| 1. |
- Edbladh, Magnus, et al.
(författare)
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Early regeneration in vitro of adult mouse sciatic axons is dependent on local protein synthesis but may not involve neurotrophins
- 1994
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Ingår i: Neuroscience Letters. - : Elsevier BV. - 0304-3940. ; 168:1-2, s. 37-40
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Tidskriftsartikel (refereegranskat)abstract
- The sensory axons of the adult mouse sciatic nerve were shown to regenerate after a local test crush lesion in vitro in a serum-free medium. The average outgrowth distance of the leading axons after culturing for 3 days was 2.8 ± 0.1 mm, which was shorter than in vivo (3.8 ± 0.2 mm). With the use of a compartmentalised culture system we could show that regeneration was partially dependent on local protein synthesis in the injury region. The initial stages of regeneration did not seem to involve neurotrophins since both K252a and K252b, selective and nontoxic inhibitors of the neurotrophin actions, failed to inhibit axonal growth. The present in vitro model system offers favourable conditions to investigate the early events of the regeneration process in an adult mammalian peripheral nerve.
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| 2. |
- Edström, Anders, et al.
(författare)
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Adenosine inhibition of the regeneration in vitro of adult frog sciatic sensory axons
- 1992
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Ingår i: Brain Research. - 0006-8993. ; 570:1-2, s. 35-41
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Tidskriftsartikel (refereegranskat)abstract
- The sensory axons of the adult frog sciatic nerve have earlier been shown to regenerate in vitro. If a local test crush is made at the initiation of culturing, regeneration starts after 3.4 days and proceeds at a rate of about 0.8-0.9 mm/day for several days. In the present experiments regeneration was inhibited by adenosine in a reversible and dose-dependent fashion. Similarly, both an adenosine analogue, 2-chloroadenosine (2-CA), and a non-hydrolyzable ATP analogue, AMP-PNP, reduced the outgrowth of sensory axons. The effect of adenosine was partially antagonized by theophylline at a critical concentration. Using a compartmental system, it could clearly be shown that adenosine exerted its effects at the outgrowth region. Adenosine, 2-CA, and AMP-PNP were also found to inhibit the proliferation of Schwann cells in the regenerating nerve. Various experiments showed that the latter can not explain the outgrowth inhibitory effects, which could be mediated by adenosine receptors associated with the elongating axons.
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| 3. |
- Edström, Anders, et al.
(författare)
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Regeneration in vitro of the adult frog sciatic sensory axons
- 1990
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Ingår i: Restorative Neurology and Neuroscience. - 0922-6028. ; 1:3-4, s. 261-266
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Tidskriftsartikel (refereegranskat)abstract
- The adult frog sciatic nerve offers several advantages as an in vitro model to study nerve regeneration. The nerve with the attached dorsal root ganglia can easily be isolated and incubated in a culture medium for several days. If the nerve is subjected to a crush immediately after dissection there is a delay of 3.4 days after which the sensory axons start to regenerate into the distal nerve stump at a constant rate of about 1.1 mm · day−1 in serum-containing and 1.0 mm · day−1 in serum-free medium. Serum-free cultures may be used in future studies to examine the effect of various neurotrophic factors. The existence of an accurate method for examining the outgrowth distance, based on axonal transport of labelled proteins, contributes to the attractiveness of the model. A compartmental culture system permits separate exposure of the ganglia and the nerve to different agents. Taking advantage of this, pharmacological studies suggest that Schwann cells produce signals, dependent on newly transcribed RNA, which transform the preparation into a growth state. The present model system offers favourable conditions to learn more about the early events and also the subsequent steps of the regeneration process.
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| 4. |
- Remgård, Pär, et al.
(författare)
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Growth cones of regenerating adult sciatic sensory axons release axonally transported proteins
- 1992
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Ingår i: Brain Research. - 0006-8993. ; 572:1-2, s. 139-145
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Tidskriftsartikel (refereegranskat)abstract
- Labelled, rapidly transported axonal proteins were shown to be released frog adult frog sciatic sensory neurons, regenerating in vitro after a crush injury. The spatial distribution of the transported, released proteins could accurately be resolved by culturing the nerve on nitrocellulose paper, which trapped the released proteins. The release was located to the crush and to the entire outgrowth region. When regeneration was inhibited by adenosine, the release was limited to the crush site, implying that the release was linked to the growing axons. Other experiments suggested that the release emanated from growth cones. Furthermore, two-dimensional electrophoretical analysis of both fast axonally transported and of released proteins showed that the represented a selection of the transported protein species.
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| 5. |
- Wiklund, Peter, et al.
(författare)
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Protein kinase C and mouse sciatic nerve regeneration
- 1996
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Ingår i: Brain Research. - : Elsevier BV. - 0006-8993. ; 715:1-2, s. 145-154
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Tidskriftsartikel (refereegranskat)abstract
- We have studied the role of protein kinase C (PKC) in peripheral nerve regeneration by using the cultured adult mouse sciatic nerve, which displays regrowth of sensory axons under serum-free conditions. By the use of immunohistochemistry we show that one of the isoforms of PKC, PKCβ, is present in the nerve cell bodies of normal nerves and is upregulated after injury. In spite of this, the specific PKC inhibitor chelerythrine at 5 μM, a concentration well above its IC50 value for PKC, failed to reduce the outgrowth distance of new axons. This was not due to impermeability of the drug, since the same concentration caused a clear reduction of the injury-induced proliferation of Schwann cells in the crush region. Likewise, HA-1004, an inhibitor of cyclic nucleotide-dependent protein kinases, also lacked effect on outgrowth when used on its own, even at very high concentrations (100 μM). In contrast, outgrowth was significantly reduced when 5 μM chelerythrine and 5 μM HA-1004 were used in combination. In conclusion, the present results suggest that PKC-activity is important but not indispensable for the regeneration process. Successful completion of the latter could be achieved by several, perhaps redundant, phosphorylation systems.
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