Gut Microbiota, Probiotics and Diabetes

Diabetes is a condition of multifactorial origin, involving several molecular mechanisms related to the intestinal microbiota for its development. In type 2 diabetes, receptor activation and recognition by microorganisms from the intestinal lumen may trigger inflammatory responses, inducing the phosphorylation of serine residues in insulin receptor substrate-1, reducing insulin sensitivity. In type 1 diabetes, the lowered expression of adhesion proteins within the intestinal epithelium favours a greater immune response that may result in destruction of pancreatic β cells by CD8+ T-lymphocytes, and increased expression of interleukin-17, related to autoimmunity. Research in animal models and humans has hypothesized whether the administration of probiotics may improve the prognosis of diabetes through modulation of gut microbiota. We have shown in this review that a large body of evidence suggests probiotics reduce the inflammatory response and oxidative stress, as well as increase the expression of adhesion proteins within the intestinal epithelium, reducing intestinal permeability. Such effects increase insulin sensitivity and reduce autoimmune response. However, further investigations are required to clarify whether the administration of probiotics can be efficiently used for the prevention and management of diabetes

Effect of lipectomy on the lipid metabolism of normal or obese rats

Introdução: A obesidade e uma doenca que ocorre como consequencia do desequilibrio no balanco entre a energia ingerida e a gasta para a manutencao de processos vitais. A obesidade possui prevalencia crescente, assumindo atualmente carater epidemico, sendo considerada um dos principais problemas de Saúde publica na sociedade moderna. Ela esta associada com aumento do risco de desenvolver diabetes mellitus, doencas vasculares, dislipidemias e inumeras outras doencas cronicas. A lipectomia por succao e um metodo bastante efetivo e seguro para reducao da adiposidade, porem varios pesquisadores verificaram que a reposicao do tecido adiposo pode ocorrer. Dados da literatura tem mostrado que o tecido adiposo e um orgao nao apenas de estoque energetico, mas tambem de producao e secrecao de varias substancias com acao local e sistemica, como fator de necrose tumoral a, interleucinas S e 8, elementos do sistema renina-angiotensina, leptina, metalotioneina e outros. OBJETIVO: Verificar os efeitos da lipectomia apos sete ou trinta dias da cirurgia sobre o metabolismo do figado, dos tecidos adiposos brancos retroperitoneal e epididimal, do tecido adiposo marrom interescapular e da carcaca de animais normais ou tomados obesos pela administracao neonatal de glutamato monossodico - MSG. METODOS: Ratos Wistar normais ou MSG, com 90 dias de vida, foram anestesiados com Ketamina e Xilazina intraperitonealmente. Em seguida foi feita uma incisao longitudinal mediana no abdomen expondo a cavidade peritoneal para retirada bilateral de parte dos tecidos adiposos retroperitoneal (RET) e epididimal (EPI). Sete ou trinta dias apos a lipectomia os animais foram sacrificados por decapitacao, e retirados, pesados, congelados a -70ºC e posteriormente processados o RET, EPI, tecido adiposo marrom interescapular (TAM) e o figado. RESULTADOS: O modelo de obesidade utilizado neste estudo - o MSG -foi eficaz em promover obesidade nos animais estudados. Apos sete dias da lipectomia verificamos principalmente aumento na taxa de lipogenese do RET, EPI e TAM e aumento na captacao de lipidio marcado pelos tecidos EPI e TAM nos animais MSG, alem de aumento da trigliceridemia nos grupos normal e MSG. Apos trinta dias da lipectomia verificamos aumento na taxa de...(au)BV UNIFESP: Teses e dissertaçõe

Dietary lipids alter adipokines gene expression:in vivo and in vitro study

Os lipídios da dieta estão correlacionados com a composição do tecido adiposo, etiologia da obesidade e o surgimento de patologias relacionadas à obesidade, como diabetes e estados crônicos de inflamação. Uma importante proteína secretada pelo tecido adiposo é a adiponectina, que possui propriedades antiaterogênicas e antidiabéticas. A diminuição dos níveis plasmáticos de adiponectina tem sido observada em pacientes com resistência a ação da insulina, obesidade, diabetes mellitus do tipo 11 e doenças coronarianas. A haptoglobina é uma proteína de fase aguda secretada pelo fígado e pelo tecido adiposo branco. Em pacientes obesos e diabéticos, os níveis plasmáticos de haptoglobina estão elevados, o que indica que estas condições são estados crônicos de inflamação moderada. O objetivo deste trabalho foi avaliar os efeitos de quatro dietas hiperlipídicas diferentes, enriquecidas com 17,5 por cento de óleo de soja, peixe, coco ou banha, sobre a expressão gênica de adiponectina e haptoglobina pelo tecido adiposo retroperitoneal (RET), epididimal (EPI) e subcutâneo (SUB) de camundongos alimentados por dois dias (tratamento agudo) ou oito semanas (tratamento crônico). Células adiposas da linhagem 3T3-L 1 foram tratadas por 48 horas com seis diferentes ácidos graxos: palmítico, linoléico, eicosapentaenóico (EPA), docosahexaenóico (DHA), láurico ou oléico, e analisadas quanto à expressão gênica de adiponectina e haptoglobina. Células adiposas SGBS foram tratadas por 24 horas com os mesmos ácidos graxos, além do ácido araquidônico, e a expressão gênica de seis diferentes adipocinas foi estudada. A expressão gênica de adiponectina foi menor no RET dos animais tratados agudamente com todas as dietas, no EPI de animais tratados cronicamente com dietas soja e coco, e em células 3T3-L 1 tratadas com os ácidos palmítico, linoléico, DHA e EPA. A expressão gênica de haptoglobina foi maior no RET e EPI dos animais tratados crônica e agudamente com banha, no EPI e SUB dos animais tratados cronicamente com dieta enriquecida com óleo de coco, e em células 3T3-L 1 tratadas com ácido palmítico. Em células SGBS, o tratamento com DHA e EPA elevou a expressão de leptina e IL-6. O tratamento com ácido palmítico elevou a expressão de IL-6 e não alterou a de leptina. O tratamento com ácido láurico elevou a expressão de IL-6 e diminuiu a de leptina. Os tipos de lipídios na dieta podem diferentemente modificar a expressão gênica de adiponectina e haptoglobina pelo tecido adiposo, sendo que estas respostas são tecido-específicas e dependentes da duração do tratamento. Estes resultados indicam que a ingestão de determinados ácidos graxos podem contribuir para o desenvolvimento de resistência a ação da insulina, aterosclerose e resposta inflamatória.BV UNIFESP: Teses e dissertaçõe

Lipid metabolism of monosodium glutamate obese rats after partial removal of adipose tissue

We analyzed the effects of partial fat pad removal on retroperitoneal and epididymal fat depots and carcass metabolism of control (C) and MSG-obese (M) rats. Three-month-old C and M male Wistar rats were submitted to either partial surgical excision of epididymal and retroperitoneal fat tissue (lipectomy, Q or sham surgery (S) and studied after 7 or 30 days. Retroperitoneal and epididymal tissue re-growth after lipectomy was not observed, as indicated by the low pads weight of the L groups. The lipolysis rate was stimulated in LC7 and LM7, probably due to surgical stress and low insulin levels. In LM7, but not in LC7, in vivo lipogenesis rate increased in retroperitoneal and epididymal fat tissue, as did the diet-derived lipid accumulation in epididymal fat tissue. Although these local increases were no longer present in LM30, this group showed a large increase in the percentage of small area adipocytes in both pads as well as increased carcass lipogenesis rate. The present data showed that the partial removal of fat depots affected the metabolism of control and MSG-obese rats differently. In the obese animals only, it stimulated both local and carcass lipogenesis rate as well as adipocyte differentiation, i.e. responses likely to favor excised tissue re-growth and/or compensatory growth of non-excised depots.Univ Fed Sao Paulo, Dept Fisiol, BR-04023060 Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Fisiol, BR-04023060 Sao Paulo, BrazilWeb of Scienc

Exercise Training in Rats Impairs the Replenishment of White Adipose Tissue after Partial Lipectomy

The aim of this study was to evaluate the effect of exercise training on the metabolism of rats following the partial removal of fat pads. Three-month-old male Wistar rats were subjected to the partial removal (L) of retroperitoneal white adipose tissue (RET) and epididymal white adipose tissue (EPI), or a sham operation (Sh). Seven days after surgery, both sets of rats were subdivided into exercised (LE or ShE) (swimming 90 min/day, 5 days/week, 6 weeks) and sedentary (LS or ShS) groups. Partial removal of the fat pads increased the lipogenesis rates in both the RET and EPI and decreased the weight and lypolysis rate of the EPI, while the RET weight was not significantly affected by lipectomy. In both lipectomized and sham-operated groups, exercise training caused a reduction in carcass lipid content, food intake, RET and EPI weights, and RET lipogenesis rate. On the other hand, the exercise training increased the percentage of diet-derived lipid accumulation in both tissues, either in sham and lipectomized rats. These results confirmed that regrowth is not uniform and depends on the particular fat pad that is excised. They also demonstrated that exercise training following the partial removal of fat pads modified adipose tissue metabolism, impaired the replenishment of adipose tissue, and decrease body adiposity

White Adipose Tissue Re-growth after Partial Lipectomy in High Fat Diet Induced Obese Wistar Rats

The effects of partial removal of epididymal (EPI) and retroperitoneal (RET) adipose tissues (partial lipectomy) on the triacylglycerol deposition of high fat diet induced obese rats were analyzed, aiming to challenge the hypothesized body fat regulatory system. Male 28-day-old wistar rats received a diet enriched with peanuts, milk chocolate and sweet biscuits during the experimental period. At the 90th day of life, rats were submitted to either lipectomy (L) or sham surgery. After 7 or 30 days, RET, EPI, liver, brown adipose tissue (BAT), blood and carcass were obtained and analyzed. Seven days following surgery, liver lipogenesis rate and EPI relative weight were increased in L. After 30 days, L, RET and EPI presented increased lipogenesis, lipolysis and percentage of small area adipocytes. L rats also presented increased liver malic enzyme activity, BAT lipogenesis, and triacylglycerol and corticosterone serum levels. The partial removal of visceral fat pads affected the metabolism of high fat diet obese rats, which leads to excised tissue re-growth and possibly compensatory growth of non-excised depots at a later time

Effects of Different Fatty Acids and Dietary Lipids on Adiponectin Gene Expression in 3T3-L1 Cells and C57BL/6J Mice Adipose Tissue

Obesity is positively correlated to dietary lipid intake, and the type of lipid may play a causal role in the development of obesity-related pathologies. A major protein secreted by adipose tissue is adiponectin, which has antiatherogenic and antidiabetic properties. The aim of this study was to evaluate the effects of four different high-fat diets (enriched with soybean oil, fish oil, coconut oil, or lard) on adiponectin gene expression and secretion by the white adipose tissue (WAT) of mice fed on a selected diet for either 2 (acute treatment) or 60 days (chronic treatment). Additionally, 3T3-L1 adipocytes were treated for 48 h with six different fatty acids: palmitic, linoleic, eicosapentaenoic (EPA), docosahexaenoic (DHA), lauric, or oleic acid. Serum adiponectin concentration was reduced in the soybean-, coconut-, and lard-enriched diets in both groups. Adiponectin gene expression was lower in retroperitoneal WAT after acute treatment with all diets. The same reduction in levels of adiponectin gene expression was observed in epididymal adipose tissue of animals chronically fed soybean and coconut diets and in 3T3-L1 cells treated with palmitic, linoleic, EPA, and DHA acids. These results indicate that the intake of certain fatty acids may affect serum adiponectin levels in mice and adiponectin gene expression in mouse WAT and 3T3-L1 adipocytes. The effects appear to be time dependent and depot specific. It is postulated that the downregulation of adiponectin expression by dietary enrichment with soybean oil or coconut oil may contribute to the development of insulin resistance and atherosclerosis