BACKGROUND: Teeth and supporting oral tissues are attractive and accessible sources of stem cells. Periodontal ligament stem cells (PDLSC) are readily isolated from extracted third molars, and exhibit the ability to self-renew and differentiate into multiple mesodermal cell fates. Clinical experience suggests that the exact location of periodontal defects affects the oral bone remodeling and wound healing. Compared to the mandible, the maxilla heals quicker and more efficiently. Angiogenesis is key in tissue regeneration including dental tissues, yet few studies focus on the angiogenic potential of PDLSC, none of which considered the differences between upper and lower jaw PDLSC (u-PDLSC and l-PDLSC, respectively).
METHODS: Here we studied the angiogenic potential of u-PDLSC and l-PDLSC and compared the results to well-established mesenchymal stem cells (MSC). Cells were characterized in terms of surface markers, proliferation, and vascular endothelial growth factor (VEGF) secretion, and angiogenic assays were performed. Newly formed capillaries were stained with CD31, and their expression of platelet endothelial cell adhesion molecule (PECAM-1), angiopoietin 2 (ANGPT2), and vascular endothelial growth factor receptor 1 and 2 (VEGFR-1, VEGFR-2) were measured.
RESULTS: Periodontal stem cells from the upper jaw showed a higher proliferation capacity, secreted more VEGF, and formed capillary networks faster and denser than l-PDLSC. Gene expression of angiogenesis-related genes was significantly higher in u-PDLSC than in l-PDLSC or MSC, given that culture conditions were suitable.
CONCLUSIONS: The oral cavity is a valuable source of stem cells, particularly PDLSC, which are promising for oral tissue engineering due to their robust growth, lifelong accessibility, low immunogenicity, and strong differentiation potential. Notably, u-PDLSC exhibit higher VEGF secretion and accelerate capillary formation compared to l-PDLSC or MSC. This study suggests a potential molecular mechanism in capillary formation, emphasizing the significance of precise location isolation of PDLSC.

Objective: To observe whether endothelial cells undergo pyroptosis in the inflammatory periodontal environment by using a model in vivo and in vitro, providing an experimental basis for indepth understanding of the underlying pathogenesis of periodontitis. Methods: According to the classification of periodontal diseases of 2018, gingival tissues were collected from periodontally healthy subjects and patients with stage Ⅲ-Ⅳ, grade C periodontitis, who presented Department of Oral and Maxillofacial Surgery and Department of Periodontology, School of Stomatology, The Fourth Military Medical University from April to May 2022. Immunohistochemical staining was performed to detect the expression level and distribution of gasdermin D (GSDMD), a hallmark protein of cell pyroptosis, in gingival tissues. Periodontitis models were established in each group by ligating the maxillary second molar teeth of three mice for 2 weeks (ligation group). The alveolar bone resorption was determined by micro-CT (mice without ligation treatment were used as the control group), and the colocalization of GSDMD and CD31 were quantitatively analyzed by immunofluorescence staining in gingival tissues of healthy and inflammatory mice. Human umbilical vein endothelial cells (HUVECs) were cultured in vitro and treated with lipopolysaccharide (LPS) of Porphyromonas gingivalis (Pg) combined with adenosine triphosphate (ATP) at various concentrations of 0.5, 1.0, 2.5, 5.0, and 10.0 mg/L, respectively, and the 0 mg/L group was set as the control group at the same time. Scanning electron microscopy was used to observe the morphology of HUVECs. Western blotting was used to detect the expression of gasdermin D-N terminal domains (GSDMD-N) protein and immunofluorescence cell staining was used to detect the expression and distribution of GSDMD. Cell counting kit-8 (CCK-8) was used to detect the proliferative ability of HUVECs, and propidium iodide (PI) staining was used to detect the integrity of cell membrane of HUVECs. Results: Immunohistochemistry showed that GSDMD in gingival tissues of periodontitis was mainly distributed around blood vessels and its expression level was higher than that in healthy tissues. Micro-CT showed that alveolar bone resorption around the maxillary second molar significantly increased in ligation group mice compared with control subjects (t=8.88, P<0.001). Immunofluorescence staining showed significant colocalization of GSDMD with CD31 in the gingival vascular endothelial cells in mice of ligation group. The results of scanning electron microscopy showed that there were pores of different sizes, the typical morphology of pyroptosis, on HUVECs cell membranes in the inflammatory environment simulated by ATP combined with different concentrations of LPS, and 2.5 mg/L group showed the most dilated and fused pores on cell membranes, with the cells tended to lyse and die. Western blotting showed that the expression of GSDMD-N, the hallmark protein of cell pyroptosis, was significantly higher in 2.5 and 5.0 mg/L groups than that in the control group (F=3.86, P<0.01). Immunofluorescence cell staining showed that the average fluorescence intensity of GSDMD in 2.5 mg/L group elevated the most significantly in comparison with that in the control group (F=35.25, P<0.001). The CCK-8 proliferation assay showed that compared to the control group (1.00±0.02), 0.5 mg/L (0.52±0.07), 1.0 mg/L (0.57±0.10), 2.5 mg/L (0.58±0.04), 5.0 mg/L (0.55±0.04), 10.0 mg/L (0.61±0.03) groups inhibited cell proliferation (F=39.95, P<0.001). PI staining showed that the proportion of positive stained cells was highest [(56.07±3.22)%] in 2.5 mg/L group (F=88.24, P<0.001). Conclusions: Endothelial cells undergo significant pyroptosis in both in vivo and in vitro periodontal inflammatory environments, suggesting that endothelial cell pyroptosis may be an important pathogenic factor contributing to the pathogenesis of periodontitis.
目的： 通过体内外模型观察牙周炎局部组织内皮细胞在炎症环境下是否发生焦亡，为探究牙周炎发病机制提供实验依据。 方法： 根据牙周病2018年新分类标准收集无全身疾病、牙周健康者及Ⅲ~Ⅳ期C级牙周炎患者的牙龈组织，免疫组化染色检测牙龈组织中焦亡标志性蛋白消皮素D（GSDMD）的表达水平及分布情况；每组通过结扎3只小鼠上颌第二磨牙2周建立牙周炎模型（结扎组），使用显微CT（micro-CT）检测小鼠牙槽骨吸收情况（以不做结扎处理的小鼠作为对照组）；使用免疫荧光染色对健康及炎症小鼠牙龈组织中血管内皮细胞血小板内皮细胞黏附分子（CD31）与GSDMD共定位进行定量分析；体外培养人脐静脉内皮细胞（HUVECs），分别以质量浓度为0.5、1.0、2.5、5.0、10.0 mg/L牙龈卟啉单胞菌（Pg）脂多糖（LPS）联合腺苷三磷酸（ATP）处理HUVECs，同期设置0 mg/L Pg-LPS组为对照组。使用扫描电镜观察 HUVECs形态，蛋白质印迹法检测GSDMD的N端结构域（GSDMD-N）蛋白表达，细胞免疫荧光染色检测GSDMD蛋白表达及分布，细胞计数试剂盒（CCK-8）检测HUVECs的增殖能力，碘化丙啶（PI）染色检测HUVECs细胞膜的完整性。 结果： 免疫组化结果显示，牙周炎患者牙龈组织中GSDMD主要分布于血管周围，且表达水平较健康组织显著升高；micro-CT结果显示，结扎组小鼠上颌第二磨牙周围牙槽骨吸收较对照组小鼠显著增多（t=8.88，P<0.001）；免疫荧光染色结果显示，结扎组小鼠牙龈组织中血管内皮细胞GSDMD与CD31存在明显的共定位；扫描电镜结果显示，在不同浓度Pg-LPS联合ATP模拟的炎症环境中，HUVECs细胞膜上出现不同大小的孔洞，呈现典型的细胞焦亡形态，其中2.5 mg/L Pg-LPS+ATP组细胞膜上孔洞最多且扩张融合，细胞有裂解死亡的趋势。蛋白质印迹法结果显示，2.5和5.0 mg/L Pg-LPS+ATP组焦亡标志性蛋白GSDMD-N表达显著高于对照组（F=3.86，P<0.01）；细胞免疫荧光结果显示，2.5 mg/L Pg-LPS+ATP组较对照组GSDMD平均荧光强度升高最显著（F=35.25，P<0.001）。CCK-8结果显示，0.5、1.0、2.5、5.0和10.0 mg/L Pg-LPS+ATP组细胞增殖相对值（分别为0.52±0.07、0.57±0.10、0.58±0.04、0.55±0.04和0.61±0.03）均显著低于对照组（1.00±0.02）（F=39.95，P<0.001）。PI染色结果显示，PI阳性细胞数占比在2.5 mg/L Pg-LPS+ATP组最高［（56.07±3.22）%］（F=88.24，P<0.001）。 结论： 牙周炎症环境中内皮细胞发生明显的焦亡现象，提示内皮细胞焦亡可能是造成牙周炎发生的重要致病因素。.

OBJECTIVE: Periodontitis (PD) can cause systematic inflammation and is associated with various metabolic processes in the body. However, robust serum markers for these relationships are still lacking. This study aims to identify novel circulating inflammation-related proteins associated with PD using targeted proteomics.
METHODS: We used population-based, cross-sectional data from 619 participants of the Polish Longitudinal University Study (Bialystok PLUS). Mean pocket probing depth (mPPD) and proportion of bleeding on probing (pBOP) served as exposure variables. Fifty-two inflammation-related proteins were measured using the Olink Target 96 Cardiovascular III and the Olink Target 96 Immune Response panels. Associations between periodontal measures and proteins were tested using covariate-adjusted linear regression models.
RESULTS: At a false discovery rate of < 0.05, we identified associations of mPPD and pBOP with platelet-endothelial cell adhesion molecule-1 (PECAM-1) and tripartite motif-containing protein 21 (TRIM21).
CONCLUSIONS: This study revealed novel associations between PD and serum levels of PECAM-1 and TRIM21. Our results suggest that these proteins might be affected by molecular processes that take place in the inflamed periodontium.
CONCLUSIONS: Novel associations of PECAM-1 and TRIM21 with PD indicate promising serum markers for understanding the disease\'s pathophysiological processes and call for further biomedical investigations.

Platelet endothelial cell adhesion molecule 1 (PECAM-1) is considered an antiplatelet molecule. Previously, we introduced a new parameter called the PECAM-1/thrombus ratio, which indicates the proportion of PECAM-1 in the thrombus and provides a precise description of human platelet activity (in vitro). The aim of this study was to determine whether the PECAM-1/thrombus ratio could serve as a predictive factor for bleeding events during off-pump coronary artery bypass grafting (OPCAB). To achieve this, we collected blood samples from 20 patients scheduled to undergo OPCAB surgery. We assessed the PECAM-1/thrombus ratio by evaluating thrombus formation on collagen fibers under flow conditions. Subsequently, we compared the ability of the PECAM-1/thrombus ratio in predicting bleeding risk with other methods that evaluate hemostasis activity. These methods included assessing platelet P-selectin secretion, platelet exposure of phosphatidylserine, plasma coagulation and fibrinolysis system activity, and thrombus formation using the T-TAS assay. Our findings revealed a positive correlation between the PECAM-1/thrombus ratio and the amount of blood component units transfused (BCUT) during the OPCAB surgery. Furthermore, BCUT did not show any significant correlation with other measured hemostasis parameters. This preliminary study suggests that the PECAM-1/thrombus ratio might be a good predictor of bleeding risk during the OPCAB procedure.

Baseline levels of endotheliopathy are associated with worse respiratory outcomes and mortality in undifferentiated acute respiratory failure (ARF), but knowledge is lacking on the development of endotheliopathy over time in ARF. We, therefore, aimed to evaluate the prognostic significance of trajectories of endotheliopathy during the first days of ARF. We performed a secondary, exploratory analysis of a single-center prospective cohort including 459 patients requiring mechanical ventilation. Based on Days 1-3 Syndecan-1, soluble Thrombomodulin (sTM), and Platelet Endothelial Cell Adhesion Molecule-1 (PECAM-1), we divided patients into subgroups using latent class mixed modeling and correlated subgroups with clinical outcomes using Cox regression. Based on Syndecan-1 and sTM, respectively, we identified two subgroups. Based on PECAM-1, we identified three subgroups. Subgroups based on Syndecan-1 and sTM were identifiable from the baseline levels, but subgroups based on PECAM-1 were not. Patients with persistently high levels of both sTM and PECAM-1 were liberated from mechanical ventilation more slowly (Group high vs. Group low, sTM: hazard ratio [HR]: 0.66, 95% confidence interval [CI]: 0.50-0.88, p = .01, PECAM-1: HR: 0.59, 95% CI: 0.37-0.93, p = .02) and had higher 30-day mortality (sTM: HR: 1.90, 95% CI: 1.20-3.01, p = .01, PECAM-1: HR: 4.25, 95% CI: 1.99-9.07, p < .01). In ARF requiring mechanical ventilation, patients in subgroups with persistently high levels of sTM and PECAM-1 had lower rates of liberation from mechanical ventilation and higher 30-day mortality. However, patients with persistently high levels of sTM were identifiable based on the baseline level, and only the trajectory of PECAM-1 added information to that of the baseline level.

In an in vivo rat model of human exposure to cadmium (Cd; 5 and 50 mg/L, 6 months), whether the supplementation with zinc (Zn; 30 and 60 mg/L, increasing its daily intake by 79% and 151%, respectively) protects against the unfavourable impact of this xenobiotic on the vascular tissue of the abdominal aorta was investigated. The treatment with Cd led to oxidative stress and increased the concentrations of pro-inflammatory interleukin 1β (IL-1β), total cholesterol (TC), triglycerides (TG), and endothelial nitric oxide synthase (eNOS) and decreased the concentration of anti-inflammatory interleukin 10 (IL-10) in the vascular tissue. Cd decreased the expression of intercellular adhesion molecule-1 (ICAM-1), platelet endothelial cell adhesion molecule-1 (PECAM-1), and L-selectin on the endothelial cells. The administration of Zn prevented most of the Cd-induced alterations or at least weakened them (except for the expression of adhesive molecules). In conclusion, Zn supplementation may protect from the toxic impact of Cd on the blood vessels and thus exert a beneficial influence on the cardiovascular system. The increase in the intake of Zn by 79% may be sufficient to provide this protection and the effect is related to the antioxidative, anti-inflammatory, and antiatherogenic properties of this essential element.

Endotheliopathy is suggested as pivotal pathophysiology of sepsis and trauma-associated organ failure, but its role in acute respiratory failure is not yet determined. We investigated if endotheliopathy biomarkers at ICU admission are associated with illness severity and clinical outcomes in patients with acute respiratory failure requiring mechanical ventilation.
We conducted a prospective single-center cohort study including 459 mechanically ventilated adults at ICU admission. Plasma levels of three endotheliopathy biomarkers were measured at ICU admission: Syndecan-1, soluble Thrombomodulin (sTM), and Platelet Endothelial Cell Adhesion Molecule-1 (PECAM-1). The primary outcome was the rate of liberation from mechanical ventilation, which is presented together with the rate of the competing risk of death while still on mechanical ventilation. Secondary outcomes were PaO2/FiO2-ratios on admission and on last measurement in patients dying within five days, and 30-day all-cause mortality. The primary outcome and 30-day all-cause mortality were analyzed using Cox regression, controlled for gender, age, chronic obstructive pulmonary disease, septic shock, heart failure, PaO2/FiO2-ratio at admission, respiratory infection, acute kidney injury, and bilirubin. PaO2/FiO2-ratios were analyzed using linear regression, controlled for age, chronic obstructive pulmonary disease, respiratory infection, and shock.
Patients with high sTM were liberated from mechanical ventilation at a lower rate (adjusted hazard ratio (HR) 0.71, for an increase from the 25th to the 75th percentile, 95% confidence interval (CI) 0.54-0.93, p = 0.01). Patients with high PECAM-1 were liberated from mechanical ventilation at a lower rate, but only during the first 5 days (adjusted HR 0.72, for an increase from the 25th to the 75th percentile, 95% CI 0.58-0.9, p < 0.01). High levels of Syndecan-1 and PECAM-1 were associated with a higher rate of death while still on mechanical ventilation. sTM and PECAM-1 were negatively associated with PaO2/FiO2-ratio at ICU admission and no biomarker was associated with last measured PaO2/FiO2-ratio. High levels of all biomarkers were associated with higher 30-day all-cause mortality.
In acute respiratory failure, endotheliopathy biomarkers are associated with lower rates of liberation from mechanical ventilation, hypoxemia at ICU admission, and 30-day all-cause mortality.

This study investigates the association of intraocular cytokine expression and ultrawide-field fluorescein angiography (UWFA) quantitative imaging biomarkers and their association with angiographical feature response after antivascular endothelial growth factor (VEGF) therapy in diabetic macular oedema (DME).
The IMAGINE DME study is a post hoc imaging biomarker and intraocular cytokine assessment from the DAVE study, a prospective DME clinical trial that included aqueous humour sampling and UWFA imaging. Fifty-four cytokines associated with inflammation and angiogenesis were evaluated through multiplex arrays. UWFA parameters were assessed using an automated feature analysis platform to determine ischaemic and leakage indices and microaneurysm (MA) count. Eyes were classified into UWFA responder or non-responder groups based on longitudinal quantitative UWFA parameter improvement. Cytokine expression was correlated with UWFA metrics and evaluated in the context of therapeutic response.
Twenty-one eyes were included with a mean age of 55±10 years. Increased panretinal leakage index correlated with VEGF (r=0.70, p=0.0005), angiopoietin-like 4 (r=0.77, p=4.6E-5) and interleukin (IL)-6 (r=0.64, p=0.002). Panretinal ischaemic index was associated with tissue inhibitor of metalloproteinases 1 (TIMP-1, r=0.49, p=0.03) and peripheral ischaemia correlated with VEGF (r=0.45, p=0.05). MA count correlated with increased monocyte chemotactic protein-4 (MCP-4, r=0.60, p=0.004) and platelet and endothelial cell adhesion molecule 1 (PECAM-1, r=0.58, p=0.005). Longitudinal MA reduction was associated with decreased baseline VEGF and urokinase receptor (uPAR) (p<0.05). High baseline VEGF and IL-6 were associated with dramatic reduction in macular leakage (p<0.05).
Baseline and longitudinal quantitative UWFA imaging parameters correlated with multiple aqueous humour cytokine concentrations, including VEGF and IL-6. Further research is needed to assess the possible implications of using these findings for evaluating treatment response.

OBJECTIVE: To demonstrate the existence of lymphatics in the canine anterior uvea using lymphatic-specific markers Lyve-1, Prox-1, and podoplanin, the endothelial cell marker CD31, and basement membrane matrix marker collagen IV.
METHODS: Prospective Study.
METHODS: Eight normal globes from animals euthanized for unrelated health problems.
METHODS: Sagittally cut serial sections of six normal canine eyes were immunofluorescence double-stained with Lyve-1 and CD31 and single-stained with colorimetric Prox-1 and collagen IV. Three serial sections from 2 additional eyes were cut in the coronal plane at the level of the ciliary body and immunofluorescence double-stained with Lyve-1 and CD31 to map lymphatic channel distribution. Lymphatics from normal canine lymph nodes were used for validation of podoplanin.
RESULTS: Four of 6 of the sagitally sectioned eyes had Lyve-1-positive lymphatic-like structures that were distinct from CD31-positive blood vessels in the iris base and ciliary body. Both of the coronally sectioned globes had Lyve-1-positive lymphatic-like structures in the ciliary body. The location of these structures was evaluated and found to be diffusely present circumferentially around the ciliary body.
CONCLUSIONS: These results support the existence of lymphatic channels in the anterior uveal tract of the canine eye. This could indicate the presence of a novel uveolymphatic outflow pathway, which may play a role in aqueous humor outflow. Future studies are needed to confirm the existence and elucidate the role of this proposed uveolymphatic outflow pathway and potentially develop novel treatment options for managing glaucoma.

BACKGROUND: Several treatment modalities have been postulated to improve the efficacy of varicose vein treatment. Addition of glycerine to the sclerosing material has been documented to increase its viscosity and subsequently prolong the duration of stability, in addition to the direct sclerosing effect of glycerine. This histological and immunohistochemical study investigated the efficacy of addition of glycerine 72% to sclerotherapy on the human varicose vein.
METHODS: After surgical stripping of great saphenous veins, three equal segments were resected between two clamps. Specimen 1 was injected with saline only, specimen 2 was exposed to foam sclerosant 2%, and specimen 3 was exposed to a mixture of foam sclerosant 2% and glycerine 72%. All segments were left for 5min. Vein segments were then processed for histological and immunohistochemical study.
RESULTS: Microscopically, haematoxylin and eosin-stained specimen 1 showed endothelial swelling, cytoplasmic eosinophilia and pyknotic nuclei. The media showed sarcoplasm vacuolisation and necrosis. Specimen 3 showed hypereosinophilic sarcoplasm of the smooth muscle fibres. Oedema was less evident, with a relative decrease in the thickness of the wall compared with specimen 2. Immunohistochemically, the expression of smooth muscle actin was weak in specimen 3 compared with specimens 1 and 2. Expression of CD31 antibody was much reduced in specimen 2 which showed conserved islands of endothelial cells. By contrast, there was a complete loss of endothelial cells in specimen 3.
CONCLUSIONS: Addition of glycerine 72% to foam sclerosant has a more damaging effect on human vein wall.