Alternations in quantities and activities of erythrocyte cytosolic carbonic anhydrase isoenzymes in glucose-6-phosphate dehydrogenase-deficient individuals

Carbonic Anhydrase Sensitivity to Pesticides: Perspectives for Biomarker Development

Carbonic anhydrase (CA) is a widespread metalloenzyme playing a pivotal role in several physiological processes. Many studies have demonstrated the in vitro and in vivo sensitivity of CA to the exposure to several classes of pesticides in both humans and wildlife. This review aims to analyze and to discuss the literature available in this field, providing a comprehensive view useful to foresee perspectives for the development of novel CA-based pesticide biomarkers. The analysis of the available data highlighted the ability of several pesticide molecules to interact directly with the enzyme in humans and wildlife and to inhibit CA activity in vitro and in vivo, with possible alterations of key physiological functions. The analysis disclosed key areas of further research and, at the same time, identified some perspectives for the development of novel CA-based sensitive biomarkers to pesticide exposure, suitable to be used in several fields from human biomonitoring in occupational and environmental medicine to environmental monitoring on non-target species.

Carbonic Anhydrases: Role in pH Control and Cancer

The pH of the tumor microenvironment drives the metastatic phenotype and chemotherapeutic resistance of tumors. Understanding the mechanisms underlying this pH-dependent phenomenon will lead to improved drug delivery and allow the identification of new therapeutic targets. This includes an understanding of the role pH plays in primary tumor cells, and the regulatory factors that permit cancer cells to thrive. Over the last decade, carbonic anhydrases (CAs) have been shown to be important mediators of tumor cell pH by modulating the bicarbonate and proton concentrations for cell survival and proliferation. This has prompted an effort to inhibit specific CA isoforms, as an anti-cancer therapeutic strategy. Of the 12 active CA isoforms, two, CA IX and XII, have been considered anti-cancer targets. However, other CA isoforms also show similar activity and tissue distribution in cancers and have not been considered as therapeutic targets for cancer treatment. In this review, we consider all the CA isoforms and their possible role in tumors and their potential as targets for cancer therapy.

Physiological functions of the alpha class of carbonic anhydrases

Carbonic anhydrases are ubiquitous enzymes that catalyze the reversible hydration of carbon dioxide. These enzymes are of ancient origin as they are found in the deepest of branches of the evolutionary tree. Of the five different classes of carbonic anhydrases, the alpha class has perhaps received the most attention because of its role in human pathology. This review focuses on the physiological function of this class of carbonic anhydrases organized by their cellular location.

High-throughput capillary electrophoresis-mass spectrometry: from analysis of amino acids to analysis of protein complexes

Recent advances in capillary electrophoresis-mass spectrometry (CE-MS) interfacing using porous tip is leading to commercialization of CE-MS with a sheathless interface for the first time. The new sheathless interface in conjunction with CE capillary coatings using self-coating background electrolytes (BGE) has significantly simplified CE-MS analysis of complex mixtures. CE-MS, with its high separation efficiency, compound identification capability, and ability to rapidly separate compounds with a wide range of mass and charge while consuming only nanoliters of samples, has become a valuable analytical technique for the analysis of complex biological mixtures. These advances have allowed a single capillary to analyze a range of compounds including amino acids, their D/L enantiomers, protein digests, intact proteins, and protein complexes. With these capabilities, CE-MS is poised to become the multipurpose tool of separation scientists. More recently, an eight-capillary CE in conjunction with an 8-inlet mass spectrometry has allowed 8 CE-MS analyses to be performed concurrently, significantly increasing throughput.

Differential expression of glutathione-S-transferase isoenzymes in various types of anemia in Taiwan

BACKGROUND

Published reports concerning the expression of GST in various anemias including aplastic, hemolytic, iron deficiency and thalassemia anemia has been insufficient. We improved the conventional GST assay by incorporating a chloroform treatment to remove the interference of hemoglobin and evaluated the altered expression of GSTs in various anemias in Taiwan.

METHODS

We incorporated a chloroform treatment to eliminate the interference of hemoglobin. Erythrocyte total GST and isoenzymes activities from 35 control subjects and 125 subjects of various anemias, including aplastic, hemolytic, iron deficiency and thalassemia anemias were measured spectrophotometrically.

RESULTS

Chloroform treatment did not significantly affect GST activities in erythrocytes of control subjects while the activities of erythrocyte total GST and alpha-GST were significantly increased in all anemic patients (P<0.001). The expression of mu-GST was significantly decreased, although at a less extent, in cases of aplastic, iron deficiency and thalassemia anemia (P<0.05), but pi-GST was not physiologically different in various types of anemia.

CONCLUSION

The determination of changes in erythrocyte GST activity is a promising indicator of oxidative stress conditions that occur in various types of anemia. Measurement of GST activity might be useful for the evaluation of prophylactic treatment in trials of antioxidant strategies.

Differential expression of carbonic anhydrase isoenzymes in various types of anemia

BACKGROUND

The aim of the present study was to determine the concentrations of cytosolic carbonic anhydrase (CA) isoenzymes in erythrocytes of patients with aplastic, autoimmune hemolytic, iron deficiency or beta-thalassemia anemia.

METHODS

Western blotting and CA esterase activity analysis were used to analyze cytosolic erythrocyte CA isoenzymes in 118 subjects with various types of anemia and 35 healthy controls.

RESULTS

Total CA activity and CAII concentration of anemia patients were significantly higher than that of the control subjects while CAI concentration was significantly lower in patients of autoimmune hemolytic anemia (P<0.01). Compared with controls, CAIII concentration was lower in iron deficiency anemia (P<0.01), but higher in beta-thalassemia anemia (P<0.001).

CONCLUSIONS

Carbonic anhydrase isoenzymes may contribute differently to various types of anemia. CAI may be an indicator to differentiate autoimmune hemolytic anemia from other types of anemia. CAII provides the CA activity necessary for maintaining ion transport in erythrocytes while CAIII may play an agent against oxidative damage in iron deficiency and beta-thalassemia anemia.

Alternation of cytosolic carbonic anhydrase isoenzymes during deciduomatal development in pregnant mice

OBJECTIVE

To analyze the activity of cytosolic carbonic anhydrases (CAs) during the pre- and postimplantation stages of pregnancy in mice. Furthermore, to investigate the CA activity in mice in which abortion was induced by injection of substance P.

DESIGN

Controlled animal experiment.

SETTING

University research laboratory.

ANIMAL(S)

A total of 75 ICR mice (weight between 20-25 g) that showed two consecutive 4-day cycles.

INTERVENTION(S)

Substance P (2.4 microg/g) or CA inhibitor (100 microg/g), or both, were administered. Decidualized uterine tissues were collected on days 0.5-10.5 after administration.

MAIN OUTCOME MEASURE(S)

The activity, protein expression pattern, and mRNA level of decidual cytosolic CAs.

RESULTS

The abortion induced by injection of substance P led to an aberrant expression of cytosolic CA and a decreased number of embryos. Furthermore, substance P-induced abortion could be effectively inhibited by CA inhibitors.

CONCLUSIONS

Cytosolic CAs, especially CA II, may act as negative regulators in implantation, development, and maintenance of the pregnancy and therefore, this information could be further applied in developing therapies for human sterility.

Pharmacogenomics of diuretic drugs: data on rare monogenic disorders and on polymorphisms and requirements for further research

This review summarizes the current status of our knowledge about the role of pharmacogenetic variation in response to diuretics and suggests future research topics for the field. Genes with a role in the pharmacokinetics of most diuretics are renal drug transporters, especially OAT1, OAT3 and OCT2 (genes SLC22A6, SLC22A8 and SLC22A2) whereas variants in carbonic anhydrase (CA), cytochrome P450 enzymes and sulfotransferases are relevant only for specific substances. Genes on the pharmacodynamic side include the primary targets of thiazide, loop, K+-sparing and aldosterone antagonistic diuretics: NCC, NKCC2, ENaC and the mineralocorticoid receptor (genes SLC12A3, SLC12A1, SCNN1A, B, G and NR3C2). Rare variants of these proteins cause Gitelman’s syndrome, Bartter’s syndrome, Liddle’s syndrome or pregnancy-induced hypertension. Polymorphisms in these and in associated proteins such as GNB3, α-adducin and angiotensin-converting enzyme (ACE) seem to be clinically relevant. In conclusion, first knowledge has evolved that efficacy of diuretic drugs may be determined by genetic polymorphisms in genes determining pharmacokinetics and pharmacodynamics of this drug class. In the future, the selection of a diuretic drug or the dosing schedules may be individually chosen based on pharmacogenetic parameters, however, many questions remain to be answered before this fantasy becomes reality.

The differential expression of cytosolic carbonic anhydrase in human hepatocellular carcinoma

Cytosolic carbonic anhydrases (CAs), including CAI, CAII and CAIII are present in normal hepatocytes. This study was aimed to investigate the expression status of CAs in hepatocellular carcinomas (HCC) and cholangiocellular carcinoma (CCC) and the role of tumor progression. The activity, protein expression pattern and messenger RNA of cytosolic CA were analyzed by CA activity analysis, immunoblot and RT-PCR in 60 human hepatocellular carcinomas and 10 human cholangiocellular carcinoma surgical specimens. The in situ distribution of CAI, CAII and CAIII in hepatocellular carcinomas tissues were analyzed by immunohistochemistry. The result showed that in each of 60 human hepatocellular carcinomas and 10 cholangiocellular carcinoma, CA activity and protein expression in tumor area was significantly lower than that of paired adjacent normal tissues (P < 0.01), and mRNA expressions in tumor areas were also reduced (P < 0.001). Furthermore, the immunohistochemical studies have further confirmed this reduction of CAI, CAII and CAIII protein expression in tumor areas. There was a statistically significant reduction in the expression of cytosolic CAII in poorly differentiated cancer (P < 0.001). Furthermore, the reduction of CAI, CAII and CAIII in HCC tumor areas was also revealed in this study and this reduction might promote tumor cell motility and contribute to tumor growth and metastasis.

The aberrant expression of cytosolic carbonic anhydrase and its clinical significance in human non-small cell lung cancer

This study was designed to elucidate the possible relationship between the expression of cytosolic carbonic anhydrase (CA) and non-small cell lung cancer (NSCLC). The activity and protein expression patterns of carbonic anhydrase I (CAI) and II (CAII) of 70 NSCLC patients were analyzed by CA activity analysis, immunoblotting and immunohistochemical staining. The results showed that the CA activity and protein expression were significantly decreased in both squamous cell carcinoma (SCC) and adenocarcinoma (AD) (P<0.001 and P<0.001). From our study, it was suggested that the reduction of CAI and CAII in both SCC and AD patients may promote tumor cell motility and contribute to tumor growth and metastasis.