation model of C17.2 NSCs cultured in vitro. Since Sonic hedgehog signaling pathway has been proven to be crucial to the differentiation of NSCs into oligodendrocytes, we examined expression levels of the key molecules in this pathway in vivo and in vitro, and eventually found APS activated this signaling pathway. Together, our results demonstrated that APS probably activated Sonic hedgehog signaling pathway first, then induced NSCs to differentiate into oligodendrocytes and promoted remyelination, which suggested that APS might be a potential candidate in treating MS.

Benzidine promotes the stemness of bladder cancer stem cells via activation of the Sonic hedgehog pathway

Substantial evidence suggests that cancer stem cells (CSCs) are the main cause of the initiation, progression and recurrence of tumors. Benzidine has been identified as a risk factor for bladder cancer. The aim of the present study was to investigate the effects of benzidine on bladder CSCs (BCSCs) and the possible mechanism underlying its action. The bladder cancer cell lines UM-UC-3 and EJ were maintained in serum-free medium and cells forming three-dimensional spheres were characterized as BCSCs. The sphere-forming cells were exposed to different concentrations of benzidine and vismodegib, and western blotting was performed to evaluate the expression of markers associated with CSCs and the Sonic hedgehog (SHH) signaling pathway. Flow cytometry was used to detect the distribution of cells in different phases of the cell cycle, and immunofluorescence staining was used to detect the protein expression of CD44. The results revealed that the levels of BCSC markers, namely CD133, CD44, aldehyde dehydrogenase 1-A1, Nanog and octamer-binding transcription factor-4, in the cell spheres were markedly elevated compared with those in cells cultured in serum-supplemented medium. Furthermore, benzidine increased the expression of BCSC markers and promoted the sphere-forming ability of the cells. In addition, it was observed that benzidine activated the SHH pathway, while inhibition of the Shh pathway using vismodegib diminished the promoting effects of benzidine on BCSCs. The findings of the present study indicate that benzidine promoted the stemness of BCSCs via activation of the SHH pathway, which may support further exploration of the molecular basis of the association between benzidine exposure and bladder oncogenesis.

Dl-3-n-butylphthalide promotes neurite outgrowth of primary cortical neurons by Sonic Hedgehog signaling via upregulating Gap43

Neurite outgrowth is the basis for wiring during the development of the nervous system. Dl-3-n-butylphthalide (NBP) has been recognized as a promising treatment to improve behavioral, neurological and cognitive outcomes in ischemic stroke. However, little is known about the effect and mechanism of NBP on the neurite outgrowth. In this study, we used different methods to investigate the potential effects of NBP on the neurite extension and plasticity of immature and mature primary cortical neurons and explored the underlying mechanisms. Our results demonstrated that in immature and mature cortical neurons, NBP promoted the neurite length and intersections, increased neuritic arborization, elevated numbers of neurite branch and terminal points and improved neurite complexity and plasticity of neuronal development processes. Besides, our data revealed that NBP promoted neurite extension and branching partly by activating Shh signaling pathway via increasing Gap43 expression both in immature and mature primary cortical neurons. The present study provided new insights into the contribution of NBP in neuronal plasticity and unveiled a novel pathway to induce Gap43 expression in primary cortical neurons.

β2 -adrenergic receptor signaling drives prostate cancer progression by targeting the Sonic hedgehog-Gli1 signaling activation

BACKGROUND

Considerable evidence suggests that the sympathetic nervous system, mainly via adrenergic signaling, contributes to prostate cancer (PCa) progression. However, the underlying molecular mechanisms remain unknown.

METHODS

The expression level of β₂ -adrenergic receptor (β₂ -AR) in tissue microarray was evaluated by immunohistochemistry. The effects of isoproterenol (ISO) or Sonic Hedgehog (Shh) signaling inhibitor on tumor growth were analyzed in proliferation and colony formation assays. The apoptosis of cells was analyzed by flow cytometry. Small hairpin RNA-based knockdown of β₂ -AR or Gli1 was validated by Western blot analysis and real-time PCR. Effects of β₂ -AR on prostate carcinogenesis in vivo were observed in a mouse xenograft model. The expression levels of the indicated proteins in xenograft tissues were evaluated by immunohistochemistry. Expression levels of Shh signaling components and downstream proteins were assessed by immunoblotting.

RESULTS

We determined that β₂ -AR was expressed at significantly higher levels in carcinoma than in normal prostate tissues. β₂ -AR signaling also played an essential role in sustaining PCa cell proliferation in vivo and in vitro. We also found that inhibition of Shh signaling or knockdown of Gli1 expression significantly restrained ISO-induced cell proliferation in vitro. ISO alleviated the apoptosis induced by suppressing or knocking down of Gli1. The β₂ -AR agonist ISO upregulated the transcription and protein expression of target genes of Shh signaling, including c-Myc, Cyclin D1, and VEGFA. Conversely, knocking down β₂ -AR markedly suppressed the expression of Shh components in vivo and in vitro. In Gli1 knockdown cells, ISO failed to increase the expression of target genes of Shh signaling.

CONCLUSIONS

In this study, we uncovered an important role of β₂ -AR signaling in regulating the Shh pathway activity in PCa tumorigenesis and provide further insight into the mechanism of the involvement of the Hh signaling pathway. Furthermore, given the efficacy of β₂ -adrenergic modulation on PCa, our study might also add evidence for potential therapeutic options of β-blockers for PCa.

Sonic hedgehog signaling pathway in Myelodysplastic Syndrome: Abnormal activation and jervine intervention

OBJECTIVE

This study aims to investigate the roles of Sonic hedgehog (Shh) signaling pathway in the occurrence and progression of Myelodysplastic Syndrome (MDS) and further evaluate using jervine as therapeutic strategy for MDS by inhibiting Shh pathway.

METHODS

CD34+ cells from the bone marrow of 53 MDS patients were counted by flow cytometry and isolated by magnetic bead sorting. Shh, Smo, Ptch-1 and Gli-1 (involved in Shh pathway) in CD34+ cells were examined by RT-qPCR. Besides, the relationship between Shh pathway-related genes and the clinical features or prognosis of MDS were analyzed. Further, the effects of jervine on MUTZ-1 cells regarding their proliferation, apoptosis and cell cycle as well as Shh pathway-related gene and protein expression were analyzed.

RESULTS

Gene expression level of Shh, Gli-1 and Smo was significantly increased in MDS patients. Herein, Smo and Gli-1 were correlated with chromosome karyotype classification and IPSS. MDS patients with high expression of Smo or Gli-1 had a poor prognosis. Jervine inhibited gene and protein expression of Shh, Smo, Ptch-1 and Gli-1. Besides, jervine suppressed the proliferation and promoted the apoptosis of MUTZ-1 cells, as well as inhibited the transition of cells from G1 to S phase.

CONCLUSION

Shh signaling pathway of MDS patients is abnormally activated and participated in the occurrence and progression of MDS. Jervine intervention is a potential therapeutic strategy for MDS.

Regulation of miR-375 and Sonic hedgehog on vascular endothelial growth factor in preeclampsia rats and its effect on trophoblast cells

PURPOSE

To study the mechanism of vascular endothelial growth factor (VEGF) regulated by miR-375 and Sonic hedgehog (SHH) signaling pathways on the characteristics of trophoblast cells (TCs) in preeclampsia (PE) rats.

METHODS

Female (100) Wistar rats in rut were mated with males (50) at a ratio of 2:1, and 60 pregnant rats were assigned to a normal group (Nor, n=10) and a model group (Mod, n=50) in a random manner. Rat TCs of placental villus were isolated and were divided into 8 groups. The related indicators in each group were detected, respectively.

RESULTS

In contrast to the NC group, miR-375 expression greatly elevated in the miR-375 mimic group (mimic group); in the mimic and cyclopamine groups, VEGF, proliferating cell nuclear antigen（PCNA, N- cadherin and Bcl-2 expression, cell proliferation, S phase cells, and migration and invasion ability were significantly decreased and E-cadherin and Bax expression, G1 phase cells and apoptosis rate were increased significantly, but in Over expressing-VEGF（ov-VEGF） group, the above indicators presented contrary results (all P< 0.05). In contrast to the mimic group, the expression of SHH, VEGF, PCNA, N- cadherin and Bcl-2, cell proliferation, S phase cells and the invasion and migration activity in the miR-375 mimic + oe-VEGF group were evidently increased.

CONCLUSIONS

Over-expressing miR-375 can inhibit the expression of VEGF, thus slow down the invasion and proliferation of TCS in PE rats, which is realized by regulating SHH signal pathway.

Tissue Plasminogen Activator Causes Brain Microvascular Endothelial Cell Injury After Oxygen Glucose Deprivation by Inhibiting Sonic Hedgehog Signaling

The thrombolytic activity of tissue plasminogen activator (tPA) has undisputed benefits. However, the documented neurotoxicity of tPA raises important issues. Currently, common treatments for stroke might not be optimum if exogenous tPA can pass through the blood–brain barrier and enter the brain, thus adding to the deleterious effects of tPA within the cerebral parenchyma. Here, we determined whether tPA could damage brain microvascular endothelial cells (BMECs) during cerebral ischemia. We showed that treatment of BMECs with tPA decreased trans-endothelial electrical resistance and cell proliferation, and blocked the cell cycle at the G0–G1 phase. In addition, the Sonic hedgehog (Shh) signaling pathway was involved in tPA-induced BMECs dysfunction. However, tPA-enhanced oxygen glucose deprivation-induced BMECs dysfunction was eliminated by Shh administration and the effects could be reversed by Shh inhibitors. Taken together, these results demonstrate that tPA administration might result in damage to the endothelial barrier owing to blocked Shh signaling pathway.

Itraconazole Attenuates Peritoneal Fibrosis Through Its Effect on the Sonic Hedgehog Signaling Pathway in Mice

BACKGROUND

Peritoneal fibrosis is a devastating complication of peritoneal dialysis. However, its precise mechanism is unclear, and specific treatments have not yet been established. Recent evidence suggests that the sonic hedgehog (SHH) signaling pathway is involved in tissue fibrogenesis. Drugs that inhibit this pathway are emerging in the field of anti-fibrosis therapy. Itraconazole, an anti-fungal agent, was also recently recognized as an inhibitor of the SHH signaling pathway. In this study, we used a mouse model to investigate whether the SHH signaling pathway is involved in the development of peritoneal fibrosis and the effects of itraconazole on peritoneal fibrosis.

METHODS

Peritoneal fibrosis was induced by intraperitoneal (IP) injection of 0.1% chlorhexidine gluconate (CG) solution every other day for 4 weeks, with or without itraconazole treatment (20 mg/kg, IP injection on a daily basis). Male C57BL/6 mice were divided into 4 groups: saline group, saline plus itraconazole group, CG group, and CG plus itraconazole group. Isotonic saline was administered intraperitoneally to the control group. The peritoneal tissues were evaluated for histological changes, expression of fibrosis markers, and the main components of the SHH signaling pathway.

RESULTS

Peritoneal thickening was evident in the CG group and was significantly decreased by itraconazole administration (80.4 ± 7.7 vs. 28.2 ± 3.8 µm, p < 0.001). The expression of the following SHH signaling pathway components was upregulated in the CG group and suppressed by itraconazole treatment: SHH, patched, smoothened, and glioma-associated oncogene transcription factor 1. The IP injection of CG solution increased the expression of fibrosis markers such as α-smooth muscle actin and transforming growth factor-β1 in the peritoneal tissues. Itraconazole treatment significantly decreased the expression of these markers.

CONCLUSION

Our study provides the first evidence that the SHH signaling pathway may be implicated in peritoneal fibrosis. It also demonstrates that itraconazole treatment has protective effects on peritoneal fibrosis through the regulation of the SHH signaling pathway. These findings suggest that blockage of the SHH signaling pathway is a potential therapeutic strategy for peritoneal fibrosis.

Distinct Involvement of the Sonic Hedgehog Signaling Pathway in Gastric Adenocarcinoma of Fundic Gland Type and Conventional Gastric Adenocarcinoma

BACKGROUND/AIMS

Gastric adenocarcinoma of fundic gland type (GAFG), which is a rare variant of gastric cancer, is reportedly associated with both Wnt/β-catenin signaling activation and guanine nucleotide binding protein, alpha stimulating complex (GNAS) mutations. This study aimed to elucidate potential roles of the Sonic hedgehog (Shh) signaling pathway in GAFG.

METHODS

We performed immunostaining for β-catenin and Shh signal-associated proteins, including Patched (Ptch), Smoothened (Smo), and Glioma-associated oncogene-1 (Gli1), and the direct sequencing of GNAS/BRAF/KRAS in 27 GAFGs, and compared them with 30 conventional gastric adenocarcinomas (CGAs).

RESULTS

GAFGs exhibited significantly lower immunoreactivity scores for Ptch, Smo, and Gli1 than CGAs. Moreover, while the Ptch score was significantly lower in the GAFG tumor areas than in the non-neoplastic areas adjacent to GAFG, the score was significantly higher in the CGA tumor areas than in the non-neoplastic areas. Similar trends were observed in the scores for Smo and Gli1. β-Catenin expression and GNAS mutations were found in 22 (81%) and 8 (30%) of the 27 GAFGs respectively. Gli1 expression was significantly associated with mutations in GNAS.

CONCLUSION

GAFG and CGA exhibited distinct Ptch, Smo, and Gli1 expression patterns. Downregulation of the Shh signaling pathway, as well as activation of the Wnt/β-catenin signaling pathway, may therefore be associated with tumorigenesis in GAFG.

PM2.5 promotes human bronchial smooth muscle cell migration via the sonic hedgehog signaling pathway

Background

The contribution of airway remodeling in chronic obstructive pulmonary disease (COPD) has been well documented, with airway smooth muscle cell proliferation and migration playing a role in the remodeling process. Here, we aimed to verify the effects of fine particulate matter (PM2.5) on human bronchial smooth muscle cell (HBSMC) migration and to explore the underlying signaling pathways.

Methods

HBSMC apoptosis, proliferation and migration were measured using flow cytometry, cell counting and transwell migration assays, respectively. The role of the hedgehog pathway in cell migration was assessed by western blotting to measure the expression of Sonic hedgehog (Shh), Gli1 and Snail. Furthermore, siRNA was used to knock down Gli1 or Snail expression.

Results

PM2.5 induced HBSMC apoptosis in a dose-dependent manner, although certain concentrations of PM2.5 did not induce HBSMC proliferation or apoptosis. Interestingly, cell migration was stimulated by PM2.5 doses far below those that induced apoptosis. Additional experiments revealed that these PM2.5 doses enhanced the expression of Shh, Gli1 and Snail in HBSMCs. Furthermore, PM2.5-induced cell migration and protein expression were enhanced by recombinant Shh and attenuated by cyclopamine. Similar results were obtained by knocking down Gli1 or Snail.

Conclusions

These findings suggest that PM2.5, which may exert its effects through the Shh signaling pathway, is necessary for the migration of HBSMCs. These data define a novel role for PM2.5 in airway remodeling in COPD.

Electronic supplementary material

The online version of this article (10.1186/s12931-017-0702-y) contains supplementary material, which is available to authorized users.

HIF-1 maintains a functional relationship between pancreatic cancer cells and stromal fibroblasts by upregulating expression and secretion of Sonic hedgehog

Hypoxic and stroma-rich microenvironments, characteristic features of pancreatic cancers, are strongly associated with a poor prognosis. However, whether and how hypoxia increases stromal compartments remain largely unknown. Here, we investigated the potential importance of a master regulator of the cellular adaptive response to hypoxia, hypoxia-inducible factor-1 (HIF-1), in the formation of stroma-rich microenvironments of pancreatic tumors. We found that pancreatic cancer cells secreted more Sonic hedgehog protein (SHH) under hypoxia by upregulating its expression and efficiency of secretion in a HIF-1-dependent manner. Recombinant SHH, which was confirmed to activate the hedgehog signaling pathway, accelerated the growth of fibroblasts in a dose-dependent manner. The SHH protein secreted from pancreatic cancer cells under hypoxic conditions promoted the growth of fibroblasts by stimulating their Sonic hedgehog signaling pathway. These results suggest that the increased secretion of SHH by HIF-1 is potentially responsible for the formation of detrimental and stroma-rich microenvironments in pancreatic cancers, therefore providing a rational basis to target it in cancer therapy.

Stimulation of IL-1β and IL-6 through NF-κB and sonic hedgehog-dependent pathways in mouse astrocytes by excretory/secretory products of fifth-stage larval Angiostrongylus cantonensis

BACKGROUND

Angiostrongylus cantonensis is an important causative agent of eosinophilic meningitis and eosinophilic meningoencephalitis in humans. Previous studies have shown that the Sonic hedgehog (Shh) signaling pathway may reduce cell apoptosis by inhibiting oxidative stress in A. cantonensis infection. In this study, we investigated the relationship between cytokine secretion and Shh pathway activation after treatment with excretory/secretory products (ESP) of fifth-stage larval A. cantonensis (L5).

RESULTS

The results showed that IL-1β and IL-6 levels in mouse astrocytes were increased. Moreover, ESP stimulated the protein expression of Shh pathway molecules, including Shh, Ptch, Smo and Gli-1, and induced IL-1β and IL-6 secretion. The transcription factor nuclear factor-κB (NF-κB) plays an important role in inflammation, and it regulates the expression of proinflammatory genes, including cytokines and chemokines, such as IL-1β and TNF-α. After ESP treatment, NF-κB induced IL-1β and IL-6 secretion in astrocytes by activating the Shh signaling pathway.

CONCLUSIONS

Overall, the data presented in this study showed that ESP of fifth-stage larval A. cantonensis stimulates astrocyte activation and cytokine generation through NF-κB and the Shh signaling pathway.

Salvianolic Acids for Injection (SAFI) promotes functional recovery and neurogenesis via sonic hedgehog pathway after stroke in mice

There is a pressing need of developing approaches for delayed post-stroke therapy for patients who fail to receive thrombolysis within the narrow time window. Neuroprotection of Salvianolic Acids for Injection (SAFI) for cerebral ischemia-reperfusion injury in acute phase has been well documented. The current study was to determine the influence of SAFI at the subacute phase after stroke in mice, and to elucidate the underlying mechanisms. Adult male C57BL/6 mice were subjected to permanent occlusion of the distal middle cerebral artery (dMCAO), followed by daily intraperitoneal injection of SAFI 24 h after stroke for 14 days. Motor behavior was measured by neurological function evaluations weekly, and proliferation, migration, survival and differentiation of neural progenitor cells (NPCs) were examined with immunohistochemistry. Sonic hedgehog (Shh) inhibitor cyclopamine (CYC) was injected to determine the involvement of Shh pathway in the therapeutic effects of SAFI. The results showed that SAFI led to dramatic brain functional improvement, elevated NPCs proliferation, and prompted long-term survival of newborn neurons in the subventricular zone (SVZ). Up-regulation of Shh, Ptch and nuclear translocation of Gli1 were observed in the peri-infarct region, accompanied with robust production of Brain derived neurotrophic factor (BDNF) and Nerve growth factor (NGF). Simultaneous administration with CYC strikingly attenuated the beneficial outcomes of SAFI as well as abolished SAFI induced BDNF and NGF production. Collectively, our study demonstrated SAFI significantly promoted long-term functional recovery and neurogenesis, which might be dependent on Shh signaling mediated BDNF and NGF production. Therefore, SAFI might serve as a potential clinically translatable therapy during recovery stage after stroke.

Protein and mRNA expression of Shh, Smo and Gli1 and inhibition by cyclopamine in hepatocytes of rats with chronic fluorosis

In order to investigate the Sonic hedgehog (Shh) signaling pathway and the effect of cyclopamine in rat hepatocytes with chronic fluorosis, 48 Wistar rats were randomly divided into 4 groups. The control group was provided with tap water in which the fluorine concentration was <1mg/L, while the remaining three groups were provided with water containing sodium fluoride (NaF) at a concentration of 50mg/L. After 6 months, the blocking and blocking control groups were injected intraperitoneally once every 2 days for 6 days with 10mg/kg cyclopamine or dimethyl sulfoxide, respectively. The urinary and skeletal fluoride contents were determined by the ion selective electrode method. Levels of aspartate transaminase (AST), alanine transaminase (ALT), total protein (TP) and albumin (Alb) in the serum were determined by using autobiochemical machine. Histological changes in liver tissue were evaluated with Hematoxylin & Eeosin (H&E) staining using light microscopy. The protein and mRNA expression of Shh, Smo and Gli1 in hepatocytes of experimental animals was determined by immunohistochemistry (IHC), Western blotting (Wb) and Real-time quantitative PCR (RT-qPCR). Fluoride content of the urine and bone was increased in the fluorosis and blocking groups compared to those in the control group (P<0.05), while fluoride content in the blocking group was decreased compared to the fluorosis and blocking control groups (P<0.05). The expression of Shh, Smo and Gli1 at the mRNA and protein levels was significantly increased in hepatocytes from the fluorosis and blocking control groups compared with the control group, and expression in the blocking group was lower than that of the fluorosis and blocking control groups. The difference between any two groups was considered to be statistically significant (P<0.05). Taken together, our study indicates that the expression of Shh, Smo and Gli1 at the protein and mRNA level in hepatocytes of rats with chronic fluorosis can be increased by fluoride and may be inhibited by cyclopamine and that the Shh signaling pathway plays an important role in the liver pathogenesis caused by fluorosis.