ABSTRACT
@#The aim of this study was to synthesize and evaluate the necrosis avidity of MRI contrast agent based on rhein and linked by ether. The novel ligand 10-{［6-(1, 8-dihydroxyanthraquinone-3-carboxamido)ethoxyethyl］amino}carbonylmethyl-1, 4, 7, 10-tetraazacyclododecan-1, 4, 7-triacetic acid(DO3A-Ether-Rhein, E1)was synthesized by two steps of acylation and deprotection reaction. The paramagnetic gadolinium 10-{［6-(1, 8-dihydroxyanthraquinone-3-carboxamido)ethoxyethyl］amino}carbonylmethyl-1, 4, 7, 10-tetraazacyclododecan-1, 4, 7-triacetic acid(Gd-DO3A-Ether-Rhein, GdE1)was obtained by coordination of Gd3+ with the above ligand. We examined the necrotic avidity of GdE1 in human hepatocellular carcinoma HepG2 cell necrosis induced by hyperthermia in vitro and in rat model with muscular necrosis induced by microwave ablation in vivo by MRI. The MRI was implemented before administration of GdE1 and during 0-9 h after administration of GdE1(0. 1 mmol/kg), and Gd-DOTA(gadolinium 1, 4, 7, 10-tetraacetic acid-1, 4, 7, 10-tetraazacyclo dodecane)was used as control. The signal intensity of necrotic cells(4 369±70)was significantly higher than that of normal cells(2 555±84)(P< 0. 05). Similarly, the contrast ratio between necrotic and normal muscle at 3 h after administration of GdE1(2. 00±0. 12)was remarkblely higher than that at 0 h after administration of GdE1(1. 27±0. 03)(P< 0. 05). Therefore, GdE1 presents good necrosis affinity and has the potential to be used in the diagnosis of necrosis-related diseases.
ABSTRACT
Cell death plays important roles in living organisms and is a hallmark of numerous disorders such as cardiovascular diseases, sepsis and acute pancreatitis. Moreover, cell death also plays a pivotal role in the treatment of certain diseases, for example, cancer. Noninvasive visualization of cell death contributes to gained insight into diseases, development of individualized treatment plans, evaluation of treatment responses, and prediction of patient prognosis. On the other hand, cell death can also be targeted for the treatment of diseases. Although there are many ways for a cell to die, only apoptosis and necrosis have been extensively studied in terms of cell death related theranostics. This review mainly focuses on molecular imaging and therapeutic strategies directed against necrosis. Necrosis shares common morphological characteristics including the rupture of cell membrane integrity and release of cellular contents, which provide potential biomarkers for visualization of necrosis and necrosis targeted therapy. In the present review, we summarize the updated joint efforts to develop molecular imaging probes and therapeutic strategies targeting the biomarkers exposed by necrotic cells. Moreover, we also discuss the challenges in developing necrosis imaging probes and propose several biomarkers of necrosis that deserve to be explored in future imaging and therapy research.
ABSTRACT
@#In order to investigate the therapeutic effects of scutellarein on acute pharyngitis, 60 rats were randomly divided into five groups: blank group, model group, low-dose scutellarein group, high-dose scutellarein group and positive drug group. HE staining, blood-cell-analyzer, IL-6, IL-1β and TNF-α ELISA kit were used to study the effects of scutellarein on acute pharyngitis in pharyngeal tissue morphology, the counts of white blood cells and neutrophil and the serum concentrations of TNF-α, IL-1β and IL-6. Meanwhile, forty mice were randomly divided into four groups: blank group, low-dose scutellarein group, high-dose scutellarein group and positive drug group. Then, hot plate and writhing test of mice were carried out to study the analgesic effects of scutellarein. Results showed that, compared to the model group, scutellarein improved the physical status of acute pharyngitis rats, reduced the number of white blood cells significantly(P< 0. 05)and decreased the number of neutrophils and the levels of TNF-α, IL-1β and IL-6 in rats serum significantly(P< 0. 01). Meanwhile, scutellarein dramatically improved the pain threshold in hot plate test and decreased the number of writhing mice(P< 0. 01). It can be concluded that scutellarein can be used to treat acute pharyngitis with its anti-inflammatory and analgesic effect.
ABSTRACT
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.