Síndrome de Morquio, una afección infrecuente / Morquio syndrome, a rare condition

Introducción: el síndrome de Morquio es una rara enfermedad hereditaria autosómica recesiva, caracterizada por la presencia de un trastorno del metabolismo de los glúcidos, generando dismi- nución de la calidad de vida. Caso clínico: recién nacido a término de 37.6 semanas con APGAR 7-9, que minutos después de nacido muestra signos de cianosis distal y bucal, acompañado de disminución en la saturación de oxígeno al 70%. Posteriormente, se identificaron características fenotípicas y manifestaciones clínicas que permitieron la sospecha diagnóstica de esta enferme- dad, lo que se corroboró mediante estudio genético. Conclusiones: El diagnóstico de síndrome de Morquio se logró establecer en los primeros momentos del nacimiento, las manifestaciones observadas en el caso que se presenta fueron las clásicas que informa la literatura médica, el estudio genético confirmó el diagnóstico.

Introduction: Morquio syndrome is a rare autosomal recessive hereditary disease, characterized by the presence of a carbohydrate metabolism disorder, generating a decrease in the quality of life. Clinical case: newborn of 37.6 weeks with APGAR 7-9, who shows signs of distal and oral cyanosis, accompanied by a decrease in oxygen saturation to 70% minutes after birth. Subse- quently, the diagnostic suspicion of this disease was identified due to the phenotypic characteris- tics and clinical manifestations, which was corroborated by genetic study. Conclusions: The diagnosis of Morquio syndrome was established in the first moments of birth, the manifestations observed in the case presented were the classic ones reported in the medical literature, the gene- tic study confirmed the diagnosis

Epigenetic Reader BRD4 (Bromodomain-Containing Protein 4) Governs Nucleus-Encoded Mitochondrial Transcriptome to Regulate Cardiac Function.

BACKGROUND: BET (bromodomain and extraterminal) epigenetic reader proteins, in particular BRD4 (bromodomain-containing protein 4), have emerged as potential therapeutic targets in a number of pathological conditions, including cancer and cardiovascular disease. Small-molecule BET protein inhibitors such as JQ1 have demonstrated efficacy in reversing cardiac hypertrophy and heart failure in preclinical models. Yet, genetic studies elucidating the biology of BET proteins in the heart have not been conducted to validate pharmacological findings and to unveil potential pharmacological side effects. METHODS: By engineering a cardiomyocyte-specific BRD4 knockout mouse, we investigated the role of BRD4 in cardiac pathophysiology. We performed functional, transcriptomic, and mitochondrial analyses to evaluate BRD4 function in developing and mature hearts. RESULTS: Unlike pharmacological inhibition, loss of BRD4 protein triggered progressive declines in myocardial function, culminating in dilated cardiomyopathy. Transcriptome analysis of BRD4 knockout mouse heart tissue identified early and specific disruption of genes essential to mitochondrial energy production and homeostasis. Functional analysis of isolated mitochondria from these hearts confirmed that BRD4 ablation triggered significant changes in mitochondrial electron transport chain protein expression and activity. Computational analysis identified candidate transcription factors participating in the BRD4-regulated transcriptome. In particular, estrogen-related receptor α, a key nuclear receptor in metabolic gene regulation, was enriched in promoters of BRD4-regulated mitochondrial genes. CONCLUSIONS: In aggregate, we describe a previously unrecognized role for BRD4 in regulating cardiomyocyte mitochondrial homeostasis, observing that its function is indispensable to the maintenance of normal cardiac function.

Genomic Binding Patterns of Forkhead Box Protein O1 Reveal Its Unique Role in Cardiac Hypertrophy.

BACKGROUND: Cardiac hypertrophic growth is mediated by robust changes in gene expression and changes that underlie the increase in cardiomyocyte size. The former is regulated by RNA polymerase II (pol II) de novo recruitment or loss; the latter involves incremental increases in the transcriptional elongation activity of pol II that is preassembled at the transcription start site. The differential regulation of these distinct processes by transcription factors remains unknown. Forkhead box protein O1 (FoxO1) is an insulin-sensitive transcription factor that is also regulated by hypertrophic stimuli in the heart. However, the scope of its gene regulation remains unexplored. METHODS: To address this, we performed FoxO1 chromatin immunoprecipitation-deep sequencing in mouse hearts after 7 days of isoproterenol injections (3 mg·kg-1·mg-1), transverse aortic constriction, or vehicle injection/sham surgery. RESULTS: Our data demonstrate increases in FoxO1 chromatin binding during cardiac hypertrophic growth, which positively correlate with extent of hypertrophy. To assess the role of FoxO1 on pol II dynamics and gene expression, the FoxO1 chromatin immunoprecipitation-deep sequencing results were aligned with those of pol II chromatin immunoprecipitation-deep sequencing across the chromosomal coordinates of sham- or transverse aortic constriction-operated mouse hearts. This uncovered that FoxO1 binds to the promoters of 60% of cardiac-expressed genes at baseline and 91% after transverse aortic constriction. FoxO1 binding is increased in genes regulated by pol II de novo recruitment, loss, or pause-release. In vitro, endothelin-1- and, in vivo, pressure overload-induced cardiomyocyte hypertrophic growth is prevented with FoxO1 knockdown or deletion, which was accompanied by reductions in inducible genes, including Comtd1 in vitro and Fstl1 and Uck2 in vivo. CONCLUSIONS: Together, our data suggest that FoxO1 may mediate cardiac hypertrophic growth via regulation of pol II de novo recruitment and pause-release; the latter represents the majority (59%) of FoxO1-bound, pol II-regulated genes after pressure overload. These findings demonstrate the breadth of transcriptional regulation by FoxO1 during cardiac hypertrophy, information that is essential for its therapeutic targeting.

Role of CRTC2 in Metabolic Homeostasis: Key Regulator of Whole-Body Energy Metabolism?

Cyclic adenosine monophosphate (cAMP) signaling is critical for regulating metabolic homeostasis in mammals. In particular, transcriptional regulation by cAMP response element-binding protein (CREB) and its coactivator, CREB-regulated transcription coactivator (CRTC), is essential for controlling the expression of critical enzymes in the metabolic process, leading to more chronic changes in metabolic flux. Among the CRTC isoforms, CRTC2 is predominantly expressed in peripheral tissues and has been shown to be associated with various metabolic pathways in tissue-specific manners. While initial reports showed the physiological role of CRTC2 in regulating gluconeogenesis in the liver, recent studies have further delineated the role of this transcriptional coactivator in the regulation of glucose and lipid metabolism in various tissues, including the liver, pancreatic islets, endocrine tissues of the small intestines, and adipose tissues. In this review, we discuss recent studies that have utilized knockout mouse models to delineate the role of CRTC2 in the regulation of metabolic homeostasis.

A Glycine Riboswitch in Streptococcus pyogenes Controls Expression of a Sodium:Alanine Symporter Family Protein Gene.

Regulatory RNAs play important roles in the control of bacterial gene expression. In this study, we investigated gene expression regulation by a putative glycine riboswitch located in the 5'-untranslated region of a sodium:alanine symporter family (SAF) protein gene in the group A Streptococcus pyogenes serotype M49 strain 591. Glycine-dependent gene expression mediated by riboswitch activity was studied using a luciferase reporter gene system. Maximal reporter gene expression was observed in the absence of glycine and in the presence of low glycine concentrations. Differences in glycine-dependent gene expression were not based on differential promoter activity. Expression of the SAF protein gene and the downstream putative cation efflux protein gene was investigated in wild-type bacteria by RT-qPCR transcript analyses. During growth in the presence of glycine (≥1 mM), expression of the genes were downregulated. Northern blot analyses revealed premature transcription termination in the presence of high glycine concentrations. Growth in the presence of 0.1 mM glycine led to the production of a full-length transcript. Furthermore, stability of the SAF protein gene transcript was drastically reduced in the presence of glycine. We conclude that the putative glycine riboswitch in S. pyogenes serotype M49 strain 591 represses expression of the SAF protein gene and the downstream putative cation efflux protein gene in the presence of high glycine concentrations. Sequence and secondary structure comparisons indicated that the streptococcal riboswitch belongs to the class of tandem aptamer glycine riboswitches.

[The specific cytotoxicities of chimeric antigen receptor-engineered T cells on different lymphomas].

Objective: To investigate the specific cytotoxicities of the second and third generations of chimeric antigen receptor (CAR) -engineered T cells (CAR-T) on different lymphomas. Methods: CAR-Ts were prepared by lentivirus packaging and infection of T cells. CCK-8, ELISA and Lactate dehydrogenase cytotoxicity assay were applied to detect the proliferation capacity, the secretion level of inflammatory factor and the specific cytotoxicity. Flow cytometry assay showed the specific cytotoxicity and residual level of CAR-T in lymphomas of treated mice. Results: The results showed that the third generation CAR-T had greater capacity of the specific cytotoxicity and proliferation capacity than of the second generation CAR-T. But there was no prominent change of the secretion level of inflammatory factor. The specific cytotoxicity of the second generation CAR-T on highly aggressive lymphomas Raji was more prominent than in inert EHEB, but also could achieve satisfactory effect. The tumor burden in the mice injected with Raji was lower than in the mice injected with EHEB from nude mice experiment. But the residual level of CAR-T in the EHEB-injected mice was higher than in the Raji-injected ones. So the second generation CAR-T was more suitable for the treatment of indolent lymphoma. Conclusion: The second generation CD19 CAR-T could treat aggressive lymphoma in a relatively short period, while the second generation CD19 CAR-T need a longer time in vivo to achieve satisfactory curative effect on the noble lymphoma.

Regulação gênica da via ampk pelo exercício físico: revisão sistemática e análise in silico / Ampk pathway gene regulation by physical exercise: systematic review and in silico analysis / Regulación génica de la vía ampk por el ejercicio físico: revisión sistemática y análisis in silico

RESUMO Introdução: Novos estudos de regulação gênica do exercício físico por meio de técnicas pós-genômicas em ensaios de resistência (endurance) e força caracterizam a transcriptômica do exercício físico. Entre os genes afetados, destacamos a via da proteína quinase ativada por AMP (AMPK), cuja ativação ocorre durante o exercício como resultado das alterações dos níveis de fosfato energético da fibra muscular. Objetivo: Avaliar a via de sinalização da AMPK por revisão sistemática da expressão de genes e análise in silico. Método: Foi efetuada uma revisão sistemática para avaliar a regulação gênica da via de sinalização AMPK, caracterizando os genes estudados na literatura, as variações de regulação obtidas, na forma de fold change e tipos de exercício usados. Resultados: A via de sinalização AMPK mostrou 133 genes no repositório KEGG (Kyoto Encyclopedia of Genes and Genomes), os quais foram confrontados com a revisão sistemática da literatura, totalizando 65 genes. Dezessete genes apresentaram UR e 24 mostraram DR com relação ao seu respectivo controle. Além destes, 20 genes estavam presentes nos trabalhos, apresentando tanto UR e DR e quatro genes não apresentaram dados de regulação. Verificou-se regulação específica em função do tipo de exercício efetuado. Discussão: Dos 133 genes da via AMPK, 48,8% foram amostrados nos trabalhos revisados, indicando que uma parte significativa da via é regulada pelo exercício. O estudo apresentou a regulação gênica básica de dois mecanismos para a recuperação energética, a biogênese mitocondrial e o bloqueio da gliconeogênese. Conclusão: Este trabalho mostrou que o exercício atua ativamente na via de sinalização da AMPK, na importância da regulação via PGC-1α e no papel de outros genes, regulando a expressão de mais da metade dos genes amostrados.

ABSTRACT Introduction: New studies of gene regulation by physical exercise through post-genomic techniques in endurance and strength tests characterize the physical exercise transcriptomics. Among the affected genes, we highlight the AMP-activated protein kinase (AMPK) pathway, the activation of which occurs during exercise because of changes in muscle fiber energetic phosphate levels. Objective: To evaluate the AMPK signaling pathway by systematic review of gene expression and in silico analysis. Method: A systematic review was performed in order to assess the gene regulation of AMPK signaling pathway, characterizing the genes studied in the literature, regulation variations obtained in the form of fold change, and types of exercise performed. Results: The AMPK signaling pathway showed 133 genes in the KEGG repository (Kyoto Encyclopedia of Genes and Genomes), which were compared with the systematic review of the literature, totaling 65 genes. Seventeen genes presented UR and 24 showed DR in relation to their respective control. In addition to these, 20 genes were present in the literature, presenting both UR and DR and four genes showed no regulatory data. Specific regulation was verified according to the type of exercises performed. Discussion: Of the 133 genes of the AMPK pathway, 48.8% were sampled in the revised studies indicating that a significant part of the pathway is regulated by exercise. The study presented the basic gene regulation of two mechanisms for energy recovery, mitochondrial biogenesis, and gluconeogenesis blockade. Conclusion: This work showed that the exercise actively works in the AMPK signaling pathway, in the importance of regulation via PGC-1α and in the role of other genes, regulating the expression of more than half of the genes sampled.

RESUMEN Introducción: Nuevos estudios de regulación génica del ejercicio físico por medio de técnicas pos-genómicas en ensayos de resistencia (endurance) y fuerza caracterizan la transcriptómica del ejercicio físico. Entre los genes afectados, destacamos la vía de la proteína quinasa activada por AMP (AMPK), cuya activación ocurre durante el ejercicio como resultado de las alteraciones de los niveles de fosfato energético de la fibra muscular. Objetivo: Evaluar la vía de señalización AMPK por revisión sistemática de la expresión de genes y análisis in silico. Método: Se ha efectuado una revisión para evaluar la regulación génica de la vía de señalización AMPK, caracterizando los genes estudiados en la literatura, las variaciones de regulación obtenidas en forma de fold change y tipos de ejercicios utilizados. Resultados: La vía de señalización AMPK mostró 133 genes en el repositorio KEGG (Kyoto Encyclopedia of Genes and Genomes), los cuales fueran confrontados con la revisión sistemática de la literatura, totalizando 65 genes. Diecisiete genes presentaron UR y 24 mostraron DR con respecto a su respectivo control. Además de estos, 20 genes estaban presentes en los trabajos, presentando tanto UR y DR y cuatro genes no presentaron dados de regulación. Se observó una regulación específica en función del tipo de ejercicio efectuado. Discusión: De los 133 genes de la vía AMPK, 48,8% fueron muestreados en los trabajos revisados, indicando que una parte significativa de la vía es regulada por el ejercicio. El estudio presentó la regulación génica básica de dos mecanismos para la recuperación energética, la biogénesis mitocondrial y el bloqueo de la gluconeogénesis. Conclusión: Este trabajo mostró que el ejercicio actúa activamente en la vía de señalización AMPK, en la importancia de la regulación vía factor PGC-1a y en el papel de otros genes, regulando la expresión de más de la mitad de los genes muestreados.

The specific cytotoxicities of chimeric antigen receptor-engineered T cells on different lymphomas / 中华血液学杂志

Objective@#To investigate the specific cytotoxicities of the second and third generations of chimeric antigen receptor (CAR) -engineered T cells (CAR-T) on different lymphomas.@*Methods@#CAR-Ts were prepared by lentivirus packaging and infection of T cells. CCK-8, ELISA and Lactate dehydrogenase cytotoxicity assay were applied to detect the proliferation capacity, the secretion level of inflammatory factor and the specific cytotoxicity. Flow cytometry assay showed the specific cytotoxicity and residual level of CAR-T in lymphomas of treated mice.@*Results@#The results showed that the third generation CAR-T had greater capacity of the specific cytotoxicity and proliferation capacity than of the second generation CAR-T. But there was no prominent change of the secretion level of inflammatory factor. The specific cytotoxicity of the second generation CAR-T on highly aggressive lymphomas Raji was more prominent than in inert EHEB, but also could achieve satisfactory effect. The tumor burden in the mice injected with Raji was lower than in the mice injected with EHEB from nude mice experiment. But the residual level of CAR-T in the EHEB-injected mice was higher than in the Raji-injected ones. So the second generation CAR-T was more suitable for the treatment of indolent lymphoma.@*Conclusion@#The second generation CD19 CAR-T could treat aggressive lymphoma in a relatively short period, while the second generation CD19 CAR-T need a longer time in vivo to achieve satisfactory curative effect on the noble lymphoma.

Influence of interaction between endogenous miRNAs and hepatitis B virus in hepatocytes on hepatitis B virus transcription and related mechanisms / 临床肝胆病杂志

MicroRNAs (miRNAs) may be involved in the regulation of gene expression after transcription and play important roles in regulating hepatitis B virus (HBV) transcription and replication. This article summarizes the miRNAs with an anti-HBV effect in hepatocytes and 4 regulatory mechanisms, as well as the mechanisms through which HBV affects the expression of endogenous miRNAs in hepatocytes via HBx and self-coding miRNAs and promotes replication. The analyses show that the interaction between endogenous miRNAs and HBV in hepatocytes forms a complex regulatory network, competes for the results of regulation, and determines the activity of HBV transcription and the trend of disease progression. In-depth studies on the mechanisms of the influence of interaction between endogenous miRNA and HBV in hepatocytes on HBV transcription have great significance in exploring new anti-HBV methods.

Effect of aging on transcription and protein expressions of procollagen α polypeptide gene of vascular smooth muscle cells in rat / 中华老年医学杂志

Objective To investigate the effects of aging on procollagen α polypeptide gene transcription and protein expression in rat vascular smooth muscle cells.Methods Vascular smooth muscle cells from thoracoabdominal aorta in neonate and 9 months old healthy Wistar rats were cultured in vitro.Results Transcription polymerase chain reaction(RT PCR) and Western blotting were used to detect type Ⅰ and Ⅲ pro-collagen α polypeptide mRNA and protein.The RT-PCR displayed that type Ⅰ procollagen α polypeptide mRNA expression had no significant difference between young group and adult group [(76.62±1.05) vs.(78.37±2.42),P＞0.05].Type Ⅲ procollagen α polypeptide mRNA expression was (105.40 ± 2.66) in young group and (123.10 ± 3.81) in adult group(P＞0.05).Type Ⅰ procollagen α polypeptide mRNA expression was (3.13 ±0.54) in young group and (4.63 ± 1.03) in adult group (P=0.05).Type Ⅲ procollagen α polypeptide mRNA expression had no significant difference between the adult and young groups[(6.86 ±0.41) vs.(7.68±0.63),P＞0.05].Type Ⅰ and type Ⅲ procollagen α polypeptide protein expressions were increased significantly in adult group as compared with the young group [(0.10 ± 0.03) vs.(0.06±0.03),(0.58±0.06) vs.(0.40±0.02),both P＜0.05].Conclusions Aging increases the procollagen α polypeptide level in vascular smooth muscle cell,which may involve in the development of vascular remodeling and atherosclerosis.

The role of spinal cord p300 in chronic constriction nerve injury-induced neuropathic pain in rats / 中国医师杂志

Objective To explore the role of spinal cord p300 in neuropathic pain induced by chronic constriction nerve injury (CCI) in rats.Methods Thirty two Sprague-Dawley (SD) rats were randomly divided into sham and CCI groups,14 days after surgery,immuno-fluorescence staining and Western blot were used to detect distribution and expression of p300 protein.After rats were successfully implanted with an intrathecal catheter and accepted CCI surgery,another 24 rats were randomly divided into three groups (n =8):dimethyl sulfoxide (DMSO) group,p300 acetyltransferase inhibitor C646 group,and control C37 group.Each rat were administered through the intrathecal catheter from day 7 to 14 and mechanical withdraw threshold were tested.Results (1) The p300 positive cells were detected mainly in neurons,and p300 protein in spinal cord of CCI group were significantly higher than sham group (P ＜0.05).(2) C646 alleviated significantly neuropathic pain in rats,without significant changes in pain threshold after injection of C37 and DMSO.Conclusions The p300 protein in spinal cord was involved in the development of neuropathic pain in rats,the mechanism may be referred to its acetyltransferase activity.

Baicalin Promotes the Neuronal Differentiation of Neural Stem Cells through Downregulating the p-STAT3 / 天津医药

Objective To observe the role of baicalin on the expression of phosphorylated protein of signal transduc-ers and activators of transcription signaling proteins (STATs) during the process that neural stem cells (NSCs) differentiating into neurons. Methods NSCs were isolated from the embryonic cerebral cortex of the 14-15-day pregnant SD rats, which were cultured and passaged in vitro. The 3rd generation of NSCs was used in the experiment. NSCs were randomized into nat-ural differentiation control group, three different doses of baicalin groups (7.5μmol/L, 15μmol/L and 30μmol/L), leukemia inhibitory factor (LIF)+basic fibroblast growth factor (bFGF) group and baicalin+LIF+bFGF group. After 6 d culture in vi-tro, the immunohistochemical method was used to observe the expressions of microtubule-associated protein 2(MAP-2) and glial fibrillary acidic protein (GFAP) in different groups. The expression levels of phosphorylation protein of STAT 3 in NSCs were detected by Western blotting method after 2 h and 6 d of culture. Results The expression of MAP-2 in NSCs was in-creased by baicalin, but the expression of GFAP in NSCs decreased. The expression of GFAP in NSCs was enhanced in LIF+bFGF group, which was inhibited by baicalin+LIF+bFGF. The phosphorylation level of STAT3 in NSCs was downregulat-ed by baicalin, but the phosphorylation level of STAT3 was upregulated in LIF+bFGF group. The upregulated phosphoryla-tion level of STAT3 was inhibited in baicalin+LIF+bFGF group(P＜0.05). Conclusion Baicalin can induce NSCs to dif-ferentiate into neurons, which may be caused by the downregulation of the phosphorylation level of STAT3 in NSCs.

Construction of human surfactant protein B promoter luciferase reporter gene vectors and detection of their activities / 中国医师杂志

Objective To construct human surfactant protein B (SP-B) gene promoter luciferase reporter plasmids and detect their transcriptional activities in H441 cells.Methods (1)The fragment of SP-B promoter (-218/+ 435 bp) was acquired from human genome DNA by polymerase chain reaction (PCR) amplification and then was inserted into pGM-T vector by the T4 DNA ligase.The vector was transfected into TOP10 E.coli.The positive clone was identified by DNA sequencing.The identified target SP-B promoter sequence was cloned into pGL3-basic vector to construct the recombinant vector pGL3-basic-SP-B-promoter and was identified by enzyme digestion and sequencing; (2)The pGL3-basic-SP-B-promoter vector was converted into pGL4.17-SP-B-promoter vector through enzyme digestion.The identified recombinant vectors and control plasmid pRL-TK were transfected into H441 cells by lipofectamine 2000,and luciferase assays was performed using the dual-luciferase reporter assay system.Results The sequences of SP-B promoter in the recombinant luciferase reporter plasmids were consistent with the one published on Genebank.The firefly/renilla luciferase activity ratio of pGL3-basic/pGL4.17-SP-B-promoter vector (2.8 ± 1.1,66.5±3.8) was significantly higher than pGL3-Basic,pGL4.17 control vector (0.2 ±0.1,4.3 ±0.4) with statistical significance (t =4.182,27.419,P =0.000),respectively.The SP-B promoter activity of pGL4.17-SP-B-promoter vector was significantly higher than pGL3-basic-SP-B-promoter vector (t =27.712,P =0.000).Conclusions The pGL3-basic/pGL4.17-SP-B-promoter vectors are successfully constructed with SP-B promoter activity in H441 cells and pGL4.17-SP-B-promoter vector is the better choice for further study with higher luciferase activity.

Effects of sodium arsenite on hypermethylation, transcription and expression of O6-methylguanine-DNA methyltransferase gene in HaCaT cells / 中国地方病学杂志

Objective To investigate the DNA methylation feature and DNA methylation regulation to its transcription and expression of O6-methylguanine-DNA methyltransferase gene (MGMT) in NaAsO2-treated HaCaT cells. Methods HaCaT cells were treated 72 hours at intervals and repeatedly by 3.13, 6.25,12.50, and 25.00 μmol/L NaAsO2, MGMT gene promoter region was amplified in the transcription initiation site - 329 - + 93 region by bisulfate-sequencing polymerase chain reaction (BSP), the mRNA transcription and the protein expression of MGMT was detected by real-time quantitative PCR and Western blotting. NaAsO2-untreated HaCaT cell was set as a blank control, and human epidermal squamous carcinoma cell strain A431 was set as a positive control. Results Among the groups of HaCaT cells treated with 3.13, 6.25, 12.50 and 25.00 μmol/L NaAsO2, the positive rates of the DNA methylation of promoter region in MGMT gene were 0.63%(l/160), 6.25% (10/160), 10.63%( 17/160) and 18.75% (30/160), respectively, and methylated CpG sites were mainly located in - 249--146 region relative to transcription start site. There was no DNA methylation in the blank control. There were significant differences between the blank control and the NaAsO2-treated cells (x2 = 76.687, P< 0.05). Average levels of MGMT mRNA were 1.518 31 ± 0.180 54, 1.425 22 ± 0.180 39, 1.014 54 ± 0.096 79 and 0.887 72 ± 0.020 00, respectively among the groups of HaCaT cells treated with 3.13, 6.25, 12.50 and 25.00 μmol/L NaAsO2, compared with the blank control cells(1.198 29 ± 0.159 97), there were significant differences(F = 37.359, P < 0.05). Average levels of MGMT protein were 1.174 47 ± 0.064 75, 0.848 83 ± 0.057 01, 0.471 63 ± 0.023 34 and 0.240 34 ± 0.014 43, respectively among the groups of HaCaT cells treated with 3.13, 6.25, 12.50 and 25.00 μmol/L NaAsO2, compared with the blank control cells (1.066 19 ± 0.061 24), there were significant differences(F = 20.687, P < 0.05). Conclusions Arsenic can cause CpC island hypermethylation in the promoter region of MGMT gene, which results in inhibited MGMT mRNA transcription and protein expression. It might be one of the important mechanisms of arsenic-induced skin lesion.

Regulatory effects of 3 kinds of antifibrotic cytokines an activity of transforming growth factor-β1 gene promoter / 第二军医大学学报

Objective: To study the regulatory effects of antifibrotic cytokines, interleukin 10 (IL-10), hepatocyte growth factor (HGF), and interferon-gamma (IFN-γ) on activity of TGF-β1 gene promoter, so as to assess the antifibrotic mechanism of cytokines. Methods: Sequence - 1328-+812 of TGF-β1 gene, which contains the - 509 C>T polymorphism, was selected as putative promoter. The recombinant constructions containing - 1328-+ 812 of TGF-β1 gene and CAT reporter gene (phTGF2. 14T, phTGF2. 14C) were constructed and transfected into HepG2 cells with liposomal transfection method, then the transfected HepG2 cells were treated with IL-10(4 ng/ml), HGF(10 ng/ml) or IFN-γ(20 ng/ml). Reporter gene activity was analyzed by ELISA. Results: Reporter gene activity in cells transfected with phTGF2. 14C was significantly higher than those transfected with phTGF2. 14T (P<0.01). IFN-γ significantly inhibited the reporter gene activity in HepG2 cells transfected with phTGF2. 14C or phTGF2. 14T(P<0.05); HGF significantly increased the reporter gene activity in cells transfected with phTGF2. 14C (P<0.05). IL-10 had no effects on the activities of cells transfected with phTGF2. 14C or phTGF2.14T. Conclusion: C allele at - 509 can increase the promoter activity of TGF-β1 gene in HepG2 cells. The antifibrotic effect of IFN-γ might be related to its inhibitory effect on the putative promoter activity of TGF-β 1 gene; the antifibrotic effects of HGF and IL-10 may not be through regulation of TGF-beta1 gene transcription.

ATM modulates transcription in response to histone deacetylase inhibition as part of its DNA damage response

Chromatin structure has a crucial role in a diversity of physiological processes, including development, differentiation and stress responses, via regulation of transcription, DNA replication and DNA damage repair. Histone deacetylase (HDAC) inhibitors regulate chromatin structure and activate the DNA damage checkpoint pathway involving Ataxia-telangiectasia mutated (ATM). Herein, we investigated the impact of histone acetylation/deacetylation modification on the ATM-mediated transcriptional modulation to provide a better understanding of the transcriptional function of ATM. The prototype HDAC inhibitor trichostain A (TSA) reprograms expression of the myeloid cell leukemia-1 (MCL1) and Gadd45alpha genes via the ATM-mediated signal pathway. Transcription of MCL1 and Gadd45alpha is enhanced following TSA treatment in ATM+ cells, but not in isogenic ATM- or kinase-dead ATM expressing cells, in the ATM-activated E2F1 or BRCA1-dependent manner, respectively. These findings suggest that ATM and its kinase activity are essential for the TSA-induced regulation of gene expression. In summary, ATM controls the transcriptional upregulation of MCL1 and Gadd45alpha through the activation of the ATM-mediated signal pathway in response to HDAC inhibition. These findings are important in helping to design combinatory treatment schedules for anticancer radio- or chemo-therapy with HDAC inhibitors.

Early growth response protein 1 acts as an activator of SOX18 promoter

Sex-determining region Y box 18 (Sox18/SOX18) gene is an important regulator of vascular development playing a role in endothelial cell specification or differentiation, angiogenesis and atherogenesis. The aim of this study was to perform comprehensive functional characterization of the human SOX18 promoter, including determination of transcription start point (tsp) and identification of control elements involved in the regulation of SOX18 gene expression, with an emphasis on angiogenesis-related transcription factors. Analyses were performed in HeLa cells, representing a tumor cell line, and in EA.hy926 cells used as an endothelial model system. We have determined unique tsp of SOX18 gene, located 172 nucleotides upstream from ATG codon. Further, we have shown that SOX18 promoter region, -726 to -89 bp relative to tsp, contains positive cis-regulatory element(s) that stimulates SOX18 promoter activity, while region -89 to + 166 represents the minimal promoter. Within this region we have recognized the presence of essential element(s), positioned from -89 to +29, which harbors cluster of three putative early growth response 1 (EGR1) binding sites. By in vitro binding assays and functional analyses we have shown that these three putative binding sites are functionally relevant and sufficient for EGR1-induced SOX18 transcription. Mutations of these binding sites significantly impaired activity of the SOX18 promoter, particularly in EA.hy926 cells, indicating the importance of these regulatory elements for SOX18 promoter activity in endothelial setting. By data presented in this study, we have established SOX18 as a novel target gene regulated by EGR1 transcription factor, thus providing the first functional link between two transcription factors previously shown to be involved in the control of angiogenesis.