CCL Cells Research Articles

Effect of PER1 on cell proliferation and cell migration

It has been widely studied and demonstrated that circadian rhythm, as well as circadian clock genes, plays an important role in many physiological and pathological processes. Period1 (Per1) gene is a core gene in the circadian clock system that is involved in cell differentiation and apoptosis. To verify the role of PER1 on the proliferation of normal cells, we chose NIH3T3 cells to have their PER1 up-regulated by transfecting a Per1 expression plasmid and determining their proliferation rates. Previous studies demonstrated that cell migration could be regulated by matrix metallopeptidase 2 (MMP2), and this MMP2 protein had a relation with the circadian system. To investigate the function of PER1 on tumor cell migration, Lewis lung carcinoma (LLC) cells were chosen to have their PER1 up-regulated, and the MMP2 level and the migration of LLC cells were tested. Our study showed that PER1 overexpression led to MMP2 down regulation in both NIH3T3 and CCL cells and inhibited the proliferation rate in NIH3T3. Migration of LLC cells could also be suppressed by the overexpression of PER1, probably by the down-regulation effect of PER1 on MMP2.

In vitro cytoprotective effects of acetylsalicylic acid, carprofen, meloxicam, or robenacoxib against apoptosis induced by sodium nitroprusside in canine cruciate ligament cells

To determine whether incubation of cruciate ligament cells with acetylsalicylic acid, carprofen, meloxicam, or robenacoxib provides protection against apoptosis induced by sodium nitroprusside (SNP). Explants of cranial (CCL) and caudal (CaCL) cruciate ligaments from eight 1-day-old Beagles. Primary cultures of CCL and CaCL cells were created via enzymatic dissociation of cruciate explants. Purified cell cultures were incubated for 2 hours without (controls) or with 1 of 3 concentrations of 1 of 4 NSAIDs (10, 100, or 200 μg of acetylsalicylic acid/mL; 0.1, 1, or 10 μg of carprofen/mL; 0.1, 1, or 10 μg of meloxicam/mL; or 0.1, 1, or 10 μg of robenacoxib/mL) and subsequently incubated for 18 hours with 1 of 3 concentrations of SNP in an attempt to induce mild, moderate, or severe cytotoxic effects. Cell viability and apoptosis were analyzed via a cell proliferation assay and flow cytometry, respectively. Prostaglandin E(2) concentrations were measured via an ELISA. Cytoprotective effects of NSAIDs were dependent on the extent of SNP-induced apoptosis and were greatest in CCL and CaCL cell cultures with moderate SNP-induced cytotoxic effects. Preincubation with an NSAID improved cell viability by 15% to 45% when CCL and CaCL cells were subsequently incubated with SNP. Carprofen (10 μg/mL) had the greatest cytoprotective effects for CCL and CaCL cells. Incubation with NSAIDs resulted in a nonsignificant decrease in PGE(2) production from SNP-damaged cells. Results indicated that carprofen, meloxicam, and robenacoxib may reduce apoptosis in cells originating from canine cruciate ligaments.

The Effect of Uniaxial Cyclic Tensile Load on Gene Expression in Canine Cranial Cruciate Ligamentocytes

To determine the effects of uniaxial cyclic tensile load amplitude and duration on gene expression in cranial cruciate ligamentocytes cultured in monolayer. In vitro experimental study. Adult dogs (n=9) weighing 20-35 kg. Cranial cruciate ligaments (CCL, n=18) were aseptically collected, diced, digested using clostridial collagenase, and primary monolayer cultures were established. CCL cells were seeded at a concentration of 3 x 10(5) cells/mL onto a specialized collagen membrane. After 24 hours to allow attachment, ligamentocytes were subjected to 0%, 4%, or 8% uniaxial strain for 24 or 48 hours using a sinusoidal strain profile at 0.5 Hz. At the end of each time point, the ligamentocytes were harvested and analyzed for collagen 1 (COL1), collagen 3 (COL3), and matrix metalloproteinase-3 (MMP-3) gene expression using reverse transcriptase real-time polymerase chain reaction. Approximately 33% of CCL processed for this study yielded viable cell cultures compared with 100% of the medial collateral ligaments processed. For CCL cells under uniaxial strain, gene expression for COL1 was variable, but higher strains and longer time in culture resulted in increased COL1 expression. There were no significant differences found for COL3 at any time point or between strain regimens. In general, MMP-3 gene expression was increased early in tissue culture and at higher strains. COL1 and MMP-3 gene expression can be influenced by amplitude and duration of strain on CCL cells in monolayer culture. These data have implications for modeling and understanding canine cruciate ligament pathophysiology. In particular, MMP-3 could serve as a potential preventative or therapeutic target in cruciate disease.

Histopathological variation of primary mucosa-associated lymphoid tissue lymphoma of the oral cavity

Primary mucosa-associated lymphoid tissue (MALT) type lymphoma arising in the oral cavity is rare. We examined histopathologic, immunohistological and genotypic findings of seven cases of intraoral MALT lymphoma using formalin-fixed paraffin-embedded tissues. Histologically, two variants have been delineated. (i) In four cases of minor salivary gland type, the lymphoid follicles were surrounded by centrocyte-like (CCL) cells with occasional follicular colonization. The CCL cells invaded the residual salivary gland duct resulting in a lymphoepithelial lesion. CCL cells frequently showed plasmacytic differentiation. (ii) In three cases of follicular growth type, the lesion was characterized by follicular growth pattern resulting from prominent follicular colonization. CCL cells showed minimal plasma cell differentiation. There was no residual epithelial component detected even by cytokeratin immunostaining. There were no Epstein-Barr virus-encoded small RNA-positive cells detected by in situ hybridization. API2-MALT1 fusion transcript does not appear to be associated with either histological variant of primary intraoral MALT lymphoma.

Primary marginal zone B-cell lymphoma of the lymph node resembling plasmacytoma arising from a plasma cell variant of Castleman's disease. A clinicopathological and immunohistochemical study of seven patients.

Nodal marginal zone B-cell lymphomas (NMZBL) occasionally represent prominent plasma cell differentiation. Recently, we presented a patient with NMZBL who exhibited histological features that resembled plasmacytoma arising from a localized plasma cell variant of Castleman's disease. To further clarify the clinicopathological, immunohistochemical, and genotypical findings, we studied seven such patients. Clinically, these patients were characterized by localized disease and an indolent clinical course with a slowly growing bulky mass in the affected lymph node. Only one patient exhibited paraproteinemia. Histologically, the lesions were characterized by numerous evenly distributed germinal centers in extensive sheets of plasma cells. Various numbers of centrocyte-like (CCL) cells arranged in a marginal zone distribution pattern occupied the peripheral region of the lymph node. The majority of the lymphoid follicles had atrophic or regressive germinal centers. A few lymphoid follicles were colonized by CCL cells. Immunohistochemistry showed that all of the lesions contained a monoclonal plasma cell population. In three tumors, a number of the CCL cells had a similar light chain restriction pattern to that observed in plasma cells. Two of the four patients evaluated exhibited clonal bands for the IgH gene by polymerase chain reaction assay. Moreover, the presence of surface IgM+, IgD- and CD27+ CCL- cells suggests that these tumors are derived from memory B-lymphocytes.

Effects of hypoxia on glial cell expression of angiogenesis‐regulating factors VEGF and TGF‐β

Perivascular glial cells are thought to be involved in physiologic vascularization and also in pathologic angiogenesis in the central nervous system. We have previously shown that astrocytes are a source of transforming growth factor-β (TGF-β) and another inhibiting factor, which block endothelial cell growth and induce their apoptosis. Astroglia are also known to express vascular endothelial growth factor (VEGF), which is up-regulated during hypoxia. Here we demonstrate the effects of hypoxia on the expression of both TGF-β and VEGF by retinal glial cells. Muller cells isolated from rat retina were incubated under hypoxia or normoxia and the resulting conditioned media (H-MCM and N-MCM) were assayed for their effects on growth of bovine retinal capillary endothelial (BRE) and the TGF-β-sensitive mink lung epithelial CCL cells. The expression and quantities of VEGF and TGF-β (active vs. latent form) were determined by immuno-adsorption, Western or Northern blotting, and ELISA. N-MCM stimulated BRE cell growth by twofold but inhibited CCL cells under similar assay conditions, whereas H-MCM had a weak stimulating effect on BRE and substantial inhibitory activity on CCL cells. Adsorption of MCM by specific antibodies as well as Western and Northern blot analysis indicated that stimulating and inhibitory activities of MCM are due to the presence of VEGF and TGF-β, respectively. ELISA revealed that the hypoxia condition converts latent TGF-β into its active form. In N-MCM, TGF-β is found predominantly in the latent form, but in hypoxia MCM it is mainly active. Furthermore, it was found that treatment of Muller cells with exogenous TGF-β under either hypoxia or normoxia increases VEGF expression in a time- and dose-dependent fashion. TGF-β activation may, therefore, be prerequisite for hypoxia-induced up-regulation of VEGF and stimulation of angiogenesis in vivo. GLIA 24:216–225, 1998. © 1998 Wiley-Liss, Inc.

Effects of hypoxia on glial cell expression of angiogenesis-regulating factors VEGF and TGF-?

Perivascular glial cells are thought to be involved in physiologic vascularization and also in pathologic angiogenesis in the central nervous system. We have previously shown that astrocytes are a source of transforming growth factor-beta (TGF-beta) and another inhibiting factor, which block endothelial cell growth and induce their apoptosis. Astroglia are also known to express vascular endothelial growth factor (VEGF), which is up-regulated during hypoxia. Here we demonstrate the effects of hypoxia on the expression of both TGF-beta and VEGF by retinal glial cells. Muller cells isolated from rat retina were incubated under hypoxia or normoxia and the resulting conditioned media (H-MCM and N-MCM) were assayed for their effects on growth of bovine retinal capillary endothelial (BRE) and the TGF-beta-sensitive mink lung epithelial CCL cells. The expression and quantities of VEGF and TGF-beta (active vs. latent form) were determined by immuno-adsorption, Western or Northern blotting, and ELISA. N-MCM stimulated BRE cell growth by twofold but inhibited CCL cells under similar assay conditions, whereas H-MCM had a weak stimulating effect on BRE and substantial inhibitory activity on CCL cells. Adsorption of MCM by specific antibodies as well as Western and Northern blot analysis indicated that stimulating and inhibitory activities of MCM are due to the presence of VEGF and TGF-beta, respectively. ELISA revealed that the hypoxia condition converts latent TGF-beta into its active form. In N-MCM, TGF-beta is found predominantly in the latent form, but in hypoxia MCM it is mainly active. Furthermore, it was found that treatment of Muller cells with exogenous TGF-beta under either hypoxia or normoxia increases VEGF expression in a time- and dose-dependent fashion. TGF-beta activation may, therefore, be prerequisite for hypoxia-induced up-regulation of VEGF and stimulation of angiogenesis in vivo.

Mucosa-Associated Lymphoid Tissue (MALT) Lymphoma of the Thymus

We present a rare case of primary low-grade B-cell lymphoma of the thymus. The tumor showed the typical features of a MALT (mucosa-associated lymphoid tissue) lymphoma with epithelium-lined thymic cyst. Histologically, there were sheets of centrocyte-like (CCL) cells intermingled with small lymphocytes and plasma cells. CCL cells invaded the epithelium of the cyst and residual Hassall's corpuscles, forming characteristic lymphoepithelial lesions. Immunohistochemically, the tumor cells revealed positive immunoreaction for CD20 and monotypic cytoplasmic restriction of kappa light chain.

B-cell lymphoma of MALT type: a review with special emphasis on diagnostic and management problems of low-grade gastric tumours.

B-cell lymphoma of MALT type: a review with special emphasis on diagnostic and management problems of low-grade gastric tumours.

Angiostatic role of astrocytes: suppression of vascular endothelial cell growth by TGF-beta and other inhibitory factor(s).

Our previous in vivo analyses have suggested that astrocytes play a key role in retinal vascularization by inducing endothelial cell differentiation. Here we demonstrate that medium conditioned by cultured rat brain astrocytes (ACM) contains factors, including transforming growth factor-beta (TGF-beta), that inhibit endothelial cell growth. Serum-free medium conditioned for 1-3 days was tested on exponentially growing bovine retinal microvascular endothelial, aortic endothelial, mink lung epithelial CCL-64, and Swiss mouse 3T3 fibroblast cells. The growth of all four cell types was inhibited in a dose- and time-dependent manner. CCL cells, which are used as a model for assaying TGF-beta activity, were more sensitive than the endothelial cells, suggesting that ACM contains TGF-beta. Moreover, acid treatment significantly increased the inhibitory activity of ACM, indicating that TGF-beta in ACM is predominantly in the latent form. Mouse fibroblasts, which are not affected by TGF-beta treatment under the same conditions, were also inhibited by ACM. This suggests that other inhibitory factors in addition to TGF-beta may be involved. Adsorption by an anti-TGF-beta polyclonal antibody column substantially reduced but did not eliminate the inhibitory activity of ACM for CCL and endothelial cells. Western blot analysis of ACM and proteins eluted from the affinity column revealed a 25 kDa band that co-migrates with TGF-beta. Comparative densitometry of the 25 kDa bands on Western blot indicated that the amount of TGF-beta in ACM is not sufficient to account for the total growth-inhibitory activity. These experiments demonstrate directly that rat brain astrocytes express TGF-beta. They also indicate that astrocytes may produce other growth-inhibitory factor(s) yet to be identified.

The lymphoepithelial lesion of gastric low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT): an ultrastructural study.

Lymphoepithelial lesions are a characteristic feature of primary, gastric low-grade lymphomas of mucosa-associated lymphoid tissue (MALT). The lymphoepithelial lesions in 12 such lymphomas have been examined by electronmicroscopy and immunohistochemistry. The lymphocytes present in these lesions are neoplastic centrocyte-like (CCL) B-cells and are morphologically and immunophenotypically similar to those of the surrounding lymphoma. Once the CCL cells penetrate the gastric glands, there is marked structural distortion and disruption of the epithelial cells which leads to their ultimate death. The close association of the neoplastic CCL cells and epithelial cells suggests the presence of a factor, an antigen or other receptor, on the plasma membrane of the latter through which these effects are mediated.

Follicular Colonization in B-Cell Lymphoma of Mucosa-Associated Lymphoid Tissue

The formation of neoplastic B-cell follicles is universally accepted as diagnostic of a follicle centre cell (FCC) lymphoma. Low-grade B-cell lymphomas of mucosa-associated lymphoid tissue (MALT) are characterized by a diffuse infiltrate of cells of uncertain lineage known as "centrocyte-like" cells because of their resemblance to centrocytes (small cleaved cells). Some MALT lymphomas, however, contain numerous follicles and may even have a predominantly follicular appearance. These follicles may be reactive or show immunoglobulin (Ig) light-chain restriction, indicating their neoplastic nature. We have proposed that these neoplastic follicles are not composed of follicle centre cells but result from colonization of reactive follicles by CCL cells. In this study, the immunophenotype and genotype of 10 primary gastrointestinal lymphomas with a follicular component have been determined. One case exhibited the morphological, immunophenotypic, and genotypic features of FCC lymphoma (Ig light-chain restriction, CD10+, KB61 (CDw32)-, Jh, and bcl-2 gene rearrangement). Neoplastic follicles in the remaining nine cases, which showed the features of MALT lymphoma, were of a different phenotype (Ig light-chain restriction, CD10- KB61(CDw32)+), and these lymphomas showed Jh but not bcl-2 gene rearrangement. Taken in conjunction with the morphological features, these findings suggest that in these cases the neoplastic follicles formed as the result of colonization of previously reactive follicles by neoplastic CCL cells. Thus, not all lymphomas containing neoplastic follicles are of FCC origin. Follicular colonization, as seen in low-grade MALT lymphomas, is likely to be a recapitulation of an as yet undescribed normal immunological phenomenon that may involve marginal zone B cells.

An Immunohistochemical Study

We performed a detailed histological and immunohistological study on both fresh-frozen and paraffin-embedded tissue from full-thickness jejunal biopsy specimens taken from three patients with immunoproliferative small-intestinal disease (IPSID). In all three patients, the mucosal infiltrate consisted of "centrocyte-like" (CCL) cells forming lymphoepithelial lesions and plasma cells. In one patient, the mucosal infiltrate was strikingly follicular. Immunohistochemistry showed alpha 1 heavy chain, but no light chain, in the perinuclear space and cytoplasm of the CCL cells and in the plasma cells. In two patients, the plasma cells (but not the CCL cells) also contained alpha 2 heavy chain. In the case showing a follicular pattern, the extrafollicular CCL cells and most of the cells within the mucosal follicles expressed alpha 1 heavy chain, but a minor and variable population of cells expressed polytypic IgM. The dendritic reticulum cells stained for alpha 1 (but not alpha 2) heavy chain, mu chain, and both light chains. In all cases, the CCL cells did not stain for common acute lymphoblastic leukaemia antigen (CALLA); in the follicles, CALLA negative cells displaced a residual CALLA-positive population to the periphery and merged with the CALLA negative cells outside the follicles. These findings confirm the homology between IPSID and low-grade B-cell "Western" lymphomas arising in mucosa-associated lymphoid tissue; they suggest that the follicular pattern sometimes seen in these lymphomas is caused by selective colonization of reactive follicles by CCL tumor cells.

Primary B-cell lymphoma of salivary glands and its relationship to myoepithelial sialadenitis

A detailed morphologic and immunohistochemical study has been carried out on salivary glands excised from 20 cases in which the initial histologic diagnosis was either myoepithelial sialadenitis (MESA) or salivary gland lymphoma (SGL). The results have shown that these cases, except one that had been diagnosed as MESA, showed a spectrum of changes ranging from focal lymphoid infiltrates, designated as early MESA, through established MESA with dense, extensive lymphoid infiltration, to lymphoma. The distribution of the lymphoid infiltrate in early MESA was related to ducts and mimicked Peyers patches. In established MESA, this infiltrate became confluent with the formation of prominent epimyoepithelial islands. The evolution of lymphoma was characterized by an expanded population of centrocyte-like (CCL) cells that showed light chain restriction. Like other lymphomas of mucosa-associated lymphoid tissue, to which they bear a striking resemblance, salivary gland lymphomas may remain localized for prolonged periods with a tendency to local recurrence rather than to distant spread. These properties may be explained by the histogenesis of these tumors from CCL cells that appear to be of similar lineage of splenic marginal zone cells.