In Vivo Analysis of Gene Expression in Long-lived Mice Lacking the Pregnancy-associated Plasma Protein A (PappA) Gene
Overview
Affiliations
Mice lacking the pregnancy-associated plasma protein A (PappA) gene exhibit diminished localized IGF-1 bioavailability and a 30% increase in mean life span. However, it is uncertain which tissues exhibit reduced IGF-1 signals in the PappA(-/-) mouse, and whether effects of this mutation parallel those of mutations that diminish IGF-1 in serum. Across a panel of 21 tissues, we used RT-PCR to evaluate the effects of the PappA(-/-) mutation on expression of Igfbp5, which served as an in vivo indicator of IGF-1 signaling. Among these tissues, expression of Igfbp5 was significantly reduced by PappA(-/-) only in kidney. A broader survey of IGF-associated genes in six organs identified five other genes responsive to PappA(-/-) in kidney, with stronger effects in this organ relative to other tissues. Renal expression of Irs1 and Mt1 was increased by PappA(-/-) as well as by mutations that reduce IGF-1 in serum (i.e., Ghr(-/-), Pit1(dw/dw) and Prop1(df/df)), and we demonstrate that expression of these genes is regulated by growth hormone-treatment and calorie restriction. These results provide in vivo data on an important new model of mammalian aging, and characterize both similar and contrasting expression patterns between long-lived mice with reduced local IGF-1 availability and diminished IGF-1 in serum.
Bale L, West S, Gades N, Baker D, Conover C Exp Neurol. 2024; 382:114976.
PMID: 39349117 PMC: 11502239. DOI: 10.1016/j.expneurol.2024.114976.
Chambers T, Escott-Price V, Legge S, Baker E, Singh K, Walters J Mol Psychiatry. 2022; 27(4):2282-2290.
PMID: 35079123 PMC: 9126806. DOI: 10.1038/s41380-022-01443-8.
Pabis K, Chiari Y, Sala C, Straka E, Giacconi R, Provinciali M Geroscience. 2021; 43(4):1975-1993.
PMID: 34117600 PMC: 8492847. DOI: 10.1007/s11357-021-00393-3.
Mohrin M, Liu J, Zavala-Solorio J, Bhargava S, Trumble J, Brito A Aging Cell. 2021; 20(3):e13313.
PMID: 33561324 PMC: 7963332. DOI: 10.1111/acel.13313.
Kritschil R, Zhang Z, Lei C, Zhong J, Dong Q, Lee J JOR Spine. 2021; 3(4):e1112.
PMID: 33392450 PMC: 7770198. DOI: 10.1002/jsp2.1112.