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Liu L, Wang Y, Zhang Z, Yu C, Chen J. Identification of a novel TSC1 gene variant in a patient with atypical vitiligo-like skin lesions: Unveiling the hidden tuberous sclerosis complex. Mol Genet Genomic Med 2024; 12:e2403. [PMID: 38439608 PMCID: PMC10912791 DOI: 10.1002/mgg3.2403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 01/04/2024] [Accepted: 02/05/2024] [Indexed: 03/06/2024] Open
Abstract
BACKGROUND Tuberous sclerosis complex (TSC), an autosomal-dominant disorder, is characterized by hamartomas affecting multiple organ systems. The underlying etiology of TSC is the pathogenic variations of the TSC1 or TSC2 genes. The phenotype variability of TSC could lead to missed diagnosis; therefore, the latest molecular diagnostic criteria for identifying a heterozygous pathogenic variant in either the TSC1 or TSC2 gene filled this gap. Furthermore, the pathogenicity of numerous variants remains unverified, potentially leading to misinterpretations of their functional consequences. METHODS In this study, a single patient presenting with atypical vitiligo-like skin lesions suspected to have TSC was enrolled. Targeted next-generation sequencing and Sanger sequencing were employed to identify a pathogenic variant. Additionally, a minigene splicing assay was conducted to assess the impact of TSC1 c.1030-2A>T, located in intron 10, on RNA splicing. RESULTS A novel TSC1: c.1030-2A>T heterozygosis variant was identified in intron 10. In vitro minigene assay revealed that the c.1030-2A>T variant caused exon 11 skipping, resulting in a frameshift in the absence of 112 base pairs of mature messenger RNA and premature termination after 174 base pairs (p.Ala344Glnfs*59). CONCLUSION The detection of this novel pathogenic TSC1 variant in the patient with atypical vitiligo-like skin lesions enrolled in our study ultimately resulted in the diagnosis of TSC. As a result, our study contributes to expanding the mutational spectrum of the TSC1 gene and refining the genotype-phenotype map of TSC.
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Affiliation(s)
- Linli Liu
- Department of DermatologyThe First Affiliated Hospital of Chongqing Medical UniversityChongqingChina
- Department of DermatologySuining Central HospitalSuiningSichuanChina
| | - Yanbo Wang
- Department of DermatologyLangzhong People's HospitalNanchongSichuanChina
| | - Zhengzhong Zhang
- Department of DermatologyAffiliated Hospital of North Sichuan Medical CollegeNanchongSichuanChina
| | - Chunshui Yu
- Department of DermatologySuining Central HospitalSuiningSichuanChina
| | - Jin Chen
- Department of DermatologyThe First Affiliated Hospital of Chongqing Medical UniversityChongqingChina
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2
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Shining Light on Autophagy in Skin Pigmentation and Pigmentary Disorders. Cells 2022; 11:cells11192999. [PMID: 36230960 PMCID: PMC9563738 DOI: 10.3390/cells11192999] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/13/2022] [Accepted: 09/23/2022] [Indexed: 01/18/2023] Open
Abstract
Autophagy is a vital process for cell survival and it preserves homeostasis by recycling or disassembling unnecessary or dysfunctional cellular constituents. Autophagy ameliorates skin integrity, regulating epidermal differentiation and constitutive pigmentation. It induces melanogenesis and contributes to skin color through melanosome turnover. Autophagy activity is involved in skin phenotypic plasticity and cell function maintenance and, if altered, it concurs to the onset and/or progression of hypopigmentary and hyperpigmentary disorders. Overexpression of autophagy exerts a protective role against the intrinsic metabolic stress occurring in vitiligo skin, while its dysfunction has been linked to the tuberous sclerosis complex hypopigmentation. Again, autophagy impairment reduces melanosome degradation by concurring to pigment accumulation characterizing senile lentigo and melasma. Here we provide an updated review that describes recent findings on the crucial role of autophagy in skin pigmentation, thus revealing the complex interplay among melanocyte biology, skin environment and autophagy. Hence, targeting this process may also represent a promising strategy for treating pigmentary disorders.
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3
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Sevilla A, Chéret J, Slominski RM, Slominski AT, Paus R. Revisiting the role of melatonin in human melanocyte physiology: A skin context perspective. J Pineal Res 2022; 72:e12790. [PMID: 35133682 PMCID: PMC8930624 DOI: 10.1111/jpi.12790] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 01/24/2022] [Accepted: 02/02/2022] [Indexed: 11/30/2022]
Abstract
The evolutionarily ancient methoxyindoleamine, melatonin, has long perplexed investigators by its versatility of functions and mechanisms of action, which include the regulation of vertebrate pigmentation. Although first discovered through its potent skin-lightening effects in amphibians, melatonin's role in human skin and hair follicle pigmentation and its impact on melanocyte physiology remain unclear. Synthesizing our limited current understanding of this role, we specifically examine its impact on melanogenesis, oxidative biology, mitochondrial function, melanocyte senescence, and pigmentation-related clock gene activity, with emphasis on human skin, yet without ignoring instructive pointers from nonhuman species. Given the strict dependence of melanocyte functions on the epithelial microenvironment, we underscore that melanocyte responses to melatonin are best interrogated in a physiological tissue context. Current evidence suggests that melatonin and some of its metabolites inhibit both, melanogenesis (via reducing tyrosinase activity) and melanocyte proliferation by stimulating melatonin membrane receptors (MT1, MT2). We discuss whether putative melanogenesis-inhibitory effects of melatonin may occur via activation of Nrf2-mediated PI3K/AKT signaling, estrogen receptor-mediated and/or melanocortin-1 receptor- and cAMP-dependent signaling, and/or via melatonin-regulated changes in peripheral clock genes that regulate human melanogenesis, namely Bmal1 and Per1. Melatonin and its metabolites also accumulate in melanocytes where they exert net cyto- and senescence-protective as well as antioxidative effects by operating as free radical scavengers, stimulating the synthesis and activity of ROS scavenging enzymes and other antioxidants, promoting DNA repair, and enhancing mitochondrial function. We argue that it is clinically and biologically important to definitively clarify whether melanocyte cell culture-based observations translate into melatonin-induced pigmentary changes in a physiological tissue context, that is, in human epidermis and hair follicles ex vivo, and are confirmed by clinical trial results. After defining major open questions in this field, we close by suggesting how to begin answering them in clinically relevant, currently available preclinical in situ research models.
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Affiliation(s)
- Alec Sevilla
- Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Jérémy Chéret
- Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Radomir M. Slominski
- Graduate Biomedical Sciences Program, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Andrzej T. Slominski
- Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Pathology Laboratory Service, Veteran Administration Medical Center at Birmingham, Birmingham, AL35294, USA
- Corresponding authors: Ralf Paus, MD, DSc: ; Andrzej T. Slominski, MD, PhD:
| | - Ralf Paus
- Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA
- Monasterium Laboratory, Münster, Germany
- CUTANEON – Skin & Hair Innovations, Hamburg, Germany
- Corresponding authors: Ralf Paus, MD, DSc: ; Andrzej T. Slominski, MD, PhD:
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GPNMB Extracellular Fragment Protects Melanocytes from Oxidative Stress by Inhibiting AKT Phosphorylation Independent of CD44. Int J Mol Sci 2021; 22:ijms221910843. [PMID: 34639184 PMCID: PMC8509362 DOI: 10.3390/ijms221910843] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/30/2021] [Accepted: 10/06/2021] [Indexed: 11/24/2022] Open
Abstract
Glycoprotein non-metastatic melanoma protein B (GPNMB) is a type I transmembrane glycoprotein that plays an important role in cancer metastasis and osteoblast differentiation. In the skin epidermis, GPNMB is mainly expressed in melanocytes and plays a critical role in melanosome formation. In our previous study, GPNMB was also found to be expressed in skin epidermal keratinocytes. In addition, decreased GPNMB expression was observed in the epidermis of lesional skin of patients with vitiligo. However, the exact role of keratinocyte-derived GPNMB and its effect on vitiligo is still unknown. In this study, we demonstrated that GPNMB expression was also decreased in rhododendrol-induced leukoderma, as seen in vitiligo. The extracellular soluble form of GPNMB (sGPNMB) was found to protect melanocytes from cytotoxicity and the impairment of melanogenesis induced by oxidative stress. Furthermore, the effect of rGPNMB was not altered by the knockdown of CD44, which is a well-known receptor of GPNMB, but accompanied by the suppressed phosphorylation of AKT but not ERK, p38, or JNK. In addition, we found that oxidative stress decreased both transcriptional GPNMB expression and sGPNMB protein expression in human keratinocytes. Our results suggest that GPNMB might provide novel insights into the mechanisms related to the pathogenesis of vitiligo and leukoderma.
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5
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Rosset C, Jaeger MDC, Filippi-Chiela E, Reis LB, Sartor ITS, Oliveira Netto CB, Farias CBD, Roesler R, Ashton-Prolla P. Primary cells derived from Tuberous Sclerosis Complex patients show autophagy alteration in the haploinsufficiency state. Genet Mol Biol 2021; 44:e20200475. [PMID: 34609442 PMCID: PMC8515215 DOI: 10.1590/1678-4685-gmb-2020-0475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 07/12/2021] [Indexed: 12/03/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is an autosomal dominant cancer predisposition disorder caused by heterozygous mutations in TSC1 or TSC2 genes and characterized by mTORC1 hyperactivation. TSC-associated tumors develop after loss of heterozygosity mutations and their treatment involves the use of mTORC1 inhibitors. We aimed to evaluate cellular processes regulated by mTORC1 in TSC cells with different mutations before tumor development. Flow cytometry analyses were performed to evaluate cell viability, cell cycle and autophagy in non-tumor primary TSC cells with different heterozygous mutations and in control cells without TSC mutations, before and after treatment with rapamycin (mTORC1 inhibitor). We did not observe differences in cell viability and cell cycle between the cell groups. However, autophagy was reduced in mutated cells. After rapamycin treatment, mutated cells showed a significant increase in the autophagy process (p=0.039). We did not observe differences between cells with distinct TSC mutations. Our main finding is the alteration of autophagy in non-tumor TSC cells. Previous studies in literature found autophagy alterations in tumor TSC cells or knock-out animal models. We showed that autophagy could be an important mechanism that leads to TSC tumor formation in the haploinsufficiency state. This result could guide future studies in this field.
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Affiliation(s)
- Clévia Rosset
- Hospital de Clínicas de Porto Alegre (HCPA), Centro de Pesquisa Experimental, Laboratório de Medicina Genômica, Porto Alegre, RS, Brazil.,Universidade Federal do Rio Grande do Sul (UFRGS), Programa de pós-graduação em genética e biologia molecular, Porto Alegre, RS, Brazil
| | - Mariane da Cunha Jaeger
- Hospital de Clínicas de Porto Alegre (HCPA), Centro de Pesquisa Experimental, Laboratório de Câncer e Neurobiologia, Porto Alegre, RS, Brazil.,Instituto do Câncer Infantil (ICI), Porto Alegre, RS, Brazil
| | - Eduardo Filippi-Chiela
- Universidade Federal do Rio Grande do Sul (UFRGS), Faculdade de Medicina (Famed), Programa de pós-graduação em gastroenterologia e hepatologia, Porto Alegre, RS, Brazil
| | - Larissa Brussa Reis
- Hospital de Clínicas de Porto Alegre (HCPA), Centro de Pesquisa Experimental, Laboratório de Medicina Genômica, Porto Alegre, RS, Brazil.,Universidade Federal do Rio Grande do Sul (UFRGS), Programa de pós-graduação em genética e biologia molecular, Porto Alegre, RS, Brazil
| | - Ivaine Taís Sauthier Sartor
- Hospital de Clínicas de Porto Alegre (HCPA), Centro de Pesquisa Experimental, Laboratório de Medicina Genômica, Porto Alegre, RS, Brazil.,Universidade Federal do Rio Grande do Sul (UFRGS), Programa de pós-graduação em genética e biologia molecular, Porto Alegre, RS, Brazil
| | | | - Caroline Brunetto de Farias
- Hospital de Clínicas de Porto Alegre (HCPA), Centro de Pesquisa Experimental, Laboratório de Câncer e Neurobiologia, Porto Alegre, RS, Brazil.,Instituto do Câncer Infantil (ICI), Porto Alegre, RS, Brazil
| | - Rafael Roesler
- Hospital de Clínicas de Porto Alegre (HCPA), Centro de Pesquisa Experimental, Laboratório de Câncer e Neurobiologia, Porto Alegre, RS, Brazil.,Universidade Federal do Rio Grande do Sul (UFRGS), Instituto de Ciências Básicas da Saúde (ICBS), Departamento de Farmacologia, Porto Alegre, RS, Brazil
| | - Patricia Ashton-Prolla
- Hospital de Clínicas de Porto Alegre (HCPA), Centro de Pesquisa Experimental, Laboratório de Medicina Genômica, Porto Alegre, RS, Brazil.,Universidade Federal do Rio Grande do Sul (UFRGS), Programa de pós-graduação em genética e biologia molecular, Porto Alegre, RS, Brazil.,Hospital de Clínicas de Porto Alegre (HCPA), Serviço de Genética Médica, Porto Alegre, RS, Brazil.,Universidade Federal do Rio Grande do Sul (UFRGS), Departamento de Genética, Porto Alegre, RS, Brazil
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6
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Espósito ACC, de Souza NP, Miot LDB, Miot HA. Deficit in autophagy: A possible mechanism involved in melanocyte hyperfunction in melasma. Indian J Dermatol Venereol Leprol 2021; 0:1-3. [PMID: 33871200 DOI: 10.25259/ijdvl_927_20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 12/01/2020] [Indexed: 11/04/2022]
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Clinical spectrum of MTOR-related hypomelanosis of Ito with neurodevelopmental abnormalities. Genet Med 2021; 23:1484-1491. [PMID: 33833411 PMCID: PMC8354853 DOI: 10.1038/s41436-021-01161-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 03/16/2021] [Accepted: 03/16/2021] [Indexed: 11/13/2022] Open
Abstract
Purpose Hypomelanosis of Ito (HI) is a skin marker of somatic mosaicism.
Mosaic MTOR pathogenic variants have been
reported in HI with brain overgrowth. We sought to delineate further the
pigmentary skin phenotype and clinical spectrum of neurodevelopmental
manifestations of MTOR-related HI. Methods From two cohorts totaling 71 patients with pigmentary mosaicism, we
identified 14 patients with Blaschko-linear and one with flag-like pigmentation
abnormalities, psychomotor impairment or seizures, and a postzygotic MTOR variant in skin. Patient records, including
brain magnetic resonance image (MRI) were reviewed. Immunostaining (n = 3) for melanocyte markers and
ultrastructural studies (n = 2) were performed on skin biopsies. Results MTOR variants were present in
skin, but absent from blood in half of cases. In a patient (p.[Glu2419Lys]
variant), phosphorylation of p70S6K was constitutively increased. In
hypopigmented skin of two patients, we found a decrease in stage 4 melanosomes
in melanocytes and keratinocytes. Most patients (80%) had macrocephaly or
(hemi)megalencephaly on MRI. Conclusion MTOR-related HI is a recognizable
neurocutaneous phenotype of patterned dyspigmentation, epilepsy, intellectual
deficiency, and brain overgrowth, and a distinct subtype of hypomelanosis
related to somatic mosaicism. Hypopigmentation may be due to a defect in
melanogenesis, through mTORC1 activation, similar to hypochromic patches in
tuberous sclerosis complex. Graphical Abstract ![]()
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8
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Reis LB, Filippi-Chiela EC, Ashton-Prolla P, Visioli F, Rosset C. The paradox of autophagy in Tuberous Sclerosis Complex. Genet Mol Biol 2021; 44:e20200014. [PMID: 33821877 PMCID: PMC8022228 DOI: 10.1590/1678-4685-gmb-2020-0014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 01/17/2021] [Indexed: 12/21/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disorder caused by germline mutations in TSC1 or TSC2 genes, which leads to the hyperactivation of the mTORC1 pathway, an important negative regulator of autophagy. This leads to the development of hamartomas in multiple organs. The variability in symptoms presents a challenge for the development of completely effective treatments for TSC. One option is the treatment with mTORC1 inhibitors, which are targeted to block cell growth and restore autophagy. However, the therapeutic effect of rapamycin seems to be more efficient in the early stages of hamartoma development, an effect that seems to be associated with the paradoxical role of autophagy in tumor establishment. Under normal conditions, autophagy is directly inhibited by mTORC1. In situations of bioenergetics stress, mTORC1 releases the Ulk1 complex and initiates the autophagy process. In this way, autophagy promotes the survival of established tumors by supplying metabolic precursors during nutrient deprivation; paradoxically, excessive autophagy has been associated with cell death in some situations. In spite of its paradoxical role, autophagy is an alternative therapeutic strategy that could be explored in TSC. This review compiles the findings related to autophagy and the new therapeutic strategies targeting this pathway in TSC.
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Affiliation(s)
- Larissa Brussa Reis
- Hospital de Clínicas de Porto Alegre (HCPA), Serviço de Pesquisa Experimental, Laboratório de Medicina Genômica, Porto Alegre, RS, Brazil.,Universidade Federal do Rio Grande do Sul (UFRGS), Programa de Pós-Graduação em Genética e Biologia Molecular, Porto Alegre, RS, Brazil
| | - Eduardo C Filippi-Chiela
- Hospital de Clínicas de Porto Alegre (HCPA), Serviço de Pesquisa Experimental, Laboratório de Medicina Genômica, Porto Alegre, RS, Brazil.,Universidade Federal do Rio Grande do Sul (UFRGS), Instituto de Ciências Básicas da Saúde, Departamento de Ciências Morfológicas, Porto Alegre, RS, Brazil
| | - Patricia Ashton-Prolla
- Hospital de Clínicas de Porto Alegre (HCPA), Serviço de Pesquisa Experimental, Laboratório de Medicina Genômica, Porto Alegre, RS, Brazil.,Universidade Federal do Rio Grande do Sul (UFRGS), Programa de Pós-Graduação em Genética e Biologia Molecular, Porto Alegre, RS, Brazil.,Hospital de Clínicas de Porto Alegre (HCPA), Serviço de Genética Médica, Porto Alegre, RS, Brazil
| | - Fernanda Visioli
- Universidade Federal do Rio Grande do Sul, Faculdade de Odontologia, Departamento de Patologia Oral, Porto Alegre, RS, Brazil
| | - Clévia Rosset
- Hospital de Clínicas de Porto Alegre (HCPA), Serviço de Pesquisa Experimental, Laboratório de Medicina Genômica, Porto Alegre, RS, Brazil.,Universidade Federal do Rio Grande do Sul (UFRGS), Programa de Pós-Graduação em Genética e Biologia Molecular, Porto Alegre, RS, Brazil
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9
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Lee AY. Skin Pigmentation Abnormalities and Their Possible Relationship with Skin Aging. Int J Mol Sci 2021; 22:ijms22073727. [PMID: 33918445 PMCID: PMC8038212 DOI: 10.3390/ijms22073727] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 03/24/2021] [Accepted: 04/01/2021] [Indexed: 12/13/2022] Open
Abstract
Skin disorders showing abnormal pigmentation are often difficult to manage because of their uncertain etiology or pathogenesis. Abnormal pigmentation is a common symptom accompanying aging skin. The association between skin aging and skin pigmentation abnormalities can be attributed to certain inherited disorders characterized by premature aging and abnormal pigmentation in the skin and some therapeutic modalities effective for both. Several molecular mechanisms, including oxidative stress, mitochondrial DNA mutations, DNA damage, telomere shortening, hormonal changes, and autophagy impairment, have been identified as involved in skin aging. Although each of these skin aging-related mechanisms are interconnected, this review examined the role of each mechanism in skin hyperpigmentation or hypopigmentation to propose the possible association between skin aging and pigmentation abnormalities.
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Affiliation(s)
- Ai-Young Lee
- Department of Dermatology, College of Medicine, Dongguk University Ilsan Hospital, 814 Siksa-dong, Ilsandong-gu, Goyang-si 410-773, Gyeonggi-do, Korea
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10
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Wu X, Yang Y, Xiang L, Zhang C. The fate of melanocyte: Mechanisms of cell death in vitiligo. Pigment Cell Melanoma Res 2020; 34:256-267. [PMID: 33346939 DOI: 10.1111/pcmr.12955] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 12/10/2020] [Indexed: 01/20/2023]
Abstract
Loss of melanocytes (MCs) is the most notable feature of vitiligo. Hence, it is critical to clarify the mechanisms of MC destruction in vitiligo. Apoptosis is most widely studied cell death pathways in vitiligo. In addition, the other two forms of cell death, conventional necrosis and autophagy seem to be involved in the death of vitiligo MCs under certain situations. Moreover, new types of regulated cell death including necroptosis, pyroptosis, and ferroptosis may also participate in the pathogenesis of vitiligo. Anoikis is likely to be connected with the death of detached MCs, which is provoked specifically by loss of anchorage. Primary phagocytosis, later called phagoptosis can execute death of viable cells, probably partly responsible for the loss of MCs in vitiligo. In this review, we aim to summarize the latest insights into various forms of MC death in vitiligo and discuss the corresponding mechanisms.
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Affiliation(s)
- Xiuyi Wu
- Department of Dermatology, Huashan Hospital, Fudan University, Shanghai, PR China
| | - Yiwen Yang
- Department of Dermatology, Huashan Hospital, Fudan University, Shanghai, PR China
| | - Leihong Xiang
- Department of Dermatology, Huashan Hospital, Fudan University, Shanghai, PR China
| | - Chengfeng Zhang
- Department of Dermatology, Huashan Hospital, Fudan University, Shanghai, PR China
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11
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Murase D, Kusaka-Kikushima A, Hachiya A, Fullenkamp R, Stepp A, Imai A, Ueno M, Kawabata K, Takahashi Y, Hase T, Ohuchi A, Nakamura S, Yoshimori T. Autophagy Declines with Premature Skin Aging resulting in Dynamic Alterations in Skin Pigmentation and Epidermal Differentiation. Int J Mol Sci 2020; 21:ijms21165708. [PMID: 32784909 PMCID: PMC7460956 DOI: 10.3390/ijms21165708] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 08/05/2020] [Accepted: 08/06/2020] [Indexed: 12/27/2022] Open
Abstract
Autophagy is a membrane traffic system that provides sustainable degradation of cellular components for homeostasis, and is thus considered to promote health and longevity, though its activity declines with aging. The present findings show deterioration of autophagy in association with premature skin aging. Autophagy flux was successfully determined in skin tissues, which demonstrated significantly decreased autophagy in hyperpigmented skin such as that seen in senile lentigo. Furthermore, an exacerbated decline in autophagy was confirmed in xerotic hyperpigmentation areas, accompanied by severe dehydration and a barrier defect, which showed correlations with skin physiological conditions. The enhancement of autophagy in skin ex vivo ameliorated skin integrity, including pigmentation and epidermal differentiation. The present results indicate that the restoration of autophagy can contribute to improving premature skin aging by various intrinsic and extrinsic factors via the normalization of protein homeostasis.
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Affiliation(s)
- Daiki Murase
- Biological Science Research, Kao Corporation, Haga 321-3497, Japan;
- Correspondence: ; Tel.: +81-285-68-7637
| | - Ayumi Kusaka-Kikushima
- Biological Science Research, Kao Corporation, Odawara 250-0002, Japan; (A.K.-K.); (M.U.); (K.K.); (Y.T.)
| | - Akira Hachiya
- Planning and Implementation, Kao Corporation, Haga 321-3497, Japan;
| | - Rachel Fullenkamp
- Americas Research Laboratories, Kao USA Inc., Cincinnati, OH 45214, USA; (R.F.); (A.S.); (A.I.)
| | - Anita Stepp
- Americas Research Laboratories, Kao USA Inc., Cincinnati, OH 45214, USA; (R.F.); (A.S.); (A.I.)
| | - Asuka Imai
- Americas Research Laboratories, Kao USA Inc., Cincinnati, OH 45214, USA; (R.F.); (A.S.); (A.I.)
| | - Mizuki Ueno
- Biological Science Research, Kao Corporation, Odawara 250-0002, Japan; (A.K.-K.); (M.U.); (K.K.); (Y.T.)
| | - Keigo Kawabata
- Biological Science Research, Kao Corporation, Odawara 250-0002, Japan; (A.K.-K.); (M.U.); (K.K.); (Y.T.)
| | - Yoshito Takahashi
- Biological Science Research, Kao Corporation, Odawara 250-0002, Japan; (A.K.-K.); (M.U.); (K.K.); (Y.T.)
| | - Tadashi Hase
- Core Technology Sector, Kao Corporation, Sumida 131-0044, Japan;
| | - Atsushi Ohuchi
- Biological Science Research, Kao Corporation, Haga 321-3497, Japan;
| | - Shuhei Nakamura
- Department of Genetics, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan; (S.N.); (T.Y.)
- Department of Intracellular Membrane Dynamics, Graduate School of Frontier Biosciences, Osaka University, Osaka 565-0871, Japan
| | - Tamotsu Yoshimori
- Department of Genetics, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan; (S.N.); (T.Y.)
- Department of Intracellular Membrane Dynamics, Graduate School of Frontier Biosciences, Osaka University, Osaka 565-0871, Japan
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12
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Beclin 1 controls pigmentation by changing the nuclear localization of melanogenic factor MITF. Biochem Biophys Res Commun 2020; 528:719-725. [PMID: 32513537 DOI: 10.1016/j.bbrc.2020.05.118] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 05/15/2020] [Indexed: 11/21/2022]
Abstract
The primary contributor for the determination of skin color is melanin, a pigment that is produced in specialized cells called melanocytes. At cellular level, melanin synthesis occurs through several enzymes like tyrosinase (TYR) and tyrosinase related proteins and the expression of these proteins are regulated transcriptionally by microphthalmia associated transcription factor (MITF). Melanin pigmentation is a complex process finely regulated by different transcription factors, structural proteins and enzymes. In recent times, several autophagic genes have been implicated in the regulation of pigmentation. Though previous report observed a visible loss of coat-color in heterozygous Beclin 1 mice, the role of this protein in pigmentation is yet to study in details. In this present work we intend to study the role of Beclin 1, a central autophagic factor, in pigmentation. Using human melanoma cells and primary melanocytes, we showed that Beclin 1 downregulation significantly decreased the melanin content, tyrosinase activity and the expression of TYR and tyrosinase related protein 1 (TYRP1). These effects were recapitulated in a Beclin 1 knockdown in vivo model of zebrafish. Most importantly, re-expression of Beclin 1 rescued the pigmentation-associated defects both in cellular and in organismal level indicating the specificity. Surprisingly, Beclin 1 knockdown cells did not show significant changes in MITF expression but the nuclear localization of MITF was altered. Together, these data suggest that indeed Beclin 1 is associated with melanogenesis and this effect is more likely exerted through the subcellular distribution rather than the change in expression of MITF.
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Safety and Efficacy of the Sirolimus Gel for TSC Patients With Facial Skin Lesions in a Long-Term, Open-Label, Extension, Uncontrolled Clinical Trial. Dermatol Ther (Heidelb) 2020; 10:635-650. [PMID: 32385845 PMCID: PMC7367957 DOI: 10.1007/s13555-020-00387-7] [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: 03/30/2020] [Indexed: 11/24/2022] Open
Abstract
Introduction Our previous clinical studies have demonstrated the short-term efficacy and safety of the sirolimus gel for patients with tuberous sclerosis complex (TSC). However, long-term clinical evidence is lacking. Our objective was to assess the safety and efficacy of long-term treatment with the sirolimus gel for the skin lesions of TSC patients. Methods We conducted a multicenter, open-label, uncontrolled clinical trial in 94 Japanese
patients with TSC. Patients applied the 0.2% sirolimus gel on their face or head twice daily for > 52 weeks (maximum 136 weeks for safety). The safety endpoints were the rate of adverse event (AE)-caused discontinuation (primary endpoint) and the incidence of AEs. The efficacy endpoint was the response rate of angiofibromas, cephalic plaques, and hypomelanotic macules. Results Among 94 enrolled patients (mean age, 21 years; range 3–53 years), the rate of AE-caused discontinuation was 2.1% (2/94 patients). Although application site irritation and dry skin occurred relatively frequently, none of the drug-related AEs were serious; most of the drug-related AEs resolved rapidly. The major drug-related AEs (≥ 5% in incidence) were application site irritation (30.9%), dry skin (27.7%), acne (20.2%), eye irritation (8.5%), pruritus (8.5%), erythema (7.4%), dermatitis acneiform (6.4%), and dermatitis contact (5.3%). The response rates of angiofibromas, cephalic plaques, and hypomelanotic macules were 78.2% [95% confidence interval (CI) 68.0–86.3%], 66.7% (95% CI 51.1–80.0%), and 72.2% (95% CI 46.5–90.3%), respectively. Conclusions The gel was well tolerated for a long time by patients with TSC involving facial skin lesions and continued to be effective. Trial Registration ClinicalTrials.gov identifier: NCT02634931.
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Eckhart L, Tschachler E, Gruber F. Autophagic Control of Skin Aging. Front Cell Dev Biol 2019; 7:143. [PMID: 31417903 PMCID: PMC6682604 DOI: 10.3389/fcell.2019.00143] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 07/11/2019] [Indexed: 12/13/2022] Open
Abstract
The skin forms the barrier to the environment. Maintenance of this barrier during aging requires orchestrated responses to variable types of stress, the continuous renewal of the epithelial compartment, and the homeostasis of long-lived cell types. Recent experimental evidence suggests that autophagy is critically involved in skin homeostasis and skin aging is associated with and partially caused by defects of autophagy. In the outer skin epithelium, autophagy is constitutively active during cornification of keratinocytes and increases the resistance to environmental stress. Experimental suppression of autophagy in the absence of stress is tolerated by the rapidly renewing epidermal epithelium, whereas long-lived skin cells such as melanocytes, Merkel cells and secretory cells of sweat glands depend on autophagy for cellular homeostasis and normal execution of their functions during aging. Yet other important roles of autophagy have been identified in the dermis where senescence of mesenchymal cells and alterations of the extracellular matrix (ECM) are hallmarks of aging. Here, we review the evidence for cell type-specific roles of autophagy in the skin and their differential contributions to aging.
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Affiliation(s)
- Leopold Eckhart
- Research Division of Biology and Pathobiology of the Skin, Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - Erwin Tschachler
- Research Division of Biology and Pathobiology of the Skin, Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - Florian Gruber
- Research Division of Biology and Pathobiology of the Skin, Department of Dermatology, Medical University of Vienna, Vienna, Austria.,Christian Doppler Laboratory for Biotechnology of Skin Aging, Vienna, Austria
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Insights into autophagy machinery in cells related to skin diseases and strategies for therapeutic modulation. Biomed Pharmacother 2019; 113:108775. [PMID: 30889485 DOI: 10.1016/j.biopha.2019.108775] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 03/11/2019] [Accepted: 03/13/2019] [Indexed: 02/05/2023] Open
Abstract
Autophagy, literally meaning "self-eating," is a highly conserved process that is part of the eukaryotic cell cycle. Morphologically, the double membrane contains vesicles with phagocytic components known as autophagosomes. Autophagy is often used as a cellular stress response and quality control mechanisms are used to maintain cell survival. Survival is facilitated by providing energy and metabolic precursors as well as removing damaged proteins or organelles. Moreover, autophagy refers to organelles fused together with part of the cell cytoplasm with a double or multi-membrane structure called phagosome. Research has demonstrated that autophagy is an important mediator of cell fate and has effects on inflammation, pathogen clearance, and antigen presentation. In recent years, studies discussing autophagy have increased in number. Nevertheless, only a small amount of research has considered the impact of autophagy on the pathogenesis of skin diseases. The skin is the largest organ of the body, with a surface area of around two square metre; it is the first line of defense against numerous environmental insults, including ultraviolet radiation, pathogens, mechanical stresses, and toxic chemicals. Autophagy is thought to be a vital modality for endogenous defenses against environmental derangements. This review provides an overview of autophagy machinery in keratinocytes, skin fibroblasts, melanocytes related to skin diseases as well as strategies for therapeutic modulation, for the future development of treatment for skin diseases.
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Sil P, Wong SW, Martinez J. More Than Skin Deep: Autophagy Is Vital for Skin Barrier Function. Front Immunol 2018; 9:1376. [PMID: 29988591 PMCID: PMC6026682 DOI: 10.3389/fimmu.2018.01376] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 06/04/2018] [Indexed: 12/30/2022] Open
Abstract
The skin is a highly organized first line of defense that stretches up to 1.8 m2 and is home to more than a million commensal bacteria. The microenvironment of skin is driven by factors such as pH, temperature, moisture, sebum level, oxidative stress, diet, resident immune cells, and infectious exposure. The skin has a high turnover of cells as it continually bares itself to environmental stresses. Notwithstanding these limitations, it has devised strategies to adapt as a nutrient-scarce site. To perform its protective function efficiently, it relies on mechanisms to continuously remove dead cells without alarming the immune system, actively purging the dying/senescent cells by immunotolerant efferocytosis. Both canonical (starvation-induced, reactive oxygen species, stress, and environmental insults) and non-canonical (selective) autophagy in the skin have evolved to perform astute due-diligence and housekeeping in a quiescent fashion for survival, cellular functioning, homeostasis, and immune tolerance. The autophagic “homeostatic rheostat” works tirelessly to uphold the delicate balance in immunoregulation and tolerance. If this equilibrium is upset, the immune system can wreak havoc and initiate pathogenesis. Out of all the organs, the skin remains under-studied in the context of autophagy. Here, we touch upon some of the salient features of autophagy active in the skin.
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Affiliation(s)
- Payel Sil
- Immunity, Inflammation, and Disease Laboratory, National Institute of Environmental Health Sciences, Durham, NC, United States
| | - Sing-Wai Wong
- Immunity, Inflammation, and Disease Laboratory, National Institute of Environmental Health Sciences, Durham, NC, United States.,Oral and Craniofacial Biomedicine Curriculum, School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Jennifer Martinez
- Immunity, Inflammation, and Disease Laboratory, National Institute of Environmental Health Sciences, Durham, NC, United States
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