Bromocriptine protects perilesional spinal cord neurons from lipotoxicity after spinal cord injury

Recent studies have revealed that lipid droplets accumulate in neurons after brain injury and evoke lipotoxicity,damaging the neurons.However,how lipids are metabolized by spinal cord neurons after spinal cord injury remains unclear.Herein,we investigated lipid metabolism by spinal cord neurons after spinal cord injury and identified lipid-lowering compounds to treat spinal cord injury.We found that lipid droplets accumulated in perilesional spinal cord neurons after spinal cord injury in mice.Lipid droplet accumulation could be induced by myelin debris in HT22 cells.Myelin debris degradation by phospholipase led to massive free fatty acid production,which increased lipid droplet synthesis,β-oxidation,and oxidative phosphorylation.Excessive oxidative phosphorylation increased reactive oxygen species generation,which led to increased lipid peroxidation and HT22 cell apoptosis.Bromocriptine was identified as a lipid-lowering compound that inhibited phosphorylation of cytosolic phospholipase A2 by reducing the phosphorylation of extracellular signal-regulated kinases 1/2 in the mitogen-activated protein kinase pathway,thereby inhibiting myelin debris degradation by cytosolic phospholipase A2 and alleviating lipid droplet accumulation in myelin debris-treated HT22 cells.Motor function,lipid droplet accumulation in spinal cord neurons and neuronal survival were all improved in bromocriptine-treated mice after spinal cord injury.The results suggest that bromocriptine can protect neurons from lipotoxic damage after spinal cord injury via the extracellular signal-regulated kinases 1/2-cytosolic phospholipase A2 pathway.

NOX4 promotes tumor progression through the MAPK-MEK1/2-ERK1/2 axis in colorectal cancer

BACKGROUND Metabolic reprogramming plays a key role in cancer progression and clinical outcomes;however,the patterns and primary regulators of metabolic reprogramming in colorectal cancer(CRC)are not well understood.AIM To explore the role of nicotinamide adenine dinucleotide phosphate oxidase 4(NOX4)in promoting progression of CRC.METHODS We evaluated the expression and function of dysregulated and survival-related metabolic genes using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes.Consensus clustering was used to cluster CRC based on dysregulated metabolic genes.A prediction model was constructed based on survival-related metabolic genes.Sphere formation,migration,invasion,proliferation,apoptosis and clone formation was used to evaluate the biological function of NOX4 in CRC.mRNA sequencing was utilized to explore the alterations of gene expression NOX4 over-expression tumor cells.In vivo subcutaneous and lung metastasis mouse tumor model was used to explore the effect of NOX4 on tumor growth.RESULTS We comprehensively analyzed 3341 metabolic genes in CRC and identified three clusters based on dysregulated metabolic genes.Among these genes,NOX4 was highly expressed in tumor tissues and correlated with worse survival.In vitro,NOX4 overexpression induced clone formation,migration,invasion,and stemness in CRC cells.Furthermore,RNA-sequencing analysis revealed that NOX4 overexpression activated the mitogen-activated protein kinase-MEK1/2-ERK1/2 signaling pathway.Trametinib,a MEK1/2 inhibitor,abolished the NOX4-mediated tumor progression.In vivo,NOX4 overexpression promoted subcutaneous tumor growth and lung metastasis,whereas trametinib treatment can reversed the metastasis.CONCLUSION Our study comprehensively analyzed metabolic gene expression and highlighted the importance of NOX4 in promoting CRC metastasis,suggesting that trametinib could be a potential therapeutic drugs of CRC clinical therapy targeting NOX4.

抑制ERK1/2通路对卡铂诱导人卵巢癌细胞凋亡的影响

目的:探讨抑制ERK1/2通路对卡铂诱导卵巢癌细胞凋亡作用的影响。方法:采用Hoechst 33258荧光染色法检测抑制ERK1/2通路对卡铂诱导卵巢癌HO-8910细胞凋亡的影响;用分光光度法检测卡铂浓度的增加及抑制ERK1/2通路对卵巢癌HO-8910细胞Caspase-8和Caspase-9活化的影响。结果:CBP组、PD98059组及联用组部分细胞核呈现亮蓝色荧光的为凋亡细胞,细胞核可见碎块状荧光信号,凋亡指数CBP组为20.35%,PD98059组为15.21%,联用组为29.78%。随着卡铂浓度的增加,Caspase-8、Caspase-9活性的改变并不明显(P>0.05),而联用组的Caspase-8、Caspase-9活性最高,抑制ERK1/2通路可促进卡铂增强Caspase-8、Caspase-9的活性(P<0.01)。结论:抑制ERK1/2通路可促进卡铂诱导卵巢癌细胞凋亡作用,并与Caspase-8、Caspase-9活化有关。

Oxidative stress and mitochondrial dysfunction of retinal ganglion cells injury exposures in long-term blue light

AIM:To investigate the phototoxic effect of long-term excessive narrow-band blue light in staurosporine-induced differentiated retinal ganglion cells-5(SSRGC-5).METHODS:SSRGC-5 cells were divided into two groups,blue light group(BL group)and control group.Cell viability was assessed by using CCK-8 assay.Metabolic profile analysis was performed by using Seahorse extracellular flux analyzer.Mitochondria ultrastructure were studied via transmission electron microscope(TEM).Mitochondria contents and oxidative stress was evaluated by flow cytometry.Western blotting was performed to monitor the changes in mitogen-activated protein kinases(MAPK)pathway and PI3 K/AKT pathway.RESULTS:Blue light caused morphological changes of SSRGC-5 cells.The cell viability was significantly decreased from 3 h in BL group.Intercellular ROS and mitochondrial superoxide levels were increased following blue light exposure.Metabolic profiling identified blue light induced SSRGC-5 cells to have severely compromised mitochondrial function.This was accompanied by impaired mitochondrial ultrastructure and remodeling,increased expression of the mitochondrial related proteins,and increased glycolysis as compensation.Moreover,the results showed that blue light induced higher expression of p-p38,p38,p-JNK,p-ERK,p-cJun,c-Jun,and p-AKT.CONCLUSION:These findings indicate that excessive narrow-band blue light induces oxidative stress and mitochondrial metabolic remodeling dysregulate in SSRGC-5 cells.Activated MAPK and AKT signaling pathways are involved in this process.