scholarly journals Understanding delayed fluorescence and triplet decays of Protoporphyrin IX under hypoxic conditions

2021 ◽  
Author(s):  
Marek Scholz ◽  
Gauthier Croizat ◽  
Jakub Pšenčík ◽  
Roman Dědic ◽  
Santi Nonell ◽  
...  
Keyword(s):  
Protoporphyrin Ix ◽  
Delayed Fluorescence ◽  
Hypoxic Conditions

Singlet oxygen feedback delayed fluorescence of protoporphyrin IX in organic solutions

2017 ◽  
Vol 16 (4) ◽  
pp. 507-518 ◽  
Author(s):  
Ivo S. Vinklárek ◽  
Marek Scholz ◽  
Roman Dědic ◽  
Jan Hála
Keyword(s):  
Partial Pressure ◽  
Singlet Oxygen ◽  
Protoporphyrin Ix ◽  
Clinical Applications ◽  
Delayed Fluorescence ◽  
Diagnostic Tools ◽  
Partial Pressure Of Oxygen ◽  
High Concentrations ◽  
Organic Solutions

The PpIX DF show the significant role of SOFDF mechanism at high concentrations and at atmospheric partial pressure of oxygen and should be considered when developing diagnostic tools for clinical applications.

Real-time,in vivomeasurement of tissular pO2 through the delayed fluorescence of endogenous protoporphyrin IX during photodynamic therapy

2012 ◽  
Vol 17 (11) ◽  
pp. 115007 ◽  
Author(s):  
Filippo Piffaretti ◽  
Anna Maria Novello ◽  
Rajendran Senthil Kumar ◽  
Eddy Forte ◽  
Cédric Paulou ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Real Time ◽  
Protoporphyrin Ix ◽  
Delayed Fluorescence

scholarly journals A general framework for non-exponential delayed fluorescence and phosphorescence decay analysis, illustrated on Protoporphyrin IX

2020 ◽  
Vol 209 ◽  
pp. 111887
Author(s):  
Gauthier Croizat ◽  
Aurélien Gregor ◽  
Emmanuel Gerelli ◽  
Jaroslava Joniova ◽  
Marek Scholz ◽  
...  
Keyword(s):  
General Framework ◽  
Protoporphyrin Ix ◽  
Delayed Fluorescence ◽  
Phosphorescence Decay ◽  
Fluorescence And Phosphorescence

pO2-weighted imaging in vivo by delayed fluorescence of intracellular protoporphyrin IX: publisher’s note

2020 ◽  
Vol 45 (3) ◽  
pp. 664 ◽  
Author(s):  
Marek Scholz ◽  
Xu Cao ◽  
Jason R. Gunn ◽  
Petr Bruza ◽  
Brian Pogue
Keyword(s):  
Protoporphyrin Ix ◽  
Delayed Fluorescence

scholarly journals Imaging of hypoxia, oxygen consumption and recovery in vivo during ALA-photodynamic therapy using delayed fluorescence of Protoporphyrin IX

2020 ◽  
Vol 30 ◽  
pp. 101790 ◽  
Author(s):  
Marek Scholz ◽  
Arthur F. Petusseau ◽  
Jason R. Gunn ◽  
M. Shane Chapman ◽  
Brian W. Pogue
Keyword(s):  
Photodynamic Therapy ◽  
Oxygen Consumption ◽  
Protoporphyrin Ix ◽  
Delayed Fluorescence

Haem oxygenase-1 induction reverses the actions of interleukin-1β on hypoxia-inducible transcription factors and human chondrocyte metabolism in hypoxia

2013 ◽  
Vol 125 (2) ◽  
pp. 99-108 ◽  
Author(s):  
Victoria Clérigues ◽  
Christopher L. Murphy ◽  
Maria Isabel Guillén ◽  
Maria José Alcaraz
Keyword(s):  
Articular Chondrocytes ◽  
Protoporphyrin Ix ◽  
Interleukin 1Β ◽  
Protective Effects ◽  
Protein Levels ◽  
Hypoxic Conditions ◽  
Cobalt Protoporphyrin ◽  
Haem Oxygenase ◽  
Oa Chondrocytes ◽  
Factor Α

HO-1 (haem oxygenase-1) catalyses the degradation of haem and possesses anti-inflammatory and cytoprotective properties. The role of inflammatory mediators in the pathogenesis of OA (osteoarthritis) is becoming increasingly appreciated. In the present study, we investigated the effects of HO-1 induction in OA and healthy HACs (human articular chondrocytes) in response to inflammatory cytokine IL-1 β (interleukin-1β) under hypoxic conditions. Hypoxia was investigated as it is a more physiological condition of the avascular cartilage. Hypoxic signalling is mediated by HIFs (hypoxia-inducible factors), of which there are two main isoforms, HIF-1α and HIF-2α. Normal and OA chondrocytes were stimulated with IL-1β. This cytokine suppresses HO-1 expression and exerts both catabolic and anti-anabolic effects, while increasing HIF-1α and suppressing HIF-2α protein levels in OA chondrocytes in hypoxia. Induction of HO-1 by CoPP (cobalt protoporphyrin IX) reversed these IL-1β actions. The hypoxia-induced anabolic pathway involving HIF-2α, SOX9 [SRY (sex determining region Y)-box 9] and COL2A1 (collagen type II α1) was suppressed by IL-1β, but importantly, levels were restored by HO-1 induction, which down-regulated TNFα (tumour necrosis factor α), MMP (matrix metalloproteinase) activity and MMP-13 protein levels. Depletion of HO-1 using siRNA (small interfering RNA) abolished the CoPP effects, further demonstrating that these were due to HO-1. The results of the present study reveal the different mechanisms by which HO-1 exerts protective effects on chondrocytes in physiological levels of hypoxia.

scholarly journals Role of endogenous carbon monoxide in the control of breathing in zebrafish (Danio rerio)

2016 ◽  
Vol 311 (6) ◽  
pp. R1262-R1270 ◽  
Author(s):  
Velislava Tzaneva ◽  
Steve F. Perry
Keyword(s):  
Carbon Monoxide ◽  
Danio Rerio ◽  
Larval Fish ◽  
Protoporphyrin Ix ◽  
Control Of Breathing ◽  
Zinc Protoporphyrin ◽  
Hypoxic Conditions ◽  
First Time

Carbon monoxide (CO) is a gaseous signaling molecule and is produced in vivo from the intracellular breakdown of heme via the heme oxygenase (HO) family of enzymes. In this study we investigated the role of the HO-1/CO system in the control of ventilation in zebrafish, Danio rerio. Immunohistochemistry revealed the presence of HO-1 in the chemoreceptive neuroepithelial cells (NECs) of larvae (4 days postfertilization) and adults, indicating the potential for endogenous CO production in the NECs. Hypoxia (20 min, water Po2 of 30 mmHg) caused a significant increase in HO-1 activity in whole larvae and in the gills of adult fish. Zebrafish with reduced HO-1 activity (via HO-1 knockdown in larvae or zinc protoporphyrin IX treatment in adults) exhibited increased ventilation frequency ( Vf) under normoxic but not hypoxic conditions. The addition of exogenous CO restored resting Vf in fish with diminished CO production, and in some cases (e.g., hypoxic sham larvae) CO modestly reduced Vf below resting levels. Larval fish were treated with phenylhydrazine (PHZ) to eliminate the potential confounding effects of CO-hemoglobin interactions that might influence ventilation. PHZ treatment did not cause changes in Vf of normoxic larvae, and the addition of CO to PHZ-exposed larvae resulted in a significant decrease in sham and HO-1-deficient fish under normoxic conditions. This study demonstrates for the first time that CO plays an inhibitory role in the control of breathing in larval and adult zebrafish.

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