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Objective: The French Law relating to Bioethics allows access to medically assisted reproduction for lesbian couples and single women and has expanded the possibilities for self-preservation of gametes. The question now arises of new uses of gametes of the couple, within couples of two cis women, one cis woman and one transgender woman, or two transgender individuals. The acronym EUGIC (Extension of the Use of Gametes in IntraCouple) allows these new situations to be grouped together, particularly if gametes have already been previously cryopreserved, thus avoiding the need for gamete donation., Methods: Analysis of the different situations of sperm use from a trans woman using gametes available within the couple rather than gamete donation., Results: The inconsistency in the use of sperm from a trans woman, the situations already encountered by professionals, the prospects for filiation for a trans woman as well as the issues related to the interest of the unborn child are discussed., Conclusion: French law does not fully address the use of a trans woman's spermatozoa to meet the new EUGIC requirements and leads to complex situations for healthcare professionals., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Objective: New possibilities for using gametes within a couple were created by the French law of August 2, 2021 related to bioethics by opening Assisted Reproductive Technics (ART) to all women. It concerns previously self-preserved gametes, thus avoiding the need for gamete donation. The objective of our study is to evaluate the perception of these new uses by ART practitioners., Method: A questionnaire of twelve short questions was sent to professionals concerned with gamete donation., Results: One hundred and ten professionals answered the questionnaire. The majority of them approve of the Reception of Oocytes from the Partner (ROPA), notably if there is a medical indication. Requests are rarer for the care of trans* people, and raise more questions. Although less favorable to the use of eggs from trans* men, more of them support the practice when it is an alternative to oocyte donation., Conclusion: The acronym EUGIC (Extension of the Use of Gametes in Intra-Conjugal) makes it possible to group together these new situations generated by the change in the French law., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)

Advancements in tracking technologies provide an increasingly important tool in animal monitoring and conservation that can describe animal spatial behavior in native habitats and uncover migratory routes that otherwise may be difficult or impossible to map. In addition, high-resolution accelerometer sensors provide powerful insights into animal activity patterns and can help to identify specific behaviors from accelerometer profiles alone. Previously, such accelerometers were restricted to larger animals due to size and mass constraints. However, recent advances make it possible to use such devices on smaller animals such as the European green toad ( Bufotes viridis ), the focus of our current study. We deploy custom made tracking devices, that consist of very-high-frequency transmitters and tri-axial accelerometers, to track toads in their native urban environment in Vienna (Austria). A total of nine toads were tracked, ranging from three to nine tracking days per individual during the post-breeding season period. We demonstrate that our devices could reliably monitor toad movement and activity during the observation period. Hence, we confirmed the predominantly nocturnal activity patterns and recorded low overall movement at this urban site. Accelerometer data revealed that toads exhibited brief but intense activity bursts between 10 pm and midnight, resting periods during the night and intermittent activity during the day. Positional tracking alone would have missed the major activity events as they rarely resulted in large positional displacements. This underscores the importance of and value in integrating multiple tracking sensors for studies of movement ecology. Our approach could be adapted for other amphibians or other animals with mass constraints and may become standard monitoring equipment in the near future., Competing Interests: Conflicts of Interest: The authors declare no conflict of interest.

Serotonin (5-hydroxytryptamine, 5-HT) is a biogenic monoamine acting as a neurotransmitter in the central nervous system (CNS), local mediator in the gut, and vasoactive agent in the blood. It has been linked to a variety of CNS functions and is implicated in many CNS and psychiatric disorders. The high comorbidity between some neuropathies can be partially understood by the fact that these diseases share a common etiology involving the serotoninergic system. In addition to its well-known functions, serotonin has been shown to be a mitogenic factor for a wide range of normal and tumor cells, including glioma cells, in vitro. The developing CNS of fetus and newborn is particularly susceptible to the deleterious effects of neurotoxic substances in our environment, and perinatal exposure could result in the later development of diseases, a hypothesis known as the developmental origin of health and disease. Some of these substances affect the serotoninergic system and could therefore be the source of a silent pandemic of neurodevelopmental toxicity. This review presents the available data that are contributing to the appreciation of the effects of the exposome on the serotoninergic system and their potential link with brain pathologies (neurodevelopmental, neurodegenerative, neurobehavioral disorders, and glioblastoma).

The incidence of brain pathologies has increased during last decades. Better diagnosis (autism spectrum disorders) and longer life expectancy (Parkinson's disease, Alzheimer's disease) partly explain this increase, while emerging data suggest pollutant exposures as a possible but still underestimated cause of major brain disorders. Taking into account that the brain parenchyma is rich in gap junctions and that most pollutants inhibit their function; brain disorders might be the consequence of gap-junctional alterations due to long-term exposures to pollutants. In this article, this hypothesis is addressed through three complementary aspects: (1) the gap-junctional organization and connexin expression in brain parenchyma and their function; (2) the effect of major pollutants (pesticides, bisphenol A, phthalates, heavy metals, airborne particles, etc.) on gap-junctional and connexin functions; (3) a description of the major brain disorders categorized as neurodevelopmental (autism spectrum disorders, attention deficit hyperactivity disorders, epilepsy), neurobehavioral (migraines, major depressive disorders), neurodegenerative (Parkinson's and Alzheimer's diseases) and cancers (glioma), in which both connexin dysfunction and pollutant involvement have been described. Based on these different aspects, the possible involvement of pollutant-inhibited gap junctions in brain disorders is discussed for prenatal and postnatal exposures.

The resistance of glioblastomas to treatments is mainly the consequence of their invasive capacities. Therefore, in order to better treat these tumors, it is important to understand the molecular mechanisms which are responsible for this behavior. Previous work suggested that gap junction proteins, the connexins, facilitate the aggressive nature of glioma cells. Here, we show that one of them-connexin43 (Cx43)-is implicated in the formation and function of invadopodia responsible for invasion capacity of U251 human glioblastoma cells. Immunofluorescent approaches-combined with confocal analyses-revealed that Cx43 was detected in all the formation stages of invadopodia exhibiting proteolytic activity. Clearly, Cx43 appeared to be localized in invadopodia at low cell density and less associated with the establishment of gap junctions. Accordingly, lower extracellular matrix degradation correlated with less mature invadopodia and MMP2 activity when Cx43 expression was decreased by shRNA strategies. Moreover, the kinetics of invadopodia formation could be dependent on Cx43 dynamic interactions with partners including Src and cortactin. Interestingly, it also appeared that invadopodia formation and MMP2 activity are dependent on Cx43 hemichannel activity. In conclusion, these results reveal that Cx43 might be involved in the formation and function of the invadopodia of U251 glioblastoma cells.

Tissue homeostasis is the result of a complex intercellular network controlling the behavior of every cell for the survival of the whole organism. In mammalian tissues, cells do communicate via diverse long- and short-range communication mechanisms. While long-range communication involves hormones through blood circulation and neural transmission, short-range communication mechanisms include either paracrine diffusible factors or direct interactions (e.g., gap junctions, intercellular bridges and tunneling nanotubes) or a mixture of both (e.g., exosomes). Tumor growth represents an alteration of tissue homeostasis and could be the consequence of intercellular network disruption. In this network, direct short-range intercellular communication seems to be particularly involved. The first type of these intercellular communications thought to be involved in cancer progression were gap junctions and their protein subunits, the connexins. From these studies came the general assumption that global decreased connexin expression is correlated to tumor progression and increased cell proliferation. However, this assumption appeared more complicated by the fact that connexins may act also as pro-tumorigenic. Then, the concept that direct intercellular communication could be involved in cancer has been expanded to include new forms of intercellular communication such as tunneling nanotubes (TNTs) and exosomes. TNTs are intercellular bridges that allow free exchange of small molecules or even mitochondria depending on the presence of gap junctions. The majority of current research shows that such exchanges promote cancer progression by increasing resistance to hypoxia and chemotherapy. If exosomes are also involved in these mechanisms, more studies are needed to understand their precise role. Prostate cancer (PCa) represents a type of malignancy with one of the highest incidence rates worldwide. The precise role of these types of direct short-range intercellular communication has been considered in the progression of PCa. However, even though data are in favor of connexins playing a key role in PCa progression, a clear understanding of the role of TNTs and exosomes is needed to define their precise role in this malignancy. This review article summarizes the current view of the main mechanisms involved in short-range intercellular communication and their implications in cancer and delves into the biological, predictive and therapeutic role of connexins in PCa.

Gap junctions comprise arrays of intercellular channels formed by connexin proteins and provide for the direct communication between adjacent cells. This type of intercellular communication permits the coordination of cellular activities and plays key roles in the control of cell growth and differentiation and in the maintenance of tissue homoeostasis. After more than 50 years, deciphering the links among connexins, gap junctions and cancer, researchers are now beginning to translate this knowledge to the clinic. The emergence of new strategies for connexin targeting, combined with an improved understanding of the molecular bases underlying the dysregulation of connexins during cancer development, offers novel opportunities for clinical applications. However, different connexin isoforms have diverse channel-dependent and -independent functions that are tissue and stage specific. This can elicit both pro- and anti-tumorigenic effects that engender significant challenges in the path towards personalised medicine. Here, we review the current understanding of the role of connexins and gap junctions in cancer, with particular focus on the recent progress made in determining their prognostic and therapeutic potential.

Besides its classical functions as a neurotransmitter in the central nervous system, local mediator in the gastrointestinal tract and vasoactive agent in the blood, serotonin has more recently emerged as a growth factor for human tumor cells of different origins (carcinomas, glioma and carcinoids). Several data are also available on serotonin involvement in cancer cell migration, metastatic dissemination and tumor angiogenesis. The serotonin-induced signaling pathways that promote tumor progression are complex and only partly understood in some cancer types. The results of several studies showed that serotonin levels in the tumor played a crucial role in cancer progression. A serotonin production and secretion by neuroendocrine cells have been shown in the progression of several solid tumors and the involvement of a serotoninergic autocrine loop was proposed. Specific receptor subtypes are associated with different fundamental stages of tumor progression and the pattern of receptors expression becomes dysregulated in several human tumors when compared with normal cells or tissues. Serotonin receptors, selective serotonin transporter and serotonin synthesis pathways are potential chemotherapeutic targets for the treatment of several cancers in which therapeutic approaches are limited. Through several asked questions, this critical mini-review discusses the relevance of the involvement of serotonin in human cancer progression., (Copyright © 2018 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.)

Extracellular matrix (ECM) remodeling, degradation and glioma cell motility are critical aspects of glioblastoma multiforme (GBM). Despite being a rich source of potential biomarkers and targets for therapeutic advance, the dynamic changes occurring within the extracellular environment that are specific to GBM motility have yet to be fully resolved. The gap junction protein connexin43 (Cx43) increases glioma migration and invasion in a variety of in vitro and in vivo models. In this study, the upregulation of Cx43 in C6 glioma cells induced morphological changes and the secretion of proteins associated with cell motility. Demonstrating the selective engagement of ECM remodeling networks, secretome analysis revealed the near-binary increase of osteopontin and matrix metalloproteinase-3 (MMP3), with gelatinase and NFF-3 assays confirming the proteolytic activities. Informatic analysis of interactome and secretome downstream of Cx43 identifies networks of glioma motility that appear to be synergistically engaged. The data presented here implicate ECM remodeling and matrikine signals downstream of Cx43/MMP3/osteopontin and ARK1B10 inhibition as possible avenues to inhibit GBM.

Background: Major depressive disorder (MDD) is a multifactorial chronic and debilitating mood disease with high lifetime prevalence and associated with excess mortality. Treatments for this disease are not effective in all patients showing the need to find new therapeutic targets., Objective: This review aims to update our knowledge on the involvement of astroglial gap junctions and hemichannels in MDD and to show how they have become potential targets for the treatment of this pathology., Methods: The method applied in this review includes a systematic compilation of the relevant literature., Results and Conclusion: The use of rodent models of depression, gene analysis of hippocampal tissues of MDD patients and post-mortem studies on the brains from MDD patients suggest that astrocytic gap junction dysfunction may be a part of MDD etiologies. Chronic antidepressant treatments of rats, rat cultured cortical astrocytes and human astrocytoma cell lines support the hypothesis that the up-regulation of gap junctional coupling between astrocytes could be an underlying mechanism for the therapeutic effect of antidepressants. However, two recent functional studies suggest that connexin43 hemichannel activity is a part of several antidepressants' mode of action and that astrocyte gap junctional intercellular communication and hemichannels exert different effects on antidepressant drug response. Even if they emerge as new therapeutic targets for new and more active treatments, further studies are needed to decipher the sophisticated and respective role of astrocytic gap junctions and hemichannels in MDD., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Objective: Using non-invasive magnetic resonance (MR) techniques and a histological approach, we assessed the outcomes of perinatal exposure at a low dose of 3,3'-DCBPA (2-chloro-4-[1-(3-chloro-4-hydroxyphenyl)-1-methylethyl]phenol) and/or 3,5-DCBPA (2,6-dichloro-4-[1-(4-hydroxyphenyl)-1-methylethyl]phenol) on mice livers., Materials and Methods: Fertilized female Swiss mice were injected intraperitoneally during gestation and lactation with either vehicle control, 20 μg/kg/day of BPA, 3,5-DCBPA, 3,3'-DCBPA or a mixture (mix-DCBPA). Complementary methods were used to evaluate, in male and female pups, (1) liver structure by texture analysis of images obtained through MR imaging (MRI) and histology, (2) hepatic lipid composition through in vivo 1 H MR spectroscopy ( 1 H MRS)., Results: Principal component analysis of texture parameters showed no structural modification of the liver with BPA and DCBPA treatments. Accordingly, no hepatic microvesicular steatosis was observed through hematoxylin-eosin staining. Compared to control, MRS revealed no difference in lipid composition for BPA, 3,5-DCBPA or 3,3'-DCBPA groups. However, MRS detected a significant increase in the mix-DCBPA groups for the saturated component of fatty acids (FA), total unsaturated FA bond index and polyunsaturated FA bond index., Conclusion: Prior to any structural changes, polyunsaturated fatty acids significantly increased in young male and female mice exposed perinatally at a low dose to a mixture of dichlorinated BPA.

Since their characterization more than five decades ago, gap junctions and their structural proteins-the connexins-have been associated with cancer cell growth. During that period, the accumulation of data and molecular knowledge about this association revealed an apparent contradictory relationship between them and cancer. It appeared that if gap junctions or connexins can down regulate cancer cell growth they can be also implied in the migration, invasion and metastatic dissemination of cancer cells. Interestingly, in all these situations, connexins seem to be involved through various mechanisms in which they can act either as gap-junctional intercellular communication mediators, modulators of signalling pathways through their interactome, or as hemichannels, which mediate autocrine/paracrine communication. This complex involvement of connexins in cancer progression is even more complicated by the fact that their hemichannel function may overlap with other gap junction-related proteins, the pannexins. Despite this complexity, the possible involvements of connexins and pannexins in cancer progression and the elucidation of the mechanisms they control may lead to use them as new targets to control cancer progression. In this review, the involvements of connexins and pannexins in these different topics (cancer cell growth, invasion/metastasis process, possible cancer therapeutic targets) are discussed.

The molecular mechanisms governing the formation of lymphatic vasculature are not yet well understood. Pannexins are transmembrane proteins that form channels which allow for diffusion of ions and small molecules (<1 kDa) between the extracellular space and the cytosol. The expression and function of pannexins in blood vessels have been studied in the last few decades. Meanwhile, no studies have been conducted to evaluate the role of pannexins during human lymphatic vessel formation. Here we show, using primary human dermal lymphatic endothelial cells (HDLECs), pharmacological tools (probenecid, Brilliant Blue FCF, mimetic peptides [ 10 Panx]) and siRNA-mediated knockdown that Pannexin-1 is necessary for capillary tube formation on Matrigel and for VEGF-C-induced invasion. These results newly identify Pannexin-1 as a protein highly expressed in HDLECs and its requirement during in vitro lymphangiogenesis.

This article is a report of the "International Colloquium on Gap junctions: 50Years of Impact on Cancer" that was held 8-9 September 2016, at the Amphitheater "Pôle Biologie Santé" of the University of Poitiers (Poitiers, France). The colloquium was organized by M Mesnil (Université de Poitiers, Poitiers, France) and C Naus (University of British Columbia, Vancouver, Canada) to celebrate the 50th anniversary of the seminal work published in 1966 by Loewenstein and Kanno [Intercellular communication and the control of tissue growth: lack of communication between cancer cells, Nature, 116 (1966) 1248-1249] which initiated studies on the involvement of gap junctions in carcinogenesis. During the colloquium, 15 participants presented reviews or research updates in the field which are summarized below., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Over the past 50years, increasing experimental evidences have established that connexins (Cxs) and gap junctional intercellular communication (GJIC) ensure an important role in both the onset and development of cancerous processes. In the present review, we focus on the impact of Cxs and GJIC during the development of prostate cancer (PCa), from the primary growth mainly localized in acinar glands and ducts to the distant metastasis mainly concentrated in bone. As observed in several other types of solid tumours, Cxs and especially Cx43 exhibit an ambivalent role with a tumour suppressor effect in the early stages and, conversely, a rather pro-tumoural profile for most of invasion and dissemination steps to secondary sites. We report here the current knowledge on the function of Cxs during PCa cells migration, cytoskeletal dynamics, proteinases activities and the cross talk with the surrounding stromal cells in the microenvironment of the tumour and the bones. In addition, we discuss the role of Cxs in the bone tropism even if the prostate model is rarely used to study the complete sequence of cancer dissemination compared to breast cancer or melanoma. Even if not yet fully understood, these recent findings on Cxs provide new insights into their molecular mechanisms associated with progression and bone targeted behaviour of PCa. This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Connexins are chordate gap junction channel proteins that, by enabling direct communication between the cytosols of adjacent cells, create a unique cell signalling network. Gap junctional intercellular communication (GJIC) has important roles in controlling cell growth and differentiation and in tissue development and homeostasis. Moreover, several non-canonical connexin functions unrelated to GJIC have been discovered. Of the 21 members of the human connexin family, connexin 43 (Cx43) is the most widely expressed and studied. The long cytosolic C-terminus (CT) of Cx43 is subject to extensive post-translational modifications that modulate its intracellular trafficking and gap junction channel gating. Moreover, the Cx43 CT contains multiple domains involved in protein interactions that permit crosstalk between Cx43 and cytoskeletal and regulatory proteins. These domains endow Cx43 with the capacity to affect cell growth and differentiation independently of GJIC. Here, we review the current understanding of the regulation and unique functions of the Cx43 CT, both as an essential component of full-length Cx43 and as an independent signalling hub. We highlight the complex regulatory and signalling networks controlled by the Cx43 CT, including the extensive protein interactome that underlies both gap junction channel-dependent and -independent functions. We discuss these data in relation to the recent discovery of the direct translation of specific truncated forms of Cx43. This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Connexins (Cx) are largely represented in the central nervous system (CNS) with 11 Cx isoforms forming intercellular channels. Moreover, in the CNS, Cx43 can form hemichannels (HCs) at non-junctional membrane as does the related channel-forming Pannexin1 (Panx1) and Panx2. Opening of Panx1 channels and Cx43 HCs appears to be involved in inflammation and has been documented in various CNS pathologies. Over recent years, evidence has accumulated supporting a link between inflammation and cerebral neuropathies (migraine, Alzheimer's disease (AD), Parkinson's disease (PD), major depressive disorder, autism spectrum disorder (ASD), epilepsy, schizophrenia, bipolar disorder). Involvement of Panx channels and Cx43 HCs has been also proposed in pathophysiology of neurological diseases and psychiatric disorders. Other studies showed that following inflammatory injury of the CNS, Panx1 activators are released and prolonged opening of Panx1 channels triggers neuronal death. In neuropsychiatric diseases, comorbidities are frequently present and can aggravate the symptoms and make therapeutic management more complex. The high comorbidity between some neuropathies can be partially understood by the fact that these diseases share a common etiology involving inflammatory pathways and Panx1 channels or Cx43 HCs. Thus, anti-inflammatory therapy opens perspectives of targets for new treatments and could have real potential in controlling a cerebral neuropathy and some of its comorbidities. The purpose of this mini review is to provide information of our knowledge on the link between Cx43- and Panx-based channels, inflammation and cerebral neuropathies.

Fifty years ago, tumour cells were found to lack electrical coupling, leading to the hypothesis that loss of direct intercellular communication is commonly associated with cancer onset and progression. Subsequent studies linked this phenomenon to gap junctions composed of connexin proteins. Although many studies support the notion that connexins are tumour suppressors, recent evidence suggests that, in some tumour types, they may facilitate specific stages of tumour progression through both junctional and non-junctional signalling pathways. This Timeline article highlights the milestones connecting gap junctions to cancer, and underscores important unanswered questions, controversies and therapeutic opportunities in the field.

Antimicrobial peptides can be used as therapeutic agents against cancer cells. Warnericin RK and derivatives (WarnG20D and WarnF14V) were tested on various, solid tumor or leukemia, cancer cells. These peptides appeared to be cytotoxic on all the cell types tested, cancerous as well healthy, but very interestingly displayed no deleterious effect on healthy mononuclear cells. The mode of action of the peptide was proposed to be membranolytic, using chemical Raman imaging. Addition of peptide induced a large disorganization of the membrane leading to the loss of the content of inner compartments of Jurkat cell, whereas no effect was observed on the healthy mononuclear cells. The less hemolytic peptides WarnG20D and WarnF14V could be good candidates for the leukemia treatment., Competing Interests: The authors have declared that no competing interests exist.

Precise diagnosis of low and high grades of brain tumors permits determining therapeutical strategies. So far, diagnosis and prognosis of gliomas were based on histological and genetic criteria which need being completed by a panel of molecular markers. Highly distributed in brain, gap junction proteins, connexins, could be considered as markers of glioma progression as previous studies indicated that expression of a connexin type, connexin43 (Cx43), is inversely correlated to tumor grading. However, this assumption was weakened by the low number of glioma samples used. Taking advantage of tissue microarray technique, we pursued this analysis by studying in situ expression of Cx43 on 85 samples (37 grade IV, 18 grade III, 24 grade II, and 6 grades II to III). Our analysis confirmed the global diminution of Cx43 expression in glioblastomas that was observed in previous studies. However, this analysis brought new insights such as the following ones. First, the high number of samples permitted to show that more than 60% of glioblastomas still express Cx43. Second, no gradual decrease in Cx43 expression was observed between grades II and III, but Cx43 appeared to be a marker distinguishing oligodendrocytic and astrocytic grade III tumors. Third, independently from tumor grade, a Cx43 nuclear staining was detected in areas where leukocytes are present. In conclusion, our study emphasizes the importance of in situ immunohistochemical approaches by giving more precise insights in the subcellular localization of Cx43. It also emphasizes the necessity to carry out such analysis on a wide range of samples to circumvent the high glioma heterogeneity., (© 2016 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

Several cultivars of peach fruit (Prunus persica L.) were investigated. Their phenolic composition and concentration were assessed by LC-MS. Concentrations were calculated in mg per g of dry weight extract. Their antioxidant capacity (Folin-Ciocalteu, ORAC, DPPH, ABTS, PFRAP and ICA), inhibitory property against β-amyloid and α-synuclein fibril formation and protective capacity against Aβ-induced toxicity on PC12 cell lines (viability assessed by MTT assay and intracellular ROS production by DCFH-DA assay) were evaluated. Fifteen different phenolic compounds were identified and quantified. In particular, new isorhamnetin derivatives were identified. Phenolic contents were ranged between 19 and 82mg/g. Spring Belle extract had the highest content and Romea the lowest. Except for the ICA assay, a good correlation between phenolic content and the antioxidant capacities of peach fruit extracts was found, indicating that phenolic compounds are major contributors to their antioxidant capacity. Results indicate that the phenolic extract of peach cultivars inhibits Aβ and αS fibril formation and protects PC12 cell lines against Aβ-induced toxicity., (Copyright © 2016. Published by Elsevier Ltd.)

Optic neuritis could lead to severe visual impairment despite corticosteroids. Our aim was to evaluate the rate of visual improvement in patients treated with plasma exchange (PLEX) for severe steroid unresponsive optic neuritis and to identify predictive factors of outcome. Thirty-four patients (41 optic nerves damaged) with remaining visual acuity of 0.1 or less despite steroid pulse therapy were treated with PLEX from September 2010 to May 2015. Demographic and clinical neuro-ophthalmic findings, and spectral domain-optical coherence tomography data before PLEX treatment were analyzed. The mean symptom duration before PLEX was 34.6 days (median 28 days; range 6-92 days). After PLEX, the median final visual acuity was 0.8 and in 56 % of cases, final acuity was 0.5 or better. Past history of ipsilateral optic neuritis was associated significantly with poor outcome defined as final acuity less than 0.5. No significant difference in the visual outcome after PLEX was found between multiple sclerosis and neuromyelitis optica. In conclusion, this observational study showed that PLEX as second-line therapy led to a functionally important visual recovery in more than half patients with severe optic neuritis.

The connexins constitute a family of integral membrane proteins that form channels between adjacent cells. These channels are assembled in plasma membrane domains known as gap junctions and enable cells to directly exchange ions and small molecules. Intercellular communication via gap junctions plays important roles in regulating cell growth and differentiation and in maintaining tissue homeostasis. This type of cell communication is often impaired during cancer development, and several members of the connexin protein family have been shown to act as tumor suppressors. Emerging evidence suggests that the connexin protein family has important roles in colorectal cancer development. In the normal colonic epithelial tissue, three connexin isoforms, connexin 26 (Cx26), Cx32 and Cx43, have been shown to be expressed at the protein level. Colorectal cancer development is associated with loss of connexin expression or relocalization of connexins from the plasma membrane to intracellular compartments. Downregulation of connexins in colorectal carcinomas at the transcriptional level involves cancer-specific promoter hypermethylation. Recent studies suggest that Cx43 may constrain growth of colon cancer cells by interfering with the Wnt/β-catenin pathway. There is also increasing evidence that the connexins may have potential as prognostic markers in colorectal cancer. This review discusses the role of connexins in colorectal cancer pathogenesis, as well as their potential as prognostic markers and targets in the prevention and treatment of the disease., (© 2014 UICC.)

Serotonin (5-hydroxytryptamine, 5-HT) is a biogenic monoamine that acts as a neurotransmitter in the central nervous system, local mediator in the gut and vasoactive agent in the blood. Serotonin exerts its multiple, sometimes opposing actions through interaction with a multiplicity of receptors coupled to various signalling pathways. In addition to its well-known functions, serotonin has been shown to be a mitogenic factor for a wide range of normal and tumoral cells. Serotonin exhibits a growth stimulatory effect in aggressive cancers and carcinoids more often through 5- HT1 and 5-HT2 receptors. In contrast, low doses of serotonin can inhibit tumour growth via the decrease of blood supply to the tumour, suggesting that the role of serotonin on tumour growth is concentration-dependent. Data are also available on serotonin involvement in cancer cell migration, metastatic processes and as a mediator of angiogenesis. Moreover, the progression of some tumours is accompanied by a dysregulation of the pattern of serotonin receptor expressions. Serum serotonin level was found to be suitable for prognosis evaluation of urothelial carcinoma in the urinary bladder, adenocarcinoma of the prostate and renal cell carcinoma. In some cases, antagonists of serotonin receptors, inhibitors of selective serotonin transporter and of serotonin synthesis have been successfully used to prevent cancer cell growth. This review revaluates serotonin involvement in several types of cancer and at different stages of their progression.

Formation of metastases negatively impacts the survival prognosis of cancer patients. Globally, if the various steps involved in their formation are relatively well identified, the molecular mechanisms responsible for the emergence of invasive cancer cells are still incompletely resolved. Elucidating what are the mechanisms that allow cancer cells to evade from the tumor is a crucial point since it is the first step of the metastatic potential of a solid tumor. In order to be invasive, cancer cells have to undergo transformations such as down-regulation of cell-cell adhesions, modification of cell-matrix adhesions and acquisition of proteolytic properties. These transformations are accompanied by the capacity to "activate" stromal cells, which may favor the motility of the invasive cells through the extracellular matrix. Since modulation of gap junctional intercellular communication is known to be involved in cancer, we were interested to consider whether these different transformations necessary for the acquisition of invasive phenotype are related with gap junctions and their structural proteins, the connexins. In this review, emerging roles of connexins and gap junctions in the process of tissue invasion are proposed., (Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.)

Migraine is a common, recurrent, and disabling primary headache disorder with a genetic component which affects up to 20% of the population. One third of all patients with migraine experiences aura, a focal neurological disturbance that manifests itself as visual, sensitive or motor symptoms preceding the headache. In the pathophysiology of migraine with aura, activation of the trigeminovascular system from the meningeal vessels mediates migraine pain via the brainstem and projections ascend to the thalamus and cortex. Cortical spreading depression (CSD) was proposed to trigger migraine aura and to activate perivascular trigeminal nerves in the cortex. Quinine, quinidine and the derivative mefloquine are able to inhibit CSD suggesting an involvement of neuronal connexin36 channels in CSD propagation. More recently, CSD was shown to induce headache by activating the trigeminovascular system through the opening of stressed neuronal Pannexin1 channels. A novel benzopyran compound, tonabersat, was selected for clinical trial on the basis of its inhibitory activity on CSD and neurogenic inflammation in animal models of migraine. Interestingly, in the time course of animal model trials, tonabersat was shown to inhibit trigeminal ganglion (TGG) neuronal-glial cell gap junctions, suggesting that this compound could prevent peripheral sensitization within the ganglion. Three clinical trials aimed at investigating the effectiveness of tonabersat as a preventive drug were negative, and conflicting results were obtained in other trials concerning its ability to relieve attacks. In contrast, in another clinical trial, tonabersat showed a preventive effect on attacks of migraine with aura but had no efficacy on non-aura attacks. Gap junction channels seem to be involved in several ways in the pathophysiology of migraine with aura and emerge as a new promising putative target in treatment of this disorder.

Glioblastoma cells are characterized by high proliferation and invasive capacities. Tumor development has been associated with a decrease of gap-junctional intercellular communication, but the concrete involvement of gap junction proteins, connexins, remains elusive since they are also suspected to promote cell invasion. In order to better understand how connexins control the glioma cell phenotype, we studied the consequences of inhibiting the intrinsic expression of the major astrocytic connexin, Connexin43, in human U251 glioblastoma cells by the shRNA strategy. The induced down-regulation of Cx43 expression has various effects on the U251 cells such as increased clonogenicity, angiogenesis and decreased adhesion on specific extracellular matrix proteins. We demonstrate that the invasion capacity measured in vitro and ex vivo correlates with Cx43 expression level. For the first time in a cancer cell context, our work demonstrates that Cx43 cofractionates, colocalizes and coimmunoprecipitates with a lipid raft marker, caveolin-1 and that this interaction is inversely correlated to the level of Cx43. This localization of Cx43 in these lipid raft microdomains regulates both homo- and heterocellular gap junctional communications (respectively between U251 cells, or between U251 cells and astrocytes). Moreover, the adhesive and invasive capacities are not dependent, in our model, on Cav-1 expression level. Our results tend to show that heterocellular gap junctional communication between cancer and stroma cells may affect the behavior of the tumor cells. Altogether, our data demonstrate that Cx43 controls the tumor phenotype of glioblastoma U251 cells and in particular, invasion capacity, through its localization in lipid rafts containing Cav-1., (Copyright © 2011 Wiley Periodicals, Inc.)

Introduction: The Nexfin device estimates arterial pressure by the volume clamp method through a finger pneumatic cuff. It also allows to estimate cardiac index (CInoninv) by pulse contour analysis of the non-invasive arterial pressure curve. We evaluated the ability of the device to track changes in cardiac index induced by a fluid challenge., Methods: We included 45 patients for whom a volume expansion (500 mL of saline infused over 30 min) was planned. The volume expansion-induced changes in cardiac index measured by transpulmonary thermodilution (CIinv, PiCCO device) and in CInoninv were recorded., Results: In seven patients, the Nexfin could not record the arterial curve due to finger hypoperfusion. Considering both the values obtained before and after volume expansion (n = 76 pairs of measurements), the bias (lower and upper limits of agreement) between CIinv and CInoninv was 0.2 (-1.8 to 2.2) L/min/m2. The mean change in CInoninv was 10 ± 11%. The percentage error of CInoninv was 57%. The correlation between the changes in CIinv and CInoninv observed during volume expansion was significant (P = 0.0002) with an r2 = 0.31., Conclusions: The estimation of CI by the Nexfin device in critically ill patients is not reliable, neither for estimating absolute values of CI nor for tracking its changes during volume expansion.

Despite the tremendous amount of data over the last 40years, lack of gap junctional intercellular communication (GJIC) or altered expression of gap junction proteins is still a lesser known 'hallmark' of cancer. Expression of astrocytic gap junction protein, connexin43 (Cx43), is often reduced in astrocytomas, the most common neoplasia of the central nervous system (CNS) in adults. Supported by a number of evidences, the global decrease of Cx43 expression appears to be advantageous for the growth of glioma cells. Although the mechanisms by which Cx43 regulates the expression levels of proteins involved in cell growth is unclear, there are evidences to suggest that it might be independent of their channel forming properties. In this regard, the carboxyl tail of Cx43 may have the ability to control the translocation of transcription factor regulators into the nucleus. However, this putative tumor suppressor effect of Cx43 is counterbalanced by its capacity to enhance the migration of glioma cells out of the tumor core through mechanisms that seems to implicate its carboxyl tail, possibly by interacting with the actin cytoskeleton. This ambivalence between the tumor suppressor effect and promotion of cell migration may partly be explained by the heterogeneous expression of Cx43 in the glioma core especially at the malignant glioblastoma stage; some tumor cells would be expected to migrate (Cx43 expressing cells) and others to proliferate (non-expressing Cx43 cells). Moreover, the involvement of Cx43 in glioma progression seems to be more complex since, in addition, GJIC may increase their resistance to apoptosis and Cx43 may also affect cell homeostasis in a paracrine fashion via hemichannel action. In conclusion, Cx43 appears to be involved at different levels of the glioma progression by acting on cell growth regulation, promotion of cell migration and resistance to apoptosis. This article is part of a Special Issue entitled: The Communicating junctions, composition, structure and characteristics., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Lipid rafts are specific microdomains of plasma membrane which are enriched in cholesterol and sphingolipids. These domains seem to favour the interactions of particular proteins and the regulation of signalling pathways in the cells. Recent data have shown that among the proteins, which are preferentially localized in lipid rafts, are connexins that are the structural proteins of gap junctions. Since gap junctional intercellular communication is involved in various cellular processes and pathologies such as cancer, we were interested to review the various observations concerning this specific localization of connexins in lipid rafts and its consequences on gap junctional intercellular communication capacity. In particular, we will focus our discussion on the role of the lipid raft-connexin connection in cancer progression. This article is part of a Special Issue entitled: The Communicating junctions, composition, structure and characteristics., (Copyright © 2011 Elsevier B.V. All rights reserved.)

For decades, cancer was associated with gap-junction defects. However, more recently it appeared that the gap junction proteins (connexins) could be re-expressed and participate to cancer cell dissemination during the late stages of tumor progression. Since primary tumors of prostate cancer (PCa) are known to be connexin deficient, it was interesting to verify whether their bone-targeted metastatic behaviour could be influenced by the re-expression of the connexin type (connexin43) which is originally present in prostate tissue and highly expressed in bone where it participates to the differentiation of osteoblastic cells. Thus, we investigated the effect of the increased Cx43 expression, by retroviral infection, on the metastatic behaviour of two well-characterized cell lines (PC-3 and LNCaP) representing different stages of PCa progression. It appeared that Cx43 differently behaved in those cell lines and induced different phenotypes. In LNCaP, Cx43 was functional, localized at the plasma membrane and its high expression was correlated with a more aggressive phenotype both in vitro and in vivo. In particular, those Cx43-expressing LNCaP cells exhibited a high incidence of osteolytic metastases generated by bone xenografts in mice. Interestingly, LNCaP cells were also able to decrease the proliferation of cocultured osteoblastic cells. In contrast, the increased expression of Cx43 in PC-3 cells led to an unfunctional, cytoplasmic localization of the protein and was correlated with a reduction of proliferation, adhesion and invasion of the cells. In conclusion, the localization and the functionality of Cx43 may govern the ability of PCa cells to metastasize in bones.

Background: Gap junctions are membrane structures composed of connexins (Cx) that allow diffusion of small molecules between cells. They are involved in tissue homeostasis, and various organ dysfunctions have been associated with gap junction defects. To verify their possible involvement in thyroid pathologies, the expression of connexin43 (Cx43), the major Cx in the human thyroid, was evaluated in a variety of diseases including cancer., Methods: There were 122 samples from various thyroid pathologies that were collected to analyze the presence of Cx43 by immunofluorescence. Through confocal microscopy, different patterns of Cx43 localization were identified as normal (membrane) or abnormal (cytoplasmic or lack of detection). The analysis of Cx43 expression was further performed by quantitative reverse transcriptase-polymerase chain reaction and immunohistochemistry in a subset of 25 papillary carcinomas and compared with nontumoral thyroid tissues., Results: The presence of Cx43 was commonly altered in thyroid cancer, as abnormal Cx43 staining was detected in 94.1% of cancer, 47.4% of adenomas, 45.7% of multinodular goiter, 16.7% of Graves' disease, and 25% of thyroiditis. In papillary carcinoma samples, the deregulation of Cx43 expression was mostly the consequence of a decrease of Cx43 mRNA (68% of cases) when compared with normal tissue. When Cx43 mRNA was not downregulated (32% of cases), both loss of membrane staining and aberrant cytoplasmic distribution of the protein were observed., Conclusions: These results show that aberrations of Cx43 expression are associated with thyroid papillary carcinoma.

Purpose: To evaluate efficacy and adverse events related to inhaled sevoflurane for long-term sedation compared with standard intravenous (i.v.) sedation with propofol or midazolam., Methods: Randomized controlled trial. Sixty intensive care unit (ICU) patients expected to require more than 24 h sedation were randomly assigned to one of three groups: group S, inhaled sevoflurane; group P, i.v. propofol; group M, i.v. midazolam. All patients also received i.v. remifentanil for goal-directed sedation (Ramsay scale and pain score) until extubation or for a maximum of 96 h. Primary end points were wake-up times and extubation delay from termination of sedative administration. Proportion of time within Ramsay score 3-4, i.v. morphine consumption at 24 h post extubation, hallucination episodes after end of sedation, adverse events, inorganic fluoride plasma levels, and ambient sevoflurane concentrations were recorded., Results: Forty-seven patients were analyzed. Wake-up time and extubation delay were significantly (P<0.01) shorter in group S (18.6 ± 11.8 and 33.6 ± 13.1 min) than in group P (91.3 ± 35.2 and 326.11 ± 360.2 min) or M (260.2 ± 150.2 and 599.6 ± 586.6 min). Proportion of time within desired interval of sedation score was comparable between groups. Morphine consumption during the 24 h following extubation was lower in group S than in groups P and M. Four hallucination episodes were reported in group P, five in group M, and none in group S (P=0.04). No hepatic or renal adverse events were reported. Mean plasma fluoride value was 82 μmol l(-1) (range 12-220 μmol l(-1)), and mean ambient sevoflurane concentration was 0.3 ± 0.1 ppm., Conclusions: Long-term inhaled sevoflurane sedation seems to be a safe and effective alternative to i.v. propofol or midazolam. It decreases wake-up and extubation times, and post extubation morphine consumption, and increases awakening quality., (© Copyright jointly held by Springer and ESICM 2011)

Connexin43 (Cx43) is a ubiquitously expressed member of the gap junction protein family that mediates gap junction intercellular communication (GJIC) by allowing exchange of cytosolic materials. Previous studies have used Cx43 truncated at the cytoplasmic tail (C-tail) to demonstrate that the C-tail is essential to regulate cell growth and motility. Therefore, the aim of our study was to delineate the respective role of the truncated Cx43 and the C-tail in mediating Cx43-dependent signaling. A truncated Cx43 expressing the channel part of the protein (TrCx43, amino acid 1-242) and a construct encompassing only the C-tail from amino acid 243 (243Cx43) were transduced into LN18 human glioma cells. Our results showed that the ability of Cx43 to suppress growth was independent of GJIC as assessed by dye transfer, but was dependent on the presence of a rigid extracellular matrix. We further demonstrated that the C-tail alone is sufficient to promote motility. Surprisingly, Cx43 is also able to increase migration in the absence of the C-tail, suggesting the presence of at least two distinct signaling mechanisms utilized by Cx43 to affect motility. Finally, we used time-lapse imaging to examine the behavior of migrating cells and it was apparent that the C-tail was associated with a lamellipodia-based migration not observed in either mock or TrCx43 expressing LN18 cells. Our study shows for the first time that a free C-tail is sufficient to induce Cx43-dependent changes in cell morphology and that Cx43 signaling is linked to the regulation of the actin cytoskeleton., ((c) 2010 Wiley-Liss, Inc.)

Background: Congenital cleft palate (CP) is a common and painful surgical procedure in infants. CP repair is associated with the risk of postoperative airway obstruction, which may be increased with administration of opioids, often needed for analgesia. No described regional anesthesia technique can provide adequate pain control following CP repair in infants. The primary aim of this prospective and descriptive study was to observe the effectiveness of bilateral maxillary nerve blocks (BMB) using a suprazygomatic approach on pain relief and consumption of rescue analgesics following CP repair in infants. Analgesic consumption was compared to retrospective data. Complications related to this new technique in infants were also reviewed., Methods: The landmarks and measurements recently defined in a three-dimensional study using computed tomography in infants were used. After general anesthesia, a BMB was performed bilaterally with 0.15 ml x kg(-1) 0.2% ropivacaine in infants scheduled for CP repair. Postoperative analgesia, administration of rescue analgesics, adverse effects, and time to feed were recorded in the 48-h period following surgery and compared to retrospective data., Results: Thirty-three children, mean age 5 +/- 1.8 months and weight 8.3 +/- 1.2 kg, were studied. Eighteen patients out of 33 (55%) did not require additional opioids intra-operatively, vs two out of 20 (10%) without block. None needed morphine postoperatively, and intravenous nalbuphine was required in only six children (18%), vs 16 (80%) without block. Median time to feed was 8 h (range 2-24 h), vs 13 h (4-25) without block. No technical failure or complication related to the BMB was reported., Conclusion: BMB using a suprazygomatic approach seems to improve pain relief, to decrease peri-operative consumption of opioids, and to favor early feeding resumption after CP repair in infants.

Bone is a dynamic tissue that undergoes a precise remodeling process involving resorptive osteoclastic cells and bone-forming osteoblastic (OB) cells. The functional imbalance of either of these cell types can lead to severe skeletal diseases. The proliferation and differentiation of OB cells play a major role in bone development and turnover. These cellular processes are coordinated by connexin43 (Cx43)-based gap-junctional intercellular communication (GJIC) and by soluble factors such as endothelin-1 (ET-1). We have used the Cx43 heterozygous (Cx43(+/-)) murine model to study the possible cross-talk between Cx43 and ET-1 in cultured calvarial OB cells. On microcomputed tomographic analysis of 3-day-old pups, Cx43(+/-) mice showed hypomineralized calvaria in comparison with their Cx43(+/+) littermates. Characterization of cultured OB cells clearly demonstrated the effect of the partial deletion of the Cx43 gene on its expression, on GJIC, and subsequently on OB differentiation. In this model, ET-1 (10(-8) M) lost its mitogenic action in Cx43(+/-) OB cells compared with Cx43(+/+) cells. Moreover, a correlation between the inhibition of cell differentiation by ET-1 and the decreased amount and function of Cx43 was found in Cx43(+/+) OB cells but not in their Cx43(+/-) counterparts. Thus, as Cx43 is linked to OB differentiation, our data indicate that this mitogenic ET-1 peptide has pronounced effects on fully differentiated OB cells. With respect to roles in mechanotransduction and OB differentiation, Cx43 might modulate osteoblastic sensitivity to soluble factors.

Among gene therapy strategies elaborated to kill cancer cells, one uses the CodA gene, coding for cytosine deaminase (CD) that converts 5-fluorocytosine (5-FC) into toxic 5-fluorouracil (5-FU). To enhance 5-FC metabolic activation, we prepared a vector carrying CodA and upp (uracil phosphoribosyl transferase) genes which rendered HeLa cells sensitive to 5-FC and enhanced a bystander effect not mediated by gap junctions. However, 1% CD(+)-UPP(+) cells were able to kill 40% of the cell population if the cells were communicating. This suggests that, at very low percentages of CD(+)-UPP(+) cells, CodA and upp induce a bystander effect through gap junction-dependent mechanisms.

Cancer was one of the first pathologies to be associated with gap-junction defect. Despite the evidence accumulated over the last 40-year period, the molecular involvement of gap junctions and their structural proteins (connexins) in cancer has not been elucidated. The lack of a satisfying explanation may come from the complexity of the disease, evolving through various stages during tumor progression, with cancer cells exhibiting different phenotypes. Here, the question of the involvement of gap junctions has been readdressed by considering the connexin expression/function level at different fundamental stages of carcinogenesis (cell proliferation, cell invasion, and cancer cell dissemination). By performing this analysis, it becomes clear that gap junctions are probably differently involved, depending on the stage of the cancer progression considered. In particular, the most recent data suggest that connexins may act on cell growth by controlling gene expression through a variety of processes (independent of or dependent on the gap-junctional communication capacity). During invasion, connexins have been demonstrated to enhance adherence of cancer cells to the stroma, migration, and probably their dissemination by establishing communication with the endothelial barrier. All these data present a complex picture of connexins in various functions, depending on the cell phenotype.

Gap junctions are cellular structures which permit direct exchanges of small molecules from cytoplasm to cytoplasm in most of the cells of metazoan organisms. For four decades, it has been observed that the inhibition of this type of intercellular communication is often associated with tumorigenesis. The assumption that loss of homeostasis which characterizes tumor growth could be a consequence of a lack of gap junctional intercellular communication (GJIC) has been reinforced by strategies able to reinduce both GJIC and normalization of the phenotype. So far, no molecular data may explain clearly how gap junctions can regulate cell proliferation. It has been argued that the gap-junction tumor suppressive effect may depend specifically on the connexin type which is expressed. For instance, the transfection of connexin30 (Cx30), a gap junction protein, has been previously associated with a slower growth of rat glioma cells (9L cells). Here, we show that these cells do communicate less compared to the Cx43-expressing parental cells even if the Cx30-transfected cells do express more Cx43. This result was related to the cytoplasmic distribution of Cx43 and a nuclear localization of both the Cx30 and a 20-kDa fragment corresponding to a Cx43 signal. According to these data, it seems that cell growth regulation may depend more on the behavior of connexins than the simple establishment of GJIC., ((c) 2007 Wiley-Liss, Inc.)

Gap junctional intercellular communication (GJIC) permits coordinated cellular activities during developmental and differentiation processes. In bone, the involvement of the gap junctional protein, connexin-43 (Cx43), and of GJIC in osteoblastic differentiation and mineralization of the extracellular matrix has been previously demonstrated. Former studies have shown that endothelin-1 (ET-1) was also implicated in the control of osteoblastic proliferation and differentiation. However, depending on the cellular models, ET-1 has been shown to decrease or increase osteoblastic differentiation markers. As no data were available on the ET-1 effect on GJIC and Cx43 expression in osteoblastic cells, we analyzed here the possible crosstalk between Cx43 and ET-1 in a human cell line (hFOB 1.19) which displays different Cx43 expression levels and phenotypes when cultured at 33.5 or 39 degrees C. The presence of ET-1 (10(-8) M) for 2-12 days of culture did not significantly alter the proliferation rate of hFOB cells whatever their phenotype. In contrast, ET-1 induced a differential inhibitory effect on the biochemical differentiation markers (alkaline phosphatase activity and osteocalcin expression) with a significant reduction in the differentiated phenotype at 39 degrees C, whereas no effects were measured at 33.5 degrees C. The inhibitory effect was linked to a decrease of GJIC and of Cx43 both at transcriptional and protein levels. Altogether, our results suggest that Cx43 expression level could influence the action of ET-1 on human osteoblastic cell differentiation. Our data also indicate that the gap junctional protein could play a pivotal role in the response of osteoblasts to mitogenic factors implicated in bone pathologies., (Copyright (c) 2007 Wiley-Liss, Inc.)

Objectives: Connexins (Cx) are proteins that form the gap junctional channels at neighbouring plasma membranes between adjacent cells. Cxs are involved in cell communication, which is reportedly correlated with cell proliferation and differentiation. Alterations in connexin expression and/or gap junctional intercellular communication (GJIC) capacity have long been postulated to be important in a number of pathological conditions including cancer. This study was performed to determine the consequences of the deletion of a single allele of Gja1 (Cx43 gene) in Alveolar Type II cells (APTIIs), and its impact on GJIC and cell proliferation., Material and Methods: In order to do so, APTIIs from wild type (Cx43(+/+)) and heterozygous (Cx43(+/-)) mice were harvested and cultured for 4 days. The GJIC capacity was evaluated by scrape-loading method, with the transfer of lucifer yellow dye. The expression of Cx43 was evaluated by immunofluorescence method and Western blotting. Cell proliferation was evaluated by 3-(4,5-dimethylthazol-2-yl)-2,5-diphenyltetrazolium bromide assay., Results: It was observed that GJIC capacity was significantly reduced and cell proliferation index was significantly higher in Cx43(+/-) cells compared to Cx43(+/+) cells., Conclusions: These results show that knocking out one allele of Cx43 leads to a lower cell to cell communication capacity, and consequently induces a higher cell proliferation. Because chemically induced lung adenomas in mice are known to originate from APTIIs, these alterations may play a critical role in their susceptibility to lung carcinogenesis.

During bone remodeling, osteoblastic (OB) cells have a central role leading to the production of extracellular matrix and its subsequent mineralization. As revealed by human physiopathologies, the OB differentiation process is essential for the control of calcium metabolism and normal bone formation. Moreover, accumulating data in the field of bone development suggest that connexin 43 (Cx43)-mediated gap junctional communication plays an important role in OB differentiation and function. Since Ca(2+) has a central role in OB physiology, the aim of the present study was to investigate the hypothetical involvement of Cx43 in OB calcium homeostasis. We performed measurements of intracellular calcium activity ([Ca(2+)]( i )) by a cytofluorimetric method using Fluo-4 as a calcium indicator and endothelin-1 (ET-1) as a physiological calcium-mobilizing factor on cultured OB cells isolated from calvaria of Cx43(+/-) and Cx43(+/+) mice. Partial deletion of the Cx43 gene induced a significant decrease in the [Ca(2+)]( i ) rise elicited by ET-1. This reduction was not correlated to a decrease or a modification of ET receptor subtype expression as assessed by real-time reverse-transcription polymerase chain reaction. Pharmacological investigations led us to demonstrate that the significant difference in [Ca(2+)]( i ) peak amplitude during the ET-1 action was associated with decreased calcium influx involving L-type voltage-sensitive calcium channels, whereas calcium release from intracellular stores and implication of phospholipase C were not affected by the reduced expression of Cx43. In conclusion, our data demonstrate for the first time that the Cx43 level of expression and/or function is able to modulate the [Ca(2+)]( i ) mobilization in OB cells.

The constituent proteins of gap junctions, called "connexins" (Cxs) in chordates, are generally renewed several times a day, in approximately the same rate range as many other integral plasma membrane proteins and the proteins of other channels, other intercellular junctions or different membrane receptors. This permanent renewal turns on a fine-tuned balance among various processes, such as gene transcription, mRNA stability and processing, protein synthesis and oligomerization, posttranslational modifications, transport to the plasma membrane, anchoring to the cytoskeleton, connexon aggregation and docking, regulation of endocytosis and controlled degradations of the proteins. Subtle changes at one or some of these steps would represent an exquisite level of regulation that extends beyond the rapid channel opening and closure events associated with channel gating; membrane channels and receptors are constantly able to answer to physiological requirements to either up- or downregulate their activity. The Cx turnover rate thereby appears to be a key component in the regulation of any protein, particularly of gap junctional proteins. However, the physiological stimuli that control the assembly of Cxs into gap junctions and their degradation remain poorly understood.

Granuloma formation involves a coordinated interaction between monocytes and macrophages, epithelioid cells, lymphocytes, eosinophils, neutrophils and fibroblasts. It has been established that extracellular communication via cytokines is important for the assembly of granulomas. However, the importance of gap junctions and intercellular communication to granuloma formation and development had never been assessed. Connexins are proteins that form gap junctions, and connexin 43 (Cx43) is present in macrophages, lymphoid cells, myelogenous cells, fibroblasts and others. We analyzed the effect of heterologous deletion of Gja1 (Cx43 gene) on the formation and development of hepatic granulomas induced by Schistosoma mansoni eggs. Heterozygous (Cx43(+/-)) and wild-type (Cx43(+/+)) mice were infected subcutaneously with S. mansoni cercarie and evaluated after 6, 8 and 12 weeks. Granuloma cells express Cx43, as revealed by real-time PCR in isolated granulomas, and by immunohistochemistry. Cx43 expression was reduced in Cx43(+/-) mice, as expected. No differences in the average area of granulomas or number of cells per granuloma were observed between mice of different genotypes. However, granuloma cells from Cx43(+/-) mice displayed a reduced index of the proliferating cell nuclear antigen (PCNA) labeling at 8 and 12 weeks post-infection. Moreover, Cx43(+/-) granulomas unexpectedly presented a higher degree of fibrosis, quantified by morphometric analysis in Sirius Red-stained slides. Our results indicate that the deletion of one allele of the Cx43 gene, and possibly the reduced gap junction intercellular communication capacity (GJIC), may impair the interactions between granuloma cells, reducing their proliferation and increasing their collagen content, thereby modifying the characteristics of S. mansoni granuloma in mice.