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Producción Científica, The mobility of the primate tongue allows for the manipulation of food, but, in addition, houses both general sensory afferents and special sensory end organs. Taste buds can be found across the tongue, but the ones found within the fungiform papillae on the anterior two thirds of the tongue are the first gustatory structures to come into contact with food, and are critical in making food ingestion decisions. Comparative studies of both the macro and micro anatomy in primates are sparse and incomplete, yet there is evidence that gustatory adaptation exists in several primate taxa. One is the distally feathered tongues observed in non-destructive nectar feeders, such as Eulemur rubriventer. We compare both the macro and micro anatomy of three lemurid species who died of natural causes in captivity. We included the following two non-destructive nectar feeders: Varecia variegata and Eulemur macaco, and the following destructive flower feeder: Lemur catta. Strepsirrhines and tarsiers are unique among primates, because they possess a sublingua, which is an anatomical structure that is located below the tongue. We include a microanatomical description of both the tongue and sublingua, which were accomplished using hematoxylin–eosin and Masson trichrome stains, and scanning electron microscopy. We found differences in the size, shape, and distribution of fungiform papillae, and differences in the morphology of conical papillae surrounding the circumvallate ones in all three species. Most notably, large distinct papillae were present at the tip of the tongue in nectar-feeding species. In addition, histological images of the ventro-apical portion of the tongue displayed that it houses an encapsulated structure, but only in Lemur catta case such structure presents cartilage inside. The presence of an encapsulated structure, coupled with the shared morphological traits associated with the sublingua and the tongue tip in Varecia variegata and Eulemur macaco, point to possible feeding adaptations that facilitate non-destructive flower feeding in these two lemurids., Consejería de Educación y Ciencia (grant number UO-15-INVES-17)

Despite the great advances in autophagy research in the last years, the specific functions of the four mammalian Atg4 proteases (ATG4A-D) remain unclear. In yeast, Atg4 mediates both Atg8 proteolytic activation, and its delipidation. However, it is not clear how these two roles are distributed along the members of the ATG4 family of proteases. We show that these two functions are preferentially carried out by distinct ATG4 proteases, being ATG4D the main delipidating enzyme. In mammalian cells, ATG4D loss results in accumulation of membrane-bound forms of mATG8s, increased cellular autophagosome number and reduced autophagosome average size. In mice, ATG4D loss leads to cerebellar neurodegeneration and impaired motor coordination caused by alterations in trafficking/clustering of GABAA receptors. We also show that human gene variants of ATG4D associated with neurodegeneration are not able to fully restore ATG4D deficiency, highlighting the neuroprotective role of ATG4D in mammals.

Background: Thin nodular melanoma (NM) often lacks conspicuous melanoma-specific dermatoscopic criteria and escapes clinical detection until it progresses to a thicker and more advanced tumour. Objective: To investigate the dermatoscopic morphology of thin (≤2 mm Breslow thickness) vs. thick (>2 mm) NM and to identify dermatoscopic predictors of its differential diagnosis from other nodular tumours. Methods: Retrospective, morphological case–control study, conducted on behalf of the International Dermoscopy Society. Dermatoscopic images of NM and other nodular tumours from 19 skin cancer centres worldwide were collected and analysed. Results: Overall, 254 tumours were collected (69 NM of Breslow thickness ≤2 mm, 96 NM >2 mm and 89 non-melanoma nodular lesions). Light brown coloration (50.7%) and irregular brown dots/globules (42.0%) were most frequently observed in ≤2 mm NMs. Multivariate analysis revealed that dotted vessels (3.4-fold), white shiny streaks (2.9-fold) and irregular blue structureless area (2.4-fold) were predictors for thinner NM compared to non-melanoma nodular tumours. Overall, irregular blue structureless area (3.4-fold), dotted vessels (4.6-fold) and serpentine vessels (1.9-fold) were predictors of all NM compared to non-melanoma nodular lesions. Limitations: Absence of a centralized, consensus pathology review and cases selected form tertiary centres maybe not reflecting the broader community. Conclusions: Our study sheds light into the dermatoscopic morphology of thin NM in comparison to thicker NM and could provide useful clues for its differential diagnosis from other non-melanoma nodular tumours. © 2020 European Academy of Dermatology and Venereology

Meissner's and Pacinian corpuscles are cutaneous mechanoreceptors responsible for different modalities of touch. The development of these sensory formations in humans is poorly known, especially regarding the acquisition of the typical immunohistochemical profile related to their full functional maturity. Here we used a panel of antibodies (to specifically label the main corpuscular components: axon, Schwann-related cells and endoneurial-perineurial-related cells) to investigate the development of digital Meissner's and Pacinian corpuscles in a representative sample covering from 11 weeks of estimated gestational age (wega) to adulthood. Development of Pacinian corpuscles starts at 13 wega, and it is completed at 4 months of life, although their basic structure and immunohistochemical characteristics are reached at 36 wega. During development, around the axon, a complex network of S100 positive Schwann-related processes is progressively compacted to form the inner core, while the surrounding mesenchyme is organized and forms the outer core and the capsule. Meissner's corpuscles start to develop at 22 wega and complete their typical morphology and immunohistochemical profile at 8 months of life. In developing Meissner's corpuscles, the axons establish complex relationships with the epidermis and are progressively covered by Schwann-like cells until they complete the mature arrangement late in postnatal life. The present results demonstrate an asynchronous development of the Meissner's and Pacini's corpuscles and show that there is not a total correlation between morphological and immunohistochemical maturation. The correlation of the present results with touch-induced cortical activity in developing humans is discussed.

The transformation of mechanical energy into electrical signals is the first step in mechanotransduction in the peripheral sensory nervous system and relies on the presence of mechanically gated ion channels within specialized sensory organs called mechanoreceptors. Piezo2 is a vertebrate stretch‐gated ion channel necessary for mechanosensitive channels in mammalian cells. Functionally, it is related to light touch, which has been detected in murine cutaneous Merkel cell–neurite complexes, Meissner‐like corpuscles and lanceolate nerve endings. To the best of our knowledge, the occurrence of Piezo2 in human cutaneous mechanoreceptors has never been investigated. Here, we used simple and double immunohistochemistry to investigate the occurrence of Piezo2 in human digital glabrous skin. Piezo2 immunoreactivity was detected in approximately 80% of morphologically and immunohistochemically characterized (cytokeratin 20(+), chromogranin A(+) and synaptophisin(+)) Merkel cells. Most of them were in close contact with Piezo2(−) nerve fibre profiles. Moreover, the axon, but not the lamellar cells, of Meissner's corpuscles was also Piezo2(+), but other mechanoreceptors, i.e. Pacinian or Ruffini's corpuscles, were devoid of immunoreactivity. Piezo2 was also observed in non‐nervous tissue, especially the basal keratinocytes, endothelial cells and sweat glands. The present results demonstrate the occurrence of Piezo2 in cutaneous sensory nerve formations that functionally work as slowly adapting (Merkel cells) and rapidly adapting (Meissner's corpuscles) low‐threshold mechanoreceptors and are related to fine and discriminative touch but not to vibration or hard touch. These data offer additional insight into the molecular basis of mechanosensing in humans.

Ion channels are at the basis of the sensory processes including mechanosensing. Some members of the transient receptor potential (TRP) ion channel superfamily have been proposed as mechanosensors, but their putative role in mechanotransduction is controversial. Among them there are TRP canonical 6 (TRPC6) and TRP vanilloid 4 (TRPV4) ion channels, which are known to cooperate in mechanical hyperalgesia. Here, we investigated the occurrence, distribution, and possible colocalization of TRPC6 and TRPV4 in human digital Meissner sensory corpuscles using immunohistochemistry and double immunofluorescence (associate with markers for specific corpuscular constituents). TRPC6 immunoreactivity was restricted to the axon of Meissner corpuscles, whereas TRPV4 was detected in the axon but also in the lamellar cells. Moreover, axonal colocalization of TRPV4 and TRPC6 was found in the digital Meissner corpuscles. Present results demonstrate for the first time the occurrence and colocalization of two ion channels candidates to mechanosensors in human cutaneous mechanoreceptors. The functional significance of these ion channels in that place remains to be clarified, but should be related to different properties of mechanosensitivity. Anat Rec, 300:1022-1031, 2017. © 2016 Wiley Periodicals, Inc.

A Correction to this paper has been published: https://doi.org/10.1038/s41418-021-00783-2

Different microRNAs (miRNAs), including miR-29 family, may play a role in the development of heart failure (HF), but the underlying molecular mechanisms in HF pathogenesis remain unclear. We aimed at characterizing mice deficient in miR-29 in order to address the functional relevance of this family of miRNAs in the cardiovascular system and its contribution to heart disease. In this work, we show that mice deficient in miR-29a/b1 develop vascular remodeling and systemic hypertension, as well as HF with preserved ejection fraction (HFpEF) characterized by myocardial fibrosis, diastolic dysfunction, and pulmonary congestion, and die prematurely. We also found evidence that the absence of miR-29 triggers the up-regulation of its target, the master metabolic regulator PGC1α, which in turn generates profound alterations in mitochondrial biogenesis, leading to a pathological accumulation of small mitochondria in mutant animals that contribute to cardiac disease. Notably, we demonstrate that systemic hypertension and HFpEF caused by miR-29 deficiency can be rescued by PGC1α haploinsufficiency, which reduces cardiac mitochondrial accumulation and extends longevity of miR-29–mutant mice. In addition, PGC1α is overexpressed in hearts from patients with HF. Collectively, our findings demonstrate the in vivo role of miR-29 in cardiovascular homeostasis and unveil a novel miR-29/PGC1α regulatory circuitry of functional relevance for cell metabolism under normal and pathological conditions., Author summary To combat diseases, we first need to gain knowledge on how cells function at the molecular level to maintain normal physiology. One great scientific achievement of the last decade was the identification of thousands of small regulatory RNA molecules, called microRNAs. Strikingly, each microRNA has the potential to fine-tune the expression of hundreds of target genes depending on the spatiotemporal context. Therefore, defects in key microRNAs can contribute to the development of diseases. In the present work, we characterize the role for miR-29 in cardiac function in a mouse model. We found that mice deficient for miR-29 develop life-threatening cardiometabolic alterations that subsequently cause heart failure with diastolic dysfunction and systemic hypertension. We also demonstrate that these pathological phenotypes originate in part by the anomalous up-regulation of the transcriptional coactivator PGC1α, which can lead to mitochondrial hyperplasia in the heart. Genetic removal of one copy of PGC1α significantly attenuated the severity of the cardiovascular phenotype observed in miR-29–deficient mice. In addition, we show that PGC1α expression is misregulated in heart failure patients, suggesting that the implementation of miR-29 replacement therapy could potentially be used to treat these fatal pathologies.

Tuberculous meningitis (TBM) is one of the most serious and difficult to diagnose manifestations of TB. An ADA value >9.5 IU/L has great sensitivity and specificity. However, all available studies have been conducted in areas of high endemicity, so we sought to determine the accuracy of ADA in a low endemicity area. This retrospective study included 190 patients (105 men) who had ADA tested in CSF for some reason. Patients were classified as probable/certain TBM or non-TBM based on clinical and Thwaite’s criteria. Optimal ADA cutoff was established by ROC curves and a predictive algorithm based on ADA and other CSF biochemical parameters was generated. Eleven patients were classified as probable/certain TBM. In a low endemicity area, the best ADA cutoff was 11.5 IU/L with 91 % sensitivity and 77.7 % specificity. We also developed a predictive algorithm based on the combination of ADA (>11.5 IU/L), glucose (

Leptin is an anorectic hormone secreted mainly by peripheral adipocytes but also by other central and peripheral tissues. It acts by means of a receptor called OB-R, influencing not only appetite and body mass but being also involved in many fields like endocrinology, metabolism and reproduction. Immunohistochemistry and qRT-PCR techniques were, respectively, used to demonstrate the presence of leptin and its receptor in the gut of adult zebrafish and to evaluate the leptin gene expression response to feeding and fasting. Immunoreactivity for the antibodies utilized was demonstrated in feeding but not in fasting fish, and the gene expression analysis corroborates the data obtained by immunohistochemistry. Therefore, all the obtained results support the hypothesis of the role of this hormone in food regulation in zebrafish.

Grupo de Estudio de Hepatitis Vírica, of the Sociedad Andaluza de Enfermedades Infecciosas y Microbiología Clínica: HEPAVIR / Red de Investigación en SIDA (RIS-HEP07); J. C. Alados-Arboledas, H. Albendín, M. R. Alemán, M. del Mar Alonso, V. Asensi, M. J. Blanco, J. Borrallo, R. Cabo, Á. Camacho, M. F. Casas, Á. Castro, J. Cucurull, S. Cuéllar, F. CuencaI.de los Santos-Gil, C. Dueñas, E. Fernández, C. Galera, M. C. Gálvez, D. García, P. Geijo-Martínez, A. Gómez, J. L. Gómez, F. Gutiérrez, J. Hernández, J. Hernández, J. Llenas-García, M. Mancebo, M. Márquez, J. M. Martín, L. Martínez, R. Martínez-Álvarez, O. Martínez Madrid, M. del Mar Masiá, N. Merchante, D. Merino, P. Monje, R. Nuñez, M. Omar, E. Ortega, S. Padilla, C. Robledano, R. Pelazas, E. Pérez, I. Pérez-Camacho, M. Pérez-Pérez, B. Pernas, J. J. Portu, M. Raffo, L. M. Real, G. Reina, A. Rivero, A. Rivero-Juárez, A. Romero-Palacios, J. Portilla, P. Rubio, P. Ryan-Murua, P. S.de la Hoya, J.Santos, M. Serrano, C. Toyas, F. Vera-Méndez, A. Vergara, M. V. Hernández, D. V. García., [Objective] The aim of this study was to determine the predictive capacity of response at treatment week (TW) 4 for the achievement of sustained virological response 12 weeks after the scheduled end of therapy date (SVR12) to treatment against hepatitis C virus (HCV) genotype 3 (GT3) infection with all-oral direct-acting antiviral (DAA) -based regimens., [Patients and methods] From a prospective multicohort study, HCV GT3-infected patients who completed a course of currently recommended DAA-based therapy at 33 Spanish hospitals and who had reached the SVR12 evaluation time-point were selected. TW4 HCV-RNA levels were categorized as target-not-detected (TND), below the lower limit of quantification (LLOQTD) and ≥LLOQ., [Results] A total of 123 patients were included, 86 (70%) received sofosbuvir/ daclatasvir ± ribavirin, 27 (22%) received sofosbuvir/ ledipasvir/ ribavirin and 10 (8.1%) received sofosbuvir/ ribavirin, respectively. In all, 114 (92.7%) of the 123 patients presented SVR12 in an on-treatment approach, but nine (7.3%) patients relapsed, all of them had presented cirrhosis at baseline. In those who achieved TND, LLOQTD and ≥LLOQ, SVR12 was observed in 81/83 (98%; 95% CI 91.5%–99.7%), 24/28 (85.7%; 95% CI 67.3%–96%) and 9/12 (75%; 95% CI 42.8%–94.5%), respectively; p(linear association) 0.001. Corresponding numbers for subjects with cirrhosis were: 52/54 (96.3%; 95% CI 87.3%–95.5%), 14/18 (77.8%; 95% CI 52.4%–93.6%) and 7/10 (70%; 95% CI 34.8%–93.3%); p 0.004., [Conclusions] TW4-response indicates the probability of achieving SVR12 to currently used DAA-based therapy in HCV genotype 3-infected individuals with cirrhosis. This finding may be useful to tailor treatment strategy in this setting., This work has been partially funded by the RD12/0017/0012 project as part of the Plan Nacional R+D+I and co-financed by ISCIII-Subdirección General de Evaluación, the Fondo Europeo de Desarrollo Regional (FEDER) and the Consejería de Salud of the Junta de Andalucía (grant number AC-0095-2013 and PI-0492-2012). JAP is the recipient of an intensification grant from the Instituto de Salud Carlos III (grant number Programa-I3SNS). JM is the recipient of a grant from the Servicio Andaluz de Salud of the Junta de Andalucía (grant number B-0037). KN is the recipient of a Miguel Servet research grant from the Instituto de Salud Carlos III (grant number CP13/00187).

Summary Among primates, the two recognized species of chimpanzees (common chimpanzee, Pan troglodytes; pygmy chimpanzee, Pan paniscus) are considered to be the most similar to humans. Importantly, in mammals, the food intake behaviour largely determines the tongue morphology, including the type, proportion and distribution of gustatory and non-gustatory tongue papillae. The lingual papillae form during its development and mature in post-natal life depending on the different feeding. In this study, we have used scanning electron microscopy to analyse the age-related changes in the lingual papillae of foetal, newborn and adult P. troglodytes. Four main types of lingual papillae, denominated filiform, fungiform, foliate and vallate, and one subtype of filiform papillae called conical papillae, were found. The main age-related changes observed in all kinds of papillae were a progressive keratinization and morphological complexity along the lifespan. During the foetal period, there was scarce keratinization, which progressively increases in young animals to adulthood. The number of filiform increased with ageing, and both filiform and fungiform papillae in adult tongues are divided into pseudopapillae. On the other hand, the vallate papillae vary from smooth simple surfaces in foetal tongues to irregular surfaces with grooves and pseudopapillae (microscopic papilla-shaped formations within the papilla itself) in adults. These results describe for the first time the age-related variations in the three-dimensional aspect of lingual papillae of the chimpanzee tongue and provide new data to characterize more precisely these structures in the human closest specie.

Some mechanoreceptors in mammals depend totally or in part on the neurotrophins brain-derived neurotrophic factor (BDNF) and neurotrophin-4 (NT-4), and their receptor TrkB, for development and maintenance. These actions are presumably exerced regulating the survival of discrete sensory neurons in the dorsal root ganglia which form mechanoreceptors at the periphery. In addition, the cells forming the mechanoreceptors also express both neurotrophins and their receptors although large differences have been described among species. Pacinian corpuscles are rapidly adapting low-threshold mechanoreceptors whose dependence from neurotrophins is not known. In the present study, we analyzed expression of TrkB and their ligands BDNF and NT-4 in the cutaneous Pacinian corpuscles of Macaca fascicularis using immunohistochemistry and fluorescent microscopy. TrkB immunoreactivity was found in Pacinian corpuscles where it co-localized with neuron-specific enolase, and occasionally with S100 protein, thus suggesting that TrkB expression is primarily into axons but also in the lamellar cells and even in the outer core. On the other hand, BDNF immunoreactivity was found the inner core cells where it co-localized with S100 protein but also in the innermost layers of the outer core; NT-4 immunostaining was not detected. These results describe for the first time the expression and distribution of a full neurotrophin system in the axon-inner core complex of mature Pacinian corpuscles. The data support previous findings demonstrating large differences in the expression of BDNF-TrkB in mammalian mechanoreceptors, and also suggest the existence of a retrograde trophic signaling mechanism to maintain morphological and functional integrity of sensory neurons supplying Pacinian corpuscles. Anat Rec, 298:624–629, 2015. © 2014 Wiley Periodicals, Inc.

Ionic channels play key roles in the sensory cells, such as transducing specific stimuli into electrical signals. The acid-sensing ion channel (ASIC) family is voltage-insensitive, amiloride-sensitive, proton-gated cation channels involved in several sensory functions. ASIC2, in particular, has a dual function as mechano- and chemo-sensor. In this study, we explored the possible role of zebrafish ASIC2 in olfaction. RT-PCR, Western blot, chromogenic in situ hybridization and immunohistochemistry, as well as ultrastructural analysis, were performed on the olfactory rosette of adult zebrafish. ASIC2 mRNA and protein were detected in homogenates of olfactory rosettes. Specific ASIC2 hybridization was observed in the luminal pole of the non-sensory epithelium, especially in the cilia basal bodies, and immunoreactivity for ASIC2 was restricted to the cilia of the non-sensory cells where it was co-localized with the cilia marker tubulin. ASIC2 expression was always absent in the olfactory cells. These findings demonstrate for the first time the expression of ASIC2 in the olfactory epithelium of adult zebrafish and suggest that it is not involved in olfaction. Since the cilium sense and transduce mechanical and chemical stimuli, ASIC2 expression in this location might be related to detection of aquatic environment pH variations or to detection of water movement through the nasal cavity.

In detecting chemical properties of food, different molecules and ion channels are involved including members of the acid-sensing ion channels (ASICs) family. Consistently ASICs are present in sensory cells of taste buds of mammals. In the present study the presence of ASICs (ASIC1, ASIC2, ASIC3 and ASIC4) was investigated in the taste buds of adult zebrafish (zASICs) using Western blot and immunohistochemistry. zASIC1 and zASIC3 were regularly absent from taste buds, whereas faint zASIC2 and robust zASIC4 immunoreactivities were detected in sensory cells. Moreover, zASIC2 also immunolabelled nerves supplying taste buds. The present results demonstrate for the first time the presence of zASICs in taste buds of teleosts, with different patterns to that occurring in mammals, probably due to the function of taste buds in aquatic environment and feeding. Nevertheless, the role of zASICs in taste remains to be demonstrated.

The endoneurial and/or perineurial origin of the outer core; i.e. the concentric and continuous lamellae located outside the complex formed by the axon and the Schwann-related cells, in human Pacinian corpuscles is still debated. Here we used immunohistochemistry coupled with a battery of antibodies to investigate the expression of perineurial (Glucose transporter 1 and epithelial membrane antigen) or endoneurial (CD34 antigen) markers in human digital Pacinian corpuscles. CD34 immunoreactivity was restricted to one layer immediately outside the inner core, whereas the proper outer core displayed antigens typical of the perineurial cells. These results demonstrate an intermediate endoneurial layer that divides the Pacinian corpuscles into two distinct compartments: the avascular inner neural compartment (formed by the axon and the Schwann-related cells that form the inner core), and the outer non-neural compartment (formed by the outer core). The functional relevance of these findings, if any, remains to be clarified.

The periostin is a matricellular protein expressed in collagen-rich tissues including some dental and periodontal tissues where it is regulated by mechanical forces, growth factors and cytokines. Interestingly the expression of this protein has been found modified in different gingival pathologies although the expression of periostin in normal human gingiva was never investigated. Here we used Western blot and double immunofluorescence coupled to laser-confocal microscopy to investigated the occurrence and distribution of periostin in different segments of the human gingival in healthy subjects. By Western blot a protein band with an estimated molecular mass of 94 kDa was observed. Periostin was localized at the epithelial-connective tissue junction, or among the fibers of the periodontal ligament, and never co-localized with cytokeratin or vimentin thus suggesting it is an extracellular protein. These results demonstrate the occurrence of periostin in adult human gingiva; its localization suggests a role in the bidirectional interactions between the connective tissue and the epithelial cells, and therefore in the physiopathological conditions in which these interactions are altered. Â

Acid-sensing ion channels (ASICs) are H(+)-gated, voltage-insensitive cation channels involved in synaptic transmission, mechanosensation and nociception. Different ASICs have been detected in the retina of mammals but it is not known whether they are expressed in adult zebrafish, a commonly used animal model to study the retina in both normal and pathological conditions. We study the expression and distribution of ASIC2 and ASIC4 in the retina of adult zebrafish and its regulation by light using PCR, in situ hybridization, western blot and immunohistochemistry. We detected mRNA encoding zASIC2 and zASIC4.2 but not zASIC4.1. ASIC2, at the mRNA or protein level, was detected in the outer nuclear layer, the outer plexiform layer, the inner plexiform layer, the retinal ganglion cell layer and the optic nerve. ASIC4 was expressed in the photoreceptors layer and to a lesser extent in the retinal ganglion cell layer. Furthermore, the expression of both ASIC2 and ASIC4.2 was down-regulated by light and darkness. These results are the first demonstration that ASIC2 and ASIC4 are expressed in the adult zebrafish retina and suggest that zebrafish could be used as a model organism for studying retinal pathologies involving ASICs.

The occurrence of TrkB in the murine thymus (15-day and 3-month old) was investigated by Northern blot, Western blot and immunohistochemistry. Furthermore, the thymus of 15-day-old mice carrying a non-functional mutation on trkB was analyzed. Both trkB mRNA and 145 kDa TrkB protein were detected. In addition, isolated lymphocytes and stromal cells also expressed this protein. The thymus of homozygous functionally TrkB-deficient animals showed structural and ultrastructural changes consistent with massive death of cortical lymphocytes, confirmed with TUNEL. Present results suggest a role for TrkB in maintaining the survival or preventing massive death of lymphocytes in the mammalian thymus.

Acid-sensing ion channels (ASICs) are a family of H(+)-gated voltage-insensitive ion channels that respond to extracellular acidification by regulating transmembrane Ca(2+) flux. Moreover, ASICs can also be gated by mechanical forces and may function as mechanosensors. The cells of the intervertebral disc (IVD) have an unusual acidic and hyperosmotic microenvironment. Changes in the pH and osmolarity determine the viability of IVD cells and the composition of the extracellular matrix, and both are the basis of IVD degeneration. In this study, the expression of ASICs (ASIC1, ASIC2, ASIC3 and ASIC4) mRNAs and proteins in human healthy and degenerated IVD was evaluated by quantitative reverse transcription-quantitative polymerase chain reaction and Western blot. The distribution of ASIC proteins was determined by immunohistochemistry. The mRNAs for all ASICs were detected in normal human IVD, and significantly increased levels were found in degenerated IVD. Western blots demonstrated the presence of proteins with estimated molecular weights of approximately 68-72 kDa. In both the annulus fibrosus (AF) and nucleus pulposus (NP) of normal IVD, ASIC2 is the most frequently expressed ASIC followed by ASIC3, ASIC1 and ASIC4. In the AF of degenerated IVD, there was a significant increase in the number of ASIC1 and ASIC4 positive cells, whereas in the NP, we found significant increase of expression of ASIC1, ASIC2 and ASIC3. These results describe the occurrence and localization of different ASICs in human healthy IVD, and their increased expression in degenerated IVD, thus suggesting that ASICs may be involved in IVD degeneration.

Sensory cells contain ion channels involved in the organ-specific transduction mechanisms that convert different types of stimuli into electric energy. Here we focus on small-conductance calcium-activated potassium channel 1 (SK1) which plays an important role in all excitable cells acting as feedback regulators in after-hyperpolarization. This study was undertaken to analyze the pattern of expression of SK1 in the zebrafish peripheral nervous system and sensory organs using RT-PRC, Westernblot and immunohistochemistry. Expression of SK1 mRNA was observed at all developmental stages analyzed (from 10 to 100 days post fertilization, dpf), and the antibody used identified a protein with a molecular weight of 70kDa, at 100dpf (regarded to be adult). Cell expressing SK1 in adult animals were neurons of dorsal root and cranial nerve sensory ganglia, sympathetic neurons, sensory cells in neuromasts of the lateral line system and taste buds, crypt olfactory neurons and photoreceptors. Present results report for the first time the expression and the distribution of SK1 in the peripheral nervous system and sensory organs of adult zebrafish, and may contribute to set zebrafish as an interesting experimental model for calcium-activated potassium channels research. Moreover these findings are of potential interest because the potential role of SK as targets for the treatment of neurological diseases and sensory disorders.

The avian Herbst corpuscles are the equivalent of the Pacinian corpuscles in mammals, and detect vibration and the movement of joints and feathers. Therefore, they can be regarded as rapidly adapting low-threshold mechanoreceptors. In recent years, it has been establish that some ion channels are involved in mechanosensation and are present in both mechanosensory neurons and mechanoreceptors. Here we have used immunohistochemistry to localize some putative mechanoproteins in the Herbst corpuscles from the rictus of Columba livia. The proteins investigated were the subunits of the epithelial Na+ channel (ENaC), the transient-receptor potential vanilloid 4 (TRPV4), and the acid-sensing ion channel 2 (ASIC2). Immunoreactivity for ENaC subunits was never found in Herbst corpuscles, while the axon expressed ASIC2 and TRPV4 immunoreactivity. Moreover, TRPV4 was also detected in the cell forming the inner core. The present results demonstrate for the first time the occurrence of mechanoproteins in avian low-threshold mechanoreceptors and provide further evidence for a possible role of the ion channels in mechanosensation. Anat Rec, 2013. © 2012 Wiley Periodicals, Inc.

It is important to know the spectrum of the microbial aetiology of prosthetic joint infections (PJIs) to guide empiric treatment and establish antimicrobial prophylaxis in joint replacements. There are no available data based on large contemporary patient cohorts. We sought to characterize the causative pathogens of PJIs and to evaluate trends in the microbial aetiology. We hypothesized that the frequency of antimicrobial-resistant organisms in PJIs has increased in the recent years. We performed a cohort study in 19 hospitals in Spain, from 2003 to 2012. For each 2-year period (2003-2004 to 2011-2012), the incidence of microorganisms causing PJIs and multidrug-resistant bacteria was assessed. Temporal trends over the study period were evaluated. We included 2524 consecutive adult patients with a diagnosis of PJI. A microbiological diagnosis was obtained for 2288 cases (90.6%). Staphylococci were the most common cause of infection (1492, 65.2%). However, a statistically significant rising linear trend was observed for the proportion of infections caused by Gram-negative bacilli, mainly due to the increase in the last 2-year period (25% in 2003-2004, 33.3% in 2011-2012; p 0.024 for trend). No particular species contributed disproportionally to this overall increase. The percentage of multidrug-resistant bacteria PJIs increased from 9.3% in 2003-2004 to 15.8% in 2011-2012 (p 0.008), mainly because of the significant rise in multidrug-resistant Gram-negative bacilli (from 5.3% in 2003-2004 to 8.2% in 2011-2012; p 0.032). The observed trends have important implications for the management of PJIs and prophylaxis in joint replacements. N. Benito, (C) 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Acid-sensing ion channel 2 (ASIC2) is a member of the degenerin/epithelial sodium channel superfamily, presumably involved mechanosensation. Expression of ASIC2 has been detected in mechanosensory neurons as well as in both axons and Schwann-like cells of cutaneous mechanoreceptors. In these studies we analysed expression of ASIC2 in the cutaneous sensory corpuscles of Macaca fascicularis using immunohistochemistry and laser confocal-scanner microscopy. ASIC2 immunoreactivity was detected in both Meissner and Pacinian corpuscles. It was found to co-localize with neuron-specific enolase and RT-97, but not with S100 protein, demonstrating that ASIC2 expression is restricted to axons supplying mechanoreceptors. These results demonstrate for the first time the presence of the protein ASIC2 in cutaneous rapidly adapting low-threshold mechanoreceptors of monkey, suggesting a role of this ion channel in touch sense.

Normal development of the lung requires coordinated activation of cascades of signaling pathways initiated by growth factors signaling through their receptors. TrkB and its ligands, brain-derived neurotrophic factor (BDNF) and neurotrophin-4, belong to the neurotrophin family of growth factors, which are expressed in a large variety of non-neuronal tissues including the lung. Aberrant neurotrophin signaling underlies the pathogenesis of several lung-related pathologies, including asthma and lung cancer, however, little is known about the role of neurotrophins in the embryonic development of the lung. To fill this gap in knowledge, we analyzed the pattern of TrkB expression in the murine lung and we observed that TrkB is expressed in alveolar macrophages, type II pneumocytes, neuroepithelial bodies and nerves. Analysis of the structure of lung from mice deficient in TrkB revealed that absence of TrkB signaling results in thinner bronchial epithelium and apparent larger air space, and, more importantly, lack of neuroepithelial bodies, an important reduction in the density of nerve fibres in the bronchial smooth muscle, submucous plexus in bronchioles, and pulmonary artery walls. These findings suggest TrkB is essential for the normal development of the lung and the nervous system in the lung.

The embryonic development of the enteric nervous system (ENS) from neural crest precursor cells requires neurotrophic signaling. Neurotrophins (NTs) are a family of growth factors that bind Trk receptors to signal diverse functions, including development and maintenance of different cell populations in the peripheral nervous system. In this study we investigated the expression and cell localization of TrkB, the high affinity receptor for brain-derived neurotrophic factor and NT-4, in the murine ENS using Western blot and immunohistochemistry. The results demonstrate that enteric glial cells within the ENS express full-length TrkB at all stages tested. The ENS of TrkB deficient mice have reduced expression of glial cell markers, and a disarrangement of glial cells and the plexular neuropil. These results strongly suggest TrkB has essential roles in the normal development and maintenance of glial cells in the ENS. © 2009 Elsevier Ireland Ltd. All rights reserved.

et al., Neurotrophins (NTs) and their signal transducing Trk receptors play a critical role in the development and maintenance of specific neuronal populations in the nervous system of higher vertebrates. They are responsible for the innervation of the inner ear cochlear and vestibular sensory epithelia. Neurotrophins and Trks are also present in teleosts but their distribution in the inner ear is unknown. Thus, in the present study, we used Western-blot analysis and immunohistochemistry to investigate the expression and cell localization of both NTs and Trk receptors in the inner ear of alevins of Salmo salar and Salmo trutta. Western-blot analysis revealed the occurrence of brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3), but not nerve growth factor (NGF), as well as all three Trk receptors, i.e. TrkA, TrkB and TrkC, the estimated molecular weights of which were similar to those expected for mammals. Specific immunoreactivity for neurotrophins was detected mainly in the sensory epithelia. In particular, BDNF immunoreactivity was found in the maculae of the utricle and saccule, whereas NT-3 immunoreactivity was present in the sensory epithelium of the cristae ampullaris. As a rule the sensory epithelia of the inner ear lacked immunoreactivity for Trks, thus excluding possible mechanisms of autocrinia and/or paracrinia. By contrast, overlapping subpopulations of neurons in the statoacoustic ganglion expressed TrkA (about 15%), TrkB (about 65%) and TrkC (about 45%). The present results demonstrate that, as in mammals and birds, the inner ear of teleosts expresses the components of the neurotrophin-Trk system, but their roles remain to be elucidated. © 2006 The Authors Journal compilation © 2006 Anatomical Society of Great Britain and Ireland.

The hairless (hr) gene is expressed in a large number of tissues, primarily the skin, and a mutation in the hr gene is responsible for the typical cutaneous phenotype of hairless mice. Mutant hr mouse strains show immune defects involving especially T cells and macrophages, as well as an age-related immunodeficiency and an accelerated atrophy of the thymus. These data suggest that the hr mutation causes a defect of this organ, although hr transcripts have not been detected in fetal or adult mice thymus. The present study analyses the thymus of young (3 mo) and adult (9 mo) homozygous hr-rh-j mice (a strain of hairless mice) by means of structural techniques and immunohistochemistry to selectively identify thymic epithelial cells, dendritic cells, and macrophages. There were structural alterations in the thymus of both young and adult rh-rh-j mice, which were more severe in older animals. These alterations consisted of relative cortical atrophy, enlargement of blood vessels, proliferation of perivascular connective tissue, and the appearance of cysts. hr-rh-j mice also showed a decrease in the number of epithelial and dendritic cells, and macrophages. Taken together, present results strongly suggest degeneration and accelerated age-dependent regression of the thymus in hr-rh-j mice, which could explain at least in part the immune defects reported in hairless mouse strains.

et al., Mutations in the hairless (hr) gene of mice result in hair follicle and other epithelial defects. The hr gene is expressed at high levels in the brain where it probably participates in the survival and maintenance of some neuronal populations, but whether it also supports glial populations of the central nervous system has been not investigated. To clarify this, quantitative immunohistochemistry for astrocytes (glial fibrillary acidic protein (GFAP)) and microglial cells (CD11b macrophage antigen) was used in the brain of a mutant mouse strain, the hairless (hr-rh-j) type, which carries the homozygous hr gene rhino mutation. The glial cell density was assessed in the cerebral cortex, hippocampus, striatum, hypothalamus and cerebellum of young (3 months) and old (9 months) hr-rh-j mice. No significant differences were found between young wild-type and hr-rh-j mice. The density of GFAP immunoreactive astrocytes normally increased as a function of age, but in older hr-rh-j mice there was a severe reduction (P < 0.01) in the striatum, hypothalamus, and hippocampus. Conversely, the microglial cells were insensible to aging or to hr-rh-j mutation. These results suggest that the hr gene is involved in the maintenance of the GFAP immunoreactive cells in some cerebral areas. Nevertheless, because these animals do not show any neurological signs, the functional significance of the present findings remains to be established. © 2001 Elsevier Science Ireland Ltd. All rights reserved., This study was supported in part by grants form Spanish FIS (00/0958) and UE-Junta de Castilla y León.

Recent work has shown the expression of Neurotrophins low (p75) and high affinity (Trk's A, B, and C) receptors in the developing inner ear sensory neurons of chick and mouse. Likewise the biological significance of such receptor expression was demonstrated by using both Trks and Neurotrophins null mutant mice. The present study was conducted to determine the expression of Trks and p75 proteins in the human inner ear throughout development. Hence to assess the potential role of Neurotrophins in the development of auditory and vestibular specific innervation in man. In other words, we intend to address the issue whether or not what null mutant mice for Trks and p75 have revealed on inner ear development may be relevant for human embryos. Fifty-two inner ears and their cochleovestibular ganglions (CVG) from human embryos and fetuses, ranging from 5 to 24 weeks of pregnancy were analyzed. Both Western blot and immunocytochemistry on frozen sections were used as complementary procedures. Quantitative Western blot studies revealed that Trk-B and C immunoreactivity (IR) appeared by embryonic week 5 in CVG neurons, increased at high levels between embryonic weeks 7 and 12, and later on, in 15 week-old specimens and older began to decrease to minimal levels. Trk-A IR was detected at just moderate levels during 5 and 7 weeks reflecting the presence of NGF high affinity receptors only at these earlier developmental ages. The p75 IR was detected at high degrees in the early stage of the 5th week and at abundant levels in all studied inner ears from the 7th to the 24th pregnancy week. These Western blot observations were corroborated by immunocytochemistry on frozen sections, which also revealed a major distribution of both p75 and Trks on neuronal bodies while p75 appears localized on supporting cells. Our findings reveal a tight correlation between p75 and Trks expression throughout human development and specific inner ear developmental events, such as target-dependent neuronal cell death and afferent hair cells innervation. That kind of association of p75 and Trks temporal pattern with distinctive steps in inner ear developmental schedule, is a feature shared between human embryos and other mammals, such as mouse. Based on the present results and considering them together with the reported phenotype of p75 and Trks null mutant mice, we hypothesize that p75 and Trk receptors, as well as, their binding Neurotrophins may be essential in human inner ear development. Accordingly, they may be required molecules for sensory epitheliums innervation and target-dependent neuronal cell death, during embryogenesis and even early postnatal life, in man. Copyright (C) 1999 Elsevier Science Ireland Ltd., This work was supported in part by grants from Fondo de Investigaciones Sanitarias and Junta de Castilla y León to J.A Vega and J. Represa.

A mutation in the hr gene is responsible for typical epithelium phenotype in hairless mice. As this gene is expressed at high levels not only in the skin but also in the brain, the aim of the study was to clarify its role in the central nervous system. We have analyzed by morphological and immunocytochemical methods (calbindin D-28k, phosphorylated and 200 kDa neurofilament protein) the cerebellum of a mutated mouse strain, the hairless (hr-rh-j) type carrying the homozygous hr gene rhino mutation. The cerebellar cortex was studied in young (3 months) and adult (9 months) wild type and mutated mice. No major structural change was found in any of the groups and neuronal density or neuronal arrangement were similar in mutated animals to their age-matched controls. Nevertheless there were changes in shape and size of the Purkinje neurons in the old mutated animals respect to their normal littermates, while the molecular and the granule cell layers were apparently invariable. Calbindin (CB) immunohistochemistry revealed a significant decrease in the expression of this protein in the Purkinje cells of the aged mutated mice. Immunohistochemistry for a neurofilament protein (NFP) showed a reduction of staining in all the cerebellar cortex layers in the older animals, which was much more evident in the (hr-rh-j) mutated mice. These results suggest that hr gene is involved in the structural maintenance of the mature cerebellar cortex, rather than in the development. Our findings may also be consistent with an accelerated aging of the central nervous system in rh-rh-j mice.