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CD40-CD40 ligand disruption does not prevent hyperoxia-induced injury
Constance Barazzone Argiroffo1, Yves R Donati, Julien Boccard
1Department of Pediatrics, University of Geneva Medical School, Geneva, Switzerland. constance.barrazone@medecine.unige.ch
Abstract:
Recent studies suggest that apoptosis plays a role in oxygen-induced injury, although the activation pathways and the executioner proteases that lead to cleavage of lung cell proteins and DNA, are not yet identified. We explored previously the tumor necrosis factor/tumor necrosis factor receptor and the Fas/FasL, belonging to the intrinsic pathway, and could not demonstrate any protective effect by interfering with these cell receptors. Lately, it has been shown that interacting with the CD40 system, also known to promote cell death, by administering anti-CD40 ligand (L) antibody was beneficial in several diseases and, in particular, in hyperoxia-induced injury. Using CD40- and CD40L-deficient mice (-/-) as well as administering anti-CD40L antibody, we examined the extent of lung injury in oxygen-breathing mice by several ways (lung weight, histology, inflammatory mediators, and DNA ladder) as well as the mortality. The development of lung injury was similar in wild-type, CD40-/-, CD40L-/-, or in wild-type mice treated with anti-CD40L antibody. Apoptosis was present in all conditions at 72 hours of oxygen exposure. These results show that oxygen-induced injury does not require CD40-CD40L interaction and that apoptosis of lung cells does not involve this pathway.
Insights
Oxygen-induced lung injury does not rely on the CD40-CD40L pathway. Apoptosis, or programmed cell death, in lung cells during hyperoxia exposure occurs independently of this interaction.
Area of Science:
- Pulmonology
- Cell Biology
- Immunology
Background:
- Apoptosis (programmed cell death) is implicated in oxygen-induced lung injury.
- Previous research explored tumor necrosis factor and Fas/FasL pathways without identifying protective effects.
- The CD40 system, known to promote cell death, has shown potential benefits in hyperoxia-induced injury models.
Purpose of the Study:
- To investigate the role of the CD40-CD40L interaction in oxygen-induced lung injury.
- To determine if CD40-CD40L signaling is essential for apoptosis in lung cells during hyperoxia.
Main Methods:
- Utilized CD40- and CD40L-deficient mice.
- Administered anti-CD40L antibody to wild-type mice.
- Assessed lung injury via lung weight, histology, inflammatory mediators, DNA laddering, and mortality in mice exposed to oxygen.
Main Results:
- Lung injury development was comparable across wild-type, CD40-/-, CD40L-/- mice, and wild-type mice treated with anti-CD40L antibody.
- Apoptosis was observed in all experimental groups after 72 hours of oxygen exposure.
- No significant difference in mortality was noted between the groups.
Conclusions:
- Oxygen-induced lung injury does not necessitate CD40-CD40L interaction.
- The CD40-CD40L pathway is not involved in the apoptosis of lung cells during hyperoxia.