(1) Background: The present study was carried out to provide new information about the relation between angiogenesis, tumor stage Oral squamous cell carcinoma (OSCC); (2) Materials and methods: Thirty formalin-fixed paraffin embedded blocks were used, 10 of them were previously diagnosed as well differentiated OSCC, 10 moderate differentiated OSCC and 10 poorly differentiated OSCC. To determine the expression of CD31 and D2-40 proteins, streptavidin-biotin immunoperoxidase staining technique was used. The areas with the most vascular density (hot spots) were determined. The stained vessels were counted independently in intratumoral and peritumoral stroma in five areas of hot spot at ×400 magnification; (3) Results: Immunohistochemical staining using CD 31 protein showed that CD31-positive vessels in the peritumoral and intratumoral stroma subjacent to the malignant invading nests which was recorded highest values in poor differentiated OSSC followed by moderate differentiated OSSC then well differentiated OSSC. D2-40 expression was positive in lymphatic vessel in the peritumoral and intratumoral stroma subjacent to the malignant invading nests. Poorly differentiated OSSC tissue sections recorded the highest vessels count followed by moderate differentiated OSSC then well differentiated OSSC. There was statistically significant difference found between the three studied groups regarding CD31 and D2-40 levels. Also there was statistically significant positive correlation found between CD31 level and D2-40 level and vice versa; (4) Conclusion: CD31 and D2-40 are related to stage of OSCC and are consistent with angiogenesis in tumor progression.

Aim: Sca-1+CD31− cells were shown to be endothelial stem/progenitor cells, found in many mammalian tissues, including heart, were able to differentiate into cardiomyocytes in vitro and in vivo. Our previous work indicated that heart derived Sca-1+CD31− cells increased Nr1d1 mRNA level and decreased cells plasticity with aging. However, little is known about how NR1D1 affects Sca-1+CD31− cells plasticity. Methods: Lentiviral vector was used to stably overexpress Nr1d1 in young Sca-1+CD31− cells and to knockdown Nr1d1 in aged Sca-1+CD31− cells. Cell differentiation, proliferation, apoptosis, and cell cycle were evaluated. Results and Conclusions: The overexpression of Nr1d1 in young Sca-1+CD31− cells inhibited cell proliferation and promoted apoptosis. Knockdown of Nr1d1 in aged Sca-1+CD31− cells promoted cell proliferation and inhib-ited apoptosis. Using mouse cardiac myocytes cell line, confirmed the effect of Nr1d1 and indi-cated that Nr1d1 induce Serpina3 expression via Nr1d1 interaction with Nr4a3. Nr1d1 may there-fore be identified as a potent anti-aging receptor and be a therapeutic target for aging relative diseases.

Background: Implantation of an endovascular device disrupts the homeostatic CD31:CD31 interactions among quiescent endothelial cells, platelets, and circulating leukocytes. The aim of this study was to mask endovascu-lar stents with peptides imitating CD31, to mimic the device's surface to resemble that of a healthy vascular endothelium. Methods: Peptide design relied on established trans-homophilic sequences found within domains 1 and 2 of CD31. Subsequently, synthetic peptides were immobilized onto flat CoCr and nitinol discs and their impact on the primary human arterial endothelial cell phenotype was evaluated in vitro. Following this, clinical-grade CoCr and nitinol endovascular devices were coated with one of the peptides that demonstrated the capability to induce a pro-physiologic endothelial phenotype, implanted in the arteries of rabbits, and compared to un-coated controls. Results: Membrane-distal CD31 domains 1 and 2 peptides exhibited a distinct capability to foster a healthy endothelial phenotype in vitro. By day 7 post-aortic implantation, CoCr stents were evenly covered by whole-some endothelial cells, devoid of thrombo-inflammatory signs, in contrast to both bare metal and drug-eluting stents. At day 60, nitinol-coated flow diverters demonstrated enhanced performance in comparison to the control groups for excluding experimental carotid aneurysms, facilitating the formation of a seamless "neo-arterial" wall. Conclusion: Membrane-distal CD31 biomimetic peptides effectively camouflage the device surface, prevent-ing local reactions and promoting rapid and seamless endovascular integration.