Letrozole Decreased Testosterone-Induced Cell Proliferation and Prolactin Secretion also Increased Apoptosis in MMQ and GH3 Rat Prolactinoma Cell Lines.

Aromatase enzyme plays an essential role in estrogen-induced tumorigenesis. It is expressed in the normal pituitary and more significantly in prolactinoma tissues. The aim of this study was to investigate the effects of an aromatase inhibitor, letrozole, on MMQ and GH3 rat prolactinoma cell lines and evaluate the possible mechanism of action. MMQ and GH3 cells were characterized with demonstrating aromatase enzyme and estrogen receptor alpha expression by PCR and immunofluorescence staining. After dose optimization for testosterone (T) and letrozole (L), four groups were established: only the testosteron-treated group (T) to detect cell proliferation; only letrozole-treated group (L) to investigate apoptotic effects; testosterone and letrozole concomitant-treated group to demonstrate inhibition of testosterone induced cell proliferation with letrozole treatment s(T + L) and control group (C) with no treatment. The proliferation rate of cells was determined by WST-1. For the detection of apoptotic and necrotic cells, Annexin V and caspase-3 labeling was used. Prolactin and estrogen levels were measured with ELISA, and the mRNA expression of aromatase and Esr1 was also determined. Testosterone induced the proliferation of MMQ and GH3 cells and further increased prolactin and estradiol levels. Adding letrozole to testosterone resulted in decreased cellular proliferation and even induced apoptosis. Also, letrozole administration significantly decreased prolactin and estradiol levels. However, letrozole alone had no effects on proliferation and apoptosis. Gene expression of aromatase and Esr1 was also significantly decreased by letrozole treatment. This in vitro study demonstrated that treatment of testosterone proliferating cells with letrozole resulted in decreased prolactin levels and cell proliferation and induced apoptosis, and further loss of aromatase and Esr1 mRNA expression were observed. Although this is an in vivo study, the results showed unique and novel findings which may easily be adapted to clinical use for further verification.

Comparison of mesenchymal stem cell sheets and chondrocyte sheets in a rabbit growth plate injury model

Background/aim: The treatment of posttraumatic deformities and differences in length between the extremities resulting from physeal injury remains controversial. The aims of this study were to compare the efficacy of tissue-engineered, monolayer, and allogeneic mesenchymal stem cell sheets and chondrocyte sheets for physeal arrest treatment and to investigate cell sheet technology as a novel method for cell transplantation in physeal cartilage repair. Materials and methods: A proximal tibial physeal injury was induced in New Zealand rabbits. Allogeneic mesenchymal stem cells (MSCs) and chondrocytes were cultured in temperature-responsive culture dishes and applied to the iatrogenic partial growth plate defects in single-sheet grafts (cell sheets). Treatment efficacy was determined using radiological measurements, as well as histological and immunohistochemical staining. Results: Treatment with MSCs and chondrocytes prevented endochondral ossification in the physeal plate, and bone growth resumed after treatment in both the MSC and chondrocyte cell groups. We found significant differences in radiological evaluations between pre- and posttreatment measurements in both MSC and chondrocyte groups. Transplanted cells were observed in the damaged area in both of the groups, which differentiated in the direction of growth plate cartilage. Conclusion: Our results support the hypothesis that MSC or chondrocyte transplantation using the cell-sheet technique described in the present study aids in the regeneration of cartilage tissue during physeal arrest after growth plate damage.

Comparative Analysis of the Healing Effects of the Transplanted Cell Sheets to the Experimentally Injured Maxillary Sinuses.

BACKGROUND: In our study, the authors aimed to obtain a live and functional sinus epithelium with mesenchymal stem cells and nasal mucosa epithelial cells from rabbits which are cultured in temperature-responsive culture plates to get a single-layer. METHODOLOGY/PRINCIPAL: Twenty-two female New Zealand rabbits were included in the study. Two of them were used to obtain mesenchymal stem cells. A total of 40 maxillary sinuses were randomly divided into 5 groups: 1) control group which is used to investigate normal rabbit maxillary mucosa, 2) secondary healing group, 3) mesenchymal stem cell graft group, 4) differentiated mesenchymal stem cell group, and 5) nasal mucosal graft group. The animals were sacrificed at the 28th day after the surgery.Scanning electron microscopy, transmission electron microscopy, and immunohistochemical investigations were performed. RESULTS: With these investigations, it was shown that; all graft groups were histologically better than secondary healing group and when the authors compared the graft groups, differentiated mesenchymal stem cell group were the best. CONCLUSION: Our study results showed that endoscopic sinus surgery and treatment with cell sheets, which were generated in temperature-responsive culture dishes, had more functional respiratory epithelium.

Reduction of Inflammation and Enhancement of Motility after Pancreatic Islet Derived Stem Cell Transplantation Following Spinal Cord Injury.

OBJECTIVE: Spinal cord injury (SCI) is a very serious health problem, usually caused by a trauma and accompanied by elevated levels of inflammation indicators. Stem cell-based therapy is promising some valuable strategies for its functional recovery. Nestinpositive progenitor and/or stem cells (SC) isolated from pancreatic islets (PI) show mesenchymal stem cell (MSC) characteristics. For this reason, we aimed to analyze the effects of rat pancreatic islet derived stem cell (rPI-SC) delivery on functional recovery, as well as the levels of inflammation factors following SCI. METHODS: rPI-SCs were isolated, cultured and their MSC characteristics were determined through flow cytometry and immunofluorescence analysis. The experimental rat population was divided into three groups : 1) laminectomy & trauma, 2) laminectomy & trauma & phosphate-buffered saline (PBS), and 3) laminectomy+trauma+SCs. Green fluorescent protein (GFP) labelled rPI-SCs were transplanted into the injured rat spinal cord. Their motilities were evaluated with Basso, Beattie and Bresnahan (BBB) Score. After 4-weeks, spinal cord sections were analyzed for GFP labeled SCs and stained for vimentin, S100ß, brain derived neurotrophic factor (BDNF), 2',3'-cyclic-nucleotide 3'-phosphodiesterase (CNPase), vascular endothelial growth factor (VEGF) and proinflammatory (interleukin [IL]-6, transforming growth factor [TGF]-ß, macrophage inflammatory protein [MIP]-2, myeloperoxidase [MPO]) and anti-inflammatory (IL-1 receptor antagonis) factors. RESULTS: rPI-SCs were revealed to display MSC characteristics and express neural and glial cell markers including BDNF, glial fibrillary acidic protein (GFAP), fibronectin, microtubule associated protein-2a,b (MAP2a,b), ß3-tubulin and nestin as well as antiinflammatory prostaglandin E2 receptor, EP3. The BBB scores showed significant motor recovery in group 3. GFP-labelled cells were localized on the injury site. In addition, decreased proinflammatory factor levels and increased intensity of anti-inflammatory factors were determined. CONCLUSION: Transplantation of PI-SCs might be an effective strategy to improve functional recovery following spinal cord trauma.

Histopathological, immunohistochemical, and biomechanical effects of splenectomy on Achilles tendon healing in rats.

PURPOSE: This study aimed to assess Achilles tendon repair in rats following splenectomy to simulate patients with musculoskeletal system injury who had splenectomy after spleen injury, a situation often seen in orthopedics and traumatology practice. MATERIALS AND METHODS: The study included 32 male Sprague-Dawley rats (10 months old; average weight, 394.5 ± 28.3 g). The rats were fed with standard rodent food ad libitum at 22°C in a dark environment for 12 h. They were divided into two groups, namely the splenectomy (total splenectomy and Achilles tendon repair) and control groups (only Achilles tendon repair; n = 16). Four weeks after the surgery, the rats were euthanized, and their Achilles tendons were examined histopathologically, immunohistochemically, and biomechanically. RESULTS: In the splenectomy group, proinflammatory cytokines, such as interleukin-1ß, tumor necrosis factor-α, and interferon-γ, showed significantly lower values than those in the control group (p ˂0.01); moreover, the levels of anti-inflammatory cytokines like vascular endothelial growth factor, transforming growth factor-ß1, interleukin-2, interleukin-10, and hepatocyte growth factor were significantly higher than in the control group (p ˂ 0.001). The average ultimate tensile strengths were 2.58 ± 0.5 in the splenectomy and 2.78 ± 0.3 in the control group (p = 0.043). The average εUTS values were 0.33 ± 0.5 in the splenectomy and 0.44 ± 0.1 in the control group (p = 0.021). CONCLUSION: Splenectomy may positively influence Achilles tendon healing through modification of the proinflammatory/anti-inflammatory ratio in favor of anti-inflammatory cytokines by causing a decrease in spleen-originated inflammatory cells.

Comparison of Different Sources of Mesenchymal Stem Cells: Palatal versus Lipoaspirated Adipose Tissue.

OBJECTIVES: The purpose of this study was to compare the proliferation and differentiation potential of mesenchymal stem cells (MSCs) derived from palatal adipose tissue (PAT) and lipoaspirated adipose tissue (LAT). MATERIALS AND METHODS: PATs were obtained from 2 healthy female patients undergoing surgery for gingival recession, and LATs were obtained from 2 healthy female patients undergoing plastic surgery. LAT- and PAT-derived MSCs were confirmed by flow cytometry using MSC-specific surface markers. The multilineage differentiation capacity of the MSCs was analyzed. The expression of immunophenotyping, embryonic, and differentiation markers was compared between both MSC lines. The proliferation of PAT- and LAT-MSCs was evaluated using a real-time cell analyzer, and telomerase activity was determined using an ELISA-based TRAP assay. Stem cells isolated from PAT and LAT were analyzed by real-time PCR and whole genome array analysis. RESULTS: The cells isolated from PAT had MSC characteristics. In addition, PAT-MSCs had significantly higher alkaline phosphatase activity and osteogenic potential than LAT-MSCs. Although the proliferation and telomerase activities of LAT-MSCs were higher than those of PAT-MSCs, the difference was not statistically significant. The level of embryonic stem cell markers (Oct4 and Nanog) was higher in LAT-MSCs than in PAT-MSCs. The whole genome array analysis demonstrated that 255 gene sequences were differentially expressed, with more than a twofold change in expression. CONCLUSIONS: This is the first comparative analysis of the isolation and characterization of MSCs from PAT and LAT. PAT is an accessible source of MSCs, which could be used in periodontal and craniofacial tissue engineering.

The distribution of CD44+/CD24- cancer stem cells in breast cancer and its relationship with prognostic factors.

PURPOSE: The purpose of this study was to investigate the correlation between the percentages of CD44+/CD24- cancer stem cells (CSCs) and the clinicopathological and prognostic factors in breast cancer patients. METHODS: Twenty three women who underwent surgery for breast cancer were enrolled in this study. The mean age of the patients was 46.65 years and 52% had early-stage disease. Tumor tissues obtained during surgery were digested enzymatically. CD44+/CD24- cell phenotype was identified by using surface marker antibodies and percentages were determined by surface marker expression of the cells. RESULTS: Sixty five percent of the tumors were positive for estrogen (ER)/ progesterone receptors (PR) and 38% of the tumors were positive for HER-2. All of the patients with hormone receptor positive tumors had ER positive tumors, while only 11 patients had PR positive breast cancer. CD44+/CD24- cells were present in all tumor tissues. The mean proportion of the CD44+/CD24- cells was 1.43±1.6. The mean percentages of CD18+ cells and MUC1+ were 27.9±26.5% and 6.07±11.34%, respectively. The percentage of CD18+ cells was significantly higher in PR positive tumors (p=0.042). There was no significant correlation between the percentage of CD44+/CD24- cells and clinicopathological features. CONCLUSION: This study showed that CD44+/CD24- cells were present in all tumor tissues. The percentage of CD44+/CD24- cells was higher in early-stage disease, yet without statistical significance. No correlation was found between prognostic factors and the percentage of the CD44+/CD24- cells.

Correction: Retinal Electrophysiological Effects of Intravitreal Bone Marrow Derived Mesenchymal Stem Cells in Streptozotocin Induced Diabetic Rats.

[This corrects the article DOI: 10.1371/journal.pone.0156495.].

Effect of bone marrow and adipose tissue-derived mesenchymal stem cells on the natural course of corneal scarring after penetrating injury.

In the present study, we investigate and compare the efficacy of bone marrow- and adipose tissue-derived mesenchymal stem cell (MSCs) in corneal wound healing. A penetrating injury was created in the right corneas of Wistar rats (n = 40). Ten microliters of phosphate-buffered solution (PBS) containing 2 × 10(5) green fluorescent protein (GFP) labeled bone-marrow-derived MSCs to group 1 (n = 15), 10 µl of PBS containing 2 × 10(5) GFP-labeled adipose-tissue-derived MSCs to group 2 (n = 15), 10 µl PBS was injected into anterior chamber in group 3 (n = 10, control). Corneal opacity scoring, in vivo confocal microscopy, and histopathological evaluation were done at the end of 8 weeks. Immunofluorescence sections were evaluated to detect transplanted cells. Immune staining was performed to measure the expression levels of keratocan, aldehyde dehydrogenase (ALDH) and CD34. The gene expression levels of tumor necrosis factor (TNF-α), the interleukin 6 receptor (IL-6R), interleukin 12b (IL-12b), and transforming growth factor beta (TGF-ß1) was measured on corneas. The establishment of stem cells in the corneas of the transplanted groups was confirmed by immunofluorescence staining. The expression of keratocan, ALDH, and CD34 increased in the transplanted groups (p < 0.05). The density of keratocytes increased significantly in both transplanted groups according to the in vivo confocal microscopy data (p < 0.05). The expression of TNF-α, IL-6R, and IL-12b decreased significantly in the transplanted groups (p < 0.05). Based on our findings, we consider that allogeneic stem cells facilitate the regeneration of corneal stroma and can be a cell source for stromal repopulation in diseased cornea.

Retinal Electrophysiological Effects of Intravitreal Bone Marrow Derived Mesenchymal Stem Cells in Streptozotocin Induced Diabetic Rats.

Diabetic retinopathy is the most common cause of legal blindness in developed countries at middle age adults. In this study diabetes was induced by streptozotocin (STZ) in male Wistar albino rats. After 3 months of diabetes, rights eye were injected intravitreally with green fluorescein protein (GFP) labelled bone marrow derived stem cells (BMSC) and left eyes with balanced salt solution (Sham). Animals were grouped as Baseline (n = 51), Diabetic (n = 45), Diabetic+BMSC (n = 45 eyes), Diabetic+Sham (n = 45 eyes), Healthy+BMSC (n = 6 eyes), Healthy+Sham (n = 6 eyes). Immunohistology analysis showed an increased retinal gliosis in the Diabetic group, compared to Baseline group, which was assessed with GFAP and vimentin expression. In the immunofluorescence analysis BMSC were observed to integrate mostly into the inner retina and expressing GFP. Diabetic group had prominently lower oscillatory potential wave amplitudes than the Baseline group. Three weeks after intravitreal injection Diabetic+BMSC group had significantly better amplitudes than the Diabetic+Sham group. Taken together intravitreal BMSC were thought to improve visual function.

Comparison of the early period effects of bone marrow-derived mesenchymal stem cells and platelet-rich plasma on the Achilles tendon ruptures in rats.

INTRODUCTION: This study aims to histopathologically, biomechanically, and immunohistochemically compare the fourth-week efficiencies of local platelet-rich plasma (PRP) and bone marrow-derived mesenchymal stem cell (rBM-MSC) treatments of the Achilles tendon ruptures created surgically in rats. MATERIALS AND METHODS: The study included 35 12-month-old male Sprague Dawley rats, with an average weight of 400-500 g. Five rats were used as donors for MSC and PRP, and 30 rats were separated into MSC, PRP, and control groups (n = 10). The Achilles tendons of the rats were cut transversely, the MSC from bone marrow was administered to the MSC group, the PRP group received PRP, and the control group received physiological saline to create the same surgical effect. In previous studies, it was shown that this physiological saline does not have any effect on tendon recovery. Thirty days after the treatment, the rats were sacrificed and their Achilles tendons were examined histopathologically, immunohistochemically, and biomechanically. RESULTS: The use of rBM-MSC and PRP in the Achilles tendon ruptures when the tendon is in its weakest phase positively affected the recovery of the tendon in histopathologic, immunohistochemical, and biomechanical manners compared to the control group (p < 0.05). While the levels of pro-inflammatory cytokines TNF-α, IFNγ, and IL 1ß were significantly low, the levels of anti-inflammatory cytokines and growth factors playing key roles in tendon recovery, such as IL2, VEGF, transforming growth factor-beta, and HGF, were significantly higher in the MSC group than those of the PRP and control groups (p < 0.05). In the MSC group, the [Formula: see text] (mm) value was significantly higher (p ˂ 0.05) than that in the PRP and control groups. CONCLUSION: rBM-MSC and PRP promote the recovery of the tendon and increase its structural strength. The use of PRP and MSC provides hope for the treatment of the Achilles tendon ruptures that limit human beings' functionalities and quality of life, particularly for athletes. It is thought that the use of MSC can be more effective for tendon healing; hence, more extensive and advanced studies are needed on this topic.

Effects of mesenchymal stem cells and VEGF on liver regeneration following major resection.

PURPOSE: The study aims to determine the effects of mesenchymal stem cell (MSC) therapy and a combination therapy of MSCs transfected with vascular endothelial growth factor (VEGF) for liver regeneration after major resection. METHODS: Thirty-eight rats were divided into four groups: group 1: control (sham operation); group 2: control (70 % hepatic resection); group 3: 70 % hepatic resection + systemically transplanted MSCs; and group 4: 70 % hepatic resection + systemically transplanted MSCs transfected with the VEGF gene. MSCs were injected via the portal vein route in study groups 3 and 4. Expression levels of VEGF, fibroblast growth factor (FGF), platelet-derived growth factor (PDGF), epidermal growth factor (EGF), transforming growth factor (TGF), hepatocyte growth factor (HGF), and augmenter of liver regeneration (ALR) were analyzed in the remnant liver tissue. We investigated the levels of angiogenic factors, VEGF-receptor, angiopoietin-1 (Angpt1) and Angpt2. Biochemical parameters of liver function in blood samples were measured and a histologic assessment of the livers was performed. The postoperative liver weight and volume of each rat were measured 14 days after surgery. RESULTS: The expression levels of all measured growth factors were significantly increased in groups 3 and 4 compared to the control groups. The levels of Angpt1 and Angpt2 correlated with levels of VEGF and thus were also significantly higher in the study groups. There were significant differences between the estimated liver weights and volumes of group 4 and the resected controls in group 2. With the exception of portal inflammation, levels of all histological parameters were observed to be higher in MSC-treated groups when compared with the resected controls in group 2. CONCLUSIONS: Transplanted stem cells and MSCs transfected with VEGF significantly accelerated many parameters of the healing process following major hepatic resection. After the injection of MSCs and VEGF-transfected MSCs into the portal vein following liver resection, they were engrafted in the liver. They increased bile duct and liver hepatocyte proliferation, and secreted many growth factors including HGF, TGFß, VEGF, PDGF, EGF, and FGF via paracrine effects. These effects support liver function, regeneration, and liver volume/weight.

The Effect of Everolimus on Scar Formation in Glaucoma Filtering Surgery in a Rabbit Model.

PURPOSE: To investigate the efficiency of everolimus on the prevention of postoperative scar in a rabbit model of glaucoma filtering surgery in comparison with mitomycin-C (MMC). MATERIALS AND METHODS: Thirty New Zealand albino rabbits were randomly assigned into 3 groups, each including ten rabbits: an everolimus group (Group 1), a MMC group (Group 2), and a sham group (Group 3). A limbal-based trabeculectomy was performed on the right eyes of all the rabbits. For 28 days following surgery, the eyes were evaluated in terms of intraocular pressure (IOP), morphological and biomicroscopic changes, and complications in the bleb. On the 28th day, four eyes randomized from each group were enucleated and histologically and immunohistochemically analyzed. Transforming growth factor-ß1 (TGF-ß1), metalloproteinase (MMP-2, MMP-9), and proliferative cell nuclear antigen (PCNA) expressions in each group were evaluated. The terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) method was used for apoptosis. RESULTS: Bleb survival was statistically significantly longer for a period in Group 1 compared to Group 2. When postoperative IOPs of three groups were measured, it was seen that there is significant IOP reduction in all three groups. However, there were increases in the mean IOP values beginning from the 5th day in Group 2 and from the 3rd day in Group 3 while in Group 1 mean IOP values began to increase beginning from 10th day and the mean IOP values in Group 1 remained at a lower level in comparison to the other groups for 28 days (p < 0.05). The expressions of TGF-ß1, MMP-2, MMP-9, and PCNA were reduced in Group 1 compared to other groups. TUNEL positive apoptotic cells were significantly increased in Group 1 compared to other groups (p < 0.05). CONCLUSION: Everolimus appears to suppress the proliferation of fibroblast and thus may provide an effective treatment strategy in glaucoma filtering surgery.

The Effects of Adipose Tissue-Derived Mesenchymal Stem Cell Transplantation During the Acute and Subacute Phases Following Spinal Cord Injury.

AIM: To investigate the effectiveness of rat adipose tissue-derived (rAT) mesenchymal stem cell (MSC) transplantation on the functional restoration and regeneration of spinal cord injury (SCI). MATERIAL AND METHODS: Six of 48 Wistar albino rats were sacrificed to obtain MSCs, and the remaining rats were divided randomly into six groups. SCI was performed using the clip compression method. The control and transplantation groups were injected with physiological saline and a rAT-MSC suspension at the injury sites, respectively. Each animal was evaluated using the Basso, Beattie and Bresnahan (BBB) rating system and sacrificed at 28 days post-injury period (p.i.). The regeneration process was evaluated based on immunostaining against ß3-tubulin, BDNF, CNTF, and CNPase. RESULTS: rAT-MSC transplantation into the SCI site substantially improved the tissue regeneration and functional recovery (p < 0.05). However, the rAT-MSC transplantation at 9 days p.i. was not more efficient on functional recovery than the transplantation immediately after injury. The expression of ß3-tubulin, BDNF and CNTF at the injury site indicated the potential for functional regeneration. CONCLUSION: The adaptive nature of rat-MSCs enabled the remodulation and regeneration of the lesion site, decreasing the importance of transplantation time in the treatment of SCI.

Use of Adipose-Derived Mesenchymal Stem Cells to Accelerate Neovascularization in Interpolation Flaps.

OBJECTIVE: Interpolation flaps are commonly used in plastic surgery to cover wide and deep defects. The need to, wait for 2 to 3 weeks until the division of the pedicle still, however, poses a serious challenge, not only extending treatment and hospital stay, but also increasing hospital expenses. To solve this problem, we have aimed to use the angiogenic potential of stem cells to selectively accelerate neovascularization with a view to increasing the viability of interpolation flaps and achieving early pedicle removal. MATERIALS AND METHODS: A total of 32 rats were allocated to 2 groups as control (N = 16) and experiment (N = 16). The cranial flaps 6 × 5 cm in size located on the back of the rats were raised. Then, a total suspension containing 3 × 10(6) adipose-derived mesenchymal stem cells (ADSC) tagged with a green fluorescent protein (GFP) was injected diffusely into the distal part of the flap, receiving bed, and wound edges. In the control group, only a medium solution was injected into the same sites. After covering the 3 × 5 cm region in the proximal part of the area where the flap was removed, the distal part of the flap was adapted to the uncovered distal area. The pedicles of 4 rats in each group were divided on postoperative days 5, 8, 11, and 14. The areas were photographed 7 days after the pedicles were released. The photographs were processed using Adobe Acrobat 9 Pro software (San Jose, CA) to measure the flap survival area in millimeters and to compare groups. Seven days after the flap pedicle was divided, the rats were injected with 250 mCi Tc-99 mm (methoxy-isobutyl-isonitrie) from the penile vein, and scintigraphic images were obtained. The images obtained from each group were subjected to a numerical evaluation, which was then used in the comparison between groups. The flaps were then examined by histology to numerically compare the number of newly formed vessels. Neovascularization was also assessed by microangiography. In addition, radiographic images were obtained by mammography and evaluated quantitatively. RESULTS: An evaluation of statistical results revealed a significant increase in the flap survival area of the group on stem cell treatment in comparison to the control group. In scintigraphic examinations, the rate of radioactive substance retention was significantly higher in the stem cell group, relative to the control group. Histopathologic examination showed that the capillary density in the stem cell group was higher than that in the control group. Green fluorescent protein had been used to label ADSC in the experiment and it was found by immunofluorescence staining that endothelial samples of control animals did not have GFP (+) cells, whereas all the animals in the experiment group had GFP (+) cells. The comparison of microangiographic images of the experiment and control groups demonstrated significantly elevated vascularity in the former, relative to the latter. DISCUSSION: It has been established in the current study that ADSC injection worked well in speeding up the neovascularization of interpolated flaps and reducing the time of pedicle division. It seems possible to minimize the morbidity of interpolated skin flaps with mesenchymal stem cell therapy at an appropriate dose and for an appropriate length of time.

The effects of dental pulp stem cells on bone regeneration in rat calvarial defect model: micro-computed tomography and histomorphometric analysis.

OBJECTIVE: Stem cell therapies may be applicable to all fields of medicine, including craniomaxillofacial surgery. Dental pulp stem cells also have significant osteogenic properties. This study aimed to evaluate the influence of dental pulp stem cells on bone regeneration and to ascertain whether or not there was any superiority over traditional methods. DESIGN: In this study, 15 non-immunodeficient Wistar albino rats were used. The rats were divided into three groups: (1) untreated control group; (2) hydroxyapatite tri-calcium-phosphate (HA/TCP) paste; (3) human dental pulp derived stem cells (DPSC) mixed with HA/TCP paste (HA/TCP+DSPC group, n=10). Two symmetrical full-thickness cranial defects were created on each parietal region (10 defects for each group). The animals were sacrificed 8 weeks post-surgery and samples were analyzed by microcomputer tomography (µ-CT) and histomorphometry. RESULTS: The calcification rate and bone mineral density (BMD) values in Group 3 were found to be significantly higher than in the other two groups. Radiographically, bone regeneration was greater in Group 2 compared with the control group. However, there was no significant difference between Groups 2 and 1 in respect of histological analysis. CONCLUSIONS: According to the results of the present study, DPSCs may be a suitable factor for bone tissue engineering because they can be easily obtained and differentiate into bone cells.

IL-6 originated from breast cancer tissue-derived mesenchymal stromal cells may contribute to carcinogenesis.

Tumor microenvironment is an important factor, which sustains and promotes the tumors by inflammatory signals. Interleukin-6 (IL-6) is known as a multifunctional cytokine, which is a major activator of the signaling pathway of Janus kinases (JAKs)/signal transducer and activator of transcription 3 (STAT3). In this study, we aimed to investigate the effect of IL-6 in the tumor microenvironment on carcinogenesis. For this purpose, healthy breast tissue-derived stromal cells (HBT-SCs) and malign breast tissue-derived stromal cells (MBT-SCs) were co-cultured with MCF-7 (human breast adenocarcinoma cell line) cells using semipermeable membranes. The cell proliferation was monitored with water-soluble tetrazolium (WST) and carboxyfluorescein succinimidyl ester (CFSE) assays. Protein levels were measured by enzyme-linked immunosorbent assay (ELISA) and Western blot hybridization, while gene expressions were measured by real-time PCR. The results demonstrated that IL-6 protein levels increased significantly in the supernatants of MBT-SCs when they were co-cultured with MCF-7 cells. In accordance with this, the expression of IL-6 was significantly higher in MBT-SCs. Additionally, the expression of STAT3 in MCF-7 cells increased slightly when they were co-cultured with MBT-SCs. Considering together, there is an important interaction between tumor microenvironment and tumor cells mediated by IL-6 signaling. Thereby, the targeting on IL-6 signaling in the treatment of cancer might effectively prevent the tumor progression.

Neuroprotective effects of intravitreally transplanted adipose tissue and bone marrow-derived mesenchymal stem cells in an experimental ocular hypertension model.

BACKGROUND AIMS: The purpose of this study was to investigate the neuroprotective effects of bone marrow bone marrow-derived and adipose tissue-derived mesenchymal stromal cells (MSCs) that were intravitreally transplanted in an experimental ocular hypertension (OHT) model. METHODS: An OHT rat model was generated by means of intracameral injection of hyaluronic acid into the anterior chamber. MSCs labeled with green fluorescence protein were transplanted intravitreally 1 week after OHT induction. At the end of the second and fourth weeks, retinal ganglion cells were visualized with the use of a flat-mount retina method and were evaluated by means of immunofluorescence staining against green fluorescence protein, vimentin, CD105, and cytokines (interleukin [IL]-1Ra, prostaglandin E2 receptor, IL-6, transforming growth factor-ß1, interferon-γ and tumor necrosis factor-α). RESULTS: The retinal ganglion cell numbers per area were significantly improved in stem cell-treated OHT groups compared with that in the non-treated OHT group (P < 0.05). The results of immunohistochemical analyses indicated that a limited number of stem cells had integrated into the ganglion cell layer and the inner nuclear layer. The number of cells expressing proinflammatory cytokines (interferon-γ and tumor necrosis factor-α) decreased in the MSC-transferred group compared with that in the OHT group after 4 weeks (P < 0.01). On the other hand, IL-1Ra and prostaglandin E2 receptor expressions were increased in the rat bone marrow-derived MSC group but were more significant in the rat adipose tissue-derived MSC group (P < 0.01). CONCLUSIONS: After intravitreal transplantation, MSCs showed a neuroprotective effect in the rat OHT model. Therefore, MSCs promise an alternative therapy approach for functional recovery in the treatment of glaucoma.

Cross effects of resveratrol and mesenchymal stem cells on liver regeneration and homing in partially hepatectomized rats.

In this study, we examined the effect of preoperatively administered resveratrol (RV) and mesenchymal stem cells (MSCs) on regeneration of partially hepatectomized rat liver. We also evaluated the effect of RV on homing of MSCs. MSCs were isolated from bone marrow and cultured in vitro. Wistar albino rats were randomly divided into four groups. In groups, rats received (1) no treatment, (2) single dose RV, (3) MSCs and (4) RV plus MSCs before partial hepatectomy (PH). Injected MSCs were traced by labeling them with green fluorescent protein, and liver regeneration was determined by comparison of liver weight gain, histological examination and immunohistochemical staining with proliferating cell nuclear antigen (PCNA) for mitotic cells. The expression levels of tumor necrosis factor -alpha (TNF-α), interleukin-6 (IL-6) and hepatocyte growth factor (HGF) were also determined in the parafin sections of liver specimens with immunohistochemical staining. Administration of RV and MSCs separately or together enhanced liver regeneration despite decreasing the TNF-α and IL-6 expression. This positive contribution was probably due to direct raising effect on HGF for RV and HGF expression for MSCs that we demonstrated with immunohistochemical staining. Additionally, RV increased the homing of MSCs in liver probably related to life prolonging effect on MSCs. These results indicate that preoperative RV as well as MSCs application enhances liver regeneration after partial hepatectomy in rats. Paying attention to RV about the effect on liver regeneration and homing of MSCs might be the goal of further investigations.

Role of Mesenchymal Stem Cells Transfected With Vascular Endothelial Growth Factor in Maintaining Renal Structure and Function in Rats with Unilateral Ureteral Obstruction.

OBJECTIVES: Mesenchymal stem cells hold promise for renal disease treatment. Vascular endothelial growth factor may heal tubule-interstitial fibrosis in unilateral ureteral obstruction by inhibiting epithelial-mesenchymal transition. We investigated the protective effect of vascular endothelial growth factor in transfected mesenchymal stem cells in unilateral ureteral obstruction-induced renal injury in rats. MATERIALS AND METHODS: Male Wistar Albino rats (32 rats; weight, 250-300 g) were divided into 4 equal groups: group 1, control; group 2, unilateral ureteral obstruction; group 3, unilateral ureteral obstruction and mesenchymal stem cells; and group 4, unilateral ureteral obstruction and vascular endothelial growth factor-transfected mesenchymal stem cells. Vascular endothelial growth factor-transfected mesenchymal stem cells were administered intravenously before onset of unilateral ureteral obstruction. On day 14, the rats were killed and kidneys were retrieved. Tubular necrosis, mononuclear cell infiltration, and interstitial fibrosis were evaluated in paraffin blocks. We evaluated green fluorescent protein-positive and vascular endothelial growth factor-positive cells; anti-inflammatory (Prostaglandin E2 receptor) and interleukin 1 receptor antagonist), proinflammatory/anti-inflammatory (interleukin 6), and proinflammatory (MPO) cytokine expression levels; and levels of nitric oxide; transforming growth factor ß1, E-cadherin, and hydroxyproline. RESULTS: Green fluorescent protein-positive cells were negative in the renal parenchyma in groups 1 and 2 and positive in groups 3 and 4. Vascular endothelial growth factor levels were significantly higher in group 4. Transforming growth factor ß1, nitric oxide, and E-cadherin levels were significantly higher in the unilateral ureteral obstruction than control group; however, in the study groups, these values were not significantly different from the unilateral ureteral obstruction group. In stem cell-transplanted tissue samples, EP3, interleukin 1 receptor antagonist, and interleukin 6 levels were elevated, but MPO expression levels were low. Although there were significant differences for tubular necrosis and fibrosis in group 2, there were significant reductions in tubular injury and fibrosis in groups 3 and 4. CONCLUSIONS: Systemic stem cells transplanted into the kidney protected against unilateral ureteral obstruction-induced renal epithelial-mesenchymal transition and renal fibrosis.