Uticaj B vitaminskih kompleksa i ribavirina na odgovor nervnih i glijskih ćelija i oporavak motornih funkcija nakon povrede mozga pacova

Abstract

Traumatska povreda mozga (TPM) predstavlja veliki zdravstveni problem savremenog društva jer je vodeći uzrok smrti i invaliditeta kod mlađih osoba. Uprkos znatnim istraživačkim i kliničkim naporima, još uvek ne postoji ni jedan dovoljno uspešan terapijski pristup koji utiče na sve patofiziološke procese koji prate moždanu traumu, odnosno, koji može ukloniti sve njene posledice. Stoga se uspešan tretman u borbi protiv TPM danas pokušava pronaći kombinacijom različitih terapijskih tretmana. Poznato je da je oporavak izgubljene funkcije nakon povrede mozga odraslih veoma spor i nepotpun usled nepovratnog uništenja nervnih ćelija i ograničene mogućnosti remodelovanja postojećih i formiranja novih neuronskih veza. Glavna prepreka za uspešniji oporavak posle oštećenja je nepermisivna sredina glijskog ožiljka koji se formira nakon povrede, a koji sprečava izrastanje novih nervnih vlakana i uspostavljanje novih neuronskih veza. Glijski ožiljak čine gusta mreža glijskih ćelija (astrocita i oligodendrocitnih prekursorskih ćelija) i nepropustan vanćelijski matriks (ECM). Cilj ove studije bio je da se ispita dejstvo kompleksa vitamina B (B1, B2, B3, B6 i B12) i ribavirina (RBV, purinskog nukleozidnog analoga) na oporavak motornih funkcija, posle jednostrane ablacije senzomotorne kore (ASK) prednjeg mozga pacova. Mužjacima Wistar soja, starim 2.5 meseca, urađena je ASK prema sledećim koordinatama: 2mm ispred, 4 mm iza bregme i 4 mm lateralno od središnje linije u dubinu do pojave bele mase mozga. Operisane životinje podeljene su, prema tretmanu nakon ASK, u 6 grupa: L grupa – tretirana fiziološkim rastvorom; LK1 grupa – tretirana kombinacijom vitamina B1 (33 mg/kg/dan), B6 (33 mg/kg/dan) i B12 (0,5 μg/kg/dan); LK2 grupa – tretirana kombinacijom vitamina B2 (7,5 mg/kg/dan) i B3 (500 mg/kg/dan); LK grupa – tretirana kombinacijom svih pet vitamina: B1, B2, B3, B6 i B12 u prethodno navedenim dozama; LR grupa – primala je RBV (30 mg/kg/dan); LKR grupa – tretirana kombinacijom svih 5 B vitamina i RBV u prethodno navedenim dozama. Prva injekcija B vitamina data je i.p. 15 minuta nakon ASK, a potom na svaka 24 sata tokom sledećih 14 dana, dok je RBV aplikovan od 3 dana nakon ASK, jednom dnevno do kraja eksperimenta. Uticaj primenjenih tretmana na oporavak nakon ASK praćen je testiranjem ponašanja (test prelaska preko grede - BW test), RT-PCR i Western blot analizom, kao i različitim imunohistohemijskim metodama...

Traumatic brain injury (TBI) is a major health problem in modern society, being a leading cause of death and disability among young people. Despite huge basic research and clinical efforts an effective treatment for TBI has not been established yet, that will counteract all of pathophysiological processes accompanying brain trauma. Therefore, a best possible present treatment that would act on several secondary processes in TBI is based on a combination of different therapeutic approaches. A recovery of lost functions after brain injury is slow and incomplete in adults, due to the irreversible destruction of nerve cells and the limited ability of brain tissue for remodeling of existing and formation of new synaptic connections. The main obstacle for a successful recovery is existence of non-permissive glial scar, which emerges after a brain trauma preventing axonal sprouting and the establishment of new neural circuits. Glial scar consists of a dense network of glial cells (astrocytes and oligodendrocyte precursor cells) and dense extracellular matrix (ECM). The aim of this study was to explore the effects of vitamin B complex (B1, B2, B3, B6 and B12) and ribavirin (RBV, a purine nucleoside analogue) on the recovery of motor function after unilateral sensorimotor cortex ablation (SCA) of rat forebrain. Two and a half-month old male Wistar rats underwent SCA at the following coordinates: 2 mm before, 4 mm behind the bregma and 4 mm lateral to the midline, and to the depth of the white matter. After the surgery, rats were randomly divided according to treatment protocol into 6 groups: group L – treated with saline solution; LC1 group - treated with a combination of vitamin B1 (33 mg/kg/day), B6 (33 mg/kg/day) and B12 (0,5 mg/kg/day); LC2 group - treated with a combination of vitamin B2 (7.5 mg/kg/day) and B3 (500 mg/kg/day), LC group - treated with a combination of all five vitamins: B1, B2, B3, B6 and B12 in the above mentioned doses, LR group - received RBV (30 mg/kg/day); LCR group - treated with a combination of 5 B vitamins and RBV in the above doses. The first injection of vitamin B was given i.p. 15 minutes after the SCA, and then daily during next 14 days, while RBV was first administered 3 days after the SCA, once daily until the end of the experimental protocol. The effects of treatment on the recovery after SCA were followed by behavioral tests (beam walking test - BW test), while molecular changes were detected using RT-PCR, Western blot analysis and several immunohistochemical protocols...