Chronic exposure to the parasite Enteromyxum leei (Myxozoa: Myxosporea) modulates the immune response and the expression of growth, redox and immune relevant genes in gilthead sea bream, Sparus aurata L.
ABSTRACT The myxosporean parasite Enteromyxum leei invades the intestine of gilthead sea bream producing a slow-progressing disease, which may end in the death of fish. The present work aimed to better know the host immune response and the underlying molecular mechanisms, which may help to understand why some individuals seem to be refractory to the disease. Three main aspects involved in fish health and welfare (immune, growth and redox status) were studied in fish exposed to E. leei-contaminated effluent, in comparison with control animals (not exposed to the disease). After chronic exposure (113days), prevalence of infection was 67.8%. Among exposed fish, parasitized and non-parasitized fish exhibited clear differences in some of the measured innate immune factors (respiratory burst, serum peroxidases, lysozyme and complement), and in the expression of immune, antioxidant and GH-related genes. The respiratory burst of parasitized fish was significantly higher, and serum peroxidases and lysozyme were significantly decreased both in parasitized and non-parasitized fish. The gene expression of GHR-I, GHR-II, IGF-I and IGF-II was measured in head kidney (HK) samples, and that of interleukin (IL)-1beta, tumour necrosis factor (TNF)-alpha, alpha-2M, GR, GPx-1 and GRP-75 was measured in intestine and HK samples, by rtqPCR. Parasitized fish exhibited a down-regulation of IL-1beta, TNF-alpha and GPx-1 in the intestine, and GHR-I and IGF-I were also down regulated in HK. alpha-2M and GRP-75 were over-expressed in the intestine of parasitized animals. Non-parasitized fish had increased transcripts of GHR-I and IGF-I with respect to control animals, which could furnish their immunocytes with an advantage to combat the parasite. The expression of GHR-II and IGF-II was not altered by the parasite challenge.
- SourceAvailable from: CHAN P[Show abstract] [Hide abstract]
ABSTRACT: Glutamine, the most abundant amino acid in the human body, plays several important roles in the intestine. Previous studies showed that glutamine may affect protein expression by regulating ubiquitin-proteasome system. We thus aimed to evaluate the effects of gl utamine on ubiquitinated proteins in human duodenal mucosa. Five healthy male volunteers were included and received during 5 h, on two occasions and in a random order, either an enteral infusion of maltodextrins alone (0.25 g kg(-1) h(-1), control), mimicking carbohydrate-fed state, or maltodextrins with glutamine (0.117 g kg(-1) h(-1), glutamine). Endoscopic duodenal biopsies were then taken. Total cellular protein extracts were separated by 2D gel electrophoresis and analyzed by an immunodetection using anti-ubiquitin antibody. Differentially ubiquitinated proteins were then identified by liquid chromatography-electrospray ionization MS/MS. Five proteins were differentially ubiquitinated between control and glutamine conditions. Among these proteins, we identified two chaperone proteins, Grp75 and hsp74. Grp75 was less ubiquitinated after glutamine infusion compared with control. In contrast, hsp74, also called Apg-2, was more ubiquitinated after glutamine. In conclusion, we provide evidence that glutamine may regulate ubiquitination processes of specific proteins, i.e., Grp75 and Apg-2. Grp75 has protective and anti-inflammatory properties, while Apg-2 indirectly regulates stress-induced cell survival and proliferation through interaction with ZO-1. Further studies should confirm these results in stress conditions.Amino Acids 01/2014; · 3.91 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Intensified aquaculture has strong impact on fish health by stress and infectious diseases and has stimulated the interest in the orchestration of cytokines and growth factors, particularly their influence by environmental factors, however, only scarce data are available on the GH/IGF-system, central physiological system for development and tissue shaping. Most recently, the capability of the host to cope with tissue damage has been postulated as critical for survival. Thus, the present study assessed the combined impacts of estrogens and bacterial infection on the insulin-like growth factors (IGF) and tumor-necrosis factor (TNF)-α. Juvenile rainbow trout were exposed to 2 different concentrations of 17β-estradiol (E2) and infected with Yersinia ruckeri. Gene expressions of IGF-I, IGF-II and TNF-α were measured in liver, head kidney and spleen and all 4 estrogen receptors (ERα1, ERα2, ERβ1 and ERβ2) known in rainbow trout were measured in liver. After 5 weeks of E2 treatment, hepatic up-regulation of ERα1 and ERα2, but down-regulation of ERß1 and ERß2 were observed in those groups receiving E2-enriched food. In liver, the results further indicate a suppressive effect of Yersinia-infection regardless of E2-treatment on day 3, but not of E2-treatment on IGF-I whilst TNF-α gene expression was not influenced by Yersinia-infection but was reduced after 5 weeks of E2-treatment. In spleen, the results show a stimulatory effect of Yersinia-infection, but not of E2-treatment on both, IGF-I and TNF-α gene expressions. In head kidney, E2 strongly suppressed both, IGF-I and TNF-α. To summarise, the treatment effects were tissue- and treatment-specific and point to a relevant role of IGF-I in infection.General and Comparative Endocrinology 05/2014; · 2.82 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: The goal of this work was to identify interleukin (IL)-related genes in the gilthead sea bream (GSB) (Sparus aurata L.) and how they are modulated by the parasite Enteromyxum leei, a myxozoan that causes severe enteritis with a strong inflammatory response. A Blast-X search of our transcriptomic GSB database (www.nutrigroup-iats.org/seabreamdb) identified 16 new sequences encompassing seven ILs (IL-7, IL-8, IL-10, IL-12β, IL-15, IL-18, and IL-34), the interleukin enhancer-binding factor 2 (ILF2), and eight IL receptors (IL-R); IL-R1, IL-6RA, IL-6RB, IL-8RA, IL-10RA, IL-10RB, IL-18R1, and IL-22R). Except for ILF2, their expression, plus that of IL-1β, IL-1R2, IL-6, and TNF-α (from public repositories), were analysed by 96-well PCR array of samples of blood, spleen, head kidney, and intestine of GSB that were anally intubated with E. leei (recipient group, RCPT). Only the expression profile of the intestine of RCPT fish showed significant difference as compared to samples from PBS-inoculated fish. At 17 days post inoculation (dpi), the expression of key pro-inflammatory ILs, such as IL-8, IL-8R, IL-12β, and TNFα was significantly up-regulated, whereas at 64 dpi, anti-inflammatory IL expression (IL-6, IL-6RB, IL-7, IL-10, IL-10RA, and IL-15) was predominant. These results indicate a modification of the IL expression at late times post infection, probably to protect the fish intestine from the parasite and damage inflicted by an excessive inflammatory response. Furthermore, the response is mainly mediated at the local level as no significant changes were detected in blood, spleen and head kidney.Fish & Shellfish Immunology 04/2014; · 2.96 Impact Factor