Integrin binding site within the gC1q domain orchestrates EMILIN-1-induced lymphangiogenesis.

Lymphatic vessels (LVs) play a pivotal role in the control of tissue homeostasis and also have emerged as important regulators of immunity, inflammation and tumor metastasis. EMILIN-1 is the first ECM protein identified as a structural modulator of the growth and maintenance of LV; accordingly, Emilin1-/- mice display lymphatic morphological alterations leading to functional defects as mild lymphedema, leakage and compromised lymph drainage. Many EMILIN-1 functions are exerted by the binding of its gC1q domain with the E933 residue of α4 and α9β1 integrins. To investigate the specific regulatory role of this domain on lymphangiogenesis, we generated a transgenic mouse model expressing an E933A-mutated EMILIN-1 (E1-E933A), unable to interact with α4 or α9 integrin. The mutant resulted in abnormal LV architecture with dense, tortuous and irregular networks; moreover, the number of anchoring filaments was reduced and collector valves had aberrant narrowed structures. E933A mutation also affected lymphatic function in lymphangiography assays and made the transgenic mice more prone to lymph node metastases. The finding that the gC1q/integrin interaction is crucial for a correct lymphangiogenesis response was confirmed and reinforced by functional in vitro tubulogenesis assays. In addition, ex vivo thoracic-duct ring assays revealed that E1-E933A-derived lymphatic endothelial cells had a severe reduction in sprouting capacity and were unable to organize into capillary-like structures. All these data provide evidence that the novel "regulatory structural" role of EMILIN-1 in the lymphangiogenic process is played by the integrin binding site within its gC1q domain

Chemerin expression marks early psoriatic skin lesions and correlates with plasmacytoid dendritic cell recruitment

Psoriasis is a type I interferon-driven T cell–mediated disease characterized by the recruitment of plasmacytoid dendritic cells (pDC) into the skin. The molecules involved in pDC accumulation in psoriasis lesions are unknown. Chemerin is the only inflammatory chemotactic factor that is directly active on human blood pDC in vitro. The aim of this study was to evaluate the role of the chemerin/ChemR23 axis in the recruitment of pDC in psoriasis skin. Prepsoriatic skin adjacent to active lesions and early lesions were characterized by a strong expression of chemerin in the dermis and by the presence of CD15+ neutrophils and CD123+/BDCA-2+/ChemR23+ pDC. Conversely, skin from chronic plaques showed low chemerin expression, segregation of neutrophils to epidermal microabscesses, and few pDC in the dermis. Chemerin expression was localized mainly in fibroblasts, mast cells, and endothelial cells. Fibroblasts cultured from skin of psoriatic lesions expressed higher levels of chemerin messenger RNA and protein than fibroblasts from uninvolved psoriatic skin or healthy donors and promoted pDC migration in vitro in a chemerin-dependent manner. Therefore, chemerin expression specifically marks the early phases of evolving skin psoriatic lesions and is temporally strictly associated with pDC. These results support a role for the chemerin/ChemR23 axis in the early phases of psoriasis development

Distal motor neuropathy associated with novel EMILIN1 mutation

Abstract Elastin microfibril interface-located proteins (EMILINs) are extracellular matrix glycoproteins implicated in elastogenesis and cell proliferation. Recently, a missense mutation in the EMILIN1 gene has been associated with autosomal dominant connective tissue disorder and motor-sensory neuropathy in a single family. We identified by whole exome sequencing a novel heterozygous EMILIN1 mutation c.748C>T [p.R250C] located in the coiled coil forming region of the protein, in four affected members of an autosomal dominant family presenting a distal motor neuropathy phenotype. In affected patient a sensory nerve biopsy showed slight and unspecific changes in the number and morphology of myelinated fibers. Immunofluorescence study of a motor nerve within a muscle biopsy documented the presence of EMILIN-1 in nerve structures. Skin section and skin derived fibroblasts displayed a reduced extracellular deposition of EMILIN-1 protein with a disorganized network of poorly ramified fibers in comparison with controls. Downregulation of emilin1a in zebrafish displayed developmental delay, locomotion defects, and abnormal axonal arborization from spinal cord motor neurons. The phenotype was complemented by wild-type zebrafish emilin1a, and partially the human wild-type EMILIN1 cRNA, but not by the cRNA harboring the novel c.748C>T [p.R250C]. These data suggest a role of EMILIN-1 in the pathogenesis of diseases affecting the peripheral nervous system

Effetto di due approcci terapeutici sulle lesioni spinali in modelli animali di trauma spinale contusivo

Using a standardized rodent model of contusive spinal cord injury we investigated the effect of intravenous administration of recombinant human erythropoietin (rhEPO) or of adult neural stem cells (NSCs). We sought to determine whether these treatments attenuate the structural damage of the nervous tissue, limiting the evolution of the secondary injury. To this end we applied morphological and cytochemical methods, combined with light, confocal and electron microscopy to study: a) myelin preservation, b) activation of adult oligodendrocyte progenitors identified for the expression of NG2, c) changes in the amount of the chondroitin sulfate proteoglycans, d) ventral horn density of the serotoninergic plexus as marker of descending motor control axons, e) expression of the astrocyte marker aquaporin 4 (AQP4), f) extent of reactive gliosis evaluated by the expression of glial fibrillary acid protein and vimentin. The results showed that: 1) rhEPO administration produces several benefical effects, well correlated with the locomotor recovery, such as reduction of the lesion site, attenuation of astrogliosis, increase of AQP4/NG2 immunoreactivit

Children as Rights Holders

La Convention internationale des droits de l’enfant (CIDE) a été ratifiée par tous les pays reconnus par l’ONU, à l’exception des États-Unis, mais le débat qui a précédé son approbation n’a jamais pris fin. Les freins à la mise en œuvre des droits des enfants demeurent et le paradigme et les stratégies adoptés jusqu’à présent sont mis en question. Dans cet article, nous souhaitons identifier les points d’achoppement de l’application des droits des enfants tels que définis par la CIDE. Ces difficultés sont en grande partie, mais pas exclusivement, imputables à l’hétérogénéité des systèmes juridiques des pays signataires dans un monde globalisé. Particulièrement, l’écart de pouvoir entre les enfants et les adultes change d’une culture à une autre et selon les conditions socio-économiques, notamment au sein des familles. Deux points clés méritent d’être abordés par les études et les recherches sur les droits des enfants. Le premier porte sur la nécessité d’identifier de nouvelles conceptualisations des droits des enfants transformant l’approche descendante en une approche ascendante. Le deuxième questionne la pertinence de l’approche juridique pour aborder les droits des enfants et leur bien-être.Though the 1989 UN Convention on the Rights of the Child was ratified by all states, USA excepted, the intense debate preceding its approval has never ended. Even recently, scholars have emphasized the difficulties in enforcing children’s rights, and are questioning the paradigm and strategies that have been adopted to date. In this article, we attempt to identify the main difficulties in making children’s rights a reality. All these factors are largely, though not exclusively, due to the uneasy coexistence of plural legal orders in a globalized world, where the power gap between children and adults, especially in family relations, changes from culture to culture and according to the different socio-economic conditions. We conclude by highlighting two key points that should be addressed by children’s rights studies and research. First, new conceptualizations of children’s rights that reflect a shift from a top-down to a bottom-up approach are needed. Second, questions should be raised as to whether the legal approach is the most suitable to address children’s rights and well-being

Differential expression of several extracellular matrix molecules in functionally and developmentally distinct regions of rat spinal cord

We have examined the regional distribution of several chondroitin sulfate proteoglycans (neurocan, brevican, versican, aggrecan, phosphacan), of their glycosaminoglycan moieties, and of tenascin-R in the spinal cord of adult rat. The relationships of these molecules with glial and neuronal populations, identified with appropriate markers, were investigated by using multiple fluorescence labeling combined with confocal microscopy. The results showed that the distribution of the examined molecules was similar at all spinal cord levels but displayed area-specific differences along the dorso-ventral axis, delimiting functionally and developmentally distinct areas. In the gray matter, laminae I and II lacked perineuronal nets (PNNs) of extracellular matrix and contained low levels of chondroitin sulfate glycosaminoglycans (CS-GAGs), brevican, and tenascin-R, possibly favoring the maintenance of local neuroplastic properties. Conversely, CS-GAGs, brevican, and phosphacan were abundant, with numerous thick PNNs, in laminae III-VIII and X. Motor neurons (lamina IX) were surrounded by PNNs that contained all molecules investigated but displayed various amounts of CS-GAGs. Double-labeling experiments showed that the presence of PNNs could not be unequivocally related to specific classes of neurons, such as motor neurons or interneurons identified by their expression of calcium-binding proteins (parvalbumin, calbindin, calretinin). However, a good correlation was found between PNNs rich in CS-GAGs and the neuronal expression of the Kv3.1b subunit of the potassium channel, a marker of fast-firing neurons. This observation confirms the correlation between the electrophysiological properties of these neurons and the specific composition of their microenvironment

Local inhibition of elastase reduces EMILIN1 cleavage reactivating lymphatic vessel function in a mouse lymphoedema model

Lymphatic vasculature critically depends on the connections of lymphatic endothelial cells with the extracellular matrix (ECM), which are mediated by anchoring filaments (AFs). The ECM protein EMILIN1 is a component of AFs and is involved in the regulation of lymphatic vessel functions: accordingly, Emilin1(-/-) mice display lymphatic vascular morphological alterations, leading to functional defects such as mild lymphoedema, lymph leakage and compromised lymph drainage. In the present study, using a mouse post-surgical tail lymphoedema model, we show that the acute phase of acquired lymphoedema correlates with EMILIN1 degradation due to neutrophil elastase (NE) released by infiltrating neutrophils. As a consequence, the intercellular junctions of lymphatic endothelial cells are weakened and drainage to regional lymph nodes is severely affected. The local administration of sivelestat, a specific NE inhibitor, prevents EMILIN1 degradation and reduces lymphoedema, restoring a normal lymphatic functionality. The finding that, in human secondary lymphoedema samples, we also detected cleaved EMILIN1 with the typical bands of an NE-dependent pattern of fragmentation establishes a rationale for a powerful strategy that targets NE inhibition. In conclusion, the attempts to block EMILIN1 degradation locally represent the basis for a novel 'ECM' pharmacological approach to assessing new lymphoedema treatments

Differential Expression and Regulation of Toll-Like Receptors (TLR) in Human Leukocytes: Selective Expression of TLR3 in Dendritic Cells

Members of the Toll-like receptor (TLR) family probably play a fundamental role in pathogen recognition and activation of innate immunity, The present study used a systematic approach to analyze how different human leukocyte populations express specific transcripts for the first five characterized TLR family members. TLR1 was expressed in all leukocytes examined, including monocytes, polymorphonuclear leukocytes, T and B cells, and NK cells. In contrast TLR2, TLR4, and TLR5 were expressed in myelomonocytic elements, Exposure to bacterial products, such as LPS or lipoarabinomannan, or to proinflammatory cytokines increased TLR4 expression in monocytes and polymorphonuclear leukocytes, whereas IL-IO blocked this effect, TLR3 was only expressed in human dendritic cells (DC) wherein maturation induced by bacterial products or cytokines was associated with reduced expression. TLR3 mRNA expression was detected by in situ hybridization in DC and lymph nodes. These results demonstrate that TLR1 through TLR5 mRNAs are differentially expressed and regulated in human leukocytes. In particular, expression of TLR3 transcripts is restricted to DC that are the only elements which express the full TLR repertoire. These data suggest that TLR can be classified based on expression pattern as ubiquitous (TLR1), restricted (TLK2, TLR4, and TLR5 in myelomonocytic cells), and specific (TLR3 in DC) molecules