FGF-2 is required to prevent astrogliosis in the facial nucleus after facial nerve injury and mechanical stimulation of denervated vibrissal muscles
JOURNAL OF BIOMEDICAL RESEARCH, cilt.30, sa.2, ss.142-148, 2016 (ESCI)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 30 Sayı: 2
- Basım Tarihi: 2016
- Doi Numarası: 10.7555/jbr.30.20140042
- Dergi Adı: JOURNAL OF BIOMEDICAL RESEARCH
- Derginin Tarandığı İndeksler: Emerging Sources Citation Index (ESCI), Scopus
- Sayfa Sayıları: ss.142-148
- Anahtar Kelimeler: FGF-2, facial nerve, axotomy, astrogliosis, whisking function, polyinnervation, FIBRILLARY ACIDIC PROTEIN, MANUAL STIMULATION, ADULT-RATS, REACTIVE ASTROCYTES, WHISKING FUNCTION, RECOVERY, LESIONS, NEURONS, CORTEX, MICE
- Akdeniz Üniversitesi Adresli: Evet
Özet
Recently, we have shown that manual stimulation of paralyzed vibrissal muscles after facial-facial anastomosis reduced the poly-innervation of neuromuscular junctions and restored vibrissal whisking. Using gene knock outs, we found a differential dependence of manual stimulation effects on growth factors. Thus, insulin-like growth factor- 1 and brain-derived neurotrophic factor are required to underpin manual stimulation-mediated improvements, whereas FGF-2 is not. The lack of dependence on FGF-2 in mediating these peripheral effects prompted us to look centrally, i. e. within the facial nucleus where increased astrogliosis after facial-facial anastomosis follows "synaptic stripping". We measured the intensity of Cy3-fluorescence after immunostaining for glial fibrillary acidic protein (GFAP) as an indirect indicator of synaptic coverage of axotomized neurons in the facial nucleus of mice lacking FGF-2 (FGF-2(-/-) mice). There was no difference in GFAP-Cy3-fluorescence (pixel number, gray value range 17-103) between intact wildtype mice (2.12 +/- 0.37x10(7)) and their intact FGF-2(-/-) counterparts (2.12 +/- 0.27x10(7)) nor after facial-facial anastomosis + handling (wildtype: 4.06 +/- 0.32x10(7); FGF-2(-/-) : 4.39 +/- 0.17x10(7)). However, after facial-facial anastomosis, GFAP-Cy3-fluorescence remained elevated in FGF-2(-/-) -animals (4.54 +/- 0.12x10(7)), whereas manual stimulation reduced the intensity of GFAP-immunofluorescence in wild type mice to values that were not significantly different from intact mice (2.63 +/- 0.39x10). We conclude that FGF-2 is not required to underpin the beneficial effects of manual stimulation at the neuro-muscular junction, but it is required to minimize astrogliosis in the brainstem and, by implication, restore synaptic coverage of recovering facial motoneurons.