Lactobacillus acidophilus attenuates Aeromonas hydrophila induced cytotoxicity in catla thymus macrophages by modulating oxidative stress and inflammation.
The pathogenesis of Aeromonas hydrophila, a potent fish pathogen, is attributed to its ability to cause motile aeromonad septicaemia leading to apoptosis in a myriad of fish species, including freshwater carp Catla catla. However, the underlying mechanism of antagonistic activity of probiotics against A. hydrophila induced apoptosis is not elucidated due to lack of appropriate in-vitro models. This study reported that the exposure of catla thymus macrophages (CTM) to A. hydrophila markedly induced cellular injuries as evidenced by elevated levels of reactive oxygen species (ROS), reactive nitrogen species (RNS), increased apoptosis, DNA damage and decreased cellular viability. Flow cytometry analysis and Annexin-V/propidium iodide assay further confirmed increased ROS positive cells leading to cell death after infection. The quantitative real-time PCR analysis, also revealed upregulation of inducible nitric-oxide synthase (iNOS), pro-inflammatory cytokine (TNFα), cyclooxygenase2 (COX-2) and downregulation of anti-inflammatory cytokine (IL-10). Pretreatment of cells with probiotic, Lactobacillus acidophilus attenuated A. hydrophila induced apoptosis as evident from the decrease in the levels of ROS, RNS and DNA damage. Significant increase (P≤0.05) in expression of TNFα and IL-10 and decrease in iNOS and COX-2 was observed on probiotic stimulation. In-vivo study using catla fingerlings confirmed similar pattern of ROS, iNOS, NO production and cytokine expression in thymus. This study provides a comprehensive insight into the mechanistic basis of L. acidophilus induced macrophage mediated inflammatory response against A. hydrophila in CTM cells. Further, it speculates the possibility of using cost-effective in-vitro models for screening probiotic candidates of therapeutic potential in aquaculture industry.
Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela, 769 008, Odisha, India.
Bhakti
B
Patel
School of Biotechnology, KIIT University, Bhubaneswar, 751024, Odisha, India.
Premranjan
P
Kumar
Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela, 769 008, Odisha, India.
Rajanya
R
Banerjee
Fish Health Management Division, Central Institute of Freshwater Aquaculture, Kausalyanga, Bhubaneswar, 751002, Odisha, India.
Madhubanti
M
Basu
School of Biotechnology, KIIT University, Bhubaneswar, 751024, Odisha, India.
Arttatrana
A
Pal
Fish Health Management Division, Central Institute of Freshwater Aquaculture, Kausalyanga, Bhubaneswar, 751002, Odisha, India.
Mrinal
M
Samanta
Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela, 769 008, Odisha, India. Electronic address: surajit@nitrkl.ac.in.
Surajit
S
Das
D016980:Aeromonas hydrophila; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D017756:Aquaculture; D002347:Carps; D020552:Comet Assay; D005393:Fish Diseases / Q000276:immunology*; D005434:Flow Cytometry; D016905:Gram-Negative Bacterial Infections / Q000662:veterinary*; D007249:Inflammation / Q000276:immunology; D007779:Lactobacillus acidophilus; D008264:Macrophages / Q000276:immunology* / Q000382:microbiology; D018384:Oxidative Stress / Q000187:drug effects*; D016133:Polymerase Chain Reaction; D019936:Probiotics / Q000494:pharmacology*
Aeromonas hydrophila; Catla thymus macrophage; Immunomodulation; Probiotic; ROS