Advanced glycation end products consumption and the decline of functional capacity in patients with Parkinson's disease: Cross-sectional study

Abstract Introduction Advanced Glycation End-Products (AGEs) are a diverse group of highly reactive molecules that play a vital role in the development of neurodegenerative disorders, such as Parkinson's Disease (PD), leading to a decline in functional and cognitive capacity. The objective of this study was to assess the intake and quantification of AGEs in individuals with PD and to correlate them with their functional and cognitive abilities. Methods This was a cross-sectional study involving 20 PD patients and 20 non-PD individuals as the Control group (C). The autofluorescence reader was used to evaluate skin AGEs, while food recall was used to quantify AGEs consumed for three different days. The Montreal Cognitive Assessment, Short Physical Performance Battery, and handgrip tests were used. PD patients demonstrated greater impairment in functional capacity compared to the control group. Results Dominant Handgrip (p = 0.02) and motor performance, in the sit and stand test (p = 0.01) and Short Physical Performance Battery (SPPB) (p = 0.01) were inferior in PD patients than the control group. Although PD patients tended to consume less AGEs than the control group, AGE intake was negatively correlated with handgrip strength in individuals with PD (r = -0.59; p < 0.05). Conclusion PD patients had lower strength and functional capacity, suggesting that the effects of AGEs might be exacerbated during chronic diseases like Parkinson's.

Oxidative stress and antioxidant markers in patients with alopecia areata: A comparative cross-sectional study

Background: Alopecia areata is a chronic inflammatory skin disease. Oxidative stress may contribute to the pathogenesis of this condition. Aim: To evaluate the serum oxidative stress markers and antioxidant capacity in patients with alopecia areata. Methods: This cross-sectional study was performed on 40 patients with alopecia areata and 40 healthy controls. The fasting blood sugar, C-reactive protein, lipid profile, and serum oxidative markers, including advanced glycation end products and advanced oxidation protein products, were measured in this study. Also, antioxidant enzymes, including paraoxonase-1, lecithin-cholesterol acyltransferase and serum ferric-reducing antioxidant power, were determined. Results: The serum levels of advanced glycation end products and advanced oxidation protein products were significantly higher in patients with alopecia areata, compared to the controls (P < 0.001), whereas the levels of ferric-reducing antioxidant power, paraoxonase-1 and lecithin-cholesterol acyltransferase were significantly lower in patients with alopecia areata, compared to the controls (P < 0.001). The mean fasting blood sugar level was significantly higher in patients with alopecia areata, compared to the controls. The ferric reducing antioxidant power level was significantly associated with the percentage of hair loss (P = 0.01, r = 0.4) and the serum C-reactive protein level (P = 0.03, r = –0.3) in patients with alopecia areata. Limitations: Since the current study had a cross-sectional design, no cause-effect relationship was established between alopecia areata and oxidative stress. The sample size of our study was also small. Conclusion: Based on the present results, the oxidant-antioxidant enzymatic system is impaired in alopecia areata due to the increased oxidative products and decreased antioxidant activity

Dahuang Mudantang Alleviates Intestinal Injury in Rat Model of Acute Pancreatitis by Regulating HMGB1/RAGE/NF-κB Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo explore the mechanism of Dahuang Mudantang in alleviating the intestinal injury in the rat model of acute pancreatitis via the high-mobility group box 1 （HMGB1）/receptor for advanced glycation endproduct （RAGE）/nuclear factor-κB （NF-κB） signaling pathway. MethodOne hundred and twenty SPF-grade Wistar rats received retrograde injection of 5% sodium taurocholate into the biliopancreatic duct for the modeling of intestinal injury in acute pancreatitis. The rats were randomized into blank， model， low-， medium-， and high-dose （3.5， 7， 14 g·kg-1， administrated by gavage） Dahuang Mudantang， and octreotide （1×10-5 g·kg-1， subcutaneous injection） groups （n=20）. The rats in blank and model groups received equal volume of distilled water by gavage. Drugs were administered 1 h before and every 12 h after modeling， and samples were collected 24 h after modeling. The general status of the rats was observed. The biochemical methods were employed to measure the levels of amylase （AMS） and C-reactive protein （CRP） in the serum. The enzyme-linked immunosorbent assay （ELISA） was employed to measure the levels of tumor necrosis factor （TNF）-α， interleukin （IL）-1β， and IL-6 in the colon tissue. The morphological changes of pancreatic and colon tissues were observed by hematoxylin-eosin （HE） staining. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） and Western blot were employed to measure the expression levels of HMGB1， RAGE， inhibitor of NF-κB kinase （IKK）， and NF-κB suppressor protein α（IκBα）in the colon tissue. ResultThe rats in the model group showed poor general survival， writhing response， reduced frequency of defecation， and dry stool. The symptoms of rats in the model group were mitigated in each treatment group， and the high-dose Dahuang Mudantang showed the most significant effect. Compared with the normal group， the model group had elevated AMS and CRP levels （P<0.05）， which were lowered by Dahuang Mudantang （P<0.05）， especially that at the high dose （P<0.05）. Compared with the normal group， the modeling elevated that levels of TNF-α， IL-1β， and IL-6 （P<0.05）. Such elevations were lowered by Dahuang Mudantang （P<0.05）， and the high-dose group and the octreotide group showed better performance （P<0.05）. The modeling caused necrotic， congested， and destructed pancreatic and colonic tissues， which were ameliorated by the drugs， especially high-dose Dahuang Mudantang. Compared with the normal group， the modeling up-regulated the mRNA levels of HMGB1， RAGE， IKK， IκBα， and NF-κB （P<0.05）. Compared with the model group， Dahuang Mudantang and octreotide down-regulated the mRNA levels of HMGB1， RAGE， IKK， IκBα， and NF-κB （P<0.05）， and the high-dose Dahuang Mudantang demonstrated the best performance （P<0.05）. Western blot results showed a trend consistent with the results of Real-time PCR. ConclusionDahuang Mudantang can improved the general status， reduce inflammation， and alleviate histopathological changes in the pancreatic and colon tissues in the rat model of acute pancreatitis by inhibiting the HMGB1/RAGE/NF-κB signaling pathway.

The mechanism of the receptors for advanced glycation end products affecting pericyte detachment from blood vessels after traumatic brain injury / 西安交通大学学报(医学版)

【Objective】 To observe the reactive change of cortical perivascular cells after craniocerebral injury and explore its mechanism. 【Methods】 The controllable cortical impact animal model was used to simulate craniocerebral injury, the expressions of cortical pericyte markers at different time points after trauma were studied by Western blotting, and the biological behavior of vascular pericytes after craniocerebral injury was determined by transmission electron microscopy. Post-traumatic high mobility group box 1 (HMGB1), receptor for advanced glycation end product (RAGE), and nuclear factor κB (NF-κB) were detected by Western blotting. The experimental animals were divided into FPS-ZM1 (a specific RAGE receptor blocker) injection group and wild-type group. Wet and dry brain weight and transmission electron microscopy were used to study the post-traumatic effects of HMGB1-RAGE on pericytes. The primary mouse brain microvascular pericytes were cultured and supplemented with HMGB1 recombinant protein; the cultured pericytes supplemented with FPS-ZM1 were used as the control to explore the effect of HMGB1-RAGE pathway on vascular pericytes in vitro. 【Results】 The expression levels of early post-traumatic cortical pericyte markers platelet-derived growth factor receptor beta (PDGFR-β) and NG2 proteoglycan (NG2) decreased (PDGFR-β, Control vs. CCI 3D P<0.05; NG2, Control vs. CCI 6H P<0.05; Control vs. CCI 1D P<0.05). We found that pericytes were detached from blood vessels, accompanied by local blood-brain barrier opening. The expression of HMGB1-RAGE-NF-κB signaling pathway was increased in the early cortex after trauma (HMGB1, Control vs. CCI 6H P<0.05, Control vs. CCI 1D P<0.05; RAGE, Control vs. CCI 6H P<0.05, Control vs. CCI 1D P<0.05, Control vs. CCI 3D P<0.05, Control vs. CCI 5D P<0.05, Control vs. CCI 7D P<0.05; NF-κB, Control vs. CCI 6H P<0.05, Control vs. CCI 1D P<0.05). After blocking the binding of RAGE with the ligand, cortical edema was reduced (CCI 6H P<0.05, CCI 1D P<0.05), and neurovascular unit damage was reduced. HMGB1 recombinant protein could increase the migration ability of cultured pericytes (Control vs. HMGB1 P<0.05, Control vs. HMGB1+FPS-ZM1 P<0.05), and could be reversed by FPS-ZM1 (HMGB1 vs. HMGB1+FPS-ZM1 P<0.05). 【Conclusion】 High-level HMGB1 after traumatic brain injury mediates pericytes’ detachment from blood vessels through RAGE on pericytes and leads to the occurrence of local cerebral edema.

Effect of Jingui Shenqiwan on Diabetic Osteoporosis in Mice via AGEs/RANKL/NF-κB Pathway Based on Theory of "Kidneys Governing Bones" / 中国实验方剂学杂志

ObjectiveTo investigate the effect of Jingui Shenqiwan on diabetic osteoporosis （DOP） in mice by regulating the advanced glycation end products （AGEs）/receptor activator of nuclear factor-κB ligand （RANKL）/nuclear factor-κB （NF-κB） signaling pathway based on the theory of "kidneys governing bones". MethodForty 6-week-old male and female skeletal-muscle-specific， dominant negative insulin-like growth factor-1 receptor （MKR） mice were selected and fed on a high-fat diet for eight weeks to establish the DOP model. The model mice were randomly divided into a model group， low- and high-dose Jingui Shenqiwan group （1.3， 2.6 g·kg-1）， and an alendronate sodium group （0.01 g·kg-1）， with 10 mice in each group. Additionally， 10 FVB/N mice of the same age were assigned to the normal group. The corresponding drugs were administered orally to each group once a day for four weeks. After the administration period， fasting blood glucose （FBG） measurement and oral glucose tolerance test （OGTT） were conducted. Kidney function and kidney index were measured. Renal tissue pathological changes were observed through hematoxylin-eosin （HE） and Masson staining. Immunohistochemistry was performed to assess the protein expression levels of AGEs， phosphorylated NF-κB （p-NF-κB）， and RANKL in renal tissues. Western blot analysis was conducted to measure the expression of proteins related to the AGEs/RANKL/NF-κB signaling pathway， osteoprotegerin （OPG）， and Runt-related transcription factor 2 （RUNX2） proteins in femoral bone tissues. ResultCompared with the normal group， mice in the model group exhibited significantly increased FBG （P<0.01）， trabecular bone degeneration， abnormal bone morphological parameters， significantly increased area under the curve （AUC） of OGTT （P<0.01）， enlarged kidney volume， significantly increased kidney function indicators and kidney index （P<0.01）， disrupted renal glomeruli and renal tubule structures， significantly increased expression of AGEs， RANKL， and p-NF-κB/NF-κB in renal tissues （P<0.05）， and significantly decreased expression of OPG and RUNX2 in femoral bone tissues （P<0.01）. Compared with the model group， mice in the Jingui Shenqiwan groups showed a significant decrease in OGTT AUC （P<0.01）. Histopathological analysis revealed alleviated structural lesions in renal glomeruli and renal tubules. Furthermore， the expression of AGEs， RANKL， and p-NF-κB/NF-κB in renal tissues was significantly reduced （P<0.05， P<0.01）， and the expression of RUNX2 and OPG in femoral bone tissues was significantly increased （P<0.05， P<0.01）. ConclusionJingui Shenqiwan can improve kidney function and downregulate the AGEs/RANKL/NF-κB signaling pathway to inhibit inflammatory reactions， thereby alleviating the symptoms of DOP in mice， demonstrating a therapeutic effect on DOP from the perspective of the kidney.

Mechanism of Yitangkang in Improving Apoptosis of Skeletal Muscle Cells by Inhibiting AGE/RAGE Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo determine the mechanism of Yitangkang in correcting excessive apoptosis of skeletal muscle cells to improve insulin resistance （IR） by inhibiting the advanced glycation end product （AGE）/receptor for the advanced glycation end product （RAGE） signaling pathway. Method① In vitro experiments. Yitangkang-medicated serum was prepared. C2C12 cells were divided into a blank group， a model group， high-， medium-， and low-dose Yitangkang-medicated serum groups （40， 20， and 10 g·kg-1）， and a RAGE inhibitor group. The IR model was induced by palmitic acid in C2C12 cells except for those in the blank group. After the corresponding intervention methods were conducted，the cell viability and glucose consumption level of each group were determined. In addition，the apoptosis rate was determined using flow cytometry. The mRNA and protein expression levels of the important apoptotic proteins ［B-cell lymphoma 2 （Bcl-2）， Bcl-2-associated X protein （Bax）， p53， cysteinyl aspartate-specific protease-3 （Caspase-3）， and cysteinyl aspartate-specific protease-9 （Caspase-9）］ were determined using Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） and Western blot. ② In vivo experiments. Ninety-six eligible Wistar rats were divided into a blank group， a model group， high-，medium-，and low-dose Yitangkang groups （40， 20， and 10 g·kg-1）， and a western medicine group （pioglitazone hydrochloride，1.35 mg·kg-1）. The IR model was induced using high-glucose and high-fat feed for diabetes combined with intraperitoneal injection of low-dose streptozotocin （STZ） in animals and verified by the hyperinsulinemic-euglycemic clamp （HEC） test. After the model was determined successfully， the rats in each group were given intragastric administration of drugs as required. Terminal deoxynucleotidyl transferase dUTP nick end labeling （TUNEL） assay was performed to determine the number of positive apoptotic cells in the skeletal muscle tissues of rats in each group，while Real-time polymerase chain reaction（Real-time PCR） and Western blot were performed to determine the mRNA and protein expression levels of the important apoptotic proteins Bcl-2， Bax， p53， Caspase-3， and Caspase-9. Result① In vitro experiments. compared with the blank group， the model groups showed increased apoptosis rate of C2C12 cells and decreased cell viability and glucose consumption （P<0.01）. Compared with the model group， the Yitangkang-medicated serum groups and the RAGE inhibitor group showed decreased apoptosis rate of C2C12 cells and increased cell viability and glucose consumption （P<0.01）. Compared with the blank group， the model group showed decreased expression levels of Bcl-2 mRNA and protein in C2C12 cells and increased mRNA and protein expression levels of Bax， p53， Caspase-3， and Caspase-9 （P<0.01）. Compared with the model group， the Yitangkang-medicated serum groups and the RAGE inhibitor group showed increased expression levels of Bcl-2 mRNA and protein in C2C12 cells （P<0.01） and decreased mRNA and protein expression levels of Bax， p53， Caspase-3， and Caspase-9 （P<0.05， P<0.01）. ② In vivo experiments. The number of positive apoptotic cells in the skeletal muscle tissues of rats in the model group significantly increased as compared with that in the blank group （P<0.01）. The number of positive apoptotic cells in the skeletal muscle tissues of rats in the Yitangkang groups and the western medicine group decreased as compared with that in the model group （P<0.01）. Compared with the blank group， the model group showed decreased expression levels of Bcl-2 mRNA and protein in skeletal muscle tissues of rats and increased mRNA and protein expression levels of Bax， p53， Caspase-3， and Caspase-9 （P<0.01）. Compared with the model group， the Yitangkang groups and the western medicine group showed increased expression levels of Bcl-2 mRNA and protein in skeletal muscle tissues of rats （P<0.01） and decreased mRNA and protein expression levels of Bax， p53， Caspase-3， and Caspase-9 （P<0.05， P<0.01）. The medium-dose Yitangkang showed a similar effect as RAGE inhibitor， and the effect was equivalent to that of pioglitazone hydrochloride. ConclusionYitangkang can inhibit skeletal muscle cell apoptosis by inhibiting the AGE/RAGE signaling pathway.

Changes of RAGE/p38MAPK/NF-κB signaling pathway in brain tissue of subchronic fluorosis rats and protective effects of Ginkgo biloba extract and RAGE antagonist / 环境与职业医学

Background Fluorine accumulates in the brain tissue after long-term excessive intake and subsequently cause nerve damage and decline of learning and memory ability. Receptor of advanced glycation end-products (RAGE)/p38 mitogen-activated protein kinase (p38MAPK)/nuclear factor kappa-B (NF-κB) signaling pathway is considered to be involved in the associated mechanism. Objective To study the changes of RAGE/ p38MAPK/ NF-κB signaling pathway in rats with subchronic fluorosis, and to explore the protective effects of extract of Ginkgo biloba 761 (EGb761) and RAGE antagonist (FPS-ZM1) on neuromemory ability. Methods Ninety male clean SD rats were divided into 9 groups with 10 rats in each group. The modeling period was 6 months. Control group (C group): free drinking tap water (fluoride content <0.5 mg·L−1), low- and high-dose fluoride groups (LF group, HF group): free drinking tap water with 10 or 50 mg·L−1 fluoride; intervention group of Ginkgo biloba extract (CE, LFE, and HFE groups): on the basis of the C group, LF group, and HF group, 100 mg·kg−1·d−1 EGb761 was given daily via intragastric administration; FPS-ZM1 intervention groups (CF, LFF, and HFF groups): 7 d before the end of modeling, 1 mg·kg−1·d−1 FPS-ZM1 was injected intraperitoneally daily on the basis of the C group, LF group, and HF group. The contents of fluoride in brain and blood of each group were detected. The learning and memory ability was tested by water maze experiment. The histopathologic changes of the hippocampus were detected by Nissl staining. The protein expression levels of RAGE and its ligand high mobility group protein B1 (HMGB1), NF-κB, p38MAPK, phospho-p38MAPK (p-p38MAPK), interleukin-6 (IL-6), and tumour necrosis factor-α (TNF-α) in brain tissue were detected by Western blotting. The mRNA expression levels of RAGE, HMGB1, and p38MAPK were detected by quantitative real-time PCR. Results Compared with the C group, the contents of blood fluoride and brain fluoride in the LF and the HF groups were increased (P<0.05). The results of the water maze experiment showed that, compared with the C group, the escape latency time of the LF group and the HF group was longer and the crossing times were reduced; compared with the HF group, the escape latency time of the HFE group and the HFF group was shortened, and the crossing times were increased (P<0.05). The Nissl staining results showed that the number of Nissl body in the HF group decreased compared with the C group; compared with the HF group, the number of Nissl body in the HFE group and the HFF group increased. The Western blotting results showed that compared with the relative protein expression levels of RAGE, HMGB1, NF-κB, p38MAPK, p-p38MAPK, IL-6, and TNF-α in the C group , the levels of above indicators in the HF group and the levels of RAGE, HMGB1, NF-κB, p-p38MAPK, and IL-6 in the LF group were up-regulated (P<0.05); compared with the HF group, the levels of above indicators in the HFE group and the HFF group were all down-regulated (P<0.05); compared with the relative protein expression levels of RAGE and HMGB1 in the LF group, the levels in the LFE group and the LFF group were all down-regulated (P<0.05). The quantitative real-time PCR results showed that compared with the C group, the mRNA expression levels of RAGE and HMGB1 in the LF group and the HF group were up-regulated; compared with the LF group, the mRNA expression levels of RAGE in the LFE group and the LFF group were down-regulated ; compared with the HF group, the mRNA expression levels of RAGE and HMGB1 in the HFE group and the HFF group were down-regulated (P<0.05). Conclusion The central nervous system injury caused by subchronic fluorosis may be related to the activation of RAGE/p38-MAPK/NF-κB signaling pathway, which can impair the learning and memory ability of rats, while EGb761 and FPS-ZM1 may have certain protective effects on the nerve injury.

Effect of Modified Erchentang on Bronchioles of Rats with Chronic Obstructive Pulmonary Disease by HMGB1/RAGE/NF-κB Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo study the effect of modified Erchentang on the expression of key molecules in the high mobility group Box 1 protein （HMGB1）/receptor for advanced glycation endproduct （RAGE）/nuclear factor-κB （NF-κB） signaling pathway in bronchioles of rats with chronic obstructive pulmonary disease （COPD）， to explore the mechanism of modified Erchentang against bronchiolar inflammation of COPD rats via HMGB1/RAGE/NF-κB signaling pathway. MethodSixty SD rats were randomly divided into normal group， model group， modified Erchentang low-， medium- and high-dose groups （5， 10， 20 g·kg-1·d-1） and ethyl pyruvate （HMGB1 inhibitor） group， with 10 in each group. The COPD rat model was prepared by cigarette smoke combined with tracheal injection of lipopolysaccharide （LPS）. After modeling， the modified Erchentang groups were given corresponding drugs （ig） and Ringer's solution （4 mL， ip）， while the EP group was treated with equal volume of normal saline （ig） and EP （0.04 g·kg-1·d-1， ip）. The normal group and the model group received equal volume of normal saline （ig） and Ringer's solution （ip） for 21 consecutive days. The contents of HMGB1， chemokine （C-X-C motif） ligand 1 （CXCL1）， CXCL2 and monocyte chemotactic protein-1 （MCP-1） in bronchoalveolar lavage fluid （BALF） were detected by enzyme-linked immunosorbent assay （ELISA）. The mRNA expressions of HMGB1， RAGE and NF-κB p65 were determined by Real-time polymerase chain reaction （Real-time PCR）， and the protein expressions of HMGB1， RAGE， p-NF-κB p65， and alpha-smooth muscle actin （α-SMA） in bronchioles tissue of rats were determined by immunohistochemistry （IHC）. ResultCompared with the conditions in the normal group， the forced vital capacity （FVC）， forced expiratory volume in the first second （FEV1） and FEV1/FVC in the model group were decreased （P<0.01） while the contents of HMGB1， CXCL1， CXCL2 and MCP-1 in BALF were increased （P<0.01）. And the model group presented higher mRNA expressions of HMGB1， RAGE and NF-κB p65 （P<0.01） and protein expressions of HMGB1， RAGE， p-NF-κB p65 and α-SMA （P<0.05， P<0.01） than the normal group. Compared with the model group， the modified Erchentang medium- and high-dose groups had increased FEV1/FVC （P<0.05， P<0.01）， lowered contents of HMGB1， CXCL1， CXCL2 and MCP-1 in BALF （P<0.05， P<0.05）， and reduced mRNA expressions of HMGB1， RAGE and NF-κB p65 （P<0.05， P<0.01） and protein expressions of HMGB1， RAGE， p-NF-κB p65 and α-SMA （P<0.05， P<0.01）. ConclusionModified Erchentang can resist bronchiolar inflammation of COPD rats. The mechanism may be related to down-regulating the mRNA expressiona of HMGB1 and RAGE， inhibiting the activity of NF-κB， and reducing the release of HMGB1， CXCL1， CXCL2 and MCP-1， thus suppressing the inflammatory injury and abnormal repair of bronchioles.

Improvement effects and its mechanism of catalpol on testicular lesions in KK-Ay spontaneous diabetic mice by regulating glycolysis / 中国药房

OBJECTIVE To study the improvement effects and its mechanism of catalpol on testicular lesions in KK-Ay spontaneous diabetic mice on the basis of glycolysis process mediated by advanced glycation end products （AGEs） and their receptors （RAGE）. METHODS KK-Ay spontaneous diabetic mice fed with high-fat diet were used as diabetic model， and then randomly divided into model group， catalpol group （100 mg/kg）， aminoguanidine group （AGEs inhibitor， 100 mg/kg） and FPS- ZM1 group （RAGE inhibitor， 1 mg/kg）， and C57BL/6J mice fed in the same period were set as normal group， with 6 mice in each group. The catalpol group and aminoguanidine group mice were given relevant medicine intragastrically， normal group and model group mice were given constant volume of normal saline intragastrically， and FPS-ZM1 group mice were given relevant medicine 1 mL/g intraperitoneally， for consecutive 8 weeks. After the last administration， the body mass， fasting blood glucose， 24-hour food intake， water consumption， urine volume， testicular organ coefficient， and sperm motility of the mice were measured； pathological morphology and ultrastructural structure of testicular tissue were observed； the levels of reduced glutathione （GSH）， superoxide dismutase （SOD）， lactate dehydrogenase （LDH） and sugar metabolites in testicular tissue of mice were detected； pathway enrichment analysis was performed； the level of AGEs in serum and testicular tissue， protein expressions of RAGE， B-cell lymphoma-2 （Bcl-2） and Bcl-2-associated X protein （Bax）， and mRNA expressions of key rate-limiting enzymes [hexokinase （HK）， phosphofructose kinase （PFK）， pyruvate kinase （PK）， LDH] in testicular tissue were alldetected. RESULT S Catalpol could significantly improve the general symptoms， testicular organ coefficients and motility ofsperm in KK-Ay spontaneous diabetic mice （P＜0.05 or P＜0.01）. The morphology and ultrastructure of spermatogenic cells in each layer of the seminiferous tubules were all improved. The levels of GSH， SOD and LDH in testicular tissue，the levels of the metabolic product glucose fructose-1，6-diphosphate， 3-phosphate glycerate， 3-phosphate glyceraldehyde， lactic acid and pyruvate， the expressions of HK， PFK， PK and LDH mRNA were all significantly increased（P＜0.05 or P＜0.01）； the levels of AGEs in serum and testicular tissue， the expression of RAGE protein and the ratio of Bax to Bcl-2 in testicular tissue were significantly decreased（P＜0.05 or P＜0.01）. Aminoguanidine and FPS-ZM1 could significantly improve the levels of most of above indicators in mice（P＜0.05 or P＜0.01）. CONCLUSIONS Catalpol shows significant improvement effects on testicular lesions of KK-Ay spontaneous diabetic mice， and its mechanism of action was associated with upregulation of AGEs/RAGE signaling pathway- mediated glycolysis.

Electroacupuncture Improves Blood-Brain Barrier and Hippocampal Neuroinflammation in SAMP8 Mice by Inhibiting HMGB1/TLR4 and RAGE/NADPH Signaling Pathways / 中国结合医学杂志

OBJECTIVE@#To investigate the molecular mechanisms underlying the beneficial effect of electroacupuncture (EA) in experimental models of Alzheimer's disease (AD) in vivo.@*METHODS@#Senescence-accelerated 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 SAMP8 mice 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 SAMP8 mice, 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/A β deposition and deactivation of the HMGB1/TLR4 and RAGE/NADPH signaling pathways.

Existence of advanced glycation / lipoxidation end-products in parenteral nutrition solutions and effects of infusion conditions on their levels

Abstract Infusion solutions must be stable from the production stage until the infusion stage. Some infusion fluids contain degradation products, known as advanced glycation end products (AGEs); however, it is unknown whether AGEs exist in parenteral nutrition solutions. We aimed to investigate this question and test the effect of infusion conditions on AGE formation in parenteral nutrition solution. Nine parenteral nutrition solutions were supplied by the pharmacy with which we collaborated. To simulate the infusion conditions, the solutions were held in a patient room with standard lighting and temperature for 24 hours. Samples were taken at the beginning (group A) and the end (24th hour, group B) of the infusion period. The degradation products were 3-deoxyglucosone, pentosidine, N-carboxymethyl lysine, and 4-hydroxynonenal, which we investigated by high-performance liquid chromatography-mass spectrometry (LC-MS) and Q-TOF LC/MS methods. Two of four degradation products, 4-hydroxynonenal and N-carboxymethyl lysine, were detected in all samples, and Group B had higher levels of both compounds compared to Group A, who showed that the quantities of these compounds increased in room conditions over time. The increase was significant for 4-hydroxynonenal (p=0.03), but not for N-carboxymethyl lysine (p=0.23). Moreover, we detected in the parenteral nutrition solutions a compound that could have been 4-hydroxy-2-butynal or furanone

Relationship of advanced glycation end-products in hypertension in diabetic patients: a systematic review / Relação dos produtos finais de glicação avançada na hipertensão de pacientes com diabetes: uma revisão sistemática

Abstract Diabetes mellitus and arterial hypertension are among the five risk factors that increase mortality in the world. Both are chronic, non-communicable diseases (NCDs), that have a pathophysiological association. Advanced glycation end products (AGEs), produced by the lack of glycemic control in diabetic patients, interact with their AGE receptors (AGER) resulting in increased arterial stiffness, inflammation and endothelial changes - which increases the risk of developing hypertension and other complications. We ran a systematic review in Pubmed, SciELO, Cochrane Library and Web of Science databases using keywords and Boolean operators to optimize the search, with the objective of assessing the mechanism of non-enzymatic glycation of proteins present in patients with diabetes and its correlation with the onset of hypertension, exposing all the endothelial and cellular damage caused by AGEs. We found 719 papers, of which 99 were read in full, and 26 met the eligibility criteria and were included in the present review. AGEs should be considered one of the main cardiometabolic risk factors. Reducing the AGE-AGER interaction will result in cardiovascular protection and increased life expectancy.

Resumo Diabetes mellitus e hipertensão arterial estão entre os cinco fatores de risco que elevam a mortalidade no mundo. Ambas são doenças crônicas não transmissíveis (DCNT) que têm associação fisiopatológica. Os produtos finais de glicação avançada (AGEs), produzidos pela falta de controle glicêmico nos pacientes diabéticos, interagem com seus receptores para AGEs (RAGE) resultando no aumento da rigidez arterial e da inflamação e em alterações endoteliais, fatores que intensificam o risco do desenvolvimento da hipertensão e de demais complicações. Realizou-se uma revisão sistemática nas bases de dados Pubmed, SciELO, Cochrane Library e Web of Science utilizando descritores e operadores booleanos para otimizar a busca, com o objetivo de fornecer o mecanismo da glicação não enzimática de proteínas presente em pacientes com diabetes e sua correlação com o aparecimento da hipertensão, expondo todo o dano endotelial e celular ocasionado pelos AGEs. Foram encontrados 719 artigos, dos quais 99 foram lidos na íntegra, e 26 atenderam aos critérios de elegibilidade e foram incluídos na presente revisão. Os AGEs devem ser considerados um dos principais fatores de risco cardiometabólico. A redução da interação AGE-RAGE resultará na proteção cardiovascular e no aumento da expectativa de vida.

Efectos patogénicos de los productos finales de glicación avanzada en el proceso de envejecimiento-enfermedad

RESUMEN Los productos finales de glicación avanzada -conocidos como productos de la reacción de Maillard-, formados por glicación directa no enzimática de azúcares reductores con grupos amino libres de proteínas, provocan cambios estructurales y funcionales en las mismas, cuya producción endógena es incrementada con la edad, el estrés oxidativo, así como por factores externos, provocando envejecimiento prematuro y enfermedades degenerativas. El objetivo de la revisión fue obtener una visión actualizada de los avances en investigaciones sobre los efectos de productos finales de glicación avanzada y su interrelación con el estrés oxidativo en el proceso de envejecimiento-enfermedad. En la revisión se consideraron los principales artículos más recientes sobre el tema en las bases de datos PubMed, SciELO, ClinicalKey y LILACS. Se evidencian los efectos patogénicos de los productos finales de glicación avanzada que contribuyen al estrés oxidativo y a la inflamación, de forma especial en el envejecimiento prematuro, diabetes, enfermedad cardiovascular y en otras enfermedades neurodegenerativas, como un aspecto preocupante en el tema del envejecimiento poblacional y su enorme costo para la sociedad futura.

ABSTRACT The advanced glycation end-products-known like products of the Maillard reaction-formed by a direct non-enzymatic glycation of reducing sugars with amino groups free of proteins, cause structural and functional changes in them, whose endogenous production is incremented with age, oxidative stress, as well as by external factors, causing premature aging and degenerative diseases. The objective of the review objective was to obtain an updated view of the advances in research on the effects of the advanced glycation end products and their interrelation with the oxidative stress in the aging-disease process. In the review the authors considered the most recent leading articles on the topic published in the databases PubMed, SciELO, ClinicalKey and LILACS. The pathogenic effects of the advanced glycation end products that contribute to oxidative stress and inflammation are evidenced, especially in premature aging, diabetes, cardiovascular disease and other neurodegenerative diseases, as a worrying aspect in the issue of population aging and its enormous cost for future society.

Improvements on Glycation by Thermal Effects of Balneotherapy ─Ａ Pilot Study─ / 日本温泉気候物理医学会雑誌

  Objective: We investigated the effects of 5 days of spa therapy on the glycation reaction and oxidative balance defense system.  Subjects: The subjects were divided into a glucose spikes group (S group: 5 cases) and non-glucose spike group (non-S group: 6 cases), and a comparative study was conducted.  Method: The subjects stayed at the Inubosaki Onsen “Superb View Inubosaki Hotel” for 5 days and took spa baths twice a day for 20 min (balneotherapy). Before and after the baths, the degree of glycation was measured. Erythrocyte deformation by dark field microscope was classified into stages between 0 and 5, and the state of deformation and the levels of advanced glycation end products (AGEs) were measured. In addition, the oxidative stress (reactive oxygen metabolites, d-ROM), antioxidant power (biological antioxidant potential, BAP), and latent antioxidant capacity (BAP/d-ROM ratio) were also measured.  Result: The red blood cell images before balneotherapy were worse in the S group, but there was no significant difference in the AGE values. There was also no significant difference between the two groups in terms of the oxidative balance defense system. A comparison before and after balneotherapy showed that the red blood cell images significantly improved from 3 (3-3) (median (IQR)) to 2 (1-2)°in the S group. Oxidative stress also significantly improved in group S from 342 (334-362) to 314 (303-345) CARR U. In the non-S group, the AGE value improved significantly from 0.52 (0.48-0.59) to 0.5 (0.43-053) a.u. There were no significant differences in the other items.  Discussion: Changes in red blood cell images are considered to reflect changes in the early reactions of glycation, and AGEs may be evaluated as representing whole early and late reactions of glycation. In the S group, the early reaction improved, and in the non-S group, the entire glycative reaction was effective. Although the each mechanism of blood glucose to different, balneotherapy was shown to be effective in improving glycation.

Antiglycation and antioxidant activities of the crude extract and saponin fraction of Tribulus terrestris before and after microcapsule release / 中西医结合学报

OBJECTIVE@#The present study investigated antiglycation and antioxidant activities of crude dry extract and saponin fraction of Tribulus terrestris. It also developed a method of microencapsulation and evaluated antiglycation and antioxidant activities of crude dry extract and saponin fraction before and after microcapsule release.@*METHODS@#Antiglycation activity was determined by relative electrophoretic mobility (REM), free amino groups and inhibition of advanced glycation end-product (AGE) formation. Antioxidant activity was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric ion-reducing antioxidant power (FRAP), nitric oxide (NO) and thiobarbituric acid reactive species (TBARS) tests. Microcapsules were prepared using maltodextrin as wall material and freeze-drying as encapsulation technique. Morphological characterization of microcapsules was evaluated by scanning electron microscopy, and encapsulation efficiency and microcapsule release were determined by total saponins released. Antiglycation and antioxidant assays were performed using crude dry extract and saponin fraction of T. terrestris before and after release.@*RESULTS@#Saponin fraction showed an increase of 32.8% total saponins. High-performance liquid chromatography-mass spectrometry analysis showed the presence of saponins in the obtained fraction. Antiglycation evaluation by REM demonstrated that samples before and after release presented antiglycation activity similar to bovine serum albumin treated with aminoguanidine. Additionally, samples inhibited AGE formation, highlighting treatment with saponin fraction after release (89.89%). Antioxidant tests demonstrated antioxidant activity of the samples. Crude dry extract before encapsulation presented the highest activities in DPPH (92.00%) and TBARS (32.49%) assays. Saponin fraction before encapsulation in FRAP test (499 μmol Trolox equivalent per gram of dry sample) and NO test (15.13 μmol nitrite formed per gram of extract) presented the highest activities.@*CONCLUSION@#This study presented antiglycation activity of crude dry extract and saponin fraction of T. terrestris, besides it demonstrated promising antioxidant properties. It also showed that the encapsulation method was efficient and maintained biological activity of bioactive compounds after microcapsule release. These results provide information for further studies on antidiabetic and antiaging potential, and data for new herbal medicine and food supplement formulations containing microcapsules with crude extract and/or saponin fraction of T. terrestris.

Effects of C3aR and receptor for advanced glycation end products on bone metabolism in APP/PS1 mice models of Alzheimer′s disease / 中华内分泌代谢杂志

Objective:To investigate the effects of complement C3a receptor(C3aR) and receptor for advanced glycation end product(RAGE) on bone metabolism in APP/PS1 mice model of Alzheimer′s disease.Methods:Alzheimer′s disease model APP/PS1 mice was hybridized with C3aR knockout mice(C3aR -/-), RAGE knockout mice(RAGE -/-) to generate APP/PS1-C3aR -/- and APP/PS1-RAGE -/-, respectively. In vivo, micro computed tomography(Micro-CT) scan, bone tissue osteocalcin immunohistochemical staining, tartrate-resistant acid phosphatase(TRAP) staining and Goldner′s trichrome staining were used to understand the variabilities of bone metabolism between different genotypes of mice; In vitro, bone marrow-derived osteoblast and osteoclast induction cultures were used to understand the effects of C3aR and RAGE on osteoblast and osteoclast differentiation. Results:In in vivo experiments, APP/PS1-C3aR -/- and APP/PS1-RAGE -/- mice showed increased bone mass, increased bone formation, decreased bone resorption, and increased osteoid compared to APP/PS1 mice( P<0.05). In in vitro experiments, bone marrow mesenchymal stem cells(BMSCs) derived from APP/PS1-C3aR -/- and APP/PS1-RAGE -/- mice showed enhanced osteoblast differentiation and elevated expression levels of alkaline phosphatase(ALP) and runt-related transcription factor 2(RUNX2), diminished osteoclast differentiation, and reduced positive TRAP staining( P<0.05). Conclusions:Both C3aR and RAGE are involved in regulating the process of APP/PS1 bone metabolism. Knockout of C3aR and RAGE can improve osteoporosis in APP/PS1, providing a new target for the clinical treatment of Alzheimer′s disease combined with osteoporosis.

Mechanism of 3-arylcoumarin derivatives inhibiting vascular calcification / 中国药科大学学报

@#To reveal the pharmacological mechanism of 3-arylcoumarin derivative 3-(4′-hydroxyphenyl)-6-hydroxycoumarin (SJ-6) against vascular calcification, advanced glycation end products (AGEs) were used to induce the calcification of human aortic vascular smooth muscle cells (HCASMCs), and calcification was identified by alizarin red staining and quantification.The effects of SJ-6 on alkaline phosphatase (ALP) activity, cell proliferation rate, calcium content, and total reactive oxygen species (ROS), superoxide dismutase (SOD), AGEs, and tetra methylethlene diamine proteinase factor-α (TNF-α), interleukin-6 (1L-6), interleukin-β (1L-β), runt-related transcription factor 2 mRNA (Runx2 mRNA), the receptor of advanced glycation endproducts (RAGE), nuclear factor kappa-B (NF-κB), napdh oxidase-1 (NoX-1), protein kinase C(PKC), protein kinase b(AKT), p38 mitogen-activated protein kinase (p38 MAPK), and smooth muscle actin-α (SMA-α) protein expression were determined.According to our results, SJ-6 significantly decreased AGEs content, ALP activity, intracellular calcium content, ROS content, Runx2 mRNA and inflammatory factors TNF-α, 1L-6 and 1L-β (P < 0.05) and increased SOD content (P < 0.01), with similar to those of the positive control drug aminoguanidine hydrochloride (AGH).Therefore, we investigated the pharmacological mechanism of compound SJ-6, which was found to significantly inhibit the expression of RAGE, NF-κB, NoX-1, PKC, Akt, p-p38 and other essential signaling proteins in the calcified cell model (P < 0.01) and increas the expression of smooth actin SMA-α (P < 0.01).SJ-6 inhibits vascular calcification by inhibiting oxidative stress and the expression of AGEs/RAGE, Akt/PKC and NF-κB signaling pathways, suggesting that it may be a novel drug for the treatment of vascular calcification.

The Value of Serum HMGB1 and sRAGE in the Diagnosis, Efficacy Monitoring and Prognosis of Newly Diagnosed Multiple Myeloma / 中国实验血液学杂志

OBJECTIVE@#To evaluate the value of high mobility group protein B1 (HMGB1) and soluble receptor for advanced glycation end products (sRAGE) in the diagnosis, efficacy monitoring and prognosis of newly diagnosed multiple myeloma (MM) patients.@*METHODS@#Fifty newly diagnosed MM patients before and after chemotherapy and 50 hematological outpatients from October 2018 to May 2020 were selected. Enzyme linked immunosorbent assay (ELISA) was used to detect the serum HMGB1 and sRAGE levels of the patients. ROC was used to further analyze the efficacy of serum HMGB1 and sRAGE levels on the diagnosis of MM. At the same time, the serum levels of HMGB1 and sRAGE before and after chemotherapy were compared, and their values in the evaluation of curative effect of MM patients were analyzed. According to the mean values of serum HMGB1 and sRAGE, all the patients were divided into different groups, the clinical characteristics and survival status of the patients were compared.@*RESULTS@#Before treatment the serum HMGB1 level of the patients in MM group was higher than that in control group, while sRAGE level was lower (t=11.363,6.127, P<0.001). The AUC of serum HMGB1 and sRAGE in the MM patients was 0.955 and 0.811, respectively. After 3 courses of chemotherapy, HMGB1 level of the patients in CR group was lower than before chemotherapy, while in PD group was higher, as well as sRAGE level of the patients in PR group (P<0.05). There were significant differences in R-ISS stage, HGB, CRP, ESR, CD56, CD117, D13S319 deletion between HMGB1 high expression group and HMGB1 low expression group (χ2=3.920, 6.522, 6.65, 4.16, 3.945, 6.65, 4.16, P<0.05), while there were significant differences in ISS stage, CRP and CD56 between sRAGE low expression group (28 cases) and sRAGE high expression group (22 cases) (χ2=4.565, 4.711, 5.547, P<0.05). Kaplan-Meier survival analysis showed that the patients in HMGB1 low expression group had better survival condition, for PFS Tlow>Thigh (χ2=9.470, P<0.05), and for OS Tlow>Thigh (χ2=7.808, P<0.05); there was no difference in the survival of sRAGE high expression group and low expression group, for PFS Tlow<Thigh (χ2=1.661, P>0.05), and for OS Tlow<Thigh (χ2=2.048, P>0.05). Cox analysis showed that LDH and HMGB1 were the factors affecting the prognosis of the patients, and both of them affected PFS (HR=2.771, 95% CI: 1.002-7.662, P=0.049; HR=6.022, 95% CI: 1.689-21.470, P=0.006), while HMGB1 also affected OS (HR=4.275, 95% CI: 1.183-15.451, P=0.027).@*CONCLUSION@#The serum HMGB1 and sRAGE have certain auxiliary value for the diagnosis and curative effect monitoring of newly diagnosed MM patients, and serum HMGB1 is expected to be an auxiliary detection index for the prognosis of MM.

Design, simulation and application of multichannel microfluidic chip for cell migration / 生物医学工程学杂志

Cell migration is defined as the directional movement of cells toward a specific chemical concentration gradient, which plays a crucial role in embryo development, wound healing and tumor metastasis. However, current research methods showed low flux and are only suitable for single-factor assessment, and it was difficult to comprehensively consider the effects of other parameters such as different concentration gradients on cell migration behavior. In this paper, a four-channel microfluidic chip was designed. Its characteristics were as follows: it relied on laminar flow and diffusion mechanisms to establish and maintain a concentration gradient; it was suitable for observation of cell migration in different concentration gradient environment under a single microscope field; four cell isolation zones (20 μm width) were integrated into the microfluidic device to calibrate the initial cell position, which ensured the accuracy of the experimental results. In particular, we used COMSOL Multiphysics software to simulate the structure of the chip, which demonstrated the necessity of designing S-shaped microchannel and horizontal pressure balance channel to maintain concentration gradient. Finally, neutrophils were incubated with advanced glycation end products (AGEs, 0, 0.2, 0.5, 1.0 μmol·L -1), which were closely related to diabetes mellitus and its complications. The migration behavior of incubated neutrophils was studied in the 100 nmol·L -1 of chemokine (N-formylmethionyl-leucyl-phenyl-alanine) concentration gradient. The results prove the reliability and practicability of the microfluidic chip.

Current status on the laboratory determination of advanced glycation end products / 中华检验医学杂志

The concentration and accumulation rate of advanced glycation end products (AGEs) in the body are highly correlated with glycometabolic disorders. Therefore, the clinical detection of AGEs is of great value for the early diagnosis and prognostic evaluation of these diseases. However, due to the complexity of its structure, the diversity of glycosylation sites, and the limitations of existing detection methods, there is still a lack of widely available detection methods in clinical practice. Starting from the structure and classification of AGEs and the value of clinical testing, this article summarizes current status of various laboratory detection methods of AGEs, and the deficiencies and challenges of these testing methods, future directions are further prospected.