Bone marrow sinusoidal endothelial cells are a site of Fgf23 upregulation in a mouse model of iron deficiency anemia.

Iron deficiency is a potent stimulator of fibroblast growth factor 23 (FGF23), a hormonal regulator of phosphate and vitamin D metabolism, that is classically thought to be produced by bone-embedded osteocytes. Here, we show that iron-deficient transmembrane serine protease 6 knockout (Tmprss6-/-) mice exhibit elevated circulating FGF23 and Fgf23 messenger RNA (mRNA) upregulation in the bone marrow (BM) but not the cortical bone. To clarify sites of Fgf23 promoter activity in Tmprss6-/- mice, we introduced a heterozygous enhanced green fluorescent protein (eGFP) reporter allele at the endogenous Fgf23 locus.

Hepatocellular Adenoma: Report of 2 Cases That Highlight the Relevance of Phenotype-Genotype Correlation in the Pediatric Population.

Background: Hepatocellular adenoma (HCA) in the pediatric population is very rare and there are only limited studies, especially with molecular characterization of the tumors. Main HCA subtypes recognized in the current WHO classification include -inactivated HCA (H-HCA), inflammatory HCA (IHCA), β-catenin-activated HCA (b-HCA), and β-catenin-activated IHCA (b-IHCA) and sonic hedgehog HCA (shHCA) is reported as an emerging subtype.

Methods: Clinical history, pathological information, and molecular studies for a series of 2 cases of pediatric HCA were reviewed.