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Sotthibundhu A, Muangchan P, Phonchai R, Promjantuek W, Chaicharoenaudomrung N, Kunhorm P, Noisa P. Autophagy Promoted Neural Differentiation of Human Placenta-derived Mesenchymal Stem Cells. In Vivo 2021; 35:2609-2620. [PMID: 34410948 DOI: 10.21873/invivo.12543] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 05/30/2021] [Accepted: 06/01/2021] [Indexed: 01/03/2023]
Abstract
BACKGROUND/AIM Human placenta-derived mesenchymal stem cells (hPMSCs) are multipotent and possess neurogenicity. Numerous studies have shown that Notch inhibition and DNA demethylation promote neural differentiation. Here, we investigated the modulation of autophagy during neural differentiation of hPMSCs, induced by DAPT and 5-Azacytidine. MATERIALS AND METHODS hPMSCs were treated with DAPT to induce neural differentiation, and the autophagy regulating molecules were used to assess the impact of autophagy on neural differentiation. RESULTS The hPMSCs presented with typical mesenchymal stem cell phenotypes, in which the majority of cells expressed CD73, CD90 and CD105. hPMSCs were multipotent, capable of differentiating into mesodermal cells. After treatment with DAPT, hPMSCs upregulated the expression of neuronal genes including SOX2, Nestin, and βIII-tubulin, and the autophagy genes LC3I/II and Beclin. These genes were further increased when 5-Azacytidine was co-supplemented in the culture medium. The inhibition of autophagy by chloroquine impeded the neural differentiation of hPMSCs, marked by the downregulation of βIII-tubulin, while the activation of autophagy by valproic acid (VPA) instigated the emergence of βIII-tubulin-positive cells. CONCLUSION During the differentiation process, autophagy was modulated, implying that autophagy could play a significant role during the differentiation of these cells. The blockage and stimulation of autophagy could either hinder or induce the formation of neural-like cells, respectively. Therefore, the refinement of autophagic activity at an appropriate level might improve the efficiency of stem cell differentiation.
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Affiliation(s)
- Areechun Sotthibundhu
- Chulabhorn International College of Medicine, Thammasat University, Pathum Thani, Thailand
| | - Pattamon Muangchan
- Laboratory of Cell-Based Assays and Innovations, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, Nakhon Ratchasima, Thailand
| | - Ruchee Phonchai
- Laboratory of Cell-Based Assays and Innovations, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, Nakhon Ratchasima, Thailand
| | - Wilasinee Promjantuek
- Laboratory of Cell-Based Assays and Innovations, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, Nakhon Ratchasima, Thailand
| | - Nipha Chaicharoenaudomrung
- Laboratory of Cell-Based Assays and Innovations, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, Nakhon Ratchasima, Thailand
| | - Phongsakorn Kunhorm
- Laboratory of Cell-Based Assays and Innovations, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, Nakhon Ratchasima, Thailand
| | - Parinya Noisa
- Laboratory of Cell-Based Assays and Innovations, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, Nakhon Ratchasima, Thailand
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Elevated CDK5R1 predicts worse prognosis in hepatocellular carcinoma based on TCGA data. Biosci Rep 2021; 41:227408. [PMID: 33346796 PMCID: PMC7791553 DOI: 10.1042/bsr20203594] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 12/15/2020] [Accepted: 12/15/2020] [Indexed: 12/13/2022] Open
Abstract
Background: Hepatocellular carcinoma (HCC) is a malignant tumor with rapid progression, high recurrence rate and poor prognosis. The objective of our investigation was to explore the prognostic value of CDK5R1 in HCC. Methods: The raw data of HCC raw data were downloaded from The Cancer Genome Atlas (TCGA) database. The Wilcoxon signed-rank test, Kruskal–Wallis test and logistic regression were applied to investigate the relevance between the CDK5R1 expression and clinicopathologic characteristics in HCC. Kaplan–Meier and Cox regression analysis were employed to examine the association between clinicopathologic features and survival. Gene set enrichment analysis (GSEA) was applied to annotate the biological function of CDK5R1. Results: CDK5R1 was highly expressed in HCC tissues. The high expression of CDK5R1 in HCC tissues was significantly associated with tumor status (P=0.00), new tumor event (P=0.00), clinical stage (P=0.00) and topography (P=0.00). Elevated CDK5R1 had significant correlation with worse overall survival (OS; P=7.414e−04), disease-specific survival (DSS; P=5.642e−04), disease-free interval (DFI; P=1.785e−05) and progression-free interval (PFI; P=2.512e−06). Besides, univariate and multivariate Cox regression analysis uncovered that increased CDK5R1 can independently predict adverse OS (P=0.037, hazard ratio [HR]= 1.7 (95% CI [1.0–2.7])), DFI (P=0.007, hazard ratio [HR]= 3.0 (95% CI [1.4–6.7])), PFI (P=0.007, hazard ratio [HR]= 2.8 (95% CI [1.3–5.9])). GSEA disclosed that notch signaling pathway and non-small cell lung cancer were prominently enriched in CDK5R1 high expression phenotype. Conclusions: Increased CDK5R1 may act as a promising independent prognostic factor of poor survival in HCC.
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Kanungo J, Goswami MT, Pant HC. Notch and Cdk5 in Zebrafish Mindbomb Mutant: Co-regulation or Coincidence? Folia Biol (Praha) 2018; 64:35-40. [PMID: 30338754 PMCID: PMC6196738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Notch signalling is critical for the development of the nervous system. In the zebrafish mindbomb mutants, disruption of E3 ubiquitin ligase activity inhibits Notch signalling. In these mutant embryos, precocious development of primary neurons leading to depletion of neural progenitor cells results in a neurogenic phenotype characterized by defects in neural patterning and brain development. Cyclin-dependent kinase 5 (Cdk5), a predominant neuronal kinase, is involved in a variety of essential functions of the nervous system. Most recently, mammalian studies on Notch and Cdk5 regulating each other's function have been emerging. The status of Cdk5 in the mindbomb mutant embryos with excessive primary neurons is not known. In situ hybridization of the zebrafish mindbomb mutant embryos uncovered a robust upregulation in Cdk5 expression but with a reduced Cdk5 activity. The implications of these findings in both the mammalian system and zebrafish are discussed in this mini-review to provide a glimpse into the relationship between Notch and Cdk5 that may explain certain neurodevelopmental defects associated with either mutations in ubiquitin ligase or altered expression of Cdk5.
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Affiliation(s)
- J Kanungo
- Division of Neurotoxicology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, AR, USA
- National Institute of Neuronal Disorders and Stroke, National Institute of Health, Bethesda, MD, USA
| | - M T Goswami
- National Institute of Children's Health and Development, National Institute of Health, Bethesda, MD, USA
| | - H C Pant
- National Institute of Neuronal Disorders and Stroke, National Institute of Health, Bethesda, MD, USA
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Stanga S, Vrancx C, Tasiaux B, Marinangeli C, Karlström H, Kienlen-Campard P. Specificity of presenilin-1- and presenilin-2-dependent γ-secretases towards substrate processing. J Cell Mol Med 2017; 22:823-833. [PMID: 28994238 PMCID: PMC5783875 DOI: 10.1111/jcmm.13364] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 07/27/2017] [Indexed: 12/20/2022] Open
Abstract
The two presenilin‐1 (PS1) and presenilin‐2 (PS2) homologs are the catalytic core of the γ‐secretase complex, which has a major role in cell fate decision and Alzheimer's disease (AD) progression. Understanding the precise contribution of PS1‐ and PS2‐dependent γ‐secretases to the production of β‐amyloid peptide (Aβ) from amyloid precursor protein (APP) remains an important challenge to design molecules efficiently modulating Aβ release without affecting the processing of other γ‐secretase substrates. To that end, we studied PS1‐ and PS2‐dependent substrate processing in murine cells lacking presenilins (PSs) (PS1KO, PS2KO or PS1‐PS2 double‐KO noted PSdKO) or stably re‐expressing human PS1 or PS2 in an endogenous PS‐null (PSdKO) background. We characterized the processing of APP and Notch on both endogenous and exogenous substrates, and we investigated the effect of pharmacological inhibitors targeting the PSs activity (DAPT and L‐685,458). We found that murine PS1 γ‐secretase plays a predominant role in APP and Notch processing when compared to murine PS2 γ‐secretase. The inhibitors blocked more efficiently murine PS2‐ than murine PS1‐dependent processing. Human PSs, especially human PS1, expression in a PS‐null background efficiently restored APP and Notch processing. Strikingly, and contrary to the results obtained on murine PSs, pharmacological inhibitors appear to preferentially target human PS1‐ than human PS2‐dependent γ‐secretase activity.
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Affiliation(s)
- Serena Stanga
- Alzheimer Research group, Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium
| | - Céline Vrancx
- Alzheimer Research group, Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium
| | - Bernadette Tasiaux
- Alzheimer Research group, Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium
| | - Claudia Marinangeli
- Inserm, CHU Lille, UMR-S 1172 - JPArc - Centre de Recherche Jean-Pierre AUBERT, University of Lille, Lille, France
| | - Helena Karlström
- Center for Alzheimer Research, Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institute, Stockholm, Sweden
| | - Pascal Kienlen-Campard
- Alzheimer Research group, Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium
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Borghetti G, Eisenberg CA, Signore S, Sorrentino A, Kaur K, Andrade-Vicenty A, Edwards JG, Nerkar M, Qanud K, Sun D, Goichberg P, Leri A, Anversa P, Eisenberg LM, Jacobson JT, Hintze TH, Rota M. Notch signaling modulates the electrical behavior of cardiomyocytes. Am J Physiol Heart Circ Physiol 2017; 314:H68-H81. [PMID: 28939651 DOI: 10.1152/ajpheart.00587.2016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Notch receptor signaling is active during cardiac development and silenced in myocytes after birth. Conversely, outward K+ Kv currents progressively appear in postnatal myocytes leading to shortening of the action potential (AP) and acquisition of the mature electrical phenotype. In the present study, we tested the possibility that Notch signaling modulates the electrical behavior of cardiomyocytes by interfering with Kv currents. For this purpose, the effects of Notch receptor activity on electrophysiological properties of myocytes were evaluated using transgenic mice with inducible expression of the Notch1 intracellular domain (NICD), the functional fragment of the activated Notch receptor, and in neonatal myocytes after inhibition of the Notch transduction pathway. By patch clamp, NICD-overexpressing cells presented prolonged AP duration and reduced upstroke amplitude, properties that were coupled with reduced rapidly activating Kv and fast Na+ currents, compared with cells obtained from wild-type mice. In cultured neonatal myocytes, inhibition of the proteolitic release of NICD with a γ-secretase antagonist increased transcript levels of the Kv channel-interacting proteins 2 (KChIP2) and enhanced the density of Kv currents. Collectively, these results indicate that Notch signaling represents an important regulator of the electrophysiological behavior of developing and adult myocytes by repressing, at least in part, repolarizing Kv currents. NEW & NOTEWORTHY We investigated the effects of Notch receptor signaling on the electrical properties of cardiomyocytes. Our results indicate that the Notch transduction pathway interferes with outward K+ Kv currents, critical determinants of the electrical repolarization of myocytes.
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Affiliation(s)
- Giulia Borghetti
- Departments of Anesthesia and Medicine, and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School , Boston, Massachusetts
| | - Carol A Eisenberg
- Department of Physiology, New York Medical College, Valhalla, New York
| | - Sergio Signore
- Departments of Anesthesia and Medicine, and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School , Boston, Massachusetts
| | - Andrea Sorrentino
- Departments of Anesthesia and Medicine, and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School , Boston, Massachusetts
| | - Keerat Kaur
- Department of Physiology, New York Medical College, Valhalla, New York
| | | | - John G Edwards
- Department of Physiology, New York Medical College, Valhalla, New York
| | - Mriganka Nerkar
- Department of Physiology, New York Medical College, Valhalla, New York
| | - Khaled Qanud
- Department of Physiology, New York Medical College, Valhalla, New York
| | - Dong Sun
- Department of Physiology, New York Medical College, Valhalla, New York
| | - Polina Goichberg
- Departments of Anesthesia and Medicine, and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School , Boston, Massachusetts
| | - Annarosa Leri
- Departments of Anesthesia and Medicine, and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School , Boston, Massachusetts
| | - Piero Anversa
- Departments of Anesthesia and Medicine, and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School , Boston, Massachusetts
| | | | - Jason T Jacobson
- Department of Physiology, New York Medical College, Valhalla, New York.,Department of Cardiology, Westchester Medical Center, Valhalla, New York
| | - Thomas H Hintze
- Department of Physiology, New York Medical College, Valhalla, New York
| | - Marcello Rota
- Department of Physiology, New York Medical College, Valhalla, New York
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Abstract
In this study, we evaluated whether a cross talk between nuclear factor κB (NF-κB) and Notch may take place and contribute to regulate cell morphology and/or neuronal network in primary cortical neurons. We found that lack of p50, either induced acutely by inhibiting p50 nuclear translocation or genetically in p50(-/-) mice, results in cortical neurons characterized by reduced neurite branching, loss of varicosities, and Notch1 signaling hyperactivation. The neuronal morphological effects found in p50(-/-) cortical cells were reversed after treatment with the γ-secretase inhibitor DAPT (N-[N-(3,5-difluorophenacetyl)-1-alanyl 1]-S-phenylglycine t-butyl ester) or Notch RNA interference. Together, these data suggested that morphological abnormalities in p50(-/-) cortical neurons were dependent on Notch pathway hyperactivation, with Notch ligand Jagged1 being a major player in mediating such effect. In this line, we demonstrated that the p50 subunit acts as transcriptional repressor of Jagged1. We also found altered distribution of Notch1 and Jagged1 immunoreactivity in the cortex of p50(-/-) mice compared with wild-type littermates at postnatal day 1. These data suggest the relevance of future studies on the role of Notch/NF-κB cross talk in regulating cortex structural plasticity in physiological and pathological conditions.
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Chi X, Amet T, Byrd D, Chang KH, Shah K, Hu N, Grantham A, Hu S, Duan J, Tao F, Nicol G, Yu Q. Direct effects of HIV-1 Tat on excitability and survival of primary dorsal root ganglion neurons: possible contribution to HIV-1-associated pain. PLoS One 2011; 6:e24412. [PMID: 21912693 PMCID: PMC3166319 DOI: 10.1371/journal.pone.0024412] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Accepted: 08/10/2011] [Indexed: 11/18/2022] Open
Abstract
The vast majority of people living with human immunodeficiency virus type 1 (HIV-1) have pain syndrome, which has a significant impact on their quality of life. The underlying causes of HIV-1-associated pain are not likely attributable to direct viral infection of the nervous system due to the lack of evidence of neuronal infection by HIV-1. However, HIV-1 proteins are possibly involved as they have been implicated in neuronal damage and death. The current study assesses the direct effects of HIV-1 Tat, one of potent neurotoxic viral proteins released from HIV-1-infected cells, on the excitability and survival of rat primary dorsal root ganglion (DRG) neurons. We demonstrated that HIV-1 Tat triggered rapid and sustained enhancement of the excitability of small-diameter rat primary DRG neurons, which was accompanied by marked reductions in the rheobase and resting membrane potential (RMP), and an increase in the resistance at threshold (R(Th)). Such Tat-induced DRG hyperexcitability may be a consequence of the inhibition of cyclin-dependent kinase 5 (Cdk5) activity. Tat rapidly inhibited Cdk5 kinase activity and mRNA production, and roscovitine, a well-known Cdk5 inhibitor, induced a very similar pattern of DRG hyperexcitability. Indeed, pre-application of Tat prevented roscovitine from having additional effects on the RMP and action potentials (APs) of DRGs. However, Tat-mediated actions on the rheobase and R(Th) were accelerated by roscovitine. These results suggest that Tat-mediated changes in DRG excitability are partly facilitated by Cdk5 inhibition. In addition, Cdk5 is most abundant in DRG neurons and participates in the regulation of pain signaling. We also demonstrated that HIV-1 Tat markedly induced apoptosis of primary DRG neurons after exposure for longer than 48 h. Together, this work indicates that HIV-1 proteins are capable of producing pain signaling through direct actions on excitability and survival of sensory neurons.
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Affiliation(s)
- Xianxun Chi
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Tohti Amet
- Center for AIDS Research and Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Daniel Byrd
- Center for AIDS Research and Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Kuei-Hua Chang
- Department of Chemistry and Purdue University Center for Cancer Research, Purdue University, West Lafayette, Indiana, United States of America
| | - Kavita Shah
- Department of Chemistry and Purdue University Center for Cancer Research, Purdue University, West Lafayette, Indiana, United States of America
| | - Ningjie Hu
- Center for AIDS Research and Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Ayslinn Grantham
- Center for AIDS Research and Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Sishun Hu
- Center for AIDS Research and Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Jianhong Duan
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Feng Tao
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Grant Nicol
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Qigui Yu
- Center for AIDS Research and Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
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Friedrich BM, Murray JL, Li G, Sheng J, Hodge TW, Rubin DH, O'Brien WA, Ferguson MR. A functional role for ADAM10 in human immunodeficiency virus type-1 replication. Retrovirology 2011; 8:32. [PMID: 21569301 PMCID: PMC3118345 DOI: 10.1186/1742-4690-8-32] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2010] [Accepted: 05/11/2011] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Gene trap insertional mutagenesis was used as a high-throughput approach to discover cellular genes participating in viral infection by screening libraries of cells selected for survival from lytic infection with a variety of viruses. Cells harboring a disrupted ADAM10 (A Disintegrin and Metalloprotease 10) allele survived reovirus infection, and subsequently ADAM10 was shown by RNA interference to be important for replication of HIV-1. RESULTS Silencing ADAM10 expression with small interfering RNA (siRNA) 48 hours before infection significantly inhibited HIV-1 replication in primary human monocyte-derived macrophages and in CD4⁺ cell lines. In agreement, ADAM10 over-expression significantly increased HIV-1 replication. ADAM10 down-regulation did not inhibit viral reverse transcription, indicating that viral entry and uncoating are also independent of ADAM10 expression. Integration of HIV-1 cDNA was reduced in ADAM10 down-regulated cells; however, concomitant 2-LTR circle formation was not detected, suggesting that HIV-1 does not enter the nucleus. Further, ADAM10 silencing inhibited downstream reporter gene expression and viral protein translation. Interestingly, we found that while the metalloprotease domain of ADAM10 is not required for HIV-1 replication, ADAM15 and γ-secretase (which proteolytically release the extracellular and intracellular domains of ADAM10 from the plasma membrane, respectively) do support productive infection. CONCLUSIONS We propose that ADAM10 facilitates replication at the level of nuclear trafficking. Collectively, our data support a model whereby ADAM10 is cleaved by ADAM15 and γ-secretase and that the ADAM10 intracellular domain directly facilitates HIV-1 nuclear trafficking. Thus, ADAM10 represents a novel cellular target class for development of antiretroviral drugs.
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Affiliation(s)
- Brian M Friedrich
- Departments of Pathology and Internal Medicine, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555, USA
| | - James L Murray
- Zirus, Inc., 1384 Buford Business Boulevard, Suite 700, Buford, GA, 30518, USA
| | - Guangyu Li
- Departments of Pathology and Internal Medicine, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555, USA
| | - Jinsong Sheng
- Departments of Medicine and Microbiology & Immunology, Vanderbilt University, 1161 21st Ave South, Nashville, TN, 37232, USA
| | - Thomas W Hodge
- Zirus, Inc., 1384 Buford Business Boulevard, Suite 700, Buford, GA, 30518, USA
| | - Donald H Rubin
- Departments of Medicine and Microbiology & Immunology, Vanderbilt University, 1161 21st Ave South, Nashville, TN, 37232, USA
- Research Medicine, VA Tennessee Valley Healthcare System, 1310 24th Ave South, Nashville, TN 37212, USA
| | - William A O'Brien
- Departments of Pathology and Internal Medicine, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555, USA
- Zirus, Inc., 1384 Buford Business Boulevard, Suite 700, Buford, GA, 30518, USA
- Department of Medicine, Division of Infectious Diseases, Emory University School of Medicine, 201 Dowman Dr., Atlanta, GA, 30322, USA
| | - Monique R Ferguson
- Departments of Pathology and Internal Medicine, University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555, USA
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Perruisseau-Carrier C, Jurga M, Forraz N, McGuckin CP. miRNAs stem cell reprogramming for neuronal induction and differentiation. Mol Neurobiol 2011; 43:215-27. [PMID: 21541853 DOI: 10.1007/s12035-011-8179-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Accepted: 03/10/2011] [Indexed: 12/15/2022]
Abstract
Mimicking the natural brain environment during neurogenesis represents the main challenge for efficient in vitro neuronal differentiation of stem cells. The discovery of miRNAs opens new possibilities in terms of modulation of stem cells lineage commitment and differentiation. Many studies demonstrated that in vitro transient overexpression or inhibition of brain-specific miRNAs in stem cells significantly directed differentiation along neuronal cell lineages. Modulating miRNA expression offers new pathways for post-transcriptional gene regulation and stem cell commitment. Neurotrophins and neuropoietins signaling pathways are the main field of investigation for neuronal commitment, differentiation, and maturation. This review will highlight examples of crosstalk between stem-cell-specific and brain-specific signaling pathways and key miRNA candidates for neuronal commitment. Recent progress on understanding miRNAs genetic networks offers promising prospects for their increasing application in the development of new cellular therapies in humans.
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Affiliation(s)
- Claire Perruisseau-Carrier
- CTI-LYON, Cell Therapy Research Institute, Parc Technologique de Lyon Saint-Priest, Saint-Priest, Lyon, France
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Rajagopal C, Stone KL, Mains RE, Eipper BA. Secretion stimulates intramembrane proteolysis of a secretory granule membrane enzyme. J Biol Chem 2010; 285:34632-42. [PMID: 20817724 DOI: 10.1074/jbc.m110.145334] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Regulated intramembrane proteolysis, a highly conserved process employed by diverse regulatory pathways, can release soluble fragments that directly or indirectly modulate gene expression. In this study we used pharmacological tools to identify peptidylglycine α-amidating monooxygenase (PAM), a type I secretory granule membrane protein, as a γ-secretase substrate. PAM, an essential enzyme, catalyzes the final step in the synthesis of the majority of neuropeptides that control metabolic homeostasis. Mass spectroscopy was most consistent with the presence of multiple closely spaced NH(2) termini, suggesting that cleavage occurred near the middle of the PAM transmembrane domain. The luminal domains of PAM must undergo a series of prohormone convertase or α-secretase-mediated cleavages before the remaining transmembrane domain/cytosolic domain fragment can undergo a γ-secretase-like cleavage. Cleavage by γ-secretase generates a soluble fragment of the cytosolic domain (sf-CD) that is known to localize to the nucleus. Although PAM sf-CD is unstable in AtT-20 corticotroph tumor cells, it is readily detected in primary rat anterior pituitary cells. PAM isoform expression, which is tissue-specific and developmentally regulated, affects the efficiency with which sf-CD is produced. sf-CD levels are also modulated by the phosphorylation status of the cytosolic domain and by the ability of the cytosolic domain to interact with cytosolic proteins. sf-CD is produced by primary rat anterior pituitary cells in response to secretogogue, suggesting that sf-CD acts as a signaling molecule relaying information about secretion from the secretory granule to the nucleus.
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Affiliation(s)
- Chitra Rajagopal
- Departments of Molecular, Microbial, and Structural Biology, University of Connecticut Health Center, Farmington, Connecticut 06030, USA
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Saravanamuthu SS, Gao CY, Zelenka PS. Notch signaling is required for lateral induction of Jagged1 during FGF-induced lens fiber differentiation. Dev Biol 2009; 332:166-76. [PMID: 19481073 DOI: 10.1016/j.ydbio.2009.05.566] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2009] [Revised: 05/19/2009] [Accepted: 05/20/2009] [Indexed: 01/08/2023]
Abstract
Previous studies of the developing lens have shown that Notch signaling regulates differentiation of lens fiber cells by maintaining a proliferating precursor pool in the anterior epithelium. However, whether Notch signaling is further required after the onset of fiber cell differentiation is not clear. This work investigates the role of Notch2 and Jagged1 (Jag1) in secondary fiber cell differentiation using rat lens epithelial explants undergoing FGF-2 dependent differentiation in vitro. FGF induced Jag1 expression and Notch2 signaling (as judged by the appearance of activated Notch2 Intracellular Domain (N2ICD)) within 12-24 h. These changes were correlated with induction of the Notch effector, Hes5, upregulation of N-cadherin (N-cad), and downregulation of E-cadherin (E-cad), a cadherin switch characteristic of fiber cell differentiation. Induction of Jag1 was efficiently blocked by U0126, a specific inhibitor of MAPK/ERK signaling, indicating a requirement for signaling through this pathway downstream of the FGF receptor. Other growth factors that activate MAPK/ERK signaling (EGF, PDGF, IGF) did not induce Jag1. Inhibition of Notch signaling using gamma secretase inhibitors DAPT and L-685,458 or anti-Jag1 antibody markedly decreased FGF-dependent expression of Jag1 demonstrating Notch-dependent lateral induction. In addition, inhibition of Notch signaling reduced expression of N-cad, and the cyclin dependent kinase inhibitor, p57Kip2, indicating a direct role for Notch signaling in secondary fiber cell differentiation. These results demonstrate that Notch-mediated lateral induction of Jag1 is an essential component of FGF-dependent lens fiber cell differentiation.
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Affiliation(s)
- Senthil S Saravanamuthu
- Laboratory of Molecular and Developmental Biology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Abstract
Cyclin-dependent kinase 5 (cdk5) is a proline-directed serine/threonine kinase that is activated mostly by association with its activators, p35 and p39. Initially projected as a neuron-specific kinase, cdk5 is expressed ubiquitously and its kinase activity solely depends on the presence of its activators, which are also found in some non-neuronal tissues. As a multifunctional protein, cdk5 has been linked to axonogenesis, cell migration, exocytosis, neuronal differentiation and apoptosis. Cdk5 plays a critical role in functions other than normal physiology, especially in neurodegeneration. Its contribution to both normal physiological as well as pathological processes is mediated by its specific substrates. Cdk5-null mice are embryonically lethal, therefore making it difficult to study precisely what cdk5 does to the nervous system at early stages of development, be it neuron development or programmed cell death. Zebrafish model system bypasses the impediment, as it is amenable to reverse genetics studies. One of the functions that we have followed for the cdk5 ortholog in zebrafish in vivo is its effect on the Rohon-Beard (RB) neurons. RB neurons are the primary sensory spinal neurons that die during the first two days of zebrafish development eventually to be replaced by the dorsal root ganglia (DRG). Based on ours studies and others', here we discuss possible mechanisms that may be involved in cdk5's role in RB neuron development and survival.
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