Babies with gastroschisis have high morbidity, which is associated with inflammatory bowel injury caused by exposure to amniotic fluid. The objective of this study was to identify components of the inflammatory response in the intestine and liver in an experimental model of gastroschisis in rats. The model was surgically created at 18.5 days of gestation. The fetuses were exposed through a hysterotomy and an incision at the right of the umbilicus was made, exposing the fetal bowel. Then, the fetus was placed back into the uterus until term. The bowel in this model had macro- and microscopic characteristics similar to those observed in gastroschisis. The study was conducted on three groups of 20 fetuses each: gastroschisis, control, and sham fetuses. Fetal body, intestine and liver weights and intestine length were measured. IL-1β, IL-6, IL-10, TNF-α, IFN-γ and NF-kappaB levels were assessed by ELISA. Data were analyzed statistically by ANOVA followed by the Tukey post-test. Gastroschisis fetuses had a decreased intestine length (means ± SD, 125 ± 25 vs 216 ± 13.9; P < 0.005) and increased intestine weight (0.29 ± 0.05 vs 0.24 ± 0.04; P < 0.005). Intestine length correlated with liver weight only in gastroschisis fetuses (Pearson’s correlation coefficient, r = 0.518, P = 0.019). There were no significant differences in the concentrations of IL-1β, TNF-α or IFN-γ in the intestine, whereas the concentration of NF-kappaB was increased in both the intestine and liver of fetuses with gastroschisis. These results show that the inflammatory response in the liver and intestine of the rat model of gastroschisis is accompanied by an increase in the amount of NF-kappaB in the intestine and liver.

O estímulo mecânico sabidamente provoca deformação de proteínas da matriz extracelular e da célula óssea, as quais se tornam ativas e sinalizam reações intracelulares que determinam o aumento da massa óssea. Estudos apontam a quinase de adesão focal (FAK) como uma proteína fundamental na sinalização da deformação celular causada pelo estímulo mecânico no osso, mas há necessidade de estudos in vivo que comprovem esse papel. Objetivos - Com o ultra-som de baixa potência, investigar a influência do estímulo mecânico na expressão da FAK no osso, e a possibilidade de detectar proteínas envolvidas com a proliferação celular óssea e muscular esquelética. Material e Métodos - Tíbias e fíbulas de ratos foram estimuladas com ultra-som de baixa potência durante 20 min/uma vez ao dia, por períodos de 7, 14 e 21 dias. O grupo controle não foi estimulado. Cada grupo continha 7 ratos. Quinze horas após o último estímulo, a tíbia e a fíbula foram retiradas para realização de immunoblotting, utilizando anticorpos específicos para identificar FAK, FAK-Tyr(P)-397, extracellular signal-regulated kinase-2 (ERK-2), ERK-1/2-Tyr(P)-204, insulin receptor substrate-1 (IRS-1) e IRS-2. O músculo esquelético da região estimulada foi extraído e submetido ao mesmo procedimento. Resultados - Analisando-se os resultados de immunoblotting comparativamente com o grupo controle, não foram detectadas FAK e FAK-Tyr(P)-397 no tecido ósseo, enquanto ERK-2, ERK-1/2-Tyr(P)-204, IRS-1 e IRS-2 foram identificados. No músculo esquelético, todas as proteínas estudadas foram identificadas, exceto IRS-2. Discussão e Conclusão: Os resultados sugerem que não deve haver quantidade suficiente de FAK no osso detectável pelo método utilizado. Por outro lado, observou-se que ERK-2, IRS-1 e IRS-2 são detectáveis no osso e devem responder ao estímulo mecânico. Além disso, o encontro dessas proteínas no tecido muscular abre novas perspectivas no estudo da influência das partes moles no processo de reparação do tecido ósseo.

It’s widely known that mechanical deformation of bone promotes activation of some proteins in the extracellular matrix and bone cells. These proteins are responsible for signaling intracellular reactions that determine bone mass growth. Studies indicate focal adhesion kinase (FAK) as a crucial protein to signal mechanical deformation caused by mechanical loading on bone, but evidences in vivo are required to prove this role. Objectives - Using a low-intensity ultrasound, investigate the influence of the mechanical loading on the expression of FAK in bone, and the possibility of detecting proteins involved on cellular proliferation of bone and skeletal muscle. Material and methods - Tibiae and fibulae of 12-weeks-rats were stimulated by low-intensity ultrasound during 20 minutes/once a day for periods of 7, 14 and 21 days. There were 4 groups, each one containing 7 rats. The control group was not stimulated. Fifteen hours after the last stimulation, the tibia and fibula were extracted for immunoblotting procedures with specific antibodies in order to evaluate FAK, FAK-Tyr(P)-397, extracellular signal-regulated kinase-2 (ERK-2), ERK-1/2-Tyr(P)-204, insulin receptor substrate-1 (IRS-1) and IRS-2. The skeletal muscle of the stimulated area was subjected to the same procedures. Results - Comparing the results of the different groups, both FAK and FAK-Tyr(P)-397 were not detected in bone. However, ERK-2, ERK-1/2-Tyr(P)-204, IRS-1 and IRS-2 were identified. Moreover, all the proteins studied were detected in skeletal muscle except for IRS-2. Discussion and conclusion - The results suggest there are no significant quantities of FAK in bone detectable by the methods used. In other hand, it was noted that ERK-2, ERK-1/2-Tyr(P)-204, IRS-1 and IRS-2 are detectable in bone and may be responsive to mechanical stimulation. In addition, the detection of these proteins in skeletal muscle, including FAK, opens up new perspectives on the study of the influence of this tissue on bone repair.

Insulin induces tyrosine phosphorylation of Shc in cell cultures and in insulin-sensitive tissues of the intact rat. However, the ability of insulin receptor (IR) tyrosine kinase to phosphorylate Shc has not been previously demonstrated. In the present study, we investigated insulin-induced IR tyrosine kinase activity towards Shc. Insulin receptor was immunoprecipitated from liver extracts, before and after a very low dose of insulin into the portal vein, and incubated with immunopurified Shc from liver of untreated rats. The kinase assay was performed in vitro in the presence of exogenous ATP and the phosphorylation level was quantified by immunoblotting with antiphosphotyrosine antibody. The results demonstrate that Shc interacted with insulin receptor after infusion of insulin, and, more important, there was insulin receptor kinase activity towards immunopurified Shc. The description of this pathway in animal tissue may have an important role in insulin receptor tyrosine kinase activity toward mitogenic transduction pathways.