Biology subjects

Zhan, J. J.

Publications and source records attributed to Zhan, J. J..

4 recordsLinked to original sources

bioRxiv2026

Development of a metabolomics-based index to monitor dietary effects on chronic inflammation: The Dietary Metabolomics Inflammation Index

BackgroundThe Dietary Inflammatory Index (DII) is widely used to assess the inflammatory potential of diet, but it relies on self-reported dietary assessment and does not directly capture individual differences in metabolism as an intermediate connection to inflammation. High-resolution metabolomics provides objective measurements that complement dietary assessment to support precision nutrition to control inflammation. ObjectiveWe developed, tested, and applied a Dietary Metabolite Inflammatory Index (DMII) to assess diet-related chronic inflammation using metabolites measured by liquid chromatography-high-resolution mass spectrometry. MethodsDII was calculated using dietaryindex R package with Block Food Frequency Questionnaire (FFQ) data. To develop the DMII, chronic inflammation-related dietary metabolites corresponding to the DII food parameters were found through a literature review. Dietary metabolites were identified and quantified by authentic standards by our established laboratory procedures. DMII uses the same inflammatory effect scores as the DII. Three DMII versions were developed: concentration-based, median-based, and quintile-based DMII. Mean and standard deviation of 29 dietary metabolites were calculated by using 3025 human plasma samples from 3 studies. DMII was tested in the Center for Health Discovery and Well-Being cohort (CHDWB) and the Atlanta African American Maternal and Child cohort (ATLAA) using chronic inflammation biomarkers, including high-sensitivity C-reactive protein (hs-CRP), CRP, and IL-6. The median-based DMII was further applied to four Alzheimers disease metabolomics datasets as a proof-of-concept application. ResultsIn the CHDWB study, concentration-based DMII had a weak positive correlation with Block FFQ-derived DII and strongly correlated with median-based and quintile-based DMII. In the same study, all three DMII versions had significant positive correlations with hs-CRP and IL-6. In the ATLAA study, only concentration-based DMII was positively associated with CRP and IL-6. Higher median-based DMII was associated with higher odds of Alzheimers disease. ConclusionsDMII provides a metabolomics-based framework for assessing diet-related chronic inflammation using metabolomics data. This metabolomics approach may complement self-reported dietary assessment to use diet and nutrition to help protect against chronic disease linked to inflammation.

biochemistry↗

bioRxiv2023

Dietaryindex: A User-Friendly and Versatile R Package for Standardizing Dietary Pattern Analysis in Epidemiological and Clinical Studies

BackgroundFew standardized and open-source tools exist for calculating dietary pattern indexes from dietary intake data in epidemiological and clinical studies. Miscalculations of dietary indexes, with suspected erroneous findings, are occasionally noted in the literature. ObjectiveThe primary aim is to develop and validate dietaryindex, a user-friendly and versatile R package that standardizes the calculation of dietary indexes. MethodsDietaryindex utilizes a two-step process: an initial calculation of serving size for each food and nutrient category, followed by the calculation of individual dietary indexes. It includes generic functions that accept any preprocessed serving sizes of food groups and nutrients, with the standard serving sizes defined according to the methodologies used in well-known prospective cohort studies. For ease of use, dietaryindex also offers one-step functions that directly reference common datasets and tools, including the National Health and Nutrition Examination Survey (NHANES) and Block Food Frequency Questionnaire, eliminating the need for data preprocessing. At least two independent researchers validated the serving size definitions and scoring algorithms of dietaryindex. ResultsDietaryindex can calculate multiple dietary indexes of high interest in research, including Healthy Eating Index (HEI) - 2020, Alternative Healthy Eating Index 2010, Dietary Approaches to Stop Hypertension Index, Alternate Mediterranean Diet Score, Dietary Inflammatory Index, American Cancer Society 2020 dietary index, and Planetary Health Diet Index from the EAT-Lancet Commission. In our validation process, dietaryindex demonstrated full accuracy (100%) in all generic functions with two-decimal rounding precision in comparison to hand-calculated results. Similarly, using NHANES 2017-2018 data and ASA24 and DHQ3 example data, the HEI2015 outputs from dietaryindex aligned (99.95% - 100%) with results using the SAS codes from the National Cancer Institute. ConclusionsDietaryindex is a user-friendly, versatile, and validated informatics tool for standardized dietary index calculations. We have open-sourced all the validation files and codes with detailed tutorials on GitHub (https://github.com/jamesjiadazhan/dietaryindex).

bioinformatics↗

bioRxiv2019

Adaptive thermogenesis in mice requires adipocyte light-sensing via Opsin 3

Almost all life forms can decode light information for adaptive advantage. Examples include the visual system, where photoreceptor signals are interpreted as images, and the circadian system, where light entrains a physiological clock. Here we describe a local, non-visual light response in mice that employs encephalopsin (OPN3, a 480 nm, blue light responsive opsin) to regulate the function of adipocytes. Germ line null and adipocyte-specific conditional null mice show a deficit in thermogenesis that is phenocopied in mice under blue-light deficient conditions. We show that blue light stimulation of adipocytes activates hormone sensitive lipase, the rate limiting enzyme in the lipolysis pathway, and that this is OPN3-dependent. Opn3 adipocyte conditional null mice also use reduced levels of fat mass when fasted and cold exposed further suggesting a lipolysis deficit. These data suggest the hypothesis that in mice, a local, OPN3-dependent light response in adipocytes is a mechanism for regulation of energy homeostasis.

physiology↗

bioRxiv2018

An adipocyte light-Opsin 3 pathway regulates the circadian clock and energy balance.

Almost all life forms can detect and decode light information for adaptive advantage. Examples include the visual system, where photoreceptor signals are processed into virtual images, and the circadian system, where light entrains a physiological clock. Here we describe a pathway in mice that employs encephalopsin (OPN3, a 480 nm light responsive opsin) to mediate light responses in murine adipocytes. The adipocyte light-OPN3 pathway regulates neonatal growth in mice and is required for at least three important functions including (1) photoentrainment of a local circadian clock, (2) extracellular matrix deposition, and (3) regulation of mitochondrial content and the proportion of \"brite\" adipocytes. Furthermore, we show that the light-OPN3 pathway is required for normal levels of uncoupling protein 1 (UCP1) in white and brown adipose tissue. Consequently, neonatal Opn3 germ-line and adipocyte-conditional null mice show a reduced ability to maintain their body temperature under cold stress. This was also observed in wild-type mice deprived of blue light. We hypothesize that the adipocyte light-OPN3 pathway provides a dynamically responsive, circadian clock-integrated mechanism for regulating adipocyte function and in turn directing metabolism to thermogenesis rather than anabolism. These data indicate an important role for peripheral light sensing in mammals and may have broad implications for human health given the unnatural lighting conditions in which we live.

physiology↗