Response of axons and glia at the site of anastomosis between the optic nerve and cellular or acellular sciatic nerve grafts

Axonal and glial reactions at the site of optic nerve section and at the junctional zone between optic nerve and normal or acellular peripheral nerve grafts have been studied. Following optic nerve section, no axons grew into the distal optic nerve stump. Similarly, no axons invaded the acellular peripheral nerve grafts, although in both instances fibres did regenerate into the junctional zone and a few remained there at least until 30 days post lesion (dpl, the duration of the experiments). Axons regenerated into normal peripheral nerve grafts by 3-5 dpl and by 10 dpl large numbers had penetrated deeply into the grafts. The glial response to injury appeared similar in both groups of grafted animals. Astrocytes and oligodendrocytes grew out into the junctional zone over the 5-7 day period and invaded the margins of the cellular grafts by 10 dpl. They did not penetrate the acellular nerves or distal optic nerve stumps. We were unable to determine whether Schwann cells invaded the junctional zone from the normal peripheral nerve grafts. Schwann cells are both GFAP+ and Vim+, especially when reacting after injury, and Lam- when not associated with axons: it is therefore possible that Schwann cells from the cellular grafts contributed to the population of GFAP+, Vim+ cells in the junctional zone of the cellular grafts. Anti-laminin immunoreactivity persisted in the basal lamina tubes of both the normal and acellular peripheral nerve grafts. Thus, the failure of axon regeneration into acellular peripheral nerve grafts can be correlated with the absence of Schwann cells and does not appear to be related to the presence of laminin.

Immunocytochemical characteristics of Müller cells cultured from adult rabbit retina

The antigenic expression of glial fibrillary acidic protein (GFAP), vimentin, S-100 protein and neurofilament triplex polypeptide was examined in cultured glial (Müller) cells from adult rabbit retina using immunocytochemical techniques. Most of the cultured cells were labelled with carbonic anhydrase C which has been considered to be the most specific marker of Müller cells. Most of the cultured cells were also positive for GFAP, a result which differs from previous observations on whole retina. Using a double labelling technique, 70-90% of cultured cells showed positive labelling for GFAP and vimentin although the staining intensity was stronger in the case of the latter. Fifty to seventy percent of cultured cells showed positive immunofluorescence to S-100 protein. Immunoelectron microscopy confirmed that GFAP and vimentin were localised along the intermediate glial filaments. S-100 protein was present in both the cytoplasm and the nucleoplasm of the majority of cells, but surprisingly in approximately 30% of cells the nucleoplasm was not labelled, a result which again is different from previously reported studies on whole retina. Neurofilament triplex polypeptide was not identified either by immunofluorescence or by immunoelectron microscopy. The results indicate that Müller cells in culture show a different antigenic expression to similar cells in whole retina.

Comparative immunochemical studies of carbonic anhydrase III in horses and other mammalian species

1. Carbonic anhydrase III (CA-III) from different mammalian species (horse, cow, dog, cat, rat and rabbit) has been analyzed by the immunodiffusion technique with anti-equine CA-III serum. 2. Immunodiffusion demonstrated the absence of cross-reactivity between isozyme CA-I, CA-II, and CA-III. 3. Cross-reactions were observed between the CA-III from all the species examined except the rabbit. 4. Molecular weights and isoelectric points of CA-III from different species were determined by Western blotting.

Monoclonal antibody toward lysosomal cathepsin B cross-reacts preferentially with distinct histone classes

1. A set of monoclonal antibodies (Mab) was prepared against cathepsin B (CB) from rat preputial-gland, an organ characterized by rapidly-renewing cell populations, which is a uniquely enriched source of lysosomal enzymes, including CB. Minute amounts of CB are known to be transferred abruptly to the nuclear compartment in a variety of activated cells. 2. Since, on the basis of its stringent substrate requirements, CB was expected to function at limited protein loci in chromatin, Mab Line II-B4 was used to probe Western blots of chromatin fractions and selected proteins. 3. The Mab, which was not directed against the active site of CB, cross-reacted preferentially with histones 3 and 4 (H3 and H4) in acid-soluble fractions of chromatin from rat preputial-gland. Line II-B4 also recognized H3 and H4 selectively in calf thymus histones and among histones purified from a wide range of sources from yeast to man. HMG 1 was minimally immunoreactive among preputial gland constituents and carbonic anhydrase (CA) was also sensitive to the Mab. 4. The common determinants were not shared by any of the H1 series, nor by H2A, H2B, protein A24 or a wide range of natural and synthetic products. 5. Origin of the antigenicity was traced by chemical modifications of H3, H4 and CA to the critical contribution of arginine and hydrophobic amino acid residues in its immediate environment, indicating that Line II-B4 may be directed against an epitope comprising the specific binding-site of CB and its selective substrate(s). 6. These data suggest that certain highly conserved cellular constituents may be uniquely vulnerable to limited proteolysis in preproliferative cells responding to mitotic signals.

Regulation of carbonic anhydrase III by thyroid hormone: opposite modulation in slow- and fast-twitch skeletal muscle

This laboratory previously reported that a major 30 kilodalton (kDa) protein of the soluble cytoplasmic fraction of the rat slow-twitch soleus muscle is modulated by thyroid hormone. This protein has been purified and a portion of the primary structure has been determined. The sequence analysis suggested that the 30-kDa protein is carbonic anhydrase III (CA III; EC 4.2.1.1). The reaction of the protein with a CA III specific antibody and the similar modulation of CA III by thyroid hormone also support this conclusion. Immunochemical quantification of CA III and measurement of CA activity were performed in skeletal muscles of defined fiber-type composition from rats that were rendered hyperthyroid by treatment with 3,3',5-triiodo-L-thyronine. These experiments revealed that CA activity and CA III content are deinduced in the soleus muscle (primarily type I fibers) and induced in the superficial vastus lateralis muscle (primarily type IIb), whereas no changes were detected in the tibialis anterior muscle (primary type IIa). These results show that the modulation of CA III by thyroid hormone in rat skeletal muscle is not limited to the slow-twitch soleus muscle and that the amplitude and direction of this modulation are directly related to the initial fiber-type composition of the skeletal muscle.

Immunocytochemical characterization of carbonic anhydrase-rich cells in the rat kidney collecting duct

Immunocytochemical detection of carbonic anhydrase (CA II), (Na+-K+)-ATPase and the anion channel (band 3) glycoprotein was used to study structural and functional heterogeneity of cells lining the collecting ducts, especially of intercalated cells, in the rat kidney. High content of CA II was found in intercalated cells as determined by morphology, although a weak diffuse cytoplasmic staining of this enzyme could be observed also in a subpopulation of principal cells. (Na+-K+)-ATPase could be detected exclusively in principal cells, whereas basolateral band 3 immunoreactivity was seen only in a subpopulation of intercalated cells. Double immunostaining experiments revealed that the weak cytoplasmic type of CA II and basolateral (Na+-K+)-ATPase immunoreactivities were colocalized in 20 to 30% (depending on the segment studied) of the collecting duct epithelial cells but, in contrast, cells rich in CA II or those with basal band 3 immunoreactivity seldom contained (Na+-K+)-ATPase. Instead, band 3 glycoprotein and the abundant CA II were colocalized in 20 to 35% of the cells in various segments of collecting ducts, whereas, band 3 and weak cytoplasmic CA II were seldom seen in the same cells. The results show that the current approach is useful for identifying and characterizing two distinct subpopulations of intercalated cells, both rich in CA II but differing in respect to the presence or absence of band 3 glycoprotein. On the basis of physiologic and biochemical data of the functions of these transport proteins we propose that the subpopulations of intercalated cells thus identified represent the acidifying and alkalinizing subtypes, respectively.

Purification and characterization of human salivary carbonic anhydrase

A novel carbonic anhydrase was purified from human saliva with inhibitor affinity chromatography followed by ion-exchange chromatography. The molecular weight was determined to be 42,000 on sodium dodecyl sulfate polyacrylamide gel electrophoresis, indicating that the human salivary enzyme is larger than the cytosolic isoenzymes CA I, CA II, and CA III (Mr 29,000) from human tissue sources. Each molecule of the salivary enzyme had two N-linked oligosaccharide chains which were cleaved by endo-beta-N-acetylglucosaminidase F but not by endo-beta-N-acetylglucosaminidase H, indicating that the oligosaccharides are complex type. The isoelectric point was determined to be 6.4, but significant charge heterogeneity was found in different preparations. The human salivary isozyme has lower specific activity than the rat salivary isozyme and the human red blood cell isozyme II in the CO2 hydratase reaction. The inhibitory properties of the salivary isozyme resemble those of CA II with iodide, sulfanilamide, and bromopyruvic acid, but the salivary enzyme is less sensitive to acetazolamide and methazolamide than CA II. Antiserum raised in a rabbit against the salivary enzyme cross-reacted with CA II from human erythrocytes, indicating that human salivary carbonic anhydrase and CA II must share at least one antigenic site. CA I and CA III did not crossreact with this antiserum. The amount of salivary carbonic anhydrase in the saliva of the CA II-deficient patients was greatly reduced, indicating that the CA II deficiency mutation directly or indirectly affects the expression of the salivary carbonic anhydrase isozyme. From these results we conclude that the salivary carbonic anhydrase is immunologically and genetically related to CA II, but that it is a novel and distinct isozyme which we tentatively designate CA VI.

Carbonic anhydrase I is an early specific marker of normal human erythroid differentiation

The expression of carbonic anhydrase (CA) as a marker of erythroid differentiation was investigated by immunologic and enzymatic procedures. A polyclonal anti-CA antibody was obtained by immunizing rabbits with purified CA I isozyme. This antibody is reactive with CA I but not with CA II. Within blood cells, CA I was only present in erythrocytes, whereas CA II was also detected in platelet lysates by enzymatic assay. Concerning marrow cells, identifiable erythroblasts and some blast cells expressed CA I. Most of the glycophorin A-positive marrow cells were clearly labeled by the anti-CA I antibody. However, rare CA I-positive cells were not reactive with anti-glycophorin A antibodies. We therefore investigated whether these cells were erythroid precursors or progenitors. In cell sorting experiments of marrow cells with the FA6 152 monoclonal antibody, which among hematopoietic progenitors is reactive only with CFU-E and a part of BFU-E, was performed, CA I+ cells were found mainly in the positive fraction. The percentage of CA I+ cells nonreactive with anti-glycophorin A antibodies contained in the two fractions was in the same range as the percentage of erythroid progenitors identified by their capacity to form colonies. In addition, the anti-CA I antibody labeled blood BFU-E-derived colonies as early as day 6 of culture, whereas in similar experiments with the anti-glycophorin A antibodies, they were stained three or four days later. No labeling was observed in CFU-GM- or CFU-MK-derived colonies. The phenotype of the day 6 cells expressing CA I was similar to that of erythroid progenitors (CFU-E or BFU-E): negative for glycophorin A and hemoglobin, and positive for HLA-DR antigen, the antigen identified by FA6 152, and blood group A antigen. Among the cell lines tested, only HEL cells expressed CA I, while K562 was unlabeled by the anti-CA I antibody. In contrast, HEL and K562 cells expressed CA II as detected by a biochemical technique. Synthesis of CA I, as with other erythroid markers such as glycophorin A and hemoglobin, was almost abolished after 12-O-tetradecanoyl-phorbol-13 acetate treatment of HEL cells. In conclusion, CA I appears to be an early specific marker of the erythroid differentiation, expressed by a cell with a similar phenotype as an erythroid progenitor.

Comparative characterization of monoclonal antibodies to carbonic anhydrase

Monoclonal antibodies (Mabs) were generated to avian carbonic anhydrase-C and characterized; their reactivity with human, murine, bovine, chicken and fish erythrocyte carbonic anhydrase-C, and with human carbonic anhydrase-B was investigated by ELISA and electroblot techniques. Reactivity of the Mabs with native and SDS-denatured carbonic anhydrase was compared. Mabs that recognize antigenic determinants shared by all the carbonic anhydrases examined were identified. The results demonstrate the potential usefulness of these particular probes for investigating various aspects of function, evolution, development and regulation of this important, but not well understood group of enzymes.

Immunohistochemical localization of carbonic anhydrase I and II in eccrine sweat glands from control subjects and patients with cystic fibrosis

Isozymes of carbonic anhydrase (CA) were localized immunohistochemically by the immunoglobulin-peroxidase bridge technique on fixed paraffin sections of human eccrine sweat glands. Low-activity CA I was identified in the cytoplasm of the myoepithelial cells in the secretory coil and in the luminal and basal cells of both the coiled and straight segments of the duct. High-activity CA II was found in the cytoplasm of clear cells of the secretory coil. Although evidence has suggested that CA activity is altered in cystic fibrosis (CF), the present immunohistochemical comparison of CF sweat glands revealed a distribution of and, semiquantitatively, a prevalence of CA isozymes identical to those of normal sweat glands. Abnormal enzyme activity cannot be ruled out, however, on the basis of immunocytochemical staining which depends solely on the antigenic properties of CA.

Immunolabeling of carbonic anhydrase isoenzyme C and glial fibrillary acidic protein in paraffin-embedded tissue sections of human brain and retina

The specificities of carbonic anhydrase isoenzyme C (CA C) and glial fibrillary acidic (GFA) protein as immunocytochemical markers for different glial cell populations in human brain and retina were studied using indirect immunofluorescence and peroxidase-antiperoxidase complex methods. With antibodies against CA C, only those cerebral cells that were morphologically oligodendrocytes and Müller cells of the retina showed positive immunostaining reaction, whereas antibodies against GFA protein selectively labeled cerebral astrocytes and a part of the glial cells and fibers in the inner layers of the retina. In double labeling, when both glial cell markers were successively localized in the same cerebral tissue sections, GFA protein immunofluorescence was never found in the immunoperoxidase-stained CA C-positive cells, which further supports the oligodendrocyte-specificity of CA C in human brain.

Chemical and enzymological characterization of an Indonesian variant of human erythrocyte carbonic anhydrase II, CAII Jogjakarta (17 Lys leads to Glu)

A new variant of human erythrocyte carbonic anhydrase II (CAII) was discovered in a single heterozygous individual during routine screening of blood samples from the island of Java in Indonesia. The normal and variant components of the heterozygous CAII mixture were resolved by isoelectric focusing following purification by a specific affinity matrix. Specific esterase activities and Michaelis-Menten constants were identical. Only very small differences were noted with respect to inhibition by acetazolamide and chloride. Double diffusion analysis showed the immunological identify of the normal and variant enzymes. The variant CAII was considerably less heat stable than the normal enzyme. The variant was slightly more stable than the normal enzyme upon dialysis against the zinc chelator dipicolinic acid (PDCA), indicating a tighter binding of zinc than the normal enzyme. Analysis of tryptic peptides from the normal and variant enzymes indicated that, in the variant, lysine at position 17 from the N terminus had changed to glutamic acid. The differences in physiochemical properties observed for the normal and variant enzyme are discussed in relation to the possible effects of this substitution on the structure of the CAII molecule.

Cross-reactions among carbonic anhydrases I, II, and III studied by binding tests and with monoclonal antibodies

Cross-reactions among carbonic anhydrases (CAs) I, II, and III were studied using a variety of antisera: (1) a rabbit antiserum to bovine CA III, (2) mouse antisera to human CA I, CA II, and CA III; and (3) five monoclonal antibodies prepared by the hybridoma technique using splenocytes from a mouse immunized with human CAs I and II and bovine CA III. Cross-reactions between CAs were readily found by binding assays using these antisera. Human CA I, but not human CA II, inhibited the reaction of the rabbit anti-CA III with its homologous antigen. Mouse antisera to CA I or CA III bound the homologous I or II with nearly as great efficiency as the autologous isozyme and sometimes weakly bound CA III. Mouse antisera to CA III frequently bound CA I or II. These cross-reactions were confirmed by the first use of hybridoma-prepared, monoclonal antibodies to CAs. The mouse monoclonal antibodies to CA isozymes varied in the amount of cross-reactivity among I, III, and III: at one extreme, one monoclonal was highly specific for the autologous CA III; at the other extreme, one monoclonal weakly reacted with some examples of CSs I, II, and III.

Comparative antigenic structure of carbonic anhydrases CA I and CA II from human and mammalian origin

1. Isolated carbonic anhydrases CA I and CA II from different species (man, ox, sheep, pig, dog and rat) have been analyzed by immunodiffusion techniques using rabbit specific CA I or CA II antisera. 2. Immunodiffusion shows the absence of cross-reactivity between CA I and CA II isoenzymes. 3. Common antigenic determinants (cross-reactivities) were evidenced between the CA I of the different species under study. 4. To the contrary, cross-reactivity between CA II of the species mentioned above, can clearly be demonstrated only between bovine and sheep CA II.

Reactivation and immunological studies on a Japanese variant of red cell carbonic anhydrase I, CA I Hiroshima

1. Under certain conditions, CA I HIR-1 (86 Asp leads to Gly) was inactivated in Gnd . HCl more rapidly than normal CA I. 2. After denaturation in 5.0 M Gnd . HCl, CA I HIR-1 was reactivated more slowly than normal CA I. 3. CA I HIR-1 was precipitated by purified anti-CA I antibodies, under certain conditions, more rapidly than normal CA I.

A radioimmunosorbent technique for the assay of B- and C-types of carbonic anhydrase in human tissues

A radioimmunosorbent technique for the assay of the human carbonic anhydrase isoenzymes HCA B and HCA C in tissue fluids was developed. The sensitivity of the method was 0.2 ng/ml and the precision was 5% in duplicate determinations for both enzymes. The presence in a tissue of up to 20 times higher concentrations of one isoenzyme will not interfere with the assay of the other. Haemolysates contained (mean +/- SE, n = 11) 12.1 +/- 0.52 and 1.5 +/- 0.06 mg enzyme/g Hb, and serum 0.63 +/- 0.12 and 0.2 +/- 0.02 microgram/ml of HCA B and HCA C, respectively. Pilot experiments indicated that the isoenzymes can be determined also in tissues, i.e. urine, saliva and cerebrospinal fluid, where catalytic methods previously have indicated absence of or only weak carbonic anhydrase activity. N-terminals of both enzymes were not antigenic.

Immunohistochemical demonstration of carbonic anhydrase

Rabbits were immunized using human erythroxyte carbonic anhydrase B (HCA B) purified by the modified methods of Armstrong et al. (1966) and Bernstein and Schraer (1972). The globulin fraction was isolated by ammonium sulphate precipitation. The anti-HCA B globulin was specific, when judged using the double diffusion technique of Ouchterlony and immunoelectrophoresis. No cross reaction with human erythrocyte carbonic anhydrase C was found, but cross reactions with erythrocyte carbonic anhydrase from rat, mouse and guinea pig were observed. Flurorescein isothiocyanate conjugated goat anti-rabbit globulin was used for the localization of HCA B in tissue sections and erythrocytes on slides.

Selective tissue distribution of carbonic anhydrase isozymes in the ox

By affinity chromatography the isozymic distribution of carbonic anhydrase (carbonate hydro-lyase, EC 4.2.1.1) has been studied in extract from various bovine tissues. Carbonic anhydrase II forms isolated from erythrocyte, kidney and brain are indistinguishable by specific activity, amino acid composition, fingerprint, electrophoretic and immunological behaviour. By these criteria they differ from carbonic anhydrase I isolated from rumen epithelium.

Relationship between precipitate volume and antigen weight in immunodiffusion

Immunodiffusion of antigen from conic and cylindrical wells of various sizes in thick antiserum gel plate was studied. The shape of precipitate was affected by the shape and size of the well and by the antigen weight. In the test of anti-rabbit serum agar plate, albumin concentration ranged from 2 to 25 mg/ml, and the maximal albumin weight was 15.8 times the minimal one. In this case, regression line and standard deviation (S.D.) were calculated from antigen weight (x) and standardized data (y1) of precipitate volume, and from antigen weight and standardized data (y2) of precipitation ring area, and the following results were obtained: y1=0.006x-1.611, S.D.=0.092 for the former and y2=0.005x-1.546, S.D.=0.295, for the latter. In the test of agar plates containing anti-carbonic anhydrase B (CA B), the maximal concentration and weight of CA B was 16.7 times and 18.3 times the minimal one, respectively. In this case, regression line and standard deviation obtained from the CA B weight (x) and the standardized data (y3) of the precipitate volume, and from the weight (x) and the standardized data (y4) of the precipitation ring area were as follows: y3=0.146x-1.754, S.D.=0.208, and y4=0.104x-1.251, S.D.=0.717, respectively. There was a clearer linearity in the relationship between the precipitate volume and the antigen weight than in that between the ring area and the antigen weight. In the gel medium, antigen concentration gave no influences on antigen quantitation at the end point of antigen diffusion in a wide range.

Characterisation of carbonic anhydrases from tissues of the cat

1. Red blood cells from several members of the cat family have been found to contain only carbonic anhydrase (EC 4.2.1.1) isozymes of the "high activity" (carbonic anhydrase II class) in red blood cells. 2. Two carbonic anhydrase II type isozymes have been isolated from red cells of the domestic cat. Kinetic and structural characterisation shows that the two isozymes have identical composition except for a probable difference of one amide group. The general characteristics of cat red cell carbonic anhydrase are similar to other mammalian carbonic anhydrase II isozymes, in particular the dog carbonic anhydrase II. 3. A carbonic anhydrase I (low activity) isozyme has been isolated and characterised from cat caecal mucosa. This carbonic anhydrase I is similar to the carbonic anhydrase I extracted from canine red cells. Comparative studies showed that whereas members of the dog family have carbonic anhydrase I and carbonic anhydrase II in red cells the cat family has only a carbonic anhydrase II type isozyme, however, cat liver and spleen homogenates were also found to contain carbonic anhydrase I identical to that found in caecum.

Human renal carbonic anhydrase. Purification and properties

Carbonic ahyndrase was isolated from fresh human donor kidneys which had been thoroughly perfused free from blood. The isolation procedure involved biospecific affinity chromatography on a sulfanilamide-agarose column and yielded one soluble form of the enzyme, which was homogenous with respect to sedimentation in the ultracentrifuge, electrophoresis, isoelectric focusing and immunodiffusion. The renal enzyme had an amino acid composition and beahved chromatographically, electrophoretically, and immunochemically like the erythrocyte form human carbonic anhydrase C, isolated by the same technique. The kinetic behaviour of the renal enzyme was similar to that of human carbonic anhydrase C when compared by the stopped-flow pH-indicator technique. The results therefore suggest that the cytoplasmic carbonic anhydrase of the human kidney is very similar, if not identical, to the high-activity erythrocyte form of human carbonic anhydrase C.

Evidence of existence of two isozymes of carbonic anhydrase in the anterior pituitary gland of female rats

Two molecular forms of carbonic anhydrase were identified in the rat anterior pituitary gland. Electrophoretic and immunological studies disclosed that the low activity carbonic anhydrase (type B) was associated with the particulate fraction of the pituitary gland and the high activity carbonic anhydrase (type C) was localized in the soluble fraction. The 800 times g pellet contained 50% of the total activity of a pituitary homogenate prepared in 0.25 M sucrose, while the 105,000 times g supernatant accounted for an additional 30% of the total. The particulate enzyme was rendered soluble by treatment with Trition X-100. The activity of pituitary gland carbonic anhydrase was about 6 times greater in preparations from female rats as compared with males. The activity of carbonic anhydrase in the particulate fraction decreased, and the activity in the soluble fraction increased without a change in total activity following incubation in vitro of pituitary glands. The intracellular adjustment in enzyme activity was accompanied by the secretion of prolactin into the incubation medium by the pituitary gland. The secretion of prolactin and the solubilization of the particulate carbonic anhydrase was inhibited when the pituitary gland was incubated in the presence of 10-5 M dopamine.