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C Gillen

Publications and source records attributed to C Gillen.

25 records · Page 2Linked to original sources

Full-lenth cloning, expression and cellular localization of rat plasmolipin mRNA, a proteolipid of PNS and CNS.

We have isolated a 1.476 bp cDNA (NTII11) representing a transcript that is differntially expressed during sciatic nerve development and regeneration in the rat. Nucleotide sequence comparison indicates partial identity with a recently isolated plasmolipin cDNA. However, our clone extends the published sequence by 234 bp at the 5' end and predicts a protein that contains an additional 25 amino acids at th N-terminus. The open reading frame of th NTII11 transcript encodes a 19.4 kDa protein with four putative transmembrane domains. Northern blot analyses revealed a tissue-specific expression was confirmed by in situ hybridization, and cellular localization of plasmolipin mRNA was demonstrated in Schwann cells of the sciatic nerve and in glial cells of myelinated brain structures. The steady-state levels of plasmolipin mRNA were markedly altered (i) during development of sciatic nerve and brain. (ii) after sciatic nerve injury, and (ii) in cured Schwann cells maintained under different conditions of cell growth and arrest. Our data indicate a function of plasmolipin during myelination in the central as well as in the peripheral nervous system.

Amino Acid Sequence↗

A second alternative transcript of the gap junction gene connexin32 is expressed in murine Schwann cells and modulated in injured sciatic nerve.

Four connexin32 (Cx32) cDNA clones isolated from a rat sciatic nerve cDNA library differ in the nucleotide sequence of their 5' untranslated region (UTR) from the corresponding Cx32 cDNA clones previously characterized from liver. The new Cx32 5'UTR sequence detected in the sciatic nerve cDNA clones is identical to one previously found in the 6.5 kb intron of the murine Cx32 gene. Using primer extension and S1 nuclease protection analysis, we determined the transcriptional starting point of this new alternative Cx32 transcript expressed in the sciatic nerve. This starting point is located 444 bp (409 bp) upstream of exon2 in a region previously described as an intron of the Cx32 gene in the rat (and mouse) genome, respectively. The alternative exon1B comprises 99 bp in rat, but 97 bp in the mouse genome, and is spliced to the same exon2 acceptor site also used for splicing of exon1 in liver. Both transcripts are likely to code for the same Cx32 protein whose reading frame is located in exon2. The putative promoter region, upstream of the alternative exon1B, contains a TATAAA motif and has been sequenced and noticed before by Miller et al. (Biosci. Rep. 8, 455-464, (1988)). The alternative exon1B transcript is highly expressed in the sciatic nerve, (i.e. Schwann cells) and very low in liver (i.e. hepatocytes). Its expression is regulated after sciatic nerve injury. The time course of expression was similar to previously established myelin genes and, therefore, we suggest that the expression of the alternative exon1B Cx32 transcript is related to the process of myelination. Very recently, we have characterized another alternative Cx32 exon1A which is transcribed in mouse embryonic stem cells but not in the sciatic nerve (Dahl et al., submitted for publication, 1995). Thus, the murine Cx32 gene is likely to be regulated by three alternative promoters that appear to be activated in a cell type-specific manner.

Animals↗

Differentially expressed genes after peripheral nerve injury.

In an attempt to identify genes associated with Wallerian degeneration and peripheral nerve regeneration we have performed differential hybridization screening of a cDNA library from crushed rat sciatic nerve (7 days postlesion) using radioactively labeled cDNA prepared from poly(A)+ RNA of normal vs. crushed nerve. Screening of 5,000 randomly selected colonies yielded 24 distinct clones that were regulated following nerve injury. Fifteen of the differentially expressed sequences could be classified as induced, whereas 9 sequences appeared to be repressed at 1 week postcrush. Sequencing and computer-assisted sequence comparison revealed 3 classes of regulated cDNA clones representing 1) novel gene sequences (8 clones) including 3 transcripts containing a repetitive "brain identifier" (ID) element; 2) identified genes (7 clones) with previously undetected expression in the peripheral nervous system (PNS), such as apolipoprotein D, peripheral myelin protein 22kD (PMP22), SPARC (secreted protein, acidic and rich in cysteine), sulfated glycoprotein SGP-1, apoferritin, decorin, and X16/SRp20; and 3) identified genes (9 clones) with known expression in the PNS including, e.g., the myelin protein P0, gamma-actin, vimentin, alpha-tubulin, chargerin II, and cytochrome c-oxidase subunit I. Northern blot and polymerase chain reaction analyses with RNA from crushed and transected nerve demonstrated that sequences with related function, like the group of myelin genes, cytoskeleton genes, genes involved in RNA processing and translation, in lipid transport or energy metabolism showed closely related temporal patterns of expression during nerve degeneration and regeneration. Finally, we compared the differentially expressed genes identified at 7 days after crush injury (this investigation) with the regulated sequences isolated previously by De Leon et al. (J Neurosci Res 29:437-488, 1991) from a 3 day postcrush sciatic nerve cDNA library.

Animals↗

Expression of decorin mRNA in the nervous system of rat.

A rat cDNA clone (pCD67) isolated from a cDNA library of regenerating sciatic nerve by differential hybridization screening revealed 75% homology on the nucleic acid level and 81% homology (including conservative amino acid changes) to the deduced amino acid sequence of the core protein of human dermatan/chondroitin sulfate proteoglycan decorin (PGII, PG40, PG-S2). Two transcripts of 1.3 and 1.75 KB very similar in size to the two decorin mRNA species previously identified in connective tissue were detected by Northern blotting in both normal and injured sciatic nerve and in the mature and embryonic rat brain. The steady-state level of the decorin 1.3 KB mRNA was very much higher in peripheral nerve than in the central nervous system or in other non-neural tissues (skeletal muscle, heart, colon, kidney). In situ hybridization experiments indicated that decorin mRNA is expressed by Schwann cells and vascular cells in peripheral nerve. In the spinal cord the ventral horn motor neurons and other neurons in gray matter showed specific hybridization signals. Furthermore, in situ hybridization indicated decorin expression in Purkinje neurons and cells of the molecular layer in cerebellum, and in neurons of the primary olfactory cortex and brainstem (pons). Our data clearly demonstrate decorin mRNA expression in distinct neural cell populations, suggesting yet unknown functions of this proteoglycan in the peripheral and central nervous system.

Amino Acid Sequence↗

Axon-regulated expression of a Schwann cell transcript that is homologous to a 'growth arrest-specific' gene.

We have isolated a 1.8 kb cDNA (pCD25) clone that encodes a transcript that is differentially expressed during nerve regeneration. Nucleotide sequence comparison indicates 89.6% homology with the recently identified murine 'growth arrest-specific' gene gas3. The open reading frame of the CD25 transcript predicts a 17 kDa protein with four putative transmembrane regions. Steady-state levels of the CD25 mRNA are very much higher in sciatic nerve than in other tissues, and expression in sciatic nerve is confined to Schwann cells. Following nerve injury, the transcript levels rapidly declined in nerve segments distal to the site of lesion, but recovered upon nerve regeneration. In contrast, in distal stumps of permanently transected nerves, the mRNA level remained very low. Substantial amounts of the mRNA could be reinduced only upon anastomosis of these interrupted nerve stumps. Re-induction of the mRNA followed the elongation of regenerating axons through the distal nerve segment. Our data indicate that axons regulate expression of the CD25 mRNA in Schwann cells, and suggest that the CD25 protein functions during Schwann cell growth and differentiation.

Amino Acid Sequence↗

Differences between nonprofessional recovering alcoholic counselors treating Bowery alcoholics: a study of therapist variables.

Several treatment variables have been suggested as critical in the outcome of psychiatric therapy. These can be categorized as patient variables, therapy variables, and therapist variables. This study utilized a homogeneous Bowery-patient population, treated in a comprehensive inpatient treatment and rehabilitation program, and attempted to assess differences among nonprofessional recovering alcoholic counselors. The therapeutic outcome of the alcoholic patients was correlated with the values held by the counselors as assessed on the Rokeach Value Scale, suggesting that this instrument may provide an easy to administer and inexpensive screening method for counselors of patients suffering from alcoholism.

Adult↗