SPARC expression in the mouse decidua, placenta, and fetus: correlations with SPP1 expression

Area of Science:

• Reproductive biology
• Developmental biology
• Extracellular matrix research

Background:

• Secreted protein acidic and rich in cysteine (SPARC) and secreted phosphoprotein 1 (SPP1) are matricellular proteins involved in cell migration, tissue remodeling, and angiogenesis.
• While SPP1's role in pregnancy is well-documented, SPARC's contribution remains less understood.

Purpose of the Study:

• To investigate the localization and potential interactions of SPARC and SPP1 during mouse pregnancy.
• To elucidate the role of SPARC in the maternal-fetal environment.

Main Methods:

• Utilized in situ hybridization and immunofluorescence microscopy.
• Examined Sparc and Spp1 mRNA and protein expression in mouse fetuses, decidua, and placentae across different gestational days.
• Employed a delayed implantation mouse model.

Main Results:

• SPARC mRNA and protein were localized to the endometrial stroma, parietal yolk sac, Reichert's membrane, and trophoblast lineages.
• SPP1 was highly expressed in the endometrial luminal epithelium, uterine NK cells, and glycogen trophoblast cells.
• Both SPARC and SPP1 were found in multiple regions of the GD16 fetus, including developing cartilage.

Conclusions:

• The expression patterns suggest spatio-temporal and mechanistic links between SPARC and SPP1 in pregnancy.
• SPARC is a significant component of the matricellular environment throughout gestation.
• Further research is required to fully understand SPARC's functional roles in pregnancy.