The Sweetness of Embryonic Elongation and Differentiation

Targeting p53-p21 signaling to enhance mesenchymal stem cell regenerative potential

Mesenchymal stem cells (MSCs) are properties of self-renewal and differentiation potentials and thus are very appealing to regenerative medicine. Nevertheless, their therapeutic potential is frequently constrained by senescence, limited proliferation, and stress-induced apoptosis. The key role of the p53-p21 biology in MSC biology resides in safeguarding genomic stability while promoting senescence and limiting regenerative capacity upon over-activation demonstrated. This pathway is a key point for improving MSC function and exploiting the inherent limitations. Recent advances indicate that senescence can be delayed by targeting the p53-p21 signaling and improved MSC proliferation and differentiation capacity. PFT-α pharmacological agents transiently inhibit p53 from increasing proliferation and lineage-specific differentiation, while antioxidants such as hydrogen-rich saline and epigallocatechin 3 gallate (EGCG) suppress oxidative stress and attenuate p53 p21 signaling. Genetic tools like CRISPR-Cas9 and RNA interference also precisely modulate TP53 and CDKN1A expression to optimize MSC functionality. The interplay of p53-p21 with pathways like Wnt/β-catenin and MAPK further highlights opportunities for combinatorial therapies to enhance MSC resilience and regenerative outcomes. This review aims to offer a holistic view of how p53-p21 targeting can further the regenerative potential of MSCs, resolving senescence, proliferation, and stress resilience towards advanced therapeutics built on MSCs.

Neuromesodermal Progenitors: A Basis for Robust Axial Patterning in Development and Evolution

During early development the vertebrate embryo elongates through a combination of tissue shape change, growth and progenitor cell expansion across multiple regions of the body axis. How these events are coordinated across the length of the embryo to generate a well-proportioned body axis is unknown. Understanding the multi-tissue interplay of morphogenesis, growth and cell fate specification is essential for us to gain a complete understanding how diverse body plans have evolved in a robust manner. Within the posterior region of the embryo, a population of bipotent neuromesodermal progenitors generate both spinal cord and paraxial mesoderm derivatives during the elongation of the vertebrate body. Here we summarize recent data comparing neuromesodermal lineage and their underlying gene-regulatory networks between species and through development. We find that the common characteristic underlying this population is a competence to generate posterior neural and paraxial mesoderm cells, with a conserved Wnt/FGF and Sox2/T/Tbx6 regulatory network. We propose the hypothesis that by maintaining a population of multi-germ layer competent progenitors at the posterior aspect of the embryo, a flexible pool of progenitors is maintained whose contribution to the elongating body axis varies as a consequence of the relative growth rates occurring within anterior and posterior regions of the body axis. We discuss how this capacity for variation in the proportions and rates of NM specification might have been important allowing for alterations in the timing of embryo growth during evolution.