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Bouhafs N, N'joumi C, Elouali A, Babakhouya A, Rkain M, Benajiba N. Albinism and Primary Immunodeficiency in Infants: A Case Study of Griscelli Syndrome. Cureus 2024; 16:e62178. [PMID: 38993473 PMCID: PMC11239126 DOI: 10.7759/cureus.62178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/11/2024] [Indexed: 07/13/2024] Open
Abstract
Griscelli syndrome (GS) type II is a rare hereditary disorder characterized by partial albinism, immunodeficiency, and the subsequent development of hemophagocytic syndrome (HPS). Herein, we present a case involving a four-month-old infant admitted to our facility due to a prolonged fever complicated by HPS. The diagnosis of GS type 2 was established based on a constellation of clinical and laboratory findings: consanguinity, familial history of early infectious fatalities, ocular-cutaneous hypopigmentation, characteristic silvery hair sheen, onset of HPS, and notably, the pathognomonic appearance upon microscopic examination of a hair sample. The absence of giant granules within nucleated cells helped exclude Chediak-Higashi syndrome.
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Affiliation(s)
- Nadia Bouhafs
- Department of Pediatrics, Centre Hospitalier Universitaire Mohammed VI Oujda, Oujda, MAR
| | - Chaimae N'joumi
- Department of Pediatrics, Centre Hospitalier Universitaire Mohammed VI Oujda, Oujda, MAR
| | - Aziza Elouali
- Department of Pediatrics, Faculty of Medicine and Pharmacy of Oujda, Mohammed I University, Oujda, MAR
| | - Abdeladim Babakhouya
- Department of Pediatrics, Centre Hospitalier Universitaire Mohammed VI Oujda, Oujda, MAR
- Department of Pediatrics, Faculty of Medicine and Pharmacy of Oujda, Mohammed I University, Oujda, MAR
| | - Maria Rkain
- Department of Pediatrics, Faculty of Medicine and Pharmacy of Oujda, Mohammed I University, Oujda, MAR
- Department of Pediatric Gastroenterology, Centre Hospitalier Universitaire Mohammed VI Oujda, Oujda, MAR
| | - Noufissa Benajiba
- Department of Pediatric Hematology, Centre Hospitalier Universitaire Mohammed VI Oujda, Oujda, MAR
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Salah HT, Yang RK, Roy-Chowdhuri S, Ross MI, Aung PP, Rothrock AT, Torres-Cabala CA, Curry JL, Prieto VG, Nagarajan P, Cho WC. Spitz melanocytic neoplasms with MLPH::ALK fusions: Report of two cases with previously unreported features and literature review. J Cutan Pathol 2024; 51:407-414. [PMID: 38444194 DOI: 10.1111/cup.14605] [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: 07/26/2023] [Revised: 01/08/2024] [Accepted: 02/20/2024] [Indexed: 03/07/2024]
Abstract
ALK-fused Spitz melanocytic neoplasms are a distinct subgroup of melanocytic lesions exhibiting unique histopathologic characteristics. These lesions often manifest as exophytic or polypoid tumors, characterized by fusiform-to-epithelioid melanocytes arranged in a nested, fascicular, or plexiform growth pattern. Several fusion partners of the ALK gene have been identified in spitzoid melanocytic neoplasms, with TPM3 and DCTN1 being the most prevalent. Less common fusion partners include NPM1, TPR, CLIP1, GTF3C2, EEF2, MYO5A, KANK1, and EHBP1. The MLPH gene, which encodes melanophilin (MLPH), playing a crucial role in regulating skin pigmentation by acting as a linker between RAB27A and myosin Va during melanosome transport, has also recently been recognized as a rare fusion partner of ALK in Spitz melanocytic neoplasms. Currently, there exists a sparse documentation within English literature, illustrating a limited number of cases featuring MLPH::ALK fusion in Spitz melanocytic neoplasms. In this report, we present two additional cases, including a previously unreported instance of Spitz melanoma, contributing to the expanding knowledge on ALK-fused Spitz melanocytic neoplasms. In addition, we provide a comprehensive review of the clinical, histopathologic, and molecular features observed in documented cases with this novel fusion.
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Affiliation(s)
- Haneen T Salah
- Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Houston, Texas, USA
| | - Richard K Yang
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Sinchita Roy-Chowdhuri
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Merrick I Ross
- Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Phyu P Aung
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Aimi T Rothrock
- Department of Pathology, Albany Medical Center, Albany, New York, USA
| | - Carlos A Torres-Cabala
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Jonathan L Curry
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Victor G Prieto
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Priyadharsini Nagarajan
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Woo Cheal Cho
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
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Carew JA, Cristofaro V, Goyal RK, Sullivan MP. Differential Myosin 5a splice variants in innervation of pelvic organs. Front Physiol 2023; 14:1304537. [PMID: 38148903 PMCID: PMC10749955 DOI: 10.3389/fphys.2023.1304537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 11/20/2023] [Indexed: 12/28/2023] Open
Abstract
Introduction: Myosin proteins interact with filamentous actin and translate the chemical energy generated by ATP hydrolysis into a wide variety of mechanical functions in all cell types. The classic function of conventional myosins is mediation of muscle contraction, but myosins also participate in processes as diverse as exocytosis/endocytosis, membrane remodeling, and cytokinesis. Myosin 5a (Myo5a) is an unconventional motor protein well-suited to the processive transport of diverse molecular cargo within cells and interactions with multiprotein membrane complexes that facilitate exocytosis. Myo5a includes a region consisting of six small alternative exons which can undergo differential splicing. Neurons and skin melanocytes express characteristic splice variants of Myo5a, which are specialized for transport processes unique to those cell types. But less is known about the expression of Myo5a splice variants in other tissues, their cargos and interactive partners, and their regulation. Methods: In visceral organs, neurotransmission-induced contraction or relaxation of smooth muscle is mediated by Myo5a. Axons within urogenital organs and distal colon of rodents arise from cell bodies located in the major pelvic ganglion (MPG). However, in contrast to urogenital organs, the distal colon also contains soma of the enteric nervous system. Therefore, the rodent pelvic organs provide an opportunity to compare the expression of Myo5a splice variants, not only in different tissues innervated by the pelvic nerves, but also in different subcellular compartments of those nerves. This study examines the expression and distribution of Myo5a splice variants in the MPG, compared to the bladder, corpus cavernosum of the penis (CCP) and distal colon using immunohistochemistry and mRNA analyses. Results/discussion: We report detection of characteristic Myo5a variants in these tissues, with bladder and CCP displaying a similar variant pattern but one which differed from that of distal colon. In all three organs, Myo5a variants were distinct compared to the MPG, implying segregation of one variant within nerve soma and its exclusion from axons. The expression of distinct Myo5a variant arrays is likely to be adaptive, and to underlie specific functions fulfilled by Myo5a in those particular locations.
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Affiliation(s)
- Josephine A. Carew
- Urology Research, VA Boston Healthcare System, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
- Department of Medicine, Brigham and Women’s Hospital, Boston, MA, United States
| | - Vivian Cristofaro
- Urology Research, VA Boston Healthcare System, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
- Department of Surgery, Brigham and Women’s Hospital, Boston, MA, United States
| | - Raj K. Goyal
- Urology Research, VA Boston Healthcare System, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
| | - Maryrose P. Sullivan
- Urology Research, VA Boston Healthcare System, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
- Department of Surgery, Brigham and Women’s Hospital, Boston, MA, United States
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Tobler R, Souilmi Y, Huber CD, Bean N, Turney CSM, Grey ST, Cooper A. The role of genetic selection and climatic factors in the dispersal of anatomically modern humans out of Africa. Proc Natl Acad Sci U S A 2023; 120:e2213061120. [PMID: 37220274 PMCID: PMC10235988 DOI: 10.1073/pnas.2213061120] [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: 07/29/2022] [Accepted: 03/14/2023] [Indexed: 05/25/2023] Open
Abstract
The evolutionarily recent dispersal of anatomically modern humans (AMH) out of Africa (OoA) and across Eurasia provides a unique opportunity to examine the impacts of genetic selection as humans adapted to multiple new environments. Analysis of ancient Eurasian genomic datasets (~1,000 to 45,000 y old) reveals signatures of strong selection, including at least 57 hard sweeps after the initial AMH movement OoA, which have been obscured in modern populations by extensive admixture during the Holocene. The spatiotemporal patterns of these hard sweeps provide a means to reconstruct early AMH population dispersals OoA. We identify a previously unsuspected extended period of genetic adaptation lasting ~30,000 y, potentially in the Arabian Peninsula area, prior to a major Neandertal genetic introgression and subsequent rapid dispersal across Eurasia as far as Australia. Consistent functional targets of selection initiated during this period, which we term the Arabian Standstill, include loci involved in the regulation of fat storage, neural development, skin physiology, and cilia function. Similar adaptive signatures are also evident in introgressed archaic hominin loci and modern Arctic human groups, and we suggest that this signal represents selection for cold adaptation. Surprisingly, many of the candidate selected loci across these groups appear to directly interact and coordinately regulate biological processes, with a number associated with major modern diseases including the ciliopathies, metabolic syndrome, and neurodegenerative disorders. This expands the potential for ancestral human adaptation to directly impact modern diseases, providing a platform for evolutionary medicine.
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Affiliation(s)
- Raymond Tobler
- Australian Centre for Ancient DNA, The University of Adelaide, Adelaide, SA5005, Australia
| | - Yassine Souilmi
- Australian Centre for Ancient DNA, The University of Adelaide, Adelaide, SA5005, Australia
- Environment Institute, The University of Adelaide, Adelaide, SA5005, Australia
| | - Christian D. Huber
- Australian Centre for Ancient DNA, The University of Adelaide, Adelaide, SA5005, Australia
| | - Nigel Bean
- Australian Research Council Centre of Excellence for Mathematical and Statistical Frontiers, The University of Adelaide, Adelaide, SA5005, Australia
- School of Mathematical Sciences, The University of Adelaide, Adelaide, SA5005, Australia
| | - Chris S. M. Turney
- Division of Research, University of Technology Sydney, Ultimo, NSW2007, Australia
| | - Shane T. Grey
- School of Biotechnology and Biomolecular Sciences, Faculty of Science, University of New South Wales, Sydney, NSW2052, Australia
- Transplantation Immunology Group, Translation Science Pillar, Garvan Institute of Medical Research, Darlinghurst, NSW2010, Australia
| | - Alan Cooper
- Australian Centre for Ancient DNA, The University of Adelaide, Adelaide, SA5005, Australia
- Blue Sky Genetics, Ashton, SA5137, Australia
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Overlapping Machinery in Lysosome-Related Organelle Trafficking: A Lesson from Rare Multisystem Disorders. Cells 2022; 11:cells11223702. [PMID: 36429129 PMCID: PMC9688865 DOI: 10.3390/cells11223702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 11/08/2022] [Accepted: 11/16/2022] [Indexed: 11/23/2022] Open
Abstract
Lysosome-related organelles (LROs) are a group of functionally diverse, cell type-specific compartments. LROs include melanosomes, alpha and dense granules, lytic granules, lamellar bodies and other compartments with distinct morphologies and functions allowing specialised and unique functions of their host cells. The formation, maturation and secretion of specific LROs are compromised in a number of hereditary rare multisystem disorders, including Hermansky-Pudlak syndromes, Griscelli syndrome and the Arthrogryposis, Renal dysfunction and Cholestasis syndrome. Each of these disorders impacts the function of several LROs, resulting in a variety of clinical features affecting systems such as immunity, neurophysiology and pigmentation. This has demonstrated the close relationship between LROs and led to the identification of conserved components required for LRO biogenesis and function. Here, we discuss aspects of this conserved machinery among LROs in relation to the heritable multisystem disorders they associate with, and present our current understanding of how dysfunctions in the proteins affected in the disease impact the formation, motility and ultimate secretion of LROs. Moreover, we have analysed the expression of the members of the CHEVI complex affected in Arthrogryposis, Renal dysfunction and Cholestasis syndrome, in different cell types, by collecting single cell RNA expression data from the human protein atlas. We propose a hypothesis describing how transcriptional regulation could constitute a mechanism that regulates the pleiotropic functions of proteins and their interacting partners in different LROs.
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Babina M, Franke K, Bal G. How "Neuronal" Are Human Skin Mast Cells? Int J Mol Sci 2022; 23:ijms231810871. [PMID: 36142795 PMCID: PMC9505265 DOI: 10.3390/ijms231810871] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 09/05/2022] [Accepted: 09/14/2022] [Indexed: 11/24/2022] Open
Abstract
Mast cells are evolutionarily old cells and the principal effectors in allergic responses and inflammation. They are seeded from the yolk sac during embryogenesis or are derived from hematopoietic progenitors and are therefore related to other leukocyte subsets, even though they form a separate clade in the hematopoietic system. Herein, we systematically bundle information from several recent high-throughput endeavors, especially those comparing MCs with other cell types, and combine such information with knowledge on the genes’ functions to reveal groups of neuronal markers specifically expressed by MCs. We focus on recent advances made regarding human tissue MCs, but also refer to studies in mice. In broad terms, genes hyper-expressed in MCs, but largely inactive in other myelocytes, can be classified into subcategories such as traffic/lysosomes (MLPH and RAB27B), the dopamine system (MAOB, DRD2, SLC6A3, and SLC18A2), Ca2+-related entities (CALB2), adhesion molecules (L1CAM and NTM) and, as an overall principle, the transcription factors and modulators of transcriptional activity (LMO4, PBX1, MEIS2, and EHMT2). Their function in MCs is generally unknown but may tentatively be deduced by comparison with other systems. MCs share functions with the nervous system, as they express typical neurotransmitters (histamine and serotonin) and a degranulation machinery that shares features with the neuronal apparatus at the synapse. Therefore, selective overlaps are plausible, and they further highlight the uniqueness of MCs within the myeloid system, as well as when compared with basophils. Apart from investigating their functional implications in MCs, a key question is whether their expression in the lineage is due to the specific reactivation of genes normally silenced in leukocytes or whether the genes are not switched off during mastocytic development from early progenitors.
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Affiliation(s)
- Magda Babina
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Immunology and Allergology IA, 12203 Berlin, Germany
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Institute of Allergology, Hindenburgdamm 30, 12203 Berlin, Germany
- Correspondence:
| | - Kristin Franke
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Immunology and Allergology IA, 12203 Berlin, Germany
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Institute of Allergology, Hindenburgdamm 30, 12203 Berlin, Germany
| | - Gürkan Bal
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Immunology and Allergology IA, 12203 Berlin, Germany
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, Institute of Allergology, Hindenburgdamm 30, 12203 Berlin, Germany
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Davoudi P, Do DN, Rathgeber B, Colombo SM, Sargolzaei M, Plastow G, Wang Z, Karimi K, Hu G, Valipour S, Miar Y. Genome-wide detection of copy number variation in American mink using whole-genome sequencing. BMC Genomics 2022; 23:649. [PMID: 36096727 PMCID: PMC9468235 DOI: 10.1186/s12864-022-08874-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 09/05/2022] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Copy number variations (CNVs) represent a major source of genetic diversity and contribute to the phenotypic variation of economically important traits in livestock species. In this study, we report the first genome-wide CNV analysis of American mink using whole-genome sequence data from 100 individuals. The analyses were performed by three complementary software programs including CNVpytor, DELLY and Manta. RESULTS A total of 164,733 CNVs (144,517 deletions and 20,216 duplications) were identified representing 5378 CNV regions (CNVR) after merging overlapping CNVs, covering 47.3 Mb (1.9%) of the mink autosomal genome. Gene Ontology and KEGG pathway enrichment analyses of 1391 genes that overlapped CNVR revealed potential role of CNVs in a wide range of biological, molecular and cellular functions, e.g., pathways related to growth (regulation of actin cytoskeleton, and cAMP signaling pathways), behavior (axon guidance, circadian entrainment, and glutamatergic synapse), lipid metabolism (phospholipid binding, sphingolipid metabolism and regulation of lipolysis in adipocytes), and immune response (Wnt signaling, Fc receptor signaling, and GTPase regulator activity pathways). Furthermore, several CNVR-harbored genes associated with fur characteristics and development (MYO5A, RAB27B, FGF12, SLC7A11, EXOC2), and immune system processes (SWAP70, FYN, ORAI1, TRPM2, and FOXO3). CONCLUSIONS This study presents the first genome-wide CNV map of American mink. We identified 5378 CNVR in the mink genome and investigated genes that overlapped with CNVR. The results suggest potential links with mink behaviour as well as their possible impact on fur quality and immune response. Overall, the results provide new resources for mink genome analysis, serving as a guideline for future investigations in which genomic structural variations are present.
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Affiliation(s)
- Pourya Davoudi
- Department of Animal Science and Aquaculture, Dalhousie University, Truro, NS, Canada
| | - Duy Ngoc Do
- Department of Animal Science and Aquaculture, Dalhousie University, Truro, NS, Canada
| | - Bruce Rathgeber
- Department of Animal Science and Aquaculture, Dalhousie University, Truro, NS, Canada
| | - Stefanie M Colombo
- Department of Animal Science and Aquaculture, Dalhousie University, Truro, NS, Canada
| | - Mehdi Sargolzaei
- Department of Pathobiology, University of Guelph, Guelph, ON, Canada
- Select Sires Inc., Plain City, OH, USA
| | - Graham Plastow
- Livestock Gentec, Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada
| | - Zhiquan Wang
- Livestock Gentec, Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada
| | - Karim Karimi
- Department of Animal Science and Aquaculture, Dalhousie University, Truro, NS, Canada
| | - Guoyu Hu
- Department of Animal Science and Aquaculture, Dalhousie University, Truro, NS, Canada
| | - Shafagh Valipour
- Department of Animal Science and Aquaculture, Dalhousie University, Truro, NS, Canada
| | - Younes Miar
- Department of Animal Science and Aquaculture, Dalhousie University, Truro, NS, Canada.
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Ermini L, Francis JC, Rosa GS, Rose AJ, Ning J, Greaves M, Swain A. Evolutionary selection of alleles in the melanophilin gene that impacts on prostate organ function and cancer risk. EVOLUTION MEDICINE AND PUBLIC HEALTH 2021; 9:311-321. [PMID: 34754452 PMCID: PMC8573191 DOI: 10.1093/emph/eoab026] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 09/03/2021] [Indexed: 11/21/2022]
Abstract
Background and objectives Several hundred inherited genetic variants or SNPs that alter the risk of cancer have been identified through genome-wide association studies. In populations of European ancestry, these variants are mostly present at relatively high frequencies. To gain insight into evolutionary origins, we screened a series of genes and SNPs linked to breast or prostate cancer for signatures of historical positive selection. Methodology We took advantage of the availability of the 1000 genome data and we performed genomic scans for positive selection in five different Caucasian populations as well as one African reference population. We then used prostate organoid cultures to provide a possible functional explanation for the interplay between the action of evolutionary forces and the disease risk association. Results Variants in only one gene showed genomic signatures of positive, evolutionary selection within Caucasian populations melanophilin (MLPH). Functional depletion of MLPH in prostate organoids, by CRISPR/Cas9 mutation, impacted lineage commitment of progenitor cells promoting luminal versus basal cell differentiation and on resistance to androgen deprivation. Conclusions and implications The MLPH variants influencing prostate cancer risk may have been historically selected for their adaptive benefit on skin pigmentation but MLPH is highly expressed in the prostate and the derivative, positively selected, alleles decrease the risk of prostate cancer. Our study suggests a potential functional mechanism via which MLPH and its genetic variants could influence risk of prostate cancer, as a serendipitous consequence of prior evolutionary benefits to another tissue. Lay Summary We screened a limited series of genomic variants associated with breast and prostate cancer risk for signatures of historical positive selection. Variants within the melanophilin (MLPH) gene fell into this category. Depletion of MLPH in prostate organoid cultures, suggested a potential functional mechanism for impacting on cancer risk, as a serendipitous consequence of prior evolutionary benefits to another tissue.
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Affiliation(s)
- Luca Ermini
- Centre for Evolution and Cancer, The Institute of Cancer Research, London, UK
| | - Jeffrey C Francis
- Division of Cancer Biology, The Institute of Cancer Research, London, UK
| | - Gabriel S Rosa
- Division of Cancer Biology, The Institute of Cancer Research, London, UK
| | - Alexandra J Rose
- Division of Cancer Biology, The Institute of Cancer Research, London, UK
| | - Jian Ning
- Division of Cancer Biology, The Institute of Cancer Research, London, UK.,Tumour Profiling Unit, The Institute of Cancer Research, London, UK
| | - Mel Greaves
- Centre for Evolution and Cancer, The Institute of Cancer Research, London, UK
| | - Amanda Swain
- Division of Cancer Biology, The Institute of Cancer Research, London, UK.,Tumour Profiling Unit, The Institute of Cancer Research, London, UK
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Christen M, de le Roi M, Jagannathan V, Becker K, Leeb T. MYO5A Frameshift Variant in a Miniature Dachshund with Coat Color Dilution and Neurological Defects Resembling Human Griscelli Syndrome Type 1. Genes (Basel) 2021; 12:genes12101479. [PMID: 34680875 PMCID: PMC8535926 DOI: 10.3390/genes12101479] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 09/10/2021] [Accepted: 09/20/2021] [Indexed: 11/16/2022] Open
Abstract
A 1-month-old, female, smooth-haired miniature Dachshund with dilute color and neurological defects was investigated. The aim of this study was to characterize the clinical signs, histopathological changes and underlying genetic defect. The puppy had visible coat color dilution and was unable to hold its head on its own or to remain in a stable prone position for an extended period. Histopathological examination revealed an accumulation of clumped melanin and deposition of accumulated keratin within the hair follicles, accompanied by dermal pigmentary incontinence. These dermatological changes were compatible with the histopathology described in dogs with an MLPH-related dilute coat color. We sequenced the genome of the affected dog and compared the data to 795 control genomes. MYO5A, coding for myosin VA, was investigated as the top functional candidate gene. This search revealed a private homozygous frameshift variant in MYO5A, XM_022412522.1:c.4973_4974insA, predicted to truncate 269 amino acids (13.8%) of the wild type myosin VA protein, XP_022268230.1:p.(Asn1658Lysfs*28). The genotypes of the index family showed the expected co-segregation with the phenotype and the mutant allele was absent from 142 additionally genotyped, unrelated Dachshund dogs. MYO5A loss of function variants cause Griscelli type 1 syndrome in humans, lavender foal in horses and the phenotype of the dilute mouse mutant. Based on the available data, together with current knowledge on other species, we propose the identified MYO5A frameshift insertion as a candidate causative variant for the observed dermatological and neurological signs in the investigated dog.
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Affiliation(s)
- Matthias Christen
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3001 Bern, Switzerland; (M.C.); (V.J.)
| | - Madeleine de le Roi
- Department of Pathology, University of Veterinary Medicine Hannover, 30559 Hannover, Germany; (M.d.l.R.); (K.B.)
| | - Vidhya Jagannathan
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3001 Bern, Switzerland; (M.C.); (V.J.)
| | - Kathrin Becker
- Department of Pathology, University of Veterinary Medicine Hannover, 30559 Hannover, Germany; (M.d.l.R.); (K.B.)
| | - Tosso Leeb
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3001 Bern, Switzerland; (M.C.); (V.J.)
- Correspondence: ; Tel.: +41-31-684-23-26
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Zhang Q, Zhao YZ, Ma HH, Wang D, Zhang N, Li ZG, Zhang R. Successful rescue of a lethal Griscelli syndrome type 2 presenting with neurological involvement and hemophagocytic lymphohistiocytosis: a case report. BMC Pediatr 2021; 21:253. [PMID: 34058999 PMCID: PMC8167959 DOI: 10.1186/s12887-021-02720-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 05/18/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Griscelli syndrome type 2 (GS2) is a rare autosomal recessive disease caused by mutations in RAB27A gene. It is primarily characterized by a combination of partial albinism, hemophagocytic lymphohistiocytosis (HLH) or other immunodeficiency. However, neurological involvement at onset in GS2 and treatment has rarely been described. CASE PRESENTATION We describe a 3-year-old boy with GS2 in an Asian Chinese family. He presented with progressive neurological abnormalities following unremitting fever at onset. He developed HLH during the clinical course. A novel homozygous mutation (c.1 A > G) in RAB27A gene was subsequently identified. He was then treated by HLH-1994 protocol combined with ruxolitinib and experienced a dramatic remission. He subsequently underwent a successful haploidentical hematopoietic stem cell transplantation and stayed at a good condition. CONCLUSIONS We reported an atypical form of GS2 manifesting as severe central nervous system involvement at onset and subsequent HLH, which was successfully rescued in time. This case also highlights the need for early consideration of immunologic and genetic evaluation for HLH in unexplained neuroinflammation in the diagnostic work up.
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Affiliation(s)
- Qing Zhang
- Hematologic Disease Laboratory; Hematology Center; Beijing Key Laboratory of Pediatric Hematology Oncology; National Key Discipline of Pediatrics (Capital Medical University); Key Laboratory of Major Diseases in Children, Ministry of Education; Beijing Pediatric Research Institute;, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, 100045, Beijing, China
| | - Yun-Ze Zhao
- Hematology Center; Beijing Key Laboratory of Pediatric Hematology Oncology; National Key Discipline of Pediatrics (Capital Medical University); Key Laboratory of Major Diseases in Children, Ministry of Education; Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, 100045, Beijing, China
| | - Hong-Hao Ma
- Hematology Center; Beijing Key Laboratory of Pediatric Hematology Oncology; National Key Discipline of Pediatrics (Capital Medical University); Key Laboratory of Major Diseases in Children, Ministry of Education; Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, 100045, Beijing, China
| | - Dong Wang
- Hematology Center; Beijing Key Laboratory of Pediatric Hematology Oncology; National Key Discipline of Pediatrics (Capital Medical University); Key Laboratory of Major Diseases in Children, Ministry of Education; Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, 100045, Beijing, China
| | - Nan Zhang
- Department of Pathology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, 100045, Beijing, China
| | - Zhi-Gang Li
- Hematologic Disease Laboratory; Hematology Center; Beijing Key Laboratory of Pediatric Hematology Oncology; National Key Discipline of Pediatrics (Capital Medical University); Key Laboratory of Major Diseases in Children, Ministry of Education; Beijing Pediatric Research Institute;, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, 100045, Beijing, China
| | - Rui Zhang
- Hematology Center; Beijing Key Laboratory of Pediatric Hematology Oncology; National Key Discipline of Pediatrics (Capital Medical University); Key Laboratory of Major Diseases in Children, Ministry of Education; Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, 100045, Beijing, China.
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11
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A role for Dynlt3 in melanosome movement, distribution, acidity and transfer. Commun Biol 2021; 4:423. [PMID: 33772156 PMCID: PMC7997999 DOI: 10.1038/s42003-021-01917-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 02/25/2021] [Indexed: 12/17/2022] Open
Abstract
Skin pigmentation is dependent on cellular processes including melanosome biogenesis, transport, maturation and transfer to keratinocytes. However, how the cells finely control these processes in space and time to ensure proper pigmentation remains unclear. Here, we show that a component of the cytoplasmic dynein complex, Dynlt3, is required for efficient melanosome transport, acidity and transfer. In Mus musculus melanocytes with decreased levels of Dynlt3, pigmented melanosomes undergo a more directional motion, leading to their peripheral location in the cell. Stage IV melanosomes are more acidic, but still heavily pigmented, resulting in a less efficient melanosome transfer. Finally, the level of Dynlt3 is dependent on β-catenin activity, revealing a function of the Wnt/β-catenin signalling pathway during melanocyte and skin pigmentation, by coupling the transport, positioning and acidity of melanosomes required for their transfer.
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12
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Ohishi Y, Ammann S, Ziaee V, Strege K, Groß M, Amos CV, Shahrooei M, Ashournia P, Razaghian A, Griffiths GM, Ehl S, Fukuda M, Parvaneh N. Griscelli Syndrome Type 2 Sine Albinism: Unraveling Differential RAB27A Effector Engagement. Front Immunol 2020; 11:612977. [PMID: 33362801 PMCID: PMC7758216 DOI: 10.3389/fimmu.2020.612977] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 11/03/2020] [Indexed: 12/30/2022] Open
Abstract
Griscelli syndrome type 2 (GS-2) is an inborn error of immunity characterized by partial albinism and episodes of hemophagocytic lymphohistiocytosis (HLH). It is caused by RAB27A mutations that encode RAB27A, a member of the Rab GTPase family. RAB27A is expressed in many tissues and regulates vesicular transport and organelle dynamics. Occasionally, GS-2 patients with RAB27A mutation display normal pigmentation. The study of such variants provides the opportunity to map distinct binding sites for tissue-specific effectors on RAB27A. Here we present a new case of GS-2 without albinism (GS-2 sine albinism) caused by a novel missense mutation (Val143Ala) in the RAB27A and characterize its functional cellular consequences. Using pertinent animal cell lines, the Val143Ala mutation impairs both the RAB27A–SLP2-A interaction and RAB27A–MUNC13-4 interaction, but it does not affect the RAB27A–melanophilin (MLPH)/SLAC2-A interaction that is crucial for skin and hair pigmentation. We conclude that disruption of the RAB27A–MUNC13-4 interaction in cytotoxic lymphocytes leads to the HLH predisposition of the GS-2 patient with the Val143Ala mutation. Finally, we include a review of GS-2 sine albinism cases reported in the literature, summarizing their genetic and clinical characteristics.
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Affiliation(s)
- Yuta Ohishi
- Laboratory of Membrane Trafficking Mechanisms, Department of Integrative Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Japan
| | - Sandra Ammann
- Institute for Immunodeficiency, Center for Chronic Immunodeficiency, Faculty of Medicine, Medical Center-University of Freiburg, University of Freiburg, Freiburg, Germany.,Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Vahid Ziaee
- Department of Pediatrics, Tehran University of Medical Sciences (TUMS), Tehran, Iran.,Pediatric Rheumatology Research Group, Rheumatology Research Center, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Katharina Strege
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Miriam Groß
- Institute for Immunodeficiency, Center for Chronic Immunodeficiency, Faculty of Medicine, Medical Center-University of Freiburg, University of Freiburg, Freiburg, Germany
| | - Carla Vazquez Amos
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Mohammad Shahrooei
- Laboratory of Clinical Bacteriology and Mycology, Department of Microbiology and Immunology, KU Leuven, Leuven, Belgium
| | - Parisa Ashournia
- Division of Allergy and Clinical Immunology, Department of Pediatrics, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Anahita Razaghian
- Division of Allergy and Clinical Immunology, Department of Pediatrics, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Gillian M Griffiths
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Stephan Ehl
- Institute for Immunodeficiency, Center for Chronic Immunodeficiency, Faculty of Medicine, Medical Center-University of Freiburg, University of Freiburg, Freiburg, Germany
| | - Mitsunori Fukuda
- Laboratory of Membrane Trafficking Mechanisms, Department of Integrative Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Japan
| | - Nima Parvaneh
- Division of Allergy and Clinical Immunology, Department of Pediatrics, Tehran University of Medical Sciences (TUMS), Tehran, Iran.,Research Center for Immunodeficiencies, Tehran University of Medical Sciences (TUMS), Tehran, Iran
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13
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Ku KE, Choi N, Sung JH. Inhibition of Rab27a and Rab27b Has Opposite Effects on the Regulation of Hair Cycle and Hair Growth. Int J Mol Sci 2020; 21:ijms21165672. [PMID: 32784729 PMCID: PMC7460818 DOI: 10.3390/ijms21165672] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 08/02/2020] [Accepted: 08/05/2020] [Indexed: 02/07/2023] Open
Abstract
Rab27a/b are known to play an important role in the transport of melanosomes, with their knockout causing silvery gray hair. However, the relationship between Rab27a/b and hair growth is not well known. To evaluate the role of Rab27a/b in hair cycle, we investigated the expression of Rab27a/b during hair cycling and human outer root sheath (hORS) cells. The expression of Rab27a in ORS cells was mainly detected at the anagen, whereas expression of Rab27b in ORS, and epidermal cells was strongly expressed at the telogen. Additionally, Rab27a/b were expressed in the Golgi of hORS cells. To evaluate the role of Rab27a/b in hair growth, telogen-to-anagen transition animal and vibrissae hair follicles (HFs) organ culture models were assayed using Rab27a/b siRNAs. The knockdown of Rab27a or Rab27b suppressed or promoted hair growth, respectively. These results were also confirmed in human dermal papilla cells (hDPCs) and hORS cells, showing the opposite mitogenic effects. Moreover, Rab27b knockdown increased the expression levels of various growth factors in the hDPCs and hORS cells. Overall, the opposite temporal expression patterns during hair cycling and roles for hair growth of Rab27a/b suggested that Rab27a/b might regulate the hair cycle. Therefore, our study may provide a novel solution for the development of hair loss treatment by regulating Rab27a/b levels.
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Affiliation(s)
- Kyung-Eun Ku
- College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon 21983, Korea;
| | | | - Jong-Hyuk Sung
- College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon 21983, Korea;
- STEMORE Co. Ltd., Incheon 21983, Korea;
- Correspondence: ; Tel.: +82-32-749-4506
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14
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Bowman SL, Bi-Karchin J, Le L, Marks MS. The road to lysosome-related organelles: Insights from Hermansky-Pudlak syndrome and other rare diseases. Traffic 2020; 20:404-435. [PMID: 30945407 DOI: 10.1111/tra.12646] [Citation(s) in RCA: 120] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 04/02/2019] [Accepted: 04/02/2019] [Indexed: 12/11/2022]
Abstract
Lysosome-related organelles (LROs) comprise a diverse group of cell type-specific, membrane-bound subcellular organelles that derive at least in part from the endolysosomal system but that have unique contents, morphologies and functions to support specific physiological roles. They include: melanosomes that provide pigment to our eyes and skin; alpha and dense granules in platelets, and lytic granules in cytotoxic T cells and natural killer cells, which release effectors to regulate hemostasis and immunity; and distinct classes of lamellar bodies in lung epithelial cells and keratinocytes that support lung plasticity and skin lubrication. The formation, maturation and/or secretion of subsets of LROs are dysfunctional or entirely absent in a number of hereditary syndromic disorders, including in particular the Hermansky-Pudlak syndromes. This review provides a comprehensive overview of LROs in humans and model organisms and presents our current understanding of how the products of genes that are defective in heritable diseases impact their formation, motility and ultimate secretion.
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Affiliation(s)
- Shanna L Bowman
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania.,Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Jing Bi-Karchin
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania.,Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Linh Le
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania.,Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Michael S Marks
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania.,Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
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15
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Yarwood R, Hellicar J, Woodman PG, Lowe M. Membrane trafficking in health and disease. Dis Model Mech 2020; 13:13/4/dmm043448. [PMID: 32433026 PMCID: PMC7197876 DOI: 10.1242/dmm.043448] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Membrane trafficking pathways are essential for the viability and growth of cells, and play a major role in the interaction of cells with their environment. In this At a Glance article and accompanying poster, we outline the major cellular trafficking pathways and discuss how defects in the function of the molecular machinery that mediates this transport lead to various diseases in humans. We also briefly discuss possible therapeutic approaches that may be used in the future treatment of trafficking-based disorders. Summary: This At a Glance article and poster summarise the major intracellular membrane trafficking pathways and associated molecular machineries, and describe how defects in these give rise to disease in humans.
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Affiliation(s)
- Rebecca Yarwood
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PT, UK
| | - John Hellicar
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PT, UK
| | - Philip G Woodman
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PT, UK
| | - Martin Lowe
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PT, UK
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16
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Hematopoietic stem cell transplantation in children with Griscelli syndrome type 2: a single-center report on 35 patients. Bone Marrow Transplant 2020; 55:2026-2034. [PMID: 32286505 DOI: 10.1038/s41409-020-0885-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 03/17/2020] [Accepted: 03/23/2020] [Indexed: 01/25/2023]
Abstract
In 2010, we reported the outcome of hematopoietic stem cell transplantation (HSCT) in 11 children with Griscelli syndrome type 2 (GS2). We report here the update on this cohort to include 35 patients. Twenty-seven (77%) patients received conditioning regimen including busulfan, cyclophosphamide with etoposide. Eight (23%) were given busulfan, fludarabine. Thiotepa was added to busulfan and fludarabine regimen in two patients; one received haploidentical marrow and one unrelated cord blood. Posttransplant clinical events included veno-occlusive disease (n = 7), acute (n = 8), or chronic (n = 1) graft-versus-host disease II-IV. With a mortality rate of 37.1% (n = 13) and a median follow-up of 87.7 months of the survivors, 5-year cumulative probability of overall survival (OS) for our cohort of patients was 62.7% (±8.2%). Cumulative probability of 5-year OS was significantly better in those who did not have hemophagocytic lymphohistiocytosis (HLH) prior to HSCT (100% vs. 53.3 ± 9.5%, P value: 0.042). Of the 16 patients with neurologic involvement before HSCT, 8 survived and 3 presented sequelae. OS at 5-year was 50 ± 12.5% and 73.3 ± 10.2% (P value: 0.320) in patients with and without CNS involvement, respectively. In conclusion, HSCT in patients with GS2 is potentially curative with long-term disease-free survival. Early HSCT before the development of the accelerated phase is associated with a better outcome.
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17
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Lee JA, Hwang SJ, Hong SC, Myung CH, Lee JE, Park JI, Hwang JS. Identification of MicroRNA Targeting Mlph and Affecting Melanosome Transport. Biomolecules 2019; 9:biom9070265. [PMID: 31288473 PMCID: PMC6681522 DOI: 10.3390/biom9070265] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 07/05/2019] [Accepted: 07/06/2019] [Indexed: 01/13/2023] Open
Abstract
Melanosomes undergo a complex maturation process and migrate into keratinocytes. Melanophilin (Mlph), a protein complex involving myosin Va (MyoVa) and Rab27a, enables the movement of melanosomes in melanocytes. In this study, we found six miRNAs targeting Mlph in mouse using two programs (http://targetscan.org and DianaTools). When melan-a melanocytes were treated with six synthesized microRNAs, miR-342-5p, miR-1839-5p, and miR-3082-5p inhibited melanosome transport and induced melanosome aggregation around the nucleus. The other microRNAs, miR-5110, miR-3090-3p, and miR-186-5p, did not inhibit melanosome transport. Further, miR-342-5p, miR-1839-5p, and miR-3082-5p decreased Mlph expression. The effect of miR-342-5p was the strongest among the six synthesized miRNAs. It inhibited melanosome transport in melan-a melanocytes and reduced Mlph expression in mRNA and protein levels in a dose-dependent manner; however, it did not affect Rab27a and MyoVa expressions, which are associated with melanosome transport. To examine miR-342-5p specificity, we performed luciferase assays in a mouse melanocyte-transfected reporter vector including Mlph at the 3′-UTR (untranslated region). When treated with miR-342-5p, luciferase activity that had been reduced by approximately 50% was restored after inhibitor treatment. Therefore, we identified a novel miRNA affecting Mlph and melanosome transport, and these results can be used for understanding Mlph expression and skin pigmentation regulation.
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Affiliation(s)
- Jeong Ah Lee
- Department of Genetic Engineering & Graduate School of Biotechnology, Kyung Hee University, Yongin, Gyeonggi-do 446-701, Korea
| | - Seok Joon Hwang
- Department of Genetic Engineering & Graduate School of Biotechnology, Kyung Hee University, Yongin, Gyeonggi-do 446-701, Korea
| | - Sung Chan Hong
- Department of Genetic Engineering & Graduate School of Biotechnology, Kyung Hee University, Yongin, Gyeonggi-do 446-701, Korea
| | - Cheol Hwan Myung
- Department of Genetic Engineering & Graduate School of Biotechnology, Kyung Hee University, Yongin, Gyeonggi-do 446-701, Korea
| | - Ji Eun Lee
- Department of Genetic Engineering & Graduate School of Biotechnology, Kyung Hee University, Yongin, Gyeonggi-do 446-701, Korea
| | - Jong Il Park
- Department of Genetic Engineering & Graduate School of Biotechnology, Kyung Hee University, Yongin, Gyeonggi-do 446-701, Korea
| | - Jae Sung Hwang
- Department of Genetic Engineering & Graduate School of Biotechnology, Kyung Hee University, Yongin, Gyeonggi-do 446-701, Korea.
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18
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Demars J, Iannuccelli N, Utzeri VJ, Auvinet G, Riquet J, Fontanesi L, Allain D. New Insights into the Melanophilin ( MLPH) Gene Affecting Coat Color Dilution in Rabbits. Genes (Basel) 2018; 9:genes9090430. [PMID: 30142960 PMCID: PMC6162760 DOI: 10.3390/genes9090430] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 08/06/2018] [Accepted: 08/13/2018] [Indexed: 11/16/2022] Open
Abstract
Coat color dilution corresponds to a specific pigmentation phenotype that leads to a dilution of wild type pigments. It affects both eumelanin and pheomelanin containing melanosomes. The mode of inheritance of the dilution phenotype is autosomal recessive. Candidate gene approaches focused on the melanophilin (MLPH) gene highlighted two variants associated with the dilution phenotype in rabbits: The c.111-5C>A variant that is located in an acceptor splice site or the c.585delG variant, a frameshift mutation. On the transcript level, the skipping of two exons has been reported as the molecular mechanism responsible for the coat color dilution. To clarify, which of the two variants represents the causal variant, (i) we analyzed their allelic segregation by genotyping Castor and Chinchilla populations, and (ii) we evaluated their functional effects on the stability of MLPH transcripts in skin samples of animals with diluted or wild type coat color. Firstly, we showed that the c.585delG variant showed perfect association with the dilution phenotype in contrast to the intronic c.111-5C>A variant. Secondly, we identified three different MLPH isoforms including the wild type isoform, the exon-skipping isoform and a retained intron isoform. Thirdly, we observed a drastic and significant decrease of MLPH transcript levels in rabbits with a coat color dilution (p-values ranging from 10−03 to 10−06). Together, our results bring new insights into the coat color dilution trait.
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Affiliation(s)
- Julie Demars
- GenPhySE, INRA Animal Genetics, Toulouse Veterinary School (ENVT), Université de Toulouse, 31326 Castanet Tolosan, France.
| | - Nathalie Iannuccelli
- GenPhySE, INRA Animal Genetics, Toulouse Veterinary School (ENVT), Université de Toulouse, 31326 Castanet Tolosan, France.
| | - Valerio Joe Utzeri
- Department of Agricultural and Food Sciences (DISTAL), Division of Animal Sciences, University of Bologna, 40127 Bologna, Italy.
| | | | - Juliette Riquet
- GenPhySE, INRA Animal Genetics, Toulouse Veterinary School (ENVT), Université de Toulouse, 31326 Castanet Tolosan, France.
| | - Luca Fontanesi
- Department of Agricultural and Food Sciences (DISTAL), Division of Animal Sciences, University of Bologna, 40127 Bologna, Italy.
| | - Daniel Allain
- GenPhySE, INRA Animal Genetics, Toulouse Veterinary School (ENVT), Université de Toulouse, 31326 Castanet Tolosan, France.
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19
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Zhao X, Zhang W, Ji W. MYO5A inhibition by miR-145 acts as a predictive marker of occult neck lymph node metastasis in human laryngeal squamous cell carcinoma. Onco Targets Ther 2018; 11:3619-3635. [PMID: 29950866 PMCID: PMC6016585 DOI: 10.2147/ott.s164597] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
INTRODUCTION Each year, ~50,000 patients worldwide die of laryngeal squamous cell carcinoma (LSCC) because of its highly metastatic properties. However, its pathogenic mechanisms are still unclear, and in particular, the prediction of metastasis remains elusive. This study aimed to define the role of microRNA-145 (miR-145) in LSCC progression. We also aimed to elucidate the clinical significance of the miR-145/MYO5A pathway, especially the predictive function of MYO5A in neck lymph node metastasis. MATERIALS AND METHODS MYO5A and miR-145 expression was analyzed in 132 patients with LSCC, and associations between their expression and clinicopathological features were evaluated. We validated the regulatory relationship between miR-145b and MYO5A by dual luciferase reporter assay. The role of the miR-145/MYO5A pathway in proliferation, metastasis, and apoptosis was examined in vitro. The predictive functions of MYO5A in neck lymph node metastasis and prognosis were defined according to patient follow-up. RESULTS Our results showed downregulation of miR-145 in LSCC, which was negatively correlated with MYO5A suppression of LSCC progression and metastasis. MiR-145 directly regulated MYO5A expression in vitro and suppressed LSCC proliferation and invasion while promoting apoptosis by inhibiting MYO5A. CONCLUSION Notably, overexpression of serum MYO5A in LSCC predicted cervical nodal occult metastasis and poor prognosis, providing an effective indicator for predicting neck lymph node metastasis and assessing LSCC prognosis.
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Affiliation(s)
- Xudong Zhao
- Department of Otorhinolaryngology, Shengjing Hospital, China Medical University, Shenyang, China
| | - Wei Zhang
- Department of Endocrinology, Shengjing Hospital, China Medical University, Shenyang, China
| | - Wenyue Ji
- Department of Otorhinolaryngology, Shengjing Hospital, China Medical University, Shenyang, China
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20
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Lachance J, Berens AJ, Hansen MEB, Teng AK, Tishkoff SA, Rebbeck TR. Genetic Hitchhiking and Population Bottlenecks Contribute to Prostate Cancer Disparities in Men of African Descent. Cancer Res 2018; 78:2432-2443. [PMID: 29438991 PMCID: PMC5932264 DOI: 10.1158/0008-5472.can-17-1550] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 11/02/2017] [Accepted: 02/05/2018] [Indexed: 12/24/2022]
Abstract
Prostate cancer incidence and mortality rates in African and African American men are greatly elevated compared with other ethnicities. This disparity is likely explained by a combination of social, environmental, and genetic factors. A large number of susceptibility loci have been reported by genome-wide association studies (GWAS), but the contribution of these loci to prostate cancer disparities is unclear. Here, we investigated the population structure of 68 previously reported GWAS loci and calculated genetic disparity contribution statistics to identify SNPs that contribute the most to differences in prostate cancer risk across populations. By integrating GWAS results with allele frequency data, we generated genetic risk scores for 45 African and 19 non-African populations. Tests of natural selection were used to assess why some SNPs have large allele frequency differences across populations. We report that genetic predictions of prostate cancer risks are highest for West African men and lowest for East Asian men. These differences may be explained by the out-of-Africa bottleneck and natural selection. A small number of loci appear to drive elevated prostate cancer risks in men of African descent, including rs9623117, rs6983267, rs10896449, rs10993994, and rs817826. Although most prostate cancer-associated loci are evolving neutrally, there are multiple instances where alleles have hitchhiked to high frequencies with linked adaptive alleles. For example, a protective allele at 2q37 appears to have risen to high frequency in Europe due to selection acting on pigmentation. Our results suggest that evolutionary history contributes to the high rates of prostate cancer in African and African American men.Significance: A small number of genetic variants cause an elevated risk of prostate cancer in men of West African descent. Cancer Res; 78(9); 2432-43. ©2018 AACR.
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Affiliation(s)
- Joseph Lachance
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia.
| | - Ali J Berens
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia
| | - Matthew E B Hansen
- Department of Biology and Genetics, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Andrew K Teng
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia
| | - Sarah A Tishkoff
- Department of Biology and Genetics, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Timothy R Rebbeck
- Dana-Farber Cancer Institute and Harvard T. H. Chan School of Public Health, Boston, Massachusetts
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21
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No novel, high penetrant gene might remain to be found in Japanese patients with unknown MODY. J Hum Genet 2018; 63:821-829. [PMID: 29670293 DOI: 10.1038/s10038-018-0449-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 03/07/2018] [Accepted: 03/09/2018] [Indexed: 11/08/2022]
Abstract
MODY 5 and 6 have been shown to be low-penetrant MODYs. As the genetic background of unknown MODY is assumed to be similar, a new analytical strategy is applied here to elucidate genetic predispositions to unknown MODY. We examined to find whether there are major MODY gene loci remaining to be identified using SNP linkage analysis in Japanese. Whole-exome sequencing was performed with seven families with typical MODY. Candidates for novel MODY genes were examined combined with in silico network analysis. Some peaks were found only in either parametric or non-parametric analysis; however, none of these peaks showed a LOD score greater than 3.7, which is approved to be the significance threshold of evidence for linkage. Exome sequencing revealed that three mutated genes were common among 3 families and 42 mutated genes were common in two families. Only one of these genes, MYO5A, having rare amino acid mutations p.R849Q and p.V1601G, was involved in the biological network of known MODY genes through the intermediary of the INS. Although only one promising candidate gene, MYO5A, was identified, no novel, high penetrant MODY genes might remain to be found in Japanese MODY.
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22
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Sefsafi Z, Hasbaoui BE, Kili A, Agadr A, Khattab M. Macrophage activation syndrome associated with griscelli syndrome type 2: case report and review of literature. Pan Afr Med J 2018; 29:75. [PMID: 29875956 PMCID: PMC5987098 DOI: 10.11604/pamj.2018.29.75.12353] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Accepted: 12/19/2017] [Indexed: 11/13/2022] Open
Abstract
Macrophage activation syndrome (MAS) is a severe and potentially fatal life-threatening condition associated with excessive activation and expansion of T cells with macrophages and a high expression of cytokines, resulting in an uncontrolled inflammatory response, with high levels of macrophage colony-stimulating factor and causing multiorgan damage. This syndrome is classified into primary (genetic/familial) or secondary forms to several etiologies, such as infections, neoplasias mainly hemopathies or autoimmune diseases. It is characterised clinically by unremitting high fever, pancytopaenia, hepatosplenomegaly, hepatic dysfunction, encephalopathy, coagulation abnormalities and sharply increased levels of ferritin. The pathognomonic feature of the syndrome is seen on bone marrow examination, which frequently, though not always, reveals numerous morphologically benign macrophages exhibiting haemophagocytic activity. Because MAS can follow a rapidly fatal course, prompt recognition of its clinical and laboratory features and immediate therapeutic intervention are essential. However, it is difficult to distinguish underlying disease flare, infectious complications or medication side effects from MAS. Although, the pathogenesis of MAS is unclear, the hallmark of the syndrome is an uncontrolled activation and proliferation of T lymphocytes and macrophages, leading to massive hypersecretion of pro-inflammatory cytokines. Mutations in cytolytic pathway genes are increasingly being recognised in children who develop MAS in his secondary form. We present here a case of Macrophage activation syndrome associated with Griscelli syndrome type 2 in a 3-years-old boy who had been referred due to severe sepsis with non-remitting high fever, generalized lymphoadenopathy and hepato-splenomegaly. Laboratory data revealed pancytopenia with high concentrations of triglycerides, ferritin and lactic dehydrogenase while the bone marrow revealed numerous morphologically benign macrophages with haemophagocytic activity that comforting the diagnosis of a SAM according to Ravelli and HLH-2004 criteria. Griscelli syndrome (GS) was evoked on; consanguineous family, recurrent infection, very light silvery-gray color of the hair and eyebrows, Light microscopy examination of the hair showed large, irregular clumps of pigments characteristic of GS. The molecular biology showed mutation in RAB27A gene confirming the diagnosis of a Griscelli syndrome type 2. The first-line therapy was based on the parenteral administration of high doses of corticosteroids, associated with immunosuppressive drugs, cyclosporine A and etoposide waiting for bone marrow transplantation (BMT).
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Affiliation(s)
- Zakia Sefsafi
- Center for Hematology and Oncology Paediatrics, Children's hospital, Faculty of Medicine and Pharmacy, University Mohammed V, Rabat, Morocco
| | - Brahim El Hasbaoui
- Department of Pediatrics, Military Teaching Hospital Mohammed V, Faculty of Medicine and Pharmacy, University Mohammed V, Rabat, Morocco
| | - Amina Kili
- Center for Hematology and Oncology Paediatrics, Children's hospital, Faculty of Medicine and Pharmacy, University Mohammed V, Rabat, Morocco
| | - Aomar Agadr
- Department of Pediatrics, Military Teaching Hospital Mohammed V, Faculty of Medicine and Pharmacy, University Mohammed V, Rabat, Morocco
| | - Mohammed Khattab
- Center for Hematology and Oncology Paediatrics, Children's hospital, Faculty of Medicine and Pharmacy, University Mohammed V, Rabat, Morocco
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Two Variants in SLC24A5 Are Associated with "Tiger-Eye" Iris Pigmentation in Puerto Rican Paso Fino Horses. G3-GENES GENOMES GENETICS 2017; 7:2799-2806. [PMID: 28655738 PMCID: PMC5555483 DOI: 10.1534/g3.117.043786] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A unique eye color, called tiger-eye, segregates in the Puerto Rican Paso Fino (PRPF) horse breed and is characterized by a bright yellow, amber, or orange iris. Pedigree analysis identified a simple autosomal recessive mode of inheritance for this trait. A genome-wide association study (GWAS) with 24 individuals identified a locus on ECA 1 reaching genome-wide significance (Pcorrected = 1.32 × 10−5). This ECA1 locus harbors the candidate gene, Solute Carrier Family 24 (Sodium/Potassium/Calcium Exchanger), Member 5 (SLC24A5), with known roles in pigmentation in humans, mice, and zebrafish. Humans with compound heterozygous mutations in SLC24A5 have oculocutaneous albinism (OCA) type 6 (OCA6), which is characterized by dilute skin, hair, and eye pigmentation, as well as ocular anomalies. Twenty tiger-eye horses were homozygous for a nonsynonymous mutation in exon 2 (p.Phe91Tyr) of SLC24A5 (called here Tiger-eye 1), which is predicted to be deleterious to protein function. Additionally, eight of the remaining 12 tiger-eye horses heterozygous for the p.Phe91Tyr variant were also heterozygous for a 628 bp deletion encompassing all of exon 7 of SLC24A5 (c.875-340_1081+82del), which we will call here the Tiger-eye 2 allele. None of the 122 brown-eyed horses were homozygous for either tiger-eye-associated allele or were compound heterozygotes. Further, neither variant was detected in 196 horses from four related breeds not known to have the tiger-eye phenotype. Here, we propose that two mutations in SLC24A5 affect iris pigmentation in tiger-eye PRPF horses. Further, unlike OCA6 in humans, the Tiger-eye 1 mutation in its homozygous state or as a compound heterozygote (Tiger-eye 1/Tiger-eye 2) does not appear to cause ocular anomalies or a change in coat color in the PRPF horse.
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Stahl BA, Gross JB. A Comparative Transcriptomic Analysis of Development in Two Astyanax Cavefish Populations. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2017; 328:515-532. [PMID: 28612405 DOI: 10.1002/jez.b.22749] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 03/24/2017] [Accepted: 04/11/2017] [Indexed: 12/11/2022]
Abstract
Organisms that are isolated into extreme environments often evolve extreme phenotypes. However, global patterns of dynamic gene expression changes that accompany dramatic environmental changes remain largely unknown. The blind Mexican cavefish, Astyanax mexicanus, has evolved a number of severe cave-associated phenotypes including loss of vision and pigmentation, craniofacial bone fusions, increased fat storage, reduced sleep, and amplified nonvisual sensory systems. Interestingly, surface-dwelling forms have repeatedly entered different caves throughout Mexico, providing a natural set of "replicate" instances of cave isolation. These surrogate "ancestral" surface-dwelling forms persist in nearby rivers, enabling direct comparisons to the "derived" cave-dwelling form. We evaluated changes associated with subterranean isolation by measuring differential gene expression in two geographically distinct cave-dwelling populations (Pachón and Tinaja). To understand the impact of these expression changes on development, we performed RNA-sequencing across four critical stages during which troglomorphic traits first appear in cavefish embryos. Gene ontology (GO) studies revealed similar functional profiles evolved in both independent cave lineages. However, enrichment studies indicated that similar GO profiles were occasionally mediated by different genes. Certain "master" regulators, such as Otx2 and Mitf, appear to be important loci for cave adaptation, as remarkably similar patterns of expression were identified in both independent cave lineages. This work reveals that adaptation to an extreme environment, in two distinct cavefish lineages, evolves through a combination of unique and shared gene expression patterns. Shared expression profiles reflect common environmental pressures, while unique expression likely reflects the fact that similar adaptive traits evolve through diverse genetic mechanisms.
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Affiliation(s)
- Bethany A Stahl
- Department of Biological Sciences, University of Cincinnati, Cincinnati, Ohio
| | - Joshua B Gross
- Department of Biological Sciences, University of Cincinnati, Cincinnati, Ohio
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25
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Kudo M, Kobayashi-Nakamura K, Tsuji-Naito K. Bifunctional effects of O-methylated flavones from Scutellaria baicalensis Georgi on melanocytes: Inhibition of melanin production and intracellular melanosome transport. PLoS One 2017; 12:e0171513. [PMID: 28182699 PMCID: PMC5300169 DOI: 10.1371/journal.pone.0171513] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 01/20/2017] [Indexed: 02/07/2023] Open
Abstract
The growing interest in skin lightening has recently renewed attention on the esthetic applications of Chinese herbal medicine. Although Scutellaria baicalensis Georgi is used for antipyretic and antiinflammatory purposes, its whitening effect remains unclear. This study reports three major findings: (1) S. baicalensis has a potent inhibitory effect on melanogenesis; (2) wogonin and its glycoside are the active components of S. baicalensis; and (3) O-methylated flavones from S. baicalensis, such as wogonin, inhibit intracellular melanosome transport. Using a melanin quantification assay, we showed that S. baicalensis potently inhibits melanogenesis in B16F10 cells. Componential analyses revealed that the main components of S. baicalensis are baicalin, wogonoside, baicalein, wogonin, and oroxylin A. Among these five flavones, wogonin and wogonoside consistently inhibited melanogenesis in both B16F10 melanoma cells and primary melanocytes. Wogonin exhibited the strongest inhibition of melanin production and markedly lightened the color of skin equivalents. We identified microphthalmia-associated transcription factor and tyrosinase-related proteins as potential targets of wogonin- and wogonoside-induced melanogenesis suppression. In culture, we found that the melanosomes in wogonin-treated B16F10 cells were localized to the perinuclear region. Immunoblotting analyses revealed that wogonin significantly reduced in melanophilin protein, which is required for actin-based melanosome transport. Other actin-based melanosome transport-related molecules, i.e., Rab27A and myosin Va, were not affected by wogonin. Cotreatment with MG132 blocked the wogonin-induced decrease in melanophilin, suggesting that wogonin promotes the proteolytic degradation of melanophilin via the calpain/proteasomal pathway. We determined that the structural specificities of the mono-O-methyl group in the flavone A-ring and the aglycone form were responsible for reducing melanosome transport. Furthermore, wogonin and two wogonin analogs, mono-O-methyl flavones, strongly suppressed melanosome transport. Our findings suggest the applicability of S. baicalensis in the esthetic field. Thus, we propose a novel pharmacologic approach for the treatment of hyperpigmentation.
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Affiliation(s)
- Michiko Kudo
- Fundamental Research Laboratory, Fundamental Research Department, DHC Corporation, Chiba, Japan
| | | | - Kentaro Tsuji-Naito
- Fundamental Research Laboratory, Fundamental Research Department, DHC Corporation, Chiba, Japan
- * E-mail:
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26
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Katoulis AC, Daskari D, Liakou AI, Bozi E, Lianou D, Rigopoulos D. "Road-Dividing Line"-Like Pigmentation of Hair as a Diagnostic Clue for Griscelli Syndrome. Skin Appendage Disord 2017; 2:143-145. [PMID: 28232922 PMCID: PMC5264357 DOI: 10.1159/000452165] [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: 08/25/2016] [Accepted: 09/28/2016] [Indexed: 11/19/2022] Open
Abstract
We report a case of a 5-year-old girl with physical and psychomotor retardation, acquired microcephaly, and history of recurrent infections. Dermoscopic and microscopic hair examination revealed a "road-dividing line"-like pigmentation of hair shafts. The combination of history, clinical findings, and hair examination led to the diagnosis of Griscelli syndrome type II. The picture of "road-dividing line" on hair microscopic and dermoscopic examination is highly characteristic for Griscelli syndrome, and in this framework, dermatologic examination may be of high importance for the diagnosis.
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Affiliation(s)
| | | | - Aikaterini I. Liakou
- 2nd Department of Dermatology and Venereology, National and Kapodistrian University of Athens Medical School, “Attikon” University General Hospital, Athens, Greece
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Abstract
Griscelli syndrome (GS) is a rare autosomal recessive multisystem disorder of pigmentary dilution of skin, silver gray hair, variable immunodeficiency, neurological impairment, and abnormal accumulation of melanosomes in melanocytes. GS type 3 is characterized by hypomelanosis with no immunological and neurological manifestation. Prognosis is very good in type 3 GS and usually require no active intervention, as opposed to type 1 and 2 where early diagnosis and treatment plays a crucial role in patient's survival. The characteristic phenotypic appearance, especially the pigment dilution of the patient's hair, is emphasized here.
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Affiliation(s)
- Bela J Shah
- Department of Dermatology, BJ Medical College and Civil Hospital, Ahmedabad, Gujarat, India
| | - Ashish K Jagati
- Department of Dermatology, BJ Medical College and Civil Hospital, Ahmedabad, Gujarat, India
| | - Nilesh K Katrodiya
- Department of Dermatology, BJ Medical College and Civil Hospital, Ahmedabad, Gujarat, India
| | - Sonal M Patel
- Department of Dermatology, BJ Medical College and Civil Hospital, Ahmedabad, Gujarat, India
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28
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Murase D, Hachiya A, Kikuchi-Onoe M, Fullenkamp R, Ohuchi A, Kitahara T, Moriwaki S, Hase T, Takema Y. Cooperation of endothelin-1 signaling with melanosomes plays a role in developing and/or maintaining human skin hyperpigmentation. Biol Open 2015; 4:1213-21. [PMID: 26340945 PMCID: PMC4610214 DOI: 10.1242/bio.011973] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 07/30/2015] [Indexed: 12/11/2022] Open
Abstract
Skin hyperpigmentation is characterized by increased melanin synthesis and deposition that can cause significant psychosocial and psychological distress. Although several cytokine-receptor signaling cascades contribute to the formation of ultraviolet B-induced cutaneous hyperpigmentation, their possible involvement in other types of skin hyperpigmentation has never been clearly addressed. Since our continuous studies using skin specimens from more than 30 subjects with ethnic skin diversity emphasized a consistent augmentation in the expression of endothelin-1 (ET-1) and its receptor (Endothelin B receptor, ET-B) in hyperpigmented lesions, including senile lentigos (SLs), the precise function of ET-1 signaling was investigated in the present study. In line with previous studies, ET-1 significantly induced melanogenesis followed by increases in melanosome transport in melanocytes and in its transfer to keratinocytes while inhibition of ET-B function substantially depressed melanogenic ability in tissue-cultured SLs. Additionally, in agreement with a previous report that the formation of autophagosomes rather than melanosomes is stimulated according to starvation or defective melanosome production, ET-1 was found to remarkably augment the expression of components necessary for early melanosome formation, indicating its counteraction against autophagy-targeting melanosome degradation in melanocytes. Despite the lack of substantial impact of ET-1 on keratinocyte melanogenic functions, the expression of ET-1 was enhanced following melanosome uptake by keratinocytes. Taken together, our data suggest that ET-1 plays a substantial role in the development and/or maintenance of skin hyperpigmentation in reciprocal cooperation with increased melanosome incorporation.
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Affiliation(s)
- Daiki Murase
- Biological Science Laboratories, Kao Corporation, Haga, Tochigi 321-3497, Japan Biological Science Americas Laboratory, Kao Corporation, Cincinnati, OH 45214, USA
| | - Akira Hachiya
- Biological Science Laboratories, Kao Corporation, Haga, Tochigi 321-3497, Japan
| | - Mamiko Kikuchi-Onoe
- Biological Science Laboratories, Kao Corporation, Haga, Tochigi 321-3497, Japan
| | - Rachel Fullenkamp
- Biological Science Americas Laboratory, Kao Corporation, Cincinnati, OH 45214, USA
| | - Atsushi Ohuchi
- Biological Science Laboratories, Kao Corporation, Haga, Tochigi 321-3497, Japan
| | - Takashi Kitahara
- Biological Science Laboratories, Kao Corporation, Haga, Tochigi 321-3497, Japan
| | - Shigeru Moriwaki
- Biological Science Laboratories, Kao Corporation, Haga, Tochigi 321-3497, Japan
| | - Tadashi Hase
- Biological Science Laboratories, Kao Corporation, Haga, Tochigi 321-3497, Japan
| | - Yoshinori Takema
- Research and Development Global, Kao Corporation, Sumida-ku, Tokyo 131-8501, Japan
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29
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Optimization of cerebellar purkinje neuron cultures and development of a plasmid-based method for purkinje neuron-specific, miRNA-mediated protein knockdown. Methods Cell Biol 2015; 131:177-97. [PMID: 26794514 DOI: 10.1016/bs.mcb.2015.06.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We present a simple and efficient method to knock down proteins specifically in Purkinje neurons (PN) present in mixed mouse primary cerebellar cultures. This method utilizes the introduction via nucleofection of a plasmid encoding a specific miRNA downstream of the L7/Pcp2 promoter, which drives PN-specific expression. As proof-of-principle, we used this plasmid to knock down the motor protein myosin Va, which is required for the targeting of smooth endoplasmic reticulum (ER) into PN spines. Consistent with effective knockdown, transfected PNs robustly phenocopied PNs from dilute-lethal (myosin Va-null) mice with regard to the ER targeting defect. Importantly, our plasmid-based approach is less challenging technically and more specific to PNs than several alternative methods (e.g., biolistic- and lentiviral-based introduction of siRNAs). We also present a number of improvements for generating mixed cerebellar cultures that shorten the procedure and improve the total yield of PNs, and of transfected PNs, considerably. Finally, we present a method to rescue cerebellar cultures that develop large cell aggregates, a common problem that otherwise precludes the further use of the culture.
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30
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Yamaoka M, Ishizaki T, Kimura T. Interplay between Rab27a effectors in pancreatic β-cells. World J Diabetes 2015; 6:508-516. [PMID: 25897360 PMCID: PMC4398906 DOI: 10.4239/wjd.v6.i3.508] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 12/24/2014] [Accepted: 02/09/2015] [Indexed: 02/05/2023] Open
Abstract
The small GTPase Rab27a is a member of the Rab family that is involved in membrane trafficking in various kinds of cells. Rab27a has GTP- and GDP-bound forms, and their interconversion regulates intracellular signaling pathways. Typically, only a GTP-bound GTPase binds its specific effectors with the resulting downstream signals controlling specific cellular functions. We previously identified novel Rab27a-interacting proteins. Surprisingly, some of these proteins interacted with GDP-bound Rab27a. The present study reviews recent progress in our understanding of the roles of Rab27a and its effectors in the secretory process. In pancreatic β-cells, GTP-bound Rab27a regulates insulin secretion at the pre-exocytotic stages via its GTP-specific effectors such as Exophilin8/Slac2-c/MyRIP and Slp4/Granuphilin. Glucose stimulation causes insulin exocytosis. Glucose stimulation also converts Rab27a from its GTP- to its GDP-bound form. GDP-bound Rab27a interacts with GDP-specific effectors and controls endocytosis of the secretory membrane. Thus, Rab27a cycling between GTP- and GDP-bound forms synchronizes with the recycling of secretory membrane to re-use the membrane and keep the β-cell volume constant.
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31
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Souza CCR, Dombroski TCD, Machado HR, Oliveira RS, Rocha LB, Rodrigues ARA, Neder L, Chimelli L, Corrêa VMA, Larson RE, Martins AR. Myosin Va is developmentally regulated and expressed in the human cerebellum from birth to old age. Braz J Med Biol Res 2015; 46:164-70. [PMID: 23558932 PMCID: PMC3854355 DOI: 10.1590/1414-431x20122627] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2012] [Accepted: 12/03/2012] [Indexed: 12/04/2022] Open
Abstract
Myosin Va functions as a processive, actin-based motor molecule highly enriched
in the nervous system, which transports and/or tethers organelles, vesicles, and
mRNA and protein translation machinery. Mutation of myosin Va leads to Griscelli
disease that is associated with severe neurological deficits and a short life
span. Despite playing a critical role in development, the expression of myosin
Va in the central nervous system throughout the human life span has not been
reported. To address this issue, the cerebellar expression of myosin Va from
newborns to elderly humans was studied by immunohistochemistry using an
affinity-purified anti-myosin Va antibody. Myosin Va was expressed at all ages
from the 10th postnatal day to the 98th year of life, in molecular, Purkinje and
granular cerebellar layers. Cerebellar myosin Va expression did not differ
essentially in localization or intensity from childhood to old age, except
during the postnatal developmental period. Structures resembling granules and
climbing fibers in Purkinje cells were deeply stained. In dentate neurons, long
processes were deeply stained by anti-myosin Va, as were punctate nuclear
structures. During the first postnatal year, myosin Va was differentially
expressed in the external granular layer (EGL). In the EGL, proliferating
prospective granule cells were not stained by anti-myosin Va antibody. In
contrast, premigratory granule cells in the EGL stained moderately. Granule
cells exhibiting a migratory profile in the molecular layer were also moderately
stained. In conclusion, neuronal myosin Va is developmentally regulated, and
appears to be required for cerebellar function from early postnatal life to
senescence.
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Affiliation(s)
- C C R Souza
- Departamento de Neurologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
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Abstract
Griscelli syndrome type 2 is characterised by partial albinism and primary immunodeficiency. We present a case of a 3-year-old girl diagnosed with cerebellar involvement of Griscelli syndrome type 2. Neurological complications may accompany Griscelli syndrome, however, to the best of my knowledge there are only a few case reports of cerebellar involvement of Griscelli syndrome type 2 in the literature.
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Affiliation(s)
- Sedat Işikay
- Department of Pediatric Neurology, Gaziantep Children's Hospital, Gaziantep, Turkey
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Ishida M, Arai SP, Ohbayashi N, Fukuda M. The GTPase-deficient Rab27A(Q78L) mutant inhibits melanosome transport in melanocytes through trapping of Rab27A effector protein Slac2-a/melanophilin in their cytosol: development of a novel melanosome-targetinG tag. J Biol Chem 2014; 289:11059-11067. [PMID: 24584932 DOI: 10.1074/jbc.m114.552281] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The small GTPase Rab27A is a crucial regulator of actin-based melanosome transport in melanocytes, and functionally defective Rab27A causes human Griscelli syndrome type 2, which is characterized by silvery hair. A GTPase-deficient, constitutively active Rab27A(Q78L) mutant has been shown to act as an inhibitor of melanosome transport and to induce perinuclear aggregation of melanosomes, but the molecular mechanism by which Rab27A(Q78L) inhibits melanosome transport remained to be determined. In this study, we attempted to identify the primary cause of the perinuclear melanosome aggregation induced by Rab27A(Q78L). The results showed that Rab27A(Q78L) is unable to localize on mature melanosomes and that its inhibitory activity on melanosome transport is completely dependent on its binding to the Rab27A effector Slac2-a/melanophilin. When we forcibly expressed Rab27A(Q78L) on mature melanosomes by using a novel melanosome-targeting tag that we developed in this study and named the MST tag, the MST-Rab27A(Q78L) fusion protein behaved in the same manner as wild-type Rab27A. It localized on mature melanosomes without inducing melanosome aggregation and restored normal peripheral melanosome distribution in Rab27A-deficient cells. These findings indicate that the GTPase activity of Rab27A is required for its melanosome localization but is not required for melanosome transport.
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Affiliation(s)
- Morié Ishida
- Laboratory of Membrane Trafficking Mechanisms, Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai, Miyagi 980-8578, Japan
| | - Saki P Arai
- Laboratory of Membrane Trafficking Mechanisms, Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai, Miyagi 980-8578, Japan
| | - Norihiko Ohbayashi
- Laboratory of Membrane Trafficking Mechanisms, Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai, Miyagi 980-8578, Japan
| | - Mitsunori Fukuda
- Laboratory of Membrane Trafficking Mechanisms, Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai, Miyagi 980-8578, Japan.
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34
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Mishra K, Singla S, Sharma S, Saxena R, Batra VV. Griscelli syndrome type 2: a novel mutation in RAB27A gene with different clinical features in 2 siblings: a diagnostic conundrum. KOREAN JOURNAL OF PEDIATRICS 2014; 57:91-5. [PMID: 24678334 PMCID: PMC3965801 DOI: 10.3345/kjp.2014.57.2.91] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Revised: 03/11/2013] [Accepted: 05/28/2013] [Indexed: 11/27/2022]
Abstract
Griscelli syndrome type 2 (GS2) is a rare autosomal recessive disease caused by mutations in the RAB27A gene. It is characterized by cutaneous hypopigmentation, immunodeficiency, and hemophagocytic lymphohistiocytosis. We describe 2 brothers who had GS2 with clinically diverse manifestations. The elder brother presented with a purely neurological picture, whereas the younger one presented with fever, pancytopenia, hepatosplenomegaly, and erythema nodosum. Considering that cutaneous hypopigmentation was a common feature between the brothers, genetic analysis for Griscelli syndrome was performed. As the elder sibling had died, mutation analysis was only performed on the younger sibling, which revealed a novel homozygous mutation in the RAB27A gene on chromosome 15 showing a single-base substitution (c.136T>A p.F46I). Both parents were heterozygous for the same mutation. This confirmed the diagnosis of GS2 in the accelerated phase in both siblings. The atypical features of GS2 in these cases are a novel mutation, isolated neurological involvement in one sibling, association with erythema nodosum, and 2 distinct clinical presentations in siblings with the same genetic mutation.
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Affiliation(s)
- Kirtisudha Mishra
- Department of Pediatrics, Kalawati Saran Children's Hospital, Lady Hardinge Medical College, New Delhi, India
| | - Shilpy Singla
- Department of Pediatrics, Kalawati Saran Children's Hospital, Lady Hardinge Medical College, New Delhi, India
| | - Suvasini Sharma
- Department of Pediatrics, Kalawati Saran Children's Hospital, Lady Hardinge Medical College, New Delhi, India
| | - Renu Saxena
- Department of Molecular Genetics, Sir Ganga Ram Hospital, New Delhi, India
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Ham H, Billadeau DD. Human immunodeficiency syndromes affecting human natural killer cell cytolytic activity. Front Immunol 2014; 5:2. [PMID: 24478771 PMCID: PMC3896857 DOI: 10.3389/fimmu.2014.00002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 01/03/2014] [Indexed: 12/30/2022] Open
Abstract
Natural killer (NK) cells are lymphocytes of the innate immune system that secrete cytokines upon activation and mediate the killing of tumor cells and virus-infected cells, especially those that escape the adaptive T cell response caused by the down regulation of MHC-I. The induction of cytotoxicity requires that NK cells contact target cells through adhesion receptors, and initiate activation signaling leading to increased adhesion and accumulation of F-actin at the NK cell cytotoxic synapse. Concurrently, lytic granules undergo minus-end directed movement and accumulate at the microtubule-organizing center through the interaction with microtubule motor proteins, followed by polarization of the lethal cargo toward the target cell. Ultimately, myosin-dependent movement of the lytic granules toward the NK cell plasma membrane through F-actin channels, along with soluble N-ethylmaleimide-sensitive factor attachment protein receptor-dependent fusion, promotes the release of the lytic granule contents into the cleft between the NK cell and target cell resulting in target cell killing. Herein, we will discuss several disease-causing mutations in primary immunodeficiency syndromes and how they impact NK cell-mediated killing by disrupting distinct steps of this tightly regulated process.
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Affiliation(s)
- Hyoungjun Ham
- Department of Immunology, College of Medicine, Mayo Clinic , Rochester, MN , USA
| | - Daniel D Billadeau
- Department of Immunology, College of Medicine, Mayo Clinic , Rochester, MN , USA ; Division of Oncology Research and Schulze Center for Novel Therapeutics, College of Medicine, Mayo Clinic , Rochester, MN , USA
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Lehner S, Gähle M, Dierks C, Stelter R, Gerber J, Brehm R, Distl O. Two-exon skipping within MLPH is associated with coat color dilution in rabbits. PLoS One 2013; 8:e84525. [PMID: 24376820 PMCID: PMC3869861 DOI: 10.1371/journal.pone.0084525] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 11/15/2013] [Indexed: 11/19/2022] Open
Abstract
Coat color dilution turns black coat color to blue and red color to cream and is a characteristic in many mammalian species. Matings among Netherland Dwarf, Loh, and Lionhead Dwarf rabbits over two generations gave evidence for a monogenic autosomal recessive inheritance of coat colour dilution. Histological analyses showed non-uniformly distributed, large, agglomerating melanin granules in the hair bulbs of coat color diluted rabbits. We sequenced the cDNA of MLPH in two dilute and one black rabbit for polymorphism detection. In both color diluted rabbits, skipping of exons 3 and 4 was present resulting in altered amino acids at p.QGL[37-39]QWA and a premature stop codon at p.K40*. Sequencing of genomic DNA revealed a c.111-5C>A splice acceptor mutation within the polypyrimidine tract of intron 2 within MLPH. This mutation presumably causes skipping of exons 3 and 4. In 14/15 dilute rabbits, the c.111-5C>A mutation was homozygous and in a further dilute rabbit, heterozygous and in combination with a homozygous frame shift mutation within exon 6 (c.585delG). In conclusion, our results demonstrated a colour dilution associated MLPH splice variant causing a strongly truncated protein (p.Q37QfsX4). An involvement of further MLPH-associated mutations needs further investigations.
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Affiliation(s)
- Stefanie Lehner
- Institute for Animal Breeding and Genetics, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Marion Gähle
- Institute for Anatomy, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Claudia Dierks
- Institute for Animal Breeding and Genetics, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Ricarda Stelter
- Institute for Animal Breeding and Genetics, University of Veterinary Medicine Hannover, Hannover, Germany
- Clinic for Pets, Reptiles and Pet and Feral Birds, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Jonathan Gerber
- Institute for Anatomy, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Ralph Brehm
- Institute for Anatomy, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Ottmar Distl
- Institute for Animal Breeding and Genetics, University of Veterinary Medicine Hannover, Hannover, Germany
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Dotta L, Parolini S, Prandini A, Tabellini G, Antolini M, Kingsmore SF, Badolato R. Clinical, laboratory and molecular signs of immunodeficiency in patients with partial oculo-cutaneous albinism. Orphanet J Rare Dis 2013; 8:168. [PMID: 24134793 PMCID: PMC3856608 DOI: 10.1186/1750-1172-8-168] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2013] [Accepted: 10/11/2013] [Indexed: 01/04/2023] Open
Abstract
Hypopigmentation disorders that are associated with immunodeficiency feature both partial albinism of hair, skin and eyes together with leukocyte defects. These disorders include Chediak Higashi (CHS), Griscelli (GS), Hermansky-Pudlak (HPS) and MAPBP-interacting protein deficiency syndromes. These are heterogeneous autosomal recessive conditions in which the causal genes encode proteins with specific roles in the biogenesis, function and trafficking of secretory lysosomes. In certain specialized cells, these organelles serve as a storage compartment. Impaired secretion of specific effector proteins from that intracellular compartment affects biological activities. In particular, these intracellular granules are essential constituents of melanocytes, platelets, granulocytes, cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells. Thus, abnormalities affect pigmentation, primary hemostasis, blood cell counts and lymphocyte cytotoxic activity against microbial pathogens. Among eight genetically distinct types of HPS, only type 2 is characterized by immunodeficiency. Recently, a new subtype, HPS9, was defined in patients presenting with immunodeficiency and oculocutaneous albinism, associated with mutations in the pallidin-encoding gene, PLDN.Hypopigmentation together with recurrent childhood bacterial or viral infections suggests syndromic albinism. T and NK cell cytotoxicity are generally impaired in patients with these disorders. Specific clinical and biochemical phenotypes can allow differential diagnoses among these disorders before molecular testing. Ocular symptoms, including nystagmus, that are usually evident at birth, are common in patients with HPS2 or CHS. Albinism with short stature is unique to MAPBP-interacting protein (MAPBPIP) deficiency, while hemophagocytic lymphohistiocytosis (HLH) mainly suggests a diagnosis of CHS or GS type 2 (GS2). Neurological disease is a long-term complication of CHS, but is uncommon in other syndromic albinism. Chronic neutropenia is a feature of HPS2 and MAPBPIP-deficiency syndrome, whereas it is usually transient in CHS and GS2. In every patient, an accurate diagnosis is required for prompt and appropriate treatment, particularly in patients who develop HLH or in whom bone marrow transplant is required. This review describes the molecular and pathogenetic mechanisms of these diseases, focusing on clinical and biochemical aspects that allow early differential diagnosis.
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Affiliation(s)
- Laura Dotta
- Department of Experimental and Clinical Sciences, Institute of Molecular Medicine “Angelo Nocivelli”, University of Brescia, Brescia, Italy
| | - Silvia Parolini
- Department of Molecular and Translational Medicine, University of Brescia, Brescia 25123, Italy
| | - Alberto Prandini
- Department of Experimental and Clinical Sciences, Institute of Molecular Medicine “Angelo Nocivelli”, University of Brescia, Brescia, Italy
| | - Giovanna Tabellini
- Department of Molecular and Translational Medicine, University of Brescia, Brescia 25123, Italy
| | - Maddalena Antolini
- Department of Experimental and Clinical Sciences, Institute of Molecular Medicine “Angelo Nocivelli”, University of Brescia, Brescia, Italy
| | - Stephen F Kingsmore
- Center for Pediatric Genomic Medicine, Children’s Mercy Hospital, Kansas City, MO 64108, USA
| | - Raffaele Badolato
- Department of Experimental and Clinical Sciences, Institute of Molecular Medicine “Angelo Nocivelli”, University of Brescia, Brescia, Italy
- Istituto di Medicina Molecolare “Angelo Nocivelli”, Universita' di Brescia, c/o Spedali Civili, Brescia 25123, Italy
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Germline Mutation in EXPH5 Implicates the Rab27B Effector Protein Slac2-b in Inherited Skin Fragility. Am J Hum Genet 2012. [PMID: 23176819 DOI: 10.1016/j.ajhg.2012.10.012] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The Rab GTPase Rab27B and one of its effector proteins, Slac2-b (also known as EXPH5, exophilin-5), have putative roles in intracellular vesicle trafficking but their relevance to human disease is not known. By using whole-exome sequencing, we identified a homozygous frameshift mutation in EXPH5 in three siblings with inherited skin fragility born to consanguineous Iraqi parents. All three individuals harbor the mutation c.5786delC (p.Pro1929Leufs(∗)8) in EXPH5, which truncates the 1,989 amino acid Slac2-b protein by 52 residues. The clinical features comprised generalized scale-crusts and occasional blisters, mostly induced by trauma, as well as mild diffuse pigmentary mottling on the trunk and proximal limbs. There was no increased bleeding tendency, no neurologic abnormalities, and no increased incidence of infection. Analysis of an affected person's skin showed loss of Slac2-b immunostaining (C-terminal antibody), disruption of keratinocyte adhesion within the lower epidermis, and an increased number of perinuclear vesicles. A role for Slac2-b in keratinocyte biology was supported by findings of cytoskeletal disruption (mainly keratin intermediate filaments) and decreased keratinocyte adhesion in both keratinocytes from an affected subject and after shRNA knockdown of Slac2-b in normal keratinocytes. Slac2-b was also shown to colocalize with Rab27B and β4 integrin to early adhesion initiation sites in spreading normal keratinocytes. Collectively, our findings identify an unexpected role for Slac2-b in inherited skin fragility and expand the clinical spectrum of human disorders of GTPase effector proteins.
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Sahana M, Sacchidanand S, Hiremagalore R, Asha G. Silvery grey hair: clue to diagnose immunodeficiency. Int J Trichology 2012. [PMID: 23180914 PMCID: PMC3500078 DOI: 10.4103/0974-7753.96910] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Silvery hair is a common presentation of rare group of autosomal recessive disorders called Silvery hair syndromes including Griscelli syndrome (GS), Chediak-Higashi syndrome, and Elejalde syndrome. GS is characterized by a silvery grey sheen to hair, large clumped melanosomes in hair shaft, partial albinism, and variable cellular immunodeficiency. We report two cases of GS with classical clinical features and confirmatory findings by microscopic skin and hair examination.
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Affiliation(s)
- Ms Sahana
- Department of Dermatology, STD and Leprosy, Bangalore Medical College and Research Institute, Bangalore, Karnataka, India
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Bed'hom B, Vaez M, Coville JL, Gourichon D, Chastel O, Follett S, Burke T, Minvielle F. The lavender plumage colour in Japanese quail is associated with a complex mutation in the region of MLPH that is related to differences in growth, feed consumption and body temperature. BMC Genomics 2012; 13:442. [PMID: 22937744 PMCID: PMC3484014 DOI: 10.1186/1471-2164-13-442] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Accepted: 08/25/2012] [Indexed: 01/08/2023] Open
Abstract
Background The lavender phenotype in quail is a dilution of both eumelanin and phaeomelanin in feathers that produces a blue-grey colour on a wild-type feather pattern background. It has been previously demonstrated by intergeneric hybridization that the lavender mutation in quail is homologous to the same phenotype in chicken, which is caused by a single base-pair change in exon 1 of MLPH. Results In this study, we have shown that a mutation of MLPH is also associated with feather colour dilution in quail, but that the mutational event is extremely different. In this species, the lavender phenotype is associated with a non-lethal complex mutation involving three consecutive overlapping chromosomal changes (two inversions and one deletion) that have consequences on the genomic organization of four genes (MLPH and the neighbouring PRLH, RAB17 and LRRFIP1). The deletion of PRLH has no effect on the level of circulating prolactin. Lavender birds have lighter body weight, lower body temperature and increased feed consumption and residual feed intake than wild-type plumage quail, indicating that this complex mutation is affecting the metabolism and the regulation of homeothermy. Conclusions An extensive overlapping chromosome rearrangement was associated with a non-pathological Mendelian trait and minor, non deleterious effects in the lavender Japanese quail which is a natural knockout for PRLH.
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Affiliation(s)
- Bertrand Bed'hom
- UMR 1313 INRA/AgroParisTech, Génétique Animale et Biologie Intégrative GABI, 78352 Jouy-en-Josas, France
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41
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Sitaram A, Marks MS. Mechanisms of protein delivery to melanosomes in pigment cells. Physiology (Bethesda) 2012; 27:85-99. [PMID: 22505665 DOI: 10.1152/physiol.00043.2011] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Vertebrate pigment cells in the eye and skin are useful models for cell types that use specialized endosomal trafficking pathways to partition cargo proteins to unique lysosome-related organelles such as melanosomes. This review describes current models of protein trafficking required for melanosome biogenesis in mammalian melanocytes.
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Affiliation(s)
- Anand Sitaram
- Cell and Molecular Biology Graduate Group, Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Yoshida-Amano Y, Hachiya A, Ohuchi A, Kobinger GP, Kitahara T, Takema Y, Fukuda M. Essential role of RAB27A in determining constitutive human skin color. PLoS One 2012; 7:e41160. [PMID: 22844437 PMCID: PMC3402535 DOI: 10.1371/journal.pone.0041160] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Accepted: 06/18/2012] [Indexed: 11/18/2022] Open
Abstract
Human skin color is predominantly determined by melanin produced in melanosomes within melanocytes and subsequently distributed to keratinocytes. There are many studies that have proposed mechanisms underlying ethnic skin color variations, whereas the processes involved from melanin synthesis in melanocytes to the transfer of melanosomes to keratinocytes are common among humans. Apart from the activities in the melanogenic rate-limiting enzyme, tyrosinase, in melanocytes and the amounts and distribution patterns of melanosomes in keratinocytes, the abilities of the actin-associated factors in charge of melanosome transport within melanocytes also regulate pigmentation. Mutations in genes encoding melanosome transport-related molecules, such as MYO5A, RAB27A and SLAC-2A, have been reported to cause a human pigmentary disease known as Griscelli syndrome, which is associated with diluted skin and hair color. Thus we hypothesized that process might play a role in modulating skin color variations. To address that hypothesis, the correlations of expression of RAB27A and its specific effector, SLAC2-A, to melanogenic ability were evaluated in comparison with tyrosinase, using human melanocytes derived from 19 individuals of varying skin types. Following the finding of the highest correlation in RAB27A expression to the melanogenic ability, darkly-pigmented melanocytes with significantly higher RAB27A expression were found to transfer significantly more melanosomes to keratinocytes than lightly-pigmented melanocytes in co-culture and in human skin substitutes (HSSs) in vivo, resulting in darker skin color in concert with the difference observed in African-descent and Caucasian skins. Additionally, RAB27A knockdown by a lentivirus-derived shRNA in melanocytes concomitantly demonstrated a significantly reduced number of transferred melanosomes to keratinocytes in co-culture and a significantly diminished epidermal melanin content skin color intensity (ΔL* = 4.4) in the HSSs. These data reveal the intrinsically essential role of RAB27A in human ethnic skin color determination and provide new insights for the fundamental understanding of regulatory mechanisms underlying skin pigmentation.
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Affiliation(s)
| | - Akira Hachiya
- Biological Science Laboratories, Kao Corporation, Haga, Tochigi, Japan
- * E-mail:
| | - Atsushi Ohuchi
- Biological Science Laboratories, Kao Corporation, Haga, Tochigi, Japan
| | - Gary P. Kobinger
- Special Pathogens Program, National Microbiology Laboratory, Department of Medical Microbiology, Public Health Agency of Canada, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Takashi Kitahara
- Biological Science Laboratories, Kao Corporation, Haga, Tochigi, Japan
| | - Yoshinori Takema
- Research and Development Global, Kao Corporation, Sumida-ku, Tokyo, Japan
| | - Mitsunori Fukuda
- Laboratory of Membrane Trafficking Mechanisms, Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi, Japan
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43
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Westbroek W, Klar A, Cullinane AR, Ziegler SG, Hurvitz H, Ganem A, Wilson K, Dorward H, Huizing M, Tamimi H, Vainshtein I, Berkun Y, Lavie M, Gahl WA, Anikster Y. Cellular and clinical report of new Griscelli syndrome type III cases. Pigment Cell Melanoma Res 2011; 25:47-56. [PMID: 21883982 DOI: 10.1111/j.1755-148x.2011.00901.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The RAB27A/Melanophilin/Myosin-5a tripartite protein complex is required for capturing mature melanosomes in the peripheral actin network of melanocytes for subsequent transfer to keratinocytes. Mutations in any one member of this tripartite complex cause three forms of Griscelli syndrome (GS), each with distinct clinical features but with a similar cellular phenotype. To date, only one case of GS type III (GSIII), caused by mutations in the Melanophilin (MLPH) gene, has been reported. Here, we report seven new cases of GSIII in three distinct Arab pedigrees. All affected individuals carried a homozygous missense mutation (c.102C>T; p.R35W), located in the conserved Slp homology domain of MLPH, and had hypomelanosis of the skin and hair. We report the first cellular studies on GSIII melanocytes, which demonstrated that MLPH(R35W) causes perinuclear aggregation of melanosomes in melanocytes, typical for GS. Additionally, co-immunoprecipitation assays showed that MLPH(R35W) lost its interaction with RAB27A, indicating pathogenicity of the R35W mutation.
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Affiliation(s)
- Wendy Westbroek
- Section on Human Biochemical Genetics, Medical Genetics Branch, National Human Genome Research Institute, NIH, Bethesda MD, USA.
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44
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Schumacher FR, Berndt SI, Siddiq A, Jacobs KB, Wang Z, Lindstrom S, Stevens VL, Chen C, Mondul AM, Travis RC, Stram DO, Eeles RA, Easton DF, Giles G, Hopper JL, Neal DE, Hamdy FC, Donovan JL, Muir K, Al Olama AA, Kote-Jarai Z, Guy M, Severi G, Grönberg H, Isaacs WB, Karlsson R, Wiklund F, Xu J, Allen NE, Andriole GL, Barricarte A, Boeing H, Bas Bueno-de-Mesquita H, Crawford ED, Diver WR, Gonzalez CA, Gaziano JM, Giovannucci EL, Johansson M, Le Marchand L, Ma J, Sieri S, Stattin P, Stampfer MJ, Tjonneland A, Vineis P, Virtamo J, Vogel U, Weinstein SJ, Yeager M, Thun MJ, Kolonel LN, Henderson BE, Albanes D, Hayes RB, Spencer Feigelson H, Riboli E, Hunter DJ, Chanock SJ, Haiman CA, Kraft P. Genome-wide association study identifies new prostate cancer susceptibility loci. Hum Mol Genet 2011; 20:3867-75. [PMID: 21743057 PMCID: PMC3168287 DOI: 10.1093/hmg/ddr295] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2011] [Revised: 06/18/2011] [Accepted: 06/27/2011] [Indexed: 12/18/2022] Open
Abstract
Prostate cancer (PrCa) is the most common non-skin cancer diagnosed among males in developed countries and the second leading cause of cancer mortality, yet little is known regarding its etiology and factors that influence clinical outcome. Genome-wide association studies (GWAS) of PrCa have identified at least 30 distinct loci associated with small differences in risk. We conducted a GWAS in 2782 advanced PrCa cases (Gleason grade ≥ 8 or tumor stage C/D) and 4458 controls with 571 243 single nucleotide polymorphisms (SNPs). Based on in silico replication of 4679 SNPs (Stage 1, P < 0.02) in two published GWAS with 7358 PrCa cases and 6732 controls, we identified a new susceptibility locus associated with overall PrCa risk at 2q37.3 (rs2292884, P= 4.3 × 10(-8)). We also confirmed a locus suggested by an earlier GWAS at 12q13 (rs902774, P= 8.6 × 10(-9)). The estimated per-allele odds ratios for these loci (1.14 for rs2292884 and 1.17 for rs902774) did not differ between advanced and non-advanced PrCa (case-only test for heterogeneity P= 0.72 and P= 0.61, respectively). Further studies will be needed to assess whether these or other loci are differentially associated with PrCa subtypes.
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Affiliation(s)
- Fredrick R. Schumacher
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Sonja I. Berndt
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA
| | | | - Kevin B. Jacobs
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA
- Core Genotyping Facility, SAIC-Frederick Inc., NCI-Frederick, Frederick, MD, USA
- Bioinformed Consulting Services, Gaithersburg, MD, USA
| | - Zhaoming Wang
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA
- Core Genotyping Facility, SAIC-Frederick Inc., NCI-Frederick, Frederick, MD, USA
| | - Sara Lindstrom
- Program in Molecular and Genetic Epidemiology
- Department of Epidemiology and
| | | | - Constance Chen
- Program in Molecular and Genetic Epidemiology
- Department of Epidemiology and
| | - Alison M. Mondul
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA
| | - Ruth C. Travis
- Cancer Epidemiology Unit
- Nuffield Department of Clinical Medicine and
| | - Daniel O. Stram
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | | | - Douglas F. Easton
- Centre for Cancer Genetic Epidemiology
- Department of Public Health
- Department of Primary Care and
- Department of Oncology, University of Cambridge, Cambridge, UK
| | - Graham Giles
- Cancer Epidemiology Centre, Cancer Council Victoria, Victoria, Australia
| | - John L. Hopper
- Centre for Molecular, Environmental, Genetic and Analytic (MEGA) Epidemiology, Melbourne School of Population Health, The University of Melbourne, Melbourne, Australia
| | - David E. Neal
- Department of Oncology, University of Cambridge, Cambridge, UK
| | - Freddie C. Hamdy
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, UK
| | - Jenny L. Donovan
- School of Social and Community Medicine, University of Bristol, Bristol, UK
| | - Kenneth Muir
- Health Sciences Research Institute, University of Warwick, Coventry, UK
| | - Ali Amin Al Olama
- Centre for Cancer Genetic Epidemiology
- Department of Public Health
- Department of Primary Care and
| | | | - Michelle Guy
- Oncogenetics Team, The Institute of Cancer Research, Sutton, UK
| | - Gianluca Severi
- Cancer Epidemiology Centre, Cancer Council Victoria, Victoria, Australia
| | - Henrik Grönberg
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - William B. Isaacs
- The Brady Urological Institute, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Robert Karlsson
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Fredrik Wiklund
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Jianfeng Xu
- Centers for Cancer Genomics and Center for Human Genomics, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Naomi E. Allen
- Cancer Epidemiology Unit
- Nuffield Department of Clinical Medicine and
| | - Gerald L. Andriole
- Division of Urologic Surgery, Washington University School of Medicine, St Louis, MO, USA
| | | | - Heiner Boeing
- Department of Epidemiology, Deutsches Institut für Ernährungsforschung, Potsdam-Rehbrücke, Germany
| | | | | | - W. Ryan Diver
- Epidemiology Research Program, American Cancer Society, Atlanta, GA, USA
| | - Carlos A. Gonzalez
- Unit of Nutrition, Environment and Cancer, Catalan Institute of Oncology (ICO-IDIBELL-RETICC RD06/0020), L'Hospitalet de Llobregat, Barcelona, Spain
| | - J. Michael Gaziano
- Division of Aging and
- Massachusetts Veterans Epidemiology Research and Information Center/VA Cooperative Studies Programs, VA Boston Healthcare System, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Edward L. Giovannucci
- Department of Epidemiology and
- Department of Nutrition, Harvard School of Public Health, Boston 02115, MA, USA
| | - Mattias Johansson
- International Agency for Research on Cancer (IARC), Lyon, France
- Department of Surgical and Perioperative Sciences, Urology and Andrology, Umeå University, Umeå, Sweden
| | - Loic Le Marchand
- Cancer Research Center of Hawaii, University of Hawaii, Honolulu, HI, USA
| | - Jing Ma
- Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
- Channing Laboratory, Boston, MA, USA
| | - Sabina Sieri
- Nutritional Epidemiology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Pär Stattin
- Department of Surgical and Perioperative Sciences, Urology and Andrology, Umeå University, Umeå, Sweden
| | - Meir J. Stampfer
- Department of Epidemiology and
- Department of Nutrition, Harvard School of Public Health, Boston 02115, MA, USA
- Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
- Channing Laboratory, Boston, MA, USA
| | - Anne Tjonneland
- Institute of Cancer Epidemiology, Danish Cancer Society, Copenhagen, Denmark
| | - Paolo Vineis
- MRC-HPA Centre for Environment and Health, School of Public Health, Imperial College London, London, UK
| | - Jarmo Virtamo
- Department of Chronic Disease Prevention, National Institute for Health and Welfare, Helsinki, Finland
| | - Ulla Vogel
- National Research Centre for the Working Environment, Copenhagen, Denmark
- National Food Institute, Technical University of Denmark, Soborg, Denmark
| | - Stephanie J. Weinstein
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA
| | - Meredith Yeager
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA
| | - Michael J. Thun
- Epidemiology Research Program, American Cancer Society, Atlanta, GA, USA
| | | | - Brian E. Henderson
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Demetrius Albanes
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA
| | - Richard B. Hayes
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA
- Division of Epidemiology, Department of Environmental Medicine, New York University Langone Medical Center, NYU Cancer Institute, New York, NY, USA and
| | | | - Elio Riboli
- Department of Epidemiology and Biostatistics and
| | - David J. Hunter
- Program in Molecular and Genetic Epidemiology
- Department of Epidemiology and
| | - Stephen J. Chanock
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA
| | - Christopher A. Haiman
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Peter Kraft
- Program in Molecular and Genetic Epidemiology
- Department of Epidemiology and
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45
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Rutz-Mendicino MM, Snella EM, Jens JK, Gandolfi B, Carlson SA, Kuehn MH, McLellan GJ, Ellinwood NM. Removal of potentially confounding phenotypes from a Siamese-derived feline glaucoma breeding colony. Comp Med 2011; 61:251-257. [PMID: 21819695 PMCID: PMC3123758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2010] [Revised: 10/11/2010] [Accepted: 12/06/2010] [Indexed: 05/31/2023]
Abstract
Feline breeding colonies face genetic constraints involving founder effects. A Siamese-founded colony used to study primary congenital glaucoma displayed coat colors additional to the Siamese coat. Genes affecting pigment can exhibit pleiotropy on ocular development and function. To remove potentially confounding phenotypes from our colony, we documented the source and frequency of the Siamese allele at the gene for tyrosinase (TYR), the dilution allele at melanophilin (MLPH), and the brown allele at tyrosinase-related protein 1 (TYRP1). We used PCR-RFLP diagnostics to genotype cats in our colony for the published alleles. A commercially acquired phenotypically normal tom was the source of the dilute allele. A founding Siamese queen was the source of the brown allele. Founders also were blood-typed and screened for disease-associated alleles segregating in Siamese cats at 3 loci (ASB, GLB1, and CEP290). Siamese founders were normal at all loci except ASB, at which both animals carried the hypomorpic allele. Current stock is being managed to limit production of glaucomatous cats with brown, dilute, or Siamese phenotypes or homozygosity for the ASB hypomorphic allele. Genotyping will aid in the elimination of these alleles. The clinical effect of these phenotypes and alleles on the glaucoma phenotype is uncertain, but their elimination will remove potentially confounding effects. In conclusion, when founding a colony, stock should be selected or screened to limit potentially confounding phenotypes. When studying the immune, nervous, and visual systems, screening stock for alleles known to be associated with coat color may be warranted.
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Affiliation(s)
- Michelle M Rutz-Mendicino
- Departments of Animal Science and the Center for Integrated Animal Genomics
- Biomedical Sciences, Iowa State University, Ames, Iowa
| | - Elizabeth M Snella
- Departments of Animal Science and the Center for Integrated Animal Genomics
| | - Jackie K Jens
- Departments of Animal Science and the Center for Integrated Animal Genomics
| | - Barbara Gandolfi
- Department of Population Health and Reproduction, University of California, Davis, Davis, California
| | | | - Markus H Kuehn
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa
| | - Gillian J McLellan
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, Wisconsin
| | - N Matthew Ellinwood
- Departments of Animal Science and the Center for Integrated Animal Genomics
- Veterinary Clinical Sciences, Iowa State University, Ames, Iowa
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46
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Hartman MA, Finan D, Sivaramakrishnan S, Spudich JA. Principles of unconventional myosin function and targeting. Annu Rev Cell Dev Biol 2011; 27:133-55. [PMID: 21639800 DOI: 10.1146/annurev-cellbio-100809-151502] [Citation(s) in RCA: 123] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Unconventional myosins are a superfamily of actin-based motors implicated in diverse cellular processes. In recent years, much progress has been made in describing their biophysical properties, and headway has been made into analyzing their cellular functions. Here, we focus on the principles that guide in vivo motor function and targeting to specific cellular locations. Rather than describe each motor comprehensively, we outline the major themes that emerge from research across the superfamily and use specific examples to illustrate each. In presenting the data in this format, we seek to identify open questions in each field as well as to point out commonalities between them. To advance our understanding of myosins' roles in vivo, clearly we must identify their cellular cargoes and the protein complexes that regulate motor attachment to fully appreciate their functions on the cellular and developmental levels.
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Affiliation(s)
- M Amanda Hartman
- Department of Biochemistry, Stanford University, Stanford, California 94305, USA
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Congenital neutropenia: diagnosis, molecular bases and patient management. Orphanet J Rare Dis 2011; 6:26. [PMID: 21595885 PMCID: PMC3127744 DOI: 10.1186/1750-1172-6-26] [Citation(s) in RCA: 133] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2010] [Accepted: 05/19/2011] [Indexed: 12/27/2022] Open
Abstract
The term congenital neutropenia encompasses a family of neutropenic disorders, both permanent and intermittent, severe (<0.5 G/l) or mild (between 0.5-1.5 G/l), which may also affect other organ systems such as the pancreas, central nervous system, heart, muscle and skin. Neutropenia can lead to life-threatening pyogenic infections, acute gingivostomatitis and chronic parodontal disease, and each successive infection may leave permanent sequelae. The risk of infection is roughly inversely proportional to the circulating polymorphonuclear neutrophil count and is particularly high at counts below 0.2 G/l.When neutropenia is detected, an attempt should be made to establish the etiology, distinguishing between acquired forms (the most frequent, including post viral neutropenia and auto immune neutropenia) and congenital forms that may either be isolated or part of a complex genetic disease.Except for ethnic neutropenia, which is a frequent but mild congenital form, probably with polygenic inheritance, all other forms of congenital neutropenia are extremely rare and have monogenic inheritance, which may be X-linked or autosomal, recessive or dominant.About half the forms of congenital neutropenia with no extra-hematopoietic manifestations and normal adaptive immunity are due to neutrophil elastase (ELANE) mutations. Some patients have severe permanent neutropenia and frequent infections early in life, while others have mild intermittent neutropenia.Congenital neutropenia may also be associated with a wide range of organ dysfunctions, as for example in Shwachman-Diamond syndrome (associated with pancreatic insufficiency) and glycogen storage disease type Ib (associated with a glycogen storage syndrome). So far, the molecular bases of 12 neutropenic disorders have been identified.Treatment of severe chronic neutropenia should focus on prevention of infections. It includes antimicrobial prophylaxis, generally with trimethoprim-sulfamethoxazole, and also granulocyte-colony-stimulating factor (G-CSF). G-CSF has considerably improved these patients' outlook. It is usually well tolerated, but potential adverse effects include thrombocytopenia, glomerulonephritis, vasculitis and osteoporosis. Long-term treatment with G-CSF, especially at high doses, augments the spontaneous risk of leukemia in patients with congenital neutropenia.
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48
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Mizuno K, Ramalho JS, Izumi T. Exophilin8 transiently clusters insulin granules at the actin-rich cell cortex prior to exocytosis. Mol Biol Cell 2011; 22:1716-26. [PMID: 21441305 PMCID: PMC3093323 DOI: 10.1091/mbc.e10-05-0404] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2010] [Revised: 02/09/2011] [Accepted: 03/11/2011] [Indexed: 12/16/2022] Open
Abstract
Exophilin8/MyRIP/Slac2-c is an effector protein of the small GTPase Rab27a and is specifically localized on retinal melanosomes and secretory granules. We investigated the role of exophilin8 in insulin granule trafficking. Exogenous expression of exophilin8 in pancreatic β cells or their cell line, MIN6, polarized (exophilin8-positive) insulin granules at the cell corners, where both cortical actin and the microtubule plus-end-binding protein, EB1, were present. Mutation analyses indicated that the ability of exophilin8 to act as a linker between Rab27a and myosin Va is essential for its granule-clustering activity. Moreover, exophilin8 and exophilin8-associated insulin granules were markedly stable and immobile. Total internal reflection fluorescence microscopy indicated that exophilin8 restricts the motion of insulin granules at a region deeper than that where another Rab27a effector, granuphilin, accumulates docked granules directly attached to the plasma membrane. However, the exophilin8-induced immobility of insulin granules was eliminated upon secretagogue stimulation and did not inhibit evoked exocytosis. Furthermore, exophilin8 depletion prevents insulin granules from being transported close to the plasma membrane and inhibits their fusion. These findings indicate that exophilin8 transiently traps insulin granules into the cortical actin network close to the microtubule plus-ends and supplies them for release during the stimulation.
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Affiliation(s)
- Kouichi Mizuno
- Laboratory of Molecular Endocrinology and Metabolism, Department of Molecular Medicine, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi 371–8512, Japan
| | - José S. Ramalho
- CEDOC, Faculty of Medical Sciences, NOVA University, 1169–056 Lisbon, Portugal
| | - Tetsuro Izumi
- Laboratory of Molecular Endocrinology and Metabolism, Department of Molecular Medicine, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi 371–8512, Japan
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49
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Gholam C, Grigoriadou S, Gilmour KC, Gaspar HB. Familial haemophagocytic lymphohistiocytosis: advances in the genetic basis, diagnosis and management. Clin Exp Immunol 2011; 163:271-83. [PMID: 21303357 DOI: 10.1111/j.1365-2249.2010.04302.x] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Familial haemophagocytic lymphohistiocytosis (FHL) is a rare autosomal recessive disorder of immune dysregulation associated with uncontrolled T cell and macrophage activation and hypercytokinaemia. The incidence of FHL is 0·12/100·000 children born per year, with a male to female ratio of 1:1. The disease is classified into six different types based on genetic linkage analysis and chromosomal localization; five specific genetic defects have been identified, which account for approximately 90% of all patients. Type 1 is due to an as yet unidentified gene defect located on chromosome nine. Type 2 is caused by mutations in the perforin (PRF1) gene, type 3 by mutations in the Munc-13-4 (UNC13D) gene, type 4 by mutations in the syntaxin 11 (STX11) gene and the recently described type 5 due to mutations in the gene encoding syntaxin binding protein 2 (STXBP-2). The incidence of the five types varies in different ethnic groups. The most common presenting features are pyrexia of unknown origin, pronounced hepatosplenomegaly and cytopenias. Neurological features tend to present later and are associated with poor prognosis. Absent or decreased lymphocyte cytotoxicity is the cellular hallmark of FHL. Biochemical features such as hyperferritinaemia, hypertriglyceridaemia and hypofibrinogenaemia are usually present, along with high levels of soluble interleukin 2 receptor in the blood and cerebrospinal fluid. Bone marrow aspirate may demonstrate the characteristic haemophagocytes, but initially is non-diagnostic in two-thirds of patients. Established international clinical, haematological and biochemical criteria now facilitate accurate clinical diagnosis. The disease is fatal unless a haematopoietic stem cell transplant (HSCT) is performed. The introduction of HSCT has dramatically improved the prognosis of the disease. However, the mortality of the disease is still significantly high and a number of challenges remain to be addressed. Active disease at the time of the transplant is the major significant poor prognostic factor. Delayed diagnosis, after irreversible organ damage has occurred, especially neurological damage, disease reoccurrence and pre-transplant mortality, remain a concern.
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Affiliation(s)
- C Gholam
- Department of Dermatology, Great Ormond Street Hospital NHS Trust, London, UK
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Kondo T, Hearing VJ. Update on the regulation of mammalian melanocyte function and skin pigmentation. EXPERT REVIEW OF DERMATOLOGY 2011; 6:97-108. [PMID: 21572549 PMCID: PMC3093193 DOI: 10.1586/edm.10.70] [Citation(s) in RCA: 146] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Melanogenesis is the unique process of producing pigmented biopolymers that are sequestered within melanosomes, which provides color to the skin, hair and eyes of animals and, in the case of human skin, also protects the underlying tissues from UV damage. We review the current understanding of melanogenesis, focusing on factors important to the biochemistry of pigment synthesis, the biogenesis of melanosomes, signaling pathways and factors that regulate melanogenesis, intramelanosomal pH, transport and transfer of melanosomes, and pigmentary disorders related to the dysfunction of melanosome-related proteins. Although it has been known for some time that many of the factors that affect melanogenesis are derived from keratinocytes, fibroblasts, endothelial cells, hormones, inflammatory cells and nerves, a number of new factors that are involved in that regulation have recently been reported, such as factors that regulate melanosome pH and ion transport.
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Affiliation(s)
- Taisuke Kondo
- Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Vincent J Hearing
- Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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