Trimethoxyflavanone relieves Paclitaxel-induced neuropathic pain via inhibiting expression and activation of P2X7 and production of CGRP in mice.

Paclitaxel (PTX) is an anticancer drug used to treat solid tumors, but one of its common adverse effects is chemotherapy-induced peripheral neuropathy (CIPN). Currently, there is limited understanding of neuropathic pain associated with CIPN and effective treatment strategies are inadequate. Previous studies report the analgesic actions of Naringenin, a dihydroflavonoid compound, in pain. Here we observed that the anti-nociceptive action of a Naringenin derivative, Trimethoxyflavanone (Y3), was superior to Naringenin in PTX-induced pain (PIP). An intrathecal injection of Y3 (1 µg) reversed the mechanical and thermal thresholds of PIP and suppressed the PTX-induced hyper-excitability of dorsal root ganglion (DRG) neurons. PTX enhanced the expression of ionotropic purinergic receptor P2X7 (P2X7) in satellite glial cells (SGCs) and neurons in DRGs. The molecular docking simulation predicts possible interactions between Y3 and P2X7. Y3 reduced the PTX-enhanced P2X7 expression in DRGs. Electrophysiological recordings revealed that Y3 directly inhibited P2X7-mediated currents in DRG neurons of PTX-treated mice, suggesting that Y3 suppressed both expression and function of P2X7 in DRGs post-PTX administration. Y3 also reduced the production of calcitonin gene-related peptide (CGRP) in DRGs and at the spinal dorsal horn. Additionally, Y3 suppressed the PTX-enhanced infiltration of Iba1-positive macrophage-like cells in DRGs and overactivation of spinal astrocytes and microglia. Therefore, our results indicate that Y3 attenuates PIP via inhibiting P2X7 function, CGRP production, DRG neuron sensitization, and abnormal spinal glial activation. Our study implies that Y3 could be a promising drug candidate against CIPN-associated pain and neurotoxicity.

R2R3 MYB transcription factor SbMYBHv33 negatively regulates sorghum biomass accumulation and salt tolerance.

KEY MESSAGE: SbMYBHv33 negatively regulated biomass accumulation and salt tolerance in sorghum and Arabidopsis by regulating reactive oxygen species accumulation and ion levels. Salt stress is one of the main types of environmental stress leading to a reduction in crop yield worldwide. Plants have also evolved a variety of corresponding regulatory pathways to resist environmental stress damage. This study aimed to identify a SbMYBHv33 transcription factor that downregulates in salt, drought, and abscisic acid (ABA) in the salt-tolerant inbred line sorghum M-81E. The findings revealed that overexpression of SbMYBHv33 in sorghum significantly reduced sorghum biomass accumulation at the seedling stage and also salinity tolerance. Meanwhile, a heterologous transformation of Arabidopsis with SbMYBHv33 produced a similar phenotype. The loss of function of the Arabidopsis homolog of SbMYBHv33 resulted in longer roots and increased salt tolerance. Under normal conditions, SbMYBHV33 overexpression promoted the expression of ABA pathway genes in sorghum and inhibited growth. Under salt stress conditions, the gene expression of SbMYBHV33 decreased in the overexpressed lines, and the promotion of these genes in the ABA pathway was attenuated. This might be an important reason for the difference in growth and stress resistance between SbMYBHv33-overexpressed sorghum and ectopic expression Arabidopsis. Hence, SbMYBHv33 is an important component of sorghum growth and development and the regulation of salt stress response, and it could negatively regulate salt tolerance and biomass accumulation in sorghum.

MicroRNAs balance growth and salt stress responses in sweet sorghum.

Salt stress is one of the major causes of reduced crop production, limiting agricultural development globally. Plants have evolved with complex systems to maintain the balance between growth and stress responses, where signaling pathways such as hormone signaling play key roles. Recent studies revealed that hormones are modulated by microRNAs (miRNAs). Previously, two sweet sorghum (Sorghum bicolor) inbred lines with different salt tolerance were identified: the salt-tolerant M-81E and the salt-sensitive Roma. The levels of endogenous hormones in M-81E and Roma varied differently under salt stress, showing a different balance between growth and stress responses. miRNA and degradome sequencing showed that the expression of many upstream transcription factors regulating signal transduction and hormone-responsive genes was directly induced by differentially expressed miRNAs, whose levels were very different between the two sweet sorghum lines. Furthermore, the effects of representative miRNAs on salt tolerance in sorghum were verified through a transformation system mediated by Agrobacterium rhizogenes. Also, miR-6225-5p reduced the level of Ca2+ in the miR-6225-5p-overexpressing line by inhibiting the expression of the Ca2+ uptake gene SbGLR3.1 in the root epidermis and affected salt tolerance in sorghum. This study provides evidence for miRNA-mediated growth and stress responses in sweet sorghum.

Identification and Transcriptome Analysis of Genes Related to Membrane Lipid Regulation in Sweet Sorghum under Salt Stress.

Sweet sorghum has strong stress resistance and is considered a promising energy crop. In the present study, the effects of salt on the membrane lipid metabolism of two sweet sorghum inbred lines (salt-tolerant M-81E and salt-sensitive Roma) were analyzed. After treatment with 150 mM NaCl, higher levels of fresh weight and chlorophyll fluorescence, as well as lower levels of malondialdehyde (MDA) were found in salt-tolerant M-81E. Concomitantly, 702 and 1339 differentially expression genes (DEGs) in M-81E and Roma were identified in response to salt stress. We determined that most DEGs were related to glycerophospholipid metabolism, glycerolipid metabolism, and other membrane lipid metabolisms. Under NaCl treatment, the expression of the membrane-associated phospholipase A1 was down-regulated at the transcriptional level, along with an increased content of phosphatidylcholine (PC) in both cultivars. The inhibition of triacylglycerol (TAG) mobilization in M-81E delayed salt-induced leaf senescence. Furthermore, enhanced levels of glycerol-3-phosphate acyltransferase (GPAT) expression contributed to improved salt resistance in M-81E. The results of this study demonstrate membrane the role of lipid regulation in mediating salt-defensive responses in sweet sorghum and expand our understanding of the relationship between changes in membrane lipid content and salt resistance.

Biological Functions of Strigolactones and Their Crosstalk With Other Phytohormones.

Phytohormones are small chemicals critical for plant development and adaptation to a changing environment. Strigolactones (SLs), carotenoid-derived small signalling molecules and a class of phytohormones, regulate multiple developmental processes and respond to diverse environmental signals. SLs also coordinate adjustments in the balance of resource distribution by strategic modification of the plant development, allowing plants to adapt to nutrient deficiency. Instead of operating independently, SL interplays with abscisic acid, cytokinin, auxin, ethylene, and some other plant phytohormones, forming elaborate signalling networks. Hormone signalling crosstalk in plant development and environmental response may occur in a fully concerted manner or as a cascade of sequential events. In many cases, the exact underlying mechanism is unclear because of the different effects of phytohormones and the varying backgrounds of their actions. In this review, we systematically summarise the synthesis, signal transduction, and biological functions of SLs and further highlight the significance of crosstalk between SLs and other phytohormones during plant development and resistance to ever-changing environments.

The contribution of neuro-immune crosstalk to pain in the peripheral nervous system and the spinal cord.

Pain is an unpleasant sensation associated with injury, inflammation, and infection. It has been demonstrated that communication between immune cells and neurons plays a vital role in pain and pain-related diseases (e.g. multiple sclerosis, osteoarthritis, irritable bowel syndrome). Growing data from preclinical and clinical studies have established that the bilateral regulations between peripheral immune cells and nociceptive neurons could be beneficial or detrimental for the development of pain and immune defense. We here review the mechanisms underlying neuroimmune crosstalk between circulating immune cells (e.g. macrophages, T cells, mast cells, neutrophils, monocytes) and nociceptors in the peripheral nervous system and the spinal cord. Deciphering the mechanisms by which neuroimmune interaction integrates neuronal inputs and immune responses helps to understand the pathogenesis of pain-related diseases and develop effective medications.

Effects of Baduanjin on glucose and lipid metabolism in diabetic patients: A protocol for systematic review and meta-analysis.

BACKGROUND: Baduanjin is an ancient technique of physical and breathing exercises (Dao Yin). This technique is divided into eight sections and each section is a motion, so it is called "Baduanjin". It is practice without equipment, simple and easy to learn, whose effect is significant leading to good fitness effect. Diabetes mellitus is a chronic metabolic disease. Clinical studies have reported that Baduanjin can affect the metabolism of blood glucose and blood lipid in diabetic patients, but the reported efficacy is different among different studies. Therefore, the study is aimed to systematically evaluate the size and differences of the impact of Baduanjin on the metabolism of glucose and lipid in diabetic patients. METHODS: Retrieved randomized controlled trials(RCTs) on effects of Baduanjin on glucose and lipid metabolism in diabetic patients from PubMed, Web of Science, the Cochrane Library, Embase, CNKI with computer while mutually retrieved the same things from Chinese Clinical Trial Registry(ChiCTR), Google Academic and Baidu Academic. The retrieval time was from their establishment to October 2020. Then 2 researchers independently extracted relevant data and evaluated the quality of the included literatures, and meta-analysis was conducted on the included literatures using RevMan5.3. RESULTS: This research used outcome indicators like fasting blood glucose, postprandial blood glucose, glycosylated hemoglobin, total cholesterol content and triglyceride content to explore the effect of Baduanjin on glucose and lipid metabolism in diabetic patients specifically. CONCLUSION: The research will provide reliable evidence-based proof for Baduanjin improving glucose and lipid metabolism of diabetic patients. ETHICS AND DISSEMINATION: Private information from individuals will not be published. This systematic review also does not involve endangering participant rights. Ethical approval was not required. The results may be published in a peer-reviewed journal or disseminated at relevant conferences. OSF REGISTRATION NUMBER: DOI 10.17605/ OSF.IO/AGJHQ.

Role of pericyte-derived SENP1 in neuronal injury after brain ischemia.

AIMS: SUMOylation is a posttranslational modification related to multiple human diseases. SUMOylation can be reversed by classes of proteases known as the sentrin/SUMO-specific proteases (SENPs). In the present study, we investigate the potential role of SENP1 in pericytes in the brain ischemia. METHODS: Pericyte-specific deletion of senp1 mice (Cspg4-Cre; senp1f/f ) were used for brain function and neuronal damage evaluation following brain ischemia. The cerebral blood vessels of diameter, velocity, and flux were performed in living mice by two-photon laser scanning microscopy (TPLSM). Biochemical analysis and immunohistochemistry methods were used to address the role and mechanism of pericyte-specific SENP1 in the pathological process of brain ischemia. A coculture model of HBVPs and HBMECs mimicked the BBB in vitro and was used to evaluate BBB integrity after glucose deprivation. RESULTS: Our results showed that senp1-specific deletion in pericytes did not affect the motor function and cognitive function of mice. However, the pericyte-specific deletion of senp1 aggravated the infarct size and motor deficit following focal brain ischemia. Consistently, the TPLSM data demonstrated that SENP1 deletion in pericytes accelerated thrombosis formation in brain microvessels. We also found that pericyte-specific deletion of senp1 exaggerated the neuronal damage significantly following brain ischemia in mice. Moreover, SENP1 knockdown in pericytes could activate the apoptosis signaling and disrupt the barrier integrity in vitro coculture model. CONCLUSIONS: Our findings revealed that targeting SENP1 in pericytes may represent a novel therapeutic strategy for neurovascular protection in stroke.

Effect of low-dose Levamlodipine Besylate in the treatment of vascular dementia.

Vascular dementia (VaD) is a complex disorder caused by reduced blood flow in the brain. However, there is no effective pharmacological treatment option available until now. Here, we reported that low-dose levamlodipine besylate could reverse the cognitive impairment in VaD mice model of right unilateral common carotid arteries occlusion (rUCCAO). Oral administration of levamlodipine besylate (0.1 mg/kg) could reduce the latency to find the hidden platform in the MWM test as compared to the vehicle group. Furthermore, vehicle-treated mice revealed reduced phospho-CaMKII (Thr286) levels in the hippocampus, which can be partially restored by levamlodipine besylate (0.1 mg/kg and 0.5 mg/kg) treatment. No significant outcome on microglia and astrocytes were observed following levamlodipine besylate treatment. This data reveal novel findings of the therapeutic potential of low-dose levamlodipine besylate that could considerably enhance the cognitive function in VaD mice.

Visualizing Autophagic Flux during Endothelial Injury with a Pathway-Inspired Tandem-Reaction Based Fluorogenic Probe.

Autophagy is a dynamic and complicated catabolic process. Imaging autophagic flux can clearly advance knowledge of its pathophysiology significance. While the most common way autophagy is imaged relies on fluorescent protein-based probes, this method requires substantial genetic manipulation that severely restricts the application. Small fluorescent probes capable of tracking autophagic flux with good spatiotemporal resolution are highly demanable. Methods: In this study, we developed a small-molecule fluorogenic probe (AFG-1) that facilitates real-time imaging of autophagic flux in both intact cells and live mice. AFG-1 is inspired by the cascading nitrosative and acidic microenvironments evolving during autophagy. It operates over two sequential steps. In the first step, AFG-1 responds to the up-regulated peroxynitrite at the initiation of autophagy by its diphenylamino group being oxidatively dearylated to yield a daughter probe. In the second step, the daughter probe responds to the acidic autolysosomes at the late stage of autophagy by being protonated. Results: This pathway-dependent mechanism has been confirmed first by sequentially sensing ONOO- and acid in aqueous solution, and then by imaging autophagic flux in live cells. Furthermore, AFG-1 has been successfully applied to visualize autophagic flux in real-time in live mice following brain ischemic injury, justifying its robustness. Conclusion: Due to the specificity, easy operation, and the dynamic information yielded, AFG-1 should serve as a potential tool to explore the roles of autophagy under various pathological settings.

The emerging role of microRNA-4487/6845-3p in Alzheimer's disease pathologies is induced by Aß25-35 triggered in SH-SY5Y cell.

BACKGROUND: Accumulation of amyloid ß-peptide (Aß) is implicated in the pathogenesis and development of Alzheimer's disease (AD). Neuron-enriched miRNA was aberrantly regulated and may be associated with the pathogenesis of AD. However, regarding whether miRNA is involved in the accumulation of Aß in AD, the underlying molecule mechanism remains unclear. Therefore, we conduct a systematic identification of the promising role of miRNAs in Aß deposition, and shed light on the molecular mechanism of target miRNAs underlying SH-SY5Y cells treated with Aß-induced cytotoxicity. RESULTS: Statistical analyses of microarray data revealed that 155 significantly upregulated and 50 significantly downregulated miRNAs were found on the basis of log2 | Fold Change | ≥ 0.585 and P < 0.05 filter condition through 2588 kinds of mature miRNA probe examined. PCR results show that the expression change trend of the selected six miRNAs (miR-6845-3p, miR-4487, miR-4534, miR-3622-3p, miR-1233-3p, miR-6760-5p) was consistent with the results of the gene chip. Notably, Aß25-35 downregulated hsa-miR-4487 and upregulated hsa-miR-6845-3p in SH-SY5Y cell lines associated with Aß-mediated pathophysiology. Increase of hsa-miR-4487 could inhibit cells apoptosis, and diminution of hsa-miR-6845-3p could attenuate axon damage mediated by Aß25-35 in SH-SY5Y. CONCLUSIONS: Together, these findings suggest that dysregulation of hsa-miR-4487 and hsa-miR-6845-3p contributed to the pathogenesis of AD associated with Aß25-35 mediated by triggering cell apoptosis and synaptic dysfunction. It might be beneficial to understand the pathogenesis and development of clinical diagnosis and treatment of AD. Further, our well-designed validation studies will test the miRNAs signature as a prognostication tool associated with clinical outcomes in AD.

Novel multimodal analgesia regimen improves post-TACE pain in patients with hepatocellular carcinoma.

BACKGROUD: Transarterial chemoembolization (TACE) is the primary palliative treatment for patients with unresectable hepatocellular carcinoma (HCC). However, it is often accompanied by postoperative pain which hinder patient recovery. This study was to examine whether preemptive parecoxib and sufentanil-based patient controlled analgesia (PCA) could improve the pain management in patients receiving TACE for inoperable HCC. METHODS: From June to December 2016, 84 HCC patients undergoing TACE procedure were enrolled. Because of the willingness of the individuals, it is difficult to randomize the patients to different groups. We matched the patients' age, gender and pain scores, and divided the patients into the multimodal group (n = 42) and control group (n = 42). Patients in the multimodal group received 40 mg of parecoxib, 30 min before TACE, followed by 48 h of sufentanil-based PCA. Patients in the control group received a routine analgesic regimen, i.e., 5 mg of dezocine during operation, and 100 mg of tramadol or equivalent intravenous opioid according to patient's complaints and pain intensity. Postoperative pain intensity, percentage of patients as per the pain category, adverse reaction, duration of hospital stay, cost-effectiveness, and patient's satisfaction were all taken into consideration when evaluated. RESULTS: Compared to the control group, the visual analogue scale scores for pain intensity was significantly lower at 2, 4, 6, and 12 h (all P < 0.05) in the multimodal group and a noticeably lower prevalence of post-operative nausea and vomiting in the multimodal group (31.0% vs. 59.5%). Patient's satisfaction in the multimodal group was also significantly higher than that in the control group (95.2% vs. 69.0%). No significant difference was observed in the duration of hospital stay between the two groups. CONCLUSION: Preemptive parecoxib and sufentanil-based multimodal analgesia regime is a safe, efficient and cost-effective regimen for postoperative pain control in HCC patients undergoing TACE.

Cholinergic Grb2-Associated-Binding Protein 1 Regulates Cognitive Function.

Grb2-associated-binding protein 1 (Gab1) is a docking/scaffolding molecule known to play an important role in cell growth and survival. Here, we report that Gab1 is decreased in cholinergic neurons in Alzheimer's disease (AD) patients and in a mouse model of AD. In mice, selective ablation of Gab1 in cholinergic neurons in the medial septum impaired learning and memory and hippocampal long-term potentiation. Gab1 ablation also inhibited SK channels, leading to an increase in firing in septal cholinergic neurons. Gab1 overexpression, on the other hand, improved cognitive function and restored hippocampal CaMKII autorphosphorylation in AD mice. These results suggest that Gab1 plays an important role in the pathophysiology of AD and may represent a novel therapeutic target for diseases involving cholinergic dysfunction.

Melatonin ameliorates hypoglycemic stress-induced brain endothelial tight junction injury by inhibiting protein nitration of TP53-induced glycolysis and apoptosis regulator.

Severe hypoglycemia has a detrimental impact on the cerebrovasculature, but the molecular events that lead to the disruption of the integrity of the tight junctions remain unclear. Here, we report that the microvessel integrity was dramatically compromised (59.41% of wild-type mice) in TP53-induced glycolysis and apoptosis regulator (TIGAR) transgenic mice stressed by hypoglycemia. Melatonin, a potent antioxidant, protects against hypoglycemic stress-induced brain endothelial tight junction injury in the dosage of 400 nmol/L in vitro. FRET (fluorescence resonance energy transfer) imaging data of endothelial cells stressed by low glucose revealed that TIGAR couples with calmodulin to promote TIGAR tyrosine nitration. A tyrosine 92 mutation interferes with the TIGAR-dependent NADPH generation (55.60% decreased) and abolishes its protective effect on tight junctions in human brain microvascular endothelial cells. We further demonstrate that the low-glucose-induced disruption of occludin and Caludin5 as well as activation of autophagy was abrogated by melatonin-mediated blockade of nitrosative stress in vitro. Collectively, we provide information on the detailed molecular mechanisms for the protective actions of melatonin on brain endothelial tight junctions and suggest that this indole has translational potential for severe hypoglycemia-induced neurovascular damage.

Calmodulin inhibitor ameliorates cognitive dysfunction via inhibiting nitrosative stress and NLRP3 signaling in mice with bilateral carotid artery stenosis.

AIMS: Vascular dementia (VaD) is a heterogeneous brain disorder for which there are no effective approved pharmacological treatments available. We aimed to evaluate the effect of calmodulin inhibitor, DY-9836, and its loaded nanodrug carrier system on cognitive impairment and gain a better understanding of the protective mechanisms in mice with bilateral carotid artery stenosis (BCAS). RESULTS: DY-9836 (0.5 or 1 mg/kg) or DY-9836 (0.25 mg/kg)-encapsulated polysialic acid-octadecylamine (PSA-ODA) micelles (PSA-ODA/DY) were given to BCAS mice for 4 weeks. Administration of DY-9836 or PSA-ODA/DY reduced escape latency in space exploration and working memory test compared with vehicle group. Vehicle-treated mice showed reduced phospho-CaMKII (Thr286/287) levels in the hippocampus, whereas partially restored by DY-9836 (1 mg/kg) or PSA-ODA/DY (0.25 mg/kg) treatment. In accordance with the pharmacological profile of DY-9836 observed during behavioral studies, experimental molecular and biochemical markers induced by BCAS, such as protein tyrosine nitration, Nod-like receptor protein 3 (NLRP3), caspase-1, and interleukin-1ß, were reduced by DY-9836 and PSA-ODA/DY treatment. CONCLUSIONS: These data disclose novel findings about the therapeutic potential of DY-9836, and its encapsulated nanodrug delivery system significantly enhanced the cognitive function via inhibitory effect on nitrosative stress and NLRP3 signaling in VaD mice.

Nitration of TRPM2 as a Molecular Switch Induces Autophagy During Brain Pericyte Injury.

AIMS: Dysfunction of neurovascular pericytes underlies breakdown of the blood-brain barrier, but the molecular mechanisms are largely unknown. In this study, we evaluated the role of the transient receptor potential melastatin-related 2 (TRPM2) channel and autophagy during brain pericyte injury both in vitro and in vivo. RESULTS: A rapid induction in autophagy in human brain vascular pericytes, in the zinc oxide nanoparticles (ZnO-NP)-induced cell stress model, was paralleled with an increase in the expression of the TRPM2-S truncated isoform, which was abolished by treatment with a nitric oxide synthase inhibitor and a peroxynitrite scavenger. Furthermore, Y1485 in the C-terminus of the TRPM2 protein was identified as the tyrosine nitration substrate by mass spectrometry. Overexpression of the Y1485S TRPM2 mutant reduced LC3-II accumulation and pericyte injury induced by ZnO-NP. Consistently, LC3-II accumulation was reduced and pericytes were better preserved in intact brain microvessels of the TRPM2 knockout mice after ZnO-NP-induced vascular injury. Innovation and Conclusions: Our present study has revealed a novel mechanism of autophagy disturbance secondary to nitrosative stress-induced tyrosine nitration of TRPM2 during pericyte injury. Antioxid. Redox Signal. 27, 1297-1316.

Endogenous Polysialic Acid Based Micelles for Calmodulin Antagonist Delivery against Vascular Dementia.

Clinical treatment for vascular dementia still remains a challenge mainly due to the blood-brain barrier (BBB). Here, a micelle based on polysialic acid (PSA), which is a hydrophilic and endogenous carbohydrate polymer, was designed to deliver calmodulin antagonist for therapy of vascular dementia. PSA was first chemically conjugated with octadecylamine (ODA), and the obtained PSA-ODA copolymer could self-assemble into micelle in aqueous solution with a 120.0 µg/mL critical micelle concentration. The calmodulin antagonist loaded PSA-ODA micelle, featuring sustained drug release behavior over a period of 72 h with a 3.6% (w/w) drug content and a 107.0 ± 4.0 nm size was then fabricated. The PSA-ODA micelle could cross the BBB mainly via active endocytosis by brain endothelial cells followed by transcytosis. In a water maze test for spatial learning, calmodulin antagonist loaded PSA-ODA micelle significantly reduced the escape latencies of right unilateral common carotid arteries occlusion (rUCCAO) mice with dosage significantly reduced versus free drug. The decrease of hippocampal phospho-CaMKII (Thr286/287) and phospho-synapsin I (Ser603) was partially restored in rUCCAO mice following calmodulin antagonist loaded PSA-ODA micelle treatment. Consistent with the restored CaMKII phosphorylation, the elevation of BrdU/NeuN double-positive cells in the same context was also observed. Overall, the PSA-ODA micelle developed from the endogenous material might promote the development of therapeutic approaches for improving the efficacy of brain-targeted drug delivery and have great potential for vascular dementia treatment.

Calpain-Dependent ErbB4 Cleavage Is Involved in Brain Ischemia-Induced Neuronal Death.

Disturbance of neuregulin-1ß/ErbB4 signaling is considered to be associated with brain ischemia, but the mechanisms of this disruption are largely unknown. In the present study, we provide evidence that degradation of ErbB4 is involved in neuronal cell death in response to ischemia. Our data showed that the application of neuregulin-1ß provided significant protection against oxygen-glucose deprivation (OGD)-induced neuronal death as detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, annexin V/propidium iodide flow cytometry analysis and terminal deoxynucleotidyl transferase (TdT) dUTP nick end labeling (TUNEL) staining. Furthermore, neuregulin-1ß treatment significantly reduced the infarct volume of ischemic mice, and this result was not seen in the ErbB4 knockout mice. We found that brain ischemia induced the breakdown of ErbB4 in a time-dependent manner in vivo, but not that of ErbB2. In vitro studies further indicated that recombinant calpain induced the cleavage of ErbB4 in a dose-dependent way, whereas the calpain inhibitor significantly reduced the OGD-induced ErbB4 breakdown. Additionally, OGD-induced apoptosis was partially abolished by transfection with the ErbB4E872K mutant. Taken together, neuregulin-1ß elicits its neuroprotective effect in an ErbB4-dependent manner, and the cleavage of ErbB4 by calpain contributes to a neuronal cell death cascade during brain ischemia.

Enhanced chemiluminescence of cerium(IV)-Tween 85 system and the analytical application.

The oxidation reaction between cerium(IV) and Tween 85 in sulfuric acid medium produced weak chemiluminescence (CL). In this paper, it was found that citrate could strongly enhance the CL of cerium(IV)-Tween 85-polyphenol system. Based on studies of ultraviolet-visible spectra and CL spectra, the CL enhancement mechanism had been proposed. It was surmised that the light emission was from an excited oxygen molecular pair O2((1)Δg)O2((1)∑g(-)). The maximum emission wavelength was about 478 nm. The effects of 17 amino acids and 29 organic compounds on cerium(IV)-Tween 85-citrate CL were investigated by a flow injection procedure. This study showed the present system had a wide application for the determination of these compounds.