Brain and skeletal muscle bioenergetic failure in familial hypobetalipoproteinaemia

Oxidative stress correlates with headache symptoms in fibromyalgia: coenzyme Q₁₀ effect on clinical improvement

BACKGROUND

Fibromyalgia (FM) is a chronic pain syndrome with unknown etiology and a wide spectrum of symptoms such as allodynia, debilitating fatigue, joint stiffness and migraine. Recent studies have shown some evidences demonstrating that oxidative stress is associated to clinical symptoms in FM of fibromyalgia. We examined oxidative stress and bioenergetic status in blood mononuclear cells (BMCs) and its association to headache symptoms in FM patients. The effects of oral coenzyme Q(10) (CoQ(10)) supplementation on biochemical markers and clinical improvement were also evaluated.

METHODS

We studied 20 FM patients and 15 healthy controls. Clinical parameters were evaluated using the Fibromyalgia Impact Questionnaire (FIQ), visual analogues scales (VAS), and the Headache Impact Test (HIT-6). Oxidative stress was determined by measuring CoQ(10), catalase and lipid peroxidation (LPO) levels in BMCs. Bioenergetic status was assessed by measuring ATP levels in BMCs.

RESULTS

We found decreased CoQ(10), catalase and ATP levels in BMCs from FM patients as compared to normal control (P < 0.05 and P < 0.001, respectively) We also found increased level of LPO in BMCs from FM patients as compared to normal control (P < 0.001). Significant negative correlations between CoQ(10) or catalase levels in BMCs and headache parameters were observed (r  = -0.59, P < 0.05; r  =  -0.68, P < 0.05, respectively). Furthermore, LPO levels showed a significant positive correlation with HIT-6 (r = 0.33, P<0.05). Oral CoQ(10) supplementation restored biochemical parameters and induced a significant improvement in clinical and headache symptoms (P < 0.001).

DISCUSSION

The results of this study suggest a role for mitochondrial dysfunction and oxidative stress in the headache symptoms associated with FM. CoQ10 supplementation should be examined in a larger placebo controlled trial as a possible treatment in FM.

Mitochondrial coupling in humans: assessment of the P/O2 ratio at the onset of calf exercise

Coupling of oxidation to ATP synthesis (P/O2 ratio) is a critical step in the conversion of carbon substrates to fuel (ATP) for cellular activity. The ability to quantitatively assess mitochondrial coupling in vivo can be a valuable tool for basic research and clinical purposes. At the onset of a square wave moderate exercise, the ratio between absolute amount of phosphocreatine split and O2 deficit (corrected for the amount of O2 released from the body O2 stores and in the absence of lactate production), is the mirror image of the P/O2 ratio. To calculate this value, cardiac output (Q), whole body O2 uptake (VO2), O2 deficit (O2(def)) and high-energy phosphates concentration (by 31P-NMR spectroscopy) in the calf muscles were measured on nine healthy volunteers at rest and during moderate intensity plantar flexion exercise (3.44 +/- 0.73 W per unit active muscle mass). Q and VO2 increased (from 4.68 +/- 1.56 to 5.83 +/- 1.59 l min(-1) and from 0.28 +/- 0.05 to 0.48 +/- 0.09 l min(-1), respectively), while phosphocreatine (PCr) concentration decreased significantly (22 +/- 6%) from rest to steady-state exercise. For each volunteer, "gross" O2(def) was corrected for the individual changes in the venous blood O2 stores (representing 49.9 +/- 9.5% of the gross O2(def)) yielding the "net" O2(def). Resting PCr concentration was estimated from the appropriate spectroscopy data. The so calculated P/O2 ratio amounted on average to 4.24 +/- 0.13 and was, in all nine subjects, very close to the literature values obtained directly on intact skeletal muscle. This unfolds the prospect of a non-invasive tool to quantitatively study mitochondrial coupling in vivo.

Randomized trial of the effects of simvastatin on cognitive functioning in hypercholesterolemic adults

PURPOSE

In our initial study of the potential effects of cholesterol-lowering interventions on cognitive functioning, treatment with lovastatin as compared with placebo caused performance decrements on several neuropsychological tests, whereas scores on other tests were unaffected. The current study was designed to confirm and extend those findings.

METHODS

The study comprised 308 hypercholesterolemic adults between 35 and 70 years of age. Employing a randomized double-blind design, we assigned participants to daily treatment with placebo, 10 mg of simvastatin, or 40 mg of simvastatin for 6 months. A neuropsychological test battery was administered to assess cognitive functioning at baseline and at the end of the treatment period.

RESULTS

A total of 283 subjects completed the study: 94 subjects on placebo, 96 taking 10 mg of simvastatin, and 93 taking 40 mg of simvastatin. Compared with placebo, decremental effects of simvastatin treatment were found on tests previously observed to be sensitive to statins (P = 0.008; difference in summary z scores = 0.18; 95% confidence interval [CI]: 0.07 to 0.29) and on tests not previously administered (P = 0.04; difference in summary z scores = 0.17; 95% CI: 0.05 to 0.29), but not on tests previously observed to be insensitive to statins (P = 0.84; difference in summary z scores = 0.02; 95% CI: -0.07 to 0.10). For the three tests specifically affected by simvastatin, effects on cognitive performance were small, manifest only as failure to improve during the 6 months of treatment (compared with placebo), and were confounded by baseline differences on one test.

CONCLUSION

This study provides partial support for minor decrements in cognitive functioning with statins. Whether such effects have any long-term sequelae or occur with other cholesterol-lowering interventions is not known.

Elevated hydroperoxide levels and antioxidant patterns in Papillon-Lefèvre syndrome

BACKGROUND

Since it has been found that reactive oxygen species seem to be involved in the pathogenesis of both periodontitis and hyperkeratotic syndromes, we studied a group of patients belonging to 3 generations of a family with different degrees of severity of Papillon-Lefèvre syndrome (PLS) to ascertain whether altered concentrations of the most important hydrophobic and hydrophilic plasma antioxidants as well as products of oxidative damage are present in PLS.

METHODS

Coenzyme Q (CoQ), vitamin E, glutathione (GSH), and uric acid were evaluated by high-performance liquid chromatography (HPLC) (supplied with electrochemical detector) techniques and hydroperoxides by a spectrophotometric method.

RESULTS

GSH and uric acid were in the range of reference values; CoQ was very low in both the child of the third generation and his mother, and these 2 subjects had the highest hydroperoxide levels. The child also had extremely low values of vitamin E. In general, all family members showed abnormally high hydroperoxide levels, with the exception of those members who are phenotypically healthy.

CONCLUSIONS

Since the subjects with the lowest hydroperoxide contents are phenotypically healthy, whereas the affected individuals presented lower antioxidant levels and very high hydroperoxide concentrations, it has been suggested that a specific antioxidant therapy could be a promising approach in treating some PLS subjects. Moreover, unexpected manifestations of heterozygosity in the child of the third generation were also detected.

Oxidative injury and inflammatory periodontal diseases: the challenge of anti-oxidants to free radicals and reactive oxygen species

In recent years, there has been a tremendous expansion in medical and dental research concerned with free radicals, reactive oxygen species, and anti-oxidant defense mechanisms. This review is intended to provide a critical, up-to-date summary of the field, with particular emphasis on its implications for the application of "anti-oxidant therapy" in periodontal disease. We have reviewed the nomenclature, mechanisms of actions, features, and sources of most common free radicals and reactive oxygen species, as well as analyzed the typical biological targets for oxidative damage. Based on a review of direct and indirect anti-oxidant host defenses, particularly in relation to the key role of polymorphonuclear neutrophils in periodontitis, we review current evidence for oxidative damage in chronic inflammatory periodontal disease, and the possible therapeutic effects of anti-oxidants in treating and/or preventing such pathology, with special attention to vitamin E and Co-enzyme Q.

Deficit of in vivo mitochondrial ATP production in patients with Friedreich ataxia

Friedreich ataxia (FRDA), the most common of the inherited ataxias, is an autosomal recessive degenerative disorder, characterized clinically by onset before the age of 25 of progressive gait and limb ataxia, absence of deep tendon reflexes, extensor plantar responses, and loss of position and vibration sense in the lower limbs. FRDA is caused by a GAA triplet expansion in the first intron of the FRDA gene on chromosome 9q13 in 97% of patients. The FRDA gene encodes a widely expressed 210-aa protein, frataxin, which is located in mitochondria and is severely reduced in FRDA patients. Frataxin function is still unknown but the knockout of the yeast frataxin homologue gene (YFH1) showed a severe defect of mitochondrial respiration and loss of mtDNA associated with elevated intramitochondrial iron. Here we report in vivo evidence of impaired mitochondrial respiration in skeletal muscle of FRDA patients. Using phosphorus magnetic resonance spectroscopy we demonstrated a maximum rate of muscle mitochondrial ATP production (V(max)) below the normal range in all 12 FRDA patients and a strong negative correlation between mitochondrial V(max) and the number of GAA repeats in the smaller allele. Our results show that FRDA is a nuclear-encoded mitochondrial disorder affecting oxidative phosphorylation and give a rationale for treatments aimed to improve mitochondrial function in this condition.