Expression of protein kinase C isoforms and interleukin-1beta in myofibrillar myopathy.
BACKGROUND
The term myofibrillar myopathy refers to a rare and clinically heterogeneous group of muscle disorders. The pathogenesis of this myopathy is not well understood. The morphologic hallmark is myofibrillar destruction with abnormal expression of numerous proteins, most consistently of desmin.


METHODS
The authors investigated eight patients with myofibrillar myopathy belonging to four families. They studied the role of different protein kinase C isoforms and of interleukin-1beta, a cytokine that might activate protein kinase C and, in addition, mediate myofibrillar proteolysis.


RESULTS
Immunohistochemical analysis showed the expression of alpha, eta, and zeta isoforms of protein kinase C and of interleukin-1beta in abnormal muscle fibers. Immunoblots confirmed the immunohistochemical data and revealed the absence of protein kinase C delta and epsilon in muscle fibers from patients and controls.


CONCLUSIONS
These data suggest that protein kinase C and interleukin-1beta may play a role in the pathogenesis of myofibrillar myopathy.
Vattemi
G
G
Department of Neurological Sciences and Vision, Section of Clinical Neurology, Clinica Neurologica, Policlinico G.B. Rossi, Verona, Italy.
Tonin
P
P
Mora
M
M
Filosto
M
M
Morandi
L
L
Savio
C
C
Dal Pra
I
I
Rizzuto
N
N
Tomelleri
G
G
D000251:Adenosine Triphosphatases / Q000172:deficiency; D000328:Adult; D003893:Desmin / Q000378:metabolism; D005260:Female; D006801:Humans; D007375:Interleukin-1 / Q000032:analysis*; D007527:Isoenzymes / Q000032:analysis / Q000172:deficiency; D008297:Male; D008875:Middle Aged; D018908:Muscle Weakness / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D018482:Muscle, Skeletal / Q000737:chemistry / Q000648:ultrastructure; D009135:Muscular Diseases / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D009210:Myofibrils / Q000473:pathology; D018384:Oxidative Stress; D010766:Phosphorylation; D011493:Protein Kinase C / Q000032:analysis* / Q000172:deficiency; D011499:Protein Processing, Post-Translational; D012131:Respiratory Insufficiency / Q000235:genetics / Q000378:metabolism / Q000473:pathology
D003893:Desmin; D007375:Interleukin-1; D007527:Isoenzymes; D011493:Protein Kinase C; D000251:Adenosine Triphosphatases