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Biomedical subjects

F Gros

Publications and source records attributed to F Gros.

At least 127 records · Page 7Linked to original sources
PubMed1982

Tissue-specific binding of total and beta-globin genomic deoxyribonucleic acid to non-histone chromosomal proteins from mouse erythropoietic cells.

The synthesis and DNA binding activity of purified nuclear non-histone proteins from mouse erythroblasts and myoblasts have been compared by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, affinity chromatography, and protein blotting. The labeled non-histone proteins bound to mouse total DNA clearly differ between erythroid and muscle cell lines, but these differences mainly reflect the qualitative changes observed in their pattern of synthesis. By contrast, a cloned genomic mouse beta-globin DNA fragment binds specifically several proteins (100K, 65K, 50K, 45K, and 34K) from erythropoietic Friend cells and does not bind any protein in the corresponding fraction from myoblasts. The specificity of these DNA protein interactions requires a NaCl concentration of 0.1 M and a low protein/DNA ratio. In these conditions lambda DNA binds the above proteins to only a small extent. During the dimethyl sulfoxide induced terminal differentiation of Friend mouse erythroleukemia (MEL) cells, there is an apparent overall decrease of total as well as globin DNA binding to the nuclear non-histone proteins but not to the histones, whereas no significant qualitative changes are detected.

Animals↗
PubMed1982

Changes in tropomyosin during development of chick embryonic skeletal muscles in vivo and during differentiation of chick muscle cells in vitro.

We have studied the changes in tropomyosin subunits and their pattern of phosphorylation during embryonic development and also during in vitro differentiation of cultured muscle cells. We have found that in 10-day-old embryos tropomyosin consists of 75% beta subunit and 25% alpha subunit. However, only 60% of the beta subunit is phosphorylated while the alpha subunit is almost exclusively present in its phosphorylated form. During subsequent development, the amount of alpha-tropomyosin increases so that by hatching it represents 50% of the total subunits. During the same time, the amount of phosphorylated variants for both the alpha and the beta subunits decreases so that after hatching they represent less than 20% of each subunit. In cultures of differentiating myoblasts, the alpha subunit is synthesized before the beta subunit, and within each subunit, the unphosphorylated variants are the first to be synthesized. The reason for this discrepancy is not known at the present time.

Animals↗
PubMed1982

Changes in some cytoskeletal proteins during neuroblastoma cell differentiation.

After in vitro microtubule assembly of mouse neuroblastoma crude extracts, six protein species migrate in the tubulin region of two-dimensional electrophoregrams. The evolution of these forms after morphological cell differentiation of the clone NIE115 shows two major modifications. Form 5 decreased drastically while form 6 increases during neurite formation. Peptide mapping analysis reveals that forms 5 and 6 are vimentin, a component of intermediate filaments, and beta-tubulin subunit, respectively. Sodium butyrate treatment of NIE115 cells or serum starvation of NIA103 cells, conditions blocking cell division and failing to induce morphological differentiation, prevent any modifications in the relative proportion of these proteins. It is concluded that the changes in the distribution of the tubulin isoforms and vimentin are directly related to neurite formation.

Animals↗
PubMed1982

Evolution of tubulin heterogeneity during mouse brain development.

In this report, we have characterized tubulin subunit heterogeneity and its evolution during mouse brain development, from embryonic to adult stages. A modification of the two-dimensional protein analysis was used to specify these events. The number of isotubulins increases from 6 (4 alpha and 2 beta), in the embryonic brain, to 11 (6 alpha and 5 beta), in the adult. The changes occurring in tubulin heterogeneity are developmentally controlled but it seems that alpha and beta isotubulins are independently regulated: changes in alpha tubulin occur only just before birth whereas the major evolution is concerned with the appearance and accumulation of acidic beta isotubulins throughout development.

Aging↗
PubMed1982

cDNA recombinant plasmid complementary to mRNAs for light chains 1 and 3 of mouse skeletal muscle myosin.

A recombinant plasmid with a cDNA sequence transcribed from mouse skeletal muscle RNA is shown to hybridize with mRNAs for myosin light chains LC1F and LC3F. The inserted fragment corresponds exclusively to the 3'-noncoding region of the mRNA. It hybridizes almost exclusively with the two light chain messengers from fast skeletal muscle RNA of adult mouse. Slight hybridization is seen with RNA from heart muscle and embryonic skeletal muscle. The implications of the conservation of the 3'-noncoding regions between the two mRNAs are discussed.

Animals↗
PubMed1982

In vitro cytotoxic properties of plasma samples from uremic patients.

The effect of uremic plasma on the growth of cultured cells was compared to that of control and of nonuremic plasma. Multiplication of D98 and 3T3 cells was measured by cell counting and by 3H-Thymidine incorporation. Uremic plasma was taken from severely uremic children (plasma creat. greater than 0.45 mM) and from hemodialyzed (HD) patients; plasma samples from HD patients were obtained at the beginning and the end of dialysis sessions. The 3H-Thymidine incorporation in the presence of uremic plasma (3665 +/- 520 cpm, n - 23) was lower than in the presence of control plasma (7700 +/- 1.080 cpm, n = 14) (P less than 0.01). The rate of 3H-Thymidine incorporation decreased regularly in the presence of increasing amounts of uremic plasma. 3H-Thymidine incorporation in post dialysis plasma was greater than in predialysis plasma (3902 +/- 664 cpm vs 9430 +/- 1540 cpm, n = 8) (P less than 0.01). To investigate the properties of the cytotoxic material, studies were performed with plasma ultrafiltrate (UF) and ultrafiltrate fractions obtained by G-15 Sepadex filtration. Uremic UF and fractions displayed no cytotoxic properties when cultured alone. Preincubation of uremic UF and the "middle molecular" fraction with control plasma restored a cytotoxic effect which, for total ultrafiltrate, was similar to that observed with uremic plasma. Thus, uremic plasma displays cytotoxic properties related to ultrafiltrable molecules which are not cytotoxic by themseleves but which are cytotoxic in the presence of plasma macromolecules.

Cell Division↗
PubMed1982

Correlation between precancerous bronchial metaplasia and cigarette consumption, and preliminary results of retinoid treatment.

Vitamin A and its derivatives, so-called retinoids, can prevent squamous metaplasia induced not only by vitamin A deficiency but also by carcinogenic hydrocarbons. An aromatic retinoid, such as ET1, has been shown to prevent chemically induced papillomas in mice and to amplify certain immunologic reactions. Heavy smokers, 106 volunteers, were submitted to fibrobronchoscopy with bronchial biopsies. An index of metaplasia (IM) was calculated on the basis of microscopical examination of a total of 9,633 sections of 1,010 biopsies. Despite the subjectivity of the estimates of cigarette consumption, this was significantly (P less than 0.02) and positively correlated to the IM. Eighty-five percent of the women had a low IM as compared to only 42% of the men (P less than 0.01), although there was no significant difference in the reported cigarette consumption. Fifty-two subjects had an IM greater than 15% and were given 25 mg ET1 orally daily for 6 months. The bronchoscopy was repeated in 30 patients following completion of the 6-month treatment. The IM was significantly (P less than 0.01) reduced after treatment.

Adult↗
PubMed1981

Length of the polyadenylated sequence in cytoplasmic ribonucleic acid isolated from fetal calf myoblasts differentiating in vitro.

Poly(adenylic acid) [poly(A)] containing cytoplasmic ribonucleic acid (RNA) in differentiating fetal calf myoblasts cultivated in vitro was examined by hybridization with radioactive poly(uridylic acid). The size distribution of the poly(A)-containing RNA after sucrose-gradient centrifugation was similar in cells before and after differentiation. There was no apparent correlation between the length of the poly(A) segment and the change in stability of messenger RNA which occurs on differentiation, nor with the polysomal or nonpolysomal localization of the RNA in the cytoplasm. The average length of the poly(A) segments in cytoplasmic RNA in the steady state was found to be dependent on the size of the RNA: the longer the RNA, the longer the average length of the poly(A) sequence. In contrast, in pulse-labeled RNa, the length of poly(A) is similar in all size classes of RNa.

Animals↗
PubMed1981

Characterization of the tropomyosin present in various chick embryo muscle types and in muscle cells differentiated in vitro.

Tropomyosin, present in various types of chick embryo muscle, has been characterized by two-dimensional gel electrophoresis. In skeletal muscle, it was found that both the alpha and beta subunits exist as two variants, alpha 1, alpha 2 and beta 1, beta 2. The most acidic variants (alpha 2 and beta 2) could be demonstrated to be phosphorylated and, based upon the facts that 1) after phosphatase treatment alpha 2 and beta 2 co-migrate with alpha 1 and beta 1 and 2) in vitro translation of skeletal muscle mRNA produces only alpha 1 and beta 1, we suggest that alpha 2 and beta 2 merely represent the phosphorylated forms of alpha 1 and beta 1. A similar situation is found in differentiated muscle cultures in vitro. In cardiac muscle or in cardiocytes, in culture, the only subunit of tropomyosin which is present (the alpha subunit) is also phosphorylated. However, in smooth muscle, none of the tropomyosin subunits is phosphorylated. The use of various modifications in the second dimension of two-dimensional gel electrophoresis has allowed us to separate completely the alpha subunits of slow and fast muscle tropomyosin and to show that: 1) the cardiac alpha subunit is distinct from either the slow alpha or the fast alpha subunit and 2) in vitro differentiated cells synthesize a tropomyosin which, by co-migration under various conditions, is identical with fast muscle tropomyosin.

Animals↗