Developmental characteristics and response to iron toxicity of root border cells in rice seedlings

To investigate the Fe^2＋ effects on root tips in rice plant, experiments were carried out using border cells in vitro. The border cells were pre-planted in aeroponic culture and detached from root tips. Most border cells have a long elliptical shape. The number and the viability of border cells in situ reached the maxima of 1600 and 97.5%, respectively, at 20---25 mm root length. This mortality was more pronounced at the first 1-12 h exposure to 250 mg/L Fe^2＋ than at the last 12-36 h. After 36 h, the cell viability exposed to 250 mg/L Fe^2＋ decreased to nought, whereas it was 46.5% at 0 mg/L Fe^2＋. Increased Fe^2＋ dosage stimulated the death of detached border cells from rice cultivars. After 4 h Fe^2＋ treatment, the cell viabilities were _〉80% at 0 and 50 mg/L Fe^2＋ treatment and were 〈62% at 150, 250 and 350 mg/L Fe^2＋ treatment; The viability of border cells decreased by 10% when the Fe^2＋ concentration increased by 100 mg/L. After 24 h Fe^2＋ treatment, the viabilities of border cells at all the Fe^2＋ levels were 〈65%; The viability of border cells decreased by 20% when the Fee＋ concentration increased by 100 mg/L. The decreased viabilities of border cells indicated that Fe^2＋ dosage and treatment time would cause deadly effect on the border cells. The increased cell death could protect the root tips from toxic harm. Therefore, it may protect root from the damage caused by harmful iron toxicity.

Cell Toxicity Effect of Cadmium on Yeast Cells by Detecting NADH Autofluorescence

The cytotoxic effect of cadmium is studied by detecting intracellular nicotinamide adenine dinucleotidea（NADH） autofluorescence in this work. NADH autofluorescence in processes of cadmium-induced apoptosis, necrosis and reversible injury are recorded timely. The relativity between time course of NADH autofluorescence and cadmium toxicity is established. The cell toxicity effect of Cadmium on yeast cells is studied by detecting the time courses of intracellular reduced NADH autofluorescence in this work. The relativity between time courses of NADH autofluorescence and Cadmium toxicity is established.

α-Linolenic acid alleviates aluminium chloride-induced toxicity in PC12 cells by activation of PKA-CREB-BDNF signaling pathway

Aluminum has been associated with neurodegenerative diseases.ALA(α-linolenic acid),an essential dietary component for human health,possesses prominent biological activities.Herein,we aim to explore the neuroprotective effects of ALA on aluminum toxicity and reveal the underlying mechanism.Results show that aluminum chloride(denoted as Al)enabled cell viability decline and apoptosis with oxidative stress and mitochondrial damage in differentiated rat pheochromocytoma cells(PC12)for 24 h incubation.Compared with Al(10 mmol/L)treatment alone,ALA(50μmol/L)pretreatment for 24 h significantly enhanced cell viability by 28.40%,and hindered cell apoptosis by 12.35%,together with recovering redox state balance and alleviating mitochondrial damage.It was measured that ALA treatment upregulated Bcl-2 expression and down-regulated Bax level,accompanied with an expression decline of caspase-3 and caspase-9.Meanwhile,ALA pretreatment was proved to increase protein kinase A(PKA)expression and to promote phosphorylation of cAMP response element-binding protein(p-CREB),resulting in elevation on the level of brain-derived neurotrophic factor(BDNF).The above results showed that ALA attenuated Al toxicity in PC12 cells by mediating the PKA-CREBBDNF signaling pathway.

Protective effect of paeonol on beta-amyloid 25-35- induced toxicity in PC12 cells

BACKGROUND：Paeonol is a primary phenolic component of the Chinese medicinal herb Cortex moutan. Recent studies have shown that paeonol has anti-inflammatory, analgesic, and antioxidative effects as well as a significant cardioprotective effect against myocardial ischemia. OBJECTIVE： To investigate the protective effect of paeonol on β-amyloid 25-35-induced toxicity in PC12 cells and analyze its mechanism of action. DESIGN, TIME AND SETTING： A controlled repeated-measures cell-based study was performed in the Department of Pharmacology of Guangdong Medical College between September 2006 and December 2007. MATERIALS： Paeonol was supplied by Xuancheng Baicao Plant Industry and Trade Company, China. PC12 cells were a kind gift from Dr. Haitao Zhang at Guangdong Medical College. β-amyloid 25-35 was purchased from Sigma Company, USA. Lactate dehydrogenase （LDH） and malondialdehyde （MDA） kits were purchased from Nanjing Jiancheng Bioengineering Research Institute, China. METHODS： PC12 cells were maintained in Dulbecco＇s modified eagle＇s medium （DMEM） supplemented with 100 mL/L heat-inactivated horse serum and 50 mL/L fetal bovine serum at 37 ℃ and cultured in an incubator with 5% CO2. The medium was renewed every other day. Batches of cells were assigned into three groups. （1） Paeonol group： cells were preincubated with different concentrations of paeonol （12, 25 or 50 μmol/L） for one hour and β-amyloid 25-35 was added to the medium; （2） control group： cells were cultured in DMEM supplemented with 100 mL/L heat-inactivated horse serum and 50 mL/L fetal bovine serum; and （3） β-amyloid 25-35 group： β-amyloid 25-35 was added to the medium. MAIN OUTCOME MEASURES： When PC12 cells in each group were cultured for 24 hours, the cell viability was determined using the MTT reduction assay, LDH release into the culture media was measured by 2,4-dinitrophenylhydrazine chromatometry and MDA content was measured using a thiobarbituric acid assay. RESULTS： When PC12 cells were treated withβ-amyloid 25-35 （50 μmol/L） for 24 hours, their viability was significantly lower compared with the control group （P 〈 0.01）. When the cells were treated with paeonol for one hour prior to incubation withβ-amyloid 25-35, their viability was significantly increased compared with theβ-amyloid 25-35 group （P 〈 0.05–0.01）. LDH activity and MDA level in the β-amyloid 25-35 group were significantly increased compared with the control group （P 〈 0.01）. When the cells were treated with different concentrations of paeonol, LDH activity and MDA level in PC12 cells were significantly decreased compared with theβ-amyloid 25-35 group （P 〈 0.01）. CONCLUSION： Paeonol protects PC12 cells againstβ-amyloid 25-35-induced toxicity and the protective effect of paeonol is probably achieved through its antioxidative effects.

Overexpression of 14-3-3 protein protects pheochromocytoma cells against 1-methyl-4-phenylpyridinium toxicity

Objective To investigate the effects of 14-3-3 protein overexpression on the 1-methyl-4-phenylpyridinium （MPP^＋） induced pheochromocytoma （PC12） cell death and the potential mechanisms. Methods pcDNA3.1（＋）-14-3-3 plasmids, which could be expressed in mammalian cell, were constructed and transfected into PC 12 cells with Lipofectamine 2000. The expression of 14-3-3 protein, Bcl-2 protein, and BAD protein were determined by western blot. 3-（4,5- dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） assay, microplate reader, and flow cytometric analysis were used to measure cell viability, the caspase activity, and apoptotic ratio respectively. Results （1） The expression of 14-3-3 protein increased significantly three weeks after pcDNA3.1（＋）-14-3-3 plasmids transfected into PC 12 cells. （2） MPP^＋ caused a decrease of cell viability in a dose-dependent manner. At 100μmol/L MPP^＋, cell viability reduced approximately 50%. （3） The caspase activity increased along with the MPP^＋ concentrations rising and reached its maximum value （0.34 μmol/mg protein） at 100 μmol/L MPP＊. However caspase activity decreased significantly when the MPP^＋ concentration exceeded 100 μmol/L. （4） Overexpression of 14-3-3 protein decreased the apoptosis ratio of PC 12 cells treated with 100μmol/L MPP^＋ from 26.5% to 8.6%. （5） Bcl-2 protein tended to decrease but BAD protein tended to increase after treatment of PC 12 cells with 100 μmol/L MPP^＋. Overexpression of 14-3-3 protein significantly increased the cellular level of Bcl-2 protein and decreased that of BAD protein. Conclusion Overexpression of 14-3-3 protein may reduce MPP^＋-induced apoptotic cell death in PC12 cells by up-regulating the Bcl-2 expression and down-regulating the BAD expression. These results may provide a promising target for treatment of Parkinson＇s disease.

Assessment of Toxicity of BSA-conjugated Zinc Oxide Quantum Dots for C2C12 Cells

Colloidal semiconductor nanoparticles (quantum dots, QDs) have attracted a lot of interests in numerous biological and medical applications due to their potent fluorescent properties. However, the possible toxic effects of quantum dots remain an issue of debate. In this study, we aimed to evaluate the cytocompatibility of bovine serum albumin (BSA) conjugated zinc oxide QDs for C2C12 cells. In the experiment, ZnO QDs were synthesized by using BSA as the structure directing agent, and the morphology and crystal phase of ZnO QDs were determined by transmission electron microscopy, X-ray diffractograms and Fourier transform infrared spectrograph techniques. The inverted fluorescence microscope results showed that ZnO QDs were distributed inside the cells. The toxicity of ZnO QDs was assessed by MTT methods, which revealed that ZnO QDs were highly cytocompatible in the concentration less than 200 μM. However, when the concentration of QDs was higher than 1 000 μM ZnO QDs showed significantly toxicity, which was ascribed to generation of free zinc and formation of reactive oxygen species (ROS). Furthermore, the morphological observations exhibited that cells treated with ZnO QDs showed altered morphology, depolymerized cytoskeleton and irregular-shaped nuclei. This study provides helpful guidances on the future safe use and manipulation of QDs to make them suitable tools in nanomedicine.

NLR’s Analogs with Young Blood Cells in Monitoring of Toxicity of Long-Term Preventing Immunosuppression in the Liver Transplant’s Recipients

The blood neutrophils to lymphocytes ratio (NLR) reflects the physiological homeostasis between lymphopoiesis and myelopoiesis, and its elevation serves as a harmful sign in many pathologies, partially, late rejection of allograft. The stem and young lymphoid cells have regenerative-trophic properties, which can affect the relevance of NLR, being opposed to immune properties, associated with bulk lymphocytes. In the present article, we have analyzed for the first time the applicability of NLR’s analogs with stem and immature blood cells for monitoring harmful long-term shifting from lymphopoiesis to myelopoiesis in transplant’s recipients received conventional immunosuppressive treatment. In opposition to conventional NLR, the ratio of subpopulation of CD31 cells committed to the liver tissue by alfa-fetoprotein (AFP), seems sensitive enough for such monitoring several years after transplantation of the liver from the dead.

The Effects of <i>Ganoderma lucidum</i>on Initial Events Related to the <i>Bacillus Calmette-Guérin</i>Efficacy and Toxicity on High-Risk Uroepithelial Cells: An <i>in Vitro</i>Preliminary Study

A novel prophylactic regimen is demanded for preventing bladder cancer recurrence, because of the high side-effect tolls of conventional adjuvant Bacillus Calmette-Guérin (BCG) immunotherapy, in addition to its only moderate efficacy. In vitro and animal studies have demonstrated the anti-cancer properties of a medicinal mushroom called Ganoderma lucidum (GL). In this study, a pre-malignant human uroepithelial cells (HUC-PC) model was utilized to compare the effectiveness between ethanol extract of GL (GLe) and BCG on interleukin-6 (IL-6) secretion and lactate dehydrogenase (LDH) cytotoxicity. Additionally, parameters relevant to the BCG efficacy and safety, including free soluble fibronectin (FN) and cell-surface glycosaminoglycans (GAGs) levels were tested, following the exposure of GLe to the cells. GLe at 100 μg/ml and BCG at 4.8 × 107 CFU were shown to induce equivalent levels of IL-6, suggesting the potential synergism, while the tested concentrations of GLe were non-cytotoxic. During the initial four hours of GLe exposure, the free FN concentrations in harvested media were significantly reduced that might facilitate the binding of BCG for uroepithelial internalization to enhance BCG efficacy. Furthermore, the cell membrane-bound GAGs levels of HUC-PC cells were significant increased in response to GLe to suggest cellular protection from BCG infection. In summary, current findings suggest the potential additive synergism of GLe with the BCG efficacy, as well as its protective effects, and thus reducing the BCG toxicity.

Ferrostatin-1 protects HT-22 cells from oxidative toxicity

Ferroptosis is a type of programmed cell death dependent on iron.It is different from other forms of cell death such as apoptosis,classic necrosis and autophagy.Ferroptosis is involved in many neurodegenerative diseases.The role of ferroptosis in glutamate-induced neuronal toxicity is not fully understood.To test its toxicity,glutamate(1.25–20 mM)was applied to HT-22 cells for 12 to 48 hours.The optimal experimental conditions occurred at 12 hours after incubation with 5 mM glutamate.Cells were cultured with 3–12μM ferrostatin-1,an inhibitor of ferroptosis,for 12 hours before exposure to glutamate.The cell viability was detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.Autophagy was determined by monodansylcadaverine staining and apoptosis by caspase 3 activity.Damage to cell structures was observed under light and by transmission electron microscopy.The release of lactate dehydrogenase was detected by the commercial kit.Reactive oxygen species were measured by flow cytometry.Glutathione peroxidase activity,superoxide dismutase activity and malondialdehyde level were detected by the appropriate commercial kit.Prostaglandin peroxidase synthase 2 and glutathione peroxidase 4 gene expression was detected by real-time quantitative polymerase chain reaction.Glutathione peroxidase 4 and nuclear factor erythroid-derived-like 2 protein expression was detected by western blot analysis.Results showed that ferrostatin-1 can significantly counter the effects of glutamate on HT-22 cells,improving the survival rate,reducing the release of lactate dehydrogenase and reducing the damage to mitochondrial ultrastructure.However,it did not affect the caspase-3 expression and monodansylcadaverine-positive staining in glutamate-injured HT-22 cells.Ferrostatin-1 reduced the levels of reactive oxygen species and malondialdehyde and enhanced superoxide dismutase activity.It decreased gene expression of prostaglandin peroxidase synthase 2 and increased gene expression of glutathione peroxidase 4 and protein expressions of glutathione peroxidase 4 and nuclear factor(erythroid-derived)-like 2 in glutamate-injured HT-22 cells.Treatment of cultured cells with the apoptosis inhibitor Z-Val-Ala-Asp(OMe)-fluoromethyl ketone(2–8μM),autophagy inhibitor 3-methyladenine(100–400μM)or necrosis inhibitor necrostatin-1(10–40μM)had no effect on glutamate induced cell damage.However,the iron chelator deferoxamine mesylate salt inhibited glutamate induced cell death.Thus,the results suggested that ferroptosis is caused by glutamate-induced toxicity and that ferrostatin-1 protects HT-22 cells from glutamate-induced oxidative toxicity by inhibiting the oxidative stress.

The Cellular Toxicity of PM_(2.5) Emitted from Coal Combustion in Human Umbilical Vein Endothelial Cells

Objective To explore the relationship between different components of fine particulate matter（PM2.5） emitted from coal combustion and their cytotoxic effect in the vascular endothelial cells. Methods Coal-fired PM2.5 was sampled using a fixed-source dilution channel and flow sampler. The sample components were analyzed by ion chromatography and inductively coupled plasma atomic emission spectroscopy（ICP-AES）. The PM2.5 suspension was extracted using an ultrasonic water-bath method and then human umbilical vein endothelial cells（EA.hy926） were treated with various concentrations of the PM2.5 suspension. Cell proliferation, oxidative DNA damage, and global DNA methylation levels were used to measure the cellular toxicity of PM2.5 emitted from coal combustion. Results Compared to other types of coal-fired PM2.5 preparations, the PM2.5 suspension from Yinchuan coal had the highest cytotoxicity. PM2.5 suspension from Datong coal had the highest toxic effect while that from Yinchuan coal had the lowest. Exposure to coal-fired PM2.5 from Jingxi coal resulted in lower 8-hydroxy-2’-deoxyguanosine（8-OHd G） levels. At the same dose, PM2.5 emitted from coal combustion could produce more severe DNA impairment compared to that produced by carbon black. Cell survival rate was negatively correlated with chloride and potassium ions content. The 5-methylcytosine（5-m C） level was positively correlated with Mn and negatively correlated with Zn levels. The 8-OHd G% level was positively correlated with both Mn and Fe. Conclusion PM2.5 emitted from coal combustion can decrease cell viability, increase global DNA methylation, and cause oxidative DNA damage in EA.hy926 cells. Metal components may be important factors that influence cellular toxicity.

Negundoside,an irridiod glycoside from leaves of Vitex negundo,protects human liver cells against calcium-mediated toxicity induced by carbon tetrachloride

AIM： To evaluate the protective effect of 2′-p-hydroxy benzoylmussaenosidic acid [negundoside （NG）, against carbon tetrachloride （CCl4）-induced toxicity in HUH-7 cel Is.METHODS： CCI4 is a well characterized hepatotoxin, and inducer of cytochrome P450 2E1 （CYP2E1）-mediated oxidative stress. In addition, lipid peroxidation and accumulation of intracellular calcium are important steps in the pathway involved in CCl4 toxicity. Liver cells （HUH-7） were treated with CCI4, and the mechanism of the cytoprotective effect of NG was assessed. Silymarin, a known hepatoprotective drug, was used as control. RESULTS： NG protected HUH-7 cells against CCl4 toxicity and loss of viability without modulating CYP2E1 activity. Prevention of CCl4 toxicity was associated with a reduction in oxidative damage as reflected by decreased generation of reactive oxygen species （ROS）, a decrease in lipid peroxidation and accumulation of intracellular Ca^2＋ levels and maintenance of intracellular glutathione homeostasis. Decreased mitochondrial membrane potential （MMP）, induction of caspases mediated DNA fragmentation and cell cycle arrest, as a result of CCl4 treatment, were also blocked by NG. The protection afforded by NG seemed to be mediated by activation of cyclic adenosine monophosphate （cAMP） synthesis and inhibition of phospholipases （cPLA2）. CONCLUSION： NG exerts a protective effect on CYP2E1-dependent CCl4 toxicity via inhibition of lipid peroxidation, followed by an improved intracellular calcium homeostasis and inhibition of Ca^2＋-dependent proteases.

A Study of Toxicity of 5-Fluorouracil on Bovine Trabecular Meshwork Cells in Vitro

In order to explore whether the conventional use of 5 fluorouracil (5 Fu) had any toxic effects on trabecular meshwork cells, bovine trabecular meshwork cells were cultured in vitro and exposed to 5 Fu at different concentrations. The cellular morphology, ultrastructure, mortality and phagocytosis were studied under light microscopy, transmission electron microscopy and methods of Wright's stain. It was found that the toxic effects of 5 Fu on the cells were in a dose dependent mode. 1×10 -1 mg/ml of 5 Fu caused a large part of cells rounded up, while 1×10 -3 mg/ml of the drug only a rough appearance of the cell surface. Exposure to 1×10 -2 mg/ml of 5 Fu made mitochrone swollen and rough endoplasmic reticulum enlarged, with the cell mortality being 50.5 %. The latex microspheres engulfed in cytoplasm in cells receiving 1×10 -1 and 1×10 -2 mg/ml of 5 Fu were significantly decreased as compared with those in the control group ( P <0.01). It was concluded that the safe concentration of 5 Fu on bovine trabecular meshwork cells was 1×10 -3 mg/ml and the conventional dosage of 5 Fu in clinical practice would not cause injury to trabecular meshwork cells.

Availability and toxicity of Fe(II) and Fe(III) in Caco-2 cells

The objective of the present study was to compare the toxicity and availability of Fe(II) and Fe(III) to Caco-2 cells. Cellular damage was studied by measuring cell proliferation and lactate dehydrogenase (LDH) release. The activities of two major antioxidative enzymes [superoxide dismutase (SOD) and glutathione peroxidase (GPx)] and differentiation marker (alkaline phosphatase) were determined after the cells were exposed to different levels of iron salts. The cellular iron concentration was investigated to evaluate iron bioavailability. The results show that iron uptake of the cells treated with Fe(II) is significantly higher than that of the cells treated with Fe(III) (P<0.05). Fe(II) at a concentration >1.5 mmol/L was found to be more effective in reducing cellular viability than Fe(III). LDH release investigation suggests that Fe(II) can reduce stability of the cell membrane. The activities of SOD and GPx of the cells treated with Fe(II) were higher than those of the cells treated with Fe(III), although both of them increased with raising iron supply levels. The results indicate that both Fe(II) and Fe(III) could reduce the cellular antioxidase gene expression at high levels.

Meningeal lymphatic vessel crosstalk with central nervous system immune cells in aging and neurodegenerative diseases

Meningeal lymphatic vessels form a relationship between the nervous system and periphery, which is relevant in both health and disease. Meningeal lymphatic vessels not only play a key role in the drainage of brain metabolites but also contribute to antigen delivery and immune cell activation. The advent of novel genomic technologies has enabled rapid progress in the characterization of myeloid and lymphoid cells and their interactions with meningeal lymphatic vessels within the central nervous system. In this review, we provide an overview of the multifaceted roles of meningeal lymphatic vessels within the context of the central nervous system immune network, highlighting recent discoveries on the immunological niche provided by meningeal lymphatic vessels. Furthermore, we delve into the mechanisms of crosstalk between meningeal lymphatic vessels and immune cells in the central nervous system under both homeostatic conditions and neurodegenerative diseases, discussing how these interactions shape the pathological outcomes. Regulation of meningeal lymphatic vessel function and structure can influence lymphatic drainage, cerebrospinal fluid-borne immune modulators, and immune cell populations in aging and neurodegenerative disorders, thereby playing a key role in shaping meningeal and brain parenchyma immunity.

Attenuating effect of daidzein on polychlorinated biphenyls-induced oxidative toxicity in mouse testicular cells

The attenuating effect of daidzein (DAI) on oxidative toxicity induced by Aroclor 1254 (A1254) was investigated in mouse testicular cells. Cells were exposed to A1254 alone or with DAI. The oxidative damage was estimated by measuring malondialdehyde (MDA) formation, superoxide dismutase (SOD) activity and glutathione (GSH) content. Results show that A1254 induced a decrease of germ cell number, an elevation in thiobarbituric acid reactive substances (TBARS) but a decrease in SOD activity and GSH content. However, simultaneous supplementation with DAI decreased TBARS level and increased SOD activity and GSH content. Consequently, dietary DAI may restore the intracellular antioxidant system to attenuate the oxidative toxicity of A1254 in testicular cells.

Hot Debate on perovskite solar cells: Stability, toxicity, high-efficiency and low cost

Photovoltaic technology is a promising choice for human beings to solve critical environmental and energy problems. Much effort has been expended around the world on this technology which has allowed it to flourish, both in power conversion efficiency (PCE) and market share in the global energy supply sector.

Therapeutic and regenerative potential of different sources of mesenchymal stem cells for cardiovascular diseases

Mesenchymalstemcells(MSCs)areidealcandidatesfortreatingmanycardiovasculardiseases.MSCscanmodify the internal cardiac microenvironment to facilitate their immunomodulatory and differentiation abilities,which are essential to restore heart function.MSCs can be easily isolated from different sources,including bone marrow,adipose tissues,umbilical cord,and dental pulp.MSCs from various sources differ in their regenerative and therapeutic abilities for cardiovascular disorders.In this review,we will summarize the therapeutic potential of each MSC source for heart diseases and highlight the possible molecular mechanisms of each source to restore cardiac function.

The combined application of stem cells and three-dimensional bioprinting scaffolds for the repair of spinal cord injury

Spinal cord injury is considered one of the most difficult injuries to repair and has one of the worst prognoses for injuries to the nervous system.Following surgery,the poor regenerative capacity of nerve cells and the generation of new scars can make it very difficult for the impaired nervous system to restore its neural functionality.Traditional treatments can only alleviate secondary injuries but cannot fundamentally repair the spinal cord.Consequently,there is a critical need to develop new treatments to promote functional repair after spinal cord injury.Over recent years,there have been seve ral developments in the use of stem cell therapy for the treatment of spinal cord injury.Alongside significant developments in the field of tissue engineering,three-dimensional bioprinting technology has become a hot research topic due to its ability to accurately print complex structures.This led to the loading of three-dimensional bioprinting scaffolds which provided precise cell localization.These three-dimensional bioprinting scaffolds co uld repair damaged neural circuits and had the potential to repair the damaged spinal cord.In this review,we discuss the mechanisms underlying simple stem cell therapy,the application of different types of stem cells for the treatment of spinal cord injury,and the different manufa cturing methods for three-dimensional bioprinting scaffolds.In particular,we focus on the development of three-dimensional bioprinting scaffolds for the treatment of spinal cord injury.

Proteomics Study of Benzene Metabolite Hydroquinone Induced Hematotoxicity in K562 Cells

Objective Hydroquinone(HQ),one of the phenolic metabolites of benzene,is widely recognized as an important participant in benzene-induced hematotoxicity.However,there are few relevant proteomics in HQ-induced hematotoxicity and the mechanism hasn’t been fully understood yet.Methods In this study,we treated K562 cells with 40μmol/L HQ for 72 h,examined and validated protein expression changes by Label-free proteomic analysis and Parallel reaction monitoring(PRM),and performed bioinformatics analysis to identify interaction networks.Results One hundred and eighty-seven upregulated differentially expressed proteins(DEPs)and 279 downregulated DEPs were identified in HQ-exposed K562 cells,which were involved in neutrophilmediated immunity,blood microparticle,and other GO terms,as well as the lysosome,metabolic,cell cycle,and cellular senescence-related pathways.Focusing on the 23 DEGs and 5 DEPs in erythroid differentiation-related pathways,we constructed the network of protein interactions and determined 6 DEPs(STAT1,STAT3,CASP3,KIT,STAT5B,and VEGFA)as main hub proteins with the most interactions,among which STATs made a central impact and may be potential biomarkers of HQ-induced hematotoxicity.Conclusion Our work reinforced the use of proteomics and bioinformatic approaches to advance knowledge on molecular mechanisms of HQ-induced hematotoxicity at the protein level and provide a valuable basis for further clarification.

Small extracellular vesicles derived from cerebral endothelial cells with elevated microRNA 27a promote ischemic stroke recovery

Axonal remodeling is a critical aspect of ischemic brain repair processes and contributes to spontaneous functional recovery.Our previous in vitro study demonstrated that exosomes/small extracellular vesicles(sEVs)isolated from cerebral endothelial cells(CEC-sEVs)of ischemic brain promote axonal growth of embryonic cortical neurons and that microRNA 27a(miR-27a)is an elevated miRNA in ischemic CEC-sEVs.In the present study,we investigated whether normal CEC-sEVs engineered to enrich their levels of miR-27a(27a-sEVs)further enhance axonal growth and improve neurological outcomes after ischemic stroke when compared with treatment with non-engineered CEC-sEVs.27a-sEVs were isolated from the conditioned medium of healthy mouse CECs transfected with a lentiviral miR-27a expression vector.Small EVs isolated from CECs transfected with a scramble vector(Scra-sEVs)were used as a control.Adult male mice were subjected to permanent middle cerebral artery occlusion and then were randomly treated with 27a-sEVs or Scra-sEVs.An array of behavior assays was used to measure neurological function.Compared with treatment of ischemic stroke with Scra-sEVs,treatment with 27a-sEVs significantly augmented axons and spines in the peri-infarct zone and in the corticospinal tract of the spinal grey matter of the denervated side,and significantly improved neurological outcomes.In vitro studies demonstrated that CEC-sEVs carrying reduced miR-27a abolished 27a-sEV-augmented axonal growth.Ultrastructural analysis revealed that 27a-sEVs systemically administered preferentially localized to the pre-synaptic active zone,while quantitative reverse transcription-polymerase chain reaction and Western Blot analysis showed elevated miR-27a,and reduced axonal inhibitory proteins Semaphorin 6A and Ras Homolog Family Member A in the peri-infarct zone.Blockage of the Clathrin-dependent endocytosis pathway substantially reduced neuronal internalization of 27a-sEVs.Our data provide evidence that 27a-sEVs have a therapeutic effect on stroke recovery by promoting axonal remodeling and improving neurological outcomes.Our findings also suggest that suppression of axonal inhibitory proteins such as Semaphorin 6A may contribute to the beneficial effect of 27a-sEVs on axonal remodeling.