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Chiappa G, Fassio G, Modica MV, Oliverio M. Potential Ancestral Conoidean Toxins in the Venom Cocktail of the Carnivorous Snail Raphitoma purpurea (Montagu, 1803) (Neogastropoda: Raphitomidae). Toxins (Basel) 2024; 16:348. [PMID: 39195758 PMCID: PMC11359391 DOI: 10.3390/toxins16080348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2024] [Revised: 08/02/2024] [Accepted: 08/06/2024] [Indexed: 08/29/2024] Open
Abstract
Venomous marine gastropods of the superfamily Conoidea possess a rich arsenal of toxins, including neuroactive toxins. Venom adaptations might have played a fundamental role in the radiation of conoideans; nevertheless, there is still no knowledge about the venom of the most diversified family of the group: Raphitomidae Bellardi, 1875. In this study, transcriptomes were produced from the carcase, salivary glands, and proximal and distal venom ducts of the northeastern Atlantic species Raphitoma purpurea (Montagu, 1803). Using a gut barcoding approach, we were also able to report, for the first time, molecular evidence of a vermivorous diet for the genus. Transcriptomic analyses revealed over a hundred putative venom components (PVC), including 69 neurotoxins. Twenty novel toxin families, including some with high levels of expansion, were discovered. No significant difference was observed between the distal and proximal venom duct secretions. Peptides related to cone snail toxins (Cerm06, Pgam02, and turritoxin) and other venom-related proteins (disulfide isomerase and elevenin) were retrieved from the salivary glands. These salivary venom components may constitute ancestral adaptations for venom production in conoideans. Although often neglected, salivary gland secretions are of extreme importance for understanding the evolutionary history of conoidean venom.
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Affiliation(s)
- Giacomo Chiappa
- Department of Biology and Biotechnologies “Charles Darwin”, Sapienza University of Rome, Viale dell’Università 32, 00185 Rome, Italy; (G.F.); (M.O.)
| | - Giulia Fassio
- Department of Biology and Biotechnologies “Charles Darwin”, Sapienza University of Rome, Viale dell’Università 32, 00185 Rome, Italy; (G.F.); (M.O.)
| | - Maria Vittoria Modica
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Via Gregorio Allegri 1, 00198 Rome, Italy;
| | - Marco Oliverio
- Department of Biology and Biotechnologies “Charles Darwin”, Sapienza University of Rome, Viale dell’Università 32, 00185 Rome, Italy; (G.F.); (M.O.)
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Jiang S, Zhang W, Xiong Y, Zhang M, Yuan H, Niu Y, Qiao H, Fu H. NPC Intracellular Cholesterol Transporter 1 Regulates Ovarian Maturation and Molting in Female Macrobrachium nipponense. Int J Mol Sci 2024; 25:6049. [PMID: 38892237 PMCID: PMC11172811 DOI: 10.3390/ijms25116049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 05/23/2024] [Accepted: 05/25/2024] [Indexed: 06/21/2024] Open
Abstract
NPC intracellular cholesterol transporter 1 (NPC1) plays an important role in sterol metabolism and transport processes and has been studied in many vertebrates and some insects, but rarely in crustaceans. In this study, we characterized NPC1 from Macrobrachium nipponense (Mn-NPC1) and evaluated its functions. Its total cDNA length was 4283 bp, encoding for 1344 amino acids. It contained three conserved domains typical of the NPC family (NPC1_N, SSD, and PTC). In contrast to its role in insects, Mn-NPC1 was mainly expressed in the adult female hepatopancreas, with moderate expression in the ovary and heart. No expression was found in the embryo (stages CS-ZS) and only weak expression in the larval stages from hatching to the post-larval stage (L1-PL15). Mn-NPC1 expression was positively correlated with ovarian maturation. In situ hybridization showed that it was mainly located in the cytoplasmic membrane and nucleus of oocytes. A 25-day RNA interference experiment was employed to illustrate the Mn-NPC1 function in ovary maturation. Experimental knockdown of Mn-NPC1 using dsRNA resulted in a marked reduction in the gonadosomatic index and ecdysone content of M. nipponense females. The experimental group showed a significant delay in ovarian maturation and a reduction in the frequency of molting. These results expand our understanding of NPC1 in crustaceans and of the regulatory mechanism of ovarian maturation in M. nipponense.
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Affiliation(s)
- Sufei Jiang
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China; (S.J.); (W.Z.); (Y.X.)
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China; (M.Z.); (H.Y.); (Y.N.)
| | - Wenyi Zhang
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China; (S.J.); (W.Z.); (Y.X.)
| | - Yiwei Xiong
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China; (S.J.); (W.Z.); (Y.X.)
| | - Mengying Zhang
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China; (M.Z.); (H.Y.); (Y.N.)
| | - Huwei Yuan
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China; (M.Z.); (H.Y.); (Y.N.)
| | - Yunpeng Niu
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China; (M.Z.); (H.Y.); (Y.N.)
| | - Hui Qiao
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China; (S.J.); (W.Z.); (Y.X.)
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China; (M.Z.); (H.Y.); (Y.N.)
| | - Hongtuo Fu
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China; (S.J.); (W.Z.); (Y.X.)
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China; (M.Z.); (H.Y.); (Y.N.)
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Kendall RL, Holian A. Lysosomal BK channels facilitate silica-induced inflammation in macrophages. Inhal Toxicol 2024; 36:31-43. [PMID: 38261520 PMCID: PMC11080613 DOI: 10.1080/08958378.2024.2305112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 01/09/2024] [Indexed: 01/25/2024]
Abstract
BACKGROUND Lysosomal ion channels are proposed therapeutic targets for a number of diseases, including those driven by NLRP3 inflammasome-mediated inflammation. Here, the specific role of the lysosomal big conductance Ca2+-activated K+ (BK) channel was evaluated in a silica model of inflammation in murine macrophages. A specific-inhibitor of BK channel function, paxilline (PAX), and activators NS11021 and NS1619 were utilized to evaluate the role of lysosomal BK channel activity in silica-induced lysosomal membrane permeabilization (LMP) and NLRP3 inflammasome activation resulting in IL-1β release. METHODS Murine macrophages were exposed in vitro to crystalline silica following pretreatment with BK channel inhibitors or activators and LMP, cell death, and IL-1β release were assessed. In addition, the effect of PAX treatment on silica-induced cytosolic K+ decrease was measured. Finally, the effects of BK channel modifiers on lysosomal pH, proteolytic activity, and cholesterol transport were also evaluated. RESULTS PAX pretreatment significantly attenuated silica-induced cell death and IL-1β release. PAX caused an increase in lysosomal pH and decrease in lysosomal proteolytic activity. PAX also caused a significant accumulation of lysosomal cholesterol. BK channel activators NS11021 and NS1619 increased silica-induced cell death and IL-1β release. BK channel activation also caused a decrease in lysosomal pH and increase in lysosomal proteolytic function as well as a decrease in cholesterol accumulation. CONCLUSION Taken together, these results demonstrate that inhibiting lysosomal BK channel activity with PAX effectively reduced silica-induced cell death and IL-1β release. Blocking cytosolic K+ entry into the lysosome prevented LMP through the decrease of lysosomal acidification and proteolytic function and increase in lysosomal cholesterol.
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Affiliation(s)
- Rebekah L Kendall
- Center for Environmental Health Sciences, University of Montana, Missoula, MT, USA
| | - Andrij Holian
- Center for Environmental Health Sciences, University of Montana, Missoula, MT, USA
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Malla M, Sinha D, Chowdhury P, Bisesi BT, Chen Q. The cytoplasmic tail of the mechanosensitive channel Pkd2 regulates its internalization and clustering in eisosomes. J Cell Sci 2023; 136:jcs260598. [PMID: 37259828 PMCID: PMC10323245 DOI: 10.1242/jcs.260598] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 05/25/2023] [Indexed: 06/02/2023] Open
Abstract
Polycystins are a family of conserved ion channels, mutations of which lead to one of the most common human genetic disorders, namely, autosomal dominant polycystic kidney disease. Schizosacchromyces pombe possesses an essential polycystin homologue, Pkd2, which directs Ca2+ influx on the cell surface in response to membrane tension, but its structure remains unsolved. Here, we analyzed the structure-function relationship of Pkd2 based on its AlphaFold-predicted structure. Pkd2 consists of three domains, the extracellular lipid-binding domain (LBD), nine-helix transmembrane domain (TMD) and C-terminal cytoplasmic domain (CCD). Our genetic and microscopy data revealed that LBD and TMD are essential for targeting Pkd2 to the plasma membrane from the endoplasmic reticulum. In comparison, CCD ensures the polarized distribution of Pkd2 by promoting its internalization and preventing its clustering in the eisosome, a caveolae-like membrane compartment. The domains of Pkd2 and their functions are conserved in other fission yeast species. We conclude that both extracellular and cytoplasmic domains of Pkd2 are crucial for its intracellular trafficking and function. We propose that mechanosensitive channels can be desensitized through either internalization or clustering in low-tension membrane compartments.
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Affiliation(s)
- Mamata Malla
- Department of Biological Sciences, The University of Toledo, 2801 West Bancroft Street, Toledo, OH 43606, USA
| | - Debatrayee Sinha
- Department of Biological Sciences, The University of Toledo, 2801 West Bancroft Street, Toledo, OH 43606, USA
| | - Pritha Chowdhury
- Department of Biological Sciences, The University of Toledo, 2801 West Bancroft Street, Toledo, OH 43606, USA
| | - Benjamin Thomas Bisesi
- Department of Biological Sciences, The University of Toledo, 2801 West Bancroft Street, Toledo, OH 43606, USA
| | - Qian Chen
- Department of Biological Sciences, The University of Toledo, 2801 West Bancroft Street, Toledo, OH 43606, USA
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Kendall RL, Holian A. Cholesterol-dependent molecular mechanisms contribute to cationic amphiphilic drugs' prevention of silica-induced inflammation. Eur J Cell Biol 2023; 102:151310. [PMID: 36934670 PMCID: PMC10330738 DOI: 10.1016/j.ejcb.2023.151310] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 03/11/2023] [Accepted: 03/13/2023] [Indexed: 03/18/2023] Open
Abstract
Silicosis is considered an irreversible chronic inflammatory disease caused by the inhalation of crystalline silica (cSiO2). The cycle of inflammation that drives silicosis and other particle-caused respiratory diseases is mediated by NLRP3 inflammasome activity in macrophages resulting in the release of IL-1β. Lysosomal membrane permeability (LMP) initiated by inhaled particles is the key regulatory step in leading to NLRP3 activity. In addition to its role in LMP, the lysosome is crucial to cellular cholesterol trafficking. Lysosomal cholesterol has been demonstrated to regulate LMP while cationic amphiphilic drugs (CADs) reduce cholesterol trafficking from lysosomes and promote endolysosomal cholesterol accumulation as seen in Niemann Pick disease. Using a bone marrow derived macrophage (BMdM) model, four CADs were examined for their potential to reduce cSiO2-induced inflammation. Here we found that FDA-approved CAD drugs imipramine, hydroxychloroquine, fluvoxamine, and fluoxetine contributed to reduced LMP and IL-1β release in cSiO2 treated BMdM. These drugs inhibited lysosomal enzymatic activity of acid sphingomyelinase, decreased lysosomal proteolytic function, and increased lysosomal pH. CADs also demonstrated a significant increase in lysosomal-associated free cholesterol. Increased lysosomal cholesterol was associated with a significant reduction in cSiO2 induced LMP and IL-1β release. In contrast, reduced lysosomal cholesterol significantly exacerbated cSiO2-induced IL-1β release and reduced the protective effect of CADs on IL-1β release following cSiO2 exposure. Taken together, these results suggest that CAD modification of lysosomal cholesterol may be used to reduce LMP and cSiO2-induced inflammation and could prove an effective therapeutic for silicosis and other particle-caused respiratory diseases.
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Affiliation(s)
- Rebekah L Kendall
- Center for Environmental Health Science, University of Montana, 32 Campus Way, Missoula, MT 59812, USA.
| | - Andrij Holian
- Center for Environmental Health Science, University of Montana, 32 Campus Way, Missoula, MT 59812, USA
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Liang D, Chen H, An L, Li Y, Zhao P, Upadhyay A, Hansson BS, Zhao J, Han Q. Molecular identification and functional analysis of Niemann-Pick type C2 proteins,carriers for semiochemicals and other hydrophobic compounds in the brown dog tick, Rhipicephalus linnaei. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2023; 193:105451. [PMID: 37247999 DOI: 10.1016/j.pestbp.2023.105451] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Revised: 05/01/2023] [Accepted: 05/02/2023] [Indexed: 05/31/2023]
Abstract
Ticks are important vectors of many pathogens with tremendous impact on human and animal health. Studies of semiochemical interactions and mechanisms underlying chemoreception can provide important tools in tick management. Niemann-Pick type C2 (NPC2) proteins have been proposed as one type of chemoreceptor in arthropods. Here, we cloned two NPC2 genes in the brown dog tick, Rhipicephalus linnaei, the tropical lineage previously named R. sanguineus sensu lato and characterized them functionally. R.linNPC2a and R.linNPC2b genes were found to be expressed at each developmental stage with the highest level in adult males. By using quantitative real-time PCR we revealed expression in multiple tissues, including midgut, ovary, salivary glands and legs. Ligand binding analysis revealed that R.linNPC2b bound a wide spectrum of compounds, with β-ionone, α-amylcinnamaldehyde, 2-nitrophenol and benzaldehyde displaying the strongest binding affinity (Ki < 10 μM), whereas R.linNPC2a showed a more narrow ligand binding range, with intermediate binding affinity to α-amylcinnamaldehyde and 2-nitrophenol (Ki < 20 μM). Molecular docking indicated that the amino acid residue Phe89, Leu77 and Val131 of R.linNPC2a and Phe70, Leu132 and Phe73 of R.linNPC2b could bind multiple ligands. These residues might thus play a key role in the identification of the volatiles. Our results contribute to the understanding of olfactory mechanisms of R. linnaei and can offer new pathways towards new management strategies.
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Affiliation(s)
- Dejuan Liang
- Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, Hainan 570228, China; One Health Institute, Hainan University, Haikou, Hainan 570228, China
| | - Huaqing Chen
- Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, Hainan 570228, China; One Health Institute, Hainan University, Haikou, Hainan 570228, China
| | - Liping An
- Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, Hainan 570228, China; One Health Institute, Hainan University, Haikou, Hainan 570228, China
| | - Yao Li
- Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, Hainan 570228, China; One Health Institute, Hainan University, Haikou, Hainan 570228, China
| | - Peizhen Zhao
- Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, Hainan 570228, China; One Health Institute, Hainan University, Haikou, Hainan 570228, China
| | - Archana Upadhyay
- Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, Hainan 570228, China; One Health Institute, Hainan University, Haikou, Hainan 570228, China
| | - Bill S Hansson
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Jianguo Zhao
- Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, Hainan 570228, China; One Health Institute, Hainan University, Haikou, Hainan 570228, China.
| | - Qian Han
- Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, Hainan 570228, China; One Health Institute, Hainan University, Haikou, Hainan 570228, China.
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Liu X, Zhang A, Chen Z, Feng Y, Wang D, Zhu B. An ecdysteroid-regulated 16-kDa protein homolog participates in the immune response of the crayfish Procambarus clarkii. FISH & SHELLFISH IMMUNOLOGY 2023; 137:108750. [PMID: 37084855 DOI: 10.1016/j.fsi.2023.108750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 04/12/2023] [Accepted: 04/17/2023] [Indexed: 05/03/2023]
Abstract
An ecdysteroid-regulated 16-kDa protein homolog (named Pc-E16), encoding 150 amino acid residues with a conserved MD-2-related lipid-recognition domain, was first identified in Procambarus clarkii. Phylogenetic analyses indicated similarity between Pc-E16 and 16-kDa proteins from Aplysia californica and insects. Recombinant Pc-E16 protein was successfully expressed in BL21 (DE3) Escherichia coli cells, and polyclonal antibodies against purified Pc-E16 proteins were prepared. In comparison with other tissues, Pc-E16 was highly expressed in the intestine; real-time PCR and Western blotting results indicated that Pc-E16 expression was significantly induced by lipopolysaccharides in hepatopancreas and hemocytes. Pc-E16-mediated signaling pathways were investigated by digital gene expression analysis following RNA interference targeting Pc-E16. A total of 6103 differentially expressed genes (DEGs) were identified, of which 3318 were up- and 2785 were downregulated. Many DEGs were involved in binding and catalytic activity. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis revealed that DEGs were clustered into 225 pathways, and 15 significantly enriched pathways were identified at the immune system level. In addition, the expression level of Pc-E16 in hemocytes and hepatopancreas was obviously downregulated at 48 h after dsRNA injection, and Pc-E16-RNAi treatment affected the expression levels of immune-related genes. Altogether, our results suggest that Pc-E16 is involved in the innate immune response of P. clarkii.
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Affiliation(s)
- Xiaoxiao Liu
- College of Life Sciences, Anhui Agricultural University, Hefei, 230036, China
| | - Awei Zhang
- College of Life Sciences, Anhui Agricultural University, Hefei, 230036, China
| | - Zhe Chen
- College of Life Sciences, Anhui Agricultural University, Hefei, 230036, China
| | - Yuanyuan Feng
- College of Life Sciences, Anhui Agricultural University, Hefei, 230036, China
| | - Daojun Wang
- College of Life Sciences, Anhui Agricultural University, Hefei, 230036, China
| | - Baojian Zhu
- College of Life Sciences, Anhui Agricultural University, Hefei, 230036, China.
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Pfrieger FW. The Niemann-Pick type diseases – A synopsis of inborn errors in sphingolipid and cholesterol metabolism. Prog Lipid Res 2023; 90:101225. [PMID: 37003582 DOI: 10.1016/j.plipres.2023.101225] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 03/27/2023] [Accepted: 03/27/2023] [Indexed: 04/03/2023]
Abstract
Disturbances of lipid homeostasis in cells provoke human diseases. The elucidation of the underlying mechanisms and the development of efficient therapies represent formidable challenges for biomedical research. Exemplary cases are two rare, autosomal recessive, and ultimately fatal lysosomal diseases historically named "Niemann-Pick" honoring the physicians, whose pioneering observations led to their discovery. Acid sphingomyelinase deficiency (ASMD) and Niemann-Pick type C disease (NPCD) are caused by specific variants of the sphingomyelin phosphodiesterase 1 (SMPD1) and NPC intracellular cholesterol transporter 1 (NPC1) or NPC intracellular cholesterol transporter 2 (NPC2) genes that perturb homeostasis of two key membrane components, sphingomyelin and cholesterol, respectively. Patients with severe forms of these diseases present visceral and neurologic symptoms and succumb to premature death. This synopsis traces the tortuous discovery of the Niemann-Pick diseases, highlights important advances with respect to genetic culprits and cellular mechanisms, and exposes efforts to improve diagnosis and to explore new therapeutic approaches.
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The Cerebellum in Niemann-Pick C1 Disease: Mouse Versus Man. CEREBELLUM (LONDON, ENGLAND) 2023; 22:102-119. [PMID: 35040097 DOI: 10.1007/s12311-021-01347-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/17/2021] [Indexed: 02/01/2023]
Abstract
Selective neuronal vulnerability is common to most degenerative disorders, including Niemann-Pick C (NPC), a rare genetic disease with altered intracellular trafficking of cholesterol. Purkinje cell dysfunction and loss are responsible for cerebellar ataxia, which is among the prevailing neurological signs of the NPC disease. In this review, we focus on some questions that are still unresolved. First, we frame the cerebellar vulnerability in the context of the extended postnatal time length by which the development of this structure is completed in mammals. In line with this thought, the much later development of cerebellar symptoms in humans is due to the later development and/or maturation of the cerebellum. Hence, the occurrence of developmental events under a protracted condition of defective intracellular cholesterol mobilization hits the functional maturation of the various cell types generating the ground of increased vulnerability. This is particularly consistent with the high cholesterol demand required for cell proliferation, migration, differentiation, and synapse formation/remodeling. Other major questions we address are why the progression of Purkinje cells loss is always from the anterior to the posterior lobes and why cerebellar defects persist in the mouse model even when genetic manipulations can lead to nearly normal survival.
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Cologna SM, Pathmasiri KC, Pergande MR, Rosenhouse-Dantsker A. Alterations in Cholesterol and Phosphoinositides Levels in the Intracellular Cholesterol Trafficking Disorder NPC. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1422:143-165. [PMID: 36988880 DOI: 10.1007/978-3-031-21547-6_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
Abstract
Lipid mistrafficking is a biochemical hallmark of Niemann-Pick Type C (NPC) disease and is classically characterized with endo/lysosomal accumulation of unesterified cholesterol due to genetic mutations in the cholesterol transporter proteins NPC1 and NPC2. Storage of this essential signaling lipid leads to a sequence of downstream events, including oxidative stress, calcium imbalance, neuroinflammation, and progressive neurodegeneration, another hallmark of NPC disease. These observations have been validated in a growing number of studies ranging from NPC cell cultures and animal models to patient specimens. In recent reports, alterations in the levels of another class of critical signaling lipids, namely phosphoinositides, have been described in NPC disease. Focusing on cholesterol and phosphoinositides, the chapter begins by reviewing the interactions of NPC proteins with cholesterol and their role in cholesterol transport. It then continues to describe the modulation of cholesterol efflux in NPC disease. The chapter concludes with a summary of findings related to the functional consequences of perturbations in phosphoinositides in this fatal disease.
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Affiliation(s)
| | | | - Melissa R Pergande
- Department of Chemistry, University of Illinois Chicago, Chicago, IL, USA
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11
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A Deeper Insight into the Tick Salivary Protein Families under the Light of Alphafold2 and Dali: Introducing the TickSialoFam 2.0 Database. Int J Mol Sci 2022; 23:ijms232415613. [PMID: 36555254 PMCID: PMC9779611 DOI: 10.3390/ijms232415613] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/05/2022] [Accepted: 12/06/2022] [Indexed: 12/14/2022] Open
Abstract
Hard ticks feed for several days or weeks on their hosts and their saliva contains thousands of polypeptides belonging to dozens of families, as identified by salivary transcriptomes. Comparison of the coding sequences to protein databases helps to identify putative secreted proteins and their potential functions, directing and focusing future studies, usually done with recombinant proteins that are tested in different bioassays. However, many families of putative secreted peptides have a unique character, not providing significant matches to known sequences. The availability of the Alphafold2 program, which provides in silico predictions of the 3D polypeptide structure, coupled with the Dali program which uses the atomic coordinates of a structural model to search the Protein Data Bank (PDB) allows another layer of investigation to annotate and ascribe a functional role to proteins having so far being characterized as "unique". In this study, we analyzed the classification of tick salivary proteins under the light of the Alphafold2/Dali programs, detecting novel protein families and gaining new insights relating the structure and function of tick salivary proteins.
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12
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Rogers MA, Chang CCY, Maue RA, Melton EM, Peden AA, Garver WS, Lee J, Schroen P, Huang M, Chang TY. Acat1/Soat1 knockout extends the mutant Npc1 mouse lifespan and ameliorates functional deficiencies in multiple organelles of mutant cells. Proc Natl Acad Sci U S A 2022; 119:e2201646119. [PMID: 35507892 PMCID: PMC9170141 DOI: 10.1073/pnas.2201646119] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 03/16/2022] [Indexed: 11/18/2022] Open
Abstract
Multiple membrane organelles require cholesterol for proper function within cells. The Niemann-Pick type C (NPC) proteins export cholesterol from endosomes to other membrane compartments, including the endoplasmic reticulum (ER), plasma membrane (PM), trans-Golgi network (TGN), and mitochondria, to meet their cholesterol requirements. Defects in NPC cause malfunctions in multiple membrane organelles and lead to an incurable neurological disorder. Acyl-coenzyme A:cholesterol acyltransferase 1 (ACAT1), a resident enzyme in the ER, converts cholesterol to cholesteryl esters for storage. In mutant NPC cells, cholesterol storage still occurs in an NPC-independent manner. Here we report the interesting finding that in a mutant Npc1 mouse (Npc1nmf), Acat1 gene (Soat1) knockout delayed the onset of weight loss, motor impairment, and Purkinje neuron death. It also improved hepatosplenic pathology and prolonged lifespan by 34%. In mutant NPC1 fibroblasts, ACAT1 blockade (A1B) increased cholesterol content associated with TGN-rich membranes and mitochondria, while decreased cholesterol content associated with late endosomes. A1B also restored proper localization of syntaxin 6 and golgin 97 (key proteins in membrane trafficking at TGN) and improved the levels of cathepsin D (a key protease in lysosome and requires Golgi/endosome transport for maturation) and ABCA1 (a key protein controlling cholesterol release at PM). This work supports the hypothesis that diverting cholesterol from storage can benefit multiple diseases that involve cholesterol deficiencies in cell membranes.
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Affiliation(s)
- Maximillian A. Rogers
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
| | - Catherine C. Y. Chang
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
| | - Robert A. Maue
- Department of Biology, Dartmouth College, Hanover, NH 03755
| | - Elaina M. Melton
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
| | - Andrew A. Peden
- Department of Biomedical Science, Centre for Membrane Interactions and Dynamics, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - William S. Garver
- Department of Chemistry & Chemical Biology, University of New Mexico, Albuquerque, NM 87131
| | - Junghoon Lee
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
| | - Peter Schroen
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
| | - Mitchell Huang
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
| | - Ta-Yuan Chang
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
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13
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Irie T. Inclusion Solves Insolubility —Translational Research Cycle from Bedside to Bench and Bench to Bedside for Drug Development Targeting Niemann-Pick Disease Type C—. YAKUGAKU ZASSHI 2022; 142:389-400. [DOI: 10.1248/yakushi.21-00215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Tetsumi Irie
- Graduate School of Life Sciences, Kumamoto University
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14
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Sabanés Zariquiey F, Jacoby E, Vos A, van Vlijmen HWT, Tresadern G, Harvey J. Divide and Conquer. Pocket-Opening Mixed-Solvent Simulations in the Perspective of Docking Virtual Screening Applications for Drug Discovery. J Chem Inf Model 2022; 62:533-543. [PMID: 35041430 DOI: 10.1021/acs.jcim.1c01164] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The existence of a druggable binding pocket is a prerequisite for computational drug-target interaction studies including virtual screening. Retrospective studies have shown that extended sampling methods like Markov State Modeling and mixed-solvent simulations can identify cryptic pockets relevant for drug discovery. Here, we apply a combination of mixed-solvent molecular dynamics (MD) and time-structure independent component analysis (TICA) to four retrospective case studies: NPC2, the CECR2 bromodomain, TEM-1, and MCL-1. We compare previous experimental and computational findings to our results. It is shown that the successful identification of cryptic pockets depends on the system and the cosolvent probes. We used alternative TICA internal features such as the unbiased backbone coordinates or backbone dihedrals versus biased interatomic distances. We found that in the case of NPC2, TEM-1, and MCL-1, the use of unbiased features is able to identify cryptic pockets, although in the case of the CECR2 bromodomain, more specific features are required to properly capture a pocket opening. In the perspective of virtual screening applications, it is shown how docking studies with the parent ligands depend critically on the conformational state of the targets.
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Affiliation(s)
| | - Edgar Jacoby
- Computational Chemistry, Janssen Research & Development, Turnhoutseweg 30, B-2340 Beerse, Belgium
| | - Ann Vos
- Computational Chemistry, Janssen Research & Development, Turnhoutseweg 30, B-2340 Beerse, Belgium
| | - Herman W T van Vlijmen
- Computational Chemistry, Janssen Research & Development, Turnhoutseweg 30, B-2340 Beerse, Belgium
| | - Gary Tresadern
- Computational Chemistry, Janssen Research & Development, Turnhoutseweg 30, B-2340 Beerse, Belgium
| | - Jeremy Harvey
- Department of Chemistry, KU Leuven, Celestijnenlaan 200F, 3001 Leuven, Belgium
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15
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Computational analysis of altered one- and two-photon CD of sterols inside a protein binding pocket. Theor Chem Acc 2022. [DOI: 10.1007/s00214-022-02866-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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16
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Winkler MBL, Nel L, Frain KM, Dedic E, Olesen E, Pedersen BP. Sterol uptake by the NPC system in eukaryotes: a Saccharomyces cerevisiae perspective. FEBS Lett 2022; 596:160-179. [PMID: 34897668 DOI: 10.1002/1873-3468.14253] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 12/03/2021] [Accepted: 12/03/2021] [Indexed: 12/11/2022]
Abstract
Sterols are an essential component of membranes in all eukaryotic cells and the precursor of multiple indispensable cellular metabolites. After endocytotic uptake, sterols are integrated into the lysosomal membrane by the Niemann-Pick type C (NPC) system before redistribution to other membranes. The process is driven by two proteins that, together, compose the NPC system: the lysosomal sterol shuttle protein NPC2 and the membrane protein NPC1 (named NCR1 in fungi), which integrates sterols into the lysosomal membrane. The Saccharomyces cerevisiae NPC system provides a compelling model to study the molecular mechanism of sterol integration into membranes and sterol homeostasis. This review summarizes recent advances in the field, and by interpreting available structural data, we propose a unifying conceptual model for sterol loading, transfer and transport by NPC proteins.
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Affiliation(s)
- Mikael B L Winkler
- Department of Molecular Biology and Genetics, Aarhus University, Denmark
| | - Lynette Nel
- Department of Molecular Biology and Genetics, Aarhus University, Denmark
| | - Kelly M Frain
- Department of Molecular Biology and Genetics, Aarhus University, Denmark
| | - Emil Dedic
- Department of Molecular Biology and Genetics, Aarhus University, Denmark
| | - Esben Olesen
- Department of Molecular Biology and Genetics, Aarhus University, Denmark
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17
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Jiang X, Ory DS. Advancing Diagnosis and Treatment of Niemann-Pick C disease through Biomarker Discovery. EXPLORATION OF NEUROPROTECTIVE THERAPY 2021; 1:146-158. [PMID: 35356760 PMCID: PMC8963791 DOI: 10.37349/ent.2021.00012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Accepted: 11/05/2021] [Indexed: 05/30/2023]
Abstract
Niemann-Pick C is a rare neurodegenerative, lysosomal storage disease caused by accumulation of unesterified cholesterol. Diagnosis of the disease is often delayed due to its rarity, the heterogeneous presentation and the early non-specific symptoms. The discovery of disease-specific biomarkers - cholestane-3β,5α,6β-triol (C-triol), trihydroxycholanic acid glycinate (TCG) and N-palmitoyl-O-phosphocholineserine (PPCS, initially referred to as lysoSM-509) - has led to development of non-invasive, blood-based diagnostics. Dissemination of these rapid, sensitive, and specific clinical assays has accelerated diagnosis. Moreover, the superior receiver operating characteristic of the TCG bile acid biomarker and its detection in dried blood spots has also facilitated development of a newborn screen for NPC, which is currently being piloted in New York state. The C-triol, TCG and PPCS biomarkers have also proven useful for monitoring treatment response in peripheral tissues, but are uninformative with respect to treatment efficacy in the central nervous system (CNS). A major gap for the field is the lack of a validated, non-invasive biomarker to monitor the course of disease and CNS response to therapy.
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Affiliation(s)
- Xuntian Jiang
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
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18
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Zhao J, Zhang W, Wu T, Wang H, Mao J, Liu J, Zhou Z, Lin X, Yan H, Wang Q. Efferocytosis in the Central Nervous System. Front Cell Dev Biol 2021; 9:773344. [PMID: 34926460 PMCID: PMC8678611 DOI: 10.3389/fcell.2021.773344] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 10/25/2021] [Indexed: 11/23/2022] Open
Abstract
The effective clearance of apoptotic cells is essential for maintaining central nervous system (CNS) homeostasis and restoring homeostasis after injury. In most cases of physiological apoptotic cell death, efferocytosis prevents inflammation and other pathological conditions. When apoptotic cells are not effectively cleared, destruction of the integrity of the apoptotic cell membrane integrity, leakage of intracellular contents, and secondary necrosis may occur. Efferocytosis is the mechanism by which efferocytes quickly remove apoptotic cells from tissues before they undergo secondary necrosis. Cells with efferocytosis functions, mainly microglia, help to eliminate apoptotic cells from the CNS. Here, we discuss the impacts of efferocytosis on homeostasis, the mechanism of efferocytosis, the associations of efferocytosis failure and CNS diseases, and the current clinical applications of efferocytosis. We also identify efferocytosis as a novel potential target for exploring the causes and treatments of CNS diseases.
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Affiliation(s)
- Jiayi Zhao
- Department of Anesthesia, Zhejiang Hospital, Hangzhou, China
| | - Weiqi Zhang
- The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, China
| | - Tingting Wu
- The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, China
| | - Hongyi Wang
- The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, China
| | - Jialiang Mao
- The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, China
| | - Jian Liu
- The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, China
| | - Ziheng Zhou
- The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, China
| | - Xianfeng Lin
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Huige Yan
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Qingqing Wang
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
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19
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Reinholdt P, Joensen LE, Petersen D, Szomek M, Mularski A, Simonsen AC, Kongsted J, Wüstner D. Photophysical and Structural Characterization of Intrinsically Fluorescent Sterol Aggregates. J Phys Chem B 2021; 125:5838-5852. [PMID: 34061522 DOI: 10.1021/acs.jpcb.1c00628] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Self-association of cholesterol into aggregates and crystals is a hallmark of developing atherosclerosis. Intrinsically fluorescent sterols, such as dehydroergosterol (DHE), can be used to study sterol aggregation by fluorescence spectroscopy and microscopy, but a thorough understanding of DHE's photophysical and structural properties in the aggregated state is missing. Here, we show that DHE forms submicron fluorescent aggregates when evaporated from an ethanol solution. Using atomic force microscopy, we find that DHE, like cholesterol, forms compact oblate-shape aggregates of <100 nm in diameter. DHE's fluorescence is lowered in the aggregate compared to the monomeric form, and characteristic spectral changes accompany the aggregation process. Electronic structure calculations of DHE dimers in water indicate that Frenkel-type exciton coupling contributes to the lowered DHE fluorescence in the aggregates. Using molecular dynamics (MD) simulations, we show that DHE forms compact aggregates on the nanosecond scale and with strong intermolecular attraction, in which a broad range of orientations, and therefore electronic couplings, will take place. Tight packing of DHE in aggregates also lowers the apparent absorption cross section, further reducing the molecular brightness of the aggregates. Our results pave the way for systematic solubility studies of intrinsically fluorescent analogues of biologically relevant sterols.
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Affiliation(s)
- Peter Reinholdt
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Lütje E Joensen
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Daniel Petersen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Maria Szomek
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Anna Mularski
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Adam Cohen Simonsen
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Jacob Kongsted
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Daniel Wüstner
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
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20
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Lakpa KL, Khan N, Afghah Z, Chen X, Geiger JD. Lysosomal Stress Response (LSR): Physiological Importance and Pathological Relevance. J Neuroimmune Pharmacol 2021; 16:219-237. [PMID: 33751445 PMCID: PMC8099033 DOI: 10.1007/s11481-021-09990-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 03/08/2021] [Indexed: 02/08/2023]
Abstract
Extensive work has characterized endoplasmic reticulum (ER) and mitochondrial stress responses. In contrast, very little has been published about stress responses in lysosomes; subcellular acidic organelles that are physiologically important and are of pathological relevance. The greater lysosomal system is dynamic and is comprised of endosomes, lysosomes, multivesicular bodies, autophagosomes, and autophagolysosomes. They are important regulators of cellular physiology, they represent about 5% of the total cellular volume, they are heterogeneous in their sizes and distribution patterns, they are electron dense, and their subcellular positioning within cells varies in response to stimuli, insults and pH. These organelles are also integral to the pathogenesis of lysosomal storage diseases and it is increasingly recognized that lysosomes play important roles in the pathogenesis of such diverse conditions as neurodegenerative disorders and cancer. The purpose of this review is to focus attention on lysosomal stress responses (LSR), compare LSR with better characterized stress responses in ER and mitochondria, and form a framework for future characterizations of LSR. We synthesized data into the concept of LSR and present it here such that the definition of LSR can be modified as new knowledge is added and specific therapeutics are developed.
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Affiliation(s)
- Koffi L Lakpa
- Department of Biomedical Sciences, Dakota School of Medicine and Health Sciences, University of North, Grand Forks, ND, 58203, USA
| | - Nabab Khan
- Department of Biomedical Sciences, Dakota School of Medicine and Health Sciences, University of North, Grand Forks, ND, 58203, USA
| | - Zahra Afghah
- Department of Biomedical Sciences, Dakota School of Medicine and Health Sciences, University of North, Grand Forks, ND, 58203, USA
| | - Xuesong Chen
- Department of Biomedical Sciences, Dakota School of Medicine and Health Sciences, University of North, Grand Forks, ND, 58203, USA
| | - Jonathan D Geiger
- Department of Biomedical Sciences, Dakota School of Medicine and Health Sciences, University of North, Grand Forks, ND, 58203, USA.
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21
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Cruz DL, Pipalia N, Mao S, Gadi D, Liu G, Grigalunas M, O'Neill M, Quinn TR, Kipper A, Ekebergh A, Dimmling A, Gartner C, Melancon BJ, Wagner FF, Holson E, Helquist P, Wiest O, Maxfield FR. Inhibition of Histone Deacetylases 1, 2, and 3 Enhances Clearance of Cholesterol Accumulation in Niemann-Pick C1 Fibroblasts. ACS Pharmacol Transl Sci 2021; 4:1136-1148. [PMID: 34151204 PMCID: PMC8204796 DOI: 10.1021/acsptsci.1c00033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Indexed: 11/29/2022]
Abstract
![]()
Niemann-Pick disease type C1 (NPC1) is a rare genetic cholesterol storage disorder
caused by mutations in the NPC1 gene. Mutations in this transmembrane
late endosome protein lead to loss of normal cholesterol efflux from late endosomes and
lysosomes. It has been shown that broad spectrum histone deacetylase inhibitors
(HDACi's) such as Vorinostat correct the cholesterol accumulation phenotype in the
majority of NPC1 mutants tested in cultured cells. In order to determine the optimal
specificity for HDACi correction of the mutant NPC1s, we screened 76 HDACi's of varying
specificity. We tested the ability of these HDACi's to correct the excess accumulation
of cholesterol in patient fibroblast cells that homozygously express
NPC1I1061T, the most common mutation. We
determined that inhibition of HDACs 1, 2, and 3 is important for correcting the defect,
and combined inhibition of all three is needed to achieve the greatest effect,
suggesting a need for multiple effects of the HDACi treatments. Identifying the specific
HDACs involved in the process of regulating cholesterol trafficking in NPC1 will help to
focus the search for more specific druggable targets.
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Affiliation(s)
- Dana L Cruz
- Department of Biochemistry, Weill Cornell Medical College, New York, New York 10065, United States
| | - Nina Pipalia
- Department of Biochemistry, Weill Cornell Medical College, New York, New York 10065, United States
| | - Shu Mao
- Department of Biochemistry, Weill Cornell Medical College, New York, New York 10065, United States
| | - Deepti Gadi
- Department of Biochemistry, Weill Cornell Medical College, New York, New York 10065, United States
| | - Gang Liu
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Michael Grigalunas
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Matthew O'Neill
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Taylor R Quinn
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Andi Kipper
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Andreas Ekebergh
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Alexander Dimmling
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Carlos Gartner
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Bruce J Melancon
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Florence F Wagner
- Eli and Edythe L. Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States
| | - Edward Holson
- Eli and Edythe L. Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States.,KDAc Therapeutics, Cambridge, Massachusetts 02142, United States
| | - Paul Helquist
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Olaf Wiest
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States.,Laboratory of Computational Chemistry and Drug Design, State Key Laboratory of Chemical Oncogenomics, Peking University, Shenzhen Graduate School, Shenzhen 518055, P.R. China
| | - Frederick R Maxfield
- Department of Biochemistry, Weill Cornell Medical College, New York, New York 10065, United States
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22
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Bai Y, Yin S, Gbordzor V, Guo Y, Bai Q, Wang S, Wei X, Chen N, Zhang Y, Li W. Increase in plasma Niemann-Pick disease type C2 protein is associated with poor prognosis of sepsis. Sci Rep 2021; 11:5907. [PMID: 33723331 PMCID: PMC7961030 DOI: 10.1038/s41598-021-85478-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 03/02/2021] [Indexed: 11/09/2022] Open
Abstract
The functional significance of extracellular Niemann-Pick disease type C2 protein (NPC2) is poorly defined. It is not known whether there is an association between plasma NPC2 and sepsis. Our exploratory, quantitative proteomic analysis showed a significant increase in the level of plasma NPC2 in moribund sepsis patients. Thus, we subsequently determined NPC2 concentration in plasma from healthy subjects, pneumonia patients and sepsis patients with comorbid pneumonia; and analyzed the association of plasma NPC2 with organ dysfunction and prognosis of sepsis patients. Our data shows that plasma NPC2 concentration was significantly higher in pneumonia and sepsis patients than healthy subjects, and was further increased in sepsis patients when the SOFA score reached 14. In addition, NPC2 concentration was significantly higher in patients that subsequently developed septic shock or died within 30 days. Moreover, NPC2 level showed the strongest association with the degree of renal dysfunction in sepsis patients. In moribund sepsis patients, however, NPC2 had highest correlation coefficient with indicators of coagulation anomaly. Based on these results, we conclude that the increase in plasma NPC2 in sepsis patients is associated with multiple organ failure, possibly results from a deficiency in renal clearance, and may serve as a prognostic marker for sepsis.
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Affiliation(s)
- Yu Bai
- Sepsis Laboratory, Center for Translational Medicine, Huaihe Hospital, Henan University, 115 Xi Men Blvd, Kaifeng, Henan, China
| | - Shuangyi Yin
- Sepsis Laboratory, Center for Translational Medicine, Huaihe Hospital, Henan University, 115 Xi Men Blvd, Kaifeng, Henan, China
| | - Vivian Gbordzor
- Sepsis Laboratory, Center for Translational Medicine, Huaihe Hospital, Henan University, 115 Xi Men Blvd, Kaifeng, Henan, China
| | - Yu Guo
- Sepsis Laboratory, Center for Translational Medicine, Huaihe Hospital, Henan University, 115 Xi Men Blvd, Kaifeng, Henan, China.,Department of Pulmonary and Critical Care Medicine, Huaihe Hospital, Henan University, 115 Xi Men Blvd, Kaifeng, Henan, China
| | - Qing Bai
- Sepsis Laboratory, Center for Translational Medicine, Huaihe Hospital, Henan University, 115 Xi Men Blvd, Kaifeng, Henan, China.,Department of Pulmonary and Critical Care Medicine, Huaihe Hospital, Henan University, 115 Xi Men Blvd, Kaifeng, Henan, China
| | - Shuaiwei Wang
- Sepsis Laboratory, Center for Translational Medicine, Huaihe Hospital, Henan University, 115 Xi Men Blvd, Kaifeng, Henan, China
| | - Xiangyan Wei
- Sepsis Laboratory, Center for Translational Medicine, Huaihe Hospital, Henan University, 115 Xi Men Blvd, Kaifeng, Henan, China
| | - Na Chen
- Department of Pulmonary and Critical Care Medicine, Huaihe Hospital, Henan University, 115 Xi Men Blvd, Kaifeng, Henan, China
| | - Yijie Zhang
- Sepsis Laboratory, Center for Translational Medicine, Huaihe Hospital, Henan University, 115 Xi Men Blvd, Kaifeng, Henan, China.
| | - Wei Li
- Sepsis Laboratory, Center for Translational Medicine, Huaihe Hospital, Henan University, 115 Xi Men Blvd, Kaifeng, Henan, China.
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23
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Bansia H, Mahanta P, Yennawar NH, Ramakumar S. Small Glycols Discover Cryptic Pockets on Proteins for Fragment-Based Approaches. J Chem Inf Model 2021; 61:1322-1333. [PMID: 33570386 DOI: 10.1021/acs.jcim.0c01126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cryptic pockets are visible in ligand-bound protein structures but are occluded in unbound structures. Utilizing these pockets in fragment-based drug-design provides an attractive option for proteins not tractable by classical binding sites. However, owing to their hidden nature, they are difficult to identify. Here, we show that small glycols find cryptic pockets on a diverse set of proteins. Initial crystallography experiments serendipitously revealed the ability of ethylene glycol, a small glycol, to identify a cryptic pocket on the W6A mutant of the RBSX protein (RBSX-W6A). Explicit-solvent molecular dynamics (MD) simulations of RBSX-W6A with the exposed state of the cryptic pocket (ethylene glycol removed) revealed closure of the pocket reiterating that the exposed state of cryptic pockets in general are unstable in the absence of ligands. Also, no change in the pocket was observed for simulations of RBSX-W6A with the occluded state of the cryptic pocket, suggesting that water molecules are not able to open the cryptic pocket. "Cryptic-pocket finding" potential of small glycols was then supported and generalized through additional crystallography experiments, explicit-cosolvent MD simulations, and protein data set construction and analysis. The cryptic pocket on RBSX-W6A was found again upon repeating the crystallography experiments with another small glycol, propylene glycol. Use of ethylene glycol as a probe molecule in cosolvent MD simulations led to the enhanced sampling of the exposed state of experimentally observed cryptic sites on a test set of two proteins (Niemann-Pick C2, Interleukin-2). Further, analyses of protein structures with validated cryptic sites showed that ethylene glycol molecules bind to sites on proteins (Bcl-xL, G-actin, myosin II, and glutamate receptor 2), which become apparent upon binding of biologically relevant ligands. Our study thus suggests potential application of the small glycols in experimental and computational fragment-based approaches to identify cryptic pockets in apparently undruggable and/or difficult targets, making these proteins amenable to drug-design strategies.
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Affiliation(s)
- Harsh Bansia
- Department of Physics, Indian Institute of Science, Bengaluru 560012, India
| | - Pranjal Mahanta
- Department of Physics, Indian Institute of Science, Bengaluru 560012, India
| | - Neela H Yennawar
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, State College, Pennsylvania 16802, United States
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24
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Juhl AD, Lund FW, Jensen MLV, Szomek M, Heegaard CW, Guttmann P, Werner S, McNally J, Schneider G, Kapishnikov S, Wüstner D. Niemann Pick C2 protein enables cholesterol transfer from endo-lysosomes to the plasma membrane for efflux by shedding of extracellular vesicles. Chem Phys Lipids 2021; 235:105047. [PMID: 33422548 DOI: 10.1016/j.chemphyslip.2020.105047] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 12/28/2020] [Indexed: 10/22/2022]
Abstract
The Niemann-Pick C2 protein (NPC2) is a sterol transfer protein in the lumen of late endosomes and lysosomes (LE/LYSs). Absence of functional NPC2 leads to endo-lysosomal buildup of cholesterol and other lipids. How NPC2's known capacity to transport cholesterol between model membranes is linked to its function in living cells is not known. Using quantitative live-cell imaging combined with modeling of the efflux kinetics, we show that NPC2-deficient human fibroblasts can export the cholesterol analog dehydroergosterol (DHE) from LE/LYSs. Internalized NPC2 accelerated sterol efflux extensively, accompanied by reallocation of LE/LYSs containing fluorescent NPC2 and DHE to the cell periphery. Using quantitative fluorescence loss in photobleaching of TopFluor-cholesterol (TF-Chol), we estimate a residence time for a rapidly exchanging sterol pool in LE/LYSs localized in close proximity to the plasma membrane (PM), of less than one min and observed non-vesicular sterol exchange between LE/LYSs and the PM. Excess sterol was released from the PM by shedding of cholesterol-rich vesicles. The ultrastructure of such vesicles was analyzed by combined fluorescence and cryo soft X-ray tomography (SXT), revealing that they can contain lysosomal cargo and intraluminal vesicles. Treating cells with apoprotein A1 and with nuclear receptor liver X-receptor (LXR) agonists to upregulate expression of ABC transporters enhanced cholesterol efflux from the PM, at least partly by accelerating vesicle release. We conclude that NPC2 inside LE/LYSs facilitates non-vesicular sterol exchange with the PM for subsequent sterol efflux to acceptor proteins and for shedding of sterol-rich vesicles from the cell surface.
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Affiliation(s)
- Alice Dupont Juhl
- Department of Biochemistry and Molecular Biology, VILLUM Center for Bioanalytical Sciences, University of Southern Denmark, DK-5230, Odense M, Denmark
| | - Frederik W Lund
- Department of Biochemistry and Molecular Biology, VILLUM Center for Bioanalytical Sciences, University of Southern Denmark, DK-5230, Odense M, Denmark
| | - Maria Louise V Jensen
- Department of Biochemistry and Molecular Biology, VILLUM Center for Bioanalytical Sciences, University of Southern Denmark, DK-5230, Odense M, Denmark
| | - Maria Szomek
- Department of Biochemistry and Molecular Biology, VILLUM Center for Bioanalytical Sciences, University of Southern Denmark, DK-5230, Odense M, Denmark
| | - Christian W Heegaard
- Department of Molecular Biology and Genetics, University of Aarhus, DK-8000, Aarhus C, Denmark
| | - Peter Guttmann
- Department X-Ray Microscopy, Helmholtz-Zentrum Berlin, Albert-Einstein-Str. 15, 12489, Berlin, Germany
| | - Stephan Werner
- Department X-Ray Microscopy, Helmholtz-Zentrum Berlin, Albert-Einstein-Str. 15, 12489, Berlin, Germany
| | - James McNally
- Department X-Ray Microscopy, Helmholtz-Zentrum Berlin, Albert-Einstein-Str. 15, 12489, Berlin, Germany
| | - Gerd Schneider
- Department X-Ray Microscopy, Helmholtz-Zentrum Berlin, Albert-Einstein-Str. 15, 12489, Berlin, Germany
| | - Sergey Kapishnikov
- Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark
| | - Daniel Wüstner
- Department of Biochemistry and Molecular Biology, VILLUM Center for Bioanalytical Sciences, University of Southern Denmark, DK-5230, Odense M, Denmark.
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25
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Zhu DX, Li L, Xu ZQ, Zhang C, Zhang JS, Sun JL, Wei JF. Cat-NPC2, a Newly Identified Allergen, With High Cross-Reactivity to Can f 7. ALLERGY, ASTHMA & IMMUNOLOGY RESEARCH 2021; 13:122-140. [PMID: 33191681 PMCID: PMC7680833 DOI: 10.4168/aair.2021.13.1.122] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 05/21/2020] [Accepted: 06/15/2020] [Indexed: 12/20/2022]
Abstract
Purpose Pet-derived allergens are the common indoor inhalant allergens. Among them, cat and dog allergens constitute more than 80% of animal allergic patients, which greatly affect the quality-of-life of patients and increase the burden of social health care. The aim of this study was to identify Cat-Niemann pick type C2 (NPC2) protein, a homologue of Can f 7, as a new allergen. Methods Cat-NPC2 complementary DNA (cDNA) was cloned and optimized for amplification and expression in Escherichia coli. Then, recombinant Cat-NPC2 (rCat-NPC2) was purified by Ni2+ affinity chromatography. The allergenicity was assessed by enzyme-linked immunosorbent assay (ELISA), western blot and basophil activation test (BAT). Based on the sequence similarity, the cross-reactivity between Cat-NPC2 and Can f 7 was investigated by inhibition ELISA. Circular dichroism spectroscopy and homology modeling were used to characterize the structure of Cat-NPC2. Results The cDNA sequence of Cat-NPC2 was cloned with a 450-bp open reading frame coding for 149 amino acids (GenBank MN_737596). The condon-optimized NPC2 gene was subcloned and expressed in E. coli with a molecular weight of 18.9 kDa. The native Cat-NPC2 was detected in cat dander extracts. The allergenicity determined by ELISA, western blot and BAT suggested at least 14.5% cat-allergic patients displayed high specific immunoglobulin E (IgE) recognition of Cat-NPC2. The predicted structure of Cat-NPC2 was found to consist of 7 β-strands arranged in 2 β-sheets. An ELISA based assay showed that rCat-NPC2 bound to cholesterol in a dose dependent manner. Based on the structure and sequence similarities, IgE cross-reactivity was demonstrated between Cat-NPC2 and Can f 7/Der f 2. Conclusions In the study, a novel cat allergen, belonging to the NPC2 protein family, was identified and characterized at both molecular and immunological levels. The study will offer a deeper understanding of cat allergens and improve a component-resolved diagnosis in pet allergy.
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Affiliation(s)
- Dan Xuan Zhu
- Women & Children Central Laboratory, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Lin Li
- Department of Emergency Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Zhi Qiang Xu
- Research Division of Clinical Pharmacology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Cheng Zhang
- Women & Children Central Laboratory, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Jin Song Zhang
- Department of Emergency Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
| | - Jin Lyu Sun
- Department of Allergy, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
| | - Ji Fu Wei
- Research Division of Clinical Pharmacology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
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26
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Moesgaard L, Petersen D, Szomek M, Reinholdt P, Winkler MBL, Frain KM, Müller P, Pedersen BP, Kongsted J, Wüstner D. Mechanistic Insight into Lipid Binding to Yeast Niemann Pick Type C2 Protein. Biochemistry 2020; 59:4407-4420. [PMID: 33141558 DOI: 10.1021/acs.biochem.0c00574] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Niemann Pick type C2 (NPC2) is a small sterol binding protein in the lumen of late endosomes and lysosomes. We showed recently that the yeast homologue of NPC2 together with its binding partner NCR1 mediates integration of ergosterol, the main sterol in yeast, into the vacuolar membrane. Here, we study the binding specificity and the molecular details of lipid binding to yeast NPC2. We find that NPC2 binds fluorescence- and spin-labeled analogues of phosphatidylcholine (PC), phosphatidylserine, phosphatidylinositol (PI), and sphingomyelin. Spectroscopic experiments show that NPC2 binds lipid monomers in solution but can also interact with lipid analogues in membranes. We further identify ergosterol, PC, and PI as endogenous NPC2 ligands. Using molecular dynamics simulations, we show that NPC2's binding pocket can adapt to the ligand shape and closes around bound ergosterol. Hydrophobic interactions stabilize the binding of ergosterol, but binding of phospholipids is additionally stabilized by electrostatic interactions at the mouth of the binding site. Our work identifies key residues that are important in stabilizing the binding of a phospholipid to yeast NPC2, thereby rationalizing future mutagenesis studies. Our results suggest that yeast NPC2 functions as a general "lipid solubilizer" and binds a variety of amphiphilic lipid ligands, possibly to prevent lipid micelle formation inside the vacuole.
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Affiliation(s)
- Laust Moesgaard
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Daniel Petersen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Maria Szomek
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Peter Reinholdt
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Mikael B L Winkler
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, Aarhus C 8000, Denmark
| | - Kelly May Frain
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, Aarhus C 8000, Denmark
| | - Peter Müller
- Department of Biology, Humboldt University Berlin, Unter den Linden 6, 10099 Berlin, Germany
| | - Bjørn Panyella Pedersen
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, Aarhus C 8000, Denmark
| | - Jacob Kongsted
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Daniel Wüstner
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
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27
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Iida S, Nakamura HK, Mashimo T, Fukunishi Y. Structural Fluctuations of Aromatic Residues in an Apo-Form Reveal Cryptic Binding Sites: Implications for Fragment-Based Drug Design. J Phys Chem B 2020; 124:9977-9986. [PMID: 33140952 DOI: 10.1021/acs.jpcb.0c04963] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Cryptic sites are binding pockets that are transiently formed in an apo form or that are induced by ligand binding. The investigation of cryptic sites is crucial for drug discovery, since these sites are ubiquitous in disease-related human proteins, and targeting them expands the number of drug targets greatly. However, although many computational studies have attempted to identify cryptic sites, the detection remains challenging. Here, we aimed to characterize and detect cryptic sites in terms of structural fluctuations in an apo form, investigating proteins each of which possesses a cryptic site. From their X-ray structures, we saw that aromatic residues tended to be found in cryptic sites. To examine structural fluctuations of the apo forms, we performed molecular dynamics (MD) simulations, producing probability distributions of the solvent-accessible surface area per aromatic residue. To detect aromatic residues in cryptic sites, we have proposed a "cryptic-site index" based on the distribution, demonstrating the performance via several measures, such as recall and specificity. Besides, we found that high-ranking aromatic residues were likely to probe concaves in a cryptic site. This implies that such fluctuations provide a profile of scaffolds of compounds with the potential to bind to a particular cryptic site.
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Affiliation(s)
- Shinji Iida
- Technology Research Association for Next-Generation Natural Products Chemistry, 2-3-26, Aomi, Koto-ku, Tokyo 135-0064, Japan
| | - Hironori K Nakamura
- Biomodeling Research Co., Ltd., 1-704-2, Uedanishi, Tenpaku-ku, Nagoya, Aichi 468-0058, Japan
| | - Tadaaki Mashimo
- Technology Research Association for Next-Generation Natural Products Chemistry, 2-3-26, Aomi, Koto-ku, Tokyo 135-0064, Japan.,IMSBIO Co., Ltd., 4-21-1, Higashiikebukuro, Toshima-ku, Tokyo 170-0013, Japan
| | - Yoshifumi Fukunishi
- Cellular and Molecular Biotechnology Research Institute, AIST Tokyo Waterfront, 2-3-26 Aomi, Koto-ku, Tokyo 135-0064, Japan
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28
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Araki T, Osaka J, Kato Y, Shimozono M, Kawamura H, Iwanaga R, Hakeda-Suzuki S, Suzuki T. Systematic identification of genes regulating synaptic remodeling in the Drosophila visual system. Genes Genet Syst 2020; 95:101-110. [PMID: 32493879 DOI: 10.1266/ggs.19-00066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
In many animals, neural activity contributes to the adaptive refinement of synaptic properties, such as firing frequency and the number of synapses, for learning, memorizing and adapting for survival. However, the molecular mechanisms underlying such activity-dependent synaptic remodeling remain largely unknown. In the synapses of Drosophila melanogaster, the presynaptic active zone (AZ) forms a T-shaped presynaptic density comprising AZ proteins, including Bruchpilot (Brp). In a previous study, we found that the signal from a fusion protein molecular marker consisting of Brp and mCherry becomes diffuse under continuous light over three days (LL), reflecting disassembly of the AZ, while remaining punctate under continuous darkness. To identify the molecular players controlling this synaptic remodeling, we used the fusion protein molecular marker and performed RNAi screening against 208 neuron-related transmembrane genes that are highly expressed in the Drosophila visual system. Second analyses using the STaR (synaptic tagging with recombination) technique, which showed a decrease in synapse number under the LL condition, and subsequent mutant and overexpression analysis confirmed that five genes are involved in the activity-dependent AZ disassembly. This work demonstrates the feasibility of identifying genes involved in activity-dependent synaptic remodeling in Drosophila, and also provides unexpected insight into the molecular mechanisms involved in cholesterol metabolism and biosynthesis of the insect molting hormone ecdysone.
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Affiliation(s)
- Tomohiro Araki
- Graduate School of Life Science and Technology, Tokyo Institute of Technology
| | - Jiro Osaka
- Graduate School of Life Science and Technology, Tokyo Institute of Technology
| | - Yuya Kato
- Graduate School of Life Science and Technology, Tokyo Institute of Technology
| | - Mai Shimozono
- Graduate School of Life Science and Technology, Tokyo Institute of Technology
| | - Hinata Kawamura
- Graduate School of Life Science and Technology, Tokyo Institute of Technology
| | - Riku Iwanaga
- Graduate School of Life Science and Technology, Tokyo Institute of Technology
| | | | - Takashi Suzuki
- Graduate School of Life Science and Technology, Tokyo Institute of Technology
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29
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Single Cell Transcriptome Analysis of Niemann-Pick Disease, Type C1 Cerebella. Int J Mol Sci 2020; 21:ijms21155368. [PMID: 32731618 PMCID: PMC7432835 DOI: 10.3390/ijms21155368] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 07/23/2020] [Accepted: 07/24/2020] [Indexed: 12/18/2022] Open
Abstract
Niemann-Pick disease, type C1 (NPC1) is a lysosomal disease characterized by endolysosomal storage of unesterified cholesterol and decreased cellular cholesterol bioavailability. A cardinal symptom of NPC1 is cerebellar ataxia due to Purkinje neuron loss. To gain an understanding of the cerebellar neuropathology we obtained single cell transcriptome data from control (Npc1+/+) and both three-week-old presymptomatic and seven-week-old symptomatic mutant (Npc1-/-) mice. In seven-week-old Npc1-/- mice, differential expression data was obtained for neuronal, glial, vascular, and myeloid cells. As anticipated, we observed microglial activation and increased expression of innate immunity genes. We also observed increased expression of innate immunity genes by other cerebellar cell types, including Purkinje neurons. Whereas neuroinflammation mediated by microglia may have both neuroprotective and neurotoxic components, the contribution of increased expression of these genes by non-immune cells to NPC1 pathology is not known. It is possible that dysregulated expression of innate immunity genes by non-immune cells is neurotoxic. We did not anticipate a general lack of transcriptomic changes in cells other than microglia from presymptomatic three-week-old Npc1-/- mice. This observation suggests that microglia activation precedes neuronal dysfunction. The data presented in this paper will be useful for generating testable hypotheses related to disease progression and Purkinje neurons loss as well as providing insight into potential novel therapeutic interventions.
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30
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Seker Yilmaz B, Baruteau J, Rahim AA, Gissen P. Clinical and Molecular Features of Early Infantile Niemann Pick Type C Disease. Int J Mol Sci 2020; 21:E5059. [PMID: 32709131 PMCID: PMC7404201 DOI: 10.3390/ijms21145059] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 07/14/2020] [Accepted: 07/15/2020] [Indexed: 12/22/2022] Open
Abstract
Niemann Pick disease type C (NPC) is a neurovisceral disorder due to mutations in NPC1 or NPC2. This review focuses on poorly characterized clinical and molecular features of early infantile form of NPC (EIF) and identified 89 cases caused by NPC1 (NPC1) and 16 by NPC2 (NPC2) mutations. Extra-neuronal features were common; visceromegaly reported in 80/89 NPC1 and in 15/16 NPC2, prolonged jaundice in 30/89 NPC1 and 7/16 NPC2. Early lung involvement was present in 12/16 NPC2 cases. Median age of neurological onset was 12 (0-24) and 7.5 (0-24) months in NPC1 and NPC2 groups, respectively. Developmental delay and hypotonia were the commonest first detected neurological symptoms reported in 39/89 and 18/89 NPC1, and in 8/16 and 10/16 NPC2, respectively. Additional neurological symptoms included vertical supranuclear gaze palsy, dysarthria, cataplexy, dysphagia, seizures, dystonia, and spasticity. The following mutations in homozygous state conferred EIF: deletion of exon 1+promoter, c.3578_3591 + 9del, c.385delT, p.C63fsX75, IVS21-2delATGC, c. 2740T>A (p.C914S), c.3584G>T (p.G1195V), c.3478-6T>A, c.960_961dup (p.A321Gfs*16) in NPC1 and c.434T>A (p.V145E), c.199T>C (p.S67P), c.133C>T (p.Q45X), c.141C>A (p.C47X) in NPC2. This comprehensive analysis of the EIF type of NPC will benefit clinical patient management, genetic counselling, and assist design of novel therapy trials.
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Affiliation(s)
- Berna Seker Yilmaz
- Genetics and Genomic Medicine Department, Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK; (J.B.); (P.G.)
- Department of Paediatric Metabolic Medicine, Mersin University, Mersin 33110, Turkey
| | - Julien Baruteau
- Genetics and Genomic Medicine Department, Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK; (J.B.); (P.G.)
- National Institute of Health Research Great Ormond Street Biomedical Research Centre, London WC1N 1EH, UK
- Metabolic Medicine Department, Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK
| | - Ahad A. Rahim
- UCL School of Pharmacy, University College London, London WC1N 1AX, UK;
| | - Paul Gissen
- Genetics and Genomic Medicine Department, Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK; (J.B.); (P.G.)
- National Institute of Health Research Great Ormond Street Biomedical Research Centre, London WC1N 1EH, UK
- Metabolic Medicine Department, Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK
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31
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Structural Basis of Low-pH-Dependent Lysosomal Cholesterol Egress by NPC1 and NPC2. Cell 2020; 182:98-111.e18. [DOI: 10.1016/j.cell.2020.05.020] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 03/16/2020] [Accepted: 05/11/2020] [Indexed: 01/19/2023]
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32
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Existence and distribution of Niemann-Pick type 2C (NPC2) in prawn reproductive tract and its putative role as a cholesterol modulator during sperm transit in the vas deferens. Cell Tissue Res 2020; 382:381-390. [PMID: 32556727 DOI: 10.1007/s00441-020-03225-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 04/27/2020] [Indexed: 10/24/2022]
Abstract
Sequestering of cholesterol (CHO) is a hallmark molecular event that is known to be associated with sperm gaining their fertilizing ability in a broad array of animals. We have shown previously that the level of CHO declines in the Macrobrachium rosenbergii sperm membrane when they are migrating into the vas deferens, prompting us to search for CHO transporters, one of which is Niemann-Pick type 2C (NPC2), within the prawn male reproductive tract. Sequence comparison of MrNPC2 with other NPC2, from crustaceans to mammals, revealed its conserved features in the hydrophobic cavity with 3 amino acids forming a CHO lid that is identical in all species analyzed. Expressions of MrNPC2 transcript and protein were detected in testicular supporting and interstitial cells and along the epithelial cells of the vas deferens. As confirmed by live cell staining, the testicular sperm (Tsp) surface was devoid of MrNPC2 but it first existed on the vas deferens sperm, suggesting its acquisition from the luminal fluid, possibly through trafficking of multi-lamellar vesicles during sperm transit in the vas deferens. We further showed that recombinant MrNPC2 had a high affinity towards CHO in the lipid extracts, either from Tsp or from lipid vesicles in the vas deferens. Together, our results indicated the presence of MrNPC2 in the male reproductive tract, which may play an important role as a CHO modulator between the sperm membrane and vas deferens epithelial communication.
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33
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Ke XX, Chao H, Abbas MN, Kausar S, Gul I, Ji H, Yang L, Cui H. Niemann-Pick type C1 regulates cholesterol transport and metamorphosis in silkworm, Bombyx mori (Dazao). Int J Biol Macromol 2020; 152:525-534. [DOI: 10.1016/j.ijbiomac.2020.02.296] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 02/07/2020] [Accepted: 02/25/2020] [Indexed: 01/29/2023]
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34
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Saha P, Shumate JL, Caldwell JG, Elghobashi-Meinhardt N, Lu A, Zhang L, Olsson NE, Elias JE, Pfeffer SR. Inter-domain dynamics drive cholesterol transport by NPC1 and NPC1L1 proteins. eLife 2020; 9:e57089. [PMID: 32410728 PMCID: PMC7228765 DOI: 10.7554/elife.57089] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 04/25/2020] [Indexed: 01/17/2023] Open
Abstract
Transport of LDL-derived cholesterol from lysosomes into the cytoplasm requires NPC1 protein; NPC1L1 mediates uptake of dietary cholesterol. We introduced single disulfide bonds into NPC1 and NPC1L1 to explore the importance of inter-domain dynamics in cholesterol transport. Using a sensitive method to monitor lysosomal cholesterol efflux, we found that NPC1's N-terminal domain need not release from the rest of the protein for efficient cholesterol export. Either introducing single disulfide bonds to constrain lumenal/extracellular domains or shortening a cytoplasmic loop abolishes transport activity by both NPC1 and NPC1L1. The widely prescribed cholesterol uptake inhibitor, ezetimibe, blocks NPC1L1; we show that residues that lie at the interface between NPC1L1's three extracellular domains comprise the drug's binding site. These data support a model in which cholesterol passes through the cores of NPC1/NPC1L1 proteins; concerted movement of various domains is needed for transfer and ezetimibe blocks transport by binding to multiple domains simultaneously.
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Affiliation(s)
- Piyali Saha
- Department of Biochemistry, Stanford University School of MedicineStanfordUnited States
| | - Justin L Shumate
- Department of Biochemistry, Stanford University School of MedicineStanfordUnited States
| | - Jenna G Caldwell
- Department of Biochemistry, Stanford University School of MedicineStanfordUnited States
| | | | - Albert Lu
- Department of Biochemistry, Stanford University School of MedicineStanfordUnited States
| | | | - Niclas E Olsson
- Department of Chemical and Systems Biology, Stanford University School of MedicineStanfordUnited States
| | | | - Suzanne R Pfeffer
- Department of Biochemistry, Stanford University School of MedicineStanfordUnited States
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35
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Ouweneel AB, Thomas MJ, Sorci-Thomas MG. The ins and outs of lipid rafts: functions in intracellular cholesterol homeostasis, microparticles, and cell membranes: Thematic Review Series: Biology of Lipid Rafts. J Lipid Res 2020; 61:676-686. [PMID: 33715815 PMCID: PMC7193959 DOI: 10.1194/jlr.tr119000383] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 12/17/2019] [Indexed: 12/12/2022] Open
Abstract
Cellular membranes are not homogenous mixtures of proteins; rather, they are segregated into microdomains on the basis of preferential association between specific lipids and proteins. These microdomains, called lipid rafts, are well known for their role in receptor signaling on the plasma membrane (PM) and are essential to such cellular functions as signal transduction and spatial organization of the PM. A number of disease states, including atherosclerosis and other cardiovascular disorders, may be caused by dysfunctional maintenance of lipid rafts. Lipid rafts do not occur only in the PM but also have been found in intracellular membranes and extracellular vesicles (EVs). Here, we focus on discussing newly discovered functions of lipid rafts and microdomains in intracellular membranes, including lipid and protein trafficking from the ER, Golgi bodies, and endosomes to the PM, and we examine lipid raft involvement in the production and composition of EVs. Because lipid rafts are small and transient, visualization remains challenging. Future work with advanced techniques will continue to expand our knowledge about the roles of lipid rafts in cellular functioning.
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Affiliation(s)
- Amber B Ouweneel
- Department of Medicine, Division of Endocrinology and Molecular Medicine,Medical College of Wisconsin, Milwaukee, WI 53226; Cardiovascular Center,Medical College of Wisconsin, Milwaukee, WI 53226
| | - Michael J Thomas
- Cardiovascular Center,Medical College of Wisconsin, Milwaukee, WI 53226; Department of Pharmacology and Toxicology,Medical College of Wisconsin, Milwaukee, WI 53226
| | - Mary G Sorci-Thomas
- Department of Medicine, Division of Endocrinology and Molecular Medicine,Medical College of Wisconsin, Milwaukee, WI 53226; Cardiovascular Center,Medical College of Wisconsin, Milwaukee, WI 53226; Department of Pharmacology and Toxicology,Medical College of Wisconsin, Milwaukee, WI 53226. mailto:
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36
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Yagi H, Nishigori M, Murakami Y, Osaki T, Muto S, Iba Y, Minatoya K, Ikeda Y, Ishibashi-Ueda H, Morisaki T, Ogino H, Tanaka H, Sasaki H, Matsuda H, Minamino N. Discovery of novel biomarkers for atherosclerotic aortic aneurysm through proteomics-based assessment of disease progression. Sci Rep 2020; 10:6429. [PMID: 32286426 PMCID: PMC7156426 DOI: 10.1038/s41598-020-63229-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 03/25/2020] [Indexed: 01/21/2023] Open
Abstract
Since aortic aneurysms (AAs) are mostly asymptomatic, but they have a high mortality rate upon rupture, their detection and progression evaluation are clinically important issues. To discover diagnostic biomarkers for AA, we performed proteome analysis of aortic media from patients with thoracic atherosclerotic AA (TAAA), comparing protein levels between the aneurysm and normal tissue areas. After hierarchical clustering analysis of the proteome analysis data, tissue samples were classified into three groups, regardless of morphological features. This classification was shown to reflect disease progression stage identified by pathological examination. This proteomics-based staging system enabled us to identify more significantly altered proteins than the morphological classification system. In subsequent data analysis, Niemann-Pick disease type C2 protein (NPC2) and insulin-like growth factor-binding protein 7 (IGFBP7) were selected as novel biomarker candidates for AA and were compared with the previously reported biomarker, thrombospondin 1 (THBS1). Blood concentrations of NPC2 and IGFBP7 were significantly increased, while THBS1 levels were decreased in TAAA and abdominal atherosclerotic AA patients. Receiver operating characteristic analysis of AA patients and healthy controls showed that NPC2 and IGFBP7 have higher specificity and sensitivity than THBS1. Thus, NPC2 and IGFBP7 are promising biomarkers for the detection and progression evaluation of AA.
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Affiliation(s)
- Hiroaki Yagi
- Department of Molecular Pharmacology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
| | - Mitsuhiro Nishigori
- Department of Molecular Pharmacology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan.,Omics Research Center, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan
| | - Yusuke Murakami
- Omics Research Center, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan
| | - Tsukasa Osaki
- Department of Molecular Pharmacology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
| | - Sayaka Muto
- Omics Research Center, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan.,Department of Pathology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan
| | - Yutaka Iba
- Department of Vascular Surgery, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan
| | - Kenji Minatoya
- Department of Vascular Surgery, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan
| | - Yoshihiko Ikeda
- Department of Pathology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan
| | - Hatsue Ishibashi-Ueda
- Department of Pathology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan
| | - Takayuki Morisaki
- Department of Bioscience and Genetics, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
| | - Hitoshi Ogino
- Department of Vascular Surgery, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan
| | - Hiroshi Tanaka
- Department of Vascular Surgery, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan
| | - Hiroaki Sasaki
- Department of Vascular Surgery, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan
| | - Hitoshi Matsuda
- Department of Vascular Surgery, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan
| | - Naoto Minamino
- Department of Molecular Pharmacology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan. .,Omics Research Center, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan.
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37
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Hede E, Christiansen CB, Heegaard CW, Moos T, Burkhart A. Gene therapy to the blood-brain barrier with resulting protein secretion as a strategy for treatment of Niemann Picks type C2 disease. J Neurochem 2020; 156:290-308. [PMID: 32072649 DOI: 10.1111/jnc.14982] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 01/15/2020] [Accepted: 02/10/2020] [Indexed: 12/11/2022]
Abstract
Treatment of many diseases affecting the central nervous system (CNS) is complicated by the inability of several therapeutics to cross the blood-brain barrier (BBB). Genetically modifying brain capillary endothelial cells (BCECs) denotes an approach to overcome the limitations of the BBB by turning BCECs into recombinant protein factories. This will result in protein secretion toward both the brain and peripheral circulation, which is particularly relevant in genetic diseases, like lysosomal storage diseases (LSD), where cells are ubiquitously affected both in the CNS and the periphery. Here we investigated transfection of primary rat brain capillary endothelial cells (rBCECs) for synthesis and secretion of recombinant NPC2, the protein deficient in the lysosomal cholesterol storage disease Niemann Pick type C2. We demonstrate prominent NPC2 gene induction and protein secretion in 21% of BCECs in non-mitotic monocultures with a biological effect on NPC2-deficient fibroblasts as verified from changes in filipin III staining of cholesterol deposits. By comparison the transfection efficiency was 75% in HeLa-cells, known to persist in a mitotic state. When co-cultured with primary rat astrocytes in conditions with maintained BBB properties 7% BCECs were transfected, clearly suggesting that induction of BBB properties with polarized conditions of the non-mitotic BCECs influences the transfection efficacy and secretion directionality. In conclusion, non-viral gene therapy to rBCECs leads to protein secretion and signifies a method for NPC2 to target cells inside the CNS otherwise inaccessible because of the presence of the BBB. However, obtaining high transfection efficiencies is crucial in order to achieve sufficient therapeutic effects. Cover Image for this issue: https://doi.org/10.1111/jnc.15050.
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Affiliation(s)
- Eva Hede
- Laboratory of Neurobiology, Biomedicine Group, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Christine B Christiansen
- Laboratory of Neurobiology, Biomedicine Group, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Christian W Heegaard
- Department of Molecular Biology and Genetics - Molecular Nutrition, Aarhus University, Aarhus, Denmark
| | - Torben Moos
- Laboratory of Neurobiology, Biomedicine Group, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Annette Burkhart
- Laboratory of Neurobiology, Biomedicine Group, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
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38
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New variants in Spanish Niemann–Pick type c disease patients. Mol Biol Rep 2020; 47:2085-2095. [DOI: 10.1007/s11033-020-05308-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 02/06/2020] [Indexed: 01/26/2023]
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39
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Cawley NX, Sojka C, Cougnoux A, Lyons AT, Nicoli E, Wassif CA, Porter FD. Abnormal LAMP1 glycosylation may play a role in Niemann-Pick disease, type C pathology. PLoS One 2020; 15:e0227829. [PMID: 31999726 PMCID: PMC6992233 DOI: 10.1371/journal.pone.0227829] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 12/30/2019] [Indexed: 12/20/2022] Open
Abstract
A hallmark of Niemann-Pick disease, type C (NPC) is the progressive degeneration of Purkinje neurons in the cerebellum caused by the accumulation of free cholesterol and glycosphingolipids in the lysosome. Recent studies suggest that the state of glycosylation of lysosomal membrane proteins may play a role in disease progression. Our study has identified the presence of a highly glycosylated form of Lysosome Associated Membrane Protein 1 (LAMP1) that correlated spatiotemporally with Purkinje neuron loss. This form of LAMP1 was predominantly localized to activated microglia; showing a ~5-fold increase in surface labeling by FACS analysis. This suggests a potential role for LAMP1 in the neuro-inflammatory process in these mice during disease progression. Analysis of other mouse models of neurodegeneration that exhibit neuro-inflammation showed little or no presence of this glycosylated form of LAMP1, suggesting this observation for LAMP1 is specific to NPC disease. Furthermore, early treatment of Npc1-/- mice with 2-hydroxypropyl-β-cyclodextrin (HPβCD), significantly prevented the appearance of the glycosylated LAMP1 in the cerebellum of Npc1-/- mice at 7 weeks, consistent with the prevention of neuro-inflammation in mice treated with this drug. Treatment of Npc1-/- mice with HPβCD at 7 weeks, after disease onset, did not reverse or prevent further appearance of the hyperglycosylated LAMP1, demonstrating that once this aspect of neuro-inflammation began, it continued despite the HPβCD treatment. Analysis of LAMP1 in cerebellar tissue of NPC1 patients showed a small level of hyperglycosylated LAMP1 in the tissue, however, this was not seen in the CSF of patients.
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Affiliation(s)
- Niamh X. Cawley
- Section on Molecular Dysmorphology, Division of Translational Medicine, Department of Health and Human Services, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States of America
| | - Caitlin Sojka
- Section on Molecular Dysmorphology, Division of Translational Medicine, Department of Health and Human Services, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States of America
| | - Antony Cougnoux
- Section on Molecular Dysmorphology, Division of Translational Medicine, Department of Health and Human Services, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States of America
| | - Anna T. Lyons
- Section on Molecular Dysmorphology, Division of Translational Medicine, Department of Health and Human Services, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States of America
| | - Elena‐Raluca Nicoli
- Department of Health and Human Services, Pediatric Undiagnosed Diseases Program, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, United States of America
| | - Christopher A. Wassif
- Section on Molecular Dysmorphology, Division of Translational Medicine, Department of Health and Human Services, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States of America
| | - Forbes D. Porter
- Section on Molecular Dysmorphology, Division of Translational Medicine, Department of Health and Human Services, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States of America
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40
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Jing X, Behmer ST. Insect Sterol Nutrition: Physiological Mechanisms, Ecology, and Applications. ANNUAL REVIEW OF ENTOMOLOGY 2020; 65:251-271. [PMID: 31600456 DOI: 10.1146/annurev-ento-011019-025017] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Insects, like all eukaryotes, require sterols for structural and metabolic purposes. However, insects, like all arthropods, cannot make sterols. Cholesterol is the dominant tissue sterol for most insects; insect herbivores produce cholesterol by metabolizing phytosterols, but not always with high efficiency. Many insects grow on a mixed-sterol diet, but this ability varies depending on the types and ratio of dietary sterols. Dietary sterol uptake, transport, and metabolism are regulated by several proteins and processes that are relatively conserved across eukaryotes. Sterol requirements also impact insect ecology and behavior. There is potential to exploit insect sterol requirements to (a) control insect pests in agricultural systems and (b) better understand sterol biology, including in humans. We suggest that future studies focus on the genetic mechanism of sterol metabolism and reverse transportation, characterizing sterol distribution and function at the cellular level, the role of bacterial symbionts in sterol metabolism, and interrupting sterol trafficking for pest control.
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Affiliation(s)
- Xiangfeng Jing
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China;
- Key Laboratory of Integrated Pest Management on Crops in Northwestern Loess Plateau, Ministry of Agriculture, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Spencer T Behmer
- Department of Entomology, Texas A&M University, College Station, Texas 77843, USA;
- Ecology & Evolutionary Biology Graduate Program, Texas A&M University, College Station, Texas 77843, USA
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41
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Wheeler S, Sillence DJ. Niemann-Pick type C disease: cellular pathology and pharmacotherapy. J Neurochem 2019; 153:674-692. [PMID: 31608980 DOI: 10.1111/jnc.14895] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 09/10/2019] [Accepted: 09/15/2019] [Indexed: 12/22/2022]
Abstract
Niemann-Pick type C disease (NPCD) was first described in 1914 and affects approximately 1 in 150 000 live births. It is characterized clinically by diverse symptoms affecting liver, spleen, motor control, and brain; premature death invariably results. Its molecular origins were traced, as late as 1997, to a protein of late endosomes and lysosomes which was named NPC1. Mutation or absence of this protein leads to accumulation of cholesterol in these organelles. In this review, we focus on the intracellular events that drive the pathology of this disease. We first introduce endocytosis, a much-studied area of dysfunction in NPCD cells, and survey the various ways in which this process malfunctions. We briefly consider autophagy before attempting to map the more complex pathways by which lysosomal cholesterol storage leads to protein misregulation, mitochondrial dysfunction, and cell death. We then briefly introduce the metabolic pathways of sphingolipids (as these emerge as key species for treatment) and critically examine the various treatment approaches that have been attempted to date.
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Affiliation(s)
- Simon Wheeler
- School of Pharmacy, De Montfort University, The Gateway, Leicester, UK
| | - Dan J Sillence
- School of Pharmacy, De Montfort University, The Gateway, Leicester, UK
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42
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McCauliff LA, Langan A, Li R, Ilnytska O, Bose D, Waghalter M, Lai K, Kahn PC, Storch J. Intracellular cholesterol trafficking is dependent upon NPC2 interaction with lysobisphosphatidic acid. eLife 2019; 8:50832. [PMID: 31580258 PMCID: PMC6855803 DOI: 10.7554/elife.50832] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Accepted: 10/02/2019] [Indexed: 12/12/2022] Open
Abstract
Unesterified cholesterol accumulation in the late endosomal/lysosomal (LE/LY) compartment is the cellular hallmark of Niemann-Pick C (NPC) disease, caused by defects in the genes encoding NPC1 or NPC2. We previously reported the dramatic stimulation of NPC2 cholesterol transport rates to and from model membranes by the LE/LY phospholipid lysobisphosphatidic acid (LBPA). It had been previously shown that enrichment of NPC1-deficient cells with LBPA results in cholesterol clearance. Here we demonstrate that LBPA enrichment in human NPC2-deficient cells, either directly or via its biosynthetic precursor phosphtidylglycerol (PG), is entirely ineffective, indicating an obligate functional interaction between NPC2 and LBPA in cholesterol trafficking. We further demonstrate that NPC2 interacts directly with LBPA and identify the NPC2 hydrophobic knob domain as the site of interaction. Together these studies reveal a heretofore unknown step of intracellular cholesterol trafficking which is critically dependent upon the interaction of LBPA with functional NPC2 protein. Cholesterol is a type of fat that is essential for many processes in the body, such as repairing damaged cells and producing certain hormones. Normally, cholesterol enters cells from the bloodstream and is then moved to the parts of the cell that need it via a process known as ‘trafficking’. When cholesterol trafficking goes wrong, abnormally large amounts of cholesterol and other fats accumulate within the cell. Over time, these fatty deposits become toxic to cells and eventually damage the affected tissues. Niemann-Pick type C disease (NPC) is a severe genetic disorder affecting cholesterol trafficking. It is characterized by cholesterol build-up in multiple tissues, including the brain, which ultimately causes degeneration and death of nerve cells. Two proteins, NPC1 and NPC2, are involved in NPC disease. Both proteins normally help move cholesterol out of important trafficking compartments (known as the endosomal and lysosomal compartments) to other areas of the cell where it is needed. Patients with the disease can have mutations in either the gene for NPC1 or the gene for NPC2. This means that cells from NPC1 patients do not make enough functional NPC1 protein (but contain working NPC2), and vice versa. Previous studies had shown that giving cells with NPC1 mutations large amounts of the small molecule lysobisphosphatidic acid (LBPA for short) could compensate for the loss of NPC1, and stop the toxic build-up of cholesterol. McCauliff, Langan, Li et al. therefore wanted to explore exactly how LBPA was doing this. They had shown that LBPA dramatically increased the ability of purified NPC2 protein to transport cholesterol, and wondered if the effect of LBPA in the cells without NPC1 depended on NPC2. They predicted that boosting LBPA levels would not work in cells lacking NPC2. Biochemical experiments using purified protein showed that LBPA and NPC2 did indeed interact directly with each other. Systematically changing different building blocks of NPC2 revealed that a single region of the protein is sensitive to LBPA, and when this region was altered, LBPA could no longer interact with NPC2. Since LBPA is naturally produced by cells, they then stimulated cells grown in the laboratory to generate more LBPA using its precursor phosphatidylglycerol. They used cells from patients with mutations in either NPC1 or NPC2 and demonstrated that LBPA’s ability to reverse the accumulation of cholesterol was dependent on its interaction with NPC2. Thus, increasing LBPA levels in cells from patients with NPC1 mutations was beneficial, but had no effect on cells from patients with NPC2 mutations. These results shed new light not only on how cells transport cholesterol, but also on potential methods to combat disorders of cellular cholesterol trafficking. In the future, LBPA could be developed as a genetically tailored, patient-specific therapy for diseases like NPC.
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Affiliation(s)
- Leslie A McCauliff
- Department of Nutritional Sciences, Rutgers University, New Brunswick, United States.,Rutgers Center for Lipid Research, Rutgers University, New Brunswick, United States
| | - Annette Langan
- Department of Nutritional Sciences, Rutgers University, New Brunswick, United States.,Rutgers Center for Lipid Research, Rutgers University, New Brunswick, United States
| | - Ran Li
- Department of Nutritional Sciences, Rutgers University, New Brunswick, United States.,Rutgers Center for Lipid Research, Rutgers University, New Brunswick, United States
| | - Olga Ilnytska
- Department of Nutritional Sciences, Rutgers University, New Brunswick, United States.,Rutgers Center for Lipid Research, Rutgers University, New Brunswick, United States
| | - Debosreeta Bose
- Department of Nutritional Sciences, Rutgers University, New Brunswick, United States.,Rutgers Center for Lipid Research, Rutgers University, New Brunswick, United States
| | - Miriam Waghalter
- Department of Nutritional Sciences, Rutgers University, New Brunswick, United States
| | - Kimberly Lai
- Department of Nutritional Sciences, Rutgers University, New Brunswick, United States
| | - Peter C Kahn
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, United States
| | - Judith Storch
- Department of Nutritional Sciences, Rutgers University, New Brunswick, United States.,Rutgers Center for Lipid Research, Rutgers University, New Brunswick, United States
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43
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Winkler MBL, Kidmose RT, Szomek M, Thaysen K, Rawson S, Muench SP, Wüstner D, Pedersen BP. Structural Insight into Eukaryotic Sterol Transport through Niemann-Pick Type C Proteins. Cell 2019; 179:485-497.e18. [PMID: 31543266 DOI: 10.1016/j.cell.2019.08.038] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 07/05/2019] [Accepted: 08/21/2019] [Indexed: 12/24/2022]
Abstract
Niemann-Pick type C (NPC) proteins are essential for sterol homeostasis, believed to drive sterol integration into the lysosomal membrane before redistribution to other cellular membranes. Here, using a combination of crystallography, cryo-electron microscopy, and biochemical and in vivo studies on the Saccharomyces cerevisiae NPC system (NCR1 and NPC2), we present a framework for sterol membrane integration. Sterols are transferred between hydrophobic pockets of vacuolar NPC2 and membrane-protein NCR1. NCR1 has its N-terminal domain (NTD) positioned to deliver a sterol to a tunnel connecting NTD to the luminal membrane leaflet 50 Å away. A sterol is caught inside this tunnel during transport, and a proton-relay network of charged residues in the transmembrane region is linked to this tunnel supporting a proton-driven transport mechanism. We propose a model for sterol integration that clarifies the role of NPC proteins in this essential eukaryotic pathway and that rationalizes mutations in patients with Niemann-Pick disease type C.
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Affiliation(s)
- Mikael B L Winkler
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, Aarhus C 8000, Denmark
| | - Rune T Kidmose
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, Aarhus C 8000, Denmark
| | - Maria Szomek
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, Odense M 5230, Denmark
| | - Katja Thaysen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, Odense M 5230, Denmark
| | - Shaun Rawson
- School of Biomedical Sciences and The Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Stephen P Muench
- School of Biomedical Sciences and The Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Daniel Wüstner
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, Odense M 5230, Denmark
| | - Bjørn Panyella Pedersen
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, Aarhus C 8000, Denmark; Aarhus Institute of Advanced Studies, Aarhus University, Høegh-Guldbergs Gade 6B, Aarhus C 8000, Denmark.
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44
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Petersen D, Reinholdt P, Szomek M, Hansen SK, Poongavanam V, Dupont A, Heegaard CW, Krishnan K, Fujiwara H, Covey DF, Ory DS, Kongsted J, Wüstner D. Binding and intracellular transport of 25-hydroxycholesterol by Niemann-Pick C2 protein. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1862:183063. [PMID: 31521631 DOI: 10.1016/j.bbamem.2019.183063] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 08/26/2019] [Accepted: 09/09/2019] [Indexed: 12/16/2022]
Abstract
Side-chain oxidized cholesterol derivatives, like 25-hydroxycholesterol (25-OH-Chol) are important regulators of cellular cholesterol homeostasis. How transport of oxysterols through the endo-lysosomal pathway contributes to their biological function is not clear. The Niemann-Pick C2 protein (NPC2) is a small lysosomal sterol transfer protein required for export of cholesterol from late endosomes and lysosomes (LE/LYSs). Here, we show that 25-hydroxy-cholestatrienol, (25-OH-CTL), an intrinsically fluorescent analogue of 25-OH-Chol, becomes trapped in LE/LYSs of NPC2-deficient fibroblasts, but can efflux from the cells even in the absence of NPC2 upon removal of the sterol source. Fluorescence recovery after photobleaching (FRAP) of 25-OH-CTL in endo-lysosomes was rapid and extensive and only partially dependent on NPC2 function. Using quenching of NPC2's intrinsic fluorescence, we show that 25-OH-Chol and 25-OH-CTL can bind to NPC2 though with lower affinity compared to cholesterol and its fluorescent analogues, cholestatrienol (CTL) and dehydroergosterol (DHE). This is confirmed by calculations of binding energies which additionally show that 25-OH-CTL can bind in two orientations to NPC2, in stark contrast to cholesterol and its analogues. We conclude that NPC2's affinity for all sterols is energetically favored over their self-aggregation in the lysosomal lumen. Lysosomal export of 25-OH-Chol is not strictly dependent on the NPC2 protein.
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Affiliation(s)
- Daniel Petersen
- Department of Biochemistry and Molecular Biology, DK-5230 Odense M, Denmark
| | - Peter Reinholdt
- Department of Physics, Chemistry and Pharmacy, DK-5230 Odense M, Denmark
| | - Maria Szomek
- Department of Biochemistry and Molecular Biology, DK-5230 Odense M, Denmark
| | | | | | - Alice Dupont
- Department of Biochemistry and Molecular Biology, DK-5230 Odense M, Denmark
| | - Christian W Heegaard
- Department of Molecular Biology and Genetics, University of Aarhus, DK-8000 Aarhus, C, Denmark
| | - Kathiresan Krishnan
- Department of Developmental Biology, Washington University, St. Louis, MO 63110, USA
| | - Hideji Fujiwara
- Department of Developmental Biology, Washington University, St. Louis, MO 63110, USA
| | - Douglas F Covey
- Department of Developmental Biology, Washington University, St. Louis, MO 63110, USA; Taylor Family Institute for Innovative Psychiatric Research, Washington University, St. Louis, MO 63110, USA
| | - Daniel S Ory
- Department of Medicine, Washington University, St. Louis, MO 63110, USA
| | - Jacob Kongsted
- Department of Physics, Chemistry and Pharmacy, DK-5230 Odense M, Denmark
| | - Daniel Wüstner
- Department of Biochemistry and Molecular Biology, DK-5230 Odense M, Denmark.
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45
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Crystallographic Studies of Steroid-Protein Interactions. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1135:27-45. [PMID: 31098809 DOI: 10.1007/978-3-030-14265-0_2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Steroid molecules have a wide range of function in eukaryotes, including the control and maintenance of membranes, hormonal control of transcription, and intracellular signaling. X-ray crystallography has served as a successful tool for gaining understanding of the structural and mechanistic aspects of these functions by providing snapshots of steroids in complex with various types of proteins. These proteins include nuclear receptors activated by steroid hormones, several families of enzymes involved in steroid synthesis and metabolism, and proteins involved in signaling and trafficking pathways. Proteins found in some bacteria that bind and metabolize steroids have been investigated as well. A survey of the steroid-protein complexes that have been studied using crystallography and the insight learned from them is presented.
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46
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Insights into the Molecular Mechanisms of Cholesterol Binding to the NPC1 and NPC2 Proteins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1135:139-160. [PMID: 31098815 DOI: 10.1007/978-3-030-14265-0_8] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
In recent years, a growing number of studies have implicated the coordinated action of NPC1 and NPC2 in intralysosomal transport and efflux of cholesterol. Our current understanding of this process developed with just over two decades of research. Since the cloning of the genes encoding the NPC1 and NPC2 proteins, studies of the biochemical defects observed when either gene is mutated along with computational and structural studies have unraveled key steps in the underlying mechanism. Here, we summarize the major contributions to our understanding of the proposed cholesterol transport controlled by NPC1 and NPC2, and briefly discuss recent findings of cholesterol binding and transport proteins beyond NPC1 and NPC2. We conclude with key questions and major challenges for future research on cholesterol transport by the NPC1 and NPC2 proteins.
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47
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Gao J, Wang JX, Wang XW. MD-2 Homologue Recognizes the White Spot Syndrome Virus Lipid Component and Induces Antiviral Molecule Expression in Shrimp. THE JOURNAL OF IMMUNOLOGY 2019; 203:1131-1141. [PMID: 31331974 DOI: 10.4049/jimmunol.1900268] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 06/22/2019] [Indexed: 12/29/2022]
Abstract
The myeloid differentiation factor 2 (MD-2)-related lipid-recognition (ML) domain is found in multiple proteins, including MD-2, MD-1, Niemann-Pick disease type C2, and mite major allergen proteins. The significance of ML proteins in antibacterial signal transduction and in lipid metabolism has been well studied. However, their function in host-virus interaction remains poorly understood. In the current study, we found that the ML protein family is involved in resistance against white spot syndrome virus in kuruma shrimp, Marsupenaeus japonicus One member, which showed a high similarity to mammalian MD-2/MD-1 and was designated as ML1, participated in the antiviral response by recognizing cholesta-3,5-diene (CD), a lipid component of the white spot syndrome virus envelope. After recognizing CD, ML1 induced the translocation of Rel family NF-κB transcription factor Dorsal into the nucleus, resulting in the expression of Vago, an IFN-like antiviral cytokine in arthropods. Overall, this study revealed the significance of an MD-2 homologue as an immune recognition protein for virus lipids. The identification and characterization of CD-ML1-Dorsal-Vago signaling provided new insights into invertebrate antiviral immunity.
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Affiliation(s)
- Jie Gao
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, Shandong 266237, China
| | - Jin-Xing Wang
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, Shandong 266237, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong 266237, China; and.,State Key Laboratory of Microbial Technology, Shandong University, Qingdao, Shandong 266237, China
| | - Xian-Wei Wang
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, Shandong 266237, China; .,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong 266237, China; and.,State Key Laboratory of Microbial Technology, Shandong University, Qingdao, Shandong 266237, China
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48
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The characteristics and biological significance of NPC2: Mutation and disease. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2019; 782:108284. [PMID: 31843136 DOI: 10.1016/j.mrrev.2019.108284] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 05/10/2019] [Accepted: 07/05/2019] [Indexed: 12/12/2022]
Abstract
Niemann-Pick C disease (NPC) is a rare autosomal recessive disorder characterized by severe neurodegeneration of central nervous system. Linkage studies in multiplex NPC families and genetic complementation research revealed two disease genes, NPC1 and NPC2, both of which are important transporters for cholesterol trafficking. NPC2 executes cholesterol-transport function through protein-protein interaction with NPC1 as well as through protein-membrane interaction directly with membrane of late endosome and lysosome. In addition, NPC2 may play many other roles as indicated by its widely expressing pattern in different cells and presenting in numerous secretory fluids, although it biological significance is less studied today. About 50 clinical cases have been reported documenting over twenty different mutations of NPC2 in NPC patients so far. In this review, we will mainly summarize the molecular characteristics and biological significance of NPC2, highlighting its vital roles in NPC disease.
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49
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Hambleton EA, Jones VAS, Maegele I, Kvaskoff D, Sachsenheimer T, Guse A. Sterol transfer by atypical cholesterol-binding NPC2 proteins in coral-algal symbiosis. eLife 2019; 8:43923. [PMID: 31159921 PMCID: PMC6548501 DOI: 10.7554/elife.43923] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 05/06/2019] [Indexed: 12/29/2022] Open
Abstract
Reef-building corals depend on intracellular dinoflagellate symbionts that provide nutrients. Besides sugars, the transfer of sterols is essential for corals and other sterol-auxotrophic cnidarians. Sterols are important cell components, and variants of the conserved Niemann-Pick Type C2 (NPC2) sterol transporter are vastly up-regulated in symbiotic cnidarians. Types and proportions of transferred sterols and the mechanism of their transfer, however, remain unknown. Using different pairings of symbiont strains with lines of Aiptasia anemones or Acropora corals, we observe both symbiont- and host-driven patterns of sterol transfer, revealing plasticity of sterol use and functional substitution. We propose that sterol transfer is mediated by the symbiosis-specific, non-canonical NPC2 proteins, which gradually accumulate in the symbiosome. Our data suggest that non-canonical NPCs are adapted to the symbiosome environment, including low pH, and play an important role in allowing corals to dominate nutrient-poor shallow tropical seas worldwide. Coral reefs are the most biodiverse marine ecosystems on our planet. Their immense productivity is driven by friendly relationships, or symbioses, between microbes called algae and the corals. Related organisms, such as anemones, also rely on these close associations. The algae use energy from sunlight to make sugars, cholesterol and other molecules that they supply to their host. In exchange, the host’s cells provide homes for the algae inside specialist, acidic structures called symbiosomes. Corals and anemones particularly need cholesterol and other ‘sterol’ molecules from the algae, because they are unable to create these building blocks themselves. In mammals, a protein known as Niemann-Pick Type C2 (NPC2) transports cholesterol out of storage structures into the main body of the cell. Corals and anemones have many different, ‘atypical’ NPC2 proteins: some are produced more during symbiosis, and these are mainly found in symbiosomes. However, it was not known what role these NPC2 proteins play during symbioses. Here, Hambleton et al. studied the symbioses that the anemone Aiptasia and the coral Acropora create with different strains of Symbiodiniaceae algae. The experiments found that the strain of algae dictated the mixture of sterols inside their hosts. The hosts could flexibly use different mixes of sterols and even replace cholesterol with other types of sterols produced by the algae. Atypical NPC2 proteins accumulated over time within the symbiosome and directly bound to cholesterol and various sterols the way other NPC2 proteins normally do. Further experiments suggest that, compared to other NPC2s, atypical NPC2 proteins may be better adapted to the acidic conditions in the symbiosome. Taken together, Hambleton et al. propose that atypical NPC2 proteins may play an important role in allowing corals to thrive in environments poor in nutrients. The first coral reefs emerged over 200 million years ago, when the Earth still only had one continent. Having built-in algae that provide the organisms with nutrients is thought to be the main driver for the formation of coral reefs and the explosion of diversity in coral species. Yet these ancient relationships are now under threat all around the world: environmental stress is causing the algae to be expelled from the corals, leading to the reefs ‘bleaching’ and starving. The more is known about the details of the symbiosis, the more we can understand how corals have evolved, and how we could help them survive the crisis that they are currently facing.
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Affiliation(s)
| | | | - Ira Maegele
- Centre for Organismal Studies (COS), Universität Heidelberg, Heidelberg, Germany
| | - David Kvaskoff
- Heidelberg University Biochemistry Center (BZH), Universität Heidelberg, Heidelberg, Germany
| | - Timo Sachsenheimer
- Heidelberg University Biochemistry Center (BZH), Universität Heidelberg, Heidelberg, Germany
| | - Annika Guse
- Centre for Organismal Studies (COS), Universität Heidelberg, Heidelberg, Germany
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Pfeffer SR. NPC intracellular cholesterol transporter 1 (NPC1)-mediated cholesterol export from lysosomes. J Biol Chem 2019; 294:1706-1709. [PMID: 30710017 DOI: 10.1074/jbc.tm118.004165] [Citation(s) in RCA: 136] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Low-density lipoprotein particles are taken up by cells and delivered to the lysosome where their cholesterol esters are cleaved off by acid lipase. The released, free cholesterol is then exported from lysosomes for cellular needs or storage. This article summarizes recent advances in our understanding of the molecular basis of cholesterol export from lysosomes. Cholesterol export requires NPC intracellular cholesterol transporter 1 (NPC1) and NPC2, genetic mutations of which can cause Niemann-Pick type C disease, a disorder characterized by massive lysosomal accumulation of cholesterol and glycosphingolipids. Analysis of the NPC1 and NPC2 structures and biochemical properties, together with new structures of the related Patched (PTCH) protein, provides new clues to the mechanisms by which NPC proteins may function.
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Affiliation(s)
- Suzanne R Pfeffer
- Department of Biochemistry, Stanford University School of Medicine, Stanford, California 94305-5307.
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