Histology and histopathology Vol.26, nº2 (2011)

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  • Publication
    Open Access
    Regulated expression of galectin-3, a multifunctional glycan-binding protein, in haematopoietic and non-haematopoietic tissues
    (Murcia: F. Hernández, 2011) Sundblad, Victoria; Croci, Diego O.; Rabinovich, Gabriel A.
    Galectin-3 belongs to a family of highly conserved animal lectins characterized by their ability to recognize multiple N-acetyllactosamine sequences, which can be displayed on both N- and O-glycans on cell surface glycoconjugates. Although first identified in macrophages, galectin-3 (also called ‘Mac-2, εBP, CBP35 or L-29’) has been found to be widely distributed in several tissues and developmental stages where, depending on its extracellular or intracellular localization, it can display a broad diversity of biological functions including immunomodulation, host-pathogen interactions, embryogenesis, angiogenesis, cell migration, wound healing and apoptosis. In spite of the existence of several reviews describing the multifunctional properties of galectin-3, an integrated view of the regulated expression of this glycan-binding protein in different normal tissues is lacking. Here we attempt to summarize and integrate available information on galectin-3 distribution in normal haematopoietic and non-haematopoietic tissues, mainly in adulthood, with only a brief reference to its expression during embryonic stages. In addition, given the multiplicity of biological roles attributed to this protein, a brief description of galectin-3 functions is also included. Understanding how galectin-3 is regulated in normal tissues will contribute to a rational design of approaches aimed at modulating galectin-3 expression and subcellular localization for experimental and therapeutic purposes.
  • Publication
    Open Access
    Physiopathologic dynamics of vesicle traffic in astrocytes
    (Murcia: F. Hernández, 2011) Potokar, Maja; Stenovec, Matjaž; Kreft, Marko; Gabrijel, Mateja; Zorec, Robert
    . The view of how astrocytes, a type of glial cells, contribute to the functioning of the central nervous system (CNS) has changed greatly in the last decade. Although glial cells outnumber neurons in the mammalian brain, it was considered for over a century that they played a subservient role to neurons. This view changed. Functions thought to be exclusively present in neurons, i.e. excitability mediated release of chemical messengers, has also been demonstrated in astrocytes. In this process, following an increase in cytosolic calcium activity, membrane bound vesicles, storing chemical messengers (gliotransmitters), fuse with the plasma membrane, a process known as exocytosis, permitting the exit of vesicle cargo into the extracellular space. Vesicles are delivered to and are removed from the site of exocytosis by an amazingly complex set of processes that we have only started to learn about recently. In this paper we review vesicle traffic, which is subject to physiological regulation and may be changed under pathological conditions.
  • Publication
    Open Access
    Quantitative mRNA expression analysis in kidney glomeruli using microdissection techniques
    (Murcia: F. Hernández, 2011) De Spiegelaere, Ward; Cornillie, Pieter; Van Poucke, Mario; Peelman, Luc; Burvenich, Christian; Van den Broeck, Wim
    The introduction of new tools for molecular analysis, such as RT-qPCR and microarrays, has provided researchers with powerful applications to study renal disease and development. However, the high cellular heterogeneity of the renal tissue complicates the molecular analysis of specific cells and cell groups such as glomerular or tubular cells. In the past, glomerular sieving and manual dissection were used for the isolation of glomeruli. However, these techniques cannot be used for the isolation of specific glomeruli or for the coisolation of additional tissue fractions. In recent decades, new microdissection techniques such as laser-assisted microdissection have been developed. These applications allow the isolation of small cell groups from heterogeneous tissue for molecular analysis, including microarray and RT-qPCR. Although very promising, some drawbacks are associated with these techniques. The isolated sample material is generally small and requires sensitive assays. In addition, the long sample processing time may result in a considerable loss of RNA integrity. Careful optimization and rigorous quality analysis should overcome these drawbacks. In the present paper, the recent literature on the application of microdissection techniques in kidney research is reviewed, together with a discussion of the critical issues that are essential for the application of quantitative mRNA expression analysis with RT-qPCR on microdissected samples.
  • Publication
    Open Access
    Expression of stem cell marker CD133 in fetal and adult human kidneys and pauci-immune crescentic glomerulonephritis
    (Murcia: F. Hernández, 2011) Kim, Kyungeun; Park, Bong-Hee; Ihm, Hyojin; Kim, Kyung Min; Jeong, Jinuk; Chang, Jai Won; Cho, Yong Mee
    Background: Different cell types in the kidney, including those in tubules, glomeruli, and interstitium, have been proposed as candidate adult renal stem cells, raising controversy about the very existence of such cells. In this study, we sought to clarify the location and nature of adult renal stem cells and to address their reparative role in native kidney disease. Methods: The expression of the stem cell marker CD133 was analyzed in 31 normal fetal and adult human kidneys by immunohistochemical methods. Co expression of CD133 with Ki-67 and tubule specific markers was also examined. Seventeen cases of pauciimmune glomerulonephritis were evaluated for CD133 and Ki-67 expression, and this was correlated with the patients’ renal prognosis. Results: CD133 was expressed in S-shaped bodies of fetal kidneys and co-expressed with Ki-67. It was highly expressed in mature tubules of fetal and adult kidneys without Ki-67 co-expression. CD133+ cells were most abundant in the S3 segment of proximal tubules and co-expressed with the distal tubule marker, suggesting multipotency. Most tubular CD133+ cells in normal adult kidneys exhibited pathologic features of acute and chronic injury. In pauci-immune glomerulonephritis, tubular CD133 and Ki-67 coexpression tended to be higher in cases where renal function recovered. Conclusion: These results suggest that adult renal stem cells reside predominantly in the S3 segment of the proximal tubule, where they remain mitotically silent under normal conditions, but can be induced by cellular injury. These results also suggest a potential role for adult renal stem cells in recovery from native human kidney disease.
  • Publication
    Open Access
    Time-course expression of metallothioneins and tissue metals in chronic relapsing form of experimental autoimmune encephalomyelitis
    (Murcia: F. Hernández, 2011) Jakovac, Hrvoje; Grebic, Damir; Tota, Marin; Barac-Latas, Vesna; Mrakovčić-Šutić, Ines; Milin, Čedomila; Radosevic-Stasic, Biserka
    To elucidate the role of metallothioneins (MTs) in the pathomechanisms of autoimmune CNS disorders we estimated the expression of MTs I+II and the tissue concentrations of Zn2+ and Cu2+ in the brain, spinal cord (SC) and in the liver during the periods of attacks and remissions in chronic relapsing experimental autoimmune encephalomyelitis (CR-EAE). Disease was induced in the genetically susceptible Dark Agouti (DA) rats by subcutaneous injection of bovine brain homogenate in CFA. Control rats were treated with CFA. The data, obtained by clinical assessment, immunohistochemistry and inductivity coupled plasma spectrometry, have shown that during the first attack (on the 12th day) MTs I+II were markedly upregulated in subarachnoid regions and perivascular space on astrocytes, microglia and on spinal neurons. Simultaneously, the concentrations of zinc in the SC and zinc and copper in the liver have found to be increased. During the second attack (on the 22nd day) a new overexpression of MTs was found in the cerebellum, in sulcus hippocampi, in spinal neurons and particularly in hepatocytes around the central vein. Concomitantly, in the brain and SC the concentration of copper increased. The data point to a neuroprotective role of MTs and to an important regulatory role of essential metals and hepatic MTs in the pathogenesis of CR-EAE