Neuroprotective and regenerative effects of fibrin sealant derived from snake venom combined with mononuclear stem cells after repair of the sciatic nerve of neonatal rats

Author(s)

Natalia Perussi Biscola

• Document type: Doctoral Thesis
• Press: Botucatu. 2016-03-28.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Medicina. Botucatu
• Defense date: 2016-02-29
• Advisor: Benedito Barraviera

Abstract

The efficient repair in nervous system related lesions is an ancient challenge for medicine. The use of well-established experimental models allows to evaluate the potential of different treatments in order to prevent the induced changes. The aim of this study was to evaluate the neuroprotective and regenerative potential of bone marrow mononuclear stem cells (BMMSC) after neurorrhaphy with fibrin sealant derived from snake venom on spinal motoneurons and DRG sensory neurons of neonatal rats subjected to sciatic nerve axotomy. Therefore, the animals were divided into six groups: Group I (AX): axotomy of the sciatic nerve without treatment; Group II (AX+FS): axotomy of the sciatic nerve, followed by end-to-end neurorrhaphy with fibrin sealant produced by CEVAP; Group III (AX+FS+BMMSC): axotomy of sciatic nerve, followed by treatment with BMMSC and endto- end neurorrhaphy with fibrin sealant from CEVAP; Group IV (AX+BMMSC): sciatic nerve axotomy and treatment with BMMSC; Group V(AX+CFS): axotomy of the sciatic nerve, followed by end-toend neurorrhaphy with commercial fibrin sealant; Group VI: Control group without lesion (motor tests). The samples were analyzed 4, 8 and 12 weeks post lesion. Flow cytometry was used to characterize the BMMSC. Immunohistochemistry to evaluate reactive gliosis, microglial reaction and synapse preservation. Nissl staining was employed to investigate neuronal survival; axonal regeneration by sciatic nerve morphometry; synaptic inputs, by spinal cord morphometry. Additionally, motor (walking track test) and sensitive (von Frey) behavior recovery was studied and correlated with morphological data. ANOVA and Bonferroni post-test was used for statistical analyses. Neurorrhaphy indicated preservation of synaptic covering on lesioned motoneurons and neuronal survival, in the groups repaired with both sealant alone or when treated with BMMSC (around 54%), as compared to axotomy alone (around 32%) in all analyzed survival times. Reactive gliosis and microglial reaction decreased in the same groups (AX+FS, AX+FS+BMMSC, AX+CFS) with 4 weeks. Regarding axonal regeneration, neurorrhaphy allowed recovery of greater number of myelinated fibers, that presented also improved morphometric parameters. In addition, preferential preservation of inhibitory synaptic terminals was detected in neurorrhaphy groups. Such results were accompanied by significant improvement in the motor as well as in the nociceptive recovery. Overall, the present data suggest that acute repair of neonatal peripheral nerves with fibrin sealant result in neuroprotection and regeneration of both motor and DRG neurons, not being further improved by BMMSC therapy. (AU)

• FAPESP's process: 11/23377-7 - Neuroprotective and regenerative effects of fibrin sealant derived from snake venom combined with mononuclear stem cells after neurorrhaphy of the sciatic nerve of neonatal rats
• Grantee: Natália Perussi Biscola
• Support type: Scholarships in Brazil - Doctorate (Direct)