Ou, N. | bioRxiv Science

bioRxiv2025

Testicular mRNA-LNP Delivery: A Novel Therapy for Genetic Spermatogenic Disorders

Uniform testicular maturation arrest is a severe form of male infertility characterized by the presence of germ cells that do not complete spermatogenic development. It is usually caused by meiotic arrest with genetic variants and difficult to treat via drugs or surgery. mRNA-lipid nanoparticle (LNP) delivery is a promising therapeutic option for maturation arrest with monogenic variants via protein replacement therapy. Herein, a spermatocytes-tropic LNP (Pool1-LNP3) was identified via a library of 30 ionizable lipids screening. And in vivo delivery of this novel LNP composition using rete testis microinjection was showed to be high spermatocytes targeting with high transfection efficiency. Thereafter, it was revealed that in vivo delivery of Pool1-LNP3 encapsulating Msh5 mRNA could promote crossover formation and restore spermatogenesis in Msh5D486Y/D486Y mouse models with DSB recombination defects. Notably, the offspring without genomic integration was born using intracytoplasmic sperm injection (ICSI) derived from rescue of Msh5D486Y/D486Ymouse and embryo transfer. Furthermore, no obvious inflammation and histologic damage in any tissue were detected after in vivo delivery of mRNA-LNP. In addition, it was demonstrated that Maps mRNA-LNP3 recovered spermatogenesis in Maps KO mouse with meiotic arrest. Altogether, these findings suggested that this spermatocytes-tropic mRNA-LNP delivery could become a viable and broad applicable strategy for treatment of spermatogenic disorders with genetic defects, providing a foundation for future clinical application.

molecular biology↗

bioRxiv2023

The tRNA Gm18 Methyltransferase TARBP1 Promotes Hepatocellular Carcinoma Progression via Metabolic Reprogramming of Glutamine

Cancer cells rely on metabolic reprogramming to sustain the prodigious energetic requirements for rapid growth and proliferation. Glutamine metabolism is frequently dysregulated in cancers and is being exploited as a potential therapeutic target. In current study, we identified TARBP1 (TAR (HIV-1) RNA Binding Protein 1) as a novel driver gene critical for glutamine metabolic reprogramming in tumor through the CRISPRi/Cas9 screening. Our in vivo and in vitro assays demonstrated that TARBP1 is the methyltransferase of Guanosine 2-O-methylation targeting position 18 (G18) of tRNAGln (TTG/CTG) and tRNASer (TGA/GCT), and loss of Gm18 modification diminishes the stability of tRNAs. Therefore, TARBP1 is critical for maintaining efficient translation of mRNA, in particular the glutamine transportor-ASCT2 (also known as SCL1A5). Importantly, TARBP1 is frequently amplified and overexpressed in HCC, consequentially promotes the protein synthesis of ASCT2 and glutamine import to fuel the growth of cancer cell, which is associated with poor patient survival. Taken together, this study reveals the critical role of TARBP1 in HCC progression through glutamine metabolic reprogramming and provides a potential target for tumor therapy.

cancer biology↗