Expression of specific protein(s) in brain, brainstem and spinal cord of rabies infected dogs

Abstract

Furious and paralytic forms of rabies are unique clinical entities. They have been recognized particularly in rabies infected humans and dogs. The underlying mechanisms remained unclear. . We investigated host responses as determined by changes in the cellular proteome of nervous tissue samples from naturally rabies infected furious and paralytic dogs during late stage as compared to non-infected controls. Proteins were extracted from these tissues and analyzed by two-dimensional gel electrophoresis (2-DE). These proteins were then identified by quadrupole time-of-flight mass spectrometry and tandem mass spectrometry (Q-TOF MS and MS/MS) and were validated by real-time PCR. From >1,000 protein spots visualized in each gel, spot matching, quantitative intensity analysis and ANOVA with Tukey’s post-hoc multiple comparisons revealed 32, 49 and 67 protein spots that were differentially expressed among the three clinical groups in hippocampus, brainstem and spinal cord, respectively., including anti-oxidants, apoptosis-related proteins, cytoskeletal proteins, heat shock proteins/ chaperones, immune regulatory proteins, metabolic enzymes, neuron-specific proteins, transcription/translation regulators, ubiquitination/proteasome-related proteins, vesicular transport proteins, and hypothetical proteins. Among these, 13, 17 and 41 proteins in hippocampus, brainstem and spinal cord, respectively, significantly differed between paralytic and furious forms, and thus may potentially be biomarkers to differentiate these two distinct forms of rabies. In summary, we report herein for the first time a large dataset of changes in proteomes of hippocampus, brainstem and spinal cord in dogs naturally infected with rabies. These data will be useful for better understanding of molecular mechanisms of rabies and for differentiation of its paralytic and furious forms.