scholarly journals Changes of matrix metalloproteinases in the stroma after corneal cross-linking in rabbits

2021 ◽  
Vol 14 (1) ◽  
pp. 26-31
Author(s):  
Hong-Zhen Jia ◽  
◽  
Xiu-Jun Peng ◽  

AIM: To observe changes in the content of matrix metalloproteinases (MMPs) in the corneal stroma after corneal cross-linking (CXL) in rabbits, and further explore the corneal pathophysiological process after CXL. METHODS: Forty-two rabbits (42 eyes) were randomly divided into seven groups. One group served as the control group, while the other six groups were treated with CXL. The concentrations of MMPs in corneal stroma were evaluated through parallel reaction monitoring at baseline and 3, 7, 15, 30, 90, and 180d after treatment. RESULTS: The levels of MMP-2 in the corneal stroma of rabbits were 0.76±0.07, 2.78±1.39, 4.12±0.69, 2.00±0.29, 2.00±0.30, 1.22±0.18, and 1.35±0.18 (10-9 mol/g) at baseline and 3, 7, 15, 30, 90, and 180d after treatment, respectively. The contents of tissue inhibitor of metalloproteinase-1 (TIMP-1) were 1.83±0.26, 7.94±0.58, 6.95±2.64, 3.81±0.48, 3.07±0.92, 1.72±0.19, and 1.69±0.74 (10-9 mol/g), respectively. The ratios of MMP-2/TIMP-1 were 0.42±0.33, 0.36±0.20, 0.62±0.10, 0.54±0.15, 0.68±0.13, 0.71±0.10, and 0.68±0.09, respectively. After CXL, the expression of MMP-2 and TIMP-1 in the rabbit corneal stroma was initially increased and subsequently decreased. The levels of MMP-2 remained higher than those recorded at baseline 180d after treatment, but it was not statistically significant. The levels of TIMP-1 returned to baseline levels at 90d after treatment. The ratio of MMP-2/TIMP-1 started to rise from 7d after CXL. It was significantly higher than that calculated at baseline 30-180d after CXL. The results for MMP-1, -3, -7, -9, -13, and TIMP-2 were negative. CONCLUSION: CXL can lead to changes in the content of MMP-2 and TIMP-1 in the rabbit corneal stroma. The ratio of MMP-2/TIMP-1 remains higher versus baseline, indicating that MMP-2 is involved in the corneal pathophysiological process after CXL.

2013 ◽  
pp. 519-526 ◽  
Author(s):  
M. KNAŚ ◽  
M. NICZYPORUK ◽  
A. ZALEWSKA ◽  
H. CAR

Diabetes mellitus types 1 and 2 are chronic diseases that cause serious health complications, including dermatologic problems. The diabetic skin is characterized by disturbances in collagen metabolism. A tissue remodeling depends on the degradation of extracellular matrix through the matrix metalloproteinases, which are regulated by e.g. the tissue inhibitors of metalloproteinases. The balance between matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) is essential to maintain homeostasis in the skin. The aim of this study was to determine the concentration of metalloproteinase 2, tissue inhibitor of metalloproteinase 3 and the concentration of collagen type 1 in unwounded skin of diabetes type 1 and 2 and healthy controls. The treatment of diabetes resulted in a significant decrease of MMP2, increase of TIMP3 and COL1 concentrations in the skin as compared to the untreated diabetic skin. The concentrations of MMP2 in the skin of treated rats did not show significant differences from the healthy control group. TIMP3 concentrations in the skin of treated rats are not returned to the level observed in the control group. Disturbances of the extracellular matrix of the skin are similar in diabetes type 1 and 2. Application of insulin in diabetes therapy more preferably affects the extracellular matrix homeostasis of the skin.


2020 ◽  
Vol 1 (1) ◽  
pp. 1-6
Author(s):  
Jing Qiao

AIM: To evaluate the effects of genipin cross-linking on bullous keratopathy in rabbits. METHODS: Nine female New Zealand white rabbits with bullous keratopathy were used as an experimental model. They were randomized into three groups. Corneas in Group A (treatment group, n=3) were immersed in 0.25% genipin at 24℃ for 40min; those in Group B (control group, n=3) were immersed in 0.9% sodium chloride solution at 24℃ for 40min; and those in Group C (blank control group, n=3) received no treatment. Follow-up examinations were performed within 2wk after treatment, including slit-lamp microscopy, central corneal thickness (CCT), evaluations of body weight and stress responses, histopathological analyses, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) for detecting stromal cell apoptosis. RESULTS: Compared to Groups B and C, remission of corneal edema, corneal healing, disappearance of epithelial bullae, a significant decrease in CCT (P<0.05), and a significant increase in body weight (P<0.05) were found in Group A. Animals in Group A became more active and showed less aggression and violent resistance behavior. More regular and dense arrangement of collagen fibers in the corneal stroma and formation of blue strips of cross-linking products were observed in Group A. Cell apoptosis occasionally occurred in the corneal stroma of Group A, while no cell apoptosis was observed in Groups B and C. CONCLUSION: Genipin cross-linking treatment for bullous keratopathy in rabbits results in remission of corneal edema and relief of pain. We hypothesize that genipin cross-linking strengthens collagen fibers in corneal stroma to avoid the formation of corneal edema and bullae.


2014 ◽  
Vol 39 (2) ◽  
pp. 152-158 ◽  
Author(s):  
DLS Scheffel ◽  
J Hebling ◽  
RH Scheffel ◽  
K Agee ◽  
G Turco ◽  
...  

SUMMARY Objectives Published transmission electron microscopy analysis of in vitro resin-dentin bonds shows that, after 44 months, almost 70% of collagen fibrils from the hybrid layer disappear. Matrix metalloproteinases (MMPs) play an important role in that process and are thought to be the main factor responsible for the solubilization of dentin collagen. Therefore, this study aimed to evaluate the inactivation of matrix-bound MMPs by two different cross-linking agents, carbodiimide (EDC) or proanthocyanidin (PA), or the MMP-inhibitor, chlorhexidine (CHX), on acid-etched dentin using a simplified MMP assay method. Materials and Methods Dentin beams (2×1×6 mm) were obtained from mid-coronal dentin of sound third molars and randomly divided into six groups (G) according to the dentin treatment: G1: Deionized water (control); G2: 0.1 M EDC; G3: 0.5 M EDC; G4: 0.5 M EDC + 35% hydroxyethyl methacrylate (HEMA); G5: 5% PA; and G6: 2% CHX. The beams were etched for 15 seconds with 37% phosphoric acid, rinsed, and then immersed for 60 seconds in one of the treatment solutions. The data were expressed both in absorbance values at 412 nm and in MMP-9 activity equivalents. The total MMP activity of dentin was analyzed for one hour by colorimetric assay (Sensolyte). Data were submitted to Wilcoxon nonparametric test and Mann-Whitney tests (p&gt;0.05). Results All experimental cross-linking solutions significantly reduced MMP activity from 79.8% to 95.2% when compared to the control group. No difference was observed among 0.1 M EDC (84.8%), 5% PA (87.6%), and 2% CHX (79.8%). Addition of 35% HEMA to 0.5 M EDC produced inactivation (95.2%) that was similar to that of 0.5 M EDC alone (92.7%). Conclusion Dentin treatment with cross-linking agents is effective to significantly reduce MMP activity. Mixing 0.5 M EDC and 35% HEMA did not influence EDC inhibitor potential.


2020 ◽  
pp. 155335062097800
Author(s):  
Ian A. Makey ◽  
Nitin A. Das ◽  
Samuel Jacob ◽  
Magdy M. El-Sayed Ahmed ◽  
Colleen M. Makey ◽  
...  

Background. Retained hemothorax (RH) is a common problem in cardiothoracic and trauma surgery. We aimed to determine the optimum agitation technique to enhance thrombus dissolution and drainage and to apply the technique to a porcine-retained hemothorax. Methods. Three agitation techniques were tested: flush irrigation, ultrasound, and vibration. We used the techniques in a benchtop model with tissue plasminogen activator (tPA) and pig hemothorax with tPA. We used the most promising technique vibration in a pig hemothorax without tPA. Statistics. We used 2-sample t tests for each comparison and Cohen d tests to calculate effect size (ES). Results. In the benchtop model, mean drainages in the agitation group and control group and the ES were flush irrigation, 42%, 28%, and 2.91 ( P = .10); ultrasound, 35%, 27%, and .76 ( P = .30); and vibration, 28%, 19%, and 1.14 ( P = .04). In the pig hemothorax with tPA, mean drainages and the ES of each agitation technique compared with control (58%) were flush irrigation, 80% and 1.14 ( P = .37); ultrasound, 80% and 2.11 ( P = .17); and vibration, 95% and 3.98 ( P = .06). In the pig hemothorax model without tPA, mean drainages of the vibration technique and control group were 50% and 43% (ES = .29; P = .65). Discussion. In vitro studies suggested flush irrigation had the greatest effect, whereas only vibration was significantly different vs the respective controls. In vivo with tPA, vibration showed promising but not statistically significant results. Results of in vivo experiments without tPA were negative. Conclusion. Agitation techniques, in combination with tPA, may enhance drainage of hemothorax.


2020 ◽  
pp. 58-66
Author(s):  
Ya. I. Uraeva ◽  
I. I. Ivanova ◽  
N. N. Lazarenko ◽  
E. V. Filatova ◽  
I. A. Pankova ◽  
...  

The results of the treatment of women (n = 94) suffering from genital endometriosis are presented. The first (control, n = 30) group of women received standard drug therapy; the second (main, n = 64) group of women additionally had hirudotherapy procedures using medical leeches. The course of treatment consisted of 10–12 procedures. The state of cerebral circulation was assessed according to the rheoencephalography data before and after the treatment, as well as after 1, 3, 6, and 9 months. As a result, in patients in the 2-nd (main) group receiving complex treatment, the state of cerebral circulation improved signifi cantly. Moreover, according to the statistical regression analysis, it was possible to predict its further decrease by two periods ahead, compared with the treatment results in patients in the 1-st (control) group.


2018 ◽  
Vol 36 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Jun Zhou ◽  
Peirui Zhong ◽  
Ying Liao ◽  
Jing Liu ◽  
Yuan Liao ◽  
...  

Objectives To investigate the effects of electroacupuncture (EA) on subchondral bone mass and cartilage degeneration in an experimental animal model of osteoarthritis (OA) induced by ovariectomy (OVX). Methods Ninety 3-month-old female Sprague-Dawley rats were randomly divided into the following three groups (n = 30 each): sham operation without treatment (control group); OVX without treatment (OVX group);, and ovariectomy with EA treatment (EA group). Rats in the EA group received EA treatment from the day of OVX. Ten rats in each group were randomly killed at 4, 8 and 12 weeks after operation. Results EA reduced urine C-terminal cross-linking telopeptide of type I collagen from 4 weeks after OVX, reduced C-terminal cross-linking telopeptide of type II collagen and body weight from 8 weeks after OVX, and increased serum 17β-oestradiol from 4 weeks after OVX compared with the OVX group (all p<0.01). In the EA group, trabecular bone volume ratio, trabecular thickness and trabecular number increased, and trabecular separation were reduced at each time point compared with the OVX group (p<0.05, p<0.01, respectively). In the EA group, osteoprotegerin (OPG) expression was increased and receptor activator of nuclear factor kappa-B ligand (RANKL) expression was reduced at each time point compared with the OVX group (p<0.05, p<0.01, respectively). Mankin scores and mRNA expression of matrix metalloproteinase-13 (MMP-13) were lower in EA versus OVX groups at 12 weeks after OVX (both p<0.01). Conclusion The results suggest that EA inhibits subchondral bone loss by regulating RANK/RANKL/OPG signalling and protects articular cartilage by inhibiting MMP-13 in OVX rats.


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