METTL3 confers protection against mitochondrial dysfunction and cognitive impairment in an Alzheimer disease mouse model by upregulating Mfn2 via N6-methyladenosine modification.

Mitofusin 2 (MFN2) has been found to be downregulated in patients with Alzheimer disease (AD) but little is known about its roles in the pathogenesis of AD. We explored the mechanism of N6-methyladenosine (m6A) methylation of Mfn2 in hippocampal mitochondrial dysfunction in an AD mouse model. APP/PS1 transgenic mice underwent stereotaxic injection of adeno-associated viruses and their behaviors were assessed. METTL3 and MFN2 expressions were measured by qRT-PCR and Western blot, accompanied by assessment of mitochondrial morphology, ATP, mitochondrial membrane potential, and amyloid-ß content. Binding between METTL3 and MFN2, the total amount of m6A, and the m6A modification of Mfn2 were also determined. METTL3 and MFN2 were downregulated in hippocampal tissues of the AD model mice; METTL3 enhanced MFN2 expression via m6A modification. Overexpression of METTL3 or MFN2 ameliorated mitochondrial dysfunction indicated by fewer damaged mitochondria, increased ATP and JC-1 levels, and reduced Aß content; improved cognitive impairment in the mice was indicated by the novel object discrimination index and Morris water maze tests. Effects of METTL3 overexpression were abrogated by further knockdown of MFN2. Thus, METTL3 ameliorated mitochondrial dysfunction and cognitive impairment in the AD model mice by increasing MFN2 expression via m6A modification.

Systematic analysis of MASP-1 serves as a novel immune-related biomarker in sepsis and trauma followed by preliminary experimental validation.

Background: Dysregulated immune response in trauma and sepsis leads to the abnormal activation of the complement and coagulation systems. Mannose-binding lectin (MBL)-associated serine protease-1 (MASP-1) activates the lectin pathway of the complement system and mediates proinflammatory and procoagulant reactions. However, the potential effects of MASP-1 in trauma and sepsis have not yet been explored. Methods: We obtained five sepsis, two trauma, and one sepsis and trauma RNA-sequencing dataset from the Gene Expression Omnibus (GEO) database and conducted a comprehensive evaluation of the expression pattern, biological functions, and diagnostic value of MASP-1 in trauma and sepsis. Additionally, we investigated the association between MASP-1 expression and clinicopathological characteristics of trauma and sepsis. Furthermore, we collected clinical specimens to preliminarily validate the expression level and diagnostic efficacy of MASP-1 as well as the correlation of MASP-1 with clinical features of trauma and sepsis. Subsequently, we conducted a correlation analysis among MASP-1, immune cell infiltration, and immune and molecular pathways. Finally, we mechanistically analyzed the relationship among MASP-1, specific immune cells, and pivotal molecular pathways. Results: MASP-1 expression was significantly upregulated in the trauma/sepsis samples compared to the control samples in the GEO datasets. MASP-1 exhibited excellent diagnostic values (AUC > 0.7) in multiple datasets and at multiple time points and could efficiently distinguish trauma/sepsis samples from the control samples. Moreover, MASP-1 expression was significantly positively correlated with the severity of the disease (APACHE-II, CRP, and neutrophil levels). These results were further validated by real-time quantitative polymerase chain reaction and enzyme-linked immunosorbent assay. Functional enrichment analysis revealed that MASP-1 primarily promotes trauma and sepsis via the immune-related signaling pathway. MASP-1 was significantly correlated with the infiltration of specific immune cells (such as B cells, CD8 T cells, neutrophils, macrophages, and infiltrating lymphocytes) and immune and molecular pathways (such as checkpoint, HLA, IL6/JAK/STAT3 signaling, necrosis, T-cell co-inhibition, and T-cell co-stimulation). Finally, analysis of the transcription and single-cell data revealed that MASP-1 was specifically expressed in T cells, and further correlation analysis revealed a close correlation between MASP-1 expression, proportion of CD8 T cells, and IL6/JAK/STAT3 signaling scores. Conclusion: Our results suggest that MASP-1 can serve as an immune-related biomarker for the diagnosis and disease severity of trauma and sepsis. It may activate the IL6 JAK-STAT3 signaling pathway and promote CD8 T-cell depletion to trigger traumatic sepsis.

Risk factors for delirium after surgery for craniocerebral injury in the neurosurgical intensive care unit.

BACKGROUND: Postoperative delirium is common in patients who undergo neurosurgery for craniocerebral injury. However, there is no specific medical test to predict postoperative delirium to date. AIM: To explore risk factors for postoperative delirium in patients with craniocerebral injury in the neurosurgery intensive care unit (ICU). METHODS: A retrospective analysis was performed in 120 patients with craniocerebral injury admitted to Hainan People's Hospital/Hainan Hospital Affiliated to Hainan Medical University, The First Affiliated Hospital of Hainan Medical University, and The Second Affiliated Hospital of Hainan Medical University between January 2018 and January 2020. The patients were categorized into groups based on whether delirium occurred. Of them, 25 patients with delirium were included in the delirium group, and 95 patients without delirium were included in the observation group. Logistic regression analysis was used to explore the association between sex, age, educational level, Glasgow coma scale (GCS), complications (with or without concussion, cerebral contusion, hypoxemia and ventricular compression) and site of injury and delirium. RESULTS: The GCS score above 8 and concomitant disease of cerebral concussion, cerebral contusion, hypoxemia and ventricular compression, and damage to the frontal lobe were associated with delirium in patients admitted to neurosurgical intensive care unit (ICU) (all P < 0.05). However, age, sex, administration more than three medicines, and educational level were not significantly associated with the onset of delirium in patients with craniocerebral injury in the neurosurgical ICU (P < 0.05). Multivariate logistic regression analysis showed that GCS score above 8, cerebral concussion, cerebral contusion, hypoxemia, ventricle compression, and frontal lobe disorders were independent risk factors for delirium in patients with craniocerebral injury in the neurosurgical ICU (P < 0.05). CONCLUSION: GCS score, concussive concussion, cerebral contusion, hypoxemia, ventricle compression, and damage to frontal lobe are risk factors of postoperative delirium.