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Skin fibroblasts from 18 scleroderma patients were seeded into collagen lattices and their ability to retract their substratum was compared with that of control fibroblasts from healthy donors. When considered as a whole, scleroderma fibroblasts retracted lattices earlier and more intensely than controls. Analysis of individual results demonstrated that morphea and diffuse systemic sclerosis (dSSc) fibroblasts had different kinetics of lattice retraction. Fibroblasts which contracted lattices more intensely than controls were found to produce increased levels of fibronectin. A comparison of the retraction of collagen lattices by fibroblasts from involved (IS) and uninvolved skin (US) of the same patients (n = 4) showed that those from IS retracted the lattices more than fibroblasts from normal donors, whereas a high variabilty was found with fibroblasts from US. The increased retraction of collagen lattices seems to be a feature of the more severe forms of scleroderma. [ABSTRACT FROM AUTHOR]

An introduction to the journal is presented which discusses various papers published within the issue, including one on the role of Maillard reaction in cardiovascular disease and aging, one on a novel high performance liquid chromatographic (HPLC) assay for fructosamine-3-kinase measurement, and another on changes in advanced glycation-end products (AGEs) in plasma and cerebrospinal fluid in trauma, cerebrovascular disease and Alzheimer's disease.

[Display omitted] • Dietary carboxymethyllysine (dCML) accumulation in organs and tissues is reversible. • dAGE intake may contribute to intestinal sensitivity to inflammation. • RAGE knockout reduces TNFα age-related inflammation in rodents. • dAGE intake causes only minimal changes in gut microbiota. • dAGE do not provoke unequivocally harmful effects in a healthy rodent model. Dietary advanced glycation end-products (dAGEs) accumulate in organs and are thought to initiate chronic low-grade inflammation (CLGI), induce glycoxidative stress, drive immunosenescence, and influence gut microbiota. Part of the toxicological interest in glycation products such as dietary carboxymethyl-lysine (dCML) relies on their interaction with receptor for advanced glycation end-products (RAGE). It remains uncertain whether early or lifelong exposure to dAGEs contributes physiological changes and whether such effects are reversible or permanent. Our objective was to examine the physiological changes in Wild-Type (WT) and RAGE KO mice that were fed either a standard diet (STD − 20.8 ± 5.1 µg dCML/g) or a diet enriched with dCML (255.2 ± 44.5 µg dCML/g) from the perinatal period for up to 70 weeks. Additionally, an early age (6 weeks) diet switch (dCML→STD) was explored to determine whether potential harmful effects of dCML could be reversed. Previous dCML accumulation patterns described by our group were confirmed here, with significant RAGE-independent accumulation of dCML in kidneys, ileum and colon over the 70-week dietary intervention (respectively 3-fold, 17-fold and 20-fold increases compared with controls). Diet switching returned tissue dCML concentrations to their baseline levels. The dCML-enriched diet had no significative effect on endogenous glycation, inflammation, oxidative stress or senescence parameters. The relative expression of TNFα , VCAM1 , IL6 , and P16 genes were all upregulated (∼2-fold) in an age-dependent manner, most notably in the kidneys of WT animals. RAGE knockout seemed protective in this regard, diminishing age-related renal expression of TNFα. Significant increases in TNFα expression were detectable in the intestinal tract of the Switch group (∼2-fold), suggesting a higher sensitivity to inflammation perhaps related to the timing of the diet change. Minor fluctuations were observed at family level within the caecal microbiota, including Eggerthellaceae, Anaerovoracaceae and Marinifilaceae communities, indicating slight changes in composition. Despite chronic dCML consumption resulting in higher free CML levels in tissues, there were no substantial increases in parameters related to inflammageing. Age was a more important factor in inflammation status, notably in the kidneys, while the early-life dietary switch may have influenced intestinal susceptibility to inflammation. This study affirms the therapeutic potential of RAGE modulation and corroborates evidence for the disruptive effect of dietary changes occurring too early in life. Future research should prioritize the potential influence of dAGEs on disease aetiology and development, notably any exacerbating effects they may have upon existing health conditions. [ABSTRACT FROM AUTHOR]

• Glyoxylic acid preferentially modifies lysine over arginine residues in BSA. • Glyoxal alone (300 mM) can convert up to 24% of BSA lysine into CML. • Glyoxal forms more fluorescent products in BSA compared with glyoxylic acid. • In rodent food fortified with glycated-BSA, CML declined 30% over 80 days storage. • 33% of dCML from glycated-BSA fortified food was excreted in mouse feces. This study investigated different methods to produce N ε -carboxymethyl-lysine (CML)-enriched bovine serum albumin (BSA) as alternatives to the classical approach using glyoxylic acid (GA) and sodium cyanoborohydride (NaBH 3 CN) which results in toxic hydrogen cyanide (HCN). The reaction of GA (6 mmol/L) and NaBH 3 CN (21 mmol/L) to produce CML remained the most effective with CML yields of 24–35%, followed by 13–24% using 300 mmol/L glyoxal (GO). GA promoted specific modification of lysine to CML, and fewer structural modifications of the BSA molecule compared with GO, as evidenced by fluorescence and proteomic analyses. GO promoted greater arginine modification compared with GA (76 vs 23%). Despite structural changes to BSA with GO, murine fecal clearance of CML was similar to literature values. Hence, BSA glycation with 300 mmol/L glyoxal is a suitable alternative to GA and NaBH 3 CN for generating CML-enriched protein free of HCN, but a CML-only fortification model remains to be described. [ABSTRACT FROM AUTHOR]

L’athérosclérose, le diabète, l’HTA, le tabac sont des facteurs de risque cardiovasculaire (CV) qui s’ajoutent aux conséquences de l’urémie chez l’adulte insuffisant rénal (IR). La carbamylation est amplifiée au cours de l’IR en raison de l’augmentation permanente de l’urée, source d’acide isocyanique qui se fixe sur les résidus lysine aboutissant à la formation d’homocitrulline (Hcit). L’augmentation d’Hcit augmente le risque CV et la mortalité des adultes en IRT. Ce phénomène peut être étudié de manière plus sensible chez les enfants IRC qui ne présentent pas les autres facteurs de risque CV. Les concentrations d’Hcit plasmatique ont été déterminées, par spectrométrie de masse, transversalement et longitudinalement, chez 114 enfants, de la cohorte 4 C (Cardiovascular Comorbidity in Children with CKD), âgés de 6 à 17 ans, ayant une IR de stade 3 à 5, avec changement de traitement vers la dialyse ( n = 55) ou vers la greffe ( n = 59). Les facteurs prédictifs de la variation de HCit ont été analysés par modélisation linéaire multivariée. Les concentrations d’Hcit sont inédependantes de l’âge mais corrélées au DFG à l’urée sanguine et à l’albumine sérique augmentant significativement de 277 ± 86 μmol/mol Lys au stade 3 à 634 ± 527 au stade 5. La dialyse diminue l’Hcit en moyenne de 14,6 % (−106 ± 226 en dialyse péritonéale vs −52 ± 169 μmol/mol Lys en hémodialyse, p < 0,05) et la transplantation en moyenne de 58,1 %. En conclusion, l’HCit est fortement inversement corrélées au DFG et à l’urée. La dialyse ne compense que partiellement le processus permanent de carbamylation, bien que la DP semble abaisser l’Hcit plasmatique plus efficacement que l’HD intermittente. Après la transplantation, l’HCit diminue rapidement vers des valeurs observées dans l’IRC stade 3. D’autres études sont en cours pour analyser le rôle de la carbamylation des protéines dans l’apparition d’une atteinte cardiovasculaire dans cette population pédiatrique. [ABSTRACT FROM AUTHOR]

Background Mast cells, the key cells of immediate hypersensitivity type reactions, have also been postulated to have a central role in influencing tissue remodelling and fibrosis occurring in the skin. Objective Our aim was to investigate the direct role of human mast cells (HMC) in skin fibrotic processes, by assessing the effects of the addition of the human mast cell line HMC-1 to human skin fibroblasts, and to identify the responsible mediators. Methods HMC-1 sonicates were added to human skin fibroblasts and the following parameters were evaluated: proliferation ([3 H]-thymidine), collagen synthesis ([3 H] proline), activity of matrix metalloproteinases (MMPs) (zymography) and tissue inhibitors of metalloproteinases (TIMPs) (reverse zymography), and collagen gel contraction. Results HMC-1 sonicate increased significantly both proliferation and collagen production in the human skin fibroblasts and these properties were not affected by heating of the sonicate (56 °C, 30 min, or 100 °C, 3 min). Two main mast cell mediators, histamine and tryptase, were found to be responsible for the increase in fibroblast proliferation and collagen production. HMC-1 sonicate did not display any pre-formed gelatinase activity, and its addition to the fibroblasts did not change their pro-MMP-2 and MMP-2 activity. On the other hand, HMC-1 were found to possess TIMP-1 and TIMP-2. Addition of HMC-1 had no effect on fibroblasts TIMP-1 but induced a dose-dependent increase of TIMP-2 activity. In addition, HMC-1 sonicate seeded together with the fibroblasts in tri-dimensional collagen gel significantly enhanced their contraction. Conclusion We have shown that human mast cells, by granule-stored and therefore quickly releasable mediators, increase human skin fibroblast proliferation, collagen synthesis, TIMP-2 and collagen gel contraction. Therefore, mast cells have a direct and potentiating role in skin remodelling and fibrosis. [ABSTRACT FROM AUTHOR]