Brazil Nut-Enriched Diet Modulates Enteric Glial Cells and Gut Microbiota in an Experimental Model of Chronic Kidney Disease.

Introduction: Chronic kidney disease (CKD) promotes gut dysbiosis, and enteric glial reactivity, a feature of intestinal inflammation. Brazil nut modulated enteric glial profile in healthy animals and could modulate these cells in 5/6 nephrectomized rats.Methods: A 5/6 nephrectomy-induced CKD and Sham-operated rats were divided as follows: CKD and Sham received a standard diet and CKD-BN and Sham-BN received a 5% Brazil nut enriched-diet. The protein content of glial fibrillary acid protein (GFAP), enteric glial marker, and GPx protein content and activity were assessed in the colon. The major phyla of gut microbiota were assessed.Results: CKD-BN group presented a decrease in GFAP content (p = 0.0001). The CKD-BN group modulated the abundance of Firmicutes, increasing its proportion compared to the CKD group. The CKD-BN group showed increased GPx activity in the colon (p = 0.0192), despite no significant difference in protein content.Conclusion: Brazil nut-enriched diet consumption decreased enteric glial reactivity and modulated gut microbiota in the CKD experimental model.

5/6 nephrectomy affects enteric glial cells and promotes impaired antioxidant defense in the colonic neuromuscular layer.

AIMS: Chronic kidney disease (CKD) produces multiple repercussions in the gastrointestinal tract (GIT), such as alterations in motility, gut microbiota, intestinal permeability, and increased oxidative stress. However, despite enteric glial cells (EGC) having important neural and immune features in GIT physiology, their function in CKD remains unknown. The present study investigates colonic glial markers, inflammation, and antioxidant parameters in a CKD model. MAIN METHODS: A 5/6 nephrectomized rat model was used to induce CKD in rats and Sham-operated animals as a control to suppress. Biochemical measures in plasma and neuromuscular layer such as glutathione peroxidase (GPx) and superoxide dismutase (SOD) activity were carried out. Kidney histopathology was evaluated. Colon morphology analysis and glial fibrillary acid protein (GFAP), connexin-43 (Cx43), nuclear factor-kappa B (NF-κB) p65, and GPx protein expression were performed. KEY FINDINGS: The CKD group exhibited dilated tubules and tubulointerstitial fibrosis in the reminiscent kidney (p = 0.0002). CKD rats showed higher SOD activity (p = 0.004) in plasma, with no differences in neuromuscular layer (p = 0.9833). However, GPx activity was decreased in the CKD group in plasma (p = 0.013) and neuromuscular layer (p = 0.0338). Morphological analysis revealed alterations in colonic morphometry with inflammatory foci in the submucosal layer and neuromuscular layer straightness in CKD rats (p = 0.0291). In addition, GFAP, Cx43, NF-κBp65 protein expression were increased, and GPx decreased in the neuromuscular layer of the CKD group (p < 0.05). SIGNIFICANCE: CKD animals present alterations in colonic cytoarchitecture and decreased layer thickness. Moreover, CKD affects the enteric glial network of the neuromuscular layer, associated with decreased antioxidant activity and inflammation.

Bovine tunica albuginea conserved in honey as xenograft for cystoplasty in rats / Túnica albugínea bovina conservada em mel como xenoenxerto na cistoplastia em ratos

ABSTRACT: Urinary bladder damages leading to few viable bladder tissue available might demand a challenging reconstructive surgery. In this context, biomaterials are valid alternatives for bladder reconstruction. This study evaluated the bovine tunica albuginea fragment as graft material for cystoplasty in rats and honey-preserved implant viability.Thirty Wistar rats were assigned to two groups: (1) a test group (T) with a circular 1.0-cm-diameterbovine tunica albuginea graft application in the apex region by a continuous absorbable (Polyglactin 910 5-0) suture with stitching of all bladder layers and (2) a simulation group (S) in which animals underwent only partial cystectomy. In addition, each of these groups was further divided into three subgroups according to euthanasia period on post-surgery day 7, 15 and 30.Two animals had self-limiting hematuria at postsurgical period. At necropsy, frequent crystals and adhesion to the peritoneum were observed. At the histopathological evaluation, animals from the T group euthanized by 15th postoperative day had layers disorganization and initial muscle development, while T group rats euthanized by 30th postoperative day showed complete urothelization. Urothelization pattern was similar in both groups. Moreover, the muscular layer formation was present in both groups, but more evident in S group animals. Nevertheless, inflammatory infiltrate and neovascularization were remarkably more intense in T group rats.It might be concluded that bovine tunica albuginea graft was successful in repairing rats' bladder, being a good biomaterial option in reconstructive urinary vesicle surgery.

RESUMO: Lesões na vesícula urinária que culminem em pouco tecido vesical viável podem demandar cirurgias reconstrutivas desafiadoras. Neste contexto, biomateriais são alternativas válidas para a reconstrução da bexiga. O objetivo deste trabalho foi avaliar a túnica albugínea bovina como material para enxerto na cistoplastia em ratos, assim como a viabilidade deste implante preservado em mel. Trinta ratos Wistar foram divididos em dois grupos: (1) um grupo teste (T), no qual os animais foram submetidos a cistectomia parcial seguida de cistoplastia com aplicação do enxerto circular com 1,0cm de diâmetro de túnica albugínea bovina na região do ápice com sutura absorvível (Poliglactina 910 5-0) em padrão contínuo englobando todas as camadas da bexiga; e (2) um grupo simulação (S), cujos ratos realizaram apenas cistectomia parcial. Além disso, cada grupo foi posteriormente dividido em três subgrupos de acordo com a data de eutanásia no dia 7, 15 ou 30 de pós-operatório.Dois animais apresentaram hematúria autolimitante no período de observação pós-operatória. Na necrópsia, notaram-se cristais frequentes e aderências entre bexiga e peritônio. Na avaliação histopatológica, animais do grupo T eutanasiados com 15 dias de pós-operatório apresentavam camadas vesicais desorganizadas e formação de musculatura inicial na bexiga, enquanto aqueles eutanasiados com 30 dias de cirurgia mostraram urotelização completa. O padrão de urotelização foi semelhante nos dois grupos. Além disso, a formação da camada muscular esteve presente em ambos os grupos, porém mais evidente nos animais do grupo S. No entanto, o infiltrado inflamatório bem como a neovascularização foram notavelmente mais intensos nos ratos do grupo T.Pode-se concluir que o enxerto de túnica albugínea bovina foi bem sucedido no reparo da vesícula urinária de ratos, demonstrando ser uma boa opção de biomaterial para cirurgias reconstrutivas da vesícula urinária.