Constructing a prognostic risk model for Alzheimer's disease based on ferroptosis.

Introduction: The aim of this study is to establish a prognostic risk model based on ferroptosis to prognosticate the severity of Alzheimer's disease (AD) through gene expression changes. Methods: The GSE138260 dataset was initially downloaded from the Gene expression Omnibus database. The ssGSEA algorithm was used to evaluate the immune infiltration of 28 kinds of immune cells in 36 samples. The up-regulated immune cells were divided into Cluster 1 group and Cluster 2 group, and the differences were analyzed. The LASSO regression analysis was used to establish the optimal scoring model. Cell Counting Kit-8 and Real Time Quantitative PCR were used to verify the effect of different concentrations of Aß1-42 on the expression profile of representative genes in vitro. Results: Based on the differential expression analysis, there were 14 up-regulated genes and 18 down-regulated genes between the control group and Cluster 1 group. Cluster 1 and Cluster 2 groups were differentially analyzed, and 50 up-regulated genes and 101 down-regulated genes were obtained. Finally, nine common differential genes were selected to establish the optimal scoring model. In vitro, CCK-8 experiments showed that the survival rate of cells decreased significantly with the increase of Aß1-42 concentration compared with the control group. Moreover, RT-qPCR showed that with the increase of Aß1-42 concentration, the expression of POR decreased first and then increased; RUFY3 was firstly increased and then decreased. Discussion: The establishment of this research model can help clinicians make decisions on the severity of AD, thus providing better guidance for the clinical treatment of Alzheimer's disease.

Identifying Immune Cell Infiltration and Effective Diagnostic Biomarkers in Lung Adenocarcinoma by Comprehensive Bioinformatics Analysis and In Vitro Study.

Family with sequence similarity 72B (FAM72B) has been characterized in the regulation of neuronal development. Nevertheless, the prognostic value of FAM72B expression and its function in the immune microenvironment of lung adenocarcinoma (LUAD) currently remains elusive. In this study, by adopting bioinformatics methodology and experimental verification, we found that FAM72B was upregulated in lung cancer tissues and cell lines, and a higher FAM72B level predicted an unfavorable clinical outcome in LUAD patients. The knockdown of FAM72B significantly inhibited cell proliferation, cell migration, and induced cell apoptosis in LUAD. The receiver operating characteristic curve suggested that FAM72B had a high predictive accuracy for the outcomes of LUAD. Kyoto Encyclopedia of Genes and Genomes and Gene Set Enrichment Analyses confirmed that FAM72B-related genes were involved in cell proliferation and immune-response signaling pathway. Moreover, upregulated FAM72B expression was significantly associated with immune cell infiltration in the LUAD tumor microenvironment. Meanwhile, a potential ceRNA network was constructed to identify the lncRNA-AL360270.2/TMPO-AS1/AC125807.2/has-let-7a/7b/7c/7e/7f/FAM72B regulatory axis that regulates FAM72B overexpression in LUAD and is associated with a poor prognosis. We also confirmed that AL360270.2, TMPO-AS1, and AC125807.2 were significantly upregulated in LUAD cell lines than in human bronchial epithelial cells. In conclusion, FAM72B may serve as a novel biomarker in predicting the clinical prognosis and immune status for lung adenocarcinoma.

Metformin Mitigates Sepsis-Related Neuroinflammation via Modulating Gut Microbiota and Metabolites.

Gut microbiota affects the functions of brains. However, its mechanism in sepsis remains unclear. This study evaluated the effect of metformin on ameliorating sepsis-related neurodamage by regulating gut microbiota and metabolites in septic rats. Cecal ligation and puncture (CLP) was used to establish the sepsis-related neurodamage animal models. Metformin therapy by gavage at 1 h after CLP administration was followed by fecal microbiota transplantation (FMT) to ensure the efficacy and safety of metformin on the sepsis-related neurodamage by regulating gut microbiota. The gut microbiota and metabolites were conducted by 16S rRNA sequencing and liquid chromatography-tandem mass spectrometry metabolomic analysis. The brain tissue inflammation response was analyzed by histopathology and reverse transcription-polymerase chain reaction (RT-PCR). This study reported brain inflammatory response, hemorrhage in sepsis-related neurodamage rats compared with the control group (C group). Surprisingly, the abundance of gut microbiota slightly increased in sepsis-related neurodamage rats than C group. The ratio of Firmicutes/Bacteroidetes was significantly increased in the CLP group than the C group. However, no difference was observed between the CLP and the metformin-treated rats (MET group). Interestingly, the abundance of Escherichia_Shigella increased in the MET group than the C and CLP groups, while Lactobacillaceae abundance decreased. Furthermore, Prevotella_9, Muribaculaceae, and Alloprevotella related to short-chain fatty acids production increased in the sepsis-related neurodamage of metformin-treated rats. Additionally, Prevotella_9 and Muribaculaceae correlated positively to 29 metabolites that might affect the inflammatory factors in the brain. The FMT assay showed that metformin improved sepsis-related neurodamage by regulating the gut microbiota and metabolites in septic rats. The findings suggest that metformin improves the sepsis-related neurodamage through modulating the gut microbiota and metabolites in septic rats, which may be an effective therapy for patients with sepsis-related neurodamage.

[Analysis of the changes in intestinal microecology in the early stage of sepsis rat based on 16S rDNA sequencing].

OBJECTIVE: To investigate the changes of intestinal microecology in the early stage of sepsis rat model by 16S rDNA sequencing. METHODS: Sixty male Sprague-Dawley (SD) rats were randomly divided into cecal ligation and puncture (CLP) group and sham operation group (Sham group), with 30 rats in each group. In the CLP group, sepsis rat model was reproduced by CLP method; the rats in the Sham group only underwent laparotomy without CLP. At 24 hours after the operation, the intestinal feces and serum samples of 8 rats in each group were collected. The survival rate of the rest rats was observed until the 7th day. The level of serum tumor necrosis factor-α (TNF-α) was detected by enzyme-linked immunosorbent assay (ELISA). Intestinal feces were sequenced by 16S rDNA sequencing technology. The operational taxonomic unit (OTU) data obtained after sequence comparison and clustering was used for α diversity and ß diversity analysis, principal coordinate analysis and linear discriminant analysis effect size analysis (LEfSe) to observe the changes of intestinal microecology in early sepsis rats and excavate the marker flora. RESULTS: At 24 hours after the reproduction of the model, the rats in the CLP group showed shortness of breath, scattered hair and other manifestations, and the level of serum TNF-α increased significantly as compared with that in the Sham group (ng/L: 43.95±9.05 vs. 11.08±3.27, P < 0.01). On the 7th day after modeling, the cumulative survival rate of the Sham group was 100%, while that of the CLP group was 31.82%. Diversity analysis showed that there was no significant difference in α diversity parameter between the Sham group and the CLP group (number of species: 520.00±52.15 vs. 492.25±86.61, Chao1 richness estimator: 707.25±65.69 vs. 668.93±96.50, Shannon index: 5.74±0.42 vs. 5.79±0.91, Simpson index: 0.93±0.03 vs. 0.94±0.05, all P > 0.05). However, the ß diversity analysis showed that the difference between groups was greater than that within groups whether weighted according to OTU or not (abundance weighted matrix: R = 0.23, P = 0.04; abundance unweighted matrix: R = 0.32, P = 0.01). At the phylum level, the abundance of Proteobacteria and Candidatus_sacchari in the CLP group increased significantly as compared with the Sham group [18.100% (15.271%, 26.665%) vs. 6.974% (2.854%, 9.764%), 0.125% (0.027%, 0.159%)% vs. 0.018% (0.008%, 0.021%), both P < 0.05]. At the genus level, the abundance of opportunistic pathogen including Helicobacter, Ruthenium, Streptococcus, Clostridium XVIII in the CLP group was significantly higher than that in the Sham group [5.090% (1.812%, 6.598%) vs. 0.083% (0.034%, 0.198%), 0.244% (0.116%, 0.330%) vs. 0.016% (0.008%, 0.029%), 0.006% (0.003%, 0.010%) vs. 0.001% (0%, 0.003%), 0.094% (0.035%, 0.430%) vs. 0.007% (0.003%, 0.030%), all P < 0.05], and the abundance of probiotics such as Alloprevotella and Romboustia was significantly lower than that in the Sham group [7.345% (3.662%, 11.546%) vs. 22.504% (14.403%, 26.928%), 0.113% (0.047%, 0.196%) vs. 1.229% (0.809%, 2.29%), both P < 0.01]. LEfSe analysis showed that the probiotics belonging to Firmicutes were significantly enriched in the Sham group, and Romboustia was the most significantly enriched species. Opportunistic pathogens such as Helicobacter, Streptococcus and Clostridium XVIII were significantly enriched in the CLP group, Helicobacter_NGSU_ 2015 was the most significantly enriched species. CONCLUSIONS: In the early stage of sepsis, the intestinal microbiota structure of rats is significantly changed, which mainly shows that the abundance of Alloprevotella and other probiotics is significantly reduced, while that of Helicobacter and other opportunistic pathogens is significantly increased.

Metformin attenuated sepsis-associated liver injury and inflammatory response in aged mice.

Sepsis-associated liver injury is with poor survival in intensive care units. Metformin is well known for its therapeutic effects; however, its impact on treating liver injury due to sepsis remains poorly understood. This study investigated the therapeutic effects of metformin on aged mice suffering from sepsis-associated liver injury. Male C57BL/6 J mice aged (18-19 months) were divided into 3 groups: 1) intraperitoneal injection of sterile normal saline (C group), 12.5 mg/kg lipopolysaccharide (LPS) to induce sepsis-associated liver injury (LPS group), and 25 mg/kg metformin (MET) at 1 h after LPS injection (MET group). After 24 h, blood samples and liver tissue were collected for biochemical analysis. Histological assays revealed significantly elevated inflammatory infiltration and apoptosis in the liver, while metformin was found to relieve these aberrant features. The percentage of apoptotic cells decreased after metformin treatment (P < 0.05). Additionally, MET group had significantly reduced plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels compared to the LPS group (P < 0.05). Furthermore, in the MET group, the mRNA levels of chemokines and inflammatory factors, TNF-α, IL-6, caspase-1, decreased markedly (P < 0.05). Metformin notably reversed the decreased phosphorylated AMP-activated protein kinase (p-AMPK) and PGC-1α expressions in the liver of septic rats. Metformin also inhibited PDK1, HIF-1α expression, including downstream inflammatory mediators, HMGB1 and TNF-α. Metformin attenuated inflammation and liver injury in septic aged mice. Most importantly, we report the effect of metformin on liver injury via the AMPK-PGC1α axis in septic aged mice for the first time.

Corrigendum: Corticosteroids for Treating Sepsis in Adult Patients: A Systematic Review and Meta-Analysis.

[This corrects the article DOI: 10.3389/fimmu.2021.709155.].

Corticosteroids for Treating Sepsis in Adult Patients: A Systematic Review and Meta-Analysis.

Objective: Corticosteroids are a common option used in sepsis treatment. However, the efficacy and potential risk of corticosteroids in septic patients have not been well assessed. This review was performed to assess the efficacy and safety of corticosteroids in patients with sepsis. Methods: PubMed, Embase, and Cochrane library databases were searched from inception to March 2021. Randomized controlled trials (RCTs) that evaluated the effect of corticosteroids on patients with sepsis were included. The quality of outcomes in the included articles was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation methodology. The data were pooled by using risk ratio (RR) and mean difference (MD). The random-effects model was used to evaluate the pooled MD or RR and 95% confidence intervals (CIs). Results: Fifty RCTs that included 12,304 patients with sepsis were identified. Corticosteroids were not associated with the mortality in 28-day (RR, 0.94; 95% CI, 0.87-1.02; evidence rank, moderate) and long-term mortality (>60 days) (RR, 0.96; 95% CI, 0.88-1.05) in patients with sepsis (evidence rank, low). However, corticosteroids may exert a significant effect on the mortality in the intensive care unit (ICU) (RR, 0.9; 95% CI, 0.83-0.97), in-hospital (RR, 0.9; 95% CI, 0.82-0.99; evidence rank, moderate) in patients with sepsis or septic shock (evidence rank, low). Furthermore, corticosteroids probably achieved a tiny reduction in the length of hospital stay and ICU. Corticosteroids were associated with a higher risk of hypernatremia and hyperglycemia; furthermore, they appear to have no significant effect on superinfection and gastroduodenal bleeding. Conclusions: Corticosteroids had no significant effect on the 28-day and long-term mortality; however, they decreased the ICU and hospital mortality. The findings suggest that the clinical corticosteroids may be an effective therapy for patients with sepsis during the short time. Systematic Review Registration: https://inplasy.com/wp-content/uploads/2021/05/INPLASY-Protocol-1074-4.pdf.