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1.
Article in Chinese | WPRIM | ID: wpr-935903

ABSTRACT

Golgi protein 73 (GP73) is a transmembrane protein on the Golgi apparatus and can be cut and released into the blood. In recent years, an increasing number of clinical studies have shown that the elevated serum GP73 level is closely related to liver diseases. And thus GP73 is expected to be used as a new serum marker for assessing progress of chronic liver diseases. Herein, the clinical application of serum GP73 in chronic hepatitis, liver fibrosis, liver cirrhosis and hepatocellular carcinoma with different etiologies was reviewed based on available literatures; and a research outlook in this field is made.


Subject(s)
Biomarkers , Carcinoma, Hepatocellular , Golgi Apparatus , Humans , Liver Cirrhosis , Liver Neoplasms
2.
Niger. j. paediatr ; 47(4): 298-304, 2020. ilus
Article in English | AIM | ID: biblio-1267473

ABSTRACT

Background: Hippocampus is a neural structure in the temporal lobe that plays a crucial role in learning and memory. Cognitive impairment with learning disabilities is a common feature in hydrocephalus and is more prominent in adult-onset hydrocephalus. The aim of this study is to describe the morphological alterations in the pyramidal cells of the hippocampus of adult hydrocephalic mice. Method: Hydrocephalus was induced in adult albino mice by intra-cisternal injection of kaolin suspension (250 mg/ml in sterile water). They were sacrificed 7, 14 and 21 days post-induction. Morphological analysis was carried out on hematoxylin and eosin stained coronal sections of the hippocampus: the pyramidal neurons (normal and pyknotic) in the CA1 and CA3 subregions were counted and the pyknotic index (PI) was calculated. The somatic and dendritic features of Golgi stained pyramidal neurons were examined by light microscopy in both hydrocephalic and control mice. Result: The PI was significantly greater in the CA1 region of the hippocampus in the hydrocephalic groups compared to the age matched controls. The dendritic processes of pyramidal neurons in the CA1 region were fewer with shorter terminal branches in the hydrocephalic mice than in controls; this was pronounced at 7 days post-induction. In the CA3 region, there was no difference in dendritic arborization between hydrocephalic and control mice. Conclusion: Acute adult-onset hydrocephalus was associated with increased pyknosis and reduced dendritic arborization in hippocampal pyramidal cells in the CA1 but not CA3 region


Subject(s)
Golgi Apparatus , Hydrocephalus , Pyramidal Cells
3.
Immune Network ; : e34-2019.
Article in English | WPRIM | ID: wpr-764026

ABSTRACT

Neutrophilic granule protein (NGP) was previously reported as a granular protein of neutrophils in mouse, but the function has not been known clearly. We found the presence of the possible signal peptide in NGP and validated this protein is circulating in the bloodstream. In our findings, NGP is being modified post-translationally in Golgi apparatus and endoplasmic reticulum, which is a universal character of secretory molecules with a signal peptide. The secreted NGP protein could be detected both in vitro and in vivo. NGP has sequence similarity with an antimicrobial protein cathelicidin, and we observed the aspect of inflammation of NGP. Interestingly, NGP interacts with the complex of LPS and LPS binding protein (LBP). This interaction blocks the binding of the complex of LPS and LBP to TLR4 and the downstream inflammatory signals. Furthermore, the inhibitory function of NGP against the inflammatory effect of LPS could be observed in both in vitro and in vivo. With these findings, we report NGP is a novel secretory protein to mask LPS and inhibit its function.


Subject(s)
Animals , Carrier Proteins , Cytokines , Endoplasmic Reticulum , Golgi Apparatus , In Vitro Techniques , Inflammation , Lipopolysaccharides , Masks , Mice , Neutrophils , Protein Binding , Protein Sorting Signals
4.
Cienc. tecnol. salud ; 6(1): 77-81, 2019. ^c27 cmilus
Article in Spanish | LILACS | ID: biblio-1025571

ABSTRACT

Los anticuerpos dirigidos contra el aparato de Golgi fueron inicialmente descritos en un paciente con Síndrome de Sjögren en 1982. Estos anticuerpos forman parte de los anticuerpos antinucleares y producen un patrón característico en las células Hep-2. Desde su descubrimiento no se ha logrado establecer ninguna asociación clara con alguna enfermedad autoinmune y/o manifestación clínica. En el presente artículo se reporta el primer caso de anticuerpos antinucleares por fluorescencia (Fana) positivo con un patrón polar/sugestivo de anti-Golgi en Guatemala encontrado en el Laboratorio de Inmunología-Autoinmunidad del Hospital Roosevelt en un paciente masculino con una uveítis en el ojo derecho y que presentó pruebas de laboratorio positivas para toxoplasma, rubeola IgG, citomegalovirus, y herpes 1 y 2. Este patrón ha sido encontrado en personas con diferentes enfermedades autoinmunes pero no se ha logrado establecer asociación con alguna enfermedad en particular.


The anti-Golgi complex antibodies were first described in a patient with Sjögren Syndrome in 1982. These antibodies are part of the antinuclear antibodies and they have a characteristic staining pattern in Hep-2 cells. They have not been associated with any autoimmune disease and/or clinical manifestation. In the present case we report the first nuclear antibodies (ANA) with a staining pattern polar/anti-Golgi-like founded in the Immunology-Autoimmunity Laboratory at Roosevelt Hospital in a male patient with an uveitis on the right eye and positive IgG serology for toxoplasma, rubella, cytomegalovirus and herpes 1 and 2. This pattern has been founded in patients with different autoimmune diseases, but they haven´t been associated with a disease.


Subject(s)
Humans , Male , Middle Aged , Uveitis/complications , Autoimmunity , Golgi Apparatus/microbiology , Rubella virus , Toxoplasma , Uveitis/microbiology , Visual Acuity , Cytomegalovirus
5.
Int. j. morphol ; 35(2): 435-441, June 2017. ilus
Article in English | LILACS | ID: biblio-893000

ABSTRACT

Tooth enamel is the hardest tissue in the body. The organic matrix configuration is provided by the main proteins amelogenin, ameloblastin and enamelysin (MMP20), an enzyme that helps to shape the matrix. The aim of this study was to determine by histochemistry the expression of amelogenin and enamelysin through the rough endoplasmic reticulum in the late stages of amelogenesis, and its expression in the Complexus golgiensis (Golgi complex / Golgi apparatus) in the early stages in human fetuses. In early stages a colocalization of both proteins inside the Golgi apparatus was found, being more evident the relationship between Golgi and amelogenin (99.92 %). In the late stage, a colocalization of both proteins and rugged endoplasmic reticulum was found. With enamelysin being more evident in relation with rough endoplasmic reticulum (99.95 %). Our findings demonstrated the presence of amelogenin and enamelysin in odontoblast and ameloblast. However, the presence of these two proteins in odontoblast remains unknown.


El esmalte dental es el tejido más duro del cuerpo. La configuración de la matriz orgánica es proporcionada por las proteínas principales amelogenina, ameloblastina y enamelisina (MMP20), una enzima que ayuda a dar forma a la matriz. El objetivo de este estudio fue determinar mediante histoquímica la expresión de amelogenina y enamelisina a través del retículo endoplasmático rugoso en las últimas etapas de la amelogénesis , y su expresión en el Complexo golgiensis en las primeras etapas de formación en fetos humanos. En las primeras etapas se observó colocalización de ambas proteínas en el interior del Complexo golgiensis, siendo más evidente la relación entre Golgi y amelogenina (99,92 %). En la última etapa, se identificó una colocalización de ambas proteínas y retículo endoplásmico rugoso. Resulto más evidente la enamelisina en relación con el retículo endoplasmático rugoso (99,95 %). Nuestros resultados demostraron la presencia de amelogenina y enamelisina en odontoblastos y ameloblastos, sin embargo se desconoce la presencia de estas dos proteínas en odontoblastos.


Subject(s)
Humans , Amelogenin/metabolism , Dental Enamel Proteins , Endoplasmic Reticulum, Rough , Golgi Apparatus , Matrix Metalloproteinase 20/metabolism , Amelogenesis , Fluorescent Antibody Technique
6.
Article in Korean | WPRIM | ID: wpr-194884

ABSTRACT

PURPOSE: To evaluate the histopathological changes of anterior capsule and lens epithelial cells in various types of cataract. METHODS: Patients scheduled for cataract surgery of phacoemulsification with intraocular lens implantation were enrolled in this study. Anterior capsule tissues sized 5 mm were obtained at the time of continuous curvilinear capsulorhexis during surgery. Histological examination of the obtained tissue was performed by transmission electron microscope. RESULTS: Nuclear cataract showed a uniform cuboidal monolayer of epithelial cells firmly attached to the anterior capsule. But, the mitochondria, Golgi apparatus, and endoplasmic reticulum were damaged and replaced with vacuoles. Anterior subcapsular cataract showed multilayers of epithelial cells with irregular intracellular structures. Epithelial cells of mature cataract were severely damaged and detached from the anterior capsule, accompanied by expansion of intra-cellular space and a large amount of vacuoles. Epithelial cells were irregular and severely damaged, and intracellular structures were hardly observed in traumatic cataract. Deposition of pseudoexfoliation materials on the anterior capsule was observed in pseudoexfoliation cataract. CONCLUSIONS: Changes in epithelial cells caused by fluid accumulation and electrolyte imbalance in the lens attributes more to cataract formation than do changes the in lens capsule.


Subject(s)
Capsulorhexis , Cataract , Endoplasmic Reticulum , Epithelial Cells , Golgi Apparatus , Humans , Lens Implantation, Intraocular , Mitochondria , Phacoemulsification , Vacuoles
7.
Article in English | WPRIM | ID: wpr-163183

ABSTRACT

Progressive cerebellar ataxias are rare diseases during childhood, especially under 6 years of age. In a single family, three affected siblings exhibited Friedreich's-ataxia-like phenotypes before 2 years of age. They had progressive cerebellar atrophy, intellectual disability, and scoliosis. Although their phenotypes were similar to those observed in patients with autosomal recessive cerebellar ataxias, other phenotypes (e.g., seizure, movement disorders, ophthalmologic disturbance, cardiomyopathy, and cutaneous disorders) were not noted in this family. Whole-exome sequencing of the family members revealed one potential heterozygous mutation (c.1209delG, NM_181733.2; p.Met403IlefsX3, NP_859422.2) of the gene encoding conserved oligomeric Golgi complex subunit 5 (COG5). The heterozygous deletion at the fifth base in exon 12 of COG5 caused a frameshift and premature stop. Western blotting of COG5 proteins in the skin tissues from an affected proband showed a significantly decreased level of full length COG5 and smaller, aberrant COG5 proteins. We reported a milder form of COG5 defect showing Friedreich's-ataxia-like phenotypes without hypotonia, microcephaly, and short stature that were observed in most patients with COG5 defect.


Subject(s)
Atrophy , Blotting, Western , Cardiomyopathies , Cerebellar Ataxia , Child , Exons , Golgi Apparatus , Humans , Intellectual Disability , Microcephaly , Movement Disorders , Muscle Hypotonia , Phenotype , Rare Diseases , Scoliosis , Seizures , Siblings , Skin
8.
Article in English | WPRIM | ID: wpr-148743

ABSTRACT

Osteopontin (OPN) is a secretory protein that plays an important role in urinary stone formation. Hydration status is associated with the development of urolithiasis. This study was conducted to examine the effects of dehydration and hydration on OPN expression in the rat kidney. Animals were divided into three groups, control, dehydrated, and hydrated. Kidney tissues were processed for light and electron microscope immunocytochemistry, in situ hybridization, and immunoblot analysis. Dehydration induced a significant increase in OPN protein expression, whereas increased fluid intake induced a decrease in protein expression. Under control conditions, OPN protein and mRNA expression were only detected in the descending thin limb (DTL). Dehydration induced increased expression in the DTL and the development of detectable expression in the thick ascending limb (TAL). In contrast, OPN expression levels declined to less than the controls in the DTL after hydration, while no expression of either protein or mRNA was detectable in the TAL. Immunoelectron microscopy demonstrated that hydration status altered tubular ultrastructure and intracellular OPN expression in the Golgi apparatus and secretory cytoplasmic vesicles. These data confirm that changes in oral fluid intake can regulate renal tubular epithelial cell OPN expression.


Subject(s)
Animals , Control Groups , Cytoplasmic Vesicles , Dehydration , Epithelial Cells , Extremities , Golgi Apparatus , Immunohistochemistry , In Situ Hybridization , Kidney , Microscopy, Immunoelectron , Osteopontin , Rats , RNA, Messenger , Urinary Calculi , Urolithiasis
9.
Article in Chinese | WPRIM | ID: wpr-286867

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the effect of docosahexaenoic acid (DHA) on invasiveness of aflatoxin B1 (AFB1)-induced hepatocellular carcinoma cells in vitro.</p><p><b>METHODS</b>HepG2.2.15 cells were exposed to different concentrations of AFB1 and DHA plus AFB1. The cell migration and invasion were assessed using wound-healing and Transwell assay, and flow cytometry was used to analyze the cell cycle changes. The ultrastructural changes of the cells were observed by transmission electron microscopy.</p><p><b>RESULTS</b>Compared with the control group, the cells exposed to2 µmol/L AFB1 showed obviously enhanced migration and invasion with decreased cell ratio in G1/G1 phase and increased cell ratio in G2/M phase but no changes in S phase cells; transmission electron microscopy revealed the presence of multiple nucleoli and significantly increased mitochondria and Golgi apparatus in the exposed cells. Compared with AFB1-exposed cells, the cells treated with DHA and AFB1 showed decreased migration and invasion abilities, and the G1/G1 phase cells increased and G2/M phase cells decreased significantly; ultrastructurally, the cells contained single nucleoli with decreased mitochondria and vacuolization occurred in the cytoplasm.</p><p><b>CONCLUSION</b>DHA can significantly inhibit AFB1-induced enhancement of cell migration and invasion in hepatocellular carcinoma cells in vitro.</p>


Subject(s)
Aflatoxin B1 , Pharmacology , Carcinoma, Hepatocellular , Pathology , Cell Cycle , Cell Movement , Docosahexaenoic Acids , Pharmacology , Golgi Apparatus , Hep G2 Cells , Humans , Liver Neoplasms , Pathology , Mitochondria , Neoplasm Invasiveness
10.
National Journal of Andrology ; (12): 72-76, 2016.
Article in Chinese | WPRIM | ID: wpr-304746

ABSTRACT

Spermiogenesis is a complex process of differentiation and morphologic alteration, in which sperm acrosome formation is an important stage. Acrosome is an essential component of the sperm head, which develops in four distinct phases: Golgi, cap, acro- somal, and maturation, each supported by precise and orderly regulation of various genes. The regulatory genes which act on Golgi ap- paratus include GOPC, Hrb, SPATA16, PICK1, and CK2α', those involved in the cap phase are Fads2, syntaxin 2, Kdm3a, and UBR7, and participating in acrosomal and maturation phases are KIFC1, Rnf19a, and DPY19L2. The abnormalities of these genes may affect male fertility by influencing the connection of the nuclear dense lamina and acroplaxome with the nuclear membrane and then the fusion and transportation of vesicles. This review focuses on the genes involved in different phases of acrosome formation.


Subject(s)
Acrosome , Physiology , Animals , Golgi Apparatus , Male , Mice , Sperm Head , Physiology , Spermatids , Spermatogenesis , Genetics , Spermatozoa
12.
Article in English | WPRIM | ID: wpr-186434

ABSTRACT

N-acetylglucosamine kinase (GlcNAc kinase or NAGK) is a ubiquitously expressed enzyme in mammalian cells. Recent studies have shown that NAGK has an essential structural, non-enzymatic role in the upregulation of dendritogenesis. In this study, we conducted yeast two-hybrid screening to search for NAGK-binding proteins and found a specific interaction between NAGK and dynein light-chain roadblock type 1 (DYNLRB1). Immunocytochemistry (ICC) on hippocampal neurons using antibodies against NAGK and DYNLRB1 or dynein heavy chain showed some colocalization, which was increased by treating the live cells with a crosslinker. A proximity ligation assay (PLA) of NAGK-dynein followed by tubulin ICC showed the localization of PLA signals on microtubule fibers at dendritic branch points. NAGK-dynein PLA combined with Golgi ICC showed the colocalization of PLA signals with somal Golgi facing the apical dendrite and with Golgi outposts in dendritic branch points and distensions. NAGK-Golgi PLA followed by tubulin or DYNLRB1 ICC showed that PLA signals colocalize with DYNLRB1 at dendritic branch points and at somal Golgi, indicating a tripartite interaction between NAGK, dynein and Golgi. Finally, the ectopic introduction of a small peptide derived from the C-terminal amino acids 74-96 of DYNLRB1 resulted in the stunting of hippocampal neuron dendrites in culture. Our data indicate that the NAGK-dynein-Golgi tripartite interaction at dendritic branch points functions to regulate dendritic growth and/or branching.


Subject(s)
Amino Acid Sequence , Animals , Cells, Cultured , Cytoplasmic Dyneins/chemistry , Dendrites/metabolism , Golgi Apparatus/metabolism , HEK293 Cells , Hippocampus , Humans , Molecular Sequence Data , Neurons/metabolism , Phosphotransferases (Alcohol Group Acceptor)/metabolism , Protein Interaction Maps , Rats, Sprague-Dawley , Tubulin
13.
Clinics ; 69(8): 554-558, 8/2014. tab, graf
Article in English | LILACS | ID: lil-718194

ABSTRACT

OBJECTIVE : The aim of the present study was to evaluate the effects of ovariectomy on the secretory apparatus of natriuretic peptides in right atrial cardiomyocytes. METHODS: Nine-month-old mice underwent bilateral ovariectomy or sham surgery. The blood exam of the ovariectomized mice showed results consistent with castrated females. Systolic blood pressure was measured after ovariectomy (9 mo of age) and at the moment of sacrifice (12 mo of age). Fragments of the right atrium were collected and prepared for electron microscopy examination. The following variables were quantified: the quantitative density and area of the natriuretic peptide granules, the relative volume of euchromatin in the nucleus, the number of pores per 10 μm of the nuclear membrane and the relative volumes of the mitochondria and Golgi complex. RESULTS: The cardiomyocytes obtained from ovariectomized mice indicated that the quantitative density and the area of secretory granules of natriuretic peptides were significantly lower compared with the sham-operated mice. Furthermore, there was a decrease in the relative volume of euchromatin, a lower density of nuclear pores, and lower relative volumes of the mitochondria and Golgi complex in the ovariectomized mice compared with the sham-operated mice. These findings suggest a pool with a low turnover rate, i.e., low synthesis and elimination of natriuretic peptides. CONCLUSION: A lack of estrogen caused hypotrophy of the secretory apparatus in right atrial cardiomyocytes that could explain the weak synthesis of natriuretic peptides in mice. Furthermore, one of the mechanisms of blood pressure control was lost, which may explain, in part, the elevated blood pressure in ovariectomized mice. .


Subject(s)
Animals , Female , Atrial Natriuretic Factor/drug effects , Myocytes, Cardiac/ultrastructure , Ovariectomy/adverse effects , Atrial Natriuretic Factor/analysis , Blood Pressure , Estradiol/blood , Estrogens/physiology , Euchromatin/ultrastructure , Golgi Apparatus/ultrastructure , Heart Atria/cytology , Mitochondrial Size , Models, Animal , Nuclear Pore/ultrastructure
14.
Acta Physiologica Sinica ; (6): 1-6, 2014.
Article in English | WPRIM | ID: wpr-297523

ABSTRACT

Vesicle-mediated transport of proteins is a highly regulated, multi-step process. When the vesicle is approaching its target membrane compartment, many factors are required to provide specificity and tethering between the incoming vesicle and the target membrane, before vesicle fusion can occur. Tethering factors, which include multisubunit complexes, coiled-coil proteins, with the help of small GTPases, provide the initial interaction between the vesicle and its target membrane. Of the multisubunit tethering factors, the transport protein particle (TRAPP) complexes function in a number of trafficking steps, including endoplasmic reticulum (ER)-to-Golgi transport, intra- and post-Golgi traffic and autophagosome formation. In this review, we summarize the updated progress in structure and function of TRAPP complexes as well as human diseases caused by genetic mutations in TRAPP.


Subject(s)
Animals , Endoplasmic Reticulum , Pathology , Physiology , Golgi Apparatus , Pathology , Physiology , Humans , Mutation , Protein Transport , Vesicular Transport Proteins , Genetics , Physiology
15.
Article in Chinese | WPRIM | ID: wpr-252603

ABSTRACT

Protein transport from endoplasmic reticulum (ER) to Golgi apparatus has long been known to be a central process for protein quality control and sorting. Recent studies have revealed that a large number of signal molecules are involved in regulation of membrane trafficking through ER, ER-Golgi intermediate compartment and Golgi apparatus. These molecules can significantly change the transport rate of proteins by regulating vesicle budding and fusion. Protein transport from ER to Golgi apparatus is not only controlled by signal pathways triggered from outside the cell, it is also regulated by feedback signals from the transport pathway.


Subject(s)
Endoplasmic Reticulum , Metabolism , Golgi Apparatus , Metabolism , Humans , Protein Transport , Physiology , Secretory Pathway , Signal Transduction
16.
Article in Chinese | WPRIM | ID: wpr-318078

ABSTRACT

<p><b>OBJECTIVE</b>To study the subcellular localization of severe fever with thrombocytopenia syndrome virus (SFTSV) in macrophages and understand the replication and assembly mechanism of SFTSV in host cells.</p><p><b>METHODS</b>Using two types of human macrophage cell lines THP-1 and U937, the study analyzed the intracellular colocalization of SFTSV with Golgi apparatus and endoplasmic reticulum by immunefluorescence staining and confocal microscopy.</p><p><b>RESULTS</b>SFTSV infected macrophage cell lines THP-1 and U937. Immunofluorescence staining showed that the SFTSV nuclear protein colocalized with Golgi apparatus and closely surrounded by endoplasmic reticulum in the perinuclear region.</p><p><b>CONCLUSION</b>The results suggested that Golgi complex and endoplasmic reticulum are probably the sites for formation and maturation of SFTSV viral particles.</p>


Subject(s)
Bunyaviridae , Cell Line, Tumor , Endoplasmic Reticulum , Virology , Fever , Virology , Golgi Apparatus , Virology , Humans , Macrophages , Virology , Thrombocytopenia , Virology
17.
Anatomy & Cell Biology ; : 1-16, 2012.
Article in English | WPRIM | ID: wpr-100678

ABSTRACT

A major advance in the understanding of the regulation of food intake has been the discovery of the adipokine leptin a hormone secreted by the adipose tissue. After crossing the blood-brain barrier, leptin reaches its main site of action at the level of the hypothalamic cells where it plays fundamental roles in the control of appetite and in the regulation of energy expenditure. At first considered as a hormone specific to the white adipose tissue, it was rapidly found to be expressed by other tissues. Among these, the gastric mucosa has been demonstrated to secrete large amounts of leptin. Secretion of leptin by the gastric chief cells was found to be an exocrine secretion. Leptin is secreted towards the gastric lumen into the gastric juice. We found that while secretion of leptin by the white adipose tissue is constitutive, secretion by the gastric cells is a regulated one responding very rapidly to secretory stimuli such as food intake. Exocrine-secreted leptin survives the hydrolytic conditions of the gastric juice by forming a complex with its soluble receptor. This soluble receptor is synthesized by the gastric cells and the leptin-leptin receptor complex gets formed at the level of the gastric chief cell secretory granules before being released into the gastric lumen. The leptin-leptin receptor upon resisting the hydrolytic conditions of the gastric juice is channelled, to the duodenum. Transmembrane leptin receptors expressed at the luminal membrane of the duodenal enterocytes interact with the luminal leptin. Leptin is actively transcytosed by the duodenal enterocytes. From the apical membrane it is transferred to the Golgi apparatus where it binds again its soluble receptor. The newly formed leptin-leptin receptor complex is then secreted baso-laterally into the intestinal mucosa to reach the blood capillaries and circulation thus reaching the hypothalamus where its action regulates food intake. Exocrine-secreted gastric leptin participates in the short term regulation of food intake independently from that secreted by the adipose tissue. Adipose tissue leptin on the other hand, regulates in the long term energy storage. Both tissues work in tandem to ensure management of food intake and energy expenditure.


Subject(s)
Adipokines , Adipose Tissue , Adipose Tissue, White , Appetite , Blood-Brain Barrier , Capillaries , Chief Cells, Gastric , Dietary Sucrose , Duodenum , Eating , Energy Metabolism , Enterocytes , Gastric Juice , Gastric Mucosa , Golgi Apparatus , Hand , Hypothalamus , Intestinal Mucosa , Leptin , Membranes , Phenobarbital , Receptors, Leptin , Secretory Vesicles
18.
Article in English | WPRIM | ID: wpr-173931

ABSTRACT

The apical surface of mammalian urinary epithelium is covered by numerous scallop-shaped membrane plaques. This plaque consists of four different uroplakins (UPs) and integral membrane proteins. UPs, which are a member of the tetraspanin superfamily, are assembled into plaques that act as an exceptional barrier to water and toxic materials in urine. Within the plaques, the four UPs are organized into two heterodimers consisting of UP Ia/UP II and UP Ib/UP III in the endoplasmic reticulum. The two heterodimers bind to a heterotetramer, and then assemble into 16-nm particles in the Golgi apparatus. The aggregated UP complex ultimately covers almost all the mature fusiform vesicles in cytoplasm. These organelles migrate towards the apical urothelial cells, where they can fuse with the apical plasma membrane. As a result, the UPs are synthesized in large quantities only by terminally differentiated urothelial cells. For this reason, the UPs can be regarded as a major urothelial differentiation marker. In UP knockout (KO) mice, the incorporation of fully assembled UP plaques in cytoplasm into the apical surface is not functional. The mice with UP III-deficient urothelium show a significantly reduced number of UPs, whereas those with UP II-deficient urothelium have nearly undetectable levels of UPs. This finding strongly suggests that UP II ablation completely abolishes plaque formation. In addition, UP II KO mice contain abnormal epithelial polyps or complete epithelial occlusion in their ureters. UP IIIa KO mice are also associated with impairment of the urothelial permeability barrier and development of vesicoureteral reflux as well as a decrease in urothelial plaque size. In this review, I summarize recently published studies about UPs and attempt to explain the clinical significance of our laboratory results.


Subject(s)
Animals , Cell Membrane , Cytoplasm , Endoplasmic Reticulum , Epithelium , Golgi Apparatus , Membrane Proteins , Membranes , Mice , Models, Animal , Organelles , Permeability , Polyps , Ureter , Urinary Tract , Uroplakins , Urothelium , Vesico-Ureteral Reflux , Water
19.
Protein & Cell ; (12): 935-943, 2010.
Article in English | WPRIM | ID: wpr-757684

ABSTRACT

Hearing impairment (HI) affects 1/1000 children and over 2% of the aged population. We have previously reported that mutations in the gene encoding gap junction protein connexin-31 (C×31) are associated with HI. The pathological mechanism of the disease mutations remains unknown. Here, we show that expression of C×31 in the mouse inner ear is developmentally regulated with a high level in adult inner hair cells and spiral ganglion neurons that are critical for the hearing process. In transfected cells, wild type C×31 protein (C×31wt) forms functional gap junction at cell-cell-contacts. In contrast, two HI-associated C×31 mutants, C×31R180X and C×31E183K resided primarily in the ER and Golgi-like intracellular punctate structures, respectively, and failed to mediate lucifer yellow transfer. Expression of C×31 mutants but not C×31wt leads to upregulation of and increased association with the ER chaperone BiP indicating ER stress induction. Together, the HI-associated C×31 mutants are impaired in trafficking, promote ER stress, and hence lose the ability to assemble functional gap junctions. The study reveals a potential pathological mechanism of HI-associated C×31 mutations.


Subject(s)
Animals , Connexins , Genetics , Ear, Inner , Metabolism , Endoplasmic Reticulum , Physiology , Gap Junctions , Genetics , Metabolism , Physiology , Golgi Apparatus , Genetics , Metabolism , Hearing Loss , Genetics , Metabolism , Pathology , Mice , Mutation , Neurons , Metabolism , Protein Transport , Genetics , Stress, Physiological
20.
Journal of Biomedical Engineering ; (6): 1085-1088, 2010.
Article in Chinese | WPRIM | ID: wpr-260933

ABSTRACT

The Golgi complex is the central organelle of the secretory pathway and has many complicate functions. The endeavours to isolate and purify the Golgi apparatus from cultured cells will benefit further investigation of Golgi. A large number of gastric cancer cells SGC7901 were cultivated in vitro, then Golgi apparatus were isolated from the cells by differential centrifugation combined with sucrose density gradient ultra-centrifugation. Its purity was characterized biochemically by enzymatic assays, morphologically by electron microscopy (EM) and neutral red supravital staining. Finally the Golgi complex was successfully fractionated from gastric cancer cells SGC7901. The first successful isolation of Golgi apparatus from gastric cancer cells SGC7901 by using ultra-centrifugation will lead to research into the function of Golgi apparatus.


Subject(s)
Cell Line, Tumor , Golgi Apparatus , Histological Techniques , Humans , Stomach Neoplasms , Pathology
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