Journal of Histochemistry and Cytochemistry Priciples for Free Access to Science
  Search:   
    >> Advanced Search

Guidelines | Subscriptions | About | exPRESS - Current - Archive | Business Information | Contact

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Bribes, E.
Right arrow Articles by Simony–Lafontaine, J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Bribes, E.
Right arrow Articles by Simony–Lafontaine, J.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?
Journal of Histochemistry and Cytochemistry
Volume 52 (1): 19-28, 2004
Copyright ©The Histochemical Society, Inc.

Immunohistochemical Assessment of the Peripheral Benzodiazepine Receptor in Human Tissues

Estelle Bribes, Dominique Carrière, Catherine Goubet, Sylvaine Galiègue, Pierre Casellas and Joêlle Simony–Lafontaine

Department of Immunology–Oncology, Sanofi Synthelabo (EB,DC,CG,SG,PC), and Department of Pathology, Montpellier Cancer Institute (JSL), Montpellier, France

Correspondence to: P. Casellas, Sanofi-Synthelabo, 371 rue du Prof. Joseph Blayac, 34184 Montpellier Cedex 04, France. E-mail: pierre.casellas{at}sanofi-synthelabo.com


   Summary
Top
 Summary
Introduction
 Materials and Methods
 Results
 Discussion
 Literature Cited
 
Exhaustive analysis of the location of the peripheral benzodiazepine receptor (PBR) both at the subcellular and the tissue level is warranted to gain a better understanding of its biological roles. To date, many studies have been performed in animal models, such as rat, mouse, and pig, that yielded important information. However, only a few reports were dedicated to the analysis of PBR expression in humans. To enlarge on previous studies, we investigated PBR expression in different human organs using the monoclonal antibody 8D7 that specifically recognized the human PBR. First, we performed electron microscopic analysis that for the first time unambiguously demonstrated the localization of the PBR on the outer mitochondrial membrane. Second, focusing our analysis on human tissues for which information on PBR expression is sparse (lung, stomach, small intestine, colon, thyroid, adrenal gland, pancreas, breast, prostate, ovary), we found that PBR exhibits selective localization. This characterization of PBR localization in human tissues should provide important insights for the understanding of PBR functions.

(J Histochem Cytochem 52:19–28, 2004)

Key Words: peripheral benzodiazepine • receptor (PBR) • immunohistochemistry • mitochondria • human tissues


   Introduction
Top
 Summary
 Introduction
Materials and Methods
 Results
 Discussion
 Literature Cited
 
SINCE ITS IDENTIFICATION in 1977, the peripheral benzodiazepine receptor (PBR) has been the subject of intensive research to define its function. The protein was first described as a peripheral binding site for the benzodiazepine diazepam (Braestrup and Squires 1977Go) and has been reported to be involved in a variety of biological activities. These include control of steroidogenesis and apoptotic responses, regulation of cell proliferation, immunomodulation, porphyrin transport and heme synthesis, anion transport, and the modulation of mitochondrial respiration (for recent reviews see Casellas et al. 2002Go; Galiegue et al. 2003Go). Even though the functional understanding of PBR remains elusive, detailed information about its structure, pharmacological profile, and cell and tissue expression is now available. The 18-kD PBR is a highly hydrophobic protein primarily localized on the outer mitochondrial membrane, where it associates with the voltage-dependent anion channel (VDAC) and the nucleotide adenine carrier (ANC) to form the mitochondrial permeability transition pore (MPTP; McEnery et al. 1992Go). Some benzodiazepines (Ro5-4864), isoquinoline carboxamides (PK11195, PK14105), and the recently described SSR180575, a pyridazinoindole derivative, bind PBR with nanomolar affinities and were extensively used to analyze PBR properties (Le Fur et al. 1983Go; Bribes et al. 2002Go; Ferzaz et al. 2002Go). A wide variety of endogenous molecules have also been shown to have high affinity for the PBR. They include the diazepam binding inhibitor DBI, its derived fragments (Costa and Guidotti 1991Go), the porphyrins (Verma et al. 1987Go), and cholesterol (Li and Papadopoulos 1998Go). Regarding PBR subcellular expression, in addition to its mitochondrial localization PBR has been described in non-mitochondrial fractions in hepatocytes (O'Beirne et al. 1990Go), on plasma membranes in erythrocytes (Olson et al. 1988Go), and in and around the nuclei of cells from human breast tumor biopsies and breast tumor cell lines (Hardwick et al. 1999Go). Throughout the body, PBRs are found in almost all tissues tested and exhibit various expression levels. First considered to have a restricted peripheral expression, PBR is also expressed in the brain, where relatively low levels are localized in glial cells and in the olfactory bulb (Anholt et al. 1985Go). In the periphery, glandular and secretory tissues are particularly rich, while kidney, heart, lung, and liver expressed intermediary PBR levels (De Souza et al. 1985Go). In some organs (adrenal glands, kidney, thymus), the distribution of the protein is not homogeneous (Anholt et al. 1985Go; Benavides et al. 1989Go; Bribes et al. 2002Go). All these data were obtained in rodents and only a few studies have thus far been performed in humans. For example, changes in PBR expression were observed in the brain of patients with Huntington's disease (Messmer and Reynolds 1998Go) and Alzheimer's disease (Owen et al. 1983Go). In the immune system, PBR is expressed in all human peripheral blood leukocyte subsets (Canat et al. 1993aGo). In skin from healthy donors, PBR was upregulated in the superficial differentiated layers of the epidermis (Stoebner et al. 1999Go). The analysis of PBR expression was performed according to two strategies: using either ligands or antibodies specific for the PBR. The former was the most common and was based on light microcopic autoradiographic techniques and binding studies, whereas the latter was rare and was restricted to specific organs or lesions. Mapping the expression of a protein by using a ligand as a probe is an indirect method that may be impaired owing to the presence of endogenous ligands that would interfere with the binding. In that context, the use of specific antibodies targeting the protein of interest is an alternative nonradioactive approach that offers the opportunity to bypass this disadvantage. We have produced a monoclonal antibody (MAb), called 8D7, specific for the human PBR. To enlarge on previous studies that are rare in humans, we investigated PBR distribution in a series of various normal human tissues by immunohistochemistry (IHC) using MAb 8D7. We focused our analysis on tissues for which information on PBR expression is sparse, including tissues from the respiratory system (lung) tissues from the digestive apparatus (stomach, colon, small intestine, liver) and, finally, tissues from the endocrine system (thyroid, pancreas, breast, prostate, ovary). In addition, we performed electron microscopic analysis of the subcellular expression of PBR. We report original findings on PBR expression that probably constitute important indications for a better understanding of PBR function.


   Materials and Methods
Top
 Summary
 Introduction
 Materials and Methods
Results
 Discussion
 Literature Cited
 
Tissue Samples
Samples of various normal tissues were taken from surgical specimen from patients who underwent a surgical cure for cancer at the Montpellier cancer Institute. Normal tissue was removed from the surrounding tumor and was fixed in formalin–alcohol for 24 hr, paraffin-embedded, and subsequently processed with routine techniques and IHC analysis. Normal tissue samples included tissues from the respiratory system (lung, 10 samples), glandular epithelia (colon, 12 samples; small intestine, 8 samples; stomach, 10 samples; breast, 20 samples) and endocrine tissues (thyroid, 10 samples; liver, 10 samples; pancreas, 12 samples; ovary, four samples; prostate, four samples).

Characteristics of MAb 8D7
The anti-human PBR MAb 8D7 was obtained by hybridoma fusion after mouse immunization with the human PBR C-terminal peptide (YHGWHGGRRLPE) conjugated to bovine serum albumin (Dussossoy et al. 1996Go). In Western blotting experiments, using either crude cell extracts or purified PBR, MAb 8D7 revealed a single band of 18 kD, which corresponds to the expected molecular weight defined by the human PBR cDNA sequence (Dussossoy et al. 1996Go). Its labeling specificity was previously demonstrated using the peptide competition method that abolished the labeling, by the absence of labeling in Jurkat wild-type cells that are negative for the expression of PBR, and by the specific labeling observed in yeast cells transfected to express the human PBR. No labeling was observed in the corresponding mock-transfected yeast cells (Dussossoy et al. 1996Go). Reinforcing the specificity of the labeling, MAb 8D7 does not crossreact with rat or mouse PBR, even though those proteins are 80% homologous. Finally, neither DBI nor protoporphyrin, which are two endogenous ligands for PBR, antagonized the antibody binding (Dussossoy et al. 1996Go).

Electron Microscopy
Human monocytic U937 cells were fixed with 4% formaldehyde and permeabilized with 0.05% saponin. Then the anti-PBR antibody (1:250) was added for 1 hr in 0.05% saponin/1% BSA in NaCl/Pi buffer. Goat anti-mouse IgG (Amersham, Poole, UK; diluted 10-fold) conjugated with 5-nm colloidal gold beads was used for immunogold labeling. Cells were fixed in 2.5% glutaraldehyde for 15 min. Cells were postfixed with OsO4 for 45 min and successively dehydrated with ethanol, propylene oxide and epoxypropylene. Cells were embedded in Epon resin and samples were sectioned (70 nm) with an ultramicrotome (Edelmann 2002Go). Micrographs were recorded with an electron microscope (JEOL 1010).

Immunohistochemical Analysis
The expression of PBR was analyzed with an IHC procedure. The antibody used was a mouse monoclonal anti-human PBR (Dussossoy et al. 1996Go) at dilution 1:350. In pancreas, islet cells and sparse endocrine cells were identified by IHC for chromogranin. In these structures, ß-cells were identified by IHC for insulin [guinea pig polyclonal antibody (DAKO, Glostrup, Denmark; ready-to-use LSAB2 kit), {alpha}-cells by IHC for glucagons (rabbit polyclonal antibody, DAKO; ready-to-use LSAB2 kit), {delta}-cells by IHC for somatostatin (rabbit polyclonal antibody, DAKO; ready-to-use LSAB2 kit). Two-µm-thick parrafin-embedded sections of tissue samples were analyzed, mounted on DAKO silanized slides. All procedures were carried out at room temperature. IHC detection of the different markers was done using the streptavidin–biotin (LSAB) method (DAKO LSAB kit; Carpinteria, CA). The sections, which had been preincubated with 3% H2O2 solution for 10 min to block endogenous peroxidase, were incubated for 20 min with blocking agent and for 2 hr with the primary antibody. They were next rinsed and incubated with the secondary antibody for 10 min. They were next incubated with streptavidin conjugated to horseradish peroxidase. A positive reaction was visualized with 3-amino-9-ethylcarbazol. Before mounting, the sections were counterstained with Mayer's hematoxylin. For the negative control, the primary antibody was omitted and replaced by an irrelevant antibody (monoclonal mouse anti-human IgG; DAKO). In addition, the specificity of the labeling with PBR was systematically demonstrated by the absence of staining after preadsorbing anti-PBR antibody overnight at 4C with the immunizing peptide (data not shown). The immunoreactivity was then evaluated by two observers using a high-power lens (x400 or x250).

Semiquantitative Evaluation of 8D7 Staining
The labeling was evaluated using a semiquantitative method, taking into account the staining intensity and the number of stained cells in different random fields. A score of 0–9 was calculated as the product of the increase in staining intensity compared with the negative controls (0, no labeling; 1, faint staining; 2, moderate staining; 3, strong staining) and the frequency of stained cells (0, less than 10%; 1, 10–25%; 2, 25–50%; 3, more than 50%). Scores were then recorded as an index: index 0 (score 0) meant no PBR expression, index 1 (score 1–2) meant weak PBR expression, index 2 (score 3–4), meant moderate PBR expression, and index 3 (score 6–9) meant strong PBR expression. Highly positive isolated cells were evaluated separately and were not taken into account to measure the expression level of PBR in a tissue.


   Results
Top
 Summary
 Introduction
 Materials and Methods
 Results
Discussion
 Literature Cited
 
Electron Microscopic Analysis of Subcellular PBR Expression
We examined the cellular distribution of PBR at the molecular level using electron microscopy on human monocytic U937 cells. Figure 1 shows representative labeling obtained with the 8D7 anti-human PBR antibody on mitochondria. At x105,000 magnification, both the double membrane around the mitochondria and the intermembrane space can be distinguished. The gold particles are clearly restricted to the outer mitochondrial membrane. No labeling was observed on other organelles. Neither the cell plasma membrane nor the nucleus was labeled. These results not only evidence the expression of the PBR on mitochondria but also demonstrate unambiguously that the receptor is located on the mitochondrial outer membrane.



View larger version (117K):
[in this window]
[in a new window]
  		Figure 1

Electron microscopic analysis of localization of PBR on mitochondria in U937 cells. Ultrathin cell sections were labeled with the anti-PBR MAb 8D7, followed by goat anti-mouse IgG conjugated to 5-nm colloidal gold as described in Materials and Methods. Cm, cytoplasmic matrix; Mm, mitochondrial matrix. Arrows indicate colloidal gold particles.

 
IHC Distribution of PBR Immunoreactivity in Normal Human Tissues
Tissue from the Respiratory System (Figure 2)
In the lung, the ciliated bronchial cells showed heterogeneous staining. Most of these cells exhibited no or very weak granular staining, but some cells showed moderate staining, generally located at the apical pole of the cells (Figure 2A). In the distal lung parenchyma, strong immunostaining was observed in some flat cells lining the alveoli; those positive cells are pneumocytes (Figure 2B). Bronchial submucosal glands also exhibited strong cytoplasmic staining around the nucleus and the cytoplasmic membrane, as well as the duct cells. In addition, foamy alveolar macrophages were highly immunoreactive. No staining was seen in the bronchial cartilage.



View larger version (54K):
[in this window]
[in a new window]
  		Figure 2

Immunocytochemical staining of human lung with anti-human PBR MAb 8D7. (A) Ciliated bronchial (C) cells are moderately positive; positively stained macrophages (M) are seen in the alveoli and some pneumocytes (P) are moderately stained. Original magnification x400. (Inset) Negative control. Original magnification x100. (B) Pneumocytes exhibiting strong immunostaining are lining alveoli. Original magnification x250.

 
Tissues from the Digestive System (Figures 3 and 4)
For the colon surface epithelium, both absorptive and goblet cells were weakly positive; the staining was localized on the basal pole (Figure 3A). The columnar epithelium lining the colon crypts was rather faintly stained. In contrast, basal cells at the bottom of the crypts often exhibited strong staining (Figure 3B). As in the colon, the small intestine showed very heterogeneous staining but at the cellular level the staining was regularly distributed (Figure 3C). The positive staining predominated in the villi, at the apical pole of the cells. In the liver, most hepatocytes were weakly stained, whereas a few cells showed a relatively strong staining (Figure 3D). Those cells had no specific distribution according to the hepatic lobules. The sinusoidal lining cells, the Kupffer cells, were strongly positive (Figure 3E). Bile ducts were also strongly positive and portal tracts were negative (Figure 3D). In the stomach, the gastric surface epithelium as well as gastric fundic cells (Figures 4A and 4B) and pyloric mucosa (Figure 4C) were strongly stained. Chief cells were strongly stained; the majority of staining was in the basal portion of the mucosa. Parietal cells appeared to be less positive (Figure 4B). The bottom of the glands showed no staining (Figure 4A).



View larger version (139K):
[in this window]
[in a new window]
  		Figure 3

Immunocytochemical staining of human tissues from the digestive tract with the MAb 8D7 anti-human PBR. (A,B) Colon. (A) Immunostaining is localized on the basal pole of both absorptive and goblet cells; cells at the bottom of the crypts exhibit strong staining. Original magnification x250. (B) Absorptive (A) and goblet (G) cells at the bottom of a crypt. Chorion macrophages (M) are stained. Original magnification is x1000. (C) Small intestine, part of two normal villi. Strong staining at the apical pole of both absorptive and goblet cells. Some of the crypt epithelial cells exhibit moderate staining. Original magnification x250. (D,E) Liver. (D) Strongly positive bile duct cells in an otherwise weakly stained hepatic parenchyma. Portal tracts show no staining. Original magnification x250. (E) Terminal hepatic venule (V) surrounded by weakly stained hepatocytes (H) and highly positive Kupffer cells (K). Sinusoidal cells (S), barely seen are often strongly positive. Original magnification is x400. (Insets) Negative controls. Original magnification x100.

 


View larger version (88K):
[in this window]
[in a new window]
  		Figure 4

Immunocytochemical staining of human stomach with MAb 8D7. (A) Gastric fundal mucosa: surface epithelium is strongly positive. Original magnification x250. (B) Gastric fundal mucosa: parietal cells (P) are generally negative. Nests of chief cells (C) in the basal portion of the mucosa are strongly positive. Original magnification x400. (C) Pyloric mucosa exhibits the same staining as fundal mucosa. (Insets) Negative controls. Original magnification x100.

 
Tissues from the Endocrine System (Figures 5 and 6)
In the thyroid, follicular cells appeared to be weakly or not at all immunoreactive for PBR (Figure 5A). The positive cells were usually located in dystrophic epithelium. Most often, sparse cells, approximately less than 5% of total cell number, were weakly stained with MAb 8D7. Only one of nine samples showed 50% of follicular cells strongly positive for PBR. Colloid appeared to be moderately stained. In the adrenal gland, cells of the adrenal cortex exhibited strong immunostaining for PBR, with a rather homogeneous granular pattern of cytoplasmic and/or peripheral staining around the cytoplasmic membrane, and also in zona glomerula, zona fasciculata, and zona reticularis (Figure 5B). As expected, no staining was observed in the medulla (data not shown). In the pancreas (Figures 5C and 5D), acini, the main exocrine secretory component, showed negative to moderate granular cytoplasmic immunostaining, heterogeneously distributed in the cells of some structures only (Figures 5C). Ducts were rather homogeneously and moderately stained, with luminal staining increasing. Islets, the endocrine component of the pancreas, demonstrated distinct immunostaining patterns from one sample to another. In most pancreas samples, no immunostaining of the islets was observed or, rarely, there were very few sparse endocrine cells expressing PBR. Those samples were highly immunoreactive for insulin, glucagon, and somatostatin (data not shown). In one sample, rare cells or sparse clusters of cells exhibited very strong immunostaining. In this sample, stained granules of various sizes were often concentrated in the cytoplasm adjacent to the nucleus. Some cells appeared totally stained. In Figure 5D, the parenchyma shows strong staining. In the ovary (Figure 6A), which was of postmenopausal status with an atretic corpus albicans, sparse cells of the cortex demonstrated strong granular cytoplasmic staining. The remaining secretory cells in a degenerating corpus albicans were moderately stained. The columnar cells of the surface epithelium were strongly positive for 8D7 immunostaining. In the breast (Figure 6B), normal breast components (ductal and acinar epithelial cells) showed different labeling levels. More often they showed weak granular cytoplasmic immunostaining, with a typical mitochondrial localization, but in some cases the staining was rather strong. The staining was homogeneously distributed in the cells and also in the structures. In many ducts there was a basal or/and a luminal increase in staining. A very similar immunostaining pattern was observed in dystrophic structures. In the prostate (Figures 6C and 6D), ducts and acini of the central zone and the peripheral zone were faintly stained or negative, except for those exhibiting epithelial hyperplasia (regular or atypical). The immunohistochemical data are summarized in Table 1.



View larger version (118K):
[in this window]
[in a new window]
  		Figure 5

Immunocytochemical staining of human endocrine tissues with MAb 8D7. (A) Thyroid. Normal follicular epithelium is rather negative. Some dystrophic cells (D) show faint staining. Some colloidal cells (C) exhibit positive staining. Original magnification x250. (B) Adrenal gland. In the adrenal cortex there are strongly positive cells in zona glomerula (upper half of the microphotograph) and zona fasciculata (lower half). Original magnification x400. (C,D) Pancreas: negative or sparse heterogeneous staining of the acini (A), no or faint immunostaining of the islets (I). Ducts (D) exhibit a homogeneous moderate staining. (D) Rarely, islets may exhibit strongly stained clusters of cells. Original magnification x250. (Insets) Negative controls. Original magnification x100.

 


View larger version (121K):
[in this window]
[in a new window]
  		Figure 6

Immunocytochemical staining of human endocrine tissues with MAb 8D7. (A) Ovary (cortex). Strong staining of columnar cells of the surface epithelium (E) is observed. Original magnification x400. (B) Breast. Normal breast tissue exhibits a regular, homogeneous, rather moderate staining of both ductular and glandular structures, with a basal increase. (C,D) Prostate. (C) Very faint staining of most normal glandular cells was seen; however, some hyperplastic structures exhibit moderate to strong staining. Original magnifications x250. (D) Detail: hyperplastic glands (H, hyperplastic nest of the cells). Original magnification x400. (Insets) Negative controls. Original magnification x100.

 

View this table:
[in this window]
[in a new window]
  		Table 1

Summary: distribution of PBR immunoreactivitya

 

   Discussion
Top
 Summary
 Introduction
 Materials and Methods
 Results
 Discussion
Literature Cited
 
The distribution of PBR has been widely described in several animal models. The goal of the present study was to characterize further the distribution of PBR in humans, focusing particularly on tissues for which information on PBR expression was rare. To this aim, we used the 8D7 monoclonal anti-PBR antibody that specifically and exclusively recognizes the human PBR (Dussossoy et al. 1996Go). We first addressed the subcellular localization of PBR. The localization of the PBR in mitochondria has been clearly established for 20 years, as demonstrated using fractionation approaches or confocal microscopy analyses combined with specific markers for this organelle. In mitochondria, autoradiographic binding studies have suggested that PBR is co-localized with cytochrome oxidase and monoamine oxidase, both of which are known to be expressed on the mitochondrial outer membrane (Anholt et al. 1986Go). To supply additional probes, we studied PBR expression at the molecular level using electron microscopy. The use of MAb 8D7 in electron microscopic experiments provides direct evidence that the receptor is unambiguously associated with the mitochondrial outer membrane. No other subcellular expression is observed with this antibody. Such a discrepancy with the findings of other studies, which evidenced the expression of PBR in and around the nucleus in breast cancer cell lines and biopsy specimens, may be related to a difference in the C-terminal epitope of PBR (one point mutation in the MDA MB231 cells was reported; Hardwick et al. 1999Go) or to a difference in signal peptide, chaperones, or partner proteins involved in the regulation of PBR subcellular localization. This may be related to pathological conditions, and further studies are warranted to address this issue.

We then performed a broad analysis of PBR in several human tissues using MAb 8D7. We analyzed PBR expression in different respiratory, digestive, and endocrine tissues. In this study, we demonstrated that PBR is widely distributed in almost all normal tissues analyzed (Table 1). In those tissues, PBR expression was generally moderate and was rather homogeneously distributed, although some sparse cells or clusters of cells appeared to be intensely stained. Very often the staining in normal tissues was located at one side of the cells. This pattern of distribution of the immunostaining in differentiated cells of many glandular epithelia (especially those with brush borders and microvilli), as observed in the small intestine, colon, and stomach, appears to fit with the previously described implication of PBR in differentiation mechanisms. An upregulation of PBR expression in differentiated cells versus undifferentiated ones was previously reported in different cell lines (leukemic cells; Ishiguro et al. 1987Go; Canat et al. 1993bGo; Taketani et al. 1994Go), melanoma cells (Landau et al. 1998Go), and skin (Stoebner et al. 1999Go). Further supporting a role for PBR in the differentiation process, PBR ligands were shown to induce cell differentiation (Nakajima et al. 1995Go).

In addition, previous data have shown that PBR is highly expressed in tissues involved in steroid synthesis, and its level of expression in normal tissues is correlated with the amount of mitochondrial materials in the cell. Most likely, the sparse strongly stained cells found in otherwise weakly stained normal tissues represent cells involved in considerable synthesis, which implies large amounts of mitochondrial materials. These data are illustrated by the intense staining of some endocrine islets in weakly stained pancreatic tissue. We did not find any staining in the glandular luminal products except in the thyroid, where colloid often exhibited a moderate staining. Colloid is a storage form of thyroid hormones, which undergo continuous resorption and transport through cytoplasmic pseudopodia from follicular cells. Therefore, the staining of colloid, together with the rare positively stained follicular cells, may correlate with the transport mediating function of PBR, as already shown for cholesterol (Bernassau et al. 1993Go; Li and Papadopoulos 1998Go), porphyrins (Taketani et al. 1995Go), and anions (Basile et al. 1988Go; Kinnally et al. 1993Go).

Taken together, our data provide original findings on PBR expression in humans under normal conditions. These data, which may be further extended to pathological states, may be the basis for a better understanding of PBR function.


   Acknowledgments
 
We wish to thank Nadine Lequeux, Michèle Radal, and Sylvie Roques, who provided expert technical assistance.


   Footnotes
 
Received for publication May 19, 2003; accepted August 21, 2003


   Literature Cited
Top
 Summary
 Introduction
 Materials and Methods
 Results
 Discussion
 Literature Cited
 

Anholt RR, De Souza EB, Oster–Granite ML, Snyder SH (1985) Peripheral-type benzodiazepine receptors: autoradiographic localization in whole-body sections of neonatal rats. J Pharmacol Exp Ther 233:517–526[Abstract/Free Full Text]

Anholt RR, Pedersen PL, De Souza EB, Snyder SH (1986) The peripheral-type benzodiazepine receptor. Localization to the mitochondrial outer membrane. J Biol Chem 261:576–583

Basile AS, Lueddens HW, Skolnick P (1988) Regulation of renal peripheral benzodiazepine receptors by anion transport inhibitors. Life Sci 42:715–726[Medline]

Benavides J, Dubois A, Dennis T, Hamel E, Scatton B (1989) Omega 3 (peripheral type benzodiazepine binding) site distribution in the rat immune system: an autoradiographic study with the photoaffinity ligand [3H]PK 14105. J Pharmacol Exp Ther 249:333–339[Abstract/Free Full Text]

Bernassau JM, Reversat JL, Ferrara P, Caput D, LeFu G (1993) A 3D model of the peripheral benzodiazepine receptor and its implication in intra mitochondrial cholesterol transport. J Mol Graph 11:236–244[Medline]

Braestrup C, Squires RF (1977) Specific benzodiazepine receptors in rat brain characterized by high-affinity (3H)diazepam binding. Proc Natl Acad Sci USA 74:3805–3809[Abstract/Free Full Text]

Bribes E, Casellas P, Vidal H, Dussossoy D, Casellas D (2002) Peripheral benzodiazepine receptor mapping in rat kidney. Effects of angiotensin II-induced hypertension. J Am Soc Nephrol 13:1–9[Abstract/Free Full Text]

Canat X, Carayon P, Bouaboula M, Cahard D, Shire D, Roque C, Le Fur G, et al. (1993a) Distribution profile and properties of peripheral-type benzodiazepine receptors on human hemopoietic cells. Life Sci 52:107–118[Medline]

Canat X, Guillaumont A, Bouaboula M, Poinot–Chazel C, Derocq JM, Carayon P, LeFur G, et al. (1993b) Peripheral benzodiazepine receptor modulation with phagocyte differentiation. Biochem Pharmacol 46:551–554[Medline]

Casellas P, Galiegue S, Basile AS (2002) Peripheral benzodiazepine receptors and mitochondrial function. Neurochem Int 40:475–486[Medline]

Costa E, Guidotti A (1991) Diazepam binding inhibitor (DBI): a peptide with multiple biological actions. Life Sci 49:325–344[Medline]

De Souza EB, Anholt RR, Murphy KM, Snyder SH, Kuhar MJ (1985) Peripheral-type benzodiazepine receptors in endocrine organs: autoradiographic localization in rat pituitary, adrenal, and testis. Endocrinology 116:567–573[Abstract/Free Full Text]

Dussossoy D, Carayon P, Feraut D, Belugou S, Combes T, Canat X, Vidal H, et al. (1996) Development of a monoclonal antibody to immuno-cytochemical analysis of the cellular localization of the peripheral benzodiazepine receptor. Cytometry 24:39–48[Medline]

Edelmann L (2002) Freeze-dried and resin-embedded biological material is well suited for ultrastructure research. J Microsc 207:5–26[Medline]

Ferzaz B, Brault E, Bourliaud G, Robert JP, Poughon G, Claustre Y, Marguet F, et al. (2002) SSR180575 (7-chloro-N,N,5-trimethyl-4-oxo-3-phenyl-3,5-dihydro-4H-pyridazino[4,5-b]indole-1-acetamide), a peripheral benzodiazepine receptor ligand, promotes neuronal survival and repair. J Pharmacol Exp Ther 301:1067–1078[Abstract/Free Full Text]

Galiegue S, Tinel N, Casellas P (2003) The peripheral benzodiazepine receptor: a promising therapeutic drug target. Curr Med Chem 10:1563–1572[Medline]

Hardwick M, Fertikh D, Culty M, Li H, Vidic B, Papadopoulos V (1999) Peripheral-type benzodiazepine receptor (PBR) in human breast cancer: correlation of breast cancer cell aggressive phenotype with PBR expression, nuclear localization, and PBR-mediated cell proliferation and nuclear transport of cholesterol. Cancer Res 59:831–842[Abstract/Free Full Text]

Ishiguro K, Taft WC, DeLorenzo RJ, Sartorelli AC (1987) The role of benzodiazepine receptors in the induction of differentiation of HL-60 leukemia cells by benzodiazepines and purines. J Cell Physiol 131:226–234[Medline]

Kinnally KW, Zorov DB, Antonenko YN, Snyder SH, McEnery MW, Tedeschi H (1993) Mitochondrial benzodiazepine receptor linked to inner membrane ion channels by nanomolar actions of ligands. Proc Natl Acad Sci USA 90:1374–1378[Abstract/Free Full Text]

Landau M, Weizman A, Zoref–Shani E, Beery E, Wasseman L, Landau O, Gavish M, et al. (1998) Antiproliferative and differentiating effects of benzodiazepine receptor ligands on B16 melanoma cells. Biochem Pharmacol 56:1029–1034[Medline]

Le Fur G, Perrier ML, Vaucher N, Imbault F, Flamier A, Benavides J, Uzan A, et al. (1983) Peripheral benzodiazepine binding sites: effect of PK 11195, 1-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinolinecarboxamide. I. In vitro studies. Life Sci 32:1839–1847[Medline]

Li H, Papadopoulos V (1998) Peripheral-type benzodiazepine receptor function in cholesterol transport. Identification of a putative cholesterol recognition/interaction amino acid sequence and consensus pattern. Endocrinology 139:4991–4997[Abstract/Free Full Text]

McEnery MW, Snowman AM, Trifiletti RR, Snyder SH (1992) Isolation of the mitochondrial benzodiazepine receptor: association with the voltage-dependent anion channel and the adenine nucleotide carrier. Proc Natl Acad Sci USA 89:3170–3174[Abstract/Free Full Text]

Messmer K, Reynolds GP (1998) Increased peripheral benzodiazepine binding sites in the brain of patients with Huntington's disease. Neurosci Lett 241:53–56[Medline]

Nakajima O, Hashimoto Y, Iwasaki S (1995) Possible involvement of peripheral-type benzodiazepine receptors in erythroid differentiation of human leukemia cell line, K562. Biol Pharm Bull 18:903–906[Medline]

O'Beirne GB, Woods MJ, Williams DC (1990) Two subcellular locations for peripheral-type benzodiazepine acceptors in rat liver. Eur J Biochem 188:131–138[Medline]

Olson JM, Ciliax BJ, Mancini WR, Young AB (1988) Presence of peripheral-type benzodiazepine binding sites on human erythrocyte membranes. Eur J Pharmacol 152:47–53[Medline]

Owen F, Poulter M, Waddington JL, Mashal RD, Crow TJ (1983) [3H]R05–4864 and [3H]flunitrazepam binding in kainate-lesioned rat striatum and in temporal cortex of brains from patients with senile dementia of the Alzheimer type. Brain Res 278:373–375[Medline]

Stoebner PE, Carayon P, Penarier G, Frechin N, Barneon G, Casellas P, Cano JP, et al. (1999) The expression of peripheral benzodiazepine receptors in human skin: the relationship with epidermal cell differentiation. Br J Dermatol 140:1010–1016[Medline]

Taketani S, Kohno H, Furukawa T, Tokunaga R (1995) Involvement of peripheral-type benzodiazepine receptors in the intracellular transport of heme and porphyrins. J Biochem (Tokyo) 117:875–880[Abstract/Free Full Text]

Taketani S, Kohno H, Okuda M, Furukawa T, Tokunaga R (1994) Induction of peripheral-type benzodiazepine receptors during differentiation of mouse erythroleukemia cells. A possible involvement of these receptors in heme biosynthesis. J Biol Chem 269:7527–7531[Abstract/Free Full Text]

Verma A, Nye JS, Snyder SH (1987) Porphyrins are endogenous ligands for the mitochondrial (peripheral-type) benzodiazepine receptor. Proc Natl Acad Sci USA 84:2256–2260[Abstract/Free Full Text]


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?


This article has been cited by other articles:


Home page
 Clin. Cancer Res.Home page
K. Maaser, P. Grabowski, Y. Oezdem, A. Krahn, B. Heine, H. Stein, H. Buhr, M. Zeitz, and H. Scherubl
Up-Regulation of the Peripheral Benzodiazepine Receptor during Human Colorectal Carcinogenesis and Tumor Spread
Clin. Cancer Res., March 1, 2005; 11(5): 1751 - 1756.
[Abstract] [Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Bribes, E.
Right arrow Articles by Simony–Lafontaine, J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Bribes, E.
Right arrow Articles by Simony–Lafontaine, J.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?


Guidelines | Subscriptions | About | exPRESS - Current - Archive | Business Information | Contact