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Kara Ş, Kürekci C, Akcan M. Design and modification of frog skin peptide brevinin-1GHa with enhanced antimicrobial activity on Gram-positive bacterial strains. Amino Acids 2022; 54:1327-1336. [DOI: 10.1007/s00726-022-03189-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 07/08/2022] [Indexed: 11/29/2022]
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Douglas AJ, Hug LA, Katzenback BA. Composition of the North American Wood Frog (Rana sylvatica) Bacterial Skin Microbiome and Seasonal Variation in Community Structure. MICROBIAL ECOLOGY 2021; 81:78-92. [PMID: 32613267 DOI: 10.1007/s00248-020-01550-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 06/22/2020] [Indexed: 06/11/2023]
Abstract
While a number of amphibian skin microbiomes have been characterized, it is unclear how these communities might vary in response to seasonal changes in the environment and the corresponding behaviors that many amphibians exhibit. Given recent studies demonstrating the importance of the skin microbiome in frog innate immune defense against pathogens, investigating how changes in the environment impact the microbial species present will provide a better understanding of conditions that may alter host susceptibility to pathogens in their environment. We sampled the bacterial skin microbiome of North American wood frogs (Rana sylvatica) from two breeding ponds in the spring, along with the bacterial community present in their vernal breeding pools, and frogs from the nearby forest floor in the summer and fall to determine whether community composition differs by sex, vernal pond site, or temporally across season (spring, summer, fall). Taxon relative abundance data reveals a profile of bacterial phyla similar to those previously described on anuran skin, with Proteobacteria, Bacteroidetes, and Actinobacteria dominating the wood frog skin microbiome. Our results indicate that sex had no significant effect on skin microbiota diversity; however, this may be due to our limited female frog sample size. Vernal pool site had a small but significant effect on skin microbiota, but skin-associated communities were more similar to each other than to the communities observed in the frogs' respective pond water. Across seasons, diversity analyses suggest that there are significant differences between the bacterial skin microbiome of frogs from spring and summer/fall groups while the average α-diversity per frog remained consistent. These results illustrate seasonal variation in wood frog skin microbiome structure and highlight the importance of considering temporal trends in an amphibian microbiome, particularly for species whose life history requires recurrent shifts in habitat and behavior.
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Affiliation(s)
- Alexander J Douglas
- Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada
| | - Laura A Hug
- Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada
| | - Barbara A Katzenback
- Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada.
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3
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Pei X, Gong Z, Wu Q, Chen X, Wang L, Ma C, Xi X, Chen T, Shaw C, Zhou M. Characterisation of a novel peptide, Brevinin-1H, from the skin secretion of Amolops hainanensis and rational design of several analogues. Chem Biol Drug Des 2020; 97:273-282. [PMID: 32812694 DOI: 10.1111/cbdd.13779] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 07/15/2020] [Accepted: 08/09/2020] [Indexed: 12/12/2022]
Abstract
As drug-resistant bacteria have become a serious health problem and have caused thousands of deaths, finding new antibiotics has become an urgent research priority. A novel antimicrobial peptide, named Brevinin-1H, was identified in the skin secretion of Amolops hainanensis through 'shotgun' cloning. It has broad-spectrum antimicrobial activity against tested micro-organisms and has anticancer cell activity. To improve its bioactivity and decrease its cytotoxicity, two structural analogues-Brevinin-1Ha and Brevinin-1HY-were designed based on the secondary structure of the natural peptide. Brevinin-1HY, in which tyrosine substituted Pro11 , had similar activity to the natural peptide against Gram-negative bacteria and cancer cells, but showed a dramatic increase in haemolytic activity and cytotoxicity at its minimum inhibitory concentration. Brevinin-1Ha, which transferred the Rana-box from the C-terminal to a central position, had significantly decreased haemolytic activity, but also in antimicrobial and anticancer activity. The present data suggest that increasing the proportion of α-helix structure in an AMP can increase its target micro-organism bioactivity to some extent.
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Affiliation(s)
- Xinjie Pei
- Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast, UK.,School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China
| | - Zijian Gong
- Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast, UK
| | - Qing Wu
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China
| | - Xiaoling Chen
- Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast, UK
| | - Lei Wang
- Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast, UK
| | - Chengbang Ma
- Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast, UK
| | - Xinping Xi
- Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast, UK
| | - Tianbao Chen
- Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast, UK
| | - Chris Shaw
- Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast, UK
| | - Mei Zhou
- Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast, UK
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Helbing CC, Hammond SA, Jackman SH, Houston S, Warren RL, Cameron CE, Birol I. Antimicrobial peptides from Rana [Lithobates] catesbeiana: Gene structure and bioinformatic identification of novel forms from tadpoles. Sci Rep 2019; 9:1529. [PMID: 30728430 PMCID: PMC6365531 DOI: 10.1038/s41598-018-38442-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 12/28/2018] [Indexed: 01/21/2023] Open
Abstract
Antimicrobial peptides (AMPs) exhibit broad-spectrum antimicrobial activity, and have promise as new therapeutic agents. While the adult North American bullfrog (Rana [Lithobates] catesbeiana) is a prolific source of high-potency AMPs, the aquatic tadpole represents a relatively untapped source for new AMP discovery. The recent publication of the bullfrog genome and transcriptomic resources provides an opportune bridge between known AMPs and bioinformatics-based AMP discovery. The objective of the present study was to identify novel AMPs with therapeutic potential using a combined bioinformatics and wet lab-based approach. In the present study, we identified seven novel AMP precursor-encoding transcripts expressed in the tadpole. Comparison of their amino acid sequences with known AMPs revealed evidence of mature peptide sequence conservation with variation in the prepro sequence. Two mature peptide sequences were unique and demonstrated bacteriostatic and bactericidal activity against Mycobacteria but not Gram-negative or Gram-positive bacteria. Nine known and seven novel AMP-encoding transcripts were detected in premetamorphic tadpole back skin, olfactory epithelium, liver, and/or tail fin. Treatment of tadpoles with 10 nM 3,5,3'-triiodothyronine for 48 h did not affect transcript abundance in the back skin, and had limited impact on these transcripts in the other three tissues. Gene mapping revealed considerable diversity in size (1.6-15 kbp) and exon number (one to four) of AMP-encoding genes with clear evidence of alternative splicing leading to both prepro and mature amino acid sequence diversity. These findings verify the accuracy and utility of the bullfrog genome assembly, and set a firm foundation for bioinformatics-based AMP discovery.
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Affiliation(s)
- Caren C Helbing
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, V8P 5C2, Canada.
| | - S Austin Hammond
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, Vancouver, BC, V5Z 4S6, Canada
| | - Shireen H Jackman
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, V8P 5C2, Canada
| | - Simon Houston
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, V8P 5C2, Canada
| | - René L Warren
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, Vancouver, BC, V5Z 4S6, Canada
| | - Caroline E Cameron
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, V8P 5C2, Canada
| | - Inanç Birol
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, Vancouver, BC, V5Z 4S6, Canada
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Varga JFA, Bui-Marinos MP, Katzenback BA. Frog Skin Innate Immune Defences: Sensing and Surviving Pathogens. Front Immunol 2019; 9:3128. [PMID: 30692997 PMCID: PMC6339944 DOI: 10.3389/fimmu.2018.03128] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 12/18/2018] [Indexed: 01/26/2023] Open
Abstract
Amphibian skin is a mucosal surface in direct and continuous contact with a microbially diverse and laden aquatic and/or terrestrial environment. As such, frog skin is an important innate immune organ and first line of defence against pathogens in the environment. Critical to the innate immune functions of frog skin are the maintenance of physical, chemical, cellular, and microbiological barriers and the complex network of interactions that occur across all the barriers. Despite the global decline in amphibian populations, largely as a result of emerging infectious diseases, we understand little regarding the cellular and molecular mechanisms that underlie the innate immune function of amphibian skin and defence against pathogens. In this review, we discuss the structure, cell composition and cellular junctions that contribute to the skin physical barrier, the antimicrobial peptide arsenal that, in part, comprises the chemical barrier, the pattern recognition receptors involved in recognizing pathogens and initiating innate immune responses in the skin, and the contribution of commensal microbes on the skin to pathogen defence. We briefly discuss the influence of environmental abiotic factors (natural and anthropogenic) and pathogens on the immunocompetency of frog skin defences. Although some aspects of frog innate immunity, such as antimicrobial peptides are well-studied; other components and how they contribute to the skin innate immune barrier, are lacking. Elucidating the complex network of interactions occurring at the interface of the frog's external and internal environments will yield insight into the crucial role amphibian skin plays in host defence and the environmental factors leading to compromised barrier integrity, disease, and host mortality.
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Affiliation(s)
- Joseph F A Varga
- Department of Biology, University of Waterloo, Waterloo, ON, Canada
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Al-Attar R, Storey KB. Effects of anoxic exposure on the nuclear factor of activated T cell (NFAT) transcription factors in the stress-tolerant wood frog. Cell Biochem Funct 2018; 36:420-430. [PMID: 30411386 DOI: 10.1002/cbf.3362] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 08/15/2018] [Accepted: 10/03/2018] [Indexed: 11/08/2022]
Abstract
The wood frog, Lithobates sylvaticus (also known as Rana sylvatica), is used for studying natural freeze tolerance. These animals convert 65% to 70% of their total body water into extracellular ice and survive freezing for weeks in winter. Freezing interrupts oxygen delivery to organs; thus, wood frogs limit their ATP usage by depressing their metabolism and redirecting the available energy only to prosurvival processes. Here, we studied the nuclear factor of activated T cell (NFAT) transcription factor family in response to 24-hour anoxia, and 4-hour aerobic recovery in liver and skeletal muscle. Protein expression levels of NFATc1-c4, calcineurin A and glycogen synthase kinase 3β (NFAT regulators), osteopontin, and atrial natriuretic peptide (ANP) (targets of NFATc3 and NFATc4, respectively) were measured by immunoblotting, and the DNA-binding activities of NFATc1-c4 were measured by DNA-protein interaction ELISAs. Results show that NFATc4, calcineurin, and ANP protein expression as well as NFATc4 DNA binding increased during anoxia in liver where calcineurin and ANP protein levels and NFATc4 DNA binding remaining high after aerobic recovery. Anoxia caused a significant increase in NFATc3 protein expression but not DNA-binding activity in muscle. Our results show that anoxia can increase NFATc4 transcriptional activity in liver, leading to the increase in expression of cytoprotective genes in the wood frog. Understanding the molecular mechanisms involved in mediating survival under anoxia/reoxygenation conditions in a naturally stress-tolerant model, such as the wood frog, provides insightful information on the prosurvival regulatory mechanisms involved in combating stress. This information will also further our understanding of metabolic rate depression and answer the question of how frogs tolerate prolonged periods of oxygen deprivation and resume to full function upon recovery without facing any detrimental side effects as other animals would.
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Affiliation(s)
- Rasha Al-Attar
- Institude of Biochemistry and Department of Biology, Carleton University, Ottawa, Canada
| | - Kenneth B Storey
- Institude of Biochemistry and Department of Biology, Carleton University, Ottawa, Canada
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7
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Eskew EA, Shock BC, LaDouceur EEB, Keel K, Miller MR, Foley JE, Todd BD. Gene expression differs in susceptible and resistant amphibians exposed to Batrachochytrium dendrobatidis. ROYAL SOCIETY OPEN SCIENCE 2018; 5:170910. [PMID: 29515828 PMCID: PMC5830717 DOI: 10.1098/rsos.170910] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Chytridiomycosis, the disease caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), has devastated global amphibian biodiversity. Nevertheless, some hosts avoid disease after Bd exposure even as others experience near-complete extirpation. It remains unclear whether the amphibian adaptive immune system plays a role in Bd defence. Here, we describe gene expression in two host species-one susceptible to chytridiomycosis and one resistant-following exposure to two Bd isolates that differ in virulence. Susceptible wood frogs (Rana sylvatica) had high infection loads and mortality when exposed to the more virulent Bd isolate but lower infection loads and no fatal disease when exposed to the less virulent isolate. Resistant American bullfrogs (R. catesbeiana) had high survival across treatments and rapidly cleared Bd infection or avoided infection entirely. We found widespread upregulation of adaptive immune genes and downregulation of important metabolic and cellular maintenance components in wood frogs after Bd exposure, whereas American bullfrogs showed little gene expression change and no evidence of an adaptive immune response. Wood frog responses suggest that adaptive immune defences may be ineffective against virulent Bd isolates that can cause rapid physiological dysfunction. By contrast, American bullfrogs exhibited robust resistance to Bd that is likely attributable, at least in part, to their continued upkeep of metabolic and skin integrity pathways as well as greater antimicrobial peptide expression compared to wood frogs, regardless of exposure. Greater understanding of these defences will ultimately help conservationists manage chytridiomycosis.
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Affiliation(s)
- Evan A. Eskew
- Graduate Group in Ecology, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
- EcoHealth Alliance, 460 West 34th Street – 17th Floor, New York, NY 10001, USA
- Author for correspondence: Evan A. Eskew e-mail:
| | - Barbara C. Shock
- Department of Biology, Lincoln Memorial University, 6965 Cumberland Gap Parkway, Harrogate, TN 37752, USA
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | | | - Kevin Keel
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Michael R. Miller
- Department of Animal Science, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Janet E. Foley
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Brian D. Todd
- Department of Wildlife, Fish, and Conservation Biology, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
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8
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Cramp RL, Franklin CE. Exploring the link between ultraviolet B radiation and immune function in amphibians: implications for emerging infectious diseases. CONSERVATION PHYSIOLOGY 2018; 6:coy035. [PMID: 29992023 PMCID: PMC6022628 DOI: 10.1093/conphys/coy035] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 05/27/2018] [Accepted: 06/07/2018] [Indexed: 05/07/2023]
Abstract
Amphibian populations the world over are under threat of extinction, with as many as 40% of assessed species listed as threatened under IUCN Red List criteria (a significantly higher proportion than other vertebrate group). Amongst the key threats to amphibian species is the emergence of novel infectious diseases, which have been implicated in the catastrophic amphibian population declines and extinctions seen in many parts of the world. The recent emergence of these diseases coincides with increased ambient levels of ultraviolet B radiation (UVBR) due to anthropogenic thinning of the Earth's protective ozone layer, raising questions about potential interactions between UVBR exposure and disease in amphibians. While reasonably well documented in other vertebrate groups (particularly mammals), the immunosuppressive capacity of UVBR and the potential for it to influence disease outcomes has been largely overlooked in amphibians. Herein, we review the evidence for UVBR-associated immune system disruption in amphibians and identify a number of direct and indirect pathways through which UVBR may influence immune function and disease susceptibility in amphibians. By exploring the physiological mechanisms through which UVBR may affect host immune function, we demonstrate how ambient UVBR could increase amphibian susceptibility to disease. We conclude by discussing the potential implications of elevated UVBR for inter and intraspecific differences in disease dynamics and discuss how future research in this field may be directed to improve our understanding of the role that UVBR plays in amphibian immune function.
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Affiliation(s)
- Rebecca L Cramp
- School of Biological Sciences, The University of Queensland, Goddard Building (8), St Lucia, Queensland, Australia
- Corresponding author: School of Biological Sciences, The University of Queensland, Goddard Building (8), St Lucia, Queensland 4072, Australia.
| | - Craig E Franklin
- School of Biological Sciences, The University of Queensland, Goddard Building (8), St Lucia, Queensland, Australia
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9
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Elucidation of structural and functional integration of a novel antimicrobial peptide from Antheraea mylitta. Bioorg Med Chem Lett 2017; 27:1686-1692. [DOI: 10.1016/j.bmcl.2017.03.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Revised: 02/22/2017] [Accepted: 03/02/2017] [Indexed: 01/09/2023]
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Abstract
Freeze tolerance is an amazing winter survival strategy used by various amphibians and reptiles living in seasonally cold environments. These animals may spend weeks or months with up to ∼65% of their total body water frozen as extracellular ice and no physiological vital signs, and yet after thawing they return to normal life within a few hours. Two main principles of animal freeze tolerance have received much attention: the production of high concentrations of organic osmolytes (glucose, glycerol, urea among amphibians) that protect the intracellular environment, and the control of ice within the body (the first putative ice-binding protein in a frog was recently identified), but many other strategies of biochemical adaptation also contribute to freezing survival. Discussed herein are recent advances in our understanding of amphibian and reptile freeze tolerance with a focus on cell preservation strategies (chaperones, antioxidants, damage defense mechanisms), membrane transporters for water and cryoprotectants, energy metabolism, gene/protein adaptations, and the regulatory control of freeze-responsive hypometabolism at multiple levels (epigenetic regulation of DNA, microRNA action, cell signaling and transcription factor regulation, cell cycle control, and anti-apoptosis). All are providing a much more complete picture of life in the frozen state.
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Affiliation(s)
| | - Janet M. Storey
- Department of Biology, Carleton University, Ottawa, Ontario, Canada
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11
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Rollins-Smith LA. Amphibian immunity-stress, disease, and climate change. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2017; 66:111-119. [PMID: 27387153 DOI: 10.1016/j.dci.2016.07.002] [Citation(s) in RCA: 123] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 06/25/2016] [Accepted: 07/01/2016] [Indexed: 05/22/2023]
Abstract
Like all other vertebrate groups, amphibian responses to the environment are mediated through the brain (hypothalamic)-pituitary-adrenal/interrenal (HPA/I) axis and the sympathetic nervous system. Amphibians are facing historically unprecedented environmental stress due to climate change that will involve unpredictable temperature and rainfall regimes and possible nutritional deficits due to extremes of temperature and drought. At the same time, amphibians in all parts of the world are experiencing unprecedented declines due to the emerging diseases, chytridiomycosis (caused by Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans) and ranavirus diseases due to viruses of the genus Ranavirus in the family Iridoviridae. Other pathogens and parasites also afflict amphibians, but here I will limit myself to a review of recent literature linking stress and these emerging diseases (chytridiomycosis and ranavirus disease) in order to better predict how environmental stressors and disease will affect global amphibian populations.
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Affiliation(s)
- Louise A Rollins-Smith
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA; Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA; Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
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12
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Calhoun DM, Woodhams D, Howard C, LaFonte BE, Gregory JR, Johnson PTJ. Role of Antimicrobial Peptides in Amphibian Defense Against Trematode Infection. ECOHEALTH 2016; 13:383-91. [PMID: 26911920 PMCID: PMC4996749 DOI: 10.1007/s10393-016-1102-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 01/11/2016] [Accepted: 01/13/2016] [Indexed: 05/18/2023]
Abstract
Antimicrobial peptides (AMPs) contribute to the immune defenses of many vertebrates, including amphibians. As larvae, amphibians are often exposed to the infectious stages of trematode parasites, many of which must penetrate the host's skin, potentially interacting with host AMPs. We tested the effects of the natural AMPs repertoires on both the survival of trematode infectious stages as well as their ability to infect larval amphibians. All five trematode species exhibited decreased survival of cercariae in response to higher concentrations of adult bullfrog AMPs, but no effect when exposed to AMPs from larval bullfrogs. Similarly, the use of norepinephrine to remove AMPs from larval bullfrogs, Pacific chorus frogs, and gray treefrogs had only weak (gray treefrogs) or non-significant (other tested species) effects on infection success by Ribeiroia ondatrae. We nonetheless observed strong differences in parasite infection as a function of both host stage (first- versus second-year bullfrogs) and host species (Pacific chorus frogs versus gray treefrogs) that were apparently unrelated to AMPs. Taken together, our results suggest that AMPs do not play a significant role in defending larval amphibians against trematode cercariae, but that they could be one mechanism helping to prevent infection of post-metamorphic amphibians, particularly for highly aquatic species.
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Affiliation(s)
- Dana M Calhoun
- Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Ramaley N122 CB334, Boulder, CO, 80309, USA.
| | - Doug Woodhams
- Department of Biology, University of Massachusetts Boston, 100 Morrissey Blvd., Boston, MA, 02125, USA
| | - Cierra Howard
- Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Ramaley N122 CB334, Boulder, CO, 80309, USA
| | - Bryan E LaFonte
- George Washington University Law School, George Washington University, 2000 H St NW, Washington, DC, 20052, USA
| | - Jacklyn R Gregory
- Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Ramaley N122 CB334, Boulder, CO, 80309, USA
| | - Pieter T J Johnson
- Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Ramaley N122 CB334, Boulder, CO, 80309, USA
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Rebollar EA, Antwis RE, Becker MH, Belden LK, Bletz MC, Brucker RM, Harrison XA, Hughey MC, Kueneman JG, Loudon AH, McKenzie V, Medina D, Minbiole KPC, Rollins-Smith LA, Walke JB, Weiss S, Woodhams DC, Harris RN. Using "Omics" and Integrated Multi-Omics Approaches to Guide Probiotic Selection to Mitigate Chytridiomycosis and Other Emerging Infectious Diseases. Front Microbiol 2016; 7:68. [PMID: 26870025 PMCID: PMC4735675 DOI: 10.3389/fmicb.2016.00068] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 01/14/2016] [Indexed: 12/20/2022] Open
Abstract
Emerging infectious diseases in wildlife are responsible for massive population declines. In amphibians, chytridiomycosis caused by Batrachochytrium dendrobatidis, Bd, has severely affected many amphibian populations and species around the world. One promising management strategy is probiotic bioaugmentation of antifungal bacteria on amphibian skin. In vivo experimental trials using bioaugmentation strategies have had mixed results, and therefore a more informed strategy is needed to select successful probiotic candidates. Metagenomic, transcriptomic, and metabolomic methods, colloquially called "omics," are approaches that can better inform probiotic selection and optimize selection protocols. The integration of multiple omic data using bioinformatic and statistical tools and in silico models that link bacterial community structure with bacterial defensive function can allow the identification of species involved in pathogen inhibition. We recommend using 16S rRNA gene amplicon sequencing and methods such as indicator species analysis, the Kolmogorov-Smirnov Measure, and co-occurrence networks to identify bacteria that are associated with pathogen resistance in field surveys and experimental trials. In addition to 16S amplicon sequencing, we recommend approaches that give insight into symbiont function such as shotgun metagenomics, metatranscriptomics, or metabolomics to maximize the probability of finding effective probiotic candidates, which can then be isolated in culture and tested in persistence and clinical trials. An effective mitigation strategy to ameliorate chytridiomycosis and other emerging infectious diseases is necessary; the advancement of omic methods and the integration of multiple omic data provide a promising avenue toward conservation of imperiled species.
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Affiliation(s)
- Eria A. Rebollar
- Department of Biology, James Madison UniversityHarrisonburg, VA, USA
| | - Rachael E. Antwis
- Unit for Environmental Sciences and Management, North-West UniversityPotchefstroom, South Africa
- Institute of Zoology, Zoological Society of LondonLondon, UK
- School of Environment and Life Sciences, University of SalfordSalford, UK
| | - Matthew H. Becker
- Center for Conservation and Evolutionary Genetics, Smithsonian Conservation Biology Institute, National Zoological ParkWashington, DC, USA
| | - Lisa K. Belden
- Department of Biological Sciences, Virginia TechBlacksburg, VA, USA
| | - Molly C. Bletz
- Zoological Institute, Technische Universität BraunschweigBraunschweig, Germany
| | | | | | - Myra C. Hughey
- Department of Biological Sciences, Virginia TechBlacksburg, VA, USA
| | - Jordan G. Kueneman
- Department of Ecology and Evolutionary Biology, University of ColoradoBoulder, CO, USA
| | - Andrew H. Loudon
- Department of Zoology, Biodiversity Research Centre, University of British ColumbiaVancouver, BC, Canada
| | - Valerie McKenzie
- Department of Ecology and Evolutionary Biology, University of ColoradoBoulder, CO, USA
| | - Daniel Medina
- Department of Biological Sciences, Virginia TechBlacksburg, VA, USA
| | | | - Louise A. Rollins-Smith
- Department of Pathology, Microbiology and Immunology and Department of Pediatrics, Vanderbilt University School of Medicine, Department of Biological Sciences, Vanderbilt UniversityNashville, TN, USA
| | - Jenifer B. Walke
- Department of Biological Sciences, Virginia TechBlacksburg, VA, USA
| | - Sophie Weiss
- Department of Chemical and Biological Engineering, University of Colorado at BoulderBoulder, CO, USA
| | | | - Reid N. Harris
- Department of Biology, James Madison UniversityHarrisonburg, VA, USA
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Woodhams DC, Bell SC, Bigler L, Caprioli RM, Chaurand P, Lam BA, Reinert LK, Stalder U, Vazquez VM, Schliep K, Hertz A, Rollins-Smith LA. Life history linked to immune investment in developing amphibians. CONSERVATION PHYSIOLOGY 2016; 4:cow025. [PMID: 27928507 PMCID: PMC5001151 DOI: 10.1093/conphys/cow025] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 05/09/2016] [Accepted: 05/14/2016] [Indexed: 05/03/2023]
Abstract
The broad diversity of amphibian developmental strategies has been shaped, in part, by pathogen pressure, yet trade-offs between the rate of larval development and immune investment remain poorly understood. The expression of antimicrobial peptides (AMPs) in skin secretions is a crucial defense against emerging amphibian pathogens and can also indirectly affect host defense by influencing the composition of skin microbiota. We examined the constitutive or induced expression of AMPs in 17 species at multiple life-history stages. We found that AMP defenses in tadpoles of species with short larval periods (fast pace of life) were reduced in comparison with species that overwinter as tadpoles and grow to a large size. A complete set of defensive peptides emerged soon after metamorphosis. These findings support the hypothesis that species with a slow pace of life invest energy in AMP production to resist potential pathogens encountered during the long larval period, whereas species with a fast pace of life trade this investment in defense for more rapid growth and development.
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Affiliation(s)
- Douglas C Woodhams
- Department of Biology, University of Massachusetts Boston, 100 Morrissey Blvd., Boston, MA 02125, USA
- Corresponding author: Department of Biology, University of Massachusetts Boston, 100 Morrissey Blvd., Boston, MA 02125, USA. Tel: +1 617 287 6679.
| | - Sara C Bell
- College of Marine and Environmental Sciences, James Cook University, Townsville, QLD 4811, Australia
| | - Laurent Bigler
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
| | - Richard M Caprioli
- Mass Spectrometry Research Center and Department of Biochemistry, Vanderbilt University, Nashville, TN 37232-8575, USA
| | - Pierre Chaurand
- Department of Chemistry, Université de Montréal, Montreal, QC, Canada H3T 1J4
| | - Brianna A Lam
- Department of Biology, James Madison University, MSC 7801, Harrisonburg, VA 22807, USA
| | - Laura K Reinert
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232-2363, USA
| | - Urs Stalder
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
| | | | - Klaus Schliep
- Department of Biology, University of Massachusetts Boston, 100 Morrissey Blvd., Boston, MA 02125, USA
| | - Andreas Hertz
- Department of Biology, University of Massachusetts Boston, 100 Morrissey Blvd., Boston, MA 02125, USA
| | - Louise A Rollins-Smith
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232-2363, USA
- Department of Biological Science, Vanderbilt University, Nashville, TN 37235-1634, USA
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN 37232-2363, USA
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Free-radical first responders: the characterization of CuZnSOD and MnSOD regulation during freezing of the freeze-tolerant North American wood frog, Rana sylvatica. Biochim Biophys Acta Gen Subj 2014; 1850:97-106. [PMID: 25316288 DOI: 10.1016/j.bbagen.2014.10.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 10/03/2014] [Accepted: 10/06/2014] [Indexed: 11/21/2022]
Abstract
BACKGROUND The North American wood frog, Rana sylvatica, is able to overcome subzero conditions through overwintering in a frozen state. Freezing imposes ischemic and oxidative stress on cells as a result of cessation of blood flow. Superoxide dismutases (SODs) catalyze the redox reaction involving the dismutation of superoxide (O(2)(-)) to molecular oxygen and hydrogen peroxide. METHODS The present study investigated the regulation of CuZnSOD and MnSOD kinetics as well as the transcript, protein and phosphorylation levels of purified enzyme from the muscle of control and frozen R. sylvatica. RESULTS CuZnSOD from frozen muscle showed a significantly higher V(max) (1.52 fold) in comparison to CuZnSOD from the muscle of control frogs. MnSOD from frozen muscle showed a significantly lower Km for O(2)(-) (0.66 fold) in comparison to CuZnSOD from control frogs. MnSOD from frozen frogs showed higher phosphorylation of serine (2.36 fold) and tyrosine (1.27 fold) residues in comparison to MnSOD from control animals. Susceptibility to digestion via thermolysin after incubation with increasing amount of urea (C(m)) was tested, resulting in no significant changes for CuZnSOD, whereas a significant change in MnSOD stability was observed between control (2.53 M urea) and frozen (2.92 M urea) frogs. Expressions of CuZnSOD and MnSOD were quantified at both mRNA and protein levels in frog muscle, but were not significantly different. CONCLUSION The physiological consequence of freeze-induced SOD modification appears to adjust SOD function in freezing frogs. GENERAL SIGNIFICANCE Augmented SOD activity may increase the ability of R. sylvatica to overcome oxidative stress associated with ischemia.
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