Trichomonas vaginalis is a flagellated protozoan parasite that causes vaginitis and cervicitis in women and asymptomatic urethritis and prostatitis in men. Mast cells have been reported to be predominant in the vaginal smears and vaginal walls of patients infected with T. vaginalis. Mitogen activated protein kinase (MAPK) activated by various stimuli also regulate the transcriptional activity of various cytokine genes in the mast cells. Because of their essential role in intracellular signaling network, also appropriate targets for pharmacological treatment of inflammatory disorders.Cultivation of T.vaginalis and HMC-1 line, preparation of TvSP, to check intracellular ROS level and degranulation by FACS, to determine phosphorylation of MAPK and p47phox by immunobloting.In this study, we investigated whether MAPK were involved ROS generation and exocytotic degranulation in HMC-1 induced by T. vaginalis-derived secretory products (TvSP). We first examined that TvSP could induce activation of MAPK and NADPH oxidase in HMC-1 cells. Stimulation with TvSP induced phosphorylation of MAPK and p47phox in HMC-1 cells. Phosphorylation of p47phox is main source of ROS generation. Next, to determine involvement activation of MAPK in ROS generation and degranulation in HMC-1 cells induced by TvSP. ROS generation is required for exocytotic degranulation of mast cells induced by TvSP. Stimulation with TvSP induced phosphorylation of p47phox, ROSgeneration, and surface up-regulation of CD63 in human mast cells. CD63 is a marker for exocytosis. Pretreatment with MAPK inhibitors strongly inhibited TvSP-induced ROS generation and exocytotic degranulation.Our results suggest that TvSP could induce intracellular ROS generation and exocytotic degranulation in HMC-1 via MAPK signaling pathway.

We found a mistake in our recently published article.

Entamoeba histolytica is a tissue-invasive protozoan parasite causing dysentery in humans. During infection of colonic tissues, amoebic trophozoites are able to kill host cells via apoptosis or necrosis, both of which trigger IL-8-mediated acute inflammatory responses. However, the signaling pathways involved in host cell death induced by E. histolytica have not yet been fully defined. In this study, we examined whether calpain plays a role in the cleavage of pro-survival transcription factors during cell death of colonic epithelial cells, induced by live E. histolytica trophozoites. Incubation with amoebic trophozoites induced activation of m-calpain in a time- and dose-dependent manner. Moreover, incubation with amoebae resulted in marked degradation of STAT proteins (STAT3 and STAT5) and NF-kappaB (p65) in Caco-2 cells. However, IkappaB, an inhibitor of NF-kappaB, was not cleaved in Caco-2 cells following adherence of E. histolytica. Entamoeba-induced cleavage of STAT proteins and NF-kappaB was partially inhibited by pretreatment of cells with a cell-permeable calpain inhibitor, calpeptin. In contrast, E. histolytica did not induce cleavage of caspase-3 in Caco-2 cells. Furthermore, pretreatment of Caco-2 cells with a calpain inhibitor, calpeptin (but not the pan-caspase inhibitor, z-VAD-fmk) or m-calpain siRNA partially reduced Entamoeba-induced DNA fragmentation in Caco-2 cells. These results suggest that calpain plays an important role in E. histolytica-induced degradation of NF-kappaB and STATs in colonic epithelial cells, which ultimately accelerates cell death.
Caco-2 Cells ; Calcium-Binding Proteins ; Calpain/genetics/metabolism ; Caspase 3/genetics/metabolism ; Caspases ; *Cell Death ; Colon/cytology ; Entamoeba histolytica/*physiology ; Epithelial Cells/cytology/parasitology ; Humans ; I-kappa B Proteins/metabolism ; Intestinal Mucosa/cytology ; NF-kappa B/genetics/*metabolism ; RNA Interference ; RNA, Small Interfering ; STAT3 Transcription Factor/genetics/*metabolism ; STAT5 Transcription Factor/genetics/*metabolism ; Signal Transduction

The enteric protozoan parasite Entamoeba histolytica is the causative agent of human amebiasis. During infection, adherence of E. histolytica through Gal/GalNAc lectin on the surface of the amoeba can induce caspase-3-dependent or -independent host cell death. Phosphorylinositol 3-kinase (PI3K) and protein kinase C (PKC) in E. histolytica play an important function in the adhesion, killing, or phagocytosis of target cells. In this study, we examined the role of amoebic PI3K and PKC in amoeba-induced apoptotic cell death in Jurkat T cells. When Jurkat T cells were incubated with E. histolytica trophozoites, phosphatidylserine (PS) externalization and DNA fragmentation in Jurkat cells were markedly increased compared to those of cells incubated with medium alone. However, when amoebae were pretreated with a PI3K inhibitor, wortmannin before being incubated with E. histolytica, E. histolytica-induced PS externalization and DNA fragmentation in Jurkat cells were significantly reduced compared to results for amoebae pretreated with DMSO. In addition, pretreatment of amoebae with a PKC inhibitor, staurosporine strongly inhibited Jurkat T cell death. However, E. histolytica-induced cleavage of caspase-3, -6, and -7 were not inhibited by pretreatment of amoebae with wortmannin or staurosporin. In addition, we found that amoebic PI3K and PKC have an important role on amoeba adhesion to host compartment. These results suggest that amebic PI3K and PKC activation may play an important role in caspase-independent cell death in Entamoeba-induced apoptosis.
*Apoptosis ; Caspases/metabolism ; Entamoeba histolytica/*enzymology/*growth & development ; Humans ; Hydrolysis ; Jurkat Cells ; Phosphatidylinositol 3-Kinases/*metabolism ; Protein Kinase C/*metabolism ; T-Lymphocytes/*parasitology/*physiology

Cancer causes a significant deterioration in health and premature death and is a national socioeconomic burden. This study aimed to measure the burden of cancer using the disability-adjusted life year (DALY) metric based on the newly adopted methodology from the Global Burden of Disease Study in 2010. This study was conducted based on data from the Korean National Cancer Registry. The DALYs were calculated using a prevalence-based method instead of the incidence-based method used by previous studies. The total burden of cancer in 2012 was 3,470.79 DALYs per 100,000 persons. Lung cancer was the most prevalent cancer burden, followed by liver, stomach, colorectal, and breast cancer. The DALYs for lung, liver, stomach, colon and rectum, and pancreatic cancer were high in men, whereas the DALYs for breast, lung, stomach, colorectal, and liver cancer were high in women. Health loss from leukemia and cancer of the brain and nervous system was prevalent for those younger than age 20; from stomach, breast, and liver for those aged 30–50; and from lung, colon and rectum, and pancreas for a large proportion of individuals over the age of 60. The most important differences were that the DALYs were calculated by prevalence and that other components of the DALYs were measured by a population-based perspective. Thus, prevalence-based DALYs could provide more suitable data for decision making in the healthcare field.
Brain Neoplasms ; Breast ; Breast Neoplasms ; Colon ; Decision Making ; Delivery of Health Care ; Female ; Humans ; Korea* ; Leukemia ; Liver ; Liver Neoplasms ; Lung ; Lung Neoplasms ; Male ; Methods ; Mortality, Premature ; Nervous System ; Pancreas ; Pancreatic Neoplasms ; Prevalence ; Rectum ; Stomach

Trichomonas vaginalis is a flagellated protozoan parasite that causes vaginitis and cervicitis in women and asymptomatic urethritis and prostatitis in men. Mast cells have been reported to be predominant in vaginal smears and vaginal walls of patients infected with T. vaginalis. Mitogen-activated protein kinase (MAPK), activated by various stimuli, have been shown to regulate the transcriptional activity of various cytokine genes in mast cells. In this study, we investigated whether MAPK is involved in ROS generation and exocytotic degranulation in HMC-1 cells induced by T. vaginalis-derived secretory products (TvSP). We found that TvSP induces the activation of MAPK and NADPH oxidase in HMC-1 cells. Stimulation with TvSP induced phosphorylation of MAPK and p47phox in HMC-1 cells. Stimulation with TvSP also induced up-regulation of CD63, a marker for exocytosis, along the surfaces of human mast cells. Pretreatment with MAPK inhibitors strongly inhibited TvSP-induced ROS generation and exocytotic degranulation. Finally, our results suggest that TvSP induces intracellular ROS generation and exocytotic degranulation in HMC-1 via MAPK signaling.
Cell Degranulation ; Cell Line ; *Exocytosis ; Humans ; Mast Cells/*drug effects/*metabolism ; Mitogen-Activated Protein Kinases/*metabolism ; Reactive Oxygen Species/*metabolism ; Trichomonas vaginalis/*metabolism ; Virulence Factors/*metabolism

Entamoeba histolytica, which causes amoebic colitis and occasionally liver abscess in humans, is able to induce host cell death. However, signaling mechanisms of colon cell death induced by E. histolytica are not fully elucidated. In this study, we investigated the signaling role of NOX in cell death of HT29 colonic epithelial cells induced by E. histolytica. Incubation of HT29 cells with amoebic trophozoites resulted in DNA fragmentation that is a hallmark of apoptotic cell death. In addition, E. histolytica generate intracellular reactive oxygen species (ROS) in a contact-dependent manner. Inhibition of intracellular ROS level with treatment with DPI, an inhibitor of NADPH oxidases (NOXs), decreased Entamoeba-induced ROS generation and cell death in HT29 cells. However, pan-caspase inhibitor did not affect E. histolytica-induced HT29 cell death. In HT29 cells, catalytic subunit NOX1 and regulatory subunit Rac1 for NOX1 activation were highly expressed. We next investigated whether NADPH oxidase 1 (NOX1)-derived ROS is closely associated with HT29 cell death induced by E. histolytica. Suppression of Rac1 by siRNA significantly inhibited Entamoeba-induced cell death. Moreover, knockdown of NOX1 by siRNA, effectively inhibited E. histolytica-triggered DNA fragmentation in HT29 cells. These results suggest that NOX1-derived ROS is required for apoptotic cell death in HT29 colon epithelial cells induced by E. histolytica.
*Cell Death ; Cell Line ; Entamoeba histolytica/*pathogenicity ; Epithelial Cells/metabolism/*parasitology/*physiology ; *Host-Pathogen Interactions ; Humans ; NADPH Oxidase/*metabolism ; Reactive Oxygen Species/metabolism/*toxicity ; Signal Transduction