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Background: Erythroid cells contribute to embryonic organ development and adult tissue repair supplying oxygen to tissues. During mouse development, the primitive erythroid cells produced in the extraembryonic blood islands of the yolk sac begin to circulate as immature and nucleated erythroblasts with the onset of cardiac contractions around embryonic day 9.5 (E9.5). On the other hand, the definitive erythroid progenitors derived from the yolk sac and arterial vessels colonize the fetal liver, where they mature into small, enucleated definitive erythrocytes that are released into circulation at E11.5. In many cases, however, erythroblasts are also generated in situ during the development of tissue vasculature. We hypothesized that the properties of erythroid cells generated by peripheral tissue hematopoiesis may differ from those of contemporaneously circulating erythroid cells because hematopoiesis is spatiotemporally distinct from typical primitive and definitive hematopoiesis., Methods: Comparative in situ protein expression analyses of erythroid cells in developing tongue, circulation, and liver of fetal mice were performed at E12.5 and E14.5, using immunofluorescence staining of several marker proteins for erythroid and endothelial cells., Results: At E12.5, irregularly elongated immature vascular endothelial cells, many of which were in contact with nucleated erythroblasts, were distributed in the developing tongue. In the three fetal locations examined (tongue, circulation, and liver), most erythroid cells at E12.5 expressed CD31, which is involved in cell-cell interactions; however, the expression was downregulated by E14.5. Interestingly, at E12.5, several erythroblasts strongly expressing CD31 were found in the tongue, but less abundant in the circulation and fetal liver. Nearly all erythroblasts in E12.5 fetuses expressed primitive erythroid cell-specific βH1-globin; however, those strongly expressing the embryonic globin were scattered, particularly in the tongue, fewer in the circulation and fetal liver. On the contrary, erythroid cells expressing adult β1-globin were scarcely found in the tongue, which is in stark contrast to those in the circulation and fetal liver, where nearly all erythroid cells weakly expressed β1-globin at the embryonic stage. At E14.5, the number of βH1-globin-expressing cells drastically decreased; however, it was still significantly higher in the tongue than in the circulation and fetal liver. In all three locations, β1-globin accumulation and the enucleation of erythroid cells progressed uniformly and rapidly from E12.5 to E14.5., Conclusion: The results indicate that primitive erythroblasts in the tongue highly express CD31, mature more slowly, and are replaced by definitive erythroid cells more slowly than those in the circulation and fetal liver. Primitive erythroblasts produced together with immature vascular endothelial cells during vasculogenesis in the developing tongue may perform functions other than oxygen supply, such as regulating vascular remodeling., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2024 Elsevier GmbH. All rights reserved.)

Introduction: Endothelial cells (ECs) play a crucial role in many treatments for cardiovascular diseases, such as blood vessel repair, tissue engineering, and drug delivery. The process of differentiating these cells is complex and involves various sources and numerous molecular and cellular events. Differentiating pluripotent stem cells (PSCs) into endothelial cells are one of the most effective sources for creating ECs in the lab and offers great potential for regenerative medicine. However, different cell types can appear during differentiation process., Objectives: This study presents a reliable and reproducible protocol for efficiently differentiating human pluripotent stem cells (hPSCs) into mature endothelial cells with high purity (>98%)., Methods: FLK1 + cells were isolated from hPSCs using fluorescence-activated cell sorting (FACS). Then isolated FLK1 + cells differentiated into high-purity endothelial cells (ECs) by adding endothelial growth factors (VEGF, FGF, and EGM-2 medium). The differentiated ECs were extensively characterized by evaluating key endothelial markers and assessing their functional abilities, such as tube formation and response to angiogenic signals. Finally, the ECs were further purified using a second FACS step with a CD31 antibody., Results: The differentiated hPSC-derived endothelial cells (hPSC-ECs) expressed high levels of PECAM-1 (CD31), VE-cadherin (CD144), and von Willebrand factor (vWF), with more than 98% of the cells showing these markers. Additionally, the hPSC-ECs formed tubular structures and effectively took up acetylated fluorescently-labeled low-density lipoprotein (DiI-ac-LDL), demonstrating their functionality as endothelial cells., Conclusion: Our study clarifies the molecular mechanisms involved in the differentiation of hPSCs into endothelial cells, emphasizing key signaling pathways important for determining endothelial cell fate. These findings provide a framework for the scalable production of transplantable endothelial cells, representing a significant advancement in personalized therapies and tissue engineering for regenerative medicine., Competing Interests: Conflicts of Interest The authors declare no conflict of interest., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

This study introduced a hydrogel dressing, termed SODex-gel, which was constructed by establishing Schiff base and hydrogen bonds with the precursors of oxidized dextran (ODex) and succinic dihydrazide (SD)-modified sodium alginate (SD- mod -SA). Through comprehensive in vitro and in vivo studies, the adhesive properties, self-healing capabilities, hemostatic potential, and wound healing efficacy of the SODex-gel dressing were meticulously evaluated. The 1 H NMR, FTIR, and TGA analyses confirmed the fabrication of the SODex-gel dressing and its constituent elements. Scanning electron microscopy (SEM) imaging showcased the uniform pore structures in the SODex-gel dressing. In vitro assessments demonstrated that the SODex-gel dressing was noncytotoxic and exhibits strong adhesion, enabling it to attach to various surfaces. Noteworthy findings from studies of mouse liver incisions and tail amputation models proved the hemostatic ability of the SODex-gel dressing. Moreover, their remarkable wound-healing capabilities were prominently demonstrated through the treatment of a mouse model afflicted with burn skin injuries. Evidence of neovascularization effects was corroborated by the upregulation of CD31 and vascular endothelial growth factor (VEGF) expression in the treated skin samples. Collectively, the experimental data unequivocally established that the SODex-gel dressing is a promising therapeutic approach to accelerate wound recovery, thereby exhibiting substantial potential for clinical applications in treating burn injuries.

Epithelioid hemangiosarcoma (EH), a rare histological variant of hemangiosarcoma, is reported in various animal species, including humans, dogs, cows, horses, and cats. Epithelioid hemangiosarcomas are composed of highly pleomorphic epithelioid cells arranged in cords, islands, nests, or solid cellular areas, similar to epithelial neoplasms. Moreover, in humans, approximately 50% of EHs have cytoplasmic immunolabeling for cytokeratin AE1/AE3 (CK AE1/AE3), making it challenging to distinguish them from carcinomas. This retrospective study assessed the CK AE1/AE3 immunolabeling in canine EH cases from 5 veterinary institutions. Immunohistochemistry for CD31 and CK AE1/AE3 was performed on 30 cases. CK AE1/AE3 immunolabeling was detected in 43% (13/30) of cases, with cytoplasmic labeling ranging from 5% to 100% of neoplastic cells. All tumors consistently had membranous immunolabeling for CD31. The CK AE1/AE3 immunolabeling pattern in canine EHs closely resembled those documented in humans, indicating a similar diagnostic challenge. Therefore, it is recommended to include a vascular immunohistochemistry marker, such as CD31, whenever EH is suspected, particularly in small incisional cutaneous and subcutaneous biopsies., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: T.T.N.W. is employed by Antech Diagnostics and Mars Petcare Science & Diagnostics. The remaining authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Extracranial arteriovenous malformations (eAVMs) are complex vascular lesions characterized by anomalous arteriovenous connections, vascular instability, and disruptions in endothelial cell (EC)-to-mural cell (MC) interactions. This study sought to determine whether eAVM-MCs could induce endothelial-to-mesenchymal transition (EndMT), a process known to disrupt vascular integrity, in the eAVM microenvironment. eAVM and paired control tissues were analyzed using RT-PCR for EC ( CD31 , CD34 , and CDH5 ) and EndMT-specific markers ( SNAI1 , SNAI2 , ACTA2/α-SMA , N-cadherin / CDH2, VIM) . Immunohistochemistry (IHC) was also performed to analyze MC- (PDGFR-β and α-SMA), EC (CD31, CD34, and CDH5), and EndMT-specific markers (CDH2 and SNAI1) in sequential paraffin-embedded sections of eAVM patient biopsies and in adjacent normal tissue biopsies from the same patients. Furthermore, eAVM-MCs and MCs from normal paired tissues (NMCs) were then isolated from fresh human surgical samples using flow cytometry and co-cultured with normal human umbilical vein vascular endothelial cells (HUVECs), followed by analysis of CD31 by immunofluorescence. RT-PCR analysis did not show a significant difference in the expression of EC markers between eAVM tissues and controls, whereas expression of EndMT-specific markers was upregulated in eAVM tissues compared to controls. IHC of eAVMs and paired control tissues demonstrated regions of significant perivascular eAVM-MC expansion (PDGFR-β+, and α-SMA+) surrounding dilated, morphologically abnormal vessels. These regions contained endothelium undergoing EndMT as evidenced by loss of CD31, CD34, and CDH5 expression and upregulation of the EndMT-associated genes CDH2 and SNAI1. Isolated eAVM-MCs induced loss of CD31 in HUVECs when grown in co-culture, while NMCs did not. This study suggests that the eAVM endothelium surrounded by expanded eAVM-MCs undergoes EndMT, potentially leading to the formation of dilated and fragile vessels, and implicates the eAVM-MCs in EndMT initiation and eAVM pathology.

Voice abuse, chronic cough, laryngeal surgery, and tracheal intubation may lead to injury and subsequent repair/remodeling in the vocal fold mucosa. Periostin is known to be involved in airway remodeling and is also associated with various otolaryngological diseases. D-β-aspartic acid is the major isomer of D-aspartic acid found in tissues of elderly individuals. In ischemic heart disease, increased CD31 expression has been observed around cardiomyocytes during remodeling, and endothelial proliferation has been reported at these sites. In this study, we investigated the expression and role of CD31, CD34, D-β-aspartic acid, and periostin in the formation of laryngeal granulation tissue. This retrospective study involved five patients who underwent surgical treatment for laryngeal granulation tissue. The expressions of CD31, CD34, D-β-aspartic acid, and periostin in surgical samples were investigated by immunohistochemistry. Histologically, the specimens showed inflammatory cell infiltration, fibrin exudation, fibrosis, and neovascularization, but no tumor cells. No stratified squamous epithelial covering was observed. The expression of periostin and D-β-aspartic acid was also observed in the specimens. CD31-positive cells (endothelial cells) and CD34-positive cells (progenitors of endothelial cells) were observed in the specimens. Our results indicate that the overexpression of CD31, CD34, D-β-aspartic acid, and periostin may play a role in the pathogenesis of laryngeal granulation tissue, and we speculate that D-β-aspartic acid and periostin could serve as novel biomarkers and therapeutic targets for laryngeal granulation tissue.

Transforming growth factor-β (TGFβ) and FoxP3 regulatory T cells (Treg) are involved in human breast carcinogenesis. This topic is not well documented in canine mammary tumors (CMT). In this work, the tumoral TGFβ expression was assessed by immunohistochemistry in 67 malignant CMT and its correlation to previously determined FoxP3, VEGF, and CD31 markers and other clinicopathologic parameters was evaluated. The high levels of TGFβ were statistically significantly associated with skin ulceration, tumor necrosis, high histological grade of malignancy (HGM), presence of neoplastic intravascular emboli and presence of lymph node metastases. The observed levels of TGFβ were positively correlated with intratumoral FoxP3 (strong correlation), VEGF (weak correlation) and CD31 (moderate correlation). Tumors that presented a concurrent high expression of TGFβ/FoxP3, TGFβ/VEGF, and TGFβ/CD31 markers were statistically significantly associated with parameters of tumor malignancy (high HGM, presence of vascular emboli and nodal metastasis). Additionally, shorter overall survival (OS) time was statistically significantly associated with tumors with an abundant TGFβ expression and with concurrent high expression of TGFβ/FoxP3, TGFβ/VEGF, and TGFβ/CD31. The presence of lymph node metastasis increased 11 times the risk of disease-related death, arising as an independent predictor of poor prognosis in the multivariable analysis. In conclusion, TGFβ and Treg cells seem involved in tumor progression emerging as potential therapeutic targets for future immunotherapy studies.

Background: Silver nanoparticles (AgNPs) are increasingly known to have anticancer effects, but few studies have examined their adverse effects, so the underlying mechanisms are not yet fully understood. The current study investigated the critical influence of AgNPs on angiogenesis in 4T1 breast cancer-bearing mice., Methods: The sub-lethal dose of AgNPs (0.25 mg/kg) was carried out. Female BALB/c mice (N = 35) were divided into 7 groups; normal control, cancer control, AgNPs control (one dose of (0.25 mg/kg) AgNPs), single dose AgNPs before cancer, single dose AgNPs after cancer, 5 doses AgNPs after cancer, and doxorubicin. 4T1 breast cancer cell induction was performed subcutaneously on the left flank. Intraperitoneal (IP) administration of AgNPs and doxorubicin was carried out for all studied groups., Results: Weight gain was normal in all study groups except the doxorubicin-treated group. Administering AgNPs before cancer induction promotes tumorigenesis, raises MMP-2 and MMP-9 activity, and increases CD31 and Ki67 expression. The cancer control group experienced the same outcomes. On the other hand, depending on the administered doses, the injection of AgNPs after tumor induction resulted in a notable decrease in tumor volume. In the doxorubicin-treated group, similar results were observed, while a dose of AgNPs‌ before cancer induction lead to increasing tumor volume compared to the cancer control group. The differences of biochemical markers including LDH, ALP, AST, ALT, BUN, and Cr between different groups were not significant. Significant differences were seen among all studied groups except doxorubicin and single dose AgNPs before cancer groups for serum TAC levels., Conclusions: It appears that AgNPs are considered a double-edged sword in the fight against cancer. AgNPs not only have anti-cancer effects on tumor size and angiogenesis, but they also might have cancer-stimulating roles. To confirm this conclusion, more detailed investigations are needed., Competing Interests: Declarations Ethics approval All animal experiments were following the National Institutes of Health guide for the care and use of laboratory animals (NIH Publications No. 8023, revised 1978) and approved by Ethics Committee of Tehran University of Medical Sciences, Tehran, Iran (IR.TUMS.MEDICINE.REC.1396.2759). Competing interest The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Assessing the molecular profiles of bladder cancer (BC) from patients with locally advanced or metastatic disease provides valuable insights, such as identification of invasive markers, to guide personalized treatment. Currently, most molecular profiling of BC is based on highly invasive biopsy or transurethral tumor resection. Liquid biopsy takes advantage of less-invasive procedures to longitudinally profile disease. Circulating tumor cells (CTCs) isolated from blood are one of the key analytes of liquid biopsy. In this study, we developed a protein and mRNA co-analysis workflow for BC CTCs utilizing the graphene oxide (GO) microfluidic chip. The GO chip was conjugated with antibodies against both EpCAM and EGFR to isolate CTCs from 1 mL of blood drawn from BC patients. Following CTC capture, protein and mRNA were analyzed using immunofluorescent staining and ion-torrent-based whole transcriptome sequencing, respectively. Elevated CTC counts were significantly associated with patient disease status at the time of blood draw. We found a count greater than 2.5 CTCs per mL was associated with shorter overall survival. The invasive markers EGFR, HER2, CD31, and ADAM15 were detected in CTC subpopulations. Whole transcriptome sequencing showed distinct RNA expression profiles from patients with or without tumor burden at the time of blood draw. In patients with advanced metastatic disease, we found significant upregulation of metastasis-related and chemotherapy-resistant genes. This methodology demonstrates the capability of GO chip-based assays to identify tumor-related RNA signatures, highlighting the prognostic potential of CTCs in metastatic BC patients., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

The tissue preparations of the pelvic veins obtained during laparoscopy were examined. The expression of markers of proliferation (Ki-67), apoptosis (p53), and angiogenesis (CD31, CD34), as well as estrogen and progesterone receptors in women with pelvic varicose veins was assessed by the immunohistochemical method. A decrease in the median expression of the proliferation marker (Ki-67) and estrogen and progesterone receptors and simultaneous increase in the expression of apoptosis marker (p53) and activation of angiogenesis processes (markers CD31 and CD34) were observed with increasing the severity of the disease. These data extend our understanding of the pathogenetic mechanisms of pelvic varicose veins and contribute to the development of methods of pathogenetically based targeted therapy., (© 2024. Springer Science+Business Media, LLC, part of Springer Nature.)

We investigated the localization of both CD31- and endomucin-expressing vessels in mouse dental pulp to elucidate their relationship with dentin formation. The maxillae of C57BL/6 male mice (1, 4, 8, 12, and 56 weeks old) were fixed with 4% paraformaldehyde solution, and cryosections (12-μm-thick) were prepared. Immunofluorescence was performed using anti-CD31 and anti-endomucin antibodies, and calcein labeling was conducted to elucidate relationships with dentin formation. At 1 week, many CD31-expressing (CD31 (+)) and endomucin-expressing (endomucin (+)) vessels were observed throughout the dental papilla. At 4 weeks, CD31 (+) and endomucin (+) vessels decreased in the crown and increased in the root of dental pulp. At 12 weeks, CD31 (+) and endomucin (+) vessels were detected at the root apex, but not in coronal pulp. At 56 weeks, few CD31 (+) and endomucin (+) vessels were observed in dental pulp. Both CD31(+) and endomucin (+) vessels were detected directly beneath calcein-labeled dentin at all sites. These results suggest the presence of CD31 (+) and endomucin (+) vessels in dental pulp and their contribution to dentin formation., Competing Interests: VThe authors declare that there are no competing interests., (2024 The Japan Society of Histochemistry and Cytochemistry.)

Liver cancer is characterized by hypervascularization. Anti-angiogenic agents may normalize the tumor vasculature and improve the efficacy of other treatments. The present study aims to investigate the anti-angiogenic effect of Plasmodium infection in a mouse model of implanted liver cancer cells. HepG2 cells were injected into the left liver lobe of nude mice as a model of in situ hepatic tumorigenesis. Plasmodium yoelii parasitized erythrocytes were administered in the animal model of liver cancer to introduce Plasmodium infection. The tumor growth and microvascular density were determined in the presence or absence of Plasmodium infection. The expression levels of hypoxia-inducible factor 1α (HIF-1α) and angiogenesis-related factors were evaluated using western blotting and reverse transcription-quantitative PCR analysis. The results demonstrated that Plasmodium infection suppressed tumor growth and vascularization in the mouse model of implanted HepG2 cells. Plasmodium parasites reduced the expression of pro-angiogenic factors (vascular endothelial growth factor A and angiopoietin 2), matrix metalloproteinases [(MMP)2 and MMP9] and inflammatory cytokines [tumor necrosis factor α, interleukin 6 (IL)-6) and IL-1β] in both hepatic and tumor tissues. HIF-1α was downregulated in both hepatic and tumor tissues upon Plasmodium infection, and HIF-1α overexpression rescued angiogenesis and tumor growth under the condition of Plasmodium infection. In conclusion, the results of the present study demonstrated the anti-angiogenic and anti-tumorigenic effects of Plasmodium infection on liver cancer through downregulating HIF-1α expression, indicating that Plasmodium parasites could be developed as an intervention strategy to restrain neo-angiogenesis in liver cancer., Competing Interests: The authors declare that they have no competing interests., (Copyright: © 2024 Wu et al.)

Background: Basal Cell Carcinoma (BCC) is the most common form of skin cancer, characterized by its low metastatic potential yet considerable diversity in clinical and dermatoscopic presentation. Advances in dermatoscopy have significantly improved the early detection of BCC, revealing specific patterns that guide diagnosis and management. Parallelly, immunohistochemical markers have been explored for their potential to elucidate the underlying tumor biology and prognosis, with particular focus on angiogenesis, melanocytic activity, and lymphangiogenesis., Objective: This study aims to investigate the correlations between dermatoscopic features and the immunohistochemical expressions of CD34, CD31, Melan-A, and D2-40 in BCC, through a comprehensive analysis of 100 cases We sought to determine whether visual dermatoscopic patterns correlate with the molecular characteristics defined by immunohistochemical staining, potentially enhancing diagnostic accuracy., Methods: A total of 100 cases of clinically and histopathologically confirmed BCC were prospectively analyzed, employing standard dermatoscopic techniques for lesion evaluation and immunohistochemical staining for CD34, CD31, Melan-A, and D2-40 to assess tumor angiogenic potential, melanocytic activity, and lymphangiogenesis. The study was conducted with adherence to ethical standards and informed consent from all participants., Results: Dermatoscopic examination revealed a variety of vascular patterns and pigmented features across different BCC anatomical locations. However, the comprehensive correlation analysis predominantly found a lack of significant associations between dermatoscopic appearances and expressions of the targeted immunohistochemical markers, with the notable exception of a correlation between observed hemorrhage and the Melan-A marker., Conclusions: The lack of significant correlations between dermatoscopic features and immunohistochemical marker expressions in BCC suggests that the biological behavior and angiogenic, melanocytic, and lymphangiogenic activities within BCC lesions may be influenced by factors beyond those assessed in this study. Despite the exploratory nature of these findings, they underscore the complexity of BCC biology and highlight the need for further research incorporating additional markers and advanced imaging techniques., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Calik, Sauer, Giedziun, Piotrowska, Tumiłowicz, Wojnar and Dzięgiel.)

Synovitis is characterized by a distinctmetabolic profile featuring the accumulation of lactate, a byproduct of cellular metabolism within inflamed joints. This study reveals that the activation of the CD31 signal by lactate instigates a metabolic shift, specifically initiating endothelial cell autophagy. This adaptive process plays a pivotal role in fulfilling the augmented energy and biomolecule demands associated with the formation of new blood vessels in the synovium of Rheumatoid Arthritis (RA). Additionally, the amino acid substitutions in the CD31 cytoplasmic tail at the Y663F and Y686F sites of the immunoreceptor tyrosine-based inhibitory motifs (ITIM) alleviate RA. Mechanistically, this results in the downregulation of glycolysis and autophagy pathways. These findings significantly advance our understanding of potential therapeutic strategies for modulating these processes in synovitis and, potentially, other autoimmune diseases., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this article, (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Coronary collaterals are the feeding bridges between the main epicardial arteries, and research has shown that this collateral development plays a crucial role in myocardial performance, especially in patients with coronary artery disease. However, the evolution of these collaterals has not been fully explained., Objective: In this study, we aimed to reveal the effect of CD31 on coronary collateral development., Methods: As a result of coronary angiography performed in our clinic, 89 patients with coronary artery disease and 90 patients with normal coronary arteries were included in the study. Collateral development degrees were recorded from the angiographic images of the subjects. CD31 values were compared between the group with coronary artery disease and the control group. In addition, the coronary artery disease group was divided into subgroups according to the collateral development in terms of good collateral development and poor collateral development, and the factors that may affect the collateral development were tried to be determined., Results: CD31 levels were significantly higher in the group with coronary artery disease compared to the control group (p <0.001). In addition, CD31 levels in the subgroup with good collateral were significantly higher than in the group with weak collateral (p <0.001). In the correlation analysis, a significant positive correlation was found between serum CD31 level and SYNTAX score, age, glucose, and rentrop grade. Multivariate logistic regression analysis showed CD31 to be an independent predictor of good coronary collateral development., Conclusion: CD31, a marker of angiogenesis, may be involved in coronary collateral development., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Trichinosis spiralis is a global disease with significant economic impact. Albendazole is the current-treatment. Yet, the world-widely emerging antimicrobial resistance necessitates search for therapeutic substitutes. Curcumin is a natural compound with abundant therapeutic benefits. This study aimed to evaluate the potential of crude-curcumin, chitosan and for the first time curcumin-nano-emulsion and curcumin-loaded-chitosan-nanoparticles against Trichinella spiralis adults and larvae in acute and chronic trichinosis models. Trichinosis spiralis was induced in 96 Swiss-albino mice. Infected mice were divided into 2 groups. Group I constituted the acute model, where treatment started 2 h after infection for 5 successive days. Group II constituted the chronic model, where treatment started at the 30th day-post-infection and continued for 10 successive days (Refer to graphical abstract). Each group contained 8 subgroups that were designated Ia-Ih and IIa-IIh and included; a; Untreated-control, b; Albendazole-treated (Alb-treated), c; Crude-curcumin-treated (Cur-treated), d; Curcumin-nanoemulsion-treated (Cur-NE-treated), e; Albendazole and crude-curcumin-treated (Alb-Cur-treated), f; Albendazole and curcumin-nanoemulsion-treated (Alb-Cur-NE-treated), g; Chitosan-nanoparticles-treated (CS-NPs-treated) and h; Curcumin-loaded-chitosan-nanoparticles-treated (Cur-CS-NPs-treated). Additionally, six mice constituted control-uninfected group III. The effects of the used compounds on the parasite tegument, in-vivo parasitic load-worm burden, local pathology and MDA concentration in small intestines of acutely-infected and skeletal muscle of chronically-infected mice were studied. Results showed that albendazole was effective, yet, its combination with Cur-NE showed significant potentiation against adult worms and muscle larvae and alleviated the pathology in both models. Cur-CS-NPs exhibited promising results in both models. Crude-curcumin showed encouraging results especially against muscle larvae on long-term use. Treatments effectively reduced parasite load, local MDA level and CD31 expression with anti-inflammatory effect in intestine and muscle sections., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflicts of interest of a financial or personal nature., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The liver fluke Opisthorchis felineus is a foodborne zoonotic pathogen endemic to Russia, Kazakhstan, and several European countries. The adult flukes affect the hepatobiliary system of piscivorous mammals and humans, thereby causing numerous complications, including liver fibrosis. Detailing the mechanisms of progression of the fibrotic complications is a hot topic in the field of research on opisthorchiasis pathogenesis. Pathologic angiogenesis appears to be associated with the fibrogenic progression due to active participation in the recruitment of inflammatory cells and many factors involved in the modulation of the extracellular matrix. The aim of the study was to evaluate neoangiogenesis and amyloid deposits in liver tissues of model animals and patients with confirmed chronic opisthorchiasis. In addition, we assessed a possible correlation of neoangiogenesis with liver fibrosis. We found a significant increase in the number of newly formed vessels and amyloid deposits in the liver of people with chronic opisthorchiasis compared to that of uninfected ones. Thus, for the first time we have demonstrated neoangiogenesis and amyloid deposits during O. felineus infection in a Mesocricetus auratus model. Regression analysis showed that CD34 + newly formed vessels correlate with fibrosis severity in the course of the infection. Our results indicate the potential contribution of angiogenesis to the progression of liver fibrosis, associated with O. felineus infection., Competing Interests: Declaration of Competing Interest All the participants provided written informed consent., (Copyright © 2023. Published by Elsevier B.V.)

Background: Bone defects lead to dramatic changes in the quality of life. Acellular dermal matrix (ADM) and decellularized bone matrix (DBM) are natural scaffolds for tissue regeneration. The microcarrier scaffolds enable better vascularization and cell proliferation. This study compared the effect of microcarrier forms of DBM and ADM-loaded with adipose stem cells (ASCs) in the repair of compact bone defect in-vivo., Methods: Fifty-four male rats were divided into 4 groups; (i) Group (Gp) I: sham control; (ii) GpII: underwent femur bone defect induction and left to heal spontaneously; (iii) GpIII (ADM-Gp): included 2 subgroups; IIIa and IIIb: the bone defects were filled with non-loaded ADM and ADM-loaded with ASCs, respectively; (iv) GpIV (DBM-Gp): included 2 subgroups; IVa and IVb: the bone defects were filled with non-loaded DBM and DBM-loaded with ASCs, respectively. Animals were euthanized after 1, 2 and 3 months and their femur sections were stained with H&E, Masson's trichrome and immunohistochemistry for CD31, osteopontin and osteocalcin., Results: Histological analysis illustrated limited bone regeneration in the cortical defect of GpII after 3 months. The histomorphometric analysis showed significant delayed mature collagen deposition as well as CD31, osteopontin and osteocalcin expression. Superior capacity of new bone regeneration was detected with bio-scaffold micro-carriers; loaded or non-loaded with ASCs. However, DBM-loaded with ASCs displayed enhanced regeneration properties confirmed by the apparently normal architecture of the new bone and accelerated expression of CD31, osteopontin and osteocalcin in the regenerated bone after 3 months., Conclusions: We concluded that decellularized scaffolds significantly improved compact bone regeneration with superiority of ASCs seeded-bone scaffolds., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier GmbH. All rights reserved.)

Capillary density in skeletal muscles is key to estimate exercise capacity in healthy individuals, athletes, and those with muscle-related pathologies. Here, we present a step-by-step, high-throughput semi-automated method for quantifying capillary density from whole human skeletal muscle cross-sections, in areas of the muscle occupied by myofibers. We provide a detailed protocol for immunofluorescence staining, image acquisition, processing, and quantification. Image processing is performed in ImageJ, and data analysis is conducted in R. The provided protocol allows high-throughput quantification of capillary density. Key features • This protocol builds upon the method and results described in Abbassi-Daloii et al. (2023b). • It includes step-by-step details on image acquisition and image processing of the entire muscle section. • It enables high-throughput and semi-automated image quantification of capillary density. • It provides a robust analysis for determining capillary density over the entire muscle cross section., Competing Interests: Competing interestsAll authors declare no competing interests., (©Copyright : © 2024 The Authors; This is an open access article under the CC BY license.)

Introduction: Primary pleural epithelial angiosarcoma (EAS) is an extremely rare tumor with no specific clinical symptoms. Clinical data on primary pleural EAS are limited, and misdiagnosis often occurs., Case Presentation: The present study reports the case of a 31-year-old patient diagnosed with primary pleural EAS with lung and bone metastases. The patient presented with persistent right chest pain for 5 months and dyspnea for 2 months. Chest computed tomography (CT) scan revealed right hydropneumothorax, diffuse thickening of the right pleura, passive atelectasis, and scattered nodules in the left lung. A medical thoracoscopic pleural biopsy revealed a vasogenic tumor. To further confirm the diagnosis, positron emission tomography/CT (PET/CT) examination was recommended to determine the biopsy site after multidisciplinary discussion. Increased 18F-FDG uptake in the right pleura and hypermetabolic nodules in the right chest wall, first lumbar vertebrae, second sacral vertebrae, and bilateral iliac crest was detected via PET/CT. CT-guided chest wall and lung biopsies were performed. Immunohistochemistry of specific markers was performed according to remote consultation with a pathologist, and tumor cells with strong positive expression of CD31, CD34, and ETS-related genes led to the final diagnosis of primary pleural EAS., Conclusion: Primary pleural EAS should be considered for hydropneumothorax of an unknown cause. PET/CT can accurately locate the lesion. The pathological examination is the basis for primary pleural EAS diagnosis. Moreover, multidisciplinary discussion and remote expert consultation can improve the diagnosis rate of primary pleural EAS., Competing Interests: The authors report no conflict of interest., (© 2024 The Author(s). Published by S. Karger AG, Basel.)

Infantile hemangioma is a common benign vascular tumor in children, but it is very unusual to be found intracranially. Our literature review identified 44 reported cases. Presentation can vary from asymptomatic to a life-threatening presentation that necessitates urgent surgical removal. There is no general consensus on management of these rare lesions and until recently, treatment was limited to surgery or pharmacological management with steroids, propranolol or interferon. We present a case of a four-week-old male infant with history of vomiting and increase in head circumference since birth. MRI of the brain revealed a large complex cyst occupying the right frontoparietal region, with round soft tissue component that is isointense on T1 and hyperintense on T2 weighted images. Complete surgical resection with evacuation of the cyst was achieved. Histopathology of the mass showed infantile hemangioma with positive CD31 on immunohistochemistry. The patient achieved an excellent outcome following surgical resection., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Albalawi et al.)

Toxoplasma gondii causes a global parasitic disease. Therapeutic options for eradicating toxoplasmosis are limited. In this study, ZnO and Mg-doped ZnO NPs were prepared, and their structural and morphological chrematistics were investigated. The XRD pattern revealed that Mg-doped ZnO NPs have weak crystallinity and a small crystallite size. FTIR and XPS analyses confirmed the integration of Mg ions into the ZnO framework, producing the high-purity Mg-doped ZnO nanocomposite. TEM micrographs determined the particle size of un-doped ZnO in the range of 29 nm, reduced to 23 nm with Mg 2+ replacements. ZnO and Mg-doped ZnO NPs significantly decreased the number of brain cysts ( p < 0.05) by 29.30% and 35.08%, respectively, compared to the infected untreated group. The administration of ZnO and Mg-doped ZnO NPs revealed a marked histopathological improvement in the brain, liver, and spleen. Furthermore, ZnO and Mg-doped ZnO NPs reduced P53 expression in the cerebral tissue while inducing CD31 expression, which indicated a protective effect against the infection-induced apoptosis and the restoration of balance between free radicals and antioxidant defense activity. In conclusion, the study proved these nanoparticles have antiparasitic, antiapoptotic, and angiogenetic effects. Being nontoxic compounds, these nanoparticles could be promising adjuvants in treating chronic toxoplasmosis.

Introduction: Congenital diaphragmatic hernia (CDH) is a complex congenital disorder, characterized by pulmonary hypertension (PH) and hypoplasia. PH secondary to CDH (CDH-PH) features devastating morbidity and mortality (25-30%) among neonates. An unmet need is determining mechanisms triggering CDH-PH to save infants. Prior data suggest abnormal remodeling of the pulmonary vascular extracellular matrix (ECM), presumed to be driven by endothelial-to-mesenchymal transition (EndoMT), hinders postnatal vasodilation and limits anti-PH therapy in CDH. There are limited data on the role of EndoMT in CDH-PH., Methods: The purpose of the study was to investigate how EndoMT contributes to CDH-PH by identifying cells undergoing EndoMT noted by alpha smooth muscle actin (α-SMA) expression in human umbilical vein endothelial cells (HUVECs) and lung tissue obtained from murine pups using the nitrofen model. N = 8 CDH, N = 8 control HUVECs were stained for α-SMA and CD31 after being exposed for 24 h to TGFB, a known EndoMT promoter. N = 8 nitrofen, N = 8 control murine pup lungs were also stained for α-SMA and CD31. α-SMA and CD31 expression was quantified in HUVECs and murine tissue using Fiji imaging software and normalized to the total number of cells per slide noted by DAPI staining., Results: CDH HUVECs demonstrated a 1.1-fold increase in α-SMA expression (p = 0.02). The murine model did not show statistical significance between nitrofen and control pup lungs; however, there was a 0.4-fold increase in α-SMA expression with a 0.8-fold decrease in CD31 expression in the nitrofen pup lungs when compared to controls., Conclusion: These results suggest that EndoMT could potentially play a role in the ECM remodeling seen in CDH-PH., (© 2024 S. Karger AG, Basel.)

Trichinellosis is one of the global food-borne parasitic diseases that can cause severe tissue damage. The traditionally used drugs for the treatment of trichinellosis have limited efficacy against the encysted larvae in the muscular phase of the disease. Therefore, this study aimed to evaluate the role of atorvastatin and mesenchymal stem cells combined with ivermectin against different phases of Trichinella in experimentally infected mice. A total of 120 male Swiss albino mice were divided into two major groups (n = 60 of each), intestinal and muscular phases. Then, each group was subdivided into 10 subgroups (n = 6); non-infected control, infected non-treated control, infected ivermectin treated, infected atorvastatin treated, infected mesenchymal stem cells treated, infected combined ivermectin and atorvastatin treated, infected combined mesenchymal stem cells and ivermectin treated, infected combined mesenchymal stem cells and atorvastatin treated, infected combined mesenchymal stem cells and a full dose of (ivermectin and atorvastatin) treated, and infected combined mesenchymal stem cells and half dose of (ivermectin and atorvastatin) treated. Mice were sacrificed at days 5 and 35 post-infection for the intestinal and muscular phases, respectively. The assessment was performed through many parameters, including counting the adult intestinal worms and muscular encysted larvae, besides histopathological examination of the underlying tissues. Moreover, a biochemical assay for the inflammatory and oxidative stress marker levels was conducted. In addition, levels of immunohistochemical CD31 and VEGF gene expression as markers of angiogenesis during the muscular phase were investigated. The combined mesenchymal stem cells and atorvastatin added to ivermectin showed the highest significant reduction in adult worms and encysted larvae counts, the most noticeable improvement of the histopathological changes, the most potent anti-inflammatory (lowest level of IL-17) and anti-angiogenic (lowest expression of CD31 and VEGF) activities, and also revealed the highly effective one to relieve the oxidative stress (lowest level of SOD, GSH, and lipid peroxidase enzymes). These observed outcomes indicate that adding mesenchymal stem cells and atorvastatin to ivermectin synergistically potentiates its therapeutic efficacy and provides a promising candidate against trichinellosis., (© 2023. The Author(s).)

In order to demonstrate the intricate interconnection of pulmonary lymphatic vessels, blood vessels, and nerve fibers, the rat lung was selected as the target and sliced at the thickness of 100 μm for multiply immunofluorescence staining with lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1), alpha smooth muscle actin (α-SMA), phalloidin, cluster of differentiation 31 (CD31), and protein gene product 9.5 (PGP9.5) antibodies. Taking the advantages of the thicker tissue section and confocal microscopy, the labeled pulmonary lymphatic vessels, blood vessels, and nerve fibers were demonstrated in rather longer distance, which was more convenient to reconstruct a three-dimensional (3D) view for analyzing their spatial correlation in detail. It was clear that LYVE-1 + lymphatic vessels were widely distributed in pulmonary lobules and closely to the lobar bronchus. Through 3D reconstruction, it was also demonstrated that LYVE-1 + lymphatic vessels ran parallel to or around the α-SMA + venules, phalloidin + arterioles and CD31 + capillaries, with PGP9.5 + nerve fibers traversing alongside or wrapping around them, forming a lymphatic, vascular and neural network in the lung. By this study, we provide a detailed histological view to highlight the spatial correlation of pulmonary lymphatic, vascular and neural network, which may help us for insight into the functional role of this network under the physiological and pathological conditions., (© 2023. The Author(s), under exclusive licence to Springer Nature B.V.)

Introduction and Importance: Vertebral artery dissection is a rare but serious condition that can lead to neurological deficits and even death. It is commonly associated with trauma or underlying vascular diseases. Top of basilar syndrome (TOBS) is a neurological condition that can result from vertebral artery dissection, either by direct ischemia or secondary occlusion due to distal embolization of injured inner vascular tissue. We here present a patient who was initially suffering from seizure then had TOBS due to a progressive vertebral artery dissection, with emphasis of high-resolution MRI imaging and immunohistochemistry study of the thrombus., Case Presentation: A young male presented to the emergency department with sudden onset of seizure. A history of recent neck exercise was reported. The patient had gaze palsy, adduction disability, and dysarthria. High-resolution MRI showed a vertebral artery dissection with evidence of occlusion of the top of basilar artery. After the thrombectomy, a pathologic study revealed CD31[+] tissue in the thrombus, indicating an origin from dissected vertebral artery., Clinical Discussion and Conclusion: It's important to recognize and treat vertebral artery dissection promptly due to its varying symptoms. Using high-resolution MRI at early stage and conducting pathologic analysis of CD31 on the thrombus can assist in the diagnosis, potentially leading to more precise treatment plans and better outcomes for patients., Competing Interests: Conflict of interest statement The authors declare that there is no competing interest., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Age estimation of wounds in veterinary forensic investigations is based on the presence and amount of granulation tissue. However, accurate age assessment is challenging and new time-dependent markers are warranted to support and improve the current procedure. The objective of this study was to evaluate the expression of CD31-positive blood vessels and α-smooth muscle action (α-SMA)-positive myofibroblasts in granulation tissue in order to evaluate their value as markers for porcine wound age estimation in a veterinary forensic context. Immunohistochemical expression of CD31 and α-SMA in 14 experimental porcine skin wounds of different ages (4, 6, 8, 10, 18, 27 and 35 days) and 11 forensic porcine wound specimens (of unknown age) were evaluated. CD31-positive blood vessels and α-SMA-positive myofibroblasts were present in the granulation tissue in the experimental wounds at all time points. A significant decrease in the mean blood vessel counts was found in wounds aged 18, 27 and 35 days compared with wounds aged 6 days (P < 0.001), when assessing both the superficial and deep part of the wound bed. α-SMA expression was lower at 27 and 35 days post wounding compared with 6-18 days post wounding. Combined assessment of three parameters (mean blood vessel counts in the superficial and deep wound beds and α-SMA expression) could approximately specify the age of the wounds as either 6-18 days or ≥27 days. In two of the forensic cases a combination of the three parameters yielded results that were similar to the experimental wounds, indicating a wound age of 6-18 days or ≥27 days, respectively. In the remaining forensic cases a combination of the three parameters did not show the same expression pattern as in the experimental wounds. The results indicate that in some forensic cases the application of CD31 and α-SMA markers appeared to support the current procedure for porcine wound age estimation, but this must be combined with pathological characteristics., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Background: Long-term voice-abuse or sudden vocal fold microvascular disruption can lead to injury and subsequent repair/remodeling of the vocal fold mucosa. Periostin is known to be involved in airway remodeling and in various otolaryngological diseases. In ischemic heart disease, increased CD31 expression has been observed around cardiomyocytes during remodeling, and endothelial proliferation has been reported to occur at these sites., Objectives: We investigated the expression and the roles of CD31, CD34, and periostin in the formation of vocal fold polyps., Materials and Methods: Fifty-seven samples of vocal fold polyps were investigate histopathologically and immunohistochemically., Result: Expression of CD31 and CD34 was detected in 41 (71.9%) and 53 (93.0%) samples, respectively, obtained from patients with vocal fold polyp. Expression of periostin was detected in 41 (71.9%) samples obtained from patients with vocal polyps. The vocal polyp samples could be classified into three histological subtypes. Three patterns of CD31 and CD34 expression were observed in the vocal polyp. Four patterns of periostin expression were observed in vocal polyps. An association was observed between the CD31 expression pattern and the histological subtype of vocal fold polyps., Conclusion and Significance: In vocal fold polyps, evaluation of vascular endothelial markers may be useful for staging.

Wound healing is a complex and meticulously orchestrated process involving multiple phases and cellular interactions. This narrative review explores the intricate mechanisms behind wound healing, emphasizing the significance of cellular processes and molecular factors. The phases of wound healing are discussed, focusing on the roles of immune cells, growth factors, and extracellular matrix components. Cellular shape alterations driven by cytoskeletal modulation and the influence of the 'Formin' protein family are highlighted for their impact on wound healing processes. This review delves into the use of absorbable meshes in wound repair, discussing their categories and applications in different surgical scenarios. Interleukins (IL-2 and IL-6), CD31, CD34, platelet rich plasma (PRP), and adipose tissue-derived mesenchymal stem cells (ADSCs) are discussed in their respective roles in wound healing. The interactions between these factors and their potential synergies with absorbable meshes are explored, shedding light on how these combinations might enhance the healing process. Recent advances and challenges in the field are also presented, including insights into mesh integration, biocompatibility, infection prevention, and postoperative complications. This review underscores the importance of patient-specific factors and surgical techniques in optimizing mesh placement and healing outcomes. As wound healing remains a dynamic field, this narrative review provides a comprehensive overview of the current understanding and potential avenues for future research and clinical applications.

Effective neutrophil migration to sites of inflammation is crucial for host immunity. A coordinated cascade of steps allows intravascular leukocytes to counteract the shear stress, transmigrate through the endothelial layer, and move toward the extravascular, static environment. Those events are tightly orchestrated by integrins, but, while the molecular mechanisms leading to their activation have been characterized, the regulatory pathways promoting their detachment remain elusive. In light of this, it has long been known that platelet-endothelial cell adhesion molecule ( Pecam1 , also known as CD31) deficiency blocks leukocyte transmigration at the level of the outer vessel wall, yet the associated cellular defects are controversial. In this study, we combined an unbiased proteomic study with in vitro and in vivo single-cell tracking in mice to study the dynamics and role of CD31 during neutrophil migration. We found that CD31 localizes to the uropod of migrating neutrophils along with closed β 2 -integrin and is required for essential neutrophil actin/integrin polarization. Accordingly, the uropod of Pecam1 -/- neutrophils is unable to detach from the extracellular matrix, while antagonizing integrin binding to extracellular matrix components rescues this in vivo migratory defect. Conversely, we showed that sustaining CD31 co-signaling actively favors uropod detachment and effective migration of extravasated neutrophils to sites of inflammation in vivo. Altogether, our results suggest that CD31 acts as a molecular rheostat controlling integrin-mediated adhesion at the uropod of egressed neutrophils, thereby triggering their detachment from the outer vessel wall to reach the inflammatory sites., Competing Interests: FA, MC, RB, JH, EP, GE, JV, SB, VO, BH, ML, PM No competing interests declared, AN is an inventorn patents filed ("Improved CD31 peptides" PCT/EP2013/062806) related to the work presented in this manuscript. No other potential conflicts of interest relevant to this article exist, GC is an inventor on patents filed ("Improved CD31 peptides" PCT/EP2013/062806) related to the work presented in this manuscript. No other potential conflicts of interest relevant to this article exist, (© 2023, Andreata, Clément et al.)

Back pain (BP) due to degenerative disc disease (DDD) is a severe, often disabling condition. The aim of this study was to determine the association between the expression level of proinflammatory cytokines (IL-1β, IL-6, and IL-17), angiogenesis markers (VEGF-A and CD31) in intervertebral disc (IVD) tissue and IVD degeneration in young people with discogenic BP. In patients who underwent discectomy for a disc herniation, a clinical examination, magnetic resonance imaging of the lumbar spine, histological and immunohistochemical analyses of these factors in IVD were performed in comparison with the parameters of healthy group samples (controls). Histology image analysis of IVD fragments of the DDD group detected zones of inflammatory infiltration, combined with vascularization, the presence of granulation tissue and clusters of chondrocytes in the tissue of nucleus pulposus (NP). Statistically significant increased expression of IL-1β, IL-6, IL-17, VEGF-A and CD31 was evident in the samples of the DDD group compared with the controls, that showed a strong correlation with the histological disc degeneration stage. Our results denote an immunoinflammatory potential of chondrocytes and demonstrates their altered morphogenetic properties, also NP cells may trigger the angiogenesis.

Ovarian cancer is the fifth leading cause of cancer-related deaths in women and the most lethal gynecologic cancer. It is curable when discovered at an early stage, but usually remains asymptomatic until advanced stages. It is crucial to diagnose the disease before it metastasizes to distant organs for optimal patient management. Conventional transvaginal ultrasound imaging offers limited sensitivity and specificity in the ovarian cancer detection. With molecularly targeted ligands addressing targets, such as kinase insert domain receptor (KDR), attached to contrast microbubbles, ultrasound molecular imaging (USMI) can be used to detect, characterize and monitor ovarian cancer at a molecular level. In this article, the authors propose a standardized protocol is proposed for the accurate correlation between in- vivo transvaginal KDR-targeted USMI and ex vivo histology and immunohistochemistry in clinical translational studies. The detailed procedures of in vivo USMI and ex vivo immunohistochemistry are described for four molecular markers, CD31 and KDR with a focus on how to enable the accurate correlation between in vivo imaging findings and ex vivo expression of the molecular markers, even if not the entire tumor could can be imaged by USMI, which is not an uncommon scenario in clinical translational studies. This work aims to enhance the workflow and the accuracy of characterization of ovarian masses on transvaginal USMI using histology and immunohistochemistry as reference standards, which involves sonographers, radiologists, surgeons, and pathologists in a highly collaborative research effort of USMI in cancer., (© 2023 Wiley-VCH GmbH.)

Several studies have shown that an abnormal vascular-immunity link could increase Alzheimer's disease (AD) risk; however, the mechanism is unclear. CD31, also named platelet endothelial cell adhesion molecule (PECAM), is a surface membrane protein of both endothelial and immune cells and plays important roles in the interaction between the vascular and immune systems. In this review, we focus on research regarding CD31 biological actions in the pathological process that may contribute to AD based on the following rationales. First, endothelial, leukocyte and soluble forms of CD31 play multi-roles in regulating transendothelial migration, increasing blood-brain barrier (BBB) permeability and resulting in neuroinflammation. Second, CD31 expressed by endothelial and immune cells dynamically modulates numbers of signaling pathways, including Src family kinases, selected G proteins, and β-catenin which in turn affect cell-matrix and cell-cell attachment, activation, permeability, survival, and ultimately neuronal cell injury. In endothelia and immune cells, these diverse CD31-mediated pathways act as a critical regulator in the immunity-endothelia-brain axis, thereby mediating AD pathogenesis in ApoE4 carriers, which is the major genetic risk factor for AD. This evidence suggests a novel mechanism and potential drug target for CD31 in the background of genetic vulnerabilities and peripheral inflammation for AD development and progression.

Although bone marrow mesenchymal stem cells (BMSCs) might have therapeutic potency in ischemic stroke, the benefits are limited. The current study investigated the effects of BMSCs engineered to overexpress vascular endothelial growth factor (VEGF) on behavioral defects in a rat model of transient cerebral ischemia, which was induced by middle cerebral artery occlusion. VEGF-BMSCs or control grafts were injected into the left striatum of the infarcted hemisphere 24 hours after stroke. We found that compared with the stroke-only group and the vehicle- and BMSCs-control groups, the VEGF-BMSCs treated animals displayed the largest benefits, as evidenced by attenuated behavioral defects and smaller infarct volume 7 days after stroke. Additionally, VEGF-BMSCs greatly inhibited destruction of the blood-brain barrier, increased the regeneration of blood vessels in the region of ischemic penumbra, and reducedneuronal degeneration surrounding the infarct core. Further mechanistic studies showed that among all transplant groups, VEGF-BMSCs transplantation induced the highest level of brain-derived neurotrophic factor. These results suggest that BMSCs transplantation with vascular endothelial growth factor has the potential to treat ischemic stroke with better results than are currently available., Competing Interests: None

In porcine placenta, abnormal development of the placental vasculature leads to placental insufficiency. The aim of this study was to determine the mRNA expression of angiogenic growth factors and to determine the vascular characteristics in placenta at day 40 of pig gestation. Samples were collected from maternal-chorioallantoic interface (n = 21) for the measurement of mRNA expression of VEGFA, ANGPT1, ANGPT2, FGF2 and its receptors KDR, TEK, FGFR1IIIc, FGFR2IIIb respectively, and for immunohistochemistry analysis of CD31 and VEGFA. Immunohistochemical analysis of CD31 and VEGFA, morphometric measurement of blood vessels, high-resolution light microscopy and transmission electron microscopy were performed. Capillary area density, number of blood vessels and capillary area were significantly higher on the maternal side than on the fetal side (p < .05). The ultrastructural finding of blood vessels demonstrates close contact with the trophoblastic epithelium. The relative mRNA expression of VEGFA and its receptor KDR was higher compared with the other angiogenic genes. In conclusion, a high mRNA expression of VEGFA and its receptor KDR added to the immunohistochemical results suggest a potential role of these genes in this pathway associated with an increase in the density of the capillary area on the maternal side and a reduction in the hemotrophic diffusion distance at the interface for nutrient exchange., (© 2023 Wiley-VCH GmbH. Published by John Wiley & Sons Ltd.)

Background: Prostate-specific membrane antigen (PSMA) was first noticed in prostate cancer cells, thereafter, It has been found in the endothelial cells of neovasculature in a variety of tumors, but not in normal vascular endothelium, This specificity makes PSMA an ideal molecule for vascular targeting in Cancer theranostics (i.e., combined diagnostic and therapeutic)., Objectives: The objective of this study was to evaluate the immunohistochemical (IHC) expression of PSMA in the neovasculature (identified by CD 31) of high-grade gliomas (HGGs) and to Correlate PSMA IHC expression in HGGs with clinicopathological features, to detect its possible role in tumor angiogenesis, where PSMA can be used as a future diagnostic and therapeutic target., Materials and Methods: This retrospective study included a total of 69 archived, formalin-fixed, paraffin-embedded tissue blocks of HGGs, including 52 cases classified as WHO grade IV (75.4%) and 17 cases as WHO grade III (24.6%). The samples were immunohistochemically analyzed for PSMA expression (in both TMV and parenchymal tumor cells) which was assessed using the composite PSMA immunostaining score. A score (0) was considered negative while scores 1-7 were considered positive (1-4, 5-6, or 7; weak, moderate, or strong respectively)., Results: PSMA is expressed specifically and significantly in endothelial cells of tumor microvessels (TMV) of HGGs, A statistically significant relationship was detected between PSMA IHC expression in both TMV and in parenchymal tumor cells (TC) and various glioma subtypes (P-value < 0.05 and <0.001 respectively).  Positive PSMA immunostaining in TMV was detected in all anaplastic ependymoma cases and in near all cases of classic GB and GB with oligodendroglial features more than other subtypes, with P-value specifically for PSMA positivity/negativity in TMV statistically significant (0.022). While for Tumor cells, Positive PSMA immunostaining was detected in all anaplastic ependymoma, most anaplastic astrocytoma and classic GB cases in contrary to other variants, with P-value statistically extremely significant (< 0.001). Comparing PSMA IHC expression in TMV and its expression in TC, it was significantly expressed in TMV of 82.7% versus TC of 51.9% of grade IV cases. Likewise, in GB with oligodendroglial features and gliosarcoma, the majority of cases showed positive staining in their TMV [8/8 (100%), 9/13 (69.2%) respectively], and, the reverse occurs in tumor cells where the majority of cases did NOT show staining in the tumor cells for PSMA (5/8 (62.5%), 11/13 (84.6%) of cases respectively), which was statistically significant (P-value ≤ 0.05) besides the significant difference in the pattern of staining according to composite PSMA scoring (P-value ≤ 0.05)., Conclusion: PSMA has a possible role in tumor angiogenesis, therefore it might be considered a potential promising endothelial target for Cancer theranostics with PSMA-based agents, in addition, PSMA was expressed significantly in TC of HGGs, thus, it appears to be involved in biologic behavior, carcinogenesis and tumor progression.

Objective: Diffuse large B-cell lymphoma (DLBCL) is an aggressive B-cell non-Hodgkin's lymphoma. Invasive DLBCL cells are likely to metastasize into extranodal tissue (e.g., the central nervous system) that is difficult for chemotherapy drugs to penetrate, seriously affecting patient prognosis. The mechanism of DLBCL invasion remains unclear. This study investigated the association between invasiveness and platelet endothelial cell adhesion molecule-1 (CD31) in DLBCL., Methods: This study consisted of 40 newly diagnosed DLBCL patients. Differentially expressed genes and pathways in invasive DLBCL cells were identified using real-time polymerase chain reaction, western blotting, immunofluorescence, and immunohistochemical staining, RNA sequencing, and animal experiments. The effect of CD31-overexpressing DLBCL cells on the interactions between endothelial cells was determined using scanning electron microscopy. The interactions between CD8+ T cells and DLBCL cells were examined using xenograft models and single-cell RNA sequencing., Results: CD31 was upregulated in patients with multiple metastatic tumor foci compared to patients with a single tumor focus. CD31-overexpressing DLBCL cells formed more metastatic foci in mice and shortened mouse survival time. CD31 disrupted the tight junctions between endothelial cells of the blood-brain barrier by activating the osteopontin-epidermal growth factor receptor-tight junction protein 1/tight junction protein-2 axis through the protein kinase B (AKT) pathway, enabling DLBCL to enter the central nervous system to form central nervous system lymphoma. Furthermore, CD31-overexpressing DLBCL cells recruited CD31+ CD8+ T cells that failed to synthesize interferon-γ (INF-γ), tumor necrosis factor-α (TNF-α), and perforin via the activated mTOR pathway. Some target genes, such as those encoding S100 calcium-binding protein A4, macrophage-activating factor, and class I b-tubulin, may be used to treat this type of DLBCL surrounded by functionally suppressed CD31+ memory T cells., Conclusions: Our study suggests that DLBCL invasion is associated with CD31. The presence of CD31 in DLBCL lesions could represent a valuable target for treating central nervous system lymphoma and restoring CD8+ T-cell function., Competing Interests: None., (AJTR Copyright © 2023.)

Introdcution: Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are major causes of COVID-19 mortality. However, drug delivery to lung tissues is impeded by endothelial cell barriers, limiting the efficacy of existing treatments. A prompt and aggressive treatment strategy is therefore necessary., Methods: We assessed the ability of anti-CD31-ORI-NPs to penetrate endothelial cell barriers and specifically accumulate in lung tissues using an animal model. We also compared the efficacy of anti-CD31-ORI-NPs to that of free oridonin in ameliorating acute lung injury and evaluated the cytotoxicity of both treatments on endothelial cells., Results: Compared to free ORI, the amount of anti-CD31-ORI-NPs accumulated in lung tissues increase at least three times. Accordingly, anti-CD31-ORI-NPs improve the efficacy three times on suppressing IL-6 and TNF-a secretion, ROS production, eventually ameliorating acute lung injury in animal model. Importantly, anti-CD31-ORI-NPs significantly decrease the cytotoxicity at least two times than free oridonin on endothelial cells., Discussion: Our results from this study will not only offer a novel therapeutic strategy with high efficacy and low toxicity, but also provide the rational design of nanomaterials of a potential drug for acute lung injury therapy., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Zhao, Jin, Lei, Bai, Pan, Wang, Zhu, Tang, Guo, Cai and Li.)

Background: Sjögren's syndrome (SS) is an autoimmune disease hallmarked by infiltration and destruction of exocrine glands. Currently, there is no therapy that warrants full recovery of the affected tissues. Umbilical cord-derived multipotent stromal cells, microincapsulated in an endotoxin-free alginate gel (CpS-hUCMS), were shown to modulate the inflammatory activity of PBMCs in SS patients in vitro , through release of soluble factors (TGFβ1, IDO1, IL6, PGE2, VEGF). These observations led us to set up the present study, aimed at defining the in vitro effects of CpS-hUCMS on pro- and anti-inflammatory lymphocyte subsets involved in the pathogenesis of SS., Methods and Results: Peripheral blood mononuclear cells (PBMCs) upon collection from SS patients and matched healthy donors, were placed in co-culture with CpS-hUCMS for five days. Cellular proliferation and T- (Tang, Treg) and B- (Breg, CD19 + ) lymphocyte subsets were studied by flow cytometry, while Multiplex, Real-Time PCR, and Western Blotting techniques were employed for the analysis of transcriptome and secretome. IFNγ pre-treated hUCMS were assessed with a viability assay and Western Blotting analysis before co-culture. After five days co-culture, CpS-hUCMS induced multiple effects on PBMCs, with special regard to decrease of lymphocyte proliferation, increase of regulatory B cells and induction of an angiogenic T cell population with high expression of the surface marker CD31, that had never been described before in the literature., Conclusion: We preliminarily showed that CpS-hUCMS can influence multiple pro- and anti-inflammatory pathways that are deranged in SS. In particular, Breg raised and a new Tang phenothype CD3 + CD31 H CD184 + emerged. These results may considerably expand our knowledge on multipotent stromal cell properties and may open new therapeutic avenues for the management of this disease, by designing ad hoc clinical studies., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Montanucci, Bistoni, Antonucci, Pescara, Greco, Basta, Bartoloni, Gerli and Calafiore.)

Background & Objective: Lymphovascular tumoral invasion is a typical histopathological feature of gastric carcinomas and supports the recognition of high-risk patients for the recurrence. We aimed to study CD31 expression in diverse subtypes of gastric carcinomas and to show its association with the histopathologic findings of the carcinoma to assess the prognosis., Methods: This cross-sectional study was conducted on 40 established patients with gastric adenocarcinoma from radical gastrectomy. The patients were classified according to the pathology assessments. Tumoral tissues were assessed by immunohistochemical staining for CD31 expression. Malignant behavior was estimated by histopathological evaluations., Results: CD31 positivity was described in 23 (57.5%) of all evaluated patients. In assessment of CD31 expression and tumor features presented, no significant association between the CD31 expression and patients' age, sex, tumor site, size, grade and stage, subtypes of carcinoma, perineural invasion, and also lymphovascular invasion was found. ( P >0.05)., Conclusion: Lymphovascular invasion may make valuable additional evidence and may be useful to detect gastric carcinoma patients at high risk for recurrence, who could be candidates for more supplementary therapies. However, in our study, CD31 expression did not show any association with the aggressive histopathologic features of this tumor., Competing Interests: None.

Background: Hypoxia is a key driver of fibrosis and is associated with capillary rarefaction in humans., Objectives: Characterize capillary rarefaction in cats with chronic kidney disease (CKD)., Animals: Archival kidney tissue from 58 cats with CKD, 20 unaffected cats., Methods: Cross-sectional study of paraffin-embedded kidney tissue utilizing CD31 immunohistochemistry to highlight vascular structures. Consecutive high-power fields from the cortex (10) and corticomedullary junction (5) were digitally photographed. An observer counted and colored the capillary area. Image analysis was used to determine the capillary number, average capillary size, and average percent capillary area in the cortex and corticomedullary junction. Histologic scoring was performed by a pathologist masked to clinical data., Results: Percent capillary area (cortex) was significantly lower in CKD (median 3.2, range, 0.8-5.6) compared to unaffected cats (4.4, 1.8-7.0; P = <.001) and was negatively correlated with serum creatinine concentrations (r = -.36, P = .0013), glomerulosclerosis (r = -0.39, P = <.001), inflammation (r = -.30, P = .009), and fibrosis (r = -.30, P = .007). Capillary size (cortex) was significantly lower in CKD cats (2591 pixels, 1184-7289) compared to unaffected cats (4523 pixels, 1801-7618; P = <.001) and was negatively correlated with serum creatinine concentrations (r = -.40, P = <.001), glomerulosclerosis (r = -.44, P < .001), inflammation (r = -.42, P = <.001), and fibrosis (r = -.38, P = <.001)., Conclusions and Clinical Importance: Capillary rarefaction (decrease in capillary size and percent capillary area) is present in kidneys of cats with CKD and is positively correlated with renal dysfunction and histopathologic lesions., (© 2023 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

Hepatic epithelioid hemangioendothelioma (HEHE) is an extremely uncommon tumor of the liver. It typically lacks recognizable clinical signs and is diagnosed with the aid of imaging and histopathology combined with immunohistochemical analysis. We discuss the case of a 40-year-old woman with HEHE. The aim of this case report and literature review is to increase doctors' knowledge of HEHE and reduce the incidence of missed clinical diagnoses., (© 2023 The Authors. Published by Elsevier Inc. on behalf of University of Washington.)

Background: The presence of lymph-vascular space invasion is a powerful predictor of lymph node metastasis. However, most studies do not distinguish lymph vessel invasion (LVI) and blood vessel invasion (BVI). The aim of this study was to distinguish the role of LVI and BVI in lymphatic metastasis and recurrence in patients with endometrial cancer., Methods: We examined 171 patients with endometrial cancer. Immunohistochemical double staining was used to distinguish lymphatic invasion and vascular invasion. First, the relationship between lymphatic/vascular invasion and clinicopathological features and lymphatic metastasis was studied. Then, the expression of D2-40/LVI and CD31/BVI in patients with recurrence was analyzed., Results: Pathological grading (G3) and D2-40/LVI were independent high-risk factors for lymph node metastasis of endometrial cancer. The area under the receiver operating characteristic curve values for predicting lymphatic metastasis using pathological grading (G3) or D2-40/LVI alone were .642 and .680, respectively, and the area under the curve value for the combined detection of pathological grading (G3) and D2-40/LVI was .726, which was greater than the values obtained for the abovementioned independent variables. Among the 15 recurrent patients, 5 (33.3%) were D2-40/LVI positive, 2 (13.3%) were CD31/BVI positive, and 8 (53.3%) were both D2-40/LVI and CD31/BVI positive., Conclusion: D2-40/LVI combined with G3 can effectively predict lymph node metastasis of endometrial carcinoma., Competing Interests: The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: All authors have completed the ICMJE uniform disclosure form. The authors declare that they have no financial and personal relationships with other people or organizations that can inappropriately influence their work. There is no professional or other personal interest of any nature or kind in any product, service, and/or company that could be construed as influencing the position presented in, or the review of, the manuscript entitled., (© The Author(s) 2023.)

Background: ABO antigens expressed on the red blood cells (RBCs) are not identical to those expressed on the renal endothelial cells. The isohemagglutinin assay employing the RBCs is the gold standard for evaluating anti-ABO antibody (Ab) levels. However, it remains unclear whether the anti-ABO Abs detected by the isohemagglutinin assay after ABO-incompatible (ABOi) kidney transplantations (KTx) that are not associated with antibody-mediated rejection can bind to renal graft endothelial cells., Methods: Ninety plasma samples were collected from patients with stable graft function after ABO-compatible (ABOc) or ABOi KTx. Anti-ABO Ab titers were examined by both the isohemagglutinin assay and the CD31-ABO microarray, which was developed as a mimic of the ABO antigens expressed on the renal endothelial cells., Results: The antibody titers detected by the isohemagglutinin assay and the CD31-ABO microarray after the ABOc KTx relatively correlated with each other. However, the CD31-ABO microarray results showed low antibody levels against donor blood group antigens after ABOi KTx and did not correlate with the isohemagglutinin assay. In contrast, the antibody levels against non-donor blood group antigens after ABOi KTx were comparable to those after the ABOc KTx. Fourteen patients received graft biopsies, and no antibody-mediated rejection was observed in ABOi KTx recipients, except for two patients who had anti-donor-HLA Abs., Conclusion: The present study suggested that the anti-ABO Abs detected by the isohemagglutinin assay after ABOi KTx with stable graft function were hyporeactive to the ABO antigen of graft renal endothelial cells., (© 2022. The Author(s), under exclusive licence to The Japanese Society of Nephrology.)

Background: Neovascularization is essential for the growth and progression of tumor tissues. GRP78 is frequently overexpressed in various cancers and has been suggested as a proangiogenic factor., Purpose: This study aimed to investigate the expression levels of GRP78 and to test for significant relationships with the angiogenic markers, VEGF, and CD31., Methods: In this study, paraffin-embedded NSCLC tissue samples (71 adenocarcinomas and 23 squamous cell carcinoma) were retrospectively collected from 94 patients with NSCLC. The expressions of VEGF, CD31, and GRP78 were determined by immunohistochemistry., Results: High expression levels of VEGF and GRP78 were observed in 65 and 74 cases, respectively. Thirty-six patients expressed high CD31 levels. Adenocarcinomas expressed higher levels of the three proteins than squamous cell carcinomas (p-value < 0.05). Moreover, a statistically significant association was found between the expression levels of VEGF and CD31 (p-value = 0.001) and VEGF and GRP78 (p-value=0.028)., Conclusion: GRP78 overexpression was revealed in most of the investigated samples. The positive association between VEGF and GRP78 may indicate the proangiogenic role of GRP78 in lung cancer. Moreover, the positive association between VEGF and CD31 expression levels suggests that VEGF may cooperate with CD31 to promote angiogenesis in NSCLC., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Meningioma is the most common intracranial neoplasm, yet there is no effective therapy for recurrent/refractory meningiomas after surgery and radiation. Prostate-specific membrane antigen (PSMA) is an enzyme upregulated on endothelial cells of multiple neoplasms and is being investigated as a theranostic target. Until now, PSMA has not been studied in meningiomas. We aimed to verify PSMA endothelial expression in meningiomas, detect tumor grade variability, and investigate the relationship of PSMA signal with tumor recurrence. We analyzed 96 archival meningiomas including 58 de novo and 38 recurrent specimens. All specimens were stained routinely and immunostained for CD31 and PSMA. Slides were scanned and analyzed producing raw data for images of PSMA, CD31, PSMA/CD31, and PSMA/vasculature. PSMA expression was seen within 98.9% of meningioma samples. In the total cohort, higher-grade tumors had increased expression of raw PSMA and PSMA/CD31, and PSMA/vasculature ratios compared to grade 1 tumors. PSMA expression and PSMA/vasculature ratios (p = 0.0015) were higher in recurrent versus de novo tumors among paired samples. ROC curves demonstrated PSMA/CD31, PSMA/vasculature, and raw CD31 as indicators of tumor recurrence. Thus, PSMA is expressed within endothelial cells of meningiomas, is increased with tumor grade and recurrence, and persists with prior irradiation., (© The Author(s) 2022. Published by Oxford University Press on behalf of American Association of Neuropathologists, Inc.)

Our study was to pinpoint the significance of histone deacetylase 5 (HDAC5) affecting the pathogenesis of preeclampsia (PE) via CD31/mammalian target of rapamycin (mTOR) axis by regulating cysteine-rich angiogenic inducer 61 (CYR61). Expression of HDAC5, CYR61, and CD31/mTOR in placental tissues of patients with PE and trophoblast cells HTR-8/SVneo cells was determined first followed by their interaction analysis. Following different transfection, the significance of HDAC5 in cell functions was assayed in relation to CYR61 and CD31/mTOR. An in vivo PE mouse model was constructed for further validation. The clinical tissue and in vitro cell experimentations discovered that HDAC5 was downregulated in placental tissues of PE patients and trophoblast cells, while CYR61, CD31, mTOR, and p-mTOR displayed upregulation. After overexpression of HDAC5, trophoblast cell functions were enhanced. HDAC5 reduced the acetylation enrichment of H3K27 to inhibit the expression of CYR61. Furthermore, CYR61 promoted the activation of CD31/mTOR axis, thereby inhibiting HTR-8/SVneo cell functions. The in vivo rat model confirmed the above alterations. Taken together, HDAC5 contributes to downregulation of CYR61 through histone deacetylation, inactivating CD31/mTOR axis, which prevents the occurrence and development of PE., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

CD31, a transmembrane protein expressed on endothelial and hematopoietic cells, plays important roles in leukocyte trafficking, mechanotransduction, angiogenesis, vascular permeability, and regulation of cellular responsiveness. CD31 immunoreactivity is employed as a sensitive and specific endothelial marker in diagnostic pathology. In this study, CD31 expression in myocardial tissues from deceased patients with ischemic heart disease and a mouse model of acute myocardial infarction were examined by immunohistochemical staining. We examined 24 neutral formalin-fixed, paraffin-embedded myocardial tissue samples obtained within 48 h postmortem from the autopsies of patients who were diagnosed with ischemic heart disease. CD31 expression was observed in vascular endothelial and endocardial cells. In necrotic myocardium, diffusion of CD31 antigen was observed. Elevated CD31 expression was observed around myocardial cells undergoing remodeling, suggesting that endothelial proliferation occurred at these sites. In contrast, fibrotic myocardial foci did not show upregulated CD31 expression. The same CD31 expression characteristics as those observed in the human samples were observed in the mouse model. CD31 immunostaining as an endothelial and microvasculature marker may be a useful complement to conventional staining techniques currently used in the diagnosis of ischemic heart disease, and may allow the timing and process of myocardial remodeling to be analyzed in detail., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)