Pierre-André Diener

Barrier Capacity of Human Placenta for Nanosized Materials

Background Humans have been exposed to fine and ultrafine particles throughout their history. Since the Industrial Revolution, sources, doses, and types of nanoparticles have changed dramatically. In the last decade, the rapidly developing field of nanotechnology has led to an increase of engineered nanoparticles with novel physical and chemical properties. Regardless of whether this exposure is unintended or not, a careful assessment of possible adverse effects is needed. A large number of projects have been carried out to assess the consequences of combustion-derived or engineered nanoparticle exposure on human health. In recent years there has been a growing concern about the possible health influence of exposure to air pollutants during pregnancy, hence an implicit concern about potential risk for nanoparticle exposure in utero. Previous work has not addressed the question of whether nanoparticles may cross the placenta. Objective In this study we investigated whether particles can cross the placental barrier and affect the fetus. Methods We used the ex vivo human placental perfusion model to investigate whether nanoparticles can cross this barrier and whether this process is size dependent. Fluorescently labeled polystyrene beads with diameters of 50, 80, 240, and 500 nm were chosen as model particles. Results We showed that fluorescent polystyrene particles with diameter up to 240 nm were taken up by the placenta and were able to cross the placental barrier without affecting the viability of the placental explant. Conclusions The findings suggest that nanomaterials have the potential for transplacental transfer and underscore the need for further nanotoxicologic studies on this important organ system.

Immunoproteasomes Largely Replace Constitutive Proteasomes During an Antiviral and Antibacterial Immune Response in the Liver

The proteasome is critically involved in the production of MHC class I-restricted T cell epitopes. Proteasome activity and epitope production are altered by IFN-γ treatment, which leads to a gradual replacement of constitutive proteasomes by immunoproteasomes in vitro. However, a quantitative analysis of changes in the steady state subunit composition of proteasomes during an immune response against viruses or bacteria in vivo has not been reported. Here we show that the infection of mice with lymphocytic choriomeningitis virus or Listeria monocytogenes leads to an almost complete replacement of constitutive proteasomes by immunoproteasomes in the liver within 7 days. Proteasome replacements were markedly reduced in IFN-γ−/− mice, but were only slightly affected in IFN-αR−/− and perforin−/− mice. The proteasome regulator PA28α/β was up-regulated, whereas PA28γ was reduced in the liver of lymphocytic choriomeningitis virus-infected mice. Proteasome replacements in the liver strongly altered proteasome activity and were unexpected to this extent, since an in vivo half-life of 12 days had been previously assigned to constitutive proteasomes in the liver. Our results suggest that during the peak phase of viral and bacterial elimination the antiviral cytotoxic T lymphocyte response is directed mainly to immunoproteasome-dependent T cell epitopes, which would be a novel parameter for the design of vaccines.

High-throughput tissue microarray analysis of 11q13 gene amplification (CCND1, FGF3, FGF4, EMS1) in urinary bladder cancer

Gene amplification is a common mechanism for oncogene overexpression. High‐level amplifications at 11q13 have been repeatedly found in bladder cancer by comparative genomic hybridization (CGH) and other techniques. Putitative candidate oncogenes located in this region are CCND1 (PRAD1, bcl‐1), EMS1, FGF3 (Int‐2), and FGF4 (hst1, hstf1). To evaluate the involvement of these genes in bladder cancer, a tissue microarray (TMA) containing 2317 samples was screened by fluorescence in situ hybridization (FISH). The frequency of gains and amplifications of all genes increased significantly from stage pTa to pT1–4 and from low to high grade. In addition, amplification was associated with patient survival and progression of pT1 tumours. Among 123 tumours with amplifications, 68.3% showed amplification of all four genes; 19.5% amplification of CCND1, FGF4, and FGF3; and 0.8% co‐amplification of FGF4, FGF3, and EMS1. Amplification of CCND1 alone was found in 9% of the tumours, while EMS1 alone was amplified in 1.6% and FGF4 in 0.8%. Overall, the amplification frequency decreased with increasing genomic distance from CCND1, suggesting that, among the genes examined, CCND1 is the major target gene in the 11q13 amplicon in bladder cancer. Copyright

Expression of epithelial cell adhesion molecule (EpCam) in renal epithelial tumors.

EpCam is an epithelial adhesion molecule expressed in a broad range of carcinomas. Clinical trials with specific humanized anti-EpCam antibodies have shown promising results and have been inaugurated in renal cell carcinoma (RCC) therapy. To study the EpCam expression profile, primary renal cell neoplasms as well as corresponding metastases were evaluated by immunohistochemistry in tissue microarrays. EpCam expression in oncocytomas and chromophobe RCCs was determined on conventional large sections. Moderate or strong EpCam expression was found in eighteen percent of clear cell (n = 147), 75% of chromophobe (n = 12), and 55% of papillary RCCs (n = 20), but not in oncocytomas (n = 3). On large sections, 90% of chromophobe RCCs (n = 20) showed a strong and homogeneous positivity, whereas oncocytomas (n = 15) revealed EpCam positivity in single tumor cells or small clusters. Fourteen percent of RCC metastases (n = 97) showed EpCam expression. Patients with EpCam expressing clear cell RCC showed a trend toward a better prognosis in a Cox regression analysis including stage, grade, and necrosis. The data suggest EpCam as a potential therapeutic target in a subset of patients with RCC. In addition, expression patterns of EpCam could become a helpful tool in the discrimination of chromophobe RCC and oncocytoma.

CDX-2 immunostaining in primary and secondary ovarian carcinomas

Aims: To assess the value of homeobox protein CDX-2 expression in the distinction between primary ovarian carcinomas and carcinomas metastatic to the ovary. Methods: CDX-2 expression was assessed by immunohistochemistry in 120 serous, 68 endometrioid, 24 clear cell, and 16 mucinous carcinomas of the ovary. In addition, CDX-2 immunoreactivity was investigated in 20 metastases from adenocarcinomas to the ovary (15 of colorectal, two of gastric, one of appendiceal, one of pancreatic, and one of cervical origin) and their corresponding primary tumours. Results: Almost all of the primary ovarian carcinomas lacked immunoreactivity for CDX-2. In contrast, 14 of the 16 metastases to the ovary from intestinal primaries showed CDX-2 immunoexpression. Conclusion: CDX-2 is a useful marker for differentiating primary ovarian carcinoma from carcinomas metastatic to the ovary.

Chromosomal imbalances in small cell carcinomas of the urinary bladder.

Small cell carcinomas (SCCs) represent a rare histological subtype of urinary bladder cancer. Little is known abut the genetic alterations in these tumours. To identify chromosomal aberrations that are typically present in SCC of the urinary bladder, ten tumours were analysed by comparative genomic hybridization (CGH). CGH allows screening for all relative DNA copy number gains and losses present in a tumour. SCCs of the bladder were characterized by a high number of genomic alterations (mean: 11·3 per tumour). Deletions were most frequent at 10q (7 of 10 tumours deleted), 4q, 5q (5/10 each), and 13q (4/10). These regions may carry tumour suppressor genes with relevance for this particular tumour type. Gains of DNA sequences were most prevalent at 8q (5/10), 5p, 6p, and 20q (4/10 each). High level amplifications were found at 1p22–32, 3q26.3, 8q24, and 12q14–21. These loci may pinpoint the localization of oncogenes with relevance for small cell bladder cancer. The analysis of one tumour having areas of both SCC and transitional cell carcinoma strongly suggests that SCC can develop from TCC through the acquisition of additional genetic alterations. Copyright

Bidirectional Transfer Study of Polystyrene Nanoparticles across the Placental Barrier in an ex Vivo Human Placental Perfusion Model.

Background Nanoparticle exposure in utero might not be a major concern yet, but it could become more important with the increasing application of nanomaterials in consumer and medical products. Several epidemiologic and in vitro studies have shown that nanoparticles can have potential toxic effects. However, nanoparticles also offer the opportunity to develop new therapeutic strategies to treat specifically either the pregnant mother or the fetus. Previous studies mainly addressed whether nanoparticles are able to cross the placental barrier. However, the transport mechanisms underlying nanoparticle translocation across the placenta are still unknown. Objectives In this study we examined which transport mechanisms underlie the placental transfer of nanoparticles. Methods We used the ex vivo human placental perfusion model to analyze the bidirectional transfer of plain and carboxylate modified polystyrene particles in a size range between 50 and 300 nm. Results We observed that the transport of polystyrene particles in the fetal to maternal direction was significantly higher than for the maternal to fetal direction. Regardless of their ability to cross the placental barrier and the direction of perfusion, all polystyrene particles accumulated in the syncytiotrophoblast of the placental tissue. Conclusions Our results indicate that the syncytiotrophoblast is the key player in regulating nanoparticle transport across the human placenta. The main mechanism underlying this translocation is not based on passive diffusion, but is likely to involve an active, energy-dependent transport pathway. These findings will be important for reproductive toxicology as well as for pharmaceutical engineering of new drug carriers. Citation Grafmueller S, Manser P, Diener L, Diener PA, Maeder-Althaus X, Maurizi L, Jochum W, Krug HF, Buerki-Thurnherr T, von Mandach U, Wick P. 2015. Bidirectional transfer study of polystyrene nanoparticles across the placental barrier in an ex vivo human placental perfusion model. Environ Health Perspect 123:1280–1286; http://dx.doi.org/10.1289/ehp.1409271

Submucosal endocervicosis of the bladder: An ectopic, glandular structure of Müllerian origin

Endocervicosis of the bladder is a rare, benign variant of endometriosis. The lesions are characterized by ectopic, glandular structures of Müllerian origin with intracytoplasmic mucin production. During placement of a ureteral stent, a cystic tumor in the posterior bladder wall was discovered in a 47-year-old woman with nephroureterolithiasis. CT and MRI revealed a 5×1.6 cm2 mass in the posterior bladder wall protruding into the lumen of the bladder. Urine culture and cytological analyses showed no malignancy. Transurethral biopsy of the tumor confirmed the diagnosis of endocervicosis. Complete transurethral resection was rejected due to the absence of symptoms and the benign condition of the lesion.

Frequent expression of the breast differentiation antigen NY-BR-1 in mammary and extramammary Paget's disease

While mammary Pagets disease (MPD) is clearly linked to breast cancer, the histogenesis of extramammary Pagets disease (EMPD) is controversial. Recently NY‐BR‐1, a differentiation antigen expressed in the breast and in skin adnexal structures was identified. Its protein expression is restricted to normal and neoplastic breast epithelium and to adnexal tumors of the skin.

Transfer studies of polystyrene nanoparticles in the ex vivo human placenta perfusion model: key sources of artifacts

Abstract Nanotechnology is a rapidly expanding and highly promising new technology with many different fields of application. Consequently, the investigation of engineered nanoparticles in biological systems is steadily increasing. Questions about the safety of such engineered nanoparticles are very important and the most critical subject with regard to the penetration of biological barriers allowing particle distribution throughout the human body. Such translocation studies are technically challenging and many issues have to be considered to obtain meaningful and comparable results. Here we report on the transfer of polystyrene nanoparticles across the human placenta using an ex vivo human placenta perfusion model. We provide an overview of several challenges that can potentially occur in any translocation study in relation to particle size distribution, functionalization and stability of labels. In conclusion, a careful assessment of nanoparticle properties in a physiologically relevant milieu is as challenging and important as the actual study of nanoparticle–cell interactions itself.