MiR-4261 targeted YWHAE/CAST/GPX1 impairs the calcium regulatory function of PMCA4 in erythrocytes of myeloma.

OBJECTIVE

Calcium is an important substance to maintain the normal life activities of erythrocytes, and calcium overload has a damaging effect on erythrocytes. Multiple myeloma (MM) has a strong role in secreting microRNA (miRNA), but whether the miRNA produced by MM can affect the calcium regulation function of erythrocytes needs to be further studied.

MATERIALS AND

METHODS

The intracellular calcium content was detected by atomic absorption spectroscopy (AAS). The oxidative stress level of cells was assessed by the determination of ROS/H 2 O 2 /GSH content of erythrocytes and the detection of antioxidant capacity. QRT-PCR and Western Blot were used to determine the expression of gene and protein. The binding relationship between miR-4261 and target genes was determined by a dual-luciferase gene reporter assay. Targeted drugs detect the effects of plasma membrane Ca 2+ -ATPase 4 (PMCA4) and calpain-1 on calcium regulation in erythrocytes.

RESULTS

This study found that erythrocytes in MM had calcium overload and high levels of oxidative stress, which were associated with reduced plasma membrane Ca2+-ATPase4 (PMCA4) expression in erythrocytes. Expression of 14-3-3ε (Gene: YWHAE)/calpastatin (Gene: CAST)/glutathione peroxidase-1 (Gene: GPX1), which affected PMCA4 function, was also reduced. After database screening and in vitro studies, it was found that miR-4261 is the only miRNA in MM that can simultaneously downregulate the expression of 14-3-3ε/calpastatin/GPX1.

CONCLUSION

MiR-4261 can target down-regulation of 14-3-3ε/calpastatin/GPX1 to affect erythrocyte PMCA4, resulting in erythrocyte calcium overload and peroxidative damage. MiR-4261 may serve as one of the potential markers to measure erythrocyte damage in MM.