June 22, 2023 – In a groundbreaking milestone in cell reprogramming, Hebrew University of Jerusalem (HU) researchers successfully transformed human skin cells into functional placenta cells for the first time.

The study, published in the prestigious journal Nature Communications, details this extraordinary achievement which could develop into new cell therapies, leading to improved diagnostic tools and therapeutic interventions. The findings open new avenues for investigating the causes of infertility, complications during pregnancy, and the long-term health of both mothers and babies.

Reprogramming cells to assume new identities has been a focus of lead researcher Prof. Yossi Buganim’s Lab for Stem Cell Biology and Cell Fate Decision at Hebrew University’s Faculty of Medicine, which utilizes specialized proteins to modify gene expression. By transforming skin cells into other cell types, the team can study specific diseases and the potential development of cell-based therapies.

Accessing cells in the placenta, a critical organ in pregnancy, has long been a challenge due to technical and ethical constraints. Prof. Buganim’s lab overcame these hurdles by deriving early human placental cells from plentiful skin cells, thus providing an unlimited supply for placental function study.

To achieve this, the team identified a set of genes that determine the identity of placental stem cells (Trophoblast Stem Cells), the precursor cells responsible for placental development. The researchers induced the expression of these genes in skin cells and successfully converted them into functional and stable placental stem cells which exhibited similar properties to cells obtained from early pregnancies. Comprehensive analyses, including multi-omics comparisons, validated the superiority of this method over previously published approaches.

The Hebrew University researchers used over-the-counter pregnancy tests to quickly evaluate their reprogrammed cells, as these cells produce various pregnancy hormones, including human chorionic gonadotropin (hCG).

The project was led by Dr. Moriyah Naama, an M.D./Ph.D. program participant, in collaboration with Moran Rahamim, a Ph.D. candidate, and other members of the Buganim lab.