A zinc transporter, transmembrane protein 163 (TMEM163), is critical for the biogenesis of platelet dense granules

Lysosome-related organelles (LROs) are a category of secretory organelles enriched with ions such as Ca2+, which are maintained by ion transporters or channels. Homeostasis of these ions is important for LRO biogenesis and secretion. Hermansky-Pudlak syndrome (HPS) is a recessive disorder with defects in multiple LROs, typically platelet dense granules (DGs) and melanosomes. However, the underlying mechanism of DG deficiency is largely unknown. Using quantitative proteomics, we identified a previously unreported platelet Zn2+ transporter TMEM163, which was significantly reduced in BLOC-1 (Dtnbp1 sdy and Pldn pa), BLOC-2 (Hps6 ru) or AP-3 (Ap3b1 pe) deficient mice and HPS patients (HPS2, 3, 5, 6, or 9). We observed similar platelet DG defects and abnormal intracellular zinc accumulation in platelets of mice deficient in either TMEM163 or dysbindin (a BLOC-1 subunit). In addition, we discovered that BLOC-1 was required for the trafficking of TMEM163 to perinuclear DG and late endosome (LE) marker-positive compartments (likely DG precursors) in MEG-01 cells. Our results suggest that TMEM163 is critical for DG biogenesis and BLOC-1 is required for the trafficking of TMEM163 to putative DG precursors. These new findings suggest that loss of TMEM163 function results in disruption of intracellular zinc homeostasis, and provide insights into the pathogenesis of HPS or platelet storage pool deficiency.

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The pink gene encodes the Drosophila orthologue of the human Hermansky–Pudlak syndrome 5 (HPS5) gene

Genome ◽

10.1139/g07-032 ◽

2007 ◽

Vol 50 (6) ◽

pp. 548-556 ◽

Cited By ~ 18

Author(s):

Monika Syrzycka ◽

Lori A. McEachern ◽

Jennifer Kinneard ◽

Kristel Prabhu ◽

Kathleen Fitzpatrick ◽

...

Keyword(s):

Protein Trafficking ◽

Protein Complexes ◽

Model Organism ◽

Autosomal Recessive Disorders ◽

Dense Granules ◽

Eye Colour ◽

Hermansky Pudlak Syndrome ◽

Lysosome Related Organelles ◽

Key Participants

Hermansky–Pudlak syndrome (HPS) consists of a set of human autosomal recessive disorders, with symptoms resulting from defects in genes required for protein trafficking in lysosome-related organelles such as melanosomes and platelet dense granules. A number of human HPS genes and rodent orthologues have been identified whose protein products are key components of 1 of 4 different protein complexes (AP-3 or BLOC-1, -2, and -3) that are key participants in the process. Drosophila melanogaster has been a key model organism in demonstrating the in vivo significance of many genes involved in protein trafficking pathways; for example, mutations in the “granule group” genes lead to changes in eye colour arising from improper protein trafficking to pigment granules in the developing eye. An examination of the chromosomal positioning of Drosophila HPS gene orthologues suggested that CG9770, the Drosophila HPS5 orthologue, might correspond to the pink locus. Here we confirm this gene assignment, making pink the first eye colour gene in flies to be identified as a BLOC complex gene.

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Platelet storage pool deficiency associated with inherited abnormalities of the inner ear in the mouse pigment mutants muted and mocha

Blood ◽

10.1182/blood.v78.8.2036.2036 ◽

1991 ◽

Vol 78 (8) ◽

pp. 2036-2044 ◽

Cited By ~ 40

Author(s):

RT Swank ◽

M Reddington ◽

O Howlett ◽

EK Novak

Keyword(s):

Inner Ear ◽

Lysosomal Enzyme ◽

Enzyme Secretion ◽

Proximal Tubule Cells ◽

Dense Granules ◽

Storage Pool ◽

Platelet Storage ◽

Whole Mount ◽

Hermansky Pudlak Syndrome ◽

Tubule Cells

Abstract Several inherited human syndromes have combined platelet, auditory, and/or pigment abnormalities. In the mouse the pallid pigment mutant has abnormalities of the otoliths of the inner ear together with a bleeding abnormality caused by platelet storage pool deficiency (SPD). To determine if this association is common, two other mouse pigment mutants, muted and mocha, which are known to have inner ear abnormalities, were examined for hematologic abnormalities. Both mutants had prolonged bleeding times accompanied by abnormalities of dense granules as determined by whole mount electron microscopy of platelets and by labeling platelets with mepacrine. When mutant platelets were treated with collagen, there was minimal secretion of adenosine triphosphate and aggregation was reduced. Lysosomal enzyme secretion in response to thrombin treatment was partially reduced in muted platelets and markedly reduced in mocha platelets. Similar reductions in constitutive lysosomal enzyme secretion from kidney proximal tubule cells were noted in the two mutants. These studies show that several mutations that cause pigment dilution and platelet SPD are associated with abnormalities of the inner ear. Also, these mutants, like previously described mouse pigment mutants, are models for human Hermansky-Pudlak syndrome and provide additional examples of single genes that simultaneously affect melanosomes, lysosomes, and platelet dense granules.

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SLC35D3 delivery from megakaryocyte early endosomes is required for platelet dense granule biogenesis and is differentially defective in Hermansky-Pudlak syndrome models

Blood ◽

10.1182/blood-2011-11-389551 ◽

2012 ◽

Vol 120 (2) ◽

pp. 404-414 ◽

Cited By ~ 34

Author(s):

Ronghua Meng ◽

Yuhuan Wang ◽

Yu Yao ◽

Zhe Zhang ◽

Dawn C. Harper ◽

...

Keyword(s):

Platelet Activation ◽

Subcellular Fractionation ◽

Dense Granule ◽

Direct Role ◽

Excessive Bleeding ◽

Dense Granules ◽

Early Endosomes ◽

Hermansky Pudlak Syndrome ◽

Endosomal Transport ◽

Lysosome Related Organelles

Abstract Platelet dense granules are members of a family of tissue-specific, lysosome-related organelles that also includes melanosomes in melanocytes. Contents released from dense granules after platelet activation promote coagulation and hemostasis, and dense granule defects such as those seen in Hermansky-Pudlak syndrome (HPS) cause excessive bleeding, but little is known about how dense granules form in megakaryocytes (MKs). In the present study, we used SLC35D3, mutation of which causes a dense granule defect in mice, to show that early endosomes play a direct role in dense granule biogenesis. We show that SLC35D3 expression is up-regulated during mouse MK differentiation and is enriched in platelets. Using immunofluorescence and immunoelectron microscopy and subcellular fractionation in megakaryocytoid cells, we show that epitope-tagged and endogenous SLC35D3 localize predominantly to early endosomes but not to dense granule precursors. Nevertheless, SLC35D3 is depleted in mouse platelets from 2 of 3 HPS models and, when expressed ectopically in melanocytes, SLC35D3 localizes to melanosomes in a manner requiring a HPS-associated protein complex that functions from early endosomal transport intermediates. We conclude that SLC35D3 is either delivered to nascent dense granules from contiguous early endosomes as MKs mature or functions in dense granule biogenesis directly from early endosomes, suggesting that dense granules originate from early endosomes in MKs.

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Sandy: a new mouse model for platelet storage pool deficiency

Genetics Research ◽

10.1017/s0016672300029608 ◽

1991 ◽

Vol 58 (1) ◽

pp. 51-62 ◽

Cited By ~ 50

Author(s):

Richard T. Swank ◽

Hope O. Sweet ◽

Muriel T. Davisson ◽

Madonna Reddington ◽

Edward K. Novak

Keyword(s):

Dense Granule ◽

Recessive Mutation ◽

Mouse Mutant ◽

Dense Granules ◽

Storage Pool ◽

Platelet Storage ◽

Autosomal Recessive Mutation ◽

Acidification Activity ◽

Hermansky Pudlak Syndrome ◽

Reduced Rate

SummarySandy (sdy) is a mouse mutant with diluted pigmentation which recently arose in the DBA/2J strain. Genetic tests indicate it is caused by an autosomal recessive mutation on mouse Chromosome 13 near thecrandXtgenetic loci. This mutation is different genetically and hematologically from previously described mouse pigment mutations with storage pool deficiency (SPD). The sandy mutant has diluted pigmentation in both eyes and fur, is fully viable and has prolonged bleeding times. Platelet serotonin levels are extremely low although ATP dependent acidification activity of platelet organelles appears normal. Also, platelet dense granules are extremely reduced in number when analysed by electron microscopy of unfixed platelets. Platelets have abnormal uptake and flashing of the fluorescent dye mepacrine. Secretion of lysosomal enzymes from kidney and from thrombin-stimulated platelets is depressed 2- and 3-fold, and ceroid pigment is present in kidney. Sandy platelets have a reduced rate of aggregation induced by collagen. The sandy mutant has an unusually severe dense granule defect and thus may be an appropriate model for cases of human Hermansky-Pudlak syndrome with similarly extreme types of SPD. It represents the tenth example of a mouse mutant with simultaneous defects in melanosomes, lysosomes and/or platelet dense granules.

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Platelet storage pool deficiency associated with inherited abnormalities of the inner ear in the mouse pigment mutants muted and mocha

Blood ◽

10.1182/blood.v78.8.2036.bloodjournal7882036 ◽

1991 ◽

Vol 78 (8) ◽

pp. 2036-2044 ◽

Cited By ~ 1

Author(s):

RT Swank ◽

M Reddington ◽

O Howlett ◽

EK Novak

Keyword(s):

Inner Ear ◽

Lysosomal Enzyme ◽

Enzyme Secretion ◽

Proximal Tubule Cells ◽

Dense Granules ◽

Storage Pool ◽

Platelet Storage ◽

Whole Mount ◽

Hermansky Pudlak Syndrome ◽

Tubule Cells

Several inherited human syndromes have combined platelet, auditory, and/or pigment abnormalities. In the mouse the pallid pigment mutant has abnormalities of the otoliths of the inner ear together with a bleeding abnormality caused by platelet storage pool deficiency (SPD). To determine if this association is common, two other mouse pigment mutants, muted and mocha, which are known to have inner ear abnormalities, were examined for hematologic abnormalities. Both mutants had prolonged bleeding times accompanied by abnormalities of dense granules as determined by whole mount electron microscopy of platelets and by labeling platelets with mepacrine. When mutant platelets were treated with collagen, there was minimal secretion of adenosine triphosphate and aggregation was reduced. Lysosomal enzyme secretion in response to thrombin treatment was partially reduced in muted platelets and markedly reduced in mocha platelets. Similar reductions in constitutive lysosomal enzyme secretion from kidney proximal tubule cells were noted in the two mutants. These studies show that several mutations that cause pigment dilution and platelet SPD are associated with abnormalities of the inner ear. Also, these mutants, like previously described mouse pigment mutants, are models for human Hermansky-Pudlak syndrome and provide additional examples of single genes that simultaneously affect melanosomes, lysosomes, and platelet dense granules.

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A New Gene Which Regulates Platelet Dense Granules.

Blood ◽

10.1182/blood.v106.11.2177.2177 ◽

2005 ◽

Vol 106 (11) ◽

pp. 2177-2177

Author(s):

Rashi Gautam ◽

Michael E. Rusiniak ◽

Sreenivasulu Chintala ◽

Jian Tan ◽

Wei Li ◽

...

Keyword(s):

Coat Color ◽

Single Gene ◽

Backcross Progeny ◽

Genomic Region ◽

Dense Granule ◽

Dense Granules ◽

Prolonged Bleeding ◽

Platelet Storage ◽

New Gene ◽

Lysosome Related Organelles

Abstract Hermansky-Pudlak Syndrome (HPS) is a genetically heterogeneous disease characterized by defects in trafficking of intracellular vesicles to lysosome-related organelles such as melanosomes, lung lamellar bodies and platelet dense granules. The ashen (rab27a) mouse coat color mutant maintained at Roswell Park Cancer Institute (ash-Roswell) has been proposed as an animal model of HPS based upon prolonged bleeding times, decreased platelet aggregation and greatly decreased platelet dense granule components, including serotonin and ADP. However, human patients with Rab27a deficiency (Griscelli Syndrome) and other isolates of mouse ashen mutants do not exhibit prolonged bleeding suggesting an additional mutation in a gene affecting platelets but not melanocytes in the ash-Roswell mouse. In order to identify this mutation, a backcross between ash-Roswell and the PWK control strain was analyzed. In 390 backcross progeny, deficient platelet serotonin and diluted coat color (Rab27a) phenotypes segregated independently and in the proportions expected for single gene traits. The gene for serotonin deficiency was narrowed to a 2.1Mb region of mouse chromosome 10 containing 15 genes. None of these genes have been implicated previously in platelet storage pool deficiency. These studies indicate this genomic region contains a gene which uniquely controls platelet dense granules and is a candidate gene for a new form of human HPS.

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Alterations in ZnT1 expression and function lead to impaired intracellular zinc homeostasis in cancer

Cell Death Discovery ◽

10.1038/s41420-019-0224-0 ◽

2019 ◽

Vol 5 (1) ◽

Cited By ~ 2

Author(s):

Adrian Israel Lehvy ◽

Guy Horev ◽

Yarden Golan ◽

Fabian Glaser ◽

Yael Shammai ◽

...

Keyword(s):

Malignant Tumors ◽

Zinc Homeostasis ◽

Healthy Population ◽

Missense Mutations ◽

Protein Alignment ◽

Loss Of Function ◽

Intracellular Zinc ◽

Dismal Prognosis ◽

Zinc Levels ◽

And Function

Abstract Zinc is vital for the structure and function of ~3000 human proteins and hence plays key physiological roles. Consequently, impaired zinc homeostasis is associated with various human diseases including cancer. Intracellular zinc levels are tightly regulated by two families of zinc transporters: ZIPs and ZnTs; ZIPs import zinc into the cytosol from the extracellular milieu, or from the lumen of organelles into the cytoplasm. In contrast, the vast majority of ZnTs compartmentalize zinc within organelles, whereas the ubiquitously expressed ZnT1 is the sole zinc exporter. Herein, we explored the hypothesis that qualitative and quantitative alterations in ZnT1 activity impair cellular zinc homeostasis in cancer. Towards this end, we first used bioinformatics to analyze inactivating mutations in ZIPs and ZNTs, catalogued in the COSMIC and gnomAD databases, representing tumor specimens and healthy population controls, respectively. ZnT1, ZnT10, ZIP8, and ZIP10 showed extremely high rates of loss of function mutations in cancer as compared to healthy controls. Analysis of the putative functional impact of missense mutations in ZnT1-ZnT10 and ZIP1-ZIP14, using homologous protein alignment and structural predictions, revealed that ZnT1 displays a markedly increased frequency of predicted functionally deleterious mutations in malignant tumors, as compared to a healthy population. Furthermore, examination of ZnT1 expression in 30 cancer types in the TCGA database revealed five tumor types with significant ZnT1 overexpression, which predicted dismal prognosis for cancer patient survival. Novel functional zinc transport assays, which allowed for the indirect measurement of cytosolic zinc levels, established that wild type ZnT1 overexpression results in low intracellular zinc levels. In contrast, overexpression of predicted deleterious ZnT1 missense mutations did not reduce intracellular zinc levels, validating eight missense mutations as loss of function (LoF) mutations. Thus, alterations in ZnT1 expression and LoF mutations in ZnT1 provide a molecular mechanism for impaired zinc homeostasis in cancer formation and/or progression.

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Altered Expression of Peroxiredoxins in Mouse Model of Progressive Myoclonus Epilepsy upon LPS-Induced Neuroinflammation

Antioxidants ◽

10.3390/antiox10030357 ◽

2021 ◽

Vol 10 (3) ◽

pp. 357

Author(s):

Mojca Trstenjak Prebanda ◽

Petra Matjan-Štefin ◽

Boris Turk ◽

Nataša Kopitar-Jerala

Keyword(s):

Mouse Model ◽

Redox Homeostasis ◽

Underlying Mechanism ◽

Loss Of Function ◽

Altered Expression ◽

Lps Challenge ◽

Progressive Myoclonus Epilepsy ◽

Myoclonus Epilepsy ◽

The Brain ◽

Deficient Mice

Stefin B (cystatin B) is an inhibitor of endo-lysosomal cysteine cathepsin, and the loss-of-function mutations in the stefin B gene were reported in patients with Unverricht–Lundborg disease (EPM1), a form of progressive myoclonus epilepsy. Stefin B-deficient mice, a mouse model of the disease, display key features of EPM1, including myoclonic seizures. Although the underlying mechanism is not yet completely clear, it was reported that the impaired redox homeostasis and inflammation in the brain contribute to the progression of the disease. In the present study, we investigated if lipopolysaccharide (LPS)-triggered neuroinflammation affected the protein levels of redox-sensitive proteins: thioredoxin (Trx1), thioredoxin reductase (TrxR), peroxiredoxins (Prxs) in brain and cerebella of stefin B-deficient mice. LPS challenge was found to result in a marked elevation of Trx1 and TrxR in the brain and cerebella of stefin B deficient mice, while Prx1 was upregulated only in cerebella after LPS challenge. Mitochondrial peroxiredoxin 3 (Prx3), was upregulated also in the cerebellar tissue lysates prepared from unchallenged stefin B deficient mice, while after LPS challenge Prx3 was upregulated in stefin B deficient brain and cerebella. Our results imply the role of oxidative stress in the progression of the disease.

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Impaired platelet responses to thrombin and collagen in AKT-1–deficient mice

Blood ◽

10.1182/blood-2003-10-3428 ◽

2004 ◽

Vol 104 (6) ◽

pp. 1703-1710 ◽

Cited By ~ 167

Author(s):

Juhua Chen ◽

Sarmishtha De ◽

Derek S. Damron ◽

William S. Chen ◽

Nissim Hay ◽

...

Keyword(s):

Platelet Aggregation ◽

Ex Vivo ◽

Dense Granules ◽

Fibrinogen Binding ◽

Downstream Effectors ◽

Low Concentrations ◽

Phosphoinositide 3 Kinase ◽

Deficient Mice ◽

Granule Release

Abstract We investigated the role of Akt-1, one of the major downstream effectors of phosphoinositide 3-kinase (PI3K), in platelet function using mice in which the gene for Akt-1 had been inactivated. Using ex vivo techniques, we showed that Akt-1-deficient mice exhibited impaired platelet aggregation and spreading in response to various agonists. These differences were most apparent in platelets activated with low concentrations of thrombin. Although Akt-1 is not the predominant Akt isoform in mouse platelets, its absence diminished the amount of total phospho-Akt and inhibited increases in intracellular Ca2+ concentration in response to thrombin. Moreover, thrombin-induced platelet α-granule release as well as release of adenosine triphosphate from dense granules was also defective in Akt-1-null platelets. Although the absence of Akt-1 did not influence expression of the major platelet receptors for thrombin and collagen, fibrinogen binding in response to these agonists was significantly reduced. As a consequence of impaired αIIbβ3 activation and platelet aggregation, Akt-1 null mice showed significantly longer bleeding times than wild-type mice. (Blood. 2004;104:1703-1710)

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Perinatal Hypercholesterolemia Exacerbates Atherosclerosis Lesions in Offspring by Altering Metabolism of Trimethylamine-N-Oxide and Bile Acids

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvbaha.117.309923 ◽

2017 ◽

Vol 37 (11) ◽

pp. 2053-2063 ◽

Cited By ~ 21

Author(s):

Charlotte Trenteseaux ◽

Anh-thu Gaston ◽

Audrey Aguesse ◽

Guillaume Poupeau ◽

Pierre de Coppet ◽

...

Keyword(s):

Gene Expression ◽

Apolipoprotein E ◽

Bile Acids ◽

Experimental Studies ◽

Underlying Mechanism ◽

Female Offspring ◽

Promoter Regions ◽

Maternal Hypercholesterolemia ◽

Atherosclerosis Development ◽

Deficient Mice

Objective— Experimental studies suggest that maternal hypercholesterolemia may be relevant for the early onset of cardiovascular disease in offspring. We investigated the effect of perinatal hypercholesterolemia on the atherosclerosis development in the offspring of apolipoprotein E–deficient mice and the underlying mechanism. Approach and Results— Atherosclerosis and related parameters were studied in adult male or female apolipoprotein E–deficient mice offspring from either normocholesterolemic or hypercholesterolemic mothers and normocholesterolemic fathers. Female born to hypercholesterolemic mothers had more aortic root lesions than female born to normocholesterolemic mothers. Lesions in whole aorta did not differ between groups. Higher trimethylamine-N-oxide levels and Fmo3 hepatic gene expression were higher in female born to hypercholesterolemic mothers offspring compared with female born to normocholesterolemic mothers and male. Trimethylamine-N-oxide levels were correlated with the size of atherosclerotic root lesions. Levels of hepatic cholesterol and gallbladder bile acid were greater in male born to hypercholesterolemic mothers compared with male born to normocholesterolemic mothers. At 18 weeks of age, female born to hypercholesterolemic mothers showed lower hepatic Scarb1 and Cyp7a1 but higher Nr1h4 gene expression compared with female born to normocholesterolemic mothers. Male born to hypercholesterolemic mothers showed an increase in Scarb1 and Ldlr gene expression compared with male born to normocholesterolemic mothers. At 25 weeks of age, female born to hypercholesterolemic mothers had lower Cyp7a1 gene expression compared with female born to normocholesterolemic mothers. DNA methylation of Fmo3, Scarb1 , and Ldlr promoter regions was slightly modified and may explain the mRNA expression modulation. Conclusions— Our findings suggest that maternal hypercholesterolemia may exacerbate the development of atherosclerosis in female offspring by affecting metabolism of trimethylamine-N-oxide and bile acids. These data could be explained by epigenetic alterations.

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