Chelidonin a Homochelidonin indukují buněčnou smrt prostřednictvím drah checkpoint a MAP kináz

This study focuses on the comparative in vitro cytotoxicity of chelidonine and homochelidonine on human cancer and non-cancer cells. Both alkaloids produced a decrease in cellular growth in a dose-dependent manner exhibiting greater potency in cancer cells. The growth inhibitory effect was evidenced in both ovarian carcinoma A2780 and lung fibroblast MRC-5 cells by inducing G2 and mitotic phase cell cycle arrest. Results indicated that the extent of apoptosis induced by chelidonine and homochelidonine was correlated to sensitivity to the antiproliferative activity of the evaluated compounds. Western blotting suggested that the cellular toxicological mechanism of chelidonine is related to the differential upregulation of phospho-Chk2, p21(Cip1/Waf1), phospho-ERK1/2 and phospho-p38 in various cell types, leading to alternations in the suppression of proliferation and either induction or prevention of apoptosis. Chelidonine showed the more potent effects and also affected the cell cycle checkpoints and MAPK signaling pathways within cells.Tato práce je zaměřena na srovnávací cytotoxicitu chelidoninu a homochelidoninu na lidských nádorových a nenádorových buňkách

The 9aaTAD Transactivation Domains: From Gal4 to p53

<div><p>The family of the Nine amino acid Transactivation Domain, 9aaTAD family, comprises currently over 40 members. The 9aaTAD domains are universally recognized by the transcriptional machinery from yeast to man. We had identified the 9aaTAD domains in the p53, Msn2, Pdr1 and B42 activators by our prediction algorithm. In this study, their competence to activate transcription as small peptides was proven. Not surprisingly, we elicited immense 9aaTAD divergence in hundreds of identified orthologs and numerous examples of the 9aaTAD species' convergence. We found unforeseen similarity of the mammalian p53 with yeast Gal4 9aaTAD domains. Furthermore, we identified artificial 9aaTAD domains generated accidentally by others. From an evolutionary perspective, the observed easiness to generate 9aaTAD transactivation domains indicates the natural advantage for spontaneous generation of transcription factors from DNA binding precursors.</p></div

DNA damage and arterial hypertension. A systematic review and meta-analysis

Oxidative DNA damage markers (8OHdG, comet assay, gammaH2AX) are becoming widely used in clinical cardiology research. To conduct this review of DNA damage in relation to hypertension in humans, we used databases (e.g. PubMed, Web of Science) to search for English-language publications up to June 30, 2022 and the terms: DNA damage, comet assay, gammaH2AX, 8OHdG, strand breaks, and arterial hypertension. Exclusion criteria were: children, absence of relevant controls, extra-arterial hypertensive issues, animal, cell lines. From a total of 79526, 15 human studies were selected. A total of 902 hypertensive patients (pts): (comet: N=418 pts; 8OHdG: N=484 pts) and 587 controls (comet: N=203; 8OHdG: N=384) were included. DNA damage was significantly higher in hypertensive pts than healthy controls (comet 26.6±11.0 vs 11.7±4.07 arbitrary units /A.U./; P&lt;0.05 and="" 8ohdg="" 13="" 1="" 4="" 12="" vs="" 6="" 97="" 2="" 67="" ng="" mg="" creatinine="" i=""&gt; P&lt;0.05) confirmed with meta-analysis for both. Greater DNA damage was observed in more adverse cases (concentric cardiac hypertrophy 43.4±15.4 vs 15.6±5.5; sustained/untreated hypertension 31.4±12.1 vs 14.2±5/35.0±5.0 vs 25.0 ±5.0; non-dippers 39.2±15.5 vs 29.4±11.1 A.U.; elderly 14.9±4.5 vs 9.3±4.1 ng/mg creatinine; without carvedilol 9.1±4.2 vs 5.7±3.9; with coronary heart disease 0.5±0.1 vs 0.2±0.1 ng/mL) (P&lt;0.05) confirmed with meta-analysis. DNA damage correlated strongly positively with serum glycosylated haemoglobin (r=0.670; P&lt;0.05) and negatively with total antioxidant status (r=-0.670 to -0.933; P&lt;0.05). This is the first systematic review with meta-analysis showing that oxidative DNA damage was increased in humans with arterial hypertension compared to controls

The 9aaTAD Is Exclusive Activation Domain in Gal4

<div><p>The Gal4 protein is a well-known prototypic acidic activator that has multiple activation domains. We have previously identified a new activation domain called the nine amino acid transactivation domain (9aaTAD) in Gal4 protein. The family of the 9aaTAD activators currently comprises over 40 members including p53, MLL, E2A and other members of the Gal4 family; Oaf1, Pip2, Pdr1 and Pdr3. In this study, we revised function of all reported Gal4 activation domains. Surprisingly, we found that beside of the activation domain 9aaTAD none of the previously reported activation domains had considerable transactivation potential and were not involved in the activation of transcription. Our results demonstrated that the 9aaTAD domain is the only decisive activation domain in the Gal4 protein. We found that the artificial peptides included in the original Gal4 constructs were results of an unintended consequence of cloning that were responsible for the artificial transcriptional activity. Importantly, the activation domain 9aaTAD, which is the exclusive activation domain in Gal4, is also the central part of a conserved sequence recognized by the inhibitory protein Gal80. We propose a revision of the Gal4 regulation, in which the activation domain 9aaTAD is directly linked to both activation function and Gal80 mediated inhibition.</p></div

p53 9aaTADs activate transcription as small peptides.

<p>The predicted 9aaTADs in p53 from different species were tested for activation of transcription in LexA hybrid constructs. Similarity of p53 with Gal4 and Sox18 are highlighted. The construct 9p53, labelled with asterisk, has lower expression level compared with other constructs (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0162842#pone.0162842.s001" target="_blank">S1 Fig</a>). Animal picture from Flickr: Lowland Streaked Tenrec, Mantadia, Madagascar, Author: Frank Vassen; Elephant, Author: Jon Mountjoy; Igel (Hedgehog), Author: Mi chaela. All pictures have Creative Commons Attribution 2.0 Generic license.</p

Functional and non-functional activation domains in Gal4 activator.

<p>The Gal4—LexA hybrid constructs (BTM116 backbone) were assayed in L40 strain for activation of transcription. To distinguish activity of the N- and C-terminal activation domains in the Gal4 protein, a set of the Gal4 constructs were generated. The average value of the β-galactosidase activities from three independent experiments is presented as a percentage of the reference with standard deviation (means and plusmn; SD; n = 3). We standardized all results to previously reported Gal4 construct HaY including merely the activation domain 9aaTAD with the activity set to 100% [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0169261#pone.0169261.ref034" target="_blank">34</a>]. The LexA is <i>E</i>.<i>coli</i> DNA binding domain and the Gal4 DBD is <i>S</i>.<i>cerevisiae</i> Gal4 DNA binding domain, both generally used for the generation of fusion hybrids. The regions of Gal4 protein in the constructs are noted and graphically presented. Single dot means end of protein sequence, tree points mean continuing of the sequence, which is no more shown.</p

p53 9aaTAD-I is sufficient for interaction with the KIX domain.

<p>Interaction of the KIX domain with the p53 9aaTAD-I without its proximal Leucine in pull down experiment was monitored by western blotting. The purity of GST-KIX protein was monitored by SDS-PAGE.</p

In vivo study of radioprotective effect of NO-synthase inhibitors and acetyl-L-carnitine

In vivo study of radiprotective effect of NO-synthase inhibitors and acetyl-L-carnitine This study investigated the protective effect of two nitric oxide synthase inhibitors N(omega)-Nitro-Larginine methyl ester (L-NAME, 100 mg/kg i.p.) and aminoguanidine (AG, 400 mg/kg i.p.), and an antioxidant acetyl-L-carnitine (ALC, 250 mg/kg i.p., once daily for five days) against radiation-induced damage in Wistar rats. Blood samples were collected 6 hrs after whole-body irradiation with 8 Gy. Plasma concentrations of nitrite+nitrate (NOx) and malondialdehyde (MDA) were measured by highperformance liquid chromatography. A single injection of L-NAME one hour before exposure effectively prevented the radiation-induced elevation of plasma NOx and it reduced 2.6-fold the risk for death during the subsequent 30-day period. Pretreatment with ALC prevented the radiation-induced increase in plasma MDA and it had similar effect on mortality as L-NAME did. Presumably due to its short half-life, the partially iNOS-selective inhibitor and antioxidant AG given in a single dose before exposure did not attenuate MDA and NOx and it failed to significantly improve the 30-day survival. In conclusion, pretreatment with both the nonspecific NOS inhibitor L-NAME and the antioxidant ALC markedly reduce mortality to radiation sickness in rats. The radioprotective effect may be directly related to effective attenuation of the radiation-induced elevation of NO production by L-NAME and of oxidative stress by ALC. Key words: acetyl-L-carnitine; aminoguanidine; ionizing radiation; N(omega)-Nitro-L-arginine methyl este

Predicted 9aaTADs in Msn2 family.

<p>Prediction result for 9aaTADs in Msn2 and Msn4 activators retrieved by our 9aaTAD prediction algorithms. The conservation and variability of the 9aaTADs in the Msn2 and Gal4 families are shown.</p

Schema of the Gal4 regulation.

<p>Competition of Gal4 inhibitor Gal80 with mediators of transcription for the 9aaTAD domain. The peptides from <i>S</i>.<i>c</i>.Gal4 and <i>K</i>.<i>l</i>.Gal9 (Gal4 ortholog) interacting with Gal80 are shown (structural data for peptides interaction at PDB accession code 3E1K and 3BTS). The positions of activation domains 9aaTAD in the Gal80 binding peptides are highlighted (14 amino acid long Gal4 region is needed for maximal activation of transcription, construct H577, including the nine amino acid long 9aaTAD motif and four adjacent amino acids to the N-terminus and one to the C-terminus of the activation domain 9aaTAD). The artificial activation domains AD-I, AD-II and AD-III are not more shown in this figure.</p