Autophagy is a process of bulk degradation of proteins and organelles in cytoplasm.Autophagy has many normal physiological functions in cellular catabolism; therefore is essential for cell homeostasis. In some circumstances autophagy can induces cell death, namely autophagic cell death. Recent studies have suggested that autophagy plays an important role in both normal tissue development and a variety of diseases, including cancer. Therefore, the strategy targeting autophagy pathway may represent a new way of cancer treatment.
Apoptosis ; physiology ; Autophagy ; physiology ; Cell Death ; physiology ; Hematologic Neoplasms ; pathology ; physiopathology ; Signal Transduction

OBJECTIVETo investigate the regulation of different hypoxia on cell survival and autophagy.

METHODSPC12 cells were treated with different hypoxia. The cell survival was measured by MTT assay, expressions of LC3 and p62 were marked for autophagy detected by Western Blot, and the level of reactive oxygen species (ROS) was analyzed by flow cytometry.

RESULTSThe cell viability was different under different hypoxia: moderate hypoxia promoted cell viability, and severe hypoxia caused a decrease in cell viability; autophagy marker molecules, p62 and LC3-II expressions were different: moderate hypoxia increased p62 and LC3-II expressions, in contrast, severe hypoxia led to the decrease of p62 and LC3-II expressions; compared to normoxia, moderate hypoxia did not change the levels of ROS, while severe hypoxia increased the levels; 3-MA, the inhibitor of autophagy, elevated the levels of ROS in the three oxygen concentrations, additionally, the increased amplitudes in the moderate and severe hypoxia groups were higher than that in the normoxia group.

CONCLUSIONModerate hypoxia promotes cell survival, severe hypoxia causes the cell death, and the autophagy activity may mediate the effects of different hypoxia.

Animals ; Autophagy ; physiology ; Cell Death ; Cell Hypoxia ; Cell Survival ; PC12 Cells ; Rats ; Reactive Oxygen Species ; metabolism

Erythrocytes lack nuclei and mitochondria, critical elements in the machinery of nucleated cell apoptosis. However, most recently, it became obvious that erythrocytes may undergo programmed aging, as well as suicidal death. The term eryptosis has been coined to describe the suicidal erythrocyte death. Eryptosis is triggered mainly by increased cytosolic Ca(2+) activity, in turn, Ca(2+) activates Ca(2+)-sensitive K(+) channels, scramblase, calpain and other proteases, respectively. A series of molecular events of erythrocyte programmed death induced. The cascade reaction of related molecules and finally lead to cell clearance. There is evidence suggesting that erythrocytes aging and death process are regulated tightly and there are many molecular participants and signaling pathways involved in aging and death process of erythrocytes. Erythrocytes have already been used as a model for aging study, and the knowledge about mechanisms involved in eryptosis may provide an important clue to understand the mechanisms involved in suicidal death of nucleated cells. In this review the factors influencing programmed death of erythrocytes, the role of Ca(2+) and ceramide in programmed death of erythrocytes, the role of blebbing in process of erythrocyte aging, the antigens of erythrocyte aging and so on are summarized.
Calcium ; physiology ; Cell Death ; Cellular Senescence ; Ceramides ; physiology ; Erythrocytes ; cytology ; Humans

Transient receptor potential (TRP) channel is a superfamily of cation channels located on the cell membrane. TRP channels are classified into seven subfamilies based on the amino acid sequence homology,and transient receptor potential melastatin 2(TRPM2) is the second member of the TRPM subfamily. More evidences have revealed the important roles of TRPM2 in physiological and pathological events such as release of insulin from pancreatic Β-cells,inflammatory cytokines production from cells,and oxidative stress-induced cell death. As a cellular sensor for oxidative stress channel,TRPM2 is activated by a variety of factors. TRPM2 is a potential therapeutic target for oxidative stress-related diseases.
Cell Death ; Cytokines ; Humans ; Insulin ; Oxidative Stress ; TRPM Cation Channels ; physiology

OBJECTIVEIn this study, human bronchial epithelial cells were inoculated with positive sputum specimens of HBoV. After four days' infection, cytopathic effects (CPE) were observed by inverted microscopy. These viruses all cause typical cell damages such as rounded and shrivelled, fusion and fallout. These damages got quick following increased future degenerations. The other assay result of CPE within the infected cells were observed by inverted microscopy, have typical "owl's eye" plaque and above 90 percent hemadsorption within the infected cells by erythrocytes for hemadsorption technique. The typical fluorescence lump of nucleus within the infected cells was found by indirect immunofluorescence technique.

CONCLUSIONIsolation and identification of HBoV could be done in the human bronchial epithelial cell, and we found some characterizing CPE in the human bronchial epithelial cell after HBoV infection. The above studies pave a way for studying pathogenicity of human bocavirus.

Bocavirus ; physiology ; Bronchi ; cytology ; Cell Death ; physiology ; Cell Survival ; physiology ; Cells, Cultured ; Epithelial Cells ; cytology ; virology ; Fluorescent Antibody Technique, Indirect ; Host-Pathogen Interactions ; Humans ; Microscopy, Fluorescence

Spinal cord injury (SCI) is frequently companied by necrosis and apoptosis of oligodendrocytes (OLs), which contributes to demyelination of myelinated nerve fibers and their electrophysiological defects. This pathological demyelination often results in sensory or motor deficits. Here, we first focus on the microenvironment changes after SCI that cause OLs' death, then discuss the major mechanism of endogenous oligodendrocytogenesis and axonal remyelination, and finally summarize current therapies targeting OLs protection and replacement.
Animals ; Apoptosis ; physiology ; Cell Death ; physiology ; Humans ; Necrosis ; pathology ; Nerve Fibers, Myelinated ; pathology ; Nerve Regeneration ; physiology ; Oligodendroglia ; pathology ; Spinal Cord ; physiopathology ; Spinal Cord Injuries ; pathology ; physiopathology ; therapy

The manner of cell death is a hotspot of medical researchers. Apoptosis and necrosis were considered as two manners of cell death in the past. But recently a new manner of cell death--oncosis is gradually accepted by the pathologists. Oncosis is different from apoptosis in morphologic, mechanism and the role in cardiovascular diseases. In this paper, the progression of the research about manner of the cardiomyocyte death and its significance in forensic medicine in recent years was reviewed.
Animals ; Apoptosis/physiology* ; Cardiomyopathies/pathology* ; Cell Death/physiology* ; DNA Damage/physiology* ; Forensic Medicine ; Humans ; Myocardial Ischemia/pathology* ; Myocytes, Cardiac/cytology* ; Necrosis ; Signal Transduction

BACKGROUNDSam68 plays an important role as a multiple functional RNA binding nuclear protein in cell cycle progress, RNA usage, signal transduction, and tyrosine phosphorylation by Src during mitosis. However, its precise impact on these essential cellular functions remains unclear. The purpose of this study is to further elucidate Sam68 functions in RNA metabolism, signal transduction regulation of cell growth and cell proliferation in DT40 cell line.

METHODSBy using gene targeting method, we isolated a mutation form of Sam68 in DT40 cells and described its effect on cell growth process and signal transduction. Southern, Northern, and Western blot, phosphorylation and flow-cytometric analyses were performed to investigate the Sam68 functions.

RESULTSA slower growth rate (2.1 hours growth elongation) and longer S phase (1.7 hours elongation) was observed in the Sam68 mutant cells. Serum depletion resulted in increased amounts of dead cells, and expansion of S phase in mutant cells. Upon B cell cross-linking, the maximal level of tyrosine phosphorylation on BLNK was observed to be significantly lower in mutant cells.

CONCLUSIONSThe proline rich domain of Sam68 is involved in cell growth control by modulating the function of mRNAs in S phase or earlier and the functions as an adaptor molecule in B cell signal transduction pathways.

Adaptor Proteins, Signal Transducing ; genetics ; metabolism ; physiology ; Animals ; B-Lymphocytes ; cytology ; immunology ; physiology ; Binding Sites ; genetics ; Blotting, Western ; Cell Cycle ; physiology ; Cell Death ; physiology ; Cell Growth Processes ; drug effects ; physiology ; Cell Line, Tumor ; Culture Media, Serum-Free ; pharmacology ; Mutation ; genetics ; Phosphorylation ; Proline ; genetics ; RNA-Binding Proteins ; genetics ; metabolism ; physiology ; Receptors, Antigen, B-Cell ; immunology ; physiology ; Signal Transduction ; drug effects ; physiology ; Tyrosine ; metabolism

Naegleria fowleri, a ubiquitous free-living ameba, causes fatal primary amebic meningoencephalitis in humans. N. fowleri trophozoites are known to induce cytopathic changes upon contact with microglial cells, including necrotic and apoptotic cell death and pro-inflammatory cytokine release. In this study, we treated rat microglial cells with amebic lysate to probe contact-independent mechanisms for cytotoxicity, determining through a combination of light microscopy and scanning and transmission electron microscopy whether N. fowleri lysate could effect on both necrosis and apoptosis on microglia in a time- as well as dose-dependent fashion. A 51Cr release assay demonstrated pronounced lysate induction of cytotoxicity (71.5%) toward microglial cells by 24 hr after its addition to cultures. In an assay of pro-inflammatory cytokine release, microglial cells treated with N. fowleri lysate produced TNF-alpha, IL-6, and IL-1beta, though generation of the former 2 cytokines was reduced with time, and that of the last increased throughout the experimental period. In summary, N. fowleri lysate exerted strong cytopathic effects on microglial cells, and elicited pro-inflammatory cytokine release as a primary immune response.
Animals ; *Cell Death ; Chromium Radioisotopes/metabolism ; Cytokines/*secretion ; Humans ; Microglia/cytology/immunology/*physiology ; Microscopy ; Naegleria fowleri/*pathogenicity ; Rats ; Staining and Labeling

Acute and chronic neurodegenerative diseases are illnesses associated with high morbidity and mortality, and few or no effective options are available for their treatments. Many neurodegenerative diseases are included in them, for example, stroke, brain trauma, spinal cord injury, amyotrophic lateral sclerosis (ALS), Huntington's disease, Alzheimer's disease, and Parkinson's disease. Given that central nervous system tissue has very limited, if any, regenerative capacity, it is of utmost importance to limit the damage caused by neuronal death. During the past decade, considerable progress has been made in understanding the process of cell death. In this article, we review the causes and mechanisms of neuronal-cell death, especially as it pertains to the caspases family of proteases associated with cell death. The results may be helpful to the experimental research and clinical application of neurodegenerative diseases.
Animals ; Apoptosis ; physiology ; Caspases ; metabolism ; Cell Death ; Humans ; Neurodegenerative Diseases ; enzymology ; pathology ; Neurons ; pathology ; Peptide Hydrolases ; metabolism