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1.
J Acoust Soc Am ; 152(6): 3170, 2022 12.
Article in English | MEDLINE | ID: mdl-36586823

ABSTRACT

During the COVID-19 pandemic, changes in vessel activity and associated noise have been reported globally. Sarasota Bay is home to a large and increasing number of recreational vessels as well as a long-term resident community of bottlenose dolphins, Tursiops truncatus. Data were analyzed from two hydrophones to compare the soundscape during the COVID-19 pandemic to previous years (March-May 2020 and 2018/2019). Hourly metrics were calculated: vessel passes, 95th percentile sound levels [125 Hz and 16 kHz third octave bands (TOBs), and two broader bands: 88-1122 Hz and 1781-17 959 Hz], and dolphin whistle detection to understand changes in vessel activity and the effect on wildlife. Vessel activity increased during COVID-19 restrictions by almost 80% at one site and remained the same at the other site. Of the four sound level measures, only the 125 Hz TOB and 88-1122 Hz band increased with vessel activity at both sites, suggesting that these may be appropriate measures of noise from rapid pass-bys of small vessels in very shallow (<10 m) habitats. Dolphin whistle detection decreased during COVID-19 restrictions at one site but remained the same at the site that experienced increased vessel activity. The results suggest that pandemic effects on wildlife should not be viewed as homogeneous globally.


Subject(s)
Bottle-Nosed Dolphin , COVID-19 , Animals , Humans , Pandemics , Bays , COVID-19/epidemiology , Ecosystem , Animals, Wild
2.
Sci Rep ; 10(1): 21708, 2020 12 10.
Article in English | MEDLINE | ID: mdl-33303921

ABSTRACT

MicroRNAs are small (~ 22nt long) noncoding RNAs (ncRNAs) that regulate gene expression at the post-transcriptional level. Over 2000 microRNAs have been described in humans and many are implicated in human pathologies including tissue fibrosis. Hepatic stellate cells (HSC) are the major cellular contributors to excess extracellular matrix deposition in the diseased liver and as such are important in the progression of liver fibrosis. We employed next generation sequencing to map alterations in the expression of microRNAs occurring across a detailed time course of culture-induced transdifferentiation of primary human HSC, this a key event in fibrogenesis. Furthermore, we compared profiling of human HSC microRNAs with that of rat HSC so as to identify those molecules that are conserved with respect to modulation of expression. Our analysis reveals that a total of 229 human microRNAs display altered expression as a consequence of HSC transdifferentiation and of these 104 were modulated early during the initiation phase. Typically modulated microRNAs were targeting kinases, transcription factors, chromatin factors, cell cycle regulators and growth factors. 162 microRNAs changed in expression during transdifferentiation of rat HSC, however only 17 underwent changes that were conserved in human HSC. Our study therefore identifies widespread changes in the expression of HSC microRNAs in fibrogenesis, but suggests a need for caution when translating data obtained from rodent HSC to events occurring in human cells.


Subject(s)
Base Sequence , Cell Transdifferentiation/genetics , Hepatic Stellate Cells/physiology , MicroRNAs/genetics , MicroRNAs/metabolism , Sequence Analysis, RNA/methods , Animals , Cells, Cultured , Fibrosis/genetics , Gene Expression , Hepatic Stellate Cells/pathology , Humans , Male , Phenotype , Rats, Sprague-Dawley
3.
Rhinology ; 58(6): 581-587, 2020 Dec 01.
Article in English | MEDLINE | ID: mdl-32812016

ABSTRACT

BACKGROUND: Chronic rhinosinusitis is an inflammatory condition with an as yet unknown pathophysiology. We aimed to detect clusters of differentially regulated genes in the epithelial and fibroblast cells of patients with Chronic Rhinosinusitis without nasal polyposis (CRSsNP) and healthy controls. METHODOLOGY: Carefully phenotyped CRSsNP and healthy control participants were recruited. Primary cultures of isolated epithelial and fibroblast cells were established. Whole transcriptome analysis of the cells was performed using microarrays and replicated with quantitative RT-PCR and immunohistochemistry. RESULTS: Fibroblast cells from CRSsNP patients showed a significant upregulation (more than 2x) of the transcription factor NFE2L3 when compared to healthy controls by microarray with multiple hypothesis testing correction, qRT-PCR and immunohistochemistry. CONCLUSIONS: Here we have utilized microarray analysis to search for differentially expressed genes in isolated patient derived epithelial and fibroblast cells. The transcription factor NFE2L3 has been shown to be upregulated in fibroblast cells consistent with increasing evidence that fibroblasts play a key role in tissue specific inflammation within the paranasal sinuses.


Subject(s)
Nasal Polyps , Rhinitis , Sinusitis , Chronic Disease , Fibroblasts , Humans , Microarray Analysis
4.
Bone Joint J ; 98-B(11): 1479-1488, 2016 Nov.
Article in English | MEDLINE | ID: mdl-27803223

ABSTRACT

AIMS: The aim of this consensus was to develop a definition of post-operative fibrosis of the knee. PATIENTS AND METHODS: An international panel of experts took part in a formal consensus process composed of a discussion phase and three Delphi rounds. RESULTS: Post-operative fibrosis of the knee was defined as a limited range of movement (ROM) in flexion and/or extension, that is not attributable to an osseous or prosthetic block to movement from malaligned, malpositioned or incorrectly sized components, metal hardware, ligament reconstruction, infection (septic arthritis), pain, chronic regional pain syndrome (CRPS) or other specific causes, but due to soft-tissue fibrosis that was not present pre-operatively. Limitation of movement was graded as mild, moderate or severe according to the range of flexion (90° to 100°, 70° to 89°, < 70°) or extension deficit (5° to 10°, 11° to 20°, > 20°). Recommended investigations to support the diagnosis and a strategy for its management were also agreed. CONCLUSION: The development of standardised, accepted criteria for the diagnosis, classification and grading of the severity of post-operative fibrosis of the knee will facilitate the identification of patients for inclusion in clinical trials, the development of clinical guidelines, and eventually help to inform the management of this difficult condition. Cite this article: Bone Joint J 2016;98-B:1479-88.


Subject(s)
Knee Joint/pathology , Knee Joint/surgery , Postoperative Complications/diagnosis , Algorithms , Consensus , Fibrosis , Humans , Knee Joint/physiopathology , Postoperative Complications/classification , Postoperative Complications/physiopathology , Postoperative Complications/therapy , Range of Motion, Articular , Registries , Severity of Illness Index
6.
Oncogene ; 35(35): 4623-32, 2016 09 01.
Article in English | MEDLINE | ID: mdl-26853469

ABSTRACT

Post-translational modifications of nuclear factor (NF)-κB subunits provide a mechanism to differentially regulate their activity in response to the many stimuli that induce this pathway. However, the physiological significance of these modifications is largely unknown, and it remains unclear if these have a critical role in the normal and pathological functions of NF-κB in vivo. Among these, phosphorylation of the RelA(p65) Thr505 residue has been described as an important regulator of NF-κB activity in cell lines, but its physiological significance was not known. Therefore, to learn more about the role of this pathway in vivo, we generated a knockin mouse with a RelA T505A mutation. Unlike RelA knockout mice, the RelA T505A mice develop normally but exhibit aberrant hepatocyte proliferation following liver partial hepatectomy or damage resulting from carbon tetrachloride (CCl4) treatment. Consistent with these effects, RelA T505A mice exhibit earlier onset of cancer in the N-nitrosodiethylamine model of hepatocellular carcinoma. These data reveal a critical pathway controlling NF-κB function in the liver that acts to suppress the tumour-promoting activities of RelA.


Subject(s)
Apoptosis/genetics , Liver Neoplasms/genetics , Liver Regeneration/genetics , NF-kappa B/genetics , Transcription Factor RelA/genetics , Animals , Carbon Tetrachloride/toxicity , Cell Proliferation/drug effects , Gene Knock-In Techniques , Hepatocytes/drug effects , Hepatocytes/pathology , Humans , Liver Neoplasms/chemically induced , Liver Neoplasms/pathology , Mice , Mice, Knockout , Mutation/genetics , Phosphorylation/genetics
7.
Am J Transplant ; 16(6): 1751-65, 2016 06.
Article in English | MEDLINE | ID: mdl-26714197

ABSTRACT

Bacterial infections after lung transplantation cause airway epithelial injury and are associated with an increased risk of developing bronchiolitis obliterans syndrome. The damaged epithelium is a source of alarmins that activate the innate immune system, yet their ability to activate fibroblasts in the development of bronchiolitis obliterans syndrome has not been evaluated. Two epithelial alarmins were measured longitudinally in bronchoalveolar lavages from lung transplant recipients who developed bronchiolitis obliterans syndrome and were compared to stable controls. In addition, conditioned media from human airway epithelial cells infected with Pseudomonas aeruginosa was applied to lung fibroblasts and inflammatory responses were determined. Interleukin-1 alpha (IL-1α) was increased in bronchoalveolar lavage of lung transplant recipients growing P. aeruginosa (11.5 [5.4-21.8] vs. 2.8 [0.9-9.4] pg/mL, p < 0.01) and was significantly elevated within 3 months of developing bronchiolitis obliterans syndrome (8.3 [1.4-25.1] vs. 3.6 [0.6-17.1] pg/mL, p < 0.01), whereas high mobility group protein B1 remained unchanged. IL-1α positively correlated with elevated bronchoalveolar lavage IL-8 levels (r(2)  = 0.6095, p < 0.0001) and neutrophil percentage (r(2)  = 0.25, p = 0.01). Conditioned media from P. aeruginosa infected epithelial cells induced a potent pro-inflammatory phenotype in fibroblasts via an IL-1α/IL-1R-dependent signaling pathway. In conclusion, we propose that IL-1α may be a novel therapeutic target to limit Pseudomonas associated allograft injury after lung transplantation.


Subject(s)
Acute Lung Injury/etiology , Bronchiolitis Obliterans/etiology , Epithelial Cells/microbiology , Fibroblasts/pathology , Graft Rejection/etiology , Lung Transplantation/adverse effects , Pseudomonas aeruginosa/pathogenicity , Respiratory Mucosa/microbiology , Acute Lung Injury/pathology , Adult , Allografts , Bronchiolitis Obliterans/pathology , Bronchoalveolar Lavage Fluid , Epithelial Cells/immunology , Epithelial Cells/pathology , Female , Graft Rejection/pathology , Humans , Inflammation/etiology , Inflammation/pathology , Interleukin-1alpha/immunology , Male , Middle Aged , Neutrophils/immunology , Pseudomonas Infections/complications , Pseudomonas Infections/microbiology , Respiratory Mucosa/immunology , Respiratory Mucosa/pathology , Retrospective Studies , Young Adult
9.
Nat Commun ; 6: 6818, 2015 Apr 16.
Article in English | MEDLINE | ID: mdl-25879839

ABSTRACT

Hepatocellular carcinoma (HCC) develops on the background of chronic hepatitis. Leukocytes found within the HCC microenvironment are implicated as regulators of tumour growth. We show that diethylnitrosamine (DEN)-induced murine HCC is attenuated by antibody-mediated depletion of hepatic neutrophils, the latter stimulating hepatocellular ROS and telomere DNA damage. We additionally report a previously unappreciated tumour suppressor function for hepatocellular nfkb1 operating via p50:p50 dimers and the co-repressor HDAC1. These anti-inflammatory proteins combine to transcriptionally repress hepatic expression of a S100A8/9, CXCL1 and CXCL2 neutrophil chemokine network. Loss of nfkb1 promotes ageing-associated chronic liver disease (CLD), characterized by steatosis, neutrophillia, fibrosis, hepatocyte telomere damage and HCC. Nfkb1(S340A/S340A)mice carrying a mutation designed to selectively disrupt p50:p50:HDAC1 complexes are more susceptible to HCC; by contrast, mice lacking S100A9 express reduced neutrophil chemokines and are protected from HCC. Inhibiting neutrophil accumulation in CLD or targeting their tumour-promoting activities may offer therapeutic opportunities in HCC.


Subject(s)
Carcinoma, Hepatocellular/genetics , Liver Neoplasms, Experimental/genetics , NF-kappa B p50 Subunit/genetics , Neutrophils/immunology , Alkylating Agents/toxicity , Animals , Calgranulin A/genetics , Calgranulin B/genetics , Carcinoma, Hepatocellular/chemically induced , Carcinoma, Hepatocellular/immunology , Chemokine CXCL1/genetics , Chemokine CXCL2/genetics , Diethylnitrosamine/toxicity , Liver Diseases/genetics , Liver Diseases/immunology , Liver Neoplasms, Experimental/chemically induced , Liver Neoplasms, Experimental/immunology , Mice , Mice, Knockout , Mutation
10.
J Fish Biol ; 85(5): 1470-88, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25141790

ABSTRACT

The goals of this project were to determine the daily, seasonal and spatial patterns of red grouper Epinephelus morio sound production on the West Florida Shelf (WFS) using passive acoustics. An 11 month time series of acoustic data from fixed recorders deployed at a known E. morio aggregation site showed that E. morio produce sounds throughout the day and during all months of the year. Increased calling (number of files containing E. morio sound) was correlated to sunrise and sunset, and peaked in late summer (July and August) and early winter (November and December). Due to the ubiquitous production of sound, large-scale spatial mapping across the WFS of E. morio sound production was feasible using recordings from shorter duration-fixed location recorders and autonomous underwater vehicles (AUVs). Epinephelus morio were primarily recorded in waters 15-93 m deep, with increased sound production detected in hard bottom areas and within the Steamboat Lumps Marine Protected Area (Steamboat Lumps). AUV tracks through Steamboat Lumps, an offshore marine reserve where E. morio hole excavations have been previously mapped, showed that hydrophone-integrated AUVs could accurately map the location of soniferous fish over spatial scales of <1 km. The results show that passive acoustics is an effective, non-invasive tool to map the distribution of this species over large spatial scales.


Subject(s)
Perciformes/physiology , Sound , Vocalization, Animal , Acoustics , Animals , Circadian Rhythm , Ecosystem , Florida , Seasons , Spatio-Temporal Analysis
11.
Mucosal Immunol ; 7(3): 684-93, 2014 May.
Article in English | MEDLINE | ID: mdl-24172847

ABSTRACT

Activation of the innate immune system plays a key role in exacerbations of chronic lung disease, yet the potential role of lung fibroblasts in innate immunity and the identity of epithelial danger signals (alarmins) that may contribute to this process are unclear. The objective of the study was to identify lung epithelial-derived alarmins released during endoplasmic reticulum stress (ER stress) and oxidative stress and evaluate their potential to induce innate immune responses in lung fibroblasts. We found that treatment of primary human lung fibroblasts (PHLFs) with conditioned media from damaged lung epithelial cells significantly upregulated interleukin IL-6, IL-8, monocyte chemotactic protein-1, and granulocyte macrophage colony-stimulating factor expression (P<0.05). This effect was reduced with anti-IL-1α or IL-1Ra but not anti-IL-1ß antibody. Costimulation with a Toll-like receptor 3 ligand, polyinosinic-polycytidylic acid (poly I:C), significantly accentuated the IL-1α-induced inflammatory phenotype in PHLFs, and this effect was blocked with inhibitor of nuclear factor kappa-B kinase subunit beta and TGFß-activated kinase-1 inhibitors. Finally, Il1r1-/- and Il1a-/- mice exhibit reduced bronchoalveolar lavage (BAL) neutrophilia and collagen deposition in response to bleomycin treatment. We conclude that IL-1α plays a pivotal role in triggering proinflammatory responses in fibroblasts and this process is accentuated in the presence of double-stranded RNA. This mechanism may be important in the repeated cycles of injury and exacerbation in chronic lung disease.


Subject(s)
Epithelial Cells/metabolism , Fibroblasts/metabolism , Interleukin-1alpha/metabolism , Pneumonia/metabolism , Animals , Cell Line , Cells, Cultured , Culture Media, Conditioned/pharmacology , Cytokines/metabolism , Disease Models, Animal , Endoplasmic Reticulum Stress , Epithelial Cells/pathology , Fibroblasts/drug effects , Humans , Inflammation Mediators/metabolism , Interleukin-1alpha/genetics , Mice , Mice, Knockout , NF-kappa B/metabolism , Oxidative Stress , Phenotype , Pneumonia/drug therapy , Pneumonia/genetics , Pneumonia/pathology , Receptors, Interleukin-1 Type I/genetics , Receptors, Interleukin-1 Type I/metabolism , Signal Transduction
12.
Br J Cancer ; 109(9): 2396-403, 2013 Oct 29.
Article in English | MEDLINE | ID: mdl-24113143

ABSTRACT

BACKGROUND: Chemotherapy-associated liver injury (CALI) has been linked to increased morbidity and poorer disease-specific outcomes in patients undergoing resection of colorectal liver metastases (CRLM). The aim of this study was to assess the contribution of tumour-related factors to the development of FOLFOX-induced liver injury. METHODS: We assessed the effect of FOLFOX treatment on the murine liver either in the presence or absence of CRLM to evaluate the contribution of both chemotherapy and tumour death to the development of CALI. RESULTS: In the presence of liver metastases, there was increased hepatic expression of plasminogen activator inhibitor-1 (146-fold; P<0.01) and vWF (2.4-fold; P<0.01) transcript as compared with sham-operated controls. In addition, we detected large clusters of megakaryocytes in the spleen of FOLFOX-treated tumour-bearing animals. The livers of FOLFOX-treated animals also showed changes in matrix remodelling genes such as TGFß (P<0.01), MMP2 (P<0.001), TIMP1 (P<0.001) and Pro-Collagen I (P<0.05) which was exacerbated in the presence of tumour. These genes have previously been demonstrated to have a key role in FOLFOX-induced liver injury. CONCLUSION: It appears that the toxicity of FOLFOX chemotherapy is enhanced by tumour-related factors.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/adverse effects , Antineoplastic Combined Chemotherapy Protocols/pharmacology , Chemical and Drug Induced Liver Injury/genetics , Hepatic Veno-Occlusive Disease/chemically induced , Hepatic Veno-Occlusive Disease/genetics , Animals , Cell Line, Tumor , Collagen Type I/genetics , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/genetics , Fluorouracil/adverse effects , Fluorouracil/pharmacology , Inflammation/genetics , Leucovorin/adverse effects , Leucovorin/pharmacology , Liver/drug effects , Liver Neoplasms/drug therapy , Liver Neoplasms/genetics , Liver Neoplasms/secondary , Matrix Metalloproteinase 2/genetics , Megakaryocytes/drug effects , Mice , Mice, Inbred C57BL , Organoplatinum Compounds/adverse effects , Organoplatinum Compounds/pharmacology , Plasminogen Activator Inhibitor 1/genetics , Spleen/drug effects , Tissue Inhibitor of Metalloproteinase-1/genetics , Transforming Growth Factor beta/genetics
13.
J Hepatol ; 59(2): 318-26, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23624001

ABSTRACT

BACKGROUND & AIMS: Sinusoidal obstruction syndrome (SOS) following oxaliplatin based chemotherapy can have a significant impact on post-operative outcome following resection of colorectal liver metastases. To date no relevant experimental models of oxaliplatin induced SOS have been described. The aim of this project was to establish a rodent model which could be utilised to investigate mechanisms underlying SOS to aid the development of therapeutic strategies. METHODS: C57Bl/6 mice, maintained on a purified diet, were treated with intra-peritoneal FOLFOX (n=10), or vehicle (n=10), weekly for five weeks and culled one week following final treatment. Sections of the liver and spleen were fixed in formalin and paraffin embedded for histological analysis. The role of oxidative stress on experimental-induced SOS was determined by dietary supplementation with butylated hydroxyanisole and N-acetylcysteine. RESULTS: FOLFOX treatment was associated with the development of sinusoidal dilatation and hepatocyte atrophy on H&E stained sections of the liver in keeping with SOS. Immunohistochemistry for p21 demonstrated the presence of replicative senescence within the sinusoidal endothelium. FOLFOX induced endothelial damage leads to a pro-thrombotic state within the liver associated with upregulation of PAI-1 (p<0.001), vWF (p<0.01) and Factor X (p<0.001), which may contribute to the propagation of liver injury. Dietary supplementation with the antioxidant BHA prevented the development of significant SOS. CONCLUSIONS: We have developed the first reproducible model of chemotherapy induced SOS that reflects the pathogenesis of this disease in patients. It appears that the use of antioxidants alongside oxaliplatin based chemotherapy may be of value in preventing the development of SOS in patients with colorectal liver metastases.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/toxicity , Hepatic Veno-Occlusive Disease/chemically induced , Organoplatinum Compounds/toxicity , Animals , Antioxidants/administration & dosage , Cell Cycle , Colorectal Neoplasms/drug therapy , Cyclin-Dependent Kinase Inhibitor p21/genetics , Cyclin-Dependent Kinase Inhibitor p21/metabolism , Cytokines/genetics , Cytokines/metabolism , Disease Models, Animal , Fluorouracil/toxicity , Hepatic Veno-Occlusive Disease/metabolism , Hepatic Veno-Occlusive Disease/pathology , Humans , Inflammation Mediators/metabolism , Leucovorin/toxicity , Liver Cirrhosis/chemically induced , Liver Neoplasms/drug therapy , Liver Neoplasms/secondary , Liver Neoplasms/surgery , Mice , Mice, Inbred C57BL , Neovascularization, Pathologic/chemically induced , Oxaliplatin , Oxidative Stress , Serpin E2/genetics , Serpin E2/metabolism , Thrombosis/chemically induced
14.
Am J Transplant ; 13(3): 621-33, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23331923

ABSTRACT

Bronchiolitis obliterans syndrome is characterized by fibrotic obliteration of small airways which severely impairs graft function and survival after lung transplantation. Bronchial epithelial cells from the transplanted lung can undergo epithelial to mesenchymal transition and this can be accentuated by activated macrophages. Macrophages demonstrate significant plasticity and change phenotype in response to their microenvironment. In this study we aimed to identify secretory products from macrophages that might be therapeutic targets for limiting the inflammatory accentuation of epithelial to mesenchymal transition in bronchiolitis obliterans syndrome. TNFα, IL-1ß and IL-8 are elevated in bronchoalveolar lavage from lung transplant patients prior to diagnosis of bronchiolitis obliterans syndrome. Classically activated macrophages secrete more TNFα and IL-1ß than alternatively activated macrophages and dramatically accentuate TGF-ß1-driven epithelial to mesenchymal transition in bronchial epithelial cells isolated from lung transplant patients. Blocking TNFα, but not IL-1ß, inhibits the accentuation of epithelial to mesenchymal transition. In a pilot unblinded therapeutic intervention in five patients with progressive bronchiolitis obliterans syndrome, anti-TNFα treatment improved forced expiratory volume in 1 second and 6-min walk distances in four patients. Our data identify TNFα as a potential new therapeutic target in bronchiolitis obliterans syndrome deserving of a randomized placebo controlled clinical trial.


Subject(s)
Antibodies, Monoclonal/therapeutic use , Bronchiolitis Obliterans/prevention & control , Epithelial-Mesenchymal Transition/drug effects , Graft Rejection/prevention & control , Lung Transplantation , Macrophage Activation/drug effects , Tumor Necrosis Factor-alpha/antagonists & inhibitors , Adolescent , Adult , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Bronchiolitis Obliterans/metabolism , Bronchiolitis Obliterans/pathology , Cytokines/metabolism , Female , Forced Expiratory Volume , Graft Rejection/metabolism , Graft Rejection/pathology , Humans , Inflammation/metabolism , Inflammation/pathology , Inflammation/prevention & control , Infliximab , Male , Middle Aged , Pilot Projects , Prognosis , Transforming Growth Factor beta1/pharmacology , Tumor Necrosis Factor-alpha/metabolism , Young Adult
15.
J Fish Biol ; 81(4): 1175-91, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22957862

ABSTRACT

The timing and levels of black drum Pogonias cromis sound production and egg production were compared in an estuarine canal basin of Cape Coral in south-west Florida. Surface plankton samples were collected hourly from 1800 to 0400 on two consecutive nights while continuous acoustic recordings were made simultaneously at five locations in the canal basin. Five pairs of nights were sampled during a part of the spawning season from late January to early April 2006. Pogonias cromis sound production and egg production occurred on all evenings that samples were collected; however, both the timing and levels of sound production were negatively associated with those of egg production. Egg production estimates ranged from a low of 4·8 eggs m(-3) in February to a high of 2889·2 eggs m(-3) in April. Conversely, maximum nightly sound pressure levels (SPL) ranged from a low of 89·5 dB in April to a high of 131·9 dB (re: 1 µPa) in February. The temporal centre of sound production was relatively stable among all nights sampled but spawning occurred earlier in the day as the season progressed and exhibited a strong, positive association with increased water temperature. The negative relationship between the levels of sound production and egg production was unexpected given the usefulness of sound production as a proxy for reproduction on a seasonal basis and may possibly be explained by differences in the spawning potential of the female population in the study area on nights sampled. Egg mortality rates increased throughout the season and were positively associated with densities of hydrozoans and ctenophores.


Subject(s)
Oviposition/physiology , Perciformes/physiology , Vocalization, Animal/physiology , Animals , Biomass , Clutch Size , Female , Florida , Food Chain , Male , Regression Analysis , Seasons , Temperature , Time Factors
16.
J Fish Biol ; 75(10): 2768-76, 2009 Dec.
Article in English | MEDLINE | ID: mdl-20738522

ABSTRACT

Field measurements of hearing thresholds were obtained from the Atlantic sharpnose shark Rhizoprionodon terraenovae using the auditory evoked potential method (AEP). The fish had most sensitive hearing at 20 Hz, the lowest frequency tested, with decreasing sensitivity at higher frequencies. Hearing thresholds were lower than AEP thresholds previously measured for the nurse shark Ginglymostoma cirratum and yellow stingray Urobatis jamaicensis at frequencies <200 Hz, and similar at 200 Hz and above. Rhizoprionodon terraenovae represents the closest comparison in terms of pelagic lifestyle to the sharks which have been observed in acoustic field attraction experiments. The sound pressure levels that would be equivalent to the particle acceleration thresholds of R. terraenovae were much higher than the sound levels which attracted closely related sharks suggesting a discrepancy between the hearing threshold experiments and the field attraction experiments.


Subject(s)
Auditory Threshold/physiology , Evoked Potentials, Auditory , Hearing/physiology , Sharks/physiology , Animals
17.
Toxicology ; 246(1): 40-4, 2008 Apr 03.
Article in English | MEDLINE | ID: mdl-18194834

ABSTRACT

The liver is susceptible to chronic damage through exposure to a variety of toxins (e.g. alcohol) and viruses (e.g. hepatitis C). Obesity, autoimmune diseases (e.g. autoimmune hepatitis) and a variety of genetic diseases (e.g. Wilson's disease) also lead to chronic liver damage. This damage results in scarring fibrogenesis, structural disruption and functional impairment of the organ. Recent work suggests that there is cross-talk between the PXR and NF-kappaB pathways. This cross-talk may explain the observation that PXR activators inhibit liver fibrosis in in vitro and in vivo animal models of the disease. This reveiw will focus on the two transcription factors and their potential interaction.


Subject(s)
Disease Models, Animal , Hepatocytes/metabolism , Liver Cirrhosis/prevention & control , NF-kappa B/antagonists & inhibitors , Receptors, Steroid/physiology , Animals , Apoptosis/drug effects , Apoptosis/genetics , Apoptosis/physiology , Hepatocytes/drug effects , Humans , Liver Cirrhosis/etiology , NF-kappa B/adverse effects , NF-kappa B/physiology , Pregnane X Receptor , Receptors, Steroid/therapeutic use
18.
J Pharmacol Exp Ther ; 324(3): 902-10, 2008 Mar.
Article in English | MEDLINE | ID: mdl-18077624

ABSTRACT

Liver fibrosis is associated with proliferation of hepatic stellate cells (HSCs) and their transformation into myofibroblastic cells that synthesize scar tissue. Several studies indicate that induction of apoptosis in myofibroblastic cells may prevent fibrogenesis. Gliotoxin (GTX) was found to induce apoptosis of hepatic cells and caused regression of liver fibrosis. However, the use of apoptosis-inducing drugs may be limited due to lack of cell specificity, with a risk of severe adverse effects. In previous studies, we found that mannose-6-phosphate-modified human serum albumin (M6P-HSA) selectively accumulated in liver fibrogenic cells. The aim of this study therefore was to couple GTX to M6P-HSA and test its pharmacological effects in vitro and in rats with liver fibrosis. The conjugate GTX-M6P-HSA bound specifically to HSCs and reduced their viability. Apoptosis was induced in cultures of human hepatic myofibroblasts (hMFs) and in liver slices obtained from rats with liver fibrosis. In vivo treatment with GTX or GTX-M6P-HSA in bile duct ligated rats revealed a significant decrease in alpha-smooth muscle actin mRNA levels and a reduced staining for this HSC marker in fibrotic livers. In addition, although GTX also affected hepatocytes, GTX-M6P-HSA did not significantly affect other liver cells. In conclusion, we developed an HSC-specific compound that induced apoptosis in human hMFs, rat HSCs, and in fibrotic liver slices. In vivo, both GTX and GTX-M6P-HSA attenuated the number of activated HSCs, but GTX also affected hepatocytes. This study shows that cell-selective delivery of the apoptosis-inducing agent GTX is feasible in fibrotic livers.


Subject(s)
Apoptosis/physiology , Drug Delivery Systems/methods , Gliotoxin/administration & dosage , Hepatocytes/cytology , Liver Cirrhosis/pathology , Animals , Apoptosis/drug effects , Cell Survival/drug effects , Cell Survival/physiology , Cells, Cultured , Hepatocytes/drug effects , Hepatocytes/physiology , Humans , Liver Cirrhosis/drug therapy , Male , Rats , Rats, Wistar
19.
Oncogene ; 26(8): 1166-77, 2007 Feb 22.
Article in English | MEDLINE | ID: mdl-16924235

ABSTRACT

Nuclear factor-kappaB (NF-kappaB) is a transcription factor that plays a critical role in the inappropriate survival of various types of malignant cells. Chronic lymphocytic leukaemia (CLL) is the most common B-cell malignancy in the Western world. Although overexpression and regulation of NF-kappaB has been described in CLL, its function remains unclear. Exposure of CLL cells to BAY117082 or Kamebakaurin, potent pharmacological inhibitors of the NF-kappaB pathway, accelerated apoptosis in approximately 70% of cases. Sensitivity to NF-kappaB pathway inhibitors was not related to the prognostic markers VH status, CD38 or Zap70 expression, or to the levels of nuclear NF-kappaB. Normal peripheral B cells were resistant to the apoptosis-inducing effects of these compounds. Cell death induced by the inhibitors was associated with activation of caspase-9 and -3, and loss of mitochondrial membrane polarization, but did not involve changes in the expression of Bcl-2 or Mcl-1. Inhibitors caused an increase in c-jun NH2-terminal kinase activity in CLL, but this did not appear to be important for apoptosis. Microarray analysis identified some potential novel NF-kappaB target genes, including interleukin-16- and the Bcl-2- related survival protein Bcl-w. These results demonstrate that a substantial proportion of CLL are dependent on NF-kappaB for enhanced survival and suggest that inhibition of NF-kappaB may have therapeutic potential.


Subject(s)
Antineoplastic Agents/pharmacology , Apoptosis , Leukemia, Lymphocytic, Chronic, B-Cell/metabolism , NF-kappa B/antagonists & inhibitors , ADP-ribosyl Cyclase 1/analysis , Aged , B-Lymphocytes/drug effects , B-Lymphocytes/metabolism , Biomarkers, Tumor/analysis , Caspase 3/analysis , Caspase 3/metabolism , Caspase 9/analysis , Caspase 9/metabolism , Cell Nucleus/chemistry , Cell Survival/drug effects , Cell Survival/genetics , Diterpenes/pharmacology , Female , Gene Expression Regulation, Neoplastic/drug effects , Humans , Leukemia, Lymphocytic, Chronic, B-Cell/genetics , MAP Kinase Kinase 4/metabolism , Male , Middle Aged , Myeloid Cell Leukemia Sequence 1 Protein , NF-kappa B/analysis , Neoplasm Proteins/metabolism , Nitriles/pharmacology , Prognosis , Proto-Oncogene Proteins c-bcl-2/metabolism , Sulfones/pharmacology , Tumor Cells, Cultured , ZAP-70 Protein-Tyrosine Kinase/analysis
20.
Cell Death Differ ; 14(2): 275-85, 2007 Feb.
Article in English | MEDLINE | ID: mdl-16763620

ABSTRACT

Myofibroblasts are critical cellular elements of wound healing generated at sites of injury by transdifferentiation of resident cells. A paradigm for this process is conversion of hepatic stellate cells (HSC) into hepatic myofibroblasts. Treatment of HSC with DNA methylation inhibitor 5-aza-2'-deoxycytidine (5-azadC) blocked transdifferentiation. 5-azadC also prevented loss of IkappaBalpha and PPARgamma expression that occurs during transdifferentiation to allow acquisition of proinflammatory and profibrogenic characteristics. ChIP analysis revealed IkappaBalpha promoter is associated with transcriptionally repressed chromatin that converts to an active state with 5-azadC treatment. The methyl-CpG-binding protein MeCP2 which promotes repressed chromatin structure is selectively detected in myofibroblasts of diseased liver. siRNA knockdown of MeCP2 elevated IkappaBalpha promoter activity, mRNA and protein expression in myofibroblasts. MeCP2 interacts with IkappaBalpha promoter via a methyl-CpG-dependent mechanism and recruitment into a CBF1 corepression complex. We conclude that MeCP2 and DNA methylation exert epigenetic control over hepatic wound healing and fibrogenesis.


Subject(s)
Cell Differentiation , DNA Methylation , Fibroblasts/cytology , Liver Cirrhosis/pathology , Methyl-CpG-Binding Protein 2/metabolism , Wound Healing , Animals , Azacitidine/analogs & derivatives , Azacitidine/pharmacology , Cell Differentiation/drug effects , CpG Islands/drug effects , DNA Methylation/drug effects , Decitabine , Epigenesis, Genetic/drug effects , Fibroblasts/drug effects , Hepatocytes/cytology , Hepatocytes/drug effects , Humans , I-kappa B Proteins/genetics , Liver/cytology , Liver/drug effects , Liver/pathology , Liver Cirrhosis/chemically induced , Male , Methyl-CpG-Binding Protein 2/genetics , Mice , Models, Genetic , NF-KappaB Inhibitor alpha , Promoter Regions, Genetic/drug effects , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats , Rats, Sprague-Dawley , Repressor Proteins/metabolism , Transcription, Genetic/drug effects , Wound Healing/drug effects
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