👤 Hideki Tohda

Cholesterol efflux capacity (CEC) is robust biomarker for atherosclerotic cardiovascular disease (ASCVD). However, cell-based CEC assays require complex procedures that limit clinical use. The immobilized liposome-bound gel beads (ILG) method, a newly developed cell-free CEC assay, demonstrates sufficient performance for clinical application. This study investigated the clinical significance of CEC measured by the ILG method in relation to HDL subclasses and coronary artery plaque characteristics. We analyzed CEC and HDL parameters, including the ratio of apolipoprotein E (apoE)-HDL-C to HDL-C (%apoE) and HDL CEC correlated positively with HDL-C and %apoE. Among the patients, 26 (42.6%) exhibited large lipid-rich plaques on OCT. Univariable analysis showed that CEC was significantly lower in patients with large lipid-rich plaques compared to those without. While this association did not reach statistical significance after multivariable adjustment (p = 0.109), the addition of CEC to traditional risk factors improved the model's explanatory power (Nagelkerke R CEC measured using the ILG method reflects HDL subclass features and is associated with the burden of lipid-rich coronary artery plaques. These findings suggest the significance of CEC evaluated using the ILG method, supporting its potential for enhanced ASCVD risk assessment and further clinical applications. Show less

Calcineurin is an important mediator that connects the Ca(2+)-dependent signaling to various cellular responses in a wide variety of cell types and organisms. In budding yeast, activated calcineurin exerts its function mainly by regulating the Crz1p/Tcn1 transcription factor. Here, we cloned the fission yeast prz1(+) gene, which encodes a zinc finger transcription factor highly homologous to Crz1/Tcn1. Similar to the results in budding yeast, calcineurin dephosphorylated Prz1 and resulted in the trans-location of Prz1 from the cytoplasm to the nucleus. Prz1 expression was stimulated by high extracellular Ca(2+) in a calcineurin-dependent fashion. However, unlike in budding yeast, the prz1-null cells did not show any phenotype similar to those previously reported in calcineurin deletion such as aberrant cell morphology, mating defect, or hypersensitivity to Cl(-). Instead, the prz1-null cells showed hypersensitivity to Ca(2+), consistent with a dramatic decrease in transcription of Pmc1 Ca(2+) pump. Interestingly, overexpression of Prz1 did not suppress the Cl(-) hypersensitivity of calcineurin deletion, and overexpression of Pmp1 MAPK phosphatase suppressed the Cl(-) hypersensitivity of calcineurin deletion but not the Ca(2+) hypersensitivity of prz1 deletion. In addition, mutations in the its2(+)/cps1(+), its8(+), and its10(+)/cdc7(+) genes that showed synthetic lethal genetic interaction with calcineurin deletion did not exhibit synthetic lethality with the prz1 deletion. Our results suggest that calcineurin activates at least two distinct signaling branches, i.e. the Prz1-dependent transcriptional regulation and an unknown mechanism, which functions antagonistically with the Pmk1 MAPK pathway. Show less