PROJECT SUMMARY
Dilation & curettage (D&C) is one of the most common surgical procedures performed on women throughout the
world. Intrauterine adhesions (iUA), or Asherman, develop in about 40% of women who undergo D&C in the
postpartum (6 week period after birth), but is very rare after D&C in nonpregnant women (<1%) for reasons that
are not well understood. It is a debilitating condition characterized by intrauterine fibrosis and scarring. Patients
with iUA suffer from infertility, recurrent pregnancy loss and a broad range of dangerous pregnancy complications
(e.g. preterm birth). While endometrial mesenchymal stem/progenitor cells (eMPCs) are crucial for endometrial
repair, the role of these cells and underlying molecular mechanisms in this postpartum susceptibility of the
endometrium to fibrosis and abnormal repair are unknown. This application is specifically focused on defining
the role that eMPCs and their stromal fibroblast progeny play in abnormal uterine repair. The central hypothesis
is that eMPCs of the recently postpartum uterus are more senescent and inherently different in their response to
uterine injury compared to eMPCs of the nonpregnant uterus, leading to fibrosis and scar formation. The
approach is to use our novel postpartum mouse uterine injury model which recapitulates the susceptibility of the
human postpartum uterus to injury. Using it, we will define the dynamic changes in eMPCs and their differential
response to uterine injury in the postpartum vs. nonpregnant, identify using lineage tracing the eMPC subsets
that become the profibrotic fibroblast cells, and conditionally ablate each of these eMPC subsets to define their
functional role in endometrial fibrosis (Aim 1). We will obtain fresh human endometrial tissue from women
undergoing postpartum D&C and compare it to nonpregnant tissue using innovative single cell technology and
functional in vitro studies to gain detailed insights into the cellular and molecular differences that predispose the
human endometrium to form iUA (Aim 2). In Aim 3, we will obtain archived endometrial specimens from the time
of inciting D&C event from women who developed Asherman vs. non-Asherman. We will use the
innovative deterministic barcoding in tissue spatial multi-omics sequencing (DBiT-seq) platform and
integrate it with immunofluorescence to gain detailed molecular insights regarding eMPCs and their cell
interactions within the tissue, identifying novel therapeutic targets for iUA prevention. The proposed aims
are conceptually and technically innovative and together will have a broad impact on the field by filling a
substantial gap in our fundamental knowledge of endometrial biology and infertility pathogenesis using Omics
approach, which are major research priorities of the Fertility and Infertility Branch of the NICHD.
Ultimately, the knowledge gained from this proposal will not only be invaluable to our understanding of many
more subtle conditions of abnormal endometrial repair, but provide unique insights into the body’s
physiological anti-fibrotic wound healing mechanisms leading to a deeper understanding of the pathogenesis of
fatal idiopathic fibrotic diseases in other organs.