scholarly journals Evaluation of a novel combination of TRAM-34 and ascorbic acid for the treatment of corneal fibrosis in vivo

PLoS ONE ◽  
2022 ◽  
Vol 17 (1) ◽  
pp. e0262046
Author(s):  
Allison A. Fuchs ◽  
Praveen K. Balne ◽  
Elizabeth A. Giuliano ◽  
Nishant R. Sinha ◽  
Rajiv R. Mohan
Keyword(s):  
Ascorbic Acid ◽  
Transforming Growth Factor Beta ◽  
Vision Loss ◽  
Transforming Growth Factor ◽  
Corneal Thickness ◽  
Rabbit Model ◽  
Study Endpoint ◽  
Corneal Injury ◽  
Collagen Iii

Corneal injury and aberrant wound healing commonly result in corneal fibrosis and subsequent vision loss. Intermediate-conductance calmodulin/calcium-activated K+ channels (KCa3.1) have been shown to promote fibrosis in non-ocular and ocular tissues via upregulation of transforming growth factor beta (TGFβ). TRAM-34 is a selective inhibitor of KCa3.1 and reduces fibrosis by downregulation of TGFβ-induced transdifferentiation of stromal fibroblasts to myofibroblasts. Ascorbic acid has been demonstrated to be effective in promoting corneal re-epithelialization and reduction of neovascularization via anti-VEGF and anti-MMP mechanisms. This study evaluates tolerability and efficacy of a novel combination of TRAM-34 (25μM) and ascorbic acid (10%) topical treatment for corneal fibrosis using an established in vivo rabbit model and conducting clinical eye examinations. Markers of corneal fibrosis were evaluated in all corneas at study endpoint via histopathology, immunofluorescence, and quantitative real-time PCR. The eyedrop treated eyes showed significantly improved clinical outcomes based on modified McDonald Shadduck scores, reduction of clinical haze on Fantes scores, and reduction of central corneal thickness (CCT). At cellular and molecular levels, eyedrop treatment also significantly reduced expression of alpha smooth muscle actin (α-SMA) mRNA and protein, collagen III mRNA, and fibronectin mRNA compared to non-treated eyes. Our study suggests that a tested new bimodal eyedrop is well tolerated and effectively reduces corneal fibrosis/haze in rabbits in vivo.

scholarly journals Effect of valproic acid on functional bleb morphology in a rabbit model of minimally invasive surgery

2021 ◽  
pp. bjophthalmol-2020-318691
Author(s):  
Zhu Li Yap ◽  
Li-Fong Seet ◽  
Stephanie WL Chu ◽  
Li Zhen Toh ◽  
Farah Ilyana Ibrahim ◽  
...  
Keyword(s):  
Valproic Acid ◽  
Cell Growth ◽  
Minimally Invasive ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Rabbit Model ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Label Free ◽  
Collagen Fibres

AbstractPurposeTo determine the effect of valproic acid (VPA) on bleb morphology and scar characteristics in a rabbit model of minimally invasive glaucoma surgery (MIGS).MethodsNine New Zealand white rabbits were subjected to MIGS with intraoperative implantation of the PreserFlo MicroShunt. Rabbits were then administered with subconjunctival injections of phosphate buffered saline (PBS) (n=4) or with VPA (n=5). Bleb morphology was examined by slit-lamp biomicroscopy and in vivo confocal microscopy. Postoperative day 28 tissues were examined by immunohistochemical evaluation and label-free multiphoton microscopy to visualise the collagen matrix, by terminal deoxynucleotidyl transferase dUTP nick-end labelling assay and immunofluorescent labelling for Ki67 expression to detect apoptosis and cell growth, and by real-time quantitative PCR to measure Col1a1, Fn, and Smad6 transcript expression.ResultsVPA-treated blebs were detectable on day 28, while the PBS-treated blebs were not detectable by day 14. VPA-treated blebs were diffuse, extended posteriorly with near normal conjunctival vascularity and featured a combination of reticular/blurred stromal pattern with evidence of relatively large stromal cysts. Instead of the deposition of thick, disorganised collagen fibres characteristic of the PBS bleb, the VPA bleb contained conspicuously thinner collagen fibres which were associated with similarly thinner fibronectin fibres. In corroboration, Col1a1 and Fn mRNA expression was reduced in the VPA blebs, while increased Smad6 expression implicated the disruption of the transforming growth factor beta pathway. Apoptosis and cell growth profiles appeared similar with both treatments.ConclusionsThe results support the application of VPA to enhance bleb morphology associated with good bleb function in MIGS with no apparent cytotoxicity.

scholarly journals EFFECT OF CRUDE EXTRACT AND PHYTOSTEROL FRACTION OF FUMARIA OFFICINALIS IN INDUCED HYPERTROPHIC SCAR OF RABBITS

2019 ◽  
pp. 484-491
Author(s):  
HANAN S NOORI ◽  
AHMED ABU‑RAGHIF
Keyword(s):  
Transforming Growth Factor Beta ◽  
Crude Extract ◽  
Hypertrophic Scar ◽  
Transforming Growth Factor ◽  
Ventral Surface ◽  
Included Study ◽  
Treatment Groups ◽  
Collagen Iii ◽  
Fumaria Officinalis

Objective: The present study aimed to evaluate the role of crude extract and phytosterol fraction of Fumaria officinalis in experimentally induced hypertrophic scar in rabbits. Methods: Surgical wounds were performed on day 1 with an 8‑mm biopsy punch four wounds were created on the ventral surface of the rabbit ear (in vivo) down to cartilage. Triamcinolone acetonide (TAC), crude and phytosterol extracts of F. officinalis L. are administered topically to established scars on day 31. The outcome measures included study of histopathology of skin sections, transforming growth factor beta‑1 (TGF‑β1), level, and collagen three alpha1 in skin tissue. Results: In comparison with the induced hypertrophic scar, all treatment produced a significant reduction in scores of TGFβ1, collagen III, inflammation, and measurement of SEI (p ≤ 0.01). The most significant reduction in inflammation and thickness observed in TAC and extract of crude F. officinalis L. Only crude F. officinalis L. decrease fibroblast counts in comparison to induced hypertrophic scar group and other group (p ≤ 0.05). No statistically significant differences were found between the treatment groups in terms of TGF β1and collagen III. Conclusion: Topical crude extract of F. officinalis L. was more effective in the treatment of induced hypertrophic scar as compared with phytosterol of F. officinalis L. and comparable to the effectiveness of topical TAC.

Neutralisation of TGF-beta 1 and TGF-beta 2 or exogenous addition of TGF-beta 3 to cutaneous rat wounds reduces scarring

1995 ◽  
Vol 108 (3) ◽  
pp. 985-1002 ◽  
Author(s):  
M. Shah ◽  
D.M. Foreman ◽  
M.W. Ferguson
Keyword(s):  
Wound Healing ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Collagen I ◽  
Tgf Beta ◽  
Early Stages ◽  
Collagen Iii ◽  
Exogenous Addition ◽  
Growth Factor Beta ◽  
Beta 2

Exogenous addition of neutralising antibody to transforming growth factor-beta 1,2 to cutaneous wounds in adult rodents reduces scarring. Three isoforms of transforming growth factor-beta (1, 2 and 3) have been identified in mammals. We investigated the isoform/isoforms of TGF-beta responsible for cutaneous scarring by: (i) reducing specific endogenous TGF-beta isoforms by exogenous injection of isoform specific neutralising antibodies; and (ii) increasing the level of specific TGF-beta isoforms by exogenous infiltration into the wound margins. Exogenous addition of neutralising antibody to TGF-beta 1 plus neutralising antibody to TGF-beta 2 reduced the monocyte and macrophage profile, neovascularisation, fibronectin, collagen III and collagen I deposition in the early stages of wound healing compared to control wounds. Treatment with neutralising antibodies to TGF-betas 1 and 2 markedly improved the architecture of the neodermis to resemble that of normal dermis and reduced scarring while the control wounds healed with scar formation. Exogenous addition of neutralising antibody to TGF-beta 1 alone also reduced the monocyte and macrophage profile, fibronectin, collagen III and collagen I deposition compared to control wounds. However, treatment with neutralising antibody to TGF-beta 1 alone only marginally reduced scarring. By contrast, wounds treated with neutralising antibody to TGF-beta 2 alone did not differ from control wounds. Interestingly, exogenous addition of the TGF-beta 3 peptide also reduced the monocyte and macrophage profile, fibronectin, collagen I and collagen III deposition in the early stages of wound healing and markedly improved the architecture of the neodermis and reduced scarring. By contrast, wounds treated with either TGF-beta 1 or with TGF-beta 2 had more extracellular matrix deposition in the early stages of wound healing but did not differ from control wounds in the final quality of scarring. This study clearly demonstrates isoform specific differences in the role of TGF-betas in wound healing and cutaneous scarring. TGF-beta 1 and TGF-beta 2 are implicated in cutaneous scarring. This study also suggests a novel therapeutic use of exogenous recombinant, TGF-beta 3 as an anti-scarring agent.

In vitro modulation of endothelial fenestrae: opposing effects of retinoic acid and transforming growth factor beta

1988 ◽  
Vol 91 (2) ◽  
pp. 313-318
Author(s):  
T. Lombardi ◽  
R. Montesano ◽  
M.B. Furie ◽  
S.C. Silverstein ◽  
L. Orci
Keyword(s):  
Endothelial Cells ◽  
Retinoic Acid ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Surface Density ◽  
Transforming Growth Factor ◽  
Control Cell ◽  
Tgf Beta ◽  
Growth Factor Beta

Cultured endothelial cells isolated from fenestrated capillaries express many properties characteristic of their in vivo differentiated phenotype, including the formation of a limited number of fenestrae. In this study, we have investigated whether physiological factors that control cell differentiation might regulate the surface density of fenestrae in capillary endothelial cells. We have found that treatment of the cultures with retinoic acid (10 microM) induces a more than threefold increase in the surface density of endothelial fenestrae, whereas transforming growth factor beta (TGF beta) (2 ng ml-1) causes a sevenfold decrease in the surface density of these structures. These results show that the expression of endothelial fenestrae is susceptible to bidirectional modulation by physiological signals, and suggest that retinoids and TGF beta may participate in the regulation of fenestral density of capillary endothelium in vivo.

scholarly journals Transforming growth factor beta 1 (TGF-beta 1) induced neutrophil recruitment to synovial tissues: implications for TGF-beta-driven synovial inflammation and hyperplasia.

1991 ◽  
Vol 173 (5) ◽  
pp. 1121-1132 ◽  
Author(s):  
R A Fava ◽  
N J Olsen ◽  
A E Postlethwaite ◽  
K N Broadley ◽  
J M Davidson ◽  
...  
Keyword(s):  
Growth Factor ◽  
Synovial Tissue ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Biologically Active ◽  
Tgf Beta ◽  
Histological Techniques ◽  
Growth Factor Beta

We have studied the consequences of introducing human recombinant transforming growth factor beta 1 (hrTGF-beta 1) into synovial tissue of the rat, to begin to better understand the significance of the fact that biologically active TGF-beta is found in human arthritic synovial effusions. Within 4-6 h after the intra-articular injection of 1 microgram of hrTGF-beta 1 into rat knee joints, extensive recruitment of polymorphonuclear leukocytes (PMNs) was observed. Cytochemistry and high resolution histological techniques were used to quantitate the influx of PMNs, which peaked 6 h post-injection. In a Boyden chamber assay, hrTGF-beta 1 at 1-10 fg/ml elicited a chemotactic response from PMNs greater in magnitude than that evoked by FMLP, establishing that TGF-beta 1 is an effective chemotactic agent for PMNs in vitro as well as in vivo. That PMNs may represent an important source of TGF-beta in inflammatory infiltrates was strongly suggested by a demonstration that stored TGF-beta 1 was secreted during phorbol myristate acetate-stimulated degranulation in vitro. Acid/ethanol extracts of human PMNs assayed by ELISA contained an average of 355 ng of TGF/beta 1 per 10(9) cells potentially available for secretion during degranulation of PMNs. [3H]Thymidine incorporation in vivo and autoradiography of tissue sections revealed that widespread cell proliferation was triggered by TGF-beta 1 injection. Synovial lining cells and cells located deep within the subsynovial connective tissue were identified as sources of at least some of the new cells that contribute to TGF-beta 1-induced hyperplasia. Our results demonstrate that TGF-beta is capable of exerting pathogenic effects on synovial tissue and that PMNs may represent a significant source of the TGF-beta present in synovial effusions.

scholarly journals An In Vitro Model for Assessing Corneal Keratocyte Spreading and Migration on Aligned Fibrillar Collagen

2018 ◽  
Vol 9 (4) ◽  
pp. 54 ◽  
Author(s):  
Pouriska Kivanany ◽  
Kyle Grose ◽  
Nihan Yonet-Tanyeri ◽  
Sujal Manohar ◽  
Yukta Sunkara ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Cell Movement ◽  
Time Lapse ◽  
Collagen Fibrils ◽  
Fibrillar Collagen ◽  
Freeze Injury

Background: Corneal stromal cells (keratocytes) are responsible for developing and maintaining normal corneal structure and transparency, and for repairing the tissue after injury. Corneal keratocytes reside between highly aligned collagen lamellae in vivo. In addition to growth factors and other soluble biochemical factors, feedback from the extracellular matrix (ECM) itself has been shown to modulate corneal keratocyte behavior. Methods: In this study, we fabricate aligned collagen substrates using a microfluidics approach and assess their impact on corneal keratocyte morphology, cytoskeletal organization, and patterning after stimulation with platelet derived growth factor (PDGF) or transforming growth factor beta 1 (TGFβ). We also use time-lapse imaging to visualize the dynamic interactions between cells and fibrillar collagen during wound repopulation following an in vitro freeze injury. Results: Significant co-alignment between keratocytes and aligned collagen fibrils was detected, and the degree of cell/ECM co-alignment further increased in the presence of PDGF or TGFβ. Freeze injury produced an area of cell death without disrupting the collagen. High magnification, time-lapse differential interference contrast (DIC) imaging allowed cell movement and subcellular interactions with the underlying collagen fibrils to be directly visualized. Conclusions: With continued development, this experimental model could be an important tool for accessing how the integration of multiple biophysical and biochemical signals regulate corneal keratocyte differentiation.

scholarly journals Effect of Acute Increases in Intraocular Pressure on Corneal Pachymetry in Rabbit Eyes Treated with Timolol Maleate

2018 ◽  
Vol 12 (1) ◽  
pp. 314-321
Author(s):  
Cristina Sánchez-Barahona ◽  
Gema Bolívar ◽  
Dimitrios G. Mikropoulos ◽  
Anastasios G. Konstas ◽  
Miguel A. Teus
Keyword(s):  
Intraocular Pressure ◽  
Anterior Chamber ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Rabbit Model ◽  
Controlled Study ◽  
Control Group ◽  
Study Group ◽  
Timolol Maleate

Objective: To evaluate in an in vivo rabbit model, the effect of topical timolol maleate therapy on the central corneal thickness response to acute intraocular pressure increases. Method: In this prospective and interventional controlled study, the central corneal thickness and intraocular pressure were measured in vivo in 12 rabbit eyes treated with topical timolol maleate for 1 month and in 12 controls at baseline, and after the intraocular pressure (measured by direct cannulation of the anterior chamber) was increased to 15 and 30 mmHg using a forced saline infusion into the anterior chamber. Results: There were no significant differences in the basal central corneal thickness values (control group, 373.2±12.9 µm; study group, 377.5±19.2 µm, p=0.5) or the central corneal thickness values when the intraocular pressure was increased to 15 mmHg (control group, 335.2±14.3 µm; study group, 330.0±32.1 µm, p=0.6) and to 30 mmHg (study group, 318.8±25.3 µm; control group, 329.8±21.0 µm, p=0.3). Conclusion: Rabbit corneas treated with topical timolol maleate for 1 month did not show a strain response to acute intraocular pressure increases that differed from control eyes. This is in contrast to a previous finding in which rabbit eyes treated with prostaglandin analogues had a greater decrease in central corneal thickness in response to a sudden intraocular pressure increase compared with untreated corneas.

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