C57BL/6-Tg(LMNA*G608G)HClns/J

Stock number: 010667
Product name: LMNA G608G
Research areas: Cardiovascular Research, Neurobiology Research, Research Tools

Description

These G608G transgenic mice develop progressive large artery arteriosclerosis and vascular smooth muscle cell loss and may have applications in studies of laminopathies such as Hutchinson-Gilford progeria syndrome.

Detailed description

These transgenic mice express the mutant human lamin A protein, progerin. Progerin is a toxic protein with a 50 amino acid deletion near its C-terminus caused by RNA mis-splicing. The truncation in lamin A eliminates the proteolytic cleavage site for ZMPSTE24 (zinc metallopeptidase, STE24). This dominant negative mutation is a C to T substitution at position 1824 in exon 11 (G608G - encoded amino acid for codon 608 remains glycine).

Hemizygous mice exhibit impaired blood pressure regulation with an abnormal response to the vasodilator, sodium nitroprusside. Histological analysis of large arteries, beginning at 5 months of age, reveals progressive vascular smooth muscle cell loss (VSMC), broken elastic fibers, thickened adventitia and medial layers, and proteoglycan and collagen accumulation in large arteries.  Hemizygous transgenic mice older than 12 months exhibit calcification and severe vascular smooth muscle cell loss and extracellular matrix deposition of the large arteries. The progressive cardiovascular disease observed in transgenic mice recapitulates the cardiovascular pathology seen in human patients. 

For the first 4 months after birth, homozygotes exhibit a slower rate of weight gain when compared to hemizygotes. In addition to developing kyphosis, hair loss, tight skin, loss of subcutaneous fat and joint contracture, homozygotes develop a significantly more severe vascular damage with VSMC loss in aortic vessel walls, calcification, and periadventitial thickening. Homozygotes die at an average of 7-8 months of age as the result of aortic stiffening and impaired cardiovascular functioning. The Donating Investigator reports that homozygous females are infertile and that a lower than expected number of homozygotes are born.

 

Development

The 164.4 kb human BAC RP11-702H12 containing the entire LMNA gene, as well as the UBQLN4, MAPBPIP, and RAB25 genes was modified to insert the G608G HGPS mutation and an FRT site flanked kanamycin selection cassette into exon 11 of the LMNA gene. The kanamycin selection cassette was removed by transient Flp-recombinase expression. The resulting circular BAC transgene, which contains the G608G mutation in exon 11, and 109 extra nucleotides in intron 10 including an FRT site, EcoRI site, and SacI site, was microinjected into C57BL/6 donor eggs. Founder line H, carrying two copies of the allele, was subsequently established. The mice were maintained on the C57BL/6 background. Upon arrival at The Jackson Laboratory, the mice were crossed to C57BL/6J (Stock No. 000664) at least once to establish the colony.

Allele

Symbol: Tg(LMNA*G608G)HClns
Name: transgene insertion H, Francis Collins
MGI accession ID: MGI:5441745
Generation method: Transgenic
Attributes: Inserted expressed sequence; Humanized sequence
Marker symbol: Tg(LMNA*G608G)HClns
Marker name: transgene insertion H, Francis Collins
Chromosome: 4
Strain of origin: C57BL/6
Expressed genes: LMNA,lamin A/C,human
Molecular note: The 164.4 kb human BAC RP11-702H12 containing the entire LMNA gene, as well as the UBQLN4, MAPBPIP, and RAB25 genes was modified to insert the G608G HGPS mutation and a FRT site flanked kanamycin selection cassette into exon 11 of the LMNA gene. The kanamycin selection cassette was removed by transient Flp-recombinase expression. The resulting circular BAC transgene, which contains the G608G mutation in exon 11, and 109 extra nucleotides in intron 10 including an FRT site, EcoRI site, and SacI site, was microinjected into C57BL/6 donor eggs. Founder line H was subsequently established.