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Tripathi N, Bhardwaj N, Kumar S, Jain SK. Phytochemical and Pharmacological Aspects of Psoralen - A Bioactive Furanocoumarin from Psoralea corylifolia Linn. Chem Biodivers 2023; 20:e202300867. [PMID: 37752710 DOI: 10.1002/cbdv.202300867] [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: 06/14/2023] [Revised: 09/25/2023] [Accepted: 09/26/2023] [Indexed: 09/28/2023]
Abstract
Since long ago, medicinal plants have played a vital role in drug discovery. Being blessed and rich in chemovars with diverse scaffolds, they have unique characteristics of evolving based on the need. The World Health Organization also mentions that medicinal plants remain at the center for meeting primary healthcare needs as the population relies on them. The plant-derived natural products have remained an attractive choice for drug development owing to their specific biological functions relevant to human health and also the high degree of potency and specificity they offer. In this context, one such esteemed phytoconstituent with inexplicable biological potential is psoralen, a furanocoumarin. Psoralen was the first constituent isolated from the plant Psoralea corylifolia, commonly known as Bauchi. Despite being a life-saver for psoriasis, vitiligo, and leukoderma, it also showed immense anticancer, anti-inflammatory, and anti-osteoporotic potential. This review brings attention to the possible application of psoralen as an attractive target for rational drug design and medicinal chemistry. It discusses the various methods for the total synthesis of psoralen, its extraction, the pharmacological spectrum of psoralen, and the derivatization done on psoralen.
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Affiliation(s)
- Nancy Tripathi
- Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology BHU, Varanasi, 221005, India
| | - Nivedita Bhardwaj
- Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology BHU, Varanasi, 221005, India
| | - Sanjay Kumar
- Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology BHU, Varanasi, 221005, India
| | - Shreyans K Jain
- Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology BHU, Varanasi, 221005, India
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Gebrie A. The melanocortin receptor signaling system and its role in neuroprotection against neurodegeneration: Therapeutic insights. Ann N Y Acad Sci 2023; 1527:30-41. [PMID: 37526975 DOI: 10.1111/nyas.15048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/02/2023]
Abstract
The melanocortin signaling system consists of the melanocortin peptides, their distinctive receptors, accessory proteins, and endogenous antagonists. Melanocortin peptides are small peptide hormones that have been studied in a variety of physiological and pathological conditions. There are five types of melanocortin receptors, and they are distributed within the central nervous system and in several tissues of the periphery. The G protein-coupled melanocortin receptors typically signal through adenylyl cyclase and other downstream signaling pathways. Depending on the ligand, surface expression of melanocortin receptor, receptor occupancy period, related proteins, the type of cell, and other parameters, the signaling pathways are complicated and pleiotropic. While it is known that all five melanocortin receptors are coupled to Gs, they can also occasionally couple to Gq or Gi. Both direct and indirect neuroprotection are induced by the melanocortin signaling system. Targeting several of the components of the melanocortin signaling system (ligands, receptors, accessory proteins, signaling effectors, and regulators) may provide therapeutic opportunities. Activation of the melanocortin system improves different functional traits in neurodegenerative diseases. There is a potential for additional melanocortin system interventions by interfering with dimerization or dissociation. This review aims to discuss the melanocortin receptor signaling system and its role in neuroprotection, as well as its therapeutic potential.
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Affiliation(s)
- Alemu Gebrie
- Department of Biomedical Sciences, School of Medicine, Debre Markos University, Debre Markos, Ethiopia
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Garrido-Mesa J, Thomas BL, Dodd J, Spana C, Perretti M, Montero-Melendez T. Pro-resolving and anti-arthritic properties of the MC 1 selective agonist PL8177. Front Immunol 2022; 13:1078678. [PMID: 36505403 PMCID: PMC9730523 DOI: 10.3389/fimmu.2022.1078678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 11/07/2022] [Indexed: 11/25/2022] Open
Abstract
Background Melanocortins are peptides endowed with anti-inflammatory and pro-resolving activities. Many of these effects are mediated by the Melanocortin receptor 1 (MC1) as reported in several experimental settings. As such, MC1 can be a viable target for the development of new therapies that mimic endogenous pro-resolving mediators. The aim of this study was to assess the immunopharmacology of a selective MC1 agonist (PL8177) in vitro and in a mouse model of inflammatory arthritis. Methods PL8177 and the natural agonist αMSH were tested for activation of mouse and human Melanocortin receptors (MC1,3,4,5), monitoring cAMP accumulation and ERK1/2 phosphorylation, using transiently transfected HEK293A cells. The anti-inflammatory and pro-resolving effects of PL8177 and αMSH were evaluated using mouse peritoneal Macrophages. Finally, a model of K/BxN serum transfer induced arthritis was used to determine the in vivo potential of PL8177. Results PL8177 activates mouse and human MC1 with apparent EC50 values of 0.01 and 1.49 nM, respectively, using the cAMP accumulation assay. Similar profiles were observed for the induction of ERK phosphorylation (EC50: 0.05 and 1.39 nM). PL8177 displays pro-resolving activity (enhanced Macrophage efferocytosis) and counteracts the inflammatory profile of zymosan-stimulated macrophages, reducing the release of IL-1β, IL-6, TNF-α and CCL-2. In the context of joint inflammation, PL8177 (3mg/kg i.p.) reduces clinical score, paw swelling and incidence of severe disease as well as the recruitment of immune cells into the arthritic joint. Conclusion These results demonstrate that the MC1 agonism with PL8177 affords therapeutic effects in inflammatory conditions including arthritis. Significance Drugs targeting the Melanocortin system have emerged as promising therapeutics for several conditions including inflammation or obesity. Multiple candidates are under clinical development, and some have already reached approval. Here we present the characterization of a novel drug candidate, PL8177, selective for the Melanocortin 1 receptor (MC1), demonstrating its selectivity profile on cAMP and ERK1/2 phosphorylation signaling pathways, of relevance as selective drugs will translate into lesser off-target effect. PL8177 also demonstrated, not only anti-inflammatory activity, but pro-resolving actions due to its ability to enhance efferocytosis (i.e. the phagocytosis of apoptotic cells), endowing this molecule with therapeutic advantages compared to classical anti-inflammatory drugs. Using a mouse model of inflammatory arthritis, the compound demonstrated in vivo efficacy by reducing clinical score, paw swelling and overall disease severity. Taken together, these results present Melanocortin-based therapies, and specifically targeting MC1 receptor, as a promising strategy to manage chronic inflammatory diseases.
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Affiliation(s)
- Jose Garrido-Mesa
- The William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Bethan Lynne Thomas
- The William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - John Dodd
- Palatin Technologies, Inc., Cranbury, NJ, United States
| | - Carl Spana
- Palatin Technologies, Inc., Cranbury, NJ, United States
| | - Mauro Perretti
- The William Harvey Research Institute, Queen Mary University of London, London, United Kingdom,Centre for inflammation and Therapeutic Innovation, Queen Mary University of London, London, United Kingdom
| | - Trinidad Montero-Melendez
- The William Harvey Research Institute, Queen Mary University of London, London, United Kingdom,Centre for inflammation and Therapeutic Innovation, Queen Mary University of London, London, United Kingdom,*Correspondence: Trinidad Montero-Melendez,
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Activation of MC1R with BMS-470539 attenuates neuroinflammation via cAMP/PKA/Nurr1 pathway after neonatal hypoxic-ischemic brain injury in rats. J Neuroinflammation 2021; 18:26. [PMID: 33468172 PMCID: PMC7814630 DOI: 10.1186/s12974-021-02078-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 01/07/2021] [Indexed: 12/17/2022] Open
Abstract
Background Microglia-mediated neuroinflammation plays a crucial role in the pathogenesis of hypoxic-ischemic (HI)-induced brain injury. Activation of melanocortin-1 receptor (MC1R) has been shown to exert anti-inflammatory and neuroprotective effects in several neurological diseases. In the present study, we have explored the role of MC1R activation on neuroinflammation and the potential underlying mechanisms after neonatal hypoxic-ischemic brain injury in rats. Methods A total of 169 post-natal day 10 unsexed rat pups were used. HI was induced by right common carotid artery ligation followed by 2.5 h of hypoxia. BMS-470539, a specific selective MC1R agonist, was administered intranasally at 1 h after HI induction. To elucidate the potential underlying mechanism, MC1R CRISPR KO plasmid or Nurr1 CRISPR KO plasmid was administered via intracerebroventricular injection at 48 h before HI induction. Percent brain infarct area, short- and long-term neurobehavioral tests, Nissl staining, immunofluorescence staining, and Western blot were conducted. Results The expression levels of MC1R and Nurr1 increased over time post-HI. MC1R and Nurr1 were expressed on microglia at 48 h post-HI. Activation of MC1R with BMS-470539 significantly reduced the percent infarct area, brain atrophy, and inflammation, and improved short- and long-term neurological deficits at 48 h and 28 days post-HI. MC1R activation increased the expression of CD206 (a microglial M2 marker) and reduced the expression of MPO. Moreover, activation of MC1R with BMS-470539 significantly increased the expression levels of MC1R, cAMP, p-PKA, and Nurr1, while downregulating the expression of pro-inflammatory cytokines (TNFα, IL-6, and IL-1β) at 48 h post-HI. However, knockout of MC1R or Nurr1 by specific CRISPR reversed the neuroprotective effects of MC1R activation post-HI. Conclusions Our study demonstrated that activation of MC1R with BMS-470539 attenuated neuroinflammation, and improved neurological deficits after neonatal hypoxic-ischemic brain injury in rats. Such anti-inflammatory and neuroprotective effects were mediated, at least in part, via the cAMP/PKA/Nurr1 signaling pathway. Therefore, MC1R activation might be a promising therapeutic target for infants with hypoxic-ischemic encephalopathy (HIE). Supplementary Information The online version contains supplementary material available at 10.1186/s12974-021-02078-2.
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Ren Y, Song X, Tan L, Guo C, Wang M, Liu H, Cao Z, Li Y, Peng C. A Review of the Pharmacological Properties of Psoralen. Front Pharmacol 2020; 11:571535. [PMID: 33013413 PMCID: PMC7500444 DOI: 10.3389/fphar.2020.571535] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 08/19/2020] [Indexed: 12/13/2022] Open
Abstract
Psoralen is the principal bioactive component in the dried fruits of Cullen corylifolium (L.) Medik (syn. Psoralea corylifolia L), termed "Buguzhi" in traditional Chinese medicine (TCM). Recent studies have demonstrated that psoralen displays multiple bioactive properties, beneficial for the treatment of osteoporosis, tumors, viruses, bacteria, and inflammation. The present review focuses on the research evidence relating to the properties of psoralen gathered over recent years. Firstly, multiple studies have demonstrated that psoralen exerts strong anti-osteoporotic effects via regulation of osteoblast/osteoclast/chondrocyte differentiation or activation due to the participation in multiple molecular mechanisms of the wnt/β-catenin, bone morphogenetic protein (BMP), inositol-requiring enzyme 1 (IRE1)/apoptosis signaling kinase 1 (ASK1)/c-jun N-terminal kinase (JNK) and the Protein Kinase B(AKT)/activator protein-1 (AP-1) axis, and the expression of miR-488, peroxisome proliferators-activated receptor-gamma (PPARγ), and matrix metalloproteinases (MMPs). In addition, the antitumor properties of psoralen are associated with the induction of ER stress-related cell death via enhancement of PERK: Pancreatic Endoplasmic Reticulum Kinase (PERK)/activating transcription factor (ATF), 78kD glucose-regulated protein (GRP78)/C/EBP homologous protein (CHOP), and 94kD glucose-regulated protein (GRP94)/CHOP signaling, and inhibition of P-glycoprotein (P-gp) or ATPase that overcomes multidrug resistance. Furthermore, multiple articles have shown that the antibacterial, anti-inflammatory and neuroprotective effects of psoralen are a result of its interaction with viral polymerase (Pol), destroying the formation of biofilm, and regulating the activation of tumor necrosis factor alpha (TNF-α), transforming growth factor beta (TGF-β), interleukin 4/5/6/8/12/13 (IL-4/5/6/8/12/13), GATA-3, acetylcholinesterase (AChE), and the hypothalamic-pituitary-adrenal (HPA) axis. Finally, the toxic effects and mechanisms of action of psoralen have also been reviewed.
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Affiliation(s)
- Yali Ren
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Key Laboratory of Standardization for Chinese Herbal Medicine, Ministry of Education, National Key Laboratory Breeding Base of Systematic Research, Development and Utilization of Chinese Medicine Resources, Chengdu, China
| | - Xiaominting Song
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Key Laboratory of Standardization for Chinese Herbal Medicine, Ministry of Education, National Key Laboratory Breeding Base of Systematic Research, Development and Utilization of Chinese Medicine Resources, Chengdu, China
| | - Lu Tan
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Key Laboratory of Standardization for Chinese Herbal Medicine, Ministry of Education, National Key Laboratory Breeding Base of Systematic Research, Development and Utilization of Chinese Medicine Resources, Chengdu, China
| | - Chuanjie Guo
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Key Laboratory of Standardization for Chinese Herbal Medicine, Ministry of Education, National Key Laboratory Breeding Base of Systematic Research, Development and Utilization of Chinese Medicine Resources, Chengdu, China
| | - Miao Wang
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Key Laboratory of Standardization for Chinese Herbal Medicine, Ministry of Education, National Key Laboratory Breeding Base of Systematic Research, Development and Utilization of Chinese Medicine Resources, Chengdu, China
| | - Hui Liu
- Jiangsu Key Laboratory of Drug Discovery for Metabolic Disease, China, Pharmaceutical University, Nanjing, China
| | - Zhixing Cao
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Key Laboratory of Standardization for Chinese Herbal Medicine, Ministry of Education, National Key Laboratory Breeding Base of Systematic Research, Development and Utilization of Chinese Medicine Resources, Chengdu, China
| | - Yuzhi Li
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Key Laboratory of Standardization for Chinese Herbal Medicine, Ministry of Education, National Key Laboratory Breeding Base of Systematic Research, Development and Utilization of Chinese Medicine Resources, Chengdu, China
| | - Cheng Peng
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Key Laboratory of Standardization for Chinese Herbal Medicine, Ministry of Education, National Key Laboratory Breeding Base of Systematic Research, Development and Utilization of Chinese Medicine Resources, Chengdu, China
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Xu W, Mo J, Ocak U, Travis ZD, Enkhjargal B, Zhang T, Wu P, Peng J, Li T, Zuo Y, Shao A, Tang J, Zhang J, Zhang JH. Activation of Melanocortin 1 Receptor Attenuates Early Brain Injury in a Rat Model of Subarachnoid Hemorrhage viathe Suppression of Neuroinflammation through AMPK/TBK1/NF-κB Pathway in Rats. Neurotherapeutics 2020; 17:294-308. [PMID: 31486022 PMCID: PMC7007470 DOI: 10.1007/s13311-019-00772-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Neuroinflammation plays a vital role in early brain injury (EBI) following subarachnoid hemorrhage (SAH). The hypothesis of this study was that activation of melanocortin 1 receptor (MC1R) with BMS-470539 attenuates EBI by suppression of neuroinflammation after SAH. We utilized BMS-470539, MSG-606, and MRT-68601 to verify the neuroprotective effects of MC1R. We evaluated brain water content, short-term and long-term neurobehavior after SAH. Western blotting and immunofluorescence staining were utilized to assess the changes of protein levels. The results of western blotting suggested that the expressions of MC1R, phosphorylated-adenosine monophosphate-activated protein kinase (p-AMPK), and phosphorylated-TANK binding kinase 1 (p-TBK1) were increased and reached their peak points at 24 h following SAH. Moreover, BMS-470539 treatment notably attenuated neurological deficits caused by SAH, and also notably improved long-term spatial learning and memory abilities after SAH. The underlying mechanisms of the neuroprotection of BMS-470539 involved the suppression of microglia activation, promotion of CD206+ microglia transformation and reduction of neutrophil infiltration by increasing the levels of p-AMPK and p-TBK1 while decreasing the levels of NF-κB, IL-1β, and TNFα. The neuroprotective effects of BMS-470539 were significantly abolished by MSG-606 and MRT-68601. The activation of MC1R with BMS-470539 notably attenuates EBI after SAH by suppression of microglial activation and neutrophil infiltration via the AMPK/TBK1/NF-κB signaling pathway.
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Affiliation(s)
- Weilin Xu
- Department of Neurosurgery, The second Affiliated Hospital, Zhejiang University School of Medicine, 88 Jiefang Rd, Hangzhou, 310009, Zhejiang, China
- Department of Physiology & Pharmacology, Loma Linda University, Loma Linda, CA, 92350, USA
| | - Jun Mo
- Department of Neurosurgery, The second Affiliated Hospital, Zhejiang University School of Medicine, 88 Jiefang Rd, Hangzhou, 310009, Zhejiang, China
- Department of Neurosurgery, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, 88 Jiefang Rd, Hangzhou, 310009, Zhejiang, China
| | - Umut Ocak
- Department of Physiology & Pharmacology, Loma Linda University, Loma Linda, CA, 92350, USA
| | - Zachary D Travis
- Department of Earth and Biological Sciences, Loma Linda University, Loma Linda, CA, 92350, USA
| | - Budbazar Enkhjargal
- Department of Physiology & Pharmacology, Loma Linda University, Loma Linda, CA, 92350, USA
| | - Tongyu Zhang
- Department of Physiology & Pharmacology, Loma Linda University, Loma Linda, CA, 92350, USA
| | - Pei Wu
- Department of Physiology & Pharmacology, Loma Linda University, Loma Linda, CA, 92350, USA
| | - Jianhua Peng
- Department of Physiology & Pharmacology, Loma Linda University, Loma Linda, CA, 92350, USA
| | - Tao Li
- Department of Physiology & Pharmacology, Loma Linda University, Loma Linda, CA, 92350, USA
| | - Yuchun Zuo
- Department of Physiology & Pharmacology, Loma Linda University, Loma Linda, CA, 92350, USA
| | - Anwen Shao
- Department of Neurosurgery, The second Affiliated Hospital, Zhejiang University School of Medicine, 88 Jiefang Rd, Hangzhou, 310009, Zhejiang, China
| | - Jiping Tang
- Department of Physiology & Pharmacology, Loma Linda University, Loma Linda, CA, 92350, USA
| | - Jianmin Zhang
- Department of Neurosurgery, The second Affiliated Hospital, Zhejiang University School of Medicine, 88 Jiefang Rd, Hangzhou, 310009, Zhejiang, China.
- Brain Research Institute, Zhejiang University, Hangzhou, 310009, Zhejiang, China.
| | - John H Zhang
- Department of Physiology & Pharmacology, Loma Linda University, Loma Linda, CA, 92350, USA.
- Department of Neurosurgery, Loma Linda University, Loma Linda, CA, 92350, USA.
- Department of Anesthesiology, Loma Linda University, Loma Linda, CA, 92350, USA.
- Department of Physiology and Pharmacology, Loma Linda University, Risley Hall, Room 219, 11041 Campus St, Loma Linda, CA, 92354, USA.
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Moscowitz AE, Asif H, Lindenmaier LB, Calzadilla A, Zhang C, Mirsaeidi M. The Importance of Melanocortin Receptors and Their Agonists in Pulmonary Disease. Front Med (Lausanne) 2019; 6:145. [PMID: 31316990 PMCID: PMC6610340 DOI: 10.3389/fmed.2019.00145] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 06/10/2019] [Indexed: 12/13/2022] Open
Abstract
Melanocortin agonists are ancient neuropeptides that have steroidogenesis and anti-inflammatory properties. They activate melanocortin receptors (MCR), a family of five seven-transmembrane G-protein coupled receptors. MC1R and MC3R are mainly involved in immunomodulatory effects. Adrenocorticotropin hormone (ACTH) and alpha-Melanocortin stimulating hormone (α-MSH) reduce pro-inflammatory cytokines in several pulmonary inflammatory disorders including asthma, sarcoidosis, and the acute respiratory distress syndrome. They have also been shown to reduce fibrogenesis in animal models with pulmonary fibrosis. By understanding the functions of MCR in macrophages, T-helper cell type 1, and T-helper cell type 17, we may uncover the mechanism of action of melanocortin agonists in sarcoidosis. Further translational and clinical research is needed to define the role of ACTH and α-MSH in pulmonary diseases.
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Affiliation(s)
| | - Huda Asif
- Division of Pulmonary and Critical Care, University of Miami, Miami, FL, United States
| | | | - Andrew Calzadilla
- Division of Pulmonary and Critical Care, University of Miami, Miami, FL, United States
| | - Chongxu Zhang
- Section of Pulmonary, Miami VA Healthcare System, Miami, FL, United States
| | - Mehdi Mirsaeidi
- Division of Pulmonary and Critical Care, University of Miami, Miami, FL, United States.,Section of Pulmonary, Miami VA Healthcare System, Miami, FL, United States
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Jang EA, Kim JY, Tin TD, Song JA, Lee SH, Kwak SH. The effects of BMS-470539 on lipopolysaccharide-induced acute lung injury. Acute Crit Care 2019; 34:133-140. [PMID: 31723918 PMCID: PMC6786663 DOI: 10.4266/acc.2019.00507] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 05/24/2019] [Accepted: 05/25/2019] [Indexed: 12/12/2022] Open
Abstract
Background Overactivation of inflammatory cells, including macrophages and neutrophils, is associated with acute lung injury. BMS-470539 is a selective agonist of melanocortin 1 receptor, which triggers the inhibition of proinflammatory responses, suppressing neutrophil infiltration and protecting tissue. This study evaluated the effects of BMS-470539 on lipopolysaccharide-induced acute lung injury in a mouse model. Methods Mice received a subcutaneous injection of saline or BMS-470539 (18.47 mg/kg) 1 hour before an intratracheal injection of saline or lipopolysaccharide (20 μg). Mice were sacrificed to analyze the severity of pulmonary edema (lung wet-to-dry weight [W/D] ratio) and inflammatory responses (level of leukocytes, polymorphonuclear neutrophils [PMNs] and tumor necrosis factor alpha [TNF-α] in bronchoalveolar lavage fluid [BALF]), and neutrophil infiltration (myeloperoxidase activity). TNF-α activation was also measured in neutrophils from bone marrow. Survival was investigated in a second-hit sepsis mouse model. Results BMS-470539 improved sepsis-induced pulmonary edema, as demonstrated by a decreased W/D ratio (5.76%±0.83% to 3.81%±0.86%, P<0.05). The inflammatory response also improved, as shown by decreased levels of leukocytes (551±116 to 357±86×10²/mm³, P<0.05), PMNs (51.52%±16.23% to 18.41%±7.25%, P<0.01), and TNF-α (550±338 to 128±52 pg/ml, P<0.01) in the BALF. BMS-470539 also improved the inflammatory response, as shown by TNF-α levels (850±158 to 423±59 pg/ml, P<0.01) in neutrophils. BMS-470539 downregulated neutrophil infiltration in the lung (myeloperoxidase: 654±98 to 218±89 U/g, P<0.001). Lastly, BMS improved the survival rate (0% to 70%, P<0.01) in a mice multiple organ failure model. Conclusions BMS-470539 improved lipopolysaccharide-induced acute lung injury and mortality in mice by affecting the inflammatory response.
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Affiliation(s)
- Eun-A Jang
- Department of Anesthesiology and Pain Medicine, Chonnam National University Medical School and Hospital, Gwangju, Korea
| | - Jin-Young Kim
- Department of Anesthesiology and Pain Medicine, Chonnam National University Medical School and Hospital, Gwangju, Korea
| | - Tran Duc Tin
- Brain Korea 21 Project, Center for Creative Biomedical Scientists at Chonnam National University, Gwangju, Korea
| | - Ji-A Song
- Department of Anesthesiology and Pain Medicine, Chonnam National University Medical School and Hospital, Gwangju, Korea
| | - Seong-Heon Lee
- Department of Anesthesiology and Pain Medicine, Chonnam National University Medical School and Hospital, Gwangju, Korea
| | - Sang-Hyun Kwak
- Department of Anesthesiology and Pain Medicine, Chonnam National University Medical School and Hospital, Gwangju, Korea.,Brain Korea 21 Project, Center for Creative Biomedical Scientists at Chonnam National University, Gwangju, Korea
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Li J, Chen W, Wu S, Ma T, Jiang H, Zhang Q. Differential expression of MC1R gene in Liaoning Cashmere goats with different coat colors. Anim Biotechnol 2019; 30:273-278. [DOI: 10.1080/10495398.2018.1485681] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- JianPing Li
- College of Animal Science and Technology, Jilin Agricultural Science and Technology University, Jilin, China
| | - Wei Chen
- College of Veterinary Medicine, Jilin University, Changchun, China
| | - SuFang Wu
- College of Veterinary Medicine, Jilin University, Changchun, China
| | - Tao Ma
- College of Veterinary Medicine, Jilin University, Changchun, China
| | - HuaiZhi Jiang
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - QiaoLing Zhang
- College of Veterinary Medicine, Jilin University, Changchun, China
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Dib L, San-Jose LM, Ducrest AL, Salamin N, Roulin A. Selection on the Major Color Gene Melanocortin-1-Receptor Shaped the Evolution of the Melanocortin System Genes. Int J Mol Sci 2017; 18:ijms18122618. [PMID: 29206201 PMCID: PMC5751221 DOI: 10.3390/ijms18122618] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 11/28/2017] [Accepted: 11/29/2017] [Indexed: 12/20/2022] Open
Abstract
Modular genetic systems and networks have complex evolutionary histories shaped by selection acting on single genes as well as on their integrated function within the network. However, uncovering molecular coevolution requires the detection of coevolving sites in sequences. Detailed knowledge of the functions of each gene in the system is also necessary to identify the selective agents driving coevolution. Using recently developed computational tools, we investigated the effect of positive selection on the coevolution of ten major genes in the melanocortin system, responsible for multiple physiological functions and human diseases. Substitutions driven by positive selection at the melanocortin-1-receptor (MC1R) induced more coevolutionary changes on the system than positive selection on other genes in the system. Contrarily, selection on the highly pleiotropic POMC gene, which orchestrates the activation of the different melanocortin receptors, had the lowest coevolutionary influence. MC1R and possibly its main function, melanin pigmentation, seems to have influenced the evolution of the melanocortin system more than functions regulated by MC2-5Rs such as energy homeostasis, glucocorticoid-dependent stress and anti-inflammatory responses. Although replication in other regulatory systems is needed, this suggests that single functional aspects of a genetic network or system can be of higher importance than others in shaping coevolution among the genes that integrate it.
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Affiliation(s)
- Linda Dib
- Department of Ecology and Evolution, Biophore, University of Lausanne, 1015 Lausanne, Switzerland.
- Laboratoire de Recherche en Neuroimagerie, Centre Hospitalier Universitaire Vaudois, 1015 Lausanne, Switzerland.
| | - Luis M San-Jose
- Department of Ecology and Evolution, Biophore, University of Lausanne, 1015 Lausanne, Switzerland.
| | - Anne-Lyse Ducrest
- Department of Ecology and Evolution, Biophore, University of Lausanne, 1015 Lausanne, Switzerland.
| | - Nicolas Salamin
- Department of Ecology and Evolution, Biophore, University of Lausanne, 1015 Lausanne, Switzerland.
- Swiss Institute of Bioinformatics, Quartier Sorge, 1015 Lausanne, Switzerland.
- Department of Computational Biology, University of Lausanne, Rue du Bugnon 27, 1011 Lausanne, Switzerland.
| | - Alexandre Roulin
- Department of Ecology and Evolution, Biophore, University of Lausanne, 1015 Lausanne, Switzerland.
- Department of Computational Biology, University of Lausanne, Rue du Bugnon 27, 1011 Lausanne, Switzerland.
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Qiang X, Liotta AS, Shiloach J, Gutierrez JC, Wang H, Ochani M, Ochani K, Yang H, Rabin A, LeRoith D, Lesniak MA, Böhm M, Maaser C, Kannengiesser K, Donowitz M, Rabizadeh S, Czura CJ, Tracey KJ, Westlake M, Zarfeshani A, Mehdi SF, Danoff A, Ge X, Sanyal S, Schwartz GJ, Roth J. New melanocortin-like peptide of E. coli can suppress inflammation via the mammalian melanocortin-1 receptor (MC1R): possible endocrine-like function for microbes of the gut. NPJ Biofilms Microbiomes 2017; 3:31. [PMID: 29152323 PMCID: PMC5684143 DOI: 10.1038/s41522-017-0039-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 08/24/2017] [Accepted: 10/10/2017] [Indexed: 12/11/2022] Open
Abstract
E. coli releases a 33 amino acid peptide melanocortin-like peptide of E. coli (MECO-1) that is identical to the C-terminus of the E. coli elongation factor-G (EF-G) and has interesting similarities to two prominent mammalian melanocortin hormones, alpha-melanocyte-stimulating hormone (alpha-MSH) and adrenocorticotropin (ACTH). Note that MECO-1 lacks HFRW, the common pharmacophore of the known mammalian melanocortin peptides. MECO-1 and the two hormones were equally effective in severely blunting release of cytokines (HMGB1 and TNF) from macrophage-like cells in response to (i) endotoxin (lipopolysaccharide) or (ii) pro-inflammatory cytokine HMGB-1. The in vitro anti-inflammatoty effects of MECO-1 and of alpha-MSH were abrogated by (i) antibody against melanocortin-1 receptor (MC1R) and by (ii) agouti, an endogenous inverse agonist of MC1R. In vivo MECO-1 was even more potent than alpha-MSH in rescuing mice from death due to (i) lethal doses of LPS endotoxin or (ii) cecal ligation and puncture, models of sterile and infectious sepsis, respectively.
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Affiliation(s)
- Xiaoling Qiang
- Laboratory of Diabetes and Diabetes Related Research, US, USA
- Feinstein Institute for Medical Research, Northwell Health System, Manhasset, NY USA
- Hofstra Northwell School of Medicine, Hempstead, NY USA
| | | | | | | | - Haichao Wang
- Feinstein Institute for Medical Research, Northwell Health System, Manhasset, NY USA
- Department of Emergency Medicine, Manhasset, NY USA
| | - Mahendar Ochani
- Feinstein Institute for Medical Research, Northwell Health System, Manhasset, NY USA
| | - Kanta Ochani
- Feinstein Institute for Medical Research, Northwell Health System, Manhasset, NY USA
| | - Huan Yang
- Feinstein Institute for Medical Research, Northwell Health System, Manhasset, NY USA
| | - Aviva Rabin
- Laboratory of Diabetes and Diabetes Related Research, US, USA
- Feinstein Institute for Medical Research, Northwell Health System, Manhasset, NY USA
| | - Derek LeRoith
- Icahn School of Medicine at Mount Sinai, New York, NY USA
| | | | | | | | | | - Mark Donowitz
- Johns Hopkins University School of Medicine, Baltimore, MD USA
| | | | - Christopher J. Czura
- Feinstein Institute for Medical Research, Northwell Health System, Manhasset, NY USA
- Hofstra Northwell School of Medicine, Hempstead, NY USA
| | - Kevin J. Tracey
- Feinstein Institute for Medical Research, Northwell Health System, Manhasset, NY USA
- Hofstra Northwell School of Medicine, Hempstead, NY USA
| | - Mark Westlake
- Laboratory of Diabetes and Diabetes Related Research, US, USA
- Feinstein Institute for Medical Research, Northwell Health System, Manhasset, NY USA
| | - Aida Zarfeshani
- Laboratory of Diabetes and Diabetes Related Research, US, USA
- Feinstein Institute for Medical Research, Northwell Health System, Manhasset, NY USA
| | - Syed F. Mehdi
- Laboratory of Diabetes and Diabetes Related Research, US, USA
- Feinstein Institute for Medical Research, Northwell Health System, Manhasset, NY USA
| | - Ann Danoff
- Perelman School of Medicine at the University of Pennsylvania, Philadelphia, USA
| | - Xueliang Ge
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Suparna Sanyal
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | | | - Jesse Roth
- Laboratory of Diabetes and Diabetes Related Research, US, USA
- Feinstein Institute for Medical Research, Northwell Health System, Manhasset, NY USA
- Hofstra Northwell School of Medicine, Hempstead, NY USA
- Albert Einstein College of Medicine, Bronx, NY USA
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12
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Anturaniemi J, Uusitalo L, Hielm-Björkman A. Environmental and phenotype-related risk factors for owner-reported allergic/atopic skin symptoms and for canine atopic dermatitis verified by veterinarian in a Finnish dog population. PLoS One 2017; 12:e0178771. [PMID: 28570617 PMCID: PMC5453595 DOI: 10.1371/journal.pone.0178771] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Accepted: 05/18/2017] [Indexed: 01/30/2023] Open
Abstract
The aim of this cross-sectional study was to observe whether environmental factors and phenotypic traits are associated with owner-reported skin problems and with veterinary diagnosed canine atopic dermatitis (CAD). Data were collected using the validated online DOGRISK questionnaire. Out of the data that the questionnaire provides for analysis, focus was first turned towards addressing questions regarding 'Atopy/allergy (skin symptoms)' using a total of 8643 dogs: 1585 dogs with owner-reported allergic/atopic skin symptoms and 7058 dogs without. A subsequent analysis compared dogs with veterinary-verified CAD (n = 322) as a case group against the 7058 dogs without owner-reported skin symptoms. The association between 21 factors related to the environment, canine phenotypes and breed groups within both populations were analysed using univariable and multivariable logistic regression. The environmental factors that showed a significant inverse association with the risk of owner-reported allergic/atopic skin symptoms were as following: whether the dog was living in a detached house, whether there were other dogs in the household, and whether the dog was born in the current household. Having over 50% white colour in the coat and living in an extremely clean household were significantly associated with an increased risk of owner-reported allergic/atopic skin symptoms. The five breeds demonstrating the highest proportion of owner-reported allergic/atopic skin symptoms were West Highland white terrier, Boxer, English bulldog, Dalmatian and French bulldog. The Fédération Cynologique Internationale dog breed groups 3 (Terriers) and 6 (Scent hounds and related breeds) showed a significantly higher risk for owner-reported allergic/atopic skin symptoms than mixed breed dogs. In the second population, the inverse association was observed between the risk of CAD and the presence of other dogs in the household, and whether the dog had been born in the current household. The results indicate that some environmental factors and canine phenotypes are associated with CAD and owner-reported skin symptoms, but they still do not prove causality.
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Affiliation(s)
- Johanna Anturaniemi
- Faculty of Veterinary Medicine, Department of Equine and Small Animal Medicine, University of Helsinki, Helsinki, Finland
- Faculty of Agriculture and Forestry, Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland
| | - Liisa Uusitalo
- Faculty of Veterinary Medicine, Department of Equine and Small Animal Medicine, University of Helsinki, Helsinki, Finland
| | - Anna Hielm-Björkman
- Faculty of Veterinary Medicine, Department of Equine and Small Animal Medicine, University of Helsinki, Helsinki, Finland
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13
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Kleiner S, Braunstahl GJ, Rüdrich U, Gehring M, Eiz-Vesper B, Luger TA, Steelant B, Seys SF, Kapp A, Böhm M, Hellings PW, Raap U. Regulation of melanocortin 1 receptor in allergic rhinitis in vitro and in vivo. Clin Exp Allergy 2016; 46:1066-74. [PMID: 27196703 DOI: 10.1111/cea.12759] [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: 02/02/2016] [Revised: 04/22/2016] [Accepted: 05/05/2016] [Indexed: 12/17/2022]
Abstract
BACKGROUND α-melanocyte-stimulating hormone (α-MSH) was shown to inhibit allergic airway inflammation and exert suppressive effects on human basophils. OBJECTIVE This study aims to extend our current knowledge on the melanocortin 1 receptor (MC1R) expression in nasal tissue of patients with allergic rhinitis (AR) and functional effects of α-MSH in human basophils especially from patients with allergic rhinitis. METHODS MC1R expression before and after nasal allergen provocation was studied in nasal mucosal tissue of AR patients and in a mouse model of allergic airway inflammation using immunofluorescence. In vitro regulation of the MC1R and CD203c surface expression on whole-blood basophils of patients with AR and controls was assessed with flow cytometry. Functional effects of α-MSH on isolated basophils were analysed regarding apoptosis with flow cytometry and chemotaxis using a Boyden chamber assay. RESULTS We detected an accumulation of MC1R-positive basophils in nasal mucosa tissue of patients with AR 24 h after nasal allergen provocation. Such accumulation was not present in mucosa sections from healthy controls. In mice with allergic airway inflammation, we found a clear accumulation of MC1R-positive basophils in the nasal tissue compared to control mice. MC1R expression was inducible in AR patients and controls by stimulation with anti-IgE. α-MSH inhibited anti-IgE and grass pollen induced upregulation of CD203c, but had no effect on chemotaxis or apoptosis of basophils in vitro. CONCLUSIONS AND CLINICAL RELEVANCE MC1R-positive basophils accumulate in the nasal mucosa of patients with AR after nasal allergen provocation. Since α-MSH suppresses proinflammatory effector functions in human basophils via the MC1R, it constitutes an interesting novel target for modulating the allergic inflammatory response.
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Affiliation(s)
- S Kleiner
- Department of Dermatology and Allergy, Hannover Medical School, Hannover, Germany
| | - G-J Braunstahl
- Department of Pulmonology, Sint Franciscus Gasthuis, Rotterdam, the Netherlands
| | - U Rüdrich
- Department of Dermatology and Allergy, Hannover Medical School, Hannover, Germany
| | - M Gehring
- Department of Dermatology and Allergy, Hannover Medical School, Hannover, Germany
| | - B Eiz-Vesper
- Institute for Transfusion Medicine, Hannover Medical School, Hannover, Germany
| | - T A Luger
- Department of Dermatology, University of Münster, Münster, Germany
| | - B Steelant
- Laboratory of Clinical Immunology, KU Leuven, Leuven, Belgium
| | - S F Seys
- Laboratory of Clinical Immunology, KU Leuven, Leuven, Belgium
| | - A Kapp
- Department of Dermatology and Allergy, Hannover Medical School, Hannover, Germany
| | - M Böhm
- Department of Dermatology, University of Münster, Münster, Germany
| | - P W Hellings
- Laboratory of Clinical Immunology, KU Leuven, Leuven, Belgium
| | - U Raap
- Department of Dermatology and Allergy, Hannover Medical School, Hannover, Germany
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Loram LC, Culp ME, Connolly-Strong EC, Sturgill-Koszycki S. Melanocortin peptides: potential targets in systemic lupus erythematosus. Inflammation 2015; 38:260-71. [PMID: 25323206 PMCID: PMC4312383 DOI: 10.1007/s10753-014-0029-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Systemic lupus erythematosus (SLE) is a systemic autoimmune disease resulting in loss of self-tolerance with multiple organs, such as the kidney, skin, joints, and the central nervous system (CNS), being targeted. Numerous immunosuppressant therapies are currently being used for the treatment of SLE, but their clinical utility is somewhat variable because of the clinical heterogeneity. Melanocortins are a family of peptides derived from the common precursor protein pro-opiomelanocortin. These multifunctional peptides activate five subtypes of melanocortin receptors expressed on immune, skin, muscle, bone, and kidney cells and cells within the CNS. Melanocortin peptides have demonstrated a variety of biologic actions including immunomodulation, melanogenesis, and renoprotection. This review aims to introduce the melanocortin system and explore the mechanisms by which they may be beneficial in diseases such as SLE.
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Affiliation(s)
- Lisa Carole Loram
- Mallinckrodt Pharmaceuticals (formerly Questcor), 26118 Research Road, Hayward, CA, 94545, USA
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15
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Skin transcriptome profiles associated with skin color in chickens. PLoS One 2015; 10:e0127301. [PMID: 26030885 PMCID: PMC4452617 DOI: 10.1371/journal.pone.0127301] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 04/14/2015] [Indexed: 12/20/2022] Open
Abstract
Nutritional and medicinal benefits have been attributed to the consumption of tissues from the black-boned chickens in oriental countries. Lueyang black-boned chicken is one of the native chicken breeds. However, some birds may instead have white or lighter skin, which directly causes economic losses every year. Previous studies of pigmentation have focused on a number of genes that may play important roles in coat color regulation. Illumina2000 sequencing technology was used to catalog the global gene expression profiles in the skin of the Lueyang chicken with white versus black skin. A total of 18,608 unigenes were assembled from the reads obtained from the skin of the white and black chickens. A total of 649 known genes were differentially expressed in the black versus white chickens, with 314 genes that were up regulated and 335 genes that were down-regulated, and a total of 162 novel genes were differentially expressed in the black versus white chickens, consisting of 73 genes that were up-regulated (including 4 highly expressed genes that were expressed exclusively in the skin of the black chickens) and 89 genes that were down-regulated. There were also a total of 8 known coat-color genes expressed in previous studies (ASIP, TYR, KIT, TYRP1, OCA2, KITLG, MITF and MC1R). In this study, 4 of which showed greater expression in the black chickens, and several were up-regulated, such as KIT, ASIP, TYR and OCA2. To our surprise, KITLG, MITF and MC1R showed no significant difference in expression between the black- and white-skinned chickens, and the expression of TYRP1 was not detected in either skin color. The expression of ASIP, TYR, KIT, TYRP1, OCA2, KITLG, MITF and MC1R was validated by real-time quantitative polymerase chain reaction (qPCR), and the results of the qPCR were consistent with the RNA-seq. This study provides several candidate genes that may be associated with the development of black versus white skin. More importantly, the fact that the MC1R gene showed no significant difference in expression between the black and white chickens is of particular interest for future studies that aim to elucidate its functional role in the regulation of skin color.
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Zmijewski MA, Slominski AT. Is Mc1r an important regulator of non-pigmentary responses to UV radiation? Exp Dermatol 2014; 22:790-1. [PMID: 24279915 DOI: 10.1111/exd.12129] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/01/2013] [Indexed: 01/22/2023]
Abstract
MC1R is recognized for its role in the regulation of melanin pigmentation. In addition, many investigators believe that it also plays a crucial role in immunomodulation (immunosuppression) and in melanogenesis-independent protective responses against ultraviolet radiation (UVR). Surprisingly, Wolnicka-Glubisz et al. have shown that loss of function in the MC1R has no effect on inflammatory responses and immunosuppression induced by UVR in C57BL/6 mice as well as on the degree of UVA-induced DNA damage in the epidermis and dermis. These findings, by challenging the existing dogmas on the precise role of MC1R in non-pigmentary responses to the UVR, mandate further research to either validate the presented data or to define to which degree these phenomena are restricted to the C57BL/6 mouse model or are applicable to other species including humans. The alternative target for immunomodulation is represented by MC3R. However, cutaneous expression of MC3R remains to be demonstrated.
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Regulation of melanopsins and Per1 by α -MSH and melatonin in photosensitive Xenopus laevis melanophores. BIOMED RESEARCH INTERNATIONAL 2014; 2014:654710. [PMID: 24959583 PMCID: PMC4052817 DOI: 10.1155/2014/654710] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Revised: 03/27/2014] [Accepted: 03/30/2014] [Indexed: 12/21/2022]
Abstract
α-MSH and light exert a dispersing effect on pigment granules of Xenopus laevis melanophores; however, the intracellular signaling pathways are different. Melatonin, a hormone that functions as an internal signal of darkness for the organism, has opposite effects, aggregating the melanin granules. Because light functions as an important synchronizing signal for circadian rhythms, we further investigated the effects of both hormones on genes related to the circadian system, namely, Per1 (one of the clock genes) and the melanopsins, Opn4x and Opn4m (photopigments). Per1 showed temporal oscillations, regardless of the presence of melatonin or α-MSH, which slightly inhibited its expression. Melatonin effects on melanopsins depend on the time of application: if applied in the photophase it dramatically decreased Opn4x and Opn4m expressions, and abolished their temporal oscillations, opposite to α-MSH, which increased the melanopsins' expressions. Our results demonstrate that unlike what has been reported for other peripheral clocks and cultured cells, medium changes or hormones do not play a major role in synchronizing the Xenopus melanophore population. This difference is probably due to the fact that X. laevis melanophores possess functional photopigments (melanopsins) that enable these cells to primarily respond to light, which triggers melanin dispersion and modulates gene expression.
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