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This study aims to investigate how microRNA-375 (miR-375) improves immune function by regulating liver macrophages (Kupffer cells) in mice with liver failure. Forty mice were divided into ConA-1h, ConA-3h, ConA-6h, and control groups, with 10 mice in each group. Mice models of liver failure were established by injecting concanavalin A (ConA) solution via the tail veins of mice, and then primary Kupffer cells were isolated and cultured. Reverse transcription quantitative polymerase chain reaction, Western blot analysis, and enzyme-linked immunosorbent assay were conducted to examine the expressions of miR-375, astrocyte elevated gene-1 (AEG-1), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and IL-1β in Kupffer cells of mice with liver failure as well as after silencing of miR-375. Flow cytometry was used to determine cell apoptosis. During the liver failure process, miR-375, IL-6, TNF-α, and IL-1β expressions were increased over time, while AEG-1 expression decreased over time in the control, ConA-1h, ConA-3h, and ConA-6h groups. Opposite alternations were observed after silencing of miR-375. Dual-luciferase reporter gene assay showed that AEG-1 was a target gene of miR-375. Flow cytometry determination showed that the ratio of apoptotic Kupffer cells decreased after silencing of miR-375. Overexpression of AEG-1 could rescue the suppression of IL-6, TNF-α, and IL-1β expressions in Kupffer cells after the short-term induction of ConA and further inhibit cell apoptosis. Our study provides evidence that miR-375 could regulate Kupffer cells to improve immune function in mice with liver failure., (© 2018 Wiley Periodicals, Inc.)

Background: Saponins are a major active component for the traditional Chinese medicine, Rubus parvifolius L., which has shown clear antitumor activities. However, the specific effects and mechanisms of saponins of Rubus parvifolius L. (SRP) remain unclear with regard to human chronic myeloid leukemia cells. The aim of this study was to investigate inhibition of proliferation and apoptosis induction effects of SRP in K562 cells and further elucidate its regulatory mechanisms., Materials and Methods: K562 cells were treated with different concentrations of SRP and MTT assays were performed to determine cell viability. Apoptosis induction by SRP was determined with FACS and DAPI staining analysis. Western blotting was used to detect expression of apoptosis and survival related genes. Specific inhibitors were added to confirm roles of STAT3 and AMPK pathways in SRP induction of apoptosis., Results: Our results indicated that SRP exhibited obvious inhibitory effects on the growth of K562 cells, and significantly induced apoptosis. Cleavage of pro-apoptotic proteins was dramatically increased after SRP exposure. SRP treatment also increased the activities of AMPK and JNK pathways, and inhibited the phosphorylation expression level of STAT3 in K562 cells. Inhibition of the AMPK pathway blocked the activation of JNK by SRP, indicating that SRP regulated the expression of JNK dependent on the AMPK pathway. Furthermore, inhibition of the latter significantly conferred resistance to SRP pro- apoptotic activity, suggesting involvement of the AMPK pathway in induction of apoptosis. Pretreatment with a STAT3 inhibitor also augmented SRP induced growth inhibition and cell apoptosis, further confirming roles of the STAT3 pathway after SRP treatment., Conclusions: Our results demonstrated that SRP induce cell apoptosis through AMPK activation and STAT3 inhibition in K562 cells. This suggests the possibility of further developing SRP as an alternative treatment option, or perhaps using it as adjuvant chemotherapeutic agent for chronic myeloid leukemia therapy.

Cadmium (Cd), a ubiquitous environmental pollutant, is known to impair placental development. However, the underlying mechanisms remain unclear. The present study used in vivo and in vitro models to investigate the effects of Cd on apoptosis and autophagy in placental trophoblasts and its mechanism. Pregnant mice were exposed to CdCl 2 (4.5 mg/kg) on gestational day (GD) 9. Human JEG-3 cells were exposed to CdCl 2 (0–40 μM) for different time points. Gestational Cd exposure obviously lowered the weight and diameter of mouse placentas. Number of TUNEL-positive cells was markedly elevated in Cd-administered mouse placentas and JEG-3 cells. Correspondingly, Cd significantly up-regulated cleaved caspase-3 protein level, a key indicator of apoptosis, in murine placentas and JEG-3 cells. Simultaneously, Cd also triggered autophagy, as determined by an elevation of LC3B-II and p62 protein, and accumulation of LC3-positive puncta, in placental trophoblasts. Chloroquine an autophagy inhibitor, obviously aggravated Cd-induced apoptosis in JEG-3 cells. By contrast, rapamycin, a specific autophagy inducer, significantly alleviated Cd-triggered apoptosis in JEG-3 cells. Mechanistically, autophagy inhibited Cd-induced apoptosis mainly via degrading caspase-9. Co-localizations of p62, a classical autophagic receptor, and caspase-9 were observed in Cd-stimulated human JEG-3 cells. Moreover, p62 siRNAs pretreatment markedly blocked the degradation of caspase 9 proteins via Cd-activated autophagy in JEG-3 cells. Collectively, our data suggest that activation of autophagy inhibits Cd-induced apoptosis via p62-mediated caspase-9 degradation in placental trophoblasts. These findings provide a new mechanistic insight into Cd-induced impairments of placental and fetal development. Image 1 • Environmental Cd exposure during pregnancy causes apoptosis and autophagy in placental trophoblasts. • Autophagy activation inhibits Cd-triggered apoptosis in placental trophoblasts. • Autophagy activation inhibits Cd-triggered apoptosis via p62-mediated caspase-9 degradation in placental trophoblasts. Activation of autophagy inhibits Cd-induced apoptosis via p62-mediated caspase-9 degradation in placental trophoblasts. [ABSTRACT FROM AUTHOR]

Heavy metal cadmium (Cd), a classical environmental pollutant, causes placental apoptosis and fetal growth restriction (FGR), whereby the mechanism remains unclear. Here, our human case-control study firstly showed that there was a positive association of Parkin mitochondrial translocation, MCL-1 reduction, placental apoptosis, and all-cause FGR. Subsequently, Cd was administered to establish in vitro and in vivo models of placental apoptosis or FGR. Our models demonstrated that Parkin mitochondrial translocation was observed in Cd-administrated placental trophoblasts. Meaningfully, Parkin siRNA (siR) dramatically mitigated Cd-triggered apoptosis in placental trophoblasts. Mdivi-1 (M-1), an inhibitor for Parkin mitochondrial translocation, mitigated Cd-induced apoptosis in placental trophoblasts, which further ameliorated the effect of attenuated placental sizes in Cd-exposed mice. Furthermore, the interaction of MCL-1 with Parkin or Ub in Cd-stimulated cells was stronger than that in controls. MG132, an inhibitor for proteasome, abolished MCL-1 degradation in Cd-stimulated cells. Importantly, Parkin siR and M-1 memorably abolished the ubiquitin-dependent degradation of MCL-1 in placental trophoblasts. Interestingly, mito-TEMPO and melatonin, two mitochondria-targeted antioxidants, obviously rescued Cd-caused mitochondrial membrane potential (MMP) decrease, Parkin mitochondrial translocation, MCL-1 degradation, and apoptosis in placental trophoblasts. In conclusion, cadmium induces placental apoptosis and FGR via mtROS-mediated Parkin-modulated degradation of MCL-1. [Display omitted] • Parkin mitochondrial translocation and apoptosis occur in SGA placentae. • Cadmium promotes placental apoptosis via MCL-1 degradation. • Cadmium causes MCL-1 degradation by Parkin mitochondrial translocation. • Cadmium promotes Parkin mitochondrial translocation via mtROS release. [ABSTRACT FROM AUTHOR]