Work

fliC Mediates Pseudomonas plecoglossicida’s Hijack of Inflammatory Immunity and Glucose Metabolism in the Large Yellow Croaker

Year: 2025

Type: article

Abstract: The bacterial flagellum plays a crucial role in pathogenesis. However, the mechanism by which the flagellum interferes with host energy metabolism remains unclear. In this study, we confirmed that deletion of the fliC gene resulted in a 30% reduction in the virulence of Pseudomonas plecoglossicida against the large yellow croaker (Larimichthys crocea). Compared to the wild-type strain (WT) infection group, the ΔfliC infection group exhibited a 29.54% decrease in the number of vacuolar degeneration hepatocytes and a 50.83% higher liver glycogen content. Furthermore, infection led to decreased mitochondrial complex V activity, a reduced NAD+/NADH ratio, lower levels of reduced glutathione (GSH), and increased lipid peroxide levels; however, these metabolic perturbations were significantly ameliorated in the ΔfliC group compared to the WT group. Proteomic analysis revealed that the dysregulation of the complement cascade and core carbon metabolic pathways observed in the WT infection group liver was significantly alleviated in the ΔfliC infection group. Additionally, in the ΔfliC infection group, pro-inflammatory genes (such as Tlr5, Tnfα, and Il1β) were downregulated, while lipid metabolism-related genes (such as Acox1, Cpt1a, and Pparα) were upregulated, suggesting the suppression of the Tlr5/NF-κB immune signaling axis and enhanced fatty acid β-oxidation. Collectively, fliC may mediate the disruption of host glucose and lipid metabolism homeostasis through a Tlr5-triggered immunometabolic regulatory axis. In conclusion, this study demonstrates that bacterial flagella modulate host energy metabolism, expanding our understanding of flagellum-mediated pathogenesis.

Source: Antioxidants

DOI: 10.3390/antiox14101189

Authors: Xizhi Peng, Yujia Sun, Huanjiao Tan, Huanying Pang, Caiyuan Zhao, Qingpi Yan

Institutions: Jimei University, Guangdong Ocean University, Henan University of Animal Husbandry and Economy

Language: English

Topic: Aquaculture disease management and microbiota

Subfield: Immunology

Field: Immunology and Microbiology

Domain: Life Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $3,499