Biomedical subjects

Gerold Bongers

Publications and source records attributed to Gerold Bongers.

3 recordsLinked to original sources

PubMed2026

Defined human Clostridia consortia reverse colitis via dual effects of tryptophan metabolites on microbiota and immunity.

Microbial dysbiosis and disrupted mucosal immune homeostasis are integrally involved in the pathogenesis of inflammatory bowel diseases (IBDs). Live biotherapeutic products (LBPs) offer a potential therapeutic strategy to restore beneficial microbes and mitigate disease. We investigated the therapeutic efficacy of 2 LBPs, human Clostridia consortia 17-mix and 11-mix, by treating established colitis in murine models. Both LBPs exhibited therapeutic effects in T cell-mediated chronic colitis models induced by human microbiota and in pathobiont-driven gnotobiotic colitis models established with combinations of IBD-relevant human-derived strains. Metagenomic and metabolomic analyses elucidated mechanisms that go beyond established functions driven by short-chain fatty acids (SCFAs) and interleukin (IL)-10-producing regulatory T cells. Notably, LBPs exerted therapeutic effects by directly inhibiting resident pathobionts and through IL-10-independent activation of host anti-inflammatory aryl hydrocarbon receptor (AhR) pathways by bacterial tryptophan metabolites. These results elucidate SCFA- and IL-10-independent protective mechanisms exerted by defined resident bacterial strains that are depleted in IBD dysbiosis.

Animals↗

PubMed2005

New high affinity H3 receptor agonists without a basic side chain.

In this study, we replaced the basic amine function of the known histamine H(3) receptor agonists imbutamine or immepip with non-basic alcohol or hydrocarbon moieties. All compounds in this study show a moderate to high affinity for the cloned human H(3) receptor and, unexpectedly, almost all of them act as potent agonists. Moreover, in the alcohol series, we consistently observed an increased selectivity for the human H(3) receptor over the human H(4) receptor, but none of the compounds in this series possess increased affinity and functional activity compared to their alkylamine congeners. In this new series of compounds VUF5657, 5-(1H-imidazol-4-yl)-pentan-1-ol, is the most potent histamine H(3) receptor agonist (pK(i) = 8.0 and pEC(50) = 8.1) with a 320-fold selectivity at the human H(3) receptor over the human H(4) receptor.

Cell Line, Tumor↗

PubMed2002

Androgens protect against apolipoprotein E4-induced cognitive deficits.

Compared with apolipoprotein (apo) E2 and E3, apoE4 increases the risk of Alzheimer's disease (AD), but it remains unknown how apoE4 affects neuronal function. ApoE4 interacts with female gender, further increasing the risk of AD and decreasing treatment response. Female mice are also more susceptible to apoE4-induced impairments of spatial learning and memory than male mice. To assess the role of sex steroids in this process, we studied mice deficient in mouse apoE (Apoe(-/-)) and expressing human apoE4 or apoE3 in the brain at comparable levels. Even brief periods of androgen treatment improved the memory deficits of female apoE4 mice. Female apoE3 mice had no memory deficits and did not benefit from the treatment. ApoE4 male mice, which performed normally in a water-maze test at baseline, developed prominent deficits in spatial learning and memory after blockade of androgen receptors (ARs), whereas apoE3 male mice did not. Untreated apoE4 mice had significantly lower cytosolic AR levels in the neocortex than wild-type, Apoe(-/-), and apoE3 mice. Improved memory in androgen-treated female apoE4 mice was associated with increased cytosolic AR levels. Our findings suggest that apoE4 contributes to cognitive decline by reducing AR levels in the brain, and that stimulating AR-dependent pathways can reverse apoE4-induced cognitive deficits.

Androgen Antagonists↗