AUTHOR=Terryn Joke , Verfaillie Catherine M. , Van Damme Philip TITLE=Tweaking Progranulin Expression: Therapeutic Avenues and Opportunities JOURNAL=Frontiers in Molecular Neuroscience VOLUME=14 YEAR=2021 URL=https://www.frontiersin.org/journals/molecular-neuroscience/articles/10.3389/fnmol.2021.713031 DOI=10.3389/fnmol.2021.713031 ISSN=1662-5099 ABSTRACT=

Frontotemporal dementia (FTD) is a neurodegenerative disease, leading to behavioral changes and language difficulties. Heterozygous loss-of-function mutations in progranulin (GRN) induce haploinsufficiency of the protein and are associated with up to one-third of all genetic FTD cases worldwide. While the loss of GRN is primarily associated with neurodegeneration, the biological functions of the secreted growth factor-like protein are more diverse, ranging from wound healing, inflammation, vasculogenesis, and metabolic regulation to tumor cell growth and metastasis. To date, no disease-modifying treatments exist for FTD, but different therapeutic approaches to boost GRN levels in the central nervous system are currently being developed (including AAV-mediated GRN gene delivery as well as anti-SORT1 antibody therapy). In this review, we provide an overview of the multifaceted regulation of GRN levels and the corresponding therapeutic avenues. We discuss the opportunities, advantages, and potential drawbacks of the diverse approaches. Additionally, we highlight the therapeutic potential of elevating GRN levels beyond patients with loss-of-function mutations in GRN.