[Human cultured lens cells. II. Characterization of established lens cell lines and test of their suitability for cytotoxicity tests]

BACKGROUND

Human lens cells in culture may be valuable tools to discover cataractogenic risk factors. Here we report on the characterization of established human lens cells and their use in cytotoxicity tests.

MATERIAL AND METHODS

Adhesion dependence was tested by an autoradiographic method. Soft agar test was performed to secure anchorage-independent growth. Laser scan microscopy was used for measuring the nucleus-cytoplasmic relationship. The cytoskeleton was visualized by fluorescence microscopy. Investigations on cytotoxicity were done by neutral red cytotoxicity assay and 3H-thymidine incorporation. The labeling index was determined by the BrdU-method.

RESULTS

Two lens cell lines were transformed into fast growing cells. They are characterized by a partial loss of adhesion dependence, cell growth in soft agar, high cloning efficiency and reduced serum requirement. However, the nucleus-cytoplasmic relationship did not change very much in comparison to non-transformed lens cells. The organization of the cytoskeleton was cell shape dependent. The intermediate filaments were from the vimentin type. The established cell lines proved to be highly sensitive to ethanol and mitomycin C.

CONCLUSIONS

The established human lens cell lines are well suited to screen for cytotoxic substances in vitro which might be cataractogenic risk factors in vivo.

[Human lens cells in culture. I. Isolation of adult lens epithelial cells from lens capsule preparations and reactivation of nucleus-containing fiber cells]

BACKGROUND

Bovine lens epithelial cells in culture revealed a high sensitivity against micromolar concentrations of linoleic acid. To prove the assumption that unsaturated free fatty acids are risk factors for cataractogenesis, human lens cell lines are needed. Furthermore, the reactivation of nucleus-containing fiber cells to mitotic growth may hint at their role in after cataract genesis.

MATERIAL AND METHODS

Epithelium-capsule-preparations obtained by capsulorhexis were cultured in serum containing medium. Subculturing of these adult human lens epithelial cells was done by trypsinization. Fiber cell bundles from the equator region of a fetal human lens were transferred into culture medium. Aggregates of nucleus containing fiber cells were isolated from floating fiber cell bundles by trypsinization. Subculturing and cryoconservation of suitable cell lines.

RESULTS

Primary culture of epithelium-capsule-preparations results in flattening, migration and proliferation of adult human lens epithelial cells. Nucleus containing fiber cells were reactivated to mitotic growth after adhesion to a suitable substratum. Established cell lines were received from adult human lens epithelial cells and fetal human fiber cells after repeated subculturing.

CONCLUSIONS

Lens-capsule-preparations available from cataract surgery are well suited for the isolation of human lens cell lines, which were needed for testing cytotoxicity of drugs and for tracing of cataractogenic risk factors. The finding that nucleus containing fiber cells from the equator of human lenses can be reactivated to proliferating cells let us suppose, that these cells, which can not be removed easily from the posterior lens capsule, contribute to the after cataract formation.

[Enzymatic studies in lenses of different breeds of mice (author's transl)]

Leucinaminopeptidase (LAP), lactatedehydrogenase (LDH) and glucose-6-phosphatdehydrogenase (GPDH) were analysed in the lenses of two different breeds of mice. Compared to the lenses of a control stock (Agnes Blum, Jena), in the healthy seeming, heterozygous mice the same activities of LAP, LDH, and GPDH were found. But in the breed with evident microphthalmos and cataract LDH was increased. Possible connections are discused.