Home About us Contact
|
Home About us Contact | ||
|
|
||
Hedgehog Signaling (hedgehog + signaling)
Terms modified by Hedgehog Signaling Selected AbstractsAnalysis of Testosterone Effects on Sonic Hedgehog Signaling in Juvenile, Adolescent and Adult Sprague Dawley Rat PenisTHE JOURNAL OF SEXUAL MEDICINE, Issue 3 2010Christopher W. Bond MS ABSTRACT Introduction., Smooth muscle apoptosis is a major contributing factor to erectile dysfunction (ED) development in prostatectomy and diabetic patients and animal models. A critical regulator of penile smooth muscle and apoptosis is Sonic hedgehog (SHH). The SHH protein is decreased in ED models and SHH treatment of cavernous nerve (CN) injured rats prevents smooth muscle apoptosis. A close association between androgen deficiency and ED has been suggested in the literature, but few studies have examined the molecular effects on penile smooth muscle and on known signaling mechanisms that regulate morphology. Aim., Examine testosterone and SHH interaction in eugonadal adult, adolescent and juvenile rats by performing castration studies and treatment with supraphysiological testosterone. Methods., The eugonadal adult Sprague Dawley rats were either treated with testosterone for 7 or 14 days (N = 14) or were castrated for 4 or 7 days (N = 12). The juvenile rats were treated with testosterone for 8 days (N = 7). The adolescent rats were castrated and sacrificed at P88 (N = 8). The control rats had empty vehicle (N = 22) or sham surgery (N = 20). Main Outcome Measures., The active form of SHH protein and mRNA were quantified by semi-quantitative immunohistochemical analysis and real-time reverse transcriptase polymerase chain reaction (RT-PCR). Results., Testosterone treatment did not alter SHH signaling in juvenile rats. Shh mRNA increased 3.2-fold and SHH protein increased 1.2-fold in rats castrated during puberty. In adult rats, castration decreased Shh mRNA 3.2-fold but did not alter SHH protein. Testosterone supplement in adult rats increased Shh mRNA 2.3-fold and decreased SHH protein 1.3-fold. Conclusions., SHH signaling is independent of testosterone in normal juvenile rats and is sensitive to testosterone during adolescence, while testosterone supplement in the adult adversely impacts SHH signaling in a very similar manner to that observed with CN injury. Bond CW, Angeloni NL, and Podlasek CA. Analysis of testosterone effects on sonic hedgehog signaling in juvenile, adolescent and adult Sprague Dawley rat penis. J Sex Med 2010;7:1116,1125. [source] Ventral specification and perturbed boundary formation in the mouse midbrain in the absence of Hedgehog signalingDEVELOPMENTAL DYNAMICS, Issue 5 2008Jennifer L. Fogel Abstract Although Hedgehog (HH) signaling plays a critical role in patterning the ventral midbrain, its role in early midbrain specification is not known. We examined the midbrains of sonic hedgehog (Shh) and smoothened (Smo) mutant mice where HH signaling is respectively attenuated and eliminated. We show that some ventral (Evx1+) cell fates are specified in the Shh,/, mouse in a Ptc1 - and Gli1 -independent manner. HH-independent ventral midbrain induction was further confirmed by the presence of a Pax7 -negative ventral midbrain territory in both Shh,/, and Smo,/, mice at and before embryonic day (E) 8.5. Midbrain signaling centers are severely disrupted in the Shh,/, mutant. Interestingly, dorsal markers are up-regulated (Wnt1, Gdf7, Pax7), down-regulated (Lfng), or otherwise altered (Zic1) in the Shh,/, midbrain. Together with the increased cell death seen specifically in Shh,/, dorsal midbrains (E8.5,E9), our results suggest specific regulation of dorsal patterning by SHH, rather than a simple deregulation due to its absence. Developmental Dynamics 237:1359-1372, 2008. © 2008 Wiley-Liss, Inc. [source] A hypermorphic mouse Gli3 allele results in a polydactylous limb phenotypeDEVELOPMENTAL DYNAMICS, Issue 3 2007Chengbing Wang Abstract Gli3 protein processing to generate the Gli3 repressor is mediated by proteasome and inhibited by Hedgehog signaling. The Gli3 repressor concentration is graded along the anterior,posterior axis of the developing vertebrate limb due to posteriorly restricted Sonic hedgehog expression. In this study, we created a small deletion at the Gli3 locus (Gli3,68), which causes a half reduction in the Gli3 repressor levels and a slightly increased activity of full-length mutant protein in the limb. Mice homozygous for Gli3,68 develop one to two extra partial digits in the anterior of the limb, while mice carrying one copy of the Gli3,68 allele die soon after birth and display seven digits. These phenotypes are more severe than those found in mice lacking one wild-type Gli3 allele. The expression of dHand, Hoxd12, and Hoxd13 is anteriorly expanded in the limb, even though no up-regulation of Gli1 and Ptc RNA expression is detected. These findings suggest that a decrease in the Gli3 repressor level in combination with an increase in Gli3 full-length activity results in more severe digit patterning abnormalities than those caused by a loss of one wild-type Gli3 allele. Developmental Dynamics 236:769,776, 2007. © 2007 Wiley-Liss, Inc. [source] Long-term establishment, characterization and manipulation of cell lines from mouse basal cell carcinoma tumorsEXPERIMENTAL DERMATOLOGY, Issue 9 2006Po-Lin So Abstract:, There have been few reports of successful long-term culture of cells established from cutaneous basal cell carcinoma (BCC) tumors. Here, we describe techniques that have enabled us to establish three long-term cultures of BCC cells isolated from BCC tumors that arose in irradiated Patched 1 (Ptch1)+/, mice. All three cell lines showed cellular morphology similar to that of BCC tumors and could be propagated for at least 20 passages. In addition, similar to BCC tumors, all cell lines had lost the wildtype Ptch1 allele, expressed BCC molecular markers, and responded similarly to cyclopamine, a small molecule inhibitor of Hedgehog signaling. Finally, we describe an efficient electroporation technique for DNA transfection into the BCC cell lines and show that they have activated Hedgehog signaling activity, albeit at a level lower than that of murine BCCs in vivo. These data indicate that the cell lines are bona fide long-term cultures of BCC cells and that DNA plasmids can be introduced into the BCC cell lines with relatively high transfection efficiency using a modified electroporation technique. [source] Hedgehog signaling maintains hair follicle stem cell phenotype in young and aged human skinAGING CELL, Issue 6 2009Laure Rittié Summary Skin hair follicles (HF) contain bulge stem cells (SC) that regenerate HFs during hair cycles, and repair skin epithelia following injury. As natural aging is associated with decreased skin repair capacity in humans, we have investigated the impact of age on human scalp HF bulge cell number and function. Here, we isolated human bulge cells, characterized as CD200+/KRT15+/KRT19+ cells of the HF, by dissection-combined CD200 selection in young and aged human skin. Targeted transcriptional profiling indicates that KRT15, KRT19, Dkk3, Dkk4, Tcf3, S100A4, Gas1, EGFR and CTGF/CCN2 are also preferentially expressed by human bulge cells, compared to differentiated HF keratinocytes (KC). Our results demonstrate that aging does not alter expression or localization of these HF SC markers. In addition, we could not detect significant differences in HF density or bulge cell number between young and aged human scalp skin. Interestingly, hedgehog (Hh) signaling is activated in human bulge cells in vivo, and down-regulated in differentiated HF KCs, both in young and aged skin. In addition, activation of Hh signaling by lentivirus-mediated overexpression of transcription factor Gli1 induces transcription of HF SC markers KRT15, KRT19, and Gas1, in cultured KCs. Together with previously reported knock-out mouse results, these data suggest a role for Hh signaling in maintaining bulge cell phenotype in young and aged human skin. [source] Ellis,van Creveld syndrome and Weyers acrodental dysostosis are caused by cilia-mediated diminished response to hedgehog ligands,AMERICAN JOURNAL OF MEDICAL GENETICS, Issue 4 2009Victor L. Ruiz-Perez Abstract Ellis,van Creveld syndrome (EvC; OMIM 225500) is a recessive disorder comprising chondrodysplasia, polydactyly, nail dysplasia, orofacial abnormalities and, in a proportion of patients, cardiovascular malformations. Weyers acrodental dysostosis (Weyers; OMIM 193530) is an allelic dominant disorder comprising polydactyly, nail dysplasia, and orofacial abnormalities. EvC results from loss-of-function mutations in EVC or EVC2, the phenotype associated with the mutations in these two genes being indistinguishable. Three convincing causative mutations have been identified in patients with Weyers acrodental dysostosis, which are clustered in the last coding exon of EVC2 and lead to production of a truncated protein lacking the final 43 amino acids. Localization and function of EVC and EVC2 are inferred from studying the murine orthologs. Both Evc and Evc2 proteins localize to the basal bodies of primary cilia and analysis of an Ellis,van Creveld mouse model, which includes the limb shortening and tooth abnormalities of EvC patients, has demonstrated Hedgehog signaling defects in the absence of Evc. The loss of Evc2 has not been studied directly, but Hedgehog signaling is impaired when a mutant murine Evc2 Weyer variant is expressed in vitro. We conclude that the phenotypic abnormalities in EvC and Weyers syndrome result from tissue specific disruption of the response to Hh ligands. © 2009 Wiley-Liss, Inc. [source] Sonic and desert hedgehog signaling in human fetal prostate development,THE PROSTATE, Issue 6 2007Guodong Zhu Abstract Background Hedgehog signaling is thought to play an important role in rodent prostate organogenesis and morphogenesis. However, the role of this signaling pathway in human fetal prostate development has not been investigated. Methods Twenty-five human fetal prostates at various developmental stages (10,39 weeks) were included. Fifteen specimens were processed for H&E and immunohistochemical staining of the Hedgehog signaling components: Sonic Hedgehog (SHH), Desert Hedgehog (DHH), Patched-1(PTC1), Patched-2 (PTC2), Smoothened (SMO), GLI1, and proliferating cell nuclear antigen (PCNA). SHH, DHH, and GLI1 expression was also analyzed in ten snap-frozen specimens by Western blot. Results SHH, DHH, SMO, PTC1, GLI1, and PCNA expression, assessed by a semi-quantitative immunohistochemical method, was found mainly in the developing prostatic epithelial ducts, beginning at 10 weeks and peaking at 16 and 28 weeks with a dip occurring at 20 weeks, with the exception of PTC2. Conclusion Both SHH and DHH signaling components were detected during human fetal prostate development. Despite the high expression of PTC2 in the epithelium as well as the stroma in the early time of development, the expression of SHH, DHH, SMO, PTC1, and a SHH/DHH target transcription factor, GLI-1, were all largely restricted to epithelium in the developing prostate, suggesting that SHH/DHH signaling is primarily through an autocrine mechanism in human fetal prostate organogenesis. Prostate 67: 674,684, 2007. © 2007 Wiley-Liss, Inc. [source] Sonic hedgehog derived from human pancreatic cancer cells augments angiogenic function of endothelial progenitor cellsCANCER SCIENCE, Issue 6 2008Madoka Yamazaki Hedgehog signaling is important in the pathogenesis of pancreatic cancer. Several recent observations suggest the involvement of sonic hedgehog (SHH) in postnatal neovascularization. We identified a novel role for SHH in tumor-associated angiogenesis in pancreatic cancer. Immunohistochemical analysis revealed that patched homolog 1 (PTCH1), both a receptor for and transcriptional target of hedgehog signaling, was expressed in a small fraction of endothelial cells within pancreatic cancer, but not in normal pancreatic tissue. When endothelial progenitor cells (EPC) isolated from human peripheral blood were cultured with supernatant from SHH-transfected 293 cells or pancreatic cancer cells, mRNA levels of vascular endothelial growth factor (VEGF), stromal cell-derived factor-1 and angiopoietin-1 were significantly increased, whereas no such induction was observed in human umbilical vein endothelial cell (HUVEC) and human dermal microvascular endothelial cell (HMVEC). HUVEC tube formation was stimulated when cocultured with EPC, and preconditioning EPC with supernatant from KP-1 N pancreatic cancer cells highly expressing SHH significantly enhanced the effect. The effect was partially attenuated by specific inhibition of SHH with cyclopamine or a neutralizing antibody. These findings suggest that tumor-derived SHH can induce angiogenesis, and this is mediated by its effects on EPC specifically. Targeting SHH would be a novel therapeutic approach that can inhibit not only proliferation of cancer cells but also EPC-mediated angiogenesis. (Cancer Sci 2008; 99: 1131,1138) [source] A Small-Molecule Antagonist of the Hedgehog Signaling PathwayCHEMBIOCHEM, Issue 16 2007Jongkook Lee Dr. Shadow the Hedgehog. JK184 (illustrated in the scheme) was identified as an antagonist of Hedgehog signaling through a cell-based screen of chemical libraries. Results from biochemical and cellular experiments suggest that JK184 functions by inhibiting class IV alcohol dehydrogenase. This molecule should serve as a useful tool for studying Hedgehog signaling. [source] Hedgehog signaling and congenital malformationsCLINICAL GENETICS, Issue 3 2005E Nieuwenhuis The Hedgehog (Hh)-signaling pathway is essential for numerous developmental processes in Drosophila and vertebrate embryos. Hh signal transduction encompasses a complex series of regulatory events, including the generation of the mature Hh ligand, propagation of the ligand from source of production as well as the reception and interpretation of the signal in Hh-receiving cells. Many congenital malformations in humans are known to involve mutations in various components of the Hh-signaling pathway. This mini review summarizes some recent findings about the regulation of Hh signal transduction and describes the spectrum of human congenital malformations that are associated with aberrant Hh signaling. Based on a comparison of mouse-mutant phenotypes and human syndromes, we discuss how Hh-dependent Gli activator and repressor functions contribute to some of the congenital malformations. [source] Coordinated regulation of dorsal bone morphogenetic protein 4 and ventral Sonic hedgehog signaling specifies the dorso-ventral polarity in the optic vesicle and governs ocular morphogenesis through fibroblast growth factor 8 upregulationDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 4 2010Takuma Kobayashi Dorsal and ventral specification in the early optic vesicle plays a crucial role in vertebrate ocular morphogenesis, and proper dorsal-ventral polarity in the optic vesicle ensures that distinct structures develop in separate domains within the eye primordium. The polarity is determined progressively during development by coordinated regulation of extraocular dorsal and ventral factors. In the present study, we cultured discrete portions of embryonic chick brains by preparing anterior cephalon, anterior dorsal cephalon and anterior ventral cephalon, and clearly demonstrate that bone morphogenetic protein 4 (BMP4) and Sonic hedgehog (Shh) constitute a dorsal-ventral signaling system together with fibroblast growth factor 8 (FGF8). BMP4 and Shh upregulate Tbx5 and Pax2, as reported previously, and at the same time Shh downregulates Tbx5, while BMP4 affects Pax2 expression to downregulate similarly. Shh induces Fgf8 expression in the ventral optic vesicle. This, in turn, determines the distinct boundary of the retinal pigmented epithelium and the neural retina by suppressing Mitf expression. The lens develops only when signals from both the dorsal and ventral regions come across together. Inverted deposition of Shh and BMP4 signals in organ-cultured optic vesicle completely re-organized ocular structures to be inverted. Based on these observations we propose a novel model in which the two signals govern the whole of ocular development when they encounter each other in the ocular morphogenic domain. [source] Tulp3 is a critical repressor of mouse hedgehog signalingDEVELOPMENTAL DYNAMICS, Issue 5 2009Don A. Cameron Abstract Precise regulation of the morphogen sonic hedgehog (Shh) and modulation of the Shh signaling pathway is required for proper specification of cell fate within the developing limbs and neural tube, and resultant tissue morphogenesis. Tulp3 (tubby-like protein 3) is a protein of unknown function which has been implicated in nervous system development through gene knockout studies. We demonstrate here that mice lacking the Tulp3 gene develop abnormalities of both the neural tube and limbs consistent with improper regulation of Shh signaling. Tulp3,/, embryos show expansion of Shh target gene expression and display a ventralization of neural progenitor cells in the caudal neural tube. We further show that Tulp3,/,/Shh,/, compound mutant embryos resemble Tulp3 mutants, and express Shh target genes in the neural tube and limbs which are not expressed in Shh,/, embryos. This work uncovers a novel role for Tulp3 as a negative regulatory factor in the Hh pathway. Developmental Dynamics 238:1140,1149, 2009. © 2009 Wiley-Liss, Inc. [source] Expression of the NET family member Zfp503 is regulated by hedgehog and BMP signaling in the limbDEVELOPMENTAL DYNAMICS, Issue 4 2008Edwina McGlinn Abstract The NET/Nlz family of zinc finger transcription factors contribute to aspects of developmental growth and patterning across evolutionarily diverse species. To date, however, these molecules remain largely uncharacterized in mouse and chick. We previously reported that limb bud expression of Zfp503, the mouse orthologue of zebrafish nlz2/znf503, is dependent on Gli3. Here, we show that Zfp503/Znf503 is expressed in a restricted pattern during mouse and chick embryogenesis, with particularly dynamic expression in the developing limbs, face, somites, and brain. We also add to our previous data on Gli3 regulation by showing that the anterior domain of Zfp503 expression in the mouse limb is responsive to genetic and nongenetic manipulation of hedgehog signaling. Finally, we demonstrate that posterior expression of Znf503 in the chick limb is responsive to bone morphogenetic protein (BMP) signaling, indicating that Zfp503/Znf503 may act at the nexus of multiple signaling pathways in development. Developmental Dynamics 237:1172,1182, 2008. © 2008 Wiley-Liss, Inc. [source] Acute experimental colitis and human chronic inflammatory diseases share expression of inflammation-related genes with conserved Ets2 binding sitesINFLAMMATORY BOWEL DISEASES, Issue 2 2009Tineke C.T.M. van der Pouw Kraan PhD Abstract Background: Ulcerative colitis (UC) and Crohn's disease (CD) are characterized by chronic inflammation of the gastrointestinal tract, with overlapping clinical characteristics and unknown etiology. We reasoned that in intestinal inflammation the initial activation of the innate immune response fails to resolve, finally resulting in uncontrolled chronic inflammatory bowel disease. Methods: To identify the early inflammatory events in colitis that remain active in human chronic colitis, we analyzed the changes of the colonic transcriptome during acute experimental colitis and compared the outcome with previously published profiles of affected tissues from patients with UC and CD, and as a control for intestinal inflammation in general, tissues from celiac disease patients. Rheumatoid arthritis synovial tissues were included as a nonintestinal inflammatory disease. The expression profiles of each disease were analyzed separately, in which diseased tissues were compared to unaffected tissues from the same anatomical location. Results: Gene ontology analysis of significantly regulated genes revealed a marked activation of immunity and defense processes in all diseases, except celiac disease, where immune activation is less prominent. The control region of upregulated genes contained an increase in Ets2 binding sites in experimental colitis, UC, and rheumatoid arthritis, and were associated with upregulated immune activity. In contrast, upregulated genes in celiac disease harbored the transcription factor binding site GLI, which binds to the Gli family of transcription factors involved in hedgehog signaling, affecting development and morphogenesis. Conclusion: Ets2 may be an important transcription factor driving inflammation in acute as well as chronic inflammatory disease. (Inflamm Bowel Dis 2008) [source] Gene silencing of transcription factor Gli2 inhibits basal cell carcinomalike tumor growth in vivoINTERNATIONAL JOURNAL OF CANCER, Issue 1 2008Jingmin Ji Abstract Basal cell carcinoma (BCC) belongs worldwide to the most frequent malignancy among Caucasians. The understanding of the molecular mechanisms of BCC formation, which is a prerequisite for the development of efficient new therapies, is still incomplete. The formation of sporadic BCCs in the skin is associated with uncontrolled hedgehog signaling, and the transcription factor Gli2 has been identified as a key mediator or effector of this signaling. There is indication in the literature that preventing Gli2 function may inhibit BCC formation and growth in vivo; however, the mechanism is unclear and difficult to study in humans. Therefore, we used a mouse tumor allograft model to investigate the role of Gli2 in tumor formation. A constitutively Gli2 expressing mouse tumor cell line was stably transfected with Gli2-specific shRNA to induce Gli2 gene silencing or with control shRNA. Injecting the Gli2 gene silenced cells into nude mice for tumor formation we detected a strongly retarded tumor growth compared with control tumor cells. Investigating the mechanisms, we found that Gli2 gene silencing has led to the disruption of the tumor structure as demonstrated by staining tumor sections with hematoxylin. Two main reasons for the tumor destruction were identified. We found that apoptosis was markedly increased while vascularization was strongly decreased in these tumors. Thus, important functions of the transcription factor Gli2 in this tumor model are the prevention of apoptosis and the promotion of microvascularization. © 2007 Wiley-Liss, Inc. [source] Microarray analysis of murine limb bud ectoderm and mesoderm after exposure to cadmium or acetazolamideBIRTH DEFECTS RESEARCH, Issue 7 2009Claire M. Schreiner Abstract BACKGROUND: A variety of drugs, environmental chemicals, and physical agents induce a common limb malformation in the offspring of pregnant mice exposed on day 9 of gestation. This malformation, postaxial, right-sided forelimb ectrodactyly, is thought to arise via an alteration of hedgehog signaling. METHODS: We have studied two of these teratogens, acetazolamide and cadmium, using the technique of microarray analysis of limb bud ectoderm and mesoderm to search for changes in gene expression that could indicate a common pathway to postaxial limb reduction. RESULTS: Results indicated a generalized up-regulation of gene expression after exposure to acetazolamide but a generalized down-regulation due to cadmium exposure. An intriguing observation was a cadmium-induced reduction of Mt1 and Mt2 expression in the limb bud mesoderm indicating a lowering of embryonic zinc. CONCLUSIONS: We propose that these two teratogens and others (valproic acid and ethanol) lower sonic hedgehog signaling by perturbation of zinc function in the sonic hedgehog protein. Birth Defects Research (Part A), 2009. © 2009 Wiley-Liss, Inc. [source] Sonic hedgehog derived from human pancreatic cancer cells augments angiogenic function of endothelial progenitor cellsCANCER SCIENCE, Issue 6 2008Madoka Yamazaki Hedgehog signaling is important in the pathogenesis of pancreatic cancer. Several recent observations suggest the involvement of sonic hedgehog (SHH) in postnatal neovascularization. We identified a novel role for SHH in tumor-associated angiogenesis in pancreatic cancer. Immunohistochemical analysis revealed that patched homolog 1 (PTCH1), both a receptor for and transcriptional target of hedgehog signaling, was expressed in a small fraction of endothelial cells within pancreatic cancer, but not in normal pancreatic tissue. When endothelial progenitor cells (EPC) isolated from human peripheral blood were cultured with supernatant from SHH-transfected 293 cells or pancreatic cancer cells, mRNA levels of vascular endothelial growth factor (VEGF), stromal cell-derived factor-1 and angiopoietin-1 were significantly increased, whereas no such induction was observed in human umbilical vein endothelial cell (HUVEC) and human dermal microvascular endothelial cell (HMVEC). HUVEC tube formation was stimulated when cocultured with EPC, and preconditioning EPC with supernatant from KP-1 N pancreatic cancer cells highly expressing SHH significantly enhanced the effect. The effect was partially attenuated by specific inhibition of SHH with cyclopamine or a neutralizing antibody. These findings suggest that tumor-derived SHH can induce angiogenesis, and this is mediated by its effects on EPC specifically. Targeting SHH would be a novel therapeutic approach that can inhibit not only proliferation of cancer cells but also EPC-mediated angiogenesis. (Cancer Sci 2008; 99: 1131,1138) [source] The ups and downs of holoprosencephaly: dorsal versus ventral patterning forcesCLINICAL GENETICS, Issue 5 2008M Fernandes Holoprosencephaly (HPE), characterized by incomplete separation of forebrain and facial components into left and right sides, is a common developmental defect in humans. It is caused by both genetic and environmental factors and its severity covers a wide spectrum of phenotypes. The genetic interactions underlying inherited forms of HPE are complex and poorly understood. Animal models, in particular mouse mutants, are providing a growing understanding of how the forebrain develops and how the cerebral hemispheres become split into left and right sides. These insights, along with the characterization to date of some of the genes involved in human HPE, suggest that two distinct mechanisms underlie the major classes of HPE, ,classic' and midline interhemispheric (MIH). Disruption either directly or indirectly of the ventralizing effect of sonic hedgehog signaling appears central to all or most forms of classic HPE, while disruption of the dorsalizing effect of bone morphogenetic protein signaling may be key to cases of MIH HPE. [source] | |||||||||||||