Vascular Calcification: In Vitro Models under the Magnifying Glass

Abstract

Vascular calcification is a systemic disease contributing to cardiovascular morbidity and mortality. The pathophysiology of vascular calcification involves calcium salt deposition by vascular smooth muscle cells that exhibit an osteoblast-like phenotype. Multiple conditions drive the phenotypic switch and calcium deposition in the vascular wall; however, the exact molecular mechanisms and the connection between vascular smooth muscle cells and other cell types are not fully elucidated. In this hazy landscape, effective treatment options are lacking. Due to the pathophysiological complexity, several research models are available to evaluate different aspects of the calcification process. This review gives an overview of the in vitro cell models used so far to study the molecular processes underlying vascular calcification. In addition, relevant natural and synthetic compounds that exerted anticalcifying properties in in vitro systems are discussed.

Characterization of a Unique Spontaneous Calcifying Cell Line (CJ): a Novel Tool for the Study of Ectopic Calcification

“…In general, there is a traditional view of the EC phenomenon as a cellular degenerative, passive process and a newer view as an active, proactive process mediated by cellular metabolism [45]. The most widely used experimental system for CVC is the combination of primary cultures of arterial smooth muscle or valve stromal cells with high concentrations of phosphoric acid [19]. The above-mentioned cell death by high concentrations of phosphate inevitably leads to the loss of cellular metabolic systems, and CaP-ppt formation was explained as a physicochemical reaction associated with the alkalinization of the medium pH by high concentrations (44 mM) of sodium bicarbonate in DMEM culture medium [26].…”

“…This interesting observation of materials balance was first obtained with the use of CJ cells. In other words, osteoblasts [12], vascular smooth muscle cells [19], and cardiac valve stromal cells [20] all require medium changes every 2 to 3 days during culture, making it difficult to obtain accurate material balance data in the open systems. On the other hand, CJ cells can be cultured for a long period of time without medium change in the closed system, which enables accurate tracking of material balance.…”

“…Indeed, the addition of 2 mM phosphate, twice the physiological concentration (1 mM), induced a large amount of calcium phosphate precipitation (hereafter referred to as CaP-ppt) and increased expression of the osteogenic genes Runx2 and osteocalcin in a human VSMC culture system [17]. The impact of this increase in bone marker gene expression was so great that the theory of transformation of VSMC into osteoblast-like cells and the addition of β-GP or inorganic phosphate quickly became popular in CVC studies in vitro and is now the standard method for inducing calcification [18][19][20].…”

Interorgan communication in neurogenic heterotopic ossification: the role of brain-derived extracellular vesicles

“…Studies have revealed that vesicles derived from dying cells can concentrate calcium and act as nucleating structures for the crystallization of calcium salts. 49,50 Calcium deposits were also found around dead cells in osteogenic culture. 51 Furthermore, mitochondrial calcium overload is common in pyroptotic cells.…”

Novel in vitro evidence on the beneficial effect of quercetin treatment in vascular calcification

“…Although VC is a pathological process related to aging (Pescatore et al, 2019), many other chronic diseases, such as atherosclerosis, diabetes mellitus, hypertension, and chronic kidney disease, are closely associated with VC occurrence (Palit and Kendrick, 2014;Nicoll et al, 2016;Grootaert et al, 2018;Giha et al, 2022). Multiple mechanisms have been proposed to explain the calcification within the vessel wall, including the osteogenic differentiation of vascular smooth muscle cells (VSMCs) (Ceccherini et al, 2022). In healthy vessels, these contracting cells remain quiescent, regulating the vascular tone and blood pressure.…”