Associations of umbilical cord fatty acid profiles and desaturase enzyme indices with birth weight for gestational age in Japanese infants.

Long-chain polyunsaturated fatty acids (LCPUFAs) required for infant development are produced by Δ6 desaturase (D6D) and Δ5 desaturase (D5D). The D6D index and D5D index are calculated based on their respective precursor/product ratios. The D5D and D6D indices are related to obesity and lifestyle-related diseases. The aim of the present study was to examine the associations of umbilical cord fatty acid profiles, D6D index, and D5D index in appropriate for gestational age (AGA), small for gestational age (SGA), and large for gestational age (LGA) infants. This was a nested case-control study, and the relationship between case and control maternal blood and umbilical cord blood fatty acid compositions was examined. Cases were small for gestational age (SGA; n = 55) and large for gestational age (LGA; n = 149) infants, whereas controls were appropriate for gestational age (AGA; n = 204) infants. Fatty acid profiles in maternal blood and umbilical cord plasma were analyzed by gas-liquid chromatography. The D6D index was calculated as dihomo-γ-linolenic acid (DGLA 20: 3 n-6) / linoleic acid (18: 2 n - 6), and the D5D index was calculated as arachidonic acid (20: 4 n - 6) / DGLA (20: 3 n - 6). Statistical analysis of umbilical cord blood fatty acids was performed with multiple comparisons. SGA infants showed high umbilical cord values for α-linolenic acid and DHA and lower values for DGLA compared to AGA infants. SGA infants showed a higher D5D index but a lower D6D index than AGA infants. LGA infants showed high values for α-linolenic acid and DGLA and lower values for arachidonic acid than AGA infants. LGA infants showed a high D6D index and a low D5D index relative to AGA infants. No significant differences in maternal blood fatty acid profiles, the D6D index, and D5D index desaturase activities were found among the three groups. There were differences in umbilical cord fatty acid profiles and D6D and D5D indices among AGA, SGA, and LGA infants, but further study is needed.

Cell surface changes that advance the application of using yeast as a food emulsifier.

A previous study revealed that Saccharomyces cerevisiae mcd4Δ, a cell wall mutant with a defect in the synthesis of the glycosylphosphatidylinositol anchor, has a strong macrophage activation ability. In this study, remarkable emulsion formation after cell suspensions of mcd4Δ and anp1Δ (which exhibit an extreme reduction of mannan) were mixed with oil was found. Moreover, the relationship between cell wall mutation and emulsion formation was investigated, suggesting that och1Δ with a defect in the formation of N-linked glycans also had a strong emulsification ability and that high molecular weight materials released from the cells were involved in emulsion formation. Furthermore, two strains (asc1Δ and scp160Δ) with a strong emulsification ability without a large decrease in mannan content were also found from the wide screening of strains that exhibit an emulsifying activity using more than 5000 gene-deficient strains. These results provide valuable information for the development of a yeast-derived emulsifier.

Interferon-alpha-induced mTOR activation is an anti-hepatitis C virus signal via the phosphatidylinositol 3-kinase-Akt-independent pathway.

OBJECT: The interferon-induced Jak-STAT signal alone is not sufficient to explain all the biological effects of IFN. The PI3-K pathways have emerged as a critical additional component of IFN-induced signaling. This study attempted to clarify that relationship between IFN-induced PI3-K-Akt-mTOR activity and anti-viral action. RESULT: When the human normal hepatocyte derived cell line was treated with rapamycin (rapa) before accretion of IFN-alpha, tyrosine phosphorylation of STAT-1 was diminished. Pretreatment of rapa had an inhibitory effect on the IFN-alpha-induced expression of PKR and p48 in a dose dependent manner. Rapa inhibited the IFN-alpha inducible IFN-stimulated regulatory element luciferase activity in a dose-dependent manner. However, wortmannin, LY294002 and Akt inhibitor did not influence IFN-alpha inducible luciferase activity. To examine the effect of PI3-K-Akt-mTOR on the anti-HCV action of IFN-alpha, the full-length HCV replication system, OR6 cells were used. The pretreatment of rapa attenuated its anti-HCV replication effect in comparison to IFN-alpha alone, whereas the pretreatment with PI3-K inhibitors, wortmannin and LY294002 and Akt inhibitor did not influence IFN-induced anti-HCV replication. CONCLUSION: IFN-induced mTOR activity, independent of PI3K and Akt, is the critical factor for its anti-HCV activity. Jak independent mTOR activity involved STAT-1 phosphorylation and nuclear location, and then PKR is expressed in hepatocytes.

Differential effects of calcineurin inhibitors, tacrolimus and cyclosporin a, on interferon-induced antiviral protein in human hepatocyte cells.

The premise of our study is that selective inhibition of interferon (IFN) by calcineurin inhibitors contribute to the increased severity of hepatitis C virus (HCV) posttransplantation. Therefore, we examined the influence of calcineurin inhibitors in the human hepatocyte cell line on IFN-alpha-induced phosphorylation of Janus kinase (Jak) and signal transducers and activators of transcription (STAT), nuclear translocation of IFN-stimulated gene factor 3 (ISGF-3), IFN-stimulated regulatory element (ISRE)-contained promoter activity, and the expressions of antiviral proteins. Tacrolimus (Tac), but not cyclosporin A (CyA), had an inhibitory effect on IFN-alpha-induced double-stranded ribonucleic acid (RNA)-dependent protein kinase (PKR) in a dose-dependent manner. STAT-1 also acted in a similar fashion to PKR. IFN-alpha combined with Tac attenuated the ISRE-containing promoter gene activity as compared with IFN-alpha alone. In contrast, its expression in pretreated CyA was slightly attenuated. In pretreated Tac, but not CyA, the levels of IFN-alpha-induced tyrosine phosphorylated STAT-1 and -2 were clearly lower than those induced by IFN-alpha alone. Tac and CyA did not decrease the IFN-alpha-induced JAK-1 phosphorylation. The nuclear translocation rate of tyrosine phosphorylated STAT-1 was inhibited by pretreatment of both Tac and CyA by western blotting and immunohistochemistry. In an HCV replicon system, pretreated Tac diminished the replication inhibitory effect of IFN-alpha. In this study, we show that calcineurin inhibitors, especially Tac, are the negative regulators of IFN signaling in the hepatocyte; the greatest cause of such inhibition is the phosphorylation disturbance of STAT-1, next to inhibition of the nuclear translocation of STAT-1. In conclusion, disturbance of tyrosine phosphorylation of STAT-1 resulted in diminished ISRE-containing promoter activity and a decline in antiviral protein expression. Moreover, the replication of HCV was activated. This phenomenon is detrimental to IFN therapy after liver transplantation, and the selection of calcineurin inhibitors may warrant further discussion depending on the transplant situation.