Ouabain's Influence on TRPV4 Channels of Epithelial Cells: An Exploration of TRPV4 Activity, Expression, and Signaling Pathways.

Ouabain, a substance originally obtained from plants, is now classified as a hormone because it is produced endogenously in certain animals, including humans. However, its precise effects on the body remain largely unknown. Previous studies have shown that ouabain can influence the phenotype of epithelial cells by affecting the expression of cell-cell molecular components and voltage-gated potassium channels. In this study, we conducted whole-cell clamp assays to determine whether ouabain affects the activity and/or expression of TRPV4 channels. Our findings indicate that ouabain has a statistically significant effect on the density of TRPV4 currents (dITRPV4), with an EC50 of 1.89 nM. Regarding treatment duration, dITRPV4 reaches its peak at around 1 h, followed by a subsequent decline and then a resurgence after 6 h, suggesting a short-term modulatory effect related to on TRPV4 channel activity and a long-term effect related to the promotion of synthesis of new TRPV4 channel units. The enhancement of dITRPV4 induced by ouabain was significantly lower in cells seeded at low density than in cells in a confluent monolayer, indicating that the action of ouabain depends on intercellular contacts. Furthermore, the fact that U73122 and neomycin suppress the effect caused by ouabain in the short term suggests that the short-term induced enhancement of dITRPV4 is due to the depletion of PIP2 stores. In contrast, the fact that the long-term effect is inhibited by PP2, wortmannin, PD, FR18, and IKK16 suggests that cSrc, PI3K, Erk1/2, and NF-kB are among the components included in the signaling pathways.

Ouabain-Induced Changes in the Expression of Voltage-Gated Potassium Channels in Epithelial Cells Depend on Cell-Cell Contacts.

Ouabain is a cardiac glycoside, initially isolated from plants, and currently thought to be a hormone since some mammals synthesize it endogenously. It has been shown that in epithelial cells, it induces changes in properties and components related to apical-basolateral polarity and cell-cell contacts. In this work, we used a whole-cell patch clamp to test whether ouabain affects the properties of the voltage-gated potassium currents (Ik) of epithelial cells (MDCK). We found that: (1) in cells arranged as mature monolayers, ouabain induced changes in the properties of Ik; (2) it also accelerated the recovery of Ik in cells previously trypsinized and re-seeded at confluence; (3) in cell-cell contact-lacking cells, ouabain did not produce a significant change; (4) Na+/K+ ATPase might be the receptor that mediates the effect of ouabain on Ik; (5) the ouabain-induced changes in Ik required the synthesis of new nucleotides and proteins, as well as Golgi processing and exocytosis, as evidenced by treatment with drugs inhibiting those processes; and (5) the signaling cascade included the participation of cSrC, PI3K, Erk1/2, NF-κB and ß-catenin. These results reveal a new role for ouabain as a modulator of the expression of voltage-gated potassium channels, which require cells to be in contact with themselves.

Dynamics of Aspergillus fumigatus in Azole Fungicide-Containing Plant Waste in the Netherlands (2016-2017).

The treatment of patients suffering from Aspergillus diseases is hampered due to infections with Aspergillus fumigatus that are already resistant to medical azoles. Previous work has suggested that A. fumigatus likely gains resistance through environmental azole exposure in so-called hot spots. Here, we investigated A. fumigatus resistance dynamics over time at three sites at which farmers used azole fungicides for crop protection. Over 16 months, 114 samples were taken from stockpiles of decaying plant waste. A. fumigatus and azole fungicide residues were ubiquitously present in the plant waste. On average, 105A. fumigatus CFU/g was recovered, of which roughly half were itraconazole and tebuconazole resistant. Similar tandem repeat-mediated resistance mechanisms were found in colonies cultured from plant waste as reported in clinical azole-resistant isolates. Our results show a consistent high burden of azole-resistant A. fumigatus in azole-containing plant waste and underscores the need to further investigate resistance-reducing interventions and transmission routes.IMPORTANCEAspergillus fumigatus is consistently present independently on season at a high abundance in plant waste material throughout the sampling period. Our study confirmed that long-term storage sites of azole-containing decaying plant material can indeed be considered hot spots, which can sustain resistance development and maintenance in A. fumigatus Roughly half of individual isolates were azole resistant and carried genetic mutations that are highly similar to those found in patients with azole-resistant invasive aspergillosis. Our work suggests that environmental sources of azole resistance in A. fumigatus may be important, underscoring the need for further studies on environment-to-patient transmission routes.

Ouabain Enhances Gap Junctional Intercellular Communication by Inducing Paracrine Secretion of Prostaglandin E2.

Ouabain is a cardiac glycoside that has been described as a hormone, with interesting effects on epithelial physiology. We have shown previously that ouabain induces gap junctional intercellular communication (GJIC) in wild, sensitive cells (MDCK-S), but not in cells that have become insensitive (MDCK-I) by modifying their Na+-K+-ATPase. We have also demonstrated that prostaglandin E2 (PGE2) is able to induce increased GJIC by a mechanism other than ouabain, that does not depend on Na+-K+-ATPase. In this work we show, by dye transfer assays, that when MDCK-S and MDCK-I are randomly mixed, to form monolayers, the latter stablish GJIC, because of stimulation by a compound released to the extracellular media, by MDCK-S cells, after treatment with ouabain, as evidenced by the fact that monolayers of only MDCK-I cells, treated with a conditioned medium (CM) that is obtained after incubation of MDCK-S monolayers with ouabain, significantly increase their GJIC. The further finding that either (1) pre-treatment with COX-2 inhibitors or (2) addition to CM of antagonists of EP2 receptor abolish CM's ability to induce GJIC in MDCK-I monolayers indicate that PGE2 is the GJIC-inducing compound. Therefore, these results indicate that, in addition to direct stimulation, mediated by Na+-K+-ATPase, ouabain enhances GJIC indirectly through the paracrine production of PGE2.

Prostaglandin E2 Enhances Gap Junctional Intercellular Communication in Clonal Epithelial Cells.

Prostaglandins are a group of lipids that produce diverse physiological and pathological effects. Among them, prostaglandin E2 (PGE2) stands out for the wide variety of functions in which it participates. To date, there is little information about the influence of PGE2 on gap junctional intercellular communication (GJIC) in any type of tissue, including epithelia. In this work, we set out to determine whether PGE2 influences GJIC in epithelial cells (MDCK cells). To this end, we performed dye (Lucifer yellow) transfer assays to compare GJIC of MDCK cells treated with PGE2 and untreated cells. Our results indicated that (1) PGE2 induces a statistically significant increase in GJIC from 100 nM and from 15 min after its addition to the medium, (2) such effect does not require the synthesis of new mRNA or proteins subunits but rather trafficking of subunits already synthesized, and (3) such effect is mediated by the E2 receptor, which, in turn, triggers a signaling pathway that includes activation of adenylyl cyclase and protein kinase A (PKA). These results widen the knowledge regarding modulation of gap junctional intercellular communication by prostaglandins.

Sera from Patients with NMOSD Reduce the Differentiation Capacity of Precursor Cells in the Central Nervous System.

INTRODUCTION: AQP4 (aquaporin-4)-immunoglobulin G (IgG)-mediated neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory demyelinating disease that affects the central nervous system, particularly the spinal cord and optic nerve; remyelination capacity in neuromyelitis optica is yet to be determined, as is the role of AQP4-IgG in cell differentiation. MATERIAL AND METHODS: We included three groups-a group of patients with AQP4-IgG-positive neuromyelitis optica, a healthy group, and a sham group. We analyzed differentiation capacity in cultures of neurospheres from the subventricular zone of mice by adding serum at two different times: early and advanced stages of differentiation. We also analyzed differentiation into different cell lines. RESULTS AND CONCLUSIONS: The effect of sera from patients with NMOSD on precursor cells differs according to the degree of differentiation, and probably affects oligodendrocyte progenitor cells from NG2 cells to a lesser extent than cells from the subventricular zone; however, the resulting oligodendrocytes may be compromised in terms of maturation and possibly limited in their ability to generate myelin. Furthermore, these cells decrease in number with age. It is very unlikely that the use of drugs favoring the migration and differentiation of oligodendrocyte progenitor cells in multiple sclerosis would be effective in the context of neuromyelitis optica, but cell therapy with oligodendrocyte progenitor cells seems to be a potential alternative.

Intranasal Administration of Undifferentiated Oligodendrocyte Lineage Cells as a Potential Approach to Deliver Oligodendrocyte Precursor Cells into Brain.

Oligodendrocyte precursor cell (OPC) migration is a mechanism involved in remyelination; these cells migrate from niches in the adult CNS. However, age and disease reduce the pool of OPCs; as a result, the remyelination capacity of the CNS decreases over time. Several experimental studies have introduced OPCs to the brain via direct injection or intrathecal administration. In this study, we used the nose-to brain pathway to deliver oligodendrocyte lineage cells (human oligodendroglioma (HOG) cells), which behave similarly to OPCs in vitro. To this end, we administered GFP-labelled HOG cells intranasally to experimental animals, which were subsequently euthanised at 30 or 60 days. Our results show that the intranasal route is a viable route to the CNS and that HOG cells administered intranasally migrate preferentially to niches of OPCs (clusters created during embryonic development and adult life). Our study provides evidence, albeit limited, that HOG cells either form clusters or adhere to clusters of OPCs in the brains of experimental animals.

Individual improvements and selective mortality shape lifelong migratory performance.

Billions of organisms, from bacteria to humans, migrate each year and research on their migration biology is expanding rapidly through ever more sophisticated remote sensing technologies. However, little is known about how migratory performance develops through life for any organism. To date, age variation has been almost systematically simplified into a dichotomous comparison between recently born juveniles at their first migration versus adults of unknown age. These comparisons have regularly highlighted better migratory performance by adults compared with juveniles, but it is unknown whether such variation is gradual or abrupt and whether it is driven by improvements within the individual, by selective mortality of poor performers, or both. Here we exploit the opportunity offered by long-term monitoring of individuals through Global Positioning System (GPS) satellite tracking to combine within-individual and cross-sectional data on 364 migration episodes from 92 individuals of a raptorial bird, aged 1-27 years old. We show that the development of migratory behaviour follows a consistent trajectory, more gradual and prolonged than previously appreciated, and that this is promoted by both individual improvements and selective mortality, mainly operating in early life and during the pre-breeding migration. Individuals of different age used different travelling tactics and varied in their ability to exploit tailwinds or to cope with wind drift. All individuals seemed aligned along a race with their contemporary peers, whose outcome was largely determined by the ability to depart early, affecting their subsequent recruitment, reproduction and survival. Understanding how climate change and human action can affect the migration of younger animals may be the key to managing and forecasting the declines of many threatened migrants.

Ouabain Promotes Gap Junctional Intercellular Communication in Cancer Cells.

Gap junctions are molecular structures that allow communication between neighboring cells. It has been shown that gap junctional intercellular communication (GJIC) is notoriously reduced in cancer cells compared to their normal counterparts. Ouabain, a plant derived substance, widely known for its therapeutic properties on the heart, has been shown to play a role in several types of cancer, although its mechanism of action is not yet fully understood. Since we have previously shown that ouabain enhances GJIC in epithelial cells (MDCK), here we probed whether ouabain affects GJIC in a variety of cancer cell lines, including cervico-uterine (CasKi, SiHa and Hela), breast (MDA-MB-321 and MCF7), lung (A549), colon (SW480) and pancreas (HPAF-II). For this purpose, we conducted dye transfer assays to measure and compare GJIC in monolayers of cells with and without treatment with ouabain (0.1, 1, 10, 50 and 500 nM). We found that ouabain induces a statistically significant enhancement of GJIC in all of these cancer cell lines, albeit with distinct sensitivity. Additionally, we show that synthesis of new nucleotides or protein subunits is not required, and that Csrc, ErK1/2 and ROCK-Rho mediate the signaling mechanisms. These results may contribute to explaining how ouabain influences cancer.

Proliferating Neurocristic Hamartoma Arising in a Giant Congenital Nevus: Comparative Genomic Hybridization Findings.

Neurocristic cutaneous hamartomas (NCHs) are rarely reported tumors with divergent differentiation derived from persistently active pluripotent cells from the neural crest. They result from aberrant development of the neuromesenchyme, and they can express fibrogenic, melanocytic, and/or neurosustentacular differentiation. Thus, congenital melanocytic nevus also represents a neurocristic dysplasia of the skin in which cells are melanogenic cells arrested in development located in the reticular dermis, and nodular proliferative neurocristic hamartoma may arise within a congenital melanocytic nevus. The real importance of NCHs is that, although few cases have been reported in the literature, some cases have shown development of melanoma. Moreover, the only previously reported case of a similar "proliferative neurocristic nodule" analyzed with comparative genomic hybridization showed an aberration pattern similar to melanoma. We present a rare case of NCH associated with a congenital nevus in a 7-year-old boy, with classical histological and immunohistochemical features suggesting a "proliferative neurocristic hamartoma". Comparative genomic hybridization assay showed that chromosomal aberrations were absent in the congenital nevus, whereas, interestingly, the proliferative neurocristic proliferation had an aberration pattern similar to proliferative nodules with gains or losses of entire chromosomes only, similar to typical proliferative nodules and supporting the benign behavior of this lesion.

Acquisition of Somatic NRAS Mutations in Central Nervous System Melanocytes: A Predisposing Risk Factor to Primary Melanoma of the Central Nervous System, a Frequently Forgotten Pitfall in Congenital Nevi.

Congenital melanocytic nevi (CMN) are benign melanocytic proliferations that are usually present at birth. A somatic mosaicism for an NRAS point mutation is responsible for the several phenotypic abnormalities that may be associated with congenital nevi. We report the case of a 7-year-old boy with a proliferative nodule (PN) arising in a Giant CMN completely excised and with several visceral and intraspinal melanoma metastases with no evidence of primary cutaneous melanoma. The careful analysis of the clinical, morphologic, and molecular features allowed the distinction of between the benign PN (BPN) and the melanoma. The BPN showed a characteristic comparative genomic hybridization pattern with gains or losses of whole chromosomes, whereas the melanoma displayed gains or losses involving complex partial chromosomal copy number gains or losses. Leptomeningeal melanocytes are more susceptible to transformation by oncogenic NRAS than cutaneous melanocytes, and central nervous system melanomas are more common than cutaneous melanomas in the setting of CMN. Thus, it has been recommended to characterize the congenital disease in patients with 2 CMN at birth, independently of size and site, with a single magnetic resonance imaging screening younger than the age of 1 year.

Evaluation of the Safety and Efficacy of the Therapeutic Potential of Adipose-Derived Stem Cells Injected in the Cerebral Ischemic Penumbra.

INTRODUCTION: Stroke represents an attractive target for cell therapy. Although different types of cells have been employed in animal models with variable results, the human adipose-derived stem cells (hASCs) have demonstrated favorable characteristics in the treatment of diseases with inflammatory substrate, but experience in their intracerebral administration is lacking. The purpose of this study is to evaluate the effect and safety of the intracerebral application of hASCs in a stroke model. METHODS: A first group of Athymic Nude mice after stroke received a stereotactic injection of hASCs at a concentration of 4 × 104/µL at the penumbra area, a second group without stroke received the same cell concentration, and a third group had only stroke and no cells. After 7, 15, and 30 days, the animals underwent fluorodeoxyglucose-positron emission tomography and magnetic resonance imaging; subsequently, they were sacrificed for histological evaluation (HuNu, GFAP, IBA-1, Ki67, DCX) of the penumbra area and ipsilateral subventricular zone (iSVZ). RESULTS: The in vitro studies found no alterations in the molecular karyotype, clonogenic capacity, and expression of 62 kDa transcription factor and telomerase. Animals implanted with cells showed no adverse events. The implanted cells showed no evidence of proliferation or differentiation. However, there was an increase of capillaries, less astrocytes and microglia, and increased bromodeoxyuridine and doublecortin-positive cells in the iSVZ and in the vicinity of ischemic injury. CONCLUSIONS: These results suggest that hASCs in the implanted dose modulate inflammation, promote endogenous neurogenesis, and do not proliferate or migrate in the brain. These data confirm the safety of cell therapy with hASCs.

Lifetime variation in feather corticosterone levels in a long-lived raptor.

In long-lived animals, the challenges that threaten individual homeostasis, and the way they are dealt with, are expected to vary in an age-related manner, encompassing the progressive selection of superior phenotypes and the acquisition and improvement of key skills (e.g. foraging, breeding and fighting abilities). Since exposure to homeostatic challenges typically elevates circulating glucocorticoid (GC) levels in vertebrates (modulating the behavioural and physiological responses that mediate allostasis), we may expect concomitant age-related changes in these hormones. Here, we investigated whether the level of corticosterone (the main avian GC) deposited in feathers during regular moult reflected the expected lifelong progression of energetic challenges in a long-lived raptor, the black kite (Milvus migrans). Feather corticosterone values were highest in the youngest birds, gradually declined to reach minimum levels in prime age, 7- to 11-year-old birds, and then increased again slightly among the oldest, senescent birds (≥12 years old). This pattern mirrored the age-related changes in reproductive success and survival rates previously reported for this population, suggesting that feather corticosterone levels captured the most vulnerable and challenging periods experienced by these birds as they proceeded through life. Moreover, feather corticosterone levels were negatively related to body size, suggesting that larger birds either experienced fewer homeostatic challenges, or were better able to cope with them. Feather corticosterone measures thus provided a valuable snapshot of how allostatic loads vary along the life of individuals, supporting the idea of a tight, long-term link between cumulative physiological responses to ecological challenges and demographic performance.

Lichenoid Granulomatous Mycosis Fungoides.

The presence of a granulomatous reaction in cutaneous lymphomas has been described in the past, especially in mycosis fungoides (MF), where a "granulomatous" variant of the disease is well known. We describe a patient with granulomatous MF (GMF) who has been followed for 13 years presenting with erythematosquamous plaques on his fingers and toes, ankles, heels, and abdomen, which on microscopic examination showed a lichenoid granulomatous reaction admixed with a neoplastic proliferation of small-sized, atypical CD4 lymphocytes. GMF is characterized by a granulomatous reaction intermingled with the dermal infiltrate of MF which may even reach the subcutaneous tissue. Only 7 cases of GMF in which the granulomas were located within the papillary or superficial dermis have been described to date. We report for the first time a unique case of lichenoid GMF where the granulomatous reaction obscures the interface between the epidermis and dermis. Sequential biopsies and complete phenotypic studies were necessary to get an accurate diagnosis.

Segmental lesions along blaschko´s lines in an elderly man.

Darier disease (DD) is an autosomal dominant genodermatosis characterized by multiple keratotic and crusted papules over seborrheic areas, along with a variable involvement of oral mucosa, palmoplantar region, and nails. Segmental subtypes (type 1 and 2) are uncommon clinically limited forms of DD that usually present at middle age with few cutaneous lesions following Blaschko´s lines. We report a case of extensive multi segmental DD type 1 that developed in an elderly man, an unusual clinical onset of DD that dermatologists should bear in mind.

Micosis fungoide e inhibidores del TNFα: ¿riesgo o beneficio?

The growing use of anti-TNF drugs during the last years has reopened the discussion about the possible increased risk of developing non-Hodgkin lymphoma in patients with such type of treatments. We present our clinical experience and critical opinion about the current situation of such issue regarding cutaneous T-cell lymphomas.El creciente uso de fármacos anti-TNF durante los últimos años ha reabierto el debate sobre el posible aumento de riesgo de linfomas no Hodgkin en los pacientes con este tipo de tratamientos. Presentamos nuestra experiencia clínica y opinión critica sobre la situación actual de este tema en relación a los linfomas cutáneos de células T.

Onychoheterotopia Due to a Traumatically Transplanted Nail in a Child.

Onychoheterotopia is a rare condition characterized by ectopic nail tissue growth. It is a digital mass that is commonly misdiagnosed. We describe a 6-year-old girl who presented with onychoheterotopia after trauma to the digit. Her onychoheterotopia was incorrectly diagnosed as a common wart. It is important to include onychoheterotopia in the differential diagnosis of digital masses, especially in the setting of previous traumatic injury.

Atomic force microscopy visualization of injuries in Enterococcus faecalis surface caused by Er,Cr:YSGG and diode lasers.

AIM: To visualize by atomic force microscopy the alterations induced on Enterococcus. faecalis surface after treatment with 2 types of laser: Erbium chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser and Diode laser. MATERIAL AND METHODS: Bacterial suspensions from overnight cultures of E. faecalis were irradiated during 30 seconds with the laser-lights at 1 W and 2 W of power, leaving one untreated sample as control. Surface alterations on treated E. faecalis were visualized by atomic force microscopy (AFM) and its surface roughness determined. RESULTS: AFM imaging showed that at high potency of laser both cell morphology and surface roughness resulted altered, and that several cell lysis signs were easily visualized. Surface roughness clearly increase after the treatment with Er,Cr:YSGG at 2W of power, while the other treatments gave similar values of surface roughness. The effect of lasers on bacterial surfaces visualized by AFM revealed drastic alterations. CONCLUSIONS: AFM is a good tool to evaluate surface injuries after laser treatment; and could constitute a measure of antimicrobial effect that can complete data obtained by determination of microbial viability.