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IntroductionWe have recently demonstrated that Sox10-expressing (Sox10+) cells give rise to mainly type-III neuronal taste bud cells that are responsible for sour and salt taste. The two tissue compartments containing Sox10+ cells in the surrounding of taste buds include the connective tissue core of taste papillae and von Ebner’s glands (vEGs) that are connected to the trench of circumvallate and foliate papillae.MethodsIn this study, we performed single cell RNA-sequencing of the epithelium of Sox10-Cre/tdT mouse circumvallate/vEG complex and used inducible Cre mouse models to map the cell lineages of vEGs and/or connective tissue (including stromal and Schwann cells).ResultsTranscriptomic analysis indicated that Sox10 expression was enriched in the cell clusters of vEG ducts that contained abundant proliferating cells, while Sox10-Cre/tdT expression was enriched in type-III taste bud cells and vEG ductal cells. In vivo lineage mapping showed that the traced cells were distributed in circumvallate taste buds concurrently with those in the vEGs, but not in the connective tissue. Moreover, multiple genes encoding pathogen receptors were enriched in the vEG ducts hosting Sox10+ cells.DiscussionOur data supports that it is the vEGs, not connective tissue core, that serve as the niche of Sox10+ taste bud progenitors. If this is also true in humans, our data indicates that vEG duct is a source of Sox10+ taste bud progenitors and susceptible to pathogen infections.

Sympathetic neurons are affected in familial dysautonomia, a rare disease associated with a mutation in ELP1, but the mechanisms are not fully understood. Here the authors show, using neurons derived from participants with familial dysauotnomia, that spontaneous sympathetic neuron hyperactivity is observed and is associated with norepinephrine transporter deficits.

O-GlcNAcylation is a post-translational modification (PTM) that regulates a wide range of cellular functions and has been associated with multiple metabolic diseases in various organs. The sympathetic nervous system (SNS) is the efferent portion of the autonomic nervous system that regulates metabolism of almost all organs in the body. How much the development and functionality of the SNS are influenced by O-GlcNAcylation, as well as how such regulation could contribute to sympathetic neuron (symN)-related neuropathy in diseased states, remains unknown. Here, we assessed the level of protein O-GlcNAcylation at various stages of symN development, using a human pluripotent stem cell (hPSC)-based symN differentiation paradigm. We found that pharmacological disruption of O-GlcNAcylation impaired both the growth and survival of hPSC-derived symNs. In the high glucose condition that mimics hyperglycemia, hPSC-derived symNs were hyperactive, and their regenerative capacity was impaired, which resembled typical neuronal defects in patients and animal models of diabetes mellitus. Using this model of sympathetic neuropathy, we discovered that O-GlcNAcylation increased in symNs under high glucose, which lead to hyperactivity. Pharmacological inhibition of O-GlcNAcylation rescued high glucose-induced symN hyperactivity and cell stress. This framework provides the first insight into the roles of O-GlcNAcylation in both healthy and diseased human symNs and may be used as a platform for therapeutic studies.

ABSTRACT: Chickens have been reported to have a low taste bud count and thus low taste acuity. However, more recent studies indicate that the earlier reported count of chicken taste buds may have been significantly underestimated. To answer the question of whether the taste sensing system in broiler chickens evolved during the breeding selection over the past decades, we compared the taste sensitivity to bitter and taste buds between a meat-type control strain – the 1955 Athens Canadian Random Bred (ACRB), and a modern high-yielding broiler strain – the 2012 Cobb 500. The behavioral tests showed that the ACRB did not avoid bitter taste solutions of quinine hydrochloride (QHCl) at the examined concentrations (0.5, 1, 2, and 4 mM) (P > 0.05), while the Cobb 500 significantly avoided both the 2 mM and 4 mM QHCl solutions (P < 0.01). The labeling of chicken taste buds using the molecular marker Vimentin revealed that Cobb 500 chickens had a slightly higher number (P < 0.1), but lower density of taste bud clusters in the palate (P < 0.01) and the base of the oral cavity (P < 0.05) compared to the ACRB. We also found that a single amino acid change occurred in the bitter taste receptor T2R7. However, the functional analyses using HEK293T cells transiently expressing T2R7 revealed that the functions of T2R7 were comparable between the two strains. Taken together, our results demonstrated that taste sensitivities could be affected by the selection of the broiler chickens. The modern high-yielding broilers, which have massive feed intake and appetite, had a higher sensitivity to bitter taste stimuli than the meat-type chicken strain which was established decades ago. This evolvement of taste sensitivities may be associated with the alterations of an upper level of taste system, rather than the peripheral taste system, including distribution of taste buds and functions of taste receptors.

Chronic obstructive pulmonary disease (COPD) is an irreversible disease characterized by the limitation of continuous airflow. Eosinophil (EOS) in peripheral blood plays a key role in the acute exacerbation of COPD. Eosinophil-increased COPD has become an important variant of COPD and the focus of individualized treatment of COPD. Numerous studies have shown that an increased eosinophil count or an increased percentage in the peripheral blood closely correlates to the acute exacerbation and prognosis of COPD. Therefore, this study intends to review the progress of domestic and foreign research on the correlation between COPD and EOS.

Abstract RNA-Seq is a powerful tool in transcriptomic profiling of cells and tissues. We recently identified many more taste buds than previously appreciated in chickens using molecular markers to stain oral epithelial sheets of the palate, base of oral cavity, and posterior tongue. In this study, RNA-Seq was performed to understand the transcriptomic architecture of chicken gustatory tissues. Interestingly, taste sensation related genes and many more differentially expressed genes (DEGs) were found between the epithelium and mesenchyme in the base of oral cavity as compared to the palate and posterior tongue. Further RNA-Seq using specifically defined tissues of the base of oral cavity demonstrated that DEGs between gustatory (GE) and non-gustatory epithelium (NGE), and between GE and the underlying mesenchyme (GM) were enriched in multiple GO terms and KEGG pathways, including many biological processes. Well-known genes for taste sensation were highly expressed in the GE. Moreover, genes of signaling components important in organogenesis (Wnt, TGFβ/ BMP, FGF, Notch, SHH, Erbb) were differentially expressed between GE and GM. Combined with other features of chicken taste buds, e.g., uniquely patterned array and short turnover cycle, our data suggest that chicken gustatory tissue provides an ideal system for multidisciplinary studies, including organogenesis and regenerative medicine.

Hypothalamic oxytocin (OT) is released into the brain by cyclic ADP-ribose (cADPR) with or without depolarizing stimulation. Previously, we showed that the intracellular free calcium concentration ([Ca2+]i) that seems to trigger OT release can be elevated by -NAD+, cADPR, and ADP in mouse oxytocinergic neurons. As these -NAD+ metabolites activate warm-sensitive TRPM2 cation channels, when the incubation temperature is increased, the [Ca2+]i in hypothalamic neurons is elevated. However, it has not been determined whether OT release is facilitated by heat in vitro or hyperthermia in vivo in combination with cADPR. Furthermore, it has not been examined whether CD38 and TRPM2 exert their functions on OT release during stress or stress-induced hyperthermia in relation to the anxiolytic roles and social behaviors of OT under stress conditions. Here, we report that OT release from the isolated hypothalami of male mice in culture was enhanced by extracellular application of cADPR or increasing the incubation temperature from 35°C to 38.5°C, and simultaneous stimulation showed a greater effect. This release was inhibited by a cADPR-dependent ryanodine receptor inhibitor and a nonspecific TRPM2 inhibitor. The facilitated release by heat and cADPR was suppressed in the hypothalamus isolated from CD38 knockout mice and CD38- or TRPM2-knockdown mice. In the course of these experiments, we noted that OT release differed markedly between individual mice under stress with group housing. That is, when male mice received cage-switch stress and eliminated due to their social subclass, significantly higher levels of OT release were found in subordinates compared with ordinates. In mice exposed to anxiety stress in an open field, the cerebrospinal fluid (CSF) OT level increased transiently at 5 minutes after exposure, and the rectal temperature also increased from 36.6°C to 37.8°C. OT levels in the CSF of mice with lipopolysaccharide-induced fever (+0.8°C) were higher than those of control mice. The TRPM2 mRNA levels and immunoreactivities increased in the subordinate group with cage-switch stress. These results showed that cADPR/CD38 and heat/TRPM2 are co-regulators of OT secretion and suggested that CD38 and TRPM2 are potential therapeutic targets for OT release in psychiatric diseases caused by social stress.

Taste buds, the sensory organs for taste, have been described as arising solely from the surrounding epithelium, which is in distinction from other sensory receptors that are known to originate from neural precursors, i.e., neural ectoderm that includes neural crest (NC). Our previous study suggested a potential contribution of NC derived cells to early immature fungiform taste buds in late embryonic (E18.5) and young postnatal (P1-10) mice. In the present study we demonstrated the contribution of the underlying connective tissue (CT) to mature taste buds in mouse tongue and soft palate. Three independent mouse models were used for fate mapping of NC and NC derived connective tissue cells: (1) P0-Cre/R26-tdTomato (RFP) to label NC, NC derived Schwann cells and derivatives; (2) Dermo1-Cre/RFP to label mesenchymal cells and derivatives; and (3) Vimentin-CreER/mGFP to label Vimentin-expressing CT cells and derivatives upon tamoxifen treatment. Both P0-Cre/RFP and Dermo1-Cre/RFP labeled cells were abundant in mature taste buds in lingual taste papillae and soft palate, but not in the surrounding epithelial cells. Concurrently, labeled cells were extensively distributed in the underlying CT. RFP signals were seen in the majority of taste buds and all three types (I, II, III) of differentiated taste bud cells, with the neuronal-like type III cells labeled at a greater proportion. Further, Vimentin-CreER labeled cells were found in the taste buds of 3-month-old mice whereas Vimentin immunoreactivity was only seen in the CT. Taken together, our data demonstrate a previously unrecognized origin of taste bud cells from the underlying CT, a conceptually new finding in our knowledge of taste bud cell derivation, i.e., from both the surrounding epithelium and the underlying CT that is primarily derived from NC.

Introduction: We have recently demonstrated that Sox10-expressing (Sox10+) cells give rise to mainly type-III neuronal taste bud cells that are responsible for sour and salt taste. The two tissue compartments containing Sox10+ cells in the surrounding of taste buds include the connective tissue core of taste papillae and von Ebner's glands (vEGs) that are connected to the trench of circumvallate and foliate papillae. Methods: In this study, we performed single cell RNA-sequencing of the epithelium of Sox10-Cre/tdT mouse circumvallate/vEG complex and used inducible Cre mouse models to map the cell lineages of vEGs and/or connective tissue (including stromal and Schwann cells). Results: Transcriptomic analysis indicated that Sox10 expression was enriched in the cell clusters of vEG ducts that contained abundant proliferating cells, while Sox10-Cre/tdT expression was enriched in type-III taste bud cells and vEG ductal cells. In vivo lineage mapping showed that the traced cells were distributed in circumvallate taste buds concurrently with those in the vEGs, but not in the connective tissue. Moreover, multiple genes encoding pathogen receptors were enriched in the vEG ducts hosting Sox10+ cells. Discussion: Our data supports that it is the vEGs, not connective tissue core, that serve as the niche of Sox10+ taste bud progenitors. If this is also true in humans, our data indicates that vEG duct is a source of Sox10+ taste bud progenitors and susceptible to pathogen infections. [ABSTRACT FROM AUTHOR]

Taste papillae are specialized organs, each of which comprises an epithelial wall hosting taste buds and a core of mesenchymal tissue. In the present study, we report that during early taste papilla development in mouse embryos, bone morphogenetic protein (BMP) signaling mediated by type 1 receptor ALK3 in the tongue mesenchyme is required for epithelial Wnt/ß-catenin activity and taste papilla differentiation. Mesenchyme-specific knockout (cKO) of Alk3 using Wnt1-Cre and Sox10-Cre resulted in an absence of taste papillae at E12.0. Biochemical and cell differentiation analyses demonstrated that mesenchymal ALK3-BMP signaling governed the production of previously unappreciated secretory proteins, i.e. it suppressed those that inhibit and facilitated those that promote taste papilla differentiation. Bulk RNA-sequencing analysis revealed many more differentially expressed genes (DEGs) in the tongue epithelium than in the mesenchyme in Alk3 cKO versus control. Moreover, we detected downregulated epithelial Wnt/ß-catenin signaling and found that taste papilla development in the Alk3 cKO was rescued by the GSK3ß inhibitor LiCl, but not by Wnt3a. Our findings demonstrate for the first time the requirement of tongue mesenchyme in taste papilla cell differentiation. [ABSTRACT FROM AUTHOR]

The mammalian skull vault is a highly regulated structure that evolutionally protects brain growth during vertebrate development. It consists of several membrane bones with different tissue origins (e.g. neural crest-derived frontal bone and mesoderm-derived parietal bone). Although membrane bones are formed through intramembranous ossification, the neural crest-derived frontal bone has superior capabilities for osteoblast activities and bone regeneration via TGF, BMP, Wnt, and FGF signaling pathways. Neural crest (NC) cells are multipotent, and once induced, will follow specific paths to migrate to different locations of the body where they give rise to a diverse array of cell types and tissues. Recent studies using genetic mouse models have greatly advanced our knowledge of NC cell induction, proliferation, migration and differentiation. Perturbations or disruptions of neural crest patterning lead to severe developmental defects or diseases. This review summarizes recent discoveries including novel functions of genes or signaling molecules that are capable of governing developmental processes of neural crest patterning, which may function as a gene regulatory network in controlling skull development. The proposed regulatory network will be important to understand how the signaling pathways and genes converge to regulate osteoblast activities and bone formation, which will be beneficial for the potential identification of molecular targets to prevent or alleviate human diseases or disorders involving defective neural crest development. [ABSTRACT FROM AUTHOR]

Appropriate parental care by fathers can greatly facilitate healthy human family life. However, much less is known about paternal behavior in animals compared to those regarding maternal behavior. Previously, we reported that male ICR strain laboratory mice, although not spontaneously parental, can be induced to display maternal-like parental care (pup retrieval) when separated from their pups by signals from the pairmate dam (Liu et al., Nat. Commun, 4:1346, 2013). This parental behavior by the ICR sires, which are not genetically biparental, is novel and has been designated as pairmate-dependent paternal behavior. However, the factors critical for this paternal behavior are unclear. Here, we report that the pairmate-dependent paternal retrieval behavior is observed especially in the ICR strain and not in C57BL/6 or BALB/c mice. An ICR sire displays retrieval behavior only toward his biological pups. A sire co-housed with an unrelated non-pairing dam in a new environment, under which 38-kHz ultrasonic vocalizations are not detected, does not show parenting behavior. It is important for sires to establish their own home territory (cage) by continuous housing and testing to display retrieval behavior. These results indicated that the ICR sires display distinct paternity, including father-child social interaction, and shed light on parental behavior, although further analyses of paternal care at the neuroendocrinological and neurocircuitry levels are required. [ABSTRACT FROM AUTHOR]

Abstract Objective and design  Toll-like receptor 4 (TLR4) is potentially associated with acute pancreatitis (AP), but its exact role remains controversial. IL-1 receptor-associated kinase 4 (IRAK-4) is a common mediator of Toll-like receptors pathways, with an essential role in transducing downstream signals. This study investigates the potential role of the TLR4 pathway, in particular IRAK-4, in a murine model of AP. Methods  Acute pancreatitis was induced in wild-type and TLR4-deficient mice by intraperitoneal injections of caerulein (50 μg/kg). Pancreatic pathological scores and myeloperoxidase activity were dynamically measured, along with pancreatic TLR4 and IRAK-4 mRNA and protein. Results  In wild-type mice, pathological scores and myeloperoxidase activity were rapidly increased at 1, 2 and 4 h, followed by alleviation at 12 and 24 h. In TLR4-deficient mice, they were slightly increased within 2 h, but became more severe at 12 and 24 h. IRAK-4 mRNA and protein were significantly down-regulated at 1, 2 and 4 h in wild-type mice. Unexpectedly, TLR4-deficient mice showed more profound reductions of IRAK-4 mRNA and protein at the same time. Conclusions  TLR4 deficiency delayed the initiation of pancreatitis, implying a potential role for TLR4 during AP. IRAK-4 might function during AP, but independently of TLR4. [ABSTRACT FROM AUTHOR]

CD38, a transmembrane glycoprotein with ADP-ribosyl cyclase activity, catalyses the formation of Ca2+ signalling molecules, but its role in the neuroendocrine system is unknown. Here we show that adult CD38 knockout (CD38-/-) female and male mice show marked defects in maternal nurturing and social behaviour, respectively, with higher locomotor activity. Consistently, the plasma level of oxytocin (OT), but not vasopressin, was strongly decreased in CD38-/- mice. Replacement of OT by subcutaneous injection or lentiviral-vector-mediated delivery of human CD38 in the hypothalamus rescued social memory and maternal care in CD38-/- mice. Depolarization-induced OT secretion and Ca2+ elevation in oxytocinergic neurohypophysial axon terminals were disrupted in CD38-/- mice; this was mimicked by CD38 metabolite antagonists in CD38+/+ mice. These results reveal that CD38 has a key role in neuropeptide release, thereby critically regulating maternal and social behaviours, and may be an element in neurodevelopmental disorders. [ABSTRACT FROM AUTHOR]

Transcutaneous electrical nerve stimulation (TENS) has been shown to be an effective measure for pain relief. The aim of the present study was to determine the optimal intensity and interval of repeated 100 Hz TENS for the treatment of chronic inflammatory hyperalgesia in a monoarthritic pain model of the rat, and to assess the changes of the spinal substance P (SP) release in response to TENS treatment. A reliable, reproducible chronic monoarthritic pain model was produced by intra-articular injection of complete Freund's adjuvant (CFA) at single ankle joint. The efficacy of 100 Hz TENS treatments with different frequencies and intensities was compared. In the acute period (within 3 weeks) of monoarthritis, twice-a-week schedule of TENS reduced the swelling of the inflamed ankle significantly. In the stable period (4-9 weeks), however, once-a-week schedule produced a significantly better therapeutic effect on both inflammation and arthritic hyperalgesia than that of twice- or five-times-a-week schedule. Using three levels of intensity of TENS, we found that the weaker (1-1-2 mA) stimulation produced significantly better therapeutic effects. Repeated TENS produced a reduction of SP content in spinal perfusate in parallel with the progressive reduction of the arthritic pain scores. Our results suggest that (i) consecutive TENS treatments produced cumulative effect for chronic hyperalgesia, (ii) for chronic inflammatory hyperalgesia, a weaker intensity and more sparsely arranged treatment schedule may produce better therapeutic effect and (iii) a decrease in SP release may serve as one of the possible neurochemical mechanisms underlying the therapeutic effects of multiple TENS treatments on chronic inflammatory hyperalgesia. [ABSTRACT FROM AUTHOR]

Wnt and Shh signaling pathways are critical for the development and maturation of many epithelial tissues. Both pathways have roles in stem cell maintenance, tissue development, and tumorigenesis. However, linkage between these pathways in mammalian systems had not been well established. Here, we report that Shh expression in fungiform papillae and formation of normal mature fungiform papillae depend on signaling through Wnt and β-catenin. We observed that during fungiform papilla formation in mice, Shh and components of the Wnt/β-catenin signaling pathway are expressed together in the developing placode. The elimination of Wnt/β-catenin signaling in either Lef 1 or Wnt10b knockout mice resulted in down-regulation of Shh expression. In addition, the size and number of fungiform papillae were greatly reduced in Lef 1 knockout mice. By examining embryonic mouse tongues in culture we determined that activation of Wnt/β-catenin signaling up-regulates Shh expression. We observed that blocking Shh signaling in cultured tongue explants enhanced papillae formation and was accompanied by an up-regulation of Wnt/β-catenin signaling, indicating that Shh inhibits the Wnt/β-catenin pathway. Exogenously added Shh suppressed expression of endogenous Shh and inhibited Wnt/β-catenin signaling (assessed in TOPGAL mice), further implicating Shh as an inhibitor of the Wnt/β-catenin pathway. Our observations indicate that Wnt/β-catenin signaling and interactions between the Wnt and Shh pathways play essential roles in the development of fungiform papillae. [ABSTRACT FROM AUTHOR]

Neuronal degeneration and astrogliosis are hallmarks of prion disease. Synthetic prion protein (PrP) peptide 106–126 (PrP106–126) can induce death of neurons and proliferation of astrocytes in vitro and this neurotoxic effect depends on the expression of cellular PrP (PrPC) and is hence believed to be PrPC -mediated. To further elucidate the involvement of PrPC in PrP106–126-induced neurotoxicity, we determined the expression of PrP mRNA in primary culture of rat cortical neuron cells, cerebellar granule cells, and astrocytes following treatment with 50μM of PrP106–126 scrambled PrP106–126 by quantitative real-time RT-PCR. As shown by MTT test, PrP106–126 induced significant death of neuron cells and marked proliferation of astrocytes after 10 days of treatment. Under the same treatment regimens, the level of PrP gene expression was significantly down-regulated in cortical neuron cell cultures and cerebellar granule cell cultures and was up-regulated in astrocyte cultures. The altered PrP gene expression occurred as early as 3 days after the treatment. After 10 days of treatment, while the cultured cortical neurons underwent further apoptosis, their expression of PrP gene started to recover gradually. These findings indicate that PrP 106–126 regulates transcription of the PrP gene and this activity is associated with its neurotoxicity in primary rat neuronal cultures. [ABSTRACT FROM AUTHOR]

Abstract The open reading frame of peacock and parakeet prion protein (PrP) genes was cloned and sequenced. The peacock and parakeet PrP genes consisted of 833 and 866 nucleotides encoding 266 and 277 amino acids, respectively (GenBank Accession numbers AY365065 and AY365066). Sequence analysis showed that the peacock and parakeet PrP genes had 93.67% homology to each other, 94.04% and 99.64% homology to the chicken PrP gene and 46.0% and 42.1% similarity to the mammalian PrP genes, respectively. The structural features of all known mammalian and avian PrPs, including N-terminal signal peptides, tandem repeats, conserved hydrophobic region, disulfide bridges and glycoinositol phospholipid anchor, were also found in peacock and parakeet PrPs. The parakeet and peacock PrPs, however, differed in the hexarepeat region, with the peacock having six and the parakeet having seven hexarepeats. The phylogenetic analysis showed that the PrP genes in 52 species were clustered into 2 distinct lineages, the avian and the mammalian. The peacock and parakeet PrP genes belonged to the same lineage but the peacock PrP was sub-classed with the pigeon PrP and the parakeet PrP was sub-classed with the duck and chicken PrPs. The present work added two more species data to the collection of the PrP genes and supported the previous findings that the PrP genes are highly conserved across species. [ABSTRACT FROM AUTHOR]

Investigates the participation of galanin in pain processing at the spinal level. Implications of the upregulation of galanin in dorsal root ganglia neurones following nerve injury; Impact of inflammation on GAL1 and GAL2 receptor; Value of GAL1 receptor for the treatment of neuropathic pain.

Susceptibility to natural scrapie in sheep is associated with polymorphisms at codons 136, 154 and 171 of the prion protein (PrP) gene. To assess the risk of scrapie in sheep raised in China, DNA from 30 sheep of two breeds was isolated, amplified and sequenced for the PrP gene. The ovine PrP gene was found to be highly homogenous. The genotype associated with high susceptibility to scrapie (VRQ) was absent, whereas that associated with the resistance (ARR) was present in 6.7% of sheep examined. ARK was also rare (6.7%). ARQ that is associated with an intermediate susceptibility was the genotype observed in the most of sheep examined (86.6%). These data suggest that Chinese sheep of Mongolian sheep breed are susceptible to scrapie. [ABSTRACT FROM AUTHOR]