Integrated application of multi-omics strategies provides insights into
the environmental hypoxia response in Pelteobagrus vachelli muscle
Abstract
Abstract Increasing pressures on aquatic ecosystems due to pollutants,
nutrient enrichment and global warming have severely depleted oxygen
concentrations. This sudden and significant lack of oxygen has resulted
in persistent increases fish mortality rates. Revealing the molecular
mechanism of fish hypoxia adaptation will help researchers to find
hypoxic markers for hypoxia induced by environmental stress. Here, we
used a multi-omics approach to identify several hypoxia-associated
miRNAs, mRNAs, proteins, and metabolites involved in diverse biological
pathways in the muscles of Pelteobagrus vachelli. Our findings revealed
significant hypoxia-associated changes in muscles over 4 h of hypoxia
exposure and discrete tissue-specific patterns. We have previously
reported that P. vachelli livers exhibit increased anaerobic glycolysis,
heme synthesis, erythropoiesis, and inhibit apoptosis when exposed to
hypoxia 4 h. However, the opposite was observed in muscles. According to
our comprehensive analysis, fishes show an acute response to hypoxia,
including activation of catabolic pathways to generate more energy,
reduction of biosynthesis to decrease energy consumption, and shifting
from aerobic to anaerobic metabolic contributions. Also we found that
hypoxia induced muscle dysfunction by impairing mitochondrial function,
activating inflammasomes, and apoptosis. The hypoxia-induced
mitochondrial dysfunction enhanced oxidative stress, apoptosis, and
further triggered IL-1β production via inflammasome activation. In turn,
IL-1β further impaired mitochondrial function or apoptosis by
suppressing downstream mitochondrial biosynthesis-related proteins, thus
resulting in a vicious cycle of inflammasome activation and
mitochondrial dysfunction. Our findings contribute meaningful insights
into the molecular mechanisms of hypoxia, and the methods and study
design can be utilized across different fish species.