70 research outputs found
A Potential Regulatory Role for Intronic microRNA-338-3p for Its Host Gene Encoding Apoptosis-Associated Tyrosine Kinase
MicroRNAs (miRNAs) are important gene regulators that are abundantly expressed in both the developing and adult mammalian brain. These non-coding gene transcripts are involved in post-transcriptional regulatory processes by binding to specific target mRNAs. Approximately one third of known miRNA genes are located within intronic regions of protein coding and non-coding regions, and previous studies have suggested a role for intronic miRNAs as negative feedback regulators of their host genes. In the present study, we monitored the dynamic gene expression changes of the intronic miR-338-3p and miR-338-5p and their host gene Apoptosis-associated Tyrosine Kinase (AATK) during the maturation of rat hippocampal neurons. This revealed an uncorrelated expression pattern of mature miR-338 strands with their host gene. Sequence analysis of the 3′ untranslated region (UTR) of rat AATK mRNA revealed the presence of two putative binding sites for miR-338-3p. Thus, miR-338-3p may have the capacity to modulate AATK mRNA levels in neurons. Transfection of miR-338-3p mimics into rat B35 neuroblastoma cells resulted in a significant decrease of AATK mRNA levels, while the transfection of synthetic miR-338-5p mimics did not alter AATK levels. Our results point to a possible molecular mechanism by which miR-338-3p participates in the regulation of its host gene by modulating the levels of AATK mRNA, a kinase which plays a role during differentiation, apoptosis and possibly in neuronal degeneration
Different Effect of Proteasome Inhibition on Vesicular Stomatitis Virus and Poliovirus Replication
Proteasome activity is an important part of viral replication. In this study, we examined the effect of proteasome inhibitors on the replication of vesicular stomatitis virus (VSV) and poliovirus. We found that the proteasome inhibitors significantly suppressed VSV protein synthesis, virus accumulation, and protected infected cells from toxic effect of VSV replication. In contrast, poliovirus replication was delayed, but not diminished in the presence of the proteasome inhibitors MG132 and Bortezomib. We also found that inhibition of proteasomes stimulated stress-related processes, such as accumulation of chaperone hsp70, phosphorylation of eIF2α, and overall inhibition of translation. VSV replication was sensitive to this stress with significant decline in replication process. Poliovirus growth was less sensitive with only delay in replication. Inhibition of proteasome activity suppressed cellular and VSV protein synthesis, but did not reduce poliovirus protein synthesis. Protein kinase GCN2 supported the ability of proteasome inhibitors to attenuate general translation and to suppress VSV replication. We propose that different mechanisms of translational initiation by VSV and poliovirus determine their sensitivity to stress induced by the inhibition of proteasomes. To our knowledge, this is the first study that connects the effect of stress induced by proteasome inhibition with the efficiency of viral infection
MiR-218 Inhibits Invasion and Metastasis of Gastric Cancer by Targeting the Robo1 Receptor
MicroRNAs play key roles in tumor metastasis. Here, we describe the regulation and function of miR-218 in gastric cancer (GC) metastasis. miR-218 expression is decreased along with the expression of one of its host genes, Slit3 in metastatic GC. However, Robo1, one of several Slit receptors, is negatively regulated by miR-218, thus establishing a negative feedback loop. Decreased miR-218 levels eliminate Robo1 repression, which activates the Slit-Robo1 pathway through the interaction between Robo1 and Slit2, thus triggering tumor metastasis. The restoration of miR-218 suppresses Robo1 expression and inhibits tumor cell invasion and metastasis in vitro and in vivo. Taken together, our results describe a Slit-miR-218-Robo1 regulatory circuit whose disruption may contribute to GC metastasis. Targeting miR-218 may provide a strategy for blocking tumor metastasis
Novel inhibitors of the calcineurin/NFATc hub - alternatives to CsA and FK506?
The drugs cyclosporine A (CsA) and tacrolimus (FK506) revolutionized organ transplantation. Both compounds are still widely used in the clinic as well as for basic research, even though they have dramatic side effects and modulate other pathways than calcineurin-NFATc, too. To answer the major open question - whether the adverse side effects are secondary to the actions of the drugs on the calcineurin-NFATc pathway - alternative inhibitors were developed. Ideal inhibitors should discriminate between the inhibition of (i) calcineurin and peptidyl-prolyl cis-trans isomerases (PPIases; the matchmaker proteins of CsA and FK506), (ii) calcineurin and the other Ser/Thr protein phosphatases, and (iii) NFATc and other transcription factors. In this review we summarize the current knowledge about novel inhibitors, synthesized or identified in the last decades, and focus on their mode of action, specificity, and biological effects
Electroanalysis may be used in the Vanillin Biotechnological Production
This study shows that electroanalysis may be used in vanillin biotechnological production. As a matter of fact, vanillin and some molecules implicated in the process like eugenol, ferulic acid, and vanillic acid may be oxidized on electrodes made of different materials (gold, platinum, glassy carbon). By a judicious choice of the electrochemical method and the experimental conditions the current intensity is directly proportional to the molecule concentrations in a range suitable for the biotechnological process. So, it is possible to imagine some analytical strategies to control some steps in the vanillin biotechnological production: by sampling in the batch reactor during the process, it is possible to determine out of line the concentration of vanillin, eugenol, ferulic acid, and vanillic acid with a gold rotating disk electrode, and low concentration of vanillin with addition of hydrazine at an amalgamated electrode. Two other possibilities consist in the introduction of electrodes directly in the batch during the process; the first one with a gold rotating disk electrode using linear sweep voltammetry and the second one requires three gold rotating disk electrodes held at different potentials for chronoamperometry. The last proposal is the use of ultramicroelectrodes in the case when stirring is not possible
A novel forward-backward zero bus power flow method for the placement of renewable DGs in distribution network
The zero bus power flow (ZBPF) method is a recent development in the field of operation of active distribution network with renewable distributed generations (RNDGs), where a certain percentage of the total real and reactive power load demand is imported from the main grid, and the rest of the load demand is supplied by the DGs. DG connected to the zero bus ensures the pre-specified energy exchange with the upstream grid and the distribution network. However, to adopt the idea the standard load flow should be changed due to the absence of a slack bus. In literature, Newton-Raphson load flow (NRLF) is available; however, NRLF will not be converged for the distribution networks where the ratio of resistance to inductance is very high. To sort out this issue, a modified forward-backward based load flow is developed in this paper to consider the effect of zero bus and pre-specified energy exchange with the upstream grid. To determine the location of zero bus, locations and the sizes of DGs, and shunt capacitor, a multi-objective optimization problem (MOOP) is proposed here. The fuzzy maxmin principle (FMMP) based mixed discrete particle swarm optimization (MDPSO) is applied for the optimal placement of the RNDGs, and shunt capacitor in 33 bus DN
Tribal Odisha Eye Disease Study (TOES # 2) Rayagada school screening program: efficacy of multistage screening of school teachers in detection of impaired vision and other ocular anomalies
Lapam Panda,1 Taraprasad Das,1 Suryasmita Nayak,1 Umasankar Barik,2 Bikash C Mohanta,1 Jachin Williams,3 Vivekanand Warkad,4 Guha Poonam Tapas Kumar,5 Rohit C Khanna3 1Indian Oil Center for Rural Eye Health, GPR ICARE, L V Prasad Eye Institute, MTC Campus, Bhubaneswar, India; 2Naraindas Morbai Budhrani Eye Centre, L V Prasad Eye Institute, Rayagada, India; 3Gullapalli Pratibha Rao International Center for Advancement of Rural Eye Care, L V Prasad Eye Institute, KAR Campus, Hyderabad, India; 4Miriam Hyman Children Eye Care Center, L V Prasad Eye Institute, MTC Campus, Bhubaneswar, India; 5District Administration, Government of Odisha, Rayagada, India Purpose: To describe program planning and effectiveness of multistage school eye screening and assess accuracy of teachers in vision screening and detection of other ocular anomalies in Rayagada District School Sight Program, Odisha, India.Methods: This multistage screening of students included as follows: stage I: screening for vision and other ocular anomalies by school teachers in the school; stage II: photorefraction, subjective correction and other ocular anomaly confirmation by optometrists in the school; stage III: comprehensive ophthalmologist examination in secondary eye center; and stage IV: pediatric ophthalmologist examination in tertiary eye center. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of teachers for vision screening and other ocular anomaly detection were calculated vis-à-vis optometrist (gold standard).Results: In the study, 216 teachers examined 153,107 (95.7% of enrolled) students aged 5–15 years. Teachers referred 8,363 (5.4% of examined) students and 5,990 (71.6% of referred) were examined in stage II. After prescribing spectacles to 443, optometrists referred 883 students to stage III. The sensitivity (80.51%) and PPV (93.05%) of teachers for vision screening were high, but specificity (53.29%) and NPV (26.02%) were low. The specificity and NPV, in general, were higher in ocular anomaly detection but varied from disease to disease.Conclusion: Multistage school screening is rapid and comprehensive in a resource-limited community. Regular training and periodic reinforcement of teachers for vision assessment and other ocular anomaly identification are required for further success of the strategy. Keywords: vision screening, school children, sensitivity, specificity, tribal, ocular anomalie
Numerical Modeling of the Dynamics of Malaria Transmission in a Highly Endemic Region of India
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