Polyplex-embedding in polyelectrolyte multilayers for gene delivery

In this work, incorporation of plasmid DNA, pre-complexed with PEI, into polyelectrolyte multilayers has been studied to further develop platforms for local gene delivery. Polyplex embedding in synthetic and naturally degradable architectures was efficient for transfection of human hepato-cellular carcinoma cells.     

VEGF-C attenuates renal damage in salt-sensitive hypertension

Salt-sensitive hypertension is a major risk factor for renal impairment leading to chronic kidney disease. High-salt diet leads to hypertonic skin interstitial volume retention enhancing the activation of the tonicity-responsive enhancer-binding protein (TonEBP) within macrophages leading to vascular endothelial growth factor C (VEGF-C) secretion and NOS3 modulation. This promotes skin lymphangiogenesis and blood pressure regulation. Whether VEGF-C administration enhances renal and skin lymphangiogenesis and attenuates renal damage in salt-sensitive hypertension remains to be elucidated. Hypertension was induced in BALB/c mice by a high-salt diet. VEGF-C was administered subcutaneously to high-salt-treated mice as well as control animals. Analyses of kidney injury, inflammation, fibrosis, and biochemical markers were performed in vivo. VEGF-C reduced plasma inflammatory markers in salt-treated mice. In addition, VEGF-C exhibited a renal anti-inflammatory effect with the induction of macrophage M2 phenotype, followed by reductions in interstitial fibrosis. Antioxidant enzymes within the kidney as well as urinary RNA/DNA damage markers were all revelatory of abolished oxidative stress under VEGF-C. Furthermore, VEGF-C decreased the urinary albumin/creatinine ratio and blood pressure as well as glomerular and tubular damages. These improvements were associated with enhanced TonEBP, NOS3, and lymphangiogenesis within the kidney and skin. Our data show that VEGF-C administration plays a major role in preserving renal histology and reducing blood pressure. VEGF-C might constitute an interesting potential therapeutic target for improving renal remodeling in salt-sensitive hypertension.     

The study of a French family with two duplicated C4A haplotypes

Summary The finding of two duplicated C4A haplotypes in a normal French family led to a detailed study of their C4 polymorphism. The father had an extremely rare A^*6A^*11, B^* QO haplotype inherited by all of his children and the mother had the more common A^*3A^*2, B^*QO haplotype. Two HLA identical daughters only have four C4A alleles. The father's A11 allotype expresses Ch: 1 (Chido) rather than Rg:1 (Rodgers) and represents a new Ch phenotype Ch: 1,-2,-3,-4,-5,-6. In order to clarify the genetic background in this unusual family, DNA studies of restriction fragment length polymorphisms (RFLPs) were undertake. The father's rare haplotype, which expresses two C4A allotypes, results from a long and a short C4 gene normally associated with the A^*6, B^*1 that also exhibits the BglII RFLP. As it travels in an extended MHC haplotype HLA A2, B57 (17), C2^*C, BF^*S, DR7 that is most frequently associated with A^*6, B^*1, we postulate that the short C4B has been converted in the chain region to a C4A gene which produces a C4A protein. This report of a short C4A gene is the first example in the complex polymorphism of C4.     

Pharmacology of L-660,711 (MK-571): a novel potent and selective leukotriene D4 receptor antagonist

L-660,711 (3-(3-(2-(7-chloro-2-quinolinyl)ethenyl)phenyl) ((3-dimethyl amino-3-oxo propyl)thio)methyl)thio)propanoic acid is a potent and selective competitive inhibitor of [3H]leukotriene D4 binding in guinea pig (Ki value, 0.22 nM) and human (Ki value, 2.1 nM) lung membranes but is essentially inactive versus [3H]leukotriene C4 binding (IC50 value in guinea pig lung, 23 microM). Functionally it competitively antagonized contractions of guinea pig trachea and ileum induced by leukotriene (LT) D4 (respective pA2 values, 9.4 and 10.5) and LTE4 (respective pA2 values, 9.1 and 10.4) and contractions of human trachea induced by LTD4 (pA2 value, 8.5). L-660,711 (5.8 x 10(-8)M) antagonized contractions of guinea pig trachea induced by LTC4 in the absence (dose ratio = 28) but not in the presence of 45 mM L-serine borate (dose ratio less than 2). L-660,711 (1.9 x 10(-5)M) did not block contractions of guinea pig trachea induced by histamine, acetylcholine, 5-hydroxytryptamine, PGF2 alpha, U-44069, or PGD2. In the presence of atropine, mepyramine, and indomethacin, L-660,711 (1.9 x 10(-5)M) inhibited a small component of the response to antigen on guinea pig trachea but completely blocked anti-IgE-induced contractions of human trachea. L-660,711 (i.v.) antagonized bronchoconstriction induced in anesthetized guinea pigs by i.v. LTC4, LTD4, and LTE4 but did not block bronchoconstriction to arachidonic acid, U-44069, 5-hydroxytryptamine, histamine, or acetylcholine. Intraduodenal L-660,711 antagonized LTD4 (0.2-12.8 micrograms/kg)-induced bronchoconstriction in guinea pigs, and p.o. L-660,711 blocked LTD4- and Ascaris-induced bronchoconstriction in conscious squirrel monkeys and ovalbumin-induced bronchoconstriction in conscious sensitized rats treated with methysergide (3 micrograms/kg). The pharmacological profile of L-660,711 indicates that it is a potent, selective, orally active leukotriene receptor antagonist which is well suited to determine the role played by LTD4 and LTE4 in asthma and other pathophysiologic conditions.     

Phosphofructokinase 2 and glycolysis in HT29 human colon adenocarcinoma cell line. Regulation by insulin and phorbol esters.

Kinetic properties of phosphofructokinase 2 (PFK2) and regulation of glycolysis by phorbol 12-myristate 13-acetate (PMA) and insulin were investigated in highly glycolytic HT29 colon cancer cells. PFK2 was found to be inhibited by citrate and, to a lesser extent, by phosphoenolpyruvate and ADP, but to be insensitive to inhibition by sn-glycerol phosphate. From these kinetic data, PFK2 from HT29 cells appears different from the liver form, but resembles somewhat the heart isoenzyme. Fructose 2,6-bisphosphate (Fru-2,6-P2) levels, glucose consumption and lactate production are increased in a dose-dependent manner in HT29 cells treated with PMA or insulin. The increase in Fru-2,6-P2 can be related to an increase in the Vmax. of PFK2, persisting after the enzyme has been precipitated with poly(ethylene glycol), without change in the Km for fructose 6-phosphate. The most striking effects of PMA and insulin on Fru-2,6-P2 production are observed after long-term treatment (24 h) and are abolished by actinomycin, cycloheximide and puromycin, suggesting that protein synthesis is involved. Furthermore, the effects of insulin and PMA on glucose consumption, lactate production, Fru-2,6-P2 levels and PFK2 activity are additive, and the effect of insulin on Fru-2,6-P2 production is not altered by pre-treatment of the cells with the phorbol ester. This suggests that these effects are exerted by separate mechanisms.     

Antigenic determinants expressed by human C4 allotypes; a study of 325 families provides evidence for the structural antigenic model

The antigenic determinants of human C4 have been defined by human IgG antisera, Rodgers (Rg) and Chido (Ch), in hemagglutination-inhibition assays (HAI). Eight (2 Rg and 6 Ch) are of high frequency, > 90% , and 1, WH, is of low frequency, 15 %. The phenotypic combinations are complex; generally, C4A expresses Rg, and C4B has Ch, but reverse antigenicities have been established both by HAI and by sequence data of selected C4 allotypes. A study of 325 families provides data on the antigenic expression of each C4 allotype and demonstrates strong associations. A structural model for the antigenic determinants of C4 proteins has been proposed and is completely supported by the family material. Of the 16 possible antigenic combinations for C4 proteins, only 3 are undetected. A new Ch combination has been recorded in two French families. The reported sequence variation within the C4d region can account for the antigenic determinants but leaves the location of electrophoretic variation in C4 still unclear.     

Conversion of cyanide to formate and ammonia by a pseudomonad obtained from industrial wastewater

Summary A cyanide-degrading pseudomonad was isolated by selective enrichment in a chemostat inoculated with coke-plant activated sludge and maintained at a dilution rate of 0.042/h for 60 days with a feed of 10 mg/l cyanide. The isolate, a facultative methylotroph capable of growth on methanol and methylamine, degraded cyanide to formate and ammonia; it could utilize the released ammonia as a nitrogen source but did not further metabolize formate under the experimental conditions employed. Both cyanide-degrading enzyme activity and respiratory resistance to cyanide were inducible and were enhanced by repeated exposure to the compound. Cell-free extracts stoichiometrically converted cyanide to formate and ammonia in a reaction that did not require oxygen. Enzyme activity, lost upon dialysis, was restored by less than equimolar ratios of NAD(P)H or ascorbate to cyanide, indicating that the reductants did not function directly as co-enzymes.     

Antifreeze protein pseudogenes.

Three members, 11-3, F2 and 5a, of the type-I antifreeze protein (AFP) multigene family in winter flounder were sequenced. All three belong to the subset of AFP genes that are linked, but irregularly spaced, and show significant differences from the functional genes in tandem repeats. 11-3 and F2 appear to be pseudogenes. Their intron, 3'-exon and 3'-flanking DNAs are similar to those of other AFP genes, but their 5'-exon is either missing or extensively modified, and has stop codons present in all three reading frames. Based on a comparison of intron sequences of family members, 11-3/F2 may represent a residual progenitor AFP gene which was duplicated after reaching pseudogene status. The third gene, 5a, is remarkable in having a 3'-exon that encodes an exceptionally long, Ala-rich sequence that lacks any semblance of the 11-amino acid repeats found in 11-3, F2 and functional AFP genes. 5a might also be a pseudogene, because its presumed TATA box appears to have mutated.