Showing papers by "French Institute of Health and Medical Research published in 1993"
TL;DR: Northern hybridization revealed that Fas ligand is expressed in activated splenocytes and thymocytes, consistent with its involvement in T cell-mediated cytotoxicity and in several nonlymphoid tissues, such as testis.
2,600 citations
TL;DR: It is reported that O·- 2 is produced upon NMDA receptor stimulation in cultured cerebellar granule cells and the nitrone DMPO (5,5-dimethyl pyrroline 1-oxide), used as a spin trap, is more efficient than the nitric oxide synthase inhibitor, L-N G -nitroarginine, in reducing NMDA-induced neuronal death in these cultures.
Abstract: NEURONAL injury resulting from acute brain insults and some neurodegenerative diseases implicates N-methyl-D-aspartate (NMDA) glutamate receptors1–4. The fact that antioxidants reduce some types of brain damage suggests that oxygen radicals may have a role5–7. It has been shown that mutations in Cu/Zn-superoxide dismutase (SOD), an enzyme catalysing superoxide (O·-2) detoxification in the cell, are linked to a familial form of amyotrophic lateral sclerosis (ALS)4. Here we report that O·-2 is produced upon NMDA receptor stimulation in cultured cerebellar granule cells. Electron paramagnetic resonance was used to assess O·-2 production that was due in part to the release of arachidonic acid. Activation of kainic acid receptors, or voltage-sensitive Ca2+ channels, did not produce detectable O·-2. We also find that the nitrone DMPO (5,5-dimethyl pyrroline 1-oxide), used as a spin trap, is more efficient than the nitric oxide synthase inhibitor, L-NG-nitroarginine, in reducing NMDA-induced neuronal death in these cultures.
1,224 citations
TL;DR: Pneumonias occurring in ventilated patients, especially those due to Pseudomonas or Acinetobacter species, are associated with considerable mortality in excess of that resulting from the underlying disease alone, and significantly prolong the length of stay in the intensive care unit.
1,151 citations
TL;DR: In this paper, the authors used positional cloning to identify a gene partially deleted in 6 of 85 independent patients with Adrenoleukodystrophy (ALD) and two identical deletions were detected in two brothers presenting with different clinical ALD phenotypes.
Abstract: Adrenoleukodystrophy (ALD) is an X-linked disease affecting 1/20,000 males either as cerebral ALD in childhood or as adrenomyeloneuropathy (AMN) in adults. Childhood ALD is the more severe form, with onset of neurological symptoms between 5-12 years of age. Central nervous system demyelination progresses rapidly and death occurs within a few years. AMN is a milder form of the disease with onset at 15-30 years of age and a more progressive course. Adrenal insufficiency (Addison's disease) may remain the only clinical manifestation of ALD. The principal biochemical abnormality of ALD is the accumulation of very-long-chain fatty acids (VLCFA) because of impaired beta-oxidation in peroxisomes. The normal oxidation of VLCFA-CoA in patients' fibroblasts suggested that the gene coding for the VLCFA-CoA synthetase could be a candidate gene for ALD. Here we use positional cloning to identify a gene partially deleted in 6 of 85 independent patients with ALD. In familial cases, the deletions segregated with the disease. An identical deletion was detected in two brothers presenting with different clinical ALD phenotypes. Candidate exons were identified by computer analysis of genomic sequences and used to isolate complementary DNAs by exon connection and screening of cDNA libraries. The deduced protein sequence shows significant sequence identity to a peroxisomal membrane protein of M(r) 70K that is involved in peroxisome biogenesis and belongs to the 'ATP-binding cassette' superfamily of transporters.
1,108 citations
TL;DR: To the knowledge, this is the first case of circular transcripts being processed from nuclear pre‐mRNA in eukaryotes, and might represent a novel aspect of gene expression and hold some interesting clues about the splicing mechanism.
Abstract: We previously identified novel human ets-1 transcripts in which the normal order of exons is inverted, and demonstrated that although the order of exons is different than in the genomic DNA, splicing of these exons out of order occurs in pairs using genuine splice sites (1). Here we determine the structure of these novel transcripts, showing that they correspond to circular RNA molecules containing only exons in genomic order. These transcripts are stable molecules, localized in the cytoplasmic component of the cells. To our knowledge, this is the first case of circular transcripts being processed from nuclear pre-mRNA in eukaryotes. This new type of transcript might represent a novel aspect of gene expression and hold some interesting clues about the splicing mechanism.
934 citations
TL;DR: How several Ets-related proteins fit into this scheme, and how their activity is regulated both post- and pre-translationally are discussed are discussed.
Abstract: Interest in the Ets proteins has grown enormously over the last decade. The v-ets oncogene was originally discovered as part of a fusion protein expressed by a transforming retrovirus (avian E26), and later shown to be transduced from a cellular gene. About 30 related proteins have now been found in species ranging from flies to humans, that resemble the vEts protein in the so-called 'ets domain'. The ets domain has been shown to be a DNA-binding domain, that specifically interacts with sequences containing the common core trinucleotide GGA. Furthermore, it is involved in protein-protein interactions with co-factors that help determine its biological activity. Many of the Ets-related proteins have been shown to be transcription activators, like other nuclear oncoproteins and anti-oncoproteins (Jun, Fos, Myb, Myc, Rel, p53, etc.). However, Ets-like proteins may have other functions, such as in DNA replication and a general role in transcription activation. Ets proteins have been implicated in regulation of gene expression during a variety of biological processes, including growth control, transformation, T-cell activation, and developmental programs in many organisms. Signals regulating cell growth are transmitted from outside the cell to the nucleus by growth factors and their receptors. G-proteins, kinases and transcription factors. We will discuss how several Ets-related proteins fit into this scheme, and how their activity is regulated both post- and pre-translationally. Loss of normal control is often associated with conversion to an oncoprotein. vEts has been shown to have different properties from its progenitor, which might explain how it has become oncogenic. Oncogene-related products have been implicated in the control of various developmental processes. Evidence is accumulating for a role for Ets family members in Drosophila development, Xenopus oocyte maturation, lymphocyte differentiation, and viral infectious cycles. An ultimate hope in studying transformation by oncoproteins is to understand how cells become cancerous in humans, which would lead to more effective treatments. vEts induces erythroblastosis in chicken. Cellular Ets-family proteins can be activated by proviral insertion in mice and, most interestingly, by chromosome translocation in humans. We are at the beginning of understanding the multiple facets of regulation of Ets activity. Future work on the Ets family promises to provide important insights into both normal control of growth and differentiation, and deregulation in illness.
870 citations
TL;DR: It is concluded that Fas was involved in the Ca(2+)-independent component of cytotoxicity mediated by at least two sources of T cells, namely nonantigen-specific in vitro activated hybridoma cells, and antigen- specific in vivo raised peritoneal exudate lymphocytes.
Abstract: Mechanisms of T cell-mediated cytotoxicity remain poorly defined at the molecular level. To investigate some of these mechanisms, we used as target cells, on the one hand, thymocytes from lpr and gld mouse mutants, and on the other hand, L1210 cells transfected or not with the apoptosis-inducing Fas molecule. These independent mutant or transfectant-based approaches both led to the conclusion that Fas was involved in the Ca(2+)-independent component of cytotoxicity mediated by at least two sources of T cells, namely nonantigen-specific in vitro activated hybridoma cells, and antigen-specific in vivo raised peritoneal exudate lymphocytes. Thus, in these cases, T cell-mediated cytotoxicity involved transduction via Fas of the target cell death signal.
822 citations
TL;DR: Findings suggest that transcription and nucleotide excision repair may share common factors and hence may be considered to be functionally related.
Abstract: The human BTF2 basic transcription factor (also called TFIIH), which is similar to the delta factor in rat and factor b in yeast, is required for class II gene transcription. A strand displacement assay was used to show that highly purified preparation of BTF2 had an adenosine triphosphate-dependent DNA helicase activity, in addition to the previously characterized carboxyl-terminal domain kinase activity. Amino acid sequence analysis of the tryptic digest generated from the 89-kilodalton subunit of BTF2 indicated that this polypeptide corresponded to the ERCC-3 gene product, a presumed helicase implicated in the human DNA excision repair disorders xeroderma pigmentosum and Cockayne's syndrome. These findings suggest that transcription and nucleotide excision repair may share common factors and hence may be considered to be functionally related.
788 citations
TL;DR: A 31-kb fragment of the large virulence plasmid of Shigella flexneri is necessary for bacterial entry into epithelial cells in vitro and lack of either IpaB or IpaD resulted in the release of larger amounts of the other Ipa polypeptides into the culture medium, which indicates that, in addition to their role in invasion, IPAB and Ipa D are each involved in the maintenance of the association of the Ipa proteins with the bacter
Abstract: A 31-kb fragment of the large virulence plasmid of Shigella flexneri is necessary for bacterial entry into epithelial cells in vitro. One locus of this fragment encodes the IpaA, -B, -C, and -D proteins, which are the dominant antigens of the humoral immune response during shigellosis. To address the role of the ipa genes, which are clustered in an operon, we constructed a selectable cassette that does not affect transcription of downstream genes and used this cassette to inactivate the ipaB, ipaC, and ipaD genes. Each of these nonpolar mutants was defective in entry and lysis of the phagocytic vacuole but was not impaired in adhesion to the cells. We showed that, like IpaB and IpaC, IpaD is secreted into the culture supernatant and that none of these proteins is necessary for secretion of the other two. This result differentiates the Ipa proteins, which direct the entry process, from the Mxi and Spa proteins, which direct secretion of the Ipa proteins. Moreover, lack of either IpaB or IpaD resulted in the release of larger amounts of the other Ipa polypeptides into the culture medium, which indicates that, in addition to their role in invasion, IpaB and IpaD are each involved in the maintenance of the association of the Ipa proteins with the bacterium.
744 citations
Journal Article•
744 citations
TL;DR: Immunohistochemistry shows a cytoplasmic localization of FMR–1, and the highest levels were observed in neurons, while glial cells contain very low levels, in epithelial tissues, and in adult testis, FMR-1 was detected only in spermatogonia.
Abstract: Fragile X mental retardation syndrome is caused by the unstable expansion of a CGG repeat in the FMR–1 gene. In patients with a full mutation, abnormal methylation results in suppression of FMR–1 transcription. FMR–1 is expressed in many tissues but its function is unknown. We have raised monoclonal antibodies specific for the FMR–1 protein. They detect 4–5 protein bands which appear identical in cells of normal males and of males carrying a premutation, but are absent in affected males with a full mutation. Immunohistochemistry shows a cytoplasmic localization of FMR–1. The highest levels were observed in neurons, while glial cells contain very low levels. In epithelial tissues, levels of FMR–1 were higher in dividing layers. In adult testis, FMR–1 was detected only in spermatogonia. FMR–1 was not detected in dermis and cardiac muscle except under pathological conditions.
Journal Article•
TL;DR: CTLA-8 may belong to the growing set of virus-captured functionally important cellular genes related to the immune system or to cell death and cell survival, and is discussed in the context of other genes of this herpesvirus homologous to known immunologically active molecules.
Abstract: To detect novel molecules involved in immune functions, a subtracted cDNA library between closely related murine lymphoid cells was prepared using improved technology. Differential screening of this library yielded several clones with a very restricted tissue specificity, including one that we named CTLA-8. CTLA-8 transcripts could be detected only in T cell hybridoma clones related to the one used to prepare the library. Southern blots showed that the CTLA-8 gene was single copy in mice, rats, and humans. By radioactive in situ hybridization, the CTLA-8 gene was mapped at a single site on mouse chromosome 1A and human chromosome 2q31, in a known interspecific syntenic region. The CTLA-8 cDNA sequence indicated the presence, in the 3'-untranslated region of the mRNA, of AU-rich repeats previously found in the mRNA of various cytokines, growth factors, and oncogenes. The CTLA-8 cDNA contained an open reading frame encoding a putative protein of 150 amino acids. This protein was 57% homologous to the putative protein encoded by the ORF13 gene of herpesvirus Saimiri, a T lymphotropic virus. These findings are discussed in the context of other genes of this herpesvirus homologous to known immunologically active molecules. More generally, CTLA-8 may belong to the growing set of virus-captured functionally important cellular genes related to the immune system or to cell death and cell survival.
TL;DR: In this paper, the authors compare regional cerebral blood flow (rCBF) while French monolingual subjects listen to continuous speech in an unknown language, to lists of French words, or to meaningful and distorted stories in French.
Abstract: In this study, we compare regional cerebral blood flow (rCBF) while French monolingual subjects listen to continuous speech in an unknown language, to lists of French words, or to meaningful and distorted stories in French. Our results show that, in addition to regions devoted to single-word comprehension, processing of meaningful stories activates the left middle temporal gyrus, the left and right temporal poles, and a superior prefrontal area in the left frontal lobe. Among these regions, only the temporal poles remain activated whenever sentences with acceptable syntax and prosody are presented.
TL;DR: A method using PCR amplification and primer extension with fluorescent oligonucleotides was developed to analyze T-cell repertoires and shows that beta chains are distributed into at least 2000 groups, a value that provides a lower limit to their complexity.
Abstract: A method using PCR amplification and primer extension with fluorescent oligonucleotides was developed to analyze T-cell repertoires. The sizes of the hypervariable CDR3-like regions of the murine T-cell antigen receptor beta chains were measured for all possible V beta-J beta combinations. This analysis shows that beta chains are distributed into at least 2000 groups, a value that provides a lower limit to their complexity. The CDR3 sizes appear to be dependent on the J beta and especially the V beta segment used and correlates with amino acid sequence motifs in the corresponding CDR1 region. This feature of T-cell receptors is discussed.
TL;DR: Five adrenoceptor subtypes are involved in the adrenergic regulation of white and brown fat cell function and large species-specific differences exist in brown and white fat cell adreno receptor distribution and in their relative importance in the control of the fat cell.
TL;DR: The results reveal the existence of a skeletogenic ground pattern program common to at least the mesenchymal NCC that originated from rhombomeres 2 and 4 and the appearance of an atavistic reptilian pterygoquadrate element in Hoxa-2 mutants suggests that this ground pattern is intermediate between reptiles and mammals.
TL;DR: The computer simulations account for several phenomena in the numerical domain, including the distance effect and Fechner's law for numbers, and demonstrate that infants' numerosity detection abilities may be explained without assuming that infants can count.
Abstract: Despite their lack of language, human infants and several animal species possess some elementary abilities for numerical processing. These include the ability to recognize that a given numerosity is being presented visually or auditorily, and, at a later stage of development, the ability to compare two nume-rosities and to decide which is larger. We propose a model for the development of these abilities in a formal neuronal network. Initially, the model is equipped only with unordered numerosity detectors. It can therefore detect the numerosity of an input set and can be conditioned to react accordingly. In a later stage, the addition of a short-term memory network is shown to be sufficient for number comparison abilities to develop. Our computer simulations account for several phenomena in the numerical domain, including the distance effect and Fechner's law for numbers. They also demonstrate that infants' numerosity detection abilities may be explained without assuming that infants can count. The neurobiological bases of the critical components of the model are discussed.
TL;DR: The investigation of the capacity of these flavonoids to remove iron from iron-loaded hepatocytes revealed a good relationship between this iron-chelating ability and the cytoprotective effect, increasing the prospects for the development and clinical application of these potent antioxidants.
TL;DR: Northern blot and in situ hybridization analyses showed the 5-HT7 transcripts to be expressed in discrete areas of the limbic brain (e.g., pyramidal hippocampus cells, tenia tecta, amygdaloid, or mammillary nuclei), suggesting that the receptor mediates serotoninergic controls in functions like mood, learning, or neuroendocrine and vegetative behaviors.
Abstract: By using a strategy based on nucleotide sequence homology, we have cloned a cDNA encoding a functional serotonin (5-HT) receptor. The deduced amino acid sequence of the 5-HT7 receptor displays limited homology with that of other 5-HT receptors. In addition to the seven stretches of hydrophobic amino acids that characterize the superfamily of receptors interacting with guanine nucleotide-binding proteins, the 448-aa sequence of the 5-HT7 receptor contains a hydrophobic domain located at its N-terminal end. Genomic analysis indicated the presence of introns interrupting the coding sequence. The 5-HT7 receptor, stably expressed in transfected CHO cells, bound [3H]5-HT with high affinity (Kd = 1 nM), like receptors of the 5-HT1 subfamily from which, however, it was clearly distinguished by its pharmacology. 5-HT in nanomolar concentrations stimulated cAMP accumulation in these CHO cells by approximately 10-fold, whereas lysergic acid diethylamide displayed low intrinsic agonist activity. These various properties differentiate the 5-HT7 receptor from the four other subfamilies of mammalian 5-HT receptors (i.e., the 5-HT1-, 5-HT2-, 5-HT3-, and 5-HT4-like subfamilies) and, therefore, appear to define another receptor subfamily. Northern blot and in situ hybridization analyses showed the 5-HT7 transcripts to be expressed in discrete areas of the limbic brain (e.g., pyramidal hippocampus cells, tenia tecta, amygdaloid, or mammillary nuclei), suggesting that the receptor mediates serotoninergic controls in functions like mood, learning, or neuroendocrine and vegetative behaviors.
TL;DR: It is reported that CREM is unique within the family of cAMP-responsive promoter element (CRE)-binding factors since it is inducible by activation of the cAMP signaling pathway and constituting a negative autoregulatory loop.
TL;DR: The observed RARγ null phenotype suggests a high degree of functional redundancy among the RARs, and the variable penetrance of some of the observed defects is discussed in light of this redundancy and stochastic variation of gene activity.
TL;DR: Genetic linkage analysis in two unrelated families and Multilocus analysis with the location scores method established the best estimate for the location of the affected gene within a 14 centimorgan interval bracketed by D19S221 and D19 S222 loci.
Abstract: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) has been recently reported as a cause of stroke. It is characterized, in the absence of hypertension, by recurrent subcortical ischaemic strokes, starting in early or midadulthood and leading in some patients to dementia. Magnetic resonance imaging and pathological examination show numerous small subcortical infarcts and a diffuse leukoencephalopathy underlaid by a non–arteriosclerotic, non–amyloid angiopathy. We performed genetic linkage analysis in two unrelated families and assigned the disease locus to chromosome 19q12. Multilocus analysis with the location scores method established the best estimate for the location of the affected gene within a 14 centimorgan interval bracketed by D19S221 and D19S222 loci.
TL;DR: In a group of DR3/DR4 heterozygous patients with insulin‐dependent diabetes mellitus (IDDM), the frequency of the TNFa2 allele was higher than in HLA‐DR matched controls, whereas theTNFa6 allele was more frequent in control individuals.
Abstract: We have investigated the correlation between different tumor necrosis factor (TNF) and class II major histocompatibility complex alleles in the lipopolysaccharide- or phytohemagglutinin-induced secretion of TNF-α and TNF-β by human monocytes and peripheral blood mononuclear cells in 87 unrelated Danish male individuals. Significant differences in TNF-α secretory capacity between TNF Ncol restriction fragment length polymorphisms, TNFa and TNFc micro-satellite alleles and DR alleles were identified. No correlation with TNF-β secretory capacity was found for any of the markers studied. TNF genotyping allowed us to define four extended HLA haplotypes which correlate with TNF-α secretory capacity. Two of these are DR4 positive: DQw8, DR4, TNFB*1, TNFa6, B44, A2 and DQw8, DR4, TNFB*2, TNFa2, B15, A2. Individuals carrying the TNFB*2, TNFa2 haplotype had a higher TNF-α secretory capacity than those carrying the TNFB*1, TNFa6 haplotype. In a group of DR3/DR4 heterozygous patients with insulin-dependent diabetes mellitus (IDDM), the frequency of the TNFa2 allele was higher than in HLA-DR matched controls, whereas theTNFa6 allele was more frequent in control individuals. In the DR3/DR4 heterozygous diabetic group 12/26 had the alleles combination DQw8, DR4 (Dw4), C4A3, TNFB*2, TNFa2, B15, whereas only 1/18 controls had this haplotype. This diabetogenic haplotype is identical to the DR4 haplotype which correlates with a higher TNF-α response. These observations suggest a direct role for the TNF locus in the pathogenesis of IDDM.
TL;DR: Adenovirus vectors appear to be a promising means for in vivo transfer of therapeutic genes into the central nervous system.
Abstract: The ability of a replication-deficient adenovirus vector to transfer a foreign gene into neural cells of adult rats in vivo has been analysed. A large number of neural cells (including neurons, astrocytes and ependymal cells) expressed an E. coli lacZ transgene for at least 45 days after inoculation of various brain areas. Injecting up to 3 x 10(5) pfu in 10 microliters did not result in any detectable cytopathic effects--these were only observed for very high titres of infection (> 10(7) pfu 10 microliters-1). Adenovirus vectors therefore appear to be a promising means for in vivo transfer of therapeutic genes into the central nervous system.
TL;DR: In Ewing's sarcoma and malignant melanoma of soft parts, translocations of band 22q12 to chromosome 11 and 12 result in the fusion of EWS with the transcription factors FLI‐1 and ATF1, respectively, suggesting that oncogenic conversion is achieved by the linking of the two domains with no marked constraint on the connecting peptide.
Abstract: Balanced translocations involving band q12 of human chromosome 22 are the most frequent recurrent translocations observed in human solid tumours. It has been shown recently that this region encodes EWS, a protein with an RNA binding homologous domain. In Ewing's sarcoma and malignant melanoma of soft parts, translocations of band 22q12 to chromosome 11 and 12 result in the fusion of EWS with the transcription factors FLI-1 and ATF1, respectively. The present analysis of 89 Ewing's sarcomas and related tumours show that in addition to the expected EWS-FLI-1 fusion, the EWS gene can be fused to ERG, a transcription factor closely related to FLI-1 but located on chromosome 21. The position of the chromosome translocation breakpoints are shown to be restricted to introns 7-10 of the EWS gene and widely dispersed within introns 3-9 of the Ets-related genes. This heterogeneity generates a variety of chimeric proteins that can be detected by immuno-precipitation. On rare occasions, they may be associated with a truncated EWS protein arising from alternate splicing. All 13 different fusion proteins that were evidenced contained the N-terminal domain of EWS and the Ets domain of FLI-1 or ERG suggesting that oncogenic conversion is achieved by the linking of the two domains with no marked constraint on the connecting peptide.
TL;DR: The results show that ACE is expressed in T-lymphocytes and indicate that the level of ACE expression in cells synthesizing the enzyme is genetically determined, which is highly reproducible and influenced by the polymorphism of the ACE gene.
Abstract: The expression of angiotensin-I converting enzyme (ACE; EC 3.4.15.1) in human circulating mononuclear cells was studied. T-lymphocytes contained the highest level of enzyme, approx. 28 times more per cell than monocytes. No activity was detected in B-lymphocytes. ACE was present mainly in the microsomal fraction, where it was found to be the major membrane-bound bradykinin-inactivating enzyme. An mRNA for ACE was detected and characterized after reverse transcription and amplification by PCR in T-lymphocytes and several T-cell leukaemia cell lines. We have previously observed that the interindividual variability in the levels of ACE in plasma is, in part, genetically determined and influenced by an insertion/deletion polymorphism of the ACE gene. To investigate the mechanisms involved in the regulation of ACE biosynthesis, the ACE levels of T-lymphocytes from 35 healthy subjects having different ACE genotypes were studied. These levels varied widely between individuals but were highly reproducible and influenced by the polymorphism of the ACE gene. T-lymphocyte levels of ACE were significantly higher in subjects who were homozygote for the deletion than in the other subjects. These results show that ACE is expressed in T-lymphocytes and indicate that the level of ACE expression in cells synthesizing the enzyme is genetically determined.
Journal Article•
TL;DR: These results provide the first demonstration that various cytokines act directly on human hepatocytes to affect expression of major P-450 genes and that a wide range of responses can be observed among the enzymes for a given cytokine, suggesting that different regulatory mechanisms may be involved.
Abstract: Cytokines are thought to cause the depression of cytochrome P-450 (CYP)-associated drug metabolism in humans during inflammation and infection. We have examined the role of five cytokines, i.e., interleukin-1 beta, interleukin-4, interleukin-6, tumor necrosis factor-alpha, and interferon-gamma, on the expression of CYP1A2, CYP2C, CYP2E1, CYP3A, and epoxide hydrolase in primary human hepatocyte cultures. Steady state P-450 and epoxide hydrolase mRNA levels, as well as ethoxyresorufin-O-deethylase and nifedipine oxidation activities, which are mainly supported by CYP1A1/1A2 and CYP3A, respectively, were measured. Interleukin-1 beta, interleukin-6, and tumor necrosis factor-alpha were found to be the most potent depressors of P-450 enzymes. After 3 days of treatment, both mRNA levels and enzyme activities were depressed, typically by at least 40%, whatever the cytokine and the enzyme considered. Interferon-gamma also suppressed CYP1A2 and CYP2E1 mRNA levels and ethoxyresorufin-O-deethylase activity but had no effect on CYP3A and epoxide hydrolase mRNAs. In addition, interleukin-4 had the opposite effect, compared with other cytokines, on CYP2E1 mRNA, which was increased up to 5-fold; ethoxyresorufin-O-deethylase and nifedipine oxidation activities were not significantly affected. These results provide the first demonstration that various cytokines act directly on human hepatocytes to affect expression of major P-450 genes and that a wide range of responses can be observed among the enzymes for a given cytokine, suggesting that different regulatory mechanisms may be involved.
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TL;DR: The α-granule is a unique secretory organelle in that it exhibits further compartmentalization and acquires its protein content via two distinct mechanisms: (1) biosynthesis predominantly at the megakaryocyte (MK) level (with some vestigial platelet synthesis) and (2) endocytosis and pinocythosis at both the MK and circulating platelet levels (e.g. platelet factor 4) as discussed by the authors.
TL;DR: In vivo, in vivo, a sarcolemmal immunostaining is obtained in up to 50% of fibres of the injected muscle of progressive muscular dystrophy.
Abstract: DUCHENNE progressive muscular dystrophy is a lethal and common X-linked genetic disease1 caused by the absence of dystrophin2,3, a 427K protein encoded by a 14 kilobase transcript4. Two approaches have been proposed to correct the dystrophin deficiency in muscle. The first, myoblast transfer therapy, uses cells from normal donors5–7, whereas the second involves direct intramuscular injection of recombinant plasmids expressing dystrophin8. Adenovirus is an efficient vector for in vivo expression of various foreign genes9–13. It has recently been demonstrated that a recombinant adenovirus expressing the lac-Z reporter gene can infect stably many mouse tissues, particularly muscle and heart12,13. We have tested the ability of a recombinant adenovirus, containing a 6.3 kilobase pair Becker-like dystrophin complementary DNA14 driven by the Rous sarcoma virus promoter to direct the expression of a 'minidystrophin' in infected 293 cells and C2 myoblasts, and in the mdx mouse15,16, after intramuscular injection. We report here that in vivo, we have obtained a sarcolemmal immunostaining in up to 50% of fibres of the injected muscle.