Sarm1 activation produces cADPR to increase intra-axonal Ca++ and promote axon degeneration in PIPN

Cancer patients frequently develop chemotherapy-induced peripheral neuropathy (CIPN), a painful and long-lasting disorder with profound somatosensory deficits. There are no effective therapies to prevent or treat this disorder. Pathologically, CIPN is characterized by a “dying-back” axonopathy that begins at intra-epidermal nerve terminals of sensory neurons and progresses in a retrograde fashion. Calcium dysregulation constitutes a critical event in CIPN, but it is not known how chemotherapies such as paclitaxel alter intra-axonal calcium and cause degeneration. Here, we demonstrate that paclitaxel triggers Sarm1-dependent cADPR production in distal axons, promoting intra-axonal calcium flux from both intracellular and extracellular calcium stores. Genetic or pharmacologic antagonists of cADPR signaling prevent paclitaxel-induced axon degeneration and allodynia symptoms, without mitigating the anti-neoplastic efficacy of paclitaxel. Our data demonstrate that cADPR is a calcium-modulating factor that promotes paclitaxel-induced axon degeneration and suggest that targeting cADPR signaling provides a potential therapeutic approach for treating paclitaxel-induced peripheral neuropathy (PIPN).     

Tumorigenicity of EJ-ras oncogene transformed NIH 3T3 cells and expression of plasminogen activators

A number of clonal cell lines have been isolated from NIH 3T3 cells transfected with the plasmid, pSV2 gpt-EJ-ras. The plasmid expresses Val12 instead of Gly12 in p21 ras protein and can be selected for the expression of E. coli XGPRT gene in mammalian cells. Southern analyses of the Eco R1 and Bam H1 digests of chromosomal DNA shows that multiple copies of the plasmid are integrated in a tandem sequence in the clones used in this study. The transfectants showed refractile appearance and criss-crossed pattern of growth, exhibited elevated expression of ras mRNA and formed tumors in nude mice commensurate with the copy number of the integrated EJ-ras gene. The increased propensity to form tumors did not correlate with the expression of urinary or tissue plasminogen activators (u-PA or t-PA). The cellular and secreted activity of u-PA in fact decreased as the ras gene expression increased. These data show that the enhanced tumorigenicity of transformed murine cells is related to the tandem integration and expression of human EJ-ras. The overexpression of ras has very little effect on t-PA but appears to suppress u-PA activity.     

Genetic heterogeneity at the bovine KIT gene in cattle breeds carrying different putative alleles at the spotting locus

According to classical genetic studies, piebaldism in cattle is largely influenced by the allelic series at the spotting locus (S), which includes the S^H (Hereford pattern), S⁺ (non‐spotted) and s (spotted) alleles. The S locus was mapped on bovine chromosome 6 in the region containing the KIT gene. We investigated the KIT gene, analysing its variability and haplotype distribution in cattle of three breeds (Angus, Hereford and Holstein) with different putative alleles (S⁺, S^H and s respectively) at the S locus. Resequencing of a whole of 0.485 Mb revealed 111 polymorphisms. The global nucleotide diversity was 0.087%. Tajima’s D‐values were negative for all breeds, indicating putative directional selection. Of the 28 inferred haplotypes, only five were observed in the Hereford breed, in which one was the most frequent. Coalescent simulation showed that it is highly unlikely (P < 10E‐6) to obtain this low number of haplotypes conditionally on the observed number of segregating SNPs. Therefore, the neutral model could be rejected for the Hereford breed, suggesting that a selection sweep occurred at the KIT locus. Twelve haplotypes were inferred in Holstein and Angus. For these two breeds, the neutral model could not be rejected. High heterogeneity of the KIT gene was confirmed from a phylogenetic analysis. Our results suggest a role of the KIT gene in determining the S^H allele(s) in the Hereford, but no evidence of selective sweep was obtained in Holstein, suggesting that complex mechanisms (or other genes) might be the cause of the spotted phenotype in this breed.     

Technological properties of Oenococcus oeni strains isolated from typical southern Italian wines

Aims: To isolate indigenous Oenococcus oeni strains suitable as starters for malolactic fermentation (MLF), using a reliable polyphasic approach. Methods and Results: Oenococcus oeni strains were isolated from Nero di Troia wines undergoing spontaneous MLF. Samples were taken at the end of alcoholic fermentation and during MLF. Wine samples were diluted in a sterile physiological solution and plated on MRS and on modified FT80. Identification of O. oeni strains was performed by a polymerase chain reaction (PCR) experiment using strain‐specific primers. Strains were further grouped using a multiplex RAPD‐PCR analysis. Then, six strains were inoculated in two wine‐like media with two different ethanol concentrations (11 and 13% vol/vol) with a view to evaluate their capacity to grow and to perform MLF. In addition, a quantitative PCR (qRT‐PCR) approach was adapted to monitor the physiological state of the strains selected. Conclusion: A positive correlation between the malolactic activity performance and the ability to develop and tolerate stress conditions was observed for two selected O. oeni strains. Significance and Impact of the Study: The results reported are useful for the selection of indigenous MLF starter cultures with desired oenological traits from typical regional wines. It should be the base for the improvement in organoleptic quality of typical red wine.     

Heat-induced unfolding of neocarzinostatin, a small all-beta protein investigated by small-angle X-ray scattering

Neocarzinostatin is an all-beta protein, 113 amino acid residues long, with an immunoglobulin-like fold. Its thermal unfolding has been studied by small-angle X-ray scattering. Preliminary differential scanning calorimetry and fluorescence measurements suggest that the transition is not a simple, two-state transition. The apparent radius of gyration is determined using three different approaches, the validity of which is critically assessed using our experimental data as well as a simple, two-state model. Similarly, each step of data analysis is evaluated and the underlying assumptions plainly stated. The existence of at least one intermediate state is formally demonstrated by a singular value decomposition of the set of scattering patterns. We assume that the pattern of the solution before the onset of the transition is that of the native protein, and that of the solution at the highest temperature is that of the completely unfolded protein. Given these, actually not very restrictive, boundary constraints, a least-squares procedure yields a scattering pattern of the intermediate state. However, this solution is not unique: a whole class of possible solutions is derived by adding to the previous linear combination of the native and completely unfolded states. Varying the initial conditions of the least-squares calculation leads to very similar solutions. Whatever member of the class is considered, the conformation of this intermediate state appears to be weakly structured, probably less than the transition state should be according to some proposals. Finally, we tried and used the classical model of three thermodynamically well-defined states to account for our data. The failure of the simple thermodynamic model suggests that there is more than the single intermediate structure required by singular value decomposition analysis. Formally, there could be several discrete intermediate species at equilibrium, or an ensemble of conformations differently populated according to the temperature. In the latter case, a third state would be a weighted average of all non native and not completely unfolded states of the protein but, since the weights change with temperature, no meaningful curve is likely to be derived by a global analysis using the simple model of three thermodynamically well-defined states.     

Effect of inhibitors of oxygen radical and nitric oxide formation on UV radiation-induced erythema, immunosuppression and carcinogenesis

We investigated whether supplementation of a sunscreen containing the UVB absorber 2-ethyl-hexyl-methoxycinnamate (cinnamate) with oxygen radical inhibitors (ORI) would improve protection from sunburn, immunosuppression and carcinogenesis. Mice were exposed to solar-simulated UV radiation (ssUV) containing a mixture of UVB and UVA. In initial studies, the ORI 2,2'-dipyridyl and N(G)-monomethyl-L-arginine acetate (L-NMMA) were shown to prevent UVA-induced suppression of contact sensitivity (CS) in mice. Addition of these inhibitors to the sunscreen did not affect the sun protection factor (SPF), but lowered the level of edema when mice were exposed to ssUV. Combination of both inhibitors with the sunscreen, however, increased the SPF from 5 to 5.5. The immune protection factor (IPF) of the sunscreen was only 1.18, but addition of neither dipyridyl nor L-NMMA singly or in combination measurably improved immune protection. However, the ORI improved the ability of the sunscreen to prevent carcinogenesis. The results indicate that reactive oxygen or nitrogen species produced in response to UV radiation are important for erythema, immunosuppression and carcinogenesis, and addition of inhibitors improves the protective capacity of sunscreens.