METTL3-mediated ANXA2 inhibition confers neuroprotection in ischemic stroke: Evidence from in vivo and in vitro studies.

Given the important role of m6A, the most common and reversible mRNA modification, in the pathogenesis of ischemic stroke, this study investigates the mechanisms of m6A methyltransferase METTL3 in neuronal damage in ischemic stroke. In silico analysis was used to pinpoint the expression of ANXA2, which was verified in clinical peripheral blood samples. SD rats were used for middle cerebral artery occlusion (MCAO) establishment. The experimental data suggested that T lymphocytes were increased in peripheral blood samples of ischemic stroke patients and MCAO rats. The MCAO rats were treated with anti-ANXA2 alone or combined with RP101075 (T lymphocyte infiltration inhibitor), followed by brain injury assessment. Oxygen-glucose deprivation/reoxygenation (OGD/R) was induced in primary cortical neurons, where shRNAs targeting ANXA2 or METTL3, or overexpression plasmids of METTL3 were introduced to verify the regulatory function for METTL3. Inhibition of T lymphocyte migration to the ischemic brain reduced brain injury in MCAO rats and neuronal damage in OGD/R-exposed neurons. Ablation of ANXA2 in T lymphocytes inhibited the migration of T lymphocytes to the ischemic brain and reduced neuronal damage. Mechanistically, METTL3 reduced ANXA2 expression in T lymphocytes through m6A modification and inhibited p38MAPK/MMP-9 pathway activation, exerting protective effects against neuronal damage in ischemic stroke. Overall, this study reveals the neuroprotective effects of METTL3-mediated ANXA2/p38MAPK/MMP-9 inhibition against ischemic stroke.

Introduction and comparision of three different fixation methods in the suprahepatic space in laparoscopy-assisted ventriculoperitoneal shunt for hydrocephalus.

Ventriculoperitoneal shunt (VPS) placement is the standard procedure in the management of hydrocephalus. The introduction of laparoscopy allows better visualization during the operation and a more reliable placement of the peritoneal terminal of the catheter, which significantly decreases postoperative obstruction and malposition rates. However, the fixation methods of the peritoneal terminal of the catheter have not been previously discussed. The indications, techniques, and complications were compared between conventional VPS and laparoscopy-guided VPS. Furthermore, same analyses were performed within the laparoscopy-guided VPS group subdivided by three different techniques of the fixation of the peritoneal terminal of catheter, including suture and ligature, titanium clip fixation, and subcutaneous fixation. A total of 137 patients with hydrocephalus who received VPS treatment was retrospectively studied, 85 of which were laparoscopy-guided, and 52 were not. The distal ends of the catheters were all placed in the suprahepatic space. At least one year (mean 28.6 months) follow-up was given postoperatively. The average duration of the whole operation was 45 min for suture and ligature, 40 min for titanium clip fixation, and 30 min for the subcutaneous fixation, respectively. Six patients (4.4%) had obstructive of the ventricular catheter in total. The success rates for the laparoscopy-assisted VPS procedure and the conventional VPS procedure were 87.1% (74/85) and 80.8% (42/52), respectively. Within subgroups of the laparoscopy-assisted VPS divided by fixation methods, the procedures were successful in 85.2% (23/27) of suture and ligation, 82.1% (23/28) of titanium clip fixation, and 93.3% (28/30) of subcutaneous fixation, respectively. Two patients had dislocated shunt tube in peritoneal end in laparoscopy group, all in the titanium clip fixation subgroups. The laparoscopy-assisted VPS insertion is an ideal shunt method for its effectiveness and lesser complication rate after operation. The subcutaneous fixation method of the peritoneal terminal of catheter might be the optimal fixation technique.

Function analysis of choline binding domains (CBDs) of LytA, LytC and CbpD in biofilm formation of Streptococcus pneumoniae.

Biofilm formation is an important strategy for the colonization of Streptococcus pneumoniae, which can increase the capacity to evade antibiotic and host immune stress. Extracellular choline-binding proteins (CBPs) are required for successful biofilm formation, but the function of extracellular CBPs in the process of biofilm formation is not fully understood. In this study, we tend to analyze the functions of LytA, LytC and CbpD in biofilm formation by in vitro studies with their choline-binding domains (CBDs). Biofilm formation of S. pneumoniae was enhanced when cultured in medium supplemented with CBD-C and CBD-D. Parallel assays with ChBp-Is (choline binding repeats with different C-terminal tails) and character analysis of CBDs reveal a higher isoelectric point (pI) is related to promotion of biofilm formation. Phenotype characterization of biofilms revel CBD-C and CBD-D function differently, CBD-C promoting the formation of membrane-like structures and CBD-D promoting the formation of regular reticular structures. Gene expression analysis reveals membrane transport pathways are influenced with the binding of CBDs, among which the phosphate uptake and PTS of galactose pathways are both up-regulated under conditions with CBDs. Further, extracellular substances detection revealed that extracellular proteins increased with CBD-A and CBD-D, exhibiting as increase in extracellular high molecular weight proteins. Extracellular DNA increased under CBD-A but decreased under CBD-C and CBD-D; Extracellular phosphate increased under CBD-C. These support the alterations in membrane transport pathways, and reveal diverse reactions to extracellular protein, DNA and phosphate of these three CBDs. Overall, our results indicated extracellular CBP participate in biofilm formation by affecting surface charge and membrane transport pathways of pneumococcal cells, as well as promoting reactions to extracellular substances.

Incidence and risk factors of postoperative delirium after pancreatic cancer surgery: a retrospective study.

PURPOSE: Postoperative delirium (POD) commonly occurs after major abdominal surgery and is associated with increased morbidity and mortality. There have been many studies on the relationship between POD and various surgeries, but research on POD after pancreatic cancer surgery is limited. The aim of this study was to identify the incidence and risk factors of POD after pancreatic cancer surgery. METHODS: The subjects of this retrospective analysis were 196 patients who were transferred for postoperative care after pancreatic cancer surgery, to a 12-bed critical care medicine ward at Shandong Provincial Hospital, affiliated with Shandong First Medical University, between January 2015 and December 2019. The patients were divided according to whether they suffered POD into a delirium group and a non-delirium group. Delirium was assessed using the Confusion Assessment Method for the Intensive Care Unit and two independent medical practitioners analyzed all the data. Univariate and multiple logistic regression analyses were performed. RESULTS: The overall delirium incidence was 20.41%, which increased to 29.03% for patients aged ≥ 70 years. POD was associated with age, smoking, the American Society of Anesthesiologists classification, the Acute Physiology and Chronic Health Evaluation II score, and the TNM stage of the cancer. The variables concerning sex, drinking, hypertension, a history of cerebral disease, surgery type, operation time, amount of bleeding, and the intraoperative use of dexmedetomidine did not differ significantly between the two groups. There was no significant difference in the length of ICU stay, with the exclusion of long-term stay for complications, between the groups, but POD tended to prolong the postoperative hospital stay and increase the risk of mortality. There was also a gradual decline in the incidence of POD between 2015 and 2019, especially from 2015 to 2018, after preventive measures were implemented. CONCLUSION: POD is related to many risk factors and worthy of attention. Appropriate management can reduce its incidence or at least shorten its duration.

Cortistatin-14 Exerts Neuroprotective Effect Against Microglial Activation, Blood-brain Barrier Disruption, and Cognitive Impairment in Sepsis-associated Encephalopathy.

Sepsis-associated encephalopathy (SAE) is a life-threatening deterioration of mental status in relation to long-term and disabling cognitive dysfunction that is common in intensive care units worldwide. Cortistatin-14 is a neuropeptide structurally resembling somastostatin, which has been proven to play a crucial role in sepsis. The present study aimed to explore the neuroprotective role of cortistatin-14 in sepsis-associated encephalopathy and its underlying mechanisms in a mouse model. A septic mice model was established using the cecal ligation and puncture (CLP) method. The novel object recognition test (NORT), open field test (OFT), elevated plus maze test (EPMT), and tail suspension test (TST) were used to explore the behavioral performance of the mice. Transmission electron microscopy was used to observe the microstructure of the blood-brain barrier (BBB). Evans Blue staining was used to examine the integrity of the BBB. Immunofluorescence was used to examine the morphology and infiltration of microglia. A multiplex cytokine bead array assay was used to determine cytokine and chemokine levels in mouse serum and brain tissues. NORT revealed that cortistatin treatment improved cognitive impairment in septic mice. OFT, EPMT, and TST indicated that cortistatin-14 relieved the anxiety-related behaviors of CLP mice. In addition, cortistatin-14 treatment decreased the levels of various inflammatory cytokines, including interleukin-1ß, interleukin-6, interferon-γ, and tumor necrosis factor-α in both the serum and brain of septic mice. Cortistatin reduced sepsis-induced blood-brain barrier disruption and inhibited microglial activation after the onset of sepsis. Cortistatin exerts neuroprotective effects against SAE and cognitive dysfunction in a CLP-induced mouse model of sepsis.

Characterization of a group of peptides for potential applications in hydrogen phosphate and heavy metals accumulation.

Phosphorus and heavy metals are discarded to the domestic sewage in our daily life, it is necessary to find easy methods for phosphorus and heavy metals accumulation. Here, a group of short peptides (ChBpHs) were found to react with hydrogen phosphate forming insoluble substances. ChBpHs are composed by a choline binding peptides (ChBp) and a C-terminal histidine rich tail. The reaction region to hydrogen phosphate was determined at 1-18th amino acid in ChBp. The affinities of ChBpHs are different, with minimum react concentrations of Na2HPO4 ranging from 2 to 12 mM. In addition, the C-terminal histidine tail enables ChBpHs with affinities to metal ions in vitro. Prokaryotic expression of ChBpH1 in Escherichia coli resulted in the reduction of soluble hydrogen phosphate in the culture medium. The accumulation of phosphate is time and concentration dependent, maximum reduction was detected at 24 h post induction (23% in phosphate rich medium and 14% in normal medium). The reduction of nickel ions (about 20%) was only detected after cells were broken. In conclusion, this preliminary investigation of ChBpHs indicates the potential applications for bioconcentration of soluble phosphate in the future.

Therapeutic effect of ulinastatin on pulmonary fibrosis via downregulation of TGF­ß1, TNF­α and NF­κB.

Pulmonary fibrosis is a chronic, progressive, lethal lung disease characterized by alveolar cell necrosis and dysplasia of interstitial fibrotic tissue, resulting in loss of lung function and eventual respiratory failure. Previously, glucocorticoid drugs were used to treat this lung disorder. However, positive responses were recorded in less than half of treated patients and the cytotoxicity caused by high dosage treatment is still a concern. The present study investigated whether ulinastatin, a typical urinary trypsin inhibitor that mitigates numerous inflammatory responses, could be a treatment option for lung fibrosis. The results demonstrated that ulinastatin had the ability to ameliorate interstitial fibrosis and alveolar exudates and to protect against lung diseases induced by smoke, irradiation or silica particles. The mechanism of ulinastatin resulted in the downregulation of inflammatory cascades: Transforming growth factor­ß1, tumor necrosis factor­α and nuclear factor­κB, as demonstrated by western blotting and ELISA. Ulinastatin treatment with a high dose (100,000 U/kg body weight/day) resulted in an attenuated inflammatory response, and inhibited fibrosis formation in lungs, suggesting that ulinastatin may become a part of a clinical therapeutic strategy.

MicroRNA-181d is a tumor suppressor in human esophageal squamous cell carcinoma inversely regulating Derlin-1.

Esophageal squamous cell carcinoma (ESCC) is the predominant subtype of human esophageal cancer in East Asia. In the present study, we explored the tumor suppressive function of microRNA-181d (miR-181d) in ESCC. Quantitative RT-PCR was used to assess gene levels of miR­181d in both ESCC cell lines and clinical samples. Lentiviral transduction was used to overexpress miR-181d in ECA109 and Kyse30 cells. The possible tumor suppressive effects of miR-181d overexpression on ESCC proliferation, migration and cell cycle transition in vitro, and tumorigenicity in vivo were examined. Downstream target gene of miR­181d in ESCC, Derlin-1 (DERL1) was assessed by luciferase assay and qRT-PCR. DERL1 was also force expressed in miR­181d-overexperssed ECA109 and Kyse30 cells to evaluate its reverse effect on miR-181d mediated tumor suppression in ESCC. miR-181d was aberrantly downregulated in both ESCC cell lines and human tumors. Lentivirus-mediated miR-181d overexpression had significant tumor suppressing functions by inhibiting cancer proliferation, migration and arresting cell cycle transition in vitro, as well as inhibiting tumorigenicity in vivo. DERL1 was identified as downstream target gene of miR-181d in ESCC cells. Forced overexpression of DERL1 in ESCC cells was shown to greatly reverse the tumor suppressive effects of miR-181d upregulation on ESCC in vitro proliferation, migration and cell cycle arrest. Out data suggest that miR-181d is a tumor suppressor in ESCC inversely regulating its downstream target gene of DERL1.