Lactate Dehydrogenase-Elevating Virus Infection Inhibits MOG Peptide Presentation by CD11b+CD11c+ Dendritic Cells in a Mouse Model of Multiple Sclerosis.

Infections may affect the course of autoimmune inflammatory diseases of the central nervous system (CNS), such as multiple sclerosis (MS). Infections with lactate dehydrogenase-elevating virus (LDV) protected mice from developing experimental autoimmune encephalomyelitis (EAE), a mouse counterpart of MS. Uninfected C57BL/6 mice immunized with the myelin oligodendrocyte glycoprotein peptide (MOG35-55) experienced paralysis and lost weight at a greater rate than mice who had previously been infected with LDV. LDV infection decreased the presentation of the MOG peptide by CD11b+CD11c+ dendritic cells (DC) to pathogenic T lymphocytes. When comparing non-infected mice to infected mice, the histopathological examination of the CNS showed more areas of demyelination and CD45+ and CD3+, but not Iba1+ cell infiltration. These results suggest that the protective effect of LDV infection against EAE development is mediated by a suppression of myelin antigen presentation by a specific DC subset to autoreactive T lymphocytes. Such a mechanism might contribute to the general suppressive effect of infections on autoimmune diseases known as the hygiene hypothesis.

ECHDC1 knockout mice accumulate ethyl-branched lipids and excrete abnormal intermediates of branched-chain fatty acid metabolism.

The cytosolic enzyme ethylmalonyl-CoA decarboxylase (ECHDC1) decarboxylates ethyl- or methyl-malonyl-CoA, two side products of acetyl-CoA carboxylase. These CoA derivatives can be used to synthesize a subset of branched-chain fatty acids (FAs). We previously found that ECHDC1 limits the synthesis of these abnormal FAs in cell lines, but its effects in vivo are unknown. To further evaluate the effects of ECHDC1 deficiency, we generated knockout mice. These mice were viable, fertile, showed normal postnatal growth, and lacked obvious macroscopic and histologic changes. Surprisingly, tissues from wild-type mice already contained methyl-branched FAs due to methylmalonyl-CoA incorporation, but these FAs were only increased in the intraorbital glands of ECHDC1 knockout mice. In contrast, ECHDC1 knockout mice accumulated 16-20-carbon FAs carrying ethyl-branches in all tissues, which were undetectable in wild-type mice. Ethyl-branched FAs were incorporated into different lipids, including acylcarnitines, phosphatidylcholines, plasmanylcholines, and triglycerides. Interestingly, we found a variety of unusual glycine-conjugates in the urine of knockout mice, which included adducts of ethyl-branched compounds in different stages of oxidation. This suggests that the excretion of potentially toxic intermediates of branched-chain FA metabolism might prevent a more dramatic phenotype in these mice. Curiously, ECHDC1 knockout mice also accumulated 2,2-dimethylmalonyl-CoA. This indicates that the broad specificity of ECHDC1 might help eliminate a variety of potentially dangerous branched-chain dicarboxylyl-CoAs. We conclude that ECHDC1 prevents the formation of ethyl-branched FAs and that urinary excretion of glycine-conjugates allows mice to eliminate potentially deleterious intermediates of branched-chain FA metabolism.

Importance of pathological review of gestational trophoblastic diseases: results of the Belgian Gestational Trophoblastic Diseases Registry.

OBJECTIVE: To evaluate the added value of a centralized pathology review of the diagnoses of gestational trophoblastic diseases by expert pathologists and its potential impact on clinical management in a prospective multicenter study based on the Belgian Gestational Trophoblastic Diseases Registry. METHODS: From July 2012 to December 2020, the two referral centers of the registry were solicited to advise on 1119 cases. Referral pathologists systematically reviewed all of the initial histological diagnoses. Cases initially assessed by expert pathologists were excluded. A total of 867 files were eligible for the study. Concordance between diagnoses of gestational trophoblastic diseases made by general 'non-expert' and expert pathologists was analyzed together with the potential impact of the alterations on clinical management. Expert pathologists were working in an academic setting with high exposure to placental pathology and national recognition. RESULTS: The rate of discordance between expert and non-expert pathologists for the initial diagnoses was 35%. Almost 95% of complete moles were confirmed by the expert pathologists, but only 61% for partial moles. Compared with previous studies, ancillary techniques (p57 immunohistochemistry, karyotype) were used twice as often by both groups of pathologists in this survey. The diagnosis of gestational trophoblastic neoplasia was altered in 42% of cases. When the initial diagnosis was altered, the clinical relevance of this correction was estimated as down staging, up staging, or not relevant in 65%, 33% and 2% of cases respectively. CONCLUSION: Systematic centralized pathological review of gestational trophoblastic diseases modified the diagnosis in a third of cases. The results also show that a change in diagnosis would impact clinical management in 98% of patients.

New insights into the GDF9-Hedgehog-GLI signaling pathway in human ovaries: from fetus to postmenopause.

RESEARCH QUESTION: Are glioma-associated oncogene homolog 1, 2, and 3 (GLI1, 2, and 3) and protein patched homolog 1 (PTCH1) specific markers for precursor theca cells in human ovaries as in mouse ovaries? DESIGN: To study the GDF9-HH-GLI pathway and assess whether GLI1 and 3 and PTCH1 are specific markers for precursor theca cells in the human ovary, growth differentiation factor 9 (GDF9), Indian Hedgehog (IHH), Desert Hedgehog (DHH), Sonic Hedgehog (SHH), PTCH1 and GLI1, 2 and 3 were investigated in fetal (n=9), prepubertal (n=9), reproductive-age (n=15), and postmenopausal (n=8) human ovarian tissue. Immunohistochemistry against GDF9, IHH, DHH, SHH, PTCH1, GLI1, GLI2, and GLI3 was performed on human ovarian tissue sections fixed in 4% formaldehyde and embedded in paraffin. Western blotting was carried out on extracted proteins from the same samples used in the previous step to prove the antibodies' specificity. The quantitative real-time polymerase chain reaction was performed to identify mRNA levels for Gdf9, Ihh, Gli1, Gli2, and Gli3 in menopausal ovaries. RESULTS: Our results showed that, in contrast to mice, all studied proteins were expressed in primordial follicles of fetal, prepubertal, and reproductive-age human ovaries and stromal cells of reproductive-age and postmenopausal ovaries. Intriguingly, Gdf9, Ihh, and Gli3 mRNA, but not Gli1 and 2, was detected in postmenopausal ovaries. Moreover, GLI1, GLI3, and PTCH1 are not limited to a specific population of cells. They were spread throughout the organ, which means they are not specific markers for precursor theca cells in human ovaries. CONCLUSION: These results could provide a basis for understanding how this pathway modulates follicle development and ovarian cell steroidogenesis in human ovaries.

Ectopic Endometrium: The Pathologist's Perspective.

Endometriosis and adenomyosis are two frequent diseases closely linked, characterized by ectopic endometrium. Despite their benign nature, endometriosis and adenomyosis impair women's quality of life by causing pain and infertility and an increase in the incidence of gynecological malignancies has been reported. Since the first description of ectopic endometrium in 1860, different attempts have been made to describe, classify and understand the origin of these diseases. Several theories have been proposed to describe the pathogenic mechanism leading to the development of adenomyosis or endometriosis. However, all the hypotheses show some limitations in explaining all the different aspects and manifestations of these diseases. Despite the remarkable progress made over recent years, the pathogeneses of endometriosis and adenomyosis remain unclear. Moreover, because of the lack of standardized protocols and diagnostic criteria in pathology practice it is difficult to study and to classify these disorders. The goal of this review is to summarize the pathological aspects of adenomyosis and endometriosis, spanning a historical perspective to newly reported data.

Gene expression changes in uterine myomas in response to ulipristal acetate treatment.

RESEARCH QUESTION: Does ulipristal acetate (UPA) modify the expression of genes related to apoptosis or the extracellular matrix in uterine myomas and are any modifications associated with a clinical response? DESIGN: Targeted analysis of 176 apoptosis- or extracellular-matrix-related genes was conducted using polymerase chain reaction (PCR) arrays. Relevant results were validated by quantitative PCR. Four groups were established: responsive short-term (one course, n = 9), responsive long-term (two to four courses, n = 9), non-responsive (n = 9), and the control group who was not given any hormone therapy (n = 9). The clinical response was monitored by medical imagery and considered significant when volume reduction was greater than 25%. RESULTS: Compared with untreated myomas, significant changes in expression of four genes were found in UPA-treated myomas. Gene expression of integrin subunit beta 4 was repressed by UPA treatment (fold change [FC] = -12.50, P < 0.001, q < 0.001), tenascin-C expression was downregulated in UPA-responsive patients (FC = -2.50, P = 0.010, q = 0.090), survivin was repressed in short-term UPA-responsive tumours (FC = -7.69, P < 0.001, q = 0.010), and catenin delta 2 gene expression was upregulated in non-responsive myomas (FC = +7.36, P < 0.001, q = 0.010). CONCLUSION: This characterization provides the first molecular distinction between myomas responsive or non-responsive to UPA treatment.

Immune cell infiltration in head and neck squamous cell carcinoma and patient outcome: a retrospective study.

BACKGROUND: Human papillomavirus (HPV) prevalence in oropharynx squamous cell carcinoma (OPSCC) is on the rise. HPV-linked OPSCCs represent a distinct clinical entity with a better treatment response and patient survival compared to tumors not linked to HPV. An emerging role in treatment response has been attributed to immune cell infiltration in human tumors. In this study, we investigated immune cell infiltration in human SCC of the head and neck region and its relation to overall survival after treatment with surgery (with or without radiotherapy) or concomitant chemo (or cetuximab)-radiotherapy. MATERIALS AND METHODS: Paraffin-embedded tumor samples of 136 patients with SCC of the larynx, hypopharynx, oral cavity and oropharynx were processed for immunohistochemical detection of CD3+ T-cells, CD8+ cytotoxic T-cells, CD20+ B-cells and CD163+ M2 macrophages within the tumor infiltrated area. Clinico-pathological data were analyzed as a function of tumor location and p16-status. Immune cell infiltration was represented as stained area on the whole tumor infiltrated area, compared for the different tumor locations and correlated to patient survival. RESULTS: Patients with oropharynx tumors expressing significant p16 levels (p16-sg) had a 5-year overall survival of 85% compared to 43% for patients with no significant p16 (p16-ns) expression (HR: 0.3 - 95% CI: 0.1-0.6). Median immune cell infiltration (T- and B-lymphocytes) was significantly elevated in p16-sg oropharyngeal tumors, compared to p16-ns oropharyngeal tumors and to all other head and neck tumor locations. No difference in CD163+ macrophage infiltration was observed across the different patient groups. In the whole population, a high infiltration by CD3+ T-lymphocytes was associated to a significantly (p = .03; HR: 0.6, 95% CI: 0.4-0.97) better overall survival. CONCLUSION: Oropharynx cancer with significant p16 expression showed an increased overall survival and elevated T- and B-lymphocyte infiltration, which suggests a prognostic relevance of immune cell infiltration.

Respiratory hazard of Li-ion battery components: elective toxicity of lithium cobalt oxide (LiCoO2) particles in a mouse bioassay.

Rechargeable Li-ion batteries (LIB) are increasingly produced and used worldwide. LIB electrodes are made of micrometric and low solubility particles, consisting of toxicologically relevant elements. The health hazard of these materials is not known. Here, we investigated the respiratory hazard of three leading LIB components (LiFePO4 or LFP, Li4Ti5O12 or LTO, and LiCoO2 or LCO) and their mechanisms of action. Particles were characterized physico-chemically and elemental bioaccessibility was documented. Lung inflammation and fibrotic responses, as well as particle persistence and ion bioavailability, were assessed in mice after aspiration of LIB particles (0.5 or 2 mg); crystalline silica (2 mg) was used as reference. Acute inflammatory lung responses were recorded with the 3 LIB particles and silica, LCO being the most potent. Inflammation persisted 2 m after LFP, LCO and silica, in association with fibrosis in LCO and silica lungs. LIB particles persisted in the lungs after 2 m. Endogenous iron co-localized with cobalt in LCO lungs, indicating the formation of ferruginous bodies. Fe and Co ions were detected in the broncho-alveolar lavage fluids of LFP and LCO lungs, respectively. Hypoxia-inducible factor (HIF) -1α, a marker of fibrosis and of the biological activity of Co ions, was upregulated in LCO and silica lungs. This study identified, for the first time, the respiratory hazard of LIB particles. LCO was at least as potent as crystalline silica to induce lung inflammation and fibrosis. Iron and cobalt, but not lithium, ions appear to contribute to LFP and LCO toxicity, respectively.

Progesterone Receptor Isoforms, Nuclear Corepressor-1 and Steroid Receptor Coactivator-1 and B-Cell Lymphoma 2 and Akt and Akt Phosphorylation Status in Uterine Myomas after Ulipristal Acetate Treatment: A Systematic Immunohistochemical Evaluation.

OBJECTIVE: To investigate whether ulipristal acetate (UPA) treatment modifies the expression of progesterone receptor (PR), its nuclear cofactors steroid receptor coactivator-1 (SRC1) and nuclear corepressor-1 (NCoR1), prosurvival factor B-cell lymphoma 2 (Bcl-2), and Akt in uterine myomas. PATIENTS: Prospective study of 59 women with symptomatic myomas undergoing myomectomy. Forty-two patients were treated preoperatively with UPA; the remaining 17 were not and they served as controls. METHOD: Tissue microarrays were obtained from surgical specimens and immunohistochemistry was performed. Blinded quantification of expression of PR (PR-A vs. PR-B), coactivator SRC1 and corepressor NCoR1, and prosurvival factor Bcl-2, and Akt and evaluation of Akt phosphorylation levels. RESULTS: Compared with the control group, UPA does not alter PR protein levels or expression patterns in myomas, and the PR-A/PR-B ratio was similar, as well as cytoplasmic or nuclear expression of cofactors SRC1 and NCoR1. Bcl-2 was heterogeneously expressed throughout the samples and no significant modification in expression was evidenced. No significant difference was found in Akt expression and phosphorylation between treated and untreated myomas. CONCLUSION: This study did not find any significant change in the expression of the studied factors in myomas after UPA exposure. In conclusion, various theories on myomas cells proposed on the basis of in vitro studies are not supported in vivo.

A unique C-terminal domain allows retention of matrix metalloproteinase-27 in the endoplasmic reticulum.

Matrix metalloproteinase-27 (MMP-27) is poorly characterized. Sequence comparison suggests that a C-terminal extension (CTE) includes a potential transmembrane domain as in some membrane-type (MT)-MMPs. Having noticed that MMP-27 was barely secreted, we investigated its subcellular localization and addressed CTE contribution for MMP-27 retention. Intracellular MMP-27 was sensitive to endoglycosidase H. Subcellular fractionation and confocal microscopy evidenced retention of endogenous MMP-27 or recombinant rMMP-27 in the endoplasmic reticulum (ER) with locked exit across the intermediate compartment (ERGIC). Conversely, truncated rMMP-27 without CTE accessed downstream secretory compartments (ERGIC and Golgi) and was constitutively secreted. CTE addition to rMMP-10 (a secreted MMP) caused ER retention and blocked secretion. Addition of a PKA target sequence to the cytosolic C-terminus of transmembrane MT1-MMP/MMP-14 led to effective phosphorylation upon forskolin stimulation, but not for MMP-27, excluding transmembrane anchorage. Moreover, MMP-27 was protected from digestion by proteinase K. Finally, MT1-MMP/MMP-14 but neither endogenous nor recombinant MMP-27 partitioned in the detergent phase after Triton X-114 extraction, indicating that MMP-27 is not an integral membrane protein. In conclusion, MMP-27 is efficiently retained within the ER due to its unique CTE, which does not lead to stable membrane insertion. This could represent a novel ER retention system.

Digital pathology: elementary, rapid and reliable automated image analysis.

AIMS: Slide digitalization has brought pathology to a new era, including powerful image analysis possibilities. However, while being a powerful prognostic tool, immunostaining automated analysis on digital images is still not implemented worldwide in routine clinical practice. METHODS AND RESULTS: Digitalized biopsy sections from two independent cohorts of patients, immunostained for membrane or nuclear markers, were quantified with two automated methods. The first was based on stained cell counting through tissue segmentation, while the second relied upon stained area proportion within tissue sections. Different steps of image preparation, such as automated tissue detection, folds exclusion and scanning magnification, were also assessed and validated. Quantification of either stained cells or the stained area was found to be correlated highly for all tested markers. Both methods were also correlated with visual scoring performed by a pathologist. For an equivalent reliability, quantification of the stained area is, however, faster and easier to fine-tune and is therefore more compatible with time constraints for prognosis. CONCLUSIONS: This work provides an incentive for the implementation of automated immunostaining analysis with a stained area method in routine laboratory practice.

IL-1α induces CD11b(low) alveolar macrophage proliferation and maturation during granuloma formation.

Macrophages play a central role in immune and tissue responses of granulomatous lung diseases induced by pathogens and foreign bodies. Circulating monocytes are generally viewed as central precursors of these tissue effector macrophages. Here, we provide evidence that granulomas derive from alveolar macrophages serving as a local reservoir for the expansion of activated phagocytic macrophages. By exploring lung granulomatous responses to silica particles in IL-1-deficient mice, we found that the absence of IL-1α, but not IL-1ß, was associated with reduced CD11b(high) phagocytic macrophage accumulation and fewer granulomas. This defect was associated with impaired alveolar clearance and resulted in the development of pulmonary alveolar proteinosis (PAP). Reconstitution of IL-1α(-/-) mice with recombinant IL-1α restored lung clearance functions and the pulmonary accumulation of CD11b(high) phagocytic macrophages. Mechanistically, IL-1α induced the proliferation of CD11b(low) alveolar macrophages and differentiated these cells into CD11b(high) macrophages which perform critical phagocytic functions and organize granuloma. We newly discovered here that IL-1α triggers lung responses requiring macrophage proliferation and maturation from tissue-resident macrophages.

Dietary silver nanoparticles can disturb the gut microbiota in mice.

BACKGROUND: Humans are increasingly exposed via the diet to Ag nanoparticles (NP) used in the food industry. Because of their anti-bacterial activity, ingested Ag NP might disturb the gut microbiota that is essential for local and systemic homeostasis. We explored here the possible impact of dietary Ag NP on the gut microbiota in mice at doses relevant for currently estimated human intake. METHODS: Mice were orally exposed to food (pellets) supplemented with increasing doses of Ag NP (0, 46, 460 or 4600 ppb) during 28 d. Body weight, systemic inflammation and gut integrity were investigated to determine overall toxicity, and feces DNA collected from the gut were analyzed by Next Generation Sequencing (NGS) to assess the effect of Ag NP on the bacterial population. Ag NP were characterized alone and in the supplemented pellets by scanning transmission electron microscopy (STEM) and energy dispersive X-ray analysis (EDX). RESULTS: No overall toxicity was recorded in mice exposed to Ag NP. Ag NP disturbed bacterial evenness (α-diversity) and populations (ß-diversity) in a dose-dependent manner. Ag NP increased the ratio between Firmicutes (F) and Bacteroidetes (B) phyla. At the family level, Lachnospiraceae and the S24-7 family mainly accounted for the increase in Firmicutes and decrease in Bacteroidetes, respectively. Similar effects were not observed in mice identically exposed to the same batch of Ag NP-supplemented pellets aged during 4 or 8 months and the F/B ratio was less or not modified. Analysis of Ag NP-supplemented pellets showed that freshly prepared pellets released Ag ions faster than aged pellets. STEM-EDX analysis also showed that Ag sulfidation occurred in aged Ag NP-supplemented pellets. CONCLUSIONS: Our data indicate that oral exposure to human relevant doses of Ag NP can induce microbial alterations in the gut. The bacterial disturbances recorded after Ag NP are similar to those reported in metabolic and inflammatory diseases, such as obesity. It also highlights that Ag NP aging in food, and more specifically sulfidation, can reduce the effects of Ag NP on the microbiota by limiting the release of toxic Ag ions.

Mesothelioma response to carbon nanotubes is associated with an early and selective accumulation of immunosuppressive monocytic cells.

BACKGROUND: The asbestos-like toxicity of some engineered carbon nanotubes (CNT), notably their capacity to induce mesothelioma, is a serious cause of concern for public health. Here we show that carcinogenic CNT induce an early and sustained immunosuppressive response characterized by the accumulation of monocytic Myeloid Derived Suppressor Cells (M-MDSC) that counteract effective immune surveillance of tumor cells. METHODS: Wistar rats and C57BL/6 mice were intraperitoneally injected with carcinogenic multi-walled Mitsui-7 CNT (CNT-7) or crocidolite asbestos. Peritoneal mesothelioma development and immune cell accumulation were assessed until 12 months. Leukocyte sub-populations were identified by recording expression of CD11b/c and His48 by flow cytometry. The immunosuppressive activity on T lymphocytes of purified peritoneal leukocytes was assessed in a co-culture assay with activated spleen cells. RESULTS: We demonstrate that long and short mesotheliomagenic CNT-7 injected in the peritoneal cavity of rats induced, like asbestos, an early and selective accumulation of monocytic cells (CD11b/c(int) and His48(hi)) which possess the ability to suppress polyclonal activation of T lymphocytes and correspond to M-MDSC. Peritoneal M-MDSC persisted during the development of peritoneal mesothelioma in CNT-7-treated rats but were only transiently recruited after non-carcinogenic CNT (CNT-M, CNT-T) injection. Peritoneal M-MDSC did not accumulate in mice which are resistant to mesothelioma development. CONCLUSIONS: Our data provide new insights into the initial pathogenic events induced by CNT, adding a new component to the adverse outcome pathway leading to mesothelioma development. The specificity of the M-MDSC response after carcinogenic CNT exposure highlights the interest of this response for detecting the ability of new nanomaterials to cause cancer.

Critical role of aquaporins in interleukin 1ß (IL-1ß)-induced inflammation.

Rapid changes in cell volume characterize macrophage activation, but the role of water channels in inflammation remains unclear. We show here that, in vitro, aquaporin (AQP) blockade or deficiency results in reduced IL-1ß release by macrophages activated with a variety of NLRP3 activators. Inhibition of AQP specifically during the regulatory volume decrease process is sufficient to limit IL-1ß release by macrophages through the NLRP3 inflammasome axis. The immune-related activity of AQP was confirmed in vivo in a model of acute lung inflammation induced by crystals. AQP1 deficiency is associated with a marked reduction of both lung IL-1ß release and neutrophilic inflammation. We conclude that AQP-mediated water transport in macrophages constitutes a general danger signal required for NLRP3-related inflammation. Our findings reveal a new function of AQP in the inflammatory process and suggest a novel therapeutic target for anti-inflammatory therapy.

IL-27p28 is essential for parent-to-F1 acute graft-versus-host disease.

Acute graft versus host disease (aGVHD) remains a life-threatening complication of bone marrow transplantation. Here we show that IL-27, a member of the IL-12 cytokine family, plays an essential role in a parent-to-F1 murine aGVHD model, using B6 mice as parents and B6D2 mice as F1 recipients. IL-27 is transiently detectable in the serum of B6D2 recipients of B6 spleen cells, with a peak at day 10. Treatment with anti-IL-27p28 mAb MM27.7B1 (αp28Ab), at the time of and six days after B6 cell transfer, blocked GVHD. Protection was associated with host cell survival and undiminished engraftment of donor cells, lack of host B-cell depletion, increased Th2-type immunoglobulin production, a decrease in serum IFN-γ, a drop in anti-H-2D(d) cytotoxic T lymphocyte activity and an increase in Foxp3(+) T cells. We therefore conclude that IL-27 plays a critical role in the parent-to-F1 model of aGVHD and that blocking IL-27 could have therapeutic relevance.

Induction of post-menstrual regeneration by ovarian steroid withdrawal in the functionalis of xenografted human endometrium.

STUDY QUESTION: Does the endometrial functionalis have the potential to undergo self-renewal after menstruation and how is this process controlled by ovarian steroids? SUMMARY ANSWER: Endometrial xenografts subjected to withdrawal of estradiol and progesterone shrink but also show signs of proliferation and tissue repair; new estradiol supply prevents atrophy but is not sufficient to increase graft volume. WHAT IS KNOWN ALREADY: Menstruation, i.e. cyclic proteolysis of the extracellular matrix of endometrial functionalis, is induced by a fall in estrogen and progesterone concentration and is followed by tissue regeneration. However, there is debate about whether regenerating cells must originate from the basalis or from stem cells and whether new estrogen supply is required for the early repair concomitant with menstruation. STUDY DESIGN, SIZE, DURATION: Fragments from human endometrial functionalis (from 24 hysterectomy specimens) were xenografted in ovariectomized SCID mice and submitted to a 4-day estradiol and progesterone withdrawal (to mimic menstruation) followed by re-exposure to estradiol (to mimic the proliferative phase). We measured signs of proliferation and changes in graft volume. PARTICIPANTS/MATERIALS, SETTING, METHODS: Endometrium was collected from spontaneously cycling women. Cell proliferation was examined by immunolabeling Ki-67, cyclin D1 and phosphorylated-histone H3. Xenograft volume was measured by magnetic resonance imaging. Xenograft histomorphometry was performed to determine how the different tissue compartments contributed to volume change. MAIN RESULTS AND THE ROLE OF CHANCE: Hormone withdrawal induced a rapid decrease in graft volume mainly attributable to stroma condensation and breakdown, concomitant with an increase of proliferation markers. Reinsertion of estradiol pellets after induced menstruation blocked volume decrease and stimulated epithelial and stromal growth, but, surprisingly, did not induce graft enlargement. Reinsertion of both estradiol and progesterone pellets blocked apoptosis. LIMITATIONS, REASONS FOR CAUTION: Mechanisms of endometrial remodeling are different in women and mice and the contribution of circulating inflammatory cells in both species remains to be clarified. Moreover, during human menstruation, endometrial fragments resulting from tissue proteolysis can be expelled by the menstrual flow, unlike in this model. WIDER IMPLICATIONS OF THE FINDINGS: Menstruation is a multifocal event within the functionalis. This is the first evidence that endometrial fragments that are not shed after menstrual tissue breakdown can support endometrial regeneration. Endometriosis is commonly thought to result from the retrograde migration of menstrual fragments of the degraded functionalis into the peritoneal cavity. Our study supports their potential to regenerate as ectopic endometrium. STUDY FUNDING/COMPETING INTERESTS: This work was supported by the Fonds de la Recherche Scientifique Médicale, Concerted Research Actions, Communauté Française de Belgique, Région wallonne, Région bruxelloise and Loterie nationale. P.H. and B.F.J. are research associates of the Belgian Fonds de la Recherche Scientifique (F.R.S.-F.N.R.S.). E.M. is Associate Editor at Human Reproduction. There is no conflict of interest to declare.

Anomalies of the placenta and umbilical cord in twin gestations.

The frequency of twin gestations has increased over the last few decades, mainly due to maternal age at childbearing, and the use of assisted reproductive technologies. Twins are at higher risk of aneuploidy, structural anomalies, and placental abnormalities. Some of the placental and umbilical cord abnormalities found in twin gestations are nonspecific and can be found in singleton gestations (ie, placenta previa, placental abruption, single umbilical artery, velamentous cord insertion, vasa previa, etc). However, other anomalies are unique to twin gestations, and are mainly associated with monochorionic twins-these include intraplacental anastomosis and cord entanglement. Most of these conditions can be diagnosed with ultrasound. An accurate and early diagnosis is important in the management of twin gestations. Determination of chorionicity, amnionicity, and the identification of placental anomalies are key issues for the adequate management of twin pregnancies. Pathologic placental examination after delivery can help in assessing the presence of placental and umbilical cord abnormalities, as well as providing information about chorionicity and gaining insight into the potential mechanisms of disease affecting twin gestations.

Infrasellar pituitary gangliocytoma causing Cushing's syndrome.

INTRODUCTION: Pituitary gangliocytomas are uncommon neuronal tumours that may present with endocrine disorders, the most frequent being acromegaly caused by growth hormone hypersecretion. Cushing's syndrome is very rarely seen with gangliocytomas. MATERIAL AND METHODS: We report the unique case of a 62 year-old woman whose clinical picture and endocrine testing clearly demonstrated adrenocorticotropin (ACTH)-dependent Cushing's syndrome. Pituitary magnetic resonance imaging showed a 12-mm homogeneous, infra- and retrosellar mass first diagnosed as pituitary macroadenoma. Transsphenoidal surgery was performed and allowed complete resection of the tumour with sparing of normal anterior pituitary. Very low postoperative serum cortisol and ACTH levels were observed in the early postoperative period and the patient is still in remission 18 months after surgery, thus demonstrating that the resected lesion was entirely responsible for the clinical picture. RESULTS: Histological and immunocytochemical analyses demonstrated a benign tumour composed of mature neuronal cells suggestive of a gangliocytoma, expressing both ACTH and corticotropin-releasing hormone (CRH). The tumour was surrounded by a rim of pituitary tissue containing ACTH-producing endocrine cells. Careful analysis of the resected lesion did not reveal any pituitary microadenoma. We search literature for similar cases and retraced only nine cases of gangliocytomas associated with Cushing's syndrome. In most of them, the tumour was combined with either pituitary corticotroph adenoma or hyperplasia. CONCLUSIONS: Our case represents a unique case of an infrasellar pituitary gangliocytoma which was able to cause Cushing's syndrome by both direct ACTH production and CRH-induced stimulation of neighbour normal corticotroph cells.

Time course of pathogenic and adaptation mechanisms in cystinotic mouse kidneys.

Cystinosis, a main cause of Fanconi syndrome, is reproduced in congenic C57BL/6 cystinosin knockout (KO) mice. To identify the sequence of pathogenic and adaptation mechanisms of nephropathic cystinosis, we defined the onset of Fanconi syndrome in KO mice between 3 and 6 months of age and analyzed the correlation with structural and functional changes in proximal tubular cells (PTCs), with focus on endocytosis of ultrafiltrated disulfide-rich proteins as a key source of cystine. Despite considerable variation between mice at the same age, typical event sequences were delineated. At the cellular level, amorphous lysosomal inclusions preceded cystine crystals and eventual atrophy without crystals. At the nephron level, lesions started at the glomerulotubular junction and then extended distally. In situ hybridization and immunofluorescence revealed progressive loss of expression of megalin, cubilin, sodium-glucose cotransporter 2, and type IIa sodium-dependent phosphate cotransporter, suggesting apical dedifferentiation accounting for Fanconi syndrome before atrophy. Injection of labeled proteins revealed that defective endocytosis in S1 PTCs led to partial compensatory uptake by S3 PTCs, suggesting displacement of endocytic load and injury by disulfide-rich cargo. Increased PTC apoptosis allowed luminal shedding of cystine crystals and was partially compensated for by tubular proliferation. We conclude that lysosomal storage triggered by soluble cystine accumulation induces apical PTC dedifferentiation, which causes transfer of the harmful load of disulfide-rich proteins to more distal cells, possibly explaining longitudinal progression of swan-neck lesions. Furthermore, our results suggest that subsequent adaptation mechanisms include lysosomal clearance of free and crystalline cystine into urine and ongoing tissue repair.