Relevance of transforming growth factor-beta1, interleukin-8, and tumor necrosis factor-alpha polymorphisms in patients with chronic pancreatitis

Cytokine regulation may be an important factor in the susceptibility for the development of chronic pancreatitis; transforming growth factor-beta1 (TGF-beta1) plays a central role in the pathogenesis of pancreatic fibrogenesis. The aim of our study was to analyse the relevance of TGF-beta1, interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-alpha) polymorphisms in patients with chronic pancreatitis. PATIENTS: of the 83 patients enrolled in the study, 43 were treated medically and 40 patients underwent surgical intervention. Healthy blood donors (n=75) served as controls. METHODS: the polymorphisms of TGF-beta1 +869 T--> C and IL-8 -251 T-->A were determined by the ARMS method, while that of TNF-alpha -308 was investigated using NcoI RFLP. RESULTS: there was a higher frequency (50%) of the TT genotype of TGF-beta1 +869, with a concomitantly higher TGF-beta1 level in the plasma (5.2 +/- 1.7 ng/mL) of patients with chronic pancreatitis than in healthy blood donors (28% and 2.8 +/- 0.9 ng/mL respectively). The number of TT homozygotes differed significantly between the patients who underwent surgical intervention and the controls, and even between the surgical and the non-surgical patients. The frequency of the T/A genotype with higher IL-8 production, was significantly higher in both groups of patients than in the controls (58% and 58% versus 40%). No correlation was found between the TNF-alpha -308 polymorphism and chronic pancreatitis. CONCLUSIONS: correlations of the TGF-beta1 and IL-8 single nucleotide polymorphisms (SNPs) with chronic pancreatitis underline the importance of these cytokines in the pathomechanism of the disease. Moreover, it seems that the TT genotype of +869 TGF-beta1 might be a risk factor for the development of a severe form of chronic pancreatitis, and could serve as a prognostic sign for any future surgical intervention or even repeat surgery. Further studies on a larger group of patients, in addition to a follow-up study, are necessary to confirm this preliminary observation.     

Identification of Site-Specific Recombination Genes int and xis of the Rhizobium Temperate Phage 16-3

Phage 16-3 is a temperate phage of Rhizobium meliloti 41 which integrates its genome with high efficiency into the host chromosome by site-specific recombination through DNA sequences of attB and attP. Here we report the identification of two phage-encoded genes required for recombinations at these sites: int (phage integration) and xis (prophage excision). We concluded that Int protein of phage 16-3 belongs to the integrase family of tyrosine recombinases. Despite similarities to the cognate systems of the lambdoid phages, the 16-3 int xis att system is not active in Escherichia coli, probably due to requirements for host factors that differ in Rhizobium meliloti and E. coli. The application of the 16-3 site-specific recombination system in biotechnology is discussed.     

Separation of Neurospora crassa myo-inositol-1-phosphate synthase from glucose-6-phosphate dehydrogenase by affinity chromatography

The purification of Neurospora crassa myo-inositol-1-phosphate synthase (EC 5.5.1.4) was studied by affinity chromatography using the substrate (glucose-6-phosphate), the inhibitor (pyrophosphate), the coenzyme (NAD+) and the coenzyme analogues (5'AMP and Cibacron Blue F3G-A) of the enzyme as adsorbents attached to agarose gel. Myo-inositol-1-phosphate synthase could be separated completely from the contaminating substance, glucose-6-phosphate dehydrogenase (EC 1.1.1.49), on Blue Sepharose CL-6B and on pyrophosphate-Sepharose. The purified enzyme had a specific activity of 16 400 U/mg. The sodium dodecyl sulfate/polyacrylamide gel electrophoresis of the 60 micrograms of this purified enzyme gave a homogenous band. The enzyme was found to be composed of four identical subunits having a molecular weight of 65 000.     

Reduced Estradiol-Induced Vasodilation and Poly-(ADP-Ribose) Polymerase (PARP) Activity in the Aortas of Rats with Experimental Polycystic Ovary Syndrome (PCOS)

Polycystic ovary syndrome (PCOS) is a complex endocrine disorder characterized by hyperandrogenism and insulin resistance, both of which have been connected to atherosclerosis. Indeed, an increased risk of clinical manifestations of arterial vascular diseases has been described in PCOS. On the other hand endothelial dysfunction can be detected early on, before atherosclerosis develops. Thus we assumed that vascular dysfunction is also related directly to the hormonal imbalance rather than to its metabolic consequences. To detect early functional changes, we applied a novel rodent model of PCOS: rats were either sham operated or hyperandrogenism was achieved by implanting subcutaneous pellets of dihydrotestosterone (DHT). After ten weeks, myograph measurements were performed on isolated aortic rings. Previously we described an increased contractility to norepinephrine (NE). Here we found a reduced immediate relaxation to estradiol treatment in pre-contracted aortic rings from hyperandrogenic rats. Although the administration of vitamin D₃ along with DHT reduced responsiveness to NE, it did not restore relaxation to estradiol. Poly-(ADP-ribose) polymerase (PARP) activity was assessed by poly-ADP-ribose immunostaining. Increased PAR staining in ovaries and circulating leukocytes from DHT rats showed enhanced DNA damage, which was reduced by concomitant vitamin D₃ treatment. Surprisingly, PAR staining was reduced in both the endothelium and vascular smooth muscle cells of the aorta rings from hyperandrogenic rats. Thus in the early phase of PCOS, vascular tone is already shifted towards vasoconstriction, characterized by reduced vasorelaxation and vascular dysfunction is concomitant with altered PARP activity. Based on our findings, PARP inhibitors might have a future perspective in restoring metabolic disorders in PCOS.     

Prevalence and risk factors of vertebral compression fractures in female SLE patients

Introduction  

Our objective was to determine the frequency of and factors associated with prevalent vertebral compression fractures in female systemic lupus erythematosus (SLE) patients attending rheumatologists in western Sweden.     

Comparison of originator and biosimilar therapeutic monoclonal antibodies using comprehensive two-dimensional liquid chromatography coupled with time-of-flight mass spectrometry

As research, development, and manufacturing of biosimilar protein therapeutics proliferates, there is great interest in the continued development of a portfolio of complementary analytical methods that can be used to efficiently and effectively characterize biosimilar candidate materials relative to the respective reference (i.e., originator) molecule. Liquid phase separation techniques such as liquid chromatography and capillary electrophoresis are powerful tools that can provide both qualitative and quantitative information about similarities and differences between reference and biosimilar materials, especially when coupled with mass spectrometry. However, the inherent complexity of these protein materials challenges even the most modern one-dimensional (1D) separation methods. Two-dimensional (2D) separations present a number of potential advantages over 1D methods, including increased peak capacity, 2D peak patterns that can facilitate unknown identification, and improvement in the compatibility of some separation methods with mass spectrometry. In this study, we demonstrate the use of comprehensive 2D-LC separations involving cation-exchange (CEX) and reversed-phase (RP) separations in the first and second dimensions to compare 3 reference/biosimilar pairs of monoclonal antibodies (cetuximab, trastuzumab and infliximab) that cover a range of similarity/disimilarity in a middle-up approach. The second dimension RP separations are coupled to time-of-flight mass spectrometry, which enables direct identification of features in the chromatograms obtained from mAbs digested with the IdeS enzyme, or digestion with IdeS followed by reduction with dithiothreitol. As many as 23 chemically unique mAb fragments were detected in a single sample. Our results demonstrate that these rich datasets enable facile assesment of the degree of similarity between reference and biosimilar materials.     

Chromatin methylation activity of Dnmt3a and Dnmt3a/3L is guided by interaction of the ADD domain with the histone H3 tail

Using peptide arrays and binding to native histone proteins, we show that the ADD domain of Dnmt3a specifically interacts with the H3 histone 1–19 tail. Binding is disrupted by di- and trimethylation of K4, phosphorylation of T3, S10 or T11 and acetylation of K4. We did not observe binding to the H4 1–19 tail. The ADD domain of Dnmt3b shows the same binding specificity, suggesting that the distinct biological functions of both enzymes are not related to their ADD domains. To establish a functional role of the ADD domain binding to unmodified H3 tails, we analyzed the DNA methylation of in vitro reconstituted chromatin with Dnmt3a2, the Dnmt3a2/Dnmt3L complex, and the catalytic domain of Dnmt3a. All Dnmt3a complexes preferentially methylated linker DNA regions. Chromatin substrates with unmodified H3 tail or with H3K9me3 modification were methylated more efficiently by full-length Dnmt3a and full-length Dnmt3a/3L complexes than chromatin trimethylated at H3K4. In contrast, the catalytic domain of Dnmt3a was not affected by the H3K4me3 modification. These results demonstrate that the binding of the ADD domain to H3 tails unmethylated at K4 leads to the preferential methylation of DNA bound to chromatin with this modification state. Our in vitro results recapitulate DNA methylation patterns observed in genome-wide DNA methylation studies.     

Convergent evolution of seed dispersal by ants,and phylogeny and biogeography in flowering plants: A global survey

Seed dispersal is a fundamental life history trait in plants. Although the recent surge of interest in seed dispersal by ants (myrmecochory) has added greatly to knowledge on the ecology of seed dispersal and ant–plant mutualisms, myrmecochory also represents a unique opportunity to examine the links between seed dispersal and evolution in flowering plants. Here we review the taxonomic, phylogenetic and biogeographic distribution of myrmecochory in flowering plants. Myrmecochory is mediated by elaiosomes, i.e., lipid-rich seed appendages that attract ants and serve as rewards for dispersal. We surveyed the literature for evidence of elaiosomes in angiosperm plants to estimate the global prevalence of myrmecochory. We then searched the literature for phylogenetic reconstructions to identify myrmecochorous lineages and to estimate the minimum number of independent evolutionary origins of myrmecochory. We found that myrmecochory is present in at least 11 000 species or 4.5% of all species, in 334 genera or 2.5% of all genera and in 77 families or 17% of all families of angiosperm plants. We identified at least 101, but possibly up to 147, independent origins of myrmecochory. We estimated three or more origins in 13 families and found that at least half the genera are myrmecochorous in 10 families. Most myrmecochorous lineages were Australian, South African or northern temperate (Holarctic). A mapping of families containing myrmecochorous genera on a dated angiosperm supertree showed that myrmecochory has evolved in most of the major angiosperm lineages and that it is more frequent in younger families (crown group age <80 million years) than in older ones. We suggest that the relatively low physiological and energetic costs of producing an elaiosome and the consistent selective benefits of myrmecochory (dispersal, protection from seed predators and fire, safe and nutrient-rich microsites) explain the numerous evolutionary and developmental origins of myrmecochory in angiosperm plants, and we propose that elaiosomes thus provide one of the most dramatic examples of convergent evolution in biology.