Biomedical subjects

B Fraile

Publications and source records attributed to B Fraile.

At least 37 records · Page 2Linked to original sources

PubMed2000

Interferon-gamma and its functional receptors overexpression in benign prostatic hyperplasia and prostatic carcinoma: parallelism with c-myc and p53 expression.

The therapeutic potential of IFN-gamma in prostatic cancer has been documented in several reports, although no immunohistochemical studies of this factor and its receptors in the prostate have been reported. The aim of the present study was to investigate the expression of IFN-gamma and its receptor components (IFN-gamma-Ralpha and IFN-gamma-Rbeta) in normal prostate, benign prostatic hyperplasia (BPH) and prostatic cancer (PC), as well as the possible relationship between this factor and the products of the p53 gene (the wild and mutant forms) and the oncogene c-myc, by means of immunochemical techniques (Western blot, ELISA, and quantification of immunostaining in histological sections). In normal prostate, IFN-gamma and its two receptors were expressed in the basal cells of the epithelium and some stromal cells. In BPH specimens, immunostaining of basal epithelial cells was significantly increased for IFN-gamma and its a receptor, whereas stromal cell immunostaining was significantly increased for IFN-gamma and its b receptor. In addition, columnar epithelial cells immunostained for IFNbeta-Rbeta. PC specimens differed from BPH specimens in the significantly increased immunostaining of epithelial cells for IFN-gamma and its two receptors, and the immunostaining of columnar epithelial cells for IFN-gamma-Ralpha. Immunodetection of wild-p53 was weak and limited to some stromal cells in the three types of specimens. Immunostainings for both mutant-p53 and c-myc were negative in normal prostate, and positive in the epithelium and stromal cells of both BPH and PC specimens. Immunostaining intensity in PC was significantly higher than in BPH. These observations suggest that the expression of both mutant-p53 and c-myc, together with other factors, might be involved in the development of prostatic hyperplasia and neoplasia, while the increased expression of IFN-gamma and its receptors could be regarded as an attempt, although insufficient, to inhibit the uncontrolled cell proliferation.

Aged↗

PubMed1999

Internalization of factor J and cellular signalization after factor J-cell interaction.

Factor J (FJ) is a cationic glycoprotein with inhibitory activity in vitro against both classical and alternative pathways of complement activation. Recently FJ has been implicated in adhesion to several cell lines, through a membrane receptor identified as nucleolin. In the present work we study the events that follow the binding of FJ to cells. After incubation of K562 with FJ, this protein was internalized actively and localized in the cytoplasm and nucleus. Adhesion to immobilized FJ induced tyrosine phosphorylation of several intracellular proteins in Jurkat cell line with a similar pattern to that induced by fibronectin (FN), an extracellular matrix protein. This effect was maximal at 5 min and decreased after 10 min, and inhibited by anti-FJ monoclonal antibody (mAb). These results suggest that the binding of FJ to cells may play an important role in transduction of biochemical signals across the plasma membrane to the cell interior.

Antibodies, Monoclonal↗

PubMed1999

Ultrastructure and lectin cytochemistry of the cloacal ventral glands in the male newt Triturus marmoratus marmoratus.

Ventral glands are found in the cloacal walls of male urodele amphibians except for sirenids. These glands are mucous, and secrete substances that will form part of the spermatophore used in transfer of sperm during fertilization. Ventral glands are formed by secretory and ductal portions; both possess epithelial and myoepithelial cells with different characteristics. Urodeles have cyclic reproduction, and cloacal ventral glands show seasonal differences with electron microscopy. The glycoproteins secreted by these glands have been studied by means of lectin histochemistry. The labeling was detected mainly in the nuclei, rough endoplasmic reticulum, Golgi complex, and cytosol. Secretory granules in these glands are composed by mucous glycoproteins that bind PNA lectin (which binds galactose) and SBA and HPA lectins (N-acetylgalactosamine), UEA-I (fucose), and LcA (glucose and/or mannose). These findings suggest that the mucins secreted by ventral glands contain both N- and O-linked oligosaccharides. Ventral glands secrete higher quantity and more diverse mucous substances in the reproductive period, as confirmed by lectin-histochemical reactions. Based on these results, the major similarity between ventral cloacal glands and accessory mammalian glands, can be established with bulbourethral glands.

Animals↗

PubMed1999

Ultrastructure and lectin cytochemistry of the cloacal pelvic glands in the male newt Triturus marmoratus marmoratus.

The cloacal organ of Salamandridae species contains four glands: pelvic, dorsal, ventral, and Kingsbury's glands. Pelvic glands have been studied only by light microscopy with conventional methods, and consist of multiple tubular serous glands with a prismatic epithelium which contains numerous PAS positive secretory granules. The present report is an ultrastructural and lectin cytochemistry characterization of the pelvic glands of Triturus marmoratus marmoratus throughout the reproductive cycle. Our methods consisted of conventional electron microscopy, and colloidal-gold lectin cytochemistry of the following lectins: WGA, ConA, LcA, UEA-I, PNA, SBA, and HPA. In the prereproductive period, the glands showed a tall epithelium which consisted of two cell types, dark and clear cells, surrounded by elongated, myoepithelial cells. Both dark and clear cells showed the ultrastructural characteristics of secretory cells, and exhibited many secretory granules in the apical cytoplasm. Areas showing densely packed, degenerating cell organelles--which were not surrounded by membrane--were observed in the dark cells whereas the clear cells showed large heterolysosomes. In the postreproductive period the number of secretory granules decreased, the rough endoplasmic reticulum was less developed, and areas of degenerating organelles were absent. In addition, small basal cells appeared. The results of the lectin histochemistry study were similar in both reproductive periods. In the epithelial cells, the rough endoplasmic reticulum, the Golgi complex, and secretory granules exclusively labeled to ConA. In all cell types, the nuclei reacted to all lectins while the cytosol only reacted to LcA lectin. The ultrastructural and histochemical characteristics of the pelvic glands of T. marmoratus suggest that these glands could be homologous to the mammalian seminal vesicles and prostate.

Animals↗

PubMed1999

Immunohistochemical comparative analysis of transforming growth factor alpha, epidermal growth factor, and epidermal growth factor receptor in normal, hyperplastic and neoplastic human prostates.

Immunoreaction to TGF-alpha was limited to the basal epithelial cells of focal areas in the normal prostates. In benign prostatic hyperplasia (BPH) the immunostained areas were more widespread and immunolabelling was observed in both basal and columnar (secretory) cells of the epithelium. Some cells in the connective tissue stroma were also stained. In prostatic adenocarcinoma, epithelial immunostaining was even more extensive and intense than in BPH, and some stromal cells were also stained. Epidermal growth factor (EGF) immunostaining was only present in some basal cells in normal prostates. In BPH, this immunoreaction was strong in the basal cells and even stronger in the secretory cells. In prostatic cancer, the intensity of epithelial cell immunoreactivity was intermediate between that of normal prostates and that of BPH specimens. EGF-receptor immunostaining was focal and located in the basal cells in normal prostates. In BPH, labelling was also localized in basal cells but extended to wider areas. Some stromal cells appeared weakly labelled. In the prostatic carcinoma, both basal and columnar cells appeared stained and the number of immunolabelled stromal cells was higher than in BPH. The results presented suggest that, in normal conditions, EGF and TGF-alpha act as autocrine growth factors for the basal cells of the prostatic epithelium. In BPH this action is maintained and, in addition, the columnar cells start to secrete both factors which are bound by the basal cell receptors, giving rise to a paracrine regulation which probably overstimulates basal cell proliferation. In prostatic carcinoma, besides these regulatory mechanisms, the acquisition of EGF-receptors by the secretory cells develops an autocrine regulation which might induce their proliferation.

Adenocarcinoma↗

PubMed1999

Alpha-actinin in different invertebrate muscle cell types of Drosophila melanogaster, the earthworm Eisenia foetida, and the snail Helix aspersa.

The presence and distribution of alpha-actinin has been studied in several invertebrate muscle cell types. These comprised transversely striated muscle (flight muscle) from the fruit fly Drosophila melanogaster, transversely striated muscle (heart muscle) from the snail Helix aspersa, obliquely striated muscle (body wall muscle) from the earthworm Eisenia foetida, smooth muscle (retractor muscle) from H. aspersa, and smooth muscle (outer muscular layer of the pseudoheart) from E. foetida. The study was carried by means of Western blot analysis, ELISA, and immunohistochemical electron microscopy, using anti alpha-actinin antibody. Immunoreaction for a protein with the same molecular weight as that of mammalian alpha-actinin was detected in all muscle types studied, although the amount and intensity of immunoreaction varied among them. In the insect muscle, immunolabelling was found along the whole Z-line. In both the transversely striated muscle from the snail and the obliquely striated muscle from the earthworm, immunolabelling did not occupy the whole Z-line but showed discontinuous, orderly arranged patches along the Z-line course. In the two smooth muscles studied (snail and earthworm), immunolabelling was limited to small patches which did not show an apparently ordered distribution. Since it is assumed that alpha-actinin is located at the anchorage sites for actin filaments, present observations suggest that, only in the Drosophila muscle, actin filaments are parallelly arranged in all their course, whereas in the other invertebrate muscles studied these filaments converge on discontinuously distributed anchorage sites.

Actin Cytoskeleton↗

PubMed1999

A lectin histochemistry comparative study in human normal prostate, benign prostatic hyperplasia, and prostatic carcinoma.

The partial oligosaccharide sequences of glycoconjugates and the nature of their glycosidic linkages were investigated in normal human prostate, benign prostatic hyperplasia (BPH) and prostatic carcinoma by means of lectin histochemistry, using light microscopy and Western blot analysis. The labeling pattern of BPH differed from that of normal prostate in having more intense staining with DSA, HPA, UEA-I and AAA, and in showing lesser staining with WGA and SBA. Prostatic carcinoma differed from normal prostates in displaying the more intense labeling with PNA, DSA, SBA, DBA, UEA-I and AAA, and in having lesser labeling with WGA. The main differences in labeling pattern between prostatic carcinoma and BPH were that the latter specimens showed more marked staining with PNA, DSA, DBA, SBA, UEA-I and AAA, and lesser staining with WGA and HPA. The staining patterns of SNA, MAA, ConA, LCA and GNA were similar in all three groups of specimens. For most of the lectins studied, including those showing a similar immunohistochemical staining in the three groups of specimens studied, the Western blot analysis showed differences in the banding pattern among normal, hyperplastic, and carcinomatous prostates. Present results suggest that the glycosylation of proteins was modified in both BPH and prostatic carcinoma. In BPH a strong expression of N-acetylgalactosamine residues occurred, while in prostatic carcinoma an increase of sialic acid, galactose and fucose residues was observed. No changes in mannose residues were detected.

Adult↗

PubMed1999

The hatching gland cells of trout embryos: characterisation of N- and O-linked oligosaccharides.

A histochemical, light and electron microscopy study of the hatching gland cells (HGCs) in incubated 50-d-old trout embryos is reported. The distribution of carbohydrate residues in the glycoconjugates of these cells was studied by means of a battery of 13 different lectins conjugated with horseradish peroxidase (PNA, ConA, LCA, WGA, SBA, UEA-I, HPA, DBA) or digoxigenin (DSA, MAA, AAA, SNA, GNA). Identification of N- and O-linked oligosaccharides in HGCs was performed by application of both chemical and enzymatic treatments. Present results suggest that HGCs are seromucous cells which store both high choriolytic enzyme (HCE) and low choriolytic enzyme (LCE), and that their cytoplasmic granules, endoplasmic reticulum and Golgi complex contain additional sialic acid-rich glycoproteins. The negative charge of these glycoproteins might be responsible for the rapid expansion of mucin to form a highly hydrated gel, which would facilite the action of these enzymes in programmed cell death and might play a major role during the morphogenic events.

Animals↗

PubMed1998

Lectin histochemistry study in the human vas deferens.

The oligosaccharide sequences of glycoconjugates in the normal human vas deferens and the nature of the saccharide linkage were studied by lectin histochemistry. The cytoplasm of all epithelial cell types (principal cells, basal cells, and mitochondria-rich cells) and luminal contents reacted positively with WGA, MAA, PNA, DSA, LTA, UEA-I, AAA, and ConA. The reaction was more intense in the stereocilia of principal cells. Cytoplasmic staining was diffuse except for PNA and DSA labeling which was limited to the apical cytoplasm and stereocilia of columnar cells. The cytoplasm of all cell types also reacted diffusely with HPA, although staining was weak and was not observed in the stereocilia. Positive reaction with SBA only was encountered in the stereocilia of principal cells. SNA, LTA, and DBA were unreactive. GNA-labeling showed a granular distribution in the supranuclear cytoplasm of columnar epithelial cells. Reactions with MAA, PNA, DSA, AAA, HPA and SBA disappeared after the beta-elimination reaction. Reactions with WGA and UEA-I decreased after beta-elimination or Endo-F digestion. Reactions with ConA and GNA were suppressed by Endo-F digestion. Reactions with PNA, HPA, and SBA increased after desialylation. Of all the lectins that label the luminal contents of the vas deferens, only UEA-I was not found in the luminal contents of seminiferous tubules and epididymis and, thus, this lectin would probably bind to glycoproteins secreted by the vas deferens. The chemical treatments used suggest that this secretion contains fucose residues located in both N- and O-linked oligosaccharides. The other lectins may label secreted proteins, but also structural proteins or proteins reabsorbed from the luminal fluid. The lectin- binding pattern of mitochondria-rich cells in the vas deferens differed from that found in the epididymis.

Adult↗

PubMed1998

Lectin histochemistry of the human testis.

The oligosaccharide sequences of glycoconjugates and the nature of the saccharide linkage were investigated in normal human testes by means of lectin histochemistry studies, at light and electron microscopy levels. Reaction to WGA was intense in the seminiferous epithelium and interstitium. MAA showed light reactivity in all cell types of the human seminiferous epithelium, the lamina propria and Leydig cells. UEA-I lectin labelled the lamina propria intensely and the seminiferous epithelium and Leydig cells slightly. A slight reaction to AAA was found in the seminiferous epithelium and in Leydig cells. ConA was labelled in Sertoli cells, germ cells and Leydig cells. The reaction to GNA lectin was similar although less intense. PNA labelling was slight in Sertoli cells, spermatogonia, and Leydig cells, and more intense in spermatocytes, spermatids and peritubular cells. Reaction to DSA was intense in the seminiferous epithelium and Leydig cells. HPA labelled all cell types in the seminiferous epithelium and Leydig cells slightly, and labelled peritubular cells intensely. SBA lectin showed a strong reaction in spermatids and a slight reaction in the lamina propria. The reactions to SNA, LTA, and DBA were negative in all testicular cell types. After beta-elimination pre-treatment, MAA, UEA-I, AAA, PNA, DSA, HPA and SBA reactions were all negative. Endo F/PNGase digestion suppressed reactivity to ConA y GNA. Staining for WGA decreased with Endo F/PNGase digestion and also after beta-elimination. Desialization increased reactivity to PNA, SBA and HPA lectins. These results indicate that the terminal sequences of oligosaccharide side-chains in spermatocytes and, principally, in spermatids are: fucose, mannose, Neu5Ac2,3Gal1,3GalNAc, Gal1,3GalNAc, Gal1,4GlcNAc, Neu5AcGalNAc and GalNAc (in O-glycosylated proteins); mannose (in N-glycosylated proteins) and GlcNAc (in both protein types). A sialic acid residue is added to galactose and GalNAc residues. Present findings also indicate that Sertoli cell glycoproteins are similar to those of spermatids, and that the terminal sugar residues in Leydig cells are GlcNAc, fucose, mannose, Neu5Ac2,3Gal1,3GalNAc, Gal1,3GalNAc, and Gal1,4GlcNAc. The lectin pattern of the lamina propria suggests the presence of GlcNAc, galactose, fucose and GalNAc.

Adult↗

PubMed1998

Identification of N- and O-linked oligosaccharides in the human epididymis.

The oligosaccharide sequences of glycoconjugates in the human normal epididymis and the nature of linkages were studied with lectin histochemistry. The usual terminal sequences of oligosaccharide side chains in epithelial cell secretions were Neu5Ac2,3Galbeta1,3GalNAc; SO4Galbeta1,3GalNAc; and Galbeta1,4GlcNAc, and they were mainly found in O-linked glycoproteins. The lectin pattern of mitochondria-rich cells differed from that of principal cells.

Adult↗

PubMed1998

Transforming growth factor beta 1 and its receptor types I and II. Comparison in human normal prostate, benign prostatic hyperplasia, and prostatic carcinoma.

An immunohistochemical and semiquantitative comparative study of transforming growth factor beta 1 (TGF-beta 1) and its receptor types I (TGF-beta RI) and II (TGF-beta RII) was carried out in normal prostates and in the prostates from men with benign prostatic hyperplasia (BPH), and men with prostatic adenocarcinoma. Immunoreaction to TGF-beta 1 was limited to the basal epithelial cells in the normal prostates. Some cells in the connective tissue stroma were also stained. In BPH immunolabelling was also observed in columnar (secretory) cells of the epithelium. In prostatic adenocarcinoma, all epithelial cell types were intensely immunostained. Some stromal cells were also stained. Immunostaining to TGF-beta RI was only present in the basal cells in normal prostates. In BPH, this immunoreaction was found in the whole epithelium and in some stromal cells. In prostatic cancer, the immunostaining pattern for this receptor was similar to that of BPH but more intense in the epithelial cells. Immunoreactivity to TGF-beta RII appeared in some basal cells and some scattered columnar cells of the normal prostate epithelium. In the BPH sections, this pattern was maintained, and a weak immunolabelling was also observed in the stroma. In prostate cancer, all epithelial cells appeared intensely labelled. In the stroma, immunolabelling was similar to that of the BPH specimens. The results of the present study suggest that, in normal prostates, only the basal cells of the epithelium possess both receptor types, and hence can transduce TGF-beta 1 signal intracellularly. The basal cells can also secrete this growth factor which would act as an autocrine inhibitory growth factor for them. In addition, TGF-beta 1 is secreted in some zones by stromal cells, acting then as a paracrine growth factor for basal cells in those areas. In BPH, in addition to the basal cells, some secretory columnar cells also secrete TGF-beta 1 and possess both types of TGF-beta 1 receptors, and thus, both epithelial cell types are susceptible to TGF-beta 1 action. Since both receptor types are also present in some stromal cells, these cells also perform an autocrine secretion, in addition to their paracrine secretion to the epithelial cells. TGF-beta RIIs seem to be more numerous than TGF-beta RIs and this lead us to hypothesize that these incomplete receptors might be a protection against the inhibition caused by TGF-beta 1 action. In prostatic carcinoma all cell types display the same characteristics as in BPH, although both receptor types are found in similar numbers, and thus, the above mentioned protection would not occur.

Adenocarcinoma↗

PubMed1997

Immunocytochemical and quantitative study of the tunica albuginea testis in young and ageing men.

A light and electron microscope immunohistochemical study of the tunica albuginea from both young and elderly men was carried out to determine the distribution of the cells that contain actin, vimentin and/or desmin, and to evaluate the possible variations with ageing by means of quantitative studies. Testicular volume and testicular parenchyma volume decreased significantly with age whereas the tunica albuginea volume remained unchanged. These results agree with the scanty quantitative changes observed in the testicular connective tissue with age, and the notion that age-related changes in testicular volume are principally restricted to the seminiferous tubules. Three connective tissue layers could be distinguished in the tunica albuginea in both young and elderly men. The middle and inner layers increased in width with age while the width of the outer layer decreased. The average width of the tunica albuginea increased significantly with ageing. The tunica albuginea of young men and elderly men presented two types of fusiform cells: (1) fibroblast-like cells, which immunoreacted to actin and vimentin, but not to desmin; and (2) myoid cells, which immunoreacted to actin, vimentin and desmin. In both young men and elderly men, the total number of desmin-positive cells (myoid cells) was significantly lower than that of fibroblasts. However, the total number of desmin-positive cells was significantly increased in ageing men. In young testes, desmin-positive cells were more abundant in the outer layer of the tunica albuginea, whereas in elderly men these cells predominated in the middle layer. The increased desmin immunoexpression in the tunica albuginea of ageing men contrasts with the decrease in desmin immunoreaction in other myoid cells of the testis, the peritubular myoid cells, but only in seminiferous tubules that showed severe germ cell depletion. This suggests that changes in intermediate filament immunoexpression in peritubular cells are focalised, and thus, under local control, whereas changes in the tunica albuginea cells are generalised and possibly related to factors also affecting the connective tissue in other organs.

Actins↗

PubMed1997

Intermediate filaments in the Sertoli cells of the ageing human testis.

The presence and distribution of intermediate filaments (vimentin, keratin, desmin) was studied in the Sertoli cells of elderly men by means of quantitative immunohistochemical methods. Sertoli cells from young men showed moderate immunogold labelling to vimentin throughout the entire cytoplasm between the cell organelles in tubules showing complete spermatogenesis. Immunogold particles were more numerous in the perinuclear cytoplasm and beneath the plasma membrane in all its faces. The testes from elderly men showed different tubule types; some showed complete spermatogenesis and a normal lamina propria, while others had spermatogenic arrest at different levels (spermatids, spermatocytes, spermatogonia). The immunohistochemical reaction to vimentin in the Sertoli cells of tubules with complete spermatogenesis (type a) was similar to that in the cells of young men. In the Sertoli cells of severely damaged tubules (type b) the immunohistochemical reaction was more intense and immunogold particles extended in similar proportions throughout the whole cytoplasm. When immunolabelling intensity was compared between the three groups of tubules, by counting the number of immunogold particles per square micrometre of cytoplasm, it was found to be significantly higher (P < or = 0.05) in type b tubules of elderly men than either in tubules of young men or in type a tubules of elderly men. Since the average cell surface of Sertoli cells was similar in all tubule types, these data suggest that an actual vimentin increase occurs in Sertoli cells of germ-cell-depleted tubules. Sertoli cell immunogold labelling to keratin was found neither in young men nor in type a tubules of ageing men, whereas a positive immunohistochemical reaction was observed in the Sertoli cells of type b tubules of elderly men. Immunogold particles were localized mainly in the perinuclear cytoplasm, and beneath the lateral and basal cell surfaces. The observation of vimentin increase and keratin re-expression in ageing Sertoli cells only in germ-cell-depleted tubules suggests that the changes in intermediate filaments are related to the local factors associated with completion of spermatogenesis, causing functional changes in Sertoli cells.

Adult↗

PubMed1997

Immunocytochemical electron microscopic study and western blot analysis of myosin, paramyosin and miniparamyosin in the striated muscle of the fruit fly Drosophila melanogaster and in obliquely striated and smooth muscles of the earthworm Eisenia foetida.

Miniparamyosin is a paramyosin isoform (55-60 kDa) that has been isolated in insects (Drosophila) and immunolocalized in several species of arthropods, molluscs, annelids and nematodes. In this study, the presence and distribution of this protein, in comparison with that of paramyosin and myosin, has been examined in the striated muscle (tergal depressor of trochanter) of Drosophila melanogaster, and the obliquely striated muscle (body wall) and the smooth muscle (outer layer of the pseudoheart) of the earthworm Eisenia foetida by means of immunocytochemical electron microscopic study and Western blot analysis miniparamyosin paramyosin and myosin antibodies from Drosophila. In the striated muscle of D. melanogaster, the three proteins were immunolocalized along the length of the thick filaments (A-bands). The distribution of immunogold particles along these filaments was uniform. The relative proportions miniparamyosin/paramyosin/myosin (calculated by counting the number of immunogold particles) were: 1/10/68. In the obliquely striated muscle of E. foetida, immunoreactions to the three proteins were also found in the thick filaments, and the relative proportions miniparamyosin/paramyosin/myosin were 1/2.4/6.9. However, whereas the distribution of both myosin and miniparamyosin along the thick filament length was uniform, paramyosin immunolabelling was more abundant in the extremes of thick filaments (the outer zones of A-bands in the obliquely striated muscle), where the thick filaments become thinner than in the centre (the central zone of A-bands), where these filaments are thicker. The relative proportions of paramyosin in the outer and of paramyosin in the central zones of A-bands were 4/1. This irregular distribution of paramyosin along the thick filament length might be actual but it may also be explained by the fusiform shape of thick filaments in the earthworm: assuming that paramyosin is covered by myosin, paramyosin antigens would be more exposed in the tips than in the centre of thick filaments. If miniparamyosin is, in turn, covered by paramyosin, the exposure of miniparamyosin antigens would be low even in the tips of thick filaments, and this might explain the scanty immunoreaction observed for this protein and the absence of a higher number of immunogold particles in the extremes of thick filaments. The distribution of the three proteins in the earthworm smooth muscle was as in the obliquely striated muscle, although the proportions miniparamyosin/paramyosin/myosin were 1/1.5/5.2; this is, immunoreactions to paramyosin and miniparamyosin were lower than in the obliquely striated muscle.

Animals↗

PubMed1997

Immunocytochemical and quantitative study of actin, desmin and vimentin in the peritubular cells of the testes from elderly men.

A quantitative immunohistochemical study using light and electron microscopy was carried out to evaluate the morphological and quantitative distribution of the peritubular cells that immunoreact with actin, vimentin and desmin, alone or in combinations, in normal adult testes and the changes in these cells in elderly men. Seminiferous tubules in ageing testes were classified in three groups according to the degree of lamina propria thickening due to tubular sclerosis: group I, < 8 microns; group II, 8.1-12 microns; and group III, > 12.1 microns. The number of peritubular cells per cross-sectioned tubule increased from group I to group III tubules. However, no significant differences between ageing men and controls were found in the total number of peritubular cells per testis. Most peritubular cells of control testes and of group I and group II tubules displayed immunoreactivity to actin. The peritubular cells in the outermost layers of group III tubules showed no or scanty reaction. The number of actin-immunostained cells per cross-sectioned tubule decreased (P < 0.05) with tubular sclerosis. The total number of these cells per testis was significantly lower (P < 0.05) in elderly men. A narrow band around the seminiferous epithelium immunostained for desmin in control testes and group I tubules. These cells also immunoreacted to actin and vimentin. In group II and, principally, in group III tubules, only isolated peritubular cells were immunostained for desmin. The number of desmin-immunostained cells per cross-sectioned tubule decreased with tubular sclerosis and the total number per testis was also lower in elderly men. Vimentin immunostaining was observed in most peritubular cells in all tubule groups; these cells also immunoreacted to actin. Vimentin and desmin co-localized only in the inner peritubular cell layers. The number of vimentin-immunostained cells per cross-sectioned tubule increased with the degree of tubular sclerosis but the total number of these cells per testis did not differ significantly between control and ageing testes.

Actins↗

PubMed1997

Immunocytochemical electron microscopic study and Western blot analysis of caldesmon and calponin in striated muscle of the fruit fly Drosophila melanogaster and in several muscle cell types of the earthworm Eisenia foetida.

Caldesmon and calponin are two proteins that are characteristic of vertebrate smooth muscle. In invertebrates, caldesmon has only been studied in some molluscan muscles, and no previous references to calponin have been found. The aim of this paper was to investigate the presence and distribution of caldesmon and calponin in several invertebrate muscle cell types, classified according to their ultrastructural pattern: transversely striated muscle (flight muscle from Drosophila melanogaster), obliquely striated muscle (muscular body wall and inner muscular layer of the pseudoheart from the earthworm Eisenia foetida), and a muscle of doubtful classification which seems to be intermediate between smooth muscle and obliquely striated muscle (outer muscular layer of the pseudoheart, from E. foetida), using electron microscopy immunocytochemistry and Western blot analysis. Immunoreactions to both caldesmon and calponin were observed in the outer muscular layer cells from the earthworm pseudoheart but neither in the transversely striated muscle of D. melanogaster nor in the obliquely striated muscle from the earthworm. Present findings suggest that caldesmon- and calponin-like proteins are also present in invertebrate muscle cells, but only in those that are ultrastructurally similar to the vertebrate smooth muscle cells. Since discrepancies in the classification of some invertebrate muscles are common in the literature, the use of distinctive markers, such as troponin, caldesmon and calponin may improve our understanding of the nature and properties of many invertebrate muscles showing an ultrastructural pattern that does not resemble any of the classic muscle types.

Animals↗

PubMed1997

Nebulin-like protein in the earthworm Eisenia foetida. Immunocytochemical electron microscopic study and western blot analysis of several muscle cell types.

Nebulin is a giant protein (500-900 kDa), which has been reported only in the skeletal muscle (not in cardiac muscle) of vertebrates. The possible presence and distribution of nebulin-like proteins in obliquely striated muscles (body wall and inner muscular layer of the pseudoheart) and smooth muscle (outer muscular layer of the pseudoheart) from the earthworm Eisenia foetida have been examined by means of Western blotting analysis and immunoelectron microscopy, using antibodies against mouse nebulin. The results were compared with those obtained in skeletal, cardiac and smooth muscles of the mouse. In the mouse, immunoreaction to nebulin was observed only in the skeletal muscle and extended along the length of the thin filament. In the earthworm, immunoreaction to a nebulin-like protein was found in the muscle of the body wall and the inner muscular layer of the pseudoheart, but not in the outer muscular layer of the pseudoheart. By electron microscopy, immunolabeling to this protein was observed along the whole length of the thin filament. Western blotting analysis of this nebulin-like protein showed a single band at an estimated molecular mass between 350 and 450 kDa that is slightly lower than that of mouse skeletal muscle nebulin.

Animals↗