Immunolocalization of laminin, heparan‐sulfate proteoglycan, entactin, and type IV collagen in the rat anterior pituitary. I. An in vivo study

Vila-Porcile, Évelyne; Picart, R; Vigny, Marc; Tixier‐Vidal, A.; Tougard, Claude

doi:10.1002/ar.1092320405

Cited by 21 publications

(14 citation statements)

References 47 publications

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“…No intracellular organelles were stained. Whereas intracellular laminin-immunoreactivity has been demonstrated in adult tissues (Learkamolkarn & Abrahamson, 1992), other investigators have not described laminin-or collagen IV-immunoreactivity in epithelial cells (Laurie et al, 1982;Abrahamson, 1986;Grant & Leblond, 1988;Vila-Porcile et al, 1992). In the present experiments a few gold particles were also seen in the agarose matrix.…”

Section: Discussioncontrasting

confidence: 62%

Basal lamina formation by porcine thyroid cells grown in collagen- and laminin-deficient medium

1995

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Porcine thyroid cells isolated by dispase treatment were cultured in either (a) Matrigel, (b) agarose with the addition of different combinations of basic fibroblast growth factor and laminin, or (c) on agarose-coated dishes. The formation of follicles and the presence of a basal lamina was investigated by routine electron microscopy of Araldite-embedded material and by light and electron microscopical immunocytochemical detection of the basal lamina components, laminin and collagen type IV. After 10 days of culture in Matrigel or agarose, a basal lamina-like structure surrounded most follicles. Follicles of cells growing in agarose and overlaid with a medium containing thyrotropin and overlaid with a medium containing thyrotropin and fibroblast growth factor showed a fluorescent band at the basal side of the follicles after immunocytochemical staining with anti-laminin and anti-collagen antibodies. Routine electron microscopy showed that a basal lamina-like structure lined the outside of the follicle. This structure could be subdivided into a lamina lucida and a lamina densa. Electron microscopical immunogold labelling revealed that immunologically detectable laminin was confined to the lamina densa. These findings suggest that even in the absence of basal lamina components in the culture medium, thyroid cells are able to form follicles with a regular basal lamina when they are cultured in a three-dimensional environment.

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Section: Discussioncontrasting

confidence: 62%

Basal lamina formation by porcine thyroid cells grown in collagen- and laminin-deficient medium

1995

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“…The immunohistochemistry for CN-IV and LN in the control rat thyroid glands demonstrated the presence of a thin layer of BM enveloping each follicle and a fine network of capillary blood vessels, known to be specific to the endocrine organs, as described for the anterior pituitary glands [30]. In nodular lesions of type 2, the mesh ×170 (a, b); ×340 (c, d).…”

Section: Discussionmentioning

confidence: 95%

Alterations of basement membrane in di-isopropanolnitrosamine- induced carcinogenesis of the rat thyroid gland: an immunohistochemical study

Huang

Kobayashi

et al. 2000

Virchows Archiv

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Alterations of basement membrane (BM) in di-isopropanolnitrosamine (DIPN)-induced carcinogenesis of the rat thyroid gland were examined by means of immunohistochemical localization of collagen type IV (CN-IV), laminin (LN), and fibronectin (FN) in prenodular and nodular thyroid lesions, correlating with the morphogenesis and proliferative activity of these lesions. Adult male rats of the Wistar strain were injected s.c. in the back with DIPN, and the thyroid glands were removed at the 15th and 30th week of treatment. Each of 133 thyroid lesions was histochemically analyzed. The follicular epithelial BM as revealed by CN-IV and LN was discontinued or completely lost during the progression of thyroid lesions from pre-nodular to nodular lesions and finally overt carcinomas. At the same time, the BM of vascular endothelial cells demonstrated a loss of dense capillary networks of follicles, a sinusoidal dilatation and, predominantly in carcinomas, development of interstitial-type blood vessels. However, FN, which was hardly stained in the normal thyroid tissue, was remarkably deposited in the interstitium of invasive carcinomas. These observations strongly suggested that alterations of BM structure play a key role in the morphogenesis of rat thyroid tumors, and that the expression of FN is an important step in the invasive growth of thyroid tumors.

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“…Some suggest that this is related mainly to gonadotrophs [7], while others report immunoreactivity in all cells except somatotrophs [8]. Type IV collagen has also been localised [9], and fibronectin has been reported in folliculostellate cells [10]. In the human gland, laminin, type IV collagen and fibronectin have been reported in epithelial and endothelial basement membrane [11].…”

Section: Introductionmentioning

confidence: 99%

Organisation of basement membrane components in the human adult and fetal pituitary gland and in pituitary adenomas

et al. 1997

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Cell-matrix interactions undoubtedly have a role in the development and maintenance of the complex nonrandom structure of the human pituitary gland. We have extended previous studies by documenting the patterns of immunoreactivity for type IV collagen, laminin and fibronectin in the fetal gland, comparing these with the adult patterns. In both we have examined the differences between the anterior lobe and intermediate zone in an attempt to elucidate the apparent differences in functional response between corticotrophs in the two areas. We have also examined expression of these proteins in a series of pituitary adenomas. Finally, we have immunolocalised beta 4 integrin, a component of the alpha 6 beta 4 laminin receptor, in the adult gland and in adenomas. In the anterior lobe of the adult gland, type IV collagen and laminin were present in both epithelial and vascular basement membrane. Fibronectin was related to the basement membrane but showed a less continuous distribution. beta 4 Integrin was expressed on the basal aspects of pituitary cells, in association with laminin, suggesting that this did identify the alpha 6 beta 4 laminin receptor. In addition, immunoreactivity was present on the lateral margins of some pituitary cells, which might indicate a role in cell-cell adhesion. None of the proteins showed specific association with any particular cell type, suggesting that these specific interactions do not regulate differentiation. This pattern of expression had developed in the fetal gland by the second trimester, with expression relating to vessels preceding that in epithelial basement membrane. Type IV collagen, laminin and fibronectin were also expressed in epithelial and vascular basement membrane in the intermediate zone of the adult gland, and around Rathke's cleft in the fetal gland. However, the organisation differed, with larger groups of cells enclosed within a single basement membrane. Possible vascular connections demonstrated between the posterior lobe and the intermediate zone would permit access of posterior lobe hormones to this zone. Our data confirmed disruption of expression in pituitary adenomas, type IV collagen, laminin and beta 4 integrin having a mainly perivascular distribution, with more variable immunoreactivity for fibronectin.

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Immunolocalization of laminin, heparan‐sulfate proteoglycan, entactin, and type IV collagen in the rat anterior pituitary. I. An in vivo study

Cited by 21 publications

References 47 publications

Basal lamina formation by porcine thyroid cells grown in collagen- and laminin-deficient medium

Basal lamina formation by porcine thyroid cells grown in collagen- and laminin-deficient medium

Alterations of basement membrane in di-isopropanolnitrosamine- induced carcinogenesis of the rat thyroid gland: an immunohistochemical study

Organisation of basement membrane components in the human adult and fetal pituitary gland and in pituitary adenomas

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