The metabolic syndrome is defined as a clustering of various diseases, including diabetes, heart disease, and hypertension, in an individual. Since metabolic syndrome is typically observed in obese individuals, the roles that adipocytes, or fat cells, play in the etiology of these diseases has begun to be investigated. New research in this area has found that adipocytes secrete over twenty proteins ranging from traditional cytokines including tumor necrosis factor a to proteins regulating satiety such as leptin.
In the Roper laboratory, we develop analytical methods to study the various roles and methods of regulation of adipocytes and the proteins secreted from these cells. For many of our experiments, we use microfluidic devices as platforms for performing our analyses. Microfluidic chips are planar substrates in which channels and various reaction venues can be placed in a highly integrated manner allowing several advantages over more conventional experimental designs. For example, in the figure below two channels are intersecting with little dead volume. This arrangement allows low abundant analytes to be transported through the device with little dilution allowing facile detection.
One project will be to monitor multiple secretory proteins from adipocytes, and at specific times, lyse the cells and measure intracellular metabolites. These experiments will be performed within a microfluidic device and will utilize a variety of separation, optical, and mass spectrometric techniques. Shown in the figure below is a group of cells within a microfluidic structure where the channel shown by the arrow was used to sample peptide secretion; by using a competitive immunoassay, a 30 s temporal resolution and a 1 nM limit of detection was achieved.
Two other projects will include infrared-mediated PCR for the production of aptamers on a microfluidic device and measurement of transcription factors in cells by new affinity separation methods.
