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Biomedical subjects

Roberto Furlan

Publications and source records attributed to Roberto Furlan.

18 recordsLinked to original sources

Secondary progressive multiple sclerosis: current knowledge and future challenges.

The secondary progressive phase of multiple sclerosis (MS), which is characterised by a steady accrual of fixed disability after an initial relapsing remitting course, is not clearly understood. Although there is no consensus on the mechanisms underlying such a transition to the progressive phase, epidemiological and neuroimaging studies indicate that it is probably driven by the high prevalence of neurodegenerative compared with inflammatory pathological changes. This notion is lent support by the limited efficacy of available immunomodulating and immunosuppressive treatment strategies, which seems to be further decreased in the late stages of secondary progressive MS. No established clinical or paraclinical predictors of the transition from relapsing remitting to secondary progressive MS have been described. However, the use of quantitative MRI-derived measures is warranted to monitor natural history studies and therapeutic trials of secondary progressive MS with increased reliability. In view of the small effects of immunomodulating and immunosuppressive treatments in preventing the transition to secondary progression, the development of treatments promoting neuroaxonal repair remains an important goal in this disease.

Adjuvants, Immunologic↗

Neurosphere-derived multipotent precursors promote neuroprotection by an immunomodulatory mechanism.

In degenerative disorders of the central nervous system (CNS), transplantation of neural multipotent (stem) precursor cells (NPCs) is aimed at replacing damaged neural cells. Here we show that in CNS inflammation, NPCs are able to promote neuroprotection by maintaining undifferentiated features and exerting unexpected immune-like functions. In a mouse model of chronic CNS inflammation, systemically injected adult syngeneic NPCs use constitutively activated integrins and functional chemokine receptors to selectively enter the inflamed CNS. These undifferentiated cells survive repeated episodes of CNS inflammation by accumulating within perivascular areas where reactive astrocytes, inflamed endothelial cells and encephalitogenic T cells produce neurogenic and gliogenic regulators. In perivascular CNS areas, surviving adult NPCs induce apoptosis of blood-borne CNS-infiltrating encephalitogenic T cells, thus protecting against chronic neural tissue loss as well as disease-related disability. These results indicate that undifferentiated adult NPCs have relevant therapeutic potential in chronic inflammatory CNS disorders because they display immune-like functions that promote long-lasting neuroprotection.

Animals↗

Immunological patterns identifying disease course and evolution in multiple sclerosis patients.

Reliable, and easy to measure, immunological markers able to denote disease characteristics in multiple sclerosis (MS) patients are still lacking. We applied a multivariate statistical analysis on results obtained by measuring-by real-time RT-PCR-mRNA levels of 25 immunological relevant molecules in PBMCs from 198 MS patients. The combined measurement of mRNA levels of IL-1beta, TNF-alpha, TGF-beta, CCL20 and CCR3 was able to distinguish MS patients from healthy individuals. CXCR5, CCL5, and CCR3 combined mRNA levels identify primary progressive MS patients while TNF-alpha, IL-10, CXCL10 and CCR3 differentiate relapsing MS patients. Our results indicate that multi-parametric analysis of mRNA levels of immunological relevant molecules in PBMCs may represent a successful strategy for the identification of putative peripheral markers of disease state and disease activity in MS patients.

Adult↗

Alpha-lipoic acid is effective in prevention and treatment of experimental autoimmune encephalomyelitis.

Alpha-lipoic acid (alpha-LA) is a neuroprotective metabolic antioxidant that has been shown to cross the blood brain barrier. We tested whether alpha-LA is capable to prevent MOG35-55-induced experimental autoimmune encephalomyelitis (EAE), an established model of multiple sclerosis (MS). Daily oral administration of alpha-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 alpha-LA in a therapeutic protocol aimed at suppressing EAE after its onset. Intraperitoneal (i.p.), but not oral, administration of alpha-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 IFNgamma and IL-4, suggesting an immunosuppressive activity on both Th1 and Th2 cytokines. In addition, alpha-LA inhibited the proteolytic activity of MMP2 and MMP9 only at very high doses. Our data indicate that alpha-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 alpha-LA as a potential therapy for MS.

Analysis of Variance↗

A nitric oxide releasing derivative of flurbiprofen inhibits experimental autoimmune encephalomyelitis.

Nitric oxide (NO)-releasing non-steroidal anti-inflammatory drugs (NSAIDs) have been reported to have a safer profile and additional anti-inflammatory and immuno-modulatory properties compared to parent compounds. Preventive treatment of experimental autoimmune encephalomyelitis (EAE)-induced in C57BL/6 mice by immunization with myelin oligodendrocyte glycoprotein (MOG) peptide 35-55-with the NO-releasing derivative of flurbiprofen HCT1026 delayed disease onset and significantly decreased disease severity. HCT1026 treatment was associated to (i) decreased mRNA levels of pro-inflammatory cytokines, caspase-1, and iNOS in blood cells; (ii) decreased ability of encephalitogenic T cells to proliferate; (iii) reduced number of central nervous system (CNS)-infiltrating T cells; (iv) decreased axonal loss and demyelination; (v) increased CD4(+) CD69(-) CD25(+) regulatory T cells in the spleen.

Administration, Oral↗

Cell-based remyelinating therapies in multiple sclerosis: evidence from experimental studies.

PURPOSE OF REVIEW: Spontaneous remyelination occurs in the central nervous system of patients with multiple sclerosis. However, this process is not robust enough to promote a functional and stable recovery of the myelin architecture. The development of cell-based therapies, aimed at promoting multifocal remyelination, is therefore foreseen. RECENT FINDINGS: Several experimental cell-based strategies aimed at replacing damaged myelin-forming cells have been developed in the last few years. However, most of these therapeutic approaches - although consistently able to form new myelin sheaths at the transplantation site - are unfeasible owing to the mutifocality of the demyelinating process in multiple sclerosis patients and the inability to grow and produce large numbers of differentiated myelin-forming cells in vitro. Stem cell-based therapies that partially overcome these limitations have been proposed recently. SUMMARY: Stem cell-based remyelinating therapies can be considered a plausible alternative strategy in immune-mediated demyelinating disorders. However, before any potential applications in patients with multiple sclerosis can be envisaged, it is necessary to confront the following preliminary, and still unsolved, questions: (1) the ideal stem cell source for transplantation; (2) the most appropriate route of stem cell administration; and, last but not least, (3) the best approach for achieving an appropriate, functional and long-lasting integration of transplanted stem cells into the host tissue.

Animals↗

Detection of TNF and TNF receptor mRNA in cells and tissues.

We describe a semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) technique for the quantification of the messenger RNA of human and murine tumor necrosis factor alpha (TNFalpha) and related receptors. This protocol can be adapted for blood, peripheral blood lymphocytes, or other tissues. We propose a dot-blot technique which, if properly set up, is fast and quantitatively reliable. We describe two different detection protocols employing either radioactive or, alternatively for laboratories that cannot or do not want to use radioactivity, fluorescent-labeled probes. We also describe our calculations for relative quantification, based on the use of a positive control sample that becomes the reference value used to compare experimental samples. These protocols have as their aim to provide a flexible tool that can be employed in several different human and murine experimental settings by laboratories with different equipment.

Animals↗

TNFalpha in experimental diseases of the CNS.

Tumor necrosis factor alpha(TNFalpha) is a crucial mediator involved in the communications between immune and nervous systems in physiological conditions, and its relevance is amplified during disease. Considered originally detrimental and a target for therapeutic intervention, recently it has also gained attention for its protective role, especially in central nervous system (CNS) confined diseases. Thus, TNFalpha has become the key molecule illustrating the peculiar and still not completely understood pathways by which inflammatory and immune reactions occur in the brain. Several human pathologies that lack an efficient therapy and that carry enormous social costs rely on these mechanisms. Thus, further research is needed to improve our knowledge and to allow the identification of therapeutic targets or strategies for immune-mediated inflammatory disease of the CNS in which TNFalpha is primarily involved. We describe here how to induce experimental autoimmune encephalomyelitis, cerebral malaria, and brain ischemia in rodents, and some protocols to analyze them. The application of innovative research strategies or original therapeutic approaches to these experimental models may be rewarding in terms of advancement in a field that is crucial for the management of many human patients.

Animals↗

Gene therapy for autoimmune diseases.

Autoimmune diseases are threatening an increasing number of patients in developed countries, representing one of the major causes of disability and an enormous social cost. Current therapies mainly treat the symptoms of autoimmune diseases and are only partially able to interfere with disease evolution, and therefore decrease the degree of physical impairment. Thus, the development of new therapeutic strategies is imperative. This review focuses on gene therapy, as one possible alternative approach to the treatment of autoimmune disorders. The potential of gene therapy to specifically target tissues affected by autoimmune aggression, and its ability to interfere with the destructive pathogenic process while providing functional replacement and fostering reparative mechanisms will be emphasized. Gene therapy studies in experimental models of diabetes, rheumatoid arthritis and multiple sclerosis are reviewed.

Arthritis, Rheumatoid↗

Injection of adult neurospheres induces recovery in a chronic model of multiple sclerosis.

Widespread demyelination and axonal loss are the pathological hallmarks of multiple sclerosis. The multifocal nature of this chronic inflammatory disease of the central nervous system complicates cellular therapy and puts emphasis on both the donor cell origin and the route of cell transplantation. We established syngenic adult neural stem cell cultures and injected them into an animal model of multiple sclerosis--experimental autoimmune encephalomyelitis (EAE) in the mouse--either intravenously or intracerebroventricularly. In both cases, significant numbers of donor cells entered into demyelinating areas of the central nervous system and differentiated into mature brain cells. Within these areas, oligodendrocyte progenitors markedly increased, with many of them being of donor origin and actively remyelinating axons. Furthermore, a significant reduction of astrogliosis and a marked decrease in the extent of demyelination and axonal loss were observed in transplanted animals. The functional impairment caused by EAE was almost abolished in transplanted mice, both clinically and neurophysiologically. Thus, adult neural precursor cells promote multifocal remyelination and functional recovery after intravenous or intrathecal injection in a chronic model of multiple sclerosis.

Aging↗

Activation of invariant NKT cells by alphaGalCer administration protects mice from MOG35-55-induced EAE: critical roles for administration route and IFN-gamma.

Invariant NKT (inv. NKT) cells co-express an invariant alpha beta T cell receptor and the NK receptor NK1.1 and, upon CD1d-restricted recognition of the glycosphingolipid antigen alpha-galactosyl ceramide (alphaGalCer), secrete large amounts of regulatory cytokines. We investigated whether alphaGalCer-dependent activation of inv. NKT cells protects from experimental autoimmune encephalomyelitis (EAE), an immune-mediated disease of the central nervous system mimicking multiple sclerosis, induced in C57BL/6 mice by the myelin oligodendrocyte glycoprotein (MOG) encephalitogenic peptide aa 35-55. alphaGalCer was administered at the time of immunization s.c., mixed with complete Freund's adjuvant and MOG35-55 peptide, or administered i.p., diluted in PBS. EAE onset was delayed and disease severity was decreased only when alphaGalCer was s.c. administered. The protective effect of s.c. administration of alphaGalCer was associated with a markedly enhanced IFN-gamma production by liver-confined inv. NKT cells which, in turn, suppressed Th1-cytokine production and fostered secretion of IL-10 from MOG35-55-specific T cells. In vivo neutralization of IFN-gamma, but notIL-4, reversed the protective effect induced by s.c. administration of alphaGalCer, further confirming the critical regulatory role exerted by IFN-gamma-producing inv. NKT cells. Our results indicate that alphaGalCer, properly administered, may elicit an inv. NKT-cell-mediated suppressive effect on the effector function of encephalitogenic T cells; this effect is able to ameliorate autoimmunedemyelination.

Animals↗

Vaccination with amyloid-beta peptide induces autoimmune encephalomyelitis in C57/BL6 mice.

Recent experimental evidence shows that vaccination with amyloid-beta peptide (Abeta) of transgenic mouse models of Alzheimer's disease protects from the pathological accumulation of amyloid within the CNS. Phase I/II clinical trials of Abeta vaccination in mild to moderate Alzheimer's disease have been undertaken. Un expectedly, one of these trials has been suspended because 15 patients showed clinical signs consistent with CNS inflammation. Here, we show that C57BL/6 mice immunized with Abeta1-42 peptide develop an inflammatory disease of the CNS characterized by the presence both in the brain and spinal cord of perivenular inflammatory foci containing macrophages, T and B cells, and immunoglobulins. The experimental disease was observed only when pertussis toxin, an agent known to favour autoimmune processes, was co-administered. The immune-mediated CNS reaction was associated to Abeta-induced CD4(+) cells showing a Th1-type cytokine expression profile and to elevated levels of circulating anti-Abeta immunoglobulins. Our results indicate that vaccination with Abeta could determine, under certain circumstances, an aberrant autoimmune-type reaction to Abeta resulting in a perivenular inflammatory encephalomyelitis.

Alzheimer Disease↗

The therapeutic use of gene therapy in inflammatory demyelinating diseases of the central nervous system.

PURPOSE OF REVIEW: Gene therapy protocols aimed to deliver therapeutic molecules into the central nervous system may represent an alternative therapeutic strategy in patients affected by inflammatory demyelinating diseases of the central nervous system where systemic therapies have shown limited therapeutic efficacy possibly owing to the blood-brain barrier, a major obstacle for the entry of therapeutic molecules into the central nervous system. RECENT FINDINGS: Among inflammatory demyelinating diseases of the central nervous system, gene therapy approaches have been so far developed almost exclusively for multiple sclerosis. However, the chronic/relapsing nature of the disease, the restriction to the central nervous system of the pathological process as well as the necessity to inhibit the ongoing inflammatory process but also to foster endogenous remyelinating pathways, have posed several questions which still need to be properly addressed for the development of a successful gene therapy strategy in multiple sclerosis patients. SUMMARY: The gene therapy approaches for multiple sclerosis have been so far developed and tested only in rodents and monkeys with experimental autoimmune encephalomyelitis, the animal model of multiple sclerosis. The results of these studies clearly indicate that the delivery of therapeutic genes within the central nervous system is superior to the peripheral delivery. In particular, the intracerebral delivery of genes coding for anti-inflammatory and/or neurotrophic molecules, using gene vectors derived from non-replicative viruses, showed to inhibit not only the detrimental function of blood-borne mononuclear effector cells but also to foster proliferation and differentiation of surviving oligodendrocytes within demyelinated areas. Here, we summarize the most recent findings of this novel area of research.

Animals↗

Gene therapy-mediated modulation of immune processes in the central nervous system.

Selective interference with immune processes in the central nervous system (CNS) is a very difficult task because of the limitations associated with the delivery of immuno modulatory molecules across the blood brain barrier. Systemic administration of immune-mediators, either by conventional routes or by intramuscularly or intravenous gene therapy, is hampered by severe side effects and alters immune-system functions also in peripheral organs. To overcome these problems, different gene therapy strategies have been developed to deliver immuno modulatory molecules directly within the central nervous system. The use of engineered CNS antigen-specific circulating cells as selective delivery vehicles, the direct injection of gene vectors into the brain parenchyma, or also the ependymal route, have been proposed as possible alternative gene therapy protocols to selectively interfere with immuno-pathological processes in the CNS. We will review the use of these CNS-targeted gene therapy protocols for the treatment of experimental autoimmune encephalomyelitis (EAE), the prototypical experimental immune-mediated disease of the CNS, and therefore discuss the relevance of these results for the therapy of multiple sclerosis (MS) the most common, immune-mediated, demyelinating disease of the CNS in humans.

Adjuvants, Immunologic↗

Caspase-1 levels in biological fluids from patients with multiple sclerosis and from patients with other neurological and non-neurological diseases.

In multiple sclerosis (MS), pathological white matter damage in the central nervous system is sustained by immune-inflammatory response. Caspase-1 plays a pivotal role in immune-mediated inflammation, as it regulates the cellular export of IL-1beta and IL-18. We carried out a preliminary in vitro study of the kinetics of extracellular caspase-1 release. We then measured caspase-1 levels in paired serum and cerebrospinal fluid (CSF) samples of 75 MS patients, 15 healthy subjects, and patients with other neurological diseases. Paired synovial fluid and serum samples of patients with juvenile idiopathic arthritis, and paired sputum and serum samples of asthma patients were also studied. Mean serum caspase-1 concentrations did not differ between groups. Caspase-1 was detected in the CSF of patients with acute, but not stable, MS [7.5 +/- (SEM) 0.9 pg/ml; test's sensitivity, 56% and specificity, 100%]. Its levels correlated with pleocytosis. The highest mean caspase-1 levels were found in the arthritic synovial fluids (945.5 +/- 126.6 pg/ml, which correlated with erythrocyte sedimentation rate), and in the sputum samples (370.1 +/- 71.0 pg/ml, which correlated with the number of macrophages in the sputum). On condition that caspase-1 is determined in the fluids pertaining to the disease-specific inflammatory sites, its level is a reliable marker of ongoing immune-inflammatory response. The enzyme measurement in CSF can also help define state-trait in MS.

Arthritis, Juvenile↗