Cyclo(His-Pro) up-regulates heme oxygenase 1 via activation of Nrf2-ARE signalling

Paraquat (1,1'-dimethyl-4,4'-bipyridinium), a widely used non-selective herbicide, is a redox cycling agent with adverse effects on dopamine systems. Epidemiological data have shown that exposure to paraquat is one of the several risk factors for Parkinson's disease. We have already shown that cyclo(His-Pro), an endogenous cyclic dipeptide produced by the cleavage of the thyrotropin releasing hormone, has a cytoprotective effect through a mechanism involving Nrf2 activation that decreases production of reactive oxygen species and increases glutathione synthesis. Using primary neuronal cultures and PC12 cells as targets of paraquat neurotoxicity, we addressed whether and how cyclo(His-Pro) causes cellular protective response against paraquat-mediated cell death. We found that cyclo(His-Pro) attenuated reactive oxygen species production, and prevented glutathione depletion by up-regulating Nrf2 gene expression, triggering its nuclear accumulation and activating the expression of heme oxygenase1. These protective effects were abolished by RNA interference-mediated Nrf2 knock down whereas were unaffected by RNA interference-mediated Keap1 knock down. Inhibition of heme oxygenase activity decreased cyclo(His-Pro)-induced neuroprotection. These results suggest that cyclo(His-Pro), acting as a selective activator of the brain modulable Nrf2 pathway, may be a promising candidate as neuroprotective agent that act through induction of phase II genes.     

Genetic diversity of durum wheat as determined by AFLP in fluorescence

The DNA of fifteen Italian cultivars of durum wheat (Triticum turgidum L. ssp. durum) were analyzed by in fluorescence amplified fragment length polymorphism (fAFLP) in order to obtain the characteristic fingerprintings of genotypes and assess their genetic relatedness. Among 64 combinations of fluorescence labelled primers, three different combinations were chosen as producing a total of 6630 AFLP fragments, 2277 (34.3 %) of them being polymorphic. By using this fAFLP methodology a DNA fingerprinting of each durum wheat cultivar was generated for genotype identification. Analysis of the genetic relationships show the low variability among durum wheat cultivars.     

Pectolytic clostridia isolated from sugar beet pulp silages in Italy

Twenty-eight strains of pectolytic clostridia were isolated from sugar beet pulp silages. Seventeen non-pigmented strains were presumed to be Clostridium acetobutylicum ; the remaining 11 pigmented strains were similar to Cl. felsineum. The addition of molasses to sugar beet pulps favoured the growth of other bacteria, particularly lactic acid organisms, whereas pectolytic clostridia were only occasionally found. The pectolytic clostridia promoted the structure loss of simulated silages. The use of molasses in sugar beet pulp ensiling was suggested to prevent texture loss of the ensiled mass.     

The Redox Biochemistry of Protein Sulfenylation and Sulfinylation

Controlled generation of reactive oxygen species orchestrates numerous physiological signaling events (Finkel, T. (2011) Signal transduction by reactive oxygen species. J. Cell Biol. 194, 7–15). A major cellular target of reactive oxygen species is the thiol side chain (RSH) of Cys, which may assume a wide range of oxidation states (i.e. −2 to +4). Within this context, Cys sulfenic (Cys-SOH) and sulfinic (Cys-SO₂H) acids have emerged as important mechanisms for regulation of protein function. Although this area has been under investigation for over a decade, the scope and biological role of sulfenic/sulfinic acid modifications have been recently expanded with the introduction of new tools for monitoring cysteine oxidation in vitro and directly in cells. This minireview discusses selected recent examples of protein sulfenylation and sulfinylation from the literature, highlighting the role of these post-translational modifications in cell signaling.     

Functional morphology of the neck organ in Artemia salina nauplii

Fine structure of the ion transporting epithelium of the neck organ in the brine shrimp (Artemia salina) nauplius is described. The neck organ is a dome-like gland situated atop the cephalothorax of the larva and is composed of 50 to 60 cuboidal epithelial cells. These cells possess many of the characteristics of salt-secretory cells from other tissues. They contain many mitochondria and exhibit a high degree of plasma membrane elaboration. This membrane amplification takes two forms; the apical plasmalemma is infolded into irregular loops, while the basal and lateral membranes penetrate the cytoplasm in the form of branching sinusoids. The labyrinth of tubular reticulum thus formed fills most of the cell volume. Mitochondria in the labyrinth are often in intimate contact with these tubular membranes and regular arrays of parallel mitochondria with constricted intervening sinusoids are often observed. Other organelles including Golgi complexes, multivesicular bodies, and rough endoplasmic reticulum are also numerous, particularly in the narrow rim of cytoplasm which lies between the apical infolds and the labyrinth. Yolk platelets and glycogen fields are conspicuous in the basal perinuclear regions of the cells.     

A fish oil diet inhibits amyloid P component (AP) acute phase responses in arthritis susceptible mice

Amyloid P component (AP) bears close homology with C-reactive protein and behaves as an acute phase reactant in the plasma of mice but not in man. Our aim was to determine whether AP is influenced by diet, gender, and arthritis severity in a murine model of arthritis. B10.RIII mice were segregated according to gender and diet at 8 wk of age: the source of fat was either corn oil, fish oil, or beef tallow (5% by weight). Four weeks later, each mouse was immunized with 100 micrograms fetal bovine type II collagen, and the incidence and severity of arthritis was noted at weekly intervals. AP was measured by competitive ELISA in plasma taken 5 wk and 15 wk after immunization. AP levels were less in fish oil fed males and females. Under all conditions tested AP levels of females were greater than in males. There was a negative correlation between AP levels and the severity of arthritis. We conclude from these data that although AP levels cannot be used as indices of arthritis severity, there are significant dietary and gender effects on AP concentrations as long as 15 wk after immunization with type II collagen.     

Treatment of Ph+ chronic myeloid leukemia by gamma interferon

The clinical, hematologic and cytogenetic effects of human recombinant gamma interferon (IFN) were investigated in 14 patients with Ph+ chronic myeloid leukemia (CML). Gamma-IFN was given at a daily dosage of 0.50 mg (= 10 x 10(6) U)/m2 from the 3rd week of treatment on, but the dosage had to be reduced to 0.25 mg/m2 in 10 cases and to 0.35 mg/m2 in 2 cases, because of the severity and persistence of side effects (mainly fever, fatigue, headache and pain). Only 2 patients tolerated the full dosage. The overall response rate was 64% (1 complete and 8 partial hematologic responses). Only patients in stable chronic phase responded. Two out of two patients in unstable chronic phase and two out of two patients in accelerated phase failed to respond. Eight out of nine responding patients remained in remission throughout the duration of treatment (30 to 35 weeks). No karyotypic conversion was detected. These data show that gamma IFN alone is effective in Ph+ CML, but that side effects can limit substantially the dosage and duration of treatment.     

Nearshore and pelagic abundances of Artemia monica in Mono Lake,California

The spatial distribution and abundance of the brine shrimp, Artemia monica, in Mono Lake, California were determined during 1982 and 1983. Peak abundances of shrimp occur in midsummer and reach densities of 15–17 individuals l^-1 in the nearshore regions and 6–8 individuals 1^-1 in the pelagic region. The brine shrimp were non-uniformly distributed both vertically and horizontally. The coefficient of variation in shrimp abundance among stations within the nearshore region was similar to that found in the pelagic region. On two of the nine dates, nearshore densities were 3 to 4 times greater than those in the pelagic zone, and on average the brine shrimp appear to be slightly over-dispersed to the nearshore region. However, including nearshore abundances in lakewide estimates will usually result in a change of less than a 10%.