Advanced glycation end products in gastric cancer:A promising future

In this editorial,we delve into the article and offer valuable insights into a crucial aspect of gastric cancer aetiology.Gastric cancer is a malignancy emanating from the epithelial lining of the gastric mucosa and one of the most prevalent forms of cancer worldwide.The development of gastric cancer is associated with multiple risk factors,including Helicobacter pylori infection,advanced age,a diet rich in salt,and suboptimal eating patterns.Despite notable reductions in morbidity and mortality rates,gastric cancer remains a formidable public health concern,impacting patients’lives.Advanced glycation end products(AGEs)are complex compounds arising from nonenzymatic reactions within living organisms,the accumulation of which is implicated in cellular and tissue damage;thus,the levels are AGEs are correlated with the risk of diverse diseases.The investigation of AGEs is of paramount importance for the treatment of gastric cancer and can provide pivotal insights into disease pathogenesis and preventive and therapeutic strategies.The reduction of AGEs levels and suppression of their accumulation are promising avenues for mitigating the risk of gastric cancer.This approach underscores the need for further research aimed at identifying innovative interventions that can effectively lower the incidence and mortality rates of this malignancy.

Nε-(carboxymethyl)lysine promotes lipid uptake of macrophage via cluster of differentiation 36 and receptor for advanced glycation end products

BACKGROUND Advanced glycation end products(AGEs)are diabetic metabolic toxic products that cannot be ignored.Nε-(carboxymethyl)lysine(CML),a component of AGEs,could increase macrophage lipid uptake,promote foam cell formation,and thereby accelerate atherosclerosis.The receptor for AGEs(RAGE)and cluster of differentiation 36(CD36)were the receptors of CML.However,it is still unknown whether RAGE and CD36 play key roles in CML-promoted lipid uptake.AIM Our study aimed to explore the role of RAGE and CD36 in CML-induced macrophage lipid uptake.METHODS In this study,we examined the effect of CML on lipid uptake by Raw264.7 macrophages.After adding 10 mmol/L CML,the lipid accumulation in macrophages was confirmed by oil red O staining.Expression changes of CD36 and RAGE were detected with immunoblotting and quantitative real-time polymerase chain reaction.The interaction between CML with CD36 and RAGE was verified by immunoprecipitation.We synthesized a novel N-succinimidyl-4-18Ffluorobenzoate-CML radioactive probe.Radioactive receptor-ligand binding assays were performed to test the binding affinity between CML with CD36 and RAGE.The effects of blocking CD36 or RAGE on CML-promoting lipid uptake were also detected.RESULTS The study revealed that CML significantly promoted lipid uptake by macrophages.Immunoprecipitation and radioactive receptor-ligand binding assays indicated that CML could specifically bind to both CD36 and RAGE.CML had a higher affinity for CD36 than RAGE.ARG82,ASN71,and THR70 were the potential interacting amino acids that CD36 binds to CML Anti-CD36 and anti-RAGE could block the uptake of CML by macrophages.The lipid uptake promotion effect of CML was significantly attenuated after blocking CD36 or RAGE.CONCLUSION Our results suggest that the binding of CML with CD36 and RAGE promotes macrophage lipid uptake.

Implications of receptor for advanced glycation end products for progression from obesity to diabetes and from diabetes to cancer

Obesity and type 2 diabetes mellitus(T2DM)are chronic pathologies with a high incidence worldwide.They share some pathological mechanisms,including hyperinsulinemia,the production and release of hormones,and hyperglycemia.The above,over time,affects other systems of the human body by causing tissue hypoxia,low-grade inflammation,and oxidative stress,which lay the pathophysiological groundwork for cancer.The leading causes of death globally are T2DM and cancer.Other main alterations of this pathological triad include the accumulation of advanced glycation end products and the release of endogenous alarmins due to cell death(i.e.,damage-associated molecular patterns)such as the intracellular proteins high-mobility group box protein 1 and protein S100 that bind to the receptor for advanced glycation products(RAGE)-a multiligand receptor involved in inflammatory and metabolic and neoplastic processes.This review analyzes the latest advanced reports on the role of RAGE in the development of obesity,T2DM,and cancer,with an aim to understand the intracellular signaling mechanisms linked with cancer initiation.This review also explores inflammation,oxidative stress,hypoxia,cellular senescence,RAGE ligands,tumor microenvironment changes,and the“cancer hallmarks”of the leading tumors associated with T2DM.The assimilation of this information could aid in the development of diagnostic and therapeutic approaches to lower the morbidity and mortality associated with these diseases.

Advanced glycation end products:Key mediator and therapeutic target of cardiovascular complications in diabetes

The incidence of type 2 diabetes mellitus is growing in epidemic proportions and has become one of the most critical public health concerns.Cardiovascular complications associated with diabetes are the leading cause of morbidity and mortality.The cardiovascular diseases that accompany diabetes include angina,myocardial infarction,stroke,peripheral artery disease,and congestive heart failure.Among the various risk factors generated secondary to hyperglycemic situations,advanced glycation end products(AGEs)are one of the important targets for future diagnosis and prevention of diabetes.In the last decade,AGEs have drawn a lot of attention due to their involvement in diabetic pathophysiology.AGEs can be derived exogenously and endogenously through various pathways.These are a nonhomogeneous,chemically diverse group of compounds formed nonenzymatically by condensation between carbonyl groups of reducing sugars and free amino groups of protein,lipids,and nucleic acid.AGEs mediate their pathological effects at the cellular and extracellular levels by multiple pathways.At the cellular level,they activate signaling cascades via the receptor for AGEs and initiate a complex series of intracellular signaling resulting in reactive oxygen species generation,inflammation,cellular proliferation,and fibrosis that may possibly exacerbate the damaging effects on cardiac functions in diabetics.AGEs also cause covalent modifications and cross-linking of serum and extracellular matrix proteins;altering their structure,stability,and functions.Early diagnosis of diabetes may prevent its progression to complications and decrease its associated comorbidities.In the present review,we recapitulate the role of AGEs as a crucial mediator of hyperglycemia-mediated detrimental effects in diabetes-associated complications.Furthermore,this review presents an overview of future perspectives for new therapeutic interventions to ameliorate cardiovascular complications in diabetes.

Association of vascular endothelial growth factor-634G/C and receptor for advanced glycation end products G82S gene polymorphisms with diabetic retinopathy

AIMTo investigate the association of receptor for advanced glycation end products (RAGE) G82S and vascular endothelial growth factor (VEGF) -634 G/C gene polymorphisms with diabetic retinopathy (DR).METHODSOur cross-sectional study included 61 diabetic patients, 12 of them had proliferative diabetic retinopathy (PDR), 15 had non proliferative diabetic retinopathy (NPDR), 34 had no diabetic retinopathy (NDR) and 61 healthy controls. Participants were tested for RAGE G82S and VEGF -634 G/C polymorphisms by polymerase chain reaction-restriction fragment length polymorphism.RESULTSWe found a significant association between VEGF -634 G/C polymorphism and PDR as PDR patients had increased incidence of VEGF -634 CC genotype compared to NDR patients [odds ratio for CC vs (GC+GG)=6.5, 95% CI=1.5-27.8, P=0.021]. Also VEGF -634 CC genotype and C allele were significantly higher in the PDR than in NPDR patients, which is a novel finding in our study (P=0.024, 0.009 respectively). The mean triglycerides level was significantly higher in diabetic patients with CC genotype (P=0.01) as compared to patients with other genotypes. All cases and control subjects were of the same heterozygous RAGE 82G/S genotype.CONCLUSIONPatients carrying VEGF -634 C polymorphism have a higher risk of PDR development, so VEGF -634 G/C polymorphism could be used as a predictive marker for PDR in diabetic patients. We could not find a significant association between RAGE G82S polymorphism and DR.

Correlation between soluble receptor for advanced glycation end products levels and coronary artery disease in postmenopausal nondiabetic women

BACKGROUND The established cardiovascular risk factors cannot explain the overall risk of coronary artery disease(CAD),especially in women.Therefore,there is a growing need for the assessment of novel biomarkers to identify women at risk.The receptor for advanced glycation end products(RAGE)and its interaction with the advanced glycation end product(AGE)ligand have been associated with atherogenesis.The soluble fraction of RAGE(sRAGE)antagonizes RAGE signaling and exerts an antiatherogenic effect.AIM The study aim was to explore the association between plasma levels of sRAGE and CAD in nondiabetic postmenopausal women.METHODS This case-control study included 110 nondiabetic postmenopausal women who were enrolled in two groups.Group I included 55 angiographically proven CAD subjects with>50%stenosis in at least one of the major coronary arteries and Group II included 55 healthy control women who did not have CAD or had<50%stenosis of the coronary arteries.Stenosis was confirmed by invasive angiography.Plasma sRAGE was determined by an enzyme-linked immunosorbent assay.RESULTS We observed significantly lower plasma sRAGE concentrations in subjects with CAD vs healthy controls(P<0.05).Univariate and multivariate logistic regression analysis also revealed a significant correlation between plasma sRAGE levels and CAD(P=0.01).Multivariate odds ratios for CAD revealed that subjects with sRAGE concentrations below 225 pg/mL(lowest quartile)had a 6-fold increase in CAD prevalence independent of other risk factors.CONCLUSION Our findings indicated that low sRAGE levels were independently associated with CAD in nondiabetic postmenopausal women.Risk assessment of CAD in postmenopausal women can be improved by including sRAGE along with other risk factors.

Advanced glycation end product signaling and metabolic complications:Dietary approach

Advanced glycation end products(AGEs)are a heterogeneous collection of compounds formed during industrial processing and home cooking through a sequence of nonenzymatic glycation reactions.The modern western diet is full of heat-treated foods that contribute to AGE intake.Foods high in AGEs in the contemporary diet include processed cereal products.Due to industrialization and marketing strategies,restaurant meals are modified rather than being traditionally or conventionally cooked.Fried,grilled,baked,and boiled foods have the greatest AGE levels.Higher AGE-content foods include dry nuts,roasted walnuts,sunflower seeds,fried chicken,bacon,and beef.Animal proteins and processed plant foods contain furosine,acrylamide,heterocyclic amines,and 5-hydroxymethylfurfural.Furosine(2-furoil-methyl-lysine)is an amino acid found in cooked meat products and other processed foods.High concentrations of carboxymethyl-lysine,carboxyethyl-lysine,and methylglyoxal-O are found in heat-treated nonvegetarian foods,peanut butter,and cereal items.Increased plasma levels of AGEs,which are harmful chemicals that lead to age-related diseases and physiological aging,diabetes,and autoimmune/inflammatory rheumatic diseases such as systemic lupus erythematosus and rheumatoid arthritis.AGEs in the pathophysiology of metabolic diseases have been linked to individuals with diabetes mellitus who have peripheral nerves with high amounts of AGEs and diabetes has been linked to increased myelin glycation.Insulin resistance and hyperglycemia can impact numerous human tissues and organs,leading to long-term difficulties in a number of systems and organs,including the cardiovascular system.Plasma AGE levels are linked to all-cause mortality in individuals with diabetes who have fatal or nonfatal coronary artery disease,such as ventricular dysfunction.High levels of tissue AGEs are independently associated with cardiac systolic dysfunction in diabetic patients with heart failure compared with diabetic patients without heart failure.It is widely recognized that AGEs and oxidative stress play a key role in the cardiovascular complications of diabetes because they both influence and are impacted by oxidative stress.All chronic illnesses involve protein,lipid,or nucleic acid modifications including crosslinked and nondegradable aggregates known as AGEs.Endogenous AGE formation or dietary AGE uptake can result in additional protein modifications and stimulation of several inflammatory signaling pathways.Many of these systems,however,require additional explanation because they are not entirely obvious.This review summarizes the current evidence regarding dietary sources of AGEs and metabolism-related complications associated with AGEs.

Novel Inhibitory Effects of Glycyrrhizic Acid on the Accumulation of Advanced Glycation End Product and Its Receptor Expression

Beneficial effects of glycyrrhizic acid(GA),a bioactive extract of licorice root,in the prevention of metabolic syndrome have been consistently reported while advanced glycation end products(AGE)and receptor for advanced glycation end product(RAGE)are the leading factors in the development of diabetes mellitus.The aim of this study was to investigate the effects of GA on the AGE-RAGE axis using high-fat/high-sucrose(HF/HS)diet-induced metabolic syndrome rat models.Twenty four male Sprague–Dawley rats were randomly assigned into three groups for 4 weeks:(1)Group A,normal diet with standard rat chow;(2)Group B,HF/HS diet;(3)Group C,HF/HS diet and oral administration of 100 mg/kg GA per day.The results showed that HF/HS diet elevated the fasting blood glucose level and insulin resistance index which was prevented by GA supplementation.GA treatment significantly lowered the circulating AGE independent of its glucose-lowering effect.HF/HS diet also triggered RAGE upregulation in the abdominal muscles while GA administration downregulated RAGE expression in the abdominal muscles,aorta and subcutaneous adipose tissues.In conclusion,HF/HS diet could cause glucose intolerance,insulin resistance and upregulation of RAGE expression while GA ameliorated the metabolic dysregulation besides exhibiting inhibitory effects on the AGE-RAGE axis.

The role of advanced glycation end products and their mechanism in DN

Advanced glycation end products(AGEs), which are macromolecular material such as proteins, lipids, and nucleic acids free amino and reducing sugar on the reaction of aldehyde group under the condition of the enzyme, generate the stable compounds. AGEs formation is enhanced in diabetes and is associated with the development of diabetic complications. AGEs, as an important marker of chronic complications of diabetes mellitus, plays an important role in the development and progression of diabetic nephropathy. In the current review, we discuss mechanisms and the role of AGEs in diabetic nephropathy.

High glucose reduces Nrf2-dependent cRAGE release and enhances inflammasome-dependent IL-1βproduction in monocytes:the modulatory effects of EGCG

Soluble receptor for advanced glycation end products(sRAGE)acts as a decoy sequestering of RAGE ligands,thus preventing the activation of the ligand-RAGE axis linking human diseases.However,the molecular mechanisms underlying sRAGE remain unclear.In this study,THP-1 monocytes were cultured in normal glucose(NG,5.5 mmol/L)and high glucose(HG,15 mmol/L)to investigate the effects of diabetesrelevant glucose concentrations on sRAGE and interleukin-1β(IL-1β)secretion.The modulatory effects of epigallocatechin gallate(EGCG)in response to HG challenge were also evaluated.HG enhanced intracellular reactive oxygen species(ROS)generation and RAGE expression.The secretion of sRAGE,including esRAGE and cRAGE,was reduced under HG conditions,together with the downregulation of a disintegrin and metallopeptidase 10(ADAM10)and nuclear factor erythroid 2-related factor 2(Nrf2)nuclear translocation.Mechanistically,the HG effects were counteracted by siRAGE and exacerbated by siNrf2.Chromatin immunoprecipitation results showed that Nrf2 binding to the ADAM10 promoter and HG interfered with this binding.Our data reinforce the notion that RAGE and Nrf2 might be sRAGE-regulating factors.Under HG conditions,the treatment of EGCG reduced ROS generation and RAGE activation.EGCG-stimulated cRAGE release was likely caused by the upregulation of the Nrf2-ADAM10 pathway.EGCG inhibited HG-mediated NLRP3 inflammasome activation at least partly by stimulating sRAGE,thereby reducing IL-1βrelease.

Emerging roles of microRNAs as diagnostics and potential therapeutic interest in type 2 diabetes mellitus

BACKGROUND Type 2 diabetes mellitus(T2DM)is a metabolic disease of impaired glucose utilization.Uncontrolled high sugar levels lead to advanced glycation end products(AGEs),which affects several metabolic pathways by its receptor of advanced glycation end products(RAGE)and causes diabetic complication.MiRNAs are small RNA molecules which regulate genes linked to diabetes and affect AGEs pathogenesis,and target tissues,influencing health and disease processes.AIM To explore miRNA roles in T2DM's metabolic pathways for potential therapeutic and diagnostic advancements in diabetes complications.METHODS We systematically searched the electronic database PubMed using keywords.We included free,full-length research articles that evaluate the role of miRNAs in T2DM and its complications,focusing on genetic and molecular disease mechanisms.After assessing the full-length papers of the shortlisted articles,we included 12 research articles.RESULTS Several types of miRNAs are linked in metabolic pathways which are affected by AGE/RAGE axis in T2DM and its complications.miR-96-5p,miR-7-5p,miR-132,has_circ_0071106,miR-143,miR-21,miR-145-5p,and more are associated with various aspects of T2DM,including disease risk,diagnostic markers,complications,and gene regulation.CONCLUSION Targeting the AGE/RAGE axis,with a focus on miRNA regulation,holds promise for managing T2DM and its complications.MiRNAs have therapeutic potential as they can influence the metabolic pathways affected by AGEs and RAGE,potentially reducing inflammation,oxidative stress,and vascular complications.Additionally,miRNAs may serve as early diagnostic biomarkers for T2DM.Further research in this area may lead to innovative therapeutic strategies for diabetes and its associated complications.

Intrafollicular Soluble RAGE Benefits Embryo Development and Predicts Clinical Pregnancy in Infertile Patients of Advanced Maternal Age Undergoing In Vitro Fertilization

Soluble receptor for advanced glycation end products（s RAGE） can decoy the toxic AGEs and is considered to be a protective factor.This study aimed to evaluate the correlation between intrafollicular s RAGE levels and clinical outcomes in infertile women of young or advanced maternal age（AMA） undergoing in vitro fertilization（IVF）.A total of 62 young women and 62 AMA women who would undergo IVF were included in this prospective study.The intrafollicular s RAGE concentration was measured to determine its association with the number of retrieved oocytes,fertilized oocytes,high-quality embryos or achievement of clinical pregnancy in young and AMA women,respectively.Besides,correlations between sR AGE and age or follicle-stimulating hormone（FSH） were examined.We found that the intrafollicular s RAGE levels were higher in young patients than those in AMA patients,suggesting that the s RAGE levels were inversely correlated with age.In young patients,sR AGE showed no correlation with the number of retrieved oocytes,fertilized oocytes,high-quality embryos or achievement of clinical pregnancy.But it was found that AMA patients with more retrieved oocytes,fertilized oocytes and high-quality embryos demonstrated higher sR AGE levels,which were a prognostic factor for getting clinical pregnancy independent of age or FSH level.In conclusion,the s RAGE levels decrease with age.Elevated intrafollicular s RAGE levels indicate good follicular growth,fertilization and embryonic development,and successful clinical pregnancy in AMA women,while in young women,the role of s RAGE may not be so predominant.

Pitavastatin attenuates AGEs-induced mitophagy via inhibition of ROS generation in the mitochondria of cardiomyocytes

This study aimed to investigate whether pitavastatin protected against injury induced by advanced glycation end products products（AGEs） in neonatal rat cardiomyocytes,and to examine the underlying mechanisms.Cardiomyocytes of neonatal rats were incubated for 48 hours with AGEs（100 μg/mL）,receptor for advanced glycation end products（RAGE）,antibody（1 μg/mL） and pitavastatin（600 ng/mL）.The levels of p62 and beclinl were determined by Western blotting.Mitochondrial membrane potential（△Ψm） and the generation of reactive oxygen species（ROS） were measured through the JC-1 and DCFH-DA.In the AGEs group,the expression of beclinl was remarkably increased compared to the control group,while the expression of p62 was significantly decreased.AGEs also markedly decreased △Ψm and significantly increased ROS compared with the control group.After treatment with RAGE antibody or pitavastatin,the level of beclinl was markedly decreased compared with the AGEs group,but the level of p62 was remarkably increased.In the AGEs ＋ RAGE antibody group and AGEs＋ pitavastatin group,△Ψm was significantly increased and ROS was remarkably decreased compared with the AGEs group.In conclusion,AGEs-RAGE may induce autophagy of cardiomyocytes by generation of ROS and pitavastatin could protect against AGEs-induced injury against cardiomyocytes.

Role of the CXCR4-SDF1-HMGB1 pathway in the directional migration of cells and regeneration of affected organs

In recent years,several studies have reported positive outcomes of cell-based therapies despite insufficient engraftment of transplanted cells.These findings have created a huge interest in the regenerative potential of paracrine factors released from transplanted stem or progenitor cells.Interestingly,this notion has also led scientists to question the role of proteins in the secretome produced by cells,tissues or organisms under certain conditions or at a particular time of regenerative therapy.Further studies have revealed that the secretomes derived from different cell types contain paracrine factors that could help to prevent apoptosis and induce proliferation of cells residing within the tissues of affected organs.This could also facilitate the migration of immune,progenitor and stem cells within the body to the site of inflammation.Of these different paracrine factors present within the secretome,researchers have given proper consideration to stromal cell-derived factor-1(SDF1)that plays a vital role in tissue-specific migration of the cells needed for regeneration.Recently researchers recognized that SDF1 could facilitate site-specific migration of cells by regulating SDF1-CXCR4 and/or HMGB1-SDF1-CXCR4 pathways which is vital for tissue regeneration.Hence in this study,we have attempted to describe the role of different types of cells within the body in facilitating regeneration while emphasizing the HMGB1-SDF1-CXCR4 pathway that orchestrates the migration of cells to the site where regeneration is needed.

RAGE gene three polymorphisms with Crohn's disease susceptibility in Chinese Han population

AIM: To investigate the association of three polymorphisms in the receptor for advanced glycation end product (RAGE) gene with Crohn&#x02019;s disease (CD) risk in a Chinese population.

Aβ40 Promotes the Osteoblastic Differentiation of Aortic Valve Interstitial Cells through the RAGE Pathway

Amyloid beta(AB)peptide 40 enhances the activation of receptor for advanced glycation end products(RAGE)in immune-inflammatory diseases.RAGE exhibits several ffects in the setting of numerous cardiovascular events.We bypothesized that the Aβ40/RAGE pathway is involved in the osteoblastic differentiation of the valvular interstitial cell(VIC)phenotype,and RAGE knockout intervention could reduce the calcification of aortic valve interstitial cells(AVICs)by inhibiting the extracellular-regulated kinase1/2(ERK 1/2)/nuclear factor kappa-B(NF-kB)signaling pathway.To test this hypothesis,the activation of AB40/RAGE pathway in human calcific AVs was evaluated with immunohistochemical staining.Cultured calcific VIC models were used in vitro.The VICs were stimulated using Aβ40,with or without RAGE small interfering ribonucleic acid(siRNA),and ERK1/2 and NF-κB inhibitors for analysis.Our data revealed that AB40 induced the ERK 1/2/NF-κB signaling pathway and osteoblastic differentiation of AVICs via the RAGE pathway in vitro.

Electroacupuncture Improves Blood-Brain Barrier and Hippocampal Neuroinflammation in SAMP8 Mice by Inhibiting HMGB1/TLR4 and RAGE/NADPH Signaling Pathways

Objective: To investigate the molecular mechanisms underlying the beneficial effect of electroacupuncture(EA) in experimental models of Alzheimer’s disease(AD) in vivo. Methods: Senescenceaccelerated mouse prone 8(SAMP8) mice were used as AD models and received EA at Yingxiang(LI 20, bilateral) and Yintang(GV 29) points for 20 days. For certain experiments, SAMP8 mice were injected intravenously with human fibrin(2 mg). The Morris water maze test was used to assess cognitive and memory abilities. The changes of tight junctions of blood-brain barrier(BBB) in mice were observed by transmission electron microscope. The expressions of fibrin, amyloid-β(Aβ), and ionized calcium-binding adapter molecule 1(IBa-1) in mouse hippocampus(CA1/CA3) were detected by reverse transcription-quantitative polymerase chain reaction(qRT-PCR), Western blot or immunohistochemical staining. The expression of fibrin in mouse plasma was detected by enzyme-linked immunosorbent assay. The expressions of tight junction proteins zonula occludens-1 and claudin-5 in hippocampus were detected by qRT-PCR and immunofluorescence staining.Apoptosis of hippocampal neurons was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling(TUNEL) staining. Results: Fibrin was time-dependently deposited in the hippocampus of SAMP8mice and this was inhibited by EA treatment(P<0.05 or P<0.01). Furthermore, EA treatment suppressed the accumulation of Aβ in the hippocampus of SAMP8 mice(P<0.01), which was reversed by fibrin injection(P<0.05 or P<0.01). EA improved SAMP8 mice cognitive impairment and BBB permeability(P<0.05 or P<0.01).Moreover, EA decreased reactive oxygen species levels and neuroinflammation in the hippocampus of SAMP8mice, which was reversed by fibrin injection(P<0.05 or P<0.01). Mechanistically, EA inhibited the promoting effect of fibrin on the high mobility group box protein 1(HMGB1)/toll-like receptor 4(TLR4) and receptor for advanced glycation end products(RAGE)/nicotinamide adenine dinucleotide phosphate(NADPH) signaling pathways(P<0.01). Conclusion: EA may potentially improve cognitive impairment in AD via inhibition of fibrin/Aβdeposition and deactivation of the HMGB1/TLR4 and RAGE/NADPH signaling pathways.

Effect of electroacupuncture on conduction velocity of the sciatic nerve in experimental diabetic rats and its mechanisms

Objective To investigate the mechanisms of acupuncture in accelerating regeneration of injured sciatic nerve, the effect of electroacupuncture （EA） at ＂Huantiao （环跳 GB 30）＂ and ＂Zusanli （足三里 ST 36）＂ on conduction velocity and mRNA expression of receptors of advanced glycation end products （RAGE） of the sciatic nerve were observed in experimental diabetic rats. Methods Streptozotocin was injected into the left abdomen in 30 male rats to establish diabetes mellitus （DM） models with hyperglycemia （〉16.7 mmol/L）. Thirty rats with DM were divided into a diabetes model group （group DM）, a Methycobal group （group MET） and an EA group （group EA）. Another 8 rats comparable in body weight and age were used as a normal control group （group NC）. General situation and blood sugar levels of all the rats were recorded, and the conduction velocities of the sciatic nerves were measured. RAGE mRNA expression of the sciatic nerve was detected by means of reverse transcription polymerase chain reaction（RT-PCR）16 weeks after treatment. Results After 16 weeks, the conduction velocities of the sciatic nerves were lowered in group DM, compared with those in group NC, indicating lesion of peripheral nerves. Compared with group DM, the conduction velocities of the sciatic nerves were significantly elevated in both group EA and group MET （P〈0.01 ）, and there was a significant difference between the two groups, showing superiority of EA to Methycobal （P〈0.01）. The RAGE mRNA levels of the sciatic nerves in group DM were significantly higher than those in group NC （P〈0.01）. The RAGE mRNA levels of the sciatic nerves in both group EA and group MET were remarkably lowered than those in group DM （P〈0.01）, and the decrease in group EA was more obviously than that in group MET （P〈0.01）. Conclusion EA may exert its therapeutic effects on diabetic perineuropathy （DPN） by way of regulating abnormal expression of RAGE mRNA in the sciatic nerve and alleviating its injury caused by advanced glycation end products （AGEs） accumulation and diminishing oxidative stress to enhance its conduction velocity.

Intelligent lesion blood–brain barrier targeting nano-missiles for Alzheimer's disease treatment by anti-neuroinflammation and neuroprotection

The treatment of Alzheimer's disease(AD)is one of the most difficult challenges in neurodegenerative diseases due to the insufficient blood‒brain barrier(BBB)permeability and unsatisfactory intra-brain distribution of drugs.Therefore,we established an ibuprofen and FK506 encapsulated drug co-delivery system(Ibu&FK@RNPs),which can target the receptor of advanced glycation endproducts(RAGE)and response to the high level of reactive oxygen species(ROS)in AD.RAGE is highly and specifically expressed on the lesion neurovascular unit of AD,this property helps to improve targeting specificity of the system and reduce unselective distribution in normal brain.Meanwhile,these two drugs can be specifically released in astrocytes of AD lesion in response to high levels of ROS.As a result,the cognition of AD mice was significantly improved and the quantity of Aβplaques was decreased.Neurotoxicity was also alleviated with structural regeneration and functional recovery of neurons.Besides,the neuroinflammation dominated by NF-κB pathway was significantly inhibited with decreased NF-κB and IL-1βin the brain.Overall,Ibu&FK@RNPs can efficiently and successively target diseased BBB and astrocytes in AD lesion.Thus it significantly enhances intracephalic accumulation of drugs and efficiently treats AD by anti-neuroinflammation and neuroprotection.

HMGB1 is a critical molecule in the pathogenesis of Gram-negative sepsis

Gram-negative sepsis is a severe clinical syndrome associated with significant morbidity and mortality.Lipopolysaccharide(LPS),expressed on Gram-negative bacteria,is a potent pro-inflammatory toxin that induces inflammation and coagulation via two separate receptor systems.One is Toll-like receptor 4(TLR4),expressed on cell surfaces and in endosomes,and the other is the cytosolic receptor caspase-11(caspases-4 and-5 in hu-mans).Extracellular LPS binds to high mobility group box 1(HMGB1)protein,a cytokine-like molecule.The HMGB1-LPS complex is transported via receptor for advanced glycated end products(RAGE)-endocytosis to the endolysosomal system to reach the cytosolic LPS receptor caspase-11 to induce HMGB1 release,inflammation,and coagulation that may cause multi-organ failure.The insight that LPS needs HMGB1 assistance to generate severe inflammation has led to successful therapeutic results in preclinical Gram-negative sepsis studies target-ing HMGB1.However,to date,no clinical studies have been performed based on this strategy.HMGB1 is also actively released by peripheral sensory nerves and this mechanism is fundamental for the initiation and prop-agation of inflammation during tissue injury.Homeostasis is achieved when other neurons actively restrict the inflammatory response via monitoring by the central nervous system and the vagus nerve through the cholinergic anti-inflammatory pathway.The neuronal control in Gram-negative sepsis needs further studies since a deeper understanding of the interplay between HMGB1 and acetylcholine may have beneficial therapeutic implications.Herein,we review the synergistic overlapping mechanisms of LPS and HMGB1 and discuss future treatment opportunities in Gram-negative sepsis.