Modulation of LMNA splicing as a strategy to treat prelamin A diseases
John M. Lee, … , Stephen G. Young, Loren G. Fong
John M. Lee, … , Stephen G. Young, Loren G. Fong
Published April 1, 2016; First published March 21, 2016
Citation Information: J Clin Invest. 2016;126(4):1592-1602. https://doi.org/10.1172/JCI85908.
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Research Article Aging Therapeutics

Modulation of LMNA splicing as a strategy to treat prelamin A diseases

Abstract

The alternatively spliced products of LMNA, lamin C and prelamin A (the precursor to lamin A), are produced in similar amounts in most tissues and have largely redundant functions. This redundancy suggests that diseases, such as Hutchinson-Gilford progeria syndrome (HGPS), that are caused by prelamin A–specific mutations could be treated by shifting the output of LMNA more toward lamin C. Here, we investigated mechanisms that regulate LMNA mRNA alternative splicing and assessed the feasibility of reducing prelamin A expression in vivo. We identified an exon 11 antisense oligonucleotide (ASO) that increased lamin C production at the expense of prelamin A when transfected into mouse and human fibroblasts. The same ASO also reduced the expression of progerin, the mutant prelamin A protein in HGPS, in fibroblasts derived from patients with HGPS. Mechanistic studies revealed that the exon 11 sequences contain binding sites for serine/arginine-rich splicing factor 2 (SRSF2), and SRSF2 knockdown lowered lamin A production in cells and in murine tissues. Moreover, administration of the exon 11 ASO reduced lamin A expression in wild-type mice and progerin expression in an HGPS mouse model. Together, these studies identify ASO-mediated reduction of prelamin A as a potential strategy to treat prelamin A–specific diseases.

Authors

John M. Lee, Chika Nobumori, Yiping Tu, Catherine Choi, Shao H. Yang, Hea-Jin Jung, Timothy A. Vickers, Frank Rigo, C. Frank Bennett, Stephen G. Young, Loren G. Fong

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Figure 6

ASO E11-31 reduces the expression of lamin A in wild-type mice and progerin in LmnaG609G/G609G mice.

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ASO E11-31 reduces the expression of lamin A in wild-type mice and proge...
(A) ASO E11-31 increases lamin C transcript levels in vivo. Wild-type mice (n = 4 per group) were treated with ASO E11-31 or a scrambled oligonucleotide (Control ASO) for 4 weeks. Two days after the last injection, RNA was isolated from liver tissue. Prelamin A and lamin C transcript levels were measured by qRT-PCR (mean ± SEM). *P < 0.05, t test. (B) ASO E11-31 lowers lamin A protein levels in vivo. Lamin A and lamin C protein levels (relative to actin) in the livers of control- and E11-31–treated mice (described in A) were measured by Western blotting and graphed. *P < 0.05, t test. (C) ASO E11-31 decreases progerin levels in the aortas of LmnaG609G/G609G mice. One-month-old LmnaG609G/G609G mice were treated with ASO E11-31 or a scrambled oligonucleotide (n = 3) for 3 months. Two days after the last injection, the mouse aortas were dissected free of attached tissues. Lamin A, progerin, and lamin C protein levels in the aorta were measured by Western blotting with an antibody against the amino terminus of lamin A (a region common to all 3 isoforms). Actin levels were measured as a loading control. The results are shown for 2 wild-type mice (+/+), two LmnaG609G/G609G (609/609) mice treated with the control ASO (Con ASO1 and Con ASO2), and an LmnaG609G/G609G mouse treated with ASO E11-31 (E11-31 ASO1). (D) Histological images showing reduced disease in the ascending aortas of ASO E11-31–treated LmnaG609G/G609G mice. Images (original magnification, ×10) of Masson’s trichrome–stained cross sections through the ascending aortas from 1 wild-type mouse (Lmna+/+), 1 LmnaG609G/G609G mouse treated with a control ASO (Con ASO1), and 1 LmnaG609G/G609G mouse treated with ASO E11-31 (E11-31 ASO2). White bars identify the adventitia. Scale bar: 100 μm.