RESUMO
AIMS: To investigate the pharmacodynamics, efficacy and safety of empagliflozin as adjunct to insulin in patients with type 1 diabetes. METHODS: A total of 75 patients with glycated haemoglobin (HbA1c) concentrations of ≥7.5 to ≤10.5% (≥58 to ≤91 mmol/mol) were randomized to receive once-daily empagliflozin 2.5 mg, empagliflozin 10 mg, empagliflozin 25 mg, or placebo as adjunct to insulin for 28 days. Insulin dose was to be kept as stable as possible for 7 days then adjusted, at the investigator's discretion, to achieve optimum glycaemic control. The primary exploratory endpoint was change from baseline in 24-h urinary glucose excretion (UGE) on day 7. RESULTS: Empagliflozin significantly increased 24-h UGE versus placebo on days 7 and 28. On day 28, adjusted mean differences with empagliflozin versus placebo in changes from baseline in: HbA1c were -0.35 to -0.49% (-3.8 to -5.4 mmol/mol; all p < 0.05 vs. placebo); total daily insulin dose -0.07 to -0.09 U/kg (all p<0.05 vs placebo); and weight were -1.5 to -1.9 kg (all p < 0.001 vs. placebo). In the placebo, empagliflozin 2.5, 10 and 25 mg groups, respectively, adverse events were reported in 94.7, 89.5, 78.9 and 100.0% of patients, and the rate of symptomatic hypoglycaemic episodes with glucose ≤3.0 mmol/l not requiring assistance was 1.0, 0.4, 0.5 and 0.8 episodes per 30 days. CONCLUSIONS: In patients with type 1 diabetes, empagliflozin for 28 days as adjunct to insulin increased UGE, improved HbA1c and reduced weight with lower insulin doses compared with placebo and without increasing hypoglycaemia.
Assuntos
Compostos Benzidrílicos/administração & dosagem , Diabetes Mellitus Tipo 1/tratamento farmacológico , Glucosídeos/administração & dosagem , Hipoglicemiantes/administração & dosagem , Insulina/administração & dosagem , Adulto , Áustria , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/urina , Relação Dose-Resposta a Droga , Método Duplo-Cego , Quimioterapia Combinada , Feminino , Alemanha , Hemoglobinas Glicadas/efeitos dos fármacos , Glicosúria/urina , Humanos , Hipoglicemia/induzido quimicamente , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Redução de Peso/efeitos dos fármacosRESUMO
We report the identification, cDNA cloning, and molecular characterization of a novel, constitutive nucleolar protein. The cDNA-deduced amino acid sequence of the human protein defines a polypeptide of a calculated mass of 61.5 kDa and an isoelectric point of 9.9. Inspection of the primary sequence disclosed that the protein is a member of the family of "DEAD-box" proteins, representing a subgroup of putative ATP-dependent RNA helicases. ATPase activity of the recombinant protein is evident and stimulated by a variety of polynucleotides tested. Immunolocalization studies revealed that protein NOH61 (nucleolar helicase of 61 kDa) is highly conserved during evolution and shows a strong accumulation in nucleoli. Biochemical experiments have shown that protein NOH61 synthesized in vitro sediments with approximately 11.5 S, i.e., apparently as homo-oligomeric structures. By contrast, sucrose gradient centrifugation analysis of cellular extracts obtained with buffers of elevated ionic strength (600 mM NaCl) revealed that the solubilized native protein sediments with approximately 4 S, suggestive of the monomeric form. Interestingly, protein NOH61 has also been identified as a specific constituent of free nucleoplasmic 65S preribosomal particles but is absent from cytoplasmic ribosomes. Treatment of cultured cells with 1) the transcription inhibitor actinomycin D and 2) RNase A results in a complete dissociation of NOH61 from nucleolar structures. The specific intracellular localization and its striking sequence homology to other known RNA helicases lead to the hypothesis that protein NOH61 might be involved in ribosome synthesis, most likely during the assembly process of the large (60S) ribosomal subunit.
Assuntos
Nucléolo Celular/química , RNA Helicases/química , Adenosina Trifosfatases/metabolismo , Sequência de Aminoácidos , Animais , Western Blotting , Linhagem Celular , Nucléolo Celular/metabolismo , Centrifugação com Gradiente de Concentração , Cromatografia em Gel , Clonagem Molecular , RNA Helicases DEAD-box , Células HeLa , Humanos , Imuno-Histoquímica , Microscopia de Fluorescência , Microscopia Imunoeletrônica , Dados de Sequência Molecular , Peso Molecular , Oócitos , RNA Helicases/isolamento & purificação , Ribossomos/química , Transfecção , Xenopus laevisRESUMO
SF3b(155) is an essential spliceosomal protein, highly conserved during evolution. It has been identified as a subunit of splicing factor SF3b, which, together with a second multimeric complex termed SF3a, interacts specifically with the 12S U2 snRNP and converts it into the active 17S form. The protein displays a characteristic intranuclear localization. It is diffusely distributed in the nucleoplasm but highly concentrated in defined intranuclear structures termed "speckles," a subnuclear compartment enriched in small ribonucleoprotein particles and various splicing factors. The primary sequence of SF3b(155) suggests a multidomain structure, different from those of other nuclear speckles components. To identify which part of SF3b(155) determines its specific intranuclear localization, we have constructed expression vectors encoding a series of epitope-tagged SF3b(155) deletion mutants as well as chimeric combinations of SF3b(155) sequences with the soluble cytoplasmic protein pyruvate kinase. Following transfection of cultured mammalian cells, we have identified (i) a functional nuclear localization signal of the monopartite type (KRKRR, amino acids 196--200) and (ii) a molecular segment with multiple threonine-proline repeats (amino acids 208--513), which is essential and sufficient to confer a specific accumulation in nuclear speckles. This latter sequence element, in particular amino acids 208--440, is required for correct subcellular localization of SF3b(155) and is also sufficient to target a reporter protein to nuclear speckles. Moreover, this "speckle-targeting sequence" transfers the capacity for interaction with other U2 snRNP components.