The Development and Application of Vegetable Genomics Increase the Efficiency of Exploring New Gene Resources for Vegetables.

Vegetables, as indispensable non-staple foods in people's daily diet, provide a variety of essential vitamins, minerals, and other nutrients, as well as special phytochemicals, which are recognized as functional components for human nutritional balance or medicinal purposes [...].

Establishment of epidemiological cut-off values for eravacycline, against Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Acinetobacter baumannii and Staphylococcus aureus.

OBJECTIVES: To establish the epidemiology cut-off (ECOFF) values of eravacycline against Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Acinetobacter baumannii and Staphylococcus aureus, from a multi-centre study in China. METHODS: We collected 2500 clinical isolates from five hospitals in China from 2017 to 2020. The MICs of eravacycline were determined using broth microdilution. The ECOFF values of eravacycline against the five species commonly causing cIAIs were calculated using visual estimation and ECOFFinder following the EUCAST guideline. RESULTS: The MICs of eravacycline against all the strains were in the range of 0.004-16 mg/L. The ECOFF values of eravacycline were 0.5 mg/L for E. coli, 2 mg/L for K. pneumonia and E. cloacae, and 0.25 mg/L for A. baumannii and S. aureus, consistent with the newest EUCAST publication of eravacycline ECOFF values for the populations. No discrepancy was found between the visually estimated and 99.00% ECOFF values calculated using ECOFFinder. CONCLUSIONS: The determined ECOFF values of eravacycline against the five species can assist in distinguishing wild-type from non-wild-type strains. Given its promising activity, eravacycline may represent a member of the tetracycline class in treating cIAIs caused by commonly encountered Gram-negative and Gram-positive pathogens.

A new synonym of Rhododendronleishanicum (subg. Hymenanthes) from China (Ericaceae).

Based on a critical examination of type specimens, images of living plants, and the literature has shown Rhododendronoligocarpum to be conspecific with R.leishanicum. Although slight variations in corolla colour exist amongst different populations of R.oligocarpum, it does not serve as a key distinguishing trait. Therefore, we reduced R.oligocarpum to a synonym of R.leishanicum, and recommend placing it in Subsection Maculifera.

Utilizing fMRI to Guide TMS Targets: the Reliability and Sensitivity of fMRI Metrics at 3 T and 1.5 T.

US Food and Drug Administration (FDA) cleared a Transcranial Magnetic Stimulation (TMS) system with functional Magnetic Resonance Imaging-guided (fMRI) individualized treatment protocol for major depressive disorder, which employs resting state-fMRI (RS-fMRI) functional connectivity (FC) to pinpoint the target individually to increase the accuracy and effeteness of the stimulation. Furthermore, task activation-guided TMS, as well as the use of RS-fMRI local metrics for targeted the specific abnormal brain regions, are considered a precise scheme for TMS targeting. Since 1.5 T MRI is more available in hospitals, systematic evaluation of the test-retest reliability and sensitivity of fMRI metrics on 1.5 T and 3 T MRI may provide reference for the application of fMRI-guided individualized-precise TMS stimulation. Twenty participants underwent three RS-fMRI scans and one scan of finger-tapping task fMRI with self-initiated (SI) and visual-guided (VG) conditions at both 3 T and 1.5 T. Then the location reliability derived by FC (with three seed regions) and peak activation were assessed by intra-individual distance. The test-retest reliability and sensitivity of five RS-fMRI local metrics were evaluated using intra-class correlation and effect size, separately. The intra-individual distance of peak activation location between 1.5 T and 3 T was 15.8 mm and 19 mm for two conditions, respectively. The intra-individual distance for the FC derived targets at 1.5 T was 9.6-31.2 mm, compared to that of 3 T (7.6-31.1 mm). The test-retest reliability and sensitivity of RS-fMRI local metrics showed similar trends on 1.5 T and 3 T. These findings hasten the application of fMRI-guided individualized TMS treatment in clinical practice.

Biomaterials science and surface engineering strategies for dental peri-implantitis management.

Peri-implantitis is a bacterial infection that causes soft tissue inflammatory lesions and alveolar bone resorption, ultimately resulting in implant failure. Dental implants for clinical use barely have antibacterial properties, and bacterial colonization and biofilm formation on the dental implants are major causes of peri-implantitis. Treatment strategies such as mechanical debridement and antibiotic therapy have been used to remove dental plaque. However, it is particularly important to prevent the occurrence of peri-implantitis rather than treatment. Therefore, the current research spot has focused on improving the antibacterial properties of dental implants, such as the construction of specific micro-nano surface texture, the introduction of diverse functional coatings, or the application of materials with intrinsic antibacterial properties. The aforementioned antibacterial surfaces can be incorporated with bioactive molecules, metallic nanoparticles, or other functional components to further enhance the osteogenic properties and accelerate the healing process. In this review, we summarize the recent developments in biomaterial science and the modification strategies applied to dental implants to inhibit biofilm formation and facilitate bone-implant integration. Furthermore, we summarized the obstacles existing in the process of laboratory research to reach the clinic products, and propose corresponding directions for future developments and research perspectives, so that to provide insights into the rational design and construction of dental implants with the aim to balance antibacterial efficacy, biological safety, and osteogenic property.

MRI-based vertebral bone quality score as a novel bone status marker of patients with adolescent idiopathic scoliosis.

To investigate the application of MRI-based vertebral bone quality (VBQ) score in assessing bone mineral density (BMD) for patients with adolescent idiopathic scoliosis (AIS). We reviewed the data of AIS patients between January 2021 and October 2023 with MRI, whole-spine plain radiographs, quantitative computed tomography (QCT) and general information. VBQ score was calculated using T1-weighted MRI. Univariate analysis was applied to present the differences between variables of patients with normal BMD group (QCT Z-score > - 2.0) and low BMD group (QCT Z-score ≤ - 2.0). The correlation between VBQ score and QCT Z-score was analyzed with Pearson correlation test. A multivariate logistic regression model was used to determine the independent factors related to low BMD. Receiver operating characteristic curve (ROC) was drawn to analyze the diagnostic performance of VBQ score in distinguishing low BMD. A total of 136 AIS patients (mean age was 14.84 ± 2.10 years) were included, of which 41 had low BMD. The low BMD group had a significantly higher VBQ score than that in normal group (3.48 ± 0.85 vs. 2.62 ± 0.62, P < 0.001). The VBQ score was significantly negative correlated with QCT Z score (r = - 0.454, P < 0.001). On multivariate analysis, VBQ score was independently associated with low BMD (OR: 4.134, 95% CI 2.136-8.000, P < 0.001). The area under the ROC curve indicated that the diagnostic accuracy of the VBQ score for predicting low BMD was 81%. A sensitivity of 65.9% with a specificity of 88.4% could be achieved for distinguishing low BMD by setting the VBQ score cutoff as 3.18. The novel VBQ score was a promising tool in distinguishing low BMD in patients with AIS and could be useful as opportunistic assessment for screening and complementary evaluation to QCT before surgery.

A Study on the Application of Recombinant Factor C (rFC) Assay Using Biopharmaceuticals.

Gram-negative bacterial endotoxins can cause pathophysiological effects such as high fever when introduced into the bloodstream. Therefore, endotoxin testing is necessary when producing injectable pharmaceuticals. The pharmaceutical industry has widely used Limulus amebocyte lysate (LAL) to certify product quality. However, ethical concerns have been raised and the increasing scarcity of Limulus polyphemus necessitates the development of novel testing techniques. Recombinant factor C (rFC) was developed using genetic engineering techniques. The aim of this study was to investigate the validity of rFC testing and compare it with the LAL method. The specificity, linearity, accuracy, precision, and robustness of the rFC assay were evaluated. After validation, the rFC assay was found to be suitable for endotoxin detection. We compared the accuracy of the rFC and LAL assays using reference standard endotoxin. The rFC assay was as accurate as the LAL assay. We also compared the two assays using biopharmaceuticals. Greater interference occurred in some samples when the rFC assay was used than when the LAL assay was used. However, the rFC assay overcame the interference when the samples were diluted. Overall, we suggest that rFC can be applied to test biopharmaceuticals.

A nanopore-based cucumber genome assembly reveals structural variations at two QTLs controlling hypocotyl elongation.

The Xishuangbanna (XIS) cucumber (Cucumis sativus var. xishuangbannanesis) is a semiwild variety that has many distinct agronomic traits. Here, long reads generated by Nanopore sequencing technology helped assembling a high-quality genome (contig N50 = 8.7 Mb) of landrace XIS49. A total of 10,036 structural/sequence variations (SVs) were identified when comparing with Chinese Long (CL), and known SVs controlling spines, tubercles, and carpel number were confirmed in XIS49 genome. Two QTLs of hypocotyl elongation under low light, SH3.1 and SH6.1, were fine-mapped using introgression lines (donor parent, XIS49; recurrent parent, CL). SH3.1 encodes a red-light receptor Phytochrome B (PhyB, CsaV3_3G015190). A ∼4 kb region with large deletion and highly divergent regions (HDRs) were identified in the promoter of the PhyB gene in XIS49. Loss of function of this PhyB caused a super-long hypocotyl phenotype. SH6.1 encodes a CCCH-type zinc finger protein FRIGIDA-ESSENTIAL LIKE (FEL, CsaV3_6G050300). FEL negatively regulated hypocotyl elongation but it was transcriptionally suppressed by long terminal repeats retrotransposon insertion in CL cucumber. Mechanistically, FEL physically binds to the promoter of CONSTITUTIVE PHOTOMORPHOGENIC 1a (COP1a), regulating the expression of COP1a and the downstream hypocotyl elongation. These above results demonstrate the genetic mechanism of cucumber hypocotyl elongation under low light.

Modulation of photonic skyrmions in a thin metal film structure.

Photonic skyrmions have been a hot topic in recent years. However, modulating the spin distributions of the skyrmions is still a challenging topic. In this paper, we investigate the detailed spin distributions of photonic skyrmions in thin metal film sandwiched by different dielectrics. We find that the ratios of different spin components can be adjusted by the thickness of the metal film, while the absolute value of total spin can be controlled by the frequency of the light source. Therefore, by choosing proper metal thickness in the preparation process and certain beam frequency in actual experiment, we can get the exact type of spin distribution we prefer. In addition, when the dielectric layers are arranged asymmetrically, the spin distributions can also be modulated significantly by adjustig the ratio of the dielectric constants of the upper and lower dielectric layers. Our results provide a new pathway for the modulation of photonic skyrmions.

Cell-free DNA testing for early hepatocellular carcinoma surveillance.

BACKGROUND: Liver cirrhosis (LC) is the highest risk factor for hepatocellular carcinoma (HCC) development worldwide. The efficacy of the guideline-recommended surveillance methods for patients with LC remains unpromising. METHODS: A total of 4367 LCs not previously known to have HCC and 510 HCCs from 16 hospitals across 11 provinces of China were recruited in this multi-center, large-scale, cross-sectional study. Participants were divided into Stage Ⅰ cohort (510 HCCs and 2074 LCs) and Stage Ⅱ cohort (2293 LCs) according to their enrollment time and underwent Tri-phasic CT/enhanced MRI, US, AFP, and cell-free DNA (cfDNA). A screening model called PreCar Score was established based on five features of cfDNA using Stage Ⅰ cohort. Surveillance performance of PreCar Score alone or in combination with US/AFP was evaluated in Stage Ⅱ cohort. FINDINGS: PreCar Score showed a significantly higher sensitivity for the detection of early/very early HCC (Barcelona stage A/0) in contrast to US (sensitivity of 51.32% [95% CI: 39.66%-62.84%] at 95.53% [95% CI: 94.62%-96.38%] specificity for PreCar Score; sensitivity of 23.68% [95% CI: 14.99%-35.07%] at 99.37% [95% CI: 98.91%-99.64%] specificity for US) (P < 0.01, Fisher's exact test). PreCar Score plus US further achieved a higher sensitivity of 60.53% at 95.08% specificity for early/very early HCC screening. INTERPRETATION: Our study developed and validated a cfDNA-based screening tool (PreCar Score) for HCC in cohorts at high risk. The combination of PreCar Score and US can serve as a promising and practical strategy for routine HCC care. FUNDING: A full list of funding bodies that contributed to this study can be found in Acknowledgments section.

OXCT1 regulates hippocampal neurogenesis and alleviates cognitive impairment via the Akt/GSK-3ß/ß-catenin pathway after subarachnoid hemorrhage.

BACKGROUND: Subarachnoid hemorrhage (SAH) is a life-threatening neurological disease that usually has a poor prognosis. Neurogenesis is a potential therapeutic target for brain injury. Ketone metabolism also plays neuroprotective roles in many neurological disorders. OXCT1 (3-Oxoacid CoA-Transferase 1) is the rate-limiting enzyme of ketone body oxidation. In this study, we explored whether increasing ketone oxidation by upregulating OXCT1 in neurons could promote neurogenesis after SAH, and evaluated the potential mechanism involved in this process. METHODS: The ß-hydroxybutyrate content was measured using an enzymatic colorimetric assay. Adeno-associated virus targeting neurons was injected to overexpress OXCT1, and the expression and localization of proteins were evaluated by western blotting and immunofluorescence staining. Adult hippocampal neurogenesis was evaluated by dual staining with doublecortin and 5-Ethynyl-2'-Deoxyuridine. LY294002 was intracerebroventricularly administered to inhibit Akt activity. The Morris water maze and Y-maze tests were employed to assess cognitive function after SAH. RESULTS: The results showed that OXCT1 expression and hippocampal neurogenesis significantly decreased in the early stage of SAH. Overexpression of OXCT1 successfully increased hippocampal neurogenesis via activation of Akt/GSK-3ß/ß-catenin signaling and improved cognitive function, both of which were reversed by administration of LY294002. CONCLUSIONS: OXCT1 regulated hippocampal ketone body metabolism and increased neurogenesis through mechanisms mediated by the Akt/GSK-3ß/ß-catenin pathway, improving cognitive impairment after SAH.

Optimising first-line subtyping-based therapy in triple-negative breast cancer (FUTURE-SUPER): a multi-cohort, randomised, phase 2 trial.

BACKGROUND: Triple-negative breast cancers display heterogeneity in molecular drivers and immune traits. We previously classified triple-negative breast cancers into four subtypes: luminal androgen receptor (LAR), immunomodulatory, basal-like immune-suppressed (BLIS), and mesenchymal-like (MES). Here, we aimed to evaluate the efficacy and safety of subtyping-based therapy in the first-line treatment of triple-negative breast cancer. METHODS: FUTURE-SUPER is an ongoing, open-label, randomised, controlled phase 2 trial being conducted at Fudan University Shanghai Cancer Center (FUSCC), Shanghai, China. Eligible participants were females aged 18-70 years, with an Eastern Cooperative Oncology Group performance status of 0-1, and histologically confirmed, untreated metastatic or recurrent triple-negative breast cancer. After categorising participants into five cohorts according to molecular subtype and genomic biomarkers, participants were randomly assigned (1:1) with a block size of 4, stratified by subtype, to receive, in 28-day cycles, nab-paclitaxel (100 mg/m2, intravenously on days 1, 8, and 15) alone (control group) or with a subtyping-based regimen (subtyping-based group): pyrotinib (400 mg orally daily) for the LAR-HER2mut subtype, everolimus (10 mg orally daily) for the LAR-PI3K/AKTmut and MES-PI3K/AKTmut subtypes, camrelizumab (200 mg intravenously on days 1 and 15) and famitinib (20 mg orally daily) for the immunomodulatory subtype, and bevacizumab (10 mg/kg intravenously on days 1 and 15) for the BLIS/MES-PI3K/AKTWT subtype. The primary endpoint was investigator-assessed progression-free survival for the pooled subtyping-based group versus the control group in the intention-to-treat population (all randomly assigned participants). Safety was analysed in all patients with safety records who received at least one dose of study drug. This study is registered with ClinicalTrials.gov (NCT04395989). FINDINGS: Between July 28, 2020, and Oct 16, 2022, 139 female participants were enrolled and randomly assigned to the subtyping-based group (n=69) or control group (n=70). At the data cutoff (May 31, 2023), the median follow-up was 22·5 months (IQR 15·2-29·0). Median progression-free survival was significantly longer in the pooled subtyping-based group (11·3 months [95% CI 8·6-15·2]) than in the control group (5·8 months [4·0-6·7]; hazard ratio 0·44 [95% CI 0·30-0·65]; p<0·0001). The most common grade 3-4 treatment-related adverse events were neutropenia (21 [30%] of 69 in the pooled subtyping-based group vs 16 [23%] of 70 in the control group), anaemia (five [7%] vs none), and increased alanine aminotransferase (four [6%] vs one [1%]). Treatment-related serious adverse events were reported for seven (10%) of 69 patients in the subtyping-based group and none in the control group. No treatment-related deaths were reported in either group. INTERPRETATION: These findings highlight the potential clinical benefits of using molecular subtype-based treatment optimisation in patients with triple-negative breast cancer, suggesting a path for further clinical investigation. Phase 3 randomised clinical trials assessing the efficacy of subtyping-based regimens are now underway. FUNDING: National Natural Science Foundation of China, Natural Science Foundation of Shanghai, Shanghai Hospital Development Center, and Jiangsu Hengrui Pharmaceuticals. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.

N-alkylamides from Litsea cubeba (Lour.) Pers. with potential anti-inflammatory activity.

Six amides, including a new N-alkylamide (1), four known N-alkylamides (2-5) and one nicotinamide (6) were isolated from Litsea cubeba (Lour.) Pers., which is a pioneer herb traditionally utilized in medicine. Their structures were elucidated on the basis of 1D and 2D NMR experiments and by comparison of their spectroscopic and physical data with the literature values. Cubebamide (1) is a new cinnamoyltyraminealkylamide and possessed obvious anti-inflammatory activity against NO production with IC50 values of 18.45 µM. Further in-depth pharmacophore-based virtual screening and molecular docking were carried out to reveal the binding mode of the active compound inside the 5-LOX enzyme. The results indicate that L. cubeba, and the isolated amides might be useful in the development of lead compounds for the prevention of inflammatory diseases.

PARIS undergoes liquid-liquid phase separation and poly(ADP-ribose)-mediated solidification.

ZNF746 was identified as parkin-interacting substrate (PARIS). Investigating its pathophysiological properties, we find that PARIS undergoes liquid-liquid phase separation (LLPS) and amorphous solid formation. The N-terminal low complexity domain 1 (LCD1) of PARIS is required for LLPS, whereas the C-terminal prion-like domain (PrLD) drives the transition from liquid to solid phase. In addition, we observe that poly(ADP-ribose) (PAR) strongly binds to the C-terminus of PARIS near the PrLD, accelerating its LLPS and solidification. N-Methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced PAR formation leads to PARIS oligomerization in human iPSC-derived dopaminergic neurons that is prevented by the PARP inhibitor, ABT-888. Furthermore, SDS-resistant PARIS species are observed in the substantia nigra (SN) of aged mice overexpressing wild-type PARIS, but not with a PAR binding-deficient PARIS mutant. PARIS solidification is also found in the SN of mice injected with preformed fibrils of α-synuclein (α-syn PFF) and adult mice with a conditional knockout (KO) of parkin, but not if α-syn PFF is injected into mice deficient for PARP1. Herein, we demonstrate that PARIS undergoes LLPS and PAR-mediated solidification in models of Parkinson's disease.

Absorption, translocation, and accumulation of the fungicide triadimefon in Pak choi (Brassica rapa var chinensis), pepper (Capsicum annuum), and cucumber (Cucumis sativus).

Triadimefon is a typical systemic fungicide that is widely used in the management of powdery mildew, rust disease, and southern blight. In this study, we measured fungicide residue to profile its absorption, translocation, and accumulation in three representative vegetable crops (Pak choi, cucumber, and pepper) after over-application. The fungicides were applied through entire-plant spraying (EPS), root-irrigation (RI), and middle-leaf-daubing (MLD). The half-life of triadimefon depends on the application method and plant species. In EPS, the half-life was 5.42 days (Pak choi), 6.86 days (cucumber), and 6.73 days (pepper), while in RI it was 4.39 days (Pak choi), 6.30 days (cucumber), and 5.98 days (pepper). In the EPS treatment, triadimefon is translocated both upward/outside and downward/inner-side from the daubed leaves in all the three vegetable crops. The transfer amount to each organ reached a peak on the 2nd day after fungicide application. The mesophyll of Pak choi exhibited a higher fungicide deposition compared to the petiole. In cucumber and pepper, the leaves demonstrated the highest accumulation of triadimefon (approximately 0.3-0.5 mg·kg-1), followed by stems. Roots and fruits displayed the lowest levels of triadimefon accumulation. Furthermore, triadimefon was found to have an impact on chlorophyll content, root activity, as well as the activity of superoxide dismutase and catalase in Pak choi, indicating its potential as a plant growth regulator. These aforementioned studies provide novel insights for the safe and efficient application of triadimefon in the production of Pak choi, cucumber, and pepper.

Spatiotemporal informer: A new approach based on spatiotemporal embedding and attention for air quality forecasting.

Accurate prediction of air pollution is essential for public health protection. Air quality, however, is difficult to predict due to the complex dynamics, and its accurate forecast still remains a challenge. This study suggests a spatiotemporal Informer model, which uses a new spatiotemporal embedding and spatiotemporal attention, to improve AQI forecast accuracy. In the first phase of the proposed forecast mechanism, the input data is transformed by the spatiotemporal embedding. Next, the spatiotemporal attention is applied to extract spatiotemporal features from the embedded data. The final forecast is obtained based on the attention tensors. In the proposed forecast model, the input is a 3-dimensional data that consists of air quality data (AQI, PM2.5, O3, SO2, NO2, CO) and geographic information, and the output is a multi-positional, multi-temporal data that shows the AQI forecast result of all the monitoring stations in the study area. The proposed forecast model was evaluated by air quality data of 34 monitoring stations in Beijing, China. Experiments showed that the proposed forecast model could provide highly accurate AQI forecast: the average of MAPE values for from 1 h to 20 h ahead forecast was 11.61%, and it was much smaller than other models. Moreover, the proposed model provided a highly accurate and stable forecast even at the extreme points. These results demonstrated that the proposed spatiotemporal embedding and attention techniques could sufficiently capture the spatiotemporal correlation characteristics of air quality data, and that the proposed spatiotemporal Informer could be successfully applied for air quality forecasting.

Multiple Myeloma: Case of a "Moving" Sternal Wire.

Multiple myeloma generally occurs in older adults, with the clonal proliferation of plasma cells and accumulation of monoclonal protein resulting in a broad range of clinical manifestations and complications, including hypercalcemia, renal dysfunction, anaemia, and bone destruction (termed CRAB features). A 64-year-old man with no history of malignancy presented with an enlarging precordial lump occurring three years post-sternotomy for uneventful coronary artery bypass grafting surgery. Initial investigations showed anaemia and impaired renal function. Multimodal imaging performed for further evaluation showcases the radio-pathological features which can be encountered in haematological malignancy. Subsequent percutaneous biopsy confirmed an underlying plasma cell neoplasm, and a diagnosis of multiple myeloma was achieved. The prompt resolution of the lesions upon the initiation of treatment highlights the importance of early diagnosis and treatment.

Inhibition of ACAA1 Restrains Proliferation and Potentiates the Response to CDK4/6 Inhibitors in Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer with unfavorable outcomes. Developing therapeutic targets for TNBC remains a challenge. Here, we identified that acetyl-CoA acyltransferase 1 (ACAA1) is highly expressed in the luminal androgen receptor (LAR) subtype of TNBC compared with adjacent normal tissues in our TNBC proteomics dataset. Inhibition of ACAA1 restrained TNBC proliferation and potentiated the response to the cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor abemaciclib. Mechanistically, ACAA1 interacted with CDK4, and the inhibition of ACAA1 blocked RB transcriptional corepressor 1 (RB1) phosphorylation, resulting in G1-S cell-cycle arrest. Importantly, trimetazidine, a traditional drug for ischemic heart disease, caused a decrease in ACAA1 protein levels and enhanced the efficacy of abemaciclib in preclinical TNBC models. In conclusion, this study identifies that ACAA1 is a therapeutic target in TNBC and suggests the combination of trimetazidine and abemaciclib could be beneficial for ACAA1-high TNBCs. SIGNIFICANCE: ACAA1 is highly expressed in TNBC, serving as a potential therapeutic target in ACAA1-high tumors and a predictive biomarker of resistance to CDK4/6 inhibitors for RB1-proficient patients.

Increased NOX2 expression in astrocytes leads to eNOS uncoupling through dihydrofolate reductase in endothelial cells after subarachnoid hemorrhage.

Introduction: Endothelial nitric oxide synthase (eNOS) uncoupling plays a significant role in acute vasoconstriction during early brain injury (EBI) after subarachnoid hemorrhage (SAH). Astrocytes in the neurovascular unit extend their foot processes around endothelia. In our study, we tested the hypothesis that increased nicotinamide adenine dinucleotide phosphate oxidase 2 (NOX2) expression in astrocytes after SAH leads to eNOS uncoupling. Methods: We utilized laser speckle contrast imaging for monitoring cortical blood flow changes in mice, nitric oxide (NO) kits to measure the level of NO, and a co-culture system to study the effect of astrocytes on endothelial cells. Moreover, the protein levels were assessed by Western blot and immunofluorescence staining. We used CCK-8 to measure the viability of astrocytes and endothelial cells, and we used the H2O2 kit to measure the H2O2 released from astrocytes. We used GSK2795039 as an inhibitor of NOX2, whereas lentivirus and adeno-associated virus were used for dihydrofolate reductase (DHFR) knockdown in vivo and in vitro. Results: The expression of NOX2 and the release of H2O2 in astrocytes are increased, which was accompanied by a decrease in endothelial DHFR 12 h after SAH. Moreover, the eNOS monomer/dimer ratio increased, leading to a decrease in NO and acute cerebral ischemia. All of the above were significantly alleviated after the administration of GSK2795039. However, after knocking down DHFR both in vivo and in vitro, the protective effect of GSK2795039 was greatly reversed. Discussion: The increased level of NOX2 in astrocytes contributes to decreased DHFR in endothelial cells, thus aggravating eNOS uncoupling, which is an essential mechanism underlying acute vasoconstriction after SAH.

Neuroprotective mechanisms of OXCT1 via the SIRT3-SOD2 pathway after traumatic brain injury.

BACKGROUND: Ketones are not only utilized to produce energy but also play a neuroprotective role in many neurodegenerative diseases. However, whether this process has an impact on secondary brain damage after traumatic brain injury (TBI) remains unknown. OXCT1 (3-Oxoacid CoA-Transferase 1) is the rate-limiting enzyme in the intra-neuronal utilization of ketones. In this study, we investigated whether reduced expression of OXCT1 after TBI could impact neuroprotective mechanisms and exacerbate neurological dysfunction. MATERIALS AND METHODS: Experimental TBI was induced by a modified version of the weight drop model, it is a model of severe head trauma. Expression of OXCT1 in the injured hippocampus of mice was measured at different time points using immunoblotting assays. The release of abnormal mitochondrial cytochrome c from neurons of the mouse injured lateral hippocampus was measured 1 week after TBI using immunoblotting assays. Neuronal death was assessed by Nissl staining and the level of reactive oxygen species (ROS) within the neurons of the injured lateral hippocampus was assessed by Dihydroethidium staining. RESULTS: OXCT1 was overexpressed in hippocampal neurons by injection of adeno-associated virus into the lateral ventricle. OXCT1 expression levels decreased significantly 1 week post-TBI. After comparing the data obtained from different groups of mice, OXCT1 was found to significantly increase the expression of SIRT3 and reduce the proportion of acetylated SOD2, thus decreasing the production of ROS in the injured hippocampal neurons, reducing neuronal death, and improving cognitive function. CONCLUSIONS: OXCT1 has a critical previously unappreciated protective role in neurological impairment following TBI via the SIR3-SOD2 pathway. These findings highlight the potential of OXCT1 as a simple treatment for patients with TBI.