An Integrated Proteomics and Genomics Approach to Identify Essential Protein Kinases During Human Trophoblast Development
Key kinases are identified as essential for trophoblast development, but further validation in human studies is needed to confirm their roles in pregnancy.
Where it sits
this study against the rest of the hcg (human chorionic gonadotropin) corpusSummary and findings
The study used human trophoblast stem cells to explore protein kinases essential for trophoblast development. Proteomics and genomics approaches identified kinases active in stem and differentiated states. The study highlights kinases critical for trophoblast development stages.
Abstract
In the developing human placenta, three subtypes of trophoblast cells, cytotrophoblasts (CTBs), extravillous trophoblasts (EVTs), and syncytiotrophoblasts (STBs), mediate critical functions essential for a successful pregnancy. CTBs constitute the stem/progenitor compartment and differentiate into STBs and EVTs within the floating and anchoring villi, respectively. STBs establish the maternal-fetal exchange interface and secrets human chorionic gonadotropin (hCG), a hormone vital for the maintenance of early pregnancy. EVTs anchor the maternal endometrium and invade the uterine tissue to remodel maternal cells, supporting implantation and progression of pregnancy. In this study, we used human trophoblast stem cells (hTSCs) as a model system and performed quantitative, label-free liquid chromatography tandem Mass Spectrometry (LC/MS/MS) to profile proteome and phosphoproteome in TSC stem state (analogous to undifferentiated CTBs) and following their differentiation to STBs and EVTs. Through a multiomics approach, we integrated our proteomics data with global gene expression profiles to correlate cell type specific gene and protein expression during human trophoblast development. We also identified global phosphoproteome and analyzed kinases that are specifically active in hTSC stem state, as well as in differentiated STBs and EVTs. We experimentally validated specific kinases, such as BUB1B, PAK6, PKYMT1 and TNIK are essential for maintaining the hTSC stem state. Additionally, atypical protein kinase C isoforms PKC zeta is essential for STB development, while PTK2B, SRC, TRIO and LYN are important for EVT development. Our findings highlight key kinases uniquely required for specific stages of trophoblast development during human placentation and suggest that pharmacological inhibition of these kinases could negatively impact the placentation process during pregnancy.
Background
The study addresses the role of protein kinases in the development of trophoblast cells, which are crucial for placental function and successful pregnancy. Trophoblasts differentiate into various subtypes, each with specific roles in pregnancy maintenance. Understanding the molecular mechanisms of trophoblast development is important for insights into pregnancy complications.
Methods
The researchers used human trophoblast stem cells to model trophoblast development. They employed quantitative, label-free liquid chromatography tandem Mass Spectrometry (LC/MS/MS) to profile the proteome and phosphoproteome. The study integrated proteomics data with global gene expression profiles to identify cell type-specific gene and protein expression.
Results
The study identified several kinases essential for different stages of trophoblast development. BUB1B, PAK6, PKYMT1, and TNIK were found to be critical for maintaining the stem state of hTSCs. PKC zeta was necessary for syncytiotrophoblast development, while PTK2B, SRC, TRIO, and LYN were important for extravillous trophoblast development.
Interpretation
The findings provide a detailed map of kinase activity during trophoblast development, which could inform future research on placental biology and pregnancy disorders. However, the clinical relevance is limited as the study is preclinical and conducted in vitro. Further research is needed to validate these findings in human pregnancies.
Key findings
- BUB1B, PAK6, PKYMT1, and TNIK are essential for maintaining hTSC stem state.
- PKC zeta is essential for syncytiotrophoblast (STB) development.
- PTK2B, SRC, TRIO, and LYN are important for extravillous trophoblast (EVT) development.
Limitations
- Preclinical, in vitro study
- Model system may not replicate in vivo conditions
- Findings require validation in human studies