Search PubMed⌕ Search

Biomedical subjects

M Huchet

Publications and source records attributed to M Huchet.

At least 37 records · Page 2Linked to original sources
PubMed1987

Extracts of muscle biopsies from patients with spinal muscular atrophies inhibit neurite outgrowth from spinal neurons.

Preparations derived from embryonic and neonatal chick muscle enhance neurite outgrowth when added to cultures of embryonic chick spinal neurons. In the presence of soluble extracts of biopsied muscle from 15 of 20 patients with spinal muscular atrophy (SMA), the in vitro neurite-promoting activity of neonatal chick muscle was inhibited. There was no comparable inhibition using extracts from 20 age-matched pathologic or morphologically normal controls. The neurite-promoting activity in media conditioned by embryonic myotubes was not inhibited by extracts of the SMA group.

Animals↗
PubMed1986

Increase of neurite-promoting activity for spinal neurons in muscles of 'paralysé' mice and tenotomised rats.

Various lines of evidence from in vivo and in vitro experiments suggest that muscle-derived factors may enhance the survival and axonal outgrowth of spinal neurons. Our previous results using cultures of embryonic spinal neurons showed that denervation of skeletal muscle increased levels of a neurite-promoting activity in soluble muscle extracts. Here, two other experimental models in which muscle activity was also lowered were investigated. The mutant mouse 'paralysé' exhibits a spontaneous regression of motor nerve endings, with concomitant paralysis. In 'paralysé' mutant muscle extracts, specific neurite-promoting activity was up to 10-fold higher than in extracts prepared from control littermates. Tenotomy is known to retard the regression of polyneuronal motor innervation in skeletal muscle from neonatal rats. Three days after operation, levels of neurite-promoting activity were increased 2-fold with respect to total protein. These results suggest that skeletal muscle activity might regulate the synthesis of molecules affecting nerve growth.

Age Factors↗
PubMed1986

Immunoblot analysis of circulating antibodies against muscle proteins in amyotrophic lateral sclerosis and other neurologic diseases.

Serum from patients with amyotrophic lateral sclerosis (ALS) was tested by immunoblotting for reactivity against three muscle-derived preparations: denervated chick leg muscle extracts, media conditioned by denervated rat hemidiaphragms, and a human muscle extract. For each preparation, multiple bands were present using serum from all patients and controls, and no band was unique to ALS. Against rat muscle-conditioned medium, bands in the 56,000 (56K) molecular weight range were present to an equal degree in ALS and in controls; in addition, different bands near 56K were recognized by serum from different ALS patients. These results fail to confirm a recent report suggesting that anti-56K reactivity is characteristic of ALS.

Adult↗
PubMed1984

Neurite-promoting activities for embryonic spinal neurons and their developmental changes in the chick.

Spinal motoneurons may depend upon muscle-derived factors for axon outgrowth and stabilization at two principal stages of their development: during the initial invasion of the differentiating muscle masses in the embryo and during the perinatal regression of multiple innervation. Using a bioassay involving the measurement of neurite outgrowth from 4.5-day embryonic chick spinal neurons in dissociated cell culture, neurite-promoting activities were detected both in medium conditioned over embryonic chicken myotubes in vitro (embryonic muscle-conditioned medium) and in soluble extracts of chick leg muscle prepared 3-5 days after hatching (postnatal muscle extract). The molecules responsible for these two activities had physicochemical properties that distinguished them both from each other and from some other reported neurite-promoting factors. The factor in embryonic muscle-conditioned medium, although active on uncoated tissue culture wells, bound with only low affinity to tissue culture plastic under cell culture conditions. It was inactivated by incubation with trypsin, and was essentially found only in media conditioned by muscle and liver cells. The factor in PNME, on the other hand, bound to plastic culture wells and was found in extracts of a variety of tissues. Its concentration in postnatal leg muscle was developmentally regulated: the specific activity increased approximately 10-fold between hatching and Day 3 (maximum value: 3200 units/mg protein) and then fell back to nearly its original levels by Day 7. Evidence is presented that the observed effects of these two neurite-promoting factors did not result from differential survival in vitro of different cell subpopulations. Possible roles for the two active factors during motoneuron development are discussed.

Animals↗
PubMed1983

Denervation increases a neurite-promoting activity in extracts of skeletal muscle.

During early stages of embryonic development, the motoneurones of the spinal cord send out axons that penetrate the differentiating muscle masses and establish connections with individual muscle fibres. It has been proposed that during this period the survival, differentiation and axon outgrowth of the motoneurones depend upon retrograde factors produced by the muscles, and in a previous study, we used a quantitative assay for neurite outgrowth from dissociated embryonic spinal neurones in vitro to characterize a neurite-promoting activity in media conditioned by embryonic muscle cells. At the adult neuromuscular junction, if some of the axons supplying a muscle are experimentally interrupted, fine nerve processes 'sprout' from the remaining intramuscular nerves and grow to innervate the denervated muscle fibres. In this situation also, it has been postulated that the denervated fibres release a diffusible sprouting stimulus. Using the same in vitro assay as before, we now report a striking increase of neurite-promoting activity in extracts of neonatal chick leg muscle after total denervation.

Animals↗
PubMed1981

Neurite outgrowth from embryonic chicken spinal neurons is promoted by media conditioned by muscle cells.

The effect of media conditioned by muscle cells on the development in vitro of chicken spinal neurons was studied. Neural tube cells of 4.5-day chicken embryos were dissociated after trypsinization and cultured in serum-free minimum essential medium conditioned for 4 days over cultures of fused chicken myotubes. After 20 hr in conditioned medium (protein concentration, 10--50 microgram/ml), about 50% of surviving cells had extended neurites, whereas in cultures in nonconditioned medium this value was about 10%. The active factor(s) in conditioned medium is macromolecular and its activity was completely destroyed by incubation with trypsin. Concentrated samples of conditioned medium were analyzed by gel filtration on columns of Sepharose CL-6B. The activity was recovered in peaks with apparent molecular weights of 40,000 and 500,000 and at the exclusion volume of the column. Media conditioned neurite-promoting activity but at lower levels. No activity was detected in Nerve Growth Factor, insulin, fetal calf serum, or horse serum or in media conditioned by chicken lung, chicken heart, or C6 glioma cells.

Animals↗
PubMed1979

Biochemical and immunological studies on the P400 protein, a protein characteristic of the Purkinje cell from mouse and rat cerebellum.

The P400 protein is a glycoprotein of high apparent molecular weight which is abundant in isolated cerebellar Purkinje cells. On SDS polyacrylamide gels, the P400 protein reacts with 125I plant lectins such as 125I Con A. This reaction is used to increase the level of detection of the protein. The P400 protein is purified by successive extraction of synaptosomal and microsomal membranes with 2% Triton X-100 and 25% Na-cholate and preparative gel electrophoresis in SDS. The specific content of P400 protein decreases in the cerebella from homozygous nervous and Purkinje cell degeneration mutant mice, where the total number of Purkinje cells is markedly reduced, and increases in those of the reeler and weaver mice where a deficit of the granule cells exists. In the cerebellum from the homozygous staggerer mouse, a small amount of P400 protein persists. During postnatal development the specific content of P400 protein per net weight does not change up to the 12th day after birth then increases up to the 25th day when it reaches the adult level. Antisera have been raised against the purified P400 protein. They give precipitation lines by the immunodiffusion reaction of Ouchterlony against a preparation of P400 protein submitted to mild proteolytic attack. Indirect immunofluorescence performed on slices of rat cerebellum with purified anti-P400 immunoglobulin G, absorbed or not on rat cerebrum membranes, reveals that both the soma and the dendritic arborization of the Purkinje cells are labelled. The neurons from the deep cerebellar nuclei are not stained.

Animals↗
PubMed1976

Anatomical, physiological and biochemical studies on the cerebellum from mutant mice. III. Protein differences associated with the weaver, staggerer and nervous mutations.

The protein composition of subcellular fractions of the cerebella of normal and weaver, staggerer and nervous mutant mice and of X-irradiated rats are studied by polyacrylamide gel electrophoresis in sodium dodecyl sulphate. The patterns observed are compared with those of granular and Purkinje cells purified from rat cerebella. In particulate fractions from weaver and X-irradiated rat cerebella, several protein bands are missing. These bands are present in purified rat granular cells. The most obvious deficit concerns a nuclear protein of apparent molecular weight 30,000, presumably the F1 histone. In these agranular cerebella the total DNA content is approximately 7 times lower than in the control animals and the DNA to protein ratio decreases approximately by a factor of two. In the cerebella from homozygous staggerer and nervous mutant mice, where the Purkinje cells are either abnormal or absent, a protein of apparent molecular weight 400,000 is markedly reduced. This membrane-bound protein is present in preparations of purified Purkinje cells.

Animals↗