X-linked dominant chondrodysplasia with platyspondyly, distinctive brachydactyly, hydrocephaly, and microphthalmia

We describe a family with an X-linked dominant chondrodysplasia. Four males and six females were affected through four generations. Identification of skeletal abnormalities and hydrocephaly during the pregnancy of three male fetuses led to termination of the pregnancies. A fourth affected male died at 6 days of life. The four patients had chondrodysplasia, hydrocephaly, and facial features with microphthalmia. Radiographs showed severe platyspondyly and various bone abnormalities including a distinctive metaphyseal cupping of the metacarpals, metatarsals, and phalanges. The affected females were less affected and showed small stature, sometimes associated with body asymmetry and mild mental retardation. This condition appears to be a previously unrecognized X-linked dominant chondrodysplasia.     

Functional proteomics mapping of a human signaling pathway

Access to the human genome facilitates extensive functional proteomics studies. Here, we present an integrated approach combining large-scale protein interaction mapping, exploration of the interaction network, and cellular functional assays performed on newly identified proteins involved in a human signaling pathway. As a proof of principle, we studied the Smad signaling system, which is regulated by members of the transforming growth factor beta (TGFbeta) superfamily. We used two-hybrid screening to map Smad signaling protein-protein interactions and to establish a network of 755 interactions, involving 591 proteins, 179 of which were poorly or not annotated. The exploration of such complex interaction databases is improved by the use of PIMRider, a dedicated navigation tool accessible through the Web. The biological meaning of this network is illustrated by the presence of 18 known Smad-associated proteins. Functional assays performed in mammalian cells including siRNA knock-down experiments identified eight novel proteins involved in Smad signaling, thus validating this integrated functional proteomics approach.     

Inactivation of p16 INK4a /CDKN2A gene may be a diagnostic feature of large B cell lymphoma leg type among cutaneous B cell lymphomas

The World Health Organization-European Organization for Research and Treatment of Cancer has individualized three main categories among the primary cutaneous B cell lymphoma (PCBCL): leg-type primary cutaneous large B cell lymphoma (PCLBCL leg type), primary cutaneous follicle center lymphoma (PCFCL), and primary cutaneous marginal zone lymphoma (PCMZL). The genetic features of 21 PCBCL cases (six PCLBCL leg type four PCFCL large cells, seven PCFCL small cells, and four PCMZL) were investigated by comparative genomic hybridization (CGH array). Fluorescent in situ hybridization (FISH) analysis was performed to confirm CGH array data and to detect lymphoma-associated gene rearrangements. p14 ( ARF )/p16 ( INK4a ) CDKN2A gene quantification, methylation analysis, and immunohistochemical detection were also performed. CGH array showed a higher number of recurrent genetic imbalances in PCLBCL leg type (mean 62) than in PCFCL large cells (mean 34). PCFCL small cells and PCMZL exhibited fewer chromosomal alterations (mean 24 and 9). FISH analysis provided concordant results with CGH array data in 97% (98 of 101) assays and demonstrated a t(8;14)(q24;q32) in two of six PCLBCL leg type. Recurrent deletions in 9p21 (p14 ( ARF )/p16 ( INK4a ) CDKN2A) were a constant finding in PCLBCL leg type (six of six). Conversely, PCFCL large cells exhibited recurrent 1p36 deletions (four of four) without deletion in 9p21 (zero of four). The diagnostic and prognostic impact of the p16 ( INK4a ) CDKN2A gene status in PCBCL should therefore be confirmed on a larger series.     

Impairment of intramacrophagic Brucella suis multiplication by human natural killer cells through a contact-dependent mechanism

Brucella spp. are facultative intracellular bacteria that can establish themselves and cause chronic disease in humans and animals. NK cells play a key role in host defense. They are implicated in an early immune response to a variety of pathogens. However, it was shown that they do not control Brucella infection in mice. On the other hand, NK cell activity is impaired in patients with acute brucellosis, and recently it was demonstrated that human NK cells mediate the killing of intramacrophagic Mycobacterium tuberculosis in in vitro infection. Therefore, we have analyzed the behavior of Brucella suis infecting isolated human macrophages in the presence of syngeneic NK cells. We show that (i) NK cells impair the intramacrophagic development of B. suis, a phenomenon enhanced by NK cell activators, such as interleukin-2; (ii) NK cells cultured in the presence of infected macrophages are highly activated and secrete gamma interferon and tumor necrosis factor alpha; (iii) impairment of bacterial multiplication inside infected cells is marginally associated with the cytokines produced during the early phase of macrophage-NK cell cocultures; (iv) direct cell-to-cell contact is required for NK cells to mediate the inhibition of B. suis development; and (v) inhibition of B. suis development results from an induction of NK cell cytotoxicity against infected macrophages. Altogether, these findings show that NK cells could participate early in controlling the intramacrophagic development of B. suis in humans. It seems thus reasonable to hypothesize a role for NK cells in the control of human brucellosis. However, by impairing the activity of these cells in the acute phase of the illness, the pathogen should avoid this control.     

BMP inhibition initiates neural induction via FGF signaling and Zic genes

Neural induction is the process that initiates nervous system development in vertebrates. Two distinct models have been put forward to describe this phenomenon in molecular terms. The default model states that ectoderm cells are fated to become neural in absence of instruction, and do so when bone morphogenetic protein (BMP) signals are abolished. A more recent view implicates a conserved role for FGF signaling that collaborates with BMP inhibition to allow neural fate specification. Using the Xenopus embryo, we obtained evidence that may unite the 2 views. We show that a dominant-negative R-Smad, Smad5-somitabun—unlike the other BMP inhibitors used previously—can trigger conversion of Xenopus epidermis into neural tissue in vivo. However, it does so only if FGF activity is uncompromised. We report that this activity may be encoded by FGF4, as its expression is activated upon BMP inhibition, and its knockdown suppresses endogenous, as well as ectopic, neural induction by Smad5-somitabun. Supporting the importance of FGF instructive activity, we report the isolation of 2 immediate early neural targets, zic3 and foxD5a. Conversely, we found that zic1 can be activated by BMP inhibition in the absence of translation. Finally, Zic1 and Zic3 are required together for definitive neural fate acquisition, both in ectopic and endogenous situations. We propose to merge the previous models into a unique one whereby neural induction is controlled by BMP inhibition, which activates directly, and, via FGF instructive activity, early neural regulators such as Zic genes.     

Neutrophils promote aerogenous spread of lung adenocarcinoma with bronchioloalveolar carcinoma features.

PURPOSE: Adenocarcinoma with bronchioloalveolar carcinoma (BAC) features is a subtype of non-small cell lung cancers characterized by an intense inflammatory reaction composed of macrophages and neutrophils and by a distinct natural history with intrapulmonary spread leading to death due to respiratory failure. We hypothesized that neutrophils could promote aerogenous spread of lung adenocarcinoma with BAC features. EXPERIMENTAL DESIGN: We examined the effect of neutrophils on A549 cell line detachment in vitro and we quantified desquamation of tumor cells on tumor tissue (n = 25) and on matched bronchioloalveolar lavage (n = 17) in vivo in a series of patients with adenocarcinoma with BAC features. RESULTS: Neutrophils induced A549 detachment mediated by signals through cell-to-cell contact. Detached A549 cells were still viable and able to proliferate in vitro. Neutralization studies identified several membrane-bound molecules involved in detachment (i.e., intercellular adhesion molecule-1/lymphocyte function-associated antigen-1, tumor necrosis factor alpha/tumor necrosis factor alpha receptor inhibitor, interleukin-1alpha /interleukin-1alpha receptor, and neutrophil elastase). In tumor tissue, shedding was detected in all samples, with a median shedding score of 42% (range, 4-95%). Micropapillary clusters were detected in 23 of the 25 tumor tissue samples, with a median micropapillary score of 1.40 (range, 0-2.1), and tumor cells were detected in 7 of 17 lavages. The micropapillary score was associated with a high neutrophil count in bronchioloalveolar lavage (P = 0.051). The shedding cell percentage was a significant factor in shorter survival (P = 0.034, univariate Cox analysis). CONCLUSIONS: Tumor shedding is induced by neutrophils. It is a significant factor of shorter survival and may be an important event in adenocarcinoma progression.     

Neutrophils do not contribute to infarction,oxidative stress,and NO synthase activity in severe brain ischemia

Polymorphonuclear leukocytes (PMNs) were reported to contribute to ischemia-reperfusion-induced brain damage. The present work examined whether PMN infiltration is deleterious in a severe model of transient focal cerebral ischemia and in which part PMNs contribute to oxidative stress and nitric oxide (NO) production. A 20-min occlusion of the left middle cerebral artery and both common carotid arteries was performed in rats. Infarction was maximal 24 h after reperfusion, while accumulation of PMNs in infarcted tissue was not significant before 48 h. Moreover, neutropenia induced by vinblastine (0.5 mg/kg iv) significantly decreased by 60-80% PMN infiltration 48 h after reperfusion but did not reduce the infarct volume. Thus PMNs do not contribute to cerebral injury in our model. Furthermore, decreased PMN infiltration modified neither oxidative stress evaluated by glutathione concentrations nor NO synthase activities 48 h after reperfusion. In conclusion, our results suggest that PMNs are not involved in severe cerebral ischemia and that anti-PMN strategies may be inefficient in some pathological conditions.