16 research outputs found

    Interaction of osteopontin with IL-18 in obese individuals: implications for insulin resistance.

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    BACKGROUND/OBJECTIVE: Osteopontin (OPN) and IL-18 are known inflammatory mediators and both participate in a wide range of biological processes linked to immunological disorders. Since an interaction between OPN and IL-18 has not been studied in obesity, we investigated whether: (i) their levels were simultaneously elevated in obese individuals; (ii) OPN was associated with IL-18 in obese individuals and (iii) their levels associated with fasting blood glucose (FBG) and BMI. SUBJECTS AND METHODS: PBMCs and plasma samples were isolated from 60 individuals including lean as well as overweight and obese individuals. Subcutaneous adipose tissue samples were obtained. OPN and IL-18 were measured by ELISA. OPN and IL-18 mRNA expression was quantified by real time quantitative RT-PCR. RESULTS: Obese individuals exhibited significantly increased circulating OPN levels as compared with lean individuals (obese 2865±101; lean 1681±116 pg/ml; P<0.0001). IL-18 levels were also high in obese individuals (obese 491±39, lean 301±26 pg/ml; P = 0.0009). OPN and IL-18 expression were simultaneously up-regulated (OPN: 5.4-Fold; IL-18: 8.9-Fold; P<0.05) in PBMCs from obese individuals compared to lean group. Adipose tissue from obese individuals had high expression of OPN (7.3-Fold) and IL-18 (9.6-Fold). Plasma OPN levels correlated positively with FBG levels (r = 0.32, P = 0.02). Similarly, IL-18 correlated positively with FBG levels (r = 0.406, P = 0.0042). Stepwise multiple regression analysis showed an independent association of BMI with OPN and IL-18. Interestingly, OPN levels increased progressively with an increase in IL-18 levels (r = 0.52, P = 0.0004). We also examined the regulatory role of IL-18 in OPN secretion from PBMCs. Neutralizing anti-IL-18Rα mAb reduced OPN secretion. CONCLUSION: These findings represent the first observation that plasma, PBMC and adipose tissue OPN and IL-18 are simultaneously increased and correlate with each other in overweight/obese individuals which may trigger the development of obesity-associated insulin resistance. Moreover, these results provide the direct evidence that IL-18 regulates OPN production in PBMCs

    Quality of Cell Products: Authenticity, Identity, Genomic Stability and Status of Differentiation

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    Cellular therapies that either use modifications of a patient's own cells or allogeneic cell lines are becoming in vogue. Besides the technical issues of optimal isolation, cultivation and modification, quality control of the generated cellular products are increasingly being considered to be more important. This is not only relevant for the cell's therapeutic application but also for cell science in general. Recent changes in editorial policies of respected journals, which now require proof of authenticity when cell lines are used, demonstrate that the subject of the present paper is not a virtual problem at all. In this article we provide 2 examples of contaminated cell lines followed by a review of the recent developments used to verify cell lines, stem cells and modifications of autologous cells. With relative simple techniques one can now prove the authenticity and the quality of the cellular material of interest and therefore improve the scientific basis for the development of cells for therapeutic applications. The future of advanced cellular therapies will require production and characterization of cells under GMP and GLP conditions, which include proof of identity, safety and functionality and absence of contamination

    Expression of OPN and IL-18 mRNA in adipose tissue.

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    <p>Adipose tissue samples from 9 (lean: 3, overweight: 3 and obese: 3) individuals with different BMI were subjected to total RNA isolation. OPN and IL-18 mRNA expression was determined by real time quantitative RT-PCR. Relative mRNA expression was expressed as fold expression over average of gene expression of lean group. The expression level in lean group was assumed to be 1. Values are presented as mean ± SE (A and B).</p

    Plasma levels of OPN and IL-18 in obese individuals.

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    <p>60 plasma samples from obese (n: 24), overweight (n: 20) and lean individuals (n: 16) were analyzed for expression of the circulating OPN (A) and IL-18 (B). Each dot represents the individual value of OPN and IL-18. Lines represented the mean values of plasma OPN and IL-18 of each group with ± SE.</p

    OPN is expressed by PBMCs and its secretion is induced by rhIL-18.

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    <p>PBMCs were treated with and without rhIL-18 (20 ng/ml) in the presence or absence of anti IL-18Rα neutralizing monoclonal antibody (0.1 ug/ml), and isotype control antibody IgG1 (0.1 ug/ml). Cells were treated as indicated for 16 hours. PBMCs and culture supernatants were harvested. Total RNA was isolated and OPN gene expression was determined by real time quantitative RT-PCR. Relative mRNA expression was expressed as fold expression over average of gene expression of controls. The average expression level in controls was assumed to be 1. Values are presented as mean ± SE (A). Secreted OPN protein was determined in the culture supernatants by ELISA (B). Data were shown from three independent experiments, each performed with PBMCs derived from three different healthy donors.</p
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