Menaquinone‑4 modulates the expression levels of calcification‑associated factors to inhibit calcification of rat aortic vascular smooth muscle cells in a dose‑dependent manner

Abstract

Vascular calcification (VC) caused by chronic kidney disease (CKD)-mineral and bone disorder is a common complication of CKD. Recent studies have demonstrated that menaquinone-4 (MK-4) is negativly associated with VC in patients with CKD. Furthermore, we have previously shown that runt-related transcription factor 2 (Runx2) is important in the phenotypic transformation process of rat vascular smooth muscle cells (VSMCs), which is the key step for the development of VC. The present study investigated the influence of MK-4 on the phenotypic transformation process of rat VSMCs in order to illustrate its role in the process of VC. Calcification assays were perfomed to access the calcified degree of rat VSMCs. Additionally, the genes and proteins related to phenotypic transformation were measured by reverse transcription-polymerase chain reaction and western blotting methods. It was revealed that calcium deposition in the cells was evidently increased with an addition of β-glycerophosphate (β-GP) and could be completely prevented by co-incubation with MK-4 in a dose-dependent manner. Furthermore, the expression of Runx2 in the β-GP-induced VSMCs was inhibited by MK-4. It was also revealed that the expression of SMAD1 and bone morphogenetic protein (BMP)-2 were decreased in the β-GP-induced VSMCs treated with MK-4 in a dose-dependent manner; however, the expression of SMAD7 was increased in the β-GP-induced VSMCs treated with MK-4 in a dose-dependent manner. These observations suggest that MK-4 reduces mineralization by regulating the BMP-2 signaling pathway in order to attenuate the expression of Runx2.

Combining phosphate binder therapy with vitamin K2 inhibits vascular calcification in an experimental animal model of kidney failure

“…The inhibitory role of combined PB and vitamin K2 can be explained via a mechanism other than MGP activation. It has been shown that vitamin K protects VSMC differentiation and calcification into an osteogenic phenotype under a high phosphate environment via downregulation of bone-specific genes [37,38]. However, we could not find such an effect in our study (data not shown).…”

Roles of Nuclear Receptors in Vascular Calcification

“…The latter is secreted by VSMCs and inhibits VC through poorly studied mechanisms [ 53 ]. These findings support a protective role for vitamin K in VC and this has been confirmed by numerous other studies [ 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 ].…”

Sevelamer Use, Vitamin K Levels, Vascular Calcifications, and Vertebral Fractures in Hemodialysis Patients: Results from the VIKI Study

“…Vitamin K2 has several different vitamers or menaquinones (MK), of which MK4-MK7 can exert important biologic actions. In-vitro, MK4 has been shown to act as an inhibitor of VC in vascular smooth muscle cells (VSMCs) (30,31). Furthermore, in HD patients, Fusaro et al showed that MK4 deficiency emerged as a significant predictor of aortic calcifications (24).…”