Presence Of Carboxymethyl)lysine Research Articles

Enhancing Wound Healing and Anti-Inflammatory Effects by Combination of CIGB-258 and Apolipoprotein A-I against Carboxymethyllysine Toxicity in Zebrafish: Insights into Structural Stabilization and Antioxidant Properties.

CIGB-258 is known to exert anti-inflammatory activity via structural stabilization of apolipoprotein A-I (apoA-I) and functional enhancement of high-density lipoproteins (HDL) against acute toxicity of carboxymethyllysine (CML). The co-presence of CIGB-258 in reconstituted HDL (rHDL) formed larger rHDL particles and enhanced anti-inflammatory activity in a dose-dependent manner of apoA-I:CIGB-258, 1:0, 1:0.1, 1:0.5, and 1:1 of molar ratio, in the synthesis of the rHDL. However, no study has evaluated the enhancement of HDL functionality by the co-presence of lipid-free apoA-I and CIGB-258. The present study was therefore designed to compare the structural stabilization and functional improvement of HDL in the presence of lipid-free apoA-I and CIGB-258 in molar ratios of 1:0, 1:0.1, 1:0.5, and 1:1 within both HDL2 and HDL3. As the concentration of CIGB-258 increased, it effectively inhibited the cupric-ion-induced oxidation of HDL, thereby safeguarding apoA-I from proteolytic degradation. Additionally, the wound-healing activity of zebrafish was significantly (p < 0.01) enhanced by the co-addition of apoA-I:CIGB-258 (1:1) up to 1.6-fold higher than apoA-I alone (1:0) under the presence of CML. ApoA-I:CIGB-258 (1:1) treatment exhibited the lowest apoptosis and production of reactive oxygen species against CML-induced damage in the wound site. Also, an increase in wounded tissue granulation and epidermis thickness was observed with increasing concentration of CIGB-258 during 48 h post-treatment via the healing process. Intraperitoneal injection of apoA-I:CIGB-258 mixture remarkably ameliorated the acute paralysis and restored zebrafish swimming ability impaired by the acute toxicity of CML. The increase of CIGB-258 content, especially co-injection of apoA-I:CIGB-258 (1:1), leads to a significant 2.3-fold (p < 0.001) and 4.1-fold (p < 0.001) higher zebrafish survivability and recovery of swimming ability, respectively, than those of CML-control. In the apoA-I:CIGB-258 (1:1) group, neutrophil infiltration and interleukin (IL)-6 production was lowest in the hepatic tissue with the least cellular damage and apoptosis. Additionally, the group treated with apoA-I:CIGB-258 (1:1) demonstrated the lowest plasma levels of total cholesterol (TC) and triglycerides (TG), along with minimal damage to the kidney, ovary, and testicular cells. Conclusively, co-treatment of CIGB-258 with apoA-I effectively mitigated acute inflammation in zebrafish, safeguarded vital organs, structurally stabilized apoA-I, and enhanced HDL functionality.

Cuban Policosanol (Raydel®) Exerts Higher Antioxidant and Anti-Glycation Activities than Chinese Policosanol (BOC Sciences) in Reconstituted High-Density Lipoproteins: In Vivo Anti-Inflammatory Activities in Zebrafish and Its Embryos.

The present study compares sugarcane-wax purified policosanols sourced from Cuba (Raydel®) and China (BOC Sciences) and utilized following the synthesis of reconstituted high-density lipoproteins (rHDL). The two policosanols exhibited distinctly different ingredient ratios of long-chain aliphatic alcohols, particularly 1-octacosanol (C28) and 1-tetratriacotanol (C34). After synthesizing rHDL with apolipoprotein A-I (apoA-I), the two policosanols bound well with phospholipid and apoA-I to form the discoidal rHDL. Notably, rHDL-1, containing Cuban policosanol, displayed the largest particle diameter at approximately 78 ± 3 nm. In contrast, both control rHDL (rHDL-0) and rHDL containing Chinese policosanol (rHDL-2) exhibited smaller particles, with diameters of approximately 58 ± 3 nm and 61 ± 2 nm, respectively. Furthermore, rHDL-1 demonstrated enhanced anti-glycation activity, safeguarding apoA-I from degradation within HDL, and displayed the antioxidant ability to inhibit LDL oxidation. A microinjection of each rHDL into zebrafish embryos in the presence of carboxymethyllysine (CML) revealed rHDL-1 to have the strongest antioxidant activity with the highest embryo survivability and normal developmental morphology. Dermal application to recover the wound revealed rHDL-1 to have the highest wound-healing activity (75%) and survivability (92%) in the cutaneous wound area in the presence of CML. In adult zebrafish, injecting CML (250 μg) caused acute death and hyperinflammation, marked by heightened neutrophil infiltration and interleukin (IL)-6 production in liver. However, co-administering rHDL-1 notably increased survival (85%) and exhibited strong anti-inflammatory properties, reducing IL-6 production while improving the blood lipid profile. However, a co-injection of rHDL-2 resulted in the lowest survivability (47%) with more hepatic inflammation. In conclusion, Cuban policosanol (Raydel®) has more desirable properties for the in vitro synthesis of rHDL with stronger anti-glycation and antioxidant activities than those of Chinese policosanol (BOC Sciences). Moreover, Raydel-policosanol-integrated rHDL demonstrates a noteworthy effect on accelerated wound healing and robust anti-inflammatory properties, leading to increased survivability in zebrafish embryos and adults by effectively suppressing CML-induced hyperinflammation.

Comparison of Policosanols via Incorporation into Reconstituted High-Density Lipoproteins: Cuban Policosanol (Raydel®) Exerts the Highest Antioxidant, Anti-Glycation, and Anti-Inflammatory Activity.

Reconstituted high-density lipoproteins (rHDL) containing each policosanol from Cuba (Raydel®), China (Shaanxi Pioneer), and the United States (Lesstanol®) were synthesized to compare the physiological properties of policosanol depending on sources and origin countries. After synthesis with apolipoproteinA-I (apoA-I) into rHDL, all policosanols bound well with phospholipid and apoA-I to form discoidal rHDL. An rHDL containing Cuban policosanol (rHDL-1) showed the largest rHDL particle size of around 83 ± 3 nm, while rHDL containing Chinese policosanol (rHDL-2) or American policosanol (rHDL-3) showed smaller particles around 63 ± 3 nm and 60 ± 2 nm in diameter, respectively. The rHDL-1 showed the strongest anti-glycation activity to protect the apoA-I degradation of HDL from fructose-mediated glycation: approximately 2.7-times higher ability to suppress glycation and 1.4-times higher protection ability of apoA-I than that of rHDL-2 and rHDL-3. The rHDL-1 showed the highest antioxidant ability to inhibit cupric ion-mediated LDL oxidation in electromobility and the quantification of oxidized species. A microinjection of each rHDL into a zebrafish embryo in the presence of carboxymethyllysine (CML) showed that rHDL-1 displayed the strongest anti-oxidant activity with the highest embryo survivability, whereas rHDL-2 and rHDL-3 showed much weaker protection ability, similar to rHDL alone (rHDL-0). An intraperitoneal injection of CML (250 μg) into adult zebrafish caused acute death and hyperinflammation with an elevation of infiltration of neutrophils and IL-6 production in the liver. On the other hand, a co-injection of rHDL-1 resulted in the highest survivability and the strongest anti-inflammatory ability to suppress IL-6 production with an improvement of the blood lipid profile, such as elevation of HDL-C and lowering of the total cholesterol, LDL-cholesterol, and triglyceride. In conclusion, Cuban policosanol exhibited the most desirable properties for the in vitro synthesis of rHDL with the stabilization of apoA-I, the largest particle size, anti-glycation against fructation, and antioxidant activities to prevent LDL oxidation. Cuban policosanol in rHDL also exhibited the strongest in vivo antioxidant and anti-inflammatory activities with the highest survivability in zebrafish embryos and adults via the prevention of hyperinflammation in the presence of CML.

Long-Term Supplementation of Ozonated Sunflower Oil Improves Dyslipidemia and Hepatic Inflammation in Hyperlipidemic Zebrafish: Suppression of Oxidative Stress and Inflammation against Carboxymethyllysine Toxicity.

Ozonated sunflower oil (OSO) is a well-known functional oil with antioxidant, antimicrobial, anti-allergic, and skin-moisturizing properties. However, studies on the effects of OSO on high-cholesterol diet (HCD)-induced metabolic disorders have been scarce. In the current study, we aimed to determine the anti-inflammatory effects of OSO on lipid metabolism in adult hypercholesterolemic zebrafish and its embryos. Microinjection of OSO (final 2%, 10 nL) into zebrafish embryos under the presence of carboxymethyllysine (CML, 500 ng) protected acute embryo death up to 61% survival, while sunflower oil (final 2%) showed much less protection at around 42% survival. The microinjection of OSO was more effective than SO to inhibit reactive oxygen species (ROS) production and apoptosis in the CML induced embryo toxicity. Intraperitoneal injection of OSO under the presence of CML protected acute death from CML-induced neurotoxicity with improved hepatic inflammation, less detection of ROS and interleukin (IL)-6, and lowering blood total cholesterol (TC) and triglyceride (TG), while the SO-injected group did not protect the CML-toxicity. Long-term supplementation of OSO (final 20%, wt/wt) with HCD for 6 months resulted in higher survivability than the HCD alone group or HCD + SO group (final 20%, wt/wt) with significant lowering of plasma TC and TG levels. The HCD + OSO group showed the least hepatic inflammation, fatty liver change, ROS, and IL-6 production. In conclusion, short-term treatment of OSO by injection exhibited potent anti-inflammatory activity against acute neurotoxicity of CML in zebrafish and their embryo. Long-term supplementation of OSO in the diet also revealed the highest survivability and blood lipid-lowering effect through potent antioxidant and anti-inflammatory activity.

Cuban Sugar Cane Wax Alcohol Exhibited Enhanced Antioxidant, Anti-Glycation and Anti-Inflammatory Activity in Reconstituted High-Density Lipoprotein (rHDL) with Improved Structural and Functional Correlations: Comparison of Various Policosanols

Policosanols from various sources, such as sugar cane, rice bran, and insects, have been marketed to prevent dyslipidemia, diabetes, and hypertension by increasing the blood high-density lipoproteins cholesterol (HDL-C) levels. On the other hand, there has been no study on how each policosanol influences the quality of HDL particles and their functionality. Reconstituted high-density lipoproteins (rHDLs) with apolipoprotein (apo) A-I and each policosanol were synthesized using the sodium cholate dialysis method to compare the policosanols in lipoprotein metabolism. Each rHDL was compared regarding the particle size and shape, antioxidant activity, and anti-inflammatory activity in vitro and in zebrafish embryos. This study compared four policosanols including one policosanol from Cuba (Raydel® policosanol) and three policosanols from China (Xi'an Natural sugar cane, Xi'an Realin sugar cane, and Shaanxi rice bran). The synthesis of rHDLs with various policosanols (PCO) from Cuba or China using a molar ratio of 95:5:1:1 with palmitoyloleoyl phosphatidylcholine (POPC): free cholesterol (FC): apoA-I:PCO (wt:wt) showed that rHDL containing Cuban policosanol (rHDL-1) showed the largest particle size and the most distinct particle shape. The rHDL-1 showed a 23% larger particle diameter and increased apoA-I molecular weight with a 1.9 nm blue shift of the maximum wavelength fluorescence than rHDL alone (rHDL-0). Other rHDLs containing Chinese policosanols (rHDL-2, rHDL-3, and rHDL-4) showed similar particle sizes with an rHDL-0 and 1.1-1.3 nm blue shift of wavelength maximum fluorescence (WMF). Among all rHDLs, the rHDL-1 showed the strongest antioxidant ability to inhibit cupric ion-mediated LDL oxidation. The rHDL-1-treated LDL showed the most distinct band intensity and particle morphology compared with the other rHDLs. The rHDL-1 also exerted the highest anti-glycation activity to inhibit the fructose-mediated glycation of human HDL2 with the protection of apoA-I from proteolytic degradation. At the same time, other rHDLs showed a loss of anti-glycation activity with severe degradation. A microinjection of each rHDL alone showed that rHDL-1 had the highest survivability of approximately 85 ± 3%, with the fastest developmental speed and morphology. In contrast, rHDL-3 showed the lowest survivability, around 71 ± 5%, with the slowest developmental speed. A microinjection of carboxymethyllysine (CML), a pro-inflammatory advanced glycated end product, into zebrafish embryos resulted in severe embryo death of approximately 30 ± 3% and developmental defects with the slowest developmental speed. On the other hand, the phosphate buffered saline (PBS)-injected embryo showed 83 ± 3% survivability. A co-injection of CML and each rHDL into adult zebrafish showed that rHDL-1 (Cuban policosanol) induced the highest survivability, around 85 ± 3%, while rHDL-0 showed 67 ± 7% survivability. In addition, rHDL-2, rHDL-3, and rHDL-4 showed 67 ± 5%, 62 ± 37, and 71 ± 6% survivability, respectively, with a slower developmental speed and morphology. In conclusion, Cuban policosanol showed the strongest ability to form rHDLs with the most distinct morphology and the largest size. The rHDL-containing Cuban policosanol (rHDL-1) showed the strongest antioxidant ability against LDL oxidation, anti-glycation activity to protect apoA-I from degradation, and the highest anti-inflammatory activity to protect embryo death under the presence of CML.

Atrial Fibrillation Coincides with the Advanced Glycation End Product Nε-(Carboxymethyl)Lysine in the Atrium

Presence of advanced glycation end products (AGEs) in the heart induces a proinflammatory phenotype. However, the presence of AGEs within atrial tissue of atrial fibrillation (AF) patients is unknown and was analyzed here. Left atrial appendage tissue from 33 AF patients and 9 controls was analyzed for the presence of the major AGEs N(ε)-(carboxymethyl)lysine (CML), VCAM-1, neutrophilic granulocytes, lymphocytes, and macrophages in both the fat tissue and myocardium separately. The total amount of fibrosis was also analyzed. Presence of CML was significantly higher in blood vessels of the left atrial appendage in AF patients as compared to controls, independent of diabetes mellitus. In AF patients, VCAM-1 expression in blood vessels and the numbers of infiltrated neutrophilic granulocytes, lymphocytes, and macrophages significantly increased compared to controls, and were highest in the fat tissue; there was no significant difference in fibrosis compared to controls. Interestingly, total amount of CML and fibrosis in AF and control patients correlated positively. Finally, there was no difference between AF patients based on AF type or surgical indication in the presence of CML, VCAM-1 expression, inflammatory cells, and fibrosis. Our results indicate that in AF the intramyocardial blood vessels of the left atrial appendage have an increased CML presence and proinflammatory status coinciding with a local increase in the number of inflammatory cells.

Formula-derived advanced glycation end products are involved in the development of long-term inflammation and oxidative stress in kidney of IUGR piglets.

Formula-derived dietary advanced glycation end products (AGEs) may promote programming of inflammation and oxidative stress in the kidney of intrauterine growth retardation (IUGR) piglets. IUGR piglets received either a low temperature heated formula (n = 8) or a high temperature heated formula (HHF: n = 8) or suckled naturally for 3 wk postnatally. Then they were fed with normal ad libitum regular diet. N(ε)-carboxymethyllysine (CML) was measured in plasma, feces, and formula by HPLC/MS-MS. CML was detected by immunofluorescence in kidney cells. Target renin-angiotensin-apoptotic, pro-inflammatory genes-p62 NF-κB, and soluble receptor of AGE (sRAGE) levels were quantified. Compared with that in controls, free CML and plasma urea increased significantly in the HHF-fed group at PND36 (p < 0.05). CML was detected in the nuclei of renal tubular cells of formula-fed piglets but not in suckled ones. This presence of CML was associated with the activation of the soluble receptor of AGE. AT1, AT2, caspase 3, caspase 8, NF-κB, p62 NF-κB, and total protein oxidation in kidney were higher in HHF-fed group as compared to LHF-fed group (p < 0.05). Food processes aimed at reducing the concentration of AGEs in infant formula are urgently needed and may be therapeutically relevant for premature and/or IUGR babies.

The presence of Nε-(Carboxymethyl) lysine in the human epidermis

It is well known that advanced glycation end products (AGEs) are formed in long-lived dermal proteins such as collagen, and that their formation is related to skin aging. To examine the distribution of AGEs in skin tissue, we performed immunofluorescence studies on the human skin using an anti-AGEs antibody. Interestingly, AGEs signals were observed not only in the dermis but also in the epidermis. The objectives of this study were to confirm the presence of N ε-(Carboxymethyl) lysine (CML), an AGE structure, in the epidermis and to characterize the CML-modified proteins. The presence of CML in the stratum corneum (SC) was examined using liquid chromatography–electrospray ionization time-of-flight mass spectrometry. Concordance between the retention times of a compound in the SC hydrolysate and authentic CML, as well as with the specific mass transition of CML, was detected. This result showed that CML is present in the epidermis. In order to characterize the CML-modified proteins in the epidermis, protein samples extracted from the SC were analyzed using two-dimensional electrophoresis followed by an amino acid sequence analysis. The clarified peptide sequences covered approximately 27% of the amino acid sequences of cytokeratin 10 (K10). In the immunoblotting experiment following the two-dimensional electrophoresis, where protein samples extracted from whole epidermis were used, the position of the major CML-positive spots corresponded to those of K10. Taken together these results showed that CML is present in the human epidermis, and suggest that K10 is one of the target molecules for CML modification in the epidermis.

Advanced Glycation Endproduct in Soleus Muscle of Diabetic Sedentary and Diabetic, Endurance-trained Rats

Carboxymethyl-lysine (CML) is an advanced glycation end product (AGE), the accumulation of which has been implicated in the etiology of diabetes complications. The presence of CML is related to the binding of sugars to proteins or lipids, and also is a marker of oxidative stress. It has previously been shown that the contractile properties of skeletal muscle are altered in animal models of diabetes. Immunohistochemistry has also identified increased accumulation of CML in theplantaris muscles of diabetic animals. Aim: This study aims to further explore the accumulation of CML in diabetic animals with and without insulin, and with endurance training. METHODS: Animals were randomly divided into control and diabetes groups, and into sedentary and trained subgroups (DNI-diabetes/no insulin, DS-diabetes sedentary, DE-diabetes exercise, CS-control sedentary, CE-control exercise). Diabetes was induced by intravenous administration of streptozotocin. The sedentary animals were allowed their usual cage-based activity. One diabetes group was not given insulin (DNI), the other two diabetes groups received insulin. The exercise groups ran on a treadmill for 5 days/week at 27 m/min. The experimental period was 12 weeks. At the end of the experimental period the animals were sacrificed; the soleus muscle was excised and snap-frozen in liquid nitrogen. Muscle cross-sections were immunolabelled for CML. Muscle fibers labelling for CML were then quantified. RESULTS: Immuno labelling for CML was quantified as follows (expressed as percentage of total number of myofibers counted): DNI: 25.3%, CS: 4.1 %, DS: 4.6%, CE: 4.3%, DE: 3.2%. CONCLUSION: The greatest accumulation of AGE was in the soleus of the DNI group, and may be linked to the severity of disordered glucose metabolism, and/or to increased oxidative stress. The quantities of CML immunolabelling in the other diabetes groups were significantly lower than in the DNI group. This result appears to be related to the administration of insulin, which influences both glucose and protein metabolism. Since the amount of CML immunolabelling was similar between DS and DE groups, it appears that insulin may have a greater effect on CML accumulation than does endurance exercise.

Eales′ disease: Oxidant stress and weak antioxidant defence

Eales' disease (ED) is an idiopathic retinal periphlebitis characterized by capillary non-perfusion and neovascularization. In addition to the existing system, a new staging system has been proposed by Saxena et al. Immunological, molecular biological and biochemical studies have indicated the role of human leucocyte antigen, retinal S antigen autoimmunity, Mycobacterium tuberculosis genome, free radical damage and possibly hyperhomocysteinemia in its etiopathogenesis, which appears multifactorial. Oxidant stress has been shown by increase in the levels of thiobarbituric acid reactive substances (lipid oxidation) in the vitreous, erythrocytes, platelets and monocytes. A decrease in vitamins E and C both in active and healed vasculitis, superoxide dismutase, glutathione and glutathione peroxidase showed a weakened antioxidant defence. Epiretinal membrane from patients of ED who underwent surgery showed, by immunolocalization, presence of carboxy methyl lysine, an advanced glycation end product formed by glycoxidation and is involved in angiogenesis. OH. free radical accumulation in monocytes has been directly shown by electron spin resonance spectrometry. Free radical damage to DNA and of protein was shown by the accumulation of 8 hydroxy 2 deoxyguanosine (in leucocytes) and nitrotyrosine (in monocytes), respectively. Nitrosative stress was shown by increased expression of inducible nitric oxide synthase in monocytes in which levels of iron and copper were increased while those of zinc decreased. A novel 88 kDa protein was found in serum and vitreous in inflammatory condition and had antioxidant function. Platelet fluidity was also affected. Oral, methotrexate in low dosage (12.5 mg/week for 12 weeks) as well as oral vitamin E (400 IU) and C (500 mg) daily for 8 weeks are reported to have beneficial effects.

Nε-(Carboxymethyl)lysine depositions in human aortic heart valves: similarities with atherosclerotic blood vessels

Recent studies indicate a role of atherosclerosis-like changes involved in the pathogenesis of aortic valve stenosis. Interestingly, one of the major advanced glycation end products (AGEs), N ε-(carboxymethyl)lysine (CML) has been related to the process of atherosclerosis in blood vessels. In the present study, we have analyzed the presence of CML in degenerative altered aortic valves with atherosclerosis-like changes, and in degenerated mitral valves without atherosclerosis-like changes, derived from patients suffering from acute rheumatism during childhood. Degenerated and non-degenerated valves were derived from autopsy or obtained during cardiac surgery. The presence of CML was examined by immunohistochemistry. CML was found on the endothelium and fibroblasts in control aortic and mitral valves. Minor differences in CML staining were observed between control and degeneratively affected mitral valves. In contrast, in degenerated aortic valves, CML accumulation was found in macrophages and on calcification sites, comparable to that in atherosclerotic arteries, while the presence of CML staining on the endothelium and fibroblasts was significantly less as compared with control aortic valves. Our data support the hypothesis that the process of degeneration of aortic valves resembles that of atherosclerosis in blood vessels. They suggest that CML also plays a role in the process of atherosclerosis in aortic valves.

OXIDATION OF ALBUMIN IS ENHANCED IN THE PRESENCE OF UREMIC TOXINS

Albumin has been considered a “sacrificial plasma antioxidant” due to the high reactivity of the protein sulfhydryl groups with oxidants such as hydrogen peroxide (H2O2) and hypochlorous acid (HOCl). Based on its large quantity and high turnover. It is considered as one of the most important plasma antioxidants for protecting key cellular and regulatory proteins. Since hemodialysis patients have lower overall levels of albumin and possible protein modifications due to uremic toxins, we investigated whether modifications by various uremic toxins would affect the susceptibility of albumin to an oxidative challenge. We incubated bovine serum albumin in the presence of carboxymethyllysine (CML) (10 μmol/L–1 mmol/L), methyl glyoxal (50 μmol/L–5 mmol/L), p-cresol (100 μmol/L–10 mmol/L) or hippuric acid (200 μmol/L–20 mmol/L) for 16 hours at 37°C and then subsequently added 0.5 mmol/L–1 mmol of H2O2/HOCl. We measured the extent of protein modification by the loss of protein sulfhydryl groups, dityrosine formation and the formation of advanced oxidation protein products (AOPP). Incubation of albumin with the uremic toxins caused a loss of protein sulfhydryl groups and an increase in dityrosines and AOPP. The presence of uremic toxins had no effect on the loss of protein sulfhydryl groups after addition of H2O2/HOCl; however, low levels of CML, p-cresol and methyl glyoxal inhibited the formation of AOPP and dityrosines. We suggest that uremic toxins may possibly play a role in mediating free radical initiated protein damage.