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Wang Q, Shen ZN, Zhang SJ, Sun Y, Zheng FJ, Li YH. Protective effects and mechanism of puerarin targeting PI3K/Akt signal pathway on neurological diseases. Front Pharmacol 2022; 13:1022053. [PMID: 36353499 PMCID: PMC9637631 DOI: 10.3389/fphar.2022.1022053] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 10/10/2022] [Indexed: 07/22/2023] Open
Abstract
Neurological diseases impose a tremendous and increasing burden on global health, and there is currently no curative agent. Puerarin, a natural isoflavone extracted from the dried root of Pueraria montana var. Lobata (Willd.) Sanjappa and Predeep, is an active ingredient with anti-inflammatory, antioxidant, anti-apoptotic, and autophagy-regulating effects. It has great potential in the treatment of neurological and other diseases. Phosphatidylinositol 3-kinases/protein kinase B (PI3K/Akt) signal pathway is a crucial signal transduction mechanism that regulates biological processes such as cell regeneration, apoptosis, and cognitive memory in the central nervous system, and is closely related to the pathogenesis of nervous system diseases. Accumulating evidence suggests that the excellent neuroprotective effect of puerarin may be related to the regulation of the PI3K/Akt signal pathway. Here, we summarized the main biological functions and neuroprotective effects of puerarin via activating PI3K/Akt signal pathway in neurological diseases. This paper illustrates that puerarin, as a neuroprotective agent, can protect nerve cells and delay the progression of neurological diseases through the PI3K/Akt signal pathway.
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Affiliation(s)
| | | | | | | | | | - Yu-Hang Li
- *Correspondence: Feng-Jie Zheng, ; Yu-Hang Li,
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2
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Tariq K, Luikart BW. Striking a balance: PIP 2 and PIP 3 signaling in neuronal health and disease. EXPLORATION OF NEUROPROTECTIVE THERAPY 2022; 1:86-100. [PMID: 35098253 PMCID: PMC8797975 DOI: 10.37349/ent.2021.00008] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Phosphoinositides are membrane phospholipids involved in a variety of cellular processes like growth, development, metabolism, and transport. This review focuses on the maintenance of cellular homeostasis of phosphatidylinositol 4,5-bisphosphate (PIP2), and phosphatidylinositol 3,4,5-trisphosphate (PIP3). The critical balance of these PIPs is crucial for regulation of neuronal form and function. The activity of PIP2 and PIP3 can be regulated through kinases, phosphatases, phospholipases and cholesterol microdomains. PIP2 and PIP3 carry out their functions either indirectly through their effectors activating integral signaling pathways, or through direct regulation of membrane channels, transporters, and cytoskeletal proteins. Any perturbations to the balance between PIP2 and PIP3 signaling result in neurodevelopmental and neurodegenerative disorders. This review will discuss the upstream modulators and downstream effectors of the PIP2 and PIP3 signaling, in the context of neuronal health and disease.
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Affiliation(s)
- Kamran Tariq
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
| | - Bryan W Luikart
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
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3
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Venkata PP, Chen Y, Alejo S, He Y, Palacios BE, Loeffel I, Liu J, Pratap UP, Gray G, Achuthan Pillai SM, Zou Y, Lai Z, Suzuki T, Viswanadhapalli S, Palakurthi S, Tekmal RR, Vadlamudi RK, Kost E, Sareddy GR. KDM1A inhibition augments the efficacy of rapamycin for the treatment of endometrial cancer. Cancer Lett 2022; 524:219-231. [PMID: 34673129 PMCID: PMC10000284 DOI: 10.1016/j.canlet.2021.10.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 09/30/2021] [Accepted: 10/13/2021] [Indexed: 11/21/2022]
Abstract
Endometrial cancer (EC) often exhibit aberrant activation of PI3K/Akt/mTOR signaling and targeted therapies using mTOR inhibitors showed limited success. The epigenetic modifier, lysine-specific histone demethylase-1A (KDM1A/LSD1) is overexpressed in EC, however, the mechanistic and therapeutic implications of KDM1A in EC are poorly understood. Here, using 119 FDA-approved drugs screen, we identified that KDM1A inhibition is highly synergistic with mTOR inhibitors. Combination therapy of KDM1A and mTOR inhibitors potently reduced the cell viability, survival, and migration of EC cells. Mechanistic studies demonstrated that KDM1A inhibition attenuated the activation of mTOR signaling cascade and abolished rapamycin induced feedback activation of Akt. RNA-seq analysis identified that KDM1A inhibition downregulated the expression of genes involved in rapamycin induced activation of Akt, including the mTORC2 complex. Chromatin immunoprecipitation experiments confirmed KDM1A recruitment to the promoter regions of mTORC2 complex genes and that KDM1A inhibition promoted enrichment of repressive H3K9me2 marks at their promoters. Combination therapy of KDM1A inhibitor and rapamycin reduced the tumor growth in EC xenograft and patient derived xenograft models in vivo and patient derived tumor explants ex vivo. Importantly, in silico analysis of TCGA EC patients data sets revealed that KDM1A expression positively correlated with the levels of PI3K/Akt/mTOR genes. Collectively, our results provide compelling evidence that KDM1A inhibition potentiates the activity of mTOR inhibitors by attenuating the feedback activation of Akt survival signaling. Furthermore, the use of concurrent KDM1A and mTOR inhibitors may be an attractive targeted therapy for EC patients.
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Affiliation(s)
- Prabhakar Pitta Venkata
- Department of Obstetrics and Gynecology, University of Texas Health San Antonio, San Antonio, TX, 78229, USA
| | - Yihong Chen
- Department of Obstetrics and Gynecology, University of Texas Health San Antonio, San Antonio, TX, 78229, USA; Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, PR China
| | - Salvador Alejo
- Department of Obstetrics and Gynecology, University of Texas Health San Antonio, San Antonio, TX, 78229, USA
| | - Yi He
- Department of Obstetrics and Gynecology, University of Texas Health San Antonio, San Antonio, TX, 78229, USA; Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, PR China
| | - Bridgitte E Palacios
- Department of Obstetrics and Gynecology, University of Texas Health San Antonio, San Antonio, TX, 78229, USA
| | - Ilanna Loeffel
- Department of Obstetrics and Gynecology, University of Texas Health San Antonio, San Antonio, TX, 78229, USA
| | - Junhao Liu
- Department of Obstetrics and Gynecology, University of Texas Health San Antonio, San Antonio, TX, 78229, USA; Department of Oncology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, PR China
| | - Uday P Pratap
- Department of Obstetrics and Gynecology, University of Texas Health San Antonio, San Antonio, TX, 78229, USA
| | - Gabrielle Gray
- Department of Obstetrics and Gynecology, University of Texas Health San Antonio, San Antonio, TX, 78229, USA
| | | | - Yi Zou
- Greehey Children's Cancer Research Institute, University of Texas Health San Antonio, San Antonio, TX, 78229, USA
| | - Zhao Lai
- Greehey Children's Cancer Research Institute, University of Texas Health San Antonio, San Antonio, TX, 78229, USA; Department of Molecular Medicine, University of Texas Health San Antonio, San Antonio, TX, 78229, USA
| | - Takayoshi Suzuki
- The Institute of Scientific and Industrial Research, Osaka University, Japan
| | - Suryavathi Viswanadhapalli
- Department of Obstetrics and Gynecology, University of Texas Health San Antonio, San Antonio, TX, 78229, USA
| | - Srinath Palakurthi
- Department of Pharmaceutical Sciences, Texas A&M University, Kingsville, TX, 78363, USA
| | - Rajeshwar R Tekmal
- Department of Obstetrics and Gynecology, University of Texas Health San Antonio, San Antonio, TX, 78229, USA; Mays Cancer Center, University of Texas Health San Antonio, San Antonio, TX, 78229, USA
| | - Ratna K Vadlamudi
- Department of Obstetrics and Gynecology, University of Texas Health San Antonio, San Antonio, TX, 78229, USA; Mays Cancer Center, University of Texas Health San Antonio, San Antonio, TX, 78229, USA; Audie L. Murphy Division, South Texas Veterans Health Care System, San Antonio, TX 78229, USA
| | - Edward Kost
- Department of Obstetrics and Gynecology, University of Texas Health San Antonio, San Antonio, TX, 78229, USA
| | - Gangadhara R Sareddy
- Department of Obstetrics and Gynecology, University of Texas Health San Antonio, San Antonio, TX, 78229, USA; Mays Cancer Center, University of Texas Health San Antonio, San Antonio, TX, 78229, USA.
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4
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Zhang M, Duffen JL, Nocka KH, Kasaian MT. IL-13 Controls IL-33 Activity through Modulation of ST2. THE JOURNAL OF IMMUNOLOGY 2021; 207:3070-3080. [PMID: 34789557 DOI: 10.4049/jimmunol.2100655] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 10/13/2021] [Indexed: 12/12/2022]
Abstract
IL-33 is a multifunctional cytokine that mediates local inflammation upon tissue damage. IL-33 is known to act on multiple cell types including group 2 innate lymphoid cells (ILC2s), Th2 cells, and mast cells to drive production of Th2 cytokines including IL-5 and IL-13. IL-33 signaling activity through transmembrane ST2L can be inhibited by soluble ST2 (sST2), which acts as a decoy receptor. Previous findings suggested that modulation of IL-13 levels in mice lacking decoy IL-13Rα2, or mice lacking IL-13, impacted responsiveness to IL-33. In this study, we used Il13 -/- mice to investigate whether IL-13 regulates IL-33 activity by modulating the transmembrane and soluble forms of ST2. In Il13 -/- mice, the effects of IL-33 administration were exacerbated relative to wild type (WT). Il13 -/- mice administered IL-33 i.p. had heightened splenomegaly, more immune cells in the peritoneum including an expanded ST2L+ ILC2 population, increased eosinophilia in the spleen and peritoneum, and reduced sST2 in the circulation and peritoneum. In the spleen, lung, and liver of mice given IL-33, gene expression of both isoforms of ST2 was increased in Il13 -/- mice relative to WT. We confirmed fibroblasts to be an IL-13-responsive cell type that can regulate IL-33 activity through production of sST2. This study elucidates the important regulatory activity that IL-13 exerts on IL-33 through induction of IL-33 decoy receptor sST2 and through modulation of ST2L+ ILC2s.
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Affiliation(s)
- Melvin Zhang
- Inflammation and Immunology Research Unit, Pfizer, Inc., Cambridge, MA
| | - Jennifer L Duffen
- Inflammation and Immunology Research Unit, Pfizer, Inc., Cambridge, MA
| | - Karl H Nocka
- Inflammation and Immunology Research Unit, Pfizer, Inc., Cambridge, MA
| | - Marion T Kasaian
- Inflammation and Immunology Research Unit, Pfizer, Inc., Cambridge, MA
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Transcriptome profiling reveals new insights into the roles of neuronal nitric oxide synthase on macrophage polarization towards classically activated phenotype. PLoS One 2021; 16:e0257908. [PMID: 34587205 PMCID: PMC8480887 DOI: 10.1371/journal.pone.0257908] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Accepted: 09/13/2021] [Indexed: 01/09/2023] Open
Abstract
In response to various stimuli, naïve macrophages usually polarize to M1 (classically activated) or M2 (alternatively activated) cells with distinct biological functions. Neuronal nitric oxide synthase (NOS1) is involved in M1 macrophage polarization at an early stage. Here, we show for the first time that NOS1 is dispensable for M2 macrophage polarization for the first time. Further, differentially expressed genes (DEGs) regulated by NOS1 signaling in M1-polarized macrophages stimulated with lipopolysaccharide (LPS) were characterized by transcriptome analysis of wild-type (WT) and NOS1 knockout mouse macrophages. Thousands of affected genes were detected 2 h post LPS challenge, and this wide-ranging effect became greater with a longer stimulation time (8 h post LPS). NOS1 deficiency caused dysregulated expression of hundreds of LPS-responsive genes. Most DEGs were enriched in biological processes related to transcription and regulation of the immune and inflammatory response. At 2 h post-LPS, the toll-like receptor (TLR) signaling pathway, cytokine-cytokine receptor interaction, and NOD-like receptor signaling pathway were the major pathways affected, whereas the main pathways affected at 8 h post-LPS were Th1 and Th2 cell differentiation, FoxO, and AMPK signaling pathway. Identified DEGs were validated by real-time quantitative PCR and interacted in a complicated signaling pathway network. Collectively, our data show that NOS1 is dispensable for M2 macrophage polarization and reveal novel insights in the role of NOS1 signaling at different stages of M1 macrophage polarization through distinct TLR4 plasma membrane-localized and endosome-internalized signaling pathways.
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Yu H, Yong W, Gao T, Na M, Zhang Y, Kuguminkiriza IH, Kenechukwu AA, Guo Q, Zhang G, Deng X. Hormesis of low-dose inhibition of pAkt1 (Ser473) followed by a great increase of proline-rich inositol polyphosphate 5-phosphatase (PIPP) level in oocytes. In Vitro Cell Dev Biol Anim 2021; 57:342-349. [PMID: 33537929 DOI: 10.1007/s11626-021-00546-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Accepted: 01/06/2021] [Indexed: 10/22/2022]
Abstract
Hormesis describes a biphasic dose-response relationship generally characterized by a low-dose excitement and a high-dose inhibition. This phenomenon has been observed in the regulation of cell, organ, and organismic level. However, hormesis has not reported in oocytes. In this study, we observed, for the first time, hormetic responses of PIPP levels in oocytes by inhibitor of Akt1 or PKCδ. The expression of PIPP was detected by qPCR, immunofluorescent (IF), and Western Blot (WB). To observe the changes of PIPP levels, we used the inhibitors against pAkt1 (Ser473) or PKCδ, SH-6 or sotrastaurin with low and/or high-dose, treated GV oocytes and cultured for 4 h, respectively. The results showed that PIPP expression was significantly enhanced when oocytes were treated with SH-6 or sotrastaurin 10 μM, but decreased with SH-6 or sotrastaurin 100 μM. We also examined the changes of PIPP levels when GV oocytes were treated with exogenous PtdIns(3,4,5)P3 or LY294002 for 4 h. Our results showed that PIPP level was enhanced much higher under the treatment of 0.1 μM PtdIns(3,4,5)P3 than that of 1 μM PtdIns(3,4,5)P3, which is consistent with the changes of PIPP when oocytes were treated with inhibitors of pAkt1 (Ser473) or PKCδ. In addition, with PIPP siRNA, we detected that down-regulated PIPP may affect distributions of Akt, Cdc25, and pCdc2 (Tyr15). Taken together, these results show that the relationships between PIPP and Akt may follow the principle of hormesis and play a key role during release of diplotene arrest in mouse oocytes.
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Affiliation(s)
- Hang Yu
- Department of Physics and Biophysics, School of Fundamental Sciences, China Medical University (CMU), Shenyang, 110122, People's Republic of China
| | - Wei Yong
- Center Laboratory of the Fourth Affiliated Hospital, China Medical University (CMU), Shenyang, 110032, People's Republic of China
| | - Teng Gao
- Center Laboratory of the Fourth Affiliated Hospital, China Medical University (CMU), Shenyang, 110032, People's Republic of China
| | - Man Na
- Center Laboratory of the Fourth Affiliated Hospital, China Medical University (CMU), Shenyang, 110032, People's Republic of China
| | - Ye Zhang
- Center Laboratory of the Fourth Affiliated Hospital, China Medical University (CMU), Shenyang, 110032, People's Republic of China
| | | | | | - Qingguo Guo
- Department of Biochemistry and Molecular Biology, CMU, Shenyang, China
| | - Guoli Zhang
- Institute of Veterinary Medicine, The Academy of Military Medical Sciences of PLA, Changchun, 130122, Jilin, People's Republic of China
| | - Xin Deng
- Center Laboratory of the Fourth Affiliated Hospital, China Medical University (CMU), Shenyang, 110032, People's Republic of China.
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Identification of 5-Gene Signature Improves Lung Adenocarcinoma Prognostic Stratification Based on Differential Expression Invasion Genes of Molecular Subtypes. BIOMED RESEARCH INTERNATIONAL 2020; 2020:8832739. [PMID: 33490259 PMCID: PMC7790577 DOI: 10.1155/2020/8832739] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 11/25/2020] [Accepted: 12/13/2020] [Indexed: 12/11/2022]
Abstract
Background The acquisition of invasive tumor cell behavior is considered to be the cornerstone of the metastasis cascade. Thus, genetic markers associated with invasiveness can be stratified according to patient prognosis. In this study, we aimed to identify an invasive genetic trait and study its biological relevance in lung adenocarcinoma. Methods 250 TCGA patients with lung adenocarcinoma were used as the training set, and the remaining 250 TCGA patients, 500 ALL TCGA patients, 226 patients with GSE31210, 83 patients with GSE30219, and 127 patients with GSE50081 were used as the verification data sets. Subtype classification of all TCGA lung adenocarcinoma samples was based on invasion-associated genes using the R package ConsensusClusterPlus. Kaplan-Meier curves, LASSO (least absolute contraction and selection operator) method, and univariate and multivariate Cox analysis were used to develop a molecular model for predicting survival. Results As a consequence, two molecular subtypes for LUAD were first identified from all TCGA all data sets which were significant on survival time. C1 subtype with poor prognosis has higher clinical characteristics of malignancy, higher mutation frequency of KRAS and TP53, and a lower expression of immune regulatory molecules. 2463 differentially expressed invasion genes between C1 and C2 subtypes were obtained, including 580 upregulation genes and 1883 downregulation genes. Functional enrichment analysis found that upregulated genes were associated with the development of tumor pathways, while downregulated genes were more associated with immunity. Furthermore, 5-invasion gene signature was constructed based on 2463 genes, which was validated in four data sets. This signature divided patients into high-risk and low-risk groups, and the LUDA survival rate of the high-risk group is significantly lower than that of the low-risk group. Multivariate Cox analysis revealed that this gene signature was an independent prognostic factor for LUDA. Compared with other existing models, our model has a higher AUC. Conclusion In this study, two subtypes were identified. In addition, we developed a 5-gene signature prognostic risk model, which has a good AUC in the training set and independent validation set and is a model with independent clinical characteristics. Therefore, we recommend using this classifier as a molecular diagnostic test to assess the prognostic risk of patients with LUDA.
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Csolle MP, Ooms LM, Papa A, Mitchell CA. PTEN and Other PtdIns(3,4,5)P 3 Lipid Phosphatases in Breast Cancer. Int J Mol Sci 2020; 21:ijms21239189. [PMID: 33276499 PMCID: PMC7730566 DOI: 10.3390/ijms21239189] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 11/25/2020] [Accepted: 12/01/2020] [Indexed: 12/31/2022] Open
Abstract
The phosphoinositide 3-kinase (PI3K)/AKT signalling pathway is hyperactivated in ~70% of breast cancers. Class I PI3K generates PtdIns(3,4,5)P3 at the plasma membrane in response to growth factor stimulation, leading to AKT activation to drive cell proliferation, survival and migration. PTEN negatively regulates PI3K/AKT signalling by dephosphorylating PtdIns(3,4,5)P3 to form PtdIns(4,5)P2. PtdIns(3,4,5)P3 can also be hydrolysed by the inositol polyphosphate 5-phosphatases (5-phosphatases) to produce PtdIns(3,4)P2. Interestingly, while PTEN is a bona fide tumour suppressor and is frequently mutated/lost in breast cancer, 5-phosphatases such as PIPP, SHIP2 and SYNJ2, have demonstrated more diverse roles in regulating mammary tumourigenesis. Reduced PIPP expression is associated with triple negative breast cancers and reduced relapse-free and overall survival. Although PIPP depletion enhances AKT phosphorylation and supports tumour growth, this also inhibits cell migration and metastasis in vivo, in a breast cancer oncogene-driven murine model. Paradoxically, SHIP2 and SYNJ2 are increased in primary breast tumours, which correlates with invasive disease and reduced survival. SHIP2 or SYNJ2 overexpression promotes breast tumourigenesis via AKT-dependent and independent mechanisms. This review will discuss how PTEN, PIPP, SHIP2 and SYNJ2 distinctly regulate multiple functional targets, and the mechanisms by which dysregulation of these distinct phosphoinositide phosphatases differentially affect breast cancer progression.
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Xu L, Shao Y, Ren L, Liu X, Li Y, Xu J, Ye Y. IQGAP2 Inhibits Migration and Invasion of Gastric Cancer Cells via Elevating SHIP2 Phosphatase Activity. Int J Mol Sci 2020; 21:ijms21061968. [PMID: 32183047 PMCID: PMC7139352 DOI: 10.3390/ijms21061968] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 03/09/2020] [Accepted: 03/12/2020] [Indexed: 12/30/2022] Open
Abstract
Previous studies have shown reduced expression of Src homology 2-containing inositol 5-phosphatase 2 (SHIP2) and its tumor-suppressive role in gastric cancer (GC). However, the precise role of SHIP2 in the migration and invasion of GC cells remains unclear. Here, an IQ motif containing the GTPase-activating protein 2 (IQGAP2) as a SHIP2 binding partner, was screened and identified by co-immunoprecipitation and mass spectrometry studies. While IQGAP2 ubiquitously expressed in GC cells, IQGAP2 and SHIP2 co-localized in the cytoplasm of GC cells, and this physical association was confirmed by the binding of IQGAP2 to PRD and SAM domains of SHIP2. The knockdown of either SHIP2 or IQGAP2 promoted cell migration and invasion by inhibiting SHIP2 phosphatase activity, activating Akt and subsequently increasing epithelial–mesenchymal transition (EMT). Furthermore, knockdown of IQGAP2 in SHIP2-overexpressing GC cells reversed the inhibition of cell migration and invasion by SHIP2 induction, which was associated with the suppression of elevated SHIP2 phosphatase activity. Moreover, the deletion of PRD and SAM domains of SHIP2 abrogated the interaction and restored cell migration and invasion. Collectively, these results indicate that IQGAP2 interacts with SHIP2, leading to the increment of SHIP2 phosphatase activity, and thereby inhibiting the migration and invasion of GC cells via the inactivation of Akt and reduction in EMT.
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Affiliation(s)
| | | | | | | | | | | | - Yan Ye
- Correspondence: ; Tel.: +86-551-65161139
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10
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Nakada-Tsukui K, Watanabe N, Maehama T, Nozaki T. Phosphatidylinositol Kinases and Phosphatases in Entamoeba histolytica. Front Cell Infect Microbiol 2019; 9:150. [PMID: 31245297 PMCID: PMC6563779 DOI: 10.3389/fcimb.2019.00150] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Accepted: 04/23/2019] [Indexed: 12/11/2022] Open
Abstract
Phosphatidylinositol (PtdIns) metabolism is indispensable in eukaryotes. Phosphoinositides (PIs) are phosphorylated derivatives of PtdIns and consist of seven species generated by reversible phosphorylation of the inositol moieties at the positions 3, 4, and 5. Each of the seven PIs has a unique subcellular and membrane domain distribution. In the enteric protozoan parasite Entamoeba histolytica, it has been previously shown that the PIs phosphatidylinositol 3-phosphate (PtdIns3P), PtdIns(4,5)P2, and PtdIns(3,4,5)P3 are localized to phagosomes/phagocytic cups, plasma membrane, and phagocytic cups, respectively. The localization of these PIs in E. histolytica is similar to that in mammalian cells, suggesting that PIs have orthologous functions in E. histolytica. In contrast, the conservation of the enzymes that metabolize PIs in this organism has not been well-documented. In this review, we summarized the full repertoire of the PI kinases and PI phosphatases found in E. histolytica via a genome-wide survey of the current genomic information. E. histolytica appears to have 10 PI kinases and 23 PI phosphatases. It has a panel of evolutionarily conserved enzymes that generate all the seven PI species. However, class II PI 3-kinases, type II PI 4-kinases, type III PI 5-phosphatases, and PI 4P-specific phosphatases are not present. Additionally, regulatory subunits of class I PI 3-kinases and type III PI 4-kinases have not been identified. Instead, homologs of class I PI 3-kinases and PTEN, a PI 3-phosphatase, exist as multiple isoforms, which likely reflects that elaborate signaling cascades mediated by PtdIns(3,4,5)P3 are present in this organism. There are several enzymes that have the nuclear localization signal: one phosphatidylinositol phosphate (PIP) kinase, two PI 3-phosphatases, and one PI 5-phosphatase; this suggests that PI metabolism also has conserved roles related to nuclear functions in E. histolytica, as it does in model organisms.
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Affiliation(s)
- Kumiko Nakada-Tsukui
- Department of Parasitology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Natsuki Watanabe
- Department of Parasitology, National Institute of Infectious Diseases, Tokyo, Japan.,Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Tomohiko Maehama
- Division of Molecular and Cellular Biology, Graduate School of Medicine, Kobe University, Kobe, Japan
| | - Tomoyoshi Nozaki
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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Feng L, Su J, Chi R, Zhu Q, Lv S, Liang W. Effect of amlodipine besylate combined with acupoint application of traditional Chinese medicine nursing on the treatment of renal failure and hypertension by the PI3K/AKT pathway. Int J Mol Med 2019; 43:1900-1910. [PMID: 30816438 DOI: 10.3892/ijmm.2019.4104] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Accepted: 02/08/2019] [Indexed: 11/06/2022] Open
Abstract
To study the effect and molecular mechanisms of amlodipine besylate combined with acupoint application of traditional Chinese medicine nursing on the treatment methods of renal failure and hypertension. A total of 60 cases of renal failure hypertension were randomly divided into the Control group and the Treatment group. The control group was treated with amlodipine besylate, while the treatment group was treated with amlodipine besylate combined with acupoint application of traditional Chinese medicine nursing. A rat model of renal failure hypertension was established. Rats were divided into the sham group, model group, NC group (treated with amlodipine besylate) and treatment group (treated with amlodipine besylate combined with acupoint application of traditional Chinese medicine nursing). Rats were given drugs at 10‑20 weeks of age to observe their general condition and detect changes of blood pressure, blood biochemical indices and urine index. The pathological changes of renal tissue were examined by hematoxylin and eosin staining, and the expression of vascular endothelial growth factor (VEGF) and matrix metalloproteinase (MMP)9 were detected by immunohistochemistry. Reverse transcription‑quantitative polymerase chain reaction was used to determine mRNA expression of phosphoinositide 3‑kinase (PI3K), protein kinase B (AKT) and endothelin (ET)‑1 and western blotting was used to detect the expression of phosphorylated (p)‑PI3K/PI3K, p‑AKT/AKT and p‑nuclear factor (NF)‑κB p65/NF‑κB p65 protein. Systolic and diastolic blood pressures in Treated group patients were significantly lower compared with in Control group patients. The systolic and diastolic blood pressure of rats were significantly decreased and blood urea nitrogen (BUN), carbapenem‑resistant Enterobacteriaceae (CRE), N‑acetyl‑β‑D‑glucosaminidase (NAG), urine protein (UP) and blood urea protein (BUP), contents were significantly decreased following amlodipine besylate treatment. The expression of VEGF and matrix metallopeptidase 9 protein were significantly decreased, but the expression of PI3K, AKT mRNA and p‑PI3K/PI3K, p‑AKT/AKT protein were significantly increased. ET‑1 mRNA and p‑NF‑κB p65/NF‑κB protein were significantly increased. The pathological alterations of renal tissue were improved and the pathological changes of glomerulus, tubule and interstitium were alleviated. Amlodipine besylate combined with acupoint application of traditional Chinese medicine nursing can effectively reduce the systolic pressure and diastolic pressure of patients, and improve the symptoms and signs of patients, which may be associated with the regulation of the expression of PI3K/AKT pathway, so as to regulate the expression of BUN, CRE, UP, BUP and NAG.
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Affiliation(s)
- Liping Feng
- Department of Rehabilitation, Yantai Hospital of Tradition Chinese Medicine, Yantai, Shandong 264000, P.R. China
| | - Jiahang Su
- Clinical Pharmacy Room, Yantai Hospital of Tradition Chinese Medicine, Yantai, Shandong 264000, P.R. China
| | - Rongxiang Chi
- Department of Nursing, Yantai Hospital of Tradition Chinese Medicine, Yantai, Shandong 264000, P.R. China
| | - Qiao Zhu
- Department of Cardiology, Yantai Hospital of Tradition Chinese Medicine, Yantai, Shandong 264000, P.R. China
| | - Shuguang Lv
- Department of Cardiology, Yantai Hospital of Tradition Chinese Medicine, Yantai, Shandong 264000, P.R. China
| | - Wenjing Liang
- Department of Public Health, Yantai Hospital of Tradition Chinese Medicine, Yantai, Shandong 264000, P.R. China
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12
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Ramos AR, Ghosh S, Erneux C. The impact of phosphoinositide 5-phosphatases on phosphoinositides in cell function and human disease. J Lipid Res 2018; 60:276-286. [PMID: 30194087 DOI: 10.1194/jlr.r087908] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 09/01/2018] [Indexed: 02/06/2023] Open
Abstract
Phosphoinositides (PIs) are recognized as major signaling molecules in many different functions of eukaryotic cells. PIs can be dephosphorylated by multiple phosphatase activities at the 5-, 4-, and 3- positions. Human PI 5-phosphatases belong to a family of 10 members. Except for inositol polyphosphate 5-phosphatase A, they all catalyze the dephosphorylation of PI(4,5)P2 and/or PI(3,4,5)P3 at the 5- position. PI 5-phosphatases thus directly control the levels of PI(3,4,5)P3 and participate in the fine-tuning regulatory mechanisms of PI(3,4)P2 and PI(4,5)P2 Second messenger functions have been demonstrated for PI(3,4)P2 in invadopodium maturation and lamellipodia formation. PI 5-phosphatases can use several substrates on isolated enzymes, and it has been challenging to establish their real substrate in vivo. PI(4,5)P2 has multiple functions in signaling, including interacting with scaffold proteins, ion channels, and cytoskeleton proteins. PI 5-phosphatase isoenzymes have been individually implicated in human diseases, such as the oculocerebrorenal syndrome of Lowe, through mechanisms that include lipid control. Oncogenic and tumor-suppressive functions of PI 5-phosphatases have also been reported in different cell contexts. The mechanisms responsible for genetic diseases and for oncogenic or tumor-suppressive functions are not fully understood. The regulation of PI 5-phosphatases is thus crucial in understanding cell functions.
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Affiliation(s)
- Ana Raquel Ramos
- Interdisciplinary Research Institute (IRIBHM), Université Libre de Bruxelles, 1070 Brussels, Belgium
| | - Somadri Ghosh
- Interdisciplinary Research Institute (IRIBHM), Université Libre de Bruxelles, 1070 Brussels, Belgium
| | - Christophe Erneux
- Interdisciplinary Research Institute (IRIBHM), Université Libre de Bruxelles, 1070 Brussels, Belgium
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13
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Croft A, Guo ST, Sherwin S, Farrelly M, Yan XG, Zhang XD, Jiang CC. Functional identification of a novel transcript variant of INPP4B in human colon and breast cancer cells. Biochem Biophys Res Commun 2017; 485:47-53. [DOI: 10.1016/j.bbrc.2017.02.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 02/05/2017] [Indexed: 12/01/2022]
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14
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Regulation of PI3K effector signalling in cancer by the phosphoinositide phosphatases. Biosci Rep 2017; 37:BSR20160432. [PMID: 28082369 PMCID: PMC5301276 DOI: 10.1042/bsr20160432] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 01/10/2017] [Accepted: 01/12/2017] [Indexed: 12/24/2022] Open
Abstract
Class I phosphoinositide 3-kinase (PI3K) generates phosphatidylinositol 3,4,5-trisphosphate (PtdIns(3,4,5)P3) at the plasma membrane in response to growth factors, activating a signalling cascade that regulates many cellular functions including cell growth, proliferation, survival, migration and metabolism. The PI3K pathway is commonly dysregulated in human cancer, and drives tumorigenesis by promoting aberrant cell growth and transformation. PtdIns(3,4,5)P3 facilitates the activation of many pleckstrin homology (PH) domain-containing proteins including the serine/threonine kinase AKT. There are three AKT isoforms that are frequently hyperactivated in cancer through mutation, amplification or dysregulation of upstream regulatory proteins. AKT isoforms have converging and opposing functions in tumorigenesis. PtdIns(3,4,5)P3 signalling is degraded and terminated by phosphoinositide phosphatases such as phosphatase and tensin homologue (PTEN), proline-rich inositol polyphosphate 5-phosphatase (PIPP) (INPP5J) and inositol polyphosphate 4-phosphatase type II (INPP4B). PtdIns(3,4,5)P3 is rapidly hydrolysed by PIPP to generate phosphatidylinositol 3,4-bisphosphate (PtdIns(3,4)P2), which is further hydrolysed by INPP4B to form phosphatidylinositol 3-phosphate (PtdIns3P). PtdIns(3,4)P2 and PtdIns3P are also important signalling molecules; PtdIns(3,4)P2 together with PtdIns(3,4,5)P3 are required for maximal AKT activation and PtdIns3P activates PI3K-dependent serum and glucocorticoid-regulated kinase (SGK3) signalling. Loss of Pten, Pipp or Inpp4b expression or function promotes tumour growth in murine cancer models through enhanced AKT isoform-specific signalling. INPP4B inhibits PtdIns(3,4)P2-mediated AKT activation in breast and prostate cancer; however, INPP4B expression is increased in acute myeloid leukaemia (AML), melanoma and colon cancer where it paradoxically promotes cell proliferation, transformation and/or drug resistance. This review will discuss how PTEN, PIPP and INPP4B distinctly regulate PtdIns(3,4,5)P3 signalling downstream of PI3K and how dysregulation of these phosphatases affects cancer outcomes.
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15
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Chi MN, Guo ST, Wilmott JS, Guo XY, Yan XG, Wang CY, Liu XY, Jin L, Tseng HY, Liu T, Croft A, Hondermarck H, Scolyer RA, Jiang CC, Zhang XD. INPP4B is upregulated and functions as an oncogenic driver through SGK3 in a subset of melanomas. Oncotarget 2016; 6:39891-907. [PMID: 26573229 PMCID: PMC4741868 DOI: 10.18632/oncotarget.5359] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 10/27/2015] [Indexed: 01/15/2023] Open
Abstract
Inositol polyphosphate 4-phosphatase type II (INPP4B) negatively regulates PI3K/Akt signalling and has a tumour suppressive role in some types of cancers. However, we have found that it is upregulated in a subset of melanomas. Here we report that INPP4B can function as an oncogenic driver through activation of serum- and glucocorticoid-regulated kinase 3 (SGK3) in melanoma. While INPP4B knockdown inhibited melanoma cell proliferation and retarded melanoma xenograft growth, overexpression of INPP4B enhanced melanoma cell and melanocyte proliferation and triggered anchorage-independent growth of melanocytes. Noticeably, INPP4B-mediated melanoma cell proliferation was not related to activation of Akt, but was mediated by SGK3. Upregulation of INPP4B in melanoma cells was associated with loss of miRNA (miR)-494 and/or miR-599 due to gene copy number reduction. Indeed, overexpression of miR-494 or miR-599 downregulated INPP4B, reduced SGK3 activation, and inhibited melanoma cell proliferation, whereas introduction of anti-miR-494 or anti-miR-599 upregulated INPP4B, enhanced SGK3 activation, and promoted melanoma cell proliferation. Collectively, these results identify upregulation of INPP4B as an oncogenic mechanism through activation of SGK3 in a subset of melanomas, with implications for targeting INPP4B and restoring miR-494 and miR-599 as novel approaches in the treatment of melanomas with high INPP4B expression.
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Affiliation(s)
- Meng Na Chi
- School of Medicine and Public Health, The University of Newcastle, NSW 2308, Australia
| | - Su Tang Guo
- School of Biomedical Sciences and Pharmacy, The University of Newcastle, NSW 2308, Australia.,Department of Molecular Biology, Shanxi Cancer Hospital and Institute, Affiliated Hospital of Shanxi Medical University, Taiyuan, Shanxi 030013, China
| | - James S Wilmott
- Discipline of Pathology, The University of Sydney, and Tissue Pathology and Diagnostic Oncology, Royal Prince Alfred Hospital, Sydney, NSW 2006, Australia
| | - Xiang Yun Guo
- Department of Molecular Biology, Shanxi Cancer Hospital and Institute, Affiliated Hospital of Shanxi Medical University, Taiyuan, Shanxi 030013, China
| | - Xu Guang Yan
- School of Medicine and Public Health, The University of Newcastle, NSW 2308, Australia
| | - Chun Yan Wang
- School of Biomedical Sciences and Pharmacy, The University of Newcastle, NSW 2308, Australia.,Department of Molecular Biology, Shanxi Cancer Hospital and Institute, Affiliated Hospital of Shanxi Medical University, Taiyuan, Shanxi 030013, China
| | - Xiao Ying Liu
- School of Biomedical Sciences and Pharmacy, The University of Newcastle, NSW 2308, Australia
| | - Lei Jin
- School of Medicine and Public Health, The University of Newcastle, NSW 2308, Australia
| | - Hsin-Yi Tseng
- School of Biomedical Sciences and Pharmacy, The University of Newcastle, NSW 2308, Australia
| | - Tao Liu
- Children's Cancer Institute Australia for Medical Research, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Amanda Croft
- School of Biomedical Sciences and Pharmacy, The University of Newcastle, NSW 2308, Australia
| | - Hubert Hondermarck
- School of Biomedical Sciences and Pharmacy, The University of Newcastle, NSW 2308, Australia
| | - Richard A Scolyer
- Discipline of Pathology, The University of Sydney, and Tissue Pathology and Diagnostic Oncology, Royal Prince Alfred Hospital, Sydney, NSW 2006, Australia
| | - Chen Chen Jiang
- School of Medicine and Public Health, The University of Newcastle, NSW 2308, Australia
| | - Xu Dong Zhang
- School of Medicine and Public Health, The University of Newcastle, NSW 2308, Australia.,School of Biomedical Sciences and Pharmacy, The University of Newcastle, NSW 2308, Australia
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16
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Mushtaq Z, Choudhury SD, Gangwar SK, Orso G, Kumar V. Human Senataxin Modulates Structural Plasticity of the Neuromuscular Junction in Drosophila through a Neuronally Conserved TGFβ Signalling Pathway. NEURODEGENER DIS 2016; 16:324-36. [PMID: 27197982 DOI: 10.1159/000445435] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 03/12/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Mutations in the human Senataxin (hSETX) gene have been shown to cause two forms of neurodegenerative disorders - a dominant form called amyotrophic lateral sclerosis type 4 (ALS4) and a recessive form called ataxia with oculomotor apraxia type 2 (AOA2). SETX is a putative DNA/RNA helicase involved in RNA metabolism. Although several dominant mutations linked with ALS4 have been identified in SETX, their contribution towards ALS4 pathophysiology is still elusive. METHOD In order to model ALS4 in Drosophila and to elucidate the morphological, physiological and signalling consequences, we overexpressed the wild-type and pathological forms of hSETX in Drosophila. RESULTS AND CONCLUSIONS The pan-neuronal expression of wild-type or mutant forms of hSETX induced morphological plasticity at neuromuscular junction (NMJ) synapses. Surprisingly, we found that while the NMJ synapses were increased in number, the neuronal function was normal. Analysis of signalling pathways revealed that hSETX modulates the Highwire (Hiw; a conserved neuronal E3 ubiquitin ligase)-dependent bone morphogenetic protein/TGFβ pathway. Thus, our study could pave the way for a better understanding of ALS4 progression by SETX through the regulation of neuronal E3 ubiquitin pathways.
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Affiliation(s)
- Zeeshan Mushtaq
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal, India
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17
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Hakim S, Dyson JM, Feeney SJ, Davies EM, Sriratana A, Koenig MN, Plotnikova OV, Smyth IM, Ricardo SD, Hobbs RM, Mitchell CA. Inpp5e suppresses polycystic kidney disease via inhibition of PI3K/Akt-dependent mTORC1 signaling. Hum Mol Genet 2016; 25:2295-2313. [PMID: 27056978 DOI: 10.1093/hmg/ddw097] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 03/17/2016] [Indexed: 12/20/2022] Open
Abstract
Polycystic kidney disease (PKD) is a common cause of renal failure with few effective treatments. INPP5E is an inositol polyphosphate 5-phosphatase that dephosphorylates phosphoinositide 3-kinase (PI3K)-generated PI(3,4,5)P3 and is mutated in ciliopathy syndromes. Germline Inpp5e deletion is embryonically lethal, attributed to cilia stability defects, and is associated with polycystic kidneys. However, the molecular mechanisms responsible for PKD development upon Inpp5e loss remain unknown. Here, we show conditional inactivation of Inpp5e in mouse kidney epithelium results in severe PKD and renal failure, associated with a partial reduction in cilia number and hyperactivation of PI3K/Akt and downstream mammalian target of rapamycin complex 1 (mTORC1) signaling. Treatment with an mTORC1 inhibitor improved kidney morphology and function, but did not affect cilia number or length. Therefore, we identify Inpp5e as an essential inhibitor of the PI3K/Akt/mTORC1 signaling axis in renal epithelial cells, and demonstrate a critical role for Inpp5e-dependent mTORC1 regulation in PKD suppression.
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Affiliation(s)
- Sandra Hakim
- Cancer Program, Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
| | - Jennifer M Dyson
- Cancer Program, Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
| | - Sandra J Feeney
- Cancer Program, Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
| | - Elizabeth M Davies
- Cancer Program, Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
| | - Absorn Sriratana
- Cancer Program, Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
| | - Monica N Koenig
- Cancer Program, Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
| | - Olga V Plotnikova
- Cancer Program, Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
| | - Ian M Smyth
- Cancer Program, Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia Development and Stem Cell program, Department of Anatomy and Developmental Biology, Monash University, Clayton, VIC 3800, Australia
| | - Sharon D Ricardo
- Development and Stem Cell program, Department of Anatomy and Developmental Biology, Monash University, Clayton, VIC 3800, Australia
| | - Robin M Hobbs
- Development and Stem Cell program, Department of Anatomy and Developmental Biology, Monash University, Clayton, VIC 3800, Australia Australian Regenerative Medicine Institute, Monash University, Clayton, VIC 3800, Australia
| | - Christina A Mitchell
- Cancer Program, Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
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18
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Ye Y, Ge YM, Xiao MM, Guo LM, Li Q, Hao JQ, Da J, Hu WL, Zhang XD, Xu J, Zhang LJ. Suppression of SHIP2 contributes to tumorigenesis and proliferation of gastric cancer cells via activation of Akt. J Gastroenterol 2016. [PMID: 26201869 DOI: 10.1007/s00535-015-1101-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND The Src homology 2-containing inositol 5-phosphatase 2 (SHIP2) is implicated in diabetes, arthrosclerosis, and cancer. However, the role of SHIP2 in human gastric cancer remains unclear. METHODS The expression levels of SHIP2 in gastric cancer tissues, a panel of gastric cancer cell lines, and normal gastric epithelial cells were analyzed by immunohistochemistry (IHC), Western blot, and real-time quantitative RT-PCR (qRT-PCR). Gastric cancer cells with either overexpressed SHIP2 or co-overexpressed SHIP2 and Akt were analyzed to determine cell proliferation, colony formation, apoptosis, cell migration, and invasion assays. Normal gastric epithelial cells with knockdown SHIP2 or co-knockdown SHIP2 and Akt were subjected by anchorage-independent growth assays. The effect of SHIP2 on tumor growth in vivo was detected by xenograft tumorigenesis assays. RESULTS SHIP2 was commonly downregulated in gastric cancer compared with normal gastric mucosa, and overexpression of SHIP2 inhibited cell proliferation, induced apoptosis, suppressed cell motility and invasion in gastric cancer cells in vitro, and retarded the growth of xenograft gastric tumors in vivo, while knockdown of SHIP2 in normal gastric epithelial cells promoted anchorage-independent growth. Moreover, overexpression of SHIP2 inactivated Akt, and upregulated p21, p27, and the pro-apoptotic protein Bim. Restoring Akt activation in gastric cancer cells largely blocked the inhibition of PI3K/Akt signaling by SHIP2 and reversed the inhibitory effect of SHIP2 on tumorigenesis and proliferation. CONCLUSIONS This study demonstrates, for the first time, that SHIP2 is frequently downregulated in gastric cancer, and reduced SHIP2 expression promotes tumorigenesis and proliferation of gastric cancer via activation of the PI3K/Akt signaling.
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Affiliation(s)
- Yan Ye
- Department of Immunology, Anhui Medical University, Hefei, 230032, Anhui, China
| | - Yan Mei Ge
- Department of Immunology, Anhui Medical University, Hefei, 230032, Anhui, China
| | - Miao Miao Xiao
- Department of Immunology, Anhui Medical University, Hefei, 230032, Anhui, China
| | - Li Mei Guo
- Department of Immunology, Anhui Medical University, Hefei, 230032, Anhui, China
| | - Qun Li
- Department of Immunology, Anhui Medical University, Hefei, 230032, Anhui, China
| | - Ji Qing Hao
- Department of Oncology, The First Affiliated Hospital of Anhui Medical University, Hefei, 230022, Anhui, China
| | - Jie Da
- Department of Oncology, The First Affiliated Hospital of Anhui Medical University, Hefei, 230022, Anhui, China
| | - Wang Lai Hu
- Department of Immunology, Anhui Medical University, Hefei, 230032, Anhui, China
| | - Xu Dong Zhang
- School of Medicine and Public Health, The University of Newcastle, Newcastle, NSW, 2308, Australia
| | - Jiegou Xu
- Department of Immunology, Anhui Medical University, Hefei, 230032, Anhui, China.
| | - Lin Jie Zhang
- Department of Immunology, Anhui Medical University, Hefei, 230032, Anhui, China.
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19
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Regulation of PtdIns(3,4,5)P3/Akt signalling by inositol polyphosphate 5-phosphatases. Biochem Soc Trans 2016; 44:240-52. [DOI: 10.1042/bst20150214] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The phosphoinositide 3-kinase (PI3K) generated lipid signals, PtdIns(3,4,5)P3 and PtdIns(3,4)P2, are both required for the maximal activation of the serine/threonine kinase proto-oncogene Akt. The inositol polyphosphate 5-phosphatases (5-phosphatases) hydrolyse the 5-position phosphate from the inositol head group of PtdIns(3,4,5)P3 to yield PtdIns(3,4)P2. Extensive work has revealed several 5-phosphatases inhibit PI3K-driven Akt signalling, by decreasing PtdIns(3,4,5)P3 despite increasing cellular levels of PtdIns(3,4)P2. The roles that 5-phosphatases play in suppressing cell proliferation and transformation are slow to emerge; however, the 5-phosphatase PIPP [proline-rich inositol polyphosphate 5-phosphatase; inositol polyphosphate 5-phosphatase (INPP5J)] has recently been identified as a putative tumour suppressor in melanoma and breast cancer and SHIP1 [SH2 (Src homology 2)-containing inositol phosphatase 1] inhibits haematopoietic cell proliferation. INPP5E regulates cilia stability and INPP5E mutations have been implicated ciliopathy syndromes. This review will examine 5-phosphatase regulation of PI3K/Akt signalling, focussing on the role PtdIns(3,4,5)P3 5-phosphatases play in developmental diseases and cancer.
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20
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Guo ST, Chi MN, Yang RH, Guo XY, Zan LK, Wang CY, Xi YF, Jin L, Croft A, Tseng HY, Yan XG, Farrelly M, Wang FH, Lai F, Wang JF, Li YP, Ackland S, Scott R, Agoulnik IU, Hondermarck H, Thorne RF, Liu T, Zhang XD, Jiang CC. INPP4B is an oncogenic regulator in human colon cancer. Oncogene 2015; 35:3049-61. [PMID: 26411369 PMCID: PMC4908438 DOI: 10.1038/onc.2015.361] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 07/30/2015] [Accepted: 08/24/2015] [Indexed: 12/11/2022]
Abstract
Inositol polyphosphate 4-phosphatase type II (INPP4B) negatively regulates phosphatidylinositol 3-kinase signaling and is a tumor suppressor in some types of cancers. However, we have found that it is frequently upregulated in human colon cancer cells. Here we show that silencing of INPP4B blocks activation of Akt and serum- and glucocorticoid-regulated kinase 3 (SGK3), inhibits colon cancer cell proliferation and retards colon cancer xenograft growth. Conversely, overexpression of INPP4B increases proliferation and triggers anchorage-independent growth of normal colon epithelial cells. Moreover, we demonstrate that the effect of INPP4B on Akt and SGK3 is associated with inactivation of phosphate and tensin homolog through its protein phosphatase activity and that the increase in INPP4B is due to Ets-1-mediated transcriptional upregulation in colon cancer cells. Collectively, these results suggest that INPP4B may function as an oncogenic driver in colon cancer, with potential implications for targeting INPP4B as a novel approach to treat this disease.
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Affiliation(s)
- S T Guo
- Department of Molecular Biology, Shanxi Cancer Hospital and Institute, Affiliated Hospital of Shanxi Medical University, Shanxi, China
| | - M N Chi
- School of Medicine and Public Health, University of Newcastle, Newcastle, New South Wales, Australia
| | - R H Yang
- Department of Molecular Biology, Shanxi Cancer Hospital and Institute, Affiliated Hospital of Shanxi Medical University, Shanxi, China
| | - X Y Guo
- Department of Molecular Biology, Shanxi Cancer Hospital and Institute, Affiliated Hospital of Shanxi Medical University, Shanxi, China
| | - L K Zan
- Department of Pathology, Shanxi Cancer Hospital and Institute, Shanxi, China
| | - C Y Wang
- Department of Molecular Biology, Shanxi Cancer Hospital and Institute, Affiliated Hospital of Shanxi Medical University, Shanxi, China
| | - Y F Xi
- Department of Pathology, Shanxi Cancer Hospital and Institute, Shanxi, China
| | - L Jin
- School of Medicine and Public Health, University of Newcastle, Newcastle, New South Wales, Australia
| | - A Croft
- Department of Medical Oncology, Calvary Mater Newcastle Hospital, Newcastle, New South Wales, Australia
| | - H-Y Tseng
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, New South Wales, Australia
| | - X G Yan
- School of Medicine and Public Health, University of Newcastle, Newcastle, New South Wales, Australia
| | - M Farrelly
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, New South Wales, Australia
| | - F H Wang
- Department of Molecular Biology, Shanxi Cancer Hospital and Institute, Affiliated Hospital of Shanxi Medical University, Shanxi, China
| | - F Lai
- School of Medicine and Public Health, University of Newcastle, Newcastle, New South Wales, Australia
| | - J F Wang
- Department of Pathology, Shanxi Cancer Hospital and Institute, Shanxi, China
| | - Y P Li
- Department of Colorectal Surgery, Shanxi Cancer Hospital and Institute, Shanxi, China
| | - S Ackland
- Department of Medical Oncology, Calvary Mater Newcastle Hospital, Newcastle, New South Wales, Australia
| | - R Scott
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, New South Wales, Australia
| | - I U Agoulnik
- Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Miami, FL, USA
| | - H Hondermarck
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, New South Wales, Australia
| | - R F Thorne
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, New South Wales, Australia
| | - T Liu
- Children's Cancer Institute Australia for Medical Research, University of New South Wales, Sydney, New South Wales, Australia
| | - X D Zhang
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, New South Wales, Australia
| | - C C Jiang
- School of Medicine and Public Health, University of Newcastle, Newcastle, New South Wales, Australia
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21
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Rudge SA, Wakelam MJO. Phosphatidylinositolphosphate phosphatase activities and cancer. J Lipid Res 2015; 57:176-92. [PMID: 26302980 DOI: 10.1194/jlr.r059154] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Indexed: 12/13/2022] Open
Abstract
Signaling through the phosphoinositide 3-kinase pathways mediates the actions of a plethora of hormones, growth factors, cytokines, and neurotransmitters upon their target cells following receptor occupation. Overactivation of these pathways has been implicated in a number of pathologies, in particular a range of malignancies. The tight regulation of signaling pathways necessitates the involvement of both stimulatory and terminating enzymes; inappropriate activation of a pathway can thus result from activation or inhibition of the two signaling arms. The focus of this review is to discuss, in detail, the activities of the identified families of phosphoinositide phosphatase expressed in humans, and how they regulate the levels of phosphoinositides implicated in promoting malignancy.
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Affiliation(s)
- Simon A Rudge
- Signalling Programme, Babraham Institute, Cambridge CB22 3AT, United Kingdom
| | - Michael J O Wakelam
- Signalling Programme, Babraham Institute, Cambridge CB22 3AT, United Kingdom
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22
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Zhu T, Yuan J, Wang Y, Gong C, Xie Y, Li H. MiR-661 contributed to cell proliferation of human ovarian cancer cells by repressing INPP5J expression. Biomed Pharmacother 2015; 75:123-8. [PMID: 26282217 DOI: 10.1016/j.biopha.2015.07.023] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 07/26/2015] [Indexed: 11/19/2022] Open
Abstract
Accumulating evidence has emerged important roles for microRNAs (miRNAs) participating in oncogenesis and growth of various cancers. We hypothesized that miR-661 played an important role in cell growth of ovarian cancer. Here, we found miR-661 was upregulated in human ovarian cancer cell lines and clinical tumor tissues. Our results revealed that miR-661 directly targeted INPP5J, thereby acting as tumor promoter in ovarian cancer cells by blocking cell proliferation. Importantly, we identified miR-661 as a positive regulator of INPP5J-induced AKT pathway. Taken together, our study sheds light onto the role of miR-661 as tumor promoter by targeting the INPP5J gene, and then promoting cell proliferation of ovarian cancer.
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Affiliation(s)
- Tongyu Zhu
- Department of Obstetrics and Gynecology, General Hospital of Jinan Military Command, Shandong 250031, People's Republic of China.
| | - Jing Yuan
- Department of Medical Information, General Hospital of Jinan Military Command. Shandong 250031, People's Republic of China
| | - Yuzhi Wang
- Department of Obstetrics and Gynecology, General Hospital of Jinan Military Command, Shandong 250031, People's Republic of China
| | - Cuiping Gong
- Department of Obstetrics and Gynecology, General Hospital of Jinan Military Command, Shandong 250031, People's Republic of China
| | - Yudou Xie
- Department of Obstetrics and Gynecology, General Hospital of Jinan Military Command, Shandong 250031, People's Republic of China
| | - Hong Li
- Center for Reproductive Medicine, Department of Obstetrics and Gynecology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, People's Republic of China
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23
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Ooms LM, Binge LC, Davies EM, Rahman P, Conway JRW, Gurung R, Ferguson DT, Papa A, Fedele CG, Vieusseux JL, Chai RC, Koentgen F, Price JT, Tiganis T, Timpson P, McLean CA, Mitchell CA. The Inositol Polyphosphate 5-Phosphatase PIPP Regulates AKT1-Dependent Breast Cancer Growth and Metastasis. Cancer Cell 2015; 28:155-69. [PMID: 26267533 DOI: 10.1016/j.ccell.2015.07.003] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2014] [Revised: 06/03/2015] [Accepted: 07/10/2015] [Indexed: 12/11/2022]
Abstract
Metastasis is the major cause of breast cancer mortality. Phosphoinositide 3-kinase (PI3K) generated PtdIns(3,4,5)P3 activates AKT, which promotes breast cancer cell proliferation and regulates migration. To date, none of the inositol polyphosphate 5-phosphatases that inhibit PI3K/AKT signaling have been reported as tumor suppressors in breast cancer. Here, we show depletion of the inositol polyphosphate 5-phosphatase PIPP (INPP5J) increases breast cancer cell transformation, but reduces cell migration and invasion. Pipp ablation accelerates oncogene-driven breast cancer tumor growth in vivo, but paradoxically reduces metastasis by regulating AKT1-dependent tumor cell migration. PIPP mRNA expression is reduced in human ER-negative breast cancers associated with reduced long-term outcome. Collectively, our findings identify PIPP as a suppressor of oncogenic PI3K/AKT signaling in breast cancer.
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Affiliation(s)
- Lisa M Ooms
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia
| | - Lauren C Binge
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia
| | - Elizabeth M Davies
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia
| | - Parvin Rahman
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia
| | - James R W Conway
- Garvan Institute of Medical Research, The Kinghorn Cancer Centre, Faculty of Medicine, St Vincent's Clinical School, University of NSW, Darlinghurst, NSW 2010, Australia
| | - Rajendra Gurung
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia
| | - Daniel T Ferguson
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia
| | - Antonella Papa
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia
| | - Clare G Fedele
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia
| | - Jessica L Vieusseux
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia
| | - Ryan C Chai
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia
| | | | - John T Price
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia
| | - Tony Tiganis
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia
| | - Paul Timpson
- Garvan Institute of Medical Research, The Kinghorn Cancer Centre, Faculty of Medicine, St Vincent's Clinical School, University of NSW, Darlinghurst, NSW 2010, Australia
| | - Catriona A McLean
- Department of Anatomical Pathology, Alfred Hospital, Prahran, VIC 3181, Australia
| | - Christina A Mitchell
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800, Australia.
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Hsu F, Mao Y. The structure of phosphoinositide phosphatases: Insights into substrate specificity and catalysis. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1851:698-710. [PMID: 25264170 DOI: 10.1016/j.bbalip.2014.09.015] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 09/10/2014] [Accepted: 09/17/2014] [Indexed: 12/17/2022]
Abstract
Phosphoinositides (PIs) are a group of key signaling and structural lipid molecules involved in a myriad of cellular processes. PI phosphatases, together with PI kinases, are responsible for the conversion of PIs between distinctive phosphorylation states. PI phosphatases are a large collection of enzymes that are evolved from at least two disparate ancestors. One group is distantly related to endonucleases, which apply divalent metal ions for phosphoryl transfer. The other group is related to protein tyrosine phosphatases, which contain a highly conserved active site motif Cys-X5-Arg (CX5R). In this review, we focus on structural insights to illustrate current understandings of the molecular mechanisms of each PI phosphatase family, with emphasis on their structural basis for substrate specificity determinants and catalytic mechanisms. This article is part of a Special Issue entitled Phosphoinositides.
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Affiliation(s)
- FoSheng Hsu
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Yuxin Mao
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA.
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25
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Differential SKIP expression in PTEN-deficient glioblastoma regulates cellular proliferation and migration. Oncogene 2014; 34:3711-27. [DOI: 10.1038/onc.2014.303] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 07/18/2014] [Accepted: 08/13/2014] [Indexed: 12/25/2022]
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Formoso K, Billi SC, Frasch AC, Scorticati C. Tyrosine 251 at the C-terminus of neuronal glycoprotein M6a is critical for neurite outgrowth. J Neurosci Res 2014; 93:215-29. [PMID: 25242528 DOI: 10.1002/jnr.23482] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 07/12/2014] [Accepted: 08/15/2014] [Indexed: 12/12/2022]
Abstract
Neuronal glycoprotein M6a is involved in neuronal plasticity, promoting neurite and filopodia outgrowth and, likely, synaptogenesis. Polymorphisms in the human M6a gene GPM6A have recently been associated with mental illnesses such as schizophrenia, bipolar disorders, and claustrophobia. Nevertheless, the molecular bases underlying these observations remain unknown. We have previously documented that, to induce filopodia formation, M6a depends on the association of membrane lipid microdomains and the activation of Src and mitogen-activated protein kinase kinases. Here, in silico analysis of the phosphorylation of tyrosine 251 (Y251) at the C-terminus of M6a showed that it could be a target of Src kinases. We examined whether phosphorylation of M6a at Y251 affects neurite and filopodia outgrowth and the targets involved in its signal propagation. This work provides evidence that the Src kinase family and the phosphatidylinositide 3-kinase (PI3K), but not Ras, participate in M6a signal cascade leading to neurite/filopodia outgrowth in hippocampal neurons and murine neuroblastoma N2a cells. Phosphorylation of M6a at Y251 is essential only for neurite outgrowth by the PI3K/AKT-mediated pathway and, moreover, rescues the inhibition caused by selective Src inhibitor and external M6a monoclonal antibody treatment. Thus, we suggest that phosphorylation of M6a at Y251 is critical for a specific stage of neuronal development and triggers redundant signaling pathways leading to neurite extension.
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Affiliation(s)
- Karina Formoso
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
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Abstract
The specific interaction of phosphoinositides with proteins is critical for a plethora of cellular processes, including cytoskeleton remodelling, mitogenic signalling, ion channel regulation and membrane traffic. The spatiotemporal restriction of different phosphoinositide species helps to define compartments within the cell, and this is particularly important for membrane trafficking within both the secretory and endocytic pathways. Phosphoinositide homoeostasis is tightly regulated by a large number of inositol kinases and phosphatases, which respectively phosphorylate and dephosphorylate distinct phosphoinositide species. Many of these enzymes have been implicated in regulating membrane trafficking and, accordingly, their dysregulation has been linked to a number of human diseases. In the present review, we focus on the inositol phosphatases, concentrating on their roles in membrane trafficking and the human diseases with which they have been associated.
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miR-508 sustains phosphoinositide signalling and promotes aggressive phenotype of oesophageal squamous cell carcinoma. Nat Commun 2014; 5:4620. [PMID: 25099196 DOI: 10.1038/ncomms5620] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 07/08/2014] [Indexed: 12/21/2022] Open
Abstract
The strength and duration of phosphoinositide signalling from phosphatidylinositol-3-kinase (PI3K) activation to Akt is tightly balanced by phosphoinositide kinases and phosphatases. However, how phosphatase-mediated negative regulatory effects are concomitantly disrupted in cancers, which commonly exhibit constitutively activated PI3K/Akt signalling, remains undefined. Here we report that miR-508 directly suppresses multiple phosphatases, including inositol polyphosphate-5-phosphatase J (INPP5J), phosphatase and tensin homologue (PTEN) and inositol polyphosphate 4-phosphatase type I (INPP4A), resulting in constitutive activation of PI3K/Akt signalling. Furthermore, we find that overexpressing miR-508 promotes, while silencing miR-508 impairs, the aggressive phenotype of oesophageal squamous cell carcinoma (ESCC) both in vitro and in vivo. Importantly, the level of miR-508 correlates with poor survival and activated PI3K/Akt signalling in a large cohort of ESCC specimens. These findings uncover a mechanism for constitutive PI3K/Akt activation in ESCC, and support a functionally and clinically relevant epigenetic mechanism in cancer progression.
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PI3K-GSK3 signalling regulates mammalian axon regeneration by inducing the expression of Smad1. Nat Commun 2014; 4:2690. [PMID: 24162165 PMCID: PMC3836055 DOI: 10.1038/ncomms3690] [Citation(s) in RCA: 138] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Accepted: 09/27/2013] [Indexed: 01/20/2023] Open
Abstract
In contrast to neurons in the central nervous system, mature neurons in the mammalian peripheral nervous system (PNS) can regenerate axons after injury, in part, by enhancing intrinsic growth competence. However, the signalling pathways that enhance the growth potential and induce spontaneous axon regeneration remain poorly understood. Here we reveal that phosphatidylinositol 3-kinase (PI3K) signalling is activated in response to peripheral axotomy and that PI3K pathway is required for sensory axon regeneration. Moreover, we show that glycogen synthase kinase 3 (GSK3), rather than mammalian target of rapamycin, mediates PI3K-dependent augmentation of the growth potential in the PNS. Furthermore, we show that PI3K-GSK3 signal is conveyed by the induction of a transcription factor Smad1 and that acute depletion of Smad1 in adult mice prevents axon regeneration in vivo. Together, these results suggest PI3K-GSK3-Smad1 signalling as a central module for promoting sensory axon regeneration in the mammalian nervous system.
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Loss of PI(4,5)P2 5-Phosphatase A Contributes to Resistance of Human Melanoma Cells to RAF/MEK Inhibitors. Transl Oncol 2013; 6:470-81. [PMID: 23908690 DOI: 10.1593/tlo.13277] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 05/07/2013] [Accepted: 05/09/2013] [Indexed: 11/18/2022] Open
Abstract
Past studies have shown that the inositol polyphosphate 5-phosphatase, phosphatidylinositol 4,5-bisphosphate 5-phosphatase (PIB5PA), is commonly downregulated or lost in melanomas, which contributes to elevated activation of phosphatidylinositol 3-kinase (PI3K)/Akt in melanoma cells. In this report, we provide evidence that PIB5PA deficiency plays a role in resistance of melanoma cells to RAF/mitogen-activated protein kinase kinase (MEK) inhibitors. Ectopic expression of PIB5PA enhanced apoptosis induced by the RAF inhibitor PLX4720 in BRAF(V600E) and by the MEK inhibitor U0126 in both BRAF(V600E) and wild-type BRAF melanoma cells. This was due to inhibition of PI3K/Akt, as co-introduction of an active form of Akt (myr-Akt) abolished the effect of overexpression of PIB5PA on apoptosis induced by PLX4720 or U0126. While overexpression of PIB5PA triggered activation of Bad and down-regulation of Mcl-1, knockdown of Bad or overexpression of Mcl-1 recapitulated, at least in part, the effect of myr-Akt, suggesting that regulation of Bad and Mcl-1 is involved in PIB5PA-mediated sensitization of melanoma cells to the inhibitors. The role of PIB5PA deficiency in BRAF inhibitor resistance was confirmed by knockdown of PIB5PA, which led to increased growth of BRAF(V600E) melanoma cells selected for resistance to PLX4720. Consistent with its role in vitro, overexpression of PIB5PA and the MEK inhibitor selumetinib cooperatively inhibited melanoma tumor growth in a xenograft model. Taken together, these results identify loss of PIB5PA as a novel resistance mechanism of melanoma to RAF/MEK inhibitors and suggest that restoration of PIB5PA may be a useful strategy to improve the therapeutic efficacy of the inhibitors in the treatment of melanoma.
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Abstract
Phosphoinositides (PIs) make up only a small fraction of cellular phospholipids, yet they control almost all aspects of a cell's life and death. These lipids gained tremendous research interest as plasma membrane signaling molecules when discovered in the 1970s and 1980s. Research in the last 15 years has added a wide range of biological processes regulated by PIs, turning these lipids into one of the most universal signaling entities in eukaryotic cells. PIs control organelle biology by regulating vesicular trafficking, but they also modulate lipid distribution and metabolism via their close relationship with lipid transfer proteins. PIs regulate ion channels, pumps, and transporters and control both endocytic and exocytic processes. The nuclear phosphoinositides have grown from being an epiphenomenon to a research area of its own. As expected from such pleiotropic regulators, derangements of phosphoinositide metabolism are responsible for a number of human diseases ranging from rare genetic disorders to the most common ones such as cancer, obesity, and diabetes. Moreover, it is increasingly evident that a number of infectious agents hijack the PI regulatory systems of host cells for their intracellular movements, replication, and assembly. As a result, PI converting enzymes began to be noticed by pharmaceutical companies as potential therapeutic targets. This review is an attempt to give an overview of this enormous research field focusing on major developments in diverse areas of basic science linked to cellular physiology and disease.
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Affiliation(s)
- Tamas Balla
- Section on Molecular Signal Transduction, Program for Developmental Neuroscience, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA.
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Ye Y, Jin L, Wilmott JS, Hu WL, Yosufi B, Thorne RF, Liu T, Rizos H, Yan XG, Dong L, Tay KH, Tseng HY, Guo ST, de Bock CE, Jiang CC, Wang CY, Wu M, Zhang LJ, Hersey P, Scolyer RA, Zhang XD. PI(4,5)P2 5-phosphatase A regulates PI3K/Akt signalling and has a tumour suppressive role in human melanoma. Nat Commun 2013; 4:1508. [PMID: 23443536 PMCID: PMC3586716 DOI: 10.1038/ncomms2489] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Accepted: 01/14/2013] [Indexed: 11/26/2022] Open
Abstract
Inositol polyphosphate 5-phosphatases can terminate downstream signalling of phosphatidylinositol-3 kinase; however, their biological role in the pathogenesis of cancer is controversial. Here we report that the inositol polyphosphate 5-phosphatase, phosphatidylinositol 4,5-bisphosphate 5-phosphatase, has a tumour suppressive role in melanoma. Although it is commonly downregulated in melanoma, overexpression of phosphatidylinositol 4,5-bisphosphate 5-phosphatase blocks Akt activation, inhibits proliferation and undermines survival of melanoma cells in vitro, and retards melanoma growth in a xenograft model. In contrast, knockdown of phosphatidylinositol 4,5-bisphosphate 5-phosphatase results in increased proliferation and anchorage-independent growth of melanocytes. Although DNA copy number loss is responsible for downregulation of phosphatidylinositol 4,5-bisphosphate 5-phosphatase in a proportion of melanomas, histone hypoacetylation mediated by histone deacetylases HDAC2 and HDAC3 through binding to the transcription factor Sp1 at the PIB5PA gene promoter appears to be another commonly involved mechanism. Collectively, these results establish the tumour suppressive role of phosphatidylinositol 4,5-bisphosphate 5-phosphatase and reveal mechanisms involved in its downregulation in melanoma. Inositol polyphosphate 5-phosphatases, such as PIB5PA, terminate signalling downstream of phosophoinositide-3 kinase; however, their biological roles remain unclear. Here the authors report that PIB5PA has a tumour suppressive role in melanoma.
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Affiliation(s)
- Yan Ye
- School of Medicine and Public Health, University of Newcastle, Newcastle, New South Wales 2308, Australia
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Abstract
Phosphoinositide signalling molecules interact with a plethora of effector proteins to regulate cell proliferation and survival, vesicular trafficking, metabolism, actin dynamics and many other cellular functions. The generation of specific phosphoinositide species is achieved by the activity of phosphoinositide kinases and phosphatases, which phosphorylate and dephosphorylate, respectively, the inositol headgroup of phosphoinositide molecules. The phosphoinositide phosphatases can be classified as 3-, 4- and 5-phosphatases based on their specificity for dephosphorylating phosphates from specific positions on the inositol head group. The SAC phosphatases show less specificity for the position of the phosphate on the inositol ring. The phosphoinositide phosphatases regulate PI3K/Akt signalling, insulin signalling, endocytosis, vesicle trafficking, cell migration, proliferation and apoptosis. Mouse knockout models of several of the phosphoinositide phosphatases have revealed significant physiological roles for these enzymes, including the regulation of embryonic development, fertility, neurological function, the immune system and insulin sensitivity. Importantly, several phosphoinositide phosphatases have been directly associated with a range of human diseases. Genetic mutations in the 5-phosphatase INPP5E are causative of the ciliopathy syndromes Joubert and MORM, and mutations in the 5-phosphatase OCRL result in Lowe's syndrome and Dent 2 disease. Additionally, polymorphisms in the 5-phosphatase SHIP2 confer diabetes susceptibility in specific populations, whereas reduced protein expression of SHIP1 is reported in several human leukaemias. The 4-phosphatase, INPP4B, has recently been identified as a tumour suppressor in human breast and prostate cancer. Mutations in one SAC phosphatase, SAC3/FIG4, results in the degenerative neuropathy, Charcot-Marie-Tooth disease. Indeed, an understanding of the precise functions of phosphoinositide phosphatases is not only important in the context of normal human physiology, but to reveal the mechanisms by which these enzyme families are implicated in an increasing repertoire of human diseases.
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Phosphatidylinositol 4-phosphate 5-kinase α negatively regulates nerve growth factor-induced neurite outgrowth in PC12 cells. Exp Mol Med 2013; 45:e16. [PMID: 23538529 PMCID: PMC3641393 DOI: 10.1038/emm.2013.18] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Neurite outgrowth, a cell differentiation process involving membrane morphological changes, is critical for neuronal network and development. The membrane lipid, phosphatidylinositol (PI) 4,5-bisphosphate (PIP2), is a key regulator of many important cell surface events of membrane signaling, trafficking and dynamics. This lipid is produced mainly by the type I PI 4-phosphate 5-kinase (PIP5K) family members. In this study, we addressed whether PIP5Kα, an isoform of PIP5K, could have a role in neurite outgrowth induced by nerve growth factor (NGF). For this purpose, we knocked down PIP5Kα in PC12 rat pheochromocytoma cells by stable expression of PIP5Kα microRNA that significantly reduced PIP5Kα expression and PIP2 level. Interestingly, NGF-induced neurite outgrowth was more prominent in PIP5Kα-knockdown (KD) cells than in control cells. Conversely, add-back of PIP5Kα into PIP5Kα KD cells abrogated the effect of NGF on neurite outgrowth. NGF treatment activated PI 3-kinase (PI3K)/Akt pathway, which seemed to be associated with reactive oxygen species generation. Similar to the changes in neurite outgrowth, the PI3K/Akt activation by NGF was potentiated by PIP5Kα KD, but was attenuated by the reintroduction of PIP5Kα. Moreover, exogenously applied PIP2 to PIP5Kα KD cells also suppressed Akt activation by NGF. Together, our results suggest that PIP5Kα acts as a negative regulator of NGF-induced neurite outgrowth by inhibiting PI3K/Akt signaling pathway in PC12 cells.
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Park JH, Lee SB, Lee KH, Ahn JY. Nuclear Akt promotes neurite outgrowth in the early stage of neuritogenesis. BMB Rep 2013; 45:521-5. [PMID: 23010173 DOI: 10.5483/bmbrep.2012.45.9.114] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In addition to its pivotal role in neuronal survival, PI3K/Akt signaling is integral to neuronal differentiation and neurite outgrowth. However, the exact role of Akt in neuronal differentiation is still controversial. Here, we found that nuclear expression of CA-Akt resulted in unusual rapid neurite outgrowth and overexpression of KD-Akt caused multiple dendrite growth without specific axon elongation. Moreover, microarray data revealed that the expression of FOXQ1 expression was about 10-fold higher in cells with nuclear, active Akt than in control cells. Quantitative real-time PCR analysis showed that mRNA levels were upregulated in NLS-CA-Akt cells as compared to KD or EV cells. Furthermore, our FACS analysis demonstrated that overexpression of NLS-CA-Akt accumulate cells in the G1 phase within 24 h, fitting with the rapid sprouting of neuritis. Thus, our data implied that at least in this early time frame, the overexpression of nuclear, active Akt forced cells into neurite development through probably FOXQ1regulation.
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Affiliation(s)
- Ji Hye Park
- Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746, Korea
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Atorvastatin enhances neurite outgrowth in cortical neurons in vitro via up-regulating the Akt/mTOR and Akt/GSK-3β signaling pathways. Acta Pharmacol Sin 2012; 33:861-72. [PMID: 22705730 DOI: 10.1038/aps.2012.59] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
AIM To investigate whether atorvastatin can promote formation of neurites in cultured cortical neurons and the signaling mechanisms responsible for this effect. METHODS Cultured rat cerebral cortical neurons were incubated with atorvastatin (0.05-10 μmol/L) for various lengths of time. For pharmacological experiments, inhibitors were added 30 min prior to addition of atorvastatin. Control cultures received a similar amount of DMSO. Following the treatment period, phase-contrast digital images were taken. Digital images of neurons were analyzed for total neurite branch length (TNBL), neurite number, terminal branch number, and soma area by SPOT Advanced Imaging software. After incubation with atorvastatin for 48 h, the levels of phosphorylated 3-phosphoinoside-dependent protein kinase-1 (PDK1), phospho-Akt, phosphorylated mammalian target of rapamycin (mTOR), phosphorylated 4E-binding protein 1 (4E-BP1), p70S6 kinase (p70S6K), and glycogen synthase kinase-3β (GSK-3β) in the cortical neurons were evaluated using Western blotting analyses. RESULTS Atorvastatin (0.05-10 μmol/L) resulted in dose-dependent increase in neurite number and length in these neurons. Pretreatment of the cortical neurons with phosphatidylinositol 3-kinase (PI3K) inhibitors LY294002 (30 μmol/L) and wortmannin (5 μmol/L), Akt inhibitor tricribine (1 μmol/L) or mTOR inhibitor rapamycin (100 nmol/L) blocked the atorvastatin-induced increase in neurite outgrowth, suggesting that atorvastatin promoted neurite outgrowth via activating the PI3K/Akt/mTOR signaling pathway. Atorvastatin (10 μmol/L) significantly increased the levels of phosphorylated PDK1, Akt and mTOR in the cortical neurons, which were prevented by LY294002 (30 μmol/L). Moreover, atorvastatin (10 μmol/L) stimulated the phosphorylation of 4E-BP1 and p70S6K, the substrates of mTOR, in the cortical neurons. In addition, atorvastatin (10 μmol/L) significantly increased the phosphorylated GSK-3β level in the cortical neurons, which was prevented by both LY294002 and tricribine. CONCLUSION These results suggest that activation of both the PI3K/Akt/mTOR and Akt/GSK-3β signaling pathways is responsible for the atorvastatin-induced neurite outgrowth in cultured cortical neurons.
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Dyson JM, Fedele CG, Davies EM, Becanovic J, Mitchell CA. Phosphoinositide phosphatases: just as important as the kinases. Subcell Biochem 2012; 58:215-279. [PMID: 22403078 DOI: 10.1007/978-94-007-3012-0_7] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Phosphoinositide phosphatases comprise several large enzyme families with over 35 mammalian enzymes identified to date that degrade many phosphoinositide signals. Growth factor or insulin stimulation activates the phosphoinositide 3-kinase that phosphorylates phosphatidylinositol (4,5)-bisphosphate [PtdIns(4,5)P(2)] to form phosphatidylinositol (3,4,5)-trisphosphate [PtdIns(3,4,5)P(3)], which is rapidly dephosphorylated either by PTEN (phosphatase and tensin homologue deleted on chromosome 10) to PtdIns(4,5)P(2), or by the 5-phosphatases (inositol polyphosphate 5-phosphatases), generating PtdIns(3,4)P(2). 5-phosphatases also hydrolyze PtdIns(4,5)P(2) forming PtdIns(4)P. Ten mammalian 5-phosphatases have been identified, which regulate hematopoietic cell proliferation, synaptic vesicle recycling, insulin signaling, and embryonic development. Two 5-phosphatase genes, OCRL and INPP5E are mutated in Lowe and Joubert syndrome respectively. SHIP [SH2 (Src homology 2)-domain inositol phosphatase] 2, and SKIP (skeletal muscle- and kidney-enriched inositol phosphatase) negatively regulate insulin signaling and glucose homeostasis. SHIP2 polymorphisms are associated with a predisposition to insulin resistance. SHIP1 controls hematopoietic cell proliferation and is mutated in some leukemias. The inositol polyphosphate 4-phosphatases, INPP4A and INPP4B degrade PtdIns(3,4)P(2) to PtdIns(3)P and regulate neuroexcitatory cell death, or act as a tumor suppressor in breast cancer respectively. The Sac phosphatases degrade multiple phosphoinositides, such as PtdIns(3)P, PtdIns(4)P, PtdIns(5)P and PtdIns(3,5)P(2) to form PtdIns. Mutation in the Sac phosphatase gene, FIG4, leads to a degenerative neuropathy. Therefore the phosphatases, like the lipid kinases, play major roles in regulating cellular functions and their mutation or altered expression leads to many human diseases.
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Affiliation(s)
- Jennifer M Dyson
- Department of Biochemistry and Molecular Biology, Monash University, Wellington Rd, 3800, Clayton, Australia
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Abstract
PIKfyve, a phosphoinositide 5-kinase synthesizing PtdIns(3,5)P₂ and PtdIns5P in a cellular context, belongs to an evolutionarily ancient gene family of PtdIns(3,5)P₂-synthesizing enzymes that, except for plants, are products of a single-copy gene across species. In the dozen years after its discovery, enormous progress has been made in characterizing the numerous PIKfyve cellular functions and the regulatory mechanisms that govern these functions. It became clear that PIKfyve does not act alone but, rather, it engages the scaffolding regulator ArPIKfyve and the phosphatase Sac3 to make a multiprotein "PAS" complex, so called for the first letters of the protein names. This complex relays antagonistic signals, one for synthesis, another for turnover of PtdIns(3,5)P₂, whose dysregulated coordination is linked to several human diseases. The physiological significance for each protein in the PAS complex is underscored by the early lethality of the mouse models with disruption in any of the three genes. This chapter summarizes our current knowledge of the diverse and complex functionality of PIKfyve and PtdIns(3,5)P₂/PtdIns5P products with particular highlights on recent discoveries of inherited or somatic mutations in PIKfyve and Sac3 linked to human disorders.
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Affiliation(s)
- Assia Shisheva
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.
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Deng X, Feng C, Wang EH, Zhu YQ, Cui C, Zong ZH, Li GS, Liu C, Meng J, Yu BZ. Influence of proline-rich inositol polyphosphate 5-phosphatase, on early development of fertilized mouse eggs, via inhibition of phosphorylation of Akt. Cell Prolif 2011; 44:156-65. [PMID: 21401757 DOI: 10.1111/j.1365-2184.2011.00743.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVES Proline-rich inositol polyphosphate 5-phosphatase (PIPP) is one of the signal-modifying enzymes that play pivotal regulatory roles in PI3K signalling pathway. The aim of this study was to determine the role of PIPP in early development of fertilized mouse eggs, via inhibition of Akt activity and subsequent downstream signalling events. MATERIALS AND METHODS The mRNA transcript levels of endogenous PIPP and Akt1, Akt2, Akt3 were detected in G(1) , S, G(2) and M phases of fertilized mouse eggs by RT-PCR. Levels of exogenous PIPP, phosphorylated Akt at Ser473, dephosphorylated cdc2 at Tyr15 and levels of CCNB1, were detected respectively by immunoblotting. Changes in Akt localization were observed by fluoroimmunoassay; meanwhile, changes in activity of Akt and its downstream MPF were detected. Percentages of cells undergoing division were determined by counting, using a dissecting microscope. RESULTS PIPP and Akt1 transcripts were detectable in G(1), S, G(2) and M phases of fertilized mouse eggs, but Akt2 and Akt3 were not. We also observed that overexpression of PIPP in fertilized eggs decreased expression of phosphorylated Akt at Ser473 and altered membrane localization of phosphorylated Akt at Ser473 specifically. Furthermore, overexpression of PIPP resulted in decreases in mitosis-phase promoting factor activity, level of dephosphorylated cdc2 at Tyr15 and cleavage rate of fertilized mouse eggs. CONCLUSIONS Our data suggest, for the first time, that PIPP may affect development of fertilized mouse eggs by inhibition of level of phosphorylated Akt at Ser473 and subsequent inhibition of downstream signal cascades.
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Affiliation(s)
- X Deng
- Experimental Center of the Functional Subjects, Institute of Pathology and Pathophysiology, China Medical University, Shenyang, Liaoning, China
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Vantaggiato C, Bondioni S, Airoldi G, Bozzato A, Borsani G, Rugarli EI, Bresolin N, Clementi E, Bassi MT. Senataxin modulates neurite growth through fibroblast growth factor 8 signalling. ACTA ACUST UNITED AC 2011; 134:1808-28. [PMID: 21576111 DOI: 10.1093/brain/awr084] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Senataxin is encoded by the SETX gene and is mainly involved in two different neurodegenerative diseases, the dominant juvenile form of amyotrophic lateral sclerosis type 4 and a recessive form of ataxia with oculomotor apraxia type 2. Based on protein homology, senataxin is predicted to be a putative DNA/RNA helicase, while senataxin interactors from patients' lymphoblast cell lines suggest a possible involvement of the protein in different aspects of RNA metabolism. Except for an increased sensitivity to oxidative DNA damaging agents shown by some ataxia with neuropathy patients' cell lines, no data are available about possible functional consequences of dominant SETX mutations and no studies address the function of senataxin in neurons. To start elucidating the physiological role of senataxin in neurons and how disease-causing mutations in this protein lead to neurodegeneration, we analysed the effect of senataxin on neuronal differentiation in primary hippocampal neurons and retinoic acid-treated P19 cells by modulating the expression levels of wild-type senataxin and three different dominant mutant forms of the protein. Wild-type senataxin overexpression was required and sufficient to trigger neuritogenesis and protect cells from apoptosis during differentiation. These actions were reversed by silencing of senataxin. In contrast, overexpression of the dominant mutant forms did not affect the regular differentiation process in primary hippocampal neurons. Analysis of the cellular pathways leading to neuritogenesis and cytoprotection revealed a role of senataxin in modulating the expression levels and signalling activity of fibroblast growth factor 8. Silencing of senataxin reduced, while overexpression enhanced, fibroblast growth factor 8 expression levels and the phosphorylation of related target kinases and effector proteins. The effects of senataxin overexpression were prevented when fibroblast growth factor 8 signalling was inhibited, while exogenous fibroblast growth factor 8 reversed the effects of senataxin silencing. Overall, these results reveal a key role of senataxin in neuronal differentiation through the fibroblast growth factor 8 signalling and provide initial molecular bases to explain the neurodegeneration associated with loss-of-function mutations in senataxin found in recessive ataxia. The lack of effect on neuritogenesis observed with the overexpression of the dominant mutant forms of senataxin apparently excludes a dominant negative effect of these mutants while favouring haploinsufficiency as the pathogenic mechanism implicated in the amyotrophic lateral sclerosis 4-related degenerative condition. Alternatively, a different protein function, other than the one involved in neuritogenesis, may be implicated in these dominant degenerative processes.
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Affiliation(s)
- Chiara Vantaggiato
- E. Medea Scientific Institute, Laboratory of Molecular Biology, Via D. L. Monza 20, 23842 Bosisio Parini, Lecco, Italy
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Astle MV, Ooms LM, Cole AR, Binge LC, Dyson JM, Layton MJ, Petratos S, Sutherland C, Mitchell CA. Identification of a proline-rich inositol polyphosphate 5-phosphatase (PIPP)•collapsin response mediator protein 2 (CRMP2) complex that regulates neurite elongation. J Biol Chem 2011; 286:23407-18. [PMID: 21550974 DOI: 10.1074/jbc.m110.214247] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Neuron polarization is essential for the formation of one axon and multiple dendrites, establishing the neuronal circuitry. Phosphoinositide 3-kinase (PI3K) signaling promotes axon selection and elongation. Here we report in hippocampal neurons siRNA knockdown of the proline-rich inositol polyphosphate 5-phosphatase (PIPP), which degrades PI3K-generated PtdIns(3,4,5)P(3), results in multiple hyperelongated axons consistent with a polarization defect. We identify collapsin response mediator protein 2 (CRMP2), which regulates axon selection by promoting WAVE1 delivery via Kinesin-1 motors to the axon growth cone, as a PIPP-interacting protein by Y2H screening, direct binding studies, and coimmunoprecipitation of an endogenous PIPP, CRMP2, and Kinesin-1 complex from brain lysates. The C-terminal growth cone-targeting domain of PIPP facilitates its interaction with CRMP2. PIPP growth cone localization is CRMP2-dependent. PIPP knockdown in PC12 cells promotes neurite elongation, WAVE1 and Kinesin-1 growth cone localization, whereas knockdown of CRMP2 exhibits the opposite phenotype, with shorter neurites and decreased WAVE1/Kinesin-1 at the growth cone. In contrast, CRMP2 overexpression promotes neurite elongation, a phenotype rescued by full-length PIPP, or expression of the CRMP2-binding PIPP domain. Therefore this study identifies PIPP and CRMP2 exert opposing roles in promoting axon selection and neurite elongation and the complex between these proteins serves to regulate the localization of effectors that promote neurite extension.
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Affiliation(s)
- Megan V Astle
- Department of Biochemistry and Molecular Biology, Monash University, Clayton 3800, Australia
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Thirunavukkarasusx N, Ghosal KJ, Kukreja R, Zhou Y, Dombkowski A, Cai S, Singh BR. Microarray analysis of differentially regulated genes in human neuronal and epithelial cell lines upon exposure to type A botulinum neurotoxin. Biochem Biophys Res Commun 2011; 405:684-90. [PMID: 21291863 DOI: 10.1016/j.bbrc.2011.01.102] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Accepted: 01/27/2011] [Indexed: 11/16/2022]
Abstract
Among the seven serotypes (A-G), type A botulinum neurotoxin (BoNT/A) is the most prevalent etiologic agent and the most potent serotype to cause foodborne botulism, characterized by flaccid muscle paralysis. Upon ingestion, BoNT/A crosses epithelial cell barriers to reach lymphatic and circulatory systems and blocks acetylcholine release at the pre-synaptic cholinergic nerve terminals of neuromuscular junctions (NMJs) resulting in paralysis. One of the unique features of BoNT/A intoxication is its neuroparalytic longevity due to its persistent catalytic activity. The persistent presence of the toxin inside the cell can induce host cell responses. To understand the pathophysiology and host response at the cellular level, gene expression changes upon exposure of human HT-29 colon carcinoma (epithelial) and SH-SY5Y neuroblastoma cell lines to BoNT/A complex were investigated using microarray analysis. In HT-29 cells, 167 genes were up-regulated while 60 genes were down-regulated, whereas in SH-SY5Y cells about 223 genes were up-regulated and 18 genes were down-regulated. Modulation of genes and pathways involved in neuroinflammatory, ubiquitin-proteasome degradation, phosphatidylinositol, calcium signaling in SH-SY5Y cells, and genes relevant to focal adhesion, cell adhesion molecules, adherens and gap junction related pathways in HT-29 cells suggest a massive host response to BoNT/A. A clear differential response in epithelial and neuronal cells indicates that the genes affected may play a distinct role in BoNTs cellular mode of action, involving these two types of host cells.
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Affiliation(s)
- Nagarajan Thirunavukkarasusx
- Department of Chemistry and Biochemistry, University of Massachusetts Dartmouth, Botulinum Research Center, 285 Old Westport Road, N Dartmouth, MA 02747, United States
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Abstract
There are numerous studies that suggest multiple links between the cellular phosphoinositide system and cancer. As key roles in cancer have been established for PI3K and PTEN - enzymes that regulate the levels of phosphatidylinositol-3,4,5-trisphosphate - compounds targeting this pathway are entering the clinic at a rapid pace. Several other phosphoinositide-modifying enzymes, including phosphoinositide kinases, phosphatases and phospholipase C enzymes, have been implicated in the generation and progression of tumours. Studies of these enzymes are providing new insights into the mechanisms and the extent of their involvement in cancer, highlighting new potential targets for therapeutic intervention.
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Affiliation(s)
- Tom D Bunney
- The Institute of Cancer Research, Section for Cell and Molecular Biology, Chester Beatty Laboratories, Fulham Road, London SW3 6JB, UK
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44
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Read DE, Gorman AM. Involvement of Akt in neurite outgrowth. Cell Mol Life Sci 2009; 66:2975-84. [PMID: 19504044 PMCID: PMC11115732 DOI: 10.1007/s00018-009-0057-8] [Citation(s) in RCA: 155] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2009] [Revised: 05/19/2009] [Accepted: 05/20/2009] [Indexed: 02/06/2023]
Abstract
The regulation of neuronal differentiation and neurite outgrowth is essential during development of the nervous system and is crucial in developing therapies to promote axon regeneration after nerve injury or in neurodegenerative diseases. The serine/threonine kinase Akt has been well documented to promote neuronal survival. More recently Akt has also been revealed as key mediator of several aspects of neurite outgrowth, including elongation, branching and calibre. Downstream of Akt, several substrates have been identified that are likely to play key roles in Akt-mediated neurite outgrowth, such as glycogen synthase kinase 3beta, peripherin, mammalian target of rapamycin and delta-catenin. The physical interaction between Akt and Hsp27, another protein that has been linked with neurite outgrowth, may also be significant in the process of neurite outgrowth. This review will unite and discuss the research to date that has examined the functionality of Akt in neuronal differentiation during development and neurite outgrowth.
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Affiliation(s)
- Danielle E. Read
- Cell Death and Survival Group, Department of Biochemistry, School of Natural Sciences, National University of Ireland, Galway, Ireland
- National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland
| | - Adrienne M. Gorman
- Cell Death and Survival Group, Department of Biochemistry, School of Natural Sciences, National University of Ireland, Galway, Ireland
- National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland
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Denley A, Gymnopoulos M, Kang S, Mitchell C, Vogt PK. Requirement of phosphatidylinositol(3,4,5)trisphosphate in phosphatidylinositol 3-kinase-induced oncogenic transformation. Mol Cancer Res 2009; 7:1132-8. [PMID: 19584261 DOI: 10.1158/1541-7786.mcr-09-0068] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Phosphatidylinositol 3-kinases (PI3K) are divided into three classes, which differ in their substrates and products. Class I generates the inositol phospholipids PI(3)P, PI(3,4)P2, and PI(3,4,5)P3 referred as PIP, PIP2, and PIP3, respectively. Class II produces PIP and PIP2, and class III generates only PIP. Substrate and product differences of the three classes are determined by the activation loops of their catalytic domains. Substitution of the class I activation loop with either class II or III activation loop results in a corresponding change of substrate preference and product restriction. We have evaluated such activation loop substitutions to show that oncogenic activity of class I PI3K is linked to the ability to produce PIP3. We further show that reduction of cellular PIP3 levels by the 5'-phosphatase PIPP interferes with PI3K-induced oncogenic transformation. PIPP also attenuates signaling through Akt and target of rapamycin. Class III PI3K fails to induce oncogenic transformation. Likewise, a constitutively membrane-bound class I PI3K mutant retaining only the protein kinase is unable to induce transformation. We conclude that PIP3 is an essential component of PI3K-mediated oncogenesis and that inability to generate PIP3 abolishes oncogenic potential.
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Affiliation(s)
- Adam Denley
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
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Sasaki T, Takasuga S, Sasaki J, Kofuji S, Eguchi S, Yamazaki M, Suzuki A. Mammalian phosphoinositide kinases and phosphatases. Prog Lipid Res 2009; 48:307-43. [PMID: 19580826 DOI: 10.1016/j.plipres.2009.06.001] [Citation(s) in RCA: 190] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Phosphoinositides are lipids that are present in the cytoplasmic leaflet of a cell's plasma and internal membranes and play pivotal roles in the regulation of a wide variety of cellular processes. Phosphoinositides are molecularly diverse due to variable phosphorylation of the hydroxyl groups of their inositol rings. The rapid and reversible configuration of the seven known phosphoinositide species is controlled by a battery of phosphoinositide kinases and phosphoinositide phosphatases, which are thus critical for phosphoinositide isomer-specific localization and functions. Significantly, a given phosphoinositide generated by different isozymes of these phosphoinositide kinases and phosphatases can have different biological effects. In mammals, close to 50 genes encode the phosphoinositide kinases and phosphoinositide phosphatases that regulate phosphoinositide metabolism and thus allow cells to respond rapidly and effectively to ever-changing environmental cues. Understanding the distinct and overlapping functions of these phosphoinositide-metabolizing enzymes is important for our knowledge of both normal human physiology and the growing list of human diseases whose etiologies involve these proteins. This review summarizes the structural and biological properties of all the known mammalian phosphoinositide kinases and phosphoinositide phosphatases, as well as their associations with human disorders.
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Affiliation(s)
- Takehiko Sasaki
- Department of Pathology and Immunology, Akita University, Graduate School of Medicine, Akita 010-8543, Japan.
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The role of the inositol polyphosphate 5-phosphatases in cellular function and human disease. Biochem J 2009; 419:29-49. [PMID: 19272022 DOI: 10.1042/bj20081673] [Citation(s) in RCA: 177] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Phosphoinositides are membrane-bound signalling molecules that regulate cell proliferation and survival, cytoskeletal reorganization and vesicular trafficking by recruiting effector proteins to cellular membranes. Growth factor or insulin stimulation induces a canonical cascade resulting in the transient phosphorylation of PtdIns(4,5)P(2) by PI3K (phosphoinositide 3-kinase) to form PtdIns(3,4,5)P(3), which is rapidly dephosphorylated either by PTEN (phosphatase and tensin homologue deleted on chromosome 10) back to PtdIns(4,5)P(2), or by the 5-ptases (inositol polyphosphate 5-phosphatases), generating PtdIns(3,4)P(2). The 5-ptases also hydrolyse PtdIns(4,5)P(2), forming PtdIns4P. Ten mammalian 5-ptases have been identified, which share a catalytic mechanism similar to that of the apurinic/apyrimidinic endonucleases. Gene-targeted deletion of 5-ptases in mice has revealed that these enzymes regulate haemopoietic cell proliferation, synaptic vesicle recycling, insulin signalling, endocytosis, vesicular trafficking and actin polymerization. Several studies have revealed that the molecular basis of Lowe's syndrome is due to mutations in the 5-ptase OCRL (oculocerebrorenal syndrome of Lowe). Futhermore, the 5-ptases SHIP [SH2 (Src homology 2)-domain-containing inositol phosphatase] 2, SKIP (skeletal muscle- and kidney-enriched inositol phosphatase) and 72-5ptase (72 kDa 5-ptase)/Type IV/Inpp5e (inositol polyphosphate 5-phosphatase E) are implicated in negatively regulating insulin signalling and glucose homoeostasis in specific tissues. SHIP2 polymorphisms are associated with a predisposition to insulin resistance. Gene profiling studies have identified changes in the expression of various 5-ptases in specific cancers. In addition, 5-ptases such as SHIP1, SHIP2 and 72-5ptase/Type IV/Inpp5e regulate macrophage phagocytosis, and SHIP1 also controls haemopoietic cell proliferation. Therefore the 5-ptases are a significant family of signal-modulating enzymes that govern a plethora of cellular functions by regulating the levels of specific phosphoinositides. Emerging studies have implicated their loss or gain of function in human disease.
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Ooms LM, Dyson JM, Kong AM, Mitchell CA. Analysis of phosphatidylinositol 3,4,5 trisphosphate 5-phosphatase activity by in vitro and in vivo assays. Methods Mol Biol 2009; 462:223-239. [PMID: 19160673 DOI: 10.1007/978-1-60327-115-8_15] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Phosphatidylinositol 3,4,5 trisphosphate [PtdIns(3,4,5)P3] is a potent membrane-bound signaling molecule transiently synthesized by phosphoinositide 3-kinase (PI3-kinase) in response to extracellular agonists. PtdIns(3,4,5)P3 signals need to be strictly controlled. PtdIns(3,4,5)P3 recruits and binds effectors that function in oncogenic signaling pathways. PtdIns(3,4,5)P3 activates cell proliferation, growth, and migration as well as regulating insulin signaling. The inositol polyphosphate 5-phosphatase family of enzymes dephosphorylate and thereby modulate PtdIns(3,4,5)P3 levels, attenuating PI3-kinase-dependent signaling. PtdIns(3,4,5)P3 5-phosphatase enzyme activity can be assessed in vitro by analysis of the hydrolysis of radiolabeled or fluorescently labeled PtdIns(3,4,5)P3 and in vivo by visualization of the recruitment and turnover of the PtdIns(3,4,5)P3-specific biosensor GFP-PH/ ARNO or other PtdIns(3,4,5)P3 binding proteins at the plasma membrane.
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Affiliation(s)
- Lisa M Ooms
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
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Tengholm A, Idevall-Hagren O. Spatio-temporal dynamics of phosphatidylinositol-3,4,5-trisphosphate signalling. VITAMINS AND HORMONES 2009; 80:287-311. [PMID: 19251042 DOI: 10.1016/s0083-6729(08)00611-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Many effects of insulin, insulin-like growth factors and other receptor stimuli are mediated via the phospholipid second messenger phosphatidylinositol-3,4,5-trisphosphate (PIP(3)). PIP(3) is formed by the activity of phosphoinositide 3-kinases in the plasma membrane, where it serves to recruit signalling proteins. These proteins coordinate complex events leading to changes in cell metabolism, growth, movement and survival. Over the past decade, new techniques for measurements of PIP(3) in the plasma membrane of individual living cells have markedly improved our understanding of the role of this messenger in a variety of cellular processes. This review summarises the mechanisms involved in formation and degradation of PIP(3) in insulin-responsive cells, how PIP(3) can be measured in individual cells as well as accumulating evidence that the plasma membrane PIP(3) concentration undergoes complex spatio-temporal patterns in many types of cells, with particular emphasis on autocrine insulin-induced PIP(3) oscillations in pancreatic beta-cells.
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Affiliation(s)
- Anders Tengholm
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Uppsala, Sweden
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Orlova I, Silver L, Gallo G. Regulation of actomyosin contractility by PI3K in sensory axons. Dev Neurobiol 2008; 67:1843-51. [PMID: 17701990 DOI: 10.1002/dneu.20558] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Phosphatidylinositol 3-kinase (PI3K) activity is known to be required for the extension of embryonic sensory axons. Inhibition of PI3K has also been shown to mediate axon retraction and growth cone collapse in response to semaphorin 3A. However, the effects of inhibiting PI3K on the neuronal cytoskeleton are not well characterized. We have previously reported that semaphorin 3A-induced axon retraction involves activation of myosin II, the formation of an intra-axonal F-actin bundle cytoskeleton, and blocks the formation of F-actin patches that serve as precursors to filopodial formation in axons. We now report that inhibition of PI3K results in activation of myosin II in axons. Inhibition of myosin II activity, or its upstream regulatory kinase RhoA-kinase, blocked axon retraction induced by inhibition of PI3K. In addition, inhibition of PI3K also induced intra-axonal F-actin bundles, which likely serve as a substratum for myosin II-based force generation during axon retraction. In axons, filopodia are formed from axonal F-actin patch precursors. Analysis of axonal F-actin patch formation in eYFP-actin expressing neurons revealed that inhibition of PI3K blocked formation of axonal F-actin patches, and thus filopodial formation. These data provide insights into the regulation of the neuronal cytoskeleton by PI3K and are consistent with the notion that decreased levels of PI3K activity mediate axon retraction and growth cone collapse in response to semaphorin 3A.
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Affiliation(s)
- Irina Orlova
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA
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