Cytochemical characterization of cuprolinic blue-stained proteoglycans in the epithelial-stromal interface of the guinea pig lateral prostate

Diabetes induces stromal remodelling and increase in chondroitin sulphate proteoglycans of the rat ventral prostate

Extracellular matrix (ECM) remodelling is an important process involved in prostate cancer progression. Alterations in ECM caused by diabetes in different tissues such as kidney is well described; however, it is poorly investigated in prostate. The aim of this study was to evaluate changes in ECM of rat prostate showing gland atrophy caused by diabetes and their implications in development of malignant lesions. Diabetes was induced in Wistar rats using alloxan (45 mg/kg bw). After 90 days of diabetes onset, animals were killed and ventral prostate was removed and prepared for light microscopy following immunoreaction for fibronectin, chondroitin sulphate and Picrossirius staining for collagen fibres. Proteoglycans (PG) were identified at transmission electron microscopy after fixation with Cuprolinic Blue. Diabetes led to a thickening of 25% in the acinar basement membrane accompanied by increase and disorganization of its proteoglycans (P1). Three additional populations of prostatic stromal PGs were identified: collagen fibril linked (P2) and interstitial (P3) and (P4) PGs. Diabetes increased P3 and mainly P4 which had higher dimension and accumulated around the smooth muscle cells. In addition, an increase in chondrotin sulphate (33%, mainly in sites where P4 were noted) and collagen (44%) was noted in diabetic rats, whereas fibronectin did not change. Atrophic changes observed in rat ventral prostate after diabetes are accompanied by stromal remodelation related to increase in collagen and chondroitin sulphate proteoglycans. Thus, diabetes can promote a stromal microenvironment rich in elements that could favour cell migration, proliferation and pathological process.

Extracellular matrix of the human aortic media: an ultrastructural histochemical and immunohistochemical study of the adult aortic media

Aortic distensability is the key to normal aortic function and relates to the lamellar unit in the media. However, the organization of the extracellular matrix components in these lamellar units, which are largely responsible for the distensability, is insufficiently known, especially in the human. We therefore performed a detailed ultrastructural analysis of these components. Thoracic aortas of 56 individuals (age 45-74 years), none of whom suffered from aortic disease, were studied by immunoelectron microscopy of elastin, collagen types I, III, IV, V, and VI, fibronectin, and fibrillin-1, and by ultrastructural histochemistry of proteoglycans, which were further characterized by enzymatic digestion. The elastic lamellae were closely associated with thick collagen fibers containing types I, III, and V collagen. Between these collagen fibers, numerous complex, circumferentially oriented streaks of elastin protruded from the lamellae. In contrast to what is usually reported in the aortas of experimental animals, the smooth muscle cells preferentially adhered to these ill-defined streaks rather than directly to the solid lamellae. Fibrillin-1- and type VI collagen-containing bundles of microfibrils (oxytalan fibers) were also involved in the smooth muscle cell-elastin contact. The smooth muscle cells were invested by basal lamina-like layers connecting them to each other as well as to the oxytalan fibers. Unexpectedly, these layers were abundantly labeled by anti-fibronectin, whereas type IV collagen, a specific basement membrane component, was mainly found in larger, flocculent deposits. The proteoglycans present were collagen-associated dermatan sulfate proteoglycan, cell-associated heparan sulfate proteoglycan, and interstitial chondroitin sulfate proteoglycan. Our observations demonstrate that the extracellular matrix in the human aorta is extremely complex and therefore differs from most descriptions based on experimental animals. They serve as reference for future studies on aortic diseases, such as aneurysmas and dissections.

Influence of testosterone on chondroitin sulphate proteoglycan in the rat prostate

There are recognized interactions between prostatic stromal and epithelial cells. These interactions may be influenced by the composition of the extracellular matrix, which is composed of proteins such as collagen, laminin, fibronectin, and proteoglycans (PGs) such as chondroitin sulphate proteoglycan (CSPG). In our continuing studies on prostate biology, we examined the three lobes of the normal adult rat prostate, i.e., ventral, dorsal, and lateral, for CSPG by indirect immunofluorescence, using an immunospecific monoclonal antibody (CS-56) for the chondroitin sulphate (CS) moiety of the PG. Staining of the prostate sections with CS-56 antibody followed by labelling with IgG fluorescein isothiocyanate conjugate indicated strong fluorescent signals associated with the ventral lobe basement membrane. The signal was stronger and more continuous in the distal acini than in the proximal acini. The staining of the dorsal and lateral lobes was less intense than that of the ventral lobe. Following castration of the rats, the basement membrane staining became discontinuous. Androgen replacement by administration of testosterone propionate (TP) reversed the effects of castration. Quantification of the total CS content showed decreases of about 60% in the ventral and lateral lobes after castration. TP administration for 14 days increased the total CS content several fold above the values for castrated rats in all lobes. The results demonstrated that CS content was significantly higher for TP-treated animals, suggesting that the expression of prostate CSPG is regulated by androgens. This approach should be useful in the study of the extracellular matrix in prostate biology.

Proteoglycans associated with the ciliary zonule of the rat eye: a histochemical and immunocytochemical study

The structural organization of integral and associated components of the ciliary zonule is still not fully understood. The present study is to localize and characterize the proteoglycans associated with the ciliary zonule of the rat eye by Cuprolinic blue (CB) staining and immunocytochemistry. After CB staining, the proteoglycans appeared as electron dense elongated rodlets and were localized with the zonular fibers. They were seen lying on the periphery of the zonular fibers or along the length of the individual fibrils. Most of the CB rodlets had a size of 60-170 nm long (average 130 nm) and 25 nm wide. Smaller CB rodlets measuring 25-60 nm long (average 45 nm) and 12 nm wide were sometimes found associated with the individual zonular fibrils. The CB rodlets were removed after chondroitinase ABC or chondroitinase AC treatment, but were resistant to heparitinase, nitrous acid, keratanase or Streptomyces hyaluronidase digestions. The ciliary zonule was also immunostained with three monoclonal antibodies: 2-B-6 specific for chondroitin 4-sulfate, 3-B-3 for chondroitin 6-sulfate and 1-B-5 for unsulfated chondroitin, using indirect immunoperoxidase or immuno-colloidal gold methods. The zonular fibers were immunoperoxidase stained and immunogold labeled by 2-B-6, but were not reactive to 3-B-3 and 1-B-5. The results demonstrate that chondroitin sulfate proteoglycan is associated with the ciliary zonule of the rat eye.

Glycosaminoglycans of guinea pig prostate fibromuscular stroma: influence of estrogen and androgen on levels and location of chondroitin sulfate

The effects of aging and hormone manipulation on the glycosaminoglycan (GAG) content of prostatic stroma in guinea pigs were investigated. Total GAG and individual GAG classes (chondroitin, dermatan, and heparan sulfates, and hyaluronic acid) were measured biochemically in stromal extracts. Chondroitin sulfate was also measured and localized by video image analysis of immunocytochemically-stained tissue sections. The weight and total GAG (uronic acid) content of prostatic stroma increased between the ages of 2 weeks and 2 years by 7-8-fold and 4-5-fold respectively. GAG concentration per unit weight of stroma declined 4-fold during puberty and remained essentially unchanged thereafter. Similar results were obtained for each of the GAG classes. The decreases in GAG concentration were associated with a 3-fold increase in the size of the smooth muscle cells of the prostatic stroma during puberty. Hormonal control of GAG deposition in the prostatic stroma was investigated by steroid replacement in prepubertally-castrated animals. Administration of dihydrotestosterone (DHT) to castrate animals for 6 weeks resulted in significantly reduced concentrations of stromal uronic acid, compared with untreated castrate animals (P < 0.05). The GAG levels post-DHT treatment were similar to those observed after pubertal development in sham-operated control animals. Estradiol treatment had the opposite effect to that of DHT, resulting in a significantly increased concentration of uronic acid compared with castrate animals (P < 0.05). These steroid-induced changes in stromal GAG deposition were mostly contributed to by chondroitin and dermatan sulfates. Combined treatment with DHT and estradiol resulted in stromal uronic acid concentrations similar to those of animals receiving DHT alone, indicating that the effect of DHT on stromal GAG deposition is dominant over the effects of estradiol. Morphometric measurement, using computer-assisted video image analysis of a chondroitin sulfate epitope in prostatic sections stained with a monoclonal antibody (6C3), supported the biochemical data. Stereometric profiles across several sectioned glands demonstrated that chondroitin sulfate was confined to the periacinar basement membranes of the prostatic stroma in all groups except the estradiol-treated castrate animals, where the immunostaining extended from the periacinar basement membrane throughout the fibromuscular stroma. Treatment of castrate animals with estradiol alone also induced a physicochemical change in the chondroitin sulfate molecule, resulting in reduced electrophoretic mobility. In summary, this study identifies changes in the quantity, structure, and localization of chondroitin sulfate in the prostatic stroma of estradiol-treated guinea pigs. Furthermore, estradiol and DHT have opposing effects on the level of chondroitin and dermatan sulfate expression in the prostatic stroma.

Long-spacing collagen and proteoglycans in pathologic tissues

The presence of proteoglycans in fibrous long-spacing collagen (FLSC) was assessed in various pathologic tissues using the highly selective proteoglycan stains cuprolinic blue and polyethyleneimine. Two types of FLSC could be distinguished: one that contained proteoglycans and one that did not. The conditions in which these types occurred suggested a completely different physiologic significance. Also, their morphologies were different: The FLSC containing proteoglycans constituted compact, often fusiform structures long known in diagnostic electron microscopy as Luse bodies. In accordance with the literature, this compact type of FLSC was found especially in schwannomas and other neurogenic tumors. Enzymatic digestion experiments indicated that the proteoglycan present was dermatan sulfate proteoglycan. The average periodicities measured ranged from 101 to 147 nm. The type of FLSC lacking proteoglycans, on the other hand, formed dispersed aggregates. This dispersed FLSC had periodicities ranging from 79 to 103 nm (ie, just below those of the compact type). It was found only under circumstances in which there was high collagen breakdown and/or turnover. That dispersed FLSC is a marker for collagen degradation was further supported by its presence inside fibroblasts engaged in collagen phagocytosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Proteoglycans in male reproductive tract

Proteoglycans in male reproductive tract have been mainly characterized in testicular extracellular matrix and somatic cells. Heparan sulfate, chondroitin sulfate and hybrid chondroitin/heparan sulfate proteoglycans coexist within the testes. Their biological roles are not currently established, however, the molecular characterization of some of them is indicative that they might be involved in various regulatory processes during spermatogenesis.

Effects of p-nitrophenyl-beta-D-xylopyranoside (beta-D-xyloside) on the androgen-induced growth of the lateral prostate of the prepubertally castrated guinea pig

The aim of this study was to examine the effects of beta-D-xyloside (XYL), a compound which interferes with stromal proteoglycan (PG) synthesis, on androgen induced growth of the lateral prostate (LP). Young male guinea pigs were castrated at 3 weeks of age and divided into three groups 6 weeks after castration. In group one, the animals were injected subcutaneously daily with 80 mg/kg of XYL, followed 3 days later by a daily dose of 10 mg/kg of dihydrotestosterone (DHT) for 2 more weeks. The second group served as control and received DHT only. In the third group, animals were treated first with XYL, like those in group one, and then followed by DHT alone for 2 weeks to check reversibility of the XYL effect. At the end of the experiment, the lateral prostate was removed and processed for morphological and cytochemical examination. The results showed that XYL inhibited the DHT stimulated growth of the lateral prostate. The fibroblasts showed a dilated granular endoplasmic reticulum filled with granular substances. In the interstitial spaces, there was a drastic increase in Cuprolinic Blue (CB) positive filaments and polygonal granules believed to be PGs or glycosaminoglycans (GAGs). Their number was much greater than the control. The distribution and density of the collagen fibers appeared similar to the control. The secretory alveoli were lined by epithelium with few secretory granules of low electron density and a larger number of clear vesicles. There was a slight reduction in glycoconjugate reactivities in the epithelial cells. The lectin binding patterns and the structural features were comparable between the control and recovery groups, indicating the XYL effects were reversible. The results suggest that stromal PG biosynthesis may play a role in epithelial function and an altered stromal matrix would hamper the effects of DHT on the target organ.

Effects of cis-4-hydroxy-L-proline on the androgen-induced growth of the lateral prostate of the prepubertally castrated guinea pig

The present study examined the effects of cis-4-hydroxy-L-proline (CHP), a proline analog, on the androgen-induced growth of the lateral prostate of prepubertally castrated guinea pigs. Prepubertal male guinea pigs were castrated at the age of 3 weeks and allowed to recover completely before subjection to an experimental regime to alter the stromal collagen synthesis by CHP. The animals were kept on a special proline-deficient diet (PDD) for a week before the subcutaneous injection of CHP (200 mg/kg/day) for 3 days, followed by a combined injection of CHP and dihydrotestosterone (DHT) (10 mg/kg/day) for 10 days. Control animals were injected with saline and DHT only. At the end of the experiment, the lateral prostate was removed and examined by 1) conventional transmission electron microscopy (TEM), 2) staining of proteoglycans (PGs) by Cuprolinic Blue (CB) using the critical electrolyte concentration (CEC) method, 3) carbohydrate and lectin histochemistry, and 4) electron microscopy (EM) lectin-gold labelling. The results showed that the wet weight of prostate from CHP-treated animals was significantly lower than the control and recovery groups. The epithelium was low columnar with an obvious increase in intercellular spaces and number of basal cells. The glandular cells showed little secretory activity with a decrease in number of granular endoplasmic reticulum (GER) profiles, secretory granules, and a small Golgi apparatus. The stroma was composed of stromal cells separated by large intercellular spaces with very sparse collagen fibrils, and a decrease in stromal PGs especially those PGs normally associated with collagen fibrils. CHP treatment also caused perturbation and disorganization in the epithelial basement membrane. The results suggested that stromal collagen is essential in mediating the response of glandular cells to DHT stimulation. Defective stromal collagens hamper the responsiveness of prostatic gland to androgen.

Age-related changes of sulfated proteoglycans in the normal human trabecular meshwork

Ultrastructural changes in sulfated proteoglycans were studied in 12 pairs of normal eye-bank eyes (aged 1 day to 92 years), using the cationic dye, cuprolinic blue, in a 'critical electrolyte concentration'. Pretreatment of trabecular meshwork sections with various glycosaminoglycanases and nitrous acid served to characterize these proteoglycans. Three sizes of proteoglycan-cuprolinic blue (PG-CB) complexes were found in association with different extracellular matrix components. Small, thin PG-CB complexes were closely associated with collagen fibrils. Large, thick PG-CB complexes, although located close to collagen fibrils in a variety of places, were most commonly seen between the boundaries of the collagen bundles, where they were associated with fine filaments. Both types of collagen-associated PG-CB complexes contained chondroitin sulfate and dermatan sulfate, with dermatan sulfate predominant. Basal lamina-associated PG-CB complexes contained heparan sulfate. An age-related, progressive coalescence of collagen was found in normal trabecular meshwork in a statistically significant fashion; the regions of collagen coalescence were associated with a decrease of small, collagen-associated PG-CB complexes and an increase of a previously unrecognized matrix material. The measurement of areas of coalescence of collagen was used as an indirect indicator of small, collagen-associated PG-CB complex loss with age. Large collagen-associated PG-CB complexes and basal lamina-associated PG-CB complexes decreased from infant to young adult; no additional loss with age was found. Further studies will be needed to determine whether loss of sulfated PGs plays a role in increased aqueous outflow resistance that characterizes glaucoma.

Glycoconjugates of the lateral prostate of the guinea pig: a lectin histochemical study

The present study examined the glycoconjugates of the lateral prostate using a battery of lectins. The results indicated that the secretory epithelium was rich in mannose (Man), N-acetylglucosamine (GlcNAc), galactose (Gal), N-acetylgalactosamine (GalNAc), and complex oligosaccharides. Con A (concanavalin A), LCA (Lens culinaris agglutinin), PSA (Pisum sativum agglutinin), WGA (wheat germ agglutinin), PWM (pokeweed mitogen), RCA-I (Racinus communis isolectin I), and PHA-P (Phaseolus vulgaris agglutinin-P) reacted intensely with both epithelia and stroma, while SBA (soybean agglutinin) and PNA (peanut agglutinin), which bind to terminal Gal, GalNAc, and Gal beta 1,3 GalNAc appeared to be specific to the secretory epithelium. SBA and PNA were useful as markers in the study of the secretory function of the prostate gland. The present study has shown that the Golgi apparatus of prostatic epithelial cells was rich in fucose (Fuc), oligomers of GlcNAc, Gal beta 1,3 GalNAc, Gal, and Man containing glycoconjugates, indicating that the gland was actively involved in glycosylation. The present study has also shown that LTA (Lotus tetragonolobus agglutinin) is a good marker for the epithelial Golgi. PNA also bound to the epithelial basement membrane and the connective tissue in the lamina propria. The present study has thus established, for the first time, the glycoconjugate patterns in the lateral prostate of the guinea pig.