Novel Vitamin D3 Hydroxymetabolites Require Involvement of the Vitamin D Receptor or Retinoic Acid-Related Orphan Receptors for Their Antifibrogenic Activities in Human Fibroblasts

Abstract

We investigated multiple signaling pathways activated by CYP11A1-derived vitamin D3 hydroxymetabolites in human skin fibroblasts by assessing the actions of these molecules on their cognate receptors and by investigating the role of CYP27B1 in their biological activities. The actions of 20(OH)D3, 20,23(OH)2D3, 1,20(OH)2D3 and 1,20,23(OH)3D3 were compared to those of classical 1,25(OH)2D3. This was undertaken using wild type (WT) fibroblasts, as well as cells with VDR, RORs, or CYP27B1 genes knocked down with siRNA. Vitamin D3 hydroxymetabolites had an inhibitory effect on the proliferation of WT cells, but this effect was abrogated in cells with silenced VDR or RORs. The collagen expression by WT cells was reduced upon secosteroid treatment. This effect was reversed in cells where VDR or RORs were knocked down where the inhibition of collagen production and the expression of anti-fibrotic genes in response to the hydroxymetabolites was abrogated, along with ablation of their anti-inflammatory action. The knockdown of CYP27B1 did not change the effect of either 20(OH)D3 or 20,23(OH)2D3, indicating that their actions are independent of 1α-hydroxylation. In conclusion, the expression of the VDR and/or RORα/γ receptors in fibroblasts is necessary for the inhibition of both the proliferation and fibrogenic activity of hydroxymetabolites of vitamin D3, while CYP27B1 is not required.

Vitamin D Attenuates Fibrotic Properties of Fibrous Dysplasia-Derived Cells for the Transit towards Osteocytic Phenotype

“…These findings suggest that 1,25(OH) 2 D 3 promotes osteogenic differentiation and mineralization in FD-derived cells, potentially restoring normal bone metabolism and structure in FD lesions. The therapeutic effects of 1,25(OH) 2 D 3 observed in our study are supported by previous studies demonstrating its anti-fibrotic [24,25], anti-proliferative [26,27], and pro-osteogenic [28] properties in various disease models. Vitamin D 3 has been shown to regulate key signaling pathways involved in fibrosis, proliferation, and osteogenesis, including the TGFβ1/mothers against decapentaplegic homolog (Smad) and wingless-type (Wnt)/β-catenin pathways [29,30].…”

Promising Functions of Novel Vitamin D Derivatives as Cosmetics: A New Fountain of Youth in Skin Aging and Skin Protection

“…Novel secosteroids exert their biological activity through VDR [259], the aryl hydrocarbon receptor (AhR) [230] and liver X receptors (LXRα and β) [231,263], yet at the same time, they acts as inverse agonists on retinoidrelated orphan receptors (RORα and RORγ) in murine [262] and human skin cells [264]. Similarly to 1,25(OH) 2 D3 [253], they show inhibitory effects on induced fibrotic activities in fibroblasts [265]. They inhibited genes involved in fibrosis, such as fibronectin (FN1), a growth factor for fibroblasts, ACTA1 (smooth muscle actin protein), as well as inflammatory genes, such as IL-1, IL-8, IL-33 and TGFB1.…”

Malignant Melanoma: An Overview, New Perspectives, and Vitamin D Signaling

“…Both 20(OH)D3 and 20,23(OH) 2 D3 and their downstream metabolites have been identified as inverse agonists of RORα and RORγ [ 409 , 483 , 485 ], reducing basal receptor activity and thus displaying anticancer, anti-inflammatory, and antifibrotic activities [ 409 , 485 , 492 , 493 , 494 ]. These receptors are expressed in skin, including melanoma cells [ 408 , 409 ].…”

“…For the human WM164 melanoma these effects were partially dependent on the VDR as demonstrated in experiments with knocked down (KD) VDR vs. mock transfected cells (wild type: WT) [ 489 ]. To get a better insight into the regulation of melanoma transcriptosome, we isolated RNA from these cells treated for 24 h with 1,25(OH) 2 D3, 1,20(OH) 2 D3, 25(OH)D3, 20(OH)D3, or 0.1% ethanol (control) and submitted these samples for RNA sequencing by BGI Americas Corporation Service (Cambridge, MA, USA), as previously described [ 493 , 494 ]. The resulting raw data were deposited at GEO (GSE248660).…”

“…Peroxisome proliferator-activated receptor γ (PPARγ) is also considered as the receptor for CYP11A1-derived hydroxyderivatives of vitamin D and of hydroxyderivatives of lumisterol [496] (paper in preparation) and tachysterol [468]. It should be noted that VDR-independent mechanisms of action have also been indicated Both 20(OH)D3 and 20,23(OH)2D3 and their downstream metabolites have identified as inverse agonists of RORα and RORγ [409,483,485], reducing basal re activity and thus displaying anticancer, anti-inflammatory, and antifibrotic act [409,485,[492][493][494]. These receptors are expressed in skin, including melanoma [408,409].…”