Genome-Wide Mendelian Randomization Study Reveals Druggable Genes for Cerebral Small Vessel Disease.

BACKGROUND: Cerebral small vessel disease (CSVD) is a group of neurological disorders that affect the small blood vessels within the brain, for which no effective treatments are currently available. We conducted a Mendelian randomization (MR) study to identify candidate therapeutic genes for CSVD. METHODS: We retrieved genome-wide association study data from 6 recently conducted, extensive investigations focusing on CSVD magnetic resonance imaging markers and performed a 2-sample MR analysis to assess the potential causal effects of gene expression and protein level within druggable genes on CSVD in blood and brain tissues. Colocalization analyses and repeat studies were undertaken to verify the relationship. Additionally, mediation analysis was conducted to explore the potential mechanisms involving druggable genes and known risk factors for CSVD. Finally, phenome-wide MR analyses were applied to evaluate the potential adverse effects related to the identified druggable genes for CSVD treatment. RESULTS: Overall, 5 druggable genes consistently showed associations with CSVD in MR analyses across both the discovery and validation cohorts. Notably, the ALDH2 and KLHL24 genes were identified as associated with CSVD in both blood and brain tissues, whereas the genes ADRB1, BTN3A2, and EFEMP1 were exclusively detected in brain tissue. Moreover, mediation analysis elucidated the proportion of the total effects mediated by CSVD risk factors through candidate druggable genes, which ranged from 5.5% to 18.5%, and offered potential explanations for the observed results. A comprehensive phenome-wide MR analysis further emphasized both the therapeutic benefits and potential side effects of targeting these candidate druggable genes. CONCLUSIONS: This study provides genetic evidence supporting the potential therapeutic benefits of targeting druggable genes for treating CSVD, which will be useful for prioritizing CSVD drug development.

Aquaporin-4 Antibody Dynamics and Relapse Risk in Seropositive Neuromyelitis Optica Spectrum Disorder Treated with Immunosuppressants.

OBJECTIVE: To investigate aquaporin-4 antibody (AQP4-IgG) dynamics and relapse risk in patients with seropositive neuromyelitis optica spectrum disorder treated with immunosuppressants. METHODS: This observational cohort study with prospectively collected data included 400 neuromyelitis optica spectrum disorder patients seropositive for AQP4-IgG and treated with immunosuppressants. Serum AQP4-IgG was detected by fixed cell-based assay every 6 months. RESULTS: After treatment with immunosuppressants, 128 patients became AQP4-IgG seronegative. The median time to become seronegative for 400 patients was 76.4 months (61.4 months, NA). Among those patients with negative change of AQP4-IgG, the mean annualized relapse rate significantly decreased after patients became seronegative (0.20 vs 0.77, p < 0.001), and a positive correlation was observed between time to become seronegative and relapse (OR 1.018, 95% CI 1.001-1.035, p < 0.05). Independent risk factors for AQP4-IgG becoming seronegative were older age at onset, initiation of immunosuppressants at onset, and shorter disease duration before maintenance therapy. Independent risk factors for relapse included younger age (≤46.4 years) at onset, poly-system involvement in the first attack, and unchanged or increased AQP4-IgG titer. The relapse risk was not associated with sex, combination with connective tissue disease, seropositivity for systemic autoimmune antibodies, or incomplete recovery from the first attack. INTERPRETATION: Patients with younger age at onset, poly-system involvement in the first attack, and unchanged or increased titer of AQP4-IgG are most likely to experience relapse under treatment with immunosuppressants. Time to AQP4-IgG becoming seronegative and change of AQP4-IgG titer may become the surrogate efficacy biomarkers in clinical trials. ANN NEUROL 2023;93:1069-1081.

Risk factor differences in five-year progression of Intracranial artery stenosis and cerebral small vessel disease in general population.

BACKGROUND: Intracranial artery stenosis (ICAS) and cerebral small vessel disease (CSVD) are associated with a heavy socioeconomic burden; however, their longitudinal changes remain controversial. METHODS: We conducted a longitudinal analysis on 756 participants of Shunyi Cohort who underwent both baseline and follow-up brain magnetic resonance imaging (MRI) and MR angiography in order to investigate the risk factors for ICAS and CSVD progression in community population. Incident ICAS was defined as new stenosis occurring in at least one artery or increased severity of the original artery stenosis. CSVD markers included lacunes, cerebral microbleeds (CMB), and white matter hyperintensities (WMH). RESULTS: After 5.58 ± 0.49 years of follow-up, 8.5% of the 756 participants (53.7 ± 8.0 years old, 65.1% women) had incident ICAS. Body mass index (BMI) (OR = 1.09, 95% CI = 1.01-1.17, p = 0.035) and diabetes mellitus (OR = 2.67, 95% CI = 1.44-4.93, p = 0.002) were independent risk factors for incident ICAS. Hypertension was an independent risk factor for incident lacunes (OR = 2.12, 95% CI = 1.20-3.77, p = 0.010) and CMB (OR = 2.32, 95% CI = 1.22-4.41, p = 0.011), while WMH progression was primarily affected by BMI (ß = 0.108, SE = 0.006, p = 0.002). A higher LDL cholesterol level was found to independently protect against WMH progression (ß = -0.076, SE = 0.027, p = 0.019). CONCLUSIONS: Modifiable risk factor profiles exhibit different in patients with ICAS and CSVD progression. Controlling BMI and diabetes mellitus may help to prevent incident ICAS, and antihypertensive therapy may conduce to mitigate lacunes and CMB progression. LDL cholesterol may play an inverse role in large arteries and small vessels.

Phenotypes Associated with NOTCH3 Cysteine-Sparing Mutations in Patients with Clinical Suspicion of CADASIL: A Systematic Review.

CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy) is caused by NOTCH3 mutations affecting the number of cysteines. The pathogenic role of cysteine-sparing NOTCH3 mutations with typical clinical CADASIL syndrome is still debated. This review aimed to characterize NOTCH3 cysteine-sparing mutations in patients with clinical suspicion of CADASIL. Articles on NOTCH3 cysteine-sparing mutations with clinical suspicion of CADASIL were reviewed. Clinical and radiological cerebral phenotypes data were extracted and characterized across regions and compared with phenotypes of typical CADASIL patients. We screened 298 NOTCH3 cysteine-sparing mutation individuals from 20 publications, and mutations in exon 3 were the most frequently reported (21.46%). Gait impairment (76.47%), cognitive impairment (67.47%), and stroke (62.37%) were the three most common clinical phenotypes; the most frequent radiological cerebral phenotypes were lacunes (74.29%) and cerebral microbleeds (72.73%). Compared with CADASIL patients, cognitive impairment and cerebral microbleed frequencies were significantly higher in patients with NOTCH3 cysteine-sparing mutations, while the white matter hyperintensities in anterior temporal polar and external capsule were rarely observed. Compared with Western patients, radiological phenotypes were more common than clinical phenotypes in cysteine-sparing Asian patients. More than half of cysteine-sparing patients had positive granular osmiophilic material deposits. NOTCH3 cysteine-sparing mutations in patients with clinical suspicion of CADASIL mainly manifested with gait and cognitive impairment but rare white matter hyperintensities in anterior temporal pole and external capsule. Further studies are warranted to pay attention to atypical NOTCH3 variants, which could guide specific diagnosis and help unravel underlying mechanisms.

Correlation between Circle of Willis configuration and intracranial arterial dolichoectasia, and genetic contributions.

OBJECTIVES: Intracranial arterial dolichoectasia (IADE) is characterized by the dilation, elongation, and tortuosity of intracranial arteries. We aimed to investigate the association between variations of the Circle of Willis (COW) and IADE in the general population, as well as estimate the genetic correlation between COW variations and IADE. METHODS: A total of 981 individuals from a population-based cohort were included. Brain magnetic resonance angiography was performed to assess COW variants and measure the diameters of intracranial arteries. IADE was defined as a total intracranial volume-adjusted diameter ≥ 2 standard deviations. Logistic regression models were used to analyze the association between COW variations and IADE. The heritability and genetic correlation were estimated using genome-wide complex trait analysis (GCTA) based on single nucleotide polymorphism (SNP) array data. RESULTS: The prevalence of IADE was 6.2 %. Hypoplastic/absent A1 segments were associated with an increase in contralateral ICA diameter (ß ± SE, 0.279 ± 0.049; p = 0.001) and a decrease in ipsilateral ICA diameter (ß ± SE, -0.300 ± 0.050; p = 0.001). Fetal-type posterior cerebral artery (FTP) was associated with a larger ICA diameter (ß ± SE, 0.326 ± 0.048; p = 0.001) and a smaller BA diameter (ß ± SE, -0.662 ± 0.043; p = 0.001). FTP revealed a positive genetic correlation with ICA dilation (rG = 0.259 ± 0.175; p = 0.0009) and a negative genetic correlation with BA dilation (rG = -0.192 ± 0.153, p = 0.015). CONCLUSIONS: There was an association between COW variations and larger intracranial arterial diameters in the general population. Genetic factors may play a role in the development of intracranial arterial dilation and the formation of COW variants.

P38-DAPK1 axis regulated LC3-associated phagocytosis (LAP) of microglia in an in vitro subarachnoid hemorrhage model.

BACKGROUND: The phagocytosis and homeostasis of microglia play an important role in promoting blood clearance and improving prognosis after subarachnoid hemorrhage (SAH). LC3-assocaited phagocytosis (LAP) contributes to the microglial phagocytosis and homeostasis via autophagy-related components. With RNA-seq sequencing, we found potential signal pathways and genes which were important for the LAP of microglia. METHODS: We used an in vitro model of oxyhemoglobin exposure as SAH model in the study. RNA-seq sequencing was performed to seek critical signal pathways and genes in regulating LAP. Bioparticles were used to access the phagocytic ability of microglia. Western blot (WB), immunoprecipitation, quantitative polymerase chain reaction (qPCR) and immunofluorescence were performed to detect the expression change of LAP-related components and investigate the potential mechanisms. RESULTS: In vitro SAH model, there were increased inflammation and decreased phagocytosis in microglia. At the same time, we found that the LAP of microglia was inhibited in all stages. RNA-seq sequencing revealed the importance of P38 MAPK signal pathway and DAPK1 in regulating microglial LAP. P38 was found to regulate the expression of DAPK1, and P38-DAPK1 axis was identified to regulate the LAP and homeostasis of microglia after SAH. Finally, we found that P38-DAPK1 axis regulated expression of BECN1, which indicated the potential mechanism of P38-DAPK1 axis regulating microglial LAP. CONCLUSION: P38-DAPK1 axis regulated the LAP of microglia via BECN1, affecting the phagocytosis and homeostasis of microglia in vitro SAH model. Video Abstract.

Different Types of Circulatory Inflammatory Biomarkers Associated with Cerebral Arterial Atherosclerosis and Dolichoectasia.

BACKGROUND: Although inflammation is found to be related to arteriopathy pathogenesis, it is yet to be determined the distinct correlations of specific inflammatory biomarker types contributing to different cerebral large vessel diseases. We aimed to investigate the association between multiple inflammatory biomarkers and cerebral atherosclerosis and dolichoectasia in a community-based sample. METHODS: A total of 960 participants of the Shunyi study were included. A panel of 14 circulatory inflammatory biomarkers was assessed and then grouped in three sets as systemic, endothelial-related, and media-related inflammation, based on underlying different inflammatory cascades. Intracranial atherosclerotic stenosis (ICAS), dolichoectasia estimated by magnetic resonance angiography, and carotid plaques estimated by ultrasound were also performed. RESULTS: Endothelial-related inflammatory group was related to the presence of ICAS (R2 = 0.215, p = 0.024) and carotid plaques (R2 = 0.342, p = 0.013). Backward stepwise elimination showed that E-selectin was prominent (ß = 0.67, 95% CI: 0.54-0.85, p = 0.001; ß = 0.79, 95% CI: 0.68-0.93, p = 0.005). Systemic inflammatory group was associated with an increased basilar artery diameter (R2 = 0.051, p < 0.001), and backward stepwise elimination showed that IL-6 was prominent (ß = 0.07, 95% CI: 0.03-0.11, p < 0.001). CONCLUSION: Different types of inflammatory biomarkers were associated with atherosclerosis and dolichoectasia, respectively, implying dissimilar inflammatory processes. Further confirming of their distinct anti-inflammatory roles as potential therapeutic targets is warrant.

Prognostic value of left atrial mechanics in cardiac light-chain amyloidosis with preserved ejection fraction: a cohort study.

BACKGROUND: Light-chain amyloidosis is a plasma cell disorder associated with poor outcomes, especially when the heart is involved. The characteristics of left atrial (LA) function and its prognostic implications in cardiac amyloidosis (CA) have not been fully investigated. METHODS: Between April 2014 and June 2019, 93 patients with a diagnosis of CA, normal left ventricular ejection fraction (LVEF) and sinus rhythm were included. Their clinical, baseline echocardiographic and follow-up data were investigated. LA function, including LA strain and strain rate, was assessed using 2D speckle tracking echocardiography in different LA functional phases. RESULTS: Among all patients, 38 (40.9%) died. Multivariate Cox regression analyses showed that LA mechanics regarding LA reservoir and booster pump functions were independent predictors for overall survival. Traditional echocardiographic parameters for LA structure like LA volume index and LA width were not associated with mortality. Moreover, LA strain and strain rate in reservoir and contractile phases improved the discrimination and goodness of fit of the conventional prognostic model, the Mayo criteria 2004 and 2012, in our study population. Decreased LA mechanics were associated with impaired left ventricular (LV) systolic and diastolic function, and LA reservoir and contractile functions were associated with LA structure. CONCLUSIONS: Assessment of LA reservoir and contractile functions via 2D speckle tracking echocardiographic LA mechanical indices provide clinical and prognostic insights into cardiac light-chain amyloidosis patients, especially those with preserved EF and sinus rhythm. Emphasizing the monitoring of LA function may be beneficial for the prognosis prediction of CA.

Rare NOTCH3 Variants in a Chinese Population-Based Cohort and Its Relationship With Cerebral Small Vessel Disease.

BACKGROUND AND PURPOSE: Researches on rare variants of NOTCH3 in the general Chinese population are lacking. This study aims to describe the spectrum of rare NOTCH3 variants by whole-exome sequencing in a Chinese community-based cohort and to investigate the association between rare NOTCH3 variants and age-related cerebral small vessel disease. METHODS: The cross-sectional study comprised 1065 participants who underwent whole-exome sequencing and brain magnetic resonance imaging. NOTCH3 variants with minor allele frequency<1% in all 4 public population databases (1000 Genomes, ESP6500siv2_ALL, GnomAD_ALL, and GnomAD_EAS) were defined as rare variants. Multivariable linear and logistic regressions were used to investigate the associations between rare NOTCH3 variants and volume of white matter hyperintensities and cerebral small vessel disease burden. Clinical and imaging characteristics of rare NOTCH3 variant carriers were summarized. RESULTS: Sixty-five rare NOTCH3 variants were identified in 147 of 1065 (13.8%) participants, including 57 missense single nucleotide polymorphisms (SNPs), 5 SNPs in splice branching sites, and 3 frameshift deletions. A significantly higher volume of white matter hyperintensities and heavier burden of cerebral small vessel disease was found in carriers of rare NOTCH3 EGFr (epidermal growth factor-like repeats)-involving variants, but not in carriers of EGFr-sparing variants. The carrying rate of rare EGFr-involving NOTCH3 variants in participants with dementia or stroke was significantly higher than those without dementia or stroke (12.4% versus 6.6%, P=0.041). Magnetic resonance imaging signs suggestive of CADASIL were found in 3.4% (5/145) rare EGFr cysteine-sparing NOTCH3 variant carriers but not in 2 cysteine-altering NOTCH3 variant carriers. CONCLUSIONS: Carriers of rare NOTCH3 variants involving the EGFr domain may be genetically predisposed to age-related cerebral small vessel disease in the general Chinese population.

The efficacy of fractional CO2 laser in acne scar treatment: A meta-analysis.

Fractional CO2 laser is a good option for treating acne scars. However, the clinical efficacy of this treatment modality requires further evidence. To perform a meta-analysis to assess clinical improvements in acne scars with fractional CO2 laser and non-CO2 laser therapies. Databases (PubMed, Embase, Cochrane Library) were searched using the search strategy to identify eligible studies. All statistical analyses were performed using the Review Manager 5.0, and a meta-analysis was conducted to assess the effects of fractional CO2 laser used as a treatment for acne scars. Eight studies were included for further analysis. There was no significant difference between fractional CO2 laser and non-CO2 laser therapies in terms of clinical improvement, observer assessment (P = .19), patient assessment (P = .91), and incidence of post-inflammatory hyperpigmentation (P = .69). The subgroup analyses showed that the duration of follow-up had little effect on the evaluation of treatment effect. The efficacy of fractional CO2 laser therapy in acne scars appeared to be equal to that of non-CO2 laser therapies. More well designed randomized controlled trials and more credible and standard evaluation criteria are needed, and the efficiency of combination therapy requires further analysis.

Chitosan-calcium alginate dressing promotes wound healing: A preliminary study.

Dressings are necessary during the process of wound healing. Since the early 1980s, several types of wound dressings have been produced, but they cannot always take into account some effects include antibacterial effect, wound healing promotion, and other properties. In this study, we would like to develop an effective dressing with the above properties, especially accelerating wound healing effect. A chitosan-calcium alginate dressing (CCAD) was developed by coating mixture of chitosan with high-low molecular weight on calcium alginate dressing (CAD). We investigated the structural characteristics of CCAD with Fourier-transform infrared spectroscopy (FTIR) and electron microscopy. The cytotoxicity and antibacterial property were evaluated in vitro using CCK-8 and inhibition zone method. Moisture retention was tested on the skin of Sprague-Dawley (SD) rats, and wound healing studies were performed on a full-thickness skin wound model in SD rats. CCAD showed good moisturizing and antibacterial properties with no cytotoxicity. CCAD could inhibit inflammation by decreasing IL-6, and it could also promote angiogenesis by increasing VEGF, resulting in better wound healing than CAD. CCAD is a better choice in wound care due to its antibacterial property, biocompatibility, moisture retention, healing promotion, and non-cytotoxicity characteristics.

Estrogen Abolishes the Repression Role of gga-miR-221-5p Targeting ELOVL6 and SQLE to Promote Lipid Synthesis in Chicken Liver.

Few studies have been conducted regarding the biological function and regulation role of gga-miR-221-5p in the liver. We compared the conservation of miR-221-5p among species and investigated the expression pattern of gga-miR-221-5p, validating the direct target genes of gga-miR-221-5p by dual luciferase reporter assay, the biological function of gga-miR-221-5p in the liver was studied by gga-miR-221-5p overexpression and inhibition. Furthermore, we explored the regulation of gga-miR-221-5p and its target genes by treatment with estrogen and estrogen antagonists in vivo and in vitro. The results showed that miR-221-5p was highly conserved among species, expressed in all tested tissues and significantly downregulated in peak-laying hen liver compared to pre-laying hen liver. Gga-miR-221-5p could directly target the expression of elongase of very long chain fatty acids 6 (ELOVL6) and squalene epoxidase (SQLE) genes to affect triglyceride and total cholesterol content in the liver. 17ß-estradiol could significantly inhibit the expression of gga-miR-221-5p but promote the expression of ELOVL6 and SQLE genes. In conclusion, the highly conservative gga-miR-221-5p could directly target ELOVL6 and SQLE mRNAs to affect the level of intracellular triglyceride and total cholesterol. Meanwhile, 17ß-estradiol could repress the expression of gga-miR-221-5p but increase the expression of ELOVL6 and SQLE, therefore promoting the synthesis of intracellular triglyceride and cholesterol levels in the liver of egg-laying chicken.

Increased Expression of Caspase-12 After Experimental Subarachnoid Hemorrhage.

Convincing evidences have proved that apoptosis plays a vital role in the pathogenesis of early and delayed brain injury following subarachnoid hemorrhage (SAH). Recently, a novel caspase-12-mediated apoptotic pathway has been reported to be induced by excess endoplasmic reticulum (ER) stress. Extensive protein damage occurs after SAH, which may trigger ER stress-associated apoptotic pathway. Thus, we hypothesized that caspase-12, as the major molecular marker of this novel apoptotic pathway, may be activated and involved in the pathogenesis of apoptotic injury after SAH. This study sought to investigate the changes of caspase-12 expressions in both in vitro and in vivo SAH models. Western blot analysis found significantly increased protein expressions of both pro- and active forms of caspase-12 after SAH. Quantitative real-time PCR and immunohistochemistry assays confirmed elevated caspase-12 level after SAH in vivo. Further, double immunofluorescence staining revealed obvious caspase-12 over-expression in both cortical neurons and astrocytes. Moreover, immunofluorescent co-staining in vivo demonstrated that neural cells with high immunoreactivity of caspase-12 also expressed caspase-3, and dual-immunofluorescent staining for caspase-12 and TUNEL in vitro showed that TUNEL-positive cells were more likely to exhibit higher caspase-12 immunoreactivity, indicating a potential contribution of caspase-12 activation to apoptosis in SAH. Collectively, our results showed significant upregulation of caspase-12 expression after experimental SAH. These findings also offer important implications for further investigations of the therapeutic potential of caspase-12 associated apoptosis in SAH.

Expression and Cell Distribution of SENP3 in Brain Tissue After Traumatic Brain Injury in Mice: A Pilot Study.

SUMO-specific proteases 3 (SENP3) is a member of the small ubiquitin-like modifier-specific protease family and deconjugates SUMO2/3 from protein substrates. To date, the expression and function of SENP3 in traumatic brain injury (TBI) are unclear. The present study examined dynamic changes in SENP3 expression in the cerebral cortex and in its cellular localization, using an acute TBI model in adult mice. SENP3 expression was examined at 3, 6, 12, 24 h, 3, and 5 days after TBI using Western Blot analysis and quantitative real-time PCR. Immunohistochemistry and immunofluorescence were examined to detect SENP3 localization. Western Blot indicated that SENP3 protein levels gradually increased from 3 h after TBI and peaked at 24 h. Quantitative real-time PCR demonstrated a gradual increase in SENP3 expression, which peaked 12 h after TBI and declined subsequently. Immunohistochemical staining demonstrated that SENP3-positive cells were observed in both the sham and 24 h post-TBI groups. However, robust expression of SENP3 was seldom observed in the sham group, while it was notably enhanced after TBI. Furthermore, immunofluorescence results revealed that the expression of SENP3 increased more significantly in neurons at day 1 after TBI compared with sham group and less significantly in astrocytes and microglia. Moreover, the SENP3-positive cells that were co-expressed with NeuN also expressed caspase-3, indicating a potential correlation between SENP3 and apoptosis after TBI. Collectively, our results showed obvious up-regulation of SENP3 expression in the brain after TBI, especially in the neurons. However, the full role of SENP3 and its therapeutic potential in TBI needs further investigation.

Temozolomide and irradiation combined treatment-induced Nrf2 activation increases chemoradiation sensitivity in human glioblastoma cells.

Resistance to chemoradiotherapy is a major obstacle to successful treatment of glioblastoma. Recently, the role of NF-E2-related factor 2 (Nrf2) in enhancing chemoradiation sensitivity has been reported in several types of cancers. Here, we investigated whether temozolomide (TMZ) and irradiation (IR) combined treatment induced Nrf2 activation in human glioblastoma cells. And we further performed a preliminary study about the effect of Nrf2 on chemoradiation sensitivity. Immunohistochemical staining for Nrf2 in paired clinical specimens showed that TMZ and IR combined treatment increased the expression and nuclear localization of Nrf2 in human glioblastoma tissues. Moreover, we found nuclear Nrf2 expression in the glioblastoma tissues obtained from the patients undergoing TMZ and IR combined treatment was associated with the time to tumor recurrence. In vitro, we further verified these findings. First, we detected increased nuclear localization of Nrf2 following treatment with TMZ+IR in human glioblastoma cell lines. Second, we demonstrated TMZ+IR increased the levels of Nrf2 protein in both nuclear and cytoplasmic fractions of U251 cells and induced Nrf2 target genes expression. Finally, downregulating Nrf2 expression increased TMZ+IR-induced cell death in the U251 cells. These findings suggest TMZ+IR combined treatment induces Nrf2 activation in human glioblastoma cells. The activation of Nrf2 may be associate with enhancing chemoradiation sensitivity in human glioblastoma cell. Blocking Nrf2 activation may be a promising method enhancing chemoradiation sensitivity of glioblastoma cells.

Biphasic activation of nuclear factor kappa B and expression of p65 and c-Rel after traumatic brain injury in rats.

BACKGROUND AND OBJECT: Nuclear factor kappa B (NF-κB) functions as a key regulator in the central nervous system and regulates the inflammatory pathway. There are two peaks of cerebral NF-κB activation after neonatal hypoxia-ischemia and subarachnoid hemorrhage. Our previous studies found that NF-κB activity was up-regulated at an early stage and remained elevated at day 7 after traumatic brain injury (TBI). However, data are lacking regarding an overview of NF-κB activity and expression of NF-κB subunits after TBI. Hence, the current study was designed to detect the time course of NF-κB activation and expression of NF-κB p65 and c-Rel subunits around the contused cortex following TBI. METHODS: Adult Sprague-Dawley rats were randomly divided into sham and TBI groups at different time points. A TBI model was induced, and then the NF-κB DNA-binding activity in the surrounding areas of injured brain was detected by electrophoretic mobility shift assay. Western blotting was used to measure the protein levels of p65 and c-Rel in the nucleus. The concentrations of tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) were detected by enzyme-linked immunosorbent assay. Moreover, the distribution of c-Rel and p65 was examined by immunohistochemical studies. RESULTS: There were double peaks of cerebral cortical NF-κB activity, at 3 and 10 days post-injury. Additionally, protein levels of p65 were found to be elevated and peaked at 3 days after TBI, while levels of c-Rel were elevated significantly during the later phase of injury. Furthermore, TNF-α and IL-1ß concentrations also showed a biphasic increase. CONCLUSIONS: Biphasic activation of NF-κB could be induced after experimental TBI in rats. NF-κB p65 and c-Rel subunits were elevated at different post-TBI time periods, leading to a hypothesis that different NF-κB subunits might be involved in different pathophysiological processes after TBI.

Mechanism of fibroblast growth factor 1 regulating fatty liver disorder in mule ducks.

Mule ducks tend to accumulate abundant fat in their livers via feeding, which leads to the formation of a fatty liver that is several times larger than a normal liver. However, the mechanism underlying fatty liver formation has not yet been elucidated. Fibroblast growth factor 1 (FGF1), a member of the FGF superfamily, is involved in cellular lipid metabolism and mitosis. This study aims to investigate the regulatory effect of FGF1 on lipid metabolism disorders induced by complex fatty acids in primary mule duck liver cells and elucidate the underlying molecular mechanism. Hepatocytes were induced by adding 1,500:750 µmol/L oleic and palmitic acid concentrations for 36 h, which were stimulated with FGF1 concentrations of 0, 10, 100, and 1000 ng/mL for 12 h. The results showed that FGF1 significantly reduced the hepatic lipid droplet deposition and triglyceride content induced by complex fatty acids; it also reduced oxidative stress; decreased reactive oxygen species fluorescence intensity and malondialdehyde content; upregulated the expression of antioxidant factors nuclear factor erythroid 2 related factor 2 (Nrf2), HO-1, and NQO-1; significantly enhanced liver cell activity; promoted cell cycle progression; inhibited cell apoptosis; upregulated cyclin-dependent kinase 1 (CDK1) and BCL-2 mRNA expression; and downregulated Bax and Caspase-3 expression. In addition, FGF1 promoted AMPK phosphorylation, activated the AMPK pathway, upregulated AMPK gene expression, and downregulated the expression of SREBP1 and ACC1 genes, thereby alleviating excessive fat accumulation in liver cells induced by complex fatty acids. In summary, FGF1 may alleviate lipid metabolism disorders induced by complex fatty acids in primary mule duck liver cells by activating the AMPK signaling pathway.

Association of Rare NOTCH3 Variants With Prevalent and Incident Stroke and Dementia in the General Population.

BACKGROUND: It is uncertain whether rare NOTCH3 variants are associated with stroke and dementia in the general population and whether they lead to alterations in cognitive function. This study aims to determine the associations of rare NOTCH3 variants with prevalent and incident stroke and dementia, as well as cognitive function changes. METHODS AND RESULTS: In the prospective community-based Shunyi Study, a total of 1007 participants were included in the baseline analysis. For the follow-up analysis, 1007 participants were included in the stroke analysis, and 870 participants in the dementia analysis. All participants underwent baseline brain magnetic resonance imaging, carotid ultrasound, and whole exome sequencing. Rare NOTCH3 variants were defined as variants with minor allele frequency <1%. A total of 137 rare NOTCH3 carriers were enrolled in the baseline study. At baseline, rare NOTCH3 variant carriers had higher rates of stroke (8.8% versus 5.6%) and dementia (2.9% versus 0.8%) compared with noncarriers. After adjustment for associated risk factors, the epidermal growth factor-like repeats (EGFr)-involving rare NOTCH3 variants were associated with a higher risk of prevalent stroke (odds ratio [OR], 2.697 [95% CI, 1.266-5.745]; P=0.040) and dementia (OR, 8.498 [95% CI, 1.727-41.812]; P=0.032). After 5 years of follow-up, we did not find that the rare NOTCH3 variants increased the risk of incident stroke and dementia. There was no statistical difference in the change in longitudinal cognitive scale scores. CONCLUSIONS: Rare NOTCH3 EGFr-involving variants are genetic risk factors for stroke and dementia in the general Chinese population.

Activation of metabotropic glutamate receptor 5 reduces the secondary brain injury after traumatic brain injury in rats.

A wealth of evidence has shown that microglia-associated neuro-inflammation is involved in the secondary brain injury contributed to the poor outcome after traumatic brain injury (TBI). In vitro studies were reported that activation of metabotropic glutamate receptor 5 (mGluR5) could inhibit the microglia-associated inflammation in response to lipopolysaccharide and our previous study indicated that mGluR5 was expressed in activated microglia following TBI. However, there is little known about whether mGluR5 activation can provide neuro-protection and reduce microglia-associated neuro-inflammation in rats after TBI. The goal of the present study was to investigate the effects of mGluR5 activation with selective agonist CHPG, on cerebral edema, neuronal degeneration, microglia activation and the releasing of pro-inflammatory cytokines, in a rat model of TBI. Rats were randomly distributed into various subgroups undergoing the sham surgery or TBI procedures, and 250 nmol of CHPG or equal volume vehicle was given through intracerebroventricular injection at 30 min post-TBI. All rats were sacrificed at 24 h after TBI for the further measurements. Our data indicated that post-TBI treatment with CHPG could significantly reduce the secondary brain injury characterized by the cerebral edema and neuronal degeneration, lead to the inhibition of microglia activation and decrease the expression of pro-inflammatory cytokines in both mRNA transcription and protein synthesis. These results provide the substantial evidence that activation of mGluR5 reduces the secondary brain injury after TBI, in part, through modulating microglia-associated neuro-inflammation.

Expression of the NLRP3 inflammasome in cerebral cortex after traumatic brain injury in a rat model.

Inflammatory response plays an important role in the pathogenesis of secondary damage after traumatic brain injury (TBI). The inflammasome is a multiprotein complex involved in innate immunity and a number of studies have suggested that the inflammasome plays a critical role in a host inflammatory signaling. Nucleotide-binding domain, leucine-rich repeat, pyrin domain containing 3 (NLRP3) is a key component of the NLRP3-inflammasome, which also includes apoptotic speck-containing protein (ASC) with a cysteine protease (caspase)-activating recruitment domain and pro-caspase1. Activation of the NLRP3-inflammasome causes the processing and release of the interleukin 1 beta (IL-1ß) and interleukin 18 (IL-18). Based on this, we hypothesized that the NLRP3-inflammasome could participate in the inflammatory response following TBI. However, the expression of NLRP3-inflammasome in cerebral cortex after TBI is not well known. Rats were randomly divided into control, sham and TBI groups (including 6 h, 1 day, 3 day and 7 day sub-group). TBI model was induced, and animals were sacrificed at each time point respectively. The expression of NLRP3-inflammasome was measured by quantitative real-time polymerase chain reaction, western blot and immunohistochemistry respectively. Immunofluorescent double labeling was performed to identify the cell types of NLRP3-inflammasome's expression. Moreover, enzyme linked immunosorbent assay was used to detect the alterations of IL-1ß and IL-18 at each time point post-injury. The results showed that, TBI could induce assembly of NLRP3-inflammasome complex, increased expression of ASC, activation of caspase1, and processing of IL-1ß and IL-18. These results suggested that NLRP3-inflammasome might play an important role in the inflammation induced by TBI and could be a target for TBI therapy.