Synthesis of New Branched 2‑Nitroimidazole as a Hypoxia Sensitive Linker for Ligand-Targeted Drugs of Paclitaxel

Because of the low selectivity and efficiency of normal antitumor agents, the strategy of ligand-targeted drugs was put forward. In this paper, we designed and synthesized a new bioreductive linker based on 2-nitroimidazole, which was used in three paclitaxel (PTX) prodrugs. The drug release mechanism via six-membered ring was demonstrated by chemical reduction and nitroreductase assay. Glucose and acetazolamide, which have been reported widely as ligands, were attached to compound <b>7</b> to afford Glu-PTX and AZO-PTX. The prodrugs were considerably stable in phosphate-buffered saline (pH 7.4) and plasma. What is more, PTX releasing could be triggered by nitroreductase rapidly. In in vitro cytotoxicity assay, the prodrugs exhibited moderate selectivity toward hypoxic tumor cells. We considered that the 2-nitroimidazole linker could accelerate the release of prodrugs under hypoxic condition. It was promising in the development of ligand-targeted drugs

Additional file 2 of Development of a novel immune-related lncRNA prognostic signature for patients with hepatocellular carcinoma

Additional file 2: Supplementary Table 2. 76 prognostic associated lncRNAs

Additional file 3 of Development of a novel immune-related lncRNA prognostic signature for patients with hepatocellular carcinoma

Additional file 3: Supplementary Figure 1. (A) The best-fit OS-related lncRNAs were chosen by Lasso regression analysis. (B) The Lasso regression was performed with the optimal value of λ. (C-D) Distribution of risk scores, survival status. Supplementary Figure 2. (A-D) PCA among all genes, immune genes, immune LncRNA, and risk immune LncRNA

Additional file 4 of Development of a novel immune-related lncRNA prognostic signature for patients with hepatocellular carcinoma

Additional file 4: Supplementary Table 3. All the primer sequences

Additional file 1 of Development of a novel immune-related lncRNA prognostic signature for patients with hepatocellular carcinoma

Additional file 1: Table 1. Clinical characteristics of hepatocellular carcinoma in train and validation cohort

Synthesis and Biological Evaluation of Paclitaxel and Camptothecin Prodrugs on the Basis of 2‑Nitroimidazole

Due to the low esterase activity in human plasma, many ester and carbonate prodrugs tested in humans may be less effective than that in preclinical animals. In this letter, PTX and SN-38 were attached to the <i>N</i>-1 position of 2-nitroimidazole via a carbonate linker. Presumably, 2-aminoimidazole may help promote the intramolecular hydrolysis of the carbonate bond. The prodrugs exhibited a considerable stability in buffers at different pH values as well as in human plasma. Furthermore, a rapid reduction was exhibited in the presence of nitroreductase. An <i>in vitro</i> cytotoxicity assay demonstrated that hypoxic conditions could increase the toxicity of prodrugs. Potentially, the compound species may form a new class of promising antitumor agents

Tongxinluo attenuates reperfusion injury in diabetic hearts by angiopoietin-like 4-mediated protection of endothelial barrier integrity via PPAR-α pathway

<div><p>Objective</p><p>Endothelial barrier function in the onset and Tongxinluo (TXL) protection of myocardial ischemia/reperfusion (I/R) injury, and TXL can induce the secretion of Angiopoietin-like 4 (Angptl4) in human cardiac microvascular endothelial cells during hypoxia/reoxygenation. We intend to demonstrate whether TXL can attenuate myocardial I/R injury in diabetes, characterized with microvascular endothelial barrier disruption, by induction of Angptl4-mediated protection of endothelial barrier integrity.</p><p>Methods and results</p><p>I/R injury was created by coronary ligation in ZDF diabetic and non-diabetic control rats. The animals were anesthetized and randomized to sham operation or I/R injury with or without the exposure to insulin, rhAngptl4, TXL, Angptl4 siRNA, and the PPAR-α inhibitor MK886. Tongxinluo, insulin and rhAngptl4 have the similar protective effect on diabetic hearts against I/R injury. In I/R-injured diabetic hearts, TXL treatment remarkably reduced the infarct size, and protected endothelial barrier integrity demonstrated by decreased endothelial cells apoptosis, microvascular permeability, and myocardial hemorrhage, fortified tight junction, and upregulated expression of JAM-A, integrin-α5, and VE-cadherin, and these effects of TXL were as effective as insulin and rhAngptl4. However, Angptl4 knock-down with siRNA interference and inhibition of PPAR-α with MK886 partially diminished these beneficial effects of TXL and rhAngptl4. TXL induced the expression of Angptl4 in I/R-injured diabetic hearts, and was canceled by Angptl4 siRNA and MK886. TXL treatment increased myocardial PPAR-α activity, and was abolished by MK886 but not by Angptl4 siRNA.</p><p>Conclusions</p><p>TXL protects diabetic hearts against I/R injury by activating Angptl4-mediated restoration of endothelial barrier integrity via the PPAR-α pathway.</p></div

Expression levels of JAM-A, VE-cadherin, and integrin-α5 in the I/R-injured hearts with or without TXL treatment.

<p>I/R injury decreased the expression levels of JAM-A (A), VE-cadherin (B), and Integrin-α5 (C). Pre-treatment with insulin, rhAngptl4, or TXL up-regulated expression levels of JAM-A (A), VE-cadherin (B), and Integrin-α5 (C). Addition of Angptl4 siRNA canceled the effects of TXL-induced up-regulation of JAM-A (A) and VE-cadherin (B), but not Integrin-α5 (C). Co-treatment with MK886 abolished the TXL-upregulated expression of JAM-A (A), VE-cadherin (B), and Integrin-α5 (C). Compared with DB-sham group, *<i>P</i><0.05, ** <i>P</i><0.01; Compared with the DB-MI group, ^†<i>P</i><0.05, ^††<i>P</i><0.01; Compared with the TXL group, ^‡<i>P</i><0.05, ^‡‡<i>P</i><0.01; Compared with the rhAngptl4+siR group, ^§§<i>P</i><0.01. Abbreviations as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0198403#pone.0198403.g001" target="_blank">Fig 1</a>.</p

Identification of endothelial cell apoptosis in the I/R-injured hearts treated with or without TXL by confocal microscopy.

<p>Endothelial cells were identified by red fluorescence (CD34), total cell number was detected by blue fluorescence (DAPI DNA staining), and apoptosis was detected by green fluorescence (TUNEL). Apoptotic endothelial cells were detected and counted by colocalized red and green (displayed as yellow). I/R injury induced significant ECs apoptosis in both MI control and diabetic MI rats (n = 8 in each group). Treatment with insulin, rhAngptl4 or TXL ameliorated ECs apoptosis compared with the diabetic MI controls. Whereas, co-treatment with Angptl4 siRNA partially blocked the beneficial effect of TXL. Administration of the PPARα inhibitor MK886 also reversed the inhibition effect of TXL on ECs apoptosis, but not reduce ECs apoptosis in the rhAngptl4-treated animals. Red arrows indicate endothelial cells and white arrows show apoptotic cells. Abbreviations as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0198403#pone.0198403.g001" target="_blank">Fig 1</a>.</p

Evaluation of intramyocardiac hemorrhage in the infarcted hearts treated with or without TXL.

<p>Sections of the hearts were stained with hematoxylin-eosin (n = 8 in each group). DB-sham group has no obvious extravasation of red blood cells in the interstitial space (A). I/R injury induced apparent extravasation of red blood cells into the interstitial space in both DB-MI (B) and non-DB-MI (C) groups. Treatment with insulin (D), rhAngptl4 (E) or TXL (F) greatly decreased extravasation of red blood cells. Combination with angptl4 siRNA canceled the effects of rhAngptl4 (I) and TXL (J). However, combination with MK886 abolished the effect of TXL (L) but not rhAngptl4 (K). Images were taken under a Leica microscope with 40×objective. Black arrows indicate intra-myocardiac hemorrhage. Abbreviations as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0198403#pone.0198403.g001" target="_blank">Fig 1</a>.</p