Crocin, a natural molecule with potentially beneficial effects against skin ageing.

OBJECTIVE: Oxidative stress and low-grade chronic inflammation stand out as key features of physiological skin ageing. The aim of this study was to examine in normal human epidermal keratinocytes (NHEK) and human dermal fibroblasts (HDF) grown in vitro, the antioxidant and anti-inflammatory properties of crocin, a carotenoid glycoside responsible for the colour of saffron. Moreover, considering the newly emerging field of skin glycobiology and the presence of two gentiobiosyl moieties in crocin, the effect of crocin on NHEK glycosylation pathways was for the first time investigated. METHODS: The anti-inflammatory and antioxidant activities of crocin were evaluated by in vitro assays of antioxidation activities, ELISA and microarray analysis. The effect of crocin on keratinocyte glycobiology was evaluated by proprietary GLYcoDiag lectin technologies and microarray analysis. RESULTS: Crocin is endowed with antioxidant potential against reactive oxygen species, protects squalene against UVA-induced peroxidation and prevents the release of inflammatory mediators. The expression of NF-kB-related genes and glycosylation-related genes is modulated in the presence of crocin. CONCLUSION: Results could designate this molecule as a promising skin ageing prevention cosmetic agent. Of note, some of these effects could be mediated by protein O-glycosylation and interaction of crocin with osidic receptors of keratinocytes.

Skin involvement in scleroderma--where histological and clinical scores meet.

OBJECTIVES: A clinico-pathological study in diffuse systemic sclerosis (SSc) patients was performed to analyse whether the skin histological organization and the pro-fibrotic signals elicited by TGF-beta in fibroblasts vary according to the modified Rodnan skin score (mRSS). METHODS: Twenty-seven SSc patients underwent 45 skin biopsies with simultaneous measure of mRSS before or after treatment by immunosuppressive drugs, with or without autologous peripheral haematopoietic stem cell transplantation (HSCT). RESULTS: Double-blind optic microscopy analysis of the biopsies standard extracellular matrix stains allowed to define three histological subgroups: 6 with grade 1 weak fibrosis, 30 with grade 2 moderate fibrosis and 9 with grade 3 severe fibrosis. A significant (P < 0.0001) was identified between the grades of fibrosis and the mRSS. In skin fibroblast cultures, Smad3 phosphorylation levels, as well as mRNA steady-state levels of two transforming growth factor (TGF)-beta/Smad3 targets, COL1A2 and PAI-1, increased in parallel with the mRSS. When compared with pre-transplant values the degree of fibrosis observed after HSCT in the papillary and in the reticular dermis decreased in parallel with the fall in mRSS (n = 5 consecutive patients with repeated biopsies). CONCLUSIONS: The histological extent of skin fibrosis correlates closely with the mRSS. Both parameters appeared to regress after HSCT. The extent of TGF-beta signalling activation in SSc skin fibroblasts appears to parallel the severity of disease.

[Involvement of TGFbeta1 in fibrotic diseases: role of its effectors, the Smad proteins]. / Implication du TGFbeta1 dans les processus fibrotiques: rôle de ses effecteurs, les protéines Smad.

INTRODUCTION: Transforming Growth Factor beta 1 (TGFbeta1) is a key cytokine in the development of fibrotic diseases which are characterized by a pathological excess of extracellular matrix involving multiple organs. EXEGESIS: To induce its biological effects, TGFbeta1 interacts with Ser/Thr kinase receptor complexes. The polypeptide binding to the receptors induces TGFbeta intracellular mediator phosphorylation and namely Smad proteins. Upon phosphorylation the latter form protein complexes which are then translocated to the nucleus where they participate to matrix gene regulation. CONCLUSION: We will summarize the literature on the involvement of TGFbeta1 through the Smad proteins in fibrotic diseases.

Long-chain 3-hydroxyacylCoA dehydrogenase deficiency: a new case presenting with liver dysfunction, cholestasis and fibrosis.

UNLABELLED: A cholestatic 6-mo-old girl was admitted to our department because she recently presented with hypotonia and lethargy, apparently due to moderate and transient hypoglycaemia. Her urine contained 3-hydroxy-dicarboxylic acids of 12 to 14 carbons in length and her plasma acylcarnitine profile was consistent with long-chain 3-hydroxyacylCoA dehydrogenase deficiency. This diagnosis was confirmed by enzyme studies. This deficiency was due to a G1528C mutation on the paternal allele (mutation on the maternal allele as yet not identified). The patient improved dramatically with medium-chain triglyceride supplementation. CONCLUSION: Early cholestasis and hepatic fibrosis must lead to search for long-chain 3-hydroxyacylCoA dehydrogenase deficiency, particularly when hypoketotic hypoglycaemia is present.

Probing ligand-induced conformational changes of human CD38.

The lymphoid surface antigen CD38 is basically a NAD+glycohydrolase, which is also involved in the metabolism of cyclic ADP-ribose. Besides, this ecto-enzyme has potential signalling roles in T- and B-cells. Such multiple functions prompted us to study the molecular dynamics of the CD38 protein and especially the relationship between its ecto-enzymatic active site and its epitope, i.e. the binding site of most known anti-CD38 monoclonal antibodies. Both epitopic and enzymatic sites were shown to be degraded by proteases, such as trypsin or chymotrypsin. This sensitivity was almost entirely suppressed in the presence of substrates or inhibitors. Both sites were also degraded in the presence of reducing agents, as dithiothreitol. Inhibitory ligands induced the same resistance of both sites against reducing attack. The binding of CD38 ligands to the active site triggers therefore conformational changes that shield some backbone bonds and disulfide bridges against, respectively, proteolytic cleavage or reduction. This transconformation was found moreover to irreversibly take place after incubation with substrates such as NAD+ in the presence of dithiothreitol. The epitope remained preserved, while the enzymatic activity was lost. This inactivation probably resulted from the covalent trapping of the catalytically reactive intermediate in the active site (i.e. paracatalytic inactivation). These data have major implications in the knowledge of the CD38 structure, especially with regard to the location of disulfide bridges and their accessibility. Potential consequences of the conformational plasticity of CD38 should also be considered in its physiological functions such as signalling.

Upregulation of CD38 gene expression in leukemic B cells by interferon types I and II.

The activation antigen CD38, which has NAD+ glycohydrolase activity in its extracellular domain, is expressed by a large variety of cell types. Few investigations into the regulation of CD38 expression by physiologic stimuli have been reported. As the CD38 promoter contains potential binding sites for interferon (IFN) regulatory factor-1 (IRF-1), we investigated the influence of IFN type I (alpha and beta) and type II (gamma) on CD38 gene expression of leukemic B cells. Using the IFN-responsive B cell line Eskol, we found by RT-PCR analysis a rapid time-dependent induction in CD38 mRNA (starting at 6 h) with each type of IFN. This induction was independent of protein synthesis, suggesting that CD38 gene activation does not require IRF-1 but is merely under direct transcriptional regulation by latent IFN-inducible factors. mRNA stimulation was followed within 24 h by induction of membrane CD38, which coincided with rises of CD38-specific ectoenzymatic activities, that is, NAD+ glycohydrolase, (A/G)DP-ribosyl cyclase, and cyclic ADP ribose hydrolase activities. IFN failed to induce or upregulate the other CD38-related ectoenzymes analyzed, that is, CD39, CD73, CD157, and PC-1. Similarly, treatment of leukemic cells of patients with B chronic lymphocytic leukemia (B-CLL) with IFN resulted in an increase in CD38 mRNA mirrored by plasma membrane upregulation of CD38 and NAD+ glycohydrolase activity. Further investigation in relation to CD38 gene activation and B-CLL behavior remains to be defined.

[Recent ruptures of the anterior cruciate ligament. Suture technique on a reinforcement ligament. Results of a 5 years' experience]. / Ruptures récentes du ligament croisé antérieur. Technique de suture sur ligament de renfort. Résultats après cinq ans d'expérience.

225 patients with acute rupture of the anterior cruciate ligament were operated upon with a knitted polyester synthetic ligament (Ligastic) reinforced by a suture of the anterior cruciate ligament remnant. Five technical points must respected during the implantation of the ligament: isometry, direction of the femoral and tibial tunnels, absence of abrasion of the ligament in the notch, tensioning of the synthetic ligament equal to the natural cruciate ligament, careful suture of the remnants of the ruptured anterior cruciate around the synthetic ligament replacement. The functional results, according to the rating system of ARPEGE, demonstrated 8.6 on the stability scale, 8.1 for pain, 8.7 for mobility; 87 per cent of the competitors were able to return to their sport at the same level. There were no cases of acute synovitis. The patients were separated into three groups for evaluation: Group I--More than three years follow-up. Group II--More than two years follow-up. Group III--Less than two years follow-up. An anterior drawer test of less than 5 mm was observed in 85 per cent of Group I, 88 per cent of Group II, and 87 per cent of Group III. A negative jerk test was noted in 92 per cent of Group I, 95 per cent of Group II and 95 per cent of Group III. These differences were not statistically significant. On follow-up, a Lachman test of less than 5 mm was found respectively in 37 per cent, 70 per cent and 79 per cent; this difference was statistically significant. The relatively mediocre results of the Lachman test in Group I led us to follow a more precise isometric method. Postoperative cases were reexamined and demonstrated that the artificial ligament had become covered with an oriented fibrous tissue. The long-term outlook also depended on a successful restoration of proprioception in the repaired remnant of the anterior cruciate.

[Reconstruction of the anterior cruciate ligament. Determination of the pre- and peroperative femoral isometric point]. / Recontruction isométrique du ligament croisé antérieur. Détermination pré et per-opératoire du point fémoral.

This study attempted to determine the femoral isometric site by a simple, reliable and easily reproducible technique for the reconstruction of a torn anterior cruciate ligament (A.C.L.). Anatomoradiological studies showed that the posterior border of the lateral condyle corresponded with the third of a circle and that the center of this circle was named the "isometric point" (F). The variations of the intra-articular length of a ligament between the point F and the center of the A.C.L. tibial attachment did not exceed 2 mm. A radiological study on 50 normal patients knees X-Rayed at 0 degree and 90 degrees of flexion showed a length dependence of 1.5 mm in 84% and 2 mm maximum in 98%. Twenty patients with acute or chronic A.C.L. rupture were operated on; the isometric point F was determined by superimposing a template of circles on the posterior border of the condyle. An original guide allowed to drill a bony tunnel with a pin emerging at the exact previous point F. A per-operative X-Ray studied the good reliability of this guide. The measurements of the variations of length of the ligament between 0 degree and 110 degrees of flexion varied less than 5% in 18 patients, which confirms the good isometry of the reconstruction. On the basis of these data, we propose to improve the implantation of autogenous or synthetic ligament in A.C.L. reconstruction by the use of a pre-operative determination of the isometric femoral point and the use of a guide able to drill easily a bony tunnel at this exact pre-determined point.