PKM2 Nuclear Translocation Promotes Glial Cell Activation and Aggravates the Brain Injury of Intracerebral Hemorrhage.

BACKGROUND: The purpose of this study was to investigate the potential involvement of pyruvate kinase M2 (PKM2), an enzyme acting as a rate-limiting enzyme in the final phase of glycolysis, in the regulation of glial activation and brain damage of intracerebral hemorrhage (ICH). METHODS: Western blotting and immunofluorescence were performed to investigate PKM2 expression, terminal deoxynucleotidyl transferase deoxyurinary triphosphate (dUTP) nick end labeling staining, hematoxylin and eosin staining, and behavioral tests were employed to evaluate the brain damage of ICH mice, and RNA-seq and bioinformatic analyses were performed to detect gene expression changes in ICH mice treated with TEPP-46. RESULTS: Increased PKM2 levels in perihematomal brain tissue were found starting from 3 days following ICH and peaked at 5 and 7 days post ICH. The increased expression of PKM2 was mainly co-localized with glial fibrillary acidic protein (GFAP)+ astrocytes and ionized calcium binding adaptor molecule-1 (IBA-1)+ microglia. Furthermore, we observed a notable increase in the nuclear translocation of PKM2 in glial cells following ICH. TEPP-46 treatment significantly reduced PKM2 nuclear translocation, and effectively attenuated glial activation and brain injury, and improved functional recovery of mice with ICH. RNA-seq data indicated that 91.1% (205/225) of differentially expressed genes (DEGs) were down-regulated in the TEPP-46 treated groups compared with the vehicle-treated groups in ICH brains. Furthermore, bioinformatic analyses revealed that these down-regulated DEGs were involved in a variety of biological processes, including autophagy and metabolic processes. In addition, the majority of these downregulated DEGs had a primary high expression in neurons, with subsequent expression seen in endothelial cells, microglia, and astrocytes. CONCLUSIONS: These results indicate that increased PKM2 nuclear translocation promotes the activation of glial cells after ICH, hence aggravating ICH-induced brain damage, and aggravates the brain injury induced by ICH. This highlights a potential therapeutic target for inhibiting glial activation to attenuate brain injury after ICH.

Deep Succinylproteomics of Brain Tissues from Intracerebral Hemorrhage with Inhibition of Toll-Like Receptor 4 Signaling.

It is unclear how Toll-like receptor (TLR) 4 signaling affects protein succinylation in the brain after intracerebral hemorrhage (ICH). Here, we constructed a mouse ICH model to investigate the changes in ICH-associated brain protein succinylation, following a treatment with a TLR4 antagonist, TAK242, using a high-resolution mass spectrometry-based, quantitative succinyllysine proteomics approach. We characterized the prevalence of approximately 6700 succinylation events and quantified approximately 3500 sites, highlighting 139 succinyllysine site changes in 40 pathways. Further analysis showed that TAK242 treatment induced an increase of 29 succinyllysine sites on 28 succinylated proteins and a reduction of 24 succinyllysine sites on 23 succinylated proteins in the ICH brains. TAK242 treatment induced both protein hypersuccinylations and hyposuccinylations, which were mainly located in the mitochondria and cytoplasm. GO analysis showed that TAK242 treatment-induced changes in the ICH-associated succinylated proteins were mostly located in synapses, membranes and vesicles, and enriched in many cellular functions/compartments, such as metabolism, synapse, and myelin. KEGG analysis showed that TAK242-induced hyposuccinylation was mainly linked to fatty acid metabolism, including elongation and degradation. Moreover, a combined analysis of the succinylproteomic data with previously published transcriptome data revealed that most of the differentially succinylated proteins induced by TAK242 treatment were mainly distributed throughout neurons, astrocytes, and endothelial cells, and the mRNAs of seven and three succinylated proteins were highly expressed in neurons and astrocytes, respectively. In conclusion, we revealed that several TLR4 signaling pathways affect the succinylation processes and pathways in mouse ICH brains, providing new insights on the ICH pathophysiological processes. Data are available via ProteomeXchange with identifier PXD025622.

Succinylation profiles of brain injury after intracerebral hemorrhage.

Protein posttranslational modifications (PTMs) regulate the biological processes of human diseases by genetic code expansion and cellular pathophysiology regulation; however, system-wide changes in PTM levels in the intracerebral hemorrhage (ICH) brain remain poorly understood. Succinylation refers to a major PTM during the regulation of multiple biological processes. In this study, according to the methods of quantitative succinyllysine proteomics based on high-resolution mass spectrometry, we investigated ICH-associated brain protein succinyllysine modifications and obtained 3,680 succinylated sites and quantified around 3,530 sites. Among them, 25 succinyllysine sites on 23 proteins were upregulated (hypersuccinylated), whereas 13 succinyllysine sites on 12 proteins were downregulated (hyposuccinylated) following ICH. The cell component enrichment analysis of these succinylproteins with significant changes showed that 58.3% of the hyposuccinylated proteins were observed in the mitochondria, while the hyper-succinylproteins located in mitochondria decreased in the percentage to about 35% in ICH brains with a concomitant increase in the percentage of cytoplasm to 30.4%. Further bioinformatic analysis showed that the succinylproteins were mostly mitochondria and synapse-related subcellular located and involved in many pathophysiological processes, like metabolism, synapse working, and ferroptosis. Moreover, the integrative analysis of our succinylproteomics data and previously published transcriptome data showed that the mRNAs matched by most differentially succinylated proteins were especially highly expressed in neurons, endothelial cells, and astrocytes. Our study uncovers some succinylation-affected processes and pathways in response to ICH brains and gives us novel insights into understanding pathophysiological processes of brain injury caused by ICH.

[Epidemiological survey of asthma in a rural area of Yanqing County in Beijing].

OBJECTIVE: To evaluate the epidemiology and risk factors of asthma of people aged more than 40 years living in the rural area of Beijing. METHODS: The data of 1,638 people aged more than 40 years living in 5 villages of Yanqing County in Beijing were collected. Respiratory symptoms, the living conditions, life styles and cooking habits, personal history and family history were collected. Physical examination and lung function tests (ventilation function and bronchodilation tests) were also performed. Asthma was diagnosed based on symptoms, signs, and lung function tests. Univariate analysis and Logistic analysis were employed to evaluate the risk factors for asthma. RESULTS: The prevalence of asthma was 1.89% (31/1 638). For those with asthma, the male to female ratio was 1:4.2, the difference being significant (P<0.05). Common triggering factors for asthma included influenza, cold air, passive smoking and cooking oil smoke. There were statistic differences between asthmatics and non-asthmatics in respiratory disease history in childhood, frequent cough before age 14, and years of exposure to biomass fuel. Cough before age 14 was closely associated with asthma. Only 12.9% of the cases had been diagnosed before this study, indicating that asthma was a underdiagnosed disease in this area. CONCLUSION: The prevalence of asthma is high in this rural area of Beijing. Life style changes and management of respiratory infections before age 14 are indicated for reducing risk factors for asthma. More attention should be paid to early diagnosis of asthma in rural areas.

[Epidemiological data of chronic obstructive pulmonary disease in Yanqing County in Beijing].

OBJECTIVE: To evaluate the epidemiological characteristic and risk factors of chronic obstructive pulmonary disease (COPD) in the rural area of Beijing. METHODS: The data of 1,624 people aged more than 40 in 5 villages in Yanqing County in Beijing were collected. The habitation condition, life and cooking habit, smoking history, personal history and family history were asked, and their physical examinations and lung function tests were conducted. RESULTS: The prevalence of COPD was 9.11% in this area, 15.05% in males and 3.76% in females. There were significant differences in sex, age, smoking history, family history, frequent cough before age 14 and body index between the COPD and non-COPD groups. The prevalence of corpulmonale was 1.66% in this area. CONCLUSION: The prevalence of COPD was high in this area and related with sex, age, smoking history, family history, frequent cough before age 14 and low body index. Other factors such as environment, working exposure need to be studied in the future. COPD is a major public health problem, which should claim more attention.

[Characteristics of non-symptomatic chronic obstructive pulmonary disease patients].

OBJECTIVE: To evaluate the epidemiological characteristics of non-symptomatic chronic obstructive pulmonary disease (COPD) patients in a rural area in Beijing. METHODS: The data of 1,624 people aged more than 40 in 5 villages in Yanqing county in Beijing were collected. Information of medical history and symptom were obtained, and physical examination and lung function test were performed. RESULTS: The prevalence of COPD was 9.1% (148/1 624) in this area. In these 148 patients, 62 (42%) were non-symptomatic and 86 (58%) were symptomatic, the prevalence of non-symptomatic COPD being 3.8% (62/1 624). There was no statistical difference in the sex, age, occupation, marriage status, education level and smoking index between the symptomatic and the non-symptomatic groups (all P > 0.05). The forced expired volume in one second (FEV(1)) and FEV(1)% predicted were lower in the symptomatic group [(1.3 +/- 0.7) L, (61 +/- 23)%] than those in the non-symptomatic group [(1.5 +/- 0.6) L, (70 +/- 22)%; all P < 0.05]. CONCLUSIONS: The prevalence of COPD was high in this area with a high percentage of non-symptomatic patients. The COPD prevalence might be underestimated due to the symptom free patients.