PCSK5 and GDF11 expression in the hindgut region of mouse embryos with anorectal malformations
1Department of Pediatric Surgery, Graduate School of Medical Science, Prefectural University of Medicine, Kyoto, Japan. tom@koto.kpu-m.ac.jp
Background/Purpose:
Retinoid-mediated signal transduction plays a crucial role in the embryonic development of various organs. We previously reported that retinoic acid induced anorectal malformations (ARM) in mice. GDF11 is a TGFβ superfamily molecule and is cleaved and activated by proprotein convertase subtilisin/kexin 5 (PCSK5). PCSK5 (PC5/6) mutations result in an abnormal expression of Hlxb9 and Hox genes, which include known GDF11 targets that are necessary for caudal development in vertebrate embryos. To determine a possible role of the retinoid-mediated signaling pathway in the pathogenesis of ARM, we investigated whether all-trans retinoic acid (ATRA) affected the expression patterns of PCSK5 and GDF11 in ARM-treated mouse embryos.
Methods:
Pregnant ICR-Slc mice were administered 100 mg/kg ATRA by gavage on embryonic day (E) 9.0. Embryos were harvested between days E12 and E18, and mid-sagittal sections of the hindgut region were prepared for immunohistochemistry using antibodies against PCSK5 (PC5/6) and GDF11 (GDF8/11).
Results:
Over 95% of the embryos treated with ATRA showed ARM, with rectourethral fistula or rectocloacal fistula, and a short tail. Furthermore, most of these embryos exhibited sacral malformations, tethered spinal cords, and presacral masses resembling those malformations found in caudal regression syndrome. By E14, normal mouse embryos formed a rectum and anus, and the somites behind the hindgut were positive for PC5/6 and GDF8/11. In contrast, in ARM embryos, the somites behind the hindgut were negative for PC5/6 and GDF8/11.
Conclusion:
ATRA treatment affected the caudal development in mouse embryos, resulting in anorectal, sacral, and spinal malformations, and inhibited PCSK5 and GDF11 expression in the hindgut region. These findings indicate that the expression of PCSK5 and GDF11, which plays a crucial role in the organogenesis of the hindgut, was disturbed in the hindgut region when retinoid-mediated signaling was disrupted. This study offers a new insight into the pathogenesis of ARM in mice as affected by the interaction between ATRA and PCSK5/GDF11.
Insights
All-trans retinoic acid (ATRA) exposure in mouse embryos caused anorectal malformations (ARM) and inhibited key developmental genes PCSK5 and GDF11. This suggests a link between retinoid signaling disruption and ARM pathogenesis.
Area of Science:
- Developmental Biology
- Molecular Biology
- Teratology
Background:
- Retinoid signaling is vital for embryonic organ development.
- Retinoic acid is known to induce anorectal malformations (ARM) in mouse models.
- PCSK5 (proprotein convertase subtilisin/kexin 5) and GDF11 are crucial for caudal development and are targets of GDF11.
Purpose of the Study:
- To investigate the role of the retinoid-mediated signaling pathway in ARM pathogenesis.
- To determine if all-trans retinoic acid (ATRA) affects the expression of PCSK5 and GDF11 in ARM-induced mouse embryos.
Main Methods:
- Pregnant mice were administered ATRA on embryonic day 9.0.
- Embryos were harvested and sectioned for immunohistochemistry.
- Antibodies against PCSK5 (PC5/6) and GDF11 (GDF8/11) were used to assess protein expression.
Main Results:
- Over 95% of ATRA-treated embryos exhibited ARM, including fistulas and short tails.
- Sacral malformations, tethered spinal cords, and presacral masses were observed in treated embryos.
- Normal embryos showed positive expression of PCSK5 and GDF11 in posterior hindgut somites by E14, while ARM embryos showed negative expression.
Conclusions:
- ATRA exposure leads to anorectal, sacral, and spinal malformations in mouse embryos.
- ATRA treatment inhibits the expression of PCSK5 and GDF11 in the hindgut region.
- Disruption of retinoid signaling impacts PCSK5 and GDF11 expression, contributing to ARM pathogenesis.
