Acquisition of Interleukin-6 Production Ability Over Time With Pheochromocytoma.

Pheochromocytoma is a tumor of chromaffin cells causing catecholamines overproduction. Interleukin-6 (IL-6), a cytokine, is central to inflammation and immunity. Few studies have reported IL-6-producing pheochromocytoma whose underlying mechanism has not been elucidated. Herein, we present a case of pheochromocytoma whose clinical manifestations changed, and IL-6 levels elevated over time. A 48-year-old woman was referred to our hospital for fever and hepatic dysfunction. Six years prior, a right adrenal tumor was detected during the examination for ovarian teratoma without C-reactive protein (CRP) elevation. Several imaging studies at our hospital showed no abnormalities except for an increase in the size of the adrenal tumor and hepatomegaly. In addition, antibiotics did not improve the fever. Laboratory tests showed elevated levels of CRP with IL-6 elevation. An enlarged adrenal tumor was detected. Administering doxazosin lowered the CRP and IL-6 levels, then IL-6-producing pheochromocytoma was suspected, and adrenalectomy was performed. After surgery, fever and hepatic function were improved, and the CRP and IL-6 levels were normalized. Immunostaining of the resected tissue showed IL-6 focal positivity, which meant the phenotype of tumor cells focally changed their phenotypes over time. IL-6-producing pheochromocytoma should be considered in patients with adrenal tumors and fever of unknown origin.

Plant-Specific Domains and Fragmented Sequences Imply Non-Canonical Functions in Plant Aminoacyl-tRNA Synthetases.

Aminoacyl-tRNA synthetases (aaRSs) play essential roles in protein translation. In addition, numerous aaRSs (mostly in vertebrates) have also been discovered to possess a range of non-canonical functions. Very few studies have been conducted to elucidate or characterize non-canonical functions of plant aaRSs. A genome-wide search for aaRS genes in Arabidopsis thaliana revealed a total of 59 aaRS genes. Among them, asparaginyl-tRNA synthetase (AsnRS) was found to possess a WHEP domain inserted into the catalytic domain in a plant-specific manner. This insertion was observed only in the cytosolic isoform. In addition, a long stretch of sequence that exhibited weak homology with histidine ammonia lyase (HAL) was found at the N-terminus of histidyl-tRNA synthetase (HisRS). This HAL-like domain has only been seen in plant HisRS, and only in cytosolic isoforms. Additionally, a number of genes lacking minor or major portions of the full-length aaRS sequence were found. These genes encode 14 aaRS fragments that lack key active site sequences and are likely catalytically null. These identified genes that encode plant-specific additional domains or aaRS fragment sequences are candidates for aaRSs possessing non-canonical functions.