RESUMO
Mitochondrial dysfunction caused by aberrant Complex I assembly and reduced activity of the electron transport chain is pathogenic in many genetic and age-related diseases. Mice missing the Complex I subunit NADH dehydrogenase [ubiquinone] iron-sulfur protein 4 (NDUFS4) are a leading mammalian model of severe mitochondrial disease that exhibit many characteristic symptoms of Leigh Syndrome including oxidative stress, neuroinflammation, brain lesions, and premature death. NDUFS4 knockout mice have decreased expression of nearly every Complex I subunit. As Complex I normally contains at least 8 iron-sulfur clusters and more than 25 iron atoms, we asked whether a deficiency of Complex I may lead to iron perturbations, thereby accelerating disease progression. Consistent with this, iron supplementation accelerates symptoms of brain degeneration in these mice, while iron restriction delays the onset of these symptoms, reduces neuroinflammation, and increases survival. NDUFS4 knockout mice display signs of iron overload in the liver including increased expression of hepcidin and show changes in iron-responsive element-regulated proteins consistent with increased cellular iron that were prevented by iron restriction. These results suggest that perturbed iron homeostasis may contribute to pathology in Leigh Syndrome and possibly other mitochondrial disorders.
Iron is a mineral that contributes to many vital body functions. But as people age, it accumulates in many organs, including the liver and the brain. Excess iron accumulation is linked to age-related diseases like Parkinson's disease. Too much iron may contribute to harmful chemical reactions in the body. Usually, the body has systems in place to mitigate this harm, but these mechanisms may fail as people age. Uncontrolled iron accumulation may damage essential proteins, DNA and fats in the brain. These changes may kill brain cells causing neurodegenerative diseases like Parkinson's disease. Mitochondria, the cell's energy-producing factories, use and collect iron inside cells. As people age, mitochondria fail, which is also linked with age-related diseases. It has been unclear if mitochondrial failure may also contribute to iron accumulation and associated diseases like Parkinson's. Kelly et al. show that mitochondrial dysfunction causes iron accumulation and contributes to neurodegeneration in mice. In the experiments, Kelly et al. used mice with a mutation in a key-iron processing protein in mitochondria. These mice develop neurodegenerative symptoms and die early in life. Feeding the mice a high-iron diet accelerated the animals' symptoms. But providing them with an iron-restricted diet slowed their symptoms and extended their lives. Low-iron diets also slowed iron accumulation in the animal's liver and reduced brain inflammation. The experiments suggest that mitochondrial dysfunction contributes to both iron overload and brain degeneration. The next step for scientists is understanding the processes leading to mitochondrial dysfunction and iron accumulation. Then, scientists can determine if they can develop treatments targeting these processes. This research might lead to new treatments for Parkinson's disease or other age-related conditions caused by iron overload.
Assuntos
Doença de Leigh , Doenças Mitocondriais , Camundongos , Animais , Doença de Leigh/genética , Doença de Leigh/patologia , Ferro/metabolismo , Doenças Neuroinflamatórias , Doenças Mitocondriais/patologia , Mitocôndrias/metabolismo , Complexo I de Transporte de Elétrons/metabolismo , Camundongos Knockout , Mamíferos/metabolismoRESUMO
Calixarenes are reportedly excellent activators that can remarkably improve the transport efficiencies of cell penetrating peptides. We employed eight calixarenes to systematically study the influence of structure on activation efficiency, which revealed that the scaffold, head group, and alkyl chain are all significant factors for activation efficiency by affecting affinities with the peptide and membrane.
Assuntos
Calixarenos/farmacologia , Peptídeos/metabolismo , Transporte Biológico/efeitos dos fármacos , Calixarenos/química , Avaliação Pré-Clínica de Medicamentos , Humanos , Estrutura MolecularRESUMO
OBJECTIVE: To evaluate the clinical efficacy and safety of Chinese drugs for the treatment of children's infectious mononucleosis (CIM). METHODS: Sixty CIM patients were assigned into the treated group and the control group, patients in the treated group were administered with Chinese herbal decoction, and those in the control group were treated with intravenous dripping of ganciclovir 10 mg/kg per day, for a treatment course of 14 days. RESULTS: The total effective rate was 96.0% in the treated group and 97.1% in the control group, showing insignificant difference between groups. The efficacy in the treated group was superior to that in the control group on the fever clearance time (3.0+/-1.5 days vs 4.9+/-3.9 days ) and the disappearance time of cervical lymph node swelling (0.8+/-1.0 score vs 1.5+/-1.2 score), showing statistical significance (all P<0.05). T-cell subsets were markedly improved in both groups after treatment. Adverse reaction occurred in four cases of the control group. CONCLUSION: Using Chinese herbs for clearing heat, removing toxin, activating blood circulation, and dissolving stasis is effective and safe for the treatment of CIM. It can effectively improve the clinical symptoms and shows a certain effect on immune regulation.
Assuntos
Mononucleose Infecciosa/tratamento farmacológico , Medicina Tradicional Chinesa , Antígenos CD/imunologia , Criança , Herpesvirus Humano 4/genética , Humanos , Mononucleose Infecciosa/imunologia , Reação em Cadeia da PolimeraseRESUMO
OBJECTIVE: To observe the clinic effect of combined use of berberin hydrochloride (Ber) with cyclosporine A (CsA) on the blood concentration of CsA in heart transplanted recipients. METHODS: The blood concentration of CsA, liver-renal function and blood lipids in 22 heart transplanted recipients, who received Ber-CsA combined therapy, were measured. RESULTS: The whole blood steady state concentration of CsA, C0 and C2, in recipients after being treated with Ber-CsA significantly increased than those before applying Ber-CsA (P < 0.01), with the mean increment of 26% and 18% respectively; the dosage of CsA used decreased in 21 patients by 25-100 mg/d; and the Ber-CsA showed no significant effect on liver-renal function or blood lipids (P > 0.05). CONCLUSION: Combined use of CsA with Ber could markedly increase the blood concentration of CsA in heart transplanted recipients and reduce the dosage of CsA required, save the fee for medical service, and shows no obvious adverse reaction.