casein-kinase-ii and Pheochromocytoma

Multiple symmetric lipomatosis (MSL) is a rare disorder characterized by overgrowing lipomatous tissue (LT) in the subcutaneous adipose tissue (SAT). What LT is and how it expands are not completely understood; previous data suggested that it could derive from brown AT precursors. In six MSL type I patients, we compared LT morphology by histological and immunohistochemistry (IHC) analysis, gene expression, by qPCR, kinase activity, by Western Blot and in vitro assay to paired-control SAT using AT from patients with pheochromocytoma as a human browning reference. In the stromal vascular fraction (SVF), we quantified adipose stem cells (ASCs) by flow cytometry, the proliferation rate, white and beige adipogenic potential and clonogenicity and adipogenicity by a limiting dilution assay. LT displayed white AT morphology and expression pattern and did not show increased levels of the brown-specific marker UCP1. In LT, we evidenced AKT, CK2 and ERK1/2 hyperactivation. LT-SVF contained increased ASCs, proliferated faster, sprouted clones and differentiated into adipocytes better than the control, displaying enhanced white adipogenic potential but not increased browning compared to SAT. In conclusion, LT is a white AT depot expanding by hyperplasia through increased stemness and enhanced white adipogenesis upregulating AKT, CK2 and ERK1/2, which could represent new targets to counteract MSL.

Topics: Adipose Tissue, White; Adrenal Gland Neoplasms; Aged; Case-Control Studies; Casein Kinase II; Cell Differentiation; Cell Proliferation; Extracellular Signal-Regulated MAP Kinases; Female; Gene Expression Profiling; Humans; Lipomatosis, Multiple Symmetrical; Male; Middle Aged; Pheochromocytoma; Proto-Oncogene Proteins c-akt; Stem Cells; Up-Regulation

The rat norepinephrine transporter (rNET) cDNA from the PC12 pheochromocytoma cell line has been cloned by RT-PCR and characterized. The cDNA encodes an integral membrane protein consisting of 617 amino acids which contains twelve putative transmembrane domains, two potential N-glycosylation sites, two potential phosphorylation sites for protein kinase C and one phosphorylation site for casein kinase II. The nucleotide and deduced amino acid sequence shows a high level of homology to the human and the bovine norepinephrine transporter and less homology to the rat dopamine transporter (rDAT). Heterologous expression of rNET in HEK293 cells revealed that uptake of [3H]norepinephrine is sodium- and chloride-dependent and highly sensitive to the selective norepinephrine transporter inhibitors desipramine and nisoxetine. The cloned rNET cDNA provides the opportunity to investigate this transporter in heterologous expression systems and adds a new member to the family of sodium- and chloride-dependent neurotransmitter transporters.

Topics: Adrenal Gland Neoplasms; Algorithms; Amino Acid Sequence; Animals; Carrier Proteins; Casein Kinase II; Cattle; Cloning, Molecular; Glycosylation; Humans; Models, Molecular; Molecular Sequence Data; Norepinephrine; Norepinephrine Plasma Membrane Transport Proteins; PC12 Cells; Pheochromocytoma; Phosphorylation; Protein Kinase C; Protein Serine-Threonine Kinases; Protein Structure, Secondary; Rats; Recombinant Proteins; Sequence Alignment; Sequence Homology, Amino Acid; Symporters; Transfection