Cumulative superinduction of avidin in the chick oviduct by tissue damage and actinomycin D

Avidin expression during chick chondrocyte and myoblast development in vitro and in vivo: regulation of cell proliferation

Avidin is a major [(35)S]methionine-labeled protein induced by bacterial lipopolysaccharide (LPS) and interleukin 6 (IL-6) in cultured chick embryo myoblasts and chondrocytes. It was identified by N-terminal sequencing of the protein purified from conditioned culture medium of LPS-stimulated myoblasts. In addition, avidin was secreted by unstimulated myoblasts and chondrocytes during in vitro differentiation; maximal expression being observed in differentiated myofibers and hypertrophic chondrocytes. In developing chick embryos, immunohistochemistry revealed avidin in skeletal muscles and growth plate hypertrophic cartilage. Avidin was secreted into culture as a biologically active tetramer. Exogenous avidin added to the medium of proliferating chondrocytes progressively inhibited cell proliferation, whereas addition of avidin to differentiating chondrocytes in suspension allowed full cell differentiation. No toxic effects for the cells were observed in both culture conditions. Western blots of samples from cytosolic extracts using alkaline-phosphatase-conjugated streptavidin showed three biotin-containing proteins. Acetyl-CoA carboxylase was identified by specific antibodies. Based on these data, we propose that avidin binds extracellular biotin and regulates cell proliferation by interfering with fatty acid biosynthesis during terminal cell differentiation and/or in response to inflammatory stimuli.

Molecular cloning and nucleotide sequence of chicken avidin-related genes 1-5

Using avidin cDNA as a hybridisation probe, we detected a gene family whose putative products are related to the chicken egg-white avidin. Two overlapping genomic clones were found to contain five genes (avidin-related genes 1-5, avr1-avr5), which have been cloned, characterized and sequenced. All of the genes have a four-exon structure with an overall identity with the avidin cDNA of 88-92%. The genes appear to have no pseudogenic features and, in fact, two of these genes have been shown to be transcribed. The putative proteins share a sequence identity of 68-78% with avidin. The amino acid residues responsible for the biotin-binding activity of avidin and the bacterial biotin-binding protein, streptavidin, are highly conserved. Since avidin is induced in both a progesterone-specific manner and in connection with inflammation, these genes offer a valuable tool to study complex gene regulation in vivo.

Progesterone stimulates prostaglandin synthesis in eggshell gland mucosa of estrogen-primed chickens

1. Prostaglandins may be involved in calcium translocation in the avian shell gland, since indomethacin, administered at the beginning of shell formation, reduces eggshell thickness as well as 45Ca-uptake and prostaglandin synthesis by a homogenate of eggshell gland mucosa. 2. The stimulus for calcium transport in the shell gland during shell formation remains unknown. 3. The present study was undertaken to investigate the effects of progesterone on prostaglandin formation by the eggshell gland mucosa of the domestic fowl. 4. Progesterone significantly stimulated synthesis of PGF2 alpha, PGE2 and TXB2 by eggshell gland mucosa homogenate. 5. Progesterone treatment also induced the synthesis of the biotin-binding protein, avidin. 6. A microsomal fraction prepared from the eggshell gland mucosa had a high affinity for binding PGE2. 7. Progesterone treatment reduced the KD value of this binding without affecting the maximal number of binding sites. 8. Progesterone did not change the total calcium content of shell gland mucosa. 9. The role progesterone plays in prostaglandin formation and calcium transport in the eggshell gland mucosa is discussed.

The distribution of calmodulin in the mucosa of the avian oviduct and the effect of p-p'-DDE on some of its metabolic parameters

1. Since calmodulin or some closely related peptide may activate the Ca2(+)-transporting system in the avian eggshell gland, the calmodulin content in different parts of the oviduct mucosa was determined in egg-laying birds killed at 1600 hr. 2. The highest content was noted in the shell gland mucosa both in egg-laying ducks and hens. The calmodulin content was high even in the isthmus part, where the shell formation begins. 3. Treatment of ducks (Indian runner variety) with DDE (40 ppm for 45 days) did not influence the calmodulin content of the shell gland, however. 4. The content of the protein avidin, the formation of which is stimulated by progesterone, was increased significantly in the oviduct. The carbanhydrase activity did not change significantly. 5. The dry weight of the shell gland was reduced by DDE administration in ducks but not in domestic fowls. 6. These and earlier observations indicate that DDE can act as an partial agonist which is able both to stimulate and to inhibit reactions in the shell gland and other parts of the oviduct. 7. In vivo DDE in the dose used probably acted on higher centres, influencing the activity of the shell gland and probably other parts of the oviduct. 8. A regulation centre which influences several sexual functions is the hypothalamic-hypophyseal region, but the endocrine function of the ovary has also been considered.

Molecular cloning of the chicken avidin cDNA

A cDNA for chicken avidin was identified in a chicken oviduct cDNA library by screening with antibodies and synthetic oligodeoxyribonucleotides. Four recombinant clones were characterized and each contained the sequence of the oligonucleotide probes used in screening. They were capable also of expressing an antigen recognizable by a polyclonal or a mixture of monoclonal antibodies raised against avidin. The longest clone, lambda cAV4, contained the entire coding sequence of avidin along with a signal peptide of 24 amino acids. An avidin mRNA, approximately 700 nucleotides in length, was induced by a single injection of progesterone over a period of twenty four hours. The avidin mRNA was distributed in a tissue-specific manner, since detectable concentration of the mRNA appeared only in the oviduct after stimulation with progesterone alone or with a combination of progesterone and estrogen. No avidin mRNA was detected in the liver or kidney under these conditions. Preliminary results on the genomic complexity of avidin suggest a single copy gene. Isolation of the natural gene for avidin and studies on its regulation now can be initiated using the cDNA probe.

Production of monoclonal antibodies against avidin

Monoclonal antibodies of the IgG1 subclass were generated against chicken avidin. These antibodies were shown to be as sensitive as polyclonal antiserum in detecting avidin by radioimmunoassay (RIA) and enzyme linked immunosorbent assay (ELISA) methods. Furthermore, the monoclonal antibodies were considerably more specific. Our results with a monoclonal anti-avidin RIA support previous findings that in inflammatory conditions avidin is synthesized also in other organs than the oviduct, although in the liver a major part of the activity detected by polyclonal anti-avidin RIA or biotin-bentonite assay was not due to avidin.

The occurrence and production of avidin: a new conception of the high-affinity biotin-binding protein

The production of avidin, a high-affinity biotin-binding egg-white protein, is not restricted to the avian, amphibian and reptilian oviducts. In the acute phase of inflammation, avidin is synthesized and secreted by various injured tissues in the domestic fowl, both male and female. Also in other avian species and a lizard, injured tissues produce an avidin-like biotin-binding factor. The non-oviductal production of avidin in domestic fowl has a great variety of inducers, for example acute inflammation caused by mechanical or thermal tissue injury, septic bacterial infection and (toxic) drugs, and even retrovirus-induced cell transformation. In culture, chicken embryo fibroblasts and yolk sac macrophages synthesize and secrete avidin. Besides the albumen, avidin may act as an antibacterial protein also in the tissues.

Similarity of biotin-binding activity and immunoreactivity in chicken oviduct and non-oviduct avidin

Biotin-binding and immunological methods were employed to demonstrate the similarity of oviduct and non-oviduct avidin in the chicken. Oviduct avidin was induced after oestrogen pretreatment by progesterone and non-oviduct avidin by intestinal tissue injury or by intraperitoneal actinomycin D administration. Avidin in the intestine, lung, bursa of Fabricius, plasma, pectoral muscle and liver after injury had biotin-binding activity similar to that of progesterone-induced oviduct avidin: (1) a temperature of 79-83 degree C was required for 50% of the maximum [14C]biotin uptake, (2) maximal exchange occurred only at 90 or 100 degree C and (3) denaturation of protein, i.e., loss of biotin-binding activity, was not yet observed at 100 degree C. Avidin in the intestine, lung, bursa of Fabricius, plasma and pectoral muscle also showed an identical cross-reaction with oviduct avidin. Furthermore, the increase in avidin-like biotin binding in the oviduct and most non-oviduct tissues was significantly correlated with the increase in avidin-like antigen in the tissue. This indicates that avidin induced in chicken non-oviduct tissues by injury or inflammation caused by actinomycin D administration is similar to progesterone-dependent oviduct avidin.

Avidin induction by tissue injury and inflammation in male and female chickens

1. The occurrence and inducibility of the biotin-binding egg white protein (avidin) in the chicken is not restricted to the oviduct. 2. Inflammatory treatments (intestinal injury, actinomycin D) induced avidin in a number of tissues of young and adult hens and roosters, but not of female rats and mice. Highest avidin concentrations were found in the organs containing epithelial cells and serous membrane. 3. The expression of the avidin gene by tissue injury and inflammation suggests that avidin has a significant function in the injured and inflamed chicken tissues.

A radioimmunoassay for chicken avidin. Comparison with a [14C]biotin-binding method

A double-antibody solid-phase radioimmunoassay for chicken avidin is reported. Avidin was labelled with 125I by the chloramine-T method. The bound and free avidin were separated with a second antibody bound to a solid matrix. In the logit-log scale the standard curve was linear from 1-2 to 100-200ng of avidin/ml. Cross-reaction of ovalbumin was less than 0.015%. Saturation of biotin-binding sites of avidin with an excess of biotin decreased radioimmunoassay values by about 15%. Recovery studies indicated that avidin can be assayed from all chicken tissues studied with radioimmunoassay, whereas the [14C]biotin/bentonite method gave poor recoveries for avidin in the liver and kidney. Radioimmunoassay and the [14C]biotin/bentonite method gave similar concentrations for oviduct avidin.

Induction of ovalbumin synthesis in immature chicks by actinomycin D and thioacetamide

Actinomycin D and thioacetamide induced ovalbumin synthesis and increased serum progesterone concentrations in immature chicks. The increase in progesterone induced by the carcinogens actinomycin D and thioacetamide may account for the induction of ovalbumin synthesis.

Induction of avidin in the chick oviduct by tissue damage. Effect of promethazine chloride, CaCl2 and hydrocortisone on local induction

The local effect of the mechanical induction of avidin by ligature was studied in diethylstilbestrol-primed chicks. The highest induction of avidin was always found in the immediate vicinity of the silk ligature of the oviduct. The locality of the induction was highly dependent on the position of the ligature. The nonligated parts of the ligated oviduct also showed a slight avidin induction. These results indicate a strictly local effect of avidin induction by ligature. An antihistamine, promethazine chloride, has a potentiating effect on the avidin induction by ligature when administered after the ligature. On the other hand, membrane stabilization by hydrocortisone or CaCl2 did not influence the ligature-induced avidin synthesis. On the basis of these results it is concluded that the avidin induction is not mediated by histamine activation or membrane damage.

Immunofluorescence demonstration of avidin in the immature chick oviduct epithelium after progesterone

Immature chicks were used for the experiments 1-2 days after hatching. A group of chicks were injected with 5 mg of progesterone and sacrificed 1 or 24 hr later. An other group of chicks were injected daily for 9 days with 5 mg of diethylstilbestrol and thereafter with single injection of progesterone. Cryostat sections were incubated with rabbit anti-avidin serum and with fluorescein labelled antirabbit globulin for fluorescence histochemistry. In the control animals no epithelial cells of the oviduct were fluorescence positive independently whether or not the animals were pretreated with diethylstilbestrol. One hour after administration of progesterone epithelial cells showed occasionally a slight synthesis of avidin. 24 hours after the injection of progesterone most, however never all, of the epithelial cells showed avidin in the apical part of the cell. The fluorescence reaction was clearly more intense if the animals were estrogen-primed. Diethylstilbestrol caused a differentiation of oviductal glands which were, however, only occasionally avidin positive after progesterone. These results suggest that primitive oviductal cells can produce avidin without preceding differentiation whereas estrogen causes a differentiation of new line of cells which have regularly lost their capacity of avidin synthesis after progesterone administration.