scholarly journals Investigating neutrophil cell death in TB pathogenesis

2021 ◽  
Vol 5 ◽  
pp. 175
Author(s):  
Kimone L Fisher ◽  
Kerishka Rajkumar-Bhugeloo ◽  
Denelle Moodley ◽  
Thabo Mpotje ◽  
Duran Ramsuran ◽  
...  
Keyword(s):  
Cell Death ◽  
Disease Progression ◽  
Latently Infected ◽  
Role Players ◽  
A Cell ◽  
Vitro Model ◽  
Temporal Events ◽  
Neutrophil Cell

Background: Neutrophils are one of the major early role players in antimycobacterial immunity. Upon infection, neutrophils can undergo NETosis, a cell death characterized by release of neutrophil extracellular traps (NETs). The role of NETosis in TB progression remains poorly characterized. We aim to characterize mechanisms underlying NETosis during TB pathogenesis by identifying genes that drive the cell death, and to determine their potential as markers of disease progression in high-risk individuals. Finally, we intend to evaluate neutrophil associated genes as targets for host directed therapy to reduce pathological damage caused by NETosis. Methods: Quantitative PCR will be used to quantify expression of specific genes identified in the blood of individuals with active lung disease (n=30), compared to those from healthy (n=30) and latently infected individuals (LTBI) (n=30). In addition, temporal events associated with NETosis will be measured using live microscopy in a neutrophil in vitro model of Mycobacterium tuberculosis (Mtb) infection. Candidate genes found to be associated with NETosis will be targeted with pharmaceutical inhibitors. Conclusion: Genes associated with neutrophil mediated cell death may serve as potential biomarkers of pathological damage and disease progression, as well as targets for host-directed therapy.

scholarly journals OXPHOS Promotes Apoptotic Resistance and Persistence in TH17 cells

2021 ◽  
Author(s):  
Hanna S. Hong ◽  
Nneka E. Mbah ◽  
Mengrou Shan ◽  
Kristen Loesel ◽  
Lin Lin ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
Cell Fate ◽  
Apoptotic Cell ◽  
Metabolic Phenotype ◽  
Tumor Studies ◽  
A Cell

AbstractApoptotic cell death is a cell-intrinsic, immune tolerance mechanism that regulates the magnitude and resolution of T cell-mediated responses. Evasion of apoptosis is critical for the generation of memory T cells, as well as autoimmune T cells, and knowledge of the mechanisms that enable resistance to apoptosis will provide insight into ways to modulate their activity during protective and pathogenic responses. IL-17-producing CD4 T cells (TH17s) are long-lived, memory cells. These features enable their role in host defense, chronic inflammatory disorders, and anti-tumor immunity. A growing number of reports now indicate that TH17s in vivo require mitochondrial oxidative phosphorylation (OXPHOS), a metabolic phenotype that is poorly induced in vitro. To elucidate the role of OXPHOS in TH17 processes, we developed a system to polarize TH17s that metabolically resembled their in vivo counterparts. We discovered that directing TH17s to use OXPHOS promotes mitochondrial fitness, glutamine anaplerosis, and an anti-apoptotic phenotype marked by high BCL-XL and low BIM. Through competitive co-transfer experiments and tumor studies, we further revealed how OXPHOS protects TH17s from cell death while enhancing their persistence in the periphery and tumor microenvironment. Together, our work demonstrates a non-classical role of metabolism in regulating TH17 cell fate and highlights the potential for therapies that target OXPHOS in TH17-driven diseases.

scholarly journals Lymphocytes Protect Cortical Neurons Against Excitotoxicity Mediated by Kainic Acid, an in vitro Model for Neurodegeneration

2015 ◽  
Vol 11 (2) ◽  
pp. 132-138 ◽  
Author(s):  
R Shrestha ◽  
O Millington ◽  
J Brewer ◽  
T Bushell
Keyword(s):  
T Cells ◽  
Cell Death ◽  
Kainic Acid ◽  
Cortical Neurons ◽  
In Vitro Model ◽  
Harmful Effect ◽  
Activated T Cells ◽  
Vitro Model

Background Neurodegenerative disease is a progressive loss of neurons from the central nervous system (CNS). Various conditions have been implicated for such conditions including ageing, inflammation, stress and genetic predisposition. Recently, studies have linked neurodegeneration with inflammation. Some studies have suggested the harmful effect of immune response while others have argued its neuroprotective role in neurodegeneration of the CNS. However, the precise role of inflammation and immune cells in such condition is still not clear. Objective To investigate the role of lymphocytes in neurodegeneration of the CNS and determine the underlying mechanism. Method We have used 4-7 days old mouse pups (C57Bl6) to prepare organotypic slice cultures which were cultured for 13-15 days prior to experiment. To induced cell death kainic acid was used and considered as an in vitro model for neurodegeneration. Lymphocytes were obtained from peripheral lymph nodes of 5-10 weeks old adult mouse which were used in the current study. Propidium iodide was used as a fluorescent dye to determine cell death in brain slice cultures. Result Lymphocytes do not induce cell death in slice cultures in the absence of any toxic insult whereas, after applying toxic insult to the slice cultures using kainic acid, lymphocytes show neuroprotection against such insult. Similarly, purified non-activated and purified activated T cells along with T cells depleted lymphocyte preparation also exhibit neuroprotection against kainic acid-induced cell death. We further, have demonstrated that the observed neuroprotection is contact-independent and soluble mediators released from lymphocytes are responsible for the observed neuroprotection. Moreover, our study has revealed that soluble mediators exhibiting neuroprotection act via astrocytes. Conclusion Lymphocyte preparations are neuroprotective and the observed neuroprotection is contact-independent. Soluble mediators released from lymphocytes are responsible for the observed neuroprotection. DOI: http://dx.doi.org/10.3126/kumj.v11i2.12488 Kathmandu University Medical Journal Vol.11(2) 2013: 132-138

scholarly journals The role of nitric oxide synthesis induction and inhibition in regulation of blood neutrophil cell death during oxidative disbalance

2010 ◽  
Vol 56 (5) ◽  
pp. 587-595 ◽  
Author(s):  
N.V. Ryazantseva ◽  
T.V. Zhavoronok ◽  
E.A. Stepovaya ◽  
Yu.V. Starikov ◽  
V.A. Bychkov
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Cell Death ◽  
Cyclic Nucleotides ◽  
Acute Inflammation ◽  
Nitric Oxide Synthesis ◽  
Blood Neutrophil ◽  
Neutrophil Cell

Modeling oxidative stress in vitro with 5мМ H2O2 has demonstrated a protective role of nitric oxide on realization of constitutional blood neutrophil cell death. The NO-synthase inductor L-arginine and the inhibitor of nitric oxide synthesis, L-NAME, influenced on the amount of annexin-positive cells, the content of Bax protein, reactive oxygen species, cyclic nucleotides, and calcium homeostasis in neutrophils under conditions realizing programmed death during oxidative stress in vitro and under acute inflammation. During oxidative stress L-arginine normalized the increased intracellular Ca2+ level and the cАМP/cGМP ratio due to increase of cGМP level, stabilized metabolism and prolonged neutrophil life. During acute inflammation NO induction was insufficient for limitation of Ca2+ release into cytosol and for onset of the apoptotic effect; blockade of NO synthesis deteriorated this situation by activating neutrophil apoptosis due to the sharp increase in Ca2+ content and reduction of cyclic nucleotides in cytosol. The protective effect of NO on neutrophil cell death during oxidative dysbalance is not associated with regulation of apoptotic protein Bax.

Preincubation with Sn-complexes causes intensive intracellular retention of 99mTc in thyroid cells in vitro

2012 ◽  
Vol 51 (05) ◽  
pp. 179-185 ◽  
Author(s):  
M. Wendisch ◽  
D. Aurich ◽  
R. Runge ◽  
R. Freudenberg ◽  
J. Kotzerke ◽  
...  
Keyword(s):  
Cell Model ◽  
Low Energy ◽  
Thyroid Cells ◽  
Low Energy Electrons ◽  
A Cell ◽  
Vitro Model ◽  
Uptake Studies ◽  
Radiobiological Effects ◽  
Radioactivity Retention

SummaryTechnetium radiopharmaceuticals are well established in nuclear medicine. Besides its well-known gamma radiation, 99mTc emits an average of five Auger and internal conversion electrons per decay. The biological toxicity of these low-energy, high-LET (linear energy transfer) emissions is a controversial subject. One aim of this study was to estimate in a cell model how much 99mTc can be present in exposed cells and which radiobiological effects could be estimated in 99mTc-overloaded cells. Methods: Sodium iodine symporter (NIS)- positive thyroid cells were used. 99mTc-uptake studies were performed after preincubation with a non-radioactive (cold) stannous pyro - phosphate kit solution or as a standard 99mTc pyrophosphate kit preparation or with pure pertechnetate solution. Survival curves were analyzed from colony-forming assays. Results: Preincubation with stannous complexes causes irreversible intracellular radioactivity retention of 99mTc and is followed by further pertechnetate influx to an unexpectedly high 99mTc level. The uptake of 99mTc pertechnetate in NIS-positive cells can be modified using stannous pyrophosphate from 3–5% to >80%. The maximum possible cellular uptake of 99mTc was 90 Bq/cell. Compared with nearly pure extracellular irradiation from routine 99mTc complexes, cell survival was reduced by 3–4 orders of magnitude after preincubation with stannous pyrophosphate. Conclusions: Intra cellular 99mTc retention is related to reduced survival, which is most likely mediated by the emission of low-energy electrons. Our findings show that the described experiments constitute a simple and useful in vitro model for radiobiological investigations in a cell model.

scholarly journals YAP inhibits autophagy and promotes progression of colorectal cancer via upregulating Bcl-2 expression

2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Lan Jin ◽  
Yunhe Chen ◽  
Dan Cheng ◽  
Zhikai He ◽  
Xinyi Shi ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cell Death ◽  
Transcriptional Coactivator ◽  
Inhibitory Protein ◽  
Potential Therapeutic Target ◽  
Related Cell ◽  
Autophagy Inhibition

AbstractColorectal cancer (CRC) is one of the most aggressive and lethal cancers. The role of autophagy in the pathobiology of CRC is intricate, with opposing functions manifested in different cellular contexts. The Yes-associated protein (YAP), a transcriptional coactivator inactivated by the Hippo tumor-suppressor pathway, functions as an oncoprotein in a variety of cancers. In this study, we found that YAP could negatively regulate autophagy in CRC cells, and consequently, promote tumor progression of CRC in vitro and in vivo. Mechanistically, YAP interacts with TEAD forming a complex to upregulate the transcription of the apoptosis-inhibitory protein Bcl-2, which may subsequently facilitate cell survival by suppressing autophagy-related cell death; silencing Bcl-2 expression could alleviate YAP-induced autophagy inhibition without affecting YAP expression. Collectively, our data provide evidence for YAP/Bcl-2 as a potential therapeutic target for drug exploration against CRC.

scholarly journals Genetic Suppressor Element 1 (GSE1) Promotes the Oncogenic and Recurrent Phenotypes of Castration-Resistant Prostate Cancer by Targeting Tumor-Associated Calcium Signal Transducer 2 (TACSTD2)

Cancers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 3959
Author(s):  
Oluwaseun Adebayo Bamodu ◽  
Yuan-Hung Wang ◽  
Chen-Hsun Ho ◽  
Su-Wei Hu ◽  
Chia-Da Lin ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Disease Progression ◽  
Therapy Resistance ◽  
Calcium Signal ◽  
Signal Transducer ◽  
Castration Resistance ◽  
Castration Resistant

Background: prostate cancer (PCa) is a principal cause of cancer-related morbidity and mortality. Castration resistance and metastasis are clinical challenges and continue to impede therapeutic success, despite diagnostic and therapeutic advances. There are reports of the oncogenic activity of genetic suppressor element (GSE)1 in breast and gastric cancers; however, its role in therapy resistance, metastasis, and susceptibility to disease recurrence in PCa patients remains unclear. Objective: this study investigated the role of aberrantly expressed GSE1 in the metastasis, therapy resistance, relapse, and poor prognosis of advanced PCa. Methods: we used a large cohort of multi-omics data and in vitro, ex vivo, and in vivo assays to investigate the potential effect of altered GSE1 expression on advanced/castration-resistant PCa (CRPC) treatment responses, disease progression, and prognosis. Results: using a multi-cohort approach, we showed that GSE1 is upregulated in PCa, while tumor-associated calcium signal transducer 2 (TACSTD2) is downregulated. Moreover, the direct, but inverse, correlation interaction between GSE1 and TACSTD2 drives metastatic disease, castration resistance, and disease progression and modulates the clinical and immune statuses of patients with PCa. Patients with GSE1highTACSTD2low expression are more prone to recurrence and disease-specific death than their GSE1lowTACSTD2high counterparts. Interestingly, we found that the GSE1–TACSTD2 expression profile is associated with the therapy responses and clinical outcomes in patients with PCa, especially those with metastatic/recurrent disease. Furthermore, we demonstrate that the shRNA-mediated targeting of GSE1 (shGSE1) significantly inhibits cell proliferation and attenuates cell migration and tumorsphere formation in metastatic PC3 and DU145 cell lines, with an associated suppression of VIM, SNAI2, and BCL2 and the concomitant upregulation of TACSTD2 and BAX. Moreover, shGSE1 enhances sensitivity to the antiandrogens abiraterone and enzalutamide in vitro and in vivo. Conclusion: these data provide preclinical evidence of the oncogenic role of dysregulated GSE1–TACSTD2 signaling and show that the molecular or pharmacological targeting of GSE1 is a workable therapeutic strategy for inhibiting androgen-driven oncogenic signals, re-sensitizing CRPC to treatment, and repressing the metastatic/recurrent phenotypes of patients with PCa.

A New In Vitro Model for Predicting the Toxicity of Cosmetic Products

1992 ◽  
Vol 20 (1) ◽  
pp. 138-143
Author(s):  
Maria Carrara ◽  
Lorenzo Cima ◽  
Roberto Cerini ◽  
Maurizio Dalle Carbonare
Keyword(s):  
Cell Culture ◽  
Cultured Cells ◽  
Neutral Red ◽  
Total Protein Content ◽  
Cosmetic Products ◽  
Cell Culture Insert ◽  
A Cell ◽  
Vitro Model ◽  
Cosmetic Emulsions

A method has been developed whereby cosmetic products which are not soluble in water or in alcohol can be brought into contact with cell cultures by being placed in a cell culture insert, which is then placed in the cell culture well. Preliminary experiments were carried out with L929 cells, and cytotoxicity was evaluated by measuring neutral red uptake and the total protein content of treated cultured cells. Encouraging results were obtained in comparisons of three cosmetic emulsions and of one emulsion containing a range of concentrations of two preservatives, Kathon CG and Bronopol.

scholarly journals Antagonism of Adherent Invasive E. coli LF82 With Human α-defensin 5 in the Follicle-associated Epithelium of Patients With Ileal Crohn’s Disease

2020 ◽  
Author(s):  
Lina Y Alkaissi ◽  
Martin E Winberg ◽  
Stéphanie DS Heil ◽  
Staffan Haapaniemi ◽  
Pär Myrelid ◽  
...  
Keyword(s):  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Ex Vivo ◽  
Ussing Chambers ◽  
E Coli ◽  
Follicle Associated Epithelium ◽  
Vitro Model ◽  
Set Up

Abstract Background The first visible signs of Crohn’s disease (CD) are microscopic erosions over the follicle-associated epithelium (FAE). The aim of the study was to investigate the effects of human α-defensin 5 (HD5) on adherent-invasive Escherichia coli LF82 translocation and HD5 secretion after LF82 exposure in an in vitro model of human FAE and in human FAE ex vivo. Methods An in vitro FAE-model was set up by the coculture of Raji B cells and Caco-2-cl1 cells. Ileal FAE from patients with CD and controls were mounted in Ussing chambers. The effect of HD5 on LF82 translocation was studied by LF82 exposure to the cells or tissues with or without incubation with HD5. The HD5 secretion was measured in human FAE exposed to LF82 or Salmonella typhimurium. The HD5 levels were evaluated by immunofluorescence, immunoblotting, and ELISA. Results There was an increased LF82 translocation across the FAE-model compared with Caco-2-cl1 (P < 0.05). Incubation of cell/tissues with HD5 before LF82 exposure reduced bacterial passage in both models. Human FAE showed increased LF82 translocation in CD compared with controls and attenuated passage after incubation with sublethal HD5 in both CD and controls (P < 0.05). LF82 exposure resulted in a lower HD5 secretion in CD FAE compared with controls (P < 0.05), whereas Salmonella exposure caused equal secretion on CD and controls. There were significantly lower HD5 levels in CD tissues compared with controls. Conclusions Sublethal HD5 reduces the ability of LF82 to translocate through FAE. The HD5 is secreted less in CD in response to LF82, despite a normal response to Salmonella. This further implicates the integrated role of antimicrobial factors and barrier function in CD pathogenesis.

The Human Leukemic HL-60 Cell Line: An in Vitro Model for Cell Death Endpoint Identification

1996 ◽  
Vol 24 (4) ◽  
pp. 581-587
Author(s):  
Cristiana Zanetti ◽  
Arrnalaura Stammati ◽  
Orazio Sapora ◽  
Flavia Zucco
Keyword(s):  
Cell Death ◽  
Cell Line ◽  
In Vitro Model ◽  
Leukemia Cell ◽  
Promyelocytic Leukemia ◽  
Leukemia Cell Line ◽  
Cell Type ◽  
Vitro Model ◽  
Promyelocytic Leukemia Cell Line

The aim of this study was to investigate the endpoints related to cell death, either necrosis or apoptosis, induced by four chemicals in the promyelocytic leukemia cell line, HL-60. Cell morphology, DNA fragmentation, cytofluorimetric analysis and oxygen consumption were used to classify the type of cell death observed. In our analysis, we found that not all the selected parameters reproduced the differences observed in the cell death caused by the four chemicals tested. As cell death is a very complex phenomenon, several factors should be taken into account (cell type, exposure time and chemical concentration), if chemicals are to be classified according to differences in the mechanisms more directly involved in cell death.

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