OBJECTIVE: To explore the mechanism by which berberine inhibits ferroptosis of mouse hippocampal neuronal cells (HT22). METHODS: Cultured HT22 cells were pretreated with 30 or 60 μmol/L berberine for 2 h before exposure to 0.5 μmol/L erastin for 8 h, and the cell proliferation, intracellular ferric iron level, changes in intracellular reactive oxygen species (ROS) and cell apoptosis were detected using CCK-8, Fe²⁺ fluorescent probe, fluorescent dye (DAPI) and fluorescent probe (H2DCFH-DA). RT-qPCR and Western blotting were used to detect the mRNA and protein expressions of Nrf2, HO-1 and GPX4 in the cells. We further tested the effects of treatments with 2 μmol/L ML385 (a Nrf2 inhibitor), 60 μmol/L berberine and erastin in the cells to explore the protective mechanism of berberine against erastin-induced ferroptosis in the neuronal cells. RESULTS: Treatment with 0.5 μmol/L erastin significantly lowered the viability of HT22 cells (P < 0.05) and increased the production of ROS, cell apoptosis rate and ferric iron level (P < 0.05). Pretreatment with 30 and 60 μmol/L berberine both significantly increased the vitality of erastin-exposed cells (P < 0.05) and lowered the levels of intracellular ROS and ferric iron content (P < 0.05). RT-qPCR and Western blotting showed that berberine obviously promoted the expressions of Nrf2, HO-1 and GPX4 in the cells (P < 0.05), and treatment with ML385 significantly inhibited the Nrf2-HO-1/GPX4 pathway, increased intracellular ROS and ferric iron contents and mitigated the protective effect of berberine against erastin-induced ferroptosis (P < 0.05). CONCLUSION Berberine can inhibit erastin-induced ferroptosis in HT22 cells possibly by activating the Nrf2-HO-1/ GPX4 pathway.
Animals ; Berberine/pharmacology* ; Ferroptosis ; Fluorescent Dyes ; Hippocampus/metabolism* ; Iron/metabolism* ; Mice ; NF-E2-Related Factor 2/metabolism* ; Piperazines ; Reactive Oxygen Species/metabolism*

Objective: To study the underlying mechanism of cadmium-induced apoptosis of mouse spermatocytes (GC-2 spd) . Methods: In March 2021, GC-2 spd cells were exposed to different concentrations of CdCl(2) for 24 hours, namely 5 μmol/L CdCl(2) (low-dose) group and 10 μmol/L CdCl(2) (high-dose) group, and unexposed GC-2 spd cells were used as control group. Mitochondrial morphology was observed in the cells stained with Mito-Track Red CMXRos fluorescent probes by confocal microscopy and the mitochrondrial membrane potential was measured by flow cytometry with JC-1 fluorescent probes. Mitochrondrial proteins, cytosolic proteins and total cellular proteins of GC-2 spd cells were extracted using cell mitochondria isolation kit and RIPA buffer, respectively. The expression of mitochondrial homeostasis regulatory proteins (FIS1 and OPA1), and apoptosis-related proteins (Cytochrome c and cleaved Caspase-3) were examined by Western blot. Results: Compared with the cells in the control group, the relative ratio of JC-1 red/green fluorescence signal in the cells of the low-dose and high-dose CdCl(2) groups decreased significantly (0.740±0.071, 0.570±0.028), with a statistically significant difference (P=0.017, 0.004) ; The morphology of mitochondria changed from long tube to point, and the proportion of cells containing point mitochondria increased significantly (45.1%±3.7% and 25.7%±4.9%), the difference was statistically significant (P=0.005, 0.001) ; The relative expression level of mitochondrial FIS1 in cells of low and high dose CdCl(2) groups was significantly higher (1.271±0.120, 1.693±0.155), the difference was statistically significant (P=0.046, 0.000) ; The relative expression level of OPA1 decreased significantly (0.838±0.050, 0.682±0.040), and the difference was statistically significant (P=0.049, 0.001). Compared with the control group, the relative expression level of cytochrome c protein in the cytoplasm of cells in the low dose group of CdCl(2) was not significantly increased (1.249±0.151), and the difference was not statistically significant (P=0.075). However, the relative expression level in the cytoplasm of cells in the high dose group of CdCl(2) was significantly increased (2.355±0.110), and the difference was statistically significant (P=0.000) ; The relative expression level of Cytochrome c in mitochondria of low and high dose CdCl(2) groups decreased significantly (0.681±0.043, 0.619±0.114), with a statistically significant difference (P=0.004, 0.001) ; Moreover, the level of cleaved Caspase-3 protein in cells gradually increased (5.486±0.544, 11.493±1.739), the difference was statistically significant (P=0.004, 0.000) . Conclusion: Cadmium induced cleaved Caspase-3 mediated apoptosis of GC-2 spd cells via promoting mitochrondrial fission and the release of Cytochrome c from the mitochrondria to the cytosol.
Male ; Mice ; Animals ; Mitochondrial Dynamics ; Caspase 3/metabolism* ; Cadmium/toxicity* ; Cytochromes c/metabolism* ; Fluorescent Dyes ; Apoptosis ; Apoptosis Regulatory Proteins/metabolism* ; Membrane Potential, Mitochondrial

As a classic fluorescent detect technique, fluorescence resonance energy transfer (FRET) has been widely used in biological researches. Researchers have developed a series of fluorescence detect probes which were based on FRET. Caspase family plays an important role in apoptosis pathway, especially Caspase-8 which located, at the initial of death receptor mediated apoptosis pathway, whose its activation can trigger subsequent precaspases' activation and lead to apoptosis. So it is of great significance to detect the activation of Caspase-8 in apoptosis assay. In this study, a fluorescent probe based on FRET has been designed which can detect the activity change of Caspase-8 in cells. To identify the effectiveness and specificity of the probe, we measure the Caspase-8 activity under the Caspase-8 specifically activated apoptosis inducer RGD-TRAIL with the flow cytometry FRET detection platform. The results show that the probe can respond to the activity change of Caspase-8 in apoptotic cells, and the change can be quantified rapidly by flow cytometry. The study provides a more efficient and convenient detection method of Caspase-8 activity in living cells.
Apoptosis ; Caspase 8 ; metabolism ; Flow Cytometry ; Fluorescence Resonance Energy Transfer ; Fluorescent Dyes ; Humans

OBJECTIVETo establish red-green dual-color fluorescence glioma model in nude mice and to explore its practical values.

METHODSCM-DiI-stained rat glioma C6 cells (C6-CM- DiI cells) expressing red fluorescence were inoculated into the brain of athymic nude mice expressing green fluorescence protein (NC-C57BL/6J-EGFP). Then the whole-body dual-color fluorescence imaging was detected dynamically. Finally whole brains of the tumor-bearing mice were removed and 5 µm thick serial frozen slices were made. Light microscopy, fluorescence microscopy and confocal laser scanning microscopy were performed to observe the transplanted tumor tissue structure and fluorescent cells.

RESULTSTumor mass with red fluorescence increased gradually under continuous in-vivo fluorescence imaging monitoring. Under the fluorescence microscope, cells with red, green and yellow fluorescence were observed in the frozen sections of transplanted tumor tissue and the mutual structural relationship among them could be defined. The tumor cells migration, implantation and cell fusion between transplanted tumor cells and host cells could be observed. It could be distinguished according to the fluorescence, that blood vessels of tumor-origin displayed red fluorescence, blood vessels of host-origin displayed green fluorescence and mosaic blood vessels appeared yellow fluorescence. It was depicted that host innate astrocytes and oligodendrocytes in the microenvironment at the tumor periphery could be activated and dedifferentiated into nestin-positive cells.

CONCLUSIONSIn contrast to traditional animal model, the dual-color fluorescence imaging of nude mouse models of glioma possesses enormous advantages in investigating tumor mass in-vivo fluorescence imaging, tumor cells migration and metastasis, tumor angiogenesis and reactive activation of host innate cells in the microenvironment at tumor periphery, thus, has highly practical application value.

Animals ; Astrocytes ; metabolism ; Brain Neoplasms ; blood supply ; metabolism ; pathology ; ultrastructure ; Carbocyanines ; metabolism ; Cell Fusion ; Cell Line, Tumor ; Cell Movement ; Disease Models, Animal ; Fluorescent Dyes ; metabolism ; Glioma ; blood supply ; metabolism ; pathology ; ultrastructure ; Green Fluorescent Proteins ; metabolism ; Luminescent Proteins ; metabolism ; Mice ; Mice, Inbred C57BL ; Mice, Nude ; Microscopy, Confocal ; Microscopy, Fluorescence ; Neoplasm Transplantation ; Neovascularization, Pathologic ; Nestin ; metabolism ; Oligodendroglia ; metabolism ; Rats

OBJECTIVETo investigate the effects of Pyrroloquinoline quinine (PQQ) on hydrogen peroxide-induced apoptosis of Schwann cells (SCs) and its mechanism.

METHODSSCs were isolated and cultured in vitro, and identified by S-100 immunofluorescence staining. The cultured SCs were divided into control group, hydrogen peroxide-treated group, hydrogen peroxide and PQQ treated groups. The intracellular superoxide dismutase (SOD) and malondialdehyde (MDA) content was detected; the apoptotic rate of SCs induced by hydrogen peroxide was determined by flow cytometry assay. The Hoechst33342 staining was used to detect the nuclear fragmentation and apoptotic nuclear condensation of SCs; the Rhodamine123 staining was used to detect the changes of mitochondrial membrane potential in SCs, the Western blot analysis was used to detect the expression of Bcl-2 in hydrogen peroxide induced SCs.

RESULTSThe SOD activity was significantly decreased and MDA level was increased in H2O2 induced SCs (P < 0.05), after addition of PQQ, the SOD content increased and MDA content decreased (P < 0.05). Flow cytometry results showed that the early apoptotic rate was 58.8% in H2O2 induced SCs, which has significant difference compared with the control group (P < 0.05), after addition of 10, 50, 100 nmol/L PQQ, the apoptotic rates were reduced to 33.7%, 18.7%, 3.9% respectively, showing significantly different with injured group (P < 0.05). Hoechst 33342 staining showed that H2O2 induced SCs had typical morphological characteristics, such as uptake of nuclear chromatin, nuclear shrinkage, nuclear fragmentation phenomenon. The proportion of apoptotic cells after PQQ treatment reduced. Rhodamine staining results showed that the H2O2 induced mitochondrial membrane potential reduction in SCs, which was reversed by addition of PQQ. Western blot analysis showed that the expression of Bcl-2 was decreased in H2O2 induced SCs, while it increased significantly after addition of PQQ (P < 0.05).

CONCLUSIONPQQ has a protective effect on oxidative stress-induced apoptosis of SCs.

Apoptosis ; drug effects ; Benzimidazoles ; Cell Nucleus ; drug effects ; DNA Fragmentation ; Fluorescent Dyes ; Humans ; Hydrogen Peroxide ; pharmacology ; Malondialdehyde ; metabolism ; Oxidants ; pharmacology ; Oxidative Stress ; Pyrroles ; pharmacology ; Quinine ; pharmacology ; Quinolines ; pharmacology ; Schwann Cells ; cytology ; drug effects ; Superoxide Dismutase ; metabolism

The objective of the study was to analyse Streptococcus mutans biofilms grown under different dietary conditions by using multifaceted methodological approaches to gain deeper insight into the cariogenic impact of carbohydrates. S. mutans biofilms were generated during a period of 24 h in the following media: Schaedler broth as a control medium containing endogenous glucose, Schaedler broth with an additional 5% sucrose, and Schaedler broth supplemented with 1% xylitol. The confocal laser scanning microscopy (CLSM)-based analyses of the microbial vitality, respiratory activity (5-cyano-2,3-ditolyl tetrazolium chloride, CTC) and production of extracellular polysaccharides (EPS) were performed separately in the inner, middle and outer biofilm layers. In addition to the microbiological sample testing, the glucose/sucrose consumption of the biofilm bacteria was quantified, and the expression of glucosyltransferases and other biofilm-associated genes was investigated. Xylitol exposure did not inhibit the viability of S. mutans biofilms, as monitored by the following experimental parameters: culture growth, vitality, CTC activity and EPS production. However, xylitol exposure caused a difference in gene expression compared to the control. GtfC was upregulated only in the presence of xylitol. Under xylitol exposure, gtfB was upregulated by a factor of 6, while under sucrose exposure, it was upregulated by a factor of three. Compared with glucose and xylitol, sucrose increased cell vitality in all biofilm layers. In all nutrient media, the intrinsic glucose was almost completely consumed by the cells of the S. mutans biofilm within 24 h. After 24 h of biofilm formation, the multiparametric measurements showed that xylitol in the presence of glucose caused predominantly genotypic differences but did not induce metabolic differences compared to the control. Thus, the availability of dietary carbohydrates in either a pure or combined form seems to affect the cariogenic potential of S. mutans biofilms.
Bacterial Load ; drug effects ; Bacteriological Techniques ; Biofilms ; drug effects ; Cariogenic Agents ; metabolism ; pharmacology ; Culture Media ; Dental Enamel ; microbiology ; Fluorescent Dyes ; Gene Expression Regulation, Bacterial ; drug effects ; Gene Expression Regulation, Enzymologic ; drug effects ; Genotype ; Glucose ; metabolism ; Glucosyltransferases ; metabolism ; Humans ; Microbial Viability ; drug effects ; Microscopy, Confocal ; Polysaccharides, Bacterial ; biosynthesis ; Streptococcus mutans ; drug effects ; enzymology ; metabolism ; Sucrose ; metabolism ; pharmacology ; Sweetening Agents ; metabolism ; pharmacology ; Tetrazolium Salts ; Time Factors ; Up-Regulation ; Xylitol ; metabolism ; pharmacology

The effects of mouse oocyte vitrification on mitochondrial membrane potential and distribution were explored in this study. The collected mouse oocytes were randomly divided into vitrification and control groups. Ethylene glycol (EG) and dimethylsulphoxide (DMSO) were used as cryoprotectants in the vitrification group. The mitochondrial function and distribution in the oocytes were examined by using the fluorescent probes, JC-1 and Mito Tracker green. The results showed that the ratio of red to green fluorescence in mouse oocytes was significantly decreased after thawing in the vitrification group as compared with the control group (1.28 vs. 1.70, P<0.05). The percentage of polarized distribution of the mitochondria in oocytes was conspicuously reduced in the vitrification group when compared with the control group (31% vs. 63%, P<0.05). It was suggested that vitrification significantly affects the mitochondrial function and distribution in oocytes and reduces the potential of oocyte fertilization and embryo development.
Animals ; Cryopreservation ; methods ; Cryoprotective Agents ; pharmacology ; Dimethyl Sulfoxide ; pharmacology ; Ethylene Glycol ; pharmacology ; Female ; Fluorescent Dyes ; metabolism ; Membrane Potential, Mitochondrial ; drug effects ; physiology ; Mice ; Microscopy, Fluorescence ; Mitochondria ; drug effects ; metabolism ; Oocytes ; drug effects ; physiology ; Temperature ; Vitrification

Animals ; Cattle ; Cell Line ; Electrophoresis, Polyacrylamide Gel ; Fluorescent Dyes ; chemistry ; Malondialdehyde ; chemistry ; Mice ; Microscopy, Confocal ; Serum Albumin, Bovine ; analysis ; chemistry ; metabolism ; Ultraviolet Rays

Alzheimer Disease ; metabolism ; pathology ; Amyloid beta-Peptides ; metabolism ; Animals ; Brain ; metabolism ; pathology ; Cerebral Amyloid Angiopathy ; metabolism ; pathology ; Fluorescent Dyes ; chemistry ; Humans ; Mice ; Peptide Fragments ; metabolism ; Staining and Labeling ; Thiazoles ; chemistry

Cancer stem cell (CSC) research has increased exponentially to gain further insight into the mechanisms underlying both carcinogenesis and chemotherapy resistance. The present study was performed to explore the potential value of a side population (SP) assay for identifying and characterizing putative CSCs among canine lymphoma cells. Canine lymphoma cells from cell lines and clinical samples were subjected to the SP assay consisting of Hoechst 33342 staining and subsequent flow cytometric analysis. The SP assay revealed various amounts of a SP fraction among the canine lymphoma cells. The percentages of SP were not affected by inhibitors of membrane transporters, verapamil hydrochloride, or fumitremorgin C. Most of the canine lymphoma cells expressed high levels of Bmi-1 and membrane transporter proteins such as ABCG2 and phosphorylated (p)-glycoprotein. This investigation lays the groundwork for further studies of the biological behaviors and molecular characteristics of CSCs in cases of canine lymphoma.
Animals ; Benzimidazoles/*metabolism ; Cell Line, Tumor ; Dog Diseases/*diagnosis/drug therapy/pathology ; Dogs ; Flow Cytometry/*methods/veterinary ; Fluorescent Dyes/*metabolism ; Gene Expression Regulation, Developmental ; Lymphoma/diagnosis/drug therapy/pathology/*veterinary ; Neoplastic Stem Cells/drug effects/*metabolism/pathology ; Side-Population Cells/drug effects/*metabolism/pathology