Attribution of Bax and mitochondrial permeability transition pore on cantharidin-induced apoptosis of Sf9 cells

Effects of Long-Term Exposure to Copper on Mitochondria-Mediated Apoptosis in Pig Liver

Copper (Cu) is listed as one of the main heavy metal pollutants, which poses potential health risks to humans. Excessive intake of Cu has shown toxic effects on the organs of many animals, and the liver is one of the most important organs to metabolize it. In this study, pigs, the mammal with similar metabolic characteristics to humans, were selected to assess the effects of long-term exposure to Cu on mitochondria-mediated apoptosis, which are of great significance for studying the toxicity of Cu to humans. Pigs were fed a diet with different contents of Cu (10, 125, and 250 mg/kg) for 80 days. Samples of blood and liver tissue were collected on days 40 and 80. Experimental results demonstrated that the accumulation of Cu in the liver was increased in a dose-dependent and time-dependent manner. Meanwhile, the curve of pig's body weight showed that a 125 mg/kg Cu diet promoted the growth of pigs during the first 40 days and then inhibited it from 40 to 80 days, while the 250 mg/kg Cu diet inhibited the growth of pigs during 80 days of feeding. Additionally, the genes and protein expression levels of Caspase-3, p53, Bax, Bak1, Bid, Bad, CytC, and Drp1 in the treatment group were higher than that in the control group, while Bcl-2, Bcl-xL, Opa1, Mfn1, and Mfn2 were decreased. In conclusion, these results indicated that long-term excessive intake of Cu could inhibit the growth of pigs and induced mitochondria-mediated apoptosis by breaking the mitochondrial dynamic balance. Synopsis: Long-term exposure to high doses of Cu could lead to mitochondrial dysfunction by breaking the mitochondrial dynamic balance, which ultimately induced mitochondria-mediated apoptosis in the liver of pigs. This might be closely related to the growth inhibition and liver damage in pigs.

Insect Cell-Based Models: Cell Line Establishment and Application in Insecticide Screening and Toxicology Research

During the past decades, research on insect cell culture has grown tremendously. Thousands of lines have been established from different species of insect orders, originating from several tissue sources. These cell lines have often been employed in insect science research. In particular, they have played important roles in pest management, where they have been used as tools to evaluate the activity and explore the toxic mechanisms of insecticide candidate compounds. This review intends to first briefly summarize the progression of insect cell line establishment. Then, several recent studies based on insect cell lines coupled with advanced technologies are introduced. These investigations revealed that insect cell lines can be exploited as novel models with unique advantages such as increased efficiency and reduced cost compared with traditional insecticide research. Most notably, the insect cell line-based models provide a global and in-depth perspective to study the toxicology mechanisms of insecticides. However, challenges and limitations still exist, especially in the connection between in vitro activity and in vivo effectiveness. Despite all this, recent advances have suggested that insect cell line-based models promote the progress and sensible application of insecticides, which benefits pest management.

Cyclosporine A Regulates Influenza A Virus-induced Macrophages Polarization and Inflammatory Responses by Targeting Cyclophilin A

Cyclosporine A (CsA) is an immunosuppressive drug that suppresses T cell responses and is broadly used in transplantation. Its immunosuppressive action is closely linked to its binding of cyclophilin A (CypA), which widely distributed in different cell types. CsA also regulates the functions of innate immune cells, but the mechanism remains elusive. Here, we investigate the role of CsA in regulating macrophages polarization in influenza A virus-infected mice and mouse bone marrow-derived macrophages. CsA downregulates pro-inflammatory cytokines expression and upregulates anti-inflammatory cytokines expression. Mechanically, CsA decreases the polarization of macrophages into pro-inflammatory M1 phenotype and increases the polarization of macrophages into anti-inflammatory M2 phenotype. Further studies show that CsA regulates macrophages polarization-associated IFN-γ/STAT1 and IL-4/STAT6 signaling pathways. Meanwhile, all these roles of CsA are eliminated when CypA is absent, suggesting that CsA regulates macrophages polarization and inflammatory responses depend on its binding to CypA. Collectively, these results reveal a crucial mechanism of CsA in attenuating IAV-induced inflammatory responses by a switch in macrophages polarization.

Metabolomics analysis reveals the effects of copper on mitochondria-mediated apoptosis in kidney of broiler chicken (Gallus gallus)

Copper (Cu) is one of the ubiquitous environmental pollutants which have raised wide concerns about the potential toxic effects and public health threat. For deeply investigating the nephrotoxicity induced by Cu, the effects of Cu on mitochondria-mediated apoptosis in kidney were first to analyze by combining metabolomics and molecular biology techniques. In this study, broiler chicks were fed with different contents of Cu (11, 110, 220, and 330 mg/kg Cu) for 49 d. The results of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) staining and transmission electron microscope showed that Cu could induce apoptosis in kidney, characterized by the increasing of TUNEL-positive cells and mitochondrial vacuolation. Additionally, a total of 62 differential metabolites were detected by liquid chromatography-mass spectrometry (LC-MS), and mainly enriched in the metabolic pathways including riboflavin metabolism, glutathione metabolism, sphingolipid metabolism, and glycerophospholipid metabolism, which were closely to mitochondrial metabolism. Meanwhile, the decreased mitochondrial membrane potential (MMP), increased mitochondrial membrane permeability and the change of mRNA and protein expression levels associated with mitochondria-mediated apoptosis and mitochondrial dynamics confirmed that Cu could induce mitochondria-mediated apoptosis. Therefore, our results demonstrated that Cu induced mitochondria-mediated apoptosis in kidney. Moreover, this study highlighted the metabolic characteristics of Cu to kidney, which suggested that mitochondrial metabolism could be considered as an important factor influencing toxicity.

Insights into the modulatory role of cyclosporine A and its research advances in acute inflammation

Cyclosporine A(CsA), a classic immunosuppressant, is mainly applied for solid organ transplantation and some autoimmune diseases by suppressing T lymphocytes. Early studies showed that the application of CsA is primarily focused on chronic but not acute inflammation, nevertheless, increasing evidence supporting a role for CsA in acute inflammation, although most of proofs come from experimental models. It has long been known to us that the nuclear factor of activated T cells (NFAT) is the target of CsA to regulate T lymphocytes. However, NFAT also contributes to the regulation of innate immune cells, thus, CsA can not only target lymphocytes but also innate immune cells such as monocytes/macrophages, dendritic cells and neutrophils, which provides a basis for CsA to act on acute inflammation. Moreover, some other pathophysiological events in acute inflammation such as decreased vascular activity, mitochondrial dysfunction and endogenous cell apoptosis can also be alleviated by CsA. There being a moderate successes in the application of CsA for experimental acute inflammation such as sepsis, trauma/hemorrhagic shock and ischemic/reperfusion injury, yet data of the clinical treatment is not clear. In this review, we will critically analyze the existing hypotheses, summarize the application of CsA and its possible mechanisms in various acute inflammation over the past few decades, hope to provide some clues for the clinical treatment of acute inflammation.

Penehyclidine hydrochloride inhibits renal ischemia/reperfusion-induced acute lung injury by activating the Nrf2 pathway

The nuclear factor (NF)-κB and NOD-like receptor protein 3 (NLRP3) pathways promote inflammatory signaling that injures the kidneys, whereas the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway promotes anti-inflammatory signaling that inhibits oxidative damage. Penehyclidine hydrochloride (PHC) inhibits NF-κB and activates Nrf2 signaling. We investigated whether PHC induces communication between the Nrf2 and NF-κB/NLRP3 pathways, thereby protecting against renal ischemia/reperfusion (rI/R)-induced lung inflammation. Rat alveolar macrophages (NR8383 cells) were stimulated for 24 h with PHC with or without brusatol (a Nrf2 antagonist), after which they were treated for 4 h with tert-butyl hydroperoxide (10 mM). PHC Nrf2-dependently alleviated tert-butyl hydroperoxide-induced reactive oxygen species production in alveolar macrophages. Additionally, wild-type and Nrf2^-/- rats were each divided into four groups: (1) sham, (2) PHC (1 mg/kg), (3) rI/R and (4) rI/R + PHC (1 mg/kg). PHC markedly induced the Nrf2 and adenosine monophosphate-activated protein kinase pathways and suppressed rI/R-induced NF-κB and NLRP3 activation in the lungs. Nrf2 deficiency diminished the ability of PHC to ameliorate rI/R-induced histopathological alterations and reactive oxygen species release in the lungs; however, PHC inhibited NLRP3 signaling Nrf2-dependently, while it inhibited NF-κB signaling Nrf2-independently. Our findings demonstrate the beneficial effects of PHC on rI/R-induced lung inflammation.

Propofol post-conditioning lessens renal ischemia/reperfusion-induced acute lung injury associated with autophagy and apoptosis through MAPK signals in rats

Renal Ischemia/Reperfusion (rI/R)-induced acute lung injury (ALI) is a major problem in rI/R. The objective of the current study was to explore the defensive roles of propofol (Pro), an intravenous anesthetic, on rI/R-induced ALI through mitogen-activated protein kinase (MAPK) signaling. Rats were divided into Sham, Pro (10 mg/kg), rI/R, rI/R + Pro (5 mg/kg), and rI/R + Pro (10 mg/kg) groups. Rats were treated with Pro at 1 h after rI/R treatment. Serum and lung tissues at 24 h after rI/R were collected to evaluate morphological changes and the expression of myeloperoxidase (MPO), inflammatory cytokines, and crucial proteins in the MAPK pathway. Pro attenuated the production of mediators, resulting in reduced levels of autophagy and apoptosis by restricting the MAPK pathway in rI/R-induced ALI model. Pro represses rI/R-induced pulmonary autophagy and apoptosis by decreasing the production of inflammatory molecules, and the effects of Pro are involved in the inhibition of the MAPK pathway.

TNF Induces Pathogenic Programmed Macrophage Necrosis in Tuberculosis through a Mitochondrial-Lysosomal-Endoplasmic Reticulum Circuit

Necrosis of infected macrophages constitutes a critical pathogenetic event in tuberculosis by releasing mycobacteria into the growth-permissive extracellular environment. In zebrafish infected with Mycobacterium marinum or Mycobacterium tuberculosis, excess tumor necrosis factor triggers programmed necrosis of infected macrophages through the production of mitochondrial reactive oxygen species (ROS) and the participation of cyclophilin D, a component of the mitochondrial permeability transition pore. Here, we show that this necrosis pathway is not mitochondrion-intrinsic but results from an inter-organellar circuit initiating and culminating in the mitochondrion. Mitochondrial ROS induce production of lysosomal ceramide that ultimately activates the cytosolic protein BAX. BAX promotes calcium flow from the endoplasmic reticulum into the mitochondrion through ryanodine receptors, and the resultant mitochondrial calcium overload triggers cyclophilin-D-mediated necrosis. We identify ryanodine receptors and plasma membrane L-type calcium channels as druggable targets to intercept mitochondrial calcium overload and necrosis of mycobacterium-infected zebrafish and human macrophages.

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TNF induces mitochondrial ROS to cause necrosis of mycobacterium-infected macrophages

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Mitochondrial ROS activate lysosomal enzymes that lead to BAX activation

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BAX activates ER ryanodine receptors to cause Ca²⁺ flow into the mitochondrion

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Drugs preventing mitochondrial Ca²⁺ overload prevent pathogenic macrophage necrosis in TB

Harmine induced apoptosis in Spodoptera frugiperda Sf9 cells by activating the endogenous apoptotic pathways and inhibiting DNA topoisomerase I activity

Harmine, a useful botanical compound, has demonstrated insecticidal activity against some pests. However, harmine's mechanism of action has not been thoroughly elucidated to date. To preliminarily explore harmine's insecticidal mechanisms, the cytotoxicity of harmine against Spodoptera frugiperda Sf9 cells was comprehensively investigated. Our results indicated that harmine induced apoptosis in Sf9 cells, as evidenced by cellular and nuclear morphological changes, DNA laddering and increases in caspase-3-like activities. In addition, activation of the mitochondrial apoptotic pathway by harmine was confirmed by the generation of ROS, opening of mitochondrial permeability transition pores (MPTPs), increase in cytosolic Ca²⁺, changes in mRNA expression levels of genes involved in the mitochondrial apoptotic pathway and increase and release of Cytochrome c. Furthermore, lysosomal membrane permeabilization, release of cathepsin L from the lysosome into the cytosol and cleavage of caspase-3 were also triggered, which indicated that lysosomes were involved in this physiological process. Moreover, the effect of harmine on DNA topoisomerase I activity was investigated by in vivo and molecular docking experiments. These data not only verified that harmine induced apoptosis via comprehensive activation of the mitochondrial and lysosomal pathways and inhibition of DNA topoisomerase I activity in Sf9 cells but also revealed a mechanism of harmine insecticidal functions for pest control.