The Mass Spectrometry society of Japan - The 68th Annual Conference on Mass Spectrometry, Japan

Abstract

Oral Sessions

Day 1, June 22(Wed.) 17:10-17:30 Room A (Main Hall)

Proteomic analysis reveals the gut microbiota as a novel regulator of host trypsin protease

(1Res. Inst. Child, 2Univ. Tokyo Hosp., 3Kazusa DNA Res. Inst.)
oEiichiiro Watanabe1,2, Yusuke Kawashima3

We successfully established an overlapping window DIA-based proteome analysis using noninvasive fecal and stool samples.
First, with our sophisticated fecal and stool proteome analysis, we analyzed the cecal contents from Germ-free (GF) vs Specific-pathogen-free (SPF) mice and trypsin (PRSS2), a serine protease, produced by the pancreas, was found to be significantly reduced in the cecum of SPF mice (Fig.1). Further analysis revealed that the reduction of trypsin only occurred in the cecum and colon, but not in the pancreas or small intestine, indicating that the decrease was not due to differential trypsin production or secretion, but was likely mediated by the commensal bacteria colonizing in the cecum and colon in SPF mice.
Next, gnotobiotic experiments demonstrated that healthy human volunteers had ‘trypsin degrading’ strains, and narrow down experiments revealed that Paraprevotella clara was isolated as a species responsible for trypsin degradation. The degradation of trypsin facilitated by Paraprevotella clara was eventually confirmed by our in vitro peptidomic analysis, and the sequential proteomic experiments lead to elucidate the mechanism of trypsin degradation by Paraprevotella spp.
Finally, we revealed that trypsin degradation in the colon could ameliorate clinical courses of mice infected with murine hepatitis virus 2, a mouse-tropic coronavirus.
In conclusion, mass spectrometry-based proteomic and peptidomic analysis have great potential in the field of microbiome research.