Correction: The Minderoo-Monaco Commission on Plastics and Human Health

[This corrects the article DOI: 10.5334/aogh.4056.].

The Minderoo-Monaco Commission on Plastics and Human Health

Background

Plastics have conveyed great benefits to humanity and made possible some of the most significant advances of modern civilization in fields as diverse as medicine, electronics, aerospace, construction, food packaging, and sports. It is now clear, however, that plastics are also responsible for significant harms to human health, the economy, and the earth's environment. These harms occur at every stage of the plastic life cycle, from extraction of the coal, oil, and gas that are its main feedstocks through to ultimate disposal into the environment. The extent of these harms not been systematically assessed, their magnitude not fully quantified, and their economic costs not comprehensively counted.

Goals

The goals of this Minderoo-Monaco Commission on Plastics and Human Health are to comprehensively examine plastics' impacts across their life cycle on: (1) human health and well-being; (2) the global environment, especially the ocean; (3) the economy; and (4) vulnerable populations-the poor, minorities, and the world's children. On the basis of this examination, the Commission offers science-based recommendations designed to support development of a Global Plastics Treaty, protect human health, and save lives.

Report Structure

This Commission report contains seven Sections. Following an Introduction, Section 2 presents a narrative review of the processes involved in plastic production, use, and disposal and notes the hazards to human health and the environment associated with each of these stages. Section 3 describes plastics' impacts on the ocean and notes the potential for plastic in the ocean to enter the marine food web and result in human exposure. Section 4 details plastics' impacts on human health. Section 5 presents a first-order estimate of plastics' health-related economic costs. Section 6 examines the intersection between plastic, social inequity, and environmental injustice. Section 7 presents the Commission's findings and recommendations.

Plastics

Plastics are complex, highly heterogeneous, synthetic chemical materials. Over 98% of plastics are produced from fossil carbon- coal, oil and gas. Plastics are comprised of a carbon-based polymer backbone and thousands of additional chemicals that are incorporated into polymers to convey specific properties such as color, flexibility, stability, water repellence, flame retardation, and ultraviolet resistance. Many of these added chemicals are highly toxic. They include carcinogens, neurotoxicants and endocrine disruptors such as phthalates, bisphenols, per- and poly-fluoroalkyl substances (PFAS), brominated flame retardants, and organophosphate flame retardants. They are integral components of plastic and are responsible for many of plastics' harms to human health and the environment.Global plastic production has increased almost exponentially since World War II, and in this time more than 8,300 megatons (Mt) of plastic have been manufactured. Annual production volume has grown from under 2 Mt in 1950 to 460 Mt in 2019, a 230-fold increase, and is on track to triple by 2060. More than half of all plastic ever made has been produced since 2002. Single-use plastics account for 35-40% of current plastic production and represent the most rapidly growing segment of plastic manufacture.Explosive recent growth in plastics production reflects a deliberate pivot by the integrated multinational fossil-carbon corporations that produce coal, oil and gas and that also manufacture plastics. These corporations are reducing their production of fossil fuels and increasing plastics manufacture. The two principal factors responsible for this pivot are decreasing global demand for carbon-based fuels due to increases in 'green' energy, and massive expansion of oil and gas production due to fracking.Plastic manufacture is energy-intensive and contributes significantly to climate change. At present, plastic production is responsible for an estimated 3.7% of global greenhouse gas emissions, more than the contribution of Brazil. This fraction is projected to increase to 4.5% by 2060 if current trends continue unchecked.

Plastic Life Cycle

The plastic life cycle has three phases: production, use, and disposal. In production, carbon feedstocks-coal, gas, and oil-are transformed through energy-intensive, catalytic processes into a vast array of products. Plastic use occurs in every aspect of modern life and results in widespread human exposure to the chemicals contained in plastic. Single-use plastics constitute the largest portion of current use, followed by synthetic fibers and construction.Plastic disposal is highly inefficient, with recovery and recycling rates below 10% globally. The result is that an estimated 22 Mt of plastic waste enters the environment each year, much of it single-use plastic and are added to the more than 6 gigatons of plastic waste that have accumulated since 1950. Strategies for disposal of plastic waste include controlled and uncontrolled landfilling, open burning, thermal conversion, and export. Vast quantities of plastic waste are exported each year from high-income to low-income countries, where it accumulates in landfills, pollutes air and water, degrades vital ecosystems, befouls beaches and estuaries, and harms human health-environmental injustice on a global scale. Plastic-laden e-waste is particularly problematic.

Environmental Findings

Plastics and plastic-associated chemicals are responsible for widespread pollution. They contaminate aquatic (marine and freshwater), terrestrial, and atmospheric environments globally. The ocean is the ultimate destination for much plastic, and plastics are found throughout the ocean, including coastal regions, the sea surface, the deep sea, and polar sea ice. Many plastics appear to resist breakdown in the ocean and could persist in the global environment for decades. Macro- and micro-plastic particles have been identified in hundreds of marine species in all major taxa, including species consumed by humans. Trophic transfer of microplastic particles and the chemicals within them has been demonstrated. Although microplastic particles themselves (>10 µm) appear not to undergo biomagnification, hydrophobic plastic-associated chemicals bioaccumulate in marine animals and biomagnify in marine food webs. The amounts and fates of smaller microplastic and nanoplastic particles (MNPs <10 µm) in aquatic environments are poorly understood, but the potential for harm is worrying given their mobility in biological systems. Adverse environmental impacts of plastic pollution occur at multiple levels from molecular and biochemical to population and ecosystem. MNP contamination of seafood results in direct, though not well quantified, human exposure to plastics and plastic-associated chemicals. Marine plastic pollution endangers the ocean ecosystems upon which all humanity depends for food, oxygen, livelihood, and well-being.

Human Health Findings

Coal miners, oil workers and gas field workers who extract fossil carbon feedstocks for plastic production suffer increased mortality from traumatic injury, coal workers' pneumoconiosis, silicosis, cardiovascular disease, chronic obstructive pulmonary disease, and lung cancer. Plastic production workers are at increased risk of leukemia, lymphoma, hepatic angiosarcoma, brain cancer, breast cancer, mesothelioma, neurotoxic injury, and decreased fertility. Workers producing plastic textiles die of bladder cancer, lung cancer, mesothelioma, and interstitial lung disease at increased rates. Plastic recycling workers have increased rates of cardiovascular disease, toxic metal poisoning, neuropathy, and lung cancer. Residents of "fenceline" communities adjacent to plastic production and waste disposal sites experience increased risks of premature birth, low birth weight, asthma, childhood leukemia, cardiovascular disease, chronic obstructive pulmonary disease, and lung cancer.During use and also in disposal, plastics release toxic chemicals including additives and residual monomers into the environment and into people. National biomonitoring surveys in the USA document population-wide exposures to these chemicals. Plastic additives disrupt endocrine function and increase risk for premature births, neurodevelopmental disorders, male reproductive birth defects, infertility, obesity, cardiovascular disease, renal disease, and cancers. Chemical-laden MNPs formed through the environmental degradation of plastic waste can enter living organisms, including humans. Emerging, albeit still incomplete evidence indicates that MNPs may cause toxicity due to their physical and toxicological effects as well as by acting as vectors that transport toxic chemicals and bacterial pathogens into tissues and cells.Infants in the womb and young children are two populations at particularly high risk of plastic-related health effects. Because of the exquisite sensitivity of early development to hazardous chemicals and children's unique patterns of exposure, plastic-associated exposures are linked to increased risks of prematurity, stillbirth, low birth weight, birth defects of the reproductive organs, neurodevelopmental impairment, impaired lung growth, and childhood cancer. Early-life exposures to plastic-associated chemicals also increase the risk of multiple non-communicable diseases later in life.

Economic Findings

Plastic's harms to human health result in significant economic costs. We estimate that in 2015 the health-related costs of plastic production exceeded $250 billion (2015 Int$) globally, and that in the USA alone the health costs of disease and disability caused by the plastic-associated chemicals PBDE, BPA and DEHP exceeded $920 billion (2015 Int$). Plastic production results in greenhouse gas (GHG) emissions equivalent to 1.96 gigatons of carbon dioxide (CO2e) annually. Using the US Environmental Protection Agency's (EPA) social cost of carbon metric, we estimate the annual costs of these GHG emissions to be $341 billion (2015 Int$).These costs, large as they are, almost certainly underestimate the full economic losses resulting from plastics' negative impacts on human health and the global environment. All of plastics' economic costs-and also its social costs-are externalized by the petrochemical and plastic manufacturing industry and are borne by citizens, taxpayers, and governments in countries around the world without compensation.

Social Justice Findings

The adverse effects of plastics and plastic pollution on human health, the economy and the environment are not evenly distributed. They disproportionately affect poor, disempowered, and marginalized populations such as workers, racial and ethnic minorities, "fenceline" communities, Indigenous groups, women, and children, all of whom had little to do with creating the current plastics crisis and lack the political influence or the resources to address it. Plastics' harmful impacts across its life cycle are most keenly felt in the Global South, in small island states, and in disenfranchised areas in the Global North. Social and environmental justice (SEJ) principles require reversal of these inequitable burdens to ensure that no group bears a disproportionate share of plastics' negative impacts and that those who benefit economically from plastic bear their fair share of its currently externalized costs.

Conclusions

It is now clear that current patterns of plastic production, use, and disposal are not sustainable and are responsible for significant harms to human health, the environment, and the economy as well as for deep societal injustices.The main driver of these worsening harms is an almost exponential and still accelerating increase in global plastic production. Plastics' harms are further magnified by low rates of recovery and recycling and by the long persistence of plastic waste in the environment.The thousands of chemicals in plastics-monomers, additives, processing agents, and non-intentionally added substances-include amongst their number known human carcinogens, endocrine disruptors, neurotoxicants, and persistent organic pollutants. These chemicals are responsible for many of plastics' known harms to human and planetary health. The chemicals leach out of plastics, enter the environment, cause pollution, and result in human exposure and disease. All efforts to reduce plastics' hazards must address the hazards of plastic-associated chemicals.

Recommendations

To protect human and planetary health, especially the health of vulnerable and at-risk populations, and put the world on track to end plastic pollution by 2040, this Commission supports urgent adoption by the world's nations of a strong and comprehensive Global Plastics Treaty in accord with the mandate set forth in the March 2022 resolution of the United Nations Environment Assembly (UNEA).International measures such as a Global Plastics Treaty are needed to curb plastic production and pollution, because the harms to human health and the environment caused by plastics, plastic-associated chemicals and plastic waste transcend national boundaries, are planetary in their scale, and have disproportionate impacts on the health and well-being of people in the world's poorest nations. Effective implementation of the Global Plastics Treaty will require that international action be coordinated and complemented by interventions at the national, regional, and local levels.This Commission urges that a cap on global plastic production with targets, timetables, and national contributions be a central provision of the Global Plastics Treaty. We recommend inclusion of the following additional provisions:The Treaty needs to extend beyond microplastics and marine litter to include all of the many thousands of chemicals incorporated into plastics.The Treaty needs to include a provision banning or severely restricting manufacture and use of unnecessary, avoidable, and problematic plastic items, especially single-use items such as manufactured plastic microbeads.The Treaty needs to include requirements on extended producer responsibility (EPR) that make fossil carbon producers, plastic producers, and the manufacturers of plastic products legally and financially responsible for the safety and end-of-life management of all the materials they produce and sell.The Treaty needs to mandate reductions in the chemical complexity of plastic products; health-protective standards for plastics and plastic additives; a requirement for use of sustainable non-toxic materials; full disclosure of all components; and traceability of components. International cooperation will be essential to implementing and enforcing these standards.The Treaty needs to include SEJ remedies at each stage of the plastic life cycle designed to fill gaps in community knowledge and advance both distributional and procedural equity.This Commission encourages inclusion in the Global Plastic Treaty of a provision calling for exploration of listing at least some plastic polymers as persistent organic pollutants (POPs) under the Stockholm Convention.This Commission encourages a strong interface between the Global Plastics Treaty and the Basel and London Conventions to enhance management of hazardous plastic waste and slow current massive exports of plastic waste into the world's least-developed countries.This Commission recommends the creation of a Permanent Science Policy Advisory Body to guide the Treaty's implementation. The main priorities of this Body would be to guide Member States and other stakeholders in evaluating which solutions are most effective in reducing plastic consumption, enhancing plastic waste recovery and recycling, and curbing the generation of plastic waste. This Body could also assess trade-offs among these solutions and evaluate safer alternatives to current plastics. It could monitor the transnational export of plastic waste. It could coordinate robust oceanic-, land-, and air-based MNP monitoring programs.This Commission recommends urgent investment by national governments in research into solutions to the global plastic crisis. This research will need to determine which solutions are most effective and cost-effective in the context of particular countries and assess the risks and benefits of proposed solutions. Oceanographic and environmental research is needed to better measure concentrations and impacts of plastics <10 µm and understand their distribution and fate in the global environment. Biomedical research is needed to elucidate the human health impacts of plastics, especially MNPs.

Summary

This Commission finds that plastics are both a boon to humanity and a stealth threat to human and planetary health. Plastics convey enormous benefits, but current linear patterns of plastic production, use, and disposal that pay little attention to sustainable design or safe materials and a near absence of recovery, reuse, and recycling are responsible for grave harms to health, widespread environmental damage, great economic costs, and deep societal injustices. These harms are rapidly worsening.While there remain gaps in knowledge about plastics' harms and uncertainties about their full magnitude, the evidence available today demonstrates unequivocally that these impacts are great and that they will increase in severity in the absence of urgent and effective intervention at global scale. Manufacture and use of essential plastics may continue. However, reckless increases in plastic production, and especially increases in the manufacture of an ever-increasing array of unnecessary single-use plastic products, need to be curbed.Global intervention against the plastic crisis is needed now because the costs of failure to act will be immense.

GPER and Testicular Germ Cell Cancer

The G protein-coupled estrogen receptor (GPER), also known as GPR30, is a widely conserved 7-transmembrane-domain protein which has been identified as a novel 17β-estradiol-binding protein that is structurally distinct from the classic oestrogen receptors (ERα and ERβ). There are still conflicting data regarding the exact role and the natural ligand of GPER/GPR30 in reproductive tracts as both male and female knock-out mice are fertile and have no abnormalities of reproductive organs. Testicular germ cell cancers (TGCCs) are the most common malignancy in young males and the most frequent cause of death from solid tumors in this age group. Clinical and experimental studies suggested that estrogens participate in the physiological and pathological control of male germ cell proliferation. In human seminoma cell line, while 17β-estradiol (E2) inhibits in vitro cell proliferation through an ERβ-dependent mechanism, an impermeable E2 conjugate (E2 coupled to BSA), in vitro cell proliferation is stimulated by activating ERK1/2 and protein kinase A through a membrane GPCR that we further identified as GPER/GPR30. The same effect was observed with low but environmentally relevant doses of BPA, an estrogenic endocrine disrupting compound. Furthermore, GPER/GPR30 is specifically overexpressed in seminomas but not in non-seminomas and this overexpression is correlated with an ERβ-downregulation. This GPER/GPR30 overexpression could be linked to some genetic variations, as single nucleotide polymorphisms, which was also reported in other hormone-dependent cancers. We will review here the implication of GPER/GPR30 in TGCCs pathophysiology and the arguments to consider GPER/GPR30 as a potential therapeutic target in humans.

Isolated follicle-stimulating hormone (FSH) deficiency in two infertile men without FSH β gene mutation: Case report and literature review

OBJECTIVE

Congenital FSH deficiency is an exceptional cause of male infertility most often attributed to FSH β gene mutations. The few published cases report azoospermia, severe testicular hypotrophy and normal testosterone levels associated with normal virilization. We report the exploration of two young men aged 26 and 27 years with severe sperm abnormalities, moderate testicular hypotrophy and isolated FSH deficiency.

METHODS

Several FSH, LH, total testosterone and inhibin B assays and FSH β gene sequencing were performed.

RESULTS

FSH was almost undetectable at baseline and poorly responsive to GnRH test, whereas LH was normal at baseline and increased after GnRH test. Testosterone levels were within the adult range, while inhibin B levels were upper-normal to high. No FSH β gene mutations were found. Exogenous FSH treatment was followed by spontaneous pregnancy in one case and required intra-cytoplasmic sperm injection (ICSI) in the other.

CONCLUSIONS

The paradoxical high levels of inhibin B reflect the presence of functional Sertoli cells and may explain the isolated FSH deficiency. An intra-gonadal factor stimulating inhibin B secretion is discussed.

Which origin for polycystic ovaries syndrome: Genetic, environmental or both?

Polycystic ovaries syndrome (PCOS), the most common female endocrine disorder, affects 7-10% of women of childbearing age. It includes ovarian hyperandrogenism, impaired follicular maturation, anovulation and subfertility. Insulin resistance, although present in most cases, is not necessary for diagnosis. It increases hyperandrogenism and long-term metabolic, cardiovascular and oncological risks. The origin of hyperandrogenism and hyperinsulinemia has a genetic component, as demonstrated by familial aggregation studies and recent identification of associated genomic variants, conferring a particular susceptibility to the syndrome. However, experimental and epidemiological evidences also support a developmental origin via a deleterious foetal environment, concerning the endocrine status (foetal hyperandrogenism), the nutritional level (intrauterine growth retardation), or the toxicological exposure (endocrine disruptors). Epigenetic changes recently reported in the literature as associated with PCOS, enhance this hypothesis of foetal reprogramming of the future adult ovarian function by environmental factors. Better characterisation of these genetic, epigenetic, or environmental factors, could lead to earlier prevention and more efficient treatments.

Delayed diagnosis of Sheehan's syndrome in a developed country: a retrospective cohort study

BACKGROUND

Little is known about Sheehan's syndrome (SS), even though it is believed that its incidence is low. The aims of this study were to determine the clinical features and diagnostic delay of SS and to ascertain whether early signs could have allowed earlier diagnosis.

SUBJECTS AND METHODS

All patients with SS diagnosed in reference units in the southeast of France between 1980 and 2011 were recruited for this study. Data on obstetrical history, clinical symptoms suggestive of hypopituitarism, early signs, hormone analysis, and magnetic resonance imaging were collected.

RESULTS

Of the 40 women found to have SS, 39 were studied. Mean delay in the diagnosis of SS was 9 ± 9.7 years. We found that four of the 35 assessable patients were diagnosed with agalactia, 16 of the 29 assessable ones with amenorrhea, 19 of the 39 with hypothyroidism, eight with acute adrenal insufficiency, and 15 with asthenia. Among the patients for whom there was a diagnostic delay of more than 1 year (n=28), seven had headaches during the postpartum period, all assessable patients had agalactia, six of the 22 assessable ones had amenorrhea, seven of 28 had hypothyroidism, and 12 of 28 had asthenia.

CONCLUSION

Most signs of SS are aspecific and classical signs such as agalactia and amenorrhea are often difficult to detect, which can explain the long diagnostic delay. We suggest that all women failing to lactate after postpartum hemorrhage (PPH) should be evaluated by measuring prolactin levels and women with signs such as amenorrhea and asthenia, even several years after PPH, should undergo a blood test including assessment of thyroxine, TSH, 0800  h ACTH-cortisol, and IGF1 levels.

Imbalance of MMP-2 and MMP-9 expression versus TIMP-1 and TIMP-2 reflects increased invasiveness of human testicular germ cell tumours

The histological classification of testicular germ cell tumours (TGCTs) to seminoma or non-seminomatous germ cell tumours is at present the main criterion for the clinical outcome and selection of the treatment strategy. In view of the need to identify novel prognostic biomarkers for TGCTs, we investigated the expression of the matrix metalloproteinases MMP-2 and MMP-9 in testicular tumour tissues and cell lines of both seminoma and non-seminoma origin. Immunohistochemistry and zymography analysis of tumoural tissues showed significantly higher levels of MMP-2 and MMP-9 compared with normal testis with the active forms detected only in the tumour tissues. Three cell lines representative of the different tumour types, JKT-1 seminoma, NCCIT teratocarcinoma and NTERA2/D1 embryonal carcinoma were also evaluated for their expression of these MMPs using qPCR and zymography and for their invasive properties. The more invasive non-seminomatous teratocarcinoma and embryonal cells expressed considerably more MMP-2 and MMP-9 compared with seminoma cells exhibiting lower invasiveness. Furthermore, an inverse relation was observed between invasiveness and the expression of endogenous inhibitors TIMP-1 and TIMP-2. The MMP inhibitor Marimastat inhibited invasion in all cell lines, the highest inhibition was observed in the more invasive NTERA2/D1 and NCCIT cells, which presented the highest ratio of MMP-2 and MMP-9 vs. TIMP-1 and TIMP-2. These results highlight the importance of MMP-2 and MMP-9 in the invasiveness of testicular tumours and suggest that their levels, vs. those of TIMP-1 and TIMP-2, may represent potential biomarkers for testicular malignancy.

Delayed puberty

Since puberty is a long ongoing developmental process with significant individual and population differences in timing, the definition of delayed puberty for a given individual needs to rest on simple, though arbitrary criteria based on epidemiological data. Although several genes involved in the hypothalamic-pituitary-gonadal maturation cascade have been characterized recently from familial or sporadic cases of primitive isolated hypogonadotropic hypogonadism, many genes regulating puberty onset remain undetermined. In case of delayed puberty and/or primary amenorrhea, a complete clinical examination including a detailed past history will evaluate the development of secondary sex characteristics, verify the association with a growth delay and look for specific indicative features pertaining to the etiological diagnosis. This clinical check-up completed if necessary with biological, ultrasonographic, radiological and genetic investigations will try to determine which girls will have a permanent sexual infantilism of gonadal, hypophyseal or hypothalamic origin, which girls will undergo spontaneous but delayed puberty and which girls have primary amenorrhea with developed secondary sex characteristics. Therapeutic attitude will have to integrate etiological factors, statural prognosis, bone mass preservation and psychological factors.

Cord blood thyroid tests in boys born with and without cryptorchidism: correlations with birth parameters and in utero xenobiotics exposure

BACKGROUND

In utero exposure to environmental chemicals can result in reproductive toxicity via endocrine disruption mechanisms. Whether some of those contaminants also have an impact on fetal thyroid function or pathways, and, thus, potentially on neuropsychological development, is still debated.

METHODS

We used samples from a cord blood (CB) and milk bank, established for a research on cryptorchidism and xenobiotic exposure to compounds known for their anti-androgenic and/or estrogenic activity, to study CB thyroid tests and their correlation with CB and milk xenobiotics concentrations in boys born in Nice area.

RESULTS

No difference was found in thyroid tests between 60 cryptorchid boys and 76 matched controls (median thyroid stimulating hormone 5.97 vs. 6.55 mUI/L, free thyroxine [fT4] 13.1 vs. 12.9 pmol/L, free triiodothyronine [fT3] 1.9 vs. 2.1 pmol/L), with no influence of season of birth, gestational age, maternal smoking, or mode of delivery (except for higher fT4 in control boys born vaginally). FT4 was correlated with fetal growth only in cryptorchid boys. Since we had previously shown differences between cryptorchid and controls exposure, we studied correlations of thyroid tests with xenobiotics in control boys only. All tested CB or maternal milk was contaminated by one or more selected xenobiotics, mainly polychlorinated biphenyls (PCBs), dichloro diphenyl dichloroethylène (DDE), dibutylphthalate, hexachlorobenzene, and bisphenol A. We found a significant negative correlation between fT4 and concentrations of PCB118, PC180, and DDE in milk (respectively r = -0.342, p < 0.03, r = -0.296, p = 0.031, r = -0.315, p = 0.016), persisting after adjustment for mode of delivery. There was a significant positive correlation of fT3 with milk concentrations of PCB138, PCB153, ΣPCB, and dibutylphthalate (respectively r = 0.31, p = 0.016, r = 0.28, p = 0.029; r = 0.34, p = 0.0079 and r = 0.272, p = 0.0295), with a trend for PCB180 (r = 0.259, p = 0.061). There was no correlation of thyroid stimulating hormone with any of the measured xenobiotics, except for a weak negative trend with CB bisphenol A (r = -0.25, p = 0.077).

CONCLUSIONS

CB thyroid tests are within normal range in cryptorchid boys, similar to controls. Our data in controls suggest a possible weak correlation between in utero exposure to some xenobiotics (PCBs, DDE) and fT3 and fT4 CB concentrations, with usually negative correlations with fT4 and positive with fT3 concentrations, which we speculate could suggest an impact on deiodinases.

Role of GPER/GPR30 in tumoral testicular germ cells proliferation

In a recent issue of Cancer Biology & Therapy, Vitale et al. introduced the paper of Franco et al. reporting the expression of GPER (a seven-transmembrane-spanning receptor also known as GPR30) on testicular germ cell tumors (TGCTs). The paper commented on the possible pathophysiological role of this G-protein-coupled receptor (GPCR) during testicular germ cell carcinogenesis. They also proposed the potential use of selective antagonists of GPER as new-targeted therapy in these tumors. We agree with this hypothesis and would like to highlight here some published results supporting this hypothesis and give some details concerning the role of estrogens and xeno-estrogens in testicular carcinogenesis and the effects of GPER antagonist in human seminoma cells. We are sure that this information we obtained by working for several years on a human seminoma cell line will be appreciated by the readers of Cancer Biology & Therapy.

Phenotypical, biological, and molecular heterogeneity of 5α-reductase deficiency: an extensive international experience of 55 patients

CONTEXT

In 46,XY disorders of sex development, 5α-reductase deficiency is rare and is not usually the first-intention diagnosis in newborn ambiguous genitalia, contrary to partial androgen insensitivity syndrome. Yet the cause of ambiguous genitalia may guide sex assignment, and rapid, precise diagnosis of 5α-reductase deficiency is essential.

OBJECTIVE

The aim of the study was to describe relevant data for clinical diagnosis, biological investigation, and molecular determination from 55 patients with srd5A2 mutations identified in our laboratory over 20 yr to improve early diagnosis.

SETTING

The study was performed at Montpellier University Hospital.

PATIENTS

We studied a cohort of 55 patients with srd5A2 gene mutations.

MAIN OUTCOME MEASURE(S)

Genetic analysis of srd5A2 was conducted.

RESULTS

Clitoromegaly (49.1%) and microphallus with various degrees of hypospadias (32.7%) were frequent phenotypes. Female external genitalia (7.3%) and isolated micropenis (3.6%) were rare. Seventy-two percent of patients were initially assigned to female gender; five of them (12.5%) switched to male sex in peripuberty. Over 72% of patients were considered for 5α-reductase deficiency diagnosis when the testosterone/dihydrotestosterone cutoff was 10. In 55 patients (with 20 having a history of consanguinity), we identified 33 different mutations. Five have never been reported: p.G32S, p.Y91H, p.G104E, p.F223S, and c.461delT. Homozygous mutations were present in 69.1% of cases, compound heterozygous mutations in 25.5%, and compound heterozygous mutations alone with the V89L polymorphism in 5.4%. Exons 1 and 4 were most affected, with 35.8 and 21.7% mutant alleles per exon, respectively.

CONCLUSIONS

In the largest cohort to date, we demonstrate a wide spectrum of phenotypes and biological profiles in patients with 5α-reductase deficiency, whatever their geographical or ethnic origins.

Lethal acute demyelinization with encephalo-myelitis as a complication of cured Cushing's disease

Cushing's disease is usually associated with higher mortality rate, especially from cardiovascular causes. Development or exacerbation of autoimmune or inflammatory diseases is known to occur in patients with hypercortisolism after cure. We report for the first time a 34-year old woman with a psychiatric background, who developed four months after the surgical cure of Cushing's disease an acute disseminated encephalomyelitis (ADEM) presenting initially as a psychiatric illness. We hypothesize that the recent correction of hypercortisolism triggered ADEM and that the atypical presentation, responsible for diagnosis delay, led to the death of this patient.

[Oncofertility: a new focus in women health-care...]

Although treatment and survival are the primary focus of health-care patients, with cancer survivors living longer it is now appropriate to consider their quality of life after treatment, including the possibility of becoming parents. There are several options for fertility preservation in cancer patients. Even though most of them are still experimental and their efficacy and reliability have not been determined, especially in women. The most successful alternative for female survivors is embryo cryopreservation, an approach not suitable for many single or virgin women or even possible for prepubertal girls. Reports of live birth after transplantation of human ovarian tissue have reinforced the clinical potential of ovarian tissue banking for fertility preservation. Many exciting studies are underway to improve the efficacy and solve the problems with current fertility preservation strategies, especially for in vitro culture of cryopreserved tissue or follicles. Continuous efforts to improve current strategies and to develop new strategies will benefit many women and children who are facing premature ovarian failure and sterility.

The orphan nuclear receptor small heterodimer partner mediates male infertility induced by diethylstilbestrol in mice

Studies in rodents have shown that male sexual function can be disrupted by fetal or neonatal administration of compounds that alter endocrine homeostasis, such as the synthetic nonsteroidal estrogen diethylstilbestrol (DES). Although the molecular basis for this effect remains unknown, estrogen receptors likely play a critical role in mediating DES-induced infertility. Recently, we showed that the orphan nuclear receptor small heterodimer partner (Nr0b2), which is both a target gene and a transcriptional repressor of estrogen receptors, controls testicular function by regulating germ cell entry into meiosis and testosterone synthesis. We therefore hypothesized that some of the harmful effects of DES on testes could be mediated through Nr0b2. Here, we present data demonstrating that Nr0b2 deficiency protected mice against the negative effects of DES on testis development and function. During postnatal development, Nr0b2-null mice were resistant to DES-mediated inhibition of germ cell differentiation, which may be the result of interference by Nr0b2 with retinoid signals that control meiosis. Adult Nr0b2-null male mice were also protected against the effects of DES; however, we suggest that this phenomenon was due to the removal of the repressive effects of Nr0b2 on steroidogenesis. Together, these data demonstrate that Nr0b2 plays a critical role in the pathophysiological changes induced by DES in the mouse testis.

Low doses of bisphenol A promote human seminoma cell proliferation by activating PKA and PKG via a membrane G-protein-coupled estrogen receptor

BACKGROUND

Fetal exposure to environmental estrogens may contribute to hypofertility and/or to testicular germ cell cancer. However, many of these xenoestrogens have only a weak affinity for the classical estrogen receptors (ERs,) which is 1,000-fold less potent than the affinity of 17beta-estradiol (E(2)). Thus, several mechanisms have been suggested to explain how they could affect male germ cell proliferation at low environmental relevant concentrations.

OBJECTIVES

In this study we aimed to explore the possible promoting effect of bisphenol A (BPA) on human testicular seminoma cells. BPA is a well-recognized estrogenic endocrine disruptor used as a monomer to manufacture poly carbonate plastic and released from resin-lined food or beverage cans or from dental sealants.

METHODS AND RESULTS

BPA at very low concentrations (10(-9) to 10(-12) M) similar to those found in human fluids stimulated JKT-1 cell proliferation in vitro. BPA activated both cAMP-dependent protein kinase and cGMP-dependent protein kinase pathways and triggered a rapid (15 min) phosphorylation of the transcription factor cAMP response-element-binding protein (CREB) and the cell cycle regulator retinoblastoma protein (Rb). This nongenomic activation did not involve classical ERs because it could not be reversed by ICI 182780 (an ER antagonist) or reproduced either by E(2) or by diethylstilbestrol (a potent synthetic estrogen), which instead triggered a suppressive effect. This activation was reproduced only by E(2) coupled to bovine serum albumin (BSA), which is unable to enter the cell. As with E(2)-BSA, BPA promoted JKT-1 cell proliferation through a G-protein-coupled nonclassical membrane ER (GPCR) involving a Galpha(s) and a Galpha(i)/Galpha(q) subunit, as shown by the reversible effect observed by the corresponding inhibitors NF449 and pertussis toxin.

CONCLUSION

This GPCR-mediated nongenomic action represents--in addition to the classical ER-mediated effect--a new basis for evaluating xenoestrogens such as BPA that, at low doses and with a high affinity for this GPCR, could interfere with the developmental programming of fetal germ cell proliferation and/or differentiation when they cross the placenta.

Estrogens promote human testicular germ cell cancer through a membrane-mediated activation of extracellular regulated kinase and protein kinase A

Clinical and experimental studies have suggested that estrogens, the archetype of female hormones, participate in the control of male germ cell proliferation and that fetal exposure to environmental estrogens may contribute to hypofertility and/or to testicular germ cell cancer. However, the underlying mechanisms remain to be elucidated. 17beta-Estradiol (E2) conjugated to BSA was able to stimulate human testicular seminoma cell proliferation by triggering a rapid, nongenomic, membrane-mediated activation of ERK1/2 and cAMP-dependent protein kinase A (PKA). Both ERK1/2 and PKA participated in this promoting effect. This activation was associated with phosphorylation of the transcription factor cAMP response element-binding protein and the nuclear factor retinoblastoma protein. Enhanced proliferation together with ERK activation could be reversed by pertussis toxin, a G protein inhibitor. Estrogen receptors (ERs) in JKT-1 were characterized by immunofluorescence, subcellular fractioning, and Western blot. JKT-1 cells did not express ERalpha but ERbeta, which localized to the mitochondria and the nucleus but not to the membrane. Moreover, neither ICI-182,780, a classical ER antagonist, nor tamoxifen, a selective ER modulator, could reverse the 17beta-estradiol-BSA-induced promoting effect. Estrogens contribute to human testicular germ cell cancer proliferation by rapid activation of ERK1/2 and PKA through a membrane nonclassical ER. This nongenomic effect represents a new basis for understanding the estrogenic control of spermatogenesis and evaluating the role of fetal exposure to xenoestrogens during malignant transformation of testicular germ stem cells.

Adrenal tuberculosis after a pheochromocytoma: a misleading tumoral presentation

Adrenal gland involvement could account for 6% of active tuberculosis. The diagnosis of this extrapulmonary form of tuberculosis is difficult, especially when presenting as unilateral adrenal tumor. This report describes an unusual case of adrenal tuberculosis presenting as a tumor occurring shortly after surgical removal of an adrenal pheochromocytoma located in the opposite gland, in a 63-year-old woman with a previous history of breast cancer. At initial presentation, the patient suffered from symptomatic paroxysmal hypertension. A pheochromocytoma in the left adrenal was diagnosed and resected. One year later, while physical examination and biological parameters were unremarkable, an enhanced adrenal computed tomography (CT) scan showed a right adrenal mass mimicking the CT features of the resected pheochromocytoma. A peripheral tissular rim delineating a central hypodensity characterized this tumor. Magnetic resonance imaging (MRI) showed the same findings on gadolinium-enhanced T1-weighted slices, while the mass was not seen on T2-weighted images. No tumoral signal loss was observed on out of phase images when using the in phase-out of phase T1-weighted sequence. Because of the tumoral evolution and the uncertainty of the nature of that lesion, the patient underwent a second adrenalectomy. Definitive diagnosis was provided by culture of tissue sample, which resulted in the identification of Mycobacterium tuberculosis. In an era of tuberculosis resurgence, this unusual case underscores the necessity of keeping in mind adrenal tuberculosis as a possible differential diagnosis in adrenal tumors of uncertainty nature. It stresses the importance of culture of biopsy tumor, whenever feasible, to avoid unnecessary operations. In the near future, interferon-gamma assay could be a valuable means to recognize extrapulmonary forms of tuberculosis.

Goitre ovarien malin: faux positif du TEP-scan lié à une sarcoïdose

Struma ovarii is an ovarian teratoma mainly composed of thyroid tissue, which can become malignant with possible peritoneal dissemination or even distant metastases. Therapeutic management follows protocols used for thyroid cancer. We report the first use of (18)F-fluorodeoxyglucose positron emission tomography (PET) in the follow-up of malignant struma ovarii with persistently elevated serum thyroglobulin level and negative diagnostic iodine 131 whole body scan after thyroidectomy and four courses of 131 iodine. Hilar and mediastinal lymph node uptake was detected but histological verification concluded that there was a false-positive localization corresponding to sarcoidosis lesions without malignant aspect.

Estrogen-induced growth inhibition of human seminoma cells expressing estrogen receptor beta and aromatase

It is now well established that estrogens participate in the control of normal spermatogenesis and endogenous or environmental estrogens are involved in pathological germ cell proliferation including testicular germ cell tumors. Studying a human testicular seminoma cell line, JKT-1, we show here that 17beta-estradiol (10(-12) to 10(-6) M) induced in vitro a significant dose-dependent decrease of cell growth. This antiproliferative effect was maximum after 4 days of exposure at a physiologically intratesticular concentration of 10(-9) M, close to the K(d) of ER, and reversed by ICI 182780, an ER antagonist, suggesting an ER-mediated pathway. By RT-PCR and Western blot we were able to confirm that JKT-1, like tumoral seminoma cells and normal human testicular basal germ cells, expresses estrogen receptor beta (ERbeta), including ERbeta1 and ERbeta2, a dominant negative variant, but not ERalpha. Using immunofluorescence and confocal microscopy, ERbeta was observed as perinuclear intracytoplasmic spots in JKT-1 and tumoral seminoma cells without significant translocation of ERbeta into the nucleus, under 17beta-estradiol exposure. Double staining observed by confocal microscopy revealed that ERbeta colocalized in JKT-1 cells with cytochrome C, a mitochondrial marker. We report for the first time the expression of a functional aromatase complex in seminoma cells as assessed by RT-PCR, Western blot and enzymatic assay. Seminoma cells are able to respond to estrogens through a possible autocrine or paracrine loop. These preliminary results support estrogen-dependency of human testicular seminoma, the most frequent tumor of young men, and suggest potential pharmacological use. Whether this estrogen control, however, involves an ERbeta-mediated stimulation of cell apoptosis and/or an ERbeta-mediated inhibition of cell proliferation, remains to be further determined.

Disrupted traffic of connexin 43 in human testicular seminoma cells: overexpression of Cx43 induces membrane location and cell proliferation decrease

Connexins, the constitutive proteins of gap junctions, are considered to be tumour suppressive agents and are often impaired in the tumourigenic processes. In the present study, the expression of connexin 43 (Cx43), which is involved in the control of spermatogenesis through Sertoli/germ cell coupling, has been investigated in human testicular seminoma cells (tumours and the JKT-1 cell line). Cx43 was immunolocalized in the Golgi apparatus without membrane expression and was detected by immunoblotting in JKT-1 as exclusive 70 kD bands. No mutation could be found by sequencing the transcript obtained by RT-PCR. Transfection with a Cx43-V5 vector reproduced the same gel shift, identifying these 70 kD bands as Cx43. The Cx43-70 kD bands were also expressed in normal testicular tissue, associated with the classical 43 kD isoforms. Stable transfection of JKT-1 with a Cx43-GFP vector allowed restoration of Cx43 membrane expression, functional cell coupling, and inhibition of the cell proliferation rate. Storage of Cx43 in the Golgi apparatus may correspond during spermatogenesis to an intermittent physiological process that becomes permanent in malignant seminoma cells as a result of the tumourigenic process. By preventing Cx43 membrane expression, this disrupted traffic may itself participate in tumour promotion.

Sequestration of connexin43 in the early endosomes: An early event of Leydig cell tumor progression

Connexins form gap junction channels that allow intercellular communication between neighboring cells. Compelling evidence has revealed that Cx are tumor-suppressor genes and reduced Cx expression has been related with uncontrolled cell growth in tumors and transformed cells. In the present study, we addressed Cx transcriptional and posttranscriptional regulations during the earlier stage of testicular tumors confined to Leydig cells in a transgenic mice model. In situ hybridization indicated that connexin43 (Cx43) mRNA was highly expressed either at early tumorogenesis (3 m) characterized by intense proliferation of Leydig cells, or at advanced tumorogenesis (6-7 m) when tumor cells completely invaded the testis. In contrast, Cx43 protein analyzed by Western blotting or classic immunohistochemical analyses was present at the beginning of tumor progression, but was dramatically reduced as tumor advanced. Application of high-resolution deconvolution microscopy to testis sections demonstrates that cells that proliferate exhibited an aberrant cytoplasmic Cx43 localization, in contrast to the expected plasma membrane Cx43 localization in normal Leydig cells. Dual immunofluorescence labeling with specific markers of cellular compartments shows that cytoplasmic Cx43 signal was mainly sequestered within early endosomes. Altogether, this study provides the first evidence that impaired Cx43 trafficking in endosomes is an early event associated with uncontrolled cell proliferation that could serve as a neoplastic marker.

Update on cryptorchidism: endocrine, environmental and therapeutic aspects

Cryptorchidism is the most frequent developmental abnormality in boys, present in more than 1% of infants above three months of age. It is associated with an increased risk of infertility and testicular cancer. The etiological quest is often disappointing, except in bilateral cases or associated malformations. Recent focus is on genetic and environmental aspects. Animal models have revealed the role of genes encoding for proteins implicated in testicular migration (InsI3, Hoxa 10), but in humans results are less convincing. While some degree of endogenous hormonal abnormality is suspeeted in some patients, the endocrine disruptor hypothesis is also tested. It is unclear whether the incidence of cryptorchidism has really increased, or whether there is only a better screening for this condition. However, other male reproductive problems, such as subfertility, hypospadias and testicular cancer seem on the rise. This secular trend suggests the possible in utero impact of hormonally active environmental factors, such as pesticides with estrogenic or antiandrogenic effect, and is consistent with the increased risk of cryptorchidism observed in the sons of mothers exposed to diethylstilbestrol during pregnancy. From a therapeutic point of view, there is an agreement that the correction of cryptorchidism is needed, but there is controversy on the best medical and/or surgical approach and on the optimal timing. There is a recent trend in proposing early therapeutic intervention, before 1 yr of age, in the hope of improving fertility; however, there is no proof that such a strategy can reduce the risk of testicular cancer.

[Male infertility due to azoospermia and in vitro fertilization assisted by ICSI. Findings based on a prospective study of our first 42 patients]

INTRODUCTION

Our experience of ICSI began in 1997. This study reviews our four-year experience based on 42 consecutive couples.

MATERIAL AND METHOD

Between February 1997 and December 2000, 42 sterile couples due to male infertility were treated by ICSI. Surgical exploration and "open" gamete collection were proposed regardless of the predefined type of azoospermia, obstructive or non-obstructive.

RESULT

Seventy one cycles were performed: ICSI used epididymal spermatozoa in 49 cycles, and testicular spermatozoa in 22 cycles. The fertilization rate was 76% for fresh semen and 87% for frozen semen. The fertilization rate was 88% for epididymal spermatozoa and 68% for testicular spermatozoa. 13 pregnancies were obtained (18.3%), 11 babies were born at term including 3 twin pregnancies. No significant difference was observed between fresh and frozen semen, or between obstructive and non-obstructive azoospermia.

CONCLUSION

IVF-ICSI applied to sterility due to male infertility has revolutionized the management of sterile couples. However, as for any new procedure in medicine, we must be vigilant, as a sufficient follow-up is necessary to definitively evaluate the safety of ICSI, especially in terms of the risk of genetic abnormalities.

Disruption of gap junctional intercellular communication by lindane is associated with aberrant localization of connexin43 and zonula occludens-1 in 42GPA9 Sertoli cells

Lindane (gamma-hexachlorocyclohexane) is a lipid-soluble pesticide that exerts carcinogenic and reprotoxic properties. The mechanisms by which lindane alters testicular function are unclear. Sertoli cells control germ cell proliferation and differentiation through cell-cell communication, including gap junction intercellular communication. Using the 42GPA9 Sertoli cell line, we show that lindane, at a non-cytotoxic dose (50 microM), abolished gap junction intercellular communication (GJIC) between adjacent cells. This change was associated with a time-related diminution and redistribution of Cx43 from the membrane to the cytoplasmic perinuclear region. A similar alteration was observed for ZO-1, a tight junction component associated with Cx43, but not for occludin, an integral tight junction protein. After a 24 h lindane exposure, Cx43 and ZO-1 colocalized within the cytoplasm and no modification of non-phosphorylated and phosphorylated isoforms of Cx43 was observed. By double immunofluorescent labelling we demonstrate that the cytoplasmic Cx43 signal was not present in either the endoplasmic reticulum/Golgi apparatus or lysosomes. These results suggest that lindane inhibits GJIC between Sertoli cells and that aberrant Cx43/ZO-1 localization may be responsible for this effect. The alterations in gap junctions induced by lindane in 42GPA9 Sertoli cells are similar to those observed in tumour cells and may be involved in the pathogenesis of neoplastic seminomal proliferation.

Mapping of seminal plasma proteins by two-dimensional gel electrophoresis in men with normal and impaired spermatogenesis

The present study analyses differential polypeptide expression of seminal plasma from fertile and infertile men by two-dimensional gel electrophoresis. Optimization of solubilization of seminal plasma was obtained by using [3-(3-(cholamidopropyl) dimethyl-ammonio)-1-propane sulphonate] and chaotropic agent mixture in lysis buffer before separation in immobilized pH gradient for isoelectric focusing. A two-dimensional map of seminal plasma from a fertile man allowed the detection of about 750 spots. Semi-preparative electrofocusing was performed. Analysis of tryptic fragments of two major spots by matrix-assisted laser desorption-ionization time-of-flight (MALDI-TOF) mass spectroscopy resulted in identification of prostatic acid phosphatase and prostate specific antigen. Three groups of spots and seven individual spots of isoelectric point from 4.6 to 6.2 and mol. wt from 41 to 18 kDa disappeared in the two-dimensional maps of seminal plasma of vasectomized men (n = 4) and of a patient with bilateral anorchidy as compared to that of fertile men (n = 5). Some of these polypeptides were also absent in seminal plasma of patients with alterations of seminiferous tubules showing Sertoli cell-only syndrome characteristics (n = 4) and could be potential diagnostic markers of spermatogenesis impairment.

Hypothalamic-pituitary Langerhans cell histiocytosis: a diagnostic challenge

Four cases of hypothalamic-pituitary Langerhans cell histiocytosis (LCH) are reported, highlighting the expanding spectrum of clinical and magnetic resonance imaging (MRI) features in adults. The diagnostic challenge of hypothalamic-pituitary LCH is emphasized in cases revealed as supra-sellar tumors with panhypopituitarism or as isolated central diabetes insipidus. Diagnosis is confirmed by histological examination showing infiltration with CD1a positive histiocytes. General guidelines for diagnosis procedure are drawn out, including the neurosurgical biopsy in particular cases.

Modified expression of testicular gap-junction connexin 43 during normal spermatogenic cycle and in altered spermatogenesis

In order to better understand the implications of gap junction proteins in spermatogenesis, connexin 43 (Cx43), the most abundant connexin in the testis, was evaluated in testes of wild-type mice and of two mutants with impaired spermatogenesis (ebo/ebo, and jun-d-/-mice). Reverse transcription-polymerase chain reaction (RT-PCR) amplification revealed a constitutive expression of mRNA for Cx43 in both wild-type mice and infertile mutants. In the seminiferous tubules of wild-type mice, indirect immunofluorescence revealed that Cx43 expression was stage-dependent and that the signal was mainly located in the region of Sertoli cell occluding junctions. Colocalization of Cx43 and of the tight-junction-associated protein zonula occludens 1 (ZO-1) was demonstrated in seminiferous tubules by using dual-label immunofluorescence in conjunction with confocal microscopy. The Cx43 staining analyzed by high-resolution confocal microscopy appeared as continuous, anastomozed ribbons and thin dots. The level of Cx43 immunoreactivity was reduced in seminiferous tubules of ebo/ebo and jun-d-/- mutants as compared to the respective wild-type mice. No staining for Cx43 was detected in Sertoli cell-only seminiferous tubules observed sometimes in jun-d-/- mice. The present study represents one of the first in vivo examples of alteration of seminiferous tubule Cx43 in testes with impaired spermatogenesis.

Regulation of tissue-type plasminogen activator and its inhibitor (PAI-1) by lipopolysaccharide-induced phagocytosis in a Sertoli cell line

The plasminogen activator (PA) system is thought to play a major role in the proteolytic events associated with spermatogenesis. The mechanisms controlling the expression of PA and of its major physiological inhibitor, plasminogen activator inhibitor type-1 (PAI-1), in the seminiferous epithelium are still unknown. In the present study we analyzed the expression of PA and PAI-1 in a murine Sertoli cell line (42GPA9) in response to stimulation by lipopolysaccharides (LPS) used to activate the phagocytic activity of these cells. Immortalized Sertoli cells cultured under basal conditions secreted predominantly tissue-type PA (tPA) as demonstrated by zymographic analysis and the presence of tPA transcripts. In zymographic experiments a larger molecular weight proteolytic band corresponding to the formation of PA-PAI-1 complex was also observed. The stimulation of immortalized Sertoli cells by LPS resulted in both alteration of the apparent tPA molecular weight to a higher form and transient increase in PAI-1 biosynthesis. The phorbol ester TPA stimulates similarly PAI-1 synthesis in the Sertoli cell line, while 8-bromo-cAMP has no effect. These results suggest for the first time the existence of a direct linkage between molecular events triggered by phagocytosis and regulation of tPA and PAI-1 in Sertoli cells.

Ultrastructural and biochemical evidence for gap junction and connexin 43 expression in a clonal Sertoli cell line: a potential model in the study of junctional complex formation

To clarify the exact role of Sertoli cells in testicular intercellular communications, a murine Sertoli cell line (42GPA9) has recently been established. Electron-microscopy studies indicate that the morphology of these immortalized cells strongly resembles that of mouse Sertoli cells in vivo with an indentend nucleus, elongated mitochondria and numerous lysosome-like structures. Ultrastructure analysis has also revealed that 42GPA9 cells form gap junctions as demonstrated by the presence of small electron-dense bridges that connect the plasma membranes of adjacent cells. The gap junction protein connexin 43 (Cx43) has been identified in cultured 42GPA9 cells by immunofluorescence and Western blot analysis. No immunostaining is detected in the absence of apparent intercellular contact. The anti-Cx43 antibody labels the contacts between 42GPA9 cells at confluency. This specific staining appears as small dots forming isolated rows of dots or surrounding the entire cell, suggesting that Cx43 is assembled into membrane plaques. The gap junctional communication capacity of the 42GPA9 cell line has been demonstrated by the dye-transfer technique. Exposure of 42GPA9 cells for 24 h to cAMP and 12-O-tetradecanoylphorbol-13-acetate greatly reduces the Cx43 staining at cell-cell contacts and concomitantly increases the cytoplasmic staining, suggesting that these agents alter the trafficking of Cx43 to the plasma membrane. Thus, the 42GPA9 line may provide a useful in vitro model for studying gap junction communication between Sertoli cells.

[Late recurrence of subacute De Quervain-Crile thyroiditis]

Subacute thyroiditis usually recovers completely, and recurrences are unfrequent. We report hereafter the case of a 70-year-old man with a typical diagnosis of subacute thyroiditis. He reported a similar episode 20 years earlier, followed by a mild but persistant hypothyroidism. This case reminds that recurrence of subacute thyroiditis can occur even after many years.

Protein tyrosine phosphorylation is associated with capacitation of human sperm in vitro but is not sufficient for its completion

Capacitation is a prerequisite step that mammalian sperm must take before being able to undergo the acrosome reaction (AR). The molecular mechanisms of this process remain incompletely understood and can be studied only in vitro. Human sperm preparation for insemination of oocytes requires the removal of seminal plasma and incubation in defined media that usually contain albumin and calcium. In various conditions of capacitation, we have studied the relationship between protein tyrosine phosphorylation as measured by Western blotting and the capacitation state as evaluated by ionomycin-induced AR in the presence of calcium. Several proteins with molecular masses from 60 to 200 kDa became increasingly phosphorylated with time. The kinetics of phosphorylation showed an inter-individual variability, with a maximal level reached between 1 and 4 h, and was associated with the capacitation state. Albumin increased phosphorylation in a concentration-dependent manner. Lack of albumin prevented both phosphorylation and capacitation. Conversely, lack of CaCl2 in the capacitating medium enhanced phosphorylation and did not impair the induced AR. Surprisingly, sperm incubation in seminal plasma, which is supposed to contain "decapacitation factors," did not affect the time-dependent increase in tyrosine phosphorylation. However, in seminal plasma-free medium, it inhibited induction of the AR. Protein tyrosine phosphorylation is associated with in vitro capacitation. Although it cannot by itself complete capacitation, it could represent an important step in this process by priming the transductive pathways that are activated during exocytosis.

Characterisation and role of integrins during gametic interaction and egg activation

It has recently been proposed that some of the processes induced by fertilisation in mammals may be mediated by integrins. By performing immunofluorescence labelling and Western blots with antibodies directed against some of the alpha and beta subunits of integrins, we show here the presence of some of these proteins in human and hamster oocytes. Among them, alpha 2 and alpha 5 were also present on in vitro preparations of sea urchin egg cortices. In addition, antibodies raised against these two proteins were the most effective at inhibiting attachment and fusion of human spermatozoa with hamster oocytes. We suggest that alpha 2 and alpha 5 integrin chains may be common mediators in adhesion-fusion mechanisms triggered by fertilisation. Using similar techniques, we show that eggs are rich in three cytoskeletal proteins known to be linked to the beta chain of integrins: talin, vinculin and alpha-actinin. Moreover, we found that talin and alpha-actinin were associated with proteins phosphorylated on tyrosine after fertilisation in sea urchin eggs. We suggest that integrins might be involved during fertilisation and trigger egg activation through cytoskeletal structures.

Expression of complement regulatory proteins on human eggs and preimplantation embryos

PROBLEM

To investigate the relation between the complement system and reproduction, expression of complement regulatory proteins (C3b receptors and inhibitor of the membrane attack complex) were screened on unfixed human eggs and preimplantation embryos.

METHODS

Unfixed unfertilized oocytes and preimplantation embryos obtained from an in vitro fertilization program were stained by indirect immunofluorescence using monoclonal antibodies raised against membrane cofactor protein, (MCP or CD46), decay accelerating factor (DAF or CD55), protectin (CD59), human C3b/C4b receptor (CR1 or CD35), and major histocompatibility complex class I antigen (MHC class I).

RESULTS

CD55 and CD59 were both expressed by the plasma membrane of unfertilized oocytes and pre-implantation embryos. CD46 was not expressed by unfertilized oocytes but appeared at the 6-to-8 cell stage embryo when human gene expression first occurs. CD35 and MHC class I antigens were not expressed at all on oocytes and preimplantation embryos.

CONCLUSIONS

Selective expression of complement regulatory proteins (DAF and protectin) associated with the lack of MHC class I antigens may represent an immune protective mechanism by which human oocytes and preimplantation embryos escape complement-mediated damage during their travel through the female genital tract. Furthermore, participation of these complement regulatory proteins including MCP in cell to cell interaction during fertilization and/or implantation cannot be excluded.

Expression of the complement regulatory protein CD59 on human spermatozoa: characterization and role in gametic interaction

Protectin (CD59) is a complement regulatory protein which blocks the membrane attack complex during complement activation. CD59 was identified on the human sperm surface by means of H19, an IgG1 anti-protectin mouse monoclonal antibody. Using indirect immunofluorescence, flow cytometry and immunoperoxidase, CD59 was found to be present on the whole plasma membrane including the head and tail of fresh ejaculated, capacitated and acrosome-reacted spermatozoa. Immunoperoxidase staining of normal testicular sections indicated that this protein was already present on intraluminal germ cells. Analysis of this sperm protein by gel electrophoresis and immunoblotting revealed that its molecular weight of 20 kDa was comparable to that of CD59 expressed on peripheral blood cells (erythrocytes, lymphocytes) and that it was bound to the membrane through a glycophospholipid tail which could be released after treatment with phosphatidylinositol-specific phospholipase C. Associated to membrane cofactor protein (CD46) and decay accelerating factor (CD55) located in the acrosomal membranes, CD59 may participate to the protection of male gametes against complement-mediated damage as they travel through the female genital tract. Moreover CD59, known as an adhesion molecule involved in lymphocyte rosettes, may also participate in cell to cell adhesion during gametic interaction since H19 inhibited sperm binding and reduced the penetration rate and index during the hamster egg penetration test.

High expression of the antigen recognized by the monoclonal antibody GB24 on human breast carcinomas: a preventive mechanism of malignant tumor cells against complement attack?

GB24 is a mouse monoclonal antibody raised against a common trophoblast-lymphocyte cross-reactive antigen. GB24 detects the membrane cofactor protein (MCP, CD46), a member of the complement regulatory protein family, which serves as a cofactor for factor 1 mediated cleavage of C3b. This study investigated the reactivity of GB24 on 38 breast carcinomas and 34 normal/benign breast tissues by immunochemistry as well as the reactivity of F2B7-2, an antibody specific to the decay accelerating factor (DAF, CD55) of the complement. GB24 staining was present on both normal tissue and benign lesions, but very strong diffuse reactivity was observed on carcinomas. This reactivity increased with the tumor grade. By contrast, malignant tumor cells lacked DAF expression. F2B7-2 antibody reacted weakly with benign epithelial cells. Results were studied by computer assisted image analysis to accurately define the mean optical densities. The densitometric analysis of MCP positive carcinomas showed a high intensity of the staining. Expression of MCP and DAF on MCF-7 cell lines was analyzed by flow cytometry. MCF-7 cell lines were strongly stained by mAb GB24 only. These data suggest that selectively enhanced expression of the antigen recognized by GB24 is associated with malignant breast disorders. This high expression, which may reflect a protective mechanism by which tumor cells survive complement activation, may prove useful as a marker of malignant transformation.