[Acatalasemia and type 2 diabetes mellitus]. / A veleszületett katalázhiány (acatalasaemia) és a 2-es típusú diabetes mellitus.

The catalase enzyme decomposes the toxic concentrations of hydrogen peroxide into oxygen and water. Hydrogen peroxide is a highly reactive small molecule and its excessive concentration may cause significant damages to proteins, deoxyribonucleic acid, ribonucleic acid and lipids. Acatalasemia refers to inherited deficiency of the catalase enzyme. In this review the authors discuss the possible role of the human catalase enzyme, the metabolism of hydrogen peroxide, and the phenomenon of hydrogen peroxide paradox. In addition, they review data obtained from Hungarian acatalasemic patients indicating an increased frequency of type 2 diabetes mellitus, especially in female patients, and an early onset of type 2 diabetes in these patients. There are 10 catalase gene variants which appear to be responsible for decreased blood catalase activity in acatalasemic patients with type 2 diabetes. It is assumed that low levels of blood catalase may cause an increased concentration of hydrogen peroxide which may contribute to the pathogenesis of type 2 diabetes mellitus.

Long-term follow-up evaluation of an acatalasemia boy with severe periodontitis.

BACKGROUND: Acatalasemia is a rare genetic catalase deficiency that is inherited as an autosomal recessive trait. Although usually asymptomatic, a syndrome of oral ulcerations and gangrene may be present (Takahara's disease). In this report, we presented the diagnosis and 15-y periodontal treatments of an acatalasemia patient with Takahara's disease in China. METHODS: To confirm the diagnosis of acatalasemia, intron 4 of the catalase gene was amplified and sequenced. Erythrocyte catalase activity was measured by ultraviolet spectrophotometer. Besides, periodontal treatments and 15y follow-up were performed. RESULTS: Direct sequencing showed a clear splicing mutation of guanine to adenine substitution at the fifth position of intron 4 in the patient. Erythrocyte catalase activity of the patient (5.2MU/l, 4.6%) was 10% lower than the normal range (113.3±16.5MU/l). After 15-y treatments, the periodontal pocket depth ≥4mm and clinical attachment loss reduced to 30% and 3.7±1.2mm. CONCLUSIONS: Based on these findings, a diagnosis of acatalasemia was established. And the periodontal therapies have achieved a stable periodontal status.

Acatalasemic mice are mildly susceptible to adriamycin nephropathy and exhibit increased albuminuria and glomerulosclerosis.

BACKGROUND: Catalase is an important antioxidant enzyme that regulates the level of intracellular hydrogen peroxide and hydroxyl radicals. The effects of catalase deficiency on albuminuria and progressive glomerulosclerosis have not yet been fully elucidated. The adriamycin (ADR) nephropathy model is considered to be an experimental model of focal segmental glomerulosclerosis. A functional catalase deficiency was hypothesized to exacerbate albuminuria and the progression of glomerulosclerosis in this model. METHODS: ADR was intravenously administered to both homozygous acatalasemic mutant mice (C3H/AnLCs(b)Cs(b)) and control wild-type mice (C3H/AnLCs(a)Cs(a)). The functional and morphological alterations of the kidneys, including albuminuria, renal function, podocytic, glomerular and tubulointerstitial injuries, and the activities of catalase were then compared between the two groups up to 8 weeks after disease induction. Moreover, the presence of a mutation of the toll-like receptor 4 (tlr4) gene, which was previously reported in the C3H/HeJ strain, was investigated in both groups. RESULTS: The ADR-treated mice developed significant albuminuria and glomerulosclerosis, and the degree of these conditions in the ADR-treated acatalasemic mice was higher than that in the wild-type mice. ADR induced progressive renal fibrosis, renal atrophy and lipid peroxide accumulation only in the acatalasemic mice. In addition, the level of catalase activity was significantly lower in the kidneys of the acatalasemic mice than in the wild-type mice during the experimental period. The catalase activity increased after ADR injection in wild-type mice, but the acatalasemic mice did not have the ability to increase their catalase activity under oxidative stress. The C3H/AnL strain was found to be negative for the tlr4 gene mutation. CONCLUSIONS: These data indicate that catalase deficiency plays an important role in the progression of renal injury in the ADR nephropathy model.

Acatalasemia and diabetes mellitus.

The enzyme catalase catalyzes the breakdown of hydrogen peroxide into oxygen and water. It is the main regulator of hydrogen peroxide metabolism. Hydrogen peroxide is a highly reactive small molecule formed as a natural byproducts of energy metabolism. Excessive concentrations may cause significant damages to protein, DNA, RNA and lipids. Low levels in muscle cells, facilitate insulin signaling. Acatalasemia is a result of the homozygous mutations in the catalase gene, has a worldwide distribution with 12 known mutations. Increased hydrogen peroxide, due to catalase deficiency, plays a role in the pathogenesis of several diseases such as diabetes mellitus. Diabetes mellitus is a disorder caused by multiple genetic and environmental factors. Examination of Hungarian diabetic and acatalasemic patients showed that an increased frequency of catalase gene mutations exists among diabetes patients. Inherited catalase deficiency may increase the risk of type 2 diabetes mellitus, especially for females. Early onset of type 2 diabetes occurs with inherited catalase deficiency. Low levels of SOD and glutathione peroxidase could contribute to complications caused by increased oxidative stress.

Catalase -262C>T polymorphisms in Hungarian vitiligo patients and in controls: further acatalasemia mutations in Hungary.

Catalase is the main regulator of hydrogen peroxide metabolism. In vitiligo patients there are conflicting data on its activity and no data on the effect of -262C>T polymorphism in the catalase gene. Blood catalase activity, -262C>T polymorphism and acatalasemia mutations were examined in 75 vitiligo patients and in 162 controls, in Hungary. We measured blood catalase activity and conducted analyses with PCR-SSCP, polyacrylamide gel electrophoresis and silver staining in combination with RFLP and nucleotide sequencing. Comparison of the wild (CC) genotype and the mutant (TT) genotype in the vitiligo patients revealed a non significant (P > 0.19) increase in blood catalase. Male controls with the CT genotype had significantly (P < 0.04) lower blood catalase activity than CC genotype controls. Female vitiligo patients with CC genotype had lower (P < 0.04) blood catalase than female controls. The frequency of wild genotype (CC) and C alleles is significantly (P < 0.04) decreased in Hungarian controls when compared to controls in Slovenia, Morocco, UK, Greece, Turkey, USA, China. The detection of a novel acatalasemia mutation (37C>T in exon 9) and the 113G>A (exon 9) mutation in Hungary are further proofs of genetic heterogeneity origin of acatalasemia mutations. In conclusion, the -262 C>T polymorphism has a reverse effect on blood catalase in vitiligo patients and in controls. In controls the mutant genotypes and alleles are more frequent in Hungary than in several other populations. The new acatalasemia mutations are further examples of heterogeneity of acatalasemia.

Cardiac manifestation in Takayasu arteritis.

We present two case reports of young women with Takayasu arteritis and cardiovascular complications. The first case is a female patient suffering from significant aortic valve regurgitation, the second case is a woman who presents with amaurosis fugax and develops acute chest pain with heart failure. In this report we review cardiac involvement in Takayasu arteritis.

Low catalase activity in blood is associated with the diabetes caused by alloxan.

BACKGROUND: Hydrogen peroxide is enzymatically processed by catalase, and catalase deficiency in blood is known as acatalasemia. We examined whether low catalase activity is a risk factor for diabetes mellitus. METHODS: Blood glucose, insulin and glucose tolerance test were examined in acatalasemic and normal mice under non-stress and oxidative stress conditions. Alloxan administration was used as oxidative stress. RESULTS: Alloxan, which was a drug that caused diabetes mellitus, mostly generated hydrogen peroxide by the reaction of alloxan and reduced glutathione, in vitro. Incidence of hyperglycemia in alloxan-untreated acatalasemic mice was as low as that in the normal mice. However, the incidence of acatalasemia mice treated with alloxan was higher than that in normal mice, and the number of pancreatic beta-cells in the acatalasemic mice was less than that in normal mice. CONCLUSION: These results indicate that low catalase activity in the blood is associated with the diabetes mellitus caused by alloxan administration.

Increased susceptibility to oxidant-mediated tissue injury and peritoneal fibrosis in acatalasemic mice.

BACKGROUND: Peritoneal fibrosis is a major complication leading to the loss of peritoneal function in patients undergoing peritoneal dialysis. However, the effect of catalase depletion on peritoneal fibrosis has not yet been investigated. METHODS: The impact of catalase deficiency on progressive peritoneal fibrosis has been studied in homozygous acatalasemic mutant mice or control wild-type mice by intraperitoneal injection of chlorhexidine gluconate (CG) every other day for 14 days. RESULTS: The CG injections resulted in a thicker peritoneal membrane, reflecting peritoneal fibrosis with accumulation of interstitial type I collagen, peritoneal deposition of lipid peroxidation products (4-hydroxy-2-nonenal and 4-hydroxy-2-hexenal), and an elevated level of 8-hydroxy-2'-deoxyguanosine in peritoneal fluid in both mouse groups on day 14. The extent of these changes, however, was significantly higher in acatalasemic mice than in wild-type mice. The level of catalase activity remained low in the acatalasemic peritoneum without the compensatory upregulation of glutathione peroxidase, but with an insufficient upregulation of superoxide dismutase activity in CG-injected mice. CONCLUSIONS: Acatalasemia, therefore, exacerbates oxidant tissue injury and induces the peritoneum to develop irreversible fibrosis which is the most important complication of peritoneal dialysis. This study suggests that catalase plays a crucial role in the defense against oxidant-mediated peritoneal injury in a mouse peritoneal fibrosis model.

Catalase deficiency may complicate urate oxidase (rasburicase) therapy.

Patients with low (inherited and acquired) catalase activities who are treated with infusion of uric acid oxidase because they are at risk of tumour lysis syndrome may experience very high concentrations of hydrogen peroxide. They may suffer from methemoglobinaemia and haemolytic anaemia which may be attributed either to deficiency of glucose-6-phosphate dehydrogenase or to other unknown circumstances. Data have not been reported from catalase deficient patients who were treated with uric acid oxidase. It may be hypothesized that their decreased blood catalase could lead to the increased concentration of hydrogen peroxide which may cause haemolysis and formation of methemoglobin. Blood catalase activity should be measured for patients at risk of tumour lysis syndrome prior to uric acid oxidase treatment.

Telmisartan inhibits both oxidative stress and renal fibrosis after unilateral ureteral obstruction in acatalasemic mice.

BACKGROUND: Reactive oxygen species are involved in many of the angiotensin II signalling pathways. We have thus investigated whether the angiotensin II type 1 (AT1) receptor antagonist, telmisartan, can inhibit the accelerated renal fibrosis and excess oxidative stress, which occurs after unilateral ureteral obstruction (UUO) in acatalasemic mice. METHODS: The effect of daily intraperitoneal injection of telmisartan (0.1-0.3 mg/kg body weight) on the renal tubulointerstitial injury induced by UUO has been studied in homozygous acatalasemic mutant mice (C3H/AnLCs b Cs b) and wild-type mice (C3H/AnLCs a Cs a). We evaluated the systemic blood pressure of the mice on the seventh day. In addition, the tubulointerstitial expression of collagens type I and type IV, the p22-, p47- and p67-phox subunits of NADPH oxidase, 4-hydroxy-2-nonenal, and 4-hydroxy-2-hexenal lipid peroxidation products were assessed by immunohistochemistry. The level of apoptosis was determined by terminal deoxynucleotidyl transferase nick end-labelling analysis, while the mRNA level of the p22-, p47- and p67-phox subunits was quantified by real-time PCR. The renal content of each of the antioxidant enzymes catalase, glutathione peroxidase and superoxide dismutase was determined by specific assay. RESULTS: Obstructed kidneys from acatalasemic mice exhibited increased tubulointerstitial deposition in dilated tubules of collagens type I and IV, lipid peroxidation products, and the p22/p47/p67-phox subunits of NADPH oxidase. The level of the p22/p47/p67-phox subunit mRNA, and of apoptosis in tubular epithelial cells, was also increased compared with those from wild-type kidneys. Treatment with telmisartan attenuated all of the changes and prevented renal fibrosis in a dose-dependent manner; despite the low dose (0.1 mg/kg). The treatment did not lower the systemic blood pressure. The catalase activity remained low in acatalasemic obstructed kidneys without compensatory upregulation of glutathione peroxidase or superoxide dismutase activity; the level of neither anti-oxidant enzymes in obstructed kidneys was affected by telmisartan. CONCLUSIONS: The AT1 receptor antagonist telmisartan ameliorated renal fibrosis after UUO by inhibition of oxidative stress, even under acatalasemic conditions.

Aumento de antioxidantes en sangre y de las concentraciones de selenio en pacientes negros con fase activa de vitíligo / Increased in total blood antioxidant status and selenium levels in black patients with active vitiligo

Antecedentes; El estrés oxidativo es un fenómeno importante en la muerte de los melanocitos en el vitiligo. Recientemente se ha encontrado una acumulación de peróxido de hidrógeno (H2O2) y niveles bajos de catalasa en la epidermis de pacientes con vitiligo. Se han visto pocas alteraciones de los antioxidantes en la sangre de pacientes con vitiligo, excepto una elevación del selenio. No se han realizado estudios sobre el estrés oxidativo hasta ahora, en pacientes con un fototipo VI de piel (clasificación de Fitzpatrick). Objetivo: Estudiar el estado antioxidante en la sangre de pacientes negros con vitíligo generalizado activo. Métodos: Se evaluaron el estado antioxidante total Randox, y las concentraciones de selenio, ferritina, transferrina, ceruloplasmina, tocoferol y retinal en muestras de sangre de los pacientes de piel negra de las indias Occidentales Francesas (de Martinica) con lesiones activas recientes de vitíligo y de 8 voluntarios sanos equiparados en edad y sexo. Resultados: El estado antioxidante total de la sangre y las concentraciones de selenio aumentaron significativamente en los pacientes con vitiligo, en comparación con los controles equiparados en sexo y edad (p<0,01 y p<0,02, respectivamente). No se modificaron significativamente las concentraciones en sangre de ferritina, transferrina, ceruloplasmina, retinol y tocoferol. Conclusiones: Este es el primer trabajo sobre el estado antioxidante global en sangre en el vitíligo. El aumento del estado antioxidante total en sangre observado en pacientes negros fue un resultado inesperado que necesita confirmarse y explicarse por otros estudios. El aumento espontáneo de las concentraciones de selenio podría ser interesante, puesto que este elemento ha sido recomendado en el tratamiento del vitíligo (AU)

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