Immunoenzymatic detection of the new proliferation associated protein p100 by means of a cellular ELISA: specific detection of cells in cell cycle phases S, G2 and M

Does Candida Albicans Play a Role in the Etiology of Endometriosis?

Purpose

There is increasing evidence that immunologic mechanisms play a role in the pathogenesis of endometriosis. A high incidence of infection with Candida albicans in women with endometriosis has been reported. There is evidence to suggest that C. albicans may contribute to the pathogenesis of endometriosis possibly by modulating cytokine production.

Methods

Endometrial tissue was obtained from eight women attending Aberdeen Royal Infirmary for laparoscopic sterilization or investigation of infertility (n=7 patients without endometriosis, n= 1 patient with endometriosis). Culture of endometrial cells with inactivated Candida/Candida product was performed. The endometrial tissue was processed using a number of different assays including Ki-67 cell proliferation assay, DELFIA Ki-67 assay, MTT cell viability assay, and BrdU incorporation proliferation assay.

Results

The results from seven women without endometriosis showed that Candida product significantly (P<0.01) reduced both cell viability and cell proliferation in the presence and absence of estradiol. The effects of Candida product on endometrial cells from the patient with endometriosis differed from the average effect on seven women without endometriosis: stimulation of cell viability in the presence of estradiol and suppression of cell proliferation only at the highest dose. In terms of the effects of inactivated Candida, there was a reduction in cell viability by up to 60% (unlike in the normal women), but an increase in cell proliferation of cells both in the presence and absence of estradiol.

Conclusions

Our preliminary observations suggest that C. albicans may stimulate cell proliferation of endometrial cells from women with endometriosis whilst it seems to have an opposite effect on cells from women with no endometriosis. Caution must be exercised in the interpretation of the latter data since only one woman with endometriosis was included, but the results suggest there may be differences in the way in which Candida product and inactivated Candida affect endometrial cell viability and proliferation between women with and without endometriosis.

Induction of renal endonuclease G by cisplatin is reduced in DNase I-deficient mice

Nephrotoxicity from the chemotherapeutic drug cisplatin is associated with DNA fragmentation and cell death. We have recently demonstrated that DNase I knockout mice are significantly protected against cisplatin nephrotoxicity, but it is unknown whether the DNA fragmentation that occurs is produced by DNase I or another endonuclease. In this study we assessed the expression of several endonucleases involved in cell death after injection of cisplatin and found that the expression of endonuclease G (EndoG) increased whereas the expression of DNase I decreased almost to zero. Immunostaining showed that some nuclei contained both fragmented DNA and EndoG, suggesting that EndoG may cause DNA fragmentation induced by cisplatin. The increase in expression of EndoG was greater in wild-type mice than in DNase I knockout mice, indicating a potential link between the two endonucleases. In support of such a link, overexpression of DNase I in cultured mouse tubular epithelial cells also induced EndoG. Furthermore, gene silencing of EndoG in vitro provided significant protection against cell death. Taken together, our data suggest that both DNase I and EndoG mediate cisplatin injury to tubular epithelial cells.

Carbamylated Low-Density Lipoprotein Induces Monocyte Adhesion to Endothelial Cells Through Intercellular Adhesion Molecule-1 and Vascular Cell Adhesion Molecule-1

Objective— Carbamylated low-density lipoprotein (LDL), the most abundant modified LDL isoform in human blood, has been recently implicated in causing the atherosclerosis-prone injuries to endothelial cells in vitro and atherosclerosis in humans. This study was aimed at testing the hypothesis that carbamylated LDL acts via inducing monocyte adhesion to endothelial cells and determining the adhesion molecules responsible for the recruitment of monocytes.

Methods and Results— Exposure of human coronary artery endothelial cells with carbamylated LDL but not native LDL caused U937 monocyte adhesion and the induction of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 adhesion molecules as measured by cell enzyme-linked immunosorbent assay. Silencing of intercellular adhesion molecule-1 by siRNA or its inhibition using neutralizing antibody resulted in decreased monocyte adhesion to the endothelial cells. Similar silencing or neutralizing of vascular cell adhesion molecule-1 alone did not have an effect but was shown to contribute to intercellular adhesion molecule-1 when tested simultaneously.

Conclusions— Taken together, these data provide evidence that intercellular adhesion molecule-1 in cooperation with vascular cell adhesion molecule-1 are essential for monocyte adhesion by carbamylated low-density lipoprotein-activated human vascular endothelial cells in vitro.

Endonuclease G promotes cell death of non-invasive human breast cancer cells

The invasiveness of breast cancer cells was shown to be associated with the suppressed ability to develop apoptosis. The role of cell death DNases/endonucleases has not been previously examined in relation with the invasiveness of breast cancer cells. We have compared the activity of the endonucleases in seven human breast cancer cell lines different in the level of invasiveness and differentiation. The invasiveness of cell lines was confirmed by an in vitro Matrigel-based assay. The total endonuclease activity in the differentiated non-invasive (WDNI) cell lines was higher than that in the poorly differentiated invasive (PDI) cells. The expression of EndoG strongly correlated with the degree of estrogen receptor expression and showed an inverse correlation with vimentin and matrix metalloproteinase-13. The EndoG-positive WDNI cells were more sensitive to etoposide- or camptothecin-induced cell death than EndoG-negative PDI cells. Silencing of EndoG caused inhibited of SK-BR-3 WDNI cell death induced by etoposide. Human ductal carcinomas in situ expressed high levels of EndoG, while invasive medullar and ductal carcinomas had significantly decreased expression of EndoG. This correlated with decreased apoptosis as measured by TUNEL assay. Our findings suggest that the presence of EndoG in non-invasive breast cancer cells determines their sensitivity to apoptosis, which may be taken into consideration for developing the chemotherapeutic strategy for cancer treatment.

Cisplatin Nephrotoxicity Is Mediated by Deoxyribonuclease I

Cisplatin is commonly used for chemotherapy in a wide variety of tumors; however, its use is limited by kidney toxicity. Although the exact mechanism of cisplatin-induced nephrotoxicity is not understood, several studies showed that it is associated with DNA fragmentation induced by an unknown endonuclease. It was demonstrated previously that deoxyribonuclease I (DNase I) is a highly active renal endonuclease, and its silencing by antisense is cytoprotective against the in vitro hypoxia injury of kidney tubular epithelial cells. This study used recently developed DNase1 knockout (KO) mice to determine the role of this endonuclease in cisplatin-induced nephrotoxicity. The data showed that DNase I represents approximately 80% of the total endonuclease activity in the kidney and cultured primary renal tubular epithelial cells. In vitro, primary renal tubular epithelial cells isolated from KO animals were resistant to cisplatin (8 microM) injury. DNase I KO mice were also markedly protected against the toxic injury induced by a single injection of cisplatin (20 mg/kg), by both functional (blood urea nitrogen and serum creatinine) and histologic criteria (tubular necrosis and in situ DNA fragmentation assessed by the terminal deoxynucleotidyl transferase nick end-labeling). These data provide direct evidence that DNase I is essential for kidney injury induced by cisplatin.

Biomimetic surface modification of poly (L-lactic acid) with gelatin and its effects on articular chondrocytes in vitro

Our objective in this study was to investigate the efficiency of two treatments for poly (L-lactic acid) (PLLA) surface modification with gelatin, via entrapment and coupling, using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and N-hydroxysuccinimide (NHS). The properties of original PLLA, gelatin-entrapped, and coupled PLLA films were investigated by water contact angle measurement and electron spectroscopy for chemical analysis (ESCA). The water contact angle indicated that the incorporation of gelatin resulted in a change in hydrophilicity, and the ESCA data suggested that the modified PLLA films became enriched with nitrogen atoms. The cytocompatibility of modified PLLA films might be improved. Therefore, we examined the attachment and proliferation of bovine articular chondrocyte seeded on modified PLLA films and virgin films. A whole-cell enzyme-linked immunosorbent assay (cell ELISA) that detects 5-bromo-2'-deoxyuridine (BrdU) incorporation during DNA synthesis and collagen type II secretion was applied to evaluate the chondrocytes on different PLLA films and tissue culture plates (TCPS). Cell viability was estimated by the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay, and cell function was assessed by measuring glycosaminoglycan (GAG) secreted by chondrocytes. These results implied that gelatin used to modify the PLLA surface through entrapment and coupling could enhance chondrocyte adhesion, proliferation, and function.

Biomimetic surface modification of poly(L-lactic acid) with chitosan and its effects on articular chondrocytes in vitro

The objective of this study was to investigate the efficiency of two treatments for poly(L-lactic acid) (PLLA) surface modification with chitosan, via entrapment and coupling by using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide. The properties of original PLLA films, chitosan-entrapped and coupled PLLA films were investigated by water contact angle measurement and electron spectroscopy for chemical analysis (ESCA). The contact angle indicated the change in hydrophilicity and the ESCA data suggested that the modified PLLA films became enriched with nitrogen atoms. The cytocompatibility of modified PLLA films might be improved. Therefore, the attachment and proliferation of bovine articular chondrocyte seeded on modified PLLA films and control one were examined. A whole cell enzyme-linked immunosorbent assay (Cell ELISA) that detects the BrdU incorporation during DNA synthesis and collagen type II secretion was applied to evaluate the chondrocytes on different PLLA films and tissue culture plates. Cell viability was estimated by the MTT assay and cell function were assessed by measuring sulfated glycosaminoglycan secreted by chondrocytes. These results implied that chitosan used to modify PLLA surface through entrapment and coupling could enhance the chondrocyte adhesion, proliferation and function.

Measurement of specific IgA in faecal extracts and intestinal lavage fluid for monitoring of mucosal immune responses

Currently available methods for the evaluation of antigen-specific immune responses in the intestine, i.e. measurement of IgA in intestinal lavage and antibody secreting cells (ASC) in peripheral blood, are not applicable to large-scale immunogenicity studies or to kinetic studies where repeated sampling is required. Simple and reliable methods need to be developed. Intestinal lavage and faecal samples were collected from 12 mice on days 0, 14, 21, 28 and 35 following initial immunization with four doses of cholera toxin (CT) by the gastric or rectal routes. The concentrations of anti-CT IgA in the faecal extracts showed a high level of correlation with those in the lavage samples (Spearman's correlation coefficient=0.85, P<0. 0001) regardless of the route of CT administration. Moreover, the kinetics of the immune response as reflected in the faecal extracts mirrored those in the lavage samples regardless of immunization route. As compared to gastric immunization, rectal administration of CT yielded higher levels of anti-CT IgA in both intestinal lavage fluids and in faecal extracts. The use of rectal immunization and the measurement of IgA in faecal extracts for monitoring mucosal immune responses may be relevant for the development of effective enteric vaccines.