Gianluigi Mancardi

Mesenchymal stem cells effectively modulate pathogenic immune response in experimental autoimmune encephalomyelitis

To evaluate the ability of mesenchymal stem cells (MSCs), a subset of adult stem cells from bone marrow, to cure experimental autoimmune encephalomyelitis.

Human Mesenchymal Stem Cells Promote Survival of T Cells in a Quiescent State

Mesenchymal stem cells (MSC) are part of the bone marrow that provides signals supporting survival and growth of bystander hematopoietic stem cells (HSC). MSC modulate also the immune response, as they inhibit proliferation of lymphocytes. In order to investigate whether MSC can support survival of T cells, we investigated MSC capacity of rescuing T lymphocytes from cell death induced by different mechanisms. We observed that MSC prolong survival of unstimulated T cells and apoptosis‐prone thymocytes cultured under starving conditions. MSC rescued T cells from activation induced cell death (AICD) by downregulation of Fas receptor and Fas ligand on T cell surface and inhibition of endogenous proteases involved in cell death. MSC dampened also Fas receptor mediated apoptosis of CD95 expressing Jurkat leukemic T cells. In contrast, rescue from AICD was not associated with a significant change of Bcl‐2, an inhibitor of apoptosis induced by cell stress. Accordingly, MSC exhibited a minimal capacity of rescuing Jurkat cells from chemically induced apoptosis, a process disrupting the mitochondrial membrane potential regulated by Bcl‐2. These results suggest that MSC interfere with the Fas receptor regulated process of programmed cell death. Overall, MSC can inhibit proliferation of activated T cells while supporting their survival in a quiescent state, providing a model of their activity inside the HSC niche.

Autologous haematopoietic stem-cell transplantation in multiple sclerosis

Intense immunosuppression followed by autologous haematopoietic stem-cell transplantation has been assessed over the past few years as a possible new therapeutic strategy in severe forms of multiple sclerosis. Pioneering studies began in 1995, and since then, more than 400 patients worldwide have been treated with this procedure. Small uncontrolled studies show that about 60-70% of treated cases do not progress in the follow-up period of at least 3 years. Transplant-related mortality, which was 5-6% in the first reported series, has reduced in the past 5 years to 1-2%. Relapses dramatically decrease and inflammatory MRI activity is almost completely suppressed. Autologous haematopoietic stem-cell transplantation is associated with qualitative immunological changes in the blood, suggesting that, beyond its immunosuppressive potential, it could also have some beneficial effect for the resetting of the immune system. Patients with severe, rapidly worsening multiple sclerosis who are unresponsive to approved therapies could be candidates for this treatment, but its clinical efficacy has still to be shown in large, prospective, controlled studies.

Clinical characteristics of patients with familial amyotrophic lateral sclerosis carrying the pathogenic GGGGCC hexanucleotide repeat expansion of C9ORF72

A large hexanucleotide (GGGGCC) repeat expansion in the first intron of C9ORF72, a gene located on chromosome 9p21, has been recently reported to be responsible for ~40% of familial amyotrophic lateral sclerosis cases of European ancestry. The aim of the current article was to describe the phenotype of amyotrophic lateral sclerosis cases carrying the expansion by providing a detailed clinical description of affected cases from representative multi-generational kindreds, and by analysing the age of onset, gender ratio and survival in a large cohort of patients with familial amyotrophic lateral sclerosis. We collected DNA and analysed phenotype data for 141 index Italian familial amyotrophic lateral sclerosis cases (21 of Sardinian ancestry) and 41 German index familial amyotrophic lateral sclerosis cases. Pathogenic repeat expansions were detected in 45 (37.5%) patients from mainland Italy, 12 (57.1%) patients of Sardinian ancestry and nine (22.0%) of the 41 German index familial amyotrophic lateral sclerosis cases. The disease was maternally transmitted in 27 (49.1%) pedigrees and paternally transmitted in 28 (50.9%) pedigrees (P = non-significant). On average, children developed disease 7.0 years earlier than their parents [children: 55.8 years (standard deviation 7.9), parents: 62.8 (standard deviation 10.9); P = 0.003]. Parental phenotype influenced the type of clinical symptoms manifested by the child: of the 13 cases where the affected parent had an amyotrophic lateral sclerosis-frontotemporal dementia or frontotemporal dementia, the affected child also developed amyotrophic lateral sclerosis-frontotemporal dementia in nine cases. When compared with patients carrying mutations of other amyotrophic lateral sclerosis-related genes, those with C9ORF72 expansion had commonly a bulbar onset (42.2% compared with 25.0% among non-C9ORF72 expansion cases, P = 0.03) and cognitive impairment (46.7% compared with 9.1% among non-C9ORF72 expansion cases, P = 0.0001). Median survival from symptom onset among cases carrying C9ORF72 repeat expansion was 3.2 years lower than that of patients carrying TARDBP mutations (5.0 years; 95% confidence interval: 3.6-7.2) and longer than those with FUS mutations (1.9 years; 95% confidence interval: 1.7-2.1). We conclude that C9ORF72 hexanucleotide repeat expansions were the most frequent mutation in our large cohort of patients with familial amyotrophic lateral sclerosis of Italian, Sardinian and German ancestry. Together with mutation of SOD1, TARDBP and FUS, mutations of C9ORF72 account for ~60% of familial amyotrophic lateral sclerosis in Italy. Patients with C9ORF72 hexanucleotide repeat expansions present some phenotypic differences compared with patients with mutations of other genes or with unknown mutations, namely a high incidence of bulbar-onset disease and comorbidity with frontotemporal dementia. Their pedigrees typically display a high frequency of cases with pure frontotemporal dementia, widening the concept of familial amyotrophic lateral sclerosis.

Neuroprotective mesenchymal stem cells are endowed with a potent antioxidant effect in vivo.

Experimental autoimmune encephalomyelitis (EAE), an animal model for human multiple sclerosis, is characterized by demyelination, inflammation and neurodegeneration of CNS in which free radicals play a role. Recently, the efficacy of murine mesenchimal stem cells (MSCs) as treatment of EAE induced in mice by the encephalitogenic peptide MOG(35–55) was demonstrated. The present study analyzed some markers of oxidative stress, inflammation/degeneration and apoptosis such as metallothioneins (MTs), antioxidant enzymes (superoxide dismutase, catalase and glutathione‐S‐transferase), poly(ADP‐ribose) polymerase‐1 and p53 during EAE progression and following MSC treatment. Expression of the three brain MT isoforms increased significantly in EAE mice compared with healthy controls, but while expression of MT‐1 and MT‐3 increased along EAE course, MT‐2 was up‐regulated at the onset, but returned to levels similar to those of controls in chronic phase. The changes in the transcription and activity of the antioxidant enzymes and in expression of poly(ADP‐ribose) polymerase‐1 and p53 showed the same kinetics observed for MT‐1 and MT‐3 during EAE. Interestingly, i.v. administration of MSCs reduced the EAE‐induced increases in levels/activities of all these proteins. These results support an antioxidant and neuroprotective activity for MSCs that was also confirmed in vitro on neuroblastoma cells exposed to an oxidative insult.

Computer-aided retraining of memory and attention in people with multiple sclerosis: A randomized, double-blind controlled trial

CONTEXT Cognitive compromise is one of the main contributing factors to activity and participation restrictions in people with multiple sclerosis (MS). Computer-aided programs are used for retraining memory and attention, but data on the efficacy of these interventions are scarce. OBJECTIVE To assess the efficacy of computer-aided retraining of memory and attention in people with MS impaired in these abilities. DESIGN AND SETTING Randomized, double-blind, controlled trial. PARTICIPANTS Outpatients (n=82) with subjective complaints of poor attention or memory, confirmed by a score <80th percentile in at least two tests of the Brief Repeatable Battery of Neuropsychological Tests (BRBNT). INTERVENTIONS Participants were randomized to two computer-assisted retraining interventions: memory and attention (study arm), and visuo-constructional and visuo-motor coordination (control arm). Both groups received 16 training sessions over 8 weeks. OUTCOME MEASURES Improvement of 20% or more in at least two BRBNT test scores at 8 weeks compared to baseline (primary end point). Changes in depression and health-related quality of life. RESULTS An improvement occurred in 45% of study patients vs. 43% of control patients (odds ratio 1.07, 95% confidence interval 0.44-2.64). The study treatment was better than the control treatment only on the word list generation test (p=0.016). CONCLUSIONS This trial does not support the efficacy of specific memory and attention retraining in MS.

Myelin/Oligodendrocyte Glycoprotein-Induced Autoimmune Encephalomyelitis in Common Marmosets: The Encephalitogenic T Cell Epitope pMOG24–36 Is Presented by a Monomorphic MHC Class II Molecule

Immunization of common marmosets (Callithrix jacchus) with a single dose of human myelin in CFA, without administration of Bordetella pertussis, induces a form of autoimmune encephalomyelitis (EAE) resembling in its clinical and pathological expression multiple sclerosis in humans. The EAE incidence in our outbred marmoset colony is 100%. This study was undertaken to assess the genetic and immunological basis of the high EAE susceptibility. To this end, we determined the separate contributions of immune reactions to myelin/oligodendrocyte glycoprotein (MOG) and myelin basic protein to the EAE induction. Essentially all pathological features of myelin-induced EAE were also found in animals immunized with MOG in CFA, whereas in animals immunized with myelin basic protein in CFA clinical and pathological signs of EAE were lacking. The epitope recognition by anti-MOG Abs and T cells were assessed. Evidence is provided that the initiation of EAE is based on T and B cell activation by the encephalitogenic phMOG14–36 peptide in the context of monomorphic Caja-DRB*W1201 molecules.

α-Lipoic acid is effective in prevention and treatment of experimental autoimmune encephalomyelitis

Abstract α-Lipoic acid (α-LA) is a neuroprotective metabolic antioxidant that has been shown to cross the blood brain barrier. We tested whether α-LA is capable to prevent MOG35–55-induced experimental autoimmune encephalomyelitis (EAE), an established model of multiple sclerosis (MS). Daily oral administration of α-LA, starting at the time of immunization, significantly prevented EAE progression as compared to control mice. This was associated with a reduction of CNS infiltrating T cells and macrophages as well as decreased demyelination. We then tested α-LA in a therapeutic protocol aimed at suppressing EAE after its onset. Intraperitoneal (i.p.), but not oral, administration of α-LA significantly prevented disease progression when compared to vehicle-treated controls. Similarly, we observed significant reduction of demyelination and inflammatory infiltration. This clinical effect was not due to an impairment of MOG35–55 recognition by encephalitogenic T cells. In contrast, MOG-specific T cells showed a decreased production of IFNγ and IL-4, suggesting an immunosuppressive activity on both Th1 and Th2 cytokines. In addition, α-LA inhibited the proteolytic activity of MMP2 and MMP9 only at very high doses. Our data indicate that α-LA can effectively interfere with the autoimmune reaction associated with EAE through mechanisms other than its antioxidant activity and supports further studies on the use of α-LA as a potential therapy for MS.

Short-term accrual of gray matter pathology in patients with progressive multiple sclerosis: an in vivo study using diffusion tensor MRI

The mechanisms underlying the progressive course of multiple sclerosis (MS) are not fully understood yet. Since diffusion tensor (DT) MRI can provide quantitative estimates of both MRI-visible and MRI-occult brain damage related to MS, the present study investigated the value of DT MRI-derived measures for the assessment of the short-term accumulation of white and gray matter (GM) pathology in patients with primary progressive (PP) and secondary progressive (SP) MS. Fifty-four patients with PPMS and 22 with SPMS were studied at baseline and after a mean follow-up of 15 months. Dual-echo, T1-weighted, and DT MRI scans of the brain were acquired on both occasions. Total lesion volumes (TLV) and percentage brain volume changes (PBVC) were computed. Mean diffusivity (MD) and fractional anisotropy (FA) maps of the normal-appearing white (NAWM) and gray matter (NAGM) were produced, and histogram analysis was performed. In both patient groups, a significant increase of average lesion MD (P = 0.01) and of average NAGM MD (P = 0.007) was found at follow-up. No significant differences between PPMS and SPMS patient groups were found for the on-study changes of any MRI-derived measure. No significant correlations were found between the percentage changes of DT MRI-derived measures and those of TLV and PBVC. No significant changes of DT MRI-derived measures were observed in age-matched healthy controls over the same study period. Over a 1-year period of follow-up, DT MRI can detect tissue changes beyond the resolution of conventional MRI in the NAGM of patients with progressive MS. The accumulation of DT MRI-detectable gray matter damage does not seem to merely depend upon the concomitant increase of T2-visible lesion load and the reduction of brain volume. These observations suggest that progressive NAGM damage might yet be an additional factor leading to the accumulation of disability in progressive MS.

Differential regulation of the zinc finger genes Krox-20 and Krox-24 (Egr-1) suggests antagonistic roles in Schwann cells

Krox‐20 and Krox‐24 (Egr‐1) encode closely related zinc finger transcription factors, which interact with the same DNA target sequences. Krox‐20 is required for myelination in the peripheral nervous system. Using lacZ knock‐in mutant mouse lines as well as immunohistochemical analyses, we have studied the expression of Krox‐20 and Krox‐24 in the Schwann cell lineage during normal development and following nerve lesion in the mouse and in human neuropathies. During embryogenesis, the two genes are expressed in a successive and mutually exclusive manner, Krox‐24 being restricted to Schwann cell precursors and Krox‐20 to mature Schwann cells. At birth, Krox‐24 is reactivated and the two genes are coexpressed. In the adult, Krox‐20 is expressed in myelinating cells, while Krox‐24 is restricted to nonmyelinating cells. Following nerve lesion, Krox‐24 is strongly induced in Schwann cells, reinforcing the link between its expression and the nonmyelinating and/or proliferative state, whereas Krox‐20 is downregulated. These data are consistent with Krox‐20 and Krox‐24 playing antagonistic roles during the development of the Schwann cell lineage. In particular, their balance of expression might participate in the choice between myelinating and nonmyelinating pathways. J. Neurosci. Res. 50:702–712, 1997. © 1997 Wiley‐Liss, Inc.