Fibrinogen deposition promotes neuroinflammation and fibrin-derived γ377-395 peptide ameliorates neurological deficits after ischemic stroke.

BACKGROUND: Fibrin(ogen) deposition in the central nervous system (CNS) contributes to neuropathological injury; however, its role in ischemic stroke is unknown. In this study, we identified fibrinogen as a novel proinflammatory regulator of post-stroke neuroinflammation and revealed the neuro-protection effect of fibrin-derived γ377-395peptide in stroke. METHODS: Fibrinogen depletion and fibrinogen-derived γ377-395peptide treatment were performed 2 h after establishing a permanent middle cerebral artery occlusion (pMCAO) model. The infarction volume, neurological score, fibrin(ogen) deposition, and inflammatory response were evaluated 24 h after occlusion. Both in vivo and in vitro studies were conducted to assess the therapeutic potential of the γ377-395peptide in blocking the interactions between fibrin(ogen) and neutrophils. RESULTS: Fibrin(ogen) deposited in the infarct core promoted post-stroke inflammation and exacerbated neurological deficits in the acute phase after stroke onset. Reducing fibrinogen deposition resulted in a decrease in infarction volume, improved neurological scores, and reduced inflammation in the brain. Additionally, the presence of neutrophil accumulation near fibrin(ogen) deposits was observed in ischemic lesions, and the engagement of fibrin(ogen) by integrin receptor αMß2 promoted neutrophil activation and post-stroke inflammation. Finally, inhibiting fibrin(ogen)-mediated neutrophil activation using a fibrinogen-derived γ377-395peptide significantly attenuated neurological deficits. CONCLUSIONS: Fibrin(ogen) is a crucial regulator of post-stroke inflammation and contributes to secondary brain injury. The inflammation induced by fibrin(ogen) is primarily driven by neutrophils during acute ischemic stroke and can be ameliorated using the fibrin-derived γ377-395peptide. Targeting the fibrin(ogen)-mediated neuropathological process represents a promising approach for neuroprotective therapy after stroke while preserving its beneficial coagulation function.

N6-Methyladenosine (m6A) Methylation Is Associated with the Immune Microenvironments in Acute Intracerebral Hemorrhage (ICH).

Researchers have recently found that N6-methyladenosine (m6A) is a type of internal posttranscriptional modification that is essential in mammalian mRNA. However, the features of m6A RNA methylation in acute intracerebral hemorrhage (ICH) remain unknown. To explore differential methylations and to discover their functions in acute ICH patients, we recruited three acute ICH patients, three healthy controls, and an additional three patients and healthy controls for validation. The m6A methylation levels in blood samples from the two groups were determined by ultrahigh-performance liquid chromatography coupled with triple quadruple mass spectrometry (UPLC-QQQ-MS). Methylated RNA immunoprecipitation sequencing (MeRIP-seq) was employed to identify differences in m6A modification, and the differentially expressed m6A-modified genes were confirmed by MeRIP-qPCR. We found no significant differences in the total m6A levels between the two groups but observed differential methylation peaks. Compared with the control group, the coding genes showing increased methylation following acute ICH were mostly involved in processes connected with osteoclast differentiation, the neurotrophin signaling pathway, and the spliceosome, whereas genes with reduced m6A modification levels after acute ICH were found to be involved in the B-cell and T-cell receptor signaling pathways. These results reveal that differentially m6A-modified genes may influence the immune microenvironments in acute ICH.

Seizure syndrome as a first manifestation of solitary tumor-like mass lesion of PACNS: Two case reports.

RATIONALE: Primary angiitis of the central nervous system (PACNS) is an inflammatory disease involving cerebrovascular and parenchymal, and solitary tumor-like mass lesion of PACNS (TLML-PACNS) is frequently misdiagnosed as neoplastic or other inflammatory diseases. However, seizure syndrome as a first manifestation of TLML-PACNS has rarely reported before. PATIENT CONCERNS: Here, we report 2 cases of seizure syndrome, which was the first sign that presented prior to the diagnosis of TLML-PACNS by brain biopsy. DIAGNOSES: A mass lesion in the white and gray matters was detected by magnetic resonance imaging. The pathology for leptomeningeal lesion biopsy observed a transmural inflammation of the artery, with T lymphocyte infiltration. Patients were diagnosed with PACNS and epileptic seizure by biopsy and electroencephalogram. INTERVENTIONS: Patients were treated with glucocorticoid pulse therapy for 3 days, and subsequently oral prednisone was continued, in combination with immunosuppressant. OUTCOMES: Luckily, both two patients were improved after treatment, and only mild cognitive impairment remained without adverse event. LESSONS: Patient with mass lesion in CNS, which is similar to tumor, presented with seizure, headache, or cerebrovascular events without any other risk factors for stroke or tumor, should be considered the feasible with the disease of TLML-PACNS.

Neurological antiphospholipid syndrome: Clinical, neuroimaging, and pathological characteristics.

BACKGROUND: Neurological antiphospholipid syndrome (NAPS) is often misdiagnosed or missed. Only limited clinical and neuroimaging information about it is available, and the pathological characteristics was rarely reported before. This study aimed to explore the clinical, neuroimaging, and pathological characteristics of NAPS. METHODS: We performed a retrospective analysis of 51 patients with APS, categorized into NAPS (n = 16) and rheumatology antiphospholipid syndrome (RAPS) groups (n = 35). Demographics and clinical profile were compared between the two groups, and the neuroimaging and pathological information of NAPS was also analyzed. RESULTS: The mean age of the NAPS patients, 81.25% of whom were female, was 37.56 ± 12.36 years, and the average duration was 1.32 ± 0.96 years (range = 18 days to 3.5 years). No significant differences in age, sex, disease duration, classification, and comorbidities at baseline were observed between NAPS and RAPS patients (p > 0.05). Chief complaint of headache and thromboembolic events was higher in NAPS patients than in RAPS patients (p<0.05). Neuroimaging detected multiple infarcts and demyelination lesions were distributed in subcortical and cortical area asymmetrically. Skin biopsy examination showed small vessel occlusion with inflammatory cells, while brain biopsy examination showed erythrocyte accumulation with some neuron degeneration and local demyelization. Antithrombotic and immunosuppressive therapy proved to be effective. CONCLUSION: Headache and thromboembolic events are more common in NAPS than RAPS. Neuroimaging and biopsy examination demonstrated that NAPS is an ischemic cerebrovascular disease caused by vascular stenosis or occlusion. These characteristics might help to reduce the misdiagnosis of NAPS.

Grb2-associated binder 1 is essential for cardioprotection against ischemia/reperfusion injury.

We have shown recently that endothelial Grb-2-associated binder 1 (Gab1), an intracellular scaffolding adaptor, has a protective effect against limb ischemia via mediating angiogenic signaling pathways. However, the role of Gab1 in cardiac ischemia/reperfusion (I/R) injury remains unknown. In this study, we show that Gab1 is required for cardioprotection against I/R injury. I/R injury led to remarkable phosphorylation of Gab1 in cardiomyocytes. Compared with controls, the mice with cardiomyocyte-specific deletion of Gab1 gene (CGKO mice) exhibited an increase in infarct size and a decrease in cardiac function after I/R injury. Consistently, in hearts of CGKO mice subjected to I/R, the activation of caspase 3 and myocardial apoptosis was markedly enhanced whereas the activation of protein kinase B (Akt) and mitogen-activated protein kinase (MAPK), which are critical for cardiomyocyte survival, was attenuated. Oxidative stress is regarded as a major contributor to myocardial I/R injury. To examine the role of Gab1 in oxidative stress directly, isolated adult cardiomyocytes were subject to oxidant hydrogen peroxide and the cardioprotective effects of Gab1 were confirmed. Furthermore, we found that the phosphorylation of Gab1 and Gab1-mediated activation of Akt and MAPK by oxidative stress was suppressed by ErbB receptor and Src kinase inhibitors, accompanied by an increase in apoptotic cell death. In conclusion, our results suggest that Gab1 is essential for cardioprotection against I/R oxidative injury via mediating survival signaling.

Follicle-stimulating hormone regulates pro-apoptotic protein Bcl-2-interacting mediator of cell death-extra long (BimEL)-induced porcine granulosa cell apoptosis.

The pro-apoptotic protein Bim (B-cell lymphoma-2 (Bcl-2)-interacting modulator of cell death) has recently been identified and shown to promote cell death in response to several stimuli. In this report, we investigated the role of Bim in porcine follicular atresia. Initially, Bim cDNA was cloned and characterized from porcine ovarian tissue. Porcine Bim had three alternative splicing variants (Bim-extra long, Bim-long, and Bim-short), all containing the consensus Bcl-2 homology 3 domain. We then found the Bim-extra long (Bim(EL)) protein, the most abundant isoform of Bim, was strongly expressed and co-localized with apoptotic (TUNEL-positive) granulosa cells from porcine atretic follicles. Furthermore, overexpression of Bim(EL) triggered apoptosis in granulosa cells. In primary granulosa cell cultures under basal conditions, we observed that Bim(EL) expression was dampened by treatment with follicle-stimulating hormone (FSH). The role of the PI3K/Akt pathway in the regulation of repression was clarified by the use of the PI3K inhibitor, LY294002, and by transfection with Akt siRNA. Forkhead Box Protein O3a (FoxO3a), a well defined transcriptional activator of Bim, was phosphorylated at Ser-253 and inactivated after FSH stimulation. Also, FSH abolished FoxO3a nuclear accumulation in response to LY294002. Finally, chromatin immunoprecipitation assays demonstrated that FoxO3a directly bound and activated the bim promoter. Taken together, we conclude that Bim(EL) induces porcine granulosa cell apoptosis during follicular atresia, and its expression is regulated by FSH via the PI3K/Akt/FoxO3a pathway.

Grb-2-associated binder 1 (Gab1) regulates postnatal ischemic and VEGF-induced angiogenesis through the protein kinase A-endothelial NOS pathway.

The intracellular signaling mechanisms underlying postnatal angiogenesis are incompletely understood. Herein we show that Grb-2-associated binder 1 (Gab1) plays a critical role in ischemic and VEGF-induced angiogenesis. Endothelium-specific Gab1 KO (EGKO) mice displayed impaired angiogenesis in the ischemic hindlimb despite normal induction of VEGF expression. Matrigel plugs with VEGF implanted in EGKO mice induced fewer capillaries than those in control mice. The vessels and endothelial cells (ECs) derived from EGKO mice were defective in vascular sprouting and tube formation induced by VEGF. Biochemical analyses revealed a substantial reduction of endothelial NOS (eNOS) activation in Gab1-deficient vessels and ECs following VEGF stimulation. Interestingly, the phosphorylation of Akt, an enzyme known to promote VEGF-induced eNOS activation, was increased in Gab1-deficient vessels and ECs whereas protein kinase A (PKA) activity was significantly decreased. Introduction of an active form of PKA rescued VEGF-induced eNOS activation and tube formation in EGKO ECs. Reexpression of WT or mutant Gab1 molecules in EGKO ECs revealed requirement of Gab1/Shp2 association for the activation of PKA and eNOS. Taken together, these results identify Gab1 as a critical upstream signaling component in VEGF-induced eNOS activation and tube formation, which is dependent on PKA. Of note, this pathway is conserved in primary human ECs for VEGF-induced eNOS activation and tube formation, suggesting considerable potential in treatment of human ischemic diseases.

[Frusemide plus doxazosin therapy for nocturia in patients with BPH/LUTS].

OBJECTIVE: To determine the efficacy and safety of a diuretic agent, frusemide, combined with doxazosin in the treatment of nocturia in patients with benign prostate hyperplasia / lower urinary tract symptoms (BPH/LUTS). METHODS: Sixty-four BPH/LUTS patients with nocturia were equally randomized into two groups, one treated with doxazosin (4 mg/d), and the other with frusemide (40 mg/d) and doxazosin (4 mg/d), given 6 h before sleep, both for 4 weeks. Urine volume, IPSS, QOL, serum electrolytes, plasma osmolality were recorded and compared between the two groups before and after the treatment. RESULTS: Compared with the doxazosin group, the frusemide plus doxazosin group showed significantly reduced nocturia frequency (P < 0.01), increased daytime urine output (P < 0.01), decreased nocturia urine output (P < 0.01), unchanged total urine output (P > 0.05), improved IPSS and QOL (P < 0.05, P < 0.01), but with no remarkable differences in the levels of serum sodium, potassium, chlorine, and osmotic pressure (P > 0.05). CONCLUSION: Four-week treatment with frusemide plus doxazosin was safe and effective for nocturia in patients with BPH/LUTS.