OBJECTIVETo investigate the autophagy of effector cells in lung tissue at different time points when rats were exposed to free SiO2 dust.

METHODSSixty Wistar rats (220∼230 g) were selected and allocated to experimental group (n = 30) and control group (n = 30). In the experimental group, a rat silicosis model was established by infusing SiO2 suspension into the trachea of rats. Six rats in each group were sacrificed on days 1, 7, 14, 21, or 28 of dust exposure. Lung tissue samples were collected to prepare lung tissue sections. The pulmonary inflammation and fibrosis were observed by HE staining. The proautophagosome, autophagosome, and autophagolysosome in lung tissue sections were observed under a transmission electron microscope.

RESULTSOn day 1 of dust exposure, many proautophagosomes and autophagosomes were seen in both experimental group and control group. On day 7 of dust exposure, the experimental group had more autophagosomes in lung tissue than the control group. On day 14 of dust exposure, the experimental group had fewer autophagosomes than the control group. On days 21 and 28, autophagolysosomes were seen in macrophage plasma in both experimental group and control group; the autophagolysosomes in experimental group showed cloudy swelling and expansion, and some were vacuolated, and these changes were more significant on day 28.

CONCLUSIONFree SiO2 dust can induce autophagy in the lung tissue of rats, with varying degrees at different time points of dust exposure.

Animals ; Autophagy ; drug effects ; Dust ; Lung ; drug effects ; pathology ; Male ; Rats ; Rats, Wistar ; Silicon Dioxide ; toxicity

Animals ; Apoptosis/drug effects* ; Autophagy/drug effects* ; Carnitine/pharmacology* ; Cells, Cultured ; Endothelial Cells ; Lipopolysaccharides ; Mice

To explore the effects of miR-21 on macrophage autophagy, proliferation and apoptosis induced by cigarette smoke extract (CSE).
 Methods: The cells was divided into a control group, a CSE interventine macrophage group (CSE group), and a miR-21 inhibitor+CSE intervention macrophage group (miR-21 inhibitor+CSE group). The expression of miR-21 in the 3 groups was detected by real-time PCR. The effects of miR-21 inhibitor on macrophage autophagy, proliferation and apoptosis were detected by Western blot, MTT assay and flow cytometry.
 Results: Compared with the control group, the levels of miR-21 and autophagy in the CSE group were significantly increased (both P<0.05). The expression of miR-21 in the miR-21 inhibitor+CSE group was significantly lower than that in the CSE group (P<0.05). Compared with the control group, the expressions of macrophage microtubule associated protein 1 light chain 3 alpha (LC3) and autophagy related 7 (ATG7) in the CSE group were increased, which was attenuated by miR-21 inhibitor. Compared with the control group, the macrophage proliferation in the CSE group was inhibited by the miR-21, which could be reversed by adding miR-21 inhibitor; the proliferative rates in the miR-21 inhibitor+CSE group in 2, 3 or 4 days were increased by 1.41, 1.54 or 1.70 times compared with those in the CSE group (all P<0.05). Flow cytometry showed that the apoptosis rate in the control group was (2.57+1.35)%, which was (18.70+2.16)% in the CSE group and (6.28+1.08)% in the miR-21 inhibitor+CSE group (P<0.05).
 Conclusion: CSE intervention macrophage increase the autophagy and apoptosis of macrophages, decrease the cell proliferation by affecting the expression of miR-21 and the level of autophagy in macrophages.
Apoptosis ; drug effects ; Autophagy ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Gene Expression Regulation ; drug effects ; Macrophages ; drug effects ; MicroRNAs ; pharmacology ; Smoke

OBJECTIVETo explore the role of autophagy in doxorubicin (DOX)-induced resistance of human myeloma cell line RPMI8226.

METHODSWe established doxorubicin induced resistant subline of myeloma cell line RPMI8226/DOX by drug concentration step-elevation method. Resistant index of DOX was measured by MTT assay. Autophagy of myeloma cell lines RPMI8226/s and RPMI8226/DOX was detected by transmission electron microscopy, immunofluorescence (LC3-FITC) and western blot respectively. Apoptosis of RPMI8226/DOX cells induced by DOX combined with autophagic inhibitor hydroxychloroquine or 3-MA was identified by AnnexinV-FITC/PI double fluorescence dyeing.

RESULTSResistant index of RPMI8226/DOX was approximately 10.8 fold of that of RPMI8226/S. Electron microscopic studies revealed that most of RPMI8226/DOX cells displayed viable attributes and contained numerous autophagic vacuoles. Fluorescent images of RPMI8226/DOX cells showed a punctuate distribution in LC3 protein. Increased LC3-II protein in RPMI8226/DOX cells was determined by immunoblotting. There were no differences among 8 μmol/L HCQ (3.24±1.08)%, 10 mmol/L 3-MA (2.81±0.80)% or control \[(2.12±1.24)%\] (P>0.05) in terms of AnnexinV-FITC/PI double fluorescence dyeing; Compared with apoptosis of (9.75±2.15)%, (24.36±2.16)% and (40.51±3.14)% of RPMI8226/DOX cells under 2, 4 and 6 μmol/L DOX, apoptosis increased significantly after 24 h incubation under 2, 4 and 6 μmol/L DOX combined with 8 μmol/L HCQ as of \[(16.56±1.89)%, (36.44±2.91)% and (62.68±3.75)%, respectively\], or under 2, 4 and 6 μmol/L DOX combined with 10 mmol/L 3-MA as of \[(15.47±1.85)%, (39.28±3.06)% and (55.46±4.07)%, respectively\] (P<0.05).

CONCLUSIONAutophagy was involved in doxorubicin-induced resistance of myeloma cell line RPMI8226, DOX resistance in myeloma cells was reversed partly by autophagy inhibitor hydroxychloroquine or 3-MA, and autophagy may be one of mechanisms for drug resistance.

Autophagy ; drug effects ; Cell Line, Tumor ; Doxorubicin ; pharmacology ; Drug Resistance, Neoplasm ; Humans ; Multiple Myeloma

BACKGROUNDMammalian target of rapamycin (mTOR) is involved in a caspase independent form of programmed cell death called autophagy. The aim of this research was to investigate the effects of rapamycin and 3-methyladenine (3-MA) on autophagy, proliferation, apoptosis, and cell-cycle parameters of rat bone marrow-derived endothelial progenitor cells (EPCs).

METHODSMononuclear cells isolated from rat bone marrow were treated with rapamycin (0.01, 0.1, 1, or 10 µg/L) or 3-MA (1.25, 2.5, 5, or 10 mmol/L) for 24 hours. Expression of the autophagy marker protein LC3-II was analyzed by Western blotting. Apoptosis and cell-cycle progression were analyzed by flow cytometry. Cell proliferation was measured using the MTT assay.

RESULTSRapamycin treatment of EPCs induced apoptosis and autophagy and inhibited proliferation and cell-cycle progression in a dose-dependent manner. Treatment with 5 mmol/L 3-MA promoted cell proliferation; in contrast, treatment with 10 mmol/L 3-MA promoted apoptosis and induced S-phase arrest.

CONCLUSIONSRapamycin treatment of EPCs induced apoptosis and autophagy. Low concentrations of 3-MA had no significant effect on the proliferation and apoptosis of EPCs; The 5 mmol/L group promoted cell proliferation, but had no effect on the apoptosis; the 10 mmol/L group inhibited the proliferation and promoted apoptosis through the cell cycle.

Adenine ; analogs & derivatives ; pharmacology ; Animals ; Apoptosis ; drug effects ; Autophagy ; drug effects ; Cell Cycle ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Rats ; Sirolimus ; pharmacology

Autophagy is a process of cytoplasmic degradation of endogenous proteins and organelles. Although its primary role is protective, it can also contribute to cell death. Recently, autophagy was found to play a role in the activation of host defense against intracellular pathogens. The aims of our study was to investigate whether host cell autophagy influences Toxoplasma gondii proliferation and whether autophagy inhibitors modulate cell survival. HeLa cells were infected with T. gondii with and without rapamycin treatment to induce autophagy. Lactate dehydrogenase assays showed that cell death was extensive at 36-48 hr after infection in cells treated with T. gondii with or without rapamycin. The autophagic markers, LC3 II and Beclin 1, were strongly expressed at 18-24 hr after exposure as shown by Western blotting and RT-PCR. However, the subsequent T. gondii proliferation suppressed autophagy at 36 hr post-infection. Pre-treatment with the autophagy inhibitor, 3-methyladenine (3-MA), down-regulated LC3 II and Beclin 1. The latter was also down-regulated by calpeptin, a calpain inhibitor. Monodansyl cadaverine (MDC) staining detected numerous autophagic vacuoles (AVs) at 18 hr post-infection. Ultrastructural observations showed T. gondii proliferation in parasitophorous vacuoles (PVs) coinciding with a decline in the numbers of AVs by 18 hr. FACS analysis failed to confirm the presence of cell apoptosis after exposure to T. gondii and rapamycin. We concluded that T. gondii proliferation may inhibit host cell autophagy and has an impact on cell survival.
Anti-Bacterial Agents/pharmacology ; Apoptosis/drug effects/physiology ; Autophagy/drug effects ; HeLa Cells ; Humans ; Sirolimus/pharmacology ; Toxoplasma/*cytology/*physiology

OBJECTIVETo determine whether or not enterovirus 71 (enteroviurs 71, EV71) may induce autophagy and affect the production and release of EV71 after the treatment of autophagy inhibitor.

METHODSWestern blots were performed to examine the conversion of LC3-I to LC3- II and the degradation of P62 after the RD-A cells were infected with EV71. CCID50 was determined by checking the virus titer in the supernatant of cells that treated with autophagy inhibitor 3-MA.

RESULTSEV71 infection enhances the type conversion of LC3 and degradation of P62. The infectious virus particles were decreased after the treatment of 3-MA.

CONCLUSIONEV71 infection could induce cell autophagy and the autophagy might contribute to the production and release of infectious EV71 particles.

Adenine ; analogs & derivatives ; pharmacology ; Antiviral Agents ; pharmacology ; Autophagy ; drug effects ; Cell Line, Tumor ; Enterovirus ; drug effects ; Humans

This paper aimed to study the protective effect of ginsenoside Rg_1 on endotoxin(LPS)-induced apoptosis of lung epithelial cells and its mechanism of action. Mouse lung epithelial cells(MLE-12) were first treated with LPS. The autophagy changes and apoptosis and the relationship with concentration and time of LPS were observed. Then,the level of autophagy in MLE-12 was regulated at a specific concentration and action time of LPS,and the changes of apoptosis were observed. Secondly,ginsenoside Rg_1 and autophagy inhibitor 3-MA were added respectively at the same concentration and action time of LPS. The lung epithelial cells were grouped to observe the effect of ginsenoside Rg_1 on LPS-induced apoptosis of lung epithelial cells and its mechanism. In the animal experiment,the mice were grouped and tested by apoptosis protein,lung injury score and HE staining section to verify whether ginsenoside Rg_1 has a protective effect on LPS-induced lung injury. The results showed that apoptosis and autophagy increased as the rise of concentration after treatment with LPS for 12 h. The apoptosis increased gradually,and the autophagy increased first and then decreased over time at the LPS concentration of 25 g·L-1. The apoptosis of LPS group was higher than that of control group,and LPS+3-MA group increased further,while apoptosis decreased significantly in LPS+RAM(rapamycin,autophagy promoter) group. The autophagy increased in LPS group,decreased in LPS+3-MA group and increased in LPS+RAM group. The apoptosis of LPS group was higher than that of control group,and the apoptosis of LPS+Rg_1 group decreased. The apoptosis of LPS+Rg_1+3-MA group increased again. The autophagy of LPS group further increased after administration of ginsenoside Rg_1,but decreased after administration of 3-MA. In the in vivo experiments in mice,the apoptosis of LPS group increased significantly compared with the control group,while LPS + ginsenoside Rg_1 group decreased. Lung injury score and HE staining also conformed to the above trend. LPS can induce the apoptosis of lung epithelial cells in a time-dependent and concentration-dependent manner. The autophagy of lung epithelial cells increases with the rise of LPS concentration. At the specific concentration of LPS,autophagy increases first and then decreases after 12-16 hours. Proper increase of autophagy in lung epithelial cells within a certain period of time can reduce the apoptosis induced by LPS,while inhibition of autophagy can increase apoptosis. Ginsenoside Rg_1 has a protective effect on lung cancer epithelial cell apoptosis induced by autophagy.
Animals ; Apoptosis ; Autophagy ; Cells, Cultured ; Epithelial Cells ; drug effects ; Ginsenosides ; pharmacology ; Lipopolysaccharides ; Lung ; cytology ; Mice

OBJECTIVETo investigate the effect of bafilomycin A1 (BAF) on the cell proliferation, invasiveness, apoptosis, and oxaliplatin sensitivity in gastric cancer MGC-803 cells.

METHODSMGC-803 cells were divided into control group, BAF group, oxaliplatin group, and BAFµ oxaliplatin group. MTT assay and plate clone formation assay were used to assess the viability and colony forming ability of the cells after the treatments. The expression of nucleosomes in the cells was examined with ELISA. The cell migration and invasion after the treatments were evaluated. Western blotting was performed to detect the expression of Bcl-2 and Bax in the treated cells, and scanning electron microscopy, immunohistochemistry and Western blotting were employed to to observe the cell autophagy.

RESULTSCompared with the control cells, the cells treated with BAF showed a substantial decrease in autophagosome accumulation with attenuated cell proliferation, migration and invasion. Compared with cells treated with oxaliplatin alone, the cells treated with both BAF and oxaliplatin showed significantly lowered autophagosome accumulation, suppressed cell proliferation, migration and invasion, increased cell apoptosis, increased Bax expression and lowered Bcl-2 expression.

CONCLUSIONBAF can inhibit the proliferation and invasiveness of MGC-803 cells, promote cell apoptosis by inhibiting autophagy, and enhances the sensitivity of the cells to oxaliplatin.

Apoptosis ; Autophagy ; Cell Line, Tumor ; drug effects ; Cell Movement ; Cell Proliferation ; drug effects ; Drug Resistance, Neoplasm ; drug effects ; Humans ; Macrolides ; pharmacology ; Organoplatinum Compounds ; pharmacology ; Stomach Neoplasms ; pathology

As a major active component extracted from traditional Chinese herb Tripterygium wilfordii Hook F, triptolide exhibits multiple pharmacological effects. Autophagy is an evolutionary conserved intracellular catabolic process involved in cytoplasmic materials degradation. Autophagic dysfunction contributes to the pathologies of many human diseases, which makes it a promising therapeutic target. Recent studies have shown that triptolide exerts neuroprotection, anti-tumor activities, organ toxicity, and podocyte protection by modulating autophagy. This article highlights the current information on triptolide-modulated autophagy, analyzes the possible pathways involved, and describes the crosstalk between autophagy and apoptosis modulated by triptolide, in hope of providing implications for the roles of autophagy in pharmacological effects of triptolide and expanding its novel usage as an autophagy modulator.
Animals ; Apoptosis ; drug effects ; Autophagy ; drug effects ; Diterpenes ; pharmacology ; Epoxy Compounds ; pharmacology ; Humans ; Neoplasms ; drug therapy ; pathology ; Neuroprotective Agents ; pharmacology ; Phenanthrenes ; pharmacology ; Podocytes ; drug effects