A New Species of Sand Racer, Psammodromus (Squamata: Lacertidae), from the Western Iberian Peninsula

A new species of lacertid lizard of the genus Psammodromus is described from the Iberian Peninsula. Genetic and recently published phenotypic data support the differentiation of Psammodromus hispanicus into three, and not as previously suggested two, distinct lineages. Age estimates, lineage allopatry, the lack of mitochondrial and nuclear haplotype sharing between lineages, ecological niche divergence, and the current biogeographic distribution, indicated that the three lineages correspond to three independent species. Here, we describe a new species, Psammodromus occidentalis sp. n., which is genetically different from the other sand racers and differentiated by the number of femoral pores, number of throat scales, snout shape, head ratio, green nuptial coloration, and number of supralabial scales below the subocular scale. We also propose to upgrade the two previously recognized subspecies, Psammodromus hispanicus hispanicus Fitzinger, 1826 from central Spain and Psammodromus hispanicus edwardsianus (Dugès, 1829) from eastern Spain, to the species level: Psammodromus hispanicus stat. nov. and Psammodromus edwardsianus stat. nov. Given that the holotype of Psammodromus hispanicus was lost, we designate a neotype. We also analysed museum specimens of P. blanci, P. microdactylus and P. algirus to describe differentiation of the Psammodromus hispanicus lineages/species from their closest relatives.

CX3CR1 is a modifying gene of survival and progression in Amyotrophic Lateral Sclerosis

The objective of this study was to investigate the association of functional variants of the human CX3CR1 gene (Fractalkine receptor) with the risk of Amyotrophic Lateral Sclerosis disease (ALS), the survival and the progression rate of the disease symptoms in a Spanish ALS cohort. 187 ALS patients (142sporadic [sALS] and 45 familial) and 378 controls were recruited. We investigated CX3CR1 V249I (rs3732379) and T280M (rs3732378) genotypes and their haplotypes as predictors of survival, the progression rate of the symptoms (as measured by ALSFRS-R and FVC decline) and the risk of suffering ALS disease. The results indicated that sALS patients with CX3CR1 249I/I or 249V/I genotypes presented a shorter survival time (42.21±4.82) than patients with 249V/V genotype (67.48±7.28; diff=-25.27 months 95%CI [-42.09,-8.45]; p=0.003). The survival time was shorter in sALS patients with spinal topography and CX3CR1 249I alleles (diff -29.78 months; 95%CI [-49.42,-10.14]; p=0.003). The same effects were also observed in the spinal sALS patients with 249I-280M haplotype (diff=-27.23 months; 95%CI [-49.83,-4.64]; p=0.018). In the sALS group, the CX3CR1 249I variant was associated with a faster progression of the disease symptoms (OR= 2.32; 95IC%[1.24, 4.33]; p=0.007). There was no evidence for association of these two CX3CR1 variants with ALS disease risk. The association evidenced herein is clinically relevant and indicates that CX3CR1 could be a disease-modifying gene in sALS. The progression rate of the disease"s symptoms and the survival time is affected in patients with one or two copies of the CX3CR1 249I allele. The CX3CR1 is the most potent ALS survival genetic factor reported to date. These results reinforce the role of the immune system in ALS pathogenesis.

The odd couple: contrasting phylogeographic patterns in two sympatric sibling species of woodlouse-­‐hunter spiders in the Canary Islands

Comparative phylogeography seeks for commonalities in the spatial demographic history of sympatric organisms to characterize the mechanisms that shaped such patterns. The unveiling of incongruent phylogeographic patterns in co-occurring species, on the other hand, may hint to overlooked differences in their life histories or microhabitat preferences. The woodlouse-hunter spiders of the genus Dysdera have undergone a major diversi cation on the Canary Islands. The species pair Dysdera alegranzaensis and Dysdera nesiotes are endemic to the island of Lanzarote and nearby islets, where they co-occur at most of their known localities. The two species stand in sharp contrast to other sympatric endemic Dysdera in showing no evidence of somatic (non-genitalic) differentiation. Phylogenetic and population genetic analyses of mitochondrial cox1 sequences from an exhaustive sample of D. alegranzaensis and D. nesiotes specimens, and additional mitochondrial (16S, L1, nad1) and nuclear genes (28S, H3) were analysed to reveal their phylogeographic patterns and clarify their phylogenetic relationships. Relaxed molecular clock models using ve calibration points were further used to estimate divergence times between species and populations. Striking differences in phylogeography and population structure between the two species were observed. Dysdera nesiotes displayed a metapopulation-like structure, while D. alegranzaensis was characterized by a weaker geographical structure but greater genetic divergences among its main haplotype lineages, suggesting more complex population dynamics. Our study con rms that co-distributed sibling species may exhibit contrasting phylogeographic patterns in the absence of somatic differentiation. Further ecological studies, however, will be necessary to clarify whether the contrasting phylogeographies may hint at an overlooked niche partitioning between the two species. In addition, further comparisons with available phylogeographic data of other eastern Canarian Dysdera endemics con rm the key role of lava ows in structuring local populations in oceanic islands and identify localities that acted as refugia during volcanic eruptions

Association of MMP-2 polymorphisms with severe and very severe COPD: a case control study of MMPs-1, 9 and 12 in a European population.

BACKGROUND: Genetic factors play a role in chronic obstructive pulmonary disease (COPD) but are poorly understood. A number of candidate genes have been proposed on the basis of the pathogenesis of COPD. These include the matrix metalloproteinase (MMP) genes which play a role in tissue remodelling and fit in with the protease--antiprotease imbalance theory for the cause of COPD. Previous genetic studies of MMPs in COPD have had inadequate coverage of the genes, and have reported conflicting associations of both single nucleotide polymorphisms (SNPs) and SNP haplotypes, plausibly due to under-powered studies. METHODS: To address these issues we genotyped 26 SNPs, providing comprehensive coverage of reported SNP variation, in MMPs- 1, 9 and 12 from 977 COPD patients and 876 non-diseased smokers of European descent and evaluated their association with disease singly and in haplotype combinations. We used logistic regression to adjust for age, gender, centre and smoking history. RESULTS: Haplotypes of two SNPs in MMP-12 (rs652438 and rs2276109), showed an association with severe/very severe disease, corresponding to GOLD Stages III and IV. CONCLUSIONS: Those with the common A-A haplotype for these two SNPs were at greater risk of developing severe/very severe disease (p = 0.0039) while possession of the minor G variants at either SNP locus had a protective effect (adjusted odds ratio of 0.76; 95% CI 0.61 - 0.94). The A-A haplotype was also associated with significantly lower predicted FEV1 (42.62% versus 44.79%; p = 0.0129). This implicates haplotypes of MMP-12 as modifiers of disease severity.

Between Immunology And Tolerance: Controlling Immune Responses Employing Tolerogenic Dendritic Cells

Dendritic cells (DCs) are the most efficient antigen presenting cells, they provide co-stimulation, are able to secrete various proinflammatory cytokines and therefore play a pivotal role in shaping adaptive immune responses. Moreover, they are important for the promotion and maintenance of central and peripheral tolerance through several mechanisms like the induction of anergy or apoptosis in effector T cells or by promoting regulatory T cells. The murine CD8α+ (MuTu) dendritic cell line was previously derived and described in our laboratory. The MuTu cell line has been shown to maintain phenotypical and functional characteristics of endogenous CD8α+ DCs. They are able to cross-present exogenous antigens to CD8+ T cells and produce interleukin (IL-) 12 upon engagement of Toll like receptors. The cell line constitutes an infinite source of homogenous, phenotypically well-defined dendritic cells. This allows us to investigate the role and potential of specific molecules in the induction as well as regulation of immune responses by DCs in a rational and standardized way. In a first project the MuTu dendritic cell line was transduced in order to stably express the immunosuppressive molecules IL-10, IL-35 or the active form of TGF-β (termed IL-10+DC, IL-35+DC or actTGFβ+DC). We investigated the capability of these potentially suppressive or tolerogenic dendritic cell lines to induce immune tolerance and explore the mechanisms behind tolerance induction. The expression of TGF-β by the DC line did not affect the phenotype of the DCs itself. In contrast, IL-10+ and IL-35+DCs were found to exhibit lower expression of co-stimulatory molecules and MHC class I and II, as well as reduced secretion of pro-inflammatory cytokines upon activation. In vitro co-culture with IL-35+, IL10+ or active TGFβ+ DCs interfered with function and proliferation of CD4+ and CD8+ T cells. Furthermore, IL-35 and active TGF-β expressing DC lines induced regulatory phenotype on CD4+ T cells in vitro without or with expression of Foxp3, respectively. In different murine cancer models, vaccination with IL-35 or active TGF-β expressing DCs resulted in faster tumor growth. Interestingly, accelerated tumor growth could be observed when IL-35-expressing DCs were injected into T cell-deficient RAG-/- mice. IL-10expressing DCs however, were found to rather delay tumor growth. Besides the mentioned autocrine effects of IL-35 expression on the DC line itself, we surprisingly observed that the expression of IL-35 or the addition of IL-35 containing medium enhances neutrophil survival and induces proliferation of endothelial cells. Our findings indicate that the cytokine IL-35 might not only be a potent regulator of adaptive immune responses, but it also implies IL-35 to mediate diverse effects on an array of cellular targets. This abilities make IL-35 a promising target molecule not only for the treatment of auto-inflammatory disease but also to improve anti-cancer immunotherapies. Indeed, by applying active TGFβ+ in murine autoimmune encephalitis we were able to completely inhibit the development of the disease, whereas IL-35+DCs reduced disease incidence and severity. Furthermore, the preventive transfer of IL-35+DCs delayed rejection of transplanted skin to the same extend as the combination of IL-10/actTGF-β expressing DCs. Thus, the expression of a single tolerogenic molecule can be sufficient to interfere with the adequate activation and function of dendritic cells and of co-cultured T lymphocytes. The respective mechanisms of tolerance induction seem to be different for each of the investigated molecule. The application of a combination of multiple tolerogenic molecules might therefore evoke synergistic effects in order to overcome (auto-) immunity. In a second project we tried to improve the immunogenicity of dendritic cell-based cancer vaccines using two different approaches. First, the C57BL/6 derived MuTu dendritic cell line was genetically modified in order to express the MHC class I molecule H-2Kd. We hypothesized that the expression of BALB/c specific MHC class I haplotype (H-2Kd) should allow the priming of tumor-specific CD8+ T cells by the otherwise allogeneic dendritic cells. At the same time, the transfer of these H-2Kd+ DCs into BALB/c mice was thought to evoke a strong inflammatory environment that might act as an "adjuvant", helping to overcome tumor induced immune suppression. Using this so called "semi-allogeneic" vaccination approach, we could demonstrate that the delivery of tumor lysate pulsed H-2Kd+ DCs significantly delayed tumor growth when compared to autologous or allogeneic vaccination. However, we were not able to coherently elucidate the cellular mechanisms underlying the observed effect. Second, we generated MuTu DC lines which stably express the pro-inflammatory cytokines IL-2, IL-12 or IL-15. We investigated whether the combination of DC vaccination and local delivery of pro-inflammatory cytokines might enhance tumor specific T cell responses. Indeed, we observed an enhanced T cell proliferation and activation when they were cocultured in vitro with IL-12 or IL-2-expressing DCs. But unfortunately we could not observe a beneficial or even synergistic impact on tumor development when cytokine delivery was combined with semi-allogeneic DC vaccination.

Interplay between connexin40 and nitric oxide signaling during hypertension.

Connexins (Cxs) and endothelial nitric oxide synthase (eNOS) contribute to the adaptation of endothelial and smooth muscle cells to hemodynamic changes. To decipher the in vivo interplay between these proteins, we studied Cx40-null mice, a model of renin-dependent hypertension which displays an altered endothelium-dependent relaxation of the aorta because of reduced eNOS levels. These mice, which were either untreated or subjected to the 1-kidney, 1-clip (1K1C) procedure, a model of volume-dependent hypertension, were compared with control mice submitted to either the 1K1C or the 2-kidney, 1-clip (2K1C) procedure, a model of renin-dependent hypertension. All operated mice became hypertensive and featured hypertrophy and altered Cx expression of the aorta. The combination of volume- and renin-dependent hypertension in Cx40-/- 1K1C mice raised blood pressure and cardiac weight index. Under these conditions, all aortas showed increased levels of Cx40 in endothelial cells and of both Cx37 and Cx45 in smooth muscle cells. In the wild-type 1K1C mice, the interactions between Cx40 and Cx37 with eNOS were enhanced, resulting in increased NO release. The Cx40-eNOS interaction could not be observed in mice lacking Cx40, which also featured decreased levels of eNOS. In these animals, the volume overload caused by the 1K1C procedure resulted in increased phosphorylation of eNOS and in a higher NO release. The findings provide evidence that Cx40 and Cx37 play an in vivo role in the regulation of eNOS.

A founder CEP120 mutation in Jeune asphyxiating thoracic dystrophy expands the role of centriolar proteins in skeletal ciliopathies.

Jeune asphyxiating thoracic dystrophy (JATD) is a skeletal dysplasia characterized by a small thoracic cage and a range of skeletal and extra-skeletal anomalies. JATD is genetically heterogeneous with at least nine genes identified, all encoding ciliary proteins, hence the classification of JATD as a skeletal ciliopathy. Consistent with the observation that the heterogeneous molecular basis of JATD has not been fully determined yet, we have identified two consanguineous Saudi families segregating JATD who share a single identical ancestral homozygous haplotype among the affected members. Whole-exome sequencing revealed a single novel variant within the disease haplotype in CEP120, which encodes a core centriolar protein. Subsequent targeted sequencing of CEP120 in Saudi and European JATD cohorts identified two additional families with the same missense mutation. Combining the four families in linkage analysis confirmed a significant genome-wide linkage signal at the CEP120 locus. This missense change alters a highly conserved amino acid within CEP120 (p.Ala199Pro). In addition, we show marked reduction of cilia and abnormal number of centrioles in fibroblasts from one affected individual. Inhibition of the CEP120 ortholog in zebrafish produced pleiotropic phenotypes characteristic of cilia defects including abnormal body curvature, hydrocephalus, otolith defects and abnormal renal, head and craniofacial development. We also demonstrate that in CEP120 morphants, cilia are shortened in the neural tube and disorganized in the pronephros. These results are consistent with aberrant CEP120 being implicated in the pathogenesis of JATD and expand the role of centriolar proteins in skeletal ciliopathies.

A functional variant in the Stearoyl-CoA desaturase gene promoter enhances fatty acid desaturation in pork

There is growing public concern about reducing saturated fat intake. Stearoyl-CoA desaturase (SCD) is the lipogenic enzyme responsible for the biosynthesis of oleic acid (18:1) by desaturating stearic acid (18:0). Here we describe a total of 18 mutations in the promoter and 3′ non-coding region of the pig SCD gene and provide evidence that allele T at AY487830:g.2228T>C in the promoter region enhances fat desaturation (the ratio 18:1/18:0 in muscle increases from 3.78 to 4.43 in opposite homozygotes) without affecting fat content (18:0+18:1, intramuscular fat content, and backfat thickness). No mutations that could affect the functionality of the protein were found in the coding region. First, we proved in a purebred Duroc line that the C-T-A haplotype of the 3 single nucleotide polymorphisms (SNPs) (g.2108C>T; g.2228T>C; g.2281A>G) of the promoter region was additively associated to enhanced 18:1/18:0 both in muscle and subcutaneous fat, but not in liver. We show that this association was consistent over a 10-year period of overlapping generations and, in line with these results, that the C-T-A haplotype displayed greater SCD mRNA expression in muscle. The effect of this haplotype was validated both internally, by comparing opposite homozygote siblings, and externally, by using experimental Duroc-based crossbreds. Second, the g.2281A>G and the g.2108C>T SNPs were excluded as causative mutations using new and previously published data, restricting the causality to g.2228T>C SNP, the last source of genetic variation within the haplotype. This mutation is positioned in the core sequence of several putative transcription factor binding sites, so that there are several plausible mechanisms by which allele T enhances 18:1/18:0 and, consequently, the proportion of monounsaturated to saturated fat.

Natural or naturalized? phylogeography suggests that the abundant sea urchin arbacia lixula Is a recent Colonizer of the Mediterranean

We present the global phylogeography of the black sea urchin Arbacia lixula, an amphi-Atlantic echinoid with potential to strongly impact shallow rocky ecosystems. Sequences of the mitochondrial cytochrome c oxidase gene of 604 specimens from 24 localities were obtained, covering most of the distribution area of the species, including the Mediterranean and both shores of the Atlantic. Genetic diversity measures, phylogeographic patterns, demographic parameters and population differentiation were analysed. We found high haplotype diversity but relatively low nucleotide diversity, with 176 haplotypes grouped within three haplogroups: one is shared between Eastern Atlantic (including Mediterranean) and Brazilian populations, the second is found in Eastern Atlantic and the Mediterranean and the third is exclusively from Brazil. Significant genetic differentiation was found between Brazilian, Eastern Atlantic and Mediterranean regions, but no differentiation was found among Mediterranean sub-basins or among Eastern Atlantic sub-regions. The star-shaped topology of the haplotype network and the unimodal mismatch distributions of Mediterranean and Eastern Atlantic samples suggest that these populations have suffered very recent demographic expansions. These expansions could be dated 94-205 kya in the Mediterranean, and 31-67 kya in the Eastern Atlantic. In contrast, Brazilian populations did not show any signature of population expansion. Our results indicate that all populations of A. lixula constitute a single species. The Brazilian populations probably diverged from an Eastern Atlantic stock. The present-day genetic structure of the species in Eastern Atlantic and the Mediterranean is shaped by very recent demographic processes. Our results support the view (backed by the lack of fossil record) that A. lixula is a recent thermophilous colonizer which spread throughout the Mediterranean during a warm period of the Pleistocene, probably during the last interglacial. Implications for the possible future impact of A. lixula on shallow Mediterranean ecosystems in the context of global warming trends must be considered.

Common Variants of TLR1 Associate with Organ Dysfunction and Sustained Pro- Inflammatory Responses during Sepsis

Background: Toll-like receptors (TLRs) are critical components for host pathogen recognition and variants in genes participating in this response influence susceptibility to infections. Recently, TLR1 gene polymorphisms have been found correlated with whole blood hyper-inflammatory responses to pathogen-associated molecules and associated with sepsis-associated multiorgan dysfunction and acute lung injury (ALI). We examined the association of common variants of TLR1 gene with sepsis-derived complications in an independent study and with serum levels for four inflammatory biomarker among septic patients. Methodology/Principal Findings: Seven tagging single nucleotide polymorphisms of the TLR1 gene were genotyped in samples from a prospective multicenter case-only study of patients with severe sepsis admitted into a network of intensive care units followed for disease severity. Interleukin (IL)-1 b, IL-6, IL-10, and C-reactive protein (CRP) serum levels were measured at study entry, at 48 h and at 7th day. Alleles -7202G and 248Ser, and the 248Ser-602Ile haplotype were associated with circulatory dysfunction among severe septic patients (0.001<=p <= 0.022), and with reduced IL-10 (0.012<= p <=0.047) and elevated CRP (0.011<= p <=0.036) serum levels during the first week of sepsis development. Additionally, the -7202GG genotype was found to be associated with hospital mortality (p =0.017) and ALI (p =0.050) in a combined analysis with European Americans, suggesting common risk effects among studies Conclusions/Significance: These results partially replicate and extend previous findings, supporting that variants of TLR1 gene are determinants of severe complications during sepsis.

The odd couple: contrasting phylogeographic patterns in two sympatric sibling species of woodlouse-­‐hunter spiders in the Canary Islands

Comparative phylogeography seeks for commonalities in the spatial demographic history of sympatric organisms to characterize the mechanisms that shaped such patterns. The unveiling of incongruent phylogeographic patterns in co-occurring species, on the other hand, may hint to overlooked differences in their life histories or microhabitat preferences. The woodlouse-hunter spiders of the genus Dysdera have undergone a major diversi cation on the Canary Islands. The species pair Dysdera alegranzaensis and Dysdera nesiotes are endemic to the island of Lanzarote and nearby islets, where they co-occur at most of their known localities. The two species stand in sharp contrast to other sympatric endemic Dysdera in showing no evidence of somatic (non-genitalic) differentiation. Phylogenetic and population genetic analyses of mitochondrial cox1 sequences from an exhaustive sample of D. alegranzaensis and D. nesiotes specimens, and additional mitochondrial (16S, L1, nad1) and nuclear genes (28S, H3) were analysed to reveal their phylogeographic patterns and clarify their phylogenetic relationships. Relaxed molecular clock models using ve calibration points were further used to estimate divergence times between species and populations. Striking differences in phylogeography and population structure between the two species were observed. Dysdera nesiotes displayed a metapopulation-like structure, while D. alegranzaensis was characterized by a weaker geographical structure but greater genetic divergences among its main haplotype lineages, suggesting more complex population dynamics. Our study con rms that co-distributed sibling species may exhibit contrasting phylogeographic patterns in the absence of somatic differentiation. Further ecological studies, however, will be necessary to clarify whether the contrasting phylogeographies may hint at an overlooked niche partitioning between the two species. In addition, further comparisons with available phylogeographic data of other eastern Canarian Dysdera endemics con rm the key role of lava ows in structuring local populations in oceanic islands and identify localities that acted as refugia during volcanic eruptions

Polymorphisms in DNA-repair genes in a cohort of prostate cancer patients from different areas in Spain: heterogeneity between populations as a confounding factor in association studies

Background: Differences in the distribution of genotypes between individuals of the same ethnicity are an important confounder factor commonly undervalued in typical association studies conducted in radiogenomics. Objective: To evaluate the genotypic distribution of SNPs in a wide set of Spanish prostate cancer patients for determine the homogeneity of the population and to disclose potential bias. Design, Setting, and Participants: A total of 601 prostate cancer patients from Andalusia, Basque Country, Canary and Catalonia were genotyped for 10 SNPs located in 6 different genes associated to DNA repair: XRCC1 (rs25487, rs25489, rs1799782), ERCC2 (rs13181), ERCC1 (rs11615), LIG4 (rs1805388, rs1805386), ATM (rs17503908, rs1800057) and P53 (rs1042522). The SNP genotyping was made in a Biotrove OpenArrayH NT Cycler. Outcome Measurements and Statistical Analysis: Comparisons of genotypic and allelic frequencies among populations, as well as haplotype analyses were determined using the web-based environment SNPator. Principal component analysis was made using the SnpMatrix and XSnpMatrix classes and methods implemented as an R package. Non-supervised hierarchical cluster of SNP was made using MultiExperiment Viewer. Results and Limitations: We observed that genotype distribution of 4 out 10 SNPs was statistically different among the studied populations, showing the greatest differences between Andalusia and Catalonia. These observations were confirmed in cluster analysis, principal component analysis and in the differential distribution of haplotypes among the populations. Because tumor characteristics have not been taken into account, it is possible that some polymorphisms may influence tumor characteristics in the same way that it may pose a risk factor for other disease characteristics. Conclusion: Differences in distribution of genotypes within different populations of the same ethnicity could be an important confounding factor responsible for the lack of validation of SNPs associated with radiation-induced toxicity, especially when extensive meta-analysis with subjects from different countries are carried out.

Endothelial Connexin37 and Connexin40 participate in basal but not agonist-induced NO release.

BACKGROUND: Connexin37 (Cx37) and Cx40 are crucial for endothelial cell-cell communication and homeostasis. Both connexins interact with endothelial nitric oxide synthase (eNOS). The exact contribution of these interactions to the regulation of vascular tone is unknown. RESULTS: Cx37 and Cx40 were expressed in close proximity to eNOS at cell-cell interfaces of mouse aortic endothelial cells. Absence of Cx37 did not affect expression of Cx40 and a 50 % reduction of Cx40 in Cx40(+/-) aortas did not affect the expression of Cx37. However, absence of Cx40 was associated with reduced expression of Cx37. Basal NO release and the sensitivity for ACh were decreased in Cx37(-/-) and Cx40(-/-) aortas but not in Cx40(+/-) aortas. Moreover, ACh-induced release of constricting cyclooxygenase products was present in WT, Cx40(-/-) and Cx40(+/-) aortas but not in Cx37(-/-) aortas. Finally, agonist-induced NO-dependent relaxations and the sensitivity for exogenous NO were not affected by genotype. CONCLUSIONS: Cx37 is more markedly involved in basal NO release, release of cyclooxygenase products and the regulation of the sensitivity for ACh as compared to Cx40.

Dysferlinopathy in Switzerland: clinical phenotypes and potential founder effects.

BACKGROUND: Dysferlin is reduced in patients with limb girdle muscular dystrophy type 2B, Miyoshi myopathy, distal anterior compartment myopathy, and in certain Ethnic clusters. METHODS: We evaluated clinical and genetic patient data from three different Swiss Neuromuscular Centers. RESULTS: Thirteen patients from 6 non-related families were included. Age of onset was 18.8 ± 4.3 years. In all patients, diallelic disease-causing mutations were identified in the DYSF gene. Nine patients from 3 non-related families from Central Switzerland carried the identical homozygous mutation, c.3031 + 2T>C. A possible founder effect was confirmed by haplotype analysis. Three patients from two different families carried the heterozygous mutation, c.1064_1065delAA. Two novel mutations were identified (c.2869C>T (p.Gln957Stop), c.5928G>A (p.Trp1976Stop)). CONCLUSIONS: Our study confirms the phenotypic heterogeneity associated with DYSF mutations. Two mutations (c.3031 + 2T>C, c.1064_1065delAA) appear common in Switzerland. Haplotype analysis performed on one case (c. 3031 + 2T>C) suggested a possible founder effect.

Caveolin-1-mediated post-transcriptional regulation of inducible nitric oxide synthase in human colon carcinoma cells.

Reactive oxygen species are now widely recognized as important players contributing both to cell homeostasis and the development of disease. In this respect nitric oxide (NO) is no exception. The discussion here will center on regulation of the inducible form of nitric oxide synthase (iNOS) for two reasons. First, only iNOS produces micromolar NO concentrations, amounts that are high by comparison with the picomolar to nanomolar concentrations resulting from Ca2(+)-controlled NO production by endothelial eNOS or neuronal nNOS. Second, iNOS is not constitutively expressed in cells and regulation of this isoenzyme, in contrast to endothelial eNOS or neuronal nNOS, is widely considered to occur at the transcriptional level only. In particular, we were interested in the possibility that caveolin-1, a protein that functions as a tumor suppressor in colon carcinoma cells (Bender et al., 2002; this issue), might regulate iNOS activity. Our results provide evidence for the existence of a post-transcriptional mechanism controlling iNOS protein levels that involves caveolin-1-dependent sequestration of iNOS within a detergent-insoluble compartment. Interestingly, despite the high degree of conservation of the caveolin-1 scaffolding domain binding motif within all NOS enzymes, the interaction detected between caveolin-1 and iNOS in vitro is crucially dependent on presence of a caveolin-1 sequence element immediately adjacent to the scaffolding domain. A model is presented summarizing the salient aspects of these results. These observations are important in the context of tumor biology, since down-regulation of caveolin-1 is predicted to promote uncontrolled iNOS activity, genotoxic damage and thereby facilitate tumor development in humans.