Journal of Histochemistry & Cytochemistry

Fu, Yineng; Nagy, Janice A.; Brown, Lawrence F.; Shih, Shou-Ching; Johnson, Pamela Y.; Chan, Christina K.; Dvorak, Harold F.; Wight, Thomas N.

doi: 10.1369/0022155411401748pmid: 21411713

Malignant tumors and chronic inflammatory diseases induce angiogenesis by overexpressing vascular endothelial growth factor A (VEGF-A/VPF). VEGF-A-induced pathological angiogenesis can be mimicked in immunoincompetent mice with an adenoviral vector expressing VEGF-A164 (Ad-VEGF-A164). The initial step is generation of greatly enlarged “mother” vessels (MV) from preexisting normal venules by a process involving degradation of their rigid basement membranes. Immunohistochemical and Western blot analyses revealed that versican, an extracellular matrix component in the basement membranes of venules, is degraded early in the course of MV formation, resulting in the appearance of a versican N-terminal DPEAAE fragment associated with MV endothelial cells. The protease ADAMTS-1, known to cleave versican near its N terminus to generate DPEAAE, is also upregulated by VEGF-A in parallel with MV formation and localizes to the endothelium of the developing MV. The authors also show that MMP-15 (MT-2 MMP), a protease that activates ADAMTS-1, is upregulated by VEGF-A in endothelial cells in vitro and in vivo. These data suggest VEGF-A initiates MV formation, in part, by inducing the expression of endothelial cell proteases such as ADAMTS-1 and MMP-15 that act in concert to degrade venular basement membrane versican. Thus, versican is actively processed during the early course of VEGF-A-induced pathological angiogenesis.

Zhao, Yingying; Liu, Yuxuan; Chen, Zhengshan; Korteweg, Christine; Gu, Jiang

doi: 10.1369/0022155411400871pmid: 21430258

Traditional views hold that immunoglobulin G (IgG) in the human umbilical cord is internalized by human umbilical endothelial cells for passive immunity. In this study, the protein and mRNA transcripts of IgG were found in the cytoplasm of human umbilical endothelial cells by immunohistochemistry, in situ hybridization, and reverse transcription PCR (RT-PCR). The essential enzymes for IgG synthesis and assembling, RAG1 (recombination activating gene 1), RAG2, and variable (V), diversity (D), and joining (J) segments for recombination of IgG, were also found in these cells by RT-PCR and real-time PCR. These results indicate that umbilical endothelial cells are capable of synthesizing IgG with properties similar to those of immune cells and that they may play additional roles besides lining the vessels and transporting IgG.

Atai, Nadia A.; Renkema-Mills, Nynke A.; Bosman, Joost; Schmidt, Nadja; Rijkeboer, Denise; Tigchelaar, Wikky; Bosch, Klazien S.; Troost, Dirk; Jonker, Ard; Bleeker, Fonnet E.; Miletic, Hrvoje; Bjerkvig, Rolf; De Witt Hamer, Philip C.; Van Noorden, Cornelis J. F.

Köhler, Christoph N.

doi: 10.1369/0022155411400875pmid: 21411712

The author has recently reported the distribution of the cytoskeleton-associated protein caldesmon in spleen and lymph nodes detected with different antibodies against caldesmon (J Histochem Cytochem 58:183–193, 2010). Here the author reports the distribution of caldesmon in the CNS and ganglia of the mouse using the same antibodies. Western blot analysis of mouse brain and spinal cord showed the preponderance of l-caldesmon and suggested at least two l-caldesmon isoforms in the brain. Immunostaining revealed the predominant reactivity of smooth muscle cells and cells resembling pericytes of many large and small blood vessels, ependymocytes, and secretory cells of the pineal gland and pituitary gland. Neuronal perikarya and neuropil in general displayed no or weak immunoreactivity, but there was stronger labeling of neuronal perikarya in dorsal root and trigeminal ganglia. In the brain, staining of the neuropil was stronger in the molecular layers of the dentate gyrus and cerebellum. Results show that caldesmon is expressed in many different cell types in the CNS and ganglia, consistent with the notion that l-caldesmon is ubiquitously expressed, but it appears most concentrated in smooth muscle cells, pericytes, epithelial cells, secretory cells, and neuronal perikarya in dorsal root and trigeminal ganglia.

Saito, Kotaro; Nakatomi, Mitsushiro; Ida-Yonemochi, Hiroko; Kenmotsu, Shin-ichi; Ohshima, Hayato

doi: 10.1369/0022155411403314pmid: 21430263

Dental pulp elaborates both bone and dentin under pathological conditions such as tooth replantation/transplantation. This study aims to clarify the expression of granulocyte macrophage colony-stimulating factor (GM-CSF) and osteopontin (OPN) in the process of reparative dentin formation by allogenic tooth transplantation using in situ hybridization for OPN and immunohistochemistry for GM-CSF and OPN at both levels of light and electron microscopes. Following the extraction of the mouse molar, the roots and pulp floor were resected and immediately allografted into the sublingual region. On days 1 to 3, immunocompetent cells such as macrophages and dendritic cells expressed both GM-CSF and OPN, and some of them were arranged along the pulp-dentin border and extended their cellular processes into the dentinal tubules. On days 5 to 7, tubular dentin formation commenced next to the preexisting dentin at the pulp horn where nestin-positive odontoblast-like cells were arranged. Until day 14, bone-like tissue formation occurred in the pulp chamber, where OPN-positive osteoblasts surrounded the bone matrix. These results suggest that the secretion of GM-CSF and OPN by immunocompetent cells such as macrophages and dendritic cells plays a role in the maturation of dendritic cells and the differentiation of odontoblasts, respectively, in the regenerated pulp tissue following tooth transplantation.

Rebello, Michelle R.; Aktas, Adem; Medler, Kathryn F.

doi: 10.1369/0022155411402352pmid: 21527586

It is well established that calcium is a critical signaling molecule in the transduction of taste stimuli within the peripheral taste system. However, little is known about the regulation and termination of these calcium signals in the taste system. The authors used Western blot, immunocytochemical, and RT-PCR analyses to evaluate the expression of multiple calcium binding proteins in mouse circumvallate taste papillae, including parvalbumin, calbindin D28k, calretinin, neurocalcin, NCS-1 (or frequenin), and CaBP. They found that all of the calcium binding proteins they tested were expressed in mouse circumvallate taste cells with the exception of NCS-1. The authors correlated the expression patterns of these calcium binding proteins with a marker for type II cells and found that neurocalcin was expressed in 80% of type II cells, whereas parvalbumin was found in less than 10% of the type II cells. Calretinin, calbindin, and CaBP were expressed in about half of the type II cells. These data reveal that multiple calcium binding proteins are highly expressed in taste cells and have distinct expression patterns that likely reflect their different roles within taste receptor cells.

Melo, Rossana C. N.; D’Avila, Heloisa; Wan, Hsiao-Ching; Bozza, Patrícia T.; Dvorak, Ann M.; Weller, Peter F.

doi: 10.1369/0022155411404073pmid: 21430261

Lipid bodies (LBs), also known as lipid droplets, have increasingly been recognized as functionally active organelles linked to diverse biological functions and human diseases. These organelles are actively formed in vivo within cells from the immune system, such as macrophages, neutrophils, and eosinophils, in response to different inflammatory conditions and are sites for synthesis and storage of inflammatory mediators. In this review, the authors discuss structural and functional aspects of LBs and current imaging techniques to visualize these organelles in cells engaged in inflammatory processes, including infectious diseases. The dynamic morphological aspects of LBs in leukocytes as inducible, newly formable organelles, elicitable in response to stimuli that lead to cellular activation, contribute to the evolving understanding of LBs as organelles that are critical regulators of different inflammatory diseases, key markers of leukocyte activation, and attractive targets for novel anti-inflammatory therapies.

Aiba, Motohiko; Fujibayashi, Mariko

doi: 10.1369/0022155411404071pmid: 21411711

Few studies have examined functional adrenal zonation throughout human life. Adrenals from 61 surgical/autopsy patients from 1 day old to 92 years old who had no clinical endocrinological/mineralocorticoid abnormalities were assessed for immunohistochemically defined adrenal zonation. The zona glomerulosa (zG) was well developed in all 11 patients ranging in age from newborn to the 30s. After 40 years of age, however, the zG occupied less than one-quarter of the adrenal circumference, suggestive of zG involution. The other subcapsular areas were occupied by the progenitor zone (zP), which expressed neither cytochrome P450aldo nor P45011β but 3β-hydroxysteroid dehydrogenase and P450scc, although some autopsy cases had adrenals with zG zonation because of secondary aldosteronism, and others who had experienced severe stresses showed subcapsular zona fasciculata (zF). In conclusion, the adrenal cortex consists of homogeneous zG-topped columns from birth to adolescence. Subsequently, in the fifth decade of life, the cortex is reconstituted by integration of three types of cortical columns: scattered zG-topped columns and zonal zP-topped columns, the latter having the ability for bidirectional differentiation into either zG-topped columns or zF-topped columns, according to secondary aldosteronism or the presence of severe stresses. Such adrenocortical remodeling is ascribed to high-sodium/low-potassium diets.