Transcriptional Profiling of The Bovine Hepatic Response to Experimentally Induced E. coli Mastitis

The mammalian liver works to keep the body in a state of homeostasis and plays an important role in systemic acute phase response to infections. In this study we investigated the bovine hepatic acute phase response at the gene transcription level in dairy cows with experimentally Escherichia coli-induced mastitis. At time = 0, each of 16 periparturient dairy cows received 20–40 colony-forming units of live E. coli in one front quarter of the udder. A time series of liver biopsies was collected at −144, 12, 24, and 192 h relative to time of inoculation. Changes in transcription levels in response to E. coli inoculation were analyzed using the Bovine Genome Array and tested significant for 408 transcripts over the time series [adjusted p ≤0.05, abs(fold-change)>2]. After 2-D clustering, transcripts represented three distinct transcription profiles: 1) regulation of gene transcription and apoptosis, 2) responses to cellular stress invoked by reactive metabolites, and 3) metabolism and turnover of proteins. T...