Insect GDNF: TTC fusion protein improves delivery of GDNF to mouse CNS
Cecil B Day Laboratory for Neuromuscular Research, Department of Neurology, Massachusetts General Hospital, Charlestown, MA 02129, USA. Biochemical and Biophysical Research Communications
(Impact Factor: 2.3).
10/2009; 390(3):947-51. DOI: 10.1016/j.bbrc.2009.10.083
With a view toward improving delivery of exogenous glial cell line-derived neurotrophic factor (GDNF) to CNS motor neurons in vivo, we evaluated the bioavailability and pharmacological activity of a recombinant GDNF:tetanus toxin C-fragment fusion protein in mouse CNS. Following intramuscular injection, GDNF:TTC but not recombinant GDNF (rGDNF) produced strong GDNF immunostaining within ventral horn cells of the spinal cord. Intrathecal infusion of GDNF:TTC resulted in tissue concentrations of GDNF in lumbar spinal cord that were at least 150-fold higher than those in mice treated with rGDNF. While levels of immunoreactive choline acetyltransferase and GFRalpha-1 in lumbar cord were not altered significantly by intrathecal infusion of rGNDF, GDNF:TTC, or TTC, only rGDNF and GDNF:TTC caused significant weight loss following intracerebroventricular infusion. These studies indicate that insect cell-derived GDNF:TTC retains its bi-functional activity in mammalian CNS in vivo and improves delivery of GDNF to spinal cord following intramuscular- or intrathecal administration.
Available from: Liliana Mendieta
- "The C-terminal domain of tetanus toxin (Hc-TeTx) is used by the clostidial neurotoxin to bind to the neuronal membrane, after it is endocyted and carried through axons to arrive at the inhibitory glycinergic and GABAergic neurons of the spinal cord and brain stem. That is why the Hc-TeTx fragment has been proposed as a carrier to deliver molecules to the CNS (Payne et al., 2006; Larsen et al., 2006; Li et al., 2009; Ciriza et al., 2008). In addition, evidence suggests that the intramuscular administration of Hc-TeTx in rodents results in the delivery of the fragment to the brain. "
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ABSTRACT: We have previously shown that the intrastriatal injection of the C-terminal domain of tetanus toxin (Hc-TeTx) protects the nigrostriatal-dopaminergic pathways and improves motor behavior in hemiparkinsonism-rat models caused by MPP(+) (1-methyl-4-phenylpyridinium). Here we have investigated the protective effects of the intramuscular application of the Hc-TeTx on motor asymmetry and neurodegeneration in the striatum of 6-hydroxydopamine (6-OHDA)-treated rats. Adult male rats were intramuscularly injected with the recombinant Hc-TeTx protein (0.1-20μg/kg, daily) 3days before the stereotaxic injection of 6-OHDA into the left striatum. Our results showed that the motor-improvement functions were extended for 4weeks in all Hc-TeTx-treated groups, obtaining the maximum performance with the highest dose of Hc-TeTx (20μg/kg). The improvements found were 97%, 87%, and 70% in the turning behavior, stepping test, and cylinder test, respectively. The striatal levels of dopamine and its metabolites did not vary compared to the control group. Moreover, the peripheral treatment with Hc-TeTx in rats prevents, for 30days, the neurodegeneration in the striatum caused by the toxicity of the 6-OHDA. Our results lead us to believe that the Hc-TeTx could be a potential therapeutic agent in pathologies caused by impairment of dopaminergic innervations such as Parkinson's disease.
Available from: Janne Markus Toivonen
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ABSTRACT: In many neurological disorders strategies for a specific delivery of a biological activity from the periphery to the central nervous system (CNS) remains a considerable challenge for successful therapy. Reporter assays have established that the non-toxic C-fragment of tetanus toxin (TTC), provided either as protein or encoded by non-viral naked DNA plasmid, binds pre-synaptic motor neuron terminals and can facilitate the retrograde axonal transport of desired therapeutic molecules to the CNS. Alleviated symptoms in animal models of neurological diseases upon delivery of therapeutic molecules offer a hopeful prospect for TTC therapy. This review focuses on what has been learned on TTC-mediated neuronal targeting, and discusses the recent discovery that, instead of being merely a carrier molecule, TTC itself may well harbor neuroprotective properties.
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ABSTRACT: This study examines the prevalence of oral mucosal lesions and conditions among Irish addiction treatment centre residents and explores the feasibility and acceptability of a targeted oral cancer screening programme for such individuals. Four alcohol addiction treatment centres were visited periodically over a 12-month period. Two hundred and twenty residents (78% of 283 targeted) were interviewed regarding their alcohol, tobacco and drug habits (type, quantity, duration), and attitudes to dental care. Comprehensive oral examinations were performed. All potentially sinister soft tissue lesions/symptoms were referred for further investigation. Data analysis utilised SPSS-18. Ten participants who denied a history of alcohol/drug addiction were excluded from the main study. Remaining 210 participants comprised 148 males (70%) and 62 females (30%), ranging from 18 to 73 years of age, (mean 37.65; S.D. 13.82); 60% were under 40. High rates of tobacco and alcohol usage were recorded, 53% reported dual addiction (drug+alcohol), 44% alcohol only, 3% drug only. The prevalence of mucosal abnormalities was 29% with 84 mucosal abnormalities/symptoms detected in 61 subjects, comprising 28 extra-oral lesions/symptoms and 56 intra-oral lesions. Residents with mucosal abnormalities were significantly older (mean 41.8 years; S.D. 14.3) than those without such lesions (mean 35.95; S.D. 13.3), (p<0.05). Highest prevalences were noted for candidiasis (3.8%), facial scaring/laceration (3.8%), intra-oral lumps/swellings (2.9%), lymphadenopathy (2.9%) and hoarseness (1.9%). Four red areas suggestive of erythroplasia and two leukoplakic lesions were detected. Study addresses the paucity of data on the prevalence of oral mucosal lesions in addicted persons in Southern Ireland. Thirteen extra-oral lesions/symptoms and 19 intra-oral lesions were potentially significant. Despite the relatively poor follow-up compliance rate (33%), two premalignant lesions were confirmed in the main study group, yielding a detection rate of 0.9%. Results suggest that an oral cancer screening programme targeted at individuals in addiction treatment centres may provide a feasible way to access persons with a history of tobacco and alcohol abuse. A high rate of untreated disease and emergency only attendance was seen in this study suggesting a lack of engagement with GDP services. Opportunistic screening in primary care is therefore unlikely to capture this cohort. Inclusion of oral cancer screening in the routine medical examination given to residents of addiction treatment centres may provide an efficient and effective way to detect potentially malignant lesions in these high-risk individuals.
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