Development of the microcirculatory bed of the human tongue in the prenatal period

Morphofunctional regularities of formation and development of the blood microcirculatory bed in the human tongue have been studied in the prenatal period of morphogenesis. 119 human embryos and fetuses at the age of 5 weeks--9 months have been investigated. A complex of methods have been used: common histological (hematoxylin--eosin, after van Gieson and Mallory), injection of the lingual vessels with 20% suspension of Indian ink--gelatin, transmissive electron microscopy. General regularities of organogenesis, stages of the blood microcirculatory bed development and peculiarities of the process on formation of the primary protocapillary lingual blood bed are revealed. Regularities in structure of the terminal vascular constructions are studied for each structural element of the organ--mucosal membrane, muscles, glands, lingual tonsil. For these elements at the ultrastructural level certain features of the organic specificity in the structure of the blood microcirculatory bed links are determined.     

Structure of the neuromuscular spindles in the tongue of human fetuses

The dynamics in development of some components--of the neuromuscular spindles in the human fetus and newborn tongues have been studied by means of certain general and neurohistological methods with elements of morphometry. During the whole prenatal period of the human life, there is a certain synchronism in the development of the lingual proper muscles and the neuro-muscular spindles. Certain integration in the development of the neuro-muscular spindles is observed in 4-6-month-old fetuses; in 8-9-month-old fetuses and in newborns it is substituted for heterochronicity. By the time of birth, the muscle spindle contractile elements are supplied with a more differentiated efferent innervation. The latter actively effects the morphological state of the intrafusal muscle fibers and forms a base for functional activity of the tongue.     

Nucleotide sequence and phylogenetic analysis of long terminal repeats of human endogenous retrovirus K family (HERV-K) on human chromosomes

It has been suggested that human endogenous retroviruses K family (HERV-K) has a role in disease, and solitary long terminal repeats (LTRs) of HERV-K have been potentially capable of affecting the expression of closely located genes. Using the human monochromosomes 8, 9, 17, and 18, with specific PCR primers, we identified thirty-four sequences of new HERV-K LTRs. Those LTR elements were analyzed phylogenetically with the human-specific HERV-K LTRs using neighbor-joining and maximum parsimony methods. Clones HKL8-5, HKL9-5, and HKL9-8 are related by more than 99% homology with the human-specific HERV-K LTRs. The HKL9-5 clone on chromosome 9 was 100% identical with the sequences of human-specific LTR, AC002400, on chromosome 16. The findings suggest that there has been recent proliferation, transposition, or chromosomal translocation of HERV-K LTR elements on human chromosomes.     

Comparative genomics of the SOX9 region in human and Fugu rubripes: conservation of short regulatory sequence elements within large intergenic regions.

Campomelic dysplasia (CD), a human skeletal malformation syndrome with XY sex reversal, is caused by heterozygous mutations in and around the gene SOX9. SOX9 has an extended 5' control region, as indicated by CD translocation breakpoints scattered over 1 Mb proximal to SOX9 and by expression data from mice transgenic for human SOX9-spanning yeast artificial chromosomes. To identify long-range regulatory elements within the SOX9 5' control region, we compared approximately 3.7 Mb and 195 kb of sequence around human and Fugu rubripes SOX9, respectively. We identified only seven and five protein-coding genes in the human and F. rubripes sequences, respectively. Four of the F. rubripes genes have been mapped in humans; all reside on chromosome 17 but show extensive intrachromosomal gene shuffling compared with the gene order in F. rubripes. In both species, very large intergenic distances separate SOX9 from its directly flanking genes: 2 Mb and 500 kb on either side of SOX9 in humans, and 68 and 97 kb on either side of SOX9 in F. rubripes. Comparative sequence analysis of the intergenic regions revealed five conserved elements, E1-E5, up to 290 kb 5' to human SOX9 and up to 18 kb 5' to F. rubripes SOX9, and three such elements, E6-E8, 3' to SOX9. Where available, mouse sequences confirm conservation of the elements. From the yeast artificial chromosome transgenic data, elements E3-E5 are candidate enhancers for SOX9 expression in limb and vertebral column, and 8 of 10 CD translocation breakpoints separate these elements from SOX9.     

Olfactory-like receptor cDNAs are present in human lingual cDNA libraries

Olfactory and pheromone receptors (ORs) constitute a large family of G-protein-coupled receptors involved in the detection and transduction of odorant signals. Using degenerated primers complementary to the highly conserved transmembrane domains II, III, VI, and VII within this protein family, Gaudin et al. have recently described the expression of several OR genes in foetal human tongue. Among the nine genes identified in human foetal tongue (HTPCR06, HGMP07I, JCG6, TPCR85, JCGI1, JCG2, JCG3, JCG5, and JCG9), only four (HTPCR06, HGMP07I, JCG3, and JCG5) were found to be expressed in adult tongue, suggesting that ORs might perform developmental functions in this organ. The objective of our work was to obtain additional information about the expression of olfactory-like genes in human tongue. In the present study, the synthesis and the screening of a cDNA library from epithelial cells of human adult tongue is reported. Two kinds of PCR analysis were performed. First, partial olfactory-like receptor cDNAs amplified with the degenerated primers used by Gaudin et al. were cloned and described. Second, a comparison of the expression profiles of the olfactory-like receptor genes previously identified before was carried out using specific primers. Among the genes studied we found that four genes (HTPCR06, JCG3, JCG5, and JCG6) are expressed in epithelial cells of the surface of the adult tongue. Additionally, we show that three olfactory-like receptor genes OR7A5/HTPCR2, OR6Q1, and OR7C1/TPCR86 are also expressed in these cells.     

Visualizing Taste Papillae In Vivo with Scanning Electron Microscopy of a High Resolution Cast

A method using polyvinylsiloxane (PVS), a high-resolution dentalimpression material, to obtain negative images of lingual surfacesis described. Epoxy-resin tongue replicas made from these impressionswere examined with scanning electron microscopy (SEM). Thismethod has been developed to visualize structural details ofthe tongue surface of living human beings and laboratory animals.The utility of the method is demonstrated with hamster tongues,which have well-defined fungiform papillae with single tastepores, and human tongues, which have more variable surface structures.Replicas made from PVS impressions of tongues of living hamsterswere compared with the same tongues after fixation. The replicascontained much of the detail present in fixed tongues. WithSEM, it was possible to identify individual fungiform papillae,which contained depressions with the size and the location ofhamster taste pores. Individual papillae could also be recognizedin human-tongue replicas, but taste pores could not be identifiedwith certainty. These replicas provide permanent, three-dimensionalrecords of tongue topography that could be used to documentchanges due to trauma, disease and aging.     

The bioelectronic nose and tongue using olfactory and taste receptors: Analytical tools for food quality and safety assessment

Food intake is the primary method for obtaining energy and component materials in the human being. Humans evaluate the quality of food by combining various facets of information, such as an item of food's appearance, smell, taste, and texture in the mouth. Recently, bioelectronic noses and tongues have been reported that use human olfactory and taste receptors as primary recognition elements, and nanoelectronics as secondary signal transducers. Bioelectronic sensors that mimic human olfaction and gustation have sensitively and selectively detected odor and taste molecules from various food samples, and have been applied to food quality assessment. The portable and multiplexed bioelectronic nose and tongue are expected to be used as next-generation analytical tools for rapid on-site monitoring of food quality. In this review, we summarize recent progress in the bioelectronic nose and tongue using olfactory and taste receptors, and discuss the potential applications and future perspectives in the food industry.     

miR-9-5p靶向Ambra1促进舌癌细胞增殖

miRNAs在肿瘤中异常表达,且与肿瘤的发生发展密切相关。目前发现,miR-9-5p在肿瘤中可能发挥原癌或抑癌效应,功能尚未完全阐述清楚。本文拟探讨miR-9-5p在舌癌中的作用。前期研究中收集10例舌癌组织及配对的癌旁组织,实时荧光定量PCR技术检测后发现,miR-9-5p在舌癌组织中的表达量显著高于癌旁组织,且其在舌癌细胞中的表达量也明显高于正常舌上皮细胞。此外,在舌癌细胞Tca8113中过表达miR-9-5p显著增加细胞的增殖能力。生物信息学预测及双荧光素酶报告基因实验证实,miR-9-5p可直接结合在自噬/苄氯素1调节因子1（activating molecule in beclin1-regulated autophagy, Ambra1）的 3′-UTR区域,靶向抑制Ambra1表达。Western印迹结果证实过表达miR-9-5p降低Ambra1的表达,反之亦然。Ambra1在舌癌细胞中的表达量显著低于正常舌上皮细胞。BrdU实验证实在舌癌细胞SCC-25中过表达Ambra1可显著抑制其增殖能力;相反,使用siRNA技术沉默Ambra1能够显著促进Tca8113细胞的增殖。在干预miR-9-5p的细胞中同时干预Ambra1的表达,结果发现Ambra1可显著逆转miR-9-5p对舌癌细胞增殖的促进作用。总之,miR-9-5p在舌癌中可能发挥原癌基因样作用,通过直接靶向抑制Ambra1表达进而促进舌癌细胞发生增殖。     

长链非编码RNA SNHG7靶向调控miR-9-5p参与舌癌进程

目前发现长链非编码RNA（long non-coding RNA, lncRNA）小核仁RNA宿主基因7 (small nucleolar RNA host gene 7, SNHG7)在多种肿瘤中高表达,发挥原癌基因效应,但是其在舌癌中的功能尚未研究。qRT-PCR结果证实,SNHG7在舌癌组织和细胞中均下调。在舌癌细胞中,过表达SNHG7抑制舌癌细胞增殖,敲低SNHG7促进舌癌细胞增殖。生物信息学分析及双荧光素酶报告基因实验证实,miR-9-5p与SNHG7结合且下调其表达。过表达SNHG7,miR-9-5p表达量降低而自噬/苄氯素1调节因子1（autophagy/Beclin 1 regulator 1, Ambra1）的表达增加。敲低SNHG7,上调miR-9-5p,且降低Ambra1的表达。临床组织标本随访资料统计发现,SNHG7、Ambra1与舌癌患者预后正相关,而miR-9-5p与舌癌患者预后负相关。提示SNHG7/miR-9-5p/Ambra1可作为舌癌预后的潜在标志物。     

Filiform papillae of human, rat and swine tongue

In order to study the structure of filiform papillae (FP), tissue specimens were taken from the anterior part of the tongues of 8 humans, 8 rats and 8 swine. The formalin-fixed samples were processed routinely for scanning electron microscopy (SEM) and light microscopy. With SEM, FP of human tongue contained 5-12 hairs which were covered with a massive plaque of micro-organisms. FP of rat tongue, on the other hand, contained one papillary projection with smooth surface structure. Colonization of micro-organisms was seen on the anterior part of the body of FP, but not on the hairs. In the cross-section of FP of the rat tongue, the cells of the papilla were close to each other and no micro-organisms were seen within the papillae. On the contrary, the spaces between the squamous epithelial cells of the hairs of human FP contained numerous micro-organisms. The structure of FP of the swine tongue resembled that of the rat tongue. The hairs were smooth, and some micro-organisms were seen on the cell surface of the interpapillary areas. The structure of FP is discussed from the standpoint of different keratinization and colonization of micro-organisms.     

Scanning Electron Microscopical Studies of Developing Gustatory Papillae in Humans

Development and morphological changes of human gustatory papillaeduring postovulatory weeks 6–15 have been studied usingscanning and transmission electron microscopy. The first papillaof the tongue appears around postovulatory week 6 in its caudalmidline near the foramen caecum. In contrast, the dorsal epitheliumof the anterior part of the tongue shows only small hillock-or papilla-like elevations from week 6 on, which comprise anaggregation of 5–20 epithelial cells. From week 7 on,most prominent fungiform papillae develop near the median sulcusand at the margins of the anterior part of the tongue. At theirtops, the first primitive taste pores are found around week10; these are often covered with processes of adjacent epithelialcells. Most pores, however, develop around weeks 14–15.The maturation of taste buds does not coincide with the appearanceof taste pores, since taste bud cells are not fully differentiatedin the observed period of time. Fungiform papillae are developedbefore filiform papillae, which do not occur within the first15 weeks of gestation. Fungiform papillae tend to grow betweenweeks 8 and 15 of gestation, whereas the size of vallate papillaeseems to be constant during this period. Chem. Senses 22: 601–612,1997.     

Endocytic Trafficking of Nanoparticles Delivered by Cell-penetrating Peptides Comprised of Nona-arginine and a Penetration Accelerating Sequence

Cell-penetrating peptides (CPPs) can traverse cellular membranes and deliver biologically active molecules into cells. In this study, we demonstrate that CPPs comprised of nona-arginine (R9) and a penetration accelerating peptide sequence (Pas) that facilitates escape from endocytic lysosomes, denoted as PR9, greatly enhance the delivery of noncovalently associated quantum dots (QDs) into human A549 cells. Mechanistic studies, intracellular trafficking analysis and a functional gene assay reveal that endocytosis is the main route for intracellular delivery of PR9/QD complexes. Endocytic trafficking of PR9/QD complexes was monitored using both confocal and transmission electron microscopy (TEM). Zeta-potential and size analyses indicate the importance of electrostatic forces in the interaction of PR9/QD complexes with plasma membranes. Circular dichroism (CD) spectroscopy reveals that the secondary structural elements of PR9 have similar conformations in aqueous buffer at pH 7 and 5. This study of nontoxic PR9 provides a basis for the design of optimized cargo delivery that allows escape from endocytic vesicles.     

Tongue as a first-line immune organ?

The tongue is an organ strategically situated at the beginning of the gastrointestinal(Gl)system,yet it has been remarkably understudied.Not only there is no separate subspecialty dedicated to the tongue,it is even excluded from 27 human organs/tissues thoroughly archived in the NCBI gene expression database.Almost none of my physician colleagues in Western medicine have paid attention to it,except a few who study tongue cancer.The tongue is typically described as a muscular organ important for taste,mastication,speech and sensation.Other than its development,anatomy/gross structural analyses and taste function(for recent reviews,see Roper and Chaudhari,2017),the human tongue is poorly studied in Western medicine,in particular,in terms of its roles in systemic diseases.In traditional Chinese medicine(TCM),however,the tongue holds a special place.Assessing the“tongue coating”,"tongue body”and morphological features is one of the most critical skills that TCM doctors have relied on for disease diagnoses for thousands of years before the advent of Western Medicine.     

Presence and phylogenetic analysis of HERV-K LTR on human X and Y chromosomes: evidence for recent proliferation

The K group of human endogenous retroviruses (HERV-K) has been suggested to have a role in disease and has recently been shown to include long terminal repeat (LTR) elements that are human specific. Here we investigated the presence of HERV-K LTRs on the human X and Y chromosomes with the use of PCR on a monochromosomal somatic cell hybrid DNA panel. We report twelve such sequences on the X chromosome and ten sequences on the Y chromosome. Phylogenetic analysis reveals that clones X2, 4, 5, 6, 7, 11, 15 from the X chromosome and clones Y4, 5, 7, 10 from the Y chromosome are closely related to the human-specific members of Medstrand and Mager's cluster 9. The sequence of clone Y7 from the Y chromosome is identical with human-specific HERV-K LTR element (AC002350) from chromosome 12q24. The findings suggest recent proliferation and transposition of HERV-K LTR elements on these chromosomes. Such events may have contributed to structural change and genetic variation in the human genome. We draw attention to evolutionarily recent changes in homologies between X and Y chromosomes as a method of further investigating such transpositions.     

Optical and scanning electron microscopy observation of the mucosa of human fetal tongue

The structural features of the human foetal tongue have been studied in foetuses from 8th to 20th week of pregnancy. The characteristics of the developing papillae as well as of epithelial and mesenchymal layers have been pointed out. An early differentiation of the mesenchymal tissue has been observed, concerning phenomena of cellular condensation and reticular fibers organization both in superficial and deep layers. The hypothesis of the existence of straight interactions between epithelium and mesenchyme also in the developing human tongue mucosa has been suggested. Also the observations at SEM demonstrate that from the 8th to the 20th week the epithelial surface of the tongue reaches a stable structural pattern. From 11th week a characteristic cellular polymorphism occurs: cells with microvilli that diminish progressively, ciliated cells that disappear almost completely at the 20th week and cells whose free surface show microplicae, definitive stage of the tongue cell evolution.     

Culture of endodermal stem/progenitor cells of the mouse tongue

The tongue represents a very accessible source of tissue-specific epithelial stem cells of endodermal origin. However, little is known about the properties of these cells and the mechanisms regulating their proliferation and differentiation. Foxa2, an endodermal marker, is expressed throughout the tongue epithelium during embryonic development but becomes confined to a minority of basal cells and some taste bud sensory cells in the adult tongue. Using a previously described line of transgenic mice in which enhanced green fluorescent protein (eGFP) is expressed under the control of a human keratin 5 promoter region (Krt5-eGFP), we have isolated a subpopulation of cells in the basal epithelial layer of the mouse tongue with a high efficiency of generating holoclones of undifferentiated cells in culture with a feeder layer. Krt5-GFP(hi) cells can both self renew and give rise to differentiated stratified keratinized epithelial cells when cultured on an air-liquid interface.     

Biosynthesis of coenzyme Q in eukaryotes

Coenzyme Q (CoQ) is a component of the electron transport chain that participates in aerobic cellular respiration to produce ATP. In addition, CoQ acts as an electron acceptor in several enzymatic reactions involving oxidation–reduction. Biosynthesis of CoQ has been investigated mainly in Escherichia coli and Saccharomyces cerevisiae, and the findings have been extended to various higher organisms, including plants and humans. Analyses in yeast have contributed greatly to current understanding of human diseases related to CoQ biosynthesis. To date, human genetic disorders related to mutations in eight COQ biosynthetic genes have been reported. In addition, the crystal structures of a number of proteins involved in CoQ synthesis have been solved, including those of IspB, UbiA, UbiD, UbiX, UbiI, Alr8543 (Coq4 homolog), Coq5, ADCK3, and COQ9. Over the last decade, knowledge of CoQ biosynthesis has accumulated, and striking advances in related human genetic disorders and the crystal structure of proteins required for CoQ synthesis have been made. This review focuses on the biosynthesis of CoQ in eukaryotes, with some comparisons to the process in prokaryotes.     

Enrichment for histone H3 lysine 9 methylation at Alu repeats in human cells

The aim of this study was to identify in human cells common targets of histone H3 lysine 9 (H3-Lys9) methylation, a modification that is generally associated with gene silencing. After chromatin immunoprecipitation using an H3-Lys9 methylated antibody, we cloned the recovered DNA and sequenced 47 independent clones. Of these, 38 clones (81%) contained repetitive elements, either short interspersed transposable element (SINE or Alu elements), long terminal repeat (LTR), long interspersed transposable element (LINE), or satellite region (ALR/Alpha) DNA, and three additional clones were near Alu elements. Further characterization of these repetitive elements revealed that 32 clones (68%) were Alu repeats, corresponding to both old Alu (23 clones) and young Alu (9 clones) subfamilies. Association of H3-Lys9 methylation was confirmed by chromatin immunoprecipitation-PCR using conserved Alu primers. In addition, we randomly selected 5 Alu repeats from the recovered clones and confirmed association with H3-Lys9 by PCR using primer sets flanking the Alu elements. Treatment with the DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine rapidly decreased the level of H3-Lys9 methylation in the Alu elements, suggesting that H3-Lys9 methylation may be related to the suppression of Alu elements through DNA methylation. Thus H3-Lys9 methylation is enriched at human repetitive elements, particularly Alu elements, and may play a role in the suppression of recombination by these elements.