N-Acetyl Cysteine Attenuated the Deleterious Effects of Advanced Glycation End-Products on the Kidney of Non-Diabetic Rats
CELLULAR PHYSIOLOGY AND BIOCHEMISTRY
Authors: Thieme, Karina; Da Silva, Karolline S.; Fabre, Nelly T.; Catanozi, Sergio; Monteiro, Maria Beatriz; Santos-Bezerra, Daniele Pereira; Costa-Pessoa, Juliana Martins; Oliveira-Souza, Maria; Machado, Ubiratan F.; Passarelli, Marisa; Correa-Giannella, Maria Lucia
Abstract
Aim: To assess the renal effects of chronic exposure to advanced glycation end-products (AGEs) in the absence of diabetes and the potential impact of concomitant treatment with the antioxidant N-acetyl cysteine (NAC). Methods: Wistar rats received intraperitoneally 20 mg/kg/day of albumin modified (AIbAGE) or not (AIbC) by advanced glycation for 12 weeks and oral NAC (600mg/L; AIbAGE+NAC and AlbC+NAC, respectively). Biochemical, urinary and renal morphological analyses; carboxymethyl-lysine (CML, an AGE), CD68 (macrophage infiltration), and 4-hydroxynonenal (4-HNE, marker of oxidative stress) immunostaining; intrarenal mRNA expression of genes belonging to pathways related to AGEs (Ager, Ddost, Nfkb1), renin-angiotensin system (Agt, Ren, Ace), fibrosis (Tgfb1, Col4a1), oxidative stress (Nox4, Txnip), and apoptosis (Box, Bcl2); and reactive oxidative species (ROS) content were performed. Results: AIbAGE significantly increased urine protein-to-creatinine ratio; glomerular area; renal CML content and macrophage infiltration; expression of Ager, Nfkb1, Agt, Ren, Tgfb1, Col4a1, Txnip, Bax/Bcl2 ratio; and 4-HNE and ROS contents. Some of these effects were attenuated by NAC concomitant treatment. Conclusion: Because AGEs are highly consumed in modern diets and implicated in the progression of different kidney diseases, NAC could be a therapeutic intervention to decrease renal damage, considering that long-term restriction of dietary AGEs is difficult to achieve in practice. (C) 2016 The Author(s) Published by S. Karger AG, Basel
Synergistic alveolar bone resorption by diabetic advanced glycation end products and mechanical forces
JOURNAL OF PERIODONTOLOGY
Authors: Moon, Jung-Sun; Lee, Su-Young; Kim, Jung-Ha; Choi, Yoon-Ho; Yang, Dong-Wook; Kang, Jee-Hae; Ko, Hyun-Mi; Cho, Jin-Hyoung; Koh, Jeong-Tae; Kim, Won-Jae; Kim, Min-Seok; Kim, Sun-Hun
Abstract
Background The association between diabetes mellitus (DM) and bone diseases is acknowledged. However, the mechanistic pathways leading to the alveolar bone (AB) destruction remain unclear. This study aims to elucidate the mechanical forces (MF)-induced AB destruction in DM and its underlying mechanism. Methods In vivo periodontal tissue responses to MF were evaluated in rats with diabetes. In vitro human periodontal ligament (PDL) cells were either treated with advanced glycation end products (AGEs) alone or with AGEs and MF. Results In vivo, the transcription of VEGF-A, colony stimulating factor-1 (CSF-1), and Ager was upregulated in diabetes, whereas changes in DDOST and Glo1 mRNAs were negligible. DM induced VEGF-A protein in the vascular cells of the PDL and subsequent angiogenesis, but DM itself did not induce osteoclastogenesis. MF-induced AB resorption was augmented in DM, and such augmentation was morphologically substantiated by the occasional undermining resorption as well as the frontal resorption of the AB by osteoclasts. The mRNA levels of CSF-1 and vascular endothelial growth factor (VEGF) during MF application were highly elevated in diabetes, compared with those of the normal counterparts. In vitro, AGEs treatment elevated Glut-1 and CSF-1 mRNA levels via the p38 and JNK pathways, whereas OGT and VEGF levels remained unchanged. Compressive MF especially caused upregulation of VEGF, CSF-1, and Glut-1 levels, and such upregulation was further enhanced by AGEs treatment. Conclusions Overloaded MF and AGEs metabolites may synergistically aggravate AB destruction by upregulating CSF-1 and VEGF. Therefore, regulating the compressive overloading of teeth, as well as the levels of diabetic AGEs, may prove to be an effective therapeutic modality for managing DM-induced AB destruction.