Functional Cooperation between Vitamin D Receptor and Runx2 in Vitamin D-Induced Vascular Calcification

Abstract

The transdifferentiation of vascular smooth muscle cells (VSMCs) into osteoblast-like cells has been implicated in the context of vascular calcification. We investigated the roles of vitamin D receptor (Vdr) and runt-related transcription factor 2 (Runx2) in the osteoblastic differentiation of VSMCs in response to vitamin D3 using in vitro VSMCs cultures and in vivo in Vdr knockout (Vdr -/-) and Runx2 carboxy-terminus truncated heterozygous (Runx2 +/ΔC) mice. Treatment of VSMCs with active vitamin D3 promoted matrix mineral deposition, and increased the expressions of Vdr, Runx2, and of osteoblastic genes but decreased the expression of smooth muscle myosin heavy chain in primary VSMCs cultures. Immunoprecipitation experiments suggested an interaction between Vdr and Runx2. Furthermore, silencing Vdr or Runx2 attenuated the procalcific effects of vitamin D3. Functional cooperation between Vdr and Runx2 in vascular calcification was also confirmed in in vivo mouse models. Vascular calcification induced by high-dose vitamin D3 was completely inhibited in Vdr -/- or Runx2 +/ΔC mice, despite elevated levels of serum calcium or alkaline phosphatase. Collectively, these findings suggest that functional cooperation between Vdr and Runx2 is necessary for vascular calcification in response to vitamin D3.

Systems biology identifies cytosolic PLA2 as a target in vascular calcification treatment

“…Female C57BL/6 mice were treated with AACOCF3 (10 mg/kg) or its vehicle (methylcellulose 0.5% containing 0.5% M ethanol) via gavage and were fed a calcium-reduced diet (Altromin, C1031). Subsequently, mice were injected subcutaneously with 400,000 IU/kg BW of cholecalciferol (MilliporeSigma) or vehicle for 3 days (35,36). After 6 days of treatment, blood was collected by retroorbital puncture under isoflurane inhalation anaesthesia.…”

1,25(OH)2D3regulates the proangiogenic activity of pericyte through VDR‐mediated modulation of VEGF production and signaling of VEGF and PDGF receptors

“…We previously showed that 1,25(OH) 2 D 3 minimally affects proliferation and migration of retinal EC in culture, consistent with the lack of vitamin D–mediated osteoblastic differentiation in EC . Here, we tested the hypothesis that 1,25(OH) 2 D 3 inhibits PC proliferation and migration through increased VEGF production, thus attenuating the proangiogenic activity of PC.…”

“…The family of MAPK and AKT signaling pathways are involved in the regulation of diverse range of cellular processes including 1,25(OH) 2 D 3 mediated VSMC osteoblastic differentiation and calcification . Here, we examined the effect of 1,25(OH) 2 D 3 , VEGF, and VEGF and PDGF on MAPK protein expression and activity including p38 and extracellular‐signal‐regulated kinases (ERK), and AKT in PC (Figure ).…”

“…How 1,25(OH) 2 D 3 causes the increased expression of α 5 β 1 integrin remains elusive, and may be linked to induction of calcification as demonstrated in VSMC through α 5 β 1 /ERK/Runx2 pathway . The interaction between Runx2 and VDR modulates the expression of many genes affecting various cellular functions including adhesion and migration . However, the direct role of VDR and its potential interactions with other coregulatory factors that may affect integrin expression is complex and needs further investigation.…”

Nedd4 Deficiency in Vascular Smooth Muscle Promotes Vascular Calcification by Stabilizing pSmad1

“…In addition to our observations, it is also reported that vitamin D treatment on the VSMC increases the expressions of vitamin D receptor (VDR), runt related transcription factor 2 (Runx2), and osteoblastic genes. The interaction between VDR and Runx2 and functional cooperation between these two by vitamin D contributes to the VSMC transdifferentiation into osteoblast‐like cells . This mechanism might also partly explain the promoting effect of vitamin D on the VSMC calcification in Nedd4‐deficient mice.…”