Dermatologic adverse events: golimumab, friend or foe?

Golimumab is a fully human anti-TNF-alpha blocker that has demonstrated its efficacy in the treatment of numerous kinds of diseases. Although it is generally safe and well tolerated, various adverse events have been reported. The present aim is to improve the understanding of dermatologic adverse events associated with golimumab following a search of various scientific databases. This systematic review and meta-analysis shows that golimumab is associated neither with severe injection-site reactions nor with injection-site erythema. We found no significant lupus-like syndromes, and no significant skin squamous cell carcinoma. We further suggest systematic dermatologic monitoring in clinical practice during golimumab therapy. Subsequent research should employ a larger cohort of patients to ensure clear and significant future conclusions.

Golimumab therapy of rheumatoid arthritis: an overview.

Golimumab is a new approved humanized antibody for the treatment of rheumatoid arthritis (RA). This antibody belonging to biologic agents is raised against the pro-inflammatory cytokine tumour necrosis factor-alpha playing an essential role in the initiation of RA. To date, Golimumab administration for patients with RA, as indicated by USA Food and Drug Administration, is subcutaneous combined with methotrexate (MTX). Here, we have reviewed current literature with a focus on characteristics of Golimumab and also have exposed the clinical trials either using MTX or not using MTX. We have also highlighted the incoming clinical trials on Golimumab and have proposed some indications for the future studies based on a setting of clinical data and post-marketing observational studies. These studies will advance rheumatologists' decisions in the beginning of RA therapeutic interventions to insure the best outcomes for patients with RA and to improve their quality of life.

STIM1, Orai1 and hTRPC1 are important for thrombin- and ADP-induced aggregation in human platelets.

Ca(2+) entry, particularly store-operated Ca(2+) entry (SOCE), has been reported to be crucial for a variety of cellular functions. SOCE is a mechanism regulated by the Ca(2+) content of the stores, where the intraluminal Ca(2+) sensor STromal Interaction Molecule 1 (STIM1) has been reported to communicate the filling state of the intracellular Ca(2+) stores to the store-operated Ca(2+)-permeable channels in the plasma membrane, likely involving Orai1 and TRPC proteins, such as TRPC1. Here we have investigated the role of Orai1, STIM1 and TRPC1 in platelet aggregation, an event that occurs during the process of thrombosis and hemostasis. Electrotransjection of cells with anti-STIM1 (25-139) antibody, directed towards the Ca(2+)-binding motif, significantly reduced thrombin-induced aggregation and prevented ADP-evoked response. Extracellular application of the anti-STIM1 antibody, in order to block the function of plasma membrane-located STIM1, reduced thrombin- and ADP-stimulated platelet aggregation to a lesser extent. Introduction of an anti-Orai1 (288-301) antibody, which binds the STIM1-binding site located in the Orai1 C-terminus, or extracellular application of anti-hTRPC1 (557-571) antibody to impair hTRPC1 channel function, significantly reduced thrombin- and ADP-induced platelet aggregation. These findings suggest a role of STIM1, Orai1 and hTRPC1 in thrombin- and ADP-induced platelet aggregation probably through the regulation of Ca(2+) entry, which might become targets for the development of therapeutic strategies to treat platelet hyperactivity and thrombosis disorders.

[New antitumor agent: In vitro activity on breast carcinoma cells]. / Nouvel agent antitumoral : activité in vitro sur les cellules de carcinomes mammaires.

Previous work showed that established interactions between water-soluble polymers and cell membrane receptors can lead to modulate cell proliferation and differentiation in vitro. These polymers can be considered as bioactive. The aim of this work was to establish the consequences of the interactions between human breast cancer cells MCF7 and polymers of various chemical compositions regarding cell adhesion and proliferation onto tissue culture plate. Water soluble copolymers were synthesized by radical polymerization and are composed of methacrylic acid and sodium styrene sulphonate units. The modulation of the MCF7, biological-induced by these polymers of various compositions, was evaluated. The influence of the polymers chemical composition on the kinetics of cell proliferation, as well as cell morphology and spreading, were studied. A polymer concentration-dependent inhibition effect was observed. One hundred microgram per liter polymers solutions induced strong inhibition of cell proliferation, as well as a change of the MCF7 cells morphology, which can be related to an inhibition of cell spreading. The polymers/MCF7 cells interactions are modulated by the chemical composition of the copolymers and then the respective rate in sulphonate and carboxylate groups distributed along the macromolecular chain.

Cinnamtannin B-1 from bay wood exhibits antiapoptotic effects in human platelets.

Proanthocyanidins, such as cinnamtannin B-1, are polyphenolic compounds with antioxidant activity that induce apoptosis in a number of tumoral cells. We have now investigated the pro- or anti-apoptotic effects of cinnamtannin B-1 in human platelets. Platelet stimulation with thrombin induced cellular apoptosis, as detected by phosphatidylserine exposure and the activation of caspases-3 and -9. Pretreatment for 30 min with cinnamtannin B-1 impaired thrombin-induced apoptosis in platelets. Thrombin has been shown to induce H(2)O(2) generation in platelets, which induced similar apoptotic events than thrombin in these cells. Pretreatment with cinnamtannin B-1 reduced H(2)O(2)-induced phosphatidylserine exposure and caspase activation. Finally, platelet stimulation with thrombin induced translocation of caspases-3 and -9 to the cytoskeletal (Triton-insoluble) fraction, which is important for their activation and the development of apoptotic events. Pretreatment with cinnamtannin B-1 impaired translocation of caspases-3 and -9 to the cytoskeleton and, as a result, procaspases are accumulated in the Triton-soluble fraction. Our results provide evidence for the antiapoptotic actions of cinnamtannin B-1 in human platelets.

Cinnamtannin B-1 from bay wood reduces abnormal intracellular Ca2+ homeostasis and platelet hyperaggregability in type 2 diabetes mellitus patients.

Type 2 diabetes mellitus induces a number of cardiovascular disorders, including platelet hyperactivity and hyperaggregability, which is associated to an increased oxidant production and abnormal cytosolic Ca2+ mobilization. In the present study, we have investigated the effect of cinnamtannin B-1 obtained from bay wood on oxidants production, Ca2+ mobilization and aggregation in platelets from type 2 diabetic donors. Pretreatment of platelets with cinnamtannin B-1 reversed the enhanced oxidants production and Ca2+ mobilization, including Ca2+ entry, evoked by thapsigargin plus ionomycin or thrombin, observed in platelets from diabetic subjects, so that in the presence of cinnamtannin B-1 Ca2+ entry was similar in platelets from healthy and diabetic subjects. In addition, cinnamtannin B-1 reduced thrombin-induced aggregation in platelets from type 2 diabetic subjects. We conclude that cinnamtannin B-1 exerts an effective antioxidant action in platelets from patients with type 2 diabetes mellitus and reverses the enhanced Ca2+ mobilization and hyperaggregability.

Las aguas y sedimentos del río tunecino Hamdoun presentan riesgo de disrupción endocrina / Water and sediment waste rejected in Hamdoun’sriver are major endocrine disrupting system

Diversos estudios recientes sostienen que muchos productos químicos antropogénicos, presentes en el medio ambiente, imitan la acción de hormonas endógenas. Estos disruptores endocrinos pueden originar múltiples efectos adversos en la fauna, como la feminización de peces, la pérdida de capacidad reproductiva, defectos congénitos y, a veces, pueden estar en el origen de algunos tipos de cáncer en el ser humano. La aparición de intersexos en peces de varios ríos europeos se ha atribuido a la exposición a sustancias químicas estrogénicas presentes en los efluentes de estaciones de tratamiento de aguas residuales. Para profundizar en el efecto ambiental de estos contaminantes, hemos investigado la actividad estrogénica, de receptor de hidrocarburo arílico y de receptor X de pregnano, de muestras de agua y sedimentos del río Hamdoun, tomadas aguas arriba y aguas abajo de la zona de vertidos procedentes del área industrial de la región central de Túnez. Mediante un ensayo in vitro de células cancerosas bioluminiscentes que expresan el gen de la luciferasa bajo el control de ciertos elementos con acción hormonal, hemos detectado escasa actividad estrogénica en agua y sedimentos por encima de la zona de vertidos; sin embargo, encontram os fuerte actividad es trogénica, de receptor de hidrocarburo arílico y de receptor X de pregnano en agua y s edimentos río abajo. Con experimentos de com petición demostramos que, predominantemente, las muestras de agua y de sedimentos con actividad estrogénica contienen compuestos con alta y baja afinidad con el ER " recombinante, respectivamente. Estos resultados indican que el agua del río y los sedimentos constituyen un importante sumidero y pueden ser fuente potencial de contaminantes disruptores endocrinos(AU)

In recent years, many studies supported that anthropogenic chemicals occurring in the environment have been shown to mimic the action of endogenous hormones. These endocrine-disrupting chemicals can potentially lead to a host of adverse effects on wildlife, such as the feminization of fish, the lack of reproduction success, birth defects and sometimes they can be the origin of some kind of cancers in human. The occurrence of intersex fish in a number of European rivers has been attributed to the exposure to estrogenic chemicals present in sewage treatment work effluents. To further understand the environmental effect of these contaminants, the estrogenic, aryl hydrocarbon receptor and pregnane X receptor activities of water and sediments were investigated in this study. The water and sediment samples were obtained from upstream and downstream outfalls of the Hamdoun River located in proximity of the industrial area in the centre region of Tunisia. Using an in vitro assay with bioluminescent cancer cells expressing luciferase gene under different hormonal responsive element control, we detected a much lower level of estrogenic activity in water and sediment upstream, however, we found out a strong estrogenic, aryl hydrocarbon receptor and pregnane X receptor activities in water and sediment downstream this river. By using competition experiments, we demonstrated that estrogenic activity found contained mainly compounds with a strong and lower affinitiy in water and sediment respectively with the recombinant ER ". These results suggest that the river water and sediments are a major sink and could be a potential source of endocrine-disrupting chemicals contaminants(AU)

Fluorescence studies of the carboxyl-terminal domain of smooth muscle calponin effects of F-actin and salts.

The fluorescence parameters of the environment-sensitive acrylodan, selectively attached to Cys273 in the C-terminal domain of smooth muscle calponin, were studied in the presence of F-actin and using varying salt concentrations. The formation of the F-actin acrylodan labeled calponin complex at 75 mm NaCl resulted in a 21-nm blue shift of the maximum emission wavelength from 496 nm to 474 nm and a twofold increase of the fluorescent quantum yield at 460 nm. These spectral changes were observed at the low ionic strengths (< 110 mm) where the calponin : F-actin stoichiometry is 1 : 1 as well as at the high ionic strengths (> 110 mm) where the binding stoichiometry is a 1 : 2 ratio of calponin : actin monomers. On the basis of previous three-dimensional reconstruction and chemical crosslinking of the F-actin-calponin complex, the actin effect is shown to derive from the low ionic strength interaction of calponin with the bottom of subdomain-1 of an upper actin monomer in F-actin and not from its further association with the subdomain-1 of the adjacent lower monomer which occurs at the high ionic strength. Remarkably, the F-actin-dependent fluorescence change of acrylodan is qualitatively but not quantitatively similar to that earlier reported for the complexes of calponin and Ca2+-calmodulin or Ca2+-caltropin. As the three calponin ligands bind to the same segment of the protein, encompassing residues 145-182, the acrylodan can be considered as a sensitive probe of the functioning of this critical region. A distance of 29 A was measured by fluorescence resonance energy transfer between Cys273 of calponin and Cys374 of actin in the 1 : 1 F-actin-calponin complex suggesting that the F-actin effect was allosteric reflecting a global conformational change in the C-terminal domain of calponin.

Interaction of caldesmon with actin subdomain-2.

The polymerization-resistant maleimidobenzoyl-G-actin (MBS-G-actin), which behaves as a functional analogue of native G-actin [Bettache, N., Bertrand, R. & Kassab, R. (1989) Proc. Natl Acad. Sci. USA 86, 6028-6032; Bettache, N., Bertrand, R. & Kassab, R. (1990) Biochemistry 29, 9085-9091) has been employed to probe the solution interaction between monomeric actin and smooth muscle caldesmon, using fluorescence measurements, limited proteolysis and covalent cross-linking reactions. MBS-G-actin associates, without polymerization, to turkey gizzard caldesmon, at about 50 mM ionic strength and 25 degrees C, with a high affinity (Kd approximately 0.04 microM) and with a 1:1 stoichiometry. However, the binding strength of the complex including caldesmon and MBS-G-actin cleaved at the subdomain-2 loop with subtilisin decreased fivefold (Kd approximately 0.20 microM). Conversely, caldesmon strongly protected subdomain-2 of MBS-G-actin from tryptic digestion at the susceptible peptide bond at positions 68-69. Furthermore, caldesmon induced the dissociation of native G-actin from its complex with DNase I, as assessed by cosedimentation assays, and increasing concentrations of the latter protein inhibited the MBS-G-actin-caldesmon interaction, suggesting mutual exclusion binding of caldesmon and DNase I to monomeric actin. MBS-G-actin was specifically coupled, via a maleimidobenzoyl group incorporated into its subdomain-2, to caldesmon, producing in high yield a 205-kDa covalent complex consisting of one actin monomer joined to Cys 580 of caldesmon. A similar conjugation process was observed with the complex of caldesmon and polymerized MBS-F-actin. MBS-G-actin could be also cross-linked to caldesmon by 1-ethyl-3[3-(dimethylamino)propyl]carbodiimide, producing a three-band pattern identical to that of F-actin and caldesmon and previously shown to reflect the covalent union between the NH2-terminal segment of actin and the COOH-terminal actin-binding domain of caldesmon. The overall data point to a direct interaction of the latter region with actin subdomain-2 and suggest that during its binding to monomeric or filamentous actin, the caldesmon functional domain spans the entire length of a single actin and closely contacts the bottom of its subdomain-1 as well as the top portion of its subdomain-2.

Interaction of F-actin with synthetic peptides spanning the loop region of human cardiac beta-myosin heavy chain containing Arg403.

The atomic model of the F-actin-myosin subfragment 1 complex (acto-S-1) from skeletal muscle suggests that the transition of the complex from a weakly to a strongly binding state, generating mechanical force during the contractile cycle, may involve the attachment of the upper 50-kDa subdomain of myosin subfragment 1 (S-1) to the interface between subdomains 1 and 3 of actin. For the human cardiac myosin, this putative interaction would take place at the ordered loop including Arg403 of the beta-heavy chain sequence, a residue whose mutation into Gln is known to elicit a severe hypertrophic cardiomyopathy caused by a decrease of the rate of the actomyosin ATPase activity. Moreover, in several nonmuscle myosins the replacement of a Glu residue within the homolog loop by Ser or Thr also results in the reduction of the actomyosin ATPase rate that is alleviated by phosphorylation. As an approach to the characterization of the unknown interaction properties of F-actin with this particular S-1 loop region, we have synthesized four 17-residue peptides corresponding to the sequence Gly398-Gly414 of the human beta-cardiac myosin. Three peptides included Arg403 (GG17) or Gln403 (GG17Q) or Ser409 (GG17S) and the fourth peptide (GG17sc) was a scrambled version of the normal GG17 sequence. Using fluorescence polarization, cosedimentation analyses and photocross-linking, we show that the three former peptides, but not the scrambled sequence, directly associate in solution to F-actin, at a nearly physiological ionic strength, with almost identical affinities (Kd approximately 40 microM). The binding strength of the F-actin-GG17 peptide complex was increased fivefold (Kd = 8 microM) in the presence of subsaturating concentrations of added skeletal S-1 relative to actin, without apparent competition between the peptide and S-1. Each of the three actin-binding peptides inhibited the steady-state actin-activated MgATPase of skeletal S-1 by specifically decreasing about twofold the Vmax of the reaction without changing the actin affinity for the S-1-ATP intermediate. Cosedimentation assays indicated the binding of about 0.65 mol peptide/mol actin under conditions inducing 70% inhibition. Collectively, the data point to a specific and stoichiometric interaction of the peptides with F-actin that uncouples its binding to S-1 from ATP hydrolysis, probably by interfering with the proper attachment of the S-1 loop segment to the interdomain connection of actin.

Construction, expression and unexpected regulatory properties of a tropomyosin mutant with a 31-residue deletion at the C-terminus (exon 9).

The cDNA coding for human skeletal muscle beta-tropomyosin was expressed in Escherichia coli to produce an unacetylated beta-tropomyosin. This cDNA was deleted from the sequence corresponding to the exon 9 and expressed in E. coli to produce an unacetylated beta-tropomyosin mutant lacking the C-terminal residues 254-284. The main structural and functional properties of the two isolated proteins, designated tropomyosin-1 and des-(254-284)-tropomyosin, respectively, were characterized in comparison with those of the genuine rabbit skeletal muscle alpha beta-tropomyosin. The folding and thermal stability of the three tropomyosins were indistinguishable. Tropomyosin-1, but not des-(254-284)-tropomyosin, was polymerized in the presence of troponin and did bind to actin in the presence of the troponin complex. Despite its weak binding to actin, des-(254-284)-tropomyosin displayed a regulatory function in the presence of troponin with a marked activation of the actomyosin subfragment-1 ATPase in the presence of Ca2+ and low concentrations of subfragment-1. The data were interpreted in the light of the allosteric models of regulation and suggest the involvement of the sequence coded by exon 9 in the stabilization by tropomyosin of the off state of the thin filament.

Characterization of the carboxyl-terminal 10-kDa cyanogen bromide fragment of caldesmon as an actin-calmodulin-binding region.

A pair of 10-kDa peptides, designated CB-a and CB-b, was isolated by calmodulin-Sepharose chromatography from a total CNBr digest of turkey gizzard caldesmon. CB-a encompasses the COOH-terminal segment of residues 659-756, according to the sequence of adult chicken gizzard caldesmon (Bryan, J., Imai, M., Lee, R., Moore, P., Cook, R.G., and Lin, W.G. (1989) J. Biol. Chem. 264, 13873-13879), whereas CB-b comprises the same structure but was a few amino acids shorter at its COOH terminus. Both peptides cosedimented with F-actin, and their binding was increased by smooth muscle tropomyosin. The Kd values were 1.3 and 0.5 microM, in the absence and presence of tropomyosin, respectively, with a maximum binding capacity of 6.9 actins/mol of peptides. The CB-a/CB-b fragments inhibited, in a tropomyosin-sensitive and Ca2(+)-calmodulin-dependent manner, the skeletal actomyosin subfragment 1 ATPase activity to a level close but not identical to that observed for the parent caldesmon. Ca2(+)-calmodulin was selectively cross-linked to either caldesmon or the CNBr peptides with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide producing 1:1 covalent complexes that were retained neither by phenyl-Sepharose nor by immobilized calmodulin. Moreover, the cross-linked caldesmon bound weakly to F-actin and did not inhibit the actomyosin subfragment 1 ATPase in the absence of Ca2+. The results suggest that the CB-a/CB-b peptide region contains major regulatory determinants of caldesmon.

Cross-linking of smooth muscle caldesmon to the NH2-terminal region of skeletal F-actin.

The cross-linking of the F-actin-caldesmon complex with 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide in the presence of N-hydroxysuccinimide generated four major adducts which were identified on polyacrylamide gels. By cross-linking 3H-actin to 14C-caldesmon, these were found to represent 1:1 cross-linked complexes of actin and caldesmon displaying different electrophoretic mobilities. Tropomyosin did not noticeably affect the cross-linking process. The same four fluorescent species resulting from the cross-linking of caldesmon to F-actin labeled with N-[7-(dimethylamino)-4-methyl-3-coumarinyl]maleimide were subjected separately to partial cleavages with hydroxylamine or cyanogen bromide. These treatments yielded fluorescent 41- and 37-kDa fragments, respectively, from each cross-linked entity indicating unambiguously that caldesmon was cross-linked only to the NH2-terminal actin stretch of residues 1-12. This region is also known to serve for the carbodiimide-mediated cross-linking of the myosin subfragment-1 heavy chain (Sutoh, K. (1982) Biochemistry 21, 3654-3661). A covalent caldesmon-F-actin conjugate containing a protein molar ratio close to 1:19 was isolated following dissociation of uncross-linked caldesmon. It showed a low level of activation of the ATPase activity of skeletal myosin subfragment-1, and the binding of Ca2(+)-calmodulin to the derivative did not cause the reversal of the ATPase inhibition. In contrast, the reversible binding of caldesmon to F-actin cross-linked to myosin subfragment-1 did not inhibit the accelerated ATPase of the complex. The overall data point to the dual involvement of the actin's NH2 terminus in the inhibitory binding of caldesmon and in actomyosin interactions in the presence of ATP.

Isolation, characterization and immunocytochemical localization of caldesmon-like protein from molluscan striated muscle.

A 140-kDa polypeptide present in the striated muscle of Pecten maximus and Sepia officinalis was purified to homogeneity and its main properties were investigated using biochemical and cytochemical approaches. The protein was found to be similar to chicken gizzard caldesmon. It is a heat-stable protein. It cross-reacts immunologically with anti-(gizzard caldesmon) antibody, binds to calmodulin-Sepharose in a Ca2+-dependent manner, cosediments with F-actin filaments and acts in the absence and presence of tropomyosin as a potent inhibitor of rabbit skeletal actomyosin Mg2+-ATPase. The immunocytochemistry of ultrathin sections revealed, at the light microscopy resolution level, that caldesmon-like protein is present in all types of muscles hitherto examined from invertebrates and vertebrates. However, according to the distribution and the intensity of the fluorescent reaction, we concluded that, under our experimental conditions, caldesmon is not homogeneously distributed and not located in the myofibrillar bands of striated muscles but rather in the sarcoplasmic elements, at the periphery of the fibres.

PCP and analogs prevent the proliferative response of T lymphocytes by lowering IL2 production. An effect related to the blockade of mitogen-triggered enhancement of free cytosolic calcium concentration.

The psychotomimetic drug PCP displays a vast array of known pharmacological effects, among them its capacity to affect cation transport in nervous and myocardiac tissues. Since increased movements of cations are essential for the immune responses, it has been mentioned that PCP could also depress immune functions by this mechanism. In order to check this hypothesis, we have investigated the effects of PCP and of many other structural derivatives on the blastogenic response of murine or human T lymphocytes. We find that all the drugs block an early event of T lymphocyte activation and prevent their further proliferation; conversely they do not affect primed lymphocytes. The compounds, which do not inhibit interleukin-1 (IL-1) production in stimulated macrophages, lower interleukin-2 (IL-2) synthesis in activated T helper cells. This negative action appears to be related to the inhibition of the rise of free cytosolic calcium concentration [Ca2+]i observed soon after the T receptor triggering and which is an essential message for IL-2 production. The lymphocyte membrane depolarization induced by the drugs could explain the blockade of the lectin-induced [Ca2+]i changes. The study of the structure-activity relationship shows that the PCP analogs which possess a quasi-rigid conformational structure express an inhibitory capacity of T lymphocyte proliferation higher than that of PCP (200 times for some products). Since these compounds interact poorly with the CNS tissues and have few behavioral effects, we suggest that PCP exerts its negative action on lymphocytes on cell components different from its receptor(s) in the CNS.