November 1999
Volume 40, Issue 12
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Retinal Cell Biology  |   November 1999
Immunocytochemical Study of the Distribution of a 16-kDa Galectin in the Chicken Retina
Author Affiliations
  • Cristina A. Maldonado
    From the Center of Electron Microscopy, Faculty of Medical Sciences, Universidad Nacional de Córdoba (UNC); the Departments of
  • Leonardo F. Castagna
    Biological Chemistry and
    Center of Products and Processes of Cordoba (CEPROCOR), Argentina.
  • Gabriel A. Rabinovich
    Clinical Biochemistry, Faculty of Chemical Sciences, National University of Cordoba (UNC); and the
  • Carlos A. Landa
    Biological Chemistry and
    Center of Products and Processes of Cordoba (CEPROCOR), Argentina.
Investigative Ophthalmology & Visual Science November 1999, Vol.40, 2971-2977. doi:
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      Cristina A. Maldonado, Leonardo F. Castagna, Gabriel A. Rabinovich, Carlos A. Landa; Immunocytochemical Study of the Distribution of a 16-kDa Galectin in the Chicken Retina. Invest. Ophthalmol. Vis. Sci. 1999;40(12):2971-2977.

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Abstract

purpose. To compare the distribution of a developmentally regulated 16-kDa galectin in the chicken retina at two different developmental stages: embryonic day 13 (ED13) and postnatal day 10 (PD10) retinas, by immunocytochemical analysis using light and transmission electron microscopy.

methods. Semi-thin and thin sections from ED13 and PD10 retinas were incubated with the IgG fraction purified from a rabbit antiserum raised against the 16-kDa chicken galectin. After incubation with colloidal gold particle–labeled goat anti-rabbit IgGs, tissue sections were analyzed by light and transmission electron microscopy. To improve the observation by light microscopy, semi-thin immunostained sections were intensified by silver enhancement.

results. In ED13 retinas a specific galectin labeling was detected in the region corresponding to the outer limiting membrane by light microscopy. This labeling seemed to be associated with the apical villi of Müller glial cells and their specialized junctions, as judged by transmission electron microscopy. In PD10 retinas, the more relevant finding revealed by light microscopy was the detection of a widespread immunostaining at the level of all retinal layers. The ultrastructural analysis indicated that the galectin labeling was detected at the cytoplasmic and nuclear compartments of Müller cells throughout the different retinal layers. Moreover, the labeling was detected in the inner limiting membrane in structures that resemble the end feet of Müller cells. The apical villi, and the specialized junctions of these glial cells, appeared more strongly stained in PD10 retinas than in ED13 retinas. Finally, highly intense labeling in a group of mitochondria localized in the inner segments of cone cells was observed.

conclusions. The present study clearly supports the idea that the subcellular distribution of the 16-kDa galectin changes during the development of the chicken retina. Morphologic changes associated with developmentally regulated expression and subcellular compartmentalization of the retinal galectin suggest that this lectin may be involved in the modulation of several processes in the visual system. Its presence in the apical villi of Müller cells may be related by modulatory functions between retina and pigment epithelium, but its presence in the cytoplasm and nucleus of these glial cells suggests a potential immunomodulatory role and its involvement in different metabolic processes between Müller and the other retinal cells. Finally, although the presence of galectins inside mitochondria has not been described before, this localization gives rise to the idea that this lectin may be involved in the modulation of mitochondrial processes.

Developmental changes in the expression of glycoconjugates, such as glycoproteins, 1 2 gangliosides, 3 and proteoglycans, 4 5 have been extensively described in the chicken retina. Moreover, cytochemical studies using monoclonal antibodies 6 7 and plant lectins 8 9 10 have shown topographic segregation and graded distribution of different glycoconjugates in retinal cells and tissue. 
We have previously described and characterized a developmentally regulated 16-kDa galectin in the chicken retina. 11 By using immunofluorescence microscopy we found that this endogenous lectin was localized mainly in the outer retina in postmitotic embryonic tissue and widely distributed in all retinal cell layers in the postnatal tissue. 12  
Galectins are part of a family of closely related carbohydrate-binding proteins that is widely distributed in a large number of vertebrate 13 14 15 and invertebrate tissues. 16 They show highly conserved cDNA nucleotide and primary amino acid sequences 13 17 and carbohydrate binding specificities, 18 and their expression is developmentally regulated in several tissues. 13 15 Although their precise function remains to be elucidated, galectins have been implicated in different biological processes, such as neural cell adhesion 19 and recognition, 20 connective tissue modulation, 21 metastasis, 22 immunomodulation, 23 24 cell growth control, 25 26 and apoptosis. 27 28 29  
In the present study, we analyzed by light and transmission electron microscopy the distribution of the 16-kDa galectin in the chicken retina. Results indicated that in the postmitotic embryonic retina, galectin expression is restricted to the outer limiting membrane at the level of the apical villi of Müller cells; and in the postnatal retina, it was also detected in the cytoplasm, nuclei, and end feet of these glial cells. Finally, galectin expression was also evident in groups of mitochondria present in the inner segments of cone cells. 
Materials and Methods
Experimental Animals
White leghorn chicken embryos incubated in a 37°C humidified incubator up to embryonic day 13 (ED13),and posthatched chicks from postnatal day 10 (PD10) were used. All procedures in this study were done in accordance with the ARVO Statement for the Use of Animals in Ophthalmic and Vision Research. 
Antiserum Preparation
A rabbit antiserum against chicken galectin was raised according to the method of Castagna and Landa. 11 The IgG fraction was purified by affinity chromatography on protein A–Sepharose matrix. Briefly, 1 volume of the rabbit antiserum was diluted with 9 volumes of phosphate-buffered saline (PBS; 125 mM NaCl, 25 mM Na2HPO4/NaH2PO4, pH 7.2) and incubated with 1 volume of protein A–Sepharose (Sigma, St. Louis, MO) during 30 minutes at room temperature. After several washes with PBS until no absorbance at 280 nm was detected, the adsorbed material was eluted from the affinity matrix with 100 mM glycine/HCl (pH 2.0). Then, the IgG fraction was neutralized with 0.1 volume of 1 M Tris buffer (pH 8.0), supplemented with bovine serum albumin (BSA) up to a final concentration of 3% (wt/vol), and stored in small aliquots at −20°C until use. 
Tissue Preparation
Briefly, whole eyecups from embryonic and postnatal chickens were fixed for 6 hours in 100 mM cacodylate buffer containing 2% (vol/vol) glutaraldehyde. For conventional electron microscopy, samples were treated with 1% (wt/vol) osmium tetroxide solution in cacodylate buffer for 1 hour at room temperature and embedded in Araldite. Thin sections were cut with a Porter-Blum MT-1 ultramicrotome, mounted on 250 mesh copper grids, and stained with uranyl acetate and lead citrate. 
For immunocytochemistry osmium fixation was omitted, and retinas were partially dehydrated in a series of graded ethanol solution up to 90% (vol/vol), and embedded in LR White, an acrylic-based medium (London Resin Co, Hampshire, UK), for 24 hours at 50°C. Semi-thin and thin sections were cut and mounted on slides or 250 mesh nickel grids, and processed for immunocytochemistry according to the protocols of light and electron microscopy, respectively. 
Immunogold Complex Preparations
For light microscopy, colloidal gold particles of 5-nm average diameter were prepared according to the method of Slot and Geuze, 30 combining sodium citrate and tannic acid as reducing agents. For transmission electron microscopy, colloidal gold particles of 16 nm in average diameter were prepared according to Frens 31 using sodium citrate as reducing agent. Then, particles were adsorbed to the IgG fraction purified from the antiserum raised against rabbit IgGs (Sigma; ∼0.25 μg of protein was necessary to stabilize 1 μl of colloidal gold solution). Finally, both immunogold complex preparations were centrifuged at 60,000g for 1 hour before use, and the pellet resuspended in PBS containing 0.01% (wt/vol) polyethylene glycol (PEG). 
Immunocytochemistry for Light Microscopy
Semi-thin sections of 0.5 μm were blocked with PBS containing 1% (wt/vol) BSA (PBS–BSA) for 15 minutes and incubated with a 1:300 dilution of the purified IgG fraction of the anti-galectin serum for 24 hours at 4°C. Then, sections were incubated with the optimal dilution of the 5-nm immunogold complexes for 1 hour at room temperature. Finally, gold particles were visualized by the silver enhancement procedure (Sigma) and were observed in a Zeiss photomicroscope III. To improve the visualization of the different retinal cell layers, semi-thin sections were only stained with toluidine blue. 
Controls were done as follows: Tissue sections were incubated with the purified IgG fraction preadsorbed with 10 μg/ml of the specific antigen; the purified IgG fraction was omitted in the first incubation step. 
Immunocytochemistry for Transmission Electron Microscopy
Sections of 60 nm were blocked with PBS–BSA for 15 minutes and incubated with a 1:700 dilution of the purified IgG fraction of the anti-galectin serum for 24 hours at 4°C. Then, grids were incubated with the optimal dilution of the 16-nm immunogold complex for 30 minutes at room temperature. Finally, sections were contrasted with 1% (wt/vol) aqueous uranyl acetate and observed in a Zeiss 109 electron microscope. 
Controls were done as described above. 
Results
Analysis of the Distribution of the 16-kDa Galectin in the Chicken Retina by Light Microscopy
To assess a whole picture of the galectin distribution in the chicken retina, a light microscopy analysis was performed using immunogold and silver enhancement procedures. 
As previously reported by immunofluorescence study, 12 the staining pattern of ED13 retinas using light microscopy appeared to be restricted to the outer retina (Fig. 1) . The immunogold and silver enhancement labeling revealed elongated particles at the level of the outer limiting membrane. Concerning the other retinal layers, such as the outer plexiform, inner nuclear, inner plexiform, and ganglion cell layers, we were unable to detect any significant galectin immunostaining. 
On the other hand, light microscopy analysis of PD 10 retinas (Fig. 1E) clearly showed that the distribution of the galectin was significantly different from in the ED13 retinas. At this developmental stage the more relevant observation was the detection of a widespread immunostaining in all retinal layers. The inner nuclear, ganglion cell, and photoreceptor layers, in addition to the outer limiting membrane, were found to be strongly labeled. The staining pattern observed from the inner to the outer limiting membranes resembled the characteristics labeling of Müller glial cells in the mature avian retina. 32 Furthermore, in the photoreceptor layer we detected strongly stained round particles immediately below the pigment epithelium. 
Nonspecific labeling in ED13 and PD10 retinas was discarded using appropriate controls as described in the Materials and Methods section (Figs. 1C and 1F , respectively). 
Analysis of the Subcellular Distribution of the 16-kDa Galectin in the Chicken Retina by Transmission Electron Microscopy
To study the distribution of the retinal galectin at the ultrastructural level, transmission electron microscopy was performed using an immunogold procedure. 
In ED13 retinas the staining pattern showed that the elongated particles detected at the outer limiting membrane, as observed by light microscopy (Fig. 2 , inset to 2B), were linked to the specialized junctions between Müller cells and photoreceptor cells, as well as to the apical villi of these glial cells (which are facing to the interphotoreceptor matrix and pigment epithelium; Figs. 2A and 2B ). 
In PD10 retinas as suggested by light microscopy, the staining pattern showed a homogeneous high electron density throughout all retinal layers from the outer to the inner limiting membranes, which seems to be the characteristic staining profile of Müller cells in the postnatal chicken retina. 32 In search for a link between the light and electronic level, we found that the round structures observed in PD10 retinas, which appeared strongly stained in light microscopy (Fig. 2D , inset, arrow) were associated to specialized junctions and apical villi of Müller cells (Figs. 2C and 2D) , as also observed in ED13 retinas. 
Müller cell bodies are sited in the inner nuclear layer, and irregularly thick and thin processes are projected in both directions to the outer and inner limiting membranes. 32 We detected an intense staining in the inner nuclear layer, which appeared to be associated to the cytoplasmic and nuclear compartments of these glial cells (Figs. 3 A and 3B, respectively). 
In addition to the light microscopy data (inset shared by Figs. 3D and 3E , upper arrowhead), we also showed immunogold labeling of the inner plexiform layer. It is known that is difficult to clearly identify Müller cell projections in this layer at the electron microscopic level, because they intermingle with neuronal fibers. However, to our view, most gold particles were seen over the electron dense projections that mostly correspond to Müller glial cells; although we cannot discard some neuronal staining (Fig. 3C) . Moreover, at the level of the inner limiting membrane, Müller cells showed specific labeling of end feet structures (Fig. 3E) that became reduced in diameter and intermingled with ganglion cells, in agreement with light microscopic data (inset to Figs. 3D and 3E , central and lower arrowheads). 
We have previously reported 12 a specific galectin immunostaining in different kinds of retinal cells by in vitro cell culture experiments; however, in thin sections of PD10 retinas, specific immunostaining in the nuclear compartment of retinal neurons was significantly lower than that in nuclear and cytoplasmic compartments of Müller cells (Fig. 3B) . It should be noted that light immunostaining supports the concept that neuronal nuclei are much less stained than those of Müller glial cells (Fig. 1D)
Strikingly, concerning the photoreceptor layer we detected specific immunostaining in a group of mitochondria present in the inner segments of cone cells (Fig. 4 B). This labeling could correspond to the round particles clearly detected in the photoreceptor layer by light microscopy (Fig. 4B , inset, arrowhead). We cannot discard the possibility that part of this staining could be over the surface of these organelles because we were not able to ascertain quantitatively the exact distribution of the staining. It is important to note that rod inner segments were almost free of specific labeling. 
Discussion
We have previously described the presence of a developmentally regulated 16-kDa galectin in the chicken retina. 11 The main contribution of this work is the close association of this lectin with Müller glial cells and groups of mitochondria present in the inner segment of cone cells. 
By immunofluorescence study, 12 we were unable to detect the presence of galectin at proliferative developmental stages; later, at postmitotic embryonic developmental stages its presence was clearly observed in the outer retina, and in the postnatal retina the galectin was widely distributed in all retinal layers. 
In the chicken retina there is only one kind of glial cells, Müller cells, which span the whole width of the retina extending from the outer to the inner limiting membranes; and the remaining retinal cells are arranged in different layers juxtaposed along these glial cells. 32 Müller cells have a broad range of functions all of which are vital to the health of the retinal neurons, such as the recycling of the neurotransmitter glutamate, the taking up and redistribution of the extracellular K+, the release of neuroactive substances (GABA, taurine, and dopamine), the removal of carbon dioxide and ammonia, and the modulation of phagocytic and immunomodulatory processes. 32 33 34  
Although the morphology of Müller cells has already been established in postmitotic ED13 retinas, immunostaining was only detected at the level of the specialized junctions of these cells, which are established among them and photoreceptor cells, and at the apical villi of these glial cells, which are facing to the interphotoreceptor matrix. This staining pattern suggests potential roles for the galectin in the interaction between retinal cells, as well as between the retina and pigment epithelium. Supporting this view, it has been previously described that galectins are involved in cell–matrix and cell–cell interactions by cross-linking polylactosamine chains on laminin in the extracellular matrix, and integrins, lysosome-associated membrane proteins (LAMPs), or lactosamine-containing glycolipids on the cellular surface. 13 15 35  
As previously reported, galectins have been localized at the cytoplasm and nucleus in different cell types. 13 15 Although we do not have at present a clear explanation for this finding, at later developmental stages of the chicken retina galectin expands its localization to both the cytoplasm and nuclei of Müller cells. The molecular mechanisms and environmental factors that define the final localization of the retinal galectin in Müller cells remain to be elucidated. In this context, a recent investigation reports a potential intracellular function for galectins as components of spliceosomes in the nucleus, which carry out splicing of mRNA precursors. 36  
Concerning the participation of Müller cells in phagocytic and immunomodulatory processes in the eye, 33 34 we have recently reported the presence of a differentially regulated galectin-1 in rat peritoneal macrophages, 37 38 and galectin-3 has also been described in murine microglial cells. 39 In addition, previous work has suggested a modulatory role of galectins in the immune response of autoimmune pathologies. 23 24 Recently, it has been suggested that the immunomodulatory properties of galectins take place through an early induction of programmed cell death. 27 28 29 This apoptotic mechanism becomes particularly relevant at the eye, which is considered an immunologic privileged organ 34 in view of its protection from inflammatory damage induced by the immune response. In this context, it is possible to suggest that the presence of the retinal galectin in Müller cells could be associated with immunomodulatory events such as phagocytic, suppressive, and apoptotic processes in the visual system. 
The detection of specific immunostaining in groups of mitochondria present in the inner segment of cone cells, which has not been reported yet, deserves particular consideration. Although galectins are cytosolic proteins lacking a signal peptide, they could be secreted by nonclassic secretory pathways or targeted to the nucleus or subcytosolic compartments. 35 40 Hence, this could be a potential way followed by the retinal galectin to get inside the mitochondria in way a similar to those of many mitochondrial proteins that are synthesized on cytoplasmic ribosomes. On the other hand, as many of the proteins encoded by the bcl-2 gene family are mainly localized in the outer mitochondrial membrane, 41 this lectin localization could also suggest other functions such as its involvement in the regulation of apoptotic events. 
Although it is very difficult to infer the precise function of the retinal galectin from the ultrastructural data, its subcellular distributions suggest versatile functional roles for this lectin, as has been previously reported for other members of the galectin family. 13 14 15 In this context, retinal galectin may be involved in cell–cell or cell–matrix interactions in the embryonic retina, whereas in the postnatal retina it may exhibit a more generalized functional role. Retinal galectin expression may also represent a modulatory signal for several processes that can take place in the cytoplasm and nucleus, that can regulate the innate and adaptive immune responses in the visual system, or both. 
 
Figure 1.
 
Distribution of retinal galectin as analyzed by light microscopy: sections of embryonic chicken retina (ED13; A, B, C) and of postnatal chicken retina (PD10; D, E, F). (A and D) Sections stained with toluidine blue. (B and E) Sections immunostained with the IgG fraction of the anti-galectin serum, revealed with colloidal gold complex followed by silver enhancement. (C and F) Controls with the appropriate dilution of the purified IgG fraction preadsorbed with 10 μg/ml of the specific antigen. GCL, ganglion cell layer; IPL, inner plexiform layer; INL, inner nuclear layer; ONL, outer nuclear layer; OLM, outer limiting membrane; Ph, photoreceptor layer; ILM, inner limiting membrane. Scale bar, 35 μm.
Figure 1.
 
Distribution of retinal galectin as analyzed by light microscopy: sections of embryonic chicken retina (ED13; A, B, C) and of postnatal chicken retina (PD10; D, E, F). (A and D) Sections stained with toluidine blue. (B and E) Sections immunostained with the IgG fraction of the anti-galectin serum, revealed with colloidal gold complex followed by silver enhancement. (C and F) Controls with the appropriate dilution of the purified IgG fraction preadsorbed with 10 μg/ml of the specific antigen. GCL, ganglion cell layer; IPL, inner plexiform layer; INL, inner nuclear layer; ONL, outer nuclear layer; OLM, outer limiting membrane; Ph, photoreceptor layer; ILM, inner limiting membrane. Scale bar, 35 μm.
Figure 2.
 
Ultrastructural localization of retinal galectin at the outer retina. ED13 (A, B) and PD10 (C, D) retina sections at the level of the outer limiting membrane. (A and C) Osmium fixed sections. (B and D) Sections immunostained with the IgG fraction of the anti-galectin serum revealed with colloidal gold complex. Outer retina analyzed by light microscopy corresponding to ED13 (B, inset) and PD10 (D, inset). MP, Müller cell projections; Ph, photoreceptor cell. Arrowhead indicates Zonula adherens, and * apical villi of Müller cell. Scale bar, 1 μm.
Figure 2.
 
Ultrastructural localization of retinal galectin at the outer retina. ED13 (A, B) and PD10 (C, D) retina sections at the level of the outer limiting membrane. (A and C) Osmium fixed sections. (B and D) Sections immunostained with the IgG fraction of the anti-galectin serum revealed with colloidal gold complex. Outer retina analyzed by light microscopy corresponding to ED13 (B, inset) and PD10 (D, inset). MP, Müller cell projections; Ph, photoreceptor cell. Arrowhead indicates Zonula adherens, and * apical villi of Müller cell. Scale bar, 1 μm.
Figure 3.
 
Ultrastructural localization of retinal galectin at the inner retina. Sections of PD10 retina immunostained with the IgG fraction of the anti-galectin serum revealed with colloidal gold complex. (A and B) Inner nuclear layer. (C) Inner plexiform layer. (D) Ganglion cell layer. (E) Ganglion cell fibers and end feet of Müller glial cells. Region corresponding to the inner nuclear layer of PD10 retina analyzed by light microscopy (inset shared by A and B). Region corresponding to the inner plexiform and ganglion cell layers of PD10 retina analyzed by light microscopy (inset shared by D and E). MP, Müller cell projections; MN, Müller cell nucleus; N, neuronal cell; G, ganglion cell; F, neuronal fibers. Scale bar, 1 μm.
Figure 3.
 
Ultrastructural localization of retinal galectin at the inner retina. Sections of PD10 retina immunostained with the IgG fraction of the anti-galectin serum revealed with colloidal gold complex. (A and B) Inner nuclear layer. (C) Inner plexiform layer. (D) Ganglion cell layer. (E) Ganglion cell fibers and end feet of Müller glial cells. Region corresponding to the inner nuclear layer of PD10 retina analyzed by light microscopy (inset shared by A and B). Region corresponding to the inner plexiform and ganglion cell layers of PD10 retina analyzed by light microscopy (inset shared by D and E). MP, Müller cell projections; MN, Müller cell nucleus; N, neuronal cell; G, ganglion cell; F, neuronal fibers. Scale bar, 1 μm.
Figure 4.
 
Ultrastructural localization of retinal galectin at the photoreceptor layer. Osmium fixed section of PD10 retina (A). Section immunostained with the IgG fraction of the anti-galectin serum and revealed with colloidal gold complex (B). Control with the appropriate dilution of the purified IgG fraction preadsorbed with 10μ g/ml of the specific antigen (C). Region corresponding to the photoreceptor layer of PD10 retina analyzed by light microscopy (B, inset). C, cone cell; R, rod cell. Scale bar, 1 μm.
Figure 4.
 
Ultrastructural localization of retinal galectin at the photoreceptor layer. Osmium fixed section of PD10 retina (A). Section immunostained with the IgG fraction of the anti-galectin serum and revealed with colloidal gold complex (B). Control with the appropriate dilution of the purified IgG fraction preadsorbed with 10μ g/ml of the specific antigen (C). Region corresponding to the photoreceptor layer of PD10 retina analyzed by light microscopy (B, inset). C, cone cell; R, rod cell. Scale bar, 1 μm.
Mintz G, Glaser L. Specific glycoprotein changes during development of the chick neural retin. J Cell Bio. 1978;79:132–137. [CrossRef]
Sheffield JB. Glycoprotein differences among cells of the 14-day embryonic chick neural retin. J Supramol Struc. 1981;17:51–60.
Maccioni HJF, Landa CA, Panzetta P. Developmental regulation of ganglioside biosynthesis: studies in the chick embryo retina. Extracellular and Intracellular Messengers in the Vertebrate Retin. 1989;117–127. Alan R. Liss New York.
Morris JE, Hopwood JJ, Dorfman A. Biosynthesis of glycosaminoglycans in the developing retin. Dev Bio. 1977;58:313–327. [CrossRef]
Needham JK, Adler R, Hewitt T. Proteoglycan synthesis in flat cell-free cultures of chick embryo retinal neurons and photoreceptor. Dev Bio. 1988;126:304–314. [CrossRef]
Grunwald GB, Fredman P, Magnani JL, Trisler D, Ginsburg V, Niremberg M. Monoclonal antibody 18B8 detects gangliosides associated with neuronal differentiation and synapse formatio. Proc Natl Acad Sci US. 1985;82:4008–4012. [CrossRef]
Dubois C, Magnani JL, Grunwald GB, et al. Monoclonal antibody 18B8 which detects synapse-associated antigens, binds to ganglioside GT. J Biol Che. 1986;261:3826–3830.
Adler R, Lindsey JD, Elsner CL. Expression of cone like properties by chick embryo retinal cells in glia-free monolayer culture. J Cell Bio. 1984;99:1173–1178. [CrossRef]
Blanks JC, Johnson LV. Specific binding of peanut lectin to a class of photoreceptor cells: a species comparison. Invest Ophthalmol Vis Sc. 1984;25:546–557.
Arregui C, Barra HS, Landa CA. Peanut agglutinin binding glycoproteins in the chick retina: their presence in Müller glia cells. J Neurosci Re. 1992;31:532–542. [CrossRef]
Castagna LF, Landa CA. Isolation and characterization of a soluble lactose binding lectin from postnatal chicken retin. J Neurosci Re. 1994;37:750–758. [CrossRef]
Castagna LF, Landa CA. Distribution of an endogenous 16 kD S-lac lectin in the chicken retin. Invest Ophthalmol Vis Sc. 1994;35:4310–4316.
Harrison L. Soluble β-galactoside-binding lectins in vertebrate. Kilpatrick DC Van Driessche E Bog–Hansen TC eds. Lectin Review. 1991;1:17–39.
Barondes SH, Castronovo V, Cooper DNW, et al. Galectins, a family of β-galactoside-binding lectin. Cel. 1994;76:597–598. [CrossRef]
Barondes SH, Cooper DNW, Gitt MA, Leffler H. Galectins: structure and function of a large family of animal lectins. J Biol Che. 1994;269:20807–20810.
Hirabayashi J, Kasai K. The family of metazoan metal-independent β-galactoside-binding lectin: structure, function and molecular evolution. Glycobiolog. 1993;3:297–304. [CrossRef]
Caron M, Bladier D, Joubert R. Soluble galactoside-binding lectins: a protein family with common properties. Int J Bioche. 1990;22:1379–1385. [CrossRef]
Kasai K, Hirabayashi J. Galectins: a family of animal lectins that decipher glycocodes. J Bioche. 1996;119:1–18. [CrossRef]
Joubert R, Michel C, Bladier D. Brain lectin-mediated agglutinability of dissociated cells from embryonic and postnatal mouse brai. Dev Brain Re. 1987;36:146–150. [CrossRef]
Hynes MA, Gitt M, Barondes SH, Jessell TN, Buck LB. Selective expression of an endogenous lactose binding lectin gene in subsets of central and peripheral neuron. J Neurosc. 1990;10:1004–1013.
Clerch LB, Whitney PL, Massaro D. Rat lung lectin synthesis, degradation and activation: developmental regulation and modulation by dexamethasone. Biochem . 1987;245:683–690.
Akahani S, Inohara H, Nangia–Makker P, Raz A. Galectin-3 in tumor metastasi. Trends Glycosci Glycotechno. 1997;9:69–75. [CrossRef]
Levi G, Tarrab–Hazdai R, Teichberg VI. Prevention and therapy with electrolectin of experimental autoimmune myasthenia gravis in rabbit. Eur J Immuno. 1983;13:500–507. [CrossRef]
Offner HB, Celnik B, Bringman TS, Casentini–Borocz D, Nedwin GE, Vandenbark A. Recombinant human β-galactoside binding lectin suppresses clinical and histological signs of experimental autoimmune encephalomyeliti. J Neuroimmuno. 1990;28:177–184. [CrossRef]
Wells V, Mallucci L. Identification of an autocrine negative growth factor: mouse β galactoside binding proteins a cytostatic and cell growth regulator. Cel. 1991;64:91–97. [CrossRef]
Adams L, Scott GK, Weinberg CS. Biphasic modulation of cell growth by recombinant human galectin-. Biochim Biophys Act. 1996;1312:137–144. [CrossRef]
Perillo NL, Pace KE, Seihamer JJ, Baum LG. Apoptosis of T-cells mediated by galectin-. Natur. 1996;378:736–739.
Yang RY, Hsu DK, Liu FT. Expression of galectin-3 modulates T-cell growth and apoptosi. Proc Natl Acad Sci US. 1996;93:6737–6742. [CrossRef]
Rabinovich GA, Modesti NM, Castagna LF, Landa CA, Riera CM, Sotomayor CE. Specific inhibition of lymphocyte proliferation and induction of apoptosis by CLL-I, a β-galactoside-binding lecti. J Bioche. 1997;122:365–373. [CrossRef]
Slot JW, Geuze HJ. A new method of preparing gold probes for multiple-labeling cytochemistr. Eur J Cell Bio. 1985;38:87–95.
Frens G. Controlled nucleation of the regulation of the particle size in monodisperse gold solution. Nat Phys Sc. 1973;241:20–22. [CrossRef]
Moscona AA, Linser P. Developmental and experimental changes in retinal glial cells: cell interactions and control of phenotype expression and stability. Curr Top Dev Bio. 1983;18:155–188.
Reichenbach A, Ronbinson SR. The involvement of Müller cells in the outer retin. Djamgoz MBA Archer SN Vallerga S eds. Neurobiology and Clinical Aspects of the Outer Retin. 1995;395–416. Chapman and Hall London.
Niederkorn JY. Immune privilege and immune regulation in the ey. Adv Immuno. 1990;48:191–226.
Cooper DNW. Galectin-1: secretion and modulation of cell interactions with laminin. Trends Glycosci Glycotechno. 1997;9:57–67. [CrossRef]
Patterson RJ, Dagher SF, Vyakarnam A, Wang JL. Nuclear galectins: functionally redundant components in processing of pre-mRNA. Trends Glycosci Glycotechno. 1997;9:77–85. [CrossRef]
Rabinovich GA, Castagna LF, Landa CA, Riera CM, Sotomayor CE. Regulated expression of a 16 kDa galectin-like protein in rat activated macrophage. J Leukoc Bio. 1996;59:363–370.
Rabinovich GA, Iglesias MM, Castagna LF, et al. Activated rat macrophages produce a galectin-1 like protein that induces apoptosis of T cells: biochemical and functional characterization. J Immuno. 1998;160:4831–4840.
Pesheva P, Urschel S, Frei K, Probstmeier R. Murine microglial cells express functionally active galectin-3 in vitr. J Neurosci Re. 1998;51:49–57. [CrossRef]
Leffler H. Introduction to galectin. Trends Glycosci Glycotechno. 1997;9:9–19. [CrossRef]
Kroemer G. The proto-oncogene Bcl-2 and its role in regulating apoptosi. Nat Me. 1997;3:614–620. [CrossRef]
Figure 1.
 
Distribution of retinal galectin as analyzed by light microscopy: sections of embryonic chicken retina (ED13; A, B, C) and of postnatal chicken retina (PD10; D, E, F). (A and D) Sections stained with toluidine blue. (B and E) Sections immunostained with the IgG fraction of the anti-galectin serum, revealed with colloidal gold complex followed by silver enhancement. (C and F) Controls with the appropriate dilution of the purified IgG fraction preadsorbed with 10 μg/ml of the specific antigen. GCL, ganglion cell layer; IPL, inner plexiform layer; INL, inner nuclear layer; ONL, outer nuclear layer; OLM, outer limiting membrane; Ph, photoreceptor layer; ILM, inner limiting membrane. Scale bar, 35 μm.
Figure 1.
 
Distribution of retinal galectin as analyzed by light microscopy: sections of embryonic chicken retina (ED13; A, B, C) and of postnatal chicken retina (PD10; D, E, F). (A and D) Sections stained with toluidine blue. (B and E) Sections immunostained with the IgG fraction of the anti-galectin serum, revealed with colloidal gold complex followed by silver enhancement. (C and F) Controls with the appropriate dilution of the purified IgG fraction preadsorbed with 10 μg/ml of the specific antigen. GCL, ganglion cell layer; IPL, inner plexiform layer; INL, inner nuclear layer; ONL, outer nuclear layer; OLM, outer limiting membrane; Ph, photoreceptor layer; ILM, inner limiting membrane. Scale bar, 35 μm.
Figure 2.
 
Ultrastructural localization of retinal galectin at the outer retina. ED13 (A, B) and PD10 (C, D) retina sections at the level of the outer limiting membrane. (A and C) Osmium fixed sections. (B and D) Sections immunostained with the IgG fraction of the anti-galectin serum revealed with colloidal gold complex. Outer retina analyzed by light microscopy corresponding to ED13 (B, inset) and PD10 (D, inset). MP, Müller cell projections; Ph, photoreceptor cell. Arrowhead indicates Zonula adherens, and * apical villi of Müller cell. Scale bar, 1 μm.
Figure 2.
 
Ultrastructural localization of retinal galectin at the outer retina. ED13 (A, B) and PD10 (C, D) retina sections at the level of the outer limiting membrane. (A and C) Osmium fixed sections. (B and D) Sections immunostained with the IgG fraction of the anti-galectin serum revealed with colloidal gold complex. Outer retina analyzed by light microscopy corresponding to ED13 (B, inset) and PD10 (D, inset). MP, Müller cell projections; Ph, photoreceptor cell. Arrowhead indicates Zonula adherens, and * apical villi of Müller cell. Scale bar, 1 μm.
Figure 3.
 
Ultrastructural localization of retinal galectin at the inner retina. Sections of PD10 retina immunostained with the IgG fraction of the anti-galectin serum revealed with colloidal gold complex. (A and B) Inner nuclear layer. (C) Inner plexiform layer. (D) Ganglion cell layer. (E) Ganglion cell fibers and end feet of Müller glial cells. Region corresponding to the inner nuclear layer of PD10 retina analyzed by light microscopy (inset shared by A and B). Region corresponding to the inner plexiform and ganglion cell layers of PD10 retina analyzed by light microscopy (inset shared by D and E). MP, Müller cell projections; MN, Müller cell nucleus; N, neuronal cell; G, ganglion cell; F, neuronal fibers. Scale bar, 1 μm.
Figure 3.
 
Ultrastructural localization of retinal galectin at the inner retina. Sections of PD10 retina immunostained with the IgG fraction of the anti-galectin serum revealed with colloidal gold complex. (A and B) Inner nuclear layer. (C) Inner plexiform layer. (D) Ganglion cell layer. (E) Ganglion cell fibers and end feet of Müller glial cells. Region corresponding to the inner nuclear layer of PD10 retina analyzed by light microscopy (inset shared by A and B). Region corresponding to the inner plexiform and ganglion cell layers of PD10 retina analyzed by light microscopy (inset shared by D and E). MP, Müller cell projections; MN, Müller cell nucleus; N, neuronal cell; G, ganglion cell; F, neuronal fibers. Scale bar, 1 μm.
Figure 4.
 
Ultrastructural localization of retinal galectin at the photoreceptor layer. Osmium fixed section of PD10 retina (A). Section immunostained with the IgG fraction of the anti-galectin serum and revealed with colloidal gold complex (B). Control with the appropriate dilution of the purified IgG fraction preadsorbed with 10μ g/ml of the specific antigen (C). Region corresponding to the photoreceptor layer of PD10 retina analyzed by light microscopy (B, inset). C, cone cell; R, rod cell. Scale bar, 1 μm.
Figure 4.
 
Ultrastructural localization of retinal galectin at the photoreceptor layer. Osmium fixed section of PD10 retina (A). Section immunostained with the IgG fraction of the anti-galectin serum and revealed with colloidal gold complex (B). Control with the appropriate dilution of the purified IgG fraction preadsorbed with 10μ g/ml of the specific antigen (C). Region corresponding to the photoreceptor layer of PD10 retina analyzed by light microscopy (B, inset). C, cone cell; R, rod cell. Scale bar, 1 μm.
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