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Immunofluorescent studies for alpha-actinin in cultured cardiomyopathic hamster heart cells
1Department of Anatomy and Cell Biology, State University of New York, Syracuse 13210.
Insights
Cardiomyopathic (CM) heart cells in culture exhibit abnormal shapes and reduced projections compared to normal cells. This suggests potential cytoskeletal or membrane abnormalities in cardiomyopathic hamsters.
Area of Science:
- Cardiovascular Biology
- Cell Biology
- Genetics
Background:
- Genetic cardiomyopathies (CM) in hamsters are a model for studying heart muscle diseases.
- Understanding cellular morphology in vitro can provide insights into disease mechanisms.
Purpose of the Study:
- To compare the in vitro morphology of cardiac myocytes from normal and cardiomyopathic hamsters.
- To investigate the development of cytoplasmic projections and myofibril organization in these cells.
Main Methods:
- Primary cultures of cardiac myocytes were established from newborn normal and CM hamsters (strain UM X7.1).
- Cells were analyzed using indirect immunofluorescent microscopy over 9 days in culture.
- FITC-labelled anti-alpha-actinin was used to visualize myofibrillar Z bands.
Main Results:
- Normal cardiac myocytes developed cytoplasmic projections and organized myofibrils with parallel arrangements.
- Cardiomyopathic myocytes showed delayed projection formation and significant myofibril disarray.
- The number of projections per cell was markedly reduced in CM myocytes compared to normal cells, especially after 7 and 9 days.
Conclusions:
- Cardiomyopathic cardiac myocytes display distinct abnormal shapes and reduced projection formation in culture.
- These morphological differences suggest underlying abnormalities in the cytoskeletal or membrane systems of CM cells.
- Further research is needed to elucidate the specific factors contributing to these cellular defects.
Abstract:
Primary cultures of cardiac myocytes from normal and genetically cardiomyopathic (CM) newborn hamsters (strain UM X7.1) were analyzed by indirect immunofluorescent microscopy after 3, 5, 7, and 9 days in culture. The cultures were fixed in cold acetone and immunostained by an indirect method using FITC-labelled anti-alpha-actinin to label the myofibrillar Z bands. Most normal and CM myocytes appeared round in shape after 3 days in culture. Normal cardiac myocytes began to exhibit cytoplasmic projections after 5 days in culture and their myofibrils usually showed parallel arrangements with respect to each other. The cardiac cells from CM hearts showed an obvious myofibril disarray. Moreover, projections formed later than normal. As the size of the cells increased, more and more projections formed in normal hamster myocytes during development. By contrast, most of the cardiomyopathic myocytes showed few projections even as late as 9 days in culture. Hence, the number of projections per cell was much less in cardiomyopathic myocytes than in normal, especially after 7 and 9 days in culture. These results suggest that cardiomyopathic cells have abnormal shapes in culture and, in particular, fail to form projections as in normal cells. Whether this unusual behavior is related to an abnormality of the membranes or cytoskeletal system in cardiomyopathic heart cells or to some other factor requires further study.