Molecular therapy for obesity and diabetes based on a long-term increase in hepatic fatty-acid oxidation.

UNLABELLED: Obesity-induced insulin resistance is associated with both ectopic lipid deposition and chronic, low-grade adipose tissue inflammation. Despite their excess fat, obese individuals show lower fatty-acid oxidation (FAO) rates. This has raised the question of whether burning off the excess fat could improve the obese metabolic phenotype. Here we used human-safe nonimmunoreactive adeno-associated viruses (AAV) to mediate long-term hepatic gene transfer of carnitine palmitoyltransferase 1A (CPT1A), the key enzyme in fatty-acid ß-oxidation, or its permanently active mutant form CPT1AM, to high-fat diet-treated and genetically obese mice. High-fat diet CPT1A- and, to a greater extent, CPT1AM-expressing mice showed an enhanced hepatic FAO which resulted in increased production of CO(2) , adenosine triphosphate, and ketone bodies. Notably, the increase in hepatic FAO not only reduced liver triacylglyceride content, inflammation, and reactive oxygen species levels but also systemically affected a decrease in epididymal adipose tissue weight and inflammation and improved insulin signaling in liver, adipose tissue, and muscle. Obesity-induced weight gain, increase in fasting blood glucose and insulin levels, and augmented expression of gluconeogenic genes were restored to normal only 3 months after AAV treatment. Thus, CPT1A- and, to a greater extent, CPT1AM-expressing mice were protected against obesity-induced weight gain, hepatic steatosis, diabetes, and obesity-induced insulin resistance. In addition, genetically obese db/db mice that expressed CPT1AM showed reduced glucose and insulin levels and liver steatosis. CONCLUSION: A chronic increase in liver FAO improves the obese metabolic phenotype, which indicates that AAV-mediated CPT1A expression could be a potential molecular therapy for obesity and diabetes.

Identificación de mutaciones en el gen CPT2 en un caso con déficit muscular de carnitina palmitoiltransferasa II / Identification of CPT2 gene mutations in a patient with muscular carnitine palmitoyltransferase II deficiency

Introducción: El déficit de carnitina palmitoiltransferasa II (CPT-II) se debe a mutaciones en el gen CPT2 y se asocia con 3 fenotipos. La forma adulta o muscular con crisis de mialgia y mioglobinuria es la más frecuente. Los fenotipos infantil y neonatal son multiorgánicos y de mayor gravedad. La mutación común en la forma adulta, p.S113L, no se ha descrito en casos de la variante neonatal. Se presenta un caso de forma adulta con mutaciones que previamente se han asociado a fenotipos diferentes. Paciente y métodos: Paciente de 22 años con episodios recurrentes de calambres musculares y orinas oscuras tras realizar esfuerzos prolongados de moderada intensidad, con una marcada elevación sérica de srm-creatincinasa (8.400 U/l) y mioglobina (2.800 ng/ml) y cuyo tejido muscular no mostró signos de miopatía. La actividad de CPT-II muscular se valoró radioquímicamente y el gen CPT2 se amplificó y secuenció en el secuenciador ABIPrism 310 (Applied Biosystems, Foster City, CA). La mutación p.R151Q se confirmó por reacción en cadena de la polimerasa (PCR)-fragmentos de restricción de longitud polimórfica (RFLP). Resultados: La actividad de CPT-II fue del 16% respecto del valor inferior de referencia. Se identificaron 2 mutaciones en heterocigosis en el gen CPT2: p.S113L y p.R151Q. Discusión: La mutación p.R151Q únicamente se ha descrito en homocigosis y en heterocigosis compuesta (p.R151Q y p.P227L) en formas graves, y previamente no se ha asociado p.S113L a una forma clínica grave, lo que sugiere que la expresión del alelo p.S113L podría compensar los efectos deletéreos de la expresión del alelo p.R151Q, dando lugar al fenotipo moderado observado en la paciente. © 2008 AEBM, AEFA y SEQC. Todos los derechos reservados(AU)

Introduction: Mutations in the CPT2 gene cause carnitine palmitoyltransferase (CPT-II) deficiency, which has been associated with three main phenotypes. The most frequent adult muscular form is characterized by recurrent episodes of myalgia and myoglobinuria. The infantile and neonatal variants are severe, multiorgan diseases. The commonest mutation, in the adult form, pS113L, has not been reported so far in neonatal cases. We report on an adult patient presenting with exercise intolerance who harboured mutations previously associated with diverse phenotypes. Patient and methods: A 22 year-old woman presented with recurrent episodes of muscle cramps and dark urine after prolonged exercise of moderate intensity. She showed elevated serum CK (8400 U/L) and myoglobin (2800 ng/mL) levels. Muscle biopsy did not reveal signs of myopathy. Muscle CPT-II enzyme activity was determined by a radiochemical method. CPT2 gene was amplified and sequenced in an ABIPrism 310 Genetic Analyzer (Applied Biosystems, Foster City, CA). The p.R151Q mutation was confirmed by PCR-RFLP analysis. Results: The activity of CPT-II was decreased (16% of the reference lower limit). Two heterozygous missense mutations were identified in the CPT2 gene: p.S113L and p.R151Q. Discussion: The p.R151Q mutation has been described in homozygous and compound heterozygous (p.R151Q and p.P227L) patients with the severe form. The p.S113L mutation has not been associated with ``severe mutations¿¿. We suggest that expression of the ``benign¿¿ p.S113L allele might counteract the deleterious effects of the p.R151Q allele, which may account for the milder phenotype observed in the patient(AU)

[Improvement in the regimen for combined CDDP and CPT-11 chemotherapy].

UNLABELLED: Combination therapy with cisplatin (CDDP) and irinotecan hydrochloride (CPT-11) is expected to be effective against refractory tumors. The antitumor effect of CPT-11 is believed to depend on the area under the concentration-time curve (AUC) of SN 38, which is a metabolite of the prodrug CPT-11. Of the major adverse effects of CPT-11, leukopenia is dependent on the AUC of CPT-11 and severe diarrhea is believed to be dependent on the peak concentration (Cmax) of SN 38. Considering these properties of CPT-11, we investigated the administration of a new regimen. METHOD: The subjects were patients with gynecological cancer who consented to intra-arterial [IA] infusion. The patients received CDDP (30 mg/m2 over 2 hours) concurrently with CPT-11 (40 mg/m2 over 24 hours) at 2-week intervals. Plasma concentrations of platinum and CPT-11 were measured before and after administration. To prevent binding of SN 38 to the large intestinal mucosa, we performed 1) alkalization, 2) detoxification of SN 38, and 3) clearance of the large intestine. RESULT: 1) A decrease in tumor diameter or negative conversion on cytology and reduced tumor marker levels were observed in patients receiving IA infusion. 2) No serious adverse reactions occurred, except grade 3 diarrhea in one patient given infusion at the initial dose. 3) The rate of conversion from CPT-11 to SN 38 was about 10%, which was higher than the 3% rate after standard 90-minute intra-venous [i.v.] infusion. 4) In the patients treated with IA infusion, CPT-11 levels in venous blood were one thirty-third of those in arterial blood. 5) Regarding the venous blood concentration of platinum when CDDP (30 mg/m2) was administered, the AUC of free platinum in patients given IA infusion was about 2.5 times that after i.v. infusion. CONCLUSION: The IA infusion treatment produced a good clinical response with good compliance.