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- Frost, Hanna K, et al.
(författare)
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G-CSF prevents caspase 3 activation in Schwann cells after sciatic nerve transection, but does not improve nerve regeneration
- 2016
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Ingår i: Neuroscience. - : Elsevier BV. - 1873-7544 .- 0306-4522. ; 334, s. 55-63
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Tidskriftsartikel (refereegranskat)abstract
- Exogenous granulocyte-colony stimulating factor (G-CSF) has emerged as a drug candidate for improving the outcome after peripheral nerve injuries. We raised the question if exogenous G-CSF can improve nerve regeneration following a clinically relevant model - nerve transection and repair - in healthy and diabetic rats. In short-term experiments, distance of axonal regeneration and extent of injury-induced Schwann cell death was quantified by staining for neurofilaments and cleaved caspase 3, respectively, seven days after repair. There was no difference in axonal outgrowth between G-CSF-treated and non-treated rats, regardless if healthy Wistar or diabetic Goto-Kakizaki (GK) rats were examined. However, G-CSF treatment caused a significant 13% decrease of cleaved caspase 3-positive Schwann cells at the lesion site in healthy rats, but only a trend in diabetic rats. In the distal nerve segments of healthy rats a similar trend was observed. In long-term experiments of healthy rats, regeneration outcome was evaluated at 90days after repair by presence of neurofilaments, wet weight of gastrocnemius muscle, and perception of touch (von Frey monofilament testing weekly). The presence of neurofilaments distal to the suture line was similar in G-CSF-treated and non-treated rats. The weight ratio of ipsi-over contralateral gastrocnemius muscles, and perception of touch at any time point, were likewise not affected by G-CSF treatment. In addition, the inflammatory response in short- and long-term experiments was studied by analyzing ED1 stainable macrophages in healthy rats, but in neither case was any attenuation seen at the injury site or distal to it. G-CSF can prevent caspase 3 activation in Schwann cells in the short-term, but does not detectably affect the inflammatory response, nor improve early or late axonal outgrowth or functional recovery.
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2. |
- Stenberg, Lena, et al.
(författare)
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Nerve regeneration in chitosan conduits and in autologous nerve grafts in healthy and in type 2 diabetic Goto-Kakizaki rats.
- 2016
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Ingår i: European Journal of Neuroscience. - : Wiley. - 1460-9568 .- 0953-816X. ; 43:3, s. 73-463
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Tidskriftsartikel (refereegranskat)abstract
- Knowledge about nerve regeneration after nerve injury and reconstruction in appropriate diabetic animal models is incomplete. Short-term nerve regeneration after reconstruction of a 10 mm sciatic nerve defect with either a hollow chitosan conduit or an autologous nerve graft was investigated in healthy Wistar and diabetic Goto-Kakizaki (GK) rats. After 21 days, axonal outgrowth, presence of activated and apoptotic Schwann cells, as well as thickness of the formed matrix in the conduits were measured. In general, nerve regeneration was superior in autologous nerve grafts. In chitosan conduits, a matrix, which was thicker in diabetic rats, was formed and was positively correlated with length of axonal outgrowth. Axonal outgrowth in conduits and in nerve grafts extended further in diabetic rats compared to healthy rats. There was a higher percentage of activating transcription factor 3 (ATF-3) immunostained cells in nerve segments from healthy rats compared to diabetic rats after autologous nerve graft reconstruction. In chitosan conduits, more cleaved caspase 3 stained Schwann cells were generally observed in the matrix from the diabetic rats compared to healthy rats. However, there were fewer apoptotic cells in the distal segment in diabetic rats reconstructed with a chitosan conduit. Preoperative glucose levels were positively correlated with axonal outgrowth after both reconstruction mehods. Axonal regeneration was better in autologous nerve grafts compared to hollow chitosan conduits and was enhanced in diabetic GK rats compared to healthy rats after reconstruction. This study provides insights into the nerve regeneration process in a clinically relevant diabetic animal model. This article is protected by copyright. All rights reserved.
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