1
|
Jian H, Zu P, Rao Y, Li W, Mou T, Lin J, Zhang F. Comparative analysis of melanin deposition between Chishui silky fowl and Taihe silky fowl. JOURNAL OF APPLIED ANIMAL RESEARCH 2021. [DOI: 10.1080/09712119.2021.1981911] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Huafeng Jian
- Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountainous Region, The Ministry of Education, Guizhou University, Guiyang, People’s Republic of China
- Guizhou Province Key Laboratory of Animal Genetics, Breeding and Reproduction, College of Animal Science, Guizhou University, Guiyang, People’s Republic of China
- Research Institute of Poultry, Guizhou University, Guiyang, People’s Republic of China
- Guizhou University Science and Research Poultry Farm, Guiyang, People’s Republic of China
| | - Panyu Zu
- Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountainous Region, The Ministry of Education, Guizhou University, Guiyang, People’s Republic of China
- Guizhou Province Key Laboratory of Animal Genetics, Breeding and Reproduction, College of Animal Science, Guizhou University, Guiyang, People’s Republic of China
- Research Institute of Poultry, Guizhou University, Guiyang, People’s Republic of China
- Guizhou University Science and Research Poultry Farm, Guiyang, People’s Republic of China
| | - Yongchao Rao
- Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountainous Region, The Ministry of Education, Guizhou University, Guiyang, People’s Republic of China
- Guizhou Province Key Laboratory of Animal Genetics, Breeding and Reproduction, College of Animal Science, Guizhou University, Guiyang, People’s Republic of China
- Research Institute of Poultry, Guizhou University, Guiyang, People’s Republic of China
- Guizhou University Science and Research Poultry Farm, Guiyang, People’s Republic of China
| | - Wei Li
- Guizhou Province Management Station of Livestock Genetic Resources, Guiyang, People’s Republic of China
| | - Tenghui Mou
- Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountainous Region, The Ministry of Education, Guizhou University, Guiyang, People’s Republic of China
- Guizhou Province Key Laboratory of Animal Genetics, Breeding and Reproduction, College of Animal Science, Guizhou University, Guiyang, People’s Republic of China
- Research Institute of Poultry, Guizhou University, Guiyang, People’s Republic of China
- Guizhou University Science and Research Poultry Farm, Guiyang, People’s Republic of China
| | - Jiadong Lin
- Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountainous Region, The Ministry of Education, Guizhou University, Guiyang, People’s Republic of China
- Guizhou Province Key Laboratory of Animal Genetics, Breeding and Reproduction, College of Animal Science, Guizhou University, Guiyang, People’s Republic of China
- Research Institute of Poultry, Guizhou University, Guiyang, People’s Republic of China
- Guizhou University Science and Research Poultry Farm, Guiyang, People’s Republic of China
| | - Fuping Zhang
- Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountainous Region, The Ministry of Education, Guizhou University, Guiyang, People’s Republic of China
- Guizhou Province Key Laboratory of Animal Genetics, Breeding and Reproduction, College of Animal Science, Guizhou University, Guiyang, People’s Republic of China
- Research Institute of Poultry, Guizhou University, Guiyang, People’s Republic of China
- Guizhou University Science and Research Poultry Farm, Guiyang, People’s Republic of China
| |
Collapse
|
2
|
Gregoric N, Groselj U, Bratina N, Debeljak M, Zerjav Tansek M, Suput Omladic J, Kovac J, Battelino T, Kotnik P, Avbelj Stefanija M. Two Cases With an Early Presented Proopiomelanocortin Deficiency-A Long-Term Follow-Up and Systematic Literature Review. Front Endocrinol (Lausanne) 2021; 12:689387. [PMID: 34177811 PMCID: PMC8220084 DOI: 10.3389/fendo.2021.689387] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 05/07/2021] [Indexed: 02/03/2023] Open
Abstract
Proopiomelanocortin (POMC) deficiency is an extremely rare inherited autosomal recessive disorder characterized by severe obesity, adrenal insufficiency, skin hypopigmentation, and red hair. It is caused by pathogenic variants in the POMC gene that codes the proopiomelanocortin polypeptide which is cleaved to several peptides; the most notable ones are adrenocorticotropic hormone (ACTH), alpha- and beta-melanocyte-stimulating hormones (α-MSH and β-MSH); the latter two are crucial in melanogenesis and the energy balance by regulating feeding behavior and energy homeostasis through melanocortin receptor 4 (MC4R). The lack of its regulation leads to polyphagia and early onset severe obesity. A novel MC4R agonist, setmelanotide, has shown promising results regarding weight loss in patients with POMC deficiency. A systematic review on previously published clinical and genetic characteristics of patients with POMC deficiency and additional data obtained from two unrelated patients in our care was performed. A 25-year-old male patient, partly previously reported, was remarkable for childhood developed type 1 diabetes (T1D), transient growth hormone deficiency, and delayed puberty. The second case is a girl with an unusual presentation with central hypothyroidism and normal pigmentation of skin and hair. Of all evaluated cases, only 50% of patients had characteristic red hair, fair skin, and eye phenotype. Central hypothyroidism was reported in 36% of patients; furthermore, scarce adolescent data indicate possible growth axis dysbalance and central hypogonadism. T1D was unexpectedly prevalent in POMC deficiency, reported in 14% of patients, which could be an underestimation. POMC deficiency reveals to be a syndrome with several endocrinological abnormalities, some of which may become apparent with time. Apart from timely diagnosis, careful clinical follow-up of patients through childhood and adolescence for possible additional disease manifestations is warranted.
Collapse
Affiliation(s)
- Nadan Gregoric
- Department for Endocrinology, Diabetes and Metabolic Diseases, Division of Internal Medicine, University Medical Centre Ljubljana, Ljubljana, Slovenia
- Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Urh Groselj
- Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
- Department of Endocrinology, Diabetes and Metabolic Diseases, University Children’s Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Natasa Bratina
- Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
- Department of Endocrinology, Diabetes and Metabolic Diseases, University Children’s Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Marusa Debeljak
- Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
- Clinical Institute for Special Laboratory Diagnostics, University Children’s Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Mojca Zerjav Tansek
- Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
- Department of Endocrinology, Diabetes and Metabolic Diseases, University Children’s Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Jasna Suput Omladic
- Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
- Department of Endocrinology, Diabetes and Metabolic Diseases, University Children’s Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Jernej Kovac
- Clinical Institute for Special Laboratory Diagnostics, University Children’s Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Tadej Battelino
- Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
- Department of Endocrinology, Diabetes and Metabolic Diseases, University Children’s Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Primoz Kotnik
- Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
- Department of Endocrinology, Diabetes and Metabolic Diseases, University Children’s Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Magdalena Avbelj Stefanija
- Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
- Department of Endocrinology, Diabetes and Metabolic Diseases, University Children’s Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
- *Correspondence: Magdalena Avbelj Stefanija,
| |
Collapse
|
3
|
Henkel J, Saif R, Jagannathan V, Schmocker C, Zeindler F, Bangerter E, Herren U, Posantzis D, Bulut Z, Ammann P, Drögemüller C, Flury C, Leeb T. Selection signatures in goats reveal copy number variants underlying breed-defining coat color phenotypes. PLoS Genet 2019; 15:e1008536. [PMID: 31841508 PMCID: PMC6936872 DOI: 10.1371/journal.pgen.1008536] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 12/30/2019] [Accepted: 11/23/2019] [Indexed: 12/16/2022] Open
Abstract
Domestication and human selection have formed diverse goat breeds with characteristic phenotypes. This process correlated with the fixation of causative genetic variants controlling breed-specific traits within regions of reduced genetic diversity, so called selection signatures or selective sweeps. Using whole genome sequencing of DNA pools (pool-seq) from 20 genetically diverse modern goat breeds and bezoars, we identified 2,239 putative selection signatures. In two Pakistani goat breeds, Pak Angora and Barbari, we found selection signatures in a region harboring KIT, a gene involved in melanoblast development, migration, and survival. The search for candidate causative variants responsible for these selective sweeps revealed two different copy number variants (CNVs) downstream of KIT that were exclusively present in white Pak Angora and white-spotted Barbari goats. Several Swiss goat breeds selected for specific coat colors showed selection signatures at the ASIP locus encoding the agouti signaling protein. Analysis of these selective sweeps revealed four different CNVs associated with the white or tan (AWt), Swiss markings (Asm), badgerface (Ab), and the newly proposed peacock (Apc) allele. RNA-seq analyses on skin samples from goats with the different CNV alleles suggest that the identified structural variants lead to an altered expression of ASIP between eumelanistic and pheomelanistic body areas. Our study yields novel insights into the genetic control of pigmentation by identifying six functionally relevant CNVs. It illustrates how structural changes of the genome have contributed to phenotypic evolution in domestic goats. Domestic animals have been selected for hundreds or sometimes even thousands of years for traits that were appreciated by their human owners. This process correlated with the fixation of causative genetic variants controlling breed-specific traits within regions of reduced genetic diversity, so called selection signatures or selective sweeps. We conducted a comprehensive screen for selection signatures in 20 phenotypically and genetically diverse modern goat breeds and identified a total of 2,239 putative selection signatures in our dataset. Follow-up experiments on selection signatures harboring known candidate genes for coat color revealed six different copy number variants (CNVs). Two of these CNVs were located in the 3’-flanking region of KIT and associated with a completely white coat color phenotype in Pak Angora goats and a white-spotted coat color phenotype in Barbari goats, respectively. The other four CNVs were located at the ASIP locus. They were associated with four different types of coat color patterning in seven Swiss goat breeds. Their functional effect is mediated by region-specific quantitative changes in ASIP mRNA expression. Our study illustrates how structural changes of the genome have contributed to phenotypic evolution in domestic goats.
Collapse
Affiliation(s)
- Jan Henkel
- Institute of Genetics, Vetsuisse Faculty, University of Bern, Bern, Switzerland
- DermFocus, University of Bern, Bern, Switzerland
| | - Rashid Saif
- Institute of Genetics, Vetsuisse Faculty, University of Bern, Bern, Switzerland
- Institute of Biotechnology, Gulab Devi Educational Complex, Lahore, Pakistan
| | - Vidhya Jagannathan
- Institute of Genetics, Vetsuisse Faculty, University of Bern, Bern, Switzerland
- DermFocus, University of Bern, Bern, Switzerland
| | - Corinne Schmocker
- Institute of Genetics, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Flurina Zeindler
- School of Agricultural, Forest and Food Sciences, Bern University of Applied Sciences, Zollikofen, Switzerland
| | | | - Ursula Herren
- Swiss Goat Breeding Association, Zollikofen, Switzerland
| | | | - Zafer Bulut
- Department of Biochemistry, Faculty of Veterinary Medicine, Selcuk University, Konya, Turkey
| | | | - Cord Drögemüller
- Institute of Genetics, Vetsuisse Faculty, University of Bern, Bern, Switzerland
- DermFocus, University of Bern, Bern, Switzerland
| | - Christine Flury
- School of Agricultural, Forest and Food Sciences, Bern University of Applied Sciences, Zollikofen, Switzerland
| | - Tosso Leeb
- Institute of Genetics, Vetsuisse Faculty, University of Bern, Bern, Switzerland
- DermFocus, University of Bern, Bern, Switzerland
- * E-mail:
| |
Collapse
|
4
|
Kozma R, Rödin-Mörch P, Höglund J. Genomic regions of speciation and adaptation among three species of grouse. Sci Rep 2019; 9:812. [PMID: 30692562 PMCID: PMC6349846 DOI: 10.1038/s41598-018-36880-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 11/27/2018] [Indexed: 12/30/2022] Open
Abstract
Understanding the molecular basis of adaption is one of the central goals in evolutionary biology and when investigated across sister species it can provide detailed insight into the mechanisms of speciation. Here, we sequence the genomes of 34 individuals from three closely related grouse species in order to uncover the genomic architecture of speciation and the genes involved in adaptation. We identify 6 regions, containing 7 genes that show lineage specific signs of differential selection across the species. These genes are involved in a variety of cell processes ranging from stress response to neural, gut, olfactory and limb development. Genome wide neutrality test statistics reveal a strong signal of population expansion acting across the genomes. Additionally, we uncover a 3.5 Mb region on chromosome 20 that shows considerably lower levels of differentiation across the three grouse lineages, indicating possible action of uniform selection in this region.
Collapse
Affiliation(s)
- Radoslav Kozma
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, Uppsala, SE-75236, Sweden
| | - Patrik Rödin-Mörch
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, Uppsala, SE-75236, Sweden
| | - Jacob Höglund
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, Uppsala, SE-75236, Sweden.
| |
Collapse
|
5
|
cAMP-mediated regulation of melanocyte genomic instability: A melanoma-preventive strategy. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2018; 115:247-295. [PMID: 30798934 DOI: 10.1016/bs.apcsb.2018.10.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Malignant melanoma of the skin is the leading cause of death from skin cancer and ranks fifth in cancer incidence among all cancers in the United States. While melanoma mortality has remained steady for the past several decades, melanoma incidence has been increasing, particularly among fair-skinned individuals. According to the American Cancer Society, nearly 10,000 people in the United States will die from melanoma this year. Individuals with dark skin complexion are protected damage generated by UV-light due to the high content of UV-blocking melanin pigment in their epidermis as well as better capacity for melanocytes to cope with UV damage. There is now ample evidence that suggests that the melanocortin 1 receptor (MC1R) is a major melanoma risk factor. Inherited loss-of-function mutations in MC1R are common in melanoma-prone persons, correlating with a less melanized skin complexion and poorer recovery from mutagenic photodamage. We and others are interested in the MC1R signaling pathway in melanocytes, its mechanisms of enhancing genomic stability and pharmacologic opportunities to reduce melanoma risk based on those insights. In this chapter, we review melanoma risk factors, the MC1R signaling pathway, and the relationship between MC1R signaling and DNA repair.
Collapse
|
6
|
Nazari-Ghadikolaei A, Mehrabani-Yeganeh H, Miarei-Aashtiani SR, Staiger EA, Rashidi A, Huson HJ. Genome-Wide Association Studies Identify Candidate Genes for Coat Color and Mohair Traits in the Iranian Markhoz Goat. Front Genet 2018; 9:105. [PMID: 29670642 PMCID: PMC5893768 DOI: 10.3389/fgene.2018.00105] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 03/16/2018] [Indexed: 12/31/2022] Open
Abstract
The Markhoz goat provides an opportunity to study the genetics underlying coat color and mohair traits of an Angora type goat using genome-wide association studies (GWAS). This indigenous Iranian breed is valued for its quality mohair used in ceremonial garments and has the distinction of exhibiting an array of coat colors including black, brown, and white. Here, we performed 16 GWAS for different fleece (mohair) traits and coat color in 228 Markhoz goats sampled from the Markhoz Goat Research Station in Sanandaj, Kurdistan province, located in western Iran using the Illumina Caprine 50K beadchip. The Efficient Mixed Model Linear analysis was used to identify genomic regions with potential candidate genes contributing to coat color and mohair characteristics while correcting for population structure. Significant associations to coat color were found within or near the ASIP, ITCH, AHCY, and RALY genes on chromosome 13 for black and brown coat color and the KIT and PDGFRA genes on chromosome 6 for white coat color. Individual mohair traits were analyzed for genetic association along with principal components that allowed for a broader perspective of combined traits reflecting overall mohair quality and volume. A multitude of markers demonstrated significant association to mohair traits highlighting potential candidate genes of POU1F1 on chromosome 1 for mohair quality, MREG on chromosome 2 for mohair volume, DUOX1 on chromosome 10 for yearling fleece weight, and ADGRV1 on chromosome 7 for grease percentage. Variation in allele frequencies and haplotypes were identified for coat color and differentiated common markers associated with both brown and black coat color. This demonstrates the potential for genetic markers to be used in future breeding programs to improve selection for coat color and mohair traits. Putative candidate genes, both novel and previously identified in other species or breeds, require further investigation to confirm phenotypic causality and potential epistatic relationships.
Collapse
Affiliation(s)
- Anahit Nazari-Ghadikolaei
- Department of Animal Science, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran
| | - Hassan Mehrabani-Yeganeh
- Department of Animal Science, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran
| | - Seyed R. Miarei-Aashtiani
- Department of Animal Science, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran
| | | | - Amir Rashidi
- Department of Animal Science, Faculty of Agriculture Engineering, University of Kurdistan, Sanandaj, Iran
| | - Heather J. Huson
- Department of Animal Science, Cornell University, Ithaca, NY, United States
| |
Collapse
|
7
|
Hepp D, Gonçalves GL, Moreira GRP, de Freitas TRO. Epistatic Interaction of the Melanocortin 1 Receptor and Agouti Signaling Protein Genes Modulates Wool Color in the Brazilian Creole Sheep. J Hered 2016; 107:544-52. [PMID: 27288530 DOI: 10.1093/jhered/esw037] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Accepted: 05/29/2016] [Indexed: 02/01/2023] Open
Abstract
Different pigmentation genes have been associated with color diversity in domestic animal species. The melanocortin 1 receptor (MC1R), agouti signaling protein (ASIP), tyrosinase-related protein 1 (TYRP1), and v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog (KIT) genes are candidate genes responsible for variation in wool color among breeds of sheep. Although the influence of these genes has been described in some breeds, in many others the effect of interactions among genes underlying wool color has not been investigated. The Brazilian Creole sheep is a local breed with a wide variety of wool color, ranging from black to white with several intermediate hues. We analyzed in this study the influence of the genes MC1R, ASIP, TYRP1, and KIT on the control of wool color in this breed. A total of 410 samples were analyzed, including 148 white and 262 colored individuals. The MC1R and ASIP polymorphisms were significantly associated with the segregation of either white or colored wool. The dominant MC1R allele (E(D) p.M73K and p.D121N) was present only in colored animals. All white individuals were homozygous for the MC1R recessive allele (E(+)) and carriers of the duplicated copy of ASIP A gene expression assay showed that only the carrier of the duplicated copy of ASIP produces increased levels in skin, not detectable in the single homozygous copy. These results demonstrate that the epistatic interaction of the genotypes in the MC1R and ASIP gene is responsible for the striking color variation in the Creole breed.
Collapse
Affiliation(s)
- Diego Hepp
- From the Departamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil (Hepp, Gonçalves, and de Freitas); Instituto de Alta Investigación, Universidad de Tarapacá, Arica, Chile (Gonçalves); Departamento de Zoologia, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil (Moreira); and Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil (Hepp).
| | - Gislene Lopes Gonçalves
- From the Departamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil (Hepp, Gonçalves, and de Freitas); Instituto de Alta Investigación, Universidad de Tarapacá, Arica, Chile (Gonçalves); Departamento de Zoologia, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil (Moreira); and Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil (Hepp)
| | - Gilson Rudinei Pires Moreira
- From the Departamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil (Hepp, Gonçalves, and de Freitas); Instituto de Alta Investigación, Universidad de Tarapacá, Arica, Chile (Gonçalves); Departamento de Zoologia, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil (Moreira); and Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil (Hepp)
| | - Thales Renato Ochotorena de Freitas
- From the Departamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil (Hepp, Gonçalves, and de Freitas); Instituto de Alta Investigación, Universidad de Tarapacá, Arica, Chile (Gonçalves); Departamento de Zoologia, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil (Moreira); and Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil (Hepp)
| |
Collapse
|
8
|
Wolf Horrell EM, Boulanger MC, D’Orazio JA. Melanocortin 1 Receptor: Structure, Function, and Regulation. Front Genet 2016; 7:95. [PMID: 27303435 PMCID: PMC4885833 DOI: 10.3389/fgene.2016.00095] [Citation(s) in RCA: 141] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 05/13/2016] [Indexed: 01/04/2023] Open
Abstract
The melanocortin 1 receptor (MC1R) is a melanocytic Gs protein coupled receptor that regulates skin pigmentation, UV responses, and melanoma risk. It is a highly polymorphic gene, and loss of function correlates with a fair, UV-sensitive, and melanoma-prone phenotype due to defective epidermal melanization and sub-optimal DNA repair. MC1R signaling, achieved through adenylyl cyclase activation and generation of the second messenger cAMP, is hormonally controlled by the positive agonist melanocortin, the negative agonist agouti signaling protein, and the neutral antagonist β-defensin 3. Activation of cAMP signaling up-regulates melanin production and deposition in the epidermis which functions to limit UV penetration into the skin and enhances nucleotide excision repair (NER), the genomic stability pathway responsible for clearing UV photolesions from DNA to avoid mutagenesis. Herein we review MC1R structure and function and summarize our laboratory's findings on the molecular mechanisms by which MC1R signaling impacts NER.
Collapse
Affiliation(s)
- Erin M. Wolf Horrell
- Department of Physiology, University of Kentucky College of MedicineLexington, KY, USA
| | - Mary C. Boulanger
- Markey Cancer Center, University of Kentucky College of MedicineLexington, KY, USA
| | - John A. D’Orazio
- Department of Physiology, University of Kentucky College of MedicineLexington, KY, USA
- Markey Cancer Center, University of Kentucky College of MedicineLexington, KY, USA
- Departments of Pediatrics, Toxicology and Cancer Biology, Physiology, and Pharmacology and Nutritional Sciences, University of Kentucky College of MedicineLexington, KY, USA
| |
Collapse
|
9
|
Interacting Neural Processes of Feeding, Hyperactivity, Stress, Reward, and the Utility of the Activity-Based Anorexia Model of Anorexia Nervosa. Harv Rev Psychiatry 2016; 24:416-436. [PMID: 27824637 PMCID: PMC5485261 DOI: 10.1097/hrp.0000000000000111] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Anorexia nervosa (AN) is a psychiatric illness with minimal effective treatments and a very high rate of mortality. Understanding the neurobiological underpinnings of the disease is imperative for improving outcomes and can be aided by the study of animal models. The activity-based anorexia rodent model (ABA) is the current best parallel for the study of AN. This review describes the basic neurobiology of feeding and hyperactivity seen in both ABA and AN, and compiles the research on the role that stress-response and reward pathways play in modulating the homeostatic drive to eat and to expend energy, which become dysfunctional in ABA and AN.
Collapse
|
10
|
García-Borrón JC, Abdel-Malek Z, Jiménez-Cervantes C. MC1R, the cAMP pathway, and the response to solar UV: extending the horizon beyond pigmentation. Pigment Cell Melanoma Res 2014; 27:699-720. [PMID: 24807163 DOI: 10.1111/pcmr.12257] [Citation(s) in RCA: 133] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 05/01/2014] [Indexed: 12/20/2022]
Abstract
The melanocortin 1 receptor (MC1R) is a G protein-coupled receptor crucial for the regulation of melanocyte proliferation and function. Upon binding melanocortins, MC1R activates several signaling cascades, notably the cAMP pathway leading to synthesis of photoprotective eumelanin. Polymorphisms in the MC1R gene are a major source of normal variation of human hair color and skin pigmentation, response to ultraviolet radiation (UVR), and skin cancer susceptibility. The identification of a surprisingly high number of MC1R natural variants strongly associated with pigmentary phenotypes and increased skin cancer risk has prompted research on the functional properties of the wild-type receptor and frequent mutant alleles. We summarize current knowledge on MC1R structural and functional properties, as well as on its intracellular trafficking and signaling. We also review the current knowledge about the function of MC1R as a skin cancer, particularly melanoma, susceptibility gene and how it modulates the response of melanocytes to UVR.
Collapse
Affiliation(s)
- Jose C García-Borrón
- Department of Biochemistry and Molecular Biology, School of Medicine, University of Murcia, Murcia, Spain; Instituto Murciano de Investigación Biomédica (IMIB), El Palmar, Murcia, Spain
| | | | | |
Collapse
|
11
|
Lee BW, Schwartz RA, Hercogová J, Valle Y, Lotti TM. Vitiligo road map. Dermatol Ther 2013; 25 Suppl 1:S44-56. [PMID: 23237038 DOI: 10.1111/dth.12006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Vitiligo is a depigmenting disorder stemming from melanocyte loss or dysfunction. It has a complex, multifaceted etiology. We constructed a "vitiligo road map," consisting of basic science, clinical, and treatment components, in order to better portray our current understanding of vitiligo pathogenesis and reflect upon novel biomarkers and therapeutic targets for future research. The melanocyte map elaborates on the molecular processes and intracellular signaling pathways initiated by various external autocrine/paracrine factors in representing normal melanocyte homeostatic functions modulating its viability, proliferation, differentiation, dendricity, migration, and melanogenic processes. This vitiligo map identifies known inducers/triggers of vitiligo onset and progression that cultivate a microenvironment for melanocyte disappearance, real or functional. This map describes the molecular mechanisms of currently utilized clinical and experimental treatments of vitiligo that facilitate repigmentation.
Collapse
Affiliation(s)
- Brian W Lee
- Dermatology and Pathology, New Jersey Medical School, Newark, New Jersey 07103-2714, USA
| | | | | | | | | |
Collapse
|
12
|
Cirillo G, Marini R, Ito S, Wakamatsu K, Scianguetta S, Bizzarri C, Romano A, Grandone A, Perrone L, Cappa M, Miraglia Del Giudice E. Lack of red hair phenotype in a North-African obese child homozygous for a novel POMC null mutation: nonsense-mediated decay RNA evaluation and hair pigment chemical analysis. Br J Dermatol 2012; 167:1393-5. [PMID: 22612534 DOI: 10.1111/j.1365-2133.2012.11060.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
13
|
Yamamuro Y, Shiraishi A. Genotype-dependent participation of coat color gene loci in the behavioral traits of laboratory mice. Behav Processes 2011; 88:81-7. [PMID: 21854838 DOI: 10.1016/j.beproc.2011.08.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 07/21/2011] [Accepted: 08/02/2011] [Indexed: 10/17/2022]
|
14
|
Hida T, Wakamatsu K, Sviderskaya EV, Donkin AJ, Montoliu L, Lynn Lamoreux M, Yu B, Millhauser GL, Ito S, Barsh GS, Jimbow K, Bennett DC. Agouti protein, mahogunin, and attractin in pheomelanogenesis and melanoblast-like alteration of melanocytes: a cAMP-independent pathway. Pigment Cell Melanoma Res 2009; 22:623-34. [PMID: 19493315 PMCID: PMC2784899 DOI: 10.1111/j.1755-148x.2009.00582.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Melanocortin-1 receptor (MC1R) and its ligands, α-melanocyte stimulating hormone (αMSH) and agouti signaling protein (ASIP), regulate switching between eumelanin and pheomelanin synthesis in melanocytes. Here we investigated biological effects and signaling pathways of ASIP. Melan-a non agouti (a/a) mouse melanocytes produce mainly eumelanin, but ASIP combined with phenylthiourea and extra cysteine could induce over 200-fold increases in the pheomelanin to eumelanin ratio, and a tan-yellow color in pelletted cells. Moreover, ASIP-treated cells showed reduced proliferation and a melanoblast-like appearance, seen also in melanocyte lines from yellow (Ay/a and Mc1re/ Mc1re) mice. However ASIP-YY, a C-terminal fragment of ASIP, induced neither biological nor pigmentary changes. As, like ASIP, ASIP-YY inhibited the cAMP rise induced by αMSH analog NDP-MSH, and reduced cAMP level without added MSH, the morphological changes and depigmentation seemed independent of cAMP signaling. Melanocytes genetically null for ASIP mediators attractin or mahogunin (Atrnmg-3J/mg-3J or Mgrn1md-nc/md-nc) also responded to both ASIP and ASIP-YY in cAMP level, while only ASIP altered their proliferation and (in part) shape. Thus, ASIP–MC1R signaling includes a cAMP-independent pathway through attractin and mahogunin, while the known cAMP-dependent component requires neither attractin nor mahogunin.
Collapse
Affiliation(s)
- Tokimasa Hida
- Division of Basic Medical Sciences, St. George's, University of London, Cranmer Terrace, London, UK
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Le Pape E, Wakamatsu K, Ito S, Wolber R, Hearing VJ. Regulation of eumelanin/pheomelanin synthesis and visible pigmentation in melanocytes by ligands of the melanocortin 1 receptor. Pigment Cell Melanoma Res 2008; 21:477-86. [PMID: 18627531 DOI: 10.1111/j.1755-148x.2008.00479.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The production of melanin in the hair and skin is tightly regulated by the melanocortin 1 receptor (MC1R) whose activation is controlled by two secreted ligands, alpha-melanocyte stimulating hormone (alphaMSH) and agouti signal protein (ASP). As melanin is extremely stable, lasting years in biological tissues, the mechanism underlying the relatively rapid decrease in visible pigmentation elicited by ASP is of obvious interest. In this study, the effects of ASP and alphaMSH on the regulation of melanin synthesis and on visible pigmentation were assessed in normal murine melanocytes and were compared with the quick depigmenting effect of the tyrosinase inhibitor, phenylthiourea (PTU). alphaMSH increased pheomelanin levels prior to increasing eumelanin content over 4 days of treatment. Conversely, ASP switched off the pigment synthesis pathway, reducing eu- and pheo-melanin synthesis within 1 day of treatment that was proportional to the decrease in tyrosinase protein level and activity. These results demonstrate that the visible depigmentation of melanocytes induced by ASP does not require the degradation of existing melanin but rather is due to the dilution of existing melanin by melanocyte turnover, which emphasizes the importance of pigment distribution to visible color.
Collapse
Affiliation(s)
- Elodie Le Pape
- Pigment Cell Biology Section, Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | | | | | | | | |
Collapse
|
16
|
Smit MJ, Vischer HF, Bakker RA, Jongejan A, Timmerman H, Pardo L, Leurs R. Pharmacogenomic and Structural Analysis of Constitutive G Protein–Coupled Receptor Activity. Annu Rev Pharmacol Toxicol 2007; 47:53-87. [PMID: 17029567 DOI: 10.1146/annurev.pharmtox.47.120505.105126] [Citation(s) in RCA: 145] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
G protein-coupled receptors (GPCRs) respond to a chemically diverse plethora of signal transduction molecules. The notion that GPCRs also signal without an external chemical trigger, i.e., in a constitutive or spontaneous manner, resulted in a paradigm shift in the field of GPCR pharmacology. The discovery of constitutive GPCR activity and the fact that GPCR binding and signaling can be strongly affected by a single point mutation drew attention to the evolving area of GPCR pharmacogenomics. For a variety of GPCRs, point mutations have been convincingly linked to human disease. Mutations within conserved motifs, known to be involved in GPCR activation, might explain the properties of some naturally occurring, constitutively active GPCR variants linked to disease. In this review, we provide a brief historical introduction to the concept of constitutive receptor activity and the pharmacogenomic and structural aspects of constitutive receptor activity.
Collapse
Affiliation(s)
- Martine J Smit
- Leiden/Amsterdam Center for Drug Research, Division of Medicinal Chemistry, Vrije Universiteit, Faculty of Sciences, Department of Chemistry, 1081 HV Amsterdam, The Netherlands.
| | | | | | | | | | | | | |
Collapse
|
17
|
Ellacott KLJ, Halatchev IG, Cone RD. Interactions between gut peptides and the central melanocortin system in the regulation of energy homeostasis. Peptides 2006; 27:340-9. [PMID: 16309792 DOI: 10.1016/j.peptides.2005.02.031] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2004] [Accepted: 02/21/2005] [Indexed: 12/20/2022]
Abstract
Genetic and pharmacological studies have shown that the central melanocortin system plays a critical role in the regulation of energy homeostasis. Animals and humans with defects in the central melanocortin system display a characteristic melanocortin obesity phenotype typified by increased adiposity, hyperphagia, metabolic defects and increased linear growth. In addition to interacting with long-term regulators of energy homeostasis such as leptin, more recent data suggest that the central melanocortin system also responds to gut-released peptides involved in mediating satiety. In this review, we discuss the interactions between these systems, with particular emphasis on cholecystokinin (CCK), ghrelin and PYY(3-36).
Collapse
Affiliation(s)
- Kate L J Ellacott
- Vollum Institute and The Center for Weight Regulation and Associated Disorders, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd, Portland, OR 97239-3098, USA
| | | | | |
Collapse
|
18
|
García-Borrón JC, Sánchez-Laorden BL, Jiménez-Cervantes C. Melanocortin-1 receptor structure and functional regulation. ACTA ACUST UNITED AC 2006; 18:393-410. [PMID: 16280005 DOI: 10.1111/j.1600-0749.2005.00278.x] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The melanogenic actions of the melanocortins are mediated by the melanocortin-1 receptor (MC1R). MC1R is a member of the G-protein-coupled receptors (GPCR) superfamily expressed in cutaneous and hair follicle melanocytes. Activation of MC1R by adrenocorticotrophin or alpha-melanocyte stimulating hormone is positively coupled to the cAMP signaling pathway and leads to a stimulation of melanogenesis and a switch from the synthesis of pheomelanins to the production of eumelanic pigments. The functional behavior of the MC1R agrees with emerging concepts in GPCR signaling including dimerization, coupling to more than one signaling pathway and a high agonist-independent constitutive activity accounting for inverse agonism phenomena. In addition, MC1R displays unique properties such as an unusually high number of natural variants often associated with clearly visible phenotypes and the occurrence of endogenous peptide antagonists. Therefore MC1R is an ideal model to study GPCR function. Here we review our current knowledge of MC1R structure and function, with emphasis on information gathered from the analysis of natural variants. We also discuss recent data on the regulation of MC1R function by paracrine and endocrine factors and by external stimuli such as ultraviolet light.
Collapse
Affiliation(s)
- José C García-Borrón
- Department of Biochemistry and Molecular Biology, School of Medicine, University of Murcia, Murcia, Spain.
| | | | | |
Collapse
|
19
|
Slominski A, Plonka PM, Pisarchik A, Smart JL, Tolle V, Wortsman J, Low MJ. Preservation of eumelanin hair pigmentation in proopiomelanocortin-deficient mice on a nonagouti (a/a) genetic background. Endocrinology 2005; 146:1245-53. [PMID: 15564334 PMCID: PMC1201461 DOI: 10.1210/en.2004-0733] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The original strain of proopiomelanocortin (POMC)-deficient mice (Pomc-/-) was generated by homologous recombination in 129X1/SvJ (A(w)/A(w))-derived embryonic stem cells using a targeting construct that deleted exon 3, encoding all the known functional POMC-derived peptides including alpha MSH, from the Pomc gene. Although these Pomc-/- mice exhibited adrenal hypoplasia and obesity similar to the syndrome of POMC deficiency in children, their agouti coat color was only subtly altered. To further investigate the mechanism of hair pigmentation in the absence of POMC peptides, we studied wild-type (Pomc+/+), heterozygous (Pomc+/-), and homozygous (Pomc-/-) mice on a nonagouti (a/a) 129;B6 hybrid genetic background. All three genotypes had similar black fur pigmentation with yellow hairs behind the ears, around the nipples, and in the perianal area characteristic of inbred C57BL/6 mice. Histologic and electron paramagnetic resonance spectrometry examination demonstrated that hair follicles in back skin of Pomc-/- mice developed with normal structure and eumelanin pigmentation; corresponding molecular analyses, however, excluded local production of alpha MSH and ACTH because neither Pomc nor putative Pomc pseudogene mRNAs were detected in the skin. Thus, 129;B6 Pomc null mutant mice produce abundant eumelanin hair pigmentation despite their congenital absence of melanocortin ligands. These results suggest that either the mouse melanocortin receptor 1 has sufficient basal activity to trigger and sustain eumelanogenesis in vivo or that redundant nonmelanocortin pathway(s) compensate for the melanocortin deficiency. Whereas the latter implies feedback control of melanogenesis, it is also possible that the two mechanisms operate jointly in hair follicles.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Malcolm J. Low
- Address all correspondence and requests for reprints to: Malcolm J. Low, M.D., Ph.D., Vollum Institute, L-474, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239-3098. E-mail:
| |
Collapse
|
20
|
Sánchez-Más J, Hahmann C, Gerritsen I, García-Borrón JC, Jiménez-Cervantes C. Agonist-independent, high constitutive activity of the human melanocortin 1 receptor. ACTA ACUST UNITED AC 2005; 17:386-95. [PMID: 15250941 DOI: 10.1111/j.1600-0749.2004.00160.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The melanocortins (alpha-melanocyte-stimulating hormone and adrenocorticotropin) act on epidermal melanocytes to increase melanogenesis, the eumelanin/pheomelanin ratio and dendricity. These actions are mediated by the heptahelical melanocortin 1 receptor (MC1R), positively coupled to adenylyl cyclase. Gain-of-function mouse Mc1r alleles are associated with a dark, eumelanic coat. Conversely, loss-of-function variants, or overexpression of agouti, a natural melanocortin antagonist, yield yellow, pheomelanic furs. In humans, loss-of-function MC1R variants are associated with fair skin, poor tanning, propensity to freckle and increased skin cancer risk. Therefore, MC1R is a key regulator of mammalian pigmentation. Several observations such as induction of constitutive pigmentation in amelanotic mouse melanoma cells following expression of MC1R indicate that the receptor might display agonist-independent activity. We report a systematic and comparative study of MC1R and Mc1r constitutive activity. We show that expression of MC1R in heterologous systems leads to an agonist-independent increase in cyclic adenosine monophophate (cAMP). Basal signalling is a function of receptor expression and is two to fourfold higher for MC1R than for Mc1r. Moreover, it is observed in human melanoma cells over-expressing the MC1R. Constitutive signalling is abolished or reduced by point mutations of MC1R impairing the response to agonists, and is only doubled by the Lys94Glu mutation, mimicking the constitutively active mouse E(so-3J) allele. Stable or transient expression of wild-type MC1R, but not of loss-of-function mutants, potently stimulates forskolin activation of adenylyl cyclase, a common feature of constitutively active Gs-coupled receptors. Therefore, human MC1R displays a strong agonist-independent constitutive activity.
Collapse
Affiliation(s)
- Jesús Sánchez-Más
- Department of Biochemistry and Molecular Biology, School of Medicine, University of Murcia, 30071 Espinardo, Spain
| | | | | | | | | |
Collapse
|
21
|
Ito S, Wakamatsu K. Quantitative analysis of eumelanin and pheomelanin in humans, mice, and other animals: a comparative review. PIGMENT CELL RESEARCH 2003; 16:523-31. [PMID: 12950732 DOI: 10.1034/j.1600-0749.2003.00072.x] [Citation(s) in RCA: 293] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The color of hair, skin, and eyes in animals mainly depends on the quantity, quality, and distribution of the pigment melanin, which occurs in two types: black to brown eumelanin and yellow to reddish pheomelanin. Microanalytical methods to quantify the amounts of eumelanin and pheomelanin in biological materials were developed in 1985. The methods are based on the chemical degradation of eumelanin to pyrrole-2,3,5-tricarboxylic acid and of pheomelanin to aminohydroxyphenylalanine isomers, which can be analyzed and quantitated by high performance liquid chromatography. This review summarizes and compares eumelanin and pheomelanin contents in various pigmented tissues obtained from humans, mice, and other animals. These methods have become valuable tools to study the functions of melanin, the control of melanogenesis, and the actions and interactions of pigmentation genes. The methods have also found applications in many clinical studies. High levels of pheomelanin are found only in yellow to red hairs of mammals and in red feathers of birds. It remains an intriguing question why lower vertebrates such as fishes do not synthesize pheomelanin. Detectable levels of pheomelanin are detected in human skin regardless of race, color, and skin type. However, eumelanin is always the major constituent of epidermal melanin, and the skin color appears to be determined by the quantity of melanin produced but not by the quality.
Collapse
Affiliation(s)
- Shosuke Ito
- Department of Chemistry, Fujita Health University School of Health Sciences, Toyoake, Aichi, Japan.
| | | |
Collapse
|
22
|
Abstract
Inverse agonism is emerging as a new endogenous principle for receptor regulation. Agouti-related protein (AgRP), following its release in the brain, stimulates food intake. AgRP binds to brain melanocortin receptors, which are involved in the regulation of body weight. In addition to antagonizing the effects of the melanocortin receptor agonist alpha-melanocyte-stimulating hormone (alpha-MSH), AgRP suppresses the constitutive activity of melanocortin MC(3) and MC(4) receptors, which characterizes AgRP as an inverse agonist rather than a neutral antagonist. The balance between the activity of AgRP-containing neurons and alpha-MSH-containing neurons determines the extent of activation of melanocortin receptors in neurons onto which they project. The identification of AgRP as an endogenous inverse agonist provides physiological relevance to inverse agonism in the control of body weight.
Collapse
Affiliation(s)
- Roger A H Adan
- Rudolf Magnus Institute of Neuroscience, Department of Pharmacology and Anatomy, University Medical Center, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands.
| | | |
Collapse
|
23
|
Affiliation(s)
- Jodie M. Jawor
- Department of Biology, University of Dayton, Dayton, Ohio 45469-2320, USA
| | - Randall Breitwisch
- Department of Biology, University of Dayton, Dayton, Ohio 45469-2320, USA
| |
Collapse
|
24
|
Nijenhuis WAJ, Kruijtzer JAW, Wanders N, Vrinten DH, Garner KM, Schaaper WMM, Meloen RH, Gispen WH, Liskamp RM, Adan RAH. Discovery and in vivo evaluation of new melanocortin-4 receptor-selective peptides. Peptides 2003; 24:271-80. [PMID: 12668212 DOI: 10.1016/s0196-9781(03)00032-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The melanocortin-4 receptor (MC4R) is involved in several physiological processes, including body weight regulation and grooming behaviour in rats. It has also been suggested that the MC4R mediates the effects of melanocortin ligands on neuropathic pain. Selective compounds are needed to study the exact role of the MC4R in these different processes. We describe here the development and evaluation of new melanocortin compounds that are selective for the MC4R as compared with the other centrally expressed receptors, MC3R and MC5R. First, a library of 18 peptides, in which a melanocortin-based sequence was systematically point-mutated, was screened for binding to and activity on the MC3R, MC4R and MC5R. Compound Ac-Nle-Gly-Lys-D-Phe-Arg-Trp-Gly-NH(2) (JK1) appeared to be the most selective MC4R compound, based on affinity. This compound is 90- and 110-fold selective for the MC4R as compared to the MC3R and MC5R, respectively. Subsequent modification of JK1 yielded compound Ac-Nle-Gly-Lys-D-Nal(2)-Arg-Trp-Gly-NH(2) (JK7)(,) a selective MC4R antagonist with 34-fold MC4R/MC3R and 109-fold MC4R/MC5R selectivity. The compounds were active in vivo as determined in a grooming assay and a model for neuropathic pain in rats. Intravenous (i.v.) injections suggested that they were able to pass the blood-brain barrier.The compounds identified here will be useful in further research on the physiological roles of the MC4R.
Collapse
MESH Headings
- Amino Acid Substitution
- Animals
- Behavior, Animal/drug effects
- Binding Sites
- Binding, Competitive
- Cell Line
- Cell Line, Tumor
- Cold Temperature
- Dose-Response Relationship, Drug
- Grooming/drug effects
- Humans
- Inhibitory Concentration 50
- Male
- Oligopeptides/chemical synthesis
- Oligopeptides/metabolism
- Oligopeptides/pharmacology
- Pain Measurement/drug effects
- Rats
- Rats, Wistar
- Receptor, Melanocortin, Type 4/antagonists & inhibitors
- Receptor, Melanocortin, Type 4/metabolism
- Receptors, Melanocortin/antagonists & inhibitors
- Receptors, Melanocortin/metabolism
- Time Factors
- alpha-MSH/metabolism
- alpha-MSH/pharmacology
Collapse
Affiliation(s)
- Wouter A J Nijenhuis
- Department of Pharmacology, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG, Utrecht, The Netherlands
| | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Hoogduijn MJ, Ancans J, Suzuki I, Estdale S, Thody AJ. Melanin-concentrating hormone and its receptor are expressed and functional in human skin. Biochem Biophys Res Commun 2002; 296:698-701. [PMID: 12176038 DOI: 10.1016/s0006-291x(02)00932-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this study, we have demonstrated the presence of melanin-concentrating hormone (MCH) and melanin-concentrating hormone receptor (MCHR1) transcripts in human skin. Sequence analysis confirmed that the transcripts of both genes were identical to those previously found in human brain. In culture, endothelial cells showed pro-MCH expression whereas no signal was found in keratinocytes, melanocytes, and fibroblasts. MCHR1 expression was restricted to melanocytes and melanoma cells. Stimulation of cultured human melanocytes with MCH reduced the alpha-MSH-induced increase in cAMP production. Furthermore, the melanogenic actions of alpha-MSH were inhibited by MCH. We propose that the MCH/MCHR1 signalling system is present in human skin and may have a role with the melanocortins in regulating the melanocyte.
Collapse
Affiliation(s)
- Martin J Hoogduijn
- Department of Biomedical Sciences, University of Bradford, Bradford BD7 1DP, UK.
| | | | | | | | | |
Collapse
|
26
|
Tsatmali M, Ancans J, Thody AJ. Melanocyte function and its control by melanocortin peptides. J Histochem Cytochem 2002; 50:125-33. [PMID: 11799132 DOI: 10.1177/002215540205000201] [Citation(s) in RCA: 130] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Melanocytes are cells of neural crest origin. In the human epidermis, they form a close association with keratinocytes via their dendrites. Melanocytes are well known for their role in skin pigmentation, and their ability to produce and distribute melanin has been studied extensively. One of the factors that regulates melanocytes and skin pigmentation is the locally produced melanocortin peptide alpha-MSH. The effects of alpha-MSH on melanogenesis are mediated via the MC-1R and tyrosinase, the rate-limiting enzyme in the melanogenesis pathway. Binding of alpha-MSH to its receptor increases tyrosinase activity and eumelanin production, which accounts for the skin-darkening effect of alpha-MSH. Other alpha-MSH-related melanocortin peptides, such as ACTH1-17 and desacetylated alpha-MSH, are also agonists at the MC-1R and could regulate melanocyte function. Recent evidence shows that melanocytes have other functions in the skin in addition to their ability to produce melanin. They are able to secrete a wide range of signal molecules, including cytokines, POMC peptides, catecholamines, and NO in response to UV irradiation and other stimuli. Potential targets of these secretory products are keratinocytes, lymphocytes, fibroblasts, mast cells, and endothelial cells, all of which express receptors for these signal molecules. Melanocytes may therefore act as important local regulators of a range of skin cells. It has been shown that alpha-MSH regulates NO production from melanocytes, and it is possible that the melanocortins regulate the release of other signalling molecules from melanocytes. Therefore, the melanocortin signaling system is one of the important regulators of skin homeostasis.
Collapse
Affiliation(s)
- Marina Tsatmali
- Department of Biomedical Sciences, University of Bradford, Bradford, United Kingdom
| | | | | |
Collapse
|
27
|
Sviderskaya EV, Hill SP, Balachandar D, Barsh GS, Bennett DC. Agouti signaling protein and other factors modulating differentiation and proliferation of immortal melanoblasts. Dev Dyn 2001; 221:373-9. [PMID: 11500974 DOI: 10.1002/dvdy.1153] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The melanocyte lineage potentially forms an attractive model system for studies in cell differentiation, developmental genetics, cell signaling, and melanoma, because differentiated cells produce the visible pigment melanin. Immortal lines of murine melanoblasts (melanocyte precursors) have been described previously, but induction of differentiation involved a complex culture system with keratinocyte feeder cells. Here we describe conditions for both growth and induced differentiation of the melanoblast line melb-a, without feeder cells, and analyze factors that directly control proliferation and differentiation of these pure melanoblasts. Several active factors are products of developmental and other coat color genes, including stem cell factor (SCF), melanocyte-stimulating hormone (alphaMSH), and agouti signaling protein (ASP), a natural antagonist at the MSH receptor (melanocortin 1 receptor, MC1R) encoded by the agouti gene. A stable analog of alphaMSH (NDP-MSH) stimulated differentiation and inhibited growth. ASP in excess inhibited both effects of NDP-MSH, that is, ASP could inhibit pigmentation and stimulate growth. These effects provide an explanation for the interactions in mice of melanocyte developmental mutations with yellow agouti and Mc1r alleles, and a role for embryonic expression patterns of ASP.
Collapse
Affiliation(s)
- E V Sviderskaya
- Department of Anatomy and Developmental Biology, St George's Hospital Medical School, London, United Kingdom.
| | | | | | | | | |
Collapse
|
28
|
Nijenhuis WA, Oosterom J, Adan RA. AgRP(83-132) acts as an inverse agonist on the human-melanocortin-4 receptor. Mol Endocrinol 2001; 15:164-71. [PMID: 11145747 DOI: 10.1210/mend.15.1.0578] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The central melanocortin (MC) system has been demonstrated to act downstream of leptin in the regulation of body weight. The system comprises alpha-MSH, which acts as agonist, and agouti-related protein (AgRP), which acts as antagonist at the MC3 and MC4 receptors (MC3R and MC4R). This property suggests that MCR activity is tightly regulated and that opposing signals are integrated at the receptor level. We here propose another level of regulation within the melanocortin system by showing that the human (h) MC4R displays constitutive activity in vitro as assayed by adenylyl cyclase (AC) activity. Furthermore, human AgRP(83-132) acts as an inverse agonist for the hMC4R since it was able to suppress constitutive activity of the hMC4R both in intact B16/G4F melanoma cells and membrane preparations. The effect of AgRP(83-132) on the hMC4R was blocked by the MC4R ligand SHU9119. Also the hMC3R and the mouse(m)MC5R were shown to be constitutively active. AgRP(83-132) acted as an inverse agonist on the hMC3R but not on the mMC5R. Thus, AgRP is able to regulate MCR activity independently of alpha-MSH. These findings form a basis to further investigate the relevance of constitutive activity of the MC4R and of inverse agonism of AgRP for the regulation of body weight.
Collapse
Affiliation(s)
- W A Nijenhuis
- Molecular Neuroscience Rudolf Magnus Institute for Neurosciences University Medical Center Utrecht Utrecht, the Netherlands 3584 CG
| | | | | |
Collapse
|
29
|
Wikberg JE, Muceniece R, Mandrika I, Prusis P, Lindblom J, Post C, Skottner A. New aspects on the melanocortins and their receptors. Pharmacol Res 2000; 42:393-420. [PMID: 11023702 DOI: 10.1006/phrs.2000.0725] [Citation(s) in RCA: 257] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Knowledge of melanocortins and their receptors has increased tremendously over the last few years. The cloning of five melanocortin receptors, and the discovery of two endogenous antagonists for these receptors, agouti and agouti-related peptide, have sparked intense interest in the field. Here we give a comprehensive review of the pharmacology, physiology and molecular biology of the melanocortins and their receptors. In particular, we review the roles of the melanocortins in the immune system, behaviour, feeding, the cardiovascular system and melanoma. Moreover, evidence is discussed suggesting that while many of the actions of the melanocortins are mediated via melanocortin receptors, some appear to be mediated via mechanisms distinct from melanocortin receptors.
Collapse
Affiliation(s)
- J E Wikberg
- Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Box 591 BMC, SE751 24, Sweden.
| | | | | | | | | | | | | |
Collapse
|
30
|
Virador VM, Santis C, Furumura M, Kalbacher H, Hearing VJ. Bioactive motifs of agouti signal protein. Exp Cell Res 2000; 259:54-63. [PMID: 10942578 DOI: 10.1006/excr.2000.4975] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The switch between the synthesis of eu- and pheomelanins is modulated by the interaction of two paracrine signaling molecules, alpha-melanocyte stimulating hormone (MSH) and agouti signal protein (ASP), which interact with melanocytes via the MSH receptor (MC1R). Comparison of the primary sequence of ASP with the known MSH pharmacophore provides no suggestion about the putative bioactive domain(s) of ASP. To identify such bioactive motif(s), we synthesized 15-mer peptides that spanned the primary sequence of ASP and determined their effects on the melanogenic activities of murine melanocytes. Northern and Western blotting were used, together with chemical analysis of melanins and enzymatic assays, to identify three distinct bioactive regions of ASP that down-regulate eumelanogenesis. The decrease in eumelanin production was mediated by down-regulation of mRNA levels for tyrosinase and other melanogenic enzymes, as occurs in vivo, and these effects were comparable to those elicited by intact recombinant ASP. Shorter peptides in those motifs were synthesized and their effects on melanogenesis were further investigated. The amino acid arginine, which is present in the MSH peptide pharmacophore (HFRW), is also in the most active domain of ASP (KVARP). Our data suggest that lysines and an arginine (in motifs such as KxxxxKxxR or KxxRxxxxK) are important for the bioactivity of ASP. Identification of the specific ASP epitope that interacts with the MC1R has potential pharmacological applications in treating dysfunctions of skin pigmentation.
Collapse
Affiliation(s)
- V M Virador
- Laboratory of Cell Biology, National Cancer Institute, Bethesda, Maryland, 20892, USA
| | | | | | | | | |
Collapse
|
31
|
alpha-Melanocyte-stimulating hormone is contained in nerve terminals innervating thyrotropin-releasing hormone-synthesizing neurons in the hypothalamic paraventricular nucleus and prevents fasting-induced suppression of prothyrotropin-releasing hormone gene expression. J Neurosci 2000. [PMID: 10662844 DOI: 10.1523/jneurosci.20-04-01550.2000] [Citation(s) in RCA: 205] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The hypothalamic arcuate nucleus has an essential role in mediating the homeostatic responses of the thyroid axis to fasting by altering the sensitivity of prothyrotropin-releasing hormone (pro-TRH) gene expression in the paraventricular nucleus (PVN) to feedback regulation by thyroid hormone. Because agouti-related protein (AGRP), a leptin-regulated, arcuate nucleus-derived peptide with alpha-MSH antagonist activity, is contained in axon terminals that terminate on TRH neurons in the PVN, we raised the possibility that alpha-MSH may also participate in the mechanism by which leptin influences pro-TRH gene expression. By double-labeling immunocytochemistry, alpha-MSH-IR axon varicosities were juxtaposed to approximately 70% of pro-TRH neurons in the anterior and periventricular parvocellular subdivisions of the PVN and to 34% of pro-TRH neurons in the medial parvocellular subdivision, establishing synaptic contacts both on the cell soma and dendrites. All pro-TRH neurons receiving contacts by alpha-MSH-containing fibers also were innervated by axons containing AGRP. The intracerebroventricular infusion of 300 ng of alpha-MSH every 6 hr for 3 d prevented fasting-induced suppression of pro-TRH in the PVN but had no effect on AGRP mRNA in the arcuate nucleus. alpha-MSH also increased circulating levels of free thyroxine (T4) 2.5-fold over the levels in fasted controls, but free T4 did not reach the levels in fed controls. These data suggest that alpha-MSH has an important role in the activation of pro-TRH gene expression in hypophysiotropic neurons via either a mono- and/or multisynaptic pathway to the PVN, but factors in addition to alpha-MSH also contribute to the mechanism by which leptin administration restores thyroid hormone levels to normal in fasted animals.
Collapse
|
32
|
Barrenäs ML, Holgers KM. Ototoxic Interaction Between Noise and Pheomelanin: Distortion Product Otoacoustic Emissions After Acoustical Trauma in Chloroquine-Treated Red, Black, and Albino Guinea Pigs: Interaction Ototóxics entre el Ruido y la feomelanina: Emisiones Otoacústicas por Productos de Distorsión Posteriores a Trauma Acústico en Cobayos Rojos, Negros y Albinos tratados con Cloroquina. Int J Audiol 2000. [DOI: 10.3109/00206090009073087] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
33
|
Abstract
It has long been known that a large number of POMC-related peptides are found in skin. In this introduction I describe the formation of POMC-derived peptides in various tissues to indicate that processing is largely tissue-dependent. I focus on the peptides from the N-terminal fragment, such as gamma-MSH, ACTH and alpha-MSH, and beta-lipopropin as well as beta-endorphin. I touch on the factors that control the synthesis of the various peptides, which are now numerous and varied, and again are tissue specific. The biologic activity of the peptides generated from POMC are described in relation to their possible action in skin. In addition, I describe a new class of peptides induced in skin following injury and which are of great interest.
Collapse
Affiliation(s)
- S Solomon
- Department of Medicine and Biochemistry, McGill University, Montreal, Quebec, Canada.
| |
Collapse
|
34
|
Thody AJ, Graham A. Does alpha-MSH have a role in regulating skin pigmentation in humans? PIGMENT CELL RESEARCH 1998; 11:265-74. [PMID: 9877097 DOI: 10.1111/j.1600-0749.1998.tb00735.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Over the years there has been much debate as to whether alpha-MSH has a role as a pigmentary hormone in humans. There are two main reasons for this. First, despite the observations in the 1960s that alpha-MSH increased skin darkening in humans, there are reports that the peptide has no effect on melanogenesis in cultured human melanocytes. Second, the human pituitary, unlike that of most mammals, secretes very little alpha-MSH and circulatory levels of the peptide in humans are extremely low. However, there is now evidence from several groups that alpha-MSH is capable of stimulating melanogenesis in cultured human melanocytes. Rather than producing an overall increase in melanin production, it appears that the peptide acts specifically to increase the synthesis of eumelanin. Such an action could well explain the previously observed skin darkening effects of alpha-MSH. It is also now known that alpha-MSH is not produced exclusively in the pituitary but has been found at numerous sites, including the skin where it is produced by several cell types. Related Proopiomelanocortin (POMC) peptides such as ACTH are also produced in human skin. The ACTH peptides act at the same receptor (MC-1) as alpha-MSH and certain of these would appear to be more potent than alpha-MSH in stimulating melanogenesis. The ACTH peptides are also present in greater amounts than alpha-MSH in human epidermis and it is likely that they play an important role in regulating pigmentary responses. These POMC peptides are released from keratinocytes in response to ultraviolet radiation (UVR) and it has been proposed that they serve as paracrine factors in mediating UV induced pigmentation. Their production by keratinocytes could therefore be critical in determining pigmentary responses and any changes in the availability of these POMC peptides might explain the variations in tanning ability seen in different individuals. However, the possibility that tanning ability is also dependent upon differences at the level of the MC-1 receptor cannot be ruled out and it has been suggested that an inability to tan may depend upon the presence of non-functional changes at the MC-1 receptor. alpha-MSH does, of course, affect human melanocytes in several ways and its stimulation of melanogenesis could be the consequence of some other fundamental action in the melanocyte. The peptide also has many other target sites in the skin and while it may have a role in regulating skin pigmentation in humans, it should not be viewed solely as a pigmentary peptide. alpha-MSH clearly has many different actions and its primary role in the skin may be to maintain homeostasis.
Collapse
Affiliation(s)
- A J Thody
- Department of Dermatology, Medical School, University of Newcastle upon Tyne, United Kingdom
| | | |
Collapse
|
35
|
Aberdam E, Bertolotto C, Sviderskaya EV, de Thillot V, Hemesath TJ, Fisher DE, Bennett DC, Ortonne JP, Ballotti R. Involvement of microphthalmia in the inhibition of melanocyte lineage differentiation and of melanogenesis by agouti signal protein. J Biol Chem 1998; 273:19560-5. [PMID: 9677380 DOI: 10.1074/jbc.273.31.19560] [Citation(s) in RCA: 121] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In mouse follicular melanocytes, production of eumelanins (brown-black pigments) and pheomelanins (yellow-brownish pigments) is under the control of two intercellular signaling molecules that exert opposite actions, alpha-melanocyte-stimulating hormone (alphaMSH) which preferentially increases the synthesis of eumelanins, and agouti signal protein (ASP) whose expression favors the production of hair containing pheomelanins. In this study, we report that ASP does not only affect mature melanocytes but can also inhibit the differentiation of melanoblasts. We show that both alphaMSH and forskolin promote the differentiation of murine melanoblasts into mature melanocytes and that ASP inhibits this process. We present evidence that the expression of a specific melanogenic transcription factor, microphthalmia, and its binding to an M box regulatory element, is inhibited by ASP. We also show that, in B16 murine melanoma cells, ASP inhibits alphaMSH-stimulated expression of tyrosinase, tyrosine-related proteins 1 and 2 through an inhibition of the transcription activity of their respective promoters. Further, ASP inhibits alphaMSH-induced expression of the microphthalmia gene and reduces the level of microphthalmia in the cells. Our data demonstrate that ASP can regulate both melanoblast differentiation and melanogenesis, pointing out the key role of microphthalmia in the control of these processes.
Collapse
Affiliation(s)
- E Aberdam
- INSERM U385, Biologie et Physiopathologie de la Peau, Faculté de Médecine, 06107 Nice Cedex 2, France
| | | | | | | | | | | | | | | | | |
Collapse
|