288 research outputs found
Involucrin, but not filaggrin and Kdap mRNA, expression is downregulated in 3-D cultures of intact rat hair bulbs after calcium stimulation
The hair follicle consists of several distinctive epidermal cell layers. The hair root, which undergoes
keratinization, is surrounded by two sheaths: the inner root sheath (IRS) and the outer root sheath (ORS). The
ORS is continuous with the basal layer of the epidermis. Its cells do not keratinize in situ, unlike IRS. We have
previously demonstrated that keratinization of the ORS was prevented by contact with the IRS in hair follicle
mid-segments (i.e. fragments dissected from skin at the level above the hair bulb and below the opening of the
sebaceous gland duct) cultured on agarose layer. The purpose of this study was to determine whether the same
applies to the hair bulb. After isolation, intact bulbs or hair bulb-derived cells were incubated in suspension in
a low or high calcium medium. The level of mRNA for differentiation markers: involucrin, filaggrin, keratinocyte
differentiation associated protein and trichohyalin, was studied by RealTime PCR. We observed increased Ca2+
upregulated expression of involucrin, filaggrin, trichohyalin and Kdap in cultures of bulb-derived cells, but in
hair bulbs downregulation of involucrin and trichohyalin was observed. We concluded that the inner root sheath
exerts an inhibitory effect on the expression of involucrin and trichohyalin already in the hair bulbs. The observation
that downregulation of involucrin expression under Ca2+ influence occurs both in hair bulb and midsegments
could simplify future experiments, since their separation does not seem to be necessary. (Folia Histochemica
et Cytobiologica 2011, Vol. 49, No. 2, 335–343
Prostate secretory granules as a diagnostic aid in detecting small foci of prostatic adenocarcinoma
Influence of IGF1, TGFβ1, bFGF and G-CSF/M-CSF on the mRNA levels of selected matrix proteins, cytokines, metalloproteinase 3 and TIMP1 in rat synovial membrane cells
Introduction. We have previously observed that rat synovial membranes incubated in medium containing cartilage interstitial fluid (CIF) responded by changes in the expression of hyaluronan synthases (HAS1 and HAS2), collagen type I, versican, aggrecan, lubricin, matrix metalloproteinases 2 and 3 (MMP2 and MMP3), tissue inhibitors of metalloproteinases (TIMP1, 2 and 3), transforming growth factor β1 (TGFβ1), tumor necrosis factor (TNF), interleukin (IL) 1β and IL-6. The aim of the study was to evaluate the influence of particular cytokines found in CIF on the gene expression of extracellular matrix (ECM) proteins in synovial membrane cells.
Material and methods. Synovial membranes (SMs) were removed from the knee joints of inbred, male Lewis rats and incubated with insulin-like growth factor 1 (IGF1), TGFβ1, basic fibroblast growth factor (bFGF) and granulocyte- macrophage colony-stimulating factors (G-CSF and M-CSF), either individually or in the combinations TGFβ1/IGF1, TGFβ1/IGF1/bFGF or G-CSF/M-CSF. Next, total RNA was isolated and the studied genes’ expression was evaluated by real-time PCR.
Results. TGFβ1/IGF1 stimulated expression of HAS1, lubricin, collagen type I, aggrecan and TGFβ1, inhibited expression of MMP3 and TNF and had no effect on TIMP1 and IL-6 mRNA levels. TGFβ1/IGF1/bFGF stimulated the expression of HAS1, lubricin and TGFβ1 genes, inhibited the expression of TNF and had no effect of the expression of collagen 1, aggrecan, MMP3, TIMP1 and IL-6 genes. G-CSF/M-CSF stimulated the expression of aggrecan. TGFβ1, bFGF, and IGF1 applied individually exerted inhibitory effect on the expression of lubricin. TGFβ1 and bFGF inhibited expression of MMP3 and bFGF inhibited also the expression of aggrecan and TNF.
Conclusions. The response of the studied genes represents a resultant activity of all major cell types building the synovial membrane, i.e. highly specialized synovial fibroblasts, macrophages, epithelial cells and adipocytes. The results of our study can improve understanding of synovial membrane responses to the intraarticular injections of platelet-rich plasma (PRP) used for the treatment of joint ailments, since PRP contains factors which are also present in CIF
Venous outflow system in rabbit gastric mucosa
The purpose of this work was to compare the organisation of the gastric mucosal
venous system in larger animals, exemplified by rabbits, with that of the rat
and the hamster which we have described previously. Rabbits were given atropine
and hexamethonium followed by intravital ligation of all veins draining the
stomach, causing strong hyperaemia. The distribution of vessels was studied in
the non-mounted mucosa, in mounts of mucosa cleared in light mineral oil and
in paraffin or semi-thin plastic sections. We found that blood from rabbit gastric
mucosa is drained by collecting venules, running from the subepithelial layer
towards the muscularis mucosae. The collecting venules join the paramuscular
vessels parallel and adjacent to the muscularis mucosae. Neighbouring venules
form numerous arcade-like connections and gradually enlarge. Two venules and
an arteriole form triplets initially situated at the luminal face of the muscularis
mucosae and gradually passing onto its abluminal surface. In rats vascular triplets
were absent and the collecting venules drained into paramuscular vessels
joining submucosal veins. In hamsters both connections between paramuscular
vessels and submucosal veins and the passing of vascular triplets across muscularis
mucosae were observed. Contraction/relaxation of the muscularis mucosae
may regulate the amount of blood in the venous system of the mucosa and
change the intramucosal pressure, affecting movement of the tissue fluid and,
indirectly, the function of the gastric cells
Vessels involved in the venous outflow from glandular mucosa of hamster stomach
Blood from the glandular part of hamster gastric mucosa is drained by collecting
venules, running from the subepithelial layer towards lamina muscularis mucosae.
To visualise vessels involved in the venous outflow, hamsters were exposed
to atropine and subjected to intravital ligation of portal vein, causing strong
hyperaemia. Distribution of vessels and their connections were studied a) in
translucent, flat preparations of the glandular stomach, b) in thick sections of
glandular mucosa cleared in the mineral oil, and c) in semi-thin plastic or paraffin
sections. Collecting venules were drained by single vessels running parallel to
the lamina muscularis mucosae (paramuscular venules), which, in turn, joined
submucosal veins through openings in muscularis mucosae. Moreover, some
collecting and paramuscular venules discharged into venules belonging to vascular
triples composed of two venules and arteriole. The triplets were also parallel
to muscularis mucosae. Triplets did not form connections with submucosal
veins but passed on the abluminal surface of muscularis mucosae. Thus, some
structural elements involved in venous outflow from glandular gastric mucosa
differ from those in rats, in which vascular triplets were absent and all collecting
venules drained into single paramuscular vessels. Contraction/relaxation of muscularis
mucosae may regulate the amount of blood present in the venous system
of the mucosa and the diameter of venules. Rhythmical changes of the
latter could cause changes in intramucosal pressure, affecting movement of
tissue fluid in the mucosa and thus the function of gastric cells
Synovial membrane asks for independence
Synovial membrane is traditionally considered as a part of the joint capsule. It, however, differs from fibrous part of the capsule in development, structure, function, vascularisation, innervation and involvement in pathological processes. Moreover, in some areas, it even does not contact with the fibrous capsule. Thus, it appears that the synovial membrane should be considered as an independent organ and not as the lining of the joint capsule.
Preparation of rat synovial membrane for studies of cytokine secretion.
The objective of this work was to devise an in vitro system for studies on cytokine secretion by synovial membrane treated as a whole organ with various synoviocyte populations. Synovial membrane from knee joints of WAG rats was dissected and incubated in culture medium without serum for 4 - 48 h. The level of IL-1alpha was determined in synovial lysates and IL-6 in culture medium. The synovial membrane from left and right knee joint of the same rat produced similar amount of cytokines both in lysates and in the medium. Synovial membrane stimulated by LPS for 4 or 24 h gave significantly stronger cytokine response than the membrane from the opposite (control) knee. After 48 h incubation of synovial membrane drastic drop in cytokine level was noted, which indicated on deterioration of the membranes. The test may be useful in studies on factors affecting cytokine secretion by synoviocytes
Formation of synovial joints and articular cartilage
Chondrocytes differentiate from mesenchymal progenitors and produce templates(anlagen) for the developing bones. Chondrocyte differentiation is controlled bySox transcription factors. Templates for the neighbour bones are subsequentlyseparated by conversion of differentiated chondrocytes into non-chondrogeniccells and emergence of interzone in which joints cavitation occurs. A central rolein initiating synovial joint formation plays Wnt-14/beta-catenin signalling pathway.Moreover, bone morphogenetic proteins and growth and differentiation factorsare expressed at the site of joint formation. Joint cavitation is associated withincreased hyaluronic acid synthesis. Hyaluronic acid facilitates tissue separationand creation of a functional joint cavity. According to the traditional view articularcartilage represents part of cartilage anlage that is not replaced by bone throughendochondral ossification. Recent studies indicate, however, that peri-joint mesenchymalcells take part in interzone formation and that these interzone cellssubsequently differentiate into articular chondrocytes and synovial cells. Thus,anlage chondrocytes have a transient character and disappear after cessation ofgrowth plate function while articular chondrocytes have stable and permanentphenotype and function throughout life
Prostatic neuroendocrine cells and neuroendocrine differentiation in adenocarcinoma prostatae
Change in Localization of Alkaline Phosphatase and Mannosidase II by Colchicine Treatment of Primary Cultures of Fetal Rat Hepatocytes
We examined the changes in localization of alkaline phosphatase (ALP) and mannosidase II (man II), a Golgi marker, after colchicine treatment of primary cultures of fetal rat hepatocytes, using double immunofluorescence staining and confocal laser microscopy. In hepatocytes cultured in basal medium, ALP was localized in the perinuclear cytoplasm, and man II was observed in the Golgi region of the cytoplasm. When hepatocytes were cultured in dexamethasone-supplemented medium, ALP was also localized in the plasma membrane surrounding the bile canaliculus-like structure that was formed between adjacent cells. In hepatocytes cultured in the same medium containing colchicine, the structure of microtubules in the cytoplasm was lost, man II exhibited granular distribution scattering throughout the cytoplasm, and ALP was localized in coarse granular sites of the cytoplasm. However, ALP was not colocalized at the same sites as man II. The present study indicated that colchicine inhibits the dexamethasone-promoted translocation of ALP to the plasma membrane surrounding the bile canaliculus-like structure in primary cultures of fetal rat hepatocytes by disassembling microtubules and discomposing the Golgi complex
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