Morphometric and immunocytochemical assessment of fungiform taste buds after interruption of the chorda-lingual nerve

Unilateral interruption of the chorda-lingual nerve led to a loss of most epithelial axons and to the deterioration of fungiform taste buds in the anterior portion of the tongue of albino rats, mongolian gerbils, and golden hamsters. By three weeks after surgery the following percentages of fungiform taste buds had completely disappeared: 71% in gerbils, 28% in rats, and 26% in hamsters. Residual taste buds were classified into two groups: atrophic taste buds and taste bud remnants. Atrophic taste buds were smaller than normal and typically had no visible taste pore, although they retained the characteristic oval shape of a taste bud and numerous elongated cells. Taste bud remnants were non-oval fragments of taste buds with few elongated cells. Specific markers for elongated taste cells (monoclonal antibodies to keratin 19) confirmed that atrophic taste buds, as well as some taste bud remnants, had elongated taste cells. By 180 days after chorda-lingual nerve transection, 44% of rat fungiform taste buds had disappeared; morphometric analysis of the 311 residual taste buds established that 241 atrophic taste buds and 69 taste bud remnants were, respectively, 50% and 75% smaller than the average volume of 480 normal taste buds. The aggregate loss of gustatory tissue, calculated from the shrinkage of residual taste buds and the volume lost by the outright disappearance of many taste buds, was 88% for gerbils, 72% for rats, and 65% for hamsters. Evaluation in gerbils of the co-occurrence of taste buds and axons suggests residual taste buds were neurotrophically supported. Every gerbil fungiform papilla that lacked axons lacked a taste bud. Every fungiform papillae that had a residual taste bud had axons; axons were absent from 22% of empty fungiform papillae. Diminished numbers of gustatory neurotrophic axons could account for both the loss of fungiform taste buds and the reduced volume of residual taste buds. © 1993 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50421/1/1070260302_ftp.pd

Developmental time course of peripheral cross‐modal sensory interaction of the trigeminal and gustatory systems

Few sensory modalities appear to engage in cross‐modal interactions within the peripheral nervous system, making the integrated relationship between the peripheral gustatory and trigeminal systems an ideal model for investigating cross‐sensory support. The present study examined taste system anatomy following unilateral transection of the trigeminal lingual nerve (LX) while leaving the gustatory chorda tympani intact. At 10, 25, or 65 days of age, rats underwent LX with outcomes assessed following various survival times. Fungiform papillae were classified by morphological feature using surface analysis. Taste bud volumes were calculated from histological sections of the anterior tongue. Differences in papillae morphology were evident by 2 days post‐transection of P10 rats and by 8 days post in P25 rats. When transected at P65, animals never exhibited statistically significant morphological changes. After LX at P10, fewer taste buds were present on the transected side following 16 and 24 days survival time and remaining taste buds were smaller than on the intact side. In P25 and P65 animals, taste bud volumes were reduced on the denervated side by 8 and 16 days postsurgery, respectively. By 50 days post‐transection, taste buds of P10 animals had not recovered in size; however, all observed changes in papillae morphology and taste buds subsided in P25 and P65 rats. Results indicate that LX impacts taste receptor cells and alters epithelial morphology of fungiform papillae, particularly during early development. These findings highlight dual roles for the lingual nerve in the maintenance of both gustatory and non‐gustatory tissues on the anterior tongue. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 626–641, 201

Differential diagnosis of tuberculous meningitis from partially-treated pyogenic meningitis by cell ELISA

BACKGROUND: Tuberculous meningitis (TBM) is a major global health problem, and it is sometimes difficult to perform a differential diagnosis of this disease from other diseases, particularly partially-treated pyogenic meningitis (PTPM). In an earlier study, we demonstrated the presence of a 30-kD protein antigen in cerebrospinal fluid (CSF) of TBM patients. We have also shown that lymphocytes from CSF of TBM patients respond differently to this antigen than do those from PTPM patients. The purpose of this study was to develop an assay that can discriminate between TBM and PTPM. METHODS: We developed a cell enzyme-linked immunosorbant assay (Cell ELISA) to quantitatively measure production of antibodies against the 30-kD protein in B cells from CSF of TBM and PTPM patients. RESULTS: The cell ELISA yielded 92% (11/12) sensitivity and 92% (11/12) specificity for the differential diagnosis of TBM from PTPM. CONCLUSION: When induced with the 30-kD protein antigen, B cells derived from CSF of TBM patients respond to IgG production within 24 h while those derived from PTPM patients do not respond

Expression and Regulation of Latent TGF-β Binding Protein-1 Transcripts and Their Splice Variants in Human Glomerular Endothelial Cells

Latent transforming growth factor (TGF)-β-binding protein (LTBP) is required for the assembly, secretion, matrix association, and activation of latent TGF-β complex. To elucidate the cell specific expression of the genes of LTBP-1 and their splice variants and the factors that regulate the gene expression, we cultured primary human glomerular endothelial cells (HGEC) under different conditions. Basal expression of LTBP-1 mRNA was suppressed in HGEC compared to WI-38 human embryonic lung fibroblasts. High glucose, H2O2, and TGF-β1 upregulated and vascular endothelial growth factor (VEGF) further downregulated LTBP-1 mRNA in HGEC. RT-PCR with a primer set for LTBP-1S produced many clones but no clone was gained with a primer set for LTBP-1L. Of 12 clones selected randomly, Sca I mapping and DNA sequencing revealed that only one was LTBP-1S and all the others were LTBP-1SΔ53. TGF-β1, but not high glucose, H2O2 or VEGF, tended to increase LTBP-1SΔ53 mRNA. In conclusion, HGEC express LTBP-1 mRNA which is suppressed at basal state but upregulated by high glucose, H2O2, and TGF-β1 and downregulated by VEGF. Major splice variant of LTBP-1 in HGEC was LTBP-1SΔ53. Modification of LTBP-1SΔ53 gene in HGEC may abrogate fibrotic action of TGF-β1 but this requires confirmation

Light-evoked Somatosensory Perception of Transgenic Rats That Express Channelrhodopsin-2 in Dorsal Root Ganglion Cells

In vertebrate somatosensory systems, each mode of touch-pressure, temperature or pain is sensed by sensory endings of different dorsal root ganglion (DRG) neurons, which conducted to the specific cortical loci as nerve impulses. Therefore, direct electrical stimulation of the peripheral nerve endings causes an erroneous sensation to be conducted by the nerve. We have recently generated several transgenic lines of rat in which channelrhodopsin-2 (ChR2) transgene is driven by the Thy-1.2 promoter. In one of them, W-TChR2V4, some neurons were endowed with photosensitivity by the introduction of the ChR2 gene, coding an algal photoreceptor molecule. The DRG neurons expressing ChR2 were immunohistochemically identified using specific antibodies to the markers of mechanoreceptive or nociceptive neurons. Their peripheral nerve endings in the plantar skin as well as the central endings in the spinal cord were also examined. We identified that ChR2 is expressed in a certain population of large neurons in the DRG of W-TChR2V4. On the basis of their morphology and molecular markers, these neurons were classified as mechanoreceptive but not nociceptive. ChR2 was also distributed in their peripheral sensory nerve endings, some of which were closely associated with CK20-positive cells to form Merkel cell-neurite complexes or with S-100-positive cells to form structures like Meissner's corpuscles. These nerve endings are thus suggested to be involved in the sensing of touch. Each W-TChR2V4 rat showed a sensory-evoked behavior in response to blue LED flashes on the plantar skin. It is thus suggested that each rat acquired an unusual sensory modality of sensing blue light through the skin as touch-pressure. This light-evoked somatosensory perception should facilitate study of how the complex tactile sense emerges in the brain

Insulin-like growth factor binding protein 5 enhances survival of LX2 human hepatic stellate cells

ABSTRACT: BACKGROUND: Expression of insulin-like growth factor binding protein 5 (IGFBP5) is strongly induced upon activation of hepatic stellate cells and their transdifferentiation into myofibroblasts in vitro. This was confirmed in vivo in an animal model of liver fibrosis. Since IGFBP5 has been shown to promote fibrosis in other tissues, the aim of this study was to investigate its role in the progression of liver fibrosis. METHODS: The effect of IGFBP5 was studied in LX2 cells, a model for partially activated hepatic stellate cells, and in human primary liver myofibroblasts. IGFBP5 signalling was modulated by the addition of recombinant protein, by lentiviral overexpression, and by siRNA mediated silencing. Furthermore, the addition of IGF1 and silencing of the IGF1R was used to investigate the role of the IGF-axis in IGFBP5 mediated effects. RESULTS: IGFBP5 enhanced the survival of LX2 cells and myofibroblasts via a >50% suppression of apoptosis. This effect of IGFBP5 was not modulated by the addition of IGF1, nor by silencing of the IGF1R. Additionally, IGFBP5 was able to enhance the expression of established pro-fibrotic markers, such as collagen Ialpha1, TIMP1 and MMP1. CONCLUSION: IGFBP5 enhances the survival of (partially) activated hepatic stellate cells and myofibroblasts by lowering apoptosis via an IGF1-independent mechanism, and enhances the expression of profibrotic genes. Its lowered expression may, therefore, reduce the progression of liver fibrosi

Expression of ECM proteins fibulin-1 and -2 in acute and chronic liver disease and in cultured rat liver cells

Fibulin-2 has previously been considered as a marker to distinguish rat liver myofibroblasts from hepatic stellate cells. The function of other fibulins in acute or chronic liver damage has not yet been investigated. The aim of this study has been to evaluate the expression of fibulin-1 and -2 in models of rat liver injury and in human liver cirrhosis. Their cellular sources have also been investigated. In normal rat liver, fibulin-1 and -2 were both mainly present in the portal field. Fibulin-1-coding transcripts were detected in total RNA of normal rat liver, whereas fibulin-2 mRNA was only detected by sensitive, real-time quantitative polymerase chain reaction. In acute liver injury, the expression of fibulin-1 was significantly increased (17.23-fold after 48 h), whereas that of fibulin-2 was not modified. The expression of both fibulin-1 and -2 was increased in experimental rat liver cirrhosis (19.16- and 26.47-fold, respectively). At the cellular level, fibulin-1 was detectable in hepatocytes, “activated” hepatic stellate cells, and liver myofibroblasts (2.71-, 122.65-, and 469.48-fold over the expression in normal rat liver), whereas fibulin-2 was restricted to liver myofibroblasts and was regulated by transforming growth factor beta-1 (TGF-β1) in 2-day-old hepatocyte cultures and in liver myofibroblasts. Thus, fibulin-1 and -2 respond differentially to single and repeated damaging noxae, and their expression is differently present in liver cells. Expression of the fibulin-2 gene is regulated by TGF-β1 in liver myofibroblasts

Hepatitis C virus NS5A-regulated gene expression and signaling revealed via microarray and comparative promoter analyses

Most individuals exposed to hepatitis C virus (HCV) become chronically infected and are predisposed to liver disease. The mechanisms underlying viral persistence and disease progression are unknown. A role for the HCV NS5A protein in viral replication and interferon resistance has been demonstrated. To identify mechanisms affected by NS5A, we analyzed the gene expression of Huh7 cells expressing NS5A and control cells using oligonucleotide microarrays. A set of 103 genes (43 up-regulated, 60 down-regulated) whose expression was modified by at least twofold was selected. These included genes involved in cell adhesion and motility, calcium homeostasis, lipid transport and metabolism, and genes regulating immune responses. The finding of modulated expression of genes related to the TGF-Β superfamily and liver fibrosis was observed. Interestingly, both the tumor necrosis factor and lymphotoxin beta receptors were down-regulated by NS5A. Similar data were obtained following expression of four NS5A mutants obtained from patients who were not responsive or were sensitive to interferon therapy. Through computational analysis, we determined that 39 of the 43 genes up-regulated by NS5A contained one or more nuclear factor ΚB (NF-ΚB) binding sites within their promoter region. Using the Gibbs sampling method, we also detected enrichment of NF-ΚB consensus binding sites in the upstream regions of the 43 coexpressed genes. Activation of NF-ΚB by NS5A was subsequently demonstrated in luciferase reporter assays. Adenovirus-mediated expression of IΚBΑ reverted NS5A mediated up-regulation of gene expression. In conclusion , this study suggests a role of NS5A and NF-ΚB in HCV pathogenesis and related liver disease. Supplementary material for this article can be found on the H EPATOLOGY website ( http://interscience.wiley.com/jpages/0270-9139/suppmat/index.html ). (H EPATOLOGY 2004;40:708–718.)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34800/1/20371_ftp.pd