Key molecules in axon regeneration
| Date |
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2013 |
Suaugusiu žinduoliu centrines nervu sistemos (CNS) vystymasis glaudžiai siejasi su spontani ško gebejimo regeneruoti po pažaidu praradimu. Savo ruoštu periferines nervu sistemos (PNS) aksonai gebejim¹ regeneruoti po pa˛aidu i laiko vis¹ gyvenim¹. Santykis tarp augim¹ skatinančiu ir augim¹ slopinančiu veiksniu, ekspresuojamu tiek nerviniu, tiek ir ne nerviniu l¹steliu pa˛aidos aplinkoje, s¹lygoja regeneracijos sekmź. Dalis signaliniu molekuliu, taip pat ir augim¹ reguliuojantys veiksniai, yra gaminamos per vis¹ gyvenim¹, tačiau kai kuriu ju rai ka ypač padideja po CNS pa˛aidos, kai jos riboja aksonu augim¹ bei paveikia kitu l¹steliu elgsen¹. Efrinu, Semaforinu, Slit ir Netrinu klases molekules yra pagrindiniai veiksniai, trukdantys sekmingai CNS regeneracijai ir funkciju atkurimui. PNS neuronai inicijuoja reparacijos mechanizmus i karto po pa˛aidos atsiradimo ir sekmingai atkuria savo funkcijas net tada, kai pa˛aidos plotas siekia kelis centimetrus. Skirtumu tarp PNS ir CNS regeneracijos mechanizmu ir juose dalyvaujančiu veiksniu suvokimas yra svarbus tiek tiriant nervu sistemos plasti kum¹, tiek taikant naujas nervu sistemos pa˛aidu atkurimo strategijas.
Development of adult mammal central nervous system (CNS) is closely related to loosing the ability spontaneously regenerate after injuries. On the other hand, peripheral nervous system (PNS) maintains its capability to regenerate after injuries entire lifespan. Ability to regenerate successfully is mainly determined by the balance of growth promoting and growth inhibiting factors, expressed by both neuronal and non-neuronal cells found in the injury site. Some of signaling cues involved in regeneration are expressed in adult CNS constantly, although expression of other factors occurs only in the injury site of adult mammal. Ephrins, Semaphorins, Slits and Netrins are among most important molecules involved in lack of success in regeneration of CNS. PNS neurons initiate reparation mechanisms right after development of injury, and are capable to recover functional activity even if an area of injury is more than several centimeters wide. Understanding of differences between CNS and PNS regeneration and factors involved in functional nervous system recovery are crucial for both in depth analysis of plasticity of adult mammal neural system, and for developing new treatment strategies.