Stem Cell Therapies for the Treatment of Diabetic Neuropathies: Future Perspectives.

BACKGROUND: Diabetic neuropathies (DN) are the most common complications in diabetic patients, affecting about 70% of them. Patients with DN may lose sensation in certain areas of the body, facilitating the onset of foot ulcers, as well as chronic pain. This is due to the progressive degeneration of nerve fibers, demyelination, and axonopathy. Recent studies about stem cell therapies for the treatment of DN show promising potential for tissue regeneration. Results with mesenchymal stem cells derived from various organs/tissues demonstrate great therapeutic potential considering their easy obtainment, as well as their immunomodulatory and pro-regenerative effects. However, problems such as cell transplant rejection, tumor formation, transplantation safety, and effectiveness still need to be solved. Developmental biology lacks detailed insights into some aspects of cell mechanisms, like the genetic components of cell growth or differentiation. These gaps can limit a rapid advance in stem cell therapy research and put it in the future a little bit farther from the expectations that have emerged in recent media. CONCLUSION: In the present review, we attempt to discuss the potential of most studied types of stem cells, their application for the treatment of experimental diabetic neuropathies and associated clinical manifestations including future perspectives around these themes.

More than kin, less than kind: one family and the many faces of diabetes in youth

SUMMARY Identification of the correct etiology of diabetes brings important implications for clinical management. In this report, we describe a case of a 4-year old asymptomatic girl with diabetes since age 2, along with several individuals in her family with different etiologies for hyperglycemia identified in youth. Genetic analyses were made by Sanger sequencing, laboratory measurements included HbA1c, lipid profile, fasting C-peptide, pancreatic auto-antibodies (glutamic acid decarboxylase [GAD], Islet Antigen 2 [IA-2], and anti-insulin). We found a Gly178Ala substitution in exon 5 of GCK gene in three individuals co-segregating with diabetes, and type 1 diabetes was identified in two other individuals based on clinical and laboratory data. One individual with previous gestational diabetes and other with prediabetes were also described. We discuss difficulties in defining etiology of hyperglycemia in youth in clinical practice, especially monogenic forms of diabetes, in spite of the availability of several genetic, laboratory, and clinical tools.

More than kin, less than kind: one family and the many faces of diabetes in youth.

Identification of the correct etiology of diabetes brings important implications for clinical management. In this report, we describe a case of a 4-year old asymptomatic girl with diabetes since age 2, along with several individuals in her family with different etiologies for hyperglycemia identified in youth. Genetic analyses were made by Sanger sequencing, laboratory measurements included HbA1c, lipid profile, fasting C-peptide, pancreatic auto-antibodies (glutamic acid decarboxylase [GAD], Islet Antigen 2 [IA-2], and anti-insulin). We found a Gly178Ala substitution in exon 5 of GCK gene in three individuals co-segregating with diabetes, and type 1 diabetes was identified in two other individuals based on clinical and laboratory data. One individual with previous gestational diabetes and other with prediabetes were also described. We discuss difficulties in defining etiology of hyperglycemia in youth in clinical practice, especially monogenic forms of diabetes, in spite of the availability of several genetic, laboratory, and clinical tools.

Morphological and functional aspects of acute kidney injury after fetal programing in the offspring of diabetic rats.

OBJECTIVE: To evaluate the effects of folic acid (FA)-induced renal failure in young offspring of diabetic mothers. METHODS: The offspring of streptozotocin-induced diabetic dams were divided into four groups: CC (controls receiving vehicle); DC (diabetics receiving vehicle); CA (controls receiving FA solution, 250 mg/kg) and DA (diabetics receiving FA solution, 250 mg/kg). Renal function tests and morphometry results were analyzed. RESULTS: An increase in creatinine and urea levels was observed in CA and DA groups at two and five months. FA administration caused a significant reduction in the number of glomeruli in the offspring of diabetic dams. The diabetes group treated with FA had fewer glomeruli compared to controls at two and five months. FA caused an increase in the area of the urinary space both in controls and offspring of diabetic dams at two and five months. The number of glomeruli and area of the urinary space at two months were negatively correlated. CONCLUSIONS: Fetal programing promotes remarkable changes in kidney morphology and function in offspring. We suggest that the morphological changes in the kidneys are more pronounced when fetal programing is associated with newly acquired diseases, e.g. renal failure induced by FA.

Transcutaneous electrical nerve stimulation and placental vascularization in cases of uterine blood flow restriction.

Studies report transcutaneous electrical nerve stimulation (TENS) as a treatment for placental insufficiency. To induce utero-placental insufficiency in rats, the uterine artery was ligated. Transcutaneous electrical nerve stimulation was applied with a frequency of 80 Hz, pulse duration of 200 µs, and low intensity. Placental blood vessels were analyzed after immunohistochemistry. The number, caliber and area occupied by placental vessels, fetal weight and length, and placental volume were lower in cases stimulated by TENS. The interaction between ligation and stimulation by TENS was associated with reduction of all these measurements, suggesting that TENS use during pregnancy may have harmful effects on intra-uterine development.

Dieta hiperlipídico-proteica utilizada para emagrecimento induz obesidade em ratos / Low-carbohydrate diet used for weight loss induces obesity in rats

OBJETIVO: Neste trabalho, analisa-se o efeito de dieta hiperlipídico-proteica com baixo teor de carboidrato sobre o peso corporal, peso de órgãos, consumo de ração, parâmetros bioquímicos e alterações histopatológicas no fígado de ratos. MÉTODOS: Foram utilizados 24 animais - 12 no grupo-controle e 12 no grupo-experimental - com peso médio de 160 gramas no início do experimento. Semanalmente, foram verificados o peso corporal e o consumo de ração, e ao final de oito semanas foram feitas as dosagens bioquímicas sanguíneas, pesagem de órgãos e análise histopatológica dos fígados. RESULTADOS: Os animais do grupo-experimental tiveram maior ganho de peso corporal e acumularam mais tecido adiposo que os animais do grupo-controle. Fígado, rins e baço não sofreram alterações quanto ao peso. Os animais que receberam dieta hiperlipídico-proteica tiveram um aumento na ingestão energética acumulada nas oito semanas do estudo. O grupo-experimental desenvolveu hiperglicemia e hipertrigliceridemia, aumento da fração lipoproteína de alta densidade do colesterol e da creatinina sérica quando comparado ao grupo-controle. Foi detectada esteatose hepática no grupo-experimental. CONCLUSÃO: Os resultados demonstraram que dietas pobres em carboidratos e ricas em gordura e proteínas podem acarretar alterações metabólicas prejudiciais ao organismo.

OBJECTIVE: This study analyzed the effect of a high fat, high protein and low carbohydrate diet on the body weight, organ weight, food intake and biochemical parameters of rats and the histopathological changes in their livers. METHODS: A total of 24 animals were used, 12 in the control group and 12 in the experimental group, with a mean weight of 160 grams at baseline. Body weight and food intake were collected weekly. At the end of 8 weeks, the animals were killed for the biochemical tests and weighing of organs and the livers were submitted to histopathological analysis. RESULTS: The animals in the experimental group gained more weight and accumulated more body fat than the animals in the control group. The weight of the liver, kidneys and spleen did not change. The animals fed the low carbohydrate diet consumed more calories during the 8 weeks of the study period. They also developed hyperglycemia and hypertriglyceridemia and presented high high-density lipoprotein cholesterol and serum creatinine. The experimental group also presented hepatic steatosis. CONCLUSION: The results show that low carbohydrate diets that are rich in fats and proteins may result in harmful metabolic changes in rats.

Influência da melatonina sobre o desenvolvimento corporal e ósseo de ratos / Ineluence of melatonin on body and bone development of rats

Objetivo: A glândula pineal produz o hormônio melatonina (MLT), que apresenta efeitos demonstrados sobre diversas células, entre elas os adipócitos e osteoblastos. Este trabalho objetivou verificar a influência da MLT no crescimento e desenvolvimento corporal e ósseo em ratos. Método e Resultados: Ratos Wistar machos foram submetidos a pinealectomia (PINX) ou cirurgia fictícia (CONTR) aos 5 dias do nascimento e estudados quanto ao peso e comprimento corporal; comprimento, espessura da tábua óssea e do disco epifisário da tíbia após 10, 20, 30, 60, 90 e 120 dias da operação. O peso dos animais PINX foi maior que o dos CONTR aos 100 e 120 dias. Os animais PINX tiveram ainda menor espessura da tábua óssea aos 60, 90 e 120 dias e menor espessura do disco epifisário, aos 90 e 120 dias após o procedimento cirúrgico, comparados aos animais CONTR. Conclusões: A falta de MLT resultou em aumento do peso corporal, provavelmente pela maior captação de ácidos graxos pelos adipócitos e redução da termogênese: menor espessura da tábua óssea e disco epifisario da tibia pela redução da atividade de condrócitos e osteoblastos. Estes efeitos poderiam ser diretos e/ou indiretos, e seu esclarecimento demanda mais estudos.

Five days old Wistar male rats were either pinealectomized or submitted to a sham operation. The animals were followed up to 120 days after surgery, being weighed and measured every 10 days. Groups of animals were then sacrificed at 10, 20, 30, 60, 90, and 120 days after the surgery. Thicknesses of the bone board and the epiphyseal plate of the tibia were measured. Results: (1) The average weight of the pinealectomized animals was greater than that of the control animals between 100 and 120 days after surgery; (2) There was no difference between the groups in the lengths of the body and of the back paw of the animals; (3) The length of the tibia was the same in both groups but the thickness of bone board after 60, 90, and 120 days of the surgery and the thickness of the epiphysial plate after 90 and 120 days of the surgery were smaller in the pinealectomized animals when compared with the control groups. Conclusion: the pineal gland, through the secretion of melatonin, participates in the bone development in rats by unknown mechanisms.

Análise quantitativa das células das ilhotas pancreáticas em ratos sob efeito de aloxana / Quantitative analysis of cells of the pancreatic islets in rats under effect of alloxan

No presente estudo, avaliamos a influência da aloxana sobre as células das ilhotas pancreáticas de ratos, realizando análise quantitativa das células α, β e δ. Foram utilizados 20 ratos (Rattus norveggicus), machos, da linha Wistar, distribuídos em dois grupos de 10 ratos, sendo um, grupo-controle e outro grupo experimental. Após jejum de 36 horas, foram administrados, por via endovenosa, 40 ml/Kg de monoidrato de aloxana e, cerca de 30 minutos após, foi oferecido alimento ao animal. Ao final de 10 dias de observaçäo, os animais foram sacrificados. Foram selecionadas amostras de diferentes regiões do pâncreas e submetidas a processamento histológico, tendo sido coradas com hematoxilina e eosina. Para o estudo imunohistoquímico, foram utilizados anticorpos antiinsulina, antiglucagon e anti-somatostatina. A análise quantitativa foi realizada em oito ilhotas pancreáticas, as mais representativas de cada animal. Os resultados foram considerados significativos, quando p<0,05. Houve reduçäo significativa do número de células β e aumento significativo, do número de células δ. Os resultados reforçam a afirmaçäo de que a aloxana tem açäo destrutiva sobre as células e exerce influência significativa sobre as células δ pancreáticas, o que já havia sido observado em outros estudos

Influência da glândula pineal sobre a ingestäo de água e NaCl em ratas normais e Ooforectomizadas / Influence of oophorectomy and pinealectomy on walter and NaCl ingestion by adults rats

Objetivo: avaliar a influência da pineal sobre a ingestäo de água e de NaCl em ratas normais e ooforectomizadas. Métodos: utilizaram-se 48 (n=48) ratas adultas, divididas ao acaso em quatro grupos: GI - mantidas sem manipulaçäo, servindo como controle (n=20); GII - submetidas à ooforectomia bilateral (n=8); GIII - submetidas à pinealectomia (n=12); GIV - submetidas à ooforectomia bilateral e à pinealectomia (n=8). A seguir, todos os animais foram mantidos em gaiolas individuais; após três semanas. Determinou-se diariamente a fase do ciclo por esfregaço vaginal e anotou-se diariamente o volume ingerido de água e NaCl a 0,25 M, por aproximadamente três meses. Resultados: 1) as ratas submetidas somente à pinealectomia apresentaram maior frequência da fase de estro, sendo que algumas entraram em estado de estro permanente; 2) o consumo de líquidos (água e soluçäo salina) näo se alterou durante as diferentes fases do ciclo estral; 3) as ratas do grupo submetido à ooforectomia tiveram maior consumo de água, sendo que a pinealectomia nesses animais restabeleceu o consumo normal da ágia; 4) os animais ooforectomizados e os ooforectomizados e pinealectomizados mostraram reduçäo do consumo médio de soluçäo salina. Conclusöes: os dados obtidos sugerem que a glândula pineal poderia modular a açäo dos esteróides ovarianos sobre a ingestäo de sal e água em ratas adultas.

Alterações metabólicas e da bioquímica plasmática após pinealectomia em ratos / Metabolic and biochemical changes after pialectomy in rats

A pineal, pela secreção de melatonina (MLT), está envolvida no controle do eixo hipotálamo-hipófise-gônadas, regulação de ritmos biológicos e sensibilidade tecidual à insulina. O presente estudo foi realizado para verificar a influência da pineal sobre parâmetros metabólicos e bioquímica plasmática em ratos. Ratos wistar machos (180- 200g) foram mantidos em gaiolas metabólicas por 10 dias para avaliação diária da ingestão de água e alimento, volume urinário e peso corporal. Ao final deste período, os animais foram anestesiados e submetidos à pinealectomia (n=10) ou cirurgia fictícia (n=10) e coleta de sangue para dosagens de glicose, colesterol, triglicérides, proteínas totais e eletrólitos (Na+, K+, Ca++, Cl-). Após 20 e 50 dias da cirurgia, os animais foram recolocados em gaiolas metabólicas para observação por 10 dias e coleta de sangue. Os resultados obtidos demonstram nos animais pinealectomizados: a) aumento da ingestão de alimento e do volume urinário; b) maior ganho de peso após 60 dias da cirurgia; c) elevação plasmática de glicose e colesterol e redução das proteínas totais. Os resultados indicam que a pinealectomia induz alterações metabólicas nos ratos gerando quadro que se assemelha ao diabetes mellitus tipo II que, provavelmente, ocorre pela ausência de melatonina e conseqüente diminuição da sensibilidade celular à insulina.

Pineal gland, through secretion of melatonin (MLT), is envolved in the control of hypothalamus-hypophisis-gonadas axis, regulation of biological rhythms and tissue sensibility to insulin. The present work was made in order to verify pineal influence on metabolic and plasmatic conditions in rats. Wistar male rats were kept in metabolic cages for daily registration of food and water ingestion and urinary output, during 10 days. At the end of this period blood sample was collected for plasmatic determination of glucosis, cholesterol, triglicerides, total protein and electrolytes (Na, K, Ca, Cl). The animals were then pinealectomized (n=10) or sham operated (n=10), and observed again after 20 and 50 days of surgery, during 10 days. Results obtained show that pinealectomized animals present: a) greater food ingestion and urinary output; b) increased body weight after 60 days of surgery; c) increase in plasmatic glucosis and cholesterol, and decrease in total protein concentrations. Data obtained suggest that pinealectomy induces metabolic alterations similar to diabetes mellitus type II, which probably occurs because the absence of MLT reduces tissue sensibility to insulin.

Development of a homemade laryngoscope for orotracheal intubation in rats / Preposiçäo de um laringoscópio (artesanal) para intubaçäo traqueal em ratos

Foi proposto um laringoscópio para intubaçäo orotraqueal sob visäo direta em ratos. O mesmo mostrou-se extremamente útil em cirurgia experimental, pois além da sua fácil fabricaçäo, permitiu uma intubaçäo orotraqueal em ratos de maneira prática, confiável e de fácil aprendizado. A intubaçäo traqueal como procedimento de rotina possibilitou a instalaçäo de ventilaçäo controlada mecânica, garantindo a ventilaçäo mesmo em cirurgia prolongadas