Development of a Peritoneal Sclerosis Rat Model Using a Continuous-Infusion Pump

2008 ◽  
Vol 28 (6) ◽  
pp. 641-647 ◽  
Author(s):  
Hirotaka Komatsu ◽  
Koichi Uchiyama ◽  
Masahiro Tsuchida ◽  
Naohito Isoyama ◽  
Masafumi Matsumura ◽  
...  

Objective Encapsulating peritoneal sclerosis (EPS) is a serious complication of continuous ambulatory peritoneal dialysis. Previous studies have created peritoneal sclerosis rat models using daily intraperitoneal injection of chlorhexidine gluconate (CG), but this technique is cumbersome and thickening of the peritoneum makes it difficult to evaluate the injection site. We therefore aimed to make a rat model using a continuous-infusion pump. Methods Various concentrations of CG (5%, 8%, 10%, 12%, and 14%) in ethanol were dissolved in saline within the infusion pumps, each of which was placed in the lower abdominal cavity of a male Wister rat. After a peritoneal equilibration test was performed, the rats were sacrificed and the lower anterior parietal and visceral peritoneum was removed. Each excised peritoneum was analyzed by macroscopic and microscopic examinations, including immunohistochemistry for the expression of transforming growth factor-beta 1 (TGF-β1), vascular endothelial growth factor (VEGF), and alpha-smooth muscle actin (αSMA). The results were compared with those of control rats injected with ethanol dissolved in saline within the infusion pump and with no-pump rats. Results Two of the 5 rats in the 12% CG group and 3 of the 5 rats in the 14% CG group died of ileus within 14 days. All the rats in the 5%, 8%, and 10% CG groups survived to 28 days. Macroscopic examination in the 10% CG group showed bowel dilatation, bowel adhesion, and bloody ascites, similar to those seen in human EPS patients. All rats in each CG group showed the same extent of thickening of the submesothelial compact zone, proliferation of collagen fibers, and presence of numerous cells and neovascularization. Within same CG groups, an equal degree of thickening was observed at all sites of the peritoneum. TGF-β1, VEGF, and αSMA were highly expressed in the peritoneum of the 10% CG group. Conclusion We developed a novel method of creating a peritoneal sclerosis rat model using a continuous-infusion pump. Our technique is simple and highly reproducible, and will be useful in the study of peritoneal sclerosis mechanisms.

2021 ◽  
pp. 036354652110285
Author(s):  
Jong Pil Yoon ◽  
Hun-Min Kim ◽  
Jin-Hyun Choi ◽  
Hae Rim Kang ◽  
Dong Hyun Kim ◽  
...  

Background: The healing failure rate after rotator cuff repair is considerably high. Purpose: To evaluate the effect of a porous suture containing transforming growth factor beta 1 (TGF-β1) on the sustained release of TGF-β1 and rotator cuff healing in a rat model. Study Design: Controlled laboratory study. Methods: A porous suture was developed, and its tensile strength was measured. TGF-β1 was delivered using the porous suture, and a TGF-β1 release test and human fibroblast proliferation assay were performed. For the animal experiment, 30 rats were randomly allocated into 3 groups (n = 10 each). A bilateral supraspinatus tendon tear was made in all the rats, and repair was performed. Group 1 received repair only; group 2, repair and a single injection of TGF-β1; and group 3, repair using the porous suture containing TGF-β1. Eight weeks after repair, biomechanical and histological analyses were performed. Results: The porous suture was successfully developed with mechanical properties compatible with the conventional suture, and the sustained release of TGF-β1 from the porous suture was confirmed. In addition, the cell proliferation assay confirmed the biological safety of the porous suture. In the animal experiment, group 3 biomechanically exhibited the largest cross-sectional area and the highest ultimate failure load and ultimate stress (all P < .05). Histological examination revealed that group 3 showed significantly better collagen fiber density and tendon-to-bone maturation than did groups 1 and 2 (all P < .05). Conclusion: The porous suture containing TGF-β1 could sustainedly and safely release TGF-β1, and its use during rotator cuff repair could improve rotator cuff healing, as assessed on the basis of the biomechanical and histological changes in the rat model in this study. Considering the effectiveness, safety, and convenience of the porous suture without extra effort in surgery, the findings of the present study will have a far-reaching effect on the treatment of rotator cuff tears. Clinical Relevance: The porous suture containing TGF-β1 might improve healing after rotator cuff repair.


2004 ◽  
Vol 19 (3) ◽  
pp. 236-239 ◽  
Author(s):  
A. Lebrecht ◽  
C. Grimm ◽  
G. Euller ◽  
E. Ludwig ◽  
E. Ulbrich ◽  
...  

Transforming growth factor beta (TGF-β)1 is thought to be involved in breast carcinogenesis. TGF-β1 acts in an antiproliferative manner in the early stages of breast carcinogenesis, but promotes tumor progression and metastases in the advanced stages of the disease. No data have been published on serum TGF-β1 in breast cancer. We investigated TGF-β1 serum levels in patients with breast cancer (n=135), ductal carcinoma in situ (DCIS) I to III (n=67) or fibroadenoma (n=35), and in healthy women (n=40) to determine its value as a differentiation marker between malignant, pre-invasive and benign diseases and as a predictive marker for metastatic spread. Median (range) TGF-β1 serum levels in patients with breast cancer, DCIS I-III or benign breast lesions and in healthy women were 48.8 (18–82.4) pg/mL, 45.3 (26.9–58.3) pg/mL, 47.2 (17.2–80.5) pg/mL and 51.6 (30.9–65.1) pg/mL, respectively (p=0.2). In breast cancer patients TGF-β1 serum levels showed no statistically significant correlation with tumor stage, lymph node involvement, histological grade, estrogen receptor status and progesterone receptor status. Our data fail to indicate any correlation between serum TGF-β1 levels and clinicopathological parameters of breast diseases. Serum TGF-β1 levels do not provide clinical information in addition to established tumor markers.


2020 ◽  
Vol 9 (24) ◽  
Author(s):  
Chenglei Zhao ◽  
Sean T. Zuckerman ◽  
Chuanqi Cai ◽  
Sreenivasulu Kilari ◽  
Avishek Singh ◽  
...  

Background Venous neointimal hyperplasia and venous stenosis (VS) formation can result in a decrease in arteriovenous fistula (AVF) patency in patients with end‐stage renal disease. There are limited therapies that prevent VNH/VS. Systemic delivery of simvastatin has been shown to reduce VNH/VS but local delivery may help decrease the side effects associated with statin use. We determined if microparticles (MP) composed of cyclodextrins loaded with simvastatin (MP‐SV) could reduce VS/VNH using a murine arteriovenous fistula model with chronic kidney disease. Methods and Results Male C57BL/6J mice underwent nephrectomy to induce chronic kidney disease. Four weeks later, an arteriovenous fistula was placed and animals were randomized to 3 groups: 20 μL of PBS or 20 μL of PBS with 16.6 mg/mL of either MP or MP‐SV. Animals were euthanized 3 days later and the outflow veins were harvested for quantitative reverse transcriptase–polymerase chain reaction analysis and 28 days later for immunohistochemistical staining with morphometric analysis. Doppler ultrasound was performed weekly. Gene expression of vascular endothelial growth factor‐A ( Vegf‐A ), matrix metalloproteinase‐9 ( Mmp‐9 ), transforming growth factor beta 1 ( Tgf‐β1 ), and monocyte chemoattractant protein‐1 ( Mcp‐1 ) were significantly decreased in MP‐SV treated vessels compared with controls. There was a significant decrease in the neointimal area, cell proliferation, inflammation, and fibrosis, with an increase in apoptosis and peak velocity in MP‐SV treated outflow veins. MP‐SV treated fibroblasts when exposed to hypoxic injury had decreased gene expression of Vegf‐A and Mmp‐9 . Conclusions In experimental arteriovenous fistulas, periadventitial delivery of MP‐SV decreased gene expression of Vegf‐A , Mmp‐9 , Tgf‐β1 and Mcp‐1, VNH/VS, inflammation, and fibrosis.


2018 ◽  
Vol 243 (7) ◽  
pp. 601-612 ◽  
Author(s):  
Nathan Cho ◽  
Shadi E Razipour ◽  
Megan L McCain

Cardiac fibroblasts and their activated derivatives, myofibroblasts, play a critical role in wound healing after myocardial injury and often contribute to long-term pathological outcomes, such as excessive fibrosis. Thus, defining the microenvironmental factors that regulate the phenotype of cardiac fibroblasts and myofibroblasts could lead to new therapeutic strategies. Both chemical and biomechanical cues have previously been shown to induce myofibroblast differentiation in many organs and species. For example, transforming growth factor beta 1, a cytokine secreted by neutrophils, and rigid extracellular matrix environments have both been shown to promote differentiation. However, the relative contributions of transforming growth factor beta 1 and extracellular matrix rigidity, two hallmark cues in many pathological myocardial microenvironments, to the phenotype of human cardiac fibroblasts are unclear. We hypothesized that transforming growth factor beta 1 and rigid extracellular matrix environments would potentially have a synergistic effect on the differentiation of human cardiac fibroblasts to myofibroblasts. To test this, we seeded primary human adult cardiac fibroblasts onto coverslips coated with polydimethylsiloxane of various elastic moduli, introduced transforming growth factor beta 1, and longitudinally quantified cell phenotype by measuring expression of α-smooth muscle actin, the most robust indicator of myofibroblasts. Our data indicate that, although extracellular matrix rigidity influenced differentiation after one day of transforming growth factor beta 1 treatment, ultimately transforming growth factor beta 1 superseded extracellular matrix rigidity as the primary regulator of myofibroblast differentiation. We also measured expression of POSTN, FAP, and FSP1, proposed secondary indicators of fibroblast/myofibroblast phenotypes. Although these genes partially trended with α-smooth muscle actin expression, they were relatively inconsistent. Finally, we demonstrated that activated myofibroblasts incompletely revert to a fibroblast phenotype after they are re-plated onto new surfaces without transforming growth factor beta 1, suggesting differentiation is partially reversible. Our results provide new insights into how microenvironmental cues affect human cardiac fibroblast differentiation in the context of myocardial pathology, which is important for identifying effective therapeutic targets and dictating supporting cell phenotypes for engineered human cardiac disease models. Impact statement Heart disease is the leading cause of death worldwide. Many forms of heart disease are associated with fibrosis, which increases extracellular matrix (ECM) rigidity and compromises cardiac output. Fibrotic tissue is synthesized primarily by myofibroblasts differentiated from fibroblasts. Thus, defining the cues that regulate myofibroblast differentiation is important for understanding the mechanisms of fibrosis. However, previous studies have focused on non-human cardiac fibroblasts and have not tested combinations of chemical and mechanical cues. We tested the effects of TGF-β1, a cytokine secreted by immune cells after injury, and ECM rigidity on the differentiation of human cardiac fibroblasts to myofibroblasts. Our results indicate that differentiation is initially influenced by ECM rigidity, but is ultimately superseded by TGF-β1. This suggests that targeting TGF-β signaling pathways in cardiac fibroblasts may have therapeutic potential for attenuating fibrosis, even in rigid microenvironments. Additionally, our approach can be leveraged to engineer more precise multi-cellular human cardiac tissue models.


2017 ◽  
Vol 9 (1) ◽  
pp. 49 ◽  
Author(s):  
Yusrawati Yusrawati ◽  
Dyka Aidina ◽  
Eti Yerizel

BACKGROUND: According to the theory of endothelial dysfunction, the pathogenesis of preeclampsia is associated with the imbalance of angiogenic and anti-angiogenic factors. Transforming growth factor-beta 1 (TGF-β1) has also proposed as a proangiogenic factor that influences preeclampsia. This study was conducted to compare a mean difference of TGF-β1 between preeclampsia and normal pregnancy.METHODS: This study was an observational crosssectional study with 25 subjects of pregnant women with preeclampsia and 25 subjects of normotensive pregnant women. The study was conducted in Dr. Reksodiwiryo Hospital, Bhayangkara Hospital, and Dr. Rasidin Hospital in Padang, Indonesia from October 2015 to January 2016. For the determination of TGF-β1 concentration, peripheral Abstract venous blood samples were taken. The blood samples wereanalyzed by enzyme-linked immunosorbent assay (ELISA) in Biomedical Laboratory, Faculty of Medicine, Andalas University. The mean difference was statically analyzed by independent samples T-test.RESULTS: The mean difference of TGF-β1 was lower in preeclampsia group than normal pregnancy group (2.02±0.99 ng/mL vs. 3.24±2.67 ng/mL; p<0.05).CONCLUSION: The TGF-β1 concentration was lower in pregnant women with preeclampsia. Thus, it may have a role as a marker in preeclampsia.KEYWORDS: preeclampsia, normal pregnancy, transforming growth factor-beta1, TGF-β1


2020 ◽  
Vol 13 (11) ◽  
pp. 397
Author(s):  
Mohamed A. Saleh ◽  
Ahmed M. Awad ◽  
Tarek M. Ibrahim ◽  
Nashwa M. Abu-Elsaad

The therapeutic use of numerous pharmacological agents may be limited due to their nephrotoxicity and associated kidney injury. The aim of our study is to test the hypothesis that the blockade of tyrosine kinase-linked receptors signaling protects against chemically induced nephrotoxicity. To test our hypothesis, we investigated sunitinib as an inhibitor for tyrosine kinase signaling for both vascular endothelial growth factor receptor (VEGFR) and platelet-derived growth factor receptors (PDGFR) against adenine-induced nephrotoxicity. Four groups of adult male Swiss albino mice were investigated: normal group, adenine group, sunitinib group, and the adenine+sunitinib group that received concurrent administration for both adenine and sunitinib. Kidney function and oxidative stress biomarkers were analyzed. Tubular injury and histopathological changes were examined. Renal expression of B-cell lymphoma-2 (Bcl-2), the tumor suppressor p53, transforming growth factor beta-1 (TGF-β1), phospho-extracellular signal-regulated kinase 1/2 (p-ERK1/2), and phospho-signal transducer and activator of transcription (phospho-STAT3) were measured. The results obtained showed significant improvement (p < 0.05) in kidney function and antioxidant biomarkers in the adenine+sunitinib group. Kidney fibrosis and tubular injury scores were significantly (p < 0.05) less in the adenine+sunitinib group and that of p53 expression as well. Furthermore, sunitinib decreased (p < 0.5) renal levels of TGF-β1, p-ERK1/2, and phospho-STAT3 while elevating Bcl-2 expression score. In conclusion, sunitinib diminished adenine-induced nephrotoxicity through interfering with profibrogenic pathways, activating anti-apoptotic mechanisms, and possessing potential antioxidant capabilities.


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