Construction of a 10rolGLP-1-expressing glucose-lowing Saccharomyces cerevisiae by CRISPR/Cas9 technique / 生物工程学报

To develop a novel glucose-lowering biomedicine with potential benefits in the treatment of type 2 diabetes, we used the 10rolGLP-1 gene previously constructed in our laboratory and the CRISPR/Cas9 genome editing technique to create an engineered Saccharomyces cerevisiae strain. The gRNA expression vector pYES2-gRNA, the donor vector pNK1-L-PGK-10rolGLP-1-R and the Cas9 expression vector pGADT7-Cas9 were constructed and co-transformed into S. cerevisiae INVSc1 strain, with the PGK-10rolGLP-1 expressing unit specifically knocked in through homologous recombination. Finally, an S. cerevisiae strain highly expressing the 10rolGLP-1 with glucose-lowering activity was obtained. SDS-PAGE and Western blotting results confirmed that two recombinant strains of S. cerevisiae stably expressed the 10rolGLP-1 and exhibited the desired glucose-lowering property when orally administered to mice. Hypoglycemic experiment results showed that the recombinant hypoglycemic S. cerevisiae strain offered a highly hypoglycemic effect on the diabetic mouse model, and the blood glucose decline was adagio, which can avoid the dangerous consequences caused by rapid decline in blood glucose. Moreover, the body weight and other symptoms such as polyuria also improved significantly, indicating that the orally hypoglycemic S. cerevisiae strain that we constructed may develop into an effective, safe, economic, practical and ideal functional food for type 2 diabetes mellitus treatment.

Forced degradation of gliquidone and development of validated stability-indicating HPLC and TLC methods

Forced degradation studies of gliquidone were conducted under different stress conditions. Three degradates were observed upon using HPLC and TLC and elucidated by LC-MS and IR. HPLC method was performed on C18 column using methanol-water (85:15 v/v) pH 3.5 as a mobile phase with isocratic mode at 1 mL.min-1 and detection at 225 nm. HPLC analysis was applied in range of 0.5-20 µg.mL-1 (r =1) with limit of detection (LOD) 0.177 µg.mL-1. TLC method was based on the separation of gliquidone from degradation products on silica gel TLC F254 plates using chloroform-cyclohexane-glacial acetic acid (6:3:1v/v) as a developing system with relative retardation 1.15±0.01. Densitometric measurements were achieved in range of 2 -20 µg /band at 254 nm (r = 0.9999) with LOD of 0.26 µg /band. Least squares regression analysis was applied to provide mathematical estimates of the degree of linearity. The analysis revealed a linear calibration for HPLC where a binomial relationship for TLC. Stability testing and methods validation have been evaluated according to International Conference on Harmonization guidelines. Moreover, the proposed methods were applied for the analysis of tablets and the results obtained were statistically compared with those of pharmacopeial method revealing no significant difference about accuracy and precision.

Management of diabetes mellitus in individuals with chronic kidney disease: therapeutic perspectives and glycemic control

The purpose of this study was to evaluate the therapeutic options for diabetes treatment and their potential side effects, in addition to analyzing the risks and benefits of tight glycemic control in patients with diabetic kidney disease. For this review, a search was performed using several pre-defined keyword combinations and their equivalents: “diabetes kidney disease” and “renal failure” in combination with “diabetes treatment” and “oral antidiabetic drugs” or “oral hypoglycemic agents.” The search was performed in PubMed, Endocrine Abstracts and the Cochrane Library from January 1980 up to January 2015. Diabetes treatment in patients with diabetic kidney disease is challenging, in part because of progression of renal failure-related changes in insulin signaling, glucose transport and metabolism, favoring both hyperglycemic peaks and hypoglycemia. Additionally, the decline in renal function impairs the clearance and metabolism of antidiabetic agents and insulin, frequently requiring reassessment of prescriptions. The management of hyperglycemia in patients with diabetic kidney disease is even more difficult, requiring adjustment of antidiabetic agents and insulin doses. The health team responsible for the follow-up of these patients should be vigilant and prepared to make such changes; however, unfortunately, there are few guidelines addressing the nuances of the management of this specific population.

Uso de hipoglicemiantes orais em pacientes com Diabetes Mellitus gestacional / Oral hypoglycemic in patients with gestational Diabetes Mellitus

O Diabetes Mellitus Gestacional (DMG) é definido como intolerância a carboidratos com início ou diagnóstico durante a gestação. Em gestantes com DMG, é importante o controle da glicemia a fim de reduzir ou evitar efeitos adversos como abortamento, malformações congênitas e crescimento fetal anormal. Tradicionalmente, a insulina é usada como medicamento de escolha, segura para mãe e feto e eficaz no sentido de controlar os valores glicêmicos maternos. A Metformina é um hipoglicemiante oral que age aumentando a sensibilidade dos tecidos à insulinaNos estudos disponíveis, quando comparada à insulina, a Metformina mostra uma menor taxa de hipoglicemia neonatal grave, porém, não foi observada diferença significativa em relação a outros resultados perinatais, tal como prematuridade. A gliburida é um hipoglicemiante que aumenta a secreção de insulina pelas células beta pancreáticas. É uma droga bem tolerada e apresenta baixa taxa de hipoglicemia materna, em torno de 1,5% das pacientes. A gliburida mostrou eficácia semelhante à insulina em diversos estudos no controle glicemico. Mais estudos clínicos randomizados se fazem necessários no momento atual de discussão sobre os reais benefícios e riscos dessas drogas, a fim de definir seu papel efetivo no tratamento do DMG, consolidando ou não, sua recomendação e seu uso amplo.(AU)

Gestational Diabetes (GMD) is defined as carbohydrate intolerance with onset or first recognition during pregnancy. In pregnants, with GMD the glucose control is important to minimize the risk of miscarriage, fetal congenital malformations and macrossomia. Traditionally, insulin is used, since it does not cross the placenta, being considered safe for the woman and the fetus. Metformin is a hypoglycemic agent that acts as an insulin sensitizer, inhibits gluconeogenesis, suppresses hepatic glucose output and increase intestinal glucose absorption. It crosses the placenta, but it is not considered teratogenic. When compared with insulin, Metformin shows a lower incidence of severe neonatal hypoglycemia, with no difference in rates of other perinatal complications, as prematurity. Glyburide is a hypoglycemic that increases insulin secretion by pancreatic beta cells and sensitivity in peripheral tissues and reducing hepatic clearance of insulin. It shows similar efficacy of insulin on glucose control with a lower rate of maternal hypoglycemia, around 1.5% of patients. The glyburide showed similar efficacy to insulin in several studies in glycemic control. It is still suggested that the use of agent hypoglycemic on DMG can induce a lower maternal weight gain and more treatment adherence. More randomized clinical studies are required to ensure the real benefits and risks of these drugs, in order to define its use on GMD treatment.(AU)

Mechanism of Action of Azadirachta Indica Linn. (Neem) Aqueous Leaf Extract as Hypoglycaemic Agent.

To find out the mechanism of action of Azadirachta indica aqueous leaf extract (ALE) as hypoglycaemic agent. Materials and Methods: Overnight fasted albino rats of Wister strain of either sex were divided into 3 groups-a) Control (5% aqueous gum acacia suspension 5ml/kg, PO), b) Test (ALE-500mg/kg, PO) and c) Standard (glibenclamide 0.5mg/kg, PO). Blood glucose was estimated before administration of drugs and at 30min, 60min & 120min after the administration of drugs. For glycogen estimation also different animals were taken and divided into similar groups and after 1h of administration of drugs, the animals were killed and glycogen concentration from the liver, skeletal muscle and cardiac muscle were estimated. Results: The ALE produces a marked decrease in blood glucose level in normal rats. The glycogen content of liver, skeletal muscle and cardiac muscle was increased significantly (p<0.001) after 1h of administration of ALE as compare to control. Conclusion: ALE decreases blood glucose level and increases glycogen concentration in liver, skeletal muscle and cardiac muscle significantly. Increased glycogen synthesis is one of the important mechanisms responsible for its hypoglycemic action.

Diabetes melito tipo 1 e gestação: [revisão] / Type 1 diabetes mellitus and pregnancy: [review]

As gestações em mulheres com diabetes têm apresentado resultados que melhoraram dramaticamente nas últimas décadas, em razão dos progressos com a monitorização das glicemias e administração de insulina. A gravidez nas mulheres com diabetes tipo 1 está associada a aumento de risco tanto para o feto quanto para a mãe. Antes da concepção, a prioridade é normalizar a glicemia para prevenir malformações congênitas e abortamentos espontâneos. Com o progresso da gestação, a mãe tem um risco aumentado de hipoglicemias e cetoacidose. Mais tarde existe risco de piora na retinopatia, hipertensão induzida pela gestação, pré-eclâmpsia-eclâmpsia, infecções de trato urinário e poliidrâmnios. No final da gestação, existe o risco de macrossomia e morte súbita intra-uterina do feto. Todas essas complicações podem ser prevenidas ou, pelo menos, minimizadas pelo planejamento da gestação e pelo controle intensivo das oscilações das glicemias, mantendo-as próximo ao normal.

As a result of the advances in glucose monitoring and insulin administration, there has been a dramatic improvement in the outcomes of pregnancy in diabetic women over the past decades. Pregnancy in type 1 diabetic women is associated with an increase in risk both to the fetus and to the mother. The normalization of blood glucose in order to prevent congenital anomalies and spontaneous abortions is considered a priority. As the pregnancy progress, the mother is at an increased risk for hypoglycemia or diabetic ketoacidosis. Later in the pregnancy, she is at risk of accelerated retinopathy, pregnancy-induced hypertension and preeclampsia-eclampsia, urinary tract infection, and polyhydramnios. At the end of pregnancy, there is also an increased risk of macrosomia and sudden death of the fetus in uterus. All of these complications can be prevented or, at least, minimized with careful planning of the pregnancy and intensive tight glucose control.

A secreção residual do peptídeo C faz diferença no tratamento do diabetes melito tipo 1?: [revisão] / C-peptide residual secretion makes difference on type 1 diabetes management?: [review]

O diabetes melito tipo 1 (DM1) é uma doença crônica causada por destruição progressiva das células-beta das ilhotas pancreáticas, o que leva à insulinopenia e à hiperglicemia. Uma proporção significativa de pacientes acometidos pode apresentar manutenção de alguma função secretora por longos períodos, identificada clinicamente por meio da detecção de peptídeo C sérico. Há evidências de que isso possa trazer alguns benefícios, como redução do risco de complicações crônicas, maior facilidade em atingir o controle metabólico adequado e menor frequência de hipoglicemias graves. É possível que o próprio peptídeo C, atuando diretamente em tecidos-alvo, contribua para esses efeitos.

Type 1 diabetes is a chronic disease characterized by progressive destruction of the pancreatic beta cells, what leads to insulin deficiency and hyperglycemia. However, a significant secretory function may persist for long periods in a few patients, what is clinically evident through the detection of serum C peptide. This phenomenon might reduce the risk of chronic complications, severe hypoglycemias and allow easier metabolic control. It is possible that these advantages are caused, at least partially, by C peptide itself, acting directly in its target tissues.

Metformina e AMPK: um antigo fármaco e uma nova enzima no contexto da síndrome metabólica / Metformin and AMPK: an old drug and a new enzyme in the context of metabolic syndrome

A metformina é uma das drogas antidiabéticas orais mais prescritas mundialmente, entretanto seu mecanismo de ação permanece desconhecido. Os estudos do Diabetes Prevention Program Research Group demonstraram que tanto a administração de metformina como a mudança no estilo de vida (dieta e exercício físico) podem reduzir a incidência de diabetes melito tipo 2 (DM2). Uma possível conexão bioquímica entre essas duas terapias pode ser a proteína quinase ativada por AMP (AMPK). Essa enzima foi inicialmente descrita como um sensor energético celular, sendo ativada pelo exercício físico. Por outro lado, várias evidências experimentais indicam que a AMPK seja um alvo importante da ação da metformina. Este artigo discute as várias formas da regulação da AMPK, sugerindo um possível mecanismo para sua ativação pela metformina que envolve a formação de espécies reativas de nitrogênio. A ativação da AMPK determina ampla variedade de efeitos fisiológicos, incluindo o aumento da captação de glicose pelos músculos esqueléticos e aumento do catabolismo de lipídios, podendo ser interessante não apenas na prevenção e tratamento do DM2, mas também no contexto da síndrome metabólica. A descoberta da ativação da AMPK pela metformina faz dessa enzima importante alvo farmacológico.

Metformin is one of the most commonly prescribed oral antidiabetic agents worldwide. However, its mechanism of action remains unknown. The Diabetes Prevention Program Research Group studies have shown that metformin administration and lifestyle-intervention (diet and exercise) reduce the incidence of Diabetes Mellitus type 2 (DM2). A possible biochemical connection between both therapies may be the AMP-activated protein kinase (AMPK). This enzyme was originally described as a sensor of cellular energy status, being activated in exercise. On the other hand, several experimental evidences indicate that AMPK may be an important target of metformin action. This paper discusses various ways for AMPK regulation, suggesting a possible mechanism for its activation by metformin that involves the production of reactive nitrogen species. AMPK activation determines a wide variety of physiological effects, including enhanced glucose uptake by skeletal muscle and enhanced lipid catabolism. Thus, it may be a key player not only in the prevention and treatment of DM2, but also in the development of new treatments for obesity and the metabolic syndrome. The finding of AMPK activation by metformin draws attention to this enzyme as an important pharmacological target.

Insulin therapy--role beyond glucose control.

Larger studies had shown improved patient outcome and lower probability of coronary artery disease in insulin treated groups. The classical lipid abnormalities associated with type 2 diabetes are low HDL-cholesterol concentration and high triglyceride concentration. Insulin usage leads to a decrease in triglyceride concentration, primarily by its effect on the enzyme adipose tissue lipoprotein lipase. Insulin suppresses the enzyme, thereby controlling lipolysis in uncontrolled diabetes. Insulins therapy also improves the endothelial dysfunction especially in people with evident macrovascular complications. Though insulin is noted to increase adrenergic tone and may cause elevation of blood pressure, still patients with insulinoma do not have high blood pressure. Some studies suggest weight gain with insulin therapy, others contradict it. One study suggests that insulin does not affect treatment satisfaction. Insulin is known to improve the glycaemic scenario and also the insulin secretory pattern by reducing the glucotoxicity.

Vias de sinalizaçäo da insulina / Insulin signalizing ways

A insulina é um hormônio anabólico com efeitos metabólicos potentes. Os eventos que ocorrem após a ligaçäo da insulina säo específicos e estritamente regulados. Definir as etapas que levam à especificidade deste sinal representa um desafio para as pesquisas bioquímicas, todavia podem resultar no desenvolvimento de novas abordagens terapêuticas para pacientes que sofrem de estados de resistência à insulina, inclusive o diabetes tipo 2. O receptor de insulina pertence a uma família de receptores de fatores de crescimento que têm atividade tirosina quinase intrínseca. Após a ligaçäo da insulina o receptor sofre autofosforilaçäo em múltiplos resíduos de tirosina. Isto resulta na ati-vaçäo da quinase do receptor e conseqüente fosforilaçäo em tirosina de um a família de substratos do receptor de insulina (IRS). Deforma similar a outros fatores de crescimento, a insulina usa fosforilaçäo e interações proteína-proteína como ferramentas essenciais para transmitir o sinal. Estas interações proteína-proteína säo fundamentais para transmitir o sinal do receptor em direçäo ao efeito celular final, tais como translocaçäo de vesículas contendo transportadores de glicose (GLUT4) do pool intracelular para a membrana plasmática, ativaçäo da síntese de glicogênio e de proteínas, e transcriçäo de genes específicos.

Protein binding of glipizide using equilibrium dialysis technique: effects of hydrogen ion concentration, drug concentration and ionic strength

The objective of this research was to investigate the effects of hydrogen ion concentration, drug concentration and ionic strength on the binding affinity of glipizide to albumin protein. Different buffer solutions of different pH values (pH 6.7, 7.5 and 8.5), different drug concentrations (2.45 mg, 4.82 mg and 9.42 mg), and phosphate buffer solutions pH 7.5 of different ionic strength (0.1, 0.4 and 1.0) were prepared. The effects of pH, drug concentration and ionic strength on the amount of glipizide bounded to 0.25 g bovine albumin was investigated. As the pH of the solution was increased from pH 6.4 to pH 8.5, milligrams drug bounded to gram protein (r value) decreased from 8.2 mg to 3.84 mg/g protein. Also as the ionic strength of the solution was increased from 0.1 to 1.0, the r value decreased from 10.76 mg to 3.96 mg/g protein. However, the r value did not change significantly with increasing of drug from 2.45 mg to 9.42 mg/25 ml. The r value was 7.36 mg/g protein when concentration of the drug was 2.45 mg/25 ml and 7.4 mg/g protein when the concentration of the drug was 9.42 mg/25 ml. This study demonstrated that factors such as high pH and high ionic strength can alter drug-protein binding and consequently increase free drug in plasma and increase bioavailability of slightly water insoluble drug such as antidiabetic drugs.

Hipoglicemiantes orales sulfonilúricos / Oral sulfonylurea hypoglicemiants

Actualmente hay cinco agentes hipoglicemiantes en Perú, Clorpropamida, tolbutamida, gliburida, glipizida y gliclazida. Esta revisión examinará la farmacología de estos compuestos, sus efectos adversos, interacción con otras drogas y su lugar en el tratamiento de la Diabetes Mellitus