Small Nuclear RNAs U11 and U12 Modulate Expression of TNR-CFTR mRNA in Mammalian Kidneys

TNR-CFTR, discovered as a splice variant of CFTR (Cystic Fibrosis Transmembrane conductance Regulator), is distributed in different tissues such as human and rat kidney, trachea, lungs etc and is a functional chloride channel. In Kidneys, our findings show TNR-CFTR to have an unique distribution pattern with low levels of expression in renal cortex and high levels of expression in renal medulla. As shown by us previously, TNR-CFTR mRNA lacks 145 bp corresponding to segments of exons 13 and 14. This deletion causes a frame shift mutation leading to reading of a premature termination codon in exon 14. Premature termination of translation produces a functional half molecule of CFTR; TNR-CFTR. Our analysis of TNR mRNA has shown that the putative alternatively spliced intron has in its 5′ and 3′ conserved element CT and AC, respectively, that can be recognized by snRNAs U11 and U12. With these findings, we hypothesize that TNR-CFTR mRNA alternative splicing is probably mediate by splicing pathways utilizing U11 and U12 snRNAs. In this study, we have determined sequences of snRNAs U11 and U12 derived from rat kidney, which show significant homology to human U11 and U12 snRNAs. We show that there is significantly lower expression of U11 and U12 snRNAs in renal cortex compared to renal medulla in both humans and rats. This renal pattern of distribution of U11 and U12 snRNAs in both humans and rats closely follows distribution pattern of renal TNR-CFTR. Further, we have shown that blocking U11 and/or U12 mRNAs, by using antisense probes transfected in Immortalized Rat Proximal Tubule Cell line (IRPTC), decreases TNR-CFTR mRNA expression but not wild-type CFTR mRNA expression. Our results suggest that expression of U11 and/or U12 snRNAs is important for non-conventional alternative splicing process that gives rise to mRNA transcript coding for TNR-CFTR

Methods to Unravel Pathways of Reactive Oxygen Species in the Photodynamic Inactivation of Bacteria

Different experimental conditions can be used to detect the presence of reactive oxygen species (ROS) in the photodynamic inactivation of microorganisms. Here, we describe the effect of the media and the addition of ROS scavengers to obtain insight about the oxidative processes that take place during the photokilling of bacteria. In addition, 9,10-dimethylanthracene was used to sense the generation of singlet molecular oxygen, O2(1Δg), in microbial cells. Thus, the contribution of type I or type II pathways in the photocytotoxicity action can be rapidly detected and compared between different photosensitizers.Fil: Gsponer, Natalia Soledad. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; Argentina. Universidad Nacional de Río Cuarto. Instituto para el Desarrollo Agroindustrial y de la Salud. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto para el Desarrollo Agroindustrial y de la Salud; ArgentinaFil: Durantini, Edgardo Néstor. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; Argentina. Universidad Nacional de Río Cuarto. Instituto para el Desarrollo Agroindustrial y de la Salud. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto para el Desarrollo Agroindustrial y de la Salud; Argentin

Intramolecular Charge Transfer Reaction, Polarity, and Dielectric Relaxation in AOT/Water/Heptane Reverse Micelles: Pool Size Dependence

Intramol. charge transfer (ICT) reaction in a newly synthesized mol., of 4-(41-morpholinyl) benzonitrile (M6C), in AOT/water/heptane reverse micelles at different pool sizes has been studied by using steady-state and time-resolved fluorescence emission spectroscopy. The pool size dependences of the reaction equil. const. and reaction rate have been explained in terms of the av. polarity of the confined solvent pools estd. from the fluorescence emission Stokes shift of a nonreactive probe, coumarin 153, dissolved in these microemulsions. The complex permittivity measurements in the frequency range 0.01 ≤ ν/GHz ≤ 2 for these microemulsions at different pool sizes (0 ≤ w ≤ 40) and AOT concns. (0.1 ≤ c/M ≤ 0.5) at 298.15 K have also been performed. At sufficient water content, a large dispersion with a relaxation time of ∼600 ps has been obsd. at ∼300 MHz and attributed to the av. reorientation of water mols. residing in the close vicinity of the polar interface of the AOT headgroup and n-heptane. The reorientation of these interfacial water mols. is probably responsible for the nanosecond component obsd. in numerous polar solvation dynamics expts. in these reverse micelles. Subsequently, the estd. polarity and the measured reorientational time scale have been used to explain the dramatic slowing down of the ICT reaction rate and its dependence on pool size in these confined environments