Serum carbonic anhydrase III in neuromuscular disorders and in healthy persons after a long-distance run

Exploring the Redox and pH Dimension of Carbonic Anhydrases in Cancer: A Focus on Carbonic Anhydrase 3

Significance: Both redox and pH are important regulatory processes that underpin cell physiological functions, in addition to influencing cancer cell development and tumor progression. The thioredoxin (Trx) and glutathione redox systems and the carbonic anhydrase (CA) proteins are considered key regulators of cellular redox and pH, respectively, with components of the Trx system and CAs regarded as cancer therapeutic targets. However, the redox and pH axis in cancer cells is an underexplored topic of research. Recent Advances: Structural studies of a CA family member, CA3, localized two of its five cysteine residues to the protein surface. Redox-regulated modifications to CA3 have been identified, including glutathionylation. CA3 has been shown to bind to other proteins, including B cell lymphoma-2-associated athanogene 3, and squalene epoxidase, which can modulate autophagy and proinflammatory signaling, respectively, in cancer cells. Critical Issues: CA3 has also been associated with epithelial-mesenchymal transition processes, which promote cancer cell metastasis, whereas CA3 overexpression activates the phosphatidylinositol-3 kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway, which upregulates cell growth and inhibits autophagy. It is not yet known if CA3 modulates cancer progression through its reported antioxidant functions. Future Directions: CA3 is one of the least studied CA isozymes. Further studies are required to assess the cellular antioxidant role of CA3 and its impact on cancer progression. Identification of other binding partners is also required, including whether CA3 binds to Trx in human cells. The development of specific CA3 inhibitors will facilitate these functional studies and allow CA3 to be investigated as a cancer therapeutic target.

Affinity proteomics within rare diseases: a BIO-NMD study for blood biomarkers of muscular dystrophies

Despite the recent progress in the broad-scaled analysis of proteins in body fluids, there is still a lack in protein profiling approaches for biomarkers of rare diseases. Scarcity of samples is the main obstacle hindering attempts to apply discovery driven protein profiling in rare diseases. We addressed this challenge by combining samples collected within the BIO-NMD consortium from four geographically dispersed clinical sites to identify protein markers associated with muscular dystrophy using an antibody bead array platform with 384 antibodies. Based on concordance in statistical significance and confirmatory results obtained from analysis of both serum and plasma, we identified eleven proteins associated with muscular dystrophy, among which four proteins were elevated in blood from muscular dystrophy patients: carbonic anhydrase III (CA3) and myosin light chain 3 (MYL3), both specifically expressed in slow-twitch muscle fibers and mitochondrial malate dehydrogenase 2 (MDH2) and electron transfer flavoprotein A (ETFA). Using age-matched sub-cohorts, 9 protein profiles correlating with disease progression and severity were identified, which hold promise for the development of new clinical tools for management of dystrophinopathies.

Purification of swine carbonic anhydrase isoenzyme III and measurement of its levels in tissues and plasma

The changes in the levels of carbonic anhydrase isozyme III (CA-III) in swine plasma and urine have not been previously determined or reported. CA-III is relatively specific to skeletal muscles, and should therefore be a useful diagnostic marker for muscle diseases. We isolated CA-III from swine muscle tissues and determined CA-III levels in the plasma and urine from both healthy and diseased pigs. The levels of CA-III in the tissues of female swine (age, 3 months) and plasma of young swine (age, 1-5 months) and adult female pigs (age, 2-3 years) were determined using the ELISA system for swine CA-III. The mean (± SD) levels of CA-III in the skeletal muscles were 3.8 ± 3.2 mg/g (wet tissue), and in the plasma, 230 ± 193 ng/ml at 1 month, 189 ± 208 ng/ml at 2 months, 141 ± 148 ng/ml at 3 months, 78 ± 142 ng/ml at 4 months and 53 ± 99 ng/ml at 5 months. The mean level of CA-III in the plasma samples from 2- to 3-year-old pigs was 18 ± 60 ng/ml. CA-III in the plasma samples was found to decrease from 1 month until 3 years of age (p < 0.01). We performed far-western blotting to clarify the cause of the observed decrease in CA-III in plasma. Our results demonstrated that CA-III is bound to the transferrin and albumin. In addition, we determined that the levels of CA-III in plasma and urine samples were higher in diseased swine compared with the healthy pigs.

Laboratory testing in the diagnosis and management of idiopathic inflammatory myopathies

Laboratory testing commonly used to assess the idiopathic inflammatory myopathies (IIMs) can be divided into three categories: (1) measurement of serum activities or concentrations of muscle-derived factors--such as enzymes, myoglobin, and other molecules--in order to assess muscle injury; (2) immunologic tests that detect markers of the disease process, including serum autoantibodies that have been associated with myositis; and (3) general laboratory tests that are used to assess the patient's general status and medical condition. The laboratory assessment of muscle-derived factors that reflect muscle injury, and the determination of serum autoantibodies, play valuable roles in the diagnosis and management of the IIM. Enzyme elevations do not correlate with disease activity in all patients, however, and they must be interpreted within the clinical context. Autoantibodies can identify disease subsets with distinctive patterns of clinical manifestations, genetics, responses to therapy and prognosis, but disease-specific autoantibodies are present in only half of patients with IIM. Recent studies have defined additional myositis autoantibodies that may improve our capacity to diagnose and manage the IIM.

Localization of a protein inhibitor of carbonic anhydrase in pig tissues

The protein inhibitor of carbonic anhydrase (CA), pICA, was localized in pig tissues by an immunohistochemical technique, using rabbit antipICA IgG. Staining for pICA was found in liver sinusoids and kidney glomeruli, where phagocytic cells are located, i.e. Kupffer and mesangial cells, respectively. pICA was not found inside parenchymal cells, or in tissues from striated muscle, heart, eye or lung. It is concluded that the function of pICA is perhaps to bind the carbonic anhydrase isozymes CA I, II, and III, released from erythrocytes into the blood circulation by intravascular haemolysis. The complex of CA-pICA in plasma may then be transported to the reticuloendothelial system, for degradation and reclamation of CA-bound zinc. This would be similar to the fate of the haemoglobin-haptoglobin complex for the recycling of iron.

Isolation and measurement of carbonic anhydrase isoenzyme III in plasma, sera, and tissues of dogs

OBJECTIVE

To purify canine carbonic anhydrase isoenzyme III (CA-III) and determine plasma, serum, and tissue concentrations of CA-III in healthy dogs and dogs with experimentally induced muscle damage.

ANIMALS

121 healthy Beagles.

PROCEDURE

Muscle was obtained from 2 Beagles after euthanasia, and CA-III was purified and characterized by use of column chromatography and electrophoresis, respectively. A CA-III-specific ELISA was developed to determine concentrations of CA-III in plasma of 116 dogs and tissues of 1 dog. Serum creatine kinase (CK) activity and CA-III concentration were also determined before and after induction of muscle damage by IM injection of 2 ml of 10% lidocaine to 2 dogs.

RESULTS

Canine CA-III had a molecular weight of 28 kd and an isoelectric point of 8.2. Mean (+/- SD) concentration of CA-III in plasma of healthy dogs was 16.91 +/- 9.55 ng/ml. The highest tissue concentration of CA-III was detected in skeletal muscle. Serum concentration of CA-III increased and peaked within the first 2 to 3 hours after induction of muscle damage. The increase in CA-III concentration was more rapid than that of CK activity, and concentration reached its maximum and returned to baseline sooner than did CK activity.

CONCLUSIONS AND CLINICAL RELEVANCE

The CA-III ELISA we developed was a sensitive method for determining CA-III concentrations in plasma, serum samples, and tissue specimens of dogs. Use of this ELISA requires only a small volume of serum and may enable the study of changes in CA isoenzyme concentrations associated with muscle disorders in dogs.

Characteristics of myoglobin, carbonic anhydrase III and the myoglobin/carbonic anhydrase III ratio in trauma, exercise, and myocardial infarction patients

Carbonic anhydrase III (CA III) is an enzyme present in skeletal muscle which is released into circulation following injury. Myoglobin (Mb) is a heme protein located in skeletal, smooth, and cardiac muscle which is also released after injury. Because CA III is not present in myocardium, combining serum CA III and Mb measurements may improve the specificity of Mb as an early diagnostic marker for myocardial infarction (MI) provided that a fixed ratio of Mb and CA III is released from skeletal muscle following cell injury. We examined release of Mb and CA III for exercise subjects (n=12), trauma patients (n=18), and MI patients (n=10) following emergency department admission. A fixed ratio of Mb/CA III had medians of 3.505 (range: 1.05-6.76) and 2.890 (range: 0.97-3.97) for exercise and trauma subjects, respectively, in samples collected within 5 h of the event. The Mb/CA III ratio was significantly higher (P<0.001) in MI patients (median: 35.395; range: 8.65-170.45) during this same time. This study confirmed that Mb and CA III are released in a fixed ratio following exercise, showed no significant difference in the ratio for trauma patients, and demonstrated significant ratio elevation for MI patients. These data suggest the ratio to be a useful diagnostic indicator of MI.

Chronic exertional rhabdomyolysis

This article presents a brief description of what is known about the cause and pathogenesis of chronic intermittent rhabdomyolysis in horses. Clinically applicable diagnostic tests and published results in affected horses, prophylaxis, and treatment of the acute case are discussed.

Determination of carbonic anhydrase-III by enzyme-immunoassay in liver, muscle and serum of male rats with streptozotocin-induced diabetes mellitus

Insulin has a plethora of metabolic effects but its action on carbonic anhydrase-III (CA-III), a key enzyme in acid-base regulation, has been little studied. The present studies examined the effects of streptozotocin induced diabetes on the concentrations of CA-III. The concentration of CA-III in the liver, muscles and serum of rats with experimental diabetes mellitus was measured by the method of enzyme-immunoassay. Streptozotocin-induced diabetes mellitus resulted in a reduction in concentration of CA-III in the liver and serum, but not in skeletal muscles, of adult male rats. A 98% reduction in hepatic CA-III content relative to control values was observed. The reduction in CA-III content in the liver was restored to control value by administration of insulin. The CA-III content in serum of diabetic rats declined to approx. 25% of control values, but the reduction was unaffected by administration of insulin. The concentration of CA-III in the liver and serum of diabetic rats was not influenced by administration of methyltestosterone. Although the content of CA-III in m. rectus femoris, m. tibialis craniaris and m. soleus differed, no significant difference of CA-III content was found between diabetes mellitus and control rats. The effect of chronic diabetes mellitus on CA-III content was obviously different between liver and muscle, suggesting that the regulation of CA-III biosynthesis differs between these two tissues. These results suggest that biosynthesis of CA-III in hepatocytes of rats is influenced by irregular patterns of GH secretion brought about by diabetes mellitus.

Laboratory evaluation of the inflammatory myopathies

The laboratory plays an important role in the diagnosis, evaluation, and classification of the heterogeneous group of diseases known as the IIM, which are characterized by chronic muscle inflammation. Serial measurements of the levels of muscle-derived enzymes in serum are the traditional laboratory studies used to follow the clinical course of patients with IIM, although other laboratory tests can also be useful in assessing myositis disease activity. Several markers of immune system activation, including cytokines and lymphocyte markers, show promise as possibly more sensitive measures of myositis disease activity. Discovery of a unique group of MSAs over the past decade has provided an immunologic basis for defining relatively homogeneous subsets of patients who share similar clinical features, disease courses, and responses to therapy. Future investigations of novel immunologic activation markers, as well as the cloning and expression of target autoantigens of the MSAs, should allow better diagnostic assays, enhanced prognosis, and a better understanding of the pathogenesis of these disorders.

Leakage of carbonic anhydrase III from normal and denervated rat skeletal muscle following contractile activity

Skeletal muscle extracellular carbonic anhydrase III was investigated in anesthetized rats by a microdialysis technique. A small dialysis probe was inserted into the tibialis anterior (TA) muscle and perfused continuously. Perfusates were collected before and during muscle contraction, induced by electrical stimulation of the muscle or of the sciatic nerve. In the perfusate of resting normal and denervated muscle, the concentration of CA III was 10 to 12 ng/mL, as measured by a radioimmunosorbent technique. During contractile activity, the concentrations of CA III increased markedly in the normal and denervated muscle. A TA muscle suspended in physiological saline behaved similarly, even though the leakage before and during contraction was higher than in vivo. The results show that skeletal muscle leaks CA III both in vivo and in vitro, a leakage which was markedly increased by contractile activity. The microdialysis technique should also be useful in humans to study the efflux of various proteins from different kinds of diseased or fatigued muscles.

Muscle ATP and lactate and the release of myoglobin and carbanhydrase III in acute lower-limb ischaemia

Serum-myoglobin and carbanhydrase III (S-CAIII), a specific muscle enzyme, were measured on admission, during surgery and in the postoperative period in 23 patients with acute lower-limb ischaemia and in 21 patients with chronic limb ischaemia in order to evaluate these molecules as possible markers of the degree of clinical ischaemia. The muscle contents of ATP and lactate were determined in muscle biopsies from patients with acute ischaemia on admission. Unlike S-myoglobin and S-CAIII they discriminated between cases which required subsequent amputation from those which did not. Clinical signs of ischaemia were, however, of no value in this respect and there were no correlations between clinical signs or the duration of ischaemia and S-myoglobin or S-CAIII or the contents of ATP or lactate in muscle tissue. The levels of S-myoglobin and S-CAIII correlated well (r = 0.95, p less than 0.0001). In patients who subsequently required an amputation S-myoglobin increased ten-fold (i.e., from 24-48 h postoperatively in acute arterial ischaemia and from 3 h postoperatively in patients with chronic limb ischaemia). In patients with a successful revascularisation S-myoglobin returned to normal levels. It is concluded that in this investigation S-myoglobin had no prognostic value on admission and that S-myoglobin analyses in the postoperative course may be useful for making clinical decisions concerning impending recirculation failures.

Carbonic anhydrase III in equine tissues and sera determined by a highly sensitive enzyme-immunoassay

A sensitive sandwich enzyme immunoassay (EIA) for measuring equine carbonic anhydrase III (CA-III) was established using a microplate as a solid-phase and peroxidase as a labelling enzyme. The assay can detect concentrations as low as 5 ng/ml using 20 microliters of sample sera. Within-run coefficients of variation obtained using standard equine CA-III were less than 5 per cent. CA-III levels in equine serum ranged from 5 to 50 ng/ml (n = 370), and apparently abnormal levels of CA-III from 100 to 1900 ng/ml (n = 27) were observed. The concentrations of immunoreactive CA-III in the extracts of various equine tissues were also determined; it was present at high concentrations in skeletal muscle and liver and to a much lesser extent in the thymus. Other tissues contained much smaller amounts.

Sex-linked variation in creatine kinase release, and its dependence on oestradiol, can be demonstrated in an in-vitro rat skeletal muscle preparation

Creatine kinase (CK) release from male and female rat soleus muscles was studied for 4.5 h in vitro, under basal conditions and after electrical stimulation. Basal CK release was greater from male than from female muscles, and CK release from male muscles increased significantly when the muscle tension in the in-vitro set-up was increased. CK release after electrical stimulation was also more marked in male soleus muscles. Pretreatment of male rats and ovariectomized female rats with oestradiol for 3 weeks attenuated the enzyme efflux, but ovariectomy 24 h before in females, or oestradiol administration 24 h before in males, did not affect the release of CK in vitro. The data show that sex-linked differences in CK efflux are still present, under both basal and stimulated conditions, when muscles are isolated from the intact animal, and that hormone treatment of the intact animal affects these properties in the isolated muscle in vitro.

Serum carbonic anhydrase III, an enzyme of type I muscle fibres, and the intensity of physical exercise

The effects of 30 min running with stepwise increasing intensity (exhaustive, energy demand approx. 50----100% of VO2max), 60 s supramaximal running (anaerobic, greater than or equal to 125% of VO2max) and 40-60 min low-intensity running (aerobic, 40-60% of VO2max) on serum concentration of muscle-derived proteins were studied in 5 male and 5 female elite orienteerers. S-Carbonic anhydrase III (S-CA III) was used as a marker of protein leakage from type I (slow oxidative) muscle fibres and S-myoglobin (S-Mb) as a non-selective (type I + II) muscular marker. The fractional increase in S-CA III (delta S-Ca III) was 0.37 +/- 0.09 (mean +/- SEM, p less than 0.001), 0.10 +/- 0.05 (N. S.) and 0.46 +/- 0.09 (p less than 0.001) 1 h after exhaustive, anaerobic and aerobic exercise, respectively. The corresponding values for delta S-Mb were 1.45 +/- 0.36 (p less than 0.001), 0.39 +/- 0.13 (p less than 0.01) and 0.67 +/- 0.18 (p less than 0.001). The value for the delta S-CA III/delta S-Mb ratio was 0.68 +/- 0.03 after the aerobic exercise, but only 0.25-0.26 (p vs. aerobic exercise less than 0.001) after the two high-intensity forms of exercise. Since type I fibres of skeletal muscle are known to be responsible for power production during low-intensity exercise, whereas fibres of both type I and type II are active at higher intensities, the delta S-CA III/delta S-Mb ratio may depend on the recruitment profile of type I vs. type I + II fibres.

Histochemical localization of carbonic anhydrase in normal and diseased human muscle

A method is described for histological localization of carbonic anhydrase (CA) in sections of frozen human muscle using the rapid and inexpensive histochemical technique of Hansson. Results obtained in normal subjects indicate clearly that CA reactive fibers are of type 1. Similarly, abnormalities seen with CA in the muscle biopsy of a patient presenting with type 1 fiber hypotrophy and preponderance duplicated almost exactly those observed with the actinomyosine adenosine triphosphatase and the reduced nicotinamide adenine dinucleotide dehydrogenase reactions. Observations of grouped CA-positive muscle fibers in a case of chronic neurogenic atrophy suggest that, like other enzymes, CA expression in muscle is under neurogenic control.

Immunocytochemical localisation of carbonic anhydrase isozyme III in equine skeletal muscle

The location of carbonic anhydrase III (CA-III) in frozen sections of biopsies of Thoroughbred horse skeletal muscle was studied. Fibre types were determined by ATP-ase and succinate dehydrogenase staining. CA-III isozyme was detected using a peroxidase conjugated anti-CA-III antibody. CA-III was found to be localised in slow twitch oxidative fibres (ST), but was also present in fast twitch oxidative (FTH) fibres in small amounts. Fast twitch glycolytic (FT) fibres were stained lightly compared with control sections. The concentrations of CA-III in muscle and liver were 70 micrograms/mg protein and 4 micrograms/mg protein, respectively. CA-I and CA-II were not found in muscle extracts by the double immunodiffusion method.