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The objective of the study was to explore the potential value of plasma indicators for identifying amnesic mild cognitive impairment (aMCI) and determine whether levels of plasma indicators are related to the performance of cognitive function and brain tissue volumes. In total, 155 participants (68 aMCI patients and 87 health controls) were recruited in the present cross-sectional study. The levels of plasma amyloid-β (Aβ) 40, Aβ42, total tau (t-tau), and neurofilament light (NFL) were measured using an ultrasensitive quantitative method. Machine learning algorithms were performed for establishing an optimal model of identifying aMCI. Compared with healthy controls, Aβ40 and Aβ42 levels were lower and NFL levels were higher in plasma of aMCI patients with an exception of t-tau levels. In aMCI patients, the higher plasma Aβ40 levels were correlated with the impaired episodic memory and negative correlations were observed between plasma t-tau levels and global cognitive function and gray matter (GM) volume. In addition, the higher plasma NFL levels were correlated with reduced hippocampus volume and total GM volume of the left inferior and middle temporal gyrus. An integrated model included clinical features, hippocampus volume, and plasma Aβ42 and NFL and had the highest accuracy for detecting aMCI patients (accuracy, 74.2%). We demonstrated that plasma Aβ40, Aβ42, t-tau, and NFL may be useful to identify aMCI and correlate with cognitive decline and brain atrophy. Among these plasma indicators, Aβ42 and NFL are more valuable as key members of a peripheral biomarker panel to detect aMCI.

Background: The apolipoprotein E epsilon4 (ApoE ε4) allele and female gender may be important risk factors for the development of Alzheimer’s disease and amnestic mild cognitive impairment (aMCI). Novelty mismatch negativity (MMN) represents the pre-attentive index of deviance detection and P3a represents the attention orienting response. Furthermore, MMN and P3a components have been reported to be potential markers in aMCI. Therefore, this study will investigate the effects of gender and ApoE on auditory novelty MMN and P3a and their relationship to neuropsychological performance in aMCI.Methods: Thirty nine aMCI subjects and 44 controls underwent neuropsychological assessment and ApoE genotyping. Novelty MMN and P3a components were investigated during an auditory novelty oddball task.Results: Firstly, novelty MMN latency was significantly shorter in aMCI than in healthy control (HC) group. Secondly, novelty MMN latency was negatively correlated with episodic memory in aMCI, but not in HC. Novelty P3a latency was negatively correlated with information processing speed in all subjects. For gender effect, novelty MMN latency was shorter in aMCI females than in HC females. Moreover, novelty P3a amplitudes were lower in males than in females in both aMCI and HC. For the effect of ApoE status, novelty MMN latency was shorter in aMCI ApoE ε4- than HC ApoE ε4-.Conclusion: aMCI presents altered pre-attentive processing indexed by novelty MMN components. Furthermore, there may be a compensatory mechanism on the impaired processing in aMCI. It further suggests that aMCI female and ApoE ε4- recruited the compensatory mechanism.

Coconut (Cocos nucifera L.) is a key tropical crop and a member of the monocotyledonous family Arecaceae (Palmaceae). Few genes and related metabolic processes involved in coconut endosperm development have been investigated. In this study, a new member of the WRI1 gene family was isolated from coconut endosperm and was named CoWRI1. Its transcriptional activities and interactions with the acetyl-CoA carboxylase (BCCP2) promoter of CoWRI1 were confirmed by the yeast two-hybrid and yeast one-hybrid approaches, respectively. Functional characterization was carried out through seed-specific expression in Arabidopsis and endosperm-specific expression in rice. In transgenic Arabidopsis, high over-expressions of CoWRI1 in seven independent T2 lines were detected by quantitative real-time PCR. The relative mRNA accumulation of genes encoding enzymes involved in either fatty acid biosynthesis or triacylglycerols assembly (BCCP2, KASI, MAT, ENR, FATA, and GPDH) were also assayed in mature seeds. Furthermore, lipid and fatty acids C16:0 and C18:0 significantly increased. In two homozygous T2 transgenic rice lines (G5 and G2), different CoWRI1 expression levels were detected, but no CoWRI1 transcripts were detected in the wild type. Analyses of the seed oil content, starch content, and total protein content indicated that the two T2 transgenic lines showed a significant increase (P < 0.05) in seed oil content. The transgenic lines also showed a significant increase in starch content, whereas total protein content decreased significantly. Further analysis of the fatty acid composition revealed that palmitic acid (C16:0) and linolenic acid (C18:3) increased significantly in the seeds of the transgenic rice lines, but oleic acid (C18:1) levels significantly declined.

Oil palm (Elaeis guineensis Jacq.) is the highest oil-yielding crop in the plant kingdom and accumulates 90% of palm oil in the mesocarp. However, the regulatory mechanisms of lipid and fatty acid (FA) metabolism in oil palm are just beginning to be understood, and more studies are needed, especially in the understanding of small noncoding RNA (ncRNA) and mRNA. Based on the deep sequencing of small noncoding RNAs and the degradome in five developmental mesocarp stages, 452 microRNAs (miRNAs), including 170 conserved known-miRNAs (kn-miRNAs) and 282 novel-miRNA (nov-miRNAs), were identified. After predicting the targets of those miRNAs to 37 FA synthesis-related genes, we found that 22 kn-miRNAs and 14 nov-miRNAs might be involved in FA metabolism pathways. Among them, eg-miR156c, eg-miR397, eg-miR444b and nov-miR129 regulated FA synthesis in plastids and the transport of FA-ACP from plastids to the endoplasmic reticulum by targeting acetyl-CoA carboxylase 1 (ACC1), long-chain acyl-CoA synthetase 9 (LACS9), LACS4 and enoyl-ACP reductase (ENR), respectively. Nov-miR138 and nov-miR59 targeted glycerol-3-phosphate acyltransferase (GPAT), and nov-miR274 targeted phosphatidate phosphatase 1 (PAP1). Both target genes are involved in triacylglycerol synthesis in the endoplasmic reticulum. Eg-miR156e and eg-miR156j played pivotal roles by targeting β-ketoacyl-CoA synthase 12 (KCS12), and nov-miR201 targets very-long-chain enoyl-CoA reductase (ECR). Several miRNAs were also predicted to indirectly regulate FA synthesis and lipid metabolism through the squamosa promoter-binding protein-like gene (SPL), NAC and MYB transcription factors. As a whole, indications of a complex and extensive miRNA-mRNA regulatory network associated with FA metabolism in the mesocarp of the oil palm is presented. The results help to broaden the knowledge of potential mechanisms that might be regulated by miRNAs through modulation of the expression of FA-related target gene metabolism in the oil palm.