All-trans-retinoic acid suppresses rat embryo hindlimb bud mesenchymal chondrogenesis by modulating HoxD9 expression

Abstract

In vertebrates, 5 -Hoxd genes (Hoxd9), which are expressed in the hindlimb bud mesenchyme, participate in limb growth and patterning in early embryonic development. In the present study, We investigated the mechanisms by which ATRA regulates cultured E12.5 rat embryo hindlimb bud mesenchymal cells (rEHBMCs). Following exposure to ATRA over 24 h, mRNA and protein expression levels of HoxD9 were evaluated by reverse transcription-polymerase chain reaction (RT-PCR), quantitative real-time PCR (qPCR), and western blotting. Flow cytometry was used to detect apoptosis. ATRA inhibited the condensation and proliferation, and promoted the apoptosis rate of the rEHBMCs in a dose-dependent manner. Sox9 and Col2a1 in rEHBMCs were downregulated by ATRA in a dose-dependent manner at both mRNA and protein levels. Similarly, HoxD9 was downregulated by ATRA in a dose-dependent manner, in parallel with the cartilagespecific molecules Sox9 and Col2a1. Both qPCR and western blotting showed that both Shh and Gli3 were downregulated. Overexpression of HoxD9 reversed the effects of ATRA. These results demonstrate that ATRA suppresses chondrogenesis in rEHBMCs by inhibiting the expression of HoxD9 and its downstream protein targets, including Sox9 and Col2a1. This effect may also be correlated with inhibition of the Shh-Gli3 signaling pathway.

Amplifications of EVX2 and HOXD9-HOXD13 on 2q31 in mature cystic teratomas of the ovary identified by array comparative genomic hybridization may explain teratoma characteristics in chondrogenesis and osteogenesis

“…This may be the reason why the bone component is so common in teratomas and used for preoperative diagnosis. This is the first study on humans to support previous findings of chondrogenesis and osteogenesis on mouse model [ 63 , 64 ]. Here, we provide new insights into mature cystic teratomas of the ovary, which increase our understanding of teratoma polydermal differentiation.…”

“…Some intrinsic factors may also be involved, such as HOXD genes which are associated with bone development. In this study, HODX9 (which affects cartilage formation [ 63 ]) to HOXD13 (which affects the ossification of mature bone [ 64 ]) were amplified in all our teratoma samples. This may be the reason why the bone component is so common in teratomas and used for preoperative diagnosis.…”

Clinically diverse and perinatally lethal syndromes with urorectal septum malformation sequence

“…signaling (Hong et al, 2021). Both Shh (Seifert et al, 2009) and Gli3 (Mo et al, 2001) expression are reduced in rats with anorectal malformations (Liu et al, 2016).…”

“…Moreover, the identification of a missense variant in HOXD9 in Fetus 8 is also relevant to the Shh/CDX2 pathway. Reduction in Hoxd9 expression observed in embryonic limb buds of rats supplemented with all-trans-retinoic acid correlated with impaired Shh/Gli3 signaling and reduced Sox9/Col2a11 signaling ( Hong et al, 2021 ). Both Shh ( Seifert et al, 2009 ) and Gli3 ( Mo et al, 2001 ) expression are reduced in rats with anorectal malformations ( Liu et al, 2016 ).…”

Integrated regulation of chondrogenic differentiation in mesenchymal stem cells and differentiation of cancer cells

“…RA acts on the RARA moiety of PML-RARA fusion protein that will be degraded, and contributes leukemia cells to terminal differentiation and apoptosis [177]. RA inhibited the condensation and proliferation and dysregulated Sox9 and Col2a1 in a dose-dependent manner through inhibition of Shh/Gli3 pathway [178]. Subtype-specific RAR agonists as well as RA had a strong inhibitory effect on chondrogenic differentiation with decreased the expression levels of Col2a1 and Sox9 [179].…”