- Immunology, College of Medicine, University of Manitoba, Winnipeg, MB, Canada
Nour Eissa
University of Manitoba, Immunology, Department Member
- Molecular Genetics, Immunobiology, Stress Responses (Cellular Biology), Functional Genomics, ELISA, Cortisol, and 14 moreGrowth, Immunology, Microbiology, Biological Control, Probiotics, Fish Diseases, Pseudomonas, Statistics, Stress, Animal Welfare, Behavior, Welfare, Biochemistry, and Evolutionary Biologyedit
Ulcerative colitis (UC) is characterized by a functional dysregulation of alternatively activated macrophage (AAM) and intestinal epithelial cells (IECs) homeostasis. Chromogranin-A (CHGA) secreted by neuroendocrine cells is implicated in... more
Ulcerative colitis (UC) is characterized by a functional dysregulation of alternatively activated macrophage (AAM) and intestinal epithelial cells (IECs) homeostasis. Chromogranin-A (CHGA) secreted by neuroendocrine cells is implicated in intestinal inflammation and immune dysregulation. CHGA undergoes proteolytic processing to generate CHGA-derived peptides. Chromofungin (CHR: CHGA47–66) is a short CHGA-derived peptide encoded by CHGA Exon-IV and is involved in innate immune regulation, but the basis is poorly investigated. We investigated the expression of CHR in colonic tissue of patients with active UC and assessed the effects of the CHR in dextran sulfate sodium (DSS) colitis in mice and on macrophages and human colonic epithelial cells. We found that mRNA expression of CHR correlated positively with mRNA levels of AAM markers and gene expression of tight junction (TJ) proteins and negatively with mRNA levels of interleukin (IL)-8, IL-18, and collagen in patients with active UC. Moreover, AAM markers correlated positively with gene expression of TJ proteins and negatively with IL-8, IL-18, and collagen gene expression. Experimentally, intracolonic administration of CHR protected against DSS-induced colitis by priming macrophages into AAM, reducing colonic collagen deposition, and maintaining IECs homeostasis. This effect was associated with a significant increase of AAM markers, reduction of colonic IL-18 release and conservation of gene expression of TJ proteins. In vitro, CHR enhanced AAM polarization and increased the production of anti-inflammatory mediators. CHR-treated AAM conditioned medium increased Caco-2 cell migration, viability, proliferation, and mRNA levels of TJ proteins, and decreased oxidative stress-induced apoptosis and proinflammatory cytokines release. Direct CHR treatments had the same effect. In conclusion, CHR treatment reduces the severity of colitis and the inflammatory process via enhancing AAM functions and maintaining IECs homeostasis. CHR is involved in the pathogenesis of inflammation in experimental colitis. These findings provide insight into the mechanisms of colonic inflammation and could lead to new therapeutic strategies for UC.
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Retinoic acid (RA), an active metabolite of vitamin A, has shown potential therapeutic immunomodulatory properties. Allogeneic mesenchymal stem cells (MSCs)-based therapy is an effective approach to induce tissue healing and regeneration... more
Retinoic acid (RA), an active metabolite of vitamin A, has shown potential therapeutic immunomodulatory properties. Allogeneic mesenchymal stem cells (MSCs)-based therapy is an effective approach to induce tissue healing and regeneration in many equine orthopedic conditions. However, MSCs-based therapies induced inflammatory responses in vivo. This study aimed to: 1. Determine the effect of RA cell culture treatment on inflammatory responses of lipopolysaccharides (LPS)-and allogeneic MSCs-stimulated peripheral blood mono-nuclear cells (PBMCs). 2. Determine the effect of RA on stimulated MSCs viability and morphology. Allogeneic MSCs-stimulated PBMCs had significant decreases in the anti-inflammatory cytokines (IL-10, IL-1ra, TGF-β1), increases in the pro-inflammatory mediators (IL-1β, IL-6, TNF-α, SAA), and increases of CD14 and MHC II percent positive cells compared to LPS-and non-stimulated PBMCs. Retinoic acid treatment of LPS-and allogeneic MSCs-stimulated PBMCs counterbalanced the induced inflammatory responses. Moreover, RA significantly improved the viability and morphology of stimulated MSCs. These findings highlighted the potential complications of equine allogeneic MSCs-based therapies and the immuno-modulatory effect of RA on equine stimulated cells. In conclusion, the use of RA to ameliorate allogeneic MSCs therapy associated inflammation may offer advantages that would require further investigations.
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Background
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The mammalian intestinal tract is heavily colonized with a dense, complex, and diversified microbial populations. In healthy individuals, an array of epithelial antimicrobial agents is secreted in the gut to aid intestinal homeostasis.... more
The mammalian intestinal tract is heavily colonized with a dense, complex, and diversified microbial populations. In healthy individuals, an array of epithelial antimicrobial agents is secreted in the gut to aid intestinal homeostasis. Enterochromaffin cells (EC) in the intestinal epithelium are a major source of chromogranin A (CgA), which is a pro-hormone and can be cleaved into many bioactive peptides that include catestatin (CST). This study was carried out to evaluate the possible impact of CST on gut microbiota in vivo using a mouse model. The CST (Human CgA 352−372) or normal saline was intrarectally administered in C57BL/6 male mice for 6 days and then sacrificed. Feces and colonic mucosa tissue samples were collected, DNA was extracted, the V4 region of bacterial 16S rRNA gene was amplified and subjected to MiSeq Illumina sequencing. The α-diversity was calculated using Chao 1 and β-diversity was determined using QIIME. Differences at the genus level were determined using partial least square discriminant analysis (PLS-DA). Phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) was used to predict functional capacity of bacterial community. CST treatment did not modify bacterial richness in fecal and colonic mucosa-associated microbiota; however, treatment significantly modified bacterial community composition between the groups. Also, CST-treated mice had a significantly lower relative abundance of Firmicutes and higher abundance of Bacteroidetes, observed only in fecal samples. However, at lower phylogenetic levels, PLS-DA analysis revealed that some bacterial taxa were significantly associated with the CST-treated mice in both fecal and colonic mucosa samples. In addition, differences in predicted microbial functional pathways in both fecal and colonic mucosa samples were detected. The results support the hypothesis that CST treatment modulates gut microbiota composition under non-pathophysiological conditions, however, the result of this study needs to be further validated in a larger experiment. The data may open new avenues for the development of a potential new line of antimicrobial peptides and their use as therapeutic agents to treat several inflammatory conditions of the gastrointestinal tract, such as inflammatory bowel disease (IBD), inflammatory bowel syndrome (IBS), or other health conditions.
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2,4-Dinitrobenzene sulfonic acid (DNBS)-induced colitis is an experimental model that mimics Crohn's disease. Appropriateness of reference genes is crucial for RT-qPCR. This is the first study to determine the stability of reference gene... more
2,4-Dinitrobenzene sulfonic acid (DNBS)-induced colitis is an experimental model that mimics Crohn's disease. Appropriateness of reference genes is crucial for RT-qPCR. This is the first study to determine the stability of reference gene expression (RGE) in mice treated with DNBS. DNBS experimental Colitis was induced in male C57BL/6 mice. RNA was extracted from colon tissue and comprehensive analysis of 13 RGE was performed according to predefined criteria. Relative colonic TNF-α and IL-1β mRNA levels were calculated. Colitis significantly altered the stability of mucosal RGE. Commonly used glyceraldehyde-3-phosphate dehydrogenase (Gapdh), β-actin (Actb), or β2-microglobulin (β2m) showed the highest fluctuation within the inflamed and control groups. Conversely, ribosomal protein large P0 (Rplp0), non-POU domain containing (Nono), TATA-box-binding protein (Tbp) and eukaryotic translation elongation factor 2 (Eef2) were not affected by inflammation and were the most stable genes. TNF-α and IL-1β mRNA levels was dependent on the reference gene used and varied from significant when the most stable genes were used to non-significant when the least stable genes were used. The appropriate choice of RGE is critical to guarantee satisfactory normalization of RT-qPCR data when using DNBS-Model. We recommend using Rplp0, Nono, Tbp, Hprt and Eef2 instead of common reference genes. Inflammatory bowel diseases (IBDs) are idiopathic, chronic, and relapsing gastro-intestinal inflammatory disorders that are characterized by abdominal pain, weight loss and diarrhea. Ulcerative colitis (UC) and Crohn's disease (CD) are the two main forms of IBD and they have both overlapping and distinct clinical and pathological features; however, they can be distinguished by the location of the inflammation within the gastro-intestinal (GI) tract 1. The etiology of IBD is unknown, but there are several factors that may contribute to its pathophysi-ology such as genetic factors, immune system dysregulation, microbial dysbiosis, stress, and disruption of tight junctions. To investigate these different etiological factors, many experimental models are available and include chemical-induced and transgenic animal models, spontaneous models and genetically engineered 2. Animal models of IBD are a main source of information about the pathophysiology and are clinically relevant to both human UC and CD. Because of their low cost and rapid onset of disease, chemical-induced colitis models are considered valuable tools to study various aspects of IBD. The dextran sulfate sodium (DSS) model, a model of injury-repair mimicking UC, is one of the most common chemical models used to induce colitis in rodents 3 , but the model needs to be well-controlled to avoid variation in DSS concentration, and inconsistent water uptake by mice resulting
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Twenty four New-Zealand White rabbits of both genders (12 males and 12 females), 4 weeks old, with nearly equal body weight at the beginning of the experiment, were randomly allotted to three groups of 8 rabbit each (4 males and 4... more
Twenty four New-Zealand White rabbits of both genders (12 males and 12 females), 4 weeks old, with nearly equal body weight at the beginning of the experiment, were randomly allotted to three groups of 8 rabbit each (4 males and 4 females). Three groups were established according to the cage floor type. The first group was raised on wire mesh cage floor throughout the experiment. The second group was raised on plastic hollow mat and the third was on rubber hollow mat. Rabbits were weighed at the beginning of the experiment and at weekly intervals thereafter during the experimental period (7 weeks). Individual body weight and feed consumption throughout the experiment were recorded weekly. Body weight gain, feed conversion ratio, ear and eye lesions, total and differential Leukocytes count were also calculated. The results demonstrated that the cage floor type affected drinking and agonistic behavior but did not affect any other behaviors. Rabbits raised on wire mesh floor showed the highest proportion of agonistic behavior. The cage floor type had no influence on BW, feed consumption, BW gain and feed conversion ratio of growing rabbit during the last three weeks of experiment. The incidence of ear and eye lesions was higher in cages with wire mesh (25%) than cages with plastic and rubber mat floor (12.5%). Wire caged rabbits revealed significant increase in white blood cells and lymphocyte counts. It could be suggested that placing of plastic or rubber mat on wire mesh of rabbit' cages has an important effect on reducing the incidence of ear and eye lesions caused by aggressive behaviors and reducing the effect of stress on the total and differential Leukocytes count, as well as improving their welfare state.
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Global temperature climate changes affect stress, immune function and growth of aquatic animals. The aim of this study was to investigate the effect of different temperatures on oxidative stress, thermal stress, immune response and growth... more
Global temperature climate changes affect stress, immune function and growth of aquatic animals. The aim of this study was to investigate the effect of different temperatures on oxidative stress, thermal stress, immune response and growth in bluegill sunfish (Lepomis macrochirus). The experiment included four groups that were exposed to different water temperatures: 10ºC (10.2 ± 0.05), 20ºC (20 ± 0.06), 30ºC (29.7 ± 0.09), and 35ºC (34.7 ± 0.05) for six weeks. Fish were sampled at day 0, 3 weeks, and 6 weeks. Significantly higher (P < 0.05) erythrocyte lysate superoxide dismutase (SOD) wasobserved in the 10ºC, 30ºC and 35ºC groups at day 0 and 3 week, but more pronounced at the 6th week. Heat Shock protein90 (HSP-90) was significantly up-regulated at higher temperatures (20, 30, and 35ºC), while down-regulated at 10ºC. Similarly, immune response biomarker α-2-macroglobulin (A2M) was also up-regulated in 20 and 30ºC groups whereas down-regulated in 10ºC group. All groups exhibited 100% survival except the 35ºC group (86% survival). The highest growth performance was observed for the 30ºC group and the lowest for the 10ºC group. Conclusively, findings support that SOD, HSP-90 and A2M could be considered as biomarkers for climate change and environmental monitoring as referred in fish species.
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In the present study a commercial probiotic Fishery Prime TM , acting as water soluble probiotic, was administered to Yellow Perch (Perca flavescens) for 6 weeks. The probiotic effect on growth and growth regulated genes were evaluated... more
In the present study a commercial probiotic Fishery Prime TM , acting as water soluble probiotic, was administered to Yellow Perch (Perca flavescens) for 6 weeks. The probiotic effect on growth and growth regulated genes were evaluated with respect to fish group fed on commercial feed (control group). Measures of body weight were performed to assess the growth performance. In addition, the expression of two related and highly indicative candidate genes involved in growth (Insulin-Like Growth Factor IGF-I and Growth Hormone GH) were quantified through real-time PCR. Fish received the probiotic exhibited higher growth performance than control group at significance level (p < 0.05).Up regulation of GH and IGF-I transcriptions were observed in fish group received with probiotic which revealed higher levels than the control. The results confirmed the positive correlation between growth performance, GH and IGF-I mRNA gene expression in both probiotic treated and control groups. In conclusion, probiotic during early developmental stages can confer maximum beneficial effects resulting in magnitude increase in survivorship.
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The main goal of this work was to determine the effect of water soluble commercial probiotic on the transcriptional analysis of the anti-oxidative status of yellow perch. Glutathione peroxidase (GPX), superoxide dismutase (SOD), and... more
The main goal of this work was to determine the effect of water soluble commercial probiotic on the transcriptional analysis of the anti-oxidative status of yellow perch. Glutathione peroxidase (GPX), superoxide dismutase (SOD), and cytochrome oxidase subunit I (COI) were analyzed in yellow perch at 25and50 days after receiving the probiotic with respect to the control group by real time quantitativepolymerase chain reaction.Two yellow perchgroups fed on commercial feed:groupone, received the probiotic in the waterandthecontrolgroupwithout probiotic addition.Thegroupreceived the probiotic revealed lowerexpressionlevelsof GPX, SODand COIcomparedtothecontrol group at 25 and 50 days.Inour workthedifferencesin geneexpressionpatternscould onlybeattributedtothe presence ofprobiotic,assumingapossible involvement ofprobiotic in the modulation of the antioxidant system in the fish. This study can conclude that among probiotic beneficial effects, it also could provideprotection against oxidative stress and the ability to decline the risk of accumulation of reactive oxygen metabolites which are harmful to the host.
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Stress of aquatic animals occurs due to physical and physiological disturbances in the aquatic environment or system when transportation, crowding, handling or changes of physical and chemical factors take place. There are three... more
Stress of aquatic animals occurs due to physical and physiological disturbances in the aquatic environment or system when transportation, crowding, handling or changes of physical and chemical factors take place. There are three regulatory systems having a vital role in stress response: the neural, endocrine and immune systems. Fish exhibit multiple genomic and physiological responses to adjust the compensatory or adaptive mechanism that allows them to mitigate the stressors, maintain their haemostasis and survive. In this review, we describe multiple important genes that are associated with responses to environmental and husbandry stressors and that could be used as biomarkers of environmental and husbandry stressors in fish. The described environmental and husbandry stressors include salinity, temperature, hypoxia and hyperoxia, confinement, density and handling. The main role of stress response in aquatic animals is to compensate or adapt their biological systems and arrange the metabolism to afford the energy required by the stressor and a wide array of metabolic processes and pathways are involved. We summarized and discussed highly significant genes in several organs and tissues that are involved and active during this adaption process. The traditional stress biomarkers in some circumstances have some difficulties in interpretation of results and lead to tricky diagnosis and searching and understanding alternative tools is critical for aquaculture, fisheries and fish welfare. Using genomic tools to study the candidate genes associated with stress responses are often unique signatures or imprints of specific stressors and could determine early signs of stressors.
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Pseudomonas fluorescens biovars were isolated from Oreochromis niloticus collected from Qaroun Lake fish farms, Egypt. Microorganisms were added to basal diet with 30 % protein to assess their probiotic properties on growth-performance,... more
Pseudomonas fluorescens biovars were isolated from Oreochromis niloticus collected from Qaroun Lake fish farms, Egypt. Microorganisms were added to basal diet with 30 % protein to assess their probiotic properties on growth-performance, hematological parameters, enzymatic activities and survival rate. Tilapia (2.93 ± 0.22 g) were distributed into four equal groups, three replicates each. First group were fed on basal diet as control group, 2nd, 3rd and 4th groups were fed on diet supplemented with Pseudomonas fluorescens biovar I, II & III respectively; fish were fed twice daily at the rate of 5-7 % of their body weight for 45 days. The groups were challenged intra-peritoneal with Aeromonas hydrophila (1.8 x 108 CFU ml−1) and observed for 7 days. The growth rate was significantly higher in groups fed on Pseudomonas fluorescens in the diet than control group. Hematological and non-specific immune parameters were significantly higher than control group. The highest protein, globulin, glucose, Plasma aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenases activity were observed at 3rd group which fed on Pseudomonas fluorescens biovar II. The challenged fish exhibited lowest cumulative mortality rate in 3rd group (10%) compared to control group (90%). So, it could be concluded that non-pathogenic pseudomonas isolates from marine or brackish water could confer beneficiary effects for Nile tilapia through improving growth performance, immunity enhancement and resistance against diseases.