Aflatoxin B1 (AFB1) is a potent hepatocarcinogen in humans and exposure to AFB1 is known to cause both acute and chronic hepatocellular injury. As the liver is known to be the main target organ of aflatoxin, it is important to identify the key molecules that participate in AFB1-induced hepatotoxicity and to investigate their underlying mechanisms. In this study, the critical role of caveolin-1 in AFB1-induced hepatic cell apoptosis was examined. We found a decrease in cell viability and an increase in oxidation and apoptosis in human hepatocyte L02 cells after AFB1 exposure. In addition, the intracellular expression of caveolin-1 was increased in response to AFB1 treatment. Downregulation of caveolin-1 significantly alleviated AFB1-induced apoptosis and decreased cell viability, whereas overexpression of caveolin-1 reversed these effects. Further functional analysis showed that caveolin-1 participates in AFB1-induced oxidative stress through its interaction with Nrf2, leading to the downregulation of cellular antioxidant enzymes and the promotion of oxidative stress-induced apoptosis. In addition, caveolin-1 was found to regulate AFB1-induced autophagy. This finding was supported by the effect that caveolin-1 deficiency promoted autophagy after AFB1 treatment, leading to the inhibition of apoptosis, whereas overexpression of caveolin-1 inhibited autophagy and accelerated apoptosis. Interestingly, further investigation showed that caveolin-1 participates in AFB1-induced autophagy by regulating the EGFR/PI3K-AKT/mTOR signaling pathway. Taken together, our data reveal that caveolin-1 plays a crucial role in AFB1-induced hepatic cell apoptosis via the regulation of oxidation and autophagy, which provides a potential target for the development of novel treatments to combat AFB1 hepatotoxicity.

NORAD (non-coding RNA activated by DNA damage) is a long non-coding RNA (lncRNA) that is upregulated and promotes cell progression in various human types of cancer; however, its function in non-small cell lung cancer (NSCLC) remains unclear. The present study investigated the regulatory function and underlying mechanisms of NORAD in NSCLC. NORAD and miR-136-5p expression were assessed by reverse transcription-quantitative polymerase chain reaction, and proliferation and glycolysis-associated markers were also assessed. Direct miR-136-5p regulation by NORAD was detected using luciferase reporter assay and RNA immunoprecipitation. NORAD was highly expressed in NSCLC tissues and cell lines. NORAD overexpression increased NSCLC proliferation and glycolysis. Further investigation revealed that NORAD serves as a competing endogenous RNA for miR-136-5p. Gain- and loss-of-function experiments confirmed that miR-136-5p reversed the promoting effects of NORAD in NSCLC. Results of the present study indicate that NORAD serves as a growth-promoting lncRNA in NSCLC by suppressing the function of miR-136-5p. NORAD and miR-136-5p interaction may provide a potential target for NSCLC treatment.

In this review, we comprehensively summarize the fluorescent probes reported in the literature for all known kinds of chemical warfare agents (CWAs).

Hydrogen sulphide (H2S), the third endogenous gaseous signalling molecule, has attracted attention in biochemical research. The selective detection of H2S in living systems is essential for studying its functions. Fluorescence detection methods have become useful tools to explore the physiological roles of H2S because of their real-time and non-destructive characteristics. Herein we report a near-infrared fluorescent probe, NIR-HS, capable of tracking H2S in living organisms. With high sensitivity, good selectivity and low cytotoxicity, NIR-HS was able to recognize both the exogenous and endogenous H2S in living cells. More importantly, it realized the visualization of endogenous H2S generated in cells overexpressing cystathionine β-synthase (CBS), one of the enzymes responsible for producing endogenous H2S. The probe was also successfully applied to detect both the exogenous and endogenous H2S in living mice. The superior sensing properties of the probe render it a valuable research tool in the H2S-related medical research.

BackgroundSulfur mustard (SM) is a notorious chemical warfare agent that can cause severe acute lung injury (ALI), in addition to other lesions. Currently, effective medical countermeasures for SM are lacking. Bone marrow-derived mesenchymal stromal cells (BMSCs) possess self-renewal and multipotent differentiation capacity. BMSCs can also migrate to inflammation and injury sites and exert anti-inflammatory and tissue repair functions. Here, we report the curative effect of BMSCs on SM-induced ALI in a mouse model.MethodsMice BMSCs were injected into mice via the tail vein 24 h after SM exposure. The distribution of BMSCs in mice was detected by fluorescence imaging. The therapeutic potential of BMSCs was evaluated by the calculating survival rate. The effects of BMSCs on lung tissue injury and repair assessment were examined by staining with H&E and measuring the lung wet/dry weight ratio, BALF protein level, and respiratory function. The effects of BMSCs on the infiltration and phenotypic alteration of inflammatory cells were analyzed by immunohistochemistry and flow cytometry. The levels of chemokines and inflammatory cytokines were examined using the Luminex Performance Assay and ELISA. RNA interference, western blotting, and ELISA were applied to explore the role of the TLR4 signaling pathway in the anti-inflammatory effects of BMSCs. The extent of tissue repair was analyzed by ELISA, western blotting, and immunohistochemistry.ResultsFluorescence imaging indicated that the lung is the major target organ of BMSCs after injection. The injection of BMSCs significantly improved the survival rate (p < 0.05), respiratory function, and related lung damage indexes (wet/dry weight ratio, total proteins in BALF, etc.) in mice. BMSC administration also reduced the level of pro-inflammatory cytokines, chemokines, and inflammatory cell infiltration, as well as affected the balances of M1/M2 and Th17/Treg. Furthermore, solid evidence regarding the effects of BMSCs on the increased secretion of various growth factors, the differentiation of alveolar epithelial cells, and the enhancement of cell barrier functions was also observed.ConclusionBMSCs displayed protective effects against SM-induced ALI by alleviating inflammation and promoting tissue repair. The present study provides a strong experimental basis in a mouse model and suggests possible application for future cell therapy.Electronic supplementary materialThe online version of this article (10.1186/s13287-019-1189-x) contains supplementary material, which is available to authorized users.

As one of three gasotransmitters, the fundamental signalling roles of hydrogen sulphide are receiving increasing attention. New tools for the accurate detection of hydrogen sulphide in cells and tissues are in demand to probe its biological functions. We report the p-nitrobenzyl-based ratiometric fluorescent probe RHP-2, which features a low detection limit, high selectivity and good photostability. The emission intensity ratios had a good linear relationship with the sulphide concentrations in PBS buffer and bovine serum. Our probe was applied to the ratiometric determination and imaging of endogenous H2S in living cells. Furthermore, RHP-2 was used as an effective tool to measure endogenous H2S in the mouse hippocampus. We observed a significant reduction in sulphide concentrations and downregulated expression of cystathionine β-synthetase (CBS) mRNA and CBS protein in the mouse hippocampus in a chronic unpredictable mild stress (CUMS)-induced depression model. These data suggested that decreased concentrations of endogenous H2S may be involved in the pathogenesis of chronic stress depression.

Sulfur mustard (SM) is a chemical warfare agent and a terrorism choice that targets various organs and tissues, especially lung tissues. Its toxic effects are tightly associated with oxidative stress. The signaling molecule hydrogen sulfide (H2S) protects the lungs against oxidative stress and activates the NF-E2 p45-related factor 2 (Nrf2) pathway. Here, we sought to establish whether endogenous H2S plays a role in SM induced lesion in mouse lungs and lung cells and whether endogenous H2S plays the role through Nrf2 pathway to protect against SM-induced oxidative damage. Furthermore, we also explored whether activation of Nrf2 by H2S involves sulfhydration of Kelch-like ECH-associated protein-1 (Keap1). Using a mouse model of SM-induced lung injury, we demonstrated that SM-induced attenuation of the sulfide concentration was prevented by NaHS. Concomitantly, NaHS attenuates SM-induced oxidative stress. We also found that H2S enhanced Nrf2 nuclear translocation, and stimulated expression of Nrf2-targeted downstream protein and mRNA levels. Incubation of the lung cells with NaHS decreased SM-induced ROS production. Furthermore, we also found that H2S S-sulfhydrated Keap1, which induced Nrf2 dissociation from Keap1, and enhanced Nrf2 nuclear translocation. Our data indicate that H2S is a critical, however, being long neglected signal molecule in SM-induced lung injury.

Detection of cancer at its early stage is important for treatment. Urine, which is not regulated by homeostatic mechanisms, reflects early systemic changes throughout the whole body and can be used for the early detection of cancer. In this study, the Walker-256 tail-vein injection rat model was established to find whether the urine proteome could reflect early changes if tumor grown in lung. Urine samples from the control group (n = 7) and Walker-256 tail-vein injection group (n = 7) on days 2, 4, 6 and 9 were analyzed by label-free proteomic quantitative methods. On day 2, when lung tumor nodules did not appear, 62 differential proteins were identified. They were associated with epithelial cell differentiation, regulation of immune system processes and the classical complement activation pathway. On day 4, when lung tumor nodules appeared, 72 differential proteins were identified. They were associated with the innate immune response and positive regulation of phagocytosis. On day 6, when body weight began to decrease, 117 differential proteins were identified. On day 9, the identified 125 differential proteins were associated with the B cell receptor signaling pathway and the positive regulation of B cell activation. Our results indicate that (1) the urine proteome changed even on the second day after tail-vein injection of Walker-256 cells and that (2) compared to previous studies, the urine proteomes were different when the same cancer cells were grown in different organs.