99901
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Chou CH, Loh JK, Yang MC, Lin CC, Hong MC, Cho CL, Chou AK, Wang CH, Lieu AS, Howng SL, Hsu CM, Hong YR. AIBp regulates mitotic entry and mitotic spindle assembly by controlling activation of both Aurora-A and Plk1. Cell Cycle 2015; 14:2764-76. [PMID: 26114227 PMCID: PMC4614063 DOI: 10.1080/15384101.2015.1066536] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 06/16/2015] [Accepted: 06/23/2015] [Indexed: 10/23/2022] Open
Abstract
We previously reported that Aurora-A and the hNinein binding protein AIBp facilitate centrosomal structure maintenance and contribute to spindle formation. Here, we report that AIBp also interacts with Plk1, raising the possibility of functional similarity to Bora, which subsequently promotes Aurora-A-mediated Plk1 activation at Thr210 as well as Aurora-A activation at Thr288. In kinase assays, AIBp acts not only as a substrate but also as a positive regulator of both Aurora-A and Plk1. However, AIBp functions as a negative regulator to block phosphorylation of hNinein mediated by Aurora-A and Plk1. These findings suggest a novel AIBp-dependent regulatory machinery that controls mitotic entry. Additionally, knockdown of hNinein caused failure of AIBp to target the centrosome, whereas depletion of AIBp did not affect the localization of hNinein and microtubule nucleation. Notably, knockdown of AIBp in HeLa cells impaired both Aurora-A and Plk1 kinase, resulting in phenotypes with multiple spindle pole formation and chromosome misalignment. Our data show that depletion of AIBp results in the mis-localization of TACC3 and ch-TOG, but not CEP192 and CEP215, suggesting that loss of AIBp dominantly affects the Aurora-A substrate to cause mitotic aberrations. Collectively, our data demonstrate that AIBp contributes to mitotic entry and bipolar spindle assembly and may partially control localization, phosphorylation, and activation of both Aurora-A and Plk1 via hNinein during mitotic progression.
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Affiliation(s)
- Chia-Hua Chou
- Department of Biochemistry; Faculty of Medicine; College of Medicine; Kaohsiung Medical University; Kaohsiung, Taiwan
- Department of Biological Sciences; National Sun Yat-Sen University; Kaohsiung, Taiwan
| | - Joon-Khim Loh
- Department of Surgery; Kaohsiung Municipal Hsiao-Kang Hospital; Kaohsiung Medical University; Kaohsiung, Taiwan
- Graduate Institute of Medicine; Kaohsiung Medical University; Kaohsiung, Taiwan
- Department of Neurosurgery; Kaohsiung Medical University Hospital; Kaohsiung, Taiwan
| | - Ming-Chang Yang
- Department of Biological Sciences; National Sun Yat-Sen University; Kaohsiung, Taiwan
- Laboratory of Medical Research; Center of Education and Faculty Development; Kaohsiung Armed Forces General Hospital; Kaohsiung, Taiwan
| | - Ching-Chih Lin
- Department of Biochemistry; Faculty of Medicine; College of Medicine; Kaohsiung Medical University; Kaohsiung, Taiwan
| | - Ming-Chang Hong
- Department of Biochemistry; Faculty of Medicine; College of Medicine; Kaohsiung Medical University; Kaohsiung, Taiwan
| | - Chung-Lung Cho
- Department of Biological Sciences; National Sun Yat-Sen University; Kaohsiung, Taiwan
| | - An-Kuo Chou
- Department of Anesthesiology; Kaohsiung Chang Gung Memorial Hospital and College of Medicine; Chang Gung University; Kaohsiung, Taiwan
| | - Chi-Huei Wang
- Department of Biotechnology; Kaohsiung Medical University; Kaohsiung, Taiwan
| | - Ann-Shung Lieu
- Graduate Institute of Medicine; Kaohsiung Medical University; Kaohsiung, Taiwan
- Department of Neurosurgery; Kaohsiung Medical University Hospital; Kaohsiung, Taiwan
| | - Shen-Long Howng
- Graduate Institute of Medicine; Kaohsiung Medical University; Kaohsiung, Taiwan
- Department of Neurosurgery; Kaohsiung Medical University Hospital; Kaohsiung, Taiwan
| | - Ching-Mei Hsu
- Department of Biological Sciences; National Sun Yat-Sen University; Kaohsiung, Taiwan
| | - Yi-Ren Hong
- Department of Biochemistry; Faculty of Medicine; College of Medicine; Kaohsiung Medical University; Kaohsiung, Taiwan
- Department of Biological Sciences; National Sun Yat-Sen University; Kaohsiung, Taiwan
- Graduate Institute of Medicine; Kaohsiung Medical University; Kaohsiung, Taiwan
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99902
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Johnson WC, Ordway AJ, Watada M, Pruitt JN, Williams TM, Rebeiz M. Genetic Changes to a Transcriptional Silencer Element Confers Phenotypic Diversity within and between Drosophila Species. PLoS Genet 2015; 11:e1005279. [PMID: 26115430 PMCID: PMC4483262 DOI: 10.1371/journal.pgen.1005279] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 05/13/2015] [Indexed: 11/23/2022] Open
Abstract
The modification of transcriptional regulation has become increasingly appreciated as a major contributor to morphological evolution. However, the role of negative-acting control elements (e.g. silencers) in generating morphological diversity has been generally overlooked relative to positive-acting “enhancer” elements. The highly variable body coloration patterns among Drosophilid insects represents a powerful model system in which the molecular alterations that underlie phenotypic diversity can be defined. In a survey of pigment phenotypes among geographically disparate Japanese populations of Drosophila auraria, we discovered a remarkable degree of variation in male-specific abdominal coloration. In testing the expression patterns of the major pigment-producing enzymes, we found that phenotypes uniquely correlated with differences in the expression of ebony, a gene required for yellow-colored cuticle. Assays of ebony’s transcriptional control region indicated that a lightly pigmented strain harbored cis-regulatory mutations that caused correlated changes in its expression. Through a series of chimeric reporter constructs between light and dark strain alleles, we localized function-altering mutations to a conserved silencer that mediates a male-specific pattern of ebony repression. This suggests that the light allele was derived through the loss of this silencer’s activity. Furthermore, examination of the ebony gene of D. serrata, a close relative of D. auraria which secondarily lost male-specific pigmentation revealed the parallel loss of this silencer element. These results demonstrate how loss-of-function mutations in a silencer element resulted in increased gene expression. We propose that the mutational inactivation of silencer elements may represent a favored path to evolve gene expression, impacting morphological traits. One of the greatest challenges in understanding the relationship between genotype and phenotype is to discern how changes in DNA affect the normal functioning of genes. Mutations may generate a new function for a gene, yet it is frequently observed that they inactivate some aspect of a gene’s normal capacity. Investigations focused on understanding the developmental basis for the evolution of anatomical structures has found a prevalent role for mutations that alter developmental gene regulation. In animals, genes are transcriptionally activated in specific tissues during development by regulatory sequences distributed across their expansive non-protein coding regions. Regulatory elements known as silencers act to prevent genes from being expressed in certain tissues, providing a mechanism for precise control. Here, we show how a silencer that prevents expression of a pigment-producing enzyme in certain Drosophila species has repeatedly been subject to inactivating mutations that increased this gene’s expression. This example illustrates how such negative-acting regulatory sequences can represent a convenient target for increasing gene expression through the loss of a genetic element.
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Affiliation(s)
- Winslow C. Johnson
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Alison J. Ordway
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Masayoshi Watada
- Department of Biology, Faculty of Science, Ehime University, Matsuyama, Japan
| | - Jonathan N. Pruitt
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Thomas M. Williams
- Department of Biology, University of Dayton, Dayton, Ohio, United States of America
| | - Mark Rebeiz
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
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99903
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Abstract
The nucleus is physically distinct from the cytoplasm in ways that suggest new ideas and approaches for interrogating the operation of this organelle. Chemical bond formation and breakage underlie the lives of cells, but as this special issue of Molecular Biology of the Cell attests, the nonchemical aspects of cell nuclei present a new frontier to biologists and biophysicists.
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Affiliation(s)
- Thoru Pederson
- Program in Cell and Developmental Dynamics, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605
| | - John F Marko
- Department of Molecular Biosciences and Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208
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99904
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Lieberthal TJ, Cohen HC, Kao WJ. Poly(ethylene glycol)-containing hydrogels modulate α-defensin release from polymorphonuclear leukocytes and monocyte recruitment. J Biomed Mater Res A 2015; 103:3772-80. [DOI: 10.1002/jbm.a.35519] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 05/20/2015] [Accepted: 06/04/2015] [Indexed: 01/13/2023]
Affiliation(s)
- Tyler Jacob Lieberthal
- Department of Biomedical Engineering; University of Wisconsin-Madison; 1550 Engineering Drive Madison Wisconsin 53706
| | - Hannah Caitlin Cohen
- Pharmaceutical Sciences Division, School of Pharmacy; University of Wisconsin-Madison; 777 Highland Avenue Madison Wisconsin 53705
| | - W. John Kao
- Department of Biomedical Engineering; University of Wisconsin-Madison; 1550 Engineering Drive Madison Wisconsin 53706
- Pharmaceutical Sciences Division, School of Pharmacy; University of Wisconsin-Madison; 777 Highland Avenue Madison Wisconsin 53705
- Department of Surgery, School of Medicine and Public Health; University of Wisconsin-Madison; 600 Highland Avenue Madison Wisconsin 53792
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99905
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Barse L, Bocchetta M. Non-small-cell lung carcinoma: role of the Notch signaling pathway. LUNG CANCER (AUCKLAND, N.Z.) 2015; 6:43-53. [PMID: 28210150 PMCID: PMC5217522 DOI: 10.2147/lctt.s60329] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Notch signaling plays a pivotal role during embryogenesis. It regulates three fundamental processes: lateral inhibition, boundary formation, and lineage specification. During post-natal life, Notch receptors and ligands control critical cell fate decisions both in compartments that are undergoing differentiation and in pluripotent progenitor cells. First recognized as a potent oncogene in certain lymphoblastic leukemias and mesothelium-derived tissue, the role of Notch signaling in epithelial, solid tumors has been far more controversial. The overall consequence of Notch signaling and which form of the Notch receptor drives malignancy in humans is deeply debated. Most likely, this is due to the high degree of context-dependent effects of Notch signaling. More recently, it has been discovered that Notch (especially Notch-1) can exert different, even opposite effects in the same tissue under differing microenvironmental conditions. Further complicating the understanding of Notch receptors is the recently discovered role for non-canonical Notch signaling. Additionally, the most frequent Notch signaling antagonists used in biological systems have been inhibitors of the transmembrane protease complex γ-secretase, which itself processes a plethora of class one transmembrane proteins and thus cannot be considered a Notch-specific upstream regulator. Here we review the available empirical evidence gathered in recent years concerning Notch receptors and ligands in non-small-cell lung carcinoma (NSCLC). Although an overview of the field reveals seemingly contradicting results, we propose that Notch signaling can be exploited as a therapeutic target in NSCLC and represents a promising complement to the current arsenal utilized to combat this malignancy, particularly in targeting NSCLC tissues under specific environmental conditions, such as hypoxia.
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Affiliation(s)
- Levi Barse
- Department of Pathology, Oncology Institute, Loyola University Chicago, Maywood, IL, USA
| | - Maurizio Bocchetta
- Department of Pathology, Oncology Institute, Loyola University Chicago, Maywood, IL, USA
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99906
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Zhu SJ, Hallows SE, Currie KW, Xu C, Pearson BJ. A mex3 homolog is required for differentiation during planarian stem cell lineage development. eLife 2015; 4. [PMID: 26114597 PMCID: PMC4507787 DOI: 10.7554/elife.07025] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Accepted: 06/25/2015] [Indexed: 12/30/2022] Open
Abstract
Neoblasts are adult stem cells (ASCs) in planarians that sustain cell replacement during homeostasis and regeneration of any missing tissue. While numerous studies have examined genes underlying neoblast pluripotency, molecular pathways driving postmitotic fates remain poorly defined. In this study, we used transcriptional profiling of irradiation-sensitive and irradiation-insensitive cell populations and RNA interference (RNAi) functional screening to uncover markers and regulators of postmitotic progeny. We identified 32 new markers distinguishing two main epithelial progenitor populations and a planarian homolog to the MEX3 RNA-binding protein (Smed-mex3-1) as a key regulator of lineage progression. mex3-1 was required for generating differentiated cells of multiple lineages, while restricting the size of the stem cell compartment. We also demonstrated the utility of using mex3-1(RNAi) animals to identify additional progenitor markers. These results identified mex3-1 as a cell fate regulator, broadly required for differentiation, and suggest that mex3-1 helps to mediate the balance between ASC self-renewal and commitment. DOI:http://dx.doi.org/10.7554/eLife.07025.001 Adult tissues constantly replace the millions of cells they lose on a daily basis. This is made possible by adult stem cells. But how is a stable population of stem cells maintained throughout the life of the organism with constant cell division? One way this can be accomplished is if at every stem cell division, only one of the daughter cells remains a stem cell, while the other becomes specialized. For humans, if this balance is disturbed, cancers may result from too many stem cells, and early aging may result from too few stem cells. A freshwater flatworm called Schmidtea mediterranea is known for its ability to regenerate nearly every part of its body after injury. This flatworm possesses stem cells called neoblasts that can form all of the flatworm's different cell types both during regeneration and during normal tissue turnover. Evidence suggests that the number of neoblasts and the number of specialized cells that neoblasts produce are finely balanced, similar to adult human tissues. However, little is known about the mechanism that controls whether a neoblast takes on a more specialized form. To express a gene, it must first be copied or ‘transcribed’ into an RNA molecule. Identifying the RNA molecules that are enriched in the non-stem cells that develop from neoblasts could therefore indicate which genes regulate the cell specialization process. These RNA molecules could also be used as markers that identify which cells have taken on a more specialized form. Using techniques called transcriptional profiling and RNA interference, Zhu et al. identified 32 new markers that indicate that the neoblasts have started to specialize into epithelial cells: cells that line the surfaces of many structures in the body. Further investigation revealed that one gene, called mex3-1, is needed for many specialized cell types—not just epithelial cells—to mature from neoblasts in the flatworms. In doing so, mex3-1 also limits the size of the stem cell population. Equivalents of mex3-1 are found in many different species including humans, and so Zhu et al.'s results may help us to understand how other animals regenerate and control the size of their stem cell populations. Mutant flatworms that cannot express mex3-1 could also be used to study other genes that help neoblasts to specialize. DOI:http://dx.doi.org/10.7554/eLife.07025.002
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Affiliation(s)
- Shu Jun Zhu
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, Canada
| | - Stephanie E Hallows
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, Canada
| | - Ko W Currie
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, Canada
| | - ChangJiang Xu
- Terrence Donnelly Centre for Cellular and Biomedical Research, Toronto, Canada
| | - Bret J Pearson
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, Canada
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99907
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PAQR3 modulates H3K4 trimethylation by spatial modulation of the regulatory subunits of COMPASS-like complexes in mammalian cells. Biochem J 2015; 467:415-24. [PMID: 25706881 DOI: 10.1042/bj20141392] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Histone modification plays important roles in many biological processes such as development and carcinogenesis. Methylation of histone H3 lysine 4 (H3K4) is commonly associated with transcriptional activation of genes. H3K4 methylation in mammalian cells is carried out by COMPASS (complex of proteins associated with Set1)-like complexes that are composed of catalytic subunits such as MLL1 (mixed-lineage leukaemia 1) and multiple regulatory subunits in which WDR5 (WD40 repeat-containing protein 5), RBBP5 (retinoblastoma-binding protein 5), ASH2 (absent, small or homoeotic discs 2) and DPY30 [constituting the WRAD sub-complex (WDR5-ASH2-RBBP5-DPY30 complex)] are the major ones shared from yeast to metazoans. We report, in the present paper, a new mode of spatial regulation of H3K4 methyltransferase complexes. PAQR3 (progestin and adipoQ receptors member 3), a tumour suppressor specifically localized in the Golgi apparatus, negatively regulates H3K4 trimethylation (H3K4me3) in mammalian cells. Consistently, HOXC8 and HOXA9 gene expression was negatively regulated by PAQR3 expression levels. Hypoxia-induced H3K4me3 was augmented by PAQR3 knockdown and suppressed by PAQR3 overexpression in AGS gastric cancer cells. PAQR3 was able to interact directly or indirectly with the four members of the WRAD sub-complex and tether them to the Golgi apparatus, accompanied by reduction in histone methyltransferase activity in the nucleus. PAQR3 also interfered with the interaction of WDR5 with the C-terminus of MLL1 (C-ter). Collectively, our study indicates that PAQR3 negatively modulates H3K4 methylation via altering the subcellular compartmentalization of the core regulatory subunits of the COMPASS-like complexes in mammalian cells.
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99908
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Fan P, Cunliffe HE, Maximov PY, Agboke FA, McDaniel RE, Zou X, Ramos P, Russell ML, Jordan VC. Integration of Downstream Signals of Insulin-like Growth Factor-1 Receptor by Endoplasmic Reticulum Stress for Estrogen-Induced Growth or Apoptosis in Breast Cancer Cells. Mol Cancer Res 2015; 13:1367-76. [PMID: 26116171 DOI: 10.1158/1541-7786.mcr-14-0494] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 06/12/2015] [Indexed: 12/18/2022]
Abstract
UNLABELLED Estrogen (E2) exerts a dual function on E2-deprived breast cancer cells, with both initial proliferation and subsequent induction of stress responses to cause apoptosis. However, the mechanism by which E2 integrally regulates cell growth or apoptosis-associated pathways remains to be elucidated. Here, E2 deprivation results in many alterations in stress-responsive pathways. For instance, E2-deprived breast cancer cells had higher basal levels of stress-activated protein kinase, c-Jun N-terminal kinase (JNK), compared with wild-type MCF-7 cells. E2 treatment further constitutively activated JNK after 24 hours. However, inhibition of JNK (SP600125) was unable to abolish E2- induced apoptosis, whereas SP600125 alone arrested cells at the G2 phase of the cell cycle and increased apoptosis. Further examination showed that inhibition of JNK increased gene expression of TNFα and did not effectively attenuate expression of apoptosis-related genes induced by E2. A notable finding was that E2 regulated both JNK and Akt as the downstream signals of insulin-like growth factor-1 receptor (IGFIR)/PI3K, but with distinctive modulation patterns: JNK was constitutively activated, whereas Akt and Akt-associated proteins, such as PTEN and mTOR, were selectively degraded. Endoplasmic reticulum-associated degradation (ERAD) was involved in the selective protein degradation. These findings highlight a novel IGFIR/PI3K/JNK axis that plays a proliferative role during the prelude to E2-induced apoptosis and that the endoplasmic reticulum is a key regulatory site to decide cell fate after E2 treatment. IMPLICATIONS This study provides a new rationale for further exploration of E2-induced apoptosis to improve clinical benefit.
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Affiliation(s)
- Ping Fan
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia. Department of Breast Medical Oncology, MD Anderson Cancer Center, Houston, Texas
| | - Heather E Cunliffe
- Department of Pathology, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Philipp Y Maximov
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia. Department of Breast Medical Oncology, MD Anderson Cancer Center, Houston, Texas
| | - Fadeke A Agboke
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia
| | - Russell E McDaniel
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia
| | - Xiaojun Zou
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia
| | - Pilar Ramos
- Computational Biology Division, The Translational Genomics Research Institute, Phoenix, Arizona
| | - Megan L Russell
- Computational Biology Division, The Translational Genomics Research Institute, Phoenix, Arizona
| | - V Craig Jordan
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia. Department of Breast Medical Oncology, MD Anderson Cancer Center, Houston, Texas.
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99909
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Gao FJ, Hebbar S, Gao XA, Alexander M, Pandey JP, Walla MD, Cotham WE, King SJ, Smith DS. GSK-3β Phosphorylation of Cytoplasmic Dynein Reduces Ndel1 Binding to Intermediate Chains and Alters Dynein Motility. Traffic 2015; 16:941-61. [PMID: 26010407 PMCID: PMC4543430 DOI: 10.1111/tra.12304] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Revised: 05/18/2015] [Accepted: 05/19/2015] [Indexed: 12/17/2022]
Abstract
Glycogen synthase kinase 3 (GSK‐3) has been linked to regulation of kinesin‐dependent axonal transport in squid and flies, and to indirect regulation of cytoplasmic dynein. We have now found evidence for direct regulation of dynein by mammalian GSK‐3β in both neurons and non‐neuronal cells. GSK‐3β coprecipitates with and phosphorylates mammalian dynein. Phosphorylation of dynein intermediate chain (IC) reduces its interaction with Ndel1, a protein that contributes to dynein force generation. Two conserved residues, S87/T88 in IC‐1B and S88/T89 in IC‐2C, have been identified as GSK‐3 targets by both mass spectrometry and site‐directed mutagenesis. These sites are within an Ndel1‐binding domain, and mutation of both sites alters the interaction of IC's with Ndel1. Dynein motility is stimulated by (i) pharmacological and genetic inhibition of GSK‐3β, (ii) an insulin‐sensitizing agent (rosiglitazone) and (iii) manipulating an insulin response pathway that leads to GSK‐3β inactivation. Thus, our study connects a well‐characterized insulin‐signaling pathway directly to dynein stimulation via GSK‐3 inhibition.
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Affiliation(s)
- Feng J Gao
- Department of Biological Sciences, University of South Carolina, Columbia, SC, 29208, USA
| | - Sachin Hebbar
- Bioinformatics Group, Immune Tolerance Network, Bethesda, MD, 20814, USA
| | - Xu A Gao
- Department of Biological Sciences, University of South Carolina, Columbia, SC, 29208, USA
| | - Michael Alexander
- Department of Biological Sciences, University of South Carolina, Columbia, SC, 29208, USA
| | - Jai P Pandey
- Whitehead Institute for Biomedical Research, Massachusetts Institute of Technology, Cambridge, MA, 02142, USA
| | - Michael D Walla
- Mass Spectrometry Center, Department of Chemistry & Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | - William E Cotham
- Mass Spectrometry Center, Department of Chemistry & Biochemistry, University of South Carolina, Columbia, SC, 29208, USA
| | - Stephen J King
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, 32828, USA
| | - Deanna S Smith
- Department of Biological Sciences, University of South Carolina, Columbia, SC, 29208, USA
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99910
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Petrulea MS, Plantinga TS, Smit JW, Georgescu CE, Netea-Maier RT. PI3K/Akt/mTOR: A promising therapeutic target for non-medullary thyroid carcinoma. Cancer Treat Rev 2015; 41:707-13. [PMID: 26138515 DOI: 10.1016/j.ctrv.2015.06.005] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 06/15/2015] [Accepted: 06/21/2015] [Indexed: 10/23/2022]
Abstract
Thyroid carcinoma (TC) is the most common endocrine malignancy. The pathogenesis of TC is complex and involves multiple genetic events that lead to activation of oncogenic pathways such as the MAP kinase (MAPK) pathway and the PI3K/Akt/mTOR pathway. The PI3K/Akt pathway has emerged as an important player in the pathogenesis of TC, particularly in follicular and advanced anaplastic or poorly differentiated TC. Because these patients have a poor prognosis, particularly when their tumors become resistant to the conventional treatment with radioactive iodine, efforts have been made to identify possible targets for therapy within these pathways. Orally available drugs targeting the PI3K/Akt/mTOR pathway are being used with success in treatment of several types of malignant tumors. There is an increasing amount of preclinical and clinical data supporting that this pathway may represent a promising target for systemic therapy in TC. The present review focuses on the most recent developments on the role of the PI3K/Akt pathway in the pathogenesis of non-medullary TC and will provide insight into how this pathway can be targeted either alone or in the context of multimodal therapeutic strategies for treatment of advanced TC.
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Affiliation(s)
- Mirela S Petrulea
- Department of Endocrinology, University of Medicine and Pharmacy Cluj-Napoca Iuliu Hatieganu, 3-5 Louis Pasteur, 400349 Cluj-Napoca, Romania
| | - Theo S Plantinga
- Department of Internal Medicine, Radboud University Medical Center, Geert Grooteplein Zuid 8, 6525 GA Nijmegen, The Netherlands; Division of Endocrinology, Radboud University Medical Center, Geert Grooteplein Zuid 8, 6525 GA Nijmegen, The Netherlands
| | - Jan W Smit
- Department of Internal Medicine, Radboud University Medical Center, Geert Grooteplein Zuid 8, 6525 GA Nijmegen, The Netherlands; Division of Endocrinology, Radboud University Medical Center, Geert Grooteplein Zuid 8, 6525 GA Nijmegen, The Netherlands
| | - Carmen E Georgescu
- Department of Endocrinology, University of Medicine and Pharmacy Cluj-Napoca Iuliu Hatieganu, 3-5 Louis Pasteur, 400349 Cluj-Napoca, Romania
| | - Romana T Netea-Maier
- Department of Internal Medicine, Radboud University Medical Center, Geert Grooteplein Zuid 8, 6525 GA Nijmegen, The Netherlands; Division of Endocrinology, Radboud University Medical Center, Geert Grooteplein Zuid 8, 6525 GA Nijmegen, The Netherlands..
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99911
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Yue Y, Wu S, Li Z, Li J, Li X, Xiang J, Ding H. Wild jujube polysaccharides protect against experimental inflammatory bowel disease by enabling enhanced intestinal barrier function. Food Funct 2015; 6:2568-77. [PMID: 26114600 DOI: 10.1039/c5fo00378d] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Dietary polysaccharides provide various beneficial effects for our health. We investigated the protective effects of wild jujube (Ziziphus jujuba Mill. var. spinosa (Bunge) Hu ex H. F. Chou) sarcocarp polysaccharides (WJPs) against experimental inflammatory bowel disease (IBD) by enabling enhanced intestinal barrier function. Colitis was induced in rats by the intrarectal administration of TNBS. We found that WJPs markedly ameliorated the colitis severity, including less weight loss, decreased disease activity index scores, and improved mucosal damage in colitis rats. Moreover, WJPs suppressed the inflammatory response via attenuation of TNF-α, IL-1β, IL-6 and MPO activity in colitis rats. And then, to determine the effect of WJPs on the intestinal barrier, we measured the effect of WJPs on the transepithelial electrical resistance (TER) and FITC-conjugated dextran permeability in Caco-2 cell stimulation with TNF-α. We further demonstrated that the alleviation of WJPs to colon injury was associated with barrier function by assembly of tight junction proteins. Moreover, the effect of WJPs on TER was eliminated by the specific inhibitor of AMPK. AMPK activity was also up-regulated by WJPs in Caco-2 cell stimulation with TNF-α and in colitis rats. This study demonstrates that WJPs protect against IBD by enabling enhanced intestinal barrier function involving the activation of AMPK.
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Affiliation(s)
- Yuan Yue
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, Wuhan University School of Pharmaceutical Sciences, Wuhan University, Wuhan, China.
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99912
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Todd L, Fischer AJ. Hedgehog signaling stimulates the formation of proliferating Müller glia-derived progenitor cells in the chick retina. Development 2015; 142:2610-22. [PMID: 26116667 DOI: 10.1242/dev.121616] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Accepted: 06/15/2015] [Indexed: 12/29/2022]
Abstract
Müller glia can be stimulated to de-differentiate and become proliferating progenitor cells that regenerate neurons in the retina. The signaling pathways that regulate the formation of proliferating Müller glia-derived progenitor cells (MGPCs) are beginning to be revealed. The purpose of this study was to investigate whether Hedgehog (Hh) signaling influences the formation of MGPCs in the chick retina. We find that Hh signaling is increased in damaged retinas where MGPCs are known to form. Sonic Hedgehog (Shh) is normally present in the axons of ganglion cells, but becomes associated with Müller glia and MGPCs following retinal damage. Activation of Hh signaling with recombinant human SHH (rhShh) or smoothened agonist (SAG) increased levels of Ptch1, Gli1, Gli2, Gli3, Hes1 and Hes5, and stimulated the formation of proliferating MGPCs in damaged retinas. In undamaged retinas, SAG or rhShh had no apparent effect upon the Müller glia. However, SAG combined with FGF2 potentiated the formation of MGPCs, whereas SAG combined with IGF1 stimulated the nuclear migration of Müller glia, but not the formation of MGPCs. Conversely, inhibition of Hh signaling with KAAD-cyclopamine, Gli antagonists or antibody to Shh reduced numbers of proliferating MGPCs in damaged and FGF2-treated retinas. Hh signaling potentiates Pax6, Klf4 and cFos expression in Müller glia during the formation of MGPCs. We find that FGF2/MAPK signaling recruits Hh signaling into the signaling network that drives the formation of proliferating MGPCs. Our findings implicate Hh signaling as a key component of the network of signaling pathways that promote the de-differentiation of Müller glia and proliferation of MGPCs.
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Affiliation(s)
- Levi Todd
- Department of Neuroscience, College of Medicine, The Ohio State University, 4190 Graves Hall, 333 West 10th Ave, Columbus, OH 43210, USA
| | - Andy J Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, 4190 Graves Hall, 333 West 10th Ave, Columbus, OH 43210, USA
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99913
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Boschi F, Rizzatti V, Zamboni M, Sbarbati A. Models of lipid droplets growth and fission in adipocyte cells. Exp Cell Res 2015; 336:253-62. [PMID: 26121906 DOI: 10.1016/j.yexcr.2015.06.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 05/15/2015] [Accepted: 06/03/2015] [Indexed: 01/14/2023]
Abstract
Lipid droplets (LD) are spherical cellular inclusion devoted to lipids storage. It is well known that excessive accumulation of lipids leads to several human worldwide diseases like obesity, type 2 diabetes, hepatic steatosis and atherosclerosis. LDs' size range from fraction to one hundred of micrometers in adipocytes and is related to the lipid content, but their growth is still a puzzling question. It has been suggested that LDs can grow in size due to the fusion process by which a larger LD is obtained by the merging of two smaller LDs, but these events seems to be rare and difficult to be observed. Many other processes are thought to be involved in the number and growth of LDs, like the de novo formation and the growth through additional neutral lipid deposition in pre-existing droplets. Moreover the number and size of LDs are influenced by the catabolism and the absorption or interaction with other organelles. The comprehension of these processes could help in the confinement of the pathologies related to lipid accumulation. In this study the LDs' size distribution, number and the total volume of immature (n=12), mature (n=12, 10-days differentiated) and lipolytic (n=12) 3T3-L1 adipocytes were considered. More than 11,000 LDs were measured in the 36 cells after Oil Red O staining. In a previous work Monte Carlo simulations were used to mimic the fusion process alone between LDs. We found that, considering the fusion as the only process acting on the LDs, the size distribution in mature adipocytes can be obtained with numerical simulation starting from the size distribution in immature cells provided a very high rate of fusion events. In this paper Monte Carlo simulations were developed to mimic the interaction between LDs taking into account many other processes in addition to fusion (de novo formation and the growth through additional neutral lipid deposition in pre-existing droplets) in order to reproduce the LDs growth and we also simulated the catabolism (fission and the decrease through neutral lipid exit from pre-existing droplets) to reproduce their size reduction observed in lipolytic conditions. The results suggest that each single process, considered alone, can not be considered the only responsible for the size variation observed, but more than one of them, playing together, can quite well reproduce the experimental data.
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Affiliation(s)
- Federico Boschi
- Department of Computer Science, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
| | - Vanni Rizzatti
- Department of Medicine, Geriatric Section, University of Verona, Piazzale Stefani 1, 37126 Verona, Italy
| | - Mauro Zamboni
- Department of Medicine, Geriatric Section, University of Verona, Piazzale Stefani 1, 37126 Verona, Italy
| | - Andrea Sbarbati
- Department of Neurological and Movement Sciences, University of Verona, Strada Le Grazie 8, 37134 Verona, Italy
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99914
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Visconti R, Della Monica R, Grieco D. Sustaining the spindle assembly checkpoint to improve cancer therapy. Mol Cell Oncol 2015; 3:e1046583. [PMID: 27308561 PMCID: PMC4845201 DOI: 10.1080/23723556.2015.1046583] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Revised: 04/24/2015] [Accepted: 04/25/2015] [Indexed: 11/27/2022]
Abstract
To prevent chromosome segregation errors, the spindle assembly checkpoint (SAC) delays mitosis exit until proper spindle assembly. We found that the FCP1 phosphatase and its downstream target WEE1 kinase oppose the SAC, promoting mitosis exit despite malformed spindles. We further showed that targeting this pathway might be useful for cancer therapy.
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Affiliation(s)
- Roberta Visconti
- CEINGE Biotecnologie Avanzate, Naples, Italy; IEOS, CNR, Naples, Italy
| | - Rosa Della Monica
- CEINGE Biotecnologie Avanzate, Naples, Italy; DMMBM, University of Naples "Federico II", Naples, Italy
| | - Domenico Grieco
- CEINGE Biotecnologie Avanzate, Naples, Italy; DMMBM, University of Naples "Federico II", Naples, Italy
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99915
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Thiede-Stan NK, Schwab ME. Attractive and repulsive factors act through multi-subunit receptor complexes to regulate nerve fiber growth. J Cell Sci 2015; 128:2403-14. [PMID: 26116576 DOI: 10.1242/jcs.165555] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
In the nervous system, attractive and repulsive factors guide neuronal growth, pathfinding and target innervation during development, learning and regeneration after injury. Repulsive and growth-inhibitory factors, such as some ephrins, semaphorins, netrins and myelin-associated growth inhibitors, restrict nerve fiber growth, whereas neurotrophins, and other ephrins, semaphorins and netrins attract fibers and promote neurite growth. Several of these guidance molecules also play crucial roles in vasculogenesis, and regulate cell migration and tissue formation in different organs. Precise and highly specific signal transduction in space and time is required in all these cases, which primarily depends on the presence and function of specific receptors. Interestingly, many of these ligands act through multi-subunit receptor complexes. In this Commentary, we review the current knowledge of how complexes of the receptors for attractive and repulsive neurite growth regulatory factors are reorganized in a spatial and temporal manner, and reveal the implications that such dynamics have on the signaling events that coordinate neurite fiber growth.
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Affiliation(s)
- Nina K Thiede-Stan
- Brain Research Institute, University of Zurich, Department of Health Sciences & Technology, ETH Zurich, Zurich 8057, Switzerland
| | - Martin E Schwab
- Brain Research Institute, University of Zurich, Department of Health Sciences & Technology, ETH Zurich, Zurich 8057, Switzerland
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99916
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HIPK2 restricts SIRT1 activity upon severe DNA damage by a phosphorylation-controlled mechanism. Cell Death Differ 2015; 23:110-22. [PMID: 26113041 PMCID: PMC4815982 DOI: 10.1038/cdd.2015.75] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 05/04/2015] [Accepted: 05/06/2015] [Indexed: 01/23/2023] Open
Abstract
Upon severe DNA damage a cellular signalling network initiates a cell death response through activating tumour suppressor p53 in association with promyelocytic leukaemia (PML) nuclear bodies. The deacetylase Sirtuin 1 (SIRT1) suppresses cell death after DNA damage by antagonizing p53 acetylation. To facilitate efficient p53 acetylation, SIRT1 function needs to be restricted. How SIRT1 activity is regulated under these conditions remains largely unclear. Here we provide evidence that SIRT1 activity is limited upon severe DNA damage through phosphorylation by the DNA damage-responsive kinase HIPK2. We found that DNA damage provokes interaction of SIRT1 and HIPK2, which phosphorylates SIRT1 at Serine 682 upon lethal damage. Furthermore, upon DNA damage SIRT1 and HIPK2 colocalize at PML nuclear bodies, and PML depletion abrogates DNA damage-induced SIRT1 Ser682 phosphorylation. We show that Ser682 phosphorylation inhibits SIRT1 activity and impacts on p53 acetylation, apoptotic p53 target gene expression and cell death. Mechanistically, we found that DNA damage-induced SIRT1 Ser682 phosphorylation provokes disruption of the complex between SIRT1 and its activator AROS. Our findings indicate that phosphorylation-dependent restriction of SIRT1 activity by HIPK2 shapes the p53 response.
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99917
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Eriksson A, Lennartsson A, Lehmann S. Epigenetic aberrations in acute myeloid leukemia: Early key events during leukemogenesis. Exp Hematol 2015; 43:609-24. [PMID: 26118500 DOI: 10.1016/j.exphem.2015.05.009] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 05/23/2015] [Indexed: 12/17/2022]
Abstract
As a result of the introduction of new sequencing technologies, the molecular landscape of acute myeloid leukemia (AML) is rapidly evolving. From karyotyping, which detects only large genomic aberrations of metaphase chromosomes, we have moved into an era when sequencing of each base pair allows us to define the AML genome at highest resolution. This has revealed a new complex landscape of genetic aberrations where addition of mutations in epigenetic regulators has been one of the most important contributions to the understanding of the pathogenesis of AML. These findings, together with new insights into epigenetic mechanisms, have placed dysregulated epigenetic mechanisms at the forefront of AML development. Not only have several new mutations in genes directly involved in epigenetic regulatory mechanisms been discovered, but also previously well-known gene fusions have been found to exert aberrant effects through epigenetic mechanisms. In addition, mutations in epigenetic regulators such as DNMT3A, TET2, and ASXL1 have recently been found to be the earliest known events during AML evolution and to be present as preleukemic lesions before the onset of AML. In this article, we review epigenetic changes in AML also in relation to what is known about their mechanism of action and their prognostic role.
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Affiliation(s)
- Anna Eriksson
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Andreas Lennartsson
- Department of Biosciences and Nutrition, NOVUM, Karolinska Institutet, Stockholm, Sweden
| | - Sören Lehmann
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden; Centre of Hematology, HERM, Department of Medicine, Karolinska Institute, Huddinge, Stockholm, Sweden.
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99918
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Comparative Analysis of Transmembrane Regulators of the Filamentous Growth Mitogen-Activated Protein Kinase Pathway Uncovers Functional and Regulatory Differences. EUKARYOTIC CELL 2015; 14:868-83. [PMID: 26116211 DOI: 10.1128/ec.00085-15] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 06/17/2015] [Indexed: 12/14/2022]
Abstract
Filamentous growth is a microbial differentiation response that involves the concerted action of multiple signaling pathways. In budding yeast, one pathway that regulates filamentous growth is a Cdc42p-dependent mitogen-activated protein kinase (MAPK) pathway. Several transmembrane (TM) proteins regulate the filamentous growth pathway, including the signaling mucin Msb2p, the tetraspan osmosensor Sho1p, and an adaptor Opy2p. The TM proteins were compared to identify common and unique features. Msb2p, Sho1p, and Opy2p associated by coimmunoprecipitation analysis but showed predominantly different localization patterns. The different localization patterns of the proteins resulted in part from different rates of turnover from the plasma membrane (PM). In particular, Msb2p (and Opy2p) were turned over rapidly compared to Sho1p. Msb2p signaled from the PM, and its turnover was a rate-limiting step in MAPK signaling. Genetic analysis identified unique phenotypes of cells overexpressing the TM proteins. Therefore, each TM regulator of the filamentous growth pathway has its own regulatory pattern and specific function in regulating filamentous growth. This specialization may be important for fine-tuning and potentially diversifying the filamentation response.
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99919
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Gelens L, Anderson GA, Ferrell JE. Spatial trigger waves: positive feedback gets you a long way. Mol Biol Cell 2015; 25:3486-93. [PMID: 25368427 PMCID: PMC4230609 DOI: 10.1091/mbc.e14-08-1306] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Trigger waves are a recurring biological phenomenon involved in transmitting information quickly and reliably over large distances. Well-characterized examples include action potentials propagating along the axon of a neuron, calcium waves in various tissues, and mitotic waves in Xenopus eggs. Here we use the FitzHugh-Nagumo model, a simple model inspired by the action potential that is widely used in physics and theoretical biology, to examine different types of trigger waves-spatial switches, pulses, and oscillations-and to show how they arise.
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Affiliation(s)
- Lendert Gelens
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305-5174 Applied Physics Research Group, Vrije Universiteit Brussel (VUB), 1050 Brussels, Belgium
| | - Graham A Anderson
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305-5174
| | - James E Ferrell
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305-5174
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99920
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Bertazzi DL, De Craene JO, Bär S, Sanjuan-Vazquez M, Raess MA, Friant S. [Phosphoinositides: lipidic essential actors in the intracellular traffic]. Biol Aujourdhui 2015; 209:97-109. [PMID: 26115715 DOI: 10.1051/jbio/2015006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Indexed: 06/04/2023]
Abstract
Phosphoinositides (PPIn) are lipids involved in the vesicular transport of proteins between the different intracellular compartments. They act by recruiting and/or activating effector proteins and are thus involved in crucial cellular functions including vesicle budding, fusion and dynamics of membranes and regulation of the cytoskeleton. Although they are present in low concentrations in membranes, their activity is essential for cell survival and needs to be tightly controlled. Therefore, phosphatases and kinases specific of the various cellular membranes can phosphorylate/dephosphorylate their inositol ring on the positions D3, D4 and/or D5. The differential phosphorylation determines the intracellular localisation and the activity of the PPIn. Indeed, non-phosphorylated phosphatidylinositol (PtdIns) is the basic component of the PPIn and can be found in all eukaryotic cells at the cytoplasmic face of the ER, the Golgi, mitochondria and microsomes. It can get phosphorylated on position D4 to obtain PtdIns4P, a PPIn enriched in the Golgi compartment and involved in the maintenance of this organelle as well as anterograde and retrograde transport to and from the Golgi. PtdIns phosphorylation on position D3 results in PtdIns3P that is required for endosomal transport and multivesicular body (MVB) formation and sorting. These monophosphorylated PtdIns can be further phosphorylated to produce bisphophorylated PtdIns. Thus, PtdIns(4,5)P2, mainly produced by PtdIns4P phosphorylation, is enriched in the plasma membrane and involved in the regulation of actin cytoskeleton and endocytosis. PtdIns(3,5)P2, mainly produced by PtdIns3P phosphorylation, is enriched in late endosomes, MVBs and the lysosome/vacuole and plays a role in endosome to vacuole transport. PtdIns(3,4)P2 is absent in yeast, cells and mainly produced by PtdIns4P phosphorylation in human cells; PtdIns(3,4)P2 is localised in the plasma membrane and plays an important role as a second messenger by recruiting specific protein kinases (Akt and PDK1). Finally the triple phosphorylated PPIn, PtdIns(3,4,5)P3 also absent in yeast, is produced by the phosphorylation of PtdIns(3,4)P2 and localized at the plasma membrane of human cells where it binds proteins via their PH domain. Interaction partners include members of the Arf (ADP-ribosylation factors) family, PDK1 (Phosphoinositide Dependent Kinase 1) and Akt. Therefore this last PPIn is essential for the control of cell proliferation and its deregulation leads to the development of numerous cancers. In conclusion, the regulation of PPIn phosphorylation/dephosphorylation is complex and needs to be very precisely regulated. Indeed phosphatases and kinases allow the maintenance of the equilibrium between the different forms. PPIn play a crucial role in numerous cellular functions and a loss in their synthesis or regulation results in severe genetic diseases.
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99921
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Functional Analysis of Sterol Transporter Orthologues in the Filamentous Fungus Aspergillus nidulans. EUKARYOTIC CELL 2015; 14:908-21. [PMID: 26116213 DOI: 10.1128/ec.00027-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Accepted: 06/24/2015] [Indexed: 11/20/2022]
Abstract
Polarized growth in filamentous fungi needs a continuous supply of proteins and lipids to the growing hyphal tip. One of the important membrane compounds in fungi is ergosterol. At the apical plasma membrane ergosterol accumulations, which are called sterol-rich plasma membrane domains (SRDs). The exact roles and formation mechanism of the SRDs remained unclear, although the importance has been recognized for hyphal growth. Transport of ergosterol to hyphal tips is thought to be important for the organization of the SRDs. Oxysterol binding proteins, which are conserved from yeast to human, are involved in nonvesicular sterol transport. In Saccharomyces cerevisiae seven oxysterol-binding protein homologues (OSH1 to -7) play a role in ergosterol distribution between closely located membranes independent of vesicle transport. We found five homologous genes (oshA to oshE) in the filamentous fungi Aspergillus nidulans. The functions of OshA-E were characterized by gene deletion and subcellular localization. Each gene-deletion strain showed characteristic phenotypes and different sensitivities to ergosterol-associated drugs. Green fluorescent protein-tagged Osh proteins showed specific localization in the late Golgi compartments, puncta associated with the endoplasmic reticulum, or diffusely in the cytoplasm. The genes expression and regulation were investigated in a medically important species Aspergillus fumigatus, as well as A. nidulans. Our results suggest that each Osh protein plays a role in ergosterol distribution at distinct sites and contributes to proper fungal growth.
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99922
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Loss of the obscurin-RhoGEF downregulates RhoA signaling and increases microtentacle formation and attachment of breast epithelial cells. Oncotarget 2015; 5:8558-68. [PMID: 25261370 PMCID: PMC4226704 DOI: 10.18632/oncotarget.2338] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Obscurins are RhoGEF-containing proteins whose downregulation has been implicated in the development and progression of breast cancer. Herein, we aim to elucidate the mechanism for increased motility of obscurin-deficient cells. We show that shRNA-mediated obscurin downregulation in MCF10A cells leads to >50% reduction in RhoA activity relative to scramble control (shCtrl), as well as decreased phosphorylation of RhoA effectors, including myosin light chain phosphatase, myosin light chain, lim kinase, and cofilin, in both attached and suspended cells. These alterations result in decreased actomyosin contractility, allowing suspended cells to escape detachment-induced apoptosis. Moreover, ~40% of shObsc-expressing cells, but only ~10% of shCtrl-expressing cells, extend microtentacles, tubulin-based projections that mediate the attachment of circulating tumor cells to endothelium. Indeed, we show that MCF10A cells expressing shObsc attach in vitro more readily than shCtrl cells, an advantage that persists following taxane exposure. Overall, our data suggest that loss of obscurins may represent a substantial selective advantage for breast epithelial cells during metastasis, and that treatment with paclitaxel may exacerbate this advantage by preferentially allowing obscurin-deficient, stem-like cells to attach to the endothelium of distant sites, a first step towards colonizing metastatic tumors.
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99923
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Vymětalová L, Kryštof V. Potential Clinical Uses of CDK Inhibitors: Lessons from Synthetic Lethality Screens. Med Res Rev 2015; 35:1156-74. [DOI: 10.1002/med.21354] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 04/24/2015] [Accepted: 05/23/2015] [Indexed: 01/03/2023]
Affiliation(s)
- Ladislava Vymětalová
- Laboratory of Growth Regulators; Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University and Institute of Experimental Botany AS CR; Šlechtitelů 11 CZ-78371 Olomouc Czech Republic
| | - Vladimír Kryštof
- Laboratory of Growth Regulators; Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University and Institute of Experimental Botany AS CR; Šlechtitelů 11 CZ-78371 Olomouc Czech Republic
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99924
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Geyer M, Huang F, Sun Y, Vogel SM, Malik AB, Taylor CW, Komarova YA. Microtubule-Associated Protein EB3 Regulates IP3 Receptor Clustering and Ca(2+) Signaling in Endothelial Cells. Cell Rep 2015; 12:79-89. [PMID: 26119739 PMCID: PMC4487770 DOI: 10.1016/j.celrep.2015.06.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Revised: 03/27/2015] [Accepted: 05/31/2015] [Indexed: 01/12/2023] Open
Abstract
The mechanisms by which the microtubule cytoskeleton regulates the permeability of endothelial barrier are not well understood. Here, we demonstrate that microtubule-associated end-binding protein 3 (EB3), a core component of the microtubule plus-end protein complex, binds to inositol 1,4,5-trisphosphate receptors (IP3Rs) through an S/TxIP EB-binding motif. In endothelial cells, α-thrombin, a pro-inflammatory mediator that stimulates phospholipase Cβ, increases the cytosolic Ca(2+) concentration and elicits clustering of IP3R3s. These responses, and the resulting Ca(2+)-dependent phosphorylation of myosin light chain, are prevented by depletion of either EB3 or mutation of the TxIP motif of IP3R3 responsible for mediating its binding to EB3. We also show that selective EB3 gene deletion in endothelial cells of mice abrogates α-thrombin-induced increase in endothelial permeability. We conclude that the EB3-mediated interaction of IP3Rs with microtubules controls the assembly of IP3Rs into effective Ca(2+) signaling clusters, which thereby regulate microtubule-dependent endothelial permeability.
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Affiliation(s)
- Melissa Geyer
- Department of Pharmacology and The Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, IL 60612, USA
| | - Fei Huang
- Department of Pharmacology and The Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, IL 60612, USA
| | - Ying Sun
- Department of Pharmacology and The Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, IL 60612, USA
| | - Stephen M Vogel
- Department of Pharmacology and The Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, IL 60612, USA
| | - Asrar B Malik
- Department of Pharmacology and The Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, IL 60612, USA
| | - Colin W Taylor
- Department of Pharmacology, University of Cambridge, Cambridge CB2 1PD, UK
| | - Yulia A Komarova
- Department of Pharmacology and The Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, IL 60612, USA.
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99925
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Affiliation(s)
- Spiros Linardopoulos
- Cancer Research
UK Cancer Therapeutics Unit, The Institute of Cancer Research, London SM2 5NG, U.K
- Breakthrough Breast
Cancer Research Centre, The Institute of Cancer Research, London SW3 6JB, U.K
| | - Julian Blagg
- Cancer Research
UK Cancer Therapeutics Unit, The Institute of Cancer Research, London SM2 5NG, U.K
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99926
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Li FF, Zhou J, Zhao DD, Yan P, Li X, Han Y, Li XS, Wang GY, Yu KJ, Liu SL. Characterization of SMAD3 Gene Variants for Possible Roles in Ventricular Septal Defects and Other Congenital Heart Diseases. PLoS One 2015; 10:e0131542. [PMID: 26110764 PMCID: PMC4482402 DOI: 10.1371/journal.pone.0131542] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Accepted: 06/03/2015] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Nodal/TGF signaling pathway has an important effect at early stages of differentiation of human embryonic stem cells in directing them to develop into different embryonic lineages. SMAD3 is a key intracellular messenger regulating factor in the Nodal/TGF signaling pathway, playing important roles in embryonic and, particularly, cardiovascular system development. The aim of this work was to find evidence on whether SMAD3 variations might be associated with ventricular septal defects (VSD) or other congenital heart diseases (CHD). METHODS We sequenced the SMAD3 gene for 372 Chinese Han CHD patients including 176 VSD patients and evaluated SNP rs2289263, which is located before the 5'UTR sequence of the gene. The statistical analyses were conducted using Chi-Square Tests as implemented in SPSS (version 13.0). The Hardy-Weinberg equilibrium test of the population was carried out using the online software OEGE. RESULTS Three heterozygous variants in SMAD3 gene, rs2289263, rs35874463 and rs17228212, were identified. Statistical analyses showed that the rs2289263 variant located before the 5'UTR sequence of SMAD3 gene was associated with the risk of VSD (P value=0.013 <0.05). CONCLUSIONS The SNP rs2289263 in the SMAD3 gene is associated with VSD in Chinese Han populations.
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Affiliation(s)
- Fei-Feng Li
- Genomics Research Center (one of the State-Province Key Laboratory of Biopharmaceutical Engineering, China), Harbin Medical University, Harbin, China
| | - Jing Zhou
- Intensive Care Unit, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Dan-Dan Zhao
- Genomics Research Center (one of the State-Province Key Laboratory of Biopharmaceutical Engineering, China), Harbin Medical University, Harbin, China
| | - Peng Yan
- Department of Colorectal Surgery, the Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Xia Li
- Genomics Research Center (one of the State-Province Key Laboratory of Biopharmaceutical Engineering, China), Harbin Medical University, Harbin, China
| | - Ying Han
- Genomics Research Center (one of the State-Province Key Laboratory of Biopharmaceutical Engineering, China), Harbin Medical University, Harbin, China
| | | | - Gui-Yu Wang
- Department of Colorectal Surgery, the Second Affiliated Hospital of Harbin Medical University, Harbin, China
- * E-mail: (GYW); (KJY); (SLL)
| | - Kai-Jiang Yu
- Intensive Care Unit, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
- * E-mail: (GYW); (KJY); (SLL)
| | - Shu-Lin Liu
- Genomics Research Center (one of the State-Province Key Laboratory of Biopharmaceutical Engineering, China), Harbin Medical University, Harbin, China
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, Canada
- * E-mail: (GYW); (KJY); (SLL)
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99927
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Neurotensin (NTS) and its receptor (NTSR1) causes EGFR, HER2 and HER3 over-expression and their autocrine/paracrine activation in lung tumors, confirming responsiveness to erlotinib. Oncotarget 2015; 5:8252-69. [PMID: 25249545 PMCID: PMC4226681 DOI: 10.18632/oncotarget.1633] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Alterations in the signaling pathways of epidermal growth factor receptors (HERs) are associated with tumor aggressiveness. Neurotensin (NTS) and its high affinity receptor (NTSR1) are up regulated in 60% of lung cancers. In a previous clinical study, NTSR1 overexpression was shown to predict a poor prognosis for 5 year overall survival in a selected population of stage I lung adenocarcinomas treated by surgery alone. In a second study, shown here, the frequent and high expression of NTSR1 was correlated with a pejorative prognosis in 389 patients with stage I to III lung adenocarcinoma, and was an independent prognosis marker. Interactions between NTS and NTSR1 induce pro-oncogenic biological effects associated with neoplastic processes and tumor progression. Here we highlight the cellular mechanisms activated by Neurotensin (NTS) and its high affinity receptor (NTSR1) contributing to lung cancer cell aggressiveness. We show that the NTS autocrine and/or paracrine regulation causes EGFR, HER2, and HER3 over-expression and activation in lung tumor cells. The EGFR and HER3 autocrine activation is mediated by MMP1 activation and EGF "like" ligands (HB-EGF, Neuregulin 1) release. By establishing autocrine and/or paracrine NTS regulation, we show that tumor growth is modulated according to NTS expression, with a low growth rate in those tumors that do not express NTS. Accordingly, xenografted tumors expressing NTS and NTSR1 showed a positive response to erlotinib, whereas tumors void of NTSR1 expression had no detectable response. This is consistent with the presence of a NTS autocrine loop, leading to the sustained activation of EGFR and responsible for cancer aggressiveness. We propose the use of NTS/NTSR1 tumor expression, as a biomarker for the use of EGFR tyrosine kinase inhibitors in patients lacking EGFR mutation.
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99928
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Elbaz-Alon Y, Eisenberg-Bord M, Shinder V, Stiller SB, Shimoni E, Wiedemann N, Geiger T, Schuldiner M. Lam6 Regulates the Extent of Contacts between Organelles. Cell Rep 2015; 12:7-14. [PMID: 26119743 PMCID: PMC4518459 DOI: 10.1016/j.celrep.2015.06.022] [Citation(s) in RCA: 148] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 05/10/2015] [Accepted: 06/08/2015] [Indexed: 11/16/2022] Open
Abstract
Communication between organelles is crucial for eukaryotic cells to function as one coherent unit. An important means of communication is through membrane contact sites, where two organelles come into close proximity allowing the transport of lipids and small solutes between them. Contact sites are dynamic in size and can change in response to environmental or cellular stimuli; however, how this is regulated has been unclear. Here, we show that Saccharomyces cerevisiae Lam6 resides in several central contact sites: ERMES (ER/mitochondria encounter structure), vCLAMP (vacuole and mitochondria patch), and NVJ (nuclear vacuolar junction). We show that Lam6 is sufficient for expansion of contact sites under physiological conditions and necessary for coordination of contact site size. Given that Lam6 is part of a large protein family and is conserved in vertebrates, our work opens avenues for investigating the underlying principles of organelle communication. Lam6 is localized to three major cellular contacts: ERMES, vCLAMP, and NVJ Lam6 is a GRAM domain protein conserved from yeast to humans Overexpression of Lam6 results in the expansion of all three contact sites Lam6 is essential for the cross-talk between ERMES and vCLAMP
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Affiliation(s)
- Yael Elbaz-Alon
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Michal Eisenberg-Bord
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Vera Shinder
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Sebastian Berthold Stiller
- Institut für Biochemie und Molekularbiologie, Zentrum für Biochemie und Molekulare Zellforschung (ZBMZ), Universität Freiburg, Freiburg 79104, Germany; Fakultät für Biologie, Universität Freiburg, Freiburg 79104, Germany
| | - Eyal Shimoni
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Nils Wiedemann
- Institut für Biochemie und Molekularbiologie, Zentrum für Biochemie und Molekulare Zellforschung (ZBMZ), Universität Freiburg, Freiburg 79104, Germany; BIOSS Centre for Biological Signalling Studies, Universität Freiburg, Freiburg 79104, Germany
| | - Tamar Geiger
- Department of Human Molecular Genetics and Biochemistry, Tel-Aviv University, Tel Aviv 6997801, Israel
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel.
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99929
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Abstract
Peripheral nerve injuries remain problematic to treat, with poor functional recovery commonly observed. Injuries resulting in a nerve gap create specific difficulties for axonal regeneration. Approaches to address these difficulties include autologous nerve grafts (which are currently the gold standard treatment) and synthetic conduits, with the latter option being able to be impregnated with Schwann cells or stem cells which provide an appropriate micro-environment for neuronal regeneration to occur. Transplanting stem cells, however, infers additional risk of malignant transformation as well as manufacturing difficulties and ethical concerns, and the use of autologous nerve grafts and Schwann cells requires the sacrifice of a functioning nerve. A new approach utilizing exosomes, secreted extracellular vesicles, could avoid these complications. In this review, we summarize the current literature on exosomes, and suggest how they could help to improve axonal regeneration following peripheral nerve injury.
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Affiliation(s)
- Rosanna C Ching
- Department of Integrative Medical Biology, Umeå University, Umeå, SE-901 87, Sweden ; Department of Surgical & Perioperative Sciences, Umeå University, Umeå, SE-901 87, Sweden
| | - Paul J Kingham
- Department of Integrative Medical Biology, Umeå University, Umeå, SE-901 87, Sweden
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99930
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Adaptive rheology and ordering of cell cytoskeleton govern matrix rigidity sensing. Nat Commun 2015; 6:7525. [PMID: 26109233 PMCID: PMC4599139 DOI: 10.1038/ncomms8525] [Citation(s) in RCA: 166] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 05/16/2015] [Indexed: 12/23/2022] Open
Abstract
Matrix rigidity sensing regulates a large variety of cellular processes and has important implications for tissue development and disease. However, how cells probe matrix rigidity, and hence respond to it, remains unclear. Here, we show that rigidity sensing and adaptation emerge naturally from actin cytoskeleton remodeling. Our in vitro experiments and theoretical modeling demonstrate a bi-phasic rheology of the actin cytoskeleton, which transitions from fluid on soft substrates to solid on stiffer ones. Furthermore, we find that increasing substrate stiffness correlates with the emergence of an orientational order in actin stress fibers, which exhibit an isotropic to nematic transition that we characterize quantitatively in the framework of active matter theory. These findings imply mechanisms mediated by a large-scale reinforcement of actin structures under stress, which could be the mechanical drivers of substrate stiffness dependent cell shape changes and cell polarity.
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99931
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Gamba P, Jonker MJ, Hamoen LW. A Novel Feedback Loop That Controls Bimodal Expression of Genetic Competence. PLoS Genet 2015; 11:e1005047. [PMID: 26110430 PMCID: PMC4482431 DOI: 10.1371/journal.pgen.1005047] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2014] [Accepted: 02/01/2015] [Indexed: 01/25/2023] Open
Abstract
Gene expression can be highly heterogeneous in isogenic cell populations. An extreme type of heterogeneity is the so-called bistable or bimodal expression, whereby a cell can differentiate into two alternative expression states. Stochastic fluctuations of protein levels, also referred to as noise, provide the necessary source of heterogeneity that must be amplified by specific genetic circuits in order to obtain a bimodal response. A classical model of bimodal differentiation is the activation of genetic competence in Bacillus subtilis. The competence transcription factor ComK activates transcription of its own gene, and an intricate regulatory network controls the switch to competence and ensures its reversibility. However, it is noise in ComK expression that determines which cells activate the ComK autostimulatory loop and become competent for genetic transformation. Despite its important role in bimodal gene expression, noise remains difficult to investigate due to its inherent stochastic nature. We adapted an artificial autostimulatory loop that bypasses all known ComK regulators to screen for possible factors that affect noise. This led to the identification of a novel protein Kre (YkyB) that controls the bimodal regulation of ComK. Interestingly, Kre appears to modulate the induction of ComK by affecting the stability of comK mRNA. The protein influences the expression of many genes, however, Kre is only found in bacteria that contain a ComK homologue and, importantly, kre expression itself is downregulated by ComK. The evolutionary significance of this new feedback loop for the reduction of transcriptional noise in comK expression is discussed. Our findings show the importance of mRNA stability in bimodal regulation, a factor that requires more attention when studying and modelling this non-deterministic developmental mechanism. Gene expression can be highly heterogeneous in clonal cell populations. An extreme type of heterogeneity is the so-called bistable or bimodal expression, whereby a cell can differentiate into two alternative expression states, and consequently a population will be composed of cells that are ‘ON’ and cells that are ‘OFF’. Stochastic fluctuations of protein levels, also referred to as noise, provide the necessary source of heterogeneity that must be amplified by autostimulatory feedback regulation to obtain the bimodal response. A classical model of bistable differentiation is the development of genetic competence in Bacillus subtilis. Noise in expression of the transcription factor ComK ultimately determines the fraction of cells that enter the competent state. Due to its intrinsic random nature, noise is difficult to investigate. We adapted an artificial autostimulatory loop that bypasses all known ComK regulators, to screen for possible factors that affect noise in the bimodal regulation of ComK. This led to the discovery of Kre, a novel factor that controls the bimodal expression of ComK. Kre appears to affect the stability of comK mRNA. Interestingly, ComK itself represses the expression of kre, adding a new double negative feedback loop to the intricate ComK regulation circuit. Our data emphasize that mRNA stability is an important factor in bimodal regulation.
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Affiliation(s)
- Pamela Gamba
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
- * E-mail: (PG); (LWH)
| | - Martijs J. Jonker
- MicroArray Department and Integrative Bioinformatics Unit, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Leendert W. Hamoen
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
- Bacterial Cell Biology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
- * E-mail: (PG); (LWH)
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99932
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Bastos LGDR, de Marcondes PG, de-Freitas-Junior JCM, Leve F, Mencalha AL, de Souza WF, de Araujo WM, Tanaka MN, Abdelhay ESFW, Morgado-Díaz JA. Progeny from irradiated colorectal cancer cells acquire an EMT-like phenotype and activate Wnt/β-catenin pathway. J Cell Biochem 2015; 115:2175-87. [PMID: 25103643 DOI: 10.1002/jcb.24896] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 08/01/2014] [Indexed: 12/20/2022]
Abstract
Radiotherapy remains a major approach to adjuvant therapy for patients with advanced colorectal cancer, however, the fractionation schedules frequently allow for the repopulation of surviving tumors cells, neoplastic progression, and subsequent metastasis. The aim of the present study was to analyze the transgenerational effects induced by radiation and evaluate whether it could increase the malignant features on the progeny derived from irradiated parental colorectal cancer cells, Caco-2, HT-29, and HCT-116. The progeny of these cells displayed a differential radioresistance as seen by clonogenic and caspase activation assay and had a direct correlation with survivin expression as observed by immunoblotting. Immunofluorescence showed that the most radioresistant progenies had an aberrant morphology, disturbance of the cell-cell adhesion contacts, disorganization of the actin cytoskeleton, and vimentin filaments. Only the progeny derived from intermediary radioresistant cells, HT-29, reduced the E-cadherin expression and overexpressed β-catenin and vimentin with increased cell migration, invasion, and metalloprotease activation as seen by immunoblotting, wound healing, invasion, and metalloprotease activity assay. We also observed that this most aggressive progeny increased the Wnt/β-catenin-dependent TCF/LEF activity and underwent an upregulation of mesenchymal markers and downregulation of E-cadherin, as determined by qRT-PCR. Our results showed that the intermediate radioresistant cells can generate more aggressive cellular progeny with the EMT-like phenotype. The Wnt/β-catenin pathway may constitute an important target for new adjuvant treatment schedules with radiotherapy, with the goal of reducing the migratory and invasive potential of the remaining cells after treatment.
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Affiliation(s)
- Lilian Gonçalves dos Reis Bastos
- Cellular Biology Program, Brazilian National Cancer Institute (INCA), 37André Cavalcanti Street, 5th Floor, Rio de Janeiro, RJ, 20230-051, Brazil
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99933
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Multifaceted roles of HSF1 in cancer. Tumour Biol 2015; 36:4923-31. [PMID: 26108999 DOI: 10.1007/s13277-015-3674-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 06/15/2015] [Indexed: 12/15/2022] Open
Abstract
Heat shock transcription factor 1 (HSF1) is the master regulator of the heat shock response. Accumulating evidence shows that HSF1 is overexpressed in a variety of human cancers, is associated with cancer aggressiveness, and could serve as an independent diagnostic or prognostic biomarker. In this review, we will provide an overview of the multifaceted roles of HSF1 in cancer, with a special focus on the four underlying molecular mechanisms involved. First, HSF1 regulates the expression of heat shock proteins (HSPs) including HSP90, HSP70, and HSP27. Second, HSF1 regulates cellular metabolism, including glycolysis and lipid metabolism. Third, HSF1 serves as a regulator of different signaling pathways, such as HuR-HIF-1, Slug, protein kinase C (PKC), nuclear factor-kappaB (NF-κB), PI3K-AKT-mTOR, and mitogen-activated protein kinase (MAPK) pathways. Finally, HSF1 regulates microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). Overall, HSF1 plays many important roles in cancer via regulating cell proliferation, anti-apoptosis, epithelial-mesenchymal transition (EMT), migration, invasion, and metastasis and may be a potential therapeutic target for human cancers.
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99934
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Mirrashidi KM, Elwell CA, Verschueren E, Johnson JR, Frando A, Von Dollen J, Rosenberg O, Gulbahce N, Jang G, Johnson T, Jäger S, Gopalakrishnan AM, Sherry J, Dunn JD, Olive A, Penn B, Shales M, Cox JS, Starnbach MN, Derre I, Valdivia R, Krogan NJ, Engel J. Global Mapping of the Inc-Human Interactome Reveals that Retromer Restricts Chlamydia Infection. Cell Host Microbe 2015; 18:109-21. [PMID: 26118995 DOI: 10.1016/j.chom.2015.06.004] [Citation(s) in RCA: 138] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 04/28/2015] [Accepted: 06/05/2015] [Indexed: 01/02/2023]
Abstract
Chlamydia trachomatis is a leading cause of genital and ocular infections for which no vaccine exists. Upon entry into host cells, C. trachomatis resides within a membrane-bound compartment—the inclusion—and secretes inclusion membrane proteins (Incs) that are thought to modulate the host-bacterium interface. To expand our understanding of Inc function(s), we subjected putative C. trachomatis Incs to affinity purification-mass spectroscopy (AP-MS). We identified Inc-human interactions for 38/58 Incs with enrichment in host processes consistent with Chlamydia's intracellular life cycle. There is significant overlap between Inc targets and viral proteins, suggesting common pathogenic mechanisms among obligate intracellular microbes. IncE binds to sorting nexins (SNXs) 5/6, components of the retromer, which relocalizes SNX5/6 to the inclusion membrane and augments inclusion membrane tubulation. Depletion of retromer components enhances progeny production, revealing that retromer restricts Chlamydia infection. This study demonstrates the value of proteomics in unveiling host-pathogen interactions in genetically challenging microbes.
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Affiliation(s)
- Kathleen M Mirrashidi
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Cherilyn A Elwell
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Erik Verschueren
- QB3, California Institute for Quantitative Biosciences, San Francisco, CA 94148, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Jeffrey R Johnson
- QB3, California Institute for Quantitative Biosciences, San Francisco, CA 94148, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Andrew Frando
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - John Von Dollen
- QB3, California Institute for Quantitative Biosciences, San Francisco, CA 94148, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Oren Rosenberg
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Natali Gulbahce
- QB3, California Institute for Quantitative Biosciences, San Francisco, CA 94148, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Gwendolyn Jang
- QB3, California Institute for Quantitative Biosciences, San Francisco, CA 94148, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Tasha Johnson
- QB3, California Institute for Quantitative Biosciences, San Francisco, CA 94148, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Stefanie Jäger
- QB3, California Institute for Quantitative Biosciences, San Francisco, CA 94148, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | | | - Jessica Sherry
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Joe Dan Dunn
- Department of Molecular Genetics and Microbiology, Duke University, Durham, NC 27710, USA
| | - Andrew Olive
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA
| | - Bennett Penn
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Michael Shales
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Gladstone Institutes, San Francisco, CA 94158, USA
| | - Jeffery S Cox
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA
| | | | - Isabelle Derre
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT 06510, USA
| | - Raphael Valdivia
- Department of Molecular Genetics and Microbiology, Duke University, Durham, NC 27710, USA
| | - Nevan J Krogan
- QB3, California Institute for Quantitative Biosciences, San Francisco, CA 94148, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Gladstone Institutes, San Francisco, CA 94158, USA.
| | - Joanne Engel
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA.
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99935
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Rimessi A, Patergnani S, Bonora M, Wieckowski MR, Pinton P. Mitochondrial Ca(2+) Remodeling is a Prime Factor in Oncogenic Behavior. Front Oncol 2015; 5:143. [PMID: 26161362 PMCID: PMC4479728 DOI: 10.3389/fonc.2015.00143] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2015] [Accepted: 06/11/2015] [Indexed: 12/30/2022] Open
Abstract
Cancer is sustained by defects in the mechanisms underlying cell proliferation, mitochondrial metabolism, and cell death. Mitochondrial Ca2+ ions are central to all these processes, serving as signaling molecules with specific spatial localization, magnitude, and temporal characteristics. Mutations in mtDNA, aberrant expression and/or regulation of Ca2+-handling/transport proteins and abnormal Ca2+-dependent relationships among the cytosol, endoplasmic reticulum, and mitochondria can cause the deregulation of mitochondrial Ca2+-dependent pathways that are related to these processes, thus determining oncogenic behavior. In this review, we propose that mitochondrial Ca2+ remodeling plays a pivotal role in shaping the oncogenic signaling cascade, which is a required step for cancer formation and maintenance. We will describe recent studies that highlight the importance of mitochondria in inducing pivotal “cancer hallmarks” and discuss possible tools to manipulate mitochondrial Ca2+ to modulate cancer survival.
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Affiliation(s)
- Alessandro Rimessi
- Section of Pathology, Oncology and Experimental Biology, Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, University of Ferrara , Ferrara , Italy
| | - Simone Patergnani
- Section of Pathology, Oncology and Experimental Biology, Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, University of Ferrara , Ferrara , Italy
| | - Massimo Bonora
- Section of Pathology, Oncology and Experimental Biology, Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, University of Ferrara , Ferrara , Italy
| | - Mariusz R Wieckowski
- Department of Biochemistry, Nencki Institute of Experimental Biology , Warsaw , Poland
| | - Paolo Pinton
- Section of Pathology, Oncology and Experimental Biology, Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, University of Ferrara , Ferrara , Italy
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99936
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Nijenhuis N, Zhao X, Carisey A, Ballestrem C, Derby B. Combining AFM and acoustic probes to reveal changes in the elastic stiffness tensor of living cells. Biophys J 2015; 107:1502-12. [PMID: 25296302 DOI: 10.1016/j.bpj.2014.07.073] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 07/22/2014] [Accepted: 07/30/2014] [Indexed: 12/20/2022] Open
Abstract
Knowledge of how the elastic stiffness of a cell affects its communication with its environment is of fundamental importance for the understanding of tissue integrity in health and disease. For stiffness measurements, it has been customary to quote a single parameter quantity, e.g., Young's modulus, rather than the minimum of two terms of the stiffness tensor required by elasticity theory. In this study, we use two independent methods (acoustic microscopy and atomic force microscopy nanoindentation) to characterize the elastic properties of a cell and thus determine two independent elastic constants. This allows us to explore in detail how the mechanical properties of cells change in response to signaling pathways that are known to regulate the cell's cytoskeleton. In particular, we demonstrate that altering the tensioning of actin filaments in NIH3T3 cells has a strong influence on the cell's shear modulus but leaves its bulk modulus unchanged. In contrast, altering the polymerization state of actin filaments influences bulk and shear modulus in a similar manner. In addition, we can use the data to directly determine the Poisson ratio of a cell and show that in all cases studied, it is less than, but very close to, 0.5 in value.
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Affiliation(s)
- Nadja Nijenhuis
- School of Materials, Faculty of Engineering and Physical Sciences, Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom; Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Xuegen Zhao
- School of Materials, Faculty of Engineering and Physical Sciences, Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Alex Carisey
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Christoph Ballestrem
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Brian Derby
- School of Materials, Faculty of Engineering and Physical Sciences, Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom.
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99937
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Deubiquitination of Ci/Gli by Usp7/HAUSP Regulates Hedgehog Signaling. Dev Cell 2015; 34:58-72. [PMID: 26120032 DOI: 10.1016/j.devcel.2015.05.016] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Revised: 03/18/2015] [Accepted: 05/19/2015] [Indexed: 01/20/2023]
Abstract
Hedgehog (Hh) signaling plays essential roles in animal development and tissue homeostasis, and its misregulation causes congenital diseases and cancers. Regulation of the ubiquitin/proteasome-mediated proteolysis of Ci/Gli transcription factors is central to Hh signaling, but whether deubiquitinase is involved in this process remains unknown. Here, we show that Hh stimulates the binding of a ubiquitin-specific protease Usp7 to Ci, which positively regulates Hh signaling activity through inhibiting Ci ubiquitination and degradation mediated by both Slimb-Cul1 and Hib-Cul3 E3 ligases. Furthermore, we find that Usp7 forms a complex with GMP-synthetase (GMPS) to promote Hh pathway activity. Finally, we show that the mammalian counterpart of Usp7, HAUSP, positively regulates Hh signaling by modulating Gli ubiquitination and stability. Our findings reveal a conserved mechanism by which Ci/Gli is stabilized by a deubiquitination enzyme and identify Usp7/HUASP as a critical regulator of Hh signaling and potential therapeutic target for Hh-related cancers.
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99938
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Novel Antioxidant Tripeptide "ACQ" Can Prevent UV-Induced Cell Death and Preserve the Number of Epidermal Stem Cells. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015. [PMID: 26199677 PMCID: PMC4496495 DOI: 10.1155/2015/359740] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We found that tripeptide “ACQ: alanine-cysteine-glutamine” has significant DPPH scavenging activity compared to that of glutathione. Antioxidant effects of ACQ were tested in in vitro and in vivo models. When treated with H2O2, mock treated fibroblasts and keratinocytes showed strong staining by H2DCFA. But, ACQ showed good protective effects against hydrogen peroxide treatment. When mice were fed for 2 or 4 weeks, similar protective effects were observed. In the control group, epidermis was severely damaged by UV irradiation and apoptotic keratinocytes were observed. There were also numerous TUNEL positive cells. But in the ACQ group, epidermis became thicker and there was no sign of severe damage. Interestingly, the number of p63 cells was also higher in ACQ fed mice. To confirm the stem cell rescuing effects of ACQ, three-dimensional skin samples were constructed. Results showed that ACQ increased the expression of integrin α6 and the number of p63 positive cells. These findings showed that ACQ has good antioxidant activity and may increase stem cell activities by the regulation of integrin α6.
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99939
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Gonzalez J, Qi H, Liu N, Lin H. Piwi Is a Key Regulator of Both Somatic and Germline Stem Cells in the Drosophila Testis. Cell Rep 2015; 12:150-161. [PMID: 26119740 DOI: 10.1016/j.celrep.2015.06.004] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 02/17/2015] [Accepted: 05/30/2015] [Indexed: 12/11/2022] Open
Abstract
The Piwi-piRNA pathway is well known for its germline function, yet its somatic role remains elusive. We show here that Piwi is required autonomously not only for germline stem cell (GSC) but also for somatic cyst stem cell (CySC) maintenance in the Drosophila testis. Reducing Piwi activity in the testis caused defects in CySC differentiation. Accompanying this, GSC daughters expanded beyond the vicinity of the hub but failed to differentiate further. Moreover, Piwi deficient in nuclear localization caused similar defects in somatic and germ cell differentiation, which was rescued by somatic Piwi expression. To explore the underlying molecular mechanism, we identified Piwi-bound piRNAs that uniquely map to a gene key for gonadal development, Fasciclin 3, and demonstrate that Piwi regulates its expression in somatic cyst cells. Our work reveals the cell-autonomous function of Piwi in both somatic and germline stem cell types, with somatic function possibly via its epigenetic mechanism.
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Affiliation(s)
- Jacob Gonzalez
- Yale Stem Cell Center and Department of Cell Biology, Yale School of Medicine, New Haven, CT 06519, USA
| | - Hongying Qi
- Yale Stem Cell Center and Department of Cell Biology, Yale School of Medicine, New Haven, CT 06519, USA
| | - Na Liu
- Yale Stem Cell Center and Department of Cell Biology, Yale School of Medicine, New Haven, CT 06519, USA
| | - Haifan Lin
- Yale Stem Cell Center and Department of Cell Biology, Yale School of Medicine, New Haven, CT 06519, USA; Shanghai Institute of Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, China.
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99940
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Schneggenburger R, Rosenmund C. Molecular mechanisms governing Ca2+ regulation of evoked and spontaneous release. Nat Neurosci 2015; 18:935-41. [DOI: 10.1038/nn.4044] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 05/09/2015] [Indexed: 12/15/2022]
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99941
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Vasconcelos-Dos-Santos A, Oliveira IA, Lucena MC, Mantuano NR, Whelan SA, Dias WB, Todeschini AR. Biosynthetic Machinery Involved in Aberrant Glycosylation: Promising Targets for Developing of Drugs Against Cancer. Front Oncol 2015; 5:138. [PMID: 26161361 PMCID: PMC4479729 DOI: 10.3389/fonc.2015.00138] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 06/02/2015] [Indexed: 12/22/2022] Open
Abstract
Cancer cells depend on altered metabolism and nutrient uptake to generate and keep the malignant phenotype. The hexosamine biosynthetic pathway is a branch of glucose metabolism that produces UDP-GlcNAc and its derivatives, UDP-GalNAc and CMP-Neu5Ac and donor substrates used in the production of glycoproteins and glycolipids. Growing evidence demonstrates that alteration of the pool of activated substrates might lead to different glycosylation and cell signaling. It is already well established that aberrant glycosylation can modulate tumor growth and malignant transformation in different cancer types. Therefore, biosynthetic machinery involved in the assembly of aberrant glycans are becoming prominent targets for anti-tumor drugs. This review describes three classes of glycosylation, O-GlcNAcylation, N-linked, and mucin type O-linked glycosylation, involved in tumor progression, their biosynthesis and highlights the available inhibitors as potential anti-tumor drugs.
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Affiliation(s)
| | - Isadora A Oliveira
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro , Rio de Janeiro , Brasil
| | - Miguel Clodomiro Lucena
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro , Rio de Janeiro , Brasil
| | - Natalia Rodrigues Mantuano
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro , Rio de Janeiro , Brasil
| | - Stephen A Whelan
- Department of Biochemistry, Cardiovascular Proteomics Center, Boston University School of Medicine , Boston, MA , USA
| | - Wagner Barbosa Dias
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro , Rio de Janeiro , Brasil
| | - Adriane Regina Todeschini
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro , Rio de Janeiro , Brasil
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99942
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DNA Methylation of the EphA5 Promoter Is Associated with Rat Congenital Hypothyroidism. J Mol Neurosci 2015; 57:203-10. [PMID: 26109526 DOI: 10.1007/s12031-015-0603-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 06/09/2015] [Indexed: 12/20/2022]
Abstract
Thyroid hormones (THs) are essential for normal development of the mammalian central nervous system through regulation of TH-responsive genes. EphA5, an important TH-responsive gene encoding the tyrosine kinase receptor EphA5, regulates synaptogenesis initiation and synaptic remodeling during brain development. Abnormal EphA5 expression is involved in the development of congenital hypothyroidism (CH). To show the regulatory mechanism of EphA5 expression in CH rats, we analyzed the correlation between methylation of the EphA5 promoter and its expression in the hypothyroid hippocampus and hippocampal neurons. Demethylation treatment using 5'-azadeoxycytidine upregulated EphA5 expression and rescued the effects of hypermethylation, suggesting a novel regulatory mechanism of EphA5 expression in CH rats. Our results suggest a potentially new approach for the development of drugs to restore neurocognitive impairments associated with CH.
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99943
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Tian X, Wu C. Active zone stability: insights from fly neuromuscular junction. Neural Regen Res 2015; 10:677-8. [PMID: 26109929 PMCID: PMC4468746 DOI: 10.4103/1673-5374.156942] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/20/2015] [Indexed: 11/23/2022] Open
Abstract
The presynaptic active zone is a dynamic structure that orchestrates regulated release of neurotransmitters. Developmental and aging processes, and changes in neuronal network activity can all modulate the number, size and composition of active zone and thereby synaptic efficacy. However, very little is known about the mechanism that controls the structural stability of active zone. By studying a model synapse, the Drosophila neuromuscular junction, our recent work shed light on how two scaffolding proteins at the active zone regulate active zone stability by promoting a localized dephosphorylation event at the nerve terminal. Here we discuss the major insights from our findings and their implications for future research.
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Affiliation(s)
- Xiaolin Tian
- Neuroscience Center of Excellence, Department of Cell Biology and Anatomy, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA, USA
| | - Chunlai Wu
- Neuroscience Center of Excellence, Department of Cell Biology and Anatomy, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA, USA
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99944
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A plastic relationship between vinculin-mediated tension and adhesion complex area defines adhesion size and lifetime. Nat Commun 2015; 6:7524. [PMID: 26109125 PMCID: PMC4491829 DOI: 10.1038/ncomms8524] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 05/16/2015] [Indexed: 01/08/2023] Open
Abstract
Cell-matrix adhesions are central mediators of mechanotransduction, yet the interplay between force and adhesion regulation remains unclear. Here we use live cell imaging to map time-dependent cross-correlations between vinculin-mediated tension and adhesion complex area, revealing a plastic, context-dependent relationship. Interestingly, while an expected positive cross-correlation dominated in mid-sized adhesions, small and large adhesions display negative cross-correlation. Furthermore, although large changes in adhesion complex area follow vinculin-mediated tension alterations, small increases in area precede vinculin-mediated tension dynamics. Modelling based on this mapping of the vinculin-mediated tension-adhesion complex area relationship confirms its biological validity, and indicates that this relationship explains adhesion size and lifetime limits, keeping adhesions focal and transient. We also identify a subpopulation of steady-state adhesions whose size and vinculin-mediated tension become stabilized, and whose disassembly may be selectively microtubule-mediated. In conclusion, we define a plastic relationship between vinculin-mediated tension and adhesion complex area that controls fundamental cell-matrix adhesion properties. Cell-matrix adhesions may increase or decrease in size in response to tension; however, the factors determining which of these responses predominates remain unclear. Hernández-Varas et al. quantify the plastic relationship between adhesion size and tension and use modelling to explain this behaviour.
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99945
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Effects of Artificial Ligaments with Different Porous Structures on the Migration of BMSCs. Stem Cells Int 2015; 2015:702381. [PMID: 26106429 PMCID: PMC4464596 DOI: 10.1155/2015/702381] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Revised: 03/31/2015] [Accepted: 03/31/2015] [Indexed: 01/28/2023] Open
Abstract
Polyethylene terephthalate- (PET-) based artificial ligaments (PET-ALs) are commonly used in anterior cruciate ligament (ACL) reconstruction surgery. The effects of different porous structures on the migration of bone marrow mesenchymal stem cells (BMSCs) on artificial ligaments and the underlying mechanisms are unclear. In this study, a cell migration model was utilized to observe the migration of BMSCs on PET-ALs with different porous structures. A rabbit extra-articular graft-to-bone healing model was applied to investigate the in vivo effects of four types of PET-ALs, and a mechanical test and histological observation were performed at 4 weeks and 12 weeks. The BMSC migration area of the 5A group was significantly larger than that of the other three groups. The migration of BMSCs in the 5A group was abolished by blocking the RhoA/ROCK signaling pathway with Y27632. The in vivo study demonstrated that implantation of 5A significantly improved osseointegration. Our study explicitly demonstrates that the migration ability of BMSCs can be regulated by varying the porous structures of the artificial ligaments and suggests that this regulation is related to the RhoA/ROCK signaling pathway. Artificial ligaments prepared using a proper knitting method and line density may exhibit improved biocompatibility and clinical performance.
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99946
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Cáceres M, Ortiz L, Recabarren T, Romero A, Colombo A, Leiva-Salcedo E, Varela D, Rivas J, Silva I, Morales D, Campusano C, Almarza O, Simon F, Toledo H, Park KS, Trimmer JS, Cerda O. TRPM4 Is a Novel Component of the Adhesome Required for Focal Adhesion Disassembly, Migration and Contractility. PLoS One 2015; 10:e0130540. [PMID: 26110647 PMCID: PMC4482413 DOI: 10.1371/journal.pone.0130540] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 05/21/2015] [Indexed: 11/18/2022] Open
Abstract
Cellular migration and contractility are fundamental processes that are regulated by a variety of concerted mechanisms such as cytoskeleton rearrangements, focal adhesion turnover, and Ca2+ oscillations. TRPM4 is a Ca2+-activated non-selective cationic channel (Ca2+-NSCC) that conducts monovalent but not divalent cations. Here, we used a mass spectrometry-based proteomics approach to identify putative TRPM4-associated proteins. Interestingly, the largest group of these proteins has actin cytoskeleton-related functions, and among these nine are specifically annotated as focal adhesion-related proteins. Consistent with these results, we found that TRPM4 localizes to focal adhesions in cells from different cellular lineages. We show that suppression of TRPM4 in MEFs impacts turnover of focal adhesions, serum-induced Ca2+ influx, focal adhesion kinase (FAK) and Rac activities, and results in reduced cellular spreading, migration and contractile behavior. Finally, we demonstrate that the inhibition of TRPM4 activity alters cellular contractility in vivo, affecting cutaneous wound healing. Together, these findings provide the first evidence, to our knowledge, for a TRP channel specifically localized to focal adhesions, where it performs a central role in modulating cellular migration and contractility.
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Affiliation(s)
- Mónica Cáceres
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Department of Neurobiology, Physiology and Behavior, College of Biological Sciences, University of California Davis, Davis, California, United States of America
| | - Liliana Ortiz
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Tatiana Recabarren
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Programa de Anatomía y Biología del Desarrollo, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Anibal Romero
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Alicia Colombo
- Programa de Anatomía y Biología del Desarrollo, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Elías Leiva-Salcedo
- Section on Cellular Signaling, Program in Developmental Biology, National Institute of Child Health and Human Development (NICHD), National Institute of Health, Bethesda, Maryland, United States of America
| | - Diego Varela
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - José Rivas
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Ian Silva
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Diego Morales
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Camilo Campusano
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Oscar Almarza
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Felipe Simon
- Departamento de Ciencias Biologicas, Facultad de Ciencias Biologicas, Universidad Andres Bello, Santiago, Chile
- Facultad de Medicina, Universidad Andres Bello, Santiago, Chile
- Millennium Institute on Immunology and Immunotherapy, Santiago, Chile
| | - Hector Toledo
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Kang-Sik Park
- Department of Neurobiology, Physiology and Behavior, College of Biological Sciences, University of California Davis, Davis, California, United States of America
- Department of Physiology, School of Medicine, Kyung Hee University, Seoul, Korea
| | - James S. Trimmer
- Department of Neurobiology, Physiology and Behavior, College of Biological Sciences, University of California Davis, Davis, California, United States of America
- Department of Physiology and Membrane Biology, School of Medicine, University of California Davis, Davis, California, United States of America
| | - Oscar Cerda
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Department of Neurobiology, Physiology and Behavior, College of Biological Sciences, University of California Davis, Davis, California, United States of America
- * E-mail:
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99947
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Glogauer JE, Sun CX, Bradley G, Magalhaes MAO. Neutrophils Increase Oral Squamous Cell Carcinoma Invasion through an Invadopodia-Dependent Pathway. Cancer Immunol Res 2015; 3:1218-26. [PMID: 26112922 DOI: 10.1158/2326-6066.cir-15-0017] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 06/16/2015] [Indexed: 11/16/2022]
Abstract
Neutrophils have recently been shown to promote invasion and correlate with a poor prognosis in different cancers, including head and neck squamous cell carcinomas. In this study, we analyze the effects of neutrophils in the invasion of oral squamous cell carcinoma (OSCC) using a combination of conditioned media, direct and indirect coculture of human peripheral blood neutrophils, and UMSCC47 cells (OSCC cell line). Invasion and matrix degradation were determined using a modified in vitro invasion assay and an invadopodia assay, respectively. UMSCC47 and neutrophil cocultures or conditioned media from cocultures increased UMSCC47 invasion, invadopodia formation, and matrix degradation. Further analysis revealed an increase in TNFα and IL8 in supernatants of cocultures compared with neutrophil or UMSCC47 cultures alone and that inhibition of TNFα and IL8 significantly decreased OSCC invasion. Our results show that neutrophils increase the invasiveness of OSCC through the activation of invadopodia and matrix degradation, suggesting a paracrine activation loop between the two cells. Importantly, the presence of neutrophils in the oral environment may modulate the clinical behavior of OSCC.
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Affiliation(s)
- Judah E Glogauer
- Matrix Dynamics group, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada
| | - Chun X Sun
- Matrix Dynamics group, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada
| | - Grace Bradley
- Oral Pathology and Oral Medicine, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada
| | - Marco A O Magalhaes
- Matrix Dynamics group, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada. Oral Pathology and Oral Medicine, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada.
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99948
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Sisakhtnezhad S, Khosravi L. Emerging physiological and pathological implications of tunneling nanotubes formation between cells. Eur J Cell Biol 2015; 94:429-43. [PMID: 26164368 DOI: 10.1016/j.ejcb.2015.06.010] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Revised: 06/20/2015] [Accepted: 06/23/2015] [Indexed: 12/21/2022] Open
Abstract
Cell-to-cell communication is a critical requirement to coordinate behaviors of the cells in a community and thereby achieve tissue homeostasis and conservation of the multicellular organisms. Tunneling nanotubes (TNTs), as a cell-to-cell communication over long distance, allow for bi- or uni-directional transfer of cellular components between cells. Identification of inducing agents and the cell and molecular mechanism underling the formation of TNTs and their structural and functional features may lead to finding new important roles for these intercellular bridges in vivo and in vitro. During the last decade, research has shown TNTs have different structural and functional properties, varying between and within cell systems. In this review, we will focus on TNTs and their cell and molecular mechanism of formation. Moreover, the latest findings into their functional roles in physiological and pathological processes, such as signal transduction, micro and nano-particles delivery, immune responses, embryogenesis, cellular reprogramming, apoptosis, cancer, and neurodegenerative diseases initiation and progression and pathogens transfer, will be discussed.
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Affiliation(s)
| | - Leila Khosravi
- Department of Biology, Faculty of Science, Razi University, Kermanshah, Iran
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99949
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Benzoubir N, Mussini C, Lejamtel C, Dos Santos A, Guillaume C, Desterke C, Samuel D, Bréchot C, Bourgeade MF, Guettier C. Gamma-smooth muscle actin expression is associated with epithelial-mesenchymal transition and stem-like properties in hepatocellular carcinoma. PLoS One 2015; 10:e0130559. [PMID: 26110787 PMCID: PMC4482489 DOI: 10.1371/journal.pone.0130559] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 05/21/2015] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND AND AIMS The prognosis of hepatocellular carcinoma (HCC) is hampered by frequent tumour recurrence and metastases. Epithelial-Mesenchymal Transition (EMT) is now recognized as a key process in tumour invasion, metastasis and the generation of cancer initiating cells. The morphological identification of EMT in tumour samples from the expression of novel mesenchymal markers could provide relevant prognostic information and aid in understanding the metastatic process. METHODS The expression of Smooth Muscle Actins was studied using immunofluorescence and immunohistochemistry assays in cultured liver cells during an induced EMT process and in liver specimens from adult and paediatric HCC series. RESULTS We report here that in HCC cell lines treated with TGF-β and in HCC specimens, the expression of αSMA, a known mesenchymal marker of EMT, could never be detected. In addition, our in vitro studies identified the enteric form of SMA, γSMA, as being a marker of EMT. Moreover, this SMA isoform was expressed in 46% of 58 tumours from 42 adult HCC patients and in 90% of 16 tumours from 12 paediatric HCC patients. Interestingly, this expression was significantly correlated with poor tumour differentiation and progenitor cell features characterized by the expression of EpCAM and K19. CONCLUSION Taken together, our results support the conclusion that γSMA expression in HCC is strongly correlated with the EMT process, HCC aggressiveness and the identification of cancer stem cells. This correlation suggests that γSMA represents a novel and powerful marker to predict HCC progression.
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Affiliation(s)
- Nassima Benzoubir
- Inserm, Unité 785, Villejuif, F-94800, France
- Univ Paris-Sud, UMR-S 785, Villejuif, F-94800, France
- DHU Hepatinov, Villejuif, France
| | - Charlotte Mussini
- AP-HP Hôpital Kremlin-Bicêtre, Service d’Anatomopathologie, Paris, France
- DHU Hepatinov, Villejuif, France
| | - Charlène Lejamtel
- Inserm, Unité 785, Villejuif, F-94800, France
- Univ Paris-Sud, UMR-S 785, Villejuif, F-94800, France
| | - Alexandre Dos Santos
- Inserm, Unité 785, Villejuif, F-94800, France
- Univ Paris-Sud, UMR-S 785, Villejuif, F-94800, France
- DHU Hepatinov, Villejuif, France
| | - Claire Guillaume
- AP-HP Hôpital Kremlin-Bicêtre, Service d’Anatomopathologie, Paris, France
- DHU Hepatinov, Villejuif, France
| | | | - Didier Samuel
- Inserm, Unité 785, Villejuif, F-94800, France
- Univ Paris-Sud, UMR-S 785, Villejuif, F-94800, France
- AP-HP Hôpital Paul Brousse, Centre Hépatobiliaire, Villejuif, France
- DHU Hepatinov, Villejuif, France
| | - Christian Bréchot
- Inserm, Unité 785, Villejuif, F-94800, France
- Univ Paris-Sud, UMR-S 785, Villejuif, F-94800, France
- Institut Pasteur, Paris, France
| | - Marie-Françoise Bourgeade
- Inserm, Unité 785, Villejuif, F-94800, France
- Univ Paris-Sud, UMR-S 785, Villejuif, F-94800, France
- AP-HP Hôpital Paul Brousse, Centre Hépatobiliaire, Villejuif, France
- DHU Hepatinov, Villejuif, France
- * E-mail:
| | - Catherine Guettier
- Inserm, Unité 785, Villejuif, F-94800, France
- Univ Paris-Sud, UMR-S 785, Villejuif, F-94800, France
- AP-HP Hôpital Kremlin-Bicêtre, Service d’Anatomopathologie, Paris, France
- DHU Hepatinov, Villejuif, France
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99950
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Yang H, Peng YF, Ni HM, Li Y, Shi YH, Ding WX, Fan J. Basal Autophagy and Feedback Activation of Akt Are Associated with Resistance to Metformin-Induced Inhibition of Hepatic Tumor Cell Growth. PLoS One 2015; 10:e0130953. [PMID: 26111001 PMCID: PMC4482411 DOI: 10.1371/journal.pone.0130953] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 05/27/2015] [Indexed: 11/18/2022] Open
Abstract
While accumulating evidence has shown that the use of the diabetic drug metformin may be beneficial against various tumors in some epidemiological studies, a few studies failed to show the same beneficial effects. The molecular and cellular mechanisms for these conflicting observations are not clear. In this study, we compared the inhibitory effects of cell growth by metformin on several hepatic tumor cell lines: SMMC-7721, HCC-97L, HCC-LM3 and HepG2. While metformin inhibited cell growth in all these cells, we found that SMMC-7721, HCC-97L and HCC-LM3 cells were more resistant than HepG2 cells. Mechanistically, we found that metformin inhibited mTOR in all these hepatic tumor cells. However, SMMC-7721 cells had higher levels of basal autophagy and mTORC2-mediated feedback activation of Akt than HepG2 cells, which may render SMMC-7721 cells to be more resistant to metformin-induced inhibition of cell growth. Similarly, HCC-97L and HCC-LM3 cells also had higher feedback activation of AKT than HepG2 cells, which may also account for their resistance to metformin-induced inhibition of cell growth. Therefore, the various basal autophagy and mTOR activity in different cancer cells may contribute to the controversial findings on the use of metformin in inhibition of cancers in humans.
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Affiliation(s)
- Hua Yang
- Liver Cancer Institute, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, Kansas, 66160, United States of America
| | - Yuan-Fei Peng
- Liver Cancer Institute, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Hong-Min Ni
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, Kansas, 66160, United States of America
| | - Yuan Li
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, Kansas, 66160, United States of America
| | - Ying-Hong Shi
- Liver Cancer Institute, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Wen-Xing Ding
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, Kansas, 66160, United States of America
- * E-mail: (WXD); (JF)
| | - Jia Fan
- Liver Cancer Institute, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
- * E-mail: (WXD); (JF)
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