Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 18 de 18
Filter
Add more filters











Publication year range
1.
J Immunol ; 213(4): 456-468, 2024 Aug 15.
Article in English | MEDLINE | ID: mdl-38912868

ABSTRACT

Neutrophils play important roles in inflammatory airway diseases. In this study, we assessed whether apolipoprotein A-I modifies neutrophil heterogeneity as part of the mechanism by which it attenuates acute airway inflammation. Neutrophilic airway inflammation was induced by daily intranasal administration of LPS plus house dust mite (LPS+HDM) to Apoa1-/- and Apoa1+/+ mice for 3 d. Single-cell RNA sequencing was performed on cells recovered from bronchoalveolar lavage fluid on day 4. Unsupervised profiling identified 10 clusters of neutrophils in bronchoalveolar lavage fluid from Apoa1-/- and Apoa1+/+ mice. LPS+HDM-challenged Apoa1-/- mice had an increased proportion of the Neu4 neutrophil cluster that expressed S100a8, S100a9, and Mmp8 and had high maturation, aggregation, and TLR4 binding scores. There was also an increase in the Neu6 cluster of immature neutrophils, whereas neutrophil clusters expressing IFN-stimulated genes were decreased. An unsupervised trajectory analysis showed that Neu4 represented a distinct lineage in Apoa1-/- mice. LPS+HDM-challenged Apoa1-/- mice also had an increased proportion of recruited airspace macrophages, which was associated with a reciprocal reduction in resident airspace macrophages. Increased expression of a common set of proinflammatory genes, S100a8, S100a9, and Lcn2, was present in all neutrophils and airspace macrophages from LPS+HDM-challenged Apoa1-/- mice. These findings show that Apoa1-/- mice have increases in specific neutrophil and macrophage clusters in the lung during acute inflammation mediated by LPS+HDM, as well as enhanced expression of a common set of proinflammatory genes. This suggests that modifications in neutrophil and macrophage heterogeneity contribute to the mechanism by which apolipoprotein A-I attenuates acute airway inflammation.


Subject(s)
Apolipoprotein A-I , Mice, Knockout , Neutrophils , Pneumonia , Animals , Mice , Neutrophils/immunology , Pneumonia/immunology , Pneumonia/genetics , Apolipoprotein A-I/genetics , Mice, Inbred C57BL , Lipopolysaccharides/immunology , Bronchoalveolar Lavage Fluid/immunology , Bronchoalveolar Lavage Fluid/cytology , Lung/immunology , Lung/pathology , Calgranulin A , Calgranulin B
2.
Mol Ecol ; 33(14): e17432, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38887831

ABSTRACT

Atmospheric CO2 and temperature are rising concurrently, and may have profound impacts on the transcriptional, physiological and behavioural responses of aquatic organisms. Further, spring snowmelt may cause transient increases of pCO2 in many freshwater systems. We examined the behavioural, physiological and transcriptomic responses of an ancient fish, the lake sturgeon (Acipenser fulvescens) to projected levels of warming and pCO2 during its most vulnerable period of life, the first year. Specifically, larval fish were raised in either low (16°C) or high (22°C) temperature, and/or low (1000 µatm) or high (2500 µatm) pCO2 in a crossed experimental design over approximately 8 months. Following overwintering, lake sturgeon were exposed to a transient increase in pCO2 of 10,000 µatm, simulating a spring melt based on data in freshwater systems. Transcriptional analyses revealed potential connections to otolith formation and reduced growth in fish exposed to high pCO2 and temperature in combination. Network analyses of differential gene expression revealed different biological processes among the different treatments on the edges of transcriptional networks. Na+/K+-ATPase activity increased in fish not exposed to elevated pCO2 during development, and mRNA abundance of the ß subunit was most strongly predictive of enzyme activity. Behavioural assays revealed a decrease in total activity following an acute CO2 exposure. These results demonstrate compensatory and compounding mechanisms of pCO2 and warming dependent on developmental conditions in lake sturgeon. Conserved elements of the cellular stress response across all organisms provide key information for how other freshwater organisms may respond to future climate change.


Subject(s)
Carbon Dioxide , Fishes , Lakes , Temperature , Animals , Carbon Dioxide/metabolism , Fishes/genetics , Transcriptome , Climate Change , Sodium-Potassium-Exchanging ATPase/genetics , Sodium-Potassium-Exchanging ATPase/metabolism , Larva/genetics
3.
Cell Stem Cell ; 31(7): 974-988.e5, 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38843830

ABSTRACT

Cellular therapies with cardiomyocytes produced from induced pluripotent stem cells (iPSC-CMs) offer a potential route to cardiac regeneration as a treatment for chronic ischemic heart disease. Here, we report successful long-term engraftment and in vivo maturation of autologous iPSC-CMs in two rhesus macaques with small, subclinical chronic myocardial infarctions, all without immunosuppression. Longitudinal positron emission tomography imaging using the sodium/iodide symporter (NIS) reporter gene revealed stable grafts for over 6 and 12 months, with no teratoma formation. Histological analyses suggested capability of the transplanted iPSC-CMs to mature and integrate with endogenous myocardium, with no sign of immune cell infiltration or rejection. By contrast, allogeneic iPSC-CMs were rejected within 8 weeks of transplantation. This study provides the longest-term safety and maturation data to date in any large animal model, addresses concerns regarding neoantigen immunoreactivity of autologous iPSC therapies, and suggests that autologous iPSC-CMs would similarly engraft and mature in human hearts.


Subject(s)
Induced Pluripotent Stem Cells , Macaca mulatta , Myocytes, Cardiac , Animals , Induced Pluripotent Stem Cells/cytology , Induced Pluripotent Stem Cells/metabolism , Myocytes, Cardiac/metabolism , Myocytes, Cardiac/cytology , Cell Differentiation , Humans , Transplantation, Autologous , Positron-Emission Tomography , Time Factors , Myocardial Infarction/therapy , Myocardial Infarction/pathology
4.
Environ Sci Technol ; 58(18): 7998-8008, 2024 May 07.
Article in English | MEDLINE | ID: mdl-38629179

ABSTRACT

Understanding microplastic exposure and effects is critical to understanding risk. Here, we used large, in-lake closed-bottom mesocosms to investigate exposure and effects on pelagic freshwater ecosystems. This article provides details about the experimental design and results on the transport of microplastics and exposure to pelagic organisms. Our experiment included three polymers of microplastics (PE, PS, and PET) ranging in density and size. Nominal concentrations ranged from 0 to 29,240 microplastics per liter on a log scale. Mesocosms enclosed natural microbial, phytoplankton, and zooplankton communities and yellow perch (Perca flavescens). We quantified and characterized microplastics in the water column and in components of the food web (biofilm on the walls, zooplankton, and fish). The microplastics in the water stratified vertically according to size and density. After 10 weeks, about 1% of the microplastics added were in the water column, 0.4% attached to biofilm on the walls, 0.01% within zooplankton, and 0.0001% in fish. Visual observations suggest the remaining >98% were in a surface slick and on the bottom. Our study suggests organisms that feed at the surface and in the benthos are likely most at risk, and demonstrates the value of measuring exposure and transport to inform experimental designs and achieve target concentrations in different matrices within toxicity tests.


Subject(s)
Microplastics , Water Pollutants, Chemical , Zooplankton , Animals , Lakes , Ecosystem , Food Chain , Environmental Monitoring , Phytoplankton , Perches/metabolism
5.
Aquat Toxicol ; 270: 106885, 2024 May.
Article in English | MEDLINE | ID: mdl-38479125

ABSTRACT

Rising carbon dioxide (CO2) in aquatic ecosystems due to climate change is a challenge for aquatic ectotherms. We examined whether interindividual variation in behavioural responses to CO2 could predict how a teleost fish would respond to elevated CO2 for multiple phenotypic and molecular traits. To this end, we first quantified behavioural responses of individuals exposed to acute elevated CO2, and used these to assign individuals as either high or low responders relative to the population mean. Subsequently, we exposed both high and low responders to elevated CO2 for 6 weeks and quantified the effect on body condition, behaviour, and mRNA transcript responses of gill and liver genes associated with relevant physiological processes. Generally, we found few relationships between the phenotypic groups and body condition and behaviour following the CO2 exposure period; however, stark differences between the phenotypic groups with respect to gene transcripts from each tissue related to various processes were found, mostly independent of CO2 exposure. The most pronounced changes were in the gill transcripts related to acid-base regulation, suggesting that the observed behavioural variation used to assign fish to phenotypic groups may have an underlying molecular origin. Should the link between behaviour and gene transcripts be shown to have a fitness advantage and be maintained across generations, interindividual variation in behavioural responses to acute CO2 exposure may be a viable and non-invasive tool to predict future population responses to elevated aquatic CO2.


Subject(s)
Oryzias , Water Pollutants, Chemical , Animals , Oryzias/genetics , Carbon Dioxide/toxicity , RNA, Messenger/genetics , Ecosystem , Water Pollutants, Chemical/toxicity
6.
J Allergy Clin Immunol ; 153(4): 1010-1024.e14, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38092139

ABSTRACT

RATIONALE: Serum amyloid A (SAA) is bound to high-density lipoproteins (HDL) in blood. Although SAA is increased in the blood of patients with asthma, it is not known whether this modifies asthma severity. OBJECTIVE: We sought to define the clinical characteristics of patients with asthma who have high SAA levels and assess whether HDL from SAA-high patients with asthma is proinflammatory. METHODS: SAA levels in serum from subjects with and without asthma were quantified by ELISA. HDLs isolated from subjects with asthma and high SAA levels were used to stimulate human monocytes and were intravenously administered to BALB/c mice. RESULTS: An SAA level greater than or equal to 108.8 µg/mL was defined as the threshold to identify 11% of an asthmatic cohort (n = 146) as being SAA-high. SAA-high patients with asthma were characterized by increased serum C-reactive protein, IL-6, and TNF-α; older age; and an increased prevalence of obesity and severe asthma. HDL isolated from SAA-high patients with asthma (SAA-high HDL) had an increased content of SAA as compared with HDL from SAA-low patients with asthma and induced the secretion of IL-6, IL-1ß, and TNF-α from human monocytes via a formyl peptide receptor 2/ATP/P2X purinoceptor 7 axis. Intravenous administration to mice of SAA-high HDL, but not normal HDL, induced systemic inflammation and amplified allergen-induced neutrophilic airway inflammation and goblet cell metaplasia. CONCLUSIONS: SAA-high patients with asthma are characterized by systemic inflammation, older age, and an increased prevalence of obesity and severe asthma. HDL from SAA-high patients with asthma is proinflammatory and, when intravenously administered to mice, induces systemic inflammation, and amplifies allergen-induced neutrophilic airway inflammation. This suggests that systemic inflammation induced by SAA-high HDL may augment disease severity in asthma.


Subject(s)
Asthma , Lipoproteins, HDL , Humans , Animals , Mice , Lipoproteins, HDL/metabolism , Lipoproteins, HDL/pharmacology , Serum Amyloid A Protein/analysis , Serum Amyloid A Protein/metabolism , Serum Amyloid A Protein/pharmacology , Tumor Necrosis Factor-alpha/metabolism , Interleukin-6 , Inflammation/metabolism , Obesity , Allergens
7.
Conserv Physiol ; 11(1): coad065, 2023.
Article in English | MEDLINE | ID: mdl-37637261

ABSTRACT

Catch-and-release (C&R) angling is a conservation-oriented practice intended to reduce the impact recreational angling has on fish populations. Even though most recreationally angled fish are released, little is known about how C&R angling impacts fish at the cellular or tissue level. As the first to explore the impacts of C&R angling on mRNA abundances, our study aimed to identify how the stress of angling influenced metabolism, acid-base regulation and cellular stress in the gills of lake trout (Salvelinus namaycush). Because gills are responsible for metabolic gas exchange, are crucial sites of acid-base homeostasis and respond to stressors quickly, we hypothesized that the relative mRNA abundance of genes related to these three physiological processes would be altered after angling. We took gill samples of live lake trout at 0, 2 or 48 h after fish were angled by rod and reel, and then used quantitative PCR (qPCR) to measure the relative abundance of nine candidate mRNA transcripts. Heat shock protein 70 (hsp70) mRNA levels significantly increased over 5-fold 2 h after angling, indicating a potential activation of a cytoprotective response. However, contrary to our hypothesis, we observed no change in the relative mRNA abundance of genes related to metabolism or acid-base regulation in response to C&R angling within a 48-h period. As C&R angling can negatively impact fish populations, further use of transcript-level studies will allow us to understand the impact C&R has on specific tissues and improve our knowledge of how C&R influences overall fish health.

8.
Mol Ecol ; 32(13): 3403-3418, 2023 07.
Article in English | MEDLINE | ID: mdl-37118974

ABSTRACT

Predicting how quickly populations expand their range and whether they will retain genetic diversity when they are introduced to new regions or track environmental conditions suited to their survival is an important applied and theoretical challenge. The literature suggests that long-distance dispersal, landscape heterogeneity and the evolution of dispersal influence populations' expansion rates and genetic diversity. We used individual-based spatially explicit simulations to examine these relationships for Tench (Tinca tinca), an invasive fish expanding its geographical range in eastern North America since the 1990s. Simulated populations varied greatly in expansion rates (1.1-28.6 patches year-1 ) and genetic diversity metrics, including changes in observed heterozygosity (-19 to +0.8%) and effective number of alleles (-0.32 to -0.01). Populations with greater dispersal distances expanded faster than those with smaller dispersal distances but exhibited considerable variation in expansion rate among local populations, implying less predictable expansions. However, they tended to retain genetic diversity as they expanded, suggesting more predictable evolutionary trajectories. In contrast, populations with smaller dispersal distances spread predictably more slowly but exhibited more variability among local populations in genetic diversity losses. Consistent with empirical data, populations spreading in a longer, narrower dispersal corridor lost more neutral genetic variation to the stochastic fixation of alleles. Given the unprecedented pace of anthropogenic environmental change and the increasing need to manage range-expanding populations, our results have conservation ramifications as they imply that the evolutionary trajectories of populations characterised by shorter dispersal distances spreading in narrower landscapes are more variable and, therefore, less predictable.


Subject(s)
Cyprinidae , Animals , Cyprinidae/genetics , Heterozygote , Geography , Ecosystem
9.
Evol Appl ; 16(1): 173-188, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36699124

ABSTRACT

Introduced and geographically expanding populations experience similar eco-evolutionary challenges, including founder events, genetic bottlenecks, and novel environments. Theory predicts that reduced genetic diversity resulting from such phenomena limits the success of introduced populations. Using 1900 SNPs obtained from restriction-site-associated DNA sequencing, we evaluated hypotheses related to the invasion history and connectivity of an invasive population of Tench (Tinca tinca), a Eurasian freshwater fish that has been expanding geographically in eastern North America for three decades. Consistent with the reported history of a single introduction event, our findings suggest that multiple introductions from distinct genetic sources are unlikely as Tench had a small effective population size (~114 [95% CI = 106-123] individuals), no strong population subdivision across time and space, and evidence of a recent genetic bottleneck. The large genetic neighbourhood size (220 km) and weak within-population genetic substructure suggested high connectivity across the invaded range, despite the relatively large area occupied. There was some evidence for a small decay in genetic diversity as the species expanded northward, but not southward, into new habitats. As eradicating the species within a ~112 km radius would be necessary to prevent recolonization, eradicating Tench is likely not feasible at watershed-and possibly local-scales. Management should instead focus on reducing abundance in priority conservation areas to mitigate adverse impacts. Our study indicates that introduced populations can thrive and exhibit relatively high levels of genetic diversity despite severe bottlenecks (<1.5% of the ancestral effective population size) and suggests that landscape heterogeneity and population demographics can generate variability in spatial patterns of genetic diversity within a single range expansion.

10.
Physiol Biochem Zool ; 92(5): 505-529, 2019.
Article in English | MEDLINE | ID: mdl-31397628

ABSTRACT

Multiple stressors are commonly encountered by wild animals, but their cumulative effects are poorly understood, especially regarding infection development. We conducted a holding study with repeated gill and blood sampling to characterize the effects of cumulative stressors on infection development in adult coho salmon. Treatments included chronic thermal stress (15°C vs. 10°C) and acute gill net entanglement with an air exposure (simulating fisheries bycatch release). The potential loadings of 35 infectious agents and the expression of 17 host immune genes were quantified using high-throughput quantitative polymerase chain reaction, while host physiology was characterized with chemical analysis of blood. Temporal increases in infectious agent richness and loads were concurrent with decreased expression of immune genes in fish sampled in the river. In the laboratory, mortality was minimal in cool water regardless of fishery treatment (<15%). Elevated water temperature under laboratory conditions increased mortality of males and females (8% and 28% mortality, respectively, delayed by >1 wk) and enhanced mortality associated with handling and biopsy (∼40% both sexes). Experimental gillnetting at high temperature further enhanced female mortality (73%). Fish held at high temperature demonstrated heavier infectious agent loads, osmoregulatory impairment, suppressed female maturation, and upregulation of inflammatory and extracellular immune genes. At high temperature, heavy Parvicapsula minibicornis loads were associated with premature mortality. Females exhibited physiological impairment from both stressors after 1 wk, and infection burdens correlated poorly with immune gene regulation compared with males. Cumulative effects of multiple stressors on female mortality are likely a function of physiological impairment and enhanced infections at high temperature.


Subject(s)
Fish Diseases/etiology , Hot Temperature , Infections/veterinary , Longevity/physiology , Oncorhynchus kisutch/growth & development , Stress, Physiological , Animals , Ecosystem , Female , Male , Oncorhynchus kisutch/physiology
11.
J Allergy Clin Immunol ; 144(2): 426-441.e3, 2019 08.
Article in English | MEDLINE | ID: mdl-30872118

ABSTRACT

BACKGROUND: House dust mite (HDM)-challenged Apoe-/- mice display enhanced airway hyperreactivity and mucous cell metaplasia. OBJECTIVE: We sought to characterize the pathways that induce apolipoprotein E (APOE) expression by bronchoalveolar lavage fluid (BALF) macrophages from asthmatic subjects and identify how APOE regulates IL-1ß secretion. METHODS: Macrophages were isolated from asthmatic BALF and derived from THP-1 cells and human monocytes. RESULTS: HDM-derived cysteine and serine proteases induced APOE secretion from BALF macrophages through protease-activated receptor 2. APOE at concentrations of less than 2.5 nmol/L, which are similar to levels found in epithelial lining fluid from healthy adults, did not induce IL-1ß release from BALF macrophages. In contrast, APOE at concentrations of 25 nmol/L or greater induced nucleotide-binding oligomerization domain, leucine-rich repeat-containing protein (NLRP) 3 and pro-IL-1ß expression by BALF macrophages, as well as the caspase-1-mediated generation of mature IL-1ß secreted from cells. HDM acted synergistically with APOE to both prime and activate the NLRP3 inflammasome. In a murine model of neutrophilic airway inflammation induced by HDM and polyinosinic-polycytidylic acid, APOE reached a concentration of 32 nmol/L in epithelial lining fluid, with associated increases in BALF IL-1ß levels. APOE-dependent NLRP3 inflammasome activation in macrophages was primarily mediated through a potassium efflux-dependent mechanism. CONCLUSION: APOE can function as an endogenous, concentration-dependent pulmonary danger signal that primes and activates the NLPR3 inflammasome in BALF macrophages from asthmatic subjects to secrete IL-1ß. This might represent a mechanism through which APOE amplifies pulmonary inflammatory responses when concentrations in the lung are increased to greater than normal levels, which can occur during viral exacerbations of HDM-induced asthma characterized by neutrophilic airway inflammation.


Subject(s)
Apolipoproteins E/immunology , Asthma/immunology , Bronchoalveolar Lavage Fluid/immunology , Inflammasomes/immunology , Interleukin-1beta/immunology , Macrophages/immunology , NLR Family, Pyrin Domain-Containing 3 Protein/immunology , Signal Transduction/immunology , Animals , Asthma/pathology , Female , Humans , Macrophages/pathology , Male , Mice , THP-1 Cells
12.
BMC Genomics ; 19(1): 749, 2018 Oct 16.
Article in English | MEDLINE | ID: mdl-30326831

ABSTRACT

BACKGROUND: Pacific salmon (Oncorhynchus spp.) serve as good biological indicators of the breadth of climate warming effects on fish because their anadromous life cycle exposes them to environmental challenges in both marine and freshwater environments. Our study sought to mine the extensive functional genomic studies in fishes to identify robust thermally-responsive biomarkers that could monitor molecular physiological signatures of chronic thermal stress in fish using non-lethal sampling of gill tissue. RESULTS: Candidate thermal stress biomarkers for gill tissue were identified using comparisons among microarray datasets produced in the Molecular Genetics Laboratory, Pacific Biological Station, Nanaimo, BC, six external, published microarray studies on chronic and acute temperature stress in salmon, and a comparison of significant genes across published studies in multiple fishes using deep literature mining. Eighty-two microarray features related to 39 unique gene IDs were selected as candidate chronic thermal stress biomarkers. Most of these genes were identified both in the meta-analysis of salmon microarray data and in the literature mining for thermal stress markers in salmonids and other fishes. Quantitative reverse transcription PCR (qRT-PCR) assays for 32 unique genes with good efficiencies across salmon species were developed, and their activity in response to thermally challenged sockeye salmon (O. nerka) and Chinook salmon (O. tshawytscha) (cool, 13-14 °C and warm temperatures 18-19 °C) over 5-7 days was assessed. Eight genes, including two transcripts of each SERPINH1 and HSP90AA1, FKBP10, MAP3K14, SFRS2, and EEF2 showed strong and robust chronic temperature stress response consistently in the discovery analysis and both sockeye and Chinook salmon validation studies. CONCLUSIONS: The results of both discovery analysis and gene expression showed that a panel of genes involved in chaperoning and protein rescue, oxidative stress, and protein biosynthesis were differentially activated in gill tissue of Pacific salmon in response to elevated temperatures. While individually, some of these biomarkers may also respond to other stressors or biological processes, when expressed in concert, we argue that a biomarker panel comprised of some or all of these genes could provide a reliable means to specifically detect thermal stress in field-caught salmon.


Subject(s)
Genetic Markers/genetics , Heat-Shock Response/genetics , Salmonidae/genetics , Salmonidae/physiology , Animals , Gene Expression Profiling , Genetic Profile , Gills/metabolism
13.
J Allergy Clin Immunol ; 142(4): 1066-1079.e6, 2018 10.
Article in English | MEDLINE | ID: mdl-29274414

ABSTRACT

BACKGROUND: Low-density lipoprotein receptor-related protein 1 (LRP-1) is a scavenger receptor that regulates adaptive immunity and inflammation. LRP-1 is not known to modulate the pathogenesis of allergic asthma. OBJECTIVE: We sought to assess whether LRP-1 expression by dendritic cells (DCs) modulates adaptive immune responses in patients with house dust mite (HDM)-induced airways disease. METHODS: LRP-1 expression on peripheral blood DCs was quantified by using flow cytometry. The role of LRP-1 in modulating HDM-induced airways disease was assessed in mice with deletion of LRP-1 in CD11c+ cells (Lrp1fl/fl; CD11c-Cre) and by adoptive transfer of HDM-pulsed CD11b+ DCs from Lrp1fl/fl; CD11c-Cre mice to wild-type (WT) mice. RESULTS: Human peripheral blood myeloid DC subsets from patients with eosinophilic asthma have lower LRP-1 expression than cells from healthy nonasthmatic subjects. Similarly, LRP-1 expression by CD11b+ lung DCs was significantly reduced in HDM-challenged WT mice. HDM-challenged Lrp1fl/fl; CD11c-Cre mice have a phenotype of increased eosinophilic airway inflammation, allergic sensitization, TH2 cytokine production, and mucous cell metaplasia. The adoptive transfer of HDM-pulsed LRP-1-deficient CD11b+ DCs into WT mice generated a similar phenotype of enhanced eosinophilic inflammation and allergic sensitization. Furthermore, CD11b+ DCs in the lungs of Lrp1fl/fl; CD11c-Cre mice have an increased ability to take up HDM antigen, whereas bone marrow-derived DCs display enhanced antigen presentation capabilities. CONCLUSION: This identifies a novel role for LRP-1 as a negative regulator of DC-mediated adaptive immune responses in the setting of HDM-induced eosinophilic airway inflammation. Furthermore, the reduced LRP-1 expression by circulating myeloid DCs in patients with eosinophilic asthma suggests a possible role for LRP-1 in modulating type 2-high asthma.


Subject(s)
Asthma/immunology , Dendritic Cells/immunology , Dermatophagoides pteronyssinus/immunology , Eosinophilia/immunology , Low Density Lipoprotein Receptor-Related Protein-1/immunology , Adaptive Immunity , Adult , Allergens/immunology , Animals , Antigens, Dermatophagoides/immunology , Asthma/blood , Asthma/physiopathology , Bronchoalveolar Lavage Fluid/cytology , Eosinophilia/blood , Eosinophilia/physiopathology , Female , Humans , Immunoglobulin E/blood , Immunoglobulin G/blood , Male , Mice, Transgenic , Middle Aged
14.
J Vis Exp ; (128)2017 10 09.
Article in English | MEDLINE | ID: mdl-29053673

ABSTRACT

Cardiovascular disease remains the number one cause of mortality in the United States. There are numerous approaches to treating these diseases, but regardless of the approach, an in vivo model is needed to test each treatment. The pig is one of the most used large animal models for cardiovascular disease. Its heart is very similar in anatomy and function to that of a human. The ameroid placement technique creates an ischemic area of the heart, which has many useful applications in studying myocardial infarction. This model has been used for surgical research, pharmaceutical studies, imaging techniques, and cell therapies. There are several ways of inducing an ischemic area in the heart. Each has its advantages and disadvantages, but the placement of an ameroid constrictor remains the most widely used technique. The main advantages to using the ameroid are its prevalence in existing research, its availability in various sizes to accommodate the anatomy and size of the vessel to be constricted, the surgery is a relatively simple procedure, and the post-operative monitoring is minimal, since there are no external devices to maintain. This paper provides a detailed overview of the proper technique for the placement of the ameroid constrictor.


Subject(s)
Caseins/pharmacology , Hydrogels/pharmacology , Myocardial Ischemia/physiopathology , Animals , Chronic Disease , Disease Models, Animal , Humans , Swine
15.
Integr Comp Biol ; 55(4): 554-76, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26199324

ABSTRACT

Acute stressors are commonly experienced by wild animals but their effects on fitness rarely are studied in the natural environment. Billions of fish are captured and released annually around the globe across all fishing sectors (e.g., recreational, commercial, subsistence). Whatever the motivation, release often occurs under the assumption of post-release survival. Yet, capture by fisheries (hereafter "fisheries-capture") is likely the most severe acute stressor experienced in the animal's lifetime, which makes the problem of physiological recovery and survival of relevance to biology and conservation. Indeed, fisheries managers require accurate estimates of mortality to better account for total mortality from fishing, while fishers desire guidance on strategies for reducing mortality and maintaining the welfare of released fish, to maximize current and future opportunities for fishing. In partnership with stakeholders, our team has extensively studied the effects of catch-and-release on Pacific salmon in both marine and freshwater environments, using biotelemetry and physiological assessments in a combined laboratory-based and field-based approach. The emergent theme is that post-release rates of mortality are consistently context-specific and can be affected by a suite of interacting biotic and abiotic factors. The fishing gear used, location of a fishery, water temperature, and handling techniques employed by fishers each can dramatically affect survival of the salmon they release. Variation among individuals, co-migrating populations, and between sexes all seem to play a role in the response of fish to capture and in their subsequent survival, potentially driven by pre-capture pathogen-load, maturation states, and inter-individual variation in responsiveness to stress. Although some of these findings are fascinating from a biological perspective, they all create unresolved challenges for managers. We summarize our findings by highlighting the patterns that have emerged most consistently, and point to areas of uncertainty that require further research.


Subject(s)
Conservation of Natural Resources/methods , Salmon/physiology , Animals , Fisheries , Stress, Physiological , Survival Analysis
16.
Nat Commun ; 6: 6224, 2015 Feb 18.
Article in English | MEDLINE | ID: mdl-25692509

ABSTRACT

DNA-dependent protein kinase (DNA-PK) mediates double-stranded DNA break repair, V(D)J recombination and immunoglobulin class switch recombination, as well as innate immune and pro-inflammatory responses. However, there is limited information regarding the role of DNA-PK in adaptive immunity mediated by dendritic cells (DCs), which are the primary antigen-presenting cells in allergic asthma. Here we show that house dust mite induces DNA-PK phosphorylation, which is a marker of DNA-PK activation, in DCs via the generation of intracellular reactive oxygen species. We also demonstrate that pharmacological inhibition of DNA-PK, as well as the specific deletion of DNA-PK in DCs, attenuates the induction of allergic sensitization and Th2 immunity via a mechanism that involves the impaired presentation of mite antigens. Furthermore, pharmacological inhibition of DNA-PK following antigen priming similarly reduces the manifestations of mite-induced airway disease. Collectively, these findings suggest that DNA-PK may be a potential target for treatment of allergic asthma.


Subject(s)
DNA-Activated Protein Kinase/metabolism , DNA-Binding Proteins/metabolism , Dendritic Cells/immunology , Inflammation/immunology , Nuclear Proteins/metabolism , Th2 Cells/immunology , Adaptive Immunity , Administration, Oral , Animals , Antigen Presentation , Asthma/immunology , CD11c Antigen/metabolism , Chromones/chemistry , Dendritic Cells/parasitology , Female , Hypersensitivity/immunology , Immunoglobulin E/immunology , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Knockout , Mice, SCID , Morpholines/chemistry , Phosphorylation , Pyroglyphidae , Reactive Oxygen Species/metabolism , Th2 Cells/parasitology
17.
J Anat ; 220(5): 514-24, 2012 May.
Article in English | MEDLINE | ID: mdl-22360411

ABSTRACT

The high spatial resolution of micro-computed tomography (micro-CT) is ideal for 3D imaging of coronary arteries in intact mouse heart specimens. Previously, micro-CT of mouse heart specimens utilized intravascular contrast agents that hardened within the vessel lumen and allowed a vascular cast to be made. However, for mouse coronary artery disease models, it is highly desirable to image coronary artery walls and highlight plaques. For this purpose, we describe an ex vivo contrast-enhanced micro-CT imaging technique based on tissue staining with osmium tetroxide (OsO(4) ) solution. As a tissue-staining contrast agent, OsO(4) is retained in the vessel wall and surrounding tissue during the fixation process and cleared from the vessel lumens. Its high X-ray attenuation makes the artery wall visible in CT. Additionally, since OsO(4) preferentially binds to lipids, it highlights lipid deposition in the artery wall. We performed micro-CT of heart specimens of 5- to 25-week-old C57BL/6 wild-type mice and 5- to 13-week-old apolipoprotein E knockout (apoE(-/-) ) mice at 10 µm resolution. The results show that walls of coronary arteries as small as 45 µm in diameter are visible using a table-top micro-CT scanner. Similar image clarity was achieved with 1/2000th the scan time using a synchrotron CT scanner. In 13-week-old apoE mice, lipid-rich plaques are visible in the aorta. Our study shows that the combination of OsO(4) and micro-CT permits the visualization of the coronary artery wall in intact mouse hearts.


Subject(s)
Coronary Vessels/anatomy & histology , Osmium Tetroxide , X-Ray Microtomography/methods , Animals , Female , Male , Mice , Mice, Inbred C57BL
18.
J Exp Biol ; 214(Pt 18): 3074-81, 2011 Sep 15.
Article in English | MEDLINE | ID: mdl-21865520

ABSTRACT

Little is known of the physiological mechanisms underlying the effects of climate change on animals, yet it is clear that some species appear more resilient than others. As pink salmon (Oncorhynchus gorbuscha) in British Columbia, Canada, have flourished in the current era of climate warming in contrast to other Pacific salmonids in the same watershed, this study investigated whether the continuing success of pink salmon may be linked with exceptional cardiorespiratory adaptations and thermal tolerance of adult fish during their spawning migration. Sex-specific differences existed in minimum and maximum oxygen consumption rates (M(O2,min) and M(O2,max), respectively) across the temperature range of 8 to 28°C, reflected in a higher aerobic scope (M(O2,max)-M(O2,min)) for males. Nevertheless, the aerobic scope of both sexes was optimal at 21°C (T(opt)) and was elevated across the entire temperature range in comparison with other Pacific salmonids. As T(opt) for aerobic scope of this pink salmon population is higher than in other Pacific salmonids, and historic river temperature data reveal that this population rarely encounters temperatures exceeding T(opt), these findings offer a physiological explanation for the continuing success of this species throughout the current climate-warming period. Despite this, declining cardiac output was evident above 17°C, and maximum attainable swimming speed was impaired above ∼23°C, suggesting negative implications under prolonged thermal exposure. While forecasted summer river temperatures over the next century are likely to negatively impact all Pacific salmonids, we suggest that the cardiorespiratory capacity of pink salmon may confer a selective advantage over other species.


Subject(s)
Adaptation, Physiological/physiology , Global Warming , Heart/physiology , Salmon/physiology , Aerobiosis , Animals , British Columbia , Cardiac Output/physiology , Female , Geography , Male , Oxygen/metabolism , Oxygen Consumption/physiology , Respiratory Physiological Phenomena , Temperature , Water
SELECTION OF CITATIONS
SEARCH DETAIL