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Bowdish, D. M.

Publications and source records attributed to Bowdish, D. M..

2 recordsLinked to original sources

Age-related biological dysregulation quantified using metabolomics is composed of distinct subsystems with synergistic associations to health outcomes: An analysis of the Canadian Longitudinal Study on Aging

Resilience is a fundamental component of healthy aging, whereby an organism can efficiently respond to external stressors and return to a resting biological and physiological state, known as homeostasis. This capacity declines with age in a heterogenous manner and is aggravated by biological dysregulation, a detrimental state broadly associated with health risk factors and poor outcomes. However, the underlying structure of dysregulation remains unclear, particularly in the context of older adult health trajectories. Here, we take a novel systems-based approach to the quantification of dysregulation using metabolomic data from n=9,992 older adults enrolled in the Canadian Longitudinal Study on Aging. We show that dysregulation across different biological systems is heritable, and exhibit distinct associations with health risk factors, indicators and outcomes, and DNA methylation patterns. Importantly, the effect of systems-specific dysregulation is cumulative, resulting in a significantly higher risk of disease incidence and death in older adults. Our findings broaden our understanding of biological dysregulation as a health state and demonstrate the value of system-specific dysregulation for effective strategies in personalized medicine and risk stratification.

physiology↗

Diet-induced obesity alters intestinal monocyte-derived and tissue-resident macrophages in female mice independent of TNF

Macrophages are essential for homeostatic maintenance of the anti-inflammatory and tolerogenic intestinal environment, yet monocyte-derived macrophages can promote local inflammation. Pro-inflammatory macrophage accumulation within the intestines may contribute to the development of systemic chronic inflammation and immunometabolic dysfunction in obesity. Using a model of high fat diet-induced obesity in C57BL/6J female mice, we assessed intestinal permeability by in vitro and in vivo assays, and quantitated intestinal macrophages in ileum and colon tissues by multicolour flow cytometry after short (6 weeks), intermediate (12 weeks), and prolonged (18 weeks) diet allocation. We characterized monocyte-derived CD4-TIM4- and CD4+TIM4- macrophages, as well as tissue-resident CD4+TIM4+ macrophages. Diet-induced obesity had tissue and time-dependent effects on intestinal permeability, as well as monocyte and macrophage numbers, surface phenotype, and intracellular production of the cytokines IL-10 and TNF. We found that obese mice had increased paracellular permeability, in particular within the ileum, but this did not elicit recruitment of monocytes, nor a local pro-inflammatory response by monocyte-derived or tissue-resident macrophages, in either the ileum or colon. Proliferation of monocyte-derived and tissue-resident macrophages was also unchanged. Wildtype and TNF-/- littermate mice had similar intestinal permeability and macrophage population characteristics in response to diet-induced obesity. These data are unique from reported effects of diet-induced obesity on macrophages in metabolic tissues, as well as outcomes of acute inflammation within the intestines, and collectively indicate that TNF does not mediate effects of diet-induced obesity on intestinal monocyte-derived and tissue-resident intestinal macrophages in young female mice. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=152 SRC="FIGDIR/small/509732v1_ufig1.gif" ALT="Figure 1"> View larger version (47K): org.highwire.dtl.DTLVardef@140a3c8org.highwire.dtl.DTLVardef@c0d887org.highwire.dtl.DTLVardef@c7c70dorg.highwire.dtl.DTLVardef@1dd5404_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗