detection-fluorescent-nanoparticle-interactions-with-primary-immune

Detection of Fluorescent Nanoparticle Interactions with Primary Immune Cell Subpopulations by Flow Cytometry

Engineered nanoparticles are endowed with very promising properties for therapeutic and diagnostic purposes. This work describes a fast and reliable ...

Istituto Italiano di Tecnologia

Obesity is a chronic low inflammatory state. In the obesity condition the white adipose tissue (WAT) is massively infiltrated with monocytes/macrophages, and the nature of the signals recruiting these inflammatory cells has yet to be fully elucidated. Haptoglobin (Hp) is an inflammatory marker and its expression is induced in the WAT of obese subjects. In an effort to elucidate the biological significance of Hp presence in the WAT and of its upregulation in obesity we formulated the hypothesis that Hp may serve as a macrophage chemoattractant.

The obesity and inflammatory marker haptoglobin attracts monocytes via interaction with chemokine (C-C motif) receptor 2 (CCR2).

Haptoglobin (Hp) is upregulated in both inflammation and obesity. The low chronic inflammatory state, caused by massive adipose tissue macrophage (ATM) infiltration found in obesity, and low adiponectin have been implicated in the development of insulin resistance and hepatosteatosis. The aim of this work was to investigate whether and how Hp interferes with the onset of obesity-associated complications.

Obesity-associated hepatosteatosis and impairment of glucose homeostasis are attenuated by haptoglobin deficiency.

Haptoglobin (Hp) is an inflammatory and adiposity marker, its expression during obesity being specifically induced in the white adipose tissue (WAT). We previously reported that when challenged with a high fat diet (HFD) Hp(-/-) mice are partially protected from the onset of insulin resistance and hepatosteatosis. The aim of the present study was to get further insights into Hp function in WAT. To this end, we performed histological and gene expression analysis of the Hp(-/-) WAT, both in standard and obesity conditions, and investigated how Hp deficiency impacts adipogenesis and WAT development. The average size and percentage of very large adipocytes were respectively smaller and reduced in HFD Hp(-/-) mice as compared with HFD WT. The expression of perilipin, HSL and angiogenesis related markers were increased in HFD Hp(-/-) mice. Lean adult Hp(-/-) showed significantly larger adipocytes and lower subcutaneous WAT expression of aP2 and LPL with respect to WT. Hp(-/-) young mice (P30) were characterized by larger adipocyte size and lower expression of adipocyte and adipogenesis markers. Comparison of adipocyte size distribution between young and adult mice revealed attenuated changes in Hp(-/-) mice compared with WT. Mouse embryonic fibroblasts from Hp(-/-) mice were less capable of accumulating triglycerides and exhibited lower expression of PPARγ, aP2, FAS, LPL and Leptin. In conclusion, Hp deficiency tends to blunt the effect of age and diet on the size of adipocytes, which show less susceptibility to develop hypertrophy during obesity and a reduced adipogenic/hyperplastic potential during youth. In addition, Hp deficiency impacts negatively on adipogenesis.

Article	Year
The obesity and inflammatory marker haptoglobin attracts monocytes via interaction with chemokine (C-C motif) receptor 2 (CCR2). BMC biology\| PubMed ID: 20017911	2009
Obesity-associated hepatosteatosis and impairment of glucose homeostasis are attenuated by haptoglobin deficiency. Diabetes\| PubMed ID: 21873550	2011
Haptoglobin deficiency determines changes in adipocyte size and adipogenesis. Adipocyte\| PubMed ID: 23700523	2012

Olimpia Gamucci

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