Targeting lipid peroxidation and mitochondrial imbalance in Friedreich's ataxia.

Friedreich's ataxia (FRDA) is an autosomal recessive disorder, caused by reduced levels of the protein frataxin. This protein is located in the mitochondria, where it functions in the biogenesis of iron-sulphur clusters (ISCs), which are important for the function of the mitochondrial respiratory chain complexes. Moreover, disruption in iron biogenesis may lead to oxidative stress. Oxidative stress can be the cause and/or the consequence of mitochondrial energy imbalance, leading to cell death. Fibroblasts from two FRDA mouse models, YG8R and KIKO, were used to analyse two different categories of protective compounds: deuterised poly-unsaturated fatty acids (dPUFAs) and Nrf2-inducers. The former have been shown to protect the cell from damage induced by lipid peroxidation and the latter trigger the well-known Nrf2 antioxidant pathway. Our results show that the sensitivity to oxidative stress of YG8R and KIKO mouse fibroblasts, resulting in cell death and lipid peroxidation, can be prevented by d4-PUFA and Nrf2-inducers (SFN and TBE-31). The mitochondrial membrane potential (ΔΨm) of YG8R and KIKO fibroblasts revealed a difference in their mitochondrial pathophysiology, which may be due to the different genetic basis of the two models. This suggests that variable levels of reduced frataxin may act differently on mitochondrial pathophysiology and that these two cell models could be useful in recapitulating the observed differences in the FRDA phenotype. This may reflect a different modulatory effect towards cell death that will need to be investigated further.

Glomerular and tubular functions in children with different forms of beta thalassemia.

BACKGROUND: Although there are many available data about renal involvement in patients with beta thalassemia major (TM), the changes in renal functions of other types, such as thalassemia intermedia (TI) and thalassemia minor (TMin), were reported less. Therefore, we aimed to evaluate renal tubular and glomerular functions in patients with three types of beta thalassemia. METHODS: This prospective case-control study was conducted on 118 beta-thalassemia patients (49 in TM, 18 in TI and 51 TMin) and 51 healthy controls. Glomerular functions [estimated glomerular filtration rate (GFR), serum cystatin C and urinary protein creatinine ratio] and tubular functions [fractioned sodium excretion (FENa), tubular reabsorption of phosphorus, urinary excretion of uric acid, levels of retinol-binding protein, alpha-1 macroglobulin (alpha-1M), and beta-2 microglobulin, calcium creatinine ratio] were assessed in all patients and controls. RESULTS: The mean ages of the groups and controls at presentation were similar. Although GFR was similar in all patients and control groups, serum levels of cystatin C in patients with TM and TI were significantly higher compared to TMin and controls. Alpha-1M, FENa, urinary excretion of uric acid, and urine protein/creatinine ratio in TM and TI groups were significantly higher than the others. Mean cystatin C level was also higher in patients with TMin compared the controls. However, there were no significant differences according to all tubular and other glomerular functions between TMin and control groups. CONCLUSIONS: Although all types of beta thalassemia patients should be closely monitored to prevent further decrease in renal functions, the patients with TI should be considered to have a higher risk of glomerular and tubular deterioration as well as TM.

Adipocytokine concentrations in children with different types of beta-thalassemia.

BACKGROUND: Beta-thalassemia is an inherited blood disorder. It results from the impaired production of ß-globin chains, leading to a relative excess of alpha-globin chains. Clinical severity separates this disease into three main subtypes: ß- thalassemia major, ß-thalassemia intermedia and ß-thalassemia minor, the former two being clinically more significant. Inflammatory processes may play an important role in some of the complications of thalassemia. Adipose tissue is one of the most important endocrine and secretory organs that release adipocytokines like adiponectin, resistin and visfatin. AIM: The aim of our study was to analyze adipocytokine concentrations (adiponectin, resistin and visfatin) in different types of ß-thalassemia patients and determine any possible correlations with disease severity. METHODS: We recruited 29 patients who were transfusion-dependent ß-thalassemia-major patients, 17 patients with ß-thalassemia intermedia, 30 ß-thalassemia minor patients. The control group consisted of 30 healthy children. Anthropometric measurements, complete blood count, biochemical parameters, serum concentrations of adiponectin, resistin, visfatin were performed for all subjects. RESULTS: Resistin and visfatin concentrations were significantly higher in ß-thalassemia minor patients than in controls. Adiponetin, resistin and visfatin concentrations were significantly higher in both ß-thalassemia intermedia and major patients than in controls. The concentrations of adiponectin, resistin and visfatin were significantly higher in both ß-thalassemia intermedia and major patients than in ß-thalassemia minor patients. There was no significant difference between ß-thalassemia intermedia and ß-thalassemia major patients for adipocytokines concentrations. CONCLUSION: We speculate that these adipocytokines may play a role in the development of complications in ß-thalassaemia.