ABSTRACT
Objective::To investigate the effect of betulic acid(BA) on steatosis LO2 cells. Method::LO2 cells were intervened with BA at different gradient concentrations (0, 10, 20, 40, 80, 160, 250 μmol·L-1) for 24 hours. methyl thiazolyl tetrazolium(MTT) staining was used to observed cell viability to determine the final concentration of BA. The cells were divided into control, model, dimethylsulfoxide (DMSO) and BA groups, as well as BA groups intervened with low, middle and high concentrations. First, model, DMSO and BA group's cells were cultured in 10% Lipid Mix 1 medium for 24 hours to establish a nonalcoholic fatty liver model. Then, DMSO group and low, medium and high-concentration groups were separately cultured with 0.1%DMSO medium and 20, 40, 80 μmol·L-1 BA medium for 24 hours. And control and model groups were cultured in drug-free medium for 24 hours. Oil red O staining and Nile red staining were used to observe the intracellular lipid droplets. Immunofluorescence was used to detect the protein expression of inducible nitric oxide synthase (iNOS). Western blot was used to detect the protein expression levels of receptor for advanced glycation end-products (RAGE), nuclear factor κB p65 (NF-κB p55) and iNOS. Result::BA within the concentration of 80 μmol·L-1 had no significant toxicity on LO2 cells. Compared with control group, the intracellular lipid droplets were significantly increased in the model group, and the expressions of oxidative stress-related proteins RAGE, NF-κB p65 and iNOS also increased significantly(P<0.05). Compared with model group, the intracellular lipid droplets in DMSO group were similar to those in model group, with no significant difference in the three protein expressions between the two groups. However, the intracellular lipid droplets deposition in the BA group was significantly decreased. And the expressions of RAGE, NF-κB p65 and iNOS proteins in high-concentration BA group were significantly decreased(P<0.05, P<0.01). Conclusion::BA can significantly improve the intracellular fat deposition in LO2 cells, which was probably related to the inhibition of the expressions of oxidative stress-related proteins RAGE, NF-κB p65 and iNOS.
ABSTRACT
The receptor for advanced glycation end products (RAGE) has been reported to have a pivotal role in the pathogenesis of Alzheimer's disease (AD). This study investigated RAGE levels in the hippocampus and cortex of a triple transgenic mouse model of AD (3xTg-AD) using western blotting and immunohistochemical double-labeling to assess cellular localization. Analysis of western blots showed that there were no differences in the hippocampal and cortical RAGE levels in 10-month-old adult 3xTg-AD mice, but significant increases in RAGE expression were found in the 22- to 24-month-old aged 3xTg-AD mice compared with those of age-matched controls. RAGE-positive immunoreactivity was observed primarily in neurons of aged 3xTg-AD mice with very little labeling in non-neuronal cells, with the notable exception of RAGE presence in astrocytes in the hippocampal area CA1. In addition, RAGE signals were co-localized with the intracellular amyloid precursor protein (APP)/amyloid beta (Abeta) but not with the extracellular APP/Abeta. In aged 3xTg-AD mice, expression of human tau was observed in the hippocampal area CA1 and co-localized with RAGE signals. The increased presence of RAGE in the 3xTg-AD animal model showing critical aspects of AD neuropathology indicates that RAGE may contribute to cellular dysfunction in the AD brain.
Subject(s)
Animals , Humans , Mice , Receptor for Advanced Glycation End Products , Alzheimer Disease/genetics , Amyloid beta-Peptides/metabolism , Astrocytes/metabolism , CA1 Region, Hippocampal/growth & development , Mice, Transgenic , Neurons/metabolism , Receptors, Immunologic/genetics , tau Proteins/geneticsABSTRACT
Objective To investigate the effect of high-mobility group box protein1 (HMGB1) on the expression of TNF-αand its mechanism in 16HBE in vitro. Methods groups with different HMGB1 (0, 100, 500, 2 000 ng/mL) concentration was set; RAGE antagonizing groups were as control, HMGB1-2000ng, anti-RAGE and anti-RAGE+HMGB1. The changes of TNF-αmRNA and secretion were determined by quantitative PCR and ELISA. RAGE protein level was measured by western blotting. Results HMGB1 intervention and TNF-α expression of 16HBE presented a positive dose-dependent relationship. Thechanges of RAGE was HMGB1positively concentration dependent. In comparison with HMGB1 2 000 ng/mL group, anti-RAGE+HMGB1showed a remarkable reduction of TNF-α secretion. Conclusion In vitro, HMGB1 increases TNF-α expression in 16HBE with a dose-dependent manner through RAGE.
ABSTRACT
La diabetes mellitus tipo 2 constituye una de las enfermedades más comúnmente diagnosticadas y a largo plazo lleva a diferentes complicaciones. Uno de los mecanismos por el cual se desarrollan estas alteraciones es la insulinorresistencia que impide que la glucosa sea utilizada por los diferentes órganos y tejidos, determinando alteraciones estructurales y funcionales a nivel celular. Dentro de este espectro la formación de los productos finales de la glucosilación avanzada ha alcanzado singular importancia, ya que han sido implicados en varios procesos degenerativos. Ello vuelve imperativa la necesidad de investigar potenciales blancos terapéuticos que permitan mejorar el pronóstico y la calidad de vida de los pacientes afectados por estas enfermedades.
Diabetes mellitus type 2 is one of the most frequently diagnosed diseases and in the long-term leads to a variety of complications. One of the mechanisms involved in these effects is insulin resistance which prevents glucose from being used by the different target organs and tissues, which in turn leads to structural and functional changes at the cellular level. In this context, the formation of advanced glycation end products has attained special importance as they have been implicated in several degenerative processes. It thus becomes necessary to look into potential therapeutic targets with the purpose of improving prognosis and quality of life of patients suffering from these diseases.
Subject(s)
Humans , /metabolism , Insulin Resistance , Glycation End Products, Advanced/metabolism , Receptors, Immunologic/metabolism , Diabetes ComplicationsABSTRACT
Objective To observe the effect of Vitamin E on advanced glycosylation end-products(AGEs) and their receptors in renal tissue of diabetic rats.Methods Rat diabetic nephropathy was induced by intraperitoneal injection of STZ.Rats were allocated to normal control group(NC group),diabetes mellitus group(DM group),and Vitamin E group(VE group).All rats were treated with corresponding drugs for 8 weeks.During and after the treatment,the general state,blood glucose level(BGL),blood urea nitrogen(BUN),serum creatinine(Scr),urinary albumin excretion rate(UAER),glycosylated hemoglobin(HbA1C),clearance rate of creatinine(Ccr) and kidney weight/body weight ratio were determined in different groups.The fluorescence microscope was used to observe advanced glycosylation end-products fluorescence intensity in iced slices.The expression of RAGE in rats' renal tissue slices was measured by immunohistochemistry.Results ① Compared with those in NC group,GLU,HbA1C,BUN,UAER,kidney weight/body weight ratio,contents of AGEs,and RAGE increased significantly(P