GAPDH Released from Lactobacillus johnsonii MG Enhances Barrier Function by Upregulating Genes Associated with Tight Junctions

• Published in: Microorganisms (Basel) Vol. 11; no. 6; p. 1393
• Main Authors: Lyu, Mengying, Bai, Yuying, Orihara, Kanami, Miyanaga, Kazuhiko, Yamamoto, Naoyuki
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 25.05.2023; MDPI
• Subjects: adhesion; Amino acid sequence; amino acid sequences; Amino acids; Antibodies; Bacteria; C-Terminus; Caco-2 cells; Cell surface; Cells; Damage detection; digestive system; epithelium; GAPDH; Gene expression; Genes; Glyceraldehyde-3-phosphate dehydrogenase; Hydrogen peroxide; JAM-2; Lactobacillus johnsonii; Liquid chromatography; Microbiota; N-Terminus; Peptides; Proteins; Regeneration; Tight junctions; United States > US; Japan; JAM-2; Caco-2 cells; tight junctions; Lactobacillus johnsonii; GAPDH
• ISSN: 2076-2607; 2076-2607
• DOI: 10.3390/microorganisms11061393

Extracellular glyceraldehyde-3-phosphate dehydrogenase (GAPDH) has multiple interactions with various gut epithelial components. For instance, GAPDH in Lactobacillus johnsonii MG cells interacts with junctional adhesion molecule-2 (JAM-2) in Caco-2 cells and enhances tight junctions. However, the specificity of GAPDH toward JAM-2 and its role in the tight junctions in Caco-2 cells remain unclear. In the present study, we assessed the effect of GAPDH on tight junction regeneration and explored the GAPDH peptide fragments required for interaction with JAM-2. GAPDH was specifically bound to JAM-2 and rescued H2O2-damaged tight junctions in Caco-2 cells, with various genes being upregulated in the tight junctions. To understand the specific amino acid sequence of GAPDH that interacts with JAM-2, peptides interacting with JAM-2 and L. johnsonii MG cells were purified using HPLC and predicted using TOF–MS analysis. Two peptides, namely 11GRIGRLAF18 at the N-terminus and 323SFTCQMVRTLLKFATL338 at the C-terminus, displayed good interactions and docking with JAM-2. In contrast, the long peptide 52DSTHGTFNHEVSATDDSIVVDGKKYRVYAEPQAQNIPW89 was predicted to bind to the bacterial cell surface. Overall, we revealed a novel role of GAPDH purified from L. johnsonii MG in promoting the regeneration of damaged tight junctions and identified the specific sequences of GAPDH involved in JAM-2 binding and MG cell interaction.