Sonic Hedgehog Expression Research Articles

CagA+ Helicobacter pylori induces proliferation and expression of Sonic hedgehog in fundic organoid model (1119.4)

Helicobacter pylori (H. pylori) infection leads to aberrant cell proliferation and dysregulated Hedgehog signaling in the stomach. The organoid model is an emerging in vitro system whereby isolated gastric glands are cultured into three‐dimensional spheres that express cells present in the original tissue. This model allows for the study of epithelial responses to infection in a system independent of recruited inflammatory cells. We hypothesize that H. pylori induces cell proliferation and acute expression of Sonic hedgehog (Shh) in the fundic organoid model in the absence of recruited circulating host factors. Fundic organoids were generated from dissociated gastric glands of control or transgenic mice lacking Shh expression in the parietal cell (PC‐ShhKO). Expression of mature cell lineage markers was confirmed by RT‐PCR and immunofluorescence staining. Colonization and epithelial attachment was confirmed by silver stain, live‐imaging and quantitative re‐culture. Organoids injected with cagA+ but not cagA‐deficient H. pylori had significantly increased cell proliferation as measured by EdU staining. Proliferation was associated with c‐Met phosphorylation as determined by western blot. H. pylori induced Shh at 1 day post‐injection in control organoids but not those generated from PC‐ShhKO mice, and this effect was inhibited by NFκB inhibition. Inhibition of CXCL1/2 signaling, a putative mediator of Shh induction, did not block H. pylori‐induced Shh expression. This report demonstrates a uniquely beneficial in vitro approach to study the host response to H. pylori interactions with the gastric epithelium, independent of recruited hematopoietic factors. Fundic organoids recapitulate the in vivo responses to H. pylori of cell proliferation and Shh induction and provide mechanistic insight demonstrating 1) cagA dependence and c‐Met phosphorylation association with H. pylori‐induced proliferation and 2) NFκB requirement for H. pylori‐induced gastric Shh expression.Grant Funding Source: Supported by NIH 1R01DK083402‐01 (Y. Zavros) and AGA: Funderburg Research Award (Y. Zavros)

Exploration of the effects of Doublethumb on neural tube development (541.7)

Neural tube defects (NTDs) occur in approximately 1 in every 1000 births. NTDs have both an environmental and genetic basis. A hypomorphic mutation of the PCP effector protein gene Inturned (Intudtm/dtm) was studied to determine its effects on ciliogenesis, cranial neural tube patterning, and cell proliferation in a mouse model. Heterozygous mice carrying the Intudtm allele were bred and mothers were sacked and dissected for embryos. Embryos (n=6) at embryonic day 10.5 were fixed, embedded in Optimum Cutting Temperature, and cryosectioned into 10 m slices. PCR was used to distinguish between Intu+/+ and Intudtm/dtm embryos. Immunofluorescence was performed then analyzed using confocal microscopy and FIJI analysis software. Ciliogenesis, Sonic Hedgehog expression, certain patterning markers and transcription factors required for embryonic and fetal development, and cell proliferation were all decreased in Intudtm/dtm. Cell differentiation was unaffected in Intudtm/dtm compared to Intu+/+. Thus, there are biological effects of the hypomorphic mutation of Inturned. Future work is needed to increase the number of biological and technical replicates, as well as to quantitate the expression of these and other markers at varying time points in embryonic development.Grant Funding Source: Supported by the Howard Hughes Medical Institute and the LSU‐HHMI program.

Role of EST2/ETV5 as transcription factors in the regulation of SHH by FGF (541.3)

During limb development, fibroblast growth factors (FGFs) from the apical ectodermal ridge (AER) regulate the expression of Sonic hedgehog (SHH) in the underlying posterior distal mesoderm. The molecules or pathways involved in the regulation of SHH by FGF are unknown. A recent study suggests that ETS and ETV, members of the ETS transcription factor family, are intermediate regulators in the Fgf to Shh cascade and directly interact with the limb‐specific Shh regulatory region in the murine limb model.To determine whether this was a conserved function of ETS/ETV transcription factors, we used the chick model and examined ETS2/ETV5 expression by in situ hybridization following ectopic application of FGF in the posterior limb bud, an assay known to induce SHH.ETV5 is expressed in the distal mesoderm sub‐adjacent to the AER and overlaps the SHH expression domain. ETS2 expression is most prominent in the developing chick zeugopod and appears to correlate with the condensing radius and ulna. The posterior expression of ETS2 is more robust than its anterior expression. Both factors show increased expression around ectopically applied FGF2‐laden beads at 24 hours after bead implantation.These data demonstrate expression patterns that spatially complement and overlap the SHH expression domain. Furthermore, both factors are upregulated by ectopic FGF prior to or coincident with SHH upregulation. These data support a role for ETS transcription factors in the regulation of SHH by FGF.

The evolution of the vertebrate cerebellum: absence of a proliferative external granule layer in a non‐teleost ray‐finned fish

The cerebellum represents one of the most morphologically variable structures in the vertebrate brain. To shed light on its evolutionary history, we have examined the molecular anatomy and proliferation of the developing cerebellum of the North American paddlefish, Polyodon spathula. Absence of an external proliferative cerebellar layer and the restriction of Atonal1 expression to the rhombic lip and valvular primordium demonstrate that transit amplification in a cerebellar external germinal layer, a prominent feature of amniote cerebellum development, is absent in paddlefish. Furthermore, expression of Sonic hedgehog, which drives secondary proliferation in the mouse cerebellum, is absent from the paddlefish cerebellum. These data are consistent with what has been observed in zebrafish and suggest that the transit amplification seen in the amniote cerebellum was either lost very early in the ray-finned fish lineage or evolved in the lobe-finned fish lineage. We also suggest that the Atoh1-positive proliferative valvular primordium may represent a synapomorphy (shared derived character) of ray-finned fishes. The topology of valvular primordium development in paddlefish differs significantly from that of zebrafish and correlates with the adult cerebellar form. The distribution of proliferative granule cell precursors in different vertebrate taxa is thus the likely determining factor in cerebellar morphological diversity.

Transcription of the SCL/TAL1 Interrupting Locus (Stil) Is Required for Cell Proliferation in Adult Zebrafish Retinas

The human oncogene SCL/TAL1 interrupting locus (Stil) is highly conserved in vertebrate species. Previously, we identified a homolog of the Stil gene in zebrafish mutant (night blindness b, nbb), which showed neural defects in the retina (e.g. dopaminergic cell degeneration and/or lack of regeneration). In this research, we examined the roles of Stil in cell proliferation after degeneration in adult zebrafish retinas. We demonstrated that knockdown of Stil gene expression or inhibition of Sonic hedgehog (Shh) signaling transduction decreases the rate of cell proliferation. In contrast, activation of Shh signal transduction promotes cell proliferation. In nbb(+/-) retinas, inhibition of SUFU (a repressor in the Shh pathway) rescues the defects in cell proliferation due to down-regulation of Stil gene expression. The latter data suggest that Stil play a role in cell proliferation through the Shh signal transduction pathway.

Autism Associated Gene, ENGRAILED2, and Flanking Gene Levels Are Altered in Post-Mortem Cerebellum

BackgroundPrevious genetic studies demonstrated association between the transcription factor ENGRAILED2 (EN2) and Autism Spectrum Disorder (ASD). Subsequent molecular analysis determined that the EN2 ASD-associated haplotype (rs1861972-rs1861973 A-C) functions as a transcriptional activator to increase gene expression. EN2 is flanked by 5 genes, SEROTONIN RECEPTOR5A (HTR5A), INSULIN INDUCED GENE1 (INSIG1), CANOPY1 HOMOLOG (CNPY1), RNA BINDING MOTIF PROTEIN33 (RBM33), and SONIC HEDGEHOG (SHH). These flanking genes are co-expressed with EN2 during development and coordinate similar developmental processes. To investigate if mRNA levels for these genes are altered in individuals with autism, post-mortem analysis was performed.MethodsqRT-PCR quantified mRNA levels for EN2 and the 5 flanking genes in 78 post-mortem cerebellar samples. mRNA levels were correlated with both affection status and rs1861972-rs1861973 genotype. Molecular analysis investigated whether EN2 regulates flanking gene expression.Results EN2 levels are increased in affected A-C/G-T individuals (p = .0077). Affected individuals also display a significant increase in SHH and a decrease in INSIG1 levels. Rs1861972-rs1861973 genotype is correlated with significant increases for SHH (A-C/G-T) and CNPY1 (G-T/G-T) levels. Human cell line over-expression and knock-down as well as mouse knock-out analysis are consistent with EN2 and SHH being co-regulated, which provides a possible mechanism for increased SHH post-mortem levels.Conclusions EN2 levels are increased in affected individuals with an A-C/G-T genotype, supporting EN2 as an ASD susceptibility gene. SHH, CNPY1, and INSIG1 levels are also significantly altered depending upon affection status or rs1861972-rs1861973 genotype. Increased EN2 levels likely contribute to elevated SHH expression observed in the post-mortem samples

A Dual Role for SHH during Phallus Development in a Marsupial

The mammalian phallus arises from identical primordia in both sexes and is patterned in part by the key morphogen Sonic hedgehog (SHH). We have investigated SHH and other morphogens during phallus development in the tammar wallaby. In this marsupial, testis differentiation and androgen production occurs just after birth, but it takes a further 50-60 days before the phallus becomes sexually dimorphic. One day before birth, SHH was expressed in both sexes in the urethral epithelium. In males, there was a marked upregulation of SHH, GLI2, and AR at day 50 postpartum, a time when testicular androgen production falls. SHH, GLI2, and AR were downregulated in female pouch young treated with androstanediol from days 24-50, but not when treatments were begun at day 29, suggesting an early window of androgen sensitivity. SHH, GLI2, and AR expression in the phallus of males castrated at day 23 did not differ from controls, but there was an increase in SHH and GLI2 and a decrease in FGF8 and BMP4 expression when the animals were castrated at day 29. These results suggest that the early patterning by SHH is androgen-independent followed by an androgen-dependent window of sensitivity and a sharp rise in SHH expression after androgen withdrawal at day 50.

Mouse Model Reveals the Role of RERE in Cerebellar Foliation and the Migration and Maturation of Purkinje Cells

Nuclear receptors and their coregulators play a critical role in brain development by regulating the spatiotemporal expression of their target genes. The arginine-glutamic acid dipeptide repeats gene (Rere) encodes a nuclear receptor coregulator previously known as Atrophin 2. In the developing cerebellum, RERE is expressed in the molecular layer, the Purkinje cell layer and the granule cell layer but not in granule cell precursors. To study RERE's role in cerebellar development, we used RERE-deficient embryos bearing a null allele (om) and a hypomorphic allele (eyes3) of Rere (Rere om/eyes3). In contrast to wild-type embryos, formation of the principal fissures in these RERE-deficient embryos was delayed and the proliferative activity of granule cell precursors (GCPs) was reduced at E18.5. This reduction in proliferation was accompanied by a decrease in the expression of sonic hedgehog (SHH), which is secreted from Purkinje cells and is required for normal GCP proliferation. The maturation and migration of Purkinje cells in Rere om/eyes3 embryos was also delayed with decreased numbers of post-migratory Purkinje cells in the cerebellum. During the postnatal period, RERE depletion caused incomplete division of lobules I/II and III due to truncated development of the precentral fissure in the cerebellar vermis, abnormal development of lobule crus I and lobule crus II in the cerebellar hemispheres due to attenuation of the intercrural fissure, and decreased levels of Purkinje cell dendritic branching. We conclude that RERE-deficiency leads to delayed development of the principal fissures and delayed maturation and migration of Purkinje cells during prenatal cerebellar development and abnormal cerebellar foliation and Purkinje cell maturation during postnatal cerebellar development.

Sonic hedgehog expression in a rat model of chronic pancreatitis.

To analyze the activation of sonic hedgehog (SHh) signaling pathways in a rat model of chronic pancreatitis. Forty Wistar rats were randomly divided into 2 groups: experimental group and control group (20 rats in each group). Dibutyltin dichloride was infused into the tail vein of the rats to induce chronic pancreatitis in the experimental group. The same volume of ethanol and glycerol mixture was infused in the control group. The expression of Ptch, Smo and Gli were analyzed using immunohistochemistry, and real-time reverse transcription polymerase chain reaction (RT-PCR). Compared with the control group, significant histological changes in terms of the areas of abnormal architecture, glandular atrophy, fibrosis, pseudo tubular complexes, and edema were observed at week 4 in the experimental group. The expression of Ptch1, Smo and Gli1 in the pancreatic tissue increased significantly in the experimental group. Using RT-PCR, mRNA levels of Ptch, Smo and Gli in the experimental group increased significantly compared with the control group. The SHh signaling pathway is aberrantly activated in rats with chronic pancreatitis. The SHh signaling pathway plays an important role in the development of chronic pancreatitis. These results may be helpful in studies focusing on the relationship between chronic pancreatitis and pancreatic cancer.

Association of aldehyde dehydrogenase 1 expression and biologically aggressive features in breast cancer

Aldehyde dehydrogenase 1 (ALDH1) has been regarded as a breast cancer stem cell marker. Several studies have reported that ALDH1 expression is associated with poor prognosis in breast cancer. We aimed, therefore, to determine the prognostic value of ALDH1 expression and its association with several biomarkers in breast cancer tissue using immunohistochemistry. Furthermore, we investigated the characteristics of and differences between cellular and stromal expression of ALDH1. We performed tissue microarray (TMA) analysis of 425 breast cancer tissue samples collected during surgery. Immunohistochemical staining was then performed to measure the expression of ALDH1 and other breast cancer biomarkers. Statistical analysis of the relationship between ALDH1 expression and clinicopathologic characteristics was performed for 390 TMA samples. We found that ALDH1 was expressed in 71 cases (18.2%) in the tumor cells and/or stroma. Of these cases, 38 (9.7%) showed ALDH1 expression in tumor cells and 38 (9.7%) showed ALDH1 expression in the stroma. ALDH1 expression was significantly associated with markers of a poor prognosis, such as young age, estrogen receptor negativity, progesterone receptor negativity, a high histological grade, and a high Ki-67 index. However, ALDH1 expression was not associated with p53, transforming growth factor-beta, Gli-1, YKL-40, or sonic hedgehog expression status. With regard to the expression site, the clinical characteristics did not differ between cases of cellular expression and those of stromal expression. However, ALDH1 expression in tumor cells was correlated with hormone receptor status, histological grade, molecular subtype, epidermal growth factor receptor expression status, and cytokeratin 5/6 expression status while stromal expression of ALDH1 was only correlated with hormone receptor status. Overall, these findings suggest that ALDH1 expression in tumor tissue is associated with a biologically aggressive phenotype. ALDH1, biologically aggressive, breast cancer.

Expression of Sonic Hedgehog in non-small cell lung cancer and its relationship with the cycle of life

Objective To observe the expression of Sonic Hedgehog (Shh) signaling pathway related protein in patients with non-small cell lung cancer and explore their roles in the development of lung cancer.Methods Forty-six patients with non-small cell lung cancer undergoing surgical operation were selected in our hospital from January to June,2013,which were operation resection of lung cancer as the observation group,39 cases the tissue of adjacent to carcinoma,28 cases of lung tissue with no lung cancer as control group.Using immunohistochemical method to observe the Shh and Gli2 protein expression.Results Shh and Gli1 protein in the cells were expressed in the cytoplasm under light microscope,yellow or brown yellow.The positive rate of Shh and Gli1 protein in the observe group were respectively 73.91％ (34/46) and 67.40％ (31/46),were higher than that in paracancerous tissues and the control group (P ＜0.05),The positive rate of Shh and Gli1 protein in Ⅲ,ⅣWstage were 80.95％ (17/21),71.43％(15/21) and 91.67％ (11/12),83.33％ (10/12),were higher than those of Ⅰ and Ⅱ phase (P ＜ 0.05).Conclusion In Shh signal pathway,there may be through the activation of Shh protein and the expression of Gli protein which promote carcinogenesis and cell proliferation in non-small cell lung cancer. Key words: Sonic Hedgehog pathway; Non small cell lung cancer; Shh protein; Gli1 protein

Application of synthetic photostable retinoids induces novel limb and facial phenotypes during chick embryogenesisin vivo

We have recently developed a range of synthetic retinoid analogues which include the compounds EC23 and EC19. They are stable on exposure to light and are predicted to be resistant to the normal metabolic processes involved in the inactivation of retinoids in vivo. Based on the position of the terminal carboxylic acid groups in the compounds we suggest that EC23 is a structural analogue of all-trans retinoic acid (ATRA), and EC19 is an analogue of 13-cis retinoic acid. Their effects on the differentiation of pluripotent stem cells has been previously described in vitro and are consistent with this hypothesis. We present herein the first description of the effects of these molecules in vivo. Retinoids were applied to the anterior limb buds of chicken embryos in ovo via ion-exchange beads. We found that retinoid EC23 produces effects on the wing digits similar to ATRA, but does so at two orders of magnitude lower concentration. When larger quantities of EC23 are applied, a novel phenotype is obtained involving production of multiple digit 1s on the anterior limb. This corresponds to differential effects of ATRA and EC23 on sonic hedgehog (shh) expression in the developing limb bud. With EC23 application we also find digit 1 phenotypes similar to thumb duplications described in the clinical literature. EC23 and ATRA are shown to have effects on the entire proximal–distal axis of the limb, including hitherto undescribed effects on the scapula. This includes suppression of expression of the scapula marker Pax1. EC23 also produces effects similar to those of ATRA on the developing face, producing reductions of the upper beak at concentrations two orders of magnitude lower than ATRA. In contrast, EC19, which is structurally very similar to EC23, has novel, less severe effects on the face and rarely alters limb development. EC19 and ATRA are effective at similar concentrations. These results further demonstrate the ability of retinoids to influence embryonic development. Moreover, EC23 represents a useful new tool to investigate developmental processes and probe the mechanisms underlying congenital abnormalities in vertebrates including man.

Substance P attenuates hyperoxia-induced lung injury in neonatal rats

The aim of the study was to investigate the effects of substance P (SP) in hyperoxia‑induced lung injury in newborn rats and to elucidate its protective mechanism of action via the sonic hedgehog (SHH) signaling pathway. Twelve‑hour‑old neonatal Sprague‑Dawley rats were randomly divided into one of four groups: air, hyperoxia, air + SP and hyperoxia + SP. In a separate set of experiments, the neonatal rat pups were exposed to 21 or 95% O2 for 14 days with or without intraperitoneal administration of rat SP. The animals were sacrificed at 3, 7 and 14 days, respectively, of hyperoxia exposure. Lung pathology and grade of lung tissue injury were examined by light microscopy. Oxidative stress was evaluated by malondialdehyde (MDA) and antioxidant activity was measured by superoxide dismutase (SOD) in tissue homogenates. The expression of SHH mRNA and protein were detected by quantitative polymerase chain reaction (qPCR) and western blot analysis, respectively. In the hyperoxia group, marked characteristics of acute lung injury (ALI) were observed. Compared with the simple hyperoxia treatment, the lung damage was significantly ameliorated following the addition of SP. Furthermore, the levels of MDA were decreased and SOD was significantly increased following the addition of SP. SP stimulation may result in activation of the SHH signaling pathway and the expression of SHH markedly increased following treatment with SP. The present study demonstrated that SP protected against the hyperoxia‑induced lung damage by attenuating oxidative stress, elevating the antioxidant activities and upregulating the signaling pathway of SHH.

Hedgehog Pathway Is Deregulated In Myelodysplastic Syndrome Progenitor Bone Marrow Cells

The sonic hedgehog (Shh) pathway is a regulatory network involved in the development of cancer. The Hh ligands (Sonic Hh, Indian Hh, and Desert Hh) bind to the receptors Patched1 and Patched2, resulting in the inhibition of their repression on Smoothened (Smo). Smo is a seven-transmembrane protein, which inhibits Suppressor of Fused (SUFU), resulting in the stabilization and activation of the Gli family of transcription factors, followed by a transcriptional response to the “canonical Hh signaling”. SUFU is a negative regulator of the Hedgehog signaling pathway, through the restriction of Gli activity through cytoplasmic sequestration. Germline mutations in SUFU are involved in medulloblastoma. Dysregulation of Shh signaling has been reported to be involved in several malignancies, including chronic myeloid leukemia.To our knowledge, however, only one study has been carried out in myelodysplastic syndrome (MDS) and acute leukemia so far, and the role of this pathway in leukemogenesis is still unknown. Recently we showed an increased protein expression of Sonic and Dessert Hedgehog in addition to increased mRNA levels of PTCH and SMO in MDS bone marrow. Here, we investigated whether this increase was capable of activating Hedgehog pathway in total and in progenitor bone marrow cells.Bone marrow (BM) samples were collected from 39 MDS (25 low-risk, 14 high-risk, according WHO 2008) patients and 26 healthy donors. CD34+ cells were isolated from peripheral blood of 9 healthy donors and 20 (12 low-risk and 8 high risk) MDS patients. Relative expressions of PTCH, SMO, SUFU and GLI1 were obtained by Real time-PCR.Increased expression observed in ligands and receptors were not sufficient to upregulate the activity of Hedgehog pathway in MDS total bone marrow. The downstream effector GLI1 was under expressed in the disease as median [min-max] as follows: healthy donors 1.04[0.02-4.01]; low risk MDS 0.21[0.03-2.26]; high risk MDS 0.07[0.03-1.48] healthy donors vs low risk p=0.007; healthy donors vs high risk p=0.006. Furthermore, SUFU expression was similar in healthy donors 3.3[0.35-7.84] and in myelodysplastic (low risk 3.76[0.75-13, 2] and high risk 1.8[0.58-16.4]) bone marrows. Different from total bone marrow, the receptors Patched and SMO showed decreased expression in MDS CD34+ cells: Patched healthy donors 2.24[0.74-4.36]; low risk 0.6[0.1-3.34]; high risk 0.98[0.29-1.22] and SMO healthy donors 1.18[0.62-2.16]; low risk 0.79[0,11-1.87]; high risk 0.86[0.37-1.02]; healthy donors vs high risk MDS p=0.049. SUFU was overexpressed (healthy donors 1.44[0.75-2.39]; low risk 2.77[0.93-4.11]; high risk 1.68[1.07-3.43]; healthy donors vs low risk MDS p=.005). However, myelodysplastic progenitors had GLI1 overexpression (healthy donors 1.09[0.6-2.91]; low risk 2.93[0.75-14.52]; high risk 1.32[0.71-2.58]; healthy donors vs low risk p=0.03), indicating an activation of the Shh pathway in MDS progenitors.Recently, Kobune et al (Blood Cancer J. 2012 Sep 7) showed activation of Hedgehog signaling in primary CD34+ blasts from acute myeloid leukemia and MDS, as those cells expressed IHh, PTCH, SMO, GLI1 and GLI. Taken together, these results and ours led us to conclude that the Hedgehog pathway is activated in MDS. Since Shh pathway is being explored as a new opportunity for targeted therapies against tumors, our study suggests that the inhibition of this pathway could be strategic in the control of leukemic stem cell and MDS treatment. Disclosures:No relevant conflicts of interest to declare.

Lgr4 is a key regulator of prostate development and prostate stem cell differentiation

Mechanisms modulating prostate cell fate determination remain unexplored. The leucine-rich repeat containing G-protein-coupled receptors (Lgr) have been identified as important stem cell markers in various tissues. Here, we investigated the roles of Lgr4/Gpr48 in prostate stem cells (PSCs) and development. Lgr4 was ubiquitously expressed during early prostate development prior to lineage specification, with adult expression restricted to a few basal cells (principally Lin(-)Sca1(+)CD49f(+)). Lgr4(-/-) mice had compromised branching morphogenesis and delayed epithelial differentiation, leading to decreased prostate size and impaired luminal cell function. In vitro prostate sphere culture revealed that Lgr4(-/-) Lin(-)/Sca1(+)/CD49f(+) cells failed to generate p63(low) cells, indicating a differentiation deficiency. Furthermore, Lgr4 ablation arrested PSC differentiation of in vivo kidney capsule prostate grafts, suggesting that Lgr4 modulates PSC properties independent of hormonal and mesenchymal effects. Analysis of neonatal prostates and prostate spheres revealed a decrease in Wnt, Sonic Hedgehog, and Notch1 expression in Lgr4(-/-) cells. Lgr4 loss blocked differentiation of prostate sphere p63(hi) cells to p63(low). Treatment with exogenous Sonic Hedgehog partially restored the differentiation of p63(hi) cells in Lgr4(-/-) spheres. Taken together, our data revealed the roles of Lgr4 in early prostate development and in stem cell differentiation through regulation of the Wnt, Notch, and Sonic Hedgehog signaling pathways.

Sonic Hedgehog Regulates Osteoblast Function by Focal Adhesion Kinase Signaling in the Process of Fracture Healing

Several biological studies have indicated that hedgehog signaling plays an important role in osteoblast proliferation and differentiation, and sonic hedgehog (SHH) expression is positively correlated with phosphorylated focal adhesion kinase (FAK) Tyr397. However, the relationship between them and their role in the process of normal fracture repair has not been clarified yet. Immunohistochemical analysis revealed that SHH and pFAK Tyr397 were expressed in bone marrow cells and that pFAK Tyr397 was also detected in ALP-positive osteoblasts near the TRAP-positive osteoclasts in the fracture site in the ribs of mice on day 5 after fracture. SHH and pFAK Tyr397 were detectable in osteoblasts near the hypertrophic chondrocytes on day 14. In vitro analysis showed that SHH up-regulated the expression of FAK mRNA and pFAK Tyr397 time dependently in osteoblastic MC3T3-E1 cells. Functional analysis revealed that 5 lentivirus encoding short hairpin FAK RNAs (shFAK)-infected MC3T3-E1 cell groups displayed a round morphology and decreased proliferation, adhesion, migration, and differentiation. SHH stimulated the proliferation and differentiation of MC3T3-E1 cells, but had no effect on the shFAK-infected cells. SHH also stimulated osteoclast formation in a co-culture system containing MC3T3-E1 and murine CD11b+ bone marrow cells, but did not affect the shFAK-infected MC3T3-E1 co-culture group. These data suggest that SHH signaling was activated in osteoblasts at the dynamic remodeling site of a bone fracture and regulated their proliferation and differentiation, as well as osteoclast formation, via FAK signaling.

Longitudinal Analysis of Calorie Restriction on Rat Taste Bud Morphology and Expression of Sweet Taste Modulators

Calorie restriction (CR) is a lifestyle intervention employed to reduce body weight and improve metabolic functions primarily via reduction of ingested carbohydrates and fats. Taste perception is highly related to functional metabolic status and body adiposity. We have previously shown that sweet taste perception diminishes with age; however, relatively little is known about the effects of various lengths of CR upon taste cell morphology and function. We investigated the effects of CR on taste bud morphology and expression of sweet taste-related modulators in 5-, 17-, and 30-month-old rats. In ad libitum (AL) and CR rats, we consistently found the following parameters altered significantly with advancing age: reduction of taste bud size and taste cell numbers per taste bud and reduced expression of sonic hedgehog, type 1 taste receptor 3 (T1r3), α-gustducin, and glucagon-like peptide-1 (GLP-1). In the oldest rats, CR affected a significant reduction of tongue T1r3, GLP-1, and α-gustducin expression compared with age-matched AL rats. Leptin receptor immunopositive cells were elevated in 17- and 30-month-old CR rats compared with age-matched AL rats. These alterations of sweet taste-related modulators, specifically during advanced aging, suggest that sweet taste perception may be altered in response to different lengths of CR.

Changes in synaptic transmission and protein expression in the brains of adult offspring after prenatal inhibition of the kynurenine pathway

During early brain development, N-methyl-d-aspartate (NMDA) receptors are involved in cell migration, neuritogenesis, axon guidance and synapse formation, but the mechanisms which regulate NMDA receptor density and function remain unclear. The kynurenine pathway of tryptophan metabolism includes an agonist (quinolinic acid) and an antagonist (kynurenic acid) at NMDA receptors and we have previously shown that inhibition of the pathway using the kynurenine-3-monoxygenase inhibitor Ro61-8048 in late gestation produces rapid changes in protein expression in the embryos and effects on synaptic transmission lasting until postnatal day 21 (P21). The present study sought to determine whether any of these effects are maintained into adulthood. After prenatal injections of Ro61-8048 the litter was allowed to develop to P60 when some offspring were euthanized and the brains removed for examination. Analysis of protein expression by Western blotting revealed significantly reduced expression of the GluN2A subunit (32%) and the morphogenetic protein sonic hedgehog (31%), with a 29% increase in the expression of doublecortin, a protein associated with neurogenesis. No changes were seen in mRNA abundance using quantitative real-time polymerase chain reaction. Neuronal excitability was normal in the CA1 region of hippocampal slices but paired-pulse stimulation revealed less inhibition at short interpulse intervals. The amount of long-term potentiation was decreased by 49% in treated pups and recovery after low-frequency stimulation was delayed. The results not only strengthen the view that basal, constitutive kynurenine metabolism is involved in normal brain development, but also show that changes induced prenatally can affect the brains of adult offspring and those changes are quite different from those seen previously at weaning (P21). Those changes may be mediated by altered expression of NMDAR subunits and sonic hedgehog.

Hedgehog-signaling is upregulated in non-producing human adrenal adenomas and antagonism of hedgehog-signaling inhibits proliferation of NCI-H295R cells and an immortalized primary human adrenal cell line

Hedgehog (Hh)-signaling pathway is important in embryonic development. Activation of Hh-signaling is associated with tumorigenesis. Recent studies demonstrate that Hh-signaling is involved in the development of the adrenal gland in mice and is important in regulating adrenal proliferation.We studied the expression of Sonic hedgehog (SHH), Smoothened (SMO), Patched1 (PTCH1) and GLI family zinc finger 1 (GLI1) in human adrenal and in adrenocortical tumors using immunohistochemistry and semi-quantitative reverse transcriptase-polymerase chain reaction. Modulation of GLI1 and SMO messenger ribonucleic acid (mRNA) expression was investigated with forskolin. The role of Hh-signaling was studied in NCI-H295R cells and in an immortalized primary cell line using the Hh-agonist smoothened agonist (SAG) and the Hh-antagonist cyclopamine.The Hh-pathway components SHH, GLI1, PTCH1 and SMO were detectable in all adrenal glands. While in cortisol-producing adenomas (CPA), Hh-signaling expression levels were comparable to that in normal adrenal cortex, a much higher mRNA expression of GLI1, SMO and SHH was observed in non-producing adenomas (NPA). Interestingly, stimulation of cultured adrenal cells with forskolin led to a decrease in expression of GLI1 and SMO mRNAs. Antagonism of Hh-signaling resulted in a lower proliferation rate of adrenocortical cells, while Hh-agonism had no significant effect on adrenal cell proliferation.Our data show Hh-signaling activity in adult adrenal glands. Activation of the PKA pathway results in lower expression of Hh-signaling proteins. This might explain the lower expression of the Hh components GLI1 and SMO in CPA in comparison to the higher expression in NPA. Hh-signaling might be involved in the tumorigenesis of NPA.

FGF10 Signaling differences between type I pleuropulmonary blastoma and congenital cystic adenomatoid malformation

BackgroundType I pleuropulmonary blastoma (PPB) and congenital cystic adenomatoid malformation of the lung (CCAM) are cystic lung diseases of childhood. Their clinical and radiological presentations are often similar, and pathologic discrimination remains difficult in many cases. As a consequence, type I PPB and CCAM are frequently confused, leading to delayed adequate management for type I PPB. Recent studies have suggested a role for fibroblast growth factor (FGF) 10 signal pathway in CCAM pathogenesis. The objective of our study was to determine whether FGF10 signaling differs between CCAM and type I PPB.MethodsImmunohistochemical studies were performed for expression of FGF10, its receptor FGFR2b, and its inhibitor sonic hedgehog (SHH) in focal type I PPB (n=6), CCAM type I (n=7), CCAM type II (n=7), and control lungs (n=5).ResultsFGF10, FGFR2b, and SHH expressions differed markedly between type I PPB and both types of CCAM. Type I and type II CCAM cystic walls expressed FGF10, FGFR2b, and SHH, whereas staining was absent or poor in type I PBB cystic walls. Expression of FGF10, FGFR2b, and SHH did not differ between CCAM cystic walls and control airway walls.ConclusionsThese findings show that immunohistochemistry with FGF10, FGFR2b, or SHH could be useful in differentiating CCAM from type I PPB, when a child presents with a focal cystic lung lesion. The absence of strong expression of FGF10, FGFR2b, and/or SHH makes the diagnosis of CCAM very doubtful.