Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.3.1 (alkaline phosphatase)
47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The distribution pattern of alkaline phosphatase was studied in the ganglion cells in and near the temporal bone of some mammals. No or extremely weak activity of alkaline phosphatase was observed in or near the spiral and vestibular ganglion cells of the bat, rat, cat, and monkey. However, intense to moderate enzyme activity was noted exclusively in the peripheral areas of the spiral and vestibular ganglion cells of the guinea pig. The enzyme activity was also demonstrated in the nerve fibers at some distance from both axonal and dendritic processes of the spiral and vestibular ganglion cells of the guinea pig. Trigeminal and geniculate ganglion cells of all mammals examined showed intense to moderate enzyme activity in their capsular cells. There is a marked difference in the phosphate metabolism in the capsular tissues of the ganglion cells in or near the temporal bone of various mammals.
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PMID:Alkaline phosphatase activity in the ganglion cells in and near the temporal bone. 11 55

beta,beta'-Iminodipropionitrile (IDPN) administration produces giant neurofilament-filled axonal swellings in the first proximal internodes of large myelinated sensory and motor fibers without any accompanying axonal degeneration. In the present study, we asked whether proximal giant axonal swellings are sufficient to elicit aberrant neurofilament (NF) phosphorylation in neuronal perikarya. Rats were given a single intraperitoneal (i.p.) injection of IDPN (2 g/kg) followed by IDPN (0.1%) in the drinking water (continuous IDPN exposure) or tap water (single IDPN exposure) for two days to 7 weeks. Immunoreactivity to phosphorylated NF (pNF) epitopes (using monoclonal antibodies 6-17 and 7-05) was observed in L4 and L5 dorsal root ganglia (DRG) neurons beginning between one and 5 days, corresponding to the development of proximal giant axonal swellings. Quantitation of DRG neurons demonstrated maximal numbers of immunoreactive cell bodies to pNF epitopes (46-51%) by one week. The number of immunostained DRG cells was maintained in animals given continuous IDPN exposure, but declined significantly (P less than 0.001) in rats given a single injection of IDPN to 26 +/- 0.80% and 6 +/- 0.04% at 3 and 5 weeks, respectively. Ventral and dorsal root fibers, which undergo axonal atrophy distal to axonal swellings, showed intense immunoreactivity to pNF epitopes and a marked reduction or a complete lack of immunostaining to antibody 2-135 (directed against non-phosphorylated NF epitopes); pretreatment with alkaline phosphatase reversed this staining pattern. In a separate study, a similar alkaline phosphatase-sensitive lack of staining to antibody 2-135 was also observed in atrophic motor fibers in the DRG 4 weeks following nerve crush. It is suggested that aberrant NF phosphorylation in DRG neuronal cell bodies from IDPN-treated rats arises secondarily to an alteration in a retrogradely transported 'trophic' signal(s) to the neuron due to the presence of giant axonal swellings. Furthermore, pNFs in atrophic axons may correspond to stationary or slowly moving NFs in the axoplasm.
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PMID:Regulation of aberrant neurofilament phosphorylation in neuronal perikarya. III. Alterations following single and continuous beta, beta'-iminodipropionitrile administrations. 172 19

Physicians and surgeons have long recognized that septic illness may be accompanied by abnormal brain functions; however, no systematic, comprehensive study has been done to define the clinical and laboratory features of the syndrome of sepsis-associated encephalopathy. We undertook such a prospective study in a tertiary care hospital and found that of 69 patients with fever and microbial cultures, 32 had marked brain dysfunction, 17 showed mild encephalopathy, and 20 were clinically nonencephalopathic. Severe cases showed obtundation and paratonic rigidity while milder cases showed confusion, inappropriate behavior, inattention, disorientation, and writing errors. There were no focal neurological deficits. The following factors correlated with the severity of brain dysfunction: adult respiratory distress syndrome; fatal outcome; certain types of EEG abnormality; axonal peripheral neuropathy; elevated peripheral white blood cell count; elevated serum levels of alkaline phosphatase, bilirubin, creatinine, phosphate, potassium, and urea; reduced blood pressure and reduced serum albumin level. Our data suggest that brain functions fail with dysfunction of other organs in septic illness. Pathogenetic mechanisms are discussed. The brain dysfunction should be regarded as potentially reversible, even in severely encephalopathic cases. Prompt control of the infection is the most important measure in controlling the encephalopathy and in preventing the increased mortality found with severely encephalopathic patients.
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PMID:The encephalopathy associated with septic illness. 207 9

In the corpus callosum of the cat, the heavy subunit of neurofilaments (NFH) can be demonstrated with the monoclonal antibody NE14, as early as P11, not at P3, and only in a few axons. At P18-19 and more markedly at P29, many more callosal axons have become positive to NE14 and this is similar to what is found in the adult. In contrast, callosal axons become positive to the neurofilament antibody SMI-32 only between P29 and P39 and remain positive in the adult. Treatment with alkaline phosphatase prevents axonal staining with NE14, but results in SMI-32 staining of a few callosal axons as early as P11, but not at P3. Between P11 and P19 the number of axons stained with SMI-32 after alkaline phosphatase treatment increases, in parallel with that of axons stained with NE14. Thus NE14 appears to recognize a phosphorylated form of NFH, while SMI-32 appears to recognize an epitope of NFH which is either masked by phosphate or inaccessible until between P29 and P39, unless the tissue is treated with alkaline phosphatase. These two forms of NFH appear towards the end of the period of massive developmental elimination of callosal axons. They are also synchronous with changes in the spacing of neurofilaments quantified in a separate ultrastructural study. These cytoskeletal changes may terminate the juvenile-labile state of callosal axons and allow further axial growth of the axon.
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PMID:Developmental changes in the heavy subunit of neurofilaments in the corpus callosum of the cat. 212 24

Three monoclonal antibodies to neurofilaments (RT97, BF10 and 147), two of which also recognised neurofibrillary tangles (RT97 and BF10), have all been shown to be specific for phosphorylated epitopes. Treatment of histological sections with alkaline phosphatase prior to immunostaining resulted in reduction of axonal neurofilament staining with all three whilst the neurofibrillary tangles staining with BF10 was unaffected. Antibody 147 was found to recognise weakly some neurofibrillary tangles following alkaline phosphatase treatment. The results presented confirm the presence of structurally abnormal but phosphorylated neurofilaments in neurofibrillary tangles.
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PMID:Alzheimer neurofibrillary tangles contain phosphorylated and hidden neurofilament epitopes. 243 88

Eleven anti-neurofilament (anti-NF) monoclonal antibodies were studied for their reactivity with heat-stable, microtubule-associated proteins and Alzheimer neurofibrillary tangles (ANT). On immunoblots of NF proteins, the antibodies recognized epitopes that were variably sensitive to Escherichia coli alkaline phosphatase. Eight of the antibodies showed reactivity with ANT and decreased binding to electroblotted NF after phosphatase treatment. The same eight antibodies reacted with tau proteins from bovine and rat brain, binding to tau proteins was also substantially reduced by phosphatase. Of the eight antibodies that bound to animal tau proteins, five also bound to tau proteins from normal human brain. All of the antibodies that bound to animal tau proteins stained ANT in frozen tissue sections. Brief treatment of tissue sections with trypsin in most cases enhanced antibody binding to ANT. All antibodies that lacked reactivity with tau proteins failed to bind ANT. Phosphatase treatment of Alzheimer tissue sections did not change the immunoreactivity of ANT and neurites in senile plaques with ANT-reactive, anti-NF antibodies, except for two antibodies that showed decreased binding to ANT. In contrast, axonal staining was decreased or eliminated by phosphatase treatment, similar to the response of electroblotted NF and tau proteins. These results suggest that staining of ANT by anti-NF antibodies may be due to cross-reaction of anti-NF with epitopes in tau proteins, the epitopes in axons, NF, and tau are sensitive to the effect of phosphatase, whereas the majority of those in ANT are not, and some of the epitopes in ANT that are shared with NF and tau proteins are not readily accessible to antibody binding.
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PMID:Recognition of tau epitopes by anti-neurofilament antibodies that bind to Alzheimer neurofibrillary tangles. 243 79

We have characterized stages in the posttranslational processing of the three neurofilament subunits, High (NF-H), Middle (NF-M), and Low (NF-L), in retinal ganglion cells in vivo during the interval between synthesis in cell bodies within the retina and appearance of these polypeptides in axons at the level of the optic nerve (optic axons). Neurofilament proteins pulse-labeled by injecting mice intravitreally with [35S]methionine or [32P]orthophosphate, were isolated from Triton-soluble and Triton-insoluble fractions of the retina or optic axons by immunoprecipitation or immunoaffinity chromatography. Within 2 h after [35S]methionine injection, the retina contained neurofilament-immunoreactive radiolabeled proteins with apparent molecular weights of 160, 139, and 70 kDa, which co-migrated with subunits of axonal neurofilaments that were dephosphorylated in vitro with alkaline phosphatase. The two larger polypeptides were not labeled with [32P]orthophosphate, indicating that they were relatively unmodified forms of NF-H and NF-M. About 75% of the subunits were Triton-insoluble by 2 h after isotope injection, and this percentage increased to 98% by 6 h. Labeled neurofilament polypeptides appeared in optic axons as early as 2 h after injection. These subunits exhibited apparent molecular weights of 160, 139, and 70 kDa and were Triton-insoluble. The time of appearance of fully modified polypeptide forms differed for each subunit (2 h for NF-L, 6-18 h for NF-M, 18-24 h for NF-H) and was preceded by the transient appearance of intermediate forms. The modified radiolabeled subunits in optic axons 3 days after synthesis were heavily labeled with [32P]orthophosphate and exhibited the same apparent molecular weights as subunits of axonal neurofilaments (70 kDa, 145 and 140 kDa, and 195-210 kDa, respectively). Whole mounts of retina immunostained with monoclonal antibodies against NF-H in different states of phosphorylation demonstrated a transition from non-phosphorylated neurofilaments to predominantly phosphorylated ones within a region of the axon between 200 and 1000 microns downstream from the cell body. These experiments demonstrate that the addition of most phosphate groups to NF-M and NF-H takes place within a proximal region of the axon. The rapid appearance of modified forms of NF-L after synthesis may imply that processing of this subunit occurs at least partly in the cell body. The presence of a substantial pool of Triton-insoluble, unmodified subunits early after synthesis indicates that the heaviest incorporation of phosphate occurs after neurofilament proteins are polymerized.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Early posttranslational modifications of the three neurofilament subunits in mouse retinal ganglion cells: neuronal sites and time course in relation to subunit polymerization and axonal transport. 246 28

A monoclonal antibody, C2, raised against chick embryo spinal cord, is shown by a solid phase immunoabsorbent assay to recognize a molecular species associated with neurofilaments extracted from adult mouse and rat brain. As immunoreactivity is lost following pre-treatment with alkaline phosphatase, the antibody probably recognizes a phosphorylated protein. Immunocytochemical staining in fetal mouse indicates that this antigen is expressed selectively in axons from the earliest stages of their development. Neuronal somata tend to show only weak immunoreactivity. The C2 antibody allowed visualization of the spatiotemporal pattern of axonal growth in the retina, neocortex and cerebellum with greater resolution than in previous light microscopic descriptions. The concept that the leading process of some classes of migratory neurons becomes transformed into an axon is supported by the expression of C2 immunoreactivity in radially ascending processes from principle neuron classes in the fetal retina and cerebellum.
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PMID:Early axonal differentiation in mouse CNS delineated by an antibody recognizing extracted neurofilaments. 250 10

Monoclonal antibodies to squid neurofilament (aNFP) and intermediate filament (aIFA) proteins were used as probes for the biochemical and immunocytochemical analyses of neurofilament structure and distribution in the squid giant axon and stellate ganglion. On Western blots the aNFP antibody stained exclusively the 220 kDa and high-molecular-weight (HMW) components of neurofilaments in the giant axon, whereas the aIFA antibody primarily labeled the 60 kDa protein in the giant axon and the 60 and 65 kDa proteins in the stellate ganglion. Dephosphorylation of axoplasmic proteins by alkaline phosphatase resulted in a decrease in the molecular weights of both the 220 kDa and HMW neurofilament proteins and a concomitant loss of reactivity with the aNFP antibody on Western blots. This indicated that the aNFP antibody is specific for a phosphorylated epitope in the neurofilament. Increased dephosphorylation of the 220 kDa protein led to an enhanced immunostaining of the resultant 190 kDa polypeptide by the aIFA antibody, suggesting that the phosphorylated epitope may mask the conserved epitope recognized by aIFA. Light and electron microscopic immunocytochemical studies show intense labeling by the aNFP antibody in the giant axon. In contrast, the aIFA antibody labeled the glial cells around the giant axon intensely, while labeling of the giant axon itself was considerably less than that with the aNFP antibody. Since the 60 kDa protein in axoplasm is intensely stained by the aIFA antibody on Western blots, the relatively low amounts of labeling seen on semithin and thin sections of the giant axon by this antibody may be due to the masking of the 60 kDa protein by in situ fixed axoplasmic proteins. However, the aIFA antibody intensely labeled glial cells within the stellate ganglion and "islands" of filaments and nuclear membranes within ganglion cells. No reactivity for either antibody was seen in synapses. The aNFP antibody specifically labeled "beadlike" portions and cross-bridges on the axonal neurofilaments, suggesting that these components consist of the 220 kDa and HMW proteins. In contrast, the aIFA antibody labeled relatively smooth filaments in ganglion and glial cells. These data suggest that the 65 kDa protein represents the squid glial filament protein and that the 60 kDa protein found in axoplasm represents the low-molecular-weight subunit in the axonal neurofilament. The latter appears to be formed and/or organized in "islands" of filaments within ganglion cells.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Biochemical and immunocytochemical characterization and distribution of phosphorylated and nonphosphorylated subunits of neurofilaments in squid giant axon and stellate ganglion. 311 21

Sensory neurons in the dorsal root ganglion (DRG) were used in an in vivo pulse-chase labeling paradigm to examine the time course and nature of posttranslational processing of neurofilament (NF) proteins. Ganglia of adult rats were labeled with 35S-methionine and harvested 1-72 hr later. Samples containing the cell bodies and short initial axonal segments of DRG neurons were analyzed by 1- and 2-dimensional PAGE/fluorography. For comparison, axonally transported NF proteins (200, 145, and 68 kDa) were harvested from the sciatic nerve 21 d after labeling the fifth lumbar (L5) DRG. Analysis of the pulse-chase experiments revealed that the mature 200 kDa protein (NF200) was not identifiable in gels of DRG samples until 24-48 hr after labeling. Immunoblotting/fluorography of 2-dimensional gels with monoclonal antibodies to phosphorylated and unphosphorylated NF proteins identified the high-molecular-weight NF subunit in various stages of processing in the DRG between 1 and 48 hr after labeling. The precursor to NF200 migrated on 2-dimensional PAGE as a 160 kDa protein with a pI of about 7.2. During the next 48 hr, the migration of this protein progressively changed to the mature pattern of 200 kDa and a pI of about 5.2. The 145 and 68 kDa NF proteins exhibited very little change in migration on gels during this same interval. Dephosphorylation of mature NF proteins with E. coli alkaline phosphatase regenerated the 160 kDa precursor, confirming that phosphorylation was the main posttranslational mechanism involved in the maturation of newly synthesized high-molecular-weight NF protein. Detergent extraction of labeled DRGs suggested that the 160 kDa NF protein was present in assembled neurofilaments. Immunohistochemical experiments with monoclonal antibodies were performed to explore the intracellular location of phosphorylated and unphosphorylated high-molecular-weight NF protein. Analysis revealed that neuronal cell bodies, as well as short initial segments of DRG axons located within the ganglion, contained unphosphorylated NF protein, while axons in the distal nerve contained mature, phosphorylated NF200. These findings provide support for a model in which posttranslational processing of the 160 kDa precursor occurs in the initial axonal region of DRG cells after the assembled NFs have left the cell body and begun axonal transport.
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PMID:Characterization of posttranslational processing of the mammalian high-molecular-weight neurofilament protein in vivo. 311 26


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