In Vivo Interactions with (Tissue Culture Pretreated) Dermal Sheep Collagen

1991 ◽  
Vol 252 ◽  
Author(s):  
P. B. van Wachem ◽  
P. B. van Wachem ◽  
L. H. H. Olde Damink ◽  
P. J. Dijkstra ◽  
J. Feijen ◽  
...  
Keyword(s):  
Tissue Culture ◽  
Cell Death ◽  
Marked Reduction ◽  
Giant Cells ◽  
In Vitro Cytotoxicity ◽  
Cell Infiltration ◽  
Cytotoxic Effects ◽  
Lipid Formation

ABSTRACTPretreatment in tissue culture (TC) was previously found to markedly reduce the in vitro cytotoxicity of two types of crosslinked dermal sheep collagens (DSC's). This in vivo study confirms our in vitro results, in that TC-pretreatment of crosslinked DSC's resulted in the marked reduction or elimination of cytotoxic effects, such as increased cell infiltration, a deviant neutrophil-morphology, lipid formation and cell death. TC-pretreatment affected the crosslinked state of both DSC's in a different way, which could be deduced from the differences in gelatin-formation and presence of giant cells from macrophage- or fibroblast-origin. The results are explained in view of the differences in crosslinking.

scholarly journals Calcium Binding of ARC Mediates Regulation of Caspase 8 and Cell Death

2004 ◽  
Vol 24 (22) ◽  
pp. 9763-9770 ◽  
Author(s):  
Dong-Gyu Jo ◽  
Joon-Il Jun ◽  
Jae-Woong Chang ◽  
Yeon-Mi Hong ◽  
Sungmin Song ◽  
...  
Keyword(s):  
Cell Death ◽  
Calcium Binding ◽  
Ectopic Expression ◽  
Hek293 Cells ◽  
Caspase 8 ◽  
Cytotoxic Effects ◽  
Protein Protein Interaction ◽  
Rich Domain

ABSTRACT Apoptosis repressor with CARD (ARC) possesses the ability not only to block activation of caspase 8 but to modulate caspase-independent mitochondrial events associated with cell death. However, it is not known how ARC modulates both caspase-dependent and caspase-independent cell death. Here, we report that ARC is a Ca2+-dependent regulator of caspase 8 and cell death. We found that in Ca2+ overlay and Stains-all assays, ARC protein bound to Ca2+ through the C-terminal proline/glutamate-rich (P/E-rich) domain. ARC expression reduced not only cytosolic Ca2+ transients but also cytotoxic effects of thapsigargin, A23187, and ionomycin, for which the Ca2+-binding domain of ARC was indispensable. Conversely, direct interference of endogenous ARC synthesis by targeting ARC enhanced such Ca2+-mediated cell death. In addition, binding and immunoprecipitation analyses revealed that the protein-protein interaction between ARC and caspase 8 was decreased by the increase of Ca2+ concentration in vitro and by the treatment of HEK293 cells with thapsigargin in vivo. Caspase 8 activation was also required for the thapsigargin-induced cell death and suppressed by the ectopic expression of ARC. These results suggest that calcium binding mediates regulation of caspase 8 and cell death by ARC.

scholarly journals Leptin Induces Apoptotic and Pyroptotic Cell Death via NLRP3 Inflammasome Activation in Rat Hepatocytes

2021 ◽  
Vol 22 (22) ◽  
pp. 12589
Author(s):  
Ananda Baral ◽  
Pil-Hoon Park
Keyword(s):  
Cell Death ◽  
Rat Hepatocytes ◽  
Inflammasome Activation ◽  
Cytotoxic Effects ◽  
Nlrp3 Inflammasome Activation ◽  
Critical Components ◽  
Underlying Mechanisms ◽  
Nlrp3 Inflammasomes

Leptin, a hormone that is predominantly produced by adipose tissue, is closely associated with various liver diseases. However, there is a lack of understanding as to whether leptin directly induces cytotoxic effects in hepatocytes as well as the mechanisms that are involved. Inflammasomes, which are critical components in the innate immune system, have been recently shown to modulate cell death. In this study, we examined the effect of leptin on the viability of rat hepatocytes and the underlying mechanisms, with a particular focus on the role of inflammasomes activation. Leptin treatment induced cytotoxicity in rat hepatocytes, as determined by decreased cell viability, increased caspase-3 activity, and the enhanced release of lactate dehydrogenase. NLRP3 inflammasomes were activated by leptin both in vitro and in vivo, as determined by the maturation of interleukin-1β and caspase-1, and the increased expression of inflammasome components, including NLRP3 and ASC. Mechanistically, leptin-induced inflammasome activation is mediated via the axis of ROS production, ER stress, and autophagy. Notably, the inhibition of inflammasomes by treatment with the NLRP3 inhibitor or the IL-1 receptor antagonist protected the hepatocytes from leptin-induced cell death. Together, these results indicate that leptin exerts cytotoxic effects in hepatocytes, at least in part, via the activation of NLRP3 inflammasomes.

Can the In Vivo Maximum Tolerated Dose be Predicted Using In Vitro Techniques? A Working Hypothesis

1991 ◽  
Vol 19 (4) ◽  
pp. 393-402
Author(s):  
Ravi Shrivastava ◽  
Gareth W. John ◽  
Ginette Rispat ◽  
Annick Chevalier ◽  
Roy Massingham
Keyword(s):  
Cell Death ◽  
Research Effort ◽  
Maximum Tolerated Dose ◽  
In Vitro Cytotoxicity ◽  
Toxicity Tests ◽  
In Vitro Toxicity ◽  
Working Hypothesis ◽  
Wide Range

All new chemical entities synthesised in our laboratories have routinely been subjected to in vitro toxicity tests. Out of curiosity, we established a working hypothesis in which the in vitro data could be empirically transformed to predict the in vivo four-week standard maximum tolerated dose (MTD) studies in rats and dogs. As a first step to verifying this hypothesis, we report here the findings of an in vitro cytotoxicity study of 25 compounds randomly selected from our files, possessing a wide range of pharmacological activities and for which data from standard four-week MTD studies were available. Single blind in vitro toxicity studies in three carefully selected types of primary and cell line cultures were carried out. In vitro CT50 (concentration inducing 50% cell death) and CT100 (concentration inducing 100% cell death) values were obtained for each of the three cell types and, using empirical assumptions, these results were used to predict the MTD in vivo in the rat and dog. The actual in vivo threshold and toxic doses were obtained from the MTD study reports. The in vivo toxicity values predicted from the in vitro toxicity results with this series of 25 compounds showed a better than 80% correlation with the actual in vivo results obtained in the MTD studies. Whether or not in vitro cytotoxicity predictions are ultimately found to be directly and consistently related to the MTD in vivo for all pharmacological classes of compounds will require many additional studies, but it is hoped that these results will stimulate the necessary research effort required to answer this question.

Development of Calendula Oil/Chitosan Microcapsules and their Biological Safety Evaluation

2012 ◽  
Vol 65 (1) ◽  
pp. 72 ◽  
Author(s):  
Pik Ling Lam ◽  
Marcus Chun Wah Yuen ◽  
Chi Wai Kan ◽  
Raymond Siu Ming Wong ◽  
Gregory Yin Ming Cheng ◽  
...  
Keyword(s):  
Ph Value ◽  
Optimal Parameter ◽  
Drug Carrier ◽  
Safety Evaluation ◽  
Human Keratinocytes ◽  
Processing Parameters ◽  
In Vitro Cytotoxicity ◽  
Cytotoxic Effects

Chitosan microcapsules containing calendula oil are prepared by a simple coacervation method. The results show that the performance of the microcapsules, including encapsulation efficiency and particle size, is affected by the change of various processing parameters of microcapsule manufacture. Under the optimal parameter combinations: the chitosan concentration is 1.5 % w/v; the core/wall ratio is 0.1 g mL–1; the stirring speed is 1200 rpm; and the pH value is 10. The compositions and surface morphology of the microcapsules are examined using scanning electron microscope and FTIR spectroscopy. The in vitro cytotoxicity evaluation demonstrates that the microcapsules exhibit no significant cytotoxic effects on human keratinocytes. The in vivo toxicology analysis on mice proves that the microcapsules do not exert any significant necrosis to the liver. It is suggested that our microcapsules could be used as a safe drug carrier both topically and orally.

scholarly journals ETV2 regulates PARP-1 binding protein to induce ER stress-mediated cell death in tuberin-deficient cells

2021 ◽  
Author(s):  
Shikshya Shrestha ◽  
Anthony Lamattina ◽  
Gustavo Pacheco-Rodriguez ◽  
Julie Ng ◽  
Xiaoli Liu ◽  
...  
Keyword(s):  
Cell Death ◽  
Er Stress ◽  
Binding Protein ◽  
Cytotoxic Effects ◽  
Signaling Axis ◽  
Mrna And Protein Expression ◽  
Potential Alternative ◽  
Parp 1

Lymphangioleiomyomatosis (LAM) is a rare progressive disease, characterized by mutations in the tuberous sclerosis complex genes (Tsc1 or Tsc2), and hyperactivation of mechanistic target of rapamycin complex 1 (mTORC1). The effectiveness of mTORC1 inhibitors is limited by their lack of cytotoxic effects. Here, we report that E26 transformation specific (ETS) Variant Transcription Factor 2 (ETV2) is a critical regulator of Tsc2–deficient cell survival. Nuclear localization of ETV2 in Tsc2–deficient cells is mTORC1–independent and is enhanced by spleen tyrosine kinase (Syk) inhibition. In the nucleus, ETV2 transcriptionally regulates poly(ADP-ribose) polymerase 1 binding protein (PARPBP), a coregulator of transcription, mRNA and protein expression. Silencing of ETV2 or PARPBP in Tsc2–deficient cells induced ER-stress and increased cell death in vitro and in vivo. We also found ETV2 expression in human cells with loss of heterozygosity for TSC2 lending support to the translational relevance of our findings. In conclusion, we report a novel signaling axis unique to Syk-inhibition is mTORC1–independent and promotes a cytocidal response in Tsc2–deficient cells, and therefore, maybe a potential alternative therapeutic target in LAM.

Abstract 270: Role of the Mitochondrial Iron in Cardiomyoblast Survival and Maturation of Cytosolic Fe/S Proteins.

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Anita Thakur ◽  
Marina Bayeva ◽  
Hossein Ardehali
Keyword(s):  
Cell Death ◽  
Iron Accumulation ◽  
Iron Chelators ◽  
Inner Mitochondrial Membrane ◽  
Cytotoxic Effects ◽  
Mitochondrial Iron ◽  
S Proteins

ATP-binding cassette (ABC)-B8 is an ABC half transporter that resides in the inner mitochondrial membrane. We previously showed that ABCB8 has a role in mitochondrial iron export, and that a reduction in ABCB8 both in vitro and in vivo results in mitochondrial iron accumulation, increased reactive oxygen species (ROS) and cell death, and decreased activity of cytosolic Fe/S proteins. However, it is not known whether the cytotoxic effects of ABCB8 knockdown are due to mitochondrial iron accumulation or decreased cytosolic Fe/S protein or other processes. Furthermore, the link between mitochondrial iron and the activity of cytosolic Fe/S proteins is uncharacterized. Here, we studied whether a reduction in mitochondrial iron can reverse the effects of ABCB8 knockdown on cell survival, ROS production and the activity of Fe/S proteins. We altered the mitochondrial iron using various iron chelators and by decreasing the levels of mitochondrial iron importer, mitoferrin-2 (MFRN2). The increase in mitochondrial iron and ROS levels associated with ABCB8 knockdown was significantly reversed by iron chelators and with MFRN-2 knockdown. Furthermore, cell death was also reversed with iron chelators and MFRN-2 knockdown, suggesting that the cytotoxic effects of ABCB8 knockdown is due to mitochondrial iron accumulation. We then studied the effects of iron chelators on cytosolic Fe/S proteins. Iron chelators reversed the defect in cytosolic Fe/S proteins that is associated with ABCB8 knockdown in cell culture or knockout in mice. However, antioxidants and knockdown of MFRN-2 failed to have similar effects. These results indicated that the defect in the maturation of cytosolic Fe/S proteins due to mitochondrial iron accumulation can be reversed by chelating mitochondrial iron, and is independent of the associated oxidative stress. Thus, mitochondrial iron levels are likely sensed in the cytoplasm and determine the maturation of cytosolic Fe/S proteins. Altogether, these studies provide insights into the role of mitochondrial iron in the cytotoxic effects of ABCB8 knockdown, and suggest that mitochondrial iron is sensed in the cytoplasm and influences the maturation of cytosolic Fe/S proteins.

In vitro Cytotoxicity and Genotoxicity Analysis of Ten Tannery Chemicals Using SOS/umu Tests and High-content In vitro Micronucleus Tests

2018 ◽  
Vol 21 (4) ◽  
pp. 262-270 ◽  
Author(s):  
Zehao Huang ◽  
Na Li ◽  
Kaifeng Rao ◽  
Cuiting Liu ◽  
Zijian Wang ◽  
...  
Keyword(s):  
Micronucleus Test ◽  
A549 Cells ◽  
Quantitative Structure Activity Relationship ◽  
In Vitro Cytotoxicity ◽  
Cytotoxic Effects ◽  
Qsar Analysis ◽  
Cell Assays ◽  
Micronucleus Tests ◽  
Damaging Effects

Background: More than 2,000 chemicals have been used in the tannery industry. Although some tannery chemicals have been reported to have harmful effects on both human health and the environment, only a few have been subjected to genotoxicity and cytotoxicity evaluations. Objective: This study focused on cytotoxicity and genotoxicity of ten tannery chemicals widely used in China. Materials and Methods: DNA-damaging effects were measured using the SOS/umu test with Salmonella typhimurium TA1535/pSK1002. Chromosome-damaging and cytotoxic effects were determined with the high-content in vitro Micronucleus test (MN test) using the human-derived cell lines MGC-803 and A549. Conclusion: The cytotoxicity of the ten tannery chemicals differed somewhat between the two cell assays, with A549 cells being more sensitive than MGC-803 cells. None of the chemicals induced DNA damage before metabolism, but one was found to have DNA-damaging effects on metabolism. Four of the chemicals, DY64, SB1, DB71 and RR120, were found to have chromosome-damaging effects. A Quantitative Structure-Activity Relationship (QSAR) analysis indicated that one structural feature favouring chemical genotoxicity, Hacceptor-path3-Hacceptor, may contribute to the chromosome-damaging effects of the four MN-test-positive chemicals.

Mixed Micelles as Nano Polymer Therapeutics of Docetaxel: Increased In vitro Cytotoxicity and Decreased In vivo Toxicity

2018 ◽  
Vol 15 (4) ◽  
pp. 564-575 ◽  
Author(s):  
Arehalli S. Manjappa ◽  
Popat S. Kumbhar ◽  
Prajakta S. Khopade ◽  
Ajit B. Patil ◽  
John I. Disouza
Keyword(s):  
Mixed Micelles ◽  
In Vitro Cytotoxicity ◽  
Polymer Therapeutics ◽  
In Vivo Toxicity

Mannose Conjugated Starch Nanoparticles for Preferential Targeting of Liver Cancer

2020 ◽  
Vol 17 ◽  
Author(s):  
Akhlesh Kumar Jain ◽  
Hitesh Sahu ◽  
Keerti Mishra ◽  
Suresh Thareja
Keyword(s):  
Side Effects ◽  
Liver Cancer ◽  
Entrapment Efficiency ◽  
Xrd Analysis ◽  
In Vitro Cytotoxicity ◽  
Physical Interaction ◽  
Scanning Calorimetry ◽  
Starch Nanoparticles

Aim: To design D-Mannose conjugated 5-Fluorouracil (5-FU) loaded Jackfruit seed starch nanoparticles (JFSSNPs) for site specific delivery. Background: Liver cancer is the third leading cause of death in world and fifth most often diagnosed cancer is the major global threat to public health. Treatment of liver cancer with conventional method bears several side effects, thus to undertake these side effects as a formulation challenge, it is necessary to develop novel target specific drug delivery system for the effective and better localization of drug into the proximity of target with restricting the movement of drug in normal tissues. Objective: To optimize and characterize the developed D-Mannose conjugated 5-Fluorouracil (5-FU) loaded Jackfruit seed starch nanoparticles (JFSSNPs) for effective treatment of liver cancer. Materials and methods: 5-FU loaded JFSSNPs were prepared and optimized formulation had higher encapsulation efficiency were conjugated with D-Mannose. These formulations were characterized for size, morphology, zeta potential, X-Ray Diffraction, and Differential Scanning Calorimetry. Potential of NPs were studied using in vitro cytotoxicity assay, in vivo kinetic studies and bio-distribution studies. Result and discussion: 5-Fluorouracil loaded NPs had particle size between 336 to 802nm with drug entrapment efficiency was between 64.2 to 82.3%. In XRD analysis, 5-FU peak was diminished in the diffractogram, which could be attributed to the successful incorporation of drug in amorphous form. DSC study suggests there was no physical interaction between 5- FU and Polymer. NPs showed sustained in vitro 5-FU release up to 2 hours. In vivo, mannose conjugated NPs prolonged the plasma level of 5-FU and assist selective accumulation of 5-FU in the liver (vs other organs spleen, kidney, lungs and heart) compared to unconjugated one and plain drug. Conclusion: In vivo, bio-distribution and plasma profile studies resulted in significantly higher concentration of 5- Fluorouracil liver suggesting that these carriers are efficient, viable, and targeted carrier of 5-FU treatment of liver cancer.

scholarly journals TNF-α Triggers RIP1/FADD/Caspase-8-Mediated Apoptosis of Astrocytes and RIP3/MLKL-Mediated Necroptosis of Neurons Induced by Angiostrongylus cantonensis Infection

2021 ◽  
Author(s):  
Hongli Zhou ◽  
Minyu Zhou ◽  
Yue Hu ◽  
Yanin Limpanon ◽  
Yubin Ma ◽  
...  
Keyword(s):  
Cell Death ◽  
Enrichment Analysis ◽  
Angiostrongylus Cantonensis ◽  
Gene Set Enrichment Analysis ◽  
Caspase 8 ◽  
Cns Injury ◽  
Vitro Assay ◽  
Tnf Α

AbstractAngiostrongylus cantonensis (AC) can cause severe eosinophilic meningitis or encephalitis in non-permissive hosts accompanied by apoptosis and necroptosis of brain cells. However, the explicit underlying molecular basis of apoptosis and necroptosis upon AC infection has not yet been elucidated. To determine the specific pathways of apoptosis and necroptosis upon AC infection, gene set enrichment analysis (GSEA) and protein–protein interaction (PPI) analysis for gene expression microarray (accession number: GSE159486) of mouse brain infected by AC revealed that TNF-α likely played a central role in the apoptosis and necroptosis in the context of AC infection, which was further confirmed via an in vivo rescue assay after treating with TNF-α inhibitor. The signalling axes involved in apoptosis and necroptosis were investigated via immunoprecipitation and immunoblotting. Immunofluorescence was used to identify the specific cells that underwent apoptosis or necroptosis. The results showed that TNF-α induced apoptosis of astrocytes through the RIP1/FADD/Caspase-8 axis and induced necroptosis of neurons by the RIP3/MLKL signalling pathway. In addition, in vitro assay revealed that TNF-α secretion by microglia increased upon LSA stimulation and caused necroptosis of neurons. The present study provided the first evidence that TNF-α was secreted by microglia stimulated by AC infection, which caused cell death via parallel pathways of astrocyte apoptosis (mediated by the RIP1/FADD/caspase-8 axis) and neuron necroptosis (driven by the RIP3/MLKL complex). Our research comprehensively elucidated the mechanism of cell death after AC infection and provided new insight into targeting TNF-α signalling as a therapeutic strategy for CNS injury.

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