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Biomedical subjects

Hyun Hee Nam

Publications and source records attributed to Hyun Hee Nam.

2 recordsLinked to original sources

Precise progerin targeting using RfxCas13d: A therapeutic avenue for Hutchinson-Gilford progeria syndrome.

Hutchinson-Gilford progeria syndrome (HGPS), an extremely rare progressive genetic disorder, is caused by a point mutation in LMNA that induces progerin production, which disrupts cellular function and triggers premature aging and mortality. Despite extensive efforts, HPGS remains incurable. We successfully implemented a strategy using RfxCas13d to selectively target progerin mRNA at specific junction regions, without unintended cleavage and reduce its expression. This technique discriminated between normal lamin A and progerin, thus providing a safe and targeted therapeutic avenue to treat HGPS. Our approach effectively restored aberrant gene expression and progerin-induced cellular phenotypes, including senescence, mitochondrial dysfunction, and DNA damage in cells with HGPS and LMNAG608G/G608G mice. Notably, LMNAG608G/G608G mice exhibited improved progeroid phenotypes, suggesting a potential therapeutic application of this approach for other diseases resulting from abnormal RNA splicing.

Progeria↗

Mouse emi1 has an essential function in mitotic progression during early embryogenesis.

For successful mitotic entry and spindle assembly, mitosis-promoting factors are activated at the G(2)/M transition stage, followed by stimulation of the anaphase-promoting complex (APC), an E3 ubiquitin ligase, to direct the ordered destruction of several critical mitotic regulators. Given that inhibition of APC activity is important for preventing premature or improper ubiquitination and destruction of substrates, several modulators and their regulation mechanisms have been studied. Emi1, an early mitotic inhibitor, is one of these regulatory factors. Here we show, by analyzing Emi1-deficient embryos, that Emi1 is essential for precise mitotic progression during early embryogenesis. Emi1(-/-) embryos were found to be lethal due to a defect in preimplantation development. Cell proliferation appeared to be normal, but mitotic progression was severely defective during embryonic cleavage. Moreover, multipolar spindles and misaligned chromosomes were frequently observed in Emi1 mutant cells, possibly due to premature APC activation. Our results collectively suggest that the late prophase checkpoint function of Emi1 is essential for accurate mitotic progression and embryonic viability.

Anaphase-Promoting Complex-Cyclosome↗