1
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Chaudhry N, Sica M, Surabhi S, Hernandez DS, Mesquita A, Selimovic A, Riaz A, Lescat L, Bai H, MacIntosh GC, Jenny A. Lamp1 mediates lipid transport, but is dispensable for autophagy in Drosophila. Autophagy 2022; 18:2443-2458. [PMID: 35266854 PMCID: PMC9542896 DOI: 10.1080/15548627.2022.2038999] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 01/31/2022] [Accepted: 02/03/2022] [Indexed: 01/03/2023] Open
Abstract
The endolysosomal system not only is an integral part of the cellular catabolic machinery that processes and recycles nutrients for synthesis of biomaterials, but also acts as signaling hub to sense and coordinate the energy state of cells with growth and differentiation. Lysosomal dysfunction adversely influences vesicular transport-dependent macromolecular degradation and thus causes serious problems for human health. In mammalian cells, loss of the lysosome associated membrane proteins LAMP1 and LAMP2 strongly affects autophagy and cholesterol trafficking. Here we show that the previously uncharacterized Drosophila Lamp1 is a bona fide ortholog of vertebrate LAMP1 and LAMP2. Surprisingly and in contrast to lamp1 lamp2 double-mutant mice, Drosophila Lamp1 is not required for viability or autophagy, suggesting that fly and vertebrate LAMP proteins acquired distinct functions, or that autophagy defects in lamp1 lamp2 mutants may have indirect causes. However, Lamp1 deficiency results in an increase in the number of acidic organelles in flies. Furthermore, we find that Lamp1 mutant larvae have defects in lipid metabolism as they show elevated levels of sterols and diacylglycerols (DAGs). Because DAGs are the main lipid species used for transport through the hemolymph (blood) in insects, our results indicate broader functions of Lamp1 in lipid transport. Our findings make Drosophila an ideal model to study the role of LAMP proteins in lipid assimilation without the confounding effects of their storage and without interfering with autophagic processes.Abbreviations: aa: amino acid; AL: autolysosome; AP: autophagosome; APGL: autophagolysosome; AV: autophagic vacuole (i.e. AP and APGL/AL); AVi: early/initial autophagic vacuoles; AVd: late/degradative autophagic vacuoles; Atg: autophagy-related; CMA: chaperone-mediated autophagy; Cnx99A: Calnexin 99A; DAG: diacylglycerol; eMI: endosomal microautophagy; ESCRT: endosomal sorting complexes required for transport; FB: fat body; HDL: high-density lipoprotein; Hrs: Hepatocyte growth factor regulated tyrosine kinase substrate; LAMP: lysosomal associated membrane protein; LD: lipid droplet; LDL: low-density lipoprotein; Lpp: lipophorin; LTP: Lipid transfer particle; LTR: LysoTracker Red; MA: macroautophagy; MCC: Manders colocalization coefficient; MEF: mouse embryonic fibroblast MTORC: mechanistic target of rapamycin kinase complex; PV: parasitophorous vacuole; SNARE: soluble N-ethylmaleimide sensitive factor attachment protein receptor; Snap: Synaptosomal-associated protein; st: starved; TAG: triacylglycerol; TEM: transmission electron microscopy; TFEB/Mitf: transcription factor EB; TM: transmembrane domain; tub: tubulin; UTR: untranslated region.
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Affiliation(s)
- Norin Chaudhry
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, USA
| | - Margaux Sica
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, USA
| | - Satya Surabhi
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, USA
| | | | - Ana Mesquita
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, USA
| | - Adem Selimovic
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, USA
| | - Ayesha Riaz
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, USA
| | - Laury Lescat
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, USA
| | - Hua Bai
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, USA
| | - Gustavo C. MacIntosh
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, USA
| | - Andreas Jenny
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, USA
- Department of Genetics, Albert Einstein College of MedicineNew York, NY, USA
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2
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Cunningham KM, Maulding K, Ruan K, Senturk M, Grima JC, Sung H, Zuo Z, Song H, Gao J, Dubey S, Rothstein JD, Zhang K, Bellen HJ, Lloyd TE. TFEB/Mitf links impaired nuclear import to autophagolysosomal dysfunction in C9-ALS. eLife 2020; 9:59419. [PMID: 33300868 PMCID: PMC7758070 DOI: 10.7554/elife.59419] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 12/09/2020] [Indexed: 12/13/2022] Open
Abstract
Disrupted nucleocytoplasmic transport (NCT) has been implicated in neurodegenerative disease pathogenesis; however, the mechanisms by which disrupted NCT causes neurodegeneration remain unclear. In a Drosophila screen, we identified ref(2)P/p62, a key regulator of autophagy, as a potent suppressor of neurodegeneration caused by the GGGGCC hexanucleotide repeat expansion (G4C2 HRE) in C9orf72 that causes amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). We found that p62 is increased and forms ubiquitinated aggregates due to decreased autophagic cargo degradation. Immunofluorescence and electron microscopy of Drosophila tissues demonstrate an accumulation of lysosome-like organelles that precedes neurodegeneration. These phenotypes are partially caused by cytoplasmic mislocalization of Mitf/TFEB, a key transcriptional regulator of autophagolysosomal function. Additionally, TFEB is mislocalized and downregulated in human cells expressing GGGGCC repeats and in C9-ALS patient motor cortex. Our data suggest that the C9orf72-HRE impairs Mitf/TFEB nuclear import, thereby disrupting autophagy and exacerbating proteostasis defects in C9-ALS/FTD.
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Affiliation(s)
- Kathleen M Cunningham
- Cellular and Molecular Medicine Program, School of Medicine, Johns Hopkins University, Baltimore, United States
| | - Kirstin Maulding
- Cellular and Molecular Medicine Program, School of Medicine, Johns Hopkins University, Baltimore, United States
| | - Kai Ruan
- Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, United States
| | - Mumine Senturk
- Program in Developmental Biology, Baylor College of Medicine (BCM), Houston, United States
| | - Jonathan C Grima
- Brain Science Institute, School of Medicine, Johns Hopkins University, Baltimore, United States.,Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, United States
| | - Hyun Sung
- Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, United States
| | - Zhongyuan Zuo
- Department of Molecular and Human Genetics, BCM, Houston, United States
| | - Helen Song
- Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, United States
| | - Junli Gao
- Department of Neuroscience, Mayo Clinic, Jacksonville, United States
| | - Sandeep Dubey
- Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, United States
| | - Jeffrey D Rothstein
- Cellular and Molecular Medicine Program, School of Medicine, Johns Hopkins University, Baltimore, United States.,Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, United States.,Brain Science Institute, School of Medicine, Johns Hopkins University, Baltimore, United States.,Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, United States
| | - Ke Zhang
- Department of Neuroscience, Mayo Clinic, Jacksonville, United States
| | - Hugo J Bellen
- Program in Developmental Biology, Baylor College of Medicine (BCM), Houston, United States.,Department of Molecular and Human Genetics, BCM, Houston, United States.,Department of Neuroscience, BCM, Houston, United States.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, United States.,Howard Hughes Medical Institute, Houston, United States
| | - Thomas E Lloyd
- Cellular and Molecular Medicine Program, School of Medicine, Johns Hopkins University, Baltimore, United States.,Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, United States.,Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, United States
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3
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Injection of seminal fluid into the hemocoel of honey bee queens (Apis mellifera) can stimulate post-mating changes. Sci Rep 2020; 10:11990. [PMID: 32686702 PMCID: PMC7371693 DOI: 10.1038/s41598-020-68437-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 06/15/2020] [Indexed: 11/08/2022] Open
Abstract
Honey bee queens undergo dramatic behavioral (e.g., reduced sexual receptivity), physiological (e.g., ovary activation, ovulation, and modulation of pheromone production) and transcriptional changes after they complete mating. To elucidate how queen post-mating changes are influenced by seminal fluid, the non-spermatozoa-containing component of semen, we injected queens with semen or seminal fluid alone. We assessed queen sexual receptivity (as measured by likelihood to take mating flights), ovary activation, worker retinue response (which is influenced by queen pheromone production), and transcriptional changes in queen abdominal fat body and brain tissues. Injection with either seminal fluid or semen resulted in decreased sexual receptivity, increased attractiveness of queens to workers, and altered expression of several genes that are also regulated by natural mating in queens. The post-mating and transcriptional changes of queens receiving seminal fluid were not significantly different from queens injected with semen, suggesting that components in seminal fluid, such as seminal fluid proteins, are largely responsible for stimulating post-mating changes in queens.
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4
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Abstract
Being originally discovered as cellular recycling bins, lysosomes are today recognized as versatile signaling organelles that control a wide range of cellular functions that are essential not only for the well-being of normal cells but also for malignant transformation and cancer progression. In addition to their core functions in waste disposal and recycling of macromolecules and energy, lysosomes serve as an indispensable support system for malignant phenotype by promoting cell growth, cytoprotective autophagy, drug resistance, pH homeostasis, invasion, metastasis, and genomic integrity. On the other hand, malignant transformation reduces the stability of lysosomal membranes rendering cancer cells sensitive to lysosome-dependent cell death. Notably, many clinically approved cationic amphiphilic drugs widely used for the treatment of other diseases accumulate in lysosomes, interfere with their cancer-promoting and cancer-supporting functions and destabilize their membranes thereby opening intriguing possibilities for cancer therapy. Here, we review the emerging evidence that supports the supplementation of current cancer therapies with lysosome-targeting cationic amphiphilic drugs.
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5
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Lee KM, Mathies LD, Grotewiel M. Alcohol sedation in adult Drosophila is regulated by Cysteine proteinase-1 in cortex glia. Commun Biol 2019; 2:252. [PMID: 31286069 PMCID: PMC6610072 DOI: 10.1038/s42003-019-0492-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 05/30/2019] [Indexed: 02/06/2023] Open
Abstract
Although numerous studies have demonstrated that neuronal mechanisms regulate alcohol-related behaviors, very few have investigated the direct role of glia in behavioral responses to alcohol. The results described here begin to fill this gap in the alcohol behavior and gliobiology fields. Since Drosophila exhibit conserved behavioral responses to alcohol and their CNS glia are similar to mammalian CNS glia, we used Drosophila to begin exploring the role of glia in alcohol behavior. We found that knockdown of Cysteine proteinase-1 (Cp1) in glia increased Drosophila alcohol sedation and that this effect was specific to cortex glia and adulthood. These data implicate Cp1 and cortex glia in alcohol-related behaviors. Cortex glia are functionally homologous to mammalian astrocytes and Cp1 is orthologous to mammalian Cathepsin L. Our studies raise the possibility that cathepsins may influence behavioral responses to alcohol in mammals via roles in astrocytes.
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Affiliation(s)
- Kristen M. Lee
- Neuroscience Graduate Program, Virginia Commonwealth University, Richmond, VA 23298 USA
| | - Laura D. Mathies
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA 23298 USA
- Virginia Commonwealth University Alcohol Research Center, Virginia Commonwealth University, Richmond, VA 23298 USA
| | - Mike Grotewiel
- Neuroscience Graduate Program, Virginia Commonwealth University, Richmond, VA 23298 USA
- Virginia Commonwealth University Alcohol Research Center, Virginia Commonwealth University, Richmond, VA 23298 USA
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, VA 23298 USA
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6
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Peyer SM, Kremer N, McFall‐Ngai MJ. Involvement of a host Cathepsin L in symbiont-induced cell death. Microbiologyopen 2018; 7:e00632. [PMID: 29692003 PMCID: PMC6182562 DOI: 10.1002/mbo3.632] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 03/01/2018] [Accepted: 03/01/2018] [Indexed: 02/06/2023] Open
Abstract
The cathepsin L gene of the host squid, Euprymna scolopes, is upregulated during the first hours of colonization by the symbiont Vibrio fischeri. At this time, the symbiotic organ begins cell death-mediated morphogenesis in tissues functional only at the onset of symbiosis. The goal of this study was to determine whether Cathepsin L, a cysteine protease associated with apoptosis in other animals, plays a critical role in symbiont-induced cell death in the host squid. Sequence analysis and biochemical characterization demonstrated that the protein has key residues and domains essential for Cathepsin L function and that it is active within the pH range typical of these proteases. With in situ hybridization and immunocytochemistry, we localized the transcript and protein, respectively, to cells interacting with V. fischeri. Activity of the protein occurred along the path of symbiont colonization. A specific Cathepsin L, nonspecific cysteine protease, and caspase inhibitor each independently attenuated activity and cell death to varying degrees. In addition, a specific antibody decreased cell death by ~50%. Together these data provide evidence that Cathepsin L is a critical component in the symbiont-induced cell death that transforms the host tissues from a colonization morphology to one that promotes the mature association.
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Affiliation(s)
- Suzanne M. Peyer
- School of Medicine and Public HealthDepartment of Medical Microbiology and ImmunologyUniversity of WisconsinMadisonWIUSA
- McPherson Eye Research InstituteUniversity of WisconsinMadisonWIUSA
| | - Natacha Kremer
- School of Medicine and Public HealthDepartment of Medical Microbiology and ImmunologyUniversity of WisconsinMadisonWIUSA
- Present address:
Laboratoire de Biométrie et Biologie EvolutiveUMR CNRS 5558Université Lyon 1Université de LyonVilleurbanneFrance
| | - Margaret J. McFall‐Ngai
- School of Medicine and Public HealthDepartment of Medical Microbiology and ImmunologyUniversity of WisconsinMadisonWIUSA
- McPherson Eye Research InstituteUniversity of WisconsinMadisonWIUSA
- Present address:
Pacific Biosciences Research CenterUniversity of Hawai'i at ManoaHonoluluHIUSA
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7
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Jin EJ, Kiral FR, Ozel MN, Burchardt LS, Osterland M, Epstein D, Wolfenberg H, Prohaska S, Hiesinger PR. Live Observation of Two Parallel Membrane Degradation Pathways at Axon Terminals. Curr Biol 2018; 28:1027-1038.e4. [PMID: 29551411 PMCID: PMC5944365 DOI: 10.1016/j.cub.2018.02.032] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 01/24/2018] [Accepted: 02/14/2018] [Indexed: 01/04/2023]
Abstract
Neurons are highly polarized cells that require continuous turnover of membrane proteins at axon terminals to develop, function, and survive. Yet, it is still unclear whether membrane protein degradation requires transport back to the cell body or whether degradation also occurs locally at the axon terminal, where live observation of sorting and degradation has remained a challenge. Here, we report direct observation of two cargo-specific membrane protein degradation mechanisms at axon terminals based on a live-imaging approach in intact Drosophila brains. We show that different acidification-sensing cargo probes are sorted into distinct classes of degradative “hub” compartments for synaptic vesicle proteins and plasma membrane proteins at axon terminals. Sorting and degradation of the two cargoes in the separate hubs are molecularly distinct. Local sorting of synaptic vesicle proteins for degradation at the axon terminal is, surprisingly, Rab7 independent, whereas sorting of plasma membrane proteins is Rab7 dependent. The cathepsin-like protease CP1 is specific to synaptic vesicle hubs, and its delivery requires the vesicle SNARE neuronal synaptobrevin. Cargo separation only occurs at the axon terminal, whereas degradative compartments at the cell body are mixed. These data show that at least two local, molecularly distinct pathways sort membrane cargo for degradation specifically at the axon terminal, whereas degradation can occur both at the terminal and en route to the cell body.
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Affiliation(s)
- Eugene Jennifer Jin
- Division of Neurobiology, Freie Universität Berlin, Königin Luise Straße 1-3, 14195 Berlin, Germany; Graduate School of Biomedical Sciences, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Ferdi Ridvan Kiral
- Division of Neurobiology, Freie Universität Berlin, Königin Luise Straße 1-3, 14195 Berlin, Germany
| | - Mehmet Neset Ozel
- Division of Neurobiology, Freie Universität Berlin, Königin Luise Straße 1-3, 14195 Berlin, Germany; Graduate School of Biomedical Sciences, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Lara Sophie Burchardt
- Division of Neurobiology, Freie Universität Berlin, Königin Luise Straße 1-3, 14195 Berlin, Germany
| | - Marc Osterland
- Zuse Institute Berlin, Takustraße 7, 14195 Berlin, Germany
| | - Daniel Epstein
- Division of Neurobiology, Freie Universität Berlin, Königin Luise Straße 1-3, 14195 Berlin, Germany
| | - Heike Wolfenberg
- Division of Neurobiology, Freie Universität Berlin, Königin Luise Straße 1-3, 14195 Berlin, Germany
| | | | - Peter Robin Hiesinger
- Division of Neurobiology, Freie Universität Berlin, Königin Luise Straße 1-3, 14195 Berlin, Germany.
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8
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Kang T, Jin R, Zhang Y, Wan H, Lee KS, Jin BR, Li J. Functional characterization of the aspartic proteinase cathepsin D in the beet armyworm (Spodoptera exigua). Gene 2017; 617:1-7. [PMID: 28351737 DOI: 10.1016/j.gene.2017.03.035] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2017] [Revised: 03/21/2017] [Accepted: 03/24/2017] [Indexed: 10/19/2022]
Abstract
In insects, proteolytic enzymes are involved in food digestion and the metamorphosis process. In the present study, the full-length cDNA of an aspartic proteinase, Spodoptera exigua cathepsin D (SeCatD), was cloned, and its functions in metamorphosis were characterized. SeCatD contains an open reading frame of 1152 nucleotides, encoding a 384-amino acid polypeptide including a signal peptide and two functional domains (family A1 propeptide of amino acids (19-45) and a cathepsin D-like domain of 327 amino acids (55-381)). Three-dimensional structure analysis indicated that Asp66 and Asp251 may play important role in hydrolysis. Recombinant SeCatD was expressed in Sf9 insect cells and verified via SDS-PAGE and Western blot, the molecular mass of the expressed SeCatD was approximately 42kDa. The enzyme had an optimal pH value of 3 for activity. In addition, the tissue expression profile of SeCatD during metamorphosis was obtained, and the data demonstrated that SeCatD was expressed increasingly in the fat body and midgut, but not in the epidermis. Finally, injection of dsRNA-SeCatD into the fifth-instar larvae significantly reduced SeCatD expression and larvae survival rate compared to a dsRNA-GFP treatment. These data imply that SeCatD may function during metamorphosis and may represent a target for insect control.
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Affiliation(s)
- Tinghao Kang
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Ruoheng Jin
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Yunhua Zhang
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Hu Wan
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Kwang Sik Lee
- College of Natural Resources and Life Science, Dong-A University, Busan 604-714, Republic of Korea
| | - Byung Rae Jin
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China; College of Natural Resources and Life Science, Dong-A University, Busan 604-714, Republic of Korea.
| | - Jianhong Li
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China.
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9
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Chen H, Lv M, Lv Z, Li C, Xu W, Zhang W, Zhao X, Duan X, Jin C. Molecular cloning and functional characterization of cathepsin B from the sea cucumber Apostichopus japonicus. FISH & SHELLFISH IMMUNOLOGY 2017; 60:447-457. [PMID: 27847342 DOI: 10.1016/j.fsi.2016.11.033] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 11/08/2016] [Accepted: 11/12/2016] [Indexed: 06/06/2023]
Abstract
Cathepsin B (CTSB), a member of lysosomal cysteine protease, is involved in multiple levels of physiological and biological processes, and also plays crucial roles in host immune defense against pathogen infection in vertebrates. However, the function of CTSB within the innate immune system of invertebrates, particularly in marine echinoderms, has been poorly documented. In this study, the immune function of CTSB in Apostichopus japonicus (designated as AjCTSB), a commercially important and disease vulnerable aquaculture specie, was investigated by integrated molecular and protein approaches. A 2153 bp cDNA representing the full-length of AjCTSB was cloned via overlapping ESTs and RACE fragments. AjCTSB contained an open reading frame of 999 bp encoding a secreted protein of 332 amino acid residues with a predicted molecular mass of 36.8 kDa. The deduced amino acid of AjCTSB shared a typical activity center containing three conserved amino acid residues (Cys108, His277 and Asn297). Phylogenetic tree analysis also supported that AjCTSB was a new member of CTSB family with clustering firstly with invertebrate CTSBs. Quantitative real time PCR analysis revealed that AjCTSB was ubiquitously expressed in all examined tissues with the highest levels in intestine. The Vibrio splendidus challenged sea cucumber and LPS-exposed coelomocytes could both significantly boost the expression of AjCTSB. Moreover, the purified recombinant AjCTSB exhibited dose-dependent CTSB activities at the concentration ranged from 0 to 0.24 μg μL-1. Further functional analysis indicated that coelomocytes apoptosis was significantly inhibited by 0.16-fold in vivo and the apoptosis execution Ajcaspase 3 was extremely reduced in Apostichopus japonicus coelomocytes treated with specific AjCTSB siRNA. Collectively, all these results suggested that AjCTSB was an important immune factor and might be served as apoptosis enhancers in pathogen challenged sea cucumber.
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Affiliation(s)
- Huahui Chen
- School of Marine Sciences, Ningbo University, PR China
| | - Miao Lv
- School of Marine Sciences, Ningbo University, PR China
| | - Zhimeng Lv
- School of Marine Sciences, Ningbo University, PR China
| | - Chenghua Li
- School of Marine Sciences, Ningbo University, PR China.
| | - Wei Xu
- Louisiana State University, Agricultural Center, USA
| | - Weiwei Zhang
- School of Marine Sciences, Ningbo University, PR China
| | - Xuelin Zhao
- School of Marine Sciences, Ningbo University, PR China
| | - Xuemei Duan
- School of Marine Sciences, Ningbo University, PR China
| | - Chunhua Jin
- School of Marine Sciences, Ningbo University, PR China
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10
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Aits S, Kricker J, Liu B, Ellegaard AM, Hämälistö S, Tvingsholm S, Corcelle-Termeau E, Høgh S, Farkas T, Holm Jonassen A, Gromova I, Mortensen M, Jäättelä M. Sensitive detection of lysosomal membrane permeabilization by lysosomal galectin puncta assay. Autophagy 2016; 11:1408-24. [PMID: 26114578 DOI: 10.1080/15548627.2015.1063871] [Citation(s) in RCA: 285] [Impact Index Per Article: 35.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Lysosomal membrane permeabilization (LMP) contributes to tissue involution, degenerative diseases, and cancer therapy. Its investigation has, however, been hindered by the lack of sensitive methods. Here, we characterize and validate the detection of galectin puncta at leaky lysosomes as a highly sensitive and easily manageable assay for LMP. LGALS1/galectin-1 and LGALS3/galectin-3 are best suited for this purpose due to their widespread expression, rapid translocation to leaky lysosomes and availability of high-affinity antibodies. Galectin staining marks individual leaky lysosomes early during lysosomal cell death and is useful when defining whether LMP is a primary or secondary cause of cell death. This sensitive method also reveals that cells can survive limited LMP and confirms a rapid formation of autophagic structures at the site of galectin puncta. Importantly, galectin staining detects individual leaky lysosomes also in paraffin-embedded tissues allowing us to demonstrate LMP in tumor xenografts in mice treated with cationic amphiphilic drugs and to identify a subpopulation of lysosomes that initiates LMP in involuting mouse mammary gland. The use of ectopic fluorescent galectins renders the galectin puncta assay suitable for automated screening and visualization of LMP in live cells and animals. Thus, the lysosomal galectin puncta assay opens up new possibilities to study LMP in cell death and its role in other cellular processes such as autophagy, senescence, aging, and inflammation.
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Affiliation(s)
- Sonja Aits
- a Cell Death and Metabolism Unit; Center for Autophagy, Recycling and Disease; Danish Cancer Society Research Center ; Copenhagen , Denmark
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11
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Liu Y, Chen X, Xu Q, Gao X, Tam POS, Zhao K, Zhang X, Chen LJ, Jia W, Zhao Q, Vollrath D, Pang CP, Zhao C. SPP2 Mutations Cause Autosomal Dominant Retinitis Pigmentosa. Sci Rep 2015; 5:14867. [PMID: 26459573 PMCID: PMC4602186 DOI: 10.1038/srep14867] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 09/08/2015] [Indexed: 01/12/2023] Open
Abstract
Retinitis pigmentosa (RP) shows progressive loss of photoreceptors involved with heterogeneous genetic background. Here, by exome sequencing and linkage analysis on a Chinese family with autosomal dominant RP, we identified a putative pathogenic variant, p.Gly97Arg, in the gene SPP2, of which expression was detected in multiple tissues including retina. The p.Gly97Arg was absent in 800 ethnically matched chromosomes and 1400 in-house exome dataset, and was located in the first of the two highly conserved disulfide bonded loop of secreted phosphoprotein 2 (Spp-24) encoded by SPP2. Overexpression of p.Gly97Arg and another signal peptide mutation, p.Gly29Asp, caused cellular retention of both endogenous wild type and exogenous mutants in vitro, and primarily affected rod photoreceptors in zebrafish mimicking cardinal feature of RP. Taken together, our data indicate that the two mutations of SPP2 have dominant negative effects and cellular accumulation of Spp-24 might be particularly toxic to photoreceptors and/or retinal pigment epithelium. SPP2 has a new role in retinal degeneration.
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Affiliation(s)
- Yuan Liu
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University and State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 210029, China
| | - Xue Chen
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University and State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 210029, China
| | - Qihua Xu
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University and State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 210029, China.,Department of Ophthalmology, The Affiliated Jiangyin Hospital of Southeast University Medical College, Jiangyin, China
| | - Xiang Gao
- Department of Ophthalmology, School of Medicine, Henan Polytechnic University, Henan 454150, China
| | - Pancy O S Tam
- Department of Ophthalmology &Visual Sciences, The Chinese University of Hong Kong, Hong Kong
| | - Kanxing Zhao
- Tianjin Medical University, Tianjin Eye Hospital, Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin 300040, China
| | - Xiumei Zhang
- Department of Ophthalmology, School of Medicine, Henan Polytechnic University, Henan 454150, China
| | - Li Jia Chen
- Department of Ophthalmology &Visual Sciences, The Chinese University of Hong Kong, Hong Kong
| | - Wenshuang Jia
- Model Animal Research Center, MOE Key Laboratory of Model Animal for Disease Study, Nanjing University, Nanjing 210061, China
| | - Qingshun Zhao
- Model Animal Research Center, MOE Key Laboratory of Model Animal for Disease Study, Nanjing University, Nanjing 210061, China
| | - Douglas Vollrath
- Department of Genetics, Stanford University School of Medicine, CA 94305, USA
| | - Chi Pui Pang
- Department of Ophthalmology &Visual Sciences, The Chinese University of Hong Kong, Hong Kong
| | - Chen Zhao
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University and State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 210029, China.,State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat Sen University, Guangzhou, China
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Cathepsin proteases promote angiogenic sprouting and laser-induced choroidal neovascularisation in mice. Exp Eye Res 2013; 115:73-8. [DOI: 10.1016/j.exer.2013.06.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 05/28/2013] [Accepted: 06/10/2013] [Indexed: 01/26/2023]
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Petersen NHT, Olsen OD, Groth-Pedersen L, Ellegaard AM, Bilgin M, Redmer S, Ostenfeld MS, Ulanet D, Dovmark TH, Lønborg A, Vindeløv SD, Hanahan D, Arenz C, Ejsing CS, Kirkegaard T, Rohde M, Nylandsted J, Jäättelä M. Transformation-associated changes in sphingolipid metabolism sensitize cells to lysosomal cell death induced by inhibitors of acid sphingomyelinase. Cancer Cell 2013; 24:379-93. [PMID: 24029234 DOI: 10.1016/j.ccr.2013.08.003] [Citation(s) in RCA: 263] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Revised: 04/10/2013] [Accepted: 08/06/2013] [Indexed: 12/21/2022]
Abstract
Lysosomal membrane permeabilization and subsequent cell death may prove useful in cancer treatment, provided that cancer cell lysosomes can be specifically targeted. Here, we identify acid sphingomyelinase (ASM) inhibition as a selective means to destabilize cancer cell lysosomes. Lysosome-destabilizing experimental anticancer agent siramesine inhibits ASM by interfering with the binding of ASM to its essential lysosomal cofactor, bis(monoacylglycero)phosphate. Like siramesine, several clinically relevant ASM inhibitors trigger cancer-specific lysosomal cell death, reduce tumor growth in vivo, and revert multidrug resistance. Their cancer selectivity is associated with transformation-associated reduction in ASM expression and subsequent failure to maintain sphingomyelin hydrolysis during drug exposure. Taken together, these data identify ASM as an attractive target for cancer therapy.
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Affiliation(s)
- Nikolaj H T Petersen
- Department of Cell Death and Metabolism, Danish Cancer Society Research Center (DCRC), DK-2100 Copenhagen, Denmark
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14
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Negative regulation of the novel norpA(P24) suppressor, diehard4, in the endo-lysosomal trafficking underlies photoreceptor cell degeneration. PLoS Genet 2013; 9:e1003559. [PMID: 23754968 PMCID: PMC3674991 DOI: 10.1371/journal.pgen.1003559] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2012] [Accepted: 04/24/2013] [Indexed: 12/16/2022] Open
Abstract
Rhodopsin has been used as a prototype system to investigate G protein-coupled receptor (GPCR) internalization and endocytic sorting mechanisms. Failure of rhodopsin recycling upon light activation results in various degenerative retinal diseases. Accumulation of internalized rhodopsin in late endosomes and the impairment of its lysosomal degradation are associated with unregulated cell death that occurs in dystrophies. However, the molecular basis of rhodopsin accumulation remains elusive. We found that the novel norpAP24 suppressor, diehard4, is responsible for the inability of endo-lysosomal rhodopsin trafficking and retinal degeneration in Drosophila models of retinal dystrophies. We found that diehard4 encodes Osiris 21. Loss of its function suppresses retinal degeneration in norpAP24, rdgC306, and trp1, but not in rdgB2, suggesting a common cause of photoreceptor death. In addition, the loss of Osiris 21 function shifts the membrane balance between late endosomes and lysosomes as evidenced by smaller late endosomes and the proliferation of lysosomal compartments, thus facilitating the degradation of endocytosed rhodopsin. Our results demonstrate the existence of negative regulation in vesicular traffic between endosomes and lysosomes. We anticipate that the identification of additional components and an in-depth description of this specific molecular machinery will aid in therapeutic interventions of various retinal dystrophies and GPCR-related human diseases. Malfunctioning of phototransduction is the major cause of human blindness. Without functional phototransduction, rhodopsin-1, the major visual pigment, is rapidly endocytosed and accumulated in late endosomes. Impaired lysosomal delivery of endocytosed rhodopsin and its degradation has been reported to trigger progressive and light-dependent retinal degeneration in Drosophila models. It is intriguing why endocytosed rhodopsin accumulates in late endosomes instead of being delivered to lysosomes for degradation. Is this attributable to a saturation of rhodopsin endocytosis, which impedes the delivery capacity of the cell? To investigate the underlying mechanisms of rhodopsin accumulation in late endosomes, we used a suppressor of phototransduction mutants, which was identified previously from our unbiased genetic screen. This suppressor, called diehard4, shifts the membrane balance between late endosomes and lysosomes, resulting in the facilitated degradation of endocytosed rhodopsin. Our results clearly demonstrate that a previously unknown mechanism of negative regulation is actively engaged in vesicular traffic between endosomes and lysosomes in fly photoreceptors. We showed that eliminating such blockage alone was enough to rescue retinal degeneration in phototransduction mutants. From these results, we anticipate that the identification of additional components and an in-depth description of this molecular machinery will aid in therapeutic interventions of various retinal dystrophies and neurodegenerative disorders.
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Abstract
Lysosomes serve as the cellular recycling centre and are filled with numerous hydrolases that can degrade most cellular macromolecules. Lysosomal membrane permeabilization and the consequent leakage of the lysosomal content into the cytosol leads to so-called "lysosomal cell death". This form of cell death is mainly carried out by the lysosomal cathepsin proteases and can have necrotic, apoptotic or apoptosis-like features depending on the extent of the leakage and the cellular context. This article summarizes our current knowledge on lysosomal cell death with an emphasis on the upstream mechanisms that lead to lysosomal membrane permeabilization.
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Affiliation(s)
- Sonja Aits
- Danish Cancer Society Research Center, Cell Death and Metabolism, Strandboulevarden 49, DK-2100 Copenhagen, Denmark
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16
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Kumar S, Farmer R, Turnbull AP, Tripathy NK, Manjasetty BA. Structural and functional conservation profiles of novel cathepsin L-like proteins identified in the Drosophila melanogaster genome. J Biomol Struct Dyn 2012; 31:1481-9. [PMID: 23256878 DOI: 10.1080/07391102.2012.745379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Cathepsin L is a cysteine protease which degrades connective tissue proteins including collagen, elastin, and fibronectin. In this study, five well-characterized cathepsin L proteins from different arthropods were used as query sequences for the Drosophila genome database. The search yielded 10 cathepsin L-like sequences, of which eight putatively represent novel cathepsin L-like proteins. To understand the phylogenetic relationship among these cathepsin L-like proteins, a phylogenetic tree was constructed based on their sequences. In addition, models of the tertiary structures of cathepsin L were constructed using homology modeling methods and subjected to molecular dynamics simulations to obtain reasonable structure to understand its dynamical behavior. Our findings demonstrate that all of the potential Drosophila cathepsin L-like proteins contain at least one cathepsin propeptide inhibitor domain. Multiple sequence alignment and homology models clearly highlight the conservation of active site residues, disulfide bonds, and amino acid residues critical for inhibitor binding. Furthermore, comparative modeling indicates that the sequence/structure/function profiles and active site architectures are conserved.
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Affiliation(s)
- Sunil Kumar
- a An Autonomous Institute of Department of Biotechnology, Government of India , Institute of Life Sciences , Nalco Square, Bhubaneswar , 751023 , India
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