To test the dynamic changes of the expression of genes and
microRNA in the gastrocnemius muscle after LPS challenge, 36 piglets were assigned to a control group (slaughtered 0 h after saline injection) and LPS groups (slaughtered at 1 h, 2 h, 4 h, 8 h, and 12 h after LPS treatment, respectively). After LPS treatment, the
mRNA expression of IL-1β,
IL-6, and TNF-α reached maximal levels at 1 h, 2 h, and 1 h, respectively (P < 0.05), and
mRNA expression of TLR4, NODs, muscle-specific ring finger 1, and
muscle atrophy F-box peaked at 12 h (P < 0.05). Moreover, the expression of miR-122, miR-135a, and miR-370 reduced at 1 h, 1 h, and 2 h, respectively (P < 0.05), and miR-34a, miR-224, miR-132, and miR-145 reached maximum expression levels at 1 h, 1 h, 2 h, and 4 h, respectively (P < 0.05). These results suggested that
mRNA expression of pro-inflammatory
cytokines was elevated in the early stage,
mRNA expression of genes related to TLR4 and NODs signaling pathways and protein degradation increased in the later phase, and the expression of
microRNA related to muscle
inflammation and protein degradation changed in the early stage after LPS injection.