Wnt Pathway Inhibitor Delays Fracture Healing by Targeting Ephrin B1 (EFNB1) in Osteoprogenitor Cells

2021 ◽  
Vol 11 (12) ◽  
pp. 2427-2434
Author(s):  
Zexue Zhao ◽  
Pengfei Wu ◽  
Jiwei Tian ◽  
Yifan Yu

Our study assessed the role of Wnt signaling inhibitor (SM04690) in fracture healing and the underlying mechanism. Sprague Dawley (SD) rats were used to establish a fracture model which was then separated into SM04690 group which received SM04690 (50 mg/kg) by intraperitoneal injection once a day for one week, and control group which received saline once a day. After rats were sacrificed, the fractured femurs were harvested to measure femoral strength by stress testing, bone density and volume by CT. Femurs were sliced for immunohistochemical staining. Mesenchymal stem cells (MSCs), endothelial cells, osteoprogenitor cells and osteoblasts were detected by flow cytometer and EFNB1 expression was detected by immunoblotting and PCR. In addition, MSCs were treated with SM04690 (5 uM), followed by detection of EFNB1 expression. SM04690 treatment significantly inhibited EFNB1 expression and reduced bone volume and callus volume as well as decreased ultimate load of bones. Immunohistochemical staining and flow cytometry analysis showed no difference of osteoclast numbers at the fracture site between two groups, but proportion of osteoclasts in the cartilage tissue of SM04690 group was significantly decreased. In addition, the number of osteoblasts, osteoprogenitor cells and endothelial cells was significantly decreased after treatment. Under the conditions favoring osteogenic differentiation, the production of minerals by osteogenic cells was significantly decreased along with upregulated TAZ phosphorylation and downregulated Osterix in SM04690 group. In conclusion, SM04690 delays fracture healing by inhibiting EpRunB1 in osteoprogenitor cells.

Author(s):  
Yanping Gong ◽  
Yang Wang ◽  
Yiqing Zhang ◽  
Liangchen Wang ◽  
Lijuan Wan ◽  
...  

Bone regeneration is a delicate physiological process. Non-union and delayed fracture healing remains a great challenge in clinical practice nowadays. Bone and fat hold a close relationship to remain balanced through hormones and cytokines. Adiponectin is a well-known protein to maintain the hemostasis, which may be an interesting target for fracture healing. Herein, we provided a facile and efficient method to obtain high-purity and high-yield recombinant human adiponectin (ADPN). The biocompatibility and the pharmaceutical behaviors were evaluated in Sprague–Dawley rats. The paracrine effects of adiponectin on bone fracture healing were investigated with a rat tibia fracture model via intrabone injection. Significantly accelerated bone healing was observed in the medulla injection group, indicating the paracrine effects of adiponectin could be potentially utilized for clinical treatments. The underlying mechanism was primarily assessed, and the expression of osteogenic markers, including bone morphogenic protein 2, alkaline phosphatase, and osteocalcin, along with adiponectin receptor 1 (AdipoR1), was markedly increased at the fracture site. The increased bone healing of ADPN treatment may result from both enhanced osteogenic proliferation as well as differentiation. Cell experiments confirmed that the expression of osteogenesis markers increased significantly in ADPN treatment groups, while it decreased when the expression of AdipoR1 was knocked down by siRNA. Our study provided a feasible and efficacious way for bone fracture treatment with local administration of ADPN, which could be rapidly translated into the clinics.


2012 ◽  
Vol 27 (5) ◽  
pp. 301-305 ◽  
Author(s):  
Baohua Zhu ◽  
Chuanming Tong ◽  
Weitao Guo ◽  
Rong Pu ◽  
Guoping Zhang ◽  
...  

PURPOSE: To investigate synergistic suppression of donor liver pre-perfusion with recipient serum (RS) and cobra venom factor (CVF) treatment on hyperacute rejection (HAR) following liver xenotransplantation. METHODS: Guinea-pigs (GP, n=24) and Sprague-Dawley rats (SD, n=24) were recruited. Before transplantation, serum was collected from SD rats and used for preparation of inactivated complements. GP and SD rats were randomly assigned into four groups (n=6), respectively: RS group, CVF group, RS+CVF group and control group. Orthotopic liver xenotransplantation was performed with modified two-cuff technique. The survival time and liver function of recipients, morphological and pathological changes in rat livers were investigated. RESULTS: There was no piebald like change in the recipient livers in all experiment groups. The survival time of recipients in all experiment groups was longer than that in control group (p<0.05). Moreover, the survival time in the RS+CVF group was markedly longer than that in the RS group (p<0.01) and CVF group (p<0.05). The serum ALT level in all experiment groups were lower than that in the control group (p<0.05). Furthermore, the ALT level in the RS+CVF group was significantly lower than that in the CVF group (p<0.05) and RS group (p<0.01). The histological damages were significantly improved when compared with the control group, and the histological damages in the RS+CVF group were milder than those in the remaining groups (p<0.05) CONCLUSION: Pre-perfusion of donor liver with recipient serum and cobra venom factor treatment can exert synergistic suppressive effects on the hyperacute rejection following liver xenotransplantation.


1988 ◽  
Vol 255 (4) ◽  
pp. H717-H721
Author(s):  
H. M. McGowan ◽  
R. Vandongen ◽  
B. Smith

This study examines the effect of dexamethasone (Dex), a phospholipase A2 inhibitor, on the reversal of 1-kidney, 1-clip (1K,1C) hypertension and the synthesis of phospholipase A2-dependent products. Male Sprague-Dawley 1K,1C hypertensive rats [blood pressure (BP) greater than 190 mmHg] were allocated to three groups: two groups were given daily oral doses of Dex (0.142 mg/kg in water) for 72 h, whereas the third group was given water only (controls). One of the Dex-treated groups was then sham unclipped (n = 9), while the other Dex-treated group (n = 8) and the control group (n = 8) were unclipped. Dex attenuated the BP fall in the unclipped (223 +/- 8-148 +/- 9 mmHg) compared with the control unclipped (226 +/- 9-114 +/- 5 mmHg) animals (P less than 0.005). Aortic 6-ketoprostaglandin F1 alpha (6-keto-PGF1 alpha) was reduced in unclipped Dex-treated rats (13.4 +/- 1.2 ng/mg) compared with unclipped control rats (16.3 +/- 1.4 ng/mg; P less than 0.05) but was higher than in the sham-unclipped Dex group (11.5 +/- 1.2 ng/mg; P less than 0.05). Serum thromboxane B2 (TxB2) in the unclipped Dex-treated group was lower than in the unclipped control rats (P less than 0.05) but higher than in sham-unclipped rats (P less than 0.05). Dex significantly increased urinary prostaglandin E2 (PGE2) excretion, whereas urinary 6-keto-PGF1 alpha was unaltered. After unclipping, both urinary PGE2 and 6-keto-PGF1 alpha increased significantly, although there was no obvious difference between Dex-treated and control animals. These findings demonstrate opposite effects of Dex on renal compared with extrarenal prostanoid synthesis and support the hypothesis that attenuation of aortic 6-keto-PGF1 alpha synthesis may be responsible for the smaller fall in BP after unclipping in Dex-treated rats.


2015 ◽  
Vol 60 (1) ◽  
pp. 301-306 ◽  
Author(s):  
Christian Koch ◽  
Matthias Wolff ◽  
Michael Henrich ◽  
Markus A. Weigand ◽  
Christoph Lichtenstern ◽  
...  

ABSTRACTEchinocandins are known as effective and safe agents for the prophylaxis and treatment of different cohorts of patients with fungal infections. Recent studies revealed that certain pharmacokinetics of echinocandin antifungals might impact clinical efficacy and safety in special patient populations. The aim of our study was to evaluate echinocandin-induced aggravation of cardiac impairment in septic shock. Using anin vivoendotoxemic shock model in rats, we assessed hemodynamic parameters and time to hemodynamic failure (THF) after additional central-venous application of anidulafungin (2.5 mg/kg of body weight [BW]), caspofungin (0.875 mg/kg BW), micafungin (3 mg/kg BW), and control (0.9% sodium chloride). In addition, echinocandin-induced cytotoxicity was evaluated in isolated rat cardiac myocytes. THF of the animals in the caspofungin group (n= 7) was significantly reduced compared to that in the control (n= 6) (136 min versus 180 min;P= 0.0209). The anidulafungin group (n= 7) also showed a trend of reduced THF (136 min versus 180 min; log-rank testP= 0.0578). Animals in the micafungin group (n= 7) did not show significant differences in THF compared to those in the control. Control group animals and also micafungin group animals did not show altered cardiac output (CO) during our experiments. In contrast, administration of anidulafungin or caspofungin induced a decrease in CO. We also revealed a dose-dependent increase of cytotoxicity in anidulafungin- and caspofungin-treated cardiac myocytes. Treatment with micafungin did not cause significantly increased cytotoxicity. Further studies are needed to explore the underlying mechanism.


2018 ◽  
Vol 15 (2S) ◽  
pp. 145-152
Author(s):  
S. V. Shukhaev ◽  
E. V. Boiko

Purpose: to compare two types of phacoemulsification parameters (combination ultrasound and torsional US with IP) with estimating the number of postoperative complications caused by intraoperative trauma of corneal endothelial cells.Patients and methods. 72 patients underwent phacoemulsification with IOL implantation. Patients were randomly divided into two groups (main n = 33 and control n = 39). During the aspiration of lens fragments in the main group the combination ultrasound was used, while torsional US with IP was used in the control group. Endothelial cell counting and other examinations were performed 1 day, 1 week and 6 months after the surgery.Results. CDVA in the explored groups 1 week after the surgery was similar: the main group — 0.813 ± 0.228, the control group — 0.765 ± 0.250, There was also no statistically significant difference in the thickness of the cornea between the groups: the main group — 533.48 ± 12.41, the control group — 536.44 ± 10.92. At the same time, a statistically significant difference was found in the density of endothelial cells: the main group: 1871.30 ± 187.41 (after 1 week), 1865 ± 178.9 (after 6 months); control group: 1809.63 ± 225.43 (after 1 week), 1791 ± 230.82 (after 6 months). The percentage of cell loss was, respectively, lower in the main group at all times of observation: 3.90% (after 1 day), 4.54% (after 1 week), 4.9% (after 6 months). In the control group: 7.71% (after 1 day), 9.25% (after 1 week), 10.4% (after 6 months).Conclusions. Data obtained in this study has showed the advantages of combination ultrasound in comparison with torsional US with IP, when performing aspiration of dense lenses. Due to lower consumption of ultrasound energy and higher aspiration rate of the fragments, combination ultrasound can reduce the loss of corneal endothelial cells and decrease the number and severity of postoperative complications associated with it. 


2021 ◽  
Author(s):  
Jiangfeng Liu ◽  
Huijun Kang ◽  
Jiangfeng Lu ◽  
Yike Dai ◽  
Fei Wang

Abstract Purpose: Poor osseointegration is the key reason for implant failure after arthroplasty, whether in osteoporotic or normal bone conditions. To date, osseointegration remains a major challenge. Recent studies have shown that deferoxamine(DFO) can accelerate osteogenesis by activation of the hypoxia signal pathway. The purpose of this study is to test the following hypothesis: after knee replacement, intra-articular injection of DFO will promote osteogenesis and osseointegration with titanium prosthesis in the bones of osteoporotic rats.Materials and Methods: 90 female sprague-dawley rats were used for the experiment. Ovariectomy and knee arthroplasty were performed. Then, the rats were randomly divided into DFO and control group(n=40 per group). The two groups were treated by intraarticular injection of DFO and saline respectively. After 2 weeks, polymerase chain reaction(PCR) and immunohistochemistry were used to evaluate the levels of HIF-1a, VEGF and CD31. After 12 weeks, the specimens were examined by micro CT, biomechanics and histopathology to evaluate osteogenesis and osseointegration.Results: The results of PCR showed mRNA levels of VEGF and CD31 in DFO group were significantly higher than those in control group. The immunohistochemistry results indicated positive cell expressions of HIF-1a, VEGF and CD31 in DFO group were also higher. Compared to control group, the microCT parameters of BMD, BV/TV, TB.N, TB.Th were significantly higher. The maximal pull-out force and the bone-to-implant contact (BIC) value were also higher . Conclusions: The local administration of DFO which is used to activate HIF-1a signaling pathway can promote osteogenesis and osseointegration with the prosthesis in osteoporotic bone.


2015 ◽  
Vol 38 (4) ◽  
pp. 164 ◽  
Author(s):  
Ahmet Bayar ◽  
Ali Turan ◽  
Kanat Gülle ◽  
Meryem Akpolat ◽  
İnci Turan ◽  
...  

Purpose: Angiotensin converting enzyme inhibitors (ACEI) and type I angiotensin receptor blockers (ARB) have been shown to exert significant effects on bone tissue via a local renin-angiotensin-aldosterone system (RAS). The aim of our study was to delineate their influences on fracture healing process. Methods: Sixty adult male Wistar Albino rats were divided into three groups. After undergoing surgical femoral fracture and fixation, the ACEI group received 10 mg/kg of Enalapril, the ARB group received 10 mg/kg of Losartan and the Control group did not receive any medication. Fracture healing was evaluated at second and fifth postoperative weeks by the Lane-Sandhu radiological staging system and by histological scoring system of Huoet al. ACE expression in fracture callus was studied by immunohistochemistry. Results: Both ACEI and ARB groups showed less fibrous tissue in the fracture area at the second week, but the histologic score differences were significant only between Control and ARB groups. At the fifth week, however, both radiological and histological scores for the ACEI group were significantly higher than both ARB and Control groups, while the scores for ARB and Control groups were similar. The presence of ACE expression in fracture callus was also observed. Conclusion: ACEIs had significant positive effects on fracture repair. Losartan failed to display these stimulatory effects, which suggests that local RAS in bone tissue exerts its actions via alternative receptors or pathways than the AT1 receptor.


2017 ◽  
Vol 25 (3) ◽  
pp. 95-98 ◽  
Author(s):  
Nizamettin Guzel ◽  
Emrah Sayit ◽  
Osman Aynaci ◽  
Servet Kerimoglu ◽  
Esin Yulug ◽  
...  

ABSTRACT OBJECTIVES: Ginkgo biloba extract (EGb 761) is a plant extract obtained from the leaves of the G. biloba tree. The aim of this study was to assess the histological and radiological effects of G. biloba extract on fracture healing in an experimental fracture model using rat femurs. METHODS: Forty-eight female Sprague-Dawley rats (weight: 195-252 g; age: 20 weeks) were used in the study. The rats were randomly divided into six groups (n=8). A transverse fracture was made in the middle of the right femur of each rat and fixed with a Kirschner wire. The G. biloba groups received 60 mg/kg oral G. biloba extract once daily. No medication was given to the control groups. On days 7, 21 and 35, both sets of femurs were evaluated radiologically and histopathologically. RESULTS: Histological evaluation revealed that the G. biloba groups had significant differences at 21 and 35 days (p<0.05). The G. biloba group showed a significant difference in terms of bone formation on day 21 when compared to the control group (p<0.05). CONCLUSIONS: This study indicated that the use of G. biloba extract accelerated fracture healing. Both radiological and histological differences were detected, but the histological differences were more remarkable. Level of Evidence I, High Quality Randomized Trial.


2018 ◽  
Vol 19 (11) ◽  
pp. 3629 ◽  
Author(s):  
Wen-Ling Liao ◽  
Jane-Ming Lin ◽  
Shih-Ping Liu ◽  
Shih-Yin Chen ◽  
Hui-Ju Lin ◽  
...  

Diabetic retinopathy (DR) is a severe and recurrent microvascular complication in diabetes. The multifunctional response gene to complement 32 (RGC-32) is involved in the regulation of cell cycle, proliferation, and apoptosis. To investigate the role of RGC-32 in the development of DR, we used human retinal microvascular endothelial cells under high-glucose conditions and type 2 diabetes (T2D) mice (+Leprdb/ + Leprdb, db/db). The results showed that RGC-32 expression increased moderately in human retinal endothelial cells under hyperglycemic conditions. Histopathology and RGC-32 expression showed no significant changes between T2D and control mice retina at 16 and 24 weeks of age. However, RGC-32 expression was significantly decreased in T2D mouse retina compared to the control group at 32 weeks of age, which develop features of the early clinical stages of DR, namely reduced retinal thickness and increased ganglion cell death. Moreover, immunohistochemistry showed that RGC-32 was predominantly expressed in the photoreceptor inner segments of control mice, while the expression was dramatically lowered in the T2D retinas. Furthermore, we found that the level of anti-apoptotic protein Bcl-2 was decreased (approximately 2-fold) with a concomitant increase in cleaved caspase-3 (approximately 3-fold) in T2D retina compared to control. In summary, RGC-32 may lose its expression in T2D retina with features of DR, suggesting that it plays a critical role in DR pathogenesis.


HPB Surgery ◽  
2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Yucel Ozsoy ◽  
Mustafa Ozsoy ◽  
Teoman Coskun ◽  
Kemal Namlı ◽  
Ahmet Var ◽  
...  

Obstructive jaundice damages critical functions in the liver. Nitric oxide modulation would influence liver damage induced by biliary obstruction, and little is known about it Acute cholestasis was induced by bile duct ligation (BDL) in two groups of male Sprague-Dawley rats. L-Arginine or serum physiologic was administered to treatment and control group. Histopathological and immunohistochemical iNOS expression was investigated in hepatic tissue. Plasma enzyme activities were increased in acute cholestasis, and that L-arginine treatment partially but significantly prevented the elevation of these markers of liver damage (P< .05). Also histopathology scoring showed that the liver injury was prevented and immunohistochemical iNOS activity was increased significantly in L-arginine group (P< .05). This study shows that, after 7 days of biliary obstruction, liver damage is well established and exogenous L-arginine treatment partially but significantly prevented the liver injury in acute cholestasis.


Sign in / Sign up

Export Citation Format

Share Document