Chicken Amniotic Fluid Research Articles

The Unique Features of Proteins Depicting the Chicken Amniotic Fluid

In many amniotes, the amniotic fluid is depicted as a dynamic milieu that participates in the protection of the embryo (cushioning, hydration, and immunity). However, in birds, the protein profile of the amniotic fluid remains unexplored, even though its proteomic signature is predicted to differ compared with that of humans. In fact, unlike humans, chicken amniotic fluid does not collect excretory products and its protein composition strikingly changes at mid-development because of the massive inflow of egg white proteins, which are thereafter swallowed by the embryo to support its growth. Using GeLC-MS/MS and shotgun strategies, we identified 91 nonredundant proteins delineating the chicken amniotic fluid proteome at day 11 of development, before egg white transfer. These proteins were essentially associated with the metabolism of nutrients, immune response and developmental processes. Forty-eight proteins were common to both chicken and human amniotic fluids, including serum albumin, apolipoprotein A1 and alpha-fetoprotein. We further investigated the effective role of chicken amniotic fluid in innate defense and revealed that it exhibits significant antibacterial activity at day 11 of development. This antibacterial potential is drastically enhanced after egg white transfer, presumably due to lysozyme, avian beta-defensin 11, vitelline membrane outer layer protein 1, and beta-microseminoprotein-like as the most likely antibacterial candidates. Interestingly, several proteins recovered in the chicken amniotic fluid prior and after egg white transfer are uniquely found in birds (ovalbumin and related proteins X and Y, avian beta-defensin 11) or oviparous species (vitellogenins 1 and 2, riboflavin-binding protein). This study provides an integrative overview of the chicken amniotic fluid proteome and opens stimulating perspectives in deciphering the role of avian egg-specific proteins in embryonic development, including innate immunity. These proteins may constitute valuable biomarkers for poultry production to detect hazardous situations (stress, infection, etc.), that may negatively affect the development of the chicken embryo.

The Exploration of Beijing Fatty Chicken Amniotic Fluid Stem Cells with Multilineage Potential

The Exploration of Beijing Fatty Chicken Amniotic Fluid Stem Cells with Multilineage Potential

Investigating proteins and proteases composing amniotic and allantoic fluids during chicken embryonic development

In amniotes, the amniotic fluid is a significant contributor to fetal development and health. While numerous studies have been conducted in mammalian amniotic fluid, the composition of amniotic and other extraembryonic fluids in avian egg along with their physiological functions remain largely unexplored. In such a context, our objective was to characterize the chicken amniotic fluid (AmF) and allantoic fluid (AlF) properties, protein composition, and some associated functions from day 8 to day 16 of incubation. SDS-PAGE combined to mass spectrometry analysis revealed common and specific proteins to each fluid, suggesting distinct properties and functions. Indeed, major AlF proteins are mostly "egg yolk" proteins involved in lipid, vitamin metabolisms, and metal ion transport, while major AmF proteins resemble those of albumen. Drastic changes in the AmF protein profiles were observed during incubation, when the albumen transfers from day 12 onwards, while few changes were detected for the AlF protein profile. The decreases in osmolality (from 231 to 183 mOsm/kg) and pH (from 8.26 to 7.26) observed in the AlF during incubation are associated with water and electrolytes reallocation for the embryo needs. In contrast, AmF pH value remained stable (≈7.5). Active proteolytic enzymes have been identified in the 2 fluids using gelatin zymography, followed by mass spectrometry analysis for protease identification. A total of 12 proteases was detected in the AlF, compared to 5 in the AmF. We have shown that AlF concentrates proteolytic enzymes assumed to participate in digestive processes: aminopeptidase N, dipeptidyl peptidase-4, meprin A, and 72kDa type IV collagenase preproprotein. The other proteases identified in both fluids also could have a role in morphogenesis (hepatocyte growth factor activator, suppressor of tumorigenicity 14, astacin-like metalloendopeptidase) and hemostasis (prothrombin and coagulation factor X). Altogether, these data suggest that the roles of chicken AlF and AmF are not merely associated with protection of the embryo and regulation of metabolic disposable wastes, but also they could have more sophisticated roles during embryonic development.

The effect of chick embryo amniotic fluid on sciatic nerve regeneration of rats.

The purpose of this experimental study was to evaluate the effect of chicken amniotic fluid (AF) on a cross section of rat sciatic nerves. Thirty adult male Sprague-Dawley rats weighing 275 to 300 g, were randomized into three groups treated with (1) amniotic fluid or AF (n=10), (2) normal saline or NS (n=10), and (3) sham surgery (n=10). The AF was aspirated from the amniotic cavity of incubating chick embryos at day 14. The sciatic nerve was exposed and sharply transected. Immediate epineurial repair was then performed. AF treated animals were given 2 ml/kg of the chick embryo AF subcutaneously, once daily, five times a week for up to 2 weeks. All animals were evaluated by sciatic functional index (SFI), electrophysiology, histology, and immunohistochemistry at days 28 and 56 after surgery. The SFI difference between AF and NS groups at days 21 and 28 after operation was statistically significant (P<0.05). The number of myelinated fibers in the AF group was significantly greater than that of the NS group at day 28 (P<0.05). At days 28 and 56 after operation, the nerve conduction velocity (NCV) mean of the AF group was faster than that of the NS group, but the difference was not statistically significant (P>0.05). The results of this study demonstrate that chick AF can enhance peripheral nerve regeneration.

Suppression of Natural Killer Cell Activity by Chicken α-Fetoprotein in Japanese Quails&lt;xref ref-type="fn" rid="fn2"&gt;2&lt;/xref&gt;

Spleen cells taken from quails treated with chicken alpha-fetoprotein (Ch-AFP) showed reduced natural killer (NK) activity as did spleen cells taken from quails treated with chicken amniotic fluid (ChAmF) in which the presence of Ch-AFP was demonstrated by a gel precipitation test. The Ch-AFP-induced reduction of NK activity was shown to be mediated by suppressor cells. In addition, Ch-AFP-treated quails developed tumors with shorter latent periods than those of the tumors that developed in untreated quails after inoculation with Rous sarcoma virus, as was true for ChAmF-treated quails.

Activation of Sendai virus infectivity by an enzyme in chicken amniotic fluid.

Sendai virus grown in LLC-MK2 cells is known to have low infectivity, no detectable haemolysing ability and predominantly uncleaved F glycoprotein. Treatment of such virus with chicken amniotic fluid resulted in a 10(3)- to 10(4)-fold increase in infectivity, the development of haemolysing ability, and cleavage of the F glycoprotein. The 'Sendai activating enzyme' (SAE) responsible for these effects required the presence of 1 mM-Ca2+ ions for maximum activity. It was inhibited by phenylmethylsulphonyl fluoride and soybean trypsin inhibitor but was unaffected by sulphydryl-blocking agents. The results of gel filtration tests suggested that the molecular weight of SAE was about 55 000. SAE may be the natural proteolytic activator of Sendai virus in a soluble form.

The role of NK cells in tumor growth assessed by induction of their suppressor cells in Japanese quails.

In Japanese quails treated with chicken amniotic fluid (ChAmF) which had been previously shown to induce suppressor cells to natural killer (NK) cells, tumors appeared with shortened incubation periods after inoculation with Schmidt-Ruppin strain of Rous sarcoma virus (SR-RSV) compared with untreated quails. The tumors in ChAmF-treated quails subsequently grew in a similar pattern to those in untreated quails, whereas by challenging with a lower dose of the virus, enhanced tumor growth was observed as well as earlier onset of tumors in ChAmF-treated quails than in untreated ones. This enhancing effect on tumor growth due to suppression of NK-cell activity was transferred to normal quails with spleen cells obtained from ChAmF-treated quails, since RSV-induced tumors appeared earlier in the recipients of ChAmF-treated spleen cells than in those of untreated spleen cells. These findings show that suppression of NK-cell activity by ChAmF administration rendered quails higher susceptibility to tumor induction by SR-RSV challenge. In other words, NK-cell activity was strongly suggested to contribute to the early protection against tumor growth in the system of Rous sarcoma in Japanese quails.

Induction and characterization of splenic suppressor cells directed to natural killer cells in Japanese quails.

Intravenous inoculation of chicken amniotic fluid (ChAmF) markedly reduced natural killer (NK) cell activity of spleen cells from Japanese quails. The reduction of NK activity was mediated by non-adherent thymus-dependent lymphoid cells which were resistant to treatment with anti-immunoglobulin serum and sensitive to treatment with anti-thymocyte serum in the presence of complement. The suppressing activity was selectively directed to NK cells, since Rous sarcoma virus-specific cytotoxicity or hemagglutinating antibody production against sheep erythrocytes was not suppressed in ChAmF-treated quails. Spleen cells from normal 1-week-old quails had similar characteristics to those from ChAmF-treated 4-week-old quails, lacking NK activity and exhibiting suppressive effect on NK activity, and were also shown to be thymus-dependent. Biological significance of the presence of NK cells and their suppressor cells is discussed in relation to embryonic development and tumor-surveillance mechanism.

Detection of natural killer cells in Japanese quails.

Spleen cells of normal quails exhibited cytotoxicity on normal embryo cells as well as on virus- and chemically transformed cells. Spleen cells responsible for the destruction of target cells were shown to be non-adherent lymphoid cells which lack surface immunoglobulin and are resistant to the treatment with anti-thymocyte serum and complement. Spleen cells of quails which were injected with chicken amniotic fluid (ChAmF) showed no cytotoxic activity. Furthermore, the addition of ChAmF-treated spleen cells abolished the cytotoxic activity of untreated spleen cells. These results indicated the presence of a spleen-cell population in normal quails compatible with mammalian natural killer (NK) cells and the induction of suppressor cells directed to the NK cells by administration of ChAmF.

Action of hydrocortisone on cells in tissue culture.

Summary1. In a medium consisting of chicken plasma and amniotic fluid, growth inhibition by soluble F ale. in concentrations from 200 μg/ml can be demonstrated consistently. 2. When EE is added to the culture medium, growth inhibition occurs only in a higher concentration of soluble F ale. The suggestion that EE contains a principle antagonistic to the inhibitory action of F ale. is discussed. 3. Growth of epithelium from stomach and intestine is not affected by F alc., while growth of fibroblasts is suppressed. 4. Reversibility of the effect of F ale. after its removal from the medium, and its selective inhibitory action on fibroblasts indicate that its inhibitory action in vitro is related to its known action in vivo, in particular to the retardation of regeneration in wounds experimentally produced in animals. 5. Aqueous soluble DOC in similar concentrations has an effect similar to soluble F ale. and cholesterol in suspension has a minimal inhibitory effect on cell growth. This observation differs fro...