CXCR4, CXCR7, and CXCL12 Are Associated with Trophoblastic Cells Apoptosis and Linked to Pathophysiology of Severe Preeclampsia
The purpose of this paper was to examine the expression of the chemokine CXCL12 and its receptors, CXCR4 and CXCR7, in placental tissues and primary trophoblasts from preeclamptic and normal pregnancies. CXCL12 and its receptors are involved not only in the immune system, but also in various other processes, including remodeling the spiral arteries to form the placenta. CXCL12 and CXCR4 have been shown to be involved in trophoblast proliferation and invasion and decidual stromal cell migration and motility; lack of either of these functions is associated with preeclampsia. The authors examined the association between these proteins and preeclampsia.
Placentas were obtained after a cesarean section (21 normal pregnant, 11 mild preeclamptic, and 18 severe preeclamptic). A scanning electron microscope was used to observe morphological changes of trophoblast cells in preeclamptic placentas that caused a significant tendency towards apoptosis. Immunohistochemistry showed that there were lower levels of CXCR4, CXCR7, and CXCR12 were lower in severe preeclamptic placentas than in normal placentas. RT-qPCR was used to show that the same pattern was true for mRNA expression of the proteins, and Western blot analysis confirmed for protein expression levels in trophoblasts. The authors concluded that apoptosis of the cytotrophoblast cells may be regulated by expression of CXCR4, CXCR7, and CXCL12.
All three proteins have been shown to be important for proper placenta formation, so I think the research to compare expression between normal and preeclamptic patients is necessary and relevant. I think the study was well designed, especially by using different techniques to confirm results. However, the number of samples was small, only 50 in total, probably because the placenta was required for testing.
It would be interesting to see if the results in this study were replicated in a future study with more samples. While the study observes a decrease in the three proteins studied, more studies are required to understand the how they relate to the pathophysiology of preeclampsia. Additional studies should be done to understand the mechanism of cytotrophoblast invasion and how CXCL12 and its receptors relate to this.
Lu, Jing, et al. “CXCR4, CXCR7, And CXCL12 Are Associated With Trophoblastic Cells Apoptosis And Linked To Pathophysiology Of Severe Preeclampsia.” Experimental And Molecular Pathology 100. (2016): 184-191. ScienceDirect. Web. 9 Oct. 2016.