| First Author | Papoutsopoulou S | Year | 2022 |
| Journal | Am J Physiol Gastrointest Liver Physiol | Volume | 323 |
| Issue | 4 | Pages | G306-G317 |
| PubMed ID | 35916405 | Mgi Jnum | J:357325 |
| Mgi Id | MGI:7434932 | Doi | 10.1152/ajpgi.00037.2022 |
| Citation | Papoutsopoulou S, et al. (2022) Nfkb2 deficiency and its impact on plasma cells and immunoglobulin expression in murine small intestinal mucosa. Am J Physiol Gastrointest Liver Physiol 323(4):G306-G317 |
| abstractText | The alternative (noncanonical) nuclear factor-kappaB (NF-kappaB) signaling pathway predominantly regulates the function of the p52/RelB heterodimer. Germline Nfkb2 deficiency in mice leads to loss of p100/p52 protein and offers protection against a variety of gastrointestinal conditions, including azoxymethane/dextran sulfate sodium (DSS)-induced colitis-associated cancer and lipopolysaccharide (LPS)-induced small intestinal epithelial apoptosis. However, the common underlying protective mechanisms have not yet been fully elucidated. We applied high-throughput RNA-Seq and proteomic analyses to characterize the transcriptional and protein signatures of the small intestinal mucosa of naive adult Nfkb2(-/-) mice. Those data were validated by immunohistochemistry and quantitative ELISA using both small intestinal tissue lysates and serum. We identified a B-lymphocyte defect as a major transcriptional signature in the small intestinal mucosa and immunoglobulin A as the most downregulated protein by proteomic analysis in Nfkb2(-/-) mice. Small intestinal immunoglobulins were dramatically dysregulated, with undetectable levels of immunoglobulin A and greatly increased amounts of immunoglobulin M being detected. The numbers of IgA-producing, cluster of differentiation (CD)138-positive plasma cells were also reduced in the lamina propria of the small intestinal villi of Nfkb2(-/-) mice. This phenotype was even more striking in the small intestinal mucosa of RelB(-/-) mice, although these mice were equally sensitive to LPS-induced intestinal apoptosis as their RelB(+/+) wild-type counterparts. NF-kappaB2/p52 deficiency confers resistance to LPS-induced small intestinal apoptosis and also appears to regulate the plasma cell population and immunoglobulin levels within the gut.NEW & NOTEWORTHY Novel transcriptomic analysis of murine proximal intestinal mucosa revealed an unexpected B cell signature in Nfkb2(-/-) mice. In-depth analysis revealed a defect in the CD38+ B cell population and a gut-specific dysregulation of immunoglobulin levels. |
