A Method for Perfusion of Tissue-Isolated Human Tumor Xenografts in Nude Rats to Investigate the Oncostatic Role of the Physiological Nocturnal Melatonin Signal.

The tissue-isolated human tumor perfusion methodology enables the elucidation of physiological melatonin's oncostatic impact on cancer metabolism and physiology. Here we describe an apparatus and surgical technique for perfusing tissue-isolated human tumor xenografts in nude rats in situ that ensures continuous blood flow to and from the tissue. This system and methodology have proven quite successful in examining the receptor-mediated oncostatic effects of the physiological nocturnal melatonin signal on metabolism and physiology in a variety of epithelial and mesenchymal human tumors.

A Method for Growing Tissue-Isolated Human Tumor Xenografts in Nude Rats for Melatonin/Cancer Studies.

The tissue-isolated tumor model permits the investigation of melatonin's influence on human tumor growth and metabolism in laboratory rats in vivo. Here we describe a unique surgical technique for implanting and growing human tumor xenografts on a vascular stalk composed of the nude rat epigastric artery and vein that provides a continuous blood supply from a single source to the tissue-isolated tumor while insuring the absence of extraneous vascular connections. A variety of human tumor types may be implanted and grown utilizing this unique model that may provide a plethora of scientific data from a single tumor examined.

Establishment of efficacy and safety assessment of human adipose tissue-derived mesenchymal stem cells (hATMSCs) in a nude rat femoral segmental defect model.

Human adipose tissue-derived mesenchymal stem cell (hATMSC) have emerged as a potentially powerful tool for bone repair, but an appropriate evaluation system has not been established. The purpose of this study was to establish a preclinical assessment system to evaluate the efficacy and safety of cell therapies in a nude rat bone defect model. Segmental defects (5 mm) were created in the femoral diaphyses and transplanted with cell media (control), hydroxyapatite/tricalcium phosphate scaffolds (HA/TCP, Group I), hATMSCs (Group II), or three cell-loading density of hATMSC-loaded HA/TCP (Group III-V). Healing response was evaluated by serial radiography, micro-computed tomography and histology at 16 weeks. To address safety-concerns, we conducted a GLP-compliant toxicity study. Scanning electron microscopy studies showed that hATMSCs filled the pores/surfaces of scaffolds in a cell-loading density-dependent manner. We detected significant increases in bone formation in the hATMSC-loaded HA/TCP groups compared with other groups. The amount of new bone formation increased with increases in loaded cell number. In a toxicity study, no significant hATMSC-related changes were found in body weights, clinical signs, hematological/biochemical values, organ weights, or histopathological findings. In conclusion, hATMSCs loaded on HA/TCP enhance the repair of bone defects and was found to be safe under our preclinical efficacy/safety hybrid assessment system.

Therapeutic application of cannabidiol on UVA and UVB irradiated rat skin. A proteomic study.

UV phototherapy used in chronic skin diseases causes redox imbalance and pro-inflammatory reactions, especially in the case of unchanged skin cells. To prevent the harmful effects of UV radiation, cannabidiol (CBD) has been used, which has antioxidant and anti-inflammatory properties. Therefore, the aim of this study was to evaluate the effect of CBD on the metabolism of skin keratinocytes in nude rats exposed to UVA/UVB radiation using a proteomic approach. The results obtained with SDS-PAGE/nanoHPLC/QexactiveOrbiTrap show that exposure of rat's skin to UVA/UVB radiation, as well as the action of CBD, significantly modified the expression of proteins involved in inflammation, redox balance and apoptosis. UVA/UVB radiation significantly increased the expression and biological effectiveness of the nuclear factor associated with erythroid factor 2 (Nrf2) and cytoprotective proteins being products of its transcriptional activity, including superoxide dismutase (Cu,Zn-SOD) and the inflammatory response (nuclear receptor coactivator-3 and paralemmin-3), while CBD treatment counteracted and partially eliminated these changes. Moreover, cannabidiol reversed changes in the UV-induced apoptotic pathways by modifying anti-apoptotic and pro-apoptotic factors (apoptosis regulator Bcl-2 and transforming growth factor-ß). The results show that CBD maintains keratinocyte proteostasis and therefore could be suggested as a protective measure in the prevention of UV-induced metabolic changes in epidermal keratinocytes.

Oxidative Stress and Its Consequences in the Blood of Rats Irradiated with UV: Protective Effect of Cannabidiol.

UVA/UVB radiation disturbs the redox balance of skin cells, and metabolic consequences can be transferred into the blood and internal tissues, especially after chronic skin exposure to UV radiation. Therefore, the aim of this study was to evaluate the effect of cannabidiol (CBD), an antioxidant and anti-inflammatory phytocannabinoid, on oxidative stress and its consequences in the blood of nude rats whose skin was exposed to UVA/UVB radiation for 4 weeks. It was shown that CBD penetrated the blood and in UVB-irradiated rats was preferentially located in the membranes of polymorphonuclear leukocytes, which promoted reduction of ROS generation and up-regulation of antioxidant ability by increasing the activity of glutathione reductase and thioredoxin reductase, while the level of reduced glutathione decreased by UV radiation. Consequently, reduction in UV-induced lipid peroxidation, assessed as 4-hydroxynonenal (4-HNE) and 8-isoprostane (8-isoPGF2α) as well as protein modifications, estimated as 4-HNE-protein adducts and protein carbonyl groups, was observed. CBD, by countering the UV-induced down-regulation of 2-arachidonylglycerol, promoted its antioxidant/anti-inflammatory effects by reducing CB1 and increasing PPARγ receptor activation and consequently ROS and TNF-α down-regulation. The results suggest that CBD applied topically to the skin minimizes redox changes not only at the skin level, but also at the systemic level.

[Effects of metformin on papillary thyroid carcinoma in nude rats model].

Objective:To establish an subcutaneous xenotransplanted tumor model of papillary thyroid carcinoma (PTC) and investigate the role of metformin in apoptosis of PTC.Method:Model rats were randomly divided into four groups: control group, Met group and Met+DM group. The tumor volumes were recorded each week. Flow cytometry was used to detect the apoptosis rate of tumor. Immunohistochemistry was used to detect CyclinD1 and the cellular proliferative activity index PCNA and Ki-67.Result:Compared to the control group,there were a significant decrease in tumor volume and antitumor effect in Met and Met+DM groups. The apoptosis rate increased in Met and Met+DM groups. While compared with the control group, the expressions of PCNA,CyclinD1 and Ki-67 significantly decreased in Met and Met+DM groups. There was no difference between Met and Met+DM group.Conclusion:The effect of Metformin on inhibiting tumor growth were related with the imbalance of cell proliferation and apoptosis.

Human Kidney-Derived Cells Ameliorate Acute Kidney Injury Without Engrafting into Renal Tissue.

Previous studies have suggested that CD133+ cells isolated from human kidney biopsies have the potential to ameliorate injury following intravenous (IV) administration in rodent models of kidney disease by integrating into damaged renal tissue and generating specialized renal cells. However, whether renal engraftment of CD133+ cells is a prerequisite for ameliorating injury has not yet been unequivocally resolved. Here, we have established a cisplatin-induced nephropathy model in immunodeficient rats to assess the efficacy of CD133+ human kidney cells in restoring renal health, and to determine the fate of these cells after systemic administration. Specifically, following IV administration, we evaluated the impact of the CD133+ cells on renal function by undertaking longitudinal measurements of the glomerular filtration rate using a novel transcutaneous device. Using histological assays, we assessed whether the human kidney cells could promote renal regeneration, and if this was related to their ability to integrate into the damaged kidneys. Our results show that both CD133+ and CD133- cells improve renal function and promote renal regeneration to a similar degree. However, this was not associated with engraftment of the cells into the kidneys. Instead, after IV administration, both cell types were exclusively located in the lungs, and had disappeared by 24 hours. Our data therefore indicate that renal repair is not mediated by CD133+ cells homing to the kidneys and generating specialized renal cells. Instead, renal repair is likely to be mediated by paracrine or endocrine factors. Stem Cells Translational Medicine 2017;6:1373-1384.

A comparison of commercially available demineralized bone matrices with and without human mesenchymal stem cells in a rodent spinal fusion model.

OBJECTIVE The efficacy of some demineralized bone matrix (DBM) substances has been demonstrated in the spinal fusion of rats; however, no previous comparative study has reported the efficacy of DBM with human mesenchymal stem cells (hMSCs). There is an added cost to the products with stem cells, which should be justified by improved osteogenic potential. The purpose of this study is to prospectively compare the fusion rates of 3 different commercially available DBM substances, both with and without hMSCs. METHODS Posterolateral fusion was performed in 32 mature athymic nude rats. Three groups of 8 rats were implanted with 1 of 3 DBMs: Trinity Evolution (DBM with stem cells), Grafton (DBM without stem cells), or DBX (DBM without stem cells). A fourth group with no implanted material was used as a control group. Radiographs were obtained at 2, 4, and 8 weeks. The rats were euthanized at 8 weeks. Overall fusion was determined by manual palpation and micro-CT. RESULTS The fusion rates at 8 weeks on the radiographs for Trinity Evolution, Grafton, and DBX were 8 of 8 rats, 3 of 8 rats, and 5 of 8 rats, respectively. A significant difference was found between Trinity Evolution and Grafton (p = 0.01). The overall fusion rates as determined by micro-CT and manual palpation for Trinity Evolution, Grafton, and DBX were 4 of 8 rats, 3 of 8 rats, and 3 of 8 rats, respectively. The Trinity Evolution substance had the highest overall fusion rate, however no significant difference was found between groups. CONCLUSIONS The efficacies of these DBM substances are demonstrated; however, the advantage of DBM with hMSCs could not be found in terms of posterolateral fusion. When evaluating spinal fusion using DBM substances, CT analysis is necessary in order to not overestimate fusion.

Transplanted fibroblast cell sheets promote migration of hepatic progenitor cells in the incised host liver in allogeneic rat model.

Cell sheet engineering has been noted as a new and valuable approach in the tissue-engineering field. The objective of this study was to explore a procedure to induce hepatic progenitor cells and biliary duct structures in the liver. Sprague-Dawley rat dermal fibroblast (DF) sheets were transplanted into the incised surface of the liver of F344 nude rats. In the control group, an incision was made without transplantation of the DF sheets. Bile duct (BD)-like structures and immature hepatocyte-like cells were observed in the DF sheet transplant sites. These BD-like structures were cytokeratin-8-positive, while the hepatocyte-like cells were both OV-6-positive and α-fetoprotein-positive as well. The proliferation and differentiation of liver progenitor cells were not influenced by hepatectomy. We also transplanted DF sheets transfected with a plasmid encoding the enhanced yellow fluorescent protein target to mitochondria (pEYFP-Mito) by electroporation, and found that the new structures were pEYFP-Mito-negative. We observed new BD-like structures and immature hepatocytes after transplantation of DF sheets onto incised liver surfaces, and clarified that the origin of these BD-like structures and hepatocyte-like cells was the recipient liver. The present study described an aspect of the hepatic differentiation process induced at the site of liver injury.

Establishment of Efficacy and Safety Assessment of Human Adipose Tissue-Derived Mesenchymal Stem Cells (hATMSCs) in a Nude Rat Femoral Segmental Defect Model

Human adipose tissue-derived mesenchymal stem cell (hATMSC) have emerged as a potentially powerful tool for bone repair, but an appropriate evaluation system has not been established. The purpose of this study was to establish a preclinical assessment system to evaluate the efficacy and safety of cell therapies in a nude rat bone defect model. Segmental defects (5 mm) were created in the femoral diaphyses and transplanted with cell media (control), hydroxyapatite/tricalcium phosphate scaffolds (HA/TCP, Group I), hATMSCs (Group II), or three cell-loading density of hATMSC-loaded HA/TCP (Group III-V). Healing response was evaluated by serial radiography, micro-computed tomography and histology at 16 weeks. To address safety-concerns, we conducted a GLP-compliant toxicity study. Scanning electron microscopy studies showed that hATMSCs filled the pores/surfaces of scaffolds in a cell-loading density-dependent manner. We detected significant increases in bone formation in the hATMSC-loaded HA/TCP groups compared with other groups. The amount of new bone formation increased with increases in loaded cell number. In a toxicity study, no significant hATMSC-related changes were found in body weights, clinical signs, hematological/biochemical values, organ weights, or histopathological findings. In conclusion, hATMSCs loaded on HA/TCP enhance the repair of bone defects and was found to be safe under our preclinical efficacy/safety hybrid assessment system.

Histochemical comparative study of primary and metastatic tumors in nude rats xenotransplanted with KB cells / Estudo histoquímico comparativo da matriz extracelular dc tumores primários e metastáticos em ratos nude xenotransplantados com células KB

A comparative study of metastic and primitive tumors extra-celular matrix in nude rats, xenotransplanted with KB cells, using histochemical methods, was carried out. In both primitive and metastatic tumors it was possible to observe a qualitative and a quantitative variation of matricial components; coexistence of different kinds of fibers; small representation of elastic fibers; presence of acid and sulfated glycosaminoglycans and neutral polysacharyds, and also absence of basal membrane. It is suggested a small interaction between collagenic components and proteoglycan of primary tumors and the proteoglycan, whereas in métastasés this interaction is increased.

Estudou-se comparativamente, através de métodos histoquímicos, a expressão dos componentes da matriz extracelular de tumores primitivos e metastáticos em ratos nude, xenotransplantados com células KB. Em ambas as neoplasias observou-se uma variabilidade tanto qualitativa como quantitativa dos componentes matriciais, coexistência de diferentes tipos de fibras, pouca representatividade de fibras elásticas de glicosaminoglicanas ácidas e sulfatadas e de polissacarídeos neutros, além da ausência de membrana basal.