Project description:General anaesthesia, especially sevoflurane inhalation anaesthesia, is an independent risk factor for postoperative cognitive dysfunction. However, the molecular mechanism by which sevoflurane inhalation alters postoperative cognitive function remains unclear.
Project description:(1) Background: Weaning is a challenging and stressful event in the pig's life, which disrupts physiological balance and induces oxidative stress. Microbiota play a significant role during the weaning process in piglets. Therefore, this study aimed to investigate key gut microbiota and metabolites associated with weaning stress in piglets. (2) Methods: A total of ten newborn piglet littermates were randomly assigned to two groups: S (suckling normally) and W (weaned at 21 d; all euthanized at 23 d). Specimens of the cecum were dehydrated with ethanol, cleared with xylene, embedded in paraffin, and cut into 4 mm thick serial sections. After deparaffinization, the sections were stained with hematoxylin and eosin (H&E) for morphometric analysis. Cecal metagenomic and liver LC-MS-based metabolomics were employed in this study. Statistical comparisons were performed by a two-tailed Student's t-test, and p < 0.05 indicated statistical significance. (3) Results: The results showed that weaning led to intestinal morphological damage in piglets. The intestinal villi of suckling piglets were intact, closely arranged in an orderly manner, and finger-shaped, with clear contours of columnar epithelial cells. In contrast, the intestines of weaned piglets showed villous atrophy and shedding, as well as mucosal bleeding. Metagenomics and metabolomics analyses showed significant differences in composition and function between suckling and weaned piglets. The W piglets showed a decrease and increase in the relative abundance of Bacteroidetes and Proteobacteria (p < 0.05), respectively. The core cecal flora in W piglets were Campylobacter and Clostridium, while those in S piglets were Prevotella and Lactobacillus. At the phylum level, the relative abundance of Bacteroidetes significantly decreased (p < 0.05) in weaned piglets, while Proteobacteria significantly increased (p < 0.05). Significant inter-group differences were observed in pathways and glycoside hydrolases in databases, such as the KEGG and CAZymes, including fructose and mannose metabolism, salmonella infection, antifolate resistance, GH135, GH16, GH32, and GH84. We identified 757 differential metabolites between the groups through metabolomic analyses-350 upregulated and 407 downregulated (screened in positive ion mode). In negative ion mode, 541 differential metabolites were identified, with 270 upregulated and 271 downregulated. Major differential metabolites included glycerophospholipids, histidine, nitrogen metabolism, glycine, serine, threonine, β-alanine, and primary bile acid biosynthesis. The significant differences in glycine, serine, and threonine metabolites may be potentially related to dysbiosis caused by weaning stress. Taken together, the identification of microbiome and metabolome signatures of suckling and weaned piglets has paved the way for developing health-promoting nutritional strategies, focusing on enhancing bacterial metabolite production in early life stages.
Project description:Gut microbiota of higher vertebrates is host-specific. The number and diversity of the organisms residing within the gut ecosystem are defined by physiological and environmental factors, such as host genotype, habitat, and diet. Recently, culture-independent sequencing techniques have added a new dimension to the study of gut microbiota and the challenge to analyze the large volume of sequencing data is increasingly addressed by the development of novel computational tools and methods. Interestingly, gut microbiota maintains a constant relative abundance at operational taxonomic unit (OTU) levels and altered bacterial abundance has been associated with complex diseases such as symptomatic atherosclerosis, type 2 diabetes, obesity, and colorectal cancer. Therefore, the study of gut microbial population has emerged as an important field of research in order to ultimately achieve better health. In addition, there is a spontaneous, non-linear, and dynamic interaction among different bacterial species residing in the gut. Thus, predicting the influence of perturbed microbe-microbe interaction network on health can aid in developing novel therapeutics. Here, we summarize the population abundance of gut microbiota and its variation in different clinical states, computational tools available to analyze the pyrosequencing data, and gut microbe-microbe interaction networks.
Project description:Postoperative cognitive dysfunction (POCD) is one of the severe complications inducing low life quality and high mortality after surgery, especially in elderly patients.Here we probed differentially expressed circRNAs using microarray assay in POCD patients, aiming to find potential key circRNAs related to the occurrence of POCD. Subsequently, ten dysregulated circRNAs were confirmed via quantitative real-time polymerase chain reaction (qRT-PCR) in 10 paired samples. Then, Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed to probe the vital functions of dysregulated genes.
Project description:Here we report metagenomic sequencing data in gut microbiota of autism spectrum disorders (ASD) compared with healthy volunteers (30 for ASD children and 30 for healthy controls, respectively). The genes changed in autistic subjects involved 1,312,364 analytes that compare to 1,335,835 analytes in healthy controls. The number of taxa in autistic subjects were significantly increased as compared to the healthy controls based on the phylum and genus level (P = 0.001). However, the number of species were significantly decreased in autistic subjects (P = 0.001).
Project description:Postoperative cognitive dysfunction (POCD) is a common complication after cardiac surgery. Numerous evidence suggest that dysregulation of lipid metabolism is associated with cognitive impairment; however, its precise role in the development of POCD is still obscure. In this study, we established a cardiopulmonary bypass (CPB) model in rats and employed the Barnes maze to assess cognitive function, selecting POCD rats for subsequent experimentation. Utilizing mass spectrometry imaging, we detected plenty of lipids accumulates within the hippocampal CA1in the POCD group. Immunofluorescence staining revealed a significant reduction in the fluorescence intensity of calcium-independent phospholipases A2 (iPLA2) in the POCD group compared to the control, while serine palmitoyl transferase (SPT) was markedly increased in the POCD group. Transmission electron microscopy revealed that the number of synapses in hippocampal CA1decreased significantly and postsynaptic density became thinner in POCD group. Furthermore, after reversing the metabolic disorders of iPLA2 and SPT in the rat brain with docosahexaenoic acid and myriocin, the incidence of POCD after CPB was significantly reduced and the disrupted lipid metabolism in the hippocampus was also normalized. These findings may offer a novel perspective for exploring the etiology and prevention strategies of POCD after CPB.
Project description:Postoperative cognitive dysfunction (POCD) is a common complication following anesthesia and surgery that might lead to a decline in learning and memory. Oxidative stress damage is one of the pathogenic mechanisms underlying POCD. Recent studies had shown that the integrated stress response (ISR) is closely related to oxidative stress. The core response of the ISR is phosphorylation of eIF2α. Various cellular stress stimuli trigger activation of eIF2α kinases, thus causing phosphorylation of eIF2α. ISR is associated with many neurodegenerative diseases; however, the relationship between POCD and ISR has not been defined. In the present study, the tibias in 4-month-old male C57BL/6 mice were fractured under isoflurane anesthesia to establish the POCD animal model. Cognitive function was assessed by fear conditioning tests and the Y-maze from 3 to 14 days post-surgery. Western blot was used to determine the levels of PeIF2α, eIF2α, ATF4, GADD34, CHOP, BDNF, proBDNF, and p-NR2B expression. The levels of reactive oxygen species (ROS), superoxide dismutase (SOD), and malondialdehyde (MDA) were measured to determine oxidative stress in hippocampal tissues. After tibial fracture surgery in mice, the hippocampus had increased levels of PeIF2α, ATF4, GADD34, and CHOP protein, ROS-positive cells, and average fluorescence intensity, SOD activity was decreased, and the MDA level was increased. The ISR inhibitor, ISRIB, reduced the levels of PeIF2α, ATF4, GADD34, and CHOP protein, and alleviated oxidative stress in the hippocampus of POCD mice. Moreover, ISRIB ameliorated cognitive dysfunction in POCD mice. Our findings suggested that targeting ISR may represent an effective approach to combat POCD.
Project description:Diabetes-associated cognitive decline (DACD), one of the complications of type 2 diabetes (T2DM), correlates significantly with the disorder in glycolipid metabolism, insulin/leptin resistance, and accumulation of β-amyloid (Aβ). Although gut microbiota transplantation (GMT), a novel non-invasive physiotherapy strategy, has been a promising intervention to alleviate the symptoms of T2DM, its protective effect on progressive cognitive decline remains elusive. Here, we transplanted the gut microbiota of healthy or cognitive decline donor rats into ZDF or LZ rats, and integrated microbiomics and metabolomics to evaluate the directional effect of the gut microbiota on the recipient rats. The basal metabolism phenotype changed in ZDF rats instead of in LZ rats. One possible mechanism is that the microbiota and metabolites alter the structure of the intestinal tract, stimulate the brain insulin and leptin signaling pathways, and regulate the deposition of Aβ in the brain. It is worth noting that 10 species of genera, such as Parabacteroides, Blautia, and Lactobacillus, can regulate 20 kinds of metabolites, such as propanoic acid, acetic acid, and citramalic acid, and having a significant improvement on the cognitive behavior of ZDF rats. In addition, the correlation analysis indicated the gut microbiota and metabolites are highly associated with host phenotypes affected by GMT. In summary, our study indicates that altering the microbiota-gut-brain axis by reshaping the composition of gut microbiota is a viable strategy that has great potential for improving cognitive function and combatting DACD.
Project description:Hepatectomy is a common clinical procedure for the treatment of many liver diseases, and the successful recovery of a patient's liver metabolism and function after surgery is crucial for a good prognosis. The objective of this study was to elucidate the metabolic response to hepatectomy using high-throughput sequencing analysis of 16S rRNA gene, metabolomics, and proteomics data. Fecal and serum samples from beagle dogs were collected on day 0 (LH0), day 7 (LH7), and day 28 (LH28) after laparoscopic partial hepatectomy. Liver tissue samples were taken on LH0 and LH7. Dysbiosis in the fecal microbiota was explored, and host-microbiome interactions based on global metabolic and protein profiles and inflammatory processes were determined. Results showed that the relative abundance of Allobaculum and Turicibacter was decreased and that of Escherichia-Shigella was increased after hepatectomy (P < 0.05); the phenylalanine, tyrosine, and tryptophan biosynthetic pathway, along with the phenylalanine and aminoacyl-tRNA biosynthetic pathway, was significantly associated with liver injury. The serum metabolites l-phenylalanine and l-arginine were useful as biomarkers, and the fecal metabolite l-threonine was a signature target monitor for liver recovery. The proteomics profile revealed 412 significantly different proteins and further highlighted two key signaling pathways (mitogen-activated protein kinase [MAPK] and peroxisome proliferator-activated receptor [PPAR]) involved in the response to liver injury. We systematically explored the metabolic mechanism of liver injury and recovery, providing new insights into effective ways to promote recovery after hepatectomy and improve liver function and long-term survival. These fundamental studies on hepatectomy will provide the basis for future advances in treatment and recovery from common liver diseases. IMPORTANCE As the largest parenchymal organ, the liver is a target for bacterial and viral infections, nonalcoholic fatty liver disease (NAFLD), cirrhosis, cancer, and many other diseases, constituting a serious worldwide problem. The treatment for many of these diseases involves hepatectomy. Here, we show that aberrant inflammatory processes after hepatectomy of the liver as reflected in the association between liver metabolism and gut microbiota create a grave risk. This study investigated the mechanisms of gut microbiota and host metabolism involved in liver injury and recovery after hepatectomy, using proteomics to reveal the mechanisms of postoperative liver injury and a comprehensive multi-omics approach to identify changes in metabolism after hepatectomy.