Genetic analysis of intracapillary glomerular lipoprotein deposits in aging mice

Genetic background determines renal response to chronic lithium treatment in female mice

Background Chronic lithium treatment for bipolar disease causes mainly side effects in the kidney. A subset of lithium users develops nephrogenic diabetes insipidus (NDI), a urinary concentrating disorder, and chronic kidney disease (CKD). Age, lithium dose and duration of treatment are important risk factors, while genetic background might also play an important role. Methods In order to investigate the role of genetics, female mice of 29 different inbred strains were treated for one year with control or lithium chow and urine, blood and kidneys were analysed. Results Chronic lithium treatment increased urine production and/or reduced urine osmolality in 21 strains. Renal histology showed that lithium increased interstitial fibrosis and/or tubular atrophy in eight strains, while in none of the strains glomerular injury was induced. Interestingly, lithium did not elevate urinary albumin-creatinine ratio (ACR) in any strain, while eight strains even demonstrated a lowered ACR. The protective effect on ACR coincided with a similar decrease in urinary IgG levels, a marker of glomerular function, while the adverse effect of lithium on interstitial fibrosis/tubular atrophy coincided with a severe increase in urinary β2-microglobulin (B2M) levels, an indicator of proximal tubule damage. Conclusion Genetic background plays an important role in the development of lithium-induced NDI and chronic renal pathology in female mice. The strong correlation of renal pathology with urinary B2M levels indicates B2M as a promising biomarker for chronic renal damage induced by lithium.

The Jackson Laboratory Nathan Shock Center: impact of genetic diversity on aging

Healthspan is a complex trait, influenced by many genes and environmental factors that accelerate or delay aging, reduce or increase disease risk, and extend or reduce lifespan. Thus, assessing the role of genetic variation in aging requires an experimental strategy capable of modeling the genetic and biological complexity of human populations. The goal of the The Jackson Laboratory Nathan Shock Center (JAX NSC) is to provide research resources and training for geroscience investigators that seek to understand the role of genetics and genetic diversity on the fundamental process of aging and diseases of human aging using the laboratory mouse as a model system. The JAX NSC has available novel, deeply characterized populations of aged mice, performs state-of-the-art phenotyping of age-relevant traits, provides systems genetics analysis of complex data sets, and provides all of these resources to the geroscience community. The aged animal resources, phenotyping capacity, and genetic expertise available through the JAX NSC benefit the geroscience community by fostering cutting-edge, novel lines of research that otherwise would not be possible. Over the past 15 years, the JAX NSC has transformed aging research across the geroscience community, providing aging mouse resources and tissues to researchers. All JAX NSC data and tools are publicly disseminated on the Mouse Phenome Database and the JAX NSC website, thus ensuring that the resources generated and expertise acquired through the Center are readily available to the aging research community. The JAX NSC will continue to enhance its ability to perform innovative research using a mammalian model to illuminate novel genotype-phenotype relationships and provide a rational basis for designing effective risk assessments and therapeutic interventions to boost longevity and disease-free healthspan.

A roadmap for the genetic analysis of renal aging

Several studies show evidence for the genetic basis of renal disease, which renders some individuals more prone than others to accelerated renal aging. Studying the genetics of renal aging can help us to identify genes involved in this process and to unravel the underlying pathways. First, this opinion article will give an overview of the phenotypes that can be observed in age-related kidney disease. Accurate phenotyping is essential in performing genetic analysis. For kidney aging, this could include both functional and structural changes. Subsequently, this article reviews the studies that report on candidate genes associated with renal aging in humans and mice. Several loci or candidate genes have been found associated with kidney disease, but identification of the specific genetic variants involved has proven to be difficult. CUBN, UMOD, and SHROOM3 were identified by human GWAS as being associated with albuminuria, kidney function, and chronic kidney disease (CKD). These are promising examples of genes that could be involved in renal aging, and were further mechanistically evaluated in animal models. Eventually, we will provide approaches for performing genetic analysis. We should leverage the power of mouse models, as testing in humans is limited. Mouse and other animal models can be used to explain the underlying biological mechanisms of genes and loci identified by human GWAS. Furthermore, mouse models can be used to identify genetic variants associated with age-associated histological changes, of which Far2, Wisp2, and Esrrg are examples. A new outbred mouse population with high genetic diversity will facilitate the identification of genes associated with renal aging by enabling high-resolution genetic mapping while also allowing the control of environmental factors, and by enabling access to renal tissues at specific time points for histology, proteomics, and gene expression.