title: Free Radical-derived Oxysterols: Novel Adipokines Modulating Adipogenic Differentiation of Adipose Precursor Cells.
abstract: Increased oxidative stress in adipose tissue emerges as an inducer of obesity-linked insulin resistance. Here we tested whether free-radical derived oxysterols are formed by, and accumulate in, human adipocytes. Moreover, we asked whether increased accumulation of oxysterols characterizes the adipose cells of obese patients with type 2 diabetes (T2D) (OBT2D) compared with lean, nondiabetic controls (CTRLs). Finally, we studied the effects of the free radical-derived oxysterols on adipogenic differentiation of adipose-derived stem cells (ASCs).
  
  
  
  Adipocytes and ASCs were isolated from sc abdominal adipose tissue biopsy in four OBT2D and four CTRL subjects. Oxysterols in adipocytes were detected by gas chromatography/mass spectrometry. The cellular and molecular effects of oxysterols were then evaluated on primary cultures of ASCs focusing on cell viability, adipogenic differentiation, and "canonical" WNT and MAPK signaling pathways.
  
  
  
  7-ketocholesterol (7κ-C) and 7β-hydroxycholesterol were unambiguously detected in adipocytes, which showed higher oxysterol accumulation (P < .01) in OBT2D, as compared with CTRL individuals. Notably, the accumulation of oxysterols in adipocytes was predicted by the adipose cell size of the donor (R2= 0.582; P < .01). Challenging ASCs with free radical-derived type I (7κ-C) and type II (5,6-Secosterol) oxysterols led to a time- and concentration-dependent decrease of cell viability. Meaningfully, at a non-toxic concentration (1μM), these bioactive lipids hampered adipogenic differentiation of ASCs by sequential activation of WNT/β-catenin, p38-MAPK, ERK1/2, and JNK signaling pathways.
  
  
  
  Free radical-derived oxysterols accumulate in the "diabetic" fat and may act as novel adipokines modulating the adipogenic potential of undifferentiated adipose precursor cells.
authors.affiliation: Department of Internal Medicine (G.M.), Assisi Hospital, 06081 Assisi (Perugia), Italy; Department of Internal Medicine, Section of Internal Medicine, Endocrine and Metabolic Sciences (G.M., C.T.), University of Perugia, 06126 Perugia Italy; Department of Pharmaceutical Sciences (M.P., D.B., F.G.), University of Perugia, 06126 Perugia, Italy; Department of Anesthesiology and Intensive Care Medicine Mannheim (M.S.), Heidelberg University, 69117 Heidelberg, Germany; Department of Earth, Life and Environmental Sciences (F.L., B.C., S.P.), University Carlo Bo, 61029 Urbino, Italy; and Department of Medico-Surgical Sciences and Biotechnologies, Unit of Vascular Medicine (C.Z., L.I.), Sapienza University of Rome, 00185 Latina, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Murdolo
authors.affiliation: Department of Internal Medicine (G.M.), Assisi Hospital, 06081 Assisi (Perugia), Italy; Department of Internal Medicine, Section of Internal Medicine, Endocrine and Metabolic Sciences (G.M., C.T.), University of Perugia, 06126 Perugia Italy; Department of Pharmaceutical Sciences (M.P., D.B., F.G.), University of Perugia, 06126 Perugia, Italy; Department of Anesthesiology and Intensive Care Medicine Mannheim (M.S.), Heidelberg University, 69117 Heidelberg, Germany; Department of Earth, Life and Environmental Sciences (F.L., B.C., S.P.), University Carlo Bo, 61029 Urbino, Italy; and Department of Medico-Surgical Sciences and Biotechnologies, Unit of Vascular Medicine (C.Z., L.I.), Sapienza University of Rome, 00185 Latina, Italy.
authors.forename: Marta
authors.initials: M
authors.lastname: Piroddi
authors.affiliation: Department of Internal Medicine (G.M.), Assisi Hospital, 06081 Assisi (Perugia), Italy; Department of Internal Medicine, Section of Internal Medicine, Endocrine and Metabolic Sciences (G.M., C.T.), University of Perugia, 06126 Perugia Italy; Department of Pharmaceutical Sciences (M.P., D.B., F.G.), University of Perugia, 06126 Perugia, Italy; Department of Anesthesiology and Intensive Care Medicine Mannheim (M.S.), Heidelberg University, 69117 Heidelberg, Germany; Department of Earth, Life and Environmental Sciences (F.L., B.C., S.P.), University Carlo Bo, 61029 Urbino, Italy; and Department of Medico-Surgical Sciences and Biotechnologies, Unit of Vascular Medicine (C.Z., L.I.), Sapienza University of Rome, 00185 Latina, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Tortoioli
authors.affiliation: Department of Internal Medicine (G.M.), Assisi Hospital, 06081 Assisi (Perugia), Italy; Department of Internal Medicine, Section of Internal Medicine, Endocrine and Metabolic Sciences (G.M., C.T.), University of Perugia, 06126 Perugia Italy; Department of Pharmaceutical Sciences (M.P., D.B., F.G.), University of Perugia, 06126 Perugia, Italy; Department of Anesthesiology and Intensive Care Medicine Mannheim (M.S.), Heidelberg University, 69117 Heidelberg, Germany; Department of Earth, Life and Environmental Sciences (F.L., B.C., S.P.), University Carlo Bo, 61029 Urbino, Italy; and Department of Medico-Surgical Sciences and Biotechnologies, Unit of Vascular Medicine (C.Z., L.I.), Sapienza University of Rome, 00185 Latina, Italy.
authors.forename: Desirée
authors.initials: D
authors.lastname: Bartolini
authors.affiliation: Department of Internal Medicine (G.M.), Assisi Hospital, 06081 Assisi (Perugia), Italy; Department of Internal Medicine, Section of Internal Medicine, Endocrine and Metabolic Sciences (G.M., C.T.), University of Perugia, 06126 Perugia Italy; Department of Pharmaceutical Sciences (M.P., D.B., F.G.), University of Perugia, 06126 Perugia, Italy; Department of Anesthesiology and Intensive Care Medicine Mannheim (M.S.), Heidelberg University, 69117 Heidelberg, Germany; Department of Earth, Life and Environmental Sciences (F.L., B.C., S.P.), University Carlo Bo, 61029 Urbino, Italy; and Department of Medico-Surgical Sciences and Biotechnologies, Unit of Vascular Medicine (C.Z., L.I.), Sapienza University of Rome, 00185 Latina, Italy.
authors.forename: Martin
authors.initials: M
authors.lastname: Schmelz
authors.affiliation: Department of Internal Medicine (G.M.), Assisi Hospital, 06081 Assisi (Perugia), Italy; Department of Internal Medicine, Section of Internal Medicine, Endocrine and Metabolic Sciences (G.M., C.T.), University of Perugia, 06126 Perugia Italy; Department of Pharmaceutical Sciences (M.P., D.B., F.G.), University of Perugia, 06126 Perugia, Italy; Department of Anesthesiology and Intensive Care Medicine Mannheim (M.S.), Heidelberg University, 69117 Heidelberg, Germany; Department of Earth, Life and Environmental Sciences (F.L., B.C., S.P.), University Carlo Bo, 61029 Urbino, Italy; and Department of Medico-Surgical Sciences and Biotechnologies, Unit of Vascular Medicine (C.Z., L.I.), Sapienza University of Rome, 00185 Latina, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Luchetti
authors.affiliation: Department of Internal Medicine (G.M.), Assisi Hospital, 06081 Assisi (Perugia), Italy; Department of Internal Medicine, Section of Internal Medicine, Endocrine and Metabolic Sciences (G.M., C.T.), University of Perugia, 06126 Perugia Italy; Department of Pharmaceutical Sciences (M.P., D.B., F.G.), University of Perugia, 06126 Perugia, Italy; Department of Anesthesiology and Intensive Care Medicine Mannheim (M.S.), Heidelberg University, 69117 Heidelberg, Germany; Department of Earth, Life and Environmental Sciences (F.L., B.C., S.P.), University Carlo Bo, 61029 Urbino, Italy; and Department of Medico-Surgical Sciences and Biotechnologies, Unit of Vascular Medicine (C.Z., L.I.), Sapienza University of Rome, 00185 Latina, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Canonico
authors.affiliation: Department of Internal Medicine (G.M.), Assisi Hospital, 06081 Assisi (Perugia), Italy; Department of Internal Medicine, Section of Internal Medicine, Endocrine and Metabolic Sciences (G.M., C.T.), University of Perugia, 06126 Perugia Italy; Department of Pharmaceutical Sciences (M.P., D.B., F.G.), University of Perugia, 06126 Perugia, Italy; Department of Anesthesiology and Intensive Care Medicine Mannheim (M.S.), Heidelberg University, 69117 Heidelberg, Germany; Department of Earth, Life and Environmental Sciences (F.L., B.C., S.P.), University Carlo Bo, 61029 Urbino, Italy; and Department of Medico-Surgical Sciences and Biotechnologies, Unit of Vascular Medicine (C.Z., L.I.), Sapienza University of Rome, 00185 Latina, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Papa
authors.affiliation: Department of Internal Medicine (G.M.), Assisi Hospital, 06081 Assisi (Perugia), Italy; Department of Internal Medicine, Section of Internal Medicine, Endocrine and Metabolic Sciences (G.M., C.T.), University of Perugia, 06126 Perugia Italy; Department of Pharmaceutical Sciences (M.P., D.B., F.G.), University of Perugia, 06126 Perugia, Italy; Department of Anesthesiology and Intensive Care Medicine Mannheim (M.S.), Heidelberg University, 69117 Heidelberg, Germany; Department of Earth, Life and Environmental Sciences (F.L., B.C., S.P.), University Carlo Bo, 61029 Urbino, Italy; and Department of Medico-Surgical Sciences and Biotechnologies, Unit of Vascular Medicine (C.Z., L.I.), Sapienza University of Rome, 00185 Latina, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Zerbinati
authors.affiliation: Department of Internal Medicine (G.M.), Assisi Hospital, 06081 Assisi (Perugia), Italy; Department of Internal Medicine, Section of Internal Medicine, Endocrine and Metabolic Sciences (G.M., C.T.), University of Perugia, 06126 Perugia Italy; Department of Pharmaceutical Sciences (M.P., D.B., F.G.), University of Perugia, 06126 Perugia, Italy; Department of Anesthesiology and Intensive Care Medicine Mannheim (M.S.), Heidelberg University, 69117 Heidelberg, Germany; Department of Earth, Life and Environmental Sciences (F.L., B.C., S.P.), University Carlo Bo, 61029 Urbino, Italy; and Department of Medico-Surgical Sciences and Biotechnologies, Unit of Vascular Medicine (C.Z., L.I.), Sapienza University of Rome, 00185 Latina, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Iuliano
authors.affiliation: Department of Internal Medicine (G.M.), Assisi Hospital, 06081 Assisi (Perugia), Italy; Department of Internal Medicine, Section of Internal Medicine, Endocrine and Metabolic Sciences (G.M., C.T.), University of Perugia, 06126 Perugia Italy; Department of Pharmaceutical Sciences (M.P., D.B., F.G.), University of Perugia, 06126 Perugia, Italy; Department of Anesthesiology and Intensive Care Medicine Mannheim (M.S.), Heidelberg University, 69117 Heidelberg, Germany; Department of Earth, Life and Environmental Sciences (F.L., B.C., S.P.), University Carlo Bo, 61029 Urbino, Italy; and Department of Medico-Surgical Sciences and Biotechnologies, Unit of Vascular Medicine (C.Z., L.I.), Sapienza University of Rome, 00185 Latina, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Galli
mesh_terms: D017667:Adipocytes / Q000378:metabolism*; D050156:Adipogenesis; D054392:Adipokines / Q000378:metabolism*; D000273:Adipose Tissue / Q000378:metabolism*; D000328:Adult; D002478:Cells, Cultured; D015897:Comorbidity; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology / Q000378:metabolism*; D005260:Female; D005609:Free Radicals / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology / Q000378:metabolism*; D000072376:Oxysterols / Q000378:metabolism*; D013234:Stem Cells / Q000378:metabolism
chemical_list: D054392:Adipokines; D005609:Free Radicals; D000072376:Oxysterols