PCSK9-related LDL-C value is correlated to Rab5 isoform expression level

Abstract

Circulating LDL metabolism is mostly related to the LDL internalization and intracellular lysosome-related degradation events. In this way, the competitive biologic agents and vesicular membrane-integrated or assembled proteins are important functioning factors. The aim of this study was to investigate the relationships between Rab5, Rab7, Lamp1 and Lamp2 gene expression levels, circulating PCSK9 value and, serum LDL-C level. One hundred ten subjects were recruited from healthy adults. Lipid profile was measured by laboratory routine techniques. PCSK9 value was measured with ELISA Kit. The Rab5, Rab7, Lamp1 and Lamp2 gene expression levels of buffy coat samples were measured using Real-Time qPCR technique. Serum LDL-C level was correlated to Rab5 expression level (r 0.25, p 0.02) and circulating PCSK9 value (r 0.3, p 0.003). Although PCSK9 elevated positively with LDL-C value but the Rab5 expression level increased up to 75centiles. Furthermore, multiple regression analyses showed that the Rab5 expression level is significantly correlated to LDL-C value (p 0.025, β 0.003), age (p 0.037, β −0.006) and Lamp1 expression (p 0.001, β 0.079) while the Rab7 expression level did not relate to the study factors except for Lamp1 (p 0.011, β 0.053). The results proposed that the LDL-C-correlated Rab5 expression level may be a primary cellular response due to reduced PCSK9-associated LDL influx. Furthermore, the LDL-C value was not correlated to Lamp1 and Rab7 expression levels. Our data suggested that the vesicular structures may be reduced with age.