Association of Plasma Phospholipids with Age-Related Cognitive Impairment: Results from a Cross-Sectional Study

Characterization of phospholipidome in milk, yogurt and cream, and phospholipid differences related to various dairy processing methods

Milk phospholipids have multiple health benefits, but the deficiency of detailed phospholipid profiles in dairy products brings obstacles to intake calculation and function evaluation of dairy phospholipids. In present study, 306 phospholipid molecular species were identified and quantified among 207 milk, yogurt and cream products using a HILIC-ESI-Q-TOF MS and a HILIC-ESI-QQQ MS. The phospholipid profiles of five mammals' milk show that camel milk contains the most abundant phosphatidylethanolamine, phosphatidylserine and sphingomyelin; cow, yak and goat milk have similar phospholipidomes, while buffalo milk contains abundant phosphatidylinositol. Fewer plasmalogens but more lyso-glycerolphospholipids were found in ultra-high-temperature (UHT) sterilized milk than in pasteurized milk, and higher proportions of lyso-glycerolphospholipid/total phospholipid were observed in both cream and skimmed/semi-skimmed milk than whole milk, indicating that UHT and skimming processes improve glycerolphospholipid degradation and phospholipid nutrition loss. Meanwhile, more diacyl-glycerolphospholipids and less of their degradation products make yogurt a better phospholipid resource than whole milk.

Exploring the relationship between lipid metabolism and cognition in individuals living with stable-phase Schizophrenia: a small cross-sectional study using Olink proteomics analysis

BACKGROUND

Cognitive impairment is a core symptom of schizophrenia. Metabolic abnormalities impact cognition, and although the influence of blood lipids on cognition has been documented, it remains unclear. We conducted a small cross-sectional study to investigate the relationship between blood lipids and cognition in patients with stable-phase schizophrenia. Using Olink proteomics, we explored the potential mechanisms through which blood lipids might affect cognition from an inflammatory perspective.

METHODS

A total of 107 patients with stable-phase schizophrenia and cognitive impairment were strictly included. Comprehensive data collection included basic patient information, blood glucose, blood lipids, and body mass index. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA) and the MATRICS Consensus Cognitive Battery (MCCB). After controlling for confounding factors, we identified differential metabolic indicators between patients with mild and severe cognitive impairment and conducted correlation and regression analyses. Furthermore, we matched two small sample groups of patients with lipid metabolism abnormalities and used Olink proteomics to analyze inflammation-related differential proteins, aiming to further explore the association between lipid metabolism abnormalities and cognition.

RESULTS

The proportion of patients with severe cognitive impairment (SCI) was 34.58%. Compared to patients with mild cognitive impairment (MCI), those with SCI performed worse in the Attention/Alertness (t = 2.668, p = 0.009) and Working Memory (t = 2.496, p = 0.014) cognitive dimensions. Blood lipid metabolism indicators were correlated with cognitive function, specifically showing that higher levels of TG (r = -0.447, p < 0.001), TC (r = -0.307, p = 0.002), and LDL-C (r = -0.607, p < 0.001) were associated with poorer overall cognitive function. Further regression analysis indicated that TG (OR = 5.578, P = 0.003) and LDL-C (OR = 5.425, P = 0.001) may be risk factors for exacerbating cognitive impairment in individuals with stable-phase schizophrenia. Proteomics analysis revealed that, compared to individuals with stable-phase schizophrenia and normal lipid metabolism, those with hyperlipidemia had elevated levels of 10 inflammatory proteins and decreased levels of 2 inflammatory proteins in plasma, with these changes correlating with cognitive function. The differential proteins were primarily involved in pathways such as cytokine-cytokine receptor interaction, chemokine signaling pathway, and IL-17 signaling pathway.

CONCLUSION

Blood lipids are associated with cognitive function in individuals with stable-phase schizophrenia, with higher levels of TG, TC, and LDL-C correlating with poorer overall cognitive performance. TG and LDL-C may be risk factors for exacerbating cognitive impairment in these patients. From an inflammatory perspective, lipid metabolism abnormalities might influence cognition by activating or downregulating related proteins, or through pathways such as cytokine-cytokine receptor interaction, chemokine signaling pathway, and IL-17 signaling pathway.

Whey protein powder with milk fat globule membrane attenuates Alzheimer's disease pathology in 3×Tg-AD mice by modulating neuroinflammation through the peroxisome proliferator-activated receptor γ signaling pathway

Whey protein powder (PP), which is mainly derived from bovine milk, is rich in milk fat globule membrane (MFGM). The MGFM has been shown to play a role in promoting neuronal development and cognition in the infant brain. However, its role in Alzheimer's disease (AD) has not been elucidated. Here, we showed that the cognitive ability of 3×Tg-AD mice (a triple-transgenic mouse model of AD) could be improved by feeding PP to mice for 3 mo. In addition, PP ameliorated amyloid peptide deposition and tau hyperphosphorylation in the brains of AD mice. We found that PP could alleviate AD pathology by inhibiting neuroinflammation through the peroxisome proliferator-activated receptor γ (PPARγ)-nuclear factor-κB signaling pathway in the brains of AD mice. Our study revealed an unexpected role of PP in regulating the neuroinflammatory pathology of AD in a mouse model.

DNA methylation signatures in Blood DNA of Hutchinson-Gilford Progeria syndrome

Hutchinson-Gilford Progeria Syndrome (HGPS) is an extremely rare genetic disorder caused by mutations in the LMNA gene and characterized by premature and accelerated aging beginning in childhood. In this study, we performed the first genome-wide methylation analysis on blood DNA of 15 patients with progeroid laminopathies using Infinium Methylation EPIC arrays including 8 patients with classical HGPS. We could observe DNA methylation alterations at 61 CpG sites as well as 32 significant regions following a 5 Kb tiling analysis. Differentially methylated probes were enriched for phosphatidylinositol biosynthetic process, phospholipid biosynthetic process, sarcoplasm, sarcoplasmic reticulum, phosphatase regulator activity, glycerolipid biosynthetic process, glycerophospholipid biosynthetic process, and phosphatidylinositol metabolic process. Differential methylation analysis at the level of promoters and CpG islands revealed no significant methylation changes in blood DNA of progeroid laminopathy patients. Nevertheless, we could observe significant methylation differences in classic HGPS when specifically looking at probes overlapping solo-WCGW partially methylated domains. Comparing aberrantly methylated sites in progeroid laminopathies, classic Werner syndrome, and Down syndrome revealed a common significantly hypermethylated region in close vicinity to the transcription start site of a long non-coding RNA located anti-sense to the Catenin Beta Interacting Protein 1 gene (CTNNBIP1). By characterizing epigenetically altered sites, we identify possible pathways/mechanisms that might have a role in the accelerated aging of progeroid laminopathies.