Sandra Bargiela-Cuevas, María Marin, María Gabaldon-Ojeda, José I Klett-Mingo, Paula Granado, Silvia Sacristan, Alfonso Esteban-Lasso, José G Casas, María E Martin, Victor M M González, Mar Royuela, Ignacio García-Tuñon, Miguel Angel Ortega Núñez, María Del Val Toledo Lobo
{"title":"Histone Acetyl Transferase 1 Is Overexpressed in Poor Prognosis, High-grade Meningeal and Glial Brain Cancers: Immunohistochemical and Aptahistochemical Study.","authors":"Sandra Bargiela-Cuevas, María Marin, María Gabaldon-Ojeda, José I Klett-Mingo, Paula Granado, Silvia Sacristan, Alfonso Esteban-Lasso, José G Casas, María E Martin, Victor M M González, Mar Royuela, Ignacio García-Tuñon, Miguel Angel Ortega Núñez, María Del Val Toledo Lobo","doi":"10.1369/00221554241272341","DOIUrl":"10.1369/00221554241272341","url":null,"abstract":"<p><p>Primary malignancies of the central nervous system account for 2% of all cancers in adults and almost 15% in children under 15 years of age. The prognosis of brain anaplastic cancers and glioblastomas remains extremely poor, with devastating survival expectative, and new molecular markers and therapeutic targets are essential. Epigenetic changes constitute an extensive field for the development of new diagnostic and therapeutic strategies. Histone acetyl transferase-1 (HAT1) has merged as a potential prognostic marker and therapy target for different malignancies. Data repository analysis showed HAT1 mRNA overexpression in gliomas and has been described its alternative splicing in glioblastomas. Using immunohistochemical and aptahistochemical methods, we analyzed the expression of HAT1 in meningiomas, oligodendrogliomas, and astroglial cancers. We observed that HAT1 overexpression is associated with the most aggressive tumor types and the worse prognosis, as well as with a higher probability of early relapse in meningiomas. Its cytosolic localization correlates with tumor progression and prognosis. Aptamers, synthetic oligonucleotides capable to bind and inhibit a wide variety of targets, are considered as promising diagnostic and therapeutic tools. Aptahistochemistry using the aptamer apHAT610 offered superior results in comparison with the antibody used, as a good example of the potential of aptamers as diagnostic tools for histopathology.</p>","PeriodicalId":16079,"journal":{"name":"Journal of Histochemistry & Cytochemistry","volume":" ","pages":"585-599"},"PeriodicalIF":1.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11423361/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142046756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Akifumi Muramoto, Hitomi Hoshino, So Inamura, Masataka Murahashi, Tomoya O Akama, Naoki Terada, Motohiro Kobayashi
{"title":"Expression of Podocalyxin Potentially Decorated With Low-sulfated Keratan Sulfate in Human Testicular Embryonal Carcinoma.","authors":"Akifumi Muramoto, Hitomi Hoshino, So Inamura, Masataka Murahashi, Tomoya O Akama, Naoki Terada, Motohiro Kobayashi","doi":"10.1369/00221554241265162","DOIUrl":"10.1369/00221554241265162","url":null,"abstract":"<p><p>We previously demonstrated that among various histological types of human testicular germinal cell tumors (GCTs), embryonal carcinoma (EC) preferentially expresses low-sulfated keratan sulfate (KS) consisting of repeating <i>N</i>-acetyllactosamine (LacNAc) disaccharide units composed of galactose and 6-<i>O</i>-sulfated <i>N</i>-acetylglucosamine (GlcNAc), which is recognized by the R-10G antibody. Recently, we generated another anti-low-sulfated KS monoclonal antibody, 294-1B1. Immunohistochemical analysis of testicular GCTs (<i>n</i>=83) revealed that the low-sulfated KS recognized by 294-1B1 is also preferentially expressed in EC but minimally in other GCT histological types. Moreover, immunolabeling with R-10G and 294-1B1 antibodies was resistant to peptide-<i>N</i>-glycosidase F digestion, and EC was not stained with the MECA-79 antibody, indicating that low-sulfated KS expressed in EC contains mucin-type core 2 <i>O</i>-glycans carrying GlcNAc-6-<i>O</i>-sulfated oligo-LacNAc. Double immunofluorescence staining showed that R-10G and 294-1B1 antibody signals colocalized with those for podocalyxin (PODXL). Furthermore, western blot analysis of recombinant human PODXL•IgG fusion proteins secreted from low-sulfated KS-expressing human embryonic kidney 293T cells revealed that PODXL functions as a core protein for low-sulfated KS. Taken together, these findings strongly suggest that the PODXL glycoform decorated with low-sulfated KS is preferentially expressed in human testicular EC and may therefore serve as a diagnostic marker for this malignancy.</p>","PeriodicalId":16079,"journal":{"name":"Journal of Histochemistry & Cytochemistry","volume":" ","pages":"453-465"},"PeriodicalIF":1.9,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11308194/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141759153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anna-Sophia Liselott Beyer, Daniel Kaemmerer, Jörg Sänger, Amelie Lupp
{"title":"Expression of FAM159B in Humans, Rats, and Mice: A Cross-species Examination.","authors":"Anna-Sophia Liselott Beyer, Daniel Kaemmerer, Jörg Sänger, Amelie Lupp","doi":"10.1369/00221554241262368","DOIUrl":"10.1369/00221554241262368","url":null,"abstract":"<p><p>Little is known about the adaptor protein FAM159B. To determine whether FAM159B expression findings in rats or mice can be extrapolated to humans, we compared FAM159B expression in healthy tissue samples from all three species using immunohistochemistry. Despite variations in expression intensity, similar FAM159B expression patterns were observed in most organs across species. The most prominent species difference was noted in pancreatic islets; while FAM159B expression was limited to single cells on the outer edges in mice and rats, it was detectable across entire islets in humans. Double-labeling immunohistochemistry revealed partial overlap of FAM159B expression with that of insulin, glucagon, and somatostatin in human islets. By contrast, FAM159B showed complete colocalization with only somatostatin in rats and mice. An additional analysis of FAM159B expression in lean and obese Zucker rats revealed larger islet areas due to increased β-cell mass in obese rats, which was accompanied by a smaller percentage of FAM159B-positive δ-cells per islet area. Beyond the known differences in islet architecture across species, our results point to larger dissimilarities in blood glucose regulation between rodents and humans than generally assumed. Moreover, findings regarding FAM159B expression (and function) cannot be directly transferred between rodents and humans.</p>","PeriodicalId":16079,"journal":{"name":"Journal of Histochemistry & Cytochemistry","volume":" ","pages":"467-487"},"PeriodicalIF":1.9,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11308193/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141440574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
David Bächinger, Jennifer T O'Malley, Morris Wolf, Stephane Bérnhard, M Charles Liberman, Mark W Tibbitt, Andreas H Eckhard
{"title":"Poly(Ethylene Glycols) to Facilitate Celloidin Removal for Immunohistochemical Studies on Archival Human Brain and Temporal Bone Sections.","authors":"David Bächinger, Jennifer T O'Malley, Morris Wolf, Stephane Bérnhard, M Charles Liberman, Mark W Tibbitt, Andreas H Eckhard","doi":"10.1369/00221554241266287","DOIUrl":"10.1369/00221554241266287","url":null,"abstract":"<p><p>Pathology repositories worldwide store millions of celloidin-processed human brain and temporal bone (TB) sections vital for studying central nervous system diseases and sensory organs. However, accessing these sections for modern molecular-pathological research, like immunohistochemistry, is hindered by the challenge of removing celloidin without damaging tissue. In this study, we explored the use of polyethylene glycols (PEGs), a class of non-hazardous, ethylene glycol oligomers, combined with an improved section mounting technique, to gently and effectively dissolve celloidin from sections archived for up to 40 years. Optimizing our protocol involved exploring celloidin dissolution kinetics in PEGs of varying molecular weights and terminations, as well as different temperatures. Low molecular weight PEGs, particularly PEG 200, were the most efficient celloidin solvent. Nuclear magnetic resonance (NMR) spectroscopy of celloidin-PEG 200 dissolution products revealed no chemical alterations, suggesting pure solvation without chemical modification. Because the solvation of celloidin in PEG was inhibited by proteins, we further developed a protein-free mounting protocol allowing complete celloidin removal in 30 to 60 minutes by immersing in PEG 200. In summary, our approach overcomes major methodological hurdles, rendering decades-old archival celloidin sections viable for immunohistochemical and other molecular biological techniques, while enhancing safety and workflow efficiency.</p>","PeriodicalId":16079,"journal":{"name":"Journal of Histochemistry & Cytochemistry","volume":" ","pages":"419-433"},"PeriodicalIF":1.9,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11308191/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141759154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"High-molecular-weight Hyaluronan Administration Inhibits Bone Resorption and Promotes Bone Formation in Young-age Osteoporosis Rats.","authors":"Toshiyuki Kikuchi, Kazuhiko Udagawa, Yoshihiro Sasazaki","doi":"10.1369/00221554241255724","DOIUrl":"10.1369/00221554241255724","url":null,"abstract":"<p><p>Osteoporosis poses a significant global health concern, affecting both the elderly and young individuals, including athletes. Despite the development of numerous antiosteoporotic drugs, addressing the unique needs of young osteoporosis patients remains challenging. This study focuses on young rats subjected to ovariectomy (OVX) to explore the impact of high-molecular-weight hyaluronan (HA) on preventing OVX-induced osteoporosis. Twenty-four rats underwent OVX, while 12 underwent sham procedures (sham control group). Among the OVX rats, half received subcutaneous injections of HA (MW: 2700 kDa) at 10 mg/kg/week into their backs (OVX-HA group), whereas the other half received saline injections (0.5 ml/week) at the same site (OVX-saline group). OVX-HA group exhibited significantly higher percentages of osteoclast surface (Oc. S/BS), osteoblast surface per bone surface (Ob. S/BS), and bone volume/tissue volume (BV/TV) compared with OVX-saline group at the same age. The proportions of Ob. S/BS and BV/TV in the OVX-HA group closely resembled those of the sham control group, whereas the proportion of Oc. S/BS in the OVX-HA group was notably higher than that in the sham control group. In summary, the administration of HA significantly mitigated bone resorption and enhanced bone formation, suggesting a crucial role for HA in the treatment of young adult osteoporosis.</p>","PeriodicalId":16079,"journal":{"name":"Journal of Histochemistry & Cytochemistry","volume":" ","pages":"373-385"},"PeriodicalIF":1.9,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11179592/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141158030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"DCM-Spheroid Morphs Express PADs and Citrullinated Cytoskeletal Proteins.","authors":"Alia Sadiq, Justyna Fert-Bober","doi":"10.1369/00221554241252862","DOIUrl":"10.1369/00221554241252862","url":null,"abstract":"<p><p>During investigating the role of peptidylarginine deiminase (PAD) enzymes in dilated cardiomyopathy (DCM), we observed unique spheroid formation in DCM-myofibroblasts that distinguished them from normal cardiac myofibroblasts. The present study aimed to assess the presence of PADs, the extracellular matrix (ECM), and citrullination in DCM spheroids using immunofluorescence staining and imaging techniques. The results revealed that spheroids derived from DCM-myofibroblasts displayed a more distinctive, tightly packed structure compared with those derived from human cardiac fibroblasts. DCM spheroids showed abundant protein expression of the PAD 2, 3, and 4 enzymes. Notably, increased Ki67 protein expression was associated with increased proliferation in DCM spheroids. Cytoskeletal proteins such as Col-1A, vimentin, α-SMA, and F-actin were highly abundant in DCM spheroids. Furthermore, DCM spheroids contained citrullinated cytoskeletal proteins, mainly citrullinated vimentin and citrullinated fibronectin. These observations supported the occurrence of PAD-mediated citrullination of ECM proteins in DCM spheroids. Collectively, these findings describe the distinctive features of DCM spheroids, representing the cellular characteristics of DCM myofibroblasts. Therefore, DCM spheroids can serve as an in vitro model for further investigations of disease morphology and therapeutic efficacy.</p>","PeriodicalId":16079,"journal":{"name":"Journal of Histochemistry & Cytochemistry","volume":" ","pages":"387-397"},"PeriodicalIF":1.9,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11179590/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140945132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Immunohistochemical Expression and Clinical Significance of WWP1 Protein in Nasopharyngeal Cancer.","authors":"Huarong Chen, Changya Li, Shengmei He, Junjun Ling, Houyu Zhao, Xianlu Zhuo","doi":"10.1369/00221554241255722","DOIUrl":"10.1369/00221554241255722","url":null,"abstract":"<p><p>Nasopharyngeal carcinoma (NPC) is a common malignant tumor of the head and neck. Its pathogenesis is complicated and needs further investigation. The aim of this study was to investigate the expression and clinical significance of WWP1 in NPC. Bioinformatics approaches were used to evaluate the expression and functions of WWP1 in NPC. WWP1 protein expression was then detected by immunohistochemistry on a tissue microarray in an NPC cohort and its association with clinical features and prognosis was determined. In addition, WWP1 expression was knocked down in NPC cells using RNA interference, and their colony formation and invasion abilities were assessed. A total of 25 genes closely related to WWP1, which may be enriched in different pathways, were filtered out. WWP1 expression was significantly higher in NPC cells than in normal controls. High WWP1 expression was correlated with lymph node metastasis, tumor recurrence, clinical stage and poor prognosis. Knockdown of WWP1 resulted in attenuated proliferation and invasion of NPC cells. The results suggest that WWP1 may serve as a novel biomarker and prognostic factor for NPC and a potential therapeutic target worthy of further investigation.</p>","PeriodicalId":16079,"journal":{"name":"Journal of Histochemistry & Cytochemistry","volume":" ","pages":"363-371"},"PeriodicalIF":1.9,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11179591/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141158087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sandra Cabrera, Ángeles García-Vicente, Pamela Gutiérrez, Andrea Sánchez, Miguel Gaxiola, Carolina Rodríguez-Bobadilla, Moisés Selman, Annie Pardo
{"title":"Increased ER Stress and Unfolded Protein Response Activation in Epithelial and Inflammatory Cells in Hypersensitivity Pneumonitis.","authors":"Sandra Cabrera, Ángeles García-Vicente, Pamela Gutiérrez, Andrea Sánchez, Miguel Gaxiola, Carolina Rodríguez-Bobadilla, Moisés Selman, Annie Pardo","doi":"10.1369/00221554241251915","DOIUrl":"10.1369/00221554241251915","url":null,"abstract":"<p><p>Several types of cytotoxic insults disrupt endoplasmic reticulum (ER) homeostasis, cause ER stress, and activate the unfolded protein response (UPR). The role of ER stress and UPR activation in hypersensitivity pneumonitis (HP) has not been described. HP is an immune-mediated interstitial lung disease that develops following repeated inhalation of various antigens in susceptible and sensitized individuals. The aim of this study was to investigate the lung expression and localization of the key effectors of the UPR, BiP/GRP78, CHOP, and sXBP1 in HP patients compared with control subjects. Furthermore, we developed a mouse model of HP to determine whether ER stress and UPR pathway are induced during this pathogenesis. In human control lungs, we observed weak positive staining for BiP in some epithelial cells and macrophages, while sXBP1 and CHOP were negative. Conversely, strong BiP, sXBP1- and CHOP-positive alveolar and bronchial epithelial, and inflammatory cells were identified in HP lungs. We also found apoptosis and autophagy markers colocalization with UPR proteins in HP lungs. Similar results were obtained in lungs from an HP mouse model. Our findings suggest that the UPR pathway is associated with the pathogenesis of HP.</p>","PeriodicalId":16079,"journal":{"name":"Journal of Histochemistry & Cytochemistry","volume":" ","pages":"289-307"},"PeriodicalIF":3.2,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11107439/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140896066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cornelis J F van Noorden, Bahar Yetkin-Arik, Paola Serrano Martinez, Noëlle Bakker, Mathilda E van Breest Smallenburg, Reinier O Schlingemann, Ingeborg Klaassen, Bernarda Majc, Anamarija Habic, Urban Bogataj, S Katrin Galun, Milos Vittori, Mateja Erdani Kreft, Metka Novak, Barbara Breznik, Vashendriya V V Hira
{"title":"New Insights in ATP Synthesis as Therapeutic Target in Cancer and Angiogenic Ocular Diseases.","authors":"Cornelis J F van Noorden, Bahar Yetkin-Arik, Paola Serrano Martinez, Noëlle Bakker, Mathilda E van Breest Smallenburg, Reinier O Schlingemann, Ingeborg Klaassen, Bernarda Majc, Anamarija Habic, Urban Bogataj, S Katrin Galun, Milos Vittori, Mateja Erdani Kreft, Metka Novak, Barbara Breznik, Vashendriya V V Hira","doi":"10.1369/00221554241249515","DOIUrl":"10.1369/00221554241249515","url":null,"abstract":"<p><p>Lactate and ATP formation by aerobic glycolysis, the Warburg effect, is considered a hallmark of cancer. During angiogenesis in non-cancerous tissue, proliferating stalk endothelial cells (ECs) also produce lactate and ATP by aerobic glycolysis. In fact, all proliferating cells, both non-cancer and cancer cells, need lactate for the biosynthesis of building blocks for cell growth and tissue expansion. Moreover, both non-proliferating cancer stem cells in tumors and leader tip ECs during angiogenesis rely on glycolysis for pyruvate production, which is used for ATP synthesis in mitochondria through oxidative phosphorylation (OXPHOS). Therefore, aerobic glycolysis is not a specific hallmark of cancer but rather a hallmark of proliferating cells and limits its utility in cancer therapy. However, local treatment of angiogenic eye conditions with inhibitors of glycolysis may be a safe therapeutic option that warrants experimental investigation. Most types of cells in the eye such as photoreceptors and pericytes use OXPHOS for ATP production, whereas proliferating angiogenic stalk ECs rely on glycolysis for lactate and ATP production. <b>(J Histochem Cytochem XX.XXX-XXX, XXXX)</b>.</p>","PeriodicalId":16079,"journal":{"name":"Journal of Histochemistry & Cytochemistry","volume":" ","pages":"329-352"},"PeriodicalIF":3.2,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11107438/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140908910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Immunohistochemical and Morphometric Assessment on the Biological Function and Vascular Endothelial Cells in the Initial Process of Cortical Porosity in Mice With PTH Administration.","authors":"Miki Abe, Tomoka Hasegawa, Hiromi Hongo, Tomomaya Yamamoto, Yan Shi, Jiaxin Cui, Xuanyu Liu, Qi Yao, Hotaka Ishizu, Haruhi Maruoka, Hirona Yoshino, Mai Haraguchi-Kitakamae, Tomohiro Shimizu, Norio Amizuka","doi":"10.1369/00221554241247883","DOIUrl":"10.1369/00221554241247883","url":null,"abstract":"<p><p>To clarify the cellular mechanism of cortical porosity induced by intermittent parathyroid hormone (PTH) administration, we examined the femoral cortical bone of mice that received 40 µg/kg/day (four times a day) human PTH (hPTH) (1-34). The PTH-driven cortical porosity initiated from the metaphyseal region and chronologically expanded toward the diaphysis. Alkaline phosphatase (ALP)-positive osteoblasts in the control mice covered the cortical surface, and endomucin-positive blood vessels were distant from these osteoblasts. In PTH-administered mice, endomucin-reactive blood vessels with TRAP-positive penetrated the ALP-positive osteoblast layer, invading the cortical bone. Statistically, the distance between endomucin-positive blood vessels and the cortical bone surface abated after PTH administration. Transmission electron microscopic observation demonstrated that vascular endothelial cells often pass through the flattened osteoblast layer and accompanied osteoclasts in the deep region of the cortical bone. The cell layers covering mature osteoblasts thickened with PTH administration and exhibited ALP, α-smooth muscle actin (αSMA), vascular cell adhesion molecule-1 (VCAM1), and receptor activator of NF-κB ligand (RANKL). Within these cell layers, osteoclasts were found near endomucin-reactive blood vessels. In PTH-administered femora, osteocytes secreted Dkk1, a Wnt inhibitor that affects angiogenesis, and blood vessels exhibited plasmalemma vesicle-associated protein, an angiogenic molecule. In summary, endomucin-positive blood vessels, when accompanied by osteoclasts in the ALP/αSMA/VCAM1/RANKL-reactive osteoblastic cell layers, invade the cortical bone, potentially due to the action of osteocyte-derived molecules such as DKK1.</p>","PeriodicalId":16079,"journal":{"name":"Journal of Histochemistry & Cytochemistry","volume":" ","pages":"309-327"},"PeriodicalIF":1.9,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11107436/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140898701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}