The Effects of Fluvastatin on Indian Hedgehog Pathway in Endochondral Ossification

Abstract

Statins have demonstrated to be effective for treating chondrodysplasia and its effects were believed to be associated with the fibroblast growth factor receptor 3 (FGFR3). Statins promoted the degradation of FGFR3 in studies using disease-specific induced pluripotent stem cells and model mice, however, recent studies using normal chondrocytes reported that statins did not degrade FGFR3. In order to further investigate the effects of statins in endochondral ossification, this study examined the influence of statins on Indian hedgehog (Ihh), another important component of endochondral ossification, and its related pathways. The chondrocyte cell line ATDC5 was used to investigate changes in cell proliferation, mRNA, and protein expression levels. In addition, an organ culture of a mouse metatarsal bone was performed followed by hematoxylin-eosin staining and fluorescent immunostaining. Results indicated that expression level of Ihh increased with the addition of statins, which activated the Ihh pathway and altered the localization of Ihh. Changes in cholesterol modification may have affected Ihh diffusibility; however, further experiments are necessary. A reactive increase in parathyroid hormone–related protein (PTHrP) was observed in addition to changes in the Wnt pathway through secreted-related protein 2/3 and low-density lipoprotein 5/6. This led to the promotion of cell proliferation, increase of the hypertrophic chondrocyte layer, inhibition of apoptosis, and decrease in mineralization. This study demonstrated that statins had an influence on Ihh, and that the hyperfunction of Ihh may prevent premature cell death caused by FGFR3-related chondrodysplasia through an indirect increase in the expression of PTHrP.

A critical bioenergetic switch is regulated by IGF2 during murine cartilage development

“…We next applied 3-NPA to cultured metatarsal bones, which we and others have used as an ex vivo model of cartilage development and long bone growth 20,[37][38][39][40][41] . Considering metatarsal bone cultures might require a higher concentration of 3-NPA than the two-dimensional chondrocyte cultures in our in vitro study, we used 1.0 and 3.0 mM 3-NPA for adequate tissue penetration.…”

Fluvastatin promotes chondrogenic differentiation of adipose-derived mesenchymal stem cells by inducing bone morphogenetic protein 2

“…In the present study, we revealed the positive effects of fluvastatin on chondrogenic differentiation of hADMSCs in the absence of exogenous growth factors. Fluvastatin significantly induced BMP2, SOX9, ACAN and COL2A1 expressions and accumulated GAGs in the pellet of Statins were previously reported to promote chondrogenic differentiation of ATDC5 cells, an in vitro model of chondrogenic differentiation, and to rescue the chondrogenic differentiation ability of induced pluripotent stem (iPS) cells from patients with achondroplasia or thanatophoric dysplasia [29,30]. These studies proposed that the mechanism by which statins influence chondrogenic differentiation is related to the Indian Hedgehog pathway or fibroblast growth factor receptor 3 (FGFR3); however, it is not fully understood.…”