Stem Cell Rejuvenation via Heterochronic Parabiosis: A Literature Review and Case Analysis

Aging is a complex biological process marked by progressive tissue function decline and reduced regenerative capacity, with stem cell exhaustion being a key driver. Heterochronic parabiosis (HP), which surgically connects the circulatory systems of young and old organisms, has become a vital tool for exploring systemic rejuvenation, especially its role in reversing age-related stem cell dysfunction via young blood factors. This review synthesizes current knowledge on HP, analyzes key studies (including one using single-cell transcriptomics to demonstrate multi-tissue rejuvenation), and addresses controversies around factors like GDF11 and TIMP2. It also discusses challenges such as species translatability and ethical concerns, and concludes by proposing future directions like refined factor-based therapies and combinatorial approaches targeting stem cell niches.