Identification and localization of lamina cribrosa cells in the human optic nerve head.

One of the central features of glaucoma is progressive cupping and excavation of the optic nerve head (ONH). Unmyelinated retinal ganglion cell (RGC) axons exit the eye through the ONH, which is supported by the lamina cribrosa (LC) consisting of plates of connective tissue with channels for bundles of RGC axons. The LC progressively remodels during glaucoma, but the cellular and molecular mechanisms responsible for this remodeling are poorly understood. Two major cell types have been isolated and cultured from the human ONH, which differ in their characteristics. Glial fibrillary acidic protein (GFAP) positive ONH astrocytes are the major cell type and are reactive in glaucoma. GFAP negative LC cells are the second major cell type isolated from the human ONH, and in contrast to ONH astrocytes, are α-smooth muscle actin (α-SMA) positive. Although a number of in vitro studies have been conducted with LC cells, to date there has been no direct evidence for these cells in situ in the human ONH. We used GFAP and α-SMA immunofluorescent staining of human eyes to clearly demonstrate the presence of not only ONH astrocytes within the human ONH, but also LC cells within the cribriform (e.g. laminar) plates/beams of the LC region. Both of these cell types likely play important roles in the homeostatic maintenance of the ONH and pathogenic changes that occur in primary open angle glaucoma (POAG).

Monascus purpureus-fermented rice inhibits tumor necrosis factor-α-induced upregulation of matrix metalloproteinase 2 and 9 in human aortic smooth muscle cells.

OBJECTIVES: Inflammation is associated with atherosclerosis. Cholestin (Monascus purpureus-fermented rice) contains a naturally occurring statin, which has lipid-modulating, anti-inflammatory and antioxidative effects. This study aimed to investigate the effects of Cholestin extract on the expression of matrix metalloproteinase (MMP)-2 and MMP-9 by tumor necrosis factor (TNF)-α-treated human aortic smooth muscle cells (HASMCs). METHODS: Zymography, reverse transcription polymerase chain reaction and immunoblot analyses were used for analysis of MMP expression of TNF-α-stimulated HASMCs. Gel shift assay was used for analysis of transcription factor nuclear factor-κB (NF-κB) activation. Intracellular reactive oxygen species (ROS) generation was also analysed. KEY FINDINGS: The supplement of HASMCs with Cholestin extract significantly suppresses enzymatic activities of MMP-2 and MMP-9 in TNF-α-stimulated HASMCs. RT-PCR and immunoblot analyses show that Cholestin extract significantly attenuates TNF-α-induced mRNA and protein expressions of MMP-2 and MMP-9. Gel shift assays show that Cholestin treatment reduces TNF-α-activated NF-κB. Furthermore, Cholestin also attenuates intracellular ROS generation in TNF-α-treated HASMCs. The supplement with an ROS scavenger N-acetyl-cysteine (glutathione precursor) gives similar results to Cholestin. CONCLUSIONS: Cholestin reduces TNF-α-stimulated MMP-2 and MMP-9 expression as well as downregulating NF-κB activation and intracellular ROS formation in HASMCs, supporting the notion that the natural compound Cholestin may have potential application in clinical atherosclerosis disease.

Green tea catechins inhibit the cultured smooth muscle cell invasion through the basement barrier.

Epidemiological studies suggest that green tea consumption is associated with a reduced risk of cardiovascular disease. Antioxidative properties of green tea flavonoids, catechins, have been believed to be involved in the antiatherogenic effect of green tea, since catechins inhibit low density lipoprotein oxidation. The migration of vascular smooth muscle cells (SMCs) from the tunica media to the subendothelial region is a key event in the development and progression of atherosclerosis and post-angioplasty vascular remodeling. Matrix metalloproteinases (MMPs) play a key role in these processes of SMC migration. In the present study, we investigated the effect of catechins on the gelatinolytic activity of MMP-2 that was derived from cultured bovine aortic SMCs. We also investigated the effect of catechins on the SMC invasion through the reconstituted basement membrane barrier. A major constituent of green tea catechins, (-)-epigallocatechin gallate (EGCG), inhibited the gelatinolytic activity of MMP-2 and concanavalin A (ConA)-induced pro-MMP-2 activation without the influence of membrane-type MMP expression in SMCs. EGCG also inhibited the SMC invasion through the basement membrane barrier in a concentration-dependent manner without any influence of SMC migration across the basement membrane protein thin-coated filter. The antagonistic effects of other catechins, namely (-)-epigallocatechin (EGC) and (-)-epicatechin gallate (ECG), on gelatinolytic activity of MMP-2, ConA-induced pro-MMP-2 activation, or PDGF-BB-directed SMC invasion were much less pronounced than those of EGCG. Also, (+)-catechin and (-)-epicatechin failed to show any effect. These findings may suggest that the anti-invasive and anti-metalloproteinase activities involve at least part of the anti-atherogenic action of catechin in accordance with the antioxidant properties of catechin.

Differences along the place-frequency map in the structure of supporting cells in the gerbil cochlea.

The function of supporting cells was investigated by comparing their morphologic adaptations at six different places in the gerbil cochlea. The volume of Deiters cells and tectal (cover) cells increased whereas that of Boettcher and Claudius cells decreased from base to apex. Deiters cells in the basal region tuned between 40 and 20 kHz lacked the unique rosette complex seen in regions encoding frequencies at or below 10 kHz. Deiters cells in high frequency regions differed from those at lower frequency places in several other ways: they possessed more apical microtubules, a larger basal microtubule stalk, mitochondria in the basal compartment, apical mitochondria that were unassociated with plasmalemma and more symmetric, and a less elaborately folded apicomedial plasmalemma enveloping fewer nerves. The tectal cells covering the outer tunnel appeared unlike Hensen cells in location and structure and differed further in exhibiting more variability with position in the cochlea. These covering cells in regions encoding high frequencies (20 and 40 kHz) extended a thin process medially that formed the roof of the outer tunnel and connected with the phalanx of the third Deiters cell. The tectal cells exclusively in places at 10 kHz or below projected numerous fimbriae into the outer tunnel. Hensen cells lateral to the cover cells also differed with frequency in showing abundant apical microvilli and mitochondria and basal juxtaposition to Boettcher cells only in the 40 to 20 kHz region. The observed structural differences provide evidence for functional variability along the place-frequency map. They attest to greater ion resorption from the outer tunnel by Deiters and tectal cells in low to mid frequency regions, and for greater ion exchange between endolymph and perilymph by Hensen, Boettcher and outer sulcus cells in regions of the cochlea encoding high frequencies. Amplification of the Deiters cells' microtubule system in the base of the cochlea possibly imparts increased stiffness to these cells and enhances transmission of mechanical energy at high frequency.

Growth of exocrine acinar cells on a reconstituted basement membrane gel.

Methods have been developed for culturing a dividing population of morphologically differentiated rat parotid, lacrimal, and pancreatic acinar cells in vitro. Isolated acinar cells were plated onto tissue culture dishes coated with a three-dimensional, reconstituted basement membrane gel. After attachment in Ham's nutrient mixture F12, the cells were cultured at 35 degrees C in F12 supplemented with 10% heat inactivated rat serum, epidermal growth factor, dexamethasone, insulin, transferrin, selenium, putrescine, reduced glutathione, ascorbate, penicillin, streptomycin, and the appropriate secretagogue. Under these conditions, the cells attached rapidly and DNA synthesis was initiated within 2 to 3 d. Although the cells flattened on the substratum, they continued to maintain their differentiated morphology. The cells contained secretory granules, and the secretory enzymes peroxidase and amylase could be detected. The use of a reconstituted basement membrane gel proved critical for the attachment and growth of exocrine acinar cells.

[Interrelationships of the neurosecretory cells and capillaries in the preoptic nucleus of the carp]. / O vzaimootnosheniiakh neirosekretornykh kletok s kapilliarami v preopticheskom iadre karpa.

Three layers are tentatively recognized in the wall of a blood capillary of nucleus praeopticus (NP) of the carp, Cyprinus carpio L: the inner layer--endothelium, the middle layer--basement membrane with pericytes, and the outer broken layer containing mostly leucocytes and fibroblast-like cells. 1). The plasmalemma of the neurosecretory cells (NSC) makes a direct contact with a capillary: (a) with the plasmalemma of a sole-like process of the endothelial cell (0.1%), (b) with the basement membrane of the capillary (4.9%), (c) with the plasmalemma of the outer layer cells (41.3%). 2) The plasmalemma of the NSC is separated from the capillary by a glial process (53.7%). The first kind of the contact is frequent in the ventral part (3.7%), and the second one--in the dorsal part (29.4%) of NP. The different relations of the NSC--the capillary of the ventral and dorsal parts are due to heterochronism of their development in ontogenesis.

[Morphological characteristics of the structures delimiting the residual cavity of the hypophysis in rats after electrocoagulation of the median eminence of the hypothalamus]. / Morfologicheskaia kharakteristika struktur, ogranichivaiushchikh ostatochnuiu polost' gipofiza krys, pri élektrokoaguliatsii sredinnogo vozvysheniia gipotalamusa

By means of light and electron microscopy it has been shown that the remnant cavity of the hypophysis of intact and sham-operated rats on the side of the intermedial lobe is restricted with a continuous layer of epithelial cells with a well pronounced basal membrane. On the side of the frontal lobe the covering epithelium has peculiar "fenestra" through which adenocytes have free contacts with the remnant cavity. After electrocoagulation of the rostral area of the medial eminence, especially in remote postoperative terms, the remnant cavity enlarges up to gigantic size, contains a great amount of colloid, erythrocytes, fragments of cells of the anterior lobe of the hypophysis and secretory granules. The anterior epithelium is lacking on considerable areas and hence adenocytes are disposed in the cavity directly. All their organoids are preserved though a little changed, the cytomembrane is absent. On the apical surface of the posterior epithelium there appear large cytoplasmic protrusions which having separated enter the remnant cavity. The main provider of the "raw material" for colloid is likely to be the anterior lobe of hypophysis.