In a recent publication, Mennesson E. et al. have developped a smart approach to perform both adipokine protein and miRNA profilings in in vitro adipocyte models mimicking the physiological state of adipose tissues. Adipokines and miRNAs are now known to be involved in adipose tissue metabolism in obesity during which hypoxic adipose tissue development is seen due to tissue mass expansion. Such Cytokine and miRNA profilings are thus needed to better decipher the physiopathology of obesity and to identify new biomarkers.
For this study, Human mature adipocytes were obtained from subcutaneous preadipocytes (derived from adipose tissue of six donors (Zen-Bio/tebu-bio). Mature adipocytes were cultured either under hypoxia conditions (1% O2 for 3 days by using an INVIVO2 400 workstation (Ruskinn Technology Ltd in tebu-bio laboratories)) or in a standard incubator (21% O2) as normoxic culture conditions. For hypoxic conditions, all media used in the workstation were preconditioned using HypoxyCOOL (Ruskinn Technology Ltd at tebu-bio premises) to reduce oxygen concentration to 1%.
Cytokine secretion was assayed from collected conditioned media with a pre-designed Raybiotech/tebu-bio obesity adipokine antibody array while miRNA secretion was performed with 3D-Gene® Human miRNA microarray.
By comparing expression profiles obtained under normoxic vs. hypoxic conditions, the authors showed that hypoxia up-regulated the secretion of leptin, OPG, PAI-1, VEGF and down-regulated the secretion of adiponectin. Interestingly, the fold change levels were donor-dependent but without clear connection to BMI. miRNA profiling showed interesting differences for miR-1298, miR-3679-5p, miR-4648, miR-4672, miR-4725-3p, miR-6722-5p or miR-6723-5p. These miRNAs might potentially be new biomarkers for hypoxia in obesity studies.
The results of this study, presented during the 4th Munich Biomarker conference (November 25th-26th, 2014), are available online. I also suggest this extra information about the 3D-Gene technology for miRNA profiling if you want to know more about this new miRNA-related biomarker discovery tool.