Rapid detection of dysfunctional high-density lipoproteins using isoelectric focusing-based microfluidic device to...

Recently, we reported elevated levels of advanced glycated end products (AGEs) in human high-density lipoproteins (HDL), with fragmentation of apoA-I in an elderly group, compared with a younger group. More dysfunctional HDL from human plasma was demonstrated in the elderly group, including reconstituted HDL containing glycated apoA-I (gA-I-rHDL) with elevation of AGEs. Based on SDS-PAGE analysis, HDL(3) from the elderly group (E-HDL(3)) exhibited increased multimerization with increased smear band intensity compared to HDL(3) from the younger group (Y-HDL(3)). According to isoelectric focusing gel analysis, gA-I-rHDL and E-HDL(3) showed electromobility to the basic region of pH with a broader band range. In a microfluidic channel, E-HDL(3) had faster mobility with a broader range and a higher isoelectric point (pI, approximately 8.1), whereas Y-HDL(3) showed a narrow band range with a lower pI (approximately 6.9). In conclusion, gA-I-rHDL and E-HDL share several electrophoretic properties with multimerization and faster mobility in microfluidic channels, depending on the isoelectric point. These results can be applied to develop a rapid detection system for modified HDL to predict the extent of aging and aging-related metabolic diseases, such as cardiovascular disease and diabetes.