If you are interested in perusing some of the past decade of science on this topic, some links below. It is about equally devoted to looking at what happens in induced pluripotency versus what happens during embryonic development, induced pluripotent stem cells and embryonic stem cells being basically the same thing.

Elimination of damaged proteins during differentiation of embryonic stem cells https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1472508/

In Vivo Amelioration of Age-Associated Hallmarks by Partial Reprogramming https://doi.org/10.1016/j.cell.2016.11.052

Mitochondrial Rejuvenation After Induced Pluripotency https://doi.org/10.1371/journal.pone.0014095

Aging vs. rejuvenation: reprogramming to iPSCs does not turn back the clock for somatic mitochondrial DNA mutations http://dx.doi.org/10.21037/sci.2016.08.09

A lysosomal switch triggers proteostasis renewal in the immortal C. elegans germ lineage https://doi.org/10.1038/nature24620

Any Rejuvenation Relevance for Roundworm Reproduction? http://www.sens.org/research/research-blog/question-month-16...