As the basic physiological function of synapses, vesicle cycling involves in many aspects of process. Among them, vesicle recycling is the basis of synaptic vesicle cycling. Studies show that clathrin mediated endocytosis is a major pathway of vesicle recycling, in which Dynamin plays an important role. Dynamin is a GTPases with molecular weight of 100 kD, which acts as "scissors" in the endocytosis, separating the clathrin coated pits from membrane. It has been found that Dynamin is associated with epilepsy, Alzheimer's disease, centronuclear myopathy, and several other neurological diseases. In this paper, we discussed the structure, function and regulation of Dynamin, and reviewed recent advance in the studies on Dynamin related diseases.
Clathrin ; physiology ; Coated Pits, Cell-Membrane ; physiology ; Dynamins ; physiology ; Endocytosis ; Humans ; Synapses ; physiology ; Synaptic Transmission ; Synaptic Vesicles ; physiology

The vertebrate neuromuscular junction (NMJ) is considered as a “tripartite synapse” consisting of a motor axon terminal, a muscle endplate, and terminal Schwann cells that envelope the motor axon terminal. The neuregulin 1 (NRG1)-ErbB2 signaling pathway plays an important role in the development of the NMJ. We previously showed that Grb2-associated binder 1 (Gab1), a scaffolding mediator of receptor tyrosine kinase signaling, is required for NRG1-induced peripheral nerve myelination. Here, we determined the role of Gab1 in the development of the NMJ using muscle-specific conditional Gab1 knockout mice. The mutant mice showed delayed postnatal maturation of the NMJ. Furthermore, the selective loss of the gab1 gene in terminal Schwann cells produced delayed synaptic elimination with abnormal morphology of the motor endplate, suggesting that Gab1 in both muscles and terminal Schwann cells is required for proper NMJ development. Gab1 in terminal Schwann cells appeared to regulate the number and process elongation of terminal Schwann cells during synaptic elimination. However, Gab2 knockout mice did not show any defects in the development of the NMJ. Considering the role of Gab1 in postnatal peripheral nerve myelination, our findings suggest that Gab1 is a pleiotropic and important component of NRG1 signals during postnatal development of the peripheral neuromuscular system.
Animals ; Mice ; Mice, Knockout ; Motor Endplate ; Muscle, Skeletal* ; Muscles ; Myelin Sheath ; Neuregulin-1 ; Neuromuscular Junction ; Peripheral Nerves ; Presynaptic Terminals ; Protein-Tyrosine Kinases ; Schwann Cells* ; Synapses* ; Vertebrates

The purpose of this study was to investigate the distribution of neuropeptide Y (NPY) in the cat spinal trigeminal subnucleus caudalis following pulpectomy of mandibular premolars and molar by means of an immunohistochemical and immunoelectron microscopic study. The animals were divided into normal and experimental group which were sacrificed at 14 days after pulpectomy. The results were as follows; 1. On the light microscopic observation of the spinal trigeminal subnucleus caudalis in normal group, NPY-immunoreactivity (IR) was weak within lamina I and lamina II outer. In pulpectomy group, NPY-IR was strong and appeared to extend into lamina I and lamina II inner at 14 days. 2. On the immunoelectron microscopic observation of the spinal trigeminal subnucleus caudalis in normal group, NPY-IR was revealed in axon terminals, dendrites, myelinated axons and unmyelinated axons. NPY-IR was associated with membrane structures within microtubules, synaptic vesicles, outer membrane of mitochondria and inner surface of the axolemma. In NPY-immunoreactive structure, there was a small amount of DAB precipita-tions. 3. On the immunoelectron microscopic observation of the spinal trigeminal subnucleus caudalis at 14 days in pulpectomy group, the number of NPY-immunoreactive axon terminals, dendrites, myelinated axons and unmyelinated axons was increased than normal group. DAB precipitations in NPY-immunoreactive structure was increased than normal group. Some NPY-immunoreactive axon terminal formed synaptic glomerulus and axoaxonic synapse. 4. The results indicate that NPY-IR was increased in the spinal trigeminal subnucleus caudalis after pulpectomy, and it is speculated that the increased NPY by injury of peripheral nerve may participate in the processing of nociception.
Animals ; Axons ; Bicuspid ; Cats* ; Dendrites ; Immunohistochemistry ; Membranes ; Microtubules ; Mitochondria ; Molar ; Myelin Sheath ; Neuropeptide Y* ; Neuropeptides* ; Nociception ; Peripheral Nerves ; Presynaptic Terminals ; Pulpectomy* ; Synapses ; Synaptic Vesicles

The most efficient means of protein internalization from the membrane are through clathrin-coated pits, which concentrate protein interactions with the clathrin-associated assembly protein complex AP-2 and internalization signals in the cytoplasmic domain of transmembrane proteins. Binding of clathrin assembly protein to clathrin triskelia induces their assembly into clathrin-coated vesicles (CCVs). Due to a difficulty of isolating clathrin molecules from their complex or assembly state in the cells, most of the studies were carried out with recombinant clathrin proteins, which may present different conformation and structural variation. In this study, we have developed an efficient method of isolating the native clathrin assembly protein lymphoid myeloid (CALM) from the bovine brain that is enriched with clathrin and clathrin associated proteins and characterized by their sensitivity to proteases and it's ability to form CCV. The purified CALM has molecular weight of approximately 100,000 dalton on SDS-PAGE, which is consistent with the result of in vitro translation. The purified CALM protein could promote the assembly of clathrin triskelia into clathrin cage, and cleaved CALM proteolysed by caspase 3 and calpain could not promote them. In this respect, our data support a model in which CALM functions like AP180 as a monomeric clathrin assembly protein and might take part in apoptotic process in neuronal cells.
Adaptor Proteins ; Animal ; Brain Chemistry ; Calpain/*metabolism ; Carrier Proteins ; Caspases/*metabolism ; Cattle ; Clathrin/*metabolism ; Coated Pits, Cell-Membrane/*metabolism ; Hydrolysis ; Membrane Proteins ; Molecular Weight ; Nerve Tissue Proteins/chemistry/*isolation & purification/metabolism ; Neurons/*chemistry ; Protein Binding ; Protein Conformation ; Recombinant Proteins/chemistry/metabolism

The most efficient means of protein internalization from the membrane are through clathrin-coated pits, which concentrate protein interactions with the clathrin-associated assembly protein complex AP-2 and internalization signals in the cytoplasmic domain of transmembrane proteins. Binding of clathrin assembly protein to clathrin triskelia induces their assembly into clathrin-coated vesicles (CCVs). Due to a difficulty of isolating clathrin molecules from their complex or assembly state in the cells, most of the studies were carried out with recombinant clathrin proteins, which may present different conformation and structural variation. In this study, we have developed an efficient method of isolating the native clathrin assembly protein lymphoid myeloid (CALM) from the bovine brain that is enriched with clathrin and clathrin associated proteins and characterized by their sensitivity to proteases and it's ability to form CCV. The purified CALM has molecular weight of approximately 100,000 dalton on SDS-PAGE, which is consistent with the result of in vitro translation. The purified CALM protein could promote the assembly of clathrin triskelia into clathrin cage, and cleaved CALM proteolysed by caspase 3 and calpain could not promote them. In this respect, our data support a model in which CALM functions like AP180 as a monomeric clathrin assembly protein and might take part in apoptotic process in neuronal cells.
Adaptor Proteins ; Animal ; Brain Chemistry ; Calpain/*metabolism ; Carrier Proteins ; Caspases/*metabolism ; Cattle ; Clathrin/*metabolism ; Coated Pits, Cell-Membrane/*metabolism ; Hydrolysis ; Membrane Proteins ; Molecular Weight ; Nerve Tissue Proteins/chemistry/*isolation & purification/metabolism ; Neurons/*chemistry ; Protein Binding ; Protein Conformation ; Recombinant Proteins/chemistry/metabolism

Sequential epithelial changes of the urinary bladder in rats induced by N-butyl-N-(4-hydroxybutyl) nitrosamine(BBN) were studied by means of transmission electron microscopy. 0.05% BBN was administered orally in Wistar strain rats for 4 to 12 weeks and sacrificed at the 4th to 20th week. The urinary bladder epithelial changes were classified into 4 categories by conventional light microscopic criteria; normal transitional epithelium, mucosal epithelial hyperplasia, transitional epithelial papilloma and transitional cell carcinoma. The ultrastructural characteristics of the urinary bladder epithelium in rats induced by BBN are as follows; 1. General cellular appearances corresponded to a gradual sequential changes from hyperplasia to carcinoma, and the basement membrane became uneven and/or incomplete in carcinoma. 2. Irregularity of nuclear configurations was proportionally increased together with nuclear membranes and chromatin. 3. Development of intercellular infoldings and desmosomes was much irregular and marked in the neoplastic lesions. 4. Alterations of subcellular organelles began to appear from the hyperplastic epithelium, and also were reflected by increased number of tonofibrils and desmosomal changes according to the degree of malignant potentiality.
Animals ; Basement Membrane ; Carcinoma, Transitional Cell ; Chromatin ; Desmosomes ; Epithelium ; Hyperplasia ; Microscopy, Electron, Transmission ; Nuclear Envelope ; Organelles ; Papilloma ; Rats* ; Urinary Bladder*

Artificial skin can be employed as a useful model for investigating skin disease and clinical application such as burn. To evaluate this, the skin was reconstructed by culturing keratinocytes in airfluid interface over the collagen lattice and ultrastructures was also investigated by electron microscope. Epidermis showed more than 10 layers including basal, spinous, granular and honey layers but basement membrane and anchoring fibrils were not formed at the dermoepidermal junction. Desmosomes were formed at cell junctions but reduced in number. Intermediate filaments were scarce and fine, especially at the spinosal layer. Keratohyalin granules were smaller and fewer than those of in vivo. Parakeratosis was observed at the honey layer. It was, therefore, concluded that the artificial skin could be a valuable experimental model although the differentiation process of keratinocytes was somewhat unstable.
Basement Membrane ; Burns ; Cell Culture Techniques ; Collagen ; Desmosomes ; Epidermis ; Honey ; Intercellular Junctions ; Intermediate Filaments ; Keratinocytes ; Models, Theoretical ; Parakeratosis ; Skin ; Skin Diseases ; Skin, Artificial*

Introduction of patch-clamp techniques allowed an increase in resolution of membrane current recordings. However, the technique was limited by apparent need for direct contact of pipette with cell membrane. Thus, this technique was restricted to isolated or cultured cell preparation. Although much has been achieved with such preparations, the studies of synapsis between cultured cells are undefined. Many of these problems were overcome by application of patch-clamp techniques to brain-slices. The use of high-resolution optics allowed visualization of cells to be recorded. It was possible to remove tissue covering cells and record currents in synaptically connected neurons. The brain-slice technique has greatly facilitated the investigation of electrical properties of neurons and the analysis of synaptic transmission between neurons. "Blow and seal"technique, when combined with infrared differential interference contrast video microscopy, permits recording of membrane potential and currents, not only from large cell body of neurons, but also from small processes. The technique offers many advantages, such as the case with which patch-pipette recordings can be made, the possibility of identifying cell type prior to recording and finally, the ability to visualize and record electrical activity from different compartments or from more than one site in the same neuron.
Anesthetics, General ; Cell Membrane ; Cells, Cultured ; Chromosome Pairing ; Membrane Potentials ; Membranes ; Microscopy, Video ; Neurons ; Patch-Clamp Techniques ; Synaptic Transmission

PURPOSE: The aim of this study was to determine whether plasma lecithin:cholesterol acyltransferase (pLCAT) and erythrocyte membrane Na(+)-K(+)-ATPase ase (emNaKATPs) activity have a correlation in breast cancer. This study compared these parameters at time points before and after treatment with radiotherapy. METHODS: The levels of pLCAT and emNaKATPs were assessed in 30 patients with breast carcinoma and 20 control subjects. While emNaKATPs was measured with spectrophotometric method, pLCAT levels was measured using a specific enzyme-linked immunosorbent assay. RESULTS: pLCAT levels, both before and after radiotherapy, were found to be decreased in breast cancer patients than in the controls groups (p<0.001 and p<0.001, respectively). Also, pLCAT levels after radiotherapy were found to be decreased in breast cancer patients than the pLCAT levels before radiotherapy (p<0.001). The emNaKATPs activity were higher in the control group than in the breast cancer patients before/after radiotherapy (RT) (p<0.001 and p<0.001, respectively). At the same time, emNaKATPs activity before RT was higher in the breast cancer patients than emNaKATPs activity after RT (p<0.001). There was a significant correlation between pLCAT and emNaKATPs activity in breast cancer patients receiving radiotherapy (r=0.63, p<0.001), but no correlation between in breast cancer patients before RT and control group (r=0.023, p>0.05). CONCLUSION: The results of the present study demonstrated that decreased pLCAT and emNaKATPs activity levels in breast cancer patients after/before RT than control group. In addition, decreased emNaKATPs activity in breast cancer patients receiving radiotherapy may be due to decreased pLCAT concentrations and RT beam. In our opinion, altered activities of pLCAT and emNaKATPs are linked to the treatment effect of radiotherapy. These data may clarify the development of cell membrane dysfunction and lipid metabolism in breast cancer patients receiving radiotherapy.
Breast ; Breast Neoplasms ; Cell Membrane ; Cholesterol ; Erythrocyte Membrane ; Humans ; Lecithins ; Lipid Metabolism ; Plasma ; Sterol O-Acyltransferase

Solitary plasmacytoma, in contrast to the disseminated neoplastic proliferation of plasma cells with marked infiltration of multiple organ system in multiple myeloma, is plasma cell neoplasm of a single focus occuring either in bone or soft tissue. The association between a solitary plasmacytoma and peripheral neuropathy is rare, and it is a progressive sensorimotorneuropathy, with a raised CSF protein and mixed demyelination and axonal loss in nerve biopsy. Localized radiotherapy indeed proves to be effective of not only arresting the progress of the neuropathy but also allowing a degree of recovery. We experienced a 55-year-old male with a solitary plasmacytoma and peripheral neuropathy confirmed by the radiologic studies, immunohistochemical stain of nasopharyngeal mucosa biopsy and sural nerve biopsy, which has loss of myelinated fiber and axonal degeneration. Until now, the reported cases are very rare in Korea, so we presented a case of solitary plasmacytoma associated with peripheral neuropathy.
Axons ; Biopsy ; Demyelinating Diseases ; Humans ; Korea ; Male ; Middle Aged ; Mucous Membrane ; Multiple Myeloma ; Myelin Sheath ; Neoplasms, Plasma Cell ; Peripheral Nervous System Diseases* ; Plasma Cells ; Plasmacytoma* ; Radiotherapy ; Sural Nerve