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Biju, R.

Publications and source records attributed to Biju, R..

2 recordsLinked to original sources

Strong inhibition of insulin/IGF-1 signaling in early-mid adulthood compresses morbidity, but in later life accelerates aging

Reduced insulin/IGF-1 signaling (IIS) can greatly extend lifespan in C. elegans. However, its effects on the duration of healthy life (healthspan) remain unclear, with several reports of either morbidity expansion or scaled effects, though none of morbidity compression. Moreover, life-extension by IIS reduction is particularly inter-individually variable within populations, confounding efforts to understand the intra-individual biology of such interventions. Here, we performed a longitudinal investigation at individual nematode resolution, of IIS reduction on aging-related health and lifespan, through temporally-controlled auxin-induced degradation (AID) of the DAF-2 insulin/IGF-1 receptor. Our results show how inter-individual variation in aging rate within control populations explains the complex demographic effects of age-specific DAF-2 AID on population lifespan. Strikingly, adult-limited IIS reduction causes an inter-individually homogeneous increase in lifespan (reducing Gompertz rather than {beta}) that is driven by healthspan expansion and compression of morbidity. Unexpectedly, cessation of DAF-2 AID in decrepit elderly individuals rejuvenates locomotory capacity and extends lifespan, showing that higher levels of IIS are optimal for health and survival towards the end of life. We also document a memory effect of transient IIS reduction during early adulthood, that is sufficient to fully extend lifespan (+189% median lifespan). Together, these findings demonstrate that both lifespan and healthspan can be maximized by appropriate temporal and directional modulation of IIS.

genetics↗

SEAHORSE: A Serendipity Engine Assaying Heterogeneous Omics-Related Sampling Experiments

Large public molecular atlases such as the Genotype-Tissue Expression (GTEx) project and The Cancer Genome Atlas (TCGA) invite systematic discovery, yet most analyses remain hypothesis-driven and interrogate a tiny fraction of possible relationships among phenotypic, clinical, and molecular variables. We developed SEAHORSE (Serendipity Engine Assaying Heterogeneous Omics-Related Sampling Experiments), a discovery engine and accompanying R package that exhaustively precomputes all pairwise associations across heterogeneous data types and presents them as a searchable association landscape. Using GTEx (948 donors, 43 tissues, 154 phenotypes), SEAHORSE generated 341,008 phenotype-phenotype associations, 125,246,938 phenotype-gene associations, and 10,269,910,410 gene-gene correlations. In parallel analyses spanning 33 tumor types in TCGA, SEAHORSE generated 625,042 phenotype-phenotype associations, 183,080,369 phenotype-gene associations, and 12,096,948,950 gene-gene correlations. Across GTEx, height was repeatedly associated with enrichment of transcriptional programs, most strikingly the Kyoto Encyclopedia of Genes and Genomes (KEGG) term "Pathways in Cancer," significant in 17 tissues, offering a molecular entry point into long-reported links between stature and cancer risk. Height was also associated with immune, cardiovascular, and neurologic programs. In TCGA, age was consistently associated with WNT signaling, translation, cell differentiation, and cell cycle programs across tumors. These findings illustrate a new paradigm: large cohorts should be treated not merely as repositories for testing preconceived hypotheses but as association landscapes that can generate unexpected biological hypotheses.

bioinformatics↗