Scientists uncover hidden role of VEGF in maintaining human stem cells' special state

2 min read

In the intricate dance of stem cell biology, researchers Wu X and colleagues have uncovered a previously unknown guardian of human embryonic stem cell (hESC) pluripotency. Endogenous VEGF signaling, once thought to be a minor player, emerges as a crucial component in sustaining primed hESC self-renewal and pluripotency.

The maintenance of pluripotency is typically governed by a delicate balance between various signaling pathways. However, the role of endogenous VEGF signaling in this process has remained understudied despite extensive research on exogenous signals. To elucidate this, the researchers employed targeted inhibition strategies, including pharmacological blockade with soluble decoy receptors (sFLT1/sKDR), CRISPR-mediated knockout of VEGFR1/2, and pharmacological inhibition of the BMP pathway. These approaches revealed that VEGF signaling is robustly activated in primed hESCs, quiescent in naïve cells, and inactivated upon differentiation.

Mechanistically, the researchers found that VEGFR inhibition activates the BMP pathway and down-regulates NANOG, a transcription factor that directly binds and represses select BMP components and trophoblast lineage-specific genes. The functional consequences of this signaling network are profound: targeting VEGF signaling in primed hESCs disrupts self-renewal and induces trophoblast-like differentiation. Moreover, the researchers found that partial inhibition of the BMP pathway partially rescues the phenotype induced by VEGF signaling ablation, while overexpression of NANOG substantially reverses the effects.

As we ponder the significance of this discovery, it becomes clear that endogenous VEGF signaling serves as a guardian of primed pluripotency. This finding highlights the complex interplay between different signaling cascades and transcription factors in regulating stem cell fate. The researchers' work not only advances our understanding of hESC biology but also underscores the intricate dance of molecular signals that govern our very existence – a delicate balance that underlies life itself, from the primed pluripotency of embryonic stem cells to the intricate networks of signaling pathways that govern our own cellular lives.

1 min read

In the quiet hours of a laboratory, a team of researchers stumbled upon an unexpected guardian of human potential. Wu X and her colleagues were studying the intricate dance of signals that keep human embryonic stem cells alive and pluripotent – capable of becoming any cell in the body. They had been exploring the usual suspects: external signals that nudge these cells into action, like a gentle push from a friend.

But what they found was surprising: an internal voice, whispering to the cells to remain primed for growth. This voice belonged to VEGF signaling, a pathway that is usually quiescent in adult cells but roars to life in embryonic stem cells. The researchers discovered that when this inner voice was silenced – by blocking its receptors or knocking out the genes that make it work – the cells began to lose their pluripotency and started down a path of differentiation, becoming specialized cells like trophoblasts.

This finding is significant because it reveals a previously hidden mechanism that keeps our bodies' building blocks in balance. The researchers' discovery opens up new avenues for understanding how these signals interact with each other and how they can be harnessed to promote healthy cell growth. It's a reminder that the most powerful tools are often those we don't fully understand – and that uncovering their secrets can lead to groundbreaking insights into human biology and our place in the world.

1 min read

Two types of stem cells exist in our bodies - one can become many different cell types, like skin cells or muscle cells, but stays very young and flexible. The other type is a master cell that can become anything it's told to be, from blood cells to organs. We're still learning how these special "master cells" work, and scientists have just discovered something new about them.

Researchers found that one of the signals in our bodies, called VEGF, helps keep these master cells young and flexible. It's like a protective spark that keeps them from changing into something else. But when this spark is taken away, the master cell starts to change into a different type of cell. This discovery is important because it shows us how our bodies control the growth of new cells, and how we might be able to help keep these special master cells healthy for longer.