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Zhang Y, Wang Q, Xue H, Guo Y, Wei S, Li F, Gong L, Pan W, Jiang P. Epigenetic Regulation of Autophagy in Bone Metabolism. FUNCTION 2024; 5:zqae004. [PMID: 38486976 PMCID: PMC10935486 DOI: 10.1093/function/zqae004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 01/18/2024] [Accepted: 01/24/2024] [Indexed: 03/17/2024] Open
Abstract
The skeletal system is crucial for supporting bodily functions, protecting vital organs, facilitating hematopoiesis, and storing essential minerals. Skeletal homeostasis, which includes aspects such as bone density, structural integrity, and regenerative processes, is essential for normal skeletal function. Autophagy, an intricate intracellular mechanism for degrading and recycling cellular components, plays a multifaceted role in bone metabolism. It involves sequestering cellular waste, damaged proteins, and organelles within autophagosomes, which are then degraded and recycled. Autophagy's impact on bone health varies depending on factors such as regulation, cell type, environmental cues, and physiological context. Despite being traditionally considered a cytoplasmic process, autophagy is subject to transcriptional and epigenetic regulation within the nucleus. However, the precise influence of epigenetic regulation, including DNA methylation, histone modifications, and non-coding RNA expression, on cellular fate remains incompletely understood. The interplay between autophagy and epigenetic modifications adds complexity to bone cell regulation. This article provides an in-depth exploration of the intricate interplay between these two regulatory paradigms, with a focus on the epigenetic control of autophagy in bone metabolism. Such an understanding enhances our knowledge of bone metabolism-related disorders and offers insights for the development of targeted therapeutic strategies.
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Affiliation(s)
- Yazhou Zhang
- Department of Foot and Ankle Surgery, Tengzhou Central People’s Hospital, Tengzhou 277500, China
| | - Qianqian Wang
- Department of Pediatric Intensive Care Unit, Tengzhou Central People’s Hospital, Tengzhou 277500, China
| | - Hongjia Xue
- Department of Computer Science, University College London, London, WC1E 6BT, UK
| | - Yujin Guo
- Institute of Clinical Pharmacy & Pharmacology, Jining First People’s Hospital, Jining 272000, China
| | - Shanshan Wei
- Department of Pharmacy, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan 250000, China
- Department of Graduate, Shandong Academy of Medical Sciences, Shandong First Medical University, Jinan 250000, China
| | - Fengfeng Li
- Department of Neurosurgery, Tengzhou Central People’s Hospital, Tengzhou 277500, China
| | - Linqiang Gong
- Department of Gastroenterology, Tengzhou Central People's Hospital, Tengzhou 277500, China
| | - Weiliang Pan
- Department of Foot and Ankle Surgery, Tengzhou Central People’s Hospital, Tengzhou 277500, China
| | - Pei Jiang
- Translational Pharmaceutical Laboratory, Jining First People’s Hospital, Shandong First Medical University, Jining 272000, China
- Institute of Translational Pharmacy, Jining Medical Research Academy, Jining 272000, China
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Wagh AR, Sulakshane P, Glickman MH. Alzheimer's disease-associated mutant ubiquitin (UBB +1) is secreted through an autophagosome-like vesicle-mediated unconventional pathway. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2023; 1866:194936. [PMID: 37075976 DOI: 10.1016/j.bbagrm.2023.194936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 03/28/2023] [Accepted: 04/13/2023] [Indexed: 04/21/2023]
Abstract
Misfolded protein aggregation at both intracellular and extracellular milieus is thought to be the major etiology of Alzheimer's disease (AD). UBB+1, a frameshift variant of the ubiquitin B gene (UBB) results in a folded ubiquitin domain fused to a flexible unstructured extension. Accumulation of UBB+1 in extracellular plaques in the brains of AD patients undoubtedly suggests a role of the ubiquitin-proteasome system in AD. However, the exact mechanism of extracellular secretion of UBB+1 remains unknown. In an attempt to understand the molecular mechanism of UBB+1 secretion, we performed a survey of secretory pathways and identified the involvement of unconventional autophagosome-mediated UBB+1 secretion. Expression of UBB+1 was sufficient to stimulate LC3B/Atg8 conversion from LC3B-I to LC3B-II, which indicates initiation of the autophagy pathway. Furthermore, deficiency of ATG5 - a key player in autophagosome formation - inhibited UBB+1 secretion. Based on immunofluorescence 3D structured illumination (SIM) microscopy and co-immunoprecipitation, we provide evidence that UBB+1 is associated with the secretory autophagosome marker, SEC22B, while HSP90 possibly acts as a carrier. Using LC-MS/MS and mutagenesis we found that in cells, UBB+1 is ubiquitinated on lysine 11, 29, and 48, however, this ubiquitination does not contribute to its secretion. By contrast, proteasome or lysosome inhibition slightly enhanced secretion. Taken together, this study suggests that by ridding cells of UBB+1, secretory autophagosomes may alleviate the cellular stress associated with UBB+1, yet simultaneously mediate the spreading of a mutant specie with disordered characteristics to the extracellular milieu.
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Affiliation(s)
- Ajay R Wagh
- The Faculty of Biology, Technion Israel Institute of Technology, Haifa 32000, Israel
| | - Prasad Sulakshane
- The Faculty of Biology, Technion Israel Institute of Technology, Haifa 32000, Israel
| | - Michael H Glickman
- The Faculty of Biology, Technion Israel Institute of Technology, Haifa 32000, Israel.
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3
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Biswal MR, Padmanabhan S, Manjithaya R, Prakash MK. Early Bioinformatic Implication of Triacidic Amino Acid Motifs in Autophagy-Dependent Unconventional Secretion of Mammalian Proteins. Front Cell Dev Biol 2022; 10:863825. [PMID: 35646924 PMCID: PMC9136135 DOI: 10.3389/fcell.2022.863825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 04/11/2022] [Indexed: 11/22/2022] Open
Abstract
Several proteins are secreted outside the cell, and in many cases, they may be identified by a characteristic signal peptide. However, more and more studies point to the evidence for an “unconventional” secretion, where proteins without a hitherto unknown signal are secreted, possibly in conditions of starvation. In this work, we analyse a set of 202 RNA binding mammalian proteins, whose unconventional secretion has recently been established. Analysis of these proteins secreted by LC3 mediation, the largest unconventionally secreted dataset to our knowledge, identifies the role of KKX motif as well as triacidic amino acid motif in unconventional secretion, the latter being an extension of the recent implicated diacidic amino acid motif. Further data analysis evolves a hypothesis on the sequence or structural proximity of the triacidic or KKX motifs to the LC3 interacting region, and a phosphorylatable amino acid such as serine as a statistically significant feature among these unconventionally secreted proteins. This hypothesis, although needs to be validated in experiments that challenge the specific details of each of these aspects, appears to be one of the early steps in defining what may be a plausible signal for unconventional protein secretion.
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Affiliation(s)
- Malay Ranjan Biswal
- Computational Biology, Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Bangalore, India
| | - Sreedevi Padmanabhan
- Autophagy Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Bangalore, India
| | - Ravi Manjithaya
- Autophagy Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Bangalore, India
- *Correspondence: Ravi Manjithaya, ; Meher K. Prakash,
| | - Meher K. Prakash
- Computational Biology, Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Bangalore, India
- *Correspondence: Ravi Manjithaya, ; Meher K. Prakash,
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Acid Sphingomyelinase Deficiency: A Clinical and Immunological Perspective. Int J Mol Sci 2021; 22:ijms222312870. [PMID: 34884674 PMCID: PMC8657623 DOI: 10.3390/ijms222312870] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 11/16/2021] [Accepted: 11/25/2021] [Indexed: 02/06/2023] Open
Abstract
Acid sphingomyelinase deficiency (ASMD) is a lysosomal storage disease caused by deficient activity of acid sphingomyelinase (ASM) enzyme, leading to the accumulation of varying degrees of sphingomyelin. Lipid storage leads to foam cell infiltration in tissues, and clinical features including hepatosplenomegaly, pulmonary insufficiency and in some cases central nervous system involvement. ASM enzyme replacement therapy is currently in clinical trial being the first treatment addressing the underlying pathology of the disease. Therefore, presently, it is critical to better comprehend ASMD to improve its diagnose and monitoring. Lung disease, including recurrent pulmonary infections, are common in ASMD patients. Along with lung disease, several immune system alterations have been described both in patients and in ASMD animal models, thus highlighting the role of ASM enzyme in the immune system. In this review, we summarized the pivotal roles of ASM in several immune system cells namely on macrophages, Natural Killer (NK) cells, NKT cells, B cells and T cells. In addition, an overview of diagnose, monitoring and treatment of ASMD is provided highlighting the new enzyme replacement therapy available.
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Kim S, Cho H, Hong SO, Oh SJ, Lee HJ, Cho E, Woo SR, Song JS, Chung JY, Son SW, Yoon SM, Jeon YM, Jeon S, Yee C, Lee KM, Hewitt SM, Kim JH, Song KH, Kim TW. LC3B upregulation by NANOG promotes immune resistance and stem-like property through hyperactivation of EGFR signaling in immune-refractory tumor cells. Autophagy 2021; 17:1978-1997. [PMID: 32762616 PMCID: PMC8386750 DOI: 10.1080/15548627.2020.1805214] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 07/10/2020] [Accepted: 07/14/2020] [Indexed: 12/15/2022] Open
Abstract
Immune selection drives tumor cells to acquire refractory phenotypes. We previously demonstrated that cytotoxic T lymphocyte (CTL)-mediated immune pressure enriches NANOG+ tumor cells with stem-like and immune-refractory properties that make them resistant to CTLs. Here, we report that the emergence of refractory phenotypes is highly associated with an aberrant macroautophagic/autophagic state of the NANOG+ tumor cells and that the autophagic phenotype arises through transcriptional induction of MAP1LC3B/LC3B by NANOG. Furthermore, we found that upregulation of LC3B expression contributes to an increase in EGF secretion. The subsequent hyperactivation of EGFR-AKT signaling rendered NANOG+ tumor cells resistant to CTL killing. The NANOG-LC3B-p-EGFR axis was preserved across various types of human cancer and correlated negatively with the overall survival of cervical cancer patients. Inhibition of LC3B in immune-refractory tumor models rendered tumors susceptible to adoptive T-cell transfer, as well as PDCD1/PD-1 blockade, and led to successful, long-term control of the disease. Thus, our findings demonstrate a novel link among immune-resistance, stem-like phenotypes, and LC3B-mediated autophagic secretion in immune-refractory tumor cells, and implicate the LC3B-p-EGFR axis as a central molecular target for controlling NANOG+ immune-refractory cancer.Abbreviations: ACTB: actin beta; ATG7: autophagy related 7; BafA1: bafilomycin A1; CASP3: caspase 3; CFSE: carboxyfluorescein succinimidyl ester; ChIP: chromatin immunoprecipitation; CI: confidence interval; CIN: cervical intraepithelial neoplasia; CSC: cancer stem cell; CTL: cytotoxic T lymphocyte; EGF: epidermal growth factor; EGFR: epidermal growth factor receptor; FIGO: International Federation of Gynecology and Obstetrics; GFP: green fluorescent protein; GZMB: granzyme B; HG-CIN: high-grade CIN; IHC: immunohistochemistry; LG-CIN: low-grade CIN; LN: lymph node; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MCL1: myeloid cell leukemia sequence 1; MLANA/MART-1: melanoma antigen recognized by T cells 1; MUT: mutant; NANOG: Nanog homeobox; PDCD1/PD-1: programmed cell death 1; PMEL/gp100: premelanosome protein; RTK: receptor tyrosine kinase; TMA: tissue microarray; WT: wild type.
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Affiliation(s)
- Suyeon Kim
- Department of Biochemistry & Molecular Biology, Department of Biomedical Science, Korea University College of Medicine, Seoul, South Korea
- Department of Biomedical Science, Korea University College of Medicine, Seoul, South Korea
| | - Hanbyoul Cho
- Experimental Pathology Laboratory, Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
- Department of Obstetrics and Gynecology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
- Institute of Women’s Life Medical Science, Yonsei University College of Medicine, Seoul, South Korea
| | - Soon-Oh Hong
- Department of Biochemistry & Molecular Biology, Department of Biomedical Science, Korea University College of Medicine, Seoul, South Korea
- Department of Biomedical Science, Korea University College of Medicine, Seoul, South Korea
| | - Se Jin Oh
- Department of Biochemistry & Molecular Biology, Department of Biomedical Science, Korea University College of Medicine, Seoul, South Korea
- Department of Biomedical Science, Korea University College of Medicine, Seoul, South Korea
| | - Hyo-Jung Lee
- Department of Biochemistry & Molecular Biology, Department of Biomedical Science, Korea University College of Medicine, Seoul, South Korea
- Department of Biomedical Science, Korea University College of Medicine, Seoul, South Korea
| | - Eunho Cho
- Department of Biochemistry & Molecular Biology, Department of Biomedical Science, Korea University College of Medicine, Seoul, South Korea
- Department of Biomedical Science, Korea University College of Medicine, Seoul, South Korea
| | - Seon Rang Woo
- Department of Biochemistry & Molecular Biology, Department of Biomedical Science, Korea University College of Medicine, Seoul, South Korea
- Department of Biomedical Science, Korea University College of Medicine, Seoul, South Korea
| | - Joon Seon Song
- Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
| | - Joon-Yong Chung
- Experimental Pathology Laboratory, Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Sung Wook Son
- Department of Biochemistry & Molecular Biology, Department of Biomedical Science, Korea University College of Medicine, Seoul, South Korea
- Department of Biomedical Science, Korea University College of Medicine, Seoul, South Korea
| | - Sang Min Yoon
- Department of Medicine, Korea University College of Medicine, Seoul, South Korea
| | - Yu-Min Jeon
- Department of Medicine, Korea University College of Medicine, Seoul, South Korea
| | - Seunghyun Jeon
- Department of Biochemistry & Molecular Biology, Department of Biomedical Science, Korea University College of Medicine, Seoul, South Korea
- Department of Biomedical Science, Korea University College of Medicine, Seoul, South Korea
| | - Cassian Yee
- Department of Gynecologic Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Kyung-Mi Lee
- Department of Biochemistry & Molecular Biology, Department of Biomedical Science, Korea University College of Medicine, Seoul, South Korea
- Department of Biomedical Science, Korea University College of Medicine, Seoul, South Korea
| | - Stephen M. Hewitt
- Experimental Pathology Laboratory, Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Jae-Hoon Kim
- Department of Obstetrics and Gynecology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
- Institute of Women’s Life Medical Science, Yonsei University College of Medicine, Seoul, South Korea
| | - Kwon-Ho Song
- Department of Biochemistry & Molecular Biology, Department of Biomedical Science, Korea University College of Medicine, Seoul, South Korea
- Department of Biomedical Science, Korea University College of Medicine, Seoul, South Korea
| | - Tae Woo Kim
- Department of Biochemistry & Molecular Biology, Department of Biomedical Science, Korea University College of Medicine, Seoul, South Korea
- Department of Biomedical Science, Korea University College of Medicine, Seoul, South Korea
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6
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Padmanabhan S, Manjithaya R. Facets of Autophagy Based Unconventional Protein Secretion-The Road Less Traveled. Front Mol Biosci 2020; 7:586483. [PMID: 33363205 PMCID: PMC7755989 DOI: 10.3389/fmolb.2020.586483] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 09/07/2020] [Indexed: 12/28/2022] Open
Abstract
Unconventional protein secretion (UCPS) of leaderless proteins bypasses the conventional endoplasmic reticulum (ER)-Golgi route. The proportion of UCPS in the secretome varies tremendously across eukaryotes. Interestingly, macroautophagy, an intracellular recycling process that is generally involved in cargo degradation, also participates in UCPS. This emerging field of secretory mode of autophagy is underexplored and has several unanswered questions regarding the composition of players, cargo, and the mechanisms that drive it. As secretomes vary considerably across cell types and physiological conditions, the contribution of secretory autophagy in healthy and pathophysiological states remain to be elucidated. Recent studies have begun to shed light on this enigmatic process.
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Affiliation(s)
- Sreedevi Padmanabhan
- Autophagy Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, India
| | - Ravi Manjithaya
- Autophagy Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, India.,Neuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, India
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7
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Gebril SM, Ito Y, Abu-Dief EE, Hussein MRA, Elsayed HM, Mohammad AN, Abdelaal UM, Higuchi K. Ultra-structural study of the indomethacin-induced apoptosis and autophagy in rat gastric parietal cells. Ultrastruct Pathol 2020; 44:300-313. [PMID: 32672114 DOI: 10.1080/01913123.2020.1772429] [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] [Indexed: 01/25/2023]
Abstract
BACKGROUND AND AIM OF THE WORK Indomethacin (IND), a non-steroidal anti-inflammatory drug, can induce gastric mucosal ulcerations. To date, the ultra-structural changes in the parietal cells (PCs) of the gastric mucosa following the intake of IND are mostly unknown. We carried out the current investigation to get insights into this issue. MATERIALS AND METHODS We established an animal model consisting of 35 adult male Sprague Dawley rats. The animals were divided into three groups, including; control (normal feeding), fasting, and indomethacin-treated groups. After treatment of 18-h fasting rats with IND, they were sacrificed at 3, 6, and 12-h intervals. The morphological features, including the apoptotic, and autophagic changes in the gastric mucosa PCs were examined using transmission electron microscopy. RESULTS In normal feeding animals (control group), the gastric PCs were present in various stages of activity. Fasting was associated with the predominance of the inactive parietal cells with features of up-regulated autophagy. In the IND -treated animals (at 3-h interval), PCs showed prominent autophagic changes, and subtle apoptotic cell death. In the IND -treated animals (at 6-12-h interval), PCs showed prominent apoptotic changes, and subtle autophagic features. CONCLUSIONS Our study indicates that IND treatment could induce gastropathy through time-dependent alterations in the autophagic and apoptotic machinery of PCs. Further studies are needed to examine the underlying molecular mechanisms.
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Affiliation(s)
- Sahar M Gebril
- Department of Anatomy, and Cell Biology, Osaka Medical College , Takatsuki, Japan.,Department of Histology, Faculty of Medicine, Sohag University , Sohag, Egypt
| | - Yuko Ito
- Department of Anatomy, and Cell Biology, Osaka Medical College , Takatsuki, Japan
| | - Eman E Abu-Dief
- Department of Histology, Faculty of Medicine, Sohag University , Sohag, Egypt
| | | | - Hoda M Elsayed
- Department of Histology, Faculty of Medicine, Sohag University , Sohag, Egypt
| | - Asmaa Naser Mohammad
- Department of Tropical Medicine and Gastroenterology, Sohag University Hospital , Sohag, Egypt
| | - Usama M Abdelaal
- Department of Internal Medicine, Sohag University Hospital , Egypt.,Department of Internal Medicine, Osaka Medical College , Takatsuki, Japan
| | - Kazuhide Higuchi
- Department of Internal Medicine, Osaka Medical College , Takatsuki, Japan
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The GABARAP Co-Secretome Identified by APEX2-GABARAP Proximity Labelling of Extracellular Vesicles. Cells 2020; 9:cells9061468. [PMID: 32560054 PMCID: PMC7349886 DOI: 10.3390/cells9061468] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 06/05/2020] [Accepted: 06/12/2020] [Indexed: 01/07/2023] Open
Abstract
The autophagy-related ATG8 protein GABARAP has not only been shown to be involved in the cellular self-degradation process called autophagy but also fulfils functions in intracellular trafficking processes such as receptor transport to the plasma membrane. Notably, available mass spectrometry data suggest that GABARAP is also secreted into extracellular vesicles (EVs). Here, we confirm this finding by the immunoblotting of EVs isolated from cell culture supernatants and human blood serum using specific anti-GABARAP antibodies. To investigate the mechanism by which GABARAP is secreted, we applied proximity labelling, a method for studying the direct environment of a protein of interest in a confined cellular compartment. By expressing an engineered peroxidase (APEX2)-tagged variant of GABARAP—which, like endogenous GABARAP, was present in EVs prepared from HEK293 cells—we demonstrate the applicability of APEX2-based proximity labelling to EVs. The biotinylated protein pool which contains the APEX2-GABARAP co-secretome contained not only known GABARAP interaction partners but also proteins that were found in APEX2-GABARAP’s proximity inside of autophagosomes in an independent study. All in all, we not only introduce a versatile tool for co-secretome analysis in general but also uncover the first details about autophagy-based pathways as possible biogenesis mechanisms of GABARAP-containing EVs.
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9
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Zhu L, Zang J, Liu B, Yu G, Hao L, Liu L, Zhong J. Oxidative stress-induced RAC autophagy can improve the HUVEC functions by releasing exosomes. J Cell Physiol 2020; 235:7392-7409. [PMID: 32096219 PMCID: PMC7496456 DOI: 10.1002/jcp.29641] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 02/04/2020] [Indexed: 12/20/2022]
Abstract
Retinal neovascularization (RNV) is a common pathological feature in many kinds of fundus oculi diseases. Sometimes RNV can even lead to severe vision loss. Oxidative injury is one of the main predisposing factors for RNV occurrence and development. The specific mechanism may be closely related to the special structural tissues of the retina. Retinal astrocytes (RACs) are mesenchymal cells located in the retinal neuroepithelial layer. RACs have an intimate anatomical relationship with microvascular endothelial cells. They have a variety of functions, but little is known about the mechanisms by which RACs regulate the function of endothelial cells. The molecules secreted by RACs, such as exosomes, have recently received a lot of attention and may provide potential clues to address the RAC‐mediated modulation of endothelial cells. In this study, we aimed to preliminarily explore the mechanisms of how RAC exosomes generated under oxidative stress are involved in the regulation of endothelial function. Our results showed that the apoptosis and autophagy levels in RACs were positively correlated with the oxidative stress level, and the exosomes generated from RACs under normal and oxidative stress conditions had different effects on the proliferation and migration of endothelial cells. However, the effect of RACs on endothelial cell function could be markedly reversed by the autophagy inhibitor 3‐methyladenine or the exosome inhibitor GW4869. Therefore, oxidative stress can lead to increased autophagy in RACs and can further promote RACs to regulate endothelial cell function by releasing exosomes. tBHP‐induced oxidative stress can increase the level of autophagy in retinal (RAC) astrocytes. RAC with high‐autophagy level has a completely opposite effect on HUVEC functions when compared with normal RAC. RACs under different states have different effects on endothelial cell functions by releasing exosomes
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Affiliation(s)
- Linxin Zhu
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Jiankun Zang
- Department of Neurology and Stroke Center, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Bing Liu
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Guocheng Yu
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Lili Hao
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Lian Liu
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Jingxiang Zhong
- Department of Ophthalmology, The First Affiliated Hospital of Jinan University, Guangzhou, China
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10
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Saraste J, Prydz K. A New Look at the Functional Organization of the Golgi Ribbon. Front Cell Dev Biol 2019; 7:171. [PMID: 31497600 PMCID: PMC6713163 DOI: 10.3389/fcell.2019.00171] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 08/07/2019] [Indexed: 12/14/2022] Open
Abstract
A characteristic feature of vertebrate cells is a Golgi ribbon consisting of multiple cisternal stacks connected into a single-copy organelle next to the centrosome. Despite numerous studies, the mechanisms that link the stacks together and the functional significance of ribbon formation remain poorly understood. Nevertheless, these questions are of considerable interest, since there is increasing evidence that Golgi fragmentation – the unlinking of the stacks in the ribbon – is intimately connected not only to normal physiological processes, such as cell division and migration, but also to pathological states, including neurodegeneration and cancer. Challenging a commonly held view that ribbon architecture involves the formation of homotypic tubular bridges between the Golgi stacks, we present an alternative model, based on direct interaction between the biosynthetic (pre-Golgi) and endocytic (post-Golgi) membrane networks and their connection with the centrosome. We propose that the central domains of these permanent pre- and post-Golgi networks function together in the biogenesis and maintenance of the more transient Golgi stacks, and thereby establish “linker compartments” that dynamically join the stacks together. This model provides insight into the reversible fragmentation of the Golgi ribbon that takes place in dividing and migrating cells and its regulation along a cell surface – Golgi – centrosome axis. Moreover, it helps to understand transport pathways that either traverse or bypass the Golgi stacks and the positioning of the Golgi apparatus in differentiated neuronal, epithelial, and muscle cells.
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Affiliation(s)
- Jaakko Saraste
- Department of Biomedicine and Molecular Imaging Center, University of Bergen, Bergen, Norway
| | - Kristian Prydz
- Department of Biosciences, University of Oslo, Oslo, Norway
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11
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Zess EK, Jensen C, Cruz-Mireles N, De la Concepcion JC, Sklenar J, Stephani M, Imre R, Roitinger E, Hughes R, Belhaj K, Mechtler K, Menke FLH, Bozkurt T, Banfield MJ, Kamoun S, Maqbool A, Dagdas YF. N-terminal β-strand underpins biochemical specialization of an ATG8 isoform. PLoS Biol 2019; 17:e3000373. [PMID: 31329577 PMCID: PMC6675122 DOI: 10.1371/journal.pbio.3000373] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 08/01/2019] [Accepted: 07/09/2019] [Indexed: 02/07/2023] Open
Abstract
Autophagy-related protein 8 (ATG8) is a highly conserved ubiquitin-like protein that modulates autophagy pathways by binding autophagic membranes and a number of proteins, including cargo receptors and core autophagy components. Throughout plant evolution, ATG8 has expanded from a single protein in algae to multiple isoforms in higher plants. However, the degree to which ATG8 isoforms have functionally specialized to bind distinct proteins remains unclear. Here, we describe a comprehensive protein-protein interaction resource, obtained using in planta immunoprecipitation (IP) followed by mass spectrometry (MS), to define the potato ATG8 interactome. We discovered that ATG8 isoforms bind distinct sets of plant proteins with varying degrees of overlap. This prompted us to define the biochemical basis of ATG8 specialization by comparing two potato ATG8 isoforms using both in vivo protein interaction assays and in vitro quantitative binding affinity analyses. These experiments revealed that the N-terminal β-strand-and, in particular, a single amino acid polymorphism-underpins binding specificity to the substrate PexRD54 by shaping the hydrophobic pocket that accommodates this protein's ATG8-interacting motif (AIM). Additional proteomics experiments indicated that the N-terminal β-strand shapes the broader ATG8 interactor profiles, defining interaction specificity with about 80 plant proteins. Our findings are consistent with the view that ATG8 isoforms comprise a layer of specificity in the regulation of selective autophagy pathways in plants.
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Affiliation(s)
- Erin K. Zess
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
| | - Cassandra Jensen
- Department of Biological Chemistry, John Innes Centre, Norwich, United Kingdom
| | - Neftaly Cruz-Mireles
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
- Department of Biological Chemistry, John Innes Centre, Norwich, United Kingdom
| | - Juan Carlos De la Concepcion
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
- Department of Biological Chemistry, John Innes Centre, Norwich, United Kingdom
| | - Jan Sklenar
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
| | - Madlen Stephani
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
| | - Richard Imre
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
- Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
- Institute of Molecular Biotechnology, Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
| | - Elisabeth Roitinger
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
- Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
- Institute of Molecular Biotechnology, Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
| | - Richard Hughes
- Department of Biological Chemistry, John Innes Centre, Norwich, United Kingdom
| | - Khaoula Belhaj
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
| | - Karl Mechtler
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
- Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
- Institute of Molecular Biotechnology, Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
| | - Frank L. H. Menke
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
| | - Tolga Bozkurt
- Imperial College London, Department of Life Sciences, London, United Kingdom
| | - Mark J. Banfield
- Department of Biological Chemistry, John Innes Centre, Norwich, United Kingdom
| | - Sophien Kamoun
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
| | - Abbas Maqbool
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
- Department of Biological Chemistry, John Innes Centre, Norwich, United Kingdom
| | - Yasin F. Dagdas
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
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12
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Lonati E, Sala G, Tresoldi V, Coco S, Salerno D, Milani C, Losurdo M, Farina F, Botto L, Ferrarese C, Palestini P, Bulbarelli A. Ischemic Conditions Affect Rerouting of Tau Protein Levels: Evidences for Alteration in Tau Processing and Secretion in Hippocampal Neurons. J Mol Neurosci 2018; 66:604-616. [DOI: 10.1007/s12031-018-1199-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 10/17/2018] [Indexed: 11/30/2022]
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13
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Basmaciyan L, Berry L, Gros J, Azas N, Casanova M. Temporal analysis of the autophagic and apoptotic phenotypes in Leishmania parasites. MICROBIAL CELL 2018; 5:404-417. [PMID: 30280103 PMCID: PMC6167523 DOI: 10.15698/mic2018.09.646] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The leishmaniases are worldwide neglected tropical diseases caused by parasitic protozoa of the Leishmania genus. Different stimuli induce Leishmania cell death, but the proteins involved remain poorly understood. Furthermore, confusion often appears between cell death and the cell survival process autophagy, whose phenotype is not clearly defined. In this article, we present a comprehensive and temporal analysis of the cellular events occurring during miltefosine-induced cell death and autophagy in L. major. We also provide a list of features in order to clearly identify apoptotic cells, autophagic cells and to distinguish both processes. Furthermore, we demonstrate that autophagy is followed by apoptosis in the absence of nutrients. Finally, we show that cells treated with the generic kinase inhibitor staurosporine express apoptotic as well as autophagic markers and therefore cannot be used as an apoptosis inducer in Leishmania. These descriptions lead to a better recognition and understanding of apoptosis and autophagy, enabling their targeting in the development of new anti-leishmanial drugs. These researches also make it possible to better understand these processes in general, through the study of an ancestral eukaryote.
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Affiliation(s)
- Louise Basmaciyan
- UMR PAM A, Valmis team, 2 rue Angélique Ducoudray, BP 37013, 21070 Dijon Cedex, France
| | - Laurence Berry
- Dynamique des Interactions Membranaires Normales et Pathologiques, CNRS UMR 5235, University of Montpellier, France
| | - Julie Gros
- Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, IHU-Méditerranée Infection, Marseille, France
| | - Nadine Azas
- Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, IHU-Méditerranée Infection, Marseille, France
| | - Magali Casanova
- Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, IHU-Méditerranée Infection, Marseille, France
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14
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Olimpio RMC, de Oliveira M, De Sibio MT, Moretto FCF, Deprá IC, Mathias LS, Gonçalves BM, Rodrigues BM, Tilli HP, Coscrato VE, Costa SMB, Mazeto GMFS, Fernandes CJC, Zambuzzi WF, Saraiva PP, Maria DA, Nogueira CR. Cell viability assessed in a reproducible model of human osteoblasts derived from human adipose-derived stem cells. PLoS One 2018; 13:e0194847. [PMID: 29641603 PMCID: PMC5895002 DOI: 10.1371/journal.pone.0194847] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 03/09/2018] [Indexed: 01/04/2023] Open
Abstract
Human adipose tissue-derived stem cells (hASCs) have been subjected to extensive investigation because of their self-renewal properties and potential to restore damaged tissues. In the literature, there are several protocols for differentiating hASCs into osteoblasts, but there is no report on the control of cell viability during this process. In this study, we used osteoblasts derived from hASCs of patients undergoing abdominoplasty. The cells were observed at the beginning and end of bone matrix formation, and the expression of proteins involved in this process, including alkaline phosphatase and osteocalcin, was assessed. RANKL, Osterix, Runx2, Collagen3A1, Osteopontin and BSP expression levels were analyzed using real-time PCR, in addition to a quantitative assessment of protein levels of the markers CD45, CD105, STRO-1, and Nanog, using immunofluorescence. Rhodamine (Rho123), cytochrome-c, caspase-3, P-27, cyclin D1, and autophagy cell markers were analyzed by flow cytometry to demonstrate potential cellular activity and the absence of apoptotic and tumor cell processes before and after cell differentiation. The formation of bone matrix, along with calcium nodules, was observed after 16 days of osteoinduction. The gene expression levels of RANKL, Osterix, Runx2, Collagen3A1, Osteopontin, BSP and alkaline phosphatase activity were also elevated after 16 days of osteoinduction, whereas the level of osteocalcin was higher after 21 days of osteoinduction. Our data also showed that the cells had a high mitochondrial membrane potential and a low expression of apoptotic and tumor markers, both before and after differentiation. Cells were viable after the different phases of differentiation. This proposed methodology, using markers to evaluate cell viability, is therefore successful in assessing different phases of stem cell isolation and differentiation.
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Affiliation(s)
- Regiane M. C. Olimpio
- Department of Internal Medicine, Botucatu Medical School, São Paulo State University - UNESP, Botucatu, São Paulo, Brazil
- * E-mail:
| | - Miriane de Oliveira
- Department of Internal Medicine, Botucatu Medical School, São Paulo State University - UNESP, Botucatu, São Paulo, Brazil
| | - Maria T. De Sibio
- Department of Internal Medicine, Botucatu Medical School, São Paulo State University - UNESP, Botucatu, São Paulo, Brazil
| | - Fernanda C. F. Moretto
- Department of Internal Medicine, Botucatu Medical School, São Paulo State University - UNESP, Botucatu, São Paulo, Brazil
| | - Igor C. Deprá
- Department of Internal Medicine, Botucatu Medical School, São Paulo State University - UNESP, Botucatu, São Paulo, Brazil
| | - Lucas S. Mathias
- Department of Internal Medicine, Botucatu Medical School, São Paulo State University - UNESP, Botucatu, São Paulo, Brazil
| | - Bianca M. Gonçalves
- Department of Internal Medicine, Botucatu Medical School, São Paulo State University - UNESP, Botucatu, São Paulo, Brazil
| | - Bruna M. Rodrigues
- Department of Internal Medicine, Botucatu Medical School, São Paulo State University - UNESP, Botucatu, São Paulo, Brazil
| | - Helena P. Tilli
- Department of Internal Medicine, Botucatu Medical School, São Paulo State University - UNESP, Botucatu, São Paulo, Brazil
| | - Virgínia E. Coscrato
- Department of Internal Medicine, Botucatu Medical School, São Paulo State University - UNESP, Botucatu, São Paulo, Brazil
| | - Sarah M. B. Costa
- Department of Internal Medicine, Botucatu Medical School, São Paulo State University - UNESP, Botucatu, São Paulo, Brazil
| | - Gláucia M. F. S. Mazeto
- Department of Internal Medicine, Botucatu Medical School, São Paulo State University - UNESP, Botucatu, São Paulo, Brazil
| | - Célio J. C. Fernandes
- Institute of Biosciences, Department of Chemistry and Biochemistry, São Paulo State University - UNESP, Botucatu, São Paulo, Brazil
| | - Willian F. Zambuzzi
- Institute of Biosciences, Department of Chemistry and Biochemistry, São Paulo State University - UNESP, Botucatu, São Paulo, Brazil
| | - Patrícia P. Saraiva
- Department of Internal Medicine, Botucatu Medical School, São Paulo State University - UNESP, Botucatu, São Paulo, Brazil
| | - Durvanei A. Maria
- Biochemistry and Biophysics Laboratory, Butantan Institute, São Paulo, São Paulo, Brazil
| | - Célia R. Nogueira
- Department of Internal Medicine, Botucatu Medical School, São Paulo State University - UNESP, Botucatu, São Paulo, Brazil
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15
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Shao G, Wang R, Sun A, Wei J, Peng K, Dai Q, Yang W, Lin Q. The E3 ubiquitin ligase NEDD4 mediates cell migration signaling of EGFR in lung cancer cells. Mol Cancer 2018; 17:24. [PMID: 29455656 PMCID: PMC5817799 DOI: 10.1186/s12943-018-0784-2] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 02/01/2018] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND EGFR-dependent cell migration plays an important role in lung cancer progression. Our previous study observed that the HECT E3 ubiquitin ligase NEDD4 is significantly correlated with tumor metastasis and required for migration and invasion signaling of EGFR in gastric cancer cells. However, how NEDD4 promotes the EGFR-dependent lung cancer cell migration is unknown. This study is to elucidate the mechanism by which NEDD4 mediates the EGFR lung cancer migration signaling. METHODS Lentiviral vector-loaded NEDD4 shRNA was used to deplete endogenous NEDD4 in lung cancer cell lines. Effects of the NEDD4 knockdown on the EGFR-dependent or independent lung cancer cell migration were determined using the wound-healing and transwell assays. Association of NEDD4 with activated EGFR was assayed by co-immunoprecipitation. Co-expression of NEDD4 with EGFR or PTEN was determined by immunohistochemical (IHC) staining in 63 lung adenocarcinoma tissue samples. Effects of NEDD4 ectopic expression or knockdown on PTEN ubiquitination and down-regulation, AKT activation and lysosomal secretion were examined using the GST-Uba pulldown assay, immunoblotting, immunofluorescent staining and a human cathepsin B ELISA assay respectively. The specific cathepsin B inhibitor CA-074Me was used for assessing the role of cathepsin B in lung cancer cell migration. RESULTS Knockdown of NEDD4 significantly reduced EGF-stimulated cell migration in non-small cell lung carcinoma (NSCLC) cells. Co-immunoprecipitation assay found that NEDD4 is associated with EGFR complex upon EGF stimulation, and IHC staining indicates that NEDD4 is co-expressed with EGFR in lung adenocarcinoma tumor tissues, suggesting that NEDD4 might mediate lung cancer cell migration by interaction with the EGFR signaling complex. Interestingly, NEDD4 promotes the EGF-induced cathepsin B secretion, possibly through lysosomal exocytosis, as overexpression of the ligase-dead mutant of NEDD4 impedes lysosomal secretion, and knockdown of NEDD4 significantly reduced extracellular amount of cathepsin B induced by EGF. Consistent with the role of NEDD4, cathepsin B is pivotal for both basal and the EGF-stimulated lung cancer cell migration. Our studies propose a novel mechanism underlying the EGFR-promoted lung cancer cell migration that is mediated by NEDD4 through regulation of cathepsin B secretion. CONCLUSION NEDD4 mediates the EGFR lung cancer cell migration signaling through promoting lysosomal secretion of cathepsin B.
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Affiliation(s)
- Genbao Shao
- School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, 212013, China
| | - Ranran Wang
- School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, 212013, China
| | - Aiqin Sun
- School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, 212013, China
| | - Jing Wei
- School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, 212013, China
| | - Ke Peng
- School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, 212013, China
| | - Qian Dai
- School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, 212013, China
| | - Wannian Yang
- School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, 212013, China
| | - Qiong Lin
- School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, 212013, China.
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16
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Abstract
All eukaryotic cells secrete a range of proteins in a constitutive or regulated manner through the conventional or canonical exocytic/secretory pathway characterized by vesicular traffic from the endoplasmic reticulum, through the Golgi apparatus, and towards the plasma membrane. However, a number of proteins are secreted in an unconventional manner, which are insensitive to inhibitors of conventional exocytosis and use a route that bypasses the Golgi apparatus. These include cytosolic proteins such as fibroblast growth factor 2 (FGF2) and interleukin-1β (IL-1β), and membrane proteins that are known to also traverse to the plasma membrane by a conventional process of exocytosis, such as α integrin and the cystic fibrosis transmembrane conductor (CFTR). Mechanisms underlying unconventional protein secretion (UPS) are actively being analyzed and deciphered, and these range from an unusual form of plasma membrane translocation to vesicular processes involving the generation of exosomes and other extracellular microvesicles. In this chapter, we provide an overview on what is currently known about UPS in animal cells.
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Affiliation(s)
- Fanny Ng
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, Singapore, 117597, Singapore
| | - Bor Luen Tang
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, Singapore, 117597, Singapore.
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, 28 Medical Drive, Singapore, 117456, Singapore.
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17
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Cudjoe EK, Saleh T, Hawkridge AM, Gewirtz DA. Proteomics Insights into Autophagy. Proteomics 2017; 17. [DOI: 10.1002/pmic.201700022] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 08/25/2017] [Indexed: 12/12/2022]
Affiliation(s)
- Emmanuel K. Cudjoe
- Department of Pharmacotherapy & Outcomes Science; Virginia Commonwealth University; Richmond VA
| | - Tareq Saleh
- Department of Pharmacology & Toxicology; Virginia Commonwealth University; Richmond VA
| | - Adam M. Hawkridge
- Department of Pharmacotherapy & Outcomes Science; Virginia Commonwealth University; Richmond VA
- Department of Pharmaceutics; Virginia Commonwealth University; Richmond VA
| | - David A. Gewirtz
- Department of Pharmacology & Toxicology; Virginia Commonwealth University; Richmond VA
- Massey Cancer Center; Virginia Commonwealth University; Richmond VA
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18
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Sanchez-Vera V, Kenchappa CS, Landberg K, Bressendorff S, Schwarzbach S, Martin T, Mundy J, Petersen M, Thelander M, Sundberg E. Autophagy is required for gamete differentiation in the moss Physcomitrella patens. Autophagy 2017; 13:1939-1951. [PMID: 28837383 PMCID: PMC5788497 DOI: 10.1080/15548627.2017.1366406] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 07/17/2017] [Accepted: 08/08/2017] [Indexed: 12/21/2022] Open
Abstract
Autophagy, a major catabolic process in eukaryotes, was initially related to cell tolerance to nutrient depletion. In plants autophagy has also been widely related to tolerance to biotic and abiotic stresses (through the induction or repression of programmed cell death, PCD) as well as to promotion of developmentally regulated PCD, starch degradation or caloric restriction important for life span. Much less is known regarding its role in plant cell differentiation. Here we show that macroautophagy, the autophagy pathway driven by engulfment of cytoplasmic components by autophagosomes and its subsequent degradation in vacuoles, is highly active during germ cell differentiation in the early diverging land plant Physcomitrella patens. Our data provide evidence that suppression of ATG5-mediated autophagy results in reduced density of the egg cell-mediated mucilage that surrounds the mature egg, pointing toward a potential role of autophagy in extracellular mucilage formation. In addition, we found that ATG5- and ATG7-mediated autophagy is essential for the differentiation and cytoplasmic reduction of the flagellated motile sperm and hence for sperm fertility. The similarities between the need of macroautophagy for sperm differentiation in moss and mouse are striking, strongly pointing toward an ancestral function of autophagy not only as a protector against nutrient stress, but also in gamete differentiation.
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Affiliation(s)
- Victoria Sanchez-Vera
- Department of Plant Biology, Swedish University of Agricultural Sciences, The Linnean Centre of Plant Biology in Uppsala, Uppsala, Sweden
| | - Chandra Shekar Kenchappa
- Department of Plant Biology, Swedish University of Agricultural Sciences, The Linnean Centre of Plant Biology in Uppsala, Uppsala, Sweden
| | - Katarina Landberg
- Department of Plant Biology, Swedish University of Agricultural Sciences, The Linnean Centre of Plant Biology in Uppsala, Uppsala, Sweden
| | | | - Stefan Schwarzbach
- Department of Plant Biology, Swedish University of Agricultural Sciences, The Linnean Centre of Plant Biology in Uppsala, Uppsala, Sweden
| | - Tom Martin
- Department of Plant Biology, Swedish University of Agricultural Sciences, The Linnean Centre of Plant Biology in Uppsala, Uppsala, Sweden
| | - John Mundy
- Department of Biology, University of Copenhagen, Copenhagen N, Denmark
| | - Morten Petersen
- Department of Biology, University of Copenhagen, Copenhagen N, Denmark
| | - Mattias Thelander
- Department of Plant Biology, Swedish University of Agricultural Sciences, The Linnean Centre of Plant Biology in Uppsala, Uppsala, Sweden
| | - Eva Sundberg
- Department of Plant Biology, Swedish University of Agricultural Sciences, The Linnean Centre of Plant Biology in Uppsala, Uppsala, Sweden
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19
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Bortnik S, Gorski SM. Clinical Applications of Autophagy Proteins in Cancer: From Potential Targets to Biomarkers. Int J Mol Sci 2017; 18:ijms18071496. [PMID: 28696368 PMCID: PMC5535986 DOI: 10.3390/ijms18071496] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2017] [Revised: 07/06/2017] [Accepted: 07/07/2017] [Indexed: 12/20/2022] Open
Abstract
Autophagy, a lysosome-mediated intracellular degradation and recycling pathway, plays multiple context-dependent roles in tumorigenesis and treatment resistance. Encouraging results from various preclinical studies have led to the initiation of numerous clinical trials with the intention of targeting autophagy in various cancers. Accumulating knowledge of the particular mechanisms and players involved in different steps of autophagy regulation led to the ongoing discovery of small molecule inhibitors designed to disrupt this highly orchestrated process. However, the development of validated autophagy-related biomarkers, essential for rational selection of patients entering clinical trials involving autophagy inhibitors, is lagging behind. One possible source of biomarkers for this purpose is the autophagy machinery itself. In this review, we address the recent trends, challenges and advances in the assessment of the biomarker potential of clinically relevant autophagy proteins in human cancers.
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Affiliation(s)
- Svetlana Bortnik
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, Vancouver, BC V5Z 1L3, Canada.
- Interdisciplinary Oncology Program, University of British Columbia, Vancouver, BC V5Z 1L3, Canada.
| | - Sharon M Gorski
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, Vancouver, BC V5Z 1L3, Canada.
- Interdisciplinary Oncology Program, University of British Columbia, Vancouver, BC V5Z 1L3, Canada.
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada.
- Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, BC V5A 1S6, Canada.
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20
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Li H, Wu J, Shen H, Yao X, Liu C, Pianta S, Han J, Borlongan CV, Chen G. Autophagy in hemorrhagic stroke: Mechanisms and clinical implications. Prog Neurobiol 2017; 163-164:79-97. [PMID: 28414101 DOI: 10.1016/j.pneurobio.2017.04.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 02/13/2017] [Accepted: 04/08/2017] [Indexed: 02/07/2023]
Abstract
Accumulating evidence advances the critical role of autophagy in brain pathology after stroke. Investigations employing autophagy induction or inhibition using pharmacological tools or autophagy-related gene knockout mice have recently revealed the biological significance of intact and functional autophagy in stroke. Most of the reported cases attest to a pro-survival role for autophagy in stroke, by facilitating removal of damaged proteins and organelles, which can be recycled for energy generation and cellular defenses. However, these observations are difficult to reconcile with equally compelling evidence demonstrating stroke-induced upregulation of brain cell death index that parallels enhanced autophagy. This begs the question of whether drug-induced autophagy during stroke culminates in improved or worsened pathological outcomes. A corollary fascinating hypothesis, but presents as a tricky conundrum, involves the effects of autophagy on cell death and inflammation, which are two main culprits in the disease progression of stroke-induced brain injury. Evidence has extended the roles of autophagy in inflammation via cytokine regulation in an unconventional secretion manner or by targeting inflammasomes for degradation. Moreover, in the recently concluded Vancouver Autophagy Symposium (VAS) held in 2014, the potential of selective autophagy for clinical treatment has been recognized. The role of autophagy in ischemic stroke has been reviewed previously in detail. Here, we evaluate the strength of laboratory and clinical evidence by providing a comprehensive summary of the literature on autophagy, and thereafter we offer our perspectives on exploiting autophagy as a drug target for cerebral ischemia, especially in hemorrhagic stroke.
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Affiliation(s)
- Haiying Li
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University,188 Shizi Street, Suzhou 215006, China
| | - Jiang Wu
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University,188 Shizi Street, Suzhou 215006, China
| | - Haitao Shen
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University,188 Shizi Street, Suzhou 215006, China
| | - Xiyang Yao
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University,188 Shizi Street, Suzhou 215006, China
| | - Chenglin Liu
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University,188 Shizi Street, Suzhou 215006, China
| | - S Pianta
- Center of Excellence for Aging and Brain Repair, Department of Neurosurgery & Brain Repair, University of South Florida Morsani College of Medicine,12901 Bruce B Downs Blvd Tampa, FL 33612 USA
| | - J Han
- Center of Excellence for Aging and Brain Repair, Department of Neurosurgery & Brain Repair, University of South Florida Morsani College of Medicine,12901 Bruce B Downs Blvd Tampa, FL 33612 USA
| | - C V Borlongan
- Center of Excellence for Aging and Brain Repair, Department of Neurosurgery & Brain Repair, University of South Florida Morsani College of Medicine,12901 Bruce B Downs Blvd Tampa, FL 33612 USA
| | - Gang Chen
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University,188 Shizi Street, Suzhou 215006, China.
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21
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Ye LY, Hu S, Xu HE, Xu RR, Kong H, Zeng XN, Xie WP, Wang H. The effect of tetrandrine combined with cisplatin on proliferation and apoptosis of A549/DDP cells and A549 cells. Cancer Cell Int 2017; 17:40. [PMID: 28360820 PMCID: PMC5368997 DOI: 10.1186/s12935-017-0410-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 03/11/2017] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Non-small cell lung cancer comprises the majority of lung cancer cases and is insensitive to chemotherapy. Most patients develop drug resistance. Recently, tetrandrine (TET), a bis-benzylisoquinoline alkaloid, was identified as a novel anti-cancer agent. However, the effect of tetrandrine combined with cisplatin on lung cancer has not yet been studied. We aimed to identify a possible synergistic effect between tetrandrine and cisplatin, besides, to investigate the effects of TET in combination with DDP on proliferation and apoptosis in cisplatin-resistant and cisplatin-sensitive A549 cell lines, and to study the underlying mechanism. METHODS Cell viability was confirmed with CCK8 assays, and the IC50 values for each treatment group were calculated. The synergistic interaction of these drugs was evaluated using an isobolographic analysis. Proliferation was assessed by EDU staining. Hoechst staining and flow cytometry were used to assess apoptosis. Apoptosis- and autophagy-associated proteins were analyzed by western blot. Transmission electron microscopy was used to detect autophagy, RFP-GFP-LC3 lentivirus was used to perform autophagic flux assay. RESULTS Tetrandrine and cisplatin exerted synergistic cytotoxic effects on both cisplatin-resistant and cisplatin-sensitive A549 cell lines. The combination of tetrandrine and cisplatin induced apoptosis and inhibited proliferation in a synergistic manner. The formation of autophagosomes was evident by transmission electron microscopy. The autophagic flux of combination treatment was increased. CONCLUSIONS Tetrandrine synergized with cisplatin to reduce the viability of cisplatin-resistant and cisplatin-sensitive A549 cells, tetrandrine could reverse the resistance of A549 cells to cisplatin. Tetrandrine combined with cisplatin could induce autophagy. Therefore, tetrandrine is a potent autophagy agonist and may be a promising drug for the treatment of non-small cell lung cancer.
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Affiliation(s)
- Ling-Yun Ye
- 0000 0004 1799 0784grid.412676.0Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029 Jiangsu People’s Republic of China
| | - Song Hu
- 0000 0004 1799 0784grid.412676.0Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029 Jiangsu People’s Republic of China
| | - Hua-E Xu
- 0000 0004 1799 0784grid.412676.0Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029 Jiangsu People’s Republic of China ,0000 0004 1799 0784grid.412676.0Department of Pharmacy, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029 Jiangsu People’s Republic of China
| | - Rong-Rong Xu
- 0000 0004 1799 0784grid.412676.0Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029 Jiangsu People’s Republic of China
| | - Hui Kong
- 0000 0004 1799 0784grid.412676.0Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029 Jiangsu People’s Republic of China
| | - Xiao-Ning Zeng
- 0000 0004 1799 0784grid.412676.0Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029 Jiangsu People’s Republic of China
| | - Wei-Ping Xie
- 0000 0004 1799 0784grid.412676.0Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029 Jiangsu People’s Republic of China
| | - Hong Wang
- 0000 0004 1799 0784grid.412676.0Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029 Jiangsu People’s Republic of China
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Borland H, Vilhardt F. Prelysosomal Compartments in the Unconventional Secretion of Amyloidogenic Seeds. Int J Mol Sci 2017; 18:ijms18010227. [PMID: 28124989 PMCID: PMC5297856 DOI: 10.3390/ijms18010227] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 01/09/2017] [Accepted: 01/16/2017] [Indexed: 12/18/2022] Open
Abstract
A mechanistic link between neuron-to-neuron transmission of secreted amyloid and propagation of protein malconformation cytopathology and disease has recently been uncovered in animal models. An enormous interest in the unconventional secretion of amyloids from neurons has followed. Amphisomes and late endosomes are the penultimate maturation products of the autophagosomal and endosomal pathways, respectively, and normally fuse with lysosomes for degradation. However, under conditions of perturbed membrane trafficking and/or lysosomal deficiency, prelysosomal compartments may instead fuse with the plasma membrane to release any contained amyloid. After a brief introduction to the endosomal and autophagosomal pathways, we discuss the evidence for autophagosomal secretion (exophagy) of amyloids, with a comparative emphasis on Aβ1-42 and α-synuclein, as luminal and cytosolic amyloids, respectively. The ESCRT-mediated import of cytosolic amyloid into late endosomal exosomes, a known vehicle of transmission of macromolecules between cells, is also reviewed. Finally, mechanisms of lysosomal dysfunction, deficiency, and exocytosis are exemplified in the context of genetically identified risk factors, mainly for Parkinson's disease. Exocytosis of prelysosomal or lysosomal organelles is a last resort for clearance of cytotoxic material and alleviates cytopathy. However, they also represent a vehicle for the concentration, posttranslational modification, and secretion of amyloid seeds.
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Affiliation(s)
- Helena Borland
- Department of Neurodegeneration In Vitro, H. Lundbeck A/S, 2500 Valby, Denmark.
| | - Frederik Vilhardt
- Department of Cellular and Molecular Medicine, Panum Institute, University of Copenhagen, 2200N Copenhagen, Denmark.
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23
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Queiroz RML, Ricart CAO, Machado MO, Bastos IMD, de Santana JM, de Sousa MV, Roepstorff P, Charneau S. Insight into the Exoproteome of the Tissue-Derived Trypomastigote form of Trypanosoma cruzi. Front Chem 2016; 4:42. [PMID: 27872839 PMCID: PMC5097913 DOI: 10.3389/fchem.2016.00042] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 10/19/2016] [Indexed: 01/07/2023] Open
Abstract
The protozoan parasite Trypanosoma cruzi causes Chagas disease, one of the major neglected infectious diseases. It has the potential to infect any nucleated mammalian cell. The secreted/excreted protein repertoire released by T. cruzi trypomastigotes is crucial in host-pathogen interactions. In this study, mammalian tissue culture-derived trypomastigotes (Y strain) were used to characterize the exoproteome of the infective bloodstream life form. Proteins released into the serum-free culture medium after 3 h of incubation were harvested and digested with trypsin. NanoLC-MS/MS analysis resulted in the identification of 540 proteins, the largest set of released proteins identified to date in Trypanosoma spp. Bioinformatic analysis predicted most identified proteins as secreted, predominantly by non-classical pathways, and involved in host-cell infection. Some proteins possess predicted GPI-anchor signals, these being mostly trans-sialidases, mucin associated surface proteins and surface glycoproteins. Moreover, we enriched phosphopeptides and glycopeptides from tryptic digests. The majority of identified glycoproteins are trans-sialidases and surface glycoproteins involved in host-parasite interaction. Conversely, most identified phosphoproteins have no Gene Ontology classification. The existence of various proteins related to similar functions in the exoproteome likely reflects this parasite's enhanced mechanisms for adhesion, invasion, and internalization of different host-cell types, and escape from immune defenses.
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Affiliation(s)
- Rayner M L Queiroz
- Laboratory of Biochemistry and Protein Chemistry, Department of Cell Biology, University of Brasilia, Brasilia, Brazil; Department of Biochemistry and Molecular Biology, University of Southern DenmarkOdense, Denmark
| | - Carlos A O Ricart
- Laboratory of Biochemistry and Protein Chemistry, Department of Cell Biology, University of Brasilia , Brasilia, Brazil
| | - Mara O Machado
- Laboratory of Biochemistry and Protein Chemistry, Department of Cell Biology, University of Brasilia , Brasilia, Brazil
| | - Izabela M D Bastos
- Laboratory of Host-Pathogen Interaction, Department of Cell Biology, University of Brasilia Brasilia, Brazil
| | - Jaime M de Santana
- Laboratory of Host-Pathogen Interaction, Department of Cell Biology, University of Brasilia Brasilia, Brazil
| | - Marcelo V de Sousa
- Laboratory of Host-Pathogen Interaction, Department of Cell Biology, University of Brasilia Brasilia, Brazil
| | - Peter Roepstorff
- Department of Biochemistry and Molecular Biology, University of Southern Denmark Odense, Denmark
| | - Sébastien Charneau
- Laboratory of Biochemistry and Protein Chemistry, Department of Cell Biology, University of Brasilia , Brasilia, Brazil
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24
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Canonico B, Cesarini E, Salucci S, Luchetti F, Falcieri E, Di Sario G, Palma F, Papa S. Defective Autophagy, Mitochondrial Clearance and Lipophagy in Niemann-Pick Type B Lymphocytes. PLoS One 2016; 11:e0165780. [PMID: 27798705 PMCID: PMC5087958 DOI: 10.1371/journal.pone.0165780] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 10/18/2016] [Indexed: 12/21/2022] Open
Abstract
Niemann-Pick disease type A (NP-A) and type B (NP-B) are lysosomal storage diseases (LSDs) caused by sphingomyelin accumulation in lysosomes relying on reduced or absent acid sphingomyelinase. A considerable body of evidence suggests that lysosomal storage in many LSD impairs autophagy, resulting in the accumulation of poly-ubiquitinated proteins and dysfunctional mitochondria, ultimately leading to cell death. Here we test this hypothesis in a cellular model of Niemann-Pick disease type B, in which autophagy has never been studied. The basal autophagic pathway was first examined in order to evaluate its functionality using several autophagy-modulating substances such as rapamycin and nocodazole. We found that human NP-B B lymphocytes display considerable alteration in their autophagic vacuole accumulation and mitochondrial fragmentation, as well as mitophagy induction (for damaged mitochondria clearance). Furthermore, lipid traceability of intra and extra-cellular environments shows lipid accumulation in NP-B B lymphocytes and also reveals their peculiar trafficking/management, culminating in lipid microparticle extrusion (by lysosomal exocytosis mechanisms) or lipophagy. All of these features point to the presence of a deep autophagy/mitophagy alteration revealing autophagic stress and defective mitochondrial clearance. Hence, rapamycin might be used to regulate autophagy/mitophagy (at least in part) and to contribute to the clearance of lysosomal aberrant lipid storage.
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Affiliation(s)
- Barbara Canonico
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
- * E-mail:
| | - Erica Cesarini
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
| | - Sara Salucci
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
| | - Francesca Luchetti
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
| | - Elisabetta Falcieri
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
- IGM, CNR, Rizzoli Orthopaedic Institute, Bologna, Italy; Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
| | - Gianna Di Sario
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
| | - Fulvio Palma
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
| | - Stefano Papa
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
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25
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Morell C, Bort A, Vara-Ciruelos D, Ramos-Torres Á, Altamirano-Dimas M, Díaz-Laviada I, Rodríguez-Henche N. Up-Regulated Expression of LAMP2 and Autophagy Activity during Neuroendocrine Differentiation of Prostate Cancer LNCaP Cells. PLoS One 2016; 11:e0162977. [PMID: 27627761 PMCID: PMC5023108 DOI: 10.1371/journal.pone.0162977] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 08/31/2016] [Indexed: 11/18/2022] Open
Abstract
Neuroendocrine (NE) prostate cancer (PCa) is a highly aggressive subtype of prostate cancer associated with resistance to androgen ablation therapy. In this study, we used LNCaP prostate cancer cells cultured in a serum-free medium for 6 days as a NE model of prostate cancer. Serum deprivation increased the expression of NE markers such as neuron-specific enolase (NSE) and βIII tubulin (βIII tub) and decreased the expression of the androgen receptor protein in LNCaP cells. Using cDNA microarrays, we compared gene expression profiles of NE cells and non-differentiated LNCaP cells. We identified up-regulation of 155 genes, among them LAMP2, a lysosomal membrane protein involved in lysosomal stability and autophagy. We then confirmed up-regulation of LAMP2 in NE cells by qRT-PCR, Western blot and confocal microscopy assays, showing that mRNA up-regulation correlated with increased levels of LAMP2 protein. Subsequently, we determined autophagy activity in NE cells by assessing the protein levels of SQSTM/p62 and LC3 by Western blot and LC3 and Atg5 mRNAs content by qRT-PCR. The decreased levels of SQSTM/p62 was accompanied by an enhanced expression of LC3 and ATG5, suggesting activation of autophagy in NE cells. Blockage of autophagy with 1μM AKT inhibitor IV, or by silencing Beclin 1 and Atg5, prevented NE cell differentiation, as revealed by decreased levels of the NE markers. In addition, AKT inhibitor IV as well as Beclin1 and Atg5 kwockdown attenuated LAMP2 expression in NE cells. On the other hand, LAMP2 knockdown by siRNA led to a marked blockage of autophagy, prevention of NE differentiation and decrease of cell survival. Taken together, these results suggest that LAMP2 overexpression assists NE differentiation of LNCaP cells induced by serum deprivation and facilitates autophagy activity in order to attain the NE phenotype and cell survival. LAMP2 could thus be a potential biomarker and potential target for NE prostate cancer.
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Affiliation(s)
- Cecilia Morell
- Department of Systems Biology, Biochemistry and Molecular Biology Unit, School of Medicine and Health Sciences, University of Alcalá, Alcalá de Henares, Spain
| | - Alicia Bort
- Department of Systems Biology, Biochemistry and Molecular Biology Unit, School of Medicine and Health Sciences, University of Alcalá, Alcalá de Henares, Spain
| | - Diana Vara-Ciruelos
- Cell Signalling and Immunology, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Ágata Ramos-Torres
- Department of Systems Biology, Biochemistry and Molecular Biology Unit, School of Medicine and Health Sciences, University of Alcalá, Alcalá de Henares, Spain
| | | | - Inés Díaz-Laviada
- Department of Systems Biology, Biochemistry and Molecular Biology Unit, School of Medicine and Health Sciences, University of Alcalá, Alcalá de Henares, Spain
| | - Nieves Rodríguez-Henche
- Department of Systems Biology, Biochemistry and Molecular Biology Unit, School of Medicine and Health Sciences, University of Alcalá, Alcalá de Henares, Spain
- * E-mail:
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26
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Overexpression of Plasmodium berghei ATG8 by Liver Forms Leads to Cumulative Defects in Organelle Dynamics and to Generation of Noninfectious Merozoites. mBio 2016; 7:mBio.00682-16. [PMID: 27353755 PMCID: PMC4937212 DOI: 10.1128/mbio.00682-16] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Plasmodium parasites undergo continuous cellular renovation to adapt to various environments in the vertebrate host and insect vector. In hepatocytes, Plasmodium berghei discards unneeded organelles for replication, such as micronemes involved in invasion. Concomitantly, intrahepatic parasites expand organelles such as the apicoplast that produce essential metabolites. We previously showed that the ATG8 conjugation system is upregulated in P. berghei liver forms and that P. berghei ATG8 (PbATG8) localizes to the membranes of the apicoplast and cytoplasmic vesicles. Here, we focus on the contribution of PbATG8 to the organellar changes that occur in intrahepatic parasites. We illustrated that micronemes colocalize with PbATG8-containing structures before expulsion from the parasite. Interference with PbATG8 function by overexpression results in poor development into late liver stages and production of small merosomes that contain immature merozoites unable to initiate a blood infection. At the cellular level, PbATG8-overexpressing P. berghei exhibits a delay in microneme compartmentalization into PbATG8-containing autophagosomes and elimination compared to parasites from the parental strain. The apicoplast, identifiable by immunostaining of the acyl carrier protein (ACP), undergoes an abnormally fast proliferation in mutant parasites. Over time, the ACP staining becomes diffuse in merosomes, indicating a collapse of the apicoplast. PbATG8 is not incorporated into the progeny of mutant parasites, in contrast to parental merozoites in which PbATG8 and ACP localize to the apicoplast. These observations reveal that Plasmodium ATG8 is a key effector in the development of merozoites by controlling microneme clearance and apicoplast proliferation and that dysregulation in ATG8 levels is detrimental for malaria infectivity. IMPORTANCE Malaria is responsible for more mortality than any other parasitic disease. Resistance to antimalarial medicines is a recurring problem; new drugs are urgently needed. A key to the parasite's successful intracellular development in the liver is the metabolic changes necessary to convert the parasite from a sporozoite to a replication-competent, metabolically active trophozoite form. Our study reinforces the burgeoning concept that organellar changes during parasite differentiation are mediated by an autophagy-like process. We have identified ATG8 in Plasmodium liver forms as an important effector that controls the development and fate of organelles, e.g., the clearance of micronemes that are required for hepatocyte invasion and the expansion of the apicoplast that produces many metabolites indispensable for parasite replication. Given the unconventional properties and the importance of ATG8 for parasite development in hepatocytes, targeting the parasite's autophagic pathway may represent a novel approach to control malarial infections.
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27
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Gangalum RK, Bhat AM, Kohan SA, Bhat SP. Inhibition of the Expression of the Small Heat Shock Protein αB-Crystallin Inhibits Exosome Secretion in Human Retinal Pigment Epithelial Cells in Culture. J Biol Chem 2016; 291:12930-42. [PMID: 27129211 DOI: 10.1074/jbc.m115.698530] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Indexed: 01/15/2023] Open
Abstract
Exosomes carry cell type-specific molecular cargo to extracellular destinations and therefore act as lateral vectors of intercellular communication and transfer of genetic information from one cell to the other. We have shown previously that the small heat shock protein αB-crystallin (αB) is exported out of the adult human retinal pigment epithelial cells (ARPE19) packaged in exosomes. Here, we demonstrate that inhibition of the expression of αB via shRNA inhibits exosome secretion from ARPE19 cells indicating that exosomal cargo may have a role in exosome biogenesis (synthesis and/or secretion). Sucrose density gradient fractionation of the culture medium and cellular extracts suggests continued synthesis of exosomes but an inhibition of exosome secretion. In cells where αB expression was inhibited, the distribution of CD63 (LAMP3), an exosome marker, is markedly altered from the normal dispersed pattern to a stacked perinuclear presence. Interestingly, the total anti-CD63(LAMP3) immunofluorescence in the native and αB-inhibited cells remains unchanged suggesting continued exosome synthesis under conditions of impaired exosome secretion. Importantly, inhibition of the expression of αB results in a phenotype of the RPE cell that contains an increased number of vacuoles and enlarged (fused) vesicles that show increased presence of CD63(LAMP3) and LAMP1 indicating enhancement of the endolysosomal compartment. This is further corroborated by increased Rab7 labeling of this compartment (RabGTPase 7 is known to be associated with late endosome maturation). These data collectively point to a regulatory role for αB in exosome biogenesis possibly via its involvement at a branch point in the endocytic pathway that facilitates secretion of exosomes.
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Affiliation(s)
| | - Ankur M Bhat
- From the Jules Stein Eye Institute, Geffen School of Medicine
| | - Sirus A Kohan
- Brain Research Institute, UCLA, Los Angeles, California 90095
| | - Suraj P Bhat
- From the Jules Stein Eye Institute, Geffen School of Medicine, Brain Research Institute, UCLA, Los Angeles, California 90095 Molecular Biology Institute and
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28
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Ahmed W, Zheng K, Liu ZF. Establishment of Chronic Infection: Brucella's Stealth Strategy. Front Cell Infect Microbiol 2016; 6:30. [PMID: 27014640 PMCID: PMC4791395 DOI: 10.3389/fcimb.2016.00030] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 02/29/2016] [Indexed: 01/18/2023] Open
Abstract
Brucella is a facultative intracellular pathogen that causes zoonotic infection known as brucellosis which results in abortion and infertility in natural host. Humans, especially in low income countries, can acquire infection by direct contact with infected animal or by consumption of animal products and show high morbidity, severe economic losses and public health problems. However for survival, host cells develop complex immune mechanisms to defeat and battle against attacking pathogens and maintain a balance between host resistance and Brucella virulence. On the other hand as a successful intracellular pathogen, Brucella has evolved multiple strategies to evade immune response mechanisms to establish persistent infection and replication within host. In this review, we mainly summarize the "Stealth" strategies employed by Brucella to modulate innate and the adaptive immune systems, autophagy, apoptosis and possible role of small noncoding RNA in the establishment of chronic infection. The purpose of this review is to give an overview for recent understanding how this pathogen evades immune response mechanisms of host, which will facilitate to understanding the pathogenesis of brucellosis and the development of novel, more effective therapeutic approaches to treat brucellosis.
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Affiliation(s)
- Waqas Ahmed
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University Wuhan, China
| | - Ke Zheng
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University Wuhan, China
| | - Zheng-Fei Liu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University Wuhan, China
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29
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Zhang M, Kenny SJ, Ge L, Xu K, Schekman R. Translocation of interleukin-1β into a vesicle intermediate in autophagy-mediated secretion. eLife 2015; 4:e11205. [PMID: 26523392 PMCID: PMC4728131 DOI: 10.7554/elife.11205] [Citation(s) in RCA: 262] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 10/30/2015] [Indexed: 12/23/2022] Open
Abstract
Recent evidence suggests that autophagy facilitates the unconventional secretion of the pro-inflammatory cytokine interleukin 1β (IL-1β). Here, we reconstituted an autophagy-regulated secretion of mature IL-1β (m-IL-1β) in non-macrophage cells. We found that cytoplasmic IL-1β associates with the autophagosome and m-IL-1β enters into the lumen of a vesicle intermediate but not into the cytoplasmic interior formed by engulfment of the autophagic membrane. In advance of secretion, m-IL-1β appears to be translocated across a membrane in an event that may require m-IL-1β to be unfolded or remain conformationally flexible and is dependent on two KFERQ-like motifs essential for the association of IL-1β with HSP90. A vesicle, possibly a precursor of the phagophore, contains translocated m-IL-1β and later turns into an autophagosome in which m-IL-1β resides within the intermembrane space of the double-membrane structure. Completion of IL-1β secretion requires Golgi reassembly and stacking proteins (GRASPs) and multi-vesicular body (MVB) formation.
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Affiliation(s)
- Min Zhang
- Department of Molecular and Cell Biology, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, United States
| | - Samuel J Kenny
- Department of Chemistry, University of California, Berkeley, Berkeley, United States
| | - Liang Ge
- Department of Molecular and Cell Biology, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, United States
| | - Ke Xu
- Department of Chemistry, University of California, Berkeley, Berkeley, United States
| | - Randy Schekman
- Department of Molecular and Cell Biology, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, United States
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30
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Pierrefite-Carle V, Santucci-Darmanin S, Breuil V, Camuzard O, Carle GF. Autophagy in bone: Self-eating to stay in balance. Ageing Res Rev 2015; 24:206-17. [PMID: 26318060 DOI: 10.1016/j.arr.2015.08.004] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 08/18/2015] [Accepted: 08/20/2015] [Indexed: 12/14/2022]
Abstract
Autophagy, a major catabolic pathway responsible of the elimination of damaged proteins and organelles, is now recognized as an anti-aging process. In addition to its basal role in cell homeostasis, autophagy is also a stress-responsive mechanism for survival purposes. Here, we review recent literature to highlight the autophagy role in the different bone cell types, i.e., osteoblasts, osteoclasts and osteocytes. We also discuss the effects of autophagy modulators in bone physiology and of bone anabolic compounds in autophagy. Finally, we analyzed studies regarding bone cell autophagy-deficient mouse models to obtain a more general view on how autophagy modulates bone physiology and pathophysiology, particularly during aging.
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Affiliation(s)
- Valérie Pierrefite-Carle
- UMR E-4320 TIRO-MATOs CEA/iBEB, Université Nice Sophia Antipolis, Faculté de Médecine Nice, France.
| | - Sabine Santucci-Darmanin
- UMR E-4320 TIRO-MATOs CEA/iBEB, Université Nice Sophia Antipolis, Faculté de Médecine Nice, France
| | - Véronique Breuil
- UMR E-4320 TIRO-MATOs CEA/iBEB, Université Nice Sophia Antipolis, Faculté de Médecine Nice, France; Service de Rhumatologie, CHU de Nice, Nice, France
| | - Olivier Camuzard
- UMR E-4320 TIRO-MATOs CEA/iBEB, Université Nice Sophia Antipolis, Faculté de Médecine Nice, France; Service de Chirurgie Réparatrice et de la main, CHU de Nice, Nice, France
| | - Georges F Carle
- UMR E-4320 TIRO-MATOs CEA/iBEB, Université Nice Sophia Antipolis, Faculté de Médecine Nice, France
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31
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Shapiro IM, Landis WJ, Risbud MV. Matrix vesicles: Are they anchored exosomes? Bone 2015; 79:29-36. [PMID: 25980744 PMCID: PMC4501874 DOI: 10.1016/j.bone.2015.05.013] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 05/05/2015] [Accepted: 05/08/2015] [Indexed: 10/23/2022]
Abstract
Numerous studies have documented that matrix vesicles are unique extracellular membrane-bound microparticles that serve as initial sites for mineral formation in the growth plate and most other vertebrate mineralizing tissues. Microparticle generation is not confined to hard tissues, as cells in soft tissues generate similar structures; numerous studies have shown that a common type of extracellular particle, termed an exosome, a product of the endosomal pathway, shares many characteristics of matrix vesicles. Indeed, analyses of size, morphology and lipid and protein content indicate that matrix vesicles and exosomes are homologous structures. Such a possibility impacts our understanding of the biogenesis, processing and function of matrix vesicles (exosomes) in vertebrate hard tissues and explains in part how cells control the earliest stages of mineral deposition. Moreover, since exosomes influence a spectrum of functions, including cell-cell communication, it is suggested that this type of microparticle may provide a mechanism for the transfer of signaling molecules between cells within the growth plate and thereby regulate endochondral bone development and formation.
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Affiliation(s)
- Irving M Shapiro
- Department of Orthopedic Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA.
| | - William J Landis
- Department of Polymer Science, College of Polymer Science and Polymer Engineering, University of Akron, OH, USA
| | - Makarand V Risbud
- Department of Orthopedic Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
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32
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Abstract
There is increasing interest in the role of autophagic flux in maintaining normal vessel wall biology and a growing suspicion that autophagic dysregulation may be a common pathway through which vascular aging and associated pathologies develop. Within endothelial and smooth muscle cells, diverse but important triggers that range from oxidized lipids to β-amyloid seem to stimulate autophagosome formation potently. In addition, emerging evidence links autophagy to a wide array of vascular processes ranging from angiogenesis to calcification of the vessel wall. Alterations in autophagic flux are also increasingly being implicated in disease processes that include both atherosclerosis and pulmonary hypertension. Finally, recent insights point toward an important role of autophagy in the paracrine regulation of vasoactive substances from the endothelium. Here, we review the progress in understanding how autophagy can contribute to vascular biology and the emerging strategies to target this process for therapeutic benefit.
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Affiliation(s)
- Samuel C Nussenzweig
- From the Center for Molecular Medicine, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (S.C.N, T.F.); and Division of Cardiac Surgery, St Michael's Hospital, University of Toronto, Toronto, Ontario, Canada (S.V.)
| | - Subodh Verma
- From the Center for Molecular Medicine, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (S.C.N, T.F.); and Division of Cardiac Surgery, St Michael's Hospital, University of Toronto, Toronto, Ontario, Canada (S.V.)
| | - Toren Finkel
- From the Center for Molecular Medicine, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (S.C.N, T.F.); and Division of Cardiac Surgery, St Michael's Hospital, University of Toronto, Toronto, Ontario, Canada (S.V.).
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33
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Rajasekhar K, Suresh SN, Manjithaya R, Govindaraju T. Rationally designed peptidomimetic modulators of aβ toxicity in Alzheimer's disease. Sci Rep 2015; 5:8139. [PMID: 25633824 PMCID: PMC4311240 DOI: 10.1038/srep08139] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 01/08/2015] [Indexed: 12/21/2022] Open
Abstract
Alzheimer's disease is one of the devastating illnesses mankind is facing in the 21st century. The main pathogenic event in Alzheimer's disease is believed to be the aggregation of the β-amyloid (Aβ) peptides into toxic aggregates. Molecules that interfere with this process may act as therapeutic agents for the treatment of the disease. Use of recognition unit based peptidomimetics as inhibitors are a promising approach, as they exhibit greater protease stability compared to natural peptides. Here, we present peptidomimetic inhibitors of Aβ aggregation designed based on the KLVFF (P1) sequence that is known to bind Aβ aggregates. We improved inhibition efficiency of P1 by introducing multiple hydrogen bond donor-acceptor moieties (thymine/barbiturate) at the N-terminal (P2 and P3), and blood serum stability by modifying the backbone by incorporating sarcosine (N-methylglycine) units at alternate positions (P4 and P5). The peptidomimetics showed moderate to good activity in both inhibition and dissolution of Aβ aggregates as depicted by thioflavin assay, circular dichroism (CD) measurements and microscopy (TEM). The activity of P4 and P5 were studied in a yeast cell model showing Aβ toxicity. P4 and P5 could rescue yeast cells from Aβ toxicity and Aβ aggregates were cleared by the process of autophagy.
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Affiliation(s)
- K. Rajasekhar
- Bioorganic Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bengaluru 560064, Karnataka, India
| | - S. N. Suresh
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bengaluru 560064, Karnataka, India
| | - Ravi Manjithaya
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bengaluru 560064, Karnataka, India
| | - T. Govindaraju
- Bioorganic Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bengaluru 560064, Karnataka, India
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Couve A, Hetz C. RESETing ER proteostasis: selective stress pathway hidden in the secretory route. EMBO J 2014; 33:2444-6. [PMID: 25190517 DOI: 10.15252/embj.201489845] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Andrés Couve
- Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile Program of Physiology and Biophysics, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile
| | - Claudio Hetz
- Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile Program of Cellular and Molecular Biology, Center for Molecular Studies of the Cell, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile
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Ding Y, Robinson DG, Jiang L. Unconventional protein secretion (UPS) pathways in plants. Curr Opin Cell Biol 2014; 29:107-15. [PMID: 24949560 DOI: 10.1016/j.ceb.2014.05.008] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 04/09/2014] [Accepted: 05/22/2014] [Indexed: 02/09/2023]
Abstract
As in yeast and mammalian cells, novel unconventional protein secretion (UPS) or unconventional membrane trafficking pathways are now known to operate in plants. UPS in plants is generally associated with stress conditions such as pathogen attack, but little is known about its underlying mechanism and function. Here, we present an update on the current knowledge of UPS in the plants in terms of its transport pathways, possible functions and its relationship to autophagy.
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Affiliation(s)
- Yu Ding
- School of Life Sciences, Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - David G Robinson
- Centre for Organismal Studies, University of Heidelberg, D-69120 Heidelberg, Germany
| | - Liwen Jiang
- School of Life Sciences, Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China; Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen 518057, China.
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Accumulation of amyloid-like Aβ1-42 in AEL (autophagy-endosomal-lysosomal) vesicles: potential implications for plaque biogenesis. ASN Neuro 2014; 6:AN20130044. [PMID: 24521233 PMCID: PMC4379859 DOI: 10.1042/an20130044] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Abnormal accumulation of Aβ (amyloid β) within AEL (autophagy-endosomal-lysosomal) vesicles is a prominent neuropathological feature of AD (Alzheimer's disease), but the mechanism of accumulation within vesicles is not clear. We express secretory forms of human Aβ1-40 or Aβ1-42 in Drosophila neurons and observe preferential localization of Aβ1-42 within AEL vesicles. In young animals, Aβ1-42 appears to associate with plasma membrane, whereas Aβ1-40 does not, suggesting that recycling endocytosis may underlie its routing to AEL vesicles. Aβ1-40, in contrast, appears to partially localize in extracellular spaces in whole brain and is preferentially secreted by cultured neurons. As animals become older, AEL vesicles become dysfunctional, enlarge and their turnover appears delayed. Genetic inhibition of AEL function results in decreased Aβ1-42 accumulation. In samples from older animals, Aβ1-42 is broadly distributed within neurons, but only the Aβ1-42 within dysfunctional AEL vesicles appears to be in an amyloid-like state. Moreover, the Aβ1-42-containing AEL vesicles share properties with AD-like extracellular plaques. They appear to be able to relocate to extracellular spaces either as a consequence of age-dependent neurodegeneration or a non-neurodegenerative separation from host neurons by plasma membrane infolding. We propose that dysfunctional AEL vesicles may thus be the source of amyloid-like plaque accumulation in Aβ1-42-expressing Drosophila with potential relevance for AD.
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Dourado IBZ, Batista WL, Longo LVG, Mortara RA, Puccia R. Dual localization of Mdj1 in pathogenic fungi varies with growth temperature. Med Mycol 2014; 52:187-95. [DOI: 10.1093/mmy/myt002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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Lock R, Kenific CM, Leidal AM, Salas E, Debnath J. Autophagy-dependent production of secreted factors facilitates oncogenic RAS-driven invasion. Cancer Discov 2014; 4:466-79. [PMID: 24513958 DOI: 10.1158/2159-8290.cd-13-0841] [Citation(s) in RCA: 204] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
UNLABELLED The tumor-promoting functions of autophagy are primarily attributed to its ability to promote cancer cell survival. However, emerging evidence suggests that autophagy plays other roles during tumorigenesis. Here, we uncover that autophagy promotes oncogenic RAS-driven invasion. In epithelial cells transformed with oncogenic RAS, depletion of autophagy-related genes suppresses invasion in three-dimensional culture, decreases cell motility, and reduces pulmonary metastases in vivo. Treatment with conditioned media from autophagy-competent cells rescues the invasive capacity of autophagy-deficient cells, indicating that these cells fail to secrete factors required for RAS-driven invasion. Reduced autophagy diminishes the secretion of the promigratory cytokine interleukin-6 (IL-6), which is necessary to restore invasion of autophagy-deficient cells. Moreover, autophagy-deficient cells exhibit reduced levels of matrix metalloproteinase 2 and WNT5A. These results support a previously unrecognized function for autophagy in promoting cancer cell invasion via the coordinate production of multiple secreted factors. SIGNIFICANCE Our results delineate a previously unrecognized function for autophagy in facilitating oncogenic RAS-driven invasion. We demonstrate that an intact autophagy pathway is required for the elaboration of multiple secreted factors favoring invasion, including IL-6.
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Affiliation(s)
- Rebecca Lock
- Department of Pathology, Helen Diller Family Comprehensive Cancer Center and Biomedical Science Graduate Program, University of California San Francisco, San Francisco, California
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Mariño G, Niso-Santano M, Baehrecke EH, Kroemer G. Self-consumption: the interplay of autophagy and apoptosis. Nat Rev Mol Cell Biol 2014; 15:81-94. [PMID: 24401948 DOI: 10.1038/nrm3735q10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Autophagy and apoptosis control the turnover of organelles and proteins within cells, and of cells within organisms, respectively, and many stress pathways sequentially elicit autophagy, and apoptosis within the same cell. Generally autophagy blocks the induction of apoptosis, and apoptosis-associated caspase activation shuts off the autophagic process. However, in special cases, autophagy or autophagy-relevant proteins may help to induce apoptosis or necrosis, and autophagy has been shown to degrade the cytoplasm excessively, leading to 'autophagic cell death'. The dialogue between autophagy and cell death pathways influences the normal clearance of dying cells, as well as immune recognition of dead cell antigens. Therefore, the disruption of the relationship between autophagy and apoptosis has important pathophysiological consequences.
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Affiliation(s)
- Guillermo Mariño
- 1] Institut national de la santé et de la recherche médicale (INSERM), U1138, F-94805 Villejuif, France. [2] Université Paris Descartes/Paris V, Sorbonne Paris Cité, F-75006 Paris, France
| | - Mireia Niso-Santano
- 1] Institut national de la santé et de la recherche médicale (INSERM), U1138, F-94805 Villejuif, France. [2] Université Paris Descartes/Paris V, Sorbonne Paris Cité, F-75006 Paris, France
| | - Eric H Baehrecke
- Department of Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Guido Kroemer
- 1] Institut national de la santé et de la recherche médicale (INSERM), U1138, F-94805 Villejuif, France. [2] Université Paris Descartes/Paris V, Sorbonne Paris Cité, F-75006 Paris, France. [3] Equipe 11 labellisée par la Ligue Nationale contre le Cancer, Centre de Recherche des Cordeliers, F-75006 Paris, France. [4] Pôle de Biologie, Hôpital Européen Georges Pompidou, AP-HP, F-75015 Paris. [5] Metabolomics and Cell Biology Platforms, Institut Gustave Roussy, F-94805 Villejuif, France
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Abstract
Autophagy and apoptosis control the turnover of organelles and proteins within cells, and of cells within organisms, respectively, and many stress pathways sequentially elicit autophagy, and apoptosis within the same cell. Generally autophagy blocks the induction of apoptosis, and apoptosis-associated caspase activation shuts off the autophagic process. However, in special cases, autophagy or autophagy-relevant proteins may help to induce apoptosis or necrosis, and autophagy has been shown to degrade the cytoplasm excessively, leading to 'autophagic cell death'. The dialogue between autophagy and cell death pathways influences the normal clearance of dying cells, as well as immune recognition of dead cell antigens. Therefore, the disruption of the relationship between autophagy and apoptosis has important pathophysiological consequences.
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Nollet M, Santucci-Darmanin S, Breuil V, Al-Sahlanee R, Cros C, Topi M, Momier D, Samson M, Pagnotta S, Cailleteau L, Battaglia S, Farlay D, Dacquin R, Barois N, Jurdic P, Boivin G, Heymann D, Lafont F, Lu SS, Dempster DW, Carle GF, Pierrefite-Carle V. Autophagy in osteoblasts is involved in mineralization and bone homeostasis. Autophagy 2014; 10:1965-77. [PMID: 25484092 PMCID: PMC4502694 DOI: 10.4161/auto.36182] [Citation(s) in RCA: 281] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Bone remodeling is a tightly controlled mechanism in which osteoblasts (OB), the cells responsible for bone formation, osteoclasts (OC), the cells specialized for bone resorption, and osteocytes, the multifunctional mechanosensing cells embedded in the bone matrix, are the main actors. Increased oxidative stress in OB, the cells producing and mineralizing bone matrix, has been associated with osteoporosis development but the role of autophagy in OB has not yet been addressed. This is the goal of the present study. We first show that the autophagic process is induced in OB during mineralization. Then, using knockdown of autophagy-essential genes and OB-specific autophagy-deficient mice, we demonstrate that autophagy deficiency reduces mineralization capacity. Moreover, our data suggest that autophagic vacuoles could be used as vehicles in OB to secrete apatite crystals. In addition, autophagy-deficient OB exhibit increased oxidative stress and secretion of the receptor activator of NFKB1 (TNFSF11/RANKL), favoring generation of OC, the cells specialized in bone resorption. In vivo, we observed a 50% reduction in trabecular bone mass in OB-specific autophagy-deficient mice. Taken together, our results show for the first time that autophagy in OB is involved both in the mineralization process and in bone homeostasis. These findings are of importance for mineralized tissues which extend from corals to vertebrates and uncover new therapeutic targets for calcified tissue-related metabolic pathologies.
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Key Words
- ACP5/TRAP, acid phosphatase 5, tartrate resistant
- BECN1, Beclin 1, autophagy-related
- BV, bone volume
- Baf, bafilomycin A1
- Col1A, collagen, type I, α 1
- HRTEM, high resolution transmission electron microscopy
- MAP1LC3 (LC3), microtubule-associated protein 1 light chain 3
- OB, osteoblast
- OC, osteoclast
- PBS, phosphate-buffered saline
- RNA, ribonucleic acid
- RUNX2, runt-related transcription factor 2
- SAED, selected area electron diffraction
- SPP1/OPN, secreted phosphoprotein 1
- TNFSF11/RANKL, tumor necrosis factor (ligand) superfamily, member 11
- TUBB, tubulin, beta
- TV, total volume
- autophagy
- bone remodeling
- mineralization
- osteoblast
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Affiliation(s)
- Marie Nollet
- UMR E-4320 MATOs CEA/iBEB/SBTN-CAL; Université Nice Sophia Antipolis; Faculté de Médecine; Nice, France
| | - Sabine Santucci-Darmanin
- UMR E-4320 MATOs CEA/iBEB/SBTN-CAL; Université Nice Sophia Antipolis; Faculté de Médecine; Nice, France
| | - Véronique Breuil
- UMR E-4320 MATOs CEA/iBEB/SBTN-CAL; Université Nice Sophia Antipolis; Faculté de Médecine; Nice, France
- Service de Rhumatologie; CHU de Nice; Nice, France
| | - Rasha Al-Sahlanee
- UMR E-4320 MATOs CEA/iBEB/SBTN-CAL; Université Nice Sophia Antipolis; Faculté de Médecine; Nice, France
| | - Chantal Cros
- UMR E-4320 MATOs CEA/iBEB/SBTN-CAL; Université Nice Sophia Antipolis; Faculté de Médecine; Nice, France
| | - Majlinda Topi
- UMR E-4320 MATOs CEA/iBEB/SBTN-CAL; Université Nice Sophia Antipolis; Faculté de Médecine; Nice, France
| | - David Momier
- UMR E-4320 MATOs CEA/iBEB/SBTN-CAL; Université Nice Sophia Antipolis; Faculté de Médecine; Nice, France
| | - Michel Samson
- UMR E-4320 MATOs CEA/iBEB/SBTN-CAL; Université Nice Sophia Antipolis; Faculté de Médecine; Nice, France
| | - Sophie Pagnotta
- Centre Commun de Microscopie Appliquee; Université Nice Sophia Antipolis; Nice, France
| | - Laurence Cailleteau
- Plateforme Imagerie IRCAN; Faculté de Médecine; Université Nice Sophia Antipolis; Nice, France
| | - Séverine Battaglia
- INSERM UMR 957; Université de Nantes; Equipe labellisée Ligue Nationale Contre le Cancer 2012; Nantes, France
| | | | - Romain Dacquin
- Institut de Génomique Fonctionnelle de Lyon; Université de Lyon; CNRS; Ecole Normale Supérieure de Lyon; Lyon, France
| | - Nicolas Barois
- Plate-forme BICeL-IFR142; Institut Pasteur de Lille; Lille, France
| | - Pierre Jurdic
- Institut de Génomique Fonctionnelle de Lyon; Université de Lyon; CNRS; Ecole Normale Supérieure de Lyon; Lyon, France
| | | | - Dominique Heymann
- INSERM UMR 957; Université de Nantes; Equipe labellisée Ligue Nationale Contre le Cancer 2012; Nantes, France
| | - Frank Lafont
- Plate-forme BICeL-IFR142; Institut Pasteur de Lille; Lille, France
- INSERM U1019 - CNRS UMR 8204; Institut Pasteur de Lille - Univ Lille Nord de France; Lille, France
| | - Shi Shou Lu
- Regional Bone Center; Helen Hayes Hospital; West Havertsraw, NY USA
| | - David W Dempster
- Regional Bone Center; Helen Hayes Hospital; West Havertsraw, NY USA
| | - Georges F Carle
- UMR E-4320 MATOs CEA/iBEB/SBTN-CAL; Université Nice Sophia Antipolis; Faculté de Médecine; Nice, France
| | - Valérie Pierrefite-Carle
- UMR E-4320 MATOs CEA/iBEB/SBTN-CAL; Université Nice Sophia Antipolis; Faculté de Médecine; Nice, France
- Correspondence to: Valérie Pierrefite-Carle;
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Torisu T, Torisu K, Lee IH, Liu J, Malide D, Combs CA, Wu XS, Rovira II, Fergusson MM, Weigert R, Connelly PS, Daniels MP, Komatsu M, Cao L, Finkel T. Autophagy regulates endothelial cell processing, maturation and secretion of von Willebrand factor. Nat Med 2013; 19:1281-7. [PMID: 24056772 PMCID: PMC3795899 DOI: 10.1038/nm.3288] [Citation(s) in RCA: 196] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Accepted: 06/28/2013] [Indexed: 02/06/2023]
Abstract
Endothelial secretion of von Willebrand factor (VWF) from intracellular organelles known as Weibel-Palade bodies (WPBs) is required for platelet adhesion to the injured vessel wall. Here we demonstrate that WPBs are often found near or within autophagosomes and that endothelial autophagosomes contain abundant VWF protein. Pharmacological inhibitors of autophagy or knockdown of the essential autophagy genes Atg5 or Atg7 inhibits the in vitro secretion of VWF. Furthermore, although mice with endothelial-specific deletion of Atg7 have normal vessel architecture and capillary density, they exhibit impaired epinephrine-stimulated VWF release, reduced levels of high-molecular weight VWF multimers and a corresponding prolongation of bleeding times. Endothelial-specific deletion of Atg5 or pharmacological inhibition of autophagic flux results in a similar in vivo alteration of hemostasis. Thus, autophagy regulates endothelial VWF secretion, and transient pharmacological inhibition of autophagic flux may be a useful strategy to prevent thrombotic events.
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Affiliation(s)
- Takehiro Torisu
- Center for Molecular Medicine, NHLBI, NIH Bethesda, MD 20892
| | - Kumiko Torisu
- Center for Molecular Medicine, NHLBI, NIH Bethesda, MD 20892
| | - In Hye Lee
- Center for Molecular Medicine, NHLBI, NIH Bethesda, MD 20892
| | - Jie Liu
- Center for Molecular Medicine, NHLBI, NIH Bethesda, MD 20892
| | | | | | - Xufeng S. Wu
- Cell Biology and Physiology Center, NHLBI, NIH Bethesda, MD 20892
| | - Ilsa I. Rovira
- Center for Molecular Medicine, NHLBI, NIH Bethesda, MD 20892
| | | | - Roberto Weigert
- Intracellular Membrane Trafficking Unit, NIDCR, NIH Bethesda, MD 20892
| | | | - Mathew P Daniels
- Electron Microscopy Core Facility, NHLBI, NIH , Bethesda, MD 20892, USA
| | - Masaaki Komatsu
- Laboratory of Frontier Science, Tokyo Metropolitan Institute of Medical Sciences, Tokyo, Japan
| | - Liu Cao
- Key Laboratory of Medical Cell Biology, China Medical University, Shengyang, 110001, China
| | - Toren Finkel
- Center for Molecular Medicine, NHLBI, NIH Bethesda, MD 20892
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Ferrati S, McConnell KI, Mack AC, Sirisaengtaksin N, Diaz R, Bean AJ, Ferrari M, Serda RE. Cellular communication via nanoparticle-transporting biovesicles. Nanomedicine (Lond) 2013; 9:581-592. [PMID: 23731456 DOI: 10.2217/nnm.13.57] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
AIMS Endothelial cells are dynamic cells tasked with selective transport of cargo from blood vessels to tissues. Here we demonstrate the potential for nanoparticle transport across endothelial cells in membrane-bound vesicles. MATERIALS & METHODS Cell-free endothelial-derived biovesicles were characterized for cellular and nanoparticle content by electron microscopy. Confocal microscopy was used to evaluate biovesicles for organelle-specific proteins, and to monitor biovesicle engulfment by naive cells. RESULTS Nanoparticle-laden biovesicles containing low-density polyethyleneimine nanoparticles appear to be predominately of endosomal origin, combining features of multivesicular bodies, lysosomes and autophagosomes. Conversely, high-density polyethyleneimine nanoparticles stimulate the formation of biovesicles associated with cellular apoptotic breakdown. Secreted LAMP-1-positive biovesicles are internalized by recipient cells, either of the same origin or of novel phenotype. CONCLUSION Cellular biovesicles, rich in cellular signals, present an important mode of cell-to-cell communication either locally or through broadcasting of biological messages.
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Affiliation(s)
- Silvia Ferrati
- Department of Nanomedicine, The Methodist Hospital Research Institute, 6670 Bertner Avenue, R7-414, Houston, TX 77030, USA
| | - Kellie I McConnell
- Department of Nanomedicine, The Methodist Hospital Research Institute, 6670 Bertner Avenue, R7-414, Houston, TX 77030, USA
| | - Aaron C Mack
- Department of Nanomedicine, The Methodist Hospital Research Institute, 6670 Bertner Avenue, R7-414, Houston, TX 77030, USA
| | | | - Rodrigo Diaz
- Department of Nanomedicine, The Methodist Hospital Research Institute, 6670 Bertner Avenue, R7-414, Houston, TX 77030, USA
| | - Andrew J Bean
- Department of Neurobiology & Anatomy, University of Texas Medical School, Houston, TX, USA.,Department of Pediatrics, MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Mauro Ferrari
- Department of Nanomedicine, The Methodist Hospital Research Institute, 6670 Bertner Avenue, R7-414, Houston, TX 77030, USA
| | - Rita E Serda
- Department of Nanomedicine, The Methodist Hospital Research Institute, 6670 Bertner Avenue, R7-414, Houston, TX 77030, USA
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Sollberger G, Strittmatter GE, Garstkiewicz M, Sand J, Beer HD. Caspase-1: the inflammasome and beyond. Innate Immun 2013; 20:115-25. [PMID: 23676582 DOI: 10.1177/1753425913484374] [Citation(s) in RCA: 163] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Caspase-1 plays a fundamental role in innate immunity and in several important inflammatory diseases as the protease activates the pro-inflammatory cytokines proIL-1β and proIL-18. Caspase-1 itself is activated in different inflammasome complexes, which assemble in response to a variety of exogenous and endogenous stressors. More recently, pyroptosis, a caspase-1-dependent type of programmed cell death, has been identified that is able to support secreted IL-1 and IL-18 in triggering an inflammatory response. Whereas these 'canonical' activities are well appreciated, this review also highlights less-known pathways and molecules activated by caspase-1. There is evidence that caspase-1 supports cell survival by activation of NF-κB, induction of membrane repair and regulation of unconventional secretion of certain proteins. The physiologic effects of processing of other downstream targets, such as proteins involved in glycolysis or activation of caspase-7, are less well understood. However, there is increasing evidence that caspase-1 contributes to innate and adaptive immunologic defense mechanisms, repair and pathologic conditions by the regulation of several different and partially opposing pathways.
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Affiliation(s)
- Gabriel Sollberger
- Department of Dermatology, University Hospital Zürich, Zürich, Switzerland
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Ejlerskov P, Rasmussen I, Nielsen TT, Bergström AL, Tohyama Y, Jensen PH, Vilhardt F. Tubulin polymerization-promoting protein (TPPP/p25α) promotes unconventional secretion of α-synuclein through exophagy by impairing autophagosome-lysosome fusion. J Biol Chem 2013; 288:17313-35. [PMID: 23629650 DOI: 10.1074/jbc.m112.401174] [Citation(s) in RCA: 164] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Aggregation of α-synuclein can be promoted by the tubulin polymerization-promoting protein/p25α, which we have used here as a tool to study the role of autophagy in the clearance of α-synuclein. In NGF-differentiated PC12 catecholaminergic nerve cells, we show that de novo expressed p25α co-localizes with α-synuclein and causes its aggregation and distribution into autophagosomes. However, p25α also lowered the mobility of autophagosomes and hindered the final maturation of autophagosomes by preventing their fusion with lysosomes for the final degradation of α-synuclein. Instead, p25α caused a 4-fold increase in the basal level of α-synuclein secreted into the medium. Secretion was strictly dependent on autophagy and could be up-regulated (trehalose and Rab1A) or down-regulated (3-methyladenine and ATG5 shRNA) by enhancers or inhibitors of autophagy or by modulating minus-end-directed (HDAC6 shRNA) or plus-end-directed (Rab8) trafficking of autophagosomes along microtubules. Finally, we show in the absence of tubulin polymerization-promoting protein/p25α that α-synuclein release was modulated by dominant mutants of Rab27A, known to regulate exocytosis of late endosomal (and amphisomal) elements, and that both lysosomal fusion block and secretion of α-synuclein could be replicated by knockdown of the p25α target, HDAC6, the predominant cytosolic deacetylase in neurons. Our data indicate that unconventional secretion of α-synuclein can be mediated through exophagy and that factors, which increase the pool of autophagosomes/amphisomes (e.g. lysosomal disturbance) or alter the polarity of vesicular transport of autophagosomes on microtubules, can result in an increased release of α-synuclein monomer and aggregates to the surroundings.
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Affiliation(s)
- Patrick Ejlerskov
- Department of Cellular and Molecular Medicine, The Panum Institute, University of Copenhagen, 2200 Copenhagen N, Denmark
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Drakakaki G, Dandekar A. Protein secretion: how many secretory routes does a plant cell have? PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2013; 203-204:74-8. [PMID: 23415330 DOI: 10.1016/j.plantsci.2012.12.017] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Revised: 12/18/2012] [Accepted: 12/26/2012] [Indexed: 05/19/2023]
Abstract
Conventional protein secretion is mediated by the endomembrane system. Secreted proteins are inserted into the endomembrane system through a N-terminal signal peptide and follow the endoplasmic reticulum to the Golgi trafficking pathway en route to the plasma membrane or the extracellular apoplastic space. In mammalian and yeast cells, unconventional secretion has been identified and relatively well studied. Also in plants, evidence of unconventional secretion mechanisms is accumulating. The ever-increasing number of leaderless proteins identified in proteomic studies indicates the importance of unconventional protein secretion in plants. Novel approaches, such as chemical genomics and vesicle proteomics might be able to provide new insights into unconventional protein secretion in plants.
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Affiliation(s)
- Georgia Drakakaki
- Department of Plant Sciences, University of California, Davis 95616, USA
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Abstract
UNLABELLED When microbes contaminate the macrophage cytoplasm, leukocytes undergo a proinflammatory death that is initiated by nucleotide-binding-domain-, leucine-rich-repeat-containing proteins (NLR proteins) that bind and activate caspase-1. We report that these inflammasome components also regulate autophagy, a vesicular pathway to eliminate cytosolic debris. In response to infection with flagellate Legionella pneumophila, C57BL/6J mouse macrophages equipped with caspase-1 and the NLR proteins NAIP5 and NLRC4 stimulated autophagosome turnover. A second trigger of inflammasome assembly, K(+) efflux, also rapidly activated autophagy in macrophages that produced caspase-1. Autophagy protects infected macrophages from pyroptosis, since caspase-1-dependent cell death occurred more frequently when autophagy was dampened pharmacologically by either 3-methyladenine or an inhibitor of the Atg4 protease. Accordingly, in addition to coordinating pyroptosis, both (pro-) caspase-1 protein and NLR components of inflammasomes equip macrophages to recruit autophagy, a disposal pathway that raises the threshold of contaminants necessary to trigger proinflammatory leukocyte death. IMPORTANCE An exciting development in the innate-immunity field is the recognition that macrophages enlist autophagy to protect their cytoplasm from infection. Nutrient deprivation has long been known to induce autophagy; how infection triggers this disposal pathway is an active area of research. Autophagy is encountered by many of the intracellular pathogens that are known to trigger pyroptosis, an inflammatory cell death initiated when nucleotide-binding-domain-, leucine-rich-repeat-containing proteins (NLR proteins) activate caspase-1 within inflammasome complexes. Therefore, we tested the hypothesis that NLR proteins and caspase-1 also coordinate autophagy as a barrier to cytosolic infection. By exploiting classical bacterial and mouse genetics and kinetic assays of autophagy, we demonstrate for the first time that, when confronted with cytosolic contamination, primary mouse macrophages rely not only on the NLR proteins NAIP5 and NLRC4 but also on (pro-)caspase-1 protein to mount a rapid autophagic response that wards off proinflammatory cell death.
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48
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Subramani S, Malhotra V. Non-autophagic roles of autophagy-related proteins. EMBO Rep 2013; 14:143-51. [PMID: 23337627 PMCID: PMC3566844 DOI: 10.1038/embor.2012.220] [Citation(s) in RCA: 204] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Accepted: 12/10/2012] [Indexed: 01/10/2023] Open
Abstract
Autophagy and autophagy-related processes are fundamentally important in human health and disease. These processes are viewed primarily as cellular degradative pathways that recycle macromolecules and dysfunctional or redundant organelles into amino acids, sugars and lipids, especially during starvation. However, the ubiquitin-like autophagy proteins and other components of the autophagic machinery additionally participate in cellular reprogramming. We highlight these non-autophagic roles of autophagy proteins with the aim of drawing attention to this growing, but unexplored, research topic. We focus on the non-autophagic functions of autophagy proteins in cell survival and apoptosis, modulation of cellular traffic, protein secretion, cell signalling, transcription, translation and membrane reorganization.
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Affiliation(s)
- Suresh Subramani
- Section of Molecular Biology, Division of Biological Sciences, University of California, San Diego, California 92093-0322, USA.
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Pietrella D, Pandey N, Gabrielli E, Pericolini E, Perito S, Kasper L, Bistoni F, Cassone A, Hube B, Vecchiarelli A. Secreted aspartic proteases of Candida albicans activate the NLRP3 inflammasome. Eur J Immunol 2013; 43:679-92. [PMID: 23280543 DOI: 10.1002/eji.201242691] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Revised: 12/06/2012] [Accepted: 12/20/2012] [Indexed: 01/12/2023]
Abstract
In a recent report, we demonstrated that distinct members of the secreted aspartic protease (Sap) family of Candida albicans are able to induce secretion of proinflammatory cytokines by human monocytes, independently of their proteolytic activity and specific pH optima. In particular, C. albicans Sap2 and Sap6 potently induced IL-1β, TNF-α, and IL-6 production. Here, we demonstrate that Sap2 and Sap6 proteins trigger IL-1β and IL-18 production through inflammasome activation. This occurs via NLRP3 and caspase-1 activation, which cleaves pro-IL-1β into secreted bioactive IL-1β, a cytokine that was induced by Saps in monocytes, in monocyte-derived macrophages and in dendritic cells. Downregulation of NLRP3 by RNA interference strongly reduced the secretion of bioactive IL-1β. Inflammasome activation required Sap internalization via a clathrin-dependent mechanism, intracellular induction of K(+) efflux, and ROS production. Inflammasome activation of monocytes induced by Sap2 and Sap6 differed from that induced by LPS-ATP in several aspects. Our data reveal novel immunoregulatory mechanisms of C. albicans and suggest that Saps contribute to the pathogenesis of candidiasis by fostering rather than evading host immunity.
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Affiliation(s)
- Donatella Pietrella
- Microbiology Section, Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Perugia, Italy
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Bayer-Santos E, Aguilar-Bonavides C, Rodrigues SP, Cordero EM, Marques AF, Varela-Ramirez A, Choi H, Yoshida N, da Silveira JF, Almeida IC. Proteomic Analysis of Trypanosoma cruzi Secretome: Characterization of Two Populations of Extracellular Vesicles and Soluble Proteins. J Proteome Res 2013; 12:883-97. [DOI: 10.1021/pr300947g] [Citation(s) in RCA: 181] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Ethel Bayer-Santos
- Departamento de Microbiologia,
Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo, SP 04023-062, Brazil
| | - Clemente Aguilar-Bonavides
- The Border Biomedical Research
Center, Department of Biological Sciences, University of Texas at El Paso, El Paso, Texas 79968, United States
- Computational Science Program,
The Border Biomedical Research Center, University of Texas at El Paso, El Paso, Texas 79968, United States
| | - Silas Pessini Rodrigues
- The Border Biomedical Research
Center, Department of Biological Sciences, University of Texas at El Paso, El Paso, Texas 79968, United States
| | - Esteban Maurício Cordero
- The Border Biomedical Research
Center, Department of Biological Sciences, University of Texas at El Paso, El Paso, Texas 79968, United States
| | - Alexandre Ferreira Marques
- The Border Biomedical Research
Center, Department of Biological Sciences, University of Texas at El Paso, El Paso, Texas 79968, United States
| | - Armando Varela-Ramirez
- The Border Biomedical Research
Center, Department of Biological Sciences, University of Texas at El Paso, El Paso, Texas 79968, United States
| | - Hyungwon Choi
- Saw Swee Hock School of Public
Health, National University of Singapore, Singapore
| | - Nobuko Yoshida
- Departamento de Microbiologia,
Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo, SP 04023-062, Brazil
| | - José Franco da Silveira
- Departamento de Microbiologia,
Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo, SP 04023-062, Brazil
| | - Igor C. Almeida
- The Border Biomedical Research
Center, Department of Biological Sciences, University of Texas at El Paso, El Paso, Texas 79968, United States
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