Although lipopolysaccharides (LPS) have been used to establish animal models of memory loss akin to what is observed in Alzheimer’s disease (AD), the exact mechanisms involved have not been substantiated. In this study, we established an animal model of learning and memory impairment induced by LPS and explored the biological processes and pathways involved. Mice were continuously intraperitoneally injected with LPS for 7 days. Learning- and memory-related behavioral performance and the pathological processes involved were assessed using the Morris water maze test and immunostaining, respectively. We detected comprehensive expression of C1q, C3, microglia, and their regulatory cytokines in the hippocampus. After 7 days of LPS administration, we were able to observe LPS-induced learning and memory impairment in the mice, which was attributed to neural impairment and synapse loss in the hippocampus. We elucidated that the immune system was activated, with the classical complement pathway and microglial phagocytosis being involved in the synapse loss. This study demonstrates that an LPS-injected mouse can serve as an early memory impairment model for studies on anti-AD drugs.

Human neurons function over an entire lifetime, yet the molecular mechanisms which perform their functions and protecting against neurodegenerative disease during aging are still elusive. Here, we conducted a systematic study on the human brain aging by using the weighted gene correlation network analysis (WGCNA) method to identify meaningful modules or representative biomarkers for human brain aging. Significantly, 19 distinct gene modules were detected based on the dataset GSE53890; among them, six modules related to the feature of brain aging were highly preserved in diverse independent datasets. Interestingly, network feature analysis confirmed that the blue modules demonstrated a remarkably correlation with human brain aging progress. Besides, the top hub genes including PPP3CB, CAMSAP1, ACTR3B, and GNG3 were identified and characterized by high connectivity, module membership, or gene significance in the blue module. Furthermore, these genes were validated in mice of different ages. Mechanically, the potential regulators of blue module were investigated. These findings highlight an important role of the blue module and its affiliated genes in the control of normal brain aging, which may lead to potential therapeutic interventions for brain aging by targeting the hub genes.

Numerous researches supported that non-alcoholic fatty liver disease (NAFLD) was an emerging problem associated with increased visceral adiposity (obesity), diabetes and related metabolic disorders. Huang-Qi San (HQS) is composed of three traditional Chinese medicines (Astragali Radix, Pueraria Radix and Cortex Mori Radicis) with a weight ratio of 1:2:1. HQS has been reported to be effective in improving glucose-lipid metabolism, but its underlying mechanism on NAFLD has not been fully understood. The purpose of the present study was to assess the protective effects of HQS on obesity-induced hepatic steatosis in rats fed with high fat diet (HFD). Our data revealed that administration of HQS (1.2 and 2.4 g/kg body weight) resulted in significant reduction in body weight (BW) and organs coefficients of visceral fat. The full-Body CT scan demonstrated that HQS reduced liver fat ratio, visceral and subcutaneous fat mass in a dose-dependent manner. Additionally, HQS decreased plasma TC, TG, FFA and FABP4 levels, normalized glucose and insulin levels, and improved the glucose tolerance. Pathological examination showed that HQS alleviated hepatic steatosis and reduced the cell size of epididymal visceral adipose tissue. Hepatic lipid accumulation was also reduced by HQS treatment compared with HFD fed rats. RNA-Seq analysis combining with qPCR demonstrated that the mRNA expression of some important glucose and lipid metabolism-related genes including Acat2, Apoc4, Bhmt, Cyp3a62, Cyp51, Egln3 (Phd3), Fads1, Fads2, Gnmt, Hmgcs1 and Pemt, were significantly changed by HQS treatment. Taken together, these results suggested that HQS had beneficial effects on glucose-lipid metabolism and hepatic steatosis, and its mechanism might be related to the functions of the genes in regulating glucose and lipid metabolism.

This study investigated the neuroprotective effects of methyl 3,4-dihydroxybenzoate (MDHB) against t-butyl hydroperoxide (TBHP) induced oxidative damage in SH-SY5Y (human neuroblastoma cells) and the underlying mechanisms. SH-SY5Y were cultured in DMEM + 10% FBS for 24 h and pretreated with different concentrations of MDHB or N-acetyl-l-cysteine (NAC) for 4 h prior to the addition of 40 μM TBHP for 24 h. Cell viability was analyzed using the methylthiazolyltetrazolium (MTT) and lactate dehydrogenase (LDH) assays. An annexin V-FITC assay was used to detect cell apoptosis rates. The 2′,7′-dichlorofluorescin diacetate (DCFH-DA) assay was used to determine intracellular ROS levels. The activities of antioxidative enzymes (GSH-Px and SOD) were measured using commercially available kits. The oxidative DNA damage marker 8-OHdG was detected using ELISA. Western blotting was used to determine the expression of Bcl-2, Bax, caspase 3, p-Akt and Akt proteins in treated SH-SY5Y cells. Our results showed that MDHB is an effective neuroprotective compound that can mitigate oxidative stress and inhibit apoptosis in SH-SY5Y cells.