Variation in the relationship between fasting glucose and HbA1c: implications for the diagnosis of diabetes in different age and ethnic groups.

INTRODUCTION: Identify non-glycemic factors affecting the relationship between fasting plasma glucose (FPG) and glycated hemoglobin (HbA1c), in order to refine diabetes diagnostic criteria. RESEARCH DESIGN AND METHODS: Relationship between FPG-HbA1c was assessed in 12 531 individuals from 2001 to 2018 US National Health and Nutrition Examination Survey. Using a recently described method, FPG and HbA1c were used to calculate apparent glycation ratio (AGR) of red blood cells for different subgroups based on age, race, and gender. RESULTS: At an FPG of 7 mmol/L, black individuals had a higher HbA1c (p<0.001, mean: 50.2 mmol/mol, 95% CI (49.8 to 50.4)) compared with white individuals (47.4 mmol/mol (47.2 to 47.5)). This corresponds to NGSP (National Glycohemoglobin Standardization Program) units of 6.7% and 6.5% for black versus white individuals, respectively. Similarly, individuals under 21 years had lower HbA1c (p<0.001, 47.9 mmol/mol (47.7 to 48.1), 6.5%) compared with those over 50 years (48.3 mmol/mol (48.2 to 48.5), 6.6%). Differences were also observed between women (p<0.001, 49.2 mmol/mol (49.1 to 49.3), 6.7%) and men (47.0 mmol/mol (46.8 to 47.1), 6.5%). Of note, the difference in HbA1c at FPG of 7 mmol/L in black females over 50 and white males under 21 years was 5 mmol/mol (0.46%). AGR differences according to race (p<0.001), age (p<0.001), and gender (p<0.001) explained altered glucose-HbA1c relationship in the analyzed groups. CONCLUSIONS: FPG-HbA1c relationship is affected by non-glycemic factors leading to incorrect diagnosis of diabetes in some individuals and ethnic groups. Assessment of AGR helps understand individual-specific relationship between glucose levels and HbA1c, which has the potential to more accurately diagnose and manage diabetes.

Colonic epithelial hypoxia remains constant during the progression of diabetes in male UC Davis type 2 diabetes mellitus rats.

INTRODUCTION: Colonocyte oxidation of bacterial-derived butyrate has been reported to maintain synergistic obligate anaerobe populations by reducing colonocyte oxygen levels; however, it is not known whether this process is disrupted during the progression of type 2 diabetes. Our aim was to determine whether diabetes influences colonocyte oxygen levels in the University of California Davis type 2 diabetes mellitus (UCD-T2DM) rat model. RESEARCH DESIGN AND METHODS: Age-matched male UCD-T2DM rats (174±4 days) prior to the onset of diabetes (PD, n=15), within 1 month post-onset (RD, n=12), and 3 months post-onset (D3M, n=12) were included in this study. Rats were administered an intraperitoneal injection of pimonidazole (60 mg/kg body weight) 1 hour prior to euthanasia and tissue collection to estimate colonic oxygen levels. Colon tissue was fixed in 10% formalin, embedded in paraffin, and processed for immunohistochemical detection of pimonidazole. The colonic microbiome was assessed by 16S gene rRNA amplicon sequencing and content of short-chain fatty acids was measured by liquid chromatography-mass spectrometry. RESULTS: HbA1c % increased linearly across the PD (5.9±0.1), RD (7.6±0.4), and D3M (11.5±0.6) groups, confirming the progression of diabetes in this cohort. D3M rats had a 2.5% increase in known facultative anaerobes, Escherichia-Shigella, and Streptococcus (false discovery rate <0.05) genera in colon contents. The intensity of pimonidazole staining of colonic epithelia did not differ across groups (p=0.37). Colon content concentrations of acetate and propionate also did not differ across UCD-T2DM groups; however, colonic butyric acid levels were higher in D3M rats relative to PD rats (p<0.01). CONCLUSIONS: The advancement of diabetes in UCD-T2DM rats was associated with an increase in facultative anaerobes; however, this was not explained by changes in colonocyte oxygen levels. The mechanisms underlying shifts in gut microbe populations associated with the progression of diabetes in the UCD-T2DM rat model remain to be identified.

La suplementación con zinc favorece el crecimiento intrauterino en fetos de ratas diabéticas / Zinc supplementation favours intrauterine growth in diabetic rat fetuses

La deficiencia de zinc puede ser un factor mediador en los trastornos del crecimiento fetal en la descendencia de la gestante diabética. Se persiguió como objetivo determinar la influencia de un suplemento con zinc sobre la morfometría externa corporal y craneofacial en fetos de ratas diabéticas con hiperglucemias moderadas. Durante la gestación, ratas diabéticas y controles fueron suplementadas por vía oral con sulfato de zinc (50 mg/kg-pc) o no recibieron tratamiento. Los fetos descendientes del grupo diabético suplementado presentaron niveles similares a los controles en las variables de crecimiento somático determinadas. La suplementación con zinc a ratas diabéticas favoreció el crecimiento intrauterino en los fetos. Los resultados de esta investigación constituyen aportes para dilucidar los requerimientos de zinc que permitan prevenir los trastornos del crecimiento fetal en la descendencia de gestantes diabéticas.

Zinc deficiency may be a mediating factor in fetal growth disorders in the offspring of diabetic pregnant women. The objective was to determine the influence of a zinc supplement on external body and craniofacial morphometry in diabetic rat fetuses with moderate hyperglycemia. During gestation, diabetic and control rats were orally supplemented with zinc sulphate (50 mg/kg bw) or received no treatment. The fetuses descendants of the supplemented diabetic group had levels similar to the control ones in the determined somatic growth variables. Zinc supplementation to diabetic rats favoured intrauterine growth in fetuses. The results of this research constitute a contribution to elucidate zinc requirements that allow preventing fetal growth disorders in the offspring of diabetic pregnant women.

Embriopatía diabética y trastornos en el desarrollo reproductivo materno en ratas con diabetes pregestacional / Diabetic embryopathy and disorders in maternal reproductive development in rats with pregestational diabetes

Resumen OBJETIVOS: Determinar la repercusión de la diabetes pregestacional, con hiperglucemias moderadas, en el rendimiento reproductivo de la rata, crecimiento, desarrollo y morfología embrionaria en ratas Wistar. MATERIALES Y MÉTODOS: Estudio longitudinal, prospectivo y experimental efectuado en la Unidad de Investigaciones Biomédicas de la Universidad de Ciencias Médicas de Villa Clara, Cuba, en un modelo de diabetes moderada inducida neonatalmente a crías hembras de ratas Wistar de dos días de nacidas mediante la administración subcutánea de 100 mg/kg de peso corporal de estreptozotocina en una única dosis. A los 120 días de nacidas, las ratas de ambos grupos de experimentación (diabético y control) se aparearon con machos sanos. Se determinaron el peso y la glucemia durante la gestación y a los 11.5 días se practicó la cesárea. Se analizaron las variables del rendimiento reproductivo materno y de crecimiento, desarrollo y morfología externa en los embriones. Acorde con los desenlaces se utilizaron pruebas no paramétricas para el análisis de las variables cuantitativas y la prueba de χ2 para las variables cualitativas. RESULTADOS: La hiperglucemia moderada pregestacional provocó modificaciones en la ganancia de peso de la madre, la cantidad de reabsorciones, sitios de implantación, pérdidas preimplantación y eficiencia de implantación, así como en la morfología, talla y cantidad de somitas en los embriones. CONCLUSIONES: La diabetes moderada pregestacional alteró el rendimiento reproductivo materno y el crecimiento y desarrollo intrauterino de la descendencia en etapa embrionaria. La embriopatía diabética se manifestó, además, con malformaciones del sistema nervioso central.

Abstract OBJECTIVES: Diabetes mellitus is one of the most frequent disorders of pregnancy with adverse consequences for the mother and a high risk of diabetic embryopathy in the offspring. The objective of the research was to determine the effect of pregestational diabetes with moderate hyperglycemia on maternal reproductive performance, growth, development and embryonic morphology in Wistar rats. MATERIALS AND METHODS: Longitudinal, prospective and experimental study carried out at the Biomedical Research Unit of the University of Medical Sciences of Villa Clara, Cuba. A model of neonatally induced moderate diabetes was used in female Wistar rat pups two days old, by subcutaneous administration of 100 mg/kg of body weight of streptozotocin in a single dose. At 120 days after birth, rats from both experimental groups (diabetic and control) were mated with healthy males. Weight and glycemia were determined during pregnancy and at 11,5 days the cesarean section was performed. The variables of maternal reproductive performance and of growth, development and external morphology in the embryos were analyzed. According to the results, non-parametric tests were used for the analysis of the quantitative variables and the Chi-square test for the qualitative variables. RESULTS: Moderate pregestational diabetes caused changes in maternal weight gain, number of resorptions, implantation sites, preimplantation loss, and implantation efficiency, as well as in morphology, size, and number of somites in embryos. CONCLUSIONS: Moderate pregestational diabetes altered maternal reproductive performance and intrauterine growth and development of embryonic offspring. Diabetic embryopathy was also manifested by malformations of the central nervous system.

The impact of human umbilical cord-derived mesenchymal stem cells on the pancreatic function of type 2 diabetic mice and their regulatory role on NLRP3 inflammasomes / 中华内科杂志

Objective:To investigate the effect and regulation of umbilical cord-derived mesenchymal stem cells (UC-MSCs) on islets function and NOD-like receptor family, pyrin domain containing 3 (NLRP3) and autophagy in type 2 diabetic mellitus (T2DM) mice.Methods:Experimental study. Twenty, 8-week-old, male C57BL/6J mice were selected and divided into a normal control group ( n=5) and a high-fat feeding modeling group ( n=15). The model of T2DM was established by high-fat feeding combined with intraperitoneal injection of low-dose streptozotocin. After successful modeling, those mice were divided into a diabetes group ( n=7) and a UC-MSCs treatment group ( n=7). The UC-MSCs treatment group was given UC-MSCs (1×10 6/0.2 ml phosphate buffer solution) by tail vein infusion once a week for a total of 4 weeks; the diabetes group was injected with the same amount of normal saline, and the normal control group was not treated. One week after the treatment, mice underwent intraperitoneal glucose tolerance tests and intraperitoneal insulin tolerance tests, and then the mice were sacrificed to obtain pancreatic tissue to detect the expressions of interleukin-1β (IL-1β) and pancreatic and duodenal homeobox 1 (PDX-1) by immunofluorescence. The bone marrow-derived macrophages were stimulated with lipopolysaccharide and adenosine triphosphate (experimental group) in vitro, then co-cultured with UC-MSCs for 24 h (treatment group). After the culture, enzyme-linked immunosorbent assay was used to detect the secretion level of IL-1β in the supernatant, and immunofluorescence staining was used to detect the expression of NLRP3 inflammasome, and related autophagy proteins. Statistical analysis was performed using unpaired one-way analysis of variance, repeated measure analysis of variance. Results:In vivo experiments showed that compared with the diabetes group, the UC-MSCs treatment group partially repaired islet structure, improved glucose tolerance and insulin sensitivity (all P<0.05), and the expression of PDX-1 increased and IL-1β decreased in islets under confocal microscopy. In vitro experiments showed that compared with the experimental group, the level of IL-1β secreted by macrophages in the treatment group was decreased [(85.9±74.6) pg/ml vs. (883.4±446.2) pg/ml, P=0.001], the expression of NLRP3 inflammasome and autophagy-related protein P62 was decreased, and the expressions of microtubule-associated protein 1 light chain 3β (LC3) and autophagy effector Beclin-1 were increased under confocal microscopy. Conclusions:UC-MSCs can reduce the level of pancreatic inflammation in T2DM mice, preserving pancreatic function. This might be associated with the ability of UC-MSCs to inhibit the activity of NLRP3 inflammasomes in macrophages and enhance autophagy levels.

Efecto de la suplementación del zinc sobre el peso fetal en ratas diabéticas gestadas / Effect of zinc supplementation on fetal weight in pregnant diabetic rats

RESUMEN Introducción: La relación entre la deficiencia de Zn y la elevada incidencia de alteraciones en el crecimiento intrauterino en la diabetes materna aún no se ha dilucidado. En la literatura consultada no existen reportes del efecto de la suplementación con el micronutriente sobre el crecimiento fetal en modelos de diabetes con hiperglucemias moderadas. Objetivo: Determinar el efecto sobre el peso fetal de la suplementación con zinc a ratas con diabetes moderada durante la gestación. Métodos: Se utilizó un modelo de diabetes moderada inducida en ratas Wistar al segundo día de nacidas por inducción subcutánea con estreptozotocina (100mg/kg-pc). En la adultez las ratas sanas y diabéticas fueron apareadas con machos sanos. Según correspondiera recibieron durante 20 días de gestación un suplemento de sulfato de zinc (50mg/kg). Se estudiaron 395 fetos de cuatro grupos: fetos de ratas sanas sin suplemento, de ratas sanas suplementadas, de ratas diabéticas sin suplemento y de ratas diabéticas suplementadas. Los fetos se clasificaron en pequeños (PEG), adecuados (AEG) y grandes (GEG) para la edad gestacional. Resultados: La descendencia de las ratas diabéticas suplementadas mostró valores del peso fetal similares a ambos grupos sanos al término de la gestación, presentando menor porcentaje de fetos PEG y GEG, así como mayor porcentaje de AEG respecto al grupo diabético no suplementado. Conclusiones: La suplementación con Zn durante la gestación a ratas diabéticas con hiperglucemias moderadas causó efectos positivos sobre su descendencia al aumentar el porcentaje de fetos con peso adecuado.

ABSTRACT Introduction: the relationship between Zn deficiency and the high incidence of abnormal intrauterine growth in maternal diabetes has not yet been elucidated. There are no reports in the consulted literature of the effect of micronutrient supplementation on fetal growth in models of diabetes with moderate hyperglycemia. Objective: to determine the effect of zinc supplementation on fetal weight in rats with moderate diabetes during pregnancy. Methods: a model of mild diabetes was used in Wistar rats on the second day of birth by subcutaneous streptozotocin induction (100mg/kg-bw). As adults, healthy and diabetic rats were mated with healthy males. As appropriate, they received a zinc sulfate supplement (50mg/kg) during 20 days of gestation. A number of 395 fetuses from four groups were studied: fetuses from healthy rats without supplementation, from healthy rats supplemented, from diabetic rats without supplementation and from diabetic rats supplemented. Fetuses were classified as small (SGA), adequate (AGA), and large (LGA) for gestational age. Results: the offspring of the supplemented diabetic rats showed similar fetal weight values to both healthy groups at the end of pregnancy, having a lower percentage of SGA and LGA fetuses, as well as a higher percentage of AGA compared to the non-supplemented diabetic group. Conclusions: Zn supplementation during pregnancy in diabetic rats with moderate hyperglycemia had positive effects on their offspring by increasing the percentage of fetuses with adequate weight.

Incidencia de factores que influyen en complicaciones de diabetes mellitus / Incidence of factors influencing diabetes mellitus complications

Analizar la incidencia de factores que influyen en complicaciones de diabetes mellitus tipo II del Hospital IESS Latacunga. Método: Descriptiva observacional. Resultados: El 44% de las personas que padecen diabetes también presentan hipertensión, el 18% menciona que presenta colesterol alto, el 8 % colesterol bajo, el 28% triglicéridos altos y el 2% restante afirma tener los triglicéridos bajos. Conclusión: El género con mayor incidencia de la enfermedad es el femenino a una edad superior a los 50 años; en su mayoría los parecientes se aplican regularmente la insulina y los olvidos son considerados como frecuentes; además, las personas que presentan diabetes tienden a padecer adicionalmente hipertensión y triglicéridos altos, y el consumo excesivo de azúcar puede llegar a ocasionarles frecuentes visitas al hospital.

Objective: To analyze the incidence of factors influencing complications of type II diabetes mellitus in the Hospital IESS Latacunga. Methods: Descriptive observational study. Results: 44% of people with diabetes also have hypertension, 18% mentioned high cholesterol, 8% low cholesterol, 28% high triglycerides and the remaining 2% said they had low triglycerides. Conclusion: The gender with the highest incidence of the disease is female at an age above 50 years; the majority of the parecientes apply insulin regularly and forgetfulness is considered frequent; in addition, people with diabetes tend to additionally suffer from hypertension and high triglycerides, and the excessive consumption of sugar can cause them to have frequent hospital visits.

Metformin modulates the gut microbiome in a mice model of high-fat diet-induced glycolipid metabolism disorder.

INTRODUCTION: Metformin (MET) can regulate glucose and lipid levels, and the gut microbiota may be involved in the control of metabolism. We hypothesized that MET alleviates glucolipid metabolism disorder by modulating gut microbiota and microbial metabolites. RESEARCH DESIGN AND METHODS: A total of 24 male C57BL/6 J mice were equally divided into three groups (normal control, model control (MC), and MET-treated groups). Model mice were established by feeding a high-fat diet for 6 weeks. The MET-treated group was administered MET solution (2.5 g/100 mL, 250 mg/kg). Fecal samples were collected to characterize the microbiota system using metagenomic shotgun sequencing and gas chromatography-time of flight-mass spectrometry analysis. Phenotypic and biochemical indices were obtained for further correlation analysis. RESULTS: Compared with the MC group, MET reduced the levels of weight, glucose, areas under the glucose curve in the glucose tolerance test, triglyceride (TG), and total cholesterol (TC). A decreasing abundance of bacteria, including Parabacteroides distasonis, and an increasing abundance of bacteria, including Bacteroides vulgatus, were observed in the MET-treated group. The 2-deoxytetronic acid declined after MET intervention and was positively correlated with species over-represented in the MC group and negatively correlated with species enriched in the MET-treated group. Additionally, species enriched in the MET-treated group negatively correlated with glucose, areas under the glucose curve in the glucose tolerance test, and TGs. Further, the correlation between the differential metabolites, which decreased after MET intervention, and the phenotypic indices was positive. CONCLUSIONS: MET-induced restoration of intestinal homeostasis correlates with the amelioration of host glucolipid metabolism.

Interferon gene stimulating protein inhibitor improves leukocyte adhesion and glycolysis of retinal vascular endothelial cells / 中华眼底病杂志

Objective:To investigate the effects of interferon gene stimulating protein (STING) inhibitor (C176) on human retinal microvascular endothelial cells (hRMEC) under oxidative stress.Methods:An animal experimental study. In vivo experiment: 48 healthy male C57BL/6J mice were randomly divided into wild type mice group (WT group) and diabetes (DM) group, with 24 mice in each group. DM mice were induced by streptozotocin to establish DM model. After successful modeling, DM group was divided into DM+dimethyl sulfoxide (DMSO) group and DM+C176 group, with 12 mice in each group. The mice in the DM+DMSO group were intraperitoneally injected with DMSO at the dose of 50 mg/kg. Mice in DM+C176 group were intraperitoneally injected with STING inhibitor C176 750 nmol at the dose of 50 mg/kg. Four weeks after modeling, immunohistochemical staining, Western blot and real-time fluorescence quantitative polymerase chain reaction were used to detect the expression of STING in the retina of WT and DM mice. The leukocyte adhesion test was used to detect the number of leukocytes adhering to hRMEC in mice with WT, DM+DMSO and DM+C176 groups. In vitro experiment: hRMEC was randomly divided into conventional culture cell group (N group), dimethyl sulfoxide (DMSO) group (with DMSO intervention) and C176 group (with C176 intervention). The cells were induced by 150 μg/ml glycation end products for each group. In vitro leukocyte adhesion test combined with 4', 6-diamino-2-phenylindole staining was used to detect the number of leukocytes adhering to hRMEC. The adherent leukocytes were quantitatively analyzed by flow cytometry; H 2DCFDA/reactive oxygen species (ROS) fluorescence probe was used to detect ROS expression in cells; Seahorse XFe96 cell energy metabolism analyzer was used to measure the level of intracellular glycolysis. t-test was used to compare the two groups; single factor analysis of variance was used to compare the three groups. Results:In vivo experiment: compared with WT group, the expression level of STING ( t=73.248) and the relative expression amount of mRNA ( t=67.385) in the retina of DM group mice increased significantly ( P<0.05). Compared with WT group, the number of leukocytes adhering to the retinal vessels of mice in DM+DMSO group was significantly increased, while that in DM+C176 group was significantly decreased ( F=84.352, P<0.01). In vitro: compared with N group and DMSO group, the number of leukocyte adhesion on hRMEC in C176 group decreased significantly ( F=35.251, P<0.01). Compared with N group, the number of leukocytes adhering to hRMEC in DMSO group and C176 group decreased significantly ( F=26.374, P<0.01). The ROS level in hRMEC in C176 group was significantly lower than that in N group and C176 group ( F=41.362, P<0.01). Compared with N group and DMSO group, the glycolysis level of hRMEC in C176 group was significantly reduced, with a statistically significant difference ( F=68.741, P<0.01). Conclusion:Inhibiting the expression of STING in retinal vascular endothelial cells can improve the progress of DM by inhibiting leukocyte adhesion, ROS production and glycolysis level.

Efectos de la inyección neonatal de estreptozotocina sobre indicadores bioquímicos y de estrés oxidativo en ratas / Effects of neonatal injection of streptozotocin on biochemical indicators and oxidative stress in rats

Introducción: Debido a sus propiedades químicas, la estreptozotocina es uno de los agentes diabetogénicos más utilizados para generar modelos biológicos de diabetes, por lo que es necesario estudiar cuáles son sus efectos en el organismo del animal de laboratorio. Objetivo: Evaluar, en un periodo de 90 días, los efectos de la inyección neonatal de estreptozotocina en ratas Wistar sobre indicadores bioquímicos y de estrés oxidativo en hígado y riñón. Métodos: La diabetes fue inducida neonatalmente por 100 mg de estreptozotocina en ratas Wistar. Se realizaron determinaciones de glucemia, insulina e indicadores de estrés oxidativos en hígado y riñón en cinco animales por grupo a los días 5, 10, 20, 30, 60, 90 de nacidos. Resultados: En todas las intervenciones, la glucemia e insulina mostraron diferencias significativas en el grupo-STZ respecto al control. El valor máximo de hiperglucemia se observó al quinto día. La concentración de nitratos y nitritos en hígado fue mayor que en riñón. En comparación con el grupo control, en el tejido hepático del grupo-STZ la concentración de nitratos y nitritos resultó significativamente superior los días 10-20. En todas las intervenciones se detectó consumo de glutatión reducido en ambos órganos. En el hígado de las ratas STZ no se demostró daño a lípidos ni proteínas; sin embargo, en riñón se detectó daño significativo en ambas biomoléculas al quinto día. Conclusiones: Tanto la citotoxicidad de la estreptozotocina neonatal como las concentraciones de glucosa e insulina inducidas repercutieron negativamente sobre los indicadores de estrés oxidativo estudiados en tejido hepático y renal(AU)

Introduction: Streptozotocin is currently one of the most used diabetogenic agents to generate biological models of diabetes due to its chemical properties, so it is necessary to study the consequences of STZ for the organism of the laboratory animal. Objective: To evaluate in a period of 90 days the effects of neonatal injection of streptozotocin in Wistar rats on biochemical indicators and oxidative stress in liver and kidney. Methods: Diabetes was induced neonatally by 100 mg of streptozotocin in Wistar rats. Blood glucose, insulin and oxidative stress indicators in liver and kidney were determined in 5 animals per group at days 5, 10, 20, 30, 60, 90 of birth. Results: Blood glucose and insulin showed significant differences in the STZ-group respect to the control group in all interventions. The maximum value of hyperglycemia was observed on day-5. The concentration of nitrates and nitrites in liver was higher than in kidney. In liver tissue of the STZ-group, this indicator was significantly higher on days 10-20 compared to the control. In all interventions, reduced glutathione consumption was demonstrated in the STZ-group compared to control in both organs. In the liver of STZ rats no lipid or protein damage was demonstrated. However, in the kidney, significant damage in both biomolecules was detected in the STZ-group on day-5. Conclusions: Neonatal streptozotocin cytotoxicity as well as induced glucose and insulin concentrations had a negative impact on oxidative stress indicators studied in liver and kidney tissue(AU)

Malformaciones esqueléticas y alteraciones del crecimiento en fetos de ratas con diabetes moderada / Skeletal malformations and growth disturbances in fetuses of mild diabetic rats

Resumen Introducción. En la actualidad, la diabetes mellitus representa una de las condiciones médicas que complica el embarazo con mayor frecuencia, lo que afecta el crecimiento y el desarrollo fetal. Objetivo. Determinar las malformaciones esqueléticas y alteraciones en el crecimiento en fetos de ratas Wistar diabéticas. Materiales y métodos. Se utilizó un modelo de diabetes moderada inducida neonatalmente con estreptozotocina (STZ 100 mg/kg de peso corporal, por vía subcutánea) en ratas Wistar. En la adultez, las ratas sanas y diabéticas se aparearon con machos sanos de la misma edad y cepa. El día 20 de gestación se practicó la cesárea bajo anestesia. Se extrajeron los fetos, se pesaron y clasificaron como pequeños (PAG), adecuados (AEG) o grandes (GEG) para la edad gestacional. Los fetos seleccionados se procesaron para el análisis de anomalías esqueléticas y sitios de osificación. Resultados. En la descendencia de las ratas diabéticas, hubo un mayor porcentaje de fetos clasificados como pequeños o grandes y un menor porcentaje de fetos con peso adecuado; el promedio de peso fetal fue menor y había menos sitios de osificación. Se observaron alteraciones en la osificación de cráneo, esternón, columna vertebral, costillas y extremidades anteriores y posteriores; y también, hubo una correlación directa entre el peso y el grado de osificación fetal. Hubo malformaciones congénitas asociadas con la fusión y bifurcación de las costillas, así como cambios indicativos de hidrocefalia, como la forma de domo del cráneo, una amplia distancia entre los parietales y la anchura de las fontanelas anterior y posterior. Conclusión. La diabetes moderada durante la gestación altera el crecimiento y el desarrollo fetal, que se ve afectado tanto por macrosomía y la restricción del crecimiento intrauterino como por malformaciones esqueléticas.

Abstract Introduction: Currently, diabetes mellitus represents one of the medical conditions that more frequently complicates pregnancy affecting the fetus's growth and development. Objective: To determine the skeletal malformations and growth alterations in fetuses of diabetic Wistar rats. Materials and methods: We used a neonatally streptozotocin-induced mild diabetes model (STZ 100 mg/kg body weight - subcutaneously) in Wistar rats. In adulthood, healthy and diabetic rats were mated with healthy males of the same age and strain. On day 20 of gestation, a cesarean was performed under anesthesia. Fetuses were removed, weighed, and classified as small (SPA), adequate (APA), and large (LPA) for the gestational age. Selected fetuses were processed for skeletal anomaly and ossification sites analysis. Results: In the offspring of diabetic rats, there was a higher percentage of fetuses classified as small or large and a lower percentage of fetuses with adequate weight; the fetal weight mean was lower and there were fewer sites of ossification. Alterations were observed in the ossification of the skull, sternum, spine, ribs and fore and hind limbs; and also, there was a direct correlation between fetal weight and ossification degree There were congenital malformations associated with fusion and bifurcation of the ribs, as well as changes indicative of hydrocephaly, such as the dome shape of the skull, a wide distance between parietals, and the width of the anterior and posterior fontanels. Conclusion: Moderate diabetes during pregnancy alters fetal growth and development with macrosomia and intrauterine growth restriction, as well as skeletal malformations.

Cardioprotector effect of phosphodiesterase 5 inhibitors in experimental model for diabetes mellitus / Efeito cardioprotetor dos inibidores da fosfodiesterase 5 em modelo de diabetes mellitus experimental

Diabetes mellitus (DM) is considered a 21st century pandemic and is often associated with cardiovascular disease (CVD). The aim of this integrative review was to analyze the cardioprotective effects of phosdodiesterase-5 (PDE5i) inhibitors in experimental diabetes models. The articles were selected from the PubMed, SciELO and LILACS databases from 2014 to 2019. The following descriptors were used in combination with the Boolean operators: Diabetes mellitus experimental AND Phosphodiesterase 5 inhibitors; Diabetic cardiomyopathies AND Phosphodiesterase 5 inhibitors. An initial sample of 155 articles was obtained, of which six met the criteria for the synthesis of the review. The studies analyzed showed that treatment with PDE5i in experimental models, resulted in positive effects on cardiac function and metabolic parameters. Similar results have also been seen in humans. The reduction in cardiac hypertrophy, apoptosis of cardiomyocytes, pro-inflammatory factors and oxidative stress and the modulation of transcription factors involved in diabetes homeostasis, were prevalent among studies. The mechanisms of action involved in cardioprotection have not yet been fully elucidated, however the restoration of the activated cyclic guanosine monofate (cGMP) pathway by soluble guanylate cyclase (sGC) via nitric oxide (NO) was a common mechanism among the studies.

O Diabetes mellitus (DM) é considerado uma pandemia do século XXI e está frequentemente associado às doenças cardiovasculares (DCVs). O objetivo desta revisão integrativa foi analisar os efeitos cardioprotetores de inibidores da fosdodiesterase 5 (PDE5i) em modelos de diabetes experimental. Os artigos foram selecionados nas bases de dados PubMed, SciElo e LILACS no período de 2014 a 2019. Foram utilizados os seguintes descritores combinados com os operadores booleanos: Diabetes mellitus experimental AND Phosphodiesterase 5 inhibitors; Diabetic cardiomyopathies AND Phosphodiesterase 5 inhibitors. Foi obtida uma amostra inicial de 155 artigos, dos quais seis se enquadraram nos critérios para a síntese da revisão. Os estudos analisados evidenciaram que o tratamento com os PDEi5 em modelos experimentais, resultou em efeitos positivos sobre a função cardíaca e parâmetros metabólicos. Resultados semelhantes também foram observados em humanos. A redução da hipertrofia cardíaca, apoptose de cardiomiócitos, fatores pró-inflamatórios e estresse oxidativo e a modulação de fatores de transcrição envolvidos na homeostasia do diabetes, foram achados prevalentes entre os estudos. Os mecanismos de ação envolvidos na cardioproteção ainda não foram totalmente elucidados, contudo a restauração da via da guanosina monofato cíclica ativada (GMPc) pela Guanilato ciclase solúvel (GCs) via Óxido Nítrico (NO) foi um mecanismo comum entre os estudos.

Low basal metabolic rate as a risk factor for development of insulin resistance and type 2 diabetes.

INTRODUCTION: Identification of physiological factors influencing susceptibility to insulin resistance and type 2 diabetes (T2D) remains an important challenge for biology and medicine. Numerous studies reported energy expenditures as one of those components directly linked to T2D, with noticeable increase of basal metabolic rate (BMR) associated with the progression of insulin resistance. Conversely, the putative link between genetic, rather than phenotypic, determination of BMR and predisposition to development of T2D remains little studied. In particular, low BMR may constitute a considerable risk factor predisposing to development of T2D. RESEARCH DESIGN AND METHODS: We analyzed the development of insulin resistance and T2D in 20-week-old male laboratory mice originating from three independent genetic line types. Two of those lines were subjected to divergent, non-replicated selection towards high or low body mass-corrected BMR. The third line type was non-selected and consisted of randomly bred animals serving as an outgroup (reference) to the selected line types. To induce insulin resistance, mice were fed for 8 weeks with a high fat diet; the T2D was induced by injection with a single dose of streptozotocin and further promotion with high fat diet. As markers for insulin resistance and T2D advancement, we followed the changes in body mass, fasting blood glucose, insulin level, lipid profile and mTOR expression. RESULTS: We found BMR-associated differentiation in standard diabetic indexes between studied metabolic lines. In particular, mice with low BMR were characterized by faster body mass gain, blood glucose gain and deterioration in lipid profile. In contrast, high BMR mice were characterized by markedly higher expression of the mTOR, which may be associated with much slower development of T2D. CONCLUSIONS: Our study suggests that genetically determined low BMR makeup involves metabolism-specific pathways increasing the risk of development of insulin resistance and T2D.

Modulatory effect of baicalein on gene expression and activity of antioxidant enzymes in streptozotocin-nicotinamide induced diabetic rats

Oxidative stress plays the central role in the pathogenesis and progression of diabetic complications. The present study aims to investigate the beneficial effect of oral administration of flavone baicalein in streptozotocin-nicotinamide (STZ-NA) induced diabetic rats by measuring oxidative stress markers, antioxidant enzyme activities and expression analysis of antioxidant genes. Experimental diabetes was induced by a single intraperitoneal (i.p.) injection of STZ (55 mg /kg b.wt), 15 min after the i.p. administration of NA. At the end of the experimental period, thiobarbituric acid reactive substances (TBARS), activities of antioxidant enzymes and expression levels of superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) and glutathione peroxidase (GPx) were measured in diabetic rats along with serum biochemical parameters namely total cholesterol (TC), total triglyceride (TG), aspartate transaminase (AST) alanine transaminase (ALT) and glycosylated hemoglobin (HbA1c). Oral administration of baicalein (40 mg/kg b.wt/day) demonstrated a significant ameliorative effect on all studied biochemical and oxidative stress parameters. Biochemical findings were corroborated by qPCR expression analysis which showed significant upregulation of antioxidant genes in diabetic rats. These results suggest that baicalein supplementation may reduce diabetes and its complications by suppressing oxidative stress and enhancing gene expression and antioxidant enzyme activities in diabetic rats.

Effect of Empagliflozin, a Selective Sodium-Glucose Cotransporter 2 Inhibitor, on Kidney and Peripheral Nerves in Streptozotocin-Induced Diabetic Rats.

The effect of sodium-glucose cotransporter 2 inhibitors on peripheral nerves and kidneys in diabetes mellitus (DM) remains unexplored. Therefore, this study aimed to explore the effect of empagliflozin in diabetic rats. DM in rats was induced by streptozotocin injection, and diabetic rats were treated with empagliflozin 3 or 10 mg/kg. Following 24-week treatment, response thresholds to four different stimuli were tested and found to be lower in diabetic rats than in normal rats. Empagliflozin significantly prevented hypersensitivity (P<0.05) and the loss of skin intraepidermal nerve fibers, and mesangial matrix expansion in diabetic rats. Results of this study demonstrate the potential therapeutic effects of empagliflozin for the treatment of diabetic peripheral neuropathy and nephropathy.

Effect of Empagliflozin, a Selective Sodium-Glucose Cotransporter 2 Inhibitor, on Kidney and Peripheral Nerves in Streptozotocin-Induced Diabetic Rats

The effect of sodium-glucose cotransporter 2 inhibitors on peripheral nerves and kidneys in diabetes mellitus (DM) remains unexplored. Therefore, this study aimed to explore the effect of empagliflozin in diabetic rats. DM in rats was induced by streptozotocin injection, and diabetic rats were treated with empagliflozin 3 or 10 mg/kg. Following 24-week treatment, response thresholds to four different stimuli were tested and found to be lower in diabetic rats than in normal rats. Empagliflozin significantly prevented hypersensitivity (P < 0.05) and the loss of skin intraepidermal nerve fibers, and mesangial matrix expansion in diabetic rats. Results of this study demonstrate the potential therapeutic effects of empagliflozin for the treatment of diabetic peripheral neuropathy and nephropathy.

Efeito do diabetes mellitus tipo I na organização espacial das trabéculas ósseas: análise por meio do processo de esqueletonização / Effects of type I diabetes mellitus on the spatial organization of bone trabeculae: analysis by skeletonization

Introdução: Diabetes mellitus é uma doença metabólica que afeta vários órgãos-alvo, incluindo os ossos. Objetivo: Avaliar pelo método de esqueletonização o efeito do Diabetes mellitus tipo I (DM1) na microarquitetura de osso esponjoso. Material e métodos: Quatorze ratos Wistar foram divididos em: Saudável (S, n=7) e Diabético (D, n=7). O DM1 foi induzido por meio de injeção endovenosa de estreptozotocina no grupo D, sendo a confirmação da condição realizada por checagem do nível glicêmico. Os animais foram sacrificados após 35 dias da indução no grupo D, juntamente com os do grupo S. As epífises femorais foram seccionadas, removidas, desmineralizadas e incluídas em parafina. Dois cortes (5 µm) foram obtidos, corados em Hematoxilina e Eosina, e analisados ao Microscópio de Luz. Foi realizada a delimitação interativa das trabéculas ósseas, seguido pelo processo de binarização utilizando threshold global, feita por dois operadores distintos. Depois, foi realizado o processo de esqueletonização para acesso às características das trabéculas e da rede de interconexão entre elas. Os parâmetros avaliados foram: Área óssea em micrômetros quadrados (B.Ar, seguido pela proporção em porcentagem BV/TV), Índice de Modelo estrutural (SMI), Dimensão Fractal (FD), Número de trabéculas (Tb.N), Número de ramos (B.N), Número total de junções (Junc.N), Média de pontos terminais (End.p), Média de extensão de cada ramo (R.Le) e Número de junções triplas (Triple.points.N). Resultados: Houve diferença significante apenas no parâmetro SMI para os diferentes operadores (p<0,0001), sendo o mesmo retirado da análise entre diabetes vs saudável. Houve diferença significante na quantidade óssea, sendo maior no grupo S (0,46±0,09) comparado ao grupo D (0,41±0,07) (p=0,0082). Os demais parâmetros não mostraram diferença significante. Conclusão: Conclui-se que a área óssea no grupo saudável é maior em comparação ao DM1. Dentro das limitações deste estudo, parece que a distribuição espacial das trabéculas e suas características de interconexão não são alteradas no diabetes.

Introduction: Diabetes is a metabolic disease that affects several target-organs, including bone. Objective: Analyze the effects of Diabetes Mellitus Type 1 (DM1) on the trabecular bone microarchitecture by using the skeletonization process. Material and methods: Fourteen Wistar rats were divided in two groups: Health (S, n=7) and Diabetic (D, n=7). DM1 was induced with streptozotocin in D group, and glycemic levels were tested on peripheral blood samples. After 35 days, the animals were euthanized and had their femurs removed. The epiphysis were decalcified and embedded in paraffin. Five microns sections were stained in Hematoxylin and Eosin, and analyzed at the light microscope. Bone trabeculae were manually delimited, and then the binarization process with a global threshold was performed for each image. The whole process were conducted by two operators separately. Skeletonization was applied to binary images in order to evaluate the trabeculae characteristics and their network. Bone area (B.Ar), Bone proportion (BV/TV) Strucutre Model Index (SMI), Fractal Dimension (FD), Trabeculae number (Tb.N), Mean branches (B.N), Mean junction points (Junc.N), Mean End-points (End.p), Mean branches length (B.Le), and Mean triple points (Triple.points.N) were evaluated. Results: There was a significant difference only for SMI between different operators (p<0.0001), being this parameter excluded for the evaluation between health and diabetic groups. There was a significant difference between S and D for bone area, with S (0.46±0.09) higher than D (0.41±0.07) (p=0.0082). The other parameters analyzed were not significantly different. Conclusion: Bone trabecular area was higher in health compared with diabetes. Within the limitations of this study, one could suggest that there are no alterations of the spatial distribution of the trabeculae with their network and their inner structural characteristics.

[The protective effect of pigment epithelial-derived factor modified human umbilical cord mesenchymal stem cells on rats with diabetic retinopathy].

Objective: To investigate the effect of pigment epithelial-derived factor (PEDF) gene-modified human umbilical cord mesenchymal stem cells (MSC) on rats with diabetic retinopathy (DR). Methods: Experimental study. Human umbilical cord MSC were transfected by lentivirus packaging PEDF-MSC-green fluorescent protein (GFP) and GFP-MSC plasmid vectors, and the expression of PEDF and vascular endothelial growth factor (VEGF) was measured in the cell culture medium. Fifty adult male Sprague-Dawley rats were randomly divided into five groups: normal control group (group A), DR control group (group B), phosphate-buffered saline (PBS) treated group (group C), GFP-MSC treated group (group D) and PEDF-MSC-GFP treated group (group E), with 10 rats in each group. Streptozotocin was intraperitoneally injected to make early DR models. After four-month intervention, groups D and E were given intravitreal injection of GFP-MSC and PEDF-MSC-GFP; group C was given intravitreal injection of phosphate-buffered saline; groups A and B did not receive special treatment. The changes of retina in different groups were detected by hematoxylin and eosin staining, and the thickness of inner plexiform layer, inner nuclear layer and outer nuclear layer was measured by computer-based image analytical system. Immunohistochemistry was applied to observe PEDF and VEGF. Real-time quantitative polymerase chain reaction was used to detect the expression of PEDF and VEGF mRNA. Results: The expression of CD105, CD73 and CD90 was positive, while the expression of CD34, CD45, CD11b, CD19 and HLA-DR was negative. ELISA results showed that after transfection PEDF protein expression in the supernatant of PEDF-MSC (84.09±7.07) µg/L was higher than the control group (9.03±0.14) µg/L (P<0.05). At 2 weeks after intravitreal injection, green fluorescence was observed in the rat vitreous of groups D and E under a fluorescence microscope; no obvious green fluorescence was found in the retina. After 2 months of intravitreal injection, the thickness of inner plexiform layer in group E was significantly decreased; the thickness of inner nuclear layer and outer nuclear layer was higher (P<0.05). Immunohistochemical staining showed that 2 months after intravitreal treatment, the average optical density values of PEDF were improved, but the average optical density values of VEGF were decreased in group E (P<0.05). Real-time polymerase chain reaction showed that 2 months after treatment, the expression level of PEDF mRNA in group E was improved, but the expression level of VEGF mRNA was decreased (P<0.05). Conclusions: Intravitreal injection of PEDF-MSC could up-regulate the expression of PEDF and down-regulate the expression of VEGF in diabetic rats and may represent a novel candidate resource for cell therapy of DR nerve damage. (Chin J Ophthalmol, 2017, 53, 540-547).

Pulmonary oxidative stress in diabetic rats exposed to hyperoxia

Abstract Purpose: To evaluate the pulmonary oxidative stress in diabetic rats exposed to hyperoxia for 90 minutes. Methods: Forty male Wistar rats were divided into four groups, each one containing 10 animals, according to the oxygen concentration to which they were exposed: 21%, 50%, 75% and 100% (hyperoxia). In each group five animals were randomly induced to diabetes by means of at a dose of 55 mg/kg of streptozotocin (STZ). Results: Seventy two hours after diabetes induction, a significant difference was seen in blood glucose in the experimental groups in comparison with the control. In the experimental groups a significant difference was observed in the concentration of malondialdehyde (MDA) in lung tissue and blood plasma (p<0.05), except the 50% group. In the control group, significant differences in the MDA concentration in plasma and lung tissue were also observed (p<0.05), except the 75% group. The MDA concentration in lung tissue in comparison with the diabetic and non-diabetic groups showed a significant difference in the 21% group; however, no difference was seen in the 75 and 100% groups. Conclusion: In diabetic animals high oxygen concentrations (75 and 100%) do not appear to exert deleterious effects on lipid peroxidation in lung tissue.