Cyclopamine Group Research Articles

Expression and Functional Analysis of the Smo Protein in Apis mellifera.

Smoothened (Smo) is a critical component regulating the Hedgehog signaling pathway. However, whether Smo is associated with the modulation of olfactory recognition capabilities of bees remains unclear. In this study, we amplified Smo from Apis mellifera. The coding sequence of Smo was 2952 bp long, encoded 983 amino acids. Smo was most highly expressed in the antennae. Cyclopamine (200 μg/mL) significantly reduced but purmorphamine (800 μg/mL) significantly increased Smo expression (p < 0.05). OR152 and OR2 expression in the cyclopamine group significantly decreased, whereas OR152 expression in the purmorphamine group significantly increased (p < 0.05). A significant decrease in the relative values of electroantennography was observed in the cyclopamine group exposed to neral. Behavioral tests indicated a significant decrease in the attractive rates of neral, VUAA1, linalool, and methyl heptenone in the cyclopamine group. Conversely, the selection rates of linalool and methyl heptenone in the purmorphamine group significantly increased. Our findings indicate that Smo may play a role in modulating olfactory receptors in bees.

Effects of isoflurane postconditioning on angiogenesis during cerebral ischemia-reperfusion in rats and the role of Shh signaling pathway

Objective To evaluate the effects of isoflurane postconditioning on angiogenesis during cerebral ischemia-reperfusion (I/R) in rats and the role of Shh signaling pathway. Methods Thirty-two clean-grade healthy male Sprague-Dawley rats, aged 6-8 weeks, weighing 220-280 g, were divided into 4 groups (n=8 each) by a random number table method: sham operation group (Sham group), I/R group, isoflurane postconditioning group (ISO group), and isoflurane postconditioning plus Shh signaling pathway specific inhibitor cyclopamine group (ISO + CYC group). Cerebral ischemia was produced by inserting a 3-0 nylon thread with a rounded tip into the internal jugular vein. The nylon thread was threaded cranially until resistance was met. Occlusion was maintained for 1.5 h followed by 24 h reperfusion. Neurological deficit was scored at 24 h of reperfusion. Rats were then sacrificed, and brains were removed for determination of cerebral infarct volume (by TTC) and expression of glioma-associated oncogene homolog 1 (Gli1), vascular endothelial growth factor (VEGF) and transmembrane phosphoglycoprotein protein (CD34) in cerebral cortex (by Western blot) and for examination of the pathological changes (by Nissl staining). Results Compared with Sham group, the neurological deficit score and cerebral infarct volume were significantly increased, and the expression of Gli1, VEGF and CD34 in the cerebral cortex was up-regulated in I/R and ISO groups (P 0.05). Compared with ISO group, the neurological deficit score and cerebral infarct volume were significantly increased, and the expression of Gli1, VEGF and CD34 in the cerebral cortex was down-regulated in ISO+ CYC group (P<0.05). Conclusion The mechanism by which isoflurane post-conditioning attenuates cerebral I/R injury is related to activating Shh signaling pathway and promoting angiogenesis in rats. Key words: Isoflurane; Ischemic postconditioning; Reperfusion injury; Brain; Hedgehog proteins; Angiogenesis

Relationship between spinal Sonic Hedgehog signaling pathway and inflammatory responses in rats with neuropathic pain

Objective To evaluate the relationship between spinal Sonic hedgehog(Shh) signaling pathway and inflammatory responses in rats with neuropathic pain(NP). Methods Forty-eight clean-grade healthy male Sprague-Dawley rats, aged 8 weeks, weighing 250-300 g, were divided into 4 groups(n=12 each) using a random number table method: sham operation group(group S), group NP, dimethyl sulfoxide(DMSO) group(group D) and specific Shh signaling pathway inhibitor cyclopamine group(group CP). Spared nerve injury was produced by exposing the sciatic nerve and branches followed by ligation and transection of tibial and common fibular nerves in anesthetized rats. The mechanical paw withdrawal threshold(MWT) was measured at 1 day before establishing the model and 1 and 7 days after establishing the model., The animals were sacrificed after measurement of pain threshold at 7 days after operation, and the lumbar segment L4-6 of the spinal cord was obtained for determination of the expression of Shh, Patched homolog(Ptch), Smoothened(Smo) and zinc finger-containing transcription factors 1(Gli1)(by Western blot) and contents of tumor necrosis factor-alpha(TNF-α) and interleukin-1beta(IL-1β)(by enzyme-linked immunosorbent assay). Results Compared with group S, the MWT was significantly decreased, the expression of Shh, Patched, Smo and Gli1 was up-regulated, and the contents of TNF-α and IL-1β were increased in NP, D and CP groups(P<0.05). Compared with group NP, the MWT was significantly increased, the expression of Shh, Patched, Smo and Gli1 was down-regulated, and the contents of TNF-α and IL-1β were decreased in group CP(P<0.05), and no significant change was found in the parameters mentioned above in group D(P<0.05). Conclusion The mechanism by which Shh signaling pathway is involved in the development and maintenance of inflammatory responses is related to inhibiting inflammatory responses of the spinal cord in rats with NP. Key words: Neuralgia; Hedgehog proteins; Signal transduction; Inflammation; Spinal cord

Expression and significance of the Hedgehog signal transduction pathway in oxygen-induced retinal neovascularization in mice.

AimThe aim of the study was to investigate the signal transduction mechanism of Hedgehog–vascular endothelial growth factor in oxygen-induced retinopathy (OIR) and the effects of cyclopamine on OIR.MethodsAn OIR model was established in C57BL/6J mice exposed to hyperoxia. Two hundred mice were randomly divided into a control group, an OIR group, an OIR-control group (treated with isometric phosphate-buffered saline by intravitreal injection), and a cyclopamine group (treated with cyclopamine by intravitreal injection), with 50 mice in each group. The retinal vascular morphology was observed using adenosine diphosphatase and number counting using hematoxylin and eosin-stained image. Quantitative real-time quantitative polymerase chain reaction was used to detect mRNA expression. Protein location and expression were evaluated using immunohistochemistry and Western blot.ResultsThe OIR group and OIR-control group demonstrated large-area pathological neovascularization and nonperfused area when compared with the control group (both P<0.05). The area of nonperfusion and neovascularization in the cyclopamine group was significantly reduced compared with the OIR and OIR-control groups (both P<0.05). Compared with the control group, the OIR and OIR-control groups had more vascular endothelial cells breaking through the inner limiting membrane. The number of new blood vessel endothelial cell nuclei in the cyclopamine group was significantly reduced (both P<0.05) when compared with the OIR and OIR-control groups. The mRNA and protein expressions of Smoothened, Gli1, and vascular endothelial growth factor in the signal pathway of the OIR and OIR-control groups were significantly higher than those of the control group; however, in the cyclopamine group, these factors were reduced when compared with the OIR and OIR-control groups (all P<0.05).ConclusionOur data suggest that abnormal expression of the Hedgehog signaling pathway may be closely associated with the formation of OIR. Inhibiting the Smoothened receptor using cyclopamine could control retinal neovascularization, providing new ideas and measures for the prevention of oxygen-induced retinal neovascularization.

Mechanism of Ezhu-containing serum in inhibiting expression of Shh and Gli1 in hepatic stellate cells

To explore the mechanism of Ezhu-containing serum in inhibiting the expression of sonic hedgehog(Shh) and glioma-associated oncogene homolog-1(Gli1) in hepatic stellate cells(HSCs) induced by leptin. Twenty sprague-dawley (SD) rats were randomly divided into 2 groups (n=10), and given Ezhu-decoction and physiological saline by gavage for 10 days to prepare drug-containing serums. The HSCs during the exponential growth phase were divided into 7 groups： blank control group, model group, hedgehog pathway inhibitor(cyclopamine) group, Ezhu group, Ezhu and cyclopamine group, hedgehog pathway agonost(pumorphamine) group, Ezhu and purmorphamine group. HSCs were cultured in vitro and induced with 100 μg•L ⁻¹ leptin(except for the blank control group), then treated separately with the corresponding drugs for 24 hours. After the cells were collected, HSCs proliferation was detected using MTT colorimetric assay; the expressions of Shh and Gli1 were determined by PT-PCR, Western blot and immunofluorescence, respectively. The expressions of Shh and Gli1 were significantly increased after the HSCs of rats were induced by leptin (compared with the blank control group, P<0.01). After being interfered with Hh pathway inhibitor (cyclopamine) and Ezhu-containing serum, the expressions of Shh and Gli1 were decreased significantly(compared with the model group, P<0.01). After Ezhu-containing serum was used to interfere the Hh pathway inhibitor group, the mRNA and protein expressions of Shh and Gli1 were decreased significantly(compared with the model group, P<0.01). After Ezhu-containing serum was used to interfere the purmorphamine group, the mRNA and protein expressions of Shh and Gli1 decreased significantly(compared with the purmorphamine group, P<0.01). Ezhu-containing serum plays an important role in inhibiting HSCs activation by taking part in hedgehog signaling pathway, so as to regulate the expression of Shh and Gli1 in leptin-induced HSCs and then inhibit liver fibrosis.

Role of Shh signal transduction pathway in vascular endothelial growth factor expression under hypoxia in cultured human retinal pigment epithelial cells

Objective To investigate the role of sonic hedgehog (Shh) signal transduction pathway in the expression of vascular endothelial growth factor (VEGF) under hypoxia in cultured human retinal pigment epithelial (hRPE) cells. Methods ARPE-19 were cultured and divided into normal ARPE-19 (Cont) and hypoxia group (100 μmol/L CoCl2 Cobalt Chloride + ARPE-19); hypoxia group was further divided into CoCl2 group, cyclopamine group (CYA) and dimethyl sulfoxide (DMSO) group. 20 μmol/L cyclopamine was added to the CYA group 1 hour before hypoxia, 1‰ DMSO was added into DMSO group at the same time. The hRPE cells were cultured under hypoxia for 4, 8, 12, 24 hours. The expression of Shh and VEGF were determined by Real-time fluorescent quantitate PCR (RT-PCR). The amount of VEGF in the hRPE-conditioned supernatant was measured using enzyme linked immunosorbent assay (ELISA) at 4, 8, 12, 24 hours, respectively. Results RT-PCR tests showed that the level of Shh and VEGF of hRPE was time dependently increased (Shh: F=45.260, P=0.001; VEGF: F=264.938, P=0.001). The level of Shh and VEGF of hRPE in the group treated with cyclopamine was decreased (P<0.01). ELISA tests showed that the amount of VEGF in hRPE supernatant was significantly increased in time-dependent manner (F=3 156.676, P=0.001), and it was down-regulated by cyclopamine under hypoxia (P<0.01). Conclusion Shh signal transduction pathway could play a role in the VEGF expression induced by hypoxia in hRPE cells. Key words: Vascular endothelial growth factors; Retinal pigment epithelium; Cells, cultured

Effect of Danshen-containing serum on expression of SuFu and DYRK2 in HSCs

To observe the effects of Danshen-containing serum on SuFu and DYRK2 expression in the HSCs stimulated by leptin. SD rats (n = 60) were used to make danshen-containing serum by gastric perfusion for ten days with Danshen water decoction, normal saline and colchicine. The HSCs that were cultured in vitro would be stimulated for 24 hours by leptin (100 μg x L(-1)) except blank control group, after being intervened, the drug serum in each group would be cultured at 37 degrees C in 5% incubator. The cells would be collected after 24 hours, then the effects of danshen-containing serum on the proliferation of HSCs were detected by MTT, the expression of SuFu mRNA and DYRK2 mRNA were detected by RT-PCR, the expression of SuFu and DYRK2 proteins were tested by Western blot. Compared with blank control group, the expression of DYRK2 mRNA and DYRK2 proteins were enhanced obviously after stimulated the HSCs of rats by leptin (P < 0.01), but the expression of SuFu mRNA and SuFu proteins were decreased significantly (P < 0.01). Compared with the model group, after cyclopamine group (Hh pathway inhibitor), Danshen-containing serum and colchicine were interfered, the expression of DYRK2 mRNA and DYRK2 proteins were decreased clearly (P < 0.01), but the expression of SuFu mRNA and SuFu proteins were increased significantly (P < 0.01 or P < 0.05). Compared with model group, adding purmorphamine (Hh pathway agonist) to model group and making it activate could increase the expression of DYRK2 mRNA and DYRK2 proteins, but the expression of SuFu mRNA and SuFu proteins were decreased significantly (P < 0.01). Compared with the model group, using the Danshen-containing serum to interfere the purmorphamine group could make the expression of DYRK2 mRNA and DYRK2 proteins decrease and the expression of SuFu mRNA and SuFu proteins increase significantly (P < 0.01). Danshen-containing serum would inhibition the activation and increment of HSCs by interfering the expression of SuFu and DYRK2 which were induced by leptin.

Sonic Hedgehog Signaling: Evidence for Its Protective Role in Endotoxin Induced Acute Lung Injury in Mouse Model.

ObjectiveTo investigate the protective role of the sonic hedgehog (SHH) signaling associated with a lipopolysaccharide (LPS)-induced acute lung injury (ALI) in a mouse model.MethodsMale BALB/c mice were randomly divided into four groups: control, LPS, LPS-cyclopamine group and cyclopamine group. ALI was induced by LPS ip injection (5 mg/kg). The sonic hedgehog inhibitor cyclopamine (50 mg/kg) was given to the LPS-cyclopamine group at 30 min after LPS injection as well as normal mice as control. Lung injury was observed histologically in hematoxylin and eosin (HE) stained tissue sections, semi-quantified by lung tissue injury score, and the lung tissue mass alteration was measured by wet to dry weight ratio (W/D). mRNA expression levels of TNF-α, SHH, Patched (PTC) and GLI1 in lung tissue were studied with real time quantitative PCR (RT-PCR), while the protein expression of SHH and GLI1 was determined by western blot analysis.ResultsLung tissue injury score, thickness of alveolar septa, W/D, and TNF-α mRNA expression levels were significantly higher in the ALI mice than the normal mice (P<0.05). The mRNA expression levels of SHH, PTC, and GLI1 in the ALI mice were significantly higher at 12h and 24h after LPS injection, but not at the 6h time point. Protein production of SHH and GLI1 at 6h, 12h, and 24h in the lungs of ALI mice significantly increased, in a time-dependent manner, compared with that in normal mice. Cyclopamine alone has no effect on pathological changes in normal mice. Intervention with cyclopamine in ALI mice led to a reduction in mRNA levels of SHH, PTC, and GLI1 as well as SHH and GLI1 protein levels; meanwhile, the pathological injury scores of lung tissues, thickness of alveolar septa, W/D, and mRNA expression levels of TNF-α increased compared with mice receiving LPS only.ConclusionThe SHH signaling pathway was activated in response to LPS-induced ALI, and up-regulation of SHH expression could alleviate lung injury and be involved in the repair of injured lung tissue.

Resveratrol inhibits the hedgehog signaling pathway and epithelial-mesenchymal transition and suppresses gastric cancer invasion and metastasis.

The hedgehog (Hh) signaling pathway is vital to vertebrate development, the homeostatic process and tumorigenesis. Epithelial-mesenchymal transition (EMT) is a cellular process during which epithelial cells become mesenchymal-appearing cells, which in turn promotes cancer metastasis and invasion. Resveratrol is a natural polyphenolic compound found in grapes, a variety of berries, peanuts and other plants. Numerous studies have demonstrated that the Hh signaling pathway is able to regulate the EMT, and that resveratrol can suppress carcinoma invasion and metastasis. In addition, certain studies have indicated that resveratrol can inhibit the Hh signaling pathway and EMT in cancers other than gastric cancer. The purpose of the present study was to investigate the inhibitory effect of resveratrol on the Hh signaling pathway and EMT in gastric cancer in vitro. Gastric cancer SGC-7901 cells were treated with resveratrol or cyclopamine at different concentrations. The viability of the cells was assessed using an MTT assay. The expression of Gli-1, a key component of the Hh signaling pathway, and Snail, E-cadherin and N-cadherin, key components of EMT, was detected by reverse transcription polymerase chain reaction (RT-PCR) and western blotting. The invasion and metastasis of the cells were observed by performing a cell scratch test. The RT-PCR and western blotting showed a decrease in Gli-1, Snail and N-cadherin expression, and an increase in E-cadherin expression in the resveratrol and cyclopamine group compared with the control group, suggesting that resveratrol inhibited the Hh pathway and EMT, as did cyclopamine. The MTT assay indicated that the viability of the SGC-7901 cells was significantly decreased in a concentration-dependent manner following resveratrol and cyclopamine treatment. The cell scratch test showed slower cell invasion and metastasis in the resveratrol and cyclopamine groups. These findings indicated that resveratrol was able to inhibit the Hh signaling pathway and EMT, and suppress invasion and metastasis in gastric cancer in vitro.

The sonic hedgehog signaling pathway induces myopic development by activating matrix metalloproteinase (MMP)-2 in Guinea pigs.

PurposeTo investigate whether the Sonic hedgehog (Shh) signaling induces myopic development by increasing the expression of matrix metalloproteinase (MMP)-2 in guinea pigs.MethodsA translucent diffuser was glued onto the right eye to induce form-deprivation myopia (FDM) in 10 guinea pigs. Four guinea pigs were served as a control group. The other 100 guinea pigs were subdivided into 5 groups (20 per group) and received a 10 µl intravitreal injection every 2 days for 4 times. Two groups were injected with 20 or 50 µg/ml Shh amino-terminal peptide (Shh-N) into the right eye and 0.1% bovine serum albumin into the other. FDM was induced in the right eyes of the three cyclopamine-treated groups and both eyes were injected with 50, 100, or 200 µg/ml cyclopamine. Retinoscopic refraction and eye dimensions were assessed on Day 14 of treatment. MMP-2 protein expression was determined in both scleras by western blotting.ResultsBoth concentrations of Shh-N stimulated myopic development and axial growth as compared with control eyes. Myopia and axial elongation were significantly greater in the 50 µg/ml than in the 20 µg/ml Shh-N group (P<0.001 and P = 0.0019, respectively). All three doses of cyclopamine significantly attenuated myopic development compared with the FDM group (P<0.0001). Cyclopamine at 100 or 200 µg/ml significantly reduced axial elongation compared with the FDM group (P = 0.044 and P = 0.001, respectively). FDM-induced myopia and axial elongation were significantly greater in the 50 µg/ml than in the 200 µg/ml cyclopamine group (P<0.0001 and P = 0.008, respectively). MMP-2 expression was significantly greater in Shh-N–treated eyes than in the control eyes, and was lower in the cyclopamine plus FDM groups than in the FDM group.ConclusionsThe Shh signaling pathway induces myopic development by activating MMP-2 in guinea pigs.

Regulatory effects of hedgehog pathway on intestinal epithelial barrier function under hypoxia

Objective To investigate the regulatory effects of hedgehog pathway on intestinal epithelial barrier function under hypoxia.Methods The IEC-6 cells of rats were divided into 3 groups:the normoxia group (21％ oxygen concentration),the hypoxia group (2％ oxygen concentration) and the hypoxia + cyclopamine group (cells pretreated by 5 mmol/L of cyclopamine,and then exposed in an atmosphere with 2％ oxygen concentration).The mRNA expressions of IHH,PTCH and GLI-1 were detected,and the transepithelial electrical resistance (TER) was determined.The protein expressions of tight junction proteins (ZO-1,Occludin,Claudin-1) and IHH were assayed by using the Western blot.All data were analyzed using the one-way analysis of variance or LSD-t test.Results The relative mRNA expressions of IHH,PTCH and GLI-1 were 0.056 ± 0.009,0.459 ± 0.087,0.142 ± 0.023 in the normoxia group,and 0.303 ± 0.052,0.678 ± 0.073,0.483 ± 0.061 in the hypoxia group,with significant difference between the 2 groups (t =-14.05,-11.85,-6.52,P ＜ 0.05).The relative protein expressions of IHH in the normoxia group and the hypoxia group were 0.39 ±0.06 and 0.91 ±0.15,with a significant difference between the 2 groups (t =-8.08,P ＜ 0.05).The TERs of the normoxia group,the hypoxia group and the hypoxia + cyclopamine group were (134 ± 5) Ohm/cm3,(100 ± 6) Ohm/cm3 and (118 ± 5) Ohm/cm3,with significant difference between the 3 groups (F =1.04,P ＜ 0.05).Compared with the normoxia group,the TER of the hypoxia group was decreased by 27.7％ (t =7.84,P ＜ 0.05) ; compared with the hypoxia group,the TER of the hypoxia + cyclopamine group were increased by 16.4％,but it was still significantly lower than the normoxia group (t =4.23,P ＜ 0.05).The expressions of ZO-1,Occludin and Claudin-1 were 1.18 ± 0.24,0.80 ±0.13 and 0.90 ±0.09 in the normoxia group,and 0.58 ±0.08,0.32 ±0.05 and 0.50 ±0.09 in the hypoxia group,and 0.92 ± 0.21,0.43 ± 0.10 and 0.82 ± 0.11 in the hypoxia + cyclopamine group,with significant difference between the 3 groups (F =4.95,2.88,10.09,P ＜0.05).The expressions of ZO-1,Occludin and Claudin-1 in hypoxia group were decreased by 48.7％,40.0％ and 55.6％ when compared with the normoxia group (t =12.86,9.35,18.90,P ＜0.05).The expressions of ZO-1,Occludin and Claudin-1 in the hypoxia + cyclopamine group were increased by 59.9％,35.2％ and 65.1％ when compared with the hypoxia group (t =5.63,2.92,6.66,P ＜ 0.05).Conclusion Hedgehog signal pathway could be activated under hypoxia,and then the expressions of tight junction proteins are decreased,which finally induces the injury of intestinal epithelial barrier function. Key words: Hedgehog signal pathway; Cyclopamine; Epithelial barrier function; Transepithelial electrical resistance; Tight junction proteins

Effect of the Hedgehog-inhibitor cyclopamine on mice with osteosarcoma pulmonary metastases

Chemoresistant metastases of osteosarcoma in humans limit survival in approximately one third of patients. Furthermore, aggressive chemotherapy can lead to side effects and occurrence of secondary malignancies in long time survivors. Therefore, supplemental medical strategies are worthwhile. The well-directed manipulation of cancer-signaling-cascades is an appealing approach. Targeting of the Hedgehog-pathway in cancer has led to promising results in vitro as well as in vivo in a number of different tumor types. Recently, the impact of cyclopamine, which inhibits Hedgehog signaling by binding to the receptor Smoothened, was shown in different human osteosarcoma cell lines in vitro and in vivo. In the present study we examined the influence of cyclopamine on early pulmonary metastases in vivo. Murine osteosarcoma cells, OS-50, were injected into the lateral tail vein of young BALB/c mice. Treatment with subcutaneous cyclopamine injections began after three days. Two weeks later, the animals were sacrificed and the number of pulmonary metastases was counted. We could observe a trend towards decreased metastases in the cyclopamine group (~20%). On the other hand, remarkable side effects were caused by the cyclopamine/ethanol/triolein preparation (mainly skin ulcerations).

Protection from lipopolysaccharide-induced pulmonary microvascular endothelial cell injury by activation of hedgehog signaling pathway

Pulmonary microvascular endothelial cells (PMVECs) are critically involved in the pathogenesis of acute lung injury. Hedgehog signaling pathway plays a fundamental role in embryonic development as well as adult morphogenesis and carcinogenesis. As the priming protein of hedgehog signaling pathway, sonic hedgehog (Shh) may recently be advantage for decreasing endothelial injury and promoting the repair of endothelial barrier function. To investigate the expression and role of hedgehog signal pathway in PMVECs injured by lipopolysaccharide (LPS), cells were divided into six groups: control group, LPS group, rhShh group, LPS+rhShh group, rhShh+cyclopamine group, and LPS+rhShh+cyclopamine group. Real time RT-PCR and Western blotting were used to detect the mRNA and protein expression of hedgehog signal molecules including Shh, Patched-1 (Ptc-1) and Gli1 in nucleus. The activity of PMVECs was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. In this study, we found that Shh, Ptch1, and Gli1 were expressed in rat PMVECs and their expression decreased when cells were treated by LPS. In the other hand, LPS inhibited the activity of rat PMVECs and caused the cells injury. Activation of Hedgehog signaling pathway by Shh could elevate the activity of PMVECs with pretreatment by LPS. Therefore, hedgehog signaling pathway should play a protective role on injury PMVECs by LPS.

Blockade of the sonic hedgehog signalling pathway inhibits choroidal neovascularization in a laser-induced rat model

Sonic hedgehog (Shh) signaling has recently been shown to be involved in the pathological angiogenesis in response to tissue hypoxia and ischemic injury. Hypoxia/ischemia is considered to play an important role in the development of choroidal neovascularization (CNV). This study was aimed to examine the effect of blockade of the Shh signaling pathway on CNV and the underlying mechanism. A total of 64 male Brown-Norway (BN) rats were used in this study. One eye of each rat underwent laser photocoagulation. The other eye served as normal control. After the laser treatment, the 64 rats were divided into four groups (n=16 in each group): Blank control group, in which no intravitreal administration was given; cyclopamine group, recombinant Shh N-terminals protein (rShh) group and phosphate-buffered saline (PBS) group, in which cyclopamine (a Shh inhibitor), rShh (a Shh activator) and PBS were intravitreally injected into the laser-treated eyes respectively every other day for a total of four intravitreal injections immediately after the laser treatment. Fourteen days after the intravitreal administration, the changes of CNV-related variables, including positive CNV lesion percentage, CNV membrane area and CNV membrane thickness, were evaluated by fluorescein angiography, indocyanine green angiography and pathological examinations. The mRNA and protein expression of PTCH1, Gli1, HIF-1(α), VEGF and DLL4 in each group on 14 days of CNV model was detected by real-time quantitative PCR and western blot analysis, and the relationship between the Shh cascade and the HIF-1(α)-VEGF-DLL4 cascade in CNV was analyzed. The results showed that the CNV membrane area and the CNV membrane thickness were decreased by 62.5% and 41.9% in the cyclopamine group and increased by 85.7% and 64.3% in the rShh group in comparison to those in the blank control group (P<0.01 for each). There was no significant difference in the CNV membrane area and thickness between the blank control group and PBS group (P=0.102 and P=0.063, respectively). Real-time quantitative PCR revealed a 5.23-, 4.14-, 2.97-, 2.78- and 2.39-fold up-regulation of the mRNA expression of PTCH1, Gli1, HIF-1(α), VEGF and DLL4 genes in the laser-treated eyes compared with the normal control eyes in the control group. In the cyclopamine group, the mRNA and protein expression of Gli1, HIF-1(α), VEGF and DLL4 was significantly down-regulated (P<0.05 for each) while the expression of PTCH1 showed no significant changes at the mRNA (P=0.293) and protein level (P=0.304). The mRNA expression and protein expression (P=0.001 and P=0.021, respectively) of PTCH1, Gli1, HIF-1(α), VEGF and DLL4 was significantly increased in the rShh group when compared with the control group. The expression level of these genes was related to the severity of the CNV. It was concluded that intravitreal administration of cyclopamine can effectively inhibit the formation of laser-induced experimental CNV by down-regulating the expression of the HIF-1(α)-VEGF-DLL4 cascade in CNV. The Shh signaling pathway as an upstream signaling pathway of HIF-1(α)-VEGF-DLL4 cascade is implicated in the development of experimental CNV.