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Objective To investigate the effect of different fluid shear stress (FSS) on the regulation of planar cell polarity (PCP) signaling, and further to explore the relationship among FSS, PCP signaling pathway and ciliogenesis. Methods The hydrodynamic cell model of adjustable FSS was established. qPCR and immunofluorescence were used to detect the mRNA expression of PCP signaling pathway core protein Dvl2 and cilia assembly protein IFT88, cell targeting and co-localization under different FSS. Western blot (WB) was used to detect the protein expression of Dvl2 at 18 h under different FSS. Results The qPCR result showed that compared with 1.5 Pa FSS, under 0.1 Pa FSS, the mRNA expression of Dvl2 was higher at 6 h and 18 h (P＜0.05), significantly higher at 12 h (P＜0.01); the mRNA expression of IFT88 was significantly higher at 18 h (P＜0.01). The WB result showed that compared with 0 h, under 0.1 Pa FSS, the protein expression of Dvl2 was higher at 18 h (P＜0.05), significantly lower under 1.5 Pa FSS (P＜0.01); compared with 1.5 Pa FSS, the protein expression of Dvl2 was higher at 18 h under 0.1 Pa FSS (P＜0.05). The immunofluorescence result showed that the positive expression of Dvl2 increased with the loading time on FSS increasing, and gradually aggregated at a point around the nucleus; the positive expression of IFT88 was gradually transferred from the nucleus to the cytoplasm and aggregated at a point under 0.1 Pa FSS, and gradually decreased and depolymerized under 1.5 Pa FSS. Protein Dvl2 and IFT88 were located in the same position in cells under 0.1 Pa FSS and before 18 h under 1.5 Pa FSS, and colocalization of proteins Dvl2 and IFT88 was not observed after 18 h under 1.5 Pa FSS due to IFT88 depolymerization. Conclusions Laminar FSS played an inhibition on the transduction of PCP signaling pathway and a hindrance on the process of ciliogenesis, while low FSS played a promotion on the transduction. PCP signaling pathway might regulate FSS-induced ciliogenesis by Dvl2.
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@#Regarded as a complex biological process, lens development involves a range of signal molecules and their crosstalk networks. Recently,the role of planar cell polarity(PCP)signaling pathway in lens development has attracted increasing attention. It has been reported that PCP is critical for lens morphology and transparency maintaining. The studies performed on PCP serve to provide guidelines on how to optimize the morphology of regenerated lens. This is thought as presenting an effective therapy for infant cataract from a clinical perspective. This article will give a comprehensive review of the role of PCP signaling pathways in the lens development.
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Objective To investigate the role of β-catenin,the core protein of canonical Wnt/β-catenin signaling,in the inner-ear development and polarity regulation.Methods β-catenin was conditionally deleted from precursor cells of inner-ear sensory epithelium (Sox2-positive cells) in embryonic mice.Morphological changes of the inner ear were observed.Immunofluorescence staining was performed to basilar membranes,utricles and saccules to observe the hair-cell changes in arrangement and polarity.Results Compared with the control group,knock-out of β-catenin in Sox2-positive cells resulted in smaller otic vesicles,cochleas and vestibules,and fewer hair cells (HCs) in vestibular sensory epithelium (P＜0.01).Stereocilium showed misorientation and kinocillia had a change in location and quantity in the cochlea.Scattered misorented HCs were also observed in the vestibule.Conclusions β-catenin is crucial for the development of inner ear and polarity manipulation of HCs in mice.The canonical Wnt/β-catenin signaling may be involved in the regulation of cochlea extension and planar cell polarity (PCP) of inner ear,which is known to be controlled by non-canonical Wnt/PCP signaling.
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Background@#Valproic acid (VPA) exposure during pregnancy has been proven to contribute to congenital heart disease (CHD). Our previous findings implied that disruption of planar cell polarity (PCP) signaling pathway in cardiomyocytes might be a factor for the cardiac teratogenesis of VPA. In addition, the teratogenic ability of VPA is positively correlated to its histone deacetylase (HDAC) inhibition activity. This study aimed to investigate the effect of the VPA on cardiac morphogenesis, HDAC1/2/3, and PCP key genes (Vangl2/Scrib/Rac1), subsequently screening out the specific HDACs regulating PCP pathway.@*Methods@#VPA was administered to pregnant C57BL mice at 700 mg/kg intraperitoneally on embryonic day 10.5. Dams were sacrificed on E15.5, and death/absorption rates of embryos were evaluated. Embryonic hearts were observed by hematoxylin-eosin staining to identify cardiac abnormalities. H9C2 cells (undifferentiated rat cardiomyoblasts) were transfected with Hdac1/2/3 specific small interfering RNA (siRNA). Based on the results of siRNA transfection, cells were transfected with Hdac3 expression plasmid and subsequently mock-treated or treated with 8.0 mmol/L VPA. Hdac1/2/3 as well as Vangl2/Scrib/Rac1 mRNA and protein levels were determined by real-time quantitative polymerase chain reaction and Western blotting, respectively. Total HDAC activity was detected by colorimetric assay.@*Results@#VPA could induce CHD (P 0.05); VPA exposure dramatically decreased the expression of Vanlg2/Scrib together with Hdac activity (P 0.05).@*Conclusion@#VPA could inhibit Hdac1/2/3, Vangl2/Scrib, or total Hdac activity both in vitro and in vivo and Hdac3 might participate in the process of VPA-induced cardiac developmental anomalies.
Subject(s)
Animals , Female , Mice , Pregnancy , Rats , Cell Polarity , Enzyme Inhibitors , Fetal Heart , Embryology , Heart Defects, Congenital , Histone Deacetylase Inhibitors , Histone Deacetylases , Physiology , Mice, Inbred C57BL , Nerve Tissue Proteins , Transfection , Valproic AcidABSTRACT
GIPC1, GIPC2 and GIPC3 consist of GIPC homology 1 (GH1) domain, PDZ domain and GH2 domain. The regions around the GH1 and GH2 domains of GIPC1 are involved in dimerization and interaction with myosin VI (MYO6), respectively. The PDZ domain of GIPC1 is involved in interactions with transmembrane proteins [IGF1R, NTRK1, ADRB1, DRD2, TGFbetaR3 (transforming growth factorbeta receptor type III), SDC4, SEMA4C, LRP1, NRP1, GLUT1, integrin alpha5 and VANGL2], cytosolic signaling regulators (APPL1 and RGS19) and viral proteins (HBc and HPV-18 E6). GIPC1 is an adaptor protein with dimerizing ability that loads PDZ ligands as cargoes for MYO6-dependent endosomal trafficking. GIPC1 is required for cell-surface expression of IGF1R and TGFbetaR3. GIPC1 is also required for integrin recycling during cell migration, angiogenesis and cytokinesis. On early endosomes, GIPC1 assembles receptor tyrosine kinases (RTKs) and APPL1 for activation of PI3K-AKT signaling, and G protein-coupled receptors (GPCRs) and RGS19 for attenuation of inhibitory Galpha signaling. GIPC1 upregulation in breast, ovarian and pancreatic cancers promotes tumor proliferation and invasion, whereas GIPC1 downregulation in cervical cancer with human papillomavirus type 18 infection leads to resistance to cytostatic transforming growth factorbeta signaling. GIPC2 is downregulated in acute lymphocytic leukemia owing to epigenetic silencing, while Gipc2 is upregulated in estrogen-induced mammary tumors. Somatic mutations of GIPC2 occur in malignant melanoma, and colorectal and ovarian cancers. Germ-line mutations of the GIPC3 or MYO6 gene cause nonsyndromic hearing loss. As GIPC proteins are involved in trafficking, signaling and recycling of RTKs, GPCRs, integrins and other transmembrane proteins, dysregulation of GIPCs results in human pathologies, such as cancer and hereditary deafness.