Growth regulation of the mammalian ocular lens by vitreous humor

Banerjee, Amit Kumar; Parafina, J; Bagchi, M.

doi:10.1002/jcb.240490112

Cited by 3 publications

(3 citation statements)

References 21 publications

(22 reference statements)

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“…The elucidation of possible structural changes to the ILM in DR as a result of fibrosis, particularly with respect to the ILM pores, would be also of interest. Normal vitreous humor contains angiogenesis inhibitors (Banerjee et al, 1992) that may prevent retinal neovascularization. In DR, an accumulation of collagens and fibronectin in the ILM, a vitreoretinal barrier, may prevent the access of these vitreal factors to the retinal vessels through the ILM pores.…”

Section: Discussionmentioning

confidence: 99%

Basement membrane abnormalities in human eyes with diabetic retinopathy.

Ljubimov¹,

Burgeson²,

Butkowski³

et al. 1996

J Histochem Cytochem.

151

100

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Vascular and parenchymal basement membranes (BMs) are thickened in diabetes, but alterations in individual BM components in diabetic eyes, especially in diabetic retinopathy (DR), are obscure. To identify abnormalities in the distribution of specific constituents, we analyzed cryostat sections of human eyes obtained at autopsy (seven normal, five diabetic without DR, and 13 diabetic with DR) by immunofluorescence with antibodies to 30 BM and extracellular matrix components. In non-DR eyes, no qualitative changes of ocular BM components were seen. In some DR corneas, epithelial BM was stained discontinuously for laminin-1, entactin/nidogen, and alpha3-alpha4 Type IV collagen, in contrast to non-DR corneas. Major BM alterations were found in DR retinas compared to normals and non-DR diabetics. The inner limiting membrane (retinal BM) of DR eyes had accumulations of fibronectin (including cellular) and Types I, III, IV (alpha1-alpha2), and V collagen. The BM zone of new retinal blood vessels in neovascularized areas accumulated tenascin and Type XII collagen, whereas normal, diabetic, and adjacent DR retinas showed only weak and irregular staining. In preretinal membranes, perlecan, bamacan, and Types VI, VIII, XII, and XIV collagen were newly identified. Diabetic BM thickening appears to involve qualitative alterations of specific BM markers at an advanced disease stage, with the appearance of DR.

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Section: Discussionmentioning

confidence: 99%

Basement membrane abnormalities in human eyes with diabetic retinopathy.

Ljubimov¹,

Burgeson²,

Butkowski³

et al. 1996

J Histochem Cytochem.

151

100

View full text Add to dashboard Cite

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“…However, the optical requirements of the lens and constraints imposed by the architectural integrity of the eye require that lens growth be strictly controlled by an as of yet unknown mechanism. Previous reports from several laboratories have indicated that the 6-12 kDa VH proteins participate in many growth control processes [Banerjee et al, 1992;Jacobson et al, 1984;Lisnyak, 1988;Raymond and Jacobson, 19821. We reported that the chromatographic fraction containing the 8 kDa ULP has significant protein synthesis inhibitory activity in the lens.…”

Section: Discussionmentioning

confidence: 98%

“…Significantly, this is the first time that the presence of free ULP has been reported in mammalian extracellular fluids. Furthermore, we recently demonstrated that the 8 kDa fraction of vitreous humor containing ULP is a potent inhibitor of protein synthesis [Banerjee et al (1992): J Cell Biochem 49:66-731. These findings taken together suggest a novel biological role for ULP in the control of lens cell growth.…”

mentioning

confidence: 99%

Identification of a ubiquitin-like protein in the mammalian vitreous humor

et al. 1996

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An 8 kDa ubiquitin-like peptide (ULP) was isolated by high performance liquid chromatography from the rabbit vitreous humor, and the N-terminal amino acid sequence of this peptide showed complete homology with ubiquitin. Western blot revealed the presence of free ULP in both the iris-ciliary (IC) complex and the aqueous humor extracts. In the IC complex, fluorescence and immunoelectron microscopy detected high concentrations of ULP in the posterior epithelial cells, suggesting this tissue as a possible source of ULP in the ocular fluids. Significantly, this is the first time that the presence of free ULP has been reported in mammalian extracellular fluids. Furthermore, we recently demonstrated that the 8 kDa fraction of vitreous humor containing ULP is a potent inhibitor of protein synthesis [Banerjee et al. (1992): J Cell Biochem 49:66-73]. These findings taken together suggest a novel biological role for ULP in the control of lens cell growth.

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The mammalian iris‐ciliary complex affects organization and synthesis of cytoskeletal protein of organ and tissue cultured lens epithelial cells

Banerjee¹,

Emanuel²,

Parafina³

et al. 1992

J of Cellular Biochemistry

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A water soluble growth inhibitor was isolated from the mammalian ocular iris-ciliary complex. The molecular weight of this protein is 10 kD or lower as determined by ultrafiltration fractionation. The iris-ciliary (IC) complex water soluble protein(s) significantly inhibits synthesis of lower molecular weight proteins of the epithelial cells of the organ cultured mammalian ocular lens. It was also found that this inhibitory effect of IC is mediated via the structural organization of the lens. Monolayer cultures of the lens epithelial cells exposed to IC did not manifest any inhibition of their protein synthesis. Moreover, these tissue cultured lens epithelial (TCLE) cells showed a significant increase in their protein synthetic activities in response to the presence of IC factors in the culture medium. It is postulated that the IC activity is modulated via either the lens capsule, an extracellular matrix, or due to the specific organization of the intact lens. The specific effects of IC on the cytoskeletal organization and synthesis in the organ cultured lens epithelial (OCLE) and TCLE cells were also examined. Both groups, treated with IC factors, manifested significant alterations in their protein synthetic activities and cytoskeletal architecture. The 3H-leucine incorporation experiments showed that alpha-actin and alpha-tubulin synthesis is partially inhibited by IC factors in OCLE cells but vimentin synthesis is not, whereas in TCLE cells all of them showed increased synthesis in response to IC factors. Turnover rates of these proteins in both OCLE and TCLE cells were also computed. The immunofluorescence and microscopic evaluation of OCLE and TCLE cells exposed to IC factors illustrated significant alteration in the cytoarchitecture of the filaments. We demonstrate that an inhibitor(s) molecule of 10 kD or lower size isolated from IC inhibited protein synthesis of OCLE cells and stimulated protein synthesis in TCLE cells. The IC factor also affects the synthesis and organization of cytoskeletal filaments of both the OCLE and TCLE cells.

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Growth regulation of the mammalian ocular lens by vitreous humor

Cited by 3 publications

References 21 publications

Basement membrane abnormalities in human eyes with diabetic retinopathy.

Basement membrane abnormalities in human eyes with diabetic retinopathy.

Identification of a ubiquitin-like protein in the mammalian vitreous humor

The mammalian iris‐ciliary complex affects organization and synthesis of cytoskeletal protein of organ and tissue cultured lens epithelial cells

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