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Kahani SM, Saray AR, Kahaei MS, Dehghani A, Mohammadi P, Garshasbi M. A novel deletion in the BLOC1S6 Gene Associated with Hermansky-Pudlak syndrome type 9 (HPS-9). BMC Genomics 2024; 25:805. [PMID: 39187771 PMCID: PMC11348666 DOI: 10.1186/s12864-024-10478-w] [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: 12/26/2023] [Accepted: 05/29/2024] [Indexed: 08/28/2024] Open
Abstract
BACKGROUND Hermansky-Pudlak Syndrome (HPS), a rare autosomal recessive disorder, is characterized by oculocutaneous albinism, bleeding diathesis, and sometimes severe lung problems and inflammatory bowel disease. Symptoms include skin and hair pigmentation variations, along with visual impairments. Variants in eleven genes encoding protein complexes essential for membrane trafficking and intracellular endosomal transport pathways underlie various recognized HPS subtypes. This study focuses on HPS-9, a subtype of Hermansky-Pudlak Syndrome caused by a variant in the BLOC1S6 gene, which is a subunit of the BLOC1 complex. In this study, a novel Copy Number Variation (CNV) in the aforementioned gene in an Iranian family is reported. The study aims to better understand the etiology of HPS-9 symptoms by identifying and confirming the variant and determining whether the gene is expressed despite the deletion. There have only been five reports of this syndrome in the literature thus far. Our novel CNV represents a significant contribution to understanding the genetic basis of HPS-9. RESULTS This study investigates a male patient presenting with albinism. Whole Exome Sequencing (WES) identified a homozygous deletion of approximately 350 bp using CNV analysis. The deletion affects the intronic region of the BLOC1S6 gene, causing uncertainties in defining the exact boundaries due to WES limitations. Primer walking and GAP-PCR techniques were used to define the deletion boundaries. Subsequent assessments of this variant across other family members helped identify homozygous affected members and heterozygous carriers. The absence of BLOC1S6 expression in the affected individual was confirmed through Real-time PCR experiments. These findings underscore the importance of understanding the implications for the patient's healthcare and potential therapeutic approaches. CONCLUSION This study introduces a case of Hermansky-Pudlak Syndrome Type 9 (HPS-9) caused by a homozygous deletion in the BLOC1S6 gene. We identified an approximately 7-kb deletion encompassing exon 1 and the intronic region of the gene. The absence of BLOC1S6 expression, confirmed via Real-time PCR, highlights the importance of studying the pathogenicity of the deletion and its impact on the patient's health. Our findings contribute to the sparse knowledge on HPS-9 and underscore the need for further exploration into the genetic causes of this rare disorder.
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Affiliation(s)
- Seyyed Mohammad Kahani
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
- PardisGene CO, Tehran, Iran
| | - Ali Rabbizadeh Saray
- Department of Medical Genetics and Molecular Medicine, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mir Salar Kahaei
- Department of Medical Genetics and Molecular Medicine, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Ali Dehghani
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Pouria Mohammadi
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
- PardisGene CO, Tehran, Iran
| | - Masoud Garshasbi
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
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Rachinger N, Mittag N, Böhme-Schäfer I, Xiang W, Kuphal S, Bosserhoff AK. Alpha-Synuclein and Its Role in Melanocytes. Cells 2022; 11:cells11132087. [PMID: 35805172 PMCID: PMC9265281 DOI: 10.3390/cells11132087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 06/10/2022] [Accepted: 06/29/2022] [Indexed: 12/04/2022] Open
Abstract
Pigmentation is an important process in skin physiology and skin diseases and presumably also plays a role in Parkinson’s disease (PD). In PD, alpha-Synuclein (aSyn) has been shown to be involved in the pigmentation of neurons. The presynaptic protein is intensively investigated for its pathological role in PD, but its physiological function remains unknown. We hypothesized that aSyn is both involved in melanocytic differentiation and melanosome trafficking processes. We detected a strong expression of aSyn in human epidermal melanocytes (NHEMs) and observed its regulation in melanocytic differentiation via the microphthalmia-associated transcription factor (MITF), a central regulator of differentiation. Moreover, we investigated its role in pigmentation by performing siRNA experiments but found no effect on the total melanin content. We discovered a localization of aSyn to melanosomes, and further analysis of aSyn knockdown revealed an important role in melanocytic morphology and a reduction in melanosome release. Additionally, we found a reduction of transferred melanosomes in co-culture experiments of melanocytes and keratinocytes but no complete inhibition of melanosome transmission. In summary, this study highlights a novel physiological role of aSyn in melanocytic morphology and its so far unknown function in the pigment secretion in melanocytes.
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Affiliation(s)
- Nicole Rachinger
- Institute of Biochemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany; (N.R.); (I.B.-S.); (S.K.)
| | - Nora Mittag
- Department of Dermatology and Allergy, University Hospital, LMU Munich, 80539 Munich, Germany;
| | - Ines Böhme-Schäfer
- Institute of Biochemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany; (N.R.); (I.B.-S.); (S.K.)
| | - Wei Xiang
- Department of Molecular Neurology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany;
| | - Silke Kuphal
- Institute of Biochemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany; (N.R.); (I.B.-S.); (S.K.)
| | - Anja K. Bosserhoff
- Institute of Biochemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany; (N.R.); (I.B.-S.); (S.K.)
- Correspondence:
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Bustos SO, Leal Santos N, Chammas R, Andrade LNDS. Secretory Autophagy Forges a Therapy Resistant Microenvironment in Melanoma. Cancers (Basel) 2022; 14:234. [PMID: 35008395 PMCID: PMC8749976 DOI: 10.3390/cancers14010234] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 12/22/2021] [Accepted: 12/28/2021] [Indexed: 12/12/2022] Open
Abstract
Melanoma is the most aggressive skin cancer characterized by high mutational burden and large heterogeneity. Cancer cells are surrounded by a complex environment, critical to tumor establishment and progression. Thus, tumor-associated stromal components can sustain tumor demands or impair cancer cell progression. One way to manage such processes is through the regulation of autophagy, both in stromal and tumor cells. Autophagy is a catabolic mechanism that provides nutrients and energy, and it eliminates damaged organelles by degradation and recycling of cellular elements. Besides this primary function, autophagy plays multiple roles in the tumor microenvironment capable of affecting cell fate. Evidence demonstrates the existence of novel branches in the autophagy system related to cytoplasmic constituent's secretion. Hence, autophagy-dependent secretion assembles a tangled network of signaling that potentially contributes to metabolism reprogramming, immune regulation, and tumor progression. Here, we summarize the current awareness regarding secretory autophagy and the intersection with exosome biogenesis and release in melanoma and their role in tumor resistance. In addition, we present and discuss data from public databases concerning autophagy and exosome-related genes as important mediators of melanoma behavior. Finally, we will present the main challenges in the field and strategies to translate most of the pre-clinical findings to clinical practice.
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Affiliation(s)
- Silvina Odete Bustos
- Center for Translational Research in Oncology (LIM24), Instituto do Câncer do Estado de São Paulo, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Sao Paulo 01246-000, Brazil; (N.L.S.); (R.C.)
| | | | | | - Luciana Nogueira de Sousa Andrade
- Center for Translational Research in Oncology (LIM24), Instituto do Câncer do Estado de São Paulo, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Sao Paulo 01246-000, Brazil; (N.L.S.); (R.C.)
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Reduced O-GlcNAcylation of SNAP-23 promotes cisplatin resistance by inducing exosome secretion in ovarian cancer. Cell Death Discov 2021; 7:112. [PMID: 34001861 PMCID: PMC8128872 DOI: 10.1038/s41420-021-00489-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 03/23/2021] [Accepted: 04/19/2021] [Indexed: 02/06/2023] Open
Abstract
Exosomes have been associated with chemoresistance in various cancers, but such a role in ovarian cancer is not yet clear. Here, using in vitro cell-based and in vivo mouse model experiments, we show that downregulation of O-GlcNAcylation, a key post-translational protein modification, promotes exosome secretion. This increases exosome-mediated efflux of cisplatin from cancer cells resulting in chemoresistance. Mechanistically, our data indicate that downregulation of O-GlcNAclation transferase (OGT) reduces O-GlcNAclation of SNAP-23. Notably, O-GlcNAcylation of SNAP-23 is vital for regulating exosome release in ovarian cancer cells. Reduced O-GlcNAclation of SNAP-23 subsequently promotes the formation of soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex consisting of SNAP-23, VAMP8, and Stx4 proteins. This enhances exosome release causing chemoresistance by increasing the efflux of intracellular cisplatin.
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Abstract
Melanin pigments are responsible for human skin and hair color, and they protect the body from harmful ultraviolet light. The black and brown melanin pigments are synthesized in specialized lysosome-related organelles called melanosomes in melanocytes. Mature melanosomes are transported within melanocytes and transferred to adjacent keratinocytes, which constitute the principal part of human skin. The melanosomes are then deposited inside the keratinocytes and darken the skin (a process called tanning). Owing to their dark color, melanosomes can be seen easily with an ordinary light microscope, and melanosome research dates back approximately 150 years; since then, biochemical studies aimed at isolating and purifying melanosomes have been conducted. Moreover, in the last two decades, hundreds of molecules involved in regulating melanosomal functions have been identified by analyses of the genes of coat-color mutant animals and patients with genetic diseases characterized by pigment abnormalities, such as hypopigmentation. In recent years, dynamic analyses by more precise microscopic observations have revealed specific functions of a variety of molecules involved in melanogenesis. This review article focuses on the latest findings with regard to the steps (or mechanisms) involved in melanosome formation and transport of mature melanosomes within epidermal melanocytes. Finally, we will touch on current topics in melanosome research, particularly on the "melanosome transfer" and "post-transfer" steps, and discuss future directions in pigment research.
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Affiliation(s)
- Norihiko Ohbayashi
- Faculty of Medicine and Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba 305-8575, Japan
| | - Mitsunori Fukuda
- Laboratory of Membrane Trafficking Mechanisms, Department of Integrative Life Sciences, Graduate School of Life Sciences, Tohoku University, Miyagi 980-8578, Japan
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Lin L, Chen X, Zhou Q, Huang P, Jiang S, Wang H, Deng Y. Synaptic structure and alterations in the hippocampus in neonatal rats exposed to lipopolysaccharide. Neurosci Lett 2019; 709:134364. [PMID: 31288048 DOI: 10.1016/j.neulet.2019.134364] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 06/25/2019] [Accepted: 07/02/2019] [Indexed: 02/05/2023]
Abstract
Synaptic structure integrity plays a key role in learning and memory. Previous studies have shown that there is cognitive dysfunction in septic neonates in later life. In this study, intraperitoneal injection of lipopolysaccharide (LPS) in the developing rats was used as a sepsis model to determine whether hippocampal synapses would be affected. Expression of synaptophysin (Syn), synaptosomal associated protein of 25 kD (SNAP-25), and N-methyl d-aspartate receptor (NMDAR) in the hippocampus in septic brain were significantly reduced. Consistent with this, the number of dendritic spines associated with the pyramidal neurons in the CA1 region of hippocampus at 28d after LPS administration was decreased. Additionally, the number of synapse and synaptic vesicles were reduced and appeared swollen. The number of neurons in the CA1 and CA3 of hippocampus at 14, and 28d after LPS injection remained unchanged. Coupled with the above was upregulated expression of interleukin-1β (IL-1β), IL-1 receptor 1 (IL-R1), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and inducible nitric oxide synthase (iNOS) at 1-3d after LPS injection. IL-1β expression was specifically detected in activated microglia. The plasma corticosterone (CORT) concentration in the LPS treatment rats was increased; but the glucocorticoid receptor (GR) expression in the hippocampus was decreased. We conclude that LPS injection in neonatal rats can cause synaptic disruption in the hippocampus which may be attributed to inflammatory response due to excess production of proinflammatory cytokines e.g., IL-1β derived from activated microglia. The significance of increased plasma CORT concentration and decreased GR expression in the hippocampus is discussed.
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Affiliation(s)
- Lanfen Lin
- Department of Critical Care and Emergency, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, People's Republic of China
| | - Xuan Chen
- Department of Critical Care and Emergency, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, People's Republic of China; Shantou University Medical College (FCS), Shantou, 515063, People's Republic of China
| | - Qiuping Zhou
- Department of Critical Care and Emergency, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, People's Republic of China; South China University of Technology, Guangzhou, 510641, People's Republic of China
| | - Peixian Huang
- Department of Critical Care and Emergency, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, People's Republic of China; Shantou University Medical College (FCS), Shantou, 515063, People's Republic of China
| | - Shuqi Jiang
- Department of Critical Care and Emergency, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, People's Republic of China; South China University of Technology, Guangzhou, 510641, People's Republic of China
| | - Huifang Wang
- Department of Critical Care and Emergency, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, People's Republic of China; Southern Medical University, Guangzhou, 510515, People's Republic of China
| | - Yiyu Deng
- Department of Critical Care and Emergency, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, People's Republic of China.
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Okajima S, Hamamoto A, Asano M, Isogawa K, Ito H, Kato S, Hirata Y, Furuta K, Takemori H. Azepine derivative T4FAT, a new copper chelator, inhibits tyrosinase. Biochem Biophys Res Commun 2019; 509:209-215. [DOI: 10.1016/j.bbrc.2018.12.105] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 12/14/2018] [Indexed: 01/09/2023]
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