Implanted fibroblasts genetically engineered to produce brain-derived neurotrophic factor prevent 1-methyl-4-phenylpyridinium toxicity to dopaminergic neurons in the rat.

Abstract

The trophism of brain-derived neurotrophic factor (BDNF) for dopaminergic cells in culture has led to signifint interest in the role of BDNF in the etiology and potential treatment of Parkinson disease. Previous in .vo investIgation of BDNF delivery to axotomized anta nira dopaminergic neurons in the adult rat has shown no protective effect. In this study, we produced nigral degeneration by insing l-methyl-4-phenylpyrldinlum (MPP+), a mitochondrial complex I inhibitor and the active metabolite of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), into the rat striatum. The subsequent loss of nigral neurons was presumably due to mitochondrial toxicity after MPP+ uptake and retrograde transport to the substantla nira. We engired immortalzed rat fibroblasts to secrete human BDNF and Implanted these cells near the substantia nigra 7 days before striatal MPP+ infusion. We found that BDNF-secreting fibroblasts markedly increased nI do ergic neuronal survival when compared to control fibroblast Implants. The observation that BDNF prevents MNPTP-induced dopaminergc neuronal degeneration in the adult brain has sgncance for the reatment of neurodegenerative disorders, whih may involve mitochondrial dysfunction, such as Parkinson disease.The range of neuroprotective effects for any putative neurotrophic molecule must be determined in in vivo models of neurodegeneration (1-8) before practical application of neurotrophic factor neuroprotection can be contemplated (9). Of particular interest are neurotrophic factors found to protect in vivo against neuronal death caused by mechanisms similar to those thought to occur in human neurodegenerative disorders, such as nerve growth factor (NGF) protection against Huntington disease-like lesions ofthe striatum (7,8) or ciliary neurotrophic factor protection in a mouse model of motoneuron degeneration (10). Brain-derived neurotrophic factor (BDNF) (11,12) promotes the survival offetal mesencephalic dopaminergic cells in culture (13). In vivo, BDNF protects cholinergic neurons from degeneration after fimbria-fornix lesions (4) and motoneurons from degeneration after axotomy (5, 6); however, BDNF does not rescue axotomized substantia nigra compacta (SNC) dopaminergic neurons after axotomy (4).However, the cellular insults that cause some human neurodegenerative diseases may be only partially modeled by axotomy-induced cell death (14-16). Other insults to cellular integrity, such as impaired energy metabolism, may more accurately model the degeneration seen in Huntington disease or Parkinson disease (17)(18)(19)(20). Indeed, evidence for abnormalities in mitochondrial function has been found in patients with both of these disorders (21,22 Seed, Massachusetts General Hospital) as described (25) and as shown in Fig. 1A. Rat I BDNF subclones were selected under G418 and then screened for their level ofBDNF mRNA production by Northern blot analysis and for their level of BDNF secretion as determined by an in vitro rat dorsal root ganglion neurite outgrowth bioassay, as described (2...

Caloric restriction increases neurotrophic factor levels and attenuates neurochemical and behavioral deficits in a primate model of Parkinson's disease

“…Moreover, the amount of BDNF available to DA neurons may be decreased in PD patients (37), and BDNF can protect DA neurons in animal and cell culture models of PD (38)(39)(40). We therefore quantified BDNF protein levels by ELISA analysis in tissue samples from the left and right CNs of each monkey.…”

How to make a midbrain dopaminergic neuron

“…The survival of mDA neurons in vitro and in animal models of PD is regulated by several families of neurotrophic factors, including the transforming growth factor family (TGFβ2/3) (Poulsen et al, 1994;Roussa et al, 2009); members of the neurotrophin family, such as brain-derived neurotrophic factor (BDNF) (Frim et al, 1994;Hyman et al, 1991); glial cell-linederived neurotrophic factor (GDNF) (Akerud et al, 2001;Arenas et al, 1995;Beck et al, 1995;Choi-Lundberg et al, 1997;Gash et al, 1996;Kordower et al, 2000;Lin et al, 1993;Rosenblad et al, 1998;Tomac et al, 1995); other members of the GDNF family, such as neurturin or persephin (Akerud et al, , 2002Horger et al, 1998;Rosenblad et al, 1999Rosenblad et al, , 2000; and a novel family formed by mesencephalic astrocyte-derived neurotrophic factor (MANF) and conserved dopamine neurotrophic factor (CDNF or Armetl1) (Lindholm et al, 2007;Petrova et al, 2003;Voutilainen et al, 2009).…”

Treatment of Parkinson’s Disease with Trophic Factors

“…23,24 Fibroblasts capable of secreting transgenic human BDNF that were implanted near the substantia nigra of rats prior to striatal MPPϩ infusions decreased destruction of dopamine neurons by 86%. 25 Intrastriatal injection of BDNF in a rat model prior to unilateral 6-OHDA lesioning reduced destruction of dopamine neurons in the substantia nigra and decreased the apomorphine-induced rotation (a measure of asymmetrical dopaminergic function). 26 Conversely, a knock down of the BDNF receptor, trkB, and the related NT-3 receptor, trkC, result in a reduced number of dopaminergic neurons in the substantia nigra, induced accumulation of ␣-synuclein in remaining dopamine neurons, and reduced tyrosine hydroxylase immunoreactivity in the striatum.…”