131I-Evans blue: evaluation of necrosis targeting property and preliminary assessment of the mechanism in animal models.

Necrosis is a form of cell death, which is related to various serious diseases such as cardiovascular disease, cancer, and neurodegeneration. Necrosis-avid agents (NAAs) selectively accumulated in the necrotic tissues can be used for imaging and/or therapy of related diseases. The aim of this study was to preliminarily investigate necrosis avidity of 131I-evans blue (131I-EB) and its mechanism. The biodistribution of 131I-EB at 24 h after intravenous administration showed that the radioactivity ratio of necrotic to viable tissue was 3.41 in the liver and 11.82 in the muscle as determined by γ counting in model rats. Autoradiography and histological staining displayed preferential uptake of 131I-EB in necrotic tissues. In vitro nuclear extracts from necrotic cells exhibited 82.3% of the uptake in nuclei at 15 min, as well as 79.2% of the uptake at 2 h after 131I-EB incubation. The DNA binding study demonstrated that evans blue (EB) has strong binding affinity with calf-thymus DNA (CT-DNA) (Ksv=5.08×105 L/(mol/L)). Furthermore, the accumulation of 131I-EB in necrotic muscle was efficiently blocked by an excess amount of unlabeled EB. In conclusion, 131I-EB can not only detect necrosis by binding the DNA released from necrotic cells, but also image necrotic tissues generated from the disease clinically.

I-Evans blue: evaluation of necrosis targeting property and preliminary assessment of the mechanism in animal models

Necrosis is a form of cell death, which is related to various serious diseases such as cardiovascular disease, cancer, and neurodegeneration. Necrosis-avid agents (NAAs) selectively accumulated in the necrotic tissues can be used for imaging and/or therapy of related diseases. The aim of this study was to preliminarily investigate necrosis avidity of I-evans blue (I-EB) and its mechanism. The biodistribution of I-EB at 24 h after intravenous administration showed that the radioactivity ratio of necrotic to viable tissue was 3.41 in the liver and 11.82 in the muscle as determined by counting in model rats. Autoradiography and histological staining displayed preferential uptake of I-EB in necrotic tissues. nuclear extracts from necrotic cells exhibited 82.3% of the uptake in nuclei at 15 min, as well as 79.2% of the uptake at 2 h after I-EB incubation. The DNA binding study demonstrated that evans blue (EB) has strong binding affinity with calf-thymus DNA (CT-DNA) (=5.08×10 L/(mol/L)). Furthermore, the accumulation of I-EB in necrotic muscle was efficiently blocked by an excess amount of unlabeled EB. In conclusion, I-EB can not only detect necrosis by binding the DNA released from necrotic cells, but also image necrotic tissues generated from the disease clinically.

Temperature and osmotic stress dependence of the thermodynamics for binding linker histone H10, Its carboxyl domain (H10-C) or globular domain (H10-G) to B-DNA.

Linker histones (H1) are the basic proteins in higher eukaryotes that are responsible for the final condensation of chromatin. In contrast to the nucleosome core histone proteins, the role of H1 in compacting DNA is not clearly understood. In this study ITC was used to measure the binding constant, enthalpy change, and binding site size for the interactions of H10, or its C-terminal (H10-C) and globular (H10-G) domains to highly polymerized calf-thymus DNA at temperatures from 288 K to 308 K. Heat capacity changes, ΔCp, for these same H10 binding interactions were estimated from the temperature dependence of the enthalpy changes. The enthalpy changes for binding H10, H10-C, or H10-G to CT-DNA are all endothermic at 298 K, becoming more exothermic as the temperature is increased. The ΔH for binding H10-G to CT-DNA is exothermic at temperatures above approximately 300 K. Osmotic stress experiments indicate that the binding of H10 is accompanied by the release of approximately 35 water molecules. We estimate from our naked DNA titration results that the binding of the H10 to the nucleosome places the H10 protein in close contact with approximately 41 DNA bp. The breakdown is that the H10 carboxyl terminus interacts with 28 bp of linker DNA on one side of the nucleosome, the H10 globular domain binds directly to 7 bp of core DNA, and shields another 6 linker DNA bases, 3 bp on either side of the nucleosome where the linker DNA exits the nucleosome core.

1-Amino-4-hydroxy-9,10-anthraquinone - An analogue of anthracycline anticancer drugs, interacts with DNA and induces apoptosis in human MDA-MB-231 breast adinocarcinoma cells: Evaluation of structure-activity relationship using computational, spectroscopic and biochemical studies.

The X-ray diffraction and spectroscopic properties of 1-amino-4-hydroxy-9,10-anthraquinone (1-AHAQ), a simple analogue of anthracycline chemotherapeutic drugs were studied by adopting experimental and computational methods. The optimized geometrical parameters obtained from computational methods were compared with the results of X-ray diffraction analysis and the two were found to be in reasonably good agreement. X-ray diffraction study, Density Functional Theory (DFT) and natural bond orbital (NBO) analysis indicated two types of hydrogen bonds in the molecule. The IR spectra of 1-AHAQ were studied by Vibrational Energy Distribution Analysis (VEDA) using potential energy distribution (PED) analysis. The electronic spectra were studied by TDDFT computation and compared with the experimental results. Experimental and theoretical results corroborated each other to a fair extent. To understand the biological efficacy of 1-AHAQ, it was allowed to interact with calf thymus DNA and human breast adino-carcinoma cell MDA-MB-231. It was found that the molecule induces apoptosis in this adinocarcinoma cell, with little, if any, cytotoxic effect in HBL-100 normal breast epithelial cell.