PINCH1 Is Transcriptional Regulator in Podocytes That Interacts with WT1 and Represses Podocalyxin Expression

Background: PINCH1, an adaptor protein containing five LIM domains, plays an important role in regulating the integrin-mediated cell adhesion, migration and epithelial-mesenchymal transition. PINCH1 is induced in the fibrotic kidney after injury, and it primarily localizes at the sites of focal adhesion. Whether it can translocate to the nucleus and directly participate in gene regulation is completely unknown. Methodology/Principal Findings: Using cultured glomerular podocytes as a model system, we show that PINCH1 expression was induced by TGF-β1, a fibrogenic cytokine that promotes podocyte dysfunction. Interestingly, increased PINCH1 not only localized at the sites of focal adhesions, but also underwent nuclear translocation after TGF-β1 stimulation. This nuclear translocation of PINCH1 was apparently dependent on the putative nuclear export/localization signals (NES/NLS) at its C-terminus, as deletion or site-directed mutations abolished its nuclear shuttling. Co-immunoprecipitation and pull-down experiments revealed that PINCH1 interacted with Wilms tumor 1 protein (WT1), a nuclear transcription factor that is essential for regulating podocyte-specific gene expression in adult kidney. Interaction of PINCH1 and WT1 was mediated by the LIM1 domain of PINCH1 and C-terminal zinc-finger domain of WT1, which led to the suppression of the WT1-mediated podocalyxin expression in podocytes. PINCH1 also repressed podocalyxin gene transcription in a promoter-luciferase reporter assay. Conclusion/Significance: These results indicate that PINCH1 can shuttle into the nucleus from cytoplasm in podocytes, wherein it interacts with WT1 and suppresses podocyte-specific gene expression. Our studies reveal a previously unrecognized, novel function of PINCH1, in which it acts as a transcriptional regulator through controlling specific gene expression. © 2011 Wang et al

Trigonometric Regressive Spectral Analysis Reliably Maps Dynamic Changes in Baroreflex Sensitivity and Autonomic Tone: The Effect of Gender and Age

BACKGROUND: The assessment of baroreflex sensitivity (BRS) has emerged as prognostic tool in cardiology. Although available computer-assisted methods, measuring spontaneous fluctuations of heart rate and blood pressure in the time and frequency domain are easily applicable, they do not allow for quantification of BRS during cardiovascular adaption processes. This, however, seems an essential criterion for clinical application. We evaluated a novel algorithm based on trigonometric regression regarding its ability to map dynamic changes in BRS and autonomic tone during cardiovascular provocation in relation to gender and age. METHODOLOGY/PRINCIPAL FINDINGS: We continuously recorded systemic arterial pressure, electrocardiogram and respiration in 23 young subjects (25+/-2 years) and 22 middle-aged subjects (56+/-4 years) during cardiovascular autonomic testing (metronomic breathing, Valsalva manoeuvre, head-up tilt). Baroreflex- and spectral analysis was performed using the algorithm of trigonometric regressive spectral analysis. There was an age-related decline in spontaneous BRS and high frequency oscillations of RR intervals. Changes in autonomic tone evoked by cardiovascular provocation were observed as shifts in the ratio of low to high frequency oscillations of RR intervals and blood pressure. Respiration at 0.1 Hz elicited an increase in BRS while head-up tilt and Valsalva manoeuvre resulted in a downregulation of BRS. The extent of autonomic adaption was in general more pronounced in young individuals and declined stronger with age in women than in men. CONCLUSIONS/SIGNIFICANCE: The trigonometric regressive spectral analysis reliably maps age- and gender-related differences in baroreflex- and autonomic function and is able to describe adaption processes of baroreceptor circuit during cardiovascular stimulation. Hence, this novel algorithm may be a useful screening tool to detect abnormalities in cardiovascular adaption processes even when resting values appear to be normal

The fallacy of placing confidence in confidence intervals

Interval estimates – estimates of parameters that include an allowance for sampling uncertainty – have long been touted as a key component of statistical analyses. There are several kinds of interval estimates, but the most popular are confidence intervals (CIs): intervals that contain the true parameter value in some known proportion of repeated samples, on average. The width of confidence intervals is thought to index the precision of an estimate; CIs are thought to be a guide to which parameter values are plausible or reasonable; and the confidence coefficient of the interval (e.g., 95 %) is thought to index the plausibility that the true parameter is included in the interval. We show in a number of examples that CIs do not necessarily have any of these properties, and can lead to unjustified or arbitrary inferences. For this reason, we caution against relying upon confidence interval theory to justify interval estimates, and suggest that other theories of interval estimation should be used instead

Ruthenium(II) bipyridine complexes with modified phenolic Schiff base ligands. Synthesis, spectroscopic characterization and redox properties

A group of stable new ruthenium(II) mixed-ligand tris-chelated complexes of the type [Ru (bpy)(2)L]ClO4 (bpy = 2,2'-bipyridine; L = deprotonated form of the HL ligands, o-(HO)-C6H3(R)C(R')=N-CH2-C6H5 or o-(HO)-C6H3(R)C(R')=N-NH-C6H5; where R = H, p-NO2 and R' = H, CH,) have been synthesized and characterized. The complexes are essentially diamagnetic and behave as 1:1 electrolytes in acetonitrile solution. They display two metal-to-ligand-charge-transfer (MLCT) transitions near 500 and 400 nm respectively and intra ligand pi-pi* transitions in the UV-region. In acetonitrile solution the complexes exhibit weak emission from the lowest energy MLCT band at room-temperature. The quantum yields of the complexes are found to be in the range 0.0004-0.01. In acetonitrile solution the complexes show quasi-reversible ruthenium(II)-ruthenium(III) oxidation couples in the range 0.33 --> 0.70 V and irreversible ruthenium (III)-ruthenium(IV) oxidations in the range 1.53 --> 1.95 V vs SCE. Two successive reversible bipyridine reductions are observed for each complex in the ranges -1.4 --> -1.62 V and -1.59 --> -1.85 V vs SCE respectively. The presence of trivalent ruthenium in the oxidized solution for one complex 5 is evidenced by the rhombic EPR spectrum with g values, g(1) = 2.389, g(2) = 2.081 and g(3) = 1.810. The EPR spectrum of the coulometrically oxidized species, 5(+) has been analyzed to furnish values of axial (Delta = 4745 cm(-1)) and rhombic (V = 3692 cm(-1)) distortion parameters as well as the energies of the two expected ligand held transitions (nu(1) = 3071 cm(-1) and nu(2) = 6819 cm(-1)) within the t(2) shell. One of the ligand field transitions has been observed experimentally at 6578 cm(-1) by near-IR spectrum which is close to the computed nu(2) value. (C) 1998 .