Stéphane Palfi

Clinicopathological findings following intraventricular glial-derived neurotrophic factor treatment in a patient with Parkinson's disease

As part of a safety and tolerability study, a 65‐year‐old man with Parkinsons disease (PD) received monthly intracerebroventricular injections of glial‐derived neurotrophic factor (GDNF). His parkinsonism continued to worsen following intracerebroventricular GDNF treatment. Side effects included nausea, loss of appetite, tingling, Lhermittes sign, intermittent hallucinations, depression, and inappropriate sexual conduct. There was no evidence of significant regeneration of nigrostriatal neurons or intraparenchymal diffusion of the intracerebroventricular GDNF to relevant brain regions. Alternative GDNF delivery systems should be explored.

Long-term safety and tolerability of ProSavin, a lentiviral vector-based gene therapy for Parkinson's disease: a dose escalation, open-label, phase 1/2 trial

BACKGROUNDnParkinsons disease is typically treated with oral dopamine replacement therapies; however, long-term treatment leads to motor complications and, occasionally, impulse control disorders caused by intermittent stimulation of dopamine receptors and off-target effects, respectively. We aimed to assess the safety, tolerability, and efficacy of bilateral, intrastriatal delivery of ProSavin, a lentiviral vector-based gene therapy aimed at restoring local and continuous dopamine production in patients with advanced Parkinsons disease.nnnMETHODSnWe undertook a phase 1/2 open-label trial with 12-month follow-up at two study sites (France and UK) to assess the safety and efficacy of ProSavin after bilateral injection into the putamen of patients with Parkinsons disease. All patients were then enrolled in a separate open-label follow-up study of long-term safety. Three doses were assessed in separate cohorts: low dose (1·9×10(7) transducing units [TU]); mid dose (4·0×10(7) TU); and high dose (1×10(8) TU). Inclusion criteria were age 48-65 years, disease duration 5 years or longer, motor fluctuations, and 50% or higher motor response to oral dopaminergic therapy. The primary endpoints of the phase 1/2 study were the number and severity of adverse events associated with ProSavin and motor responses as assessed with Unified Parkinsons Disease Rating Scale (UPDRS) part III (off medication) scores, at 6 months after vector administration. Both trials are registered at ClinicalTrials.gov, NCT00627588 and NCT01856439.nnnFINDINGSn15 patients received ProSavin and were followed up (three at low dose, six mid dose, six high dose). During the first 12 months of follow-up, 54 drug-related adverse events were reported (51 mild, three moderate). Most common were increased on-medication dyskinesias (20 events, 11 patients) and on-off phenomena (12 events, nine patients). No serious adverse events related to the study drug or surgical procedure were reported. A significant improvement in mean UPDRS part III motor scores off medication was recorded in all patients at 6 months (mean score 38 [SD 9] vs 26 [8], n=15, p=0·0001) and 12 months (38 vs 27 [8]; n=15, p=0·0001) compared with baseline.nnnINTERPRETATIONnProSavin was safe and well tolerated in patients with advanced Parkinsons disease. Improvement in motor behaviour was observed in all patients.nnnFUNDINGnOxford BioMedica.

Lentiviral Gene Transfer to the Nonhuman Primate Brain

Lentiviral vectors infect quiescent cells and allow for the delivery of genes to discrete brain regions. The present study assessed whether stable lentiviral gene transduction can be achieved in the monkey nigrostriatal system. Three young adult Rhesus monkeys received injections of a lentiviral vector encoding for the marker gene beta galatosidase (beta Gal). On one side of the brain, each monkey received multiple lentivirus injections into the caudate and putamen. On the opposite side, each animal received a single injection aimed at the substantia nigra. The first two monkeys were sacrificed 1 month postinjection, while the third monkey was sacrificed 3 months postinjection. Robust incorporation of the beta Gal gene was seen in the striatum of all three monkeys. Stereological counts revealed that 930,218; 1,192,359; and 1,501,217 cells in the striatum were beta Gal positive in monkeys 1 (n = 2) and 3 (n = 1) months later, respectively. Only the third monkey had an injection placed directly into the substantia nigra and 187,308 beta Gal-positive cells were identified in this animal. The injections induced only minor perivascular cuffing and there was no apparent inflammatory response resulting from the lentivirus injections. Double label experiments revealed that between 80 and 87% of the beta Gal-positive cells were neurons. These data indicate that robust transduction of striatal and nigral cells can occur in the nonhuman primate brain for up to 3 months. Studies are now ongoing testing the ability of lentivirus encoding for dopaminergic trophic factors to augment the nigrostriatal system in nonhuman primate models of Parkinsons disease.

Safety and tolerability assessment of intrastriatal neural allografts in five patients with Huntington's disease

This study describes issues related to the safety and tolerability of fetal striatal neural allografts as assessed in five patients with Huntingtons disease. Huntingtons disease (HD) is characterized by motor, cognitive, and behavioral disturbances. The latter include psychological disturbances and, as a consequence, we took particular care to analyze behavioral changes, in addition to the usual safety follow-up. We conducted multidisciplinary follow-up at least 2 years before and 1 year after grafting. Psychological care extended to close relatives. The grafting procedure itself was altogether safe and uneventful, and there were no apparent clinical deleterious effects for 1 year. The immunosuppressive treatment, however, was complicated by various problems (irregular compliance, errors of handling, side effects). Direct psychological consequences of the transplantation procedure were rare and not worrisome, although mood alteration requiring treatment was observed in one patient. Indirectly, however, the procedure required patients and relatives to accept constraints that tended to complicate familial situations already marred by aggressivity and depression. All patients and close relatives expressed major expectations, in spite of our strong and repeated cautioning. It is clearly important to be aware of these particular conditions since they may eventually translate into psychological difficulties in coping with the long-term clinical outcome of the procedure, if not beneficial. Despite an overall good tolerance, therefore, this follow-up calls for caution regarding the involvement of HD patients in experimental surgical protocols.

Functional Recovery in a Primate Model of Parkinson's Disease following Motor Cortex Stimulation

A concept in Parkinsons disease postulates that motor cortex may pattern abnormal rhythmic activities in the basal ganglia, underlying the genesis of observed motor symptoms. We conducted a preclinical study of electrical interference in the primary motor cortex using a chronic MPTP primate model in which dopamine depletion was progressive and regularly documented using 18F-DOPA positron tomography. High-frequency motor cortex stimulation significantly reduced akinesia and bradykinesia. This behavioral benefit was associated with an increased metabolic activity in the supplementary motor area as assessed with 18-F-deoxyglucose PET, a normalization of mean firing rate in the internal globus pallidus (GPi) and the subthalamic nucleus (STN), and a reduction of synchronized oscillatory neuronal activities in these two structures. Motor cortex stimulation is a simple and safe procedure to modulate subthalamo-pallido-cortical loop and alleviate parkinsonian symptoms without requiring deep brain stereotactic surgery.

Restoration of Cognitive and Motor Functions by Ciliary Neurotrophic Factor in a Primate Model of Huntington' s Disease

Huntingtons disease (HD) is an inherited disorder characterized by cognitive impairments, motor deficits, and progressive dementia. These symptoms result from progressive neurodegenerative changes mainly affecting the neostriatum. This pathology is fatal in 10 to 20 years and there is currently no treatment for HD. Early in the course of the disease, initial clinical manifestations are due to striatal neuronal dysfunction, which is later followed by massive neuronal death. A major therapeutic objective is therefore to reverse striatal dysfunction prior to cell death. Using a primate model reproducing the clinical features and the progressive neuronal degeneration typical of HD, we tested the therapeutic effects of direct intrastriatal infusion of ciliary neurotrophic factor (CNTF). To achieve a continuous delivery of CNTF over the full period of evaluation, we took advantage of the macroencapsulation technique. Baby hamster kidney (BHK) cells previously engineered to produce human CNTF were encapsulated into semipermeable membranes and implanted bilaterally into striata. We show here that intracerebral delivery of low doses of CNTF at the onset of symptoms not only protects neurons from degeneration but also restores neostriatal functions. CNTF-treated primates recovered, in particular, cognitive and motor functions dependent on the anatomofunctional integrity of frontostriatal pathways that were distinctively altered in this HD model. These results support the hypothesis that CNTF infusion into the striatum of HD patients not only could block the degeneration of neurons but also alleviated motor and cognitive symptoms associated with persistent neuronal dysfunction.

Contribution of gap junctional communication between tumor cells and astroglia to the invasion of the brain parenchyma by human glioblastomas

BackgroundGliomas are intraparenchymally metastatic tumors, invading the brain in a non-destructive way that suggests cooperation between glioma cells and their environment. Recent studies using an engineered rodent C6 tumor cell line have pointed to mechanisms of invasion that involved gap junctional communication (GJC), with connexin 43 as a substrate. We explored whether this concept may have clinical relevance by analyzing the participation of GJC in human glioblastoma invasion.ResultsThree complementary in vitro assays were used: (i) seeding on collagen IV, to analyze homocellular interactions between tumor cells (ii) co-cultures with astrocytes, to study glioblastoma/astrocytes relationships and (iii) implantation into organotypic brain slice cultures, that mimic the three-dimensional parenchymal environment. Carbenoxolone, a potent blocker of GJC, inhibited cell migration in the two latter models. It paradoxically increased it in the first one. These results showed that homocellular interaction between tumor cells supports intercellular adhesion, whereas heterocellular glioblastoma/astrocytes interactions through functional GJC conversely support tumor cell migration. As demonstrated for the rodent cell line, connexin 43 may be responsible for this heterocellular functional coupling. Its levels of expression, high in astrocytes, correlated positively with invasiveness in biopsied tumors.Conclusionsour results underscore the potential clinical relevance of the concept put forward by other authors based on experiments with a rodent cell line, that glioblastoma cells use astrocytes as a substrate for their migration by subverting communication through connexin 43-dependent gap junctions.

FXTAS: new insights and the need for revised diagnostic criteria

Objective:Fragile X–associated tremor ataxia syndrome (FXTAS) is defined by FMR1 premutation, cerebellar ataxia, intentional tremor, and middle cerebellar peduncle (MCP) hyperintensities. We delineate the clinical, neurophysiologic, and morphologic characteristics of FXTAS. Methods:Clinical, morphologic (brain MRI, 123I-ioflupane SPECT), and neurophysiologic (tremor recording, nerve conduction studies) study in 22 patients with FXTAS, including 4 women. Results:A total of 43% of patients had no family history of fragile X syndrome (FXS), which contrasts with previous FXTAS series. A total of 86% of patients had tremor and 81% peripheral neuropathy. We identified 3 electroclinical tremor patterns: essential-like (35%), cerebellar (29%), and parkinsonian (12%). Two electrophysiologic patterns evocative of non-length-dependent (56%) and length-dependent sensory neuropathy (25%) were identified. Corpus callosum splenium (CCS) hyperintensity was as frequent (68%) as MCP hyperintensities (64%). Sixty percent of patients had parkinsonism and 47% abnormal 123I-ioflupane SPECT. Unified Parkinsons Disease Rating Scale motor score was correlated to abnormal 123I-ioflupane SPECT (p = 0.02) and to CGG repeat number (p = 0.0004). Scale for the assessment and rating of ataxia correlated with dentate nuclei hyperintensities (p = 0.03) and CCS hyperintensity was a marker of severe disease progression (p = 0.04). Conclusions:We recommend to include in the FXTAS testing guidelines both CCS hyperintensity and peripheral neuropathy and to consider them as new major radiologic and minor clinical criterion, respectively, for the diagnosis of FXTAS. FXTAS should also be considered in women or when tremor, MCP hyperintensities, or family history of FXS are lacking. Our study broadens the spectrum of tremor, peripheral neuropathy, and MRI abnormalities in FXTAS, hence revealing the need for revised criteria. GLOSSARYAcc: accelerometerCCS: corpus callosum spleniumCMAP: compound muscle action potentialDD: disease durationDL: distal latencyDRG: dorsal root gangliaET: essential tremorF-WL: F-wave latencyFAB: Frontal Assessment BatteryFLAIR: fluid-attenuated inversion recoveryFTMa: Fahn-Tolosa-Marin adapted tremor rating scale, part AFXS: fragile X syndromeFXTAS: fragile X–associated tremor ataxia syndromeLL: lower limbMCP: middle cerebellar peduncleMMSE: Mini-Mental State ExaminationMNCV: motor nerve conduction velocityNCS: nerve conduction studyPD: Parkinson diseasePOI: primary ovarian insufficiencySARA: Scale for the Assessment and Rating of AtaxiaSNAP: sensory nerve action potentialSNN: sensory neuronopathyUL: upper limbUPDRS-III: Unified Parkinsons Disease Rating Scale motorObjective: Fragile X–associated tremor ataxia syndrome (FXTAS) is defined by FMR1 premutation, cerebellar ataxia, intentional tremor, and middle cerebellar peduncle (MCP) hyperintensities. We delineate the clinical, neurophysiologic, and morphologic characteristics of FXTAS. Methods: Clinical, morphologic (brain MRI, 123I-ioflupane SPECT), and neurophysiologic (tremor recording, nerve conduction studies) study in 22 patients with FXTAS, including 4 women. Results: A total of 43% of patients had no family history of fragile X syndrome (FXS), which contrasts with previous FXTAS series. A total of 86% of patients had tremor and 81% peripheral neuropathy. We identified 3 electroclinical tremor patterns: essential-like (35%), cerebellar (29%), and parkinsonian (12%). Two electrophysiologic patterns evocative of non-length-dependent (56%) and length-dependent sensory neuropathy (25%) were identified. Corpus callosum splenium (CCS) hyperintensity was as frequent (68%) as MCP hyperintensities (64%). Sixty percent of patients had parkinsonism and 47% abnormal 123I-ioflupane SPECT. Unified Parkinsons Disease Rating Scale motor score was correlated to abnormal 123I-ioflupane SPECT (p = 0.02) and to CGG repeat number (p = 0.0004). Scale for the assessment and rating of ataxia correlated with dentate nuclei hyperintensities (p = 0.03) and CCS hyperintensity was a marker of severe disease progression (p = 0.04). Conclusions: We recommend to include in the FXTAS testing guidelines both CCS hyperintensity and peripheral neuropathy and to consider them as new major radiologic and minor clinical criterion, respectively, for the diagnosis of FXTAS. FXTAS should also be considered in women or when tremor, MCP hyperintensities, or family history of FXS are lacking. Our study broadens the spectrum of tremor, peripheral neuropathy, and MRI abnormalities in FXTAS, hence revealing the need for revised criteria.

Encapsulated GDNF-producing C2C12 cells for Parkinson's disease: a pre-clinical study in chronic MPTP-treated baboons

Glial cell line-derived neurotrophic factor (GDNF), a potent neurotrophic factor with restorative effects in a variety of rodent and primate models of Parkinsons disease (PD), could be of therapeutic value to PD. In this study, we show that intraventricular chronic infusion of low doses of GDNF using encapsulated genetically engineered C2C12 cells can exert: (1) transient recovery of motor deficits (hypokinesia); (2) significant protection of intrinsic striatal dopaminergic function in the immediate vicinity of the site of implantation of the capsule in the caudate nucleus, and (3) significant-long-lasting-neurotrophic properties at the nigral level with an increase volume of the cell bodies. These observations confirm the potent neurorestorative potential of GDNF in PD and the safety/efficacy of the encapsulation technology as a means to deliver in situ this neurotrophic cytokine even using an intraventricular approach.

Cyclosporin A protects striatal neurons in vitro and in vivo from 3-nitropropionic acid toxicity

The neuroprotective properties of cyclosporin A (CsA) are mediated by its ability to prevent mitochondrial permeability transition during exposure to high levels of calcium or oxidative stress. By using the mitochondrial toxin 3‐nitropropionic acid (3NP), the present study assessed whether CsA could protect striatal neurons in vitro and in vivo. In vitro, 3NP produced a 20–30% reduction of striatal glutamic acid decarboxylase‐immunoreactive (GAD‐ir) neurons. A single treatment with CsA protected GAD‐ir neurons from 3NP toxicity at lower (0.2 or 1.0 μM), but not at higher (5.0 μM) doses. Similar findings were seen when the cultures were treated twice with cyclosporin. In vivo experiments used the Lewis rat model of Huntingtons disease (HD) in which a low 3NP dose was delivered subcutaneously through an osmotic minipump. Rats received unilateral or bilateral intrastriatal saline injections to disrupt the blood‐brain barrier (BBB) and facilitate CsA reaching vulnerable neurons. In the first experiment, CsA treated 3NP‐lesioned rats displayed significantly more dopamine‐and adenosine‐3`,5`‐monophosphate‐regulated phosphoprotein (DARPP32‐ir) neurons ipsilateral to BBB disruption compared to the contralateral intact striatum, indicating that disruption of the BBB maybe necessary for CsAs neuroprotective effects. In the second experiment, stereological counts of DARPP32‐ir neurons revealed that CsA protected striatal neurons in a dose‐dependent manner following bilateral disruption of the striatal BBB. Rats treated with the higher (15 or 20 mg/kg) but not lower (5 mg/kg) doses of CsA displayed greater numbers of DARRP32‐ir striatal neurons relative to vehicle‐treated 3NP‐lesioned rats. Thus, under conditions in which CsA can gain access to striatal neurons, significant protection from 3NP toxicity is observed. Therefore, CsA or more lipophilic analogues of this compound, may be of potential therapeutic benefit by protecting vulnerable neurons from the primary pathological event observed in HD. J. Comp. Neurol. 425:471–478, 2000.