Efecto de la inhibición de la proteína símil angiopoyetina tipo 3 (ANGPTL3): utilidad para el tratamiento de las dislipemias graves / Angiopoietin-like type 3 (angptl) inhibition: its role in the treatment of severe dyslipidemia

Las variantes de ANGPTL3 con pérdida de función están asociadas con efectos beneficiosos sobre el metabolismo lipídico y de carbohidratos y con riesgo reducido de enfermedad coronaria. Los cambios beneficiosos en los parámetros lipídicos que se obtienen con la inhibición de ANGPTL3 junto con la reducción en aterosclerosis que se observa en modelos animales y en estudios epidemiológicos de genética humana hacen de ANGPTL3 un nuevo objetivo terapéutico para prevenir las enfermedades cardiovasculares. Dos estrategias novedosas han surgido para inhibir esta proteína: un anticuerpo monoclonal y un oligonucleótido antisentido, con capacidad para reducir tanto el colesterol como los triglicéridos plasmáticos en forma notoria. Aunque el horizonte es promisorio, todavía no sabemos si los efectos de una variante presente desde el comienzo de la vida serán reproducidos por la inhibición de esta proteína que se realiza más tarde en la vida a través de una intervención farmacológica. (AU)

Loss-of-function ANGPTL3 variants are associated with beneficial effects on carbohydrate and lipid metabolism, and reduced risk of coronary heart disease. The beneficial changes in lipid parameters obtained by ANGPTL3 inhibition together with atheroprotection observed in animal models and in epi-demiological studies of human genetics make ANGPTL3 a new therapeutic target to prevent cardiovascular diseases. Two novel strategies have emerged to inhibit this protein: a monoclonal antibody and an antisense oligonucleotide, with the ability to significantly lower plasma cholesterol and triglycerides. Although the horizon is promising, we still do not know if the effects of a variant present from the beginning of life will be reproduced by the inhibition of this protein that takes place later in life through a pharmacological intervention. (AU)

Effect of Super-Oxidized Water, Sodium Hypochlorite and EDTA on Dentin Microhardness

The present study aimed to evaluate the influence of the following irrigating solutions on the microhardness of root canal dentin: 2% sodium hypochlorite (2NaOCl), 5% sodium hypochlorite (5NaOCl), super-oxidized water (400 ppm Sterilox - Sx) and 17% EDTA (E). Eighty roots from bovine incisors were randomly divided into 8 groups (n=10): 2NaOCl, 5NaOCl, Sx, and 2NaOCl + E, 5NaOCl + E, Sx + E (associated with E as final irrigant for 5 min), E solely and distilled water (dH2O) as the negative control. Root canal preparation was performed by hand instruments, using one of the irrigation protocols for 30 min. Then, 5 mm of the cervical root third were cut out from each sample and subjected to the Vickers microhardness test, at two points, one at approximately 500-1000 µm from the root canal lumen (distance 1), and the other at approximately 500-1000 µm from the external root surface (distance 2). Data were analyzed by Wilcoxon and Kruskal-Wallis tests at 5% significance level. Microhardness values at distance 1 were significantly lower than those at distance 2 for all groups, except 5NaOCl and 5NaOCl + E groups (p>0.05). EDTA showed the lowest microhardness values. However, no statistically significant difference was detected among groups at distance 1 and EDTA was significantly different only from Sx at distance 2. In conclusion, all tested solutions showed lower microhardness at the most superficial root canal dentin layer compared to the one found near the external root surface, except 5NaOCl and 5NaOCl + E; EDTA promoted lower microhardness values in comparison to Sterilox at this site.

O presente estudo teve como objetivo avaliar a influência das seguintes soluções irrigadoras na microdureza da dentina do canal radicular: hipoclorito de sódio a 2% (NaOCl2), hipoclorito de sódio a 5% (NaOCl5), água superoxidada (Sterilox(r) 400 ppm - Sx) e EDTA a 17% (E). Oitenta raízes de incisivos bovinos foram divididas aleatoriamente em 8 grupos (n=10): NaOCl2, NaOCl5, Sx e NaOCl2 + E, NaOCl5 + E, Sx + E (associados ao E como irrigante final por 5 min), E isolado e água destilada (H2Od), como controle negativo. O preparo dos canais radiculares foi realizado com instrumentos manuais, usando um dos protocolos de irrigação por 30 min. A seguir, 5 mm do terço cervical de cada amostra foram cortados perpendicularmente e submetidos ao teste de microdureza de Vickers, em dois pontos, um aproximadamente 500-1000 µm da luz do canal radicular (distância 1), e o outro aproximadamente 500-1000 µm da superfície externa da raiz (distância 2). Os dados foram analisados pelos testes de Wilcoxon e Kruskal-Wallis com um nível de significância de 5%. Os valores de microdureza na distância 1 foram significativamente menores do que na distância 2 para todos os grupos, exceto NaOCl5 e NaOCl5 +E (p>0,05). O EDTA mostrou os menores valores de microdureza. No entanto, não foi detectada diferença estatisticamente significativa entre os grupos na distância 1 e o EDTA foi significativamente diferente apenas do Sx na distância 2. Pode-se concluir que todas as soluções testadas mostraram menor microdureza na camada de dentina mais superficial do canal radicular em comparação aos valores encontrados próximo à superfície radicular externa, exceto NaOCl5 e NaOCl5 + E; o EDTA promoveu menor microdureza em comparação ao Sterilox(r) neste ponto.

Inhibitory effect of tissue transglutaminase (tTG) antisense oligodeoxynucleotides on tTG expression in cultured bovine trabecular meshwork cells / 华中科技大学学报（医学）（英德文版）

To study the effect of tTG fully phosphorothioated antisense oligodeoxynucleotides (tTG-ASDON) on tTG expression in cultured bovine trabecular meshwork cells (BTMCs) in vitro and explore a new treatment alternative for primary open angle glaucoma (POAG), the ASDON1 and ASDON2 complementary to the protein codogram region of tTG were designed, synthesized and phosphorothioated according to the secondary structure of tTG. The ASDON1 and ASDON2 were embedded in Lipofectamine and transfected into BTMCs. The untreated group served as negative controls. The expression of tTG in the mRNA and protein level were measured by semi-quantitative RT-PCR and immunohistochemical technique-Supervision method respectively. Our results showed that both the mRNA and the protein of tTG with tTG-ASDON and tTG-ASDON2 were significantly decreased as compared with that of the controls (P < 0.05). On the other hand, no significant difference was found between the ASDON1 group and the ASDON2 group. It is concluded that the expression of tTG mRNA and protein in cultured BTMC are down-regulated by tTG- ASDON. As a result, tTG-ASDON may be used for the treatment of POAG through the inhibitory effect on the expression of tTG.

Co-localization and interaction of organic anion transporter 1 with caveolin-2 in rat kidney

The organic anion transporters (OAT) have recently been identified. Although the some transport properties of OATs in the kidney have been verified, the regulatory mechanisms for OAT's functions are still not fully understood. The rat OAT1 (rOAT1) transports a number of negatively charged organic compounds between the cells and their extracellular milieu. Caveolin (Cav) also plays a role in membrane transport. Therefore, we investigated the protein-protein interactions between rOAT1 and caveolin-2. In the rat kidney, the expressions of rOAT1 mRNA and protein were observed in both the cortex and the outer medulla. With respect to Cav-2, the expressions of mRNA and protein were observed in all portions of the kidney (cortex < outer medulla = inner medulla). The results of Western blot analysis using the isolated caveolae-enriched membrane fractions or the immunoprecipitates by respective antibodies from the rat kidney showed that rOAT1 and Cav-2 co-localized in the same fractions and they formed complexes each other. These results were confirmed by performing confocal microscopy with immunocytochemistry using the primary cultured renal proximal tubular cells. When the synthesized cRNA of rOAT1 along with the antisense oligodeoxynucleotides of Xenopus Cav-2 were co-injected into Xenopus oocytes, the [14C]p-aminohippurate and [3H]methotrexate uptake was slightly, but significantly decreased. The similar results were also observed in rOAT1 over-expressed Chinese hamster ovary cells. These findings suggest that rOAT1 and caveolin-2 are co-expressed in the plasma membrane and rOAT1's function for organic compound transport is upregulated by Cav-2 in the normal physiological condition.

Deoxycholic Acid-Induced Signal Transduction in HT-29 Cells: Role of NF-kappa B and Interleukin-8 / 대한소화기학회지

BACKGROUND/AIMS: Deoxycholic acid (DCA) has been appeared to be an endogenous colon tumor promoter. In this study, we investigated whether DCA induces nuclear factor-kappa B (NF-kappa B) activation and IL-8 expression, and tauroursodeoxycholic acid (TUDC) inhibits this signaling in HT-29 cells. METHODS: After DCA treatments, time courses of NF-kappa B binding activity were determined by electrophoretic mobility shift assay (EMSA). Also, we performed Western blotting of I kappa B alpha to confirm NF-kappa B activation. Time and concentration courses of DCA-induced secretion of IL-8 were measured with ELISA in supernatants of cultured media from the cells. To evaluate the role of NF-kappa B, IL-8 levels were assessed after pretreatment with using phosphorothioate-modified anti-sense oligonucleotides (ODN). Moreover, DCA-induced secretions of IL-8 were measured after pretreatment with TUDC. RESULTS: DCA dose-dependently induced prominent NF-kappa B binding complexes from 30 min to 8 hr and degradation of I kappa B alpha. The secretions of IL-8 were increased with DCA (50~200 micro M) treatment in a time and dose-dependent manner. Pre-incubation of the cells with TUDC (0.1~10 micro M) for 2 hours caused significant decreases in DCA induced IL-8 secretion. However, transient transfection using p50 or p65 AS-ODN showed no effect on IL-8 secretion. CONCLUSIONS: DCA may play as a colonic tumor promoter through anti-apoptotic effect of NF-kappa B activation and IL-8 expression, and DCA-induced NF-kappa B independent IL-8 expression is inhibited by TUDC.

Ventricular myosin light chain-2 gene expression in developing heart of chicken embryos

Recent gene knock-out studies in mice have suggested that ventricular myosin light chain-2 (vMLC2) has a role in the regulation of cardiogenic development and that perturbation in expression of vMLC2 is linked to the onset of dilated cardiomyopathy. In an attempt to develop an avian model for such studies, we examined the expression pattern of vMLC2 in chicken embryos at various stages and analyzed the effect of antisense oligonucleotide-mediated interference of vMLC2 function in cultures of whole embryos. Our results showed vMLC2 to be a specific marker for ventricular chamber throughout chicken embryonic development and antisense vMLC2 treatment of primitive streak stage (stage 4) embryos to produce pronounced dilation of heart tube with severe deficiency in formation of striated myofibrils. Further studies with antisense mRNA techniques of whole embryo cultures should, therefore, be useful to evaluate the role of vMLC2 and other putative regulatory factors in cardiac myofibrillogenesis.

Los oligonucleotidos antisense potencian la apoptosis inducida por la idarubicina en la linea celular K-562 / Antisense oligonucleotides increase the apoptotic effect of idarubicin in K-562 cell line

La línea celular K-562, portadora del rearreglo bcr/abl de tipo b3a2 es resistente a la apoptosis inducida por inhibidores de topoisomerasa II. Se trataron células de dicha línea con complejos de liposomas catiónicos (DMRIE-DOPE y Dcchol-DOPE) y oligonucleótidos antisense (ODNs AS) dirigidos contra el ARNm bcr/abl de tipo b3a2, y non sense (ODNs NS), en una razón 3:1 lípido/ADN, durante 72 horas, luego se incubaron durante 24 horas con idarubicina (IDA), 0.5 mug/ml, para inducir apoptosis. La misma se evaluó por observación morfológica al microscopio de fluorescencia. Las células tratadas con los conjugados DMRIE-DOPE y Dcchol/DOPE con el ODN AS específico mostraron un mayor porcentaje de apoptosis inducida por IDA (X + DS: 14.74 + 2.07 y 20.43 + 4.58, respectivamente) comparadas con los controles no tratados con ODNs (X + DS: 8.08 + 0.82); (p<0.005). Los datos indican que los ODNs-AS dirigidos contra el ARNm bcr-abl de tipo b3a2 vuelven a las células de la línea K-562 sensibles a la IDA a la concentración mencionada.

Role of Ras/ERK-dependent pathway in the erythroid differentiation of K562 cells

The chronic myelogenous leukemic K562 cell line carrying Bcr-Abl tyrosine kinase is considered as pluripotent hematopoietic progenitor cells expressing markers for erythroid, granulocytic, monocytic, and megakaryocytic lineages. Here we investigated the signaling modulations required for induction of erythroid differentiation of K562 cells. When the K562 cells were treated with herbimycin A (an inhibitor of protein tyrosine kinase), ras antisense oligonucleotide, and PD98059 (a specific inhibitor of MEK), inhibition of ERK/MAPK activity and cell growth, and induction of erythroid differentiation were observed. The ras mutant, pZIPRas61leu-transfected cells, K562-Ras61leu, have shown a markedly decreased cell proliferation rate with approximately 2-fold doubling time, compared with the parental K562 cells, and about 60% of these cells have shown the phenotype of erythroid differentiation. In addition, herbimycin A inhibited the growth rate and increased the erythroid differentiation, but did not affect the elevated activity of ERK/MAPK in the K562-Ras61leu cells. On the other hand, effects of PD98059 on the growth and differentiation of K562-Ras61leu cells were biphasic. At low concentration of PD98059, which inhibited the elevated activity of ERK/MAPK to the level of parental cells, the growth rate increased and the erythroid differentiation decreased slightly, and at high concentration of PD98059, which inhibited the elevated activity of ERK/MAPK below that of the parental cells, the growth rate turned down and the erythroid differentiation was restored to the untreated control level. Taken together, these results suggest that an appropriate activity of ERK/MAPK is required to maintain the rapid growth and transformed phenotype of K562 cells.

Terapia génica / Gene therapy

La aplicación de la genética molecular a la biología de la enfermedad humana tiene un profundo efecto en la comprensión de los mecanismos moleculares de la patogénesis de la enfermedad. En esta revisión se proporciona una introducción y bosquejo de la terapia génetica, y se presentan y discuten las técnicas más actualizadas para hacer la entrega de genes asi como las hazañas clínicas y experimentales realizadas hasta la fecha. El desarrollo de métodos de entrega de genes a células de mamífero lleva a la posibilidad de tratar la enfermedad humana a través de terapias basadas en genes. Como resultado, conceptos y métodos que podían considerarse ciencia ficción hace 50 años se aplican ahora en el tratamiento de diversas enfermedades. La aplicación de la terapia génica está rompiendo las fronteras tradicionales en la cual la medicina moderna ha estado sumergida. Sin embargo, no obstante los progresos, un gran número de dificultades técnicas necesitan ser resueltas antes de que la terapia génica pueda ser segura y eficientemente aplicada en la clínica. Los desarrollos tecnológicos, particularmente la entrega de genes y el trasplante celular, son críticos para la práctica exitosa de la terapia génica

Inhibition of HBV replication by antisense oligodeoxyribonucleotides in HepG2 cells transfected with a cloned HBV DNA

The effect of antisense oligodeoxyribonucleotides(oligo[dN]s) on hepatitis B virus(HBV) replication in HepG2 cells harboring a cloned HBV genome was examined. Antisense oligo(dN)s directed at translational initiation sites of S, pre C and P genes of HBV were treated to the cells and the amount of HBsAg and HBV DNA content were measured 72 hours after the treatment. HBsAg expressions in HepG2 cells harboring the HBV genome were inhibited 68%, 53%, and 46% by the treatment with antisense oligo[dN] directed at S, pre C, and P gene loci, respectively, and HBV DNA content in the cells was also reduced by the treatment of each antisense oligo[dN]. The doubling times of the cultured cells treated with 25 micrograms, 50 micrograms, and 100 micrograms of antisense oligo[dN]/ml medium were 43.3, 62.1, and 93.0 hours, respectively, compared with 37.5 hours of the untreated control cells. Cellular DNA synthesis was inhibited by the treatment with 100 micrograms/ml of antisense oligo [dN], however, no significant effect was observed by the treatment with 50 micrograms or less of antisense oligo[dN]/ml. These results suggested that antisense oligo[dN]s specific to the translational initiation sites of S, pre C, and P genes of HBV may have therapeutic potential for the suppression of HBV propagation in chronic HBV infected patients.