Crisponi syndrome is caused by mutations in the CRLF1 gene and is allelic to cold-induced sweating syndrome type 1

Crisponi syndrome is a severe autosomal recessive condition that is phenotypically characterized by abnormal, paroxysmal muscular contractions resembling neonatal tetanus, large face, broad nose, anteverted nares, camptodactyly, hyperthermia, and sudden death in most cases. We performed homozygosity mapping in five Sardinian and three Turkish families with Crisponi syndrome, using high-density single-nucleotide polymorphism arrays, and identified a critical region on chromosome 19p12-13.1. The most prominent candidate gene was CRLF1, recently found to be involved in the pathogenesis of cold-induced sweating syndrome type 1 (CISS1). CISS1 belongs to a group of conditions with overlapping phenotypes, also including cold-induced sweating syndrome type 2 and Stuve-Wiedemann syndrome. All these syndromes are caused by mutations of genes of the ciliary neurotrophic factor (CNTF)-receptor pathway. Here, we describe the identification of four different CRLF1 mutations in eight different Crisponi-affected families, including a missense mutation, a single-nucleotide insertion, and a nonsense and an insertion/deletion (indel) mutation, all segregating with the disease trait in the families. Comparison of the mutation spectra of Crisponi syndrome and CISS1 suggests that neither the type nor the location of the CRLF1 mutations points to a phenotype/genotype correlation that would account for the most severe phenotype in Crisponi syndrome. Other, still-unknown molecular factors may be responsible for the variable phenotypic expression of the CRLF1 mutations. We suggest that the syndromes can comprise a family of "CNTF-receptor-related disorders," of which Crisponi syndrome would be the newest member and allelic to CISS1.     

Electromagnetic fields produced by GSM cellular phones and heart rate variability

In this study, 26 healthy young volunteers were submitted to 900 MHz (2 W) GSM cellular phone exposure and to sham exposure in separate sessions. The study was designed to assess cardiac regulatory mechanism in different autonomic nervous system (ANS) states during exposure to low-intensity EMF. Rest-to-stand protocol was applied to evaluate ANS in quiet condition (rest, vagal prevalence) and after a sympathetic activation (stand). The procedure is conducted twice in a double-blind design: once with a genuine EMF exposure and once with a sham exposure (at least 24 h apart). During each session three-leads electrocardiograms were recorded and RR series extracted off-line. Time domain and frequency domain HRV parameters were calculated in every phase of the protocol and during different exposures. The analysis of the data show there was no statistically significant effect due to EMF exposure both on main (i.e., RR mean) and most of the other HRV parameters. A weak interaction between some HRV parameters (i.e., SDNN, TINN, and triangular index in time domain and LF power in frequency domain analysis) and RF exposure was observed and this effect seems to be gathered around the sympathetic response to stand.     

Programmed cell death and stem cell differentiation are responsible for midgut replacement in <Emphasis Type="Italic">Heliothis virescens</Emphasis> during prepupal instar

We have analyzed midgut development during the fifth larval instar in the tobacco budworm Heliothis virescens. In prepupae, the midgut formed during larval instars undergoes a complete renewal process. This drastic remodeling of the alimentary canal involves the destruction of the old cells by programmed cell-death mechanisms (autophagy and apoptosis). Massive proliferation and differentiation of regenerative stem cells take place at the end of the fifth instar and give rise to a new fully functioning epithelium that is capable of digesting and absorbing nutrients and that is maintained throughout the subsequent pupal stage. Midgut replacement in H. virescens is achieved by a balance between this active proliferation process and cell-death mechanisms and is different from similar processes characterized in other insects. This work was supported by FAR 2006 (University of Insubria) to G.T., by a MIUR-FIRB-COFIN grant (no. RBNE01YXA8/2004077251), and by the Centro Grandi Attrezzature (University of Insubria).     

Synthesis and biological evaluation of new conformationally biased integrin ligands based on a tetrahydroazoninone scaffold

The synthesis of new conformationally biased cyclic pentapeptides, incorporating the RGD sequence, and built around a tetrahydroazoninone scaffold, is reported. They exhibit interesting activity towards integrin alphaVbeta3 and a remarkable selectivity in comparison with integrin alphaVbeta5.     

Subcellular localization of APE1/Ref-1 in human hepatocellular carcinoma: possible prognostic significance

APE1/Ref-1, normally localized in the nucleus, is a regulator of the cellular response to oxidative stress. Cytoplasmic localization has been observed in several tumors and correlates with a poor prognosis. Because no data are available on liver tumors, we investigated APE1/Ref-1 subcellular localization and its correlation with survival in 47 consecutive patients undergoing hepatocellular carcinoma (HCC) resection. APE1/Ref-1 expression was determined by immunohistochemistry in HCC and surrounding liver cirrhosis (SLC) and compared with normal liver tissue. Survival probability was evaluated using Kaplan-Meier curves (log-rank test) and Cox regression. Cytoplasmic expression of APE1/Ref-1 was significantly higher in HCC than in SLC (P = 0.00001); normal liver showed only nuclear reactivity. Patients with poorly differentiated HCC showed a cytoplasmic expression three times higher than those with well-differentiated HCC (P = 0.03). Cytoplasmic localization was associated with a median survival time shorter than those with negative cytoplasmic reactivity (0.44 compared with 1.64 years, P = 0.003), and multivariable analysis confirmed that cytoplasmic APE1/Ref-1 localization is a predictor of survival. Cytoplasmic expression of APE1/Ref-1 is increased in HCC and is associated with a lower degree of differentiation and a shorter survival time, pointing to the use of the cytoplasmic localization of APE1/Ref-1 as a prognostic marker for HCC.     

Ectopic expression of RNF168 and 53BP1 increases mutagenic but not physiological non-homologous end joining

DNA double strand breaks (DSBs) formed during S phase are preferentially repaired by homologous recombination (HR), whereas G₁ DSBs, such as those occurring during immunoglobulin class switch recombination (CSR), are repaired by non-homologous end joining (NHEJ). The DNA damage response proteins 53BP1 and BRCA1 regulate the balance between NHEJ and HR. 53BP1 promotes CSR in part by mediating synapsis of distal DNA ends, and in addition, inhibits 5’ end resection. BRCA1 antagonizes 53BP1 dependent DNA end-blocking activity during S phase, which would otherwise promote mutagenic NHEJ and genome instability. Recently, it was shown that supra-physiological levels of the E3 ubiquitin ligase RNF168 results in the hyper-accumulation of 53BP1/BRCA1 which accelerates DSB repair. Here, we ask whether increased expression of RNF168 or 53BP1 impacts physiological versus mutagenic NHEJ. We find that the anti-resection activities of 53BP1 are rate-limiting for mutagenic NHEJ but not for physiological CSR. As heterogeneity in the expression of RNF168 and 53BP1 is found in human tumors, our results suggest that deregulation of the RNF168/53BP1 pathway could alter the chemosensitivity of BRCA1 deficient tumors.     

Constitutive presence of antibiotic resistance genes within the bacterial community of a large subalpine lake

The fate of antibiotic resistance genes (ARGs) in environmental microbial communities is of primary concern as prodromal of a potential transfer to pathogenic bacteria. Although of diverse origin, the persistence of ARGs in aquatic environments is highly influenced by anthropic activities, allowing potential control actions in well‐studied environments. However, knowledge of abundance and space–time distribution of ARGs in ecosystems is still scarce. Using quantitative real‐time PCR, we investigated the presence and the abundance of twelve ARGs (against tetracyclines, β‐lactams, aminoglycosides, quinolones and sulphonamides) at different sampling sites, depths and seasons, in Lake Maggiore, a large subalpine lake, and in the area of its watershed. We then evaluated the correlation between each ARG and a number of ecological parameters in the water column in the deepest part of the lake. Our results suggest the constitutive presence of at least four ARGs within the bacterial community with a high proportion of bacteria potentially resistant to tetracyclines and sulphonamides. The presence of these ARGs was independent of the total bacterial density and temperature. The dynamics of tet(A) and sulII genes were, however, positively correlated with dissolved oxygen and negatively to chlorophyll a, suggesting that the resistant microbes inhabit specific niches. These observations indicate that the lake is a reservoir of antibiotic resistances, highlighting the need of a deeper understanding of the sources of ARGs and the factors allowing their persistence in waters.     

Eya1 controls cell polarity, spindle orientation, cell fate and Notch signaling in distal embryonic lung epithelium

Cell polarity, mitotic spindle orientation and asymmetric division play a crucial role in the self-renewal/differentiation of epithelial cells, yet little is known about these processes and the molecular programs that control them in embryonic lung distal epithelium. Herein, we provide the first evidence that embryonic lung distal epithelium is polarized with characteristic perpendicular cell divisions. Consistent with these findings, spindle orientation-regulatory proteins Insc, LGN (Gpsm2) and NuMA, and the cell fate determinant Numb are asymmetrically localized in embryonic lung distal epithelium. Interfering with the function of these proteins in vitro randomizes spindle orientation and changes cell fate. We further show that Eya1 protein regulates cell polarity, spindle orientation and the localization of Numb, which inhibits Notch signaling. Hence, Eya1 promotes both perpendicular division as well as Numb asymmetric segregation to one daughter in mitotic distal lung epithelium, probably by controlling aPKCζ phosphorylation. Thus, epithelial cell polarity and mitotic spindle orientation are defective after interfering with Eya1 function in vivo or in vitro. In addition, in Eya1(-/-) lungs, perpendicular division is not maintained and Numb is segregated to both daughter cells in mitotic epithelial cells, leading to inactivation of Notch signaling. As Notch signaling promotes progenitor cell identity at the expense of differentiated cell phenotypes, we test whether genetic activation of Notch could rescue the Eya1(-/-) lung phenotype, which is characterized by loss of epithelial progenitors, increased epithelial differentiation but reduced branching. Indeed, genetic activation of Notch partially rescues Eya1(-/-) lung epithelial defects. These findings uncover novel functions for Eya1 as a crucial regulator of the complex behavior of distal embryonic lung epithelium.