Identifying Global Rejuvenation Mechanisms in Tissues that Reverses Age-Related Phenotypes in Planarians

About This Grant

PROJECT SUMMARY/ABSTRACT The preservation of organ functions, such as eyesight and mobility, is a significant health concern in the elderly population. Organ frailty and disease progression are associated with the dysregulation of tissue homeostasis, which is typically regulated by regenerative units, consisting of adult stem cells (ASCs) and neighboring niche cells that regulate ASC function. Therefore, to better understand why regenerative functions decrease in aged individuals, uncovering how aging alters niche cell types and expression (mRNA) is critical for discovering regenerative therapeutical approaches. The potential to uncover molecular mechanisms to reverse age-related disorders prompted me to spatially profile microenvironmental niches in young, old, and regenerated tissues. I have recently developed Ex-Scope, which integrates Expansion Microscopy and Seq-Scope, a submicrometer-resolution ST (spatial transcriptomic) technology, to obtain a high-resolution multi-Omic method that represents an order of magnitude improvements over Seq-Scope. With the assistance of Dr. Guo, who has extensively worked on planarian tissues, we optimized Ex-Scope to spatially profile planarian tissue. Planarians are capable of regenerating any lost body part, but most importantly, regenerated tissues have a youthful tissue architecture; thus, making them ideal to study tissue homeostasis and rejuvenation. Using mRNA single-cell data on young, old, and regenerated planarians, as a reference dataset (obtained by Dr. Guo), we will provide spatial insight into rejuvenating mechanisms between microenvironmental niches and stem cells. Concurrent, we will demonstrate the advantageous resolution of Ex-Scope by profiling RNA granules in planarian stem cells and oocytes (young, old, and regenerated), which are compartmentalized biomolecules that regulate transcription in stem cells and the establishment of pluripotency. In aim 1) we propose to characterize RNA granules and soluble transcriptomes in planarian stem cells and oocytes, with a hypothesis that the granular structures in oocytes and ASCs would have transcriptome contents distinct from soluble cytoplasm, and 2) we propose to profile microenvironmental niches and their changes during aging and rejuvenation, with a hypothesis that aging and rejuvenation will affect cellular (single cell), tissue-level (microenvironment) and subcellular level (RNA granule) transcriptome, each of which is important for tissue function and homeostasis. We expect that the current work will give us a systematic understanding of how aging deteriorates tissue function by altering transcriptomic structure at both microscopic and macroscopic levels, and how regeneration can reverse it and rejuvenate tissue homeostasis.