scholarly journals The Effect of Growth Differentiation Factor 8 (Myostatin) on Bone Marrow–Derived Stem Cell–Coated Bioactive Sutures in a Rabbit Tendon Repair Model

Hand ◽  
2018 ◽  
Vol 15 (2) ◽  
pp. 264-270 ◽  
Author(s):  
Kunihide Muraoka ◽  
Wei Le ◽  
Anthony W. Behn ◽  
Jeffrey Yao

Background: We have reported that bioactive sutures coated with bone marrow–derived mesenchymal stem cells (BMSCs) enhance tendon repair strength in an in vivo rat model. We have additionally shown that growth differentiation factor 8 (GDF-8, also known as myostatin) simulates tenogenesis in BMSCs in vitro. The purpose of this study was to determine the possibility of BMSC-coated bioactive sutures treated with GDF-8 to increase tendon repair strength in an in vivo rabbit tendon repair model. Methods: Rabbit BMSCs were grown and seeded on to 4-0 Ethibond sutures and treated with GDF-8. New Zealand white rabbits’ bilateral Achilles tendons were transected and randomized to experimental (BMSC-coated bioactive sutures treated with GDF-8) or plain suture repaired control groups. Tendons were harvested at 4 and 7 days after the surgery and subjected to tensile mechanical testing and quantitative polymerase chain reaction. Results: There were distinguishing differences of collagen and matrix metalloproteinase RNA level between the control and experimental groups in the early repair periods (day 4 and day 7). However, there were no significant differences between the experimental and control groups in force to 1-mm or 2-mm gap formation or stiffness at 4 or 7 days following surgery. Conclusions: BMSC-coated bioactive sutures with GDF-8 do not appear to affect in vivo rabbit tendon healing within the first week following repair despite an increased presence of quantifiable RNA level of collagen. GDF-8’s treatment efficacy of the early tendon repair remains to be defined.

2011 ◽  
Vol 36 (4) ◽  
pp. 271-279 ◽  
Author(s):  
M. Hayashi ◽  
C. Zhao ◽  
K.-N. An ◽  
P. C. Amadio

The effects of growth differentiation factor-5 (GDF-5) and bone marrow stromal cells (BMSCs) on tendon healing were investigated under in vitro tissue culture conditions. BMSCs and GDF-5 placed in a collagen gel were interpositioned between the cut ends of dog flexor digitorum profundus tendons. The tendons were randomly assigned into four groups: 1) repaired tendon without gel; 2) repaired tendon with BMSC-seeded gel; 3) repaired tendon with GDF-5 gel without cells; and 4) repaired tendon with GDF-5 treated BMSC-seeded gel. At 2 and 4 weeks, the maximal strength of repaired tendons with GDF-5 treated BMSCs-seeded gel was significantly higher than in tendons without gel interposition. However, neither BMSCs nor GDF-5 alone significantly increased the maximal strength of healing tendons at 2 or 4 weeks. These results suggest that the combination of BMSCs and GDF-5 accelerates tendon healing, but either BMSCs or GDF-5 alone are not effective in this model.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2531-2531
Author(s):  
Pani A. Apostolidis ◽  
Stephan Lindsey ◽  
William M. Miller ◽  
Eleftherios T. Papoutsakis

Abstract Abstract 2531 Poster Board II-508 BACKGROUND AND HYPOTHESIS. We have previously shown that tumor suppressor p53 is activated in differentiating megakaryocytic (Mk) cells and its knock-down (KD) leads to increased polyploidization and delayed apoptosis in CHRF, a human Mk cell line. Furthermore, bone marrow (BM)-derived Mks from p53−/− mice reach higher ploidy classes in culture. Accordingly, we hypothesized that the role of p53 during megakaryopoiesis is to delimit polyploidization and control the transition from endomitosis by inhibiting DNA synthesis and promoting apoptosis. Here, we test this hypothesis by examining the differential effect of mouse thrombopoietin (rmTpo) on the ploidy of p53−/− and p53+/+ mouse Mk cells. METHODS. 8–10 week-old, male p53−/− mice and p53+/+ littermates were injected once with 1.2 μg rmTpo or saline. On days 2 and 5 after Tpo/saline treatment, tail-bleeding assays were performed to measure bleeding times/volumes, mice were bled for platelet counts and sacrificed to harvest BM. We employed flow cytometry to examine baseline ploidy in BM-resident Mks in p53−/− and p53+/+ mice as well as Mk cells generated from BM progenitors after 4 and 6 days of culture with rmTpo. RESULTS. At steady state, ploidy in BM-resident CD41+ Mk cells was similar in p53−/− and p53+/+ mice: 11.8±2.3% and 10.7±1.3% of p53−/− and p53+/+ Mks, respectively, reaching a ploidy of ≥32N (n=3-4). Platelet counts were 1.3×106±1×105/μl (12.5±1.0% reticulated) and 1.1×106±5×104/μl (12.4±1.3% reticulated) in p53−/− and p53+/+ mice, respectively (n=8). Two days following Tpo treatment of the mice, we did not observe significantly increased platelet levels, while ploidy was marginally affected. However, 5 days following Tpo treatment, we found greater ploidy in the BM in the absence of p53: 22±1.6% 16N and 10.1±0.8% ≥32N Mks in the p53−/− versus 18.6±3.3% 16N and 7.1±1.4% ≥32N Mks in the p53+/+ (n=2). This was accompanied by increased platelet formation: 23.6±8.3% reticulated platelets in the p53−/− versus 17.8±2.6% in the p53+/+ (n=2). Culture of BM cells from non-Tpo treated mice with 50ng/ml rmTpo resulted in a 50% increase in total Mks and increased polyploidy by day 6 of culture: 38.6±4.6% of p53−/− versus 19.2±2.3% of p53+/+ Mks reached ploidy classes of ≥32N (n=3-4, p < 0.01). Lack of p53 led to hyperploid Mk cells; by day 6 of culture 10.3±2.2% of p53−/− Mks were in ploidy classes of 128N and higher, while only 0.6±0.1% p53+/+ Mks achieved such high ploidy (n=3-4). In addition, a 6 day culture with Tpo of BM cells derived from p53−/− and p53+/+ mice pre-treated with Tpo 5 days prior to sacrifice led to more profound polyploidization compared to Mks generated from the non-Tpo treated mice but only in the p53−/− Mks: 48.8±1.1% of p53−/− versus only 17.6±0.2% of p53+/+ Mks reached ploidy ≥32N (n=2). Microarray analysis comparing p53KD to control CHRF cells undergoing Mk differentiation revealed down-regulation of genes coding for platelet surface complex CD41/CD61 and CD62P in the p53KD cells. To examine the possibility of altered functionality of platelets in p53−/− mice, we performed tail-bleeding assays on the mice that did not receive Tpo. Bleeding times and volumes were generally prolonged in the absence of p53 (all p53−/− mice exceeded the 10 min duration of the assay; mean p53−/− and p53+/+ blood loss was 17μl and 10μl, respectively, n=3-4). CONCLUSIONS. Our data indicate that in vivo polyploidization and platelet formation from Mks is increased in the p53−/− relative to p53+/+ mice after Tpo administration. These data are in line with our hypothesis that p53 activation decreases the ability of Mks to respond to Tpo and undergo polyploidization. Additionally, our preliminary data on platelet functionality suggest that p53 may have a role in hemostasis. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 893-893
Author(s):  
Po Yee Mak ◽  
Duncan H Mak ◽  
Yuexi Shi ◽  
Vivian Ruvolo ◽  
Rodrigo Jacamo ◽  
...  

Abstract Abstract 893 ARC (Apoptosis repressor with caspase recruitment domain) is a unique antiapoptotic protein that has been shown to suppress the activation of both intrinsic and extrinsic apoptosis. We previously reported that ARC is one of the most potent adverse prognostic factors in AML and that high ARC protein expression predicted shorter survival and poor clinical outcome in patients with AML (Carter BZ et al., Blood 2011). Here we report how ARC is regulated and its role in inhibition of AML apoptosis and in cell survival. We provide evidence that ARC expression is regulated by MAPK and PI3K signaling. Inhibition of MAPK and PI3K pathways decreased ARC mRNA and protein levels in AML cells. ARC expression in AML cells is upregulated in co-cultures with bone marrow-derived mesenchymal stromal cells (MSCs) and the upregulation is suppressed in the presence of MAPK or PI3K inhibitors. To investigate the role of ARC in apoptosis resistance in AML, we generated stable ARC overexpressing (O/E) KG-1 and stable ARC knock down (K/D) OCI-AML3 and Molm13 cells and treated them with Ara-C and agents selectively inducing intrinsic (ABT-737) or extrinsic (TRAIL) apoptosis. We found that ARC O/E cells are more resistant and ARC K/D cells more sensitive to Ara-C, ABT-737, and TRAIL-induced apoptosis: EC50s of Ara-C, ABT-737, or TRAIL treatment at 48 hours for ARC O/E KG-1 and control cells were 1.5 ± 0.1 μM vs. 83.5 ± 4.6 nM, 2.2 ± 0.2 μM vs. 60.2 ± 3.1 nM, or 0.97 ± 0.03 μg/mL vs. 0.17 ± 0.08 μg/mL, respectively and for ARC K/D OCI-AML3 and control cells were 0.33 ± 0.02 μM vs. 3.4 ± 0.2 μM, 0.24 ± 0.01 μM vs. 1.3 ± 0.1 μM, or 0.13 ± 0.09 μg/mL vs. 0.36 ± 0.03 μg/mL, respectively. Bone marrow microenvironment is known to play critical roles in AML disease progression and in protecting leukemia cells from various therapeutic agent-induced apoptosis. Leukemia cells were co-cultured with MSCs in vitro study to mimic the in vivo condition. ARC was found to be highly expressed in MSCs and stable ARC K/D MSCs were generated. AML cell lines and primary patient samples were co-cultured with ARC K/D or control MSCs and treated with Ara-C, ABT-737, or TRAIL. Interestingly, ARC K/D MSCs lost their protective activity for leukemia cells treated with these agents. EC50s for OCI-AML3 cells co-cultured with ARC K/D or control MSCs for 48 hours treated with Ara-C, ABT-737, or TRAIL were 1.0 ± 0.04 μM vs. 4.5 ± 0.2 μM, 0.15 ± 0.06 μM vs. 0.53 ± 0.02 μM, or 1.4 ± 0.8 μg/mL vs. 8.1 ± 0.3 μg/mL, respectively. In addition, ARC O/E KG-1 cells grew faster and ARC K/D OCI-AML3 and Molm13 cells and ARC K/D MSCs grew slower than their respective controls. We then injected KG-1 cells into mice and found that NOD-SCID mice harboring ARC O/E KG-1 had significantly shorter survival than mice injected with the vector control KG-1 (median 84 vs. 111 days) as shown in the figure. Collectively, results demonstrate that ARC plays critical roles in AML. ARC is regulated by MSCs through various signaling pathways in AML cells, protects leukemia cells from apoptosis induced by chemotherapy and by agents selectively inducing intrinsic and extrinsic apoptosis. ARC regulates leukemia cell growth in vitro and in vivo. The results suggest that ARC is a potential target for AML therapy. In addition, targeting ARC in MSCs suppresses microenvironmental protection of AML cells. Disclosures: No relevant conflicts of interest to declare.


Author(s):  
Ruta Petraitiene ◽  
Vidmantas Petraitis ◽  
Bo Bo Win Maung ◽  
Robert S. Mansbach ◽  
Michael R. Hodges ◽  
...  

Candida endophthalmitis is a serious sight-threatening complication of candidemia that may occur before or during antifungal therapy. Hematogenous Candida meningoencephalitis (HCME) is also a serious manifestation of disseminated candidiasis in premature infants, immunosuppressed children, and immunocompromised adults. We evaluated the antifungal efficacy and pharmacokinetics of the prodrug fosmanogepix (APX001) in a rabbit model of endophthalmitis/HCME. Manogepix (APX001A), the active moiety of prodrug fosmanogepix, inhibits the fungal enzyme Gwt1, and is highly active in vitro and in vivo against Candida spp., Aspergillus spp., and other fungal pathogens. Plasma pharmacokinetics of manogepix after oral administration of fosmanogepix on Day-6 at 25, 50, and 100 mg/kg resulted in plasma Cmax of 3.96±0.41, 4.14±1.1, and 11.5±1.1 μg/ml, respectively, and AUC0-12 of 15.8±3.1, 30.8±5.0, 95.9±14 μg·h/ml, respectively. Manogepix penetrated into the aqueous humor, vitreous, and choroid with liquid to plasma ratios ranging from 0.19 to 0.52, 0.09 to 0.12, and 0.02 to 0.04, respectively. These concentrations correlated with a significant decrease in Candida albicans burden in vitreous (>101-103) and choroid (>101-103) (P≤0.05 and P≤0.001, respectively). Aqueous humor had no detectable C. albicans in treatment and control groups. The tissue/plasma concentration ratios of manogepix in meninges, cerebrum, cerebellum, and spinal cord were approximately 1:1, which correlated with a >102-104 decline of C. albicans in tissue vs control (P≤0.05). Serum and CSF (1→3)-β-D-glucan levels demonstrated significant declines in response to fosmanogepix treatment. These findings provide an experimental foundation for fosmanogepix in treatment of Candida endophthalmitis and HCME and de-risk the clinical trials of candidemia and invasive candidiasis.


Parasitology ◽  
2019 ◽  
Vol 147 (1) ◽  
pp. 108-119 ◽  
Author(s):  
Matheus Marques Milagre ◽  
Renata Tupinambá Branquinho ◽  
Maira Fonseca Gonçalves ◽  
GMP de Assis ◽  
Maykon Tavares de Oliveira ◽  
...  

AbstractBackground:The current drugs for Chagas disease treatment present several limitationsMethods:The sesquiterpene lactone goyazensolide (GZL) was evaluated regarding to cytotoxicity and trypanocidal activity against amastigotes, selectivity index (SI) in vitro, acute toxicity and anti-Trypanosoma cruzi activity in vivo.Results:The in vitro cytotoxicity in H9c2 cells was observed at doses >250 ng mL−1 of GZL and the SI were of 52.82 and 4.85 (24 h) and of 915.00 and 41.00 (48 h) for GZL and BZ, respectively. Nephrotoxicity and hepatotoxicity were not verified. Treatment with GZL of mice infected with CL strain led to a significant decrease of parasitaemia and total survival at doses of 1 and 3 mg kg−1 day−1 by oral and IV, respectively. This last group cured 12.5% of the animals (negativation of HC, PCR, qPCR and ELISA). Animals infected with Y strain showed significant decrease of parasitaemia and higher negativation in all parasitological tests in comparison to BZ and control groups, but were ELISA reactive, as well as the BZ group, but mice treated with 5.0 mg kg−1 day−1 by oral were negative in parasitological tests and survived.Conclusion:GZL was more active against T. cruzi than benznidazole in vitro and presented important therapeutic activity in vivo in both T. cruzi strains.


2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Monica Y. Pechanec ◽  
Tannah N. Boyd ◽  
Keith Baar ◽  
Michael J. Mienaltowski

Abstract Background Tendon injuries amount to one of the leading causes of career-ending injuries in horses due to the inability for tendon to completely repair and the high reinjury potential. As a result, novel therapeutics are necessary to improve repair with the goal of decreasing leg lameness and potential reinjury. Small leucine-rich repeat proteoglycans (SLRPs), a class of regulatory molecules responsible for collagen organization and maturation, may be one such therapeutic to improve tendon repair. Before SLRP supplementation can occur in vivo, proper evaluation of the effect of these molecules in vitro needs to be assessed. The objective of this study was to evaluate the effectiveness of purified bovine biglycan or decorin on tendon proper and peritenon cell populations in three-dimensional tendon constructs. Methods Equine tendon proper or peritenon cell seeded fibrin three-dimensional constructs were supplemented with biglycan or decorin at two concentrations (5 nM or 25 nM). The functionality and ultrastructural morphology of the constructs were assessed using biomechanics, collagen content analysis, transmission electron microscopy (TEM), and gene expression by real time – quantitative polymerase chain reaction (RT-qPCR). Results SLRP supplementation affected both tendon proper and peritenon cells-seeded constructs. With additional SLRPs, material and tensile properties of constructs strengthened, though ultrastructural analyses indicated production of similar-sized or smaller fibrils. Overall expression of tendon markers was bolstered more in peritenon cells supplemented with either SLRP, while supplementation of SLRPs to TP cell-derived constructs demonstrated fewer changes in tendon and extracellular matrix markers. Moreover, relative to non-supplemented tendon proper cell-seeded constructs, SLRP supplementation of the peritenon cells showed increases in mechanical strength, material properties, and collagen content. Conclusions The SLRP-supplemented peritenon cells produced constructs with greater mechanical and material properties than tendon proper seeded constructs, as well as increased expression of matrix assembly molecules. These findings provide evidence that SLRPs should be further investigated for their potential to improve tendon formation in engineered grafts or post-injury.


2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Hossein Yousofi Darani ◽  
Narges Soozangar ◽  
Soliman Khorami ◽  
Fatomeh Taji ◽  
Mortaza Yousofi ◽  
...  

Bothin vitroandin vivomodels have demonstrated that some parasites can interfere with tumor cell growth. The present study investigates the anticancer activity of hydatid cyst protoscolices on WEHI-164 fibrosarcoma cells and baby hamster kidney (BHK) fibroblast cellsin vitro. Those above two cell types were treated with live hydatid cyst protoscolices or left untreated for control groups. After 48 h, lactate dehydrogenase (LDH) and cell counts were assayed for both treated cells and control groups. Following treatment with hydatid cyst protoscolices, cell proliferation of both cell types was inhibited, and lysis of fibrosarcoma cells increased. Based on these results, it appears that hydatid cyst protoscolices have strong anticancer activity, and additional studies are needed to further clarify the mechanisms of this activity.


2020 ◽  
Vol 13 (7) ◽  
pp. 1327-1333
Author(s):  
Soukaina El-Guendouz ◽  
Soumia Zizi ◽  
Youssef Elamine ◽  
Badiaa Lyoussi

Background and Aim: Hexavalent chromium (Cr (VI)) compounds have been shown to induce nephrotoxicity associated with oxidative stress in humans and animals. The aim of the present study was to investigate the nephroprotective effect of bee propolis, as highly antioxidant natural product, in vivo using an animal model. Materials and Methods: First of all, total phenol and flavonoid contents of propolis sample were estimated in vitro. Afterward, to study the protective effect of propolis on renal damages caused by an injection of a single dose of potassium dichromate (15 mg/kg b.wt), 24 male Wister rats were divided into test and control groups. Propolis treatment was performed by oral gavage of 100 mg/kg b.wt/day, while the control groups received water instead. The 24 h urine was collected and blood samples were withdrawn before and after each treatment for further analysis. Results: Propolis revealed to be rich in polyphenols and flavonoids. Chromate provoked a nephrotoxic effect expressed by a drastic decrease in glomerular filtration assessed by creatinine clearance. However, the administration of propolis attenuated the renal damages induced by the chromate. This attenuation can be seen by the increase of creatinine clearance when comparing propolis treated group to the non-treated group. Conclusion: Propolis showed a protective potential against chromate-induced nephrotoxicity through the amelioration of chromate's toxic effects. It might be concluded that propolis could be effective as chemoprotectant in the management of potassium dichromate-induced nephrotoxicity.


1976 ◽  
Vol 54 (6) ◽  
pp. 587-590 ◽  
Author(s):  
David G. Lygre

Inhibition by saccharin of rat liver glucose-6-phosphatase (EC 3.1.3.9) generally decreased as the pH increased in the range pH 4–8. This pattern was exhibited by homogenates from control and alloxan-treated animals assayed each in the absence and presence of 0.2% (w/v) deoxycholate. Saccharin inhibited in competitive fashion with respect to glucose-6-phosphate (glucose-6-P). There was a small increase in Km (glucose-6-P) but not Ki (saccharin) values in alloxan-treated rats when assays were conducted in the absence of deoxycholate. In the presence of this detergent there was no significant difference in these kinetic parameters between the alloxan-treated and control groups. Deoxycholate decreased Km (glucose-6-P) and increased Ki (saccharin) values. Calculations using these kinetic parameters indicate that, under usual hepatic glucose-6-P concentrations and relatively high levels of saccharin in liver, the inhibition by saccharin of glucose-6-phosphatase is unlikely to be of major significance in vivo.


Sign in / Sign up

Export Citation Format

Share Document