transforming-growth-factor-beta and Eye-Injuries--Penetrating

The aim of the study was to determine temporal TGFB1, TGFB2 and TGFB3 gene expression profiles in the anterior lens capsule of paediatric patients with posttraumatic cataract. The patient group comprised 22 children selected with a fragment of anterior lens capsule obtained during elective cataract surgery and sampled for molecular analysis. The levels of TGF-β isoforms in the anterior lens capsule were determined based on the number of mRNA copies per 1 μg total RNA by real-time qRTPCR. Three time-related result clusters were identified based on hierarchical cluster analysis: 2.2, 4.4 and 15.0 months (time span from injury to anterior capsule sampling during surgery) and compared with regard to temporal gene expression profile and quantitative relations of TGF-β1, 2 and 3 mRNAs. TGF-β1, TGF-β2, and TGF-β3 mRNAs were detected in all anterior lens capsule samples. A comparative analysis revealed: TGF-β1>TGF-β2>TGF-β3 during the entire observation period. The TGF-β mRNA levels continued to increase up to four months after injury, then returning close to the base levels after around 15 months. The expression patterns of TGF-β isoforms showed a similar tendency. Differences in the expression levels of TGF-β1 and TGF-β2 between the particular clusters were statistically significant. Posttraumatic transcriptional activities of TGF-β1 and TGF-β2 in the anterior lens capsule of paediatric patients depend on the time elapsing from injury. Our findings indicate that the transcriptional activities of TGFB family genes show a transient period of over-expression during the months after injury. TGF-β1 is a dominant isoform expressed in lens epithelial cells following injury.

Topics: Adolescent; Child; Child, Preschool; Epithelial Cells; Eye Injuries, Penetrating; Female; Gene Expression Regulation; Humans; Lens Capsule, Crystalline; Lens, Crystalline; Male; RNA, Messenger; Time Factors; Transforming Growth Factor beta

Previous reports indicated that pregnancy and corneal injury (CI) trigger alterations of lacrimal gland (LG) growth factor expression and redistributions of lymphocytes from periductal foci to acini. The purpose of this study was to test our hypothesis that pregnancy would exacerbate the changes induced by CI.. Corneas were injured with scalpel blades, and, 2 weeks later, LGs were collected for immunocytochemistry and Western blot analysis. Lacrimal fluid was collected under basal- and pilocarpine-stimulated conditions for protein determination and Western blot analyses.. There were significant increases of immunoreactivity for prolactin, TGF-beta1, and EGF in duct cells during pregnancy and after CI, most prominent in pregnant animals with CI. Pregnancy decreased baseline lacrimal fluid secretion, whereas CI did not have a noticeable effect; pregnancy and CI combined resulted in increased fluid production. Pregnancy and CI each increased pilocarpine-induced lacrimal fluid production, whereas protein concentrations were decreased. Prolactin, TGF-beta1, and EGF were detected in LG by Western blot analysis but were minimally detectable in lacrimal fluid. RTLA+ and CD18+ cells were redistributed from periductal to interacinar sites during pregnancy and after CI, most prominent in pregnant animals with CI.. Like pregnancy, CI is associated with redistribution of immune cells from periductal to interacinar sites and enhanced immunoreactivity of prolactin, TGF-beta1, and EGF in ductal cells. Although baseline lacrimal fluid secretion varied, the glands of all three experimental groups produced significant amounts of fluid in response to pilocarpine, but protein concentrations were decreased.

Topics: Animals; Blotting, Western; Cornea; Corneal Injuries; Electrophoresis, Polyacrylamide Gel; Epidermal Growth Factor; Eye Injuries, Penetrating; Female; Immunohistochemistry; Lacrimal Apparatus; Muscarinic Agonists; Pilocarpine; Pregnancy; Pregnancy, Animal; Prolactin; Rabbits; T-Lymphocytes; Transforming Growth Factor beta; Transforming Growth Factor beta1

To examine the role of fibroblast growth factor 2 (FGF2) in regulating lens cell proliferation and epithelial-mesenchymal transition (EMT) in response to injury.. The amount of FGF2 protein was determined in healing, injured rat lenses by enzyme immunoassay. The effects of FGF2 and transforming growth factor beta2 (TGFbeta2) on cell proliferation of alphaTN4 cells (a mouse lens epithelial cell line) were determined. FGF2-knockout mice were used to further examine the role of endogenous FGF2 on injury-induced epithelial cell proliferation and EMT. The anterior lens capsule was injured by a hypodermic needle under both general and topical anesthesia in one eye of 34 fgf2+/+ mice and 42 fgf2-/- mice. At days 2, 5, and 10 post-injury the mice were sacrificed following a 2 h labeling period with bromo-deoxyuridine (BrdU). The number of BrdU-positive cells in each specimen was determined.. A capsular break caused a 10 fold increase of FGF2 protein accumulated in rat lens 14 days after injury. Addition of 3.43 ng/ml FGF2 enhanced proliferation of alphaTN4 cells. This occurred in the presence or absence of exogenous TGFbeta2, that has an inhibitory effect on alphaTN4 cell proliferation. Significantly fewer BrdU-labeled cells were found in fgf2-/- mice than in fgf2+/+ mice during healing post-injury. However, lacking FGF2 did not alter the expression patterns of alpha-smooth muscle actin and collagen type I, markers of EMT in lens cells.. Endogenous FGF2 is required for increased cell proliferation but not essential for EMT during the lens response to injury.

Topics: Actins; Animals; Bromodeoxyuridine; Cell Division; Cell Line, Transformed; Collagen Type I; DNA; Epithelial Cells; Eye Injuries, Penetrating; Fibroblast Growth Factor 2; Immunoenzyme Techniques; Lens Capsule, Crystalline; Lens, Crystalline; Mesoderm; Mice; Mice, Knockout; Rats; Rats, Wistar; Transforming Growth Factor beta; Transforming Growth Factor beta2; Wound Healing

Lens epithelial cells (LECs) undergo epithelial-mesenchcymal transition (EMT) after injury and transform into myofibroblasts positive for alpha-smooth muscle actin (alphaSMA), an established marker of this process. Lumican is a keratan sulfate proteoglycan core protein. This study was conducted to examine whether human and mouse LECs express lumican after injury. To determine whether lumican may modulate EMT of LECs in response to injury or to exposure to transforming growth factor-beta2 (TGFbeta2), alphaSMA expression by the LECs was examined in lumican (Lum)-knockout mice in vivo and in organ culture.. Human postoperative capsular specimens and healing, injured mouse lenses at various intervals were immunostained for lumican or alphaSMA. alphaSMA was also immunolocalized in healing, injured lenses of Lum-knockout mice. Finally, expression of lumican and alphaSMA was examined in lenses of Lum-knockout mice incubated with TGFbeta2.. Lumican was immunolocalized in matrix in human postoperative capsular opacification. Lumican and alphaSMA were upregulated in mouse LECs from 8 hours and day 5 after an injury, respectively. LECs accumulated adjacent to the capsular break were of epithelial shape in Lum(-/-) mice and fibroblast-like in Lum(+/-) mice during healing. alphaSMA expression by LECs was significantly delayed in Lum(-/-) mice, indicating that lumican may modulate injury-induced EMT in LECs. TGFbeta2-induced EMT appeared to be suppressed in organ-cultured lenses of Lum(-/-) mice compared with those of Lum(+/+) mice.. Human capsular opacification contains lumican, and mouse LECs upregulate lumican and alphaSMA in response to injury. Loss of lumican perturbs EMT of mouse LECs.

Topics: Actins; Adult; Aged; Aged, 80 and over; Animals; Cataract; Cataract Extraction; Chondroitin Sulfate Proteoglycans; Collagen Type I; Epithelial Cells; Eye Injuries, Penetrating; Female; Fibroblasts; Humans; Immunoenzyme Techniques; Keratan Sulfate; Lens Capsule, Crystalline; Lumican; Male; Mesoderm; Mice; Mice, Inbred C57BL; Mice, Knockout; Middle Aged; Organ Culture Techniques; Postoperative Complications; Transforming Growth Factor beta; Transforming Growth Factor beta2; Up-Regulation; Wound Healing