Investigation of impacts of decellularized heart extracellular matrix and VEGF on cardiomyogenic differentiation of mesenchymal stem cell through Notch/Hedgehog signaling pathways.

OBJECTIVE: Decellularization is the process to obtain natural scaffolds with tissue integrity and extracellular matrix components, and recellularization is used to produce tissue-like constructs with specific cell types. In this study, rat bone marrow-derived mesenchymal stem cells (rBM-MSCs) were cultured on decellularized heart extracellular matrix. These cells were then induced to differentiate into cardiomyogenic cells under the stimulatory effect of vascular endothelial growth factor (VEGF) and other chemicals. This study aimed to investigate the effect of the cardiac extracellular matrix and VEGF on cardiomyogenic differentiation in the context of the Notch and Hedgehog signaling pathways. METHODS: Heart samples extracted from rats were decellularized by serial application of detergent to remove cells from the tissue, and then recellularized with rBM-MSCs. The recellularized tissue matrices were then analyzed for cardiomyogenesis. Cardiomyogenic differentiation was performed on decellularized heart extracellular matrix (ECM; three-dimensional scaffolds) and culture plates (two-dimensional cell culture system) for 28 days to understand the effects of the heart extracellular matrix. In addition, differentiation was induced with and without the stimulatory effect of VEGF to understand the effect of VEGF on cardiomyogenic differentiation of rBM-MSCs. RESULTS: Immunofluorescence staining showed that decellularization of the heart was performed effectively and successfully. After decellularization process, the heart extracellular matrix was completely free of cells. It was observed that rBM-MSCs transplanted onto the heart extracellular matrix remained viable and proliferated for 21 days after recellularization. The rBM-MSCs promoted cardiomyogenic differentiation in the conventional differentiation medium but were inversely affected by both VEGF and heart extracellular matrix proteins. Lower expression of connexin43 and cardiac troponin I genes was observed in cells induced by either matrix proteins or VEGF, compared to cells differentiated by chemical agents alone. CONCLUSION: In this study, we investigated the effect of decellularized heart extracellular matrix and VEGF on cardiomyogenic differentiation of rBM-MSCs. On the decellularized cardiac extracellular matrix, rBM-MSCs maintained their viability by adhering to the matrix and proliferating further. The adhesion of the cells to the matrix also produced a physical stimulus that led to the formation of histological structures resembling myocardial layers. Chemical stimulation of the decellularized heart extracellular matrix and cardiomyogenic differentiation supplements resulted in increased expression of cardiomyogenic biomarkers through modulation of the Notch and Hedgehog signaling pathways.

Investigation of the effect of pancreatic decellularized matrix on encapsulated Islets of Langerhans with mesenchymal stem cells.

OBJECTIVE: In this study, it was aimed to provide a therapeutic approach for T1DM by encapsulating the pancreatic islets with mesenchymal stem cells and decellularized pancreatic extracellular matrix to support the survival of islets while maintaining their cellular activity. METHOD: Pancreatic extracellular matrix was decellularized using different concentrations of detergent series. After the preparation of the protein-based tissue extracellular matrix was shown to be free of cells or any genetic material by molecular, immunofluorescence and histochemical techniques. Following the homogenization of the decellularized pancreatic extracellular matrix and the analysis of its protein composition by LC-MS, the matrix proteins were incorporated with pancreatic islets and rat adipose tissue-derived MSCs (rAT-MSCs) in alginate microcapsules. Glucose-stimulated insulin secretion property of the islet cells in the microbeads was evaluated by insulin ELISA. The gene expression profile of the encapsulated cells was analyzed by Real-Time PCR. RESULTS: Unlike the protein composition of whole pancreatic tissue, the decellularized pancreas matrix was free of histone proteins or proteins originated from mitochondria. The protein matrix derived from pancreatic tissue was shown to support the growth and maintenance of the islet cells. When compared to the non-encapsulated pancreatic islet, the encapsulated cells demonstrate to be more efficient in terms of insulin expression. CONCLUSION: The extracellular pancreatic matrix obtained in this study was directly used as supplementary in the alginate-based microcapsule enhancing the cell survival. The tissue matrix protein and alginate had a synergistic effect on total insulin secretion, which might have the potential to overcome the insulin deficiency. Despite the improvement in the cell viability and the number, the efficiency of the insulin secretion in response to glucose stimulation from the alginate microcapsules did not meet the expectation when compared with the non-encapsulated pancreatic islets.

Portal Vein Pull-Through Technique and Thrombectomy for Extensive Portal Vein Thrombosis.

BACKGROUND: Herein, a different technique is presented describing complete dissection of the entire portal vein (PV), superior mesenteric vein (SMV), and splenic vein, thus enabling a complete thrombectomy without the risk of uncontrolled hemorrhage due to blind thrombectomy. METHODS: In cases where a thrombectomy would not be an option because of extensive thrombosis involving the confluence of the PV and SMV, small branches of the SMV, including the inferior mesenteric vein, were divided. Both the SMV and splenic vein were encircled separately. Then, the side branches of the PV above the pancreas, left gastric vein on the left side, and superior pancreatoduodenal vein on the right side were divided. The lateral and posterior part of the PV were dissected within the pancreas both from above and below, allowing the main PV completely free from attachments. At this point, the splenic vein and SMV were clamped, and the main PV was divided above the pancreas and then pulled back through the pancreatic tunnel. The thrombus was easily dissected of the vein under direct visualization, and afterward the PV was redirected to its original position. Then, the liver transplant was carried out in a regular fashion. RESULTS: This technique was applied to 2 patients. The first was a 43-year-old man who underwent a right lobe living donor liver transplant because of hepatitis B virus-related cirrhosis. The patient is still alive and well with stable liver function after 15 years of follow-up. The second was a 69-year-old woman who underwent a right lobe living donor liver transplant because of hepatitis C virus and hepatocellular carcinoma. She survived the procedure and her liver function was entirely normal afterward. She died of pneumonia and sepsis 5 months after transplant. CONCLUSIONS: This technique enables complete dissection of the entire PV, SMV, and splenic vein. Thus, complete thrombectomy under direct visualization without the risk of uncontrolled hemorrhage can be performed.

A rare location of benign osteoblastoma: review of the literature and report of a case.

Benign osteoblastoma is a rare primary bone tumor that constitutes approximately 1% of all primary bone tumors. Its occurrence in the craniomaxillofacial region as also rare and represents only 15% of all osteoblastomas. The tumor shows a predilection for the male gender and constitutes less than 1% of all tumors of the maxillofacial region. In the maxillofacial region, the mandible is affected more frequently than the maxilla, and the coronoid process of the mandible is the area most rarely affected by osteoblastoma. Before this report, 53 cases have been reported in the literature. In this report, a rare location of osteoblastoma, namely, the coronoid process of the mandible, is described.

Benign osteoma with Gardner syndrome: review of the literature and report of a case.

Gardner syndrome, a variant of familial adenomatous polyposis, is an autosomal dominant disease characterized by gastrointestinal polyps that develop in the colon as well as in the stomach and upper intestine (duodenum), multiple osteomas, and skin and soft tissue tumors. Cutaneous findings include epidermoid cysts, desmoid tumors, and other benign tumors. Polyps have a 100% risk of undergoing malignant transformation; consequently, early identification and therapy of the disease are critical. Osteoma is a benign neoplasm of bone tissue that is characterized by slow continuous growth and is the most common accompanying bone lesion seen in Gardner syndrome. The authors report a case of Gardner syndrome that was operated on because of the mandibular osteoma.