Morphogenetic lung defects of JSAP1-deficient embryos proceeds via the disruptions of the normal expressions of cytoskeletal and chaperone proteins

Recent studies have shown that JNK/stress-activated protein kinase-associated protein 1 (JSAP1)-deficient mice die from respiratory failure shortly after birth. To understand the underlying mechanism, we investigated the histological appearances and cell type changes in developing jsap1(-/-) lungs between E12.5 and E18.5. At the light microscopic level, no overt abnormality was detected in jsap1(-/-) until E16.5. However, alveoli and airway formations that normally occur after E16.5 were poorly advanced in jsap1(-/-). Despite these morphological defects, surfactant secreting cells labeled by anti-SP-B or anti-SP-C were present in normal ranges in jsap1(-/-) lungs. Smooth muscle alpha-actin expressing cells were also developed in jsap1(-/-) lungs, although actin expression was decreased. The expressions of transcriptional factors, such as, nuclear factor Ib (Nfib), N-myc, and octamer transcriptional factor 1 (Oct-1), which play a critical role in lung morphogenesis, were found to be down-regulated, whereas signal transducer and activator of transcription 3 (Stat3), sonic hedgehog (Shh), and smoothened (Smo) were up-regulated, in jsap1(-/-) lungs at E17.5-E18.5 compared with those in jsap1(+/+) lungs. Proteomics analysis of E17.5 lung identified 39 proteins with altered expressions, which included actin, tropomyosin, myosin light chain, vimentin, heat shock protein (Hsp27), and Hsp84. These results suggest that JSAP1 is required for the normal expressions of cytoskeletal and chaperone proteins in the developing lung, and that impaired expressions of these proteins might cause morphogenetic defects observed in jsap1(-/-) lungs.

Maternal dietary ratio of linoleic acid to alpha-linolenic acid affects the passive immunity of hatching chicks

The objective of the current study was to examine the effect of dietary ratio of linoleic acid (LA) to alpha-linolenic acid (LNA) on the humoral immune response in laying hens and further on the passive immunity of their progeny. Thirty-two Single Comb White Leghorn laying hens, 24 wk of age, were randomly assigned to 1 of 4 diets that had LA-to-LNA ratios of 0.8, 5.4, 12.5, and 27.7, respectively, by changing the proportions of sunflower and linseed oils. After 5 wk on the experimental diets, hens were immunized intramuscularly with 1 mg of BSA, followed by 2 boosters 2 and 6 wk later. Serum and egg yolk were obtained weekly from 0 to 6 wk following the first injection of BSA. One week after the second booster, fertile eggs were collected and incubated. The sera of 11-d-old embryos and hatchlings were collected. All serum samples were stored at -20 degrees C before analysis. The results showed that dietary LA-to-LNA ratio had no effect on the total IgG and BSA-specific antibody IgG concentrations in the serum or egg yolk of laying hens. Hatchlings from hens fed the diet containing the LA-to-LNA ratio of 12.4 showed lower (P < 0.05) BSA-specific IgG titer in the serum than those from hens given the diet containing LA-to-LNA ratio of 0.8. A lower (P < 0.05) total IgG concentration was observed in hatchlings from hens fed the diet containing LA-to-LNA ratio of 12.4 compared with those from hens fed diets containing 0.8 and 5.4 of LA-to-LNA ratios. It is suggested that the dietary ratio of LA to LNA has no effect on laying hen humoral response but affects the passive immunity of hatching chicks.

Maternal diet with diverse omega-6/omega-3 ratio affects the brain docosahexaenoic acid content of growing chickens

Eggs with diverse omega-6/omega-3 ratio produced by feeding breeder hens a wheat-soybean meal-basal diet containing 5% (wt/wt) sunflower oil (H(omega)6), 5% fish oil (H(omega)3) or 2.5% sunflower oil plus 2.5% fish oil (M(omega)3omega6) were incubated. The hatched chicks were fed a docosahexaenoic acid (DHA)-deficient diet up to 6 weeks of age. The fatty acid composition of chick brain was determined on 0, 2, 4 and 6 weeks and brain weight was taken on day 0 and day 42. The omega-6/omega-3 ratios were 37.12, 4.21 and 0.98 for the maternal diet; 28.36, 2.83 and 0.89 for the egg yolk; 1.94, 0.48 and 0.18 for hatched chick brain (p < 0.05). At 2 weeks of age, the omega-6/omega-3 ratios were 1.88, 0.81 and 0.60 for chicks hatched from hens fed H(omega)6, M(omega)3omega6 and H(omega)3 diets, respectively. The brain DHA contents at 0 and 2 weeks of age were Homega3 > M(omega)3omega6 < H(omega)6 (p < 0.05) and at 4 and 6 weeks of age H(omega)3 = M(omega)3omega6 > H(omega)6. Dietary C18:3omega3 in the starter and finisher diet did not increase brain DHA (p > 0.05). The significant increase in the content of C22:5omega3 at 6 weeks of age in group 1 birds with a concomitant reduction in DHA suggests a weak delta-4 desaturation but an effective delta-6 and delta-5 desaturation similar to human infants. Considering the role of DHA in early brain development and growth, the maternal supply of DHA during growth might be of importance when fed a DHA-deficient neonatal diet.

Maternal dietary FA modulate the long-chain n−3 PUFA status of chick cardiac tissue

The effect that egg yolk or maternal n-3 FA have on the cardiac tissue long-chain n-3 FA status of chicks during growth was investigated. Eggs with low, medium, and high levels of n-3 PUFA were obtained by feeding breeder hens a wheat/soybean meal-based diet containing 5% sunflower oil (Low n-3), 2.5% sunflower oil plus 2.5% fish oil (Medium n-3), or 5% fish oil (High n-3). The chicks hatched from Low, Medium, and High n-3 eggs were fed a diet containing 18:3n-3, but devoid of long-chain n-3 FA. The FA composition of cardiac tissue was determined on days 0, 14, 28, and 42. At day 0, the cardiac FA reflected maternal diet. With time, the level of all the long-chain n-3 FA decreased compared with day 0, and this was true especially by day 14. These data show that dietary 18:3n-3 fed to the chicks did not sustain high levels of EPA and DHA in cardiac tissue, despite the high content of long-chain n-3 FA in the maternal diet. At days 0 and 14, the chicks hatched from High and Medium n-3 eggs had higher 20:5n-3, 22:5n-3, and 22:6n-3 contents with a concomitant reduction in 20:4n-6 in the cardiac tissue compared with the Low n-3 egg group. Cardiac tissue of birds hatched from Medium n-3 eggs retained higher levels of 20:5n-3 up to day 42 of growth when compared with other treatments (P < 0.05). None of the treatments was effective in maintaining DHA levels after day 14 of growth.

Fatty acid determination in chicken egg yolk: a comparison of different methods

Four different methods (direct-methylation, saponification, chloroform-methanol extraction, and postextraction saponification) were compared to determine the fatty acids in egg yolk. About 50 mg of pooled egg yolk samples, with C23:0 as an internal standard, was used for all assays. No difference (P > 0.05) was observed among the four methods for C17:0, C18:0, C18:1, C20:1, C18:2n-6, and C22:6n-3 content of egg yolk. Direct saponification resulted in a lower (P < 0.05) content of C14:0, C16:1, C18:3n-3, and C20:4n-6. Fatty acids at less than 0.5%, such as C15:0 and C14:1, were not detectable in the direct saponification method. The total saturated, monounsaturated, or polyunsaturated fatty acids did not differ (P > 0.05) among the four methods. Direct methylation of egg yolk resulted in lower variability than other methods and is fast and economic for determining egg fatty acid composition.

Production of chicken egg yolk antibody (IgY) against bovine proteoglycan

This study was undertaken to examine the immune response of chickens to bovine decorin, which is a proteoglycan bearing a single chain of dermatan sulphate. Three 35-wk-old Single Comb White Leghorn hens were immunized with decorin by intramuscular injection, and eggs produced by each bird were examined by ELISA for anti-decorin antibody activity in the yolk. The antibody activity started to increase 7 d after immunization, rapidly increased and remained relatively constant after 35 d. The polyclonal antibody obtained was then examined by ELISA inhibition assay with samples of bovine decorin treated with and without enzymes. Digestion of decorin with papain to cleave its protein core caused a complete loss in antigenicity, while chondroitinase-ABC treatment to cleave its dermatan sulphate chain showed no appreciable effect. This indicates that the protein core but not the dermatan sulphate chain was recognized by the anti-decorin antibodies. Immunohistochemical staining located the antigen in bovine, porcine and chicken tissues. It is concluded that chickens can efficiently produce specific antibodies to the protein core of bovine decorin. Key words: Chicken, proteoglycan, decorin, antibody, immune response