Related Experiment Videos
Whole microvascular unit deletions in dermatomyositis
Cyril Gitiaux1, Enis Kostallari, Peggy Lafuste
1Neuropediatry Unit, AP-HP, Necker - Enfants Malades, Hospital, Paris, France.
Annals of the Rheumatic Diseases
|September 11, 2012
Summary
Dermatomyositis muscle damage may stem from upstream arterial issues, not primary capillary loss. This suggests ischemia-reperfusion injury, activated by complement, could be a key, potentially preventable, mechanism.
Area of Science:
- Muscle pathophysiology
- Immunopathology
- Microvascular research
Background:
- The exact cause of dermatomyositis (DM) muscle damage is unknown, with theories involving immune attacks and ischemia from capillary destruction.
- The role of microvascular changes in DM pathophysiology requires further clarification.
Purpose of the Study:
- To reappraise microvascular involvement in DM by comparing it to normal muscle microvascular organization.
- To investigate the potential role of ischemia-reperfusion injury in DM.
Main Methods:
- 3D reconstructions of CD31-stained muscle sections and alkaline phosphatase activity were used to analyze microvasculature.
- Point pattern analysis assessed capillary loss, and double immunostaining identified cell types with membranolytic attack complex (MAC) deposits.
Main Results:
- Normal muscle vasculature involves arcade arteries, transverse arteries, and terminal arterioles supplying capillary units.
- DM cases showed patchy capillary loss (MVU depletion) and clustered MAC deposits on various cell types, including endothelial and perivascular cells.
Conclusions:
- Capillary loss may be secondary to upstream events, possibly involving perimysial arcade arteries, rather than the primary cause of ischemia in DM.
- Ischemia-reperfusion injury, potentially triggered by complement activation, is proposed as a significant and possibly preventable mechanism of muscle damage in DM.