Ameliorative Effects of Gallic Acid on Cisplatin-Induced Nephrotoxicity in Rat Variations of Biochemistry, Histopathology, and Gene Expression

BACKGROUND

Cisplatin is a powerful chemotherapeutic drug mainly used in the treatment of solid tumors. Aggregation of the drug in renal proximal tubule cells causes nephrotoxicity and renal failure. Investigations showed nephrotoxicity as Cisplatin's dose-limiting side effect. One of the Cisplatin toxicity mechanisms is generation of reactive oxygen species, which leads to oxidative stress and renal damage. The purpose of this study was evaluation of the modulating effects of Gallic acid on Cisplatin-induced variations including Caspase-3 and Clusterin expression and histopathological and biochemical parameters in adult male Wistar rats.

METHOD

Rats were kept under standard condition of temperature, light, and humidity. The animals were divided into 4 groups: GpI: control group (received distilled water for 10 days); GpII: Gallic acid (alone) (50 mg/kg bw, once a day for 10 days); GpIII: Cisplatin (alone), single dose (6 mg/kg bw, I.P. on 5th day of study); GpIV: Gallic acid (50 mg/kg bw, once a day for 10 days) and also injected with single dose of Cisplatin (6 mg/kg bw, I.P., on 5th day of study). After 10 days, all rats were anaesthetized and plasma collected to estimate urea, creatinine, and uric acid. The right kidneys were removed for the study of gene expression and biochemical parameters. The left kidneys were used for histopathological studies.

RESULTS

The Cisplatin-induced nephrotoxicity was evident from the elevated levels of creatinine, urea, uric acid, and renal tissue MDA and also decreased levels of SOD, CAT, GPX, and GSH in renal tissue. Administration of Gallic acid significantly modulated nephrotoxicity markers, gene expression variations, and histopathological damage.

CONCLUSION

Outcomes of the present investigation suggest that Gallic acid provides protection against CP-induced nephrotoxicity, but for application in people, further studies are needed.

Clusterin expression in nontumor tissue in patients with resectable hepatocellular carcinoma related with postresectional survival

BACKGROUND

Surgical resection offers an effective treatment for patients with hepatocellular carcinoma (HCC); however, it has high tumor recurrence rate. Clusterin is a highly conserved glycoprotein that enhances cell aggregation in vitro. It is upregulated in several types of cancers such as breast, ovarian, colon, prostate and kidney cancers, and HCC. Clusterin overexpression is correlated with tumor metastasis. We evaluated the significance of clusterin expression levels in serum and resected tissues of patients with HCC.

METHODS

Serum, resected tumor tissue, and nontumor tissue were collected from 140 patients with HCC undergoing hepatic resection. Serum clusterin levels were determined by enzyme-linked immunosorbent assay. Clusterin expression in resected tissue was evaluated by immunohistochemistry. Median follow-up time was 57.8 months.

RESULTS

Mean serum clusterin levels were found to be 130.0 ± 58.7 µg/mL (range, 10.1-366.6 µg/mL). Serum clusterin levels were independent of tumor stage and deterioration of liver function in patients. No significant difference was observed in the survival of patients with high (>130.0 ± 58.7 µg/mL) or low (≤130.0 ± 58.7 µg/mL) serum clusterin level. Clusterin was expressed in HCC tissues of 76 patients (54.3%) and nontumor liver tissues of 53 patients (37.9%). No significant difference was observed in the survival of patients with positive or negative clusterin expression in HCC tissues. In nontumor tissues, patients with positive clusterin expression were observed to have low postoperative disease-free survival rate (p = 0.001) compared to patients with negative clusterin expression. Multivariate analysis showed that tumor with macrovascular/microvascular invasion and clusterin expression in nontumor tissues are independent prognostic factors following hepatic resection.

CONCLUSION

In HCC, clusterin expression in nontumor tissue shows worse prognosis after hepatic resection. Clusterin can be a prognostic marker for patients with postresection HCC.

Colorimetric Paper-Based Immunosensor for Simultaneous Determination of Fetuin B and Clusterin toward Early Alzheimer's Diagnosis

Alzheimer's disease is a devastating condition characterized by a progressive and slow brain decay in elders. Here, we developed a paper-based lateral flow immunoassay for simultaneous and fast determination of Alzheimer's blood biomarkers, fetuin B and clusterin. Selective antibodies to targeted biomarkers were immobilized on gold nanoparticles (AuNPs) and deposited on paper pads. After adding the sample on the paper-based device, the biofluid laterally flows toward the selective antibody, permitting AuNP-Ab accumulation on the test zone, which causes a color change from white to pink. Image analysis was performed using a customized algorithm for the automatic recognition of the area of analysis and color clustering. Colorimetric detection was compared to electrochemical methods for the precise quantification of biomarkers. The best performance was found for the color parameter "L*". Good linearity (R² = 0.988 and 0.998) and reproducibility (%RSD = 2.79% and 1.82%, N = 3) were demonstrated for the quantification of fetuin B and clusterin, respectively. Furthermore, the specificity of the immunosensor was tested on mixtures of proteins, showing negligible cross-reactivity and good performance in complex environments. We believe that our biosensor has a potential for early-stage diagnosis of Alzheimer's disease and toward a better understanding of Alzheimer's developing mechanisms.

Development of a Label-Free Immunosensor for Clusterin Detection as an Alzheimer's Biomarker

Clusterin (CLU) has been associated with the clinical progression of Alzheimer's disease (AD) and described as a potential AD biomarker in blood plasma. Due to the enormous attention given to cerebrospinal fluid (CSF) biomarkers for the past couple of decades, recently found blood-based AD biomarkers like CLU have not yet been reported for biosensors. Herein, we report the electrochemical detection of CLU for the first time using a screen-printed carbon electrode (SPCE) modified with 1-pyrenebutyric acid N-hydroxysuccinimide ester (Pyr-NHS) and decorated with specific anti-CLU antibody fragments. This bifunctional linker molecule contains succinylimide ester to bind protein at one end while its pyrene moiety attaches to the carbon surface by means of π-π stacking. Cyclic voltammetric and square wave voltammetric studies showed the limit of detection down to 1 pg/mL and a linear concentration range of 1-100 pg/mL with good sensitivity. Detection of CLU in spiked human plasma was demonstrated with satisfactory recovery percentages to that of the calibration data. The proposed method facilitates the cost-effective and viable production of label-free point-of-care devices for the clinical diagnosis of AD.

Expression of clusterin in colorectal carcinoma in relation to clinicopathological criteria

BACKGROUND/AIM

Colorectal carcinoma (CRC) carries a high incidence of morbidity and mortality. Prognosis is related to nodal metastasis and stage. Clusterin is a widely distributed glycoprotein with not yet fully understood functions. Clusterin may be overexpressed in some tumours or under expressed in other tumours. The aim behind this study is to examine the relation of clusterin cytoplasmic immunostaining to tumour characteristics, disease relapse, and survival in CRC.

MATERIALS AND METHODS

Paraffin blocks of 133 CRCs were retrieved from the Department of Pathology, King Abdulaziz University, Jeddah, Saudi Arabia. Immunostaining was done using antibody to clusterin. Staining expression in 10% of malignant cells was used as a cut-off to determine low immunostaining and high immunostaining. Statistical tests were used to evaluate the association of clusterin immunostaining with clinicopathological parameters.

RESULTS

Immunohistochemical results showed clusterin low immunostaining in CRC and nodal metastases. No association was found between clusterin immunostaining and tumour grade, age, tumour invasiveness, distant metastases, vascular invasion, nodal metastases, relapse, and survival.

CONCLUSION

Our study showed low clusterin immunostaining in CRC with lack of association with prognostic indicators in CRC. These results raise the controversy of understanding the role of clusterin in CRC. Further molecular studies are required to explore more about possible mechanisms of clusterin association with tumorigenicity, apoptosis, tumour growth progression, local and vascular invasion, and metastasis of CRC.

Stromal Clusterin Expression Predicts Therapeutic Response to Neoadjuvant Chemotherapy in Triple Negative Breast Cancer

BACKGROUND

Expression of clusterin correlates with tumor progression and therapeutic response in several human malignancies, including breast cancer. However, its predictive value in the neoadjuvant setting in breast cancer remains unexplored. The objective of this explorative study was to determine whether clusterin expression in breast cancer correlated with clinical pathologic characteristics and whether its expression was predictive of response to neoadjuvant chemotherapy (NAC).

MATERIALS AND METHODS

We determined the clusterin expression pattern in 72 triple negative breast cancers (TNBC) treated with NAC before surgery. Clusterin expression was evaluated by immunohistochemistry and was correlated with pathologic characteristics and response to NAC using residual cancer burden score.

RESULTS

Immunohistochemistry analysis revealed a differential pattern of expression between tumor and stroma. Clusterin expression in the tumor associated stroma as opposed to expression by the neoplastic epithelium was significantly associated with neoadjuvant-treated TNBC. Low stromal clusterin, low stromal content, and high tumor-infiltrating lymphocytes were associated with a significantly greater likelihood of achieving a good pathologic response as reflected by lower residual cancer burden scores (P = .002, P = .003, and P = .001, respectively). Tumor and/or stromal clusterin expression were not associated with patient age, tumor histologic grade, stage, and lymph node status.

CONCULSION

This study suggests a potential role for the assessment of stromal clusterin as a predictive biomarker for response of TNBC to neoadjuvant therapy. Further validation of this biomarker in a large study is needed.

Spatiotemporal expression patterns of clusterin in the mouse inner ear

Clusterin (CLU) is an extracellular chaperone protein that is implicated in diverse physiological and pathophysiological cellular processes. CLU expression is upregulated in response to cellular stress and under certain conditions, such as neurodegenerative disease and cancer. CLU primarily functions as a chaperone that exerts cytoprotective effects by removing cellular debris and misfolded proteins and also acts as a signaling molecule that regulates pro-survival pathways. Deafness is caused by genetic factors and various extrinsic insults, including ototoxic drugs, exposure to loud sounds and aging. Considering its cytoprotectivity, CLU may also mediate cellular defense mechanisms against hearing loss due to cellular stresses. To understand the function of CLU in the inner ear, we analyze CLU expression patterns in the mouse inner ear during development and in the adult stage. Results of quantitative real-time polymerase chain reaction analysis showed that Clu mRNA levels in the inner ear were increased during embryogenesis and were constantly expressed in the adult. Detailed spatial expression patterns of Clu both in the mRNA and protein levels were analyzed throughout various developmental stages via in situ hybridization and immunofluorescence staining. Clu expression was found in specific domains of developing inner ear starting from the otocyst stage, mainly adjacent to the prosensory domain of the cochlear epithelium. In the mature inner ear, Clu expression was observed in Deiter's cells and pillar cells of the organ of Corti, outer sulcus and in basal cells of the stria vascularis in the cochlea. These specific spatiotemporal expression patterns suggest the possible roles of CLU in inner ear development and in maintaining proper hearing function.

The CLU-files: disentanglement of a mystery

The multifaceted protein clusterin (CLU) has been challenging researchers for more than 35 years. The characterization of CLU as a molecular chaperone was one of the major breakthroughs in CLU research. Today, secretory clusterin (sCLU), also known as apolipoprotein J (apoJ), is considered one of the most important extracellular chaperones ever found. It is involved in a broad range of physiological and pathophysiological functions, where it exerts a cytoprotective role. Descriptions of various forms of intracellular CLU have led to further and even contradictory functions. To untangle the current state of knowledge of CLU, this review will combine old views in the field, with new discoveries to highlight the nature and function of this fascinating protein(s). In this review, we further describe the expression and subcellular location of various CLU forms. Moreover, we discuss recent insights into the structure of CLU and assess how structural properties as well as the redox environment determine the chaperone activity of CLU. Eventually, the review connects the biochemistry and molecular cell biology of CLU with medical aspects, to formulate a hypothesis of a CLU function in health and disease.

Secretory clusterin (sCLU) overexpression is associated with resistance to preoperative neoadjuvant chemotherapy in primary breast cancer

OBJECTIVES

Preoperative chemotherapy is often used in patients with locally advanced breast cancer. However, commonly used clinical and pathological parameters are poor predictors of response to this type of therapy. The secreted form of the CLU protein (sCLU) is a glycosylated protein of 76-80 kDa. It has become increasingly clear that in most cells sCLU is a stress-associated cytoprotective protein that is upregulated by various apoptotic triggers. Furthermore, sCLU confers resistance by some unknown mechanism when overexpressed. The purpose of the present study was to examine the sCLU proteins as predictors of clinical outcome and response to chemotherapy in locally advanced breast cancer.

PATIENTS AND METHODS

The expression levels of sCLU was determined by immunohistochemistry before preoperative chemotherapy in 72 patients with locally advanced breast cancer. All patients were treated with cyclophosphamide/doxorubicin/5-FU(CAF) and some patients received additional treatment with docetaxel. Expression data were compared with patients' clinical and pathological features, clinical outcome, and response to chemotherapy.

RESULTS

The results showed sCLU expression before preoperative chemotherapy was inversely related to the tumor size, expression of estrogen and progesterone receptors. High preoperative expression of sCLU was associated with resistance to CAF therapy, but not with resistance to docetaxel.

CONCLUSIONS

We, therefore, suggested sCLU expression may be a useful marker for predicting response to preoperative chemotherapy and clinical outcome in patients with locally advanced breast cancer.

Factors affecting response of chemotherapy in women with ovarian cancer

Chemotherapy plays an important role in the treatment of ovarian cancer. Patients' response to chemotherapy is determined by a variety of acknowledged factors, but one might expect that many of them are yet to be described. The aim of this paper was to present the most essential yet still to be generally assessed in clinical practice, factors, which include: E-cadhedrin, hypoxia inducible factor alpha, survivin, COX-2, clusterin, BRCA1 protein, TP53 protein, YY1 protein, multidrug resistance protein, and interleukin-8.

Evaluation of sperm proteins in infertile men: a proteomic approach

In this study, the sperm protein profile was compared between fertile and infertile men using 2-dimensional gel electrophoresis, liquid chromatography mass spectrometer analysis, and matrix-assisted laser desorption ionization-time-of-flight-mass spectrometry. Four unique proteins, semenogelin II precursor, prolactin-induced protein, clusterin isoform 1, and prostate-specific antigen isoform 1 preproprotein, were predominantly present in the semen of healthy men; however, semenogelin II precursor and clusterin isoform 1 were not seen in the semen of infertile men, suggesting unique differences in the spermatozoa protein profiles of fertile and infertile men.

Clusterin isoforms differentially affect growth and motility of prostate cells: possible implications in prostate tumorigenesis

Besides a fully processed, secreted form of clusterin (sCLU), an alternative proapoptotic form of the protein targeting the nucleus (nCLU) was recently described. The possible differential roles played by the two clusterin forms in growth and motility of nonmalignant and malignant prostate cells are investigated here. sCLU or nCLU was transiently transfected in both androgen-independent prostate cancer cells (PC3 and DU 145) and immortalized prostate epithelial cells (PNT1A, a nontumoral control). Then, cell growth, motility, and cytoskeleton organization were studied. We found that (a) in PNT1A cells, both sCLU and nCLU significantly decreased cell proliferation and motility; (b) in PC3 and DU 145 cancer cells, only nCLU inhibited cell growth and migration, with sCLU being ineffective; and (c) the antimotility effect of nCLU was accompanied by a dramatic dismantling of the actin cytoskeleton. Moreover, transfection with "full-length" CLU cDNA produced both sCLU and nCLU in nonmalignant PNT1A cells, whereas only sCLU was found in cancer cells. Thus, CLU gene expression might play a crucial role in prostate tumorigenesis by exerting differential biological effects on normal versus tumor cells through differential processing of CLU isoforms in the two cell systems. We also found that nCLU binds to alpha-actinin, a key protein for the regulation of actin cytoskeleton, and that nCLU and alpha-actinin colocalize in the cytoplasm. Thus, the antimotility activity of nCLU and its ability to cause dismantling of the actin cytoskeleton seem to be mediated by its binding to alpha-actinin.

Prognostic significance of clusterin immunoreactivity in breast cancer

Clusterin (CLU) is involved in a variety of biological processes and has been found to be expressed even in many human malignancies, including breast cancer. Currently, there are only few data on the prognostic value of CLU in breast cancer. We therefore evaluated the relationship between CLU expression and clinicopathological parameters as well as relapse-free survival (RFS) and metastasis-free survival (MFS) of 141 breast cancer patients using the monoclonal antibody 7D1. CLU expression was found in 26% of cases and correlated significantly with high histological tumor grade and high Ki-67 labeling index (p=0.026 and p=0.010, respectively). Univariate Cox regression analysis revealed that CLU expression was tendentiously associated with RFS (p=0.068; relative risk [RR]: 1.77) and MFS (p=0.122; RR: 1.57). In a multivariate analysis, tumor grade, stage, estrogen receptor status and patients age (concerning RFS) as well as grade and lymph node status (concerning MFS) were identified as significant independent prognosticators. CLU expression showed an independent prognostic relevance concerning prediction of RFS by trend (p=0.110; RR: 1.81). We conclude from our data that estimation of CLU immunoreactivity may be helpful as a supplementary criterion to better assess the tumors propensity to relapse in selected cases of breast carcinoma.

Characterization and functional consequences of underexpression of clusterin in rheumatoid arthritis

We previously compared by microarray analysis gene expression in rheumatoid arthritis (RA) and osteoarthritis (OA) tissues. Among the set of genes identified as a molecular signature of RA, clusterin (clu) was one of the most differentially expressed. In the present study we sought to assess the expression and the role of CLU (mRNA and protein) in the affected joints and in cultured fibroblast-like synoviocytes (FLS) and to determine its functional role. Quantitative RT-PCR, Northern blot, in situ hybridization, immunohistochemistry, and Western blot were used to specify and quantify the expression of CLU in ex vivo synovial tissue. In synovial tissue, the protein was predominantly expressed by synoviocytes and it was detected in synovial fluids. Both full-length and spliced isoform CLU mRNA levels of expression were lower in RA tissues compared with OA and healthy synovium. In synovium and in cultured FLS, the overexpression of CLU concerned all protein isoforms in OA whereas in RA, the intracellular forms of the protein were barely detectable. Transgenic overexpression of CLU in RA FLS promoted apoptosis within 24 h. We observed that CLU knockdown with small interfering RNA promoted IL-6 and IL-8 production. CLU interacted with phosphorylated IkappaBalpha. Differential expression of CLU by OA and RA FLS appeared to be an intrinsic property of the cells. Expression of intracellular isoforms of CLU is differentially regulated between OA and RA. We propose that in RA joints, high levels of extracellular CLU and low expression of intracellular CLU may enhance NF-kappaB activation and survival of the synoviocytes.

Presence of plasma complement regulatory proteins clusterin (Apo J) and vitronectin (S40) on circulating immune complexes (CIC)

The complement regulatory (CR) proteins clusterin and vitronectin bind to the membrane attack complex (MAC) and thus prevent cytolysis. In this report, we demonstrate the presence of both of these CR proteins on MAC bound to circulating immune complexes (CIC). We measured the amount of clusterin and vitronectin on MAC in plasma, also referred to as soluble MAC (SMAC), as well as on MAC bound to CIC (MAC-CIC), using antibody directed to polymerized C9 in systemic lupus erythematosus (SLE) patients. We observed a strong correlation among the quantities of SMAC and MAC-CIC. The amount of both clusterin and vitronectin associated with MAC-CIC was two- to threefold higher in comparison to the SMAC. Patients with high levels of clusterin and vitronectin demonstrated renal involvement. We hypothesize that these complement regulatory proteins besides regulating the insertion of MAC play other critical roles, in disease pathogenesis.

Clusterin expression in follicular dendritic cells associated with prion protein accumulation

Peripheral accumulation of abnormal prion protein (PrP) in variant Creutzfeldt-Jakob disease and some animal models of transmissible spongiform encephalopathies (TSEs) may occur in the lymphoreticular system. Within the lymphoid tissues, abnormal PrP accumulation occurs on follicular dendritic cells (FDCs). Clusterin (apolipoprotein J) has been recognized as one of the molecules associated with PrP in TSEs, and clusterin expression is increased in the central nervous system where abnormal PrP deposition has occurred. We therefore examined peripheral clusterin expression in the context of PrP accumulation on FDCs in a range of human and experimental TSEs. PrP was detected immunohistochemically on tissue sections using a novel highly sensitive method involving detergent autoclaving pretreatment. A dendritic network pattern of clusterin immunoreactivity in lymphoid follicles was observed in association with the abnormal PrP on FDCs. The increased clusterin immunoreactivity appeared to correlate with the extent of PrP deposition, irrespective of the pathogen strains, host mouse strains or various immune modifications. The observed co-localization and correlative expression of these proteins suggested that clusterin might be directly associated with abnormal PrP. Indeed, clusterin immunoreactivity in association with PrP was retained after FDC depletion. Together these data suggest that clusterin may act as a chaperone-like molecule for PrP and play an important role in TSE pathogenesis.

Biomarkers in Diagnosis of pancreatic carcinoma in fine-needle aspirates

This study was undertaken to determine whether recently identified proteins could be translated to clinical practice as markers to distinguish pancreatic adenocarcinoma from chronic pancreatitis on fine-needle aspirate (FNA) samples. Resected pancreatic tissue sections (n = 40) and FNA samples (n = 65) were stained for clusterin-beta, MUC4, survivin, and mesothelin. For each biomarker, the staining patterns in adenocarcinoma and in reactive ductal epithelium were evaluated and compared. Clusterin-beta stained reactive ductal epithelium significantly more frequently than pancreatic adenocarcinoma (P < .001). In comparison, MUC4 and mesothelin were expressed more frequently in pancreatic adenocarcinoma on tissue sections. Positive staining for MUC4 (91% vs 0%; P < .001) and mesothelin (62% vs 0%; P = .01) and absence of staining for clusterin-beta (90% vs 7%; P < .001) were noted significantly more frequently in adenocarcinoma cells than in reactive cells in FNA samples. Clusterin-beta and MUC4 can help distinguish reactive ductal epithelial cells from the cells of pancreatic adenocarcinoma in FNA samples.

Expression of clusterin, XIAP and survivin, and their changes by camptothecin (CPT) treatment in CPT-resistant PC-3 and CPT-sensitive LNCaP cells

AIM

Clusterin and IAPs (inhibitor of apoptosis proteins), such as survivin and XIAP, are known to be related to chemo-resistance in several cancer cells. In the current study, we investigated their expression levels in human prostate cancer cell lines, LNCaP and PC-3 which are sensitive and resistant to camptothecin (CPT), topoisomerase I inhibitor, respectively.

METHODS

LNCaP and PC-3 cells were cultured in the presence of CPT, cell death was evaluated using Hoechst 33342 and propidium iodide (PI) double staining. The expression of clusterin, XIAP and survivin on mRNA and protein levels was investigated by semi-quantitative RT-PCR and Western blotting, respectively.

RESULTS

Our data showed that 24 h treatment of LNCaP cells with 0.5 and 3.0 microM CPT resulted in higher number of apoptotic cells, than that in PC-3 cells. Western blot analysis revealed that the clusterin level in PC-3 cells was 5-fold higher than that in LNCaP cells. In contrast, XIAP expression level in PC-3 cells was lower than that in LNCaP cells, and survivin levels were similar in these two cell lines. Treatment with 0.5 and 3.0 microM CPT resulted in the reduced survivin and XIAP expression in both cell lines, while clusterin expression remained unchanged in LNCaP cells, but was increased in PC-3 cells.

CONCLUSION

The results suggest that clusterin may take a greater part in CPT-resistance than survivin and XIAP in PC-3 cells.

Analysis of potential diagnostic biomarkers in cerebrospinal fluid of idiopathic normal pressure hydrocephalus by proteomics

BACKGROUND

The pathogenesis of idiopathic normal pressure hydrocephalus (INPH) is unknown, and the syndrome of INPH remains a diagnostic and therapeutic challenge. The present study investigated the disease-specific proteins that aid in the diagnosis and treatment of INPH and thus to study their role in the disease process.

METHODS

A comparative proteomic analysis was used for clinical screening of cerebrospinal fluid (CSF) proteins in 15 patients with INPH and compared with 12 normal subjects. Furthermore, enzyme linked immunosorbent assay (ELISA) was performed for comparison with CSF proteins between individual INPH patients and controls.

RESULTS

Seven proteins and their isoforms, including leucine-rich alpha-2-glycoprotein (LRG), alpha1-antichymotrypsin, apolipoprotein D, apolipoprotein J, haptoglobin alpha1, serum albumin, and alpha-1-microglobulin/bikunin precursor showed significant changes in CSF of INPH patients compared with controls by proteomic analysis. And significant higher CSF levels of LRG in INPH patients compared with controls were found by ELISA.

CONCLUSIONS

These results indicate that there are significant differences in the expression of certain proteins in the CSF of patients with INPH and normal subjects. In particular, the CSF level assay of LRG suggests that LRG is a specific biomarker for INPH and has potential use in the diagnosis and indication for CSF shunting.

Murine M cells express annexin V specifically

The specialized epithelium covering the lymphoid follicles of Peyer's patches in the gut mediates transcytosis of antigens to the underlying immune cells, mainly through the membranous, or M, cells. At present, the molecular processes involved in the mucosal immune response, and in antigen transport across the follicle-associated epithelium (FAE) and M cells, are poorly understood. To characterize FAE and M cells, we compared the gene expression profiles of small intestine FAE and villus epithelium (VE) in BALB/c mice by microarray analysis; 91 genes were found to be up-regulated and four down-regulated at least two-fold (p<0.01) in the FAE. The differential expression of a subset of these genes was shown to be confirmed by quantitative RT-PCR. Using immunohistochemistry on BALB/c Peyer's patches, cathepsin H and clusterin expression was increased in the FAE compared to the VE. Moreover, we demonstrated M cell-specific expression of annexin V, which has recently been reported to be important in endocytic transport and membrane scaffolding, suggesting that annexin V has a function in M cell-mediated transcytosis.

In situ AFM studies of astrocyte-secreted apolipoprotein E- and J-containing lipoproteins

The three-dimensional shapes and sizes of plasma lipoproteins and astrocyte-secreted lipoproteins (ASLPs) were characterized with the aid of in situ atomic force microscopy (AFM), which has the unique ability to study three-dimensional nanostructures under physiological conditions. Apolipoprotein E (apoE) and apolipoprotein J (apoJ) are the two most abundant apolipoproteins produced in the central nervous system (CNS). This study revealed that ASLPs containing apoE3, apoE4, or apoJ significantly differ from high density lipoprotein particles, thought to be their closest analogs in plasma, in aggregation properties, size, and shape. ASLPs were found to be significantly flatter and smaller than their plasma counterparts. Plasma lipoproteins were able to form ordered arrays on a mica surface at high concentration, but ASLPs did not. Rather, they formed amorphous aggregates at similar concentrations. Comprehensive quantitative characterization of particle size and shape was facilitated by two advances in AFM image analysis: (1) automated analysis through image-recognition algorithms, and (2) correction for the finite size of the AFM probe based on geometric modeling. This study and the developed AFM methodologies open the way to further in situ AFM studies of the lipoproteins in general and more specifically of CNS lipoproteins.