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Scientific Reports May 2021Understanding the platelet activation molecular pathways by characterizing specific protein clusters within platelets is essential to identify the platelet activation...
Understanding the platelet activation molecular pathways by characterizing specific protein clusters within platelets is essential to identify the platelet activation state and improve the existing therapies for hemostatic disorders. Here, we employed various state-of-the-art super-resolution imaging and quantification methods to characterize the platelet spatiotemporal ultrastructural change during the activation process due to phorbol 12-myristate 13-acetate (PMA) stimuli by observing the cytoskeletal elements and various organelles at nanoscale, which cannot be done using conventional microscopy. Platelets could be spread out with the guidance of actin and microtubules, and most organelles were centralized probably due to the limited space of the peripheral thin regions or the close association with the open canalicular system (OCS). Among the centralized organelles, we provided evidence that granules are fused with the OCS to release their cargo through enlarged OCS. These findings highlight the concerted ultrastructural reorganization and relative arrangements of various organelles upon activation and call for a reassessment of previously unresolved complex and multi-factorial activation processes.
Topics: Actin Cytoskeleton; Humans; Organelles; Platelet Activation; Tetradecanoylphorbol Acetate
PubMed: 34006947
DOI: 10.1038/s41598-021-89799-9 -
Neurotoxicology Dec 2022Amphetamine (AMPH) causes the degeneration of dopamine terminals in the central nervous system. The mechanisms for this damage are unclear. We found AMPH reduced level...
Amphetamine (AMPH) causes the degeneration of dopamine terminals in the central nervous system. The mechanisms for this damage are unclear. We found AMPH reduced level of GAP-43 in the striatum of rats that receives rich dopaminergic terminals. Using PC12 cells as dopaminergic neuronal models, we further found that AMPH inhibited GAP-43 and GAP-43 phosphorylation in PC12 cells. The reduced GAP-43 was correlated with neurite injury of PC12 cells. The PKCβ1, an upstream molecule of GAP-43, was also inhibited by AMPH. Phorbol 12-myristate 13-acetate (PMA) as a specific activator of PKC increased levels of PKCβ1 and GAP-43, and efficiently prevented neurite degeneration of PC12 cells induced by AMPH. On the other side, enzastuarin, an inhibitor of PKC, decreased levels of PKCβ1 and GAP-43, and caused neurite injury of PC12 cells. Together, our results suggest that AMPH induces neurite injury in PC12 cells through inhibiting PKCβ1/GAP-43 pathway.
Topics: Animals; Rats; Amphetamine; PC12 Cells; Neurites; GAP-43 Protein; Tetradecanoylphorbol Acetate; Dopamine
PubMed: 36150536
DOI: 10.1016/j.neuro.2022.09.004 -
IUBMB Life Nov 2008
Review
Topics: Canada; Catalysis; Enzyme Activation; History, 20th Century; History, 21st Century; Models, Biological; Phosphorylation; Protein Binding; Protein Conformation; Protein Kinase C; Tetradecanoylphorbol Acetate
PubMed: 18683875
DOI: 10.1002/iub.118 -
Theranostics 2022Insulin-like growth factor 1 receptor (IGF-1R) expression and signaling play important roles in promotion of skin cancer progression. Identification of signaling...
Insulin-like growth factor 1 receptor (IGF-1R) expression and signaling play important roles in promotion of skin cancer progression. Identification of signaling pathways that regulate IGF-1R is crucial for understanding the pathogenesis and therapeutic treatment of skin cancer. Molecular, cellular and genetic approaches were used to investigate the function of PINCH-1 in regulation of IGF-1R expression and skin cell behavior. Furthermore, conditional PINCH-1 knockout mouse and carcinogen (7, 12-dimethylbenz[a]anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA))-induced skin cancer model were employed to determine the function of PINCH-1 in regulation of IGF-1R expression and skin carcinogenesis . Knockdown of PINCH-1 from HaCaT keratinocytes or A431 squamous carcinoma cells diminished IGF-1R levels, suppressed cell proliferation and increased apoptosis. Re-expression of PINCH-1 in PINCH-1 knockdown cells restored IGF-1R expression, cell proliferation and survival. Furthermore, depletion of NEDD4 effectively reversed PINCH-1 deficiency-induced down-regulation of IGF-1R expression, cell proliferation and survival. Conditional knockout of PINCH-1 from keratin 5 (K5) positive keratinocytes in mice, like depletion of PINCH-1 from keratinocytes in culture, reduced the IGF-1R level. Using a mouse model of DMBA/TPA-induced skin cancer, we show that the levels of both PINCH-1 and IGF-1R were significantly increased in response to treatment with the carcinogens. Genetic ablation of PINCH-1 from the epidermis markedly reduced the IGF-1R expression and cell proliferation despite stimulation with DMBA/TPA, resulting in resistance to chemical carcinogen-induced skin cancer initiation and progression. Our results reveal a PINCH-1-NEDD4-IGF-1R signaling axis that is critical for promotion of skin tumorigenesis and suggest a new strategy for therapeutic control of skin cancer progression.
Topics: Animals; Carcinogenesis; Carcinogens; Cell Proliferation; GRB10 Adaptor Protein; Keratinocytes; Mice; Receptor, IGF Type 1; Skin; Skin Neoplasms; Tetradecanoylphorbol Acetate
PubMed: 35401828
DOI: 10.7150/thno.70744 -
The Turkish Journal of Gastroenterology... Nov 2020The study aimed to explore the effects of Epstein-Barr virus--encoded BARF1 in human gastric epithelial cells (GES-1).
BACKGROUND/AIMS
The study aimed to explore the effects of Epstein-Barr virus--encoded BARF1 in human gastric epithelial cells (GES-1).
MATERIALS AND METHODS
A eukaryotic expression vector carrying BARF1 gene (pcDNA3.1-BARF1) was constructed. The pcDNA3.1-BARF1 was transfected into GES-1 cells, and they were selected by G418. The GES-1 cells lines that expressed BARF1 (GES-1-BARF1) were obtained. The cycle of GES-1-pcDNA3.1 cells (GES-1 cells transfected with empty vector), GES-1-BARF1 cells (GES-1 cells transfected with BARF1), and TPA-GES-1-BARF1(GES-1-BARF1 cells stimulated by 12-O-tetradecanoylphorbol-13-acetate (TPA) were analyzed by flow cytometry. Colony formation in soft agar and tumorigenicity of the transfected cells in mice with severe combined immunodeficiency (SCID) were also observed.
RESULTS
The morphology of GES-1-BARF1 cells were changed from the original shuttle to round, the adhesion between the cells and bottle wall was weakened, and the cells showed overlapping growth. The proliferation rate of GES-1-BARF1 and TPA-GES-1-BARF1 cells were faster than GES-1 and GES-1-pcDNA3.1 cells; the S phase was significantly prolonged for GES-1-BARF1 and TPA-GES-1-BARF1. GES-1-BARF1 and TPA-GES-1-BARF1 cells formed colonies in soft agar, with a cloning rate of 24.2% (58/240) and 40.0% (96/240), respectively; GES-1 and GES-1-pcDNA3.1 cells did not form colonies in soft agar. Tumors were formed in mice with SCID after injecting TPA-GES-1-BARF1 cell groups. Tumor formation did not occur in mice with SCID after injecting GES-1 and GES-1-pcDNA3.1 cell groups, but nodules were formed in the mice with SCID after injecting GES-1-BARF1 cell groups.
CONCLUSION
GES-1-BARF1 cells malignant transformation was induced by transfected BARF1 gene and TPA stimulation. This result indicated that tumor formation not only require oncogenes, but also the stimulation of cancer-promoting substance.
Topics: Animals; Carcinogenesis; Disease Models, Animal; Epithelial Cells; Gastric Mucosa; Herpesvirus 4, Human; Humans; Mice; Severe Combined Immunodeficiency; Tetradecanoylphorbol Acetate; Transfection; Viral Proteins
PubMed: 33361040
DOI: 10.5152/tjg.2020.18827 -
Brazilian Journal of Biology = Revista... 2022Neutrophil extracellular traps (NETs) were first reported as a microbicidal strategy for activated neutrophils. Through an immunologic response against several stimuli,...
Quercetin inhibits neutrophil extracellular traps release and their cytotoxic effects on A549 cells, as well the release and enzymatic activity of elastase and myeloperoxidase.
Neutrophil extracellular traps (NETs) were first reported as a microbicidal strategy for activated neutrophils. Through an immunologic response against several stimuli, neutrophils release their DNA together with proteins from granules, nucleus, and cytoplasm (e.g., elastase and myeloperoxidase). To date, NETs have been implicated in tissue damage during intense inflammatory processes, mainly when their release is dependent on oxygen radical generation. Flavonoids are antioxidant and anti-inflammatory agents; of these, quercetin is commonly found in our daily diet. Therefore, quercetin could exert some protective activity against tissue damage induced by NETs. In our in vitro assays, quercetin reduced NETs, myeloperoxidase (MPO), and elastase release from neutrophils stimulated with phorbol 12-myristate 13-acetate (PMA). The activity of these enzymes also decreased in the presence of quercetin. Quercetin also reduced the cytotoxic effect of NETs on alveolar cells (A549 cell line). Further, in silico assays indicated favorable interactions between quercetin and NET proteins (MPO and elastase). Overall, our results demonstrate that quercetin decreases deleterious cellular effects of NETs by reducing their release from activated neutrophils, and diminishing the enzymatic activity of MPO and elastase, possibly through direct interaction.
Topics: A549 Cells; Extracellular Traps; Humans; Pancreatic Elastase; Peroxidase; Quercetin; Tetradecanoylphorbol Acetate
PubMed: 35475990
DOI: 10.1590/1519-6984.252936 -
Mikrobiyoloji Bulteni Apr 2018Macrophages are accepted as cells that initially contact with the pathogens and initiate the innate immune response. They play effective roles in innate immune and...
Macrophages are accepted as cells that initially contact with the pathogens and initiate the innate immune response. They play effective roles in innate immune and inflammatory responses by intercellular relations and inflammatory mediator secretion. Human THP-1 leukemia cells are frequently used for the in vitro determination of the signal pathways, and the functions of macrophages. Phorbol-12-Myristate-13-Acetate (PMA) is commonly used to induce macrophage differentiation of monocytic cell lines but the extent of differentiation in comparison to primary tissue macrophages is unclear. Midkine acts as a cytokine and growth factor which organizes proliferation, differentiation, survival, adhesion and migration of immune cells. The aim of this study was to observe the differences in the secretion of midkine, TNF-α, IL-10 and IFN-γ of macrophages differentiated from monocytes when stimulated with different doses of PMA for different durations. For this purpose, THP-1 monocytic cells were proliferated by PMA at 24, 48 and 72 hours by using the concentrations of 10 ng/ml, 20 ng/ml, 40 ng/ml and 60 ng/ ml. Midkine, TNF-α, IL-10 and IFN-γ cytokine levels were determined by ELISA in the supernatants of the cells collected at the end of incubation times. PMA stimuli initiated changes that were indicative of differentiation in the cell morphology. Differentiation of cells by PMA induced midkine, TNF-α, IL-10 and IFN-γ secretions in monocytic cells even at the lowest dosage (10 ng/ml). PMA caused cytotoxicity in the cells when the dosages were increased (> 20 ng/ml). THP-1 cells have a basal secretion of midkine and are increased by dosage dependent with PMA stimulation. Midkine secretion has shown changes dependent with dosage and time. A difference was also observed in the cytokine profile of PMA stimulated cells at different doses. The results indicated that the differentiation of THP-1 monocytes to macrophages requires optimization to ensure that this in vitro macrophage model more precisely reflects real in vivo physiologic conditions. As a conclusion the results have shown that a modified PMA differentiation protocol (20 ng/ml and 48 hours incubation) might enhance macrophage differentiation of THP-1 cells without induced cell death (viability 92.2%) and cytokine secretion and midkine responses were the important discriminators of the level of macrophage differentiation.
Topics: Carcinogens; Cytokines; Humans; Macrophages; Midkine; Monocytes; THP-1 Cells; Tetradecanoylphorbol Acetate; Time Factors
PubMed: 29933732
DOI: 10.5578/mb.66745 -
Anais Da Academia Brasileira de Ciencias 2023Dermatitis is defined as a set of inflammatory diseases that affect the skin, with varied causes. Among the different types of dermatitis, contact dermatitis is the most...
Dermatitis is defined as a set of inflammatory diseases that affect the skin, with varied causes. Among the different types of dermatitis, contact dermatitis is the most prevalent. Although the current therapy is often effective, it is associated with adverse effects and the possibility of drug tolerance. N-Methyl-(2S, 4R)-trans-4-hydroxy-L-proline is a L-proline amino acid derivative found in the leaves of Sideroxylon obtusifolium, a species traditionally used to treat inflammatory diseases. The aim of this study was to investigate the topical anti-inflammatory effect of N-methyl-(2S, 4R)-trans-4-hydroxy-L-proline (NMP) in 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced irritant contact dermatitis in mice. Topically administered NMP, at doses of 0.03 - 0.50 mg/ear, reduced TPA-induced ear edema and neutrophil migration, as evidenced by low tissue myeloperoxidase activity and verified by histological examination. In addition, NMP (0.06 mg/ear) reduced tissue levels of pro-inflammatory cytokines (TNF-α, IL-6, IL-1β, INF-γ and MCP-1) and of the anti-inflammatory cytokine IL-10, and reduced gene expression of TNF-α, IL-6 and IL-1β increased by TPA. The data suggest that N-methyl-(2S, 4R)-trans-4-hydroxy-L-proline acts as a topical anti-inflammatory agent that decreases the expression of inflammatory cytokines, making it useful for the treatment of skin inflammation. Further investigations are necessary for its development as a therapeutic agent.
Topics: Mice; Animals; Tetradecanoylphorbol Acetate; Irritants; Tumor Necrosis Factor-alpha; Interleukin-6; Dermatitis, Contact; Anti-Inflammatory Agents; Dermatitis; Cytokines; Sapotaceae
PubMed: 37909544
DOI: 10.1590/0001-3765202320220919 -
Biological & Pharmaceutical Bulletin Oct 2017α-Cyperone, a sesquiterpene compound represents 25.23% of the total oil and is the most abundant compound in Cyperus rotundus oil. Endothelial cell protein C receptor...
α-Cyperone, a sesquiterpene compound represents 25.23% of the total oil and is the most abundant compound in Cyperus rotundus oil. Endothelial cell protein C receptor (EPCR) is a main member in protein C (PC) anti-coagulation system. EPCR could be shed from cell surface, and is mediated by tumor necrosis factor-α converting enzyme (TACE). Nothing that EPCR is a marker of vascular barrier integrity in vascular inflammatory disease and takes part in systemic inflammatory disease. In this study, we investigated whether α-cyperone could inhibit EPCR shedding. To observe the effect, we investigated this issue by detection the effect of α-cyperone on phorbol-12-myristate 13-acetate (PMA)-induced EPCR shedding in human umbilical vein endothelial cells (HUVECs). The cells were pretreated with α-cyperone for 12 h, and then stimulated by PMA for 1 h. The solute EPCR (sEPCR) and expression of membrane EPCR (mEPCR) were measured by enzyme-linked immunosorbent assay (ELISA) and Western blot. The mRNA, protein level and activity of TACE were tested by quantitative (q)RT-PCR, Western blot and InnoZyme TACE activity assay kit. Furthermore, we measured the protein level of mitogen-activated protein kinase (MAPK) signaling and protein kinase C (PKC) pathway under this condition by Western blot. The results showed that α-cyperone could suppress PMA-induced EPCR shedding through inhibiting the expression and activity of TACE. In addition, α-cyperone could inhibit PKC translocation, but not have an effect on phosphorylation of c-Jun N-terminal kinase (JNK), p38 and extracellular regulated protein kinases (ERK) 1/2. Given these results, α-cyperone inhibits PMA-induced EPCR shedding through PKC pathway, which will provide an experimental basis for further research on α-cyperone.
Topics: ADAM17 Protein; Cell Survival; Endothelial Protein C Receptor; Human Umbilical Vein Endothelial Cells; Humans; Indoles; JNK Mitogen-Activated Protein Kinases; MAP Kinase Signaling System; Maleimides; Mitogen-Activated Protein Kinases; Naphthalenes; Phosphorylation; Protein Kinase C; Tetradecanoylphorbol Acetate; p38 Mitogen-Activated Protein Kinases
PubMed: 28804104
DOI: 10.1248/bpb.b17-00183 -
Frontiers in Immunology 2022Neutrophils constitute abundant cellular components in atherosclerotic plaques. Most of the current studies are focused on the roles of granular proteins released by...
Neutrophils constitute abundant cellular components in atherosclerotic plaques. Most of the current studies are focused on the roles of granular proteins released by neutrophils in atherosclerosis. Here, we revealed a unique subset of neutrophils which exhibit the characteristics of antigen-presenting cell (APC) (which were called APC-like neutrophils afterwards) in atherosclerosis. The roles of APC-like neutrophils and relevant mechanisms were investigated in hyperlipidemic patients and atherosclerotic mice. Higher percentages of neutrophils and APC-like neutrophils were found in peripheral blood of hyperlipidemic patients than that of healthy donors. Meanwhile, we also identified higher infiltration of neutrophils and APC-like neutrophils in atherosclerotic mice. Ox-LDL induced Phorbol-12-myristate-13-acetate (PMA)-activated neutrophils to acquire the APC-like phenotype. Importantly, upon over-expression of APC-like markers, neutrophils acquired APC functions to promote the proliferation and interferon-γ production of CD3 T cells HLA-DR/CD80/CD86. In accordance with what found , positive correlation between neutrophils and CD3 T cells was observed in hyperlipidemic patients. In conclusion, our work identifies a proinflammatory neutrophil subset in both hyperlipidemic patients and atherosclerotic mice. This unique phenotype of neutrophils could activate the adaptive immune response to promote atherosclerosis progression. Thus, this neutrophil subset may be a new target for immunotherapy of atherosclerosis.
Topics: Animals; Antigen-Presenting Cells; Atherosclerosis; Humans; Lymphocyte Activation; Mice; Neutrophils; T-Lymphocytes; Tetradecanoylphorbol Acetate
PubMed: 35251050
DOI: 10.3389/fimmu.2022.851713