ORCID Profile
0000-0001-9423-557X
Current Organisation
University of Tasmania
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Zoology | Animal Cell and Molecular Biology | Animal Developmental and Reproductive Biology |
Publisher: Springer Science and Business Media LLC
Date: 28-03-2018
DOI: 10.1038/S41467-018-03638-6
Abstract: Colony-stimulating factor 1 (CSF1) controls the growth and differentiation of macrophages.CSF1R signaling has been implicated in the maintenance of the intestinal stem cell niche and differentiation of Paneth cells, but evidence of expression of CSF1R within the crypt is equivocal. Here we show that CSF1R-dependent macrophages influence intestinal epithelial differentiation and homeostasis. In the intestinal lamina propria CSF1R mRNA expression is restricted to macrophages which are intimately associated with the crypt epithelium, and is undetectable in Paneth cells. Macrophage ablation following CSF1R blockade affects Paneth cell differentiation and leads to a reduction of Lgr5 + intestinal stem cells. The disturbances to the crypt caused by macrophage depletion adversely affect the subsequent differentiation of intestinal epithelial cell lineages. Goblet cell density is enhanced, whereas the development of M cells in Peyer’s patches is impeded. We suggest that modification of the phenotype or abundance of macrophages in the gut wall alters the development of the intestinal epithelium and the ability to s le gut antigens.
Publisher: Elsevier BV
Date: 06-2022
Publisher: Elsevier BV
Date: 09-2021
Publisher: Springer Science and Business Media LLC
Date: 02-03-2021
Publisher: Public Library of Science (PLoS)
Date: 03-06-2021
DOI: 10.1371/JOURNAL.PGEN.1009605
Abstract: Homozygous mutation of the Csf1r locus ( Csf1rko ) in mice, rats and humans leads to multiple postnatal developmental abnormalities. To enable analysis of the mechanisms underlying the phenotypic impacts of Csf1r mutation, we bred a rat Csf1rko allele to the inbred dark agouti (DA) genetic background and to a Csf1r -mApple reporter transgene. The Csf1rko led to almost complete loss of embryonic macrophages and ablation of most adult tissue macrophage populations. We extended previous analysis of the Csf1rko phenotype to early postnatal development to reveal impacts on musculoskeletal development and proliferation and morphogenesis in multiple organs. Expression profiling of 3-week old wild-type (WT) and Csf1rko livers identified 2760 differentially expressed genes associated with the loss of macrophages, severe hypoplasia, delayed hepatocyte maturation, disrupted lipid metabolism and the IGF1/IGF binding protein system. Older Csf1rko rats developed severe hepatic steatosis. Consistent with the developmental delay in the liver Csf1rko rats had greatly-reduced circulating IGF1. Transfer of WT bone marrow (BM) cells at weaning without conditioning repopulated resident macrophages in all organs, including microglia in the brain, and reversed the mutant phenotypes enabling long term survival and fertility. WT BM transfer restored osteoclasts, eliminated osteopetrosis, restored bone marrow cellularity and architecture and reversed granulocytosis and B cell deficiency. Csf1rko rats had an elevated circulating CSF1 concentration which was rapidly reduced to WT levels following BM transfer. However, CD43 hi non-classical monocytes, absent in the Csf1rko , were not rescued and bone marrow progenitors remained unresponsive to CSF1. The results demonstrate that the Csf1rko phenotype is autonomous to BM-derived cells and indicate that BM contains a progenitor of tissue macrophages distinct from hematopoietic stem cells. The model provides a unique system in which to define the pathways of development of resident tissue macrophages and their local and systemic roles in growth and organ maturation.
Publisher: The American Association of Immunologists
Date: 15-05-2021
Abstract: The laboratory rat continues to be the model of choice for many studies of physiology, behavior, and complex human diseases. Cells of the mononuclear phagocyte system (MPS monocytes, macrophages, and dendritic cells) are abundant residents in every tissue in the body and regulate postnatal development, homeostasis, and innate and acquired immunity. Recruitment and proliferation of MPS cells is an essential component of both initiation and resolution of inflammation. The large majority of current knowledge of MPS biology is derived from studies of inbred mice, but advances in technology and resources have eliminated many of the advantages of the mouse as a model. In this article, we review the tools available and the current state of knowledge of development, homeostasis, regulation, and ersity within the MPS of the rat.
Publisher: Elsevier BV
Date: 2021
Publisher: Elsevier BV
Date: 12-2020
Publisher: The Company of Biologists
Date: 12-2020
DOI: 10.1242/DEV.194449
Abstract: The central nervous system hosts parenchymal macrophages, known as microglia, and non-parenchymal macrophages, collectively termed border-associated macrophages (BAMs). Microglia, but not BAMs, were reported to be absent in mice lacking a conserved Csf1r enhancer: the fms-intronic regulatory element (FIRE). However, it is unknown whether FIRE deficiency also impacts BAM arrival and/or maintenance. Here, we show that macrophages in the ventricular system of the brain, including Kolmer's epiplexus macrophages, are absent in Csf1rΔFIRE/ΔFIRE mice. Stromal choroid plexus BAMs are also considerably reduced. During normal development, we demonstrate that intracerebroventricular macrophages arrive from embryonic day 10.5, and can traverse ventricular walls in embryonic slice cultures. In Csf1rΔFIRE/ΔFIRE embryos, the arrival of both primitive microglia and intracerebroventricular macrophages was eliminated, whereas the arrival of cephalic mesenchyme and stromal choroid plexus BAMs was only partially restricted. Our results provide new insights into the development and regulation of different CNS macrophage populations.
Publisher: Springer Science and Business Media LLC
Date: 29-05-2022
Publisher: The American Association of Immunologists
Date: 2018
DOI: 10.4049/IMMUNOHORIZONS.1700073
Abstract: Activated mouse macrophages metabolize arginine via NO synthase (NOS2) to produce NO as an antimicrobial effector. Published gene expression datasets provide little support for the activation of this pathway in human macrophages. Generation of NO requires the coordinated regulation of multiple genes. We have generated RNA-sequencing data from bone marrow–derived macrophages from representative rodent (rat), monogastric (pig and horse), and ruminant (sheep, goat, cattle, and water buffalo) species, and analyzed the expression of genes involved in arginine metabolism in response to stimulation with LPS. In rats, as in mice, LPS strongly induced Nos2, the arginine transporter Slc7a2, arginase 1 (Arg1), GTP cyclohydrolase (Gch1), and argininosuccinate synthase (Ass1). None of these responses was conserved across species. Only cattle and water buffalo showed substantial NOS2 induction. The species studied also differed in expression and regulation of arginase (ARG2, rather than ARG1), and amino acid transporters. Variation between species was associated with rapid promoter evolution. Differential induction of NOS2 and ARG2 between the ruminant species was associated with insertions of the Bov-A2 retrotransposon in the promoter region. Bov-A2 was shown to possess LPS-inducible enhancer activity in transfected RAW264.7 macrophages. Consistent with a function in innate immunity, NO production and arginine metabolism vary greatly between species and differences may contribute to pathogen host restriction.
Publisher: Springer Science and Business Media LLC
Date: 19-07-2019
DOI: 10.1038/S41467-019-11053-8
Abstract: The proliferation, differentiation and survival of mononuclear phagocytes depend on signals from the receptor for macrophage colony-stimulating factor, CSF1R. The mammalian Csf1r locus contains a highly conserved super-enhancer, the fms -intronic regulatory element (FIRE). Here we show that genomic deletion of FIRE in mice selectively impacts CSF1R expression and tissue macrophage development in specific tissues. Deletion of FIRE ablates macrophage development from murine embryonic stem cells. Csf1r ΔFIRE/ΔFIRE mice lack macrophages in the embryo, brain microglia and resident macrophages in the skin, kidney, heart and peritoneum. The homeostasis of other macrophage populations and monocytes is unaffected, but monocytes and their progenitors in bone marrow lack surface CSF1R. Finally, Csf1r ΔFIRE/ΔFIRE mice are healthy and fertile without the growth, neurological or developmental abnormalities reported in Csf1r −/− rodents. Csf1r ΔFIRE/ΔFIRE mice thus provide a model to explore the homeostatic, physiological and immunological functions of tissue-specific macrophage populations in adult animals.
Publisher: The American Association of Immunologists
Date: 15-09-2016
Abstract: Expression of Csf1r in adults is restricted to cells of the macrophage lineage. Transgenic reporters based upon the Csf1r locus require inclusion of the highly conserved Fms-intronic regulatory element for expression. We have created Csf1r-EGFP transgenic sheep via lentiviral transgenesis of a construct containing elements of the mouse Fms-intronic regulatory element and Csf1r promoter. Committed bone marrow macrophage precursors and blood monocytes express EGFP in these animals. Sheep monocytes were ided into three populations, similar to classical, intermediate, and nonclassical monocytes in humans, based upon CD14 and CD16 expression. All expressed EGFP, with increased levels in the nonclassical subset. Because Csf1r expression coincides with the earliest commitment to the macrophage lineage, Csf1r-EGFP bone marrow provides a tool for studying the earliest events in myelopoiesis using the sheep as a model.
Publisher: Elsevier BV
Date: 10-2012
DOI: 10.1016/J.FOODCHEM.2012.04.004
Abstract: Sesamin, a major sesame seed lignan, has erse biological functions including the modulation of molecular actions in lipid metabolic pathways and reducing cholesterol levels. Vertebrates have different capacities to biosynthesize long-chain PUFA from dietary precursors and sesamin can enhance the biosynthesis of ALA to EPA and DHA in marine teleost. Early juvenile barramundi, Lates calcarifer, were fed for two weeks on diets rich in ALA or SDA derived from linseed or Echium plantagineum, respectively. Both diets contained phytosterols and less cholesterol compared with a standard fish oil-based diet. The growth rates were reduced in the animals receiving sesamin regardless of the dietary oil. However, the relative levels of n-3 LC-PUFA in total lipid, but not the phospholipid, increased in the whole body by up to 25% in animals fed on sesamin with ALA or SDA. Sesamin reduced the relative levels of triacylglycerols and increased polar lipid, and did not affect the relative composition of phospholipid subclasses or sterols. Sesamin is a potent modulator for LC-PUFA biosynthesis in animals, but probably will have more effective impact at advanced ages. By modulating certain lipid metabolic pathways, sesamin has probably disrupted the body growth and development of organs and tissues in early juvenile barramundi.
Publisher: American Physiological Society
Date: 03-2018
Abstract: Signaling via the colony-stimulating factor 1 receptor (CSF1R) controls the survival, differentiation, and proliferation of macrophages. Mutations in CSF1 or CSF1R in mice and rats have pleiotropic effects on postnatal somatic growth. We tested the possible application of pig CSF1-Fc fusion protein as a therapy for low birth weight (LBW) at term, using a model based on maternal dexamethasone treatment in rats. Neonatal CSF1-Fc treatment did not alter somatic growth and did not increase the blood monocyte count. Instead, there was a substantial increase in the size of liver in both control and LBW rats, and the treatment greatly exacerbated lipid droplet accumulation seen in the dexamethasone LBW model. These effects were reversed upon cessation of treatment. Transcriptional profiling of the livers supported histochemical evidence of a large increase in macrophages with a resident Kupffer cell phenotype and revealed increased expression of many genes implicated in lipid droplet formation. There was no further increase in hepatocyte proliferation over the already high rates in neonatal liver. In conclusion, treatment of neonatal rats with CSF1-Fc caused an increase in liver size and hepatic lipid accumulation, due to Kupffer cell expansion and/or activation rather than hepatocyte proliferation. Increased liver macrophage numbers and expression of endocytic receptors could mitigate defective clearance functions in neonates. NEW & NOTEWORTHY This study is based on extensive studies in mice and pigs of the role of CSF1/CSF1R in macrophage development and postnatal growth. We extended the study to neonatal rats as a possible therapy for low birth weight. Unlike our previous studies in mice and pigs, there was no increase in hepatocyte proliferation and no increase in monocyte numbers. Instead, neonatal rats treated with CSF1 displayed reversible hepatic steatosis and Kupffer cell expansion.
Publisher: CRC Press
Date: 19-07-2011
Publisher: Elsevier BV
Date: 06-2022
DOI: 10.1016/J.CBD.2022.100994
Abstract: Understanding the molecular mechanisms that underlie differences in feed efficiency (FE) is an important step toward optimising growth and achieving sustainable salmonid aquaculture. In this study, the liver and white muscle proteomes of feed efficient (EFF) and inefficient (INEFF) Chinook salmon (Oncorhynchus tshawytscha) reared in seawater were investigated by liquid chromatography-tandem mass spectrometry (LC-MS/MS). In total, 2746 liver and 702 white muscle proteins were quantified and compared between 21 EFF and 22 INEFF fish. GSEA showed that gene sets related to protein synthesis were enriched in the liver and white muscle of the EFF group, while conversely, pathways related to protein degradation (amino acid catabolism and proteolysis, respectively) were the most affected processes in the liver and white muscle of INEFF fish. Estimates of in idual daily feed intake and share of the meal within tank were significantly higher in the INEFF than the EFF fish showing INEFF fish were likely more dominant during feeding and overfed. Overeating by the INEFF fish was associated with an increase in protein catabolism. This study found that fish with different FE values had expression differences in the gene sets related to protein turnover, and this result supports the hypothesis that protein metabolism plays a role in FE.
Publisher: Elsevier BV
Date: 11-2022
Publisher: Elsevier BV
Date: 07-2020
Publisher: Cold Spring Harbor Laboratory
Date: 05-2017
DOI: 10.1101/132696
Abstract: Sheep are a key source of meat, milk and fibre for the global livestock sector, and an important biomedical model. Global analysis of gene expression across multiple tissues has aided genome annotation and supported functional annotation of mammalian genes. We present a large-scale RNA-Seq dataset representing all the major organ systems from adult sheep and from several juvenile, neonatal and prenatal developmental time points. The Ovis aries reference genome (Oar v3.1) includes 27,504 genes (20,921 protein coding), of which 25,350 (19,921 protein coding) had detectable expression in at least one tissue in the sheep gene expression atlas dataset. Network-based cluster analysis of this dataset grouped genes according to their expression pattern. The principle of ‘guilt by association’ was used to infer the function of uncharacterised genes from their co-expression with genes of known function. We describe the overall transcriptional signatures present in the sheep gene expression atlas and assign those signatures, where possible, to specific cell populations or pathways. The findings are related to innate immunity by focusing on clusters with an immune signature, and to the advantages of cross-breeding by examining the patterns of genes exhibiting the greatest expression differences between purebred and crossbred animals. This high-resolution gene expression atlas for sheep is, to our knowledge, the largest transcriptomic dataset from any livestock species to date. It provides a resource to improve the annotation of the current reference genome for sheep, presenting a model transcriptome for ruminants and insight into gene, cell and tissue function at multiple developmental stages. Sheep are ruminant mammals kept as livestock for the production of meat, milk and wool in agricultural industries across the globe. Genetic and genomic information can be used to improve production traits such as disease resiliance. The sheep genome is however missing important information relating to gene function and many genes, which may be important for productivity, have no informative gene name. This can be remedied using RNA-Sequencing to generate a global expression profile of all protein-coding genes, across multiple organ systems and developmental stages. Clustering genes based on their expression profile across tissues and cells allows us to assign function to those genes. If for ex le a gene with no informative gene name is expressed in macrophages and is found within a cluster of known macrophage related genes it is likely to be involved in macrophage function and play a role in innate immunity. This information improves the quality of the reference genome and provides insight into biological processes underlying the complex traits that influence the productivity of sheep and other livestock species.
Publisher: Cold Spring Harbor Laboratory
Date: 09-07-2020
DOI: 10.1101/2020.07.09.196402
Abstract: The proliferation, differentiation and survival of cells of the mononuclear phagocyte system (MPS, progenitors, monocytes, macrophages and classical dendritic cells) is controlled by signals from the macrophage colony-stimulating factor receptor (CSF1R). Cells of the MPS lineage have been identified using numerous surface markers and transgenic reporters but none is both universal and lineage-restricted. Here we report the development and characterization of a novel CSF1R reporter mouse. A Fusion Red (FRed) cassette was inserted in-frame with the C-terminus of CSF1R, separated by a T2A-cleavable linker. The insertion had no effect of CSF1R expression or function. CSF1R-FRed was expressed in monocytes and macrophages and absent from granulocytes and lymphocytes. In bone marrow, CSF1R-FRed was absent in lineage-negative hematopoietic stem cells (HSC), arguing against a direct role for CSF1R in myeloid lineage commitment. It was highly-expressed in marrow monocytes and common myeloid progenitors (CMP) but significantly lower in granulocyte-macrophage progenitors (GMP). In sections of bone marrow, CSF1R-FRed was also detected in osteoclasts, CD169 + resident macrophages and, consistent with previous mRNA analysis, in megakaryocytes. In lymphoid tissues, CSF1R-FRed highlighted erse MPS populations including classical dendritic cells. Whole mount imaging of non-lymphoid tissues in mice with combined CSF1R-FRed/ Csf1r -EGFP confirmed the restriction of CSF1R expression to MPS cells. The two markers highlight the remarkable abundance and regular distribution of tissue MPS cells including novel macrophage populations within tendon and skeletal muscle and underlying the mesothelial/serosal/capsular surfaces of every major organ. The CSF1R-FRed mouse provides a novel reporter with exquisite specificity for cells of the MPS.
Publisher: The American Association of Immunologists
Date: 12-2020
Abstract: The proliferation, differentiation, and survival of cells of the mononuclear phagocyte system (MPS progenitors, monocytes, macrophages, and classical dendritic cells) are controlled by signals from the M-CSF receptor (CSF1R). Cells of the MPS lineage have been identified using numerous surface markers and transgenic reporters, but none is both universal and lineage restricted. In this article, we report the development and characterization of a CSF1R reporter mouse. A FusionRed (FRed) cassette was inserted in-frame with the C terminus of CSF1R, separated by a T2A-cleavable linker. The insertion had no effect of CSF1R expression or function. CSF1R-FRed was expressed in monocytes and macrophages and absent from granulocytes and lymphocytes. In bone marrow, CSF1R-FRed was absent in lineage-negative hematopoietic stem cells, arguing against a direct role for CSF1R in myeloid lineage commitment. It was highly expressed in marrow monocytes and common myeloid progenitors but significantly lower in granulocyte-macrophage progenitors. In sections of bone marrow, CSF1R-FRed was also detected in osteoclasts, CD169+ resident macrophages, and, consistent with previous mRNA analysis, in megakaryocytes. In lymphoid tissues, CSF1R-FRed highlighted erse MPS populations, including classical dendritic cells. Whole mount imaging of nonlymphoid tissues in mice with combined CSF1R-FRed/Csf1r-EGFP confirmed the restriction of CSF1R expression to MPS cells. The two markers highlight the remarkable abundance and regular distribution of tissue MPS cells, including novel macrophage populations within tendon and skeletal muscle and underlying the mesothelial/serosal/capsular surfaces of every major organ. The CSF1R-FRed mouse provides a novel reporter with exquisite specificity for cells of the MPS.
Publisher: Wiley
Date: 26-12-2020
DOI: 10.1111/RAQ.12522
Abstract: The respiratory quotient (RQ) has been used extensively as an index to evaluate metabolic energy expenditure in terrestrial animals including humans. In contrast, RQ use in understanding physiology and nutrition of aquatic ectotherms has been restricted due to technical challenges in measuring total CO 2 in water. With technical advances in measuring total CO 2 in water, RQ in aquatic ectotherms can be accurately determined and is potentially available as a valuable method. Here, we provide a comprehensive review of studies on RQ and metabolic energy substrate use in aquatic ectotherms. Metabolic energy substrate use is evaluated by a reliable stoichiometric bioenergetic approach, based on measuring RQ and nitrogen quotient (NQ) simultaneously. Stoichiometry provides a non‐destructive and unequivocal way to quantify the instantaneous oxidation of each major energy substrate (protein, lipid or carbohydrate). This review aims to refine knowledge about bioenergetics of aquatic ectotherms under different conditions including nutritional aspects of sustainable aquaculture. Notably, stoichiometry provides a promising approach to optimize feeds and feeding regimes to realize sustainable aquaculture under differing conditions and with differing feed ingredients. It also provides an approach to consider climate change impacts and physiological adaptation mechanisms for survival and development in farmed environments and natural ecosystems. Stoichiometric bioenergetics knowledge in aquatic ectotherms has relevance to commercial impacts in the face of overfishing and food security, and ecological significance in the face of environmental change scenarios. We suggest expanding the use of stoichiometry in future bioenergetic research in emerging aquaculture species.
Publisher: MDPI AG
Date: 15-08-2023
Abstract: Fish aquaculture is a rapidly expanding global industry, set to support growing demands for sources of marine protein. Enhancing feed efficiency (FE) in farmed fish is required to reduce production costs and improve sector sustainability. Recognising that organisms are complex systems whose emerging phenotypes are the product of multiple interacting molecular processes, systems-based approaches are expected to deliver new biological insights into FE and growth performance. Here, we establish 14 erse layers of multi-omics and clinical covariates to assess their capacities to predict FE and associated performance traits in a fish model (Oncorhynchus tshawytscha) and uncover the influential variables. Inter-omic relatedness between the different layers revealed several significant concordances, particularly between datasets originating from similar material/tissue and between blood indicators and some of the proteomic (liver), metabolomic (liver), and microbiomic layers. Single- and multi-layer random forest (RF) regression models showed that integration of all data layers provide greater FE prediction power than any single-layer model alone. Although FE was among the most challenging of the traits we attempted to predict, the mean accuracy of 40 different FE models in terms of root-mean square errors normalized to percentage was 30.4%, supporting RF as a feature selection tool and approach for complex trait prediction. Major contributions to the integrated FE models were derived from layers of proteomic and metabolomic data, with substantial influence also provided by the lipid composition layer. A correlation matrix of the top 27 variables in the models highlighted FE trait-associations with faecal bacteria (Serratia spp.), palmitic and nervonic acid moieties in whole body lipids, levels of free glycerol in muscle, and N-acetylglutamic acid content in liver. In summary, we identified subsets of molecular characteristics for the assessment of commercially relevant performance-based metrics in farmed Chinook salmon.
Publisher: Springer Science and Business Media LLC
Date: 17-05-2019
DOI: 10.1007/S00360-019-01221-Z
Abstract: Metabolism in aquatic ectotherms evaluated by oxygen consumption rates reflects energetic costs including those associated with protein synthesis. Metabolism is influenced by nutritional status governed by feeding, nutrient intake and quality, and time without food. However, little is understood about contribution of protein synthesis to crustacean energy metabolism. This study is the first using a protein synthesis inhibitor cycloheximide to research contribution of cycloheximide-sensitive protein synthesis to decapod crustacean metabolism. Juvenile Sagmariasus verreauxi were subject to five treatments: 2-day fasted lobsters sham injected with saline 2-day fasted lobsters injected with cycloheximide 10-day starved lobsters injected with cycloheximide post-prandial lobsters fed with squid Nototodarus sloanii with no further treatment and post-prandial lobsters injected with cycloheximide. Standard and routine metabolic rates in starved lobsters were reduced by 32% and 41%, respectively, compared to fasted lobsters, demonstrating metabolic downregulation with starvation. Oxygen consumption rates of fasted and starved lobsters following cycloheximide injection were reduced by 29% and 13%, respectively, demonstrating protein synthesis represents only a minor component of energy metabolism in unfed lobsters. Oxygen consumption rate of fed lobsters was reduced by 96% following cycloheximide injection, demonstrating protein synthesis in decapods contributes a major proportion of specific dynamic action (SDA). SDA in decapods is predominantly a post-absorptive process likely related to somatic growth. This work extends previously limited knowledge on contribution of protein synthesis to crustacean metabolism, which is crucial to explore the relationship between nutritional status and diet quality and how this will affect growth potential in aquaculture species.
Publisher: Wiley
Date: 26-08-2019
DOI: 10.1111/RAQ.12287
Publisher: Elsevier BV
Date: 2023
Publisher: Cold Spring Harbor Laboratory
Date: 06-04-2018
DOI: 10.1101/296749
Abstract: Several different transgenic tamoxifen-inducible cre reporter lines have been used to analyse the contribution of embryonic precursors to the development of the mononuclear phagocyte system in mice. Here we show that tamoxifen treatment of the mother at 8.5dpc with doses commonly-used in lineage trace studies produces a 4-5-fold expansion of the embryonic leukocyte populations by 10.5dpc, detected in whole mounts of embryos using a Csf1r reporter gene or separately by expression of Csf1r, Itgam (CD11b), Adgre1 (F4/80) or Ptprc (CD45) mRNA. These findings indicate that tamoxifen cannot be considered a neutral agonist in macrophage lineage trace studies. Treatment of pregnant mice with tamoxifen in early gestation produces a large expansion of the embryonic macrophage population.
Publisher: Elsevier BV
Date: 09-2021
Publisher: Elsevier BV
Date: 11-2013
DOI: 10.1016/J.FOODCHEM.2013.04.052
Abstract: Pathogen infection stimulates the fatty acid (FA) metabolism and the production of pro-inflammatory derivatives of FA. Barramundi, Lates calcarifer, was fed on a diet rich in preformed long-chain (⩾C20) polyunsaturated fatty acids (LC-PUFA) from fish oil (FO), to compare with diets containing high levels of C18 precursors for LC-PUFA - stearidonic (SDA) and γ-linolenic acid (GLA) - from Echium plantagineum (EO), or rapeseed oil (RO) rich in α-linolenic acid (ALA), but a poor source of LC-PUFA and their precursors. After 6weeks, when growth rates were similar amongst the dietary treatments, a sub-lethal dose of Streptococcus iniae was administered to half of the fish, while the other half were maintained unchallenged and were pair-fed with the infected fish. Under a disease challenge situation, the tissue FA depots depleted at 3days post-infection (DPI) and were then restored to their previous concentrations at 7DPI. During the infection period, EO fish had a higher content of n3 and n6 PUFA in their tissues, higher n3:n6 PUFA ratio and reduced levels of the eicosanoids, TXB2 and 6-keto-PGF1α, in their plasma compared with RO fish. Fish fed on FO and EO had a longer lasting and enduring response in their FA and eicosanoid concentrations, following a week of bacterial infection, compared with those fed on RO. EO, containing SDA and GLA and with a comparatively higher n3:n6 PUFA ratio, proved more effective than RO in compensating for immunity stress.
Publisher: Elsevier BV
Date: 06-2013
DOI: 10.1016/J.CBPA.2013.03.019
Abstract: Metabolic responses to sub-optimal temperature deplete lipid depots, remodel membrane lipid and alter the fatty acid profile in the whole body and tissues of ectothermic vertebrates including fish. The magnitude of these changes may depend on dietary history including oil sources with different fatty acid compositions. Barramundi, Lates calcarifer (Perciformes, Latidae), a tropical ectothermic fish, was fed on diets either rich in dietary long-chain (≥C(20)) polyunsaturated fatty acids (LC-PUFA) from fish oil, rich in stearidonic and γ-linolenic acid (SDA and GLA, respectively) from Echium plantagineum, or rapeseed oil deficient in LC-PUFA. Following 5 weeks at the optimum temperature of 30 °C when growth rates were comparable amongst dietary treatments, water temperature was dropped to 20 °C for 1 week for half of the animals and maintained at 30 °C for the other half. Decreased temperature increased the liver and skeletal muscle content of LC-PUFA in fish fed on echium oil compared with rapeseed oil, while dietary LC-PUFA depots in fish oil fed-fish depleted rapidly in the week of sub-optimal temperature. The lipid unsaturation index of cellular membrane in the liver and muscle increased under low temperature at the same rate regardless of dietary oil. Therefore, rapid exposure of an ectothermic vertebrate to a lower and sub-optimal temperature caused significant modulation in fatty acid composition. We propose that the tolerance of barramundi, a representative of tropical farmed fish, to sub-optimal temperature will be enhanced when fatty acid substrates closer to the LC-PUFA are available in their diet.
Publisher: Elsevier BV
Date: 03-2022
Publisher: American Chemical Society (ACS)
Date: 08-07-2011
DOI: 10.1021/JF201871W
Abstract: The limited activity of Δ6 fatty acid desaturase (FAD6) on α-linolenic (ALA, 18:3n-3) and linoleic (LA, 18:2n-6) acids in marine fish alters the long-chain (≥C(20)) polyunsaturated fatty acid (LC-PUFA) concentration in fish muscle and liver when vegetable oils replace fish oil (FO) in aquafeeds. Echium oil (EO), rich in stearidonic acid (SDA, 18:4n-3) and γ-linoleic acid (GLA, 18:3n-6), may enhance the biosynthesis of n-3 and n-6 LC-PUFA by bypassing the rate-limiting FAD6 step. Nutritional and environmental modulation of the mechanisms in LC-PUFA biosynthesis was examined in barramundi, Lates calcarifer , a tropical euryhaline fish. Juveniles were maintained in either freshwater or seawater and fed different dietary LC-PUFA precursors present in EO or rapeseed oil (RO) and compared with FO. After 8 weeks, growth of fish fed EO was slower compared to the FO and RO treatments. Irrespective of salinity, expression of the FAD6 and elongase was up-regulated in fish fed EO and RO diets, but did not lead to significant accumulation of LC-PUFA in the neutral lipid of fish tissues as occurred in the FO treatment. However, significant concentrations of eicosapentaenoic acid (EPA, 20:5n-3) and arachidonic acid (ARA, 20:4n-6), but not docosahexaenoic acid (DHA, 22:6n-3), appeared in liver and, to a lesser extent, in muscle of fish fed EO with marked increases in the phospholipid fraction. Fish in the EO treatment had higher EPA and ARA in their liver phospholipids than fish fed FO. Endogenous conversion of dietary precursors into neutral lipid LC-PUFA appears to be limited by factors other than the initial rate-limiting step. In contrast, phospholipid LC-PUFA had higher biosynthesis, or selective retention, in barramundi fed EO rather than RO.
Publisher: Hindawi Limited
Date: 31-03-2021
DOI: 10.1111/ARE.15219
Publisher: Public Library of Science (PLoS)
Date: 15-12-2016
Publisher: Elsevier BV
Date: 08-1620
Publisher: Springer Science and Business Media LLC
Date: 03-06-2021
DOI: 10.1038/S41598-021-91304-1
Abstract: This is the first study in an aquatic ectotherm to combine a stoichiometric bioenergetic approach with an endpoint stochastic model to explore dietary macronutrient content. The combination of measuring respiratory gas (O 2 and CO 2 ) exchange, nitrogenous (ammonia and urea) excretion, specific dynamic action (SDA), metabolic energy substrate use, and whole-body protein synthesis in spiny lobster, Sagmariasus verreauxi , was examined in relation to dietary protein. Three isoenergetic feeds were formulated with varying crude protein: 40%, 50% and 60%, corresponding to CP 40 , CP 50 and CP 60 treatments, respectively. Total CO 2 and ammonia excretion, SDA magnitude and coefficient, and protein synthesis in the CP 60 treatment were higher compared to the CP 40 treatment. These differences demonstrate dietary protein influences post-prandial energy metabolism. Metabolic use of each major energy substrate varied at different post-prandial times, indicating suitable amounts of high-quality protein with major non-protein energy-yielding nutrients, lipid and carbohydrate, are critical for lobsters. The average contribution of protein oxidation was lowest in the CP 50 treatment, suggesting mechanisms underlying the most efficient retention of dietary protein and suitable dietary inclusion. This study advances understanding of how deficient and surplus dietary protein affects energy metabolism and provides approaches for fine-scale feed evaluation to support sustainable aquaculture.
Publisher: Elsevier BV
Date: 02-2011
Publisher: Elsevier BV
Date: 2019
Publisher: Elsevier BV
Date: 03-2022
DOI: 10.1016/J.CBPA.2021.111121
Abstract: Apparent digestibility and gastrointestinal evacuation rate were measured to assess the potential of five commercially available protein sources for their inclusion in feeds for juvenile slipper lobster, Thenus australiensis. Protein sources tested were fishmeal, krill meal, lupin meal, soybean meal and squid by-product meal. Apparent digestibility of crude protein ranged from 79.6% to 95.3%, with fishmeal protein significantly less digestible than lupin meal, squid by-product meal and soybean meal. Gastrointestinal evacuation rate was estimated from marker replacement, where yttrium oxide replaced ytterbium oxide. Faeces were collected every 3 h for 48 h, and a kinetic model was used to calculate the rate and time for the second marker to replace the first marker. Gastrointestinal evacuation (≥ 95%) was completed between 4 and 6 h with no significant differences among protein sources. Faeces consisted of both markers in equal parts 2.7 to 5.0 h after the feed switch, with lupin meal reaching the midpoint significantly faster than squid by-product meal and reference feed. The present study is the first in crustaceans to examine the relationship between apparent digestibility and gastrointestinal evacuation, showing more digestible protein sources had slower evacuation rates. The combined approach provides deeper insight into crustaceans' digestive physiology and helps understand their ability to digest specific ingredients. Further research is recommended to understand protein requirements in a broader context to verify highly digestible protein sources meet all nutritional requirements.
Publisher: Elsevier BV
Date: 02-2021
Publisher: The American Association of Immunologists
Date: 15-03-2018
Abstract: CSF1 is the primary growth factor controlling macrophage numbers, but whether expression of the CSF1 receptor differs between discrete populations of mononuclear phagocytes remains unclear. We have generated a Csf1r-mApple transgenic fluorescent reporter mouse that, in combination with lineage tracing, Alexa Fluor 647–labeled CSF1-Fc and CSF1, and a modified ΔCsf1–enhanced cyan fluorescent protein (ECFP) transgene that lacks a 150 bp segment of the distal promoter, we have used to dissect the differentiation and CSF1 responsiveness of mononuclear phagocyte populations in situ. Consistent with previous Csf1r-driven reporter lines, Csf1r-mApple was expressed in blood monocytes and at higher levels in tissue macrophages, and was readily detectable in whole mounts or with multiphoton microscopy. In the liver and peritoneal cavity, uptake of labeled CSF1 largely reflected transgene expression, with greater receptor activity in mature macrophages than monocytes and tissue-specific expression in conventional dendritic cells. However, CSF1 uptake also differed between subsets of monocytes and discrete populations of tissue macrophages, which in macrophages correlated with their level of dependence on CSF1 receptor signaling for survival rather than degree of transgene expression. A double ΔCsf1r-ECFP-Csf1r-mApple transgenic mouse distinguished subpopulations of microglia in the brain, and permitted imaging of interstitial macrophages distinct from alveolar macrophages, and pulmonary monocytes and conventional dendritic cells. The Csf1r-mApple mice and fluorescently labeled CSF1 will be valuable resources for the study of macrophage and CSF1 biology, which are compatible with existing EGFP-based reporter lines.
Publisher: The American Association of Immunologists
Date: 11-2018
Abstract: We have produced Csf1r-deficient rats by homologous recombination in embryonic stem cells. Consistent with the role of Csf1r in macrophage differentiation, there was a loss of peripheral blood monocytes, microglia in the brain, epidermal Langerhans cells, splenic marginal zone macrophages, bone-associated macrophages and osteoclasts, and peritoneal macrophages. Macrophages of splenic red pulp, liver, lung, and gut were less affected. The pleiotropic impacts of the loss of macrophages on development of multiple organ systems in rats were distinct from those reported in mice. Csf1r−/− rats survived well into adulthood with postnatal growth retardation, distinct skeletal and bone marrow abnormalities, infertility, and loss of visceral adipose tissue. Gene expression analysis in spleen revealed selective loss of transcripts associated with the marginal zone and, in brain regions, the loss of known and candidate novel microglia-associated transcripts. Despite the complete absence of microglia, there was little overt phenotype in brain, aside from reduced myelination and increased expression of dopamine receptor-associated transcripts in striatum. The results highlight the redundant and nonredundant functions of CSF1R signaling and of macrophages in development, organogenesis, and homeostasis.
Location: United Kingdom of Great Britain and Northern Ireland
Start Date: 07-2021
End Date: 07-2024
Amount: $564,601.00
Funder: Australian Research Council
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