G-CSF suppresses allergic pulmonary inflammation, downmodulating cytokine, chemokine and eosinophil production.

AIMS: Granulocyte Colony-Stimulating Factor (G-CSF), which mobilizes hemopoietic stem cells (HSC), is believed to protect HSC graft recipients from graft-versus-host disease by enhancing Th2 cytokine secretion. Accordingly, G-CSF should aggravate Th2-dependent allergic pulmonary inflammation and the associated eosinophilia. We evaluated the effects of G-CSF in a model of allergic pulmonary inflammation. MAIN METHODS: Allergic pulmonary inflammation was induced by repeated aerosol allergen challenge in ovalbumin-sensitized C57BL/6J mice. The effects of allergen challenge and of G-CSF pretreatment were evaluated by monitoring: a) eosinophilia and cytokine/chemokine content of bronchoalveolar lavage fluid, pulmonary interstitium, and blood; b) changes in airway resistance; and c) changes in bone-marrow eosinophil production. KEY FINDINGS: Contrary to expectations, G-CSF pretreatment neither induced nor enhanced allergic pulmonary inflammation. Instead, G-CSF: a) suppressed accumulation of infiltrating eosinophils in bronchoalveolar, peribronchial and perivascular spaces of challenged lungs; and b) prevented ovalbumin challenge-induced rises in airway resistance. G-CSF had multiple regulatory effects on cytokine and chemokine production: in bronchoalveolar lavage fluid, levels of IL-1 and IL-12 (p40), eotaxin and MIP-1a were decreased; in plasma, KC, a neutrophil chemoattractant, was increased, while IL-5 was decreased and eotaxin was unaffected. In bone-marrow, G-CSF: a) prevented the increase in bone-marrow eosinophil production induced by ovalbumin challenge of sensitized mice; and b) selectively stimulated neutrophil colony formation. SIGNIFICANCE: These observations challenge the view that G-CSF deviates cytokine production towards a Th2 profile in vivo, and suggest that this neutrophil-selective hemopoietin affects eosinophilic inflammation by a combination of effects on lung cytokine production and bone-marrow hemopoiesis.

[Axonal growth inhibition by chondroitin sulfate proteoglycans in the central nervous system]. / Inhibición del crecimiento axonal por proteoglicanos de condroitin sulfato en el sistema nervioso central.

Chondroitin sulphate proteoglycans (CSPG) are components of the extracellular matrix, consisting of peptides chemically attached covalently to chains of glycosaminoglycans. There are 4 families of CSPG including lecticans, which are found mainly in the central nervous system (CNS) of vertebrates. In vitro studies have shown a negative effect of these proteoglycans on axonal growth, mediated by depolymerization of actin filaments in the neuronal cytoskeleton. In some neurodegenerative diseases, and especially after traumatic injuries of adult CNS, there are increased levels of CSPG expression. Axonal growth inhibition by CSPG has been observed also in vivo, and therefore a strategy aimed to counteract the inhibition of axonal growth might lead to new therapies designed to restore neural circuits. There is compelling in vivo evidence that CSPG degradation by Chondroitinase ABC allows both axonal growth and functional recovery in models of injury in the mammalian CNS. These data suggest that manipulation of the response to damage could result in effective ways to promote recovery of nerve functions in neurological disorders that affect humans, such as spinal cord lesions or Parkinson disease.

Immune complexes inhibit differentiation, maturation, and function of human monocyte-derived dendritic cells.

The interaction between immune complexes (IC) and the receptors for the Fc portion of IgG (FcgammaRs) triggers regulatory and effector functions in the immune system. In this study, we investigated the effects of IC on differentiation, maturation, and functions of human monocyte-derived dendritic cells (DC). When IC were added on day 0, DC generated on day 6 (IC-DC) showed lower levels of CD1a and increased expression of CD14, MHC class II, and the macrophage marker CD68, as compared with normally differentiated DC. The use of specific blocking FcgammaR mAbs indicated that the effect of IC was exerted mainly through their interaction with FcgammaRI and to a lesser extend with FcgammaRII. Immature IC-DC also expressed higher levels of CD83, CD86, and CD40 and the expression of these maturation markers was not further regulated by LPS. The apparent lack of maturation following TLR stimulation was associated with a decreased production of IL-12, normal secretion of IL-10 and CCL22, and increased production of CXCL8 and CCL2. IC-DC displayed low endocytic activity and a reduced ability to induce allogeneic T cell proliferation both at basal and LPS-stimulated conditions. Altogether, these data reveal that IC strongly affect DC differentiation and maturation. Skewing of DC function from Ag presentation to a proinflammatory phenotype by IC resembles the state of activation observed in DC obtained from patients with chronic inflammatory autoimmune disorders, such as systemic lupus erythematosus disease and arthritis. Therefore, the altered maturation of DC induced by IC may be involved in the pathogenesis of autoimmune diseases.

BAFF and LPS cooperate to induce B cells to become susceptible to CD95/Fas-mediated cell death.

Microorganisms with pathogen-associated molecular patterns (PAMP) activate B cells directly by binding to TLR and also indirectly by inducing APC to release cytokines such as BAFF that promote B cell survival. We found that murine B cells activated concomitantly with LPS (TLR-4 ligand) and BAFF are protected from spontaneous apoptosis, but are more susceptible to Fas/CD95-mediated cell death. This increased susceptibility to Fas-induced apoptosis is associated with a dramatic coordinated up-regulation of Fas/CD95 and IRF-4 expression through a mechanism mediated, at least in part, by inhibition of the MEK/ERK pathway. Up-regulation of Fas/CD95 by BAFF is restricted to B cells activated through TLR-4, but not through TLR-9, BCR or CD40. TLR ligands differ in the BAFF family receptors (R) they induce on B cells: BAFF-R is increased by the TLR4 ligand, LPS, but not by the TLR9 ligand, CpG-containing oligodeoxynucleotides, which, in contrast, strongly up-regulates transmembrane activator and CAML interactor (TACI). This suggests the up-regulation of Fas by BAFF is mediated by BAFF-R and not by TACI. Consistently, APRIL, which binds to TACI and B cell maturation antigen but not BAFF-R, did not enhance Fas expression on LPS-activated B cells. Increased susceptibility to Fas-mediated killing of B cells activated with LPS and BAFF may be a fail-safe mechanism to avoid overexpansion of nonspecific or autoreactive B cells.

Temporal expression pattern of myostatin transcripts during chicken embryogenesis

No presente estudo, estimou-se a abundância dos transcritos da miostatina foi estimada durante a embriogênese de galinha por análises de RT-PCR competitiva. Níveis basais de mRNA desse gene foram detectados até o estádio HH15, enquanto acúmulos significativos nesses níveis foram observados apenas no estádio HH24, seguido por redução na abundância desses transcritos a partir do estádio HH26. Tais descobertas preliminares proporcionam informações relevantes sobre a ativação do fator de crescimento miostatina durante o desenvolvimento in ovo de aves.

Temporal expression pattern of myostatin transcripts during chicken embryogenesis / Padrão de expressão temporal de transcritos de miostatina durante a embriogênese da galinha

No presente estudo, estimou-se a abundância dos transcritos da miostatina foi estimada durante a embriogênese de galinha por análises de RT-PCR competitiva. Níveis basais de mRNA desse gene foram detectados até o estádio HH15, enquanto acúmulos significativos nesses níveis foram observados apenas no estádio HH24, seguido por redução na abundância desses transcritos a partir do estádio HH26. Tais descobertas preliminares proporcionam informações relevantes sobre a ativação do fator de crescimento miostatina durante o desenvolvimento in ovo de aves.(AU)

Two different late embryogenesis abundant proteins from Arabidopsis thaliana contain specific domains that inhibit Escherichia coli growth.

Late embryogenesis abundant (LEA) proteins constitute a set of proteins widespread in the plant kingdom that show common physicochemical properties such as high hydrophilicity and high content of small amino acid residues such as glycine, alanine, and serine. Typically, these proteins accumulate in response to water deficit conditions imposed by the environment or during plant normal development. In this work, we show that the over-expression in Escherichia coli of proteins of the LEA 2 and the LEA 4 families from Arabidopsis thaliana leads to inhibition of bacterial growth and that this effect is dependent on discrete regions of the proteins. Our data indicate that their antimicrobial effect is achieved through their interaction with intracellular targets. The relevance of the cationic nature and the predicted structural organization of particular protein domains in this detrimental effect on the bacteria growth process is discussed.

Role of TLR in B cell development: signaling through TLR4 promotes B cell maturation and is inhibited by TLR2.

The role of TLR4 in mature B cell activation is well characterized. However, little is known about TLR4 role in B cell development. Here, we analyzed the effects of TLR4 and TLR2 agonists on B cell development using an in vitro model of B cell maturation. Highly purified B220(+)IgM(-) B cell precursors from normal C57BL/6 mouse were cultured for 72 h, and B cell maturation in the presence of the TLR agonists was evaluated by expression of IgM, IgD, CD23, and AA4. The addition of LPS or lipid A resulted in a marked increase in the percentage of CD23(+) B cells, while Pam3Cys had no effect alone, but inhibited the increase of CD23(+) B cell population induced by lipid A or LPS. The TLR4-induced expression of CD23 is not accompanied by full activation of the lymphocyte, as suggested by the absence of activation Ag CD69. Experiments with TLR2-knockout mice confirmed that the inhibitory effects of Pam3Cys depend on the expression of TLR2. We studied the effects of TLR-agonists on early steps of B cell differentiation by analyzing IL-7 responsiveness and phenotype of early B cell precursors: we found that both lipid A and Pam3Cys impaired IL-7-dependent proliferation; however, while lipid A up-regulates B220 surface marker, consistent with a more mature phenotype of the IgM(-) precursors, Pam3Cys keeps the precursors on a more immature stage. Taken together, our results suggest that TLR4 signaling favors B lymphocyte maturation, whereas TLR2 arrests/retards that process, ascribing new roles for TLRs in B cell physiology.

Arginine vasopressin inhibition of cyclin D1 gene expression blocks the cell cycle and cell proliferation in the mouse Y1 adrenocortical tumor cell line.

Arginine vasopressin (AVP) is a nonapeptide long known as an endocrine and paracrine regulator of important systemic functions, namely, vasoconstriction, gluconeogenesis, corticosteroidogenesis, and excretion of water and urea. Here we report, for the first time, that AVP specifically inhibits expression of the cyclin D1 gene, leading to cell cycle blockage and halting cell proliferation. In G0/G1-arrested mouse Y1 adrenocortical tumor cells, maintained in serum-free medium (SFM), AVP mimics FGF2, promoting rapid ERK1/2 activation (5 min) followed by c-Fos protein induction (2 h). PKC inhibitor Go6983 and PI3K inhibitors wortmannin and LY294002 all inhibit ERK1/2 activation by AVP, but not by FGF2. Thus, AVP and FGF2 concur to activate ERK1/2 by different regulatory pathways. However, AVP is not a mitogenic factor for Y1 cells. On the contrary, AVP strongly antagonizes FGF2 late induction (2-5 h) of the cyclin D1 gene, down-regulating both cyclin D1 mRNA and protein. AVP inhibition of cyclin D1 expression is sufficient to block G1 phase progression and cell entry into the S phase, monitored by BrdU nuclear labeling. In addition, AVP completely inhibits proliferation of Y1 cells in 10% fetal calf serum (10% FCS) medium. On the other hand, ectopic expression of the cyclin D1 protein renders Y1 cells resistant to AVP for both entry into the S phase in SFM and continuous proliferation in 10% FCS medium. In conclusion, inhibition of cyclin D1 expression by AVP is an efficient mechanism of cell cycle blockage and consequent proliferation inhibition in Y1 adrenocortical cells.

Assessment of seminiferous tubule function (anti-müllerian hormone).

Anti-müllerian hormone (AMH) is specifically produced by Sertoli cells in the male. The testes express a high level of AMH from early fetal life, driven by the transcription factors SOX9, SF1, WT1 and GATA4, until puberty, when AMH is downregulated by testosterone and meiosis. When androgen negative effect is absent, follicle-stimulating hormone increases the secretion of AMH. Serum AMH determination is useful in the evaluation of children with non-palpable gonads, with or without ambiguous genitalia. It signals the existence of functional testicular tissue and allows a distinction to be made between gonadal dysgenesis and dissociated tubular-interstitial dysfunction. Serum AMH is a useful marker in the follow-up of male patients with precocious puberty or hypogonadotrophic hypogonadism, as well as of patients with sex cord stromal tumours of the gonads. Finally, AMH determination on the seminal plasma of men with non-obstructive azoospermia may be used as a marker of the existence of testicular spermatozoa when intracytoplasmic sperm injection is considered.

Inhibición del crecimiento bacteriano "in vitro" producido por un medio de cementación temporal experimental / In vitro bacterial growth inhibition produced by and experimental temporary luting cement

Se demostró la actividad antibacteriana "in vitro" de un medio de cementación temporal experimental, en base a óxido de zinc eugenol e hidróxido de calcio, frente a una cepa de S. mutans y frente a una de L. acidophillus, ambos microorganismos indicados como algunos de los principales en la producción de la caries dentaria. El medio de cementación experimental presentó inhibición del desarrollo bacteriano "in vitro", tanto frente al Streptococcus mutans como frente al Lactobacillus acidophillus

Inhibitory activity of soluble IL-2R in sera, ascites and culture supernatants from murine leukaemic cells.

The effect of sera from mice bearing a T cell lymphoid leukaemia (LB) and the supernatants from short term cultures of the tumour cells were studied on cell proliferation using syngeneic and allogeneic normal and tumour cells. An inhibitory activity was demonstrated in 24-48 h supernatants of LB cells in culture and disappeared after 4 days of culture. Inhibitory activity was cytostatic but not cytotoxic and was non-specific since it inhibited the growth of both syngeneic and allogeneic normal and tumour cells. Such activity was found in the 10(5)-1.3 x 10(5) M(r) serum fraction after a Sephacryl S200 chromatography. Though sensitive to protease, trypsin or neuraminidase treatment, which indicated its glycoprotein nature, it remained stable after heating or freezing-thawing cycles as well as after alkaline, acid or hyaluronidase treatment. Addition of exogenous IL-2 abrogated inhibitory activity. ELISA showed the presence of soluble IL-2R both in LB conditioned medium and in above serum fraction. It is demonstrated that the inhibitory factor, soluble IL-2R, is produced by LB leukaemia cells, then secreted into blood and ascitic fluid or released into culture supernatants. Soluble IL-2R exerts inhibitory activity blocking cell proliferation and modulating immune response by binding to free IL-2.

Regeneraçäo hepática: algumas definiçöes num universo de incertezas / Liver regeneration: some definitions in an universe of doubts

No presente estudo, os autores elaboraram uma extensa abordagem acêrca da regeneraçäo hepática. Aspectos básicos, tais como cinética da resposta regenerativa, fases do processo replicativo e fatores que interferem na magnitude da síntese hepatocelular de DNA foram considerados. Considerou-se ainda as principais alteraçöes na expressäo gênica relacionadas à regeneraçäo hepática e, por fim, um minucioso relato dos principais fatores de crescimento hepático, com suas interaçöes e possíveis mecanismos de açäo

Estudo in vitro da inibiçäo do crescimento de bactérias pelo hidróxido de magnésio / In vitro study of magnesium hydroxide inhibition of bacterial growth

Estudou-se a açäo "in vitro" do hidróxido de magnésio como inibidor do crescimento de algumas bactérias que säo comumente encontradas em feridas operatórias infectadas. Utilizou-se culturas de Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pyogenes e Streptococcus faecalis, que foram colocadas em tubos com diferentes diluiçöes de suspensäo de Mg (OH)2 a 8%, a saber: 1, 1/2, 1/4, 1/8 e 1/16. Esses tubos foram incubados por 24 horas e entäo deles retirou-se amostras que foram colocadas em placas de ágar-sangue com e sem filtraçäo em membraa Millipore e em meio de cultura BHI. Os resultados demonstraram que a suspensäo de Mg (OH)2 a 8% até a diluiçäo de 1/4 foi faecalis. Os dados encontrados neste estudo abrem novas perspectivas de pesquisa utilizando o Mg (OH)2, seja em laboratório seja em atividade clínica no tratamento de feridas operatórias infectadas ou em outros ferimentos supurativos