| 1. |
- N'Guessan, PD., et al.
(author)
-
The UspA1 protein of Moraxella catarrhalis induces CEACAM-1-dependent apoptosis in alveolar epithelial cells.
- 2007
-
In: Journal of Infectious Diseases. - : Oxford University Press (OUP). - 1537-6613 .- 0022-1899. ; 195:11, s. 1651-1660
-
Journal article (peer-reviewed)abstract
- Moraxella catarrhalis is a major cause of exacerbations of chronic obstructive pulmonary disease (COPD) and emphysema. M. catarrhalis–specific UspA1 and the epithelial carcinoembryonic antigen-related cell adhesion molecule (CEACAM1) were required to induce apoptosis. M. catarrhalis–induced apoptosis was significantly enhanced in HeLa cells stably transfected with CEACAM1, compared with HeLa cells not expressing CEACAM1. Infected cells showed increased activity of caspases 3, 6, and 9 but not of caspase 8. Reduced expression of Bcl-2, translocation of Bax into the mitochondria, and cytosolic increase of apoptosis-inducing factor in M. catarrhalis–infected cells implicated the involvement of mitochondrial death pathways. In conclusion, M. catarrhalis induced apoptosis in pulmonary epithelial cells—a process that was triggered by interaction between CEACAM1 and UspA1. Thus, M. catarrhalis–induced apoptosis of pulmonary epithelial cells may contribute to the development of COPD and emphysema.
|
|
| 2. |
- Ponsot, Elodie, 1973-, et al.
(author)
-
Mitochondrial tissue specificity of substrates utilization in rat cardiac and skeletal muscles
- 2005
-
In: Journal of Cellular Physiology. - Hoboken, USA : John Wiley & Sons. - 0021-9541 .- 1097-4652. ; 203:3, s. 479-86
-
Journal article (peer-reviewed)abstract
- As energetic metabolism is crucial for muscles, they develop different adaptations to respond to fluctuating demand among muscle types. Whereas quantitative characteristics are known, no study described simultaneously quantitative and qualitative differences among muscle types in terms of substrates utilization patterns. This study thus defined the pattern of substrates preferential utilization by mitochondria from glycolytic gastrocnemius (GAS) and oxidative soleus (SOL) skeletal muscles and from heart left ventrical (LV) in rats. We measured in situ, ADP (2 mM)-stimulated, mitochondrial respiration rates from skinned fibers in presence of increasing concentrations of pyruvate (Pyr) + malate (Mal), palmitoyl-carnitine (Palm-C) + Mal, glutamate (Glut) + Mal, glycerol-3-phosphate (G3-P), lactate (Lact) + Mal. Because the fibers oxygen uptake (Vs) followed Michaelis-Menten kinetics in function of substrates level we determined the Vs and Km, representing maximal oxidative capacity and the mitochondrial sensibility for each substrate, respectively. Vs were in the order GAS < SOL < LV for Pyr, Glu, and Palm-C substrates, whereas in the order SOL = LV < GAS with G3-P. Moreover, the relative capacity to oxidize Palm-C is extremely higher in LV than in SOL. Vs was not stimulated by the Lact substrate. The Km was equal for Pyr among muscles, but much lower for G3-P in GAS and lower for Palm-C in LV. These results demonstrate qualitative mitochondrial tissue specificity for metabolic pathways. Mitochondria of glycolytic muscle fibers are well adapted to play a central role for maintaining a satisfactory cytosolic redox state in these fibers, whereas mitochondria of LV developed important capacities to use fatty acids.
|
|
