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1.
Int J Mol Sci ; 25(11)2024 Jun 06.
Article in English | MEDLINE | ID: mdl-38892462

ABSTRACT

For patients with hereditary breast and ovarian cancer, the probability of carrying two pathogenic variants (PVs) in dominant cancer-predisposing genes is rare. Using targeted next-generation sequencing (NGS), we investigated a 49-year-old Caucasian woman who developed a highly aggressive breast tumor. Our analyses identified an intragenic germline heterozygous duplication in BRCA1 with an additional likely PV in the TP53 gene. The BRCA1 variant was confirmed by multiplex ligation probe amplification (MLPA), and genomic breakpoints were characterized at the nucleotide level (c.135-2578_442-1104dup). mRNA extracted from lymphocytes was amplified by RT-PCR and then Sanger sequenced, revealing a tandem duplication r.135_441dup; p.(Gln148Ilefs*20). This duplication results in the synthesis of a truncated and, most likely, nonfunctional protein. Following functional studies, the TP53 exon 5 c.472C > T; p.(Arg158Cys) missense variant was classified as likely pathogenic by the Li-Fraumeni Syndrome (LFS) working group. This type of unexpected association will be increasingly identified in the future, with the switch from targeted BRCA sequencing to hereditary breast and ovarian cancer (HBOC) panel sequencing, raising the question of how these patients should be managed. It is therefore important to record and investigate these rare double-heterozygous genotypes.


Subject(s)
BRCA1 Protein , Triple Negative Breast Neoplasms , Tumor Suppressor Protein p53 , Humans , Female , Middle Aged , Tumor Suppressor Protein p53/genetics , BRCA1 Protein/genetics , Triple Negative Breast Neoplasms/genetics , Triple Negative Breast Neoplasms/pathology , Gene Duplication , Genetic Predisposition to Disease , Germ-Line Mutation , High-Throughput Nucleotide Sequencing
2.
J Zoo Wildl Med ; 52(1): 192-199, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33827176

ABSTRACT

Enterotoxemia is an important issue in various zoological taxa. In this study, serologic responses over a 1-yr period after vaccination with a multivalent clostridial vaccine were evaluated in 10 adult springboks (Antidorcas marsupialis), 12 impalas (Aepyceros melampus), seven alpacas (Vicugna pacos), and five red-necked wallabies (Macropus rufogriseus). Antibody production to the Clostridium perfringens type D epsilon toxin component of the vaccine was measured using an indirect enzyme-linked immunosorbent assay and determined as the percentage of inhibition (% inhib). Initial % inhib was (0.01-18.9)%. All animals received initial vaccination with a booster vaccine 4 weeks apart. Serum samples were collected at T0 (nonvaccinated), 15, 30, 60, 180, and 360 days postvaccination (dpv) for analysis. The vaccine induced a high antibody response that peaked at 15, 30, and 60 dpv in springboks, 30 and 60 dpv in impalas (P < 0.01), and 60 dpv in alpacas and wallabies (P < 0.01). The booster vaccine was followed by a high antibody response, which slowly decreased with time. The antibody response was significantly higher at 360 dpv than at T0 in wallabies and alpacas (P < 0.01). In impalas and springboks, it appeared that a booster every 6 mo might be required to maintain an antibody response above baseline (P < 0.01). Because no challenge studies were performed, it is unknown whether the measured humoral immune responses would have been protective. Further research is warranted to investigate protective effects of antibodies to inoculation challenge in nondomestic species.


Subject(s)
Antelopes/blood , Bacterial Toxins/immunology , Bacterial Vaccines/immunology , Camelids, New World/blood , Clostridium perfringens/immunology , Macropodidae/blood , Animals , Animals, Zoo , Antelopes/immunology , Antibodies, Bacterial/blood , Camelids, New World/immunology , Clostridium Infections/prevention & control , Clostridium Infections/veterinary , Female , Macropodidae/immunology , Male , Time Factors
3.
Dis Aquat Organ ; 142: 119-124, 2020 Dec 03.
Article in English | MEDLINE | ID: mdl-33269723

ABSTRACT

An outbreak of salmonellosis occurred in a group of 7 long-nosed fur seals Arctocephalus forsteri undergoing rehabilitation after being found injured and malnourished on beaches along the northern New South Wales and southern Queensland coasts of Australia. Three of the 7 individuals developed clinical disease and died within 3 d. Clinical signs included profuse diarrhea, vomiting, depression, and lethargy. Salmonella enterica subsp. enterica serovar Kentucky (S. Kentucky) was cultured from 2 of the 3 deceased animals. The other 4 animals showed similar signs and recovered following treatment. S. Kentucky (antigenic formula 8,20:i:z6) was isolated from the survivors and tissues recovered from post-mortem samples of deceased animals. The bacterium was susceptible to cephalothin and sulfamethoxazole/trimethoprim and resistant to amoxicillin-clavulanate, ampicillin/amoxicillin, tetracycline, and enrofloxacin. This organism has the potential to cause disease in aquatic wildlife, as well as posing a zoonotic threat to people who utilise the aquatic environment.


Subject(s)
Fur Seals , Animals , Anti-Bacterial Agents/pharmacology , Australia , Disease Outbreaks/veterinary , Drug Resistance, Multiple, Bacterial , Kentucky/epidemiology , Microbial Sensitivity Tests/veterinary , New South Wales , Queensland , Salmonella
4.
Ann Clin Transl Neurol ; 6(9): 1681-1695, 2019 09.
Article in English | MEDLINE | ID: mdl-31400065

ABSTRACT

OBJECTIVES: Blood biomarkers for cerebral tissue ischemia are lacking. The goal was to identify a blood transcriptomic signature jointly identified in the ischemic brain. METHODS: A nonhuman primate model with middle cerebral artery (MCA) territory infarction was used to study gene expression by microarray during acute ischemic cerebral stroke in the brain and the blood. Brain samples were collected in the infarcted and contralateral non-infarcted cortex as well as blood samples before and after occlusion. Gene expression was compared between the two brain locations to find differentially expressed genes. The expressions of these genes were then compared in the blood pre- and post-occlusion. RESULTS: Hierarchical clustering of brain expression data revealed strong independent clustering of ischemic and nonischemic brain samples. The top five enriched, up-regulated gene sets in the brain were TNF α signaling, apoptosis, P53 pathway, hypoxia, and UV response up. A comparison of differentially expressed genes in the brain and blood revealed a significant overlap of gene expression patterns. Stringent analysis of blood expression data from pre- and post-occlusion samples in each monkey identified nine genes highly differentially expressed in both the brain and the blood. Many of these up-regulated genes belong to pathways involved in cell death and DNA damage repair. INTERPRETATION: Common gene expression profile can be identified in the brain and blood and clearly differentiates ischemic from nonischemic conditions. Therefore, specific blood transcriptomic signature may represent a surrogate for brain ischemic gene expression.


Subject(s)
Brain Ischemia/diagnosis , Infarction, Middle Cerebral Artery/diagnosis , Animals , Biomarkers/blood , Brain/diagnostic imaging , Brain Ischemia/blood , Brain Ischemia/diagnostic imaging , Brain Ischemia/genetics , Disease Models, Animal , Gene Expression Profiling , Infarction, Middle Cerebral Artery/blood , Infarction, Middle Cerebral Artery/diagnostic imaging , Infarction, Middle Cerebral Artery/genetics , Macaca mulatta , Magnetic Resonance Imaging , Male , Transcriptome/physiology
5.
J Wildl Dis ; 55(1): 258-261, 2019 01.
Article in English | MEDLINE | ID: mdl-30235083

ABSTRACT

An adult male pygmy sperm whale ( Kogia breviceps) stranded alive at a beach in Florida, US, in 2016. Main postmortem examination findings included bilateral multifocal variably sized renal cysts, focal renal cystadenoma, and mild dilation of the renal pelvises. The role of these renal lesions in the stranding of this whale is unknown.


Subject(s)
Cystadenoma/veterinary , Kidney Neoplasms/veterinary , Polycystic Kidney Diseases/veterinary , Whales , Animals , Cystadenoma/pathology , Kidney Neoplasms/pathology , Male , Polycystic Kidney Diseases/pathology
6.
Vet Immunol Immunopathol ; 203: 57-59, 2018 Sep.
Article in English | MEDLINE | ID: mdl-30243374

ABSTRACT

Veterinary medical examinations, including both physical examination and diagnostic tests, are important to monitor the health of both managed-care and wild marine mammals. However, limited species-specific reagents and assays are available that may contribute to a broader medical examination. This project evaluated if commercially available human and porcine antibodies and reagents would cross-react with manatee (Trichechus manatus) cytokines as the first step to validate a new diagnostic tool for manatees. Overall, as a result of limited cross-reactivity, human and porcine commercial reagents did not allow for the quantification of manatee cytokines. At this point, caution must be exercised when using human or porcine immunoassay reagents to quantify manatee cytokines if the reagents have not been fully validated. Future efforts will continue to explore and test the cross-reactivity of reagents to measure manatee cytokines as new species-specific and commercial reagents become available.


Subject(s)
Cytokines/blood , Indicators and Reagents/therapeutic use , Trichechus manatus/immunology , Animals , Cross Reactions/immunology , Cytokines/immunology , Enzyme-Linked Immunosorbent Assay/veterinary , Humans , Interleukins/blood , Interleukins/immunology , Leukocytes, Mononuclear/immunology , Polymerase Chain Reaction/veterinary , Swine , Trichechus manatus/blood
7.
J Fish Dis ; 41(9): 1453-1458, 2018 Sep.
Article in English | MEDLINE | ID: mdl-29882594

ABSTRACT

This report describes a case of systemic bacterial infection caused by Edwardsiella tarda in a Western African lungfish (Protopterus annectens) exposed to poor environmental and husbandry conditions. The fish presented with a large, external ulcerative lesion and died 2 weeks after developing anorexia. Histological evaluation revealed multifocal areas of necrosis and heterophilic and histiocytic inflammation throughout multiple tissues. Gram stain identified small numbers of intra- and extracellular monomorphic Gram-negative 1 to 2 µm rod-shaped bacilli. Cytology of lung granuloma, kidney and testes imprints identified heterophilic inflammation with phagocytosis of small monomorphic bacilli and some heterophils exhibiting cytoplasmic projections indicative of heterophil extracellular traps (HETs). Initial phenotypic analysis of isolates from coelomic fluid cultures identified E. tarda. Subsequent molecular analysis of spleen, liver and intestine DNA using an E. tarda-specific endpoint PCR assay targeting the bacterial fimbrial subunit yielded a 115 bp band. Sequencing and BLASTN search revealed the sequence was identical (76/76) to E. tarda strain FL95-01 (GenBank acc. CP011359) and displayed 93% sequence identity (66/71) to Edwardsiella hoshinae strain ATCC 35051 (GenBank acc. CP011359). This is the first report of systemic edwardsiellosis in a lungfish with concurrent cytologically identified structures suggestive of HETs.


Subject(s)
Edwardsiella tarda/isolation & purification , Enterobacteriaceae Infections/veterinary , Fish Diseases/blood , Fishes/microbiology , Animals , Anorexia , Cytological Techniques , DNA, Bacterial/genetics , Edwardsiella tarda/genetics , Edwardsiella tarda/immunology , Edwardsiella tarda/physiology , Enterobacteriaceae Infections/blood , Enterobacteriaceae Infections/microbiology , Extracellular Traps/immunology , Fish Diseases/microbiology , Granulocytes/ultrastructure , Kidney/cytology , Kidney/microbiology , Kidney/pathology , Lung/cytology , Lung/microbiology , Lung/pathology , Lung/ultrastructure , Male , Phylogeny , Polymerase Chain Reaction , Sepsis/microbiology , Testis/cytology , Testis/microbiology , Testis/pathology
8.
J Cereb Blood Flow Metab ; 38(6): 1070-1084, 2018 06.
Article in English | MEDLINE | ID: mdl-28569655

ABSTRACT

Stroke is a devastating disorder that significantly contributes to death, disability and healthcare costs. In ischemic stroke, the only current acute therapy is recanalization, but the narrow therapeutic window less than 6 h limits its application. The current challenge is to prevent late cell death, with concomitant therapy targeting the ischemic cascade to widen the therapeutic window. Among potential neuroprotective drugs, cyclin-dependent kinase inhibitors such as (S)-roscovitine are of particular relevance. We previously showed that (S)-roscovitine crossed the blood-brain barrier and was neuroprotective in a dose-dependent manner in two models of middle cerebral artery occlusion (MCAo). According to the Stroke Therapy Academic Industry Roundtable guidelines, the pharmacokinetics of (S)-roscovitine and the optimal mode of delivery and therapeutic dose in rats were investigated. Combination of intravenous (IV) and continuous sub-cutaneous (SC) infusion led to early and sustained delivery of (S)-roscovitine. Furthermore, in a randomized blind study on a transient MCAo rat model, we showed that this mode of delivery reduced both infarct and edema volume and was beneficial to neurological outcome. Within the framework of preclinical studies for stroke therapy development, we here provide data to improve translation of pre-clinical studies into successful clinical human trials.


Subject(s)
Brain Edema , Brain Ischemia , Neuroprotective Agents , Recovery of Function/drug effects , Roscovitine , Animals , Brain Edema/drug therapy , Brain Edema/metabolism , Brain Edema/pathology , Brain Edema/physiopathology , Brain Ischemia/drug therapy , Brain Ischemia/metabolism , Brain Ischemia/pathology , Brain Ischemia/physiopathology , Male , Neuroprotective Agents/pharmacokinetics , Neuroprotective Agents/pharmacology , Random Allocation , Rats , Rats, Sprague-Dawley , Roscovitine/pharmacokinetics , Roscovitine/pharmacology
9.
J Toxicol Environ Health A ; 80(10-12): 556-561, 2017.
Article in English | MEDLINE | ID: mdl-28841368

ABSTRACT

Threatened loggerhead sea turtles (Caretta caretta) face numerous environmental challenges, including exposure to anthropogenic chemicals such as polychlorinated biphenyls (PCBs). Despite being banned by the USA in the 1970s, PCBs persist in the environment and produce immunotoxic effects in a wide range of marine vertebrate species. This is of particular concern, as the modulation of the immune system may enhance the susceptibility to a variety of pathogens. Blood samples were collected from 19 immature, captive-reared loggerhead sea turtles. Functional immune assays phagocytosis and natural killer (NK) cell activity were used to quantify the direct effects of PCB congeners 105, 138, and 169 on innate immune functions upon in vitro exposure of sea turtle cells to increasing concentrations (control (0), 0.5, 1, 2.5, 5, 10, 15, or 20 ppm) of each PCB. PCB 105 significantly elevated eosinophil phagocytosis at 10 and 15 ppm and PCB 138 at 15 ppm compared to unexposed (0 ppm). The effects of PCB 169 on phagocytosis were not evaluated. PCB 138 and 105 significantly decreased NK cell activity at 15 and 20 ppm, compared to unexposed (0 ppm) controls. PCB 169 did not markedly modulate NK activity. This constitutes the first study to investigate the in vitro effects of these three PCBs on sea turtle innate immune functions. These results add to our understanding of PCB-induced immunotoxicity in sea turtles and may provide a framework for establishing the relationships between chemical levels and turtle immunity.


Subject(s)
Environmental Exposure , Killer Cells, Natural/drug effects , Phagocytosis/drug effects , Polychlorinated Biphenyls/toxicity , Turtles/physiology , Water Pollutants, Chemical/toxicity , Animals
10.
Vet Clin Pathol ; 46(4): 625-628, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28815678

ABSTRACT

An 11-year-old intact male Green iguana (Iguana iguana) was referred for treatment of a probable iridophoroma based on previous cytopathology. A periocular mass was present near the right medial canthus. Computed tomography did not show any sign of metastasis. Clinicopathologic abnormalities included lymphopenia and hyperproteinemia. Cytologic and histologic evaluations of the mass were consistent with iridophoroma. Complete surgical excision of the mass was not possible without removal of the orbit due to local tissue involvement. Recovery and suture removal were unremarkable. Adjunctive radiation therapy was recommended, but not performed. A year later, the surgical site had healed well. To our knowledge, this is the first reported chromatophoroma cytopathology in a Green iguana. Chromatophoromas should be included in the differential diagnoses of pigmented skin tumors in reptiles. Early surgical excision is useful to limit local tissue destruction and metastatic potential.


Subject(s)
Eye Neoplasms/veterinary , Iguanas , Skin Neoplasms/veterinary , Animals , Chromatophores , Eye Neoplasms/pathology , Male , Skin Neoplasms/pathology
12.
Proc Natl Acad Sci U S A ; 110(43): 17362-7, 2013 Oct 22.
Article in English | MEDLINE | ID: mdl-24101515

ABSTRACT

PC7 belongs to the proprotein convertase family, whose members are implicated in the cleavage of secretory precursors. The in vivo function of PC7 is unknown. Herein, we find that the precursor proBDNF is processed into mature BDNF in COS-1 cells coexpressing proBDNF with either PC7 or Furin. Conversely, the processing of proBDNF into BDNF is markedly reduced in the absence of either Furin or PC7 in mouse primary hepatocytes. In vivo we observe that BDNF and PC7 mRNAs are colocalized in mouse hippocampus and amygdala and that mature BDNF protein levels are reduced in these brain areas in PC7 KO mice but not in the hippocampus of PC1/3 KO mice. Various behavioral tests reveal that in PC7 KO mice spatial memory is intact and plasticity of responding is mildly abnormal. Episodic and emotional memories are severely impaired, but both are rescued with the tyrosine receptor kinase B agonist 7,8-dihydroxyflavone. Altogether, these results support an in vivo role for PC7 in the regulation of certain types of cognitive performance, in part via proBDNF processing. Because polymorphic variants of human PC7 are being characterized, it will be important in future studies to determine their effects on additional physiological and behavioral processes.


Subject(s)
Brain-Derived Neurotrophic Factor/metabolism , Maze Learning/physiology , Memory/physiology , Subtilisins/metabolism , Amygdala/metabolism , Animals , Blotting, Western , COS Cells , Cells, Cultured , Chlorocebus aethiops , Female , Flavanones/pharmacology , Gene Expression , HEK293 Cells , Hepatocytes/cytology , Hepatocytes/metabolism , Hippocampus/metabolism , Humans , In Situ Hybridization , Male , Maze Learning/drug effects , Memory/drug effects , Mice , Mice, Knockout , Protein Precursors/genetics , Protein Precursors/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Subtilisins/genetics
13.
Vet Immunol Immunopathol ; 156(1-2): 43-53, 2013 Nov 15.
Article in English | MEDLINE | ID: mdl-24094689

ABSTRACT

Sea turtles face numerous environmental challenges, such as exposure to chemical pollution and biotoxins, which may contribute to immune system impairment, resulting in increased disease susceptibility. Therefore, a more thorough assessment of the host's immune response and its susceptibility is needed for these threatened and endangered animals. In this study, the innate and acquired immune functions of sixty-five clinically healthy, immature, captive loggerhead sea turtles (Caretta caretta) were assayed using non-lethal blood sample collection. Functional immune assays were developed and/or optimized for this species, including mitogen-induced lymphocyte proliferation, natural killer (NK) cell activity, phagocytosis, and respiratory burst. Peripheral blood mononuclear cells (PBMC) and phagocytes were isolated by density gradient centrifugation on Ficoll-Paque and discontinuous Percoll gradients, respectively. The T lymphocyte mitogens ConA significantly induced lymphocyte proliferation at 1 and 2 µg/mL while PHA significantly induced lymphocyte proliferation at 5 and 10 µg/mL. The B lymphocyte mitogen LPS significantly induced proliferation at 1 µg/mL. Monocytes demonstrated higher phagocytic activity than eosinophils. In addition, monocytes exhibited respiratory burst. Natural killer cell activity was higher against YAC-1 than K-562 target cells. These optimized assays may help to evaluate the integrity of loggerhead sea turtle's immune system upon exposure to environmental contaminants, as well as part of a comprehensive health assessment and monitoring program.


Subject(s)
Turtles/immunology , Adaptive Immunity , Animals , Flow Cytometry , Immunity, Innate , Leukocytes/immunology , Lymphocyte Activation , Phagocytosis
14.
J Zoo Wildl Med ; 44(4): 859-74, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24450044

ABSTRACT

Abstract: Blood samples of 85 immature, apparently healthy, captive-reared loggerhead sea turtles (Caretta caretta) were analyzed for 13 hematologic variables and total solids of 5 age groups (8, 20, 32, 44, and 56 mo old) and for 20 plasma biochemical analytes of 4 age groups (20 to 56 mo old). Each individual turtle was sampled under similar conditions during a blood collection period of 3 days. Hematologic analytes included packed cell volume, white blood cell (WBC) counts, WBC estimates, and leukocyte differentials. Biochemical analysis included albumin, alanine aminotransferase, alkaline phosphatase, amylase, aspartate aminotransferase, blood urea nitrogen, calcium, chloride, cholesterol, creatine kinase, creatinine, gamma glutamyltransferase, globulins, glucose, phosphorous, potassium, sodium, total bilirubin, total protein, total solids, and uric acid. In due consideration of small sample size in all five age groups, the results of hematologic and biochemical analysis were used to determine ranges for these analytes and to compare values among consecutive age groups. Several significant differences in some hematologic and biochemical variables were identified and need to be considered in the interpretation of blood work of immature, growing sea turtles in human care.


Subject(s)
Blood Cell Count/veterinary , Blood Chemical Analysis/veterinary , Hematologic Tests/veterinary , Turtles/blood , Animals , Reference Values
15.
J Vis Exp ; (69)2012 Nov 06.
Article in English | MEDLINE | ID: mdl-23168377

ABSTRACT

Stroke is the third cause of mortality and the leading cause of disability in the World. Ischemic stroke accounts for approximately 80% of all strokes. However, the thrombolytic tissue plasminogen activator (tPA) is the only treatment of acute ischemic stroke that exists. This led researchers to develop several ischemic stroke models in a variety of species. Two major types of rodent models have been developed: models of global cerebral ischemia or focal cerebral ischemia. To mimic ischemic stroke in patients, in whom approximately 80% thrombotic or embolic strokes occur in the territory of the middle cerebral artery (MCA), the intraluminal middle cerebral artery occlusion (MCAO) model is quite relevant for stroke studies. This model was first developed in rats by Koizumi et al. in 1986 (1). Because of the ease of genetic manipulation in mice, these models have also been developed in this species (2-3). Herein, we present the transient MCA occlusion procedure in C57/Bl6 mice. Previous studies have reported that physical properties of the occluder such as tip diameter, length, shape, and flexibility are critical for the reproducibility of the infarct volume (4). Herein, a commercial silicon coated monofilaments (Doccol Corporation) have been used. Another great advantage is that this monofilament reduces the risk to induce subarachnoid hemorrhages. Using the Zeiss stereo-microscope Stemi 2000, the silicon coated monofilament was introduced into the internal carotid artery (ICA) via a cut in the external carotid artery (ECA) until the monofilament occludes the base of the MCA. Blood flow was restored 1 hour later by removal of the monofilament to mimic the restoration of blood flow after lysis of a thromboembolic clot in humans. The extent of cerebral infarct may be evaluated first by a neurologic score and by the measurement of the infarct volume. Ischemic mice were thus analyzed for their neurologic score at different post-reperfusion times. To evaluate the infarct volume, staining with 2,3,5-triphenyltetrazolium chloride (TTC) was usually performed. Herein, we used cresyl violet staining since it offers the opportunity to test many critical markers by immunohistochemistry. In this video, we report the MCAO procedure; neurological scores and the evaluation of the infarct volume by cresyl violet staining.


Subject(s)
Brain Infarction/pathology , Disease Models, Animal , Infarction, Middle Cerebral Artery/pathology , Oxazines/chemistry , Staining and Labeling/methods , Animals , Benzoxazines , Brain Chemistry , Immunohistochemistry , Male , Mice , Mice, Inbred C57BL , Middle Cerebral Artery/surgery
16.
Mol Pharmacol ; 82(5): 948-57, 2012 Nov.
Article in English | MEDLINE | ID: mdl-22909796

ABSTRACT

Reactive astrogliosis is beneficial in many aspects; however, it is also detrimental in some pathological states such as the development of lethal brain tumors. It is therefore crucial to understand the mechanisms regulating astrocyte proliferation. Tumor necrosis factor-like weak inducer of apoptosis (TWEAK), a member of the tumor necrosis factor family, was shown to stimulate astrocyte proliferation in vitro. Herein, we further characterize the mitogenic potential of TWEAK on central nervous system cells. Among these cells, astrocytes express the highest level of TWEAK and Fn14 transcripts, suggesting that they are particularly sensitive to TWEAK stimulation. Using in vitro model systems, we found that TWEAK was as potent as epidermal growth factor (EGF) (a prototypical astrocyte mitogen) in mediating astrocyte proliferation. However, its mitogenic activity was delayed compared with that of EGF, suggesting distinct mechanisms of action. Using cell signaling pathway inhibitors, neutralizing antibodies, and protein assays, we further show that the mitogenic activity of TWEAK on primary astrocytes requires stimulation of the transforming growth factor-α (TGF-α) and of the epidermal growth factor receptor (EGFR) signaling pathway through extracellular signal-regulated kinase and p38 mitogen-activated protein kinase activation. In aggregates, our data demonstrate that TWEAK acts as a potent astrocyte mitogen through the induction of a TGF-α/EGFR signaling pathway. We anticipate that description of such a mechanism may allow novel approaches to human pathologies associated with astrocyte proliferation.


Subject(s)
Apoptosis Regulatory Proteins/metabolism , Astrocytes/cytology , ErbB Receptors/physiology , Membrane Proteins/metabolism , Transforming Growth Factor alpha/physiology , Tumor Necrosis Factors/metabolism , Animals , Apoptosis Regulatory Proteins/pharmacology , Astrocytes/metabolism , Cell Proliferation , Cytokine TWEAK , Embryo, Mammalian , Enzyme Activation , Epidermal Growth Factor/pharmacology , ErbB Receptors/antagonists & inhibitors , Membrane Proteins/pharmacology , Microglia/cytology , Microglia/drug effects , Microglia/metabolism , Mitogen-Activated Protein Kinase 1/metabolism , Mitogen-Activated Protein Kinase 3/metabolism , Neurons/cytology , Neurons/drug effects , Neurons/metabolism , Primary Cell Culture , Rats , Rats, Wistar , Receptors, Tumor Necrosis Factor/metabolism , Recombinant Proteins/pharmacology , Signal Transduction , TWEAK Receptor , Tumor Necrosis Factors/pharmacology , p38 Mitogen-Activated Protein Kinases/metabolism
17.
J Neurochem ; 122(5): 1032-46, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22708926

ABSTRACT

1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) intoxication of mice is a standard model of Parkinson's disease (PD). However, it does not reproduce functionally PD. Given the occurrence of PD during aging, symptoms might only be detected in MPTP-intoxicated mice after aging. To address this, mice injected with MPTP at 2.5 months were followed up to a maximum age of 21 months. There was no loss of dopamine cells with aging in control mice; moreover, the initial post-MPTP intoxication decrease in dopamine cell was no longer significant at 21 months. With aging, striatal dopamine level remained constant, but concentrations of the dopamine metabolites dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) were markedly reduced in both groups. There was also a late impairment of fine motor skills. After MPTP intoxication, hyperactivity was immediately detected and it became greater than in control mice from 14 months of age; fine motor skills were also more impaired; both these symptoms were correlated with striatal dopamine, DOPAC and HVA concentrations. In bothgroups, neither motor symptoms nor dopamine changes worsened with age. These findings do not support the notion that PD develops with age in mice after MPTP intoxication and that the motor deficits seen are because of an aging process.


Subject(s)
Aging , Behavior, Animal/physiology , Brain/pathology , Dopamine/metabolism , MPTP Poisoning , Motor Activity/physiology , 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine/pharmacology , 3,4-Dihydroxyphenylacetic Acid/metabolism , Age Factors , Aging/drug effects , Animals , Behavior, Animal/drug effects , Brain/drug effects , Brain/metabolism , Disease Models, Animal , Gene Expression Regulation/drug effects , Homovanillic Acid/metabolism , MPTP Poisoning/chemically induced , MPTP Poisoning/pathology , MPTP Poisoning/physiopathology , Male , Mice , Mice, Inbred C57BL , Motor Activity/drug effects , Neurotoxins/pharmacology , Rotarod Performance Test , Statistics as Topic , Tyrosine 3-Monooxygenase/metabolism
18.
J Lipid Res ; 52(7): 1383-91, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21518694

ABSTRACT

Proprotein convertase subtilisin/kexin type 9 (PCSK9) plays a major role in cholesterol homeostasis through enhanced degradation of the LDL receptor (LDLR) in liver. As novel inhibitors/silencers of PCSK9 are now being tested in clinical trials to treat hypercholesterolemia, it is crucial to define the physiological consequences of the lack of PCSK9 in various organs. LDLR regulation by PCSK9 has not been extensively described during mouse brain development and injury. Herein, we show that PCSK9 and LDLR are co-expressed in mouse brain during development and at adulthood. Although the protein levels of LDLR and apolipoprotein E (apoE) in the adult brain of Pcsk9(-/-) mice are similar to those of wild-type (WT) mice, LDLR levels increased and were accompanied by a reduction of apoE levels during development. This suggests that the upregulation of LDLR protein levels in Pcsk9(-/-) mice enhances apoE degradation. Upon ischemic stroke, PCSK9 was expressed in the dentate gyrus between 24 h and 72 h following brain reperfusion. Although mouse behavior and lesion volume were similar, LDLR protein levels dropped ∼2-fold less in the Pcsk9(-/-)-lesioned hippocampus, without affecting apoE levels and neurogenesis. Thus, PCSK9 downregulates LDLR levels during brain development and following transient ischemic stroke in adult mice.


Subject(s)
Brain Ischemia/metabolism , Brain/growth & development , Brain/metabolism , Receptors, LDL/metabolism , Serine Endopeptidases/metabolism , Animals , Apolipoproteins E/metabolism , Brain Ischemia/complications , Brain Ischemia/genetics , Cerebellum/metabolism , Dentate Gyrus/metabolism , Mice , Proprotein Convertase 9 , Proprotein Convertases , RNA, Messenger/genetics , RNA, Messenger/metabolism , Serine Endopeptidases/deficiency , Serine Endopeptidases/genetics , Stroke/complications , Telencephalon/metabolism , Time Factors , Up-Regulation
19.
EMBO Mol Med ; 3(3): 153-66, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21328542

ABSTRACT

Luminal B breast cancers represent a fraction of oestrogen receptor (ER)-positive tumours associated with poor recurrence-free and disease-specific survival in all adjuvant systemic treatment categories including hormone therapy alone. Identification of specific signalling pathways driving luminal B biology is paramount to improve treatment. We have studied 100 luminal breast tumours by combined analysis of genome copy number aberrations and gene expression. We show that amplification of the ZNF703 gene, located in chromosomal region 8p12, preferentially occurs in luminal B tumours. We explored the functional role of ZNF703 in luminal B tumours by overexpressing ZNF703 in the MCF7 luminal cell line. Using mass spectrometry, we identified ZNF703 as a co-factor of a nuclear complex comprising DCAF7, PHB2 and NCOR2. ZNF703 expression results in the activation of stem cell-related gene expression leading to an increase in cancer stem cells. Moreover, we show that ZNF703 is implicated in the regulation of ER and E2F1 transcription factor. These findings point out the prominent role of ZNF703 in transcription modulation, stem cell regulation and luminal B oncogenesis.


Subject(s)
Breast Neoplasms/genetics , Carrier Proteins/genetics , Gene Amplification , Cell Line , E2F1 Transcription Factor/metabolism , Female , Gene Expression , Humans , Mass Spectrometry , Prohibitins , Receptors, Estrogen/metabolism
20.
J Biol Chem ; 286(11): 9185-95, 2011 Mar 18.
Article in English | MEDLINE | ID: mdl-21209099

ABSTRACT

Although the processing profile of the membrane-bound epidermal growth factor precursor (pro-EGF) is tissue-specific, it has not been investigated at the cellular level nor have the cognate proteinases been defined. Among the proprotein convertases (PCs), only the membrane-bound PC7, the most ancient and conserved basic amino acid-specific PC family member, induces the processing of pro-EGF into an ∼115-kDa transmembrane form (EGF-115) at an unusual VHPR(290)↓A motif. Because site-directed mutagenesis revealed that Arg(290) is not critical, the generation of EGF-115 by PC7 is likely indirect. This was confirmed by testing a wide range of protease inhibitors, which revealed that the production of EGF-115 is most probably achieved via the activation by PC7 of a latent serine and/or cysteine protease(s). EGF-115 is more abundant at the cell surface than pro-EGF and is associated with a stronger EGF receptor (EGFR) activation, as evidenced by higher levels of phosphorylated ERK1/2. This suggests that the generation of EGF-115 represents a regulatory mechanism of juxtacrine EGFR activation. Thus, PC7 is distinct from the other PCs in its ability to enhance the activation of the cell surface EGFR.


Subject(s)
Epidermal Growth Factor/metabolism , ErbB Receptors/metabolism , Protein Precursors/metabolism , Protein Processing, Post-Translational/physiology , Subtilisins/metabolism , Animals , COS Cells , Chlorocebus aethiops , Epidermal Growth Factor/genetics , ErbB Receptors/genetics , HEK293 Cells , Humans , Mice , Mitogen-Activated Protein Kinase 1/genetics , Mitogen-Activated Protein Kinase 1/metabolism , Mitogen-Activated Protein Kinase 3/genetics , Mitogen-Activated Protein Kinase 3/metabolism , Protease Inhibitors/pharmacology , Protein Precursors/genetics , Protein Processing, Post-Translational/drug effects , Subtilisins/antagonists & inhibitors , Subtilisins/genetics
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