RESUMO
Background: Tissue-engineered heart valves (TEHVs) are promising new heart valve substitutes for valvular heart disease. The Notch signaling pathway plays a critical role in the development of congenital heart valves. Objective: To investigate the role of the Notch signaling pathway in the construction of TEHVs. Methods: The induced endothelial cells, which act as seed cells, were differentiated from adipose-derived stem cells and were treated with Jagged-1 (JAG-1) protein and γ-secretase inhibitor (DAPT, N-[N-(3,5-difluorophenacetyl)-l-alanyl]-s-phenylglycine t-butyl ester), respectively. Cell phenotypic changes, the expression of proteins relating to the epithelial-mesenchymal transition (EMT), and changes in paxillin expression were detected. Decellularized valve scaffolds were produced from decellularized porcine aortic valves. The seed cells were them inoculated into Matrigel-coated flap scaffolds for complex culture and characterization. Results: JAG-1 significantly reduced apoptosis and promoted the seeded cells' proliferation and migration ability, in contrast to the treatment of DAPT. In addition, the expression of EMT-related proteins, E-cadherin and N-cadherin, was significantly increased after treatment with JAG-1 and was reduced after the application of DAPT. Meanwhile, the adhesive-related expression of paxillin and fibronectin proteins was increased after the activation of Notch1 signaling and vice versa. Of interest, activation of the Notch1 signaling pathway resulted in more closely arranged cells on the valve surface after recellularization. Conclusion: Activation of the JAG-1/Notch1 signaling pathway increased seeded cells' proliferation and migratory ability and promoted the EMT and adhesion of seed cells, which was conducive to binding to the matrix, facilitating accelerated endothelialization of TEHVs.
RESUMO
The present study was to examine the distribution of lymphatic vessels in the penis of normal adult males, which could provide an anatomical basis for improvement of incisions in penile lengthening surgery, and may also help to prevent postoperative refractory edema. Thirteen normal adult male volunteers were recruited for this study. Contrast agent was injected subcutaneously in the foreskin of the penis, and after two minutes magnetic resonance lymphangiography (MRL) was performed. The acquired magnetic resonance images were analyzed to determine the changes in the number and diameter of lymphatic vessels in different parts of the penis. Maximum intensity projections (MIP) and materializes interactive medical image control system (MIMICS) were applied to analyze the overall distribution of lymphatic vessels in the penis. Magnetic resonance imaging (MRI) showed that the lymphatic vessels were in conspicuous contrast with surrounding tissues and could be clearly identified. Penile lymphatic vessels were clearly visible in the root of the penis. At the junction of the penis and the abdominal wall, all lymphatic vessels were found to be concentrated in the dorsal part of the penis. MIP two-dimensional reconstruction showed that the overall distribution of relatively large lymphatic vessels in the dorsal and ventral parts of the penis could be seen clearly on bilateral 45° position, but not inside the abdominal wall because some of lymphatic vessels were overlapped by other tissues in the abdomen. MIMICS three-dimensional reconstruction was able to reveal the overall spatial distribution of lymphatic vessels in the penis from any angle. The reconstruction results showed that there were 1-2 main lymphatic vessels on the root of dorsal penis, which coursed along the cavernous to the first physiological curvature of the penis. Lymphatic vessels merged on both sides of the ventral penis. At the root of the penis, lymphatic vessels gradually coursed to the dorsal surface of the penis and folded at the abdominal wall to the outside, and finally merged into the inguinal lymph nodes. The changes in distribution, number and diameter of the lymphatic vessels in the penis were observed by MRI. MIP and MIMICS reconstructions directly revealed the anatomical features of penile lymphatic vessels such as spatial distribution, overall alignment, and the relations to adjacent structures, drainage and reflux. The study will provide the anatomical basis for penile surgery, penile lymphatic reflux disorders caused by trauma or lymphatic vessels obstruction, and lymph node metastasis in penile cancer.