Trypanosoma cruzi XRNA granules colocalise with distinct mRNP granules at the nuclear periphery

BACKGROUND Eukaryotic ribonucleoprotein (RNP) granules are important for the regulation of RNA fate. RNP granules exist in trypanosomatids; however, their roles in controlling gene expression are still not understood. XRNA is a component of granules in Trypanosoma brucei but has not been investigated in Trypanosoma cruzi. OBJECTIVES This study aimed to investigate the TcXRNA dynamic assembly and its interaction with RNP components under conditions that affect the mRNA availability. METHODS We used in vitro metacyclogenesis of T. cruzi to observe changes in RNP granules during the differentiation process. TcXRNA expression was analysed by Western blot and immunofluorescence. Colocalisation assays were performed to investigate the interaction of TcXRNA with other RNP components. FINDINGS TcXRNA is constantly present during metacyclogenesis and is localised in cytoplasmic granules. TcXRNA does not colocalise with TcDHH1 and TcCAF1 granules in the cytoplasm. However, TcXRNA granules colocalise with mRNP granules at the nuclear periphery when mRNA processing is inhibited. MAIN CONCLUSIONS TcXRNA plays a role in mRNA metabolism as a component of mRNP granules whose assembly is dependent on mRNA availability. TcXRNA granules colocalise with distinct RNP granules at the nuclear periphery, suggesting that the perinuclear region is a regulatory compartment in T. cruzi mRNA metabolism.

Correlation between RNA Expression Level and Early PMI in Human Brain Tissue / 法医学杂志

OBJECTIVES@#To explore the correlation between the expression levels of several RNA markers in human brain tissue and early postmortem interval （PMI）.@*METHODS@#Twelve individuals with known PMI （range from 4.3 to 22.5 h） were selected and total RNA was extracted from brain tissue. Eight commonly used RNA markers were chosen including β-actin, GAPDH, RPS29, 18S rRNA, 5S rRNA, U6 snRNA, miRNA-9 and miRNA-125b, and the expression levels were detected in brain tissue by real-time fluorescent quantitative PCR. The internal reference markers with stable expression in early PMI were screened using geNorm software and the relationship between its expression level and some relevant factors such as age, gender and cause of death were analyzed. RNA markers normalized by internal reference were inserted into the mathematic model established by previous research for PMI estimation using R software. Model quality was judged by the error rate calculated with estimated PMI.@*RESULTS@#5S rRNA, miRNA-9 and miRNA-125b showed quite stable expression and their expression levels had no relation with age, gender and cause of death. The error rate of estimated PMI using β-actin was 24.6%, while GAPDH was 41.0%.@*CONCLUSIONS@#5S rRNA, miRNA-9 and miRNA-125b are suitable as internal reference markers of human brain tissue owing to their stable expression in early PMI. The expression level of β-actin correlates well with PMI, which can be used as an additional index for early PMI estimation.

Correlation between RNA Degradation Patterns of Rat's Brain and Early PMI at Different Temperatures / 法医学杂志

OBJECTIVES@#To explore the correlation between early postmortem interval （PMI） and eight RNA markers of rat's brain at different temperatures.@*METHODS@#Total 222 SD rats were randomly divided into control group （PMI=0 h） and four experimental groups. And the rats in the experimental groups were sacrificed by cervical dislocation and respectively kept at 5 ℃, 15 ℃, 25 ℃ and 35 ℃ in a controlled environment chamber. The RNA was extracted from brain tissues, which was taken at 9 time points from 1 h to 24 h postmortem. The expression levels of eight markers, β-actin, GAPDH, RPS29, 18S rRNA, 5S rRNA, U6 snRNA, miRNA-9 and miRNA-125b, were detected using real-time fluorescent quantitative PCR, respectively. Proper internal reference was selected by geNorm software. Regression analysis of normalized RNA markers was performed by SPSS software. Mathematical model for PMI estimation was established using R software. Another 6 SD rats with known PMI were used to verify the mathematical model.@*RESULTS@#5S rRNA, miR-9 and miR-125b were suitable as internal reference markers for their stable expression. Both β-actin and GAPDH had well time-dependent degradation patterns and degraded continually with prolongation of PMI in 24 h postmortem. The mathematical model of the variation of ΔCt values with PMI and temperature was set up by R software and the model could be used for PMI estimation. The average error rates of model validation using β-actin and GAPDH were 14.1% and 22.2%, respectively.@*CONCLUSIONS@#The expression levels of β-actin and GAPDH are well correlated with PMI and environmental temperature. The mathematical model established in present study can provide references for estimating early PMI under various temperature conditions.

Relationship between PMI and relative expression of myocardial various RNAs in rats died of different causes / 法医学杂志

OBJECTIVE@#To observe the changes of relative expression of myocardial various RNAs in rats died of different causes and their relationship with PMI.@*METHODS@#The rat models were established in which the rats were sacrificed by broken neck, asphyxia, and hemorrhagic shock. Total RNAs were extracted from myocardium. The quantitative real time PCR was used to calculate threshold cycle values of RNAs including glyceraldehyde-3-phosphate dehydrogenase (GAPDH), beta-actin, inducible nitric oxide synthase (iNOS), hypoxia-inducible factor-1 (HIF-1), tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and U6 small nuclear RNA (U6 snRNA) and to study the changes of the relative expressions of various indexes with PMI.@*RESULTS@#U6 snRNA with stable expression level could be used as appropriate internal control. In the early PMI, the relative expression of GAPDH, HIF-1, iNOS, TNF-alpha, and IL-6 more characteristically increased in groups of asphyxia and hemorrhagic shock than in group of broken neck, but the quantity of beta-actin decreased in all groups. In the late PMI, all the relative expressions significantly declined in correlation with the degradation of RNA.@*CONCLUSION@#The characteristic changes of each RNA expression can be used as references to estimate PMI in deaths by different causes.

U6 is unsuitable for normalization of serum miRNA levels in patients with sepsis or liver fibrosis

MicroRNA (miRNA) levels in serum have recently emerged as potential novel biomarkers for various diseases. miRNAs are routinely measured by standard quantitative real-time PCR (qPCR); however, the high sensitivity of qPCR demands appropriate normalization to correct for nonbiological variation. Presently, RNU6B (U6) is used for data normalization of circulating miRNAs in many studies. However, it was suggested that serum levels of U6 themselves might differ between individuals. Therefore, no consensus has been reached on the best normalization strategy in 'circulating miRNA'. We analyzed U6 levels as well as levels of spiked-in SV40-RNA in sera of 44 healthy volunteers, 203 intensive care unit patients and 64 patients with liver fibrosis. Levels of U6 demonstrated a high variability in sera of healthy donors, patients with critical illness and liver fibrosis. This high variability could also be confirmed in sera of mice after the cecal ligation and puncture procedure. Most importantly, levels of circulating U6 were significantly upregulated in sera of patients with critical illness and sepsis compared with controls and correlated with established markers of inflammation. In patients with liver fibrosis, U6 levels were significantly downregulated. In contrast, levels of spiked-in SV40 displayed a significantly higher stability both in human cohorts (healthy, critical illness, liver fibrosis) and in mice. Thus, we conclude that U6 levels in the serum are dysregulated in a disease-specific manner. Therefore, U6 should not be used for data normalization of circulating miRNAs in inflammatory diseases and previous studies using this approach should be interpreted with caution. Further studies are warranted to identify specific regulatory processes of U6 levels in sepsis and liver fibrosis.

In vivo susceptibility of plasmodium vivax to chloroquine in Southeastern Iran

Plasmodium vivax is the predominant species causes of malaria with about 90% total annual reported malaria in Iran. This study conducted to determine the susceptibility of Plasmodium vivax isolates to chloroquine in Sistan and Balochistan Province, southeastern Iran. A total 270 subjects with symptomatic malaria and confirmed P. vivax infection completed the designed 28-day in vivo study. The thick and thin film blood smears were screened for malaria parasites by microscopy. The nested PCR was applied using the Plasmodium 18 subunit ribosomal ribonucleic [Ssr RNA] genes for detecting mixed infections and diagnosis of parasites in the samples with low parasite on days 0, 5, 6, 7, and 28. P. vivax was cleared in 15%, 50%, 95%, and 100% of patients on days 1, 2, 3, 4 respectively by microscopy assessment. Six patients were exhibited specific P. vivax band in nested PCR on day 5. No recurrence was observed on days 7, 14 and 28. Mean [ +/- standard deviation] parasite clearance time was 2.41 [ +/- 0.8] days. P. vivax is still susceptible to chloroquine in Southeastern Iran. This finding is compatible with results of neighboring countries Pakistan and Afghanistan

Evaluation on stability of internal controls in human cardiac muscle by real-time RT-PCR during early postmortem interval / 法医学杂志

OBJECTIVE@#To explore the stability of internal controls in human cardiac muscle by real-time RT-PCR during early postmortem interval (PMI) in order to find the most stable marker.@*METHODS@#Ten individuals with similar environmental conditions (the average store temperature: 25 degrees C) and different PMI ranging from 4.3 to 22.3 h were selected. Total RNA was extracted from each sample and six commonly internal controls were used including beta-actin, GAPDH, B2M, U6, 18S rRNA and HSA-miR-1, and the expression was detected in cardiac muscle by real-time RT-PCR. The expression stability of internal controls was evaluated using genormPLUS software during early PMI. The internal control with the most stability was selected. The relationship between the most stable marker and its expression level affected by some other parameters such as age, gender and cause of death was also analyzed.@*RESULTS@#The U6 showed the most stable expression during early PMI in cardiac muscle, and its expression level was not affected by those parameters including age, gender and cause of death (P > 0.05).@*CONCLUSION@#U6 may be a valuable internal control for the study of relationship between PMI determination and degradation of nucleic acid in human cardiac muscle by real-time RT-PCR.

Combinatorial RNAi and its application in cancer gene therapy / 药学学报

RNA interference (RNAi) has been proved as a novel approach for gene therapy. However, RNAi mono-therapy only aims at single gene, it therefore may ultimately fail to cure cancers caused by polygene variation. To overcome the deficiency of RNAi mono-therapy, "combinatorial RNA interference" (coRNAi) was put forward as a new strategy. By co-expressing the inducers of RNAi triggering single or multiple targets directly and other RNA- or protein-based silencers, coRNAi keeps target genes silent, prevents carcinogenic progression and induces apoptosis of tumor cells. This paper mainly reviews the major strategies of coRNAi and their applications in cancer gene therapy.

Pseudouridines in spliceosomal snRNAs

Spliceosomal RNAs are a family of small nuclear RNAs (snRNAs) that are essential for pre-mRNA splicing. All vertebrate spliceosomal snRNAs are extensively pseudouridylated after transcription. Pseudouridines in spliceosomal snRNAs are generally clustered in regions that are functionally important during splicing. Many of these modified nucleotides are conserved across species lines. Recent studies have demonstrated that spliceosomal snRNA pseudouridylation is catalyzed by two different mechanisms: an RNA-dependent mechanism and an RNA-independent mechanism. The functions of the pseudouridines in spliceosomal snRNAs (U2 snRNA in particular) have also been extensively studied. Experimental data indicate that virtually all pseudouridines in U2 snRNA are functionally important. Besides the currently known pseudouridines (constitutive modifications), recent work has also indicated that pseudouridylation can be induced at novel positions under stress conditions, thus strongly suggesting that pseudouridylation is also a regulatory modification.

Caracterización molecular de los genes histona H2A y ARNsno-Cl de Trypanosoma rangeli: aplicación en pruebas diagnósticas / Molecular characterization of histone H2A and snoRNA-Cl genes of Trypanosoma rangeli: application in diagnostic tests

La aplicación de la reacción en cadena de la polimerasa (PCR) para detectar e identificar Trypanosoma rangeli y Trypanosoma rangeli presenta a menudo dificultades de interpretación. Así, algunas pruebas generan la amplificación de bandas similares provenientes de uno de los dos parásitos, fragmentos polimórficos de un mismo parásito, o la prevalencia en la detección de T. cruzi en infecciones mixtas. En este estudio se presentan y analizan los trabajos de investigación básica realizados con el objeto de diseñar y estandarizar pruebas de PCR específicas de cada parásito. Los iniciadores TcH2AF/R se diseñaron sobre la base de la región diferencial observada entre las unidades génicas que contienen los genes h2a en estos tripanosomas. Esta pareja de iniciadores amplifican un fragmento de 234 pb específico para T. cruzi (cepas I y II). Los iniciadores TrF/R2 anillan en las regiones intergénicas del fragmento génico de 801 pb codificante para seis transcritos que forman la agrupación ARNsno-Cl en T. rangeli. Estos iniciadores amplifican un fragmento de 620 pb exclusivo de las cepas KP1(-) y KP1(+) de este parásito. La aplicación de estas PCR en vectores infectados y en pacientes con enfermedad de Chagas muestra que ambas pruebas constituyen herramientas útiles para el diagnóstico y la identificación diferencial de estos tripanosomátidos.

The application of polymerase chain reaction (PCR) to detect Trypanosoma rangeli and Trypanosoma rangeli often presents interpretation challenges. For example, some tests yield the amplification of similar bands from either parasite, polymorphic fragments of the same parasite, or present deviation towards T. cruzi in mixed infections. In this study, the basic researching needed for designing and standardizating specific PCR tests for each parasite species PCR are shown and analyzed. The TcH2AF/R primers were designed on the basis of the differential gene region observed between the histone h2a genic units of these parasites. These primers amplify a specific 234 bp fragment in T. cruzi (T. cruzi I and II strains). The TrF/R2 primers anneal to the intergenic regions of an 801 bp gene fragment encoding for six transcripts that conform the snoRNA-Cl cluster in T. rangeli. These primers amplify a fragment of 620 bp exclusively in KP1(-) and KP1(+) strains of the parasite. The application of these PCR tests in infected vectors and in chagasic patients show that both tests constitute useful tools for the diagnosis and differential identification of these Trypanosomatids. Key words: histone, RNA small nucleolar (snoRNA), polymerase chain reaction (PCR), Trypanosoma.

Selecting functional siRNA target sites of hUBE2W based on H1-U6 dual promoter RNAi plasmid / 生物工程学报

hUBEW, a newly identified class I ubiquitin conjugating enzyme, probably plays an important role in tumorigenesis and DNA repair processes. RNA interference (RNAi) is a process in cells to degrade specific homologous mRNA by forming duplex RNA and has been developed into a powerful tool to study gene functions. In this study, the H1-U6 dual promoter RNAi plasmid was constructed and the target sequence for hUbe2w could be transcribed from both strands and form a double stranded RNA with two 5'Uridine overhangs, which closely resembles endogenous functional siRNA. The hUbe2w cDNA was amplified from reverse transcription of the 293FT total RNA by RT-PCR, and then cloned into the pGL3-Control, pCMV-myc and pDsRed-express-C1 plasmids respectively, which were selected as report vectors to detect the RNAi effects. The plasmids were co-transfected into HEK293FT cells, and then the luciferase activity and hUBE2W protein expression were measured respectively. The Resulted reduction of mRNA and protein level demonstrate that the targets of 125 and 259 could significantly inhibit the hUbe2w expression.

Cloning and molecular characterization of Trypanosoma cruzi U2, U4, U5, and U6 small nuclear RNAs

Small nuclear RNAs (snRNAs) are important factors in the functioning of eukaryotic cells that form several small complexes with proteins; these ribonucleoprotein particles (U snRNPs) have an essential role in the pre-mRNA processing, particularly in splicing, catalyzed by spliceosomes, large RNA-protein complexes composed of various snRNPs. Even though they are well defined in mammals, snRNPs are still not totally characterized in certain trypanosomatids as Trypanosoma cruzi. For this reason we subjected snRNAs (U2, U4, U5, and U6) from T. cruzi epimastigotes to molecular characterization by polymerase chain reaction (PCR) and reverse transcription-PCR. These amplified sequences were cloned, sequenced, and compared with those other of trypanosomatids. Among these snRNAs, U5 was less conserved and U6 the most conserved. Their respective secondary structures were predicted and compared with known T. brucei structures. In addition, the copy number of each snRNA in the T. cruzi genome was characterized by Southern blotting.

U7 snRNAs: a computational survey / 基因组蛋白质组与生物信息学报·英文版

U7 small nuclear RNA (snRNA) sequences have been described only for a handful of animal species in the past. Here we describe a computational search for functional U7 snRNA genes throughout vertebrates including the upstream sequence elements characteristic for snRNAs transcribed by polymerase II. Based on the results of this search, we discuss the high variability of U7 snRNAs in both sequence and structure, and report on an attempt to find U7 snRNA sequences in basal deuterostomes and non-drosophilids insect genomes based on a combination of sequence, structure, and promoter features. Due to the extremely short sequence and the high variability in both sequence and structure, no unambiguous candidates were found. These results cast doubt on putative U7 homologs in even more distant organisms that are reported in the most recent release of the Rfam database.

Preparation of small interfering RNA expression cassette based on PCR technique / 南方医科大学学报

<p><b>OBJECTIVE</b>To modify the current PCR-based method for rapid and efficient preparation of small interfering RNA (siRNA) expression cassette to improve the efficiency of RNA interference.</p><p><b>METHODS</b>The U6 promoter sequence was amplified by PCR using the genomic DNA of K562 cells as the template, and cloned into pMD18-T vector which served as the template for further PCR amplification with the primers on the plasmid. The amplified product was directly used as the template for preparing siRNA expression cassette. The siRNA expression cassette targeting p53 gene was amplified, verified by sequencing, and transfected into SH-SY5Y cells. After a 48-hour transfection, the cells were harvested and the total RNA was for RT-PCR for evaluating the effect of RNA interference.</p><p><b>RESULTS</b>The sequencing result confirmed the correct U6 promoter sequence cloned from K562 cells. After transfection of SH-SY5Y cells for 48 h with siRNA expression cassette, the p53 gene expression was inhibited at the mRNA level in comparison with the control cells as demonstrated by RT-PCR detection.</p><p><b>CONCLUSION</b>The siRNA expression cassette prepared using the established method described hereby can be well applicable in RNA interference research.</p>

Inhibition of HCV replication by HCV specific U1 small nuclear RNA chimeric ribozyme in vivo / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To determine the advantage of U1 small nuclear RNA as a ribozyme vector (U1-Rz) to inhibit HCV replication in vivo.</p><p><b>METHODS</b>The 3rd stem-loop was substituted by HCV core specific ribozyme to construct an U1-Rz eucaryotic expression plasmid. Then it was co-transfected with pCMV/T7-NCRC Delta-luc into Huh7 cell line mediated by lipofectin. The cell lysis supernatant was subjected to Western blot and lumenometer to determine the luciferase levels.</p><p><b>RESULTS</b>A U1 snRNA chimeric ribozyme was constructed successfully. Both Rz and U1-Rz inhibited luciferase expression in Huh7 by 48.64% and 87.46%, respectively.</p><p><b>CONCLUSION</b>Rz has more efficacy in cells when using U1 snRNA delivery system. U1 can be an efficient vector for HCV specific ribozyme.</p>

Construction of pEGFP-C1/U6-mediated plasmid expressing MDR1 shRNA / 中国实验血液学杂志

To construct a plasmid expressing MDR1 short hairpin RNA (shRNA) mediated by pEGFP-C1/U6 vector, two coding sequences of 19 nucleotides were selected from MDR. Two pairs of oligonucleotides were designed for these two fragments. After annealing the formed double-stranded DNAs were ligated with plasmid pEGFP-C1/U6 (pEGFP-C1 vector with U6 promoter). The plasmids producing MDR1 shRNA were constructed from the inverted motif containing 9 spacers and four Ts. The results showed that the constructed plasmids were named pEGFP-C1/U6/A and pEGFP-C1/U6/B, and the constructs were identified by restriction and sequence analysis, no any base mutation was observed. It is concluded that plasmids of pEGFP-C1/U6/A and pEGFP-C1/U6/B expressing MDR1 shRNA were successfully constructed, providing a highly effective method for reversing the multidrug resistance in clinic.

Identificación de una agrupación génica que codifica para ARN pequeños de nucleólo en Trypanosoma Rangeli / Identification of a Genetic Cluster Codingfor Six Small Nucleolar RNA in Trypanosoma rangeli

Objetivo. Realizar un análisis in silico de un fragmento de 801 pb de Trypanosoma rangeli, previamente reportado como codificante para el ARN pequeño de nucléolo C1, perteneciente a la familia de los C/D snoARN. Materiales y métodos. El tamizaje de las secuencias se realizó en las bases de datos de los diferentes proyectos de genomas de los parásitos usando el programa BLASTN. Las alineaciones de las secuencias se hicieron con los programas L-ALIGN y Clustal W. Resultados. La secuencia C1 constituye una agrupación génica que codifica para seis ARN pequeños de nucléolo, tres pertenecientes a la familia C/D snoARN y tres a la famila H/ACA snoARN. Conclusión. Los ARN pequeños de nucléolo de Trypanosomatidae presentan una organización genómica similar y elevados porcentajes de identidad en las secuencias consenso, lo cual unido a las funciones de estos ARN en el procesamiento y modificación posteriores a la transcripción del ARN ribosómico y, también, en el proceso de trans splicing, hace de estas moléculas un blanco atractivo para el control de estos parásitos

Specific inhibition of hTERT gene expression by short interfering RNAs in gastric cancer SGC7901 cell / 中华外科杂志

<p><b>OBJECTIVE</b>Activation of hTERT, the human telomerase catalytic subunit, has been implicated as the critical event in triggering telomerase activity of cancer cells. In present research, we investigated whether RNA interference (RNAi) induced by small interference RNA (siRNA) could suppress human telomerase catalytic unit (hTERT) gene expression in gastric SGC7901 cells.</p><p><b>METHODS</b>As a pilot study, we utilized green fluorescent protein (GFP) plasmid pCX-GFP (5 510 bp) as a reporter system and generated constructs SHi-pU6-GFP expressing small hairpin RNA (shRNA) specific for green fluorescence protein (GFP) in K562 and SGC7901 cell respectively. Furthermore, we constructed pU6-hTERT-siRNAs carried hairpin siRNA for hTERT gene and transfected in SGC7901 by using Lipofectamine trade mark 2000. The expression of hTERT gene was detected by reverse transcription polymerase chain reaction (RT-PCR) and fluorescence quantitative polymerase chain reaction (FQ-PCR) assay.</p><p><b>RESULTS</b>Our pilot study showed the short hairpin RNA (shRNA) expression vector driven by the murine U6 small nuclear RNA promoter can specifically induce potent gene knockdown effect (i.e., inhibit GFP expression specifically) when transfected transiently into SGC7901 cell. The constructed pU6-hTERT-siRNAs carried hairpin siRNA for hTERT gene was proved to be the same as designed by restriction endonuclease analysis. pU6-hTERT-siRNAs were successfully transferred into SGC7901 cell and their stable expression were obtained. The expression of hTERT gene were specific inhibited by pU6-hTERT-siRNAs in SGC7901 cell.</p><p><b>CONCLUSIONS</b>Short hairpin RNAs (shRNAs) could induce sequence-specific hTERT gene silencing in SGC7901 cell. Our results prove the feasibility of the U6 promoter-driven shRNA expression technique to be used to cancer gene therapy.</p>

Study on the cleavage activity of U1 small nuclear RNA chimeric ribozyme against HCV RNA in vitro / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To study the cleavage activity on the HCV RNA of a chimeric recombinant of HCV specific ribozyme and U1 small nuclear RNA, which compartmentalizes within the nucleolus.</p><p><b>METHODS</b>The third stem-loop sequence of human U1 snRNA (position 95-116) within pBSIISK+ U1 was substituted by hammerhead ribozyme against HCV RNA by PCR and cloning methods, and the constructed plasmid was named pBSIISK+ (U1-Rz). Then the whole gene fragment of the chimeric ribozyme was cloned into a pGEM-T vector under the control of T7 promoter, and the constructed plasmid was named pGEM- (U1-Rz). The pGEM- (U1-Rz) and pGEM-Rz (containing the same ribozyme sequence as that in U1-Rz) transcripts as enzyme were transcribed in vitro. Also the (32)P-labeled pCMV/T7-NCRC luc (containing the gene sequence of the whole 5'-NCR and part core of HCV RNA) transcripts as target-RNAs were transcribed in vitro. The enzymes were incubated with the target RNAs under different conditions and autoradiographed after denaturing gel-electrophoresis.</p><p><b>RESULTS</b>The sequencing result showed that the construction of U1 snRNA chimeric ribozyme was correct. Compared with the ribozyme alone, both of them were active at 37 degree C and with Mg2+ (10 mmol/L) and TrisCl (10 mmol/L, pH7.9), and there was no remarkable difference between them. The cleavage activity of the chimeric ribozyme increased with the prolongation of reaction time and increment of enzyme concentration.</p><p><b>CONCLUSION</b>Both ribozyme and U1 snRNA chimeric ribozyme exhibited specifically catalytic activity against HCV RNA in vitro. There was no remarkable difference between their cleavage efficiencies.</p>

Molecular analysis of snRNAs and scRNAs using autoantibodies from patients with systemic lupus erythematosus

Immunoprecipitation analysis of total HeLa cells RNA extract byprotein A-Sheparose purified autoantibodies and pCp 32P-3' end labeling RNAs revealed that U1, U2, U4 and U5 snRNAs are related with anti-Sm or U1nRNP autoantibodies, while the hY1, hY3, hY4 and hY5 scRNAs were related to anti-SSA/Ro autoantibodies present in sera of patient with Systemic Lupus Erythematosus. The authors detected molecular snRNAs and scRNAs specificities by autoantibodies in 71 sera, the molecular RNA specificity for anti-Sm (U1, U2, U4 and U5 snRNAs) was present in 39 percent; anti-SSA/Ro sera reacted against scRNAs (hY1, hY3, hY4 and hY5) in 36 percent, then anti-U1nRNP sera recognized U1 snRNA in 13 percent of sera and anti-rRNP related with rRNA were recognized in 8 percent. Twenty-nine SLE sera were RNA negative. A molecular characterization of the autoantibodies in sera from SLE patients may be a useful tool for clinical and laboratory diagnosis of SLE, and the use of autoantibodies es molecular probes allows to continue exploring some basic mechanism of gene expression