Mohn Emily S, Erdman John W, Neuringer Martha, Kuchan Matthew J, Johnson Elizabeth J
Jean Mayer United States Department of Agriculture Human Nutrition Research Center on Aging, Tufts University, Boston, MA USA.
Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL USA.
Genes Nutr. 2017 Mar 8;12:9. doi: 10.1186/s12263-017-0557-3. eCollection 2017.
The dietary xanthophylls, lutein and zeaxanthin, accumulate in primate retina and brain, and emerging evidence indicates neural lutein content may be beneficial for cognition. Neural xanthophyll content in primates varies greatly among individuals, and genetic factors are likely to be significant contributors. Subspecies of rhesus macaques originating from different geographic locations are known to differ genetically, but the effect of origin on gene expression and carotenoid status has not been determined. The study objective was to determine whether xanthophyll status and expression of carotenoid-related genes, as well as genes with known variants between subspecies, differ between the brains of adult rhesus monkeys of Indian and Chinese origin.
Samples of prefrontal cortex, cerebellum, and striatum were collected from adult monkeys ( = 9) fed a standard stock diet containing carotenoids. Serum and brain carotenoids were determined using reverse-phase high-performance liquid chromatography. For each brain region, RNA sequencing and real-time quantitative polymerase chain reaction were used to determine differentially expressed genes between the subspecies.
Indian-origin monkeys had higher xanthophyll levels in brain tissue compared to Chinese-origin monkeys despite consuming similar amounts of dietary carotenoids. In a region-specific manner, four genes related to carotenoid and fatty acid metabolism (, , , ) and four genes involved in the immune response (, , ) were differentially expressed between Indian- and Chinese-origin monkeys. Expression of all four genes involved in carotenoid and fatty acid metabolism were correlated with brain xanthophyll concentration in a region-specific manner.
These results indicate that origin is related to differences in both gene expression and xanthophyll content in the brain. Findings from this study may have important implications regarding genetic diversity, lutein status, and cognition in primates.
膳食中的叶黄素和玉米黄质会在灵长类动物的视网膜和大脑中积累，越来越多的证据表明，神经叶黄素含量可能对认知有益。灵长类动物的神经叶黄素含量在个体间差异很大，遗传因素可能是重要的影响因素。已知来自不同地理位置的恒河猴亚种在基因上存在差异，但起源对基因表达和类胡萝卜素状态的影响尚未确定。本研究的目的是确定印度和中国起源的成年恒河猴大脑中，类胡萝卜素状态、类胡萝卜素相关基因的表达，以及亚种间已知变异基因的表达是否存在差异。
从喂食含类胡萝卜素标准饲料的成年猴子（n = 9）中采集前额叶皮质、小脑和纹状体样本。使用反相高效液相色谱法测定血清和脑类胡萝卜素。对于每个脑区，使用RNA测序和实时定量聚合酶链反应来确定亚种间差异表达的基因。
尽管食用的膳食类胡萝卜素量相似，但与中国起源的猴子相比，印度起源的猴子脑组织中的叶黄素水平更高。以区域特异性方式，印度和中国起源的猴子之间，四个与类胡萝卜素和脂肪酸代谢相关的基因（，，，）和四个参与免疫反应的基因（，，）存在差异表达。所有四个参与类胡萝卜素和脂肪酸代谢的基因的表达均以区域特异性方式与脑叶黄素浓度相关。
这些结果表明，起源与大脑中基因表达和叶黄素含量的差异有关。本研究结果可能对灵长类动物的遗传多样性、叶黄素状态和认知具有重要意义。
