Adrenal and Gonadal Hormone Variations during a Febrile Attack in a Woman with Tumor Necrosis Factor Receptor-Associated Periodic Syndrome

Context: TNF-receptor-associated periodic syndrome (TRAPS) is a hereditary fever syndrome that results from mutations in the TNF-receptor superfamily 1A gene (TNFRSF1A). It is characterized by periodic fever, arthralgia, abdominal pain, myalgia, headache, and skin lesions. Objective: Because adrenal and gonadal hormone cascades are modulated by TNF, this study aimed to investigate specific hormones and enzyme steps during an attack phase in a woman with TRAPS. Design: Morning blood samples were taken from a 38-yr-old woman before, during, and after the febrile episode in the late luteal, menstrual, and early follicular phase of the menstrual cycle, respectively. Results: Serum cortisol levels were markedly increased throughout the entire observation period and demonstrated a dip during the attack phase. In contrast, serum levels of dehydroepiandrosterone and 17-hydroxyprogesterone demonstrated a sharp rise during the febrile episode. Dehydroepiandrosterone in relation to androstenedione or cortisol was increased. Indicative of aromatase activation, estrone and 17 beta-estradiol demonstrated a marked increase during the attack phase. Conclusion: This study suggests that some important steroid hormone-conversion steps are activated (aromatase) and inhibited (second step of the P450c17 and the 3 beta-hydroxysteroid dehydrogenase) during the inflammatory attack phase in a TRAPS patient. These changes of enzyme pathways are typical on the basis of increased TNF signaling

Control of the Ferric Citrate Transport System of Escherichia coli: Mutations in Region 2.1 of the FecI Extracytoplasmic-Function Sigma Factor Suppress Mutations in the FecR Transmembrane Regulatory Protein

Transcription of the ferric citrate transport genes is initiated by binding of ferric citrate to the FecA protein in the outer membrane of Escherichia coli K-12. Bound ferric citrate does not have to be transported but initiates a signal that is transmitted by FecA across the outer membrane and by FecR across the cytoplasmic membrane into the cytoplasm, where the FecI extracytoplasmic-function (ECF) sigma factor becomes active. In this study, we isolated transcription initiation-negative missense mutants in the cytoplasmic region of FecR that were located at four sites, L13Q, W19R, W39R, and W50R, which are highly conserved in FecR-like open reading frames of the Pseudomonas aeruginosa, Pseudomonas putida, Bordetella pertussis, Bordetella bronchiseptica, and Caulobacter crescentus genomes. The cytoplasmic portion of the FecR mutant proteins, FecR(1–85), did not interact with wild-type FecI, in contrast to wild-type FecR(1–85), which induced FecI-mediated fecB transport gene transcription. Two missense mutations in region 2.1 of FecI, S15A and H20E, partially restored induction of ferric citrate transport gene induction of the fecR mutants by ferric citrate. Region 2.1 of ς(70) is thought to bind RNA polymerase core enzyme; the residual activity of mutated FecI in the absence of FecR, however, was not higher than that of wild-type FecI. In addition, missense mutations in the fecI promoter region resulted in a twofold increased transcription in fecR wild-type cells and a partial restoration of fec transport gene transcription in the fecR mutants. The mutations reduced binding of the Fe(2+) Fur repressor and as a consequence enhanced fecI transcription. The data reveal properties of the FecI ECF factor distinct from those of ς(70) and further support the novel transcription initiation model in which the cytoplasmic portion of FecR is important for FecI activity