The Role of the TLR4-MyD88 Signaling Pathway in the Immune Response of the Selected Scallop Strain "Hongmo No. 1" to Heat Stress.
Chenyang YueKexin ZhangZhigang LiuWengang LüHui GuoLiqiang ZhaoXinyu SongJames Kar-Hei FangPublished in: Animals : an open access journal from MDPI (2024)
The innate immunity of marine bivalves is challenged upon exposure to heat stress, especially with increases in the frequency and intensity of heat waves. TLR4 serves a classical pattern recognition receptor in recognizing pathogenic microorganisms and activating immune responses. In this study, three genes, HMTLR4 , HMMyD88 and HMTRAF6 , were characterized as homologs of genes in the TLR4-MyD88 signaling pathway in the selected scallop strain "Hongmo No. 1". According to RT-PCR, acute heat stress (32 °C) inhibited genes in the TLR4-MyD88 signaling pathway, and LPS stimulation-induced activation of TLR4-MyD88 signal transduction was also negatively affected at 32 °C. ELISA showed LPS-induced tumor necrosis factor alpha (TNF-α) or lysozyme (LZM) activity, but this was independent of temperature. RNA interference (RNAi) confirmed that HMTLR4 silencing suppressed the expression of its downstream gene, whether at 24 °C or at 32 °C. The level of TNF-α and the activity of LZM also decreased after injection with dsRNA, indicating a negative effect on the innate immunity of scallops. Additionally, acute heat stress affected the suppression of downstream gene expression when compared with that at 24 °C, which led us to the hypothesis that heat stress directly influences the downstream targets of HMTLR4 . These results enrich the knowledge of scallop immunity under heat stress and can be beneficial for the genetic improvement of new scallop strains with higher thermotolerance.
Keyphrases
- heat stress
- toll like receptor
- immune response
- inflammatory response
- signaling pathway
- lps induced
- heat shock
- genome wide
- nuclear factor
- gene expression
- rheumatoid arthritis
- pi k akt
- genome wide identification
- liver failure
- dna methylation
- epithelial mesenchymal transition
- drug induced
- respiratory failure
- bioinformatics analysis
- healthcare
- poor prognosis
- copy number
- genome wide analysis
- binding protein
- escherichia coli
- aortic dissection
- anti inflammatory
- intensive care unit
- cell proliferation
- ultrasound guided
- long non coding rna
- high glucose
- endothelial cells
- monoclonal antibody
- high intensity
- transcription factor
- oxidative stress