S100a8 silencing attenuates inflammation, oxidative stress and apoptosis in BV2 cells induced by oxygen‑glucose deprivation and reoxygenation by upregulating GAB1 expression

Study on the involvement of microglial S100A8 in neuroinflammation and microglia activation during migraine attacks

BACKGROUND

Microglia is the primary source of inflammatory factors during migraine attacks. This study aims to investigate the role of microglia related genes (MRGs) in migraine attacks.

METHODS

The RNA sequencing results of migraineurs and the panglaodb database were used to obtain differentially expressed genes (DEGs) in migraine related to microglia. A migraine rat model was established for validating and localizing of the MRGs, and subsequent screening for target genes was conducted. A shRNA was designed to interference the expression of target genes and administered into the trigeminal ganglion (TG) of rats. Pain sensitivity in rats was evaluated via the hot water tail-flick (HWTF) and formalin-induced pain (FIP) experiments. ELISA was used to quantify the levels of inflammatory cytokines and CGRP. WB and immunofluorescence assays were applied to detect the activation of microglia.

RESULTS

A total of five DEGs in migraine related to microglia were obtained from RNA sequencing and panglaodb database. Animal experiments showed that these genes expression were heightened in the TG and medulla oblongata (MO) of migraine rats. The gene S100A8 co-localized with microglia in both TG and MO. The HWTF and FIP experiments demonstrated that interference with S100A8 alleviated the sense of pain in migraine rats. Moreover, the levels of TNFα, IL-1β, IL-6, and CGRP in the TG and MO of rats in the model rats were increased, and the expression of microglia markers IBA-1, M1 polarization markers CD86 and iNOS was upregulated. Significantly, interference with S100A8 reversed these indicators.

CONCLUSION

Interference with S100A8 in microglia increased the pain threshold during migraine attacks, and inhibited neuroinflammation and microglia activation.

Proteomics in Patients with Fibromyalgia Syndrome: A Systematic Review of Observational Studies

PURPOSE OF REVIEW

Fibromyalgia syndrome (FMS) is a disease of unknown pathophysiology, with the diagnosis being based on a set of clinical criteria. Proteomic analysis can provide significant biological information for the pathophysiology of the disease but may also reveal biomarkers for diagnosis or therapeutic targets. The present systematic review aims to synthesize the evidence regarding the proteome of adult patients with FMS using data from observational studies.

RECENT FINDINGS

An extensive literature search was conducted in MEDLINE/PubMed, CENTRAL, and clinicaltrials.gov from inception until November 2022. The study protocol was published in OSF. Two independent reviewers evaluated the studies and extracted data. The quality of studies was assessed using the modified Newcastle-Ottawa scale adjusted for proteomic research. Ten studies fulfilled the protocol criteria, identifying 3328 proteins, 145 of which were differentially expressed among patients with FMS against controls. The proteins were identified in plasma, serum, cerebrospinal fluid, and saliva samples. The control groups included healthy individuals and patients with pain (inflammatory and non-inflammatory). The most important proteins identified involved transferrin, α-, β-, and γ-fibrinogen chains, profilin-1, transaldolase, PGAM1, apolipoprotein-C3, complement C4A and C1QC, immunoglobin parts, and acute phase reactants. Weak correlations were observed between proteins and pain sensation, or quality of life scales, apart from the association of transferrin and a2-macroglobulin with moderate-to-severe pain sensation. The quality of included studies was moderate-to-good. FMS appears to be related to protein dysregulation in the complement and coagulation cascades and the metabolism of iron. Several proteins may be dysregulated due to the excessive oxidative stress response.

Semaglutide ameliorates obesity-induced cardiac inflammation and oxidative stress mediated via reduction of neutrophil Cxcl2, S100a8, and S100a9 expression

Obesity, which is driven by inflammation and oxidative stress, is a risk factor for cardiovascular disease. Semaglutide, a glucagon-like peptide-1 receptor agonist, is an antidiabetic drug with major effects on weight loss. In this study, single-cell transcriptomics was used to examine non-cardiomyocytes to uncover the mechanism of obesity-induced myocardial damage and the cardioprotective impact of semaglutide. We constructed obese mouse models and measured Tumor Necrosis Factor-α (TNF-α), Interleukin-6 (IL-6), Reactive Oxygen Species (ROS), and Malonic dialdehyde (MDA) levels in serum and heart tissue to determine the levels of inflammation and oxidative stress in obesity and the effect of semaglutide on these levels. Then, utilizing single-cell transcriptomes to screen for key cell populations and differentially expressed genes (DEGs), we assessed the effects of obesity and semaglutide on non-cardiac cells. Finally, a DEG localization analysis was performed to explore DEGs as well as cell types associated with inflammation and oxidative stress. Semaglutide reduced increased TNF-α, IL-6, ROS, and MDA levels in serum and cardiac tissues in obese mouse. Several genes are closely associated with inflammation and oxidative stress. Chemokine (C-X-C motif) ligand 2 (Cxcl2), S100 calcium binding protein A8 (S100a8), and S100 calcium binding protein A9 (S100a9), which were elevated in obesity but decreased following semaglutide treatment, were also expressed particularly in neutrophils. Finally, by decreasing neutrophil Cxcl2, S100a8, and S100a9 expressions, semaglutide may help to reduce cardiac inflammation and oxidative stress. Semaglutide significantly reduced body weight in obese mice as well as exerted anti-inflammatory and antioxidant effects possibly by inhibiting the expression of S100a8, S100a9, and Cxcl2 in neutrophils. These discoveries are expected to reveal new molecular mechanisms underlying obesity-related heart damage and semaglutide's cardioprotective properties.

The diagnostic value of calcium binding protein S100A8/A9 and S100A12 in acute pancreatitis

Background: S100A8/A9 and S100A12 which are the major calcium-binding proinflammatory proteins secreted by granulocytes, has been proposed to be related to distinct disease states of inflammatory origin. This study aims to explore the circulating levels of S100A8/A9 and S100A12 in acute pancreatitis (AP) and reveal their relationship with conventional inflammatory markers. Material and Method: Serum S100A8/A9 and S100A12 were determined in AP patients (male/female: 17/13) by using a specific enzyme-linked immunosorbent assay (ELISA) method at both onset and remission and in 30 healthy controls (male/female: 17/13). Results: Significantly higher S100A8/A9 and S100A12 levels were found in AP patients compared to healthy controls (p

Gut bacterial isoamylamine promotes age-related cognitive dysfunction by promoting microglial cell death

The intestinal microbiome releases a plethora of small molecules. Here, we show that the Ruminococcaceae metabolite isoamylamine (IAA) is enriched in aged mice and elderly people, whereas Ruminococcaceae phages, belonging to the Myoviridae family, are reduced. Young mice orally administered IAA show cognitive decline, whereas Myoviridae phage administration reduces IAA levels. Mechanistically, IAA promotes apoptosis of microglial cells by recruiting the transcriptional regulator p53 to the S100A8 promoter region. Specifically, IAA recognizes and binds the S100A8 promoter region to facilitate the unwinding of its self-complementary hairpin structure, thereby subsequently enabling p53 to access the S100A8 promoter and enhance S100A8 expression. Thus, our findings provide evidence that small molecules released from the gut microbiome can directly bind genomic DNA and act as transcriptional coregulators by recruiting transcription factors. These findings further unveil a molecular mechanism that connects gut metabolism to gene expression in the brain with implications for disease development.

Carnosol suppresses microglia cell inflammation and apoptosis through PI3K/AKT/mTOR signaling pathway

Ischemic stroke is the most common type of acute cerebrovascular disease. Carnosol is a polyphenol compound extracted from rosemary. This study aimed to explore the effects of carnosol on the oxygen-glucose deprivation (OGD) treated BV2 microglia cells. MTT and EdU assays were used to detect the cell viability and proliferation. Flow cytometry was conducted to measure the apoptosis rates. Additionally, the protein expression was determined by western blot. The inflammatory factors and antioxidant indexes were detected by corresponding kits. Carnosol promoted the proliferation and inhibited the apoptosis of the OGD treated BV2 cells. What's more, the protein expressions of PCNA and Bcl-2 were up-regulated, the Bax expression was down-regulated after carnosol treatment. In addition, carnosol decreased the levels of MDA, LPO, TNF-α, IL-1β and IL-6, and increased the levels of GSH, SOD, IL-4 and IL-10 in the OGD treated BV2 cells. Furthermore, the PI3K/AKT/mTOR signaling pathway was activated after carnosol treatment and inhibition of the PI3K/AKT/mTOR signaling pathway reversed the carnosol effects. Carnosol promotes the proliferation, inhibits the apoptosis, relieves the oxidative damage and inflammation of OGD treated cells through regulating the PI3K/AKT/mTOR signaling pathway.

Mechanism of METTL3-mediated m6A modification in depression-induced cognitive deficits

Depressive disorder (DD) is associated with N6-methyladenosine (m6A) hypermethylation. This study sought to explore the molecular mechanism of Methyltransferase-like 3 (METTL3) in cognitive deficits of chronic unpredictable mild stress (CUMS)-treated rats and provide novel targets for DD treatment. A DD rat model was established via CUMS treatment. Cognitive deficits were assessed via body weighing and behavioral tests. METTL3, microRNA (miR)-221-3p, pri-miR-221, GRB2-associated binding protein 1 (Gab1) expressions in hippocampal tissues were detected via RT-qPCR and Western blotting. m6A, DiGeorge syndrome critical region gene 8 (DGCR8)-bound pri-miR-221 and pri-miR-221 m6A levels were measured. The binding relationship between miR-221-3p and Gab1 was testified by dual-luciferase and RNA pull-down assays. Rescue experiments were designed to confirm the role of miR-221-3p and Gab1. METTL3 was highly expressed in CUMS rats, and silencing METTL3 attenuated cognitive deficits of CUMS rats. METTL3-mediated m6A modification facilitated processing and maturation of pri-miR-221 via DGCR8 to upregulate miR-221-3p. miR-221-3p targeted Gab1. miR-221-3p overexpression or Gab1 downregulation reversed the role of silencing METTL3 in CUMS rats. Overall, METTL3-mediated m6A modification facilitated processing and maturation of pri-miR-221 to upregulate miR-221-3p and then inhibit Gab1, thereby aggravating cognitive deficits of CUMS rats.

Plasma Calprotectin Is Predictive for Short-Term Functional Outcomes of Acute Ischemic Stroke

Background

Blood-based prognostic biomarkers of acute ischemic stroke (AIS) are limiting. Calprotectin is suggested to be involved in directing post-stroke inflammatory conditions. However, the pathological alteration of circulating calprotectin in AIS is yet to be thoroughly elucidated. Therefore, this study aimed to investigate the levels and clinical relevance of calprotectin in AIS.

Methods

This study recruited 271 patients with AIS within 24 h since symptom onset and 145 non-stroke healthy controls (HC) from February 1, 2018, to Dec 31, 2020. Patients were followed up for 2 weeks for observation of functional outcomes, as determined by the National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS). Plasma calprotectin concentrations were determined by ELISA.

Results

Plasma calprotectin concentrations were significantly higher in patients with AIS compared with controls [patients vs. control: median (IQR) 54.2 (39.01–99.04) vs. 50.04 (35.42–61.22), p < 0.001]. Besides, patients with poor prognosis, as defined by mRS ≥ 3, had significantly higher calprotectin levels than patients with good prognosis [poor prognosis patients vs. good prognosis patients: median (IQR) 61.99 (47.52–108) vs. 43.36 (33.39–60.2), p < 0.001]. Plasma calprotectin levels were positively associated with the disease severity of AIS, as reflected by infarction volume and NIHSS score at baseline. Furthermore, baseline calprotectin was found to be independently associated with poor prognosis [odds ratio (OR): 1.02, 95% CI: 1.01–1.03] and disease progression (OR: 1.03, 95% CI: 1.02–1.04) of AIS during a 2-week follow-up, with adjustment of possible confounding factors.

Conclusion

Plasma calprotectin is associated with short-term functional outcomes of AIS.

Bioinformatic Analysis of Crosstalk Between circRNA, miRNA, and Target Gene Network in NAFLD

Background: The majority of chronic liver disease is caused by non-alcoholic fatty liver disease (NAFLD), which is one of the highly prevalent diseases worldwide. The current studies have found that non-coding RNA (ncRNA) plays an important role in the NAFLD, but few studies on circRNA. In this study, genes, microRNA (miRNA), and circular RNA (circRNA) associated with NAFLD were found by bioinformatic methods, bringing a novel perspective for the prevention and treatment of NAFLD.

Methods: Expression data of GSE63067 was acquired from Gene Expression Omnibus (GEO) database. The liver samples were collected from the people diagnosed with NAFLD or not. Differentially expressed genes (DEGs) were obtained from the steatosis vs. the control group and non-alcoholic steatohepatitis (NASH) vs. the control group using the GEO2R online tool. The overlapping genes remained for further functional enrichment analysis and protein-protein interaction network analysis. MiRNAs and circRNAs targeting these overlapping DEGs were predicted from the databases. Finally, the GSE134146 dataset was used to verify the expression of circRNA.

Results: In summary, 228 upregulated and 63 downregulated differential genes were selected. The top 10 biological processes and relative signaling pathways of the upregulated differential genes were obtained. Also, ten hub genes were performed in the Protein-protein interaction (PPI) network. One hundred thirty-nine miRNAs and 902 circRNAs were forecast for the differential genes by the database. Ultimately, the crosstalk between hsa_circ_0000313, miR-6512-3p, and PEG10 was constructed.

Conclusion: The crosstalk of hsa_circ_0000313-hsa-miR-6512-3p-PEG10 and some related non-coding RNAs may take part in NAFLD’s pathogenesis, which could be the potential biomarkers of NAFLD in the future.