Adaptive Metabolic Responses Facilitate Blood-Brain Barrier Repair in Ischemic Stroke via BHB-Mediated Epigenetic Modification of ZO-1 Expression.

Adaptive metabolic responses and innate metabolites hold promising therapeutic potential for stroke, while targeted interventions require a thorough understanding of underlying mechanisms. Adiposity is a noted modifiable metabolic risk factor for stroke, and recent research suggests that it benefits neurological rehabilitation. During the early phase of experimental stroke, the lipidomic results showed that fat depots underwent pronounced lipolysis and released fatty acids (FAs) that feed into consequent hepatic FA oxidation and ketogenesis. Systemic supplementation with the predominant ketone beta-hydroxybutyrate (BHB) is found to exert discernible effects on preserving blood-brain barrier (BBB) integrity and facilitating neuroinflammation resolution. Meanwhile, blocking FAO-ketogenesis processes by administration of CPT1α antagonist or shRNA targeting HMGCS2 exacerbated endothelial damage and aggravated stroke severity, whereas BHB supplementation blunted these injuries. Mechanistically, it is unveiled that BHB infusion is taken up by monocarboxylic acid transporter 1 (MCT1) specifically expressed in cerebral endothelium and upregulated the expression of tight junction protein ZO-1 by enhancing local ß-hydroxybutyrylation of H3K9 at the promoter of TJP1 gene. Conclusively, an adaptive metabolic mechanism is elucidated by which acute lipolysis stimulates FAO-ketogenesis processes to restore BBB integrity after stroke. Ketogenesis functions as an early metabolic responder to restrain stroke progression, providing novel prospectives for clinical translation.

Nestin promotes pulmonary fibrosis via facilitating recycling of TGF-ß receptor I.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease that is characterised by aberrant proliferation of activated myofibroblasts and pathological remodelling of the extracellular matrix. Previous studies have revealed that the intermediate filament protein nestin plays key roles in tissue regeneration and wound healing in different organs. Whether nestin plays a critical role in the pathogenesis of IPF needs to be clarified. METHODS: Nestin expression in lung tissues from bleomycin-treated mice and IPF patients was determined. Transfection with nestin short hairpin RNA vectors in vitro that regulated transcription growth factor (TGF)-ß/Smad signalling was conducted. Biotinylation assays to observe plasma membrane TßRI, TßRI endocytosis and TßRI recycling after nestin knockdown were performed. Adeno-associated virus serotype (AAV)6-mediated nestin knockdown was assessed in vivo. RESULTS: We found that nestin expression was increased in a murine pulmonary fibrosis model and IPF patients, and that the upregulated protein primarily localised in lung α-smooth muscle actin-positive myofibroblasts. Mechanistically, we determined that nestin knockdown inhibited TGF-ß signalling by suppressing recycling of TßRI to the cell surface and that Rab11 was required for the ability of nestin to promote TßRI recycling. In vivo, we found that intratracheal administration of AAV6-mediated nestin knockdown significantly alleviated pulmonary fibrosis in multiple experimental mice models. CONCLUSION: Our findings reveal a pro-fibrotic function of nestin partially through facilitating Rab11-dependent recycling of TßRI and shed new light on pulmonary fibrosis treatment.

Correction: Bis(ethylmaltolato)oxidovanadium(iv) inhibited the pathogenesis of Alzheimer's disease in triple transgenic model mice.

Correction for 'Bis(ethylmaltolato)oxidovanadium(iv) inhibited the pathogenesis of Alzheimer's disease in triple transgenic model mice' by Zhijun He et al., Metallomics, 2020, DOI: 10.1039/c9mt00271e.

Bis(ethylmaltolato)oxidovanadium(iv) inhibited the pathogenesis of Alzheimer's disease in triple transgenic model mice.

Vanadium compounds have been reported to mimic the anti-diabetes effects of insulin on rodent models, but their effects on Alzheimer's disease (AD) have rarely been explored. In this paper, 9-month-old triple transgenic AD model mice (3×Tg-AD) received bis(ethylmaltolato)oxidovanadium(iv) (BEOV) at doses of 0.2 mmol L-1 (68.4 µg mL-1) and 1.0 mmol L-1 (342 µg mL-1) for 3 months. BEOV at both doses was found to improve contextual memory and spatial learning in AD mice. It also improved glucose metabolism and protected neuronal synapses in the AD brain, as evidenced respectively by 18F-labeled fluoro-deoxyglucose positron emission tomography (18F-FDG-PET) scanning and by transmission electron microscopy. Inhibitory effects of BEOV on ß-amyloid (Aß) plaques and neuronal impairment in the cortex and hippocampus of fluorescent AD mice were visualized three-dimensionally by applying optical clearing technology to brain slices before confocal laser scanning microscopy. Western blot analysis semi-quantitatively revealed the altered levels of Aß42 in the brains of wildtype, AD, and AD treated with 0.2 and 1.0 mmol L-1 BEOV mice (70.3%, 100%, 83.2% and 56.8% in the hippocampus; 82.4%, 100%, 66.9% and 42% in the cortex, respectively). The mechanism study showed that BEOV increased the expression of peroxisome proliferator-activated receptor γ (PPARγ) (140%, 100%, 142% and 160% in the hippocampus; 167%, 100%, 124% and 133% in the cortex) to inactivate the JAK2/STAT3/SOCS-1 pathway and to block the amyloidogenesis cascade, thus attenuating Aß-induced insulin resistance in AD models. BEOV also reduced protein tyrosine phosphatase 1B (PTP1B) expression (74.8%, 100%, 76.5% and 53.8% in the hippocampus; 71.8%, 100%, 94.2% and 81.8% in cortex) to promote insulin sensitivity and to stimulate the PI3K/Akt/GSK3ß pathway, subsequently reducing tau hyperphosphorylation (phosphorylated tau396 levels were 51.1%, 100%, 56.1% and 50.2% in the hippocampus; 22.2%, 100%, 36.1%, and 24% in the cortex). Our results suggested that BEOV reduced the pathological hallmarks of AD by targeting the pathways of PPARγ and PTP1B in 3×Tg AD mice.

Nestin regulates cellular redox homeostasis in lung cancer through the Keap1-Nrf2 feedback loop.

Abnormal cancer antioxidant capacity is considered as a potential mechanism of tumor malignancy. Modulation of oxidative stress status is emerging as an anti-cancer treatment. Our previous studies have found that Nestin-knockdown cells were more sensitive to oxidative stress in non-small cell lung cancer (NSCLC). However, the molecular mechanism by which Nestin protects cells from oxidative damage remains unclear. Here, we identify a feedback loop between Nestin and Nrf2 maintaining the redox homeostasis. Mechanistically, the ESGE motif of Nestin interacts with the Kelch domain of Keap1 and competes with Nrf2 for Keap1 binding, leading to Nrf2 escaping from Keap1-mediated degradation, subsequently promoting antioxidant enzyme generation. Interestingly, we also map that the antioxidant response elements (AREs) in the Nestin promoter are responsible for its induction via Nrf2. Taken together, our results indicate that the Nestin-Keap1-Nrf2 axis regulates cellular redox homeostasis and confers oxidative stress resistance in NSCLC.

Benzo(a)pyrene degradation by cytochrome P450 hydroxylase and the functional metabolism network of Bacillus thuringiensis.

The relationship between benzo(a)pyrene biodegradation and certain target biomolecules has been investigated. To regulate the degradation process, the associated metabolism network must be clarified. To this end, benzo(a)pyrene degradation, carbon substrate metabolism and exometabolomic mechanism of Bacillus thuringiensis were analyzed. Benzo(a)pyrene was degraded through hydroxylation catalyzed by cytochrome P450 hydroxylase. After the treatment of 0.5 mg L-1 of benzo(a)pyrene by 0.2 g L-1 of cells for 9 d, biosorption and degradation efficiencies were measured at approximately 90% and 80%, respectively. During this process, phospholipid synthesis, glycogen, asparagine, arginine, itaconate and xylose metabolism were significantly downregulated, while glycolysis, pentose phosphate pathway, citrate cycle, amino sugar and nucleotide sugar metabolism were significantly upregulated. These findings offer insight into the biotransformation regulation of polycyclic aromatic hydrocarbons.

Nuclear Nestin deficiency drives tumor senescence via lamin A/C-dependent nuclear deformation.

Emerging evidence has revealed that Nestin not only serves as a biomarker for multipotent stem cells, but also regulates cell proliferation and invasion in various tumors. However, the mechanistic contributions of Nestin to cancer pathogenesis are still unknown. In the present study, previously thought to reside exclusively in the cytoplasm, Nestin can also be found in the nucleus and participate in protecting tumor cells against cellular senescence. Specifically, we reveal that Nestin has a nuclear localization signal (aa318-aa347) at the downstream of rod domain. We then find nuclear Nestin could interact with lamin A/C. Mechanistic investigations demonstrate that Nestin depletion results in the activation of cyclin-dependent kinase 5 (Cdk5), which causes the phosphorylation of lamin A/C (mainly at S392 site) and its subsequent translocation to the cytoplasm for degradation. The findings establish a role for nuclear Nestin in tumor senescence, which involves its nucleus-localized form and interaction with lamin A/C.

Cellular metabolism network of Bacillus thuringiensis related to erythromycin stress and degradation.

Erythromycin is one of the most widely used macrolide antibiotics. To present a system-level understanding of erythromycin stress and degradation, proteome, phospholipids and membrane potentials were investigated after the erythromycin degradation. Bacillus thuringiensis could effectively remove 77% and degrade 53% of 1 µM erythromycin within 24 h. The 36 up-regulated and 22 down-regulated proteins were mainly involved in spore germination, chaperone and nucleic acid binding. Up-regulated ribose-phosphate pyrophosphokinase and ribosomal proteins confirmed that the synthesis of protein, DNA and RNA were enhanced after the erythromycin degradation. The reaction network of glycolysis/gluconeogenesis was activated, whereas, the activity of spore germination was decreased. The increased synthesis of phospholipids, especially, palmitoleic acid and oleic acid, altered the membrane permeability for erythromycin transport. Ribose-phosphate pyrophosphokinase and palmitoleic acid could be biomarkers to reflect erythromycin exposure. Lipids, disease, pyruvate metabolism and citrate cycle in human cells could be the target pathways influenced by erythromycin. The findings presented novel insights to the interaction among erythromycin stress, protein interaction and metabolism network, and provided a useful protocol for investigating cellular metabolism responses under pollutant stress.

Metabolic and proteomic mechanism of bisphenol A degradation by Bacillus thuringiensis.

Bisphenol A (BPA) is a worldwide, widespread pollutant with estrogen mimicking and hormone-like properties. To date, some target biomolecules associated with BPA toxicity have been confirmed. The limited information has not clarified the related metabolism at the pathway and network levels. To this end, metabolic and proteomic approaches were performed to reveal the synthesis of phospholipids and proteins and the metabolic network during the BPA degradation process. The results showed that the degradation efficiency of 1 µM of BPA by 1 g L-1 of Bacillus thuringiensis was up to 85% after 24 h. During this process, BPA significantly changed the membrane permeability; altered sporulation, amino acid and protein expression, and carbon, purine, pyrimidine and fatty acid metabolism; enhanced C14:0, C16:1ω7, C18:2ω6, C18:1ω9t and C18:0 synthesis; and increased the trans/cis ratio of C18:1ω9t/C18:1ω9c. It also depressed the spore DNA stability of B. thuringiensis. Among the 14 upregulated and 7 down-regulated proteins, SasP-1 could be a biomarker to reflect BPA-triggered spore DNA impairment. TpiA, RpoA, GlnA and InfA could be phosphorylated at the active sites of serine and tyrosine. The findings presented novel insights into the interaction among BPA stress, BPA degradation, phospholipid synthesis and protein expression at the network and phylogenetic levels.

Targeted homing of CCR2-overexpressing mesenchymal stromal cells to ischemic brain enhances post-stroke recovery partially through PRDX4-mediated blood-brain barrier preservation.

Rationale: Mesenchymal stromal cells (MSCs) are emerging as a novel therapeutic strategy for the acute ischemic stroke (AIS). However, the poor targeted migration and low engraftment in ischemic lesions restrict their treatment efficacy. The ischemic brain lesions express a specific chemokine profile, while cultured MSCs lack the set of corresponding receptors. Thus, we hypothesize that overexpression of certain chemokine receptor might help in MSCs homing and improve therapeutic efficacy. Methods: Using the middle cerebral artery occlusion (MCAO) model of ischemic stroke, we identified that CCL2 is one of the most highly expressed chemokines in the ipsilateral hemisphere. Then, we genetically transduced the corresponding receptor, CCR2 to the MSCs and quantified the cell retention of MSCCCR2 compared to the MSCdtomato control. Results: MSCCCR2 exhibited significantly enhanced migration to the ischemic lesions and improved the neurological outcomes. Brain edema and blood-brain barrier (BBB) leakage levels were also found to be much lower in the MSCCCR2-treated rats than the MSCdtomato group. Moreover, this BBB protection led to reduced inflammation infiltration and reactive oxygen species (ROS) generation. Similar results were also confirmed using the in vitro BBB model. Furthermore, genome-wide RNA sequencing (RNA-seq) analysis revealed that peroxiredoxin4 (PRDX4) was highly expressed in MSCs, which mainly contributed to their antioxidant impacts on MCAO rats and oxygen-glucose deprivation (OGD)-treated endothelium. Conclusion: Taken together, this study suggests that overexpression of CCR2 on MSCs enhances their targeted migration to the ischemic hemisphere and improves the therapeutic outcomes, which is attributed to the PRDX4-mediated BBB preservation.

Influences of laser source on phase-sensitivity optical time-domain reflectometer-based distributed intrusion sensor.

This paper investigates the influences of laser source on distributed intrusion sensor based on a phase-sensitivity optical time-domain reflectometer (φ-OTDR). A numerical simulation is performed to illustrate the relationships between trace-to-trace fluctuations and frequency drift rate as well as pulse width, and fluctuations ratio coefficient (FRC) is proposed to evaluate the level of trace-to-trace fluctuations. The simulation results show that the FRC grows with increasing frequency drift rate and pulse width, reaches, and maintains the peak value when the frequency drift rate and/or the pulse width are high enough. Furthermore, experiments are implemented using a φ-OTDR prototype with a low frequency drift laser (<5 MHz/min), of which the high frequency drift rate is simulated by frequency sweeping. The good agreement of experimental with simulated results in the region of high frequency drift rate validates the theoretical analysis, and the huge differences between them in the region of low frequency drift rate indicate the place of laser frequency drift among system noises. The conclusion is useful for choosing laser sources and improving the performance of φ-OTDR.

Hepatic histopathology and postoperative outcome after preoperative chemotherapy for Chinese patients with colorectal liver metastases.

AIM: To assess the effects of preoperative treatment on the hepatic histology of non-tumoral liver and the postoperative outcome. METHODS: One hundred and six patients underwent hepatic resection for colorectal metastases between 1999 and 2009. The surgical specimens were reviewed with established criteria for diagnosis and grading of pathological hepatic injury. The impact of preoperative therapy on liver injury and postoperative outcome was analyzed. RESULTS: Fifty-three patients (50%) received surgery alone, whereas 42 patients (39.6%) received neoadjuvant chemotherapy and 11 (10.4%) patients received preoperative hepatic artery infusion (HAI). Chemotherapy included oxaliplatin-based regimens (31.1%) and irinotecan-based regimens (8.5%). On histopathological analysis, 16 patients (15.1%) had steatosis, 31 (29.2%) had sinusoidal dilation and 20 patients (18.9%) had steatohepatitis. Preoperative oxaliplatin was associated with sinusoidal dilation compared with surgery alone (42.4% vs 20.8%, P = 0.03); however, the perioperative complication rate was not significantly different between the oxaliplatin group and surgery group (27.3% vs 13.2%, P = 0.1). HAI was associated with more steatosis, sinusoidal dilation and steatohepatitis than the surgery group, with higher perioperative morbidity (36.4% vs 13.2%, P = 0.06) and mortality (9.1% vs 0% P = 0.02). CONCLUSION: Preoperative oxaliplatin was associated with sinusoidal dilation compared with surgery alone. However, the preoperative oxaliplatin had no significant impact on perioperative outcomes. HAI can cause pathological changes and tends to increase perioperative morbidity and mortality.

[A retrospective analysis: comparison of the clinical characteristics and prognosis in elderly and young patients with locally advanced or metastatic non-small cell lung cancer.].

OBJECTIVE: To investigate whether the clinical characteristics, treatment modalities and prognosis of elderly (>/= 70 years) patients with advanced non-small cell lung cancer (NSCLC) differed from those of young (

Antitumor effect of Gefitinib, an epidermal growth factor receptor tyrosine kinase inhibitor, combined with cytotoxic agent on murine hepatocellular carcinoma.

AIM: To investigate the inhibitory effect of gefitinib combined with cytotoxic agent cisplatin (CDDP) on hepatocellular carcinoma (HCC). METHODS: Female Kunming mice and H22 hepatocarcinoma cells were used. Gefitinib at daily dose of 100 mg/kg body weight (BW) or lecithin liquid was given by gastrogavage once a day for 5 or 10 successive days. CDDP or normal saline (NS) was administered intraperitoneally (i.p.) once a day for 5 successive days. Mice were randomly divided into control group (lecithin, or NS, i.p.), CDDP group (daily dose, 1.2 mg/kg BW; d1-5, or d6-10), Gefitinib (d1-5, or d6-10, or d1-10), and Gefitinib combined with CDDP groups. The inhibitory rate (IR) of tumor, net BW, spleen index (SI), thymus index (TI) and the amount of peripheral blood cells of mice were detected on the 12th experiment day. RESULTS: The growth of HCC in mice was inhibited by Gefitinib alone (IR: 41% in d1-10 group and 30% in d1-5 group, respectively) or CDDP alone (IR: 32-54% in d1-5 group or d6-10 group). The highest inhibitory effect (IR: 56%) on HCC growth was observed in Gefitinib (d1-10) combined with CDDP (d1-5) group. Higher inhibition was also observed in CDDP (d1-5) followed by Gefitinib (d6-10) group than that in Gefitinib (d1-5) followed by CDDP (d6-10) group (IR: 61% vs 36%, P < 0.01) in the independent study. Net BW, SI, TI and the amount of blood cells of mice in Gefitinib alone group were not significantly different from those in control groups. CONCLUSION: Gefitinib can significantly inhibit the growth of murine H22 hepatocellular carcinoma. If Gefitinib is used after CDDP treatment in animal experiments, the inhibitory effect could be enhanced.