The effect and mechanism of sphingosine kinase-1 knockdown on non-small cell lung cancer cell proliferation and mitochondrial apoptotic pathway / 生理学报

The purpose of the present study was to investigate the effect and potential mechanism of knockdown of sphingosine kinase-1 (SPHK1) on the proliferation, cell cycle and apoptosis of non-small cell lung cancer (NSCLC) cells. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to detect SPHK1 mRNA expression in human healthy lung fibroblasts (MRC-5 cells) and four NSCLC cell lines. Then, A549 and H1299 cells were transfected with SPHK1-shRNA and corresponding negative control. CCK-8, Annexin V-FITC/PI dual staining and cell cycle assay were performed to evaluate cell proliferation, apoptosis and cell cycle distribution, respectively. JC-1 mitochondrial membrane potential measurement kit was adopted to measure mitochondrial membrane potential. Western blot was used to detect the protein expression levels of cell cycle and mitochondrial apoptotic pathway-related proteins, as well as MEK/ERK signaling pathway. The results showed that the mRNA expression of SPHK1 in NSCLC cells was higher than that in MRC-5 cells. SPHK1-shRNA significantly inhibited the proliferation of A549 and H1299 cells, blocked the cell cycle in G0/G1 phase, and promoted cell apoptosis through the mitochondrial pathway. Compared with the control group, the expression of p-MEK and p-ERK proteins in the SPHK1-shRNA group was significantly down-regulated. Moreover, MEK/ERK inhibitor could dramatically suppress cell proliferation and promote cell apoptosis. These results suggest that SPHK1 knockdown can inhibit the proliferation of NSCLC cells and might promote mitochondrial apoptotic pathway by inhibiting MEK/ERK signaling pathway.

Therapeutic Effect of SPK1 Gene Transfected Adipose Derived Mesenchymal Stem Cells on Experimental Autoimmune Encephalomyelitis Mice and Its Effect on T Helper Cell 17/Regulatory T Cells Balance / 中国医学科学院学报

Objective To investigate the therapeutic effect of SPK1 gene transfected adipose derived mesenchymal stem cells(ADMSC)on experimental autoimmune encephalomyelitis mice and the effect on T helper cell 17(Th17)/regulatory T(Treg) cells balance. Methods EAE was induced by myelin oligodendrocyte glycoprotein 35-55 in mice.Totally 44 mice were randomly divided into four groups:normal control group(NC group),model group(EAE group),ADMSC group,and ADMSC-SPK1 group.Forty days after injection,the pathological changes of brain and spinal cord,Th17/Treg-related inflammatory markers in brain tissue,expressions of interleukin-17A(IL-17A)and forkhead box protein p3(Foxp3)in brain and spinal cord tissue,and flow cytometric results of spleen immune cells were detected. Results Forty days after the injection,serious inflammatory cell infiltration and demyelination occurred in the brain and spinal cord of EAE group,whereas demyelination and axonal injury were improved in ADMSC group and ADMSC-SPK1 group.Compared with EAE group,the ADMSC group and ADMSC-SPK1 group had significantly improved levels of IL-17A(

Identification of a novel DGUOK variant in a Chinese family affected with mitochondrial DNA depletion syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the molecular etiology for a Chinese family with mitochondrial DNA depletion syndrome.@*METHODS@#Genomic DNA was extracted from peripheral blood samples of the patient and her parents.Targeted capture and next-generation sequencing was carried out to detect potential variants. Suspected variant was validated by Sanger sequencing.@*RESULTS@#A novel homozygous frameshift variant c.505_508delTATC was identified in the patient, for which both his mother and father were carriers.@*CONCLUSION@#The frameshift variant c.505_508delTATC probably underlies the mitochondrial DNA depletion syndrome in this patient. The result also enriched the variant spectrum of DGUOK gene.

Altered expressions of SphK1 and S1PR2 in hippocampus of epileptic rats / 中国应用生理学杂志

OBJECTIVE@#To observe the expressions of sphingosine kinase 1 (SphK1) and sphingosine-1-phosphate receptor 2 (S1PR2) in hippocampus of epileptic rats and to investigate the pathogenesis of SphK1 and S1PR2 in epilepsy.@*METHODS@#One hundred and eight male Sprague-Dawley (SD) rats were randomly divided into control group (n=48) and pilocarpine (PILO) group (n=60). A robust convulsive status epilepticus (SE) was induced in PILO group rats by the application of pilocarpine. Control group rats were injected with respective of physiological saline. Pilocarpine group was randomly divided into 6 subgroups (n=8): acute group (E6 h, E1 d, E3 d), latent group (E7 d) and chronic group (E30 d, E56 d). Each subgroup has 8 control rats and 8 epileptic rats. Hippocampal tissue and brain slices were obtained from control rats and rats subjected to the Li-PILO model of epilepsy at 6 h, 1 d, 3 d,7 d,30 d and 56 d after status epilepticus (SE). Western blot technique was used to determine the expressions of SphK1 and S1PR2 in hippocampus at different point of time after pilocarpine treatment. Immunofluorescence was applied to detect the activation and proliferation of hippocampal astrocytes and the localization of SphK1 and S1PR2 in rat hippocampal astrocytes.@*RESULTS@#Compared with control group, the levels of SphK1 in acute phase (E3 d), latent phase (E7 d) and chronic phase (E30 d, E56 d) were significantly increased while the expressions of S1PR2 were decreased in acute phase (E3 d), latent phase (E7 d) and chronic phase (E30 d, E56 d)(P＜0.05 or P＜0.01). Immunofluorescence results showed astrocyte activation and proliferation in hippocampus of epileptic (E7 d) rats (P＜0.05). Confocal microscopy confirmed the preferential expressions of SphK1 and S1PR2 in epileptic rat(E7 d)hippocampal astrocytes.@*CONCLUSION@#The results indicate that SphK1 and S1PR2 may play an important role in the pathogenesis of epilepsy by regulating the activation and proliferation of hippocampal astrocytes and altering neuronal excitability.

A novel oncolytic adenovirus inhibits hepatocellular carcinoma growth / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

OBJECTIVE@#To evaluate the inhibitory role of a novel oncolytic adenovirus (OA), GP73-SphK1sR-Ad5, on the growth of hepatocellular carcinoma (HCC).@*METHODS@#GP73-SphK1sR-Ad5 was constructed by integrating Golgi protein 73 (GP73) promoter and sphingosine kinase 1 (SphK1)-short hairpin RNA (shRNA) into adenovirus serotype 5 (Ad5), and transfecting into HCC Huh7 cells and normal human liver HL-7702 cells. The expression of SphK1 and adenovirus early region 1 (E1A) was detected by quantitative real-time PCR (qRT-PCR) and western blot, respectively. Cell viability was detected by methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay, and apoptotic rate was determined by flow cytometry. An Huh7 xenograft model was established in mice injected intratumorally with GP73-SphK1sR-Ad5. Twenty days after injection, the tumor volume and weight, and the survival time of the mice were recorded. The histopathological changes in tumor tissues were observed by hematoxylin-eosin (HE) staining and transmission electron microscopy (TEM).@*RESULTS@#Transfection of GP73-SphK1sR-Ad5 significantly upregulated E1A and downregulated SphK1 in Huh7 cells, but not in HL7702 cells. GP73-SphK1sR-Ad5 transfection significantly decreased the viability and increased the apoptotic rate of Huh7 cells, but had no effect on HL7702 cells. Intratumoral injection of GP73-SphK1sR-Ad5 into the Huh7 xenograft mouse model significantly decreased tumor volume and weight, and prolonged survival time. It also significantly decreased the tumor infiltration area and blood vessel density, and increased the percentages of cells with nucleus deformation and cells with condensed chromatin in tumor tissues.@*CONCLUSIONS@#GP73-SphK1sR-Ad5 serves as a novel OA and can inhibit HCC progression with high specificity and efficacy.

Clinical characteristics and molecular pathogenesis of pantothenate kinase-associated neurodegenerative disease / 中华医学遗传学杂志

Pantothenate kinase-associated neurodegenerative diseases is a type of neurodegeneration with brain iron accumulation characterized by excessive iron deposition in specific parts of the brain. The phenotypic spectrum includes classic and atypical PKAN. The clinical presentation may range from speech disorder to severe dystonia, dysphagia, mental retardation and retinal degeneration. It is an autosomal recessive disorder characterized by a variant in the PANK2 gene, pathogenesis involves mitochondrial dysfunction, oxidative stress damage, lipid metabolism disorders and autophagy disorders. This review summarizes the clinical presentation, molecular pathogenesis, imaging modalities and genetics.

ITPKC and SLC11A1 Gene Polymorphisms and Gene-Gene Interactions in Korean Patients with Kawasaki Disease

PURPOSE: Kawasaki disease (KD) is an acute systemic vasculitis. Both the etiology of KD and the erythema of Bacille Calmette-Guérin (BCG) injection sites observed in the disease are poorly understood. We investigated the association between KD and single nucleotide polymorphisms (SNPs) in two candidate genes: inositol 1,4,5-triphosphate 3-kinase (ITPKC), a well-studied KD-associated gene, and solute carrier 11a1 (SLC11A1), which is associated with the hypersensitive reaction to the BCG strain in Koreans. MATERIALS AND METHODS: Associations between KD and SNPs in two genes were evaluated. Potential associations between BCG injection site erythema and SNPs in two genes were also evaluated. Gene-gene interactions between ITPKC and SLC11A1 in KD and BCG injection site erythema were also analyzed. RESULTS: Three tagging SNPs in ITPKC and five tagging SNPs in SLC11A1 were genotyped in 299 KD patients and 210 control children. SNP rs28493229 in ITPKC was associated with KD and coronary artery complications. SNP rs77624405 in SLC11A1 was associated with KD. Comparisons of KD patients with and without BCG injection site erythema revealed that SNP rs17235409 in SLC11A1 was associated with erythema; no erythema-associated SNPs in ITPKC were identified. Interactions between ITPKC rs28493229_GG and SLC11A1 rs17235409_GA and between ITPKC rs10420685_GG and SLC11A1 rs17235409_AA were strongly associated with BCG injection site erythema. CONCLUSION: This study identified several important polymorphisms in the ITPKC and SLC11A1 genes in Koreans. The genetic variants identified in this study affected KD and erythema of BCG injection sites independently and through gene-gene interactions. Also, the effects of the polymorphisms were age-dependent.

Clinical features and DGUOK mutations of an infant with mitochondrial DNA depletion syndrome / 中国当代儿科杂志

The aim of this study was to investigate the clinical features and DGUOK gene mutations of an infant with mitochondrial DNA depletion syndrome (MDS). The patient (more than 7 months old) manifested as hepatosplenomegaly, abnormal liver function, nystagmus and psychomotor retardation. Genetic DNA was extracted from peripheral blood samples of the patient and her parents. Targeted Exome Sequencing was performed to explore the genetic causes. Sanger sequencing was carried out to confirm the detected mutations. The sequencing results showed that the patient was a compound heterozygote for c.679G>A and c.817delT in the DGUOK gene. The former was a reportedly pathogenic missense mutation of maternal origin, while the latter, a frameshift mutation from the father, has not been described yet. The findings in this study expand the mutation spectrum of DGUOK gene, and provide molecular evidence for the etiologic diagnosis of the patient as well as for the genetic counseling and prenatal diagnosis in the family.

Sphingosine Kinase 1 urothelial expression is increased in patients with neurogenic detrusor overactivity

Objectives: To evaluate the expression of sphingosine kinase 1 (SPK1) in the bladder wall in patients with neurogenic lower urinary tract dysfunction and its association with clinical, urodynamic and pathological features. Materials and Methods: The expression of SPK1 was studied in bladder wall specimens obtained from cystectomy using immunohistochemistry in ten patients with spinal cord injury (n=8) or multiple sclerosis (n=2) with urodynamically proven neuropathic bladder dysfunction, and in controls (n=5). Inflammation and fibrosis were analysed with histological criteria and SPK1 expression was determined by individual immunohistochemical staining. Results: Significant increased SPK1 urothelial immunoreactivity was shown in patients compared to control group (p=0.03). By contrast, SPK1 immunoreactivity in patients was significantly decreased in the sub-urothelium, muscles and nerves, p=0.02; 0.01 and 0.003, respectively. Patients with neurogenic detrusor overactivity (NDO) had higher SPK1 urothelium expression than those without any DO (p=0.04). Conclusions: SPK1 is expressed in the human bladder wall, specifically the urothelium, in bladder specimens from patients with NDO. The role of SPK1 in the pathophysiology of NDO needs further elucidation.

Sphingosine kinase 1 promotes glioma cell proliferation under hypoxia via calcium signaling / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the role of sphingosine kinase 1 (SphK1) in regulating the proliferation of hypoxia-exposed glioma cells in vitro and explore the possible molecular mechanisms.</p><p><b>METHODS</b>Human glioblastoma U87MG cells was transfected with specific small interfering RNA (siRNA) constructs targeting SphK1, and the efficiency of SphK1 knockdown was validated by real-time PCR and Western blotting. The cells transfected with SphK1 siRNA and with a negative control siRNA were then exposed to 3% oxygen or 150 µmol/L CoCl2 to induce hypoxia. The cell proliferation and cell cycle changes following the exposure were evaluated with the Cell Counting Kit-8 and flow cytometry, respectively, and the intracellular Ca(2+) changes were monitored using Flou-4/AM under an inverted laser scanning confocal microscope.</p><p><b>RESULTS</b>SphK1 knockdown significantly reduced hypoxia-induced calcium reflux and suppressed the cell proliferation. Application of OAG, an activator of calcium channels, however, obviously enhanced the cell proliferation under hypoxia.</p><p><b>CONCLUSION</b>SphK1 promotes the proliferation of glioma cells under hypoxia via regulating calcium signaling.</p>

N-acetyl-D-glucosamine kinase interacts with dynein light-chain roadblock type 1 at Golgi outposts in neuronal dendritic branch points

N-acetylglucosamine kinase (GlcNAc kinase or NAGK) is a ubiquitously expressed enzyme in mammalian cells. Recent studies have shown that NAGK has an essential structural, non-enzymatic role in the upregulation of dendritogenesis. In this study, we conducted yeast two-hybrid screening to search for NAGK-binding proteins and found a specific interaction between NAGK and dynein light-chain roadblock type 1 (DYNLRB1). Immunocytochemistry (ICC) on hippocampal neurons using antibodies against NAGK and DYNLRB1 or dynein heavy chain showed some colocalization, which was increased by treating the live cells with a crosslinker. A proximity ligation assay (PLA) of NAGK-dynein followed by tubulin ICC showed the localization of PLA signals on microtubule fibers at dendritic branch points. NAGK-dynein PLA combined with Golgi ICC showed the colocalization of PLA signals with somal Golgi facing the apical dendrite and with Golgi outposts in dendritic branch points and distensions. NAGK-Golgi PLA followed by tubulin or DYNLRB1 ICC showed that PLA signals colocalize with DYNLRB1 at dendritic branch points and at somal Golgi, indicating a tripartite interaction between NAGK, dynein and Golgi. Finally, the ectopic introduction of a small peptide derived from the C-terminal amino acids 74-96 of DYNLRB1 resulted in the stunting of hippocampal neuron dendrites in culture. Our data indicate that the NAGK-dynein-Golgi tripartite interaction at dendritic branch points functions to regulate dendritic growth and/or branching.

Cloning and expression analysis of 4- (cytidine-5-diphospho) -2-C-methyl-D-erythritol kinase gene in Tripterygium wilfordii / 中国中药杂志

4-(Cytidine-5-diphospho) -2-C-methyl-D-erythritol kinase is a key enzyme in the biosynthesis pathway of terpenoids. According to the transcriptome database, the specific primers were designed and used in PCR. The bioinformatic analysis of the sequenced TwCMK gene was performed in several bioinformatics software. The Real-time fluorescence quantification polymerase chain reaction (RT-qPCR) were used to detect the expression levels of TwCMK from T. wilfordii after elicitor MeJA supplied. The results showed that the full length of TwCMK cDNA was 1 732 bp encoding 387 amino acids. The theoretical isoelectric point of the putative TwCMK protein was 5.79 and the molecular weight was about 42.85 kDa. MeJA stimulated the rising of TwCMK expression in suspension cell and signally impacted at 24 h. The research provides a basis for further study on the regulation of terpenoid secondary metabolism and biological synthesis.

Assessment of primary health care: health professionals’ perspective / Evaluación de la atención primária em la salud: vision de los profissionales de la salud / Avaliação da Atenção Primária à Saúde: visão dos profissionais de saúde

Objective To assess primary health care attributes of access to a first contact, comprehensiveness, coordination, continuity, family guidance and community orientation. Method An evaluative, quantitative and cross-sectional study with 35 professional teams in the Family Health Program of the Alfenas region, Minas Gerais, Brazil. Data collection was done with the Primary Care Assessment Tool - Brazil, professional version. Results Results revealed a low percentage of medical experts among the participants who evaluated the attributes with high scores, with the exception of access to a first contact. Data analysis revealed needs for improvement: hours of service; forms of communication between clients and healthcare services and between clients and professionals; the mechanism of counter-referral. Conclusion It was concluded that there is a mismatch between the provision of services and the needs of the population, which compromises the quality of primary health care.


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Objetivo Evaluar la atención primaria de salud a través de las cualidades: Acesso de Primero Contacto, Intregidad, Coordinación, Longitudinalidad, Orientación Familiar, Orientación Comunitaria. Método Se trata de una evaluación cuantitativa y estudio transverso con 35 equipos de profesionales de la Estrategia de Salud de la Familia, de región de Alfenas, Minas Gerais, Brasil. Para recopilar los datos, se utilizó el Instrumento de Evaluación de la Atención Primaria - Brasil , la versión Professional. Resultados Los datos revelaron un bajo porcentaje de especialistas médicos en Atencion Primaria de Salud. Los participantes evaluó las calidades con puntajes altos, con la excepción de Acceso Primero Contacto. El análisis de datos reveló una mejora necesidades: horarios de apertura de los servicios; las formas de comunicación entre el usuario y el servicio y entre el usuario y el profesional, la remissión y consulta. Conclusión Existe un desajuste entre la oferta de servicios y las necesidades de la población, lo que compromete la calidad de la Atención Primaria de Salud.
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Objetivo Avaliar a Atenção Primária à Saúde por meio dos atributos: Acesso de Primeiro Contato, Integralidade, Coordenação, Longitudinalidade, Orientação Familiar, Orientação Comunitária. Método Estudo avaliativo, quantitativo e transversal, realizado com 34 profissionais de equipes da Estratégia de Saúde da Família da microrregião de Alfenas, Minas Gerais, Brasil. Para a coleta de dados, foi utilizado o Primary Care Assessment Tool – Brasil, versão profissionais. Resultados Os dados revelaram baixo percentual de profissionais médicos especialistas em Atenção Primária à Saúde. Os participantes avaliaram os atributos com altos escores, com exceção do Acesso de Primeiro Contato. A análise dos dados revelou necessidades de aperfeiçoamento: o horário de funcionamento dos serviços; as formas de comunicação entre usuário e serviço, e entre usuário e profissionais; o mecanismo de contrarreferência. Conclusão Existe um descompasso entre a oferta de serviços e as necessidades da população que compromete a qualidade da Atenção Primária a Saúde.
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Dual inhibition of EGFR at protein and activity level via combinatorial blocking of PI4KIIα as anti-tumor strategy

Our previous studies indicate that phosphatidylinositol 4-kinase IIα can promote the growth of multi-malignant tumors via HER-2/PI3K and MAPK pathways. However, the molecular mechanisms of this pathway and its potential for clinical application remain unknown. In this study, we found that PI4KIIα could be an ideal combinatorial target for EGFR treatment via regulating EGFR degradation. Results showed that PI4KIIα knockdown reduced EGFR protein level, and the expression of PI4KIIα shows a strong correlation with EGFR in human breast cancer tissues (r = 0.77, P < 0.01). PI4KIIα knockdown greatly prolonged the effects and decreased the effective dosage of AG-1478, a specific inhibitor of EGFR. In addition, it significantly enhanced AG1478-induced inhibition of tumor cell survival and strengthened the effect of the EGFR-targeting anti-cancer drug Iressa in xenograft tumor models. Mechanistically, we found that PI4KIIα suppression increased EGFR ligand-independent degradation. Quantitative proteomic analysis by stable isotope labeling with amino acids in cell culture (SILAC) and LC-MS/MS suggested that HSP90 mediated the effect of PI4KIIα on EGFR. Furthermore, we found that combined inhibition of PI4KIIα and EGFR suppressed both PI3K/AKT and MAPK/ERK pathways, and resulted in downregulation of multiple oncogenes like PRDX2, FASN, MTA2, ultimately leading to suppression of tumor growth. Therefore, we conclude that combined inhibition of PI4KIIα and EGFR exerts a multiple anti-tumor effect. Dual inhibition of EGFR at protein and activity level via combinatorial blocking of PI4KIIα presents a novel strategy to combat EGFR-dependent tumors.

Drug susceptibility and UL97 gene mutation analysis of cytomegalovirus in recipients of hematopoietic stem cell transplantation / 南方医科大学学报

<p><b>OBJECTIVE</b>To monitor human cytomegalovirus (HCMV) drug resistance in recipients of hematopoietic stem cell transplantation by phenotypic and genotypic methods.</p><p><b>METHODS</b>HCMV clinical isolates was isolated from the urine of hematopoietic stem cell transplantation recipients treated with GCV. Tissue cell infection median dose (TCID50) of the isolates was calculated using Reed-Muench method, and their drug susceptibility was determined by plaque reduction assay. We amplified the UL97 DNA fragment of the virus by nested PCR followed by automated DNA sequencing.</p><p><b>RESULTS</b>HCMV clinical strain isolated from the urine samples of the recipients using a human fibroblast cell line showed a TCID50 value of 10(-4.618)/0.1 ml and a 50% inhibitory concentration (IC50) to GCV of 5.847 µmol/L, suggesting its sensitivity to GCV. Alignment with the AD169 DNA reference sequence identified 4 point mutations of the virus at 1509 (T-C), 1575 (C-T), 1794 (T-C), and 1815 (C-G), and only the last mutation resulted in one amino acid mutation to D605E. No gene mutation was found in relation to GCV resistance.</p><p><b>CONCLUSIONS</b>Phenotypic and genotypic assays were established to examine antiviral drug resistance of HCMV in recipients of hematopoietic stem cell transplantation. We did not find any drug resistance of the clinical HCMV isolate.</p>

Construction and characterization of enterohemorrhagic Escherichia coli O157:H7 ppk- deleted strain / 南方医科大学学报

<p><b>OBJECTIVE</b>To construct enterohemorrhagic Escherichia coli (EHEC) O157: H7 ppk gene deletion strains and study its biological characteristics.</p><p><b>METHODS</b>The gene fragment of kanamycin resistance was amplified using a pair of homologous arm primers whose 5' and 3' ends were homologous with ppk gene and kanamycin resistance gene, respectively. EHEC O157: H7 EDL933w competent strains were prepared and transformed via electroporation with the amplification products. The ppk gene was replaced by kanamycin resistance gene using pKD46-mediated Red recombination system. The recombinant strain was confirmed by PCR and sequencing, and its morphology, growth ability and adhesion were assessed using Gram staining, OD600 value and Giemsa staining.</p><p><b>RESULTS AND CONCLUSION</b>We established a ppk-deleted EHEC O157:H7 EDL933w strain with kanamycin resistance and compared the biological characteristics of the wild-type and mutant strains, which may facilitate further study of the regulatory mechanism of ppk gene.</p>

Effects of overexpression of NADH kinase gene on ethanol fermentation by Saccharomyces cerevisiae / 生物工程学报

Glycerol is the main byproduct in ethanol production by Saccharomyces cerevisiae. In order to improve ethanol yield and the substrate conversion, a cassette about 4.5 kb for gene homologous recombination, gpd2Δ::PGK1(PT)-POS5-HyBR, was constructed and transformed into the haploid strain S. cerevisiae S1 (MATa) to replace the GPD2 gene by POS5 gene. The NADH kinase gene POS5 was successfully over expressed in the recombinant strain S. cerevisiae S3. Comparing with the parent strain, the recombinant strain S. cerevisiae S3 exhibited an 8% increase in ethanol production and a 33.64% decrease in glycerol production in the conical flask fermentation with an initiatory glucose concentration of 150 g/L. Overexpression of NADH kinase gene seems effective in reducing glycerol production and increasing ethanol yield.

Sodium butyrate induces apoptosis of human colon cancer cells by modulating ERK and sphingosine kinase 2 / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate the role of extracellular signal-regulated kinase (ERK) in apoptosis of human colon cancer (HCT116) cells.</p><p><b>METHODS</b>After the HCT116 cells were pretreated with specific ERK inhibitor (U0126) or specific siRNA and exposed to 10 mmol/L sodium butyrate (NaBT) for 24 h, their apoptosis was detected by flow cytometry, levels of SphK2 and ERK protein were measured by Western blot, and translocation of SphK2 was assayed by immunofluorescence microscopy.</p><p><b>RESULTS</b>The U0126 and siRNAs specific for SphK2 blocked the export of SphK2 from nuclei to cytoplasm and increased the apoptosis of HCT116 cells following NaBT exposure. Over-expression of PKD decreased NaBT-induced apoptosis of HCT116 cells, which was reversed by U0126. Furthermore, transfection of HCT116 cells with constitutively activated PKD plasmids recovered the U0126-blocked export of SphK2.</p><p><b>CONCLUSION</b>ERK regulates the export of SphK2 and apoptosis of HCT116 cells by modulating PKD. Modulation of these molecules may help increase the sensitivity of colon cancer cells to the physiologic anti-colon cancer agent, NaBT.</p>

Sphingosine Kinase-1/sphingosine 1-phosphate pathway in diabetic nephropathy / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>Diabetic nephropathy (DN) is the major cause of end-stage renal disease worldwide and its prevalence continues to increase. Currently, therapies for DN provide only partial renoprotection; hence new targets for therapeutic intervention need to be identified. In this review, we summarized the new target, sphingosine kinase-1/sphingosine 1-phosphate (SphK1/S1P) pathway, explored its potential therapeutic role in the prevention and treatment of DN.</p><p><b>DATA SOURCES</b>Most relevant articles were mainly identified by searching PubMed in English.</p><p><b>STUDY SELECTION</b>Mainly original articles and critical review articles by major pioneer investigators in this field were selected to be reviewed.</p><p><b>RESULTS</b>SphK1/S1P pathway can be activated by hyperglycemia, advanced glycation end products, and many pro-inflammatory cytokines, which leads to fibronectin, transforming growth factor-β1 up-regulation and AP-1 activation. And then it could promote glomerular mesangial cells proliferation and extracellular matrix accumulation, mediating the initiation and progression of diabetic renal fibrosis.</p><p><b>CONCLUSIONS</b>SphK1/S1P pathway is closely correlated with the pathogenesis of DN. The results suggest that SphK1/S1P pathway as a new target for clinically improving DN in future is of great prospect.</p>

Inhibitions of SphK1 inhibitor SKI II on cell cycle progression and cell invasion of hepatoma HepG2 cells / 药学学报

Sphingosine kinase 1 (SphK1) plays critical roles in cell biological functions. Here we investigated the effects of SphK1 inhibitor SKI II on hepatoma HepG2 cell cycle progression and invasion. Cell survival was determined by SRB assay, cell cycle progression was assayed by flow cytometry, the ability of cell invasion was measured by Matrigel-Transwell assay and protein expression was detected by Western blotting. The results showed that SKI II markedly inhibited HepG2 cell survival in a dose-dependent manner, induced G1 phase arrest in HepG2 cell and inhibited cell invasion. SKI II markedly decreased the expressions of G1-phase-related proteins CDK2, CDK4 and Cdc2 and the levels of cell invasion-associated proteins MMP2 and MMP9. The results showed that SKI II inhibited cell cycle progression and cell invasion, implying SphK1 as a potential target for hepatoma treatment.